Methicillin resistant Staphylococcus aureus in Ethiopia: a meta-analysis.

PubMed

Eshetie, Setegn; Tarekegn, Fentahun; Moges, Feleke; Amsalu, Anteneh; Birhan, Wubet; Huruy, Kahsay

2016-11-21

The burden of methicillin resistant Staphylococcus aureus is a major public health concern worldwide; however the overall epidemiology of multidrug resistant strains is neither coordinated nor harmonized, particularly in developing countries including Ethiopia. Therefore, the aim of this meta-analysis was to assess the burden of methicillin resistant Staphylococcos aureus and its antibiotic resistance pattern in Ethiopia at large. PubMed, Google Scholar, and lancet databases were searched and a total of 20 studies have been selected for meta-analysis. Six authors have independently extracts data on the prevalence of methicillin resistant Staphylococcus aureus among clinical isolates of Staphylococcus aureus. Statistical analysis was achieved by using Open meta-analyst (version 3.13) and Comprehensive meta-analysis (version 3.3) softwares. The overall prevalence of methicillin resistant Staphylococcus aureus and its antibiotic resistance pattern were pooled by using the forest plot, table and figure with 95% CI. The pooled prevalence of methicillin resistant Staphylococcus aureus was 32.5% (95% CI, 24.1 to 40.9%). Moreover, methicillin resistant Staphylococcus aureus strains were found to be highly resistant to penicillin, ampicillin, erythromycin, and amoxicillin, with a pooled resistance ratio of 99.1, 98.1, 97.2 and 97.1%, respectively. On the other hand, comparably low levels of resistance ratio were noted to vancomycin, 5.3%. The overall burden of methicillin resistant Staphylococcus aureus is considerably high, besides these strains showed extreme resistance to penicillin, ampicillin, erythromycin and amoxicillin. In principle, appropriate use of antibiotics, applying safety precautions are the key to reduce the spread of multidrug resistant strains, methicillin resistant Staphylococcus aureus in particular.

Factors Affecting the Persistence of Staphylococcus aureus on Fabrics

PubMed Central

Wilkoff, Lee J.; Westbrook, Louise; Dixon, Glen J.

1969-01-01

The persistence of Staphylococcus aureus (Smith) on wool blanket, wool gabardine, cotton sheeting, cotton knit jersey, cotton terry cloth, and cotton wash-and-wear fabrics was studied. The fabrics were exposed to bacterial populations by three methods: direct contact, aerosol, and a lyophilized mixture of bacteria and dust having a high content of textile fibers. The contaminated fabrics were held in 35 or 78% relative humidities at 25 C. In general, the persistence time of S. aureus populations on fabrics held in 35% relative humidity was substantially longer when the fabrics were contaminated by exposure to aerosolized cultures or to dust containing bacteria than when contaminated by direct contact. In a 78% relative humidity, bacterial populations on the fabrics persisted for substantially shorter periods of time regardless of the mode of contamination or fabric type. Cotton wash-and-wear fabric (treated with a modified triazone resin) was the material on which populations of S. aureus persisted for the shortest time. This organism retained its virulence for Swiss mice after being recovered from wool gabardine swatches held 4 weeks in 35% relative humidity and 6 weeks in 78% relative humidity. Images PMID:5775911

A thin layer electrochemical cell for disinfection of water contaminated with Staphylococcus aureus

PubMed Central

Gusmão, Isabel C. P.; Moraes, Peterson B.; Bidoia, Ederio D.

2009-01-01

A thin layer electrochemical cell was tested and developed for disinfection treatment of water artificially contaminated with Staphylococcus aureus. Electrolysis was performed with a low-voltage DC power source applying current densities of 75 mA cm-2 (3 A) or 25 mA cm-2 (1 A). A dimensionally stable anode (DSA) of titanium coated with an oxide layer of 70%TiO2 plus 30%RuO2 (w/w) and a 3 mm from a stainless-steel 304 cathode was used in the thin layer cell. The experiments were carried out using a bacteria suspension containing 0.08 M sodium sulphate with chloride-free to determine the bacterial inactivation efficacy of the thin layer cell without the generation of chlorine. The chlorine can promote the formation of trihalomethanes (THM) that are carcinogenic. S. aureus inactivation increased with electrolysis time and lower flow rate. The flow rates used were 200 or 500 L h-1. At 500 L h-1 and 75 mA cm-2 the inactivation after 60 min was about three logs of decreasing for colony forming units by mL. However, 100% inactivation for S. aureus was observed at 5.6 V and 75 mA cm-2 after 30 min. Thus, significant disinfection levels can be achieved without adding oxidant substances or generation of chlorine in the water. PMID:24031410

Staphylococcus aureus and Community-Associated Methicillin-Resistant Staphylococcus aureus (CA-MRSA) in and Around Therapeutic Whirlpools in College Athletic Training Rooms

PubMed Central

Kahanov, Leamor; Kim, Young Kyun; Eberman, Lindsey; Dannelly, Kathleen; Kaur, Haninder; Ramalinga, A.

2015-01-01

Context: Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has become a leading cause of skin and soft tissue infection in the nonhospitalized community. Care of the athletes in athletic training rooms is specifically designed with equipment tailored to the health care needs of the athletes, yet recent studies indicate that CA-MRSA is still prevalent in athletic facilities and that cleaning methods may not be optimal. Objective: To investigate the prevalence of Staphylococcus aureus and CA-MRSA in and around whirlpools in the athletic training room. Design: Cross-sectional study. Setting: National Collegiate Athletic Association Division I university. Patients or Other Participants: Student-athletes (n = 109) consisting of 46 men (42%) and 63 women (58%) representing 6 sports. Main Outcome Measure(s): Presence of MRSA and Staphylococcus aureus in and around the whirlpool structures relative to sport and number of athletes using the whirlpools. Results: We identified Staphylococcus aureus in 22% (n = 52/240) of the samples and MRSA in 0.8% (n = 2/240). A statistically significant difference existed between the number of athletes using the whirlpool and the presence of Staphylococcus aureus in and around the whirlpools (F2,238 = 2.445, P = .007). However, Staphylococcus aureus was identified regardless of whether multiple athletes used a whirlpool or no athletes used a whirlpool. We did not identify a relationship between the number of athletes who used a whirlpool and Staphylococcus aureus or MRSA density (P = .134). Conclusions: Staphylococcus aureus and MRSA were identified in and around the whirlpools. Transmission of the bacteria can be reduced by following the cleaning and disinfecting protocols recommended by the Centers for Disease Control and Prevention. Athletic trainers should use disinfectants registered by the Environmental Protection Agency to sanitize all whirlpools between uses. PMID:25710853

Communications of Staphylococcus aureus and non-aureus Staphylococcus species from bovine intramammary infections and teat apex colonization.

PubMed

Mahmmod, Yasser S; Klaas, Ilka Christine; Svennesen, Line; Pedersen, Karl; Ingmer, Hanne

2018-05-16

The role of non-aureus staphylococci (NAS) in the risk of acquisition of intramammary infections with Staphylococcus aureus is vague and still under debate. The objectives of this study were to (1) investigate the distribution patterns of NAS species from milk and teat skin in dairy herds with automatic milking systems, and (2) examine if the isolated NAS influences the expression of S. aureus virulence factors controlled by the accessory gene regulator (agr) quorum sensing system. In 8 herds, 14 to 20 cows with elevated somatic cell count were randomly selected for teat skin swabbing and aseptic quarter foremilk samples from right hind and left front quarters. Teat skin swabs were collected using the modified wet-dry method and milk samples were taken aseptically for bacterial culture. Colonies from quarters with suspicion of having NAS in milk or teat skin samples (or both) were subjected to MALDI-TOF assay for species identification. To investigate the interaction between S. aureus and NAS, 81 isolates NAS were subjected to a qualitative β-galactosidase reporter plate assay. In total, 373 NAS isolates were identified representing 105 from milk and 268 from teat skin of 284 quarters (= 142 cows). Sixteen different NAS species were identified, 15 species from teat skin and 10 species from milk. The most prevalent NAS species identified from milk were Staphylococcus epidermidis (50%), Staphylococcus haemolyticus (15%), and Staphylococcus chromogenes (11%), accounting for 76%. Meanwhile, the most prevalent NAS species from teat skin were Staphylococcus equorum (43%), S. haemolyticus (16%), and Staphylococcus cohnii (14%), accounting for 73%. Using reporter gene fusions monitoring transcriptional activity of key virulence factors and regulators, we found that out of 81 supernatants of NAS isolates, 77% reduced expression of hla, encoding a-hemolysin, 70% reduced expression of RNAIII, the key effector molecule of agr, and 61% reduced expression of spa encoding

Comparative genomic analysis of the genus Staphylococcus including Staphylococcus aureus and its newly described sister species Staphylococcus simiae

PubMed Central

2012-01-01

Background Staphylococcus belongs to the Gram-positive low G + C content group of the Firmicutes division of bacteria. Staphylococcus aureus is an important human and veterinary pathogen that causes a broad spectrum of diseases, and has developed important multidrug resistant forms such as methicillin-resistant S. aureus (MRSA). Staphylococcus simiae was isolated from South American squirrel monkeys in 2000, and is a coagulase-negative bacterium, closely related, and possibly the sister group, to S. aureus. Comparative genomic analyses of closely related bacteria with different phenotypes can provide information relevant to understanding adaptation to host environment and mechanisms of pathogenicity. Results We determined a Roche/454 draft genome sequence for S. simiae and included it in comparative genomic analyses with 11 other Staphylococcus species including S. aureus. A genome based phylogeny of the genus confirms that S. simiae is the sister group to S. aureus and indicates that the most basal Staphylococcus lineage is Staphylococcus pseudintermedius, followed by Staphylococcus carnosus. Given the primary niche of these two latter taxa, compared to the other species in the genus, this phylogeny suggests that human adaptation evolved after the split of S. carnosus. The two coagulase-positive species (S. aureus and S. pseudintermedius) are not phylogenetically closest but share many virulence factors exclusively, suggesting that these genes were acquired by horizontal transfer. Enrichment in genes related to mobile elements such as prophage in S. aureus relative to S. simiae suggests that pathogenesis in the S. aureus group has developed by gene gain through horizontal transfer, after the split of S. aureus and S. simiae from their common ancestor. Conclusions Comparative genomic analyses across 12 Staphylococcus species provide hypotheses about lineages in which human adaptation has taken place and contributions of horizontal transfer in pathogenesis. PMID

Methicillin-resistant Staphylococcus aureus in palliative care: A prospective study of Methicillin-resistant Staphylococcus aureus prevalence in a hospital-based palliative care unit.

PubMed

Schmalz, Oliver; Strapatsas, Tobias; Alefelder, Christof; Grebe, Scott Oliver

2016-07-01

Methicillin-resistant Staphylococcus aureus is a common organism in hospitals worldwide and is associated with morbidity and mortality. However, little is known about the prevalence in palliative care patients. Furthermore, there is no standardized screening protocol or treatment for patients for whom therapy concentrates on symptom control. Examining the prevalence of methicillin-resistant Staphylococcus aureus in palliative care patients as well as the level of morbidity and mortality. We performed a prospective study where methicillin-resistant Staphylococcus aureus screening was undertaken in 296 consecutive patients within 48 h after admission to our palliative care unit. Medical history was taken, clinical examination was performed, and the Karnofsky Performance Scale and Palliative Prognostic Score were determined. Prevalence of Methicillin-resistant Staphylococcus aureus was compared to data of general hospital patients. In total, 281 patients were included in the study having a mean age of 69.7 years (standard deviation = 12.9 years) and an average Karnofsky Performance Scale between 30% and 40%. The mean length of stay was 9.7 days (standard deviation = 7.6 days). A total of 24 patients were methicillin-resistant Staphylococcus aureus positive on the first swab. Median number of swabs was 2. All patients with a negative methicillin-resistant Staphylococcus aureus swab upon admission remained Methicillin-resistant Staphylococcus aureus negative in all subsequent swabs. Our study suggests that the prevalence of Methicillin-resistant Staphylococcus aureus among patients in an in-hospital palliative care unit is much higher than in other patient populations. © The Author(s) 2016.

Photodynamic inactivation of contaminated blood with Staphylococcus aureus

NASA Astrophysics Data System (ADS)

Corrêa, Thaila Q.; Inada, Natalia M.; Pratavieira, Sebastião.; Blanco, Kate C.; Kurachi, Cristina; Bagnato, Vanderlei S.

2016-03-01

The presence of bacteria in the bloodstream can trigger a serious systemic inflammation and lead to sepsis that cause septic shock and death. Studies have shown an increase in the incidence of sepsis over the years and it is mainly due to the increased resistance of microorganisms to antibiotics, since these drugs are still sold and used improperly. The bacterial contamination of blood is also a risk to blood transfusions. Thus, bacteria inactivation in blood is being studied in order to increase the security of the blood supply. The purpose of this study was to decontaminate the blood using the photodynamic inactivation (PDI). Human blood samples in the presence of Photogem® were illuminated at an intensity of 30 mW/cm2, and light doses of 10 and 15 J/cm2. Blood counts were carried out for the quantitative evaluation and blood smears were prepared for qualitative and morphological evaluation by microscopy. The results showed normal viability values for the blood cells analyzed. The light doses showed minimal morphological changes in the membrane of red blood cells, but the irradiation in the presence of the photosensitizer caused hemolysis in red blood cells at the higher concentrations of the photosensitizer. Experiments with Staphylococcus aureus, one of the responsible of sepsis, showed 7 logs10 of photodynamic inactivation with 50 μg/mL and 15 J/cm2 and 1 log10 of this microorganism in a co-culture with blood.

Prevalence and antibiogram study of Salmonella and Staphylococcus aureus in poultry meat

PubMed Central

Akbar, Ali; Anal, Anil Kumar

2013-01-01

Objective To evaluate the presence and antibiogram pattern of Salmonella and Staphylococcus aureus (S. aureus) in retail poultry meat products. Methods Foodborne pathogens (Salmonella and S. aureus) were isolated from poultry meat and confirmed with the help of biochemical and immunological test. Antibiogram of the isolates were examined by following CLSI methods. Results A total number of 209 poultry meat samples were collected and studied in this study. Out of which, 5.26% were found contaminated with Salmonella while 18.18% were found contaminated with S. aureus. All the Salmonella and S. aureus isolates were found resistant to at least one antibiotic. About 72.72% of the Salmonella isolates showed resistance to tetracycline, while S. aureus isolates were also found highly resistant to tetracycline equal to 44.73%. One of the Salmonella isolates showed multi-drug resistance to almost six antibiotics out of nine antibiotics used in the study. Multidrug resistant S. aureus isolates were also found in the study. Conclusions The study confirmed the presence of Salmonella and S. aureus in retail poultry meat. It is a potential threat to consumer health. To reduce the risk of contamination, good hygiene practices are necessary from processing to storage. PMID:23593598

Characterization of Staphylococcus aureus Isolated from Food Products in Western Algeria.

PubMed

Chaalal, Wafaa; Chaalal, Nadia; Bourafa, Nadjette; Kihal, Mebrouk; Diene, Seydina M; Rolain, Jean-Marc

2018-03-15

The current study aimed to characterize Staphylococcus aureus isolates from foodstuffs collected from western Algeria. A total of 153 S. aureus isolates from various raw and processed foods were obtained and identified using matrix-assisted laser desorption and ionization time-of-flight mass spectrometry. Isolates were characterized by antimicrobial susceptibility testing and toxin gene detection. Methicillin-resistant Staphylococcus aureus (MRSA) isolates were identified by detection of the mecA gene and characterized by staphylococcal cassette chromosome mec (SCCmec) typing. We found that 30.9% (153/495) of food samples were contaminated with S. aureus. Thirty-three (21.5%) S. aureus isolates were identified as MRSA, and 16.9% (26/153) carried the mecA gene. Three SCCmec types were identified of which type IV was the most common (69.2%) followed by type V (15.3%) and type II (7.6%). Two MRSA isolates were not typable with SCCmec typing. None of the examined isolates harbored mecC. Furthermore, 14.3% (22/153) of the isolates were toxigenic S. aureus. The cytotoxin gene pvl was detected in 11.1% of the S. aureus isolates. This gene was more commonly detected (76.4%) in MRSA isolates than in methicillin-suceptible Staphylococcus aureus (MSSA) isolates. The tsst-1 gene coding for toxic shock syndrome toxin was isolated rarely (3.2%) and only in MSSA isolates. According to disk diffusion test results, 70 isolates were resistant to only one antimicrobial drug, and 51 (33.3%) isolates were multidrug resistant. Other 32 isolates were susceptible to all antibiotics. Our study highlights, for the first time, a high prevalence of multidrug-resistant S. aureus isolates carrying pvl or tsst-1 found in food products in Algeria. The risk of MRSA transmission through the food chain cannot be disregarded, particularly in uncooked foods.

Bacteriophage Transduction in Staphylococcus aureus.

PubMed

Olson, Michael E

2016-01-01

The genetic manipulation of Staphylococcus aureus for molecular experimentation is a valuable tool for assessing gene function and virulence. Genetic variability between strains coupled with difficult laboratory techniques for strain construction is a frequent roadblock in S. aureus research. Bacteriophage transduction greatly increases the speed and ease of S. aureus studies by allowing movement of chromosomal markers and plasmids between strains. This technique enables the S. aureus research community to focus investigations on clinically relevant isolates.

Sustainable reduction of nasal colonization and hand contamination with Staphylococcus aureus in food handlers, 2002-2011.

PubMed

Ho, J; Boost, M; O'Donoghue, M

2015-06-01

A longitudinal study of nasal colonization and hand contamination of food handlers with Staphylococcus aureus commenced in 2002 prior to the outbreak of severe acute respiratory syndrome. In the follow-up in 2003 when hygiene measures were strictly implemented, significant reductions in carriage were observed. To investigate if this change was sustained, nasal and hand carriage rates were compared between the earlier studies and a further sampling in 2011. The initial nasal carriage rate was 35% and hand contamination 41·2%, decreasing to 23·5% and 11·6%, respectively in 2003 (P < 0·001). In 2011, nasal carriage was similar to 2003 (22·9%), while hand contamination dropped further to 3·7% (P < 0·001). Spa-typing revealed 39 types in 2002 and 42 in 2011. This study reveals that the marked reduction in colonization had been sustained. This may be attributed to reduced opportunities for spread due to enhanced hygiene and reinforces its importance for control of disease.

Failure of bacterial screening to detect Staphylococcus aureus: the English experience of donor follow-up.

PubMed

Brailsford, S R; Tossell, J; Morrison, R; McDonald, C P; Pitt, T L

2018-05-24

Between February 2011 and December 2016, over 1·6 million platelet units, 36% pooled platelets, underwent bacterial screening prior to issue. Contamination rates for apheresis and pooled platelets were 0·02% and 0·07%, respectively. Staphylococcus aureus accounted for 21 contaminations, including four pooled platelets, one confirmed transfusion-transmitted infection (TTI) and three 'near-miss' incidents detected on visual inspection which were negative on screening. We describe follow-up investigations of 16 donors for skin carriage of S. aureus and molecular characterisation of donor and pack isolates. Units were screened by the BacT/ALERT 3D detection system. Contributing donors were interviewed and consent requested for skin and nasal swabbing. S. aureus isolates were referred for spa gene type and DNA macrorestriction profile to determine identity between carriage strains and packs. Donors of 10 apheresis and two pooled packs screen positive for S. aureus were confirmed as the source of contamination; seven had a history of skin conditions, predominantly eczema; 11 were nasal carriers. The 'near-miss' incidents were associated with apheresis donors, two donors harboured strains indistinguishable from the pack strain. The TTI was due to a screen-negative pooled unit, and a nasal isolate of one donor was indistinguishable from that in the unit. Staphylococcus aureus contamination is rare but potentially harmful in platelet units. Donor isolates showed almost universal correspondence in molecular type with pack isolates, thus confirming the source of contamination. The importance of visual inspection of packs prior to transfusion is underlined by the 'near-miss' incidents. © 2018 International Society of Blood Transfusion.

Methicillin-resistant Staphylococcus aureus: a controversial food-borne pathogen.

PubMed

Sergelidis, D; Angelidis, A S

2017-06-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of severe healthcare-associated (HA) infections. Although during the last decade the incidence of HA invasive infections has dropped, the incidence of community-associated MRSA (CA-MRSA) infections has risen among the general population. Moreover, CA-MRSA, livestock-associated MRSA (LA-MRSA) and HA-MRSA (HA-MRSA) can be found in foods intended for human consumption. Several studies from different geographical areas have reported the presence of enterotoxin genes in several MRSA food isolates. Molecular typing studies have revealed genetic relatedness of these enterotoxigenic isolates with isolates incriminated in human infections. The contamination sources for foods, especially animal-origin foods, may be livestock as well as humans involved in animal husbandry and food-processing. Under favourable environmental conditions for growth and enterotoxin production, enterotoxigenic S. aureus isolates present in foods can cause staphylococcal food poisoning (SFP), irrespective of the contamination origin. Owing to the typically moderate clinical manifestations of SFP, the S. aureus strains responsible for SFP (cases or outbreaks) are frequently either not identified or not further characterized. Antimicrobial susceptibility testing is rarely performed, because administration of antimicrobial therapy is not required in the vast majority of cases. Staphylococcal food poisoning is the result of consumption of foods with preformed enterotoxins. Hence, similar to methicillin-sensitive enterotoxigenic S. aureus, enterotoxigenic MRSA can also act as food-borne pathogens upon favourable conditions for growth and enterotoxin production. The severity of the intoxication is not related to the antimicrobial resistance profile of the causative S. aureus strain and therefore MRSA food-borne outbreaks are not expected to be more severe. This review evaluates the potential of methicillin-resistant Staphylococcus

[Vancomycin-resistant Staphylococcus aureus].

PubMed

Rodríguez, Carlos Andrés; Vesga, Omar

2005-12-01

The evolution and molecular mechanisms of vancomycin resistance in Staphylococcus aureus were reviewed. Case reports and research studies on biochemestry, electron microscopy and molecular biology of Staphylococcus aureus were selected from Medline database and summarized in the following review. After almost 40 years of successful treatment of S. aureus with vancomycin, several cases of clinical failures have been reported (since 1997). S. aureus strains have appeared with intermediate susceptibility (MIC 8-16 microg/ml), as well as strains with heterogeneous resistance (global MIC < or =4 microg/ml), but with subpopulations of intermediate susceptibility. In these cases, resistance is mediated by cell wall thickening with reduced cross linking. This traps the antibiotic before it reaches its major target, the murein monomers in the cell membrane. In 2002, a total vancomycin resistant strain (MIC > or =32 microg/ml) was reported with vanA genes from Enterococcus spp. These genes induce the change of D-Ala-D-Ala terminus for D-Ala-D-lactate in the cell wall precursors, leading to loss of affinity for glycopeptides. Vancomycin resistance in S. aureus has appeared; it is mediated by cell wall modifications that trap the antibiotic before it reaches its action site. In strains with total resistance, Enterococcus spp. genes have been acquired that lead to modification of the glycopeptide target.

Staphylococcus aureus recovery from cotton towels.

PubMed

Oller, Anna R; Mitchell, Ashley

2009-04-30

Staphylococcus aureus is an emerging pathogen afflicting healthy individuals without known risk factors, and methicillin-resistant Staphylococcus aureus has been shown to colonize multiple family members sharing households. Because household items such as towels are often shared by family members, this study investigated whether cotton towel absorbency or washing conditions affect Staphylococcus aureus cell viability or cell retention, and whether the levels may be sufficient for person-to-person transmission. Staphylococcus aureus ATCC 25923 was added to a 48 mm(2) template area on three cotton towel types (terry, pima, and Egyptian), and subjected to hand washing, without manual wringing, in three conditions (water only, bleach addition, or liquid detergent addition). Serial dilutions plated onto mannitol salt plates quantified bacteria for inoculations, pre- and post-wash water samples, towel surfaces, and hand transfer. Hand transfer of bacteria was determined on towels immediately, one, 24, and 48 hours post inoculation. Bleach (p < or = .05) was the most effective at reducing bacterial viability on all towel types compared to detergent and water. Although not statistically significant, more Staphylococcus colonies were recovered from higher absorbency towels and from inside directly inoculated template areas. A paired t-test showed a difference between immediate and one-hour CFUs versus 24- and 48-hour recoveries (0.0002) for hand transfers. Cell viability decreased for over 48 hours on towels, but sufficient quantities may remain for colonization. More absorbent towels may harbor more Staphylococci than less absorbent ones, and may serve as a transmission mechanism for the bacterium.

Threat of drug resistant Staphylococcus aureus to health in Nepal

PubMed Central

2014-01-01

Background Staphylococcus aureus is the most commonly isolated organism from the different clinical samples in hospital. The emergence and dissemination of methicillin resistant Staphylococcus aureus (MRSA) and growing resistance to non-beta-lactam antibiotics is making treatment of infections due to this organism increasingly difficult. Methods This study was conducted to determine the frequency of Staphylococcus aureus isolated from different clinical samples, rates of MRSA and full antibiotic susceptibility profiles. Clinical samples were cultured and Staphylococcus aureus was identified using standard microbiological methods recommended by the American Society for Microbiology (ASM). Methicillin resistance was confirmed using cefoxitin and oxacillin disks. Inducible clindamycin resistance was identified using D-zone test. Results From the processed samples, 306 isolates of Staphylococcus aureus were recovered. All the isolates were susceptible to vancomycin and teicoplanin. Methicillin resistance was observed in 43.1% of isolates while inducible clindamycin resistance in 12.4% of the isolates. Conclusions The results of our study reveals that rates of resistance to commonly prescribed antibiotics in Staphylococcus aureus clinical isolates is high. In particular, rate of methicillin resistance is alarming, prompting concern on the rational use of antibiotics and vigilant laboratory-based surveillance of resistance rates in Nepal. PMID:24655316

Staphylococcus lugdunensis, a serious pathogen in periprosthetic joint infections: comparison to Staphylococcus aureus and Staphylococcus epidermidis.

PubMed

Lourtet-Hascoët, J; Bicart-See, A; Félicé, M P; Giordano, G; Bonnet, E

2016-10-01

The aim of this study was to assess the characteristics of periprosthetic joint infection (PJI) due to Staphylococcus lugdunensis and to compare these to the characteristics of PJI due to Staphylococcus aureus and Staphylococcus epidermidis. A retrospective multicentre study including all consecutive cases of S. lugdunensis PJI (2000-2014) was performed. Eighty-eight cases of staphylococcal PJI were recorded: 28 due to S. lugdunensis, 30 to S. aureus, and 30 to S. epidermidis, as identified by Vitek 2 or API Staph (bioMérieux). Clinical symptoms were more often reported in the S. lugdunensis group, and the median delay between surgery and infection was shorter for the S. lugdunensis group than for the S. aureus and S. epidermidis groups. Regarding antibiotic susceptibility, the S. lugdunensis strains were susceptible to antibiotics and 61% of the patients could be treated with levofloxacin + rifampicin. The outcome of the PJI was favourable for 89% of patients with S. lugdunensis, 83% with S. aureus, and 97% with S. epidermidis. S. lugdunensis is an emerging pathogen with a pathogenicity quite similar to that of S. aureus. This coagulase-negative Staphylococcus must be identified precisely in PJI, in order to select the appropriate surgical treatment and antibiotics . Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Frequency of methicillin-resistant Staphylococcus aureus nasal colonization among patients suffering from methicillin resistant Staphylococcus aureus bacteraemia.

PubMed

Aslam, Nadia; Izhar, Mateen; Mehdi, Naima

2013-11-01

To determine rate of nasal colonization in Patients suffering from bacteraemia caused by methicillin resistant Staphylococcus aureus. This descriptive cross sectional study was carried out in a tertiary ca re, University Teaching Hospital (Shaikh Zayed Hospital, Lahore) from October 2010 to August 2011. Nasal swabs were taken from patients suffering from MRSA bacteraemia and were plated on mannitol salt agar plates to isolate Staphylococcus aureus (S. aureus) which were then tested for oxacillin susceptibility. Nasal colonization was present in 52.5% of patients suffering from MRSA bacteraemia. Nasal colonization rates with MRSA were high among patients suffering from MRSA bacteraemia especially in those undergoing dialysis or surgical procedures. Therefore, screening and nasal decolonization should be practiced in hospitals.

Prevalence of Staphylococcus aureus and methicillin resistant Staphylococcus aureus (MRSA) in the oral cavity.

PubMed

Koukos, Georgios; Sakellari, Dimitra; Arsenakis, Minas; Tsalikis, Lazaros; Slini, Theodora; Konstantinidis, Antonios

2015-09-01

To assess the prevalence of Staphylococcus aureus and methicillin resistant Staphylococcus aureus (MRSA) in plaque and tongue samples from systemically healthy subjects with periodontal health, gingivitis or chronic periodontitis. After screening 720 potentially eligible subjects, 154 systemically healthy participants were ultimately enrolled in the current study. Subgingival samples were taken from the first molars and the tongue and analyzed for the presence of S. aureus and MRSA by polymerase chain reaction (PCR), using primers and conditions previously described in the literature. In addition, samples were taken from deep periodontal pockets of chronic periodontitis patients. Statistical analysis was performed by applying non-parametric tests (Kruskal-Wallis for clinical parameters, and z-test with Bonferroni corrections for distributions of assessed parameters). All comparisons were set at the 0.05 significance level. S. aureus was detected in 18% of all participants and in 10% of the samples tested. No significant differences were found in its distribution among the three investigated groups (z-test for proportions with Bonferroni corrections, p>0.05). The mecA gene was not present in any of the S. aureus found. S. aureus can be found in the oral environment regardless of the periodontal conditions and therefore should be considered as a member of the transient flora not participating in periodontal pathology. Subgingival sites and tongue surfaces seem to be an unusual habitat of MRSA. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Study of methicillin-resistant Staphylococcus aureus colonization among intermediate-care facility patients].

PubMed

Giret, P; Roblot, F; Poupet, J Y; Thomas, P; Lussier-Bonneau, M D; Pradère, C; Becq-Giraudon, B; Fauchère, J L; Castel, O

2001-08-01

Prevalence of methicillin-resistant Staphylococcus aureus is high in the Poitiers teaching hospital, particularly in the intermediate care facilities. We performed a survey of methicillin-resistant Staphylococcus aureus colonization in the intermediate care facilities and 265 patients were included. Nasal, cutaneous and wound swab cultures were done at the time of admission and at the time of the patients' departure. A decolonization procedure of methicillin-resistant Staphylococcus aureus carriers was performed using nasal application of fusidic acid and different soaps for the skin. At entry, 17.7% of patients were methicillin-resistant Staphylococcus aureus carriers (of at least one location). At departure, 30.4% were methicillin-resistant Staphylococcus aureus carriers. Among methicillin-resistant Staphylococcus aureus non-carriers at entry, 24.3% became methicillin-resistant Staphylococcus aureus carriers. The principal risk factor of carriage was the initial presence of a wound (RR = 3.6). The incidence rate of methicillin-resistant Staphylococcus aureus infection among the 265 patients included was 3%. The systematic screening of patients at the time of admission is expensive and isolation technically hard to manage in the intermediate care facilities. The risk factor we found in this study allow us to propose a 'light' screening limited to patients with wounds.

Presence of Laminin Receptors in Staphylococcus aureus

NASA Astrophysics Data System (ADS)

Lopes, J. D.; Dos Reis, M.; Brentani, R. R.

1985-07-01

A characteristic feature of infection by Staphylococcus aureus is bloodstream invasion and widespread metastatic abscess formation. The ability to extravasate, which entails crossing the vascular basement membrane, appears to be critical for the organism's pathogenicity. Extravasation by normal and neoplastic mammalian cells has been correlated with the presence of specific cell surface receptors for the basement membrane glycoprotein laminin. Similar laminin receptors were found in Staphylococcus aureus but not in Staphylococcus epidermidis, a noninvasive pathogen. There were about 100 binding sites per cell, with an apparent binding affinity of 2.9 nanomolar. The molecular weight of the receptor was 50,000 and pI was 4.2. Eukaryotic laminin receptors were visualized by means of the binding of S. aureus in the presence of laminin. Prokaryotic and eukaryotic invasive cells might utilize similar, if not identical, mechanisms for invasion.

Frequency of methicillin-resistant Staphylococcus aureus nasal colonization among patients suffering from methicillin resistant Staphylococcus aureus bacteraemia

PubMed Central

Aslam, Nadia; Izhar, Mateen; Mehdi, Naima

2013-01-01

Objective: To determine rate of nasal colonization in Patients suffering from bacteraemia caused by methicillin resistant Staphylococcus aureus. Methods: This descriptive cross sectional study was carried out in a tertiary ca re, University Teaching Hospital (Shaikh Zayed Hospital, Lahore) from October 2010 to August 2011. Nasal swabs were taken from patients suffering from MRSA bacteraemia and were plated on mannitol salt agar plates to isolate Staphylococcus aureus (S. aureus) which were then tested for oxacillin susceptibility. Results: Nasal colonization was present in 52.5% of patients suffering from MRSA bacteraemia. Conclusion: Nasal colonization rates with MRSA were high among patients suffering from MRSA bacteraemia especially in those undergoing dialysis or surgical procedures. Therefore, screening and nasal decolonization should be practiced in hospitals. PMID:24550968

Prevalence of Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus in Retail Ready-to-Eat Foods in China

PubMed Central

Yang, Xiaojuan; Zhang, Jumei; Yu, Shubo; Wu, Qingping; Guo, Weipeng; Huang, Jiahui; Cai, Shuzhen

2016-01-01

Staphylococcus aureus, particularly methicillin-resistant S.aureus (MRSA), is a life-threatening pathogen in humans, and its presence in food is a public health concern. MRSA has been identified in foods in China, but little information is available regarding MRSA in ready-to-eat (RTE) foods. We aimed to investigate the prevalence of S. aureus and MRSA in Chinese retail RTE foods. All isolated S. aureus were tested for antimicrobial susceptibility, and MRSA isolates were further characterized by multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. Of the 550 RTE foods collected from 2011 to 2014, 69 (12.5%) were positive for S. aureus. Contamination levels were mostly in the range of 0.3–10 most probable number (MPN)/g, with five samples exceeding 10 MPN/g. Of the 69 S. aureus isolates, seven were identified as MRSA by cefoxitin disc diffusion test. Six isolates were mecA-positive, while no mecC-positive isolates were identified. In total, 75.8% (47/62) of the methicillin-susceptible S. aureus isolates and all of the MRSA isolates were resistant to three or more antibiotics. Amongst the MRSA isolates, four were identified as community-acquired strains (ST59-MRSA-IVa (n = 2), ST338-MRSA-V, ST1-MRSA-V), while one was a livestock-associated strain (ST9, harboring an unreported SCCmec type 2C2). One novel sequence type was identified (ST3239), the SCCmec gene of which could not be typed. Overall, our findings showed that Chinese retail RTE foods are likely vehicles for transmission of multidrug-resistant S. aureus and MRSA lineages. This is a serious public health risk and highlights the need to implement good hygiene practices. PMID:27375562

Virulence Factors and Antibiotic Susceptibility of Staphylococcus aureus Isolates in Ready-to-Eat Foods: Detection of S. aureus Contamination and a High Prevalence of Virulence Genes

PubMed Central

Puah, Suat Moi; Chua, Kek Heng; Tan, Jin Ai Mary Anne

2016-01-01

Staphylococcus aureus is one of the leading causes of food poisoning. Its pathogenicity results from the possession of virulence genes that produce different toxins which result in self-limiting to severe illness often requiring hospitalization. In this study of 200 sushi and sashimi samples, S. aureus contamination was confirmed in 26% of the food samples. The S. aureus isolates were further characterized for virulence genes and antibiotic susceptibility. A high incidence of virulence genes was identified in 96.2% of the isolates and 20 different virulence gene profiles were confirmed. DNA amplification showed that 30.8% (16/52) of the S. aureus carried at least one SE gene which causes staphylococcal food poisoning. The most common enterotoxin gene was seg (11.5%) and the egc cluster was detected in 5.8% of the isolates. A combination of hla and hld was the most prevalent coexistence virulence genes and accounted for 59.6% of all isolates. Antibiotic resistance studies showed tetracycline resistance to be the most common at 28.8% while multi-drug resistance was found to be low at 3.8%. In conclusion, the high rate of S. aureus in the sampled sushi and sashimi indicates the need for food safety guidelines. PMID:26861367

Virulence Factors and Antibiotic Susceptibility of Staphylococcus aureus Isolates in Ready-to-Eat Foods: Detection of S. aureus Contamination and a High Prevalence of Virulence Genes.

PubMed

Puah, Suat Moi; Chua, Kek Heng; Tan, Jin Ai Mary Anne

2016-02-05

Staphylococcus aureus is one of the leading causes of food poisoning. Its pathogenicity results from the possession of virulence genes that produce different toxins which result in self-limiting to severe illness often requiring hospitalization. In this study of 200 sushi and sashimi samples, S. aureus contamination was confirmed in 26% of the food samples. The S. aureus isolates were further characterized for virulence genes and antibiotic susceptibility. A high incidence of virulence genes was identified in 96.2% of the isolates and 20 different virulence gene profiles were confirmed. DNA amplification showed that 30.8% (16/52) of the S. aureus carried at least one SE gene which causes staphylococcal food poisoning. The most common enterotoxin gene was seg (11.5%) and the egc cluster was detected in 5.8% of the isolates. A combination of hla and hld was the most prevalent coexistence virulence genes and accounted for 59.6% of all isolates. Antibiotic resistance studies showed tetracycline resistance to be the most common at 28.8% while multi-drug resistance was found to be low at 3.8%. In conclusion, the high rate of S. aureus in the sampled sushi and sashimi indicates the need for food safety guidelines.

Survey of methicillin-resistant Staphylococcus aureus (MRSA) carriage in healthy college students, Hawai'i.

PubMed

Morita, Jennifer E; Fujioka, Roger S; Tice, Alan D; Berestecky, John; Sato, Dayna; Seifried, Steven E; Katz, Alan R

2007-08-01

Currently, the carriage rate for Community-Acquired Methicillin Resistant Staphylococcus aureus (CA-MRSA) is unknown in Hawai'i. This survey focuses on a healthy population of 95 college students and 5 faculty who completed a survey related to possible risk factors for colonization of Staphylococcus aureus and were sampled for S. aureus from their anterior nares. Thirty-three (33%) subjects were carrying Staphylococcus aureus and of those, 3 (3%) carried MRSA. There was no significant association between Staphylococcus aureus carriage and ethnicity, gender exposure to seawater, prior Staphylococcus aureus infections, recent antibiotic use, or pets. Additional testing of a larger group of healthy individuals would be beneficial in assessing factors associated with CA-MRSA and Methicillin-susceptible Staphylococcus aureus (MSSA) carriage in Hawai'i.

Methicillin-resistant Staphylococcus argenteus misidentified as methicillin-resistant Staphylococcus aureus emerging in western Sweden.

PubMed

Tång Hallbäck, Erika; Karami, Nahid; Adlerberth, Ingegerd; Cardew, Sofia; Ohlén, Maria; Engström Jakobsson, Hedvig; Svensson Stadler, Liselott

2018-05-17

Two strains included in a whole-genome sequencing project for methicillin-resistant Staphylococcus aureus (MRSA) were identified as non-Staphylococcus aureus when the sequences were analysed using the bioinformatics software ALEX (www.1928diagnostics.com, Gothenburg, Sweden). Sequencing of the sodA gene of these strains identified them as Staphylococcus argenteus. The collection of MRSA in western Sweden was checked for additional strains of this species. A total of 18 strains of S. argenteus isolated between 2011 and December 2017 were identified.

Short communication: Outbreak of methicillin-resistant Staphylococcus aureus (MRSA)-associated mastitis in a closed dairy herd.

PubMed

Guimarães, F F; Manzi, M P; Joaquim, S F; Richini-Pereira, V B; Langoni, H

2017-01-01

Cows are probably the main source of contamination of raw milk with Staphylococcus aureus. Mammary glands with subclinical mastitis can shed large numbers of Staph. aureus in milk. Because of the risk of this pathogen to human health as well as animal health, the aim of this paper was to describe an outbreak of mastitis caused by methicillin-resistant Staph. aureus (MRSA), oxacillin-susceptible mecA-positive Staph. aureus (OS-MRSA), and methicillin-susceptible Staph. aureus (MSSA) on a dairy farm. Milk samples were obtained from all quarters, showing an elevated somatic cell count by the California Mastitis Test. The isolates were identified by phenotypic and genotypic methods. Staphylococcus spp. were isolated from 53% (61/115) of the milk samples, with 60 isolates identified as Staph. aureus (98.4%) and 1 isolate identified as Staphylococcus epidermidis (1.6%). The presence of the mecA gene was verified in 48.3% of Staph. aureus isolates. Of the Staph. aureus isolates, 23.3% were MRSA and 25.0% were OS-MRSA. The total of mastitis cases infected with MRSA was 12.2%. The detection of this large percentage of mastitis cases caused by MRSA and OS-MRSA is of great concern for the animals' health, because β-lactams are still the most important antimicrobials used to treat mastitis. In addition, Staph. aureus isolates causing bovine mastitis represent a public health risk. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Genetic diversity of Staphylococcus aureus in Buruli ulcer.

PubMed

Amissah, Nana Ama; Glasner, Corinna; Ablordey, Anthony; Tetteh, Caitlin S; Kotey, Nana Konama; Prah, Isaac; van der Werf, Tjip S; Rossen, John W; van Dijl, Jan Maarten; Stienstra, Ymkje

2015-02-01

Buruli ulcer (BU) is a necrotizing skin disease caused by Mycobacterium ulcerans. Previous studies have shown that wounds of BU patients are colonized with M. ulcerans and several other microorganisms, including Staphylococcus aureus, which may interfere with wound healing. The present study was therefore aimed at investigating the diversity and topography of S. aureus colonizing BU patients during treatment. We investigated the presence, diversity, and spatio-temporal distribution of S. aureus in 30 confirmed BU patients from Ghana during treatment. S. aureus was isolated from nose and wound swabs, and by replica plating of wound dressings collected bi-weekly from patients. S. aureus isolates were characterized by multiple-locus variable number tandem repeat fingerprinting (MLVF) and spa-typing, and antibiotic susceptibility was tested. Nineteen (63%) of the 30 BU patients tested positive for S. aureus at least once during the sampling period, yielding 407 S. aureus isolates. Detailed analysis of 91 isolates grouped these isolates into 13 MLVF clusters and 13 spa-types. Five (26%) S. aureus-positive BU patients carried the same S. aureus genotype in their anterior nares and wounds. S. aureus isolates from the wounds of seven (37%) patients were distributed over two different MLVF clusters. Wounds of three (16%) patients were colonized with isolates belonging to two different genotypes at the same time, and five (26%) patients were colonized with different S. aureus types over time. Five (17%) of the 30 included BU patients tested positive for methicillin-resistant S. aureus (MRSA). The present study showed that the wounds of many BU patients were contaminated with S. aureus, and that many BU patients from the different communities carried the same S. aureus genotype during treatment. This calls for improved wound care and hygiene.

Distribution of bacterial contamination in a teaching hospital in Tehran - a special focus on Staphylococcus aureus.

PubMed

Mirzaii, Mehdi; Emaneini, Mohammad; Maleknejad, Parviz; Jonaidi, Nematollah; Fooladi, Abbas Ali Imani; Aligholi, Marzieh; Jabalameli, Fereshteh; Halimi, Shahnaz; Taherikalani, Morovat; Kasaeian, Amir

2012-03-01

There are documents that confirm the cycle of bacterial transmission between patients, staff, and the inanimate environment. The environment may have more effect on intensive care units (ICUs), because the patients who require intensive care have unstable clinical conditions and are more sensitive to infections. The aim of this study was to determine the prevalence of bacteria in air and inanimate surface in the ICUs and to compare the microbial levels to standard levels.Air and inanimate surface in the four ICUs of a teaching hospital underwent weekly surveillance by means of air sampler and swabs for a period of six-month. Total bacterial counts were evaluated onto trypticase soy agar and mannitol salt agar (MSA).A total of 725 samples [air (168) and inanimate surfaces (557)] were collected. The total mean ± SD CFU/m3 of airborne bacteria in all of the ICUs were 115.93 ± 48.04. The most common bacteria in air of the ICUs were Gram-positive cocci (84.2%). The total mean ± SD airborne of Staphylococcus aureus was 12.10±8.11 CFU/m3. The highest levels of S. aureus contamination were found in ventilators and bed ledges. More suitable disinfection of hospital environments and monthly rotation in utilization of the various disinfectant agents are needed for the prevention of airborne and inanimate transmission of S. aureus.

Antimicrobial Properties of Selected Copper Alloys on Staphylococcus aureus and Escherichia coli in Different Simulations of Environmental Conditions: With vs. without Organic Contamination.

PubMed

Różańska, Anna; Chmielarczyk, Agnieszka; Romaniszyn, Dorota; Sroka-Oleksiak, Agnieszka; Bulanda, Małgorzata; Walkowicz, Monika; Osuch, Piotr; Knych, Tadeusz

2017-07-20

Background: Hospital equipment made from copper alloys can play an important role in complementing traditional methods of disinfection. Aims of the study: The aim of this study was to assess the dynamics of the antimicrobial properties of selected copper alloys in different simulations of environmental conditions (with organic contamination vs. without organic contamination), and to test alternatives to the currently used testing methods. Materials and Methods: A modification of Japanese standard JIS Z 2801 as well as Staphylococcus aureus (SA) and Escherichia coli (EC) suspended in NaCl vs. tryptic soy broth (TSB) were used in tests performed on seven commonly used copper alloys, copper, and stainless steel. Results: A much faster reduction of the bacterial suspension was observed for the inoculum prepared in NaCl than in TSB. A faster reduction for EC than for SA was observed in the inoculum prepared in NaCl. The opposite results were found for the inoculum based on TSB. A significant correlation between the copper concentration in the copper alloys and the time and degree of bacterial suspension reduction was only observed in the case of EC. Conclusions: This study confirmed the antimicrobial properties of copper alloys, and additionally showed that Staphylococcus aureus was more resistant than Escherichia coli in the variant of the experiment without organic contamination. However, even for SA, a total reduction of the bacterial inoculum's density took no longer than 2 h. Under conditions simulating organic contamination, all of the tested alloys were shown to have bactericidal or bacteriostatic properties, which was contrary to the results from stainless steel.

Quantitative Proteomic Analyses of Staphylococcus aureus Treated with Punicalagin, a Natural Antibiotic from Pomegranate that Disrupts Iron Homeostasis and Induces SOS

USDA-ARS?s Scientific Manuscript database

Staphylococcus aureus, a bacterial, food-borne pathogen of humans, can contaminate raw fruits and vegetables. While physical and chemical methods are available to control S. aureus, scientists are searching for inhibitory phytochemicals from plants. One promising compound from pomegranate is punica...

Assessment of Enterotoxin Production and Cross-Contamination of Staphylococcus aureus between Food Processing Materials and Ready-To-Eat Cooked Fish Paste.

PubMed

Tango, Charles Nkufi; Hong, Sung-Sam; Wang, Jun; Oh, Deog-Hwan

2015-12-01

This study evaluated Staphylococcus aureus growth and subsequent staphylococcal enterotoxin A production in tryptone soy broth and on ready-to-eat cooked fish paste at 12 to 37 °C, as well as cross-contamination between stainless steel, polyethylene, and latex glove at room temperature. A model was developed using Barany and Roberts's growth model, which satisfactorily described the suitable growth of S. aureus with R(2)-adj from 0.94 to 0.99. Except at 12 °C, S. aureus cells in TSB presented a lag time lower (14.64 to 1.65 h), grew faster (0.08 to 0.31 log CFU/h) and produced SEA at lower cell density levels (5.65 to 6.44 log CFU/mL) compare to those inoculated on cooked fish paste with data of 16.920 to 1.985 h, 0.02 to 0.23 log CFU/h, and 6.19 to 7.11 log CFU/g, respectively. Staphylococcal enterotoxin type A (SEA) visual immunoassay test showed that primary SEA detection varied considerably among different storage temperature degrees and media. For example, it occurred only during exponential phase at 30 and 37 °C in TSB, but in cooked fish paste it took place at late exponential phase of S. aureus growth at 20 and 25 °C. The SEA detection test was negative on presence of S. aureus on cooked fish paste stored at 12 and 15 °C, although cell density reached level of 6.12 log CFU/g at 15 °C. Cross-contamination expressed as transfer rate of S. aureus from polyethylene surface to cooked fish paste surface was slower than that observed with steel surface to cooked fish paste under same conditions. These results provide helpful information for controlling S. aureus growth, SEA production and cross-contamination during processing of cooked fish paste. © 2015 Institute of Food Technologists®

Differentiation between Staphylococcus aureus and Staphylococcus epidermidis strains using Raman spectroscopy.

PubMed

Rebrošová, Katarína; Šiler, Martin; Samek, Ota; Růžička, Filip; Bernatová, Silvie; Ježek, Jan; Zemánek, Pavel; Holá, Veronika

2017-08-01

Raman spectroscopy is an analytical method with a broad range of applications across multiple scientific fields. We report on a possibility to differentiate between two important Gram-positive species commonly found in clinical material - Staphylococcus aureus and Staphylococcus epidermidis - using this rapid noninvasive technique. For this, we tested 87 strains, 41 of S. aureus and 46 of S. epidermidis, directly from colonies grown on a Mueller-Hinton agar plate using Raman spectroscopy. The method paves a way for separation of these two species even on high number of samples and therefore, it can be potentially used in clinical diagnostics.

Characterization of staphylococci in urban wastewater treatment plants in Spain, with detection of methicillin resistant Staphylococcus aureus ST398.

PubMed

Gómez, Paula; Lozano, Carmen; Benito, Daniel; Estepa, Vanesa; Tenorio, Carmen; Zarazaga, Myriam; Torres, Carmen

2016-05-01

Staphylococcus spp. are normal contaminants of urban wastewater, including different lineages of S. aureus and a high diversity of coagulase-negative species. The presence of multiple resistance and virulence genes, including mecA, in staphylococci of wastewater can be a concern for the public health. Copyright © 2016 Elsevier Ltd. All rights reserved.

Community-Acquired Methicillin-Resistant "Staphylococcus aureus": Considerations for School Nurses

ERIC Educational Resources Information Center

Alex, Aniltta; Letizia, MariJo

2007-01-01

Methicillin-resistant "Staphylococcus aureus" (MRSA) is a disease-causing organism that has been present in hospital settings since the 1960s. However, a genetically distinct strain of MRSA, called community-acquired methicillin-resistant "Staphylococcus aureus" (CA-MRSA), has emerged in recent years in community settings among healthy…

TOLERANCE OF STAPHYLOCOCCUS AUREUS TO SODIUM CHLORIDE

PubMed Central

Parfentjev, I. A.; Catelli, Anna R.

1964-01-01

Parfentjev, I. A. (Institute of Applied Biology, New York, N.Y.), and Anna R. Catelli. Tolerance of Staphylococcus aureus to sodium chloride. J. Bacteriol. 88:1–3. 1964.—The tolerance of Staphylococcus aureus to high concentrations of sodium chloride in liquid medium has been reported. We found that S. aureus grows at 37 C in Tryptose Phosphate Broth saturated with sodium chloride. No difference was noticed between possibly pathogenic and nonpathogenic strains. Under the conditions of our tests, no changes in the original properties of S. aureus strains occurred. In contrast, solutions of sodium chloride in distilled water were injurious to staphylococci and killed most of these organisms in 1 hr. Staphylococci were killed faster at 37 C than at room temperature in a solution of 0.85% sodium chloride in water. Addition of traces of Tryptose Phosphate Broth had a protective effect and prolonged the life of these organisms in physiological saline. All tests were performed at pH 7.2. PMID:14197887

Whole Genome Sequencing of Danish Staphylococcus argenteus Reveals a Genetically Diverse Collection with Clear Separation from Staphylococcus aureus.

PubMed

Hansen, Thomas A; Bartels, Mette D; Høgh, Silje V; Dons, Lone E; Pedersen, Michael; Jensen, Thøger G; Kemp, Michael; Skov, Marianne N; Gumpert, Heidi; Worning, Peder; Westh, Henrik

2017-01-01

Staphylococcus argenteus ( S. argenteus ) is a newly identified Staphylococcus species that has been misidentified as Staphylococcus aureus ( S. aureus ) and is clinically relevant. We identified 25 S. argenteus genomes in our collection of whole genome sequenced S. aureus . These genomes were compared to publicly available genomes and a phylogeny revealed seven clusters corresponding to seven clonal complexes. The genome of S. argenteus was found to be different from the genome of S. aureus and a core genome analysis showed that ~33% of the total gene pool was shared between the two species, at 90% homology level. An assessment of mobile elements shows flow of SCC mec cassettes, plasmids, phages, and pathogenicity islands, between S. argenteus and S. aureus . This dataset emphasizes that S. argenteus and S. aureus are two separate species that share genetic material.

Antimicrobial Properties of Selected Copper Alloys on Staphylococcus aureus and Escherichia coli in Different Simulations of Environmental Conditions: With vs. without Organic Contamination

PubMed Central

Różańska, Anna; Chmielarczyk, Agnieszka; Romaniszyn, Dorota; Sroka-Oleksiak, Agnieszka; Bulanda, Małgorzata; Walkowicz, Monika; Osuch, Piotr; Knych, Tadeusz

2017-01-01

Background: Hospital equipment made from copper alloys can play an important role in complementing traditional methods of disinfection. Aims of the study: The aim of this study was to assess the dynamics of the antimicrobial properties of selected copper alloys in different simulations of environmental conditions (with organic contamination vs. without organic contamination), and to test alternatives to the currently used testing methods. Materials and Methods: A modification of Japanese standard JIS Z 2801 as well as Staphylococcus aureus (SA) and Escherichia coli (EC) suspended in NaCl vs. tryptic soy broth (TSB) were used in tests performed on seven commonly used copper alloys, copper, and stainless steel. Results: A much faster reduction of the bacterial suspension was observed for the inoculum prepared in NaCl than in TSB. A faster reduction for EC than for SA was observed in the inoculum prepared in NaCl. The opposite results were found for the inoculum based on TSB. A significant correlation between the copper concentration in the copper alloys and the time and degree of bacterial suspension reduction was only observed in the case of EC. Conclusions: This study confirmed the antimicrobial properties of copper alloys, and additionally showed that Staphylococcus aureus was more resistant than Escherichia coli in the variant of the experiment without organic contamination. However, even for SA, a total reduction of the bacterial inoculum’s density took no longer than 2 h. Under conditions simulating organic contamination, all of the tested alloys were shown to have bactericidal or bacteriostatic properties, which was contrary to the results from stainless steel. PMID:28726753

Biochemical and Molecular Analysis of Staphylococcus aureus Clinical Isolates from Hospitalized Patients.

PubMed

Karmakar, Amit; Dua, Parimal; Ghosh, Chandradipa

2016-01-01

Staphylococcus aureus is opportunistic human as well as animal pathogen that causes a variety of diseases. A total of 100 Staphylococcus aureus isolates were obtained from clinical samples derived from hospitalized patients. The presumptive Staphylococcus aureus clinical isolates were identified phenotypically by different biochemical tests. Molecular identification was done by PCR using species specific 16S rRNA primer pairs and finally 100 isolates were found to be positive as Staphylococcus aureus. Screened isolates were further analyzed by several microbiological diagnostics tests including gelatin hydrolysis, protease, and lipase tests. It was found that 78%, 81%, and 51% isolates were positive for gelatin hydrolysis, protease, and lipase activities, respectively. Antibiogram analysis of isolated Staphylococcus aureus strains with respect to different antimicrobial agents revealed resistance pattern ranging from 57 to 96%. Our study also shows 70% strains to be MRSA, 54.3% as VRSA, and 54.3% as both MRSA and VRSA. All the identified isolates were subjected to detection of mecA, nuc, and hlb genes and 70%, 84%, and 40% were found to harbour mecA, nuc, and hlb genes, respectively. The current investigation is highly important and informative for the high level multidrug resistant Staphylococcus aureus infections inclusive also of methicillin and vancomycin.

Selective biosensing of Staphylococcus aureus using chitosan quantum dots

NASA Astrophysics Data System (ADS)

Abdelhamid, Hani Nasser; Wu, Hui-Fen

2018-01-01

Selective biosensing of Staphylococcus aureus (S. aureus) using chitosan modified quantum dots (CTS@CdS QDs) in the presence of hydrogen peroxide is reported. The method is based on the intrinsic positive catalase activity of S. aureus. CTS@CdS quantum dots provide high dispersion in aqueous media with high fluorescence emission. Staphylococcus aureus causes a selective quenching of the fluorescence emission of CTS@CdS QDs in the presence of H2O2 compared to other pathogens such as Escherichia coli and Pseudomonas aeruginosa. The intrinsic enzymatic character of S. aureus (catalase positive) offers selective and fast biosensing. The present method is highly selective for positive catalase species and requires no expensive reagents such as antibodies, aptamers or microbeads. It could be extended for other species that are positive catalase.

Concurrent infectious mononucleosis and community-associated methicillin-resistant Staphylococcus aureus bacteremia.

PubMed

Wang, Li Jun; Du, Xiao Qin; Nyirimigabo, Eric; Shou, Song Tao

2014-04-01

It is rare to see a concurrent infection with infectious mononucleosis and community-associated methicillin-resistant Staphylococcus aureus in Tianjin, China. Until now, there is still no any single recorded case of concurrent infectious mononucleosis and community-associated methicillin-resistant Staphylococcus aureus bacteremia.

