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Sample records for aeruginosa environmental isolate

  1. Pseudomonas aeruginosa clinical and environmental isolates constitute a single population with high phenotypic diversity

    PubMed Central

    2014-01-01

    Background Pseudomonas aeruginosa is an opportunistic pathogen with a high incidence of hospital infections that represents a threat to immune compromised patients. Genomic studies have shown that, in contrast to other pathogenic bacteria, clinical and environmental isolates do not show particular genomic differences. In addition, genetic variability of all the P. aeruginosa strains whose genomes have been sequenced is extremely low. This low genomic variability might be explained if clinical strains constitute a subpopulation of this bacterial species present in environments that are close to human populations, which preferentially produce virulence associated traits. Results In this work, we sequenced the genomes and performed phenotypic descriptions for four non-human P. aeruginosa isolates collected from a plant, the ocean, a water-spring, and from dolphin stomach. We show that the four strains are phenotypically diverse and that this is not reflected in genomic variability, since their genomes are almost identical. Furthermore, we performed a detailed comparative genomic analysis of the four strains studied in this work with the thirteen previously reported P. aeruginosa genomes by means of describing their core and pan-genomes. Conclusions Contrary to what has been described for other bacteria we have found that the P. aeruginosa core genome is constituted by a high proportion of genes and that its pan-genome is thus relatively small. Considering the high degree of genomic conservation between isolates of P. aeruginosa from diverse environments, including human tissues, some implications for the treatment of infections are discussed. This work also represents a methodological contribution for the genomic study of P. aeruginosa, since we provide a database of the comparison of all the proteins encoded by the seventeen strains analyzed. PMID:24773920

  2. Pseudomonas aeruginosa in Dairy Goats: Genotypic and Phenotypic Comparison of Intramammary and Environmental Isolates

    PubMed Central

    Scaccabarozzi, Licia; Leoni, Livia; Ballarini, Annalisa; Barberio, Antonio; Locatelli, Clara; Casula, Antonio; Bronzo, Valerio; Pisoni, Giuliano; Jousson, Olivier; Morandi, Stefano; Rapetti, Luca; García-Fernández, Aurora; Moroni, Paolo

    2015-01-01

    Following the identification of a case of severe clinical mastitis in a Saanen dairy goat (goat A), an average of 26 lactating goats in the herd was monitored over a period of 11 months. Milk microbiological analysis revealed the presence of Pseudomonas aeruginosa in 7 of the goats. Among these 7 does, only goat A showed clinical signs of mastitis. The 7 P. aeruginosa isolates from the goat milk and 26 P. aeruginosa isolates from environmental samples were clustered by RAPD-PCR and PFGE analyses in 3 genotypes (G1, G2, G3) and 4 clusters (A, B, C, D), respectively. PFGE clusters A and B correlated with the G1 genotype and included the 7 milk isolates. Although it was not possible to identify the infection source, these results strongly suggest a spreading of the infection from goat A. Clusters C and D overlapped with genotypes G2 and G3, respectively, and included only environmental isolates. The outcome of the antimicrobial susceptibility test performed on the isolates revealed 2 main patterns of multiple resistance to beta-lactam antibiotics and macrolides. Virulence related phenotypes were analyzed, such as swarming and swimming motility, production of biofilm and production of secreted virulence factors. The isolates had distinct phenotypic profiles, corresponding to genotypes G1, G2 and G3. Overall, correlation analysis showed a strong correlation between sampling source, RAPD genotype, PFGE clusters, and phenotypic clusters. The comparison of the levels of virulence related phenotypes did not indicate a higher pathogenic potential in the milk isolates as compared to the environmental isolates. PMID:26606430

  3. Environmental Pseudomonads Inhibit Cystic Fibrosis Patient-Derived Pseudomonas aeruginosa.

    PubMed

    Chatterjee, Payel; Davis, Elizabeth; Yu, Fengan; James, Sarah; Wildschutte, Julia H; Wiegmann, Daniel D; Sherman, David H; McKay, Robert M; LiPuma, John J; Wildschutte, Hans

    2017-01-15

    Pseudomonas aeruginosa is an opportunistic pathogen which is evolving resistance to many currently used antibiotics. While much research has been devoted to the roles of pathogenic P. aeruginosa in cystic fibrosis (CF) patients, less is known of its ecological properties. P. aeruginosa dominates the lungs during chronic infection in CF patients, yet its abundance in some environments is less than that of other diverse groups of pseudomonads. Here, we sought to determine if clinical isolates of P. aeruginosa are vulnerable to environmental pseudomonads that dominate soil and water habitats in one-to-one competitions which may provide a source of inhibitory factors. We isolated a total of 330 pseudomonads from diverse habitats of soil and freshwater ecosystems and competed these strains against one another to determine their capacity for antagonistic activity. Over 900 individual inhibitory events were observed. Extending the analysis to P. aeruginosa isolates revealed that clinical isolates, including ones with increased alginate production, were susceptible to competition by multiple environmental strains. We performed transposon mutagenesis on one isolate and identified an ∼14.8-kb locus involved in antagonistic activity. Only two other environmental isolates were observed to carry the locus, suggesting the presence of additional unique compounds or interactions among other isolates involved in outcompeting P. aeruginosa This collection of strains represents a source of compounds that are active against multiple pathogenic strains. With the evolution of resistance of P. aeruginosa to currently used antibiotics, these environmental strains provide opportunities for novel compound discovery against drug-resistant clinical strains.

  4. Whole genome and transcriptome analyses of environmental antibiotic sensitive and multi-resistant Pseudomonas aeruginosa isolates exposed to waste water and tap water.

    PubMed

    Schwartz, Thomas; Armant, Olivier; Bretschneider, Nancy; Hahn, Alexander; Kirchen, Silke; Seifert, Martin; Dötsch, Andreas

    2015-01-01

    The fitness of sensitive and resistant Pseudomonas aeruginosa in different aquatic environments depends on genetic capacities and transcriptional regulation. Therefore, an antibiotic-sensitive isolate PA30 and a multi-resistant isolate PA49 originating from waste waters were compared via whole genome and transcriptome Illumina sequencing after exposure to municipal waste water and tap water. A number of different genomic islands (e.g. PAGIs, PAPIs) were identified in the two environmental isolates beside the highly conserved core genome. Exposure to tap water and waste water exhibited similar transcriptional impacts on several gene clusters (antibiotic and metal resistance, genetic mobile elements, efflux pumps) in both environmental P. aeruginosa isolates. The MexCD-OprJ efflux pump was overexpressed in PA49 in response to waste water. The expression of resistance genes, genetic mobile elements in PA49 was independent from the water matrix. Consistently, the antibiotic sensitive strain PA30 did not show any difference in expression of the intrinsic resistance determinants and genetic mobile elements. Thus, the exposure of both isolates to polluted waste water and oligotrophic tap water resulted in similar expression profiles of mentioned genes. However, changes in environmental milieus resulted in rather unspecific transcriptional responses than selected and stimuli-specific gene regulation.

  5. Environmental Pseudomonads Inhibit Cystic Fibrosis Patient-Derived Pseudomonas aeruginosa

    PubMed Central

    Chatterjee, Payel; Davis, Elizabeth; Yu, Fengan; James, Sarah; Wildschutte, Julia H.; Wiegmann, Daniel D.; Sherman, David H.; McKay, Robert M.; LiPuma, John J.

    2016-01-01

    ABSTRACT Pseudomonas aeruginosa is an opportunistic pathogen which is evolving resistance to many currently used antibiotics. While much research has been devoted to the roles of pathogenic P. aeruginosa in cystic fibrosis (CF) patients, less is known of its ecological properties. P. aeruginosa dominates the lungs during chronic infection in CF patients, yet its abundance in some environments is less than that of other diverse groups of pseudomonads. Here, we sought to determine if clinical isolates of P. aeruginosa are vulnerable to environmental pseudomonads that dominate soil and water habitats in one-to-one competitions which may provide a source of inhibitory factors. We isolated a total of 330 pseudomonads from diverse habitats of soil and freshwater ecosystems and competed these strains against one another to determine their capacity for antagonistic activity. Over 900 individual inhibitory events were observed. Extending the analysis to P. aeruginosa isolates revealed that clinical isolates, including ones with increased alginate production, were susceptible to competition by multiple environmental strains. We performed transposon mutagenesis on one isolate and identified an ∼14.8-kb locus involved in antagonistic activity. Only two other environmental isolates were observed to carry the locus, suggesting the presence of additional unique compounds or interactions among other isolates involved in outcompeting P. aeruginosa. This collection of strains represents a source of compounds that are active against multiple pathogenic strains. With the evolution of resistance of P. aeruginosa to currently used antibiotics, these environmental strains provide opportunities for novel compound discovery against drug-resistant clinical strains. IMPORTANCE We demonstrate that clinical CF-derived isolates of P. aeruginosa are susceptible to competition in the presence of environmental pseudomonads. We observed that many diverse environmental strains exhibited varied

  6. Isolation of oxidase-negative Pseudomonas aeruginosa from sputum culture.

    PubMed

    Hampton, K D; Wasilauskas, B L

    1979-05-01

    Two isolates of Pseudomonas aeruginosa lacking characteristic indophenol oxidase were recovered from a sputum specimen. A discussion of the characteristic biochemical tests and antibiograms along with a possible explanation for this phenomenon is presented.

  7. Comparative analysis of the volatile metabolomes of Pseudomonas aeruginosa clinical isolates.

    PubMed

    Bean, Heather D; Rees, Christiaan A; Hill, Jane E

    2016-11-21

    Pseudomonas aeruginosa is a nearly ubiquitous Gram-negative organism, well known to occupy a multitude of environmental niches and cause human infections at a variety of bodily sites, due to its metabolic flexibility, secondary to extensive genetic heterogeneity at the species level. Because of its dynamic metabolism and clinical importance, we sought to perform a comparative analysis on the volatile metabolome (the 'volatilome') produced by P. aeruginosa clinical isolates. In this study, we analyzed the headspace volatile molecules of 24 P. aeruginosa clinical isolates grown in vitro, using 2D gas chromatography time-of-flight mass spectrometry (GC  ×  GC-TOFMS). We identified 391 non-redundant compounds that we associate with the growth and metabolism of P. aeruginosa (the 'pan-volatilome'). Of these, 70 were produced by all 24 isolates (the 'core volatilome'), 52 by only a single isolate, and the remaining 269 volatile molecules by a subset. Sixty-five of the detected compounds could be assigned putative compound identifications, of which 43 had not previously been associated with P. aeruginosa. Using the accessory volatile molecules, we determined the inter-strain variation in the metabolomes of these isolates, clustering strains by their metabotypes. Assessing the extent of metabolomic diversity in P. aeruginosa through an analysis of the volatile molecules that it produces is a critical next step in the identification of novel diagnostic or prognostic biomarkers.

  8. Pseudomonas aeruginosa isolates from dental unit waterlines can be divided in two distinct groups, including one displaying phenotypes similar to isolates from cystic fibrosis patients

    PubMed Central

    Ouellet, Myriam M.; Leduc, Annie; Nadeau, Christine; Barbeau, Jean; Charette, Steve J.

    2015-01-01

    Pseudomonas aeruginosa displays broad genetic diversity, giving it an astonishing capacity to adapt to a variety of environments and to infect a wide range of hosts. While many P. aeruginosa isolates of various origins have been analyzed, isolates from cystic fibrosis (CF) patients have received the most attention. Less is known about the genetic and phenotypic diversity of P. aeruginosa isolates that colonize other environments where flourishing biofilms can be found. In the present study, 29 P. aeruginosa isolates from dental unit waterlines and CF patients were collected and their genetic and phenotypes profiles were compared to determine whether environmental and clinical isolates are related. The isolates were first classified using the random amplified polymorphic DNA method. This made it possible to distribute the isolates into one clinical cluster and two environmental clusters. The isolates in the environmental cluster that were genetically closer to the clinical cluster also displayed phenotypes similar to the clinical isolates. The isolates from the second environmental cluster displayed opposite phenotypes, particularly an increased capacity to form biofilms. The isolates in this cluster were also the only ones harboring genes that encoded specific epimerases involved in the synthesis of lipopolysaccharides, which could explain their increased ability to form biofilms. In conclusion, the isolates from the dental unit waterlines could be distributed into two clusters, with some of the environmental isolates resembled the clinical isolates. PMID:25653647

  9. Tracking down antibiotic-resistant Pseudomonas aeruginosa isolates in a wastewater network.

    PubMed

    Slekovec, Céline; Plantin, Julie; Cholley, Pascal; Thouverez, Michelle; Talon, Daniel; Bertrand, Xavier; Hocquet, Didier

    2012-01-01

    The Pseudomonas aeruginosa-containing wastewater released by hospitals is treated by wastewater treatment plants (WWTPs), generating sludge, which is used as a fertilizer, and effluent, which is discharged into rivers. We evaluated the risk of dissemination of antibiotic-resistant P. aeruginosa (AR-PA) from the hospital to the environment via the wastewater network. Over a 10-week period, we sampled weekly 11 points (hospital and urban wastewater, untreated and treated water, sludge) of the wastewater network and the river upstream and downstream of the WWTP of a city in eastern France. We quantified the P. aeruginosa load by colony counting. We determined the susceptibility to 16 antibiotics of 225 isolates, which we sorted into three categories (wild-type, antibiotic-resistant and multidrug-resistant). Extended-spectrum β-lactamases (ESBLs) and metallo-β-lactamases (MBLs) were identified by gene sequencing. All non-wild-type isolates (n = 56) and a similar number of wild-type isolates (n = 54) were genotyped by pulsed-field gel electrophoresis and multilocus sequence typing. Almost all the samples (105/110, 95.5%) contained P. aeruginosa, with high loads in hospital wastewater and sludge (≥3×10(6) CFU/l or/kg). Most of the multidrug-resistant isolates belonged to ST235, CC111 and ST395. They were found in hospital wastewater and some produced ESBLs such as PER-1 and MBLs such as IMP-29. The WWTP greatly reduced P. aeruginosa counts in effluent, but the P. aeruginosa load in the river was nonetheless higher downstream than upstream from the WWTP. We conclude that the antibiotic-resistant P. aeruginosa released by hospitals is found in the water downstream from the WWTP and in sludge, constituting a potential risk of environmental contamination.

  10. AMINOGLYCOSIDE RESISTANCE GENES IN Pseudomonas aeruginosa ISOLATES FROM CUMANA, VENEZUELA.

    PubMed

    Teixeira, Bertinellys; Rodulfo, Hectorina; Carreño, Numirin; Guzmán, Militza; Salazar, Elsa; De Donato, Marcos

    2016-01-01

    The enzymatic modification of aminoglycosides by aminoglycoside-acetyltransferases (AAC), aminoglycoside-adenyltransferases (AAD), and aminoglycoside-phosphotransferases (APH), is the most common resistance mechanism in P. aeruginosa and these enzymes can be coded on mobile genetic elements that contribute to their dispersion. One hundred and thirty seven P. aeruginosa isolates from the University Hospital, Cumana, Venezuela (HUAPA) were evaluated. Antimicrobial susceptibility was determined by the disk diffusion method and theaac, aadB and aph genes were detected by PCR. Most of the P. aeruginosa isolates (33/137) were identified from the Intensive Care Unit (ICU), mainly from discharges (96/137). The frequency of resistant P. aeruginosaisolates was found to be higher for the aminoglycosides tobramycin and amikacin (30.7 and 29.9%, respectively). Phenotype VI, resistant to these antibiotics, was the most frequent (14/49), followed by phenotype I, resistant to all the aminoglycosides tested (12/49). The aac(6´)-Ib,aphA1 and aadB genes were the most frequently detected, and the simultaneous presence of several resistance genes in the same isolate was demonstrated. Aminoglycoside resistance in isolates ofP. aeruginosa at the HUAPA is partly due to the presence of the aac(6´)-Ib, aphA1 andaadB genes, but the high rates of antimicrobial resistance suggest the existence of several mechanisms acting together. This is the first report of aminoglycoside resistance genes in Venezuela and one of the few in Latin America.

  11. AMINOGLYCOSIDE RESISTANCE GENES IN Pseudomonas aeruginosa ISOLATES FROM CUMANA, VENEZUELA

    PubMed Central

    TEIXEIRA, Bertinellys; RODULFO, Hectorina; CARREÑO, Numirin; GUZMÁN, Militza; SALAZAR, Elsa; DONATO, Marcos DE

    2016-01-01

    The enzymatic modification of aminoglycosides by aminoglycoside-acetyltransferases (AAC), aminoglycoside-adenyltransferases (AAD), and aminoglycoside-phosphotransferases (APH), is the most common resistance mechanism in P. aeruginosa and these enzymes can be coded on mobile genetic elements that contribute to their dispersion. One hundred and thirty seven P. aeruginosa isolates from the University Hospital, Cumana, Venezuela (HUAPA) were evaluated. Antimicrobial susceptibility was determined by the disk diffusion method and theaac, aadB and aph genes were detected by PCR. Most of the P. aeruginosa isolates (33/137) were identified from the Intensive Care Unit (ICU), mainly from discharges (96/137). The frequency of resistant P. aeruginosaisolates was found to be higher for the aminoglycosides tobramycin and amikacin (30.7 and 29.9%, respectively). Phenotype VI, resistant to these antibiotics, was the most frequent (14/49), followed by phenotype I, resistant to all the aminoglycosides tested (12/49). The aac(6´)-Ib,aphA1 and aadB genes were the most frequently detected, and the simultaneous presence of several resistance genes in the same isolate was demonstrated. Aminoglycoside resistance in isolates ofP. aeruginosa at the HUAPA is partly due to the presence of the aac(6´)-Ib, aphA1 andaadB genes, but the high rates of antimicrobial resistance suggest the existence of several mechanisms acting together. This is the first report of aminoglycoside resistance genes in Venezuela and one of the few in Latin America. PMID:27007556

  12. Pseudomonas aeruginosa population structure revisited under environmental focus: impact of water quality and phage pressure.

    PubMed

    Selezska, Katherina; Kazmierczak, Marlon; Müsken, Mathias; Garbe, Julia; Schobert, Max; Häussler, Susanne; Wiehlmann, Lutz; Rohde, Christine; Sikorski, Johannes

    2012-08-01

    Pseudomonas aeruginosa attracts research attention as a common opportunistic nosocomial pathogen causing severe health problems in humans. Nevertheless, its primary habitat is the natural environment. Here, we relate the genetic diversity of 381 environmental isolates from rivers in northern Germany to ecological factors such as river system, season of sampling and different levels of water quality. From representatives of 99 environmental clones, also in comparison with 91 clinical isolates, we determined motility phenotypes, virulence factors, biofilm formation, serotype and the resistance to seven environmental P.aeruginosa phages. The integration of genetic, ecological and phenotypic data showed (i) the presence of several extended clonal complexes (ecc) which are non-uniformly distributed across different water qualities, and (ii) a correlation of the hosts' serotype composition with susceptibility towards distinct groups of environmental phages. For at least one ecc (eccB), we assumed the ecophysiological differences on environmental water adaptation and phage resistance to be so distinct as to reinforce an environmentally driven cladogenic split from the remainder of P.aeruginosa. In summary, we conclude that the majority of the microevolutionary population dynamics of P.aeruginosa were shaped by the natural environment and not by the clinical habitat.

  13. Epidemiological investigation of Pseudomonas aeruginosa nosocomial bacteraemia isolates by PCR-based DNA fingerprinting analysis.

    PubMed

    Liu, Y; Davin-Regli, A; Bosi, C; Charrel, R N; Bollet, C

    1996-11-01

    Between July 1994 and March 1995, 64 isolates of Pseudomonas aeruginosa were implicated in bacteraemia in 25 cancer patients in five wards of two hospitals. These, together with 24 environmental isolates and one isolate from a bacteraemia in a non-cancer patient were examined by three PCR-based DNA fingerprinting methods: random amplified polymorphic DNA (RAPD), enterobacterial-repetitive intergenic consensus (ERIC)-PCR, and 16S-23S spacer region-based RAPD. These methods were reproducible, discriminatory and showed close agreement; all indicated that 47 isolates that had caused bacteraemia in 19 cancer patients were indistinguishable. Seventeen other isolates that had caused bacteraemia in 10 cancer patients were discriminated into eight further groups, and the 24 environmental and non-cancer patient isolates into further distinct groups. No environmental source of the epidemic strain was found, but it was suspected that the outbreak was related to infusion implants.

  14. Characterization of colony morphology variants isolated from Pseudomonas aeruginosa biofilms.

    PubMed

    Kirisits, Mary Jo; Prost, Lynne; Starkey, Melissa; Parsek, Matthew R

    2005-08-01

    In this study, we report the isolation of small, rough, strongly cohesive colony morphology variants from aging Pseudomonas aeruginosa PAO1 biofilms. Similar to many of the P. aeruginosa colony morphology variants previously described in the literature, these variants autoaggregate in liquid culture and hyperadhere to solid surfaces. They also exhibit increased hydrophobicity and reduced motility compared to the wild-type parent strain. Despite the similarities in appearance of our colony morphology variant isolates on solid medium, the isolates showed a range of responses in various phenotypic assays. These variants form biofilms with significant three-dimensional structure and more biomass than the wild-type parent. To further explore the nature of the variants, their transcriptional profiles were evaluated. The variants generally showed increased expression of the psl and pel loci, which have been previously implicated in the adherence of P. aeruginosa to solid surfaces. When a mutation in the psl locus was introduced into a colony morphology variant, the colony morphology was only partially affected, but hyperadherence and autoaggregation were lost. Finally, similar colony morphology variants were found in isolates from cystic fibrosis patients. These variants displayed many of the same characteristics as the laboratory variants, suggesting a link between laboratory and cystic fibrosis biofilms.

  15. High level of resistance to aztreonam and ticarcillin in Pseudomonas aeruginosa isolated from soil of different crops in Brazil.

    PubMed

    Pitondo-Silva, André; Martins, Vinicius Vicente; Fernandes, Ana Flavia Tonelli; Stehling, Eliana Guedes

    2014-03-01

    Pseudomonas aeruginosa can be found in water, soil, plants and, human and animal fecal samples. It is an important nosocomial pathogenic agent characterized by an intrinsic resistance to multiple antimicrobial agents and the ability to develop high-level (acquired) multidrug resistance through some mechanisms, among them, by the acquisition of plasmids and integrons, which are mobile genetic elements. In this study, 40 isolates from Brazilian soil were analyzed for antibiotic resistance, presence of integrons and plasmidial profile. The results demonstrated that the vast majority of the isolates have shown resistance for aztreonam (92.5%, n=37) and ticarcillin (85%, n=34), four isolates presented plasmids and eight isolates possess the class 1 integron. These results demonstrated that environmental isolates of P. aeruginosa possess surprising antibiotic resistance profile to aztreonam and ticarcillin, two antimicrobial agents for clinical treatment of cystic fibrosis patients and other infections occurred by P. aeruginosa.

  16. First report of VIM-2 metallo-β-lactamases producing Pseudomonas aeruginosa isolates in Morocco.

    PubMed

    Maroui, Itto; Barguigua, Abouddihaj; Aboulkacem, Asmae; Ouarrak, Khadija; Sbiti, Mohammed; Louzi, Housssain; Timinouni, Mohammed; Belhaj, Abdelhaq

    2016-03-01

    The emergence and the rapid spread of Pseudomonas aeruginosa carrying carbapenemases represent a serious threat to public health due to their delicate therapy. This work was performed to establish the resistance profile and to detect carbapenemases producing in 123 P. aeruginosa isolates. Among these 55 are environmental isolates and 68 are from the two major hospitals of Meknes-Tafilalet region in Morocco. All strains were tested against 14 antipseudomonal drugs by disc diffusion method. On carbapenem resistant strains minimum inhibitory concentrations of imipenem were determined by the E-test method. The modified Hodge test and EDTA tests were used for the detection of carbapenemases and metallo-β-lactamases (MBLs), respectively. PCR and DNA sequencing were conducted to detect carbapenemase-encoding genes and the enzyme types. 12% of isolates was susceptible to all antibiotics tested and Carbapenem resistance was observed in 33 P. aeruginosa isolates, 33.3% of them were multi-drug resistant. Among carbapenem resistant strains only two (6.1%) were positive for carbapenemases and also for MBLs. In addition to their resistance to almost all β-lactams tested, the MBLs producing strains were resistant to aminoglycosides. Molecular biology techniques confirmed the phenotypic results obtained for the two strains carbapenemase producers and demonstrated that each one of them carried blaVIM-2. The present study reports the first isolation of blaVIM genes in clinical isolates of P. aeruginosa in Morocco. Such isolates represent a serious emerging threat requiring strict hygiene measures to better control their spread.

  17. Molecular epidemiology provides evidence of genotypic heterogeneity of multidrug-resistant Pseudomonas aeruginosa serotype O:12 outbreak isolates from a pediatric hospital.

    PubMed Central

    Bingen, E; Bonacorsi, S; Rohrlich, P; Duval, M; Lhopital, S; Brahimi, N; Vilmer, E; Goering, R V

    1996-01-01

    Ribotyping randomly amplified polymorphic DNA analysis, and pulsed-field gel electrophoresis were used for the epidemiologic evaluation of eight Pseudomonas aeruginosa O:12 isolates obtained from eight children and two P. aeruginosa O:12 environmental isolates from a hematology ward. Randomly amplified polymorphic DNA analysis and pulsed-field gel electrophoresis were able to discriminate isolates that were indistinguishable by biochemical typing, O serotyping or ribotyping. PMID:8940479

  18. Genotyping of Pseudomonas aeruginosa isolated from cockroaches and human urine.

    PubMed

    Saitou, Keiko; Furuhata, Katsunori; Fukuyama, Masafumi

    2010-10-01

    Molecular-epidemiological analysis of Pseudomonas aeruginosa isolated from cockroaches captured in hospitals and from patient urine was performed, employing randomly amplified polymorphic DNA (RAPD) analysis to investigate the usefulness of RAPD analysis. Four specific bands at positions of 993, 875, 521, and 402 bp were commonly detected using primer 272 in 16 of 45 cockroach-derived strains (35.6%), but not in 21 urine-derived strains. On analysis using primer 208, 4 specific bands at positions of 1,235, 1,138, 1,068, and 303 bp were commonly detected in 15 of the 45 cockroach-derived (33.3%) and 10 of the 21 patient urine-derived (47.6%) strains, in a total of 25 of 66 strains (37.8%). On cluster analysis, 12 (48.5%) and 16 (66.7%) clusters were grouped based on a homology of 89% or greater, using primer 272 and primer 208, respectively, showing that primer 208 was suitable for the confirmation of diversity. Seven patterns were clustered based on 100% homology using either primer, and 6 of these consisted of only cockroach-derived strains. In the individual groups with 100% homology, all strains in the group were isolated at an identical site during the same period. P. aeruginosa isolated from cockroaches showed diverse genotypes suggesting several sources of contamination, indicating the necessity for investigating infection control targeting cockroaches inhabiting hospitals.

  19. Draft Genome Sequences of Pseudomonas aeruginosa Isolates from Wounded Military Personnel.

    PubMed

    Arivett, Brock A; Ream, Dave C; Fiester, Steven E; Kidane, Destaalem; Actis, Luis A

    2016-08-11

    Pseudomonas aeruginosa, a Gram-negative bacterium that causes severe hospital-acquired infections, is grouped as an ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogen because of its extensive drug resistance phenotypes and effects on human health worldwide. Five multidrug resistant P. aeruginosa strains isolated from wounded military personnel were sequenced and annotated in this work.

  20. Carbapenem Susceptibility and Multidrug-Resistance in Pseudomonas aeruginosa Isolates in Egypt

    PubMed Central

    Hashem, Hany; Hanora, Amro; Abdalla, Salah; Shawky, Alaa; Saad, Alaa

    2016-01-01

    Background Resistant Pseudomonas aeruginosa is a serious concern for antimicrobial therapy, as the common isolates exhibit variable grades of resistance, involving beta-lactamase enzymes, beside native defense mechanisms. Objectives The present study was designed to determine the occurrence of Metallo-β- Lactamases (MBL) and Amp C harboring P. aeruginosa isolates from Suez Canal university hospital in Ismailia, Egypt. Methods A total of 147 P. aeruginosa isolates, recovered from 311 patients during a 10-month period, were collected between May 2013 and February 2014; the isolates were collected from urine, wound and sputum. Minimum inhibitory concentration (MIC) determined by agar dilution methods was ≥2 μg/mL for meropenem and imipenem. Identification of P. aeruginosa was confirmed using API 20NE. Metallo-β- Lactamases and Amp C were detected based on different phenotypic methods. Results Overall, 26.5% of P. aeruginosa isolates (39/147) were carbapenem resistant isolates. Furthermore, 64.1% (25/39) were MBL producers, these isolates were screened by the combined disc and disc diffusion methods to determine the ability of MBL production. Both MBL and Amp C harbored P. aeruginosa isolates were 28% (7/25). Sixty-four percent of P. aeruginosa isolates were multidrug resistant (MDR) (16/25). The sensitivity toward polymyxin, imipenem, norfloxacin, piperacillin-tazobactam and gentamicin was 99%, 91%, 88%, 82% and 78%, respectively. The resistance rate towards cefotaxime, ceftazidime, cefepime, aztreonam and meropenem was 98.6%, 86%, 71.4%, 34% and 30%, respectively. Conclusions Multidrug resistance was significantly associated with MBL production in P. aeruginosa. Early detection of MBL-producing P. aeruginosa and hospital antibiotic policy prescription helps proper antimicrobial therapy and avoidance of dissemination of these multidrug resistance isolates. PMID:28138370

  1. Draft Genome Sequence of Beneficial Rice Rhizosphere Isolate Pseudomonas aeruginosa PUPa3

    PubMed Central

    Uzelac, Gordana; Bertani, Iris; Kojic, Milan; Paszkiewicz, Konrad H.; Studholme, David J.; Passos da Silva, Daniel

    2014-01-01

    Pseudomonas aeruginosa PUPa3 is a rhizosphere-colonizing and plant growth-promoting strain isolated from the rhizosphere of rice. This strain has, however, been shown to be pathogenic in two nonmammalian infection models. Here we report the draft genome sequence of P. aeruginosa PUPa3. PMID:24994800

  2. Draft Genome Sequence of Beneficial Rice Rhizosphere Isolate Pseudomonas aeruginosa PUPa3.

    PubMed

    Uzelac, Gordana; Bertani, Iris; Kojic, Milan; Paszkiewicz, Konrad H; Studholme, David J; Passos da Silva, Daniel; Venturi, Vittorio

    2014-07-03

    Pseudomonas aeruginosa PUPa3 is a rhizosphere-colonizing and plant growth-promoting strain isolated from the rhizosphere of rice. This strain has, however, been shown to be pathogenic in two nonmammalian infection models. Here we report the draft genome sequence of P. aeruginosa PUPa3.

  3. Effect of Tyrosol and Farnesol on Virulence and Antibiotic Resistance of Clinical Isolates of Pseudomonas aeruginosa.

    PubMed

    Abdel-Rhman, Shaymaa Hassan; El-Mahdy, Areej Mostafa; El-Mowafy, Mohammed

    2015-01-01

    Mixed-species biofilms could create a protected environment that allows for survival to external antimicrobials and allows different bacterial-fungal interactions. Pseudomonas aeruginosa-Candida albicans coexistence is an example for such mixed-species community. Numerous reports demonstrated how P. aeruginosa or its metabolites could influence the growth, morphogenesis, and virulence of C. albicans. In this study, we investigated how the C. albicans quorum sensing compounds, tyrosol and farnesol, might affect Egyptian clinical isolates of P. aeruginosa regarding growth, antibiotic sensitivity, and virulence. We could demonstrate that tyrosol possesses an antibacterial activity against P. aeruginosa (10 µM inhibited more than 50% of growth after 16 h cultivation). Moreover, we could show for the first time that tyrosol strongly inhibits the production of the virulence factors hemolysin and protease in P. aeruginosa, whereas farnesol inhibits, to lower extent, hemolysin production in this bacterial pathogen. Cumulatively, tyrosol is expected to strongly affect P. aeruginosa in mixed microbial biofilm.

  4. Draft Genome Sequence of Microcystis aeruginosa CACIAM 03, a Cyanobacterium Isolated from an Amazonian Freshwater Environment

    PubMed Central

    Castro, Wendel Oliveira; Lima, Alex Ranieri Jerônimo; Moraes, Pablo Henrique Gonçalves; Siqueira, Andrei Santos; Aguiar, Délia Cristina Figueira; Baraúna, Anna Rafaella Ferreira; Martins, Luisa Carício; Fuzii, Hellen Thais; de Lima, Clayton Pereira Silva; Vianez-Júnior, João Lídio Silva Gonçalves; Nunes, Márcio Roberto Teixeira; Dall'Agnol, Leonardo Teixeira

    2016-01-01

    Given its toxigenic potential, Microcystis aeruginosa is an important bloom-forming cyanobacterium. Here, we present a draft genome and annotation of the strain CACIAM 03, which was isolated from an Amazonian freshwater environment. PMID:27856592

  5. SERS detection of the biomarker hydrogen cyanide from Pseudomonas aeruginosa cultures isolated from cystic fibrosis patients

    PubMed Central

    Lauridsen, Rikke Kragh; Sommer, Lea M.; Johansen, Helle Krogh; Rindzevicius, Tomas; Molin, Søren; Jelsbak, Lars; Engelsen, Søren Balling; Boisen, Anja

    2017-01-01

    Pseudomonas aeruginosa is the primary cause of chronic airway infections in cystic fibrosis (CF) patients. Persistent infections are seen from the first P. aeruginosa culture in about 75% of young CF patients, and it is important to discover new ways to detect P. aeruginosa at an earlier stage. The P. aeruginosa biomarker hydrogen cyanide (HCN) contains a triple bond, which is utilized in this study because of the resulting characteristic C≡N peak at 2135 cm−1 in a Raman spectrum. The Raman signal was enhanced by surface-enhanced Raman spectroscopy (SERS) on a Au-coated SERS substrate. After long-term infection, a mutation in the patho-adaptive lasR gene can alter the expression of HCN, which is why it is sometimes not possible to detect HCN in the breath of chronically infected patients. Four P. aeruginosa reference strains and 12 clinical P. aeruginosa strains isolated from CF children were evaluated, and HCN was clearly detected from overnight cultures of all wild type-like isolates and half of the later isolates from the same patients. The clinical impact could be that P. aeruginosa infections could be detected at an earlier stage, because daily breath sampling with an immediate output could be possible with a point-of-care SERS device. PMID:28349938

  6. Pseudomonas aeruginosa isolates in severe chronic obstructive pulmonary disease: characterization and risk factors

    PubMed Central

    2014-01-01

    Background Patients with severe chronic obstructive pulmonary disease (COPD) are at increased risk of infection by P. aeruginosa. The specific role of bronchiectasis in both infection and chronic colonization by this microorganism in COPD, however, remains ill defined. To evaluate the prevalence and risk factors for P. aeruginosa recovery from sputum in outpatients with severe COPD, characterizing P. aeruginosa isolates by pulsed-field gel electrophoresis (PFGE) and focusing on the influence of bronchiectasis on chronic colonization in these patients. Methods A case-cohort study of 118 patients with severe COPD attended at a Respiratory Day Unit for an acute infectious exacerbation and followed up over one year. High-resolution CT scans were performed during stability for bronchiectasis assessment and sputum cultures were obtained during exacerbation and stability in all patients. P. aeruginosa isolates were genotyped by PFGE. Determinants of the recovery of P. aeruginosa in sputum and chronic colonization by this microorganism were assessed by multivariate analysis. Results P. aeruginosa was isolated from 41 of the 118 patients studied (34.7%). Five of these 41 patients (12.2%) with P. aeruginosa recovery fulfilled criteria for chronic colonization. In the multivariate analysis, the extent of bronchiectasis (OR 9.8, 95% CI: 1.7 to 54.8) and the number of antibiotic courses (OR 1.7, 95% CI: 1.1 to 2.5) were independently associated with an increased risk of P. aeruginosa isolation. Chronic colonization was unrelated to the presence of bronchiectasis (p=0.75). In patients with chronic colonization the isolates of P. aeruginosa retrieved corresponded to the same clones during the follow-up, and most of the multidrug resistant isolates (19/21) were harbored by these patients. Conclusions The main risk factors for P. aeruginosa isolation in severe COPD were the extent of bronchiectasis and exposure to antibiotics. Over 10% of these patients fulfilled criteria for

  7. Characterization of Toxin-Antitoxin (TA) Systems in Pseudomonas aeruginosa Clinical Isolates in Iran

    PubMed Central

    Savari, Mohammad; Rostami, Soodabeh; Ekrami, Alireza; Bahador, Abbas

    2016-01-01

    Background: Pseudomonas aeruginosa is among the most problematic hospital and community-acquired pathogens. Toxin-antitoxin (TA) systems are maintenance regulatory systems in bacteria and have recently been considered new targets for antimicrobial therapy. The prevalence and transcription of these systems in clinical isolates are still unknown. Objectives: The aim of this study was to characterize three types of TA systems (parDE, relBE, and higBA) among P. aeruginosa clinical isolates. Materials and Methods: We typed our clinical isolates by ERIC-PCR (enterobacterial repetitive intergenic consensus sequence-based polymerase chain reaction) and BOX-PCR. We then investigated 174 P. aeruginosa clinical isolates from three hospitals in Ahvaz, Iran, for the presence of TA system genes, and determined whether these systems were encoded on chromosomes or plasmids by amplification of the flanking regions. Results: Our results showed that in the 174 P. aeruginosa isolates, relBE and higBA were universal, but parDE was less prevalent. Both of the flanking regions of the parDE genes in all positive isolates were amplified. The flanking regions of nearly all relBE genes were amplified. Amplification was observed for the downstream sequence of every higBA locus, as well as for the region upstream of higBA, except in 14 strains. Conclusions: Based on the presence of TA systems in the majority of P. aeruginosa isolates, these could be used as a novel target for antimicrobial therapy. PMID:27099681

  8. Drug Resistance of Pseudomonas aeruginosa and Enterobacter cloacae Isolated from ICU, Babol, Northern Iran

    PubMed Central

    Bayani, Masoomeh; Siadati, Sepideh; Rajabnia, Ramzan; Taher, Ali Asghar

    2013-01-01

    Multidrug resistant (MDR) bacteria are spread throughout the world which causes nosocomial infections, especially in Intensive Care Unit (ICU). This study aimed to investigate the resistance pattern of Pseudomonas aeruginosa and Enterobacter cloacae isolated from patients in the ICU. During 2011-2012, 30 isolates for each P. aeruginosa and E. cloacae were collected from the patients who acquired nosocomial infection after admition to the ICU at the hospitals affiliated to Babol University of Medical Sciences, Babol, northern Iran. Antimicrobial susceptibility test was performed for five category antibiotics by microdilution method. The data were analyzed by SPSS version 20 and p<0.05 was considered statistically significant. The highest resistance rate of P. aeruginosa was seen to amikacin (53.3%) followed by ceftazidime (43.3%). Also, 16.7% of E. cloacae was resistant to ceftazidime. Among P. aeruginosa isolates,18 (60%) were MDR while no E. cloacae isolates were MDR. The significant correlation was only demonstrated between MDR P. aeruginosa and the reason of hospitalization (P=0.004). In conclusion, there was alarming amount of P. aeruginosa MDR in patients in the ICU which could lead to a hazardous outcome for the patients. Therefore, new prevention policies regarding to hospital infection should be established. Also, the periodical assessment of bacterial resistance pattern particularly in ICUs should be performed. PMID:24551814

  9. Honey as an Antimicrobial Agent Against Pseudomonas Aeruginosa Isolated from Infected Wounds

    PubMed Central

    Shenoy, Vishnu Prasad; Ballal, Mamatha; Shivananda, PG; Bairy, Indira

    2012-01-01

    Background: As natural products garner attention in the medical field due to emergence of antibiotic resistant strains of bacteria, honey is valued for its antibacterial activity. Objective: Fifty strains of Pseudomonas aeruginosa isolated from infected wounds were evaluated for their antibacterial action using honey in comparison with different antibiotics and Dettol. Methodology and Results: All the strains were found to be sensitive to honey at a minimum inhibitory concentration of 20% in comparison with Dettol at 10% using agar dilution method. In the second step, the time kill assay was performed on five isolates of P. aeruginosa to demonstrate the bactericidal activity of honey at different dilutions of honey ranging from 20% to 100% at regular time intervals. All the isolates of P. aeruginosa tested were killed in 12-24 h depending on the dilutions of the honey tested. Thus, honey could prevent the growth of P. aeruginosa even if it was diluted by deionized water by fivefolds in vitro. Honey had almost uniform bactericidal activity against P. aeruginosa irrespective of their susceptibility to different classes of antibiotics. Conclusion: Honey which is a natural, non-toxic, and an inexpensive product has activity against the P. aeruginosa isolated from infected wounds may make it an alternative topical choice in the treatment of wound infections. PMID:22754244

  10. Use of the paraffin wax baiting system for identification of Pseudomonas aeruginosa clinical isolates.

    PubMed

    Massengale, A R; Ollar, R A; Giordano, S J; Felder, M S; Aronoff, S C

    1999-11-01

    Pseudomonas aeruginosa is the primary pathogen among the Pseudomonads and is known for its minimal nutritional requirements, capacity to use paraffin as a sole carbon source, and biofilm formation. Because the ability of Pseudomonads to grow on paraffin is not commonly found among human pathogens and the primary Pseudomonas human pathogen is P. aeruginosa, we studied the adaptation of the paraffin baiting system for the growth and identification of clinical isolates of P. aeruginosa. We also studied the effectiveness of combining a fluorescence assay measuring fluorescein (pyoverdin) production and oxidase test with the paraffin baiting assay for P. aeruginosa speciation. Strains were tested for the capacity to use paraffin as a sole carbon source using the paraffin baiting system with Czapek's minimal salt medium. Of 111 P. aeruginosa clinical isolates tested for using paraffin as a sole carbon source, 45% exhibited growth on paraffin at 24 h and 76.6% exhibited growth on paraffin at 48 h. The ability of the reference strains and clinical isolates were then tested for their ability to associate with the paraffin slide in the presence of an additional carbon source. Of 111 P. aeruginosa clinical isolates tested, 85 strains (76.6%), and 102 (93%) were associated with the paraffin surface at 24 and 48 h. We successfully combined fluorescence and oxidase assays with the paraffin baiting system for identification of P. aeruginosa. The simple and inexpensive paraffin baiting system is a useful method for the identification and study of P. aeruginosa suitable for both the clinical and research laboratory.

  11. Antibiotic Tolerance Induced by Lactoferrin in Clinical Pseudomonas aeruginosa Isolates from Cystic Fibrosis Patients

    PubMed Central

    Andrés, María T.; Viejo-Diaz, Mónica; Pérez, Francisco; Fierro, José F.

    2005-01-01

    Lactoferrin-induced cell depolarization and a delayed tobramycin-killing effect on Pseudomonas aeruginosa cells were correlated. This antibiotic tolerance effect (ATE) reflects the ability of a defense protein to modify the activity of an antibiotic as a result of its modulatory effect on bacterial physiology. P. aeruginosa isolates from cystic fibrosis patients showed higher ATE values (≤6-fold) than other clinical strains. PMID:15793153

  12. Molecular detection of virulence genes as markers in Pseudomonas aeruginosa isolated from urinary tract infections.

    PubMed

    Sabharwal, Neha; Dhall, Shriya; Chhibber, Sanjay; Harjai, Kusum

    2014-01-01

    Catheter associated urinary tract infections by P. aeruginosa are related to variety of complications. Quorum sensing and related circuitry guard its virulence potential. Though P. aeruginosa accounts for an appreciable amount of virulence factors, this organism is highly unstable phenotypically. Thus, genotyping of clinical isolates of P. aeruginosa is of utmost importance for understanding the epidemiology of infection. This may contribute towards development of immunotherapeutic approaches against this multi drug resistant pathogen. Moreover, no epidemiological study has been reported yet on uroisolates of P. aeruginosa. Thus this study was planned to obtain information regarding presence, distribution and rate of occurrence of quorum sensing and some associated virulence genes at genetic level. The profiling of quorum sensing genes lasI, lasR, rhlI, rhlR and virulence genes like toxA, aprA, rhlAB, plcH, lasB and fliC of twelve strains of P. aeruginosa isolated from patients with UTIs was done by direct PCR. The results showed variable distribution of quorum sensing genes and virulence genes. Their percentage occurrence may be specifically associated with different levels of intrinsic virulence and pathogenicity in urinary tract. Such information can help in identifying these virulence genes as useful diagnostic markers for clinical P. aeruginosa strains isolated from UTIs.

  13. Genetic characterization of Microcystis aeruginosa isolates from Portuguese freshwater systems.

    PubMed

    Moreira, Cristiana; Vasconcelos, Vitor; Antunes, Agostinho

    2016-07-01

    Cyanobacteria are microorganisms that pose a serious threat to the aquatic waterways through the production of dense blooms under eutrophic conditions and the release of toxic secondary metabolites-cyanotoxins. Within cyanobacteria, the colonial planktonic Microcystis aeruginosa is widely distributed in both fresh and brackish aquatic environments throughout the world being frequently observed in the Portuguese water systems. Apart from the well-established distribution of M. aeruginosa in Portugal, knowledge of its genetic diversity and population structure is unknown. Therefore, in this study twenty-seven strains were obtained from the North, Centre and South regions of Portugal and were subjected to extensive phylogenetic analyses using simultaneously four distinct genetic markers (16S rRNA, 16S-23S ITS, DNA gyrase subunit ß and cell division protein (ftsZ)) encompassing in total 2834 bp. With this work we characterized the phylogenetic relationship among the Portuguese strains, with the southern strains showing higher genetic structure relatively to the North and Centre strains. A total of fifteen genotypes were determined for M. aeruginosa in Portuguese water systems revealing a high genetic diversity. This is also the first study to report geographic variation on the population structure of the Portuguese M. aeruginosa.

  14. Photodynamic antimicrobial therapy to inhibit pseudomonas aeruginosa of corneal isolates (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Durkee, Heather A.; Relhan, Nidhi; Arboleda, Alejandro; Halili, Francisco; De Freitas, Carolina; Alawa, Karam; Aguilar, Mariela C.; Amescua, Guillermo; Miller, Darlene; Parel, Jean-Marie

    2016-03-01

    Keratitis associated with Pseudomonas aeruginosa is difficult to manage. Treatment includes antibiotic eye drops, however, some strains of Pseudomonas aeruginosa are resistant. Current research efforts are focused on finding alternative and adjunct therapies to treat multi-drug resistant bacteria. One promising alternate technique is photodynamic therapy (PDT). The purpose of this study was to evaluate the effect of riboflavin- and rose bengal-mediated PDT on Pseudomonas aeruginosa keratitis isolates in vitro. Two isolates (S+U- and S-U+) of Pseudomonas aeruginosa were derived from keratitis patients and exposed to five experimental groups: (1) Control (dark, UV-A irradiation, 525nm irradiation); (2) 0.1% riboflavin (dark, UV-A irradiation); and (3) 0.1% rose bengal, (4) 0.05% rose bengal and (5) 0.01% rose bengal (dark, 525nm irradiation). Three days after treatment, in dark conditions of all concentration of riboflavin and rose bengal showed no inhibition in both S+U- and S-U+ strains of Pseudomonas aeruginosa. In 0.1% and 0.05% rose bengal irradiated groups, for both S+U- and S-U+ strains, there was complete inhibition of bacterial growth in the central 50mm zone corresponding to the diameter of the green light source. These in vitro results suggest that rose bengal photodynamic therapy may be an effective adjunct treatment for Pseudomonas aeruginosa keratitis.

  15. Emergence of KPC-2-Producing Pseudomonas aeruginosa Sequence Type 463 Isolates in Hangzhou, China

    PubMed Central

    Hu, Yan-yan; Gu, Dan-xia; Cai, Jia-chang; Zhou, Hong-wei

    2015-01-01

    Thirty-nine Klebsiella pneumoniae carbapenemase (KPC)-producing Pseudomonas aeruginosa isolates, all exhibiting high-level resistance to carbapenems and other β-lactam antibiotics, were isolated in Hangzhou, China. Molecular epidemiology analysis indicated the presence of two dominant clones, namely, clones A and B, both of which belong to sequence type 463 (ST463). A genetic environment analysis demonstrated that both clones harbor an ISKpn8 transposase, blaKPC-2, and an ISKpn6-like transposase. These findings depict the features of clonal expansion and transmission of KPC-2-producing P. aeruginosa strains in Hangzhou, China. PMID:25691651

  16. In vitro antimicrobial resistance of Pseudomonas aeruginosa isolated from canine otitis externa in Rio de Janeiro, Brazil

    PubMed Central

    Penna, B.; Thomé, S.; Martins, R.; Martins, G.; Lilenbaum, W.

