Sample records for enterococci surface protein
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Water-quality data for the Russian River Basin, Mendocino and Sonoma Counties, California, 2005-2010
Anders, Robert; Davidek, Karl; Stoeckel, Donald M.
2011-01-01
Field measurements included discharge, barometric pressure, dissolved oxygen, pH, specific conductance, temperature, and turbidity. All samples were analyzed for nutrients, major ions, trace metals, total and dissolved organic carbon, organic wastewater compounds, standard bacterial indicators, and the stable isotopes of hydrogen and oxygen. Standard bacterial indicators included total coliform, Escherichia coli, enterococci, and Clostridium perfringens for the period 2005 through 2007, and total and fecal coliform, and enterococci for 2010. In addition, enrichment of enterococci was performed on all surface-water samples collected during summer 2006, for detection of the human-associated enterococcal surface protein in Enterococcus faecium to assess the presence of sewage effluent in the Russian River. Other analyses included organic wastewater compounds of bed sediment samples collected from four Russian River sites during 2005; carbon-13 isotopic values of the dissolved inorganic carbon for surface-water and groundwater samples collected during 2006; human-use pharmaceuticals on Russian River samples collected during 2007 and 2010; and the radiogenic isotopes tritium and carbon-14 for groundwater samples collected during 2008.
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KuKanich, Kate S; Ghosh, Anuradha; Skarbek, Jennifer V; Lothamer, Kale M; Zurek, Ludek
2012-02-15
To determine the prevalence of bacterial contamination on 4 surfaces of 4 types of standard equipment in small animal veterinary hospitals. Surveillance study. 10 small animal veterinary hospitals. Each hospital was visited 3 times at 4-month intervals; at each visit, a cage door, stethoscope, rectal thermometer, and mouth gag were swabbed. Swab samples were each plated onto media for culture of enterococci and organisms in the family Enterobacteriaceae. Enterococci were identified via a species-specific PCR assay and sodA gene sequencing; species of Enterobacteriaceae were identified with a biochemical test kit. Antimicrobial susceptibility was assessed via the disk diffusion method. Enterococci were screened for virulence traits and genotyped to assess clonality. Among the 10 hospitals, enterococci were isolated from cage doors in 7, from stethoscopes in 7, from thermometers in 6, and from mouth gags in 1; contamination with species of Enterobacteriaceae was rare. Enterococci were mainly represented by Enterococcus faecium (35.4%), Enterococcus faecalis (33.2%), and Enterococcus hirae (28.3%). Antimicrobial resistance was common in E. faecium, whereas virulence traits were present in 99% of E. faecalis isolates but not in E. faecium isolates. Clonal multidrug-resistant E. faecium was isolated from several surfaces at 1 hospital over multiple visits, whereas sporadic nonclonal contamination was detected in other hospitals. Contamination of surfaces in small animal veterinary hospitals with multidrug-resistant enterococci is a potential concern for pets and humans contacting these surfaces. Implementing precautions to minimize enterococcal contamination on these surfaces is recommended.
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Ahmed, W; Stewart, J; Gardner, T; Powell, D; Brooks, P; Sullivan, D; Tindale, N
2007-08-01
Library-dependent (LD) (biochemical fingerprinting of Escherichia coli and enterococci) and library-independent (LI) (PCR detection of human-specific biomarkers) methods were used to detect human faecal pollution in three non-sewered catchments. In all, 550 E. coli isolates and 700 enterococci isolates were biochemically fingerprinted from 18 water samples and compared with metabolic fingerprint libraries of 4508 E. coli and 4833 enterococci isolates. E. coli fingerprints identified human unique biochemical phenotypes (BPTs) in nine out of 18 water samples; similarly, enterococci fingerprints identified human faecal pollution in 10 water samples. Seven samples were tested by PCR for the detection of biomarkers. Human-specific HF134 Bacteroides and enterococci surface protein (esp) biomarkers were detected in five samples. Four samples were also positive for HF183 Bacteroides biomarker. The combination of biomarkers detected human faecal pollution in six out of seven water samples. Of the seven samples analysed for both the indicators/markers, at least one indicator/marker was detected in every sample. Four of the seven PCR-positive samples were also positive for one of the human-specific E. coli or enterococci BPTs. The results indicated human faecal pollution in the studied sub-catchments after storm events. LD and LI methods used in this study complimented each other and provided additional information regarding the polluting sources when one method failed to detect human faecal pollution. Therefore, it is recommended that a combination of methods should be used to identify the source(s) of faecal pollution where possible.
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Ben Said, Leila; Klibi, Naouel; Lozano, Carmen; Dziri, Raoudha; Ben Slama, Karim; Boudabous, Abdellatif; Torres, Carmen
2015-10-15
One hundred-fourteen samples of wastewater (n=64) and surface-water (n=50) were inoculated in Slanetz-Bartley agar plates supplemented or not with gentamicin (SB-Gen and SB plates, respectively) for enterococci recovery. Enterococci were obtained from 75% of tested samples in SB media (72% in wastewater; 78% in surface-water), and 85 enterococcal isolates (one/positive-sample) were obtained. Enterococcus faecium was the most prevalent species (63.5%), followed by Enterococcus faecalis (20%), Enterococcus hirae (9.4%), Enterococcus casseliflavus (4.7%), and Enterococcus gallinarum/Enterococcus durans (2.4%). Antibiotic resistance detected among these enterococci was as follows [percentage/detected gene (number isolates)]: kanamycin [29%/aph(3')-IIIa (n=22)], streptomycin [8%/ant(6)-Ia (n=4)], erythromycin [44%/erm(B) (n=34)], tetracycline [18%/tet(M) (n=6)/tet(M)-tet(L) (n=9)], chloramphenicol [2%/cat(A) (n=1)], ciprofloxacin [7%] and trimethoprim-sulfamethoxazole [94%]. High-level-gentamicin resistant (HLR-G) enterococci were recovered from 15 samples in SB-Gen or SB plates [12/64 samples of wastewater (19%) and 3/50 samples of surface-water (6%)]; HLR-G isolates were identified as E. faecium (n=7), E. faecalis (n=6), and E. casseliflavus (n=2). These HLR-G enterococci carried the aac(6')-Ie-aph(2")-Ia and erm(B) genes, in addition to aph(3')-IIIa (n=10), ant(6)-Ia (n=9), tet(M) (n=13), tet(L) (n=8) and cat(A) genes (n=2). Three HLR-G enterococci carried the esp virulence gene. Sequence-types detected among HLR-G enterococci were as follows: E. faecalis (ST480, ST314, ST202, ST55, and the new ones ST531 and ST532) and E. faecium (ST327, ST12, ST296, and the new ones ST985 and ST986). Thirty-two different PFGE patterns were detected among 36 high-level-aminoglycoside-resistant enterococci recovered in water samples. Diverse genetic lineages of HLR-G enterococci were detected in wastewater and surface-water in Tunisia. Water can represent an important source for the dissemination of these antibiotic resistant microorganisms to other environments. Copyright © 2015 Elsevier B.V. All rights reserved.
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Byappanahalli, M.N.; Przybyla-Kelly, K.; Shively, D.A.; Whitman, R.L.
2008-01-01
The enterococcal surface protein (esp) gene found in Enterococcus faecalis and E. faecium has recently been explored as a marker of sewage pollution in recreational waters but its occurrence and distribution in environmental enterococci has not been well-documented. If the esp gene is found in environmental samples, there are potential implications for microbial source tracking applications. In the current study, a total of 452 samples (lake water, 100; stream water, 129; nearshore sand, 96; and backshore sand, 71; Cladophora sp. (Chlorophyta), 41; and periphyton (mostly Bacillariophyceae), 15) collected from the coastal watersheds of southern Lake Michigan were selectively cultured for enterococci and then analyzed for the esp gene by PCR, targeting E. faecalis/ E. faecium (espfs/fm) and E. faecium (espfm). Overall relative frequencies for espfs/fm and espfm were 27.4 and 5.1%. Respective percent frequency for the espfs/fm and espfm was 36 and 14% in lake water; 38.8 and 2.3% in stream water; 24 and 6.3% in nearshore sand; 0% in backshore sand; 24.4 and 0% in Cladophora sp.; and 33.3 and 0% in periphyton. The overall occurrence of both espfs/fm and espfm was significantly related (χ2 = 49, P espfs/fm increased in lake and stream water and nearshore sand. Further, E. coli and enterococci cell densities were significant predictors for espfs/fm occurrence in post-rain lake water, but espfm was not. F+ coliphage densities were not significant predictors for espfm or espfs/fm gene incidence. In summary, the differential occurrence of the esp gene in the environment suggests that it is not limited to human fecal sources and thus may weaken its use as a reliable tool in discriminating contaminant sources (i.e., human vs nonhuman).
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Styriak, I; Lauková, A; Fallgren, C; Wadström, T
1999-12-01
Thirty-three enterococcal strains and 10 Streptococcus bovis strains were investigated for their protein-binding cell surface components. Seven extracellular matrix (ECM) proteins were immobilized on Difco latex beads to detect these components on the surface of all enterococcal strains and eight non-autoaggregating S. bovis strains by a particle agglutination assay (PAA). Twenty-three selected strains were also examined in microtiter plate assays. According to the absorbance readings (A(570nm)), 11 strains were classified as nonadherent (A(570nm) < 0.1), 10 strains as weakly adherent (0.1 < A(570nm) > 0.3), and 2 strains as strongly adherent (A(570nm) > 0.3) in these assays. A direct correlation was found between the values obtained in PAA and A(570nm) readings of microtiter plate assays. Binding of (125)I-labeled bovine lactoferrin to enterococci and streptococci was in the range of 6%-30% and of (125)I-labeled human vitronectin in the range of 9%-33% to streptococci. The binding of(125)I-labeled ECM proteins to selected strains was much more effectively inhibited by sulfated carbohydrates than by non-sulfated hyaluronic acid, indicating the importance of the sulfate groups of these inhibitors. An inhibition effect of heparin on bLf binding to four selected strains was higher in comparison with fucoidan in the microtiter plates. Thirty-five out of 44 strains had agglutinated rabbit erythrocytes. However, these strains showed no ability to agglutinate bovine or sheep erythrocytes.
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Larsen, Bryan; Essmann, Michael K; Geletta, Simon; Duff, Barbara
2012-01-01
The object of this study was to quantify vancomycin-resistant enterococci in surface water from Central Iowa obtained from April 2007 to August 2007. Water from established sampling sites in four watersheds was plated on bile-esculin agar. Presumptively identified enterococci were categorized as "above the level of concern" if the sample contained ≥ 107 CFU per 100 ml. Confirmation of isolates as enterococci was based on growth at elevated temperature in high salt and on Enterococcus agar. Isolates that grew on 6 μg/ml vancomycin agar were deemed resistant. PCR analysis of resistant strains characterized vancomycin resistance genes. 77.2% of surface water samples from Central Iowa contained enterococci. Among enterococcal isolates, 10.4% grew on media containing 6 μg/ml vancomycin. PCR analysis of resistance genes showed a preponderance of VanC2/C3 in the area studied and VanB was not detected. Vancomycin-resistant Enterococcus is present in Central Iowa surface waters but resistance rarely involved VanA genotypes. Nevertheless, the potential for community-acquired infections remains a risk.
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Multi-scale landscape factors influencing stream water quality in the state of Oregon.
Nash, Maliha S; Heggem, Daniel T; Ebert, Donald; Wade, Timothy G; Hall, Robert K
2009-09-01
Enterococci bacteria are used to indicate the presence of human and/or animal fecal materials in surface water. In addition to human influences on the quality of surface water, a cattle grazing is a widespread and persistent ecological stressor in the Western United States. Cattle may affect surface water quality directly by depositing nutrients and bacteria, and indirectly by damaging stream banks or removing vegetation cover, which may lead to increased sediment loads. This study used the State of Oregon surface water data to determine the likelihood of animal pathogen presence using enterococci and analyzed the spatial distribution and relationship of biotic (enterococci) and abiotic (nitrogen and phosphorous) surface water constituents to landscape metrics and others (e.g. human use, percent riparian cover, natural covers, grazing, etc.). We used a grazing potential index (GPI) based on proximity to water, land ownership and forage availability. Mean and variability of GPI, forage availability, stream density and length, and landscape metrics were related to enterococci and many forms of nitrogen and phosphorous in standard and logistic regression models. The GPI did not have a significant role in the models, but forage related variables had significant contribution. Urban land use within stream reach was the main driving factor when exceeding the threshold (> or =35 cfu/100 ml), agriculture was the driving force in elevating enterococci in sites where enterococci concentration was <35 cfu/100 ml. Landscape metrics related to amount of agriculture, wetlands and urban all contributed to increasing nutrients in surface water but at different scales. The probability of having sites with concentrations of enterococci above the threshold was much lower in areas of natural land cover and much higher in areas with higher urban land use within 60 m of stream. A 1% increase in natural land cover was associated with a 12% decrease in the predicted odds of having a site exceeding the threshold. Opposite to natural land cover, a one unit change in each of manmade barren and urban land use led to an increase of the likelihood of exceeding the threshold by 73%, and 11%, respectively. Change in urban land use had a higher influence on the likelihood of a site exceeding the threshold than that of natural land cover.
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Glew, Richard H.; Moellering, Robert C.
1979-01-01
To assess the effect of protein binding by human serum on the synergistic interaction of penicillins with gentamicin, time-kill curves were determined for four penicillins alone and in combination with gentamicin against 10 blood isolates of enterococci. Killing curves demonstrated synergism with penicillin G plus gentamicin against all 10 strains in either broth or 50% human serum. In broth the combinations of nafcillin plus gentamicin and oxacillin plus gentamicin were synergistic against 10 of 10 strains and 4 of 10 strains, respectively. However, in serum, nafcillin plus gentamicin was synergistically bactericidal against only two strains and oxacillin plus gentamicin against none. Methicillin plus gentamicin was synergistic against none of the enterococci in either medium. Thus, the semisynthetic, penicillinase-resistant penicillins are unlikely to be effective in the therapy of patients with enterococcal endocarditis. PMID:426508
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Osman, Kamelia M; Ali, Mohamed N; Radwan, Ismail; ElHofy, Fatma; Abed, Ahmed H; Orabi, Ahmed; Fawzy, Nehal M
2016-01-01
Although normally regarded harmless commensals, enterococci may cause a range of different infections in humans, including urinary tract infections, sepsis, and endocarditis. The acquisition of vancomycin resistance by enterococci (VRE) has seriously affected the treatment and infection control of these organisms. VRE are frequently resistant to all antibiotics that are effective treatment for vancomycin-susceptible enterococci, which leaves clinicians treating VRE infections with limited therapeutic options. With VRE emerging as a global threat to public health, we aimed to isolate, identify enterococci species from tilapia and their resistance to van-mediated glycopeptide (vanA and vanC) as well as the presence of enterococcal surface protein (esp) using conventional and molecular methods. The cultural, biochemical (Vitek 2 system) and polymerase chain reaction results revealed eight Enterococcus isolates from the 80 fish samples (10%) to be further identified as E. faecalis (6/8, 75%) and E gallinarum (2/8, 25%). Intraperitoneal injection of healthy Nile tilapia with the eight Enterococcus isolates caused significant morbidity (70%) within 3 days and 100% mortality at 6 days post-injection with general signs of septicemia. All of the eight Enterococcus isolates were found to be resistant to tetracycline. The 6/6 E. faecalis isolates were susceptible for penicillin, nitrofurantoin, gentamicin, and streptomycin. On the other hand 5/6 were susceptible for ampicillin, vancomycin, chloramphenicol, and ciprofloxacin. The two isolates of E. gallinarum were sensitive to rifampicin and ciprofloxacin and resistant to vancomycin, chloramphenicol, and erythromycin. Molecular characterization proved that they all presented the prototypic vanC element. On the whole, one of the two vancomycin resistance gene was present in 3/8 of the enterococci isolates, while the esp virulence gene was present in 1/8 of the enterococci isolates. The results in this study emphasize the potential role that aquatic environments are correlated to proximity to anthropogenic activities in determining the antimicrobial resistance patterns of Enterococcus spp. recovered from fish in the river Nile in Giza, Elmounib, Egypt as a continuation of our larger study on the reservoirs of antibiotic resistance in the environment.
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Collins, Susan M.; Hacek, Donna M.; Degen, Lisa A.; Wright, Marc O.; Noskin, Gary A.; Peterson, Lance R.
2001-01-01
We surveyed environmental surfaces in our clinical microbiology laboratory to determine the prevalence of vancomycin-resistant enterococci (VRE) and multidrug-resistant Enterobacteriaceae (MDRE) during a routine working day. From a total of 193 surfaces, VRE were present on 20 (10%) and MDRE were present on 4 (2%) of the surfaces tested. In a subsequent survey after routine cleaning, all of the 24 prior positive surfaces were found to be negative. Thus, those in the laboratory should recognize that many surfaces may be contaminated by resistant organisms during routine processing of patient specimens. PMID:11574615
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Laureano-Rosario, Abdiel E; Symonds, Erin M; Rueda-Roa, Digna; Otis, Daniel; Muller-Karger, Frank E
2017-12-19
Enterococci concentration variability at Escambron Beach, San Juan, Puerto Rico, was examined in the context of environmental conditions observed during 2005-2015. Satellite-derived sea surface temperature (SST), turbidity, direct normal irradiance, and dew point were combined with local precipitation, winds, and mean sea level (MSL) observations in a stepwise multiple regression analyses (Akaike Information Criteria model selection). Precipitation, MSL, irradiance, SST, and turbidity explained 20% of the variation in observed enterococci concentrations based upon these analyses. Changes in these parameters preceded increases in enterococci concentrations by 24 h up to 11 days, particularly during positive anomalies of turbidity, SST, and 480-960 mm of accumulated (4 days) precipitation, which relates to bacterial ecology. Weaker, yet still significant, increases in enterococci concentrations were also observed during positive dew point anomalies. Enterococci concentrations decreased with elevated irradiance and MSL anomalies. Unsafe enterococci concentrations per US EPA recreational water quality guidelines occurred when 4-day cumulative precipitation ranged 481-960 mm; irradiance < 667 W·m -2 ; daily average turbidity anomaly >0.005 sr -1 ; SST anomaly >0.8 °C; and 3-day average MSL anomaly <-18.8 cm. This case study shows that satellite-derived environmental data can be used to inform future water quality studies and protect human health.
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Macovei, Lilia; Zurek, Ludek
2006-01-01
In this project, enterococci from the digestive tracts of 260 houseflies (Musca domestica L.) collected from five restaurants were characterized. Houseflies frequently (97% of the flies were positive) carried enterococci (mean, 3.1 × 103 CFU/fly). Using multiplex PCR, 205 of 355 randomly selected enterococcal isolates were identified and characterized. The majority of these isolates were Enterococcus faecalis (88.2%); in addition, 6.8% were E. faecium, and 4.9% were E. casseliflavus. E. faecalis isolates were phenotypically resistant to tetracycline (66.3%), erythromycin (23.8%), streptomycin (11.6%), ciprofloxacin (9.9%), and kanamycin (8.3%). Tetracycline resistance in E. faecalis was encoded by tet(M) (65.8%), tet(O) (1.7%), and tet(W) (0.8%). The majority (78.3%) of the erythromycin-resistant E. faecalis isolates carried erm(B). The conjugative transposon Tn916 and members of the Tn916/Tn1545 family were detected in 30.2% and 34.6% of the identified isolates, respectively. E. faecalis carried virulence genes, including a gelatinase gene (gelE; 70.7%), an aggregation substance gene (asa1; 33.2%), an enterococcus surface protein gene (esp; 8.8%), and a cytolysin gene (cylA; 8.8%). Phenotypic assays showed that 91.4% of the isolates with the gelE gene were gelatinolytic and that 46.7% of the isolates with the asa1 gene aggregated. All isolates with the cylA gene were hemolytic on human blood. This study showed that houseflies in food-handling and -serving facilities carry antibiotic-resistant and potentially virulent enterococci that have the capacity for horizontal transfer of antibiotic resistance genes to other bacteria. PMID:16751512
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Macovei, Lilia; Zurek, Ludek
2006-06-01
In this project, enterococci from the digestive tracts of 260 houseflies (Musca domestica L.) collected from five restaurants were characterized. Houseflies frequently (97% of the flies were positive) carried enterococci (mean, 3.1 x 10(3) CFU/fly). Using multiplex PCR, 205 of 355 randomly selected enterococcal isolates were identified and characterized. The majority of these isolates were Enterococcus faecalis (88.2%); in addition, 6.8% were E. faecium, and 4.9% were E. casseliflavus. E. faecalis isolates were phenotypically resistant to tetracycline (66.3%), erythromycin (23.8%), streptomycin (11.6%), ciprofloxacin (9.9%), and kanamycin (8.3%). Tetracycline resistance in E. faecalis was encoded by tet(M) (65.8%), tet(O) (1.7%), and tet(W) (0.8%). The majority (78.3%) of the erythromycin-resistant E. faecalis isolates carried erm(B). The conjugative transposon Tn916 and members of the Tn916/Tn1545 family were detected in 30.2% and 34.6% of the identified isolates, respectively. E. faecalis carried virulence genes, including a gelatinase gene (gelE; 70.7%), an aggregation substance gene (asa1; 33.2%), an enterococcus surface protein gene (esp; 8.8%), and a cytolysin gene (cylA; 8.8%). Phenotypic assays showed that 91.4% of the isolates with the gelE gene were gelatinolytic and that 46.7% of the isolates with the asa1 gene aggregated. All isolates with the cylA gene were hemolytic on human blood. This study showed that houseflies in food-handling and -serving facilities carry antibiotic-resistant and potentially virulent enterococci that have the capacity for horizontal transfer of antibiotic resistance genes to other bacteria.
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Liu, L.; Phanikumar, M.S.; Molloy, S.L.; Whitman, R.L.; Shively, D.A.; Nevers, M.B.; Schwab, D.J.; Rose, J.B.
2006-01-01
To investigate the transport and fate of fecal pollution at Great Lakes beaches and the health risks associated with swimming, the near-shore waters of Lake Michigan and two tributaries discharging into it were examined for bacterial indicators of human fecal pollution. The enterococcus human fecal pollution marker, which targets a putative virulence factorthe enterococcal surface protein (esp) in Enterococcus faecium, was detected in 2/28 samples (7%) in the tributaries draining into Lake Michigan and in 6/30 samples (20%) in Lake Michigan beaches. This was indicative of human fecal pollution being transported in the tributaries and occurrence at Lake Michigan beaches. To understand the relative importance of different processes influencing pollution transport and inactivation, a finite-element model of surf-zone hydrodynamics (coupled with models for temperature, E. coli and enterococci) was used. Enterococci appear to survive longer than E. coli, which was described using an overall first-order inactivation coefficient in the range 0.5−2.0 per day. Our analysis suggests that the majority of fecal indicator bacteria variation can be explained based on loadings from the tributaries. Sunlight is a major contributor to inactivation in the surf-zone and the formulation based on sunlight, temperature and sedimentation is preferred over the first-order inactivation formulation.
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Rueda-Roa, Digna; Otis, Daniel; Muller-Karger, Frank E.
2017-01-01
Enterococci concentration variability at Escambron Beach, San Juan, Puerto Rico, was examined in the context of environmental conditions observed during 2005–2015. Satellite-derived sea surface temperature (SST), turbidity, direct normal irradiance, and dew point were combined with local precipitation, winds, and mean sea level (MSL) observations in a stepwise multiple regression analyses (Akaike Information Criteria model selection). Precipitation, MSL, irradiance, SST, and turbidity explained 20% of the variation in observed enterococci concentrations based upon these analyses. Changes in these parameters preceded increases in enterococci concentrations by 24 h up to 11 days, particularly during positive anomalies of turbidity, SST, and 480–960 mm of accumulated (4 days) precipitation, which relates to bacterial ecology. Weaker, yet still significant, increases in enterococci concentrations were also observed during positive dew point anomalies. Enterococci concentrations decreased with elevated irradiance and MSL anomalies. Unsafe enterococci concentrations per US EPA recreational water quality guidelines occurred when 4-day cumulative precipitation ranged 481–960 mm; irradiance < 667 W·m−2; daily average turbidity anomaly >0.005 sr−1; SST anomaly >0.8 °C; and 3-day average MSL anomaly <−18.8 cm. This case study shows that satellite-derived environmental data can be used to inform future water quality studies and protect human health. PMID:29257092
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Comparative evaluation of two methods of enumerating enterococci in foods: collaborative study.
Peterz, M; Steneryd, A C
1993-05-01
Two methods of enumerating enterococci in foods were compared in a collaborative study. Thirteen laboratories tested four blind duplicate samples containing different levels of enterococci and two negative control samples. Freeze-dried mixtures of bacteria were used as simulated food samples. The freeze-dried samples were reconstituted and either spread directly on the surface of Slanetz and Bartley medium (SB) and incubated at 44 degrees C for 48 h or preincubated in tryptone soya agar at 37 degrees C for 2 h before being overlaid by SB and incubated at 37 degrees C for a further 46 h. The numbers CFU of enterococci recovered by the two methods were not significantly different except for one sample where the 37 degrees C method gave a somewhat higher recovery. The 44 degrees C method was less time-consuming and less laborious.
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Lüddeke, Frauke; Heß, Stefanie; Gallert, Claudia; Winter, Josef; Güde, Hans; Löffler, Herbert
2015-02-01
Elimination of bacteria by ozonation in combination with charcoal or slow sand filtration for advanced sewage treatment to improve the quality of treated sewage and to reduce the potential risk for human health of receiving surface waters was investigated in pilot scale at the sewage treatment plant Eriskirch, Baden-Wuerttemberg/Germany. To determine the elimination of sewage bacteria, inflowing and leaving wastewater of different treatment processes was analysed in a culture-based approach for its content of Escherichia coli, enterococci and staphylococci and their resistance against selected antibiotics over a period of 17 month. For enterococci, single species and their antibiotic resistances were identified. In comparison to the established flocculation filtration at Eriskirch, ozonation plus charcoal or sand filtration (pilot-scale) reduced the concentrations of total and antibiotic resistant E. coli, enterococci and staphylococci. However, antibiotic resistant E. coli and staphylococci apparently survived ozone treatment better than antibiotic sensitive strains. Neither vancomycin resistant enterococci nor methicillin resistant Staphylococcus aureus (MRSA) were detected. The decreased percentage of antibiotic resistant enterococci after ozonation may be explained by a different ozone sensitivity of species: Enterococcus faecium and Enterococcus faecalis, which determined the resistance-level, seemed to be more sensitive for ozone than other Enterococcus-species. Overall, ozonation followed by charcoal or sand filtration led to 0.8-1.1 log-units less total and antibiotic resistant E. coli, enterococci and staphylococci, as compared to the respective concentrations in treated sewage by only flocculation filtration. Thus, advanced wastewater treatment by ozonation plus charcoal or sand filtration after common sewage treatment is an effective tool for further elimination of microorganisms from sewage before discharge in surface waters. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Evaluation of (GTG)5-PCR for identification of Enterococcus spp.
Svec, Pavel; Vancanneyt, Marc; Seman, Milan; Snauwaert, Cindy; Lefebvre, Karen; Sedlácek, Ivo; Swings, Jean
2005-06-01
A set of reference strains and a group of previously unidentified enterococci were analysed by rep-PCR with the (GTG)(5) primer to evaluate the discriminatory power and suitability of this method for typing and identification of enterococcal species. A total of 49 strains representing all validly described species were obtained from bacterial collections. For more extensive evaluation of this identification approach 112 well-defined and identified enterococci isolated from bryndza cheese were tested. The (GTG)(5)-PCR fingerprinting assigned all strains into well-differentiated clusters representing individual species. Subsequently, a group including 44 unidentified enterococci isolated from surface waters was analysed to evaluate this method for identification of unknown isolates. Obtained band patterns allowed us to identify all the strains clearly to the species level. This study proved that rep-PCR with (GTG)(5) primer is a reliable and fast method for species identification of enterococci.
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Biswas, Priyanka Paul; Dey, Sangeeta; Sen, Aninda; Adhikari, Luna
2016-01-01
Background: The aim of this study was to find out the correlation between presence of virulence (gelatinase [gel E], enterococcal surface protein [esp], cytolysin A [cyl A], hyaluronidase [hyl], and aggregation substance [asa1]) and vancomycin-resistant genes (van A and van B) in enterococci, with their phenotypic expression. Materials and Methods: A total of 500 isolates (250 each clinical and fecal) were processed. Enterococci were isolated from various clinical samples and from fecal specimens of colonized patients. Various virulence determinants namely asa1, esp, hyl, gel E, and cyl were detected by phenotypic methods. Minimum inhibitory concentration (MIC) of vancomycin was determined by agar dilution method. Multiplex polymerase chain reaction (PCR) was used to detect the presence of virulence and van genes. Results: Out of all the samples processed, 12.0% (60/500) isolates carried van A or van B genes as confirmed by MIC test and PCR methods. Genes responsible for virulence were detected by multiplex PCR and at least one of the five was detected in all the clinical vancomycin-resistant enterococci (VRE) and vancomycin-sensitive enterococci (VSE). gel E, esp, and hyl genes were found to be significantly higher in clinical VRE. Of the fecal isolates, presence of gel E, esp, and asa1 was significantly higher in VRE as compared to VSE. The presence of hyl gene in the clinical VRE was found to be statistically significant (P = 0.043) as against the fecal VRE. Correlation between the presence of virulence genes and their expression as detected by phenotypic tests showed that while biofilm production was seen in 61.1% (22/36) of clinical VRE, the corresponding genes, i.e., asa1 and esp were detected in 30.5% (11/36) and 27.8% (10/36) of strains only. Conclusion: Enterococcus faecium isolates were found to carry esp gene, a phenomenon that has been described previously only for Enterococcus faecalis, but we were unable to correlate the presence of esp with their capacity to form biofilms. PMID:27013840
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Guzmán Prieto, Ana M.; Urbanus, Rolf T.; Zhang, Xinglin; Bierschenk, Damien; Koekman, C. Arnold; van Luit-Asbroek, Miranda; Ouwerkerk, Janneke P.; Pape, Marieke; Paganelli, Fernanda L.; Wobser, Dominique; Huebner, Johannes; Hendrickx, Antoni P. A.; Bonten, Marc J. M.; Willems, Rob J. L.; van Schaik, Willem
2015-01-01
Enterococcus faecium is a commensal of the mammalian gastrointestinal tract, but is also found in non-enteric environments where it can grow between 10 °C and 45 °C. E. faecium has recently emerged as a multi-drug resistant nosocomial pathogen. We hypothesized that genes involved in the colonization and infection of mammals exhibit temperature-regulated expression control and we therefore performed a transcriptome analysis of the clinical isolate E. faecium E1162, during mid-exponential growth at 25 °C and 37 °C. One of the genes that exhibited differential expression between 25 °C and 37 °C, was predicted to encode a peptidoglycan-anchored surface protein. The N-terminal domain of this protein is unique to E. faecium and closely related enterococci, while the C-terminal domain is homologous to the Streptococcus agalactiae surface protein BibA. This region of the protein contains proline-rich repeats, leading us to name the protein PrpA for proline-rich protein A. We found that PrpA is a surface-exposed protein which is most abundant during exponential growth at 37 °C in E. faecium E1162. The heterologously expressed and purified N-terminal domain of PrpA was able to bind to the extracellular matrix proteins fibrinogen and fibronectin. In addition, the N-terminal domain of PrpA interacted with both non-activated and activated platelets. PMID:26675410
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Guzmán Prieto, Ana M; Urbanus, Rolf T; Zhang, Xinglin; Bierschenk, Damien; Koekman, C Arnold; van Luit-Asbroek, Miranda; Ouwerkerk, Janneke P; Pape, Marieke; Paganelli, Fernanda L; Wobser, Dominique; Huebner, Johannes; Hendrickx, Antoni P A; Bonten, Marc J M; Willems, Rob J L; van Schaik, Willem
2015-12-17
Enterococcus faecium is a commensal of the mammalian gastrointestinal tract, but is also found in non-enteric environments where it can grow between 10 °C and 45 °C. E. faecium has recently emerged as a multi-drug resistant nosocomial pathogen. We hypothesized that genes involved in the colonization and infection of mammals exhibit temperature-regulated expression control and we therefore performed a transcriptome analysis of the clinical isolate E. faecium E1162, during mid-exponential growth at 25 °C and 37 °C. One of the genes that exhibited differential expression between 25 °C and 37 °C, was predicted to encode a peptidoglycan-anchored surface protein. The N-terminal domain of this protein is unique to E. faecium and closely related enterococci, while the C-terminal domain is homologous to the Streptococcus agalactiae surface protein BibA. This region of the protein contains proline-rich repeats, leading us to name the protein PrpA for proline-rich protein A. We found that PrpA is a surface-exposed protein which is most abundant during exponential growth at 37 °C in E. faecium E1162. The heterologously expressed and purified N-terminal domain of PrpA was able to bind to the extracellular matrix proteins fibrinogen and fibronectin. In addition, the N-terminal domain of PrpA interacted with both non-activated and activated platelets.
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Attachment of Escherichia coli and enterococci to particles in runoff.
Soupir, Michelle L; Mostaghimi, Saied; Dillaha, Theo
2010-01-01
Association of Escherichia coli and enterococci with particulates present in runoff from erodible soils has important implications for modeling the fate and transport of bacteria from agricultural sources and in the selection of management practices to reduce bacterial movement to surface waters. Three soils with different textures were collected from the Ap horizon (silty loam, silty clay loam, and loamy fine sand), placed in portable box plots, treated with standard cowpats, and placed under a rainfall simulator. Rainfall was applied to the plots until saturation-excess flow occurred for 30 min, and samples were collected 10, 20, and 30 min after initiation of the runoff event. The attachment of E. coli and enterococci to particles present in runoff was determined by a screen filtration and centrifugation procedure. Percentage of E. coli and enterococci attached to particulates in runoff ranged from 28 to 49%, with few statistically significant differences in attachment among the three soils. Similar partitioning release patterns were observed between E. coli and enterococci from the silty loam (r = 0.57) and silty clay loam soils (r = 0.60). At least 60% of all attached E. coli and enterococci were associated particles within an 8- to 62-microm particle size category. The results indicate that the majority of fecal bacteria attach to and are transported with manure colloids in sediment-laden flow regardless of the soil texture.
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Recovery of diverse microbes in high turbidity surface water samples using dead-end ultrafiltration
Mull, Bonnie; Hill, Vincent R.
2015-01-01
Dead-end ultrafiltration (DEUF) has been reported to be a simple, field-deployable technique for recovering bacteria, viruses, and parasites from large-volume water samples for water quality testing and waterborne disease investigations. While DEUF has been reported for application to water samples having relatively low turbidity, little information is available regarding recovery efficiencies for this technique when applied to sampling turbid water samples such as those commonly found in lakes and rivers. This study evaluated the effectiveness of a DEUF technique for recoveringMS2 bacteriophage, enterococci, Escherichia coli, Clostridium perfringens, and Cryptosporidium parvum oocysts in surface water samples having elevated turbidity. Average recovery efficiencies for each study microbe across all turbidity ranges were: MS2 (66%), C. parvum (49%), enterococci (85%), E. coli (81%), and C. perfringens (63%). The recovery efficiencies for MS2 and C. perfringens exhibited an inversely proportional relationship with turbidity, however no significant differences in recovery were observed for C. parvum, enterococci, or E. coli. Although ultrafilter clogging was observed, the DEUF method was able to process 100-L surface water samples at each turbidity level within 60 min. This study supports the use of the DEUF method for recovering a wide array of microbes in large-volume surface water samples having medium to high turbidity. PMID:23064261
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Recovery of diverse microbes in high turbidity surface water samples using dead-end ultrafiltration.
Mull, Bonnie; Hill, Vincent R
2012-12-01
Dead-end ultrafiltration (DEUF) has been reported to be a simple, field-deployable technique for recovering bacteria, viruses, and parasites from large-volume water samples for water quality testing and waterborne disease investigations. While DEUF has been reported for application to water samples having relatively low turbidity, little information is available regarding recovery efficiencies for this technique when applied to sampling turbid water samples such as those commonly found in lakes and rivers. This study evaluated the effectiveness of a DEUF technique for recovering MS2 bacteriophage, enterococci, Escherichia coli, Clostridium perfringens, and Cryptosporidium parvum oocysts in surface water samples having elevated turbidity. Average recovery efficiencies for each study microbe across all turbidity ranges were: MS2 (66%), C. parvum (49%), enterococci (85%), E. coli (81%), and C. perfringens (63%). The recovery efficiencies for MS2 and C. perfringens exhibited an inversely proportional relationship with turbidity, however no significant differences in recovery were observed for C. parvum, enterococci, or E. coli. Although ultrafilter clogging was observed, the DEUF method was able to process 100-L surface water samples at each turbidity level within 60 min. This study supports the use of the DEUF method for recovering a wide array of microbes in large-volume surface water samples having medium to high turbidity. Published by Elsevier B.V.
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Effects of Full-Scale Beach Renovation on Fecal Indicator Levels in Shoreline Sand and Water
Hernandez, Rafael J.; Hernandez, Yasiel; Jimenez, Nasly H.; Piggot, Alan M.; Klaus, James S.; Feng, Zhixuan; Reniers, Ad; Solo-Gabriele, Helena M.
2013-01-01
Recolonization of enterococci, at a non-point source beach known to contain high background levels of bacteria, was studied after a full-scale beach renovation project. The renovation involved importation of new exogenous sand, in addition to infrastructure improvements. The study's objectives were to document changes in sand and water quality and to evaluate the relative contribution of different renovation activities towards these changes. These objectives were addressed: by measuring enterococci levels in the sand and fecal indicator bacteria levels (enterococci and fecal coliform) in the water, by documenting sediment characteristics (mineralogy and biofilm levels), and by estimating changes in observable enterococci loads. Analysis of enterococci levels on surface sand and within sediment depth cores were significantly higher prior to beach renovation (6.3 to 72 CFU/g for each sampling day) when compared to levels during and after beach renovation (0.8 CFU/g to 12 CFU/g) (p<0.01). During the renovation process, sand enterococci levels were frequently below detection limits (<0.1 CFU/g). For water, exceedances in the regulatory thresholds that would trigger a beach advisory decreased by 40% for enterococci and by 90% for fecal coliform. Factors that did not change significantly between pre- and post- renovation included the enterococci loads from animals (approx. 3 × 1011 CFU per month). Factors that were observed to change between pre- and post- renovation activities included: the composition of the beach sand (64% versus 98% quartz, and a significant decrease in biofilm levels) and loads from direct stormwater inputs (reduction of 3 × 1011 CFU per month). Overall, this study supports that beach renovation activities contributed to improved sand and water quality resulting in a 50% decrease of observable enterococci loads due to upgrades to the stormwater infrastructure. Of interest was that the change in the sand mineralogy also coincided with changes in biofilm levels. More work is needed to evaluate the relationships between beach sand mineralogy, biofilm characteristics, and the retention of fecal indicator bacteria in sand. PMID:24183401
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Effects of full-scale beach renovation on fecal indicator levels in shoreline sand and water.
Hernandez, Rafael J; Hernandez, Yasiel; Jimenez, Nasly H; Piggot, Alan M; Klaus, James S; Feng, Zhixuan; Reniers, Ad; Solo-Gabriele, Helena M
2014-01-01
Recolonization of enterococci, at a non-point source beach known to contain high background levels of bacteria, was studied after a full-scale beach renovation project. The renovation involved importation of new exogenous sand, in addition to infrastructure improvements. The study's objectives were to document changes in sand and water quality and to evaluate the relative contribution of different renovation activities towards these changes. These objectives were addressed: by measuring enterococci levels in the sand and fecal indicator bacteria levels (enterococci and fecal coliform) in the water, by documenting sediment characteristics (mineralogy and biofilm levels), and by estimating changes in observable enterococci loads. Analysis of enterococci levels on surface sand and within sediment depth cores were significantly higher prior to beach renovation (6.3-72 CFU/g for each sampling day) when compared to levels during and after beach renovation (0.8-12 CFU/g) (P < 0.01). During the renovation process, sand enterococci levels were frequently below detection limits (<0.1 CFU/g). For water, exceedances in the regulatory thresholds that would trigger a beach advisory decreased by 40% for enterococci and by 90% for fecal coliform. Factors that did not change significantly between pre- and post- renovation included the enterococci loads from animals (approx. 3 × 10(11) CFU per month). Factors that were observed to change between pre- and post- renovation activities included: the composition of the beach sand (64% versus 98% quartz, and a significant decrease in biofilm levels) and loads from direct stormwater inputs (reduction of 3 × 10(11) CFU per month). Overall, this study supports that beach renovation activities contributed to improved sand and water quality resulting in a 50% decrease of observable enterococci loads due to upgrades to the stormwater infrastructure. Of interest was that the change in the sand mineralogy also coincided with changes in biofilm levels. More work is needed to evaluate the relationships between beach sand mineralogy, biofilm characteristics, and the retention of fecal indicator bacteria in sand. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Hamilton, Elizabeth; Kaneene, John B; May, Katherine J; Kruger, John M; Schall, William; Beal, Matthew W; Hauptman, Joe G; DeCamp, Charles E
2012-06-15
To determine the prevalence and antimicrobial resistance of enterococci and staphylococci collected from environmental surfaces at a veterinary teaching hospital (VTH). Longitudinal study. Samples collected from surfaces in 5 areas (emergency and critical care, soft tissue and internal medicine, and orthopedic wards; surgery preparation and recovery rooms; and surgery office and operating rooms) of a VTH. Selected surfaces were swabbed every 3 months during the 3-year study period (2007 to 2009). Isolates of enterococci and staphylococci were identified via biochemical tests, and antimicrobial susceptibility was evaluated with a microbroth dilution technique. A subset of isolates was analyzed to assess clonality by use of pulsed-field gel electrophoresis. 430 samples were collected, and isolates of enterococci (n = 75) and staphylococci (110) were identified. Surfaces significantly associated with isolation of Enterococcus spp and Staphylococcus spp included cages and a weight scale. Fourteen Enterococcus spp isolates and 17 Staphylococcus spp isolates were resistant to ≥ 5 antimicrobials. Samples collected from the scale throughout the study suggested an overall increase in antimicrobial resistance of Enterococcus faecium over time. Clonality was detected for E faecium isolates collected from 2 different surfaces on the same day. Although not surprising, the apparent increase in antimicrobial resistance of E faecium was of concern because of the organism's ability to transmit antimicrobial resistance genes to other pathogens. Results reported here may aid in identification of critical control points to help prevent the spread of pathogens in VTHs.
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Amachawadi, R. G.; Alvarado, C. A.; Mainini, T. R.; Vinasco, J.; Drouillard, J. S.; Nagaraja, T. G.
2013-01-01
Copper, an essential micronutrient, is supplemented in the diet at elevated levels to reduce morbidity and mortality and to promote growth in feedlot cattle. Gut bacteria exposed to copper can acquire resistance, which among enterococci is conferred by a transferable copper resistance gene (tcrB) borne on a plasmid. The present study was undertaken to investigate whether the feeding of copper at levels sufficient to promote growth increases the prevalence of the tcrB gene among the fecal enterococci of feedlot cattle. The study was performed with 261 crossbred yearling heifers housed in 24 pens, with pens assigned randomly to a 2×2 factorial arrangement of treatments consisting of dietary copper and a commercial linseed meal-based energy protein supplement. A total of 22 isolates, each identified as Enterococcus faecium, were positive for tcrB with an overall prevalence of 3.8% (22/576). The prevalence was higher among the cattle fed diets supplemented with copper (6.9%) compared to normal copper levels (0.7%). The tcrB-positive isolates always contained both erm(B) and tet(M) genes. Median copper MICs for tcrB-positive and tcrB-negative enterococci were 22 and 4 mM, respectively. The transferability of the tcrB gene was demonstrated via a filter-mating assay. Multilocus variable number tandem repeat analysis revealed a genetically diverse population of enterococci. The finding of a strong association between the copper resistance gene and other antibiotic (tetracycline and tylosin) resistance determinants is significant because enterococci remain potential pathogens and have the propensity to transfer resistance genes to other bacteria in the gut. PMID:23666328
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Knelson, Lauren P.; Williams, David A.; Gergen, Maria F.; Rutala, William A.; Weber, David J.; Sexton, Daniel J.; Anderson, Deverick J.
2014-01-01
A total of 1,023 environmental surfaces were sampled from 45 rooms with patients infected or colonized with methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant enterococci (VRE) before terminal room cleaning. Colonized patients had higher median total target colony-forming units (CFU) of MRSA or VRE than did infected patients (median, 25 CFU [interquartile range, 0–106 CFU] vs 0 CFU [interquartile range, 0–29 CFU]; P = .033). PMID:24915217
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Landmeyer, James E.; Garigen, Thomas J.
2016-06-24
The positive relation observed between turbidity and Enterococcus concentrations in surface water at the water-quality data collection station located in the channel that drains a freshwater swamp may be attributed to bacterial survival in the abundant channel bed sediments that characterized this more naturalized area. Surface-water bed sediments collected near each water-quality data collection station and the surf zone were incubated in static microcosms in the laboratory and analyzed for Enterococcus concentrations over time. Enterococcus concentrations continued to persist in bed sediments collected in the channel that drains the swamp even after almost 4 months of incubation. Conversely, enterococci were not observed to persist in bed sediments characterized by high specific conductance. Although it is currently (2016) unknown whether this persistence of enterococci demonstrates growth or viability, the data indicate that enterococci can exist in channel bed-sediment environments outside of a host for a long time. This observation confirms previous reports that challenge the use of Enterococcus concentrations as an indicator of the recent introduction of fecal-related material and the associated acute risk to other pathogens.
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Radhouani, Hajer; Poeta, Patrícia; Pinto, Luís; Miranda, Júlio; Coelho, Céline; Carvalho, Carlos; Rodrigues, Jorge; López, María; Torres, Carmen; Vitorino, Rui; Domingues, Pedro; Igrejas, Gilberto
2010-09-21
Enterococci have emerged as the third most common cause of nosocomial infections, requiring bactericidal antimicrobial therapy. Although vancomycin resistance is a major problem in clinics and has emerged in an important extend in farm animals, few studies have examined it in wild animals. To determine the prevalence of vanA-containing Enterococcus strains among faecal samples of Seagulls (Larus cachinnans) of Berlengas Natural Reserve of Portugal, we developed a proteomic approach integrated with genomic data. The purpose was to detect the maximum number of proteins that vary in different enterococci species which are thought to be connected in some, as yet unknown, way to antibiotic resistance. From the 57 seagull samples, 54 faecal samples showed the presence of Enterococcus isolates (94.7%). For the enterococci, E. faecium was the most prevalent species in seagulls (50%), followed by E. faecalis and E. durans (10.4%), and E. hirae (6.3%). VanA-containing enterococcal strains were detected in 10.5% of the 57 seagull faecal samples studied. Four of the vanA-containing enterococci were identified as E. faecium and two as E. durans. The tet(M) gene was found in all five tetracycline-resistant vanA strains. The erm(B) gene was demonstrated in all six erythromycin-resistant vanA strains. The hyl virulence gene was detected in all four vanA-containing E. faecium isolates in this study, and two of them harboured the purK1 allele. In addition these strains also showed ampicillin and ciprofoxacin resistance. The whole-cell proteomic profile of vanA-containing Enterococcus strains was applied to evaluate the discriminatory power of this technique for their identification. The major differences among species-specific profiles were found in the positions corresponding to 97-45 kDa. Sixty individualized protein spots for each vanA isolate was identified and suitable for peptide mass fingerprinting measures by spectrometry measuring (MALDI/TOF MS) and their identification through bioinformatic databases query. The proteins were classified in different groups according to their biological function: protein biosynthesis, ATP synthesis, glycolysis, conjugation and antibiotic resistance. Taking into account the origin of these strains and its relation to infectious processes in humans and animals, it is important to explore the proteome of new strains which might serve as protein biomarkers for biological activity. The comprehensive description of proteins isolated from vancomycin-resistant Enterococcus faecium and E. durans may provide new targets for development of antimicrobial agents. This knowledge may help to identify new biomarkers of antibiotic resistance and virulence factors.
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2010-01-01
Background Enterococci have emerged as the third most common cause of nosocomial infections, requiring bactericidal antimicrobial therapy. Although vancomycin resistance is a major problem in clinics and has emerged in an important extend in farm animals, few studies have examined it in wild animals. To determine the prevalence of vanA-containing Enterococcus strains among faecal samples of Seagulls (Larus cachinnans) of Berlengas Natural Reserve of Portugal, we developed a proteomic approach integrated with genomic data. The purpose was to detect the maximum number of proteins that vary in different enterococci species which are thought to be connected in some, as yet unknown, way to antibiotic resistance. Results From the 57 seagull samples, 54 faecal samples showed the presence of Enterococcus isolates (94.7%). For the enterococci, E. faecium was the most prevalent species in seagulls (50%), followed by E. faecalis and E. durans (10.4%), and E. hirae (6.3%). VanA-containing enterococcal strains were detected in 10.5% of the 57 seagull faecal samples studied. Four of the vanA-containing enterococci were identified as E. faecium and two as E. durans. The tet(M) gene was found in all five tetracycline-resistant vanA strains. The erm(B) gene was demonstrated in all six erythromycin-resistant vanA strains. The hyl virulence gene was detected in all four vanA-containing E. faecium isolates in this study, and two of them harboured the purK1 allele. In addition these strains also showed ampicillin and ciprofoxacin resistance. The whole-cell proteomic profile of vanA-containing Enterococcus strains was applied to evaluate the discriminatory power of this technique for their identification. The major differences among species-specific profiles were found in the positions corresponding to 97-45 kDa. Sixty individualized protein spots for each vanA isolate was identified and suitable for peptide mass fingerprinting measures by spectrometry measuring (MALDI/TOF MS) and their identification through bioinformatic databases query. The proteins were classified in different groups according to their biological function: protein biosynthesis, ATP synthesis, glycolysis, conjugation and antibiotic resistance. Taking into account the origin of these strains and its relation to infectious processes in humans and animals, it is important to explore the proteome of new strains which might serve as protein biomarkers for biological activity. Conclusions The comprehensive description of proteins isolated from vancomycin-resistant Enterococcus faecium and E. durans may provide new targets for development of antimicrobial agents. This knowledge may help to identify new biomarkers of antibiotic resistance and virulence factors. PMID:20858227
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Kara, Ahu; Devrim, İlker; Bayram, Nuri; Katipoğlu, Nagehan; Kıran, Ezgi; Oruç, Yeliz; Demiray, Nevbahar; Apa, Hurşit; Gülfidan, Gamze
2015-01-01
Vancomycin-resistant enterococci colonization has been reported to increase the risk of developing infections, including bloodstream infections. In this study, we aimed to share our experience with the vancomycin-resistant enterococci bloodstream infections following gastrointestinal vancomycin-resistant enterococci colonization in pediatric population during a period of 18 months. A retrospective cohort of children admitted to a 400-bed tertiary teaching hospital in Izmir, Turkey whose vancomycin-resistant enterococci colonization was newly detected during routine surveillances for gastrointestinal vancomycin-resistant enterococci colonization during the period of January 2009 and December 2012 were included in this study. All vancomycin-resistant enterococci isolates found within 18 months after initial detection were evaluated for evidence of infection. Two hundred and sixteen patients with vancomycin-resistant enterococci were included in the study. Vancomycin-resistant enterococci colonization was detected in 136 patients (62.3%) while they were hospitalized at intensive care units; while the remaining majority (33.0%) were hospitalized at hematology-oncology department. Vancomycin-resistant enterococci bacteremia was present only in three (1.55%) patients. All these patients were immunosuppressed due to human immunodeficiency virus (one patient) and intensive chemotherapy (two patients). In conclusion, our study found that 1.55% of vancomycin-resistant enterococci-colonized children had developed vancomycin-resistant enterococci bloodstream infection among the pediatric intensive care unit and hematology/oncology patients; according to our findings, we suggest that immunosupression is the key point for developing vancomycin-resistant enterococci bloodstream infections. Copyright © 2014 Elsevier Editora Ltda. All rights reserved.
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Recovery of vancomycin-resistant enterococci on fingertips and environmental surfaces.
Noskin, G A; Stosor, V; Cooper, I; Peterson, L R
1995-10-01
To determine the recovery of vancomycin-resistant enterococci (VRE) on fingertips, gloved fingertips, and environmental surfaces commonly encountered in the healthcare setting, and to examine the importance of handwashing on the removal of these organisms. Two clinical isolates of VRE (Enterococcus faecalis and Enterococcus faecium) were inoculated onto the hands of healthy human volunteers and the following environmental surfaces: countertops, bedrails, telephones, and stethoscopes. Following inoculation, samples were obtained at various time intervals to determine rates of recovery of organisms. To evaluate the effects of handwashing on enterococcal recovery, two different soap preparations were tested. Hands were washed with water alone or with one of the soaps and water. The soap and water studies were performed with a 5-second and a 30-second wash. Both enterococcal strains survived for at least 60 minutes on gloved and ungloved fingertips. The E faecalis was recoverable from countertops for 5 days; the E faecium persisted for 7 days. For bedrails, both enterococcal species survived for 24 hours without significant reduction in colony counts. The bacteria persisted for 60 minutes on the telephone handpiece and for 30 minutes on the diaphragmatic surface of the stethoscope. A 5-second wash with water alone resulted in virtually no change in recovery of enterococci; a 30-second wash with water plus either soap was necessary to eradicate the bacteria from hands completely. VRE are capable of prolonged survival on hands, gloves, and environmental surfaces. Hands should be washed thoroughly and gloves removed following contact with patients infected or colonized with these multidrug-resistant bacteria. Finally, environmental surfaces may serve as potential reservoirs for nosocomial transmission of VRE and need to be considered when formulating institutional infection control policies.
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Taučer-Kapteijn, Maja; Hoogenboezem, Wim; Heiliegers, Laura; de Bolster, Danny; Medema, Gertjan
2016-07-01
The emergence of clinical enterococcal isolates that are resistant to both ampicillin and vancomycin is a cause of great concern, as therapeutic alternatives for the treatment of infections caused by such organisms are becoming limited. Aquatic environments could play a role in the dissemination of antibiotic resistant enterococci. This study investigated the presence of ampicillin and vancomycin resistant enterococci in the treated effluent of six wastewater treatment plants (WWTPs) and in surface water used as a source for drinking water production in the Netherlands. Membrane filtration in combination with selective media with ampicillin or vancomycin was applied to determine the presence of ampicillin resistant Enterococcus (ARE) and vancomycin resistant Enterococcus (VRE) species. Ampicillin resistant Enterococcus faecium (minimal inhibitory concentration (MIC) >16μg/mL; n=1033) was observed in all studied WWTP effluents. In surface water used for drinking water production (intake locations), no ARE or VRE were observed. At both types of location, intrinsic vancomycin resistant Pediococcus spp., Leuconostoc spp. and Lactobacillus spp. were isolated with the vancomycin medium. The ampicillin resistant E. faecium (AREfm) isolates (n=113) did not contain the vanA or vanB gene, but MIC testing for vancomycin showed intermediate vancomycin resistance (2-8μgmL(-1)) to occur in these AREfm strains. This study documents the discharge of ampicillin resistant E. faecium strains with intermediate vancomycin resistance by the WWTPs into the surface water, but no presence of these strains downstream at intake locations for drinking water production. Copyright © 2016 Elsevier GmbH. All rights reserved.
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Multi-scale Landscape Factors Influencing Stream Water Quality in the State of Oregon
Enterococci bacteria are used to indicate the presence of human and/or animal fecal materials in surface water. In addition to human influences on the quality of surface water, a cattle grazing is a widespread and persistent ecological stressor in the Western United States. Cattl...
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Relationships Between Sand and Water Quality at Recreational Beaches
Phillips, Matthew C.; Solo-Gabriele, Helena M.; Piggot, Alan M.; Klaus, James S.; Zhang, Yifan
2011-01-01
Enterococci are used to assess the risk of negative human health impacts from recreational waters. Studies have shown sustained populations of enterococci within sediments of beaches but comprehensive surveys of multiple tidal zones on beaches in a regional area and their relationship to beach management decisions are limited. We sampled three tidal zones on eight South Florida beaches in Miami-Dade and Broward counties and found that enterococci were ubiquitous within South Florida beach sands although their levels varied greatly both among the beaches and between the supratidal, intertidal and subtidal zones. The supratidal sands consistently had significantly higher (p<0.003) levels of enterococci (average 40 CFU/g dry sand) than the other two zones. Levels of enterococci within the subtidal sand correlated with the average level of enterococci in the water (CFU/100mL) for the season during which samples were collected (rs= 0.73). The average sand enterococci content over all the zones on each beach correlated with the average water enterococci levels of the year prior to sand samplings (rs=0.64) as well as the average water enterococci levels for the month after sand samplings (rs=0.54). Results indicate a connection between levels of enterococci in beach water and sands throughout South Florida’s beaches and suggest that the sands are one of the predominant reservoirs of enterococci impacting beach water quality. As a result, beaches with lower levels of enterococci in the sand had fewer exceedences relative to beaches with higher levels of sand enterococci. More research should focus on evaluating beach sand quality as a means to predict and regulate marine recreational water quality. PMID:22071324
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Relationships between sand and water quality at recreational beaches.
Phillips, Matthew C; Solo-Gabriele, Helena M; Piggot, Alan M; Klaus, James S; Zhang, Yifan
2011-12-15
Enterococci are used to assess the risk of negative human health impacts from recreational waters. Studies have shown sustained populations of enterococci within sediments of beaches but comprehensive surveys of multiple tidal zones on beaches in a regional area and their relationship to beach management decisions are limited. We sampled three tidal zones on eight South Florida beaches in Miami-Dade and Broward counties and found that enterococci were ubiquitous within South Florida beach sands although their levels varied greatly both among the beaches and between the supratidal, intertidal and subtidal zones. The supratidal sands consistently had significantly higher (p < 0.003) levels of enterococci (average 40 CFU/g dry sand) than the other two zones. Levels of enterococci within the subtidal sand correlated with the average level of enterococci in the water (CFU/100mL) for the season during which samples were collected (r(s) = 0.73). The average sand enterococci content over all the zones on each beach correlated with the average water enterococci levels of the year prior to sand samplings (r(s) = 0.64) as well as the average water enterococci levels for the month after sand samplings (r(s) = 0.54). Results indicate a connection between levels of enterococci in beach water and sands throughout South Florida's beaches and suggest that the sands are one of the predominant reservoirs of enterococci impacting beach water quality. As a result, beaches with lower levels of enterococci in the sand had fewer exceedences relative to beaches with higher levels of sand enterococci. More research should focus on evaluating beach sand quality as a means to predict and regulate marine recreational water quality. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Brodsky, M H; Schiemann, D A
1976-01-01
Pfizer selective enterococcus (PSE) and KF agars were compared for their recovery of fecal streptococci from sewage effluent on membrane filters. The results showed that PSE agar is highly selective for the enterococci. The tan color resulting from esculin hydrolysis, which was not always visible on the surfaces of the colonies, is not considered a necessary differential characteristic on PSE agar since more than 90% of all colonies recovered on membrane filters were confirmed as fecal streptococci and 86% were confirmed as enterococci. The detection of esculin hydrolysis on membrane filters was not improved by using the new Millipore type HC filter. KF agar recovered significantly greater numbers of organisms but was not as selective, with 83% of the typical colonies being confirmed as fecal streptococci and 54% as enterococci. An attempt to improve the selectivity of KF agar while retaining its inclusiveness by incubation at 45 C was not successful. PMID:818956
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NASA Astrophysics Data System (ADS)
Allocca, V.; Celico, F.; Petrella, E.; Marzullo, G.; Naclerio, G.
2008-07-01
Limestone aquifers in Southern Italy are often affected by bacterial contamination produced by pasture and agriculture. The main goals of this study were (1) to analyze the role of land use and environmental factors on microbial contamination and, (2) to identify, at field scale, the most suitable indicator of fecal pollution, by comparing fecal coliforms and fecal enterococci. Analyzing surface and spring water, it was noted that both fecal indicators showed a significant decrease during the period characterized by freezing and/or freeze-thaw intervals. The data analysis shows that fecal coliforms are characterized by a significant decrease in population (3 orders of magnitude, at least) during the freezing period, while fecal enterococci are temporarily inhibited. A taxonomic classification of fecal enterococci detected in spring water samples was performed by the API 20 Strep system and by sequencing of the ribosomal 16S DNA genes. The results showed that freezing conditions did not cause any significant change on the set of enterococcal species.
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Cattle grazing is a widespread and persistent ecological stressor in the Western United States. Cattle impact surface water quality by introducing nutrients and bacteria and indirectly damaging stream banks or removing vegetation cover leading to increased sediment loads and incr...
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Contribution of Sand-Associated Enterococci to Dry Weather Water Quality
2015-01-01
Culturable enterococci and a suite of environmental variables were collected during a predominantly dry summer at a beach impacted by nonpoint source pollution. These data were used to evaluate sands as a source of enterococci to nearshore waters, and to assess the relationship between environmental factors and dry-weather enterococci abundance. Best-fit multiple linear regressions used environmental variables to explain more than half of the observed variation in enterococci in water and dry sands. Notably, during dry weather the abundance of enterococci in dry sands at the mean high-tide line was significantly positively related to sand moisture content (ranging from <1–4%), and the daily mean ENT in water could be predicted by a linear regression with turbidity alone. Temperature was also positively correlated with ENT abundance in this study, which may indicate an important role of seasonal warming in temperate regions. Inundation by spring tides was the primary rewetting mechanism that sustained culturable enterococci populations in high-tide sands. Tidal forcing modulated the abundance of enterococci in the water, as both turbidity and enterococci were elevated during ebb and flood tides. The probability of samples violating the single-sample maximum was significantly greater when collected during periods with increased tidal range: spring ebb and flood tides. Tidal forcing also affected groundwater mixing zones, mobilizing enterococci from sand to water. These data show that routine monitoring programs using discrete enterococci measurements may be biased by tides and other environmental factors, providing a flawed basis for beach closure decisions. PMID:25479559
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Contribution of sand-associated enterococci to dry weather water quality.
Halliday, Elizabeth; Ralston, David K; Gast, Rebecca J
2015-01-06
Culturable enterococci and a suite of environmental variables were collected during a predominantly dry summer at a beach impacted by nonpoint source pollution. These data were used to evaluate sands as a source of enterococci to nearshore waters, and to assess the relationship between environmental factors and dry-weather enterococci abundance. Best-fit multiple linear regressions used environmental variables to explain more than half of the observed variation in enterococci in water and dry sands. Notably, during dry weather the abundance of enterococci in dry sands at the mean high-tide line was significantly positively related to sand moisture content (ranging from <1-4%), and the daily mean ENT in water could be predicted by a linear regression with turbidity alone. Temperature was also positively correlated with ENT abundance in this study, which may indicate an important role of seasonal warming in temperate regions. Inundation by spring tides was the primary rewetting mechanism that sustained culturable enterococci populations in high-tide sands. Tidal forcing modulated the abundance of enterococci in the water, as both turbidity and enterococci were elevated during ebb and flood tides. The probability of samples violating the single-sample maximum was significantly greater when collected during periods with increased tidal range: spring ebb and flood tides. Tidal forcing also affected groundwater mixing zones, mobilizing enterococci from sand to water. These data show that routine monitoring programs using discrete enterococci measurements may be biased by tides and other environmental factors, providing a flawed basis for beach closure decisions.
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ERIC Educational Resources Information Center
Middleton, June
2007-01-01
Bacteriocins, bacteriocidal proteins produced by bacteria, have a very restricted killing range. In this exercise each student isolates an environmental "Enterococcus spp." culture using selective media and then evaluates it for bacteriocin activity against "Enterococcus" strains isolated by classmates.
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Enterococci are common members of the gut microbiome and frequent causative agents of nosocomial infection. Because of their enteric lifestyle and ease of culturing, enterococci have been used worldwide as indicators of fecal pollution of waters. However, enterococci were recentl...
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Hodgson, Christopher J; Oliver, David M; Fish, Robert D; Bulmer, Nicholas M; Heathwaite, A Louise; Winter, Michael; Chadwick, David R
2016-12-01
Dairy farming generates large volumes of liquid manure (slurry), which is ultimately recycled to agricultural land as a valuable source of plant nutrients. Different methods of slurry application to land exist; some spread the slurry to the sward surface whereas others deliver the slurry under the sward and into the soil, thus helping to reduce greenhouse gas (GHG) emissions from agriculture. The aim of this study was to investigate the impact of two slurry application methods (surface broadcast versus shallow injection) on the survival of faecal indicator organisms (FIOs) delivered via dairy slurry to replicated grassland plots across contrasting seasons. A significant increase in FIO persistence (measured by the half-life of E. coli and intestinal enterococci) was observed when slurry was applied to grassland via shallow injection, and FIO decay rates were significantly higher for FIOs applied to grassland in spring relative to summer and autumn. Significant differences in the behaviour of E. coli and intestinal enterococci over time were also observed, with E. coli half-lives influenced more strongly by season of application relative to the intestinal enterococci population. While shallow injection of slurry can reduce agricultural GHG emissions to air it can also prolong the persistence of FIOs in soil, potentially increasing the risk of their subsequent transfer to water. Awareness of (and evidence for) the potential for 'pollution-swapping' is critical in order to guard against unintended environmental impacts of agricultural management decisions. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.
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Conn, K.E.; Habteselassie, M.Y.; Denene, Blackwood A.; Noble, R.T.
2012-01-01
Aims: The objective was to assess the impacts of repairing a failing onsite wastewater treatment system (OWTS, i.e., septic system) as related to coastal microbial water quality. Methods and Results: Wastewater, groundwater and surface water were monitored for environmental parameters, faecal indicator bacteria (total coliforms, Escherichia coli, enterococci) and the viral tracer MS2 before and after repairing a failing OWTS. MS2 results using plaque enumeration and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) often agreed, but inhibition limited the qRT-PCR assay sensitivity. Prerepair, MS2 persisted in groundwater and was detected in the nearby creek; postrepair, it was not detected. In groundwater, total coliform concentrations were lower and E.??coli was not detected, while enterococci concentrations were similar to prerepair levels. E.??coli and enterococci surface water concentrations were elevated both before and after the repair. Conclusions: Repairing the failing OWTS improved groundwater microbial water quality, although persistence of bacteria in surface water suggests that the OWTS was not the singular faecal contributor to adjacent coastal waters. A suite of tracers is needed to fully assess OWTS performance in treating microbial contaminants and related impacts on receiving waters. Molecular methods like qRT-PCR have potential but require optimization. Significance and Impact of Study: This is the first before and after study of a failing OWTS and provides guidance on selection of microbial tracers and methods. ?? 2011 The Authors. Journal of Applied Microbiology ?? 2011 The Society for Applied Microbiology.
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Dankovich, Theresa A.
2014-01-01
This work reports an environmentally benign method for the in situ preparation of silver nanoparticles (AgNPs) in paper using microwave irradiation. Through thermal evaporation, microwave heating with an excess of glucose relative to the silver ion precursor yields nanoparticles on the surface of cellulose fibers within three minutes. Paper sheets were characterized by electron microscopy, UV-Visible reflectance spectroscopy, and atomic absorption spectroscopy. Antibacterial activity and silver release from the AgNP sheets were assessed for model Escherichia coli and Enterococci faecalis bacteria in deionized water and in suspensions that also contained with various influent solution chemistries, i.e. with natural organic matter, salts, and proteins. The paper sheets containing silver nanoparticles were effective in inactivating the test bacteria as they passed through the paper. PMID:25400935
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Gaglio, Raimondo; Couto, Natacha; Marques, Cátia; de Fatima Silva Lopes, Maria; Moschetti, Giancarlo; Pomba, Constança; Settanni, Luca
2016-11-07
Forty enterococci isolated along the production chains of three traditional cheeses (PDO Pecorino Siciliano, PDO Vastedda della Valle del Belìce, and Caciocavallo Palermitano) made in Sicily (southern Italy) were studied for the assessment of their antibiotic resistance and virulence by a combined phenotypic/genotypic approach. A total of 31 Enterococcus displayed resistance to at least one or more of the antimicrobials tested. The strains exhibited high percentages of resistance to erythromycin (52.5%), ciprofloxacin (35.0%), quinupristin-dalfopristin (20.0%), tetracycline (17.5%), and high-level streptomycin (5.0%). The presence of tet(M), cat(pC221), and aadE genes for resistance to tetracycline, chloramphenicol, and streptomycin, respectively, was registered in all strains with resistance phenotype. The erm(B) gene was not detected in any erythromycin-resistant strain. The Enterococcus strains were further tested by PCR for the presence of virulence genes, namely, gelE, asa1, efaA, ace, and esp. Twenty strains were positive for all virulence genes tested. Among the enterococci isolated from final cheeses, three strains (representing 33.3% of total cheese strains) were sensible to all antimicrobials tested and did not carry any virulence factor. Although this study confirmed that the majority of dairy enterococci are vectors for the dissemination of antimicrobial resistance and virulence genes, only two strains showed a high resistance to aminoglycosides, commonly administered to combat enterococci responsible for human infections. Furthermore, the presence of the strains E. casseliflavus FMAC163, E. durans FMAC134B, and E. faecium PON94 without risk determinants, found at dominating levels over the Enterococcus populations in the processed products, stimulates further investigations for their future applications in cheese making. All strains devoid of the undesired traits were isolated from stretched cheeses. Thus, this cheese typology represents an interesting environment to deepen the studies on the risk/benefit role of enterococci in fermented foods for their qualified presumption of safety (QPS) assessment. Copyright © 2016 Elsevier B.V. All rights reserved.
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Goessweiner-Mohr, Nikolaus; Grumet, Lukas; Arends, Karsten; Pavkov-Keller, Tea; Gruber, Christian C.; Gruber, Karl; Birner-Gruenberger, Ruth; Kropec-Huebner, Andrea; Huebner, Johannes; Grohmann, Elisabeth; Keller, Walter
2013-01-01
Conjugative plasmid transfer is the most important means of spreading antibiotic resistance and virulence genes among bacteria and therefore presents a serious threat to human health. The process requires direct cell-cell contact made possible by a multiprotein complex that spans cellular membranes and serves as a channel for macromolecular secretion. Thus far, well studied conjugative type IV secretion systems (T4SS) are of Gram-negative (G−) origin. Although many medically relevant pathogens (e.g., enterococci, staphylococci, and streptococci) are Gram-positive (G+), their conjugation systems have received little attention. This study provides structural information for the transfer protein TraM of the G+ broad host range Enterococcus conjugative plasmid pIP501. Immunolocalization demonstrated that the protein localizes to the cell wall. We then used opsonophagocytosis as a novel tool to verify that TraM was exposed on the cell surface. In these assays, antibodies generated to TraM recruited macrophages and enabled killing of pIP501 harboring Enteroccocus faecalis cells. The crystal structure of the C-terminal, surface-exposed domain of TraM was determined to 2.5 Å resolution. The structure, molecular dynamics, and cross-linking studies indicated that a TraM trimer acts as the biological unit. Despite the absence of sequence-based similarity, TraM unexpectedly displayed a fold similar to the T4SS VirB8 proteins from Agrobacterium tumefaciens and Brucella suis (G−) and to the transfer protein TcpC from Clostridium perfringens plasmid pCW3 (G+). Based on the alignments of secondary structure elements of VirB8-like proteins from mobile genetic elements and chromosomally encoded T4SS from G+ and G− bacteria, we propose a new classification scheme of VirB8-like proteins. PMID:23188825
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Byappanahalli, Muruleedhara N.; Whitman, Richard L.; Shively, Dawn A.; Nevers, Meredith B.
2010-01-01
Quantitative polymerase chain reaction (qPCR) measurement of enterococci has been proposed as a rapid technique for assessment of beach water quality, but the response of qPCR results to environmental conditions has not been fully explored. Culture-based E. coli and enterococci have been used in empirical predictive models to characterize their responses to environmental conditions and to increase monitoring frequency and efficiency. This approach has been attempted with qPCR results only in few studies. During the summer of 2006, water samples were collected from two southern Lake Michigan beaches and the nearby river outfall (Burns Ditch) and were analyzed for enterococci by culture-based and non-culture-based (i.e., qPCR) methods, as well as culture-based E. coli. Culturable enterococci densities (log CFU/100 ml) for the beaches were significantly correlated with enterococci qPCR cell equivalents (CE) (R = 0.650, P N = 32). Enterococci CE and CFU densities were highest in Burns Ditch relative to the beach sites; however, only CFUs were significantly higher (P R = 0.565, P N = 32). Culturable E. coli and enterococci densities were significantly correlated (R = 0.682, P N = 32). Regression analyses suggested that enterococci CFU could be predicted by lake turbidity, Burns Ditch discharge, and wind direction (adjusted R2 = 0.608); enterococci CE was best predicted by Burns Ditch discharge and log-transformed lake turbidity × wave height (adjusted R2 = 0.40). In summary, our results show that analytically, the qPCR method compares well to the non-culture-based method for measuring enterococci densities in beach water and that both these approaches can be predicted by hydrometeorological conditions. Selected predictors and model results highlight the differences between the environmental responses of the two method endpoints and the potentially high variance in qPCR results
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Furtula, Vesna; Jackson, Charlene R.; Farrell, Erin Gwenn; Barrett, John B.; Hiott, Lari M.; Chambers, Patricia A.
2013-01-01
Enterococcus spp. from two poultry farms and proximate surface and ground water sites in an area of intensive poultry production were tested for resistance to 16 clinical antibiotics. Resistance patterns were compared to assess trends and possible correlations for specific antimicrobials and levels of resistance. Enterococci were detected at all 12 surface water sites and three of 28 ground water sites. Resistance to lincomycin, tetracycline, penicillin and ciprofloxacin in poultry litter isolates was high (80.3%, 65.3%, 61.1% and 49.6%, respectively). Resistance in the surface water to the same antibiotics was 87.1%, 24.1%, 7.6% and 12.9%, respectively. Overall, 86% of litter isolates, 58% of surface water isolates and 100% of ground water isolates were resistant to more than one antibiotic. Fifty-four different resistance patterns were recognised in isolates obtained from litter and environmental samples and several E. faecium and E. faecalis isolates from litter and environment samples shared the same resistance pattern. Multiple antibiotic resistant (MAR) indices calculated to assess health risks due to the presence of resistant enterococci suggested an increased presence of antibiotics in surface water, likely from poultry sources as no other wastewater contributions in the area were documented. PMID:23481592
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Whitman, Richard L.; Ge, Zhongfu; Nevers, Meredith B.; Boehm, Alexandria B.; Chern, Eunice C.; Haugland, Richard A.; Lukasik, Ashley M.; Molina, Marirosa; Przybyla-Kelly, Kasia; Shively, Dawn A.; White, Emily M.; Zepp, Richard G.; Byappanahalli, Muruleedhara N.
2010-01-01
The quantitative polymerase chain reaction (qPCR) method provides rapid estimates of fecal indicator bacteria densities that have been indicated to be useful in the assessment of water quality. Primarily because this method provides faster results than standard culture-based methods, the U.S. Environmental Protection Agency is currently considering its use as a basis for revised ambient water quality criteria. In anticipation of this possibility, we sought to examine the relationship between qPCR-based and culture-based estimates of enterococci in surface waters. Using data from several research groups, we compared enterococci estimates by the two methods in water samples collected from 37 sites across the United States. A consistent linear pattern in the relationship between cell equivalents (CCE), based on the qPCR method, and colony-forming units (CFU), based on the traditional culturable method, was significant (P 10CFU > 2.0/100 mL) while uncertainty increases at lower CFU values. It was further noted that the relative error in replicated qPCR estimates was generally higher than that in replicated culture counts even at relatively high target levels, suggesting a greater need for replicated analyses in the qPCR method to reduce relative error. Further studies evaluating the relationship between culture and qPCR should take into account analytical uncertainty as well as potential differences in results of these methods that may arise from sample variability, different sources of pollution, and environmental factors.
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Optical Properties of Three Beach Waters: Implications for Predictive Modeling of Enterococci
Sunlight plays an important role in the inactivation of fecal indicator bacteria in recreational waters. Solar radiation can explain temporal trends in bacterial counts and is commonly used as an explanatory variable in predictive models. Broadband surface radiation provides a ba...
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Pore Water Transport of Enterococci out of Beach Sediments
Phillips, Matthew C.; Solo-Gabriele, Helena M.; Reniers, Adrianus J. H. M.; Wang, John D.; Kiger, Russell T.; Abdel-Mottaleb, Noha
2011-01-01
Enterococci are used to evaluate the safety of beach waters and studies have identified beach sands as a source of these bacteria. In order to study and quantify the release of microbes from beach sediments, flow column systems were built to evaluate flow of pore water out of beach sediments. Results show a peak in enterococci (average of 10% of the total microbes in core) released from the sand core within one pore water volume followed by a marked decline to below detection. These results indicate that few enterococci are easily removed and that factors other than simple pore water flow control the release of the majority of enterococci within beach sediments. A significantly larger quantity and release of enterococci were observed in cores collected after a significant rain event suggesting the influx of fresh water can alter the release pattern as compared to cores with no antecedent rainfall. PMID:21945015
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Lysozyme activates Enterococcus faecium to induce necrotic cell death in macrophages.