Staphylococcus aureus Entrance into the Dairy Chain: Tracking S. aureus from Dairy Cow to Cheese

PubMed Central

Kümmel, Judith; Stessl, Beatrix; Gonano, Monika; Walcher, Georg; Bereuter, Othmar; Fricker, Martina; Grunert, Tom; Wagner, Martin; Ehling-Schulz, Monika

2016-01-01

Staphylococcus aureus is one of the most important contagious mastitis pathogens in dairy cattle. Due to its zoonotic potential, control of S. aureus is not only of great economic importance in the dairy industry but also a significant public health concern. The aim of this study was to decipher the potential of bovine udder associated S. aureus as reservoir for S. aureus contamination in dairy production and processing. From 18 farms, delivering their milk to an alpine dairy plant for the production of smeared semi-hard and hard cheese. one thousand hundred seventy six one thousand hundred seventy six quarter milk (QM) samples of all cows in lactation (n = 294) and representative samples form bulk tank milk (BTM) of all farms were surveyed for coagulase positive (CPS) and coagulase negative Staphylococci (CNS). Furthermore, samples from different steps of the cheese manufacturing process were tested for CPS and CNS. As revealed by chemometric-assisted FTIR spectroscopy and molecular subtyping (spa typing and multi locus sequence typing), dairy cattle represent indeed an important, yet underreported, entrance point of S. aureus into the dairy chain. Our data clearly show that certain S. aureus subtypes are present in primary production as well as in the cheese processing at the dairy plant. However, although a considerable diversity of S. aureus subtypes was observed in QM and BTM at the farms, only certain S. aureus subtypes were able to enter and persist in the cheese manufacturing at the dairy plant and could be isolated from cheese until day 14 of ripening. Farm strains belonging to the FTIR cluster B1 and B3, which show genetic characteristics (t2953, ST8, enterotoxin profile: sea/sed/sej) of the recently described S. aureus genotype B, most successfully contaminated the cheese production at the dairy plant. Thus, our study fosters the hypothesis that genotype B S. aureus represent a specific challenge in control of S. aureus in the dairy chain that requires

Antimicrobial susceptibility of Staphylococcus aureus and Staphylococcus pseudintermedius isolated from various animals

PubMed Central

Rubin, Joseph E.; Ball, Katherine R.; Chirino-Trejo, Manuel

2011-01-01

This study characterized the antimicrobial susceptibility of 221 Staphylococcus aureus isolated from various species, and 60 canine Staphylococcus pseudintermedius isolated from 1986 through 2000 at the Western College of Veterinary Medicine (WCVM). Resistance of S. aureus was most common to penicillin (31%) and tetracycline (14%); resistance of S. pseudintermedius to penicillin was present in 8% and to tetracycline in 34% of isolates. Resistance to trimethoprim/sulfamethoxazole was only seen among S. pseudintermedius, and there was no resistance to amoxicillin/clavulanate, ampicillin/sulbactam, cephalothin, amikacin, gentamicin, enrofloxacin, chloramphenicol, or rifampin among any isolate. Inducible clindamycin resistance was found in both S. aureus and S. pseudintermedius, highlighting the need for careful interpretation of culture and susceptibility test results. There were significant differences in the minimum inhibitory concentrations of penicillin, ciprofloxacin, enrofloxacin, clindamycin, erythromycin, chloramphenicol, and tetracycline between avian, bovine, equine, and porcine isolates. PMID:21532820

Molecular detection of Staphylococcus aureus resistant to temperature in milk and its products

NASA Astrophysics Data System (ADS)

Sutejo, Stephani Valentina Harda; Amarantini, Charis; Budiarso, Tri Yahya

2017-11-01

Contamination of Staphylococcus aureus on milk can cause intoxication and infection by Staphylococcal enterotoxin. It has nuc gene, coding thermonuclease enzyme (TNase) that is responsible for nature of resistance in the heating process. This study was conducted to identify nuc gene of as S. aureus isolated from milk and its products like ultra-high temperature, sterile milk, sweetened condensed milk, formula milk, café/milk street traders and fresh milk. Biochemical identification was conducted by using carbohydrate fermentation tests and confirmed by API Staph. Molecular confirmation by amplification of nuc gene using PCR. Based on the results of confirmation using API Staph, all isolates were confirmed as S. aureus with index determinant percentage of 97%. An amplicon product of 270 bp was gained in all isolates. It is concluded that isolate of S. aureus has nuc gene.

Staphylococcus aureus infections following knee and hip prosthesis insertion procedures.

PubMed

Arduino, Jean Marie; Kaye, Keith S; Reed, Shelby D; Peter, Senaka A; Sexton, Daniel J; Chen, Luke F; Hardy, N Chantelle; Tong, Steven Yc; Smugar, Steven S; Fowler, Vance G; Anderson, Deverick J

2015-01-01

Staphylococcus aureus is the most common and most important pathogen following knee and hip arthroplasty procedures. Understanding the epidemiology of invasive S. aureus infections is important to quantify this serious complication. This nested retrospective cohort analysis included adult patients who had undergone insertion of knee or hip prostheses with clean or clean-contaminated wound class at 11 hospitals between 2003-2006. Invasive S. aureus infections, non-superficial incisional surgical site infections (SSIs) and blood stream infections (BSIs), were prospectively identified following each procedure. Prevalence rates, per 100 procedures, were estimated. 13,719 prosthetic knee (62%) and hip (38%) insertion procedures were performed. Of 92 invasive S. aureus infections identified, SSIs were more common (80%) than SSI and BSI (10%) or BSI alone (10%). The rate of invasive S. aureus infection/100 procedures was 0.57 [95% CI: 0.43-0.73] for knee insertion and 0.83 [95% CI: 0.61-1.08] for hip insertion. More than half (53%) were methicillin-resistant. Median time-to-onset of infection was 34 and 26 days for knee and hip insertion, respectively. Infection was associated with higher National Healthcare Safety Network risk index (p ≤ 0.0001). Post-operative invasive S. aureus infections were rare, but difficult-to-treat methicillin-resistant infections were relatively common. Optimizing preventative efforts may greatly reduce the healthcare burden associated with S. aureus infections.

Detecting Staphylococcus aureus in milk from dairy cows using sniffer dogs.

PubMed

Fischer-Tenhagen, C; Theby, V; Krömker, V; Heuwieser, W

2018-05-01

Fast and accurate identification of disease-causing pathogens is essential for specific antimicrobial therapy in human and veterinary medicine. In these experiments, dogs were trained to identify Staphylococcus aureus and differentiate it from other common mastitis-causing pathogens by smell. Headspaces from agar plates, inoculated raw milk samples, or field samples collected from cows with Staphylococcus aureus and other mastitis-causing pathogens were used for training and testing. The ability to learn the specific odor of Staphylococcus aureus in milk depended on the concentration of the pathogens in the training samples. Sensitivity and specificity for identifying Staphylococcus aureus were 91.3 and 97.9%, respectively, for pathogens grown on agar plates; 83.8 and 98.0% for pathogens inoculated in raw milk; and 59.0 and 93.2% for milk samples from mastitic cows. The results of these experiments underline the potential of odor detection as a diagnostic tool for pathogen diagnosis. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Colonization of butchers with livestock-associated methicillin-resistant Staphylococcus aureus.

PubMed

Boost, M; Ho, J; Guardabassi, L; O'Donoghue, M

2013-12-01

Reports have documented colonization of swine in Europe, North America and more recently in China with livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA). Contamination of pig farmers, veterinarians and abattoir workers with these strains has been observed. However, although contamination levels of 10% of retail pork were reported from the Netherlands and Canada, there are limited data of contamination rates of workers handling raw meat. We investigated the rates of MRSA contamination of local butchers working in wet markets, where recently slaughtered pigs are cut up. Nasal swabs collected from 300 pork butchers at markets throughout Hong Kong were enriched in brain heart infusion broth with 5% salt and cultured on MRSASelect(®) . Isolates were confirmed as Staphylococcus aureus and susceptibility testing performed. The presence of mecA was confirmed, SCCmec and spa type determined and relatedness investigated by PFGE. Subjects completed a questionnaire on MRSA carriage risk factors. Seventeen samples (5.6%) yielded MRSA, 15 harbouring SCCmec IVb. Ten strains were t899 (CC9), previously reported from local pig carcasses. Five strains were healthcare associated: SCCmec type II, t701(CC6), colonizing two subjects at the same establishment, and single isolates of t008 (CC8), t002 (CC5) and t123 (CC45). The remaining isolates were t359 (CC97), previously reported from buffaloes, and t375 (CC5), reported from bovine milk. None of these butchers reported recent hospitalization or a healthcare worker in the family. Two had recently received antibiotics, one for a skin infection. Four reported wound infections within the last year. All were exposed to meat for >9 h per day. Carriage of MRSA was higher in butchers than in the general community. Although five strains were probably of healthcare origin, the high incidence of t899 (CC9) suggests that cross-contamination from pork occurs frequently. Washing of hands after touching raw pork is advised

Isolation, Virulence, and Antimicrobial Resistance of Methicillin-Resistant Staphylococcus aureus (MRSA) and Methicillin Sensitive Staphylococcus aureus (MSSA) Strains from Oklahoma Retail Poultry Meats.

PubMed

Abdalrahman, Lubna S; Stanley, Adriana; Wells, Harrington; Fakhr, Mohamed K

2015-05-29

Staphylococcus aureus is one the top five pathogens causing domestically acquired foodborne illness in the U.S. Only a few studies are available related to the prevalence of S. aureus and MRSA in the U.S. retail poultry industry. The objectives of this study were to determine the prevalence of S. aureus (MSSA and MRSA) in retail chicken and turkey meats sold in Tulsa, Oklahoma and to characterize the recovered strains for their antimicrobial resistance and possession of toxin genes. A total of 167 (114 chicken and 53 turkey) retail poultry samples were used in this study. The chicken samples included 61 organic samples while the rest of the poultry samples were conventional. The overall prevalence of S. aureus was 57/106 (53.8%) in the conventional poultry samples and 25/61 (41%) in the organic ones. Prevalence in the turkey samples (64.2%) was higher than in the chicken ones (42.1%). Prevalence of S. aureus did not vary much between conventional (43.4%) and organic chicken samples (41%). Two chicken samples 2/114 (1.8%) were positive for MRSA. PFGE identified the two MRSA isolates as belonging to PFGE type USA300 (from conventional chicken) and USA 500 (from organic chicken) which are community acquired CA-MRSA suggesting a human based source of contamination. MLST and spa typing also supported this conclusion. A total of 168 Staphylococcus aureus isolates (101 chicken isolates and 67 turkey isolates) were screened for their antimicrobial susceptibility against 16 antimicrobials and their possession of 18 different toxin genes. Multidrug resistance was higher in the turkey isolates compared to the chicken ones and the percentage of resistance to most of the antimicrobials tested was also higher among the turkey isolates. The hemolysin hla and hld genes, enterotoxins seg and sei, and leucocidins lukE-lukD were more prevalent in the chicken isolates. The PVL gene lukS-lukF was detected only in chicken isolates including the MRSA ones. In conclusion, S. aureus is

[Change in drug resistance of Staphylococcus aureus].

PubMed

Lin, Yan; Liu, Yan; Luo, Yan-Ping; Liu, Chang-Ting

2013-11-01

To analyze the change in drug resistance of Staphylococcus aureus (SAU) in the PLA general hospital from January 2008 to December 2012, and to provide solid evidence to support the rational use of antibiotics for clinical applications. The SAU strains isolated from clinical samples in the hospital were collected and subjected to the Kirby-Bauer disk diffusion test. The results were assessed based on the 2002 American National Committee for Clinical Laboratory Standards (NCCLS) guidelines. SAU strains were mainly isolated from sputum, urine, blood and wound excreta and distributed in penology, neurology wards, orthopedics and surgery ICU wards. Except for glycopeptide drugs, methicillin-resistant Staphylococcus aureus (MRSA) had a higher drug resistance rate than those of the other drugs and had significantly more resistance than methicillin-sensitive Staphylococcus aureus (MSSA) (P < 0.05). In the dynamic observation of drug resistance, we discovered a gradual increase in drug resistance to fourteen test drugs during the last five years. Drug resistance rate of SAU stayed at a higher level over the last five years; moreover, the detection ratio of MRSA keeps rising year by year. It is crucial for physicians to use antibiotics rationally and monitor the change in drug resistance in a dynamic way.

Staphylococcus aureus and Staphylococcus epidermidis infections on implants.

PubMed

Oliveira, W F; Silva, P M S; Silva, R C S; Silva, G M M; Machado, G; Coelho, L C B B; Correia, M T S

2018-02-01

Infections are one of the main reasons for removal of implants from patients, and usually need difficult and expensive treatments. Staphylococcus aureus and Staphylococcus epidermidis are the most frequently detected pathogens. We reviewed the epidemiology and pathogenesis of implant-related infections. Relevant studies were identified by electronic searching of the following databases: PubMed, ScienceDirect, Academic Google, and CAPES Journal Portal. This review reports epidemiological studies of implant infections caused by S. aureus and S. epidermidis. We discuss some methodologies used in the search for new compounds with antibiofilm activity and the main strategies for biomaterial surface modifications to avoid bacterial plaque formation and consequent infection. S. aureus and S. epidermidis are frequently involved in infections in catheters and orthopaedic/breast implants. Different methodologies have been used to test the potential antibiofilm properties of compounds; for example, crystal violet dye is widely used for in-vitro biofilm quantification due to its low cost and good reproducibility. Changes in the surface biomaterials are necessary to prevent biofilm formation. Some studies have investigated the immobilization of antibiotics on the surfaces of materials used in implants. Other approaches have been used as a way to avoid the spread of bacterial resistance to antimicrobials, such as the functionalization of these surfaces with silver and natural compounds, as well as the electrical treatment of these substrates. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Characterization of Staphylococcus aureus in Goose Feces from State Parks in Northeast Ohio.

PubMed

Thapaliya, Dipendra; Dalman, Mark; Kadariya, Jhalka; Little, Katie; Mansell, Victoria; Taha, Mohammed Y; Grenier, Dylan; Smith, Tara C

2017-06-01

Staphylococcus aureus can colonize a range of species. Although numerous studies have isolated pathogenic bacteria from wild birds, very little is known regarding S. aureus and their potential to spread methicillin-resistant (MRSA) strains. The objective of this study was to determine the presence and molecular characteristics of S. aureus in geese fecal samples collected from ten state parks across Northeast Ohio (NEO). A total of 182 fecal samples from Canada geese (Branta canadensis) were collected in April 2015. Isolates were characterized using multi-locus sequence (MLST) and spa typing, as well as PCR to detect the presence of Panton-Valentine leukocidin (PVL), mecA, and scn genes. Antibiotic susceptibility testing was done via Vitek-2 system. The overall contamination by S. aureus in fecal samples was 7.1% (13/182); 7/182 (3.8%) were MRSA and 6/182 (3.3%) were methicillin-susceptible S. aureus (MSSA). One isolate was positive for PVL. A total of eight different spa types were observed. MLST included ST5, ST8, ST291, ST298, and ST2111. One (7.7%) MSSA isolate was multi-drug resistant. The S. aureus contamination in NEO state parks ranged from 0% (park 1, 4, 8, 9) to 35% (7/20) (park 5). Parks 2, 3, 6, and 7 had 5% (1/20) positive. The results of this study indicate that the feces of geese collected at various state parks in NEO may harbor S. aureus.

Staphylococcus aureus: methicillin-susceptible S. aureus to methicillin-resistant S. aureus and vancomycin-resistant S. aureus.

PubMed

Rehm, Susan J; Tice, Alan

2010-09-15

The evolution of methicillin-resistant and vancomycin-resistant Staphylococcus aureus has demanded serious review of antimicrobial use and development of new agents and revised approaches to prevent and overcome drug resistance. Depending on local conditions and patient risk factors, empirical therapy of suspected S. aureus infection may require coverage of drug-resistant organisms with newer agents and novel antibiotic combinations. The question of treatment with inappropriate antibiotics raises grave concerns with regard to methicillin-resistant S. aureus selection, overgrowth, and increased virulence. Several strategies to reduce the nosocomial burden of resistance are suggested, including shortened hospital stays and outpatient parenteral antimicrobial therapy of the most serious infections.

Disinfection of rigid nasal endoscopes following in vitro contamination with Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, and Haemophilus influenzae.

PubMed

Bradford, Benjamin D; Seiberling, Kristin A; Park, Francine E; Hiebert, Jared C; Chang, Dennis F

2013-06-01

If not adequately cleaned, rigid nasal endoscopes (RNEs) have the potential to cause iatrogenic cross-contamination. To test the efficacy of various disinfection methods in reducing bacterial load on RNEs in vitro. In vitro model. Staphylococcus aureus, Streptococcus pneumoniae, Pseudomonas aeruginosa, and Haemophilus influenzae contamination was separately induced on RNEs in vitro. Two experimental sets were completed. The RNEs were disinfected using the following protocols: 30-second scrub with antimicrobial soap (ABS) and water, 30-second scrub with 70% isopropyl alcohol (IA), 30-second scrub with ABS followed by 30-second scrub with IA, 30-second scrub with germicidal cloth, isolated 5-minute soak in an enzymatic soap solution, 5- and 10-minute soaks in ortho-phthalaldehyde, 0.55%, solution (Cidex OPA), and isolated 30-second rinse with tap water, all with 30-second precleaning and postcleaning rinses with tap water. Two sets of experiments (experiment sets A and B) were carried out with a 30-second tap water rinse after inoculation of each RNE. This was followed by immediate cleaning in set A and a 1-hour air-dry delay in set B. Otherwise there were no differences in the disinfection protocols between sets for each method noted. Effectiveness of various disinfection protocols in cleaning rigid nasal endoscopes experimentally inoculated with bacteria commonly found in the upper aerodigestive tract. Positive cultures following disinfection indicated ineffective or incomplete disinfection. Most cleaning methods were effective in eliminating S aureus, S pneumoniae, and H influenzae from the scopes following experimental contamination. Continued growth of P aeruginosa was found after all of the disinfection trials in experiment set A with the exception of a 10-minute immersion in Cidex OPA, and in set B except for the 10-minute Cidex OPA immersion and ABS plus IA trials. Most cleaning methods used in our trials appear to properly disinfect RNEs after in vitro

Staphylococcus aureus and Staphylococcal Enterotoxin A in Breaded Chicken Products: Detection and Behavior during the Cooking Process

PubMed Central

Pepe, Olimpia; Blaiotta, Giuseppe; Bucci, Francesca; Anastasio, Marilena; Aponte, Maria; Villani, Francesco

2006-01-01

In this study we examined the presence of Staphylococcus aureus and staphylococcal enterotoxin A (SEA) in 20 industrial breaded chicken products obtained from different retail butchers and supermarket stores in Italy. The levels of contamination in the products analyzed were quite low, although the pH values and water activities (aw) in the samples considered were in ranges favorable for S. aureus growth. As demonstrated by phenotypic and molecular characterization, in spite of the high percentage of coagulase-positive Staphylococcus strains, only three strains could be referred to the species S. aureus. Moreover, all the strains were negative in PCR assays targeting staphylococcal enterotoxin genes (seA to seE, seG to seJ, and seM to seO), as well as the toxic shock syndrome toxin 1 gene, and no SEA was detected in the retail breaded chicken samples analyzed by a reversed passive latex agglutination assay or by Western blotting. Hence, we evaluated the thermal resistance of two strains of SEA-producing S. aureus in a laboratory-scale preparation of precooked breaded chicken cutlets. The heat treatment employed in the manufacture determined the inactivation of S. aureus cells, but the preformed SEA remained active during product storage at 4°C. The presence of the staphylococci and, in particular, of S. aureus in the retail breaded chicken products analyzed is a potential health risk for consumers since the pH and aw values of these kinds of products are favorable for S. aureus growth. The thermal process used during their manufacture can limit staphylococcal contamination but cannot eliminate preformed toxins. PMID:17088378

Staphylococcus aureus and staphylococcal enterotoxin A in breaded chicken products: detection and behavior during the cooking process.

PubMed

Pepe, Olimpia; Blaiotta, Giuseppe; Bucci, Francesca; Anastasio, Marilena; Aponte, Maria; Villani, Francesco

2006-11-01

In this study we examined the presence of Staphylococcus aureus and staphylococcal enterotoxin A (SEA) in 20 industrial breaded chicken products obtained from different retail butchers and supermarket stores in Italy. The levels of contamination in the products analyzed were quite low, although the pH values and water activities (a(w)) in the samples considered were in ranges favorable for S. aureus growth. As demonstrated by phenotypic and molecular characterization, in spite of the high percentage of coagulase-positive Staphylococcus strains, only three strains could be referred to the species S. aureus. Moreover, all the strains were negative in PCR assays targeting staphylococcal enterotoxin genes (seA to seE, seG to seJ, and seM to seO), as well as the toxic shock syndrome toxin 1 gene, and no SEA was detected in the retail breaded chicken samples analyzed by a reversed passive latex agglutination assay or by Western blotting. Hence, we evaluated the thermal resistance of two strains of SEA-producing S. aureus in a laboratory-scale preparation of precooked breaded chicken cutlets. The heat treatment employed in the manufacture determined the inactivation of S. aureus cells, but the preformed SEA remained active during product storage at 4 degrees C. The presence of the staphylococci and, in particular, of S. aureus in the retail breaded chicken products analyzed is a potential health risk for consumers since the pH and a(w) values of these kinds of products are favorable for S. aureus growth. The thermal process used during their manufacture can limit staphylococcal contamination but cannot eliminate preformed toxins.

Propionibacterium acnes biofilm - A sanctuary for Staphylococcus aureus?

PubMed

Tyner, Harmony; Patel, Robin

2016-08-01

The purpose of this study was to measure the effect of combined culture of Propionibacterium acnes and Staphylococcus aureus on biofilm formation under different oxygen concentrations. We measured planktonic growth and biofilm formation of P. acnes and S. aureus alone and together under aerobic and anaerobic conditions. Both P. acnes and S. aureus grew under anaerobic conditions. When grown under anaerobic conditions, P. acnes with or without S. aureus formed a denser biomass biofilm than did S. aureus alone. Viable S. aureus was recovered from a16-day old combined P. acnes and S. aureus biofilm, but not a monomicrobial S. aureus biofilm. Copyright © 2016 Elsevier Ltd. All rights reserved.

Is methicillin-resistant Staphylococcus aureus replacing methicillin-susceptible S. aureus?

PubMed Central

Mostofsky, Elizabeth; Lipsitch, Marc; Regev-Yochay, Gili

2011-01-01

Despite extensive research on the emergence of and treatments for methicillin-resistant Staphylococcus aureus (MRSA), prior studies have not rigorously evaluated the impact of methicillin resistance on the overall incidence of S. aureus infections. Yet, there are direct clinical and research implications of determining whether methicillin-susceptible S. aureus (MSSA) infection rates remain stable in the face of increasing MRSA prevalence or whether MSSA will be replaced over time. A synthesis of prior studies indicates that the emergence of healthcare-associated MRSA (HA-MRSA) and community-associated MRSA (CA-MRSA) has led to an increase in the overall incidence of S. aureus infections, with MRSA principally adding to, rather than replacing, MSSA. However, colonization with CA-MRSA may at least partially replace colonization with MSSA. So far, evidence indicates that MSSA still accounts for many infections. Therefore, eradication of MRSA alone is not sufficient to address the public health burden of S. aureus. PMID:21737459

Prevalence of Staphylococcus, including Methicillin-Resistant Staphylococcus aureus, in a Physical Therapy Education Facility.

PubMed

Dhagat, Priya V; Gibbs, Karen A; Rohde, Rodney E

2015-01-01

The purpose of this study was to assess the prevalence of Staphylococcus species, including methicillin-resistant Staphylococcus aureus (MRSA), in a physical therapy (PT) education facility. The PT laboratory classrooms were routinely used by graduate PT students and faculty, undergraduate anatomy students, and licensed practitioners for continuing education purposes. A total of 88 swab samples were collected from plinths and other equipment and plated onto mannitol salt agar (MSA). Suspected S. aureus colonies were confirmed by Staphyloslide latex testing. S. aureus isolates were plated to HardyCHROM agar to identify MRSA. VITEK antibiotic susceptibility testing confirmed MRSA isolates. Forty-seven samples showed growth (47/88, 53%), and 7 tested positive for S. aureus (7/47, 15%). Of those 7, one demonstrated oxacillin resistance and was confirmed as MRSA (1/7, 2%). Remaining samples grew other species of Staphylococcus and gram-negative bacilli. Given high classroom utilization, staphylococci environmental prevalence would be expected. However, the presence of MRSA was unexpected. Results demonstrate the potential for easily transmissible and potentially harmful organisms to be present in multi-use classrooms utilized by health professions students where frequent skin-to-skin contact occurs. Strict, routine cleaning of plinths and other equipment is imperative in reducing exposure risk.

Run-off studies demonstrate parallel transport behaviour for a marker of poultry fecal contamination and Staphylococcus aureus.

PubMed

Weidhaas, J; Garner, E; Basden, T; Harwood, V J

2014-08-01

To determine whether poultry litter marker gene LA35 is correlated with pathogens and fecal indicator bacteria (FIB) in run-off from poultry litter-amended plots. A rainfall simulator with various vegetative filter strip lengths was employed to evaluate the correlation of a microbial source tracking (MST) marker for poultry feces/litter (the 16S rRNA gene of Brevibacterium sp. LA35 [LA35] measured by quantitative PCR) with pathogens and FIB in run-off. LA35 was correlated with Staphylococcus aureus, Escherichia coli, Enterococcus spp. and Bacteroidales levels. Salmonella was present at low concentration in litter, but became undetectable by qPCR in run-off. Escherichia coli, LA35 and Staph. aureus exhibited mass-based first flush behaviour in the run-off. Correlation of LA35 with FIB and pathogens in run-off from poultry litter-amended fields suggest comparable transport mechanisms and that LA35 is a useful tracer for harmful bacteria in the environment released from poultry litter. To protect human health, an effective marker for poultry fecal contamination should exhibit similar fate and transport characteristics compared to pathogens. This study is among the first to demonstrate such a relationship in run-off for a MST marker. © 2014 The Society for Applied Microbiology.

Enterotoxigenicity and Antimicrobial Resistance of Staphylococcus aureus Isolated from Retail Food in China

PubMed Central

Wang, Wei; Baloch, Zulqarnain; Jiang, Tao; Zhang, Cunshan; Peng, Zixin; Li, Fengqin; Fanning, Séamus; Ma, Aiguo; Xu, Jin

2017-01-01

Staphylococcus aureus is one of the most common causes of zoonotic agent in the world, which are attributable to the contamination of food with enterotoxins. In this study, a total of 1,150 S. aureus isolates were cultured from 27,000 retail foods items from 203 cities of 24 provinces in China in 2015 and were test for antimicrobial susceptibility. Additionally, the role of the genes responsible for the staphylococcal enterotoxins (SEA to SEE), methicillin resistance (mecA) and the toxigenic capabilities were also assessed. The results showed that 4.3% retail foods were contaminated with S. aureus, and 7.9% retail foods isolates were mecA positive. Some 97.6% of S. aureus isolates were resistant to at least one antimicrobial compound, and 57.5% of these were multi drug resistant (MDR). Resistance to penicillin (83.7%, 963/1,150), was common, followed by linezolid (67.7%, 778/1,150) and erythromycin (52.1%, 599/1,150). The isolates cultured from raw meats showed high levels of resistant to tetracycline (42.8%), ciprofloxacin (17.4%), and chloramphenicol (12.0%) and expressed a MDR phenotype (62.4%). A total of 29.7% S. aureus isolates harbored the classical SEs genes (sea, seb, sec, and sed). The sea and seb genes were the most frequent SEs genes detected. Of note, 22% of the SEs genes positive S. aureus harbored two or three SEs genes, and 16 isolates were confirmed with the capacity to simultaneously produce two or three enterotoxin types. Moreover, nearly 50% of the MRSA isolates were positive for at least one SE gene in this study. Therefore, it is important to monitor the antimicrobial susceptibility and enterotoxigenicity of MDR S. aureus and MRSA in the food chain and to use these data to develop food safety measures, designed to reduce the contamination and transmission of this bacterium. PMID:29209290

Enterotoxigenicity and Antimicrobial Resistance of Staphylococcus aureus Isolated from Retail Food in China.

PubMed

Wang, Wei; Baloch, Zulqarnain; Jiang, Tao; Zhang, Cunshan; Peng, Zixin; Li, Fengqin; Fanning, Séamus; Ma, Aiguo; Xu, Jin

2017-01-01

Staphylococcus aureus is one of the most common causes of zoonotic agent in the world, which are attributable to the contamination of food with enterotoxins. In this study, a total of 1,150 S. aureus isolates were cultured from 27,000 retail foods items from 203 cities of 24 provinces in China in 2015 and were test for antimicrobial susceptibility. Additionally, the role of the genes responsible for the staphylococcal enterotoxins (SEA to SEE), methicillin resistance ( mecA ) and the toxigenic capabilities were also assessed. The results showed that 4.3% retail foods were contaminated with S. aureus , and 7.9% retail foods isolates were mecA positive. Some 97.6% of S. aureus isolates were resistant to at least one antimicrobial compound, and 57.5% of these were multi drug resistant (MDR). Resistance to penicillin (83.7%, 963/1,150), was common, followed by linezolid (67.7%, 778/1,150) and erythromycin (52.1%, 599/1,150). The isolates cultured from raw meats showed high levels of resistant to tetracycline (42.8%), ciprofloxacin (17.4%), and chloramphenicol (12.0%) and expressed a MDR phenotype (62.4%). A total of 29.7% S. aureus isolates harbored the classical SEs genes ( sea, seb, sec , and sed ). The sea and seb genes were the most frequent SEs genes detected. Of note, 22% of the SEs genes positive S. aureus harbored two or three SEs genes, and 16 isolates were confirmed with the capacity to simultaneously produce two or three enterotoxin types. Moreover, nearly 50% of the MRSA isolates were positive for at least one SE gene in this study. Therefore, it is important to monitor the antimicrobial susceptibility and enterotoxigenicity of MDR S. aureus and MRSA in the food chain and to use these data to develop food safety measures, designed to reduce the contamination and transmission of this bacterium.

Prevalence and Antibiogram Assessment of Staphylococcus aureus in Beef at Municipal Abattoir and Butcher Shops in Addis Ababa, Ethiopia.

PubMed

Adugna, Feben; Pal, Mahendra; Girmay, Gebrerufael

2018-01-01

A cross-sectional study was conducted from October 2013 to April 2014 to determine the prevalence and antibiotic resistance of Staphylococcus aureus from beef of Addis Ababa Abattoir and butcher shops in Addis Ababa. Seven hundred sixty-eight swab samples were taken from the abattoir and butcher carcasses using a systematic random sampling. One hundred twenty swab samples were also taken from hooks, cutting tables, and knives from the abattoir. Staphylococcus aureus positive isolates were taken for antibiotic susceptibility test. A questionnaire survey was conducted in the abattoir and butcher workers to assess the hygienic practice and possible risk factors regarding the contamination of meat. The prevalence of S. aureus in the abattoir, butcher, cutting table, hook, and knife was 9.4%, 19.8%, 15%, 15%, and 22.5%, respectively. The prevalence of S. aureus in the knife and butcher was found to be 2.8 (OR = 2.8, CI = 1.2-6.4) and 2.4 (OR = 2.4, CI = 1.6-3.6) times that of the abattoir results ( p < 0.01). The antimicrobial susceptibility testing was also conducted on 133 isolates of S. aureus using the disc diffusion susceptibility method. Bacitracin, neomycin, and methicillin were found to be 100% resistant to S. aureus . To avoid the presence of pathogenic Staphylococcus isolates, preventive measures using good hygienic practices during slaughtering and handling of the beef carcasses are recommended.

Nano-TiO2-based photocatalytic disinfection of environmental surfaces contaminated by meticillin-resistant Staphylococcus aureus.

PubMed

Petti, S; Messano, G A

2016-05-01

Traditional cleaning and disinfection methods are inefficient for complete decontamination of hospital surfaces from meticillin-resistant Staphylococcus aureus (MRSA). Additional methods, such as nano-TiO2-based photocatalytic disinfection (PCD), could be helpful. To evaluate anti-MRSA activity of PCD on polyvinyl chloride (PVC) surfaces in natural-like conditions. Two identical PVC surfaces were used, and nano-TiO2 was incorporated into one of them. The surfaces were contaminated with MRSA isolated from hospitalized patients using a mist sprayer to simulate the mode of environmental contamination caused by a carrier. MRSA cell density was assessed before contamination until 180min after contamination using Rodac plates. The differences between test and control surfaces in terms of MRSA density and log MRSA density reduction were assessed using parametric and non-parametric statistical tests. Five strains were tested, and each strain was tested five times. The highest median MRSA densities [46.3 and 43.1 colony-forming units (cfu)/cm(2) for control and test surfaces, respectively] were detected 45min after contamination. Median MRSA densities 180min after contamination were 10.1 and 0.7cfu/cm(2) for control and test surfaces, respectively (P<0.01). Log MRSA density reduction attributable to PCD was 1.16logcfu/cm(2), corresponding to 93% reduction of the baseline MRSA contamination. The disinfectant activity remained stable throughout the 25 testing occasions, despite between-test cleaning and disinfection. The anti-MRSA activity of PCD was compatible with the benchmark for surface hygiene in hospitals (<1cfu/cm(2)), but required 3h of exposure to photocatalysis. Thus, PCD could be considered for non-clinical surfaces. However, for clinical surfaces, PCD should be regarded as supplemental to conventional decontamination procedures, rather than an alternative. Copyright © 2016 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Complete Genome Sequence of the Quality Control Strain Staphylococcus aureus subsp. aureus ATCC 25923

PubMed Central

Treangen, Todd J.; Maybank, Rosslyn A.; Enke, Sana; Friss, Mary Beth; Diviak, Lynn F.; Karaolis, David K. R.; Koren, Sergey; Ondov, Brian; Phillippy, Adam M.; Bergman, Nicholas H.

2014-01-01

Staphylococcus aureus subsp. aureus ATCC 25923 is commonly used as a control strain for susceptibility testing to antibiotics and as a quality control strain for commercial products. We present the completed genome sequence for the strain, consisting of the chromosome and a 27.5-kb plasmid. PMID:25377701

Selenium nanoparticles inhibit Staphylococcus aureus growth

PubMed Central

Tran, Phong A; Webster, Thomas J

2011-01-01

Staphylococcus aureus is a key bacterium commonly found in numerous infections. S. aureus infections are difficult to treat due to their biofilm formation and documented antibiotic resistance. While selenium has been used for a wide range of applications including anticancer applications, the effects of selenium nanoparticles on microorganisms remain largely unknown to date. The objective of this in vitro study was thus to examine the growth of S. aureus in the presence of selenium nanoparticles. Results of this study provided the first evidence of strongly inhibited growth of S. aureus in the presence of selenium nanoparticles after 3, 4, and 5 hours at 7.8, 15.5, and 31 μg/mL. The percentage of live bacteria also decreased in the presence of selenium nanoparticles. Therefore, this study suggests that selenium nanoparticles may be used to effectively prevent and treat S. aureus infections and thus should be further studied for such applications. PMID:21845045

Contamination of environmental surfaces by methicillin-resistant Staphylococcus aureus (MRSA) in rooms of inpatients with MRSA-positive body sites.

PubMed

Kurashige, E Jessica Ohashi; Oie, Shigeharu; Furukawa, H

2016-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) can contaminate environmental surfaces that are frequently touched by the hands of patients with MRSA colonization/infection. There have been many studies in which the presence or absence of MRSA contamination was determined but no studies in which MRSA contamination levels were also evaluated in detail. We evaluated MRSA contamination of environmental surfaces (overbed tables, bed side rails, and curtains) in the rooms of inpatients from whom MRSA was isolated via clinical specimens. We examined the curtains within 7-14 days after they had been newly hung. The environmental surfaces were wiped using gauze (molded gauze for wiping of surface bacteria; 100% cotton, 4cm×8cm) moistened with sterile physiological saline. The MRSA contamination rate and mean counts (range) were 25.0% (6/24 samples) and 30.6 (0-255)colony-forming units (cfu)/100cm(2), respectively, for the overbed tables and 31.6% (6/19 samples) and 159.5 (0-1620)cfu/100cm(2), respectively, for the bed side rails. No MRSA was detected in 24 curtain samples. The rate of MRSA contamination of environmental surfaces was high for the overbed tables and bed side rails but low for the curtains. Therefore, at least until the 14th day of use, frequent disinfection of curtains may be not necessary. Copyright © 2016. Published by Elsevier Editora Ltda.

Concentration of airborne Staphylococcus aureus (MRSA and MSSA), total bacteria, and endotoxins in pig farms.

PubMed

Masclaux, Frederic G; Sakwinska, Olga; Charrière, Nicole; Semaani, Eulalia; Oppliger, Anne

2013-06-01

Pigs are very often colonized by Staphylococcus aureus and transmission of such pig-associated S. aureus to humans can cause serious medical, hygiene, and economic problems. The transmission route of zoonotic pathogens colonizing farm animals to humans is not well established and bioaerosols could play an important role. The aim of this study was to assess the potential occupational risk of working with S. aureus-colonized pigs in Switzerland. We estimated the airborne contamination by S. aureus in 37 pig farms (20 nursery and 17 fattening units; 25 in summer, 12 in winter). Quantification of total airborne bacterial DNA, airborne Staphylococcus sp. DNA, fungi, and airborne endotoxins was also performed. In this experiment, the presence of cultivable airborne methicillin-resistant S. aureus (MRSA) CC398 in a pig farm in Switzerland was reported for the first time. Airborne methicillin-sensitive S. aureus (MSSA) was found in ~30% of farms. The average airborne concentration of DNA copy number of total bacteria and Staphylococcus sp. measured by quantitative polymerase chain reaction was very high, respectively reaching values of 75 (± 28) × 10(7) and 35 (± 9.8) × 10(5) copy numbers m(-3) in summer and 96 (± 19) × 10(8) and 40 (± 12) × 10(6) copy numbers m(-3) in winter. Total mean airborne concentrations of endotoxins (1298 units of endotoxin m(-3)) and fungi (5707 colony-forming units m(-3)) exceeded the Swiss recommended values and were higher in winter than in summer. In conclusion, Swiss pig farmers will have to tackle a new emerging occupational risk, which could also have a strong impact on public health. The need to inform pig farmers about biological occupational risks is therefore crucial.

Pneumonia and New Methicillin-resistant Staphylococcus aureus Clone

PubMed Central

Tristan, Anne; François, Bruno; Etienne, Jerome; Delage-Corre, Manuella; Martin, Christian; Liassine, Nadia; Wannet, Wim; Denis, François; Ploy, Marie-Cécile

2006-01-01

Necrotizing pneumonia caused by Staphylococcus aureus strains carrying the Panton-Valentin leukocidin gene is a newly described disease entity. We report a new fatal case of necrotizing pneumonia. An S. aureus strain with an agr1 allele and of a new sequence type 377 was recovered, representing a new, emerging, community-acquired methicillin-resistant clone. PMID:16704793

Evaluation of Two New Chromogenic Media, CHROMagar MRSA and S. aureus ID, for Identifying Staphylococcus aureus and Screening Methicillin-Resistant S. aureus

PubMed Central

Hedin, Göran; Fang, Hong

2005-01-01

Thirty-nine methicillin-resistant Staphylococcus aureus (MRSA) isolates with diverse genetic backgrounds and two reference strains were correctly identified as S. aureus on CHROMagar MRSA and S. aureus ID media. Growth inhibition on CHROMagar MRSA was noted. A combination of cefoxitin disk and S. aureus ID was found suitable for rapid MRSA screening. PMID:16081989

Community-acquired Staphylococcus aureus bacteremia in children: a cohort study for 2010-2014.

PubMed

Pérez, Guadalupe; Martiren, Soledad; Reijtman, Vanesa; Romero, Romina; Mastroianni, Alejandra; Casimir, Lidia; Bologna, Rosa

2016-12-01

Community-acquired methicillin-resistant Staphylococcus aureus infections are a common, serious problem in pediatrics. To describe antibiotic resistance in community-acquired Staphylococcus aureus (SA) bacteremias. To compare the characteristics of SA bacteremias in terms of methicillin resistance. Prospective cohort enrolled between January 2010 and December 2014. Inclusion criteria: infants and children between 30 days old and 16 years old hospitalized at the Hospital de Pediatria J. P. Garrahan due to community-acquired infections with SA growth identification in blood cultures. Exclusion criteria: having a history of recent hospitalization, attending a health care facility, living in a closed community, or having a venous catheter. Microbiological, demographic, and clinical characteristics were compared in terms of methicillin susceptibility. Statistical analysis: Stata10. A total of 208 children were included; boys: 141 (68%). Their median age was 60 months old (interquartile range: 29-130). Thirty-four patients (16%) had an underlying disease. Methicillin-resistant Staphylococcus aureus was identified in 136 children (65%). The rate of resistance to clindamycin was 9%. Significant statistical differences were observed in the rate of underlying disease, persistent bacteremia, sepsis at the time of admission, secondary source of infection, admission to the intensive care unit, and surgery requirement. Twelve patients (6%) died; community-acquired methicillin-resistant Staphylococcus aureus was identified in all of them. In the studied cohort, methicillin-resistant S taphylococcus aureus was predominant. The rate of resistance to clindamycin was 9%. Community-acquired methicillin-resistant Staphylococcus aureus infections prevailed among healthy children. Among patients with methicillin-resistant Staphylococcus aureus infections there was a higher rate of persistent bacteremia, admission to the ICU and surgery. Sociedad Argentina de Pediatría

Staphylococcus aureus and Staphylococcus epidermidis strain diversity underlying pediatric atopic dermatitis.

PubMed

Byrd, Allyson L; Deming, Clay; Cassidy, Sara K B; Harrison, Oliver J; Ng, Weng-Ian; Conlan, Sean; Belkaid, Yasmine; Segre, Julia A; Kong, Heidi H

2017-07-05

The heterogeneous course, severity, and treatment responses among patients with atopic dermatitis (AD; eczema) highlight the complexity of this multifactorial disease. Prior studies have used traditional typing methods on cultivated isolates or sequenced a bacterial marker gene to study the skin microbial communities of AD patients. Shotgun metagenomic sequence analysis provides much greater resolution, elucidating multiple levels of microbial community assembly ranging from kingdom to species and strain-level diversification. We analyzed microbial temporal dynamics from a cohort of pediatric AD patients sampled throughout the disease course. Species-level investigation of AD flares showed greater Staphylococcus aureus predominance in patients with more severe disease and Staphylococcus epidermidis predominance in patients with less severe disease. At the strain level, metagenomic sequencing analyses demonstrated clonal S. aureus strains in more severe patients and heterogeneous S. epidermidis strain communities in all patients. To investigate strain-level biological effects of S. aureus , we topically colonized mice with human strains isolated from AD patients and controls. This cutaneous colonization model demonstrated S. aureus strain-specific differences in eliciting skin inflammation and immune signatures characteristic of AD patients. Specifically, S. aureus isolates from AD patients with more severe flares induced epidermal thickening and expansion of cutaneous T helper 2 (T H 2) and T H 17 cells. Integrating high-resolution sequencing, culturing, and animal models demonstrated how functional differences of staphylococcal strains may contribute to the complexity of AD disease. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Complete Genome Sequence of the Quality Control Strain Staphylococcus aureus subsp. aureus ATCC 25923.

PubMed

Treangen, Todd J; Maybank, Rosslyn A; Enke, Sana; Friss, Mary Beth; Diviak, Lynn F; Karaolis, David K R; Koren, Sergey; Ondov, Brian; Phillippy, Adam M; Bergman, Nicholas H; Rosovitz, M J

2014-11-06

Staphylococcus aureus subsp. aureus ATCC 25923 is commonly used as a control strain for susceptibility testing to antibiotics and as a quality control strain for commercial products. We present the completed genome sequence for the strain, consisting of the chromosome and a 27.5-kb plasmid. Copyright © 2014 Treangen et al.

An Improved Medium for Growing Staphylococcus aureus Biofilm

DTIC Science & Technology

2012-04-19

implantitis, chronic wound infections , chronic rhinosinusitis, endocarditis , and ocular infections (Archer et al., 2011). In addition, emerging evidence...causes of human bacterial infections , Staphylococcus aureus, a gram positive organism, is a ubiquitous oppor tunistic pathogen that commonly colonizes...resistant to antibiotic therapy. It has been shown that S. aureus biofilms are involved in oste omyelitis; indwelling medical device infections ; and peri

The impact of meticillin-resistant Staphylococcus aureus on patients with advanced cancer and their family members: A qualitative study.

PubMed

Gleeson, Aoife; Larkin, Philip; O'Sullivan, Niamh

2016-04-01

Little is known about the impact of meticillin-resistant Staphylococcus aureus on patients with advanced cancer, such as its impact on the quality of life of this vulnerable group. To date, research on meticillin-resistant Staphylococcus aureus in the palliative care setting has had a quantitative focus. The purpose of this study was to explore the impact of a meticillin-resistant Staphylococcus aureus diagnosis on patients and their carers. This article reports upon a qualitative interview study of nine patients with advanced cancer and meticillin-resistant Staphylococcus aureus and nine family members (n = 18). Framework analysis was used to analyse the data. Patients and family members of patients with advanced cancer either admitted to the specialist palliative care unit or receiving palliative care in the hospital setting, who had a laboratory confirmed diagnosis of meticillin-resistant Staphylococcus aureus colonisation, were considered for inclusion in the study. Four themes were identified using framework analysis: reactions to receiving a meticillin-resistant Staphylococcus aureus diagnosis, the need for effective communication of the meticillin-resistant Staphylococcus aureus diagnosis, the enigmatic nature of meticillin-resistant Staphylococcus aureus, and lessons to guide the future care of meticillin-resistant Staphylococcus aureus patients. This article indicates that meticillin-resistant Staphylococcus aureus can have a significant impact on advanced cancer patients and their families. This impact may be underestimated, but early and careful face-to-face explanation about meticillin-resistant Staphylococcus aureus and its implications can help patients and their families to cope better with it. These findings should be considered when developing policy relating to meticillin-resistant Staphylococcus aureus management and infection control in specialist palliative care settings. © The Author(s) 2015.

Staphylococcus aureus infection dynamics.

PubMed

Pollitt, Eric J G; Szkuta, Piotr T; Burns, Nicola; Foster, Simon J

2018-06-01

Staphylococcus aureus is a human commensal that can also cause systemic infections. This transition requires evasion of the immune response and the ability to exploit different niches within the host. However, the disease mechanisms and the dominant immune mediators against infection are poorly understood. Previously it has been shown that the infecting S. aureus population goes through a population bottleneck, from which very few bacteria escape to establish the abscesses that are characteristic of many infections. Here we examine the host factors underlying the population bottleneck and subsequent clonal expansion in S. aureus infection models, to identify underpinning principles of infection. The bottleneck is a common feature between models and is independent of S. aureus strain. Interestingly, the high doses of S. aureus required for the widely used "survival" model results in a reduced population bottleneck, suggesting that host defences have been simply overloaded. This brings into question the applicability of the survival model. Depletion of immune mediators revealed key breakpoints and the dynamics of systemic infection. Loss of macrophages, including the liver Kupffer cells, led to increased sensitivity to infection as expected but also loss of the population bottleneck and the spread to other organs still occurred. Conversely, neutrophil depletion led to greater susceptibility to disease but with a concomitant maintenance of the bottleneck and lack of systemic spread. We also used a novel microscopy approach to examine abscess architecture and distribution within organs. From these observations we developed a conceptual model for S. aureus disease from initial infection to mature abscess. This work highlights the need to understand the complexities of the infectious process to be able to assign functions for host and bacterial components, and why S. aureus disease requires a seemingly high infectious dose and how interventions such as a vaccine may be

Management of methicillin-resistant Staphylococcus aureus bacteremia.

PubMed

Cosgrove, Sara E; Fowler, Vance G

2008-06-01

Staphylococcus aureus bacteremia and endocarditis are serious infections that demand prompt clinical attention to ensure good outcomes. Of foremost importance is identifying and managing the source of infection and any associated complications. Evaluation for the presence of cardiac involvement is essential because inadequately managed S. aureus endocarditis is life threatening. Thus, physicians must aggressively negotiate treatment paths, considering whether the S. aureus bacteremia is complicated, whether foreign sources of infection should be removed or replaced, and whether surgical intervention is necessary. Selection of an antibiotic treatment is also an essential factor for optimal management. The increasing prevalence of methicillin-resistant S. aureus (MRSA) infections has created a tremendous demand for effective and safe antimicrobial agents other than the historic anti-MRSA agent vancomycin.

Characterization of Staphylococcus aureus isolates from retail chicken carcasses and pet workers in Northwest Arkansas.

PubMed

Hanning, Irene; Gilmore, David; Pendleton, Sean; Fleck, Scott; Clement, Ashley; Park, Si Hong; Scott, Erin; Ricke, Steven C

2012-01-01

Staphylococcus aureus can be carried on the skin and nasal passages of humans and animals as a commensal. A case of human methicillin-resistant S. aureus infection resulting from contact with pork has been reported. Poultry carcasses are sold at retail with the skin intact, but pork and beef typically are not. Thus, the risk of methicillin-resistant S. aureus human infection from whole raw poultry carcasses may be greater than that of exposure from pork or beef. The objective of this study was to isolate and characterize S. aureus from whole retail poultry carcasses and compare the isolates to S. aureus isolates from humans. A total of 25 S. aureus isolates were collected from 222 whole poultry carcasses. The isolates were characterized phenotypically with antibiotic resistance disc diffusion assays and genotypically using multilocus sequence typing. A total of 17 S. aureus isolates obtained from healthy humans were included and characterized in the same way as the poultry isolates. Staphylococcus spp. were recovered from all poultry carcasses. Only 25 poultry carcasses (11.2%) were contaminated with S. aureus. Of these 25 isolates, 36% were resistant to at least one of the antibiotics tested and 20% were resistant to two or more antibiotics tested. However, 100% of the human isolates were resistant to at least one of the antibiotics and 94% were resistant to two or more antibiotics. The results of the multilocus sequence typing indicate that most of the isolates grouped according to source. These results indicate a low prevalence of S. aureus present in poultry, and the isolates were not phenotypically similar to human isolates. The low number of S. aureus isolates from this study indicates that chicken carcasses would appear to not be a significant source of this bacterium.

Community-acquired methicillin-resistant Staphylococcus aureus: an emerging pathogen in orthopaedics.

PubMed

Marcotte, Anthony L; Trzeciak, Marc A

2008-02-01

Staphylococcus aureus (S aureus) remains one of the most common pathogens for skin and soft-tissue infections encountered by the orthopaedic surgeon. Community-acquired methicillin-resistant S aureus (CA-MRSA) has become increasingly prevalent, particularly among athletes, children in day care, homeless persons, intravenous drug users, men who have sex with men, military recruits, certain minorities (ie, Alaskan Natives, Native Americans, Pacific Islanders), and prison inmates. Risk factors include antibiotic use within the preceding year, crowded living conditions, compromised skin integrity, contaminated surfaces, frequent skin-to-skin contact, shared items, and suboptimal cleanliness. When a patient presents with a skin or soft-tissue infection, the clinician should determine whether an abscess or other infection needs to be surgically incised and drained. Cultures should be performed. When the patient is a member of an at-risk group or has any of the risk factors for CA-MRSA, beta-lactam antibiotics (eg, methicillin) are no longer a reasonable choice for treatment. Empiric treatment should consist of non-beta-lactam antibiotics active against CA-MRSA.

Prevalence and Antibiogram Assessment of Staphylococcus aureus in Beef at Municipal Abattoir and Butcher Shops in Addis Ababa, Ethiopia

PubMed Central

Adugna, Feben; Pal, Mahendra

2018-01-01

Objective A cross-sectional study was conducted from October 2013 to April 2014 to determine the prevalence and antibiotic resistance of Staphylococcus aureus from beef of Addis Ababa Abattoir and butcher shops in Addis Ababa. Seven hundred sixty-eight swab samples were taken from the abattoir and butcher carcasses using a systematic random sampling. One hundred twenty swab samples were also taken from hooks, cutting tables, and knives from the abattoir. Staphylococcus aureus positive isolates were taken for antibiotic susceptibility test. A questionnaire survey was conducted in the abattoir and butcher workers to assess the hygienic practice and possible risk factors regarding the contamination of meat. Results The prevalence of S. aureus in the abattoir, butcher, cutting table, hook, and knife was 9.4%, 19.8%, 15%, 15%, and 22.5%, respectively. The prevalence of S. aureus in the knife and butcher was found to be 2.8 (OR = 2.8, CI = 1.2–6.4) and 2.4 (OR = 2.4, CI = 1.6–3.6) times that of the abattoir results (p < 0.01). The antimicrobial susceptibility testing was also conducted on 133 isolates of S. aureus using the disc diffusion susceptibility method. Bacitracin, neomycin, and methicillin were found to be 100% resistant to S. aureus. To avoid the presence of pathogenic Staphylococcus isolates, preventive measures using good hygienic practices during slaughtering and handling of the beef carcasses are recommended. PMID:29854759

Diversity of Staphylococcus aureus Isolates in European Wildlife

PubMed Central

Monecke, Stefan; Gavier-Widén, Dolores; Hotzel, Helmut; Peters, Martin; Guenther, Sebastian; Lazaris, Alexandros; Loncaric, Igor; Müller, Elke; Reissig, Annett; Ruppelt-Lorz, Antje; Shore, Anna C.; Walter, Birgit; Coleman, David C.; Ehricht, Ralf

2016-01-01

Staphylococcus aureus is a well-known colonizer and cause of infection among animals and it has been described from numerous domestic and wild animal species. The aim of the present study was to investigate the molecular epidemiology of S. aureus in a convenience sample of European wildlife and to review what previously has been observed in the subject field. 124 S. aureus isolates were collected from wildlife in Germany, Austria and Sweden; they were characterized by DNA microarray hybridization and, for isolates with novel hybridization patterns, by multilocus sequence typing (MLST). The isolates were assigned to 29 clonal complexes and singleton sequence types (CC1, CC5, CC6, CC7, CC8, CC9, CC12, CC15, CC22, CC25, CC30, CC49, CC59, CC88, CC97, CC130, CC133, CC398, ST425, CC599, CC692, CC707, ST890, CC1956, ST2425, CC2671, ST2691, CC2767 and ST2963), some of which (ST2425, ST2691, ST2963) were not described previously. Resistance rates in wildlife strains were rather low and mecA-MRSA isolates were rare (n = 6). mecC-MRSA (n = 8) were identified from a fox, a fallow deer, hares and hedgehogs. The common cattle-associated lineages CC479 and CC705 were not detected in wildlife in the present study while, in contrast, a third common cattle lineage, CC97, was found to be common among cervids. No Staphylococcus argenteus or Staphylococcus schweitzeri-like isolates were found. Systematic studies are required to monitor the possible transmission of human- and livestock-associated S. aureus/MRSA to wildlife and vice versa as well as the possible transmission, by unprotected contact to animals. The prevalence of S. aureus/MRSA in wildlife as well as its population structures in different wildlife host species warrants further investigation. PMID:27992523

Nasal Carriage Rate of Methicillin Resistant Staphylococcus aureus among Health Care Workers at a Tertiary Care Hospital in Kathmandu, Nepal.

PubMed

Khatri, S; Pant, N D; Bhandari, R; Shrestha, K L; Shrestha, C D; Adhikari, N; Poudel, A

2017-01-01

Methicillin-resistant Staphylococcus aureus is one of the most common causes of nosocomial infections. Due to its multidrug resistant nature; infections due to Methicillin-resistant Staphylococcus aureus are often very difficult to treat. Colonized health care workers are the important sources of Methicillin-resistant Staphylococcus aureus. The objectives of this study were to determine the nasal carriage rate of Methicillin-resistant Staphylococcus aureus among health care workers at Kathmandu Medical College and Teaching Hospital, Nepal and to assess their antimicrobial susceptibility patterns. A cross sectional study was conducted among 252 health care workers from July to November 2013. Mannitol salt agar was used to culture the nasal swabs. Antimicrobial susceptibility testing was performed by Kirby-Bauer disc diffusion technique following Clinical and Laboratory Standards Institute guidelines. Methicillin-resistant Staphylococcus aureus strains were confirmed by using cefoxitin disc and by determining the minimum inhibitory concentration of oxacillin by agar dilution method. Of 252 healthcare workers, 46(18.3%) were positive for Staphylococcus aureus among which 19(41.3%) were Methicillin-resistant Staphylococcus aureus carriers. Overall rate of nasal carriage of Methicillin-resistant Staphylococcus aureus was 7.5% (19/252).The higher percentages of lab personnel were nasal carriers of S. aureus (31.6%) and Methicillin-resistant Staphylococcus aureus (10.5%).The percentages of nasal carriage of S. aureus (35.7%) and Methicillin-resistant Staphylococcus aureus (14.3%) were highest in the health care workers from post operative department. Higher percentage of Methicillin-resistant Staphylococcus aureus were susceptible toward amikacin (100%) and vancomycin (100%) followed by cotrimoxazole (84.2%). High rates of nasal carriage of S. aureus and Methicillin-resistant Staphylococcus aureus were observed among the healthcare workers, which indicate the need of

Sensory deprivation in Staphylococcus aureus.

PubMed

Villanueva, Maite; García, Begoña; Valle, Jaione; Rapún, Beatriz; Ruiz de Los Mozos, Igor; Solano, Cristina; Martí, Miguel; Penadés, José R; Toledo-Arana, Alejandro; Lasa, Iñigo

2018-02-06

Bacteria use two-component systems (TCSs) to sense and respond to environmental changes. The core genome of the major human pathogen Staphylococcus aureus encodes 16 TCSs, one of which (WalRK) is essential. Here we show that S. aureus can be deprived of its complete sensorial TCS network and still survive under growth arrest conditions similarly to wild-type bacteria. Under replicating conditions, however, the WalRK system is necessary and sufficient to maintain bacterial growth, indicating that sensing through TCSs is mostly dispensable for living under constant environmental conditions. Characterization of S. aureus derivatives containing individual TCSs reveals that each TCS appears to be autonomous and self-sufficient to sense and respond to specific environmental cues, although some level of cross-regulation between non-cognate sensor-response regulator pairs occurs in vivo. This organization, if confirmed in other bacterial species, may provide a general evolutionarily mechanism for flexible bacterial adaptation to life in new niches.

Methicillin-Resistant Staphylococcus aureus (MRSA) Infections in the Department of Defense (DOD): Annual Summary Report 2014

DTIC Science & Technology

2015-10-01

NAVY AND MARINE CORPS PUBUC IEAI.TI CINTIR PREVENTION AND PROTECTION START HERE Methicillin-Resistant Staphylococcus aureus IMRSAJ Infections in...Methicit li~esistant Staphylococcus aureus (MRSA) Infections in the Department of Defense (000): Annual Summary Report 2014 Jessica Spencer. Uzo...Distribution is not limited. NUMBER NMCPHC-EOC-TR-499-2015 NUMBER($) NMCPHC-EDC-TR-499-201 5 Metticitrin-resistant Staphylococcus aureus (MRSA

Performance of CHROMagar MRSA Medium for Detection of Methicillin-Resistant Staphylococcus aureus

PubMed Central

Diederen, Bram; van Duijn, Inge; van Belkum, Alex; Willemse, Piet; van Keulen, Peter; Kluytmans, Jan

2005-01-01

CHROMagar MRSA was evaluated for its ability to identify methicillin-resistant Staphylococcus aureus (MRSA). A well-defined collection consisting of 216 MRSA strains and 241 methicillin-susceptible Staphylococcus aureus isolates was used. The sensitivity of CHROMagar MRSA after 24 h of incubation was 95.4%, increasing to 100% after 48 h. The specificity was already 100% after 24 h. PMID:15815020

Antimicrobial effect of Dinoponera quadriceps (Hymenoptera: Formicidae) venom against Staphylococcus aureus strains.

PubMed

Lima, D B; Torres, A F C; Mello, C P; de Menezes, R R P P B; Sampaio, T L; Canuto, J A; da Silva, J J A; Freire, V N; Quinet, Y P; Havt, A; Monteiro, H S A; Nogueira, N A P; Martins, A M C

2014-08-01

Dinoponera quadriceps venom (DqV) was examined to evaluate the antibacterial activity and its bactericidal action mechanism against Staphylococcus aureus. DqV was tested against a standard strain of methicillin-sensitive Staphylococcus aureus (MSSA), Staph. aureus ATCC 6538P and two standard strains of methicillin-resistant Staphylococcus aureus (MRSA), Staph. aureus ATCC 33591 and Staph. aureus CCBH 5330. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), the rate of kill and pH sensitivity of the DqV were determined by microdilution tests. Bactericidal and inhibitory concentrations of DqV were tested to check its action on Staph. aureus membrane permeability and cell morphology. The MIC and MBC of DqV were 6·25 and 12·5 μg ml(-1) for Staph. aureus ATCC 6538P, 12·5 and 50 μg ml(-1) for Staph. aureus CCBH 5330 and 100 and 100 μg ml(-1) for Staph. aureus ATCC 33591, respectively. Complete bacterial growth inhibition was observed after 4 h of incubation with the MBC of DqV. A lowest MIC was observed in alkaline pH. Alteration in membrane permeability was observed through the increase in crystal violet uptake, genetic material release and morphology in atomic force microscopy. The results suggest antibacterial activity of DqV against Staph. aureus and that the venom acts in the cell membrane. Alteration in membrane permeability may be associated with the antimicrobial activity of hymenopteran venoms. © 2014 The Society for Applied Microbiology.