    2011-01-01

    Isolates of Pseudomonas aeruginosa (167) were obtained from 528 samples of canine otitis externa, identified by biochemical reactions and tested for susceptibility to 10 antimicrobials. The most effective drug was ciprofloxacin. The study reports alarming resistance among P. aeruginosa isolated from canine otitis externa samples in Rio de Janeiro, Brazil. PMID:24031774

  17. Diversity of Molecular Mechanisms Conferring Carbapenem Resistance to Pseudomonas aeruginosa Isolates from Saudi Arabia

    PubMed Central

    Jeannot, Katy; El-Mahdy, Taghrid S.; Samaha, Hassan A.; Shibl, Atef M.; Plésiat, Patrick; Courvalin, Patrice

    2016-01-01

    Background. This study described various molecular and epidemiological characters determining antibiotic resistance patterns in Pseudomonas aeruginosa isolates. Methods. A total of 34 carbapenem-resistant P. aeruginosa clinical isolates were isolated from samples collected at a tertiary hospital in Riyadh, Saudi Arabia, from January to December 2011. Susceptibility testing, serotyping, molecular characterization of carbapenem resistance, and pulsed-field gel electrophoresis (PFGE) were performed. Results. All isolates were resistant to ceftazidime, and more than half were highly resistant (minimum inhibitory concentration (MIC) > 256 mg/L). Fifteen isolates had MIC values ≥64 mg/L for any of the carbapenems examined. Vietnamese extended-spectrum β-lactamase (VEB-1) (n = 16/34) and oxacillinase (OXA-10) (n = 14/34) were the most prevalent extended-spectrum β-lactamase and penicillinase, respectively. Verona imipenemase (VIM-1, VIM-2, VIM-4, VIM-11, and VIM-28) and imipenemase (IMP-7) variants were found in metallo-β-lactamase producers. A decrease in outer membrane porin gene (oprD) expression was seen in nine isolates, and an increase in efflux pump gene (MexAB) expression was detected in five isolates. Six serotypes (O:1, O:4, O:7, O:10, O:11, and O:15) were found among the 34 isolates. The predominant serotype was O:11 (16 isolates), followed by O:15 (nine isolates). PFGE analysis of the 34 carbapenem-resistant P. aeruginosa isolates revealed 14 different pulsotypes. Conclusions. These results revealed diverse mechanisms conferring carbapenem resistance to P. aeruginosa isolates from Saudi Arabia. PMID:27597874

  18. Isolation and characterization of quorum-sensing signalling molecules in Pseudomonas aeruginosa isolates recovered from nosocomial infections.

    PubMed

    Lakshmana Gowda, Krishnappa; John, James; Marie, Mohammed A M; Sangeetha, Gopalkrishnan; Bindurani, Shanta Range

    2013-09-01

    Pseudomonas aeruginosa is one of the most common pathogens in nosocomial infections. Many studies have documented the role of quorum-sensing (QS) systems in antibiotic tolerance of P. aeruginosa. N-acyl homoserine lactones (AHLs) serve as QS signalling molecules and can be a target for modulating bacterial pathogenicity. In this study, nosocomial isolates of P. aeruginosa were characterized for the presence of different types of QS signalling molecules. AHLs were solvent extracted and quantified by determination of β-galactosidase activity using the Escherichia coli MG4 reporter strain. Further characterization was performed by analytical thin layer chromatography coupled with detection using the Agrobacterium tumefaciens A136 biosensor strain. All P. aeruginosa isolates produced AHLs, but there were differences in the quantity and nature of AHLs. We identified AHLs belonging to C4-homoserine lactone (HSL), C6-HSL, C8-HSL, C10-HSL and C12-HSL. AHL profiling of P. aeruginosa isolates showed differences in the amounts and types of AHLs, suggesting differences in the virulence factors and the potential for infection. Our results may be investigated further using animal model systems.

  19. Effect of Tyrosol and Farnesol on Virulence and Antibiotic Resistance of Clinical Isolates of Pseudomonas aeruginosa

    PubMed Central

    Hassan Abdel-Rhman, Shaymaa; Mostafa El-Mahdy, Areej; El-Mowafy, Mohammed

    2015-01-01

    Mixed-species biofilms could create a protected environment that allows for survival to external antimicrobials and allows different bacterial-fungal interactions. Pseudomonas aeruginosa-Candida albicans coexistence is an example for such mixed-species community. Numerous reports demonstrated how P. aeruginosa or its metabolites could influence the growth, morphogenesis, and virulence of C. albicans. In this study, we investigated how the C. albicans quorum sensing compounds, tyrosol and farnesol, might affect Egyptian clinical isolates of P. aeruginosa regarding growth, antibiotic sensitivity, and virulence. We could demonstrate that tyrosol possesses an antibacterial activity against P. aeruginosa (10 µM inhibited more than 50% of growth after 16 h cultivation). Moreover, we could show for the first time that tyrosol strongly inhibits the production of the virulence factors hemolysin and protease in P. aeruginosa, whereas farnesol inhibits, to lower extent, hemolysin production in this bacterial pathogen. Cumulatively, tyrosol is expected to strongly affect P. aeruginosa in mixed microbial biofilm. PMID:26844228

  20. Characterization of Virulence Potential of Pseudomonas Aeruginosa Isolated from Bovine Meat, Fresh Fish, and Smoked Fish

    PubMed Central

    Benie, Comoé Koffi Donatien; Dadié, Adjéhi; Guessennd, Nathalie; N’gbesso-Kouadio, Nadège Ahou; Kouame, N’zebo Désiré; N’golo, David Coulibaly; Aka, Solange; Dako, Etienne; Dje, Koffi Marcellin; Dosso, Mireille

    2017-01-01

    Pseudomonas aeruginosa owns a variability of virulence factors. These factors can increase bacterial pathogenicity and infection severity. Despite the importance of knowledge about them, these factors are not more characterized at level of strains derived from local food products. This study aimed to characterize the virulence potential of P. aeruginosa isolated from various animal products. Several structural and virulence genes of P. aeruginosa including lasB, exoS, algD, plcH, pilB, exoU, and nan1 were detected by polymerase chain reaction (PCR) on 204 strains of P. aeruginosa. They were isolated from bovine meat (122), fresh fish (49), and smoked fish (33). The 16S rRNA gene was detected on 91.1% of the presumptive strains as Pseudomonas. The rpoB gene showed that 99.5% of the strains were P. aeruginosa. The lasB gene (89.2%) was the most frequently detected (p < 0.05). In decreasing importance order, exoS (86.8%), algD (72.1%), plcH (72.1%), pilB (40.2%), and exoU (2.5%) were detected. The lasB gene was detected in all strains of P. aeruginosa serogroups O11 and O16. The prevalence of algD, exoS, and exoU genes in these strains varied from 51.2% to 87.4%. The simultaneous determination of serogroups and virulence factors is of interest for the efficacy of surveillance of infections associated with P. aeruginosa. PMID:28386471

  1. Screening of Molecular Virulence Markers in Staphylococcus aureus and Pseudomonas aeruginosa Strains Isolated from Clinical Infections

    PubMed Central

    Cotar, Ani-Ioana; Chifiriuc, Mariana-Carmen; Dinu, Sorin; Bucur, Marcela; Iordache, Carmen; Banu, Otilia; Dracea, Olguta; Larion, Cristina; Lazar, Veronica

    2010-01-01

    Staphylococcus (S.) aureus and Pseudomonas (Ps.) aeruginosa are two of the most frequently opportunistic pathogens isolated in nosocomial infections, responsible for severe infections in immunocompromised hosts. The frequent emergence of antibiotic-resistant S. aureus and Ps. aeruginosa strains has determined the development of new strategies in order to elucidate the different mechanisms used by these bacteria at different stages of the infectious process, providing the scientists with new procedures for preventing, or at least improving, the control of S. aureus and Ps. aeruginosa infections. The purpose of this study was to characterize the molecular markers of virulence in S. aureus and Ps. aeruginosa strains isolated from different clinical specimens. We used multiplex and uniplex PCR assays to detect the genes encoding different cell-wall associated and extracellular virulence factors, in order to evaluate potential associations between the presence of putative virulence genes and the outcome of infections caused by these bacteria. Our results demonstrate that all the studied S. aureus and Ps. aeruginosa strains synthesize the majority of the investigated virulence determinants, probably responsible for different types of infections. PMID:21614207

  2. Clonal Dissemination of Pseudomonas aeruginosa Isolates Producing Extended-Spectrum β-Lactamase SHV-2a

    PubMed Central

    Jeannot, Katy; Fournier, Damien; Müller, Emeline; Cholley, Pascal

    2013-01-01

    From January to December 2011, 24 Pseudomonas aeruginosa strains producing the extended-spectrum β-lactamase SHV-2a were identified in 13 hospitals in France. With one exception, all the strains belonged to the same clone. Double-disk synergy tests with cefepime and clavulanate were able to detect all the SHV-2a-positive isolates. PMID:23241379

  3. Clonal dissemination of Pseudomonas aeruginosa isolates producing extended-spectrum β-lactamase SHV-2a.

    PubMed

    Jeannot, Katy; Fournier, Damien; Müller, Emeline; Cholley, Pascal; Plésiat, Patrick

    2013-02-01

    From January to December 2011, 24 Pseudomonas aeruginosa strains producing the extended-spectrum β-lactamase SHV-2a were identified in 13 hospitals in France. With one exception, all the strains belonged to the same clone. Double-disk synergy tests with cefepime and clavulanate were able to detect all the SHV-2a-positive isolates.

  4. [Phenotypic and genotypic characterization of imipenem-resistant Pseudomonas aeruginosa isolated in a Buenos Aires hospital].

    PubMed

    Cejas, D; Almuzara, M; Santella, G; Tuduri, A; Palombarani, S; Figueroa, S; Gutkind, G; Radice, M

    2008-01-01

    From 129 P. aeruginosa isolated at a health care centre located in Buenos Aires (Hospital "Eva Perón"), 14% produced IMP-13. Although 18 isolates were metallo-beta-lactamases (MBL) producers, only those isolates that displayed altered outer membrane protein profiles correlated with the resistant category according to CLSI or even Subcomisión de Antimicrobianos, SADEBAC, AAM. Phenotypic screening of metallo-beta-lactamases proved to be appropriate for detecting MBL producing isolates. IMP-13 producing isolates corresponded to at least five different clonal types, which not only suggests the dissemination of the resistant strain but also of the resistant marker.

  5. Biofilm Formation and Virulence Factors Among Pseudomonas aeruginosa Isolated From Burn Patients

    PubMed Central

    Ghanbarzadeh Corehtash, Zahra; Khorshidi, Ahmad; Firoozeh, Farzaneh; Akbari, Hosein; Mahmoudi Aznaveh, Azam

    2015-01-01

    Background: Pseudomonas aeruginosa possesses a variety of virulence factors and infections caused by multidrug-resistant P. aeruginosa (MDRPA) in burn patients are a public health problem. Objectives: The aim of this study was to determine the antibiotic resistance pattern, the biofilm formation, the prevalence of MDRPA and two virulence genes (nan1 and exoA) among P. aeruginosa isolated from burn patients. Patients and Methods: A total of 144 isolates of P. aeruginosa were collected from burn patient at the Burn Centre of Tehran, Iran, between March 2013 and July 2013. Antibiotic susceptibility test was performed via agar disk diffusion method. The ability of producing biofilm was examined by crystal violet microtiter plate assay and the prevalence of the exoA and nan1 genes among the isolates was determined by polymerase chain reaction (PCR). Results: A high rate of resistance was seen against ciprofloxacin (93.7%), aztreonam (86.8%), piperacillin (85.4%), ceftazidime (82.6%), amikacin (82%) and imipenem (79.2%). In total, 93.1% of the isolates were characterized as MDRPA. Biofilm formation was seen in 92.4% of the isolates. The prevalence of the exoA and nan1 genes were 75% and 11.8% among the isolates, respectively. Conclusions: The high rate of MDRPA and its ability to produce biofilm is an alarm for public health. The statistical analysis showed that biofilm production in the MDRPA isolates was significantly higher than that in the non–MDRPA isolates (P < 0.001). PMID:26587205

  6. Isolation of Pseudomonas aeruginosa from cockroaches Captured in hospitals in Japan, and their antibiotic susceptibility.

    PubMed

    Saitou, Keiko; Furuhata, Katsunori; Kawakami, Yasushi; Fukuyama, Masafumi

    2009-12-01

    Pseudomonas aeruginosa strains were isolated from 45 of 370 (12.2%) cockroaches captured in hospitals. By cockroach species, the bacterial strains were isolated from 39 of 181 (21.5%) Periplaneta fuliginosa and 6 of 183 (3.3%) Blattella germanica, showing a significant difference (p<0.01). Many P. aeruginosa-carrying cockroaches inhabited locker rooms (66.7%) and kitchens (17.8%). In terms of serotyping, many isolates were typed into groups A, G, and B. In drug sensitivity tests, strains showed the highest sensitivity to ciprofloxacin with an MIC90 of 0.25 microg/ml, followed by 2 microg/ml meropenem, and 4 microg/ml ceftazidime, gentamicin, and ofloxacin. In contrast, many strains were resistant to cefotaxime and minocycline, accounting for 86.7% of all resistant strains. However, there was no multidrug-resistant P. aeruginosa strain, and all strains were negative for the metallo-beta-lactamase gene (IMP-1 and VIM-2). These findings suggested that cockroach-derived P. aeruginosa may contaminate hospital environments, for which the control of disease-carrying insects in hospitals is important.

  7. Two copies of blaNDM-1 gene are present in NDM-1 producing Pseudomonas aeruginosa isolates from Serbia.

    PubMed

    Jovčić, Branko; Lepšanović, Zorica; Begović, Jelena; Filipić, Brankica; Kojić, Milan

    2014-03-01

    New Delhi metallo-β-lactamase producing Pseudomonas aeruginosa isolates are of special interest since P. aeruginosa is a major cause of nosocomial infections, the treatment of which could now be jeopardized, especially in developing countries. Six additional NDM-1 positive P. aeruginosa clinical isolates belonging to two different genotypes were shown to be plasmid-free. PFGE-hybridization experiments revealed the chromosomal location of the blaNDM-1 gene. Restriction analysis and hybridization revealed that two copies of the blaNDM-1 gene are present in the genomes of all tested isolates, as in previously characterized P. aeruginosa MMA83. Moreover, it was shown that increasing imipenem concentration did not have the effect on copy number of the blaNDM-1 gene in the genome of P. aeruginosa MMA83.

  8. Genetic diversity of clinical Pseudomonas aeruginosa isolates in a public hospital in Spain

    PubMed Central

    2013-01-01

    Background Pseudomonas aeruginosa is an important nosocomial pathogen that exhibits multiple resistances to antibiotics with increasing frequency, making patient treatment more difficult. The aim of the study is to ascertain the population structure of this clinical pathogen in the Hospital Son Llàtzer, Spain. Results A significant set (56) of randomly selected clinical P. aeruginosa isolates, including multidrug and non-multidrug resistant isolates, were assigned to sequence types (STs) and compared them with their antibiotic susceptibility profile classified as follows: extensively drug resistant (XDR), multidrug resistant (MDR) and non-multidrug resistant (non-MDR). The genetic diversity was assessed by applying the multilocus sequence typing (MLST) scheme developed by Curran and collaborators, and by the phylogenetic analysis of a concatenated tree. The analysis of seven loci, acsA, aroE, guaA, mutL, nuoD, ppsA and trpE, demonstrated that the prevalent STs were ST-175, ST-235 and ST-253. The majority of the XDR and MDR isolates were included in ST-175 and ST-235. ST-253 is the third in frequency and included non-MDR isolates. The 26 singleton sequence types corresponded mainly to non-MDR isolates. Twenty-two isolates corresponded to new sequence types (not previously defined) of which 12 isolates were non-MDR and 10 isolates were MDR or XDR. Conclusions The population structure of clinical P. aeruginosa present in our hospital indicates the coexistence of nonresistant and resistant isolates with the same sequence type. The multiresistant isolates studied are grouped in the prevalent sequence types found in other Spanish hospitals and at the international level, and the susceptible isolates correspond mainly to singleton sequence types. PMID:23773707

  9. [Performance evaluation of VITEK 2 system in meropenem susceptibility testing of clinical Pseudomonas aeruginosa isolates].

    PubMed

    Acuner, Ibrahim Cağatay; Bayramoğlu, Gülçin; Birinci, Asuman; Cekiç Cihan, Ciğdem; Bek, Yüksel; Durupınar, Belma

    2011-07-01

    Pseudomonas aeruginosa is an important opportunistic pathogen associated with various community-acquired or nosocomial infections. Multi-drug resistant P.aeruginosa strains increasingly cause epidemics and spread in various hospital wards and geographic regions. Carbapenems are among the most effective antimicrobials in the treatment of multi-drug resistant P.aeruginosa infections, and meropenem is the most successful among alternatives in initial therapy. Particularly in severe infections, inappropriate or inadequate initial antimicrobial therapy is independently associated with adverse clinical and economic outcomes. Availability of accurate and rapid susceptibility testing is a priority. Most of the automated microbiology systems can provide rapid results within 8 to 12 hours. In comparison to standard methods, problems in the antimicrobial susceptibility testing of particular microorganisms and antimicrobial agents have been reported for automated microbiology systems. Failures have been reported previously especially in the susceptibility testing of P.aeruginosa versus carbapenem. Most of these studies are designed according to the Food and Drug Administration (FDA, USA) performance analysis scheme (Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test Systems) in a simplified form. However, there are many lacking issues in the design of most of these studies. Among these, insufficient sample size, use of inappropriate reference method, lack of reproducibility testing, and inadequate distribution of study isolates in interpretative categories are of notice. There are only few studies in the literature that evaluate the performance of automated systems in antimicrobial susceptibility testing of carbapenems in clinical P.aeruginosa isolates with a sufficient sample size (n ? 100). However, most of these studies still have one or more major deficiencies in the study design. Furthermore, none of these studies evaluate the performance of

  10. Emergence of NDM – 1 in the Clinical Isolates of Pseudomonas aeruginosa in India

    PubMed Central

    Khajuria, Atul; Praharaj, Ashok Kumar; Kumar, Mahadevan; Grover, Naveen

    2013-01-01

    Objective: The present study was undertaken to detect the prevalence of the blaNDM-1 metallo beta lactamases (MBLs) in the isolates of Pseudomonas aeruginosa, which were recovered from various clinical samples from hospitalized patients in a tertiary care centre in Pune, India. Methods: A total of 200 isolates of P. aeruginosa which were obtained from various clinical samples were subjected to antibiotic susceptibility testing by the disc-diffusion method and their MICs were determined by the Vitek – 2 Automated Antimicrobial Identification and Susceptibility Testing System against imipenem, meropenem, ticarcillin, amikacin, gentamicin, tobramycin, ciprofloxacin, levofloxacin, moxifloxacin, tigecycline, trimethoprim/sulfamethoxazole, ampicillin/sulbactam, piperacillin/tazobactam, cefoperazone/sulbactam, cefepime, tetracycline, ceftazidime, ceftriaxone and colistin. Their MICs were also determined by the Etest method against imipenem, meropenem, piperacillin, tobramycin, ceftazidime, tigecycline and colistin. The presence of blaNDM-1 was detected by PCR and it was confirmed by sequencing the gene which was present in the isolates which exhibited carbapenem resistance. The experimental transferability of the plasmids which carried blaNDM-1 was determined by using E. coli J53 as the recipient. Result: In the present study, four isolates of P. aeruginosa, which carried the blaNDM-1 gene, were resistant to imipenem and meropenem. These blaNDM-1 carrying isolates remained susceptible to colistin. The plasmid carrying blaNDM-1 was successfully transferred from the four isolates to E. coli J53 recipients. Conclusions: We are reporting the emergence of the P. aeruginosa carrying NDM-1gene, which exhibited resistance to imipenem and meropenem, for the first time from India. PMID:23998058

  11. Evaluating synergy between marbofloxacin and gentamicin in Pseudomonas aeruginosa strains isolated from dogs with otitis externa.

    PubMed

    Jerzsele, Ákos; Pásztiné-Gere, Erzsébet

    2015-03-01

    The aim of this study was to determine antimicrobial susceptibility of Pseudomonas aeruginosa strains to marbofloxacin and gentamicin, and investigate the possible synergistic, additive, indifferent or antagonistic effects between the two agents. P. aeruginosa strains can develop resistance quickly against certain antibiotics if used alone, thus the need emerges to find synergistic combinations. A total of 68 P. aeruginosa strains isolated from dogs were examined. In order to describe interactions between marbofloxacin and gentamicin the checkerboard microdilution method was utilized. The MICs (minimum inhibitory concentrations) for marbofloxacin and gentamicin were in the range 0.25-64 mg/L and 0.25-32 mg/L, respectively. The combination of marbofloxacin and gentamicin was more effective with a MIC range of 0.031-8 mg/L and a MIC90 of 1 mg/L, compared to 16 mg/L for marbofloxacin alone and 8 mg/L for gentamicin alone. The FIC (fractional inhibitory concentration) indices ranged from 0.0945 (pronounced synergy) to 1.0625 (indifference). Synergy between marbofloxacin and gentamicin was found in 33 isolates. The mean FIC index is 0.546, which represents a partial synergistic/additive effect close to the full synergy threshold. In vitro results indicate that marbofloxacin and gentamicin as partially synergistic agents may prove clinically useful in combination therapy against P. aeruginosa infections. Although marbofloxacin is not used in the human practice, the interactions between fluoroquinolones and aminoglycosides may have importance outside the veterinary field.

  12. Genetic features of Pseudomonas aeruginosa isolates from cystic fibrosis patients compared with those of isolates from other origins.

    PubMed

    Lanotte, Philippe; Watt, Stephane; Mereghetti, Laurent; Dartiguelongue, Nathalie; Rastegar-Lari, Aziz; Goudeau, Alain; Quentin, Roland

    2004-01-01

    In order to improve our understanding of the colonization of the pulmonary tract of cystic fibrosis (CF) patients by Pseudomonas aeruginosa, 162 isolates from five different ecological origins were studied. The genetic features of each isolate were determined by random amplification of polymorphic DNA (RAPD) and by searching for eight virulence genes (six known virulence genes, algD, lasB, toxA, plcH, plcN and exoS, and two genes encoding putative neuraminidases, nan1 and nan2). Five RAPD groups were identified. Most of the CF isolates were distributed equally in three of these groups (RA, RB and RC). The CF isolates in RB were related to isolates from a wide variety of origins. The CF isolates in RA were related to a population composed of 65 % of the non-CF isolates from pulmonary tract infections. RC was mainly composed of CF isolates that were related to 30 % of isolates from plants. All genes except exoS and nan1 were present in all isolates. The exoS and nan1 virulence factor genes were most prevalent in CF isolates. exoS, which encodes exoenzyme S, was present in 94 % of CF isolates but also in 80 % of non-CF isolates from pulmonary tract infections. nan1, which encodes a putative neuraminidase, was found in 82.5 % of the isolates from group RC, which was composed largely of CF isolates. In conclusion, three major genogroups of P. aeruginosa isolates, each of which exhibits peculiar genetic features, are able to colonize CF patients. This may have different consequences on the outcome of pulmonary disease.

  13. Carbapenem-resistant and cephalosporin-susceptible: a worrisome phenotype among Pseudomonas aeruginosa clinical isolates in Brazil.

    PubMed

    Campana, Eloiza Helena; Xavier, Danilo Elias; Petrolini, Fernanda Villas-Boas; Cordeiro-Moura, Jhonatha Rodrigo; Araujo, Maria Rita Elmor de; Gales, Ana Cristina

    The mechanisms involved in the uncommon resistance phenotype, carbapenem resistance and broad-spectrum cephalosporin susceptibility, were investigated in 25 Pseudomonas aeruginosa clinical isolates that exhibited this phenotype, which were recovered from three different hospitals located in São Paulo, Brazil. The antimicrobial susceptibility profile was determined by CLSI broth microdilution. β-lactamase-encoding genes were investigated by PCR followed by DNA sequencing. Carbapenem hydrolysis activity was investigated by spectrophotometer and MALDI-TOF assays. The mRNA transcription level of oprD was assessed by qRT-PCR and the outer membrane proteins profile was evaluated by SDS-PAGE. Genetic relationship among P. aeruginosa isolates was assessed by PFGE. Carbapenems hydrolysis was not detected by carbapenemase assay in the carbapenem-resistant and cephalosporin-susceptible P. aueruginosa clinical isolates. OprD decreased expression was observed in all P. aeruginosa isolates by qRT-PCR. The outer membrane protein profile by SDS-PAGE suggested a change in the expression of the 46kDa porin that could correspond to OprD porin. The isolates were clustered into 17 genotypes without predominance of a specific PFGE pattern. These results emphasize the involvement of multiple chromosomal mechanisms in carbapenem-resistance among clinical isolates of P. aeruginosa, alert for adaptation of P. aeruginosa clinical isolates under antimicrobial selective pressure and make aware of the emergence of an uncommon phenotype among P. aeruginosa clinical isolates.

  14. Prevalence, conservation and functional analysis of Yersinia and Escherichia CRISPR regions in clinical Pseudomonas aeruginosa isolates.

    PubMed

    Cady, K C; White, A S; Hammond, J H; Abendroth, M D; Karthikeyan, R S G; Lalitha, P; Zegans, M E; O'Toole, G A

    2011-02-01

    Here, we report the characterization of 122 Pseudomonas aeruginosa clinical isolates from three distinct geographical locations: Dartmouth Hitchcock Medical Center in New Hampshire, USA, the Charles T. Campbell Eye Microbiology Lab at the University of Pittsburgh Medical Center, USA, and the Aravind Eye Hospital in Madurai, India. We identified and located clustered regularly interspaced short palindromic repeats (CRISPR) in 45/122 clinical isolates and sequenced these CRISPR, finding that Yersinia subtype CRISPR regions (33 %) were more prevalent than the Escherichia CRISPR region subtype (6 %) in these P. aeruginosa clinical isolates. Further, we observed 132 unique spacers from these 45 CRISPR that are 100 % identical to prophages or sequenced temperate bacteriophage capable of becoming prophages. Most intriguingly, all of these 132 viral spacers matched to temperate bacteriophage/prophages capable of inserting into the host chromosome, but not to extrachromosomally replicating lytic P. aeruginosa bacteriophage. We next assessed the ability of the more prevalent Yersinia subtype CRISPR regions to mediate resistance to bacteriophage infection or lysogeny by deleting the entire CRISPR region from sequenced strain UCBPP-PA14 and six clinical isolates. We found no change in CRISPR-mediated resistance to bacteriophage infection or lysogeny rate even for CRISPR with spacers 100 % identical to a region of the infecting bacteriophage. Lastly, to show these CRISPR and cas genes were expressed and functional, we demonstrated production of small CRISPR RNAs. This work provides both the first examination to our knowledge of CRISPR regions within clinical P. aeruginosa isolates and a collection of defined CRISPR-positive and -negative strains for further CRISPR and cas gene studies.

  15. Colistin susceptibility testing: evaluation of reliability for cystic fibrosis isolates of Pseudomonas aeruginosa and Stenotrophomonas maltophilia

    PubMed Central

    Moskowitz, Samuel M.; Garber, Elizabeth; Chen, Yunhua; Clock, Sarah A.; Tabibi, Setareh; Miller, Amanda K.; Doctor, Michael; Saiman, Lisa

    2010-01-01

    Objectives Antibiotic susceptibility methods that are commonly used to test bacterial isolates from patients with cystic fibrosis are of uncertain reliability for the polymyxins. To assess the reliability of four standard testing methods, this pilot study used a challenge set that included polymyxin-resistant isolates of Pseudomonas aeruginosa and Stenotrophomonas maltophilia. Methods Twenty-five P. aeruginosa and 12 S. maltophilia isolates were tested for susceptibility to colistin (polymyxin E). Repeatability (concordance of replicates performed concurrently), reproducibility (concordance of replicates performed over time) and comparability (concordance of different methods) of agar dilution, broth microdilution, Etest and disc diffusion were assessed through the use of descriptive statistics and scatterplot analyses. Results All four methods displayed excellent repeatability (overall concordance rate of 99%). However, analysis of reproducibility revealed substantially lower rates of concordance (74% for agar dilution, 84% for broth microdilution and Etest, and 91% for disc diffusion). In addition, comparability to agar dilution of the three other methods was generally poor, with overall rates of very major error ranging from 12% for broth microdilution to 18% for Etest and disc diffusion. Conclusions Compared with agar dilution, other susceptibility testing methods give high rates of apparent false polymyxin susceptibility for cystic fibrosis isolates of P. aeruginosa and S. maltophilia. Prospective study of the correlation between in vitro susceptibility and clinical response is needed to clarify whether these discrepancies reflect oversensitivity of the agar dilution method or insensitivity of the other methods. PMID:20430789

  16. Environmentally Endemic Pseudomonas aeruginosa Strains with Mutations in lasR Are Associated with Increased Disease Severity in Corneal Ulcers

    PubMed Central

    Hammond, John H.; Hebert, Wesley P.; Naimie, Amanda; Ray, Kathryn; Van Gelder, Rachel D.; DiGiandomenico, Antonio; Lalitha, Prajna; Srinivasan, Muthiah; Acharya, Nisha R.; Lietman, Thomas; Hogan, Deborah A.

    2016-01-01

    ABSTRACT The Steroids for Corneal Ulcers Trial (SCUT) was a multicenter, international study of bacterial keratitis in which 101 Pseudomonas aeruginosa infections were treated. Twenty-two of 101 P. aeruginosa isolates collected had a colony morphology characteristic of a loss-of-function mutation in lasR, the gene encoding a quorum-sensing master regulator. Ulcers caused by these 22 strains were associated with larger areas of corneal opacification, worse vision, and a lower rate of vision recovery in response to treatment than ulcers caused by the other isolates. The lasR sequences from these isolates each contained one of three nonsynonymous substitutions, and these strains were deficient in production of LasR-regulated protease and rhamnolipids. Replacement of lasR with either of the two most common lasR alleles from the SCUT isolates was sufficient to decrease protease and rhamnolipid production in PA14. Loss of LasR function is associated with increased production of CupA fimbriae, and the LasR-defective isolates exhibited higher production of CupA fimbriae than LasR-intact isolates. Strains with the same lasR mutation were of the same multilocus sequence type, suggesting that LasR-deficient, environmental P. aeruginosa strains were endemic to the area, and infections caused by these strains were associated with worse patient outcomes in the SCUT study. (This study has been registered at ClinicalTrials.gov under registration no. NCT00324168.) IMPORTANCE The LasR transcription factor is an important regulator of quorum sensing in P. aeruginosa and positively controls multiple virulence-associated pathways. The emergence of strains with lasR loss-of-function alleles in chronic disease is well described and is thought to represent a specific adaptation to the host environment. However, the prevalence and virulence of these strains in acute infections remain unclear. This report describes observations revealing that lasR mutants were common among isolates from

  17. Isolation and characterization of gallium resistant Pseudomonas aeruginosa mutants.

    PubMed

    García-Contreras, Rodolfo; Lira-Silva, Elizabeth; Jasso-Chávez, Ricardo; Hernández-González, Ismael L; Maeda, Toshinari; Hashimoto, Takahiro; Boogerd, Fred C; Sheng, Lili; Wood, Thomas K; Moreno-Sánchez, Rafael

    2013-12-01

    Pseudomonas aeruginosa PA14 cells resistant to the novel antimicrobial gallium nitrate (Ga) were developed using transposon mutagenesis and by selecting spontaneous mutants. The mutants showing the highest growth in the presence of Ga were selected for further characterization. These mutants showed 4- to 12-fold higher Ga minimal inhibitory growth concentrations and a greater than 8-fold increase in the minimum biofilm eliminating Ga concentration. Both types of mutants produced Ga resistant biofilms whereas the formation of wild-type biofilms was strongly inhibited by Ga. The gene interrupted in the transposon mutant was hitA, which encodes a periplasmic iron binding protein that delivers Fe³⁺ to the HitB iron permease; complementation of the mutant with the hitA gene restored the Ga sensitivity. This hitA mutant showed a 14-fold decrease in Ga internalization versus the wild-type strain, indicating that the HitAB system is also involved in the Ga uptake. Ga uptake in the spontaneous mutant was also lower, although no mutations were found in the hitAB genes. Instead, this mutant harbored 64 non-silent mutations in several genes including those of the phenazine pyocyanin biosynthesis. The spontaneous mutant produced 2-fold higher pyocyanin basal levels than the wild-type; the addition of this phenazine to wild-type cultures protected them from the Ga bacteriostatic effect. The present data indicate that mutations affecting Ga transport and probably pyocyanin biosynthesis enable cells to develop resistance to Ga.

  18. Genetically and Phenotypically Distinct Pseudomonas aeruginosa Cystic Fibrosis Isolates Share a Core Proteomic Signature

    PubMed Central

    Penesyan, Anahit; Kumar, Sheemal S.; Kamath, Karthik; Shathili, Abdulrahman M.; Venkatakrishnan, Vignesh; Krisp, Christoph; Packer, Nicolle H.; Molloy, Mark P.; Paulsen, Ian T.

    2015-01-01

    The opportunistic pathogen Pseudomonas aeruginosa is among the main colonizers of the lungs of cystic fibrosis (CF) patients. We have isolated and sequenced several P. aeruginosa isolates from the sputum of CF patients and compared them with each other and with the model strain PAO1. Phenotypic analysis of CF isolates showed significant variability in colonization and virulence-related traits suggesting different strategies for adaptation to the CF lung. Genomic analysis indicated these strains shared a large set of core genes with the standard laboratory strain PAO1, and identified the genetic basis for some of the observed phenotypic differences. Proteomics revealed that in a conventional laboratory medium PAO1 expressed 827 proteins that were absent in the CF isolates while the CF isolates shared a distinctive signature set of 703 proteins not detected in PAO1. PAO1 expressed many transporters for the uptake of organic nutrients and relatively few biosynthetic pathways. Conversely, the CF isolates expressed a narrower range of transporters and a broader set of metabolic pathways for the biosynthesis of amino acids, carbohydrates, nucleotides and polyamines. The proteomic data suggests that in a common laboratory medium PAO1 may transport a diverse set of “ready-made” nutrients from the rich medium, whereas the CF isolates may only utilize a limited number of nutrients from the medium relying mainly on their own metabolism for synthesis of essential nutrients. These variations indicate significant differences between the metabolism and physiology of P. aeruginosa CF isolates and PAO1 that cannot be detected at the genome level alone. The widening gap between the increasing genomic data and the lack of phenotypic data means that researchers are increasingly reliant on extrapolating from genomic comparisons using experimentally characterized model organisms such as PAO1. While comparative genomics can provide valuable information, our data suggests that such

  19. Resistance of Pseudomonas aeruginosa Isolates to Hydrogel Contact Lens Disinfection Correlates with Cytotoxic Activity

    PubMed Central

    Lakkis, Carol; Fleiszig, Suzanne M. J.

    2001-01-01

    One of the most common pathogens in infection of hydrogel contact lens wearers is Pseudomonas aeruginosa, which can gain access to the eye via contamination of the lens, lens case, and lens care solutions. Only one strain per species is used in current regulatory testing for the marketing of chemical contact lens disinfectants. The aim of this study was to determine whether P. aeruginosa strains vary in their susceptibility to hydrogel contact lens disinfectants. A method for rapidly screening bacterial susceptibility to contact lens disinfectants was developed, based on measurement of the MIC. The susceptibility of 35 P. aeruginosa isolates to two chemical disinfectants was found to vary among strains. MICs ranged from 6.25 to 100% for both disinfectants at 37°C, and a number of strains were not inhibited by a 100% disinfectant concentration in the lens case environment at room temperature (22°C). Resistance to disinfection appeared to be an inherent rather than acquired trait, since some resistant strains had been isolated prior to the introduction of the disinfectants and some susceptible P. aeruginosa strains could not be made more resistant by repeated disinfectant exposure. A number of P. aeruginosa strains which were comparatively more resistant to short-term disinfectant exposure also demonstrated the ability to grow to levels above the initial inoculum in one chemical disinfectant after long-term (24 to 48 h) disinfectant exposure. Resistance was correlated with acute cytotoxic activity toward corneal epithelial cells and with exsA, which encodes a protein that regulates cytotoxicity via a complex type III secretion system. These results suggest that chemical disinfection solutions may select for contamination with cytotoxic strains. Further investigation of the mechanisms and factors responsible for resistance may also lead to strategies for reducing adverse responses to contact lens wear. PMID:11283074

  20. Host inflammatory responses to first isolation of Pseudomonas aeruginosa from sputum in cystic fibrosis.

    PubMed

    Elborn, J S; Cordon, S M; Shale, D J

    1993-05-01

    Pseudomonas aeruginosa infection of the respiratory tract in patients with cystic fibrosis is a major determinant of morbidity and mortality. However, it has been postulated that the earliest phase of colonization is not associated with injury. To test this hypothesis we determined the association of the first recorded isolation of P. aeruginosa from the sputum on circulating markers of the inflammatory response in 6 patients with cystic fibrosis. At this time circulating C-reactive protein was increased in all 6 and neutrophil elastase alpha 1-antitrypsin complex (elastase-complex) was increased in 5 patients compared with healthy controls. This inflammatory response was associated with a reduction in the FEV1 and FVC of all patients [FEV1, 1.42 +/- 0.87 L (mean +/- SD) at first isolation vs. 2.08 +/- 0.74 L before isolation; P < 0.05; FVC, 1.94 +/- 0.93 L vs. 2.87 +/- 1.01 L, P < 0.05]. At a median interval of 10 months, 5 patients had raised titres of positive IgG antibody to P. aeruginosa, indicating significant exposure to this organism. At this time, lung function had returned to preinfection levels, whilst 3 patients showed continuing features of an inflammatory response, and the group mean value for elastase-complex was raised. Our findings demonstrate that at the time of first isolation of P. aeruginosa from the sputum of patients with cystic fibrosis, there is a concomitant systemic host response and an acute deterioration of pulmonary function.

  1. Evaluation of efflux pumps gene expression in resistant Pseudomonas aeruginosa isolates in an Iranian referral hospital

    PubMed Central

    Pourakbari, Babak; Yaslianifard, Sahar; Yaslianifard, Somaye; Mahmoudi, Shima; Keshavarz-Valian, Sepideh; Mamishi, Setareh

    2016-01-01

    Background and Objectives: Pseudomonas aeruginosa (PA) is one of the most important causes of nosocomial infections and has an intrinsic resistance to many antibiotics. Among all the resistance-nodulation-division (RND) pumps of P. aeruginosa, MexAB-OprM is the first efflux pump found to target multiple classes of antibiotics. This study was aimed to evaluate the expression level of genes expressing MexAB-OprM in clinical isolates of P. aeruginosa. Materials and Methods: In this study, 45 P. aeruginosa strains were isolated from patients admitted to Children’s Medical Center Hospital, an Iranian referral hospital. Disk diffusion and Minimum Inhibitory Concentration (MIC) methods were used for determination of the patterns of resistance to antibiotics. Real-time PCR was used to investigate the expression level of genes of MexAB-OprM efflux pump. Results: Among 45 resistant PA isolates, the frequency of genes overexpression was as follows: MexA (n=25, 55.5%), MexB (n=24, 53.3%) and OprM (n=16, 35.5%). In addition, in 28 strains (62%) overexpression was observed in one of the studied three genes of MexAB-OprM efflux pump. Conclusion: In our study 28 isolates (62%) had increased expression level of efflux pumps genes, MexAB-OprM. Although the efflux pumps play important roles in increasing the resistance towards different antibiotics but the role of other agents and mechanisms in evolution of resistance should not be ignored. Since the concomitant overproduction of other Mex efflux systems might have additive effects on antibiotic resistance, the co-expressing of a multicomponent efflux pump is recommended. On the other hand, the concomitant overproduction of two Mex pumps might have additive effects on resistance to antibiotic. Therefore co-expressing of Mex efflux systems is recommended. PMID:28210464

  2. Mutational and acquired carbapenem resistance mechanisms in multidrug resistant Pseudomonas aeruginosa clinical isolates from Recife, Brazil.

    PubMed

    Cavalcanti, Felipe Lira de Sá; Mirones, Cristina Rodríguez; Paucar, Elena Román; Montes, Laura Álvarez; Leal-Balbino, Tereza Cristina; Morais, Marcia Maria Camargo de; Martínez-Martínez, Luis; Ocampo-Sosa, Alain Antonio

    2015-12-01

    An investigation was carried out into the genetic mechanisms responsible for multidrug resistance in nine carbapenem-resistant Pseudomonas aeruginosa isolates from different hospitals in Recife, Brazil. Susceptibility to antimicrobial agents was determined by broth microdilution. Polymerase chain reaction (PCR) was employed to detect the presence of genes encoding β-lactamases, aminoglycoside-modifying enzymes (AMEs), 16S rRNA methylases, integron-related genes and OprD. Expression of genes coding for efflux pumps and AmpC cephalosporinase were assessed by quantitative PCR. The outer membrane proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The blaSPM-1, blaKPC-2 and blaGES-1 genes were detected in P. aeruginosa isolates in addition to different AME genes. The loss of OprD in nine isolates was mainly due to frameshift mutations, premature stop codons and point mutations. An association of loss of OprD with the overexpression of MexAB-OprM and MexXY-OprM was observed in most isolates. Hyper-production of AmpC was also observed in three isolates. Clonal relationship of the isolates was determined by repetitive element palindromic-PCR and multilocus sequence typing. Our results show that the loss of OprD along with overexpression of efflux pumps and β-lactamase production were responsible for the multidrug resistance in the isolates analysed.

  3. Intraclonal genetic diversity amongst cystic fibrosis and keratitis isolates of Pseudomonas aeruginosa.

    PubMed

    Hall, Amanda J; Fothergill, Joanne L; Kaye, Stephen B; Neal, Timothy J; McNamara, Paul S; Southern, Kevin W; Winstanley, Craig

    2013-02-01

    Given the emergence of transmissible strains of Pseudomonas aeruginosa, such as the Liverpool epidemic strain (LES), in cystic fibrosis (CF) centres, it is important to carry out regular surveillance of isolates. In a survey of 22 P. aeruginosa isolates, each from a different CF patient identified as negative for LES in a paediatric centre in Liverpool, six (23 %) were identified as being the same clone type (clone D) using array-tube genotyping. Using a series of alternative genotyping approaches [PFGE, random amplification of polymorphic DNA (RAPD), variable number of tandem repeats (VNTR) and multilocus sequence typing (MLST)], the six CF clone D isolates and eight previously identified clone D isolates associated with infections leading to keratitis were compared. All but two of the clone D isolates (both keratitis-associated) were assigned by MLST to sequence type 235 and were highly similar using VNTR analysis. However, there was considerable variation found among the isolates when using PFGE or RAPD, highlighting the limitations of these methods. The discordance with respect to two of the isolates identified by array-tube genotyping as clone D, when using all the other typing methods, emphasizes the need to use more than one method for reliable identification of strains.

  4. Genetic Analysis of Pseudomonas aeruginosa Isolates from the Sputa of Australian Adult Cystic Fibrosis Patients

    PubMed Central

    Anthony, Mario; Rose, Barbara; Pegler, Mary Beard; Elkins, Mark; Service, Helen; Thamotharampillai, Keerthi; Watson, Jason; Robinson, Michael; Bye, Peter; Merlino, John; Harbour, Colin

    2002-01-01

    Genetic investigations were carried out with 50 phenotypically selected strains of Pseudomonas aeruginosa from 18 patients attending an Australian cystic fibrosis (CF) center. The isolates were analyzed by restriction fragment length polymorphism (RFLP) analysis by pulsed-field gel electrophoresis (PFGE). Phylogenetic analysis of the macrorestriction patterns showed rates of genetic similarity ranging from 76 to 100%; 24 (48%) of the strains from 11 patients had greater than 90% similarity. A dominant strain emerged: 15 isolates from seven patients had identical PFGE patterns, and 4 other isolates were very closely related. The 50 isolates were grouped into 21 pulsotypes on the basis of visual delineation of a three-band difference. Ten of the 18 (56%) patients were infected with clonal or subclonal strains. Sequence analysis of PCR products derived from the mucA gene showed 20 mutations, with the number of mutations in individual isolates ranging from 1 to 4; 19 of these changes are reported here for the first time. Potentially functional changes were found in 22 (44%) isolates. Eight changes (five transversions and three single base deletions) led to premature stop codons, providing support for the presence of mucA mutations as one pathway to mucoidy. There was a trend toward an association between the dominant strain and lack of potentially functional mucA mutations (P = 0.09 by the χ2 test) but no relationship between genotype and phenotype. This is the first study of genetic variation in P. aeruginosa isolates from adult Australian CF patients. The findings highlight the need for further investigations on the transmissibility of P. aeruginosa in CF patients. PMID:12149328

  5. Multilocus sequence typing analysis of Pseudomonas aeruginosa isolated from pet Chinese stripe-necked turtles (Ocadia sinensis)

    PubMed Central

    Wendt, Mitchell

    2016-01-01

    Our research sought to characterize the phylogeny of Pseudomonas aeruginosa isolated from pet Chinese stripe-necked turtles (Ocadia sinensis) to better understand its evolutionary relation to other isolates and increase understanding of a potential zoonotic pathogen transmitted through direct contact with pet turtles. Thirty-one Pseudomonas aeruginosa isolates were obtained from both immature and adult turtles sold in pet shops in Korea. To characterize the phylogenic position of Chinese stripe-necked turtle-borne P. aeruginosa relative to other strains, multilocus sequence typing (MLST) analysis was performed due to the accessibility and breadth of MLST databases. Seven housekeeping genes (acsA, aroE, guaA, mutL, nuoD, ppsA, and trpE) were sequenced and the results were compared with data from the MLST database. The genes were further used for phylogenetic analysis of P. aeruginosa using concatenated gene fragments. Both rooted and unrooted phylogenetic trees were generated. Eleven distinct sequence types were present within the isolates among which seven were new. Expanding an unrooted phylogenetic tree to include P. aeruginosa MLST sequences isolated from various other geographic locations and sources revealed a divergent cluster containing the majority of isolates obtained from turtles. This suggests that P. aeruginosa strains particularly well-adapted for inhabiting turtles occupy a distinct phylogenetic position. PMID:28053614

  6. Virulence Gene Profiles of Multidrug-Resistant Pseudomonas aeruginosa Isolated From Iranian Hospital Infections

    PubMed Central

    Fazeli, Nastaran; Momtaz, Hassan

    2014-01-01

    Background: The most common hospital-acquired pathogen is Pseudomonas aeruginosa. It is a multidrug resistant bacterium causing systemic infections. Objectives: The present study was carried out in order to investigate the distribution of virulence factors and antibiotic resistance properties of Pseudomonas aeruginosa isolated from various types of hospital infections in Iran. Patients and Methods: Two-hundred and seventeen human infection specimens were collected from Baqiyatallah and Payambaran hospitals in Tehran, Iran. The clinical samples were cultured immediately and samples positive for P. aeruginosa were analyzed for the presence of antibiotic resistance and bacterial virulence genes using PCR (polymerase chain reaction). Antimicrobial susceptibility testing was performed using disk diffusion methodology with Müeller–Hinton agar. Results: Fifty-eight out of 127 (45.66%) male infection specimens and 44 out of 90 (48.88%) female infection specimens harbored P. aeruginosa. Also, 65% (in male specimens) and 21% (in female specimens) of respiratory system infections were positive for P. aeruginosa, which was a high rate. The genes encoding exoenzyme S (67.64%) and phospholipases C (45.09%) were the most common virulence genes found among the strains. The incidences of various β-lactams encoding genes, including blaTEM, blaSHV, blaOXA, blaCTX-M, blaDHA, and blaVEB were 94.11%, 16.66%, 15.68%, 18.62%, 21.56%, and 17.64%, respectively. The most commonly detected fluoroquinolones encoding gene was gyrA (15. 68%). High resistance levels to penicillin (100%), tetracycline (90.19%), streptomycin (64.70%), and erythromycin (43.13%) were observed too. Conclusions: Our findings should raise awareness about antibiotic resistance in hospitalized patients in Iran. Clinicians should exercise caution in prescribing antibiotics, especially in cases of human infections. PMID:25763199

  7. Biofilm Formation and β-Lactamase Production in Burn Isolates of Pseudomonas aeruginosa

    PubMed Central

    Heydari, Samira; Eftekhar, Fereshteh

    2015-01-01

    Background: Pseudomonas aeruginosa is an important nosocomial pathogen characterized by its innate resistance to multiple antimicrobial agents. Plasmid-mediated drug resistance also occurs by the production of extended-spectrum β-lactamases (ESBL), metallo β-lactamases (MBL), and AmpC β-lactamases. Another important factor for establishment of chronic infections by P. aeruginosa is biofilm formation mediated by the psl gene cluster. Objectives: The aim of this study was to evaluate biofilm formation and presence of the pslA gene in burn isolates of P. aeruginosa as well as the association of antibiotic resistance, MBL, ESBL and AmpC β-lactamase production with biofilm formation among the isolates. Materials and Methods: Sixty-two burn isolates of P. aeruginosa were obtained from Shahid Motahari Hospital in Tehran from August to October 2011. Antibiotic susceptibility was determined by the disc diffusion assay. MBL, AmpC and ESBL production were screened using the double disc synergy test, AmpC disc test and combined disc diffusion assay, respectively. The potential to form biofilm was measured using the microtiter plate assay and pslA gene was detected using specific primers and PCR. Results: Biofilm formation was observed in 43.5% of the isolates, of which 66.7% produced strong and 33.3% formed weak biofilms. All biofilm-positive and 14.2% of biofilm-negative isolates harbored the pslA gene. MBL, AmpC and ESBL production were significantly higher in the biofilm-positive isolates (70.3%, 62.9% and 33.3%, respectively) compared to the biofilm-negative strains (31.4%, 34.2% and 20%, respectively). Overall, 19 isolates (30.6%) co-produced MBL and AmpC, among which the majority were biofilm-positive (63.1%). Finally, four isolates (6.4%) had all three enzymes, of which 3 (75%) produced biofilm. Conclusions: Biofilm formation (both strong and weak) strongly correlated with pslA gene carriage. Biofilm formation also correlated with MBL and AmpC

  8. Population structure and antimicrobial susceptibility of both nonpersistent and persistent Pseudomonas aeruginosa isolates recovered from cystic fibrosis patients.

    PubMed

    Fernández-Olmos, Ana; García-Castillo, María; Alba, José María; Morosini, María Isabel; Lamas, Adelaida; Romero, Beatriz; Galán, Juan Carlos; del Campo, Rosa; Cantón, Rafael

    2013-08-01

    Seventy-six Pseudomonas aeruginosa isolates recovered from chronically (n=18) and nonchronically (n=18) colonized cystic fibrosis (CF) patients (2002 to 2009) were grouped in separate polyclonal populations. International CF epidemic clones were not identified, but the high-risk clone ST274, also found circulating in Spanish hospitals, was present. Persistent isolates were more resistant to antibiotics than nonpersistent isolates.