Gröbner, Sabine; Fritz, Evelyn; Schoch, Friederike; Schaller, Martin; Berger, Alexander C; Bitzer, Michael; Autenrieth, Ingo B
2010-10-01
Enterococci are commensal organisms in the alimentary tract. However, they can cause a variety of life-threatening infections, especially in nosocomial settings. We hypothesized that induction of cell death might enable these facultative pathogenic bacteria to evade the innate immune response and to cause infections of their host. We demonstrate that E. faecium when exposed to lysozyme induces cell death in macrophages in vitro and in vivo. Flow cytometric analyses of J774A.1 macrophages infected with E. faecium revealed loss of cell membrane integrity indicated by uptake of propidium iodide and decrease of the inner mitochondrial transmembrane potential DeltaPsi(m). Inhibition of caspases, treatment of macrophages with cytochalasin D, or rifampicin did not prevent cells from dying, suggesting cell death mechanisms that are independent of caspase activation, bacterial uptake, and intracellular bacterial replication. Characteristics of necrotic cell death were demonstrated by both lack of procaspase 3 activation and cell shrinkage, electron microscopy, and release of lactate dehydrogenase. Pretreatment of E. faecium with lysozyme and subsequently with broad spectrum protease considerably reduced cell death, suggesting that a bacterial surface protein is causative for cell death induction. Moreover, in a mouse peritonitis model we demonstrated that E. faecium induces cell death of peritoneal macrophages in vivo. Altogether, our results show that enterococci, under specific conditions such as exposure to lysozyme, induce necrotic cell death in macrophages, which might contribute to disseminated infections by these facultative pathogenic bacteria.
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LIGHT-INDUCED PROCESSES AFFECTING ENTEROCOCCI IN AQUATIC ENVIRONMENTS
Fecal indicator bacteria such as enterococci have been used to assess contamination of freshwater and marine environments by pathogenic microorganisms. Various past studies have shown that sunlight plays an important role in reducing concentrations of culturable enterococci and ...
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Fecal pollution is measured in surface waters using culture-based measurements of enterococci and Escherichia coli bacteria. Source apportionment of these two fecal indicator bacteria is an urgent need for prioritizing remediation efforts and quantifying health risks associated...
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OCCURRENCE OF INTRINSIC VANCOMYCIN RESISTANT ENTEROCOCCI IN ANIMAL FECES
A survey was conducted to determine the occurrence of vancomycin resistant enterococci (VRE) in animal and human fecal samples. Fecal samples from 14 animal species and humans were analyzed by quantitative culture for enterococci and VRE. Over 800 VRE isolates were characterize...
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Freeman, Joshua T; Chen, Luke Francis; Sexton, Daniel J; Anderson, Deverick J
2011-06-01
Enterococci are a common cause of bacteremia but are also common contaminants. In our institution, approximately 17% of positive blood cultures with enterococci are mixed with skin organisms. Such isolates are probable contaminants. The specificity of the current definition of primary bloodstream infection could be increased by excluding enterococci mixed with skin organisms. Copyright © 2011 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.
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The quantitative polymerase chain reaction (qPCR) method provides rapid estimates of fecal indicator bacteria densities that have been indicated to be useful in the assessment of water quality. Primarily because this method provides faster results than standard culture-based meth...
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USDA-ARS?s Scientific Manuscript database
Microbial water quality is attracting substantial attention due to the documented role of produce in microbial food contamination, shellfish industry concerns, and recreation disruptions. In particular, irrigated produce accounted for nearly half of all food-borne illnesses in the USA from 1998 to 2...
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Enterococci are frequently used as indicators of fecal pollution in surface waters. To accelerate the identification of Enterococcus faecalis-specific DNA sequences, we employed a comparative genomic strategy utilizing a positive selection process to compare E. faec...
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Nonpoint Sources (NPS) of pollution (e.g., agriculture, wildlife, urban runoff) are major contributors of microbial contaminants to surface waters. However, little is known about the behavior and the effect of environmental determinants on molecular markers of fecal contamination...
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DETECTION OF INTRINSIC VANCOMYCIN RESISTANT ENTEROCOCCI IN ANIMAL AND HUMAN FECES
A survey was conducted to determine the occurrence of vancomycin resistant enterococci (VRE) in animal and human fecal samples. Fecal samples from 14 animal species and humans were analyzed by quantitative culture for enterococci and VRE. Over 800 VRE isolates were characterize...
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FINGERPRINTING OF FECAL ENTEROCOCCI BY MATRIX ASSISTED LASER DESORPTION IONIZATION MASS SPECTROMETRY
The fecal enterococci group has been suggested as an indicator of fecal contamination in freshwater and marine water systems and as a potential target for bacterial source tracking of fecal pollution. While many studies have described the diversity of enterococci in environmenta...
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Rice, Karen C.; Monti, Michele M.; Ettinger, Matthew R.
2005-01-01
Concentrated animal feeding operations (CAFOs) result from the consolidation of small farms with animals into larger operations, leading to a higher density of animals per unit of land on CAFOs than on small farms. The density of animals and subsequent concentration of animal wastes potentially can cause contamination of nearby ground and surface waters. This report summarizes water-quality data collected from agricultural sites in the Shenandoah Valley and Eastern Shore of Virginia. Five sites, three non-CAFO and two dairy-operation CAFO sites, were sampled in the Shenandoah Valley. Four sites, one non-CAFO and three poultry-operation CAFO sites were sampled on the Eastern Shore. All samples were collected during January and February 2004. Water samples were analyzed for the following parameters and constituents: temperature, specific conductance, pH, and dissolved oxygen; concentrations of the indicator organisms Escherichia coli (E. coli) and enterococci; bacterial isolates of E. coli, enterococci, Salmonella spp., and Campylobacter spp.; sensitivity to antibiotics of E. coli, enterococci, and Salmonella spp.; arsenic, cadmium, chromium3+, copper, nickel, and mercury; hardness, biological oxygen demand, nitrate, nitrite, ammonia, ortho-phosphate, total Kjeldahl nitrogen, chemical oxygen demand, total organic carbon, and dissolved organic carbon; and 45 dissolved organic compounds, which included a suite of antibiotic compounds.Data are presented in tables 5-21 and results of analyses of replicate samples are presented in tables 22-28. A summary of the data in tables 5-8 and 18-21 is included in the report.
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Enterococci have been widely used as indicators of fecal pollution in recreational waters. Most studies enumerate enterococci using culture-based techniques that are time consuming and do not provide information on the identity of enterococci species within a given sample. Althou...
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Sodium chloride-esculin hydrolysis test for rapid identification of enterococci.
Qadri, S M; Flournoy, D J; Qadri, S G
1987-01-01
The ability of enterococci to cause severe disease in humans and their relative resistance to chemotherapeutic agents make it desirable to rapidly differentiate these organisms from other streptococci. We developed and evaluated a test that within 2 h distinguishes enterococci from other alpha-, beta-, or nonhemolytic streptococci in a buffered solution containing 0.2% esculin and 5% sodium chloride. All 239 strains of enterococci tested gave a positive reaction within 2 h, whereas 95 of 96 isolates of other streptococci remained negative at 4 h. PMID:3597753
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Bollerslev, Anne Mette; Nauta, Maarten; Hansen, Tina Beck; Aabo, Søren
2017-01-02
Microbiological limits are widely used in food processing as an aid to reduce the exposure to hazardous microorganisms for the consumers. However, in pork, the prevalence and concentrations of Salmonella are generally low and microbiological limits are not considered an efficient tool to support hygiene interventions. The objective of the present study was to develop an approach which could make it possible to define potential risk-based microbiological limits for an indicator, enterococci, in order to evaluate the risk from potential growth of Salmonella. A positive correlation between the concentration of enterococci and the prevalence and concentration of Salmonella was shown for 6640 pork samples taken at Danish cutting plants and retail butchers. The samples were collected in five different studies in 2001, 2002, 2010, 2011 and 2013. The observations that both Salmonella and enterococci are carried in the intestinal tract, contaminate pork by the same mechanisms and share similar growth characteristics (lag phase and maximum specific growth rate) at temperatures around 5-10°C, suggest a potential of enterococci to be used as an indicator of potential growth of Salmonella in pork. Elevated temperatures during processing will lead to growth of both enterococci and, if present, also Salmonella. By combining the correlation between enterococci and Salmonella with risk modelling, it is possible to predict the risk of salmonellosis based on the level of enterococci. The risk model used for this purpose includes the dose-response relationship for Salmonella and a reduction factor to account for preparation of the fresh pork. By use of the risk model, it was estimated that the majority of salmonellosis cases, caused by the consumption of pork in Denmark, is caused by the small fraction of pork products that has enterococci concentrations above 5logCFU/g. This illustrates that our approach can be used to evaluate the potential effect of different microbiological limits and therefore, the perspective of this novel approach is that it can be used for definition of a risk-based microbiological limit for enterococci. The limit for enterococci can then be used for development of a process hygiene criterion in cutting plants and retail butcher shops, with the purpose of reducing the risk of Salmonella for the consumer. Copyright © 2016 Elsevier B.V. All rights reserved.
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Oravcova, Veronika; Mihalcin, Matus; Zakova, Jana; Pospisilova, Lucie; Masarikova, Martina; Literak, Ivan
2017-12-31
Vancomycin-resistant enterococci (VRE) are pathogens of increasing medical importance. In Brno, Czech Republic, we collected 37 samples from the effluent of a wastewater treatment plant (WWTP), 21 surface swabs from hospital settings, and 59 fecal samples from hospitalized patients and staff. Moreover, we collected 284 gull cloacal swabs from the colony situated 35km downstream the WWTP. Samples were cultured selectively. Enterococci were identified using MALDI-TOF MS, phenotypically tested for susceptibility to antibiotics, and by PCR for occurrence of resistance and virulence genes. Pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) were used to examine genotypic diversity. VRE carrying the vanA gene were found in 32 (86%, n=37) wastewater samples, from which we obtained 49 isolates: Enterococcus faecium (44) and Enterococcus gallinarum (2), Enterococcus casseliflavus (2), and Enterococcus raffinosus (1). From 33 (69%) of 48 inpatient stool samples, we obtained 39 vanA-carrying VRE, which belonged to E. faecium (33 isolates), Enterococcus faecalis (4), and Enterococcus raffinosus (2). Nearly one-third of the samples from hospital surfaces contained VRE with the vanA gene. VRE were not detected among gulls. Sixty-seven (84%, n=80) E. faecium isolates carried virulence genes hyl and/or esp. Virulence of E. faecalis was encoded by gelE, asa1, and cylA genes. A majority of the E. faecium isolates belonged to the clinically important sequence types ST17 (WWTP: 10 isolates; hospital: 4 isolates), ST18 (9;8), and ST78 (5;0). The remaining isolates belonged to ST555 (2;0), ST262 (1;6), ST273 (3;0), ST275 (1;0), ST549 (2;0), ST19 (0;1), ST323 (3;0), and ST884 (7;17). Clinically important enterococci carrying the vanA gene were almost continually detectable in the effluent of the WWTP, indicating insufficient removal of VRE during wastewater treatment and permanent shedding of these antibiotic resistant pathogens into the environment from this source. This represents a risk of their transmission to the environment. Copyright © 2017 Elsevier B.V. All rights reserved.
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DOE Office of Scientific and Technical Information (OSTI.GOV)
Carey, Stephanie Ann; Goldstein, Rachel E. Rosenberg; Gibbs, Shawn G.
Reclaiming municipal wastewater for agricultural, environmental, and industrial purposes is increasing in the United States to combat dwindling freshwater supplies. However, there is a lack of data regarding the microbial quality of reclaimed water. In particular, no previous studies have evaluated the occurrence of vancomycin-resistant enterococci (VRE) in reclaimed water used at spray irrigation sites in the United States. To address this knowledge gap, we investigated the occurrence, concentration, and antimicrobial resistance patterns of VRE and vancomycin-susceptible enterococci at three U.S. spray irrigation sites that use reclaimed water. We collected 48 reclaimed water samples from one Mid-Atlantic and two Midwestmore » spray irrigation sites, as well as their respective wastewater treatment plants, in 2009 and 2010. Samples were analyzed for total enterococci and VRE using standard membrane filtration. Isolates were purified and then confirmed using biochemical tests and PCR. Antimicrobial susceptibility testing was conducted using the Sensititre® microbroth dilution system. Data were analyzed by two-sample proportion tests and one-way analysis of variance. We detected total enterococci and VRE in 71% (34/48) and 4% (2/48) of reclaimed water samples, respectively. Enterococcus faecalis was the most common species identified. At the Mid-Atlantic spray irrigation site, UV radiation decreased total enterococci to undetectable levels; however, subsequent storage in an open-air pond at this site resulted in increased concentrations of enterococci. E. faecalis isolates recovered from the Mid-Atlantic spray irrigation site expressed intrinsic resistance to quinupristin/dalfopristin; however, non-E. faecalis isolates expressed resistance to quinupristin/dalfopristin (52% of isolates), vancomycin (4%), tetracycline (13%), penicillin (4%) and ciprofloxacin (17%). Our findings show that VRE are present in low numbers in reclaimed water at point-of-use at the sampled spray irrigation sites; however, resistance to other antimicrobial classes is more prevalent, particularly among non-E. faecalis isolates. - Highlights: • Enterococci were recovered in 71% of reclaimed water samples. • Vancomycin-resistant enterococci were detected in 4% of reclaimed water samples. • UV radiation at irrigation sites reduced enterococci to undetectable levels. • Storage of reclaimed water in open-air ponds increased levels of enterococci.« less
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Recovery of Enterococcus faecalis from cheese in the oral cavity of healthy subjects.
Razavi, A; Gmür, R; Imfeld, T; Zehnder, M
2007-08-01
Enterococci are rarely found in the healthy human oral cavity, yet they are strongly associated with filled root canals. The origin of these enterococci remains unknown. Our hypothesis is that they are transient food-born colonizers under healthy conditions. This pilot study reinvestigated the prevalence of enterococci in the oral cavity of healthy volunteers, screened cheese samples for enterococci and investigated colonization of the oral cavity after ingestion of an enterocci-positive cheese. Concentrated oral rinse samples were collected from a cohort of 50 dental students and proved negative for viable enterococci. Twenty cheese samples were obtained from local supermarkets. Enterococci were cultured and identified using standard methods. Viable enterococci were detected in one of five specimens of Swiss Tilsiter, three of five samples of French soft cheese, one of five Mozzarella samples and one of five Feta samples. Eight volunteers from the cohort consumed 10 g of a cheese with high Enterococcus faecalis load. Oral rinse samples were collected before and 1, 10 and 100 min after cheese ingestion. One minute after ingestion, a median of 5,480 E. faecalis colony-forming units was recovered from the oral rinse samples. Bacterial counts were reduced after 10 min, had dropped after 100 min to levels that were significantly (P < 0.005) different from the 1-min and 10-min scores and were below the detection limit after 1 week. These findings suggest that colonization of the healthy oral cavity by enterococci is transitional, but at the same time add weight to our hypothesis that enterococcal root canal infections could be food-borne.
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Coliphages and Gastrointestinal Illness in Recreational Waters
Benjamin-Chung, Jade; Arnold, Benjamin F.; Wade, Timothy J.; Schiff, Kenneth; Griffith, John F.; Dufour, Alfred P.; Weisberg, Stephen B.
2017-01-01
Background: Coliphages have been proposed as indicators of fecal contamination in recreational waters because they better mimic the persistence of pathogenic viruses in the environment and wastewater treatment than fecal indicator bacteria. We estimated the association between coliphages and gastrointestinal illness and compared it with the association with culturable enterococci. Methods: We pooled data from six prospective cohort studies that enrolled coastal beachgoers in California, Alabama, and Rhode Island. Water samples were collected and gastrointestinal illness within 10 days of the beach visit was recorded. Samples were tested for enterococci and male-specific and somatic coliphages. We estimated cumulative incidence ratios (CIR) for the association between swimming in water with detectable coliphage and gastrointestinal illness when human fecal pollution was likely present, not likely present, and under all conditions combined. The reference group was unexposed swimmers. We defined continuous and threshold-based exposures (coliphage present/absent, enterococci >35 vs. ≤35 CFU/100 ml). Results: Under all conditions combined, there was no association between gastrointestinal illness and swimming in water with detectable coliphage or enterococci. When human fecal pollution was likely present, coliphage and enterococci were associated with increased gastrointestinal illness, and there was an association between male-specific coliphage level and illness that was somewhat stronger than the association between enterococci and illness. There were no substantial differences between male-specific and somatic coliphage. Conclusions: Somatic coliphage and enterococci had similar associations with gastrointestinal illness; there was some evidence that male-specific coliphage had a stronger association with illness than enterococci in marine waters with human fecal contamination. PMID:28489717
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Benjamin-Chung, Jade; Arnold, Benjamin F; Wade, Timothy J; Schiff, Kenneth; Griffith, John F; Dufour, Alfred P; Weisberg, Stephen B; Colford, John M
2017-09-01
Coliphages have been proposed as indicators of fecal contamination in recreational waters because they better mimic the persistence of pathogenic viruses in the environment and wastewater treatment than fecal indicator bacteria. We estimated the association between coliphages and gastrointestinal illness and compared it with the association with culturable enterococci. We pooled data from six prospective cohort studies that enrolled coastal beachgoers in California, Alabama, and Rhode Island. Water samples were collected and gastrointestinal illness within 10 days of the beach visit was recorded. Samples were tested for enterococci and male-specific and somatic coliphages. We estimated cumulative incidence ratios (CIR) for the association between swimming in water with detectable coliphage and gastrointestinal illness when human fecal pollution was likely present, not likely present, and under all conditions combined. The reference group was unexposed swimmers. We defined continuous and threshold-based exposures (coliphage present/absent, enterococci >35 vs. ≤35 CFU/100 ml). Under all conditions combined, there was no association between gastrointestinal illness and swimming in water with detectable coliphage or enterococci. When human fecal pollution was likely present, coliphage and enterococci were associated with increased gastrointestinal illness, and there was an association between male-specific coliphage level and illness that was somewhat stronger than the association between enterococci and illness. There were no substantial differences between male-specific and somatic coliphage. Somatic coliphage and enterococci had similar associations with gastrointestinal illness; there was some evidence that male-specific coliphage had a stronger association with illness than enterococci in marine waters with human fecal contamination.
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USDA-ARS?s Scientific Manuscript database
The objective of the study was to use band-based molecular methods including BOX-PCR (Polymerase Chain Reaction) and Pulsed-Field Gel Electrophoresis (PFGE) to determine if genetically related enterococci were found among different stores, food types, or years. Enterococci were also characterized f...
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A RAPID, SPECIFIC MEMBRANE FILTRATION PROCEDURE FOR ENUMERATION OF ENTEROCOCCI IN RECREATIONAL WATER
A two-step membrane filter (MP) method with mE medium, upon which the membrane must be incubated for 48 h and then transferred to a substrate medium to differentiate enterococci, is recommended by the U.S.Environmental Protection Agency to measure enterococci in fresh and marine ...
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Tong, Juan; Lu, XueTing; Zhang, JunYa; Sui, Qianwen; Wang, Rui; Chen, Meixue; Wei, Yuansong
2017-07-01
Pharmaceutical waste sludge harbors large amounts of antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs), and it is necessary to study the reduction of ARGs and MGEs during sludge treatment. Therefore, the antibiotic resistance phenotypes and genotypes of enterococci, and the ARGs and MGEs in genomic DNA were investigated during anaerobic digestion (AD) with microwave (MW), thermal hydrolysis (TH) and ozone pretreatment. Results showed that sludge pretreatment increased the occurrence of the resistance phenotypes and genotypes of enterococci. During AD, the resistance of enterococci to macrolides decreased, except for in the MW-pretreated sludge. Horizontal gene transfer and co-occurrence of ermB and tetM in enterococci resulted in increased tetracycline resistance of enterococci throughout the sludge treatment. MGEs such as intI1, ISCR1 and Tn916/1545 had a significant effect on the distribution of ARGs. AD with pretreatment, especially TH pretreatment, resulted in greater ARGs and MGEs reduction and improved methane production. Copyright © 2017. Published by Elsevier Ltd.
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USDA-ARS?s Scientific Manuscript database
E. coli and enterococci are commonly used as pathogen indicators in surface water, however, the transport of these bacteria to drainage tiles from manure application fields and the correlation of these indicators to pathogens in this setting is poorly understood. Salmonella spp. is prevalent in poul...
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Passerat, Julien; Ouattara, Nouho Koffi; Mouchel, Jean-Marie; Rocher, Vincent; Servais, Pierre
2011-01-01
For a better understanding of the short and mid-term impacts of a combined sewer overflow (CSO) on the microbiological quality of the receiving river, we studied the composition of a CSO discharge and monitored during several hours the changes in the concentration of fecal indicator bacteria (FIB) in the impacted river water mass. The CSO occurred at the Clichy outfall (Paris agglomeration, France) in summer 2008 as a result of the most intense rainfall of the year. In 6h, 578, 705 m(3) of sewage and 124 t of suspended matter (SM) were discharged into the Seine River. The CSO contained 1.5 × 10(6)E. coli and 4.0 × 10(5) intestinal enterococci per 100 mL on average, and 77% of the E. coli were attached to SM. It was estimated that 89% of the CSO discharge was contributed by surface water runoff, and that resuspension of sewer sediment contributed to ∼75% of the SM, 10-70% of the E. coli and 40-80% of the intestinal enterococci. Directly downstream from the CSO outfall, FIB concentrations in the impacted water mass of the Seine River (2.9 × 10(5)E. coli and 7.6 × 10(4) intestinal enterococci per 100 mL) exceeded by two orders of magnitude the usual dry weather concentrations. After 13-14 h of transit, these concentrations had decreased by 66% for E. coli and 79% for intestinal enterococci. This decline was well accounted for by our estimations of dilution, decay resulting from mortality or loss of culturability and sedimentation of the attached fraction of FIB. Copyright © 2010 Elsevier Ltd. All rights reserved.
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Young, Suzanne; Nayak, Bina; Sun, Shan; Badgley, Brian D; Rohr, Jason R; Harwood, Valerie J
2016-09-15
Sewage spills can release antibiotic-resistant bacteria into surface waters, contributing to environmental reservoirs and potentially impacting human health. Vancomycin-resistant enterococci (VRE) are nosocomial pathogens that have been detected in environmental habitats, including soil, water, and beach sands, as well as wildlife feces. However, VRE harboring vanA genes that confer high-level resistance have infrequently been found outside clinical settings in the United States. This study found culturable Enterococcus faecium harboring the vanA gene in water and sediment for up to 3 days after a sewage spill, and the quantitative PCR (qPCR) signal for vanA persisted for an additional week. Culturable levels of enterococci in water exceeded recreational water guidelines for 2 weeks following the spill, declining about five orders of magnitude in sediments and two orders of magnitude in the water column over 6 weeks. Analysis of bacterial taxa via 16S rRNA gene sequencing showed changes in community structure through time following the sewage spill in sediment and water. The spread of opportunistic pathogens harboring high-level vancomycin resistance genes beyond hospitals and into the broader community and associated habitats is a potential threat to public health, requiring further studies that examine the persistence, occurrence, and survival of VRE in different environmental matrices. Vancomycin-resistant enterococci (VRE) are harmful bacteria that are resistant to the powerful antibiotic vancomycin, which is used as a last resort against many infections. This study followed the release of VRE in a major sewage spill and their persistence over time. Such events can act as a means of spreading vancomycin-resistant bacteria in the environment, which can eventually impact human health. Copyright © 2016, American Society for Microbiology. All Rights Reserved.
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Young, Suzanne; Nayak, Bina; Sun, Shan; Badgley, Brian D.; Rohr, Jason R.
2016-01-01
ABSTRACT Sewage spills can release antibiotic-resistant bacteria into surface waters, contributing to environmental reservoirs and potentially impacting human health. Vancomycin-resistant enterococci (VRE) are nosocomial pathogens that have been detected in environmental habitats, including soil, water, and beach sands, as well as wildlife feces. However, VRE harboring vanA genes that confer high-level resistance have infrequently been found outside clinical settings in the United States. This study found culturable Enterococcus faecium harboring the vanA gene in water and sediment for up to 3 days after a sewage spill, and the quantitative PCR (qPCR) signal for vanA persisted for an additional week. Culturable levels of enterococci in water exceeded recreational water guidelines for 2 weeks following the spill, declining about five orders of magnitude in sediments and two orders of magnitude in the water column over 6 weeks. Analysis of bacterial taxa via 16S rRNA gene sequencing showed changes in community structure through time following the sewage spill in sediment and water. The spread of opportunistic pathogens harboring high-level vancomycin resistance genes beyond hospitals and into the broader community and associated habitats is a potential threat to public health, requiring further studies that examine the persistence, occurrence, and survival of VRE in different environmental matrices. IMPORTANCE Vancomycin-resistant enterococci (VRE) are harmful bacteria that are resistant to the powerful antibiotic vancomycin, which is used as a last resort against many infections. This study followed the release of VRE in a major sewage spill and their persistence over time. Such events can act as a means of spreading vancomycin-resistant bacteria in the environment, which can eventually impact human health. PMID:27422829
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FRNA Bacteriophages as Viral Indicators of Faecal Contamination in Mexican Tropical Aquatic Systems.
Arredondo-Hernandez, Luis Jose Rene; Diaz-Avalos, Carlos; Lopez-Vidal, Yolanda; Castillo-Rojas, Gonzalo; Mazari-Hiriart, Marisa
2017-01-01
A particular challenge to water safety in populous intertropical regions is the lack of reliable faecal indicators to detect microbiological contamination of water, while the numerical relationships of specific viral indicators remain largely unexplored. The aim of this study was to investigate the numerical relationships of FRNA-bacteriophage genotypes, adenovirus 41, and human adenoviruses (HADV) in Mexican surface water systems to assess sewage contamination. We studied the presence of HADV, HADV41 and FRNA bacteriophage genotypes in water samples and quantified by qPCR and RT-qPCR. Virus and water quality indicator variances, as analyzed by principal component analysis and partial least squared regression, followed along the major percentiles of water faecal enterococci. FRNA bacteriophages adequately deciphered viral and point source water contamination. The strongest correlation for HADV was with FRNA bacteriophage type II, in water samples higher than the 50th percentiles of faecal enterococci, thus indicating urban pollution. FRNA bacteriophage genotypes I and III virus indicator performances were assisted by their associations with electrical conductivity and faecal enterococci. In combination, our methods are useful for inferring water quality degradation caused by sewage contamination. The methods used have potential for determining source contamination in water and, specifically, the presence of enteric viruses where clean and contaminated water have mixed.
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Survival of Enterococci and Staphylococci on Hospital Fabrics and Plastic
Neely, Alice N.; Maley, Matthew P.
2000-01-01
The transfer of gram-positive bacteria, particularly multiresistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE), among patients is a growing concern. One critical aspect of bacterial transfer is the ability of the microorganism to survive on various common hospital surfaces. The purpose of this study was to determine the survival of 22 gram-positive bacteria (vancomycin-sensitive and -resistant enterococci and methicillin-sensitive and -resistant staphylococci) on five common hospital materials: smooth 100% cotton (clothing), 100% cotton terry (towels), 60% cotton–40% polyester blend (scrub suits and lab coats), 100% polyester (privacy drapes), and 100% polypropylene plastic (splash aprons). Swatches were inoculated with 104 to 105 CFU of a microorganism, assayed daily by placing the swatches in nutritive media, and examining for growth after 48 h. All isolates survived for at least 1 day, and some survived for more than 90 days on the various materials. Smaller inocula (102) survived for shorter times but still generally for days. Antibiotic sensitivity had no consistent effect on survival. The long survival of these bacteria, including MRSA and VRE, on commonly used hospital fabrics, such as scrub suits, lab coats, and hospital privacy drapes, underscores the need for meticulous contact control procedures and careful disinfection to limit the spread of these bacteria. PMID:10655374
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FRNA Bacteriophages as Viral Indicators of Faecal Contamination in Mexican Tropical Aquatic Systems
Diaz-Avalos, Carlos; Lopez-Vidal, Yolanda; Castillo-Rojas, Gonzalo; Mazari-Hiriart, Marisa
2017-01-01
A particular challenge to water safety in populous intertropical regions is the lack of reliable faecal indicators to detect microbiological contamination of water, while the numerical relationships of specific viral indicators remain largely unexplored. The aim of this study was to investigate the numerical relationships of FRNA-bacteriophage genotypes, adenovirus 41, and human adenoviruses (HADV) in Mexican surface water systems to assess sewage contamination. We studied the presence of HADV, HADV41 and FRNA bacteriophage genotypes in water samples and quantified by qPCR and RT-qPCR. Virus and water quality indicator variances, as analyzed by principal component analysis and partial least squared regression, followed along the major percentiles of water faecal enterococci. FRNA bacteriophages adequately deciphered viral and point source water contamination. The strongest correlation for HADV was with FRNA bacteriophage type II, in water samples higher than the 50th percentiles of faecal enterococci, thus indicating urban pollution. FRNA bacteriophage genotypes I and III virus indicator performances were assisted by their associations with electrical conductivity and faecal enterococci. In combination, our methods are useful for inferring water quality degradation caused by sewage contamination. The methods used have potential for determining source contamination in water and, specifically, the presence of enteric viruses where clean and contaminated water have mixed. PMID:28114378
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Hughes, C S; Longo, E; Phillips-Jones, M K; Hussain, R
2017-08-01
A-type resistance towards "last-line" glycopeptide antibiotic vancomycin in the leading hospital acquired infectious agent, the enterococci, is the most common in the UK. Resistance is regulated by the VanR A S A two-component system, comprising the histidine sensor kinase VanS A and the partner response regulator VanR A . The nature of the activating ligand for VanS A has not been identified, therefore this work sought to identify and characterise ligand(s) for VanS A . In vitro approaches were used to screen the structural and activity effects of a range of potential ligands with purified VanS A protein. Of the screened ligands (glycopeptide antibiotics vancomycin and teicoplanin, and peptidoglycan components N-acetylmuramic acid, D-Ala-D-Ala and Ala-D-y-Glu-Lys-D-Ala-D-Ala) only glycopeptide antibiotics vancomycin and teicoplanin were found to bind VanS A with different affinities (vancomycin 70μM; teicoplanin 30 and 170μM), and were proposed to bind via exposed aromatic residues tryptophan and tyrosine. Furthermore, binding of the antibiotics induced quicker, longer-lived phosphorylation states for VanS A , proposing them as activators of type A vancomycin resistance in the enterococci. Copyright © 2017 Diamond Light Source Ltd. Published by Elsevier B.V. All rights reserved.
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Kürekci, Cemil; Önen, Sevda Pehlivanlar; Yipel, Mustafa; Aslantaş, Özkan; Gündoğdu, Aycan
2016-01-01
The aim of this study was to determine the prevalence of enterococci in cheese samples and to characterize their antimicrobial resistance profiles as well as the associated resistance genes. A total of 139 enterococci were isolated from 99 cheese samples, the isolates were identified as E. faecalis (61.2%), E. faecium (15.1%), E. gallinarum (12.9%), E. durans (5.0%), E. casseliflavis (2.9%) and E. avium (2.9%). The most frequent antimicrobial resistance observed in enterococci isolates was to lincomycin (88.5%), followed by kanamycin (84.2%), gentamycin (low level, 51.1%), rifampin (46.8%) and tetracycline (33.8%). Among the isolates, the frequencies of high level gentamycin and streptomycin resistant enterococci strains were 2.2% and 5.8%, respectively. Apart from the mentioned antibiotics, low levels of resistance to ciprofloxacin, erythromycin and chloramphenicol were found. Moreover no resistance was observed against penicillin and ampicillin. The antimicrobial resistance genes including tetM, tetL, ermB, cat, aph(3')-IIIa, ant(6)-Ia and aac(6')-Ieaph(2")-Ia were found in enterococci from Turkish cheese samples. In the current study, we provided data for antibiotic resistance and the occurrence of resistance genes among enterococci. Regulatory and quality control programs for milk and other dairy products from farms to retail outlets has to be established and strengthened to monitor trends in antimicrobial resistance among emerging food borne pathogens in Turkey.
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The detection of environmental enterococci has primarily been determined using culture-based techniques that might exclude some enterococci species as well as those that are nonculturable. To address this, the relative abundance of enterococci was examined by challenging fecal an...
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USDA-ARS?s Scientific Manuscript database
Land application of manure from tylosin-treated swine introduces tylosin-resistant enterococci, erm genes, which confer resistance to tylosin, and tylosin. This study documents the occurrence and transport of tylosin-resistant enterococci, erm genes, and tylosin in tile-drained chisel plow and no-ti...
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Fogarty, L.R.; Haack, S.K.; Wolcott, M.J.; Whitman, R.L.
2003-01-01
Aims: To evaluate the numbers and selected phenotypic and genotypic characteristics of the faecal indicator bacteria Escherichia coli and enterococci in gull faeces at representative Great Lakes swimming beaches in the United States. Methods and Results: E. coli and enterococci were enumerated in gull faeces by membrane filtration. E. coli genotypes (rep-PCR genomic profiles) and E. coli (Vitek?? GNI+) and enterococci (API?? rapid ID 32 Strep and resistance to streptomycin, gentamicin, vancomycin, tetracycline and ampicillin) phenotypes were determined for isolates obtained from gull faeces both early and late in the swimming season. Identical E. coli genotypes were obtained only from single gull faecal samples but most faecal samples yielded more than one genotype (median of eight genotypes for samples with 10 isolates). E. coli isolates from the same site that clustered at ???85% similarity were from the same sampling date and shared phenotypic characteristics, and at this similarity level there was population overlap between the two geographically isolated beach sites. Enterococcus API?? profiles varied with sampling date. Gull enterococci displayed wide variation in antibiotic resistance patterns, and high-level resistance to some antibiotics. Conclusions: Gull faeces could be a major contributor of E. coli (105-109 CFU g-1) and enterococci (104-108 CFU g-1) to Great Lakes recreational waters. E. coli and enterococci in gull faeces are highly variable with respect to their genotypic and phenotypic characteristics and may exhibit temporal or geographic trends in these features. Significance and Impact of the Study: The high degree of variation in genotypic or phenotypic characteristics of E. coli or enterococci populations within gull hosts will require extensive sampling for adequate characterization, and will influence methods that use these characteristics to determine faecal contamination sources for recreational waters.
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Estimation of Enterococci Input from Bathers and Animals on A Recreational Beach Using Camera Images
D, Wang John; M, Solo-Gabriele Helena; M, Abdelzaher Amir; E, Fleming Lora
2010-01-01
Enterococci, are used nationwide as a water quality indicator of marine recreational beaches. Prior research has demonstrated that enterococci inputs to the study beach site (located in Miami, FL) are dominated by non-point sources (including humans and animals). We have estimated their respective source functions by developing a counting methodology for individuals to better understand their non-point source load impacts. The method utilizes camera images of the beach taken at regular time intervals to determine the number of people and animal visitors. The developed method translates raw image counts for weekdays and weekend days into daily and monthly visitation rates. Enterococci source functions were computed from the observed number of unique individuals for average days of each month of the year, and from average load contributions for humans and for animals. Results indicate that dogs represent the larger source of enterococci relative to humans and birds. PMID:20381094
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Significance of beach geomorphology on fecal indicator bacteria levels.
Donahue, Allison; Feng, Zhixuan; Kelly, Elizabeth; Reniers, Ad; Solo-Gabriele, Helena M
2017-08-15
Large databases of fecal indicator bacteria (FIB) measurements are available for coastal waters. With the assistance of satellite imagery, we illustrated the power of assessing data for many sites by evaluating beach features such as geomorphology, distance from rivers and canals, presence of piers and causeways, and degree of urbanization coupled with the enterococci FIB database for the state of Florida. We found that beach geomorphology was the primary characteristic associated with enterococci levels that exceeded regulatory guidelines. Beaches in close proximity to marshes or within bays had higher enterococci exceedances in comparison to open coast beaches. For open coast beaches, greater enterococci exceedances were associated with nearby rivers and higher levels of urbanization. Piers and causeways had a minimal contribution, as their effect was often overwhelmed by beach geomorphology. Results can be used to understand the potential causes of elevated enterococci levels and to promote public health. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Mechanisms of antibiotic resistance in enterococci
Miller, William R; Munita, Jose M; Arias, Cesar A
2015-01-01
Multidrug-resistant (MDR) enterococci are important nosocomial pathogens and a growing clinical challenge. These organisms have developed resistance to virtually all antimicrobials currently used in clinical practice using a diverse number of genetic strategies. Due to this ability to recruit antibiotic resistance determinants, MDR enterococci display a wide repertoire of antibiotic resistance mechanisms including modification of drug targets, inactivation of therapeutic agents, overexpression of efflux pumps and a sophisticated cell envelope adaptive response that promotes survival in the human host and the nosocomial environment. MDR enterococci are well adapted to survive in the gastrointestinal tract and can become the dominant flora under antibiotic pressure, predisposing the severely ill and immunocompromised patient to invasive infections. A thorough understanding of the mechanisms underlying antibiotic resistance in enterococci is the first step for devising strategies to control the spread of these organisms and potentially establish novel therapeutic approaches. PMID:25199988
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Hendrickx, Antoni P A; Top, Janetta; Bayjanov, Jumamurat R; Kemperman, Hans; Rogers, Malbert R C; Paganelli, Fernanda L; Bonten, Marc J M; Willems, Rob J L
2015-11-10
The microbiota of the mammalian gastrointestinal tract is a complex ecosystem of bacterial communities that continuously interact with the mucosal immune system. In a healthy host, the mucosal immune system maintains homeostasis in the intestine and prevents invasion of pathogenic bacteria, a phenomenon termed colonization resistance. Antibiotics create dysbiosis of microbiota, thereby decreasing colonization resistance and facilitating infections caused by antibiotic-resistant bacteria. Here we describe how cephalosporin antibiotics create dysbiosis in the mouse large intestine, allowing intestinal outgrowth of antimicrobial-resistant Enterococcus faecium. This is accompanied by a reduction of the mucus-associated gut microbiota layer, colon wall, and Muc-2 mucus layer. E. faecium agglutinates intraluminally in an extracellular matrix consisting of secretory IgA (sIgA), polymeric immunoglobulin receptor (pIgR), and epithelial cadherin (E-cadherin) proteins, thereby maintaining spatial segregation of E. faecium from the intestinal wall. Addition of recombinant E-cadherin and pIgR proteins or purified IgA to enterococci in vitro mimics agglutination of E. faecium in vivo. Also, the Ca(2+) levels temporarily increased by 75% in feces of antibiotic-treated mice, which led to deformation of E-cadherin adherens junctions between colonic intestinal epithelial cells and release of E-cadherin as an extracellular matrix entrapping E. faecium. These findings indicate that during antibiotic-induced dysbiosis, the intestinal epithelium stays separated from an invading pathogen through an extracellular matrix in which sIgA, pIgR, and E-cadherin are colocalized. Future mucosal vaccination strategies to control E. faecium or other opportunistic pathogens may prevent multidrug-resistant infections, hospital transmission, and outbreaks. Infections with antibiotic-resistant enterococci are an emerging worldwide problem because enterococci are resistant to most of the antibiotics used in hospitals. During antibiotic treatment, the normal bacteria are replaced by resistant enterococci within the gut, from which they can spread and cause infections. We studied antibiotic-mediated intestinal proliferation of multidrug-resistant Enterococcus faecium and the effects on intestinal architecture. We demonstrated that antibiotics allow proliferation of E. faecium in the gut, alter the mucus-associated gut bacterial layer, and reduce the colon wall, mucus thickness, and amount of Muc-2 protein. E. faecium is agglutinated in the intestine in a matrix consisting of host molecules. We hypothesize that this matrix maintains a segregation of E. faecium from the epithelium. Understanding the processes that occur in the gut during antibiotic treatment may provide clues for future mucosal vaccination strategies to control E. faecium or other multidrug-resistant opportunistic pathogens, thereby preventing infections, hospital transmission, and outbreaks. Copyright © 2015 Hendrickx et al.
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NASA Astrophysics Data System (ADS)
Davis, J.; Pickering, A.; Horak, H.; Boehm, A.
2008-12-01
Tanzania (TZ) has one of the highest rates of child mortality due to enteric disease in the world. NGOs and local agencies have introduced numerous technologies (e.g., chlorine tablets, borewells) to increase the quantity and quality of water in Dar es Salaam, the capital of Tanzania, in hopes of reducing morbidity and mortality of waterborne disease. The objective of the present study is to determine if providing personalized information about water quality and hand surface quality, as determined by concentrations of enterococci and E. coli, results in improved health and water quality in households. A cohort study was completed in June-September 2008 in 3 communities ranging from urban to per-urban in Dar es Salaam, Tanzania to achieve our objective. The study consisted of 4 cohorts that were visited 4 times over the 3 month study. One cohort received no information about water and hand quality until the end of the summer, while the other groups received either just information on hand surface quality, just information on water quality, and information on both hand surface and water quality after the first (baseline) household visit. We report concentrations of enterococci and E. coli in water sources (surface waters and bore wells), water stored in households, and environmental waters were children and adults swim and bathe. In addition, we report concentrations of enterococci and E. coli on hands of caregivers and children in households. Preliminary results of surveys on health and perceptions of water quality and illness from the households are provided. Ongoing work will integrate the microbiological and sociological data sets to determine if personalized information interventions resulted in changes in health, water quality in the household, or perceptions of water quality, quantity and relation to human health. Future work will analyze DNA samples from hands and water for human-specific Bacteroides bacteria which are only present in human feces. Our study has the potential to provide empirical evidence to promote large scale monitoring and education campaigns in Africa to improve health and reduce the burden of waterborne disease.
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Byappanahalli, Muruleedhara N.; Roll, Bruce M.; Fujioka, Roger S.
2012-01-01
High densities of Escherichia coli and enterococci are common in freshwaters on Oahu and other Hawaiian Islands. Soil along stream banks has long been suspected as the likely source of these bacteria; however, the extent of their occurrence and distribution in a wide range of soils remained unknown until the current investigation. Soil samples representing the seven major soil associations were collected on the island of Oahu and analyzed for fecal coliforms, E. coli, and enterococci by the most probable number method. Fecal coliforms, E. coli, and enterococci were found in most of the samples analyzed; log mean densities (MPN ± SE g soil−1) were 1.96±0.18, n=61; 1.21±0.17, n=57; and 2.99±0.12, n=62, respectively. Representative, presumptive cultures of E. coli and enterococci collected from the various soils were identified and further speciated using the API scheme; at least six species of Enterococcus, including Enterococcus faecalis and Enterococcus faecium, were identified. In mesocosm studies, E. coli and enterococci increased by 100-fold in 4 days, after mixing sewage-spiked soil (one part) with autoclaved soil (nine parts). E. coli remained metabolically active in the soil and readily responded to nutrients, as evidenced by increased dehydrogenase activity. Collectively, these findings indicate that populations of E. coli and enterococci are part of the natural soil microflora, potentially influencing the quality of nearby water bodies.
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A quantitative polymerase chain reaction (qPCR) method for the detection of entercocci fecal indicator bacteria has been shown to be generally applicable for the analysis of temperate fresh (Great Lakes) and marine coastal waters and for providing risk-based determinations of wat...
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Goodman, Eric R.; Platt, Richard; Bass, Richard; Onderdonk, Andrew B.; Yokoe, Deborah S.; Huang, Susan S.
2009-01-01
OBJECTIVES To evaluate the adequacy of discharge room cleaning and the impact of a cleaning intervention on the presence of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) on environmental surfaces in intensive care unit (ICU) rooms. DESIGN Prospective environmental study. SETTING AND SAMPLE Convenience sample of ICU rooms in an academic hospital. METHODS AND INTERVENTION The intervention consisted of (1) a change from the use of pour bottles to bucket immersion for applying disinfectant to cleaning cloths, (2) an educational campaign, and (3) feedback regarding adequacy of discharge cleaning. Cleaning of 15 surfaces was evaluated by inspecting for removal of a preapplied mark, visible only with an ultraviolet lamp (“black light”). Six surfaces were cultured for MRSA or VRE contamination. Outcomes of mark removal and culture positivity were evaluated by χ2 testing and generalized linear mixed models, clustering by room. RESULTS The black-light mark was removed from 44% of surfaces at baseline, compared with 71% during the intervention (P <.001). The intervention increased the likelihood of removal of black-light marks after discharge cleaning (odds ratio, 4.4; P < .001), controlling for ICU type (medical vs surgical) and type of surface. The intervention reduced the likelihood of an environmental culture positive for MRSA or VRE (proportion of cultures positive, 45% at baseline vs 27% during the intervention; adjusted odds ratio, 0.4; P = .02). Broad, flat surfaces were more likely to be cleaned than were doorknobs and sink or toilet handles. CONCLUSIONS Increasing the volume of disinfectant applied to environmental surfaces, providing education for Environmental Services staff, and instituting feedback with a black-light marker improved cleaning and reduced the frequency of MRSA and VRE contamination. PMID:18624666
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Comparing rapid and culture indicator bacteria methods at inland lake beaches
Francy, Donna S.; Bushon, Rebecca N.; Brady, Amie M.G.; Kephart, Christopher M.
2013-01-01
A rapid method, quantitative polymerase chain reaction (qPCR), for quantifying indicator bacteria in recreational waters is desirable for public health protection. We report that replacing current Escherichia coli standards with new US Environmental Protection Agency beach action values (BAVs) for enterococci by culture or qPCR may result in more advisories being posted at inland recreational lakes. In this study, concentrations of E. coli and enterococci by culture methods were compared to concentrations of Enterococcus spp. by qPCR at 3 inland lake beaches in Ohio. The E. coli and enterococci culture results were significantly related at all beaches; however, the relations between culture results and Enterococcus spp. qPCR results were not always significant and differed among beaches. All the qPCR results exceeded the new BAV for Enterococcus spp. by qPCR, whereas only 23.7% of culture results for E. coli and 79% of culture results for enterococci exceeded the current standard for E. coli or BAV for enterococci.
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Cui, Henglin; Yang, Kun; Pagaling, Eulyn
2013-01-01
Recent studies have reported high levels of fecal indicator enterococci in marine beach sand. This study aimed to determine the spatial and temporal variation of enterococcal abundance and to evaluate its relationships with microbial community parameters in Hawaii beach sand and water. Sampling at 23 beaches on the Island of Oahu detected higher levels of enterococci in beach foreshore sand than in beach water on a mass unit basis. Subsequent 8-week consecutive samplings at two selected beaches (Waialae and Kualoa) consistently detected significantly higher levels of enterococci in backshore sand than in foreshore/nearshore sand and beach water. Comparison between the abundance of enterococci and the microbial communities showed that enterococci correlated significantly with total Vibrio in all beach zones but less significantly with total bacterial density and Escherichia coli. Samples from the different zones of Waialae beach were sequenced by 16S rRNA gene pyrosequencing to determine the microbial community structure and diversity. The backshore sand had a significantly more diverse community and contained different major bacterial populations than the other beach zones, which corresponded to the spatial distribution pattern of enterococcal abundance. Taken together, multiple lines of evidence support the possibility of enterococci as autochthonous members of the microbial community in Hawaii beach sand. PMID:23563940
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Brooks, John P; Adeli, Ardeshir; Read, John J; McLaughlin, Michael R
2009-01-01
Runoff water following a rain event is one possible source of environmental contamination after a manure application. This greenhouse study used a rainfall simulator to determine bacterial-associated runoff from troughs of common bermudagrass [Cynodon dactylon (L.) Pers.] that were treated with P-based, N-based, and N plus lime rates of poultry (Gallus gallus) litter, recommended inorganic fertilizer, and control. Total heterotrophic plate count (HPC) bacteria, total and thermotolerant coliforms, enterococci, staphylococci, Clostridium perfringens, Salmonella, and Campylobacter, as well as antibiotic resistance profiles for the staphylococci and enterococci isolates were all monitored in runoff waters. Analysis following five rainfall events indicated that staphylococci, enterococci, and clostridia levels were related to manure application rate. Runoff release of staphylococci, enterococci, and C. perfringens were approximately 3 to 6 log10 greater in litter vs. control treatment. In addition, traditional indicators such as thermotolerant and total coliforms performed poorly as fecal indicators. Some isolated enterococci demonstrated increased antibiotic resistance to polymixin b and/or select aminoglyocosides, while many staphylococci were susceptible to most antimicrobials tested. Results indicated poultry litter application can lead to microbial runoff following simulated rain events. Future studies should focus on the use of staphylococci, enterococci, and C. perfringens as indicators.
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Whitman, Richard L.; Shively, Dawn A.; Pawlik, Heather; Nevers, Meredith B.; Byappanahalli, Muruleedhara N.
2003-01-01
Each summer, the nuisance green alga Cladophora (mostly Cladophora glomerata) amasses along Lake Michigan beaches, creating nearshore anoxia and unsightly, malodorous mats that can attract problem animals and detract from visitor enjoyment. Traditionally, elevated counts of Escherichia coli are presumed to indicate the presence of sewage, mostly derived from nearby point sources. The relationship between fecal indicator bacteria and Cladophora remains essentially unstudied. This investigation describes the local and regional density of Escherichia coli and enterococci in Cladophora mats along beaches in the four states (Wisconsin, Illinois, Indiana, and Michigan) bordering Lake Michigan. Samples of Cladophora strands collected from 10 beaches (n = 41) were assayed for concentrations of E. coli and enterococci during the summer of 2002. Both E. coli and enterococci were ubiquitous (up to 97% occurrence), with overall log mean densities (± standard errors) of 5.3 (± 4.8) and 4.8 (± 4.5) per g (dry weight). E. coli and enterococci were strongly correlated in southern Lake Michigan beaches (P < 0.001, R2 = 0.73, n = 17) but not in northern beaches (P = 0.892, n = 16). Both E. coli and enterococci survived for over 6 months in sun-dried Cladophora mats stored at 4°C; the residual bacteria in the dried alga readily grew upon rehydration. These findings suggest that Cladophora amassing along the beaches of Lake Michigan may be an important environmental source of indicator bacteria and call into question the reliability of E. coli and enterococci as indicators of water quality for freshwater recreational beaches. PMID:12902262
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Whitman, Richard L; Shively, Dawn A; Pawlik, Heather; Nevers, Meredith B; Byappanahalli, Muruleedhara N
2003-08-01
Each summer, the nuisance green alga Cladophora (mostly Cladophora glomerata) amasses along Lake Michigan beaches, creating nearshore anoxia and unsightly, malodorous mats that can attract problem animals and detract from visitor enjoyment. Traditionally, elevated counts of Escherichia coli are presumed to indicate the presence of sewage, mostly derived from nearby point sources. The relationship between fecal indicator bacteria and Cladophora remains essentially unstudied. This investigation describes the local and regional density of Escherichia coli and enterococci in Cladophora mats along beaches in the four states (Wisconsin, Illinois, Indiana, and Michigan) bordering Lake Michigan. Samples of Cladophora strands collected from 10 beaches (n = 41) were assayed for concentrations of E. coli and enterococci during the summer of 2002. Both E. coli and enterococci were ubiquitous (up to 97% occurrence), with overall log mean densities (+/- standard errors) of 5.3 (+/- 4.8) and 4.8 (+/- 4.5) per g (dry weight). E. coli and enterococci were strongly correlated in southern Lake Michigan beaches (P < 0.001, R(2) = 0.73, n = 17) but not in northern beaches (P = 0.892, n = 16). Both E. coli and enterococci survived for over 6 months in sun-dried Cladophora mats stored at 4 degrees C; the residual bacteria in the dried alga readily grew upon rehydration. These findings suggest that Cladophora amassing along the beaches of Lake Michigan may be an important environmental source of indicator bacteria and call into question the reliability of E. coli and enterococci as indicators of water quality for freshwater recreational beaches.
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Whitman, Richard L.; Shively, Dawn A.; Pawlik, Heather; Nevers, Meredith B.; Byappanahalli, Muruleedhara N.
2003-01-01
Each summer, the nuisance green alga Cladophora (mostly Cladophora glomerata) amasses along Lake Michigan beaches, creating nearshore anoxia and unsightly, malodorous mats that can attract problem animals and detract from visitor enjoyment. Traditionally, elevated counts of Escherichia coli are presumed to indicate the presence of sewage, mostly derived from nearby point sources. The relationship between fecal indicator bacteria and Cladophora remains essentially unstudied. This investigation describes the local and regional density of Escherichia coli and enterococci in Cladophora mats along beaches in the four states (Wisconsin, Illinois, Indiana, and Michigan) bordering Lake Michigan. Samples of Cladophora strands collected from 10 beaches (n = 41) were assayed for concentrations of E. coli and enterococci during the summer of 2002. Both E. coli and enterococci were ubiquitous (up to 97% occurrence), with overall log mean densities (± standard errors) of 5.3 (± 4.8) and 4.8 (± 4.5) per g (dry weight). E. coli and enterococci were strongly correlated in southern Lake Michigan beaches (P R2 = 0.73, n = 17) but not in northern beaches (P = 0.892, n = 16). Both E. coli and enterococci survived for over 6 months in sun-dried Cladophora mats stored at 4°C; the residual bacteria in the dried alga readily grew upon rehydration. These findings suggest that Cladophora amassing along the beaches of Lake Michigan may be an important environmental source of indicator bacteria and call into question the reliability of E. coli and enterococci as indicators of water quality for freshwater recreational beaches.
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Beukers, Alicia G.; Zaheer, Rahat; Cook, Shaun R.; Stanford, Kim; Chaves, Alexandre V.; Ward, Michael P.; McAllister, Tim A.
2015-01-01
Tylosin phosphate is a macrolide commonly administered to cattle in North America for the control of liver abscesses. This study investigated the effect of in-feed administration of tylosin phosphate to cattle at subtherapeutic levels and its subsequent withdrawal on macrolide resistance using enterococci as an indicator bacterium. Fecal samples were collected from steers that received no antibiotics and steers administered tylosin phosphate (11 ppm) in-feed for 197 days and withdrawn 28 days before slaughter. Enterococcus species isolated from fecal samples were identified through sequencing the groES-EL intergenic spacer region and subject to antimicrobial susceptibility testing, identification of resistance determinants and pulsed-field gel electrophoresis profiling. Tylosin increased (P < 0.05) the proportion of eryR and tylR enterococci within the population. Just prior to its removal, the proportion of eryR and tylR resistant enterococci began decreasing and continued to decrease after tylosin was withdrawn from the diet until there was no difference (P > 0.05) between treatments on d 225. This suggests that antibiotic withdrawal prior to slaughter contributes to a reduction in the proportion of macrolide resistant enterococci entering the food chain. Among the 504 enterococci isolates characterized, Enterococcus hirae was found to predominate (n = 431), followed by Enterococcus villorum (n = 32), Enterococcus faecium (n = 21), Enterococcus durans (n = 7), Enterococcus casseliflavus (n = 4), Enterococcus mundtii (n = 4), Enterococcus gallinarum (n = 3), Enterococcus faecalis (n = 1), and Enterococcus thailandicus (n = 1). The diversity of enterococci was greater in steers at arrival than at exit from the feedlot. Erythromycin resistant isolates harbored the erm(B) and/or msrC gene. Similar PFGE profiles of eryR E. hirae pre- and post-antibiotic treatment suggest that increased abundance of eryR enterococci after administration of tylosin phosphate reflects selection for strains that were already present within the gastrointestinal tract of cattle at arrival. PMID:26074889
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Multi-laboratory survey of qPCR enterococci analysis method performance
Quantitative polymerase chain reaction (qPCR) has become a frequently used technique for quantifying enterococci in recreational surface waters, but there are several methodological options. Here we evaluated how three method permutations, type of mastermix, sample extract dilution and use of controls in results calculation, affect method reliability among multiple laboratories with respect to sample interference. Multiple samples from each of 22 sites representing an array of habitat types were analyzed using EPA Method 1611 and 1609 reagents with full strength and five-fold diluted extracts. The presence of interference was assessed three ways: using sample processing and PCR amplifications controls; consistency of results across extract dilutions; and relative recovery of target genes from spiked enterococci in water sample compared to control matrices with acceptable recovery defined as 50 to 200%. Method 1609, which is based on an environmental mastermix, was found to be superior to Method 1611, which is based on a universal mastermix. Method 1611 had over a 40% control assay failure rate with undiluted extracts and a 6% failure rate with diluted extracts. Method 1609 failed in only 11% and 3% of undiluted and diluted extracts analyses. Use of sample processing control assay results in the delta-delta Ct method for calculating relative target gene recoveries increased the number of acceptable recovery results. Delta-delta tended to bias recoveries fr
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Mote, Beth L.; Turner, Jeffrey W.
2012-01-01
Enterococci are used to evaluate recreational-water quality and health risks in marine environments. In addition to their occurrence in feces of warm blooded animals, they are also common epiphytes. We investigated the contribution of plankton- or particle-associated enterococci in estuarine and coastal water. Seven water and size-fractionated plankton samples were collected monthly between April 2008 and January 2009 in the tidal reaches of the Skidaway River (Georgia, USA). Each size fraction, along with filtered (<30 μm) and bulk estuarine water, was processed according to U.S. Environmental Protection Agency method 1600. Presumptive enterococci were selected and species were identified using carbon substrate utilization patterns. The highest average densities occurred within the 30-, 63-, 105-, and 150-μm size fractions, which also represented the majority (>99%) of the particles within the sampled water. Particle-associated enterococci accounted for as little as 1% of enterococci in bulk water in April to as much as 95% in July. Enterococcus faecalis was the most commonly isolated species from both water and plankton and represented 31% (16/51) and 35% (6/17) of the identified Enterococcus species from water and plankton, respectively. Enterococcus casseliflavus represented 29% of the selected isolates from plankton and 16% from water. Both E. faecalis and E. casseliflavus were able to survive and grow in plankton suspensions significantly longer than in artificial seawater. Enterococcus spp. may be highly concentrated in plankton and associated particles, especially during summer and fall months. These findings could have implications for the effectiveness of enterococci as an indicator of coastal water quality, especially in particle-rich environments. PMID:22327586
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Shibata, Tomoyuki; Solo-Gabriele, Helena M; Sinigalliano, Christopher D; Gidley, Maribeth L; Plano, Lisa R W; Fleisher, Jay M; Wang, John D; Elmir, Samir M; He, Guoqing; Wright, Mary E; Abdelzaher, Amir M; Ortega, Cristina; Wanless, David; Garza, Anna C; Kish, Jonathan; Scott, Troy; Hollenbeck, Julie; Backer, Lorraine C; Fleming, Lora E
2010-11-01
The objectives of this work were to compare enterococci (ENT) measurements based on the membrane filter, ENT(MF) with alternatives that can provide faster results including alternative enterococci methods (e.g., chromogenic substrate (CS), and quantitative polymerase chain reaction (qPCR)), and results from regression models based upon environmental parameters that can be measured in real-time. ENT(MF) were also compared to source tracking markers (Staphylococcus aureus, Bacteroidales human and dog markers, and Catellicoccus gull marker) in an effort to interpret the variability of the signal. Results showed that concentrations of enterococci based upon MF (<2 to 3320 CFU/100 mL) were significantly different from the CS and qPCR methods (p < 0.01). The correlations between MF and CS (r = 0.58, p < 0.01) were stronger than between MF and qPCR (r ≤ 0.36, p < 0.01). Enterococci levels by MF, CS, and qPCR methods were positively correlated with turbidity and tidal height. Enterococci by MF and CS were also inversely correlated with solar radiation but enterococci by qPCR was not. The regression model based on environmental variables provided fair qualitative predictions of enterococci by MF in real-time, for daily geometric mean levels, but not for individual samples. Overall, ENT(MF) was not significantly correlated with source tracking markers with the exception of samples collected during one storm event. The inability of the regression model to predict ENT(MF) levels for individual samples is likely due to the different sources of ENT impacting the beach at any given time, making it particularly difficult to to predict short-term variability of ENT(MF) for environmental parameters.
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Whitman, Richard L.; Shively, Dawn A.; Pawlik, Heather; Nevers, Meredith; Byappanahalli, Muruleedhara N.
2003-01-01
Each summer, the nuisance green alga Cladophora (mostly Cladophora glomerata) amasses along Lake Michigan beaches, creating nearshore anoxia and unsightly, malodorous mats that can attract problem animals and detract from visitor enjoyment. Traditionally, elevated counts of Escherichia coli are presumed to indicate the presence of sewage, mostly derived from nearby point sources. The relationship between fecal indicator bacteria and Cladophora remains essentially unstudied. This investigation describes the local and regional density ofEscherichia coli and enterococci in Cladophora mats along beaches in the four states (Wisconsin, Illinois, Indiana, and Michigan) bordering Lake Michigan. Samples of Cladophora strands collected from 10 beaches (n = 41) were assayed for concentrations of E. coli and enterococci during the summer of 2002. Both E. coli and enterococci were ubiquitous (up to 97% occurrence), with overall log mean densities (± standard errors) of 5.3 (± 4.8) and 4.8 (± 4.5) per g (dry weight). E. coli and enterococci were strongly correlated in southern Lake Michigan beaches (P< 0.001, R2 = 0.73, n = 17) but not in northern beaches (P = 0.892, n = 16). BothE. coli and enterococci survived for over 6 months in sun-dried Cladophora mats stored at 4°C; the residual bacteria in the dried alga readily grew upon rehydration. These findings suggest that Cladophora amassing along the beaches of Lake Michigan may be an important environmental source of indicator bacteria and call into question the reliability of E. coli and enterococci as indicators of water quality for freshwater recreational beaches.
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Dada, Ayokunle Christopher; Ahmad, Asmat; Usup, Gires; Heng, Lee Yook; Hamid, Rahimi
2013-09-01
We report the first study on the occurrence of high-level aminoglycoside-resistant (HLAR) Enterococci in coastal bathing waters and beach sand in Malaysia. None of the encountered isolates were resistant to high levels of gentamicin (500 μg/mL). However, high-level resistance to kanamycin (2,000 μg/mL) was observed in 14.2 % of tested isolates, the highest proportions observed being among beach sand isolates. High-level resistance to kanamycin was higher among Enterococcus faecalis and Enterococcus faecium than Enterococcus spp. Chi-square analysis showed no significant association between responses to tested antibiotics and the species allocation or source of isolation of all tested Enterococci. The species classification of encountered Enterococci resistance to vancomycin was highest among Enterococcus spp. (5.89 %) followed by E. faecium (4.785) and least among E. faecalis. A total of 160 isolates were also tested for virulence characteristics. On the whole, caseinase production was profoundly highest (15.01 %) while the least prevalent virulence characteristic observed among tested beach Enterococci was haemolysis of rabbit blood (3.65 %). A strong association was observed between the source of isolation and responses for each of caseinase (C = 0.47, V = 0.53) and slime (C = 0.50, V = 0.58) assays. Analysis of obtained spearman's coefficient showed a strong correlation between caseinase and each of the slime production (p = 0.04), gelatinase (p = 0.0035) and haemolytic activity on horse blood (p = 0.004), respectively. Suggestively, these are the main virulent characteristics of the studied beach Enterococci. Our findings suggest that recreational beaches may contribute to the dissemination of Enterococci with HLAR and virulence characteristics.
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Rapid identification of enterococci.
Brown, L H; Peterson, E M; de la Maza, L M
1983-01-01
Enterococci were identified in 4 h with bile esculin agar and the Autobac system (General Diagnostics, Warner-Lambert Co., Morris Plains, N.J.), which was used to incubate and monitor salt broth for growth. Of 86 group D streptococci tested, 41 enterococci grew in salt broth and were bile esculin positive within 4 h; none of 45 group D nonenterococcal streptococci exhibited growth in the salt broth, and only 38 of them were bile esculin positive within 4 h. PMID:6403579
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Enterococci in the environment
Byappanahalli, Muruleedhara N.; Nevers, Meredith B.; Korajkic, Asja; Staley, Zachery R.; Harwood, Valerie J.
2012-01-01
Enterococci are common, commensal members of gut communities in mammals and birds, yet they are also opportunistic pathogens that cause millions of human and animal infections annually. Because they are shed in human and animal feces, are readily culturable, and predict human health risks from exposure to polluted recreational waters, they are used as surrogates for waterborne pathogens and as fecal indicator bacteria (FIB) in research and in water quality testing throughout the world. Evidence from several decades of research demonstrates, however, that enterococci may be present in high densities in the absence of obvious fecal sources and that environmental reservoirs of these FIB are important sources and sinks, with the potential to impact water quality. This review focuses on the distribution and microbial ecology of enterococci in environmental (secondary) habitats, including the effect of environmental stressors; an outline of their known and apparent sources, sinks, and fluxes; and an overview of the use of enterococci as FIB. Finally, the significance of emerging methodologies, such as microbial source tracking (MST) and empirical predictive models, as tools in water quality monitoring is addressed. The mounting evidence for widespread extraenteric sources and reservoirs of enterococci demonstrates the versatility of the genus Enterococcus and argues for the necessity of a better understanding of their ecology in natural environments, as well as their roles as opportunistic pathogens and indicators of human pathogens.
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Micallef, Shirley A; Goldstein, Rachel E Rosenberg; George, Ashish; Ewing, Laura; Tall, Ben D; Boyer, Marc S; Joseph, Sam W; Sapkota, Amy R
2013-12-01
Antibiotic-resistant enterococci are important opportunistic pathogens and have been recovered from retail tomatoes. However, it is unclear where and how tomatoes are contaminated along the farm-to-fork continuum. Specifically, the degree of pre-harvest contamination with enterococci is unknown. We evaluated the prevalence, diversity and antimicrobial susceptibilities of enterococci collected from tomato farms in the Mid-Atlantic United States. Tomatoes, leaves, groundwater, pond water, irrigation ditch water, and soil were sampled and tested for enterococci using standard methods. Antimicrobial susceptibility testing was performed using the Sensititre microbroth dilution system. Enterococcus faecalis isolates were characterized using amplified fragment length polymorphism to assess dispersal potential. Enterococci (n = 307) occurred in all habitats and colonization of tomatoes was common. Seven species were identified: Enterococcus casseliflavus, E. faecalis, Enterococcus gallinarum, Enterococcus faecium, Enterococcus avis, Enterococcus hirae and Enterococcus raffinosus. E. casseliflavus predominated in soil and on tomatoes and leaves, and E. faecalis predominated in pond water. On plants, distance from the ground influenced presence of enterococci. E. faecalis from samples within a farm were more closely related than those from samples between farms. Resistance to rifampicin, quinupristin/dalfopristin, ciprofloxacin and levofloxacin was prevalent. Consumption of raw tomatoes as a potential exposure risk for antibiotic-resistant Enterococcus spp. deserves further attention. Copyright © 2013 Elsevier Ltd. All rights reserved.
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Enterococci in the Environment
Byappanahalli, Muruleedhara N.; Nevers, Meredith B.; Korajkic, Asja; Staley, Zachery R.
2012-01-01
Summary: Enterococci are common, commensal members of gut communities in mammals and birds, yet they are also opportunistic pathogens that cause millions of human and animal infections annually. Because they are shed in human and animal feces, are readily culturable, and predict human health risks from exposure to polluted recreational waters, they are used as surrogates for waterborne pathogens and as fecal indicator bacteria (FIB) in research and in water quality testing throughout the world. Evidence from several decades of research demonstrates, however, that enterococci may be present in high densities in the absence of obvious fecal sources and that environmental reservoirs of these FIB are important sources and sinks, with the potential to impact water quality. This review focuses on the distribution and microbial ecology of enterococci in environmental (secondary) habitats, including the effect of environmental stressors; an outline of their known and apparent sources, sinks, and fluxes; and an overview of the use of enterococci as FIB. Finally, the significance of emerging methodologies, such as microbial source tracking (MST) and empirical predictive models, as tools in water quality monitoring is addressed. The mounting evidence for widespread extraenteric sources and reservoirs of enterococci demonstrates the versatility of the genus Enterococcus and argues for the necessity of a better understanding of their ecology in natural environments, as well as their roles as opportunistic pathogens and indicators of human pathogens. PMID:23204362
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Public Health Risks of Multiple-Drug-Resistant Enterococcus spp. in Southeast Asia
Lee, Sui Mae; Rahman, Sadequr
2015-01-01
Enterococci rank as one of the leading causes of nosocomial infections, such as urinary tract infections, surgical wound infections, and endocarditis, in humans. These infections can be hard to treat because of the rising incidence of antibiotic resistance. Enterococci inhabiting nonhuman reservoirs appear to play a critical role in the acquisition and dissemination of antibiotic resistance determinants. The spread of antibiotic resistance has become a major concern in both human and veterinary medicine, especially in Southeast Asia, where many developing countries have poor legislation and regulations to control the supply and excessive use of antimicrobials. This review addresses the occurrence of antibiotic-resistant enterococci in Association of Southeast Asian Nations countries and proposes infection control measures that should be applied to limit the spread of multiple-drug-resistant enterococci. PMID:26150452
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Moriarty, E M; Weaver, L; Sinton, L W; Gilpin, B
2012-11-01
Freshly excreted Canada goose faeces pose a public health risk as they contain pathogenic microorganisms. Accordingly, a study was carried out on the growth and survival of resident indicator bacteria (enterococci and Escherichia coli) and inoculated Campylobacter jejuni in freshly excreted faeces over summer and winter. Canada goose faeces were collected, mixed thoroughly and inoculated with 10⁸ g⁻¹ C. jejuni. The faeces were mixed again before making the Canada goose dropping. The simulated goose droppings (N = 70) were placed on pasture, and the concentrations of E. coli, enterococci and the pathogen, C. jejuni, were monitored. In summer only, the molecular marker of E. coli LacZ and the avian-associated bacteria E2 was also monitored. Results of the survival study indicated that significant growth of enterococci and E. coli occurred in summer, before concentrations decreased to less than 15% of the original concentration (day 77) for enterococci and 0.01% for E. coli. LacZ followed a similar pattern to E. coli, while the E2 marker dropped to below 0.1% of the original concentration within 4 days. In winter, enterococci grew slightly, while no growth of E. coli occurred. In both summer and winter, C. jejuni was rapidly inactivated. This research highlights the ability of bacterial indicators to replicate and survive in the environment when harboured by avian faeces, and the limited risk aged Canada goose faeces pose as an environmental source of Campylobacter spp. © 2012 Blackwell Verlag GmbH.
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A critical evaluation of a flow cytometer used for detecting enterococci in recreational waters.
King, Dawn N; Brenner, Kristen P; Rodgers, Mark R
2007-06-01
The current U. S. Environmental Protection Agency-approved method for enterococci (Method 1600) in recreational water is a membrane filter (MF) method that takes 24 hours to obtain results. If the recreational water is not in compliance with the standard, the risk of exposure to enteric pathogens may occur before the water is identified as hazardous. Because flow cytometry combined with specific fluorescent antibodies has the potential to be used as a rapid detection method for microorganisms, this technology was evaluated as a rapid, same-day method to detect enterococci in bathing beach waters. The flow cytometer chosen for this study was a laser microbial detection system designed to detect labeled antibodies. A comparison of MF counts with flow cytometry counts of enterococci in phosphate buffer and sterile-filtered recreational water showed good agreement between the two methods. However, when flow cytometry was used, the counts were several orders of magnitude higher than the MF counts with no correlation to Enterococcus spike concentrations. The unspiked sample controls frequently had higher counts than the samples spiked with enterococci. Particles within the spiked water samples were probably counted as target cells by the flow cytometer because of autofluorescence or non-specific adsorption of antibody and carryover to subsequent samples. For these reasons, this technology may not be suitable for enterococci detection in recreational waters. Improvements in research and instrument design that will eliminate high background and carryover may make this a viable technology in the
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Observations of transport of bacterial-like microspheres through beach sand
NASA Astrophysics Data System (ADS)
Gast, Rebecca J.; Elgar, Steve; Raubenheimer, Britt
2015-04-01
Often, there is an order of magnitude more fecal indicator bacteria (enterococci) in beach sand than in nearby water. Consequently, sand is considered a reservoir for these bacteria, potentially contributing to poor water quality, and raising questions regarding the human health risks associated with sand exposure. An integral aspect of the distribution and persistence of sand-associated enterococci is the transport of bacteria introduced into the beach environment. Here, plastic microspheres are used as a proxy to examine the wave-induced movement of bacterial-like particles through sand on an ocean beach. Laboratory tests suggest microspheres and bacteria move similarly through sand columns, and have qualitatively similar short-term adsorption-to-sand behavior. Microspheres buried ~0.05 m below the sand surface on an ocean beach moved rapidly [O(10-3) m/s] away from their initial location, both vertically into the ground water below the sand and horizontally seaward within the sediment matrix in response to waves running up the beach face and percolating through the sand.
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Membrane Filter Technique for Enumeration of Enterococci in Marine Waters
Levin, M. A.; Fischer, J. R.; Cabelli, V. J.
1975-01-01
A membrane filter procedure is described for the enumeration of enterococci in marine waters. The procedure utilizes a highly selective and somewhat differential primary isolation medium followed by an in situ substrate test for identifying colonies of those organisms capable of hydrolyzing esculin. The procedure (mE) was evaluated with known streptococci strains and field samples with regard to its accuracy, sensitivity, selectivity, specificity, precision, and comparability to existing methods. Essentially quantitative recovery was obtained with seawater-stressed cells of Streptococcus faecalis and S. faccium. Neither S. bovis, S. equinus, S. mitis, nor S. salivarius grew on the medium. The selectivity of the medium was such that a 10,000-fold reduction in background organisms was obtained relative to a medium which contained no inhibitors and was incubated at 35 C. About 90% of those typical colonies designated as enterococci confirmed as such and about 12% of the colonies not so designated were, in fact, identified as enterococci. Plate to plate variability across samples approximated that expected by chance alone. Verified recoveries of enterococci from natural samples by the mE procedure, on the average, exceeded those by the KF method by one order of magnitude. PMID:807165
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Piggot, Alan M.; Johnson, Sara; Phillips, Matthew C.; Solo-Gabriele, Helena M.
2012-01-01
Enterococci, recommended at the U.S. federal level for monitoring water quality at marine recreational beaches, have been found to reside and grow within beach sands. However, the environmental and ecological factors affecting enterococcal persistence remain poorly understood, making it difficult to determine levels of fecal pollution and assess human health risks. Here we document the presence of enterococci associated with beach sediment biofilms at eight south Florida recreational beaches. Enterococcal levels were highest in supratidal sands, where they displayed a nonlinear, unimodal relationship with extracellular polymeric secretions (EPS), the primary component of biofilms. Enterococcal levels peaked at intermediate levels of EPS, suggesting that biofilms may promote the survival of enterococci but also inhibit enterococci as the biofilm develops within beach sands. Analysis of bacterial community profiles determined by terminal restriction fragment length polymorphisms showed the bacterial communities of supratidal sediments to be significantly different from intertidal and subtidal communities; however, no differences were observed in bacterial community compositions associated with different EPS concentrations. Our results suggest that supratidal sands are a microbiologically unique environment favorable for the incorporation and persistence of enterococci within beach sediment biofilms. PMID:22706061
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Elal Mus, Tulay; Cetinkaya, Figen; Cibik, Recep; Soyutemiz, Gul Ece; Simsek, Husniye; Coplu, Nilay
2017-12-01
In this study, the presence of genes responsible for the pathogenicity and antibiotic resistance profile of enterococci isolated from various foodstuffs of animal origin was investigated. The percentage prevalence of enterococci was 54.1% (203/375) and the average count was found to be 3.81 log cfu/ml-g. Species-specific primers revealed Enterococcus faecalis as the predominant species carrying one or more virulence-associated traits of efa, gelE, ace, esp and agg genetic markers. Only one E. faecium isolate (from milk) was positive for the esp gene. Regarding antibiotic resistance, the highest frequency of resistance was observed for tetracycline (21.7%), followed by quinupristin/dalfopristin (13.3%), ciprofloxacin (2.0%), penicillin (2.0%), linezolid (1.0%), ampicillin (1.0%), streptomycin (1.0%), and gentamicin (0.5%). Enterococcus faecalis showed a higher prevalence of antibiotic resistance than other enterococci. The percentage of multidrug resistance among the isolates was 3.4%. Twenty-nine E. faecalis isolates (26.6%) carrying one of the virulence-associated traits were at the same time resistant to at least one antibiotic. Our results show that foods of animal origin, including ready-to-eat products, may be reservoirs of antibiotic-resistant and potentially virulent enterococci.
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Survival of enterococci during hospital laundry processing.
Orr, K E; Holliday, M G; Jones, A L; Robson, I; Perry, J D
2002-02-01
Much remains to be elucidated about the epidemiology of nosocomial enterococcal infections. Enterococci are, however, known to be relatively thermotolerant, and several studies have shown that under laboratory conditions many strains are able to survive the time/temperature combinations of the UK Department of Health recommendations for the decontamination of used linen (HSG(95)18). We therefore wished to investigate the efficacy of decontamination of enterococci from hospital linen in working hospital laundries. The thermotolerance of 40 strains of Enterococcus faecalis and Enterococcus faecium was first determined. Reduction by a factor of greater than 10(5) was achieved in only two of 40 strains after 3 min at 71 degrees C or 10 min at 65 degrees C, the time/temperature combinations specified by the Department of Health for the disinfection of used linen. During experimental challenge of 10 working hospital laundries, however, we demonstrated successful decontamination of laundry artificially contaminated with enterococci. This was shown to take place during the washing stage. Our study suggests that, despite the relative thermotolerance of enterococci, the time/temperature combinations specified in HSG(95)18 should be adequate for their decontamination in hospital laundries. Copyright 2002 The Hospital Infection Society.
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Byappanahalli, M.; Fujioka, R.