Tolerance of Salmonella Enteritidis and Staphylococcus aureus to surface cleaning and household bleach.

PubMed

Kusumaningrum, H D; Paltinaite, R; Koomen, A J; Hazeleger, W C; Rombouts, F M; Beumer, R R

2003-12-01

Effective cleaning and sanitizing of food preparation sites is important because pathogens are readily spread to food contact surfaces after preparation of contaminated raw products. Tolerance of Salmonella Enteritidis and Staphylococcus aureus to surface cleaning by wiping with regular, microfiber, and antibacterial-treated cloths was investigated. Wiping with cleaning cloths resulted in a considerable reduction of microorganisms from surfaces, despite the greater difficulty in removing S. aureus than Salmonella Enteritidis. Depending on the cloth type, S. aureus were reduced on surfaces from initial numbers of approximately 10(5) CFU/100 cm2 to numbers from less than 4 CFU/100 cm2 (below the detection limit) to 100 CFU/100 cm2. Directly after the cloths were used to clean the contaminated surfaces, they contained high numbers of bacteria (10(4) to 10(5) CFU/100 cm2), except for the disposable antibacterial-treated cloths, in which no bacteria could be detected. The tolerance of these pathogens to sodium hypochlorite was studied in the suspension test and in cloths. S. aureus showed a better tolerance for sodium hypochlorite than Salmonella Enteritidis. Inactivation of microorganisms in cloths required a higher concentration of sodium hypochlorite than was needed in the suspension test. Repeated exposure to sodium hypochlorite, however, resulted in an increase in susceptibility to this compound. This study provides essential information about the transfer of bacteria when wiping surfaces and highlights the need for a hygiene procedure with cleaning cloths that sufficiently avoids cross-contamination in the household environment.

Magnetic nanoparticle targeted hyperthermia of cutaneous Staphylococcus aureus infection

PubMed Central

Kim, Min-Ho; Yamayoshi, Itsukyo; Mathew, Steven; Liln, Hubert; Nayfach, Joseph; Simon, Scott I.

2013-01-01

The incidence of wound infections that do not adequately respond to standard-of-care antimicrobial treatment has been increasing. To address this challenge, a novel antimicrobial magnetic thermotherapy platform has been developed in which a high-amplitude, high-frequency, alternating magnetic field (AMF) is used to rapidly heat magnetic nanoparticles that are bound to Staphylococcus aureus (S. aureus). The antimicrobial efficacy of this platform was evaluated in the treatment of both an in vitro culture model of S. aureus biofilm and a mouse model of cutaneous S. aureus infection. We demonstrated that an antibody-targeted magnetic nanoparticle bound to S. aureus was effective at thermally inactivating S. aureus and achieving accelerated wound healing without causing tissue injury. PMID:23149904

Preparation of 8-hydroxyquinoline derivatives as potential antibiotics against Staphylococcus aureus.

PubMed

Lam, Kim-Hung; Gambari, Roberto; Lee, Kenneth Ka-Ho; Chen, Yi-Xin; Kok, Stanton Hon-Lung; Wong, Raymond Siu-Ming; Lau, Fung-Yi; Cheng, Chor-Hing; Wong, Wai-Yeung; Bian, Zhao-Xiang; Chan, Albert Sun-Chi; Tang, Johnny Cheuk-On; Chui, Chung-Hin

2014-01-01

This work describes the preparation of quinoline compounds as possible anti-bacterial agents. The synthesized quinoline derivatives show anti-bacterial activity towards Staphylococcus aureus. It is interesting to observe that the synthetic 5,7-dibromo-2-methylquinolin-8-ol (4) shows a similar minimum inhibitory concentration of 6.25μg/mL as compared to that of methicillin (3.125μg/mL) against Staphylococcus aureus. Copyright © 2013 Elsevier Ltd. All rights reserved.

Biosensors for rapid and sensitive detection of Staphylococcus aureus in food.

PubMed

Rubab, Momna; Shahbaz, Hafiz Muhammad; Olaimat, Amin N; Oh, Deog-Hwan

2018-05-15

Foodborne illness outbreaks caused by the consumption of food contaminated with harmful bacteria has drastically increased in the past decades. Therefore, detection of harmful bacteria in the food has become an important factor for the recognition and prevention of problems associated with food safety and public health. Staphylococcus aureus is one of the most commonly isolated foodborne pathogen and it is considered as a major cause of foodborne illnesses worldwide. A number of different methods have been developed for the detection and identification of S. aureus in food samples. However, some of these methods are laborious and time-consuming and are not suitable for on-site applications. Therefore, it is highly important to develop rapid and more approachable detection methods. In the last decade, biosensors have gained popularity as an attractive alternative method and now considered as one of most rapid and on-site applicable methods. An overview of the biosensor based methods used for the detection of S. aureus is presented herein. This review focuses on the state-of-the-art biosensor methods towards the detection and quantification of S. aureus, and discusses the most commonly used biosensor methods based on the transducing mode, such as electrochemical, optical, and mass-based biosensors. Copyright © 2018 Elsevier B.V. All rights reserved.

The T Cell Response to Staphylococcus aureus

PubMed Central

Bröker, Barbara M.; Mrochen, Daniel; Péton, Vincent

2016-01-01

Staphylococcus aureus (S. aureus) is a dangerous pathogen and a leading cause of both nosocomial and community acquired bacterial infection worldwide. However, on the other hand, we are all exposed to this bacterium, often within the first hours of life, and usually manage to establish equilibrium and coexist with it. What does the adaptive immune system contribute toward lifelong control of S. aureus? Will it become possible to raise or enhance protective immune memory by vaccination? While in the past the S. aureus-specific antibody response has dominated this discussion, the research community is now coming to appreciate the role that the cellular arm of adaptive immunity, the T cells, plays. There are numerous T cell subsets, each with differing functions, which together have the ability to orchestrate the immune response to S. aureus and hence to tip the balance between protection and pathology. This review summarizes the state of the art in this dynamic field of research. PMID:26999219

Community-acquired methicillin-resistant Staphylococcus aureus: an emerging cause of acute bacterial parotitis.

PubMed

Nicolasora, Nelson P; Zacharek, Mark A; Malani, Anurag N

2009-02-01

Staphylococcus aureus has long been recognized as a cause of acute bacterial parotitis. A case of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) parotitis is presented, highlighting the emergence of this increasingly important pathogen to cause a wide variety of infections. Also reviewed are the salient clinical and microbiologic features of this novel infection.

[Sepsis with Staphylococcus aureus in immunocompromised patients].

PubMed

Petrache, Simona Magdalena; Miftode, Egidia; Vâţă, A; Petrovici, Cristina Mirela; Dorneanu, Olivia; Luca, V

2009-01-01

The aim of our study was to analyze clinical and biological characteristics of immunocompromised patients with staphylococcal sepsis and to compare with the same data in non-immunocompromised patients. The diagnosis of sepsis was made based on Bone criteria. MiniAPI system ID 32 STAPH was used for identification and antibiotic susceptibility was assessed by ATB STAPH method and by E-test for oxacillin and vancomycin. Among the 147 patients with Staphylococcus aureus sepsis--66.67% had concomitant immunosuppressive conditions (diabetes mellitus, liver diseases, renal failure, corticotherapy, etc). We have found a significant correlation between the immunosuppressed status and MRSA (methicillin-resistant Staphylococcus aureus) involvement (p = 0.0018) and also, between this group of patients and treatment failure (p = 0.0012). Because of the high rate of MRSA involvement in systemic infections in the Eastern region of Romania first intention treatment of patients with staphylococcal infections and conditions of immunosuppression must include antibiotics effective against methicillin-resistant strains.

Genome Sequences of Four Staphylococcus aureus Strains Isolated from Bovine Mastitis

PubMed Central

Taponen, Suvi; Koort, Joanna; Paulin, Lars; Åvall-Jääskeläinen, Silja

2015-01-01

Staphylococcus aureus is a major causative agent of mastitis in dairy cows. The pathogenicity of S. aureus may vary; it is able to cause severe clinical mastitis, but most often it is associated with chronic subclinical mastitis. Here, we present the genome assemblies of four S. aureus strains from bovine mastitis. PMID:25908141

Staphylococcus aureus Strain Newman Photoinactivation and Cellular Response to Sunlight Exposure.

PubMed

McClary, Jill S; Sassoubre, Lauren M; Boehm, Alexandria B

2017-09-01

Sunlight influences microbial water quality of surface waters. Previous studies have investigated photoinactivation mechanisms and cellular photostress responses of fecal indicator bacteria (FIB), including Escherichia coli and enterococci, but further work is needed to characterize photostress responses of bacterial pathogens. Here we investigate the photoinactivation of Staphylococcus aureus (strain Newman), a pigmented, waterborne pathogen of emerging concern. We measured photodecay using standard culture-based assays and cellular membrane integrity and investigated photostress response by measuring the relative number of mRNA transcripts of select oxidative stress, DNA repair, and metabolism genes. Photoinactivation experiments were performed in both oxic and anoxic systems to further investigate the role of oxygen-mediated and non-oxygen-mediated photoinactivation mechanisms. S. aureus lost culturability much faster in oxic systems than in anoxic systems, indicating an important role for oxygen in photodecay mechanisms. S. aureus cell membranes were damaged by sunlight exposure in anoxic systems but not in oxic systems, as measured by cell membrane permeability to propidium iodide. After sunlight exposure, S. aureus increased expression of a gene coding for methionine sulfoxide reductase after 12 h of sunlight exposure in the oxic system and after 6 h of sunlight exposure in the anoxic system, suggesting that methionine sulfoxide reductase is an important enzyme for defense against both oxygen-dependent and oxygen-independent photostresses. This research highlights the importance of oxygen in bacterial photoinactivation in environmentally relevant systems and the complexity of the bacterial photostress response with respect to cell structure and transcriptional regulation. IMPORTANCE Staphylococcus aureus is a pathogenic bacterium that causes gastrointestinal, respiratory, and skin infections. In severe cases, S. aureus infection can lead to life

New antimicrobial combinations: substituted chalcones- oxacillin against methicillin resistant Staphylococcus aureus.

PubMed

Talia, Juan Manuel; Debattista, Nora Beatriz; Pappano, Nora Beatriz

2011-04-01

Staphylococcus aureus, the most virulent Staphylococcus species, is also the prevalent pathogen isolated from hospitalized patients and the second most common from patients in outpatient settings. In general, bacteria have the genetic ability to transmit and acquire resistance to drugs, which are utilized as therapeutic agents. Related studies of antimicrobial activity indicate that crude extracts containing flavonoids, triterpenes and steroids have showed significative activity against several Staphylococcus aureus strains. Combination effects between flavonoids and antibiotics also have been reported. The aim of the present work was to investigate in vitro synergism between several chalcones substituted in combination with oxacillin, an antibiotic used conventionally against S. aureus ATCC 43 300 that is resistant to meticillin, using the kinetic turbidimetric method developed earlier. The results were satisfactory for all assayed combinations and in accordance with the mechanism of bacteriostatic inhibition previously proposed, except for 2´,4´-dihydroxy-3´-methoxychalcone - oxacillin. The best combination was 2´,3´-dihydroxychalcone -oxacillin (MIC: 11.2 µg/mL). Further investigations are needed to characterize the interaction mechanism with antibiotics. Thus, chalcones - oxacillin combination could lead to the development of new antibiotics against methicillin resistant S. aureus infection.

Community-associated methicillin-resistant Staphylococcus aureus causing chronic pneumonia.

PubMed

Enayet, Iram; Nazeri, Ali; Johnson, Leonard B; Riederer, Kathleen; Pawlak, Joan; Saravolatz, Louis D

2006-04-01

A young woman presented with pneumonia of a 3-month duration with predominantly nodular pulmonary infiltrates. Methicillin-resistant Staphylococcus aureus was identified in multiple cultures of sputum specimens. According to findings of pulsed-field gel electrophoresis, the isolate was identical to USA 300 and carried a type IV Staphylococcus cassette chromosome mec type IV gene and the genes for Panton-Valentine leukocidin.

Lucky number seven: RNase 7 can prevent Staphylococcus aureus skin colonization.

PubMed

Cho, John S; Xuan, Caiyun; Miller, Lloyd S

2010-12-01

Staphylococcus aureus colonization is a major risk factor for infection. In this issue, Simanski et al. demonstrate that the antimicrobial peptide RNase 7 is essential for preventing S. aureus colonization in human skin. These findings suggest that therapeutic interventions aimed at targeting RNase 7 production in the skin may be a novel strategy to protect against S. aureus infections.

SAMMD: Staphylococcus aureus microarray meta-database.

PubMed

Nagarajan, Vijayaraj; Elasri, Mohamed O

2007-10-02

Staphylococcus aureus is an important human pathogen, causing a wide variety of diseases ranging from superficial skin infections to severe life threatening infections. S. aureus is one of the leading causes of nosocomial infections. Its ability to resist multiple antibiotics poses a growing public health problem. In order to understand the mechanism of pathogenesis of S. aureus, several global expression profiles have been developed. These transcriptional profiles included regulatory mutants of S. aureus and growth of wild type under different growth conditions. The abundance of these profiles has generated a large amount of data without a uniform annotation system to comprehensively examine them. We report the development of the Staphylococcus aureus Microarray meta-database (SAMMD) which includes data from all the published transcriptional profiles. SAMMD is a web-accessible database that helps users to perform a variety of analysis against and within the existing transcriptional profiles. SAMMD is a relational database that uses MySQL as the back end and PHP/JavaScript/DHTML as the front end. The database is normalized and consists of five tables, which holds information about gene annotations, regulated gene lists, experimental details, references, and other details. SAMMD data is collected from the peer-reviewed published articles. Data extraction and conversion was done using perl scripts while data entry was done through phpMyAdmin tool. The database is accessible via a web interface that contains several features such as a simple search by ORF ID, gene name, gene product name, advanced search using gene lists, comparing among datasets, browsing, downloading, statistics, and help. The database is licensed under General Public License (GPL). SAMMD is hosted and available at http://www.bioinformatics.org/sammd/. Currently there are over 9500 entries for regulated genes, from 67 microarray experiments. SAMMD will help staphylococcal scientists to analyze their

SAMMD: Staphylococcus aureus Microarray Meta-Database

PubMed Central

Nagarajan, Vijayaraj; Elasri, Mohamed O

2007-01-01

Background Staphylococcus aureus is an important human pathogen, causing a wide variety of diseases ranging from superficial skin infections to severe life threatening infections. S. aureus is one of the leading causes of nosocomial infections. Its ability to resist multiple antibiotics poses a growing public health problem. In order to understand the mechanism of pathogenesis of S. aureus, several global expression profiles have been developed. These transcriptional profiles included regulatory mutants of S. aureus and growth of wild type under different growth conditions. The abundance of these profiles has generated a large amount of data without a uniform annotation system to comprehensively examine them. We report the development of the Staphylococcus aureus Microarray meta-database (SAMMD) which includes data from all the published transcriptional profiles. SAMMD is a web-accessible database that helps users to perform a variety of analysis against and within the existing transcriptional profiles. Description SAMMD is a relational database that uses MySQL as the back end and PHP/JavaScript/DHTML as the front end. The database is normalized and consists of five tables, which holds information about gene annotations, regulated gene lists, experimental details, references, and other details. SAMMD data is collected from the peer-reviewed published articles. Data extraction and conversion was done using perl scripts while data entry was done through phpMyAdmin tool. The database is accessible via a web interface that contains several features such as a simple search by ORF ID, gene name, gene product name, advanced search using gene lists, comparing among datasets, browsing, downloading, statistics, and help. The database is licensed under General Public License (GPL). Conclusion SAMMD is hosted and available at . Currently there are over 9500 entries for regulated genes, from 67 microarray experiments. SAMMD will help staphylococcal scientists to analyze their

Intracellular staphylococcus aureus: Live-in and let die

PubMed Central

Fraunholz, Martin; Sinha, Bhanu

2012-01-01

Staphylococcus aureus uses a plethora of virulence factors to accommodate a diversity of niches in its human host. Aside from the classical manifestations of S. aureus-induced diseases, the pathogen also invades and survives within mammalian host cells.The survival strategies of the pathogen are as diverse as strains or host cell types used. S. aureus is able to replicate in the phagosome or freely in the cytoplasm of its host cells. It escapes the phagosome of professional and non-professional phagocytes, subverts autophagy, induces cell death mechanisms such as apoptosis and pyronecrosis, and even can induce anti-apoptotic programs in phagocytes. The focus of this review is to present a guide to recent research outlining the variety of intracellular fates of S. aureus. PMID:22919634

Changes of Antimicrobial Resistance among Staphylococcus Aureus Isolated in 8 Consecutive Years in the First Bethune Hospital

NASA Astrophysics Data System (ADS)

Xu, Wei; Zhou, Qi; Yang, Chunguang; Yao, Hanxin; Xu, Jiancheng

This study was to investigate the antimicrobial resistance of Staphylococcus aureus isolated in 8 consecutive years in the First Bethune Hospital. Disk diffusion test was used to study the antimicrobial resistance. The data were analyzed by WHONET 5 software according to Clinical and Laboratory Standards Institute (CLSI). Most of 1469 strains of Staphylococcus aureus were collected from sputum 705 (18.0%), secretions 206 (14.0%), pus 177 (12.0%) during the past 8 years. The rates of methicillin-resistant Staphylococcus aureus (MRSA) were between 50.8% and 83.3% during the past 8 years, respectively. In recent 8 years, the antimicrobial resistance of Staphylococcus aureus had increased. Monitoring the antimicrobial resistance to Staphylococcus aureus should be strengthened. The change of the antimicrobial resistance should be investigated in order to direct rational drug usage in the clinic and prevent bacterial strain of drug resistance from being transmitted.

Antimicrobial resistance of Staphylococcus aureus isolates from dairy cows and genetic diversity of resistant isolates

USDA-ARS?s Scientific Manuscript database

Staphylococcus aureus is a frequent and major contagious mastitis bacterial pathogen. The antibiotic treatment cure rates vary considerably from 4% to 92%. Staphylococcus aureus readily becomes resistant to antibiotics, resulting in persistent noncurable intramammary infection that usually results i...

Methicillin-resistant Staphylococcus aureus in a neonatal alpaca

PubMed Central

Stull, Jason W.; Kenney, Daniel G.; Slavić, Durda; Weese, J. Scott

2012-01-01

A 6-hour-old alpaca was presented for evaluation of respiratory difficulty. As part of routine surveillance, methicillin-resistant Staphylococcus aureus (MRSA) was identified from a nasal swab taken upon admission to the hospital. No signs of MRSA infection were noted. The MRSA strain recovered was a human epidemic clone that has been associated with horses. Methicillin-resistant S. aureus colonization can occur in camelids, and the potential animal and public health risks require consideration. PMID:23204589

Mobile genetic elements of Staphylococcus aureus.

PubMed

Malachowa, Natalia; DeLeo, Frank R

2010-09-01

Bacteria such as Staphylococcus aureus are successful as commensal organisms or pathogens in part because they adapt rapidly to selective pressures imparted by the human host. Mobile genetic elements (MGEs) play a central role in this adaptation process and are a means to transfer genetic information (DNA) among and within bacterial species. Importantly, MGEs encode putative virulence factors and molecules that confer resistance to antibiotics, including the gene that confers resistance to beta-lactam antibiotics in methicillin-resistant S. aureus (MRSA). Inasmuch as MRSA infections are a significant problem worldwide and continue to emerge in epidemic waves, there has been significant effort to improve diagnostic assays and to develop new antimicrobial agents for treatment of disease. Our understanding of S. aureus MGEs and the molecules they encode has played an important role toward these ends and has provided detailed insight into the evolution of antimicrobial resistance mechanisms and virulence.

Self-sampling is appropriate for detection of Staphylococcus aureus: a validation study

PubMed Central

2012-01-01

Background Studies frequently use nasal swabs to determine Staphylococcus aureus carriage. Self-sampling would be extremely useful in an outhospital research situation, but has not been studied in a healthy population. We studied the similarity of self-samples and investigator-samples in nares and pharynxes of healthy study subjects (hospital staff) in the Netherlands. Methods One hundred and five nursing personnel members were sampled 4 times in random order after viewing an instruction paper: 1) nasal self-sample, 2) pharyngeal self-sample, 3) nasal investigator-sample, and 4) pharyngeal investigator-sample. Results For nasal samples, agreement is 93% with a kappa coefficient of 0.85 (95% CI 0.74-0.96), indicating excellent agreement, for pharyngeal samples agreement is 83% and the kappa coefficient is 0.60 (95% CI 0.43-0.76), indicating good agreement. In both sampling sites self-samples even detected more S. aureus than investigator-samples. Conclusions This means that self-samples are appropriate for detection of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus. PMID:23137281

Staphylococcus aureus, phagocyte NADPH oxidase and chronic granulomatous disease.

PubMed

Buvelot, Helene; Posfay-Barbe, Klara M; Linder, Patrick; Schrenzel, Jacques; Krause, Karl-Heinz

2017-03-01

Dysfunction of phagocytes is a relevant risk factor for staphylococcal infection. The most common hereditary phagocyte dysfunction is chronic granulomatous disease (CGD), characterized by impaired generation of reactive oxygen species (ROS) due to loss of function mutations within the phagocyte NADPH oxidase NOX2. Phagocytes ROS generation is fundamental to eliminate pathogens and to regulate the inflammatory response to infection. CGD is characterized by recurrent and severe bacterial and fungal infections, with Staphylococcus aureus as the most frequent pathogen, and skin and lung abscesses as the most common clinical entities. Staphylococcus aureus infection may occur in virtually any human host, presumably because of the many virulence factors of the bacterium. However, in the presence of functional NOX2, staphylococcal infections remain rare and are mainly linked to breaches of the skin barrier. In contrast, in patients with CGD, S. aureus readily survives and frequently causes clinically apparent disease. Astonishingly, little is known why S. aureus, which possesses a wide range of antioxidant enzymes (e.g. catalase, SOD), is particularly sensitive to control through NOX2. In this review, we will evaluate the discovery of CGD and our present knowledge of the role of NOX2 in S. aureus infection. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Quantitation of Staphylococcus aureus in Seawater Using CHROMagar™ SA

PubMed Central

Pombo, David; Hui, Jennifer; Kurano, Michelle; Bankowski, Matthew J; Seifried, Steven E

2010-01-01

A microbiological algorithm has been developed to analyze beach water samples for the determination of viable colony forming units (CFU) of Staphylococcus aureus (S. aureus). Membrane filtration enumeration of S. aureus from recreational beach waters using the chromogenic media CHROMagar™SA alone yields a positive predictive value (PPV) of 70%. Presumptive CHROMagar™SA colonies were confirmed as S. aureus by 24-hour tube coagulase test. Combined, these two tests yield a PPV of 100%. This algorithm enables accurate quantitation of S. aureus in seawater in 72 hours and could support risk-prediction processes for recreational waters. A more rapid protocol, utilizing a 4-hour tube coagulase confirmatory test, enables a 48-hour turnaround time with a modest false negative rate of less than 10%. PMID:20222490

Double triplex real-time PCR assay for simultaneous detection of Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus hominis, and Staphylococcus haemolyticus and determination of their methicillin resistance directly from positive blood culture bottles.

PubMed

Kilic, Abdullah; Basustaoglu, A Celal

2011-12-01

We developed and validated here a double triplex real-time PCR assay to simultaneously detect and identify Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus hominis, Staphylococcus haemolyticus and their methicillin resistance in a single reaction directly from Gram-positive cocci-in-clusters (GPCs)-positive blood culture bottles. From August 15, 2009 through February 15, 2010, 238 GPC-positive samples were collected and identified by conventional methods as 11 methicillin-resistant S. aureus (MRSA), 28 methicillin-susceptible S. aureus (MSSA), 176 MR coagulase-negative staphylococci (MRCoNS), 21 MSCoNS and two Enterococcus faecalis. The double triplex real-time PCR assay was targeted and detected tuf, nuc and mecA genes in the first tube and atlE, gap and mvaA genes in the second tube which could be run simultaneously. The detection limit of the assay was found at 10(3) CFU/ml for the atleE gene, 10(4) CFU/ml for the mva gene and 10(5) CFU/ml for gap, nuc, mecA and tuf genes based on seeding experiments. All Staphylococcus species except two S. epidermidis were correctly identified by the assay. The double triplex real-time PCR assay quickly and accurately detects S. aureus, S. epidermidis, S. hominis and S. haemolyticus and their methicillin resistance in a single reaction directly from positive blood culture bottles within 83 min. Copyright © 2011 Institut Pasteur. All rights reserved.

Noncontiguous Finished Genome Sequence of Staphylococcus aureus KLT6, a Staphylococcal Enterotoxin B-Positive Strain Involved in a Food Poisoning Outbreak in Switzerland

PubMed Central

Tobes, Raquel; Manrique, Marina; Brozynska, Marta; Stephan, Roger; Pareja, Eduardo

2013-01-01

We present the first complete genome sequence of a Staphylococcus aureus strain assigned to clonal complex 12. The strain was isolated in a food poisoning outbreak due to contaminated potato salad in Switzerland in 2009, and it produces staphylococcal enterotoxin B. PMID:23704175

Staphylococcus aureus pathogenesis in diverse host environments

PubMed Central

Balasubramanian, Divya; Harper, Lamia; Shopsin, Bo; Torres, Victor J.

2017-01-01

Abstract Staphylococcus aureus is an eminent human pathogen that can colonize the human host and cause severe life-threatening illnesses. This bacterium can reside in and infect a wide range of host tissues, ranging from superficial surfaces like the skin to deeper tissues such as in the gastrointestinal tract, heart and bones. Due to its multifaceted lifestyle, S. aureus uses complex regulatory networks to sense diverse signals that enable it to adapt to different environments and modulate virulence. In this minireview, we explore well-characterized environmental and host cues that S. aureus responds to and describe how this pathogen modulates virulence in response to these signals. Lastly, we highlight therapeutic approaches undertaken by several groups to inhibit both signaling and the cognate regulators that sense and transmit these signals downstream. PMID:28104617

New antimicrobial combinations: substituted chalcones- oxacillin against methicillin resistant Staphylococcus aureus

PubMed Central

Talia, Juan Manuel; Debattista, Nora Beatriz; Pappano, Nora Beatriz

2011-01-01

Staphylococcus aureus, the most virulent Staphylococcus species, is also the prevalent pathogen isolated from hospitalized patients and the second most common from patients in outpatient settings. In general, bacteria have the genetic ability to transmit and acquire resistance to drugs, which are utilized as therapeutic agents. Related studies of antimicrobial activity indicate that crude extracts containing flavonoids, triterpenes and steroids have showed significative activity against several Staphylococcus aureus strains. Combination effects between flavonoids and antibiotics also have been reported. The aim of the present work was to investigate in vitro synergism between several chalcones substituted in combination with oxacillin, an antibiotic used conventionally against S. aureus ATCC 43 300 that is resistant to meticillin, using the kinetic turbidimetric method developed earlier. The results were satisfactory for all assayed combinations and in accordance with the mechanism of bacteriostatic inhibition previously proposed, except for 2´,4´-dihydroxy-3´-methoxychalcone – oxacillin. The best combination was 2´,3´-dihydroxychalcone -oxacillin (MIC: 11.2 µg/mL). Further investigations are needed to characterize the interaction mechanism with antibiotics. Thus, chalcones – oxacillin combination could lead to the development of new antibiotics against methicillin resistant S. aureus infection. PMID:24031657

Pathogenesis of Staphylococcus aureus Bloodstream Infections

PubMed Central

Thomer, Lena; Schneewind, Olaf; Missiakas, Dominique

2016-01-01

Staphylococcus aureus , a Gram-positive bacterium colonizing nares, skin, and the gastrointestinal tract, frequently invades the skin, soft tissues, and bloodstreams of humans. Even with surgical and antibiotic therapy, bloodstream infections are associated with significant mortality. The secretion of coagulases, proteins that associate with and activate the host hemostatic factor prothrombin, and the bacterial surface display of agglutinins, proteins that bind polymerized fibrin, are key virulence strategies for the pathogenesis of S. aureus bloodstream infections, which culminate in the establishment of abscess lesions. Pathogen-controlled processes, involving a wide spectrum of secreted factors, are responsible for the recruitment and destruction of immune cells, transforming abscess lesions into purulent exudate, with which staphylococci disseminate to produce new infectious lesions or to infect new hosts. Research on S. aureus bloodstream infections is a frontier for the characterization of protective vaccine antigens and the development of immune therapeutics aiming to prevent disease or improve outcomes. PMID:26925499

Global Transcriptome Analysis of Staphylococcus aureus Response to Hydrogen Peroxide†

PubMed Central

Chang, Wook; Small, David A.; Toghrol, Freshteh; Bentley, William E.

2006-01-01

Staphylococcus aureus responds with protective strategies against phagocyte-derived reactive oxidants to infect humans. Herein, we report the transcriptome analysis of the cellular response of S. aureus to hydrogen peroxide-induced oxidative stress. The data indicate that the oxidative response includes the induction of genes involved in virulence, DNA repair, and notably, anaerobic metabolism. PMID:16452450

Phenotypic and genotypic antimicrobial resistance traits of foodborne Staphylococcus aureus isolates from Shanghai

USDA-ARS?s Scientific Manuscript database

Staphylococcus aureus is a recognized pathogen in humans, which causes nosocomial infections and food poisoning. The transmission of antibiotic resistant S. aureus (ARSA), especially methicillin-resistant S. aureus (MRSA), between food products and humans has become a serious problem. Hence, it is n...

Triple-acting antimicrobial treatment for drug-resistant and intracellular Staphylococcus aureus

USDA-ARS?s Scientific Manuscript database

Multi-drug resistant bacteria are a persistent problem in modern health care, food safety and animal health. There is a need for new antimicrobials to replace over-used conventional antibiotics. Staphylococcus aureus (S. aureus) is a notorious pathogen for both animal and human health with multi-d...

Triple-acting antimicrobial treatment for drug-resistant and intracellular Staphylococcus aureus.

USDA-ARS?s Scientific Manuscript database

Multi-drug resistant bacteria are a persistent problem in modern health care, food safety and animal health. There is a need for new antimicrobials to replace over-used conventional antibiotics. Staphylococcus aureus (S. aureus) is a notorious pathogen for both animal and human health with multi-d...

Rapid Detection of Methicillin-Resistant Staphylococcus aureus Isolates by Turanose Fermentation Method

PubMed Central

Raeisi, Javad; Saifi, Mahnaz; Pourshafie, Mohammad Reza; Asadi Karam, Mohammad Reza; Mohajerani, Hamid Reza

2015-01-01

Background: Methicillin-Resistant Staphylococcus aureus (MRSA) is a major pathogen in the hospital and community settings. Rapid methods to diagnose S. aureus infections are sought by many researchers worldwide. The current study aimed to utilize a phenotypic method of turanose fermentation to identify methicillin-susceptible and resistant S. aureus. Objectives: The current study aimed to assay the turanose metabolism at different dilutions as a rapid phenotypic method to identify MRSA isolates. Materials and Methods: A total of 150 Staphylococcus isolates were collected from Tehran health centers. Staphylococcus aureus isolates were identified based on cultural characteristics, biochemical reactions and positive tube coagulase test. Methicillin resistance was determined by the disk diffusion method. The Polymerase Chain Reaction amplification was used to detect the mecA gene in MRSA isolates. All the methicillin-resistant and susceptible isolates were evaluated for turanose metabolism with 1%, 0.7% and 0.5% dilutions using the microplate method. Results: Out of the 150 staphylococcal isolates, 80 were identified as S. aureus. Among which 40 (50%) of the isolates were MRSA. The mecA gene was present in all S. aureus isolates resistant to methicillin. A considerable difference was also observed between susceptible and resistant isolates of S. aureus at a 0.7% dilution of turanose. Conclusions: Since it is highly important to rapidly detect MRSA isolates, especially in nosocomial infections, phenotypic methods may certainly be useful for this purpose. Resistance to methicillin in S. aureus shows a substantially increased ability in turanose metabolism. It is concluded that fermentation of turanose at 0.7% dilution could be a rapid detection method for primary screening of MRSA isolates. PMID:26495105

Molecular epidemiology of Staphylococcus aureus isolates at different sites in the milk producing dairy farms

PubMed Central

Souza, Viviane; Nader Filho, Antonio; de Castro Melo, Poliana; Ferraudo, Guilherme Moraes; Antônio Sérgio, Ferraudo; de Oliveira Conde, Sandra; Fogaça Junior, Flavio Augusto

2012-01-01

The epidemiological relationships between isolated Staphylococcus aureus strains in milk samples of dairy cows, reagent to California Mastitis Test, individual and group milk was demonstrated in different sites of the production fluxogram, in 12 milk-producing farms in the Gameleira region, municipality of Sacramento MG Brazil, so that localization and transmission modes may be identified. Two hundred and forty-four strains out of 446 samples collected at several sites were isolated and bio-chemically characterized as coagulase-positive staphylococcus. Specific chromosome DNA fragment of the species Staphylococcus aureus was amplified to 106 strains and 103 underwent (PFGE). Samples’ collection sites with the highest isolation frequency of Staphylococcus aureus strains comprised papillary ostia (31.1%), CMT-reagent cow milk (21.7%), mechanical milking machines’ insufflators (21,7%), milk in milk pails (6.6%) and the milk in community bulk tanks (5.6%). Genetic heterogeneity existed among the isolated 103 Staphylococcus aureus strains, since 32 different pulse-types were identified. Pulse-type 1 had the highest similarity among the isolated strains within the different sites of the milk-production fluxogram. Highest occurrence of pulsetype 1 isolates of Staphylococcus aureus strains was reported in samples collected from the papillary ostia (10.6%), followed by milk samples from CMT-reagent dairy cows (5.8%) and mechanical milking machine insufflators (3.8%). The above shows the relevance of these sites in the agents’ transmission mechanism within the context of the farms investigated. PMID:24031997

Spontaneous methicillin-resistant Staphylococcus aureus (MRSA) meningitis.

PubMed

Longhurst, William D; Sheele, Johnathan M

2018-05-01

Spontaneous methicillin-resistant Staphylococcus aureus (MRSA) meningitis is extremely rare and has a high mortality rate. We report a case of MRSA meningitis in an otherwise healthy young adult female with no recent trauma or neurosurgical interventions. Despite antibiotics she suffered a vasculitis-induced cerebral vascular ischemic event. Copyright © 2018 Elsevier Inc. All rights reserved.

Human health risks associated with antimicrobial-resistant enterococci and Staphylococcus aureus on poultry meat.

PubMed

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.

Novel staphylococcal species that form part of a Staphylococcus aureus-related complex: the non-pigmented Staphylococcus argenteus sp. nov. and the non-human primate-associated Staphylococcus schweitzeri sp. nov.

PubMed

Tong, Steven Y C; Schaumburg, Frieder; Ellington, Matthew J; Corander, Jukka; Pichon, Bruno; Leendertz, Fabian; Bentley, Stephen D; Parkhill, Julian; Holt, Deborah C; Peters, Georg; Giffard, Philip M

2015-01-01

We define two novel species of the genus Staphylococcus that are phenotypically similar to and have near identical 16S rRNA gene sequences to Staphylococcus aureus. However, compared to S. aureus and each other, the two species, Staphylococcus argenteus sp. nov. (type strain MSHR1132(T) = DSM 28299(T) = SSI 89.005(T)) and Staphylococcus schweitzeri sp. nov. (type strain FSA084(T) = DSM 28300(T) = SSI 89.004(T)), demonstrate: 1) at a whole-genome level considerable phylogenetic distance, lack of admixture, average nucleotide identity <95 %, and inferred DNA-DNA hybridization <70 %; 2) different profiles as determined by MALDI-TOF MS; 3) a non-pigmented phenotype for S. argenteus sp. nov.; 4) S. schweitzeri sp. nov. is not detected by standard nucA PCR; 5) distinct peptidoglycan types compared to S. aureus; 6) a separate ecological niche for S. schweitzeri sp. nov.; and 7) a distinct clinical disease profile for S. argenteus sp. nov. compared to S. aureus. © 2015 IUMS.

21 CFR 866.3700 - Staphylococcus aureus serological reagents.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Staphylococcus aureus serological reagents. 866.3700 Section 866.3700 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3700...

21 CFR 866.3700 - Staphylococcus aureus serological reagents.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Staphylococcus aureus serological reagents. 866.3700 Section 866.3700 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3700...

21 CFR 866.3700 - Staphylococcus aureus serological reagents.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Staphylococcus aureus serological reagents. 866.3700 Section 866.3700 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3700...

21 CFR 866.3700 - Staphylococcus aureus serological reagents.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Staphylococcus aureus serological reagents. 866.3700 Section 866.3700 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3700...

21 CFR 866.3700 - Staphylococcus aureus serological reagents.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Staphylococcus aureus serological reagents. 866.3700 Section 866.3700 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3700...

Staphylococcus aureus, Staphylococcus epidermidis and Staphylococcus haemolyticus: methicillin-resistant isolates are detected directly in blood cultures by multiplex PCR.

PubMed

Pereira, Eliezer M; Schuenck, Ricardo P; Malvar, Karoline L; Iorio, Natalia L P; Matos, Pricilla D M; Olendzki, André N; Oelemann, Walter M R; dos Santos, Kátia R N

2010-03-31

In this study, we standardized and evaluated a multiplex-PCR methodology using specific primers to identify Staphylococcus aureus, Staphylococcus epidermidis and Staphylococcus haemolyticus and their methicillin-resistance directly from blood cultures. Staphylococci clinical isolates (149) and control strains (16) previously identified by conventional methods were used to establish the multiplex PCR protocol. Subsequently, this methodology was evaluated using a fast and cheap DNA extraction protocol from 25 staphylococci positive blood cultures. A wash step of the pellet with 0.1% bovine serum albumin (BSA) solution was performed to reduce PCR inhibitors. Amplicons of 154bp (mecA gene), 271bp (S. haemolyticus mvaA gene) and 108 and 124bp (S. aureus and S. epidermidis species-specific fragments, respectively) were observed. Reliable results were obtained for 100% of the evaluated strains, suggesting that this new multiplex-PCR combined with an appropriate DNA-extraction method could be useful in the laboratory for fast and accurate identification of three staphylococci species and simultaneously their methicillin resistance directly in blood cultures.

THE EFFECT OF STAPHYLOCOCCUS AUREUS TOXIN ON THE KIDNEY

PubMed Central

VonGlahn, William C.; Weld, Julia T.

1935-01-01

1. The hemolytic Staphylococcus aureus elaborates a toxin in vitro that when injected intravenously produces lesions in the kidneys of rabbits and cats. 2. The toxin injures primarily the blood vessels of the kidney. PMID:19870338

Epidemiology of Staphylococcus aureus during space flight

NASA Technical Reports Server (NTRS)

Pierson, D. L.; Chidambaram, M.; Heath, J. D.; Mallary, L.; Mishra, S. K.; Sharma, B.; Weinstock, G. M.

1996-01-01

Staphylococcus aureus was isolated over 2 years from Space Shuttle mission crewmembers to determine dissemination and retention of bacteria. Samples before and after each mission were from nasal, throat, urine, and feces and from air and surface sampling of the Space Shuttle. DNA fingerprinting of samples by digestion of DNA with SmaI restriction endonuclease followed by pulsed-field gel electrophoresis showed S. aureus from each crewmember had a unique fingerprint and usually only one strain was carried by an individual. There was only one instance of transfer between crewmembers. Strains from interior surfaces after flight matched those of crewmembers, suggesting microbial fingerprinting may have forensic application.

Antimicrobial resistance and virulence characterization of Staphylococcus aureus and coagulase-negative staphylococci from imported beef meat.

PubMed

Osman, Kamelia; Alvarez-Ordóñez, Avelino; Ruiz, Lorena; Badr, Jihan; ElHofy, Fatma; Al-Maary, Khalid S; Moussa, Ihab M I; Hessain, Ashgan M; Orabi, Ahmed; Saad, Alaa; Elhadidy, Mohamed

2017-05-10

The objectives of this study were to characterize the diversity and magnitude of antimicrobial resistance among Staphylococcus species recovered from imported beef meat sold in the Egyptian market and the potential mechanisms underlying the antimicrobial resistance phenotypes including harboring of resistance genes (mecA, cfr, gyrA, gyrB, and grlA) and biofilm formation. The resistance gene mecA was detected in 50% of methicillin-resistant non-Staphylococcus aureus isolates (4/8). Interestingly, our results showed that: (i) resistance genes mecA, gyrA, gyrB, grlA, and cfr were absent in Staphylococcus hominis and Staphylococcus hemolyticus isolates, although S. hominis was phenotypically resistant to methicillin (MR-non-S. aureus) while S. hemolyticus was resistant to vancomycin only; (ii) S. aureus isolates did not carry the mecA gene (100%) and were phenotypically characterized as methicillin- susceptible S. aureus (MSS); and (iii) the resistance gene mecA was present in one isolate (1/3) of Staphylococcus lugdunensis that was phenotypically characterized as methicillin-susceptible non-S. aureus (MSNSA). Our findings highlight the potential risk for consumers, in the absence of actionable risk management information systems, of imported foods and advice a strict implementation of international standards by different venues such as CODEX to avoid the increase in prevalence of coagulase positive and coagulase negative Staphylococcus isolates and their antibiotic resistance genes in imported beef meat at the Egyptian market.

Subinhibitory quinupristin/dalfopristin attenuates virulence of Staphylococcus aureus.

PubMed

Koszczol, Carmen; Bernardo, Katussevani; Krönke, Martin; Krut, Oleg

2006-09-01

The semi-synthetic streptogramin quinupristin/dalfopristin antibiotic exerts potent bactericidal activity against Staphylococcus aureus. We investigated whether, like other bactericidal antibiotics used at subinhibitory concentrations, quinupristin/dalfopristin enhances release of toxins by Gram-positive cocci. The activity of quinupristin/dalfopristin on exotoxin release by S. aureus was investigated by 2D SDS-PAGE combined with MALDI-TOF/MS analysis and by western blotting. We show that quinupristin/dalfopristin at subinhibitory concentrations reduces the release of S. aureus factors that induce tumour necrosis factor secretion in macrophages. Furthermore, quinupristin/dalfopristin but not linezolid attenuated S. aureus-mediated killing of infected host cells. When added to S. aureus cultures at different stages of bacterial growth, quinupristin/dalfopristin reduced in a dose-dependent manner the release of specific virulence factors (e.g. autolysin, protein A, alpha- and beta-haemolysins, lipases). In contrast, other presumably non-toxic exoproteins remained unchanged. The results of the present study suggest that subinhibitory quinupristin/dalfopristin inhibits virulence factor release by S. aureus, which might be especially helpful for the treatment of S. aureus infections, where both bactericidal as well as anti-toxin activity may be advantageous.

Study on biofilm-forming properties of clinical isolates of Staphylococcus aureus.

PubMed

Taj, Yasmeen; Essa, Farhan; Aziz, Faisal; Kazmi, Shahana Urooj

2012-05-14

The purpose of this study was to observe the formation of biofilm, an important virulence factor, by isolates of Staphylococcus aureus (S. aureus) in Pakistan by different conventional methods and through electron microscopy. We screened 115 strains of S. aureus isolated from different clinical specimens by tube method (TM), air-liquid interface coverslip assay method, Congo red agar (CRA) method, and scanning electron microscopy (SEM). Out of 115 S. aureus isolates, 63 (54.78%) showed biofilm formation by tube method. Biofilm forming bacteria were further categorized as high producers (n = 23, 20%) and moderate producers (n = 40, 34.78%). TM coordinated well with the coverslip assay for strong biofilm-producing strains in 19 (16.5%) isolates. By coverslip method, weak producers were difficult to differentiate from biofilm negative isolates. Screening on CRA showed biofilm formation only in four (3.47%) strains. Scanning electron micrographs showed the biofilm-forming strains of S. aureus arranged in a matrix on the propylene surface and correlated well with the TM. Biofilm production is a marker of virulence for clinically relevant staphylococcal infections. It can be studied by various methods but screening on CRA is not recommended for investigation of biofilm formation in Staphylococcus aureus. Electron micrograph images correlate well with the biofilm production as observed by TM.

Propionibacterium-Produced Coproporphyrin III Induces Staphylococcus aureus Aggregation and Biofilm Formation

PubMed Central

Wollenberg, Michael S.; Claesen, Jan; Escapa, Isabel F.; Aldridge, Kelly L.; Fischbach, Michael A.

2014-01-01

ABSTRACT The majority of bacteria detected in the nostril microbiota of most healthy adults belong to three genera: Propionibacterium, Corynebacterium, and Staphylococcus. Among these staphylococci is the medically important bacterium Staphylococcus aureus. Almost nothing is known about interspecies interactions among bacteria in the nostrils. We observed that crude extracts of cell-free conditioned medium from Propionibacterium spp. induce S. aureus aggregation in culture. Bioassay-guided fractionation implicated coproporphyrin III (CIII), the most abundant extracellular porphyrin produced by human-associated Propionibacterium spp., as a cause of S. aureus aggregation. This aggregation response depended on the CIII dose and occurred during early stationary-phase growth, and a low pH (~4 to 6) was necessary but was not sufficient for its induction. Additionally, CIII induced plasma-independent S. aureus biofilm development on an abiotic surface in multiple S. aureus strains. In strain UAMS-1, CIII stimulation of biofilm depended on sarA, a key biofilm regulator. This study is one of the first demonstrations of a small-molecule-mediated interaction among medically relevant members of the nostril microbiota and the first description of a role for CIII in bacterial interspecies interactions. Our results indicate that CIII may be an important mediator of S. aureus aggregation and/or biofilm formation in the nostril or other sites inhabited by Propionibacterium spp. and S. aureus. PMID:25053784

Mass Spectrometry and Multiplex Antigen Assays to Assess Microbial Quality and Toxin Production of Staphylococcus aureus Strains Isolated from Clinical and Food Samples

PubMed Central

Attien, Paul; Sina, Haziz; Moussaoui, Wardi; Zimmermann-Meisse, Gaëlle; Dadié, Thomas; Keller, Daniel; Riegel, Philippe; Edoh, Vincent; Kotchoni, Simeon O.; Djè, Marcellin; Prévost, Gilles

2014-01-01

The aim of our study was to investigate the microbial quality of meat products and on some clinical samples in Abidjan focused on Staphylococcus genus and the toxin production profile of Staphylococcus aureus (S. aureus) isolated. Bacteria were collected from 240 samples of three meat products sold in Abidjan and 180 samples issued from clinical infections. The strains were identified by both microbiological and MALDI-TOF-MS methods. The susceptibility to antibiotics was determined by the disc diffusion method. The production of Panton-Valentine Leukocidin, LukE/D, and epidermolysins was screened using radial gel immunodiffusion. The production of staphylococcal enterotoxins and TSST-1 was screened by a Bio-Plex Assay. We observed that 96/240 of meat samples and 32/180 of clinical samples were contaminated by Staphylococcus. Eleven species were isolated from meats and 4 from clinical samples. Forty-two S. aureus strains were isolated from ours samples. Variability of resistance was observed for most of the tested antibiotics but none of the strains displays a resistance to imipenem and quinolones. We observed that 89% of clinical S. aureus were resistant to methicillin against 58% for those issued from meat products. All S. aureus isolates issued from meat products produce epidermolysins whereas none of the clinical strains produced these toxins. The enterotoxins were variably produced by both clinical and meat product samples. PMID:24987686

Genetic variation among Staphylococcus aureus strains from Norwegian bulk milk.

PubMed

Jørgensen, H J; Mørk, T; Caugant, D A; Kearns, A; Rørvik, L M

2005-12-01

Strains of Staphylococcus aureus obtained from bovine (n = 117) and caprine (n = 114) bulk milk were characterized and compared with S. aureus strains from raw-milk products (n = 27), bovine mastitis specimens (n = 9), and human blood cultures (n = 39). All isolates were typed by pulsed-field gel electrophoresis (PFGE). In addition, subsets of isolates were characterized using multilocus sequence typing (MLST), multiplex PCR (m-PCR) for genes encoding nine of the staphylococcal enterotoxins (SE), and the cloverleaf method for penicillin resistance. A variety of genotypes were observed, and greater genetic diversity was found among bovine than caprine bulk milk isolates. Certain genotypes, with a wide geographic distribution, were common to bovine and caprine bulk milk and may represent ruminant-specialized S. aureus. Isolates with genotypes indistinguishable from those of strains from ruminant mastitis were frequently found in bulk milk, and strains with genotypes indistinguishable from those from bulk milk were observed in raw-milk products. This indicates that S. aureus from infected udders may contaminate bulk milk and, subsequently, raw-milk products. Human blood culture isolates were diverse and differed from isolates from other sources. Genotyping by PFGE, MLST, and m-PCR for SE genes largely corresponded. In general, isolates with indistinguishable PFGE banding patterns had the same SE gene profile and isolates with identical SE gene profiles were placed together in PFGE clusters. Phylogenetic analyses agreed with the division of MLST sequence types into clonal complexes, and isolates within the same clonal complex had the same SE gene profile. Furthermore, isolates within PFGE clusters generally belonged to the same clonal complex.

Comparison of magnetic field effects on the growth of Staphylococcus Aureus and Staphylococcus Epidermidis

NASA Astrophysics Data System (ADS)

Do, Kevin; Masood, Samina

The effects of magnetic fields were investigated on two species of bacteria: Staphylococcus Aureus and Staphylococcus Epidermidis. Both cultures were grown independently in agar plates and nutrient broth with exposure to various conditions of static and oscillating magnetic fields. The effects were characterized by growth rate measurements via changes in optical density (OD) over incubation periods of 24-28 hours. Significant effects on the growth rates of both species were observed in the case of the time-varying magnetic field.

Staphylococcus aureus vs. Osteoblast: Relationship and Consequences in Osteomyelitis.

PubMed

Josse, Jérôme; Velard, Frédéric; Gangloff, Sophie C

2015-01-01

Bone cells, namely osteoblasts and osteoclasts work in concert and are responsible for bone extracellular matrix formation and resorption. This homeostasis is, in part, altered during infections by Staphylococcus aureus through the induction of various responses from the osteoblasts. This includes the over-production of chemokines, cytokines and growth factors, thus suggesting a role for these cells in both innate and adaptive immunity. S. aureus decreases the activity and viability of osteoblasts, by induction of apoptosis-dependent and independent mechanisms. The tight relationship between osteoclasts and osteoblasts is also modulated by S. aureus infection. The present review provides a survey of the relevant literature discussing the important aspects of S. aureus and osteoblast interaction as well as the ability for antimicrobial peptides to kill intra-osteoblastic S. aureus, hence emphasizing the necessity for new anti-infectious therapeutics.

Staphylococcus aureus vs. Osteoblast: Relationship and Consequences in Osteomyelitis

PubMed Central

Josse, Jérôme; Velard, Frédéric; Gangloff, Sophie C.

2015-01-01

Bone cells, namely osteoblasts and osteoclasts work in concert and are responsible for bone extracellular matrix formation and resorption. This homeostasis is, in part, altered during infections by Staphylococcus aureus through the induction of various responses from the osteoblasts. This includes the over-production of chemokines, cytokines and growth factors, thus suggesting a role for these cells in both innate and adaptive immunity. S. aureus decreases the activity and viability of osteoblasts, by induction of apoptosis-dependent and independent mechanisms. The tight relationship between osteoclasts and osteoblasts is also modulated by S. aureus infection. The present review provides a survey of the relevant literature discussing the important aspects of S. aureus and osteoblast interaction as well as the ability for antimicrobial peptides to kill intra-osteoblastic S. aureus, hence emphasizing the necessity for new anti-infectious therapeutics. PMID:26636047

An outbreak of food poisoning due to egg yolk reaction-negative Staphylococcus aureus.

PubMed

Miwa, N; Kawamura, A; Masuda, T; Akiyama, M

2001-03-20

An outbreak of staphylococcal food poisoning due to an egg yolk (EY) reaction-negative strain occurred in Japan. Twenty-one of 53 dam construction workers who ate boxed lunches prepared at their company cafeteria became ill, and eight required hospital treatment. The outbreak showed a typical incubation time (1.5-4 h with a median time of 2.7 h) and symptoms (vomiting and diarrhea) of staphylococcal food poisoning. Staphylococcus aureus, which produces staphylococcal enterotoxin (SE) A, was isolated from four fecal specimens of eight patients tested. Scrambled egg in the boxed lunches contained 20-40 ng/g of SEA, and 3.0 x 10(9)/g of viable S. aureus cells that produced this toxin. All isolates from patients and the food were EY reaction-negative, coagulase type II, and showed the same restriction fragment length polymorphism (RFLP) pattern. We concluded that the outbreak was caused by scrambled egg contaminated with EY reaction-negative S. aureus. In Japan, outbreaks of staphylococcal food poisoning are mainly caused by EY reaction-positive S. aureus, and EY reaction-negative colonies grown on agar plates containing EY are usually not analyzed further for detection of S. aureus. The present outbreak suggested that EY reaction-negative isolates should be subjected to further analysis to detect the causative agents of staphylococcal food poisoning.

Trends in incidence and resistance patterns of Staphylococcus aureus bacteremia.

PubMed

Jokinen, Elina; Laine, Janne; Huttunen, Reetta; Lyytikäinen, Outi; Vuento, Risto; Vuopio, Jaana; Syrjänen, Jaana

2018-01-01

Staphylococcus aureus bacteremia (SAB) causes a significant burden on the population. Several infection control measures have been implemented in Pirkanmaa county to combat a local epidemic with methicillin-resistant Staphylococcus aureus (MRSA). We aimed to study the epidemiology of SAB and antibiotic resistance of S. aureus and the possible influence of improved infection control. Register data from 2005 to 2015 were retrospectively analysed to study the antimicrobial susceptibility, the incidence and mortality in SAB in a population-based setting. The incidence of SAB increased during the study period from 21.6 to 35.8/100,000 population. The number of both health care-associated (HA) and community-associated (CA) cases has increased. The incidence of MSSA bacteremia increased from 19.9 to 35.2/100,000 population in Pirkanmaa in parallel to other parts of Finland. The incidence of MRSA bacteremia was 10-fold (4.5/100,000 population) higher in 2011 than in other parts of the country, but sank to the national level (0.59/100,000 population) in 2015. The fatality rate decreased from 22% to 17%. The proportion of penicillin-susceptible Staphylococcus aureus (PSSA) increased from 23.9% in 2008 to 43.1% in 2015. The incidence of both HA and CA SAB has increased since 2005. Conversely, the proportion of MRSA and PRSA bacteremia has decreased. Promotion of infection control measures may have reduced the incidence of MRSA bacteremia but not the overall incidence of SAB. The rising proportion of PSSA enables the use of targeted, narrow spectrum antimicrobials.

Staphylococcus aureus infections: transmission within households and the community

PubMed Central

Knox, Justin; Uhlemann, Anne-Catrin; Lowy, Franklin D.

2015-01-01

Staphylococcus aureus , both methicillin susceptible and resistant, are now major community-based pathogens worldwide. The basis for this is multifactorial and includes the emergence of epidemic clones with enhanced virulence, antibiotic resistance, colonization potential, or transmissibility. Household reservoirs of these unique strains are crucial to their success as community-based pathogens. Staphylococci become resident in households, either as colonizers or environmental contaminants, increasing the risk for recurrent infections. Interactions of household members with others in different households or at community sites including schools and daycare facilities play a critical role in the ability of these strains to become endemic. Colonization density at these sites appears to play an important role in facilitating transmission. The integration of research tools including whole genome sequencing, mathematical modeling and social network analysis have provided additional insight into the transmission dynamics of these strains. Thus far, interventions designed to reduce recurrent infections among household members have had limited success, likely due to the multiplicity of potential sources for recolonization. The development of better strategies to reduce the number of household-based infections will depend on greater insight into the different factors that contribute to the success of these uniquely successful epidemic clones of S. aureus. PMID:25864883

Methicillin-resistant Staphylococcus aureus: an overview for manual therapists().

PubMed

Green, Bart N; Johnson, Claire D; Egan, Jonathon Todd; Rosenthal, Michael; Griffith, Erin A; Evans, Marion Willard

2012-03-01

Methicillin-resistant Staphylococcus aureus (MRSA) is associated with difficult-to-treat infections and high levels of morbidity. Manual practitioners work in environments where MRSA is a common acquired infection. The purpose of this review is to provide a practical overview of MRSA as it applies to the manual therapy professions (eg, physical and occupational therapy, athletic training, chiropractic, osteopathy, massage, sports medicine) and to discuss how to identify and prevent MRSA infections in manual therapy work environments. PubMed and CINAHL were searched from the beginning of their respective indexing years through June 2011 using the search terms MRSA, methicillin-resistant Staphylococcus aureus, and Staphylococcus aureus. Texts and authoritative Web sites were also reviewed. Pertinent articles from the authors' libraries were included if they were not already identified in the literature search. Articles were included if they were applicable to ambulatory health care environments in which manual therapists work or if the content of the article related to the clinical management of MRSA. Following information extraction, 95 citations were included in this review, to include 76 peer-reviewed journal articles, 16 government Web sites, and 3 textbooks. Information was organized into 10 clinically relevant categories for presentation. Information was organized into the following clinically relevant categories: microbiology, development of MRSA, risk factors for infection, clinical presentation, diagnostic tests, screening tests, reporting, treatment, prevention for patients and athletes, and prevention for health care workers. Methicillin-resistant S aureus is a health risk in the community and to patients and athletes treated by manual therapists. Manual practitioners can play an essential role in recognizing MRSA infections and helping to control its transmission in the health care environment and the community. Essential methods for protecting patients

Incidence of Staphylococcus aureus and Analysis of Associated Bacterial Communities on Food Industry Surfaces

PubMed Central

Gutiérrez, Diana; Delgado, Susana; Vázquez-Sánchez, Daniel; Martínez, Beatriz; Cabo, Marta López; Rodríguez, Ana; Herrera, Juan J.

2012-01-01

Biofilms are a common cause of food contamination with undesirable bacteria, such as pathogenic bacteria. Staphylococcus aureus is one of the major bacteria causing food-borne diseases in humans. A study designed to determine the presence of S. aureus on food contact surfaces in dairy, meat, and seafood environments and to identify coexisting microbiota has therefore been carried out. A total of 442 samples were collected, and the presence of S. aureus was confirmed in 6.1% of samples. Sixty-three S. aureus isolates were recovered and typed by random amplification of polymorphic DNA (RAPD). Profiles were clustered into four groups which were related to specific food environments. All isolates harbored some potential virulence factors such as enterotoxin production genes, biofilm formation-associated genes, antibiotic resistance, or lysogeny. PCR-denaturing gradient gel electrophoresis (PCR-DGGE) fingerprints of bacterial communities coexisting with S. aureus revealed the presence of bacteria either involved in food spoilage or of concern for food safety in all food environments. Food industry surfaces could thus be a reservoir for S. aureus forming complex communities with undesirable bacteria in multispecies biofilms. Uneven microbiological conditions were found in each food sector, which indicates the need to improve hygienic conditions in food processing facilities, particularly the removal of bacterial biofilms, to enhance the safety of food products. PMID:23023749

Incidence of Staphylococcus aureus and analysis of associated bacterial communities on food industry surfaces.