  9. Population Structure and Antimicrobial Susceptibility of Both Nonpersistent and Persistent Pseudomonas aeruginosa Isolates Recovered from Cystic Fibrosis Patients

    PubMed Central

    Fernández-Olmos, Ana; García-Castillo, María; Alba, José María; Morosini, María Isabel; Lamas, Adelaida; Romero, Beatriz; Galán, Juan Carlos; del Campo, Rosa

    2013-01-01

    Seventy-six Pseudomonas aeruginosa isolates recovered from chronically (n = 18) and nonchronically (n = 18) colonized cystic fibrosis (CF) patients (2002 to 2009) were grouped in separate polyclonal populations. International CF epidemic clones were not identified, but the high-risk clone ST274, also found circulating in Spanish hospitals, was present. Persistent isolates were more resistant to antibiotics than nonpersistent isolates. PMID:23761158

  10. First Report of OXA-4, an ESBL Isolated from Pseudomonas aeruginosa a South Indian Strain.

    PubMed

    Kingsley, S A Jemima; Verghese, Susan

    2013-09-01

    The OXA-type β-lactamases are so named because of their oxacillin-hydrolyzing abilities. In this study we characterize an extended spectrum β-lactamase, designated OXA-4, produced by a clinical isolate of Pseudomonas aeruginosa. ESBL production was detected by double disk synergy test. The P. aeruginosa isolate was obtained from endotracheal suction tip of 84 years old male patient diagnosed with CVA and hypertension. ESBL producing OXA β-lactamases was detected by PCR with primers specific to the conserved regions of the coding genes. Iso electric focusing was done to confirm the significance, sequencing the amplified product was also done. In the phenotypic identification, the strain was highly resistant to third generation cephalosporins and also to imipenem. The PCR amplified product for OXA β-lactamase was viewed at 919 bp. The pI point for the same was identified at 7.2. With the help of sequencing the amplified OXA β-lactamase was identified as OXA-4 gene. Here we report P. aeruginosa producing OXA-4 ESBL for the first time in the Indian subcontinent.

  11. Optimisation of AP-PCR fingerprinting discriminatory power for clinical isolates of Pseudomonas aeruginosa.

    PubMed

    Dabrowski, Waldemar; Czekajlo-Kolodziej, Urszula; Medrala, Dagmara; Giedrys-Kalemba, Stefania

    2003-01-21

    Recently methods based on analysis of arbitrarily amplified target sites of microorganism genomes have been extensively applied in microbiological studies. The range of their applications is limited by problems with discrimination and reproducibility resulting from lack of standardised and reliable methods of optimisation. By orthogonal-array optimisation most advantageous and optimal parameters for highly discriminatory primers (CagA2+CMVin2) were selected and efficient AP-PCR (arbitrarily primed-polymerase chain reaction) fingerprinting conditions for Pseudomonas aeruginosa isolates were set up. Stable and multiplex amplicon profiles obtained in this study revealed high level of intraspecies DNA polymorphism among 20 analysed clinical strains of P. aeruginosa proving optimised AP-PCR fingerprinting to be useful in epidemiological typing of the species.

  12. Aloe vera Gel: Effective Therapeutic Agent against Multidrug-Resistant Pseudomonas aeruginosa Isolates Recovered from Burn Wound Infections.

    PubMed

    Goudarzi, Mehdi; Fazeli, Maryam; Azad, Mehdi; Seyedjavadi, Sima Sadat; Mousavi, Reza

    2015-01-01

    Objective. Aloe vera is an herbal medicinal plant with biological activities, such as antimicrobial, anticancer, anti-inflammatory, and antidiabetic ones, and immunomodulatory properties. The purpose of this study was investigation of in vitro antimicrobial activity of A. vera gel against multidrug-resistant (MDR) Pseudomonas aeruginosa isolated from patients with burn wound infections. Methods. During a 6-month study, 140 clinical isolates of P. aeruginosa were collected from patients admitted to the burn wards of a hospital in Tehran, Iran. Antimicrobial susceptibility test was carried out against the pathogens using the A. vera gel and antibiotics (imipenem, gentamicin, and ciprofloxacin). Results. The antibiogram revealed that 47 (33.6%) of all isolates were MDR P. aeruginosa. The extract isolated from A. vera has antibacterial activity against all of isolates. Also, 42 (89.4%) isolates were inhibited by A. vera gel extract at minimum inhibitory concentration (MIC) ≤ 200 µg/mL. MIC value of A. vera gel for other isolates (10.6%) was 800 µg/mL. All of MDR P. aeruginosa strains were inhibited by A. vera at similar MIC50 and MIC90 200 µg/mL. Conclusion. Based on our results, A. vera gel at various concentrations can be used as an effective antibacterial agent in order to prevent wound infection caused by P. aeruginosa.

  13. ISOLATION AND PRELIMINARY CHARACTERISTICS OF THREE BACTERIOPHAGES ASSOCIATED WITH A LYSOGENIC STRAIN OF PSEUDOMONAS AERUGINOSA, 12

    PubMed Central

    Feary, Thomas W.; Fisher, Earl; Fisher, Thelma N.

    1964-01-01

    Feary, Thomas W. (Tulane University School of Medicine, New Orleans, La.), Earl Fisher, Jr., and Thelma N. Fisher. Isolation and preliminary characteristics of three bacteriophages associated with a lysogenic strain of Pseudomonas aeruginosa. J. Bacteriol. 87:196–208. 1964.—Three bacteriophages designated 7v, 7m, and 7s were isolated from a lysogenic strain of Pseudomonas aeruginosa designated Ps-7. The three viruses were found to be completely unrelated on the basis of plaque morphology, host range, serology, ultraviolet induction, sensitivity to heat, and particle morphology as revealed by electron microscopy. In addition, it was shown that the three phages were incapable of plaque formation on bacteria other than various strains of P. aeruginosa. Of the three phages, only phage 7v was capable of plaque formation on strain Ps-7. The growth of phage 7v on strain Ps-7 exhibited properties which suggest that this virus arises as the result of mutation in a temperate phage for which strain Ps-7 is lysogenic. Phages 7m and 7s are incapable of plaque formation on strain Ps-7, but are adsorbed at characteristic rates to cell suspensions of strain Ps-7. The relationship between phage 7m and strain Ps-7 was shown to meet the classical criteria for lysogeny. Because phage 7s contains ribonucleic acid as its nucleic acid component, it was concluded that its production by strain Ps-7 and the demonstration of immunity of strain Ps-7 to infection by phage 7s were not sufficient evidence to define the nature of the relationship between phage 7s and P. aeruginosa strain Ps-7. It was observed that under certain conditions the infectious titer of phage 7s preparations are markedly reduced in the presence of ribonuclease. Images PMID:14102854

  14. Optimization of environmental factors for improved production of rhamnolipid biosurfactant by Pseudomonas aeruginosa RS29 on glycerol.

    PubMed

    Saikia, Rashmi Rekha; Deka, Suresh; Deka, Manab; Sarma, Hemen

    2012-08-01

    A biosurfactant producing Pseudomonas aeruginosa RS29 (identified on the basis of 16S rDNA analysis) with good foaming and emulsification properties has been isolated from crude oil contaminated sites. Optimization of different environmental factors was carried out with an objective to achieve maximum production of biosurfactant. Production of biosurfactant was estimated in terms of surface tension reduction and emulsification (E24) index. It was recorded that the isolated strain produced highest biosurfactant after 48 h of incubation at 37.5 °C, with a pH range of 7-8 and at salinity <0.8% (w/v). Ammonium nitrate used in the experiment was the best nitrogen source for the growth of biomass of P. aeruginosa RS29. On the other hand sodium and potassium nitrate enhanced the production of biosurfactant (Surface tension, 26.3 and 26.4 mN/m and E24 index, 80 and 79% respectively). The CMC of the biosurfactant was 90 mg/l. Maximum biomass (6.30 g/l) and biosurfactant production (0.80 g/l) were recorded at an optimal C/N ratio of 12.5. Biochemical analysis and FTIR spectra confirmed that the biosurfactant was rhamnolipid in nature. GC-MS analysis revealed the presence of C(8) and C(10) fatty acid components in the purified biosurfactant.

  15. Characterization of five newly isolated bacteriophages active against Pseudomonas aeruginosa clinical strains.

    PubMed

    Kwiatek, Magdalena; Mizak, Lidia; Parasion, Sylwia; Gryko, Romuald; Olender, Alina; Niemcewicz, Marcin

    2015-01-01

    Pseudomonas aeruginosa is an opportunistic pathogen that causes serious infections, especially in patients with immunodeficiency. It exhibits multiple mechanisms of resistance, including efflux pumps, antibiotic modifying enzymes and limited membrane permeability. The primary reason for the development of novel therapeutics for P. aeruginosa infections is the declining efficacy of conventional antibiotic therapy. These clinical problems caused a revitalization of interest in bacteriophages, which are highly specific and have very effective antibacterial activity as well as several other advantages over traditional antimicrobial agents. Above all, so far, no serious or irreversible side effects of phage therapy have been described. Five newly purified P. aeruginosa phages named vB_PaeM_WP1, vB_PaeM_WP2, vB_PaeM_WP3, vB_PaeM_WP4 and vB_PaeP_WP5 have been characterized as potential candidates for use in phage therapy. They are representatives of the Myoviridae and Podoviridae families. Their host range, genome size, structural proteins and stability in various physical and chemical conditions were tested. The results of these preliminary investigations indicate that the newly isolated bacteriophages may be considered for use in phagotherapy.

  16. Crataeva nurvala nanoparticles inhibit virulence factors and biofilm formation in clinical isolates of Pseudomonas aeruginosa.

    PubMed

    Ali, Syed Ghazanfar; Ansari, Mohammad Azam; Khan, Haris M; Jalal, Mohammad; Mahdi, Abbas Ali; Cameotra, Swaranjit Singh

    2017-03-01

    Green synthesized nanoparticles have gained great attention due to their non-toxic and non-hazardous nature. In the present study, bark extract of the medicinal plant in Ayurveda Crataeva nurvala (Buch-Ham) (CN) was chosen for the biosynthesis of silver nanoparticles (AgNPs). These NPs were characterized by Ultra violet visible spectroscopy, Fourier Transform Infra Red, Atomic Force Microscopy, and Transmission Electron Microscopy (TEM). The average particle size of green synthesized CN-AgNPs was 15.2 ± 1.01 nm. Gas chromatography- mass spectrometry analysis of methanolic bark extract involved in the formation of CN-AgNPs revealed lupeol as a major active component. In this study, CN-AgNPs (15 μg ml(-1) ) efficiently suppressed the production of quorum sensing mediated virulence factors viz. pyocyanin, protease, hemolysin, and biofilm formation in Pseudomonas aeruginosa. The pyocyanin production was strongly inhibited (74.64%) followed by proteolysis (47.3%) and hemolysin production (47.7%). However, the biofilm forming ability was maximally reduced up to 79.70%. Moreover, the Confocal Laser Scanning Microscopic Analysis showed that CN-AgNPs inhibit colonization of P. aeruginosa on to the surface. Furthermore, TEM analysis revealed internalization of CN-AgNPs inside the bacterial cell. It is concluded that green synthesized AgNPs have great potential to inhibit virulence factors and biofilm forming ability of drug-resistant clinical isolates of P. aeruginosa.

  17. Global regulatory pathways and cross-talk control pseudomonas aeruginosa environmental lifestyle and virulence phenotype.

    PubMed

    Coggan, Kimberly A; Wolfgang, Matthew C

    2012-01-01

    Pseudomonas aeruginosa is a metabolically versatile environmental bacterium and an opportunistic human pathogen that relies on numerous signaling pathways to sense, respond, and adapt to fluctuating environmental cues. Although the environmental signals sensed by these pathways are poorly understood, they are largely responsible for determining whether P. aeruginosa adopts a planktonic or sessile lifestyle. These environmental lifestyle extremes parallel the acute and chronic infection phenotypes observed in human disease. In this review, we focus on four major pathways (cAMP/Vfr and c-di-GMP signaling, quorum sensing, and the Gac/Rsm pathway) responsible for sensing and integrating external stimuli into coherent regulatory control at the transcriptional, translational, and post-translational level. A common theme among these pathways is the inverse control of factors involved in promoting motility and acute infection and those associated with biofilm formation and chronic infection. In many instances these regulatory pathways influence one another, forming a complex network allowing P. aeruginosa to assimilate numerous external signals into an integrated regulatory circuit that controls a lifestyle continuum.

  18. The isolation and characterization of lipopolysaccharides from Microcystis aeruginosa, a prominent toxic water bloom forming cyanobacteria.

    PubMed

    Bláhová, Lucie; Adamovský, Ondřej; Kubala, Lukáš; Švihálková Šindlerová, Lenka; Zounková, Radka; Bláha, Luděk

    2013-12-15

    Massive toxic blooms of cyanobacteria represent a major threat to water supplies worldwide, yet serious gaps exist in understanding their complex toxic effects, including the role of lipopolysaccharides (LPS). The present comparative study focused on the levels and biological activities of LPS isolated from Microcystis aeruginosa, which is one of the most globally distributed toxic species. Using hot phenol extraction, LPS was isolated from 3 laboratory cultures and 11 natural water blooms. It formed 0.2-0.7% of the original dry biomass of the cyanobacteria, based on gravimetry. Additional analyses by commercial anti-LPS ELISA were correlated with gravimetry but showed concentrations that were about 7-times lower, which indicated either impurities in isolated LPS or the poor cross-reactivity of the antibodies used. LPS isolates from M. aeruginosa were potent pyrogens in the traditional Limulus amebocyte lysate (LAL)-test, but comparison with the PyroGene test demonstrated the limited selectivity of LAL with several interferences. The determined pyrogenicity (endotoxin units, EU) ranged from very low values in laboratory cultures (less than 0.003 up to 0.008-EU per 100 pg LPS) to higher values in complex bloom samples (0.01-0.078 EU per 100 pg of LPS), which suggested the role of bloom-associated bacteria in the overall effects. Potent pro-inflammatory effects of the studied LPS from both cultures and bloom samples were observed in a highly-relevant ex vivo human blood model by studying reactive oxygen species production in phagocytes as well as increased productions of interleukin 8, IL-8, and tumor necrosis factor α, TNF-α. LPS from M. aeruginosa seem to modulate several pathways involved in the regulation of both innate immunity and specific responses. In comparison to the standard pathogenic bacterial LPS (World Health Organization Escherichia coli O113:10 endotoxin; activity 1 EU per 100 pg), the studied cyanobacterial samples had pyrogenicity potencies

  19. Decolorization of Distillery Spent Wash Using Biopolymer Synthesized by Pseudomonas aeruginosa Isolated from Tannery Effluent.

    PubMed

    David, Charles; Arivazhagan, M; Balamurali, M N; Shanmugarajan, Dhivya

    2015-01-01

    A bacterial strain was isolated from tannery effluent which can tolerate high concentrations of potassium dichromate up to 1000 ppm. The isolated microorganism was identified as Pseudomonas aeruginosa by performing biochemical tests and molecular characterization. In the presence of excess of carbohydrate source, which is a physiological stress, this strain produces Polyhydroxybutyrate (PHB). This intracellular polymer, which is synthesized, is primarily a product of carbon assimilation and is employed by microorganisms as an energy storage molecule to be metabolized when other common energy sources are limitedly available. Efforts were taken to check whether the PHB has any positive effect on spent wash decolorization. When a combination of PHB and the isolated bacterial culture was added to spent wash, a maximum color removal of 92.77% was found which was comparatively higher than the color removed when the spent wash was treated individually with the PHB and Pseudomonas aeruginosa. PHB behaved as a support material for the bacteria to bind to it and thus develops biofilm, which is one of the natural physiological growth forms of microorganisms. The bacterial growth in the biofilm and the polymer together acted in synergy, adsorbing and coagulating the pollutants in the form of color pigments.

  20. [Molecular typification of Pseudomonas aeruginosa strains isolated from patients with cystic fibrosis].

    PubMed

    Iglesias, N G; Marengo, J M; Rentería, F; Gatti, B; Segal, E; Semorile, L

    2008-01-01

    Cystic fibrosis is the most frequent lethal genetic disease that affects the caucasian population. The main cause of morbidity is the chronic lung infection, being the infection caused by Pseudomonas aeruginosa the most difficult to eradicate. This bacteria can be acquired in direct form, by person-to-person transfer, or indirectly, by hospital acquired infection. The Centro Provincial de Referencia de Fibrosis Quistica functioning in the Hospital de Niños "Sor María Ludovica", in La Plata, cares almost 220 patients aged two months to 45 years. The life expectancy depends of factors like the early diagnosis of the disease and the later acquisition of the chronic lung infection. The purpose of this work was the molecular typing of P. aeruginosa isolates obtained from cystic fibrosis patients to evaluate the genomic relationship among them. The study was carried out using RAPD-PCR. The analysis showed a great genetic heterogeneity among the isolates. The separation of the patients in groups in accordance with its bacteriology, that implies the attendance in different days and the implementation of isolation (or segregation) measures had demonstrated to be, in addition to other strategies, effective in the reduction of cross infections.

  1. Molecular characterization of carbapenem-resistant Pseudomonas aeruginosa strains isolated from patients with urinary tract infections in Southern Poland.

    PubMed

    Pobiega, Monika; Maciąg, Joanna; Chmielarczyk, Agnieszka; Romaniszyn, Dorota; Pomorska-Wesolowska, Monika; Ziolkowski, Grzegorz; Heczko, Piotr B; Bulanda, Malgorzata; Wojkowska-Mach, Jadwiga

    2015-11-01

    Due to the clinical threat posed by multidrug-resistant (MDR) Pseudomonas aeruginosa and importance of virulence factors produced in infection, 21 carbapenem-resistant P. aeruginosa were analyzed. 42.8% metallo-beta-lactamases-positive strains were identified. 85.7% of strains were meropenem resistant. 14.2% of strains were MDR; 38%, extensively drug-resistant (XDR). ExoY was present in all strains; exoT, in 95.2%; exoS, in 90.5%; exoU, in 47.6%. Eight XDR strains were typed using multilocus sequence typing: 4 as ST235, 2 as ST260, 2 as ST654 and ST234. MDR P. aeruginosa were isolated from hospitalized patients and among those from the community. Our study demonstrates the serious clinical issues posed by MDR P. aeruginosa and underscores the need for new treatment.

  2. [The comparison of selected virulence factors in Pseudomonas aeruginosa catheter isolates].

    PubMed

    Olejnízková, Katerina; Holá, Veronika

    2012-05-01

    Healthcare quality improvement brings about an increasing number of invasive diagnostic and therapeutic procedures and thus also an increasing number of high-risk patients prone to hospital infections. Pseudomonas aeruginosa is one of the most commonly isolated nosocomial species and the treatment of the infection is often long and problematic, with frequent recurrences. The pathogenesis of Pseudomonas infection is associated with a range of virulence factors. In the present study, 93 catheter isolates of Pseudomonas aeruginosa were screened for the biofilm formation, motility and secretion of selected extracellular products. A high rate of the strains tested were producers of hemolysins, LasB elastase, and pyoverdines (> 70%). The biofilm formation was detected in 80% of isolates and formation of aerated biofilm was present in 90% of isolates with a positive correlation found between the two types of biofilm formation (p = 0.00583; gamma = 0.551). All strains showed swarming motility, 95% of strains showed swimming motility, and 75% of strains showed twitching motility. Among the virulence factors studied, only pyocyanin and pyochelin were produced by a lower proportion of isolates (< 25%). A positive correlation was seen between the production of some extracellular molecules (pyochelin and pyocyanin, pyocyanin and LasB elastase, and LasB elastase and haemolysins), between biofilm formation and formation of aerated biofilm, and between formation of aerated biofilm and pigments (pyoverdine and pyocyanin) production. On the other hand, a negative correlation was found between biofilm production and LasB elastase production and between the production of biofilm under immersion and pigments (pyoverdine and pyocyanin) production. All correlations are significant at the level p = 0.05, with the correlation coefficient gamma > 0.50.

  3. LasR Variant Cystic Fibrosis Isolates Reveal an Adaptable Quorum-Sensing Hierarchy in Pseudomonas aeruginosa.

    PubMed

    Feltner, John B; Wolter, Daniel J; Pope, Christopher E; Groleau, Marie-Christine; Smalley, Nicole E; Greenberg, E Peter; Mayer-Hamblett, Nicole; Burns, Jane; Déziel, Eric; Hoffman, Lucas R; Dandekar, Ajai A

    2016-10-04

    Chronic Pseudomonas aeruginosa infections cause significant morbidity in patients with cystic fibrosis (CF). Over years to decades, P. aeruginosa adapts genetically as it establishes chronic lung infections. Nonsynonymous mutations in lasR, the quorum-sensing (QS) master regulator, are common in CF. In laboratory strains of P. aeruginosa, LasR activates transcription of dozens of genes, including that for another QS regulator, RhlR. Despite the frequency with which lasR coding variants have been reported to occur in P. aeruginosa CF isolates, little is known about their consequences for QS. We sequenced lasR from 2,583 P. aeruginosa CF isolates. The lasR sequences of 580 isolates (22%) coded for polypeptides that differed from the conserved LasR polypeptides of well-studied laboratory strains. This collection included 173 unique lasR coding variants, 116 of which were either missense or nonsense mutations. We studied 31 of these variants. About one-sixth of the variant LasR proteins were functional, including 3 with nonsense mutations, and in some LasR-null isolates, genes that are LasR dependent in laboratory strains were nonetheless expressed. Furthermore, about half of the LasR-null isolates retained RhlR activity. Therefore, in some CF isolates the QS hierarchy is altered such that RhlR quorum sensing is independent of LasR regulation. Our analysis challenges the view that QS-silent P. aeruginosa is selected during the course of a chronic CF lung infection. Rather, some lasR sequence variants retain functionality, and many employ an alternate QS strategy involving RhlR.

  4. LasR Variant Cystic Fibrosis Isolates Reveal an Adaptable Quorum-Sensing Hierarchy in Pseudomonas aeruginosa

    PubMed Central

    Feltner, John B.; Wolter, Daniel J.; Pope, Christopher E.; Groleau, Marie-Christine; Smalley, Nicole E.; Greenberg, E. Peter; Mayer-Hamblett, Nicole; Burns, Jane; Hoffman, Lucas R.

    2016-01-01

    ABSTRACT Chronic Pseudomonas aeruginosa infections cause significant morbidity in patients with cystic fibrosis (CF). Over years to decades, P. aeruginosa adapts genetically as it establishes chronic lung infections. Nonsynonymous mutations in lasR, the quorum-sensing (QS) master regulator, are common in CF. In laboratory strains of P. aeruginosa, LasR activates transcription of dozens of genes, including that for another QS regulator, RhlR. Despite the frequency with which lasR coding variants have been reported to occur in P. aeruginosa CF isolates, little is known about their consequences for QS. We sequenced lasR from 2,583 P. aeruginosa CF isolates. The lasR sequences of 580 isolates (22%) coded for polypeptides that differed from the conserved LasR polypeptides of well-studied laboratory strains. This collection included 173 unique lasR coding variants, 116 of which were either missense or nonsense mutations. We studied 31 of these variants. About one-sixth of the variant LasR proteins were functional, including 3 with nonsense mutations, and in some LasR-null isolates, genes that are LasR dependent in laboratory strains were nonetheless expressed. Furthermore, about half of the LasR-null isolates retained RhlR activity. Therefore, in some CF isolates the QS hierarchy is altered such that RhlR quorum sensing is independent of LasR regulation. Our analysis challenges the view that QS-silent P. aeruginosa is selected during the course of a chronic CF lung infection. Rather, some lasR sequence variants retain functionality, and many employ an alternate QS strategy involving RhlR. PMID:27703072

  5. Pseudomonas aeruginosa inhibits the growth of Scedosporium aurantiacum, an opportunistic fungal pathogen isolated from the lungs of cystic fibrosis patients

    PubMed Central

    Kaur, Jashanpreet; Pethani, Bhavin P.; Kumar, Sheemal; Kim, Minkyoung; Sunna, Anwar; Kautto, Liisa; Penesyan, Anahit; Paulsen, Ian T.; Nevalainen, Helena

    2015-01-01

    The filamentous fungus Scedosporium aurantiacum and the bacterium Pseudomonas aeruginosa are opportunistic pathogens isolated from lungs of the cystic fibrosis (CF) patients. P. aeruginosa has been known to suppress the growth of a number of CF related fungi such as Aspergillus fumigatus, Candida albicans, and Cryptococcus neoformans. However, the interactions between P. aeruginosa and S. aurantiacum have not been investigated in depth. Hence we assessed the effect of P. aeruginosa reference strain PAO1 and two clinical isolates PASS1 and PASS2 on the growth of two clinical S. aurantiacum isolates WM 06.482 and WM 08.202 using solid plate assays and liquid cultures, in a synthetic medium mimicking the nutrient condition in the CF sputum. Solid plate assays showed a clear inhibition of growth of both S. aurantiacum strains when cultured with P. aeruginosa strains PASS1 and PAO1. The inhibitory effect was confirmed by confocal microscopy. In addition to using chemical fluorescent stains, strains tagged with yfp (P. aeruginosa PASS1) and mCherry (S. aurantiacum WM 06.482) were created to facilitate detailed microscopic observations on strain interaction. To our knowledge, this is the first study describing successful genetic transformation of S. aurantiacum. Inhibition of growth was observed only in co-cultures of P. aeruginosa and S. aurantiacum; the cell fractions obtained from independent bacterial monocultures failed to initiate a response against the fungus. In the liquid co-cultures, biofilm forming P. aeruginosa strains PASS1 and PAO1 displayed higher inhibition of fungal growth when compared to PASS2. No change was observed in the inhibition pattern when direct cell contact between the bacterial and fungal strains was prevented using a separation membrane suggesting the involvement of extracellular metabolites in the fungal inhibition. However, one of the most commonly described bacterial virulence factors, pyocyanin, had no effect against either of the S

  6. Pseudomonas aeruginosa inhibits the growth of Scedosporium aurantiacum, an opportunistic fungal pathogen isolated from the lungs of cystic fibrosis patients.

    PubMed

    Kaur, Jashanpreet; Pethani, Bhavin P; Kumar, Sheemal; Kim, Minkyoung; Sunna, Anwar; Kautto, Liisa; Penesyan, Anahit; Paulsen, Ian T; Nevalainen, Helena

    2015-01-01

    The filamentous fungus Scedosporium aurantiacum and the bacterium Pseudomonas aeruginosa are opportunistic pathogens isolated from lungs of the cystic fibrosis (CF) patients. P. aeruginosa has been known to suppress the growth of a number of CF related fungi such as Aspergillus fumigatus, Candida albicans, and Cryptococcus neoformans. However, the interactions between P. aeruginosa and S. aurantiacum have not been investigated in depth. Hence we assessed the effect of P. aeruginosa reference strain PAO1 and two clinical isolates PASS1 and PASS2 on the growth of two clinical S. aurantiacum isolates WM 06.482 and WM 08.202 using solid plate assays and liquid cultures, in a synthetic medium mimicking the nutrient condition in the CF sputum. Solid plate assays showed a clear inhibition of growth of both S. aurantiacum strains when cultured with P. aeruginosa strains PASS1 and PAO1. The inhibitory effect was confirmed by confocal microscopy. In addition to using chemical fluorescent stains, strains tagged with yfp (P. aeruginosa PASS1) and mCherry (S. aurantiacum WM 06.482) were created to facilitate detailed microscopic observations on strain interaction. To our knowledge, this is the first study describing successful genetic transformation of S. aurantiacum. Inhibition of growth was observed only in co-cultures of P. aeruginosa and S. aurantiacum; the cell fractions obtained from independent bacterial monocultures failed to initiate a response against the fungus. In the liquid co-cultures, biofilm forming P. aeruginosa strains PASS1 and PAO1 displayed higher inhibition of fungal growth when compared to PASS2. No change was observed in the inhibition pattern when direct cell contact between the bacterial and fungal strains was prevented using a separation membrane suggesting the involvement of extracellular metabolites in the fungal inhibition. However, one of the most commonly described bacterial virulence factors, pyocyanin, had no effect against either of the S

  7. Isolation of the Autoinducer-Quenching Strain that Inhibits LasR in Pseudomonas aeruginosa

    PubMed Central

    Weng, Lixing; Zhang, Yuqian; Yang, Yuxiang; Wang, Lianhui

    2014-01-01

    Quorum sensing (QS) has been recognized as a general phenomenon in microorganisms and plays an important role in many pathogenic bacteria. In this report, we used the Agrobacterium tumefaciens biosensor strain NT1 to rapidly screen for autoinducer-quenching inhibitors from bacteria. After initial screening 5389 isolates obtained from land and beach soil, 53 putative positive strains were identified. A confirmatory bioassay was carried out after concentrating the putative positive culture supernatant, and 22 strains were confirmed to have anti-LasR activity. Finally, we determined the strain JM2, which could completely inhibit biofilm formation of Pseudomonas aeruginosa PAO1, belonged to the genus Pseudomonas by analysis of 16S rDNA. Partially purified inhibitor factor(s) F5 derived from culture supernatants specifically inhibited LasR-controlled elastase and protease in wild type P. aeruginosa PAO1 by 68% and 73%, respectively, without significantly affecting growth; the rhl-controlled pyocyanin and rhamnolipids were inhibited by 54% and 52% in the presence of 100 μg/mL of F5. The swarming motility and biofilm of PAO1 were also inhibited by F5. Real time RT-PCR on samples from 100 μg/mL F5-treated P. aeruginosa showed downregulation of autoinducer synthase (LasRI and rhlI) and cognate receptor (lasR and rhlR) genes by 50%, 28%, 48%, and 29%, respectively. These results provide compelling evidence that the F5 inhibitor(s) interferes with the las system and significantly inhibits biofilm formation. PMID:24736783

  8. Investigation of a Large Collection of Pseudomonas aeruginosa Bacteriophages Collected from a Single Environmental Source in Abidjan, Côte d’Ivoire

    PubMed Central

    Essoh, Christiane; Latino, Libera; Midoux, Cédric; Blouin, Yann; Loukou, Guillaume; Nguetta, Simon-Pierre A.; Lathro, Serge; Cablanmian, Arsher; Kouassi, Athanase K.; Vergnaud, Gilles; Pourcel, Christine

    2015-01-01

    Twenty two distinct bacteriophages were isolated from sewage water from five locations in the city of Abidjan, Côte d'Ivoire over a two-year period, using a collection of Pseudomonas aeruginosa strains with diverse genotypes. The phages were characterized by their virulence spectrum on a panel of selected P. aeruginosa strains from cystic fibrosis patients and by whole genome sequencing. Twelve virions representing the observed diversity were visualised by electron microscopy. The combined observations showed that 17 phages, distributed into seven genera, were virulent, and that five phages were related to temperate phages belonging to three genera. Some showed similarity with known phages only at the protein level. The vast majority of the genetic variations among virulent phages from the same genus resulted from seemingly non-random horizontal transfer events, inside a population of P. aeruginosa phages with limited diversity. This suggests the existence of a single environmental reservoir or ecotype in which continuous selection is taking place. In contrast, mostly point mutations were observed among phages potentially capable of lysogenisation. This is the first study of P. aeruginosa phage diversity in an African city and it shows that a large variety of phage species can be recovered in a limited geographical site at least when different bacterial strains are used. The relative temporal and spatial stability of the Abidjan phage population might reflect equilibrium in the microbial community from which they are released. PMID:26115051

  9. Distribution of Pseudomonas-Derived Cephalosporinase and Metallo-β-Lactamases in Carbapenem-Resistant Pseudomonas aeruginosa Isolates from Korea.

    PubMed

    Cho, Hye Hyun; Kwon, Gye Cheol; Kim, Semi; Koo, Sun Hoe

    2015-07-01

    The emergence of carbapenem resistance among Pseudomonas aeruginosa is an increasing problem in many parts of the world. In particular, metallo-β-lactamases (MBLs) and AmpC β- lactamases are responsible for high-level resistance to carbapenem and cephalosporin. We studied the diversity and frequency of β-lactamases and characterized chromosomal AmpC β- lactamase from carbapenem-resistant P. aeruginosa isolates. Sixty-one carbapenem-resistant P. aeruginosa isolates were collected from patients in a tertiary hospital in Daejeon, Korea, from January 2011 to June 2014. Minimum inhibitory concentrations (MICs) of four antimicrobial agents were determined using the agar-dilution method. Polymerase chain reaction and sequencing were used to identify the various β-lactamase genes, class 1 integrons, and chromosomally encoded and plasmid-mediated ampC genes. In addition, the epidemiological relationship was investigated by multilocus sequence typing. Among 61 carbapenem-resistant P. aeruginosa isolates, 25 isolates (41.0%) were MBL producers. Additionally, 30 isolates producing PDC (Pseudomonas-derived cephalosporinase)-2 were highly resistant to ceftazidime (MIC50 = 256 μg/ml) and cefepime (MIC50 = 256 μg/ml). Of all the PDC variants, 25 isolates harboring MBL genes showed high levels of cephalosporin and carbapenem resistance, whereas 36 isolates that did not harbor MBL genes revealed relatively low-level resistance (ceftazidime, p < 0.001; cefepime, p < 0.001; imipenem, p = 0.003; meropenem, p < 0.001). The coexistence of MBLs and AmpC β-lactamases suggests that these may be important contributing factors for cephalosporin and carbapenem resistance. Therefore, efficient detection and intervention to control drug resistance are necessary to prevent the emergence of P. aeruginosa possessing this combination of β-lactamases.

  10. Biofilm formation abilities and disinfectant-resistance of Pseudomonas aeruginosa isolated from cockroaches captured in hospitals.

    PubMed

    Saitou, Keiko; Furuhata, Katsunori; Kawakami, Yasushi; Fukuyama, Masafumi

    2009-06-01

    Forty-five strains of Pseudomonas aeruginosa isolated from cockroaches captured in hospitals were investigated with regard to their biofilm-forming ability and resistance to various disinfectants in various cellular states. The hydrophobicity value varied among the test strains from 0.001 to 0.241, and the mean +/- standard deviation (SD) was 0.101 +/- 0.074. The relative viscosity of the extracellular product was measured. All test strains produced a mucous substance, and the value was 1.05-1.30 (mean +/- SD: 1.11 +/- 0.06), showing that all test strains had a biofilm-forming ability. Bactericidal experiments were performed using 6 disinfectants: ethanol, Hibitane, Isojin, Osvan, Tego 51, and Welpas. When bacteria in suspension were exposed to the disinfectants for 1 min (suspension test), 5 of the 6 disinfectants excluding Tego 51 completely killed all test strains, showing high bactericidal effects. In contrast, when adherent bacteria were exposed to the disinfectants for 1 min (adhesion test), the killing rate by Welpas was 100%, but those by Isojin and ethanol were lower (88.9 and 60.0%, respectively), that by Osvan was only 4.4%, and no bacteria were killed by Hibitane or Tego 51. These findings showed that the bactericidal effects markedly decreased in the case of adherent P. aeruginosa.

  11. A thermo-stable lysine aminopeptidase from Pseudomonas aeruginosa: Isolation, purification, characterization, and sequence analysis.

    PubMed

    Wu, Yan Tao; Zhou, Nan Di; Zhou, Zhe Min; Gao, Xin Xing; Tian, Ya Ping

    2014-10-01

    Pseudomonas aeruginosa NJ-814, isolated from garden soil, produced an extracellular aminopeptidase that was purified using ammonium sulfate precipitation and ion exchange chromatography. The purity was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and the Mr value of the enzyme was estimated to be 55 kDa. The purified enzyme shows maximum activity at pH 9.0 and 80 °C. It exhibits high thermo-stability. Half of the activity can remain after incubation at 80 °C for 119 min. It is stable within pH range of 7.5-10.5. It is strongly activated by Co(2+) and inhibited by Fe(2+) , Cu(2+) , Ni(2+) , Zn(2+) , and ethylene diamine tetraacetic acid (EDTA). The specificity of the enzyme was investigated. Within several aminoacyl-p-nitroanilines (AA-pNA), Lys-pNA is proven to be the optimal substrate. The Michaelis-Menten constant (Km ) of the enzyme for Lys-pNA and Leu-pNA were 2.32 and 9.41 mM, respectively. Peptide map fingerprinting shows that the sequence of the enzyme is highly similar to aminopeptidase Y from P. aeruginosa 18A. It can be speculated that this enzyme is a Zn(2+) -dependent enzyme and contains two zinc ions in its active site.

  12. Effect of airway Pseudomonas aeruginosa isolation and infection on steady-state bronchiectasis in Guangzhou, China

    PubMed Central

    Guan, Wei-Jie; Gao, Yong-Hua; Xu, Gang; Lin, Zhi-Ya; Tang, Yan; Li, Hui-Min; Li, Zhi-Min; Zheng, Jin-Ping

    2015-01-01

    Background Current status of Pseudomonas aeruginosa (PA) infection in clinically stable bronchiectasis in mainland China remains unclear. Objective To compare the inflammation and lung function impairment in bronchiectasis patients isolated or infected with PA, potentially pathogenic microorganisms (PPMs) and commensals, and to identify factors associated with PA isolation and infection. Methods Patients with steady-state bronchiectasis and healthy subjects were recruited. Peripheral blood and sputum were sampled to determine inflammatory markers and bacterial loads in steady-state bronchiectasis and health. Spirometry and diffusing capacity were also measured. Results We enrolled 144 bronchiectasis patients and 23 healthy subjects. PA isolation and infection accounted for 44 and 39 patients, who demonstrated significant inflammatory responses and markedly impaired spirometry, but not diffusing capacity, compared with healthy subjects and patients isolated with other PPMs and commensals (all P<0.05). Except for heightened sputum inflammatory responses, there were no notable differences in serum inflammation and lung function as with the increased density of PA. Female gender [odds ratio (OR): 3.10 for PA isolation; OR: 3.74 for PA infection], 4 or more exacerbations within 2 years (OR: 3.74 for PA isolation, OR: 2.95 for PA infection) and cystic bronchiectasis (OR: 3.63 for PA isolation, OR: 4.47 for PA infection) were the factors consistently associated with PA isolation and infection. Conclusions PA elicits intense inflammation and lung function impairment in steady-state bronchiectasis. The density of PA does not correlate with most clinical indices. PA infection is associated with females, frequent exacerbations and cystic bronchiectasis. PMID:25973228

  13. Epidemiology and virulence of VIM-4 metallo-beta-lactamase-producing Pseudomonas aeruginosa isolated from burn patients in eastern Algeria.

    PubMed

    Meradji, Samah; Barguigua, Abouddihaj; Bentakouk, Mohamed Cherif; Nayme, Kaotar; Zerouali, Khalid; Mazouz, Dekhil; Chettibi, Houria; Timinouni, Mohammed

    2016-06-01

    In this study, we investigated the prevalence of carbapenem-resistant Pseudomonas aeruginosa (CRPA) in burn patients from eastern Algeria, CRPA virulence factors and the molecular epidemiology of CRPA. The overall prevalence of CRPA was 48.38%. Seven (46.66%) isolates were metallo-β-lactamases (MBL) producers and contained the MBL genes blaVIM-4 (n=6) and blaVIM-2 (n=1). Risk factors for CRPA infection were urinary catheter use and intubation (p=0.008). A high percentage of virulence factors (86.6% of these isolates were able to produce protease; 73.3% of isolates has DNase; and 66.6% were haemolysin positive) was observed in CRPA isolates. Among the seven MBL-producing isolates, four had the same clonal profile. The class 1 integrons, which contained the aadA7 gene cassette, were detected in six isolates. The 16SrRNA methylase gene, rmtB, was detected in one strain. All CRPA isolates were biofilm formers. A study on the kinetics of biofilm production revealed that biofilm production increased when the concentration of imipenem or ciprofloxacin and the incubation time increased. This is the first study to report the presence of VIM-4-producing P. aeruginosa from North Africa and also of the high prevalence of CRPA isolates. Based on our study of burn unit patients, the high percentage of P. aeruginosa with virulence factors and multi-drug resistance is alarming.

  14. Pseudomonas aeruginosa variants isolated from patients with cystic fibrosis are killed by a bactericidal protein from human polymorphonuclear leukocytes.

    PubMed Central

    Siefferman, C M; Regelmann, W E; Gray, B H

    1991-01-01

    The susceptibility of paired mucoid and nonmucoid variants of Pseudomonas aeruginosa isolated from 13 patients with cystic fibrosis (CF) to killing by a 55,000-Da bactericidal protein (BP55) from human polymorphonuclear leukocytes was studied. Mucoid and nonmucoid variants were equally sensitive to killing by BP55 at both pH 5.6 and pH 7.2. Eleven of the isolates were resistant to the bactericidal activity of 10% normal human serum but were as sensitive as the serum-sensitive isolates to BP55. Similarly, the 15 isolates with lipopolysaccharides (LPS) containing O-polysaccharide side chains (smooth LPS) were as sensitive to BP55 as those isolates with rough LPS.P. aeruginosa isolates from patients in poor clinical condition were more likely to have LPS of the smooth type and to be resistant to killing by 10% human serum than the isolates from patients in good clinical condition. We have concluded that the susceptibility of the P. aeruginosa isolates from patients with CF to killing by BP55 does not correlate with mucoid or nonmucoid variations, with the presence or absence of smooth LPS, or with the sensitivity or resistance to killing by normal human serum. Images PMID:1903774

  15. Aquatic environmental safety assessment and inhibition mechanism of chemicals for targeting Microcystis aeruginosa.

    PubMed

    Yu, Xiao-Bo; Hao, Kai; Ling, Fei; Wang, Gao-Xue

    2014-11-01

    Cyanobacteria are a diverse group of Gram-negative bacteria that produce an array of secondary compounds with selective bioactivity against vertebrates, invertebrates, fungi, bacteria and cell lines. Recently the main methods of controlling cyanobacteria are using chemicals, medicinal plants and microorganism but fewer involved the safety research in hydrophytic ecosystems. In search of an environmentally safe compound, 53 chemicals were screened against the developed heavy cyanobacteria bloom Microcystis aeruginosa using coexistence culture system assay. The results of the coexistence assay showed that 9 chemicals inhibited M. aeruginosa effectively at 20 mg L(-1) after 7 days of exposure. Among them dimethomorph, propineb, and paraquat were identified that they are safe for Chlorella vulgaris, Scenedesmus obliquus, Carassius auratus (Goldfish) and Bacillus subtilis within half maximal effective concentration (EC50) values 5.2, 4.2 and 0.06 mg L(-1) after 7 days, respectively. Paraquat as the positive control observed to be more efficient than the other compounds with the inhibitory rate (IR) of 92% at 0.5 mg L(-1). For the potential inhibition mechanism, the chemicals could destroy the cell ultrastructure in different speed. The safety assay proved dimethomorph, propineb and paraquat as harmless formulations or products having potential value in M. aeruginosa controlling, with the advantage of its cell morphology degrading ability.

  16. Exposure of Pseudomonas aeruginosa to green tea polyphenols enhances the tolerance to various environmental stresses.

    PubMed

    Liu, Xiaoxiang; Li, Jianrong; Yang, Yi; Chen, Xiaoqiang

    2012-12-01

    Green tea polyphenols (GTP) are widely used as food preservatives and are considered to be extremely safe. However, the bacterial response to GTP has not been well studied. Here we investigated whether short exposure of Pseudomonas aeruginosa to sub-lethal dose of GTP could lead to cross-resistance to some environmental stresses. One-hour exposure of P. aeruginosa to 1 mg/ml GTP significantly increased the tolerance to oxidants (2 mM H(2)O(2), 4 mM tert-butylhydroperoxide), low pH solution (pH 4.0) containing various organic acids (60 mM citric, acetic, propionic or lactic acid) and other stress conditions (47 °C, 25 % NaCl, 12 % ethanol and 150 μg/ml crystal violet). The development of H(2)O(2) tolerance in GTP-exposed cells was prevented by chloramphenicol, a well-known inhibitor of protein synthesis in prokaryotic cells. Furthermore, we observed significantly increased catalase activity after GTP exposure, suggesting that P. aeruginosa develops GTP-induced cross-resistance by increasing synthesis of protective protein. These observations raise concerns over the underlying risks associated with using GTP as food preservatives.

  17. Evaluation of Metallo-β-Lactamase-Production and Carriage of bla-VIM Genes in Pseudomonas aeruginosa Isolated from Burn Wound Infections in Isfahan

    PubMed Central

    Saffari, Mahmood; Firoozeh, Farzaneh; Pourbabaee, Mohammad; Zibaei, Mohammad

    2016-01-01

    Background Metallo-β-lactamase-production among Gram-negative bacteria, including Pseudomonas aeruginosa, has become a challenge for treatment of infections due to these resistant bacteria. Objectives The aim of the current study was to evaluate the metallo-β-lactamase-production and carriage of bla-VIM genes among carbapenem-resistant P. aeruginosa isolated from burn wound infections. Patients and Methods A cross-sectional study was conducted from September 2014 to July 2015. One hundred and fifty P. aeruginosa isolates were recovered from 600 patients with burn wound infections treated at Imam-Musa-Kazem Hospital in Isfahan city, Iran. Carbapenem-resistant P. aeruginosa isolates were screened by disk diffusion using CLSI guidelines. Metallo-β-lactamase-producing P. aeruginosa isolates were identified using an imipenem-EDTA double disk synergy test (EDTA-IMP DDST). For detection of MBL genes including bla-VIM-1 and bla-VIM-2, polymerase chain reaction (PCR) methods and sequencing were used. Results Among the 150 P. aeruginosa isolates, 144 (96%) were resistant to imipenem by the disk diffusion method, all of which were identified as metallo-β-lactamase-producing P. aeruginosa isolates by EDTA-IMP DDST. Twenty-seven (18%) and 8 (5.5%) MBL-producing P. aeruginosa isolates harbored bla-VIM-1 and bla-VIM-2 genes, respectively. Conclusions Our findings showed a high occurrence of metallo-β-lactamase production among P. aeruginosa isolates in burn patient infections in our region. Also, there are P. aeruginosa isolates carrying the bla-VIM-1 and bla-VIM-2 genes in Isfahan province. PMID:28144604

  18. Draft Genome Sequence of Pseudomonas aeruginosa Strain N002, Isolated from Crude Oil-Contaminated Soil from Geleky, Assam, India

    PubMed Central

    Roy, Abhjit Sarma; Baruah, Reshita; Gogoi, Dhrubajyoti; Borah, Maina

    2013-01-01

    Here, we report the draft genome sequence of crude oil-degrading Pseudomonas aeruginosa strain N002, isolated from a crude oil-polluted soil sample from Geleky, Assam, India. Multiple genes potentially involved in crude oil degradation were identified. PMID:23405324

  19. Draft Genome Sequence of Pseudomonas aeruginosa Strain Hex1T Isolated from Soils Contaminated with Used Lubricating Oil in Argentina

    PubMed Central

    Luján, Adela M.; Feliziani, Sofía

    2017-01-01

    ABSTRACT Pseudomonas aeruginosa Hex1T was isolated from soils contaminated with used lubricating oil from a garage in Córdoba, Argentina. This strain is capable of utilizing this pollutant as the sole carbon and energy source. Here, we present the 6.9-Mb draft genome sequence of Hex1T, which contains many heavy metal-resistance genes. PMID:28082504

  20. Carbapenem inactivation: a very affordable and highly specific method for phenotypic detection of carbapenemase-producing Pseudomonas aeruginosa isolates compared with other methods.

    PubMed

    Akhi, Mohammad Taghi; Khalili, Younes; Ghotaslou, Reza; Kafil, Hossein Samadi; Yousefi, Saber; Nagili, Behroz; Goli, Hamid Reza

    2016-07-22

    This investigation was undertaken to compare phenotypic and molecular methods for detection of carbapenemase-producing Pseudomonas aeruginosa. A total of 245 non-duplicated isolates of P. aeruginosa were collected from hospitalized patients. Disc diffusion method was used to identify carbapenem-resistant bacteria. Three phenotypic methods, including Modified Hodge Test (MHT), Modified Carba NP (MCNP) test and Carbapenem Inactivation Method (CIM) were used for investigation of carbapenemase production. In addition, polymerase chain reaction (PCR) was used to detect carbapenemase encoding genes. Of 245 P. aeruginosa isolates investigated, 121 isolates were carbapenem-resistant. Among carbapenem-resistant isolates, 40, 39 and 35 isolates exhibited positive results using MHT, MCNP test and CIM, respectively. PCR indicated the presence of carbapenemase genes in 35 of carbapenem-resistant isolates. MHT showed low sensitivity and specificity for carbapenemase detection among P. aeruginosa isolates in comparison to PCR. CIM was most affordable and highly specific than MCNP test compared with the molecular method.

  1. Growing Menace of Antibacterial Resistance in Clinical Isolates of Pseudomonas aeruginosa in Nepal: An Insight of Beta-Lactamase Production

    PubMed Central

    Dhital, Rabindra; Puri, Ram; Chaudhary, Niraj; Khatiwada, Suresh

    2016-01-01

    Introduction. Pseudomonas aeruginosa is the most frequently isolated organism as it acts as the opportunistic pathogen and can cause infections in immunosuppressed patients. The production of different types of beta-lactamases renders this organism resistant to many commonly used antimicrobials. Therefore, the aim of this study was to document the antibiotic resistance rate in Pseudomonas aeruginosa isolated from different clinical specimens. Methods. Pseudomonas aeruginosa recovered was identified by standard microbiological methods. Antibiotic susceptibility testing was performed by modified Kirby-Bauer disc diffusion method following Clinical and Laboratory Standard Institute (CLSI) guidelines and all the suspected isolates were tested for the production of ESBLs, MBLs, and AmpC. Results. Out of total (178) isolates, 83.1% were recovered from the inpatient department (IPD). Majority of the isolates mediated resistance towards the beta-lactam antibiotics, while nearly half of the isolates were resistant to ciprofloxacin. Most of the aminoglycosides used showed resistance rate up to 75% but amikacin proved to be better option. No resistance to polymyxin was observed. ESBLs, MBLs, and AmpC mediated resistance was seen in 33.1%, 30.9%, and 15.7% isolates, respectively. Conclusions. Antibiotic resistance rate and beta-lactamase mediated resistance were high. Thus, regular surveillance of drug resistance is of utmost importance. PMID:27642599

  2. Isolation and characterization of mutants defective in the cyanide-insensitive respiratory pathway of Pseudomonas aeruginosa.