2004-01-01
The soil environment in Hawaii is generally characterised as sub-optimal but permissive to support the in situ growth of E. coli and enterococci. However, soil desiccation and competition for nutrients by major indigenous soil microflora have been identified as potential factors that could limit a rapid and continual growth of faecal indicator bacteria in this soil environment. Despite these limitations, the genetic capacities of E. coli and enterococci are robust enough to enable these bacteria to become established as minor populations of Hawaii's soil microflora. Although the concentrations of E. coli and enterococci may have represented a fraction of the total soil microbiota, their presence in this habitat was very significant, for two important reasons: (a) soil was a major environmental source of E. coli and enterococci, and (b) the elevated counts of these bacteria in streams that routinely exceeded the EPA standards were due to run-off from soil. As a result, E. coli and enterococci were inadequate indicators to measure the degree of faecal contamination and potential presence of sewage-borne pathogens in Hawaiian streams. ?? IWA Publishing 2004.
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2013-01-01
Background Recent studies have shown that mammalian milk represents a continuous supply of commensal bacteria, including enterococci. The objectives of this study were to evaluate the presence of enterococci in milk of different species and to screen them for several genetic and phenotypic traits of clinical significance among enterococci. Results Samples were obtained from, at least, nine porcine, canine, ovine, feline and human healthy hosts. Enterococci could be isolated, at a concentration of 1.00 × 102 -1.16 × 103 CFU/ml, from all the porcine samples and, also from 85, 50, 25 and 25% of the human, canine, feline and ovine ones, respectively. They were identified as Enterococcus faecalis, Enterococcus faecium, Enterococcus hirae, Enterococcus casseliflavus and Enterococcus durans. Among the 120 initial enterococcal isolates, 36 were selected on the basis of their different PFGE profiles and further characterized. MLST analysis revealed a wide diversity of STs among the E. faecalis and E. faecium strains, including some frequently associated to hospital infections and novel STs. All the E. faecalis strains possessed some of the potential virulence determinants (cad, ccf, cob, cpd, efaAfs, agg2, gelE, cylA, espfs) assayed while the E. faecium ones only harboured the efaAfm gene. All the tested strains were susceptible to tigecycline, linezolid and vancomycin, and produced tyramine. Their susceptibility to the rest of the antimicrobials and their ability to produce other biogenic amines varied depending on the strain. Enterococci strains isolated from porcine samples showed the widest spectrum of antibiotic resistance. Conclusions Enterococci isolated from milk of different mammals showed a great genetic diversity. The wide distribution of virulence genes and/or antibiotic resistance among the E. faecalis and E. faecium isolates indicates that they can constitute a reservoir of such traits and a risk to animal and human health. PMID:24325647
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Ghosh, Anuradha; Borst, Luke; Stauffer, Stephen H.; Suyemoto, Mitsu; Moisan, Peter; Zurek, Ludek
2013-01-01
Approximately 15% of foster kittens die before 8 weeks of age, with most of these kittens demonstrating clinical signs or postmortem evidence of enteritis. While a specific cause of enteritis is not determined in most cases, these kittens are often empirically administered probiotics that contain enterococci. The enterococci are members of the commensal intestinal microbiota but also can function as opportunistic pathogens. Given the complicated role of enterococci in health and disease, it would be valuable to better understand what constitutes a “healthy” enterococcal community in these kittens and how this microbiota is impacted by severe illness. In this study, we characterized the ileum mucosa-associated enterococcal community of 50 apparently healthy and 50 terminally ill foster kittens. In healthy kittens, Enterococcus hirae was the most common species of ileum mucosa-associated enterococci and was often observed to adhere extensively to the small intestinal epithelium. These E. hirae isolates generally lacked virulence traits. In contrast, non-E. hirae enterococci, notably Enterococcus faecalis, were more commonly isolated from the ileum mucosa of kittens with terminal illness. Isolates of E. faecalis had numerous virulence traits and multiple antimicrobial resistances. Moreover, the attachment of Escherichia coli to the intestinal epithelium was significantly associated with terminal illness and was not observed in any kitten with adherent E. hirae. These findings identify a significant difference in the species of enterococci cultured from the ileum mucosa of kittens with terminal illness compared to the species cultured from healthy kittens. In contrast to prior case studies that associated enteroadherent E. hirae with diarrhea in young animals, these controlled studies identified E. hirae as more often isolated from healthy kittens and adherence of E. hirae as more common and extensive in healthy kittens than in sick kittens. PMID:23966487
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FACTORS INFLUENCING LIGHT-INDUCED MORTALITY OF ENTEROCOCCI IN SEDIMENT SUSPENSIONS
Contamination of recreational waters by pathogenic microorganisms occurs through complex, poorly understood interactions involving variable microbial sources, hydrodynamic transport, arid microbial fate processes. Fecal indicator bacteria such as enterococci have been used to ass...
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Detection of vancomycin resistances in enterococci within 3 1/2 hours
NASA Astrophysics Data System (ADS)
Schröder, U. -Ch.; Beleites, C.; Assmann, C.; Glaser, U.; Hübner, U.; Pfister, W.; Fritzsche, W.; Popp, J.; Neugebauer, U.
2015-02-01
Vancomycin resistant enterococci (VRE) constitute a challenging problem in health care institutions worldwide. Novel methods to rapidly identify resistances are highly required to ensure an early start of tailored therapy and to prevent further spread of the bacteria. Here, a spectroscopy-based rapid test is presented that reveals resistances of enterococci towards vancomycin within 3.5 hours. Without any specific knowledge on the strain, VRE can be recognized with high accuracy in two different enterococci species. By means of dielectrophoresis, bacteria are directly captured from dilute suspensions, making sample preparation very easy. Raman spectroscopic analysis of the trapped bacteria over a time span of two hours in absence and presence of antibiotics reveals characteristic differences in the molecular response of sensitive as well as resistant Enterococcus faecalis and Enterococcus faecium. Furthermore, the spectroscopic fingerprints provide an indication on the mechanisms of induced resistance in VRE.
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Potential of houseflies to contaminate ready-to-eat food with antibiotic-resistant enterococci.
Macovei, Lilia; Miles, Brett; Zurek, Ludek
2008-02-01
It was shown previously that houseflies in fast-food restaurants commonly carry antibiotic-resistant and potentially virulent enterococci. In this study, the potential of field-collected houseflies to contaminate ready-to-eat (RTE) food with enterococci was assessed by laboratory bioassays. Houseflies were collected with a sweep net in a cattle feedlot and exposed in groups of 5, 10, 20, and 40 to a beef patty (from an RTE hamburger) for 0.5, 1.0, 3.0, and 24 h. The exposure of RTE food to flies resulted in 100% contamination with enterococci in all bioassays, regardless of the number of houseflies and the length of exposure time. In addition, with the increasing number of houseflies as well as with the increasing time exposure, the concentration of enterococci in RTE food increased. Even a short time exposure (0.5 h) resulted in food contamination, ranging from 3.1 x 10(3) CFU/g (5 houseflies) to 8.4 x 10(4) CFU/g (40 houseflies). The analysis of 23 randomly selected enterococcal isolates from RTE food after the fly exposure revealed a single species, Enterococcus faecalis. In contrast, four Enterococcus species, including E. faecalis (57.1%), E. gallinarum (19.1%), E. hirae (14.3%), and E. faecium (9.5%), represented 21 randomly selected and identified isolates from houseflies. Phenotypic screening showed that E. faecalis isolates from RTE food were resistant to ciprofloxacin (17.4%), tetracycline (13.0%), erythromycin (13.0%), and chloramphenicol (4.3%). This study demonstrates a great potential of houseflies from a cattle feedlot to contaminate RTE food with enterococci in a short time.
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OCCURRENCE OF HIGH-LEVEL AMINOGLYCOSIDE RESISTANCE IN ENVIRONMENTAL ISOLATES OF ENTEROCOCCI
High-level resistance fo aminoglycosides was observed in environmental isolates of enterococci. Various aquatic habitats, including agricultural runoff, creeks, rivers, wastewater, and wells, were analyzed. Strains of Enterococcus faecalis, e.faecium, E. gallinarum, and other Ent...
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Enterococci in the Environment
Enterococci are common, commensal members of gut communities in mammals and birds, yet they are also opportunistic pathogens that cause millions of human and animal infections annually. Because they are shed in human and animal feces, are readily culturable, and predict human hea...
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Chuard, C.; Reller, L. B.
1998-01-01
The bile-esculin test is used to differentiate enterococci and group D streptococci from non-group D viridans group streptococci. The effects on test performance of the concentration of bile salts, inoculum, and duration of incubation were examined with 110 strains of enterococci, 30 strains of Streptococcus bovis, and 110 strains of non-group D viridans group streptococci. Optimal sensitivity (>99%) and specificity (97%) of the bile-esculin test can be obtained with a bile concentration of 40%, a standardized inoculum of 106 CFU, and incubation for 24 h. PMID:9542954
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Chuard, C; Reller, L B
1998-04-01
The bile-esculin test is used to differentiate enterococci and group D streptococci from non-group D viridans group streptococci. The effects on test performance of the concentration of bile salts, inoculum, and duration of incubation were examined with 110 strains of enterococci, 30 strains of Streptococcus bovis, and 110 strains of non-group D viridans group streptococci. Optimal sensitivity (> 99%) and specificity (97%) of the bile-esculin test can be obtained with a bile concentration of 40%, a standardized inoculum of 10(6) CFU, and incubation for 24 h.
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[Susceptibility of enterococci to natural and synthetic iron chelators].
Lisiecki, Paweł; Mikucki, Jerzy
2002-01-01
A total of 79 strains of enterococci belonging to 10 species were tested for susceptibility to natural and synthetic iron chelators. All strains produced siderophores. These enterococci were susceptible to three synthetic iron chelators only: 8-hydroxyquinoline, disodium versenate (EDTA) and o-phenanthroline. They were resistant to all other synthetic chelators: ethylenediamine-di(o-hydroxyphenylacetic acid) (EDDHA), nitrilotriacetate, 2,2'-bipiridyl, salicylic acid, 8-hydroxy-5-sulphonic acid and to all natural chelators: ovotransferrine, human apotransferrine, horse apoferritine, desferrioxamine B, ferrichrome and rhodotorulic acid. The relations between susceptibility/resistance, iron assimilation and structure and stability constants of iron chelators were discussed.
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Chan, Yean Yean; Abd Nasir, Mohd Hafiz B; Yahaya, Mohd Azli B; Salleh, Noor Mohamad Amin B; Md Dan, Azril Deenor B; Musa, Abd Majid B; Ravichandran, M
2008-02-29
A total of 225 samples from poultry farms and the surrounding environment were screened for vancomycin-resistant enterococci (VRE) and bifunctional aminoglycoside-resistant enterococci using conventional microbiological tests and a nanoplex polymerase chain reaction (PCR) assay. Three (1.3%) of the samples were found to contain vancomycin-resistant isolates (MIC>256 microg/mL) that had a vanA genotype. The three vanA positive VRE isolates were identified as different species. Only one isolate (Enterococcus faecium F 4/13_54) was sensitive to teicoplanin (MIC<0. 12-0.35 microg/mL); the other two VRE (E. faecalis A 21_35 and E. gallinarum F 5/10_1) were resistant to teicoplanin (MIC 3.6-->16 microg/mL). The vanC genotype was observed in nine (4%) of the samples collected. High-level gentamicin-resistant (HLGR) enterococci (with MIC ranging between 100 and 500 microg/mL) were detected in 44 samples. However, only 40 of these were found to possess the aac(6')-aph(2'') gene. The overall prevalence of VRE among the samples from the poultry farms and environment was 5.3%, but the prevalence of the clinically significant vanA VRE was 1.3%, and the prevalence of bifunctional aminoglycoside-resistant enterococci was slightly higher, at 19.5%.
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Lee, Sae-Mi; Huh, Hee Jae; Song, Dong Joon; Shim, Hyang Jin; Park, Kyung Sun; Kang, Cheol-In; Ki, Chang-Seok; Lee, Nam Yong
2017-12-01
To investigate linezolid-resistance mechanisms in linezolid-nonsusceptible enterococci (LNSE) isolated from a tertiary hospital in Korea. Enterococcal isolates exhibiting linezolid MICs ≥4 mg l -1 that were isolated between December 2011 and May 2016 were investigated by PCR and sequencing for mutations in 23S rRNA or ribosomal proteins (L3, L4 and L22) and for the presence of cfr, cfr(B) and optrA genes.Results/Key findings. Among 135 LNSE (87 Enterococcus faecium and 48 Enterococcus faecalis isolates), 39.1 % (34/87) of E. faecium and 18.8 % (9/48) of E. faecalis isolates were linezolid-resistant. The optrA carriage was the dominant mechanism in E. faecalis: 13 isolates, including 10 E. faecalis [70 % (7/10) linezolid-resistant and 30 % (3/10) linezolid-intermediate] and three E. faecium [33.3 % (1/3) linezolid-resistant and 66.7 % (2/3) linezolid-intermediate], contained the optrA gene. G2576T mutations in the 23S rRNA gene were detected only in E. faecium [14 isolates; 71.4 % (10/14) linezolid-resistant and 28.6 % (4/14) linezolid-intermediate]. One linezolid-intermediate E. faecium harboured a L22 protein alteration (Ser77Thr). No isolates contained cfr or cfr(B) genes and any L3 or L4 protein alterations. No genetic mechanism of resistance was identified for 67.6 % (23/34) of linezolid-resistant E. faecium. A low rate of 23S rRNA mutations and the absence of known linezolid-resistance mechanisms in the majority of E. faecium isolates suggest regional differences in the mechanisms of linezolid resistance and the possibility of additional mechanisms.
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Abele-Horn, Marianne; Hommers, Leif; Trabold, René; Frosch, Matthias
2006-01-01
We evaluated the ability of the new VITEK 2 version 4.01 software to identify and detect glycopeptide-resistant enterococci compared to that of the reference broth microdilution method and to classify them into the vanA, vanB, vanC1, and vanC2 genotypes. Moreover, the accuracy of antimicrobial susceptibility testing with agents with improved potencies against glycopeptide-resistant enterococci was determined. A total of 121 enterococci were investigated. The new VITEK 2 software was able to identify 114 (94.2%) enterococcal strains correctly to the species level and to classify 119 (98.3%) enterococci correctly to the glycopeptide resistance genotype level. One Enterococcus casseliflavus strain and six Enterococcus faecium vanA strains with low-level resistance to vancomycin were identified with low discrimination, requiring additional tests. One of the vanA strains was misclassified as the vanB type, and one glycopeptide-susceptible E. facium wild type was misclassified as the vanA type. The overall essential agreements for antimicrobial susceptibility testing results were 94.2% for vancomycin, 95.9% for teicoplanin, 100% for quinupristin-dalfopristin and moxifloxacin, and 97.5% for linezolid. The rates of minor errors were 9% for teicoplanin and 5% for the other antibiotic agents. The identification and susceptibility data were produced within 4 h to 6 h 30 min and 8 h 15 min to 12 h 15 min. In conclusion, use of VITEK 2 version 4.01 software appears to be a reliable method for the identification and detection of glycopeptide-resistant enterococci as well as an improvement over the use of the former VITEK 2 database. However, a significant reduction in the detection time would be desirable. PMID:16390951
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Ekwanzala, Mutshiene Deogratias; Abia, Akebe Luther King; Ubomba-Jaswa, Eunice; Keshri, Jitendra; Momba, Ndombo Benteke Maggy
2017-12-01
To date, the microbiological quality of river sediments and its impact on water resources are not included in the water quality monitoring assessment. Therefore, the aim of this study was to establish genetic relatedness between faecal coliforms and enterococci isolated from the river water and riverbed sediments of Apies River to better understand the genetic similarity of microorganisms between the sediment and water phases. Indicator bacteria were subjected to a molecular study, which consisted of PCR amplification and sequence analysis of the 16S rRNA and 23S rRNA gene using specific primers for faecal coliforms and enterococci, respectively. Results revealed that the Apies River had high faecal pollution levels with enterococci showing low to moderate correlation coefficient (r 2 values ranged from 0.2605 to 0.7499) compared to the faecal coliforms which showed zero to low correlation (r 2 values ranged from 0.0027 to 0.1407) indicating that enterococci may be better indicator than faecal coliforms for detecting faecal contamination in riverbed sediments. The phylogenetic tree of faecal coliforms revealed a 98% homology among their nucleotide sequences confirming the close genetic relatedness between river water and riverbed sediment isolates. The phylogenetic tree of the enterococci showed that Enterococcus faecalis and Enterococcus faecium are the predominant species found in both river water and riverbed sediments with bootstrap values of ≥99%. A high degree of genetic relatedness between sediment and water isolates indicated a possible common ancestry and transmission pathway. We recommend the microbial monitoring of riverbed sediments as it harbours more diverse microbial community and once resuspended may cause health and environmental problems.
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Whitman, Richard L; Byers, Stacey E; Shively, Dawn A; Ferguson, Donna M; Byappanahalli, Muruleedhara
2005-12-01
Sarracenia purpurea L., a carnivorous bog plant (also known as the pitcher plant), represents an excellent model of a well-defined, self-contained ecosystem; the individual pitchers of the plant serve as a microhabitat for a variety of micro- and macro-organisms. Previously, fecal indicator bacteria (Escherichia coli and enterococci) were shown as incidental contaminants in pitcher fluid; however, whether their occurrence in pitcher fluid is incidental or common has not been established. The purpose of this study was to investigate the occurrence, distribution, and growth potential of E. coli and enterococci in pitcher plant fluid from a protected bog in northwest Indiana. Escherichia coli and enterococci were recovered in pitcher fluids (n=43 plants), with mean densities (log CFU mL-1) of 1.28+/-0.23 and 1.97+/-0.27, respectively. In vitro experiments showed that E. coli growth in fluid not containing insects or indigenous organisms was directly proportional to the fluid concentration (growth was 10-fold in 24 h in 100% fluid); however, in the presence of other indigenous organisms, E. coli and enterococci were only sustained for 5 days at 26 degrees C. Pulsed-field gel electrophoresis (PFGE) analysis showed that the plant Enterococcus faecalis isolates were genetically distinct from the human isolates; identical PFGE patterns were observed among plant isolates that fell into one of six clonal groups. These findings suggest that (i) E. coli and enterococci occurrence in pitcher plants is rather common in the bog studied, although their originating source is unclear, and (ii) the pitcher fluid contains adequate nutrients, especially carbon and energy sources, to promote the growth of indicator bacteria; however, under natural conditions, the biotic factors (e.g., competition for nutrients) may restrict their growth.
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Whitman, Richard L.; Byers, Stacey E.; Shively, Dawn A.; Ferguson, Donna M.; Byappanahalli, Muruleedhara N.
2005-01-01
Sarracenia purpurea L., a carnivorous bog plant (also known as the pitcher plant), represents an excellent model of a well-defined, self-contained ecosystem; the individual pitchers of the plant serve as a microhabitat for a variety of micro- and macro-organisms. Previously, fecal indicator bacteria (Escherichia coli and enterococci) were shown as incidental contaminants in pitcher fluid; however, whether their occurrence in pitcher fluid is incidental or common has not been established. The purpose of this study was to investigate the occurrence, distribution, and growth potential of E. coli and enterococci in pitcher plant fluid from a protected bog in northwest Indiana. Escherichia coli and enterococci were recovered in pitcher fluids (n = 43 plants), with mean densities (log CFU mL-1) of 1.28 ± 0.23 and 1.97 ± 0.27, respectively. In vitro experiments showed that E. coli growth in fluid not containing insects or indigenous organisms was directly proportional to the fluid concentration (growth was 10-fold in 24 h in 100% fluid); however, in the presence of other indigenous organisms, E. coli and enterococci were only sustained for 5 days at 26 °C. Pulsed-field gel electrophoresis (PFGE) analysis showed that the plant Enterococcus faecalis isolates were genetically distinct from the human isolates; identical PFGE patterns were observed among plant isolates that fell into one of six clonal groups. These findings suggest that (i) E. coli and enterococci occurrence in pitcher plants is rather common in the bog studied, although their originating source is unclear, and (ii) the pitcher fluid contains adequate nutrients, especially carbon and energy sources, to promote the growth of indicator bacteria; however, under natural conditions, the biotic factors (e.g., competition for nutrients) may restrict their growth.
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López, María; Kadlec, Kristina; Schwarz, Stefan; Torres, Carmen
2012-02-01
The trimethoprim resistance gene dfrK has been recently described in Staphylococcus aureus, but so far has not been found in other bacteria. A total of 166 enterococci of different species (E. faecium, E. faecalis, E. hirae, E. durans, E. gallinarum, and E. casseliflavus) and origins (food, clinical diseases in humans, healthy humans or animals, and sewage) were studied for their susceptibility to trimethoprim as determined by agar dilution (European Committee on Antimicrobial Susceptibility Testing) and the presence of (a) the dfrK gene and its genetic environment and (b) other dfr genes. The dfrK gene was detected in 49% of the enterococci (64% and 42% of isolates with minimum inhibitory concentrations of ≥2 mg/L or ≤1 mg/L, respectively). The tet(L)-dfrK linkage was detected in 21% of dfrK-positive enterococci. The chromosomal location of the dfrK gene was identified in one E. faecium isolate in which the dfrK was not linked to tet(L) gene but was part of a Tn559 element, which was integrated in the chromosomal radC gene. This Tn559 element was also found in 14 additional isolates. All combinations of dfr genes were detected among the isolates tested (dfrK, dfrG, dfrF, dfrK+dfrG, dfrK+dfrF, dfrF+dfrG, and dfrF+dfrG+dfrK). The gene dfrK gene was found together with other dfr genes in 58% of the tested enterococci. This study suggested an exchange of the trimethoprim resistance gene dfrK between enterococci and staphylococci, as previously observed for the trimethoprim resistance gene dfrG.
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OCCURRENCE OF VANCOMYCIN RESISTANT ENTEROCOCCI IN ANIMAL FECES
A survey was conducted to determine the occurrence of vancomycin resistant Enterococci (VRE) in animal and human fecal samples. A selective agar mEI, and mEI supplemented with 4 micrograms/ml vancomycin was used in a membrane filtration procedure to determine quantitative levels ...
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Differential decay of Enterococci and Escherichia coli originating from two fecal pollution sources
Using in situ subtropical aquatic mesocosms, fecal source (cattle manure versus sewage) was shown to be the most important contributor to differential loss in viability of fecal indicator bacteria (FIB), specifically enterococci in freshwater and Escherichia coli in marine habita...
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Jin, Guang; Jeng, Huei-Wang; Bradford, Henry; Englande, A J
2004-01-01
Escherichia coli (E. coli), enterococci, and fecal coliform data were collected and compared as potential indicators for swimmablility assessment of a brackish waterbody (Lake Pontchartrain, Louisiana). These indicators were measured during lake background conditions, in stormwater runoff (before dilution with lake water), and in the outfall plume within the lake following storm events. Microbial indicator titers associated with suspended particles and lake-bottom sediments were also investigated. Overall reduction rate constants for fecal coliform, E. coli, and enterococci in lake water and sediment were measured and reported. Attachment of microbial indicators to suspended matter and subsequent sedimentation appeared to be a significant fate mechanism. A slower reduction rate of indicator organisms in sediment further suggested that bottom sediment may act as a reservoir for prolonging indicator organism survival and added concern of recontamination of overlaying waters due to potential solids resuspension. Results indicated that enterococci might be a more stable indicator than E. coli and fecal coliform and, consequently, a more conservative indicator under brackish water conditions.
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Ben Said, Leila; Klibi, Naouel; Dziri, Raoudha; Borgo, Francesca; Boudabous, Abdellatif; Ben Slama, Karim; Torres, Carmen
2016-03-30
The objective of this study was to determine the species, clonal diversity, antibiotic resistance and virulence of enterococci in different environments. Seventy-one samples of farm origin (34 of food vegetables, 27 of soil and ten of irrigation water) and 19 samples of vegetables from five markets, were inoculated in Slanetz-Bartley agar plates supplemented or not with gentamicin (SB-Gen and SB plates, respectively) for enterococci recovery. Enterococci were obtained from 72.2% of tested samples in SB media (food vegetables from farms, 88.2%; soil and irrigation water, 51%; food vegetables from markets, 84.2%), and 65 enterococcal isolates were obtained. Enterococcus faecium was the most prevalent species (52.3%), followed by E. hirae (35.4%), E. faecalis (6.15%), and E. casseliflavus (6.15%). Antibiotic resistance detected among these enterococci was as follows (percentage/detected gene): ciprofloxacin (60%), erythromycin (18.4%/erm(B)), tetracycline (15.4%/tet(M)-tet(L)), kanamycin (15.4%/aph(3')-III), chloramphenicol (7.7%), streptomycin (3%/ant(6)), vancomycin (6.15%/vanC2)), teicoplanin (0%) and ampicillin (0%). High-level gentamicin-resistant (HLR-G) enterococci were detected in SB-Gen plates in 14 of 90 tested samples (15.5%), and 15 isolates were characterized: ten E. faecalis, four E. faecium and one E. hirae. All HLR-G enterococci carried the aac(6')-aph(2″), erm(B) and tet(M) genes, among other resistance genes. The HLR-G isolates showed high genetic diversity (ten different PFGE profiles), and were ascribed to the sequence types ST2, ST16, ST28 and new ST528 (in E. faecalis), and ST56, new ST885 and new ST886 (in E. faecium). Food vegetables in the farm or market settings are frequently contaminated by HLR-G enterococci, and these microorganisms could reach the human intestine through the food chain, if hygienic conditions are not followed. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.
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Characterization of multidrug-resistant diabetic foot ulcer enterococci.
Semedo-Lemsaddek, Teresa; Mottola, Carla; Alves-Barroco, Cynthia; Cavaco-Silva, Patrícia; Tavares, Luís; Oliveira, Manuela
2016-02-01
Diabetes mellitus is a highly prevalent chronic progressive disease with complications that include diabetic-foot ulcers. Enterococci isolated from diabetic-foot infections were identified, evaluated by macro-restriction analysis, and screened for virulence traits and antimicrobial resistance. All isolates were considered multidrug-resistant, cytolysin and gelatinase producers, and the majority also demonstrated the ability to produce biofilms. These results indicate the importance of enterococci in diabetic-foot infection development and persistence, especially regarding their biofilm-forming ability and resistance to clinically relevant antibiotics. Copyright © 2015 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.
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AN EFFICIENT IMMUNOMAGNETIC CAPTURE SYSTEM FOR ENTEROCOCCUS FAECALIS AND ENTEROCOCCUS FAECIUM
Enterococci detection is one of the two approved procedures by the US Environmental Protection Agency (EPA) used for the assessment of the microbiological quality of recreational waters. The action levels established by the EPA for enterococci are 35 pr 100 ml in marine recreati...
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Bae, Hee-Sung; Hou, Aixin
2013-02-01
Little is known about the impacts of fecal polluted urban runoff inputs on the structure of enterococci communities in estuarine waters. This study employed a 23S rRNA gene-based polymerase chain reaction (PCR) assay with newly designed genus-specific primers, Ent127F-Ent907R, to determine the possible impacts of Hurricane Katrina floodwaters via the 17th Street Canal discharge on the community structure of enterococci in Lake Pontchartrain. A total of 94 phylotypes were identified through the restriction fragment length polymorphism (RFLP) screening of 494 clones while only 8 phylotypes occurred among 88 cultivated isolates. Sequence analyses of representative phylotypes and their temporal and spatial distribution in the lake and the canal indicated the Katrina floodwater input introduced a large portion of Enterococcus flavescens, Enterococcus casseliflavus, and Enterococcus dispar into the lake; typical fecal groups Enterococcus faecium, Enterococcus durans, Enterococcus hirae, and Enterococcus mundtii were detected primarily in the floodwater-impacted waters. This study provides a global picture of enterococci in estuarine waters impacted by Hurricane Katrina-derived urban runoff. It also demonstrates the culture-independent PCR approach using 23S rRNA gene as a molecular marker could be a good alternative in ecological studies of enterococci in natural environments to overcome the limitation of conventional cultivation methods.
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Bushon, R.N.; Brady, A.M.; Likirdopulos, C.A.; Cireddu, J.V.
2009-01-01
Aims: The aim of this study was to examine a rapid method for detecting Escherichia coli and enterococci in recreational water. Methods and Results: Water samples were assayed for E. coli and enterococci by traditional and immunomagnetic separation/adenosine triphosphate (IMS/ATP) methods. Three sample treatments were evaluated for the IMS/ATP method: double filtration, single filtration, and direct analysis. Pearson's correlation analysis showed strong, significant, linear relations between IMS/ATP and traditional methods for all sample treatments; strongest linear correlations were with the direct analysis (r = 0.62 and 0.77 for E. coli and enterococci, respectively). Additionally, simple linear regression was used to estimate bacteria concentrations as a function of IMS/ATP results. The correct classification of water-quality criteria was 67% for E. coli and 80% for enterococci. Conclusions: The IMS/ATP method is a viable alternative to traditional methods for faecal-indicator bacteria. Significance and Impact of the Study: The IMS/ATP method addresses critical public health needs for the rapid detection of faecal-indicator contamination and has potential for satisfying US legislative mandates requiring methods to detect bathing water contamination in 2 h or less. Moreover, IMS/ATP equipment is considerably less costly and more portable than that for molecular methods, making the method suitable for field applications. ?? 2009 The Authors.
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Deshpande, Lalitagauri M; Ashcraft, Deborah S; Kahn, Heather P; Pankey, George; Jones, Ronald N; Farrell, David J; Mendes, Rodrigo E
2015-10-01
Two linezolid-resistant Enterococcus faecium isolates (MICs, 8 μg/ml) from unique patients of a medical center in New Orleans were included in this study. Isolates were initially investigated for the presence of mutations in the V domain of 23S rRNA genes and L3, L4, and L22 ribosomal proteins, as well as cfr. Isolates were subjected to pulsed-field gel electrophoresis (just one band difference), and one representative strain was submitted to whole-genome sequencing. Gene location was also determined by hybridization, and cfr genes were cloned and expressed in a Staphylococcus aureus background. The two isolates had one out of six 23S rRNA alleles mutated (G2576T), had wild-type L3, L4, and L22 sequences, and were positive for a cfr-like gene. The sequence of the protein encoded by the cfr-like gene was most similar (99.7%) to that found in Peptoclostridium difficile, which shared only 74.9% amino acid identity with the proteins encoded by genes previously identified in staphylococci and non-faecium enterococci and was, therefore, denominated Cfr(B). When expressed in S. aureus, the protein conferred a resistance profile similar to that of Cfr. Two copies of cfr(B) were chromosomally located and embedded in a Tn6218 similar to the cfr-carrying transposon described in P. difficile. This study reports the first detection of cfr genes in E. faecium clinical isolates in the United States and characterization of a new cfr variant, cfr(B). cfr(B) has been observed in mobile genetic elements in E. faecium and P. difficile, suggesting potential for dissemination. However, further analysis is necessary to access the resistance levels conferred by cfr(B) when expressed in enterococci. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
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USDA-ARS?s Scientific Manuscript database
The presence and transfer of plasmids from commensal bacteria to more pathogenic bacteria may contribute to dissemination of antimicrobial resistance. However, prevalence of plasmids from commensal bacteria in food animals such as the enterococci remains largely unknown. In this study, the prevale...
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Enterococci are frequently monitored in water samples as indicators of fecal pollution. Attention is now shifting from culture based methods for enumerating these organisms to more rapid molecular methods such as QPCR. Accurate quantitative analyses by this method requires highly...
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[Enterocin typing of enterococci].
Sedov, V I
1978-09-01
The author worked out a method of enterocinotyping on enterococci. A possibility of enterococcus typing by means of a set of enterocinogenic enterococcus strains was shown. A mobile enterococcus 4 (10 p) strain, possessing a high antagonistic activity, is suggested for enterococcus identification. Differentiation of enterococcus species by the enterocine sensitivity proved to be impossible.
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Biological contamination of aquatic environments by pathogenic microorganisms is often assessed using fecal indicator bacteria such as enterococci. The concentrations of enterococci are commonly determined by culturing techniques, but there has been recent interest in using molec...
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One approach to predictive modeling of biological contamination of recreational waters and drinking water sources involves applying process-based models that consider microbial sources, hydrodynamic transport, and microbial fate. Fecal indicator bacteria such as enterococci have ...
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A CRITICAL EVALUATION OF A FLOW CYTOMETER USED FOR DETECTING ENTEROCOCCI IN RECREATIONAL WATERS
The current U. S. Environmental Protection Agency-approved method for enterococci (Method 1600) in recreational water is a membrane filter (MF) method that takes 24 hours to obtain results. If the recreational water is not in compliance with the standard, the risk of exposure to...
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Effect of Environmental Parameters on the qPCR Signal of Enterococci in Tropical Waters
Fecal contamination is the major source of pathogens in recreational waters. The need for quick public notifications has expanded the interest in the use of a rapid, quantitative polymerase chain reaction method (qPCR) to determine enterococci density. However, very little info...
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DETECTION OF FECAL ENTEROCOCCI USING A REAL TIME PCR METHOD
In spite of their importance in public health, the detection of fecal enterococci is performed via culturing methods that are time consuming and that are subject to inaccuracies that relate to their culturable status. In order to address these problems, a real time PCR (TaqMan) ...
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The Salt Creek watershed in northwest Indiana drains into Lake Michigan near several heavily used recreational beaches. This study aimed to investigate the levels of fecal indicator bacteria, enterococci and Bacteroidales, in Salt Creek using real-time quantitative PCR (qPCR) an...
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Naserpour Farivar, Taghi; Najafipour, Reza; Johari, Pouran; Aslanimehr, Masoumeh; Peymani, Amir; Jahani Hashemi, Hoasan; Mirzaui, Baman
2014-10-01
We developed and evaluated the utility of a quadruplex Taqman real-time PCR assay that allows simultaneous identification of vancomycin-resistant genotypes and clinically relevant enterococci. The specificity of the assay was tested using reference strains of vancomycin-resistant and susceptible enterococci. In total, 193 clinical isolates were identified and subsequently genotyped using a Quadruplex Taqman real-time PCR assay and melting curve analysis. Representative Quadruplex Taqman real-time PCR amplification curve were obtained for Enterococcus faecium, Enterococcus faecalis, vanA-containing E. faecium, vanB-containing E. faecalis. Phenotypic and genotypic analysis of the isolates gave same results for 82 enterococcal isolates, while in 5 isolates, they were inconsistent. We had three mixed strains, which were detected by the TaqMan real-time PCR assay and could not be identified correctly using phenotypic methods. Vancomycin resistant enterococci (VRE) genotyping and identification of clinically relevant enterococci were rapidly and correctly performed using TaqMan real-time multiplex real-time PCR assay.
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Vancomycin resistant enterococci in farm animals – occurrence and importance
Nilsson, Oskar
2012-01-01
The view on enterococci has over the years shifted from harmless commensals to opportunistic but important pathogens mainly causing nosocomial infections. One important part of this development is the emergence of vancomycin resistance enterococci (VRE). The term VRE includes several combinations of bacterial species and resistance genes of which the most clinically important is Enterococcus faecium with vanA type vancomycin resistance. This variant is also the most common VRE among farm animals. The reason for VRE being present among farm animals is selection by extensive use of the vancomycin analog avoparcin for growth promotion. Once the use of avoparcin was discontinued, the prevalence of VRE among farm animals decreased. However, VRE are still present among farm animals and by spread via food products they could potentially have a negative impact on public health. This review is based on the PhD thesis Vancomycin Resistant Enterococci in Swedish Broilers – Emergence, Epidemiology and Elimination and makes a short summary of VRE in humans and food producing animals. The specific situation regarding VRE in Swedish broiler production is also mentioned. PMID:22957131
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Jennings, Wiley C; Chern, Eunice C; O'Donohue, Diane; Kellogg, Michael G; Boehm, Alexandria B
2018-03-01
Fecal pollution of surface waters presents a global human health threat. New molecular indicators of fecal pollution have been developed to address shortcomings of traditional culturable fecal indicators. However, there is still little information on their fate and transport in the environment. The present study uses spatially and temporally extensive data on traditional (culturable enterococci, cENT) and molecular (qPCR-enterococci, qENT and human-associated marker, HF183/BacR287) indicator concentrations in marine water surrounding highly-urbanized San Francisco, California, USA to investigate environmental and anthropogenic processes that impact fecal pollution. We constructed multivariable regression models for fecal indicator bacteria at 14 sampling stations. The human marker was detected more frequently in our study than in many other published studies, with detection frequency at some stations as high as 97%. The odds of cENT, qENT, and HF183/BacR287 exceeding health-relevant thresholds were statistically elevated immediately following discharges of partially treated combined sewage, and cENT levels dissipated after approximately 1 day. However, combined sewer discharges were not important predictors of indicator levels typically measured in weekly monitoring samples. Instead, precipitation and solar insolation were important predictors of cENT in weekly samples, while precipitation and water temperature were important predictors of HF183/BacR287 and qENT. The importance of precipitation highlights the significance of untreated storm water as a source of fecal pollution to the urban ocean, even for a city served by a combined sewage system. Sunlight and water temperature likely control persistence of the indicators via photoinactivation and dark decay processes, respectively.
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Edokpayi, Joshua N; Odiyo, John O; Msagati, Titus A M; Potgieter, Natasha
2015-04-14
Surface water has been a source of domestic water due to shortage of potable water in most rural areas. This study was carried out to evaluate the level of contamination of Mvudi River in South Africa by measuring turbidity, electrical conductivity (EC), pH, concentrations of nitrate, fluoride, chloride, and sulphate. E. coli and Enterococci were analysed using membrane filtration technique. Average pH, EC and Turbidity values were in the range of 7.2-7.7, 10.5-16.1 mS/m and 1.3-437.5 NTU, respectively. The mean concentrations of fluoride, chloride, nitrate and sulphate for both the wet and the dry seasons were 0.11 mg/L and 0.27 mg/L, 9.35 mg/L and 14.82 mg/L, 3.25 mg/L and 6.87 mg/L, 3.24 mg/L and 0.70 mg/L, respectively. E. coli and Enterococci counts for both the wet and the dry seasons were 4.81 × 103 (log = 3.68) and 5.22 × 103 (log = 3.72), 3.4 × 103 (log = 3.53) and 1.22 × 103 (log = 3.09), per 100 mL of water, respectively. The count of E. coli for both seasons did not vary significantly (p > 0.05) but Enterococci count varied significantly (p < 0.001). All the physico-chemical parameters obtained were within the recommended guidelines of the Department of Water Affairs and Forestry of South Africa and the World Health Organization for domestic and recreational water use for both seasons except turbidity and nitrates. The microbiological parameters exceeded the established guidelines. Mvudi River is contaminated with faecal organisms and should not be used for domestic purposes without proper treatment so as to mitigate the threat it poses to public health.
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Microbial and chemical contamination during and after flooding in the Ohio River-Kentucky, 2011.
Yard, Ellen E; Murphy, Matthew W; Schneeberger, Chandra; Narayanan, Jothikumar; Hoo, Elizabeth; Freiman, Alexander; Lewis, Lauren S; Hill, Vincent R
2014-09-19
Surface water contaminants in Kentucky during and after 2011 flooding were characterized. Surface water samples were collected during flood stage (May 2-4, 2011; n = 15) and after (July 25-26, 2011; n = 8) from four different cities along the Ohio River and were analyzed for the presence of microbial indicators, pathogens, metals, and chemical contaminants. Contaminant concentrations during and after flooding were compared using linear and logistic regression. Surface water samples collected during flooding had higher levels of E. coli, enterococci, Salmonella, Campylobacter, E. coli O157:H7, adenovirus, arsenic, copper, iron, lead, and zinc compared to surface water samples collected 3-months post-flood (P < 0.05). These results suggest that flooding increases microbial and chemical loads in surface water. These findings reinforce commonly recommended guidelines to limit exposure to flood water and to appropriately sanitize contaminated surfaces and drinking wells after contamination by flood water.
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Microbial and chemical contamination during and after flooding in the Ohio River—Kentucky, 2011
Yard, Ellen E.; Murphy, Matthew W.; Schneeberger, Chandra; Narayanan, Jothikumar; Hoo, Elizabeth; Freiman, Alexander; Lewis, Lauren S.; Hill, Vincent R.
2017-01-01
Surface water contaminants in Kentucky during and after 2011 flooding were characterized. Surface water samples were collected during flood stage (May 2–4, 2011; n = 15) and after (July 25–26, 2011; n = 8) from four different cities along the Ohio River and were analyzed for the presence of microbial indicators, pathogens, metals, and chemical contaminants. Contaminant concentrations during and after flooding were compared using linear and logistic regression. Surface water samples collected during flooding had higher levels of E. coli, enterococci, Salmonella, Campylobacter, E. coli O157:H7, adenovirus, arsenic, copper, iron, lead, and zinc compared to surface water samples collected 3-months post-flood (P < 0.05). These results suggest that flooding increases microbial and chemical loads in surface water. These findings reinforce commonly recommended guidelines to limit exposure to flood water and to appropriately sanitize contaminated surfaces and drinking wells after contamination by flood water. PMID:24967556
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Significance and survival of Enterococci during the house fly development.
Ghosh, Anuradha; Akhtar, Mastura; Holderman, Chris; Zurek, Ludek
2014-01-01
House flies are among the most important nonbiting insect pests of medical and veterinary importance. Larvae develop in decaying organic substrates and their survival strictly depends on an active microbial community. House flies have been implicated in the ecology and transmission of enterococci, including multi-antibiotic-resistant and virulent strains of Enterococcus faecalis. In this study, eight American Type Culture Collection type strains of enterococci including Enterococcus avium, Enterococcus casseliflavus, Enterococcus durans, Enterococcus hirae, Enterococcus mundtii, Enterococcus gallinarum, Enterococcusfaecalis, and Enterococcusfaecium were evaluated for their significance in the development of house flies from eggs to adults in bacterial feeding assays. Furthermore, the bacterial colonization of the gut of teneral flies as well as the importance of several virulence traits of E. faecalis in larval mortality was assessed. Overall survival of house flies (egg to adult) was significantly higher when grown with typically nonpathogenic enterococcal species such as E. hirae (76.0% survival), E. durans (64.0%), and E. avium (64.0%) compared with that with clinically important species E. faecalis (24.0%) and E. faecium (36.0%). However, no significant differences in survival of house fly larvae were detected when grown with E. faecalis strains carrying various virulence traits, including isogenic mutants of the human clinical isolate E. faecalis V583 with in-frame deletions of gelatinase, serine protease, and capsular polysaccharide serotype C. Enterococci were commonly detected in fly puparia (range: 75-100%; concentration: 103-105 CFU/puparium);however, the prevalence of enterococci in teneral flies varied greatly: from 25.0 (E. casseliflavus) to 89.5% (E. hirae). In conclusion, depending on the species, enterococci variably support house fly larval development and colonize the gut of teneral adults. The human pathogenic species, E. faecalis and E. faecium, poorly support larval development and are likely acquired in nature by adult flies during feeding. House fly larvae do not appear to be a suitable model organism for assessment of enterococcal virulence traits.
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Byappanahalli, Muruleedhara; Whitman, Richard L.; Shively, Dawn; Przybyla-Kelly, Katarzyna; Lukasik, Ashley M.
2010-01-01
The Metropolitan Water Reclamation District of Greater Chicago (MWRDGC) wished to know the distribution and potential sources of fecal indicator bacteria, E. coli and enterococci, in water, sediments, and upland soils along an upstream and downstream portion of the North Shore Channel (NSC) that is the receiving stream for the District’s North Side Water Reclamation Plant (NSWRP) outfall. Biweekly water and sediment samples were collected between August and October 2008 and included the following locations upstream of the outfall: Bridge Street (UPS-1), Oakton Street (UPS-2), the NSWRP outfall (OF), and downstream: Foster Avenue (DNS-1), and Wilson Avenue (DNS-2). E. coli and enterococci were consistently found in water and sediments at all sampling locations, with bacterial densities in water increasing below the NSWRP outfall; bacterial densities in sediment were more variable. On a relative measurement basis (i.e., 100 ml=100 g), both E. coli and enterococci densities were significantly higher in sediments than water. E. coli and enterococci were consistently recovered from bank soil along wooded, grassy, erosional, and depositional areas at two recreational parks, as well as other riparian areas along the river. Thus, soils along the river basin are likely sources of these bacteria to the NSC channel, introduced through runoff or other physical processes. Tributaries, such as the North Branch of the Chicago River (NBCR) that flow into NSC near Albany Ave, may provide a constant source of E. coli and enterococci to the NSC. Additionally, storm sewer outfalls may increase E. coli loadings to NSC during wet weather conditions. Our findings suggest that the abundance of nonpoint sources contributing to the overall fecal indicator bacteria (FIB) load in the NSC channel may complicate bacteria source determination and remediation efforts to protect the stream water quality.
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Cornmeal-induced resistance to ciprofloxacin and erythromycin in enterococci.
Yu, Dao-Jin; Lai, Bao-Se; Li, Jian; Ma, Yu-Fang; Yang, Fan; Li, Zhou; Luo, Xiao-Qing; Chen, Xia; Huang, Yi-Fan
2012-09-01
To establish a model ecosystem to study the impact of cornmeal on the appearance and persistence of the erythromycin (ERY)- and ciprofloxacin (CIP)-resistant phenotypes in waterborne enterococci. After the model ecosystem was established, the system was divided into six dose groups, with the addition of 8, 4, 1, 0.25, 0.05, and 0 g L(-1) sterilized cornmeal. System mud samples were collected at 0, 1, 3, 7, 14, 30, 40, 61, and 130 d, and enterococci present in the mud samples were evaluated for their sensitivities to CIP and ERY. PCR was employed to detect genes such as gyrA and ermB. The gyrA gene was sequenced, and codons 83 and 87 were analyzed for mutations. (1) The addition of 0.05-8 g L(-1) cornmeal had an impact on CIP resistance. The higher the dose of cornmeal added, the larger the impact it generated. Furthermore, the earlier the emergence of CIP-resistant strains, the greater the incidence of drug resistance. The impact of cornmeal on resistance to ERY was less consistent, and the degree of the impact was not in proportion to the dose of cornmeal added. (2) There were no mutations at codons 83 and 87 in the gyrA genes from 102 strains isolated from the model ecosystem. The incidence of ermB-positive strains of ERY-resistant enterococci (28 strains) was 78.6%, and the incidence of ermB-positive strains of ERY-sensitive enterococci (16 strains) was 0%. (1) Adding different doses of cornmeal can facilitate resistance to CIP and ERY in waterborne enterococci. In this study, the degree of resistance was related to the cornmeal dose. (2) In the model ecosystem, enterococcal CIP resistance was not caused by a gyrA gene mutation; however, in the vast majority of cases, resistance to ERY was related to the ermB resistance gene. Copyright © 2012 Elsevier Ltd. All rights reserved.
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To maintain waters that are "fishable and swimmable", mandated by the Clean Water Act, the U.S. Environmental Protection Agency (EPA) is developing a list of approved methods for use in enumerating enterococci and E. coli in ambient waters. As part of this effort, we compared mEn...
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The U.S.EPA has published recommendations for calibrator cell equivalent (CCE) densities of enterococci in recreational waters determined by a qPCR method in its 2012 Recreational Water Quality Criteria (RWQC). The CCE quantification unit stems from the calibration model used to ...
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In response to the Beach Act, the U.S. EPA has developed a quantitative PCR (qPCR) method for enterococci that meets requirements for rapid, risk-based water quality assessments of recreational waters. Widespread implementation of this method will require that different laborator...
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Combination antibiotic therapy for the treatment of infective endocarditis due to enterococci.
Leone, Sebastiano; Noviello, Silvana; Esposito, Silvano
2016-06-01
Enterococci are common causes of infective endocarditis (IE) in both health care and community-based setting. Enterococcal IE requires bactericidal therapy for an optimal outcome. For decades, cell-wall-active antimicrobial agents (penicillins or vancomycin) in combination with aminoglycosides were the cornerstone of the treatment; however, the emergence of antibiotic resistance has significantly reduced the efficacy of these regimens. Data for this review were identified by searches of MEDLINE and references from relevant articles on antibiotic combination regimens for the treatment of enterococcal IE. Abstracts presented in scientific conferences were not searched for. New effective and safe combination treatments, including double-β-lactam and daptomycin/β-lactam combination, are proving useful for the management of IE due to enterococci.
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Evaluation of Combined Peracetic acid and UV treatment for ...
The current study evaluates the effectiveness of the combined application of Peracetic acid and ultraviolet radiation as alternative disinfectant agents to the traditional chlorination of wastewater effluents. Various pathogens (E. coli, enterococci and fecal coliforms) were evaluated in the study. Four experiments were conducted using low to high PAA levels and UV dosages. E. coli and enterococci were resistant to low to moderate PAA dosage (0.5- 1 mg/L). These microbes can be removed effectively at high PAA dosage (2.5 mg/L) with 30 min contact time. Fecal coliforms were completely inactivated even at a low PAA dose of 0.7 mg/L. E. coli was more susceptible to UV disinfection than enterococci at low UV dosages. Enterococci required at least 40 mJ/cm2 for 2.5 log inactivation. In combined PAA + UV treatment, low UV intensities between 7 – 40 mJ/cm2 showed poor disinfection performance at a low PAA concentration of 1.5 mg/L. High UV intensities of 120 and 60 mJ/cm2 inactivated all the pathogens to below detection levels even at low to moderate PAA (0.7 mg/L and 1 mg/L) pretreatment concentration. Combined PAA + UV treatment at 1 mg/L (for 15 and 30 min contact time) + 120 and 60 mJ/cm2 did not show any regrowth of microbes, whereas PAA only disinfection with 15 min contact time showed regrowth of enterococci and fecal coliforms. UV only disinfection showed E. coli regrowth. • This pilot scale study was designed for providing necessary parameter optimization
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Hermanovská, Lýdia; Bardoň, Jan; Čermák, Pavel
2016-06-01
Enterococci are part of the normal intestinal flora of humans and animals. Under certain circumstances, they are capable of extraintestinal conversion to opportunistic pathogens. They cause endogenous as well as exogenous community and nosocomial infections. The gastrointestinal tract of mammals provides them with favorable conditions for acquisition and spread of resistance genes, for example to vancomycin (van), from other symbiotic bacteria. Thus, vancomycin-resistant enterococci (VRE) become potential reservoirs and vectors of the van genes. Their occurrence in the population of the Czech Republic was first reported by Kolář et al. in 1997. Some variants of the vanA gene cluster carried on Tn1546 which encode resistance to vancomycin are identical in humans and in animals. It means that animals, especially cattle, poultry and pigs, could be an important reservoir of VRE for humans. Kolář and Bardoň detected VRE in animals in the Czech Republic for the first time in 2000. In Europe, the glycopeptide antibiotic avoparcin, used as a growth stimulator, is responsible for selection of VRE strains in animals. Strains of Enterococcus faecium from animals may offer genes of antimicrobial resistance to other enterococci or they can be directly dangerous to human. This is demonstrated by finding isolates of E. faecalis from human patients and from pigs having very similar profiles of resistance and virulence genes. The goal of the paper was to point out the similarity between isolates of human and animal strains of enterococci resistant to vancomycin, and the possibility of their bilateral transfer between humans and animals.
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Liang, L.; Goh, S. G.; Vergara, G. G. R. V.; Fang, H. M.; Rezaeinejad, S.; Chang, S. Y.; Bayen, S.; Lee, W. A.; Sobsey, M. D.; Rose, J. B.
2014-01-01
The suitability of traditional microbial indicators (i.e., Escherichia coli and enterococci) has been challenged due to the lack of correlation with pathogens and evidence of possible regrowth in the natural environment. In this study, the relationships between alternative microbial indicators of potential human fecal contamination (Bacteroides thetaiotaomicron, Methanobrevibacter smithii, human polyomaviruses [HPyVs], and F+ and somatic coliphages) and pathogens (Salmonella spp., Pseudomonas aeruginosa, rotavirus, astrovirus, norovirus GI, norovirus GII, and adenovirus) were compared with those of traditional microbial indicators, as well as environmental parameters (temperature, conductivity, salinity, pH, dissolved oxygen, total organic carbon, total suspended solids, turbidity, total nitrogen, and total phosphorus). Water samples were collected from surface waters of urban catchments in Singapore. Salmonella and P. aeruginosa had significant positive correlations with most of the microbial indicators, especially E. coli and enterococci. Norovirus GII showed moderately strong positive correlations with most of the microbial indicators, except for HPyVs and coliphages. In general, high geometric means and significant correlations between human-specific markers and pathogens suggest the possibility of sewage contamination in some areas. The simultaneous detection of human-specific markers (i.e., B. thetaiotaomicron, M. smithii, and HPyVs) with E. coli and enterococcus supports the likelihood of recent fecal contamination, since the human-specific markers are unable to regrow in natural surface waters. Multiple-linear-regression results further confirm that the inclusion of M. smithii and HPyVs, together with traditional indicators, would better predict the occurrence of pathogens. Further study is needed to determine the applicability of such models to different geographical locations and environmental conditions. PMID:25416765
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Liang, L; Goh, S G; Vergara, G G R V; Fang, H M; Rezaeinejad, S; Chang, S Y; Bayen, S; Lee, W A; Sobsey, M D; Rose, J B; Gin, K Y H
2015-02-01
The suitability of traditional microbial indicators (i.e., Escherichia coli and enterococci) has been challenged due to the lack of correlation with pathogens and evidence of possible regrowth in the natural environment. In this study, the relationships between alternative microbial indicators of potential human fecal contamination (Bacteroides thetaiotaomicron, Methanobrevibacter smithii, human polyomaviruses [HPyVs], and F+ and somatic coliphages) and pathogens (Salmonella spp., Pseudomonas aeruginosa, rotavirus, astrovirus, norovirus GI, norovirus GII, and adenovirus) were compared with those of traditional microbial indicators, as well as environmental parameters (temperature, conductivity, salinity, pH, dissolved oxygen, total organic carbon, total suspended solids, turbidity, total nitrogen, and total phosphorus). Water samples were collected from surface waters of urban catchments in Singapore. Salmonella and P. aeruginosa had significant positive correlations with most of the microbial indicators, especially E. coli and enterococci. Norovirus GII showed moderately strong positive correlations with most of the microbial indicators, except for HPyVs and coliphages. In general, high geometric means and significant correlations between human-specific markers and pathogens suggest the possibility of sewage contamination in some areas. The simultaneous detection of human-specific markers (i.e., B. thetaiotaomicron, M. smithii, and HPyVs) with E. coli and enterococcus supports the likelihood of recent fecal contamination, since the human-specific markers are unable to regrow in natural surface waters. Multiple-linear-regression results further confirm that the inclusion of M. smithii and HPyVs, together with traditional indicators, would better predict the occurrence of pathogens. Further study is needed to determine the applicability of such models to different geographical locations and environmental conditions. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
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Characterization of Two Metal Binding Lipoproteins as Vaccine Candidates for Enterococcal Infections
Romero-Saavedra, Felipe; Laverde, Diana; Budin-Verneuil, Aurélie; Muller, Cécile; Bernay, Benoit; Benachour, Abdellah; Hartke, Axel; Huebner, Johannes
2015-01-01
Background Enterococcus faecium and faecalis are Gram-positive opportunistic pathogens that have become leading causes of nosocomial infections over the last decades. Especially multidrug resistant enterococci have become a challenging clinical problem worldwide. Therefore, new treatment options are needed and the identification of alternative targets for vaccine development has emerged as a feasible alternative to fight the infections caused by these pathogens. Results We extrapolate the transcriptomic data from a mice peritonitis infection model in E. faecalis to identify putative up-regulated surface proteins under infection conditions in E. faecium. After the bionformatic analyses two metal binding lipoproteins were identified to have a high homology (>72%) between the two species, the manganese ABC transporter substrate-binding lipoprotein (PsaAfm,) and the zinc ABC transporter substrate-binding lipoprotein (AdcAfm). These candidate lipoproteins were overexpressed in Escherichia coli and purified. The recombinant proteins were used to produce rabbit polyclonal antibodies that were able to induce specific opsonic antibodies that mediated killing of the homologous strain E. faecium E155 as well as clinical strains E. faecium E1162, Enterococcus faecalis 12030, type 2 and type 5. Mice were passively immunized with the antibodies raised against recombinant lipoproteins, showing significant reduction of colony counts in mice livers after the bacterial challenge and demonstrating the efficacy of these metal binding lipoproteins as promising vaccine candidates to treat infections caused by these enterococcal pathogens. Conclusion Overall, our results demonstrate that these two metal binding lipoproteins elicited specific, opsonic and protective antibodies, with an extensive cross-reactivity and serotype-independent coverage among these two important nocosomial pathogens. Pointing these two protein antigens as promising immunogens, that can be used as single components or as carrier proteins together with polysaccharide antigens in vaccine development against enterococcal infections. PMID:26322633
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Bouton, Yvette; Buchin, Solange; Duboz, Gabriel; Pochet, Sylvie; Beuvier, Eric
2009-04-01
The effect of four associations of adjunct cultures composed of mesophilic lactobacilli and enterococci, either solely or combined, on the microbiological, biochemical and sensory characteristics of Swiss-type cheese made using microfiltered cows' milk and supplemented with propionibacteria was studied. The global pattern of growth was similar to that generally observed in raw milk cheese and interactions between microflora were highlighted during ripening. Enterococci, which negatively affected the survival of streptococci starters, seemed to play a limited role in the formation of volatile compounds, probably due to their low levels throughout ripening. On the contrary, mesophilic lactobacilli, which affected the evolution of propionibacteria, enterococci and L. delbrueckii subsp. lactis starter counts, modified free amino acid content, production of volatile compounds and organoleptic properties of mature cheese. This population appeared to be of major importance in the formation of cheese flavor as it was positively related to numerous potential flavor compounds such as alcohols and their corresponding esters, acetaldehyde and 4-methyl-4-heptanone. The original mesophilic lactobacilli present in milk could play an important role in the sensorial diversity of raw milk Swiss-type cheeses such as Comte.
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Braga, Teresa M; Pomba, Constança; Lopes, M Fátima Silva
2013-01-25
Environmental dust from animal breeding facilities was never screened for the presence of enterococci, nor of vancomycin-resistant enterococci (VRE), despite the possibility of being a vehicle of transmission of strains and antibiotic resistance genes between food-producing animals and man. Bio-security measures in pig facilities include disinfection with biocides to avoid the dissemination of opportunistic pathogenic bacteria, namely enterococci and in particular VRE. We thus undertook collection of enterococci and VRE in a representative number of breeding pig facilities in Portugal (n=171) and analyzed their susceptibility to benzalkonium chloride (BC) and chlorhexidine (CHX). A prevalence of 15% of VRE was found, with 6% high-level resistance found, and MIC values for CHX and BC were similar to those commonly found among enterococcal isolates from related environments, 8 μg/ml and 4 μg/ml, respectively. Among the isolated high-level vancomycin resistant Enterococcus faecium carrying the vanA genotype, we found multilocus sequence types closely related to pig and human isolates from European countries and Brazil. These results strongly advise constant surveillance of this environment and its inclusion in future epidemiologic studies on VRE. Copyright © 2012 Elsevier B.V. All rights reserved.
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Palmer, Kelli L.; Godfrey, Paul; Griggs, Allison; Kos, Veronica N.; Zucker, Jeremy; Desjardins, Christopher; Cerqueira, Gustavo; Gevers, Dirk; Walker, Suzanne; Wortman, Jennifer; Feldgarden, Michael; Haas, Brian; Birren, Bruce; Gilmore, Michael S.
2012-01-01
ABSTRACT The enterococci are Gram-positive lactic acid bacteria that inhabit the gastrointestinal tracts of diverse hosts. However, Enterococcus faecium and E. faecalis have emerged as leading causes of multidrug-resistant hospital-acquired infections. The mechanism by which a well-adapted commensal evolved into a hospital pathogen is poorly understood. In this study, we examined high-quality draft genome data for evidence of key events in the evolution of the leading causes of enterococcal infections, including E. faecalis, E. faecium, E. casseliflavus, and E. gallinarum. We characterized two clades within what is currently classified as E. faecium and identified traits characteristic of each, including variation in operons for cell wall carbohydrate and putative capsule biosynthesis. We examined the extent of recombination between the two E. faecium clades and identified two strains with mosaic genomes. We determined the underlying genetics for the defining characteristics of the motile enterococci E. casseliflavus and E. gallinarum. Further, we identified species-specific traits that could be used to advance the detection of medically relevant enterococci and their identification to the species level. PMID:22354958
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[BIOLOGICAL ACTIVITY OF ANTIMICROBIAL PEPTIDES OF ENTEROCOCCUS FAECIUM].
Vasilchenko, A S; Rogozhin, E A; Valyshev, A V
2015-01-01
Isolate bacteriocins from Enterococcus faecium metabolites and characterize their effect on cells of Gram positive (Listeria monocytogenes) and Gram negative (Escherichia coli) bacteria. Methods of solid-phase extraction, ion-exchange and reversed phase chromatography were applied for isolation of bacteriocins from cultural medium of bacteria MALDI time-of-flight mass-spectrometry was used for characterization of the obtained preparations. The mechanism of biological effect of peptides was evaluated using DNA-tropic dyes (SYTO 9 and PI) with subsequent registration of fluorescence spectra: Atomic-force microscopy (AFM) was used for characterization of morpho-functional reaction of target cells. Peptide fractions with mass of 1.0 - 3.0 kDa were isolated from enterococci metabolites, that inhibit the growth of indicator microorganisms. E. faecium strain exoproducts were shown to increase membrane permeability during interaction with L. monocytogenes, that results in subsequent detectable disturbance of normal cell morphology of listeria. Alterations of E. coli surface during the effect of purified peptide fraction was detected using AFM. The studies carried out have revealed the effect of bacteriocins of enterococci on microorganisms with various types of cell wall composition and have confirmed the importance of bacterial barrier structure permeability disturbance in the mechanism of antimicrobial effect of enterocins.
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Accuracy of the VITEK 2 System To Detect Glycopeptide Resistance in Enterococci
van den Braak, Nicole; Goessens, Wil; van Belkum, Alex; Verbrugh, Henri A.; Endtz, Hubert P.
2001-01-01
We evaluated the accuracy of the VITEK 2 fully automated system to detect and identify glycopeptide-resistant enterococci (GRE) compared to a reference agar dilution method. The sensitivity of vancomycin susceptibility testing with VITEK 2 for the detection of vanA, vanB, and vanC1 strains was 100%. The sensitivity of vancomycin susceptibility testing of vanC2 strains was 77%. The sensitivity of teicoplanin susceptibility testing of vanA strains was 90%. Of 80 vanC enterococci, 78 (98%) were correctly identified by VITEK 2 as Enterococcus gallinarum/Enterococcus casseliflavus. Since the identification and susceptibility data are produced within 3 and 8 h, respectively, VITEK 2 appears a fast and reliable method for detection of GRE in microbiology laboratories. PMID:11136798
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Incidence of the enterococcal surface protein (esp) gene in human and animal fecal sources
Whitman, R.L.; Przybyla-Kelly, K.; Shively, D.A.; Byappanahalli, M.N.
2007-01-01
The occurrence of the enterococcal surface protein (esp) gene in the opportunistic pathogens Enterococcus faecalis and E. faecium is well-documented in clinical research. Recently, the esp gene has been proposed as a marker of human pollution in environmental waters; however, information on its relative incidence in various human and animal fecal sources is limited. We have determined the occurrence of the esp gene in enterococci from human (n = 64) and animal (n = 233) fecal samples by polymerase chain reaction using two primer sets: one presumably specific for E. faecium (espfm) and the other for both E. faecalis and E. faecium (espfs/fm). We believe that this research is the first to explore the use of espfs/fm for the detection of human waste in natural environmental settings. The incidence in human sources was 93.1% espfm and 100% espfs/fm in raw sewage influent; 30% for both espfm and espfs/fm in septic waste; and 0% espfm and 80% espfs/fm in active pit toilets. The overall occurrence of the gene in animal feces was 7.7% (espfs/fm) and 4.7% (espfm); animal types with positive results included dogs (9/43, all espfm), gulls (10/34, espfs/fm; 2/34, espfm), mice (3/22, all espfs/fm), and songbirds (5/55, all espfs/fm). The esp gene was not detected in cat (0/34), deer (0/4), goose (0/18), or raccoon (0/23) feces. The inconsistent occurrence, especially in septic and pit toilet sewage, suggests a low statistical power of discrimination between animal and human sources, which means a large number of replicates should be collected. Both espfm and espfs/fm were common in raw sewage, but neither one efficiently differentiated between animal and other human sources.
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Transport of free and particulate-associated bacteria in karst
Mahler, B.J.; Personne, J.-C.; Lods, G.F.; Drogue, C.
2000-01-01
Karst aquifers, because of their unique hydrogeologic characteristics, are extremely susceptible to contamination by pathogens. Here we present the results of an investigation of contamination of a karst aquifer by fecal indicator bacteria. Two wells intercepting zones with contrasting effective hydraulic conductivities, as determined by pump test, were monitored both during the dry season and in response to a rain event. Samples were also collected from the adjacent ephemeral surface Stream, which is known to be impacted by an upstream wastewater treatment plant after rainfall. Whole water and suspended sediment samples were analyzed for fecal coliforms and enterococci. During the dry season, pumping over a 2-day period resulted in increases in concentrations of fecal coliforms to greater than 10,000 CFU/100 ml in the high-conductivity well; enterococci and total suspended solids also increased, to a lesser degree. Toward the end of the pumping period, as much as 50% of the fecal coliforms were associated with suspended sediment. Irrigation of an up-gradient pine plantation with primary-treated wastewater is the probable source of the bacterial contamination. Sampling after a rain event revealed the strong influence of water quality of the adjacent Terrieu Creek on the ground water. Bacterial concentrations in the wells showed a rapid response to increased concentrations in the surface water, with fecal coliform concentrations in ground water ultimately reaching 60,000 CFU/100 ml. Up to 100% of the bacteria in the ground water was associated with suspended sediment at various times. The results of this investigation are evidence of the strong influence of surface water on ground water in karst terrain, including that of irrigation water. The large proportion of bacteria associated with particulates in the ground Water has important implications for public health, as bacteria associated with particulates may be more persistent and more difficult to inactivate. The high bacterial concentrations found in both wells, despite the difference in hydraulic conductivity, demonstrates the difficulty of predicting vulnerability of individual wells to bacterial contamination in karst. The extreme temporal variability in bacterial concentrations underscores the importance of event-based monitoring of the bacterial quality of public water supplies in karst. (C) 2000 Elsevier Science B.V.Karst aquifers, because of their unique hydrogeologic characteristics, are extremely susceptible to contamination by pathogens. Here we present the results of an investigation of contamination of a karst aquifer by fecal indicator bacteria. Two wells intercepting zones with contrasting effective hydraulic conductivities, as determined by pump test, were monitored both during the dry season and in response to a rain event. Samples were also collected from the adjacent ephemeral surface stream, which is known to be impacted by an upstream wastewater treatment plant after rainfall. Whole water and suspended sediment samples were analyzed for fecal coliforms and enterococci. During the dry season, pumping over a 2-day period resulted in increases in concentrations of fecal coliforms to greater than 10,000 CFU/100 ml in the high-conductivity well; enterococci and total suspended solids also increased, to a lesser degree. Toward the end of the pumping period, as much as 50% of the fecal coliforms were associated with suspended sediment. Irrigation of an up-gradient pine plantation with primary-treated wastewater is the probable source of the bacterial contamination. Sampling after a rain event revealed the strong influence of water quality of the adjacent Terrieu Creek on the ground water. Bacterial concentrations in the wells showed a rapid response to increased concentrations in the surface water, with fecal coliform concentrations in ground water ultimately reaching 60,000 CFU/100 ml. Up to 100% of the bacteria in the ground water was associated with suspended
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Effect of tannins on growth performance and intestinal ecosystem in weaned piglets.
Biagia, Giacomo; Cipollini, Irene; Paulicks, Brigitte R; Roth, Franz X
2010-04-01
Tannins are natural polyphenolic compounds that can reduce digestibility of dietary protein but also display antibacterial effects. The present study investigated, in vitro and in vivo, the effect of different levels of tannins (using a chestnut wood extract containing 75% tannins) on growth performance, intestinal microbiota and wall morphology in piglets. During a 24 h in vitro caecal fermentation, the utilisation of tannins at 0.75, 1.5, 3, and 6 g/l significantly reduced total gas production and concentrations of ammonia and volatile fatty acids and increased viable counts of enterococci and coliforms. When fed to piglets at 1.13, 2.25, and 4.5 g/kg, tannins significantly improved feed efficiency and reduced caecal concentrations of ammonia, iso-butyric, and iso-valeric acid. Viable counts of lactobacilli tended to be increased by tannins in the jejunum, while bacterial caecal counts were not affected. Depth of ileal crypts tended to decrease in piglets fed tannins at 2.25 and 4.5 g/kg. The present study showed that feeding weaned piglets with a tannin-rich wood extract can result in improved feed efficiency and reduction of intestinal bacterial proteolytic reactions. The growth-enhancing effect that tannins had on enterococci and coliforms under in vitro conditions deserves further investigation.
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Bodily, Mandy; McMullen, Kathleen M; Russo, Anthony J; Kittur, Nupur D; Hoppe-Bauer, Joan; Warren, David K
2013-08-01
Discontinuation of reflex testing of stool submitted for Clostridium difficile testing for vancomycin-resistant enterococci (VRE) led to an increase in the number of patients with healthcare-associated VRE bacteremia and bacteriuria (0.21 vs 0.36 cases per 1,000 patient-days; P<.01). Cost-benefit analysis showed reflex screening and isolation of VRE reduced hospital costs.
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Moubareck, C.; Bourgeois, N.; Courvalin, P.; Doucet-Populaire, F.
2003-01-01
It has been proposed that food animals represent the source of glycopeptide resistance genes present in enterococci from humans. We demonstrated the transfer of vanA and of other resistance genes from porcine to human Enterococcus faecium at high frequency in the digestive tract of gnotobiotic mice. Tylosin in the drinking water favored colonization by transconjugants. PMID:12937011
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Fallah, F; Yousefi, M; Pourmand, M R; Hashemi, A; Nazari Alam, A; Afshar, D
2017-07-01
Urinary tract infection (UTI) is one of the most frequent types of nosocomial and community acquired infections in humans. Management of multidrug-resistant Enterococci UTI due to the limited therapeutic options is a great challenge for physicians and clinical microbiologists. The role of bacterial biofilms in recurrent urinary tract infections and antimicrobial resistance has great importance for public health. The aim of this study was to investigate the antibiotic susceptibility pattern as well as the phenotypic and genotypic biofilm formation ability of Enterococci isolates from patients with UTI. A total of 57 isolates of Enterococci were collected from patients with UTI. Enterococcus species were identified using conventional microbiological methods. The antibiotic susceptibility patterns of the isolates were determined by the Kirby-Bauer disk-diffusion. The Modified Congo red agar (MCRA) and Microtiter plate methods used to assess the ability of biofilm formation. All enterococcal isolates were examined for determination of biofilm-related genes, esp, asa1 and ebpR using PCR method. Of 57 enterococcal isolates, 85.9% were recognized as E. faecalis and 14.1% of them were E. faecium. According to our results, linezolid, chloramphenicol and nitrofurantoin were the most effective agents against Enterococcus species. Overall, 26.5% of E. faecalis and 75% of E. faecium isolates were biofilm producers, respectively. Resistance to some antibiotics including penicillin G, ampicillin, vancomycin, nitrofurantoin and chloramphenicol, and ciprofloxacin was significantly higher among biofilm producers than non-biofilm producers Enterococci. The esp, asa1 and ebpR genes were present in 84.2%, 91.2% and 100% isolates. In this study, there was not a significant relationship between presence of these genes and biofilm formation. Our findings reinforce the role of biofilm formation in resistance to antimicrobial agents. Quinupristin/dalfopristin, tetracycline and rifampin may be used as an effective treatment for UTI caused by biofilm producers Enterococci. Our results suggest that biofilm formation is complex and depends on various factors but not just esp, asa1 and ebpR genes in Enterococcus strains. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Amachawadi, R. G.; Shelton, N. W.; Shi, X.; Vinasco, J.; Dritz, S. S.; Tokach, M. D.; Nelssen, J. L.; Scott, H. M.; Nagaraja, T. G.
2011-01-01
Copper, as copper sulfate, is increasingly used as an alternative to in-feed antibiotics for growth promotion in weaned piglets. Acquired copper resistance, conferred by a plasmid-borne, transferable copper resistance (tcrB) gene, has been reported in Enterococcus faecium and E. faecalis. A longitudinal field study was undertaken to determine the relationship between copper supplementation and the prevalence of tcrB-positive enterococci in piglets. The study was done with weaned piglets, housed in 10 pens with 6 piglets per pen, fed diets supplemented with a normal (16.5 ppm; control) or an elevated (125 ppm) level of copper. Fecal samples were randomly collected from three piglets per pen on days 0, 14, 28, and 42 and plated on M-Enterococcus agar, and three enterococcal isolates were obtained from each sample. The overall prevalence of tcrB-positive enterococci was 21.1% (38/180) in piglets fed elevated copper and 2.8% (5/180) in the control. Among the 43 tcrB-positive isolates, 35 were E. faecium and 8 were E. faecalis. The mean MICs of copper for tcrB-negative and tcrB-positive enterococci were 6.2 and 22.2 mM, respectively. The restriction digestion of the genomic DNA of E. faecium or E. faecalis with S1 nuclease yielded a band of ∼194-kbp size to which both tcrB and the erm(B) gene probes hybridized. A conjugation assay demonstrated cotransfer of tcrB and erm(B) genes between E. faecium and E. faecalis strains. The higher prevalence of tcrB-positive enterococci in piglets fed elevated copper compared to that in piglets fed normal copper suggests that supplementation of copper in swine diets selected for resistance. PMID:21705534
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Kay, D; Stapleton, C M; Wyer, M D; McDonald, A T; Crowther, J; Paul, N; Jones, K; Francis, C; Watkins, J; Wilkinson, J; Humphrey, N; Lin, B; Yang, L; Falconer, R A; Gardner, S
2005-02-01
Intestinal enterococci are the principal 'health-evidence-based' parameter recommended by WHO for the assessment of marine recreational water compliance. Understanding the survival characteristics of these organisms in nearshore waters is central to public health protection using robust modelling to effect real-time prediction of water quality at recreation sites as recently suggested by WHO and the Commission of the European Communities Previous models have more often focused on the coliform parameters and assumed two static day-time and night-time T90 values to characterise the decay process. The principal driver for enterococci survival is the received dose of irradiance from sunlight. In the water column, transmission of irradiance is determined by turbidity produced by suspended material. This paper reports the results of irradiated microcosm experiments using simulated sunlight to investigate the decay of intestinal enterococci in relatively turbid estuarine and coastal waters collected from the Severn Estuary and Bristol Channel, UK. High-turbidity estuarine waters produced a T90 value of 39.5 h. Low-turbidity coastal waters produced a much shorter T90 value of 6.6 h. In experiments receiving no irradiation, high-turbidity estuarine waters also produced a longer T90 of 65.1 h compared with corresponding low-turbidity coastal waters, T90 24.8 h. Irradiated T90 values were correlated with salinity, turbidity and suspended solids (r>0.8, p<0.001). The results suggest that enterococci decay in irradiated experiments with turbidity >200 NTU is similar to decay observed under dark conditions. Most significantly, these results suggest that modelling turbidity and or suspended solids offers a potential means of predicting T90 values in 'real-time' for discrete cells of a hydrodynamic model.