PubMed

Gutiérrez, Diana; Delgado, Susana; Vázquez-Sánchez, Daniel; Martínez, Beatriz; Cabo, Marta López; Rodríguez, Ana; Herrera, Juan J; García, Pilar

2012-12-01

Biofilms are a common cause of food contamination with undesirable bacteria, such as pathogenic bacteria. Staphylococcus aureus is one of the major bacteria causing food-borne diseases in humans. A study designed to determine the presence of S. aureus on food contact surfaces in dairy, meat, and seafood environments and to identify coexisting microbiota has therefore been carried out. A total of 442 samples were collected, and the presence of S. aureus was confirmed in 6.1% of samples. Sixty-three S. aureus isolates were recovered and typed by random amplification of polymorphic DNA (RAPD). Profiles were clustered into four groups which were related to specific food environments. All isolates harbored some potential virulence factors such as enterotoxin production genes, biofilm formation-associated genes, antibiotic resistance, or lysogeny. PCR-denaturing gradient gel electrophoresis (PCR-DGGE) fingerprints of bacterial communities coexisting with S. aureus revealed the presence of bacteria either involved in food spoilage or of concern for food safety in all food environments. Food industry surfaces could thus be a reservoir for S. aureus forming complex communities with undesirable bacteria in multispecies biofilms. Uneven microbiological conditions were found in each food sector, which indicates the need to improve hygienic conditions in food processing facilities, particularly the removal of bacterial biofilms, to enhance the safety of food products.

Immunopathogenesis of Staphylococcus aureus pulmonary infection

PubMed Central

Parker, Dane; Prince, Alice

2013-01-01

Staphylococcus aureus is a common human pathogen highly evolved as both a component of the commensal flora and as a major cause of invasive infection. Severe respiratory infection due to staphylococci has been increasing due to the prevalence of more virulent USA300 CA-MRSA strains in the general population. The ability of S. aureus to adapt to the milieu of the respiratory tract has facilitated its emergence as a respiratory pathogen. Its metabolic versatility, the ability to scavenge iron, coordinate gene expression, and the horizontal acquisition of useful genetic elements have all contributed to its success as a component of the respiratory flora, in hospitalized patients, as a complication of influenza and in normal hosts. The expression of surface adhesins facilitates its persistence in the airways. In addition, the highly sophisticated interactions of the multiple S. aureus virulence factors, particularly the α-hemolysin and protein A, with diverse immune effectors in the lung such as ADAM10, TNFR1, EGFR, immunoglobulin, and complement all contribute to the pathogenesis of staphylococcal pneumonia. PMID:22037948

Screening and characterization of Staphylococcus aureus from ophthalmology clinic surfaces: a proposed surveillance tool

PubMed Central

Reem, Rachel E.; Van Balen, Joany; Hoet, Armando E.; Cebulla, Colleen M.

2014-01-01

Purpose To screen environmental surfaces of an outpatient ophthalmic clinic for methicillin-susceptible and methicillin-resistant Staphylococcus aureus (MSSA and MRSA); to identify the most commonly contaminated surfaces; and to phenotype and genotype all collected isolates Design A single institution, one-year prospective environmental study Methods Commonly touched surfaces from examination rooms and common areas were targeted and sampled on a quarterly basis for one year. Samples were collected using electrostatic cloths and swabs. S. aureus was isolated using non-selective and selective media. Morphological characteristics and standard biological testing were used to confirm staphylococcal species. S. aureus isolates were phenotypically (Kirby-Bauer method) and genotypically characterized (mecA confirmation, SCCmec typing and pulsed-field gel electrophoresis). Dendrogram analysis was used to establish genetic relatedness between the isolates. Results Of 112 total samples, 27 (24%) and 5 (4%) were MSSA- and MRSA-positive, respectively. Both community-associated (SCCmec IV, USA300) and hospital-associated (SCCmec II, USA100) MRSA isolates were found. No single surface remained consistently positive with the same isolate over time and molecular analysis demonstrated high levels of diversity among isolates. Doorknobs, slit-lamp head/chinrests, and computer keyboards were frequently contaminated. Conclusions The proposed surveillance protocol successfully allowed the detection of both MSSA and MRSA contaminating important high-touch surfaces in a representative ophthalmology clinic. Frequently contaminated surfaces must be targeted for routine cleaning and disinfection as a there is a constant introduction of clones over time. Hence, other clinics may consider implementing and adapting surveillance tools, as the one here described, to help them control these important nosocomial pathogens. PMID:24412125

Prevalence of Staphylococcus aureus and of methicillin-resistant S. aureus (MRSA) along the production chain of dairy products in north-western Greece.

PubMed

Papadopoulos, Panagiotis; Papadopoulos, Theofilos; Angelidis, Apostolos S; Boukouvala, Evridiki; Zdragas, Antonios; Papa, Anna; Hadjichristodoulou, Christos; Sergelidis, Daniel

2018-02-01

The objective of this study was to estimate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in the production chain of dairy products. Of 367 tested samples (36 bulk tank milk (BTM), 19 dairy products, 72 human, 185 animal, 55 equipment), 212 (57.8%) were found positive for S. aureus. Almost all isolates (99.6%) were resistant to at least one antimicrobial and 13.3% were multi-drug resistant (MDR), exhibiting resistance to three or more antibiotic classes. Eleven samples (3%) were found contaminated by MRSA carrying the mecA gene. None of the MRSA isolates carried the mecC or the Pandon-Valentine leucocidin (PVL) genes. Four spa types were identified among the MRSA isolates: t127, t3586, t1773, t4038, with t127 being the most prevalent (7 out of 11). Two of them, t3586 and t1773, were isolated for the first time in Greece. Furthermore, Pulse-Field Gel Electrophoresis (PFGE) analysis indicated clonal circulation through the dairy production chain. The presence of MDR S. aureus, and especially MRSA, in animals and dairy products represents a potential threat for the spread of this pathogen in the community. The results indicated that human, animal and environmental sources could be involved in the contamination of dairy products along their production chain and therefore further investigation of contamination sources is needed to control the dispersion of MRSA in the community. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Staphylococcus aureus RNome and Its Commitment to Virulence

PubMed Central

Felden, Brice; Vandenesch, François; Bouloc, Philippe; Romby, Pascale

2011-01-01

Staphylococcus aureus is a major human pathogen causing a wide spectrum of nosocomial and community-associated infections with high morbidity and mortality. S. aureus generates a large number of virulence factors whose timing and expression levels are precisely tuned by regulatory proteins and RNAs. The aptitude of bacteria to use RNAs to rapidly modify gene expression, including virulence factors in response to stress or environmental changes, and to survive in a host is an evolving concept. Here, we focus on the recently inventoried S. aureus regulatory RNAs, with emphasis on those with identified functions, two of which are directly involved in pathogenicity. PMID:21423670

Differentiation of Staphylococcus argenteus (formerly: Staphylococcus aureus clonal complex 75) by mass spectrometry from S. aureus using the first strain isolated from a wild African great ape.

PubMed

Schuster, Dominik; Rickmeyer, Jasmin; Gajdiss, Mike; Thye, Thorsten; Lorenzen, Stephan; Reif, Marion; Josten, Michaele; Szekat, Christiane; Melo, Luís D R; Schmithausen, Ricarda M; Liégeois, Florian; Sahl, Hans-Georg; Gonzalez, Jean-Paul J; Nagel, Michael; Bierbaum, Gabriele

2017-01-01

The species Staphylococcus argenteus was separated recently from Staphylococcus aureus (Tong S.Y., F. Schaumburg, M.J. Ellington, J. Corander, B. Pichon, F. Leendertz, S.D. Bentley, J. Parkhill, D.C. Holt, G. Peters, and P.M. Giffard, 2015). The objective of this work was to characterise the genome of a non-human S. argenteus strain, which had been isolated from the faeces of a wild-living western lowland gorilla in Gabon, and analyse the spectrum of this species in matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). The full genome sequence revealed a scarcity of virulence genes and absence of resistance genes, indicating a decreased virulence potential compared to S. aureus and the human methicillin-resistant S. argenteus isolate MSHR1132 T . Spectra obtained by MALDI-TOF MS and the analysis of available sequences in the genome databases identified several MALDI-TOF MS signals that clearly differentiate S. argenteus, the closely related Staphylococcus schweitzeri and S. aureus. In conclusion, in the absence of biochemical tests that identify the three species, mass spectrometry should be employed as method of choice. Copyright © 2016 Elsevier GmbH. All rights reserved.

Pulsed-field gel electrophoresis typing of Staphylococcus aureus isolates

USDA-ARS?s Scientific Manuscript database

Pulsed-field gel electrophoresis (PFGE) is the most applied and effective genetic typing method for epidemiological studies and investigation of foodborne outbreaks caused by different pathogens, including Staphylococcus aureus. The technique relies on analysis of large DNA fragments generated by th...

Detection of classical enterotoxins and identification of enterotoxin genes in Staphylococcus aureus from milk and dairy products.

PubMed

Morandi, S; Brasca, M; Lodi, R; Cremonesi, P; Castiglioni, B

2007-09-20

Milk and dairy products are frequently contaminated with enterotoxigenic Staphylococcus aureus, which is often involved in staphylococcal food poisoning. The distribution of genes encoding staphylococcal enterotoxins (SE) in S. aureus isolated from bovine, goat, sheep and buffalo milk and dairy products was verified by the presence of the corresponding SE production. A total of 112 strains of S. aureus were tested for SE production by immuno-enzymatic (SEA-SEE) and reversed passive latex agglutination (SEA-SED) methods, while multiplex-PCR was applied for SE genes (sea, sec, sed, seg, seh, sei, sej and sel). Of the total strains studied, 67% were detected to have some SE genes (se), but only 52% produced a detectable amount of the classic antigenic SE types. The bovine isolates frequently had enterotoxin SEA, SED and sej, while SEC and sel predominated in the goat and sheep strains. The results demonstrated (i) marked enterotoxigenic S. aureus strain variations, in accordance with strain origin and (ii) the two methods resulted in different information but concurred on the risk of foodstuff infection by S. aureus.

In Vitro Pharmacodynamics of AZD5206 against Staphylococcus aureus

PubMed Central

Chang, Kai-Tai; Yang, Zhen; Newman, Joseph; Hu, Ming

2013-01-01

AZD5206 is a novel antimicrobial agent with potent in vitro activity against Staphylococcus aureus. We evaluated the in vitro pharmacodynamics of AZD5206 against a standard wild-type methicillin-susceptible strain (ATCC 29213) and a clinical strain of methicillin-resistant S. aureus (SA62). Overall, bacterial killing against a low baseline inoculum was more remarkable. Low dosing exposures and/or high baseline inoculum resulted in early reduction in bacterial burden, followed by regrowth and selective amplification of the resistant population. PMID:23229481

Molecular typing of antibiotic-resistant Staphylococcus aureus in Nigeria.

PubMed

O'Malley, S M; Emele, F E; Nwaokorie, F O; Idika, N; Umeizudike, A K; Emeka-Nwabunnia, I; Hanson, B M; Nair, R; Wardyn, S E; Smith, T C

2015-01-01

Antibiotic-resistant Staphylococcus aureus including methicillin-resistant strains (MRSA) are a major concern in densely populated urban areas. Initial studies of S. aureus in Nigeria indicated existence of antibiotic-resistant S. aureus strains in clinical and community settings. 73 biological samples (40 throat, 23 nasal, 10 wound) were collected from patients and healthcare workers in three populations in Nigeria: Lagos University Teaching Hospital, Nigerian Institute of Medical Research, and Owerri General Hospital. S. aureus was isolated from 38 of 73 samples (52%). Of the 38 S. aureus samples, 9 (24%) carried the Panton-Valentine leukocidin gene (PVL) while 16 (42%) possessed methicillin resistance genes (mecA). Antibiotic susceptibility profiles indicated resistance to several broad-spectrum antibiotics. Antibiotic-resistant S. aureus isolates were recovered from clinical and community settings in Nigeria. Insight about S. aureus in Nigeria may be used to improve antibiotic prescription methods and minimize the spread of antibiotic-resistant organisms in highly populated urban communities similar to Lagos, Nigeria. Copyright © 2014 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

Human-associated methicillin-resistant Staphylococcus aureus from a subtropical recreational marine beach

USDA-ARS?s Scientific Manuscript database

Reports of Staphylococcus aureus detected in marine environments have occurred since the early 1990’s. This investigation sought to isolate and characterize S. aureus from marine waters and sand at a subtropical recreational beach, with and without bathers present, in order to investigate possible s...

Triple-acting Peptidoglycan hydrolase treatment for drug-resistant and intracellular Staphylococcus aureus

USDA-ARS?s Scientific Manuscript database

Multi-drug resistant bacteria are a persistent problem in modern health care, food safety and animal health. There is a need for new antimicrobials to replace over-used conventional antibiotics. Staphylococcus aureus (S. aureus) is a notorious pathogen for both animal and human health with multi-d...

Identification and characterization of methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus haemolyticus and Staphylococcus pettenkoferi from a small animal clinic.

PubMed

Weiss, Sonja; Kadlec, Kristina; Fessler, Andrea T; Schwarz, Stefan

2013-12-27

The aim of this study was to isolate and characterize methicillin-resistant staphylococci (MRS) in a small animal clinic and to investigate their distribution and possible transmission. Swabs (n=72) were taken from hospitalized pets, the environment and employees of a small animal clinic and screened for the presence of MRS. The staphylococcal species was confirmed biochemically or by 16S rDNA sequencing. Susceptibility to antimicrobial agents was tested by broth dilution. The presence of mecA and other resistance genes was confirmed by PCR. Molecular typing of the isolates followed standard procedures. In total, 34 MRS belonging to the four species Staphylococcus aureus (n=5), Staphylococcus epidermidis (n=21), Staphylococcus haemolyticus (n=6) or Staphylococcus pettenkoferi (n=2) were isolated. All isolates were multidrug-resistant with resistance to at least three classes of antimicrobial agents. Among the five methicillin-resistant S. aureus (MRSA) isolates, four belonged to the clonal complex CC398; two of them were isolated from cats, the remaining two from pet cages. Overall, the MRS isolates differed in their characteristics, except for one S. epidermidis clone (n=9) isolated from hospitalized cats without clinical staphylococcal infections, pet cages, the clinic environment as well as from a healthy employee. This MRSE clone was resistant to 10 classes of antimicrobial agents, including aminocyclitols, β-lactams, fluoroquinolones, lincosamides, macrolides, phenicols, pleuromutilins, sulfonamides, tetracyclines and trimethoprim. These findings suggest a possible transmission of specific MRS isolates between animal patients, employees and the clinic environment. Copyright © 2013 Elsevier B.V. All rights reserved.

Virulence factors and genetic variability of Staphylococcus aureus strains isolated from raw sheep's milk cheese.

PubMed

Spanu, Vincenzo; Spanu, Carlo; Virdis, Salvatore; Cossu, Francesca; Scarano, Christian; De Santis, Enrico Pietro Luigi

2012-02-01

Contamination of dairy products with Staphylococcus aureus can be of animal or human origin. The host pathogen relationship is an important factor determining genetic polymorphism of the strains and their potential virulence. The aim of the present study was to carry out an extensive characterization of virulence factors and to study the genetic variability of S. aureus strains isolated from raw ewe's milk cheese. A total of 100 S. aureus strains isolated from cheese samples produced in 10 artisan cheese factories were analyzed for the presence of enterotoxins (sea-see) and enterotoxins-like genes (seh, sek, sel, sem, seo, sep), leukocidins, exfoliatins, haemolysins, toxic shock syndrome toxin 1 (TSST-1) and the accessory gene regulator alleles (agr). Strains were also typed using pulsed-field gel electrophoresis (PFGE). AMOVA analysis carried out on PFGE and PCR data showed that the major component explaining genetic distance between strains was the dairy of origin. Of the total isolates 81% had a pathogenicity profile ascribable to "animal" biovar while 16% could be related to "human" biovar. The biovar allowed to estimate the most likely origin of the contamination. Minimum inhibitory concentrations (MICs) of nine antimicrobial agents and the presence of the corresponding genes coding for antibiotic resistance was also investigated. 18 strains carrying blaZ gene showed resistance to ampicillin and penicillin and 6 strains carrying tetM gene were resistant to tetracycline. The presence of mecA gene and methicillin resistance, typical of strains of human origin, was never detected. The results obtained in the present study confirm that S. aureus contamination in artisan cheese production is mainly of animal origin. Copyright © 2011. Published by Elsevier B.V.

[Epidemic of Staphylococcus aureus nosocomial infections resistant to methicillin in a maternity ward].

PubMed

Le Coq, M; Simon, I; Sire, C; Tissot-Guerraz, F; Fournier, L; Aho, S; Noblot, G; Reverdy, M E; Françoise, M

2001-02-01

Methicillin-resistant Staphylococcus aureus (MRSA) nosocomial infections frequently occur in the hospital environment, but their incidence is less often observed in neonates. In the present investigation, seventeen cases were recorded over a nine-week period (two cases per week). Pulsed field gradient gel electrophoresis confirmed the clonal character of the strain. The hypothesis of manually-transmitted infection due to contamination from multiple sources was reinforced by the fact the epidemic persisted in spite of the elimination of the main human infectious source and an absence of risk factors determined by the case-control study. The role of environmental factors in the persistence of this outbreak of MRSA infection has been considered.

Vancomycin-resistant Staphylococcus aureus (VRSA) in hepatic cirrhosis patient: a case report

NASA Astrophysics Data System (ADS)

Ramazoni, M.; Siregar, M. L.; Jamil, K. F.

2018-03-01

The irrational use of vancomycin in methicillin-resistant Staphylococcus aureus (MRSA) infections result in the emergence of vancomycin-resistant Staphylococcus aureus (VRSA) pathogen, which can pose a threat to the world healthcare. A 32-year-old male with hepatic cirrhosis patient admitted with recurrent gastrointestinal bleeding with a wound in his left leg since 6 months ago; the result microbiological culture showed a VRSA with minimum inhibitory concentration (MIC) vancomycin ≥32μg/mL The patient was treated with trimethoprim/sulfamethoxazole combination according to cultural sensitivity. The second microbiological culture showed thesame result. VRSA is a rare and difficult condition to handle. The success of therapy for this VRSA case warn us how important to cut the S. aureus distribution chain with a high level of resistance.

Toxic Shock Syndrome Caused by Methicillin-Resistant Staphylococcus aureus (MRSA) After Expander-Based Breast Reconstruction.

PubMed

Suga, Hirotaka; Shiraishi, Tomohiro; Takushima, Akihiko; Harii, Kiyonori

2016-01-01

Toxic shock syndrome is a rare but life-threatening complication after plastic surgery procedures. We experienced 2 cases of toxic shock syndrome after expander-based breast reconstruction caused by methicillin-resistant Staphylococcus aureus. The first patient took a severe clinical course due to the delayed diagnosis and treatment, and the second patient recovered rapidly after the early diagnosis and treatment based on our experience of the first case. Fever, rash, and gastrointestinal symptoms (diarrhea and/or vomiting) were characteristic and important for the early diagnosis of toxic shock syndrome. Considering the increased prevalence of methicillin-resistant Staphylococcus aureus, we should suspect methicillin-resistant Staphylococcus aureus in cases of toxic shock syndrome that occur postoperatively, and the empiric administration of vancomycin should be initiated in such cases.

Bats are rare reservoirs of Staphylococcus aureus complex in Gabon.

PubMed

Held, Jana; Gmeiner, Markus; Mordmüller, Benjamin; Matsiégui, Pierre-Blaise; Schaer, Juliane; Eckerle, Isabella; Weber, Natalie; Matuschewski, Kai; Bletz, Stefan; Schaumburg, Frieder

2017-01-01

The colonization of afro-tropical wildlife with Staphylococcus aureus and the derived clade Staphylococcus schweitzeri remains largely unknown. A reservoir in bats could be of importance since bats and humans share overlapping habitats. In addition, bats are food sources in some African regions and can be the cause of zoonotic diseases. Here, we present a cross-sectional survey employing pharyngeal swabs of captured and released bats (n=133) in a forest area of Gabon. We detected low colonization rates of S. aureus (4-6%) and S. schweitzeri (4%) in two out of four species of fruit bats, namely Rousettus aegyptiacus and Micropteropus pusillus, but not in insectivorous bats. Multilocus sequence typing showed that S. aureus from Gabonese bats (ST2984, ST3259, ST3301, ST3302) were distinct from major African human associated clones (ST15, ST121, ST152). S. schweitzeri from bats (ST1697, ST1700) clustered with S. schweitzeri from other species (bats, monkeys) from Nigeria and Côte d'Ivoire. In conclusion, colonization rates of bats with S. aureus and S. schweitzeri were low in our study. Phylogenetic analysis supports an intense geographical dispersal of S. schweitzeri among different mammalian wildlife hosts. Copyright © 2016 Elsevier B.V. All rights reserved.

Sensitivity of Mixed Populations of Staphylococcus aureus and Escherichia coli to Mercurials

PubMed Central

Stutzenberger, F. J.; Bennett, E. O.

1965-01-01

Staphylococcus aureus was found to have a higher resistance to merbromin and mercuric chloride in the presence of Escherichia coli. The protective effect of the gram-negative organism on S. aureus was due to the production of extracellular glutathione and hydrogen sulfide and to an unequal distribution of the inhibitor between the two species. S. aureus did not significantly influence the resistance of E. coli to mercurials. PMID:14339264

Tracing Staphylococcus aureus in small and medium-sized food-processing factories on the basis of molecular sub-species typing.

PubMed

Koreňová, Janka; Rešková, Zuzana; Véghová, Adriana; Kuchta, Tomáš

2015-01-01

Contamination by Staphylococcus aureus of the production environment of three small or medium-sized food-processing factories in Slovakia was investigated on the basis of sub-species molecular identification by multiple locus variable number of tandem repeats analysis (MLVA). On the basis of MLVA profiling, bacterial isolates were assigned to 31 groups. Data from repeated samplings over a period of 3 years facilitated to draw spatial and temporal maps of the contamination routes for individual factories, as well as identification of potential persistent strains. Information obtained by MLVA typing allowed to identify sources and routes of contamination and, subsequently, will allow to optimize the technical and sanitation measures to ensure hygiene.

Proportions of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus in patients with surgical site infections in mainland China: a systematic review and meta-analysis.

PubMed

Yang, Zhirong; Wang, Jing; Wang, Weiwei; Zhang, Yuelun; Han, Lizhong; Zhang, Yuan; Nie, Xiaolu; Zhan, Siyan

2015-01-01

Sufficient details have not been specified for the epidemiological characteristics of Staphylococcus aureus (S. aureus) and methicillin-resistant Staphylococcus aureus (MRSA) among surgical site infections (SSIs) in mainland China. This systematic review aimed to estimate proportions of S. aureus and MRSA in SSIs through available published studies. PubMed, Embase and four Chinese electronic databases were searched to identify relevant primary studies published between 2007 and 2012. Meta-analysis was conducted on the basis of logit-transformed metric for proportions of S. aureus and MRSA, followed by pre-defined subgroup meta-analysis. Random-effects meta-regression was also conducted to explore the impact of possible factors on S. aureus proportions. 106 studies were included, of which 38 studies involved MRSA. S. aureus accounted for 19.1% (95%CI 17.2-21.0%; I(2) = 84.1%) of all isolates in SSIs, which was roughly parallel to 18.5% in the United States (US) (P-value = 0.57) but significantly exceeded those calculated through the surveillance system in China (P-value<0.001). In subgroup analysis, S. aureus in patients with thoracic surgery (41.1%, 95%CI 26.3-57.7%; I(2) = 74.4%) was more common than in those with gynecologic surgery (20.1%, 95%CI 15.6-25.6%; I(2) = 33.0%) or abdominal surgery (13.8%, 95%CI 10.3-18.4%; I(2) = 70.0%). Similar results were found in meta-regression. MRSA accounted for 41.3% (95%CI 36.5-46.3%; I(2) = 64.6%) of S. aureus, significantly lower than that in the US (P-value = 0.001). MRSA was sensitive to vancomycin (522/522) and linezolid (93/94), while 79.9% (95%CI 67.4-88.4%; I(2) = 0%) and 92.0% (95%CI 80.2-97.0%; I(2) = 0%) of MRSA was resistant to clindamycin and erythromycin respectively. The overall proportion of S. aureus among SSIs in China was similar to that in the US but seemed higher than those reported through the Chinese national surveillance system. Proportions of S. aureus SSIs may vary with different surgery types

Mixed Lactobacillus plantarum Strains Inhibit Staphylococcus aureus Induced Inflammation and Ameliorate Intestinal Microflora in Mice.

PubMed

Ren, Dayong; Gong, Shengjie; Shu, Jingyan; Zhu, Jianwei; Rong, Fengjun; Zhang, Zhenye; Wang, Di; Gao, Liangfeng; Qu, Tianming; Liu, Hongyan; Chen, Ping

2017-01-01

Objective . Staphylococcus aureus is an important pathogen that causes intestinal infection. We examined the immunomodulatory function of single and mixed Lactobacillus plantarum strains, as well as their impacts on the structure of the microbiome in mice infected with Staphylococcus aureus . The experiment was divided into three groups: protection, treatment, and control. Serum IFN- γ and IL-4 levels, as well as intestinal sIgA levels, were measured during and 1 week after infection with Staphylococcus aureus with and without Lactobacillus plantarum treatment. We used 16s rRNA tagged sequencing to analyze microbiome composition. IFN- γ /IL-4 ratio decreased significantly from infection to convalescence, especially in the mixed Lactobacillus plantarum group. In the mixed Lactobacillus plantarum group the secretion of sIgA in the intestine of mice (9.4-9.7 ug/mL) was significantly higher than in the single lactic acid bacteria group. The dominant phyla in mice are Firmicutes , Bacteroidetes , and Proteobacteria . Treatment with mixed lactic acid bacteria increased the anti-inflammatory factor and the secretion of sIgA in the intestine of mice infected with Staphylococcus aureus and inhibited inflammation.

Evolving Epidemiology of Staphylococcus aureus Bacteremia.

PubMed

Rhee, Yoona; Aroutcheva, Alla; Hota, Bala; Weinstein, Robert A; Popovich, Kyle J

2015-12-01

Methicillin-resistant Staphylococcus aureus (MRSA) infections due to USA300 have become widespread in community and healthcare settings. It is unclear whether risk factors for bloodstream infections (BSIs) differ by strain type. To examine the epidemiology of S. aureus BSIs, including USA300 and non-USA300 MRSA strains. Retrospective observational study with molecular analysis. Large urban public hospital. Individuals with S. aureus BSIs from January 1, 2007 through December 31, 2013. We used electronic surveillance data to identify cases of S. aureus BSI. Available MRSA isolates were analyzed by pulsed-field gel electrophoresis. Poisson regression was used to evaluate changes in BSI incidence over time. Risk factor data were collected by medical chart review and logistic regression was used for multivariate analysis of risk factors. A total of 1,015 cases of S. aureus BSIs were identified during the study period; 36% were due to MRSA. The incidence of hospital-onset (HO) MRSA BSIs decreased while that of community-onset (CO) MRSA BSIs remained stable. The rate of CO- and HO- methicillin-susceptible S. aureus infections both decreased over time. More than half of HO-MRSA BSIs were due to the USA300 strain type and for 4 years, the proportion of HO-MRSA BSIs due to USA300 exceeded 60%. On multivariate analysis, current or former drug use was the only epidemiologic risk factor for CO- or HO-MRSA BSIs due to USA300 strains. USA300 MRSA is endemic in communities and hospitals and certain populations (eg, those who use illicit drugs) may benefit from enhanced prevention efforts in the community.

Genetic Variation among Staphylococcus aureus Strains from Norwegian Bulk Milk

PubMed Central

Jørgensen, H. J.; Mørk, T.; Caugant, D. A.; Kearns, A.; Rørvik, L. M.

2005-01-01

Strains of Staphylococcus aureus obtained from bovine (n = 117) and caprine (n = 114) bulk milk were characterized and compared with S. aureus strains from raw-milk products (n = 27), bovine mastitis specimens (n = 9), and human blood cultures (n = 39). All isolates were typed by pulsed-field gel electrophoresis (PFGE). In addition, subsets of isolates were characterized using multilocus sequence typing (MLST), multiplex PCR (m-PCR) for genes encoding nine of the staphylococcal enterotoxins (SE), and the cloverleaf method for penicillin resistance. A variety of genotypes were observed, and greater genetic diversity was found among bovine than caprine bulk milk isolates. Certain genotypes, with a wide geographic distribution, were common to bovine and caprine bulk milk and may represent ruminant-specialized S. aureus. Isolates with genotypes indistinguishable from those of strains from ruminant mastitis were frequently found in bulk milk, and strains with genotypes indistinguishable from those from bulk milk were observed in raw-milk products. This indicates that S. aureus from infected udders may contaminate bulk milk and, subsequently, raw-milk products. Human blood culture isolates were diverse and differed from isolates from other sources. Genotyping by PFGE, MLST, and m-PCR for SE genes largely corresponded. In general, isolates with indistinguishable PFGE banding patterns had the same SE gene profile and isolates with identical SE gene profiles were placed together in PFGE clusters. Phylogenetic analyses agreed with the division of MLST sequence types into clonal complexes, and isolates within the same clonal complex had the same SE gene profile. Furthermore, isolates within PFGE clusters generally belonged to the same clonal complex. PMID:16332822

Multiple Cross Displacement Amplification Coupled With Nanoparticles-Based Lateral Flow Biosensor for Detection of Staphylococcus aureus and Identification of Methicillin-Resistant S. aureus.

PubMed

Wang, Yi; Yan, Weiqiang; Fu, Shanshan; Hu, Shoukui; Wang, Yan; Xu, Jianguo; Ye, Changyun

2018-01-01

Staphylococcus aureus ( S. aureus ), including methicillin-resistant S. aureus (MRSA), is one of the most important human pathogens, which is responsible for bacteremia, soft-tissue infections, and food poisoning. Hence, multiple cross displacement amplification (MCDA) is employed to detect all S. aureus strains, and differentiates MRSA from methicillin-sensitive S. aureus . Multiplex MCDA (m-MCDA), which targets the nuc gene ( S. aureus -specific gene) and mecA gene (encoding penicillin-binding protein-2'), could detect S. aureus strains and identify MRSA within 85 min. Detection of the m-MCDA products is achieved using disposable lateral flow biosensors. A total of 58 strains, including various species of Gram-positive and Gram-negative strains, are used for evaluating and optimizing m-MCDA assays. The optimal amplification condition is found to be 63°C for 40 min, with detection limits at 100 fg DNA/reaction for nuc and mecA genes in the pure cultures, and 10 CFU/tube for nuc and mecA genes in the blood samples. The analytical specificity of m-MCDA assay is of 100%, and no cross-reactions to non- S. aureus strains are produced according to the specificity testing. Particularly, two additional components, including AUDG enzyme and dUTP, are added into the m-MCDA amplification mixtures, which are used for eliminating the unwanted results arising from carryover contamination. Thus, the m-MCDA technique appears to be a simple, rapid, sensitive, and reliable assay to detect all S. aureus strains, and identify MRSA infection for appropriate antibiotic therapy.

Methicillin-Resistant "Staphylococcus aureus" on Campus: A New Challenge to College Health

ERIC Educational Resources Information Center

Weiner, H. Richard

2008-01-01

As new drugs to control bacterial pathogens are developed, the organisms evolve to survive. "Staphylococcus aureus", a common organism, has steadily developed resistance to antibiotics. For more than 40 years, resistant "S. aureus" presented a formidable problem to hospitalized patients; in the past decade, however, it has begun to appear outside…

Accuracy of tracheal aspirate gram stain in predicting Staphylococcus aureus infection in ventilator-associated pneumonia.

PubMed

Seligman, Renato; Seligman, Beatriz Graeff Santos; Konkewicz, Loriane; Dos Santos, Rodrigo Pires

2015-01-01

The Gram stain can be used to direct initial empiric antimicrobial therapy when complete culture is not available. This rapid test could prevent the initiation of inappropriate therapy and adverse outcomes. However, several studies have attempted to determine the value of the Gram stain in the diagnosis and therapy of bacterial infection in different populations of patients with ventilator-associated pneumonia (VAP) with conflicting results. The objective of this study is to evaluate the accuracy of the Gram stain in predicting the existence of Staphylococcus aureus infections from cultures of patients suspected of having VAP. This prospective single-center open cohort study enrolled 399 patients from December 2005 to December 2010. Patients suspected of having VAP by ATS IDSA criteria were included. Respiratory secretion samples were collected by tracheal aspirate (TA) for standard bacterioscopic analysis by Gram stain and culture. Respiratory secretion samples collected by tracheal aspirates of 392 patients were analyzed by Gram stain and culture. When Gram-positive cocci were arranged in clusters, the sensitivity was 68.4%, specificity 97.8%, positive predictive value 88.1% and negative predictive value 92.8% for predicting the presence of Staphylococcus aureus in culture (p < 0.001). A tracheal aspirate Gram stain can be used to rule out the presence of Staphylococcus aureus in patients with a clinical diagnosis of VAP with a 92.8% Negative Predictive Value. Therefore, 7.2% of patients with Staphylococcus aureus would not be protected by an empiric treatment that limits antimicrobial coverage to Staphylococcus aureus only when Gram positive cocci in clusters are identified.

Increasing rate of daptomycin non-susceptible strains of Staphylococcus aureus in patients with atopic dermatitis.

PubMed

Błażewicz, Izabela; Jaśkiewicz, Maciej; Piechowicz, Lidia; Neubauer, Damian; Nowicki, Roman J; Kamysz, Wojciech; Barańska-Rybak, Wioletta

2017-12-01

Daptomycin is a cyclic lipopeptide that is bactericidal against Staphylococcus aureus , including methicillin-resistant S. aureus (MRSA), vancomycin-intermediate S. aureus (VISA) and vancomycin-resistant S. aureus (VRSA) strains. Daptomycin exerts its antimicrobial effect by a calcium-dependent interaction with the cytoplasmic membrane resulting in depolarization, ion loss and rapid cell death. Unfortunately, loss of daptomycin susceptibility in S. aureus in the clinical setting has been noted. To evaluate the susceptibility profile to daptomycin among S. aureus strains isloted from patients with atopic dermatitis (AD). Another point was to correlate the results obtained by broth microdilution method and Etest, which is commonly applied in clinical setting. One hundred patients with the diagnosis of atopic dermatitis were microbiologically assessed for the carriage of S. aureus . Antimicrobial susceptibility tests were performed using broth-microdilution (BMD) and Etests for daptomycin. Staphylococcus aureus strains were isolated from the majority of our patients, either from the skin (73%) or the anterior nares (75%). Six of the 100 nasal swabs (6%) and 5 of the 100 skin swabs (5%) were positive for methicillin-resistant Staphylococcus aureus (MRSA). A total of 81 of 148 (54.7%) daptomycin non-susceptible isolates of S. aureus were identified by BMD. Only 19 of 81 were also classified as non-susceptible by Etest. Clinicians and microbiologists should be aware of the possibility of the emergence of daptomycin non-susceptibility (or increase in minimal inhibitory concentration) during prolonged therapy and closely monitor the susceptibility of persisting isolates that might be recovered during therapy.

Microstructures as IR-sensors with Staphylococcus aureus bacteria

NASA Astrophysics Data System (ADS)

Baikova, T. V.; Danilov, P. A.; Gonchukov, S. A.; Yermachenko, V. M.; Ionin, A. A.; Khmelnitskii, R. A.; Kudryashov, S. I.; Nguyen, T. T. H.; Rudenko, A. A.; Saraeva, I. N.; Svistunova, T. S.; Zayarny, D. A.

2017-09-01

Using a micro-hole grating in a supported silver film as a laser-fabricated novel optical platform for surface-enhanced IR absoprtion/reflection spectroscopy, characteristic absorption bands of Staphylococcus aureus, especially - its buried carotenoid fragments - were detected in FT-IR spectra with 10-fold analytical enhancement, paving the way to spectral express-identification of the pathogenic microorganisms.

[Staphylococcus aureus infection in Apis mellifera L. (honeybees)].

PubMed

Keskin, N

1989-07-01

The causative agent of American foulbrood is Bacillus larvae, the causes of the European foulbrood diseases are Streptococcus pluton and Bacillus alvei and the causes of the septicemia are Pseudomonas apiseptica and Escherichia coli in honeybees (Apis mellifera). Apart from the above causative agents in this study, Staphylococcus aureus has been isolated and identified from honeybees (Apis mellifera).

Mechanisms of antibiotic resistance in Staphylococcus aureus.

PubMed

Pantosti, Annalisa; Sanchini, Andrea; Monaco, Monica

2007-06-01

Staphylococcus aureus can exemplify better than any other human pathogen the adaptive evolution of bacteria in the antibiotic era, as it has demonstrated a unique ability to quickly respond to each new antibiotic with the development of a resistance mechanism, starting with penicillin and methicillin, until the most recent, linezolid and daptomycin. Resistance mechanisms include enzymatic inactivation of the antibiotic (penicillinase and aminoglycoside-modification enzymes), alteration of the target with decreased affinity for the antibiotic (notable examples being penicillin-binding protein 2a of methicillin-resistant S. aureus and D-Ala-D-Lac of peptidoglycan precursors of vancomycin-resistant strains), trapping of the antibiotic (for vancomycin and possibly daptomycin) and efflux pumps (fluoroquinolones and tetracycline). Complex genetic arrays (staphylococcal chromosomal cassette mec elements or the vanA operon) have been acquired by S. aureus through horizontal gene transfer, while resistance to other antibiotics, including some of the most recent ones (e.g., fluoroquinolones, linezolid and daptomycin) have developed through spontaneous mutations and positive selection. Detection of the resistance mechanisms and their genetic basis is an important support to antibiotic susceptibility surveillance in S. aureus.

Superantigens Modulate Bacterial Density during Staphylococcus aureus Nasal Colonization

PubMed Central

Xu, Stacey X.; Kasper, Katherine J.; Zeppa, Joseph J.; McCormick, John K.

2015-01-01

Superantigens (SAgs) are potent microbial toxins that function to activate large numbers of T cells in a T cell receptor (TCR) Vβ-specific manner, resulting in excessive immune system activation. Staphylococcus aureus possesses a large repertoire of distinct SAgs, and in the context of host-pathogen interactions, staphylococcal SAg research has focused primarily on the role of these toxins in severe and invasive diseases. However, the contribution of SAgs to colonization by S. aureus remains unclear. We developed a two-week nasal colonization model using SAg-sensitive transgenic mice expressing HLA-DR4, and evaluated the role of SAgs using two well-studied stains of S. aureus. S. aureus Newman produces relatively low levels of staphylococcal enterotoxin A (SEA), and although we did not detect significant TCR-Vβ specific changes during wild-type S. aureus Newman colonization, S. aureus Newman Δsea established transiently higher bacterial loads in the nose. S. aureus COL produces relatively high levels of staphylococcal enterotoxin B (SEB), and colonization with wild-type S. aureus COL resulted in clear Vβ8-specific T cell skewing responses. S. aureus COL Δseb established consistently higher bacterial loads in the nose. These data suggest that staphylococcal SAgs may be involved in regulating bacterial densities during nasal colonization. PMID:26008236

Identification of Infantile Diarrhea Caused by Breast Milk-Transmitted Staphylococcus aureus Infection.

PubMed

Chen, Zhong; Pan, Wei-Guang; Xian, Wei-Yi; Cheng, Hang; Zheng, Jin-Xin; Hu, Qing-Hua; Yu, Zhi-Jian; Deng, Qi-Wen

2016-10-01

Staphylococcus aureus is a well-known organism which is responsible for a variety of human infectious diseases including skin infections, pneumonia, bacteremia, and endocarditis. Few of the microorganisms can be transmitted from mother to the newborn or infant by milk breastfeeding. This study aims to identify transmission of S. aureus from healthy, lactating mothers to their infants by breastfeeding. Stool specimens of diarrheal infants and breast milk of their mother (totally three pairs) were collected and six Staphylococcus aureus isolates were cultured positively. Homology and molecular characters of isolated strains were tested using pulsed-field gel electrophoresis (PFGE), spa typing, and multilocus sequence typing. Furthermore, toxin genes detection was also performed. Each pair of isolates has the same PFGE type and spa type. Four Sequence types (STs) were found among all the isolates; they are ST15, ST188, and ST59, respectively. Among the strains, seb, sec, and tst genes were found, and all were negative for pvl gene. The homology of the S. aureus strains isolated from the infants' stool and the mothers' milk was genetically demonstrated, which indicated that breastfeeding may be important in the transmission of S. aureus infection, and the character of S. aureus needed to be further evaluated.

Emerging Functions for the Staphylococcus aureus RNome

PubMed Central

Felden, Brice

2013-01-01

Staphylococcus aureus is a leading pathogen for animals and humans, not only being one of the most frequently isolated bacteria in hospital-associated infections but also causing diseases in the community. To coordinate the expression of its numerous virulence genes for growth and survival, S. aureus uses various signalling pathways that include two-component regulatory systems, transcription factors, and also around 250 regulatory RNAs. Biological roles have only been determined for a handful of these sRNAs, including cis, trans, and cis-trans acting RNAs, some internally encoding small, functional peptides and others possessing dual or multiple functions. Here we put forward an inventory of these fascinating sRNAs; the proteins involved in their activities; and those involved in stress response, metabolisms, and virulence. PMID:24348246

A colloidal gold nanoparticle-based immunochromatographic test strip for rapid and convenient detection of Staphylococcus aureus.

PubMed

Niu, Kaili; Zheng, Xiaoping; Huang, Chusen; Xul, Kuan; Zhi, Yuan; Shen, Hebai; Jia, Nengqin

2014-07-01

An immunochromatographic test strip using gold nanoparticles-staphylococcus aureus monoclonal antibody conjugates was developed for the rapid and convenient detection of staphylococcus aureus based on a double-antibody sandwich format. The detection limit and the detection rate of this test strip is 10(3) CFU /mL and 98.7%, respectively. It could be used for the rapid detection of staphylococcus aureus in food and the results can be visually identified by the naked eye within 10 min. Compared with conventional bacterial detection methods, this developed immunochromatographic assay based test strip has several advantages including simple, fast, low-cost, favorable sensitivity and specificity, exhibiting a great potential for application in food safety control systems and clinical diagnosis.

Molecular characterization of endocarditis-associated Staphylococcus aureus.

PubMed

Nethercott, Cara; Mabbett, Amanda N; Totsika, Makrina; Peters, Paul; Ortiz, Juan C; Nimmo, Graeme R; Coombs, Geoffrey W; Walker, Mark J; Schembri, Mark A

2013-07-01

Infective endocarditis (IE) is a life-threatening infection of the heart endothelium and valves. Staphylococcus aureus is a predominant cause of severe IE and is frequently associated with infections in health care settings and device-related infections. Multilocus sequence typing (MLST), spa typing, and virulence gene microarrays are frequently used to classify S. aureus clinical isolates. This study examined the utility of these typing tools to investigate S. aureus epidemiology associated with IE. Ninety-seven S. aureus isolates were collected from patients diagnosed with (i) IE, (ii) bloodstream infection related to medical devices, (iii) bloodstream infection not related to medical devices, and (iv) skin or soft-tissue infections. The MLST clonal complex (CC) for each isolate was determined and compared to the CCs of members of the S. aureus population by eBURST analysis. The spa type of all isolates was also determined. A null model was used to determine correlations of IE with CC and spa type. DNA microarray analysis was performed, and a permutational analysis of multivariate variance (PERMANOVA) and principal coordinates analysis were conducted to identify genotypic differences between IE and non-IE strains. CC12, CC20, and spa type t160 were significantly associated with IE S. aureus. A subset of virulence-associated genes and alleles, including genes encoding staphylococcal superantigen-like proteins, fibrinogen-binding protein, and a leukocidin subunit, also significantly correlated with IE isolates. MLST, spa typing, and microarray analysis are promising tools for monitoring S. aureus epidemiology associated with IE. Further research to determine a role for the S. aureus IE-associated virulence genes identified in this study is warranted.

Molecular Characterization of Endocarditis-Associated Staphylococcus aureus

PubMed Central

Nethercott, Cara; Mabbett, Amanda N.; Totsika, Makrina; Peters, Paul; Ortiz, Juan C.; Nimmo, Graeme R.; Coombs, Geoffrey W.

2013-01-01

Infective endocarditis (IE) is a life-threatening infection of the heart endothelium and valves. Staphylococcus aureus is a predominant cause of severe IE and is frequently associated with infections in health care settings and device-related infections. Multilocus sequence typing (MLST), spa typing, and virulence gene microarrays are frequently used to classify S. aureus clinical isolates. This study examined the utility of these typing tools to investigate S. aureus epidemiology associated with IE. Ninety-seven S. aureus isolates were collected from patients diagnosed with (i) IE, (ii) bloodstream infection related to medical devices, (iii) bloodstream infection not related to medical devices, and (iv) skin or soft-tissue infections. The MLST clonal complex (CC) for each isolate was determined and compared to the CCs of members of the S. aureus population by eBURST analysis. The spa type of all isolates was also determined. A null model was used to determine correlations of IE with CC and spa type. DNA microarray analysis was performed, and a permutational analysis of multivariate variance (PERMANOVA) and principal coordinates analysis were conducted to identify genotypic differences between IE and non-IE strains. CC12, CC20, and spa type t160 were significantly associated with IE S. aureus. A subset of virulence-associated genes and alleles, including genes encoding staphylococcal superantigen-like proteins, fibrinogen-binding protein, and a leukocidin subunit, also significantly correlated with IE isolates. MLST, spa typing, and microarray analysis are promising tools for monitoring S. aureus epidemiology associated with IE. Further research to determine a role for the S. aureus IE-associated virulence genes identified in this study is warranted. PMID:23616460

Staphylococcus aureus food-poisoning outbreak associated with the consumption of ice-cream.

PubMed

Fetsch, A; Contzen, M; Hartelt, K; Kleiser, A; Maassen, S; Rau, J; Kraushaar, B; Layer, F; Strommenger, B

2014-09-18

In April 2013, a food poisoning outbreak caused by staphylococcal enterotoxins (SEs) in ice-cream occurred in Freiburg, Germany, among the 31 participants of a christening party. Of the 13 cases, seven were hospitalized or obtained ambulatory treatment. Different types of ice-cream, which was freshly produced at the hotel where the party took place, were found to contain SE and high amounts of coagulase positive staphylococci. Enterotoxigenic Staphylococcus aureus strains isolated from ice-cream and human cases were of the same spa-type (t127), harboured the sea gene and displayed identical phenotypic resistance-, Fourier transform infrared spectroscopy- (FT-IR) and microarray-profiles. Despite the strong microbiological and epidemiological evidence of ice-cream being the incriminated food vehicle of the outbreak, a common source of S. aureus from the ice-cream could not be deduced. As none of the employees carried the outbreak strain, either the equipment used for the production of the ice-cream or a contaminated ingredient is the most likely introduction source. Copyright © 2014 Elsevier B.V. All rights reserved.

Following Pathogen Development and Gene Expression in a Food Ecosystem: the Case of a Staphylococcus aureus Isolate in Cheese

PubMed Central

Aigle, Marina; Fleurot, Renaud; Darrigo, Claire; Hennekinne, Jacques-Antoine; Gruss, Alexandra; Borezée-Durant, Elise; Delacroix-Buchet, Agnès

2014-01-01

Human intoxication or infection due to bacterial food contamination constitutes an economic challenge and a public health problem. Information on the in situ distribution and expression of pathogens responsible for this risk is to date lacking, largely because of technical bottlenecks in detecting signals from minority bacterial populations within a complex microbial and physicochemical ecosystem. We simulated the contamination of a real high-risk cheese with a natural food isolate of Staphylococcus aureus, an enterotoxin-producing pathogen responsible for food poisoning. To overcome the problem of a detection limit in a solid matrix, we chose to work with a fluorescent reporter (superfolder green fluorescent protein) that would allow spatiotemporal monitoring of S. aureus populations and targeted gene expression. The combination of complementary techniques revealed that S. aureus localizes preferentially on the cheese surface during ripening. Immunochemistry and confocal laser scanning microscopy enabled us to visualize, in a single image, dairy bacteria and pathogen populations, virulence gene expression, and the toxin produced. This procedure is readily applicable to other genes of interest, other bacteria, and different types of food matrices. PMID:24928871

Synergistic action between sisomicin and mezlocillin against gram-negative bacteria and Staphylococcus aureus.

PubMed

Soares, L A; Trabulsi, L R

1979-01-01

The combined effect of sisomicin and 6-[(R)-2-[3-methylsulfonyl-2-oxo-imidazolidine-1-carboxamido]-2-phenyl-acetamido-a1-penicillanic acid sodium salt (mezlocillin, Baypen) was studied against 50 bacterial strains, including Pseudomonas aeruginosa, Proteus spp. Klebsiella-Enterobacter, E. coli and Staphylococcus aureus. No antagonism or indifference was detected with the strains studied. Both antibiotics were synergistic against 62% of the strains, and partially synergistic against 38%. Out of the bacteria studied, Staphylococcus aureus was the most susceptible to the combined action of sisomicin and mezlocillin.

Neutrophil evasion strategies by Streptococcus pneumoniae and Staphylococcus aureus.

PubMed

Lewis, Megan L; Surewaard, Bas G J

2018-03-01

Humans are well equipped to defend themselves against bacteria. The innate immune system employs diverse mechanisms to recognize, control and initiate a response that can destroy millions of different microbes. Microbes that evade the sophisticated innate immune system are able to escape detection and could become pathogens. The pathogens Streptococcus pneumoniae and Staphylococcus aureus are particularly successful due to the development of a wide variety of virulence strategies for bacterial pathogenesis and they invest significant efforts towards mechanisms that allow for neutrophil evasion. Neutrophils are a primary cellular defense and can rapidly kill invading microbes, which is an indispensable function for maintaining host health. This review compares the key features of Streptococcus pneumoniae and Staphylococcus aureus in epidemiology, with a specific focus on virulence mechanisms utilized to evade neutrophils in bacterial pathogenesis. It is important to understand the complex interactions between pathogenic bacteria and neutrophils so that we can disrupt the ability of pathogens to cause disease.

Are Phage Lytic Proteins the Secret Weapon To Kill Staphylococcus aureus?

PubMed

Gutiérrez, Diana; Fernández, Lucía; Rodríguez, Ana; García, Pilar

2018-01-23

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most threatening microorganisms for global human health. The current strategies to reduce the impact of S. aureus include a restrictive control of worldwide antibiotic use, prophylactic measures to hinder contamination, and the search for novel antimicrobials to treat human and animal infections caused by this bacterium. The last strategy is currently the focus of considerable research. In this regard, phage lytic proteins (endolysins and virion-associated peptidoglycan hydrolases [VAPGHs]) have been proposed as suitable candidates. Indeed, these proteins display narrow-spectrum antimicrobial activity and a virtual lack of bacterial-resistance development. Additionally, the therapeutic use of phage lytic proteins in S. aureus animal infection models is yielding promising results, showing good efficacy without apparent side effects. Nonetheless, human clinical trials are still in progress, and data are not available yet. This minireview also analyzes the main obstacles for introducing phage lytic proteins as human therapeutics against S. aureus infections. Besides the common technological problems derived from large-scale production of therapeutic proteins, a major setback is the lack of a proper legal framework regulating their use. In that sense, the relevant health authorities should urgently have a timely discussion about these new antimicrobials. On the other hand, the research community should provide data to dispel any doubts regarding their efficacy and safety. Overall, the appropriate scientific data and regulatory framework will encourage pharmaceutical companies to invest in these promising antimicrobials. Copyright © 2018 Gutiérrez et al.

Molecular Epidemiology of Staphylococcus aureus Colonization in 2 Long-Term Care Facilities

PubMed Central

Mody, Lona; Flannery, Erica; Bielaczyc, Andrew; Bradley, Suzanne F.

2012-01-01

Persistent colonization with Staphylococcus aureus was assessed in 22 nursing home residents. Eighteen residents (82%) remained colonized with the same strain found at baseline; 6 (33%) of 18 residents transiently acquired a new strain. Four residents (18%) acquired a new persistent strain. Residents colonized with methicillin-resistant S. aureus were more likely to acquire a new strain (67%) than were residents colonized with methicillin-susceptible S. aureus (20%) (P =.04). PMID:16465644

Staphylococcus aureus biofilms: recent developments in biofilm dispersal.

PubMed

Lister, Jessica L; Horswill, Alexander R

2014-01-01

Staphylococcus aureus is a major cause of nosocomial and community-acquired infections and represents a significant burden on the healthcare system. S. aureus attachment to medical implants and host tissue, and the establishment of a mature biofilm, play an important role in the persistence of chronic infections. The formation of a biofilm, and encasement of cells in a polymer-based matrix, decreases the susceptibility to antimicrobials and immune defenses, making these infections difficult to eradicate. During infection, dispersal of cells from the biofilm can result in spread to secondary sites and worsening of the infection. In this review, we discuss the current understanding of the pathways behind biofilm dispersal in S. aureus, with a focus on enzymatic and newly described broad-spectrum dispersal mechanisms. Additionally, we explore potential applications of dispersal in the treatment of biofilm-mediated infections.

Community-acquired methicillin-resistant Staphylococcus aureus can persist in the throat.

PubMed

Hamdan-Partida, Aida; González-García, Samuel; de la Rosa García, Estela; Bustos-Martínez, Jaime

2018-06-01

Colonization by Staphylococcus aureus is an important factor in infections caused by this microorganism. Among the colonization niches of staphylococci are the nose, skin, intestinal tract, and, recently, the throat has been given relevance. Infections caused by community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) can be fatal. Persistence of S. aureus is an important process in the pathogenesis of this microorganism and must be studied. The aim of this study was to determine the persistence of S. aureus in the throat, and characterized the strains. We studied the persistence of S. aureus for 6 years in the throat of apparently healthy people. The isolated strains from the persistent carriers were characterized through PFGE, spa-typing, SCCmec typing, resistance to methicillin, presence of virulence genes (adhesins and toxins), and the formation of biofilm. We found persistent and intermittent carriers of S. aureus in the throat, with methicillin-sensitive (MSSA), methicillin-resistant (MRSA) strains, and confirmed for the first time that CA-MRSA colonizes this niche. These strains can colonize persistently the throat for four years or more. Typification of strains through PFGE and spa-typing revealed that some carriers present the same strain, whereas others present different strains along the period of persistence. Almost all strains induced a strong biofilm formation. All strains presented adhesin and toxin genes, but no shared genotype was found. We conclude that S. aureus, including CA-MRSA strains, can remain persistently in the throat, finding a wide variability among the persistent strains. Copyright © 2018 Elsevier GmbH. All rights reserved.

Cross-Talk between Staphylococcus aureus and Other Staphylococcal Species via the agr Quorum Sensing System

PubMed Central

Canovas, Jaime; Baldry, Mara; Bojer, Martin S.; Andersen, Paal S.; Gless, Bengt H.; Grzeskowiak, Piotr K.; Stegger, Marc; Damborg, Peter; Olsen, Christian A.; Ingmer, Hanne

2016-01-01

Staphylococci are associated with both humans and animals. While most are non-pathogenic colonizers, Staphylococcus aureus is an opportunistic pathogen capable of causing severe infections. S. aureus virulence is controlled by the agr quorum sensing system responding to secreted auto-inducing peptides (AIPs) sensed by AgrC, a two component histidine kinase. agr loci are found also in other staphylococcal species and for Staphylococcus epidermidis, the encoded AIP represses expression of agr regulated virulence genes in S. aureus. In this study we aimed to better understand the interaction between staphylococci and S. aureus, and show that this interaction may eventually lead to the identification of new anti-virulence candidates to target S. aureus infections. Here we show that culture supernatants of 37 out of 52 staphylococcal isolates representing 17 different species inhibit S. aureus agr. The dog pathogen, Staphylococcus schleiferi, expressed the most potent inhibitory activity and was active against all four agr classes found in S. aureus. By employing a S. aureus strain encoding a constitutively active AIP receptor we show that the activity is mediated via agr. Subsequent cloning and heterologous expression of the S. schleiferi AIP in S. aureus demonstrated that this molecule was likely responsible for the inhibitory activity, and further proof was provided when pure synthetic S. schleiferi AIP was able to completely abolish agr induction of an S. aureus reporter strain. To assess impact on S. aureus virulence, we co-inoculated S. aureus and S. schleiferi in vivo in the Galleria mellonella wax moth larva, and found that expression of key S. aureus virulence factors was abrogated. Our data show that the S. aureus agr locus is highly responsive to other staphylococcal species suggesting that agr is an inter-species communication system. Based on these results we speculate that interactions between S. aureus and other colonizing staphylococci will significantly

Novel application for the prevention and treatment of Staphylococcus aureus biofilm formation

NASA Astrophysics Data System (ADS)

Traba, Christian

Formation of bacterial biofilms at solid-liquid interfaces creates numerous problems in both industrial and biomedical sciences. In this dissertation, the application of plasma from two very different facets was studied. In part one, the susceptibility of pre-formed Staphylococcus aureus biofilms on biomaterials to different plasmas was investigated. It was found that the distinct chemical/physical properties of plasmas generated from oxygen, nitrogen, and argon all demonstrated very potent but very different anti-biofilm mechanisms of action. An in depth analysis of these results show: 1) different reactive species produced in each plasma demonstrate specific activity, and 2) the commonly associated etching effect could be manipulated and even controlled, depending on experimental conditions and the discharge gas. These studies provide insights into the anti-biofilm mechanisms of plasma as well as the effects of different reactive species on biofilm inactivation. Under experimental parameters, bacterial cells in Staphylococcus aureus biofilms were killed (>99.9%) by plasmas within minutes of exposure and no bacteria nor biofilm re-growth from discharge gas treated biofilms was observed throughout the life-span of the re-growth experiment. The decontamination ability of plasmas for the treatment of biofilm related infections on biomedical materials was confirmed and novel applications involving the use of low power argon and oxygen for the treatment of biofilm contaminated biomaterials and indwelling devices is proposed. The second facet of this dissertation explores the interaction between biofilm forming Staphylococcus aureus bacteria on different antibacterial/anti-biofilm surfaces. The antibiotic-free anti-fouling surfaces constructed in this study were generated from the plasma-assisted graft polymerization technique. These sophisticated surfaces were stable, biocompatible and capable of preventing biofilm formation on biomaterials and medical devices. Under

Antimicrobials from human skin commensal bacteria protect against Staphylococcus aureus and are deficient in atopic dermatitis

PubMed Central

Nakatsuji, Teruaki; Chen, Tiffany H.; Narala, Saisindhu; Chun, Kimberly A.; Two, Aimee M.; Yun, Tong; Shafiq, Faiza; Kotol, Paul F.; Bouslimani, Amina; Melnik, Alexey V.; Latif, Haythem; Kim, Ji-Nu; Lockhart, Alexandre; Artis, Keli; David, Gloria; Taylor, Patricia; Streib, Joanne; Dorrestein, Pieter C.; Grier, Alex; Gill, Steven R.; Zengler, Karsten; Hata, Tissa R.; Leung, Donald Y. M.; Gallo, Richard L.

2017-01-01

The microbiome can promote or disrupt human health by influencing both adaptive and innate immune functions. We tested whether bacteria that normally reside on human skin participate in host defense by killing Staphylococcus aureus, a pathogen commonly found in patients with atopic dermatitis (AD) and an important factor that exacerbates this disease. High-throughput screening for antimicrobial activity against S.aureus was performed on isolates of coagulase-negative Staphylococcus (CoNS) collected from the skin of healthy and AD subjects. CoNS strains with antimicrobial activity were common on the normal population but rare on AD subjects. A low frequency of strains with antimicrobial activity correlated with colonization by S.aureus. The antimicrobial activity was identified as previously unknown antimicrobial peptides (AMPs) produced by CoNS species including Staphylococcus epidermidis and Staphylococcus hominis. These AMPs were strain-specific, highly potent, selectively killed S.aureus, and synergized with the human AMP LL-37. Application of these CoNS strains to mice confirmed their defense function in vivo relative to application of nonactive strains. Strikingly, reintroduction of antimicrobial CoNS strains to human subjects with AD decreased colonization by S.aureus. These findings show how commensal skin bacteria protect against pathogens and demonstrate how dysbiosis of the skin microbiome can lead to disease. PMID:28228596

Staphylococcus aureus epidemic in a neonatal nursery: a strategy of infection control.