    PubMed

    Cunningham, L; Williams, H D

    1995-01-01

    The branched respiratory chain of Pseudomonas aeruginosa contains at least two terminal oxidases which are active under normal physiological conditions. One of these, cytochrome co, is a cytochrome c oxidase which is completely inhibited by concentrations of the respiratory inhibitor potassium cyanide as low as 100 microM. The second oxidase, the cyanide-insensitive oxidase, is resistant to cyanide concentrations in excess of 1 mM as well as to sodium azide. In this work, we describe the isolation and characterization of a mutant of P. aeruginosa defective in cyanide-insensitive respiration. This insertion mutant was isolated with mini-D171 (a replication-defective derivative of the P. aeruginosa phage D3112) as a mutagen and by screening the resulting tetracycline-resistant transductants for the loss of ability to grow in the presence of 1 mM sodium azide. Polarographic studies on the NADH-mediated respiration rate of the mutant indicated an approximate 50% loss of activity, and titration of this activity against increasing cyanide concentrations gave a monophasic curve clearly showing the complete loss of cyanide-insensitive respiration. The mutated gene for a mutant affected in the cyanide-insensitive, oxidase-terminated respiratory pathway has been designated cio. We have complemented the azide-sensitive phenotype of this mutant with a wild-type copy of the gene by in vivo cloning with another mini-D element, mini-D386, carried on plasmid pADD386. The complemented cio mutant regained the ability to grow on medium containing 1 mM azide, titration of its NADH oxidase activity with cyanide gave a biphasic curve similar to that of the wild-type organism, and the respiration rate returned to normal levels. Spectral analysis of the cytochrome contents of the membranes of the wild type, the cio mutant, and the complemented mutant suggests that the cio mutant is not defective in any membrane-bound cytochromes and that the complementing gene does not encode a heme

  3. In Vitro Activity of Fosfomycin against a Collection of Clinical Pseudomonas aeruginosa Isolates from 16 Spanish Hospitals: Establishing the Validity of Standard Broth Microdilution as Susceptibility Testing Method

    PubMed Central

    Díez-Aguilar, María; del Campo, Rosa; García-Castillo, María; Zamora, Javier; Cantón, Rafael

    2013-01-01

    The broth microdilution method for fosfomycin and Pseudomonas aeruginosa was assessed and compared with the approved agar dilution method in 206 genetically unrelated P. aeruginosa clinical isolates. Essential agreement between the two methods was 84%, and categorical agreement was 89.3%. Additionally, Etest and disk diffusion assays were performed. Results validate broth microdilution as a reliable susceptibility testing method for fosfomycin against P. aeruginosa. Conversely, unacceptable concordance was established between Etest and disk diffusion results with agar dilution results. PMID:23939889

  4. Evaluate the Relationship Between Class 1 Integrons and Drug Resistance Genes in Clinical Isolates of Pseudomonas aeruginosa

    PubMed Central

    Hosseini, Seyed Mohammad Javad; Naeini, Niloofar Shoaee; Khaledi, Azad; Daymad, Seyede Fatemeh; Esmaeili, Davoud

    2016-01-01

    Background: The prevalence of resistant Pseudomonas aeruginosa isolates is increasing and it is considered as one of the major public health concerns in the world. The association between integrons and drug resistance has been proven and evidences suggest that integrons are coding and responsible for dissemination of antibiotic resistance among P. aeruginosa isolates. Objective: This study is aimed to evaluate the relationship between class 1 integrons and drug resistance genes in clinical isolates of P. aeruginosa from burn patients. Methods: 100 isolates of P. aeruginosa were collected from burn patients hospitalized in the skin ward of Shahid Motahari hospital and susceptibility testing was performed by disk diffusion method (Kirby-Bauer). Then DNA was extracted and PCR technique was performed for the detection of class 1 integrons and drug resistance genes. Then data was analyzed using SPSS software. Results: The most effective antibiotic was polymyxin B with sensitivity 100%, and the most resistance was observed to the ciprofloxacin (93%) and amikacin (67%), respectively. The maximum and lowest frequencies of drug resistance genes belonged to the aac (6 ') - 1, VEB-1 with prevalence rate 93% and 10%, respectively. The statistical Chi-square test did not find any significant correlation between class 1 integrons and drug resistance genes (p˃ 0.05). Conclusion: Although no significant correlation between class 1 integrons and drug resistance was observed, but the resistance rate to antibiotics tested among P. aeruginosa isolates was high. So, surveillance, optimization and strict consideration of antimicrobial use and control of infection are necessary. PMID:28077975

  5. Biofilm formation, antibiotic susceptibility and RAPD genotypes in Pseudomonas aeruginosa clinical strains isolated from single centre intensive care unit patients.

    PubMed

    Vaněrková, Martina; Mališová, Barbora; Kotásková, Iva; Holá, Veronika; Růžička, Filip; Freiberger, Tomáš

    2017-04-01

    The aim of this study was to analyse genotypes, antimicrobial susceptibility patterns and serotypes in Pseudomonas aeruginosa clinical strains, including the clonal dissemination of particular strains throughout various intensive care units in one medical centre. Using random amplified polymorphic DNA (RAPD-PCR) and P. aeruginosa antisera, 22 different genotypes and 8 serotypes were defined among 103 isolates from 48 patients. No direct association between P. aeruginosa strain genotypes and serotypes was observed. RAPD typing in strains with the same serotype revealed different genotypes and, on the contrary, most strains with a different serotype displayed the same amplification pattern. The resulting banding patterns showed a high degree of genetic heterogeneity among all isolates from the patients examined, suggesting a non-clonal relationship between isolates from these patients. A higher degree of antibiotic resistance and stronger biofilm production in common genotypes compared to rare ones and genetic homogeneity of the most resistant strains indicated the role of antibiotic pressure in acquiring resistant and more virulent strains in our hospital. In conclusion, genetic characterisation of P. aeruginosa strains using RAPD method was shown to be more accurate in epidemiological analyses than phenotyping.

  6. Determination of Acquired Resistance Profiles of Pseudomonas aeruginosa Isolates and Characterization of an Effective Bacteriocin-Like Inhibitory Substance (BLIS) Against These Isolates

    PubMed Central

    Shokri, Dariush; Rabbani Khorasgani, Mohammad; Zaghian, Saeideh; Fatemi, Seyed Masih; Mohkam, Milad; Ghasemi, Younes; Taheri-Kafrani, Asghar

    2016-01-01

    Background The emergence of pan-drug resistant strains (PDR) of Pseudomonas aeruginosa has led to renewed efforts to identify alternative agents, such as bacteriocins and bacteriocin-like inhibitory substances (BLISs). Objectives The aims of this study were to determine the acquired resistance profiles of multidrug-resistant (MDR), extensively drug-resistant (XDR), and PDR P. aeruginosa isolates based on the revised definitions of the CDC and ECDC and to screen and characterize effective BLISs against these isolates. Patients and Materials In a cross-sectional study, 96 P. aeruginosa strains were isolated during a 12-month period. The resistance profiles of these isolates were determined as MDR, XDR, and PDR, and the data were analyzed using WHONET5.6 software. A BLIS against the P. aeruginosa strains was characterized based on its physicochemical properties, size, growth curves, and production profiles. Results Among the 96 isolates of P. aeruginosa, 2 (2.1%), 94 (97.9%), and 63 (65.6%) were non-MDR, MDR, and XDR, respectively, and 1 (1.1%) was PDR. The most effective antibiotics against these isolates were polymyxins and fosfomycin. A BLIS isolated from the P. aeruginosa DSH22 strain had potent activity against 92 (95.8%) of the 96 isolates. The BLIS was heat stable, (up to 100°C for 10 min), UV stable, and active within a pH range of 3 - 9. The activity of BLIS disappeared when treated with trypsin, proteinase K, and pepsin, indicating its proteinous nature. Based on its size (25 kDa), the BLIS may belong to the large colicin-like bacteriocin family. BLIS production started in the midexponential phase of growth, and the maximum level (2700 AU/mL) occurred in the late-stationary phase after 25 hours of incubation at 30°C. Conclusions This BLIS with broad-spectrum activity may be a potential agent for the treatment or control of drug-resistant strains of P. aeruginosa infection. PMID:27800131

  7. Effects of fertilizer-urea on growth, photosynthetic activity and microcystins production of Microcystis aeruginosa isolated from Dianchi Lake.

    PubMed

    Huang, Wenmin; Bi, Yonghong; Hu, Zhengyu

    2014-05-01

    Urea is the most frequently applied nitrogen (N) fertilizer in agriculture, while its loss is assumed triggering algal blooms in adjacent water bodies. In this context the present study assessed the growth, photosynthetic activity as well as toxin production of Microcystis aeruginosa at different urea concentrations (0.125, 1.25, 12.5, 250 and 2,500 mg/L) using BG11 (containing 250 mg/L NO3(-)-N) as control. The results showed for all endpoints that M. aeruginosa is capable of using urea as N source: the two highest urea treatments delivered comparable values like the control. Low urea concentrations (0.125 and 1.25 mg/L), which were comparable to environmental urea levels, did not sustainably promote the growth, photosynthesis and toxin production of the test species. While, in certain microenvironments urea might potentially reach the concentrations that may affect M. aeruginosa.

  8. Isolation and identification of a novel, lipase-producing bacterium, Pseudomnas aeruginosa KM110

    PubMed Central

    Mobarak-Qamsari, E; Kasra-Kermanshahi, R; Moosavi-nejad, Z

    2011-01-01

    Background and Objectives Lipases are particularly important due to the fact that they specifically hydrolyze acyl glycerol, oils and greases, which is of great interest for different industrial applications. Materialst and Methods In this study, several lipase-producing bacteria were isolated from wastewater of an oil processing plant. The strain possessing the highest lipase activity was identified both biochemically and sequencing of 16S rRNA gene. Then we increase lipase activity by improving conditions of production medium. Also, lipase from this strain was preliminarily characterized for use in industrial application. Results The 16S rRNA sequensing revealed it as a new strain of Pseudomonas aeruginosa and the type strain was KM110. An overall 3-fold enhanced lipase production (0.76 U mL−1) was achieved after improving conditions of production medium. The olive oil and peptone was found to be the most suitable substrate for maximum enzyme production. Also the enzyme exhibited maximum lipolytic activity at 45°C where it was also stably maintained. At pH 8.0, the lipase had the highest stability but no activity. It was active over a pH range of 7.0–10.0. The lipase activity was inhibited by Zn2+ & Cu2+ (32 and 27%, respectively) at 1mM. The enzyme lost 29% of its initial activity in 1.0% SDS concentration, whereas, Triton X-100, Tween-80 & DMSO did not significantly inhibit lipase activity. Conclusions Based on the findings of present study, lipase of P. aeruginosa KM110 is a potential alkaline lipase and a candidate for industrial applications such as detergent, leather and fine chemical industries. PMID:22347589

  9. Effects of glyphosate at environmentally relevant concentrations on the growth of and microcystin production by Microcystis aeruginosa.

    PubMed

    Zhang, Quan; Zhou, Hang; Li, Zhe; Zhu, Jianqiang; Zhou, Cong; Zhao, Meirong

    2016-11-01

    The use of glyphosate, which is a well-known sterilant herbicide, has been growing rapidly because the area under the cultivation of genetically modified crops that are tolerant to this herbicide has increased. Glyphosate can enter into aquatic systems through many different ways. However, information on the potential risks of glyphosate at environmentally relevant levels to aquatic systems is still limited. In this study, we selected the cyanobacterium Microcystis aeruginosa FACHB-905 (M. aeruginosa) as a model organism to evaluate the effects of glyphosate at environmentally relevant concentrations on the former's growth and microcystin (MC) production. Our results show that low levels of glyphosate stimulate the growth of M. aeruginosa. Subsequently, there was significant increase in the total MC-LR and intracellular MC-LR, but not in extracellular MC-LR, after exposure to 0.1-2 mg/L of glyphosate. The increase in total MC-LR is mainly due to the effects of glyphosate on the cell density of M. aeruginosa. The data provided here show that low level of glyphosate in a water body is a potential environmental risk factor that stimulates the growth and enhances MC production in M. aeruginosa, which should arouse great concern.

  10. Detection of Pseudomonas aeruginosa from clinical and environmental samples by amplification of the exotoxin A gene using PCR.

    PubMed Central

    Khan, A A; Cerniglia, C E

    1994-01-01

    PCR was used to detect Pseudomonas aeruginosa from water samples by amplifying a 396-bp region of the exotoxin A (ETA) structural gene sequence. The identify of the amplified 396-bp fragment was confirmed by digesting it with PvuI restriction endonuclease, which produced the predicted 246- and 150-bp fragments. Specific primers amplified ETA-positive P. aeruginosa DNA, whereas other species of Pseudomonas and GC-rich bacteria did not yield any 396-bp fragment. The specificity and sensitivity of the assay were 100 and 96%, respectively, which confirms the assay's reliability for diagnostic and epidemiological studies. The assay can detect as few as 5 to 10 cells in a 10-ml water sample or 0.1 pg of P. aeruginosa DNA per reaction mixture (5 microliters) by ethidium bromide staining of an agarose gel. Ten-times-lower concentrations were detected by hybridization with a digoxigenin-labeled oligonucleotide probe internal to the PCR product. With this PCR method, ETA-positive P. aeruginosa was detected in animal cage water samples at a level of 40 cells per ml. This method is rapid and less cumbersome than other diagnostic methods for the identification of P. aeruginosa strains. The method described can be used to detect a low level of P. aeruginosa from environmental and clinical samples without the use of selective media or additional biochemical tests. Images PMID:7986047

  11. A gacS Deletion in Pseudomonas aeruginosa Cystic Fibrosis Isolate CHA Shapes Its Virulence

    PubMed Central

    Sall, Khady Mayebine; Casabona, Maria Guillermina; Bordi, Christophe; Huber, Philippe; de Bentzmann, Sophie; Attrée, Ina; Elsen, Sylvie

    2014-01-01

    Pseudomonas aeruginosa, a human opportunistic pathogen, is capable of provoking acute and chronic infections that are associated with defined sets of virulence factors. During chronic infections, the bacterium accumulates mutations that silence some and activate other genes. Here we show that the cystic fibrosis isolate CHA exhibits a unique virulence phenotype featuring a mucoid morphology, an active Type III Secretion System (T3SS, hallmark of acute infections), and no Type VI Secretion System (H1-T6SS). This virulence profile is due to a 426 bp deletion in the 3′ end of the gacS gene encoding an essential regulatory protein. The absence of GacS disturbs the Gac/Rsm pathway leading to depletion of the small regulatory RNAs RsmY/RsmZ and, in consequence, to expression of T3SS, while switching off the expression of H1-T6SS and Pel polysaccharides. The CHA isolate also exhibits full ability to swim and twitch, due to active flagellum and Type IVa pili. Thus, unlike the classical scheme of balance between virulence factors, clinical strains may adapt to a local niche by expressing both alginate exopolysaccharide, a hallmark of membrane stress that protects from antibiotic action, host defences and phagocytosis, and efficient T3S machinery that is considered as an aggressive virulence factor. PMID:24780952

  12. Centrifugal partition chromatography: A preparative tool for isolation and purification of xylindein from Chlorociboria aeruginosa.

    PubMed

    Boonloed, Anukul; Weber, Genevieve L; Ramzy, Kelly M; Dias, Veronica R; Remcho, Vincent T

    2016-12-23

    A centrifugal partition chromatography (CPC) method was developed for the preparative-scale isolation and purification of xylindein from the wood-staining fungi, Chlorociboria aeruginosa. Xylindein, a blue-green pigment naturally secreted from the hyphae and fruiting bodies of the fungus, has great value in the decorative wood industry and textile coloration. Xylindein has great potential for use as a fluorescent labeling agent as well as in organic semiconductor applications. However, a primary limitation of xylindein is its poor solubility in most common HPLC solvents. Consequently, it is arduous to purify using preparative liquid chromatography or solid-phase extraction (SPE). Support-free, liquid-liquid chromatographic methods, including CPC, where solutes are separated based on their different distribution coefficients (KD) between two immiscible solvent systems, are promising alternatives for the purification of the compound on a preparative scale. In this work, a new biphasic solvent system suitable for CPC separation of xylindein was developed. Various groups of solvents were assessed for their suitability as xylindein extractants. A new solvent system suitable for CPC separation of xylindein, composed of heptane/THF/MEK/acetonitrile/acetic acid/water, was developed. This solvent system yielded a KD value for xylindein of 1.54±0.04, as determined by HPLC (n=3). The compositions of the upper phase and lower phase of the solvent system were determined by Heteronuclear Single Quantum Correlation (HSQC) NMR and proton NMR. A CPC system, equipped with a fraction collector, was used for the isolation of xylindein from crude extracts. The xylindein fractions isolated by the CPC were then analyzed using HPLC and presented as a fractogram. Based on the CPC fractogram, the purified xylindein fractions were achieved after 30min CPC separation time, yielding 71% extraction efficiency. The developed CPC method allowed for isolation of this naturally sourced xylindein

  13. Common antimicrobial resistance patterns, biotypes and serotypes found among Pseudomonas aeruginosa isolates from patient's stools and drinking water sources in Jordan.

    PubMed

    Shehabi, A A; Masoud, H; Maslamani, F A Balkam

    2005-04-01

    Pseudomonas aeruginosa was isolated in low rates from stool specimens of outpatients and inpatients (7% versus 12%) but in higher rates from chlorinated and nonchlorinated water sources (15% versus 44%), respectively in Jordan. The same biotype was recognized among 90% of P. aeruginosa isolates from patient's stools and water sources using specific biochemical profiles. Three serogroups belonging to 01, 06 and 011 accounted for the majority of these isolates in water (66%) and stools (78%), respectively. All P. aeruginosa isolates from water were highly susceptible (87%-100%) to piperacillin-tazobactam, amikacin, gentamicin, imipenem, aztreonam, ceftazidime and ciprofloxacin, whereas the isolates from stool were slightly less susceptible (81%-98%) to these antimicrobials. P. aeruginosa isolates from water and stool sources were almost equally highly resistant to tetracycline (86%-89%) and carbenicillin (88%-89%), respectively. One common small plasmid (15.4 kb) was detected in 14/25 (56%) of multidrug-resistant P. aeruginosa isolates from both water and stool. This study demonstrates certain common epidemiological characteristics including antimicrobial resistance pattern, biotypes and serotypes among P. aeruginosa isolates from patient's stools and drinking water sources in Jordan.

  14. Detection of Multidrug Resistant (MDR) and Extremely Drug Resistant (XDR) P. Aeruginosa Isolated from Patients in Tehran, Iran

    PubMed Central

    Saderi, Horieh; Owlia, Parviz

    2015-01-01

    Background: This study was done to detect multidrug resistant (MDR) and extremely drug resistant (XDR) of Pseudomonas aeruginosa among strains isolated from patients in Tehran, Iran, due to importance of these phenotypes in treatment of human infections. Methods: Eighty eight P. aeruginosa were isolated from patients in Tehran, Iran, and identified by routine methods and PCR for oprL gene. Their antimicrobial susceptibility to 16 antimicrobial agents from 7 antimicrobial categories (aminoglycosides, carbapenems, cephalosporins, fluoroquinolones, penicillins/ß-lactamase inhibitors, monobactams, polymyxins) were determined by disk diffusion method, according to recommendation of Clinical and Laboratory Standards Institute. Characterization of P. aeruginosa isolates as MDR and XDR was done according to standardized international terminology presented by European Centre for Disease Prevention and Control as well as the Centers for Disease Control and Prevention in 2011. MDR was defined as acquired non-susceptibility to at least one agent in ≥3 antimicrobial categories and XDR was defined as non-susceptibility to at least one agent in ≥6 antimicrobial categories. Results: The rates of susceptibility to antimicrobials were as follows: gentamicin 27.3%, tobramycin 54.5%, amikacin 56.8%, netilmicin 36.4%, imipenem 55.7%, meropenem 55.7%, doripenem 60.2%, ceftazidime 63.6%, cefepime 56.8%, ciprofloxacin 59.1%, levofloxacin 60.2%, ticarcillin-clavulanic acid 37.5%, piperacillin-tazobactam 63.6%, aztreonam 43.2%, colistin 90.9%, polymyxin 95.5%. Altogether, 48 (54.5%) and 29 (33%) isolates were characterized as MDR and XDR, respectively. Discussion: The high frequency of antibiotic resistance in clinical isolates of P. aeruginosa in Iran makes epidemiological surveillance of susceptibility of this bacterium more essential for the best selection of empirical antibiotics. PMID:26351496

  15. [Morphologic, cultural, and biochemical properties of cultures of Pseudomonas aeruginosa isolated from patients, animals, and the environment].

    PubMed

    Litovchenko, P P; Zabotina, I V

    1981-05-01

    The properties of 279 Ps. aeruginosa strains were studied in 70 tests. The use of a synthetic peptone-free mineral medium for the determination of sugar oxidation was shown to have advantages over the use of liquid Giess' media. Ps. aeruginosa cultures isolated from human patients, animals, soil and water were characterized by a number of common signs, irrespective of their origin. The strains isolated from human patients were resistant practically to all antibiotics widely used in clinical practice; the cultures isolated from soil and water retained their sensitivity to antibiotics; the strains isolated from animals retained sensitivity to some antibiotics. To identify Ps. aeruginosa in practical bacteriological laboratories, the following parameters should be determined: mobility; the character of growth in Levine's and Ploskirev's media; ability to grow at 42 degrees C and 4 degrees C; the fermentation of carbohydrates in Olkenitsky's medium and their oxidation in a mineral medium; indole and hydroxide sulfide production; the methyl red and Voges--Proskauer reaction; the presence of pigments, oxidase, catalase, gelatinase, nitrate reductase and arginine dehydrolase, urease; resistance to antibiotics.

  16. [Detection of metallo-beta-lactamase in Pseudomonas aeruginosa isolated from hospitalized patients in Goiânia, State of Goiás].

    PubMed

    Gonçalves, Diana Christina Pereira Santos; Lima, Ana Beatriz Mori; Leão, Lara Stefania Netto de Oliveira; Filho, José Rodrigues do Carmo; Pimenta, Fabiana Cristina; Vieira, José Daniel Gonçalves

    2009-01-01

    Pseudomonas aeruginosa is a bacterium frequently isolated from hospital environments. This study had the aims of evaluating the susceptibility profile of Pseudomonas aeruginosa previously isolated from patients in a hospital in Goiânia (Goiás, Brazil), performing phenotypic screening for metallo-beta-lactamase production and detecting its genes using the polymerase chain reaction technique. Seventy-five 75 Pseudomonas aeruginosa isolates were evaluated between January 2005 and January 2007. Biochemical identification was performed using the API 20E system and an antibiogram was produced using the Kirby-Bauer method. Among the 62 isolates that were resistant to imipenem and ceftazidime, 35 (56.4%) produced metallo-beta-lactamase, while 26 (74.3%) showed the bla(SPM-1) gene. The frequency of Pseudomonas aeruginosa that produces metallo-beta-lactamase suggests that greater control over the dissemination of resistance in hospital environments is needed.

  17. Isolation and characterization of a bacteriophage specific for the lipopolysaccharide of rough derivatives of Pseudomonas aeruginosa strain PAO.

    PubMed Central

    Jarrell, K F; Kropinski, A M

    1981-01-01

    A lipopolysaccharide (LPS)-defective (rough) mutant of Pseudomonas aeruginosa PAO was isolated by selection for resistance to the LPS-specific phage E79. The LPS of this mutant, AK-1012, lacked the O-antigenic side chain-specific amino sugar fucosamine as well as the core-specific sugars glucose and rhamnose. Using this strain, we isolated and characterized a phage, phi PLS27, which is specifically inactivated upon incubation with LPS extracted from rough mutants of P. aeruginosa PAO. phi PLS27 was found to be a Bradley type C phage and was very similar to coliphage T7 in a number of properties, including size, buoyant density, mass, and the number of structural proteins. Images PMID:6787214

  18. Biosurfactant-producing bacterium, Pseudomonas aeruginosa MA01 isolated from spoiled apples: physicochemical and structural characteristics of isolated biosurfactant.

    PubMed

    Abbasi, Habib; Hamedi, Mir Manochehr; Lotfabad, Tayebe Bagheri; Zahiri, Hossein Shahbani; Sharafi, Hakimeh; Masoomi, Fatemeh; Moosavi-Movahedi, Ali Akbar; Ortiz, Antonio; Amanlou, Massoud; Noghabi, Kambiz Akbari

    2012-02-01

    An extensive investigation was conducted to isolate indigenous bacterial strains with outstanding performance for biosurfactant production from different types of spoiled fruits, food-related products and food processing industries. An isolate was selected from 800 by the highest biosurfactant yield in soybean oil medium and it was identified by 16S rRNA and the two most relevant hypervariable regions of this gene; V3 and V6 as Pseudomonas aeruginosa MA01. The isolate was able to produce 12 g/l of a glycolipid-type biosurfactant and generally less efficient to emulsify vegetable oils compared to hydrocarbons and could emulsify corn and coconut oils more than 50%. However, emulsification index (E(24)) of different hydrocarbons including hexane, toluene, xylene, brake oil, kerosene and hexadecane was between 55.8% and 100%. The surface tension of pure water decreased gradually with increasing biosurfactant concentration to 32.5 mNm(-1) with critical micelle concentration (CMC) value of 10.1mg/l. Among all carbon substrates examined, vegetable oils were the most effective on biosurfactant production. Two glycolipid fractions were purified from the biosurfactant crude extracts, and FTIR and ES-MS were used to determine the structure of these compounds. The analysis indicated the presence of three major monorhamnolipid species: R(1)C(10)C(10), R(1)C(10)C(12:1), and R(1)C(10)C(12); as well as another three major dirhamnolipid species: R(2)C(10)C(10), R(2)C(10)C(12:1), and R(2)C(10)C(12). The strain sweep experiment for measuring the linear viscoelastic of biosurfactant showed that typical behavior characteristics of a weak viscoelastic gel, with storage modulus greater than loss modulus at all frequencies examined, both showing some frequency dependence.

  19. In vitro comparison of Pseudomonas aeruginosa isolates with various susceptibilities to aminoglycosides and ten beta-lactam antibiotics.

    PubMed Central

    Wu, D H; Baltch, A L; Smith, R P

    1984-01-01

    Susceptibilities of 98 clinical isolates of Pseudomonas aeruginosa, including 33 strains with known mechanisms of amikacin resistance, were tested by the agar dilution method against 10 beta-lactam drugs. Ceftazidime, imipenem, and cefsulodin had the greatest activity, regardless of the aminoglycoside susceptibilities. The strains which were highly resistant to amikacin appeared to be less susceptible to some beta-lactam drugs, especially if their resistance was related to amikacin-inactivating enzymes; statistical significance, however, was observed for aztreonam only. PMID:6428308

  20. Antimicrobial susceptibility and minimal inhibitory concentration of Pseudomonas aeruginosa isolated from septic ocular surface disease in different animal species

    PubMed Central

    Leigue, L.; Montiani-Ferreira, F.; Moore, B.A.

    2016-01-01

    The purpose of this study was to evaluate the antibiotic susceptibility profile of Pseudomonas aeruginosa isolated from different animal species with septic ocular surface disease. Sixteen strains of P. aeruginosa were isolated from different species of animals (dog, cat, horse, penguin and brown bear) with ocular surface diseases such as conjunctivitis, keratocojnuctivits sicca and ulcerative keratitis. These isolates were tested against 11 different antimicrobials agents using the Kirby-Bauer disk-diffusion method. Minimum inhibitory concentrations (MICs) were determined using E-tests for two antibiotics (tobramycin and ciprofloxacin) commonly used in veterinary ophthalmology practice. Imipenem was the most effective antibiotic, with 100% of the strains being susceptible, followed by amikacin (87.5%), gentamicin, norfloxacin, gatifloxacin and polymyxin (both with 81.5%of susceptibility). MIC90 of ciprofloxacin was 2 µg/ml and the values found ranged from 0.094 µg/ml to 32 µg/ml. For tobramycin, MIC90 was 32 µg/ml and ranged from 0.25 µg/ml to 256 µg/ml. The most effective in vitro antibiotic tested against P. aeruginosa in this study was imipenem, followed by amikacin. The 3 mg/ml eye drops commercially available ciprofloxacin presentations were in vitro effective against all strains tested in this study if applied up to 4 hours after instillation. Whereas for tobramycin the 3 mg/ml eye drops commercial presentations were not in vitro effective against some strains isolated in this study. Thus for ocular infections with P. aeruginosa when using tobramycin the ideal recommendation would be to either use eye drops with higher concentrations or decrease the frequency intervals from four to a minimum of every two hours. PMID:27928519

  1. Whole-Genome Sequence of Multidrug-Resistant Pseudomonas aeruginosa Strain BAMCPA07-48, Isolated from a Combat Injury Wound

    PubMed Central

    Sanjar, Fatemeh; Karna, S. L. Rajasekhar; Chen, Tsute; Chen, Ping; Abercrombie, Johnathan J.

    2016-01-01

    We report here the complete genome sequence of Pseudomonas aeruginosa strain BAMCPA07-48, isolated from a combat injury wound. The closed genome sequence of this isolate is a valuable resource for pathogenome characterization of P. aeruginosa associated with wounds, which will aid in the development of a higher-resolution phylogenomic framework for molecular-guided pathogen-surveillance. PMID:27389262

  2. Widespread of ESBL- and carbapenemase GES-type genes on carbapenem-resistant Pseudomonas aeruginosa clinical isolates: a multicenter study in Mexican hospitals.

    PubMed

    Garza-Ramos, Ulises; Barrios, Humberto; Reyna-Flores, Fernando; Tamayo-Legorreta, Elsa; Catalan-Najera, Juan C; Morfin-Otero, Rayo; Rodríguez-Noriega, Eduardo; Volkow, Patricia; Cornejo-Juarez, Patricia; González, Alejandra; Gaytan-Martinez, Jesus; Del Rocío Gónzalez-Martínez, Marisela; Vazquez-Farias, Maria; Silva-Sanchez, Jesus

    2015-02-01

    The present work describes a prevalence of 36.2% of carbapenemases IMP-, VIM-, and GES-type on 124 imipenem-resistant Pseudomonas aeruginosa clinical isolates. The ESBL GES-19 and carbapenemase GES-20 genes were the most prevalent (84.4%) β-lactamases among imipenem-resistant P. aeruginosa clinical isolates in Mexico. These genes are chromosomal encoded on embedded class 1 integron arrays.

  3. Inhibition of quorum sensing-mediated biofilm formation in Pseudomonas aeruginosa by a locally isolated Bacillus cereus.

    PubMed

    Wahman, Shaimaa; Emara, Mohamed; Shawky, Riham M; El-Domany, Ramadan A; Aboulwafa, Mohammad Mabrouk

    2015-12-01

    Quorum sensing has been shown to play a crucial role in Pseudomonas aeruginosa pathogenesis where it activates expression of myriad genes that regulate the production of important virulence factors such as biofilm formation. Antagonism of quorum sensing is an excellent target for antimicrobial therapy and represents a novel approach to combat drug resistance. In this study, Chromobacterium violaceum biosensor strain was employed as a fast, sensitive, reliable, and easy to use tool for rapid screening of soil samples for Quorum Sensing Inhibitors (QSI) and the optimal conditions for maximal QSI production were scrutinized. Screening of 127 soil isolates showed that 43 isolates were able to breakdown the HHL signal. Out of the 43 isolates, 38 isolates were able to inhibit the violet color of the biosensor and to form easily detectable zones of color inhibition around their growth. A confirmatory bioassay was carried out after concentrating the putative positive cell-free lysates. Three different isolates that belonged to Bacillus cereus group were shown to have QSI activities and their QSI activities were optimized by changing their culture conditions. Further experiments revealed that the cell-free lysates of these isolates were able to inhibit biofilm formation by P. aeruginosa clinical isolates.

  4. Detection of blaPER-1 & blaOxa10 among imipenem resistant isolates of Pseudomonas aeruginosa isolated from burn patients hospitalized in Shiraz Burn Hospital

    PubMed Central

    Emami, Amir; Bazargani, Abdollah; Mohammadi, Ali Akbar; Zardosht, Mitra; Seyed Jafari, Seyed Morteza

    2015-01-01

    Background and Objectives: Pseudomonas aeruginosa is one of the most important Gram negative opportunistic bacteria which causes infection among burn patients. Resistance to the antibiotics in this group of bacteria is increased due to the activity of extended spectrum β-lactamase (ESBLs) genes. In the current study, we investigated the prevalence of two genes (blaPER-1 & blaOxa10) related β-lactamase genes among imipenem resistance clinical isolates of P. aeruginosa in hospitalized patients. Materials and Methods: From May 2010 to March 2011, 270 P. aeruginosa isolated from hospitalized burned patients’ wounds in Shiraz Burn Hospital, were tested for Imipenem resistance by disk diffusion method. Presence of ESBLs exo-enzyme, blaPER-1 and blaOxa10 genes were also evaluated in the resistant isolate. Results: 210 (77.7%) of 270 P. aeruginosa isolates were resistant to imipenem. blaPER-1 and blaOxa10 were detected among 168 (80.0%) of imipenem resistant isolates. Furthermore, 160 (76.2%) of them had blaOxa10 gene and 84 (40.0%) of them had blaPER-1 while 63 (30.0%) resistant isolates contained both genes simultaneously. Conclusion: This study showed a high prevalence of blaPER-1 and blaOxa10 genes in hospitalized burn patients in south west of Iran. Therefore, it’s highly recommended to perform such tests routinely to evaluate the resistance pattern in order to better antibiotic selection in the burned patients. PMID:26644867

  5. Potential of Ocimum basilicum L. and Salvia officinalis L. essential oils against biofilms of P. aeruginosa clinical isolates.

    PubMed

    Stojanović-Radić, Z; Pejcić, M; Stojanović, N; Sharifi-Rad, J; Stanković, N

    2016-08-29

    Biofilms are complex communities of microorganisms, responsible for more than 60% of the chronic human infections and they represent one of the leading concerns in medicine. Pseudomonas aeruginosa is human pathogenic bacteria which causes numerous diseases and is known for its ability to produce biofilm. Ocimum basilicum L. (basil) and Salvia officinalis L. (sage) are widely used plants in traditional medicine for the treatment of different conditions. Therefore, the aim of this study was to investigate the potential of basil and sage essential oils against P. aeruginosa biofilm producing strains. The efficacy of two essential oils on P. aeruginosa biofilm forming ability was determined using crystal violet method. Out of 15 strains isolated from different clinical biological samples, two were strong, 11 moderate and one weak biofilm producer. Good efficacy of sage essential oil towards strong and weak biofilm producers, but not of basil essential oil, was observed. In the case of moderate biofilm producers, 81.8% showed lower biofilm production after incubation with the sage oil, while 63.6% showed the reduction of biofilm production after basil essential oil treatment. The obtained results showed high potential of both oils for the treatment of persistent infections caused by Pseudomonas aeruginosa biofilms.

  6. Isolation and engineering of plant growth promoting rhizobacteria Pseudomonas aeruginosa for enhanced cadmium bioremediation.

    PubMed

    Huang, Junli; Liu, Zhaobing; Li, Shiyu; Xu, Bo; Gong, Yahui; Yang, Yan; Sun, Hanxiao

    2016-11-25

    Although many bacteria are tolerant to heavy metals and play important roles in the immobilization of heavy metals, they cannot always be dependably reproduced under field conditions. In this work, a cadmium (Cd)-resistant bacterium was isolated from a Cd-contaminated oil field and identified as Pseudomonas aeruginosa (Pse-w). We then determined various plant growth promoting features such as the solubilization of phosphate, and the production of indole-3-acetic acid and siderophores. Lastly, we engineered the strain Pse-w-MT by targeting metallothioneins to the cell surface of Pse-w to immobilize Cd(2+) and promote plant growth. Our data revealed that Pse-w exhibited high levels of resistance to Cd(2+) (4 mM) and showed various plant growth promoting features. The engineered strain Pse-w-MT was found to adsorb Cd(2+) mainly via extracellular deposition, and had an enhanced ability for immobilizing Cd(2+) ions from the external media. Furthermore, the inoculation of Cd-polluted soil with Pse-w-MT significantly elevated the shoot and root biomass and leaf chlorophyll content. Similarly, plants inoculated with Pse-w-MT demonstrated markedly lower Cd(2+) accumulation in the root and shoot system. It was concluded that plant growth promoting rhizobacteria with a high Cd(2+) tolerance was an ideal candidate to be engineered for bioremediation and plant growth promotion against Cd-induced stress.

  7. Isolation of dicarboxylic acid- and glucose-binding proteins from Pseudomonas aeruginosa.

    PubMed Central

    Stinson, M W; Cohen, M A; Merrick, J M

    1976-01-01

    Inducible binding proteins for C4-dicarboxylic acids (DBP) and glucose (GBP) were isolated from Pseudomonas aeruginosa by extraction of exponential-phase cells with 0.2 M MgC12 (pH 8.5) and by an osmotic shock procedure without affecting cell viability. DBP synthesis was induced by growth on aspartate, alpha-ketoglutarate, succinate, fumarate, malate, and malonate but not by growth on acetate, citrate, pyruvate, or glucose. Binding of succinate by DBP was competitively inhibited by 10-fold concentrations of fumarate and malate but not by a variety of related substances. GBP synthesis and transport of methyl alpha-glucoside by whole cells were induced by growth on glucose or pyruvate plus galactose, 2-deoxyglucose, or methyl alpha-glucoside but not by growth on gluconate, succinate, acetate, or pyruvate. The binding of radioactive glucose by GBP was significantly inhibited by 10-fold concentrations of glucose, galactose, and glucose-1-phosphate but not by the other carbohydrates tested. The binding of glucose by GBP or succinate by DBP did not result in any chemical alteration of the substrates. PMID:824281

  8. Enhancement of Rhamnolipid Production in Residual Soybean Oil by an Isolated Strain of Pseudomonas aeruginosa

    NASA Astrophysics Data System (ADS)

    de Lima, C. J. B.; França, F. P.; Sérvulo, E. F. C.; Resende, M. M.; Cardoso, V. L.

    In the present work, the production of rhamnolipid from residual soybean oil (RSO) from food frying facilities was studied using a strain of Pseudomonas aeruginosa of contaminated lagoon, isolated from a hydrocarbon contaminated soil. The optimization of RSO, amonium nitrate, and brewery residual yeast concentrations was accomplished by a central composite experimental design and surface response analysis. The experiments were performed in 500-mL Erlenmeyer flasks containing 50mL of mineral medium, at 170 rpm and 30±1°C, for a 48-h fermentation period. Rhamnolipid production has been monitored by measurements of surface tension, rhamnose concentration, and emulsifying activity. The best-planned results, located on the central point, have corresponded to 22g/L of RSO, 5.625 g/ L of NH4NO3' and 11.5 g/L of brewery yeast. At the maximum point the values for rhamnose and emulsifying index were 2.2g/L and 100%, respectively.

  9. Evaluation of the In Vitro Activity of Ceftazidime-Avibactam and Ceftolozane-Tazobactam against Meropenem-Resistant Pseudomonas aeruginosa Isolates

    PubMed Central

    Buehrle, Deanna J.; Shields, Ryan K.; Chen, Liang; Hao, Binghua; Press, Ellen G.; Alkrouk, Ammar; Potoski, Brian A.; Kreiswirth, Barry N.; Nguyen, M. Hong

    2016-01-01

    We compared ceftazidime-avibactam, ceftolozane-tazobactam, ceftazidime, cefepime, and piperacillin-tazobactam MICs for 38 meropenem-resistant Pseudomonas aeruginosa isolates. No isolates harbored carbapenemases; 74% were oprD mutants. Ceftazidime-avibactam and ceftolozane-tazobactam were active against 92% of the isolates, including 80% that were resistant to all three β-lactams. Forty-three percent of ceftazidime-avibactam-susceptible isolates and 6% of ceftolozane-tazobactam-susceptible isolates exhibited MICs at the respective breakpoints. Ceftolozane-tazobactam and ceftazidime-avibactam are therapeutic options for meropenem-resistant P. aeruginosa infections that should be used judiciously to preserve activity. PMID:26976862

  10. Synthesis and electrochemical detection of a thiazolyl-indole natural product isolated from the nosocomial pathogen Pseudomonas aeruginosa.

    PubMed

    Buzid, Alyah; Muimhneacháin, Eoin Ó; Reen, F Jerry; Hayes, Phyllis E; Pardo, Leticia M; Shang, Fengjun; O'Gara, Fergal; Sperry, Jonathan; Luong, John H T; Glennon, Jeremy D; McGlacken, Gerard P

    2016-09-01

    Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen, capable of surviving in a broad range of natural environments and quickly acquiring resistance. It is associated with hospital-acquired infections, particularly in patients with compromised immunity, and is the primary cause of morbidity and mortality in cystic fibrosis (CF) patients. P. aeruginosa is also of nosocomial importance on dairy farms and veterinary hospitals, where it is a key morbidity factor in bovine mastitis. P. aeruginosa uses a cell-cell communication system consisting of signalling molecules to coordinate bacterial secondary metabolites, biofilm formation, and virulence. Simple and sensitive methods for the detection of biomolecules as indicators of P. aeruginosa infection would be of great clinical importance. Here, we report the synthesis of the P. aeruginosa natural product, barakacin, which was recently isolated from the bovine ruminal strain ZIO. A simple and sensitive electrochemical method was used for barakacin detection using a boron-doped diamond (BDD) and glassy carbon (GC) electrodes, based on cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The influence of electrolyte pH on the peak potential and peak currents was also investigated. At pH 2.0, the peak current was linearly dependent on barakacin concentration (in the range used, 1-10 μM), with correlation coefficients greater than 0.98 on both electrodes. The detection limit (S/N = 3) on the BDD electrode was 100-fold lower than that obtained on the GC electrode. The optimized method using the BDD electrode was extended to bovine (cow feces) and human (sputum of a CF patient) samples. Spiked barakacin was easily detected in these matrices at a limit of 0.5 and 0.05 μM, respectively. Graphical abstract Electrochemical detection of barakacin.

  11. An Investigation of Antibacterial Resistance Patterns Among Acinetobacter baumannii and Pseudomonas aeruginosa Isolates Collected from Intensive Care Units of a University-Affiliated Hospital in Ahvaz, Iran

    PubMed Central

    Izadpour, Farrokh; Ranjbari, Nastaran; Aramesh, Mohammad-Reza; Moosavian, Mojtaba; ShahAli, Shiva; Larki, Farzaneh; Tabesh, Hamed; Morvaridi, Afrooz

    2016-01-01

    Background In recent decades, multidrug-resistant non-fermenting Gram-negative pathogens, particularly Acinetobacter baumannii and Pseudomonas aeruginosa, have been recognized as a major cause of healthcare-associated and nosocomial infections and outbreaks. Objectives The aim of this study was to determine the prevalence and pattern of antibiotic resistance in A. baumannii and P. aeruginosa isolates collected from intensive care units (ICUs). Methods One hundred fifty-five clinical isolates, including 80 (51.6%) isolates of A. baumannii and 75 (48.4%) isolates of P. aeruginosa, from hospitalized patients in the ICUs of a teaching hospital in Ahvaz, Iran, were collected from January 1 to December 30, 2013. The organisms were identified with conventional bacteriological methods, and antimicrobial susceptibility testing was performed on all isolates in accordance with clinical laboratory and standards institute (CLSI) guidelines. Results The maximum resistance rates among A. baumannii isolates were observed for ciprofloxacin and trimethoprim-sulfamethoxazole (96.9% and 95.2%, respectively). For P. aeruginosa isolates, the maximum resistance rates were reported for ceftriaxone and trimethoprim-sulfamethoxazole (97.2% and 92.4%, respectively). Conclusions The majority of A. baumannii and P. aeruginosa isolates were found to be resistant to commonly recommended antibiotics. Therefore, surveillance of antibiotic consumption and proper antibiotic administration guidelines are essential for preventing major outbreaks in the future. PMID:27800136

  12. Sequence Types 235, 111, and 132 Predominate among Multidrug-Resistant Pseudomonas aeruginosa Clinical Isolates in Croatia

    PubMed Central

    Izdebski, Radosław; Butic, Iva; Jelic, Marko; Abram, Maja; Koscak, Iva; Baraniak, Anna; Hryniewicz, Waleria; Gniadkowski, Marek; Tambic Andrasevic, Arjana

    2014-01-01

    A population analysis of 103 multidrug-resistant Pseudomonas aeruginosa isolates from Croatian hospitals was performed. Twelve sequence types (STs) were identified, with a predominance of international clones ST235 (serotype O11 [41%]), ST111 (serotype O12 [15%]), and ST132 (serotype O6 [11%]). Overexpression of the natural AmpC cephalosporinase was common (42%), but only a few ST235 or ST111 isolates produced VIM-1 or VIM-2 metallo-β-lactamases or PER-1 or GES-7 extended-spectrum β-lactamases. PMID:25070098

  13. Nutritional requirement among Pseudomonas aeruginosa isolates recovered from respiratory clinical specimens at a tertiary hospital from South of Brazil

    PubMed Central

    Perez, Leandro Reus Rodrigues; de Freitas, Ana Lúcia Peixoto; Barth, Afonso Luís

    2011-01-01

    We screened 349 isolates of P. aeruginosa from cystic fibrosis (CF+) and non-cystic fibrosis (CF-) patients for the auxotrophy. Fourteen (4.0%) were auxotrophic and among them only one was recovered from CF-patient showing that this characteristic is strongly associated with cystic fibrosis. In total, a requirement for 5 different compounds (or combination) was verified and, of these, methionine was the most common single amino acid required. Only one auxotrophic isolate was no able to produce biofilm in vitro. PMID:24031723

  14. Environmental variation alters the fitness effects of rifampicin resistance mutations in Pseudomonas aeruginosa.

    PubMed

    Gifford, Danna R; Moss, Ethan; MacLean, R Craig

    2016-03-01

    The fitness effects of antibiotic resistance mutations in antibiotic-free conditions play a key role in determining the long-term maintenance of resistance. Although resistance is usually associated with a cost, the impact of environmental variation on the cost of resistance is poorly understood. Here, we test the impact of heterogeneity in temperature and resource availability on the fitness effects of antibiotic resistance using strains of the pathogenic bacterium Pseudomonas aeruginosa carrying clinically important rifampicin resistance mutations. Although the rank order of fitness was generally maintained across environments, fitness effects relative to the wild type differed significantly. Changes in temperature had a profound impact on the fitness effects of resistance, whereas changes in carbon substrate had only a weak impact. This suggests that environmental heterogeneity may influence whether the costs of resistance are likely to be ameliorated by second-site compensatory mutations or by reversion to wild-type rpoB. Our results highlight the need to consider environmental heterogeneity and genotype-by-environment interactions for fitness in models of resistance evolution.

  15. Label-free SRM-based relative quantification of antibiotic resistance mechanisms in Pseudomonas aeruginosa clinical isolates.

    PubMed

    Charretier, Yannick; Köhler, Thilo; Cecchini, Tiphaine; Bardet, Chloé; Cherkaoui, Abdessalam; Llanes, Catherine; Bogaerts, Pierre; Chatellier, Sonia; Charrier, Jean-Philippe; Schrenzel, Jacques

    2015-01-01

    Both acquired and intrinsic mechanisms play a crucial role in Pseudomonas aeruginosa antibiotic resistance. Many clinically relevant resistance mechanisms result from changes in gene expression, namely multidrug efflux pump overproduction, AmpC β-lactamase induction or derepression, and inactivation or repression of the carbapenem-specific porin OprD. Changes in gene expression are usually assessed using reverse-transcription quantitative real-time PCR (RT-qPCR) assays. Here, we evaluated label-free Selected Reaction Monitoring (SRM)-based mass spectrometry to directly quantify proteins involved in antibiotic resistance. We evaluated the label-free SRM using a defined set of P. aeruginosa isolates with known resistance mechanisms and compared it with RT-qPCR. Referring to efflux systems, we found a more robust relative quantification of antibiotic resistance mechanisms by SRM than RT-qPCR. The SRM-based approach was applied to a set of clinical P. aeruginosa isolates to detect antibiotic resistance proteins. This multiplexed SRM-based approach is a rapid and reliable method for the simultaneous detection and quantification of resistance mechanisms and we demonstrate its relevance for antibiotic resistance prediction.