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Oliveira, Manuela; Tavares, Marta; Gomes, Diana; Touret, Tiago; São Braz, Berta; Tavares, Luís; Semedo-Lemsaddek, Teresa
2016-06-01
Periodontal disease - PD - is one of the most widespread diseases in dogs, but the role of this odontogenic infection in the dissemination of pathogenic bacteria present in the oral mucosa to other animals or pet owners is understudied. Trying to unveil the putative pathogenicity of enterococci present in the gums of dogs diagnosed with PD, thirty-two animals were investigated during routine visits to a private veterinary clinic. Seventy-one enterococci were recovered and characterized regarding species, genomic variability, virulence traits, antimicrobial resistance and biofilm-forming ability. Isolates were mainly identified as Enterococcus faecalis, with the large majority (95%) being able to produce biofilm. Regarding antibiotic resistance, all dog-enterococci were susceptible to ampicillin, amoxicillin/clavulanate, gentamicin-120, imipenem and vancomycin; while distinct levels of resistance were observed for chloramphenicol (10%), erythromycin (20%), streptomycin-300 (35%) and tetracycline (95%). For virulence traits incidence levels of 35% were observed for β-hemolysis and 25% for cylA, 25% for gelatinase and 35% for gelE; 85% harbor efaAfs and ebpABC; while ace, agg and esp are present respectively in 50, 30 and 10% of the dog-enterococci; efaAfm and acm were detected in all the Enterococcus faecium. Overall, the widespread prevalence of PD in dogs, associated with the close contact between companion animals, other animals and humans, may act as source for the dissemination of opportunistic pathogenic bacteria. Hence, aforementioned data on virulence and resistance features, emphasizes the need for active surveillance measures, such as the diagnose of PD in companion animals during routine visits to the veterinary clinic. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Adams, Hannah M; Li, Xiang; Mascio, Carmela; Chesnel, Laurent; Palmer, Kelli L
2015-07-01
Clostridium difficile infection (CDI) is an urgent public health concern causing considerable clinical and economic burdens. CDI can be treated with antibiotics, but recurrence of the disease following successful treatment of the initial episode often occurs. Surotomycin is a rapidly bactericidal cyclic lipopeptide antibiotic that is in clinical trials for CDI treatment and that has demonstrated superiority over vancomycin in preventing CDI relapse. Surotomycin is a structural analogue of the membrane-active antibiotic daptomycin. Previously, we utilized in vitro serial passage experiments to derive C. difficile strains with reduced surotomycin susceptibilities. The parent strains used included ATCC 700057 and clinical isolates from the restriction endonuclease analysis (REA) groups BI and K. Serial passage experiments were also performed with vancomycin-resistant and vancomycin-susceptible Enterococcus faecium and Enterococcus faecalis. The goal of this study is to identify mutations associated with reduced surotomycin susceptibility in C. difficile and enterococci. Illumina sequence data generated for the parent strains and serial passage isolates were compared. We identified nonsynonymous mutations in genes coding for cardiolipin synthase in C. difficile ATCC 700057, enoyl-(acyl carrier protein) reductase II (FabK) and cell division protein FtsH2 in C. difficile REA type BI, and a PadR family transcriptional regulator in C. difficile REA type K. Among the 4 enterococcal strain pairs, 20 mutations were identified, and those mutations overlap those associated with daptomycin resistance. These data give insight into the mechanism of action of surotomycin against C. difficile, possible mechanisms for resistance emergence during clinical use, and the potential impacts of surotomycin therapy on intestinal enterococci. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
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Vancomycin-Resistance Enterococci Infections in the Department of the Defense: Annual Report 2013
2014-08-01
str.r.:lioos, S€’ £l "r:’hi fl!’:: lil<i~lin ,:l ddc ~o.r-c.;s, !]:l:ho:>r rr:, aY. nflinttlirir~ :he !::f;, ·nod c ol ’ HO: Io ~:·rnhlir’U ;;· ;d ro...16. Morris JG, et al. Enterococci resistant to multiple antimicrobial agents, including vancomycin: establishment of endemicity in a university
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Differential Decay of Enterococci and Escherichia coli Originating from Two Fecal Pollution Sources
Harwood, Valerie J.; Shanks, Orin C.; Fout, G. Shay; Ashbolt, Nicholas J.
2013-01-01
Using in situ subtropical aquatic mesocosms, fecal source (cattle manure versus sewage) was shown to be the most important contributor to differential loss in viability of fecal indicator bacteria (FIB), specifically enterococci in freshwater and Escherichia coli in marine habitats. In this study, sunlight exposure and indigenous aquatic microbiota were also important contributors, whose effects on FIB also differed between water types. PMID:23377944
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Radhouani, Hajer; Igrejas, Gilberto; Pinto, Luís; Gonçalves, Alexandre; Coelho, Céline; Rodrigues, Jorge; Poeta, Patrícia
2011-08-01
Antimicrobial resistance and the mechanisms implicated were studied in 54 enterococci recovered from 57 seagull fecal samples. Almost 78% of the recovered enterococci showed resistance against one or more antibiotics and these isolates were identified to the species level. E. faecium was the most prevalent species (52.4%). High percentages of erythromycin and tetracycline resistances were found among our isolates (95.2%), and lower percentages were identified to other antibiotics. Most of the tetracycline-resistant strains carried the tet(M) and/or tet(L) genes. Genes associated with Tn916/Tn1545 and/or Tn5397 transposons were detected in 45% of tetracycline-resistant isolates. The erm(B) gene was detected in 65% of erythromycin-resistant isolates. The vat(D) and vat(E) genes were present in 5.9% and 11.8% of quinupristin/dalfopristin-resistant isolates, respectively. The ant(6)-Ia gene was identified in 57.1% of streptomycin-resistant isolates. All nine kanamycin-resistant isolates carried the aph(3)'-IIIa gene. The cat(A) gene was found in two chloramphenicol-resistant isolates. Seagulls should be considered a risk species for spreading in the environment antimicrobial resistant enterococci and can serve as a sentinel for antibiotic pressure from the surrounding farm and urban setting.
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Asadian, M; Sadeghi, J; Rastegar Lari, A; Razavi, Sh; Hasannejad Bibalan, M; Talebi, M
2016-03-01
Enterococci are known as a cause of nosocomial infections and this aptitude is intensified by the growth of antibiotic resistance. In the present study, Enterococcus faecium isolates from healthy volunteers were considered to determine the antibiotic resistance profiles and genetic correlation. A total 91 normal flora isolates of enterococci were included in this study. Identification of Enterococcus genus and species were done by biochemical and PCR methods, respectively. Sensitivity for 10 antibiotics was determined and genetic relatedness of all isolates was assessed using Repetitive Element Palindromic PCR (REP-PCR) followed by Pulse Field Gel Electrophoresis (PFGE) on the representative patterns. None of the isolates were resistant to teicoplanin, vancomycin, quinupristin-dalfopristin, linezolid, chloramphenicol, ampicillin and high-level gentamicin. On the other hand, the resistance rate was detected in 30.7%, 23%, and 3.29% of isolates for erythromycin, tetracycline and ciprofloxacin, respectively. The results of PFGE showed 19 (61.5% of our isolates) common types (CT) and 35 (38.5%) single types (ST) amongst the isolates. This is the first study to describe antibiotic resistance pattern and genetic relationship among normal flora enterococci in Iran. This study showed no prevalence of Vancomycin Resistant Enterococci (VRE) and high degrees of diversity among normal flora isolates by genotyping using PFGE. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Delpech, Gastón; Pourcel, Gisela; Schell, Celia; De Luca, María; Basualdo, Juan; Bernstein, Judith; Grenovero, Silvia; Sparo, Mónica
2012-10-01
Enterococci are part of the indigenous microbiota of human gastrointestinal tract and food of animal origin. Enterococci inhabiting non-human reservoirs play a critical role in the acquisition and dissemination of antimicrobial resistance determinants. The aim of this work was to investigate the antimicrobial resistance in Enterococcus faecalis and Enterococcus faecium strains recovered from artisanal food of animal origin. Samples of goat cheese (n = 42), cow cheese (n = 40), artisanal salami (n = 30), and minced meat for the manufacture of hamburgers (n = 60) were analyzed. Phenotypic and genotypic tests for species-level identification of the recovered isolates were carried out. Minimum inhibitory concentration (MIC) study for in vitro quantitative antimicrobial resistance assessment was performed, and 71 E. faecalis and 22 E. faecium were isolated. The recovered enterococci showed different multi-drug resistance patterns that included tretracycline, erythromycin, ciprofloxacin, linezolid, penicillin, ampicillin, vancomycin, teicoplanin, gentamicin (high-level resistance), and streptomycin (high-level resistance). VanA-type E. faecium were detected. β-lactamase activity was not observed. Artisanal foods of animal origin act as a non-human reservoir of E. faecalis and E. faecuim strains, expressing multi-resistance to antimicrobials. In conclusion, the implementation of a continuous antimicrobial resistance surveillance in enterococci isolated from artisanal food of animal origin is important.
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Xue, Jia; Lamar, Frederica G; Zhang, Bowen; Lin, Siyu; Lamori, Jennifer G; Sherchan, Samendra P
2018-05-01
Brackish water samples from Lake Pontchartrain in Louisiana were assessed for the presence of pathogenic amoeba Naegleria fowleri, which causes primary amoebic meningoencephalitis (PAM). In our study, quantitative polymerase chain reaction (qPCR) methods were used to determine N. fowleri, E. coli, and enterococci in water collected from Lake Pontchartrain. N. fowleri target sequence was detected in 35.4% (56/158) of the water samples from ten sites around the lake. Statistically significant positive correlations between N. fowleri concentration and water temperature as well as E. coli (qPCR) were observed. Multiple linear regression (MLR) model shows seasonal factor (summer or winter) has significant effect on the concentration of N. fowleri, E. coli and enterococci (qPCR) concentration. Significant positive relationships between E. coli and enterococci was observed from both qPCR (r=0.25) and culture based method (r=0.54). Meanwhile, significant positive correlation between qPCR and culture based methods for enterococci concentration was observed (r=0.33). In our study, water temperature and E. coli concentration were indicative of N. fowleri concentrations in brackish water environment. Future research is needed to determine whether sediment is a source of N. fowleri found in the water column. Copyright © 2017 Elsevier B.V. All rights reserved.
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[Influence of staphylococcin T on Enterococcus sp. growth].
Białucha, Agata; Kozuszko, Sylwia; Gospodarek, Eugenia; Bugalski, Roman Marian; Gierlotka, Krzysztof
2007-01-01
Bacteriocins are ribosomally synthesised, extracellular bacterial products. Generally, spectrum of inhibition is limited to the same or closely related species to bacteriocin producer. Staphylococcin T is produced by Staphylococcus cohnii strain. The present study concerns influence of StT to 267 Enterococcus sp. strains growth isolated between 2003 and 2006 in Department of Microbiology University Hospital of dr. A. Jurasz in Bydgoszcz. S. cohnii T antagonistic ability evaluated towards bacteries on Mueller-Hinton Agar (bio Mérieux) in aerobic conditions. After 24 and 48 hours tested enterococci suspensions were plated perpendiculary. Susceptibility to antibiotics was assessed by disc diffusion method according to the guideless of Clinical and Laboratory Standards Institute and National Reference Centre for Antimicrobial Susceptibility. Among Enterococcus sp. strains tested 7.1% were sensitive to StT. The highest percentage of sensitive enterococci isolated from wound swabs, urine, blood and pus. Enterococcus faecium strains dominated (63.2%) among enterococci sensitive to StT. Moderate inhibition degree on S. cohnii T bacteriocin action was observed in majority sensitive enterococci strains. Enterococcus sp. sensitive to StT strains were frequently multidrug resistant (68.4%). According to the study results and increasing resistance to antibiotics, StT could be an alternative agent used to treat infections caused by Enterococcus sp.
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Velraeds, M M; van der Mei, H C; Reid, G; Busscher, H J
1996-06-01
In this study, 15 Lactobacillus isolates were found to produce biosurfactants in the mid-exponential and stationary growth phases. The stationary-phase biosurfactants from lactobacillus casei subsp. rhamnosus 36 and ATCC 7469, Lactobacillus fermentum B54, and Lactobacillus acidophilus RC14 were investigated further to determine their capacity to inhibit the initial adhesion of uropathogenic Enterococcus faecalis 1131 to glass in a parallel-plate flow chamber. The initial deposition rate of E. faecalis to glass with an adsorbed biosurfactant layer from L. acidophilus RC14 or L. fermentum B54 was significantly decreased by approximately 70%, while the number of adhering enterococci after 4 h of adhesion was reduced by an average of 77%. The surface activity of the biosurfactants and their activity inhibiting the initial adhesion of E. faecalis 1131 were retained after dialysis (molecular weight cutoff, 6,000 to 8,000) and freeze-drying. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy revealed that the freeze-dried biosurfactants from L. acidophilus RC14 and L. fermentum B54 were richest in protein, while those from L. casei subsp. rhamnosus 36 and ATCC 7469 had relatively high polysaccharide and phosphate contents.
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Velraeds, M M; van der Mei, H C; Reid, G; Busscher, H J
1996-01-01
In this study, 15 Lactobacillus isolates were found to produce biosurfactants in the mid-exponential and stationary growth phases. The stationary-phase biosurfactants from lactobacillus casei subsp. rhamnosus 36 and ATCC 7469, Lactobacillus fermentum B54, and Lactobacillus acidophilus RC14 were investigated further to determine their capacity to inhibit the initial adhesion of uropathogenic Enterococcus faecalis 1131 to glass in a parallel-plate flow chamber. The initial deposition rate of E. faecalis to glass with an adsorbed biosurfactant layer from L. acidophilus RC14 or L. fermentum B54 was significantly decreased by approximately 70%, while the number of adhering enterococci after 4 h of adhesion was reduced by an average of 77%. The surface activity of the biosurfactants and their activity inhibiting the initial adhesion of E. faecalis 1131 were retained after dialysis (molecular weight cutoff, 6,000 to 8,000) and freeze-drying. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy revealed that the freeze-dried biosurfactants from L. acidophilus RC14 and L. fermentum B54 were richest in protein, while those from L. casei subsp. rhamnosus 36 and ATCC 7469 had relatively high polysaccharide and phosphate contents. PMID:8787394
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Wong, Titus; Woznow, Tracey; Petrie, Mike; Murzello, Elena; Muniak, Allison; Kadora, Amin; Bryce, Elizabeth
2016-04-01
Two ultraviolet-C (UVC)-emitting devices were evaluated for effectiveness in reducing methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and Clostridium difficile (CD). Six surfaces in rooms previously occupied by patients with MRSA, VRE, or CD were cultured before and after cleaning and after UVC disinfection. In a parallel laboratory study, MRSA and VRE suspended in trypticase soy broth were inoculated onto stainless steel carriers in triplicate, placed in challenging room areas, subjected to UVC, and subcultured to detect growth. Sixty-one rooms and 360 surfaces were assessed. Before cleaning, MRSA was found in 34.4%, VRE was found in 29.5%, and CD was found in 31.8% of rooms. Cleaning reduced MRSA-, VRE-, and CD-contaminated rooms to 27.9%, 29.5%, and 22.7%, respectively (not statistically significant). UVC disinfection further reduced MRSA-, VRE-, and CD-contaminated rooms to 3.3% (P = .0003), 4.9% (P = .0003), and 0% (P = .0736), respectively. Surface colony counts (excluding floors) decreased from 88.0 to 19.6 colony forming units (CFU) (P < .0001) after manual cleaning; UVC disinfection further reduced it to 1.3 CFU (P = .0013). In a multivariable model of the carrier study, the odds of detecting growth in broth suspensions after UVC disinfection were 7 times higher with 1 machine (odds ratio, 6.96; 95% confidence interval, 3.79-13.4) for a given organism, surface, and concentration. UVC devices are effective adjuncts to manual cleaning but vary in their ability to disinfect high concentrations of organisms in the presence of protein. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
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Impact of erosion and accretion on the distribution of enterococci in beach sands.
Gast, Rebecca J; Gorrell, Levi; Raubenheimer, Britt; Elgar, Steve
2011-09-15
Bacterial pathogens in coastal sediments may pose a health risk to users of beaches. Although recent work shows that beach sands harbor both indicator bacteria and potential pathogens, it is not known how deep within beach sands the organisms may persist nor if they may be exposed during natural physical processes. In this study, sand cores of approximately 1 m depth were collected at three sites across the beach face in Kitty Hawk, North Carolina before, during and after large waves from an offshore hurricane. The presence of DNA from the fecal indicator bacterium Enterococci was detected in subsamples at different depths within the cores by PCR amplification. Erosion and accretion of beach sand at the three sites also was determined for each sampling day. The results indicate that ocean beach sands with persisting enterococci signals could be exposed and redistributed when wind, waves, and currents cause beach erosion or accretion.
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Vilanova, Xavier; Blanch, Anicet R
2005-12-01
The changes in composition and structure of fecal coliforms (FC) and enterococci (ENT) populations, as well as the elimination of spores of sulphite-reducing bacteria (SRB), were compared between municipal sewage and their derived sludge in a biological treatment plant in order to determine any selective reduction or adsorption to sludge during the treatment process. Additionally, the persistence of antibiotic-resistant enterococcal populations in two kinds of sludge was also considered to evaluate their potential elimination in the treatment process. Microbial indicators, vancomycin-resistant and erythromycin-resistant enterococci were enumerated. The structure and composition of FC and ENT populations were determined by biochemical fingerprinting and clustering analyses. Raw and treated sewage showed a concentration of FC 1 log unit higher than ENT and nearly 2 log units higher than spores of SRB. However, the three studied indicators showed similar concentrations in both types of sludge. Consequently, FC were eliminated in higher proportion than ENT and spores of SRB in sludge. FC and ENT populations showed high diversity and similarity population indexes for all kinds of samples. Antibiotic-resistant enterococci persisted in a similar proportion in respect to total enterococci not only in treated sewage but also in sludge. The persistence of antibiotic-resistant strains in sludge as well as in treated sewage should be considered if they are used for land disposal or for water reutilization, respectively.
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Ansari, Mohd Ikram; Harb, Moustapha; Jones, Burton; Hong, Pei-Ying
2015-01-01
Molecular-based approaches were used to characterize the coastal microbiota and to elucidate the trophic state of Red Sea. Nutrient content and enterococci numbers were monitored, and used to correlate with the abundance of microbial markers. Microbial source tracking revealed the presence of >1 human-associated Bacteroides spp. at some of the near-shore sampling sites and at a heavily frequented beach. Water samples collected from the beaches had occasional exceedances in enterococci numbers, higher total organic carbon (TOC, 1.48–2.18 mg/L) and nitrogen (TN, 0.15–0.27 mg/L) than that detected in the near-shore waters. Enterococci abundances obtained from next-generation sequencing did not correlate well with the cultured enterococci numbers. The abundance of certain genera, for example Arcobacter, Pseudomonas and unclassified Campylobacterales, was observed to exhibit slight correlation with TOC and TN. Low abundance of functional genes accounting for up to 41 copies/L of each Pseudomonas aeruginosa and Campylobacter coli were detected. Arcobacter butzleri was also detected in abundance ranging from 111 to 238 copies/L. Operational taxonomic units (OTUs) associated with cyanobacteria, Prochlorococcus, Ostreococcus spp. and Gramella were more prevalent in waters that were likely impacted by urban runoffs and recreational activities. These OTUs could potentially serve as quantifiable markers indicative of the water quality. PMID:25758166
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Antibiotic and heavy metal resistance in enterococci from coastal marine sediment.
Vignaroli, Carla; Pasquaroli, Sonia; Citterio, Barbara; Di Cesare, Andrea; Mangiaterra, Gianmarco; Fattorini, Daniele; Biavasco, Francesca
2018-06-01
Sediment samples from three coastal sites - two beach resorts (Beach 1 and Beach 2 sites) and an area lying between an oil refinery and a river estuary (Estuarine site) - were analyzed for antibiotic- and heavy metal (HM)-resistant enterococci. A total of 123 enterococci, 36 E. faecium, 34 E. casseliflavus, 33 E. hirae, 5 E. faecalis, 3 E. durans, 3 E. gallinarum, and 9 Enterococcus spp, were recovered. Strains resistant to erythromycin, tetracycline and quinupristin/dalfopristin (Q/D) were recovered from all sites, whereas multidrug-resistant isolates were recovered only from "Beach 2" (14%) and "Estuarine" (3.7%). As regards HM resistance, the strains showed a high frequency (68%) of cadmium and/or copper resistance and uniform susceptibility to mercury. The prevalence of cadmium-resistant strains was significantly higher among erythromycin-resistant than among erythromycin-susceptible strains. A significant association between cadmium or copper resistance and Q/D resistance was also observed at "Estuarine" site. The levels of the two HMs in sediment from all sites were fairly low, ranging from 0.070 to 0.126 μg/g, for cadmium and from 1.00 to 7.64 μg/g for copper. Mercury was always undetectable. These findings are consistent with reports that low HM concentrations may contribute to co-selection of antibiotic-resistant bacterial strains, including enterococci. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Wangkahad, Bencharong; Mongkolsuk, Skorn; Sirikanchana, Kwanrawee
2017-02-21
We developed sewage-specific microbial source tracking (MST) tools using enterococci bacteriophages and evaluated their performance with univariate and multivariate analyses involving data below detection limits. Newly isolated Enterococci faecalis bacterial strains AIM06 (DSM100702) and SR14 (DSM100701) demonstrated 100% specificity and 90% sensitivity to human sewage without detecting 68 animal manure pooled samples of cats, chickens, cows, dogs, ducks, pigs, and pigeons. AIM06 and SR14 bacteriophages were present in human sewage at 2-4 orders of magnitude. A principal component analysis confirmed the importance of both phages as main water quality parameters. The phages presented only in the polluted water, as classified by a cluster analysis, and at median concentrations of 1.71 × 10 2 and 4.27 × 10 2 PFU/100 mL, respectively, higher than nonhost specific RYC2056 phages and sewage-specific KS148 phages (p < 0.05). Interestingly, AIM06 and SR14 phages exhibited significant correlations with each other and with total coliforms, E. coli, enterococci, and biochemical oxygen demand (Kendall's tau = 0.348 to 0.605, p < 0.05), a result supporting their roles as water quality indicators. This research demonstrates the multiregional applicability of enterococci hosts in MST application and highlights the significance of multivariate analysis with nondetects in evaluating the performance of new MST host strains.
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Godfrey, S; Watkins, J; Toop, K; Francis, C
2006-01-01
This report compares the enterococci count on samples obtained with Azide NutriDisk (AND) (sterile, dehydrated culture medium) and Slanetz and Bartley (SB) medium when exposed to a variable in incubation time and temperature. Three experiments were performed to examine the recovery of enterococci on AND and SB media using membrane filtration with respect to: (a) incubation time; (b) incubation temperature; and (c) a combination of the two. Presumptive counts were observed at 37, 41, 46 and 47 degrees C and at 20, 24, 28 and 48 h. These were compared to AWWA standard method 9230 C (44 degrees C, 44 h). Samples were confirmed using Kanamycin Aesculin Azide (KAA) agar. Friedman's ANOVA and Students t-test analysis indicated higher enumeration of enterococci when grown on AND (p = 0.45) than SB (p = < 0.001) at all temperatures with a survival threshold at 47 degrees C. Significant results for AND medium were noted at 20 h (p = 0.021), 24 h (p = 0.278) and 28 h (p = 0.543). The study concluded that the accuracy of the AND medium at a greater time and temperature range provided flexibility in incubator technology making it an appropriate alternative to SB medium for monitoring drinking water using field testing kits in developing countries.
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Suyemoto, M M; Barnes, H J; Borst, L B
2017-03-01
Pathogenic strains of Enterococcus cecorum (EC) expressing multidrug resistance have emerged. In National Antimicrobial Resistance Monitoring System (NARMS) data, EC is rarely recovered from chickens. Two NARMS methodologies (FDA and USDA) were compared with standard culture (SC) techniques for recovery of EC. NARMS methods failed to detect EC in 58 caecal samples, 20 chicken breast or six whole broiler samples. EC was recovered from 1 of 38 (2·6%) and 2 of 38 (5·2%) preharvest spinal lesions (USDA and FDA method, respectively). In contrast, using the SC method, EC was recovered from 44 of 53 (83%) caecal samples, all 38 (100%) spinal lesions, 14 of 20 (70%) chicken breast samples, and all three spinal lesions identified in whole carcasses. Compared with other Enterococcus spp., EC isolates had a higher prevalence of resistance to macrolides. The NARMS methods significantly affected recovery of enterococcal species other than EC. When the postharvest FDA method was applied to preharvest caecal samples, isolates of Enterococcus faecium were preferentially recovered. All 11 E. faecium isolates were multidrug resistant, including resistance to penicillin, daptomycin and linezolid. These findings confirm that current methodologies may not accurately identify the amount and range of antimicrobial resistance of enterococci from chicken sources. Enterococci are an important reservoir for antimicrobial resistance. This study demonstrates how current culture methods underreport resistance to macrolides in enterococci by selecting against strains of Enterococcus cecorum in pre- and postharvest chicken. Further, the application of postharvest surveillance methods to preharvest samples resulted in selective recovery of Enterococcus faecium over Enterococcus faecalis. Isolates of E. faecium recovered exhibited multidrug resistance including penicillin, daptomycin and linezolid resistance. These findings suggest that culture methodology significantly impacts the range and amount of antimicrobial resistance detected in enterococci isolated from chicken. © 2016 The Society for Applied Microbiology.
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2013-01-01
Background The microorganisms intended for use as probiotics in aquaculture should exert antimicrobial activity and be regarded as safe not only for the aquatic hosts but also for their surrounding environments and humans. The objective of this work was to investigate the antimicrobial/bacteriocin activity against fish pathogens, the antibiotic susceptibility, and the prevalence of virulence factors and detrimental enzymatic activities in 99 Lactic Acid Bacteria (LAB) (59 enterococci and 40 non-enterococci) isolated from aquatic animals regarded as human food. Results These LAB displayed a broad antimicrobial/bacteriocin activity against the main Gram-positive and Gram-negative fish pathogens. However, particular safety concerns based on antibiotic resistance and virulence factors were identified in the genus Enterococcus (86%) (Enterococcus faecalis, 100%; E. faecium, 79%). Antibiotic resistance was also found in the genera Weissella (60%), Pediococcus (44%), Lactobacillus (33%), but not in leuconostocs and lactococci. Antibiotic resistance genes were found in 7.5% of the non-enterococci, including the genera Pediococcus (12.5%) and Weissella (6.7%). One strain of both Pediococcus pentosaceus and Weissella cibaria carried the erythromycin resistance gene mef(A/E), and another two P. pentosaceus strains harboured lnu(A) conferring resistance to lincosamides. Gelatinase activity was found in E. faecalis and E. faecium (71 and 11%, respectively), while a low number of E. faecalis (5%) and none E. faecium exerted hemolytic activity. None enterococci and non-enterococci showed bile deconjugation and mucin degradation abilities, or other detrimental enzymatic activities. Conclusions To our knowledge, this is the first description of mef(A/E) in the genera Pediococcus and Weissella, and lnu(A) in the genus Pediococcus. The in vitro subtractive screening presented in this work constitutes a valuable strategy for the large-scale preliminary selection of putatively safe LAB intended for use as probiotics in aquaculture. PMID:23347637
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Vijayavel, Kannappan; Fujioka, Roger; Ebdon, James; Taylor, Huw
2010-06-01
Previous studies have shown that Escherichia coli and enterococci are unreliable indicators of fecal contamination in Hawaii because of their ability to multiply in environmental soils. In this study, the method of detecting Bacteroides phages as specific markers of sewage contamination in Hawaii's recreational waters was evaluated because these sewage specific phages cannot multiply under environmental conditions. Bacteroides hosts (GB-124, GA-17), were recovered from sewage samples in Europe and were reported to be effective in detecting phages from sewage samples obtained in certain geographical areas. However, GB-124 and GA-17 hosts were ineffective in detecting phages from sewage samples obtained in Hawaii. Bacteroides host HB-73 was isolated from a sewage sample in Hawaii, confirmed as a Bacteroides sp. and shown to recover phages from multiple sources of sewage produced in Hawaii at high concentrations (5.2-7.3 x 10(5) PFU/100 mL). These Bacteroides phages were considered as potential markers of sewage because they also survived for three days in fresh stream water and two days in marine water. Water samples from Hawaii's coastal swimming beaches and harbors, which were known to be contaminated with discharges from streams, were shown to contain moderate (20-187 CFU/100 mL) to elevated (173-816 CFU/100 mL) concentrations of enterococci. These same samples contained undetectable levels (<10 PFU/100 mL) of F+ coliphage and Bacteroides phages and provided evidence to suggest that these enterococci may not necessarily be associated with the presence of raw sewage. These results support previous conclusions that discharges from streams are the major sources of enterococci in coastal waters of Hawaii and the most likely source of these enterococci is from environmental soil rather than from sewage. 2010 Elsevier Ltd. All rights reserved.
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Torell, Erik; Cars, Otto; Olsson-Liljequist, Barbro; Hoffman, Britt-Marie; Lindbäck, Johan; Burman, Lars G.
1999-01-01
Rates of colonization with enterococci with acquired resistance to vancomycin (vancomycin-resistant enterococci [VRE]) and ampicillin (ampicillin-resistant enterococci [ARE]) were determined by using fecal samples from 670 nonhospitalized individuals and 841 patients in 27 major hospitals. Of the hospitalized patients, 181 (21.5%) were carriers of ARE and 9 (1.1%) were carriers of VRE. In univariate analyses, length of hospital stay (odds ratio [OR], 4.6; 95% confidence interval [CI], 2.5 to 8.9) and antimicrobial therapy (OR, 4.7; 95% CI, 3.3 to 6.7) were associated with ARE colonization, as were prior treatment with penicillins (OR, 3.1; 95% CI, 1.8 to 5.5), cephalosporins (OR, 2.9; 95% CI, 1.7 to 5.0), or quinolones (OR, 2.7; 95% CI, 1.5 to 4.7). In logistic regression analysis, antimicrobial therapy for at least 5 days was independently associated with ARE carriage (adjusted OR, 3.8; 95% CI, 2.6 to 5.4). Over 90% of the ARE isolates were fluoroquinolone resistant, whereas 14% of the ampicillin-susceptible Enterococcus faecium isolates were fluoroquinolone resistant. ARE carriage rates correlated with the use of fluoroquinolones (P = 0.04) but not with the use of ampicillin (P = 0.68) or cephalosporins (P = 0.40). All nine VRE isolates were E. faecium vanB and were found in one hospital. Seven of these isolates were related according to their types as determined by pulsed-field gel electrophoresis. Among the nonhospitalized individuals, the ARE carriage rate was lower (6%; P < 0.05), and only one person, who had recently returned from Africa, harbored VRE (E. faecium vanA). The absence of VRE colonization in nonhospitalized individuals reflects an epidemiological situation in Sweden radically different from that in countries in continental Europe where glycopeptides have been widely used for nonmedical purposes. PMID:10523543
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Freitas, Ana R.; Novais, Carla; Ruiz-Garbajosa, Patricia; Coque, Teresa M.; Peixe, Luísa
2009-01-01
The population structure of 56 Enterococcus faecium isolates selected from a collection of enterococci from humans, animals, and the environment in Portugal (1997 to 2007) was analyzed by multilocus sequence typing. We identified 41 sequence types clustering into CC17, CC5, CC9, CC22 and CC94, all clonal lineages comprising isolates from different hosts. Our findings highlight the role of community-associated hosts as reservoirs of enterococci able to cause human infections. PMID:19447948
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Nnane, Daniel Ekane
2011-11-15
Contamination of surface waters is a pervasive threat to human health, hence, the need to better understand the sources and spatio-temporal variations of contaminants within river catchments. River catchment managers are required to sustainably monitor and manage the quality of surface waters. Catchment managers therefore need cost-effective low-cost long-term sustainable water quality monitoring and management designs to proactively protect public health and aquatic ecosystems. Multivariate and phage-lysis techniques were used to investigate spatio-temporal variations of water quality, main polluting chemophysical and microbial parameters, faecal micro-organisms sources, and to establish 'sentry' sampling sites in the Ouse River catchment, southeast England, UK. 350 river water samples were analysed for fourteen chemophysical and microbial water quality parameters in conjunction with the novel human-specific phages of Bacteroides GB-124 (Bacteroides GB-124). Annual, autumn, spring, summer, and winter principal components (PCs) explained approximately 54%, 75%, 62%, 48%, and 60%, respectively, of the total variance present in the datasets. Significant loadings of Escherichia coli, intestinal enterococci, turbidity, and human-specific Bacteroides GB-124 were observed in all datasets. Cluster analysis successfully grouped sampling sites into five clusters. Importantly, multivariate and phage-lysis techniques were useful in determining the sources and spatial extent of water contamination in the catchment. Though human faecal contamination was significant during dry periods, the main source of contamination was non-human. Bacteroides GB-124 could potentially be used for catchment routine microbial water quality monitoring. For a cost-effective low-cost long-term sustainable water quality monitoring design, E. coli or intestinal enterococci, turbidity, and Bacteroides GB-124 should be monitored all-year round in this river catchment. Copyright © 2011 Elsevier B.V. All rights reserved.
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Bobenchik, April M.; Hindler, Janet A.; Giltner, Carmen L.; Saeki, Sandra
2014-01-01
Vitek 2 (bioMérieux, Inc., Durham, NC) is a widely used commercial antimicrobial susceptibility testing system. We compared MIC results obtained by Vitek 2 to those obtained by the Clinical and Laboratory Standards Institute (CLSI) broth microdilution (BMD) reference method for 134 staphylococcal and 84 enterococcal clinical isolates. Nineteen agents were evaluated, including all those available on Vitek 2 for testing staphylococci and enterococci. The resistance phenotypes tested included methicillin-resistant Staphylococcus aureus (MRSA) (n = 58), S. aureus with inducible clindamycin resistance (ICR) (n = 30), trimethoprim-sulfamethoxazole-resistant MRSA (n = 10), vancomycin-resistant Enterococcus (n = 37), high-level gentamicin-resistant Enterococcus (n = 15), linezolid-resistant Enterococcus (n = 5), and daptomycin-nonsusceptible Enterococcus faecalis (n = 6). For the staphylococci, there was 98.9% categorical agreement (CA). There was one very major error (VME) for gentamicin in a Staphylococcus hominis isolate, six VMEs for inducible clindamycin in S. aureus isolates, and two major errors (ME) for daptomycin in an S. aureus and a Staphylococcus epidermidis isolate. For enterococci, there was 97.3% CA. Two VMEs were observed for daptomycin in isolates of E. faecalis and 2 ME, 1 for high-level gentamicin resistance and 1 for nitrofurantoin, in E. faecium isolates. Overall, there was 98.3% CA and 99% essential agreement for the testing of staphylococci and enterococci by the Vitek 2. With the exception of detecting ICR in S. aureus, Vitek 2 performed reliably for antimicrobial susceptibility testing of staphylococci and enterococci. PMID:24478467
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Furlaneto-Maia, Luciana; Rocha, Kátia Real; Siqueira, Vera Lúcia Dias; Furlaneto, Márcia Cristina
2014-01-01
Enterococci are increasingly responsible for nosocomial infections worldwide. This study was undertaken to compare the identification and susceptibility profile using an automated MicrosScan system, PCR-based assay and disk diffusion assay of Enterococcus spp. We evaluated 30 clinical isolates of Enterococcus spp. Isolates were identified by MicrosScan system and PCR-based assay. The detection of antibiotic resistance genes (vancomycin, gentamicin, tetracycline and erythromycin) was also determined by PCR. Antimicrobial susceptibilities to vancomycin (30 µg), gentamicin (120 µg), tetracycline (30 µg) and erythromycin (15 µg) were tested by the automated system and disk diffusion method, and were interpreted according to the criteria recommended in CLSI guidelines. Concerning Enterococcus identification the general agreement between data obtained by the PCR method and by the automatic system was 90.0% (27/30). For all isolates of E. faecium and E. faecalis we observed 100% agreement. Resistance frequencies were higher in E. faecium than E. faecalis. The resistance rates obtained were higher for erythromycin (86.7%), vancomycin (80.0%), tetracycline (43.35) and gentamicin (33.3%). The correlation between disk diffusion and automation revealed an agreement for the majority of the antibiotics with category agreement rates of > 80%. The PCR-based assay, the van(A) gene was detected in 100% of vancomycin resistant enterococci. This assay is simple to conduct and reliable in the identification of clinically relevant enterococci. The data obtained reinforced the need for an improvement of the automated system to identify some enterococci. PMID:24626409
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Dada, Ayokunle Christopher; Ahmad, Asmat; Usup, Gires; Heng, Lee Yook
2013-02-01
We report the first study on the occurrence of antibiotic-resistant enterococci in coastal bathing waters in Malaysia. One hundred and sixty-five enterococci isolates recovered from two popular recreational beaches in Malaysia were speciated and screened for antibiotic resistance to a total of eight antibiotics. Prevalence of Enterococcus faecalis and Enterococcus faecium was highest in both beaches. E. faecalis/E. faecium ratio was 0.384:1 and 0.375:1, respectively, for isolates from Port Dickson (PD) and Bagan Lalang (BL). Analysis of Fisher's exact test showed that association of prevalence of E. faecalis and E. faecium with considered locations was not statistically significant (p < 0.05). Chi-square test revealed significant differences (χ(2) = 82.630, df = 20, p < 0.001) in the frequency of occurrence of enterococci isolates from the considered sites. Resistance was highest to nalidixic acid (94.84 %) and least for chloramphenicol (8.38 %). One-way ANOVA using Tukey-Kramer multiple comparison test showed that resistance to ampicillin was higher in PD beach isolates than BL isolates and the difference was extremely statistically significant (p < 0.0001). Frequency of occurrence of multiple antibiotic resistance (MAR) isolates were higher for PD beach water (64.29 %) as compared to BL beach water (13.51 %), while MAR indices ranged between 0.198 and 0.48. The results suggest that samples from Port Dickson may contain MAR bacteria and that this could be due to high-risk faecal contamination from sewage discharge pipes that drain into the sea water.
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Klein, Günter; Pack, Alexander; Reuter, Gerhard
1998-01-01
The food chain, especially raw minced meat, is thought to be responsible for an increase in the incidence of vancomycin-resistant enterococci (VRE) in human nosocomial infections. Therefore, 555 samples from 115 batches of minced beef and pork from a European Union-licensed meat-processing plant were screened for the occurrence of VRE. The processed meat came from 45 different slaughterhouses in Germany. Enterococci were isolated directly from Enterococcosel selective agar plates and also from Enterococcosel selective agar plates supplemented with 32 mg of vancomycin per liter. In addition, peptone broth was used in a preenrichment procedure, and samples were subsequently plated onto Enterococcosel agar containing vancomycin. To determine resistance, 209 isolates from 275 samples were tested with the glycopeptides vancomycin, teicoplanin, and avoparcin and 19 other antimicrobial substances by using a broth microdilution test. When the direct method was used, VRE were found in 3 of 555 samples (0.5%) at a concentration of 1.0 log CFU/g of minced meat. When the preenrichment procedure was used, 8% of the samples were VRE positive. Our findings indicate that there is a low incidence of VRE in minced meat in Germany. In addition, the resistance patterns of the VRE isolates obtained were different from the resistance patterns of clinical isolates. A connection between the occurrence of VRE in minced meat and nosocomial infections could not be demonstrated on the basis of our findings. PMID:9572958
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Hartz, A; Cuvelier, M; Nowosielski, K; Bonilla, T D; Green, M; Esiobu, N; McCorquodale, D S; Rogerson, A
2008-01-01
Fecal bacteria have traditionally been used as indicator organisms to monitor the quality of recreational waters. Recent work has questioned the robustness of traditional indicators, particularly at seawater bathing beaches. For example, a study of Florida beaches found unexpectedly high abundances of Escherichia coli, fecal coliforms, and enterococci in beach sand. The aim of the present study was to explain these abundances by assessing the survival of E. coli and enterococci in beach sand relative to seawater. We used a combination of quantitative laboratory mesocosm experiments and field observations. Results suggested that E. coli and enterococci exhibited increased survivability and growth in sand relative to seawater. Because fecal bacteria are capable of replicating in sand, at least under controlled laboratory conditions, the results suggest that sand may be an important reservoir of metabolically active fecal organisms. Experiments with "natural" mesocosms (i.e., unsterilized sand or water rich in micropredators and native bacteria) failed to show the same increases in fecal indicators as was found in sterile sand. It is postulated that this was due to predation and competition with indigenous bacteria in these "natural" systems. Nonetheless, high populations of indicators were maintained and recovered from sand over the duration of the experiment as opposed to the die-off noted in water. Indicator bacteria may wash out of sand into shoreline waters during weather and tidal events, thereby decreasing the effectiveness of these indicators as predictors of health risk and complicating the interpretations for water quality managers.
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Activity of plant flavonoids against antibiotic-resistant bacteria.
Xu, H X; Lee, S F
2001-02-01
Thirty eight plant-derived flavonoids representing seven different structural groups were tested for activities against antibiotic-resistant bacteria using the disc-diffusion assay and broth dilution assay. Among the flavonoids examined, four flavonols (myricetin, datiscetin, kaempferol and quercetin) and two -flavones (flavone and luteolin) exhibited inhibitory activity against methicillin-resistant Staphylococcus aureus (MRSA). Myricetin was also found to inhibit the growth of multidrug-resistant Burkholderia -cepacia, vancomycin-resistant enterococci (VRE) and other medically important organisms such as -Klebsiella pneumoniae and Staphylococcus epidermidis. Myricetin was bactericidal to B. cepacia. The results of the radiolabel incorporation assay showed that myricetin inhibited protein synthesis by -B. cepacia. The structure-activity relationship of these flavonoids is discussed. Copyright 2001 John Wiley & Sons, Ltd.
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Steinka, Izabela
2005-01-01
Aim of research was to assess the influence of lactic acid cheese micro-flora on water phase fluctuation between surface of products and the packaging. Results of research showed that changes of water content could be expressed with the help of polynomial cubic equation. From linear correlation equations describing level of micro-flora in lactic acid cheese and water content it resulted micro-organisms had a significant influence on the water phase fluctuation. Values of determined coefficients of determination suggested that yeast, enterococci and staphylococci had a significant influence on water fluctuation between product and the packaging.
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Steinka, Izabela
2007-01-01
The study aimed at assessing changes of physical properties of package lactic acid cheese and the PA/PE and Cryovac laminates after storage of this products. The fluctuation of water in the product and swelling of packaging caused changes in their mass. The changes in the packaging mass could also result from the interactions between micro-organisms present in product. It was found that staphylococci, enterococci and Escherichia coli were the micro-organisms that had contributed to changes of packaging mass to a highest degree. Changes were described with the help of response surface models.
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Obiri-Danso, K; Adonadaga, M G; Hogarh, J N
2011-01-01
The effect of agrochemical use in agricultural activities on the drinking water quality of ground and surface water within Agogo, a prominent tomato growing area in the Ashanti region of Ghana was assessed by monitoring physicochemical parameters, trace metals and microbial quality of two water sources. Levels of contamination were greater in surface water than groundwater. Trace metal levels (mg/L) were 1.40, 0.12, 0.08 and 0.18 in surface water and 0.08, 0.10, 0.05 and 0.08 in groundwater for Fe, Pb, Zn and Cd, respectively. Lead and Cd in surface and groundwater exceeded USEPA maximum acceptable levels (MCLs) for drinking water. Bacterial indicator numbers (geometric means/100 mL) in surface water varied from 9.35 x 10⁵ to 1.57 x 10¹¹ for total coliforms, 4.15 x 10⁴ to 2.10 x 10⁷ for faecal coliforms and 2.80 x 10 to 3.25 x 10² for enterococci, but none was found in groundwater.
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Selbig, William R.; Buer, Nicolas
2018-05-11
Three permeable pavement surfaces - asphalt (PA), concrete (PC), and interlocking pavers (PIP) - were evaluated side-by-side to measure changes to the infiltrative capacity and water quality of stormwater runoff originating from a conventional asphalt parking lot in Madison, Wisconsin. During the 24-month monitoring period (2014-16), all three permeable pavements resulted in statistically significant reductions in the cumulative load of solids (total suspended solids and suspended sediment), total phosphorus, Escherichia coli (E. coli), and Enterococci. Most of the removal occurred through capture and retention in the void spaces of each permeable surface and aggregate base. The largest reduction in total suspended solids was for PC at 80 percent, followed by PIP and PA at 69 and 65 percent, respectively. Reductions (generally less than 50 percent) in total phosphorus also were observed, which might have been tempered by increases in the dissolved fraction observed in PIP and PA. Conversely, PC results indicated a slight reduction in dissolved phosphorus but failed to meet statistical significance. E. coli and Enterococci were reduced by about 80 percent for PC, almost twice the amount observed for PIP and PA.Results for the PIP and PC surfaces initially indicated higher pollutant load reduction than results for the PA surface. The efficiency of PIP and PC surfaces capturing sediment, however, led to a decline in infiltration rates that resulted in more runoff flowing over, not through, the permeable surface. This result led to a decline in treatment until the permeable surface was partially restored through maintenance practices, to which PIP responded more dramatically than PC or PA. Conversely, the PA surface was capable of infiltrating most of the influent runoff volume during the monitoring period and, thus, continued to provide some level of treatment. The combined effect of underdrain and overflow drainage resulted in similar pollutant treatment for all three permeable surfaces.Temperatures below each permeable surface generally followed changes in air temperature with a more gradual response observed in deeper layers. Therefore, permeable pavement may do little to mitigate heated runoff during summer. During winter, deeper layers remained above freezing even when air temperature was below freezing. Although temperatures were not high enough to melt snow or ice accumulated on the surface, temperatures below each permeable pavement did allow void spaces to remain open, which promoted infiltration of melted ice and snow as air temperatures rose above freezing. These open void spaces could potentially reduce the need for application of deicing agents in winter because melted snow and ice would infiltrate, thereby preventing refreezing of pooled water in what is known as the “black ice” effect.
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Putnam, Larry D.; Hoogestraat, Galen K.; Sawyer, J. Foster
2008-01-01
Onsite wastewater disposal systems (OWDS) are used extensively in the Black Hills of South Dakota where many of the watersheds and aquifers are characterized by fractured or solution-enhanced bedrock with thin soil cover. A study was conducted during 2006-08 to characterize water-quality effects and indicators of OWDS. Water samples were collected and analyzed for potential indicators of OWDS, including chloride, bromide, boron, nitrite plus nitrate (NO2+NO3), ammonia, major ions, nutrients, selected trace elements, isotopes of nitrate, microbiological indicators, and organic wastewater compounds (OWCs). The microbiological indicators were fecal coliforms, Escherichia coli (E. coli), enterococci, Clostridium perfringens (C. perfringens), and coliphages. Sixty ground-water sampling sites were located either downgradient from areas of dense OWDS or in background areas and included 25 monitoring wells, 34 private wells, and 1 spring. Nine surface-water sampling sites were located on selected streams and tributaries either downstream or upstream from residential development within the Precambrian setting. Sampling results were grouped by their hydrogeologic setting: alluvial, Spearfish, Minnekahta, and Precambrian. Mean downgradient dissolved NO2+NO3 concentrations in ground water for the alluvial, Spearfish, Minnekahta, and Precambrian settings were 0.734, 7.90, 8.62, and 2.25 milligrams per liter (mg/L), respectively. Mean downgradient dissolved chloride concentrations in ground water for these settings were 324, 89.6, 498, and 33.2 mg/L, respectively. Mean downgradient dissolved boron concentrations in ground water for these settings were 736, 53, 64, and 43 micrograms per liter (ug/L), respectively. Mean dissolved surface-water concentrations for NO2+NO3, chloride, and boron for downstream sites were 0.222 mg/L, 32.1 mg/L, and 28 ug/L, respectively. Mean values of delta-15N and delta-18O (isotope ratios of 14N to 15N and 18O to 16O relative to standard ratios) for nitrate in ground-water samples were 10.4 and -2.0 per mil (0/100), respectively, indicating a relatively small contribution from synthetic fertilizer and probably a substantial contribution from OWDS. The surface-water sample with the highest dissolved NO2+NO3 concentration of 1.6 mg/L had a delta-15N value of 12.36 0/100, which indicates warm-blooded animals (including humans) as the nitrate source. Fecal coliforms were detected in downgradient ground water most frequently in the Spearfish (19 percent) and Minnekahta (9.7 percent) settings. E. coli was detected most frequently in the Minnekahta (29 percent) and Spearfish (13 percent) settings. Enterococci were detected more frequently than other microbiological indicators in all four settings. Fecal coliforms and E. coli were detected in 73 percent and 95 percent of all surface-water samples, respectively. Enterococci, coliphages (somatic), and C. perfringens were detected in 50, 70, and 50 percent of surface-water samples, respectively. Of the 62 OWC analytes, 12 were detected only in environmental samples, 10 were detected in at least one environmental and one blank sample (not necessarily companion pairs), 2 were detected only in blank samples, and 38 were not detected in any blank, environmental, or replicate sample from either ground or surface water. Eleven different organic compounds were detected in ground-water samples at eight different sites. The most frequently occurring compound was DEET, which was found in 32 percent of the environmental samples, followed by tetrachloroethene, which was detected in 20 percent of the samples. For surface-water samples, 16 organic compounds were detected in 9 of the 10 total samples. The compound with the highest occurrence in surface-water samples was camphor, which was detected in 50 percent of samples. The alluvial setting was characterized by relatively low dissolved NO2+NO3 concentrations, detection of ammonia nitrogen, and relatively high concentr
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Linezolid Surveillance Results for the United States (LEADER Surveillance Program 2014)
Mendes, Rodrigo E.; Hogan, Patricia A.; Streit, Jennifer M.; Ross, James E.; Jones, Ronald N.
2016-01-01
The linezolid experience and accurate determination of resistance (LEADER) surveillance program has monitored linezolid activity, spectrum, and resistance since 2004. In 2014, a total of 6,865 Gram-positive pathogens from 60 medical centers from 36 states were submitted. The organism groups evaluated were Staphylococcus aureus (3,106), coagulase-negative staphylococci (CoNS; 797), enterococci (855), Streptococcus pneumoniae (874), viridans group streptococci (359), and beta-hemolytic streptococci (874). Susceptibility testing was performed by reference broth microdilution at the monitoring laboratory. Linezolid-resistant isolates were confirmed by repeat testing. PCR and sequencing were performed to detect mutations in 23S rRNA, L3, L4, and L22 proteins and acquired genes (cfr and optrA). The MIC50/90 for Staphylococcus aureus was 1/1 μg/ml, with 47.2% of isolates being methicillin-resistant Staphylococcus aureus. Linezolid was active against all Streptococcus pneumoniae strains and beta-hemolytic streptococci with a MIC50/90 of 1/1 μg/ml and against viridans group streptococci with a MIC50/90 of 0.5/1 μg/ml. Among the linezolid-nonsusceptible MRSA strains, one strain harbored cfr only (MIC, 4 μg/ml), one harbored G2576T (MIC, 8 μg/ml), and one contained cfr and G2576T with L3 changes (MIC, ≥8 μg/ml). Among CoNS, 0.75% (six isolates) of all strains demonstrated linezolid MIC results of ≥4 μg/ml. Five of these were identified as Staphylococcus epidermidis, four of which contained cfr in addition to the presence of mutations in the ribosomal proteins L3 and L4, alone or in combination with 23S rRNA (G2576T) mutations. Six enterococci (0.7%) were linezolid nonsusceptible (≥4 μg/ml; five with G2576T mutations, including one with an additional cfr gene, and one strain with optrA only). Linezolid demonstrated excellent activity and a sustained susceptibility rate of 99.78% overall. PMID:26833165
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Evidence for Horizontal Gene Transfer in Evolution of Elongation Factor Tu in Enterococci
Ke, Danbing; Boissinot, Maurice; Huletsky, Ann; Picard, François J.; Frenette, Johanne; Ouellette, Marc; Roy, Paul H.; Bergeron, Michel G.
2000-01-01
The elongation factor Tu, encoded by tuf genes, is a GTP binding protein that plays a central role in protein synthesis. One to three tuf genes per genome are present, depending on the bacterial species. Most low-G+C-content gram-positive bacteria carry only one tuf gene. We have designed degenerate PCR primers derived from consensus sequences of the tuf gene to amplify partial tuf sequences from 17 enterococcal species and other phylogenetically related species. The amplified DNA fragments were sequenced either by direct sequencing or by sequencing cloned inserts containing putative amplicons. Two different tuf genes (tufA and tufB) were found in 11 enterococcal species, including Enterococcus avium, Enterococcus casseliflavus, Enterococcus dispar, Enterococcus durans, Enterococcus faecium, Enterococcus gallinarum, Enterococcus hirae, Enterococcus malodoratus, Enterococcus mundtii, Enterococcus pseudoavium, and Enterococcus raffinosus. For the other six enterococcal species (Enterococcus cecorum, Enterococcus columbae, Enterococcus faecalis, Enterococcus sulfureus, Enterococcus saccharolyticus, and Enterococcus solitarius), only the tufA gene was present. Based on 16S rRNA gene sequence analysis, the 11 species having two tuf genes all have a common ancestor, while the six species having only one copy diverged from the enterococcal lineage before that common ancestor. The presence of one or two copies of the tuf gene in enterococci was confirmed by Southern hybridization. Phylogenetic analysis of tuf sequences demonstrated that the enterococcal tufA gene branches with the Bacillus, Listeria, and Staphylococcus genera, while the enterococcal tufB gene clusters with the genera Streptococcus and Lactococcus. Primary structure analysis showed that four amino acid residues encoded within the sequenced regions are conserved and unique to the enterococcal tufB genes and the tuf genes of streptococci and Lactococcus lactis. The data suggest that an ancestral streptococcus or a streptococcus-related species may have horizontally transferred a tuf gene to the common ancestor of the 11 enterococcal species which now carry two tuf genes. PMID:11092850
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Ligozzi, Marco; Bernini, Cinzia; Bonora, Maria Grazia; de Fatima, Maria; Zuliani, Jessica; Fontana, Roberta
2002-01-01
A study was conducted to evaluate the new VITEK 2 system (bioMérieux) for identification and antibiotic susceptibility testing of gram-positive cocci. Clinical isolates of Staphylococcus aureus (n = 100), coagulase-negative staphylococci (CNS) (n = 100), Enterococcus spp. (n = 89), Streptococcus agalactiae (n = 29), and Streptococcus pneumoniae (n = 66) were examined with the ID-GPC identification card and with the AST-P515 (for staphylococci), AST-P516 (for enterococci and S. agalactiae) and AST-P506 (for pneumococci) susceptibility cards. The identification comparison methods were the API Staph for staphylococci and the API 20 Strep for streptococci and enterococci; for antimicrobial susceptibility testing, the agar dilution method according to the procedure of the National Committee for Clinical Laboratory Standards (NCCLS) was used. The VITEK 2 system correctly identified to the species level (only one choice or after simple supplementary tests) 99% of S. aureus, 96.5% of S. agalactiae, 96.9% of S. pneumoniae, 92.7% of Enterococcus faecalis, 91.3% of Staphylococcus haemolyticus, and 88% of Staphylococcus epidermidis but was least able to identify Enterococcus faecium (71.4% correct). More than 90% of gram-positive cocci were identified within 3 h. According to the NCCLS breakpoints, antimicrobial susceptibility testing with the VITEK 2 system gave 96% correct category agreement, 0.82% very major errors, 0.17% major errors, and 2.7% minor errors. Antimicrobial susceptibility testing showed category agreement from 94 to 100% for S. aureus, from 90 to 100% for CNS, from 91 to 100% for enterococci, from 96 to 100% for S. agalactiae, and from 91 to 100% for S. pneumoniae. Microorganism-antibiotic combinations that gave very major errors were CNS-erythromycin, CNS-oxacillin, enterococci-teicoplanin, and enterococci-high-concentration gentamicin. Major errors were observed for CNS-oxacillin and S. agalactiae-tetracycline combinations. In conclusion the results of this study indicate that the VITEK 2 system represents an accurate and acceptable means for performing identification and antibiotic susceptibility tests with medically relevant gram-positive cocci. PMID:11980942
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Agga, Getahun E; Schmidt, John W; Arthur, Terrance M
2016-10-01
We compared the occurrences of 3rd-generation cephalosporin-resistant (3GC r ), tetracycline-resistant (TET r ), and trimethoprim-sulfamethoxazole-resistant (COT r ) Escherichia coli, 3GC r and nalidixic acid-resistant (NAL r ) Salmonella enterica, and erythromycin-resistant (ERY r ) enterococci from the fecal samples of ceftiofur-treated (n = 162) and nonantimicrobial-treated (n = 207) comingled beef cows ≥8 years old, for which complete antimicrobial treatment records were available. The prevalence of 3GC r (17%; n = 369), TET r (88%), COT r E. coli (22%), and ERY r enterococci (69%) was not significantly (p > 0.05) associated with ceftiofur treatment, prior history of other antimicrobial treatments, or duration of time between last antimicrobial treatment and sampling. 3GC r and NAL r S. enterica were not detected. The prevalence of tetB was significantly (p < 0.05) higher compared with tetA among TET r E. coli. However, the prevalence of tetA was significantly (p < 0.05) higher than tetB among 3GC r and COT r E. coli. There was a significant (p < 0.05) association between tetM and ermB among ERY r enterococci. In conclusion, occurrences of 3GC r , TET r , and COT r E. coli and ERY r enterococci in comingled antimicrobial-treated and nonantimicrobial-treated beef cows were not associated with ceftiofur or other antimicrobial use, indicating that other factors influenced the observed levels of antimicrobial-resistant bacteria in feces of beef cows.
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Byappanahalli, M.N.; Whitman, R.L.; Shively, D.A.; Ting, W.T.E.; Tseng, C.C.; Nevers, M.B.
2006-01-01
We studied the shoreward and seasonal distribution of E. coli and enterococci in sand (at the water table) at two southern Lake Michigan beaches - Dunbar and West Beach (in Indiana). Deep, backshore sand (??? 20 m inland) was regularly sampled for 15 months during 2002-2003. E. coli counts were not significantly different in samples taken at 5-m intervals from 0-40 M inland (P = 0.25). Neither E. coli nor enterococci mean counts showed any correlation or differences between the two beaches studied. In laboratory experiments, E. coli readily grew in sand supplemented with lake plankton, suggesting that in situ E. coli growth may occur when temperature and natural organic sources are adequate. Of the 114 sand enterococci isolates tested, positive species identification was obtained for only 52 (46%), with E. faecium representing the most dominant species (92%). Genetic characterization by ribotyping revealed no distinct genotypic pattern (s) for E. coli, suggesting that the sand population was rather a mixture of numerous strains (genotypes). These findings indicate that E. coli and enterococci can occur and persist for extended periods in backshore sand at the groundwater table. Although this study was limited to two beaches of southern Lake Michigan, similar findings can be expected at other temperate freshwater beaches. The long-term persistence of these bacteria, perhaps independent of pollution events, complicates their use as indicator organisms. Further, backshore sand at the water table may act as a reservoir for these bacteria and potentially for human pathogens. ?? IWA Publishing 2006.
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Chen, Z; Jiang, X
2017-06-01
The thermal resistance of desiccation-adapted Salmonella Senftenberg 775/W was compared with those of indigenous enterococci and total aerobic bacteria in poultry litter. Aged broiler litter and composted turkey litter with 20, 30, 40 and 50% moisture contents were inoculated with desiccation-adapted Salm. Senftenberg 775/W, and then heat-treated at 75 and 85°C. Compared to total aerobic bacteria, there were better correlations between mean log reductions of desiccation-adapted Salm. Senftenberg 775/W and indigenous enterococci in broiler litter samples with 20, 30, 40 and 50% moisture contents at 75°C (R 2 > 0·91), and 20, 30 and 40% moisture contents at 85°C (R 2 > 0·87). The mean log reductions of Salm. Senftenberg 775/W were better correlated with those of indigenous enterococci in turkey litter samples with 20, 30, 40 and 50% moisture contents at 75°C (R 2 > 0·88), and 20 and 30% moisture contents at 85°C (R 2 = 0·83) than those of total aerobic bacteria, which had a better correlation in turkey litter sample with 40% (R 2 = 0·98) moisture content at 85°C. Indigenous enterococci may be used to validate the thermal processing of poultry litter, as it predicts the survival behaviour of Salmonella under some treatment conditions. This study provides some scientific data for poultry litter processors when validating the effectiveness of thermal processing. © 2017 The Society for Applied Microbiology.
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Heat resistance of thermoduric enterococci isolated from milk.
McAuley, Catherine M; Gobius, Kari S; Britz, Margaret L; Craven, Heather M
2012-03-15
Enterococci are reported to survive pasteurisation but the extent of their survival is unclear. Sixty-one thermoduric enterococci isolates were selected from laboratory pasteurised milk obtained from silos in six dairy factories. The isolates were screened to determine log(10) reductions incurred after pasteurisation (63°C/30 min) and ranked from highest to lowest log(10) reduction. Two isolates each of Enterococcus faecalis, Enterococcus faecium, Enterococcus durans and Enterococcus hirae, exhibiting the median and the greatest heat resistance, as well as E. faecalis ATCC 19433, were selected for further heat resistance determinations using an immersed coil apparatus. D values were calculated from survival curves plotted from viable counts obtained after heating isolates in Brain Heart Infusion Broth at 63, 69, 72, 75 and 78°C followed by rapid cooling. At 72°C, the temperature employed for High Temperature Short Time (HTST) pasteurisation (72°C/15s), the D values extended from 0.3 min to 5.1 min, depending on the isolate and species. These data were used to calculate z values, which ranged from 5.0 to 9.8°C. The most heat sensitive isolates were E. faecalis (z values 5.0, 5.7 and 7.5°C), while the most heat resistant isolates were E. durans (z values 8.7 and 8.8°C), E. faecium (z value 9.0°C) and E. hirae (z values 8.5 and 9.8°C). The data show that heat resistance in enterococci is highly variable. Copyright © 2011 Elsevier B.V. All rights reserved.
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Graczyk, Thaddeus K; Sunderland, Deirdre; Awantang, Grace N; Mashinski, Yessika; Lucy, Frances E; Graczyk, Zofi; Chomicz, Lidia; Breysse, Patrick N
2010-04-01
During summer months, samples of marine beach water were tested weekly for human waterborne pathogens in association with high and low bather numbers during weekends and weekdays, respectively. The numbers of bathers on weekends were significantly higher than on weekdays (P < 0.001), and this was associated with a significant (P < 0.04) increase in water turbidity. The proportion of water samples containing Cryptosporidium parvum, Giardia duodenalis, and Enterocytozoon bieneusi was significantly higher (P < 0.03) on weekends than on weekdays, and significantly (P < 0.01) correlated with enterococci counts. The concentration of all three waterborne pathogens was significantly correlated with bather density (P < 0.01). The study demonstrated that: (a) human pathogens were present in beach water on days deemed acceptable for bathing according to fecal bacterial standards; (b) enterococci count was a good indicator for the presence of Cryptosporidium, Giardia, and microsporidian spores in recreational marine beach water; (c) water should be tested for enterococci during times when bather numbers are high; (d) re-suspension of bottom sediments by bathers caused elevated levels of enterococci and waterborne parasites, thus bathers themselves can create a non-point source for water contamination; and (e) exposure to recreational bathing waters can play a role in epidemiology of microsporidiosis. In order to protect public health, it is recommended to: (a) prevent diapered children from entering beach water; (b) introduce bather number limits to recreational areas; (c) advise people with gastroenteritis to avoid bathing; and (d) use showers prior to and after bathing.
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A multi-beach study of Staphylococcus aureus, MRSA, and enterococci in seawater and beach sand.
Goodwin, Kelly D; McNay, Melody; Cao, Yiping; Ebentier, Darcy; Madison, Melissa; Griffith, John F
2012-09-01
Incidences of Staphylococcus aureus and methicillin resistant S. aureus (MRSA) have risen worldwide prompting a need to better understand routes of human exposure and whether standard bacterial water quality monitoring practices adequately account for this potential threat. Beach water and sand samples were analyzed during summer months for S. aureus, enterococci, and MRSA at three southern California beaches (Avalon, Doheny, Malibu Surfrider). S. aureus frequently was detected in samples of seawater (59%, n = 328) and beach sand (53%, n = 358). MRSA sometimes was detected in seawater (1.6%, n = 366) and sand (2.7%, n = 366) at relatively low concentrations. Site specific differences were observed, with Avalon Beach presenting the highest concentrations of S. aureus and Malibu Surfrider the lowest in both seawater and sand. S. aureus concentrations in seawater and sand were correlated to each other and to a variety of other parameters. Multiple linear regression on the combined beach data indicated that significant explanatory variables for S. aureus in seawater were S. aureus in sand, water temperature, enterococci in seawater, and the number of swimmers. In sand, S. aureus concentrations were related to S. aureus in seawater, water temperature, enterococci in seawater, and inversely to surf height classification. Only the correlation to water temperature held for individually analyzed beaches and for S. aureus concentrations in both seawater and sand. To provide context for these results, the prevalence of S. aureus in sand was compared to published fomite studies, and results suggested that beach prevalence was similar to that in homes. Published by Elsevier Ltd.
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Scheurer, Marco; Heß, Stefanie; Lüddeke, Frauke; Sacher, Frank; Güde, Hans; Löffler, Herbert; Gallert, Claudia
2015-01-01
Combined sewer systems collect surface runoff as well as wastewater of industrial and domestic origin. During periods of heavy rainfall the capacity of the sewer system is exceeded and the overflow is discharged into receiving waters without any treatment. Consequently, combined sewer overflow (CSO) is considered as a major source of water pollution. This study investigates the effectiveness of a retention soil filter (RSF) for the removal of micropollutants as well as facultative pathogenic and antibiotic resistant bacteria from CSO. The removal of organic group parameters like total organic carbon was excellent and the removal efficiency for micropollutants of the RSF and the wastewater treatment plant (WWTP), which treats wastewater of the same origin during dry and normal weather conditions, was comparable. Compounds of high environmental concern like estrogens or certain pharmaceuticals, e.g. diclofenac, were completely eliminated or removed to a high degree during RSF passage. RSF treatment also reduced the number of E. coli, enterococci and staphylococci by 2.7, 2.2 and 2.4 log-units (median values), respectively. Obviously, some Staphylococcus species can better adapt to the conditions of the RSF than others as a shift of the abundance of the different species was observed when comparing the diversity of staphylococci obtained from the RSF influent and effluent. RSF treatment also decreased the absolute number of antibiotic resistant bacteria. The percentage of antibiotic resistant E. coli and staphylococci isolates also decreased during passage of the RSF, whereas the percentage of resistant enterococci did not change. For E. coli ampicillin and for enterococci and staphylococci erythromycin determined the antibiotic resistance level. The results demonstrate that RSFs can be considered as an adequate treatment option for CSO. The performance for the removal of micropollutants is comparable with a medium sized WWTP with conventional activated sludge treatment. The number of facultative pathogenic and antibiotic resistant bacteria was considerably decreased during RSF passage. However, as RSF effluents still contained antibiotic resistance genes and traces of micropollutants; receiving waters may still be at risk from negative environmental impacts.
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Lankford, Mary G; Collins, Susan; Youngberg, Larry; Rooney, Denise M; Warren, John R; Noskin, Gary A
2006-06-01
Contaminated environmental surfaces, equipment, and health care workers' hands have been linked to outbreaks of infection or colonization because of vancomycin-resistant enterococci (VRE) and Pseudomonas aeruginosa (PSAE). Upholstery, walls, and flooring may enhance bacterial survival, providing infectious reservoirs. Investigate recovery of VRE and PSAE, determine efficacy of disinfection, and evaluate VRE transmission from surfaces. Upholstery, flooring, and wall coverings were inoculated with VRE and PSAE and assessed for recovery at 24 hours, 72 hours, and 7 days. Inoculated surfaces were cleaned utilizing manufacturers' recommendations of natural, commercial, or hospital-approved products and methods, and samples were obtained. To assess potential for transmission, volunteers touched VRE-inoculated surfaces and imprinted palms onto contact-impression plates. Twenty-four hours following inoculation, all surfaces had recovery of VRE; 13 (92.9%) of 14 surfaces had persistent PSAE. After cleaning, VRE was recovered from 7 (50%) surfaces, PSAE from 5 (35.7%) surfaces. After inoculation followed by palmar contact, VRE was recovered from all surfaces touched. Bacteria commonly encountered in hospitals are capable of prolonged survival and may promote cross transmission. Selection of surfaces for health care environments should include product application and complexity of manufacturers' recommendations for disinfection. Recovery of organisms on surfaces and hands emphasizes importance of hand hygiene compliance prior to patient contact.
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Mohammad, Haroon; Younis, Waleed; Chen, Lu; Peters, Christine E; Pogliano, Joe; Pogliano, Kit; Cooper, Bruce; Zhang, Jianan; Mayhoub, Abdelrahman; Oldfield, Eric; Cushman, Mark; Seleem, Mohamed N
2017-03-23
The emergence of antibiotic-resistant bacterial species, such as vancomycin-resistant enterococci (VRE), necessitates the development of new antimicrobials. Here, we investigate the spectrum of antibacterial activity of three phenylthiazole-substituted aminoguanidines. These compounds possess potent activity against VRE, inhibiting growth of clinical isolates at concentrations as low as 0.5 μg/mL. The compounds exerted a rapid bactericidal effect, targeting cell wall synthesis. Transposon mutagenesis suggested three possible targets: YubA, YubB (undecaprenyl diphosphate phosphatase (UPPP)), and YubD. Both UPPP as well as undecaprenyl diphosphate synthase were inhibited by compound 1. YubA and YubD are annotated as transporters and may also be targets because 1 collapsed the proton motive force in membrane vesicles. Using Caenorhabditis elegans, we demonstrate that two compounds (1, 3, at 20 μg/mL) retain potent activity in vivo, significantly reducing the burden of VRE in infected worms. Taken altogether, the results indicate that compounds 1 and 3 warrant further investigation as novel antibacterial agents against drug-resistant enterococci.
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Colorectal cancer specific conditions promote Streptococcus gallolyticus gut colonization.
Aymeric, Laetitia; Donnadieu, Françoise; Mulet, Céline; du Merle, Laurence; Nigro, Giulia; Saffarian, Azadeh; Bérard, Marion; Poyart, Claire; Robine, Sylvie; Regnault, Béatrice; Trieu-Cuot, Patrick; Sansonetti, Philippe J; Dramsi, Shaynoor
2018-01-09
Colonization by Streptococcus gallolyticus subsp. gallolyticus (SGG) is strongly associated with the occurrence of colorectal cancer (CRC). However, the factors leading to its successful colonization are unknown, and whether SGG influences the oncogenic process or benefits from the tumor-prone environment to prevail remains an open question. Here, we elucidate crucial steps that explain how CRC favors SGG colonization. By using mice genetically prone to CRC, we show that SGG colonization is 1,000-fold higher in tumor-bearing mice than in normal mice. This selective advantage occurs at the expense of resident intestinal enterococci. An SGG-specific locus encoding a bacteriocin ("gallocin") is shown to kill enterococci in vitro. Importantly, bile acids strongly enhance this bacteriocin activity in vivo, leading to greater SGG colonization. Constitutive activation of the Wnt pathway, one of the earliest signaling alterations in CRC, and the decreased expression of the bile acid apical transporter gene Slc10A2 , as an effect of the Apc founding mutation, may thereby sustain intestinal colonization by SGG. We conclude that CRC-specific conditions promote SGG colonization of the gut by replacing commensal enterococci in their niche.
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Bushon, R.N.; Likirdopulos, C.A.; Brady, A.M.G.
2009-01-01
Untreated wastewater samples from California, North Carolina, and Ohio were analyzed by the immunomagnetic separation/adenosine triphosphate (IMS/ATP) method and the traditional culture-based method for E. coli and enterococci concentrations. The IMS/ATP method concentrates target bacteria by immunomagnetic separation and then quantifies captured bacteria by measuring bioluminescence induced by release of ATP from the bacterial cells. Results from this method are available within 1 h from the start of sample processing. Significant linear correlations were found between the IMS/ATP results and results from traditional culture-based methods for E. coli and enterococci enumeration for one location in California, two locations in North Carolina, and one location in Ohio (r??values ranged from 0.87 to 0.97). No significant linear relation was found for a second location in California that treats a complex mixture of residential and industrial wastewater. With the exception of one location, IMS/ATP showed promise as a rapid method for the quantification of faecal-indicator organisms in wastewater.
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Byappanahalli, Muruleedhara N; Shively, Dawn A; Nevers, Meredith B; Sadowsky, Michael J; Whitman, Richard L
2003-11-01
The macro-alga Cladophora glomerata is found in streams and lakes worldwide. High concentrations of Escherichia coli and enterococci have been reported in Cladophora along the Lake Michigan shore. The objective of this study was to determine if Cladophora supported growth of these indicator bacteria. Algal leachate readily supported in vitro multiplication of E. coli and enterococci, suggesting that leachates contain necessary growth-promoting substances. Growth was directly related to the concentration of algal leachate. E. coli survived for over 6 months in dried Cladophora stored at 4 degrees C; residual E. coli grew after mat rehydration, reaching a carrying capacity of 8 log CFU g(-1) in 48 h. Results of this study also show that the E. coli strains associated with Cladophora are highly related; in most instances they are genetically different from each other, suggesting that the relationship between E. coli and Cladophora may be casual. These findings indicate that Cladophora provides a suitable environment for indicator bacteria to persist for extended periods and to grow under natural conditions.
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Byappanahalli, M.N.; Shively, D.A.; Nevers, M.B.; Sadowsky, M.J.; Whitman, R.L.
2003-01-01
The macro-alga Cladophora glomerata is found in streams and lakes worldwide. High concentrations of Escherichia coli and enterococci have been reported in Cladophora along the Lake Michigan shore. The objective of this study was to determine if Cladophora supported growth of these indicator bacteria. Algal leachate readily supported in vitro multiplication of E. coli and enterococci, suggesting that leachates contain necessary growth-promoting substances. Growth was directly related to the concentration of algal leachate. E. coli survived for over 6 months in dried Cladophora stored at 4°C; residual E. coli grew after mat rehydration, reaching a carrying capacity of 8 log CFU g-1 in 48 h. Results of this study also show that the E. coli strains associated with Cladophora are highly related; in most instances they are genetically different from each other, suggesting that the relationship between E. coli and Cladophora may be casual. These findings indicate that Cladophora provides a suitable environment for indicator bacteria to persist for extended periods and to grow under natural conditions.
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Enterococcal Infective Endocarditis following Periodontal Disease in Dogs.
Semedo-Lemsaddek, Teresa; Tavares, Marta; São Braz, Berta; Tavares, Luís; Oliveira, Manuela
2016-01-01
In humans, one of the major factors associated with infective endocarditis (IE) is the concurrent presence of periodontal disease (PD). However, in veterinary medicine, the relevance of PD in the evolution of dogs' endocarditis remains poorly understood. In order to try to establish a correlation between mouth-associated Enterococcus spp. and infective endocarditis in dogs, the present study evaluated the presence and diversity of enterococci in the gum and heart of dogs with PD. Samples were collected during necropsy of 32 dogs with PD and visually diagnosed with IE, which died of natural causes or euthanasia. Enterococci were isolated, identified and further characterized by Pulsed-Field Gel Electrophoresis (PFGE); susceptibility to antimicrobial agents and pathogenicity potential was also evaluated. In seven sampled animals, PFGE-patterns, resistance and virulence profiles were found to be identical between mouth and heart enterococci obtained from the same dog, allowing the establishment of an association between enterococcal periodontal disease and endocarditis in dogs. These findings represent a crucial step towards understanding the pathogenesis of PD-driven IE, and constitute a major progress in veterinary medicine.
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White, G. Wesley; Malow, James B.; Zimelis, Victoria M.; Pahlavanzadeh, Hossein; Panwalker, Anand P.; Jackson, George Gee
1979-01-01
The in vitro activities of the newer semisynthetic penicillins azlocillin, mezlocillin, and piperacillin were compared with those of ampicillin and ticarcillin by using 290 clinical laboratory isolates. Piperacillin and mezlocillin were the most active against Escherichia coli, Proteus mirabilis, Klebsiella spp., and Enterobacter spp. When Pseudomonas aeruginosa was tested, piperacillin and azlocillin were more active than either mezlocillin or ticarcillin. Streptococcus pneumoniae and Haemophilus influenzae species were highly susceptible to all of the penicillins tested. Ticarcillin had relatively poor activity against enterococci. The rate of bacterial killing with multiples of the minimal inhibitory concentration of azlocillin, ampicillin, or ticarcillin was tested for E. coli, P. mirabilis, P. aeruginosa, and Klebsiella spp. Increasing concentrations increased the bactericidal effect. The effect of combining azlocillin, ampicillin, or ticarcillin with an aminoglycoside was studied by using both killing curves and checkerboards. The isobolograms constructed from the checkerboards showed a synergistic pattern for the organisms tested, which included E. coli, P. aeruginosa, Klebsiella spp., P. mirabilis, and enterococci. However, the rate of killing was increased by the combination only for P. aeruginosa and enterococci. PMID:111616
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Grabsch, E A; Ghaly-Derias, S; Gao, W; Howden, B P
2008-12-01
The new chromogenic agar chromID VRE (cIDVRE; bioMérieux) was compared with bile esculin agar (BD) containing 6 mg/liter vancomycin for the detection of colonization with vanB-containing vancomycin-resistant enterococci (VRE). At 48 h of incubation, the results obtained with both media were comparable. However, cIDVRE detected significantly more VRE at 24 h (39.3% versus 21.3%, P = 0.003), and its use may facilitate the timely implementation of infection control procedures.
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Little, Christine; Sagoo, Satnam
2009-12-01
This study was undertaken to assess the cleanliness of food preparation areas, cleaning methods used, and the microbiological quality of water used by 1258 mobile food vendors in the UK. Samples collected included potable water (1102), cleaning cloths (801) and environmental swabs from food preparation surfaces (2704). Cleaning cloths were more heavily contaminated with Aerobic Colony Counts, Enterobacteriaceae, Escherichia coli, and Staphylococcus aureus compared to surfaces sampled. Surfaces that were visually dirty, wet, and chopping boards that were plastic or damaged also had high levels of these bacteria. Fifty-four percent of potable water samples were of poor microbiological quality; i.e. contained coliforms, E. coli and/or enterococci. A documented food safety management system was only evident in 40.1% of vendors and cleaning schedules were only used by 43.6%. Deficiencies in the correct use of cleaning materials, such as dilution factors and the minimum contact time for disinfectants, were identified.
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Microbial Survey of Pennsylvania Surface Water Used for Irrigating Produce Crops.