PubMed

Bertini, Giovanna; Nicoletti, PierLuigi; Scopetti, Franca; Manoocher, Pourshaban; Dani, Carlo; Orefici, Graziella

2006-08-01

The risk of nosocomial infection due to Staphylococcus aureus in fullterm newborns is higher under hospital conditions where there are overcrowded nurseries and inadequate infection control techniques. We report on an outbreak of skin infection in a Maternity Nursery (May 21, 2000) and the measures undertaken to bring the epidemic under control. These measures included: separating neonates already present in the nursery on August 23, 2000 from ones newly arriving by creating two different cohorts, one of neonates born before this date and one of neonates born later; restricting healthcare workers caring for S. aureus- infected infants from working with non-infected infants; disallowing carrier healthcare workers from caring for patients; introducing contact and droplet precautions (including the routine use of gowns, gloves, and mask); ensuring appropriate disinfection of potential sources of contamination. A representative number of isolates were typed by genomic DNA restriction length polymorphism analysis by means of pulsed-field gel electrophoresis (PFGE). Among the 227 cases of skin lesions, microbiological laboratory analyses confirmed that 175 were staphylococcal infections. The outbreak showed a gradual reduction in magnitude when the overcrowding of the Nursery was reduced by separating the newborns into the two different Nurseries (two cohorts). The genotyping of the strains by PFGE confirmed the nurse-to-newborn transmission of S. aureus. The measures adopted for controlling the S. aureus outbreak can, in retrospect, be assessed to have been very effective.

SATRAT: Staphylococcus aureus transcript regulatory network analysis tool.

PubMed

Gopal, Tamilselvi; Nagarajan, Vijayaraj; Elasri, Mohamed O

2015-01-01

Staphylococcus aureus is a commensal organism that primarily colonizes the nose of healthy individuals. S. aureus causes a spectrum of infections that range from skin and soft-tissue infections to fatal invasive diseases. S. aureus uses a large number of virulence factors that are regulated in a coordinated fashion. The complex regulatory mechanisms have been investigated in numerous high-throughput experiments. Access to this data is critical to studying this pathogen. Previously, we developed a compilation of microarray experimental data to enable researchers to search, browse, compare, and contrast transcript profiles. We have substantially updated this database and have built a novel exploratory tool-SATRAT-the S. aureus transcript regulatory network analysis tool, based on the updated database. This tool is capable of performing deep searches using a query and generating an interactive regulatory network based on associations among the regulators of any query gene. We believe this integrated regulatory network analysis tool would help researchers explore the missing links and identify novel pathways that regulate virulence in S. aureus. Also, the data model and the network generation code used to build this resource is open sourced, enabling researchers to build similar resources for other bacterial systems.

Metabolic activity, urease production, antibiotic resistance and virulence in dual species biofilms of Staphylococcus epidermidis and Staphylococcus aureus.

PubMed

Vandecandelaere, Ilse; Van Nieuwerburgh, Filip; Deforce, Dieter; Coenye, Tom

2017-01-01

In this paper, the metabolic activity in single and dual species biofilms of Staphylococcus epidermidis and Staphylococcus aureus isolates was investigated. Our results demonstrated that there was less metabolic activity in dual species biofilms compared to S. aureus biofilms. However, this was not observed if S. aureus and S. epidermidis were obtained from the same sample. The largest effect on metabolic activity was observed in biofilms of S. aureus Mu50 and S. epidermidis ET-024. A transcriptomic analysis of these dual species biofilms showed that urease genes and genes encoding proteins involved in metabolism were downregulated in comparison to monospecies biofilms. These results were subsequently confirmed by phenotypic assays. As metabolic activity is related to acid production, the pH in dual species biofilms was slightly higher compared to S. aureus Mu50 biofilms. Our results showed that S. epidermidis ET-024 in dual species biofilms inhibits metabolic activity of S. aureus Mu50, leading to less acid production. As a consequence, less urease activity is required to compensate for low pH. Importantly, this effect was biofilm-specific. Also S. aureus Mu50 genes encoding virulence-associated proteins (Spa, SplF and Dps) were upregulated in dual species biofilms compared to monospecies biofilms and using Caenorhabditis elegans infection assays, we demonstrated that more nematodes survived when co-infected with S. epidermidis ET-024 and S. aureus mutants lacking functional spa, splF or dps genes, compared to nematodes infected with S. epidermidis ET-024 and wild- type S. aureus. Finally, S. epidermidis ET-024 genes encoding resistance to oxacillin, erythromycin and tobramycin were upregulated in dual species biofilms and increased resistance was subsequently confirmed. Our data indicate that both species in dual species biofilms of S. epidermidis and S. aureus influence each other's behavior, but additional studies are required necessary to elucidate the exact

Construction of Stable Fluorescent Reporter Plasmids for Use in Staphylococcus aureus

PubMed Central

Rodriguez, Michelle D.; Paul, Zubin; Wood, Charles E.; Rice, Kelly C.; Triplett, Eric W.

2017-01-01

Here, the genes encoding three different fluorescent proteins were cloned into the stably maintained Staphylococcus aureus shuttle vector pKK30. The resulting plasmids were transformed into two S. aureus strains; SH1000 and RN4220. Stability assays illustrated that the three recombinant plasmids retained near 100% maintenance in vitro for 160 generations. S. aureus strain SH1000 expressing green fluorescent protein was then inoculated in an ovine model and in vivo stability for 6 days was demonstrated. In essence, these reporter plasmids represent a useful set of tools for dynamic imaging studies in S. aureus. These three reporter plasmids are available through BEI Resources. PMID:29312199

Construction of Stable Fluorescent Reporter Plasmids for Use in Staphylococcus aureus.

PubMed

Rodriguez, Michelle D; Paul, Zubin; Wood, Charles E; Rice, Kelly C; Triplett, Eric W

2017-01-01

Here, the genes encoding three different fluorescent proteins were cloned into the stably maintained Staphylococcus aureus shuttle vector pKK30. The resulting plasmids were transformed into two S. aureus strains; SH1000 and RN4220. Stability assays illustrated that the three recombinant plasmids retained near 100% maintenance in vitro for 160 generations. S. aureus strain SH1000 expressing green fluorescent protein was then inoculated in an ovine model and in vivo stability for 6 days was demonstrated. In essence, these reporter plasmids represent a useful set of tools for dynamic imaging studies in S. aureus . These three reporter plasmids are available through BEI Resources.

Inhibitory Effects of Pterodon emarginatus Bean Oil and Extract on Staphylococcus aureus.

PubMed

Mendes, V S; Sant'Anna, J B; Oliveira, S C C; Maldonade, Iriani Rodrigues; Machado, Eleuza Rodrigues

2017-01-01

Pterodon emarginatus is a tree of the Brazilian Savannah. The beans of this tree are used in folk medicine as anti-inflammatory preparations, especially for infections caused by Staphylococcus aureus . These bacteria can cause simple infections or serious illnesses such as pneumonia, meningitis, endocarditis, toxic shock syndrome, septicemia, and others. This study had the goal of verifying the effect of the essential oil (OE) from P. emarginatus on the inhibition of S. aureus in culture medium, i.e., " in vitro " tests. The vegetable material was cut and crushed with a press. The OE was obtained by extraction using hexane, alcohol, and water. The P. emarginatus extracts obtained were used to evaluate the antimicrobial effect on S. aureus (ATCC 25923) by tests of well diffusion, disc diffusion, and microdilution. The strain used in the assays was maintained in brain heart infusion broth and nutrient agar until testing. Afterward, the bacteria were spread on agar plates with Mueller-Hinton agar medium. In the wells and on the paper discs, the OE suspensions were placed in the following volumes: 10, 15, 20, 25, 30, 40, and 80 μL and subsequently they were incubated at 35°C ± 2°C. After 24 h, the number of colony-forming unit was determined. Pure OE and hydroalcoholic extract inhibited the growth of S. aureus , while aqueous extract had no effect on bacterial growth in all microbial methods used. Thus, the present study showed the potential of sucupira-based extracts against S. aureus growth, opening new perspectives for the evaluation of these bioactive compounds as phytopharmaceutical products. Plant extract act as antimicrobials to prevent and reduce bacterial contaminationBeans of Pterodon emarginatus has antibacterial propertiesExtraction with different solvents might implicate on the rate of bacterial deathThe effect of different microbiological methods (well diffusion, disc diffusion and microdilution) was evaluated on reducing CFUThe results showed by MBC

[Differentiation of Staphylococcus aureus isolates based on phenotypical characters].

PubMed

Miedzobrodzki, Jacek; Małachowa, Natalia; Markiewski, Tomasz; Białecka, Anna; Kasprowicz, Andrzej

2008-06-30

Typing of Staphylococcus aureus isolates is a necessary procedure for monitoring the transmission of S. aureus among carriers and in epidemiology. Evaluation of the range of relationship among isolates rely on epidemiological markers and is possible because of the clonal character of S. aureus species. Effective typing shows the scheme of transmission of infection in a selected area, enables identifying the reservoir of the microorganism, and may enhance effective eradication. A set of typing methods for use in analyses of epidemiological correlations and the identification of S. aureus isolates is presented. The following methods of typing are described: biotyping, serotyping, antibiogram, protein electrophoresis, cell protein profiles (proteom), immunoblotting, multilocus enzyme electrophoresis (MLEE), zymotyping, and standard species identification of S. aureus in the diagnostic laboratory. Phenotyping methods for S. aureus isolates used in the past and today in epidemiological investigations and in analyses of correlations among S. aureus isolates are presented in this review. The presented methods use morphological characteristics, physiological properties, and chemical structures of the bacteria as criteria for typing. The precision of these standard methods is not always satisfactory as S. aureus strains with atypical biochemical characters have evolved recently. Therefore it is essential to introduce additional typing procedures using molecular biology methods without neglecting phenotypic methods.

Methicillin-resistant Staphylococcus aureus colonization of house officers.

PubMed

Barbosa, Anna A; Chapin, Kim; Mermel, Leonard A

2009-09-01

We performed a prospective prevalence survey of methicillin-resistant Staphylococcus aureus (MRSA) carriage in the nares of 50 medical and 50 surgical house officers. None of the 50 internal medicine house officers and 5 of the 50 general surgery house officers had MRSA nares colonization (P = .03). None of the MRSA isolates recovered from the surgical house officers were identical.

Effective application of multiple locus variable number of tandem repeats analysis to tracing Staphylococcus aureus in food-processing environment.

PubMed

Rešková, Z; Koreňová, J; Kuchta, T

2014-04-01

A total of 256 isolates of Staphylococcus aureus were isolated from 98 samples (34 swabs and 64 food samples) obtained from small or medium meat- and cheese-processing plants in Slovakia. The strains were genotypically characterized by multiple locus variable number of tandem repeats analysis (MLVA), involving multiplex polymerase chain reaction (PCR) with subsequent separation of the amplified DNA fragments by an automated flow-through gel electrophoresis. With the panel of isolates, MLVA produced 31 profile types, which was a sufficient discrimination to facilitate the description of spatial and temporal aspects of contamination. Further data on MLVA discrimination were obtained by typing a subpanel of strains by multiple locus sequence typing (MLST). MLVA coupled to automated electrophoresis proved to be an effective, comparatively fast and inexpensive method for tracing S. aureus contamination of food-processing factories. Subspecies genotyping of microbial contaminants in food-processing factories may facilitate identification of spatial and temporal aspects of the contamination. This may help to properly manage the process hygiene. With S. aureus, multiple locus variable number of tandem repeats analysis (MLVA) proved to be an effective method for the purpose, being sufficiently discriminative, yet comparatively fast and inexpensive. The application of automated flow-through gel electrophoresis to separation of DNA fragments produced by multiplex PCR helped to improve the accuracy and speed of the method. © 2013 The Society for Applied Microbiology.

The combination of osthole with baicalin protects mice from Staphylococcus aureus pneumonia.

PubMed

Liu, Shui; Liu, Bowen; Luo, Zhao-Qing; Qiu, Jiaming; Zhou, Xuan; Li, Gen; Zhang, Bing; Deng, Xuming; Yang, Zhenguo; Wang, Jianfeng

2017-01-01

We reported the inhibition of α-Hemolysin (Hla) production in methicillin-resistant Staphylococcus aureus USA300 by osthole and further investigated the combination of osthole and baicalin in the treatment of staphylococcal pneumonia. Using cytotoxicity assays and a mouse model of intranasal lung infection, we evaluated the effect of combined therapy. Our results suggest that the combination of osthole and baicalin alleviated S. aureus-mediated A549 cell injury and protected mice from S. aureus pneumonia.

Staphylococcus aureus Prostatic abscess: a clinical case report and a review of the literature.

PubMed

Carroll, David E; Marr, Ian; Huang, G Khai Lin; Holt, Deborah C; Tong, Steven Y C; Boutlis, Craig S

2017-07-21

Prostatic abscess is a rare complication of acute bacterial prostatitis and is most commonly caused by Enterobacteriaceae. We report on a case of prostatic abscess caused by Staphylococcus aureus and conduct a review of the literature. We present a case of S. aureus prostatic abscess that was successfully treated with a combination of antibiotic and surgical therapy. The isolate was non–multidrug-resistant, methicillin-resistant Staphylococcus aureus and was genotyped as clonal complex 5, an emerging regional clone that is trimethoprim resistant and Panton-Valentine leukocidin positive. This current case report is the first to describe the use of clindamycin step-down therapy. A literature review identified a further 39 cases of S. aureus prostatic abscesses, of which 26 were methicillin resistant. S. aureus is an uncommon cause of prostatic abscess. Optimal management includes both antibiotic therapy and surgical drainage. Our use of clindamycin as step-down therapy was guided by its excellent prostatic penetration.

Comparative evaluation of the association among enumeration methods and production of enterotoxins in food-derived Staphylococcus aureus.

PubMed

Zhang, Chi; Zhang, Deqin; Yang, Jun; Zhou, Jungui; Hu, Qilong; Ling, Rui; Dong, Mingsheng

2012-01-01

Staphylococcal food poisoning is one of the most common foodborne diseases worldwide; it results from the ingestion of staphylococcal enterotoxins (SEs) in food, mainly Staphylococcus aureus. This study investigated the statistical relationships among morphological enumerations of food-derived S. aureus and production of SEs using different methodologies. Food samples naturally contaminated with coagulase-positive S. aureus were submitted for enumeration on Baird-Parker (BP) agar, Rabbit Plasma Fibrinogen agar (RPFA), and Petrifilm Staph Express count system (STX), and the morphologically typical colonies were isolated for VIDAS and real-time (RT) PCR tests. RPFA and STX displayed better performance for the enumeration of SE-positive S. aureus when compared with BP, including higher frequencies of SE-positive isolates and better correlation indices between typical and SE-positive counts. Among all the evaluated culture media, no significant difference (P > 0.05) was shown on the frequencies of typical colonies that carried 11 individual se genes. In addition, results for SE identification between VIDAS and RT-PCR assay were unparalleled. These data will be valuable for the selection of methods for inspection of food-derived S. aureus.

Comparison of four methods for rapid identification of Staphylococcus aureus directly from BACTEC 9240 blood culture system.

PubMed

Ozen, N S; Ogunc, D; Mutlu, D; Ongut, G; Baysan, B O; Gunseren, F

2011-01-01

Differentiation of Staphylococcus aureus (S. aureus) from coagulase-negative staphylococci is very important in blood stream infections. Identification of S. aureus and coagulase-negative staphylococci (CoNS) from blood cultures takes generally 18-24 h after positive signaling on continuously monitored automated blood culture system. In this study, we evaluated the performance of tube coagulase test (TCT), slide agglutination test (Dry Spot Staphytect Plus), conventional polymerase chain reaction (PCR) and LightCycler Staphylococcus MGrade kit directly from blood culture bottles to achieve rapid identification of S. aureus by using the BACTEC 9240 blood culture system. A total of 129 BACTEC 9240 bottles growing gram-positive cocci suggesting Staphylococci were tested directly from blood culture broths (BCBs) with TCT, Dry Spot Staphytect Plus, conventional PCR and LightCycler Staphylococcus MGrade kit for rapid identification of S. aureus. The sensitivities of the tests were 99, 68, 99 and 100%, respectively. Our results suggested that 2 h TCT was found to be simple and inexpensive method for the rapid identification of S. aureus directly from positive blood cultures.

Rapid Identification of Methicillin-Resistant Staphylococcus aureus (MRSA) by the Vitek MS Saramis system.

PubMed

Shan, Weiguang; Li, Jiaping; Fang, Ying; Wang, Xuan; Gu, Danxia; Zhang, Rong

2016-01-01

A rapid, sensitive, and accurate Vitek MS assay was developed to distinguish clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) from clinical isolates of methicillin-sensitive Staphylococcus aureus (MSSA) by developing an in-house knowledgebase of SuperSpectra. Three unique peaks, including peaks at 2305.6 and 3007.3 Da specific to MRSA, and 6816.7 Da specific to MSSA, were selected for differentiating MRSA and MSSA. This assay accurately identified 84 and 91% of clinical MRSA and MSSA strains out of the total 142 clinically acquired S. aureus strains that were tested. This method will greatly improve the efficiency of single clinical sample identification of MRSA, thereby facilitating a reduction in the transmission of MRSA in clinical settings.

Lysionotin attenuates Staphylococcus aureus pathogenicity by inhibiting α-toxin expression.

PubMed

Teng, Zihao; Shi, Dongxue; Liu, Huanyu; Shen, Ziying; Zha, Yonghong; Li, Wenhua; Deng, Xuming; Wang, Jianfeng

2017-09-01

α-Toxin, one of the best known pore-forming proteins produced by Staphylococcus aureus (S. aureus), is a critical virulence factor in multiple infections. The necessity of α-toxin for S. aureus pathogenicity suggests that this toxin is an important target for the development of a potential treatment strategy. In this study, we showed that lysionotin, a natural compound, can inhibit the hemolytic activity of culture supernatants by S. aureus by reducing α-toxin expression. Using real-time PCR analysis, we showed that transcription of hla (the gene encoding α-toxin) and agr (the locus regulating hla) was significantly inhibited by lysionotin. Lactate dehydrogenase and live/dead assays indicated that lysionotin effectively protected human alveolar epithelial cells against S. aureus, and in vivo studies also demonstrated that lysionotin can protect mice from pneumonia caused by S. aureus. These findings suggest that lysionotin is an efficient inhibitor of α-toxin expression and shows significant protection against S. aureus in vitro and in vivo. This study supports a potential strategy for the treatment of S. aureus infection by inhibiting the expression of virulence factors and indicates that lysionotin may be a potential treatment for S. aureus pneumonia.

Human-to-Dog Transmission of Methicillin-Resistant Staphylococcus aureus

PubMed Central

Wolfhagen, Maurice J.H.M.; Heck, Max E.O.C.; Wannet, Wim J.B.; Fluit, Ad C.

2004-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) was cultured from the nose of a healthy dog whose owner was colonized with MRSA while she worked in a Dutch nursing home. Pulsed-field gel electrophoresis and typing of the staphylococcal chromosome cassette mec (SCCmec) region showed that both MRSA strains were identical. PMID:15663871

Anti-biofilm formation of a novel stainless steel against Staphylococcus aureus.

PubMed

Nan, Li; Yang, Ke; Ren, Guogang

2015-06-01

Staphylococcus aureus (S. aureus) is a bacterium frequently found proliferating on metal surfaces such as stainless steels used in healthcare and food processing facilities. Past research has shown that a novel Cu-bearing 304 type stainless steel (304CuSS) exhibits excellent antibacterial ability (i.e. against S. aureus) in a short time period (24h.). This work was dedicated to investigate the 304CuSS's inhibition ability towards the S. aureus biofilm formation for an extended period of 7days after incubation. It was found that the antibacterial rate of the 304CuSS against sessile bacterial cells reached over 99.9% in comparison with the 304SS. The thickness and sizes of the biofilms on the 304SS surfaces increased markedly with period of contact, and thus expected higher risk of bio-contamination, indicated by the changes of surface free energy between biofilm and the steel surfaces. The results demonstrated that the 304CuSS exhibited strong inhibition on the growth and adherence of the biofilms. The surface free energy of the 304CuSS after contact with sessile bacterial cells was much lower than that of the 304SS towards the same culture times. The continuously dissolved Cu(2+) ions well demonstrated the dissolution ability of Cu-rich precipitates after exposure to S. aureus solution, from 3.1ppm (2days) to 4.5ppm (7days). For this to occur, a hypothesis mechanism might be established for 304CuSS in which the Cu(2+) ions were released from Cu-rich phases that bond with extracellular polymeric substances (EPS) of the microorganisms. And these inhibited the activities of cell protein/enzymes and effectively prevented planktonic bacterial cells attaching to the 304CuSS metal surface. Copyright © 2015. Published by Elsevier B.V.

Phage inactivation of Staphylococcus aureus in fresh and hard-type cheeses.

PubMed

Bueno, Edita; García, Pilar; Martínez, Beatriz; Rodríguez, Ana

2012-08-01

Bacteriophages are regarded as natural antibacterial agents in food since they are able to specifically infect and lyse food-borne pathogenic bacteria without disturbing the indigenous microbiota. Two Staphylococcus aureus obligately lytic bacteriophages (vB_SauS-phi-IPLA35 and vB_SauS-phi-SauS-IPLA88), previously isolated from the dairy environment, were evaluated for their potential as biocontrol agents against this pathogenic microorganism in both fresh and hard-type cheeses. Pasteurized milk was contaminated with S. aureus Sa9 (about 10(6) CFU/mL) and a cocktail of the two lytic phages (about 10(6) PFU/mL) was also added. For control purposes, cheeses were manufactured without addition of phages. In both types of cheeses, the presence of phages resulted in a notorious decrease of S. aureus viable counts during curdling. In test fresh cheeses, a reduction of 3.83 log CFU/g of S. aureus occurred in 3h compared with control cheese, and viable counts were under the detection limits after 6h. The staphylococcal strain was undetected in both test and control cheeses at the end of the curdling process (24 h) and, of note, no re-growth occurred during cold storage. In hard cheeses, the presence of phages resulted in a continuous reduction of staphylococcal counts. In curd, viable counts of S. aureus were reduced by 4.64 log CFU/g compared with the control cheeses. At the end of ripening, 1.24 log CFU/g of the staphylococcal strain was still detected in test cheeses whereas 6.73log CFU/g was present in control cheeses. Starter strains were not affected by the presence of phages in the cheese making processes and cheeses maintained their expected physico-chemical properties. Copyright © 2012 Elsevier B.V. All rights reserved.

Community-associated methicillin-resistant Staphylococcus aureus in college residential halls.

PubMed

Tonn, Katelynn; Ryan, Timothy J

2013-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) was once a predominantly hospital-acquired organism but community-associated MRSA (CA-MRSA) has become a concern in athletics, prisons, and other nonclinical closed populations. As such, college residential hall occupants and workers may be at elevated risk of spreading or contracting MRSA. Environmental samples were obtained to identify the occurrence of MRSA on surfaces in bathrooms of 15 university residential halls. Sterile swabs and BBL CHROMagar plates were used to sample seven categories of potentially contaminated surfaces in each location. Frequencies and descriptive statistics were prepared. All sites had at least one positive sample for MRSA, and shower floors displayed the greatest prevalence (50%). These results indicate areas for heightened sanitation, and illustrate CA-MRSA potential from such surfaces. The need for hygiene education of affected persons about skin and soft tissue infections like MRSA, and intervention opportunities for public health professionals, are discussed.

Semi Quantitative MALDI TOF for Antimicrobial Susceptibility Testing in Staphylococcus aureus

DTIC Science & Technology

2017-08-31

Semi- quantitative MALDI-TOF for antimicrobial susceptibility testing in Staphylococcus 1 aureus 2 3 4 Tucker Maxson,a Cheryl L. Taylor-Howell,a...Timothy D. Minoguea# 5 6 Diagnostic Systems Division, United States Army Medical Research Institute of Infectious 7 Disease, Fort Detrick, MD...USAa 8 9 Running Title: Quantitative MALDI for AST in S. aureus 10 #Address correspondence to Timothy D. Minogue, timothy.d.minogue.civ@mail.mil

Transmission Dynamics of Methicillin-Resistant Staphylococcus aureus in Pigs

PubMed Central

Crombé, Florence; Argudín, M. Angeles; Vanderhaeghen, Wannes; Hermans, Katleen; Haesebrouck, Freddy; Butaye, Patrick

2013-01-01

From the mid-2000s on, numerous studies have shown that methicillin-resistant Staphylococcus aureus (MRSA), renowned as human pathogen, has a reservoir in pigs and other livestock. In Europe and North America, clonal complex (CC) 398 appears to be the predominant lineage involved. Especially worrisome is its capacity to contaminate humans in close contact with affected animals. Indeed, the typical multi-resistant phenotype of MRSA CC398 and its observed ability of easily acquiring genetic material suggests that MRSA CC398 strains with an increased virulence potential may emerge, for which few therapeutic options would remain. This questions the need to implement interventions to control the presence and spread of MRSA CC398 among pigs. MRSA CC398 shows a high but not fully understood transmission potential in the pig population and is able to persist within that population. Although direct contact is probably the main route for MRSA transmission between pigs, also environmental contamination, the presence of other livestock, the herd size, and farm management are factors that may be involved in the dissemination of MRSA CC398. The current review aims at summarizing the research that has so far been done on the transmission dynamics and risk factors for introduction and persistence of MRSA CC398 in farms. PMID:23518663

Modeling the kinetics of survival of Staphylococcus aureus in regional yogurt from goat's milk.

PubMed

Bednarko-Młynarczyk, E; Szteyn, J; Białobrzewski, I; Wiszniewska-Łaszczych, A; Liedtke, K

2015-01-01

The aim of this study was to determine the kinetics of the survival of the test strain of Staphylococcus aureus in the product investigated. Yogurt samples were contaminated with S. aure to an initial level of 10(3)-10(4) cfu/g. The samples were then stored at four temperatures: 4, 6, 20, 22°C. During storage, the number of S. aureus forming colonies in a gram of yogurt was determined every two hours. Based on the results of the analysis culture the curves of survival were plotted. Three primary models were selected to describe the kinetics of changes in the count of bacteria: Cole's model, a modified model of Gompertz and the model of Baranyi and Roberts. Analysis of the model fit carried out based on the average values of Pearson's correlation coefficient, between the modeled and measured values, showed that the Cole's model had the worst fit. The modified Gompertz model showed the count of S. aureus as a negative value. These drawbacks were not observed in the model of Baranyi and Roberts. For this reason, this model best reflects the kinetics of changes in the number of staphylococci in yogurt.

Characterization of Methicillin Resistant Staphylococcus aureus isolated from human and animal samples in Egypt.

PubMed

Bendary, M M; Solyman, S M; Azab, M M; Mahmoud, N F; Hanora, A M

2016-02-29

Staphylococcus aureus (S. aureus) has been one of the most problematic pathogens. Methicillin Resistant S. aureus (MRSA) has emerged as a major concern for both human and animal. Antibiotic resistance genes dissemination might be possible between human and animal bacteria. The aim of this study is to show phenotypic and genotypic diversity of human and animal MRSA isolates. Antibiogram typing and biofilm production were used as a primary phenotypic typing tool for the characterization of (40) animal and (38) human MRSA isolates. Genetic typing based on sequencing of 16S rRNA gene and virulence gene profiles were done. Antimicrobial resistance profiles of the animal isolates showed little evidence of widespread of resistance, although this was seen in many human isolates. The biofilm production was detected in higher percentage among animal isolates. Based on the genetic typing and multiple antibiotic resistance (MAR) index, the majority of animal isolates clustered into lineages that were not found in human isolates. Animal and human MRSA isolates showed diversity in antibiotic resistance and virulence gene profiles may be due to host adaptation or chances for contamination between the two hosts were not present in our study.

[Epidemiology of Staphylococcus aureus nosocomial infections in a high-risk neonatal unit].

PubMed

Velazco, Elsa; Nieves, Beatriz; Araque, María; Calderas, Zoila

2002-01-01

Nosocomial infections are a significant cause of morbidity and mortality throughout the world. In developing countries it is difficult to carry out effective surveillance and control programs for this type of infection because of the cost in both human and material resources. These considerations prompted us to perform a prospective study to determine the epidemiologic and microbiologic characteristics of nosocomial infections due to Staphylococcus aureus in the High-risk Neonatal Unit (HRNU) of the Instituto Autónomo Hospital Universitario de Los Andes (IAHULA), during the period of November 1997 to October 1998. Among a total of 120 microorganisms, 24 (20%) strains of Staphylococcus aureus were isolated; 47% were recovered from blood and 33% from conjunctive samples. Among the cases of conjunctivitis, S. aureus was the only pathogen isolated in 42%. Twenty of the 24 Staphylococcus aureus strains (83%) were methicillin-resistant (MRSA). According to their resistance profiles, we established 12 groups of strains from neonates with nosocomial infections and 1 group of strains from the two carriers among the healthcare personnel detected by microbiological screening. The MeRGmR pattern was the most frequent. Plasmid analysis disclosed two profiles, each having a plasmid molecular weight over 23.130 bp. The MRSA strains isolated from the neonates and those isolated from the carriers showed the same plasmid profile. This suggests that the healthcare personnel may have acted as reservoirs of the MRSA strains found in neonates with nosocomial infection.

Staphylococcus aureus with Panton-Valentine toxin skin infection in a medical laboratory technician.

PubMed

Pougnet, Richard; Pougnet, Laurence

2016-12-01

This report exposes the case of a Staphylococcus aureus infection occurring in a microbiology laboratory technician. He was a 52 year-old man without medical history. He presented an abscess on the anterior aspect of the left forearm. Analysis showed that it was a Staphylococcus aureus secreting the Panton-Valentine toxin. The study of the workplace found the frequency of exposure. The study of workstation showed the link between the technician position and the infection. Indeed, this man touched an area where the biocleaning was hard to do. This is the first case of infection with PVL described for a laboratory technician.

Complete genome sequences of two Staphylococcus aureus ST5 isolates from California, USA

USDA-ARS?s Scientific Manuscript database

Staphylococcus aureus is a bacteria that can cause disease in humans and animals. S. aureus bacteria can transfer or exchange segments of genetic material with other bacteria. These segments are known as mobile genetic elements and in some instances they can encode for factors that increase the abil...

Draft genome sequences of 14 Staphylococcus aureus ST5 isolates from California, USA

USDA-ARS?s Scientific Manuscript database

Staphylococcus aureus is a bacteria that can cause disease in humans and animals. S. aureus bacteria can transfer or exchange segments of genetic material with other bacteria. These segments are known as mobile genetic elements and in some instances they can encode for factors that increase the abil...

Staphylococcus aureus food poisoning among Bulawayo City Council employees, Zimbabwe, 2014.

PubMed

Gumbo, Amen; Bangure, Donewell; Gombe, Notion T; Mungati, More; Tshimanga, Mufuta; Hwalima, Zanele; Dube, Ignatious

2015-09-28

Bulawayo City Council held an Integrated Result Based Management workshop among 86 employees from August 18-22, 2014 at Ikhwezi Training Centre in Bulawayo City. On August 21, 2014, a report of diarrhoea among Council employees attending the workshop was received. We investigated the outbreak to determine the risk factors associated with diarrhoea at Ikhwezi Training Centre, Bulawayo City. A retrospective cohort study was conducted where 74 Council employees were interviewed on food consumed and presenting signs and symptoms. Stool specimens and hand swabs were collected for culture. Water samples were collected for bacteriological analysis. Food samples were not available. Data were analysed using Epi Info™ to generate frequencies, means, proportions, risk ratios, and attributable risk. Of the 74 employees interviewed 34 (45.9%) were males and 40 (54%) were females. The response rate was 94%. The common signs and symptoms included abdominal cramps (88.7%), and watery diarrhoea (86.8%). The overall attack rate was 71.6%. Eating stewed chicken (RR = 2.52, 95% CI 1.30-4.89) served at hour 13:00 during lunch on August 20, 2014 at Ikhwezi Training Centre was the only significant risk factor associated with food poisoning. Drinking purified bottled water [RR = 0.67, 95% CI (0.57-0.79)] was found to be protective. Staphylococcus aureus was isolated from the hands and nails of food handlers. The outbreak was due to food poisoning and was most likely caused by the Staphylococcus aureus formed toxins. Stewed chicken served during lunch on August 20, 2014 was the possible source of infection. Contamination might have occurred during food handling and preparation. Training of food handlers in basic food hygiene and safety is recommended.

Scarlet fever caused by community-associated methicillin-resistant Staphylococcus aureus.

PubMed

Lu, Ying-Chun; Chen, Shyi-Jou; Lo, Wen-Tsung

2011-07-01

We describe a previously healthy 2.5-year-old boy with staphylococcal scarlet fever associated with acute suppurative otitis media due to community-associated methicillin-resistant Staphylococcus aureus. The patient was successfully treated by spontaneous drainage in combination with trimethoprim-sulfamethoxazole therapy.

Staphopains Modulate Staphylococcus aureus Biofilm Integrity

PubMed Central

Mootz, Joe M.; Malone, Cheryl L.; Shaw, Lindsey N.

2013-01-01

Staphylococcus aureus is a known cause of chronic biofilm infections that can reside on medical implants or host tissue. Recent studies have demonstrated an important role for proteinaceous material in the biofilm structure. The S. aureus genome encodes many secreted proteases, and there is growing evidence that these enzymes have self-cleavage properties that alter biofilm integrity. However, the specific contribution of each protease and mechanism of biofilm modulation is not clear. To address this issue, we utilized a sigma factor B (ΔsigB) mutant where protease activity results in a biofilm-negative phenotype, thereby creating a condition where the protease(s) responsible for the phenotype could be identified. Using a plasma-coated microtiter assay, biofilm formation was restored to the ΔsigB mutant through the addition of the cysteine protease inhibitor E-64 or by using Staphostatin inhibitors that specifically target the extracellular cysteine proteases SspB and ScpA (called Staphopains). Through construction of gene deletion mutants, we determined that an sspB scpA double mutant restored ΔsigB biofilm formation, and this recovery could be replicated in plasma-coated flow cell biofilms. Staphopain levels were also found to be decreased under biofilm-forming conditions, possibly allowing biofilm establishment. The treatment of S. aureus biofilms with purified SspB or ScpA enzyme inhibited their formation, and ScpA was also able to disperse an established biofilm. The antibiofilm properties of ScpA were conserved across S. aureus strain lineages. These findings suggest an underappreciated role of the SspB and ScpA cysteine proteases in modulating S. aureus biofilm architecture. PMID:23798534

An Interdisciplinary Experiment: Azo-Dye Metabolism by "Staphylococcus Aureus"

ERIC Educational Resources Information Center

Brocklesby, Kayleigh; Smith, Robert; Sharp, Duncan

2012-01-01

An interdisciplinary and engaging practical is detailed which offers great versatility in the study of a qualitative and quantitative metabolism of azo-dyes by "Staphylococcus aureus". This practical has broad scope for adaptation in the number and depth of variables to allow a focused practical experiment or small research project. Azo-dyes are…

Community-Associated Methicillin-Resistant Staphylococcus aureus Case Studies

PubMed Central

Sowash, Madeleine G.; Uhlemann, Anne-Catrin

2014-01-01

Over the past decade, the emergence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has changed the landscape of S. aureus infections around the globe. Initially recognized for its ability to cause disease in young and healthy individuals without healthcare exposures as well as for its distinct genotype and phenotype, this original description no longer fully encompasses the diversity of CA-MRSA as it continues to expand its niche. Using four case studies, we highlight a wide range of the clinical presentations and challenges of CA-MRSA. Based on these cases we further explore the globally polygenetic background of CA-MRSA with a special emphasis on generally less characterized populations. PMID:24085688

Mild Staphylococcus aureus Skin Infection Improves the Course of Subsequent Endogenous S. aureus Bacteremia in Mice

PubMed Central

van den Berg, Sanne; de Vogel, Corné P.; van Belkum, Alex; Bakker-Woudenberg, Irma A. J. M.

2015-01-01

Staphylococcus aureus carriers with S. aureus bacteremia may have a reduced mortality risk compared to non-carriers. A role for the immune system is suggested. Here, we study in mice the effect of mild S. aureus skin infection prior to endogenous or exogenous S. aureus bacteremia, and evaluate protection in relation to anti-staphylococcal antibody levels. Skin infections once or twice by a clinical S. aureus isolate (isolate P) or S. aureus strain 8325-4 were induced in mice free of S. aureus and anti-staphylococcal antibodies. Five weeks later, immunoglobulin G (IgG) levels in blood against 25 S. aureus antigens were determined, and LD50 or LD100 bacteremia caused by S. aureus isolate P was induced. S. aureus skin infections led to elevated levels of anti-staphylococcal IgG in blood. One skin infection improved the course of subsequent severe endogenous bacteremia only. A second skin infection further improved animal survival rate, which was associated with increased pre-bacteremia IgG levels against Efb, IsaA, LukD, LukE, Nuc, PrsA and WTA. In conclusion, S. aureus isolate P skin infection in mice reduces the severity of subsequent endogenous S. aureus bacteremia only. Although cellular immune effects cannot be rules out, anti-staphylococcal IgG against specified antigens may contribute to this effect. PMID:26060995

Metabolic sensor governing bacterial virulence in Staphylococcus aureus.

PubMed

Ding, Yue; Liu, Xing; Chen, Feifei; Di, Hongxia; Xu, Bin; Zhou, Lu; Deng, Xin; Wu, Min; Yang, Cai-Guang; Lan, Lefu

2014-11-18

An effective metabolism is essential to all living organisms, including the important human pathogen Staphylococcus aureus. To establish successful infection, S. aureus must scavenge nutrients and coordinate its metabolism for proliferation. Meanwhile, it also must produce an array of virulence factors to interfere with host defenses. However, the ways in which S. aureus ties its metabolic state to its virulence regulation remain largely unknown. Here we show that citrate, the first intermediate of the tricarboxylic acid (TCA) cycle, binds to and activates the catabolite control protein E (CcpE) of S. aureus. Using structural and site-directed mutagenesis studies, we demonstrate that two arginine residues (Arg145 and Arg256) within the putative inducer-binding cavity of CcpE are important for its allosteric activation by citrate. Microarray analysis reveals that CcpE tunes the expression of 126 genes that comprise about 4.7% of the S. aureus genome. Intriguingly, although CcpE is a major positive regulator of the TCA-cycle activity, its regulon consists predominantly of genes involved in the pathogenesis of S. aureus. Moreover, inactivation of CcpE results in increased staphyloxanthin production, improved ability to acquire iron, increased resistance to whole-blood-mediated killing, and enhanced bacterial virulence in a mouse model of systemic infection. This study reveals CcpE as an important metabolic sensor that allows S. aureus to sense and adjust its metabolic state and subsequently to coordinate the expression of virulence factors and bacterial virulence.

Toxic shock syndrome due to community-acquired methicillin-resistant Staphylococcus aureus infection: Two case reports and a literature review in Japan.

PubMed

Sada, Ryuichi; Fukuda, Saori; Ishimaru, Hiroyasu

2017-01-01

Community-acquired methicillin-resistant Staphylococcus aureus has been spreading worldwide, including in Japan. However, few cases of toxic shock syndrome caused by Community-acquired methicillin-resistant Staphylococcus aureus have been reported in Japan. We report 2 cases, in middle-aged women, of toxic shock syndrome due to Community-acquired methicillin-resistant Staphylococcus aureus via a vaginal portal of entry. The first patient had used a tampon and the second patient had vaginitis due to a cleft narrowing associated with vulvar lichen sclerosus. Both patients were admitted to our hospital with septic shock and severe acute kidney injury and subsequently recovered with appropriate antibiotic treatment. In our review of the literature, 8 cases of toxic shock syndrome caused by Community-acquired methicillin-resistant Staphylococcus aureus were reported in Japan. In these 8 cases, the main portals of entry were the skin and respiratory tract; however, the portal of entry of Community-acquired methicillin-resistant Staphylococcus aureus from a vaginal lesion has not been reported in Japan previously.

Detoxification of toxins by bacillithiol in Staphylococcus aureus

PubMed Central

Newton, Gerald L.; Fahey, Robert C.

2012-01-01

Bacillithiol (BSH), an α-anomeric glycoside of l-cysteinyl-d-glucosaminyl-l-malate, is a major low-molecular-mass thiol found in bacteria such as Bacillus sp., Staphylococcus aureus and Deinococcus radiodurans. Like other low-molecular-mass thiols such as glutathione and mycothiol, BSH is likely to be involved in protection against environmental toxins including thiol-reactive antibiotics. We report here a BSH-dependent detoxification mechanism in S. aureus. When S. aureus Newman strain was treated with monobromobimane and monochlorobimane, the cellular BSH was converted to the fluorescent S-conjugate BS-bimane. A bacillithiol conjugate amidase activity acted upon the BS-bimane to produce Cys-bimane, which was then acetylated by an N-acetyltransferase to generate N-acetyl-Cys-bimane, a mercapturic acid. An S. aureus mutant lacking BSH did not produce mercapturic acid when treated with monobromobimane and monochlorobimane, confirming the involvement of bacillithiol. Furthermore, treatment of S. aureus Newman with rifamycin, the parent compound of the first-line anti-tuberculosis drug, rifampicin, indicated that this thiol-reactive antibiotic is also detoxified in a BSH-dependent manner, since mercapturic acids of rifamycin were observed in the culture medium. These data indicate that toxins and thiol-reactive antibiotics are detoxified to less potent mercapturic acids in a BSH-dependent manner and then exported out of the cell in S. aureus. PMID:22262099

Bovine origin Staphylococcus aureus: A new zoonotic agent?

PubMed

Rao, Relangi Tulasi; Jayakumar, Kannan; Kumar, Pavitra

2017-10-01

The study aimed to assess the nature of animal origin Staphylococcus aureus strains. The study has zoonotic importance and aimed to compare virulence between two different hosts, i.e., bovine and ovine origin. Conventional polymerase chain reaction-based methods used for the characterization of S. aureus strains and chick embryo model employed for the assessment of virulence capacity of strains. All statistical tests carried on R program, version 3.0.4. After initial screening and molecular characterization of the prevalence of S. aureus found to be 42.62% in bovine origin samples and 28.35% among ovine origin samples. Meanwhile, the methicillin-resistant S. aureus prevalence is found to be meager in both the hosts. Among the samples, only 6.8% isolates tested positive for methicillin resistance. The biofilm formation quantified and the variation compared among the host. A Welch two-sample t -test found to be statistically significant, t=2.3179, df=28.103, and p=0.02795. Chicken embryo model found effective to test the pathogenicity of the strains. The study helped to conclude healthy bovines can act as S. aureus reservoirs. Bovine origin S. aureus strains are more virulent than ovine origin strains. Bovine origin strains have high probability to become zoonotic pathogen. Further, gene knock out studies may be conducted to conclude zoonocity of the bovine origin strains.

Bovine origin Staphylococcus aureus: A new zoonotic agent?

PubMed Central

Rao, Relangi Tulasi; Jayakumar, Kannan; Kumar, Pavitra

2017-01-01

Aim: The study aimed to assess the nature of animal origin Staphylococcus aureus strains. The study has zoonotic importance and aimed to compare virulence between two different hosts, i.e., bovine and ovine origin. Materials and Methods: Conventional polymerase chain reaction-based methods used for the characterization of S. aureus strains and chick embryo model employed for the assessment of virulence capacity of strains. All statistical tests carried on R program, version 3.0.4. Results: After initial screening and molecular characterization of the prevalence of S. aureus found to be 42.62% in bovine origin samples and 28.35% among ovine origin samples. Meanwhile, the methicillin-resistant S. aureus prevalence is found to be meager in both the hosts. Among the samples, only 6.8% isolates tested positive for methicillin resistance. The biofilm formation quantified and the variation compared among the host. A Welch two-sample t-test found to be statistically significant, t=2.3179, df=28.103, and p=0.02795. Chicken embryo model found effective to test the pathogenicity of the strains. Conclusion: The study helped to conclude healthy bovines can act as S. aureus reservoirs. Bovine origin S. aureus strains are more virulent than ovine origin strains. Bovine origin strains have high probability to become zoonotic pathogen. Further, gene knock out studies may be conducted to conclude zoonocity of the bovine origin strains. PMID:29184376

A high incidence of Staphylococcus aureus colonization in the external eyes of patients with atopic dermatitis.

PubMed

Nakata, K; Inoue, Y; Harada, J; Maeda, N; Watanabe, H; Tano, Y; Shimomura, Y; Harino, S; Sawa, M

2000-12-01

To determine the frequency distribution of bacteria on the external surface of eyes of patients with atopic dermatitis (AD) and to investigate the relationship between the frequency of bacterial colonization and the grade of atopy or ocular diseases associated with AD. Comparative cross-sectional study. Thirty-six AD patients (mean age, 24.5 years) and 16 nonatopic, age-matched control participants (mean age, 25.5 years). The eyelid margins and conjunctival sacs were scraped with sterile swabs. These samples were inoculated into aerobic and anaerobic culture media. The frequency distribution of bacteria isolated from the eyelid margins and conjunctival sacs. Bacteria isolated from AD patients were: Staphylococcus aureus in 21 of 36 patients (including methicillin-resistant Staphylococcus aureus in two patients); Staphylococcus epidermidis in two patients (including methicillin-resistant Staphylococcus epidermidis in one patient); other coagulase-negative Staphylococcus in six patients;alpha-streptococcus in three patients; Corynebacterium species in three patients; Neisseria species in two patients; and Propionibacterium acnes in one patient. From the nonatopic control participants, we isolated S. aureus in one patient, S. epidermidis in two patients and alpha-streptococcus in one patient. S. aureus was isolated from 67% of the AD patients, and any type of bacteria was isolated from 86% of the patients. These rates were significantly higher than those of nonatopic control participants (6% S. aureus and 25% any bacteria). There was no significant relationship between the frequency distribution of bacteria and the grade of atopy or associated ocular diseases. High rates of bacterial colonization, especially S. aureus, were found in the conjunctival sacs and eyelid margins of AD patients. In case management of AD patients, this unique distribution of bacteria must be carefully considered.

Duplex Identification of Staphylococcus aureus by Aptamer and Gold Nanoparticles.

PubMed

Chang, Tianjun; Wang, Libo; Zhao, Kexu; Ge, Yu; He, Meng; Li, Gang

2016-06-01

Staphylococcus aureus is the top common pathogen causing infections and food poisoning. Identification of S. aureus is crucial for the disease diagnosis and regulation of food hygiene. Herein, we report an aptamer-AuNPs based method for duplex identification of S. aureus. Using AuNPs as an indicator, SA23, an aptamer against S. aureus, can well identify its target from Escherichia coli, Listeria monocytogenes and Pseudomonas aeruginosa. Furthermore, we find citrate-coated AuNPs can strongly bind to S. aureus, but not bind to Salmonella enterica and Proteus mirabilis, which leads to different color changes in salt solution. This colorimetric response is capable of distinguishing S. aureus from S. enteritidis and P. mirabilis. Thus, using the aptasensor and AuNPs together, S. aureus can be accurately identified from the common pathogens. This duplex identification system is a promising platform for simple visual identification of S. aureus. Additionally, in the aptasensing process, bacteria are incubated with aptamers and then be removed before the aptamers adding to AuNPs, which may avoid the interactions between bacteria and AuNPs. This strategy can be potentially applied in principle to detect other cells by AuNPs-based aptasensors.

The antimicrobial effect of Octenidine-dihydrochloride coated polymer tracheotomy tubes on Staphylococcus aureus and Pseudomonas aeruginosa colonisation

PubMed Central

2009-01-01

Background The surface of polymeric tracheotomy tubes is a favourable environment for biofilm formation and therefore represents a potential risk factor for the development of pneumonia after tracheotomy. The aim of this in-vitro study was to develop octenidine-dihydrochloride (OCT) coated polymer tracheotomy tubes and investigate any effects on Staphylococcus (S.) aureus and Pseudomonas (P.) aeruginosa colonization. Additionally the resistance of the OCT coating was tested using reprocessing procedures like brushing, rinsing and disinfection with glutaraldehyde Results Contamination with S. aureus: Before any reprocessing, OCT coated tracheotomy tubes were colonized with 103 cfu/ml and uncoated tracheotomy tubes with 105 cfu/ml (P = 0.045). After reprocessing, no differences in bacterial concentration between modified and conventional tubes were observed. Contamination with P. aeruginosa: Before reprocessing, OCT coated tubes were colonized with 106 cfu/ml and uncoated tubes with 107 cfu/ml (P = 0.006). After reprocessing, no significant differences were observed. Conclusion OCT coating initially inhibits S. aureus and P. aeruginosa colonisation on tracheotomy tubes. This effect, however, vanishes quickly after reprocessing of the tubes due to poor adhesive properties of the antimicrobial compound. Despite the known antimicrobial effect of OCT, its use for antimicrobial coating of tracheotomy tubes is limited unless methods are developed to allow sustained attachment to the tube. PMID:19630994

The antimicrobial effect of Octenidine-dihydrochloride coated polymer tracheotomy tubes on Staphylococcus aureus and Pseudomonas aeruginosa colonisation.

PubMed

Zumtobel, Michaela; Assadian, Ojan; Leonhard, Matthias; Stadler, Maria; Schneider, Berit

2009-07-25

The surface of polymeric tracheotomy tubes is a favourable environment for biofilm formation and therefore represents a potential risk factor for the development of pneumonia after tracheotomy. The aim of this in-vitro study was to develop octenidine-dihydrochloride (OCT) coated polymer tracheotomy tubes and investigate any effects on Staphylococcus (S.) aureus and Pseudomonas (P.) aeruginosa colonization. Additionally the resistance of the OCT coating was tested using reprocessing procedures like brushing, rinsing and disinfection with glutaraldehyde Contamination with S. aureus: Before any reprocessing, OCT coated tracheotomy tubes were colonized with 103 cfu/ml and uncoated tracheotomy tubes with 105 cfu/ml (P = 0.045). After reprocessing, no differences in bacterial concentration between modified and conventional tubes were observed.Contamination with P. aeruginosa: Before reprocessing, OCT coated tubes were colonized with 106 cfu/ml and uncoated tubes with 107 cfu/ml (P = 0.006). After reprocessing, no significant differences were observed. OCT coating initially inhibits S. aureus and P. aeruginosa colonisation on tracheotomy tubes. This effect, however, vanishes quickly after reprocessing of the tubes due to poor adhesive properties of the antimicrobial compound. Despite the known antimicrobial effect of OCT, its use for antimicrobial coating of tracheotomy tubes is limited unless methods are developed to allow sustained attachment to the tube.

Staphylococcus aureus Central Nervous System Infections in Children.

PubMed

Vallejo, Jesus G; Cain, Alexandra N; Mason, Edward O; Kaplan, Sheldon L; Hultén, Kristina G

2017-10-01

Central nervous system (CNS) infections caused by Staphylococcus aureus are uncommon in pediatric patients. We review the epidemiology, clinical features and treatment in 68 patients with a S. aureus CNS infection evaluated at Texas Children's Hospital. Cases of CNS infection in children with positive cerebrospinal fluid cultures or spinal epidural abscess (SEA) for S. aureus at Texas Children's Hospital from 2001 to 2013 were reviewed. Seventy cases of S. aureus CNS infection occurred in 68 patients. Forty-nine cases (70%) were secondary to a CNS device, 5 (7.1%) were postoperative meningitis, 9 (12.8%) were hematogenous meningitis and 7 (10%) were SEAs. Forty-seven (67.2%) were caused by methicillin-sensitive S. aureus (MSSA) and 23 (32.8%) by methicillin-resistant S. aureus (MRSA). Community-acquired infections were more often caused by MRSA that was clone USA300/pvl. Most patients were treated with nafcillin (MSSA) or vancomycin (MRSA) with or without rifampin. Among patients with MRSA infection, 50% had a serum vancomycin trough obtained with the median level being 10.6 μg/mL (range: 5.4-15.7 μg/mL). Only 1 death was associated with S. aureus infection. The epidemiology of invasive of S. aureus infections continues to evolve with MSSA accounting for most of the infections in this series. The majority of cases were associated with neurosurgical procedures; however, hematogenous S. aureus meningitis and SEA occurred as community-acquired infections in patients without predisposing factors. Patients with MRSA CNS infections had a favorable response to vancomycin, but the beneficial effect of combination therapy or targeting vancomycin trough concentrations of 15-20 μg/mL remains unclear.

eap Gene as novel target for specific identification of Staphylococcus aureus.

PubMed

Hussain, Muzaffar; von Eiff, Christof; Sinha, Bhanu; Joost, Insa; Herrmann, Mathias; Peters, Georg; Becker, Karsten

2008-02-01

The cell surface-associated extracellular adherence protein (Eap) mediates adherence of Staphylococcus aureus to host extracellular matrix components and inhibits inflammation, wound healing, and angiogenesis. A well-characterized collection of S. aureus and non-S. aureus staphylococcal isolates (n = 813) was tested for the presence of the Eap-encoding gene (eap) by PCR to investigate the use of the eap gene as a specific diagnostic tool for identification of S. aureus. Whereas all 597 S. aureus isolates were eap positive, this gene was not detectable in 216 non-S. aureus staphylococcal isolates comprising 47 different species and subspecies of coagulase-negative staphylococci and non-S. aureus coagulase-positive or coagulase-variable staphylococci. Furthermore, non-S. aureus isolates did not express Eap homologs, as verified on the transcriptional and protein levels. Based on these data, the sensitivity and specificity of the newly developed PCR targeting the eap gene were both 100%. Thus, the unique occurrence of Eap in S. aureus offers a promising tool particularly suitable for molecular diagnostics of this pathogen.

Carriage of methicillin-resistant Staphylococcus aureus by healthy companion animals

USDA-ARS?s Scientific Manuscript database

Methicillin-resistant Staphylococcus aureus (MRSA) is a significant human pathogen and has also been associated with wounded or ill companion animals. Healthy animals may also harbor MRSA without presenting any symptoms, but little is known about the prevalence of MRSA among these animals. Therefo...

Protective effects of tenuigenin on Staphylococcus aureus-induced pneumonia in mice.

PubMed

Yu, Bin; Qiao, Jiutao; Shen, Yongbin; Li, Lianyong

2017-09-01

Pneumonia is the leading cause of death in infants and young children. Staphylococcus aureus (S.aureus) is one of the most important bacteria that leads to pneumonia. Tenuigenin (TGN), a major active component isolated from the root of the Chinese herb Polygala tenuifolia, has been known to have anti-inflammatory effect. In this study, we aimed to investigate the protective effects of TGN on S.aureus-induced pneumonia in mice. The results showed that TGN significantly attenuated S.aureus-induced lung histopathological changes. TGN also inhibited lung wet/dry (W/D) ratio, and inflammatory cytokines TNF-α and IL-1β production. Furthermore, S.aureus-induced NF-κB activation was significantly inhibited by the treatment of TGN. In conclusion, the results of this study showed that TGN protected against S.aureus-induced pneumonia by inhibiting NF-κB activation. TGN might be a potential agent in the treatment of pneumonia induced by S.aureus. Copyright © 2017 Elsevier Ltd. All rights reserved.

Methicillin-resistant Staphylococcus aureus in central Iowa wildlife.

PubMed

Wardyn, Shylo E; Kauffman, Lin K; Smith, Tara C

2012-10-01

Livestock and pets have been identified as carriers of Staphylococcus aureus; however, the role of wild animals as a reservoir of S. aureus strains has not yet been examined. We conducted a pilot study to determine the prevalence of methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) in 37 species of wild animals rehabilitated at a university clinic. Nasal, wing, wound, and cloacal swabs were collected. Of 114 animals, seven (6.1%) were MSSA-positive and three (2.6%) were MRSA-positive. The MRSA isolates were obtained from two eastern cottontail rabbits (Sylvilagus floridanus) and a Lesser Yellowlegs (Tringa flavipes), a migratory shorebird. Antibiotic resistance testing of the MRSA isolates revealed that two were additionally resistant to tetracycline and erythromycin, and the third isolate was also resistant to erythromycin, clindamycin, and levofloxacin. All three isolates were positive for the Panton-Valentine leukocidin (PVL) gene. Sequence typing of the staphylococcal protein A (spa) region revealed one MRSA isolate to be t002, whereas the other two MRSA isolates were found to be t008. Our results suggest that S. aureus, including MRSA, is being carried by wild animals, although at a low prevalence with the limited number of animals tested. Additional studies are needed to determine how this may impact human health.

Phenazine antibiotic inspired discovery of potent bromophenazine antibacterial agents against Staphylococcus aureus and Staphylococcus epidermidis.

PubMed

Borrero, Nicholas V; Bai, Fang; Perez, Cristian; Duong, Benjamin Q; Rocca, James R; Jin, Shouguang; Huigens, Robert W

2014-02-14

Nearly all clinically used antibiotics have been (1) discovered from microorganisms (2) using phenotype screens to identify inhibitors of bacterial growth. The effectiveness of these antibiotics is attributed to their endogenous roles as bacterial warfare agents against competing microorganisms. Unfortunately, every class of clinically used antibiotic has been met with drug resistant bacteria. In fact, the emergence of resistant bacterial infections coupled to the dismal pipeline of new antibacterial agents has resulted in a global health care crisis. There is an urgent need for innovative antibacterial strategies and treatment options to effectively combat drug resistant bacterial pathogens. Here, we describe the implementation of a Pseudomonas competition strategy, using redox-active phenazines, to identify novel antibacterial leads against Staphylococcus aureus and Staphylococcus epidermidis. In this report, we describe the chemical synthesis and evaluation of a diverse 27-membered phenazine library. Using this microbial warfare inspired approach, we have identified several bromophenazines with potent antibacterial activities against S. aureus and S. epidermidis. The most potent bromophenazine analogue from this focused library demonstrated a minimum inhibitory concentration (MIC) of 0.78-1.56 μM, or 0.31-0.62 μg mL(-1), against S. aureus and S. epidermidis and proved to be 32- to 64-fold more potent than the phenazine antibiotic pyocyanin in head-to-head MIC experiments. In addition to the discovery of potent antibacterial agents against S. aureus and S. epidermidis, we also report a detailed structure-activity relationship for this class of bromophenazine small molecules.

A natural human monoclonal antibody targeting Staphylococcus Protein A protects against Staphylococcus aureus bacteremia

PubMed Central

Varshney, Avanish K.; Sunley, Kevin M.; Bowling, Rodney A.; Kwan, Tzu-Yu; Mays, Heather R.; Rambhadran, Anu; Zhang, Yanfeng; Martin, Rebecca L.; Cavalier, Michael C.; Simard, John

2018-01-01

Staphylococcus aureus can cause devastating and life-threatening infections. With the increase in multidrug resistant strains, novel therapies are needed. Limited success with active and passive immunization strategies have been attributed to S. aureus immune evasion. Here, we report on a monoclonal antibody, 514G3, that circumvents a key S. aureus evasion mechanism by targeting the cell wall moiety Protein A (SpA). SpA tightly binds most subclasses of immunoglobulins via their Fc region, neutralizing effector function. The organism can thus shield itself with a protective coat of serum antibodies and render humoral immunity ineffective. The present antibody reactivity was derived from an individual with natural anti-SpA antibody titers. The monoclonal antibody is of an IgG3 subclass, which differs critically from other immunoglobulin subclasses since its Fc is not bound by SpA. Moreover, it targets a unique epitope on SpA that allows it to bind in the presence of serum antibodies. Consequently, the antibody opsonizes S. aureus and maintains effector function to enable natural immune mediated clearance. The data presented here provide evidence that 514G3 antibody is able to successfully rescue mice from S. aureus mediated bacteremia. PMID:29364906

Livestock-associated Methicillin-Resistant Staphylococcus aureus in Humans, Europe

PubMed Central

Monnet, Dominique L.; Voss, Andreas; Krziwanek, Karina; Allerberger, Franz; Struelens, Marc; Zemlickova, Helena; Skov, Robert L.; Vuopio-Varkila, Jaana; Cuny, Christiane; Friedrich, Alexander W.; Spiliopoulou, Iris; Pászti, Judit; Hardardottir, Hjordis; Rossney, Angela; Pan, Angelo; Pantosti, Annalisa; Borg, Michael; Grundmann, Hajo; Mueller-Premru, Manica; Olsson-Liljequist, Barbro; Widmer, Andreas; Harbarth, Stephan; Schweiger, Alexander; Unal, Serhat; Kluytmans, Jan A.J.W.