  16. Label-free SRM-based relative quantification of antibiotic resistance mechanisms in Pseudomonas aeruginosa clinical isolates

    PubMed Central

    Charretier, Yannick; Köhler, Thilo; Cecchini, Tiphaine; Bardet, Chloé; Cherkaoui, Abdessalam; Llanes, Catherine; Bogaerts, Pierre; Chatellier, Sonia; Charrier, Jean-Philippe; Schrenzel, Jacques

    2015-01-01

    Both acquired and intrinsic mechanisms play a crucial role in Pseudomonas aeruginosa antibiotic resistance. Many clinically relevant resistance mechanisms result from changes in gene expression, namely multidrug efflux pump overproduction, AmpC β-lactamase induction or derepression, and inactivation or repression of the carbapenem-specific porin OprD. Changes in gene expression are usually assessed using reverse-transcription quantitative real-time PCR (RT-qPCR) assays. Here, we evaluated label-free Selected Reaction Monitoring (SRM)-based mass spectrometry to directly quantify proteins involved in antibiotic resistance. We evaluated the label-free SRM using a defined set of P. aeruginosa isolates with known resistance mechanisms and compared it with RT-qPCR. Referring to efflux systems, we found a more robust relative quantification of antibiotic resistance mechanisms by SRM than RT-qPCR. The SRM-based approach was applied to a set of clinical P. aeruginosa isolates to detect antibiotic resistance proteins. This multiplexed SRM-based approach is a rapid and reliable method for the simultaneous detection and quantification of resistance mechanisms and we demonstrate its relevance for antibiotic resistance prediction. PMID:25713571

  17. Mechanisms of intrinsic resistance and acquired susceptibility of Pseudomonas aeruginosa isolated from cystic fibrosis patients to temocillin, a revived antibiotic

    PubMed Central

    Chalhoub, Hussein; Pletzer, Daniel; Weingart, Helge; Braun, Yvonne; Tunney, Michael M.; Elborn, J. Stuart; Rodriguez-Villalobos, Hector; Plésiat, Patrick; Kahl, Barbara C.; Denis, Olivier; Winterhalter, Mathias; Tulkens, Paul M.; Van Bambeke, Françoise

    2017-01-01

    The β-lactam antibiotic temocillin (6-α-methoxy-ticarcillin) shows stability to most extended spectrum β-lactamases, but is considered inactive against Pseudomonas aeruginosa. Mutations in the MexAB-OprM efflux system, naturally occurring in cystic fibrosis (CF) isolates, have been previously shown to reverse this intrinsic resistance. In the present study, we measured temocillin activity in a large collection (n = 333) of P. aeruginosa CF isolates. 29% of the isolates had MICs ≤ 16 mg/L (proposed clinical breakpoint for temocillin). Mutations were observed in mexA or mexB in isolates for which temocillin MIC was ≤512 mg/L (nucleotide insertions or deletions, premature termination, tandem repeat, nonstop, and missense mutations). A correlation was observed between temocillin MICs and efflux rate of N-phenyl-1-naphthylamine (MexAB-OprM fluorescent substrate) and extracellular exopolysaccharide abundance (contributing to a mucoid phenotype). OpdK or OpdF anion-specific porins expression decreased temocillin MIC by ~1 two-fold dilution only. Contrarily to the common assumption that temocillin is inactive on P. aeruginosa, we show here clinically-exploitable MICs on a non-negligible proportion of CF isolates, explained by a wide diversity of mutations in mexA and/or mexB. In a broader context, this work contributes to increase our understanding of MexAB-OprM functionality and help delineating how antibiotics interact with MexA and MexB. PMID:28091521

  18. Detection of Quorum Sensing Activity in the Multidrug-Resistant Clinical Isolate Pseudomonas aeruginosa Strain GB11

    PubMed Central

    Cheng, Huey Jia; Ee, Robson; Cheong, Yuet Meng; Tan, Wen-Si; Yin, Wai-Fong; Chan, Kok-Gan

    2014-01-01

    A multidrug-resistant clinical bacteria strain GB11 was isolated from a wound swab on the leg of a patient. Identity of stain GB11 as Pseudomonas aeruginosa was validated by using matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). Detection of the production of signaling molecules, N-acylhomoserine lactones (AHLs), was conducted using three different bacterial biosensors. A total of four different AHLs were found to be produced by strain GB11, namely N-butyryl homoserine lactone (C4-HSL), N-hexanoylhomoserine lactone (C6-HSL), N-octanoyl homoserine lactone (C8-HSL) and N-3-oxo-dodecanoylhomoserine lactone (3-oxo-C12-HSL) using high resolution liquid chromatography tandem mass spectrometry (LC-MS/MS). Of these detected AHLs, 3-oxo-C12-HSL was found to be the most abundant AHL produced by P. aeruginosa GB11. PMID:25019635

  19. Characterization of exo-s, exo-u, and alg virulence factors and antimicrobial resistance in Pseudomonas aeruginosa isolated from migratory Egyptian vultures from India.

    PubMed

    Sharma, Pradeep; Faridi, Farah; Mir, Irfan A; Sharma, Sandeep K

    2014-01-01

    This study of Pseudomonas aeruginosa in fecal droppings of migratory Egyptian vultures (Neophron p. percnopterus) revealed eight positive samples (n=25) by a 16S rRNA gene-based PCR in two consecutive winter seasons. Disk diffusion sensitivity testing revealed three multiple antimicrobial resistant (MAR) isolates. Genotypic characterization showed mutually exclusive exo-s and exo-u virulence genes in five and three isolates, respectively, while the alg gene was present in all of the isolates. MAR isolates with virulence genes were detected in both seasons. The Egyptian vultures could potentially be vectors of pathogenic and MAR P. aeruginosa, thereby affecting regional control and preventive measures.

  20. Waste Isolation Pilot Plant Environmental Monitoring Plan

    SciTech Connect

    None, None

    2008-03-12

    U.S. Department of Energy (DOE) Order 450.1, Environmental Protection Program, requires each DOE site to conduct environmental monitoring. Environmental monitoring at the Waste Isolation Pilot Plant (WIPP) is conducted in order to: (a) Verify and support compliance with applicable federal, state, and local environmental laws, regulations, permits, and orders; (b) Establish baselines and characterize trends in the physical, chemical, and biological condition of effluent and environmental media; (c) Identify potential environmental problems and evaluate the need for remedial actions or measures to mitigate the problems; (d) Detect, characterize, and report unplanned releases; (e) Evaluate the effectiveness of effluent treatment and control, and pollution abatement programs; and (f) Determine compliance with commitments made in environmental impact statements, environmental assessments, safety analysis reports, or other official DOE documents. This Environmental Monitoring Plan (EMP) explains the rationale and design criteria for the environmental monitoring program, extent and frequency of monitoring and measurements, procedures for laboratory analyses, quality assurance (QA) requirements, program implementation procedures, and direction for the preparation and disposition of reports. Changes to the environmental monitoring program may be necessary to allow the use of advanced technology and new data collection techniques. This EMP will document changes in the environmental monitoring program. Guidance for preparation of EMPs is contained in DOE/EH-0173T, Environmental Regulatory Guide for Radiological Effluent Monitoring and Environmental Surveillance.

  1. Plasmid Profile Analysis and bla VIM Gene Detection of Metalo β-lactamase (MBL) Producing Pseudomonas aeruginosa Isolates from Clinical Samples

    PubMed Central

    M, Jeya

    2014-01-01

    Introduction:Pseudomonas aeruginosa is a frequent colonizer of hospitalized patients. They are responsible for serious infections such as meningitis, urological infections, septicemia and pneumonia. Carbapenem resistance of Pseudomonas aeruginosa is currently increasingly reported which is often mediated by production of metallo-β-lactamase (MBL). Multidrug resistant Pseudomonas aeruginosa isolates may involve reduced cell wall permeability, production of chromosomal and plasmid mediated β lactamases, aminoglycosides modifying enzymes and an active multidrug efflux mechanism. Objective: This study is aimed to detect the presence and the nature of plasmids among metallo-β-lactamase producing Pseudomonas aeruginosa isolates. Also to detect the presence of bla VIM gene from these isolates. Materials and Methods: Clinical isolates of Pseudomonas aeruginosa showing the metalo-β-lactamase enzyme (MBL) production were isolated. The MBL production was confirmed by three different methods. From the MBL producing isolates plasmid extraction was done by alkaline lysis method. Plasmid positive isolates were subjected for blaVIM gene detection by PCR method. Results: Two thousand seventy six clinical samples yielded 316 (15.22%) Pseudomonas aeruginosa isolates, out of which 141 (44.62%) were multidrug resistant. Among them 25 (17.73%) were metallo-β-lactamase enzyme producers. Plasmids were extracted from 18 out of 25 isolates tested. Five out of 18 isolates were positive for the blaVIM gene detection by the PCR amplification. Conclusion: The MBL producers were susceptible to polymyxin /colistin with MIC ranging from 0.5 – 2μg/ml. Molecular detection of specific genes bla VIM were positive among the carbapenem resistant isolates. PMID:25120980

  2. Isolation and Characterization of a Cyanophage Infecting the Toxic Cyanobacterium Microcystis aeruginosa

    PubMed Central

    Yoshida, Takashi; Takashima, Yukari; Tomaru, Yuji; Shirai, Yoko; Takao, Yoshitake; Hiroishi, Shingo; Nagasaki, Keizo

    2006-01-01

    We isolated a cyanophage (Ma-LMM01) that specifically infects a toxic strain of the bloom-forming cyanobacterium Microcystis aeruginosa. Transmission electron microscopy showed that the virion is composed of anisometric head and a tail complex consisting of a central tube and a contractile sheath with helical symmetry. The morphological features and the host specificity suggest that Ma-LMM01 is a member of the cyanomyovirus group. Using semi-one-step growth experiments, the latent period and burst size were estimated to be 6 to 12 h and 50 to 120 infectious units per cell, respectively. The size of the phage genome was estimated to be ca. 160 kbp using pulse-field gel electrophoresis; the nucleic acid was sensitive to DNase I, Bal31, and all 14 restriction enzymes tested, suggesting that it is a linear double-stranded DNA having a low level of methylation. Phylogenetic analyses based on the deduced amino acid sequences of two open reading frames coding for ribonucleotide reductase alpha- and beta-subunits showed that Ma-LMM01 forms a sister group with marine and freshwater cyanobacteria and is apparently distinct from T4-like phages. Phylogenetic analysis of the deduced amino acid sequence of the putative sheath protein showed that Ma-LMM01 does not form a monophyletic group with either the T4-like phages or prophages, suggesting that Ma-LMM01 is distinct from other T4-like phages that have been described despite morphological similarity. The host-phage system which we studied is expected to contribute to our understanding of the ecology of Microcystis blooms and the genetics of cyanophages, and our results suggest the phages could be used to control toxic cyanobacterial blooms. PMID:16461672

  3. Cystic Fibrosis Isolates of Pseudomonas aeruginosa Retain Iron-Regulated Antimicrobial Activity against Staphylococcus aureus through the Action of Multiple Alkylquinolones.

    PubMed

    Nguyen, Angela T; Jones, Jace W; Cámara, Miguel; Williams, Paul; Kane, Maureen A; Oglesby-Sherrouse, Amanda G

    2016-01-01

    Cystic fibrosis (CF) is a hereditary disease that predisposes individuals to pulmonary dysfunction and chronic infections. Early infection of the CF lung with Staphylococcus aureus is common, while Pseudomonas aeruginosa becomes dominant as disease progresses. Emergence of P. aeruginosa likely depends on the action of multiple 2-alkyl-4-(1H)-quinolones (AQ) secreted by this organism. We recently showed that antimicrobial activity against S. aureus is enhanced by iron depletion and is dependent upon multiple AQ metabolites. Two of these AQs, the Pseudomonas quinolone signal [PQS; 2-heptyl-3-hydroxy-4(1H)-quinolone] and 2-heptyl-4-hydroxyquinoline (HHQ), are quorum sensing molecules that activate the expression of multiple microbicidal factors. Here we show for the first time that HHQ also exhibits innate antimicrobial activity against S. aureus. We further show that iron depletion potentiates the antistaphylococcal activity of HHQ, as well as 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO), another AQ that functions as a cytochrome B inhibitor. Notably, we found that deletion of the genes for the terminal biosynthetic steps for either PQS or HQNO results in overproduction of the HHQ intermediate, likely maintaining the ability of these mutants to mediate antimicrobial activity. Compensatory increases in HHQ were also observed in PQS-deficient CF isolates, which also retained the ability to mediate iron-regulated antimicrobial activity against S. aureus. These studies demonstrate that iron-regulated antimicrobial activity of P. aeruginosa against S. aureus is due to the cumulative effects of multiple AQ metabolites, both the production and activity of which are modulated by environmental iron levels.

  4. Cystic Fibrosis Isolates of Pseudomonas aeruginosa Retain Iron-Regulated Antimicrobial Activity against Staphylococcus aureus through the Action of Multiple Alkylquinolones

    PubMed Central

    Nguyen, Angela T.; Jones, Jace W.; Cámara, Miguel; Williams, Paul; Kane, Maureen A.; Oglesby-Sherrouse, Amanda G.

    2016-01-01

    Cystic fibrosis (CF) is a hereditary disease that predisposes individuals to pulmonary dysfunction and chronic infections. Early infection of the CF lung with Staphylococcus aureus is common, while Pseudomonas aeruginosa becomes dominant as disease progresses. Emergence of P. aeruginosa likely depends on the action of multiple 2-alkyl-4-(1H)-quinolones (AQ) secreted by this organism. We recently showed that antimicrobial activity against S. aureus is enhanced by iron depletion and is dependent upon multiple AQ metabolites. Two of these AQs, the Pseudomonas quinolone signal [PQS; 2-heptyl-3-hydroxy-4(1H)-quinolone] and 2-heptyl-4-hydroxyquinoline (HHQ), are quorum sensing molecules that activate the expression of multiple microbicidal factors. Here we show for the first time that HHQ also exhibits innate antimicrobial activity against S. aureus. We further show that iron depletion potentiates the antistaphylococcal activity of HHQ, as well as 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO), another AQ that functions as a cytochrome B inhibitor. Notably, we found that deletion of the genes for the terminal biosynthetic steps for either PQS or HQNO results in overproduction of the HHQ intermediate, likely maintaining the ability of these mutants to mediate antimicrobial activity. Compensatory increases in HHQ were also observed in PQS-deficient CF isolates, which also retained the ability to mediate iron-regulated antimicrobial activity against S. aureus. These studies demonstrate that iron-regulated antimicrobial activity of P. aeruginosa against S. aureus is due to the cumulative effects of multiple AQ metabolites, both the production and activity of which are modulated by environmental iron levels. PMID:27512392

  5. Post-antibiotic effect of orbifloxacin against Escherichia coli and Pseudomonas aeruginosa isolates from dogs.

    PubMed

    Harada, Kazuki; Shimizu, Takae; Kataoka, Yasushi; Takahashi, Toshio

    2012-03-20

    Orbifloxacin is a fluoroquinolone drug used widely in companion animal medicine. In this study, we firstly determined post-antibiotic effects (PAEs) and post-antibiotic sub-minimum inhibitory concentrations (MIC) effects (PA-SMEs) of orbifloxacin for two strains each of Escherichia coli and Pseudomonas aeruginosa from dogs, and these parameters were compared with those of enrofloxacin. At twice the MIC, the PAEs of orbifloxacin ranged from -0.28-0.93 h (mean, 0.29 h) for E. coli and -0.18-1.18 h (mean, 0.37 h) for P. aeruginosa. These parameters were not significantly different for E. coli and shorter for P. aeruginosa, compared to enrofloxacin (P < 0.05). Continued exposure to 0.1, 0.2, and 0.3 the MIC of orbifloxacin resulted in average PA-SMEs of 0.55, 1.11, and 2.03 h, respectively, for E. coli, and 1.04, 1.40, and 2.47 h, respectively, for P. aeruginosa. These PA-SMEs, which had no significant differences with those of enrofloxacin, were significantly longer than the corresponding PAEs (P < 0.05). These results suggest that the PA-SME of orbifloxacin for E. coli and P. aeruginosa can be meaningfully prolonged by increase of sub-MICs.

  6. Molecular detection of metallo-β-lactamase gene blaVIM-1 in imipenem-resistant Pseudomonas aeruginosa strains isolated from hospitalized patients in the hospitals of Isfahan

    PubMed Central

    Sedighi, Mansour; Vaez, Hamid; Moghoofeie, Mohsen; Hadifar, Shima; Oryan, Golfam; Faghri, Jamshid

    2015-01-01

    Background: Pseudomonas aeruginosa is an opportunistic human pathogen that causes serious problems, especially in people, who have immunodeficiency. In recent times, metallo-β-lactamase (MBLs) resistance in this bacterium has led to some difficulties in treating bacterial infections. The metallo-beta-lactamase family of genes, including blaVIM-1, is being reported with increasing frequency worldwide. The aim of this study is the detection of the metallo-β-lactamase gene blaVIM-1 in imipenem-resistant P. aeruginosa (IRPA) strains isolated from hospitalized patients. Materials and Methods: In this study, 106 P. aeruginosa samples were isolated from various nosocomial infections. The isolates were identified, tested for susceptibility to various antimicrobial agents by the Kirby-Bauer disk diffusion method, and all the imipenem-resistant isolates were screened for the presence of MBLs by using the combined disk (IMP-EDTA). The minimal inhibitory concentration (MIC) of imipenem was determined by E-test on the Mueller-Hinton agar. To detect the blaVIM-1 gene, the isolates were subjected to a polymerase chain reaction (PCR). Results: Of all the P. aeruginosa isolates, 62 (58.5%) were found to be imipenem-resistant P. aeruginosa (MIC ≥32 μg/ml). Twenty-six (42%) of the imipenem-resistant isolates were MBL positive. None of these isolates carried the blaVIM-1 gene using the PCR assay. Conclusion: The results demonstrated the serious therapeutic threat of the MBL-producing P. aeruginosa populations. The rate of imipenem resistance due to MBL was increased dramatically. Early detection and infection-control practices are the best antimicrobial strategies for this organism. None of MBL-producing isolates in this study carry the blaVIM-1 gene; therefore, another gene in the MBL family should be investigated. PMID:25802826

  7. Characterization of the Newly Isolated Lytic Bacteriophages KTN6 and KT28 and Their Efficacy against Pseudomonas aeruginosa Biofilm.

    PubMed

    Danis-Wlodarczyk, Katarzyna; Olszak, Tomasz; Arabski, Michal; Wasik, Slawomir; Majkowska-Skrobek, Grazyna; Augustyniak, Daria; Gula, Grzegorz; Briers, Yves; Jang, Ho Bin; Vandenheuvel, Dieter; Duda, Katarzyna Anna; Lavigne, Rob; Drulis-Kawa, Zuzanna

    2015-01-01

    We here describe two novel lytic phages, KT28 and KTN6, infecting Pseudomonas aeruginosa, isolated from a sewage sample from an irrigated field near Wroclaw, in Poland. Both viruses show characteristic features of Pbunalikevirus genus within the Myoviridae family with respect to shape and size of head/tail, as well as LPS host receptor recognition. Genome analysis confirmed the similarity to other PB1-related phages, ranging between 48 and 96%. Pseudomonas phage KT28 has a genome size of 66,381 bp and KTN6 of 65,994 bp. The latent period, burst size, stability and host range was determined for both viruses under standard laboratory conditions. Biofilm eradication efficacy was tested on peg-lid plate assay and PET membrane surface. Significant reduction of colony forming units was observed (70-90%) in 24 h to 72 h old Pseudomonas aeruginosa PAO1 biofilm cultures for both phages. Furthermore, a pyocyanin and pyoverdin reduction tests reveal that tested phages lowers the amount of both secreted dyes in 48-72 h old biofilms. Diffusion and goniometry experiments revealed the increase of diffusion rate through the biofilm matrix after phage application. These characteristics indicate these phages could be used to prevent Pseudomonas aeruginosa infections and biofilm formation. It was also shown, that PB1-related phage treatment of biofilm caused the emergence of stable phage-resistant mutants growing as small colony variants.

  8. Effect of Quorum Quenching Lactonase in Clinical Isolates of Pseudomonas aeruginosa and Comparison with Quorum Sensing Inhibitors.

    PubMed

    Guendouze, Assia; Plener, Laure; Bzdrenga, Janek; Jacquet, Pauline; Rémy, Benjamin; Elias, Mikael; Lavigne, Jean-Philippe; Daudé, David; Chabrière, Eric

    2017-01-01

    Pseudomonas aeruginosa is a Gram negative pathogenic bacterium involved in many human infections including otitis, keratitis, pneumonia, and diabetic foot ulcers. P. aeruginosa uses a communication system, referred to as quorum sensing (QS), to adopt a group behavior by synchronizing the expression of certain genes. Among the regulated traits, secretion of proteases or siderophores, motility and biofilm formation are mainly involved in the pathogenicity. Many efforts have been dedicated to the development of quorum sensing inhibitors (QSI) and quorum quenching (QQ) agents to disrupt QS. QQ enzymes have been particularly considered as they may act in a catalytic way without entering the cell. Here we focus on the lactonase SsoPox which was previously investigated for its ability to degrade the signaling molecules, acyl-homoserine lactones, in particular on the engineered variant SsoPox-W263I. We highlight the potential of SsoPox-W263I to inhibit the virulence of 51 clinical P. aeruginosa isolates from diabetic foot ulcers by decreasing the secretion of two virulence factors, proteases and pyocyanin, as well as biofilm formation. We further compared the effect of SsoPox-W263I to the comprehensively described QSI, 5-fluorouracil and C-30. We found the lactonase SsoPox-W263I to be significantly more effective than the tested QSI at their respective concentration optimum and to retain its activity after immobilization steps, paving the way for future therapeutic applications.

  9. Removal of toxic Co-EDTA complex by a halophilic solar-salt-pan isolate Pseudomonas aeruginosa SPB-1.

    PubMed

    Paraneeiswaran, A; Shukla, Sudhir K; Subba Rao, T; Prashanth, K

    2014-01-01

    In this study, a promising bioremediation approach was developed to remove [Co(III)-EDTA](-) complex that is generated during the waste management process. Though several studies have been reported on bioremediation of cobalt, the removal of [Co(III)-EDTA](-) complex has not been tested. A [Co(III)-EDTA](-) resistant bacterium, Pseudomonas aeruginosa SPB-1 was isolated from the solar-salt-pan and physical parameters were optimized for its growth. The various studies showed that the removal of [Co(III)-EDTA](-) from the bulk liquid was due to the adsorption of the complex by the biomass. Using absorption/desorption isotherm over a range of pH (1-8), the maximum adsorption of [Co(III)-EDTA](-) was found to be at pH 7.0 and maximum desorption from the biomass occurred at pH 1.0, thus rendering an ion exchange property to P. aeruginosa SPB-1 biomass. P. aeruginosa SPB-1 biomass could be used as bio-resin that showed 80.4±3.27% adsorption capacity up to fourth cycle and the biomass was viable till the ninth cycle with 10.5±7.3% adsorption. Radiation tolerance potential i.e. D10 value for the strain was found to be ~300 Gy, which suggests the potential use of the bacterium in bioremediation of moderately active nuclear waste.

  10. Characterization of the Newly Isolated Lytic Bacteriophages KTN6 and KT28 and Their Efficacy against Pseudomonas aeruginosa Biofilm

    PubMed Central

    Danis-Wlodarczyk, Katarzyna; Olszak, Tomasz; Arabski, Michal; Wasik, Slawomir; Majkowska-Skrobek, Grazyna; Augustyniak, Daria; Gula, Grzegorz; Briers, Yves; Jang, Ho Bin; Vandenheuvel, Dieter; Duda, Katarzyna Anna; Lavigne, Rob; Drulis-Kawa, Zuzanna

    2015-01-01

    We here describe two novel lytic phages, KT28 and KTN6, infecting Pseudomonas aeruginosa, isolated from a sewage sample from an irrigated field near Wroclaw, in Poland. Both viruses show characteristic features of Pbunalikevirus genus within the Myoviridae family with respect to shape and size of head/tail, as well as LPS host receptor recognition. Genome analysis confirmed the similarity to other PB1-related phages, ranging between 48 and 96%. Pseudomonas phage KT28 has a genome size of 66,381 bp and KTN6 of 65,994 bp. The latent period, burst size, stability and host range was determined for both viruses under standard laboratory conditions. Biofilm eradication efficacy was tested on peg-lid plate assay and PET membrane surface. Significant reduction of colony forming units was observed (70-90%) in 24 h to 72 h old Pseudomonas aeruginosa PAO1 biofilm cultures for both phages. Furthermore, a pyocyanin and pyoverdin reduction tests reveal that tested phages lowers the amount of both secreted dyes in 48-72 h old biofilms. Diffusion and goniometry experiments revealed the increase of diffusion rate through the biofilm matrix after phage application. These characteristics indicate these phages could be used to prevent Pseudomonas aeruginosa infections and biofilm formation. It was also shown, that PB1-related phage treatment of biofilm caused the emergence of stable phage-resistant mutants growing as small colony variants. PMID:25996839

  11. Effect of Quorum Quenching Lactonase in Clinical Isolates of Pseudomonas aeruginosa and Comparison with Quorum Sensing Inhibitors

    PubMed Central

    Guendouze, Assia; Plener, Laure; Bzdrenga, Janek; Jacquet, Pauline; Rémy, Benjamin; Elias, Mikael; Lavigne, Jean-Philippe; Daudé, David; Chabrière, Eric

    2017-01-01

    Pseudomonas aeruginosa is a Gram negative pathogenic bacterium involved in many human infections including otitis, keratitis, pneumonia, and diabetic foot ulcers. P. aeruginosa uses a communication system, referred to as quorum sensing (QS), to adopt a group behavior by synchronizing the expression of certain genes. Among the regulated traits, secretion of proteases or siderophores, motility and biofilm formation are mainly involved in the pathogenicity. Many efforts have been dedicated to the development of quorum sensing inhibitors (QSI) and quorum quenching (QQ) agents to disrupt QS. QQ enzymes have been particularly considered as they may act in a catalytic way without entering the cell. Here we focus on the lactonase SsoPox which was previously investigated for its ability to degrade the signaling molecules, acyl-homoserine lactones, in particular on the engineered variant SsoPox-W263I. We highlight the potential of SsoPox-W263I to inhibit the virulence of 51 clinical P. aeruginosa isolates from diabetic foot ulcers by decreasing the secretion of two virulence factors, proteases and pyocyanin, as well as biofilm formation. We further compared the effect of SsoPox-W263I to the comprehensively described QSI, 5-fluorouracil and C-30. We found the lactonase SsoPox-W263I to be significantly more effective than the tested QSI at their respective concentration optimum and to retain its activity after immobilization steps, paving the way for future therapeutic applications. PMID:28261183

  12. Two Novel Class I Integron Arrays Containing IMP-18 Metallo-β-Lactamase Gene in Pseudomonas aeruginosa Clinical Isolates from Puerto Rico

    PubMed Central

    Martínez, T.; Vazquez, G. J.; Aquino, E. E.; Goering, R. V.

    2012-01-01

    During a β-lactam resistance surveillance study, 12 IMP-18-positive Pseudomonas aeruginosa isolates belonging to 9 different pulsed-field gel electrophoresis groups were identified. In nine isolates, a class I integron with a novel gene array was identified that contained blaIMP-18 and blaOXA-224, while in two isolates the class I integron contained blaIMP-18 and blaOXA-2 but in a new arrangement. Our findings show the dissemination of two novel class I integrons in P. aeruginosa from different regions of Puerto Rico. PMID:22290962

  13. Waste Isolation Pilot Plant Environmental Monitoring Plan

    SciTech Connect

    Washington Regulatory and Environmental Services; Washington TRU Solutions LLC

    2004-02-19

    U.S. Department of Energy (DOE) Order 450.1, Environmental Protection Program, requires each DOE site to conduct environmental monitoring. Environmental monitoring at the Waste Isolation Pilot Plant (WIPP) is conducted in order to: (a) Verify and support compliance with applicable federal, state, and local environmental laws, regulations, permits, and orders; (b) Establish baselines and characterize trends in the physical, chemical, and biological condition of effluent and environmental media; (c) Identify potential environmental problems and evaluate the need for remedial actions or measures to mitigate the problem; (d) Detect, characterize, and report unplanned releases; (e) Evaluate the effectiveness of effluent treatment and control, and pollution abatement programs; and (f) Determine compliance with commitments made in environmental impact statements, environmental assessments, safety analysis reports, or other official DOE documents. This Environmental Monitoring Plan (EMP) has been written to contain the rationale and design criteria for the monitoring program, extent and frequency of monitoring and measurements, procedures for laboratory analyses, quality assurance (QA) requirements, program implementation procedures, and direction for the preparation and disposition of reports. Changes to the environmental monitoring program may be necessary to allow the use of advanced technology and new data collection techniques. This EMP will document any proposed changes in the environmental monitoring program. Guidance for preparation of Environmental Monitoring Plans is contained in DOE/EH-0173T, Environmental Regulatory Guide for Radiological Effluent Monitoring and Environmental Surveillance. The plan will be effective when it is approved by the appropriate Head of Field Organization or their designee. The plan discusses major environmental monitoring and hydrology activities at the WIPP and describes the programs established to ensure that WIPP operations do not

  14. blaVIM-2 Cassette-Containing Novel Integrons in Metallo-β-Lactamase-Producing Pseudomonas aeruginosa and Pseudomonas putida Isolates Disseminated in a Korean Hospital

    PubMed Central

    Lee, Kyungwon; Lim, Jong Back; Yum, Jong Hwa; Yong, Dongeun; Chong, Yunsop; Kim, June Myung; Livermore, David M.

    2002-01-01

    We investigated the phenotypic and genetic properties of metallo-β-lactamase-producing Pseudomonas isolates collected at a tertiary-care hospital in Korea since 1995. The prevalence of imipenem resistance among Pseudomonas aeruginosa isolates reached 16% in 1997, when 9% of the resistant organisms were found to produce VIM-2 β-lactamase, a class B enzyme previously found only in P. aeruginosa isolates from Europe. VIM-2-producing isolates of Pseudomonas putida were also detected. Resistance was transferable from both these species to P. aeruginosa PAO4089Rp by filter mating, although the resistance determinant could not be found on any detectable plasmid. Serotyping showed that many of the VIM-2-producing P. aeruginosa isolates belonged to serotypes O:11 and O:12, and pulsed-field gel electrophoresis of XbaI-digested genomic DNA revealed that many had identical profiles, whereas the P. putida isolates were diverse. Sequencing showed that the blaVIM-2 genes resided as cassettes in class 1 integrons. In contrast to previous VIM-encoding integrons, the integron sequenced from a P. aeruginosa isolate had blaVIM located downstream of a variant of aacA4. blaVIM also lay in a class 1 integron in a representative P. putida strain, but the organization of this integron was different from that sequenced from the P. aeruginosa strain. In conclusion, the metallo-β-lactamase produced by these imipenem-resistant Pseudomonas isolates was VIM-2, and the accumulation of producers reflected clonal dissemination as well as horizontal spread. Strict measures are required in order to control a further spread of resistance. PMID:11897589

  15. Changing susceptibility of Pseudomonas aeruginosa isolates from cystic fibrosis patients with the clinical use of newer antibiotics.

    PubMed Central

    Bosso, J A; Allen, J E; Matsen, J M

    1989-01-01

    To detect a change in antibiotic susceptibility patterns in Pseudomonas aeruginosa isolates upon the introduction and clinical use of ciprofloxacin, aztreonam, and ceftazidime, MICs for clinical isolates collected before introduction of the antibiotics, during early clinical use, and later were determined for these and seven other antipseudomonal antibiotics. Concomitant resistance to two or more antibiotics was also studied. Over the three study periods, rates of susceptibility to 9 of the 10 antibiotics decreased. The largest decrease occurred with ceftazidime. Analysis of subsets of isolates from patients treated with ciprofloxacin or aztreonam also showed declining susceptibility to the latter but a stabilization of susceptibility to the former after an initial decline. Concomitant resistance within and among antibiotic classes was common. PMID:2499252

  16. Genes required for and effects of alginate overproduction induced by growth of Pseudomonas aeruginosa on Pseudomonas isolation agar supplemented with ammonium metavanadate.

    PubMed

    Damron, F Heath; Barbier, Mariette; McKenney, Elizabeth S; Schurr, Michael J; Goldberg, Joanna B

    2013-09-01

    Pseudomonas aeruginosa is an opportunistic pathogen that can adapt to changing environments and can secrete an exopolysaccharide known as alginate as a protection response, resulting in a colony morphology and phenotype referred to as mucoid. However, how P. aeruginosa senses its environment and activates alginate overproduction is not fully understood. Previously, we showed that Pseudomonas isolation agar supplemented with ammonium metavanadate (PIAAMV) induces P. aeruginosa to overproduce alginate. Vanadate is a phosphate mimic and causes protein misfolding by disruption of disulfide bonds. Here we used PIAAMV to characterize the pathways involved in inducible alginate production and tested the global effects of P. aeruginosa growth on PIAAMV by a mutant library screen, by transcriptomics, and in a murine acute virulence model. The PA14 nonredundant mutant library was screened on PIAAMV to identify new genes that are required for the inducible alginate stress response. A functionally diverse set of genes encoding products involved in cell envelope biogenesis, peptidoglycan remodeling, uptake of phosphate and iron, phenazine biosynthesis, and other processes were identified as positive regulators of the mucoid phenotype on PIAAMV. Transcriptome analysis of P. aeruginosa cultures growing in the presence of vanadate showed differential expression of genes involved in virulence, envelope biogenesis, and cell stress pathways. In this study, it was observed that growth on PIAAMV attenuates P. aeruginosa in a mouse pneumonia model. Induction of alginate overproduction occurs as a stress response to protect P. aeruginosa, but it may be possible to modulate and inhibit these pathways based on the new genes identified in this study.

  17. Presence of exoY, exoS, exoU and exoT genes, antibiotic resistance and biofilm production among Pseudomonas aeruginosa isolates in Northwest Iran.

    PubMed

    Azimi, Somayeh; Kafil, Hossein Samadi; Baghi, Hossein Bannazadeh; Shokrian, Saeed; Najaf, Khadijeh; Asgharzadeh, Mohammad; Yousefi, Mehdi; Shahrivar, Firooz; Aghazadeh, Mohammad

    2016-01-01

    Hintergrund:Pseudomonas aeruginosa, ein Gram-negatives Stäbchenbakterium, besitzt eine wichtige Rolle als Krankheitserreger. Daher untersuchten wir Pseudomonas aeruginosa-Isolate im Nordwestiran auf das Vorkommen von exo-Genen und Biofilmbildnern. Material und Methode: 160 P. aeruginosa-Isolate wurden biochemisch identifiziert und die Antibiotikaresistenz charakterisiert. Die Fähigkeit zur Biofilmbildung wurde im Mikrotiterplatten-Assay, das Vorkommen von exo-Genen mit Allel-spezifischer PCR (Polymerase-Kettenreaktion) analysiert. Zur statistischen Analyse wurde der Chi-Quadrat-Test eingesetzt.Ergebnisse: Als effektivste Antibiotika erwiesen sich Colistin und Polymyxin B. 87% der Isolate waren Biofilmbildner, davon 69% mit massiver Biofilmbildung. In 55% der Isolate wurden exoY, in 52% exoU, in 26,3% exoS und in 5% exoT nachgewiesen. Schlussfolgerung: Die Analyse ergab eine unterschiedliche Verteilung der exo-Gene bei klinischen Isolaten von P. aeruginosa im Nordwestiran. ExoS und exoU kamen häufiger bei nicht biofilmbildenen Isolaten, exoY häufiger bei Biofilmbildnern vor. Die Ergebnisse können ein Hinweis auf die Bedeutung von exoY bei Biofilm bildenden Pseudomonas aeruginosa-Isolaten sein.

  18. Effect of Shear Stress on Pseudomonas aeruginosa Isolated from the Cystic Fibrosis Lung

    PubMed Central

    Dingemans, Jozef; Monsieurs, Pieter; Yu, Sung-Huan; Crabbé, Aurélie; Förstner, Konrad U.; Malfroot, Anne

    2016-01-01

    ABSTRACT Chronic colonization of the lungs by Pseudomonas aeruginosa is one of the major causes of morbidity and mortality in cystic fibrosis (CF) patients. To gain insights into the characteristic biofilm phenotype of P. aeruginosa in the CF lungs, mimicking the CF lung environment is critical. We previously showed that growth of the non-CF-adapted P. aeruginosa PAO1 strain in a rotating wall vessel, a device that simulates the low fluid shear (LS) conditions present in the CF lung, leads to the formation of in-suspension, self-aggregating biofilms. In the present study, we determined the phenotypic and transcriptomic changes associated with the growth of a highly adapted, transmissible P. aeruginosa CF strain in artificial sputum medium under LS conditions. Robust self-aggregating biofilms were observed only under LS conditions. Growth under LS conditions resulted in the upregulation of genes involved in stress response, alginate biosynthesis, denitrification, glycine betaine biosynthesis, glycerol metabolism, and cell shape maintenance, while genes involved in phenazine biosynthesis, type VI secretion, and multidrug efflux were downregulated. In addition, a number of small RNAs appeared to be involved in the response to shear stress. Finally, quorum sensing was found to be slightly but significantly affected by shear stress, resulting in higher production of autoinducer molecules during growth under high fluid shear (HS) conditions. In summary, our study revealed a way to modulate the behavior of a highly adapted P. aeruginosa CF strain by means of introducing shear stress, driving it from a biofilm lifestyle to a more planktonic lifestyle. PMID:27486191

  19. Unraveling genomic and phenotypic nature of multidrug-resistant (MDR) Pseudomonas aeruginosa VRFPA04 isolated from keratitis patient.

    PubMed

    N, Murugan; J, Malathi; V, Umashankar; H N, Madhavan

    2016-12-01

    Multidrug-resistant (MDR) Pseudomonas aeruginosa VRFPA04, obtained from a keratitis patient was found to exhibit resistance to betalactam (Penicillins, cephalosporins, including carbapenems, except aztreonam), aminoglycosides, quinolone group of drugs and susceptible to colistin. The complete genome sequencing of the ocular isolate to measure and ascertain the degree of multidrug resistance in VRFPA04 strain resulted in 6,818,030bp (6.8Mb) genome sizes, which happen to be the third largest genome available in the Genbank to date. Two chromosomally integrated class I integrons carrying blaVIM-2 carbapenemase gene, multiple secretory systems consisting of types I-VI and VIII proteins and ocular virulence factors exo-T, Y, U and exotoxin A, a gene that inhibits protein synthesis which could have caused corneal cell death and Phytohormone auxin biosynthetic protein were detected in the genome of VRFPA04 Genome. In addition, 58 Regions of Genomic Plasticity (RGPs) regions, multiple phage genomes, genomic islands, CRISPR genes and RND family efflux pumps, such as MexCD-OprJ and MexEF-OprN and its regulators, MexT and MexR, were unraveled in VRFPA04. Thus, the current study reveals the virulence factors and resistome nature of an ocular isolate P aeruginosa VRFPA04 genome.

  20. Isolation and characterization of a Pseudomonas aeruginosa from a virgin Brazilian Amazon region with potential to degrade atrazine.

    PubMed

    Fernandes, Ana Flavia Tonelli; da Silva, Michelle Barbosa Partata; Martins, Vinicius Vicente; Miranda, Carlos Eduardo Saraiva; Stehling, Eliana Guedes

    2014-12-01

    The use of pesticides to increase agricultural production can result in the contamination of the environment, causing changes in the genetic structure of organisms and in the loss of biodiversity. This practice is also inducing changes in the rainforest ecosystem. In this work, a Pseudomonas aeruginosa isolated from a preservation soil area of the Brazilian Amazon Forest, without usage of any pesticide, was evaluated for its potential to degrade atrazine. This isolate presented all responsible genes (atzA, atzB, atzC, atzD, atzE, and atzF) for atrazine mineralization and demonstrated capacity to use atrazine as a nitrogen source, having achieved a reduction of 44 % of the initial concentration of atrazine after 24 h. These results confirm gene dispersion and/or a possible contamination of the area with the herbicide, which reinforces global concern of the increase and intensive use of pesticides worldwide.

  1. Further Increases in Carbapenem-, Amikacin-, and Fluoroquinolone-Resistant Isolates of Acinetobacter spp. and P. aeruginosa in Korea: KONSAR Study 2009

    PubMed Central

    Lee, Kyungwon; Kim, Mi-Na; Kim, Jae-Seok; Hong, Hye Lim; Kang, Jung Oak; Shin, Jong Hee; Park, Yeon-Joon; Yong, Dongeun; Jeong, Seok Hoon

    2011-01-01

    Purpose The increasing prevalence of antimicrobial resistant bacteria has become a serious worldwide problem. The aim of this study was to analyze antimicrobial resistance data generated in 2009 by hospitals and commercial laboratories participating in the Korean Nationwide Surveillance of Antimicrobial Resistance program. Materials and Methods Susceptibility data were collected from 24 hospitals and two commercial laboratories. In the analysis, resistance did not include intermediate susceptibility. Duplicate isolates were excluded from the analysis of hospital isolates, but not from the commercial laboratory isolates. Results Among the hospital isolates, methicillin-resistant Staphylococcus aureus, penicillin G-non-susceptible Streptococcus pneumoniae based on meningitis breakpoint, and ampicillin-resistant Enterococcus faecium remained highly prevalent. The proportion of vancomycin-resistant E. faecium gradually increased to 29%. Ceftazidime-resistant Escherichia coli and Klebsiella pneumoniae increased to 17% and 33%, respectively, and fluoroquinolone-resistant K. pneumoniae, Acinetobacter spp. and Pseudomonas aeruginosa increased to 33%, 67% and 39%, respectively. Amikacin-resistant Acinetobacter spp. increased to 48%. Imipenem-resistant Acinetobacter spp. and P. aeruginosa increased to 51% and 26%, respectively. Higher resistance rates were observed in intensive care unit (ICU) isolates than in non-ICU isolates among the isolates from hospitals. Resistance rates were higher in hospital isolates than in clinic isolates among the isolates from commercial laboratories. Conclusion Among the hospital isolates, ceftazidime-resistant K. pneumoniae and fluoroquinolone-resistant K. pneumoniae, Acinetobacter spp., and P. aeruginosa further increased. The increase in imipenem resistance was slight in P. aeruginosa, but drastic in Acinetobacter spp. The problematic antimicrobial-organism combinations were much more prevalent among ICU isolates. PMID:21786445

  2. Mutations in β-Lactamase AmpC Increase Resistance of Pseudomonas aeruginosa Isolates to Antipseudomonal Cephalosporins

    PubMed Central

    Berrazeg, M.; Jeannot, K.; Ntsogo Enguéné, Véronique Yvette; Broutin, I.; Loeffert, S.; Fournier, D.

    2015-01-01

    Mutation-dependent overproduction of intrinsic β-lactamase AmpC is considered the main cause of resistance of clinical strains of Pseudomonas aeruginosa to antipseudomonal penicillins and cephalosporins. Analysis of 31 AmpC-overproducing clinical isolates exhibiting a greater resistance to ceftazidime than to piperacillin-tazobactam revealed the presence of 17 mutations in the β-lactamase, combined with various polymorphic amino acid substitutions. When overexpressed in AmpC-deficient P. aeruginosa 4098, the genes coding for 20/23 of these AmpC variants were found to confer a higher (2-fold to >64-fold) resistance to ceftazidime and ceftolozane-tazobactam than did the gene from reference strain PAO1. The mutations had variable effects on the MICs of ticarcillin, piperacillin-tazobactam, aztreonam, and cefepime. Depending on their location in the AmpC structure and their impact on β-lactam MICs, they could be assigned to 4 distinct groups. Most of the mutations affecting the omega loop, the R2 domain, and the C-terminal end of the protein were shared with extended-spectrum AmpCs (ESACs) from other Gram-negative species. Interestingly, two new mutations (F121L and P154L) were predicted to enlarge the substrate binding pocket by disrupting the stacking between residues F121 and P154. We also found that the reported ESACs emerged locally in a variety of clones, some of which are epidemic and did not require hypermutability. Taken together, our results show that P. aeruginosa is able to adapt to efficacious β-lactams, including the newer cephalosporin ceftolozane, through a variety of mutations affecting its intrinsic β-lactamase, AmpC. Data suggest that the rates of ESAC-producing mutants are ≥1.5% in the clinical setting. PMID:26248364

  3. NET formation induced by Pseudomonas aeruginosa cystic fibrosis isolates measured as release of myeloperoxidase-DNA and neutrophil elastase-DNA complexes.

    PubMed

    Yoo, Dae-goon; Floyd, Madison; Winn, Matthew; Moskowitz, Samuel M; Rada, Balázs

    2014-08-01

    Cystic fibrosis (CF) airway disease is characterized by Pseudomonas aeruginosa infection and recruitment of neutrophil granulocytes. Neutrophil granule components (myeloperoxidase (MPO), human neutrophil elastase (HNE)), extracellular DNA and P. aeruginosa can all be found in the CF respiratory tract and have all been associated with worsening CF lung function. Pseudomonas-induced formation of neutrophil extracellular traps (NETs) offers a likely mechanism for release of MPO, HNE and DNA from neutrophils. NETs are composed of a DNA backbone decorated with granule proteins like MPO and HNE. Here we sought to examine whether CF clinical isolates of Pseudomonas are capable of inducing NET release from human neutrophil granulocytes. We used two methods to quantify NETs. We modified a previously employed ELISA that detects MPO-DNA complexes and established a new HNE-DNA ELISA. We show that these methods reliably quantify MPO-DNA and HNE-DNA complexes, measures of NET formation. We have found that CF isolates of P. aeruginosa stimulate robust respiratory burst and NET release in human neutrophils. By comparing paired "early" and "late" bacterial isolates obtained from the same CF patient we have found that early isolates induced significantly more NET release than late isolates. Our data support that Pseudomonas-induced NET release represents an important mechanism for release of neutrophil-derived CF inflammatory mediators, and confirm that decreased induction of NET formation is required for long-term adaptation of P. aeruginosa to CF airways.

  4. Characterization of stress-responsive behavior in Pseudomonas aeruginosa PAO: isolation of Tn3-lacZYA fusions with novel damage-inducible (din) promoters.

    PubMed

    Warner-Bartnicki, A L; Miller, R V

    1992-03-01

    Although the pervasive soil and water microorganism Pseudomonas aeruginosa demonstrates heightened sensitivity to UV radiation, this species possesses a recA gene that, based on structural and functional properties, could mediate a DNA damage-responsive regulon similar to the SOS regulon of Escherichia coli. To determine whether P. aeruginosa encodes such stress-inducible genes, the response of P. aeruginosa to DNA-damaging agents including far-UV radiation (UVC) and the quinolone antimicrobial agent norfloxacin was investigated by monitoring the expression of fusions linking P. aeruginosa promoters to a beta-galactosidase reporter gene. These fusions were obtained by Tn3-HoHoI insertional mutagenesis of a P. aeruginosa genomic library. Eight different damage-inducible (din) gene fusions were isolated which lack homology to the P. aeruginosa recA gene. Expression of the three gene fusions studied, dinA::lacZYA, dinB::lacZYA, and dinC::lacZYA, increased following UVC and quinolone exposure but not following heat shock. Similar to E. coli SOS genes, the din genes were induced to different extents and with dissimilar kinetics following UVC irradiation.

  5. Characterization of stress-responsive behavior in Pseudomonas aeruginosa PAO: isolation of Tn3-lacZYA fusions with novel damage-inducible (din) promoters.

    PubMed Central

    Warner-Bartnicki, A L; Miller, R V

    1992-01-01

    Although the pervasive soil and water microorganism Pseudomonas aeruginosa demonstrates heightened sensitivity to UV radiation, this species possesses a recA gene that, based on structural and functional properties, could mediate a DNA damage-responsive regulon similar to the SOS regulon of Escherichia coli. To determine whether P. aeruginosa encodes such stress-inducible genes, the response of P. aeruginosa to DNA-damaging agents including far-UV radiation (UVC) and the quinolone antimicrobial agent norfloxacin was investigated by monitoring the expression of fusions linking P. aeruginosa promoters to a beta-galactosidase reporter gene. These fusions were obtained by Tn3-HoHoI insertional mutagenesis of a P. aeruginosa genomic library. Eight different damage-inducible (din) gene fusions were isolated which lack homology to the P. aeruginosa recA gene. Expression of the three gene fusions studied, dinA::lacZYA, dinB::lacZYA, and dinC::lacZYA, increased following UVC and quinolone exposure but not following heat shock. Similar to E. coli SOS genes, the din genes were induced to different extents and with dissimilar kinetics following UVC irradiation. PMID:1312530

  6. Biofilm formation and cellulose expression among diverse environmental Pseudomonas isolates.

    PubMed

    Ude, Susanne; Arnold, Dawn L; Moon, Christina D; Timms-Wilson, Tracey; Spiers, Andrew J

    2006-11-01

    The ability to form biofilms is seen as an increasingly important colonization strategy among both pathogenic and environmental bacteria. A survey of 185 plant-associated, phytopathogenic, soil and river Pseudomonas isolates resulted in 76% producing biofilms at the air-liquid (A-L) interface after selection in static microcosms. Considerable variation in biofilm phenotype was observed, including waxy aggregations, viscous and floccular masses, and physically cohesive biofilms with continuously varying strengths over 1500-fold. Calcofluor epifluorescent microscopy identified cellulose as the matrix component in biofilms produced by Pseudomonas asplenii, Pseudomonas corrugata, Pseudomonas fluorescens, Pseudomonas marginalis, Pseudomonas putida, Pseudomonas savastanoi and Pseudomonas syringae isolates. Cellulose expression and biofilm formation could be induced by the constitutively active WspR19 mutant of the cyclic-di-GMP-associated, GGDEF domain-containing response regulator involved in the P. fluorescens SBW25 wrinkly spreader phenotype and cellular aggregation in Pseudomonas aeruginosa PA01. WspR19 could also induce P. putida KT2440, which otherwise did not produce a biofilm or express cellulose, as well as Escherichia coli K12 and Salmonella typhimurium LT2, both of which express cellulose yet lack WspR homologues. Statistical analysis of biofilm parameters suggest that biofilm development is a more complex process than that simply described by the production of attachment and matrix components and bacterial growth. This complexity was also seen in multivariate analysis as a species-ecological habitat effect, underscoring the fact that in vitro biofilms are abstractions of those surface and volume colonization processes used by bacteria in their natural environments.