Draper, Audrey D; Doores, Stephanie; Gourama, Hassan; LaBorde, Luke F
2016-06-01
Recent produce-associated foodborne illness outbreaks have been attributed to contaminated irrigation water. This study examined microbial levels in Pennsylvania surface waters used for irrigation, relationships between microbial indicator organisms and water physicochemical characteristics, and the potential use of indicators for predicting the presence of human pathogens. A total of 153 samples taken from surface water sources used for irrigation in southeastern Pennsylvania were collected from 39 farms over a 2-year period. Samples were analyzed for six microbial indicator organisms (aerobic plate count, Enterobacteriaceae, coliform, fecal coliforms, Escherichia coli, and enterococci), two human pathogens (Salmonella and E. coli O157), and seven physical and environmental characteristics (pH, conductivity, turbidity, air and water temperature, and sampling day and 3-day-accumulated precipitation levels). Indicator populations were highly variable and not predicted by water and environmental characteristics. Only five samples were confirmed positive for Salmonella, and no E. coli O157 was detected in any samples. Predictive relationships between microbial indicators and the occurrence of pathogens could therefore not be determined.
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Antibody-Based Therapy for Enterococcal Catheter-Associated Urinary Tract Infections.
Flores-Mireles, Ana L; Walker, Jennifer N; Potretzke, Aaron; Schreiber, Henry L; Pinkner, Jerome S; Bauman, Tyler M; Park, Alyssa M; Desai, Alana; Hultgren, Scott J; Caparon, Michael G
2016-10-25
Gram-positive bacteria in the genus Enterococcus are a frequent cause of catheter-associated urinary tract infection (CAUTI), a disease whose treatment is increasingly challenged by multiantibiotic-resistant strains. We have recently shown that E. faecalis uses the Ebp pilus, a heteropolymeric surface fiber, to bind the host protein fibrinogen as a critical step in CAUTI pathogenesis. Fibrinogen is deposited on catheters due to catheter-induced inflammation and is recognized by the N-terminal domain of EbpA (EbpA NTD ), the Ebp pilus's adhesin. In a murine model, vaccination with EbpA NTD confers significant protection against CAUTI. Here, we explored the mechanism of protection using passive transfer of immune sera to show that antisera blocking EbpA NTD -fibrinogen interactions not only is prophylactic but also can act therapeutically to reduce bacterial titers of an existing infection. Analysis of 55 clinical CAUTI, bloodstream, and gastrointestinal isolates, including E. faecalis, E. faecium, and vancomycin-resistant enterococci (VRE), revealed a diversity of levels of EbpA expression and fibrinogen-binding efficiency in vitro Strikingly, analysis of 10 strains representative of fibrinogen-binding diversity demonstrated that, irrespective of EbpA levels, EbpA NTD antibodies were universally protective. The results indicate that, despite diversity in levels of fibrinogen binding, strategies that target the disruption of EbpA NTD -fibrinogen interactions have considerable promise for treatment of CAUTI. Urinary catheterization is a routine medical procedure, and it has been estimated that 30 million Foley catheters are used annually in the United States. Importantly, placement of a urinary catheter renders the patient susceptible to developing a catheter-associated urinary tract infection, accounting for 1 million cases per year. Additionally, these infections can lead to serious complications, including bloodstream infection and death. Enterococcus strains are a common cause of these infections, and management of enterococcal infections has been more difficult in recent years due to the development of antibiotic resistance and the ability of strains to disseminate, resulting in a major threat in hospital settings. In this study, we developed an antibiotic-sparing treatment that is effective against diverse enterococcal isolates, including vancomycin-resistant enterococci, during catheter-associated urinary tract infections. Copyright © 2016 Flores-Mireles et al.
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Real-time water quality monitoring at a Great Lakes National Park
Byappanahalli, Muruleedhara; Nevers, Meredith; Shively, Dawn; Spoljaric, Ashley; Otto, Christopher
2018-01-01
Quantitative polymerase chain reaction (qPCR) was used by the USEPA to establish new recreational water quality criteria in 2012 using the indicator bacteria enterococci. The application of this method has been limited, but resource managers are interested in more timely monitoring results. In this study, we evaluated the efficacy of qPCR as a rapid, alternative method to the time-consuming membrane filtration (MF) method for monitoring water at select beaches and rivers of Sleeping Bear Dunes National Lakeshore in Empire, MI. Water samples were collected from four locations (Esch Road Beach, Otter Creek, Platte Point Bay, and Platte River outlet) in 2014 and analyzed for culture-based (MF) and non-culture-based (i.e., qPCR) endpoints using Escherichia coli and enterococci bacteria. The MF and qPCR enterococci results were significantly, positively correlated overall (r = 0.686, p < 0.0001, n = 98) and at individual locations as well, except at the Platte River outlet location: Esch Road Beach (r = 0.441, p = 0.031, n = 24), Otter Creek (r = 0.592, p = 0.002, n = 24), and Platte Point Bay (r = 0.571, p = 0.004, n = 24). Similarly, E. coli MF and qPCR results were significantly, positively correlated (r = 0.469, p < 0.0001, n = 95), overall but not at individual locations. Water quality standard exceedances based on enterococci levels by qPCR were lower than by MF method: 3 and 16, respectively. Based on our findings, we conclude that qPCR may be a viable alternative to the culture-based method for monitoring water quality on public lands. Rapid, same-day results are achievable by the qPCR method, which greatly improves protection of the public from water-related illnesses.
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Enterococci in foods--a conundrum for food safety.
Franz, Charles M A P; Stiles, Michael E; Schleifer, Karl Heinz; Holzapfel, Wilhelm H
2003-12-01
Enterococci form part of the lactic acid bacteria (LAB) of importance in foods. They can spoil processed meats but they are on the other hand important for ripening and aroma development of certain traditional cheeses and sausages, especially those produced in the Mediterranean area. Enterococci are also used as human probiotics. However, they are important nosocomial pathogens that cause bacteraemia, endocarditis and other infections. Some strains are resistant to many antibiotics, but antibiotic resistance alone cannot explain the virulence of some of these bacteria. Virulence factors such as adhesins, invasins and haemolysin have been described. The role of enterococci in disease has raised questions on their safety for use in foods or as probiotics. Studies on the incidence of virulence traits among enterococcal strains isolated from food showed that some harbour virulence traits and generally, Enterococcus faecalis harbours more of them than Enterococcus faecium. Regulations in Europe stipulate that safety of probiotic or starter strains is the responsibility of the producer; therefore, each strain intended for such use should be carefully evaluated. For numerous questions, immediate answers are not fully available. It is therefore suggested that when considering an Enterococcus strain for use as a starter or probiotic culture, it is imperative that each particular strain should be carefully evaluated for the presence of all known virulence factors. Ideally, such strains should harbour no virulence determinants and should be sensitive to clinically relevant antibiotics. In general, E. faecium appears to pose a lower risk for use in foods, because these strains generally harbour fewer recognised virulence determinants than E. faecalis. Generally, the incidence of such virulence determinants among E. faecium strains is low, as compared to E. faecalis strains, probably as a result of the presence of pheromone-responsive plasmids.
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Lavilla Lerma, Leyre; Benomar, Nabil; Valenzuela, Antonio Sánchez; Casado Muñoz, María del Carmen; Gálvez, Antonio; Abriouel, Hikmate
2014-12-01
Enterococcus faecalis and Enterococcus faecium isolated from various traditional fermented foods of both animal and vegetable origins have shown multidrug resistance to several antibiotics and tolerance to biocides. Reduced susceptibility was intra and inter-species dependent and was due to specific and unspecific mechanisms such as efflux pumps. EfrAB, a heterodimeric ABC transporter efflux pump, was detected in 100% of multidrug resistant (MDR) E. faecalis strains and only in 12% of MDR E. faecium strains. EfrAB expression was induced by half of minimum inhibitory concentration (MIC) of gentamicin, streptomycin and chloramphenicol. However, expression of efrA and efrB genes was highly dependent on the strain tested and on the antimicrobial used. Our results indicated that 3 mM EDTA highly reduced the MICs of almost all drugs tested. Nevertheless, the higher reductions (>8 folds) were obtained with gentamicin, streptomycin, chlorhexidine and triclosan. Reductions of MICs were correlated with down-regulation of EfrAB expression (10-140 folds) in all three MDR enterococci strains. This is the first report describing the role of EfrAB in the efflux of antibiotics and biocides which reflect also the importance of EfrAB in multidrug resistance in enterococci. EDTA used at low concentration as food preservative could be one of the best choices to prevent spread of multidrug resistant enterococci throughout food chain by decreasing EfrAB expression. EfrAB could be an attractive target not only in enterococci present in food matrix but also those causing infections as well by using EDTA as therapeutic agent in combination with low doses of antibiotics. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Evaluating the importance of faecal sources in human-impacted waters.
Schoen, Mary E; Soller, Jeffrey A; Ashbolt, Nicholas J
2011-04-01
Quantitative microbial risk assessment (QMRA) was used to evaluate the relative contribution of faecal indicators and pathogens when a mixture of human sources impacts a recreational waterbody. The waterbody was assumed to be impacted with a mixture of secondary-treated disinfected municipal wastewater and untreated (or poorly treated) sewage, using Norovirus as the reference pathogen and enterococci as the reference faecal indicator. The contribution made by each source to the total waterbody volume, indicator density, pathogen density, and illness risk was estimated for a number of scenarios that accounted for pathogen and indicator inactivation based on the age of the effluent (source-to-receptor), possible sedimentation of microorganisms, and the addition of a non-pathogenic source of faecal indicators (such as old sediments or an animal population with low occurrence of human-infectious pathogens). The waterbody indicator density was held constant at 35 CFU 100 mL(-1) enterococci to compare results across scenarios. For the combinations evaluated, either the untreated sewage or the non-pathogenic source of faecal indicators dominated the recreational waterbody enterococci density assuming a culture method. In contrast, indicator density assayed by qPCR, pathogen density, and bather gastrointestinal illness risks were largely dominated by secondary disinfected municipal wastewater, with untreated sewage being increasingly less important as the faecal indicator load increased from a non-pathogenic source. The results support the use of a calibrated qPCR total enterococci indicator, compared to a culture-based assay, to index infectious human enteric viruses released in treated human wastewater, and illustrate that the source contributing the majority of risk in a mixture may be overlooked when only assessing faecal indicators by a culture-based method. Published by Elsevier Ltd.
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Talebi, Malihe; Sadeghi, Javad; Rahimi, Fateh; Pourshafie, Mohammad Reza
2015-04-01
Vancomycin-resistant enterococci (VRE) are important nosocomial pathogens and food chain has been considered as an assumed source for dissemination of VRE to human. The presence of VRE isolates from food samples and typing of these isolates with Phene plate, a biochemical fingerprinting method, were investigated. Thirty samples of meat, chicken and cheese were analyzed for VRE during 2010. Antibiotic susceptibility tests and minimum inhibitory concentration (MIC) were also examined. VRE isolates were typed with the Phene plate system (PhPlate), a biochemical fingerprinting method. A total of 70 VRE isolates were obtained and identified as Enterococcus faecium by species-specific PCR. All the isolates carried vanA, while none of them harbored vanB. The VRE isolates included 35, 27, and 8 isolates from meat, chicken and cheese, respectively. Typing with the PhPlate revealed a diversity index of 0.78 for E. faecium, containing 10 common and four single types. The results of antibiotic susceptibility and MIC tests showed an increased resistance to ciprofloxacin, erythromycin, ampicillin and gentamicin, to which, 100%, 100%, 100%, and 95% of VRE isolates were resistant, respectively. Only 5% of the isolates were resistant to chloramphenicol and the MIC of the isolates for vancomycin and teicoplanin was ≥ 256 µg/mL and for gentamicin-resistant isolates it was 1024 µg/mL. Conventional and molecular identification tests exhibited that all the isolates were E. faecium carrying vanA. None of the isolates harbored vanB. The results showed that enterococci are common contaminants in food. Indeed, this study indicates a high prevalence of multidrug-resistant enterococci in food of animal origin in Iran. Isolating some persisting enterococcal isolates revealed that continuous surveillance of antimicrobial resistance in enterococci from food is essential.
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Detection of multiple potentially pathogenic bacteria in Matang mangrove estuaries, Malaysia.
Ghaderpour, Aziz; Mohd Nasori, Khairul Nazrin; Chew, Li Lee; Chong, Ving Ching; Thong, Kwai Lin; Chai, Lay Ching
2014-06-15
The deltaic estuarine system of the Matang Mangrove Forest Reserve of Malaysia is a site where several human settlements and brackish water aquaculture have been established. Here, we evaluated the level of fecal indicator bacteria (FIB) and the presence of potentially pathogenic bacteria in the surface water and sediments. Higher levels of FIB were detected at downstream sampling sites from the fishing village, indicating it as a possible source of anthropogenic pollution to the estuary. Enterococci levels in the estuarine sediments were higher than in the surface water, while total coliforms and E. coli in the estuarine sediments were not detected in all samples. Also, various types of potentially pathogenic bacteria, including Klebsiella pneumoniae, Serratia marcescens and Enterobacter cloacae were isolated. The results indicate that the Matang estuarine system is contaminated with various types of potential human bacterial pathogens which might pose a health risk to the public. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Zanetti, F; De Luca, G; Sacchetti, R; Stampi, S
2007-11-01
The aim of the study was to assess the efficiency of low doses of peracetic acid against viral and bacterial indicators in wastewater and to evaluate if the treatment allows regulatory requirements to be satisfied. A total of 31 samplings were carried out, each involving the collection of secondary effluent and of effluent disinfected with 1.2 or 1.5 mg l(-1) of peracetic acid (contact time 20 minutes). In each sample were measured: somatic coliphages, F-specific RNA bacteriophages, Escherichia coli, total and faecal coliforms, enterococci. Peracetic acid disinfection showed significant differences between the reductions of the microorganisms tested: E. coli showed the highest reduction (1.78 and 2.43 Log respectively with 1.2 and 1.5 mg l(-1) of peracetic acid) and phages the lowest (ranging between 0.52 and 0.60 Log). Only a concentration of 1.5 mg l(-1) of peracetic acid would enable the effluent to be discharged into surface waters in compliance with Italian regulations. The variability of microbial resistance against the peracetic acid disinfection treatment, underlines the importance of assessing disinfection efficiency by using more than one indicator microorganism. The detection of E. coli could be usefully accompanied by tests for more resistant microorganisms such as enterococci or coliphages. In conclusion, peracetic acid can be used for the disinfection of effluents even at low doses, with the advantage of reducing costs and preventing the formation of significant amounts of genotoxic by-products.
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Transport of free and particulate-associated bacteria in karst
NASA Astrophysics Data System (ADS)
Mahler, B. J.; Personné, J.-C.; Lods, G. F.; Drogue, C.
2000-12-01
Karst aquifers, because of their unique hydrogeologic characteristics, are extremely susceptible to contamination by pathogens. Here we present the results of an investigation of contamination of a karst aquifer by fecal indicator bacteria. Two wells intercepting zones with contrasting effective hydraulic conductivities, as determined by pump test, were monitored both during the dry season and in response to a rain event. Samples were also collected from the adjacent ephemeral surface stream, which is known to be impacted by an upstream wastewater treatment plant after rainfall. Whole water and suspended sediment samples were analyzed for fecal coliforms and enterococci. During the dry season, pumping over a 2-day period resulted in increases in concentrations of fecal coliforms to greater than 10,000 CFU/100 ml in the high-conductivity well; enterococci and total suspended solids also increased, to a lesser degree. Toward the end of the pumping period, as much as 50% of the fecal coliforms were associated with suspended sediment. Irrigation of an up-gradient pine plantation with primary-treated wastewater is the probable source of the bacterial contamination. Sampling after a rain event revealed the strong influence of water quality of the adjacent Terrieu Creek on the ground water. Bacterial concentrations in the wells showed a rapid response to increased concentrations in the surface water, with fecal coliform concentrations in ground water ultimately reaching 60,000 CFU/100 ml. Up to 100% of the bacteria in the ground water was associated with suspended sediment at various times. The results of this investigation are evidence of the strong influence of surface water on ground water in karst terrain, including that of irrigation water. The large proportion of bacteria associated with particulates in the ground water has important implications for public health, as bacteria associated with particulates may be more persistent and more difficult to inactivate. The high bacterial concentrations found in both wells, despite the difference in hydraulic conductivity, demonstrates the difficulty of predicting vulnerability of individual wells to bacterial contamination in karst. The extreme temporal variability in bacterial concentrations underscores the importance of event-based monitoring of the bacterial quality of public water supplies in karst.
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Enterococci from artisanal dairy products show high levels of adaptability.
Carlos, Ana Rita; Santos, Jorge; Semedo-Lemsaddek, Teresa; Barreto-Crespo, Maria Teresa; Tenreiro, Rogério
2009-02-15
Enterococci are ubiquitous organisms able to promote both health (fermented food/probiotics) and illness (human/animal infections). Disturbingly, several enterococcal species commonly found in artisanal cheeses, such as Enterococcus faecalis and E. faecium, are being increasingly established as causes of infection, posing a problem for food safety. In this study enterococci from ewe's milk and cheese were compared to clinical and reference strains by growth in media simulating environmental colonization and infection sites: 2YT, BHI, skim milk, urine and rabbit serum at different pHs, NaCl concentrations and temperatures. Growth curves were obtained with Microbiology Workstation Bioscreen C and used to calculate relative indexes--RIs--(based on absorbance, lag phase and specific growth rate) for each strain and environmental condition. Similar or higher RIs were obtained for food strains growing in infection-related environments when compared to clinical ones, revealing their ability to adapt and grow in these conditions. A dendrogram built using Pearson's correlation coefficient and a PCA analysis clustered the strains regardless of their origin or species allocation, suggesting a strain-specific mode of growth and a high environmental adaptability of enterococcal strains. These evidences turn essential the evaluation of strains to be used as starters or probiotics.
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McClintock, Maria K.; Kaznessis, Yiannis N.; Hackel, Benjamin J.
2016-01-01
Vancomycin-resistant Enterococci infections are a significant clinical problem. One proposed solution is to use probiotics, such as lactic acid bacteria, to produce antimicrobial peptides at the site of infection. Enterocin A, a class 2a bacteriocin, exhibits inhibitory activity against E. faecium and E. faecalis, which account for 86% of vancomycin-resistant Enterococci infections. In this study, we aimed to engineer enterocin A mutants with enhanced potency within a lactic acid bacterial production system. Peptide mutants resulting from saturation mutagenesis at sites A24 and T27 were efficiently screened in a 96-well plate assay for inhibition of pathogen growth. Several mutants exhibit increased potency relative to wild-type enterocin A in both liquid- and solid-medium growth assays. In particular, A24P and T27G exhibit enhanced inhibition of multiple strains of E. faecium and E. faecalis, including clinically isolated vancomycin-resistant strains. A24P and T27G enhance killing of E. faecium 8 by 13±3- and 18±4-fold, respectively. The engineered enterocin A/lactic acid bacteria systems offer significant potential to combat antibiotic-resistant infections. PMID:26191783
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McClintock, Maria K; Kaznessis, Yiannis N; Hackel, Benjamin J
2016-02-01
Vancomycin-resistant Enterococci infections are a significant clinical problem. One proposed solution is to use probiotics, such as lactic acid bacteria, to produce antimicrobial peptides at the site of infection. Enterocin A, a class 2a bacteriocin, exhibits inhibitory activity against E. faecium and E. faecalis, which account for 86% of vancomycin-resistant Enterococci infections. In this study, we aimed to engineer enterocin A mutants with enhanced potency within a lactic acid bacterial production system. Peptide mutants resulting from saturation mutagenesis at sites A24 and T27 were efficiently screened in a 96-well plate assay for inhibition of pathogen growth. Several mutants exhibit increased potency relative to wild-type enterocin A in both liquid- and solid-medium growth assays. In particular, A24P and T27G exhibit enhanced inhibition of multiple strains of E. faecium and E. faecalis, including clinically isolated vancomycin-resistant strains. A24P and T27G enhance killing of E. faecium 8 by 13 ± 3- and 18 ± 4-fold, respectively. The engineered enterocin A/lactic acid bacteria systems offer significant potential to combat antibiotic-resistant infections. © 2015 Wiley Periodicals, Inc.
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Silverman, Andrea I; Nelson, Kara L
2016-11-15
Models that predict sunlight inactivation rates of bacteria are valuable tools for predicting the fate of pathogens in recreational waters and designing natural wastewater treatment systems to meet disinfection goals. We developed biological weighting function (BWF)-based numerical models to estimate the endogenous sunlight inactivation rates of E. coli and enterococci. BWF-based models allow the prediction of inactivation rates under a range of environmental conditions that shift the magnitude or spectral distribution of sunlight irradiance (e.g., different times, latitudes, water absorbances, depth). Separate models were developed for laboratory strain bacteria cultured in the laboratory and indigenous organisms concentrated directly from wastewater. Wastewater bacteria were found to be 5-7 times less susceptible to full-spectrum simulated sunlight than the laboratory bacteria, highlighting the importance of conducting experiments with bacteria sourced directly from wastewater. The inactivation rate models fit experimental data well and were successful in predicting the inactivation rates of wastewater E. coli and enterococci measured in clear marine water by researchers from a different laboratory. Additional research is recommended to develop strategies to account for the effects of elevated water pH on predicted inactivation rates.
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Genthner, Fred J; James, Joseph B; Yates, Diane F; Friedman, Stephanie D
2005-07-01
Sources of Enterococcus faecalis isolates from Pensacola Beach, FL. were identified using a library-based approach by applying the statistical method of average similarity to single and composite data sets generated from separate analyses. Data sets included antibiotic resistance analysis (ARA), rep-fingerprints, and fatty acid methyl ester (FAME) profiles. Use of a composite data set composed of ARA and rep-fingerprints, added to the confidence of the identifications. The addition of FAME data to composite data sets did not add to the confidence of identifications. Source identification was performed to better understand risk associated with higher densities of enterococci found in swash zone interstitial water (SZIW) as compared to adjacent bathing water on Pensacola Beach, FL. The "swash zone" is that area of the beach continually washed over by waves. As the potential sources of enterococci were limited in this environment, only two library units, sea gull and human, were constructed. Identification of the beach isolates using a composite data set indicated a sea gull origin. The clonality of the beach isolates suggested that the beach environment selects certain subspecies of E. faecalis.
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[Enterococcal endocarditis: a multicenter study of 76 cases].
Martínez-Marcos, Francisco Javier; Lomas-Cabezas, José Manuel; Hidalgo-Tenorio, Carmen; de la Torre-Lima, Javier; Plata-Ciézar, Antonio; Reguera-Iglesias, José María; Ruiz-Morales, Josefa; Márquez-Solero, Manuel; Gálvez-Acebal, Juan; de Alarcón-González, Arístides
2009-12-01
Although enterococci occupy the third position among microorganisms producing infectious endocarditis (IE) following streptococci and Staphylococcus aureus, few multicenter studies have provided an in-depth analysis of enterococcal IE. Description of the characteristics of 76 cases of enterococcal left-sided infectious endocarditis (LSIE) (native: 59, prosthetic: 17) retrieved from the database of the Cardiovascular Infections Study Group of the Andalusian Society of Infectious Diseases, with emphasis on the comparison with non-enterococcal LSIE. Enterococci were the causal agent in 76 of the 696 episodes of LSIE (11%). Compared with non-enterococcal LSIE, enterococcal LSIE was more commonly seen in patients older than 65 (47.4% vs. 27.6%, P<0.0005), and those with chronic diseases (75% vs. 54.6%, P<0.001), calcified valves (18.6% vs. 10%, P<0.05), and previous urinary (30.3% vs. 2.1%, P<0.00001) or abdominal (10.5% vs. 3.1%, P<0.01) infections, and produced a higher rate of relapses (6.6% vs. 2.3%, P<0.05). Enterococcal LSIE was associated with fewer peripheral vascular or skin manifestations (14.5% vs. 27.1%, P<0.05) and fewer immunological phenomena (10.5% vs. 24%, P<0.01). Among the total of patients with enterococcal LSIE, 36.8% underwent valve surgery during hospitalization. In-hospital mortality was 32.9% for enterococcal LSIE, 9.3% for viridans group streptococci (VGS) LSIE and 48.6% for S. aureus LSIE (enterococci vs VGS: P<0.0001; enterococci vs S. aureus: P=0.02). Enterococcal LSIE patients treated with the combination of a penicillin or vancomycin plus an aminoglycoside (n=60) and those treated with ampicillin plus ceftriaxone (n=6) showed similar in-hospital mortality (26.7% vs 33.3%, P=0.66). High-level resistance to gentamicin was detected in 5 of 38 episodes of enterococcal LSIE (13.1%). Enterococcal LSIE appears in patients with well-defined clinical characteristics, and causes few peripheral vascular or skin manifestations and few immunological phenomena. The relapse rate is higher than in non-enterococcal LSIE. Mortality due to enterococcal LSIE is lower than that of S. aureus LSIE, and much higher than that of VGS LSIE. Mortality due to enterococcal LSIE is similar in patients treated with ampicillin plus ceftriaxone or with a combination of penicillin or vancomycin plus an aminoglycoside. High-level resistance to gentamicin remains uncommon in enterococci causing LSIE.
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Alban, Lis; Ellis-Iversen, Johanne; Andreasen, Margit; Dahl, Jan; Sönksen, Ute W.
2017-01-01
Antibiotic consumption in pigs can be optimized by developing treatment guidelines, which encourage veterinarians to use effective drugs with low probability of developing resistance of importance for human health. In Denmark, treatment guidelines for use in swine production are currently under review at the Danish Veterinary and Food Administration. Use of pleuromutilins in swine has previously been associated with a very low risk for human health. However, recent international data and sporadic findings of novel resistance genes suggest a change of risk. Consequently, a reassessment was undertaken inspired by a risk assessment framework developed by the European Medicines Agency. Livestock-associated methicillin-resistant Staphylococcus aureus of clonal complex 398 (MRSA CC398) and enterococci were identified as relevant hazards. The release assessment showed that the probability of development of pleuromutilin resistance was high in MRSA CC398 (medium uncertainty) and low in enterococci (high uncertainty). A relatively small proportion of Danes has an occupational exposure to pigs, and foodborne transmission was only considered of relevance for enterococci, resulting in an altogether low exposure risk. The human consequences of infection with pleuromutilin-resistant MRSA CC398 or enterococci were assessed as low for the public in general but high for vulnerable groups such as hospitalized and immunocompromised persons. For MRSA CC398, the total risk was estimated as low (low uncertainty), among other due to the current guidelines on prevention of MRSA in place at Danish hospitals, which include screening of patients with daily contact to pigs on admittance. Moreover, MRSA CC398 has a medium human–human transmission potential. For enterococci, the total risk was estimated as low due to low prevalence of resistance, low probability of spread to humans, low virulence, but no screening of hospitalized patients, high ability of acquiring resistance genes, and a limited number of alternative antimicrobials (high uncertainty). This assessment reflects the current situation and should be repeated if pleuromutilin consumption increases substantially, resulting in increased prevalence of mobile, easily transmissible resistance mechanisms. Continuous monitoring of pleuromutilin resistance in selected human pathogens should therefore be considered. This also includes monitoring of linezolid resistance, since resistance mechanisms for pleuromutilins and oxazolidones are often coupled. PMID:28603717
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Water quality and sources of fecal coliform bacteria in the Meduxnekeag River, Houlton, Maine
Culbertson, Charles W.; Huntington, Thomas G.; Stoeckel, Donald M.; Caldwell, James M.; O'Donnell, Cara
2014-01-01
In response to bacterial contamination in the Meduxnekeag River and the desire to manage the watershed to reduce contaminant sources, the Houlton Band of Maliseet Indians (HBMI) and the U.S. Geological Survey began a cooperative effort to establish a baseline of water-quality data that can be used in future studies and to indicate potential sources of nutrient and bacterial contamination. This study was conducted during the summer of 2005 in the Meduxnekeag River Basin near Houlton, Maine. Continuously recorded specific conductance can be a good indicator for water quality. Specific conductance increased downstream from the town of Houlton, between runoff events, and decreased sharply following major runoff events. Collections of discrete samples during the summer of 2005 indicated seasonal positive concentration-discharge relations for total phosphorus and total nitrogen; these results indicate that storm runoff may mobilize and transport these nutrients from the terrestrial environment to the river. Data collected by the HBMI on fecal coliform bacteria indicated that bacterial contamination enters the Meduxnekeag River from multiple paths including tributaries and surface drains (ditches) in developed areas in Houlton, Maine. The Houlton wastewater treatment discharge was not an important source of bacterial contamination. Bacteroidales-based tests for general fecal contamination (Bac32 marker) were predominantly positive in samples that had excessive fecal contamination as indicated by Enterococci density greater than 104 colony-forming units per 100 millilters. Of the 22 samples tested for Bacteroidales-based markers of human-associated fecal contamination (HF134 and HF183), 8 were positive. Of the 22 samples tested for Bacteroidales-based markers of ruminant-associated fecal contamination (CF128 and CF193), 7 were positive. Human fecal contamination was detected consistently at two sites (surface drains in urban areas in the town of Houlton) and occasionally detected at one site (Moose Brook) but was not detected at other sites. Fecal contamination (as indicated by fecal coliform density) apparently is localized under normal flow conditions with the highest levels restricted to drains in urban areas and to a lesser extent B Stream, Pearce Brook, and Big Brook, all tributaries to the main stem of the Meduxnekeag River. Coliphage were enumerated as an alternate indicator of fecal contamination with the intent of typing the virus into host-associated classes (human or ruminant), as was done for Enterococci; however, insufficient coliphage were isolated to provide more than preliminary indications. In spite of low coliphage enumeration, the preliminary results strengthen the conclusion that the Enterococci data correctly indicated the samples that contained human and ruminant fecal contamination. The finding that contamination was in many of the tributaries following storms in mid-July indicates that storm runoff likely carries fecal contaminants to more locations than runoff under lower flow conditions.
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Bactericidal Effects and Mechanism of Action of Olanexidine Gluconate, a New Antiseptic
Iwata, Koushi; Nii, Takuya; Nakata, Hikaru; Tsubotani, Yoshie; Inoue, Yasuhide
2015-01-01
Olanexidine gluconate [1-(3,4-dichlorobenzyl)-5-octylbiguanide gluconate] (development code OPB-2045G) is a new monobiguanide compound with bactericidal activity. In this study, we assessed its spectrum of bactericidal activity and mechanism of action. The minimal bactericidal concentrations of the compound for 30-, 60-, and 180-s exposures were determined with the microdilution method using a neutralizer against 320 bacterial strains from culture collections and clinical isolates. Based on the results, the estimated bactericidal olanexidine concentrations with 180-s exposures were 869 μg/ml for Gram-positive cocci (155 strains), 109 μg/ml for Gram-positive bacilli (29 strains), and 434 μg/ml for Gram-negative bacteria (136 strains). Olanexidine was active against a wide range of bacteria, especially Gram-positive cocci, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci, and had a spectrum of bactericidal activity comparable to that of commercial antiseptics, such as chlorhexidine and povidone-iodine. In vitro experiments exploring its mechanism of action indicated that olanexidine (i) interacts with the bacterial surface molecules, such as lipopolysaccharide and lipoteichoic acid, (ii) disrupts the cell membranes of liposomes, which are artificial bacterial membrane models, (iii) enhances the membrane permeability of Escherichia coli, (iv) disrupts the membrane integrity of S. aureus, and (v) denatures proteins at relatively high concentrations (≥160 μg/ml). These results indicate that olanexidine probably binds to the cell membrane, disrupts membrane integrity, and its bacteriostatic and bactericidal effects are caused by irreversible leakage of intracellular components. At relatively high concentrations, olanexidine aggregates cells by denaturing proteins. This mechanism differs slightly from that of a similar biguanide compound, chlorhexidine. PMID:25987609
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NASA Astrophysics Data System (ADS)
Rajkuberan, Chandrasekaran; Sudha, Kannaiah; Sathishkumar, Gnanasekar; Sivaramakrishnan, Sivaperumal
2015-02-01
The present study aimed to synthesis silver nanoparticles (AgNPs) in a greener route using aqueous latex extract of Calotropis gigantea L. toward biomedical applications. Initially, synthesis of AgNPs was confirmed through UV-Vis spectroscopy which shows the surface plasmonic resonance peak (SPR) at 420 nm. Fourier transform infrared spectroscopy (FTIR) analysis provides clear evidence that protein fractions present in the latex extract act as reducing and stabilizing bio agents. Energy dispersive X-ray (EDAX) spectroscopy confirms the presence of silver as a major constituent element. X-ray diffractograms displays that the synthesized AgNPs were biphasic crystalline nature. Electron microscopic studies such as Field emission scanning electron microscopic (Fe-SEM) and Transmission electron microscope (TEM) reveals that synthesized AgNPs are spherical in shape with the size range between 5 and 30 nm. Further, crude latex aqueous extract and synthesized AgNPs were evaluated against different bacterial pathogens such as Bacillus cereus, Enterococci sp, Shigella sp, Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus aureus and Escherichia coli. Compared to the crude latex aqueous extract, biosynthesized AgNPs exhibits a remarkable antimicrobial activity. Likewise invitro anticancer study manifests the cytotoxicity value of synthesized AgNPs against tested HeLa cells. The output of this study clearly suggesting that biosynthesized AgNPs using latex of C. gigantea can be used as promising nanomaterial for therapeutic application in context with nanodrug formulation.
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Comparative Analysis of the First Complete Enterococcus faecium Genome
Lam, Margaret M. C.; Seemann, Torsten; Bulach, Dieter M.; Gladman, Simon L.; Chen, Honglei; Haring, Volker; Moore, Robert J.; Ballard, Susan; Grayson, M. Lindsay; Johnson, Paul D. R.; Howden, Benjamin P.
2012-01-01
Vancomycin-resistant enterococci (VRE) are one of the leading causes of nosocomial infections in health care facilities around the globe. In particular, infections caused by vancomycin-resistant Enterococcus faecium are becoming increasingly common. Comparative and functional genomic studies of E. faecium isolates have so far been limited owing to the lack of a fully assembled E. faecium genome sequence. Here we address this issue and report the complete 3.0-Mb genome sequence of the multilocus sequence type 17 vancomycin-resistant Enterococcus faecium strain Aus0004, isolated from the bloodstream of a patient in Melbourne, Australia, in 1998. The genome comprises a 2.9-Mb circular chromosome and three circular plasmids. The chromosome harbors putative E. faecium virulence factors such as enterococcal surface protein, hemolysin, and collagen-binding adhesin. Aus0004 has a very large accessory genome (38%) that includes three prophage and two genomic islands absent among 22 other E. faecium genomes. One of the prophage was present as inverted 50-kb repeats that appear to have facilitated a 683-kb chromosomal inversion across the replication terminus, resulting in a striking replichore imbalance. Other distinctive features include 76 insertion sequence elements and a single chromosomal copy of Tn1549 containing the vanB vancomycin resistance element. A complete E. faecium genome will be a useful resource to assist our understanding of this emerging nosocomial pathogen. PMID:22366422
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NASA Astrophysics Data System (ADS)
Hofstra, Nynke; Shahid Iqbal, M.; Majedul Islam, M. M.
2016-04-01
Water contaminated with pathogenic bacteria causing diarrhoea poses a health risk to the population. Worldwide, diarrhoea is the 3rd leading cause of death. A changing climate may increase the concentration of pathogens in surface water. Increased temperature will mostly increase the inactivation of pathogens and therefore decrease the surface water concentration. Increased precipitation may dilute contaminated water, but may also increase the runoff of pathogens into the surface water. Decreased precipitation may have the opposite effect. Moreover, increased chance of extreme precipitation events and increased risk of floods may also increase the runoff of pathogens into the surface water. The net balance of these effects is uncertain. The objective of our study is to quantify the relationship between hydroclimatic variables (surface air and water temperature, precipitation and runoff) and faecal indicator bacteria (FIB, E. coli and Enterococci) in two rivers in Pakistan and Bangladesh. In these countries health problems are large, particularly in annual periods of flood. We studied FIB instead of pathogens, because of the costs associated with pathogen measurements. The relationship between FIB and hydroclimatic variables is expected to be comparable to the relationship between pathogens and hydroclimatic variables. For both regions the FIB concentrations have been monitored for two years between 2013 and 2015 at several points in the rivers. Concentrations of FIB in Kabul (Pakistan) and Betna (Bangladesh) river basins are very high (up to 5.2 log10 cfu/100ml). Due to a broken waste water treatment system of the city of Peshawar, concentrations are higher in Kabul than in the Betna river. All hydroclimatic variables positively correlate with FIB. An unexpected positive relation with temperature can be explained by the fact that temperature and discharge increase at the same time and possibly FIB growth. The positive relation with precipitation and discharge shows that not the dilution, but the increased runoff of FIB is more important. Regression models for each of the measurement locations in Kabul river show that water temperature, discharge and precipitation together explain a large part of the variance (R2 equals 0.72-0.94) for E. coli. The regression model for Betna river comprises water temperature and discharge and for E. coli R2=0.47 and for Enterococci R2=0.49. We can conclude that FIB concentrations increase with increasing temperature and particularly precipitation and discharge. We expect pathogen concentrationss to increase in a similar way and would therefore expect increased health risk due to climate change in Kabul and Betna river basins.
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Stamper, Paul D; Shulder, Stephanie; Bekalo, Pearl; Manandhar, Deepika; Ross, Tracy L; Speser, Sharon; Kingery, Julie; Carroll, Karen C
2010-11-01
A study was performed on 517 surveillance rectal swabs to evaluate a selective and differential chromogenic medium, the BBL CHROMagar VanRE (CVRE), which enables recovery and identification of VanA- and VanB-containing Enterococcus faecium (ENFM) and Enterococcus faecalis (ENFS) isolates. Compared to BBL Enterococcosel agar, a bile-esculin-azide-vancomycin (BEAV) agar, the initial overall sensitivity, specificity, and positive and negative predictive values of CVRE for the detection of vancomycin-resistant ENFM and ENFS were 99.1% and 94.8% and 84.2% and 99.7%, respectively. Among our patient population, more vancomycin-resistant enterococci (VRE) were recovered with CVRE than BEAV.
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Stamper, Paul D.; Shulder, Stephanie; Bekalo, Pearl; Manandhar, Deepika; Ross, Tracy L.; Speser, Sharon; Kingery, Julie; Carroll, Karen C.
2010-01-01
A study was performed on 517 surveillance rectal swabs to evaluate a selective and differential chromogenic medium, the BBL CHROMagar VanRE (CVRE), which enables recovery and identification of VanA- and VanB-containing Enterococcus faecium (ENFM) and Enterococcus faecalis (ENFS) isolates. Compared to BBL Enterococcosel agar, a bile-esculin-azide-vancomycin (BEAV) agar, the initial overall sensitivity, specificity, and positive and negative predictive values of CVRE for the detection of vancomycin-resistant ENFM and ENFS were 99.1% and 94.8% and 84.2% and 99.7%, respectively. Among our patient population, more vancomycin-resistant enterococci (VRE) were recovered with CVRE than BEAV. PMID:20739492
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Vancomycin-Resistant Enterococci: Epidemiology, Infection Prevention, and Control.
Reyes, Katherine; Bardossy, Ana Cecilia; Zervos, Marcus
2016-12-01
Vancomycin-resistant enterococci (VRE) infections have acquired prominence as a leading cause of health care-associated infections. Understanding VRE epidemiology, transmission modes in health care settings, risk factors for colonization, and infection is essential to prevention and control of VRE infections. Infection control strategies are pivotal in management of VRE infections and should be based on patient characteristics, hospital needs, and available resources. Hand hygiene is basic to decrease acquisition of VRE. The effectiveness of surveillance and contact precautions is variable and controversial in endemic settings, but important during VRE outbreak investigations and control. Environmental cleaning, chlorhexidine bathing, and antimicrobial stewardship are vital in VRE prevention and control. Copyright © 2016 Elsevier Inc. All rights reserved.
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Pestel, M; Martin, E; Aucouturier, C; Lemeland, J F; Caron, F
1995-01-01
The effects of 16 different beta-lactam-fosfomycin combinations against 50 bloodstream enterococci were compared by a disk diffusion technique. Cefotaxime exhibited the best interaction. By checkerboard studies, the cefotaxime-fosfomycin combination provided a synergistic bacteriostatic effect against 45 of the 50 isolates (MIC of cefotaxime at which 90% of the isolates were inhibited, >2,048 micrograms/ml; MIC of fosfomycin at which 90% of the isolates were inhibited, 128 micrograms/ml; mean of fractional inhibitory concentration indexes, 0.195). By killing curves, cefotaxime (at 64 micrograms/ml) combined with fosfomycin (at > or = 64 micrograms/ml) was bactericidal against 6 of 10 strains tested. PMID:8619593
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Microorganism Removal in Permeable Pavement Parking Lots ...
Three types of permeable pavements (pervious concrete, permeable interlocking concrete pavers, and porous asphalt) were monitored at the Edison Environmental Center in Edison, New Jersey for indicator organisms such as fecal coliform, enterococci, and E. coli. Results showed that porous asphalt had much lower concentration in monitored infiltrate compared to pervious concrete and permeable interlocking concrete pavers. Concentrations of monitored organisms in infiltrate from porous asphalt were consistently below the bathing water quality standard. Fecal coliform and enterococci exceeded bathing water quality standards more than 72% and 34% of the time for permeable interlocking concrete pavers and pervious concrete, respectively. Purpose is to evaluate the performance of permeable pavement in removing indicator organisms from infiltrating stormwater runoff.
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Postantibiotic Effects of Garenoxacin (BMS-284756) against 12 Gram-Positive or -Negative Organisms
Pankuch, G. A.; Jacobs, M. R.; Appelbaum, P. C.
2003-01-01
Conventional in vitro methods were used to determine the postantibiotic effects (PAEs), sub-MIC effects (SMEs), and postantibiotic sub-MIC effects (PA-SMEs) of garenoxacin for a range of organisms. The mean PAEs of garenoxacin for pneumococci, staphylococci, and enterococci were 0.3 to 2.2 h. For Escherichia coli and Pseudomonas aeruginosa, the PAEs were 0.9 to 1.6 h. The mean PA-SMEs (0.4 times the MIC) for pneumococci, staphylococci, and enterococci were 3.0 to >10 h, 1.8 to >10.7 h, and 5.8 h, respectively, while those for E. coli and P. aeruginosa were 7.6 and 4.4 h, respectively. PMID:12604557
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Sheludchenko, Maxim; Padovan, Anna; Katouli, Mohammad; Stratton, Helen
2016-01-01
Maturation ponds are used in rural and regional areas in Australia to remove the microbial loads of sewage wastewater, however, they have not been studied intensively until present. Using a combination of culture-based methods and quantitative real-time PCR, we assessed microbial removal rates in maturation ponds at four waste stabilization ponds (WSP) with (n = 1) and without (n = 3) baffles in rural and remote communities in Australia. Concentrations of total coliforms, E. coli, enterococci, Campylobacter spp., Salmonella spp., F+ RNA coliphage, adenovirus, Cryptosporidium spp. and Giardia (oo) cysts in maturation ponds were measured at the inlet and outlet. Only the baffled pond demonstrated a significant removal of most of the pathogens tested and therefore was subjected to further study by analyzing E. coli and enterococci concentrations at six points along the baffles over five sampling rounds. Using culture-based methods, we found a decrease in the number of E. coli and enterococci from the initial values of 100,000 CFU per 100 mL in the inlet samples to approximately 1000 CFU per 100 mL in the outlet samples for both bacterial groups. Giardia cysts removal was relatively higher than fecal indicators reduction possibly due to sedimentation. PMID:26729150
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Sheludchenko, Maxim; Padovan, Anna; Katouli, Mohammad; Stratton, Helen
2016-01-02
Maturation ponds are used in rural and regional areas in Australia to remove the microbial loads of sewage wastewater, however, they have not been studied intensively until present. Using a combination of culture-based methods and quantitative real-time PCR, we assessed microbial removal rates in maturation ponds at four waste stabilization ponds (WSP) with (n = 1) and without (n = 3) baffles in rural and remote communities in Australia. Concentrations of total coliforms, E. coli, enterococci, Campylobacter spp., Salmonella spp., F+ RNA coliphage, adenovirus, Cryptosporidium spp. and Giardia (oo) cysts in maturation ponds were measured at the inlet and outlet. Only the baffled pond demonstrated a significant removal of most of the pathogens tested and therefore was subjected to further study by analyzing E. coli and enterococci concentrations at six points along the baffles over five sampling rounds. Using culture-based methods, we found a decrease in the number of E. coli and enterococci from the initial values of 100,000 CFU per 100 mL in the inlet samples to approximately 1000 CFU per 100 mL in the outlet samples for both bacterial groups. Giardia cysts removal was relatively higher than fecal indicators reduction possibly due to sedimentation.
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Sorlini, S; Palazzini, D; Mbawala, A; Ngassoum, M B; Collivignarelli, M C
2013-12-01
Within a cooperation project coordinated by the Association for Rural Cooperation in Africa and Latin America (ACRA) Foundation, water supplies were sampled across the villages of the Logone valley (Chad-Cameroon) mostly from boreholes, open wells, rivers and lakes as well as from some piped water. Microbiological analyses and sanitary inspections were carried out at each source. The microbiological quality was determined by analysis of indicators of faecal contamination, Escherichia coli, Enterococci and Salmonellae, using the membrane filtration method. Sanitary inspections were done using WHO query forms. The assessment confirmed that there are several parameters of health concern in the studied area; bacteria of faecal origins are the most significant. Furthermore, this study demonstrated that Joint Monitoring Programme (JMP) classification and E. coli measurement are not sufficient to state water safety. In fact, in the studied area, JMP defined 'improved sources' may provide unsafe water depending on their structure and sources without E. coli may have Enterococci and Salmonellae. Sanitary inspections also revealed high health risks for some boreholes. In other cases, sources with low sanitary risk and no E. coli were contaminated by Enterococci and Salmonellae. Better management and protection of the sources, hygiene improvement and domestic water treatment before consumption are possible solutions to reduce health risks in the Logone valley.
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2017-01-01
We report a novel molecular assay, based on helicase-dependent amplification (HDA), for the detection of enterococci as markers for fecal pollution in water. This isothermal assay targets the same Enterococcus 23S rRNA gene region as the existing quantitative polymerase chain reaction (qPCR) assays of U.S. Environmental Protection Agency Methods 1611 and 1609 but can be entirely performed on a simple heating block. The developed Enterococcus HDA assay successfully discriminated 15 enterococcal from 15 non-enterococcal reference strains and reliably detected 48 environmental isolates of enterococci. The limit of detection was 25 target copies per reaction, only 3 times higher than that of qPCR. The applicability of the assay was tested on 30 environmental water sample DNA extracts, simulating a gradient of fecal pollution. Despite the isothermal nature of the reaction, the HDA results were consistent with those of the qPCR reference. Given this performance, we conclude that the developed Enterococcus HDA assay has great potential as a qualitative molecular screening method for resource-limited settings when combined with compatible up- and downstream processes. This amplification strategy can pave the way for developing a new generation of rapid, low-cost, and field-deployable molecular diagnostic tools for water quality monitoring. PMID:28541661
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Jayaratne, Padman; Wilson, Clyde; Golding, George R.; Nicholson, Alison M.; Lewis, Delores B.; Hermelijn, Sandra M.
2017-01-01
Emergence of vancomycin-resistant Enterococci (VRE) that first appeared on the stage about three decades ago is now a major concern worldwide as it has globally reached every continent. Our aim was to simply undertake a multinational study to delineate the resistance and virulence genes of clinical isolates of VRE isolates from the Caribbean. We employed both conventional (standard microbiological methods including use of E-test strips, chromogenic agar) and molecular methods (polymerase chain reactions–PCR, pulsed-field gel electrophoresis–PFGE and multilocus sequence typing–MLST) to analyze and characterize 245 Enterococci species and 77 VRE isolates from twelve hospitals from eight countries in the Caribbean. The PCR confirmed and demonstrated the resistance and virulence genes (vanA and esp) among all confirmed VRE isolates. The PFGE delineated clonally related isolates from patients from the same country and other countries in the region. The main sequence types of the VRE isolates from the region included STs 412, 750, 203, 736 and 18, all from the common ancestor for clonal complex 17 (CC17). Despite this common ancestor and association of outbreaks of this lineage clones, there has been no reports of outbreaks of infection by VRE in several hospitals in the Caribbean. PMID:29020115
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Macedo, Ana S; Freitas, Ana R; Abreu, Cristina; Machado, Elisabete; Peixe, Luísa; Sousa, João C; Novais, Carla
2011-01-31
Untreated drinking water is frequently overlooked as a source of antibiotic resistance in developed countries. To gain further insight on this topic, we isolated the indicator bacteria Enterococcus spp. from water samples collected in wells, fountains and natural springs supplying different communities across Portugal, and characterized their antibiotic resistance profile with both phenotypic and genetic approaches. We found various rates of resistance to seven antibiotic families. Over 50% of the isolates were resistant to at least ciprofloxacin, tetracyclines or quinupristin-dalfopristin and 57% were multidrug resistant to ≥3 antibiotics from different families. Multiple enterococcal species (E. faecalis, E. faecium, E. hirae, E. casseliflavus and other Enterococcus spp) from different water samples harbored genes encoding resistance to tetracyclines, erythromycin or gentamicin [tet(M)-46%, tet(L)-14%, tet(S)-5%, erm(B)-22%, aac(6´)-Ie-aph(2″)-12%] and putative virulence factors [gel-28%, asa1-16%]. The present study positions untreated drinking water within the spectrum of ecological niches that may be reservoirs of or vehicles for antibiotic resistant enterococci/genes. These findings are worthy of attention as spread of antibiotic resistant enterococci to humans and animals through water ingestion cannot be dismissed. Copyright © 2010 Elsevier B.V. All rights reserved.
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Futch, J Carrie; Griffin, Dale W; Lipp, Erin K
2010-04-01
To address the issue of human sewage reaching corals along the main reef of the Florida Keys, samples were collected from surface water, groundwater and coral [surface mucopolysaccharide layers (SML)] along a 10 km transect near Key Largo, FL. Samples were collected semi-annually between July 2003 and September 2005 and processed for faecal indicator bacteria (faecal coliform bacteria, enterococci and Clostridium perfringens) and human-specific enteric viruses (enterovirus RNA and adenovirus DNA) by (RT)-nested polymerase chain reaction. Faecal indicator bacteria concentrations were generally higher nearshore and in the coral SML. Enteric viruses were evenly distributed across the transect stations. Adenoviruses were detected in 37 of 75 samples collected (49.3%) whereas enteroviruses were only found in 8 of 75 samples (10.7%). Both viruses were detected twice as frequently in coral compared with surface water or groundwater. Offshore, viruses were most likely to be found in groundwater, especially during the wet summer season. These data suggest that polluted groundwater may be moving to the outer reef environment in the Florida Keys.
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Futch, J. Carrie; Griffin, Dale W.; Lipp, Erin K.
2010-01-01
To address the issue of human sewage reaching corals along the main reef of the Florida Keys, samples were collected from surface water, groundwater and coral [surface mucopolysaccharide layers (SML)] along a 10 km transect near Key Largo, FL. Samples were collected semi-annually between July 2003 and September 2005 and processed for faecal indicator bacteria (faecal coliform bacteria, enterococci and Clostridium perfringens) and human-specific enteric viruses (enterovirus RNA and adenovirus DNA) by (RT)-nested polymerase chain reaction. Faecal indicator bacteria concentrations were generally higher nearshore and in the coral SML. Enteric viruses were evenly distributed across the transect stations. Adenoviruses were detected in 37 of 75 samples collected (49.3%) whereas enteroviruses were only found in 8 of 75 samples (10.7%). Both viruses were detected twice as frequently in coral compared with surface water or groundwater. Offshore, viruses were most likely to be found in groundwater, especially during the wet summer season. These data suggest that polluted groundwater may be moving to the outer reef environment in the Florida Keys.
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Fass, R J
1991-01-01
The in vitro activity of RP 59500, a semisynthetic pristinamycin, was compared with the activities of vancomycin, oxacillin, ampicillin, gentamicin, ciprofloxacin, and rifampin against five Staphylococcus species, five Streptococcus species, and four Enterococcus species. For staphylococci, MICs were 0.13 to 1 microgram/ml and the MICs for 90% of the strains tested (MIC90s) were 0.13 to 0.5 microgram/ml; there were no differences between oxacillin-susceptible and -resistant strains. For streptococci, MICs were 0.03 to 4 micrograms/ml and MIC90s were 0.25 to 2 micrograms/ml; viridans group streptococci were the least susceptible streptococci. For enterococci, MICs were 0.25 to 32 micrograms/ml and MIC90s were 2 to 4 micrograms/ml; Enterococcus faecalis was the least susceptible. Vancomycin was the only comparative drug with consistent activity against all species of gram-positive cocci. With RP 59500, raising the inoculum 100-fold, lowering the pH of cation-adjusted Mueller-Hinton broth to 5.5, or omitting cation supplementation had little effect on MICs, but 50% serum increased MICs 2 to 4 dilution steps. The differences between MBCs and MICs were greater for staphylococci and enterococci than for streptococci. Time-kill studies with 24 strains indicated that RP 59500 concentrations 2-, 4-, and 16-fold greater than the MICs usually killed bacteria of each species at similar rates; reductions in CFU per milliliter were less than those observed with oxacillin or vancomycin against staphylococci and less than those observed with ampicillin against enterococci. RP 59500 antagonized the bactericidal activities of oxacillin and gentamicin against Staphylococcus aureus ATCC 29213 and that of ampicillin against E. faecalis ATCC 29212. Against the latter, combination with gentamicin was indifferent. RP 59500 has a broad spectrum of in vitro activity against gram-positive cocci; combining it with other drugs is not advantageous. PMID:1903912
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Brinkmeyer, Robin; Amon, Rainer M W; Schwarz, John R; Saxton, Tara; Roberts, Dustin; Harrison, Sarah; Ellis, Nicholas; Fox, Jessica; DiGuardi, Katherine; Hochman, Mona; Duan, Shuiwang; Stein, Ron; Elliott, Catherine
2015-01-01
The purpose of this research was to determine if Escherichia coli and enterococci in streambed and bank sediments from two urban bayous, Buffalo Bayou and White Oak Bayou, in Houston, TX, USA are a significant source of the chronically high levels of these bacteria in the overlying water. The watersheds of the bayous lie within highly urbanized areas of Greater Houston and there is primary recreational contact with the public. Extensive sampling of the watersheds was conducted from 2008 to 2010. Both fecal indicator bacteria were found at ≥ 10(4)MPNgdry wt.(-1) concentrations in the upper 1cm of sediment cores with declines by orders of magnitude at 15 and 30 cm sediment horizons and in some cases 60 cm, but, nonetheless, indicating that they can remain viable even at depth. No interannual variation was observed. And, there was no correlation with percent organic matter, however there was moderate correlation (R(2)=0.12; p=0.001) of E. coli with sediment moisture. In sediments, most E. coli and enterococci in Buffalo Bayou (76%) and White Oak Bayou (87.5%) were associated with fine sand grains (60 to 250 μm). In the water column, E. coli was associated, in roughly equal percentages, with particle sizes <10, 10-25, 25-63, and ≥ 63 μm (21.9, 25.6, 30.4, and 32.9%, respectively). Enterococci were mostly attached to particle sizes in the ranges of 10-25μm (36.0%) and 25-63 μm (31.1%) as well as ≥ 63 μm (37.7%) (p=0.0001). Fingerprinting of E. coli isolates from both bayous with Rep-PCR and the BOX A1R primer was used to demonstrate translocation of sediments from the upper to lower watersheds. Copyright © 2014 Elsevier B.V. All rights reserved.
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Gousia, Panagiota; Economou, Vangelis; Bozidis, Petros; Papadopoulou, Chrissanthy
2015-03-01
In the present study, 500 raw beef, pork, and chicken meat samples and 100 pooled egg samples were analyzed for the presence of vancomycin-resistant enterococci, vancomycin-resistance phenotypes, and resistance genes. Of 141 isolates of enterococci, 88 strains of Enterococcus faecium and 53 strains of E. faecalis were identified. The most prevalent species was E. faecium. Resistance to ampicillin (n = 93, 66%), ciprofloxacin (n = 74, 52.5%), erythromycin (n = 73, 51.8%), penicillin (n = 59, 41.8%) and tetracycline (n = 52, 36.9%) was observed, while 53.2% (n = 75) of the isolates were multiresistant and 15.6% (n = 22) were susceptible to all antibiotics. Resistance to vancomycin was exhibited in 34.1% (n = 30) of the E. faecium isolates (n = 88) and 1.9% (n = 1) of the E. faecalis isolates (n = 53) using the disc-diffusion test and the E-test. All isolates were tested for vanA and vanB using real-time polymerase chain reaction (PCR) and multiplex PCR, and for vanC, vanD, vanE, vanG genes using multiplex PCR only. Among E. faecalis isolates, no resistance genes were identified. Among the E. faecium isolates, 28 carried the vanA gene when tested by multiplex PCR and 29 when tested with real-time PCR. No isolate carrying the vanC, vanD, vanE, or vanG genes was identified. Melting-curve analysis of the positive real-time PCR E. faecium isolates showed that 22 isolates carried the vanA gene only, 2 isolates the vanB2,3 genes only, and seven isolates carried both the vanA and vanB2,3 genes. Enterococci should be considered a significant zoonotic pathogen and a possible reservoir of genes encoding resistance potentially transferred to other bacterial species.
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Hahn, G
1981-11-01
In accordance with previous papers published within a series of publications which describe the results obtained from the Central Laboratory for Streptococcal Research in Kiel (1. Survey, 2. Mastitis-Streptococci) the group of Enterococci is discussed herewith. On the basis of more than 6000 strains which are stored in our databank including all biological characteristics, the distribution of the cultural, biochemical and serological parameters is listed in percentages, and the usefulness and reliability for the identification of the enterococcal group and also the differentiation of particular species is discussed. The results are tabulated for every single species and additionally, for serologic-positive and negative strains. For example, it can be shown that a third of all Str. faecium strains are motile, that lack of growth at 45 degrees C varies between 1.1% and 31.3% and that lack of serological reaction with group D-serum between 0.9% and 70%. In a comprehensive table and flow diagram these figures result in a proposal for a simple but sufficient identification procedure on different stages (enterococci, faecalis- or faecium-group, single species) depending on the individual requirements. With regard to the incidence of enterococci in man and animals, which was presented in the first paper, the organ sources of the different species are compared now. Apart from some interesting findings it can be stated that a typical predominance of the faecalis and faecium-group resp. in man or animals cannot be confirmed. But there seems to be a relation between the species and the organ source. For example, in humans the faecium-group predominates in the respiratory tract, but in the urogenital tract the presence of Str. faecalis is seven times higher than the faecium-group. The above results may also be of interest for ecological reasons and may be important for the pathogenesis and epidemiology of this streptococcal group.
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Karaolia, Popi; Michael, Irene; García-Fernández, Irene; Agüera, Ana; Malato, Sixto; Fernández-Ibáñez, Pilar; Fatta-Kassinos, Despo
2014-01-15
The presence of pathogenic antibiotic-resistant bacteria in aquatic environments has become a health threat in the last few years. Their presence has increased due to the presence of antibiotics in wastewater effluents, which are not efficiently removed by conventional wastewater treatments. As a result there is a need to study the possible ways of removal of the mixtures of antibiotics present in wastewater effluents and the antibiotic-resistant bacteria, which may also spread the antibiotic resistance genes to other bacterial populations. In this study the degradation of a mixture of antibiotics i.e. sulfamethoxazole and clarithromycin, the disinfection of total enterococci and the removal of those resistant to: a) sulfamethoxazole, b) clarithromycin and c) to both antibiotics have been examined, along with the toxicity of the whole effluent mixture after treatment to the luminescent aquatic bacterium Vibrio fischeri. Solar Fenton treatment (natural solar driven oxidation) using Fenton reagent doses of 50 mg L(-1) of hydrogen peroxide and 5 mg L(-1) of Fe(3+) in a pilot-scale compound parabolic collector plant was used to examine the disinfection and antibiotic resistance removal efficiency in different aqueous matrices, namely distilled water, simulated and real wastewater effluents. There was a faster complete removal of enterococci and of antibiotics in all aqueous matrices by applying solar Fenton when compared to photolytic treatment of the matrices. Sulfamethoxazole was more efficiently degraded than clarithromycin in all three aqueous matrices (95% removal of sulfamethoxazole and 70% removal of clarithromycin in real wastewater). The antibiotic resistance of enterococci towards both antibiotics exhibited a 5-log reduction with solar Fenton in real wastewater effluent. Also after solar Fenton treatment, there were 10 times more antibiotic-resistant enterococci in the presence of sulfamethoxazole than in the presence of clarithromycin. Finally, the toxicity of the treated wastewater to V. fischeri remained very low throughout the treatment time. © 2013.
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Antimicrobial resistance and virulence genes in enterococci from wild game meat in Spain.
Guerrero-Ramos, Emilia; Cordero, Jorge; Molina-González, Diana; Poeta, Patrícia; Igrejas, Gilberto; Alonso-Calleja, Carlos; Capita, Rosa
2016-02-01
A total of 55 enterococci (45 Enterococcus faecium, 7 Enterococcus faecalis, and three Enterococcus durans) isolated from the meat of wild game animals (roe deer, boar, rabbit, pheasant, and pigeon) in North-Western Spain were tested for susceptibility to 14 antimicrobials by the disc diffusion method. All strains showed a multi-resistant phenotype (resistance to between three and 10 antimicrobials). The strains exhibited high percentages of resistance to erythromycin (89.1%), tetracycline (67.3%), ciprofloxacin (92.7%), nitrofurantoin (67.3%), and quinupristin-dalfopristin (81.8%). The lowest values (9.1%) were observed for high-level resistance to gentamicin, kanamycin, and streptomycin. The average number of resistances per strain was 5.8 for E. faecium isolates, 7.9 for E. faecalis, and 5.7 for E. durans. Genes encoding antimicrobial resistance and virulence were studied by polymerase chain reaction. A total of 15 (57.7%) of the 26 vancomycin-resistant isolates harboured the vanA gene. Other resistance genes detected included vanB, erm(B) and/or erm(C), tet(L) and/or tet(M), acc(6')-aph(2″), and aph(3')-IIIa in strains resistant to vancomycin, erythromycin, tetracycline, gentamicin, and kanamycin, respectively. Specific genes of the Tn5397 transposon were detected in 54.8% of the tet(M)-positive enterococci. Nine virulence factors (gelE, agg, ace, cpd, frs, esp, hyl, efaAfs and efaAfm) were studied. All virulence genes, with the exception of the frs gene, were found to be present in the enterococcal isolates. At least one virulence gene was detected in 20.0% of E. faecium, 71.4% of E. faecalis and 33.3% of E. durans isolates, with ace and cpd being the most frequently detected genes (6 isolates each). This suggests that wild game meat might play a role in the spreading through the food chain of enterococci with antimicrobial resistance and virulence determinants to humans. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Ryu, Hodon; Henson, Michael; Elk, Michael; Toledo-Hernandez, Carlos; Griffith, John; Blackwood, Denene; Noble, Rachel; Gourmelon, Michèle; Glassmeyer, Susan
2013-01-01
The detection of environmental enterococci has been determined primarily by using culture-based techniques that might exclude some enterococcal species as well as those that are nonculturable. To address this, the relative abundances of enterococci were examined by challenging fecal and water samples against a currently available genus-specific assay (Entero1). To determine the diversity of enterococcal species, 16S rRNA gene-based group-specific quantitative PCR (qPCR) assays were developed and evaluated against eight of the most common environmental enterococcal species. Partial 16S rRNA gene sequences of 439 presumptive environmental enterococcal strains were analyzed to study further the diversity of enterococci and to confirm the specificities of group-specific assays. The group-specific qPCR assays showed relatively high amplification rates with targeted species (>98%), although some assays cross-amplified with nontargeted species (1.3 to 6.5%). The results with the group-specific assays also showed that different enterococcal species co-occurred in most fecal samples. The most abundant enterococci in water and fecal samples were Enterococcus faecalis and Enterococcus faecium, although we identified more water isolates as Enterococcus casseliflavus than as any of the other species. The prevalence of the Entero1 marker was in agreement with the combined number of positive signals determined by the group-specific assays in most fecal samples, except in gull feces. On the other hand, the number of group-specific assay signals was lower in all water samples tested, suggesting that other enterococcal species are present in these samples. While the results highlight the value of genus- and group-specific assays for detecting the major enterococcal groups in environmental water samples, additional studies are needed to determine further the diversity, distributions, and relative abundances of all enterococcal species found in water. PMID:23087032
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Lorah, Michelle M.; Soeder, Daniel J.; Teunis, Jessica A.
2010-01-01
The U.S. Geological Survey, in cooperation with the government of Charles County, Maryland, and the Port Tobacco River Conservancy, Inc., conducted a water-quality reconnaissance and sampling investigation of the Port Tobacco River and Nanjemoy Creek watersheds in Charles County during October 2007 and June-August 2008. Samples were collected and analyzed for major ions, nutrients, organic wastewater compounds, and other selected constituents from 17 surface-water sites and 11 well sites (5 of which were screened in streambed sediments to obtain porewater samples). Most of the surface-water sites were relatively widely spaced throughout the Port Tobacco River and Nanjemoy Creek watersheds, although the well sites and some associated surface-water sites were concentrated in one residential community along the Port Tobacco River that has domestic septic systems. Sampling for enterococci bacteria was conducted by the Port Tobacco River Conservancy, Inc., at each site to coordinate with the sampling for chemical constituents. The purpose of the coordinated sampling was to determine correlations between historically high, in-stream bacteria counts and human wastewater inputs. Chemical data for the groundwater, porewater, and surface-water samples are presented in this report.
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Coastal microbial quality of surface sediments in different environments along the Italian coast.
Chiaretti, G; Onorati, F; Borrello, P; Orasi, A; Mugnai, C
2014-09-20
In order to improve sediment handling following dredging operations, this study aims to statistically derive ranges of distribution for certain microbiological parameters, according to four environmental types inspired by Italian legislation on seaports: ports of international/national importance, ports of regional importance, port channels in brackish environments, and marine coastal areas. A national database was developed using microbiological data from technical reports available at the Italian Ministry of Environment and National Institute of Environmental Protection and Research (ISPRA) for the period 1990-2008. The parameters considered were total coliform bacteria, faecal coliform bacteria, Escherichia coli, enterococci, sulfite-reducing clostridia (SRC), total bacterial counts at 22 °C and at 37 °C, and fungi. The data were statistically analyzed: (1) to verify the correspondence with the identified environmental types and rank them according to the concentration gradient and (2) to describe the data distribution in order to obtain reference ranges typical for each parameter/environmental type. The four environmental types considered were clearly different for enterococci, SRC, and fungi, highlighting a correspondence with Italian legislation. For the remaining parameters, at least two environmental types were merged. In general, the less contaminated environments were small ports and relatively unimpacted coastal areas. The ranges defined for relatively clean coastal areas can be considered a target for other areas both from an environmental point of view and for the sediment management implications. These values could be used as a comparison in environmental surveys addressing marine or brackish sediment handling and may represent a future line of evidence for the assessment of overall sediment quality.
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Incidence of somatic and F+ coliphage in Great Lake Basin recreational waters.
Wanjugi, Pauline; Sivaganesan, Mano; Korajkic, Asja; McMinn, Brian; Kelty, Catherine A; Rhodes, Eric; Cyterski, Mike; Zepp, Richard; Oshima, Kevin; Stachler, Elyse; Kinzelman, Julie; Kurdas, Stephan R; Citriglia, Mark; Hsu, Fu-Chih; Shanks, Orin C
2018-04-25
There is a growing interest for the use of coliphage as an alternative indicator to assess fecal pollution in recreational waters. Coliphage are a group of viruses that infect Escherichia coli and are considered as potential surrogates to infer the likely presence of enteric viral pathogens. We report the use of a dead-end hollow fiber ultrafiltration single agar layer method to enumerate F+ and somatic coliphage from surface waters collected from three Great Lake areas. At each location, three sites (two beaches; one river) were sampled five days a week over the 2015 beach season (n = 609 total samples). In addition, culturable E. coli and enterococci concentrations, as well as 16 water quality and recreational area parameters were assessed such as rainfall, turbidity, dissolved oxygen, pH, and ultra violet absorbance. Overall, somatic coliphage levels ranged from non-detectable to 4.39 log 10 plaque forming units per liter and were consistently higher compared to F+ (non-detectable to 3.15 log 10 PFU/L), regardless of sampling site. Coliphage concentrations weakly correlated with cultivated fecal indicator bacteria levels (E. coli and enterococci) at 75% of beach sites tested in study (r = 0.28 to 0.40). In addition, ultraviolet light absorption and water temperature were closely associated with coliphage concentrations, but not fecal indicator bacteria levels suggesting different persistence trends in Great Lake waters between indicator types (bacteria versus virus). Finally, implications for coliphage water quality management and future research directions are discussed. Copyright © 2018. Published by Elsevier Ltd.
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Delille, D; Gleizon, F
2003-09-01
Untreated sewage has been released from Port-aux Français station, Kerguelen Island, into the Southern Ocean for more than 50 years. We investigated the spatial distribution of faecal bacteria indicators during a one-year survey conducted in seawater off Morbihan Bay near the French permanent station of the Kerguelen Island (49 degrees 21(')S, 70 degrees 30(')E). Seawater samples were taken bimonthly from nine stations evenly distributed around the sewage outfalls of the station. Escherichia coli and enterococci were estimated using specific microplates (Miniaturized method for the enumeration of E. coli or enterococci in surface and waste waters, "MU/EC or MU/SF methods", BIO-RAD( Copyright)). In order to evaluate the role of seasonal changes of environmental parameters on the survival of enteric bacteria, total and saprophytic bacterial abundances were also estimated in all seawater samples. High densities of faecal bacteria (maximum 10(4) cells 100 ml(-1)) were found in seawater surrounding the sewage outfall. However, enteric bacterial counts decreased rapidly with increasing distance from the outfall. In all samples collected further than 2 km from the outfall, the bacterial indicators were absent or present in small numbers (<10 cells 100 ml(-1)). Faecal coliforms were not detected in samples collected at pristine sites located 10 km from Port-aux-Français. Despite these low contamination levels, faecal bacteria were always detected in the vicinity of the sewage outfall during the seasonal survey. The concentration of faecal bacteria may be related to the number of people inhabiting the station.
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Vancomycin-Resistant Enterococci (VRE):Overview
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Toru, Milkiyas; Beyene, Getnet; Kassa, Tesfaye; Gizachew, Zeleke; Howe, Rawleigh; Yeshitila, Biruk
2018-05-08
This study was done to determine the prevalence and phenotypic characterization of Enterococcus species isolated from clinical samples of pediatric patients in Jimma University Specialized Hospital, Southwest Ethiopia. The overall prevalence of Enterococci species was 5.5% (22/403). Five (22.7%) of Enterococci species were vancomycin resistant. Haemolysin, gelatinase and biofilm production was seen among 45.5, 68.2 and 77.3% of isolates respectively. The overall rate of antibiotic resistance was 95.5% (21/22). High resistance was observed against norfloxacin (87.5%), and tetracycline (77.3%). Whereas, low resistance (36.5%) was observed against ciprofloxacin and eighteen (80.8%) of the isolates were multi-drug resistant.
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Vancomycin-Resistant Enterococci in Healthcare Settings
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Vancomycin-resistant enterococci - hospital
Arias CA, Murray BE. Enterococcus species, Streptococcus gallolyticus group, and Leuconostoc species. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious ...
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Bargossi, Eleonora; Tabanelli, Giulia; Montanari, Chiara; Lanciotti, Rosalba; Gatto, Veronica; Gardini, Fausto; Torriani, Sandra
2015-01-01
The ability to accumulate tyramine and 2-phenylethylamine by two strains of Enterococcus faecalis and two strains Enterococcus faecium was evaluated in two cultural media added or not with tyrosine. All the enterococcal strains possessed a tyrosine decarboxylase (tyrDC) which determined tyramine accumulation in all the conditions tested, independently on the addition of high concentration of free tyrosine. Enterococci differed in rate and level of biogenic amines accumulation. E. faecalis EF37 and E. faecium FC12 produced tyramine in high amount since the exponential growth phase, while 2-phenylethylamine was accumulated when tyrosine was depleted. E. faecium FC12 and E. faecalis ATCC 29212 showed a slower tyraminogenic activity which took place mainly in the stationary phase up to 72 h of incubation. Moreover, E. faecalis ATCC 29212 produced 2-phenylethylamine only in the media without tyrosine added. In BHI added or not with tyrosine the tyrDC gene expression level differed considerably depending on the strains and the growth phase. In particular, the tyrDC gene expression was high during the exponential phase in rich medium for all the strains and subsequently decreased except for E. faecium FC12. Even if tyrDC presence is common among enterococci, this study underlines the extremely variable decarboxylating potential of strains belonging to the same species, suggesting strain-dependent implications in food safety.
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Shelton, Jessica M; Kim, Lavane; Fang, Jiasong; Ray, Chittaranjan; Yan, Tao
2011-10-15
This study investigated the flux stability of select chemical and biological sewage markers, including caffeine, total nitrogen (TN), total suspended solids (TSS), E. coli, and enterococci, and their suitability in assessing the severity of rainfall-derived infiltration and inflow (RDII) in a residential sewershed. To quantify and compare marker flux stability, concentrations of the candidate markers in two dry-weather periods were determined and the one-day lag autocorrelation coefficients (r) of their mass fluxes were calculated. TN (r = 0.82-0.88) exhibited higher and more consistent flux stability than TSS (r = 0.49-0.82), caffeine (r = 0.56-0.58), E. coli (r = 0.36-0.87), and enterococci (by culture; r = 0.40-0.52), all of which except enterococci by qPCR (r = -0.10-0.21) showed significant autocorrelation. Sewage flows and marker concentrations were also monitored in two wet-weather periods, and the severity of RDII (R(RDII)) were calculated using either flow measurements or marker concentrations independently. Corresponding to its outstanding flux stability, R(RDII) values estimated by TN predicted all severe RDII instances and gave the highest and most consistent correlation (r = 0.74-0.78) among the different sewage markers. Overall, the study illustrated the feasibility of using the flux stability of sewage markers in assessing the severity of RDII and thereby deterioration levels in sewer systems.
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Cleaning Hospital Room Surfaces to Prevent Health Care-Associated Infections: A Technical Brief.
Han, Jennifer H; Sullivan, Nancy; Leas, Brian F; Pegues, David A; Kaczmarek, Janice L; Umscheid, Craig A
2015-10-20
The cleaning of hard surfaces in hospital rooms is critical for reducing health care-associated infections. This review describes the evidence examining current methods of cleaning, disinfecting, and monitoring cleanliness of patient rooms, as well as contextual factors that may affect implementation and effectiveness. Key informants were interviewed, and a systematic search for publications since 1990 was done with the use of several bibliographic and gray literature resources. Studies examining surface contamination, colonization, or infection with Clostridium difficile, methicillin-resistant Staphylococcus aureus, or vancomycin-resistant enterococci were included. Eighty studies were identified-76 primary studies and 4 systematic reviews. Forty-nine studies examined cleaning methods, 14 evaluated monitoring strategies, and 17 addressed challenges or facilitators to implementation. Only 5 studies were randomized, controlled trials, and surface contamination was the most commonly assessed outcome. Comparative effectiveness studies of disinfecting methods and monitoring strategies were uncommon. Future research should evaluate and compare newly emerging strategies, such as self-disinfecting coatings for disinfecting and adenosine triphosphate and ultraviolet/fluorescent surface markers for monitoring. Studies should also assess patient-centered outcomes, such as infection, when possible. Other challenges include identifying high-touch surfaces that confer the greatest risk for pathogen transmission; developing standard thresholds for defining cleanliness; and using methods to adjust for confounders, such as hand hygiene, when examining the effect of disinfecting methods.
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Cleaning Hospital Room Surfaces to Prevent Health Care–Associated Infections
Han, Jennifer H.; Sullivan, Nancy; Leas, Brian F.; Pegues, David A.; Kaczmarek, Janice L.; Umscheid, Craig A.
2015-01-01
The cleaning of hard surfaces in hospital rooms is critical for reducing health care–associated infections. This review describes the evidence examining current methods of cleaning, disinfecting, and monitoring cleanliness of patient rooms, as well as contextual factors that may affect implementation and effectiveness. Key informants were interviewed, and a systematic search for publications since 1990 was done with the use of several bibliographic and gray literature resources. Studies examining surface contamination, colonization, or infection with Clostridium difficile, methicillin-resistant Staphylococcus aureus, or vancomycinresistant enterococci were included. Eighty studies were identified—76 primary studies and 4 systematic reviews. Forty-nine studies examined cleaning methods, 14 evaluated monitoring strategies, and 17 addressed challenges or facilitators to implementation. Only 5 studies were randomized, controlled trials, and surface contamination was the most commonly assessed outcome. Comparative effectiveness studies of disinfecting methods and monitoring strategies were uncommon. Future research should evaluate and compare newly emerging strategies, such as self-disinfecting coatings for disinfecting and adenosine triphosphate and ultraviolet/fluorescent surface markers for monitoring. Studies should also assess patient-centered outcomes, such as infection, when possible. Other challenges include identifying high-touch surfaces that confer the greatest risk for pathogen transmission; developing standard thresholds for defining cleanliness; and using methods to adjust for confounders, such as hand hygiene, when examining the effect of disinfecting methods. PMID:26258903
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Firmesse, Olivier; Rabot, Sylvie; Bermúdez-Humarán, Luis G; Corthier, Gérard; Furet, Jean-Pierre
2007-11-01
Enterococci are natural inhabitants of the human gastrointestinal tract and the main Gram-positive and facultative anaerobic cocci recovered in human faeces. They are also present in a variety of fermented dairy and meat products, and some rare isolates are responsible for severe infections such as endocarditis and meningitis. The aim of the present study was to evaluate the effect of Camembert cheese consumption by healthy human volunteers on the faecal enterococcal population. A highly specific real-time quantitative PCR approach was designed and used to type enterococcal species in human faeces. Two species were found, Enterococcus faecalis and Enterococcus faecium, and only the Enterococcus faecalis population was significantly enhanced after Camembert cheese consumption, whereas Escherichia coli population and the dominant microbiota remained unaffected throughout the trial.