2011-01-01

To estimate the proportion of methicillin-resistant Staphylococcus aureus (MRSA) isolates from humans that were sequence type (ST) 398, we surveyed 24 laboratories in 17 countries in Europe in 2007. Livestock-associated MRSA ST398 accounted for only a small proportion of MRSA isolates from humans; most were from the Netherlands, Belgium, Denmark, and Austria. PMID:21392444

Metabolic activity, urease production, antibiotic resistance and virulence in dual species biofilms of Staphylococcus epidermidis and Staphylococcus aureus

PubMed Central

Vandecandelaere, Ilse; Van Nieuwerburgh, Filip; Deforce, Dieter

2017-01-01

In this paper, the metabolic activity in single and dual species biofilms of Staphylococcus epidermidis and Staphylococcus aureus isolates was investigated. Our results demonstrated that there was less metabolic activity in dual species biofilms compared to S. aureus biofilms. However, this was not observed if S. aureus and S. epidermidis were obtained from the same sample. The largest effect on metabolic activity was observed in biofilms of S. aureus Mu50 and S. epidermidis ET-024. A transcriptomic analysis of these dual species biofilms showed that urease genes and genes encoding proteins involved in metabolism were downregulated in comparison to monospecies biofilms. These results were subsequently confirmed by phenotypic assays. As metabolic activity is related to acid production, the pH in dual species biofilms was slightly higher compared to S. aureus Mu50 biofilms. Our results showed that S. epidermidis ET-024 in dual species biofilms inhibits metabolic activity of S. aureus Mu50, leading to less acid production. As a consequence, less urease activity is required to compensate for low pH. Importantly, this effect was biofilm-specific. Also S. aureus Mu50 genes encoding virulence-associated proteins (Spa, SplF and Dps) were upregulated in dual species biofilms compared to monospecies biofilms and using Caenorhabditis elegans infection assays, we demonstrated that more nematodes survived when co-infected with S. epidermidis ET-024 and S. aureus mutants lacking functional spa, splF or dps genes, compared to nematodes infected with S. epidermidis ET-024 and wild- type S. aureus. Finally, S. epidermidis ET-024 genes encoding resistance to oxacillin, erythromycin and tobramycin were upregulated in dual species biofilms and increased resistance was subsequently confirmed. Our data indicate that both species in dual species biofilms of S. epidermidis and S. aureus influence each other’s behavior, but additional studies are required necessary to elucidate the exact

Methicillin-resistant Staphylococcus aureus survival on hospital fomites.

PubMed

Huang, Robert; Mehta, Sanjay; Weed, Diane; Price, Connie Savor

2006-11-01

We examined the duration of survival of 2 strains of methicillin-resistant Staphylococcus aureus (MRSA) on 3 types of hospital fomites. MRSA survived for 11 days on a plastic patient chart, more than 12 days on a laminated tabletop, and 9 days on a cloth curtain. Irregular surfaces may help harbor organisms in the environment. In addition to contact precautions, MRSA containment during an outbreak should include concurrent environmental decontamination.

Low occurrence of the new species Staphylococcus argenteus in a Staphylococcus aureus collection of human isolates from Belgium.

PubMed

Argudín, M A; Dodémont, M; Vandendriessche, S; Rottiers, S; Tribes, C; Roisin, S; de Mendonça, R; Nonhoff, C; Deplano, A; Denis, O

2016-06-01

Staphylococcus argenteus is a novel Staphylococcus species closely related to Staphylococcus aureus that has been recently described. In this study, we investigated the proportion and the characteristics of S. argenteus recovered from humans in Belgium. S. aureus. human isolates collected in Belgium from 2006 to 2015 (n = 1,903) were retrospectively characterised via the presence of non-pigmented colonies on chocolate agar, spa typing and rpoB sequencing to determine if some of them were in fact S. argenteus. Out of 73 strains non-pigmented on chocolate plates, 3 isolates (0.16 %) showed rpoB sequences, in addition to spa and sequence types (ST2250/t5787, ST2250/t6675, ST3240/t6675), related to S. argenteus. Two of them were methicillin-resistant, harbouring a SCCmec type IV. The three S. argenteus isolates carried genes (sak, scn) of the immune evasion cluster. This first Belgian nationwide analysis showed a low occurrence of S. argenteus. Further studies should be conducted to identify the distribution range and the clinical impact of this new species.

Mannitol-negative methicillin-resistant Staphylococcus aureus from nasal swab specimens in Brazil.

PubMed

dos Santos, Danielle Caldeira Martins; da Costa, Thaina Miranda; Rabello, Renata Fernandes; Alves, Fábio Aguiar; de Mondino, Silvia Susana Bona

2015-06-01

The isolation of mannitol-negative methicillin-resistant Staphylococcus aureus from nasal swabs is reported. Among the 59 isolates, 9 (15%) isolates were mannitol-negative; all of these isolates were categorized as staphylococcal cassette chromosome mec (SCCmec) type IVa. This report emphasizes that mannitol fermentation on mannitol salt agar should not be used as the sole criterion when screening nasal swab specimens for S. aureus.

Assessment of Staphylococcus aureus along milk value chain and its public health importance in Sebeta, central Oromia, Ethiopia.

PubMed

Ayele, Yodit; Gutema, Fanta Desissa; Edao, Bedaso Mamo; Girma, Robel; Tufa, Takele Beyene; Beyene, Tariku Jibat; Tadesse, Fanos; Geloye, Mesula; Beyi, Ashenafi Feyisa

2017-06-27

Staphylococcus aureus is one of the leading causes of gastroenteritis acquired from contaminated foods such as milk and milk products. However, such information is limited in Ethiopia. A cross-sectional study was conducted to assess the contamination of milk with S. aureus and knowledge, attitudes and practices (KAP) of actors along the milk value chain in Sebeta, Central Oromia, Ethiopia. A total of 291 samples collected from dairy farms, milk collection centers (MCCs) and processing plant were examined using standard microbiological techniques. The antimicrobial susceptibility profiles of the isolates were also investigated. The KAP of actors in milk value chain were evaluated through a structured questionnaire. Overall, 23.4% (n = 68) of the samples were positive for S. aureus. The prevalence of S. aureus was 19.6% (95% CI: 14.5-25.6) and 80.0% (95% CI: 14.5-25.6) at farm level and MCCs, respectively. Higher isolation rate was observed in the MCCs (p = 0.000) than the farms. The contamination rates of hands of milkers' and milking buckets with S. aureus were 32% and 11.1%, respectively. S. aureus was not isolated from pasteurized milk samples. The isolates were found to be resistant to cefoxitin (100%), penicillin G (98.5%), and streptomycin (77.9%). Among 23 interviewed farmers, 35% of them consumed raw milk, none of them wash their hands and 82.6% did not wash udder and teat before milking. Six percent of consumers had the habit of raw milk consumption. Eighty seven percent of dairy farmers and 54% of consumers had no awareness about milk borne diseases and staphylococcal food poisoning. The study revealed a high prevalence of S. aureus along the milk value chain, poor milk handling practices, raw milk consumption behavior, lack of awareness about milk borne diseases and occurrence of antimicrobials resistant S. aureus. S. aureus seems to pose a public health risk in Sebeta. Authors recommended the urgent need of public awareness creation about the

Methicillin-resistant Staphylococcus aureus harboring mecC in livestock in Spain.

PubMed

Ariza-Miguel, Jaime; Hernández, Marta; Fernández-Natal, Isabel; Rodríguez-Lázaro, David

2014-11-01

We report for the first time mecC-positive methicillin-resistant Staphylococcus aureus (mecC-MRSA) in livestock in Spain. One isolate (sequence type 130) was found in milk samples among 601 S. aureus isolates obtained from 229 dairy sheep farms. This finding highlights the potential for zoonotic transmission of mecC-positive MRSA and the need for surveillance programs to monitor its presence and clonal evolution. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Scintigraphic imaging of Staphylococcus aureus infection using 99mTc radiolabeled aptamers.

PubMed

Santos, Sara Roberta Dos; de Sousa Lacerda, Camila Maria; Ferreira, Iêda Mendes; de Barros, André Luís Branco; Fernandes, Simone Odília; Cardoso, Valbert Nascimento; de Andrade, Antero Silva Ribeiro

2017-10-01

Staphylococcus aureus is a specie of great medical importance associated with many infections as bacteremia and infective endocarditis as well as osteoarticular, skin and soft tissue, pleuropulmonary, and device related infections. Early identification of infectious foci is crucial for successful treatment. Scintigraphy could contribute to this purpose since specific radiotracers were available. Aptamers due to their high specificity have great potential for radiopharmaceuticals development. In the present study scintigraphic images of S. aureus infectious foci were obtained using specific S. aureus aptamers radiolabeled with 99m Tc. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Collagen-Binding Adhesin Is a Virulence Factor in Staphylococcus aureus Keratitis

PubMed Central

Rhem, Marcus N.; Lech, Elizabeth M.; Patti, Joseph M.; McDevitt, Damien; Höök, Magnus; Jones, Dan B.; Wilhelmus, Kirk R.

2000-01-01

A collagen-binding strain of Staphylococcus aureus produced suppurative inflammation in a rabbit model of soft contact lens-associated bacterial keratitis more often than its collagen-binding-negative isogenic mutant. Reintroduction of the cna gene on a multicopy plasmid into the mutant helped it regain its corneal adherence and infectivity. The topical application of a collagen-binding peptide before bacterial challenge decreased S. aureus adherence to deepithelialized corneas. These data suggest that the collagen-binding adhesin is involved in the pathogenesis of S. aureus infection of the cornea. PMID:10816547

Comparison of community-onset Staphylococcus argenteus and Staphylococcus aureus sepsis in Thailand: a prospective multicentre observational study.

PubMed

Chantratita, N; Wikraiphat, C; Tandhavanant, S; Wongsuvan, G; Ariyaprasert, P; Suntornsut, P; Thaipadungpanit, J; Teerawattanasook, N; Jutrakul, Y; Srisurat, N; Chaimanee, P; Anukunananchai, J; Phiphitaporn, S; Srisamang, P; Chetchotisakd, P; West, T E; Peacock, S J

2016-05-01

Staphylococcus argenteus is a globally distributed cause of human infection, but diagnostic laboratories misidentify this as Staphylococcus aureus. We determined whether there is clinical utility in distinguishing between the two. A prospective cohort study of community-onset invasive staphylococcal sepsis was conducted in adults at four hospitals in northeast Thailand between 2010 and 2013. Of 311 patients analysed, 58 (19%) were infected with S. argenteus and 253 (81%) with S. aureus. Most S. argenteus (54/58) were multilocus sequence type 2250. Infection with S. argenteus was more common in males, but rates of bacteraemia and drainage procedures were similar in the two groups. S. argenteus precipitated significantly less respiratory failure than S. aureus (5.2% versus 20.2%, adjusted OR 0.21, 95% CI 0.06-0.74, p 0.015), with a similar but non-significant trend for shock (6.9% versus 12.3%, adjusted OR 0.46, 95% CI 0.15-1.44, p 0.18). This did not translate into a difference in death at 28 days (6.9% versus 8.7%, adjusted OR 0.80, 95% CI 0.24-2.65, p 0.72). S. argenteus was more susceptible to antimicrobial drugs compared with S. aureus, and contained fewer toxin genes although pvl was detected in 16% (9/58). We conclude that clinical differences exist in association with sepsis due to S. argenteus versus S. aureus. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Staphylococcus aureus synthesizes adenosine to escape host immune responses

PubMed Central

Thammavongsa, Vilasack; Kern, Justin W.; Missiakas, Dominique M.

2009-01-01

Staphylococcus aureus infects hospitalized or healthy individuals and represents the most frequent cause of bacteremia, treatment of which is complicated by the emergence of methicillin-resistant S. aureus. We examined the ability of S. aureus to escape phagocytic clearance in blood and identified adenosine synthase A (AdsA), a cell wall–anchored enzyme that converts adenosine monophosphate to adenosine, as a critical virulence factor. Staphylococcal synthesis of adenosine in blood, escape from phagocytic clearance, and subsequent formation of organ abscesses were all dependent on adsA and could be rescued by an exogenous supply of adenosine. An AdsA homologue was identified in the anthrax pathogen, and adenosine synthesis also enabled escape of Bacillus anthracis from phagocytic clearance. Collectively, these results suggest that staphylococci and other bacterial pathogens exploit the immunomodulatory attributes of adenosine to escape host immune responses. PMID:19808256

Inhibitory Effects of Pterodon emarginatus Bean Oil and Extract on Staphylococcus aureus

PubMed Central

Mendes, V. S.; Sant'Anna, J. B.; Oliveira, S. C. C.; Maldonade, Iriani Rodrigues; Machado, Eleuza Rodrigues

2017-01-01

Background: Pterodon emarginatus is a tree of the Brazilian Savannah. The beans of this tree are used in folk medicine as anti-inflammatory preparations, especially for infections caused by Staphylococcus aureus. These bacteria can cause simple infections or serious illnesses such as pneumonia, meningitis, endocarditis, toxic shock syndrome, septicemia, and others. Objective: This study had the goal of verifying the effect of the essential oil (OE) from P. emarginatus on the inhibition of S. aureus in culture medium, i.e., “ in vitro” tests. Materials and Methods: The vegetable material was cut and crushed with a press. The OE was obtained by extraction using hexane, alcohol, and water. The P. emarginatus extracts obtained were used to evaluate the antimicrobial effect on S. aureus (ATCC 25923) by tests of well diffusion, disc diffusion, and microdilution. The strain used in the assays was maintained in brain heart infusion broth and nutrient agar until testing. Afterward, the bacteria were spread on agar plates with Mueller-Hinton agar medium. In the wells and on the paper discs, the OE suspensions were placed in the following volumes: 10, 15, 20, 25, 30, 40, and 80 μL and subsequently they were incubated at 35°C ± 2°C. After 24 h, the number of colony-forming unit was determined. Results: Pure OE and hydroalcoholic extract inhibited the growth of S. aureus, while aqueous extract had no effect on bacterial growth in all microbial methods used. Conclusion: Thus, the present study showed the potential of sucupira-based extracts against S. aureus growth, opening new perspectives for the evaluation of these bioactive compounds as phytopharmaceutical products. SUMMARY Plant extract act as antimicrobials to prevent and reduce bacterial contaminationBeans of Pterodon emarginatus has antibacterial propertiesExtraction with different solvents might implicate on the rate of bacterial deathThe effect of different microbiological methods (well diffusion, disc

Virtual screening for development of new effective compounds against Staphylococcus aureus.

PubMed

Diniz, Roseane Costa; Soares, Lucas Weba; da Silva, Luis Claudio Nascimento

2018-03-26

Staphylococcus aureus is a notorious pathogenic bacterium causing a wide range of diseases from soft-tissue contamination, to more serious and deep-seated infections. This species is highlighted by its ability to express several kinds of virulence factors and to acquire genes related to drug resistance. Target this number of factors to design any drug is not an easy task. In this review we discuss the importance of computational methods to impulse the development of new drugs against S. aureus. The application of docking methods to screen large library of natural or synthetic compounds and to provide insights into action mechanisms is demonstrated. Particularly, highlighted the studies that validated in silico results with biochemical and microbiological assays. We also comment the computer-aided design of new molecules using some known inhibitors. The confirmation of in silico results with biochemical and microbiological assays allowed the identification of lead molecules that could be used for drug design such as rhodomyrtone, quinuclidine, berberine (and their derivative compounds). The fast development in the computational methods is essential to improve our ability to discovery new drugs, as well as to expand understanding about drug-target interactions. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Response of Staphylococcus aureus isolates from bovine mastitis to exogenous iron sources.

PubMed

Diarra, M S; Petitclerc, D; Lacasse, P

2002-09-01

Staphylococcus aureus can survive in conditions of extremely low iron concentration. The ability of S. aureus to use two exogenous hydroxamate types of siderophores (desferrioxamine and ferrichrome) and four iron-containing proteins found in cattle (hemin, hemoglobin, ferritin, and lactoferrin) were tested on 16 reference and clinical isolates. For all strains tested, ferrichrome and desferrioxamine showed strong growth-promoting activities in a disk diffusion assay and in liquid medium. The heme proteins hemin and hemoglobin were also found to support growth in culture media lacking other iron sources, while lactoferrin failed to do so. On media containing the iron chelator dipyridyl, ferritin induced a growth inhibition effect that was further enhanced in the presence of lactoferrin in seven of the 13 tested strains. Staphylococcus aureus was able to bind hemin and the level of binding activity was not increased after growth in iron-rich or -poor media. Dot-blot competition tests showed that biotin-labeled lactoferrin binds to S. aureus, and this binding can be inhibited by unlabeled lactoferrin. Expression of lactoferrin-binding activity was independent of the level of iron in the medium and the iron saturation status of lactoferrin. For each strain tested, ligand blots showed lactoferrin-binding proteins of molecular weights ranging from 32 to 92 kDa. Possible functions of these lactoferrin-binding proteins could not be related to iron acquisition mechanism in S. aureus.

Epic Immune Battles of History: Neutrophils vs. Staphylococcus aureus.

PubMed

Guerra, Fermin E; Borgogna, Timothy R; Patel, Delisha M; Sward, Eli W; Voyich, Jovanka M

2017-01-01

Neutrophils are the most abundant leukocytes in human blood and the first line of defense after bacteria have breached the epithelial barriers. After migration to a site of infection, neutrophils engage and expose invading microorganisms to antimicrobial peptides and proteins, as well as reactive oxygen species, as part of their bactericidal arsenal. Ideally, neutrophils ingest bacteria to prevent damage to surrounding cells and tissues, kill invading microorganisms with antimicrobial mechanisms, undergo programmed cell death to minimize inflammation, and are cleared away by macrophages. Staphylococcus aureus ( S. aureus ) is a prevalent Gram-positive bacterium that is a common commensal and causes a wide range of diseases from skin infections to endocarditis. Since its discovery, S. aureus has been a formidable neutrophil foe that has challenged the efficacy of this professional assassin. Indeed, proper clearance of S. aureus by neutrophils is essential to positive infection outcome, and S. aureus has developed mechanisms to evade neutrophil killing. Herein, we will review mechanisms used by S. aureus to modulate and evade neutrophil bactericidal mechanisms including priming, activation, chemotaxis, production of reactive oxygen species, and resolution of infection. We will also highlight how S. aureus uses sensory/regulatory systems to tailor production of virulence factors specifically to the triggering signal, e.g., neutrophils and defensins. To conclude, we will provide an overview of therapeutic approaches that may potentially enhance neutrophil antimicrobial functions.

Epic Immune Battles of History: Neutrophils vs. Staphylococcus aureus

PubMed Central

Guerra, Fermin E.; Borgogna, Timothy R.; Patel, Delisha M.; Sward, Eli W.; Voyich, Jovanka M.

2017-01-01

Neutrophils are the most abundant leukocytes in human blood and the first line of defense after bacteria have breached the epithelial barriers. After migration to a site of infection, neutrophils engage and expose invading microorganisms to antimicrobial peptides and proteins, as well as reactive oxygen species, as part of their bactericidal arsenal. Ideally, neutrophils ingest bacteria to prevent damage to surrounding cells and tissues, kill invading microorganisms with antimicrobial mechanisms, undergo programmed cell death to minimize inflammation, and are cleared away by macrophages. Staphylococcus aureus (S. aureus) is a prevalent Gram-positive bacterium that is a common commensal and causes a wide range of diseases from skin infections to endocarditis. Since its discovery, S. aureus has been a formidable neutrophil foe that has challenged the efficacy of this professional assassin. Indeed, proper clearance of S. aureus by neutrophils is essential to positive infection outcome, and S. aureus has developed mechanisms to evade neutrophil killing. Herein, we will review mechanisms used by S. aureus to modulate and evade neutrophil bactericidal mechanisms including priming, activation, chemotaxis, production of reactive oxygen species, and resolution of infection. We will also highlight how S. aureus uses sensory/regulatory systems to tailor production of virulence factors specifically to the triggering signal, e.g., neutrophils and defensins. To conclude, we will provide an overview of therapeutic approaches that may potentially enhance neutrophil antimicrobial functions. PMID:28713774

Healing Potentials of Oral Moringa Oleifera Leaves Extract and Tetracycline on Methicillin Resistant Staphylococcus Aureus Infected Wounds of Wistar rats.

PubMed

Eyarefe, Oghenemega D; Idowu, Aderayo; Afolabi, Jeremiah M

2015-12-20

The effects of oral dose of aqueous extract of Moringa oleifera and tetracycline antibiotics on cutaneous wounds infected with Staphylococcus aureus were studied in eighteen adult wistar rats (159±31.5g) randomized into three groups: Group A, n = 6, Moringa oleifera-(300 mg/kg). Group B, n = 6, tetracycline (9.4 mg/kg) and Group C, n = 6, Sterile water (control). Six millimetres diameter nape wound, created on each rat under 2% xylazine (5 mg/kg) and 5% ketamine (35 mg/kg), was contaminated with Staphylococcus aureus (108 Colony Forming Unit (CFU). Following infection, treatment was commenced with daily oral dose of test preparations and the wounds were evaluated every other day i.e., day 3, 5, 7, 9, 11, 13 and 15 for wetness (wound exudation), wound edge oedema, hyperaemia, granulation tissues and contraction (diameter). Severe wound exudation existed in all the groups between days 0-3 (p = 1.00). A significantly less wound exudation was observed at days 3-5 (p = 0.000) and 5-9 (p = 0.003) (Control< Tetracycline Moringa> Tetracycline). Differences in wound diameter was not significant except at days 5-9 (p = 0.013) (Control> Moringa >Tetracycline). Oral doses of Moringa oleifera extract (300mg/kg) and tetracycline (9.4mg/kg) are not effective as antimicrobial or immune-boosting agents to enhance healing of wounds infected with Staphylococcus aureus and hence not recommended for rapid clearance of Staphylococcus aureus infected wounds.

A Tick Antivirulence Protein Potentiates Antibiotics against Staphylococcus aureus

PubMed Central

Abraham, Nabil M.; Liu, Lei; Jutras, Brandon L.; Murfin, Kristen; Acar, Ali; Yarovinsky, Timur O.; Sutton, Erica; Heisig, Martin; Jacobs-Wagner, Christine

2017-01-01

ABSTRACT New strategies are needed to combat antibiotic resistance, especially against pathogens such as methicillin-resistant Staphylococcus aureus. A tick antifreeze glycoprotein, IAFGP, possesses potent antibiofilm properties against a variety of clinical pathogens, including S. aureus. Synergy between IAFGP, or a peptide (P1) representative of a repeat region of the protein, with different antibiotics was assessed in vitro. Antibiotics that synergized with either IAFPG or P1 were further evaluated in vivo using vertebrate and invertebrate infection models. IAFGP readily enhanced the efficacy of antibiotics against S. aureus. Synergy with daptomycin, an antibiotic used to treat methicillin-resistant S. aureus, was observed in vitro and in vivo using iafgp-transgenic mice and flies. Furthermore, synergy with ciprofloxacin or gentamicin, antibiotics not generally used to treat S. aureus, was also perceived. The combined effect of the antibiotic and IAFGP was associated with improved permeation of the antibiotic into the cell. Our results highlight that synergy of IAFGP with antibiotics traditionally used to treat this pathogen, and enhancement of the potency of antibiotics not commonly used against this microbe, can provide novel alternative therapeutic strategies to combat bacterial infections. PMID:28438938

Neutrophil-generated oxidative stress and protein damage in Staphylococcus aureus

PubMed Central

Beavers, William N.; Skaar, Eric P.

2016-01-01

Staphylococcus aureus is a ubiquitous, versatile and dangerous pathogen. It colonizes over 30% of the human population, and is one of the leading causes of death by an infectious agent. During S. aureus colonization and invasion, leukocytes are recruited to the site of infection. To combat S. aureus, leukocytes generate an arsenal of reactive species including superoxide, hydrogen peroxide, nitric oxide and hypohalous acids that modify and inactivate cellular macromolecules, resulting in growth defects or death. When S. aureus colonization cannot be cleared by the immune system, antibiotic treatment is necessary and can be effective. Yet, this organism quickly gains resistance to each new antibiotic it encounters. Therefore, it is in the interest of human health to acquire a deeper understanding of how S. aureus evades killing by the immune system. Advances in this field will have implications for the design of future S. aureus treatments that complement and assist the host immune response. In that regard, this review focuses on how S. aureus avoids host-generated oxidative stress, and discusses the mechanisms used by S. aureus to survive oxidative damage including antioxidants, direct repair of damaged proteins, sensing oxidant stress and transcriptional changes. This review will elucidate areas for studies to identify and validate future antimicrobial targets. PMID:27354296

Inhibiting platelets aggregation could aggravate the acute infection caused by Staphylococcus aureus.

PubMed

Zhang, Xin; Liu, Yu; Gao, Yaping; Dong, Jie; Mu, Chunhua; Lu, Qiang; Shao, Ningsheng; Yang, Guang

2011-01-01

Several fibrinogen binding proteins (Fibs) play important roles in the pathogenesis of Staphylococcus aureus (S. aureus). Most Fibs can promote the aggregation of platelets during infection, but the extracellular fibrinogen-binding protein (Efb) is an exception. It is reported that Efb can specifically bind fibrinogen and inhibit the aggregation of platelet with its N terminal. However, the biological significance of platelet aggregation inhibition in the infection caused by S. aureus is unclear until now. Here, we demonstrated that the persistence and aggregation of platelets were important for killing S. aureus in whole blood. It was found that the N terminal of Efb (EfbN) and platelets inhibitors could increase the survival of S. aureus in whole blood. The study in vivo also showed that EfbN and platelets inhibitors could reduce the killing of S. aureus and increase the lethality rate of S. aureus in the acute infection mouse model.

Truncated Autoinducing Peptide Conjugates Selectively Recognize and Kill Staphylococcus aureus.

PubMed

Tsuchikama, Kyoji; Shimamoto, Yasuhiro; Anami, Yasuaki

2017-06-09

The accessory gene regulator (agr) of Staphylococcus aureus coordinates various pathogenic events and is recognized as a promising therapeutic target for virulence control. S. aureus utilizes autoinducing peptides (AIPs), cyclic-peptide signaling molecules, to mediate the agr system. Despite the high potency of synthetic AIP analogues in agr inhibition, the potential of AIP molecules as a delivery vehicle for antibacterial agents remains unexplored. Herein, we report that truncated AIP scaffolds can be fused with fluorophore and cytotoxic photosensitizer molecules without compromising their high agr inhibitory activity, binding affinity to the receptor AgrC, or cell specificity. Strikingly, a photosensitizer-AIP conjugate exhibited 16-fold greater efficacy in a S. aureus cell-killing assay than a nontargeting analogue. These findings highlight the potential of truncated AIP conjugates as useful chemical tools for in-depth biological studies and as effective anti-S. aureus agents.

Memory Th1 Cells Are Protective in Invasive Staphylococcus aureus Infection

PubMed Central

Lalor, Stephen J.; Leech, John M.; O’Keeffe, Kate M.; Mac Aogáin, Micheál; O’Halloran, Dara P.; Lacey, Keenan A.; Tavakol, Mehri; Hearnden, Claire H.; Fitzgerald-Hughes, Deirdre; Humphreys, Hilary; Fennell, Jérôme P.; van Wamel, Willem J.; Foster, Timothy J.; Geoghegan, Joan A.; Lavelle, Ed C.; Rogers, Thomas R.; McLoughlin, Rachel M.

2015-01-01

Mechanisms of protective immunity to Staphylococcus aureus infection in humans remain elusive. While the importance of cellular immunity has been shown in mice, T cell responses in humans have not been characterised. Using a murine model of recurrent S. aureus peritonitis, we demonstrated that prior exposure to S. aureus enhanced IFNγ responses upon subsequent infection, while adoptive transfer of S. aureus antigen-specific Th1 cells was protective in naïve mice. Translating these findings, we found that S. aureus antigen-specific Th1 cells were also significantly expanded during human S. aureus bloodstream infection (BSI). These Th1 cells were CD45RO+, indicative of a memory phenotype. Thus, exposure to S. aureus induces memory Th1 cells in mice and humans, identifying Th1 cells as potential S. aureus vaccine targets. Consequently, we developed a model vaccine comprising staphylococcal clumping factor A, which we demonstrate to be an effective human T cell antigen, combined with the Th1-driving adjuvant CpG. This novel Th1-inducing vaccine conferred significant protection during S. aureus infection in mice. This study notably advances our understanding of S. aureus cellular immunity, and demonstrates for the first time that a correlate of S. aureus protective immunity identified in mice may be relevant in humans. PMID:26539822

Prevalence and Characterization of Staphylococcus aureus Strains in the Pork Chain Supply in Chile.

PubMed

Velasco, Valeria; Vergara, José L; Bonilla, Ana M; Muñoz, Javier; Mallea, Alejandra; Vallejos, Diego; Quezada-Aguiluz, Mario; Campos, Jorge; Rojas-García, Pedro

2018-05-01

The detection of methicillin-resistant Staphylococcus aureus (MRSA) and other emerging strains in meat-producing animals and retail meat has increased the risk of contamination of food. The aim of this study was to determine the prevalence and characterize S. aureus strains isolated from the pork chain supply in Chile. A total of 487 samples were collected: 332 samples from pigs at farms and slaughterhouses (nasal, n = 155; skin, n = 177); 85 samples from carcasses at slaughterhouses; and 70 meat samples at supermarkets and retail stores. The isolation of S. aureus was carried out by selective enrichment and culture media. Biochemical testing (API ® Staph) and PCR (detection of the nuc and mecA genes) were used to confirm S. aureus and MRSA strains. The agglutination test was used to determine the protein PBP2'. Enterotoxins (SEA, SEB, SEC, SED) were determined by agglutination test and the se genes by PCR method. Oxacillin and cefoxitin susceptibility testing were carried out using the diffusion method. The overall prevalence of S. aureus in the pork meat supply was 33.9%. A higher prevalence was detected on carcasses (56.5%), in pigs sampled at farms (40.6%) than in pigs sampled at slaughterhouses (23.3%) and in nonpackaged retail meat (43.1%) than packaged retail meat (5.3%) (p ≤ 0.05). No significant differences (p > 0.05) were found between the prevalence in pigs (28.3%) and pork meat (32.9%) and between natural pig farming (33.3%) and conventional production (52.8%). The mecA gene and the protein PBP2' were not detected in S. aureus strains. Two S. aureus strains exhibited oxacillin and cefoxitin resistance, and one S. aureus strain was resistant to cefoxitin. One S. aureus strain isolated from a meat sample was positive for enterotoxin SEB. Although the mecA gene was not detected, oxacillin-resistant and seb-producing S. aureus strains were detected, which represent a risk in the pork chain supply.

Preventing Community-Associated Methicillin-Resistant "Staphylococcus aureus" among Student Athletes

ERIC Educational Resources Information Center

Many, Patricia S.

2008-01-01

Methicillin-resistant "Staphylococcus aureus" (MRSA) was once thought to be a bacterium causing infections in only hospitalized patients. However, a new strain of MRSA has emerged among healthy individuals who have not had any recent exposure to a hospital or to medical procedures. This new strain is known as "community-associated…

Topical Antimicrobial Treatments Can Elicit Shifts to Resident Skin Bacterial Communities and Reduce Colonization by Staphylococcus aureus Competitors

PubMed Central

SanMiguel, Adam J.; Meisel, Jacquelyn S.; Horwinski, Joseph; Zheng, Qi

2017-01-01

ABSTRACT The skin microbiome is a complex ecosystem with important implications for cutaneous health and disease. Topical antibiotics and antiseptics are often employed to preserve the balance of this population and inhibit colonization by more pathogenic bacteria. However, despite their widespread use, the impact of these interventions on broader microbial communities remains poorly understood. Here, we report the longitudinal effects of topical antibiotics and antiseptics on skin bacterial communities and their role in Staphylococcus aureus colonization resistance. In response to antibiotics, cutaneous populations exhibited an immediate shift in bacterial residents, an effect that persisted for multiple days posttreatment. By contrast, antiseptics elicited only minor changes to skin bacterial populations, with few changes to the underlying microbiota. While variable in scope, both antibiotics and antiseptics were found to decrease colonization by commensal Staphylococcus spp. by sequencing- and culture-based methods, an effect which was highly dependent on baseline levels of Staphylococcus. Because Staphylococcus residents have been shown to compete with the skin pathogen S. aureus, we also tested whether treatment could influence S. aureus levels at the skin surface. We found that treated mice were more susceptible to exogenous association with S. aureus and that precolonization with the same Staphylococcus residents that were previously disrupted by treatment reduced S. aureus levels by over 100-fold. In all, the results of this study indicate that antimicrobial drugs can alter skin bacterial residents and that these alterations can have critical implications for cutaneous host defense. PMID:28630195

Staphylococcus aureus carriage at admission predicts early-onset pneumonia after burn trauma.

PubMed

Fournier, A; Voirol, P; Krähenbühl, M; Bonnemain, C-L; Fournier, C; Dupuis-Lozeron, E; Pantet, O; Pagani, J-L; Revelly, J-P; Sadeghipour, F; Eggimann, P; Que, Y-A

2017-03-01

Early-onset pneumonia (EOP) is frequent after burn trauma, increasing morbidity in the critical resuscitation phase, which may preclude early aggressive management of burn wounds. Currently, however, preemptive treatment is not recommended. The aim of this study was to identify predictive factors for EOP that may justify early empirical antibiotic treatment. Data for all burn patients requiring ≥4 h mechanical ventilation (MV) who were admitted between January 2001 and October 2012 were extracted from the hospital's computerized information system. We reviewed EOP episodes (≤7 days) among patients who underwent endotracheal aspiration (ETA) within 5 days after admission. Univariate and multivariate analyses were performed to identify independent factors associated with EOP. Logistic regression was used to identify factors predicting EOP development. During the study period, 396 burn patients were admitted. ETA was performed within 5 days in 204/290 patients receiving ≥4 h MV. One hundred and eight patients developed EOP; 47 cases were caused by Staphylococcus aureus, 37 by Haemophilus influenzae, and 23 by Streptococcus pneumoniae. Among the 33 patients showing S. aureus positivity on ETA samples, 16 (48.5 %) developed S. aureus EOP. Among the 156 S. aureus non-carriers, 16 (10.2 %) developed EOP. Staphylococcus aureus carriage independently predicted EOP (p < 0.0001). We identified S. aureus carriage as an independent and strong predictor of EOP. As rapid point-of-care testing for S. aureus is readily available, we recommend testing of all patients at admission for burn trauma and the consideration of early preemptive treatment in all positive patients. Further studies are needed to evaluate this new strategy.

Lugol's solution eradicates Staphylococcus aureus biofilm in vitro.

PubMed

Grønseth, Torstein; Vestby, Lene K; Nesse, Live L; Thoen, Even; Habimana, Olivier; von Unge, Magnus; Silvola, Juha T

2017-12-01

The aim of the study was to evaluate the antibacterial efficacy of Lugol's solution, acetic acid, and boric acid against Staphylococcus aureus biofilm. The efficacy of Lugol's solution 1%, 0.1%, and 0.05%, acetic acid 5% or boric acid 4.7% for treatment of Staphylococcus aureus biofilm in vitro was tested using 30 clinical strains. Susceptibility in the planktonic state was assessed by disk diffusion test. Antiseptic effect on bacteria in biofilm was evaluated by using a Biofilm-oriented antiseptic test (BOAT) based on metabolic activity, a biofilm bactericidal test based on culturing of surviving bacteria and confocal laser scanning microscopy combined with LIVE/DEAD staining. In the planktonic state, all tested S. aureus strains were susceptible to Lugol's solution and acetic acid, while 27 out of 30 tested strains were susceptible to boric acid. In biofilm the metabolic activity was significantly reduced following exposure to Lugol's solution and 5% acetic acid, while boric acid exposure led to no significant changes in metabolic activities. In biofilm, biocidal activity was observed for Lugol's solution 1% (30/30), 0.1% (30/30), and 0.05% (26/30). Acetic acid and boric acid showed no bactericidal activity in this test. Confocal laser scanning microscopy, assessed in 4/30 strains, revealed significantly fewer viable biofilm bacteria with Lugol's solution (1% p < 0.001, 0.1% p = 0.001 or 0.05% p = 0.001), acetic acid 5% for 10 min (p = 0.001) or 30 min (p = 0.015), but not for acetic acid for 1 min or boric acid. Lugol's solution 1.0% and 0.1% effectively eradicated S. aureus in biofilm and could be an alternative to conventional topical antibiotics where S. aureus biofilm is suspected such as external otitis, pharyngitis and wounds. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparison of survivability of Staphylococcus aureus and spores of Aspergillus niger on commonly used floor materials.

PubMed

Gupta, Mridula; Bisesi, Michael; Lee, Jiyoung

2017-07-01

The survivability of Staphylococcus aureus and spores of Aspergillus niger was compared on 5 common floor materials. Floor materials were inoculated with a known concentration of S aureus and spores of A niger on day 0. Their survivability was measured on days, 2, 7, 14, and 28 by bulk rinsate method and enumerated using culture-based method. The difference in change of S aureus levels was statistically significant for all tested days (P < .001) for all floor materials. Vinyl composition tile (VCT) and porcelain tile (PT) had statistically similar survivability and differed statistically from carpets. On both VCT and PT, positive growth for S aureus occurred by day 2 (1-1.7 log 10 ), declined slightly (0.1 to -0.2 log 10 ) by day 7, and remained positive until day 28. However, S aureus was undetected by day 7 on both carpets. A niger spores were undetected on residential broadloom carpet and rubber-backed commercial carpet after day 2 but survived on VCT, PT, and wood until day 28. Floor materials with hard and smooth surfaces, such as VCT and PT, can allow survival of S aureus and A niger for up to 4 weeks. It may imply that floor materials can play a major role in preserving microbial contaminants in the built environment. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Targeting the host-pathogen interface for treatment of Staphylococcus aureus infection.

PubMed

Park, Bonggoo; Liu, George Y

2012-03-01

Recent emergence of methicillin-resistant Staphylococcus aureus both within and outside healthcare settings has accelerated the use of once reserved last line antibiotics such as vancomycin. With increased use of antibiotics, there has been a rapid rise in the rate of resistance development to the anti-MRSA drugs. As the antibiotic pipeline becomes strained, alternative strategies are being sought for future treatment of S. aureus. Here, we review several novel anti-staphylococcal strategies that, unlike conventional antibiotics, do not target essential gene products elaborated by the pathogen. The approaches seek instead to weaken the S. aureus defense by neutralizing its virulence factors or boosting host immunity. Other strategies target commensal bacteria that naturally colonize the human host to inhibit S. aureus colonization. Ultimately, the aim is to shift the balance between host defense and pathogen virulence in favor of inhibition of S. aureus pathogenic activities.

Staphylococcus aureus Complex in the Straw-Colored Fruit Bat (Eidolon helvum) in Nigeria.

PubMed

Olatimehin, Ayodele; Shittu, Adebayo O; Onwugamba, Francis C; Mellmann, Alexander; Becker, Karsten; Schaumburg, Frieder

2018-01-01

Bats are economically important animals and serve as food sources in some African regions. They can be colonized with the Staphylococcus aureus complex, which includes Staphylococcus schweitzeri and Staphylococcus argenteus . Fecal carriage of S. aureus complex in the straw-colored fruit bat ( Eidolon helvum ) has been described. However, data on their transmission and adaptation in animals and humans are limited. The aim of this study was to investigate the population structure of the S. aureus complex in E. helvum and to assess the geographical spread of S. aureus complex among other animals and humans. Fecal samples were collected from E. helvum in Obafemi Awolowo University, Ile-Ife, Nigeria. The isolates were characterized by antimicrobial susceptibility testing, spa typing and multilocus sequence typing (MLST). Isolates were screened for the presence of lukS / lukF -PV and the immune evasion cluster ( scn, sak, chp ) which is frequently found in isolates adapted to the human host. A Neighbor-Joining tree was constructed using the concatenated sequences of the seven MLST genes. A total of 250 fecal samples were collected and 53 isolates were included in the final analysis. They were identified as S. aureus ( n = 28), S. schweitzeri ( n = 11) and S. argenteus ( n = 14). Only one S. aureus was resistant to penicillin and another isolate was intermediately susceptible to tetracycline. The scn, sak , and chp gene were not detected. Species-specific MLST clonal complexes (CC) were detected for S. aureus (CC1725), S. argenteus (CC3960, CC3961), and S. schweitzeri (CC2463). STs of S. schweitzeri from this study were similar to STs from bats in Nigeria (ST2464) and Gabon (ST1700) or from monkey in Côte d'Ivoire (ST2058, ST2072). This suggests host adaptation of certain clones to wildlife mammals with a wide geographical spread in Africa. In conclusion, there is evidence of fecal carriage of members of S. aureus complex in E. helvum . S. schweitzeri from bats in

Methicillin-Resistant and -Susceptible Staphylococcus aureus Sequence Type 398 in Pigs and Humans

PubMed Central

van Belkum, Alex; Peeters, Justine K.; van Leeuwen, Willem B.; van Duijkeren, Engeline; Huijsdens, Xander W.; Spalburg, Emile; de Neeling, Albert J.; Verbrugh, Henri A.

2008-01-01

Methicillin-resistant Staphylococcus aureus sequence type 398 (ST398 MRSA) was identified in Dutch pigs and pig farmers. ST398 methicillin-susceptible S. aureus circulates among humans at low frequency (0.2%) but was isolated in 3 human cases of bacteremia (2.1%; p = 0.026). Although its natural host is probably porcine, ST398 MRSA likely causes infections in humans. PMID:18325267

Clonal profile, virulence and resistance of Staphylococcus aureus isolated from sheep milk.

PubMed

Martins, Katheryne Benini; Faccioli-Martins, Patricia Yoshida; Riboli, Danilo Flávio Moraes; Pereira, Valéria Cataneli; Fernandes, Simone; Oliveira, Aline A; Dantas, Ariane; Zafalon, Luiz Francisco; da Cunha, Maria de Lourdes Ribeiro de Souza

2015-06-01

The objective of this study was to characterize the clonal profile, virulence factors and antimicrobial resistance, particularly oxacillin resistance, of Staphylococcus aureus isolated from sheep milk. Milk samples were collected from all teats for the California Mastitis Test (CMT), somatic cell count, identification of S. aureus, investigation in these strains of genes encoding toxins (sea, seb, sec, sed, tst), biofilm (icaA, icaC, icaD, bap), leukocidin (luk-PV) oxacillin resistance by mecA gene detection and susceptibility testing (12 antibiotics). Messenger RNA expression was evaluated by RT-PCR in isolates carrying toxin and biofilm genes. Biofilm formation was also evaluated phenotypically by adherence to polystyrene plates. The clonal profile of S. aureus was investigated by pulsed-field gel electrophoresis. A total of 473 milk samples were collected from 242 animals on three farms and 20 S. aureus strains were isolated and none carried the mecA gene. The two sec gene-positive isolates and the isolates carrying the tst and luk-PV genes were positive by RT-PCR. Staphylococcus aureus isolated from the three flocks studied showed high susceptibility to the drugs tested and none was biofilm producer, indicating that biofilm formation was not a virulence factor causing infection by these strains. The typing of 17 S. aureus isolates revealed the presence of a common clone on the three farms studied, and the presence and expression of the sec and tst genes in one strain of this clone suggest the possible acquisition of virulence genes by this clone, a fact that is important for animal health and food hygiene.

Real-time quantitative PCR of Staphylococcus aureus and application in restaurant meals.

PubMed

Berrada, H; Soriano, J M; Mañes, J; Picó, Y

2006-01-01

Staphylococcus aureus is considered the second most common pathogen to cause outbreaks of food poisoning, exceeded only by Campylobacter. Consumption of foods containing this microorganism is often identified as the cause of illness. In this study, a rapid, reliable, and sensitive real-time quantitative PCR was developed and compared with conventional culture methods. Real-time quantitative PCR was carried out by purifying DNA extracts of S. aureus with a Staphylococcus sample preparation kit and quantifying it in the LightCycler system with hybridization probes. The assay was linear from a range of 10 to 10(6) S. aureus cells (r2 > 0.997). The PCR reaction presented an efficiency of >85%. Accuracy of the PCR-based assay, expressed as percent bias, was around 13%, and the precision, expressed as a percentage of the coefficient of variation, was 7 to 10%. Intraday and interday variability were studied at 10(2) CFU/g and was 12 and 14%, respectively. The proposed method was applied to the analysis of 77 samples of restaurant meals in Valencia (Spain). In 11.6% of samples S. aureus was detected by real-time quantitative PCR, as well as by the conventional microbiological method. An excellent correspondence between real-time quantitative PCR and microbiological numbers (CFU/g) was observed with deviations of < 28%.

Nickel allergy and relationship with Staphylococcus aureus in atopic dermatitis.

PubMed

Bogdali, Anna M; Anna, Bogdali M; Grazyna, Antoszczyk; Wojciech, Dyga; Aleksander, Obtulowicz; Anna, Bialecka; Andrzej, Kasprowicz; Zofia, Magnowska; Krystyna, Obtulowicz

2016-01-01

The increase of nickel air pollution is supposed to frequent side effects of nickel action related to virulence potential of Staphylococcus aureus in patients with nickel allergy in atopic dermatitis. The goal was to investigate the relationship between nickel allergy and infection by S. aureus in atopic dermatitis. Nickel allergy was confirmed in atopic patients and excluded in healthy volunteers using patch testing. Infection by S. aureus was tested in atopic patients and healthy volunteers by use of API Staph system. The specific IgE for staphylococcal enterotoxin A and B were measured. Secretion of IFN-g, IL-2, IL-13 by PBMC under nickel sulfate and the enterotoxins A and B stimulations were studied with ELISpot. We found the increased number of infections by S. aureus in atopic patients with nickel allergy in comparison to atopic patients and healthy volunteers without nickel allergy. The elevated secretion of IL-2 under nickel sulfate stimulation in vitro was exclusively found in atopic patients with nickel allergy infected by S. aureus. Our data suggest that nickel allergy and infection by S. aureus are linked in atopic dermatitis. Copyright © 2015 Elsevier GmbH. All rights reserved.

A sensitive gold nanoparticle-based colorimetric aptasensor for Staphylococcus aureus.

PubMed

Yuan, Jinglei; Wu, Shijia; Duan, Nuo; Ma, Xiaoyuan; Xia, Yu; Chen, Jie; Ding, Zhansheng; Wang, Zhouping

2014-09-01

In this study, a gold nanoparticle-based colorimetric aptasensor for Staphylococcus aureus (S. aureus) using tyramine signal amplification (TSA) technology has been developed. First, the biotinylated aptamer specific for S. aureus was immobilized on the surface of the wells of the microtiter plate via biotin-avidin binding. Then, the target bacteria (S. aureus), biotinylated-aptamer-streptavidin-HRP conjugates, biotinylated tyramine, hydrogen peroxide and avidin-catalase were successively introduced into the wells of the microtiter plate. After that, the existing catalase consumed the hydrogen peroxide. Finally, the freshly prepared gold (III) chloride trihydrate was added, the color of the reaction production would be changed and the absorbance at 550 nm could be measured with a plate reader. Under optimized conditions, there was a linear relationship between the absorbance at 550 nm and the concentration of S. aureus over the range from 10 to 10(6) cfu mL(-1) (with an R² of 0.9947). The limit of the developed method was determined to be 9 cfu mL(-1). Copyright © 2014 Elsevier B.V. All rights reserved.

Methicillin-resistant staphylococcus aureus isolates in a hospital of shanghai.

PubMed

Wang, Xiaoguang; Ouyang, Lin; Luo, Lingfei; Liu, Jiqian; Song, Chiping; Li, Cuizhen; Yan, Hongjing; Wang, Ping

2017-01-24

Methicillin-resistant Staphylococcus aureus (MRSA) strains are now common both in the health care setting and in the community. Active surveillance is critical for MRSA control and prevention. Specimens of patients (200 patients with 1119 specimens) as well as medical staff and hospital setting (1000 specimens) were randomly sampled in a level 2 hospital in Shanghai from September 2011 to August 2012. Isolation, cultivation and identification of S. aureus were performed. Totally, 67 S. aureus strains were isolated. 32 S. aureus strains were isolated from patient samples; 13 (13/32, 40.6%) of the 32 S. aureus isolates were MRSA; sputum sample and patients in the department of general internal medicine were the most frequent specimen and patient group for S. aureus strains isolation. Remaining 35 S. aureus strains were isolated from the medical staff and hospital setting; 20 (20/35, 57.1%) of the 35 S. aureus isolates were MRSA; specimens sampled from doctors and nurses' hands and nose and hospital facilities were the most frequent samples to isolate S. aureus. Resistant and virulent genes detection showed that, all 33 MRSA strains were mecA positive which accounts for 49.3% of the 67 S. aureus strains; 38 isolates were Panton-Valentine leukocidin (PVL) gene positive which accounts for 56.7% of the 67 S. aureus strains; and 17 (17/67, 25.4%) isolates are mecA and PVL genes dual positive. Multidrug-resistant strains of MRSA and PVL positive S. aureus are common in patients, medical staff and hospital setting, the potential health threat is worthy of our attention.

Vesicle formation as a result of interaction between polymorphonuclear neutrophils and Staphylococcus aureus biofilm.

PubMed

Chebotar, Igor' V; Konchakova, Evgenia D; Maianskii, Andrey N

2013-08-01

Staphylococcus aureus, a major opportunistic pathogen, is a leading cause of biofilm-related infections in clinical practice. Staphylococcal biofilms are highly resistant to antibacterial medicines and immune effector cells. The main result of our work is the discovery of nano-vesicles in the supernatant of the human neutrophil-S. aureus biofilm system. We also found that phospholipase C treatment causes complete destruction of these vesicles. While the addition of proteinase K led to a partial structural disorganization of the vesicles, DNase treatment did not influence the vesicle structure. These observations allowed us to conclude that phospholipids and proteins play a structure-forming role in the formation of these nano-vesicles. The vesicles demonstrated anti-biofilm activities when tested against Staphylococcus epidermidis (strains 178M and 328/5) biofilms, but were ineffective for S. aureus (strains 5983/2, 5663 and 18A) biofilms.

Targeting Staphylococcus aureus Toxins: A Potential form of Anti-Virulence Therapy

PubMed Central

Kong, Cin; Neoh, Hui-min; Nathan, Sheila

2016-01-01

Staphylococcus aureus is an opportunistic pathogen and the leading cause of a wide range of severe clinical infections. The range of diseases reflects the diversity of virulence factors produced by this pathogen. To establish an infection in the host, S. aureus expresses an inclusive set of virulence factors such as toxins, enzymes, adhesins, and other surface proteins that allow the pathogen to survive under extreme conditions and are essential for the bacteria’s ability to spread through tissues. Expression and secretion of this array of toxins and enzymes are tightly controlled by a number of regulatory systems. S. aureus is also notorious for its ability to resist the arsenal of currently available antibiotics and dissemination of various multidrug-resistant S. aureus clones limits therapeutic options for a S. aureus infection. Recently, the development of anti-virulence therapeutics that neutralize S. aureus toxins or block the pathways that regulate toxin production has shown potential in thwarting the bacteria’s acquisition of antibiotic resistance. In this review, we provide insights into the regulation of S. aureus toxin production and potential anti-virulence strategies that target S. aureus toxins. PMID:26999200

Antimicrobial Activity of Essential Oils Against Staphylococcus aureus in Fresh Sheep Cheese.

PubMed

Amatiste, Simonetta; Sagrafoli, Daniele; Giacinti, Giuseppina; Rosa, Giulia; Carfora, Virginia; Marri, Nicla; Tammaro, Andreana; Bovi, Emanuela; Rosati, Remo

2014-08-28

Essential oils (EOs) are aromatic oily liquids extracted from different parts of specific plants, well known especially for their aromatic and antibacterial properties. Nowadays, EOs are exploited in the food sector mainly for their aromatic properties. Thanks to their antimicrobial activity, however, they could also be used as additives to increase the safety and the shelf-life of food products. Aim of this study was to assess the antimicrobial activity of Thymus vulgaris L. oil and of Origanum vulgare L. oil against Staphylococcus aureus both in vitro and on fresh cheese, and to determine whether the use of EOs can modify the microbiological and/or chemical-physical properties of the products. The antimicrobial activity against S. aureus in vitro was assessed by preparation of the aromatogram (diffusion in agar test), minimum inhibitory concentration test and minimum bactericidal concentration assessment. Raw sheep milk was experimentally contaminated with a strain of S. aureus ATCC 25922 and was used to produce three types of fresh cheese: without EOs, with thyme and oregano EOs (both EOs at a concentration of 1:1000). The samples were analysed on the day of production, after three and seven days. The results obtained from the tests showed that the concentration of S. aureus and the counts of lactic flora remained unchanged for all types of cheese. Even the chemical-physical parameters were constant. The results of inhibition tests on the cheese disagree with those relating to the in vitro tests. Most likely this is due to the ability of EOs to disperse in the lipids the food: the higher the fat content is, the lower the oil fraction will be able to exert the antimicrobial activity.

Egg yolk-free Baird-Parker medium for the accelerated enumeration of foodborne Staphylococcus aureus.

PubMed Central

Lachica, R V

1984-01-01

A simplified procedure is described for the accelerated enumeration of foodborne Staphylococcus aureus. This involves the replacement of egg yolk in the Baird-Parker medium with Tween 80 and MgCl2. These compounds, along with pyruvate, allow the recovery of stressed cells of S. aureus on a medium which contains potassium tellurite, LiCl, and glycine as selective agents. Black colonies are identified as S. aureus by the simplified thermonuclease test. PMID:6542337

Staphylococcus aureus nasal decolonization in joint replacement surgery reduces infection.

PubMed

Hacek, Donna M; Robb, William J; Paule, Suzanne M; Kudrna, James C; Stamos, Van Paul; Peterson, Lance R

2008-06-01

Surgical site infections (SSIs) with Staphylococcus aureus are a recognized adverse event of hip and knee replacements. We evaluated the impact of a program to detect S. aureus nasal carriers before surgery with preoperative decolonization (using mupirocin twice daily for 5 days prior to surgery) of carriers. Nasal swab samples were obtained from patients prior to surgery from 8/1/2003 through 2/28/2005. Samples were tested using real-time PCR technology to detect S. aureus. The group that developed S. aureus SSI was compared to a combined concurrent and historical control for one year following the operation. S. aureus caused 71% of SSIs in the combined control groups. Of the 1495 surgical candidates evaluated, 912 (61.0%) were screened for S. aureus; 223 of those screened (24.5%) were positive and then decolonized with mupirocin. Among the 223 positive and decolonized patients, three (1.3%) developed a SSI. Among the 689 screen-negative patients, four (0.6%) developed SSIs for an overall rate of 0.77%. Among the 583 control patients who were not screened or decolonized, 10 (1.7%) developed S. aureus SSIs. SSIs from other organisms were 0.44% and 0.69%, respectively. Level III, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Draft Genome Sequence of Staphylococcus aureus Strain HD1410, Isolated from a Persistent Nasal Carrier

PubMed Central

Boutin, Sébastien; Dalpke, Alexander; Heeg, Klaus; Zanger, Philipp

2018-01-01

ABSTRACT We report here the draft genome sequence of a Staphylococcus aureus strain isolated from the nares of an 18-year-old female healthy persistent-carrier individual, and it was used to investigate S. aureus-specific immune responses in colonized and noncolonized individuals. PMID:29748411

Contamination of public transports by Staphylococcus aureus and its carriage by biomedical students: point-prevalence, related risk factors and molecular characterization of methicillin-resistant strains.

PubMed

Mendes, Â; Martins da Costa, P; Rego, D; Beça, N; Alves, C; Moreira, T; Conceição, T; Aires-de-Sousa, M

2015-08-01

To analyse the contamination of public transports by Staphylococcus aureus and assess its carriage by biomedical students, focussing on the point-prevalence, related risk factors and molecular characterization of methicillin-resistant strains. Cross-sectional survey. Methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) isolated from handrails of buses (n = 112) and trains (n = 79) circulating in Porto and from nasal swabs of local university students (n = 475) were quantified, characterized by molecular typing methods and related to possible risk factors. The MRSA prevalence in buses (16.1%) was not significantly different from trains (8.9%). There was also no identifiable association between the counts of MSSA and MRSA in buses and trains and the number of travellers in each sampling day, specific routes (including those passing by main hospitals) or other risk factors. Of the students, 37.1% carried S. aureus, and having a part-time job or smoking were found to be risk factors for carriage. EMRSA-15 (ST22-SCCmecIVh) was the prevalent MRSA clonal lineage, found not only in the buses (n = 14) and trains (n = 2) but also in the single MRSA-carrier among the students. The characteristics of the community-associated Southwest Pacific MRSA clone were found in a single ST30-IVa isolate, which may suggest a recent SCCmec acquisition by an MSSA background in the community. The spread of EMRSA-15, a common hospital-associated lineage, among different public transports and as a nasal coloniser is of concern and warrants adequate public health control measures. Copyright © 2015 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Architecture of a Species: Phylogenomics of Staphylococcus aureus.

PubMed

Planet, Paul J; Narechania, Apurva; Chen, Liang; Mathema, Barun; Boundy, Sam; Archer, Gordon; Kreiswirth, Barry

2017-02-01

A deluge of whole-genome sequencing has begun to give insights into the patterns and processes of microbial evolution, but genome sequences have accrued in a haphazard manner, with biased sampling of natural variation that is driven largely by medical and epidemiological priorities. For instance, there is a strong bias for sequencing epidemic lineages of methicillin-resistant Staphylococcus aureus (MRSA) over sensitive isolates (methicillin-sensitive S. aureus: MSSA). As more diverse genomes are sequenced the emerging picture is of a highly subdivided species with a handful of relatively clonal groups (complexes) that, at any given moment, dominate in particular geographical regions. The establishment of hegemony of particular clones appears to be a dynamic process of successive waves of replacement of the previously dominant clone. Here we review the phylogenomic structure of a diverse range of S. aureus, including both MRSA and MSSA. We consider the utility of the concept of the 'core' genome and the impact of recombination and horizontal transfer. We argue that whole-genome surveillance of S. aureus populations could lead to better forecasting of antibiotic resistance and virulence of emerging clones, and a better understanding of the elusive biological factors that determine repeated strain replacement. Copyright © 2016. Published by Elsevier Ltd.

Dysbiosis and Staphylococcus aureus Colonization Drives Inflammation in Atopic Dermatitis.