  7. Detection of KPC Carbapenemase in Pseudomonas aeruginosa Isolated From Clinical Samples Using Modified Hodge Test and Boronic Acid Phenotypic Methods and Their Comparison With the Polymerase Chain Reaction

    PubMed Central

    Falahat, Saeed; Shojapour, Mana; Sadeghi, Abdorrahim

    2016-01-01

    Background Bacterial resistance to antibiotics has become a major source of concern for public health. Pseudomonas aeruginosa strains are important opportunistic pathogens. These bacteria have a high resistance to a wide range of existing antimicrobials and antibiotics. Objectives The present study was performed to evaluate the frequency of KPC in P. aeruginosa isolated from clinical samples of educational hospitals of Arak University of Medical Sciences, using the mentioned phenotypic and genotypic methods. Materials and Methods One hundred and eight non-duplicate clinical isolates of P. aeruginosa were collected from hospitals of Arak University of Medical Sciences, Arak, Iran. Antibacterial susceptibility was determined by the disk diffusion method. KPC production was confirmed by the Modified Hodge Test (MHT), which is a phenotypic test, and combined-disk test with boronic acid and the Polymerase Chain Reaction (PCR). Results In the present study, 13 isolates (12%) of P. aeruginosa were positive for KPC, using PCR. Comparison of the two phenotypic methods used in this study showed that boronic acid is more sensitive than MHT in identification of KPC-producing strains (84.6% vs. 77%). Conclusions Utilization of reliable methods for identifying carbapenemase-producing strains and determining their antibiotic resistance pattern could have a very important role in treatment of infections caused by these strains. A substantial amount of P. aeruginosa isolated from clinical samples of hospitals in Arak (Iran) produce KPC carbapenemase. Due to their low specificity, MHT and boronic acid phenotypic methods could not completely identify KPC-producing P. aeruginosa. However, the sensitivity of boronic acid phenotypic method in detection of KPC was higher than MHT. PMID:27800140

  8. Similar frequencies of Pseudomonas aeruginosa isolates producing KPC and VIM carbapenemases in diverse genetic clones at tertiary-care hospitals in Medellín, Colombia.

    PubMed

    Vanegas, Johanna M; Cienfuegos, Astrid V; Ocampo, Ana M; López, Lucelly; del Corral, Helena; Roncancio, Gustavo; Sierra, Patricia; Echeverri-Toro, Lina; Ospina, Sigifredo; Maldonado, Natalia; Robledo, Carlos; Restrepo, Andrea; Jiménez, J Natalia

    2014-11-01

    Carbapenem-resistant Pseudomonas aeruginosa has become a serious health threat worldwide due to the limited options available for its treatment. Understanding its epidemiology contributes to the control of antibiotic resistance. The aim of this study was to describe the clinical and molecular characteristics of infections caused by carbapenem-resistant P. aeruginosa isolates in five tertiary-care hospitals in Medellín, Colombia. A cross-sectional study was conducted in five tertiary-care hospitals from June 2012 to March 2014. All hospitalized patients infected by carbapenem-resistant P. aeruginosa were included. Clinical information was obtained from medical records. Molecular analyses included PCR for detection of bla(VIM), bla(IMP), bla(NDM), bla(OXA-48), and bla(KPC) genes plus pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) for molecular typing. A total of 235 patients were enrolled: 91.1% of them were adults (n = 214), 88.1% (n = 207) had prior antibiotic use, and 14.9% (n = 35) had urinary tract infections. The bla(VIM-2) and bla(KPC-2) genes were detected in 13.6% (n = 32) and 11.5% (n = 27), respectively, of all isolates. Two isolates harbored both genes simultaneously. For KPC-producing isolates, PFGE revealed closely related strains within each hospital, and sequence types (STs) ST362 and ST235 and two new STs were found by MLST. With PFGE, VIM-producing isolates appeared highly diverse, and MLST revealed ST111 in four hospitals and five new STs. These results show that KPC-producing P. aeruginosa is currently disseminating rapidly and occurring at a frequency similar to that of VIM-producing P. aeruginosa isolates (approximately 1:1 ratio) in Medellín, Colombia. Diverse genetic backgrounds among resistant strains suggest an excessive antibiotic pressure resulting in the selection of resistant strains.

  9. Similar Frequencies of Pseudomonas aeruginosa Isolates Producing KPC and VIM Carbapenemases in Diverse Genetic Clones at Tertiary-Care Hospitals in Medellín, Colombia

    PubMed Central

    Vanegas, Johanna M.; Cienfuegos, Astrid V.; Ocampo, Ana M.; López, Lucelly; del Corral, Helena; Roncancio, Gustavo; Sierra, Patricia; Echeverri-Toro, Lina; Ospina, Sigifredo; Maldonado, Natalia; Robledo, Carlos; Restrepo, Andrea

    2014-01-01

    Carbapenem-resistant Pseudomonas aeruginosa has become a serious health threat worldwide due to the limited options available for its treatment. Understanding its epidemiology contributes to the control of antibiotic resistance. The aim of this study was to describe the clinical and molecular characteristics of infections caused by carbapenem-resistant P. aeruginosa isolates in five tertiary-care hospitals in Medellín, Colombia. A cross-sectional study was conducted in five tertiary-care hospitals from June 2012 to March 2014. All hospitalized patients infected by carbapenem-resistant P. aeruginosa were included. Clinical information was obtained from medical records. Molecular analyses included PCR for detection of blaVIM, blaIMP, blaNDM, blaOXA-48, and blaKPC genes plus pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) for molecular typing. A total of 235 patients were enrolled: 91.1% of them were adults (n = 214), 88.1% (n = 207) had prior antibiotic use, and 14.9% (n = 35) had urinary tract infections. The blaVIM-2 and blaKPC-2 genes were detected in 13.6% (n = 32) and 11.5% (n = 27), respectively, of all isolates. Two isolates harbored both genes simultaneously. For KPC-producing isolates, PFGE revealed closely related strains within each hospital, and sequence types (STs) ST362 and ST235 and two new STs were found by MLST. With PFGE, VIM-producing isolates appeared highly diverse, and MLST revealed ST111 in four hospitals and five new STs. These results show that KPC-producing P. aeruginosa is currently disseminating rapidly and occurring at a frequency similar to that of VIM-producing P. aeruginosa isolates (approximately 1:1 ratio) in Medellín, Colombia. Diverse genetic backgrounds among resistant strains suggest an excessive antibiotic pressure resulting in the selection of resistant strains. PMID:25210071

  10. Application of Whole-Genome Sequencing Data for O-Specific Antigen Analysis and In Silico Serotyping of Pseudomonas aeruginosa Isolates

    PubMed Central

    Thrane, Sandra Wingaard; Taylor, Véronique L.; Lund, Ole

    2016-01-01

    Accurate typing methods are required for efficient infection control. The emergence of whole-genome sequencing (WGS) technologies has enabled the development of genome-based methods applicable for routine typing and surveillance of bacterial pathogens. In this study, we developed the Pseudomonas aeruginosa serotyper (PAst) program, which enabled in silico serotyping of P. aeruginosa isolates using WGS data. PAst has been made publically available as a web service and aptly facilitates high-throughput serotyping analysis. The program overcomes critical issues such as the loss of in vitro typeability often associated with P. aeruginosa isolates from chronic infections and quickly determines the serogroup of an isolate based on the sequence of the O-specific antigen (OSA) gene cluster. Here, PAst analysis of 1,649 genomes resulted in successful serogroup assignments in 99.27% of the cases. This frequency is rarely achievable by conventional serotyping methods. The limited number of nontypeable isolates found using PAst was the result of either a complete absence of OSA genes in the genomes or the artifact of genomic misassembly. With PAst, P. aeruginosa serotype data can be obtained from WGS information alone. PAst is a highly efficient alternative to conventional serotyping methods in relation to outbreak surveillance of serotype O12 and other high-risk clones, while maintaining backward compatibility to historical serotype data. PMID:27098958

  11. [The experience of implementation of REP-u RAPD-polymerase chain reaction in epidemiologic characteristic of nosocomial isolates Pseudomonas aeruginosa].

    PubMed

    Kuznetsova, M V; Maksimova, A V; Karpunina, T I

    2015-03-01

    The article presents comparative evaluation of diagnostic value of technique REP- u RAPD-polymerase chain reaction applied under genetic typing of clinical isolates of Pseudomonas Aeruginosa. The strains are isolated in different hospital departments of medical institutions in adult (8 medical institutions; n = 145) and children (5 medical institutions; n = 151) medical networks. The results of study demonstrated different boundary capacity of three reactions. The Simpson discrimination index made up to 0.993, 0.875 and 0.639 for RAPD-, ERIC- and BOX-polymerase chain reaction correspondingly. The RAPD-polymerase chain reaction makes it possible to detect individual characteristics of strains. Out of two alternatives the REP-polymerase chain reaction demonstrated its advantage, besides only with one primer ERIC2. The BOX-polymerase chain reaction has a least discriminating capacity under typing of isolates P. aeruginosa, detecting only species' characteristics. The clinical strains P. aeruginosa are distributed on 24 genome groups and 52 isolates had individual genotypes. The evaluation of results of genetic typing permitted to point out both similarity of tendencies in propagation of strains of P. aeruginosa among hospitalized adults and adolescents and specificity of detection in neonatal clinics. It is obvious that hospitals of different profiles, including departments of reanimation and intensive therapy represent specific ecological environment significantly different in its level of endogenous and exogenous infection.

  12. Phenol degrading ability of Rhodococcus pyrinidivorans and Pseudomonas aeruginosa isolated from activated sludge plants in South Africa.

    PubMed

    Kumari, Sheena; Chetty, Dereshen; Ramdhani, Nishani; Bux, Faizal

    2013-01-01

    Phenol, a common constituent in many industrial wastewaters is a major pollutant and has several adverse effects on the environment. The potential of various microorganisms to utilize phenol for their metabolic activity has been observed to be an effective means of remediating this toxic compound from the environment particularly wastewater. Five indigenous bacterial isolates (PD1-PD5) were obtained from phenol bearing industrial wastewater using the mineral salts medium. The isolates were further characterized based on their morphology, biochemical reactions and 16S rRNA phylogeny. The 16S rRNA sequence analysis using universal primers (27f/1492r) revealed that PD1, PD2, PD3 and PD4 were closely related to the actinomycete Rhodococcus pyrinidivorans (99%) and PD5 to Pseudomonas aeruginosa (99%). Growth kinetic patterns and phenol degradation abilities of the two representative isolates (PD1 and PD5) were also evaluated. Both the species were effective in utilizing phenol as the sole carbon source and could tolerate phenol concentrations of up to 500 to 600 mg/L. The ability of these isolates to utilize higher concentrations of phenol as their sole carbon source makes them potential candidates and better competitors in the bioremediation process.

  13. Waste Isolation Pilot Plant Environmental Monitoring Plan

    SciTech Connect

    Westinghouse Electric Company Waste Isolation Division

    1999-09-29

    DOE Order 5400.1, General Environmental Protection Program Requirements (DOE, 1990a), requires each DOE facility to prepare an EMP. This document is prepared for WIPP in accordance with the guidance contained in DOE Order 5400.1; DOE Order 5400.5, Radiation Protection of the Public and Environment (DOE, 1990b); Environmental Regulatory Guide for Radiological Effluent Monitoring and Environmental Surveillance (DOE/EH-0173T; DOE, 1991); and the Title 10 Code of Federal Regulations (CFR) 834, Radiation Protection of the Public and Environment (Draft). Many sections of DOE Order 5400.1 have been replaced by DOE Order 231.1 (DOE, 1995), which is the driver for the Annual Site Environmental Report (ASER) and the guidance source for preparing many environmental program documents. The WIPP project is operated by Westinghouse Electric Company, Waste Isolation Division (WID), for the DOE. This plan defines the extent and scope of the WIPP's effluent and environmental monitoring programs during the facility's operational life and also discusses the WIPP's quality assurance/quality control (QA/QC) program as it relates to environmental monitoring. In addition, this plan provides a comprehensive description of environmental activities at WIPP including: A summary of environmental programs, including the status of environmental monitoring activities A description of the WIPP project and its mission A description of the local environment, including demographics An overview of the methodology used to assess radiological consequences to the public, including brief discussions of potential exposure pathways, routine and accidental releases, and their consequences Responses to the requirements described in the Environmental Regulatory Guide for Radiological Effluent Monitoring and Environmental Surveillance (DOE, 1991). This document references DOE orders and other federal and state regulations affecting environmental monitoring programs at the site. WIPP procedures, which implement

  14. Bdellovibrio bacteriovorus directly attacks Pseudomonas aeruginosa and Staphylococcus aureus Cystic fibrosis isolates.

    PubMed

    Iebba, Valerio; Totino, Valentina; Santangelo, Floriana; Gagliardi, Antonella; Ciotoli, Luana; Virga, Alessandra; Ambrosi, Cecilia; Pompili, Monica; De Biase, Riccardo V; Selan, Laura; Artini, Marco; Pantanella, Fabrizio; Mura, Francesco; Passariello, Claudio; Nicoletti, Mauro; Nencioni, Lucia; Trancassini, Maria; Quattrucci, Serena; Schippa, Serena

    2014-01-01

    Bdellovibrio bacteriovorus is a predator bacterial species found in the environment and within the human gut, able to attack Gram-negative prey. Cystic fibrosis (CF) is a genetic disease which usually presents lung colonization by Pseudomonas aeruginosa or Staphylococcus aureus biofilms. Here, we investigated the predatory behavior of B. bacteriovorus against these two pathogenic species with: (1) broth culture; (2) "static" biofilms; (3) field emission scanning electron microscope (FESEM); (4) "flow" biofilms; (5) zymographic technique. We had the first evidence of B. bacteriovorus survival with a Gram-positive prey, revealing a direct cell-to-cell contact with S. aureus and a new "epibiotic" foraging strategy imaged with FESEM. Mean attaching time of HD100 to S. aureus cells was 185 s, while "static" and "flow" S. aureus biofilms were reduced by 74 (at 24 h) and 46% (at 20 h), respectively. Furthermore, zymograms showed a differential bacteriolytic activity exerted by the B. bacteriovorus lysates on P. aeruginosa and S. aureus. The dual foraging system against Gram-negative (periplasmic) and Gram-positive (epibiotic) prey could suggest the use of B. bacteriovorus as a "living antibiotic" in CF, even if further studies are required to simulate its in vivo predatory behavior.

  15. Antimicrobial Activity of Ceftolozane-Tazobactam Tested against Enterobacteriaceae and Pseudomonas aeruginosa with Various Resistance Patterns Isolated in U.S. Hospitals (2011-2012)

    PubMed Central

    Flamm, Robert K.; Sader, Helio S.; Jones, Ronald N.

    2013-01-01

    Ceftolozane/tazobactam, a novel antimicrobial agent with activity against Pseudomonas aeruginosa (including drug-resistant strains) and other common Gram-negative pathogens (including most extended-spectrum-β-lactamase [ESBL]-producing Enterobacteriaceae strains), and comparator agents were susceptibility tested by a reference broth microdilution method against 7,071 Enterobacteriaceae and 1,971 P. aeruginosa isolates. Isolates were collected consecutively from patients in 32 medical centers across the United States during 2011 to 2012. Overall, 15.7% and 8.9% of P. aeruginosa isolates were classified as multidrug resistant (MDR) and extensively drug resistant (XDR), and 8.4% and 1.2% of Enterobacteriaceae were classified as MDR and XDR. No pandrug-resistant (PDR) Enterobacteriaceae isolates and only one PDR P. aeruginosa isolate were detected. Ceftolozane/tazobactam was the most potent (MIC50/90, 0.5/2 μg/ml) agent tested against P. aeruginosa and demonstrated good activity against 310 MDR strains (MIC50/90, 2/8 μg/ml) and 175 XDR strains (MIC50/90, 4/16 μg/ml). Ceftolozane/tazobactam exhibited high overall activity (MIC50/90, 0.25/1 μg/ml) against Enterobacteriaceae and retained activity (MIC50/90, 4/>32 μg/ml) against many 601 MDR strains but not against the 86 XDR strains (MIC50, >32 μg/ml). Ceftolozane/tazobactam was highly potent (MIC50/90, 0.25/0.5 μg/ml) against 2,691 Escherichia coli isolates and retained good activity against most ESBL-phenotype E. coli isolates (MIC50/90, 0.5/4 μg/ml), but activity was low against ESBL-phenotype Klebsiella pneumoniae isolates (MIC50/90, 32/>32 μg/ml), explained by the high rate (39.8%) of meropenem coresistance observed in this species phenotype. In summary, ceftolozane/tazobactam demonstrated high potency and broad-spectrum activity against many contemporary Enterobacteriaceae and P. aeruginosa isolates collected in U.S. medical centers. Importantly, ceftolozane/tazobactam retained potency against many MDR and

  16. In Vitro Activity of Ceftazidime-Avibactam against Contemporary Pseudomonas aeruginosa Isolates from U.S. Medical Centers by Census Region, 2014.

    PubMed

    Huband, Michael D; Castanheira, Mariana; Flamm, Robert K; Farrell, David J; Jones, Ronald N; Sader, Helio S

    2016-04-01

    Thein vitroantibacterial activities of ceftazidime-avibactam and comparator agents were evaluated using reference broth microdilution methods against 1,743Pseudomonas aeruginosaisolates collected in 2014 from 69 U.S. medical centers, representing each of the nine census regions. Ceftazidime-avibactam demonstrated potent activity againstP. aeruginosa, including many isolates not susceptible to ceftazidime, meropenem, and piperacillin-tazobactam. In each of the nine census regions, ceftazidime-avibactam demonstrated the highest percentage of susceptible isolates.

  17. Metallo-β-Lactamase Gene blaIMP-15 in a Class 1 Integron, In95, from Pseudomonas aeruginosa Clinical Isolates from a Hospital in Mexico▿

    PubMed Central

    Garza-Ramos, U.; Morfin-Otero, R.; Sader, H. S.; Jones, R. N.; Hernández, E.; Rodriguez-Noriega, E.; Sanchez, A.; Carrillo, B.; Esparza-Ahumada, S.; Silva-Sanchez, J.

    2008-01-01

    During 2003, 40 carbapenem-resistant Pseudomonas aeruginosa clinical isolates collected in a Mexican tertiary-care hospital were screened for metallo-β-lactamase production. Thirteen isolates produced IMP-15, and 12 had a single pulsed-field gel electrophoresis pattern. The blaIMP-15 gene cassette was inserted in a plasmid-borne integron with a unique array of gene cassettes and was named In95. PMID:18490501

  18. Genetic analyses of Pseudomonas aeruginosa isolated from healthy captive snakes: evidence of high inter- and intrasite dissemination and occurrence of antibiotic resistance genes.

    PubMed

    Colinon, Céline; Jocktane, Dominique; Brothier, Elisabeth; Rossolini, Gian Maria; Cournoyer, Benoit; Nazaret, Sylvie

    2010-03-01

    Faecal carriage of Pseudomonas aeruginosa was investigated by selective plating and PCR identification test, among healthy captive snakes from zoological and private collections from France as well as from wild snakes from Guinea. P. aeruginosa faecal carriage among captive snakes was high (72 out of 83 individuals), but low among wild specimen (3 out of 23 individuals). Genetic diversity analyses of the isolates, based on SpeI-PFGE profiles, evidenced five dominant clones or clonal complexes spreading among snakes within a site and between sites and persisting over time. Similar clones or clonal complexes were detected from mouth swabs of the owners and from water and preys used to feed the snakes, evidencing various sources of snake colonization and the first cases of P. aeruginosa cross-contamination between snakes and owners. These observations led to the conclusion that P. aeruginosa behaves as an opportunistic species within snakes in captivity and that colonization and dissemination occurs consecutively to processes similar to those identified within the hospital. Antibiotic susceptibility testing showed that most isolates had a wild-type resistance profile except for one persistent clone isolated from both snakes and preys that harboured multiple antimicrobial resistance genes mediated by an integron carrying the qacH, aadB, aadA2 and cmlA10 cassettes, and a tetA(C)-carrying transposon. Biocides or antibiotics used in the zoological garden could have led to the acquisition of this integron.

  19. Biofilm Filtrates of Pseudomonas aeruginosa Strains Isolated from Cystic Fibrosis Patients Inhibit Preformed Aspergillus fumigatus Biofilms via Apoptosis

    PubMed Central

    Shirazi, Fazal; Ferreira, Jose A. G.; Stevens, David A.; Clemons, Karl V.; Kontoyiannis, Dimitrios P.

    2016-01-01

    Pseudomonas aeruginosa (Pa) and Aspergillus fumigatus (Af) colonize cystic fibrosis (CF) patient airways. Pa culture filtrates inhibit Af biofilms, and Pa non-CF, mucoid (Muc-CF) and nonmucoid CF (NMuc-CF) isolates form an ascending inhibitory hierarchy. We hypothesized this activity is mediated through apoptosis induction. One Af and three Pa (non-CF, Muc-CF, NMuc-CF) reference isolates were studied. Af biofilm was formed in 96 well plates for 16 h ± Pa biofilm filtrates. After 24 h, apoptosis was characterized by viability dye DiBAc, reactive oxygen species (ROS) generation, mitochondrial membrane depolarization, DNA fragmentation and metacaspase activity. Muc-CF and NMuc-CF filtrates inhibited and damaged Af biofilm (p<0.0001). Intracellular ROS levels were elevated (p<0.001) in NMuc-CF-treated Af biofilms (3.7- fold) compared to treatment with filtrates from Muc-CF- (2.5- fold) or non-CF Pa (1.7- fold). Depolarization of mitochondrial potential was greater upon exposure to NMuc-CF (2.4-fold) compared to Muc-CF (1.8-fold) or non-CF (1.25-fold) (p<0.0001) filtrates. Exposure to filtrates resulted in more DNA fragmentation in Af biofilm, compared to control, mediated by metacaspase activation. In conclusion, filtrates from CF-Pa isolates were more inhibitory against Af biofilms than from non-CF. The apoptotic effect involves mitochondrial membrane damage associated with metacaspase activation. PMID:26930399

  20. Biofilm Filtrates of Pseudomonas aeruginosa Strains Isolated from Cystic Fibrosis Patients Inhibit Preformed Aspergillus fumigatus Biofilms via Apoptosis.

    PubMed

    Shirazi, Fazal; Ferreira, Jose A G; Stevens, David A; Clemons, Karl V; Kontoyiannis, Dimitrios P

    2016-01-01

    Pseudomonas aeruginosa (Pa) and Aspergillus fumigatus (Af) colonize cystic fibrosis (CF) patient airways. Pa culture filtrates inhibit Af biofilms, and Pa non-CF, mucoid (Muc-CF) and nonmucoid CF (NMuc-CF) isolates form an ascending inhibitory hierarchy. We hypothesized this activity is mediated through apoptosis induction. One Af and three Pa (non-CF, Muc-CF, NMuc-CF) reference isolates were studied. Af biofilm was formed in 96 well plates for 16 h ± Pa biofilm filtrates. After 24 h, apoptosis was characterized by viability dye DiBAc, reactive oxygen species (ROS) generation, mitochondrial membrane depolarization, DNA fragmentation and metacaspase activity. Muc-CF and NMuc-CF filtrates inhibited and damaged Af biofilm (p<0.0001). Intracellular ROS levels were elevated (p<0.001) in NMuc-CF-treated Af biofilms (3.7- fold) compared to treatment with filtrates from Muc-CF- (2.5- fold) or non-CF Pa (1.7- fold). Depolarization of mitochondrial potential was greater upon exposure to NMuc-CF (2.4-fold) compared to Muc-CF (1.8-fold) or non-CF (1.25-fold) (p<0.0001) filtrates. Exposure to filtrates resulted in more DNA fragmentation in Af biofilm, compared to control, mediated by metacaspase activation. In conclusion, filtrates from CF-Pa isolates were more inhibitory against Af biofilms than from non-CF. The apoptotic effect involves mitochondrial membrane damage associated with metacaspase activation.

  1. [Prevalence of Acinetobacter baumannii and Pseudomonas aeruginosa isolates resistant to imipenem by production of metallo-β-lactamases in Rabat Military Teaching Hospital Mohammed V].

    PubMed

    Gildas Comlan Zohoun, Alban; Moket, Danièle; El Hamzaoui, Sakina

    2013-01-01

    We studied the production of metallo-β-lactamases (MBL) in Acinetobacter baumannii and Pseudomonas aeruginosa strains resistant to imipenem at the Rabat Mohammed V military teaching hospital, according to Yong et al.'s method, using a sterilized solution of EDTA 0.5 M pH 8. One hundred and five bacterial strains (48 A. baumannii and 57 P. aeruginosa) were identified. 45 (42.9%) with 34 A. baumannii and 11 P. aeruginosa were resistant to imipenem. The prevalence of MBL producing strains was 22.2% (10/45). The existence of this isolates resistant to imipenem by producing metallo-β-lactamases is an emerging public health problem. It is necessary to implemente infection control programs to avoid spreading of multidrug resistant bacteria.

  2. Chemical alterations in cell envelopes of polymyxin-resistant Pseudomonas aeruginosa isolates.

    PubMed Central

    Gilleland, H E; Lyle, R D

    1979-01-01

    Cell envelopes from Pseudomonas aeruginosa strains resistant to polymyxin were compared with cell envelopes from polymyxin-sensitive strains as to their content of total protein, carbohydrate, and 2-keto-3-deoxyoctonate and as to their protein composition as determined by slab polyacrylamide gel electrophoresis. The cell envelopes of the polymyxin-resistant strains had reduced amounts of lipopolysaccharide, as indicated a reduction in both carbohydrate and 2-keto-3-deoxyoctonate concentrations, and a greatly altered protein composition as shown by polyacrylamide gel electrophoresis. There was a quantitative increase in total cell envelop protein in these strains. However, those protein bands identified as being major outer membrane proteins upon polyacrylamide gel electrophoresis of separated outer and cytoplasmic membranes were reduced greatly in concentration in the polymyxin-resistant cell envelopes. Thus, it appears that polymyxin resistance in these strains is associated with the alteration of the outer membrane through a loss of lipopolysaccharide and outer membrane proteins. Images PMID:222726

  3. Isolation and characterization of an alginase from mucoid strains of Pseudomonas aeruginosa.

    PubMed

    Linker, A; Evans, L R

    1984-09-01

    Strains of Pseudomonas aeruginosa which produce an alginate-like slime polysaccharide were shown to also synthesize an intracellular enzyme which can degrade these polysaccharides and the seaweed alginic acids. The enzyme acts as an eliminase introducing delta 4,5 unsaturation into the uronic acid moiety. It appears to be a polymannuronide lyase which degrades the polysaccharides, depending on their uronic acid composition, to a series of oligosaccharides, the smallest of which is a disaccharide. L-Guluronic acid linkages are not split. The Pseudomonas alginase resembles other bacterial alginases and enzymes from molluscs but differs in some important properties, such as extent of degradation and linkage preference. Nonmucoid forms of the organism produce detectable but much lower amounts of enzyme.

  4. Adhesive Capabilities of Staphylococcus Aureus and Pseudomonas Aeruginosa Isolated from Tears of HIV/AIDS Patients to Soft Contact Lenses

    PubMed Central

    B. O., Ajayi; F.E., Kio; F.D., Otajevwo

    2012-01-01

    Fifty conjunctival swab samples collected from ELISA confirmed HIV/AIDS seropositive patients who were referred to the HIV/AIDS laboratories of the University of Benin Teaching Hospital and Central Hospital both based in Benin City, Nigeria were aseptically cultured on appropriate media by standard methods. The resulting isolates/strains, after identification by standard methods, were tested for their ability to adhere to two hydrophobic non-ionic daily wear silicone hydrogel soft contact lenses (i.e. lotrafilcon B, WC 33% and polymacon, WC 38%) as well as to two hydrophilic ionic conventional extended wear silicone hydrogel soft contact lenses (i.e. methafilcon A, WC 55% and omafilcon A, WC 60%) by the adhesiveness/slime production modified vortex/Robin device method. Evidence of adhesiveness/slime production was indicated by presence of a visible stained film lining the surface of the contact lens which was measured and recorded as strong or weak according to the density of the adhered bacterial film. Fourteen (28.0%) Staphylococcus aureus strains and 10 (20.0%) Pseudomonas aeruginosa strains were obtained among other organisms. Staphylococcus aureus strains adhered in decreasing order to lotrafilcon B (55.4 ± 4.7), polymacon (46.4 ± 8.4), methfilcon A (46.4 ± 8.4) and omafilcon A (25.0 ± 6.4) with no significant difference in adhesive strengths of individual strains (P > 0.05). Pseudomonas aeruginosa strains also recorded decreasing adhesive strengths to lotrafilcon B (37.5 ± 8.2), polymacon (28.6 ± 6.3), methafilcon A (26.8 ± 5.5) and omafilcon A (23.2 ± 5.5) also with no significant difference in adhesive strengths of individual strains (P > 0.05). Attachment strengths of Staph. aureus strains to all four contact lenses were higher than those of Pseudomonas aeruginosa strains. Both organisms adhered most to hydrophobic lotrafilcon B and least to hydrophilic omafilcon A. This invitro adhesion studies revealed that daily wear silicone hydrogel low water

  5. Antimicrobial potentials of Helicteres isora silver nanoparticles against extensively drug-resistant (XDR) clinical isolates of Pseudomonas aeruginosa.

    PubMed

    Mapara, Nikunj; Sharma, Mansi; Shriram, Varsha; Bharadwaj, Renu; Mohite, K C; Kumar, Vinay

    2015-12-01

    Pseudomonas aeruginosa is a leading opportunistic pathogen and its expanding drug resistance is a growing menace to public health. Its ubiquitous nature and multiple resistance mechanisms make it a difficult target for antimicrobial chemotherapy and require a fresh approach for developing new antimicrobial agents against it. The broad-spectrum antibacterial effects of silver nanoparticles (SNPs) make them an excellent candidate for use in the medical field. However, attempts made to check their potency against extensively drug-resistant (XDR) microbes are meager. This study describes the biosynthesis and biostabilization of SNPs by Helicteres isora aqueous fruit extract and their characterization by ultraviolet-visible spectroscopy, transmission electron microscopy, dynamic light scattering, X-ray diffraction, and Fourier transform infrared spectroscopy. Majority of SNPs synthesized were of 8--20-nm size. SNPs exhibited dose-dependent antibacterial activities against four XDR P. aeruginosa (XDR-PA) clinical isolates as revealed by growth curves, with a minimum inhibitory concentration of 300 μg/ml. The SNPs exhibited antimicrobial activity against all strains, with maximum zone of inhibition (16.4 mm) in XRD-PA-2 at 1000 μg/ml. Amongst four strains, their susceptibilities to SNPs were in the following order: XDR-PA-2 > XDR-PA-4 > XDR-PA-3 > XDR-PA-1. The exposure of bacterial cells to 300 μg/ml SNPs resulted into a substantial leakage of reducing sugars and proteins, inactivation of respiratory chain dehydrogenases, and eventual cell death. SNPs also induced lipid peroxidation, a possible underlying factor to membrane porosity. The effects were more pronounced in XDR-PA-2 which may be correlated with its higher susceptibility to SNPs. These results are indicative of SNP-induced turbulence of membranous permeability as an important causal factor in XDR-PA growth inhibition and death.

  6. Fitness Cost of Fluoroquinolone Resistance in Clinical Isolates of Pseudomonas aeruginosa Differs by Type III Secretion Genotype

    PubMed Central

    Agnello, Melissa; Finkel, Steven E.; Wong-Beringer, Annie

    2016-01-01

    Fluoroquinolone (FQ) resistance is highly prevalent among clinical strains of Pseudomonas aeruginosa, limiting treatment options. We have reported previously that highly virulent strains containing the exoU gene of the type III secretion system are more likely to be FQ-resistant than strains containing the exoS gene, as well as more likely to acquire resistance-conferring mutations in gyrA/B and parC/E. We hypothesize that FQ-resistance imposes a lower fitness cost on exoU compared to exoS strains, thus allowing for better adaptation to the FQ-rich clinical environment. We created isogenic mutants containing a common FQ-resistance conferring point mutation in parC from three exoU to three exoS clinical isolates and tested fitness in vitro using head-to-head competition assays. The mutation differentially affected fitness in the exoU and exoS strains tested. While the addition of the parC mutation dramatically increased fitness in one of the exoU strains leaving the other two unaffected, all three exoS strains displayed a general decrease in fitness. In addition, we found that exoU strains may be able to compensate for the fitness costs associated with the mutation through better regulation of supercoiling compared to the exoS strains. These results may provide a biological explanation for the observed predominance of the virulent exoU genotype in FQ-resistant clinical subpopulations and represent the first investigation into potential differences in fitness costs of FQ-resistance that are linked to the virulence genotype of P. aeruginosa. Understanding the fitness costs of antibiotic resistance and possibilities of compensation for these costs is essential for the rational development of strategies to combat the problem of antibiotic resistance. PMID:27757111

  7. Fitness Cost of Fluoroquinolone Resistance in Clinical Isolates of Pseudomonas aeruginosa Differs by Type III Secretion Genotype.

    PubMed

    Agnello, Melissa; Finkel, Steven E; Wong-Beringer, Annie

    2016-01-01

    Fluoroquinolone (FQ) resistance is highly prevalent among clinical strains of Pseudomonas aeruginosa, limiting treatment options. We have reported previously that highly virulent strains containing the exoU gene of the type III secretion system are more likely to be FQ-resistant than strains containing the exoS gene, as well as more likely to acquire resistance-conferring mutations in gyrA/B and parC/E. We hypothesize that FQ-resistance imposes a lower fitness cost on exoU compared to exoS strains, thus allowing for better adaptation to the FQ-rich clinical environment. We created isogenic mutants containing a common FQ-resistance conferring point mutation in parC from three exoU to three exoS clinical isolates and tested fitness in vitro using head-to-head competition assays. The mutation differentially affected fitness in the exoU and exoS strains tested. While the addition of the parC mutation dramatically increased fitness in one of the exoU strains leaving the other two unaffected, all three exoS strains displayed a general decrease in fitness. In addition, we found that exoU strains may be able to compensate for the fitness costs associated with the mutation through better regulation of supercoiling compared to the exoS strains. These results may provide a biological explanation for the observed predominance of the virulent exoU genotype in FQ-resistant clinical subpopulations and represent the first investigation into potential differences in fitness costs of FQ-resistance that are linked to the virulence genotype of P. aeruginosa. Understanding the fitness costs of antibiotic resistance and possibilities of compensation for these costs is essential for the rational development of strategies to combat the problem of antibiotic resistance.

  8. Co-Carriage of blaKPC-2 and blaNDM-1 in Clinical Isolates of Pseudomonas aeruginosa Associated with Hospital Infections from India.

    PubMed

    Paul, Deepjyoti; Dhar Chanda, Debadatta; Maurya, Anand Prakash; Mishra, Shweta; Chakravarty, Atanu; Sharma, Gauri Dutt; Bhattacharjee, Amitabha

    2015-01-01

    Global spread of KPC poses to be a serious threat complicating treatment options in hospital settings. The present study investigates the genetic environment of blaKPC-2 among clinical isolates of Pseudomonas aeruginosa from a tertiary referral hospital of India. The study isolates were collected from different wards and clinics of Silchar Medical College and Hospital, India, from 2012-2013. The presence of blaKPC was confirmed by genotypic characterization followed by sequencing. Cloning of the blaKPC-2 gene was performed and the genetic environment of this gene was characterized as well. Transferability of the resistance gene was determined by transformation assay and Southern hybridization. Additionally, restriction mapping was also carried out. Two isolates of P. aeruginosa were found to harbor blaKPC-2, were resistant towards aminoglycosides, quinolone and β-lactam-β-lactamase inhibitor combination. In both the isolates, the resistance determinant was associated with class 1 integron and horizontally transferable. Both the isolates were co-harboring blaNDM-1. The first detection of this integron mediated blaKPC-2 coexisting with blaNDM-1 in P. aeruginosa from India is worrisome, and further investigation is required to track the gene cassette mediated blaKPC-2 in terms of infection control and to prevent the spread of this gene in hospitals as well as in the community.

  9. Biodegradation of isoproturon using a novel Pseudomonas aeruginosa strain JS-11 as a multi-functional bioinoculant of environmental significance.

    PubMed

    Dwivedi, Sourabh; Singh, Braj Raj; Al-Khedhairy, Abdulaziz A; Musarrat, Javed

    2011-01-30

    Biodegradation of phenylurea herbicide isoproturon was studied in soil microcosm bioaugmented with a novel bacterial strain JS-11 isolated from wheat rhizosphere. The molecular characterization based on 16SrDNA sequence homology confirmed its identity as Pseudomonas aeruginosa strain JS-11. The herbicide was completely degraded within 20 days at ambient temperature with the rate constant of 0.08 day(-1), following the first-order rate kinetics. In stationary phase, at a cell density of 6.5 × 10(9) CFU mL(-1), the bacteria produced substantially increased amounts of indole acetic acid (IAA) in the presence of tryptophan as compared with the control. Also, the bacteria exhibited a time-dependent increase in the amount of tri-calcium phosphate solubilization in Pikovskaya's medium. Further screening of the strain JS-11 for auxiliary activities revealed its remarkable capability of producing the siderophores and hydrogen cyanide (HCN), besides antifungal activity against a common phytopathogen Fusarium oxysporum. Thus, the versatile P. aeruginosa strain JS-11 with innate potential for multifarious biological activities is envisaged as a super-bioinoculant for exploitation in the integrated bioremediation, plant growth and disease management (IBPDM) in contaminated agricultural soils.

  10. Antibiotic Resistance Pattern and Evaluation of Metallo-Beta Lactamase Genes Including bla- IMP and bla- VIM Types in Pseudomonas aeruginosa Isolated from Patients in Tehran Hospitals.

    PubMed

    Aghamiri, Samira; Amirmozafari, Nour; Fallah Mehrabadi, Jalil; Fouladtan, Babak; Samadi Kafil, Hossein

    2014-01-01

    Beta-lactamase producing strains of Pseudomonas aeruginosa are important etiological agents of hospital infections. Carbapenems are among the most effective antibiotics used against Pseudomonas infections, but they can be rendered infective by group B β -lactamase, commonly called metallo-beta lactamase. In this study, the antimicrobial sensitivity patterns of P. aeruginosa strains isolated from 9 different hospitals in Tehran, Iran, as well as the prevalence of MBLs genes (bla- VIM and bla- IMP ) were determined. A total of 212 strains of P. aeruginosa recovered from patients in hospitals in Tehran were confirmed by both biochemical methods and PCR. Their antimicrobial sensitivity patterns were determined by Kirby-Bauer disk diffusion method. Following MIC determination, imipenem resistant strains were selected by DDST method which was followed by PCR tests for determination of MBLs genes: bla- IMP and bla- VIM . The results indicated that, in the DDST phenotypic method, among the 100 imipenem resistant isolates, 75 strains were MBLs positive. The PCR test indicated that 70 strains (33%) carried bla- VIM gene and 20 strains (9%) harbored bla- IMP . The results indicated that the extent of antibiotic resistance among Pseudomonas aeruginosa is on the rise. This may be due to production of MBLs enzymes. Therefore, determination of antibiotic sensitivity patterns and MBLs production by these bacteria, can be important in control of clinical Pseudomonas infection.

  11. Hospital Isolates of Serratia marcescens Transferring Ampicillin, Carbenicillin, and Gentamicin Resistance to Other Gram-Negative Bacteria Including Pseudomonas aeruginosa

    PubMed Central

    Olexy, Vera M.; Bird, Thomas J.; Grieble, Hans G.; Farrand, Stephen K.

    1979-01-01

    Thirteen independent isolates of Serratia marcescens associated with nosocomial urinary tract infections were obtained from the clinical microbiology laboratory at Hines Veterans Administration Hospital. The isolates were resistant to at least ampicillin, carbenicillin, gentamicin, and tobramycin. They could be divided into two groups on the basis of their antibiotypes. Group I (9 strains) showed resistance to 13 antibiotics, including 3 beta-lactams, 6 aminoglycosides, tetracycline, sulfonamide, trimethoprim, and polymyxin B. Group II (4 strains) was resistant to 11 antibiotics, including 3 beta-lactams, 5 aminoglycosides, sulfonamide, trimethoprim, and polymyxin B. Donors from both groups transferred resistance traits to Escherichia coli. Transconjugants from matings with group II donors all acquired resistance to nine antibiotics, including the three beta-lactams, five aminoglycosides, and sulfonamide. Transconjugants from matings with group I donors were of varied antibiotypes, inheriting resistance to up to 11 of the 13 antibiotics. Resistances to trimethoprim and polymyxin B were never observed to transfer. E. coli transconjugants of each group were capable of transferring multiple-antibiotic resistance to several other members of the family Enterobacteriaceae. All group II S. marcescens and E. coli donors and all group I S. marcescens donors transferred carbenicillin, streptomycin, kanamycin, gentamicin, tobramycin, and sisomicin resistance to Pseudomonas aeruginosa. The results suggest that these S. marcescens strains harbor R factors of a broader host range than previously reported. PMID:106772

  12. Detection of extended spectrum beta lactamases, ampc beta lactamases and metallobetalactamases in clinical isolates of ceftazidime resistant Pseudomonas Aeruginosa.

    PubMed

    Umadevi, Sivaraman; Joseph, Noyal M; Kumari, Kandha; Easow, Joshy M; Kumar, Shailesh; Stephen, Selvaraj; Srirangaraj, Sreenivasan; Raj, Sruthi

    2011-10-01

    We studied the prevalence of ceftazidime resistance in Pseudomonas aeruginosa and the rates of extended-spectrum β-lactamase (ESBL), AmpC β-lactamase (AmpC) and metallo-β-lactamase (MBL) production among the ceftazidime resistant Pseudomonas aeruginosa. A very high rate of MBL production was observed, which suggested it to be an important contributing factor for ceftazidime resistance among Pseudomonas aeruginosa.

  13. SCL-LCL-PHA copolymer production by a local isolate, Pseudomonas aeruginosa MTCC 7925.

    PubMed

    Singh, Akhilesh Kumar; Mallick, Nirupama

    2009-05-01

    A five-level-four-factor central composite rotary design (CCRD) was employed in combination with response surface methodology (RSM) to optimize the process variables for the production of a novel copolymer consisting of short-chain-length (SCL) and long-chain-length (LCL) PHA units, i.e., P(3HB-3HV-3HHD-3HOD) copolymer in Pseudomonas aeruginosa MTCC 7925. The four variables involved in this study were ethanol, glucose, ammonium nitrate (NH(4)NO(3)), and potassium dihydrogen phosphate (KH(2)PO(4)). A second-order polynomial equation was obtained by multiple regression analysis using RSM. The statistical analyses of the results showed that all the four variables had significant impact on the copolymer yield. The model predicted a maximum yield of 81.1% of dry cell weight (dcw) on setting the concentrations of ethanol and glucose at 1.5 and 1.1%, and KH(2)PO(4) and NH(4)NO(3) at 2.79 and 1.86 g/L, respectively. Verification of the predicted value resulted into a yield of 77.6% (dcw). This novel copolymer exhibited comparable material properties with polypropylene (PP) and low density polyethylene (LDPE), thus advocating its potential applications in various fields.

  14. Prevalence of Extended-Spectrum and Metallo β-Lactamase Production in AmpC β-Lactamase Producing Pseudomonas aeruginosa Isolates From Burns

    PubMed Central

    Rafiee, Roya; Eftekhar, Fereshteh; Tabatabaei, Seyyed Ahmad; Minaee Tehrani, Dariush

    2014-01-01

    Background: Pseudomonas aeruginosa is one of the most common causes of nosocomial infections. Resistance of P. aeruginosa to β-lactam antibiotics may be the result of acquired resistance through mutation and over production of various antibiotic inactivating enzymes. This research aimed to determine the prevalence of extended-spectrum β-lactamases (ESBL) and metallo β-lactamase (MBL) production as well as the presence of their related genes among AmpC β-lactamase producing P. aeruginosa isolated from burns. Objectives: The current study aimed to determine the prevalence of class A ESBL and MBL production in relation to the presence of their related genes among AmpC β-lactamase producing P. aeruginosa isolated from burns. Materials and Methods: The antimicrobial susceptibility of 51 P. aeruginosa isolates from patients with burns was examined against 13 antibiotics by the disc diffusion method. Minimum inhibitory concentrations (MIC) for imipenem and ceftazidime were measured by the microdilution method. AmpC production was detected by AmpC disc and the modified three-dimensional extract tests. ESBL phenotype was confirmed by the double disc synergy test (DDST). Presence of β-lactamase genes was detected by specific primers and polymerase chain reaction (PCR). Results: All isolates were multidrug resistant. AmpC, ESBL and MBL production were observed in 35 (68.6%), 20 (39.2%) and 19 (37.3%) isolates, respectively. Overall, 43 isolates (84.3%) carried β-lactamase genes, out of which 31 (60.8%) harbored blaAmpC, 20 (39.2%) had blaTEM and 11 (21.6%) carried blaPER-1 genes. Among the AmpC producers, two isolates (6.5%) carried blaAmpC + blaESBL, 13 (41.9%) had blaAmpC + blaMBL and six (19.4%) produced the three enzymes. Conclusions: A high prevalence of multiple β-lactamase production was observed among the AmpC producers (60%), of which the majority co-produced AmpC and MBL. The current study results showed correlation between β-lactamase production and the

  15. Pharmacodynamics of Aerosolized Fosfomycin and Amikacin against Resistant Clinical Isolates of Pseudomonas aeruginosa and Klebsiella pneumoniae in a Hollow-Fiber Infection Model: Experimental Basis for Combination Therapy

    PubMed Central

    Sime, Fekade Bruck; Johnson, Adam; Whalley, Sarah; Santoyo-Castelazo, Anahi; Montgomery, A. Bruce; Walters, Kathie Ann; Lipman, Jeffrey; Hope, William W.

    2016-01-01

    ABSTRACT There has been a resurgence of interest in aerosolization of antibiotics for treatment of patients with severe pneumonia caused by multidrug-resistant pathogens. A combination formulation of amikacin-fosfomycin is currently undergoing clinical testing although the exposure-response relationships of these drugs have not been fully characterized. The aim of this study was to describe the individual and combined antibacterial effects of simulated epithelial lining fluid exposures of aerosolized amikacin and fosfomycin against resistant clinical isolates of Pseudomonas aeruginosa (MICs of 16 mg/liter and 64 mg/liter) and Klebsiella pneumoniae (MICs of 2 mg/liter and 64 mg/liter) using a dynamic hollow-fiber infection model over 7 days. Targeted peak concentrations of 300 mg/liter amikacin and/or 1,200 mg/liter fosfomycin as a 12-hourly dosing regimens were used. Quantitative cultures were performed to describe changes in concentrations of the total and resistant bacterial populations. The targeted starting inoculum was 108 CFU/ml for both strains. We observed that neither amikacin nor fosfomycin monotherapy was bactericidal against P. aeruginosa while both were associated with rapid amplification of resistant P. aeruginosa strains (about 108 to 109 CFU/ml within 24 to 48 h). For K. pneumoniae, amikacin but not fosfomycin was bactericidal. When both drugs were combined, a rapid killing was observed for P. aeruginosa and K. pneumoniae (6-log kill within 24 h). Furthermore, the combination of amikacin and fosfomycin effectively suppressed growth of resistant strains of P. aeruginosa and K. pneumoniae. In conclusion, the combination of amikacin and fosfomycin was effective at maximizing bacterial killing and suppressing emergence of resistance against these clinical isolates. PMID:27795380

  16. Mutational and acquired carbapenem resistance mechanisms in multidrug resistant Pseudomonas aeruginosa clinical isolates from Recife, Brazil

    PubMed Central

    Cavalcanti, Felipe Lira de Sá; Mirones, Cristina Rodríguez; Paucar, Elena Román; Montes, Laura Álvarez; Leal-Balbino, Tereza Cristina; de Morais, Marcia Maria Camargo; Martínez-Martínez, Luis; Ocampo-Sosa, Alain Antonio

    2015-01-01

    An investigation was carried out into the genetic mechanisms responsible for multidrug resistance in nine carbapenem-resistant Pseudomonas aeruginosaisolates from different hospitals in Recife, Brazil. Susceptibility to antimicrobial agents was determined by broth microdilution. Polymerase chain reaction (PCR) was employed to detect the presence of genes encoding β-lactamases, aminoglycoside-modifying enzymes (AMEs), 16S rRNA methylases, integron-related genes and OprD. Expression of genes coding for efflux pumps and AmpC cephalosporinase were assessed by quantitative PCR. The outer membrane proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The blaSPM-1, blaKPC-2 and blaGES-1 genes were detected in P. aeruginosaisolates in addition to different AME genes. The loss of OprD in nine isolates was mainly due to frameshift mutations, premature stop codons and point mutations. An association of loss of OprD with the overexpression of MexAB-OprM and MexXY-OprM was observed in most isolates. Hyper-production of AmpC was also observed in three isolates. Clonal relationship of the isolates was determined by repetitive element palindromic-PCR and multilocus sequence typing. Our results show that the loss of OprD along with overexpression of efflux pumps and β-lactamase production were responsible for the multidrug resistance in the isolates analysed. PMID:26676375

  17. Extensively drug-resistant pseudomonas aeruginosa isolates containing blaVIM-2 and elements of Salmonella genomic island 2: a new genetic resistance determinant in Northeast Ohio.

    PubMed

    Perez, Federico; Hujer, Andrea M; Marshall, Steven H; Ray, Amy J; Rather, Philip N; Suwantarat, Nuntra; Dumford, Donald; O'Shea, Patrick; Domitrovic, T Nicholas J; Salata, Robert A; Chavda, Kalyan D; Chen, Liang; Kreiswirth, Barry N; Vila, Alejandro J; Haussler, Susanne; Jacobs, Michael R; Bonomo, Robert A

    2014-10-01

    Carbapenems are a mainstay of treatment for infections caused by Pseudomonas aeruginosa. Carbapenem resistance mediated by metallo-β-lactamases (MBLs) remains uncommon in the United States, despite the worldwide emergence of this group of enzymes. Between March 2012 and May 2013, we detected MBL-producing P. aeruginosa in a university-affiliated health care system in northeast Ohio. We examined the clinical characteristics and outcomes of patients, defined the resistance determinants and structure of the genetic element harboring the blaMBL gene through genome sequencing, and typed MBL-producing P. aeruginosa isolates using pulsed-field gel electrophoresis (PFGE), repetitive sequence-based PCR (rep-PCR), and multilocus sequence typing (MLST). Seven patients were affected that were hospitalized at three community hospitals, a long-term-care facility, and a tertiary care center; one of the patients died as a result of infection. Isolates belonged to sequence type 233 (ST233) and were extensively drug resistant (XDR), including resistance to all fluoroquinolones, aminoglycosides, and β-lactams; two isolates were nonsusceptible to colistin. The blaMBL gene was identified as blaVIM-2 contained within a class 1 integron (In559), similar to the cassette array previously detected in isolates from Norway, Russia, Taiwan, and Chicago, IL. Genomic sequencing and assembly revealed that In559 was part of a novel 35-kb region that also included a Tn501-like transposon and Salmonella genomic island 2 (SGI2)-homologous sequences. This analysis of XDR strains producing VIM-2 from northeast Ohio revealed a novel recombination event between Salmonella and P. aeruginosa, heralding a new antibiotic resistance threat in this region's health care system.