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Brumfitt, W; Salton, M R J; Hamilton-Miller, J M T
2002-11-01
We have sought ways to circumvent resistance, by combining nisin with other antibiotics known to target bacterial cell wall biosynthesis. Twenty strains each of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) were tested in vitro by standardized methods against nisin alone and combined with bacitracin, ramoplanin and chloramphenicol. Ramoplanin was the most potent compound, and bacitracin had the least activity. Two-way synergy was observed with nisin and ramoplanin. However, chloramphenicol was clearly antagonistic to the activity of nisin. Observations of synergy between nisin and ramoplanin against MRSA and VRE offer a promising approach to the concept of combining nisin with inhibitors of cell wall peptidoglycan. Further investigations are needed in order to develop this approach as a clinical possibility.
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Thickman, Jake D.
2017-01-01
Food safety is a major concern in the shellfish industry, as severe illness can result from consuming shellfish that have accumulated waterborne pathogens. Shellfish harvesting areas are typically monitored for indicator bacteria such as fecal coliforms that serve as proxies for enteric pathogens although these indicators have shown little relation to some naturally occurring pathogenic bacteria such as Vibrio parahaemolyticus. To examine the dynamics and ecology of pathogenic and non-pathogenic strains of V. parahaemolyticus and address the relevance of indicator bacteria in predicting V. parahaemolyticus concentrations, field surveys and experiments were carried out in western Long Island Sound, NY, USA, a region that has experienced recent outbreaks of shellfish contaminated with V. parahaemolyticus. Pathogenic and non-pathogenic strains were quantified via PCR detection of marker genes and most probable number techniques. Field survey data showed little correspondence between fecal coliforms and V. parahaemolyticus, but significant correlations between V. parahaemolyticus and an alternative indicator, enterococci, and between V. parahaemolyticus and short-term (48 h) rainfall were observed. Experiments demonstrated that enrichment of seawater with phytoplankton-derived dissolved organic matter significantly increased the concentration of total V. parahaemolyticus and the presence pathogenic V. parahaemolyticus, but higher temperatures did not. Collectively, these study results suggest that fecal coliforms may fail to account for the full suite of important shellfish pathogens but that enterococci could provide a potential alternative or supplement to shellfish sanitation monitoring. Given the ability of algal-derived dissolved organic matter to promote the growth of pathogenic V. parahaemolyticus, restricting nutrient inputs into coastal water bodies that promote algal blooms may indirectly decrease the proliferation of V. parahaemolyticus and protect public health. PMID:29020074
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Blaustein, Ryan A; Hill, Robert L; Micallef, Shirley A; Shelton, Daniel R; Pachepsky, Yakov A
2016-01-01
The rainfall-induced release of pathogens and microbial indicators from land-applied manure and their subsequent removal with runoff and infiltration precedes the impairment of surface and groundwater resources. It has been assumed that rainfall intensity and changes in intensity during rainfall do not affect microbial removal when expressed as a function of rainfall depth. The objective of this work was to test this assumption by measuring the removal of Escherichia coli, enterococci, total coliforms, and chloride ion from dairy manure applied in soil boxes containing fescue, under 3, 6, and 9cmh(-1) of rainfall. Runoff and leachate were collected at increasing time intervals during rainfall, and post-rainfall soil samples were taken at 0, 2, 5, and 10cm depths. Three kinetic-based models were fitted to the data on manure-constituent removal with runoff. Rainfall intensity appeared to have positive effects on rainwater partitioning to runoff, and removal with this effluent type occurred in two stages. While rainfall intensity generally did not impact the parameters of runoff-removal models, it had significant, inverse effects on the numbers of bacteria remaining in soil after rainfall. As rainfall intensity and soil profile depth increased, the numbers of indicator bacteria tended to decrease. The cumulative removal of E. coli from manure exceeded that of enterococci, especially in the form of removal with infiltration. This work may be used to improve the parameterization of models for bacteria removal with runoff and to advance estimations of depths of bacteria removal with infiltration, both of which are critical to risk assessment of microbial fate and transport in the environment. Published by Elsevier B.V.
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Quantitative analysis of fecal flora in goat kids with and without floppy kid syndrome.
Bleul, U; Fassbind, N; Ghielmetti, G; Zoller, D; Liesegang, A; Hässig, M; Wittenbrink, M M; Prohaska, S
2013-01-01
Floppy kid syndrome (FKS) affects goat kids in the first month of life and is associated with high morbidity and mortality rates. The condition is characterized by neurological signs that can be ascribed to increased plasma D-lactate concentrations. The source of D-lactate has not been identified conclusively, but D-lactate-producing bacteria in the large intestine are thought to be involved. To determine the number of colony-forming unit (CFUs) of certain groups of bacteria in the feces of kids with and without FKS. Nineteen goat kids with clinical signs of FKS, acidemia (pH ≤ 7.2), and plasma D-lactate concentration >7 mM and 15 healthy goat kids without acidemia (pH >7.2) and D-lactate concentration <1 mM. In this case-control study, the goat kids were examined clinically and blood was collected to measure D-lactate concentration, blood gases, and acid-base parameters. Fecal samples were collected and the total aerobic bacterial count and CFU counts of coliforms, enterococci, staphylococci, streptococci, lactobacilli, and clostridia were determined using the surface plating method. Goat kids with FKS had a mean plasma D-lactate concentration of 10.9 ± 3.7 mM compared with 0.3 ± 0.9 mM in healthy kids, and significantly greater CFU counts for enterococci, streptococci, staphylococci, and lactobacilli than healthy kids. The groups of bacteria present in greater numbers in the feces of goat kids with FKS include several D-lactate-producing species, which makes dysbacteriosis a likely cause of the increased plasma D-lactate concentration in FKS. Copyright © 2013 by the American College of Veterinary Internal Medicine.
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Thickman, Jake D; Gobler, Christopher J
2017-01-01
Food safety is a major concern in the shellfish industry, as severe illness can result from consuming shellfish that have accumulated waterborne pathogens. Shellfish harvesting areas are typically monitored for indicator bacteria such as fecal coliforms that serve as proxies for enteric pathogens although these indicators have shown little relation to some naturally occurring pathogenic bacteria such as Vibrio parahaemolyticus. To examine the dynamics and ecology of pathogenic and non-pathogenic strains of V. parahaemolyticus and address the relevance of indicator bacteria in predicting V. parahaemolyticus concentrations, field surveys and experiments were carried out in western Long Island Sound, NY, USA, a region that has experienced recent outbreaks of shellfish contaminated with V. parahaemolyticus. Pathogenic and non-pathogenic strains were quantified via PCR detection of marker genes and most probable number techniques. Field survey data showed little correspondence between fecal coliforms and V. parahaemolyticus, but significant correlations between V. parahaemolyticus and an alternative indicator, enterococci, and between V. parahaemolyticus and short-term (48 h) rainfall were observed. Experiments demonstrated that enrichment of seawater with phytoplankton-derived dissolved organic matter significantly increased the concentration of total V. parahaemolyticus and the presence pathogenic V. parahaemolyticus, but higher temperatures did not. Collectively, these study results suggest that fecal coliforms may fail to account for the full suite of important shellfish pathogens but that enterococci could provide a potential alternative or supplement to shellfish sanitation monitoring. Given the ability of algal-derived dissolved organic matter to promote the growth of pathogenic V. parahaemolyticus, restricting nutrient inputs into coastal water bodies that promote algal blooms may indirectly decrease the proliferation of V. parahaemolyticus and protect public health.
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NASA Astrophysics Data System (ADS)
Saintil, T.; Radcliffe, D. E.; Rasmussen, T. C.; Kannan, A.
2017-12-01
Fecal coliforms are indicators for disease-causing pathogens. The United States Environmental Protection Agency (US. EPA) recommends the use of E. coli and Enterococci because they are highly correlated with pathogenic organisms in recreational waters. This standard method helps to determine the overall water quality and the potential health risks. Studies have shown that it is difficult to estimate the exact sources of fecal contamination because both human and certain animal species contain E. coli and Enterococci in their waste. Certain strains of E. coli and Enterococci are also able to survive outside of their hosts, which should not be the case for an appropriate fecal indicator. As a result, microbial source tracking (MST) studies use gene specific markers to identify the possible contributors to water pollution whether human or animal. Trail Creek is a second-order stream located in Athens-Clarke County, GA. The 33-km2 watershed is approximately 64% forests, 18% pastures and 16% residential communities. Trail Creek is on the TMDL list and an extended study on the relationships between the different factors causing elevated fecal bacteria is needed. Synoptic sampling events were conducted during baseflow conditions at six locations. Storm sampling events (> 8 mm) were captured using automated samplers at two locations. These samplers were equipped with pressure transducers which record stage at 30-minute intervals. The samples were analyzed for fecal coliform, E. Coli and Enterococci. Water quality parameters including temperature, specific conductance, dissolved oxygen, pH, and turbidity were also recorded. Relationships between the parameters and fecal indicator bacteria show inconsistent patterns and high variability. Using quantitative PCR and MST techniques, the human specific marker (HF183) and ruminant marker (Rum2Bac) were used to identify the fecal sources in both baseflow and storm samples. The presence and abundance of the different markers at each site will be presented. The findings will be useful for adopting best management practices and implementing green infrastructure for the reduction of fecal pollution.
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Lübbert, Christoph; Wendt, Karolin; Feisthammel, Jürgen; Moter, Annette; Lippmann, Norman; Busch, Thilo; Mössner, Joachim; Hoffmeister, Albrecht; Rodloff, Arne C.
2016-01-01
Background Plastic stents used for the treatment of biliary obstruction will become occluded over time due to microbial colonization and formation of biofilms. Treatment of stent-associated cholangitis is often not effective because of inappropriate use of antimicrobial agents or antimicrobial resistance. We aimed to assess the current bacterial and fungal etiology of stent-associated biofilms, with particular emphasis on antimicrobial resistance. Methods Patients with biliary strictures requiring endoscopic stent placement were prospectively enrolled. After the retrieval of stents, biofilms were disrupted by sonication, microorganisms were cultured, and isolates were identified by matrix-associated laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and/or biochemical typing. Finally, minimum inhibitory concentrations (MICs) were determined for various antimicrobial agents. Selected stents were further analyzed by fluorescence in situ hybridization (FISH). Results Among 120 patients (62.5% males, median age 64 years) with biliary strictures (35% malignant, 65% benign), 113 double pigtail polyurethane and 100 straight polyethylene stents were analyzed after a median indwelling time of 63 days (range, 1–1274 days). The stent occlusion rate was 11.5% and 13%, respectively, being associated with a significantly increased risk of cholangitis (38.5% vs. 9.1%, P<0.001). Ninety-five different bacterial and 13 fungal species were detected; polymicrobial colonization predominated (95.8% vs. 4.2%, P<0.001). Enterococci (79.3%), Enterobacteriaceae (73.7%), and Candida spp. (55.9%) were the leading pathogens. Candida species were more frequent in patients previously receiving prolonged antibiotic therapy (63% vs. 46.7%, P = 0.023). Vancomycin-resistant enterococci accounted for 13.7%, extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae with co-resistance to ciprofloxacin accounted for 13.9%, and azole-resistant Candida spp. accounted for 32.9% of the respective isolates. Conclusions Enterococci and Candida species play an important role in the microbial colonization of biliary stents. Therefore, empirical antimicrobial treatment of stent-associated cholangitis should be guided toward enterococci, Enterobacteriaceae, streptococci, anaerobes, and Candida. To determine causative pathogens, an accurate microbiological analysis of the extracted stent(s) may be helpful. PMID:27171497
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Lübbert, Christoph; Wendt, Karolin; Feisthammel, Jürgen; Moter, Annette; Lippmann, Norman; Busch, Thilo; Mössner, Joachim; Hoffmeister, Albrecht; Rodloff, Arne C
2016-01-01
Plastic stents used for the treatment of biliary obstruction will become occluded over time due to microbial colonization and formation of biofilms. Treatment of stent-associated cholangitis is often not effective because of inappropriate use of antimicrobial agents or antimicrobial resistance. We aimed to assess the current bacterial and fungal etiology of stent-associated biofilms, with particular emphasis on antimicrobial resistance. Patients with biliary strictures requiring endoscopic stent placement were prospectively enrolled. After the retrieval of stents, biofilms were disrupted by sonication, microorganisms were cultured, and isolates were identified by matrix-associated laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry and/or biochemical typing. Finally, minimum inhibitory concentrations (MICs) were determined for various antimicrobial agents. Selected stents were further analyzed by fluorescence in situ hybridization (FISH). Among 120 patients (62.5% males, median age 64 years) with biliary strictures (35% malignant, 65% benign), 113 double pigtail polyurethane and 100 straight polyethylene stents were analyzed after a median indwelling time of 63 days (range, 1-1274 days). The stent occlusion rate was 11.5% and 13%, respectively, being associated with a significantly increased risk of cholangitis (38.5% vs. 9.1%, P<0.001). Ninety-five different bacterial and 13 fungal species were detected; polymicrobial colonization predominated (95.8% vs. 4.2%, P<0.001). Enterococci (79.3%), Enterobacteriaceae (73.7%), and Candida spp. (55.9%) were the leading pathogens. Candida species were more frequent in patients previously receiving prolonged antibiotic therapy (63% vs. 46.7%, P = 0.023). Vancomycin-resistant enterococci accounted for 13.7%, extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae with co-resistance to ciprofloxacin accounted for 13.9%, and azole-resistant Candida spp. accounted for 32.9% of the respective isolates. Enterococci and Candida species play an important role in the microbial colonization of biliary stents. Therefore, empirical antimicrobial treatment of stent-associated cholangitis should be guided toward enterococci, Enterobacteriaceae, streptococci, anaerobes, and Candida. To determine causative pathogens, an accurate microbiological analysis of the extracted stent(s) may be helpful.
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Wieland, N; Boss, J; Lettmann, S; Fritz, B; Schwaiger, K; Bauer, J; Hölzel, C S
2017-06-01
The spread of bacteria that are simultaneously resistant to disinfectants and antimicrobials would constitute an unsettling scenario. In order to explore an association between antimicrobial resistance and reduced susceptibility to biocides/microbicides (disinfectants) in agriculture, we investigated Escherichia coli (n = 438) and enterococci (n = 120) isolated from six different flocks of the same poultry farm with known history of antimicrobial treatment. Susceptibility to disinfectants (formic acid and a quaternary ammonium compound (QAC), didecyldimethylammoniumchloride-DDAC) was assessed by macrodilution according to guidelines of the German Veterinary Society. Escherichia coli, Enterococcus faecalis and Enterococcus faecium were screened (i) for reduced biocide susceptibility and (ii) for an association of biocide susceptibility and antimicrobial resistance including the production of extended-spectrum beta-lactamases (ESBL) and the hyperproduction of AmpC-type beta-lactamases. DDAC inhibited ESBL/AmpC(hyper)-producing E. coli (n = 53) from poultry at similar or slightly lower inhibitory concentrations, compared with non-ESBL/AmpC strains (median MIC = 0·36 vs 1·44 mg l -1 ). In contrast, DDAC-MICs were positively correlated with several other antibiotic MICs (e.g. piperacillin and sulphamethoxazole + trimethoprim in E. coli, chloramphenicol in E. faecalis) and increased DDAC-MICs were statistically linked to high-level aminoglycoside resistance in enterococci (streptomycin high level). DDAC-MICs did not correlate with the presence of the integron marker qacEDelta1. This study provides indication that residual disinfectant might be able to select antimicrobial-resistant enterococci, but not ESBL-/AmpC (hyper)producing E. coli from poultry. While ESBL-/AmpC-E. coli were inhibited at disinfectant concentrations comparable to or lower than wildtype values, low concentrations of QACs might be able to select other antimicrobial-resistant E. coli or enterococci-a finding with special significance for the food processing industry, where QACs are regularly used. © 2017 The Society for Applied Microbiology.
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Smith, Cody J.; Olszewski, Adam M.; Mauro, Steven A.
2009-01-01
Shiga toxin (Stx) genes produce proteins that are pathogenic to humans, leading to severe gastrointestinal illness. This work focuses on examining the abundance and distribution of stx genes in relation to common microbial indicators in beach water and streams in the vicinity of Presque Isle State Park in Erie, PA. By use of quantitative PCR, the relative abundance levels of stx DNA in over 700 samples in the sampling area were determined. The results demonstrate that the abundance and distribution of stx genes are variable and do not correlate with the abundance of Escherichia coli bacteria, enterococci, or viral particles. These results suggest that microbial indicators of water quality are not adequate in predicting the occurrence of organisms that harbor stx genes and highlight the need for standardized pathogen-specific detection protocols for waters utilized for recreational swimming. PMID:19011065
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NASA Astrophysics Data System (ADS)
Wildey, R. A.; Ballestero, T. P.; Roseen, R. M.; Houle, J.
2005-05-01
In our efforts to improve the quality of runoff entering our streams and waterways, stormwater management measures (or BMPs) are being implemented at a rapid pace. Usually designed to treat one or more specific types of contamination or loading, these measures may have unintended consequences that are not well understood. One issue that has not been fully explored is the potential effect these systems have on microbial contamination of the treated runoff. This study evaluates 11 types of treatment systems and their impact on E. coli and Enterococci contamination. Recent research has demonstrated that near-shore sediment may act as a continuous source of bacterial loading in the overlying waters, rather than bacterial loading being solely a temporal, storm-driven phenomenon. Similarly, stormwater management measures that utilize a soil media for filtration or incorporate a sediment sump may also provide conditions conducive to the incubation of fecal coliforms that can then be released into the environment during runoff events. Following with EPA regulatory guidelines for receiving waters, E. coli and Enterococci are used as surrogates for the presence of other potential disease-causing pathogens typically associated with mammalian and avian enteric bacteria. The stormwater management measures being investigated include: subsurface infiltration, surface sand filter, standard detention pond, bioretention area, hydrodynamic separation, subsurface gravel wetland, street sweeping, and vegetated swale. An adjacent porous parking area and a standard asphalt lot that drains to a tree filter are similarly monitored. Influent is supplied by runoff generated by a 9-acre commuter parking lot at the University of New Hampshire in Durham, NH. This influent is distributed equally to the different treatment devices that operate in parallel. Water quality parameters (DO, pH, specific conductivity, temperature) and flow are continuously monitored upstream from the distribution chamber (influent) and downstream from each device (effluent). Automated samplers are used to collect samples during storm events and grab samples are taken between storm events to evaluate the effect of each device or BMP on bacterial populations. Initial data indicate that influent concentrations of fecal coliforms for this parking area often exceed EPA limits for Class A waterbodies. Several of the treatment units appear to substantially reduce (>90% reduction) bacterial loading, while others appear to increase loading during some storm events (>500% increase). This study is on-going and additional sample events from the Spring of 2005 will also be presented.
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Heaney, Christopher D.; Wing, Steve; Wilson, Sacoby M.; Campbell, Robert L.; Caldwell, David; Hopkins, Barbara; O’Shea, Shannon; Yeatts, Karin
2015-01-01
The historically African-American Rogers-Eubanks community straddles unincorporated boundaries of two municipalities in Orange County, North Carolina, and predates a regional landfill sited along its border in 1972. Community members from the Rogers-Eubanks Neighborhood Association (RENA), concerned about deterioration of private wells and septic systems and a lack of public drinking water and sewer services, implemented a community-driven research partnership with university scientists and community-based organizations to investigate water and sewer infrastructure disparities and the safety of drinking and surface water supplies. RENA drafted memoranda of agreement with partners and trained community monitors to collect data (inventory households, map water and sewer infrastructure, administer household water and sewer infrastructure surveys, and collect drinking and surface water samples). Respondents to the surveys reported pervasive signs of well vulnerability (100%) and septic system failure (68%). Each 100-m increase in distance from the landfill was associated with a 600 most probable number/100 mL decrease in enterococci concentrations in surface water (95% confidence interval = −1106, −93). Pervasive private household water and sewer infrastructure failures and poor water quality were identified in this community bordering a regional landfill, providing evidence of a need for improved water and sanitation services. PMID:23858663
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Identification and management of microbial contaminations in a surface drinking water source.
Aström, J; Pettersson, T J R; Stenström, T A
2007-01-01
Microbial contamination of surface waters constitutes a health risk for drinking water consumers which may be lowered by closing the raw water intake. We have evaluated microbial discharge events reported in the river Göta älv, which is used for raw water supply to the city of Göteborg. Elevated levels of faecal indicator bacteria were observed during periods of closed raw water intake. High bacteria levels were, however, also occasionally detected during periods of open intake, probably as a result of microbial discharge far upstream in the river which may be difficult to predict and manage by closing the intake. Accumulated upstream precipitations, resulting in surface runoff and wastewater contaminations in the catchment, correlated positively with the levels of total coliforms, E. coli, intestinal enterococci and sulfite-reducing clostridia. Levels of faecal indicator organisms were negatively correlated to the water temperature due to enhanced survival at lower temperatures. Wastewater discharges from a municipality located just upstream of the water intake resulted in elevated E. coli concentrations downstream at the raw water intake for Göteborg. To improve the prediction of microbial contaminations within the river Göta älv, monitoring data on turbidity and upstream precipitation are of particular importance.
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NASA Astrophysics Data System (ADS)
Masciopinto, Costantino; Visino, Fabrizio; Luprano, Maria Laura; Levantesi, Caterina; Tandoi, Valter
2015-04-01
The spreading of microbial contamination into the environment, represents a very relevant problem, which leads to an increasing health concern. For this reason, it is important to identify and characterize the extent of natural depuration in water environmental particularly for reducing the presence of faecal contamination indicator bacteria, pathogens and antibiotic resistance genes (ARG). In this study, the presence of the above reported microbial parameters was analyzed in a surface water channel and in a coastal aquifer in southern Italy (Ostuni) southern Italy, both affected by Ostuni municipal treatment plant effluents and by local run-off. Several samples were collected from surface water, flowing in channels, and from wells in our study area. In particular, the water samples were analyzed to detect 7 fecal contamination indicators (E. coli, total coliforms, Clostridium p. spores, somatic coliphages, Enterococci and heterotrophic bacteria), Salmonella spp and the presence of ARGs. The water samples were also tested for chemical constituents. Finally a mathematical model has been developed in order to simulate pathogen migration pathways in the fractured groundwater and corresponding possible mitigation of pathogens in pumping wells.
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[Current resistence situation in a surgical and urological department].
Wacha, H; Stix, H
1976-04-15
Spectrum and sensitivity of bacteria were studied at the Surgical (534 positive wound smears) and the Urological Clinics (7879 urine specimens). Krankenhaus Nordwest, Frankfurt/M., during the period of 1969-1971 and in 1973. The most common organisms identified in wound smears were E. coli, followed by Staph. areus, Aerobacter and Proteus species. E. coli were also predominant in urine, but followed by Enterococci, Proteus and Pseudomonas. E. coli, Proteus species and especially Pseudomonas increased in number whereas Enterococci decreased. There was no pronounced increase in resistance to 9 current antibiotics as well as to chemotherapeutics during the observation period which was particularly striking in the case of Ampicillin used on a large scale. The results of our study support the presently employed therapeutic method using bactericidal antibiotics of the penicillin group in strict indications.
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Application of a Human Fecal Marker Assay to Diverse Coastal Environments in California and Hawaii
NASA Astrophysics Data System (ADS)
Layton, B.; Boehm, A.
2007-05-01
Bacterial pollution at beaches is a growing problem of increasing national concern. Currently, the EPA uses Enterococcus as one measure of water quality for recreational contact. Recent work has suggested that rather than indicating anthropogenic pollution, enterococci may be indigenous to the environment. A human-specific gene marker for Enterococcus faecium (known as esp) was recently proposed as a molecular test for bacterial contamination of human origin. The present study applied the esp gene assay to a variety of coastal environments in California and Hawaii, including groundwater, sand, freshwater creeks, estuaries, and the surf zone. Results indicate that enterococci of human origin are present in many of these environments, suggesting that at least a portion of the bacterial pollution at these sites is a result of anthropogenic inputs rather than autochthonous microbial populations.
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Gilhuley, Kathleen; Cianciminio-Bordelon, Diane; Tang, Yi-Wei
2012-01-01
We compared the performance characteristics of culture and the Cepheid Xpert vanA assay for routine surveillance of vancomycin-resistant enterococci (VRE) from rectal swabs in patients at high risk for VRE carriage. The Cepheid Xpert vanA assay had a limit of detection of 100 CFU/ml and correctly detected 101 well-characterized clinical VRE isolates with no cross-reactivity in 27 non-VRE and related culture isolates. The clinical sensitivity, specificity, positive predictive value, and negative predictive value of the Xpert vanA PCR assay were 100%, 96.9%, 91.3%, and 100%, respectively, when tested on 300 consecutively collected rectal swabs. This assay provides excellent predictive values for prompt identification of VRE-colonized patients in hospitals with relatively high rates of VRE carriage. PMID:22972822
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Nateghian, A; Robinson, J L; Arjmandi, K; Vosough, P; Karimi, A; Behzad, A; Navidnia, M
2011-05-01
Risk factors for colonization with vancomycin-resistant enterococci (VRE) vary by population and locale. The objective of this study was to determine the prevalence of and risk factors for VRE colonization in children with acute lymphoblastic leukemia (ALL) in Tehran. Stools were collected from children with ALL at the Ali Asghar Children's Hospital and the Mahak Pediatric Oncology Center between March 2007 and October 2008. Demographic features and potential risk factors for VRE colonization, including duration of ALL, presence of severe neutropenia in the preceding month, receipt of antibiotics in the preceding 3 months, concurrent medical problems, days of hospitalization, and the need for intensive care since the time of diagnosis of ALL, were recorded. VRE was identified from stools in 33 of 130 children with ALL (25%). No clear risk factors were identified for VRE colonization in the current study, but there was a trend towards an increased prevalence in children admitted to the intensive care unit since their ALL diagnosis (p=0.07). The VanA genotype was found in 28 of the 33 stools (85%), with all other enterococci being VanB. The prevalence of VRE colonization in children with ALL in Tehran is high. Modifiable risk factors have not been identified. The implementation of routine surveillance for colonization and an increased emphasis on adherence to standard infection control precautions may prevent spread. Copyright © 2011 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
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Larsson, Marie C; Karlsson, Ewa; Woksepp, Hanna; Frölander, Kerstin; Mårtensson, Agneta; Rashed, Foad; Annika, Wistedt; Schön, Thomas; Serrander, Lena
2014-03-19
The aim of this study was to evaluate diagnostic tests in order to introduce a diagnostic strategy to identify the most common gram-positive bacteria (pneumococci, enterococci, β-haemolytic streptococci and S. aureus) found in blood cultures within 6 hours after signalling growth. The tube coagulase test was optimized and several latex agglutination tests were compared and evaluated before a validation period of 11 months was performed on consecutive positive blood culture patient samples from Kalmar County Hospital, Sweden. During the validation period 150 (91%) of a total of 166 gram-positive cocci (119 in clusters, 45 in chains or pairs and 2 undefined morphology) were correctly identified as S. aureus, CoNS, Pneumococci, Enterococci or group A streptococci (GAS), group B streptococci (GBS), group G streptococci (GGS) within 6 hours with a minimal increase in work-load and costs. The remaining samples (9%) were correctly identified during the next day. No samples were incorrectly grouped with this diagnostic strategy and no patient came to risk by early reporting. A simple strategy gives reliable and cost-effective reporting of >90% of the most common gram-positive cocci within 6 hours after a blood cultures become positive. The high specificity of the tests used makes preliminary reports reliable. The reports can be used to indicate the focus of infection and not the least, support faster administration of proper antimicrobial treatment for patients with serious bacterial infections.
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Molina-Navarro, E; Martínez-Pérez, S; Sastre-Merlín, A; Soliveri, J; Fernández-Monistrol, I; Copa-Patiño, J L
2011-03-01
Bordering on the edge of the Entrepeñas reservoir (Guadalajara, Spain), next to the village of Pareja, a small dam that allows a body of water to develop with a constant level has been built. Initiatives like this (which we have termed "limno-reservoirs") are innovative in Spain and around the world. Earlier reservoirs such as this one were constructed to create a habitat for birds, but the Pareja limno-reservoir is the first to promote socio-economic development. In order to study this limno-reservoir, this research group set up an environmental observatory, analyzing, among other variables, microbiological water quality and nutrient content. After a year and a half of research, it was observed that the concentration of microorganisms is lower in the limno-reservoir than in the river that feeds it, possibly due to the nutrient depletion in the lentic ecosystem. In the limno-reservoir, the total coliforms and enterococci concentrations fall within the European Bathing Water Directive limits, but in the river these concentrations are sometimes higher. The nutrient load in the limno-reservoir is low, with nutrient variations influencing native microorganisms, but not for total coliforms and enterococci. However, the development of special conditions in the bottom has been observed in winter, facilitating coliforms and enterococci survival. This research is very interesting since the creation of limno-reservoirs is rising in Spain and no research is being done on their behaviour. Copyright © 2010 Elsevier Ltd. All rights reserved.
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Antimicrobial copper alloys decreased bacteria on stethoscope surfaces.
Schmidt, Michael G; Tuuri, Rachel E; Dharsee, Arif; Attaway, Hubert H; Fairey, Sarah E; Borg, Keith T; Salgado, Cassandra D; Hirsch, Bruce E
2017-06-01
Stethoscopes may serve as vehicles for transmission of bacteria among patients. The aim of this study was to assess the efficacy of antimicrobial copper surfaces to reduce the bacterial concentration associated with stethoscope surfaces. A structured prospective trial involving 21 health care providers was conducted at a pediatric emergency division (ED) (n = 14) and an adult medical intensive care unit located in tertiary care facilities (n = 7). Four surfaces common to a stethoscope and a facsimile instrument fabricated from U.S. Environmental Protection Agency-registered antimicrobial copper alloys (AMCus) were assessed for total aerobic colony counts (ACCs), methicillin-resistant Staphylococcus aureus, gram-negative bacteria, and vancomycin-resistant enterococci for 90 days. The mean ACCs collectively recovered from all stethoscope surfaces fabricated from the AMCus were found to carry significantly lower concentrations of bacteria (pediatric ED, 11.7 vs 127.1 colony forming units [CFU]/cm 2 , P < .00001) than their control equivalents. This observation was independent of health care provider or infection control practices. Absence of recovery of bacteria from the AMCu surfaces (66.3%) was significantly higher (P < .00001) than the control surfaces (22.4%). The urethane rim common to the stethoscopes was the most heavily burdened surface; mean concentrations exceeded the health care-associated infection acquisition concentration (5 CFU/cm 2 ) by at least 25×, supporting that the stethoscope warrants consideration in plans mitigating microbial cross-transmission during patient care. Stethoscope surfaces fabricated with AMCus were consistently found to harbor fewer bacteria. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
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Francy, Donna S.; Bushon, Rebecca N.; Stopar, Julie; Luzano, Emma J.; Fout, G. Shay
2004-01-01
A study of small public ground-water-supply wells that produce water from discontinuous sand and gravel aquifers was done from July 1999 through July 2001 in southeastern Michigan. Samples were collected to determine the occurrence of viral pathogens and microbiological indicators of fecal contamination (indicators), determine whether indicators are adequate predictors of the presence of enteric viruses, and determine the factors that affect the presence of enteric viruses. Small systems are those that serve less than 3,300 people. Samples were analyzed for specific enteric viruses by reverse transcriptase-polymerase chain reaction (RT-PCR), for culturable viruses by cell culture, and for the indicators total coliforms, Escherichia coli (E. coli), enterococci, and F-specific and somatic coliphage. Ancillary environmental and water-quality data were collected or compiled. A total of 169 regular samples and 32 replicate pairs were collected from 38 wells. Replicate pairs were samples collected at the same well on the same date. One well was sampled 6 times, 30 wells were sampled five times, 6 wells were sampled twice, and 1 well was sampled once. By use of RT-PCR, enterovirus was found in four wells (10.5 percent) and hepatitis A virus (HAV) in five wells (13.2 percent). In two of these wells, investigators found both enterovirus and HAV, but on different sampling dates. Culturable viruses were found one time in two wells (5.9 percent), and neither of these wells was positive for viruses by use of RT-PCR on any sampling date. If results for all viruses are combined, 9 of the 38 small public-supply wells were positive for enteric viruses (23.7 percent) by either cell culture or RT-PCR. One or more indicators were found in 18 of 38 wells. Total coliforms, E. coli, enterococci, and F-specific and somatic coliphage were found in 34.2, 10.5, 15.8, 5.9, and 5.9 percent, respectively, of the wells tested. In only 3 out of 18 wells were samples positive for an indicator on more than one date at the same well. The co-occurrence of enteric viruses and any indicator was 55.6 percent; five out of the nine virus-positive wells were also found to be positive for an indicator. Two wells with detections of viruses had a detection of total coliforms, one well had a detection of E. coli, one of enterococci, and one of F-specific coliphage. On a per sample basis, of 11 samples that were positive for enteric viruses, indicator bacteria co-occurred in only 2 samples, and coliphage were not present in any. More virus-positive samples were found at sites served by septic systems than those served by sewerlines. Sampling condition (ground water or a mixture of tank and ground water), distance to septic system, type of and distance to nearest surface-water body, well characteristics, or land use were not related to the presence of viruses or indicators. Among continuous water-quality variables, statistically significant relations were found between total coliforms and dissolved organic carbon and between total coliforms and iron. There was a statistically significant relation between chloride concentrations >20 mg/L and detections of total coliforms. Presence of nitrate and nitrite was related to the presence of other indicators (E. coli, enterococci, and F-specific and somatic coliphage) or enteric viruses, but not to total coliforms. The data indicated that chloride-to-bromide (C1:Br) ratios may be useful as a screening tool for total coliforms and enteric viruses but not for E. coli, enterococci, and F-specific and somatic coliphage. This study provides evidence for fecal contamination of ground water from small public-supply wells, at least on an intermittent basis. Collecting data on multiple lines of evidence would be needed to reliably predict the presence of enteric viruses and protect public health. Future data collection toward this end could include repeat sampling several times a year for different indicators, measuring dissolv
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Krupkin, Miri; Wekselman, Itai; Matzov, Donna; Eyal, Zohar; Diskin Posner, Yael; Rozenberg, Haim; Zimmerman, Ella; Bashan, Anat; Yonath, Ada
2016-01-01
Two structurally unique ribosomal antibiotics belonging to the orthosomycin family, avilamycin and evernimicin, possess activity against Enterococci, Staphylococci, and Streptococci, and other Gram-positive bacteria. Here, we describe the high-resolution crystal structures of the eubacterial large ribosomal subunit in complex with them. Their extended binding sites span the A-tRNA entrance corridor, thus inhibiting protein biosynthesis by blocking the binding site of the A-tRNA elbow, a mechanism not shared with other known antibiotics. Along with using the ribosomal components that bind and discriminate the A-tRNA—namely, ribosomal RNA (rRNA) helices H89, H91, and ribosomal proteins (rProtein) uL16—these structures revealed novel interactions with domain 2 of the CTC protein, a feature typical to various Gram-positive bacteria. Furthermore, analysis of these structures explained how single nucleotide mutations and methylations in helices H89 and H91 confer resistance to orthosomycins and revealed the sequence variations in 23S rRNA nucleotides alongside the difference in the lengths of the eukaryotic and prokaryotic α1 helix of protein uL16 that play a key role in the selectivity of those drugs. The accurate interpretation of the crystal structures that could be performed beyond that recently reported in cryo-EM models provide structural insights that may be useful for the design of novel pathogen-specific antibiotics, and for improving the potency of orthosomycins. Because both drugs are extensively metabolized in vivo, their environmental toxicity is very low, thus placing them at the frontline of drugs with reduced ecological hazards. PMID:27791159
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LocZ Is a New Cell Division Protein Involved in Proper Septum Placement in Streptococcus pneumoniae
Holečková, Nela; Molle, Virginie; Buriánková, Karolína; Benada, Oldřich; Kofroňová, Olga; Ulrych, Aleš; Branny, Pavel
2014-01-01
ABSTRACT How bacteria control proper septum placement at midcell, to guarantee the generation of identical daughter cells, is still largely unknown. Although different systems involved in the selection of the division site have been described in selected species, these do not appear to be widely conserved. Here, we report that LocZ (Spr0334), a newly identified cell division protein, is involved in proper septum placement in Streptococcus pneumoniae. We show that locZ is not essential but that its deletion results in cell division defects and shape deformation, causing cells to divide asymmetrically and generate unequally sized, occasionally anucleated, daughter cells. LocZ has a unique localization profile. It arrives early at midcell, before FtsZ and FtsA, and leaves the septum early, apparently moving along with the equatorial rings that mark the future division sites. Consistently, cells lacking LocZ also show misplacement of the Z-ring, suggesting that it could act as a positive regulator to determine septum placement. LocZ was identified as a substrate of the Ser/Thr protein kinase StkP, which regulates cell division in S. pneumoniae. Interestingly, homologues of LocZ are found only in streptococci, lactococci, and enterococci, indicating that this close phylogenetically related group of bacteria evolved a specific solution to spatially regulate cell division. PMID:25550321
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A Predictive Model for Microbial Counts on Beaches where Intertidal Sand is the Primary Source
Feng, Zhixuan; Reniers, Ad; Haus, Brian K.; Solo-Gabriele, Helena M.; Wang, John D.; Fleming, Lora E.
2015-01-01
Human health protection at recreational beaches requires accurate and timely information on microbiological conditions to issue advisories. The objective of this study was to develop a new numerical mass balance model for enterococci levels on nonpoint source beaches. The significant advantage of this model is its easy implementation, and it provides a detailed description of the cross-shore distribution of enterococci that is useful for beach management purposes. The performance of the balance model was evaluated by comparing predicted exceedances of a beach advisory threshold value to field data, and to a traditional regression model. Both the balance model and regression equation predicted approximately 70% the advisories correctly at the knee depth and over 90% at the waist depth. The balance model has the advantage over the regression equation in its ability to simulate spatiotemporal variations of microbial levels, and it is recommended for making more informed management decisions. PMID:25840869
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Lü, Yuhong; Shao, Meiyun; Wang, Yinyin; Qian, Shengyan; Wang, Miao; Wang, Yingquan; Li, Xiaoqian; Bao, Yuxin; Deng, Chengmin; Yue, Changwu; Liu, Daishun; Liu, Ning; Liu, Minghao; Huang, Ying; Chen, Zehui; Hu, Yonglin
2017-02-08
This study performed an optimization of the fermentation conditions to activate the expression of the zunyimycin family biosynthesis genes of the zunyimycin-producing streptomycetes strain Streptomyces sp. FJS31-2. Bioassay-guided isolation and purification by varied chromatographic methods yielded two new compounds of the zunyimycin derivatives, namely, 31-2-7 and 31-2-8, accompanied with three known anthrabenzoxocinones family members of zunyimycin A, BE24566B, and chloroanthrabenzoxocinone. Their structures were elucidated by NMR, HRESIMS, IR, UV, and CD. Results showed that these two compounds were structurally similar to the previously reported compound zunyimycin A but differed in positions and number of chlorine atom substitution. The two novel compounds were called zunyimycins B and C. Antibacterial activity assay indicated that zunyimycin C showed a good inhibitory effect on the methicillin-resistant Staphylococcus aureus and Enterococci .
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Nurses' experience with vancomycin-resistant enterococci (VRE).
Mitchell, Ann; Cummins, Teresa; Spearing, Natalie; Adams, June; Gilroy, Lisa
2002-01-01
The emergence and spread of resistant organisms, in particular vancomycin-resistant enterococci (VRE), is an issue facing all staff in acute hospitals. This study explored how nurses coped with the responsibility of halting further spread of this organism during an outbreak. VRE-positive patients were cohorted with nurses who cared for them in an endeavour to contain the spread of VRE. The majority of nurses found the situation extremely stressful because of the need to act as 'gatekeepers' responsible for educating and monitoring the practices of staff and visitors. The nurses reported that they felt they were inadequately supported, were blamed for the outbreak, and that they had an increased workload as they took on duties of other staff. The results reinforce the need for a multidisciplinary team approach to education and control of VRE, more support for nursing staff cohorted with VRE-positive patients, and stringent adherence to infection control measures by all hospital staff.
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A 1.5 hour procedure for identification of Enterococcus Species directly from blood cultures.
Morgan, Margie A; Marlowe, Elizabeth; Novak-Weekly, Susan; Miller, J M; Painter, T M; Salimnia, Hossein; Crystal, Benjamin
2011-02-10
Enterococci are a common cause of bacteremia with E. faecalis being the predominant species followed by E. faecium. Because resistance to ampicillin and vancomycin in E. faecalis is still uncommon compared to resistance in E. faecium, the development of rapid tests allowing differentiation between enterococcal species is important for appropriate therapy and resistance surveillance. The E. faecalis OE PNA FISH assay (AdvanDx, Woburn, MA) uses species-specific peptide nucleic acid (PNA) probes in a fluorescence in situ hybridization format and offers a time to results of 1.5 hours and the potential of providing important information for species-specific treatment. Multicenter studies were performed to assess the performance of the 1.5 hour E. faecalis/OE PNA FISH procedure compared to the original 2.5 hour assay procedure and to standard bacteriology methods for the identification of enterococci directly from a positive blood culture bottle.
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A 1.5 Hour Procedure for Identification of Enterococcus Species Directly from Blood Cultures
Morgan, Margie A.; Marlowe, Elizabeth; Novak-Weekly, Susan; Miller, J.M.; Painter, T.M.; Salimnia, Hossein; Crystal, Benjamin
2011-01-01
Enterococci are a common cause of bacteremia with E. faecalis being the predominant species followed by E. faecium. Because resistance to ampicillin and vancomycin in E. faecalis is still uncommon compared to resistance in E. faecium, the development of rapid tests allowing differentiation between enterococcal species is important for appropriate therapy and resistance surveillance. The E. faecalis OE PNA FISH assay (AdvanDx, Woburn, MA) uses species-specific peptide nucleic acid (PNA) probes in a fluorescence in situ hybridization format and offers a time to results of 1.5 hours and the potential of providing important information for species-specific treatment. Multicenter studies were performed to assess the performance of the 1.5 hour E. faecalis/OE PNA FISH procedure compared to the original 2.5 hour assay procedure and to standard bacteriology methods for the identification of enterococci directly from a positive blood culture bottle. PMID:21339730
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Kenters, Nikki; Huijskens, Elisabeth G W; de Wit, Sophie C J; van Rosmalen, Joost; Voss, Andreas
2017-08-01
Hospital rooms play an important role in the transmission of several health care-associated pathogens. During the last few years, a number of innovative cleaning-disinfecting products have been brought to market. In this study, commercially available products combining cleaning and disinfection were compared, using 2 different application methods. The aim was to determine which product was most effective in simultaneous cleaning and disinfection of surfaces. Seven cleaning-disinfecting wipes and sprays based on different active ingredients were tested for their efficacy in removal of microbial burden and proteins. Efficacy was tested with known Dutch outbreak strains: vancomycin-resistant enterococci (VRE), Klebsiella pneumoniae OXA-48, or Acinetobacter baumannii. For all bacteria, ready-to-use cleaning-disinfecting products reduced the microbial count with a log 10 reduction >5 with a 5-minute exposure time, with the exception of a spray based on hydrogen peroxide. Omitting the aforementioned hydrogen peroxide spray, there were no significant differences between use of a wipe or spray in bacterial load reduction. Using adenosine triphosphate (ATP) measurements, a significant difference in log 10 relative light units (RLU) reduction between various bacteria (P ≤ .001) was observed. In general, a >5 log 10 reduction of colony forming units (CFU) for tested wipes and sprays was obtained for all tested bacteria strains, with exception of hydrogen peroxide spray and VRE. Although ATP may show a difference between pre- and postcleaning, RLU reduction does not correlate with actual CFU reductions. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
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Occurrence of the structural enterocin A, P, B, L50B genes in enterococci of different origin.
Strompfová, Viola; Lauková, Andrea; Simonová, Monika; Marcináková, Miroslava
2008-12-10
Enterococci are well-known producers of antimicrobial peptides--bacteriocins (enterocins) and the number of characterized enterocins has been significantly increased. Recently, enterocins are of great interest for their potential as biopreservatives in food or feed while research on enterocins as alternative antimicrobials in humans and animals is only at the beginning. The present study provides a survey about the occurrence of enterocin structural genes A, P, B, L50B in a target of 427 strains of Enterococcus faecium (368) and Enterococcus faecalis (59) species from different sources (animal isolates, food and feed) performed by PCR method. Based on our results, 234 strains possessed one or more enterocin structural gene(s). The genes of enterocin P and enterocin A were the most frequently detected structural genes among the PCR positive strains (170 and 155 strains, respectively). Different frequency of the enterocin genes occurrence was detected in strains according to their origin; the strains from horses and silage showed the highest frequency of enterocin genes presence. All possible combinations of the tested genes occurred at least twice except the combination of the gene of enterocin B and L50B which possessed neither strain. The gene of enterocin A was exclusively detected among E. faecium strains, while the gene of enterocin P, B, L50B were detected in strains of both species E. faecium and E. faecalis. In conclusion, a high-frequency and variability of enterocin structural genes exists among enterococci of different origin what offers a big possibility to find effective bacteriocin-producing strains for their application in veterinary medicine.
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Polymicrobial Infective Endocarditis: Clinical Features and Prognosis
García-Granja, Pablo Elpidio; López, Javier; Vilacosta, Isidre; Ortiz-Bautista, Carlos; Sevilla, Teresa; Olmos, Carmen; Sarriá, Cristina; Ferrera, Carlos; Gómez, Itziar; Román, José Alberto San
2015-01-01
Abstract To describe the profile of left-sided polymicrobial endocarditis (PE) and to compare it with monomicrobial endocarditis (ME). Among 1011 episodes of left-sided endocarditis consecutively diagnosed in 3 tertiary centers, between January 1, 1996 and December 31, 2014, 60 were polymicrobial (5.9%), 821 monomicrobial (81.7%), and in 123 no microorganism was detected (12.2%). Seven patients (0.7%) were excluded from the analysis because contamination of biologic tissue could not be discarded. The authors described the clinical, microbiologic, echocardiographic, and outcome of patients with PE and compared it with ME. Mean age was 64 years SD 16 years, 67% were men and 30% nosocomial. Diabetes mellitus (35%) were the most frequent comorbidities, fever (67%) and heart failure (43%) the most common symptoms at admission. Prosthetic valves (50%) were the most frequent infection location and coagulase-negative Staphylococci (48%) and enterococci (37%) the leading etiologies. The most repeated combination was coagulase-negative Staphylococci with enterococci (n = 9). Polymicrobial endocarditis appeared more frequently in patients with underlying disease (70% versus 56%, P = 0.036), mostly diabetics (35% versus 24%, P = 0.044) with previous cardiac surgery (15% versus 8% P = 0.049) and prosthetic valves (50% versus 37%, P = 0.038). Coagulase-negative Staphylococci, enterococci, Gram-negative bacilli, anaerobes, and fungi were more frequent in PE. No differences on age, sex, symptoms, need of surgery, and in-hospital mortality were detected. Polymicrobial endocarditis represents 5.9% of episodes of left-sided endocarditis in our series. Despite relevant demographic and microbiologic differences between PE and ME, short-term outcome is similar. PMID:26656328
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Glycopeptide Resistance vanA Operons in Paenibacillus Strains Isolated from Soil
Guardabassi, Luca; Perichon, Bruno; van Heijenoort, Jean; Blanot, Didier; Courvalin, Patrice
2005-01-01
The sequence and gene organization of the van operons in vancomycin (MIC of >256 μg/ml)- and teicoplanin (MIC of ≥32 μg/ml)-resistant Paenibacillus thiaminolyticus PT-2B1 and Paenibacillus apiarius PA-B2B isolated from soil were determined. Both operons had regulatory (vanR and vanS), resistance (vanH, vanA, and vanX), and accessory (vanY, vanZ, and vanW) genes homologous to the corresponding genes in enterococcal vanA and vanB operons. The vanAPT operon in P. thiaminolyticus PT-2B1 had the same gene organization as that of vanA operons whereas vanAPA in P. apiarius PA-B2B resembled vanB operons due to the presence of vanW upstream from the vanHAX cluster but was closer to vanA operons in sequence. Reference P. apiarius strains NRRL B-4299 and NRRL B-4188 were found to harbor operons indistinguishable from vanAPA by PCR mapping, restriction fragment length polymorphism, and partial sequencing, suggesting that this operon was species specific. As in enterococci, resistance was inducible by glycopeptides and associated with the synthesis of pentadepsipeptide peptidoglycan precursors ending in d-Ala-d-Lac, as demonstrated by d,d-dipeptidase activities, high-pressure liquid chromatography, and mass spectrometry. The precursors differed from those in enterococci by the presence of diaminopimelic acid instead of lysine in the peptide chain. Altogether, the results are compatible with the notion that van operons in soil Paenibacillus strains and in enterococci have evolved from a common ancestor. PMID:16189102
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Glycopeptide resistance vanA operons in Paenibacillus strains isolated from soil.
Guardabassi, Luca; Perichon, Bruno; van Heijenoort, Jean; Blanot, Didier; Courvalin, Patrice
2005-10-01
The sequence and gene organization of the van operons in vancomycin (MIC of >256 microg/ml)- and teicoplanin (MIC of > or =32 microg/ml)-resistant Paenibacillus thiaminolyticus PT-2B1 and Paenibacillus apiarius PA-B2B isolated from soil were determined. Both operons had regulatory (vanR and vanS), resistance (vanH, vanA, and vanX), and accessory (vanY, vanZ, and vanW) genes homologous to the corresponding genes in enterococcal vanA and vanB operons. The vanA(PT) operon in P. thiaminolyticus PT-2B1 had the same gene organization as that of vanA operons whereas vanA(PA) in P. apiarius PA-B2B resembled vanB operons due to the presence of vanW upstream from the vanHAX cluster but was closer to vanA operons in sequence. Reference P. apiarius strains NRRL B-4299 and NRRL B-4188 were found to harbor operons indistinguishable from vanA(PA) by PCR mapping, restriction fragment length polymorphism, and partial sequencing, suggesting that this operon was species specific. As in enterococci, resistance was inducible by glycopeptides and associated with the synthesis of pentadepsipeptide peptidoglycan precursors ending in D-Ala-D-Lac, as demonstrated by D,D-dipeptidase activities, high-pressure liquid chromatography, and mass spectrometry. The precursors differed from those in enterococci by the presence of diaminopimelic acid instead of lysine in the peptide chain. Altogether, the results are compatible with the notion that van operons in soil Paenibacillus strains and in enterococci have evolved from a common ancestor.
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Vignaroli, Carla; Zandri, Giada; Aquilanti, Lucia; Pasquaroli, Sonia; Biavasco, Francesca
2011-05-01
Forty-eight isolates resistant to at least two antibiotics were selected from 53 antibiotic-resistant enterococci from chicken and pig meat and faeces and analysed for specific resistance determinants. Of the 48 multidrug-resistant (MDR) strains, 31 were resistant to two antibiotics (29 to erythromycin and tetracycline, 1 to erythromycin and vancomycin, 1 to vancomycin and tetracycline), 14 to three (erythromycin, tetracycline and vancomycin or ampicillin) and 3 to four (erythromycin, vancomycin, ampicillin and gentamicin). erm(B), tet(M), vanA and aac (6')-Ie aph (2'')-Ia were the antibiotic resistance genes most frequently detected. All 48 MDR enterococci were susceptible to linezolid and daptomycin. Enterococcus faecalis (16), Enterococcus faecium (8), Enterococcus mundtii (2) and Enterococcus gallinarum (1) were identified in meat, and E. faecium (13) and Enterococcus durans (13) in faeces. Clonal spread was not detected, suggesting a large role of gene transfer in the dissemination of antibiotic resistance. Conjugative transfer of resistance genes was more successful when donors were enterococcal strains isolated from faeces; co-transfer of vanA and erm(B) to a human E. faecium occurred from both E. faecium and E. durans pig faecal strains. These data show that multidrug resistance can be found in food and animal species other than E. faecium and E. faecalis, and that these species can efficiently transfer antibiotic resistance to human strains in inter-specific matings. In particular, the occurrence of MDR E. durans in the animal reservoir could have a role in the emergence of human enterococcal infections difficult to eradicate with antibiotics.
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Banerjee, Tuhina; Anupurba, Shampa
2016-10-01
Fluoroquinolone resistance in both Gram-positive and Gram-negative bacteria has increased with the widespread use of fluoroquinolones. Fluoroquinolone resistance in Gram-negative bacilli has been widely studied, though staphylococci and enterococci are also notably resistant. Enterococci being the second most common cause of healthcare-associated urinary tract infections (UTIs) fluoroquinolones are often the drug of choice. This study was undertaken to assess the risk factors associated with fluoroquinolone-resistant enterococcal UTI in a tertiary level health facility in north India. A total of 365 patients with UTI caused by enterococci were studied over a period of two years. Patients with ciprofloxacin-resistant and susceptible UTI were considered as cases and controls, respectively. Resistance profile of the isolates against common antibiotics was studied by minimum inhibitory concentration (MIC) determination. Mechanisms for fluoroquinolone resistance was studied by efflux pump inhibitor activity and multiplex PCR targeting the qnr genes. A total of 204 (55.89%) cases and 161 (44.1%) controls were identified. The fluoroquinolone-resistant isolates were significantly resistant to ampicillin, high strength aminoglycosides and vancomycin. The majority (78%) of the resistant isolates showed efflux pump activity. Treatment in indoor locations, presence of urinary catheters and pregnancy along with recent exposure to antibiotics especially fluoroquinolones, third generation cephalosporins and piperacillin-tazobactam were identified as independent risk factors. Our results showed that fluoroquinolone resistance in enterococcal UTI was largely associated with indoor usage of antibiotics and use of indwelling devices. Knowledge of risk factors is important to curb this emergence of resistance.
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Turnbull, L.; Brosnikoff, C.; Cloke, J.
2012-01-01
The M.I.C. Evaluator strip (Thermo Fisher Scientific, Basingstoke, United Kingdom) uses a methodology similar to that of Etest. In this first assessment of the M.I.C. Evaluator device, 409 strains of aerobic Gram-positive bacteria (staphylococci, streptococci, and enterococci) and 325 strains of Enterobacteriaceae, Pseudomonas species, and Acinetobacter species were tested by M.I.C. Evaluator strip, Etest, and broth microdilution as a reference standard. The Gram-positive bacteria included staphylococci (methicillin-resistant Staphylococcus aureus, methicillin-susceptible S. aureus, and coagulase-negative staphylococci), Streptococcus pneumoniae, beta-hemolytic streptococci and viridians group strains, vancomycin-resistant enterococci, and other enterococci. The Gram-negative bacteria included 250 strains of 60 Enterobacteriaceae species plus 50 Pseudomonas and 25 Acinetobacter species. A total of 14 antimicrobial agents (depending on the species) were included. The same methodology and reading format were used for M.I.C. Evaluator strips and Etest. Broth microdilution methodology was performed according to CLSI document M07-A8. For the clinical strains, >95% of results were plus or minus one doubling dilution for all species. There were fewer than 5% minor errors, fewer than 3% major errors, and fewer than 1% very major errors. M.I.C. Evaluator strips and Etest often reported higher MICs than the reference broth microdilution method. The M.I.C. Evaluator strips provided results comparable to those of the predicate Etest device and are of value for the accurate testing of MICs for these important pathogens. PMID:22238441
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[Microbiological and epidemiological characteristics of vancomycin-dependent enterococci].
Hwang, Keumrock; Sung, Heungsup; Namgoong, Seung; Yoon, Nam Surp; Kim, Mi-Na
2009-08-01
Vancomycin-dependent enterococci (VDE) are clinically equivalent to vancomycin-resistant enterococci (VRE), but more difficult to detect. This study was purposed to characterize VDE microbiologically and epidemiologically. The patients from whom VDE were detected from April 2007 to March 2008 were investigated. For available isolates, minimal inhibitory concentrations (MICs) of and the levels of dependence on vancomycin and teicoplanin were measured by E test (AB Biodisk, Sweden), and a test for reversion of VDE to non-dependent VRE (NDVRE) and pulsed field gel electrophoresis (PFGE) were performed. Patients' demographic and clinical findings were reviewed via electronic medical records. VDE were recovered from 6 (2.2%) of 272 patients carrying VRE during this study period. All patients were already colonized or infected by VRE and treated with vancomycin for 13 to 107 days. VDE were isolated from pleural fluid (one), urine (four), and stool (one). All isolates carried vanA with vancomycin MICs of >256 microg/mL, but two of them had intermediate susceptibilities to teicoplanin. Because 4 VDE isolates were reverted to NDVRE with single passage, vancomycin dependence was measurable for only two isolates as equal and above 0.064 and 0.5 microg/mL respectively, and was reverted after 5 and 7 passages, respectively. Six VDE isolates showed no related clones in PFGE analysis, and 3 of 4 available pairs of initial VRE isolates and subsequent VDE isolates were identical clones. VDE were not rare and seemed to emerge independently from VRE with a prolonged use of vancomycin. Vancomycin-dependence was reverted within several passages.
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Evaluation of Techniques for Measuring Microbial Hazards in Bathing Waters: A Comparative Study
Schang, Christelle; Henry, Rebekah; Kolotelo, Peter A.; Prosser, Toby; Crosbie, Nick; Grant, Trish; Cottam, Darren; O’Brien, Peter; Coutts, Scott; Deletic, Ana; McCarthy, David T.
2016-01-01
Recreational water quality is commonly monitored by means of culture based faecal indicator organism (FIOs) assays. However, these methods are costly and time-consuming; a serious disadvantage when combined with issues such as non-specificity and user bias. New culture and molecular methods have been developed to counter these drawbacks. This study compared industry-standard IDEXX methods (Colilert and Enterolert) with three alternative approaches: 1) TECTA™ system for E. coli and enterococci; 2) US EPA’s 1611 method (qPCR based enterococci enumeration); and 3) Next Generation Sequencing (NGS). Water samples (233) were collected from riverine, estuarine and marine environments over the 2014–2015 summer period and analysed by the four methods. The results demonstrated that E. coli and coliform densities, inferred by the IDEXX system, correlated strongly with the TECTA™ system. The TECTA™ system had further advantages in faster turnaround times (~12 hrs from sample receipt to result compared to 24 hrs); no staff time required for interpretation and less user bias (results are automatically calculated, compared to subjective colorimetric decisions). The US EPA Method 1611 qPCR method also showed significant correlation with the IDEXX enterococci method; but had significant disadvantages such as highly technical analysis and higher operational costs (330% of IDEXX). The NGS method demonstrated statistically significant correlations between IDEXX and the proportions of sequences belonging to FIOs, Enterobacteriaceae, and Enterococcaceae. While costs (3,000% of IDEXX) and analysis time (300% of IDEXX) were found to be significant drawbacks of NGS, rapid technological advances in this field will soon see it widely adopted. PMID:27213772
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Lessa, SS; Paes, RCS; Santoro, PN; Mauro, RA; Vieira-da-Motta, O
2011-01-01
Antimicrobial resistance of bacteria is a worldwide problem affecting wild life by living with resistant bacteria in the environment. This study presents a discussion of outside factors environment on microflora of feral pigs (Sus scrofa) from Brazilian Pantanal. Animals had samples collected from six different body sites coming from two separated geographic areas, Nhecolandia and Rio Negro regions. With routine biochemical tests and commercial kits 516 bacteria were identified, with 240 Gram-positive, predominantly staphylococci (36) and enterococci (186) strains. Among Gram-negative (GN) bacteria the predominant specimens of Enterobacteriaceae (247) mainly represented by Serratia spp. (105), Escherichia coli (50), and Enterobacter spp. (40) and specimens not identified (7). Antimicrobial susceptibility was tested against 17 drugs by agar diffusion method. Staphylococci were negative to production of enterotoxins and TSST-1, with all strains sensitive towards four drugs and highest resistance toward ampicillin (17%). Enterococci presented the highest sensitivity against vancomycin (98%), ampicillin (94%) and tetracycline (90%), and highest resistance pattern toward oxacillin (99%), clindamycin (83%), and cotrimoxazole (54%). In GN the highest resistance was observed with Serratia marcescens against CFL (98%), AMC (66%) and AMP (60%) and all drugs was most effective against E. coli SUT, TET (100%), AMP, TOB (98%), GEN, CLO (95%), CFO, CIP (93%). The results show a new profile of oxacillin-resistant enterococci from Brazilian feral pigs and suggest a limited residue and spreading of antimicrobials in the environment, possibly because of low anthropogenic impact reflected by the drug susceptibility profile of bacteria isolated. PMID:24031689
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Tyson, Gregory H; Nyirabahizi, Epiphanie; Crarey, Emily; Kabera, Claudine; Lam, Claudia; Rice-Trujillo, Crystal; McDermott, Patrick F; Tate, Heather
2018-01-01
Bacteria of the genus Enterococcus are important human pathogens that are frequently resistant to a number of clinically important antibiotics. They are also used as markers of animal fecal contamination of human foods and are employed as sentinel organisms for tracking trends in resistance to antimicrobials with Gram-positive activity. As part of the National Antimicrobial Resistance Monitoring System (NARMS), we evaluated several retail meat commodities for the presence of enterococci from 2002 to 2014, and we found 92.0% to be contaminated. The majority of isolates were either Enterococcus faecalis (64.0%) or Enterococcus faecium (28.6%), and the antimicrobial resistance of each isolate was assessed by broth microdilution. The resistance prevalences for several drugs, including erythromycin and gentamicin, were significantly higher among poultry isolates, compared to retail beef or pork isolates. None of the isolates was resistant to the clinically important human drug vancomycin, only 1 isolate was resistant to linezolid, and resistance to tigecycline was below 1%. In contrast, a majority of both E. faecalis (67.5%) and E. faecium (53.7%) isolates were resistant to tetracycline. Overall, the robust NARMS testing system employed consistent sampling practices and methods throughout the testing period, with the only significant trend in resistance prevalence being decreased E. faecium resistance to penicillin. These data provide excellent baseline levels of resistance that can be used to measure future changes in resistance prevalence that may result from alterations in the use of antimicrobials in food animal production. IMPORTANCE Enterococci, including E. faecalis and E. faecium , are present in the guts of food-producing animals and are used as a measure of fecal contamination of meat. We used the large consistent sampling methods of NARMS to assess the prevalence of Enterococcus strains isolated from retail meats, and we found over 90% of meats to be contaminated with enterococci. We also assessed the resistance of the Enterococcus strains, commonly used as a measure of resistance to agents with Gram-positive activity, in foods. Resistance prevalence was over 25% for some antimicrobials and sample sources but was less than 1% for several of the most important therapeutic agents used in human medicine. This is a work of the U.S. Government and is not subject to copyright protection in the United States. Foreign copyrights may apply.
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NASA Astrophysics Data System (ADS)
Zepp, R. G.; Molina, M.; Cyterski, M.; Whelan, G.; Parmar, R.; Wolfe, K.; Villegas, E. N.; Corsi, S. R.; Borchardt, M.
2013-12-01
The Great Lakes have over 100 tributaries contributing a variety of pollutants, including pathogens. This loading results in contamination of near coastal sites on the lakes by pathogens and fecal indicator bacteria, such as enterococci. Here, we present data, relationships and modeling tools for evaluating exposure to microorganisms in Lake Michigan near Manitowoc, WI and in the Manitowoc River, a tributary that flows into Lake Michigan at Manitowoc. Increased precipitation and subsequent runoff during a basin-wide storm in June 2011 caused an order of magnitude increase in riverine discharge, a 100-fold increase in enterococci densities and a doubling of colored dissolved organic matter (CDOM) in the river. CDOM is a UV-protective substance that decreases UV inactivation of enterococci and most pathogens. Water samples were collected at four riverine sites including at a USGS gage station with large-volume pathogen sampling equipment, one beach site at Lake Michigan and at a nearby stormwater outflow. Potential sources of microbial contamination include agricultural activities such as manure application and wastewater treatment effluent; therefore, additional samples were collected from the effluent stream of the Manitowoc Wastewater Treatment Facility and manure from spreading trucks. Pathogens measured included Campylobacter jejuni, E. coli O157:H7, Enterovirus - 5' UTR , Adenovirus Groups A , B, C, D, and F, Cryptosporidium spp. and Giardia duodenalis. Meteorological data were also collected at nearby weather stations and water-quality data such as turbidity, temperature, conductivity, and chlorophyll were also measured. Three acoustic doppler current profilers were located between the river mouth and the beach to measure current movements. The data were analyzed using modeling infrastructure technologies (FRAMES, D4EM and SuperMUSE) coupled with hydrodynamic and water quality models (HSPF, WASP, HEC-RAS, FVCOM and MRA-IT) and the Virtual Beach 3.0 statistical tool. Results from the Virtual Beach tool indicated enterococci from the Manitowoc River made an important contribution to densities of this indicator at the beach site. Patterns of pathogens found at the beach and river sites indicated the wastewater treatment plant was the primary source, whereas riverine pathogen concentrations from dairy cattle manure were low, indicating methods of manure application minimized runoff.
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Cahill, Orla J; Claro, Tânia; Cafolla, Attilio A; Stevens, Niall T; Daniels, Stephen; Humphreys, Hilary
2017-10-01
OBJECTIVE To evaluate the efficacy of a multijet cold-plasma system and its efficacy in decontaminating 2 surfaces commonly found in hospitals DESIGN An in vitro study of common causes of healthcare-acquired infection METHODS Log10 9 cultures of methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended spectrum β-lactamase-producing Escherichia coli, and Acinetobacter baumannii were applied to 5-cm2 sections of stainless steel and mattress. Human serum albumin (HSA) was used as a proxy marker for organic material, and atomic force microscopy (AFM) was used to study the impact on bacterial cell structure. The inoculated surfaces were exposed to a cold-air-plasma-generating multijet prototype for 15, 20, 30, and 45 seconds. RESULTS After 45 seconds, at least 3 to 4 log reductions were achieved for all bacteria on the mattress, while 3 to 6 log reductions were observed on stainless steel. The presence of HSA had no appreciable effect on bacterial eradication. The surfaces with bacteria exposed to AFM showed significant morphological changes indicative of "etching" due to the action of highly charged ions produced by the plasma. CONCLUSION This multijet cold-plasma prototype has the potential to augment current environmental decontamination approaches but needs further evaluation in a clinical setting to confirm its effectiveness. Infect Control Hosp Epidemiol 2017;38:1182-1187.
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Hedin, G; Rynbäck, J; Loré, B
2010-06-01
The benefit of routine surface disinfection in hospitals has been discussed. In this study we have investigated a new product, Appeartex. After application on surfaces a remnant effect is achieved due to the positive charge of the active molecule. We studied the persistent effect of Appeartex one day after application in both an experimental study in the laboratory and a field study in a hospital ward. Surfaces of bedside tables were investigated. In the experimental study, large inocula of >or=10(6)cfu of S. aureus or enterococci were inoculated on to well-defined areas which had been treated/not treated with Appeartex. One hour later, samples were taken with a swab rinse technique. A reduction in the number of viable bacteria in the magnitude 10-10(3) cfu was seen due to the effect of Appeartex. In the field study the effect on naturally occurring low level contamination was studied. Defined surfaces on bedside tables used by patients were treated/not treated with Appeartex. One day later, samples were taken with contact agar plates and with a new swab method using two sequential nylon flocked swabs. Significantly fewer bacteria were found on Appeartex-treated surfaces compared with untreated surfaces. The median counts on Appeartex-treated surfaces were 10 cfu/50 cm(2), and on untreated surfaces 20 cfu/50 cm(2). There was no significant difference in the number of bacteria found by culture of samples taken with the contact agar method compared with samples taken using the nylon flocked swab method. (c) 2010 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved.
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Screening candidate water quality indicators for associations with swimming-related illness
ABSTRACT Traditional (culture-based) indicator organisms (e.g. enterococci, fecal and total coliforms) are used to regulate marine beaches for protecting human health. Despite the recent proliferation of new technology, few studies have examined alternatives to this decades...
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Micro CSI: A Microbial Citizen Science Initiative in Urban Watersheds
Across the Nation, a number of citizen science efforts have been conducted to monitor water quality. Efforts have included monitoring of bacteriological parameters (E. coli, enterococci, and fecal coliforms) and/or physicochemical parameters (temperature, turbidity, pH, conducti...
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BACTERIA, BEACHES AND SWIMMABLE WATERS: INTRODUCING VIRTUAL BEACH
Safe beaches meet water quality standards and are valued for their aesthetics and the recreational opportunities that they afford. In the United States recreational water quality assessments and beach closure decisions are presently based on samples of enterococci or Escherichia ...
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PREDICTIVE MODELING OF LIGHT-INDUCED MORTALITY OF ENTEROCOCCI FAECALIS IN RECREATIONAL WATERS
One approach to predictive modeling of biological contamination of recreational waters involves the application of process-based approaches that consider microbial sources, hydrodynamic transport, and microbial fate. This presentation focuses on one important fate process, light-...
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Bartkiene, E; Juodeikiene, G; Vidmantiene, D; Zdunczyk, Z; Zdunczyk, P; Juskiewicz, J; Cizeikiene, D; Matusevicius, P
2013-09-01
The present study proposes the contribution of lactic acid bacteria and plants rich in bioactive substances and high-quality proteins as alternative products for human diets in improving the gut environment as potential against pathogenic bacteria. The effect of diets supplemented with soya, flaxseed and lupine flours fermented with a Pediococcus acidilactici KTU05-7 probiotic strain in the gastrointestinal tract (GIT) of Wistar rats were analyzed. In vivo experiments showed a positive effect of long time lactofermentation of plant material on the body weight of rats. Diets with fermented yellow lupine resulted in enhanced activities of α-glucosidase, β-galactosidases, as well as high levels of lactic acid bacteria, bifidobacteria and enterococci in the GIT were determined. Lactofermentation of analyzed plant products had a significantly lowering effect on Escherichia coli compared with the control group. The dominant flora of large intestines like Bifidobacterium and anaerobic cocci were found in high levels after diets with fermented lupine.
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Fecal Indicator Bacteria and Environmental Observations: Validation of Virtual Beach
Contamination of recreational waters by fecal material is often assessed using indicator bacteria such as enterococci. Enumeration based on culturing methods can take up to 48 hours to complete, limiting the accuracy of water quality evaluations. Molecular microbial techniques em...
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TRANSPORT OF CHEMICAL AND MICROBIAL CONTAMINANTS FROM KNOWN WASTEWATER DISCHARGES
The quality of drinking and recreational water is currently ascertained using indicator bacteria, such as Escherichia coli and fecal enterococci. However, the tests to analyze for these bacteria require a considerable length of time to complete, and do not discriminate between ...
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The current study evaluates the effectiveness of the combined application of Peracetic acid and ultraviolet radiation as alternative disinfectant agents to the traditional chlorination of wastewater effluents. Various pathogens (E. coli, enterococci and fecal coliforms) were eval...
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77 FR 71191 - 2012 Recreational Water Quality Criteria
Federal Register 2010, 2011, 2012, 2013, 2014
2012-11-29
... Criteria AGENCY: Environmental Protection Agency (EPA). ACTION: Notice of availability of the 2012... for beach monitoring, quantitative polymerase chain reaction (qPCR), for the detection of enterococci... managing recreational waters, such as predictive modeling; the EPA is providing a beach action value for...
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Bonjoch, X; García-Aljaro, C; Blanch, A R
2011-07-01
To assess the persistence and diversity of faecal bacterial populations (faecal coliforms and enterococci) that have recently been included in microbial source tracking (MST) predictive models. The analysed bacterial populations included members of the enterococci group (ENT) [Enterococcus faecium (FM), Enterococcus faecalis (FS) and Enterococcus hirae (HIR)] and the faecal coliform group (FC) [diverse Escherichia coli phenotypes (ECP) and cellobiose-negative faecal coliforms (CNFC)]. The inactivation of these distinct groups was monitored over time on-site in river by biochemical fingerprinting, and diversity indices were calculated. Among the different analysed species belonging to the ENT group, HIR persisted longer and was able to replicate in the environment at a higher rate. On the other hand, ECP and NCFC showed a similar persistence throughout the different seasons. The diversity index (Di) for FC increased substantially in the summer after 96 h to a maximum value of 0·96. On the other hand, the Di for ENT diminished over the same period to a value of 0·86, suggesting a different persistence for the different species integrating this group. The persistence of ECP, CNFC, FM and FS in the aquatic environment is high, particularly for the members of the FC and in the summer season. On the contrary, HIR is able to replicate in the environment at a high rate even in winter, and therefore, its inclusion in MST predictive models is discouraged. ECP, CNFC, FMFS and HIR have been proposed as additional variables in MST predictive models. However, the different persistence of HIR compared with the other variables should be taken into account for the development of such models. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.
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Effect of ingestion of soy yogurt on intestinal parameters of rats fed on a beef-based animal diet
Bedani, Raquel; Pauly-Silveira, Nadiége Dourado; Cano, Veridiana Soares Pereira; Valentini, Sandro Roberto; de Rossi, Graciela Font; Valdez, Elizeu Antonio
2011-01-01
The aim of this study was to investigate whether the ingestion of soy yogurt fermented with Enterococcus faecium CRL 183 would modify the intestinal count of enterococci, fecal pH and ammonia content in rats fed on a diet containing red meat. The rats were placed in 4 groups: for 60 days, group I was given a standard casein-based rodent feed and groups II-IV, the beef-based feed. From day 30, groups III-IV also received the following products: III) soy yogurt; IV) suspension of E. faecium CRL 183. At the start and on days 30 and 60, feces were collected for the determination of pH, ammonia content, count of enterococci and identification of their species. On day 60, rats were sacrificed and their colons also removed for count of enterococci and identification of their species. Rats that ingested soy yogurt showed no significant change (P<0.05) in fecal counts of Enterococcus spp., but, this rat group showed a higher count of E. faecium than rats that ingested suspension of E. faecium CRL 183. The ingestion of soy yogurt and E. faecium culture caused a significant rise (P < 0.05) in fecal pH and ammonia content. Our results suggest that consumption of soy yogurt fermented with E. faecium CRL 183 and L. helveticus subsp. jugurti could change the species of Enterococcus spp. present in the feces and colon of rats fed on a beef-based diet. However, the fermented soy product and the pure culture of E. faecium CRL 183 also induced undesirable effects such as the increase of fecal pH and ammonia content in the feces of rats fed on a beef-based diet. PMID:24031747
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Khani, Mitra; Fatollahzade, Mahdie; Pajavand, Hamid; Bakhtiari, Somaye; Abiri, Ramin
2016-03-01
Enterococci are important pathogens in nosocomial infections. Various types of antibiotics, such as aminoglycosides, are used for treatment of these infections. Enterococci can acquire resistant traits, which can lead to therapeutic problems with aminoglycosides. This study was designed to identify the prevalence of, and to compare, the aac(6')-aph(2") and aph(3)-IIIa genes and their antimicrobial resistance patterns among Enterococcus faecalis and E. faecium isolates from patients at Imam Reza hospital in Kermanshah in 2011 - 2012. One hundred thirty-eight clinical specimens collected from different wards of Imam Reza hospital were identified to the species level by biochemical tests. Antimicrobial susceptibility tests against kanamycin, teicoplanin, streptomycin, imipenem, ciprofloxacin, and ampicillin were performed by the disk diffusion method. The minimum inhibitory concentrations of gentamicin, streptomycin, kanamycin, and amikacin were evaluated with the microbroth dilution method. The aminoglycoside resistance genes aac(6')-aph(2") and aph(3")-IIIa were analyzed with multiplex PCR. The prevalence of isolates was 33 (24.1%) for E. faecium and 63 (46%) for E. faecalis. Eighty-nine percent of the isolates were high-level gentamicin resistant (HLGR), and 32.8% of E. faecium isolates and 67.2% of E. faecalis isolates carried aac(6')-aph(2"). The prevalence of aph(3")-IIIa among the E. faecalis and E. faecium isolates was 22.7% and 77.3%, respectively. Remarkably increased incidence of aac(6')-aph(2") among HLGR isolates explains the relationship between this gene and the high level of resistance to aminoglycosides. As the resistant gene among enterococci can be transferred, the use of new-generation antibiotics is necessary.