PubMed

Kobayashi, Tetsuro; Glatz, Martin; Horiuchi, Keisuke; Kawasaki, Hiroshi; Akiyama, Haruhiko; Kaplan, Daniel H; Kong, Heidi H; Amagai, Masayuki; Nagao, Keisuke

2015-04-21

Staphylococcus aureus skin colonization is universal in atopic dermatitis and common in cancer patients treated with epidermal growth factor receptor inhibitors. However, the causal relationship of dysbiosis and eczema has yet to be clarified. Herein, we demonstrate that Adam17(fl/fl)Sox9-(Cre) mice, generated to model ADAM17-deficiency in human, developed eczematous dermatitis with naturally occurring dysbiosis, similar to that observed in atopic dermatitis. Corynebacterium mastitidis, S. aureus, and Corynebacterium bovis sequentially emerged during the onset of eczematous dermatitis, and antibiotics specific for these bacterial species almost completely reversed dysbiosis and eliminated skin inflammation. Whereas S. aureus prominently drove eczema formation, C. bovis induced robust T helper 2 cell responses. Langerhans cells were required for eliciting immune responses against S. aureus inoculation. These results characterize differential contributions of dysbiotic flora during eczema formation, and highlight the microbiota-host immunity axis as a possible target for future therapeutics in eczematous dermatitis. Copyright © 2015 Elsevier Inc. All rights reserved.

Dysbiosis and Staphylococcus aureus colonization drives inflammation in atopic dermatitis

PubMed Central

Kobayashi, Tetsuro; Glatz, Martin; Horiuchi, Keisuke; Kawasaki, Hiroshi; Akiyama, Haruhiko; Kaplan, Daniel H.; Kong, Heidi H.; Amagai, Masayuki; Nagao, Keisuke

2015-01-01

Summary Staphylococcus aureus skin colonization is universal in atopic dermatitis and common in cancer patients treated with epidermal growth factor receptor inhibitors. However, the causal relationship of dysbiosis and eczema has yet to be clarified. Herein, we demonstrate that Adam17fl/flSox9-Cre mice, generated to model ADAM17-deficiency in human, developed eczematous dermatitis with naturally occurring dysbiosis, similar to that observed in atopic dermatitis. Corynebacterium mastitidis, S. aureus, and Corynebacterium bovis sequentially emerged during the onset of eczematous dermatitis, and antibiotic specific for these bacterial species almost completely reversed dysbiosis and eliminated skin inflammation. Whereas S. aureus prominently drove eczema formation, C. bovis induced robust T helper 2 cell responses. Langerhans cells were required for eliciting immune responses against S. aureus inoculation. These results characterize differential contributions of dysbiotic flora during eczema formation, and highlight the microbiota-host immunity axis as a possible target for future therapeutics in eczematous dermatitis. PMID:25902485

New drugs for methicillin-resistant Staphylococcus aureus: an update.

PubMed

Kumar, Krishan; Chopra, Sidharth

2013-07-01

Methicillin-resistant Staphylococcus aureus (MRSA) remains a leading cause of bacterial infections worldwide, with a dwindling repertoire of effective antimicrobials active against it. This review aims to provide an update on novel anti-MRSA molecules currently under pre-clinical and clinical development, with emphasis on their mechanism of action. This review is limited to molecules that target the pathogen directly and does not detail immunomodulatory anti-infectives.

Serological profiles in nursery piglets colonized with Staphylococcus aureus

PubMed Central

2013-01-01

At present, the immune response of pigs in relation to Staphylococcus aureus carriage is poorly understood. This study was aimed at investigating the dynamics of the anti-staphylococcal humoral immune response in methicillin-susceptible S. aureus (MSSA)-positive piglets and at assessing the effect of the experimental introduction of a methicillin-resistant S. aureus (MRSA) Sequence Type (ST) 398 strain. Therefore, serum samples were collected at different times from 31 weaned piglets originating from four different sows. Twenty-four out of the 31 piglets were challenged with MRSA ST398. The serum samples were analyzed for IgG antibodies to 39 S. aureus antigens, using a multiplex bead-based assay (xMAP technology, Luminex Corporation). Though antibody responses showed broad inter-individual variability, serological results appeared to be clustered by litter of origin. For most antigens, an age-related response was observed with an apparent increase in antibody titers directed against staphylococcal microbial surface components recognizing adhesive matrix molecules (MSCRAMM), which have been shown to play a role in S. aureus colonization. In most animals, antibody titers directed against staphylococcal toxins or immune-modulating proteins decreased with age, possibly reflecting the absence of bacterial invasion. The introduction of MRSA ST398 did not elicit a significant humoral immune reaction. This study describes, for the first time, the humoral immune response in weaned pigs colonized with S. aureus. PMID:23339425

Molecular Characterization of Staphylococcus aureus Isolates Transmitted between Patients with Buruli Ulcer.

PubMed

Amissah, Nana Ama; Chlebowicz, Monika A; Ablordey, Anthony; Sabat, Artur J; Tetteh, Caitlin S; Prah, Isaac; van der Werf, Tjip S; Friedrich, Alex W; van Dijl, Jan Maarten; Rossen, John W; Stienstra, Ymkje

2015-01-01

Buruli ulcer (BU) is a skin infection caused by Mycobacterium ulcerans. The wounds of most BU patients are colonized with different microorganisms, including Staphylococcus aureus. This study investigated possible patient-to-patient transmission events of S. aureus during wound care in a health care center. S. aureus isolates from different BU patients with overlapping visits to the clinic were whole-genome sequenced and analyzed by a gene-by-gene approach using SeqSphere(+) software. In addition, sequence data were screened for the presence of genes that conferred antibiotic resistance. SeqSphere(+) analysis of whole-genome sequence data confirmed transmission of methicillin resistant S. aureus (MRSA) and methicillin susceptible S. aureus among patients that took place during wound care. Interestingly, our sequence data show that the investigated MRSA isolates carry a novel allele of the fexB gene conferring chloramphenicol resistance, which had thus far not been observed in S. aureus.

Determinants of acquisition and carriage of Staphylococcus aureus in infancy.

PubMed

Peacock, Sharon J; Justice, Anita; Griffiths, D; de Silva, G D I; Kantzanou, M N; Crook, Derrick; Sleeman, Karen; Day, Nicholas P J

2003-12-01

Nasal carriage of Staphylococcus aureus is a major risk factor for invasive S. aureus disease. The aim of this study was to define factors associated with carriage. We conducted a prospective, longitudinal community-based study of infants and their mothers for a period of 6 months following delivery. The epidemiology of carriage was examined for 100 infant-mother pairs. Infant carriage varied significantly with age, falling from 40 to 50% during the first 8 weeks to 21% by 6 months. Determinants of infant S. aureus carriage included maternal carriage, breastfeeding, and number of siblings. Bacterial typing of S. aureus was performed by pulsed-field gel electrophoresis and multilocus sequence typing. The majority of individuals carried a single strain of S. aureus over time, and the mother was the usual source for colonizing isolates in infants. The effect of other components of the normal nasal flora on the development of S. aureus carriage was examined in 157 consecutive infants. Negative associations (putative bacterial interference) between S. aureus and other species occurred early in infancy but were not sustained. An increasing antistaphylococcal effect observed over time was not attributable to bacterial interference. S. aureus carriage in infants is likely to be determined by a combination of host, environmental, and bacterial factors, but bacterial interference does not appear to be an ultimate determinant of carrier status.

The origin of a methicillin-resistant Staphylococcus aureus isolate at a neonatal ward in Sweden-possible horizontal transfer of a staphylococcal cassette chromosome mec between methicillin-resistant Staphylococcus haemolyticus and Staphylococcus aureus.

PubMed

Berglund, C; Söderquist, B

2008-11-01

The first methicillin-resistant Staphylococcus aureus (MRSA) strain originated when a staphylococcal cassette chromosome mec (SCCmec) with the gene mecA was integrated into the chromosome of a susceptible S. aureus cell. The SCCmec elements are common among the coagulase-negative staphylococci, e.g. Staphylococcus haemolyticus, and these are considered to be potential SCCmec donors when new clones of MRSA arise. An outbreak of MRSA occurred at a neonatal intensive-care unit, and the isolates were all of sequence type (ST) 45, as characterized by multilocus sequence typing, but were not typeable with respect to SCCmec types I, II, III or IV. During the same time period, methicillin-resistant S. haemolyticus (MRSH) isolates identified in blood cultures at the same ward were found to be genotypically homogenous by pulsed-field gel electrophoresis, and did not carry a type I, II, III or IV SCCmec either. Thus, the hypothesis was raised that an SCCmec of MRSH had been transferred to a methicillin-susceptible S. aureus strain and thereby created a new clone of MRSA that caused the outbreak. This study showed that MRSA from the outbreak carried a ccrC and a class C mec complex that was also found among MRSH isolates. Partial sequencing of the mec complexes showed more than 99% homology, indicative of a common type V SCCmec. This finding may provide evidence for a recent horizontal transfer of an SCCmec from MRSH to an identified potential recipient, an ST45 methicillin-susceptible S. aureus strain, thereby creating a new clone of MRSA that caused the outbreak.

Methicillin-Resistant Staphylococcus aureus in Pork Production Shower Facilities ▿

PubMed Central

Leedom Larson, Kerry R.; Harper, Abby L.; Hanson, Blake M.; Male, Michael J.; Wardyn, Shylo E.; Dressler, Anne E.; Wagstrom, Elizabeth A.; Tendolkar, Shaliesh; Diekema, Daniel J.; Donham, Kelley J.; Smith, Tara C.

2011-01-01

As methicillin-resistant Staphylococcus aureus (MRSA) has been found in pigs, we sought to determine if MRSA is present in pork production shower facilities. In two production systems tested, 3% and 26% of shower samples were positive for MRSA. spa types identified included t034, t189, t753, and t1746. PMID:21097587

Loop-mediated isothermal amplification for detection of Staphylococcus aureus in dairy cow suffering from mastitis.

PubMed

Tie, Zhang; Chunguang, Wang; Xiaoyuan, Wei; Xinghua, Zhao; Xiuhui, Zhong

2012-01-01

To develop a rapid detection method of Staphylococcus aureus using loop-mediated isothermal amplification (LAMP), four specific primers were designed according to six distinct sequences of the nuc gene. In addition, the specificity and sensitivity of LAMP were verified and compared with those of PCR. Results showed that the LAMP reaction was completed within 45 min at 62.5°C, and ladder bands were appeared in LAMP products analyzed by gel electrophoresis. After adding 1x SYBR Green l, the positive reaction tube showed green color and the negative reaction tube remained orange, indicating that the LAMP has high specificity. The minimal detectable concentration of LAMP was 1 × 10² CFU/mL and that of PCR was 1 × 10⁴ CFU/mL, indicating that the LAMP was 100 times more sensitive than the PCR. The LAMP method for detection of Staphylococcus aureus has many advantages, such as simple operation, high sensitivity, high specificity, and rapid analysis. Therefore, this method is more suitable for the rapid on-site detection of Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus in public transportation vehicles (buses): another piece to the epidemiologic puzzle.

PubMed

Lutz, Jonathan K; van Balen, Joany; Crawford, John Mac; Wilkins, John R; Lee, Jiyoung; Nava-Hoet, Rocio C; Hoet, Armando E

2014-12-01

Little is known about the occurrence and epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in public transportation in the United States. This research sought to determine the background prevalence and phenotypic and genotypic characteristics of MRSA strains circulating on buses from a large, metropolitan transportation agency. Electrostatic wipes were used to collect 237 surface samples from 40 buses randomly selected from July-October 2010. Six samples were collected from each bus immediately postservice and before any cleaning and disinfection. Positive isolates were analyzed for antibiotic resistance, staphylococcal cassette chromosome mec (SCCmec) type, and pulsed-field gel electrophoresis; and potential epidemiologic factors were examined. Of the buses, 68% (27/40) were contaminated with S aureus, and 63% (25/40) were contaminated with MRSA. Seats and seat rails were the surfaces most frequently contaminated, followed by the back door and stanchions. Most (62.9%) of the MRSA isolates were classified as community-associated MRSA clones (SCCmec type IV), and 22.9% were health care-associated MRSA clones (SCCmec type II). Of the MRSA strains, 65% (5/20) were multidrug resistant. MRSA was frequently isolated from commonly touched surfaces in buses serving both hospital and community routes. Phenotypic and genotypic analysis demonstrated that buses may be effective mixing vessels for MRSA strains of both community and health care-associated origin. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Staphylococcus aureus Shifts toward Commensalism in Response to Corynebacterium Species

PubMed Central

Ramsey, Matthew M.; Freire, Marcelo O.; Gabrilska, Rebecca A.; Rumbaugh, Kendra P.; Lemon, Katherine P.

2016-01-01

Staphylococcus aureus–human interactions result in a continuum of outcomes from commensalism to pathogenesis. S. aureus is a clinically important pathogen that asymptomatically colonizes ~25% of humans as a member of the nostril and skin microbiota, where it resides with other bacteria including commensal Corynebacterium species. Commensal Corynebacterium spp. are also positively correlated with S. aureus in chronic polymicrobial diabetic foot infections, distinct from acute monomicrobial S. aureus infections. Recent work by our lab and others indicates that microbe–microbe interactions between S. aureus and human skin/nasal commensals, including Corynebacterium species, affect S. aureus behavior and fitness. Thus, we hypothesized that S. aureus interactions with Corynebacterium spp. diminish S. aureus virulence. We tested this by assaying for changes in S. aureus gene expression during in vitro mono- versus coculture with Corynebacterium striatum, a common skin and nasal commensal. We observed a broad shift in S. aureus gene transcription during in vitro growth with C. striatum, including increased transcription of genes known to exhibit increased expression during human nasal colonization and decreased transcription of virulence genes. S. aureus uses several regulatory pathways to transition between commensal and pathogenic states. One of these, the quorum signal accessory gene regulator (agr) system, was strongly inhibited in response to Corynebacterium spp. Phenotypically, S. aureus exposed to C. striatum exhibited increased adhesion to epithelial cells, reflecting a commensal state, and decreased hemolysin activity, reflecting an attenuation of virulence. Consistent with this, S. aureus displayed diminished fitness in experimental in vivo coinfection with C. striatum when compared to monoinfection. These data support a model in which S. aureus shifts from virulence toward a commensal state when exposed to commensal Corynebacterium species. PMID:27582729

Concentrations of Staphylococcus species in indoor air as associated with other bacteria, season, relative humidity, air change rate, and S. aureus-positive occupants.

PubMed

Madsen, Anne Mette; Moslehi-Jenabian, Saloomeh; Islam, Md Zohorul; Frankel, Mika; Spilak, Michal; Frederiksen, Margit W

2018-01-01

The aim of this study was to obtain knowledge about concentrations of Staphylococcus aureus, MRSA (methicillin-resistant S. aureus), and other Staphylococcus species in indoor air in Greater Copenhagen and about factors affecting the concentrations. The effects of season, temperature, relative humidity, air change rate (ACR), other bacterial genera, area per occupant, and presence of S. aureus-positive occupants were studied. In samples from 67 living rooms, S. hominis, S. warneri, S. epidermidis, and S. capitis were found in 13-25%; S. saprophyticus, S. cohnii, and S. pasteuri in 5-10%; and S. lugdunensis, S. haemolyticus, S. caprae, S. equorum, S. kloosii, S. pettenkoferi, S. simulans, and S. xylosus in less than 3%. Staphylococcus aureus were found in two of 67 living rooms: spa type t034 (an MRSA) was recovered from a farmhouse, while spa type t509 was found in an urban home. Two species, S. equorum and S. kloosii, were found only in the farmhouse. Staphylococcus was significantly associated with season with lowest concentration and richness in winter. Genera composition was associated with ACR with smaller fractions of Staphylococcus at higher ACR, while richness was significantly and negatively associated with area per occupant. Concentration of Staphylococcus correlated positively with the total concentration of bacteria, but negatively with the total concentration of other bacteria. The concentration of Staphylococcus was not significantly associated with concentrations of the other abundant genera Bacillus, Kocuria, and Micrococcus. In offices with S. aureus-positive occupants, airborne S. aureus was not found. In conclusion, Staphylococcus species constitute a considerable proportion of the airborne bacteria in the studied homes and offices. However, both S. aureus and MRSA had very low prevalence during all seasons. Thus, transmission of S. aureus and MRSA through the air in living rooms in Copenhagen is expected to be limited. The negative associations

Topical Antimicrobial Treatments Can Elicit Shifts to Resident Skin Bacterial Communities and Reduce Colonization by Staphylococcus aureus Competitors.

PubMed

SanMiguel, Adam J; Meisel, Jacquelyn S; Horwinski, Joseph; Zheng, Qi; Grice, Elizabeth A

2017-09-01

The skin microbiome is a complex ecosystem with important implications for cutaneous health and disease. Topical antibiotics and antiseptics are often employed to preserve the balance of this population and inhibit colonization by more pathogenic bacteria. However, despite their widespread use, the impact of these interventions on broader microbial communities remains poorly understood. Here, we report the longitudinal effects of topical antibiotics and antiseptics on skin bacterial communities and their role in Staphylococcus aureus colonization resistance. In response to antibiotics, cutaneous populations exhibited an immediate shift in bacterial residents, an effect that persisted for multiple days posttreatment. By contrast, antiseptics elicited only minor changes to skin bacterial populations, with few changes to the underlying microbiota. While variable in scope, both antibiotics and antiseptics were found to decrease colonization by commensal Staphylococcus spp. by sequencing- and culture-based methods, an effect which was highly dependent on baseline levels of Staphylococcus Because Staphylococcus residents have been shown to compete with the skin pathogen S. aureus , we also tested whether treatment could influence S. aureus levels at the skin surface. We found that treated mice were more susceptible to exogenous association with S. aureus and that precolonization with the same Staphylococcus residents that were previously disrupted by treatment reduced S. aureus levels by over 100-fold. In all, the results of this study indicate that antimicrobial drugs can alter skin bacterial residents and that these alterations can have critical implications for cutaneous host defense. Copyright © 2017 American Society for Microbiology.

Extensive Horizontal Gene Transfer during Staphylococcus aureus Co-colonization In Vivo

PubMed Central

McCarthy, Alex J.; Loeffler, Anette; Witney, Adam A.; Gould, Katherine A.; Lloyd, David H.; Lindsay, Jodi A.

2014-01-01

Staphylococcus aureus is a commensal and major pathogen of humans and animals. Comparative genomics of S. aureus populations suggests that colonization of different host species is associated with carriage of mobile genetic elements (MGE), particularly bacteriophages and plasmids capable of encoding virulence, resistance, and immune evasion pathways. Antimicrobial-resistant S. aureus of livestock are a potential zoonotic threat to human health if they adapt to colonize humans efficiently. We utilized the technique of experimental evolution and co-colonized gnotobiotic piglets with both human- and pig-associated variants of the lineage clonal complex 398, and investigated growth and genetic changes over 16 days using whole genome sequencing. The human isolate survived co-colonization on piglets more efficiently than in vitro. During co-colonization, transfer of MGE from the pig to the human isolate was detected within 4 h. Extensive and repeated transfer of two bacteriophages and three plasmids resulted in colonization with isolates carrying a wide variety of mobilomes. Whole genome sequencing of progeny bacteria revealed no acquisition of core genome polymorphisms, highlighting the importance of MGE. Staphylococcus aureus bacteriophage recombination and integration into novel sites was detected experimentally for the first time. During colonization, clones coexisted and diversified rather than a single variant dominating. Unexpectedly, each piglet carried unique populations of bacterial variants, suggesting limited transmission of bacteria between piglets once colonized. Our data show that horizontal gene transfer occurs at very high frequency in vivo and significantly higher than that detectable in vitro. PMID:25260585

Eradication of Methicillin-Resistant Staphylococcus aureus and of Enterobacteriaceae Expressing Extended-Spectrum Beta-Lactamases on a Model Pig Farm

PubMed Central

Kellner, Sophia Ricarda; Schulze-Geisthoevel, Sophia Veronika; Hack, Sylvia; Engelhart, Steffen; Bodenstein, Isabel; Al-Sabti, Nahed; Reif, Marion; Fimmers, Rolf; Körber-Irrgang, Barbara; Harlizius, Jürgen; Hoerauf, Achim; Exner, Martin; Bierbaum, Gabriele; Petersen, Brigitte

2015-01-01

Colonization of livestock with bacteria resistant to antibiotics is considered a risk for the entry of drug-resistant pathogens into the food chain. For this reason, there is a need for novel concepts to address the eradication of drug-resistant commensals on farms. In the present report, we evaluated the decontamination measures taken on a farm contaminated with methicillin-resistant Staphylococcus aureus (MRSA) and Enterobacteriaceae expressing extended-spectrum β-lactamases (ESBL-E). The decontamination process preceded the conversion from piglet breeding to gilt production. Microbiological surveillance showed that the decontamination measures eliminated the MRSA and ESBL-E strains that were detected on the farm before the complete removal of pigs, cleaning and disinfection of the stable, and construction of an additional stable meeting high-quality standards. After pig production was restarted, ESBL-E remained undetectable over 12 months, but MRSA was recovered from pigs and the environment within the first 2 days. However, spa (Staphylococcus aureus protein A gene) typing revealed acquisition of an MRSA strain (type t034) that had not been detected before decontamination. Interestingly, we observed that a farmworker who had been colonized with the prior MRSA strain (t2011) acquired the new strain (t034) after 2 months. In summary, this report demonstrates that decontamination protocols similar to those used here can lead to successful elimination of contaminating MRSA and ESBL-E in pigs and the stable environment. Nevertheless, decontamination protocols do not prevent the acquisition of new MRSA strains. PMID:26341200

Staphylococcus aureus induces hypoxia and cellular damage in porcine dermal explants

USDA-ARS?s Scientific Manuscript database

Methicillin-resistant Staphylococcus aureus (MRSA) can infect wounds and produce difficult-to- treat biofilms. To determine the extent that MRSA biofilms can deplete oxygen, change pH and damage host tissue, we developed a porcine dermal explant model on which we cultured GFP-labeled MRSA biofilms. ...

The Bicomponent Pore-Forming Leucocidins of Staphylococcus aureus

PubMed Central

Alonzo, Francis

2014-01-01

SUMMARY The ability to produce water-soluble proteins with the capacity to oligomerize and form pores within cellular lipid bilayers is a trait conserved among nearly all forms of life, including humans, single-celled eukaryotes, and numerous bacterial species. In bacteria, some of the most notable pore-forming molecules are protein toxins that interact with mammalian cell membranes to promote lysis, deliver effectors, and modulate cellular homeostasis. Of the bacterial species capable of producing pore-forming toxic molecules, the Gram-positive pathogen Staphylococcus aureus is one of the most notorious. S. aureus can produce seven different pore-forming protein toxins, all of which are believed to play a unique role in promoting the ability of the organism to cause disease in humans and other mammals. The most diverse of these pore-forming toxins, in terms of both functional activity and global representation within S. aureus clinical isolates, are the bicomponent leucocidins. From the first description of their activity on host immune cells over 100 years ago to the detailed investigations of their biochemical function today, the leucocidins remain at the forefront of S. aureus pathogenesis research initiatives. Study of their mode of action is of immediate interest in the realm of therapeutic agent design as well as for studies of bacterial pathogenesis. This review provides an updated perspective on our understanding of the S. aureus leucocidins and their function, specificity, and potential as therapeutic targets. PMID:24847020

A prospective cohort study of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus carriage in neonates: the role of maternal carriage and phenotypic and molecular characteristics

PubMed Central

Lin, Jialing; Wu, Chuanan; Yan, Chunrong; Ou, Qianting; Lin, Dongxin; Zhou, Junli; Ye, Xiaohua; Yao, Zhenjiang

2018-01-01

Background Staphylococcus aureus, particularly methicillin-resistant S. aureus (MRSA), in mothers can cause serious outcomes in neonates. We aimed to elucidate the associations of S. aureus and MRSA carriage between mothers and neonates. Methods A prospective cohort study was conducted between August and November 2015 in two hospitals in Shenzhen, China. Chinese pregnant women and their neonates who met the inclusion criteria were included in this study; samples and relevant information were collected. We assessed maternal–neonatal associations by using Poisson regression models. Results Overall, 1834 mothers and their neonates were included in this study. The prevalence of isolate carriage among the mothers was as follows: S. aureus (nasal, 25.8%; vaginal, 7.3%; and nasal and vaginal, 3.3%) and MRSA (nasal, 5.7%; vaginal, 1.7%; and nasal and vaginal, 0.5%). The incidences of S. aureus and MRSA carriage among neonates were 3.3% and 0.8%, respectively. Of the 21 maternal–neonatal pairs with S. aureus carriage, 14 were concordant pairs with the same phenotypic and molecular characteristics. After adjustment, the relative risks and 95% confidence intervals (CIs) between the S. aureus carriage of neonates and nasal S. aureus carriage, vaginal S. aureus carriage, and both nasal and vaginal S. aureus carriage of mothers were 2.8 (95% CI, 1.6–4.8), 7.1 (95% CI, 4.1–12.4), and 9.6 (95% CI, 4.2–22.4), respectively. Conclusion S. aureus carriage in mothers increases the risk for neonates. PMID:29731644

In Vitro Studies of Pharmacodynamic Properties of Vancomycin against Staphylococcus aureus and Staphylococcus epidermidis

PubMed Central

Löwdin, E.; Odenholt, I.; Cars, O.

1998-01-01

The bactericidal activities of vancomycin against two reference strains and two clinical isolates of Staphylococcus aureus and Staphylococcus epidermidis were studied with five different concentrations ranging from 2× to 64× the MIC. The decrease in the numbers of CFU at 24 h was at least 3 log10 CFU/ml for all strains. No concentration-dependent killing was observed. The postantibiotic effect (PAE) was determined by obtaining viable counts for two of the reference strains, and the viable counts varied markedly: 1.2 h for S. aureus and 6.0 h for S. epidermidis. The determinations of the PAE, the postantibiotic sub-MIC effect (PA SME), and the sub-MIC effect (SME) for all strains were done with BioScreen C, a computerized incubator for bacteria. The PA SMEs were longer than the SMEs for all strains tested. A newly developed in vitro kinetic model was used to expose the bacteria to continuously decreasing concentrations of vancomycin. A filter prevented the loss of bacteria during the experiments. One reference strain each of S. aureus and S. epidermidis and two clinical isolates of S. aureus were exposed to an initial concentration of 10× the MIC of vancomycin with two different half-lives (t1/2s): 1 or 5 h. The post-MIC effect (PME) was calculated as the difference in time for the bacteria to grow 1 log10 CFU/ml from the numbers of CFU obtained at the time when the MIC was reached and the corresponding time for an unexposed control culture. The difference in PME between the strains was not as pronounced as that for the PAE. Furthermore, the PME was shorter when a t1/2 of 5 h (approximate terminal t1/2 in humans) was used. The PMEs at t1/2s of 1 and 5 h were 6.5 and 3.6 h, respectively, for S. aureus. The corresponding figures for S. epidermidis were 10.3 and less than 6 h. The shorter PMEs achieved with a t1/2 of 5 h and the lack of concentration-dependent killing indicate that the time above the MIC is the parameter most important for the efficacy of vancomycin

Novel pleuromutilin derivatives with excellent antibacterial activity against Staphylococcus aureus.

PubMed

Xu, Peng; Zhang, Yuan-Yuan; Sun, Yong-Xue; Liu, Jian-Hua; Yang, Bing; Wang, Yu-Zhong; Wang, Yu-Liang

2009-06-01

Ten novel pleuromutilin derivatives with thioether moiety and heterocyclic carboxamide or chloroformate group in the side chain were synthesized and confirmed by (1)H NMR, IR and HRMS. The results of the antibacterial activity showed that the title compounds had excellent antibacterial activity against Staphylococcus aureus, among which the MIC of 5f reached 0.03125 microg/mL.

Clinical Management of Staphylococcus aureus Bacteremia

PubMed Central

Holland, Thomas L.; Arnold, Christopher; Fowler, Vance G.

2014-01-01

Importance Several management strategies may improve outcomes in patients with Staphylococcus aureus bacteremia (SAB). The strength of evidence supporting these management strategies, however, varies widely. Objective To perform a systematic review of the evidence for two unresolved questions involving management strategies for SAB: 1) is transesophageal echocardiography (TEE) necessary in all cases of SAB; and 2) what is the optimal antibiotic therapy for methicillin resistant Staphylococcus aureus (MRSA) bacteremia? Evidence acquisition A PubMed search from inception through May 2014 was performed to find studies that addressed the role of TEE in SAB. A second search of PubMed, EMBASE, and The Cochrane Library from 1/1/1990 to 5/28/2014 was performed to find studies that addressed antibiotic treatment of MRSA bacteremia. Studies that reported outcomes of systemic antibiotic therapy for MRSA bacteremia were included. All searches were augmented by review of bibliographic references from included studies. The quality of evidence was assessed using the GRADE system by consensus of independent evaluations by at least two authors. Results In 9 studies with a total of 3513 patients, use of TEE was associated with higher rates of diagnosis of endocarditis (14–25%) when compared with TTE (2–14%). Five studies proposed criteria to identify patients in whom TEE might safely be avoided. Only one high-quality trial of antibiotic therapy for MRSA bacteremia was identified from the 83 studies considered. Conclusions and relevance Most contemporary management strategies for SAB are based upon low quality evidence. TEE is indicated in most patients with SAB. It may be possible to identify a subset of SAB patients for whom TEE can be safely avoided. Vancomycin and daptomycin are the first-line antibiotic choices for MRSA bacteremia. Well-designed studies to address the management of SAB are desperately needed. PMID:25268440

Synergy of arbekacin-based combinations against vancomycin hetero-intermediate Staphylococcus aureus.

PubMed

Lee, Ji Young; Oh, Won Sup; Ko, Kwan Soo; Heo, Sang Taek; Moon, Chi Sook; Ki, Hyun Kyun; Kiem, Sungmin; Peck, Kyong Ran; Song, Jae Hoon

2006-04-01

This study was undertaken to evaluate the in vitro activities of arbekacin-based combination regimens against vancomycin hetero-intermediate Staphylococcus aureus (hetero-VISA). Combinations of arbekacin with vancomycin, rifampin, ampicillin-sulbactam, teicoplanin, or quinupristin-dalfopristin against seven hetero-VISA strains and two methicillin-resistant S. aureus strains were evaluated by the time-kill assay. The combinations of arbekacin with vancomycin, teicoplanin, or ampicillin-sulbactam showed the synergistic interaction against hetero-VISA strains. Data suggest that these arbekacin-based combination regimens may be useful candidates for treatment options of hetero-VISA infections.

Synergy of Arbekacin-based Combinations Against Vancomycin Hetero-intermediate Staphylococcus aureus

PubMed Central

Lee, Ji-Young; Oh, Won Sup; Ko, Kwan Soo; Heo, Sang Taek; Moon, Chi Sook; Ki, Hyun Kyun; Kiem, Sungmin; Peck, Kyong Ran

2006-01-01

This study was undertaken to evaluate the in vitro activities of arbekacin-based combination regimens against vancomycin hetero-intermediate Staphylococcus aureus (hetero-VISA). Combinations of arbekacin with vancomycin, rifampin, ampicillin-sulbactam, teicoplanin, or quinipristin-dalfopristin against seven hetero-VISA strains and two methicillin-resistant S. aureus strains were evaluated by the time-kill assay. The combinations of arbekacin with vancomycin, teicoplanin, or ampicillin-sulbactam showed the synergistic interaction against hetero-VISA strains. Data suggest that these arbekacin-based combination regimens may be useful candidates for treatment options of hetero-VISA infections. PMID:16614499

Risk Factors for Community-Associated Staphylococcus aureus Skin Infection in Children of Maui

PubMed Central

Seifried, Steven E

2012-01-01

The prevalence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infection, and Staphylococcus aureus (S. aureus) infection overall, has dramatically increased in the past 10 years. Children and Native Hawaiians and Pacific Islanders (NHPI) are disproportionately affected by CA-MRSA infection. The purpose of this case-control study was to identify risk factors for CA-S. aureus skin infections in children of Maui, Hawai‘i, as a foundation for reducing the transmission of these infections. Survey data were obtained from patients in pediatric clinician offices over an 8-month period. NHPI participants were well-represented as 58% of cases and 54% of controls. Chi-square analysis and logistic regression were used to identify risk factors. Significant risk factors predictive of infection among all participants were (a) skin abrasions or wounds, (b) household contact, and (c) overweight or obesity. Risk factors predictive of infection among NHPI were (a) skin abrasions or wounds, (b) antibiotic use within 6 months, (c) overweight or obesity, and (d) a history of eczema or other skin disorder. The role of overweight or obesity in S. aureus skin infections among NHPI has not been identified in previous research and indicates a focus for additional education. Further research is needed to better understand the role of eczema, antibiotic use, overweight and obesity, and socio-cultural factors in these infections. PMID:22900237

Nasal carriage of Staphylococcus aureus in Australian (pre-clinical and clinical) medical students.

PubMed

Stubbs, E; Pegler, M; Vickery, A; Harbour, C

1994-06-01

The nasal carriage of Staphylococcus aureus in 808 Australian medical students was studied. Five groups of students experienced varying degrees of clinical exposure in a hospital environment ranging from 0 to 42 months. The overall percentage of carriers among the five groups did not vary. However, with increasing clinical exposure there was a decrease in the percentage of isolates sensitive to all antibiotics tested, and an increase in the carriage of S. aureus resistant to three or more antibiotics. No carriers of methicillin-resistant S. aureus (MRSA) were detected. The comparative rates of S. aureus carriage between female and male students varied. The relevance of medical students as nasal carriers of S. aureus in the hospital environment today is discussed.

Institutional prescreening for detection and eradication of methicillin-resistant Staphylococcus aureus in patients undergoing elective orthopaedic surgery.

PubMed

Kim, David H; Spencer, Maureen; Davidson, Susan M; Li, Ling; Shaw, Jeremy D; Gulczynski, Diane; Hunter, David J; Martha, Juli F; Miley, Gerald B; Parazin, Stephen J; Dejoie, Pamela; Richmond, John C

2010-08-04

Surgical site infection has been identified as one of the most important preventable sources of morbidity and mortality associated with medical treatment. The purpose of the present study was to evaluate the feasibility and efficacy of an institutional prescreening program for the preoperative detection and eradication of both methicillin-resistant and methicillin-sensitive Staphylococcus aureus in patients undergoing elective orthopaedic surgery. Data were collected prospectively during a single-center study. A universal prescreening program, employing rapid polymerase chain reaction analysis of nasal swabs followed by an eradication protocol of intranasal mupirocin and chlorhexidine showers for identified carriers, was implemented. Surgical site infection rates were calculated and compared with a historical control period immediately preceding the start of the screening program. During the study period, 7019 of 7338 patients underwent preoperative screening before elective surgery, for a successful screening rate of 95.7%. One thousand five hundred and eighty-eight (22.6%) of the patients were identified as Staphylococcus aureus carriers, and 309 (4.4%) were identified as methicillin-resistant Staphylococcus aureus carriers. A significantly higher rate of surgical site infection was observed among methicillin-resistant Staphylococcus aureus carriers (0.97%; three of 309) compared with noncarriers (0.14%; seven of 5122) (p = 0.0162). Although a higher rate of surgical site infection was also observed among methicillin-sensitive Staphylococcus aureus carriers (0.19%; three of 1588) compared with noncarriers, this difference did not achieve significance (p = 0.709). Overall, thirteen cases of surgical site infection were identified during the study period, for an institutional infection rate of 0.19%. This rate was significantly lower than that observed during the control period (0.45%; twenty-four cases of surgical site infection among 5293 patients) (p = 0

Draft Genome Sequence of Staphylococcus aureus Strain HD1410, Isolated from a Persistent Nasal Carrier.

PubMed

Nurjadi, Dennis; Boutin, Sébastien; Dalpke, Alexander; Heeg, Klaus; Zanger, Philipp

2018-05-10

We report here the draft genome sequence of a Staphylococcus aureus strain isolated from the nares of an 18-year-old female healthy persistent-carrier individual, and it was used to investigate S. aureus -specific immune responses in colonized and noncolonized individuals. Copyright © 2018 Nurjadi et al.

Genotyping of Staphylococcus aureus in bovine mastitis and correlation to phenotypic characteristics.

PubMed

Artursson, Karin; Söderlund, Robert; Liu, Lihong; Monecke, Stefan; Schelin, Jenny

2016-09-25

Reducing the prevalence of mastitis caused by Staphylococcus aureus (S. aureus) is essential to improve animal health and reduce economic losses for farmers. The clinical outcome of acute mastitis and risk of progression to persistent mastitis can, at least to some extent, be related to genetic variants of the strain causing the infection. In the present study we have used microarrays to investigate the presence of virulence genes in S. aureus isolates from dairy cows with acute clinical mastitis (n=70) and correlated the findings to other genotypic and phenotypic characteristics. Among the most commonly found virulence factors were genes encoding several hemolysin types, leukocidins D and lukM/lukF-P83, clumping factors A and B, fibrinogen binding protein and fibronectin-binding protein A. Some virulence factors e.g. fibronectin-binding protein B and Staphylococcus aureus surface protein G were less common. Genes coding for several staphylococcal enterotoxins and toxic shock syndrome toxin-1 (TSST-1) were commonly found, especially in one major pulsotype. No beta-lactamase genes were found in any common pulsotype, while present in some rare pulsotypes, indicated to be of human origin. Production of TSST-1, enterotoxins, hemolysins and beta-lactamase could all be positively correlated to presence of the corresponding genes. This study reveals a number of genotypic differences and similarities among common and rare pulsotypes of S. aureus from cases of mastitis in Sweden. The results could help the design of diagnostic tools to guide on-farm interventions according to the expected impact on udder health from a specific S. aureus genotype. Copyright © 2016 Elsevier B.V. All rights reserved.

Dormant Cells of Staphylococcus aureus Are Resuscitated by Spent Culture Supernatant

PubMed Central

Pascoe, Ben; Dams, Lucy; Wilkinson, Tom S.; Harris, Llinos G.; Bodger, Owen; Mack, Dietrich; Davies, Angharad P.

2014-01-01

We describe the first in vitro model of dormancy in Staphylococcus aureus, showing that cells are generated which can be resuscitated by addition of spent medium supernatant taken from cultures of the same organism. Over 30 days, culturable counts in dormant cultures of S. aureus SH1000 fell from 106–107 cfu/ml to <10 cfu/ml as measured by the Most Probable Number method in liquid culture, while total counts as determined by microscopy, and supported by data from RT-qPCR, remained around 106–107 cells/ml. Supplementing cultures with 25–50% spent medium resulted in a >600-fold increase in bacterial growth. Resuscitation was a specific effect, greatly reduced by boiling or addition of trypsin to the spent supernatant. Supernatant also effected a reduction in lag phase of dormant cultures. SEM demonstrated the presence of small coccoid cells in dormant cultures. The results are similar to those seen with resuscitation promoting factors (Rpfs) in actinobacteria. This is the first time resuscitation has been demonstrated in Staphylococcus aureus, which is an important human pathogen. A better understanding of control and reactivation of dormant cells could lead to major improvements in managing staphylococcal infections; resuscitation could be an important step in restoring susceptibility to antibiotic treatment. PMID:24523858

Molecular mechanisms of methicillin resistance in Staphylococcus aureus.

PubMed

Domínguez, M A; Liñares, J; Martín, R

1997-09-01

Methicillin-resistant Staphylococcus aureus (MRSA) strains are among the most common nosocomial pathogens. The most significant mechanism of resistance to methicillin in this-species is the acquisition of a genetic determinant (mecA gene). However, resistance seems to have a more complex molecular basis, since additional chromosomal material is involved in such resistance. Besides, overproduction of penicillinase and/or alterations in the PBPs can contribute to the formation of resistance phenotypes. Genetic and environmental factors leading to MRSA are reviewed.

The amino acid sequence of Staphylococcus aureus penicillinase.

PubMed Central

Ambler, R P

1975-01-01

The amino acid sequence of the penicillinase (penicillin amido-beta-lactamhydrolase, EC 3.5.2.6) from Staphylococcus aureus strain PC1 was determined. The protein consists of a single polypeptide chain of 257 residues, and the sequence was determined by characterization of tryptic, chymotryptic, peptic and CNBr peptides, with some additional evidence from thermolysin and S. aureus proteinase peptides. A mistake in the preliminary report of the sequence is corrected; residues 113-116 are now thought to be -Lys-Lys-Val-Lys- rather than -Lys-Val-Lys-Lys-. Detailed evidence for the amino acid sequence has been deposited as Supplementary Publication SUP 50056 (91 pages) at the British Library (Lending Division), Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies may be obtained on the terms given in Biochem. J. (1975) 145, 5. PMID:1218078

Hypoxia-Inducible Factor 1-Regulated Lysyl Oxidase Is Involved in Staphylococcus aureus Abscess Formation

PubMed Central

Beerlage, Christiane; Greb, Jessica; Kretschmer, Dorothee; Assaggaf, Mohammad; Trackman, Philip C.; Hansmann, Martin-Leo; Bonin, Michael; Eble, Johannes A.; Peschel, Andreas; Brüne, Bernhard

2013-01-01

Hypoxia-inducible factor 1 (HIF-1) is the key transcription factor involved in the adaptation of mammals to hypoxia and plays a crucial role in cancer angiogenesis. Recent evidence suggests a leading role for HIF-1 in various inflammatory and infectious diseases. Here we describe the role of HIF-1 in Staphylococcus aureus infections by investigating the HIF-1-dependent host cell response. For this purpose, transcriptional profiling of HIF-1α-deficient HepG2 and control cells, both infected with Staphylococcus aureus, was performed. Four hours after infection, the expression of 190 genes, 24 of which were regulated via HIF-1, was influenced. LOX (encoding lysyl oxidase) was one of the upregulated genes with a potential impact on the course of S. aureus infection. LOX is an amine oxidase required for biosynthetic cross-linking of extracellular matrix components. LOX was upregulated in vitro in different cell cultures infected with S. aureus and also in vivo, in kidney abscesses of mice intravenously infected with S. aureus and in clinical skin samples from patients with S. aureus infections. Inhibition of LOX by β-aminopropionitrile (BAPN) did not affect the bacterial load in kidneys or blood but significantly influenced abscess morphology and collagenization. Our data provide evidence for a crucial role of HIF-1-regulated LOX in abscess formation. PMID:23649089

Antimicrobial Activity of Copaiba (Copaifera officinalis) and Pracaxi (Pentaclethra macroloba) Oils against Staphylococcus Aureus: Importance in Compounding for Wound Care.

PubMed

Guimarães, Anna Luísa Aguijar; Cunha, Elisa Alves; Matias, Fernanda Oliveira; Garcia, Patrícia Guedes; Danopoulos, Panagiota; Swikidisa, Rosita; Pinheiro, Vanessa Alves; Nogueira, Rodrigo José Lupatini

2016-01-01

The Amazon rainforest is the largest reserve of natural products in the world. Its rich biodiversity of medicinal plants has been utilized by local populations for hundreds of years for the prevention and treatment of various diseases and ailments. Oil extracts from plant species such as Copaifera officinalis and Pentaclethra macroloba are used in compounded formulations for their antiinflammatory, antimicrobial, emollient, moisturizing, and wound-healing activities. The objective of this study was to investigate the in vitro bacteriostatic effect of two Amazonian oils, Copaiba and Pracaxi, against Staphylococcus aureus, a clinically important microorganism responsible for wound infection, to support the use of these oils as novel natural products for compounded wound-treatment modalities. The antibacterial activity of Copaiba and Pracaxi oils against a standard strain of Staphylococcus aureus was assessed using broth microdilution to determine the Minimum Inhibitory Concentration and Minimum Bactericidal Concentration of the oil extracts. Copaiba oil demonstrated antibacterial activity against Staphylococcus aureus, with a Minimum Inhibitory Concentration of 0.3125 mg/mL and a Minimum Bactericidal Concentration of 0.3125 mg/mL. Conversely, Pracaxi oil failed to inhibit Staphylococcus aureus growth. While additional studies are required to further evaluate the antimicrobial activity of Pracaxi oil, even low concentrations of Copaiba oil effectively inhibited Staphylococcus aureus growth, supporting its potential use as a promising adjuvant in compounded topical formulations for wound and scar healing.

Galectin-3 Is a Target for Proteases Involved in the Virulence of Staphylococcus aureus.

PubMed

Elmwall, Jonas; Kwiecinski, Jakub; Na, Manli; Ali, Abukar Ahmed; Osla, Veronica; Shaw, Lindsey N; Wang, Wanzhong; Sävman, Karin; Josefsson, Elisabet; Bylund, Johan; Jin, Tao; Welin, Amanda; Karlsson, Anna

2017-07-01

Staphylococcus aureus is a major cause of skin and soft tissue infection. The bacterium expresses four major proteases that are emerging as virulence factors: aureolysin (Aur), V8 protease (SspA), staphopain A (ScpA), and staphopain B (SspB). We hypothesized that human galectin-3, a β-galactoside-binding lectin involved in immune regulation and antimicrobial defense, is a target for these proteases and that proteolysis of galectin-3 is a novel immune evasion mechanism. Indeed, supernatants from laboratory strains and clinical isolates of S. aureus caused galectin-3 degradation. Similar proteolytic capacities were found in Staphylococcus epidermidis isolates but not in Staphylococcus saprophyticus Galectin-3-induced activation of the neutrophil NADPH oxidase was abrogated by bacterium-derived proteolysis of galectin-3, and SspB was identified as the major protease responsible. The impact of galectin-3 and protease expression on S. aureus virulence was studied in a murine skin infection model. In galectin-3 +/+ mice, SspB-expressing S. aureus caused larger lesions and resulted in higher bacterial loads than protease-lacking bacteria. No such difference in bacterial load or lesion size was detected in galectin-3 -/- mice, which overall showed smaller lesion sizes than the galectin-3 +/+ animals. In conclusion, the staphylococcal protease SspB inactivates galectin-3, abrogating its stimulation of oxygen radical production in human neutrophils and increasing tissue damage during skin infection. Copyright © 2017 American Society for Microbiology.

Molecular Characterization of Staphylococcus aureus Isolates Transmitted between Patients with Buruli Ulcer

PubMed Central

Amissah, Nana Ama; Chlebowicz, Monika A.; Ablordey, Anthony; Sabat, Artur J.; Tetteh, Caitlin S.; Prah, Isaac; van der Werf, Tjip S.; Friedrich, Alex W.; van Dijl, Jan Maarten

2015-01-01

Background Buruli ulcer (BU) is a skin infection caused by Mycobacterium ulcerans. The wounds of most BU patients are colonized with different microorganisms, including Staphylococcus aureus. Methodology This study investigated possible patient-to-patient transmission events of S. aureus during wound care in a health care center. S. aureus isolates from different BU patients with overlapping visits to the clinic were whole-genome sequenced and analyzed by a gene-by-gene approach using SeqSphere+ software. In addition, sequence data were screened for the presence of genes that conferred antibiotic resistance. Principal Findings SeqSphere+ analysis of whole-genome sequence data confirmed transmission of methicillin resistant S. aureus (MRSA) and methicillin susceptible S. aureus among patients that took place during wound care. Interestingly, our sequence data show that the investigated MRSA isolates carry a novel allele of the fexB gene conferring chloramphenicol resistance, which had thus far not been observed in S. aureus. PMID:26360794

Methicillin-Resistant Staphylococcus aureus Prevalence among Captive Chimpanzees, Texas, USA, 20121

PubMed Central

Barnhart, Kirstin F.; Abee, Christian R.; Lambeth, Susan P.; Weese, J. Scott

2015-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) infection in humans and animals is concerning. In 2012, our evaluation of a captive chimpanzee colony in Texas revealed MRSA prevalence of 69%. Animal care staff should be aware of possible zoonotic MRSA transmission resulting from high prevalence among captive chimpanzees. PMID:26583847

Synergy between baicalein and penicillins against penicillinase-producing Staphylococcus aureus.

PubMed

Qian, Minyi; Tang, Shusheng; Wu, Congming; Wang, Yang; He, Tao; Chen, Tingting; Xiao, Xilong

2015-09-01

The combination of baicalein (the active constituent of Scutellaria baicalensis) with penicillin G/amoxicillin showed potent synergy against 20 clinical penicillinase-producing Staphylococcus aureus strains including 10 isolates that were additionally methicillin-resistant (MRSA). The fractional inhibitory concentration (FIC) indices of penicillins+baiclein ranged from 0.14 to 0.38. Baicalein protected penicillins (penicillin G and amoxicillin) from penicillinase and increased the susceptibility of penicillinase-supplemented S. aureus ATCC 29213 in a dose-dependent manner. The inhibition of penicillinase activity by baicalein should be responsible for the synergism and protective effect. These findings offer us good evidence that the penicillins combined with baicalein showed potent synergistic activity against penicillinase-producing S. aureus and penicillinase-producing MRSA in vitro and might provide promising implications for clinical treatment of these bacterial infections. Copyright © 2015 Elsevier GmbH. All rights reserved.

Staphylococcus aureus Redirects Central Metabolism to Increase Iron Availability

PubMed Central

Pishchany, Gleb; Whitwell, Corbin W; Torres, Victor J; Skaar, Eric P

2006-01-01

Staphylococcus aureus pathogenesis is significantly influenced by the iron status of the host. However, the regulatory impact of host iron sources on S. aureus gene expression remains unknown. In this study, we combine multivariable difference gel electrophoresis and mass spectrometry with multivariate statistical analyses to systematically cluster cellular protein response across distinct iron-exposure conditions. Quadruplicate samples were simultaneously analyzed for alterations in protein abundance and/or post-translational modification state in response to environmental (iron chelation, hemin treatment) or genetic (Δfur) alterations in bacterial iron exposure. We identified 120 proteins representing several coordinated biochemical pathways that are affected by changes in iron-exposure status. Highlighted in these experiments is the identification of the heme-regulated transport system (HrtAB), a novel transport system which plays a critical role in staphylococcal heme metabolism. Further, we show that regulated overproduction of acidic end-products brought on by iron starvation decreases local pH resulting in the release of iron from the host iron-sequestering protein transferrin. These findings reveal novel strategies used by S. aureus to acquire scarce nutrients in the hostile host environment and begin to define the iron and heme-dependent regulons of S. aureus. PMID:16933993

Certified Athletic Trainers' Knowledge of Methicillin-Resistant Staphylococcus aureus and Common Disinfectants

PubMed Central

Kahanov, Leamor; Gilmore, Elizabeth J.; Eberman, Lindsey E.; Roberts, Jeffrey; Semerjian, Tamar; Baldwin, Linda

2011-01-01

Context: Methicillin-resistant Staphylococcus aureus (MRSA) infections are increasingly common in athletic settings. The MRSA knowledge and infection-control practices of certified athletic trainers (ATs) and the cleanliness of the athletic training room are important factors in preventing MRSA infections. Objective: To assess knowledge of MRSA and the use of common disinfectants among ATs and to explore their infection-control practices. Design: Cross-sectional study. Setting: High school and collegiate athletic training rooms. Patients or Other Participants: A total of 163 ATs from National Collegiate Athletic Association Divisions I, II, and III and high schools, representing all 10 National Athletic Trainers' Association districts. Main Outcome Measure(s): Frequencies, analyses of variance, and χ2 tests were used to assess current practices and opinions and relationships between factors. Results: Methicillin-resistant Staphylococcus aureus was perceived as a national problem by 92% of respondents; 57% perceived MRSA as a problem in their practice setting. Most respondents had treated general infections (88%), staphylococcal infections (75%), and MRSA infections (57%). Male sex was associated with treating all 3 types of infections (χ2 test, P < .05). Noncurriculum education was associated with a lack of recognition of environmental issues as risk factors and with the use of isopropyl alcohol for disinfection (χ2 test, P < .05). For example, 10% of respondents did not recognize that contaminated whirlpools can be a source of MRSA infection. Respondents also incorrectly identified effective cleaning solutions. Thirty percent of respondents cleaned their hands frequently or sometimes before treating each athlete and 35% cleaned their hands sometimes, occasionally, or never after seeing each athlete. Conclusions: The majority of ATs were informed about MRSA and made correct disinfection choices. However, improvements are still needed, and not all ATs were using

Killing of Staphylococcus aureus via Magnetic Hyperthermia Mediated by Magnetotactic Bacteria

PubMed Central

Chen, Changyou; Chen, Linjie; Yi, Yong; Chen, Chuanfang

2016-01-01

Staphylococcus aureus is a common hospital and household pathogen. Given the emergence of antibiotic-resistant derivatives of this pathogen resulting from the use of antibiotics as general treatment, development of alternative therapeutic strategies is urgently needed. Here, we assess the feasibility of killing S. aureus cells in vitro and in vivo through magnetic hyperthermia mediated by magnetotactic bacteria that possess magnetic nanocrystals and demonstrate magnetically steered swimming. The S. aureus suspension was added to magnetotactic MO-1 bacteria either directly or after coating with anti-MO-1 polyclonal antibodies. The suspensions were then subjected to an alternating magnetic field (AMF) for 1 h. S. aureus viability was subsequently assessed through conventional plate counting and flow cytometry. We found that approximately 30% of the S. aureus cells mixed with uncoated MO-1 cells were killed after AMF treatment. Moreover, attachment between the magnetotactic bacteria and S. aureus increased the killing efficiency of hyperthermia to more than 50%. Using mouse models, we demonstrated that magnetic hyperthermia mediated by antibody-coated magnetotactic MO-1 bacteria significantly improved wound healing. These results collectively demonstrated the effective eradication of S. aureus both in vitro and in vivo, indicating the potential of magnetotactic bacterium-mediated magnetic hyperthermia as a treatment for S. aureus-induced skin or wound infections. PMID:26873320

Status of vaccine research and development of vaccines for Staphylococcus aureus.

PubMed

Giersing, Birgitte K; Dastgheyb, Sana S; Modjarrad, Kayvon; Moorthy, Vasee

2016-06-03

Staphylococcus aureus is a highly versatile gram positive bacterium that is resident as an asymptomatic colonizer on the skin and in the nasopharynx of approximately 30% of individuals. Nasopharyngeal colonization is a risk for acquiring S. aureus infections, which can cause a range of clinical symptoms that are commonly associated with skin and soft-tissue infections. The emergence of S. aureus strains that are highly resistant to antimicrobials has recently become a major public health concern. In low-income countries the incidence of S. aureus disease is highest in neonates and children up to one year of age and mortality rates are estimated to be up to 50%. In the United States, S. aureus infection accounts for approximately 300,000 hospitalizations per year. A vaccine against multi-drug resistant S. aureus, therefore, is urgently needed. Two vaccine candidates have previously been evaluated in late-stage clinical trials but have not demonstrated efficacy. At present, one vaccine candidate and two monoclonal antibody are undergoing clinical evaluation in target groups at high risk for S. aureus infection. This review provides an overview of current vaccine development efforts and presents the major technical and regulatory challenges to developing a licensed S. aureus vaccine. Copyright © 2016 World Health Organization. Published by Elsevier Ltd.. All rights reserved.

On the challenges of detecting whole Staphylococcus aureus cells with biosensors.

PubMed

Templier, V; Roupioz, Y

2017-11-01

Due to the increasing number of nosocomial infections and multidrug-resistant bacterial strains, Staphylococcus aureus is now a major worldwide concern. Rapid detection and characterization of this bacterium has become an important issue for biomedical applications. Biosensors are increasingly appearing as low-cost, easy-to-operate and fast alternatives for rapid detection. In this review, we will introduce the main characteristics of S. aureus and will focus on the interest of biosensors for a faster detection of whole S. aureus cells. In particular, we will review the most promising strategies in the choice of ligand for the design of selective and efficient biosensors. Their specific characteristics as well as their advantages and/or disadvantages will also be commented. © 2017 The Society for Applied Microbiology.

[Eradication of Staphylococcus aureus in carrier patients undergoing joint arthroplasty].

PubMed

Barbero Allende, José M; Romanyk Cabrera, Juan; Montero Ruiz, Eduardo; Vallés Purroy, Alfonso; Melgar Molero, Virginia; Agudo López, Rosa; Gete García, Luis; López Álvarez, Joaquín

2015-02-01

Prosthetic joint infection (PJI) is a complication with serious repercussions and its main cause is Staphylococcus aureus. The purpose of this study is to determine whether decolonization of S.aureus carriers helps to reduce the incidence of PJI by S.aureus. An S.aureus screening test was performed on nasal carriers in patients undergoing knee or hip arthroplasty between January and December 2011. Patients with a positive test were treated with intranasal mupirocin and chlorhexidine soap 5 days. The incidence of PJI was compared with patients undergoing the same surgery between January and December 2010. A total of 393 joint replacements were performed in 391 patients from the control group, with 416 joint replacements being performed in the intervention group. Colonization study was performed in 382 patients (91.8%), of which 102 were positive (26.7%) and treated. There was 2 PJI due S.aureus compared with 9 in the control group (0.5% vs 2.3%, odds ratio [OR]: 0.2, 95% confidence interval [CI]: 0.4 to 2.3, P=.04). In our study, the detection of colonization and eradication of S.aureus carriers achieved a significant decrease in PJI due to S.aureus compared to a historical group. Copyright © 2013 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.

A systematic review of animal models for Staphylococcus aureus osteomyelitis

PubMed Central

Reizner, W.; Hunter, J.G.; O’Malley, N.T.; Southgate, R.D.; Schwarz, E.M.; Kates, S.L.

2015-01-01

Staphylococcus aureus (S. aureus) osteomyelitis is a significant complication for orthopaedic patients undergoing surgery, particularly with fracture fixation and arthroplasty. Given the difficulty in studying S. aureus infections in human subjects, animal models serve an integral role in exploring the pathogenesis of osteomyelitis, and aid in determining the efficacy of prophylactic and therapeutic treatments. Animal models should mimic the clinical scenarios seen in patients as closely as possible to permit the experimental results to be translated to the corresponding clinical care. To help understand existing animal models of S. aureus, we conducted a systematic search of PubMed & Ovid MEDLINE to identify in vivo animal experiments that have investigated the management of S. aureus osteomyelitis in the context of fractures and metallic implants. In this review, experimental studies are categorized by animal species and are further classified by the setting of the infection. Study methods are summarized and the relevant advantages and disadvantages of each species and model are discussed. While no ideal animal model exists, the understanding of a model’s strengths and limitations should assist clinicians and researchers to appropriately select an animal model to translate the conclusions to the clinical setting. PMID:24668594

Virulence potential of Staphylococcus aureus isolates from Buruli ulcer patients.

PubMed

Amissah, Nana Ama; Chlebowicz, Monika A; Ablordey, Anthony; Tetteh, Caitlin S; Prah, Isaac; van der Werf, Tjip S; Friedrich, Alex W; van Dijl, Jan Maarten; Stienstra, Ymkje; Rossen, John W

2017-06-01

Buruli ulcer (BU) is a necrotizing infection of the skin and subcutaneous tissue caused by Mycobacterium ulcerans. BU wounds may also be colonized with other microorganisms including Staphylococcus aureus. This study aimed to characterize the virulence factors of S. aureus isolated from BU patients. Previously sequenced genomes of 21 S. aureus isolates from BU patients were screened for the presence of virulence genes. The results show that all S. aureus isolates harbored on their core genomes genes for known virulence factors like α-hemolysin, and the α- and β-phenol soluble modulins. Besides the core genome virulence genes, mobile genetic elements (MGEs), i.e. prophages, genomic islands, pathogenicity islands and a Staphylococcal cassette chromosome (SCC) were found to carry different combinations of virulence factors, among them genes that are known to encode factors that promote immune evasion, superantigens and Panton-Valentine Leucocidin. The present observations imply that the S. aureus isolates from BU patients harbor a diverse repertoire of virulence genes that may enhance bacterial survival and persistence in the wound environment and potentially contribute to delayed wound healing. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

Antibacterial mode of action of violacein from Chromobacterium violaceum UTM5 against Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA).