  18. Synergistic activities of macrolide antibiotics against Pseudomonas aeruginosa, Burkholderia cepacia, Stenotrophomonas maltophilia, and Alcaligenes xylosoxidans isolated from patients with cystic fibrosis.

    PubMed

    Saiman, Lisa; Chen, Yunhua; Gabriel, Pablo San; Knirsch, Charles

    2002-04-01

    Azithromycin and clarithromycin were paired with other antibiotics to test synergistic activity against 300 multidrug-resistant pathogens isolated from cystic fibrosis (CF) patients. Clarithromycin-tobramycin was most active against Pseudomonas aeruginosa and inhibited 58% of strains. Azithromycin-trimethoprim-sulfamethoxazole, azithromycin-ceftazidime, and azithromycin-doxycycline or azithromycin-trimethoprim-sulfamethoxazole inhibited 40, 20, and 22% of Stenotrophomonas maltophilia, Burkholderia cepacia complex, and Achromobacter (Alcaligenes) xylosoxidans strains, respectively.

  19. Pseudomonas aeruginosa sepsis in stem cell transplantation patients.

    PubMed

    Fanci, Rosa; Pecile, Patrizia; Casalone, Enrico; Mengoni, Alessio; Tamburini, Elena; Guidi, Stefano; Cecconi, Daniela; Bosi, Alberto; Nicoletti, Pierluigi; Mastromei, Giorgio

    2006-07-01

    We report the epidemiological investigation of an outbreak of Pseudomonas aeruginosa infection in 6 patients who shared, during different periods, the same 2 rooms of a bone marrow transplantation unit. Phenotypic and molecular analysis of isolates from patients and from the environment strongly suggested a single, environmental source of infection.

  20. Pseudomonas aeruginosa Population Structure Revisited

    PubMed Central

    Pirnay, Jean-Paul; Bilocq, Florence; Pot, Bruno; Cornelis, Pierre; Zizi, Martin; Van Eldere, Johan; Deschaght, Pieter; Vaneechoutte, Mario; Jennes, Serge; Pitt, Tyrone; De Vos, Daniel

    2009-01-01

    At present there are strong indications that Pseudomonas aeruginosa exhibits an epidemic population structure; clinical isolates are indistinguishable from environmental isolates, and they do not exhibit a specific (disease) habitat selection. However, some important issues, such as the worldwide emergence of highly transmissible P. aeruginosa clones among cystic fibrosis (CF) patients and the spread and persistence of multidrug resistant (MDR) strains in hospital wards with high antibiotic pressure, remain contentious. To further investigate the population structure of P. aeruginosa, eight parameters were analyzed and combined for 328 unrelated isolates, collected over the last 125 years from 69 localities in 30 countries on five continents, from diverse clinical (human and animal) and environmental habitats. The analysed parameters were: i) O serotype, ii) Fluorescent Amplified-Fragment Length Polymorphism (FALFP) pattern, nucleotide sequences of outer membrane protein genes, iii) oprI, iv) oprL, v) oprD, vi) pyoverdine receptor gene profile (fpvA type and fpvB prevalence), and prevalence of vii) exoenzyme genes exoS and exoU and viii) group I pilin glycosyltransferase gene tfpO. These traits were combined and analysed using biological data analysis software and visualized in the form of a minimum spanning tree (MST). We revealed a network of relationships between all analyzed parameters and non-congruence between experiments. At the same time we observed several conserved clones, characterized by an almost identical data set. These observations confirm the nonclonal epidemic population structure of P. aeruginosa, a superficially clonal structure with frequent recombinations, in which occasionally highly successful epidemic clones arise. One of these clones is the renown and widespread MDR serotype O12 clone. On the other hand, we found no evidence for a widespread CF transmissible clone. All but one of the 43 analysed CF strains belonged to a ubiquitous P

  1. Isolation of Pseudomonas aeruginosa strains from dental office environments and units in Barretos, state of São Paulo, Brazil, and analysis of their susceptibility to antimicrobial drugs

    PubMed Central

    de Oliveira, Ana Claudia; Maluta, Renato Pariz; Stella, Ariel Eurides; Rigobelo, Everlon Cid; Marin, José Moacir; de Ávila, Fernando Antonio

    2008-01-01

    A wide variety of opportunistic pathogens has been detected in the tubing supplying water to odontological equipment, in special in the biofilm lining of these tubes. Among these pathogens, Pseudomonas aeruginosa, one of the leading causes of nosocomial infections, is frequently found in water lines supplying dental units. In the present work, 160 samples of water, and 200 fomite samples from forty dental units were collected in the city of Barretos, State of São Paulo, Brazil and evaluated between January and July, 2005. Seventy-six P. aeruginosa strains, isolated from the dental environment (5 strains) and water system (71 strains), were tested for susceptibility to six antimicrobial drugs most frequently used against P. aeruginosa infections. Susceptibility to ciprofloxacin, followed by meropenem was the predominant profile. The need for effective means of reducing the microbial burden within dental unit water lines is emphasized, and the risk of exposure and cross-infection in dental practice, in special when caused by opportunistic pathogens like P. aeruginosa, are highlighted. PMID:24031269

  2. Anti-biofilm activity of biogenic selenium nanoparticles and selenium dioxide against clinical isolates of Staphylococcus aureus, Pseudomonas aeruginosa, and Proteus mirabilis.

    PubMed

    Shakibaie, Mojtaba; Forootanfar, Hamid; Golkari, Yaser; Mohammadi-Khorsand, Tayebe; Shakibaie, Mohammad Reza

    2015-01-01

    The aim of the present study was to investigate the anti-biofilm activity of biologically synthesized selenium nanoparticles (Se NPs) against the biofilm produced by clinically isolated bacterial strains compared to that of selenium dioxide. Thirty strains of Staphylococcus aureus, Pseudomonas aeruginosa, and Proteus mirabilis were isolated from various specimens of the patients hospitalized in different hospitals (Kerman, Iran). Quantification of the biofilm using microtiter plate assay method introduced 30% of S. aureus, 13% of P. aeruginosa and 17% of P. mirabilis isolates as severely adherent strains. Transmission electron micrograph (TEM) of the purified Se NPs (produced by Bacillus sp. MSh-1) showed individual and spherical nano-structure in the size range of 80-220nm. Obtained results of the biofilm formation revealed that selenium nanoparticles inhibited the biofilm of S. aureus, P. aeruginosa, and P. mirabilis by 42%, 34.3%, and 53.4%, respectively, compared to that of the non-treated samples. Effect of temperature and pH on the biofilm formation in the presence of Se NPs and SeO2 was also evaluated.

  3. Antibacterial compound produced by Pseudomonas aeruginosa strain UICC B-40, an endophytic bacterium isolated from Neesia altissima.

    PubMed

    Pratiwi, Rina Hidayati; Hidayat, Iman; Hanafi, Muhammad; Mangunwardoyo, Wibowo

    2017-04-01

    This study's aim was to determine the identity of antibacterial compounds produced by Pseudomonas aeruginosa strain UICC B-40 and describe the antibacterial compounds' mechanisms of action for damaging pathogenic bacteria cells. Isolation and identification of the compounds were carried out using thin layer chromatography (TLC), nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography mass spectrometry (LC-MS) analyses. Antibacterial activity was assayed via minimum inhibitory concentration (MIC) and the antibacterial compound mechanism was observed morphologically through scanning electron microscopy (SEM). This study successfully identified the (2E,5E)-phenyltetradeca-2,5-dienoate antibacterial compound (molecular weight 300 g/mol), composed of a phenolic ester, fatty acid and long chain of aliphatic group structures. MIC values for this compound were determined at 62.5 μg/ml against Staphylococcus aureus strain ATCC 25923. The mechanism of the compound involved breaking down the bacterial cell walls through the lysis process. The (2E,5E)-phenyltetradeca-2,5-dienoate compound exhibited inhibitory activity on the growth of Gram-positive bacteria.

  4. Structural and physicochemical characterization of crude biosurfactant produced by Pseudomonas aeruginosa SP4 isolated from petroleum-contaminated soil.

    PubMed

    Pornsunthorntawee, Orathai; Wongpanit, Panya; Chavadej, Sumaeth; Abe, Masahiko; Rujiravanit, Ratana

    2008-04-01

    Pseudomonas aeruginosa strain SP4, isolated from petroleum-contaminated soil in Thailand, was used to produce a biosurfactant from a nutrient broth with palm oil as the carbon source. The key components of the crude biosurfactant were fractionated by using HPLC-ELSD technique. With the use of ATR-FTIR spectroscopy, in combination with (1)H NMR and MS analyses, chemical structures of the fractionated components of the crude biosurfactant were identified as rhamnolipid species. When compared to synthetic surfactants, including Pluronic F-68, which is a triblock nonionic surfactant containing poly(ethylene oxide) and poly(propylene oxide), and sodium dodecyl sulfate, the crude biosurfactant showed comparable physicochemical properties, in terms of the surface activities. The crude biosurfactant reduced the surface tension of pure water to 29.0 mN/m with a critical micelle concentration of approximately 200 mg/l, and it exhibited good thermal and pH stability. The crude biosurfactant also formed stable water-in-oil microemulsions with crude oil and various types of vegetable oils, but not with short-chain hydrocarbons.

  5. D-amino acids enhance the activity of antimicrobials against biofilms of clinical wound isolates of Staphylococcus aureus and Pseudomonas aeruginosa.

    PubMed

    Sanchez, Carlos J; Akers, Kevin S; Romano, Desiree R; Woodbury, Ronald L; Hardy, Sharanda K; Murray, Clinton K; Wenke, Joseph C

    2014-08-01

    Within wounds, microorganisms predominantly exist as biofilms. Biofilms are associated with chronic infections and represent a tremendous clinical challenge. As antibiotics are often ineffective against biofilms, use of dispersal agents as adjunctive, topical therapies for the treatment of wound infections involving biofilms has gained interest. We evaluated in vitro the dispersive activity of D-amino acids (D-AAs) on biofilms from clinical wound isolates of Staphylococcus aureus and Pseudomonas aeruginosa; moreover, we determined whether combinations of D-AAs and antibiotics (clindamycin, cefazolin, oxacillin, rifampin, and vancomycin for S. aureus and amikacin, colistin, ciprofloxacin, imipenem, and ceftazidime for P. aeruginosa) enhance activity against biofilms. D-Met, D-Phe, and D-Trp at concentrations of ≥ 5 mM effectively dispersed preformed biofilms of S. aureus and P. aeruginosa clinical isolates, an effect that was enhanced when they were combined as an equimolar mixture (D-Met/D-Phe/D-Trp). When combined with D-AAs, the activity of rifampin was significantly enhanced against biofilms of clinical isolates of S. aureus, as indicated by a reduction in the minimum biofilm inhibitory concentration (MBIC) (from 32 to 8 μg/ml) and a >2-log reduction of viable biofilm bacteria compared to treatment with antibiotic alone. The addition of D-AAs was also observed to enhance the activity of colistin and ciprofloxacin against biofilms of P. aeruginosa, reducing the observed MBIC and the number of viable bacteria by >2 logs and 1 log at 64 and 32 μg/ml in contrast to antibiotics alone. These findings indicate that the biofilm dispersal activity of D-AAs may represent an effective strategy, in combination with antimicrobials, to release bacteria from biofilms, subsequently enhancing antimicrobial activity.

  6. d-Amino Acids Enhance the Activity of Antimicrobials against Biofilms of Clinical Wound Isolates of Staphylococcus aureus and Pseudomonas aeruginosa

    PubMed Central

    Akers, Kevin S.; Romano, Desiree R.; Woodbury, Ronald L.; Hardy, Sharanda K.; Murray, Clinton K.; Wenke, Joseph C.

    2014-01-01

    Within wounds, microorganisms predominantly exist as biofilms. Biofilms are associated with chronic infections and represent a tremendous clinical challenge. As antibiotics are often ineffective against biofilms, use of dispersal agents as adjunctive, topical therapies for the treatment of wound infections involving biofilms has gained interest. We evaluated in vitro the dispersive activity of d-amino acids (d-AAs) on biofilms from clinical wound isolates of Staphylococcus aureus and Pseudomonas aeruginosa; moreover, we determined whether combinations of d-AAs and antibiotics (clindamycin, cefazolin, oxacillin, rifampin, and vancomycin for S. aureus and amikacin, colistin, ciprofloxacin, imipenem, and ceftazidime for P. aeruginosa) enhance activity against biofilms. d-Met, d-Phe, and d-Trp at concentrations of ≥5 mM effectively dispersed preformed biofilms of S. aureus and P. aeruginosa clinical isolates, an effect that was enhanced when they were combined as an equimolar mixture (d-Met/d-Phe/d-Trp). When combined with d-AAs, the activity of rifampin was significantly enhanced against biofilms of clinical isolates of S. aureus, as indicated by a reduction in the minimum biofilm inhibitory concentration (MBIC) (from 32 to 8 μg/ml) and a >2-log reduction of viable biofilm bacteria compared to treatment with antibiotic alone. The addition of d-AAs was also observed to enhance the activity of colistin and ciprofloxacin against biofilms of P. aeruginosa, reducing the observed MBIC and the number of viable bacteria by >2 logs and 1 log at 64 and 32 μg/ml in contrast to antibiotics alone. These findings indicate that the biofilm dispersal activity of d-AAs may represent an effective strategy, in combination with antimicrobials, to release bacteria from biofilms, subsequently enhancing antimicrobial activity. PMID:24841260

  7. The Effects of Berberine and Palmatine on Efflux Pumps Inhibition with Different Gene Patterns in Pseudomonas aeruginosa Isolated from Burn Infections

    PubMed Central

    Aghayan, Seyed Sajjad; Kalalian Mogadam, Hamidreza; Fazli, Mozhgan; Darban-Sarokhalil, Davood; Khoramrooz, Seyed Sajjad; Jabalameli, Fereshteh; Yaslianifard, Somayeh; Mirzaii, Mehdi

    2017-01-01

    Background: Related Multidrug Resistance (MDR) to efflux pumps is a significant problem in treating infections caused by Pseudomonas aeruginosa (P. aeruginosa). Plant compounds have been identified as Pump Inhibitors (EPIs). In the current study, the potential effect of Berberine and Palmatine as EPIs were investigated on efflux pump inhibition through focusing on different gene patterns in P. aeruginosa isolated from burn infections. Methods: All isolates were collected and identified using the standard biochemical tests. Antimicrobial sensitivity was performed based on disk agar diffusion method for 12 antibiotics. MIC-MBC tests were also performed based on the broth microdilution method to detect synergistic relationship between ciprofloxacin, Berberine and Palmatine. Detection of mexA, mexB, mexC, mexD, mexE, mexF and mexX was conducted by PCR assay. Fisher’s Exact test and Logistic Regression were used as statistical tools. Results: A total of 60 P. aeruginosa isolates were collected. The highest and lowest levels of resistance were found to be respectively against clindamycin and tigecycline. Comparing the MIC with MBC distribution, it was found that Berberine and Palmatine lower the MIC-MBC level of ciprofloxacin. The PCR results indicated that the highest frequency is about MexAB-OprM operon. The statistical analysis among different gene patterns of efflux pumps showed that there were no significant relationships between the effectiveness of Berberine and Palmatine (p>0.05). Conclusion: It can be speculated that Berberine and Palmatine both act as EPIs and can be used as auxiliary treatments with the purpose of increasing the effect of available antibiotics as well as decreasing the emergence of MDR bacteria. The efficiency of these combinations should be studied further under in vivo conditions to have a more comprehensive conclusion regarding this issue. PMID:28090273

  8. Waste Isolation Pilot Plant Annual Site Environmental Report for 2012

    SciTech Connect

    2013-09-01

    The purpose of the Waste Isolation Pilot Plant (WIPP) Annual Site Environmental Report for 2012 (ASER) is to provide information required by U.S. Department of Energy (DOE) Order 231.1B, Environment, Safety, and Health Reporting. Specifically, the ASER presents summary environmental data to: Characterize site environmental management performance; Summarize environmental occurrences and responses reported during the calendar year; Confirm compliance with environmental standards and requirements; Highlight significant environmental accomplishments, including progress toward the DOE Environmental Sustainability Goals made through implementation of the WIPP Environmental Management System (EMS).

  9. Responses of enzymatic antioxidants and non-enzymatic antioxidants in the cyanobacterium Microcystis aeruginosa to the allelochemical ethyl 2-methyl acetoacetate (EMA) isolated from reed (Phragmites communis).

    PubMed

    Hong, Yu; Hu, Hong-Ying; Xie, Xing; Li, Feng-Min

    2008-08-25

    Macrophytic allelochemicals are considered an environment-friendly and promising alternative to control algal bloom. However, studies examining the potential mechanisms of inhibitory allelochemicals on algae are few. The allelochemical ethyl 2-methyl acetoacetate (EMA), isolated from reed (Phragmites communis), was a strong allelopathic inhibitor on the growth of Microcystis aeruginosa. EMA-induced antioxidant responses were investigated in the cyanobacterium M. aeruginosa to understand the mechanism of EMA inhibition on algal growth. The activities of enzymatic antioxidants superoxide dismutase (SOD) and catalase (CAT), and the contents of non-enzymatic antioxidants reduced glutathione (GSH) and ascorbic acid (AsA) of M. aeruginosa cells were analyzed after treatments with different concentrations of EMA. Exposure of M. aeruginosa to EMA caused changes in enzyme activities and contents of non-enzymatic antioxidants in different manners. The decrease in SOD activity occurred first after 4 h of EMA exposure, and more markedly after 40 h. CAT activity did not change after 4 h of EMA exposure, but increased obviously after 40 h. The contents of AsA and GSH were increased greatly by EMA after 4 h. After 60 h, low EMA concentrations still increased the CAT activity and the contents of AsA and GSH, but high EMA concentrations started to impose a marked suppression on them. EMA increased dehydroascorbate (DHAsA) and oxidized glutathione (GSSG) contents during all exposure times. After 60 h, the regeneration rates of AsA and GSH (represented by the AsA/DHAsA ratio and GSH/GSSG ratio, respectively) were reduced by high EMA concentrations. These results suggest that the activation of CAT and the availability of AsA and GSH at early exposure are important to counteract the oxidative stress induced by EMA, and the inactivation of SOD may be crucial to the growth inhibition of M. aeruginosa by EMA.

  10. ISPa46, a novel insertion sequence in the oprD porin gene of an imipenem-resistant Pseudomonas aeruginosa isolate from a cystic fibrosis patient in Marseille, France.

    PubMed

    Diene, Seydina M; L'homme, Tiphanie; Bellulo, Sophia; Stremler, Nathalie; Dubus, Jean-Christophe; Mely, Laurent; Leroy, Sylvie; Degand, Nicolas; Rolain, Jean-Marc

    2013-09-01

    Clinical isolates of Pseudomonas aeruginosa exhibiting high-level resistance to carbapenems were recovered from a French patient with cystic fibrosis (CF) who had not received carbapenem therapy. This study was conducted to investigate the molecular mechanism conferring the carbapenem-resistant phenotype in clinical isolates of P. aeruginosa recovered from the same CF patient chronically colonised since 2005. Investigation of imipenem resistance of P. aeruginosa strain_02 isolated in May 2011 showed no carbapenemase activity. However, amplification and sequencing of the oprD porin gene revealed disruption of this gene by an insertion sequence (IS) element of 1337 bp that contained a novel transposase of 1227 bp (ISPa46) bordered by two terminal imperfect inverted repeats of 28 bp, which was associated with carbapenem resistance. Retrospective analysis of five additional strains of P. aeruginosa isolated before May 2011 from the same patient revealed that all isolates were likely to be the same clone by multilocus sequence typing analysis (ST540/551), but one of the five isolates was imipenem-susceptible. Although it was possible to demonstrate the presence of ISPa46 in all strains by PCR, this IS was transposed in the oprD gene only for imipenem-resistant isolates. Therefore, this study reports a novel IS element (ISPa46) in P. aeruginosa clinical isolates of a CF patient in Marseille, France, that was associated with carbapenem resistance and was selected in the absence of carbapenem treatment.

  11. Identification of plasmid OXA and other β-lactamase genes among carbapenem-resistant isolates of Pseudomonas aeruginosa from the Clinical University Hospital in northeastern Poland.

    PubMed

    Sacha, Paweł; Michalska, Anna; Ojdana, Dominika; Wieczorek, Piotr; Hauschild, Tomasz; Majewski, Piotr; Tryniszewska, Elżbieta

    2015-04-01

    The aim of the study was to evaluate the prevalence of OXA and other β-lactamase genes, antibiotic susceptibility, and the genetic relatedness among clinical isolates of P. aeruginosa resistant to carbapenems. The presence of bla- OXA genes was demonstrated in 48% of isolates belonging to four PFGE profiles. Most of them contained the blaOXA-2 gene (88.3%). Other blaOXA genes (Ps1310 with blaOXA-30 and Ps1309 with blaOXA-10) were found in only two isolates. The tested isolates also contained other β-lactamase genes such as blaVIM-2, blaVIM-4, blaSHV-5, and blaTEM-1. All isolates were susceptible only to colistin (100%).

  12. Evaluation of Mannosidase and Trypsin Enzymes Effects on Biofilm Production of Pseudomonas aeruginosa Isolated from Burn Wound Infections

    PubMed Central

    Banar, Maryam; Emaneini, Mohammad; Satarzadeh, Mhboubeh; Abdellahi, Nafiseh; Beigverdi, Reza; van Leeuwen, Willem B.; Jabalameli, Fereshteh

    2016-01-01

    Biofilm is an important virulence factor in Pseudomonas aeruginosa and has a substantial role in antibiotic resistance and chronic burn wound infections. New therapeutic agents against P. aeruginosa, degrading biofilms in burn wounds and improving the efficacy of current antimicrobial agents, are required. In this study, the effects of α-mannosidase, β-mannosidase and trypsin enzymes on the degradation of P. aeruginosa biofilms and on the reduction of ceftazidime minimum biofilm eliminating concentrations (MBEC) were evaluated. All tested enzymes, destroyed the biofilms and reduced the ceftazidime MBECs. However, only trypsin had no cytotoxic effect on A-431 human epidermoid carcinoma cell lines. In conclusion, since trypsin had better features than mannosidase enzymes, it can be a promising agent in combatting P. aeruginosa burn wound infections. PMID:27736961

  13. Antimicrobial Activity of Fosfomycin-Tobramycin Combination against Pseudomonas aeruginosa Isolates Assessed by Time-Kill Assays and Mutant Prevention Concentrations.

    PubMed

    Díez-Aguilar, María; Morosini, María Isabel; Tedim, Ana P; Rodríguez, Irene; Aktaş, Zerrin; Cantón, Rafael

    2015-10-01

    The antibacterial activity of fosfomycin-tobramycin combination was studied by time-kill assay in eight Pseudomonas aeruginosa clinical isolates belonging to the fosfomycin wild-type population (MIC = 64 μg/ml) but with different tobramycin susceptibilities (MIC range, 1 to 64 μg/ml). The mutant prevention concentration (MPC) and mutant selection window (MSW) were determined in five of these strains (tobramycin MIC range, 1 to 64 μg/ml) in aerobic and anaerobic conditions simulating environments that are present in biofilm-mediated infections. Fosfomycin-tobramycin was synergistic and bactericidal for the isolates with mutations in the mexZ repressor gene, with a tobramycin MIC of 4 μg/ml. This effect was not observed in strains displaying tobramycin MICs of 1 to 2 μg/ml due to the strong bactericidal effect of tobramycin alone. Fosfomycin presented higher MPC values (range, 2,048 to >2,048 μg/ml) in aerobic and anaerobic conditions than did tobramycin (range, 16 to 256 μg/ml). Interestingly, the association rendered narrow or even null MSWs in the two conditions. However, for isolates with high-level tobramycin resistance that harbored aminoglycoside nucleotidyltransferases, time-kill assays showed no synergy, with wide MSWs in the two environments. glpT gene mutations responsible for fosfomycin resistance in P. aeruginosa were determined in fosfomycin-susceptible wild-type strains and mutant derivatives recovered from MPC studies. All mutant derivatives had changes in the GlpT amino acid sequence, which resulted in a truncated permease responsible for fosfomycin resistance. These results suggest that fosfomycin-tobramycin can be an alternative for infections due to P. aeruginosa since it has demonstrated synergistic and bactericidal activity in susceptible isolates and those with low-level tobramycin resistance. It also prevents the emergence of resistant mutants in either aerobic or anaerobic environments.

  14. Antimicrobial Activity of Fosfomycin-Tobramycin Combination against Pseudomonas aeruginosa Isolates Assessed by Time-Kill Assays and Mutant Prevention Concentrations

    PubMed Central

    Díez-Aguilar, María; Tedim, Ana P.; Rodríguez, Irene; Aktaş, Zerrin; Cantón, Rafael

    2015-01-01

    The antibacterial activity of fosfomycin-tobramycin combination was studied by time-kill assay in eight Pseudomonas aeruginosa clinical isolates belonging to the fosfomycin wild-type population (MIC = 64 μg/ml) but with different tobramycin susceptibilities (MIC range, 1 to 64 μg/ml). The mutant prevention concentration (MPC) and mutant selection window (MSW) were determined in five of these strains (tobramycin MIC range, 1 to 64 μg/ml) in aerobic and anaerobic conditions simulating environments that are present in biofilm-mediated infections. Fosfomycin-tobramycin was synergistic and bactericidal for the isolates with mutations in the mexZ repressor gene, with a tobramycin MIC of 4 μg/ml. This effect was not observed in strains displaying tobramycin MICs of 1 to 2 μg/ml due to the strong bactericidal effect of tobramycin alone. Fosfomycin presented higher MPC values (range, 2,048 to >2,048 μg/ml) in aerobic and anaerobic conditions than did tobramycin (range, 16 to 256 μg/ml). Interestingly, the association rendered narrow or even null MSWs in the two conditions. However, for isolates with high-level tobramycin resistance that harbored aminoglycoside nucleotidyltransferases, time-kill assays showed no synergy, with wide MSWs in the two environments. glpT gene mutations responsible for fosfomycin resistance in P. aeruginosa were determined in fosfomycin-susceptible wild-type strains and mutant derivatives recovered from MPC studies. All mutant derivatives had changes in the GlpT amino acid sequence, which resulted in a truncated permease responsible for fosfomycin resistance. These results suggest that fosfomycin-tobramycin can be an alternative for infections due to P. aeruginosa since it has demonstrated synergistic and bactericidal activity in susceptible isolates and those with low-level tobramycin resistance. It also prevents the emergence of resistant mutants in either aerobic or anaerobic environments. PMID:26195514

  15. Correlation between cytotoxicity induced by Pseudomonas aeruginosa clinical isolates from acute infections and IL-1β secretion in a model of human THP-1 monocytes.

    PubMed

    Anantharajah, Ahalieyah; Buyck, Julien M; Faure, Emmanuel; Glupczynski, Youri; Rodriguez-Villalobos, Hector; De Vos, Daniel; Pirnay, Jean-Paul; Bilocq, Florence; Guery, Benoît; Tulkens, Paul M; Mingeot-Leclercq, Marie-Paule; Van Bambeke, Françoise

    2015-10-01

    Type III secretion system (T3SS) in Pseudomonas aeruginosa is associated with poor clinical outcome in acute infections. T3SS allows for injection of bacterial exotoxins (e.g. ExoU or ExoS) into the host cell, causing cytotoxicity. It also activates the cytosolic NLRC4 inflammasome, activating caspase-1, inducing cytotoxicity and release of mature IL-1β, which impairs bacterial clearance. In addition, flagellum-mediated motility has been suggested to also modulate inflammasome response and IL-1β release. Yet the capacity of clinical isolates to induce IL-1β release and its relation with cytotoxicity have never been investigated. Using 20 clinical isolates from acute infections with variable T3SS expression levels and human monocytes, our aim was to correlate IL-1β release with toxin expression, flagellar motility and cytotoxicity. ExoU-producing isolates caused massive cell death but minimal release of IL-1β, while those expressing T3SS but not ExoU (i.e. expressing ExoS or no toxins) induced caspase-1 activation and IL-1β release, the level of which was correlated with cytotoxicity. Both effects were prevented by a specific caspase-1 inhibitor. Flagellar motility was not correlated with cytotoxicity or IL-1β release. No apoptosis was detected. Thus, T3SS cytotoxicity is accompanied by a modification in cytokine balance for P. aeruginosa clinical isolates that do not express ExoU.

  16. Seeking the source of Pseudomonas aeruginosa infections in a recently opened hospital: an observational study using whole-genome sequencing

    PubMed Central

    Quick, Joshua; Cumley, Nicola; Wearn, Christopher M; Niebel, Marc; Constantinidou, Chrystala; Thomas, Chris M; Pallen, Mark J; Moiemen, Naiem S; Bamford, Amy; Oppenheim, Beryl; Loman, Nicholas J

    2014-01-01

    Objectives Pseudomonas aeruginosa is a common nosocomial pathogen responsible for significant morbidity and mortality internationally. Patients may become colonised or infected with P. aeruginosa after exposure to contaminated sources within the hospital environment. The aim of this study was to determine whether whole-genome sequencing (WGS) can be used to determine the source in a cohort of burns patients at high risk of P. aeruginosa acquisition. Study design An observational prospective cohort study. Setting Burns care ward and critical care ward in the UK. Participants Patients with >7% total burns by surface area were recruited into the study. Methods All patients were screened for P. aeruginosa on admission and samples taken from their immediate environment, including water. Screening patients who subsequently developed a positive P. aeruginosa microbiology result were subject to enhanced environmental surveillance. All isolates of P. aeruginosa were genome sequenced. Sequence analysis looked at similarity and relatedness between isolates. Results WGS for 141 P. aeruginosa isolates were obtained from patients, hospital water and the ward environment. Phylogenetic analysis revealed eight distinct clades, with a single clade representing the majority of environmental isolates in the burns unit. Isolates from three patients had identical genotypes compared with water isolates from the same room. There was clear clustering of water isolates by room and outlet, allowing the source of acquisitions to be unambiguously identified. Whole-genome shotgun sequencing of biofilm DNA extracted from a thermostatic mixer valve revealed this was the source of a P. aeruginosa subpopulation previously detected in water. In the remaining two cases there was no clear link to the hospital environment. Conclusions This study reveals that WGS can be used for source tracking of P. aeruginosa in a hospital setting, and that acquisitions can be traced to a specific source within a

  17. Waste Isolation Pilot Plant 1999 Site Environmental Report

    SciTech Connect

    Evans, Roy B.; Adams, Amy; Martin, Don; Morris, Randall C.; Reynolds, Timothy D.; Warren, Ronald W.

    2000-09-30

    The U.S. Department of Energy's (DOE)Carlsbad Area Office and the Westinghouse Waste Isolation Division (WID) are dedicated to maintaining high quality management of Waste Isolation Pilot Plant (WIPP) environmental resources. DOE Order 5400.1, General Environmental Protection Program, and DOE Order 231.1, Environmental, Safety, and Health Reporting, require that the environment at and near DOE facilities be monitored to ensure the safety and health of the public and the environment. This Waste Isolation Pilot Plant 1999 Site Environmental Report summarizes environmental data from calendar year 1999 that characterize environmental management performance and demonstrate compliance with federal and state regulations. This report was prepared in accordance with DOE Order 5400.1, DOE Order 231.1, the Environmental Regulatory Guide for Radiological Effluent Monitoring and Environmental Surveillance (DOE/EH- 0173T), and the Waste Isolation Pilot Plant Environmental Protection Implementation Plan (DOE/WIPP 96-2199). The above orders and guidance documents require that DOE facilities submit an Annual Site Environmental Report to DOE Headquarters, Office of the Assistant Secretary for Environment, Safety, and Health. The purpose of this report is to provide a comprehensive description of operational environmental monitoring activities, to provide an abstract of environmental activities conducted to characterize site environmental management performance to confirm compliance with environmental standards and requirements, and to highlight significant programs and efforts of environmental merit at WIPP during calendar year 1999. WIPP received its first shipment of waste on March 26, 1999. In 1999, no evidence was found of any adverse effects from WIPP on the surrounding environment. Radionuclide concentrations in the environment surrounding WIPP were not statistically higher in 1999 than in 1998.

  18. Novel Combinations of Synthesized ZnO NPs and Ceftazidime: Evaluation of their Activity against Standards and New Clinically Isolated Pseudomonas aeruginosa

    PubMed Central

    Isaei, Elham; Mansouri, Shahla; Mohammadi, Fereshteh; Taheritarigh, Sadegh; Mohammadi, Zohreh

    2016-01-01

    Background: Antibiotic resistant bacteria can be considered as a main problem in infection management. Zinc oxide nanoparticles (ZnO NPs), individually or in combination with antibiotics, can be considered as good candidates for struggling against drug resistant bacteria. Methods: In this study, Zinc oxide nanoparticles were synthesized using sol-gel method in low temperature as a cost effective procedure and characterized by X-ray diffraction and Scanning Electron Microscopy. Antibacterial activity of 9 new combinations of Zinc oxide nanoparticles and ceftazidime was assessed against standards and new clinically isolated multi drug resistant Pseudomonas aeruginosa (P. aeruginosa), in order to evaluate enhancement effect of synthesized Zinc oxide nanoparticles on antibacterial activity of ceftazidime. Results: The results indicated that desirable effects can be seen at 6 and 7 mM of Zinc oxide nanoparticles (60 to 100% inhibition). Moreover, after evaluation of 9 new combinations with various concentrations of both components, it was demonstrated that Zinc oxide nanoparticles can enhance the antibacterial activity of ceftazidime, against some bacterial strains of P. aeruginosa. The highest activity was observed with the concentration of 20 μg/ml ceftazidime in the presence of 5, 6 or 7 mM of Zinc oxide nanoparticles. Conclusion: Zinc oxide nanoparticles in appropriate concentrations can be proposed as new and promising candidates for overcoming bacterial resistance. PMID:27920884

  19. CpxR Activates MexAB-OprM Efflux Pump Expression and Enhances Antibiotic Resistance in Both Laboratory and Clinical nalB-Type Isolates of Pseudomonas aeruginosa

    PubMed Central

    Yi, Xue-Xian; O’Gara, Fergal; Wang, Yi-Ping

    2016-01-01

    Resistance-Nodulation-Division (RND) efflux pumps are responsible for multidrug resistance in Pseudomonas aeruginosa. In this study, we demonstrate that CpxR, previously identified as a regulator of the cell envelope stress response in Escherichia coli, is directly involved in activation of expression of RND efflux pump MexAB-OprM in P. aeruginosa. A conserved CpxR binding site was identified upstream of the mexA promoter in all genome-sequenced P. aeruginosa strains. CpxR is required to enhance mexAB-oprM expression and drug resistance, in the absence of repressor MexR, in P. aeruginosa strains PA14. As defective mexR is a genetic trait associated with the clinical emergence of nalB-type multidrug resistance in P. aeruginosa during antibiotic treatment, we investigated the involvement of CpxR in regulating multidrug resistance among resistant isolates generated in the laboratory via antibiotic treatment and collected in clinical settings. CpxR is required to activate expression of mexAB-oprM and enhances drug resistance, in the absence or presence of MexR, in ofloxacin-cefsulodin-resistant isolates generated in the laboratory. Furthermore, CpxR was also important in the mexR-defective clinical isolates. The newly identified regulatory linkage between CpxR and the MexAB-OprM efflux pump highlights the presence of a complex regulatory network modulating multidrug resistance in P. aeruginosa. PMID:27736975

  20. Effects of mucoid and non-mucoid Pseudomonas aeruginosa isolates from cystic fibrosis patients on inflammatory mediator release from human polymorphonuclear granulocytes and rat mast cells.

    PubMed Central

    Friedl, P; König, B; König, W

    1992-01-01

    Mucoid Pseudomonas aeruginosa causing chronic bronchopulmonary infection in cystic fibrosis (CF) patients may interfere with host defence mechanisms. We investigated 13 P. aeruginosa strains isolated from sputa of CF patients with regard to the induction or modulation of inflammatory mediator release from human neutrophils (PMN) and rat mast cells. The effects of mucoid as compared to non-mucoid bacteria were studied using a mucoid strain and its non-mucoid revertant. The release of leukotrienes (LT) and histamine in response to the majority of the CF strains was insignificant. However, preincubation of PMN with P. aeruginosa caused a dose-dependent decrease (50-95%) of LTB4 and LTC4 generation and LTB4 metabolism induced by the Ca(2+)-ionophore A23187 or opsonized zymosan (ZX) (P less than 0.001). The mucoid strains caused a three- to 10-fold higher impairment of LTB4 release (P less than 0.05) and a concomitant down-regulation of LTB4 receptors on neutrophils. Inhibitory effects were also obtained for mucoid and non-mucoid bacteria when the phorbol-ester or the Ca(2+)-ionophore induced luminol enhanced chemiluminescence response (P less than 0.001) or the histamine release from rat peritoneal mast cells (P less than 0.01) was studied. The bacteria-cell contact with non-mucoid strains was associated with an increased Ca2+ influx into PMN, whereas mucoid bacteria had no effect. In addition, a protein kinase C-dependent decrease of the C3bi receptor was suppressed by the mucoid--and less effectively--by the non-mucoid strain. The results suggest that the impairment of the phagocytic and inflammatory system may contribute to the pathogenesis and persistence of mucoid P. aeruginosa infection in CF. PMID:1321094

  1. Waste Isolation Pilot Plant CY 2000 Site Environmental Report

    SciTech Connect

    Westinghouse TRU Solutions, LLC; Environmental Science and Research Foundation, Inc.

    2001-12-31

    The U.S. Department of Energy's (DOE) Carlsbad Field Office and Westinghouse TRU Solutions, LLC (WTS) are dedicated to maintaining high quality management of Waste Isolation Pilot Plant (WIPP) environmental resources. DOE Order 5400.1, General Environmental Protection Program, and DOE Order 231.1, Environmental, Safety, and Health Reporting, require that the environment at and near DOE facilities be monitored to ensure the safety and health of the public and the environment. This Waste Isolation Pilot Plant 2000 Site Environmental Report summarizes environmental data from calendar year (CY) 2000 that characterize environmental management performance and demonstrate compliance with federal and state regulations. This report was prepared in accordance with DOE Order 5400.1, DOE Order 231.1, the Environmental Regulatory Guide for Radiological Effluent Monitoring and Environmental Surveillance (DOE/EH-0173T), and the Waste Isolation Pilot Plant Environmental Protect ion Implementation Plan (DOE/WIPP 96-2199). The above orders and guidance documents require that DOE facilities submit an Annual Site Environmental Report to DOE Headquarters, Office of the Assistant Secretary for Environment, Safety, and Health. The purpose of this report is to provide a comprehensive description of operational environmental monitoring activities, to provide an abstract of environmental activities conducted to characterize site environmental management performance to confirm compliance with environmental standards and requirements, and to highlight significant programs and efforts of environmental merit at WIPP during CY 2000. The format of this report follows guidance offered in a June 1, 2001 memo from DOE's Office of Policy and Guidance with the subject ''Guidance for the preparation of Department of Energy (DOE) Annual Site Environmental Reports (ASERs) for Calendar Year 2000.'' WIPP received its first shipment of waste on March 26, 1999. In 2000, no evidence was found of any adverse

  2. Overexpression of AmpC and Efflux Pumps in Pseudomonas aeruginosa Isolates from Bloodstream Infections: Prevalence and Impact on Resistance in a Spanish Multicenter Study▿

    PubMed Central

    Cabot, Gabriel; Ocampo-Sosa, Alain A.; Tubau, Fe; Macia, María D.; Rodríguez, Cristina; Moya, Bartolomé; Zamorano, Laura; Suárez, Cristina; Peña, Carmen; Martínez-Martínez, Luis; Oliver, Antonio

    2011-01-01

    The prevalence and impact of the overexpression of AmpC and efflux pumps were evaluated with a collection of 190 Pseudomonas aeruginosa isolates recovered from bloodstream infections in a 2008 multicenter study (10 hospitals) in Spain. The MICs of a panel of 13 antipseudomonal agents were determined by microdilution, and the expressions of ampC, mexB, mexY, mexD, and mexF were determined by real-time reverse transcription (RT)-PCR. Up to 39% of the isolates overexpressed at least one of the mechanisms. ampC overexpression (24.2%) was the most prevalent mechanism, followed by mexY (13.2%), mexB (12.6%), mexF (4.2%), and mexD (2.2%). The overexpression of mexB plus mexY, documented for 5.3% of the isolates, was the only combination showing a significantly (P = 0.02) higher prevalence than expected from the frequencies of the individual mechanisms (1.6%). Additionally, all imipenem-resistant isolates studied (25 representative isolates) showed inactivating mutations in oprD. Most of the isolates nonsusceptible to piperacillin-tazobactam (96%) and ceftazidime (84%) overexpressed ampC, while mexB (25%) and mexY (29%) overexpressions gained relevance among cefepime-nonsusceptible isolates. Nevertheless, the prevalence of mexY overexpression was highest among tobramycin-nonsusceptible isolates (37%), and that of mexB was highest among meropenem-nonsusceptible isolates (33%). Regarding ciprofloxacin-resistant isolates, besides the expected increased prevalence of efflux pump overexpression, a highly significant link to ampC overexpression was documented for the first time: up to 52% of ciprofloxacin-nonsusceptible isolates overexpressed ampC, sharply contrasting with the 24% documented for the complete collection (P < 0.001). In summary, mutation-driven resistance was frequent in P. aeruginosa isolates from bloodstream infections, whereas metallo-β-lactamases, detected in 2 isolates (1%) producing VIM-2, although with increasing prevalences, were still uncommon. PMID

  3. Emergence of a mutL mutation causing multilocus sequence typing-pulsed-field gel electrophoresis discrepancy among Pseudomonas aeruginosa isolates from a cystic fibrosis patient.

    PubMed

    García-Castillo, María; Máiz, Luis; Morosini, María-Isabel; Rodríguez-Baños, Mercedes; Suarez, Lucrecia; Fernández-Olmos, Ana; Baquero, Fernando; Cantón, Rafael; del Campo, Rosa

    2012-05-01

    A multilocus sequence type (MLST) shift (from ST242 to ST996) was detected in Pseudomonas aeruginosa isolates with a uniform pulsed-field gel electrophoresis (PFGE) pattern obtained from a chronically colonized patient. MLST mutational change involved the mutL gene with the consequent emergence of a hypermutable phenotype. This observation challenges the required neutrality of mutL as an appropriate marker in MLST and alerts researchers to the limitations of MLST-only-based population studies in chronic infections under constant antibiotic selective pressure.

  4. Emergence of a mutL Mutation Causing Multilocus Sequence Typing–Pulsed-Field Gel Electrophoresis Discrepancy among Pseudomonas aeruginosa Isolates from a Cystic Fibrosis Patient

    PubMed Central

    García-Castillo, María; Máiz, Luis; Morosini, María-Isabel; Rodríguez-Baños, Mercedes; Suarez, Lucrecia; Fernández-Olmos, Ana; Baquero, Fernando; Cantón, Rafael

    2012-01-01

    A multilocus sequence type (MLST) shift (from ST242 to ST996) was detected in Pseudomonas aeruginosa isolates with a uniform pulsed-field gel electrophoresis (PFGE) pattern obtained from a chronically colonized patient. MLST mutational change involved the mutL gene with the consequent emergence of a hypermutable phenotype. This observation challenges the required neutrality of mutL as an appropriate marker in MLST and alerts researchers to the limitations of MLST-only-based population studies in chronic infections under constant antibiotic selective pressure. PMID:22322352

  5. Nosocomial Spread of Colistin-Only-Sensitive Sequence Type 235 Pseudomonas aeruginosa Isolates Producing the Extended-Spectrum β-Lactamases GES-1 and GES-5 in Spain▿

    PubMed Central

    Viedma, Esther; Juan, Carlos; Acosta, Joshi; Zamorano, Laura; Otero, Joaquín R.; Sanz, Francisca; Chaves, Fernando; Oliver, Antonio

    2009-01-01

    The mechanisms responsible for the increasing prevalence of colistin-only-sensitive (COS) Pseudomonas aeruginosa isolates in a Spanish hospital were investigated. Pulsed-field gel electrophoresis revealed that 24 (50%) of the studied isolates belonged to the same clone, identified as the internationally spread sequence type 235 (ST235) through multilocus sequence typing. In addition to several mutational resistance mechanisms, an integron containing seven resistance determinants was detected. Remarkably, the extended-spectrum β-lactamase GES-1 and its Gly170Ser carbapenem-hydrolyzing derivative GES-5 were first documented to be encoded in a single integron. This work is the first to describe GES enzymes in Spain and adds them to the growing list of β-lactamases of concern (PER, VIM, and OXA) detected in ST235 clone isolates. PMID:19738007

  6. Mechanisms of carbapenem resistance in endemic Pseudomonas aeruginosa isolates after an SPM-1 metallo-β-lactamase producing strain subsided in an intensive care unit of a teaching hospital in Brazil

    PubMed Central

    Cacci, Luciana Camila; Chuster, Stephanie Gomes; Martins, Natacha; do Carmo, Pâmella Rodrigues; Girão, Valéria Brígido de Carvalho; Nouér, Simone Aranha; de Freitas, Wania Vasconcelos; de Matos, Juliana Arruda; Magalhães, Ana Cristina de Gouveia; Ferreira, Adriana Lúcia Pires; Picão, Renata Cristina; Moreira, Beatriz Meurer

    2016-01-01

    Carbapenem-resistance mechanisms are a challenge in the treatment of Pseudomonas aeruginosa infections. We investigated changes in P. aeruginosa carbapenem-resistance determinants over a time period of eight years after the emergence of São Paulo metallo-β-lactamase in a university hospital in Rio de Janeiro, Brazil. Patients admitted to the intensive care unit (ICU) were screened for P. aeruginosa colonisation and followed for the occurrence of infections from April 2007 to April 2008. The ICU environment was also sampled. Isolates were typed using random amplified polymorphic DNA, pulsed-field gel electrophoresis and multilocus sequence typing. Antimicrobial susceptibility was determined by disk diffusion and E-test, production of carbapenemases by a modified-CarbaNP test and presence of carbapenemase-encoding genes by polymerase chain reaction. Non-carbapenemase resistance mechanisms studied included efflux and AmpC overexpression by PAβN and cloxacillin susceptibility enhancement, respectively, as well as oprD mutations. From 472 P. aeruginosa clinical isolates (93 patients) and 17 isolates from the ICU environment, high genotypic diversity and several international clones were observed; one environment isolate belonged to the blaSPM-1 P. aeruginosa epidemic genotype. Among isolates from infections, 10 (29%) were carbapenem resistant: none produced carbapenemases, three exhibited all non-carbapenemase mechanisms studied, six presented a combination of two mechanisms, and one exclusively displayed oprD mutations. Carbapenem-resistant P. aeruginosa displayed a polyclonal profile after the SPM-1 epidemic genotype declined. This phenomenon is connected with blaSPM-1 P. aeruginosa replaced by other carbapenem-resistant pathogens. PMID:27653359

  7. Mechanisms of carbapenem resistance in endemic Pseudomonas aeruginosa isolates after an SPM-1 metallo-β-lactamase producing strain subsided in an intensive care unit of a teaching hospital in Brazil.

    PubMed

    Cacci, Luciana Camila; Chuster, Stephanie Gomes; Martins, Natacha; Carmo, Pâmella Rodrigues do; Girão, Valéria Brígido de Carvalho; Nouér, Simone Aranha; Freitas, Wania Vasconcelos de; Matos, Juliana Arruda de; Magalhães, Ana Cristina de Gouveia; Ferreira, Adriana Lúcia Pires; Picão, Renata Cristina; Moreira, Beatriz Meurer

    2016-09-01

    Carbapenem-resistance mechanisms are a challenge in the treatment of Pseudomonas aeruginosa infections. We investigated changes in P. aeruginosa carbapenem-resistance determinants over a time period of eight years after the emergence of São Paulo metallo-β-lactamase in a university hospital in Rio de Janeiro, Brazil. Patients admitted to the intensive care unit (ICU) were screened for P. aeruginosa colonisation and followed for the occurrence of infections from April 2007 to April 2008. The ICU environment was also sampled. Isolates were typed using random amplified polymorphic DNA, pulsed-field gel electrophoresis and multilocus sequence typing. Antimicrobial susceptibility was determined by disk diffusion and E-test, production of carbapenemases by a modified-CarbaNP test and presence of carbapenemase-encoding genes by polymerase chain reaction. Non-carbapenemase resistance mechanisms studied included efflux and AmpC overexpression by PAβN and cloxacillin susceptibility enhancement, respectively, as well as oprD mutations. From 472 P. aeruginosa clinical isolates (93 patients) and 17 isolates from the ICU environment, high genotypic diversity and several international clones were observed; one environment isolate belonged to the blaSPM-1 P. aeruginosa epidemic genotype. Among isolates from infections, 10 (29%) were carbapenem resistant: none produced carbapenemases, three exhibited all non-carbapenemase mechanisms studied, six presented a combination of two mechanisms, and one exclusively displayed oprD mutations. Carbapenem-resistant P. aeruginosa displayed a polyclonal profile after the SPM-1 epidemic genotype declined. This phenomenon is connected with blaSPM-1 P. aeruginosa replaced by other carbapenem-resistant pathogens.

  8. Waste Isolation Pilot Plant 2001 Site Environmental Report

    SciTech Connect

    Westinghouse TRU Solutions, Inc.