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Khani, Mitra; Fatollahzade, Mahdie; Pajavand, Hamid; Bakhtiari, Somaye; Abiri, Ramin
2016-01-01
Background: Enterococci are important pathogens in nosocomial infections. Various types of antibiotics, such as aminoglycosides, are used for treatment of these infections. Enterococci can acquire resistant traits, which can lead to therapeutic problems with aminoglycosides. Objectives: This study was designed to identify the prevalence of, and to compare, the aac(6’)-aph(2”) and aph(3)-IIIa genes and their antimicrobial resistance patterns among Enterococcus faecalis and E. faecium isolates from patients at Imam Reza hospital in Kermanshah in 2011 - 2012. Patients and Methods: One hundred thirty-eight clinical specimens collected from different wards of Imam Reza hospital were identified to the species level by biochemical tests. Antimicrobial susceptibility tests against kanamycin, teicoplanin, streptomycin, imipenem, ciprofloxacin, and ampicillin were performed by the disk diffusion method. The minimum inhibitory concentrations of gentamicin, streptomycin, kanamycin, and amikacin were evaluated with the microbroth dilution method. The aminoglycoside resistance genes aac(6’)-aph(2”) and aph(3”)-IIIa were analyzed with multiplex PCR. Results: The prevalence of isolates was 33 (24.1%) for E. faecium and 63 (46%) for E. faecalis. Eighty-nine percent of the isolates were high-level gentamicin resistant (HLGR), and 32.8% of E. faecium isolates and 67.2% of E. faecalis isolates carried aac(6’)-aph(2”). The prevalence of aph(3”)-IIIa among the E. faecalis and E. faecium isolates was 22.7% and 77.3%, respectively. Conclusions: Remarkably increased incidence of aac(6’)-aph(2”) among HLGR isolates explains the relationship between this gene and the high level of resistance to aminoglycosides. As the resistant gene among enterococci can be transferred, the use of new-generation antibiotics is necessary. PMID:27217920
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Samelis, John; Lianou, Alexandra; Kakouri, Athanasia; Delbès, Céline; Rogelj, Irena; Bogovic-Matijasić, Bojana; Montel, Marie-Christine
2009-04-01
The microbiological quality, safety, and composition of mixtures of ewe's and goat's milk (90:10) used for cheesemaking were evaluated before and after thermization at 60 and 67 degrees C for 30 s. Such mild thermal treatments are commonly applied to reduce natural contaminants of raw milk before processing for traditional hard Greek cheeses. Raw milk samples had an average total bacterial count of 7.3 log CFU/ml; most of these bacteria were lactic acid bacteria (LAB) and pseudomonads. The LAB flora of raw milk was dominated by enterococci (40.8%), followed by lactococci (20.4%), leuconostocs (18.4%), and mesophilic lactobacilli (10.2%). Enterococcus faecalis (30.1%) and Enterococcus faecium (13.7%) were the most common LAB isolates, followed by Enterococcus durans, Lactococcus lactis subsp. lactis, Lactobacillus plantarum, and Leuconostoc lactis. Thermization at 60 degrees C for 30 s was effective for reducing raw milk contamination by enterobacteria (5.1 log CFU/ml), coagulase-positive staphylococci (3.3 log CFU/ml), and Listeria (present in 25-ml samples) to safe levels, but it also reduced mesophilic lactococci, leuconostocs, lactobacilli, and selected enterococci (72.0%) in thermized milk. Thermization at 67 degrees C for 30 s had a major inactivation effect on all bacterial groups. Two nisin-producing L. lactis subsp. lactis strains (M78 and M104) were isolated from raw milk, but neither nisin-producing nor other bacteriocin-producing LAB strains were isolated from thermized milk. Thus, thermization treatments control harmful bacteria but also may have a negative impact on milk quality by reducing desirable LAB and the biodiversity of raw milk bacteria overall, inactivating potentially protective LAB strains and enhancing the ability of potentially pathogenic enterococci to grow in fresh cheese curds.
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Castillo-Rojas, Gonzalo; Mazari-Hiríart, Marisa; Ponce de León, Sergio; Amieva-Fernández, Rosa I; Agis-Juárez, Raúl A; Huebner, Johannes; López-Vidal, Yolanda
2013-01-01
Enterococci are part of the normal intestinal flora in a large number of mammals, and these microbes are currently used as indicators of fecal contamination in water and food for human consumption. These organisms are considered one of the primary causes of nosocomial and environmental infections due to their ability to survive in the environment and to their intrinsic resistance to antimicrobials. The aims of this study were to determine the biochemical patterns and antimicrobial susceptibilities of Enterococcus faecalis and E. faecium isolates from clinical samples and from water (groundwater, water from the Xochimilco wetland, and treated water from the Mexico City Metropolitan Area) and to determine the genetic relationships among these isolates. A total of 121 enterococcus strains were studied; 31 and 90 strains were isolated from clinical samples and water (groundwater, water from the Xochimilco wetland, and water for agricultural irrigation), respectively. Identification to the species level was performed using a multiplex PCR assay, and antimicrobial profiles were obtained using a commercial kit. Twenty-eight strains were analyzed by pulsed-field gel electrophoresis (PFGE). E. faecium strains isolated from water showed an atypical biochemical pattern. The clinical isolates showed higher resistance to antibiotics than those from water. Both the enterococci isolated from humans, and those isolated from water showed high genetic diversity according to the PFGE analysis, although some strains seemed to be closely related. In conclusion, enterococci isolated from humans and water are genetically different. However, water represents a potential route of transmission to the community and a source of antimicrobial resistance genes that may be readily transmitted to other, different bacterial species.
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Comparative genomics of Enterococcus spp. isolated from bovine feces.
Beukers, Alicia G; Zaheer, Rahat; Goji, Noriko; Amoako, Kingsley K; Chaves, Alexandre V; Ward, Michael P; McAllister, Tim A
2017-03-08
Enterococcus is ubiquitous in nature and is a commensal of both the bovine and human gastrointestinal (GI) tract. It is also associated with clinical infections in humans. Subtherapeutic administration of antibiotics to cattle selects for antibiotic resistant enterococci in the bovine GI tract. Antibiotic resistance genes (ARGs) may be present in enterococci following antibiotic use in cattle. If located on mobile genetic elements (MGEs) their dissemination between Enterococcus species and to pathogenic bacteria may be promoted, reducing the efficacy of antibiotics. We present a comparative genomic analysis of twenty-one Enterococcus spp. isolated from bovine feces including Enterococcus hirae (n = 10), Enterococcus faecium (n = 3), Enterococcus villorum (n = 2), Enterococcus casseliflavus (n = 2), Enterococcus faecalis (n = 1), Enterococcus durans (n = 1), Enterococcus gallinarum (n = 1) and Enterococcus thailandicus (n = 1). The analysis revealed E. faecium and E. faecalis from bovine feces share features with human clinical isolates, including virulence factors. The Tn917 transposon conferring macrolide-lincosamide-streptogramin B resistance was identified in both E. faecium and E. hirae, suggesting dissemination of ARGs on MGEs may occur in the bovine GI tract. An E. faecium isolate was also identified with two integrative conjugative elements (ICEs) belonging to the Tn916 family of ICE, Tn916 and Tn5801, both conferring tetracycline resistance. This study confirms the presence of enterococci in the bovine GI tract possessing ARGs on MGEs, but the predominant species in cattle, E. hirae is not commonly associated with infections in humans. Analysis using additional complete genomes of E. faecium from the NCBI database demonstrated differential clustering of commensal and clinical isolates, suggesting that these strains may be specifically adapted to their respective environments.
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Clinical accuracy of point-of-care urine culture in general practice.
Holm, Anne; Cordoba, Gloria; Sørensen, Tina Møller; Jessen, Lisbeth Rem; Frimodt-Møller, Niels; Siersma, Volkert; Bjerrum, Lars
2017-06-01
To assess the clinical accuracy (sensitivity (SEN), specificity (SPE), positive predictive value and negative predictive value) of two point-of-care (POC) urine culture tests for the identification of urinary tract infection (UTI) in general practice. Prospective diagnostic accuracy study comparing two index tests (Flexicult™ SSI-Urinary Kit or ID Flexicult™) with a reference standard (urine culture performed in the microbiological department). General practice in the Copenhagen area patients. Adult female patients consulting their general practitioner with suspected uncomplicated, symptomatic UTI. (1) Overall accuracy of POC urine culture in general practice. (2) Individual accuracy of each of the two POC tests in this study. (3) Accuracy of POC urine culture in general practice with enterococci excluded, since enterococci are known to multiply in boric acid used for transportation for the reference standard. (4) Accuracy based on expert reading of photographs of POC urine cultures performed in general practice. Standard culture performed in the microbiological department was used as reference standard for all four measures. Twenty general practices recruited 341 patients with suspected uncomplicated UTI. The overall agreement between index test and reference was 0.76 (CI: 0.71-0.80), SEN 0.88 (CI: 0.83-0.92) and SPE 0.55 (CI: 0.46-0.64). The two POC tests produced similar results individually. Overall agreement with enterococci excluded was 0.82 (0.77-0.86) and agreement between expert readings of photographs and reference results was 0.81 (CI: 0.76-0.85). POC culture used in general practice has high SEN but low SPE. Low SPE could be due to both misinterpretation in general practice and an imperfect reference standard. Registration number: ClinicalTrials.gov NCT02323087.
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Castillo-Rojas, Gonzalo; Mazari-Hiríart, Marisa; Ponce de León, Sergio; Amieva-Fernández, Rosa I.; Agis-Juárez, Raúl A.; Huebner, Johannes; López-Vidal, Yolanda
2013-01-01
Enterococci are part of the normal intestinal flora in a large number of mammals, and these microbes are currently used as indicators of fecal contamination in water and food for human consumption. These organisms are considered one of the primary causes of nosocomial and environmental infections due to their ability to survive in the environment and to their intrinsic resistance to antimicrobials. The aims of this study were to determine the biochemical patterns and antimicrobial susceptibilities of Enterococcus faecalis and E. faecium isolates from clinical samples and from water (groundwater, water from the Xochimilco wetland, and treated water from the Mexico City Metropolitan Area) and to determine the genetic relationships among these isolates. A total of 121 enterococcus strains were studied; 31 and 90 strains were isolated from clinical samples and water (groundwater, water from the Xochimilco wetland, and water for agricultural irrigation), respectively. Identification to the species level was performed using a multiplex PCR assay, and antimicrobial profiles were obtained using a commercial kit. Twenty-eight strains were analyzed by pulsed-field gel electrophoresis (PFGE). E. faecium strains isolated from water showed an atypical biochemical pattern. The clinical isolates showed higher resistance to antibiotics than those from water. Both the enterococci isolated from humans, and those isolated from water showed high genetic diversity according to the PFGE analysis, although some strains seemed to be closely related. In conclusion, enterococci isolated from humans and water are genetically different. However, water represents a potential route of transmission to the community and a source of antimicrobial resistance genes that may be readily transmitted to other, different bacterial species. PMID:23560050
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Mauffret, Aourell; Caprais, Marie-Paule
2012-01-01
The relevance of three host-associated Bacteroidales markers (HF183, Rum2Bac, and Pig2Bac) and four F-specific RNA bacteriophage genogroups (FRNAPH I to IV) as microbial source tracking markers was assessed at the level of a catchment (Daoulas, France). They were monitored together with fecal indicators (Escherichia coli and enterococci) and chemophysical parameters (rainfall, temperature, salinity, pH, and turbidity) by monthly sampling over 2 years (n = 240 water samples) and one specific sampling following an accidental pig manure spillage (n = 5 samples). During the 2-year regular monitoring, levels of E. coli, enterococci, total F-specific RNA bacteriophages, and the general Bacteroidales marker AllBac were strongly correlated with one another and with Rum2Bac (r = 0.37 to 0.50, P < 0.0001). Their correlations with HF183 and FRNAPH I and II were lower (r = 0.21 to 0.29, P < 0.001 to P < 0.0001), and HF183 and enterococci were associated rather than correlated (Fisher's exact test, P < 0.01). Rum2Bac and HF183 enabled 73% of water samples that had ≥2.7 log10 most probably number (MPN) of E. coli/100 ml to be classified. FRNAPH I and II enabled 33% of samples at this contamination level to be classified. FRNAPH I and II complemented the water sample classification obtained with the two Bacteroidales markers by an additional 8%. Pig2Bac and FRNAPH III and IV were observed in a small number of samples (n = 0 to 4 of 245). The present study validates Rum2Bac and HF183 as relevant tools to trace fecal contamination originating from ruminant or human waste, respectively, at the level of a whole catchment. PMID:22610433
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Karra, Styliani; Katsivela, Eleftheria
2007-03-01
Measurements were conducted at a Mediterranean site (latitude 35 degrees 31' north and longitude 24 degrees 03' east) during summer, to study the concentration of microorganisms emitted from a wastewater treatment plant under intensive solar radiation (520-840 W/m2) and at elevated air temperatures (25-31 degrees C). Air samples were taken with the Air Sampler MAS 100 (Merck) at each stage of an activated-sludge wastewater treatment (pretreatment, primary settling tanks, aeration tanks, secondary settling tanks, chlorination, and sludge processors). Cultivation methods based on the viable counts of mesophilic heterotrophic bacteria, as well as of indicator microorganisms of faecal contamination (total and faecal coliforms and enterococci), and fungi were performed. During air sampling, temperature, solar radiation, relative humidity and wind speed were measured. The highest concentrations of airborne microorganisms were observed at the aerated grit removal of wastewater at the pretreatment stage. A gradual decrease of bioaerosol emissions was observed during the advanced wastewater treatment from the pretreatment to the primary, secondary and tertiary treatment (97.4% decrease of mesophilic heterotrophic bacteria, and 100% decrease of total coliforms, faecal coliforms and enterococci), 95.8% decrease of fungi. The concentration of the airborne microorganisms at the secondary and tertiary treatment of the wastewater was lower than in the outdoor control. At the same time, the reduction of the microbial load at the waste sludge processors was 19.7% for the mesophilic heterotrophic bacteria, 99.4% for the total coliforms, and 100% for the faecal coliforms and the enterococci, 84.2% for the fungi. The current study concludes that the intensive solar radiation, together with high ambient temperatures, as well as optimal wastewater treatment are the most important factors for low numbers of microbes in the air.
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Noble, M A; Xu, J P; Robertson, G L; Rosenfeld, L K
2006-06-01
Fecal indicator bacteria (FIB) were measured approximately 5 days a week in ankle-depth water at 19 surfzone stations along Huntington Beach and Newport Beach, California, from 1998 to the end of 2003. These sampling periods span the time before and after treated sewage effluent, discharged into the coastal ocean from the local outfall, was disinfected. Bacterial samples were also taken in the vicinity of the outfall during the pre- and post-disinfection periods. Our analysis of the results from both data sets suggest that land-based sources, rather than the local outfall, were the source of the FIB responsible for the frequent closures and postings of local beaches in the summers of 2001 and 2002. Because the annual cycle is the dominant frequency in the fecal and total coliform data sets at most sampling stations, we infer that sources associated with local runoff were responsible for the majority of coliform contamination along wide stretches of the beach. The dominant fortnightly cycle in enterococci at many surfzone sampling stations suggests that the source for these relatively frequent bacteria contamination events in summer is related to the wetting and draining of the land due to the large tidal excursions found during spring tides. Along the most frequently closed section of the beach at stations 3N-15N, the fortnightly cycle is dominant in all FIBs. The strikingly different spatial and spectral patterns found in coliform and in enterococci suggest the presence of different sources, at least for large sections of beach. The presence of a relatively large enterococci fortnightly cycle along the beaches near Newport Harbor indicates that contamination sources similar to those found off Huntington Beach are present, though not at high enough levels to close the Newport beaches.
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On-farm and postharvest processing sources of bacterial contamination to melon rinds.
Gagliardi, J V; Millner, P D; Lester, G; Ingram, D
2003-01-01
Multistate and international foodborne illness outbreaks, particularly involving cantaloupe and often involving rare Salmonella spp., have increased dramatically over the past 13 years. This study assessed the sources and extent of melon rind contamination in production fields and at processing and packing facilities. In the spring of 1999, cantaloupe (Cucumis melo L. [reticulatus group] cv. Cruiser) sampled from two sites in the Rio Grande River Valley showed that postharvest-processed melon rinds often had greater plate counts of bacterial contaminants than field-fresh melons. Cantaloupe in the field had 2.5 to 3.5 log CFU g(-1) rind total coliforms by aerobic plate counts, whereas washed melons had 4.0 to 5.0 log CFU g(-1). In the fall of 1999, coliforms on honeydew melons (C. melo [inodorous group] cv. Honey Brew) ranged from 2.6 to 3.7 log CFU g(-1) after processing, and total and fecal coliforms and enterococci never fell below 2.5 log CFU g(-1). A hydrocooler at another site contaminated cantaloupe rinds with up to 3.4 log CFU g(-1) total and fecal enterococci; a secondary rinse with chlorinated water incompletely removed these bacteria. Sources of coliforms and enterococci were at high levels in melon production soils, especially in furrows that were flood irrigated, in standing water at one field, and in irrigation water at both sites. At one processing facility, wash water pumped from the Rio Grande River may not have been sufficiently disinfected prior to use. Because soil, irrigation water, and process water were potential sources of bacterial contamination, monitoring and management on-farm and at processing and packing facilities should focus on water quality as an important control point for growers and packers to reduce bacterial contamination on melon rinds.
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Evaluation of different primers for PCR-DGGE analysis of cheese-associated enterococci.
Lorbeg, Petra Mohar; Majhenic, Andreja Canzek; Rogelj, Irena
2009-08-01
Enterococci represent an important part of bacterial microbiota in different types of artisanal cheeses, made from either raw or pasteurized milk. Polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) of ribosomal DNA is currently one of the most frequently used fingerprinting method to study diversity and dynamics of microbial communities and also a tool for microbial identification. Among several primer pairs for DGGE analysis published so far, six primer pairs amplifying different variable regions of 16S rDNA were selected and applied in our DGGE analysis of 12 species belonging to genus Enterococcus and eight other bacterial species often found in cheeses (seven lactobacilli and one Lactoccocus lactis). When DGGE procedures were optimized, the same set of primers was used for DGGE analysis of five cheese samples. Our study demonstrates that the use of different primer pairs generate significant differences in DGGE analysis of enterococcal population, consequently, appropriate primers regarding the purpose of analysis can be selected. For differentiation and identification of pure enterococcal isolates, primer pair P1V1/P2V1 showed the most promising results since all 12 enterococcal isolates gave distinctive DGGE fingerprints, but with multiple bands patterns; therefore, these primers do not seem to be appropriate for identification of enterococcal species in mixed cultures. Use of primer pairs HDA1/HDA2 and V3f/V3r amplifying V3 region showed better potential for detection and identification of enterococci in mixed communities, but since some bacterial species showed the same fingerprint, for clear identification combination of DGGE and some other method (e.g. species specific PCR) or combined DGGE analysis using two primer pairs generating distinctive results should be used.
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Jahan, M; Holley, R A
2016-04-01
Listeria monocytogenes is an important foodborne pathogen that can cause infection in children, pregnant women, the immunocompromised and the elderly. Antibiotic resistance in this species would represent a significant public health problem since the organism has a high fatality/case ratio and resistance may contribute to failure of therapeutic treatment. This study was designed to explore whether the in vitro transferability of antibiotic resistance from enterococci to Listeria spp. could occur. It was found that 2/8 Listeria strains were able to acquire tetracycline resistance from Enterococcus faecium. Listeria monocytogenes GLM-2 acquired the resistance determinant tet(M) and additional streptomycin resistance through in vitro mating with Ent. faecium S27 isolated from commercial fermented dry sausage. Similarly, Listeria innocua became more resistant to tetracycline, but the genetic basis for this change was not confirmed. It has been suggested that enterococci may transfer antibiotic resistance genes via transposons to Listeria spp., and this may explain, in part, the origin of their antibiotic resistance. Thus, the presence of enterococci in food should not be ignored since they may actively contribute to enhanced antibiotic resistance of L. monocytogenes and other pathogens. Acquisition of antibiotic resistance by pathogenic bacteria in the absence of antibiotic pressure represents an unquantified threat to human health. In the present work resistance to tetracycline and streptomycin were transferred by nonplasmid-based conjugation from Enterococcus faecium isolated from fermented sausage to Listeria monocytogenes and Listeria innocua. Thus, natural transfer of antibiotic resistance to Listeria strains may occur in the future which reinforces the concern about the safety of enterococcal strains present in foods. © 2016 The Society for Applied Microbiology.
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Yamahara, Kevan M.; Sassoubre, Lauren M.; Goodwin, Kelly D.
2012-01-01
This report documents the presence of fecal indicators and bacterial pathogens in sand at 53 California marine beaches using both culture-dependent and -independent (PCR and quantitative PCR [QPCR]) methods. Fecal indicator bacteria were widespread in California beach sand, with Escherichia coli and enterococci detected at 68% and 94% of the beaches surveyed, respectively. Somatic coliphages and a Bacteroidales human-specific fecal marker were detected at 43% and 13% of the beaches, respectively. Dry sand samples from almost 30% of the beaches contained at least one of the following pathogens: Salmonella spp., Campylobacter spp., Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus (MRSA), which were detected at 15%, 13%, 14%, and 3% of tested beaches, respectively. Fecal indicators and pathogens were poorly correlated to one another and to land cover. Sands were dry at the time of collection, and those with relatively high moisture tended to have higher concentrations or a more frequent occurrence of both indicators and pathogens. Using culture-dependent assays, fecal indicators decayed faster than pathogens in microcosm experiments using unaltered beach sand seeded with sewage and assessed by culture-dependent assays. The following order of persistence was observed (listed from most to least persistent): Campylobacter > Salmonella > somatic coliphages > enterococci > E. coli > F+ phages. In contrast, pathogens decayed faster than fecal indicators in culture-independent assays: enterococci > Bacteroidales human-specific marker > Salmonella > Campylobacter. Microcosm experiments demonstrated that both indicators and pathogens were mobilized by wetting with seawater. Decay rates measured by QPCR were lower than those measured with culture-dependent methods. Enterococcal persistence and possible growth were observed for wetted microcosms relative to unwetted controls. PMID:22247142
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Deshpande, Abhishek; Hurless, Kelly; Cadnum, Jennifer L.; Chesnel, Laurent; Gao, Lihong; Chan, Luisa; Kundrapu, Sirisha; Polinkovsky, Alexander
2016-01-01
Surotomycin (formerly called CB-183,315) is a novel, orally administered cyclic lipopeptide antibacterial in development for the treatment of Clostridium difficile infection (CDI) that has potent activity against vancomycin-resistant enterococci (VRE) but limited activity against Gram-negative bacilli, including Bacteroides spp. We used a mouse model to investigate the impact of surotomycin exposure on the microbiome, and to test the consequences of the disruption on colonization by vancomycin-resistant enterococci (VRE) and extended-spectrum β-lactamase-producing Klebsiella pneumoniae (ESBL-KP), in comparison with the effects of oral vancomycin and metronidazole. Mice (8 per group) received saline, vancomycin, metronidazole, or surotomycin through an orogastric tube daily for 5 days and were challenged with 105 CFU of VRE or ESBL-KP administered through an orogastric tube on day 2 of treatment. The concentrations of the pathogens in stool were determined during and after treatment by plating on selective media. A second experiment was conducted to determine if the antibiotics would inhibit established VRE colonization. In comparison to controls, oral vancomycin promoted VRE and ESBL-KP overgrowth in stool (8 log10 to 10 log10 CFU/g; P < 0.001), whereas metronidazole did not (<4 log10 CFU/g; P > 0.5). Surotomycin promoted ESBL-KP overgrowth (>8 log10 CFU/g; P, <0.001 for comparison with saline controls) but not VRE overgrowth. Surotomycin suppressed preexisting VRE colonization, whereas metronidazole and vancomycin did not. These results suggest that treatment of CDI with surotomycin could reduce levels of VRE acquisition and overgrowth from those with agents such as vancomycin and metronidazole. However, surotomycin and vancomycin may promote colonization by antibiotic-resistant Gram-negative bacilli. PMID:26976870
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Bortolaia, V; Espinosa-Gongora, C; Guardabassi, L
2016-02-01
Enterococci and staphylococci are frequent contaminants on poultry meat. Enterococcus faecalis, Enterococcus faecium and Staphylococcus aureus are also well-known aetiological agents of a wide variety of infections resulting in major healthcare costs. This review provides an overview of the human health risks associated with the occurrence of these opportunistic human pathogens on poultry meat with particular focus on the risk of food-borne transmission of antimicrobial resistance. In the absence of conclusive evidence of transmission, this risk was inferred using data from scientific articles and national reports on prevalence, bacterial load, antimicrobial resistance and clonal distribution of these three species on poultry meat. The risks associated with ingestion of antimicrobial-resistant enterococci of poultry origin comprise horizontal transfer of resistance genes and transmission of multidrug-resistant E. faecalis lineages such as sequence type ST16. Enterococcus faecium lineages occurring in poultry meat products are distantly related to those causing hospital-acquired infections but may act as donors of quinupristin/dalfopristin resistance and other resistance determinants of clinical interest to the human gut microbiota. Ingestion of poultry meat contaminated with S. aureus may lead to food poisoning. However, antimicrobial resistance in the toxin-producing strains does not have clinical implications because food poisoning is not managed by antimicrobial therapy. Recently methicillin-resistant S. aureus of livestock origin has been reported on poultry meat. In theory handling or ingestion of contaminated meat is a potential risk factor for colonization by methicillin-resistant S. aureus. However, this risk is presently regarded as negligible by public health authorities. Copyright © 2015 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
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Fogarty, Lisa R.; Duris, Joseph W.; Crowley, Suzanne L.; Hardigan, Nicole
2007-01-01
Water samples collected from 20 stream sites in Oakland and Macomb Counties, Mich., were analyzed to learn more about the occurrence of cephalosporin-resistant Escherichia coli (E. coli) and vancomycin-resistant enterococci (VRE) and the co-occurrence of antibiotics and mercury in area streams. Fecal indicator bacteria concentrations exceeded the Michigan recreational water-quality standard of 300 E. coli colony forming units (CFU) per 100 milliliters of water in 19 of 35 stream-water samples collected in Oakland County. A gene commonly associated with enterococci from humans was detected in samples from Paint Creek at Rochester and Evans Ditch at Southfield, indicating that human fecal waste is a possible source of fecal contamination at these sites. E. coli resistant to the cephalosporin antibiotics (cefoxitin and/ or ceftriaxone) were found at all sites on at least one occasion. The highest percentages of E. coli isolates resistant to cefoxitin and ceftriaxone were 71 percent (Clinton River at Auburn Hills) and 19 percent (Sashabaw Creek near Drayton Plains), respectively. Cephalosporin-resistant E. coli was detected more frequently in samples from intensively urbanized or industrialized areas than in samples from less urbanized areas. VRE were not detected in any sample collected in this study. Multiple antibiotics (azithromycin, erythromycin, ofloxacin, sulfamethoxazole, and trimethoprim) were detected in water samples from the Clinton River at Auburn Hills, and tylosin (an antibiotic used in veterinary medicine and livestock production that belongs to the macrolide group, along with erythromycin) was detected in one water sample from Paint Creek at Rochester. Concentrations of total mercury were as high as 19.8 nanograms per liter (Evans Ditch at Southfield). There was no relation among percentage of antibiotic-resistant bacteria and measured concentrations of antibiotics or mercury in the water. Genetic elements capable of exchanging multiple antibiotic-resistance genes (class I integrons) were detected in several samples, indicating that the resistance carried by these organisms may be transferable to other bacteria, including disease-causing bacteria.
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Microbial quality of agricultural water in Central Florida
Topalcengiz, Zeynal; Strawn, Laura K.
2017-01-01
The microbial quality of water that comes into the edible portion of produce is believed to directly relate to the safety of produce, and metrics describing indicator organisms are commonly used to ensure safety. The US FDA Produce Safety Rule (PSR) sets very specific microbiological water quality metrics for agricultural water that contacts the harvestable portion of produce. Validation of these metrics for agricultural water is essential for produce safety. Water samples (500 mL) from six agricultural ponds were collected during the 2012/2013 and 2013/2014 growing seasons (46 and 44 samples respectively, 540 from all ponds). Microbial indicator populations (total coliforms, generic Escherichia coli, and enterococci) were enumerated, environmental variables (temperature, pH, conductivity, redox potential, and turbidity) measured, and pathogen presence evaluated by PCR. Salmonella isolates were serotyped and analyzed by pulsed-field gel electrophoresis. Following rain events, coliforms increased up to 4.2 log MPN/100 mL. Populations of coliforms and enterococci ranged from 2 to 8 and 1 to 5 log MPN/100 mL, respectively. Microbial indicators did not correlate with environmental variables, except pH (P<0.0001). The invA gene (Salmonella) was detected in 26/540 (4.8%) samples, in all ponds and growing seasons, and 14 serotypes detected. Six STEC genes were detected in samples: hly (83.3%), fliC (51.8%), eaeA (17.4%), rfbE (17.4%), stx-I (32.6%), stx-II (9.4%). While all ponds met the PSR requirements, at least one virulence gene from Salmonella (invA-4.8%) or STEC (stx-I-32.6%, stx-II-9.4%) was detected in each pond. Water quality for tested agricultural ponds, below recommended standards, did not guarantee the absence of pathogens. Investigating the relationships among physicochemical attributes, environmental factors, indicator microorganisms, and pathogen presence allows researchers to have a greater understanding of contamination risks from agricultural surface waters in the field. PMID:28399144
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Enterococcus phages as potential tool for identifying sewage inputs in the Great Lakes region
Vijayavel, K.; Byappanahalli, Muruleedhara N.; Whitman, Richard L.; Ebdon, J.; Taylor, H.; Kashian, D.R.
2014-01-01
Bacteriophages are viruses living in bacteria that can be used as a tool to detect fecal contamination in surface waters around the world. However, the lack of a universal host strain makes them unsuitable for tracking fecal sources. We evaluated the suitability of two newly isolated Enterococcus host strains (ENT-49 and ENT-55) capable for identifying sewage contamination in impacted waters by targeting phages specific to these hosts. Both host strains were isolated from wastewater samples and identified as E. faecium by 16S rRNA gene sequencing. Occurrence of Enterococcus phages was evaluated in sewage samples (n = 15) from five wastewater treatment plants and in fecal samples from twenty-two species of wild and domesticated animals (individual samples; n = 22). Levels of Enterococcus phages, F + coliphages, Escherichia coli and enterococci were examined from four rivers, four beaches, and three harbors. Enterococcus phages enumeration was at similar levels (Mean = 6.72 Log PFU/100 mL) to F + coliphages in all wastewater samples, but were absent from all non-human fecal sources tested. The phages infecting Enterococcus spp. and F + coliphages were not detected in the river samples (detection threshold < 10 PFU/100 mL), but were present in the beach and harbor samples (range = 1.83 to 2.86 Log PFU/100 mL). Slightly higher concentrations (range = 3.22 to 3.69 Log MPN/100 mL) of E. coli and enterococci when compared to F + coliphages and Enterococcus phages, were observed in the river, beach and harbor samples. Our findings suggest that the bacteriophages associated with these particular Enterococcus host strains offer potentially sensitive and human-source specific indicators of enteric pathogen risk.
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Microbial quality of agricultural water in Central Florida.
Topalcengiz, Zeynal; Strawn, Laura K; Danyluk, Michelle D
2017-01-01
The microbial quality of water that comes into the edible portion of produce is believed to directly relate to the safety of produce, and metrics describing indicator organisms are commonly used to ensure safety. The US FDA Produce Safety Rule (PSR) sets very specific microbiological water quality metrics for agricultural water that contacts the harvestable portion of produce. Validation of these metrics for agricultural water is essential for produce safety. Water samples (500 mL) from six agricultural ponds were collected during the 2012/2013 and 2013/2014 growing seasons (46 and 44 samples respectively, 540 from all ponds). Microbial indicator populations (total coliforms, generic Escherichia coli, and enterococci) were enumerated, environmental variables (temperature, pH, conductivity, redox potential, and turbidity) measured, and pathogen presence evaluated by PCR. Salmonella isolates were serotyped and analyzed by pulsed-field gel electrophoresis. Following rain events, coliforms increased up to 4.2 log MPN/100 mL. Populations of coliforms and enterococci ranged from 2 to 8 and 1 to 5 log MPN/100 mL, respectively. Microbial indicators did not correlate with environmental variables, except pH (P<0.0001). The invA gene (Salmonella) was detected in 26/540 (4.8%) samples, in all ponds and growing seasons, and 14 serotypes detected. Six STEC genes were detected in samples: hly (83.3%), fliC (51.8%), eaeA (17.4%), rfbE (17.4%), stx-I (32.6%), stx-II (9.4%). While all ponds met the PSR requirements, at least one virulence gene from Salmonella (invA-4.8%) or STEC (stx-I-32.6%, stx-II-9.4%) was detected in each pond. Water quality for tested agricultural ponds, below recommended standards, did not guarantee the absence of pathogens. Investigating the relationships among physicochemical attributes, environmental factors, indicator microorganisms, and pathogen presence allows researchers to have a greater understanding of contamination risks from agricultural surface waters in the field.
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Code of Federal Regulations, 2011 CFR
2011-01-01
... accordance with §§ 58.336 and 58.337. (b) Proteolytic count, not more than 100 per gram; yeast and mold count, not more than 20 per gram; coliform count, not more than 10 per gram. (c) Optional except when...; enterococci, not more than 10 per gram. ...
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Code of Federal Regulations, 2012 CFR
2012-01-01
... accordance with §§ 58.336 and 58.337. (b) Proteolytic count, not more than 100 per gram; yeast and mold count, not more than 20 per gram; coliform count, not more than 10 per gram. (c) Optional except when...; enterococci, not more than 10 per gram. ...
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Code of Federal Regulations, 2010 CFR
2010-01-01
... accordance with §§ 58.336 and 58.337. (b) Proteolytic count, not more than 100 per gram; yeast and mold count, not more than 20 per gram; coliform count, not more than 10 per gram. (c) Optional except when...; enterococci, not more than 10 per gram. ...
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Code of Federal Regulations, 2014 CFR
2014-01-01
... accordance with §§ 58.336 and 58.337. (b) Proteolytic count, not more than 100 per gram; yeast and mold count, not more than 20 per gram; coliform count, not more than 10 per gram. (c) Optional except when...; enterococci, not more than 10 per gram. ...
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Code of Federal Regulations, 2013 CFR
2013-01-01
... accordance with §§ 58.336 and 58.337. (b) Proteolytic count, not more than 100 per gram; yeast and mold count, not more than 20 per gram; coliform count, not more than 10 per gram. (c) Optional except when...; enterococci, not more than 10 per gram. ...
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Microorganism Removal in Permeable Pavement Parking Lots in Edison Environmental Center, New Jersey
Three types of permeable pavements (pervious concrete, permeable interlocking concrete pavers, and porous asphalt) were monitored at the Edison Environmental Center in Edison, New Jersey for indicator organisms such as fecal coliform, enterococci, and E. coli. Results showed tha...
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Sewage Reflects the Distriubtion of Human Faecal Lachnospiraceae
Faecal pollution contains a rich and diverse community of bacteria derived from animals and humans,many of which might serve as alternatives to the traditional enterococci and Escherichia coli faecal indicators. We used massively parallel sequencing (MPS)of the 16S rRNA gene to ...
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TEMPORAL VARIABILITY OF ENTEROCOCCI SPECIES IN STREAMS IMPACTED BY CATTLE FECAL CONTAMINATION
Temporal variability in the gastrointestinal flora of animals impacting water resources with fecal material can be one of the factors producing low source identification rates when applying microbial source tracking (MST) methods. Our objective is to identify and compare the temp...
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Vannini, Lucia; Patrignani, Francesca; Iucci, Luciana; Ndagijimana, Maurice; Vallicelli, Melania; Lanciotti, Rosalba; Guerzoni, Maria Elisabetta
2008-12-10
The principal aim of this work was to compare Pecorino cheeses obtained from ewes' milk previously subjected to high pressure homogenization (HPH) at 100 MPa with those produced from raw and heat treated ewes' milk. The HPH milk treatment induced a significant increase of the cheese yield and caused a reduction of enterococci, lactococci and yeasts in the curds. Enterococci cell loads remained at lower levels in cheeses obtained from HPH milk over the ripening period. Analyses of free fatty acids, Sodium Dodecil Sulphate (SDS)-PAGE profiles, Gas Chromatography-Mass Spectrometry-Solid Phase Microextraction (GC-MS-SPME) measurements of volatile compounds and sensory traits evidenced that the pressure treatment can be regarded also as a useful tool to differentiate products obtained from the same raw material. In fact such a milk treatment induced a marked lipolysis, an early proteolysis, a relevant modification of the volatile molecule profiles and sensory properties of Pecorino cheese.
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Yoshioka, Reyn M; Kim, Catherine J S; Tracy, Allison M; Most, Rebecca; Harvell, C Drew
2016-03-15
Sewage pollution threatens the health of coastal populations and ecosystems, including coral reefs. We investigated spatial patterns of sewage pollution in Puako, Hawaii using enterococci concentrations and δ(15)N Ulva fasciata macroalgal bioassays to assess relationships with the coral disease Porites lobata growth anomalies (PGAs). PGA severity and enterococci concentrations were high, spatially variable, and positively related. Bioassay algal δ(15)N showed low sewage pollution at the reef edge while high values of resident algae indicated sewage pollution nearshore. Neither δ(15)N metric predicted PGA measures, though bioassay δ(15)N was negatively related to coral cover. Furthermore, PGA prevalence was much higher than previously recorded in Hawaii and the greater Indo-Pacific, highlighting Puako as an area of concern. Although further work is needed to resolve the relationship between sewage pollution and coral cover and disease, these results implicate sewage pollution as a contributor to diminished reef health. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Thoe, W; Lee, Olive H K; Leung, K F; Lee, T; Ashbolt, Nicholas J; Yang, Ron R; Chui, Samuel H K
2018-06-01
Hong Kong's beach water quality classification scheme, used effectively for >25 years in protecting public health, was first established in local epidemiology studies during the late 1980s where Escherichia coli (E. coli) was identified as the most suitable faecal indicator bacteria. To review and further substantiate the scheme's robustness, a performance check was carried out to classify water quality of 37 major local beaches in Hong Kong during four bathing seasons (March-October) from 2010 to 2013. Given the enterococci and E. coli data collected, beach classification by the local scheme was found to be in line with the prominent international benchmarks recommended by the World Health Organization and the European Union. Local bacteriological studies over the last 15 years further confirmed that E. coli is the more suitable faecal indicator bacteria than enterococci in the local context. Copyright © 2018 Elsevier Ltd. All rights reserved.
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Wave energy level and geographic setting correlate with Florida beach water quality.
Feng, Zhixuan; Reniers, Ad; Haus, Brian K; Solo-Gabriele, Helena M; Kelly, Elizabeth A
2016-03-15
Many recreational beaches suffer from elevated levels of microorganisms, resulting in beach advisories and closures due to lack of compliance with Environmental Protection Agency guidelines. We conducted the first statewide beach water quality assessment by analyzing decadal records of fecal indicator bacteria (enterococci and fecal coliform) levels at 262 Florida beaches. The objectives were to depict synoptic patterns of beach water quality exceedance along the entire Florida shoreline and to evaluate their relationships with wave condition and geographic location. Percent exceedances based on enterococci and fecal coliform were negatively correlated with both long-term mean wave energy and beach slope. Also, Gulf of Mexico beaches exceeded the thresholds significantly more than Atlantic Ocean ones, perhaps partially due to the lower wave energy. A possible linkage between wave energy level and water quality is beach sand, a pervasive nonpoint source that tends to harbor more bacteria in the low-wave-energy environment. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Global occurrence of Torque teno virus in water systems.
Charest, A J; Plummer, J D; Long, S C; Carducci, A; Verani, M; Sidhu, J P S
2015-09-01
Bacterial indicator organisms are used globally to assess the microbiological safety of waters. However, waterborne viral outbreaks have occurred in drinking water systems despite negative bacterial results. Using viral markers may therefore provide more accurate health risk assessment data. In this study, fecal, wastewater, stormwater, surface water (fresh and salt), groundwater, and drinking water samples were analyzed for the presence or concentration of traditional indicators, innovative indicators and viral markers. Samples were obtained in the United States, Italy, and Australia and results compared to those reported for studies conducted in Asia and South America as well. Indicators included total coliforms, Escherichia coli, enterococci, male-specific coliphages, somatic coliphages and microviradae. Viral markers included adenovirus, polyomavirus, and a potential new surrogate, Torque teno virus (TTV). TTV was more frequently found in wastewaters (38-100%) and waters influenced by waste discharges (25%) than in surface waters used as drinking water sources (5%). TTV was also specific to human rather than animal feces. While TTV numbers were strongly correlated to other viral markers in wastewaters, suggesting its utility as a fecal contamination marker, data limitations and TTV presence in treated drinking waters demonstrates that additional research is needed on this potential viral indicator.
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RAPID DETECTION METHOD FOR E.COLI, ENTEROCOCCI AND BACTEROIDES IN RECREATIONAL WATER
Current methodology for determining fecal contamination of drinking water sources and recreational waters rely on the time-consuming process of bacterial multiplication and require at least 24 hours from the time of sampling to the possible determination that the water is unsafe ...
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RAPID METHODS FOR MEASURING INDICATOR BACTERIA IN BATHING BEACH WATERS
The current methods for measuring the quality of recreational waters were developed in the 1970's and were recommended to the States by EPA in 1986. These methods detect and quantify Escherichia coli and enterococci, two bacteria that are consistently associated with fecal wast...
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PROTECTING HEALTH WITH SAME DAY WATER QUALITY MONITORING RESULTS FOR BATHING BEACHES
Current US Environmental Protection Agency guidelines recommend the use of cultural methods for E. coli and enterococci to monitor beach water quality. The guidelines recommend a single sample value or a geometric mean value from at least five samples. The single sample guideli...
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Tylosin-resistant Enterococci, erm genes, and tylosin in drained fields receiving swine manure
USDA-ARS?s Scientific Manuscript database
The use of tylosin at subtherapeutic levels by the swine industry provides selective pressure for the development of antibiotic resistance in gastrointestinal bacteria. The land application of swine manure to drained agricultural fields might introduce elevated levels of total and tylosin-resistant ...
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Buckwalter, Theodore F.; Zimmerman, Tammy M.; Fulton, John W.
2006-01-01
Concentrations of fecal-indicator bacteria were determined in 1,027 water-quality samples collected from July 2001 through August 2005 during dry- (72-hour dry antecedent period) and wet-weather (48-hour dry antecedent period and at least 0.3 inch of rain in a 24-hour period) conditions in the Allegheny, Monongahela, and Ohio Rivers (locally referred to as the Three Rivers) and selected tributaries in Allegheny County. Samples were collected at five sampling sites on the Three Rivers and at eight sites on four tributaries to the Three Rivers having combined sewer overflows. Water samples were analyzed for three fecal-indicator organisms fecal coliform, Escherichia coli (E. coli), and enterococci bacteria. Left-bank and right-bank surface-water samples were collected in addition to a cross-section composite sample at each site. Concentrations of fecal coliform, E. coli, and enterococci were detected in 98.6, 98.5, and 87.7 percent of all samples, respectively. The maximum fecal-indicator bacteria concentrations were collected from Sawmill Run, a tributary to the Ohio River; Sawmill Run at Duquesne Heights had concentrations of fecal coliform, E. coli, and enterococci of 410,000, 510,000, and 180,000 col/100 mL, respectively, following a large storm. The samples collected in the Three Rivers and selected tributaries frequently exceeded established recreational standards and criteria for bacteria. Concentrations of fecal coliform exceeded the Pennsylvania water-quality standard (200 col/100 mL) in approximately 63 percent of the samples. Sample concentrations of E. coli and enterococci exceeded the U.S. Environmental Protection Agency (USEPA) water-quality criteria (235 and 61 col/100 mL, respectively) in about 53 and 47 percent, respectively, of the samples. Fecal-indicator bacteria were most strongly correlated with streamflow, specific conductance, and turbidity. These correlations most frequently were observed in samples collected from tributary sites. Fecal-indicator bacteria concentrations and turbidity were correlated to the location of sample collection in the cross section. Most differences were between bank and composite samples; differences between right-bank and left-bank samples were rarely observed. The Allegheny River sites had more significant correlations than the Monongahela or Ohio River sites. Comparisons were made between fecal-indicator bacteria in composite samples collected during dry-weather, wet-weather day-one, wet-weather day-two (tributary sites only), and wet-weather day-three (Three Rivers sites only) events in the Three Rivers and selected tributary sites. The lowest median bacteria concentrations generally were observed in the dry-weather composite samples. All median bacteria concentrations in dry-weather composite samples in the five Three Rivers sites were below water-quality standards and criteria; bacteria concentrations in the upstream tributary sites rarely met all standards or criteria. Only Turtle Creek, Thompson Run, and Chartiers Creek had at least one median bacteria concentration below water-quality standards or criteria. Median bacteria concentrations in the composite samples generally were higher the day after a wet-weather event compared to dry-weather composite samples and other wet-weather composite samples collected. In the five Three Rivers sites, median bacteria concentrations 3 days after a wet-weather event in composite samples tended to fall below the water-quality standards and criteria; in the eight tributary sites, median bacteria concentrations in the dry-weather and wet-weather composite samples generally were above the water-quality standards or criteria. Composite samples collected at the upstream sites on the Three Rivers and selected tributaries generally had lower median bacteria concentrations than composite samples collected at the downstream sites during dry- and wet-weather events. Higher concentrations downstream may be because o
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USDA-ARS?s Scientific Manuscript database
Although enterococci are considered commensal bacteria, they are capable of causing disease in humans and animals. Enterococcus cecorum has been implicated as a possible cause of disease in poultry across the world. However, the characteristics that contribute to pathogenesis of E. cecorum in poul...
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Currently, the quality of drinking and recreational waters is estimated through the measurement of fecal bacteria such as Escherichia coli and Enterococci. However, since it takes time for the microorganisms to grow and be detected, their utility as indicators of human fecal co...
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Three types of permeable pavements were monitored at the Edison Environmental Center in Edison, New Jersey for indicator organisms such as fecal coliform, enterococci, and E. coli. Results showed that porous asphalt had much lower concentration in monitored infiltrate compared t...
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Ultrafiltration systems have been used to concentrate pathogens from various types of fresh water samples. However, less work has been done with marine waters for the concentration of pathogens or indicator bacteria. An ultrafiltration approach to concentrate indicator bacteria...
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Spatial and temporal variation of fecal indicator organisms in two creeks in Beltsville, Maryland
USDA-ARS?s Scientific Manuscript database
Evaluation of microbial water quality is commonly achieved by monitoring populations of indicator bacteria such as E. coli and enterococci. Monitoring data are utilized by water managers to predict potential fecal contaminations as well as a decision tool to improve microbial water quality. Both te...
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Several studies have demonstrated association between gastrointestinal illness (GI) in swimmers and sewage pollution as measured by the density of indicator organisms, such as e. coli and enterococci, in recreational waters. These studies generally classify illnesses into two ca...
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RAPID, PCR-BASED METHODS FOR MEASURING THE QUALITY OF BATHING BEACH WATERS
The current methods for measuring the quality of recreational waters were developed in the 1970's and were recommended to the States by EPA in 1986. These methods detect and quantify Escherichia coli and enterococci, two bacteria that are consistently associated with fecal wast...
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Sanitary quality of recreational waters is assessed by enumerating fecal indicator bacteria (FIB) (Escherichia coli and enterococci); organisms present in the gastrointestinal tract of humans and many other animals, hence providing no information about the pollution source. Micro...
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Virtual Beach (VB) is a decision support tool that constructs site-specific statistical models to predict fecal indicator bacteria (FIB) at locations of exposure. Although primarily designed for making decisions regarding beach closures or issuance of swimming advisories based on...
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USDA-ARS?s Scientific Manuscript database
We compared the occurrences of 3rd-generation cephalosporin-resistant (3GCr ), tetracycline-resistant (TETr) and trimethoprim-sulfamethoxazole-resistant (COTr ) Escherichia coli, 3GCr Salmonella enterica, nalidixic acid-resistant (NALr) S. enterica and erythromycin-resistant (ERYr) enterococci from ...
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Cold air plasma to decontaminate inanimate surfaces of the hospital environment.
Cahill, Orla J; Claro, Tânia; O'Connor, Niall; Cafolla, Anthony A; Stevens, Niall T; Daniels, Stephen; Humphreys, Hilary
2014-03-01
The hospital environment harbors bacteria that may cause health care-associated infections. Microorganisms, such as multiresistant bacteria, can spread around the patient's inanimate environment. Some recently introduced biodecontamination approaches in hospitals have significant limitations due to the toxic nature of the gases and the length of time required for aeration. This study evaluated the in vitro use of cold air plasma as an efficient alternative to traditional methods of biodecontamination of hospital surfaces. Cultures of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), extended-spectrum-β-lactamase (ESBL)-producing Escherichia coli, and Acinetobacter baumannii were applied to different materials similar to those found in the hospital environment. Artificially contaminated sections of marmoleum, mattress, polypropylene, powder-coated mild steel, and stainless steel were then exposed to a cold air pressure plasma single jet for 30 s, 60 s, and 90 s, operating at approximately 25 W and 12 liters/min flow rate. Direct plasma exposure successfully reduced the bacterial load by log 3 for MRSA, log 2.7 for VRE, log 2 for ESBL-producing E. coli, and log 1.7 for A. baumannii. The present report confirms the efficient antibacterial activity of a cold air plasma single-jet plume on nosocomial bacterially contaminated surfaces over a short period of time and highlights its potential for routine biodecontamination in the clinical environment.
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Paul, J H; Rose, J B; Jiang, S; Kellogg, C; Shinn, E A
1995-01-01
Sewage waste disposal facilities in the Florida Keys include septic tanks and individual package plants in place of municipal collection facilities in most locations. In Key Largo, both facilities discharge into the extremely porous Key Largo limestone. To determine whether there was potential contamination of the subsurface aquifer and nearby coastal surface waters by such waste disposal practices, we examined the presence of microbial indicators commonly found in sewage (fecal coliforms, Clostridium perfringens, and enterococci) and aquatic microbial parameters (viral direct counts, bacterial direct counts, chlorophyll a, and marine vibriophage) in injection well effluent, monitoring wells that followed a transect from onshore to offshore, and surface waters above these wells in two separate locations in Key Largo in August 1993 and March 1994. Effluent and waters from onshore shallow monitoring wells (1.8- to 3.7-m depth) contained two or all three of the fecal indicators in all three samples taken, whereas deeper wells (10.7- to 12.2-m depth) at these same sites contained few or none. The presence of fecal indicators was found in two of five nearshore wells (i.e., those that were < or = 1.8 miles [< or = 2.9 km] from shore), whereas offshore wells (> or = 2.1 to 5.7 miles [< or = 3.4 to 9.2 km] from shore) showed little sign of contamination. Indicators were also found in surface waters in a canal in Key Largo and in offshore surface waters in March but not in August. Collectively, these results suggest that fecal contamination of the shallow onshore aquifer, parts of the nearshore aquifer, and certain surface waters has occurred.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7793943
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NASA Astrophysics Data System (ADS)
Rio, Marlène; Salles, Christian; Rodier, Claire; Cantet, Franck; Marchand, Pierre; Mosser, Thomas; Cernesson, Flavie; Monfort, Patrick; Tournoud, Marie-George
2017-10-01
In coastal catchments, rainfall events primarily drive bacterial inputs to the sea by causing land runoff, surface leaching and sewer overflow. Under semi-arid climate, extensive dry periods are interspersed with extreme precipitation. This paper aims to assess the impact of intense summer rainstorms events on Fecal Indicator Bacteria loadings to Mediterranean seawaters. Firstly, explanatory relationships were derived between an Antecedent Precipitation Index and the loads of thermo-tolerant coliforms and intestinal enterococci measured at three catchment outlets in the Gulf of Aigues-Mortes (southern France). Secondly, fecal bacterial loadings were simulated during summer season from 2006-2016, with a confidence interval arising from measurements uncertainties. On average, more than two rainstorms per summer season elevate bacterial loads at least by one order of magnitude, potentially leading to the degradation of bathing and fishing water quality observed in regulatory monitoring data. The results highlight the crucial importance of considering hydrological conditions in coastal water quality management.
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Microbial spoilage of portuguese chouriço along shelf life period
de Jesus da Silva Matos, Teresa; Bruno-Soares, Arminda; Azevedo, António Amaral
2013-01-01
Microbial flora of portuguese chouriço (Alentejano (A) and Ribatejano (R)) with abnormal sensorial characteristics along shelf life was studied. Mesophilic anaerobic bacteria, enterococci, mesophilic sporeformers, coliforms, coagulase-positive staphylococci, sulphite reducing clostridia, Clostridium perfringens, moulds and yeasts were the most representative in both types of chouriço. PMID:24159290
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BEACH Act amendment to Clean Water Act requires EPA to establish more expeditious methods for the timely detection of pathogens and pathogen indicators in coastal waters New methods should demonstrate utility for and be compatible with all CWA 304(a) criteria needs including:...
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Microbial source tracking (MST) is based on the assumption that specific strains of bacteria are associated with specific host species. MST methods are attractive because their application on environmental samples could help define the nature of water quality problems in impaire...
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The quality of drinking and recreational water is currently ascertained using indicator bacteria, such as Escherichia coli and fecal enterococci. However, the tests to analyze for these bacteria require 24 to 48 hours to complete, and do not discriminate between human and animal...
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40 CFR 141.202 - Tier 1 Public Notice-Form, manner, and frequency of notice.
Code of Federal Regulations, 2012 CFR
2012-07-01
...) Detection of E. coli, enterococci, or coliphage in source water samples as specified in § 141.402(a) and... (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Public Notification of Drinking Water Violations § 141.202 Tier 1 Public Notice—Form, manner, and frequency of notice. (a) Which...
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2017-06-01
to assess prescription practices, the Standard Inpatient Data Record (SIDR) to determine healthcare-associated exposures, Defense Manpower Data...1 Results ...limitations were applied to this annual summary. As such, this report presents analytical results and discussion of CY 2016 data for VRE infections in the
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The detection of fecal pollution is performed via culturing methods in spite of the fact that culturable counts can severely underestimate the densities of fecal microorganisms. One approach that has been used to enumerate bacteria is the direct viable count method (DVC). The ob...
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40 CFR 141.402 - Ground water source microbial monitoring and analytical methods.
Code of Federal Regulations, 2012 CFR
2012-07-01
... the medium is set forth in the article “Evaluation of Enterolert for Enumeration of Enterococci in...). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www... American Public Health Association, 1015 Fifteenth Street, NW., Washington, DC 20005-2605. 3 Medium is...
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USDA-ARS?s Scientific Manuscript database
Swine manure applied to agricultural fields may lead to the transport of antibiotic resistant bacteria and antibiotic resistance genes to freshwater systems. Enterococci were studied because they are fecal indicator bacteria associated with manure. Resistance genes include genes from live cells, dea...
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USDA-ARS?s Scientific Manuscript database
Antimicrobials are used in production agriculture to treat disease and promote animal growth, but the presence of antibiotics in the environment raises concern about widespread antibiotic resistance. This study documents the occurrence and transport of tylosin, tetracycline, enterococci resistant to...
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The current U. S. Environmental Protection Agency-approved method for Enterococci (Method 1600) in recreational water is a membrane filter (MF) method that takes 24 hours to obtain results. If the recreational water is not in compliance with the standard, the risk of exposure to...
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Bottone, Edward; Allerhand, Jona; Pisano, Michael A.
1971-01-01
A bacteriocin-producing strain of Streptococcus faecalis var. zymogenes (E-1) was isolated from clinical material (conjunctiva). The active substance differed from bacteriocins described by other investigators primarily in its spectrum of antibacterial activity, especially by its marked inhibition of Diplococcus pneumoniae. The E-1 bacteriocin also inhibited nonhemolytic strains of enterococci as well as one-third of the Viridans group of streptococcal strains investigated. The degree of inhibition, however, as indicated by the size of the zones against the latter organisms, was significantly reduced. No activity was detected against any of the strains belonging to the following groups of bacteria: hemolytic enterococci, beta-hemolytic streptococci, nonhemolytic streptococci, staphylococci, and various gram-negative species. Similarly, three strains each of Bacillus cereus and Listeria monocytogenes and one strain of Erysipelothrix insidiosa were not inhibited. The bacteriocin was able to diffuse through bacterial membranes as well as cellulose dialyzer tubing. It was inactivated by heating to 80 C for 20 min but resisted inactivation by either trypsin or chloroform. Images PMID:4398532
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Removal of micro-organisms in a small-scale hydroponics wastewater treatment system.
Ottoson, J; Norström, A; Dalhammar, G
2005-01-01
To measure the microbial removal capacity of a small-scale hydroponics wastewater treatment plant. Paired samples were taken from untreated, partly-treated and treated wastewater and analysed for faecal microbial indicators, i.e. coliforms, Escherichia coli, enterococci, Clostridium perfringens spores and somatic coliphages, by culture based methods. Escherichia coli was never detected in effluent water after >5.8-log removal. Enterococci, coliforms, spores and coliphages were removed by 4.5, 4.1, 2.3 and 2.5 log respectively. Most of the removal (60-87%) took place in the latter part of the system because of settling, normal inactivation (retention time 12.7 d) and sand filtration. Time-dependent log-linear removal was shown for spores (k = -0.17 log d(-1), r(2) = 0.99). Hydroponics wastewater treatment removed micro-organisms satisfactorily. Investigations on the microbial removal capacity of hydroponics have only been performed for bacterial indicators. In this study it has been shown that virus and (oo)cyst process indicators were removed and that hydroponics can be an alternative to conventional wastewater treatment.
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Lowden, Jonathan; Miller Neilan, Rachael; Yahdi, Mohammed
2014-03-01
The rising prevalence of vancomycin-resistant enterococci (VRE) is a major health problem in intensive care units (ICU) because of its association with increased mortality and high health care costs. We present a mathematical framework for determining cost-effective strategies for prevention and treatment of VRE in the ICU. A system of five ordinary differential equations describes the movement of ICU patients in and out of five VRE-related states. Two control variables representing the prevention and treatment of VRE are incorporated into the system. The basic reproductive number is derived and calculated for different levels of the two controls. An optimal control problem is formulated to minimize VRE-related deaths and costs associated with prevention and treatment controls over a finite time period. Numerical solutions illustrate optimal single and dual allocations of the controls for various cost values. Results show that preventive care has the greatest impact in reducing the basic reproductive number, while treatment of VRE infections has the most impact on reducing VRE-related deaths. Copyright © 2014 Elsevier Inc. All rights reserved.
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Raising the Alarmone: Within-Host Evolution of Antibiotic-Tolerant Enterococcus faecium
2017-01-01
ABSTRACT Enterococci are ancient commensal bacteria that recently emerged as leading causes of antibiotic-resistant, hospital-acquired infection. Vancomycin-resistant enterococci (VRE) epitomize why drug-resistant enterococcal infections are a problem: VRE readily colonize the antibiotic-perturbed gastrointestinal (GI) tract where they amplify to large numbers, and from there, they infect other body sites, including the bloodstream, urinary tract, and surgical wounds. VRE are resistant to many antimicrobials and host defenses, which facilitates establishment at the site of infection and confounds therapeutic clearance. Having evolved to colonize the GI tract, VRE are comparatively ill adapted to the human bloodstream. A recent study by Honsa and colleagues (E. S. Honsa et al., mBio 8:e02124-16, 2017, https://doi.org/10.1128/mBio.02124-16) found that a strain of vancomycin-resistant Enterococcus faecium evolved antibiotic tolerance within the bloodstream of an immunocompromised host by activating the stringent response through mutation of relA. Precisely how VRE colonize and infect and the selective pressures that led to the outgrowth of relA mutants are the subjects of ongoing research. PMID:28223450
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Lepelletier, D; Batard, E; Berthelot, P; Zahar, J-R; Lucet, J-C; Fournier, S; Jarlier, V; Grandbastien, B
2015-07-01
The increasing bacterial resistance to antibiotics has become a major public health concern bringing the threat of therapeutic impasses. In this context, control of the spread of highly-resistant bacteria emerging antibiotics (BHRe), such as glycopeptide-resistant enterococci (VRE) and Enterobacteriaceae producing carbapenemases (CPE), is based on a dual strategy of reducing the prescription of antibiotics to limit the pressure selection and preventing the spread from carriers. Prevention strategy is based on three different levels such as standard precautions for all patients with a particular focus on the management of excreta, and additional precautions for BHRe carriers. What makes it difficult is that carriage is usually completely asymptomatic, enterobacteria and enterococci are normal commensal of gut microbiota. Explosive dissemination of Enterobacteriaceae producing extended spectrum beta-lactamases in hospital and community heralds the emergence of CPE whose import by patients with a history of hospitalization in abroad may be the main source of spread in France. Copyright © 2015 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.
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Mishra, Nigam M; Stolarzewicz, Izabela; Cannaerts, David; Schuermans, Joris; Lavigne, Rob; Looz, Yannick; Landuyt, Bart; Schoofs, Liliane; Schols, Dominique; Paeshuyse, Jan; Hickenbotham, Peter; Clokie, Martha; Luyten, Walter; Van der Eycken, Erik V; Briers, Yves
2018-01-01
Vancomycin is a glycopeptide antibiotic that inhibits transpeptidation during cell wall synthesis by binding to the D-Ala-D-Ala termini of lipid II. For long, it has been used as a last resort antibiotic. However, since the emergence of the first vancomycin-resistant enterococci in 1987, vancomycin resistance has become widespread, especially in hospitals. We have synthesized and evaluated 110 vancomycin analogs modified at the C-terminal carboxyl group of the heptapeptide moiety with R 2 NHR 1 NH 2 substituents. Through iterative optimizations of the substituents, we identified vancomycin analogs that fully restore (or even exceed) the original inhibitory activity against vancomycin-resistant enterococci (VRE), vancomycin-intermediate (VISA) and vancomycin-resistant Staphylococcus aureus (VRSA) strains. The best analogs have improved growth inhibitory activity and in vitro therapeutic indices against a broad set of VRE and methicillin-resistant S. aureus (MRSA) isolates. They also exceed the activity of vancomycin against Clostridium difficile ribotypes. Vanc-39 and Vanc-42 have a low probability to provoke antibiotic resistance, and overcome different vancomycin resistance mechanisms (VanA, VanB, and VanC1).
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Microbiological quality of Puget Sound Basin streams and identification of contaminant sources
Embrey, S.S.
2001-01-01
Fecal coliforms, Escherichia coli, enterococci, and somatic coliphages were detected in samples from 31 sites on streams draining urban and agricultural regions of the Puget Sound Basin Lowlands. Densities of bacteria in 48 and 71 percent of the samples exceeded U.S. Environmental Protection Agency's freshwater recreation criteria for Escherichia coli and enterococci, respectively, and 81 percent exceeded Washington State fecal coliform standards. Male-specific coliphages were detected in samples from 15 sites. Male-specific F+RNA coliphages isolated from samples taken at South Fork Thornton and Longfellow Creeks were serotyped as Group II, implicating humans as potential contaminant sources. These two sites are located in residential, urban areas. F+RNA coliphages in samples from 10 other sites, mostly in agricultural or rural areas, were serotyped as Group I, implicating non-human animals as likely sources. Chemicals common to wastewater, including fecal sterols, were detected in samples from several urban streams, and also implicate humans, at least in part, as possible sources of fecal bacteria and viruses to the streams.
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Mika, K B; Imamura, G; Chang, C; Conway, V; Fernandez, G; Griffith, J F; Kampalath, R A; Lee, C M; Lin, C-C; Moreno, R; Thompson, S; Whitman, R L; Jay, J A
2009-07-01
Factors affecting faecal indicator bacteria (FIB) and pathogen survival/persistence in sand remain largely unstudied. This work elucidates how biological and physical factors affect die-off in beach sand following sewage spills. Solar disinfection with mechanical mixing was pilot-tested as a disinfection procedure after a large sewage spill in Los Angeles. Effects of solar exposure, mechanical mixing, predation and/or competition, season, and moisture were tested at bench scale. First-order decay constants for Escherichia coli ranged between -0.23 and -1.02 per day, and for enterococci between -0.5 and -1.0 per day. Desiccation was a dominant factor for E. coli but not enterococci inactivation. Effects of season were investigated through a comparison of experimental results from winter, spring, and fall. Moisture was the dominant factor controlling E. coli inactivation kinetics. Initial microbial community and sand temperature were also important factors. Mechanical mixing, common in beach grooming, did not consistently reduce bacterial levels. Inactivation rates are mainly dependent on moisture and high sand temperature. Chlorination was an effective disinfection treatment in sand microcosms inoculated with raw influent.
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Aktürk, Hacer; Sütçü, Murat; Somer, Ayper; Karaman, Serap; Acar, Manolya; Ünüvar, Ayşegül; Anak, Sema; Karakaş, Zeynep; Özdemir, Aslı; Sarsar, Kutay; Aydın, Derya; Salman, Nuran
2016-09-05
To investigate the clinical impact of vancomycin-resistant enterococci (VRE) colonization in patients with hematologic malignancies and associated risk factors. Patients colonized and infected with VRE were identified from an institutional surveillance database between January 2010 and December 2013. A retrospective case-control study was performed to identify the risk factors associated with development of VRE infection in VRE-colonized patients. Fecal VRE colonization was documented in 72 of 229 children (31.4%). Seven VRE-colonized patients developed subsequent systemic VRE infection (9.7%). Types of VRE infections included bacteremia (n=5), urinary tract infection (n=1), and meningitis (n=1). Enterococcus faecium was isolated in all VRE infections. Multivariate analysis revealed severe neutropenia and previous bacteremia with another pathogen as independent risk factors for VRE infection development in colonized patients [odds ratio (OR): 35.4, confidence interval (CI): 1.7-72.3, p=0.02 and OR: 20.6, CI: 1.3-48.6, p=0.03, respectively]. No deaths attributable to VRE occurred. VRE colonization has important consequences in pediatric cancer patients.
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Cladophora in the Great Lakes: impacts on beach water quality and human health.
Verhougstraete, M P; Byappanahalli, M N; Rose, J B; Whitman, R L
2010-01-01
Cladophora in the Great Lakes grows rapidly during the warm summer months, detaches, and becomes free-floating mats as a result of environmental conditions, eventually becoming stranded on recreational beaches. Cladophora provides protection and nutrients, which allow enteric bacteria such as Escherichia coli, enterococci, Shigella, Campylobacter, and Salmonella to persist and potentially regrow in the presence of the algae. As a result of wind and wave action, these microorganisms can detach and be released to surrounding waters and can influence water quality. Enteric bacterial pathogens have been detected in Cladophora mats; E. coli and enterococci may populate to become part of the naturalized microbiota in Cladophora; the high densities of these bacteria may affect water quality, resulting in unnecessary beach closures. The continued use of traditional fecal indicators at beaches with Cladophora presence is inadequate at accurately predicting the presence of fecal contamination. This paper offers a substantial review of available literature to improve the knowledge of Cladophora impacts on water quality, recreational water monitoring, fecal indicator bacteria and microorganisms, and public health and policy.
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Pidgeon, Sean E; Pires, Marcos M
2017-07-21
Drug-resistant bacterial infections threaten to overburden our healthcare system and disrupt modern medicine. A large class of potent antibiotics, including vancomycin, operate by interfering with bacterial cell wall biosynthesis. Vancomycin-resistant enterococci (VRE) evade the blockage of cell wall biosynthesis by altering cell wall precursors, rendering them drug insensitive. Herein, we reveal the phenotypic plasticity and cell wall remodeling of VRE in response to vancomycin in live bacterial cells via a metabolic probe. A synthetic cell wall analog was designed and constructed to monitor cell wall structural alterations. Our results demonstrate that the biosynthetic pathway for vancomycin-resistant precursors can be hijacked by synthetic analogs to track the kinetics of phenotype induction. In addition, we leveraged this probe to interrogate the response of VRE cells to vancomycin analogs and a series of cell wall-targeted antibiotics. Finally, we describe a proof-of-principle strategy to visually inspect drug resistance induction. Based on our findings, we anticipate that our metabolic probe will play an important role in further elucidating the interplay among the enzymes involved in the VRE biosynthetic rewiring.
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Cladophora in the Great Lakes: Impacts on beach water quality and human health
Verhougstraete, M.P.; Byappanahalli, Muruleedhara N.; Rose, J.B.; Whitman, Richard L.
2010-01-01
Cladophora in the Great Lakes grows rapidly during the warm summer months, detaches, and becomes free-floating mats as a result of environmental conditions, eventually becoming stranded on recreational beaches. Cladophora provides protection and nutrients, which allow enteric bacteria such as Escherichia coli, enterococci, Shigella, Campylobacter, and Salmonella to persist and potentially regrow in the presence of the algae. As a result of wind and wave action, these microorganisms can detach and be released to surrounding waters and can influence water quality. Enteric bacterial pathogens have been detected in Cladophora mats; E. coli and enterococci may populate to become part of the naturalized microbiota in Cladophora; the high densities of these bacteria may affect water quality, resulting in unnecessary beach closures. The continued use of traditional fecal indicators at beaches with Cladophora presence is inadequate at accurately predicting the presence of fecal contamination. This paper offers a substantial review of available literature to improve the knowledge of Cladophora impacts on water quality, recreational water monitoring, fecal indicator bacteria and microorganisms, and public health and policy.
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Bactericidal efficacy of molybdenum oxide nanoparticles against antimicrobial-resistant pathogens.
Lopes, E; Piçarra, S; Almeida, P L; de Lencastre, H; Aires-de-Sousa, M
2018-06-25
Multidrug-resistant bacteria pose a major threat to effective antibiotics and alternatives to fight multidrug-resistant pathogens are needed. We synthetized molybdenum oxide (MoO3) nanoparticles (NP) and determined their antibacterial activity against 39 isolates: (i) eight Staphylococcus aureus, including representatives of methicillin-resistant S. aureus epidemic clones; (ii) six enterococci, including vancomycin-resistant isolates; and (iii) 25 Gram-negative isolates (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, Enterobacter cloacae), including extended spectrum beta-lactamases and carbapenemases producers. All isolates showed a MoO3 NP MIC of 700-800 mg l -1 . MoO3 NP produced a clear inhibition zone for S. aureus and all Gram-negative isolates at concentrations ≥25 mg ml -1 and ≥50 mg ml -1 for enterococci. When the NP solutions were adjusted to pH ~7, the biocidal activity was completely abolished. MoO3 NP create an acidic pH and show a universal antimicrobial activity against susceptible and resistant isolates belonging to the most relevant bacterial species responsible for hospital-acquired infections.
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Garcia-Garrote, Fernando; Cercenado, Emilia; Bouza, Emilio
2000-01-01
We evaluated the new automated VITEK 2 system (bioMérieux) for the identification and antimicrobial susceptibility testing of enterococci. The results obtained with the VITEK 2 system were compared to those obtained by reference methods: standard identification by the scheme of Facklam and Sahm [R. R. Facklam and D. F. Sahm, p. 308–314, in P. R. Murray et al., ed., Manual of Clinical Microbiology, 6th ed., 1995] and with the API 20 STREP system and, for antimicrobial susceptibility testing, broth microdilution and agar dilution methods by the procedures of the National Committee for Clinical Laboratory Standards. The presence of vanA and vanB genes was determined by PCR. A total of 150 clinical isolates were studied, corresponding to 60 Enterococcus faecalis, 55 Enterococcus faecium, 26 Enterococcus gallinarum, 5 Enterococcus avium, 2 Enterococcus durans, and 2 Enterococcus raffinosus isolates. Among those isolates, 131 (87%) were correctly identified to the species level with the VITEK 2 system. Approximately half of the misidentifications were for E. faecium with low-level resistance to vancomycin, identified as E. gallinarum or E. casseliflavus; however, a motility test solved the discrepancies and increased the agreement to 94%. Among the strains studied, 66% were vancomycin resistant (57 VanA, 16 VanB, and 26 VanC strains), 23% were ampicillin resistant (MICs, ≥16 μg/ml), 31% were high-level gentamicin resistant, and 45% were high-level streptomycin resistant. Percentages of agreement for susceptibility and resistance to ampicillin, vancomycin, and teicoplanin and for high-level gentamicin resistance and high-level streptomycin resistance were 93, 95, 97, 97, and 96%, respectively. The accuracy of identification and antimicrobial susceptibility testing of enterococci with the VITEK 2 system, together with the significant reduction in handling time, will have a positive impact on the work flow of the clinical microbiology laboratory. PMID:10834961
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Removal of faecal bacteria from septage by treating it in a full-scale duckweed-covered pond system.
Papadopoulos, Frantzis H; Tsihrintzis, Vassilios A; Zdragas, Antonios G
2011-12-01
Performance of a full-scale duckweed-covered treatment system in removing faecal bacteria is presented. The system consisted of three ponds in series and received septage from holding tanks. Inflow averaged between 36 m(3) d(-1) in the cold season and 60 m(3) d(-1) in the warm season, resulting in a total hydraulic retention time of 88 and 58 days, respectively. Duckweed (Lemna minor) colonized the ponds in the summer and continued to grow in the cold season. Due to the difficult harvesting process of the duckweed biomass, the investigation of the treatment efficiency was carried out without plant harvesting. The system was monitored for temperature, pH, oxygen, chlorophyll-a, Escherichia coli and Enterococci. Duckweed growth resulted in chlorophyll-a concentration reduction from 924 to 13 μg L(-1), causing neutral and anoxic conditions in the pond water. A temperature effect was noticed on the E. coli decay coefficient with a decreasing trend along the treatment system. Enterococci always decayed less than E. coli. Differences on decay coefficients and removal efficiencies were not observed between the three ponds for both bacterial types. Effluent quality in terms of E. coli was 489 and 1377 cfu/100 mL, in the warm and the cold seasons, respectively, with average removals of 99.65 ± 1.46% and 99.33 ± 3.03%. Total Enterococci removal was 88.91 ± 23.1% in the warm season and 94.43 ± 24.45% in the cold season, resulting in mean effluent values of 1058 and 1404 cfu/100 mL, respectively. The seasonal differences in total removal efficiencies were insignificant for both bacterial types. Copyright © 2011 Elsevier Ltd. All rights reserved.
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Ramaswamy, Divya Pradeep; Amodio-Groton, Maria; Scholand, Stephen J
2013-07-16
Vancomycin-resistant enterococci are a leading cause of hospital-acquired urinary tract infection and a growing concern for the clinician. The aim of this study was to evaluate the effectiveness of daptomycin in the treatment of patients with vancomycin-resistant enterococcal urinary tract infection treated in our 200-bed community-based institution. Patients with confirmed symptomatic vancomycin-resistant enterococcal urinary tract infection identified by infectious disease consultation between January 1, 2007, and December 8, 2009, vancomycin-resistant enterococci-positive urine culture, and urinary symptoms and/or pyuria on urinalysis, and treated with daptomycin, were included in this case series. Daptomycin was generally administered at a planned dosage regimen of ≥ 5 mg/kg every 24 hours in patients with normal to moderately impaired kidney function or every 48 hours in patients with severe kidney disease. Microbiologic cure was defined as eradication of vancomycin-resistant enterococci in urine cultures taken after the completion of daptomycin treatment. Clinical cure was defined by symptom resolution, as assessed by the infectious disease clinician caring for the patient. Included in this case series are 10 patients who received daptomycin for confirmed vancomycin-resistant enterococcal urinary tract infection. Patients had a history of extensive hospital stays. Chart review revealed that all levels of kidney function (3, 2, 3, and 2 patients with kidney disease classified as normal, mild, moderate, and severe/kidney failure, respectively) were represented in the sample and that patients with (n = 5) or without (n = 5) previous urinary tract infection and with (n = 3) or without (n = 7) Foley catheters were included. Treatment with daptomycin achieved clinical cure and vancomycin-resistant enterococcal eradication in all cases in this series. Treatment with daptomycin was well tolerated and effective in all patients in this series, regardless of renal function, history of urinary tract infection, or Foley catheter use. This study adds to emerging clinical evidence that daptomycin is a valuable treatment for vancomycin-resistant enterococcal urinary tract infection.
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Houben, J H
2003-11-15
Experiments with 148 isolates of vancomycin-resistant enterococci (VRE) were performed to assess their potential to persist and grow in fermented sausages and pasteurised meat products. All strains were meat isolates and Van-type A, except a single VanC1 strain. In total, 143 strains of Enterococcus faecium were involved. Eight selected strains were examined for their potential to grow at high salt and nitrite levels and at reduced pH. The same isolates were used in experiments with fermented sausages. All available strains were subjected to heating tests in meat suspensions with added curing ingredients. All but one of the eight tested isolates grew at pH 4.0 in tryptone soya broth (TSB). With the combination of 8% w/w NaCl, 400 ppm NaNO2 and 0.5% w/w glucose in the meat suspension, all isolates grew at 37 degrees C, whereas none grew at 7 degrees C even after 56 days. With the addition of 10% w/w NaCl, 200 ppm NaNO2 and 0.5% w/w glucose, still one E. faecium isolate grew at 37 degrees C, although very slowly. Overall, the strains tolerated high salt and nitrite concentrations and reduced pH very well, even beyond levels applied in the regular production of fermented and/or pasteurised meat products. The tested strains could be isolated after the fermentation and further ripening of "boerenmetworst" and "snijworst". Overall, their colony counts decreased on average about 1 log-unit over a period of 60 days after batter manufacture. All 148 isolates demonstrated a relatively weak thermal resistance compared to results for selected vancomycin-sensitive enterococci strains reported in the literature and to results collected under identical experimental conditions in this laboratory. None of the strains (log inoculation level about 5-6 ml(-1) for each isolate) could be cultured after heating at 70 degrees C for 10 min.
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Microbiological characteristics of "androlla", a Spanish traditional pork sausage.