PubMed

Aruldass, Claira Arul; Masalamany, Santhana Raj Louis; Venil, Chidambaram Kulandaisamy; Ahmad, Wan Azlina

2018-02-01

Violacein, violet pigment produced by Chromobacterium violaceum, has attracted much attention recently due to its pharmacological properties including antibacterial activity. The present study investigated possible antibacterial mode of action of violacein from C. violaceum UTM5 against Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) strains. Violet fraction was obtained by cultivating C. violaceum UTM5 in liquid pineapple waste medium, extracted, and fractionated using ethyl acetate and vacuum liquid chromatography technique. Violacein was quantified as major compound in violet fraction using HPLC analysis. Violet fraction displayed bacteriostatic activity against S. aureus ATCC 29213 and methicillin-resistant S. aureus ATCC 43300 with minimum inhibitory concentration (MIC) of 3.9 μg/mL. Fluorescence dyes for membrane damage and scanning electron microscopic analysis confirmed the inhibitory effect by disruption on membrane integrity, morphological alternations, and rupture of the cell membranes of both strains. Transmission electron microscopic analysis showed membrane damage, mesosome formation, and leakage of intracellular constituents of both bacterial strains. Mode of action of violet fraction on the cell membrane integrity of both strains was shown by release of protein, K + , and extracellular adenosine 5'-triphosphate (ATP) with 110.5 μg/mL, 2.34 μg/mL, and 87.24 ng/μL, respectively, at 48 h of incubation. Violet fraction was toxic to human embryonic kidney (HEK293) and human fetal lung fibroblast (IMR90) cell lines with LC 50 value of 0.998 ± 0.058 and 0.387 ± 0.002 μg/mL, respectively. Thus, violet fraction showed a strong antibacterial property by disrupting the membrane integrity of S. aureus and MRSA strains. This is the first report on the possible mode of antibacterial action of violet fraction from C. violaceum UTM5 on S. aureus and MRSA strains.

Antibiotic tolerance and the alternative lifestyles of Staphylococcus aureus.

PubMed

Bui, Long M G; Conlon, Brian P; Kidd, Stephen P

2017-02-28

Staphylococcus aureus has an incredible ability to survive, either by adapting to environmental conditions or defending against exogenous stress. Although there are certainly important genetic traits, in part this ability is provided by the breadth of modes of growth S. aureus can adopt. It has been proposed that while within their host, S. aureus survives host-generated and therapeutic antimicrobial stress via alternative lifestyles: a persister sub-population, through biofilm growth on host tissue or by growing as small colony variants (SCVs). Key to an understanding of chronic and relapsing S. aureus infections is determining the molecular basis for its switch to these quasi-dormant lifestyles. In a multicellular biofilm, the metabolically quiescent bacterial community additionally produces a highly protective extracellular polymeric substance (EPS). Furthermore, there are bacteria within a biofilm community that have an altered physiology potentially equivalent to persister cells. Recent studies have directly linked the cellular ATP production by persister cells as their key feature and the basis for their tolerance of a range of antibiotics. In clinical settings, SCVs of S. aureus have been observed for many years; when cultured, these cells form non-pigmented colonies and are approximately ten times smaller than their counterparts. Various genotypic factors have been identified in attempts to characterize S. aureus SCVs and different environmental stresses have been implicated as important inducers. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Population Genomics of Reduced Vancomycin Susceptibility in Staphylococcus aureus

PubMed Central

Rishishwar, Lavanya; Kraft, Colleen S.

2016-01-01

ABSTRACT The increased prevalence of vancomycin-intermediate Staphylococcus aureus (VISA) is an emerging health care threat. Genome-based comparative methods hold great promise to uncover the genetic basis of the VISA phenotype, which remains obscure. S. aureus isolates were collected from a single individual that presented with recurrent staphylococcal bacteremia at three time points, and the isolates showed successively reduced levels of vancomycin susceptibility. A population genomic approach was taken to compare patient S. aureus isolates with decreasing vancomycin susceptibility across the three time points. To do this, patient isolates were sequenced to high coverage (~500×), and sequence reads were used to model site-specific allelic variation within and between isolate populations. Population genetic methods were then applied to evaluate the overall levels of variation across the three time points and to identify individual variants that show anomalous levels of allelic change between populations. A successive reduction in the overall levels of population genomic variation was observed across the three time points, consistent with a population bottleneck resulting from antibiotic treatment. Despite this overall reduction in variation, a number of individual mutations were swept to high frequency in the VISA population. These mutations were implicated as potentially involved in the VISA phenotype and interrogated with respect to their functional roles. This approach allowed us to identify a number of mutations previously implicated in VISA along with allelic changes within a novel class of genes, encoding LPXTG motif-containing cell-wall-anchoring proteins, which shed light on a novel mechanistic aspect of vancomycin resistance. IMPORTANCE The emergence and spread of antibiotic resistance among bacterial pathogens are two of the gravest threats to public health facing the world today. We report the development and application of a novel population genomic

Population structure and antimicrobial profile of Staphylococcus aureus strains associated with bovine mastitis in China.

PubMed

Zhang, Lili; Li, Yuchen; Bao, Hongduo; Wei, Ruicheng; Zhou, Yan; Zhang, Hui; Wang, Ran

2016-08-01

Staphylococcus aureus is a significant bacterial pathogen associated with bovine mastitis. The aim of the present study was to investigate and characterize of S. aureus strains isolated from the milk of cows suffering from mastitis in the mid-east of China. Among the 200 milk samples analyzed, 58 were positive for S. aureus, of these isolates, 11 isolates were methicillin-resistant Staphylococcus aureus (MRSA). All of the 58 S. aureus strains were classified in agr group I, while seven different sequence type (ST) patterns were identified and among them the most common was ST630 followed by ST188. All of the S. aureus isolates belonging to ST630 were resistant to more than four antimicrobials, and 22.2% of isolates belonging to ST188 were resistant to eight antimicrobials. Interestingly, while strong biofilm producers demonstrated higher resistance to multiple antimicrobials, they exhibited lower intracellular survival rates. The results of this study illustrated the distribution, antimicrobial susceptibility profiles, genotype, and the ability of biofilm production and mammary epithelial cells invasion of these S. aureus isolates. This study can provide the basis for the development of a disease prevention program in dairy farms to reduce the potential risk in both animal and human health. Copyright © 2016 Elsevier Ltd. All rights reserved.

Identification of pathogenic factors potentially involved in Staphylococcus aureus keratitis using proteomics.

PubMed

Khan, Shamila; Cole, Nerida; Hume, Emma B H; Garthwaite, Linda L; Nguyen-Khuong, Terry; Walsh, Bradley J; Willcox, Mark D P

2016-10-01

Staphylococcus is a leading cause of microbial keratitis, characterized by destruction of the cornea by bacterial exoproteins and host-associated factors. The aim of this study was to compare extracellular and cell-associated proteins produced by two different isolates of S. aureus, a virulent clinical isolate (Staph 38) and a laboratory strain (Staphylococcus aureus 8325-4) of weaker virulence in the mouse keratitis model. Proteins were analyzed using 2D polyacrylamide gel electrophoresis and identified by subsequent mass spectrometry. Activity of staphylococcal adhesins was assessed by allowing strains to bind to various proteins adsorbed onto polymethylmethacrylate squares. Thirteen proteins in the extracellular fraction and eight proteins in the cell-associated fractions after bacterial growth were produced in increased amounts in the clinical isolate Staph 38. Four of these proteins were S. aureus virulence factor adhesins, fibronectin binding protein A, staphopain, glyceraldehyde-3-phosphate dehydrogenase 2 and extracellular adherence protein. The clinical isolate Staph 38 adhered to a greater extent to all mammalian proteins tested, indicating the potential of the adhesins to be active on its surface. Other proteins with increased expression in Staph 38 included potential moonlighting proteins and proteins involved in transcription or translation. This is the first demonstration of the proteome of S. aureus isolates from keratitis. These results indicate that the virulent clinical isolate produces more potentially important virulence factors compared to the less virulent laboratory strain and these may be associated with the ability of a S. aureus strain to cause more severe keratitis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Antimicrobial blue light inactivation of Methicillin-resistant Staphylococcus aureus

NASA Astrophysics Data System (ADS)

Wang, Yucheng; Dai, Tianhong; Gu, Ying

2016-10-01

Background: With the increasing emergence of multidrug-resistant (MDR) bacterial strains, there is a pressing need for the development of alternative treatment for infections. Antimicrobial blue light (aBL) has provided a simple and effective approach. Methods: We first investigated the effectiveness of aBL (415 nm) inactivation of USA300 LAClux (a communityacquired Methicillin-resistant Staphylococcus aureus strain) both in the planktonic and biofilm forms. The survival of the bacteria in suspensions was determined by serial dilution and that of the biofilm-embedded bacteria was determined by bioluminescence quantification. Using a mouse model of thermal burn infected with USA300 LAClux, we further assessed the effectiveness of aBL for treating localized infections. Bioluminescence imaging was performed to monitor in real time bacterial viability in vivo. Results: In vitro study showed that, for the planktonic counterpart of the bacteria or the 24-h-old biofilms, an irradiance of 55 mW/cm2 for 60 min resulted in a 4.61 log10 or 2.56 log10 inactivation, respectively. In vivo study using infected mouse burns demonstrated that a 2.56-log10 inactivation was achieved after 100-mW/cm2 irradiation for 62 min. Conclusions: aBL is a potential alternative approach for treating Methicillin-resistant Staphylococcus aureus infections.

Detection and Prevalence of Penicillin-Susceptible Staphylococcus aureus in the United States in 2013

PubMed Central

Doern, G. V.; Heilmann, K. P.; Miner, S.; Tendolkar, S.; Riahi, F.; Diekema, D. J.

2016-01-01

Using blaZ PCR as the “gold standard,” the sensitivities of CLSI penicillin zone edge and nitrocefin-based tests for β-lactamase production in Staphylococcus aureus were 64.5% and 35.5%, respectively, with specificity of 99.8% for both methods. In 2013, 13.5% of 3,083 S. aureus isolates from 31 U.S. centers were penicillin susceptible. PMID:26763960

Prevalence and characterization of methicillin-resistant Staphylococcus aureus carrying mecA or mecC and methicillin-susceptible Staphylococcus aureus in dairy sheep farms in central Italy.

PubMed

Giacinti, G; Carfora, V; Caprioli, A; Sagrafoli, D; Marri, N; Giangolini, G; Amoruso, R; Iurescia, M; Stravino, F; Dottarelli, S; Feltrin, F; Franco, A; Amatiste, S; Battisti, A

2017-10-01

Between January and May 2012, a total of 286 bulk tank milk samples from dairy sheep farms located in central Italy were tested for the presence of Staphylococcus aureus. One hundred fifty-three samples were positive for S. aureus (53.5%), with an average count of 2.53 log cfu/mL. A total of 679 S. aureus colonies were screened for methicillin resistance by the cefoxitin disk diffusion test, and 104 selected cefoxitin-susceptible isolates were also tested for their susceptibility to other antimicrobials representative of the most relevant classes active against Staphylococcus spp. by using the Kirby-Bauer disk diffusion method. Two methicillin-resistant Staphylococcus aureus (MRSA) isolates, carrying respectively the mecA and the mecC genes, were detected in 2 samples from 2 different farms (prevalence 0.7%). The mecA-positive MRSA isolate was blaZ positive, belonged to spa type t127, sequence type (ST)1, clonal complex (CC)1, carried a staphylococcal cassette chromosome mec (SCCmec) type IVa, and was phenotypically resistant to all the β-lactams tested and to erythromycin, streptomycin, kanamycin, and tetracycline. The mecC-positive MRSA isolate was negative for the chromosomally or plasmid-associated blaZ gene but positive for the blaZ allotype associated with SCCmec XI (blaZ-SCCmecXI), belonged to spa type 843, ST(CC)130, carried a SCCmec type XI, and was resistant only to β-lactams. Both MRSA were negative for the presence of specific immune-evasion and virulence genes such as those coding for the Panton-Valentine leucocidin, the toxic shock syndrome toxin 1, and the immune evasion cluster genes. Regarding the presence of the major S. aureus enterotoxin genes, the mecC-positive MRSA tested negative, whereas the ST (CC)1 mecA-positive MRSA harbored the seh gene. Among the 104 methicillin-susceptible S. aureus isolates examined for antimicrobial susceptibility, 63 (60.58%) were susceptible to all the antimicrobials tested, and 41 (39.42%) were resistant to at

Methicillin-susceptible, Doxycycline-resistant Staphylococcus aureus, Côte d’Ivoire

PubMed Central

Haus-Cheymol, Rachel; Dubrous, Philippe; Verret, Catherine; Spiegel, André; Bonnet, Richard; Bes, Michèle; Laurichesse, Henri; Beytout, Jean; Etienne, Jerome; Migliani, René; Koeck, Jean Louis

2007-01-01

We report 2 outbreaks of Panton-Valentine leukocidin–positive, doxycycline-resistant, methicillin-susceptible Staphylococcus aureus infections in French soldiers operating in Côte d’Ivoire. In a transssectional survey, nasal carriage of this strain was found in 2.9% of 273 soldiers about to be sent to Côte d’Ivoire and was associated with prior malaria prophylaxis with doxycycline. PMID:17552109

High Rates of Staphylococcus aureus USA400 Infection, Northern Canada

PubMed Central

Golding, George R.; Levett, Paul N.; McDonald, Ryan R.; Irvine, James; Quinn, Brian; Nsungu, Mandiangu; Woods, Shirley; Khan, Mohammad; Ofner-Agostini, Marianna

2011-01-01

Surveillance of Staphylococcus aureus infections in 3 northern remote communities of Saskatchewan was undertaken. Rates of methicillin-resistant infections were extremely high (146–482/10,000 population), and most (98.2%) were caused by USA400 strains. Although USA400 prevalence has diminished in the United States, this strain is continuing to predominate throughout many northern communities in Canada. PMID:21470471

Emergence in Asian Countries of Staphylococcus aureus with Reduced Susceptibility to Vancomycin

PubMed Central

Song, Jae-Hoon; Hiramatsu, Keiichi; Suh, Ji Yoeun; Ko, Kwan Soo; Ito, Teruyo; Kapi, Maria; Kiem, Sungmin; Kim, Yeon-Sook; Oh, Won Sup; Peck, Kyong Ran; Lee, Nam Yong

2004-01-01

To investigate the prevalence of Staphylococcus aureus with reduced susceptibility to vancomycin among methicillin-resistant S. aureus (MRSA) strains in Asian countries, a total of 1,357 clinical isolates of MRSA collected from 12 Asian countries were screened by using brain heart infusion agar plates containing 4 mg of vancomycin per liter. The presence of strains that were heterointermediately resistant to vancomycin (hVISA) was confirmed by population analysis. Of 347 (25.6%) MRSA isolates that grew on the screening agar plates, 58 isolates (4.3%) were hVISA. hVISA strains were found in India, South Korea, Japan, the Philippines, Singapore, Thailand, and Vietnam. However, neither vancomycin-intermediate S. aureus nor vancomycin-resistant S. aureus isolates were found among MRSA isolates from Asian countries in this survey. PMID:15561884

Antibody-Based Agents in the Management of Antibiotic-Resistant Staphylococcus aureus Diseases

PubMed Central

Speziale, Pietro; Rindi, Simonetta

2018-01-01

Staphylococcus aureus is a human pathogen that can cause a wide spectrum of diseases, including sepsis, pneumonia, arthritis, and endocarditis. Ineffective treatment of a number of staphylococcal infections with antibiotics is due to the development and spread of antibiotic-resistant strains following decades of antibiotic usage. This has generated renewed interest within the scientific community in alternative therapeutic agents, such as anti-S. aureus antibodies. Although the role of antibodies in the management of S. aureus diseases is controversial, the success of this pathogen in neutralizing humoral immunity clearly indicates that antibodies offer the host extensive protection. In this review, we report an update on efforts to develop antibody-based agents, particularly monoclonal antibodies, and their therapeutic potential in the passive immunization approach to the treatment and prevention of S. aureus infections. PMID:29533985

Transfer of mupirocin resistance from Staphylococcus haemolyticus clinical strains to Staphylococcus aureus through conjugative and mobilizable plasmids.

PubMed

Rossi, Ciro C; Ferreira, Natália C; Coelho, Marcus L V; Schuenck, Ricardo P; Bastos, Maria do Carmo de F; Giambiagi-deMarval, Marcia

2016-07-01

Coagulase-negative staphylococci are thought to act as reservoirs of antibiotic resistance genes that can be transferred to Staphylococcus aureus, thus hindering the combat of this bacterium. In this work, we analyzed the presence of plasmids conferring resistance to the antibiotic mupirocin-widely used to treat and prevent S. aureus infections in hospital environments-in nosocomial S. haemolyticus strains. About 12% of the 75 strains tested were resistant to mupirocin, and this phenotype was correlated with the presence of plasmids. These plasmids were shown to be diverse, being either conjugative or mobilizable, and capable of transferring mupirocin resistance to S. aureus Our findings reinforce that S. haemolyticus, historically and mistakenly considered as a less important pathogen, is a reservoir of resistance genes which can be transferred to other bacteria, such as S. aureus, emphasizing the necessity of more effective strategies to detect and combat this emergent opportunistic pathogen. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Management practices associated with presence of Staphylococcus aureus in bulk tank milk from Ohio dairy herds.

PubMed

da Costa, L B; Rajala-Schultz, P J; Schuenemann, G M

2016-02-01

Staphylococcus aureus is the most common contagious mastitis pathogen affecting cows worldwide. Practices to control this organism have been advocated for decades, and identification of risk factors in individual herds is crucial in prevention and control of Staph. aureus. The objectives of this paper were to estimate prevalence of Staph. aureus in Ohio dairies and to determine a potential association of herd characteristics and management practices with isolation of Staph. aureus in bulk tank milk. A questionnaire about herd characteristics, milking procedures, udder health, mastitis control, and biosecurity practices was mailed to 780 dairy producers; the response rate for the survey was 49%. Staphylococcus aureus prevalence was 48, 64, and 69% when 1, 2, or 3 samples of bulk tank milk from each herd were considered, respectively. Herds practicing prestrip, pre- and postmilking teat dip, and using a single towel per cow as part of the milking routine as well as herds where owners were involved in milking were at significantly reduced odds for detection of Staph. aureus in their bulk tank milk. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Human Staphylococcus aureus lineages among Zoological Park residents in Greece

PubMed Central

Drougka, E.; Foka, A.; Posantzis, D.; Giormezis, N.; Anastassiou, E.D.; Petinaki, E.; Spiliopoulou, I.

2015-01-01

Staphylococcus aureus is a part of the microbiota flora in many animal species. The clonal spread of S. aureus among animals and personnel in a Zoological Park was investigated. Samples were collected from colonized and infected sites among 32 mammals, 11 birds and eight humans. The genes mecA, mecC, lukF/lukS-PV (encoding Panton-Valentine leukocidin, PVL) and tst (toxic shock syndrome toxin-1) were investigated by PCR. Clones were defined by Multilocus Sequence Typing (MLST), spa type and Pulsed-Field Gel Electrophoresis (PFGE). Seven S. aureus isolates were recovered from four animals and one from an employee. All were mecA, mecC and tst–negative, whereas, one carried the PVL genes and was isolated from an infected Squirrel monkey. Clonal analysis revealed the occurrence of seven STs, eight PFGE and five spa types including ones of human origin. Even though a variety of genotypes were identified among S. aureus strains colonizing zoo park residents, our results indicate that colonization with human lineages has indeed occurred. PMID:26623381

Staphylococcus aureus surface contamination of mobile phones and presence of genetically identical strains on the hands of nursing personnel.

PubMed

Katsuse Kanayama, Akiko; Takahashi, Hiroshi; Yoshizawa, Sadako; Tateda, Kazuhiro; Kaneko, Akihiro; Kobayashi, Intetsu

2017-08-01

We investigated the genetic relatedness of Staphylococcus aureus isolates recovered from mobile phones and palms and fingers of users. Genetically identical isolates were detected from mobile phones and their user and multiple users, which is consistent with mobile phones serving as reservoirs of infection in the health care environment. These findings reinforce the need for hand hygiene prior to patient contact as the most effective intervention for preventing health care-associated infection. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Food compounds inhibit Staphylococcus aureus bacteria and the toxicity of Staphylococcus Enterotoxin A (SEA) associated with atopic dermatitis

USDA-ARS?s Scientific Manuscript database

Atopic dermatitis or eczema is characterized by skin rashes and itching is an inflammatory disease that affects 10-20% of children and 1-3% of adults. Staphylococcus aureus bacteria are present on the skin of nearly all patients with atopic dermatitis. Antibiotics that suppress colonization of S. au...

Rapid detection and differentiation of Staphylococcus colonies using an optical scattering technology.

PubMed

Alsulami, Tawfiq S; Zhu, Xingyue; Abdelhaseib, Maha Usama; Singh, Atul K; Bhunia, Arun K

2018-05-24

Staphylococcus species are a major pathogen responsible for nosocomial infections and foodborne illnesses. We applied a laser-based BARDOT (bacterial rapid detection using optical scattering technology) for rapid colony screening and detection of Staphylococcus on an agar plate and differentiate these from non-Staphylococcus spp. Among the six growth media tested, phenol red mannitol agar (PRMA) was found most suitable for building the Staphylococcus species scatter image libraries. Scatter image library for Staphylococcus species gave a high positive predictive value (PPV 87.5-100%) when tested against known laboratory strains of Staphylococcus spp., while the PPV against non-Staphylococcus spp. was 0-38%. A total of nine naturally contaminated bovine raw milk and ready-to-eat chicken salad samples were tested, and BARDOT detected Staphylococcus including Staphylococcus aureus with 80-100% PPV. Forty-five BARDOT-identified bacterial isolates from naturally contaminated foods were further confirmed by tuf and nuc gene-specific PCR and 16S rRNA gene sequence. This label-free, non-invasive on-plate colony screening technology can be adopted by the food industries, biotechnology companies, and public health laboratories for Staphylococcus species detection including S. aureus from various samples for food safety and public health management. Graphical abstract.

Staphylococcus aureus healthcare associated bacteraemia: An indicator of catheter related infections.

PubMed

Bonnal, C; Birgand, G; Lolom, I; Diamantis, S; Dumortier, C; L'Heriteau, F; Armand-Lefevre, L; Lucet, J C

2015-03-01

Surveillance of preventable healthcare associated infections and feedback of the results to clinicians is central in the efforts to improve performance. We assessed Staphylococcus aureus healthcare associated bloodstream infection (HA-BSI) as an indicator of healthcare quality. Between 2002 and 2012, we carried out a ten-year prospective bedside surveillance of S. aureus healthcare associated bacteraemia in a 940-bed university hospital using standard definitions. Overall, 2784 HA-BSI were identified during the study period, among which 573 (18%) were due to S. aureus. Among these 573 S. aureus bacteraemias, 189 originated from intravascular catheters (32.8%) of which 84% (158/189) in patients outside intensive care units. The proportion of catheter related HA-BSI due to S. aureus was 56% (61/109) in PVC-related HA-BSI and 34% (103/301) in CVC-related HA-BSI. A sharp decrease of PVC-related HA-BSI from 20 to 7 per year was obtained during the same period. In our experience, S. aureus HA-BSI is a simple and useful indicator of catheter associated infections, and therefore of healthcare quality, especially in units not covered by other type of surveillance. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Molecular Characterization of Methicillin-Resistant Staphylococcus aureus Causing Fatal Purulent Pericarditis.

PubMed

Kumar, Vasudevan Anil; Nair, Nisha; Thachathodiyl, Rajesh; Nandakumar, Aswathy; Dinesh, Kavitha R; Thatcher, Eileen; Karim, Shamsul; Biswas, Raja

2013-07-01

Though pericardial disease is common in patients with renal disease, purulent pericarditis is very rare. We report a fatal case of purulent pericarditis and sepsis due to methicillin-resistant Staphylococcus aureus in a 78-year-old male with systemic hypertension and renal disease along with the molecular characterization of its resistant mechanism.

Antibacterial activity of four mouthrinses containing triclosan against salivary Staphylococcus aureus.

PubMed

Tanomaru, Juliane Maria Guerreiro; Nascimento, Andresa Piacezzi; Watanabe, Evandro; Matoba-Júnior, Fumio; Tanomaru-Filho, Mário; Ito, Izabel Yoko

2008-07-01

The maximum inhibitory dilution (MID) of triclosan-based mouthwashes against 28 Staphylococcus aureus strains was evaluated. Dilutions ranging from 1/10 to 1/655,360 were prepared. Strains were inoculated using a Steers multipoint inoculator. The MID was considered as the maximum dilution capable of inhibiting microorganism growth. The mouthwashes presented different MIDs.

mecC-Harboring Methicillin-Resistant Staphylococcus aureus: Hiding in Plain Sight.

PubMed

Ford, Bradley A

2018-01-01

Previously there was scant data on the performance of laboratory testing to detect mecC -mediated beta-lactam resistance in Staphylococcus aureus Kriegeskorte and colleagues (J Clin Microbiol 56:e00826-17, 2018, https://doi.org/10.1128/JCM.00826-17) report the performance of various clinical tests for the detection of mecC -harboring methicillin-resistant S. aureus (MRSA), which failed to identify from 0 to 41% of tested mecC -harboring MRSA isolates. Changes in practice and new test development are necessary to address the challenge of mecC -harboring MRSA. Copyright © 2017 American Society for Microbiology.

Prevalence and characterization of Methicillin-resistant Staphylococcus aureus isolates from retail meat and humans in Georgia

USDA-ARS?s Scientific Manuscript database

There is increasing interest in the presence of Staphylococcus aureus, specifically methicillin-resistant S. aureus (MRSA), on retail meat products. In this study, staphylococci were isolated from retail pork and retail beef in Georgia and MRSA from the products were compared to human MRSA from the...

Methicillin-resistant food-related Staphylococcus aureus: a review of current knowledge and biofilm formation for future studies and applications.

PubMed

Doulgeraki, Agapi I; Di Ciccio, Pierluigi; Ianieri, Adriana; Nychas, George-John E

2017-01-01

There is increasing concern about the public health impact of methicillin-resistant Staphylococcus aureus. Food and animal are vectors of transmission, but the contribution of a contaminated environment is not well characterized. With regard to this, staphylococcal biofilms serve as a virulence factor, allowing MRSA strains to adhere to surfaces and other materials used in the food industry. Methicillin resistance and biofilm-forming capacity may contribute to the success of S. aureus as a human pathogen in both health care and community settings and the food production chain. This review summarizes current knowledge about the significance of food- and animal-derived MRSA strains and provides data on attachment and biofilm formation of MRSA. In addition, the impact of quorum sensing on MRSA gene expression and biofilm formation is examined. Copyright © 2016. Published by Elsevier Masson SAS.

Genetic characterization and antimicrobial resistance of Staphylococcus aureus isolated from bovine milk in Tunisia.

PubMed

Ben Said, M; Abbassi, M S; Bianchini, V; Sghaier, S; Cremonesi, P; Romanò, A; Gualdi, V; Hassen, A; Luini, M V

2016-12-01

Staphylococcus aureus is a major agent of bovine mastitis in dairy herds, causing economic losses in dairy industry worldwide. In addition, milk and milk-products contaminated by Staph. aureus can cause harmful human diseases. The aim of this study was to characterize Staph. aureus strains isolated from dairy farms in Tunisia. Bulk tank milk (n = 32) and individual cow milk (n = 130) samples were collected during the period of 2013-2014. Forty-three Staph. aureus isolates were recovered and typed by spa typing, 16S-23S rRNA intergenic spacer (RS-PCR) and multiplex PCRs for 22 virulence genes. Antimicrobial resistance was also investigated with a disc diffusion test. A selected subsample of 22 strains was additionally genotyped by multilocus sequence typing. Seventeen spa types were recovered, and t2421 (n = 10), t521 (n = 6) and t2112 (n = 5) were the most common. Fourteen different RS-PCR genotypes grouped into 11 clusters were detected in our study, with predominance of the R VI genotype (n = 24). Eight sequence types were identified and Clonal Complex 97, corresponding to RS-PCR cluster R, was the most common (n = 10), followed by CC1 (n = 4), CC15 (n = 3) and other four accounting for one or two strains. Different combinations of virulence genes were reported, and enterotoxin genes were present in few strains (seh, n = 4; sea, n = 2; sea and seh, n = 2; sec and sel, n = 2). The majority of strains were resistant only to penicillin; only one strain was found to be multiresistant and no methicillin-resistant Staph. aureus was demonstrated. Our study reported the isolation of CC97 from bovine milk in Tunisia for the first time and confirmed the relevance of this lineage in intramammary infection in cows. This paper describes the characteristics of Staphylococcus aureus isolated from bulk tank and individual cow milk in Tunisia. All strains were genotyped by spa typing and RS-PCR, a method based on the amplification of the 16S-23S r

Back to the Future: Penicillin-Susceptible Staphylococcus aureus.

PubMed

Cheng, Matthew P; René, Pierre; Cheng, Alexandre P; Lee, Todd C

2016-12-01

Widespread penicillin usage rapidly resulted in the emergence of penicillin resistance in Staphylococcus aureus. However, new data suggest that penicillin susceptibility may be in a period of renaissance. The objective of our study was to quantify penicillin resistance in methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia. We retrospectively reviewed all adult MSSA bacteremia from April 2010 to April 2015 at the McGill University Health Centre (Montreal, QC, Canada). Susceptibility to penicillin, erythromycin, clindamycin, and trimethoprim-sulfamethoxazole (TMP-SMX) was determined in accordance with the Clinical & Laboratory Standards Institute guidelines. There were 324 unique episodes of MSSA bacteremia. Ninety (28%) isolates were susceptible to penicillin, 229 (71%) to erythromycin, 239 (74%) to clindamycin, and 317 (98%) to TMP-SMX. Isolates that were penicillin resistant were more likely to also be resistant to other antibiotics, but a statistically significant association was apparent only for erythromycin resistance (76/234, 32.2% vs 19/90, 21.1%, P = .04). The median age of patients was 67.5 years (interquartile range 52-78) and overall in-hospital 30-day mortality was 16.3% (53 deaths). After adjustment for patient age, there was no association between penicillin resistance and either intensive care unit admission or death. More than one-quarter of patients with MSSA bacteremia potentially could be treated with parenteral penicillin, which may offer pharmacokinetic advantages over other beta-lactam drugs and potentially improved outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

Protein A Suppresses Immune Responses during Staphylococcus aureus Bloodstream Infection in Guinea Pigs

PubMed Central

Kim, Hwan Keun; Falugi, Fabiana; Thomer, Lena; Missiakas, Dominique M.

2015-01-01

ABSTRACT   Staphylococcus aureus infection is not associated with the development of protective immunity, and disease relapses occur frequently. We hypothesize that protein A, a factor that binds immunoglobulin Fcγ and cross-links VH3 clan B cell receptors (IgM), is the staphylococcal determinant for host immune suppression. To test this, vertebrate IgM was examined for protein A cross-linking. High VH3 binding activity occurred with human and guinea immunoglobulin, whereas mouse and rabbit immunoglobulins displayed little and no binding, respectively. Establishing a guinea pig model of S. aureus bloodstream infection, we show that protein A functions as a virulence determinant and suppresses host B cell responses. Immunization with SpAKKAA, which cannot bind immunoglobulin, elicits neutralizing antibodies that enable guinea pigs to develop protective immunity. Importance  Staphylococcus aureus is the leading cause of soft tissue and bloodstream infections; however, a vaccine with clinical efficacy is not available. Using mice to model staphylococcal infection, earlier work identified protective antigens; however, corresponding human clinical trials did not reach their endpoints. We show that B cell receptor (IgM) cross-linking by protein A is an important immune evasion strategy of S. aureus that can be monitored in a guinea pig model of bloodstream infection. Further, immunization with nontoxigenic protein A enables infected guinea pigs to elicit antibody responses that are protective against S. aureus. Thus, the guinea pig model may support preclinical development of staphylococcal vaccines. PMID:25564466

Biofilm Formation of Staphylococcus aureus on Various Surfaces and Their Resistance to Chlorine Sanitizer.

PubMed

Lee, Jung-Su; Bae, Young-Min; Lee, Sook-Young; Lee, Sun-Young

2015-10-01

This study investigated the effect of material types (polystyrene, polypropylene, glass, and stainless steel) and glucose addition on Staphylococcus aureus biofilm formation, and the relationship between biofilm formation measured by crystal violet (CV) staining and the number of biofilm cells determined by cell counts was studied. We also evaluated the efficacy of chlorine sanitizer on inhibiting various different types of S. aureus biofilms on the surface of stainless steel. Levels of biofilm formation of S. aureus were higher on hydrophilic surfaces (glass and stainless steel) than on hydrophobic surfaces (polypropylene and polystyrene). With the exception of biofilm formed on glass, the addition of glucose in broth significantly increased the biofilm formation of S. aureus on all surfaces and for all tested strains (P ≤ 0.05). The number of biofilm cells was not correlated with the biomass of the biofilms determined using the CV staining method. The efficacy of chlorine sanitizer against biofilm of S. aureus was not significantly different depending on types of biofilm (P > 0.05). Therefore, further studies are needed in order to determine an accurate method quantifying levels of bacterial biofilm and to evaluate the resistance of bacterial biofilm on the material surface. Biofilm formation of Staphylococcus aureus on the surface was different depending on the surface characteristics and S. aureus strains. There was low correlation between crystal violet staining method and viable counts technique for measuring levels of biofilm formation of S. aureus on the surfaces. These results could provide helpful information for finding and understanding the quantification method and resistance of bacterial biofilm on the surface. © 2015 Institute of Food Technologists®

Effect of temperature on antibacterial activity of lidocaine to Staphylococcus aureus and Pseudomonas aeruginosa.

PubMed

Taki, Y; Seki, K; Ikigai, H; Nishihara, S; Ueno, H; Murota, K; Masuda, S

1988-01-01

The effect of temperature on the antibacterial activity of lidocaine to Staphylococcus aureus and Pseudomonas aeruginosa was investigated in vitro. At 10 C at which S. aureus organisms do not grow and might be metabolically inactive, the antibacterial activity of lidocaine to S. aureus was not observed in a concentration of 1%, which was quite antibacterial to S. aureus at 37 C. On the other hand, at 40 C a conspicuously increased antibacterial activity to S. aureus of lidocaine was observed in a concentration of 0.25% which was not antibacterial to S. aureus organisms at 37 C. Similar results were obtained when P. aeruginosa organisms were examined in place of S. aureus, although P. aeruginosa was found to be less susceptible to lidocaine than S. aureus. The clinical significance of the thermal effect on the antibacterial activity of lidocaine was discussed in brief.

Staphylococcus aureus infections in Australasian neonatal nurseries.

PubMed

Isaacs, D; Fraser, S; Hogg, G; Li, H Y

2004-07-01

To study the incidence and outcome of systemic infections with methicillin sensitive (MSSA) and methicillin resistant Staphylococcus aureus (MRSA) infections in Australasian neonatal nurseries. Prospective longitudinal study of systemic infections (clinical sepsis plus positive cultures of blood and/or cerebrospinal fluid) in 17 Australasian neonatal nurseries. The incidence of early onset sepsis with S aureus, mainly MSSA, was 19 cases per 244 718 live births or 0.08 per 1000. From 1992 to 1994, MRSA infections caused only 8% of staphylococcal infections. From 1995 to 1998, there was an outbreak of MRSA infection, in two Melbourne hospitals. The outbreak resolved, after the use of topical mupirocin and improved handwashing. Babies with MRSA sepsis were significantly smaller than babies with MSSA sepsis (mean birth weight 1093 v 1617 g) and more preterm (mean gestation 27.5 v 30.3 weeks). The mortality of MRSA sepsis was 24.6% compared with 9.9% for MSSA infections. The mortality of early onset MSSA sepsis, however, was 39% (seven of 18) compared with 7.3% of late onset MSSA infection presenting more than two days after birth. S aureus is a rare but important cause of early onset sepsis. Late onset MRSA infections carried a higher mortality than late onset MSSA infections, but babies with early onset MSSA sepsis had a particularly high mortality.

A Single-Stranded DNA Aptamer That Selectively Binds to Staphylococcus aureus Enterotoxin B

PubMed Central

DeGrasse, Jeffrey A.

2012-01-01

The bacterium Staphylococcus aureus is a common foodborne pathogen capable of secreting a cocktail of small, stable, and strain-specific, staphylococcal enterotoxins (SEs). Staphylococcal food poisoning (SFP) results when improperly handled food contaminated with SEs is consumed. Gastrointestinal symptoms of SFP include emesis, diarrhea and severe abdominal pain, which manifest within hours of ingesting contaminated food. Immuno-affinity based methods directly detect, identify, and quantify several SEs within a food or clinical sample. However, the success of these assays depends upon the availability of a monoclonal antibody, the development of which is non-trivial and costly. The current scope of the available immuno-affinity based methods is limited to the classical SEs and does not encompass all of the known or emergent SEs. In contrast to antibodies, aptamers are short nucleic acids that exhibit high affinity and specificity for their targets without the high-costs and ethical concerns of animal husbandry. Further, researchers may choose to freely distribute aptamers and develop assays without the proprietary issues that increase the per-sample cost of immuno-affinity assays. This study describes a novel aptamer, selected in vitro, with affinity to staphylococcal enterotoxin B (SEB) that may be used in lieu of antibodies in SE detection assays. The aptamer, designated APTSEB1, successfully isolates SEB from a complex mixture of SEs with extremely high discrimination. This work sets the foundation for future aptamer and assay development towards the entire family of SEs. The rapid, robust, and low-cost identification and quantification of all of the SEs in S. aureus contaminated food is essential for food safety and epidemiological efforts. An in vitro generated library of SE aptamers could potentially allow for the comprehensive and cost-effective analysis of food samples that immuno-affinity assays currently cannot provide. PMID:22438927

A single-stranded DNA aptamer that selectively binds to Staphylococcus aureus enterotoxin B.

PubMed

DeGrasse, Jeffrey A

2012-01-01

The bacterium Staphylococcus aureus is a common foodborne pathogen capable of secreting a cocktail of small, stable, and strain-specific, staphylococcal enterotoxins (SEs). Staphylococcal food poisoning (SFP) results when improperly handled food contaminated with SEs is consumed. Gastrointestinal symptoms of SFP include emesis, diarrhea and severe abdominal pain, which manifest within hours of ingesting contaminated food. Immuno-affinity based methods directly detect, identify, and quantify several SEs within a food or clinical sample. However, the success of these assays depends upon the availability of a monoclonal antibody, the development of which is non-trivial and costly. The current scope of the available immuno-affinity based methods is limited to the classical SEs and does not encompass all of the known or emergent SEs. In contrast to antibodies, aptamers are short nucleic acids that exhibit high affinity and specificity for their targets without the high-costs and ethical concerns of animal husbandry. Further, researchers may choose to freely distribute aptamers and develop assays without the proprietary issues that increase the per-sample cost of immuno-affinity assays. This study describes a novel aptamer, selected in vitro, with affinity to staphylococcal enterotoxin B (SEB) that may be used in lieu of antibodies in SE detection assays. The aptamer, designated APT(SEB1), successfully isolates SEB from a complex mixture of SEs with extremely high discrimination. This work sets the foundation for future aptamer and assay development towards the entire family of SEs. The rapid, robust, and low-cost identification and quantification of all of the SEs in S. aureus contaminated food is essential for food safety and epidemiological efforts. An in vitro generated library of SE aptamers could potentially allow for the comprehensive and cost-effective analysis of food samples that immuno-affinity assays currently cannot provide.

Detection of methicillin resistance and slime factor production of Staphylococcus aureus in bovine mastitis

PubMed Central

Ciftci, Alper; Findik, Arzu; Onuk, Ertan Emek; Savasan, Serap

2009-01-01

This study aimed to detect methicillin resistant and slime producing Staphylococcus aureus in cases of bovine mastitis. A triplex PCR was optimized targetting 16S rRNA, nuc and mecA genes for detection of Staphylococcus species, S. aureus and methicillin resistance, respectively. Furthermore, for detection of slime producing strains, a PCR assay targetting icaA and icaD genes was performed. In this study, 59 strains were detected as S. aureus by both conventional tests and PCR, and 13 of them were found to be methicillin resistant and 4 (30.7%) were positive for mecA gene. Although 22 of 59 (37.2%) S. aureus isolates were slime-producing in Congo Red Agar, in PCR analysis only 15 were positive for both icaA and icaD genes. Sixteen and 38 out of 59 strains were positive for icaA and icaD gene, respectively. Only 2 of 59 strains were positive for both methicillin resistance and slime producing, phenotypically, suggesting lack of correlation between methicillin resistance and slime production in these isolates. In conclusion, the optimized triplex PCR in this study was useful for rapid and reliable detection of methicillin resistant S. aureus. Furthermore, only PCR targetting icaA and icaD may not sufficient to detect slime production and further studies targetting other ica genes should be conducted for accurate evaluation of slime production characters of S. aureus strains. PMID:24031354

Methicillin-resistant Staphylococcus aureus--an overview.

PubMed

Eadon, H J; Pinney, R J

1991-12-01

Methicillin-resistant strains of Staphylococcus aureus (MRSA) cause life-threatening infections, but they are no more pathogenic than methicillin-sensitive strains. Difficulties occur because of incorrect or missed identification of MRSA, and hence inappropriate or ineffective treatment of infections. Therapeutic options are severely limited and the increasing spectrum of resistance in MRSA is worrying. However, new methods of detection and new agents for treatment are being developed in response to the challenge of MRSA. Whilst the organism is a problem and control measures are necessary to contain its spread, the outlook is not bleak. In the medium term, the development of new, effective anti-MRSA agents should prevent the threat of MRSA becoming any greater in the field of hospital infection control.

Antiinfective therapy with a small molecule inhibitor of Staphylococcus aureus sortase.

PubMed

Zhang, Jie; Liu, Hongchuan; Zhu, Kongkai; Gong, Shouzhe; Dramsi, Shaynoor; Wang, Ya-Ting; Li, Jiafei; Chen, Feifei; Zhang, Ruihan; Zhou, Lu; Lan, Lefu; Jiang, Hualiang; Schneewind, Olaf; Luo, Cheng; Yang, Cai-Guang

2014-09-16

Methicillin-resistant Staphylococcus aureus (MRSA) is the most frequent cause of hospital-acquired infection, which manifests as surgical site infections, bacteremia, and sepsis. Due to drug-resistance, prophylaxis of MRSA infection with antibiotics frequently fails or incites nosocomial diseases such as Clostridium difficile infection. Sortase A is a transpeptidase that anchors surface proteins in the envelope of S. aureus, and sortase mutants are unable to cause bacteremia or sepsis in mice. Here we used virtual screening and optimization of inhibitor structure to identify 3-(4-pyridinyl)-6-(2-sodiumsulfonatephenyl)[1,2,4]triazolo[3,4-b][1,3,4]thiadiazole and related compounds, which block sortase activity in vitro and in vivo. Sortase inhibitors do not affect in vitro staphylococcal growth yet protect mice against lethal S. aureus bacteremia. Thus, sortase inhibitors may be useful as antiinfective therapy to prevent hospital-acquired S. aureus infection in high-risk patients without the side effects of antibiotics.

Staphylococcus aureus secretes a unique class of neutrophil serine protease inhibitors

PubMed Central

Stapels, Daphne A. C.; Ramyar, Kasra X.; Bischoff, Markus; von Köckritz-Blickwede, Maren; Milder, Fin J.; Ruyken, Maartje; Eisenbeis, Janina; McWhorter, William J.; Herrmann, Mathias; van Kessel, Kok P. M.; Geisbrecht, Brian V.; Rooijakkers, Suzan H. M.

2014-01-01

Neutrophils are indispensable for clearing infections with the prominent human pathogen Staphylococcus aureus. Here, we report that S. aureus secretes a family of proteins that potently inhibits the activity of neutrophil serine proteases (NSPs): neutrophil elastase (NE), proteinase 3, and cathepsin G. The NSPs, but not related serine proteases, are specifically blocked by the extracellular adherence protein (Eap) and the functionally orphan Eap homologs EapH1 and EapH2, with inhibitory-constant values in the low-nanomolar range. Eap proteins are together essential for NSP inhibition by S. aureus in vitro and promote staphylococcal infection in vivo. The crystal structure of the EapH1/NE complex showed that Eap molecules constitute a unique class of noncovalent protease inhibitors that occlude the catalytic cleft of NSPs. These findings increase our insights into the complex pathogenesis of S. aureus infections and create opportunities to design novel treatment strategies for inflammatory conditions related to excessive NSP activity. PMID:25161283

New epidemiology of Staphylococcus aureus infection in Asia.

PubMed

Chen, C-J; Huang, Y-C

2014-07-01

Not only is Asia the most populous region in the world, but inappropriate therapy, including self-medication with over-the-counter antimicrobial agents, is a common response to infectious diseases. The high antibiotic selective pressure among the overcrowded inhabitants creates an environment that is suitable for the rapid development and efficient spread of numerous multidrug-resistant pathogens. Indeed, Asia is among the regions with the highest prevalence rates of healthcare-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) and community-associated methicillin-resistant S. aureus (CA-MRSA) in the world. Most hospitals in Asia are endemic for multidrug-resistant methicillin-resistant S. aureus (MRSA), with an estimated proportion from 28% (in Hong Kong and Indonesia) to >70% (in Korea) among all clinical S. aureus isolates in the early 2010s. Isolates with reduced susceptibility or a high level of resistance to glycopeptides have also been increasingly identified in the past few years. In contrast, the proportion of MRSA among community-associated S. aureus infections in Asian countries varies markedly, from <5% to >35%. Two pandemic HA-MRSA clones, namely multilocus sequence type (ST) 239 and ST5, are disseminated internationally in Asia, whereas the molecular epidemiology of CA-MRSA in Asia is characterized by clonal heterogeneity, similar to that in Europe. In this review, the epidemiology of S. aureus in both healthcare facilities and communities in Asia is addressed, with an emphasis on the prevalence, clonal structure and antibiotic resistant profiles of the MRSA strains. The novel MRSA strains from livestock animals have been considered to constitute a public health threat in western countries. The emerging livestock-associated MRSA strains in Asia are also included in this review. © 2014 The Authors Clinical Microbiology and Infection © 2014 European Society of Clinical Microbiology and Infectious Diseases.

Growth and adherence of Staphylococcus aureus were enhanced through the PGE2 produced by the activated COX-2/PGE2 pathway of infected oral epithelial cells

PubMed Central

Wang, Yuxia; Ren, Biao; Zhou, Xuedong; Liu, Shiyu; Zhou, Yujie; Li, Bolei; Jiang, Yaling; Li, Mingyun; Feng, Mingye

2017-01-01

Staphylococcus aureus is a major pathogen of varieties of oral mucous infection. Prostaglandin E2 (PGE2) is a pro-inflammatory factor and Cyclooxygenase 2 (COX-2) is a critical enzyme of PGE2 biosynthesis. The purpose of this study is to investigate whether Staphylococcus aureus can increase PGE2 production of oral epithelial cells and how PGE2 functions in the growth and adherence of Staphylococcus aureus. mRNA levels of COX-2, fnbpA and fnbpB were estimated by quantitative PCR. PGE2 production was measured by Enzyme Linked Immunosorbent Assay (ELISA). The binding biomass of Staphylococcus aureus to human fibronectin was investigated by crystal violet staining and confocal laser scanning microscopy and the adherent force was measured by atomic force microscope (AFM). The COX-2 mRNA level and PGE2 production were increased by Staphylococcus aureus. PGE2 promoted the growth and biofilm formation of Staphylococcus aureus, enhanced the attachment of Staphylococcus aureus to the human fibronectin as well as to the HOK cells. The transcription of fnbpB was up-regulated by PGE2 in both early and middle exponential phase but not fnbpA. These results suggest that the activation of COX-2/PGE2 pathway in oral epithelial cell by Staphylococcus aureus can in turn facilitate the growth and the ability to adhere of the pathogen. These findings uncover a new function of PGE2 and may lead to the potential of COX-2/PGE2 targeting in the therapy of inflammation and cancer in both which the COX-2/PGE2 pathway were observed activated. PMID:28472126

Growth and adherence of Staphylococcus aureus were enhanced through the PGE2 produced by the activated COX-2/PGE2 pathway of infected oral epithelial cells.

PubMed

Wang, Yuxia; Ren, Biao; Zhou, Xuedong; Liu, Shiyu; Zhou, Yujie; Li, Bolei; Jiang, Yaling; Li, Mingyun; Feng, Mingye; Cheng, Lei

2017-01-01

Staphylococcus aureus is a major pathogen of varieties of oral mucous infection. Prostaglandin E2 (PGE2) is a pro-inflammatory factor and Cyclooxygenase 2 (COX-2) is a critical enzyme of PGE2 biosynthesis. The purpose of this study is to investigate whether Staphylococcus aureus can increase PGE2 production of oral epithelial cells and how PGE2 functions in the growth and adherence of Staphylococcus aureus. mRNA levels of COX-2, fnbpA and fnbpB were estimated by quantitative PCR. PGE2 production was measured by Enzyme Linked Immunosorbent Assay (ELISA). The binding biomass of Staphylococcus aureus to human fibronectin was investigated by crystal violet staining and confocal laser scanning microscopy and the adherent force was measured by atomic force microscope (AFM). The COX-2 mRNA level and PGE2 production were increased by Staphylococcus aureus. PGE2 promoted the growth and biofilm formation of Staphylococcus aureus, enhanced the attachment of Staphylococcus aureus to the human fibronectin as well as to the HOK cells. The transcription of fnbpB was up-regulated by PGE2 in both early and middle exponential phase but not fnbpA. These results suggest that the activation of COX-2/PGE2 pathway in oral epithelial cell by Staphylococcus aureus can in turn facilitate the growth and the ability to adhere of the pathogen. These findings uncover a new function of PGE2 and may lead to the potential of COX-2/PGE2 targeting in the therapy of inflammation and cancer in both which the COX-2/PGE2 pathway were observed activated.

Antimicrobial Mechanisms of Macrophages and the Immune Evasion Strategies of Staphylococcus aureus

PubMed Central

Flannagan, Ronald S.; Heit, Bryan; Heinrichs, David E.

2015-01-01

Habitually professional phagocytes, including macrophages, eradicate microbial invaders from the human body without overt signs of infection. Despite this, there exist select bacteria that are professional pathogens, causing significant morbidity and mortality across the globe and Staphylococcus aureus is no exception. S. aureus is a highly successful pathogen that can infect virtually every tissue that comprises the human body causing a broad spectrum of diseases. The profound pathogenic capacity of S. aureus can be attributed, in part, to its ability to elaborate a profusion of bacterial effectors that circumvent host immunity. Macrophages are important professional phagocytes that contribute to both the innate and adaptive immune response, however from in vitro and in vivo studies, it is evident that they fail to eradicate S. aureus. This review provides an overview of the antimicrobial mechanisms employed by macrophages to combat bacteria and describes the immune evasion strategies and some representative effectors that enable S. aureus to evade macrophage-mediated killing. PMID:26633519

Eradication of methicillin-resistant Staphylococcus aureus and of Enterobacteriaceae expressing extended-spectrum beta-lactamases on a model pig farm.

PubMed

Schmithausen, Ricarda Maria; Kellner, Sophia Ricarda; Schulze-Geisthoevel, Sophia Veronika; Hack, Sylvia; Engelhart, Steffen; Bodenstein, Isabel; Al-Sabti, Nahed; Reif, Marion; Fimmers, Rolf; Körber-Irrgang, Barbara; Harlizius, Jürgen; Hoerauf, Achim; Exner, Martin; Bierbaum, Gabriele; Petersen, Brigitte; Bekeredjian-Ding, Isabelle

2015-11-01

Colonization of livestock with bacteria resistant to antibiotics is considered a risk for the entry of drug-resistant pathogens into the food chain. For this reason, there is a need for novel concepts to address the eradication of drug-resistant commensals on farms. In the present report, we evaluated the decontamination measures taken on a farm contaminated with methicillin-resistant Staphylococcus aureus (MRSA) and Enterobacteriaceae expressing extended-spectrum β-lactamases (ESBL-E). The decontamination process preceded the conversion from piglet breeding to gilt production. Microbiological surveillance showed that the decontamination measures eliminated the MRSA and ESBL-E strains that were detected on the farm before the complete removal of pigs, cleaning and disinfection of the stable, and construction of an additional stable meeting high-quality standards. After pig production was restarted, ESBL-E remained undetectable over 12 months, but MRSA was recovered from pigs and the environment within the first 2 days. However, spa (Staphylococcus aureus protein A gene) typing revealed acquisition of an MRSA strain (type t034) that had not been detected before decontamination. Interestingly, we observed that a farmworker who had been colonized with the prior MRSA strain (t2011) acquired the new strain (t034) after 2 months. In summary, this report demonstrates that decontamination protocols similar to those used here can lead to successful elimination of contaminating MRSA and ESBL-E in pigs and the stable environment. Nevertheless, decontamination protocols do not prevent the acquisition of new MRSA strains. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Staphylococcus aureus from the German general population is highly diverse.

PubMed

Becker, Karsten; Schaumburg, Frieder; Fegeler, Christian; Friedrich, Alexander W; Köck, Robin

2017-01-01

This prospective cohort study evaluates colonization dynamics and molecular characteristics of methicillin-susceptible and - resistant Staphylococcus aureus (MSSA/MRSA) in a German general population. Nasal swabs of 1878 non-hospitalized adults were screened for S. aureus. Participants were screened thrice in intervals of 6-8 months. Isolates were characterized by spa and agr typing, mecA and mecC possession, respectively, and PCRs targeting virulence factors. 40.9% of all participants carried S. aureus at least once while 0.7% of the participants carried MRSA (mainly spa t011). MSSA isolates (n=1359) were associated with 331 different spa types; t084 (7.7%), t091 (6.1%) and t012 (71, 5.2%) were predominant. Of 206 participants carrying S. aureus at all three sampling time points, 14.1% carried the same spa type continuously; 5.3% carried different spa types with similar repeat patterns, but 80.6% carried S. aureus with unrelated spa types. MSSA isolates frequently harboured genes encoding enterotoxins (sec: 16.6%, seg: 63.1%, sei: 64.5%) and toxic shock syndrome toxin (tst: 17.5%), but rarely Panton-Valentine leukocidin (lukS-PV/lukF-PV: 0.2%). MSSA colonizing human nares in the community are clonally highly diverse. Among those constantly carrying S. aureus, clonal lineages changed over time. The proportion of persistent S. aureus carriers was lower than reported elsewhere. Copyright © 2016 Elsevier GmbH. All rights reserved.

Antibacterial activity of four mouthrinses containing triclosan against salivary Staphylococcus aureus

PubMed Central

Tanomaru, Juliane Maria Guerreiro; Nascimento, Andresa Piacezzi; Watanabe, Evandro; Matoba-Júnior, Fumio; Tanomaru-Filho, Mário; Ito, Izabel Yoko

2008-01-01

The maximum inhibitory dilution (MID) of triclosan-based mouthwashes against 28 Staphylococcus aureus strains was evaluated. Dilutions ranging from 1/10 to 1/655,360 were prepared. Strains were inoculated using a Steers multipoint inoculator. The MID was considered as the maximum dilution capable of inhibiting microorganism growth. The mouthwashes presented different MIDs. PMID:24031267

Cryomilled zinc sulfide: A prophylactic for Staphylococcus aureus-infected wounds

DOE PAGES

Tran, Phat L.; Li, Jianqiang; Lungaro, Lisa; ...

2018-04-23

Bacterial pathogens that colonize wounds form biofilms, which protect the bacteria from the effect of host immune response and antibiotics. This paper examined the effectiveness of newly synthesized zinc sulfide in inhibiting biofilm development by Staphylococcus aureus (S. aureus) strains. Zinc sulfide (ZnS) was anaerobically biosynthesized to produce CompA, which was further processed by cryomilling to maximize the antibacterial properties to produce CompB. The effect of the two compounds on the S. aureus strain AH133 was compared using zone of inhibition assay. The compounds were formulated in a polyethylene glycol cream. We compared the effect of the two compounds onmore » biofilm development by AH133 and two methicillin-resistant S. aureus clinical isolates using the in vitro model of wound infection. Zone of inhibition assay revealed that CompB is more effective than CompA. At 15 mg/application, the formulated cream of either compound inhibited biofilm development by AH133, which was confirmed using confocal laser scanning microscopy. At 20 mg/application, CompB inhibited biofilm development by the two methicillin-resistant S. aureus clinical isolates. To further validate the effectiveness of CompB, mice were treated using the murine model of wound infection. Finally, colony forming cell assay and in vivo live imaging results strongly suggested the inhibition of S. aureus growth.« less

Cryomilled zinc sulfide: A prophylactic for Staphylococcus aureus-infected wounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tran, Phat L.; Li, Jianqiang; Lungaro, Lisa

Bacterial pathogens that colonize wounds form biofilms, which protect the bacteria from the effect of host immune response and antibiotics. This paper examined the effectiveness of newly synthesized zinc sulfide in inhibiting biofilm development by Staphylococcus aureus (S. aureus) strains. Zinc sulfide (ZnS) was anaerobically biosynthesized to produce CompA, which was further processed by cryomilling to maximize the antibacterial properties to produce CompB. The effect of the two compounds on the S. aureus strain AH133 was compared using zone of inhibition assay. The compounds were formulated in a polyethylene glycol cream. We compared the effect of the two compounds onmore » biofilm development by AH133 and two methicillin-resistant S. aureus clinical isolates using the in vitro model of wound infection. Zone of inhibition assay revealed that CompB is more effective than CompA. At 15 mg/application, the formulated cream of either compound inhibited biofilm development by AH133, which was confirmed using confocal laser scanning microscopy. At 20 mg/application, CompB inhibited biofilm development by the two methicillin-resistant S. aureus clinical isolates. To further validate the effectiveness of CompB, mice were treated using the murine model of wound infection. Finally, colony forming cell assay and in vivo live imaging results strongly suggested the inhibition of S. aureus growth.« less

Diversity of Staphylococcus aureus strains colonizing various niches of the human body.

PubMed

Muenks, Carol E; Hogan, Patrick G; Wang, Jeffrey W; Eisenstein, Kimberly A; Burnham, Carey-Ann D; Fritz, Stephanie A

2016-06-01

As individuals may be colonized with multiple strains of Staphylococcus aureus at different body sites, the objectives of this study were to determine whether S. aureus polyclonal colonization exists within one body niche and the optimal sampling sites and culture methodology to capture the diversity of S. aureus strains in community-dwelling individuals. Swabs were collected from the nares, axillae, and inguinal folds of 3 children with community-associated S. aureus infections and 11 household contacts, all with known S. aureus colonization. S. aureus isolates were recovered from each body niche using 4 culture methods and evaluated for polyclonality using phenotypic and genotypic strain characterization methodologies. Within individuals, the mean (range) number of phenotypes and genotypes was 2.4 (1-4) and 3.1 (1-6), respectively. Six (43%) and 10 (71%) participants exhibited phenotypic and genotypic polyclonality within one body niche, respectively. Broth enrichment yielded the highest analytical sensitivity for S. aureus recovery, while direct plating to blood agar yielded the highest genotypic strain diversity. This study revealed S. aureus polyclonality within a single body niche. Culture methodology and sampling sites influenced the analytical sensitivity of S. aureus colonization detection and the robustness of phenotypic and genotypic strain recovery. Copyright © 2016 The British Infection Association. Published by Elsevier Ltd. All rights reserved.