García Fontán, María C; Lorenzo, José M; Parada, Ana; Franco, Inmaculada; Carballo, Javier
2007-02-01
Counts of total aerobic mesophilic microflora, lactic acid bacteria, salt-tolerant microflora, Enterobacteriaceae, enterococci, moulds and yeasts, and staphylococci, and some physico-chemical parameters (total solids, NaCl and nitrate contents and pH and aw values) were determined in 20 units of "androlla", a traditional dry-fermented sausage made in the NW of Spain. In general, high counts of all the investigated microbial groups were observed, with average values of 8.99 +/- 0.46 log cfu/g for the total aerobic mesophilic microflora, 9.11 +/- 0.16 log cfu/g for the lactic acid bacteria, 6.87 +/- 0.68 log cfu/g for the salt-tolerant microflora, 2.80+/-1.85 log cfu/g for the Enterobacteriaceae, 3.25 +/- 1.86 log cfu/g for the enterococci, 4.30 +/- 1.73 log cfu/g for the moulds and yeasts, and 3.62 +/- 0.60 log cfu/g for the staphylococci. From MRS agar, SPC agar + 7.5% NaCl, VRBG agar, and KAA agar, 10 colonies were randomly taken from each androlla unit and from each culture medium. A total of 200 strains per culture medium were then identified using the classical methods. Among the isolates from MRS agar, Lactobacillus sakei predominated, followed by Lactobacillus curvatus, Lactobacillus alimentarius and Lactobacillus plantarum. Of the 200 isolates obtained from SPC agar + 7.5% NaCl, only 56 strains belonged to the Staphylococcaceae or Micrococcaceae families. Among the Staphylococcaceae, Staphylococcus xylosus was the main species, followed by Staph. epidermidis; Staph. equorum, Staph. capitis and Staph. saprophyticus were isolated in very low proportions. Among the Micrococcaceae, Micrococcus luteus predominated, followed by Micrococcus lylae, Kocuria varians and Kocuria kristinae. Of the 150 isolates obtained from VRBG agar, Hafnia alvei was the main species, followed by Serratia liquefaciens and Enterobacter amnigenus; six isolates were identified as Salmonella. Among the 190 isolates obtained from KAA agar, 122 were considered enterococci; 20 isolates were identified as Enterococcus faecium, one as Enterococcus faecalis and 101 as Enterococcus inter faecalis-faecium.
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The Evolving Nature of Infective Endocarditis in Spain: A Population-Based Study (2003 to 2014).
Olmos, Carmen; Vilacosta, Isidre; Fernández-Pérez, Cristina; Bernal, José L; Ferrera, Carlos; García-Arribas, Daniel; Pérez-García, Carlos N; San Román, J Alberto; Maroto, Luis; Macaya, Carlos; Elola, Francisco J
2017-12-05
Little information exists regarding population-based epidemiological changes in infective endocarditis (IE) in Europe. This study sought to analyze temporal trends in IE in Spain from 2003 to 2014. This retrospective, population-based, temporal trend study analyzed the incidence, epidemiological and clinical characteristics, and outcome of all patients discharged from hospitals included in the Spanish National Health System with a diagnosis of IE, from January 2003 to December 2014. Overall, 16,867 episodes of IE were identified during the study period, 66.3% in men. The rate of IE significantly increased, from 2.72 in 2003 to 3.49 per 100,000 person-years in 2014, and this rise was higher among older adults. The most frequent microorganisms were staphylococci (28.7%), followed by streptococci (20.4%) and enterococci (13.1%). Twenty-three percent of patients underwent cardiac surgery. The in-hospital mortality rate was 20.4%. Throughout the study period, the proportion of patients with previously known heart valve disease and diabetes mellitus significantly increased, whereas the prevalence of intravenous drug use decreased. Regarding microorganisms, Staphylococcus aureus and streptococci slightly declined, whereas coagulase-negative staphylococci and enterococci consistently increased over the years. In-hospital complications and cardiac surgery rates significantly increased across the years. The risk-adjusted in-hospital mortality rate diminished (0.2% per year) during the study period. The incidence of IE episodes significantly increased over the decade of the study period, particularly among older adults. Relevant changes in clinical and microbiological profile included older patients with more comorbidity and a rise in enterococci and coagulase-negative staphylococcal infections. Adjusted mortality rates slightly declined over the study period. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.
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Di Grigoli, Antonino; Francesca, Nicola; Gaglio, Raimondo; Guarrasi, Valeria; Moschetti, Marta; Scatassa, Maria Luisa; Settanni, Luca; Bonanno, Adriana
2015-04-01
The influence of the wooden equipment used for the traditional cheese manufacturing from raw milk was evaluated on the variations of chemico-physical characteristics and microbial populations during the ripening of Caciocavallo Palermitano cheese. Milk from two farms (A, extensive; B, intensive) was processed in traditional and standard conditions. Chemical and physical traits of cheeses were affected by the farming system and the cheese making technology, and changed during ripening. Content in NaCl and N soluble was lower, and paste consistency higher in cheese from the extensive farm and traditional technology, whereas ripening increased the N soluble and the paste yellow and consistency. The ripening time decreased the number of all lactic acid bacteria (LAB) groups, except enterococci detected at approximately constant levels (10(4) and 10(5) cfu g(-1) for standard and traditional cheeses, respectively), till 120 d of ripening. In all productions, at each ripening time, the levels detected for enterococci were lower than those for the other LAB groups. The canonical discriminant analysis of chemical, physical and microbiological data was able to separate cheeses from different productions and ripening time. The dominant LAB were isolated, phenotypically characterised and grouped, genetically differentiated at strain level and identified. Ten species of LAB were found and the strains detected at the highest levels were Pediococcus acidilactici and Lactobacillus casei. Ten strains, mainly belonging to Lactobacillus rhamnosus and Lactobacillus fermentum showed an antibacterial activity. The comparison of the polymorphic profiles of the LAB strains isolated from the wooden vat with those of the strains collected during maturation, showed the persistence of three enterococci in traditional cheeses, with Enterococcus faecalis found at dominant levels over the Enterococcus population till 120 d; the absence of these strains in the standard productions evidenced the contribution of vat LAB during Caciocavallo Palermitano cheese ripening. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Voided Midstream Urine Culture and Acute Cystitis in Premenopausal Women
Hooton, Thomas M; Roberts, Pacita L.; Cox, Marsha E.; Stapleton, Ann E.
2014-01-01
BACKGROUND The cause of acute uncomplicated cystitis is determined on the basis of cultures of voided midstream urine, but few data guide the interpretation of such results, especially when gram-positive bacteria grow. METHODS Women from 18 to 49 years of age with symptoms of cystitis provided specimens of midstream urine, after which we collected urine by means of a urethral catheter for culture (catheter urine). We compared microbial species and colony counts in the paired specimens. The primary outcome was a comparison of positive predictive values and negative predictive values of organisms grown in midstream urine, with the presence or absence of the organism in catheter urine used as the reference. RESULTS The analysis of 236 episodes of cystitis in 226 women yielded 202 paired specimens of midstream urine and catheter urine that could be evaluated. Cultures were positive for uropathogens in 142 catheter specimens (70%), 4 of which had more than one uropathogen, and in 157 midstream specimens (78%). The presence of Escherichia coli in midstream urine was highly predictive of bladder bacteriuria even at very low counts, with a positive predictive value of 102 colony-forming units (CFU) per milliliter of 93% (Spearman’s r = 0.944). In contrast, in midstream urine, enterococci (in 10% of cultures) and group B streptococci (in 12% of cultures) were not predictive of bladder bacteriuria at any colony count (Spearman’s r = 0.322 for enterococci and 0.272 for group B streptococci). Among 41 episodes in which enterococcus, group B streptococci, or both were found in midstream urine, E. coli grew from catheter urine cultures in 61%. CONCLUSIONS Cultures of voided midstream urine in healthy premenopausal women with acute uncomplicated cystitis accurately showed evidence of bladder E. coli but not of enterococci or group B streptococci, which are often isolated with E. coli but appear to rarely cause cystitis by themselves. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases.) PMID:24224622
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Noble, M.A.; Xu, J. P.; Robertson, G.L.; Rosenfeld, L.K.
2006-01-01
Fecal indicator bacteria (FIB) were measured approximately 5 days a week in ankle-depth water at 19 surfzone stations along Huntington Beach and Newport Beach, California, from 1998 to the end of 2003. These sampling periods span the time before and after treated sewage effluent, discharged into the coastal ocean from the local outfall, was disinfected. Bacterial samples were also taken in the vicinity of the outfall during the pre- and post-disinfection periods. Our analysis of the results from both data sets suggest that land-based sources, rather than the local outfall, were the source of the FIB responsible for the frequent closures and postings of local beaches in the summers of 2001 and 2002. Because the annual cycle is the dominant frequency in the fecal and total coliform data sets at most sampling stations, we infer that sources associated with local runoff were responsible for the majority of coliform contamination along wide stretches of the beach. The dominant fortnightly cycle in enterococci at many surfzone sampling stations suggests that the source for these relatively frequent bacteria contamination events in summer is related to the wetting and draining of the land due to the large tidal excursions found during spring tides. Along the most frequently closed section of the beach at stations 3N-15N, the fortnightly cycle is dominant in all FIBs. The strikingly different spatial and spectral patterns found in coliform and in enterococci suggest the presence of different sources, at least for large sections of beach. The presence of a relatively large enterococci fortnightly cycle along the beaches near Newport Harbor indicates that contamination sources similar to those found off Huntington Beach are present, though not at high enough levels to close the Newport beaches. ?? 2006 Elsevier Ltd. All rights reserved.
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Manios, T; Papagrigoriou, I; Daskalakis, G; Sabathianakis, I; Terzakis, S; Maniadakis, K; Markakis, G
2006-08-01
Tomato and cucumber seedlings were distributed into 10 groups (five for each plant) of 15 plants each. The plants were irrigated for 10 weeks with primary treated wastewater (group A), secondary treated wastewater (group B), chlorinated secondary treated wastewater (group C), a fertilizer dilution (group F), and tap water (group M). All precautions were taken to secure that there was no direct contact between the wastewater and the edible portions of the crops. During this period and on a weekly basis, the height and number of leaves was monitored, while, at the end, the dry weight of leaves, stems, and roots for each plant of each group was measured. Based on these growth parameters, both types of plant in groups A and F recorded the most significant development compared to the other three groups. The plants irrigated with tap water recorded the smallest development, in every case. Plants in groups B and C were similar, with a slight (but not significant) superiority for the plants irrigated with secondary treated wastewater, probably as a result of some phytotoxic effects of residual chloride in the chlorinated wastewater. The presence of nutrients and specifically nitrogen in the various solutions explains the differences satisfactorily. The vegetables grown on the plants of each group were harvested, and their surface tissue analyzed for total coliforms (TC) and enterococci (EC). Tomatoes grown on the plants of groups A and B recorded the highest values for TC, with 505 and 490 cfu/g, respectively, whereas, for cucumbers, those values were 342 and 450 cfu/g, respectively. Enterococci were detected on the surface of harvested vegetables from groups A and B, but the small number of cases and their random character cannot support any strong relations between the used wastewater and their presence. The TC values in group C were very low, far lower than those if group F. No EC were found in either group C or group F. These primary results suggested that irrigation with appropriate disinfected wastewater, even of such high-risk cultivations of vegetables eaten raw, should not be discarded completely as unsafe, but be reconsidered and studied further. However, the use of undisinfected wastewater in such greenhouse cultivations, where all safety precautions have been taken to prevent any contact of the fruits with the soil or the wastewater, does not prove to be 100% safe.
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Weber, David J; Rutala, William A; Anderson, Deverick J; Chen, Luke F; Sickbert-Bennett, Emily E; Boyce, John M
2016-05-02
Over the last decade, substantial scientific evidence has accumulated that indicates contamination of environmental surfaces in hospital rooms plays an important role in the transmission of key health care-associated pathogens (eg, methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Clostridium difficile, Acinetobacter spp). For example, a patient admitted to a room previously occupied by a patient colonized or infected with one of these pathogens has a higher risk for acquiring one of these pathogens than a patient admitted to a room whose previous occupant was not colonized or infected. This risk is not surprising because multiple studies have demonstrated that surfaces in hospital rooms are poorly cleaned during terminal cleaning. To reduce surface contamination after terminal cleaning, no touch methods of room disinfection have been developed. This article will review the no touch methods, ultraviolet light devices, and hydrogen peroxide systems, with a focus on clinical trials which have used patient colonization or infection as an outcome. Multiple studies have demonstrated that ultraviolet light devices and hydrogen peroxide systems have been shown to inactivate microbes experimentally plated on carrier materials and placed in hospital rooms and to decontaminate surfaces in hospital rooms naturally contaminated with multidrug-resistant pathogens. A growing number of clinical studies have demonstrated that ultraviolet devices and hydrogen peroxide systems when used for terminal disinfection can reduce colonization or health care-associated infections in patients admitted to these hospital rooms. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
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Hoque, Jiaul; Akkapeddi, Padma; Yadav, Vikas; Manjunath, Goutham B; Uppu, Divakara S S M; Konai, Mohini M; Yarlagadda, Venkateswarlu; Sanyal, Kaustuv; Haldar, Jayanta
2015-01-28
Microbial attachment and subsequent colonization onto surfaces lead to the spread of deadly community-acquired and hospital-acquired (nosocomial) infections. Noncovalent immobilization of water insoluble and organo-soluble cationic polymers onto a surface is a facile approach to prevent microbial contamination. In the present study, we described the synthesis of water insoluble and organo-soluble polymeric materials and demonstrated their structure-activity relationship against various human pathogenic bacteria including drug-resistant strains such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and beta lactam-resistant Klebsiella pneumoniae as well as pathogenic fungi such as Candida spp. and Cryptococcus spp. The polymer coated surfaces completely inactivated both bacteria and fungi upon contact (5 log reduction with respect to control). Linear polymers were more active and found to have a higher killing rate than the branched polymers. The polymer coated surfaces also exhibited significant activity in various complex mammalian fluids such as serum, plasma, and blood and showed negligible hemolysis at an amount much higher than minimum inhibitory amounts (MIAs). These polymers were found to have excellent compatibility with other medically relevant polymers (polylactic acid, PLA) and commercial paint. The cationic hydrophobic polymer coatings disrupted the lipid membrane of both bacteria and fungi and thus showed a membrane-active mode of action. Further, bacteria did not develop resistance against these membrane-active polymers in sharp contrast to conventional antibiotics and lipopeptides, thus the polymers hold great promise to be used as coating materials for developing permanent antimicrobial paint.
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Uppu, Divakara S S M; Samaddar, Sandip; Ghosh, Chandradhish; Paramanandham, Krishnamoorthy; Shome, Bibek R; Haldar, Jayanta
2016-01-01
Bacterial biofilms represent the root-cause of chronic or persistent infections in humans. Gram-negative bacterial infections due to nosocomial and opportunistic pathogens such as Acinetobacter baumannii are more difficult to treat because of their inherent and rapidly acquiring resistance to antibiotics. Due to biofilm formation, A. baumannii has been noted for its apparent ability to survive on artificial surfaces for an extended period of time, therefore allowing it to persist in the hospital environment. Here we report, maleic anhydride based novel cationic polymers appended with amide side chains that disrupt surface established multi-drug resistant A. baumannii biofilms. More importantly, these polymers significantly (p < 0.0001) decrease the bacterial burden in mice with chronic A. baumannii burn wound infection. The polymers also show potent antibacterial efficacy against methicillin resistant Staphylococcus aureus (MRSA), vancomycin resistant Enterococci (VRE) and multi-drug resistant clinical isolates of A. baumannii with minimal toxicity to mammalian cells. We observe that optimal hydrophobicity dependent on the side chain chemical structure of these polymers dictate the selective toxicity to bacteria. Polymers interact with the bacterial cell membranes by causing membrane depolarization, permeabilization and energy depletion. Bacteria develop rapid resistance to erythromycin and colistin whereas no detectable development of resistance occurs against these polymers even after several passages. These results suggest the potential use of these polymeric biomaterials in disinfecting biomedical device surfaces after the infection has become established and also for the topical treatment of chronic bacterial infections. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Rule, Ana M; Evans, Sean L; Silbergeld, Ellen K
2008-01-01
Use of antimicrobial feed additives in food animal production is associated with selection for drug resistance in bacterial pathogens, which can then be released into the environment through occupational exposures, high volume ventilation of animal houses, and land application of animal wastes. We tested the hypothesis that current methods of transporting food animals from farms to slaughterhouses may result in pathogen releases and potential exposures of persons in vehicles traveling on the same road. Air and surface samples were taken from cars driving behind poultry trucks for 17 miles. Air conditioners and fans were turned off and windows fully opened. Background and blank samples were used for quality control. Samples were analyzed for susceptible and drug-resistant strains. Results indicate an increase in the number of total aerobic bacteria including both susceptible and drug-resistant enterococci isolated from air and surface samples, and suggest that food animal transport in open crates introduces a novel route of exposure to harmful microorganisms and may disseminate these pathogens into the general environment. These findings support the need for further exposure characterization, and attention to improving methods of food animal transport, especially in highly trafficked regions of high density farming such as the Delmarva Peninsula.
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Aström, Johan; Pettersson, Thomas J R; Reischer, Georg H; Hermansson, Malte
2013-09-01
The protection of drinking water from pathogens such as Cryptosporidium and Giardia requires an understanding of the short-term microbial release from faecal contamination sources in the catchment. Flow-weighted samples were collected during two rainfall events in a stream draining an area with on-site sewers and during two rainfall events in surface runoff from a bovine cattle pasture. Samples were analysed for human (BacH) and ruminant (BacR) Bacteroidales genetic markers through quantitative polymerase chain reaction (qPCR) and for sorbitol-fermenting bifidobacteria through culturing as a complement to traditional faecal indicator bacteria, somatic coliphages and the parasitic protozoa Cryptosporidium spp. and Giardia spp. analysed by standard methods. Significant positive correlations were observed between BacH, Escherichia coli, intestinal enterococci, sulphite-reducing Clostridia, turbidity, conductivity and UV254 in the stream contaminated by on-site sewers. For the cattle pasture, no correlation was found between any of the genetic markers and the other parameters. Although parasitic protozoa were not detected, the analysis for genetic markers provided baseline data on the short-term faecal contamination due to these potential sources of parasites. Background levels of BacH and BacR makers in soil emphasise the need to including soil reference samples in qPCR-based analyses for Bacteroidales genetic markers.
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Origin and spatial-temporal distribution of faecal bacteria in a bay of Lake Geneva, Switzerland.
Poté, John; Goldscheider, Nico; Haller, Laurence; Zopfi, Jakob; Khajehnouri, Fereidoun; Wildi, Walter
2009-07-01
The origin and distribution of microbial contamination in Lake Geneva's most polluted bay were assessed using faecal indicator bacteria (FIB). The lake is used as drinking water, for recreation and fishing. During 1 year, water samples were taken at 23 points in the bay and three contamination sources: a wastewater treatment plant (WWTP), a river and a storm water outlet. Analyses included Escherichia coli, enterococci (ENT), total coliforms (TC), and heterotrophic plate counts (HPC). E. coli input flux rates from the WWTP can reach 2.5 x 10(10) CFU/s; those from the river are one to three orders of magnitude lower. Different pathogenic Salmonella serotypes were identified in water from these sources. FIB levels in the bay are highly variable. Results demonstrate that (1) the WWTP outlet at 30 m depth impacts near-surface water quality during holomixis in winter; (2) when the lake is stratified, the effluent water is generally trapped below the thermocline; (3) during major floods, upwelling across the thermocline may occur; (4) the river permanently contributes to contamination, mainly near the river mouth and during floods, when the storm water outlet contributes additionally; (5) the lowest FIB levels in the near-surface water occur during low-flow periods in the bathing season.
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Borchardt, Mark A; Haas, Nathaniel L; Hunt, Randall J
2004-10-01
Human enteric viruses can contaminate municipal drinking-water wells, but few studies have examined the routes by which viruses enter these wells. In the present study, the objective was to monitor the municipal wells of La Crosse, Wisconsin, for enteric viruses and determine whether the amount of Mississippi River water infiltrating the wells was related to the frequency of virus detection. From March 2001 to February 2002, one river water site and four wells predicted by hydrogeological modeling to have variable degrees of surface water contributions were sampled monthly for enteric viruses, microbial indicators of sanitary quality, and oxygen and hydrogen isotopes. (18)O/(16)O and (2)H/(1)H ratios were used to determine the level of surface water contributions. All samples were collected prior to chlorination at the wellhead. By reverse transcription-PCR (RT-PCR), 24 of 48 municipal well water samples (50%) were positive for enteric viruses, including enteroviruses, rotavirus, hepatitis A virus (HAV), and noroviruses. Of 12 river water samples, 10 (83%) were virus positive by RT-PCR. Viable enteroviruses were not detected by cell culture in the well samples, although three well samples were positive for culturable HAV. Enteroviruses detected in the wells by RT-PCR were identified as several serotypes of echoviruses and group A and group B coxsackieviruses. None of the well water samples was positive for indicators of sanitary quality, namely male-specific and somatic coliphages, total coliform bacteria, Escherichia coli, and fecal enterococci. Contrary to expectations, viruses were found in all wells regardless of the level of surface water contributions. This result suggests that there were other unidentified sources, in addition to surface water, responsible for the contamination.
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Borchardt, Mark A.; Haas, Nathaniel L.; Hunt, Randall J.
2004-01-01
Human enteric viruses can contaminate municipal drinking-water wells, but few studies have examined the routes by which viruses enter these wells. In the present study, the objective was to monitor the municipal wells of La Crosse, Wisconsin, for enteric viruses and determine whether the amount of Mississippi River water infiltrating the wells was related to the frequency of virus detection. From March 2001 to February 2002, one river water site and four wells predicted by hydrogeological modeling to have variable degrees of surface water contributions were sampled monthly for enteric viruses, microbial indicators of sanitary quality, and oxygen and hydrogen isotopes. 18O/16O and 2H/1H ratios were used to determine the level of surface water contributions. All samples were collected prior to chlorination at the wellhead. By reverse transcription-PCR (RT-PCR), 24 of 48 municipal well water samples (50%) were positive for enteric viruses, including enteroviruses, rotavirus, hepatitis A virus (HAV), and noroviruses. Of 12 river water samples, 10 (83%) were virus positive by RT-PCR. Viable enteroviruses were not detected by cell culture in the well samples, although three well samples were positive for culturable HAV. Enteroviruses detected in the wells by RT-PCR were identified as several serotypes of echoviruses and group A and group B coxsackieviruses. None of the well water samples was positive for indicators of sanitary quality, namely male-specific and somatic coliphages, total coliform bacteria, Escherichia coli, and fecal enterococci. Contrary to expectations, viruses were found in all wells regardless of the level of surface water contributions. This result suggests that there were other unidentified sources, in addition to surface water, responsible for the contamination. PMID:15466536
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Borchardt, M. A.; Haas, N.L.; Hunt, R.J.
2004-01-01
Human enteric viruses can contaminate municipal drinking-water wells, but few studies have examined the routes by which viruses enter these wells. In the present study, the objective was to monitor the municipal wells of La Crosse, Wisconsin, for enteric viruses and determine whether the amount of Mississippi River water infiltrating the wells was related to the frequency of virus detection. From March 2001 to February 2002, one river water site and four wells predicted by hydrogeological modeling to have variable degrees of surface water contributions were sampled monthly for enteric viruses, microbial indicators of sanitary quality, and oxygen and hydrogen isotopes. 18O/ 16O and 2H/1H ratios were used to determine the level of surface water contributions. All samples were collected prior to chlorination at the wellhead. By reverse transcription-PCR (RT-PCR), 24 of 48 municipal well water samples (50%) were positive for enteric viruses, including enteroviruses, rotavirus, hepatitis A virus (HAV), and noroviruses. Of 12 river water samples, 10 (83%) were virus positive by RT-PCR. Viable enteroviruses were not detected by cell culture in the well samples, although three well samples were positive for culturable HAV. Enteroviruses detected in the wells by RT-PCR were identified as several serotypes of echoviruses and group A and group B coxsackieviruses. None of the well water samples was positive for indicators of sanitary quality, namely male-specific and somatic coliphages, total coliform bacteria, Escherichia coli, and fecal enterococci. Contrary to expectations, viruses were found in all wells regardless of the level of surface water contributions. This result suggests that there were other unidentified sources, in addition to surface water, responsible for the contamination.
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Hormone and pathogen content in soil after litter applications
USDA-ARS?s Scientific Manuscript database
Poultry litter applications at agronomic rates established for a crop’s P or N requirements may contain as much as 385 mg estradiol ha-1, 605 mg testosterone ha-1, 4.4(10)12 Escherichia coli cells ha-1, and 4.4(10)13 fecal enterococci cells ha-1. Field experiments from small plot- to small watershed...
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Beach water quality monitoring is an important tool to inform the public of health risks from recreational beach use, as well as to assess the impacts of land-based sources of pollution on coastal ecosystems. Many beach monitoring programs in the US currently utilize a strategy o...
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Tales of conjugation and sex pheromones
2011-01-01
This review covers highlights of the author's experience becoming and working as a plasmid biologist. The account chronicles a progression from studies of ColE1 DNA in Escherichia coli to Gram-positive bacteria with an emphasis on conjugation in enterococci. It deals with gene amplification, conjugative transposons and sex pheromones in the context of bacterial antibiotic resistance. PMID:22016844
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In order to effectively control inputs of contamination to coastal recreational waters, an improved understanding of the impact of both point and non-point sources of urban runoff is needed. In this study, we focused on the effect of non-point source urban runoff on the enterococ...
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7 CFR 58.346 - Whipped butter.
Code of Federal Regulations, 2010 CFR
2010-01-01
... count, not more than 50 per gram; yeast and mold count, not more than 10 per gram; coliform count, not more than 10 per gram; and keeping-quality test, satisfactory after 7 days at 72 °F. (2) Optional... ppm; enterococci, not more than 10 per gram. [59 FR 1264, Jan. 10, 1994, as amended at 67 FR 48976...
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7 CFR 58.346 - Whipped butter.
Code of Federal Regulations, 2013 CFR
2013-01-01
... count, not more than 50 per gram; yeast and mold count, not more than 10 per gram; coliform count, not more than 10 per gram; and keeping-quality test, satisfactory after 7 days at 72 °F. (2) Optional... ppm; enterococci, not more than 10 per gram. [59 FR 1264, Jan. 10, 1994, as amended at 67 FR 48976...
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7 CFR 58.346 - Whipped butter.
Code of Federal Regulations, 2011 CFR
2011-01-01
... count, not more than 50 per gram; yeast and mold count, not more than 10 per gram; coliform count, not more than 10 per gram; and keeping-quality test, satisfactory after 7 days at 72 °F. (2) Optional... ppm; enterococci, not more than 10 per gram. [59 FR 1264, Jan. 10, 1994, as amended at 67 FR 48976...
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7 CFR 58.346 - Whipped butter.
Code of Federal Regulations, 2014 CFR
2014-01-01
... count, not more than 50 per gram; yeast and mold count, not more than 10 per gram; coliform count, not more than 10 per gram; and keeping-quality test, satisfactory after 7 days at 72 °F. (2) Optional... ppm; enterococci, not more than 10 per gram. [59 FR 1264, Jan. 10, 1994, as amended at 67 FR 48976...
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7 CFR 58.346 - Whipped butter.
Code of Federal Regulations, 2012 CFR
2012-01-01
... count, not more than 50 per gram; yeast and mold count, not more than 10 per gram; coliform count, not more than 10 per gram; and keeping-quality test, satisfactory after 7 days at 72 °F. (2) Optional... ppm; enterococci, not more than 10 per gram. [59 FR 1264, Jan. 10, 1994, as amended at 67 FR 48976...
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Microbial source tracking (MST) is based on the assumption that specific strains of bacteria are associated with specific host species. MST methods are attractive because their application on environmental samples could help define the nature of water quality problems in impaire...
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Federal Register 2010, 2011, 2012, 2013, 2014
2010-03-08
...-disrupting compounds); and pathogen indicators (i.e., E. coli, enterococci, fecal coliforms). EPA found that... submitting comments. E-mail: [email protected] v Attention Docket ID No. OW-2009- 0208. Mail: Water Docket... or e-mail. The http://www.regulations.gov Web site is an ``anonymous access'' system, which means EPA...
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40 CFR 141.402 - Ground water source microbial monitoring and analytical methods.
Code of Federal Regulations, 2011 CFR
2011-07-01
... approves the use of E. coli as a fecal indicator for source water monitoring under this paragraph (a). If the repeat sample collected from the ground water source is E.coli positive, the system must comply... listed in the in paragraph (c)(2) of this section for the presence of E. coli, enterococci, or coliphage...
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Genthner, Fred J., Joseph B. James, Diane F. Yates and Stephanie D. Friedman. Submitted. Use of Composite Data Sets for Source-Tracking Enterococci in the Water Column and Shoreline Interstitial Waters on Pensacola Beach Florida. Mar. Pollut. Bull. 33 p. (ERL,GB 1212).
So... -
40 CFR 141.402 - Ground water source microbial monitoring and analytical methods.
Code of Federal Regulations, 2013 CFR
2013-07-01
... for the presence of E. coli, enterococci, or coliphage: Analytical Methods for Source Water Monitoring... Microbiology, 62:3881-3884. 10 EPA Method 1601: Male-specific (F+) and Somatic Coliphage in Water by Two-step... 20460. 11 EPA Method 1602: Male-specific (F+) and Somatic Coliphage in Water by Single Agar Layer (SAL...
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40 CFR 141.402 - Ground water source microbial monitoring and analytical methods.
Code of Federal Regulations, 2014 CFR
2014-07-01
... for the presence of E. coli, enterococci, or coliphage: Analytical Methods for Source Water Monitoring... Microbiology, 62:3881-3884. 10 EPA Method 1601: Male-specific (F+) and Somatic Coliphage in Water by Two-step... 20460. 11 EPA Method 1602: Male-specific (F+) and Somatic Coliphage in Water by Single Agar Layer (SAL...
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Real-time single-molecule observations of proteins at the solid-liquid interface
NASA Astrophysics Data System (ADS)
Langdon, Blake Brianna
Non-specific protein adsorption to solid surfaces is pervasive and observed across a broad spectrum of applications including biomaterials, separations, pharmaceuticals, and biosensing. Despite great interest in and considerable literature dedicated to the phenomena, a mechanistic understanding of this complex phenomena is lacking and remains controversial, partially due to the limits of ensemble-averaging techniques used to study it. Single-molecule tracking (SMT) methods allow us to study distinct protein dynamics (e.g. adsorption, desorption, diffusion, and intermolecular associations) on a molecule-by-molecule basis revealing the protein population and spatial heterogeneity inherent in protein interfacial behavior. By employing single-molecule total internal reflection fluorescence microscopy (SM-TIRFM), we have developed SMT methods to directly observe protein interfacial dynamics at the solid-liquid interface to build a better mechanistic understanding of protein adsorption. First, we examined the effects of surface chemistry (e.g. hydrophobicity, hydrogen-bonding capacity), temperature, and electrostatics on isolated protein desorption and interfacial diffusion for fibrinogen (Fg) and bovine serum albumin (BSA). Next, we directly and indirectly probed the effects of protein-protein interactions on interfacial desorption, diffusion, aggregation, and surface spatial heterogeneity on model and polymeric thin films. These studies provided many useful insights into interfacial protein dynamics including the following observations. First, protein adsorption was reversible, with the majority of proteins desorbing from all surface chemistries within seconds. Isolated protein-surface interactions were relatively weak on both hydrophobic and hydrophilic surfaces (apparent desorption activation energies of only a few kBT). However, proteins could dynamically and reversibly associate at the interface, and these interfacial associations led to proteins remaining on the surface for longer time intervals. Surface chemistry and surface spatial heterogeneity (i.e. surface sites with different binding strengths) were shown to influence adsorption, desorption, and interfacial protein-protein associations. For example, faster protein diffusion on hydrophobic surfaces increased protein-protein associations and, at higher protein surface coverage, led to proteins remaining on hydrophobic surfaces longer than on hydrophilic surfaces. Ultimately these studies suggested that surface properties (chemistry, heterogeneity) influence not only protein-surface interactions but also interfacial mobility and protein-protein associations, implying that surfaces that better control protein adsorption can be designed by accounting for these processes.
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NASA Astrophysics Data System (ADS)
Downs, Emily Elizabeth
Protein-nanostructure conjugates, particularly particles, are a subject of significant interest due to changes in their fundamental behavior compared to bulk surfaces. As the size scale of nano-structured materials and proteins are on the same order of magnitude, nanomaterial properties can heavily influence how proteins adsorb and conform to the surface. Previous work has demonstrated the ability of nanoscale surfaces to modulate protein activity, conformation, and retention by modifying the particle surface curvature, morphology, and surface charge. This work has improved our understanding of the protein material interactions, but a complete understanding is still lacking. The goal of this thesis is to investigate two missing areas of understanding using two distinct systems. The first system utilizes a particle with controlled surface energy to observe the impact of surface energy on protein-particle interactions, while the second system uses a modified Listeria-specific protein to determine how protein structure and flexibility affects protein adsorption and activity on particles. Spherical, amorphous, and uniformly doped Zn-silica particles with tailored surface energies were synthesized to understand the impact of surface energy on protein adsorption behavior. Particle surface energy increased with a decrease in particle size and greater dopant concentrations. Protein adsorption and structural loss increased with both particle size and particle surface energy. Higher surface energies promoted protein-particle association and increased protein unfolding. Particle curvature and protein steric hindrance effects limited adsorption and structural loss on smaller particles. Protein surface charge heterogeneity was also found to be linked to both protein adsorption and unfolding behavior on larger particles. Greater surface charge heterogeneity led to higher adsorption concentrations and multilayer formation. These multilayers transitioned from protein-particle interactions to protein-protein interactions and were thicker with greater surface energy, which resulted in the recovery of secondary structure in the outermost layer. To help understand the impact of protein structure on nano-bio conjugate interactions, a listeria specific protein was used. This system was chosen as it has applications in the food industry in preventing bacterial contamination. The insertion of an amino acid linker between the enzymatic and binding domain of the protein improved the flexibility between domains, leading to increased adsorption, and improved activity in both cell-wall and plating assays. Additionally, linker modified protein incorporated into the silica-polymer nanocomposite showed significant activity in a real-world example of contaminated lettuce. This thesis study has isolated the impact of surface energy and protein flexibility on protein adsorption and structure. Particle surface energy affects adsorbed protein concentration and conformation. Coupled with protein surface charge, surface energy was also found to dictate multilayer thickness. The conformational flexibility of the protein was shown to help in controlling not only protein adsorption concentration but also in retaining protein activity after immobilization. Also, a controllable synthesis method for particles with adjustable surface energy, an ideal platform for studying protein-particle interactions, has been established.
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Detection of hepatitis E virus and other livestock-related pathogens in Iowa streams
Givens, Carrie E.; Kolpin, Dana W.; Borchardt, Mark A.; Duris, Joseph W.; Moorman, Thomas B.; Spencer, Susan K.
2016-01-01
Manure application is a source of pathogens to the environment. Through overland runoff and tile drainage, zoonotic pathogens can contaminate surface water and streambed sediment and could affect both wildlife and human health. This study examined the environmental occurrence of gene markers for livestock-related bacterial, protozoan, and viral pathogens and antibiotic resistance in surface waters within the South Fork Iowa River basin before and after periods of swine manure application on agricultural land. Increased concentrations of indicator bacteria after manure application exceeding Iowa's state bacteria water quality standards suggest that swine manure contributes to diminished water quality and may pose a risk to human health. Additionally, the occurrence of HEV and numerous bacterial pathogen genes for Escherichia coli, Enterococcus spp., Salmonella sp., and Staphylococcus aureus in both manure samples and in corresponding surface water following periods of manure application suggests a potential role for swine in the spreading of zoonotic pathogens to the surrounding environment. During this study, several zoonotic pathogens were detected including Shiga-toxin producing E. coli, Campylobacter jejuni, pathogenic enterococci, and S. aureus; all of which can pose mild to serious health risks to swine, humans, and other wildlife. This research provides the foundational understanding required for future assessment of the risk to environmental health from livestock-related zoonotic pathogen exposures in this region. This information could also be important for maintaining swine herd biosecurity and protecting the health of wildlife near swine facilities.
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Vancomycin-Resistance Enterococci Infections in the Department of the Defense: Annual Report 2014
2015-07-22
change in 2014 as VRE continues to predominately affect elderly females and manifest as urinary tract infections ( UTIs ). In addition, antibiotic...urinary tract infections ( UTIs ). In addition, antibiotic susceptibility patterns did not substantially change in 2014. Daptomycin, linezolid and...the infection continues to predominately affect elderly females and manifest as UTIs . In addition, antibiotic susceptibility patterns did not
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Treatment of Mycobacterium intracellulare Infected Mice with Walter Reed Compound H
1980-09-25
including Mycobacterium tuberculosis, Mycobacterium leprae , Staphylococcusaureus, Pseudomonas aeruginosa, Escherichia coli, enterococ----ci, Neissr•~n...97 SAD "Treatment of Mycobacterium intracellulare Infected Mice with Walter Reed Compound H" Final Comprehensive Report J. Kenneth McClatchy, Ph.D...REPORT & PERIOD COVERED "TREATMENT OF MYCOBACTERIUM INTRACELLULARE - Final Comprehensive Report INFECTED MICE WITH WALTER REED COMPOUND H"li G
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40 CFR 141.202 - Tier 1 Public Notice-Form, manner, and frequency of notice.
Code of Federal Regulations, 2010 CFR
2010-07-01
... fecal coliform or E. coli are present in the water distribution system (as specified in § 141.63(b)), or when the water system fails to test for fecal coliforms or E. coli when any repeat sample tests...) Detection of E. coli, enterococci, or coliphage in source water samples as specified in § 141.402(a) and...
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40 CFR 141.202 - Tier 1 Public Notice-Form, manner, and frequency of notice.
Code of Federal Regulations, 2011 CFR
2011-07-01
... fecal coliform or E. coli are present in the water distribution system (as specified in § 141.63(b)), or when the water system fails to test for fecal coliforms or E. coli when any repeat sample tests...) Detection of E. coli, enterococci, or coliphage in source water samples as specified in § 141.402(a) and...
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USDA-ARS?s Scientific Manuscript database
Application of manure from swine treated with antibiotics introduces antibiotics and antibiotic resistance genes to soil with the potential for further movement in drainage water. Manure concentrations for ermB, ermC and ermF were all >109 copy g-1. Manure contained 1.76 x 105 CFUg-1 enterococci w...
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Interstitial water in the swash zone, that area of a beach where waves continuously wash up on the sand, is suspected of accumulating microbes. If pathogens are concentrated in the interstitial water or if they grow, they may pose a health risk, especially for children. This st...
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Kellogg, Stephanie L; Little, Jaime L; Hoff, Jessica S; Kristich, Christopher J
2017-05-01
Enterococci are serious opportunistic pathogens that are resistant to many cell wall-targeting antibiotics. The CroRS two-component signaling system responds to antibiotic-mediated cell wall stress and is critical for resistance to cell wall-targeting antibiotics in Enterococcus faecalis Here, we identify and characterize an orthologous two-component system found in Enterococcus faecium that is functionally equivalent to the CroRS system of E. faecalis Deletion of croRS in E. faecium resulted in marked susceptibility to cell wall-targeting agents including cephalosporins and bacitracin, as well as moderate susceptibility to ampicillin and vancomycin. As in E. faecalis , exposure to bacitracin and vancomycin stimulates signaling through the CroRS system in E. faecium Moreover, the CroRS system is critical in E. faecium for enhanced beta-lactam resistance mediated by overexpression of Pbp5. Expression of a Pbp5 variant that confers enhanced beta-lactam resistance cannot overcome the requirement for CroRS function. Thus, the CroRS system is a conserved signaling system that responds to cell wall stress to promote intrinsic resistance to important cell wall-targeting antibiotics in clinically relevant enterococci. Copyright © 2017 American Society for Microbiology.
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Mika, K.B.; Imamura, G.; Chang, C.; Conway, V.; Fernandez, G.; Griffith, J.F.; Kampalath, R.A.; Lee, C.M.; Lin, C.-C.; Moreno, R.; Thompson, S.; Whitman, R.L.; Jay, J.A.
2009-01-01
Aim: Factors affecting faecal indicator bacteria (FIB) and pathogen survival/persistence in sand remain largely unstudied. This work elucidates how biological and physical factors affect die-off in beach sand following sewage spills. Methods and Results: Solar disinfection with mechanical mixing was pilot-tested as a disinfection procedure after a large sewage spill in Los Angeles. Effects of solar exposure, mechanical mixing, predation and/or competition, season, and moisture were tested at bench scale. First-order decay constants for Escherichia coli ranged between -0??23 and -1??02 per day, and for enterococci between -0??5 and -1??0 per day. Desiccation was a dominant factor for E. coli but not enterococci inactivation. Effects of season were investigated through a comparison of experimental results from winter, spring, and fall. Conclusions: Moisture was the dominant factor controlling E. coli inactivation kinetics. Initial microbial community and sand temperature were also important factors. Mechanical mixing, common in beach grooming, did not consistently reduce bacterial levels. Significance and Impact of the Study: Inactivation rates are mainly dependent on moisture and high sand temperature. Chlorination was an effective disinfection treatment in sand microcosms inoculated with raw influent. ?? 2009 The Society for Applied Microbiology.
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Choices in recreational water quality monitoring: new opportunities and health risk trade-offs.
Nevers, Meredith B; Byappanahalli, Muruleedhara N; Whitman, Richard L
2013-04-02
With the recent release of new recreational water quality monitoring criteria, there are more options for regulatory agencies seeking to protect beachgoers from waterborne pathogens. Included are methods that can reduce analytical time, providing timelier estimates of water quality, but the application of these methods has not been examined at most beaches for expectation of health risk and management decisions. In this analysis, we explore health and monitoring outcomes expected at Lake Michigan beaches using protocols for indicator bacteria including culturable Escherichia coli (E. coli; EC), culturable enterococci (ENT), and enterococci as analyzed by qPCR (QENT). Correlations between method results were generally high, except at beaches with historically high concentrations of EC. The "beach action value" was exceeded most often when using EC or ENT as the target indicator; QENT exceeded the limit far less frequently. Measured water quality between years was varied. Although methods with equivalent health expectation have been established, the lack of relationship among method outcomes and annual changes in mean indicator bacteria concentrations complicates the decision-making process. The monitoring approach selected by beach managers may be a combination of available tools that maximizes timely health protection, cost efficiency, and collaboration among beach jurisdictions.
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Kager, L; Liljeqvist, L; Malmborg, A S; Nord, C E
1981-01-01
Clindamycin was given intravenously to 15 patients undergoing colorectal surgery in an initial dose of 600 mg, given at induction of anesthesia followed by 6 doses of 600 mg at 8-h intervals. Series of serum samples and fecal specimens were taken for analysis of clindamycin concentrations. Tissue samples from the gut wall were taken at surgery. The highest serum concentrations observed occurred 30 min after administration of clindamycin and varied between 6.8 and 37.9 microgram/ml (mean, 14.8 +/- 2.0 [standard error] microgram/ml). The clindamycin concentrations in the tissue samples were between 1.8 and 13.0 microgram/g. Clindamycin concentration in the fecal samples varied between 2.1 and 460 microgram/g. Fecal samples were also collected during the investigation period for cultivation of aerobic and anaerobic bacteria. Among the aerobic bacteria, enterococci and streptococci decreased during the prophylaxis period. Anaerobic bacteria also decreased significantly during the same period. After the clindamycin administration period, enterococci, streptococci and anaerobic bacteria proliferated. No anaerobic strains resistant to clindamycin were isolated. Postoperative infections due to Streptococcus faecalis and different enterobacteria such as Escherichia coli, Enterobacter cloacae, Citrobacter freundii, and Klebsiella occurred in five patients. PMID:7325640
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Kager, L; Liljeqvist, L; Malmborg, A S; Nord, C E
1981-12-01
Clindamycin was given intravenously to 15 patients undergoing colorectal surgery in an initial dose of 600 mg, given at induction of anesthesia followed by 6 doses of 600 mg at 8-h intervals. Series of serum samples and fecal specimens were taken for analysis of clindamycin concentrations. Tissue samples from the gut wall were taken at surgery. The highest serum concentrations observed occurred 30 min after administration of clindamycin and varied between 6.8 and 37.9 microgram/ml (mean, 14.8 +/- 2.0 [standard error] microgram/ml). The clindamycin concentrations in the tissue samples were between 1.8 and 13.0 microgram/g. Clindamycin concentration in the fecal samples varied between 2.1 and 460 microgram/g. Fecal samples were also collected during the investigation period for cultivation of aerobic and anaerobic bacteria. Among the aerobic bacteria, enterococci and streptococci decreased during the prophylaxis period. Anaerobic bacteria also decreased significantly during the same period. After the clindamycin administration period, enterococci, streptococci and anaerobic bacteria proliferated. No anaerobic strains resistant to clindamycin were isolated. Postoperative infections due to Streptococcus faecalis and different enterobacteria such as Escherichia coli, Enterobacter cloacae, Citrobacter freundii, and Klebsiella occurred in five patients.
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Kellogg, Stephanie L.; Little, Jaime L.; Hoff, Jessica S.
2017-01-01
ABSTRACT Enterococci are serious opportunistic pathogens that are resistant to many cell wall-targeting antibiotics. The CroRS two-component signaling system responds to antibiotic-mediated cell wall stress and is critical for resistance to cell wall-targeting antibiotics in Enterococcus faecalis. Here, we identify and characterize an orthologous two-component system found in Enterococcus faecium that is functionally equivalent to the CroRS system of E. faecalis. Deletion of croRS in E. faecium resulted in marked susceptibility to cell wall-targeting agents including cephalosporins and bacitracin, as well as moderate susceptibility to ampicillin and vancomycin. As in E. faecalis, exposure to bacitracin and vancomycin stimulates signaling through the CroRS system in E. faecium. Moreover, the CroRS system is critical in E. faecium for enhanced beta-lactam resistance mediated by overexpression of Pbp5. Expression of a Pbp5 variant that confers enhanced beta-lactam resistance cannot overcome the requirement for CroRS function. Thus, the CroRS system is a conserved signaling system that responds to cell wall stress to promote intrinsic resistance to important cell wall-targeting antibiotics in clinically relevant enterococci. PMID:28223383
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An unusual case of infective endocarditis presenting as acute myocardial infarction.
Chen, Zhong; Ng, Francesca; Nageh, Thuraia
2007-06-01
A 39-year-old Zimbabwean man presented with a 1 week history of fever, general malaise and acute-onset chest pain. He had a urethral stricture, which had been managed with an indwelling supra-pubic catheter. The electrocardiography on admission showed inferior ST-T segments elevation. His chest pain and electrocardiography changes resolved subsequent to thrombolysis, and he remained haemodynamically stable. The 12-h troponin I was increased at 10.5 microg/l (NR <0.04 microg/l). Echocardiography confirmed severe mitral regurgitation and a flail anterior mitral valve leaflet with an independently oscillating mobile vegetation. Enterococci faecalis were grown on blood cultures. A diagnosis of enterococci infective endocarditis with concomitant acute myocardial infarction due to possible septic emboli was made. Despite the successful outcome from thrombolysis in the setting of acute myocardial infarction with infective endocarditis, the case highlights the current lack of definitive data on the optimal acute management of such an unusual clinical scenario. Although there is serious concern that thrombolytic treatment for myocardial infarction in the setting of infective endocarditis may be associated with higher risk of cerebral haemorrhage, there is little documented evidence supporting the safety of primary percutaneous coronary intervention with these patients.
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Rijal, G K; Fujioka, R S
2003-01-01
Aluminum reflectors were added to solar units designed to inactivate faecal microorganisms (faecal coliform, E. coli, enterococci, FRNA coliphage, C. perfringens) in stream water and diluted sewage by the two mechanisms (solar heat, solar UV) known to inactivate microorganisms. During sunny conditions, solar units with and without reflectors inactivated E. coli to <1 CFU/100 ml to meet drinking water standards. Solar units with reflectors disinfected the water sooner by increasing the water temperature by 8-10 degrees C to 64-75 degrees C. However, FRNA coliphages were still detected in these samples, indicating that this treatment may not inactivate pathogenic human enteric viruses. During cloudy conditions, reflectors only increased the water temperature by 3-4 degrees C to a maximum of 43-49 degrees C and E. coli was not completely inactivated. Under sunny and cloudy conditions, the UV wavelengths of sunlight worked synergistically with increasing water temperatures and were able to disinfect microorganisms at temperatures (45-56 degrees C), which were not effective in inactivating microorganisms. Relative resistance to the solar disinfecting effects were C. perfringens > FRNA coliphages > enterococci > E. coli > faecal coliform.
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[The intestinal microflora of persons subjected to a radiation lesion].
Sudenko, V I; Nagornaia, S S; Groma, L I
1992-01-01
The content of large intestine has been studied in persons exposed to radiation injury in consequence of the accident at the Chernobyl Atomic Power Plant. It is stated that bifidobacteria (10(7)-10(10) cells in 1 g of feces) prevailed (as in healthy people), Bifidobacterium indicum being a dominating species. Amount of lactic-acid bacteria in 1 g of defecations of examined patients was within the range of 10(6)-10(9) cells and in certain persons it reached 10(10) cells (primarily fecal Enterococci). A considerable amount of patients with acute radiation sickness of the 3d degree had in their intestine 10(9)/g of lactic-acid bacteria, Lactobacillus casei and L. plantarum prevailing there. The frequency of yeast isolation from defecations of patients constituted 83%, while the number of cells in 1 g of feces--from 10 to 10(4). Yeast of the Candida genus, mainly Candida parapsilosis, prevailed. The species composition of isolated microorganisms has no substantial differences from microcenosis of healthy people. The content of intestine of persons suffered from radiation is characterized only by greater amount of lactic-acid bacteria and enterococci as compared with healthy adults.
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Assessment of clinical significance of positive blood cultures of relatively low-virulence isolates.
Hirakata, Y; Furuya, N; Iwata, M; Kashitani, F; Ishikawa, M; Yumoto, S; Yasui, K; Endoh, H; Marui, A; Kaku, M; Tateda, K; Yamaguchi, K
1996-03-01
In Omori Hospital, Toho University School of Medicine, relatively low-virulence blood isolates, including coagulase-negative staphylococci (CNS), enterococci and nonfermentative gram-negative rods other than Pseudomonas aeruginosa comprised c. 60% of total blood isolates. A retrospective study was conducted to assess their clinical significance by reviewing a total of 91 hospital charts. The physicians' assessments of these positive blood cultures as recorded in the charts were classified into four categories--sepsis, possible sepsis, contamination and no comment. The episodes classified as sepsis accounted for 5.0-19.6%. These episodes were also evaluated by a graded clinical significance score based on multiple factors, including number of positive cultures and clinical signs. The scores for the 91 episodes covered a wide range from 1 to 9, indicating that both contaminants and causative organisms may have been involved. The episodes judged as sepsis or possible sepsis tended to have higher scores. The scores for the episodes associated with enterococci were also higher than those involving CNS or non-fermentative gram-negative rods. The scores for episodes associated with intravenous hyperalimentation catheters were higher than those not associated with the catheters.
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Multiple approaches to microbial source tracking in tropical northern Australia
Neave, Matthew; Luter, Heidi; Padovan, Anna; Townsend, Simon; Schobben, Xavier; Gibb, Karen
2014-01-01
Microbial source tracking is an area of research in which multiple approaches are used to identify the sources of elevated bacterial concentrations in recreational lakes and beaches. At our study location in Darwin, northern Australia, water quality in the harbor is generally good, however dry-season beach closures due to elevated Escherichia coli and enterococci counts are a cause for concern. The sources of these high bacteria counts are currently unknown. To address this, we sampled sewage outfalls, other potential inputs, such as urban rivers and drains, and surrounding beaches, and used genetic fingerprints from E. coli and enterococci communities, fecal markers and 454 pyrosequencing to track contamination sources. A sewage effluent outfall (Larrakeyah discharge) was a source of bacteria, including fecal bacteria that impacted nearby beaches. Two other treated effluent discharges did not appear to influence sites other than those directly adjacent. Several beaches contained fecal indicator bacteria that likely originated from urban rivers and creeks within the catchment. Generally, connectivity between the sites was observed within distinct geographical locations and it appeared that most of the bacterial contamination on Darwin beaches was confined to local sources. PMID:25224738
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Choices in recreational water quality monitoring: new opportunities and health risk trade-offs
Nevers, Meredith B.; Byappanahalli, Muruleedhara N.; Whitman, Richard L.
2013-01-01
With the recent release of new recreational water quality monitoring criteria, there are more options for regulatory agencies seeking to protect beachgoers from waterborne pathogens. Included are methods that can reduce analytical time, providing timelier estimates of water quality, but the application of these methods has not been examined at most beaches for expectation of health risk and management decisions. In this analysis, we explore health and monitoring outcomes expected at Lake Michigan beaches using protocols for indicator bacteria including culturable Escherichia coli (E. coli; EC), culturable enterococci (ENT), and enterococci as analyzed by qPCR (QENT). Correlations between method results were generally high, except at beaches with historically high concentrations of EC. The “beach action value” was exceeded most often when using EC or ENT as the target indicator; QENT exceeded the limit far less frequently. Measured water quality between years was varied. Although methods with equivalent health expectation have been established, the lack of relationship among method outcomes and annual changes in mean indicator bacteria concentrations complicates the decision-making process. The monitoring approach selected by beach managers may be a combination of available tools that maximizes timely health protection, cost efficiency, and collaboration among beach jurisdictions.
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Infrequent occurrence of vancomycin-resistant enterococci in poultry from Malaysian wet markets.
Ong, C H S; Asaad, M; Lim, K C; Ngeow, Y F
2002-12-01
Fifty samples of chicken, duck and geese faeces were obtained from 13 wet markets in Kuala Lumpur to study the prevalence of vancomycin-resistant enterococci (VRE) among local market poultry. Biotyping of colonies grown on azide agar incubated at 45 degrees C yielded E. pseudoavium, E. faecalis, E. faecium and E. gallinarum from chicken faeces and E. malodoratus, E. faecalis, E. faecium, E. gallinarum, E. hirae/dispar, and E. durans from goose and duck faeces. On agar containing 6 mg/ l of vancomycin, one strain of E. flavescens was identified, giving a VRE detection rate of 2.0%. This isolate had a vancomycin M.I.C. of 8 mg/l as determined by the Etest, and the van C-3 gene that was identified by PCR followed by sequence analysis. The prevalence of VRE among poultry sold in local markets appears to be low, and may reflect the infrequent use of antimicrobials in our poultry farms. Nevertheless, the possibility of human acquisition of microbes via the food chain cautions against the use of antimicrobials in animal husbandry that may encourage the emergence and spread of multi-drug resistant organisms like the VRE among animal microbial flora.
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A periplasmic D-alanyl-D-alanine dipeptidase in the gram-negative bacterium Salmonella enterica.
Hilbert, F; García-del Portillo, F; Groisman, E A
1999-04-01
The VanX protein is a D-alanyl-D-alanine (D-Ala-D-Ala) dipeptidase essential for resistance to the glycopeptide antibiotic vancomycin. While this enzymatic activity has been typically associated with vancomycin- and teicoplainin-resistant enterococci, we now report the identification of a D-Ala-D-Ala dipeptidase in the gram-negative species Salmonella enterica. The Salmonella enzyme is only 36% identical to VanX but exhibits a similar substrate specificity: it hydrolyzes D-Ala-D-Ala, DL-Ala-DL-Phe, and D-Ala-Gly but not the tripeptides D-Ala-D-Ala-D-Ala and DL-Ala-DL-Lys-Gly or the dipeptides L-Ala-L-Ala, N-acetyl-D-Ala-D-Ala, and L-Leu-Pro. The Salmonella dipeptidase gene, designated pcgL, appears to have been acquired by horizontal gene transfer because pcgL-hybridizing sequences were not detected in related bacterial species and the G+C content of the pcgL-containing region (41%) is much lower than the overall G+C content of the Salmonella chromosome (52%). In contrast to wild-type Salmonella, a pcgL mutant was unable to use D-Ala-D-Ala as a sole carbon source. The pcgL gene conferred D-Ala-D-Ala dipeptidase activity upon Escherichia coli K-12 but did not allow growth on D-Ala-D-Ala. The PcgL protein localizes to the periplasmic space of Salmonella, suggesting that this dipeptidase participates in peptidoglycan metabolism.
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Water at protein surfaces studied with femtosecond nonlinear spectroscopy
NASA Astrophysics Data System (ADS)
Bakker, Huib J.
We report on an investigation of the structure and dynamics of water molecules near protein surfaces with femtosecond nonlinear spectroscopic techniques. We measured the reorientation dynamics of water molecules near the surface of several globular protein surfaces, using polarization-resolved femtosecond infrared spectroscopy. We found that water molecules near the protein surface have a much slower reorientation than water molecules in bulk liquid water. The number of slow water molecules scales scales with the size of the hydrophobic surface of the protein. When we denature the proteins by adding an increasing amount of urea to the protein solution, we observe that the water-exposed surface increases by 50% before the secondary structure of the proteins changes. This finding indicates that protein unfolding starts with the protein structure becoming less tight, thereby allowing water to enter. With surface vibrational sum frequency generation (VSFG) spectroscopy, we studied the structure of water at the surface of antifreeze protein III. The measured VSFG spectra showed the presence of ice-like water layers at the ice-binding site of the protein in aqueous solution, at temperatures well above the freezing point. This ordered ice-like hydration layers at the protein surface likely plays an important role in the specific recognition and binding of anti-freeze protein III to nascent ice crystallites, and thus in its anti-freeze mechanism. This research is supported by the ''Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO).
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Modulation of protein stability and aggregation properties by surface charge engineering.
Raghunathan, Govindan; Sokalingam, Sriram; Soundrarajan, Nagasundarapandian; Madan, Bharat; Munussami, Ganapathiraman; Lee, Sun-Gu
2013-09-01
An attempt to alter protein surface charges through traditional protein engineering approaches often affects the native protein structure significantly and induces misfolding. This limitation is a major hindrance in modulating protein properties through surface charge variations. In this study, as a strategy to overcome such a limitation, we attempted to co-introduce stabilizing mutations that can neutralize the destabilizing effect of protein surface charge variation. Two sets of rational mutations were designed; one to increase the number of surface charged amino acids and the other to decrease the number of surface charged amino acids by mutating surface polar uncharged amino acids and charged amino acids, respectively. These two sets of mutations were introduced into Green Fluorescent Protein (GFP) together with or without stabilizing mutations. The co-introduction of stabilizing mutations along with mutations for surface charge modification allowed us to obtain functionally active protein variants (s-GFP(+15-17) and s-GFP(+5-6)). When the protein properties such as fluorescent activity, folding rate and kinetic stability were assessed, we found the possibility that the protein stability can be modulated independently of activity and folding by engineering protein surface charges. The aggregation properties of GFP could also be altered through the surface charge engineering.
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Arias, C A; Martín-Martinez, M; Blundell, T L; Arthur, M; Courvalin, P; Reynolds, P E
1999-03-01
Sequence determination of a region downstream from the vanXYc gene in Enterococcus gallinarum BM4174 revealed an open reading frame, designated vanT, that encodes a 698-amino-acid polypeptide with an amino-terminal domain containing 10 predicted transmembrane segments. The protein contained a highly conserved pyridoxal phosphate attachment site in the C-terminal domain, typical of alanine racemases. The protein was overexpressed in Escherichia coli, and serine racemase activity was detected in the membrane but not in the cytoplasmic fraction after centrifugation of sonicated cells, whereas alanine racemase activity was located almost exclusively in the cytoplasm. When the protein was overexpressed as a polypeptide lacking the predicted transmembrane domain, serine racemase activity was detected in the cytoplasm. The serine racemase activity was partially (64%) inhibited by D-cycloserine, whereas host alanine racemase activity was almost totally inhibited (97%). Serine racemase activity was also detected in membrane preparations of constitutively vancomycin-resistant E. gallinarum BM4174 but not in BM4175, in which insertional inactivation of the vanC-1 D-Ala:D-Ser ligase gene probably had a polar effect on expression of the vanXYc and vanT genes. Comparative modelling of the deduced C-terminal domain was based on the alignment of VanT with the Air alanine racemase from Bacillus stearothermophilus. The model revealed that almost all critical amino acids in the active site of Air were conserved in VanT, indicating that the C-terminal domain of VanT is likely to adopt a three-dimensional structure similar to that of Air and that the protein could exist as a dimer. These results indicate that the source of D-serine for peptidoglycan synthesis in vancomycin-resistant enterococci expressing the VanC phenotype involves racemization of L- to D-serine by a membrane-bound serine racemase.
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Millsap, K; Reid, G; van der Mei, H C; Busscher, H J
1994-01-01
The displacement of Enterococcus faecalis 1131 from hydrophobic and hydrophilic substrata by isolates of Lactobacillus casei 36 and Streptococcus hyointestinalis KM1 was studied in a parallel plate flow chamber. The experiments were conducted with either 10 mM potassium phosphate buffer or human urine as the suspending fluid, and adhesion and displacement were measured by real-time in situ image analysis. The results showed that E. faecalis 1131 was displaced by lactobacilli (31%) and streptococci (74%) from fluorinated ethylene propylene in buffer and that displacement by lactobacilli was even more effective on a glass substratum in urine (54%). The passage of an air-liquid interface significantly impacted on adhesion, especially when the surface had been challenged with lactobacilli (up to 100% displacement) or streptococci (up to 94% displacement). These results showed that the parallel plate flow system with real-time in situ image analysis was effective for studying bacterial adhesion and that uropathogenic enterococci can be displaced by indigenous bacteria. Images PMID:8031082
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Sathishkumar, Gnanasekar; Gobinath, Chandrakasan; Karpagam, Karuppiah; Hemamalini, Vedagiri; Premkumar, Kumpati; Sivaramakrishnan, Sivaperumal
2012-06-15
Leaf extract of Morinda citrifolia L. was assessed for the synthesis of silver nanoscale particles under different temperature and reaction time. Synthesized nanoscale (MCAgNPs) particles were confirmed by analysing the excitation of surface plasmon resonance (SPR) using UV-visible spectrophotometer at 420 nm. Further SEM, HRTEM analysis confirmed the range of particle size between 10 and 60 nm and SEAD pattern authorizes the face centered cubic (fcc) crystalline nature of the MCAgNPs. Fourier transform infrared spectrum (FTIR) of synthesized MCAgNPs confirms the presence of high amount of phenolic compounds in the plant extract which may possibly influence the reduction process and stabilization of nanoparticles. Further, inhibitory activity of MCAgNPs and plant extract were tested against human pathogens like Eschericia coli, Pseudomonas aeroginosa, Klebsiella pneumoniae, Enterobacter aerogenes, Bacillus cereus and Enterococci sp. The results indicated that the MCAgNPs showed moderate inhibitory actions against human pathogens than crude plant extract, demonstrating its antimicrobial value against pathogenic diseases. Copyright © 2012 Elsevier B.V. All rights reserved.
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Giske, Christian G.; Haldorsen, Bjørg; Matuschek, Erika; Schønning, Kristian; Leegaard, Truls M.; Kahlmeter, Gunnar
2014-01-01
Different antimicrobial susceptibility testing methods to detect low-level vancomycin resistance in enterococci were evaluated in a Scandinavian multicenter study (n = 28). A phenotypically and genotypically well-characterized diverse collection of Enterococcus faecalis (n = 12) and Enterococcus faecium (n = 18) strains with and without nonsusceptibility to vancomycin was examined blindly in Danish (n = 5), Norwegian (n = 13), and Swedish (n = 10) laboratories using the EUCAST disk diffusion method (n = 28) and the CLSI agar screen (n = 18) or the Vitek 2 system (bioMérieux) (n = 5). The EUCAST disk diffusion method (very major error [VME] rate, 7.0%; sensitivity, 0.93; major error [ME] rate, 2.4%; specificity, 0.98) and CLSI agar screen (VME rate, 6.6%; sensitivity, 0.93; ME rate, 5.6%; specificity, 0.94) performed significantly better (P = 0.02) than the Vitek 2 system (VME rate, 13%; sensitivity, 0.87; ME rate, 0%; specificity, 1). The performance of the EUCAST disk diffusion method was challenged by differences in vancomycin inhibition zone sizes as well as the experience of the personnel in interpreting fuzzy zone edges as an indication of vancomycin resistance. Laboratories using Oxoid agar (P < 0.0001) or Merck Mueller-Hinton (MH) agar (P = 0.027) for the disk diffusion assay performed significantly better than did laboratories using BBL MH II medium. Laboratories using Difco brain heart infusion (BHI) agar for the CLSI agar screen performed significantly better (P = 0.017) than did those using Oxoid BHI agar. In conclusion, both the EUCAST disk diffusion and CLSI agar screening methods performed acceptably (sensitivity, 0.93; specificity, 0.94 to 0.98) in the detection of VanB-type vancomycin-resistant enterococci with low-level resistance. Importantly, use of the CLSI agar screen requires careful monitoring of the vancomycin concentration in the plates. Moreover, disk diffusion methodology requires that personnel be trained in interpreting zone edges. PMID:24599985
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Vancomycin tolerance in enterococci.
Saribas, Suat; Bagdatli, Yasar
2004-11-01
Tolerance can be defined as the ability of bacteria to grow in the presence of high concentrations of bactericide antimicrobics, so that the killing action of the drug is avoided but the minimal inhibitory concentration (MIC) remains the same. We investigated vancomycin tolerance in the Enterococcus faecium and Enterococcus faecalis strains isolated from different clinical specimens. Vancomycin was obtained from Sigma Chemical Co. We studied 100 enterococci strains. Fifty-six and 44 of Enterococcus strains were idendified as E. feacalis and E. faecium, respectively. To determine MICs and minimal bactericidal concentration (MBC), we inoculated strains from an overnight agar culture to Muller-Hinton broth and incubated them for 4-6 h at 37 degrees C with shaking to obtain a logarithmic phase culture. The inoculum was controlled by performing a colony count for each test. We determined MBC values and MBC/MIC ratios to study tolerance to vancomycin. Vancomycin tolerance was defined as a high MBC value and an MBC/MIC ratio > or =32. Fifty-six and 44 of the Enterococcus strains were identified as E. faecium and E. faecalis, respectively. Thirty-one E. faecium and 48 E. faecalis were found to be susceptible to vancomycin and these susceptible strains were included in this study. The MICs of susceptible strains ranged from < or =1 to 4 mg/l, the MBCs were > or =512 mg/l. Tolerance was detected in all E. faecalis and E. faecium strains. The standard E. faecalis 21913 strain also exhibited tolerance according to the high MBC value and the MBC/MIC ratio. We defined the tolerant strains as having no bactericidal effect and MBC/MIC > or =32. We found that a 100% tolerance was present in susceptible strains. One of the hypotheses for tolerance is that tolerant cells fail to mobilize or create the autolysins needed for enlargement and division. Our data suggests that tolerance may compromise glycopeptide therapy of serious enterococci infections. To add an aminoglycoside to the glycopeptide therapy unless MBCs are unavailable can be useful in the effective treatment of serious Enterococcus infections.
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Lollai, S A; Ziccheddu, M; Duprè, I; Piras, D
2016-10-01
Mastitis causes economic losses and antimicrobials are frequently used for mastitis treatment. Antimicrobial resistance surveys are still rare in the ovine field and characterization of strains is important in order to acquire information about resistance and for optimization of therapy. Bacterial pathogens recovered in milk samples from mastitis-affected ewes were characterized for resistance to tetracyclines and aminoglycosides, members of which are frequently used antimicrobials in small ruminants. A total of 185 strains of staphylococci, streptococci, and enterococci, common mastitis pathogens, were tested for minimal inhibitory concentration (MIC) to tetracycline, doxycycline, minocycline, gentamicin, kanamycin, streptomycin, and for resistance genes by PCR. Effects of different tet genes arrangements on MICs were also investigated. Staphylococci expressed the lowest MIC for tetracycline and tet(K) was the most common gene recovered; tet(M) and tet(O) were also found. Gene content was shown to influence the tetracycline MIC values. Enterococci and streptococci showed higher MICs to tetracyclines and nonsusceptible strains always harboured at least one ribosomal protection gene (MIC above 8 μg ml(-1) ). Streptococci often harboured two or more tet determinants. As regards the resistance to aminoglycosides, staphylococci showed the lowest gentamicin and kanamycin median MIC along with streptomycin high level resistant (HLR) strains (MIC >1024 μg ml(-1) ) all harbouring str gene. The resistance determinant aac(6')-Ie-aph(2″)-Ia was present in few strains. Streptococci were basically nonsusceptible to aminoglycosides but neither HLR isolates nor resistance genes were detected. Enterococci revealed the highest MICs for gentamicin; two str harbouring isolates were shown to be HLR to streptomycin. Evidence was obtained for the circulation of antimicrobial-resistant strains and genes in sheep dairy farming. Tetracycline MIC of 64 μg ml(-1) and high-level resistance were detected for streptomycin (MIC >1024 μg ml(-1) ), so that effectiveness of common treatments may be at risk. © 2016 The Society for Applied Microbiology.
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Al-Tonbary, Youssef A; Soliman, Othman E; Sarhan, Mohammed M; Hegazi, Moustafa A; El-Ashry, Rasha A; El-Sharkawy, Ashraf A; Salama, Osama S; Yahya, Raida
2011-02-01
pediatric hematology/oncology patients are faced with an increased risk of nosocomial infections (NIs) that vary in different populations and different institutions with considerable morbidity and mortality. This study was undertaken to assess the frequency and patterns of NIs in 1564 pediatric patients and to determine the prevalence of causative organisms and their antimicrobial sensitivity. a retrospective analysis was made in the patients admitted between January 2007 and January 2008 to the pediatric hematoloy/oncology unit of Mansoura University, Egypt. The 1564 patients showed 2084 admissions and 27 092 inpatient days. The Centers for Disease Control and Prevention criteria were used as a standard definition for NI. the overall rate of NIs in all patients and neutropenic patients was 8.6 and 25.3 per 1000 patient-days respectively. The frequent sites of NIs were blood stream (42.7%), the respiratory system (25.3%), the urinary system (22.2%) and the central nervous system (9.8%), whereas nosocomial fever of unknown origin constituted 52.9% of cases. The incidence of NIs was significantly higher during neutropenic days (P<0.001). Gram-positive organisms represented 64.5% of pathogens (Staphylococci 71.5%, Streptococci 16%, and pneumococci 7%), and Gram-negative organisms represented 30% (E. coli 48.6%, Klebsiella 15.7%, Pseudomonas 35.7%, and C. albicans 5.5%). Positive cultures were more frequent in summer (July to September). Susceptibility of isolated organisms was relatively low (cefoperazone/sulbactam 49.9%, amikacin 35.9%, imipenem/cilastin 34.4%, cefoperazone 33.6%, and vancomycin 36.5%). Methicillin-resistant S. aureus, extended spectrum beta lactamase and vancomycin resistant enterococci represented 30%, 45% and 75% of isolated S. aureus, Gram-negative organisms and Enterococci, respectively. blood stream infection and fever of unknown origin are the most common nosocomial infections in pediatric hematology/oncology patients with a higher risk during neutropenic days. Isolated organisms are multi-drug resistant, predominantly Gram-positive pathogens with a high incidence of methicillin-resistant S. aureus, extended spectrum beta lactamase and vancomycin resistant enterococci organisms.
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Fulton, John W.; Koerkle, Edward H.; McCoy, Jamie L.; Zarr, Linda F.
2016-01-21
A total of 1,742 water samples were collected at 52 main-stem and tributary sites. Quantifiable concentrations of Escherichia coli (E. coli) were reported in 1,667 samples, or 97.0 percent of 1,719 samples; concentrations in 853 samples (49.6 percent) exceeded the U.S. Environmental Protection Agency (EPA) recreational water-quality criterion of 235 colonies per 100 milliliters (col/100 mL). Quantifiable concentrations of fecal coliform (FC) bacteria were reported in 1,693 samples, or 98.8 percent of 1,713 samples; concentrations in 780 samples (45.5 percent) exceeded the Commonwealth of Pennsylvania water contact criterion of 400 col/100 mL. Quantifiable concentrations of enterococci bacteria were reported in 912 samples, or 87.5 percent of 1,042 samples; concentrations in 483 samples (46.4 percent) exceeded the EPA recreational water-quality criterion of 61 col/100 mL. The median percentage of samples in which bacteria concentrations exceeded recreational water-quality standards across all sites with five or more samples was 48 for E. coli, 43 for FC, and 75 for enterococci. E. coli, FC, and enterococci concentrations at main-stem sites had significant positive correlations with streamflow under all weather conditions, with rho values ranging from 0.203 to 0.598. Seasonal Kendall and logistic regression were evaluated to determine whether statistically significant trends were present during the period 2001–09. In general, Seasonal Kendall tests for trends in E. coli and FC bacteria were inconclusive. Results of logistic regression showed no significant trends in dry-weather exceedance of the standards; however, significant decreases in the likelihood that wet-weather E. coli and FC bacteria concentrations will exceed EPA recreational standards were found at the USGS streamgaging station Allegheny River at 9th Street Bridge. Nonparametric correlation analysis, including Spearman’s rho and the paired Prentice-Wilcoxon test, was used to screen for associations among fecal indicator bacteria concentrations and the field characteristics streamflow, water temperature, pH, specific conductance, dissolved-oxygen concentration, and turbidity.
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Coque, Teresa M.; Singh, Kavindra V.; Weinstock, George M.; Murray, Barbara E.
1999-01-01
Enterococci are usually susceptible in vitro to trimethoprim; however, high-level resistance (HLR) (MICs, >1,024 μg/ml) has been reported. We studied Enterococcus faecalis DEL, for which the trimethoprim MIC was >1,024 μg/ml. No transfer of resistance was achieved by broth or filter matings. Two different genes that conferred trimethoprim resistance when they were cloned in Escherichia coli (MICs, 128 and >1,024 μg/ml) were studied. One gene that coded for a polypeptide of 165 amino acids (MIC, 128 μg/ml for E. coli) was identical to dfr homologs that we cloned from a trimethoprim-susceptible E. faecalis strain, and it is presumed to be the intrinsic E. faecalis dfr gene (which causes resistance in E. coli when cloned in multiple copies); this gene was designated dfrE. The nucleotide sequence 5′ to this dfr gene showed similarity to thymidylate synthetase genes, suggesting that the dfr and thy genes from E. faecalis are located in tandem. The E. faecalis gene that conferred HLR to trimethoprim in E. coli, designated dfrF, codes for a predicted polypeptide of 165 amino acids with 38 to 64% similarity with other dihydrofolate reductases from gram-positive and gram-negative organisms. The nucleotide sequence 5′ to dfrF did not show similarity to the thy sequences. A DNA probe for dfrF hybridized under high-stringency conditions only to colony lysates of enterococci for which the trimethoprim MIC was >1,024 μg/ml; there was no hybridization to plasmid DNA from the strain of origin. To confirm that this gene causes trimethoprim resistance in enterococci, we cloned it into the integrative vector pAT113 and electroporated it into RH110 (E. faecalis OG1RF::Tn916ΔEm) (trimethoprim MIC, 0.5 μg/ml), which resulted in RH110 derivatives for which the trimethoprim MIC was >1,024 μg/ml. These results indicate that dfrF is an acquired but probably chromosomally located gene which is responsible for in vitro HLR to trimethoprim in E. faecalis. PMID:9869579
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Heaney, Christopher D; Exum, Natalie G; Dufour, Alfred P; Brenner, Kristen P; Haugland, Richard A; Chern, Eunice; Schwab, Kellogg J; Love, David C; Serre, Marc L; Noble, Rachel; Wade, Timothy J
2014-11-01
Recent studies showing an association between fecal indicator organisms (FIOs) in sand and gastrointestinal (GI) illness among beachgoers with sand contact have important public health implications because of the large numbers of people who recreate at beaches and engage in sand contact activities. Yet, factors that influence fecal pollution in beach sand remain unclear. During the 2007 National Epidemiological and Environmental Assessment of Recreational (NEEAR) Water Study, sand samples were collected at three locations (60 m apart) on weekend days (Sat, Sun) and holidays between June and September at two marine beaches - Fairhope Beach, AL and Goddard Beach, RI - with nearby publicly-owned treatment works (POTWs) outfalls. F(+) coliphage, enterococci, Bacteroidales, fecal Bacteroides spp., and Clostridium spp. were measured in sand using culture and qPCR-based calibrator-cell equivalent methods. Water samples were also collected on the same days, times and transects as the 144 sand samples and were assayed using the same FIO measurements. Weather and environmental data were collected at the time of sample collection. Mean FIO concentrations in sand varied over time, but not space. Enterococci CFU and CCE densities in sand were not correlated, although other FIOs in sand were. The strongest correlation between FIO density in sand and water was fecal Bacteroides CCE, followed by enterococci CFU, Clostridium spp. CCE, and Bacteroidales CCE. Overall, the factors associated with FIO concentrations in sand were related to the sand-water interface (i.e., sand-wetting) and included daily average densities of FIOs in water, rainfall, and wave height. Targeted monitoring that focuses on daily trends of sand FIO variability, combined with information about specific water quality, weather, and environmental factors may inform beach monitoring and management decisions to reduce microbial burdens in beach sand. The views expressed in this paper are those of the authors and do not necessarily reflect the views or policies of the U.S. Environmental Protection Agency. Copyright © 2014 Elsevier B.V. All rights reserved.