    2002-09-20

    The United States (U.S.) Department of Energy's (DOE) Carlsbad Field Office (CBFO) and Westinghouse TRU Solutions LLC (WTS) are dedicated to maintaining high quality management of Waste Isolation Pilot Plant (WIPP) environmental resources. DOE Order 5400.1, General Environmental Protection Program, and DOE Order 231.1, Environmental, Safety, and Health Reporting, require that the environment at and near DOE facilities be monitored to ensure the safety and health of the public and the environment. This Waste Isolation Pilot Plant 2001 Site Environmental Report summarizes environmental data from calendar year (CY) 2001 that characterize environmental management performance and demonstrate compliance with federal and state regulations. This report was prepared in accordance with DOE Order 5400.1, DOE Order 231.1, the Environmental Regulatory Guide for Radiological Effluent Monitoring and Environmental Surveillance (DOE/EH- 0173T), and the Waste Isolation Pilot Plant Environmental Protection Implementation Plan (DOE/WIPP 96-2199). The above Orders and guidance documents require that DOE facilities submit an annual site environmental report to DOE Headquarters, Office of the Assistant Secretary for Environment, Safety, and Health; and the New Mexico Environment Department (NMED). The purpose of this report is to provide a comprehensive description of operational environmental monitoring activities, to provide an abstract of environmental activities conducted to characterize site environmental management performance to confirm compliance with environmental standards and requirements, and to highlight significant programs and efforts of environmental merit at WIPP during CY 2001. WIPP received its first shipment of waste on March 26, 1999. In 2001, no evidence was found of any adverse effects from WIPP on the surrounding environment.

  9. Complete Genome Sequence of the Triclosan- and Multidrug-Resistant Pseudomonas aeruginosa Strain B10W Isolated from Municipal Wastewater

    PubMed Central

    Zhong, Chuanqing; Nelson, Matthew; Cao, Guangxiang

    2017-01-01

    ABSTRACT Here, we report the complete genome sequence of the triclosan- and multidrug-resistant Pseudomonas aeruginosa strain B10W, obtained from municipal wastewater in Hawaii. The bacterium has a 6.7-Mb genome, contains 6,391 coding sequences and 78 RNAs, with an average G+C content of 66.2 mol%. PMID:28104659

  10. Alterations of OprD in Carbapenem-Intermediate and -Susceptible Strains of Pseudomonas aeruginosa Isolated from Patients with Bacteremia in a Spanish Multicenter Study

    PubMed Central

    Cabot, Gabriel; Rodríguez, Cristina; Roman, Elena; Tubau, Fe; Macia, María D.; Moya, Bartolomé; Zamorano, Laura; Suárez, Cristina; Peña, Carmen; Domínguez, María A.; Moncalián, Gabriel; Oliver, Antonio; Martínez-Martínez, Luis

    2012-01-01

    We investigated the presence of OprD mutations in 60 strains of metallo-ß-lactamase-negative Pseudomonas aeruginosa intermediately susceptible (IS [n = 12]; MIC = 8 μg/ml) or susceptible (S [n = 48]; MICs ≤ 1 to 4 μg/ml) to imipenem and/or meropenem that were isolated from patients with bacteremia in order to evaluate their impact on carbapenem susceptibility profiles. The presence of mutations in oprD was detected by sequencing analysis. OprD expression was assessed by both outer membrane protein (OMP) analysis and real-time PCR (RT-PCR). Fourteen (23%) isolates had an OprD identical to that of PAO1, and OprD modifications were detected in 46 isolates (77%). Isolates were classified as OprD “full-length types” (T1 [n = 40, including both wild-type OprD and variants showing several polymorphisms]) and OprD “deficient types” (T2 [n = 3 for OprD frameshift mutations] and T3 [n = 17 for premature stop codons in oprD]). RT-PCR showed that 5 OprD type T1 isolates presented reduced transcription of oprD (0.1- to 0.4-fold compared to PAO1), while oprD levels increased more than 2-fold over that seen with PAO1 in 4 OprD type T1 isolates. A total of 50% of the isolates belonging to OprD “deficient types” were susceptible to both carbapenems, and 40% were susceptible to meropenem and intermediately susceptible to imipenem. Only one isolate (5%) within this group was intermediately susceptible to both carbapenems, and one (5%) was susceptible to imipenem and intermediately susceptible to meropenem. We concluded that OprD inactivating mutations in clinical isolates of P. aeruginosa are not restricted only to carbapenem-resistant isolates but are also found in isolates with imipenem or meropenem MICs of only 0.06 to 4 μg/ml. PMID:22290967

  11. Fingerprint Analysis and Identification of Strains ST309 as a Potential High Risk Clone in a Pseudomonas aeruginosa Population Isolated from Children with Bacteremia in Mexico City

    PubMed Central

    Morales-Espinosa, Rosario; Delgado, Gabriela; Espinosa, Luis F.; Isselo, Dassaev; Méndez, José L.; Rodriguez, Cristina; Miranda, Guadalupe; Cravioto, Alejandro

    2017-01-01

    Pseudomonas aeruginosa is an opportunistic pathogen and is associated with nosocomial infections. Its ability to thrive in a broad range of environments is due to a large and diverse genome of which its accessory genome is part. The objective of this study was to characterize P. aeruginosa strains isolated from children who developed bacteremia, using pulse-field gel electrophoresis, and in terms of its genomic islands, virulence genes, multilocus sequence type, and antimicrobial susceptibility. Our results showed that P. aeruginosa strains presented the seven virulence genes: toxA, lasB, lecA, algR, plcH, phzA1, and toxR, a type IV pilin alleles (TFP) group I or II. Additionally, we detected a novel pilin and accessory gene, expanding the number of TFP alleles to group VI. All strains presented the PAPI-2 Island and the majority were exoU+ and exoS+ genotype. Ten percent of the strains were multi-drug resistant phenotype, 18% extensively drug-resistant, 68% moderately resistant and only 3% were susceptible to all the antimicrobial tested. The most prevalent acquired β-Lactamase was KPC. We identified a group of ST309 strains, as a potential high risk clone. Our finding also showed that the strains isolated from patients with bacteremia have important virulence factors involved in colonization and dissemination as: a TFP group I or II; the presence of the exoU gene within the PAPI-2 island and the presence of the exoS gene. PMID:28298909

  12. Fingerprint Analysis and Identification of Strains ST309 as a Potential High Risk Clone in a Pseudomonas aeruginosa Population Isolated from Children with Bacteremia in Mexico City.

    PubMed

    Morales-Espinosa, Rosario; Delgado, Gabriela; Espinosa, Luis F; Isselo, Dassaev; Méndez, José L; Rodriguez, Cristina; Miranda, Guadalupe; Cravioto, Alejandro

    2017-01-01

    Pseudomonas aeruginosa is an opportunistic pathogen and is associated with nosocomial infections. Its ability to thrive in a broad range of environments is due to a large and diverse genome of which its accessory genome is part. The objective of this study was to characterize P. aeruginosa strains isolated from children who developed bacteremia, using pulse-field gel electrophoresis, and in terms of its genomic islands, virulence genes, multilocus sequence type, and antimicrobial susceptibility. Our results showed that P. aeruginosa strains presented the seven virulence genes: toxA, lasB, lecA, algR, plcH, phzA1, and toxR, a type IV pilin alleles (TFP) group I or II. Additionally, we detected a novel pilin and accessory gene, expanding the number of TFP alleles to group VI. All strains presented the PAPI-2 Island and the majority were exoU+ and exoS+ genotype. Ten percent of the strains were multi-drug resistant phenotype, 18% extensively drug-resistant, 68% moderately resistant and only 3% were susceptible to all the antimicrobial tested. The most prevalent acquired β-Lactamase was KPC. We identified a group of ST309 strains, as a potential high risk clone. Our finding also showed that the strains isolated from patients with bacteremia have important virulence factors involved in colonization and dissemination as: a TFP group I or II; the presence of the exoU gene within the PAPI-2 island and the presence of the exoS gene.

  13. Effect of biosurfactant and fertilizer on biodegradation of crude oil by marine isolates of Bacillus megaterium, Corynebacterium kutscheri and Pseudomonas aeruginosa.

    PubMed

    Thavasi, Rengathavasi; Jayalakshmi, Singaram; Banat, Ibrahim M

    2011-01-01

    This study was conducted to investigate the effects of fertilizers and biosurfactants on biodegradation of crude oil by three marine bacterial isolates; Bacillus megaterium, Corynebacterium kutscheri and Pseudomonas aeruginosa. Five sets of experiments were carried out in shake flask and microcosm conditions with crude oil as follows: Set 1-only bacterial cells added (no fertilizer and biosurfactant), Set 2-with additional fertilizer only, Set 3-with additional biosurfactant only, Set 4-with added biosurfactant+fertilizer, Set 5-with no bacterial cells added (control), all the above experimental sets were incubated for 168 h. The biosurfactant+fertilizer added Set 4, resulted in maximum crude oil degradation within shake flask and microcosm conditions. Among the three bacterial isolates, P. aeruginosa and biosurfactant produced by this strain resulted in maximum crude oil degradation compared to the other two bacterial strains investigated. Interestingly, when biosurfactant and bacterial cells were used (Set 3), significant oil biodegradation activity occurred and the difference between this treatment and that in Set 4 with added fertilizer+biosurfactant were only 4-5% higher degradation level in shake flask and 3.2-7% in microcosm experiments for all three bacterial strains used. It is concluded that, biosurfactants alone capable of promoting biodegradation to a large extent without added fertilizers, which will reduce the cost of bioremediation process and minimizes the dilution or wash away problems encountered when water soluble fertilizers used during bioremediation of aquatic environments.

  14. Pseudomonas aeruginosa in a neonatal intensive care unit: molecular epidemiology and infection control measures

    PubMed Central

    2009-01-01

    Background Pseudomonas aeruginosa, a non-fermentative, gram-negative rod, is responsible for a wide variety of clinical syndromes in NICU patients, including sepsis, pneumonia, meningitis, diarrhea, conjunctivitis and skin infections. An increased number of infections and colonisations by P. aeruginosa has been observed in the neonatal intensive care unit (NICU) of our university hospital between 2005 and 2007. Methods Hand disinfection compliance before and after an educational programme on hand hygiene was evaluated. Identification of microrganisms was performed using conventional methods. Antibiotic susceptibility was evaluated by MIC microdilution. Genotyping was performed by PFGE analysis. Results The molecular epidemiology of Pseudomonas aeruginosa in the NICU of the Federico II University hospital (Naples, Italy) and the infection control measures adopted to stop the spreading of P. aeruginosa in the ward were described. From July 2005 to June 2007, P. aeruginosa was isolated from 135 neonates and caused severe infections in 11 of them. Macrorestriction analysis of clinical isolates from 90 neonates identified 20 distinct genotypes, one major PFGE type (A) being isolated from 48 patients and responsible for 4 infections in 4 of them, four other distinct recurrent genotypes being isolated in 6 to 4 patients. Seven environmental strains were isolated from the hand of a nurse and from three sinks on two occasions, two of these showing PFGE profiles A and G identical to two clinical isolates responsible for infection. The successful control of the outbreak was achieved through implementation of active surveillance of healthcare-associated infections in the ward together with environmental microbiological sampling and an intense educational programme on hand disinfection among the staff members. Conclusion P. aeruginosa infections in the NICU were caused by the cross-transmission of an epidemic clone in 4 neonates, and by the selection of sporadic clones in 7

  15. Successful implementation of infection control strategies prevents P. aeruginosa transmission among cystic fibrosis patients inside the hospital

    PubMed Central

    Matt, Benedikt; Mitteregger, Dieter; Renner, Sabine; Presterl, Elisabeth; Assadian, Ojan; Diab-Elschahawi, Magda

    2014-01-01

    Background: The aim of this study was to characterise the epidemiology of P. aeruginosa isolated from cystic fibrosis (CF) patients at the Vienna General Hospital (VGH) by molecular genetic fingerprinting in order to understand transmission ways and to evaluate the established infection control protocols. Methods: The outpatient clinic for CF patients at the VGH cares for children and adolescents up to the age of 18 years. Among an average of 139 patients cared for at the clinic, 41 were tested positive for P. aeruginosa during the study period. Fifty P. aeruginosa isolates, obtained between August 2010 and March 2012 from routine examinations of CF patients, were subject to molecular characterization using the DiversiLab® method. Results: 42 distinguishable molecular-biological patterns were identified, 7 of which were found multiple times. 40 out of 42 genotypes were retrieved from single patients only, while two patterns were present in two patients each. Nine patients presented with two or more phenotypically diverse P. aeruginosa isolates. In five of these cases the retrieved isolates belonged to the same genotype. Conclusion: The broad genetic heterogeneity of P. aeruginosa in the studied patient population suggests that the majority of CF patients cared for at the VGH acquire P. aeruginosa from environmental sources. It may be concluded that implemented infection control guidelines have been successful in preventing nosocomial transmission of P. aeruginosa among CF patients within the VGH and patient-to-patient transmission outside the hospital. Chronic polyclonal infection/colonization was rare in the study population. PMID:25285264

  16. Efflux-mediated fluoroquinolone resistance in the multidrug-resistant Pseudomonas aeruginosa clinical isolate PA7: identification of a novel MexS variant involved in upregulation of the mexEF-oprN multidrug efflux operon

    PubMed Central

    Morita, Yuji; Tomida, Junko; Kawamura, Yoshiaki

    2014-01-01

    The emergence of multidrug-resistant Pseudomonas aeruginosa has become a serious problem in medical settings. P. aeruginosa clinical isolate PA7 is resistant to fluoroquinolones, aminoglycosides, and most β-lactams but not imipenem. In this study, enhanced efflux-mediated fluoroquinolone resistance of PA7 was shown to reflect increased expression of two resistance nodulation cell division (RND) -type multidrug efflux operons, mexEF-oprN and mexXY-oprA. Such a clinical isolate has rarely been reported because MexEF-OprN-overproducing mutants often increase susceptibility to aminoglycosides apparently owing to impairment of the MexXY system. A mutant of PA7 lacking three RND-type multidrug efflux operons (mexAB-oprM, mexEF-oprN, and mexXY-oprA) was susceptible to all anti-pseudomonas agents we tested, supporting an idea that these RND-type multidrug efflux transporters are molecular targets to overcome multidrug resistance in P. aeruginosa. mexEF-oprN-upregulation in P. aeruginosa PA7 was shown due to a MexS variant harboring the Valine-155 amino acid residue. This is the first genetic evidence shown that a MexS variant causes mexEF-oprN-upregulation in P. aeruginosa clinical isolates. PMID:25653649

  17. Legionella pneumophila serogroup 12 isolated from human and environmental sources.

    PubMed Central

    Thacker, W L; Wilkinson, H W; Benson, R F; Brenner, D J

    1987-01-01

    A Legionella-like organism (strain 570-CO-H [= ATCC 43290]) isolated from the lung tissue of a patient with pneumonia was shown by growth, as well as physiological, serological, and genetic characteristics, to belong to a new Legionella pneumophila serogroup, serogroup 12. Two additional strains were detected with antiserum specific for strain 570-CO-H. These strains were isolated from environmental sources. PMID:3571461

  18. Antibiotic resistance pattern and evaluation of metallo-beta lactamase genes (VIM and IMP) in Pseudomonas aeruginosa strains producing MBL enzyme, isolated from patients with secondary immunodeficiency

    PubMed Central

    Shirani, Kiana; Ataei, Behrouz; Roshandel, Fardad

    2016-01-01

    Background: One of the most common causes of hospital-acquired secondary infections in hospitalized patients is Pseudomonas aeruginosa. The aim of this study is to evaluate the expression of IMP and VIM in Pseudomonas aeruginosa strains (carbapenem resistant and producer MBL enzyme) in patients with secondary immunodeficiency. Materials and Methods: In a cross sectional study, 96 patients with secondary immunodeficiency hospitalized in the Al-Zahra hospital were selected. Carbapenem resistant strains isolated and modified Hodge test was performed in order to confirm the presence of the metallo carbapenemase enzyme. Under the standard conditions they were sent to the central laboratory for investigating nosocomial infection Multiplex PCR. Results: Of 96 samples 28.1% were IMP positive, 5.2% VIM positive and 3.1% both VIM and IMP positive. The prevalence of multidrug resistance in the IMP and/or VIM negative samples was 29%, while all 5 VIM positive samples have had multidrug resistance. Also the prevalence of multi-drug resistance in IMP positive samples were 96.3% and in IMP and VIM positive samples were 100%. According to Fisher’s test, the prevalence of multi-drug resistance based on gene expression has significant difference (P < 0.001). Conclusion: Based on the results of this study it can be concluded that, a significant percentage of patients with secondary immunodeficiency that suffer nosocomial infections with multidrug resistance, especially Pseudomonas aeruginosa, are probably MBL-producing gene positive. Therefore the cause of infection should be considered in the hospital care system to identify their features, the presence of genes involved in the development of multi-drug resistance and antibiotic therapy. PMID:27563634

  19. Antimicrobial susceptibility of equine and environmental isolates of Clostridium difficile.

    PubMed

    Båverud, V; Gunnarsson, A; Karlsson, M; Franklin, A

    2004-01-01

    The antimicrobial susceptibility of 50 Clostridium difficile isolates, 36 of them from horse feces and 14 from environmental sites, was determined by broth microdilution. The antimicrobial agents tested were avilamycin, cephalothin, chloramphenicol, clindamycin, erythromycin, gentamicin, neomycin, oxacillin, oxytetracycline, penicillin, spiramycin, streptomycin, trimethoprim/sulfamethoxazole, vancomycin, and virginiamycin. All isolates were susceptible to vancomycin (MIC isolates, the MICs of erythromycin (MIC > 16 microg/ml), oxytetracycline (MIC >/=32 microg/ml), spiramycin (MIC > 16 microg/ml), and virginiamycin (MIC 8-16 microg/ml) were higher for 18 isolates. Those were mainly isolated from horses at animal hospitals and further from environmental sites at a stud farm. In contrast, all isolates, except one, from healthy foals had low MICs of erythromycin, spiramycin, virginiamycin, and oxytetracycline. The isolates from soil in public parks had also low MICs of these antimicrobial agents. Broth microdilution appeared both reliable and reproducible for susceptibility testing of C. difficile. The method was also readily performed and the MIC endpoints were easily read.

  20. Predominance of carbapenem-resistant Pseudomonas aeruginosa isolates carrying blaIMP and blaVIM metallo-β-lactamases in a major hospital in Costa Rica.

    PubMed

    Toval, Francisco; Guzmán-Marte, Anel; Madriz, Vivian; Somogyi, Teresita; Rodríguez, César; García, Fernando

    2015-01-01

    This study aimed to assess the molecular basis of the resistance to carbapenems in clinical isolates of Pseudomonas aeruginosa recovered from a tertiary-level health facility in San José, Costa Rica. A total of 198 non-duplicated isolates were evaluated for their susceptibility to β-lactams, aminoglycosides and fluoroquinolones. The production of metallo-β-lactamases (MBLs), the presence of MBL encoding genes (blaIMP, blaVIM and blaGIM-1) and the occurrence of these genes within class 1 integrons were investigated. In addition, an ERIC2 PCR fingerprinting method was used to elucidate the distribution of the detected MBL genes within the strain collection. Of the 198 isolates tested, 125 (63.1 %) were categorized as carbapenem-resistant. The majority (88.8 %) of the carbapemen-resistant isolates also showed resistance to ceftazidime, cefepime, aztreonam, ticarcillin/clavulanic acid, amikacin, gentamicin, tobramycin, ciprofloxacin and gatifloxacin. Among the carbapenem-resistant isolates, 102 (81.6 %) showed MBL activity. Strikingly, both blaIMP and blaVIM genes were simultaneously detected in most (94.1 %) of the 102 MBL producers. Five carbapenem-resistant MBL producers were positive only for blaIMP genes. Almost 70 % of the isolates examined harboured the intI1 gene, accompanied by the sul1 and qacEΔ1 genes in 136 (99 %) and 122 (89 %) isolates, respectively. The majority (94.4 %) of the carbapenem-resistant isolates carried the intI1 gene, in contrast to 26 % of the carbapenem-susceptible isolates. Ninety-three out of 96 (96.9 %) isolates carrying both blaIMP and blaVIM genes also harboured the intI1, sul1 and qacEΔ1 genes. Gene cassettes from carbapenem-susceptible and MBL-negative carbapenem-resistant isolates encoded aminoglycoside-resistance enzymes (aadA2, aadA4 and aadA6) as well as orfD and qacF genes. RAPD analysis distributed 126 of the isolates in 29 clusters. Eighty of the 90 blaIMP (+) blaVIM (+) isolates were sorted into 16

  1. A major Pseudomonas aeruginosa clone common to patients and aquatic habitats.

    PubMed Central

    Römling, U; Wingender, J; Müller, H; Tümmler, B

    1994-01-01

    The genomic relatedness of 573 Pseudomonas aeruginosa strains from environmental and clinical habitats was examined by digesting the genome with the rare-cutting enzyme SpeI. Thirty-nine strains were collected from environmental habitats mainly of aquatic origin, like rivers, lakes, or sanitary facilities. Four hundred fifty strains were collected from 76 patients with cystic fibrosis (CF) treated at four different centers, and 25 additional clinical isolates were collected from patients suffering from other diseases. Twenty-nine P. aeruginosa isolates were collected from the environment of one CF clinic. Thirty strains from culture collections were of environmental and clinic origin. A common macrorestriction fingerprint pattern was found in 13 of 46 CF patients, 5 of 29 environmental isolates from the same hospital, in a single ear infection isolate from another hospital, and 8 of 38 isolates from aquatic habitats about 300 km away from the CF clinic. The data indicate that closely related variants of one major clone (called clone C) persisted in various spatially and temporally separated habitats. Southern analysis of the clonal variants with six gene probes and two probes for genes coding for rRNA revealed almost the same hybridization patterns. With the exception of the phenotypically rapidly evolving CF isolates, the close relatedness of the strains of the clone was also shown by their identical responses in pyocin typing, phage typing, and serotyping. Besides clone C, three other P. aeruginosa clones were isolated from more than one clinical or environmental source. Images PMID:8031075

  2. In vitro potentiation of carbapenems with ME1071, a novel metallo-beta-lactamase inhibitor, against metallo-beta-lactamase- producing Pseudomonas aeruginosa clinical isolates.

    PubMed

    Ishii, Yoshikazu; Eto, Maki; Mano, Yoko; Tateda, Kazuhiro; Yamaguchi, Keizo

    2010-09-01

    ME1071, a maleic acid derivative, is a novel specific inhibitor for metallo-beta-lactamases (MBL). In this study, the potentiation of ME1071 in combination with several beta-lactams was evaluated using MBL-producing Pseudomonas aeruginosa isolates. The rates of susceptibility of MBL producers to carbapenems (imipenem, biapenem, and doripenem) and ceftazidime were increased by 8 to 27% in the presence of 32 microg/ml of ME1071. The corresponding resistance rates were decreased by 13 to 46%, respectively. On the other hand, ME1071 showed weaker or no potentiation with non-MBL producers. The K(i) value of ME1071 for IMP-1 was 0.4 microM, significantly lower than the K(m) values of carbapenems for the IMP-1 enzyme. On the other hand, the K(i) value of ME1071 for VIM-2 was 120 microM, higher than the K(m) values of carbapenems for the VIM-2 enzyme. Results of this study indicate that ME1071 can potentiate the activity of ceftazidime and carbapenems against MBL-producing strains of P. aeruginosa.

  3. Waste Isolation Pilot Plant Biennial Environmental Compliance Report

    SciTech Connect

    Washington Regulatory and Environmental Services

    2004-10-25

    This Biennial Environmental Compliance Report (BECR) documents environmental regulatory compliance at the Waste Isolation Pilot Plant (WIPP), a facility designed and authorized for the safe disposal of transuranic (TRU) radioactive waste, for the reporting period of April 1, 2002, to March 31, 2004. As required by the WIPP Land Withdrawal Act (LWA) (Public Law [Pub. L.] 102-579, as amended by Pub. L. 104-201), the BECR documents U.S. Department of Energy (DOE) compliance with applicable environmental protection laws and regulations implemented by agencies of the federal government and the state of New Mexico.

  4. Waste Isolation Pilot Plant Annual Site Environmental Report for 2010

    SciTech Connect

    2011-09-01

    The purpose of the Waste Isolation Pilot Plant (WIPP) Annual Site Environmental Report for 2010 (ASER) is to provide information required by U.S. Department of Energy (DOE) Order 231.1A, Environment, Safety, and Health Reporting. Specifically, the ASER presents summary environmental data to: (1) Characterize site environmental management performance. (2) Summarize environmental occurrences and responses reported during the calendar year. (3) Confirm compliance with environmental standards and requirements. (4) Highlight significant environmental accomplishments, including progress toward the DOE Environmental Sustainability Goals made through implementation of the WIPP Environmental Management System (EMS). The DOE Carlsbad Field Office (CBFO) and the management and operating contractor (MOC), Washington TRU Solutions LLC (WTS), maintain and preserve the environmental resources at the WIPP. DOE Order 231.1A; DOE Order 450.1A, Environmental Protection Program; and DOE Order 5400.5, Radiation Protection of the Public and the Environment, require that the affected environment at and near DOE facilities be monitored to ensure the safety and health of the public and workers, and preservation of the environment. This report was prepared in accordance with DOE Order 231.1A, which requires that DOE facilities submit an ASER to the DOE Headquarters Chief Health, Safety, and Security Officer. The WIPP Hazardous Waste Facility Permit Number NM4890139088-TSDF (Permit) further requires that the ASER be provided to the New Mexico Environment Department (NMED).

  5. Genotypic diversity of environmental Cryptococcus neoformans isolates from Northern Portugal.

    PubMed

    Ferreira, Ana Sofia; Sampaio, Ana; Maduro, Ana Paula; Silva, Inês; Teles, Fernando; Martins, Maria da Luz; Inácio, João

    2014-02-01

    The Cryptococcus neoformans/C. gattii species complex members are the main agents of systemic cryptococcosis. This disease is believed to be acquired from the environment via fungal cell inhalation. Often, isolates recovered from environmental and clinical sources have proven to be genotypically similar. We assessed the occurrence of C. neoformans and C. gattii in environmental substrates collected in a Portuguese region. Twenty-eight isolates were identified as C. neoformans - five from decaying Eucalyptus leaves and 23 from domestic pigeon droppings. The isolates were genotyped using a URA5-RFLP approach. The C. neoformans VNIV (53.6%, n = 15) and VNI (32.1%, n = 9) genotypes were abundantly present among environmental isolates. The hybrid VNIII (14.3%, n = 4) genotype was underrepresented and the VNII was not found. Cryptococcus gattii was also not found although some isolates yielded a positive canavanine-glycine-bromothymol blue test.

  6. Waste Isolation Pilot Plant Site Environmental Report Calendar Year 2002

    SciTech Connect

    Washington Regulatory and Environmental Services

    2003-09-17

    The United States (U.S.) Department of Energy (DOE) Carlsbad Field Office (CBFO) and Washington TRU Solutions LLC (WTS) are dedicated to maintaining high quality management of Waste Isolation Pilot Plant (WIPP) environmental resources. DOE Order 5400.1, General Environmental Protection Program, and DOE Order 231.1, Environment, Safety, and Health Reporting, require that the environment at and near DOE facilities be monitored to ensure the safety and health of the public and the environment. This Waste Isolation Pilot Plant 2002 Site Environmental Report summarizes environmental data from calendar year 2002 that characterize environmental management performance and demonstrate compliance with federal and state regulations. This report was prepared in accordance with DOE Order 5400.1, DOE Order 231.1, and Guidance for the Preparation of DOE Annual Site Environmental Reports (ASERs) for Calendar Year 2002 (DOE Memorandum EH-41: Natoli:6-1336, April 4, 2003). These Orders and the guidance document require that DOE facilities submit an annual site environmental report to DOE Headquarters, Office of the Assistant Secretary for Environment, Safety, and Health; and the New Mexico Environment Department (NMED).

  7. Draft Genome Sequence of Textile Azo Dye-Decolorizing and -Degrading Pseudomonas aeruginosa Strain PFK10, Isolated from the Common Effluent Treatment Plant of the Ankleshwar Industrial Area of Gujarat, India.

    PubMed

    Faldu, P R; Kothari, V V; Kothari, C R; Rawal, C M; Domadia, K K; Patel, P A; Bhimani, H D; Raval, V H; Parmar, N R; Nathani, N M; Koringa, P G; Joshi, C G; Kothari, R K

    2014-02-06

    Here, we report the draft genome sequence of Pseudomonas aeruginosa strain PFK10, isolated from the common effluent treatment plant (CETP) of the Ankleshwar industrial area of Gujarat, India. The 6.04-Mb draft genome sequence of strain PFK10 provides information about the genes encoding enzymes that enable the strain to decolorize and degrade textile azo dye.

  8. Draft Genome Sequence of Textile Azo Dye-Decolorizing and -Degrading Pseudomonas aeruginosa Strain PFK10, Isolated from the Common Effluent Treatment Plant of the Ankleshwar Industrial Area of Gujarat, India

    PubMed Central

    Faldu, P. R.; Kothari, V. V.; Kothari, C. R.; Rawal, C. M.; Domadia, K. K.; Patel, P. A.; Bhimani, H. D.; Raval, V. H.; Parmar, N. R.; Nathani, N. M.; Koringa, P. G.; Joshi, C. G.

    2014-01-01

    Here, we report the draft genome sequence of Pseudomonas aeruginosa strain PFK10, isolated from the common effluent treatment plant (CETP) of the Ankleshwar industrial area of Gujarat, India. The 6.04-Mb draft genome sequence of strain PFK10 provides information about the genes encoding enzymes that enable the strain to decolorize and degrade textile azo dye. PMID:24503984

  9. Pre-adapting parasitic phages to a pathogen leads to increased pathogen clearance and lowered resistance evolution with Pseudomonas aeruginosa cystic fibrosis bacterial isolates.

    PubMed

    Friman, V-P; Soanes-Brown, D; Sierocinski, P; Molin, S; Johansen, H K; Merabishvili, M; Pirnay, J-P; De Vos, D; Buckling, A

    2016-01-01

    Recent years have seen renewed interest in phage therapy--the use of viruses to specifically kill disease-causing bacteria--because of the alarming rise in antibiotic resistance. However, a major limitation of phage therapy is the ease at with bacteria can evolve resistance to phages. Here, we determined whether in vitro experimental coevolution can increase the efficiency of phage therapy by limiting the resistance evolution of intermittent and chronic cystic fibrosis Pseudomonas aeruginosa lung isolates to four different phages. We first pre-adapted all phage strains against all bacterial strains and then compared the efficacy of pre-adapted and nonadapted phages against ancestral bacterial strains. We found that evolved phages were more efficient in reducing bacterial densities than ancestral phages. This was primarily because only 50% of bacterial strains were able to evolve resistance to evolved phages, whereas all bacteria were able to evolve some level of resistance to ancestral phages. Although the rate of resistance evolution did not differ between intermittent and chronic isolates, it incurred a relatively higher growth cost for chronic isolates when measured in the absence of phages. This is likely to explain why evolved phages were more effective in reducing the densities of chronic isolates. Our data show that pathogen genotypes respond differently to phage pre-adaptation, and as a result, phage therapies might need to be individually adjusted for different patients.

  10. Nosocomial outbreak of Pseudomonas aeruginosa associated with a drinking water fountain.

    PubMed

    Costa, D; Bousseau, A; Thevenot, S; Dufour, X; Laland, C; Burucoa, C; Castel, O

    2015-11-01

    Over a four-month period, ten patients were suspected of having acquired nosocomial infection to P. aeruginosa in the ear, nose, and throat department. Environmental and clinical isolates were compared. Only water from a drinking water fountain was contaminated by P. aeruginosa. This isolate and those of three patients had indistinguishable random amplified polymorphic DNA profiles. These patients had serious oncology diseases. The drinking water fountain was used for their alimentation by percutaneous endoscopic gastrostomy and was the origin of the outbreak. Another type of drinking fountain with a terminal ultraviolet treatment was installed, following which no new infections linked to drinking water were identified.

  11. Genomic Characterization of Human and Environmental Polioviruses Isolated in Albania

    PubMed Central

    Divizia, Maurizio; Palombi, Leonardo; Buonomo, Ersilia; Donia, Domenica; Ruscio, Vito; Equestre, Michele; Leno, Luljeta; Panà, Augusto; Degener, Anna Marta

    1999-01-01

    Between April and December 1996, a serious outbreak of poliomyelitis occurred in Albania; almost 140 subjects were involved, and the episode presented an unusually high mortality rate (12%). During the outbreak, water samples from the Lana River in Tirana, Albania, and stool samples from two cases of paralytic poliomyelitis were collected and analyzed for the presence of polioviruses. Six polioviruses were isolated from the environmental and human samples, according to standard methods. All the samples were characterized by partial genomic sequencing of 330 bases across the 5′ untranslated region (5′-UTR) (nucleotide positions 200 to 530) and of 300 bases across the VP1 region (nucleotide positions 2474 to 2774). Comparison of these sequences with those present in data banks permitted the identification of environmental isolates Lana A and Lana B as, respectively, a Sabin-like type 2 poliovirus and an intertypic recombinant poliovirus (Sabin-like type 2/wild type 1), both bearing a G instead of an A at nucleotide position 481. The two other environmental polioviruses were similar to the isolates from the paralytic cases. They were characterized by a peculiar 5′-UTR and by a VP1 region showing 98% homology with the Albanian epidemic type 1 isolates reported by other authors. This study confirms the environmental circulation in Albania of recombinant poliovirus strains, likely sustained by a massive vaccination effort and by the presence in the environment of a type 1 poliovirus, as isolated from the Lana River in Tirana about 2 months before the first case of symptomatic acute flaccid paralysis was reported in this town. PMID:10427045

  12. Sensitivity to Antimicrobial Drugs of Pseudomonas Aeruginosa Extreme-Resistant Strains Isolated in the Major Hospitals of Central Kazakhstan

    PubMed Central

    Azizov, Ilya S.; Lavrinenko, Alyona V.; Belyaev, Ilya A.; Babenko, Dmitry B.; Shambilova, Natalya A.; Bissenova, Nelya M.

    2017-01-01

    AIM: The article presents the current data on the sensitivity of the main 37 strains of eXtremaly Drugs Resistance (XDR) category to anti-pseudomonas drugs. MATERIAL AND METHODS: The strains were collected during the prospective multicenter study in large multidisciplinary hospitals of Central Kazakhstan. Susceptibility to antimicrobial drugs was carried out by disk method and the serial dilution method with the interpretation of the results according to EUCAST criteria. Detection of carbapenemases gene of VIM, IMP, NDM and GES classes was carried out by PCR method using the commercial kits. RESULTS: All identified carbapenemases were sorted to VIM class and accounted for 63.64%. Resistance to aminoglycoside drugs exceeded 80%. All the strains were susceptible to polymyxin. CONCLUSION: Thus, at the present stage the circulation of P. aeruginosa strains of XDR category continues in major hospitals in Kazakhstan. The strains remain sensitiveness only to polymyxin. PMID:28293307

  13. Waset Isolation Pilot Plant Annual Site Environmental Report for 2006

    SciTech Connect

    Washington Regulatory and Environmental Services; Washington TRU Solutions LLC

    2007-09-26

    The purpose of the Waste Isolation Pilot Plant Annual Site Environmental Report for 2006 (ASER) is to provide information required by U.S. Department of Energy (DOE) Order 231.1A, Environment, Safety, and Health Reporting. Specifically, the ASER presents summary environmental data that: (a) Characterize site environmental management performance; (b) Summarize environmental occurrences and responses reported during the calendar year; (c) Confirm compliance with environmental standards and requirements; and (d) Highlight significant facility programs and efforts. The DOE Carlsbad Field Office (CBFO) and Washington TRU Solutions LLC (WTS) maintain and preserve the environmental resources at the WIPP site. DOE Order 231.1A; DOE Order 450.1, Environmental Protection Program; and DOE Order 5400.5, Radiation Protection of the Public and Environment, require that the affected environment at and near DOE facilities be monitored to ensure the safety and health of the public and the environment. This report was prepared in accordance with DOE Order 231.1A. This order requires that DOE facilities submit an ASER to the DOE Headquarters Office of the Assistant Secretary for Environment, Safety, and Health. The WIPP Hazardous Waste Facility Permit (HWFP) (No. NM4890139088-TSDF [treatment, storage, and disposal facility]) further requires that the ASER be provided to the New Mexico Environment Department (NMED).

  14. Kinetics of nutrient enhanced crude oil degradation by Pseudomonas aeruginosa AKS1 and Bacillus sp. AKS2 isolated from Guwahati refinery, India.

    PubMed

    Chettri, Bobby; Mukherjee, Arghya; Langpoklakpam, James S; Chattopadhyay, Dhrubajyoti; Singh, Arvind K

    2016-09-01

    Bacterial degradation of crude oil in response to nutrient treatments has been vastly studied. But there is a paucity of information on kinetic parameters of crude oil degradation. Here we report the nutrient stimulated kinetic parameters of crude oil degradation assessed in terms of CO2 production and oil removal by Pseudomonas aeruginosa AKS1 and Bacillus sp. AKS2. The hydrocarbon degradation rate of P. aeruginosa AKS1 in oil only amended sediment was 10.75 ± 0.65 μg CO2-C g(-1) sediment day(-1) which was similar to degradation rate in sediments with no oil. In presence of both inorganic N & P, the degradation rate increased to 47.22 ± 1.32 μg CO2-C g(-1) sediment day(-1). The half-saturation constant (Ks) and maximum degradation rate (Vmax) for P. aeruginosa AKS1 under increasing N and saturating P concentration were 13.57 ± 0.53 μg N g(-1) sediment and 39.36 ± 1.42 μg CO2-C g(-1) sediment day(-1) respectively. The corresponding values at increasing P and a constant N concentration were 1.60 ± 0.13 μg P g(-1) sediment and 43.90 ± 1.03 μg CO2-C g(-1) sediment day(-1) respectively. Similarly the degradation rate of Bacillus sp. AKS2 in sediments amended with both inorganic nutrients N & P was seven fold higher than the rates in oil only or nutrient only treated sediments. The Ks and Vmax estimates of Bacillus sp. AKS2 under increasing N and saturating P concentration were 9.96 ± 1.25 μg N g(-1) sediment and 59.96 ± 7.56 μg CO2-C g(-1) sediment day(-1) respectively. The corresponding values for P at saturating N concentration were 0.46 ± 0.24 μg P g(-1) sediment and 63.63 ± 3.54 μg CO2-C g(-1) sediment day(-1) respectively. The rates of CO2 production by both isolates were further stimulated when oil concentration was increased above 12.5 mg g(-1) sediment. However, oil degradation activity declined at oil concentration above 40 mg g(-1) sediment when treated with constant nutrient: oil ratio

  15. Detection of blaSPM-1, blaKPC, blaTEM and blaCTX-M genes in isolates of Pseudomonas aeruginosa, Acinetobacter spp. and Klebsiella spp. from cancer patients with healthcare-associated infections.

    PubMed

    Jácome, Paula Regina Luna de Araújo; Alves, Lílian Rodrigues; Jácome-Júnior, Agenor Tavares; Silva, Maria Jesuíta Bezerra da; Lima, Jailton Lobo da Costa; Araújo, Paulo Sérgio Ramos; Lopes, Ana Catarina S; Maciel, Maria Amélia Vieira

    2016-07-01

    Pseudomonas aeruginosa, Acinetobacter spp. and Klebsiella spp. are three of the pathogens most frequently involved in infections of cancer patients, and the production of β -lactamases is a major mechanism of resistance due to its wide diversity of existing enzymes. Therefore, the aim of the present study was to investigate the microbiological profile and data related to patients and infections, and to search for β -lactamase genes in bacterial isolates from hospitalized cancer patients in a hospital in Recife, Pernambuco, Brazil. A total of 169 isolates were recovered between 2012 and 2014, of which 58 were P. aeruginosa, 36 were Acinetobacter spp. and 75 were Klebsiella spp. A high percentage of carbapenem resistance was observed in P. aeruginosa and Acinetobacter spp. Among the carbapenem-resistant bacteria, the blaSPM-1 gene was detected in P. aeruginosa (35.5 %) and Acinetobacter spp. (3.8 %), while blaKPC was detected in P. aeruginosa (25.8 %) only. Among the third- and fourth-generation cephalosporin-resistant strains, in Klebsiella spp. we detected the genes blaTEM (30.6 %), blaCTX-M (58.3 %) and blaKPC (5.6 %), and in Acinetobacter spp. only blaTEM (25.9 %). This the first report of an Acinetobacter baumannii blaSPM-1 gene carrier that has been isolated in Brazil. The most frequent cancer types were bowel tumour [14.8 %; 95 % confidence interval (CI95 %) 9.8-21.1 %], breast cancer (13.6 %; CI95 % 8.8-19.7 %) and prostate cancer (11.2%; CI95 % 6.9-17.0 %). These results therefore provide knowledge of susceptibility profile and resistance mechanisms and thus can contribute to the strategic formulation of hospital infection control plans and the rational use of antimicrobials, reducing mortality from infection levels in cancer patients.

  16. Extracellular biogenic nanomaterials inhibit pyoverdine production in Pseudomonas aeruginosa: a novel insight into impacts of metal(loid)s on environmental bacteria.

    PubMed

    Mohanty, Anee; Liu, Yang; Yang, Liang; Cao, Bin

    2015-02-01

    Anthropogenic activities such as mining, smelting, and industrial use have caused serious problems of metal(loid) pollution in nearly every country in the world. A wide range of environmental microorganisms are capable of transforming metal(loid)s into nanomaterials, i.e., biogenic nanomaterials (bio-NMs), in the environment. Although the impacts of various metal(loid)s on the ecosystems have been extensively studied, the potential influence of the bio-NMs generated in the environment to environmental organisms is largely unexplored. Using tellurium nanomaterials transformed from tellurite by a metal-reducing bacterium as model bio-NMs, we demonstrated that the bio-NMs significantly decreased siderophore production in an environmental bacterium Pseudomonas aeruginosa in both planktonic cultures and biofilms. Transcriptomic analysis revealed that the bio-NMs inhibited the expression of genes involved in biosynthesis and transport of siderophores. Siderophores secreted by certain bacteria in microbial communities can be considered as public goods that can be exploited by local communities, playing an important role in shaping microbial communities. The inhibition of siderophore production by the bio-NMs implies that bio-NMs may have an important influence on the ecosystems through altering specific functions of environmental bacteria. Taken together, this study provides a novel insight into the environmental impacts of metal(loid)s.

  17. Minimum inhibitory concentration distribution in environmental Legionella spp. isolates.

    PubMed

    Sandalakis, Vassilios; Chochlakis, Dimosthenis; Goniotakis, Ioannis; Tselentis, Yannis; Psaroulaki, Anna

    2014-12-01

    In Greece standard tests are performed in the watering and cooling systems of hotels' units either as part of the surveillance scheme or following human infection. The purpose of this study was to establish the minimum inhibitory concentration (MIC) distributions of environmental Legionella isolates for six antimicrobials commonly used for the treatment of Legionella infections, by MIC-test methodology. Water samples were collected from 2004 to 2011 from 124 hotels from the four prefectures of Crete (Greece). Sixty-eight (68) Legionella isolates, comprising L. pneumophila serogroups 1, 2, 3, 5, 6, 8, 12, 13, 15, L. anisa, L. rubrilucens, L. maceachernii, L. quinlivanii, L. oakridgensis, and L. taurinensis, were included in the study. MIC-tests were performed on buffered charcoal yeast extract with α-ketoglutarate, L-cysteine, and ferric pyrophosphate. The MICs were read after 2 days of incubation at 36 ± 1 °C at 2.5% CO2. A large distribution in MICs was recorded for each species and each antibiotic tested. Rifampicin proved to be the most potent antibiotic regardless of the Legionella spp.; tetracycline appeared to have the least activity on our environmental isolates. The MIC-test approach is an easy, although not so cost-effective, way to determine MICs in Legionella spp. These data should be kept in mind especially since these Legionella species may cause human disease.

  18. Evidence of the Cost of the Production of Microcystins by Microcystis aeruginosa under Differing Light and Nitrate Environmental Conditions

    PubMed Central

    Briand, Enora; Bormans, Myriam; Quiblier, Catherine; Salençon, Marie-José; Humbert, Jean-François

    2012-01-01

    The cyanobacterium Microcystis aeruginosa is known to proliferate in freshwater ecosystems and to produce microcystins. It is now well established that much of the variability of bloom toxicity is due to differences in the relative proportions of microcystin-producing and non-microcystin-producing cells in cyanobacterial populations. In an attempt to elucidate changes in their relative proportions during cyanobacterial blooms, we compared the fitness of the microcystin-producing M. aeruginosa PCC 7806 strain (WT) to that of its non-microcystin-producing mutant (MT). We investigated the effects of two light intensities and of limiting and non-limiting nitrate concentrations on the growth of these strains in monoculture and co-culture experiments. We also monitored various physiological parameters, and microcystin production by the WT strain. In monoculture experiments, no significant difference was found between the growth rates or physiological characteristics of the two strains during the exponential growth phase. In contrast, the MT strain was found to dominate the WT strain in co-culture experiments under favorable growth conditions. Moreover, we also found an increase in the growth rate of the MT strain and in the cellular MC content of the WT strain. Our findings suggest that differences in the fitness of these two strains under optimum growth conditions were attributable to the cost to microcystin-producing cells of producing microcystins, and to the putative existence of cooperation processes involving direct interactions between these strains. PMID:22276137

  19. [Determination of associated antimicrobial resistance in clinical isolates of Staphylococcus aureus and Pseudomonas aeruginosa in a public hospital in Goiânia, State of Goiás].

    PubMed

    Kobayashi, Cláudia Castelo Branco Artiaga; Sadoyama, Geraldo; Vieira, José Daniel Gonçalves

    2009-01-01

    This study evaluated the associated antimicrobial resistance of Pseudomonas aeruginosa and Staphylococcus aureus in relation to an antimicrobial agent with other drugs. The associated antimicrobial resistance was calculated by means of the relative risk. There was an obvious relationship between oxacillin resistance and resistance to other antimicrobial agents among isolates of oxacillin-resistant Staphylococcus aureus (68.5%), greater than 32%, except for linezolid (6.7%). Pronounced associated resistance among drugs was observed for Pseudomonas aeruginosa isolates, particularly for ciprofloxacin and carbapenems (59.6% to 60.7%) and for aminoglycosides and carbapenems (66.3 % to 67.7 %) and other beta-lactam antibiotics (52.3% to 85.8%). The present study emphasizes the importance of diagnostic cultures and susceptibility testing for selecting the correct antimicrobial agent, with regard to the clinical impact of increased multiresistance and selection of associated antimicrobial resistance.

  20. Final environmental impact statement. Waste Isolation Pilot Plant

    SciTech Connect

    Not Available

    1980-10-01

    This volume contains the appendices for the Final Environmental Impact Statement for the Waste Isolation Pilot Plant (WIPP). Alternative geologic environs are considered. Salt, crystalline rock, argillaceous rock, and tuff are discussed. Studies on alternate geologic regions for the siting of WIPP are reviewed. President Carter's message to Congress on the management of radioactive wastes and the findings and recommendations of the interagency review group on nuclear waste management are included. Selection criteria for the WIPP site including geologic, hydrologic, tectonic, physicochemical compatability, and socio-economic factors are presented. A description of the waste types and the waste processing procedures are given. Methods used to calculate radiation doses from radionuclide releases during operation are presented. A complete description of the Los Medanos site, including archaeological and historic aspects is included. Environmental monitoring programs and long-term safety analysis program are described. (DMC)

  1. Waste Isolation Pilot Plant Biennial Environmental Compliance Report

    SciTech Connect

    Washington Regulatory and Environmental Services

    2006-10-12

    This Biennial Environmental Compliance Report (BECR) documents compliance with environmental regulations at the Waste Isolation Pilot Plant (WIPP), a facility designed and authorized for the safe disposal of transuranic (TRU) radioactive waste. This BECR covers the reporting period from April 1, 2004, to March 31, 2006. As required by the WIPP Land Withdrawal Act (LWA) (Public Law [Pub. L.] 102-579, as amended by Pub. L. 104-201), the BECR documents United States (U.S.) Department of Energy (DOE) compliance with regulations and permits issued pursuant to the following: (1) Title 40 Code of Federal Regulations (CFR) Part 191, Subpart A, "Environmental Standards for Management and Storage"; (2) Clean Air Act (CAA) (42 United States Code [U.S.C.] §7401, et seq.); (3) Solid Waste Disposal Act (SWDA) (42 U.S.C. §§6901-6992, et seq.); (4) Safe Drinking Water Act (SDWA) (42 U.S.C. §§300f, et seq.); (5) Toxic Substances Control Act (TSCA) (15 U.S.C. §§2601, et seq.); (6) Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) (42 U.S.C. §§9601, et seq.); and all other federal and state of New Mexico laws pertaining to public health and safety or the environment.

  2. Pseudomonas aeruginosa Biofilm Formation and Persistence, along with the Production of Quorum Sensing-Dependent Virulence Factors, Are Disrupted by a Triterpenoid Coumarate Ester Isolated from Dalbergia trichocarpa, a Tropical Legume.

    PubMed

    Rasamiravaka, Tsiry; Vandeputte, Olivier M; Pottier, Laurent; Huet, Joelle; Rabemanantsoa, Christian; Kiendrebeogo, Martin; Andriantsimahavandy, Abel; Rasamindrakotroka, Andry; Stévigny, Caroline; Duez, Pierre; El Jaziri, Mondher

    2015-01-01

    Recently, extracts of Dalbergia trichocarpa bark have been shown to disrupt P. aeruginosa PAO1 quorum sensing (QS) mechanisms, which are key regulators of virulence factor expression and implicated in biofilm formation. One of the active compounds has been isolated and identified as oleanolic aldehyde coumarate (OALC), a novel bioactive compound that inhibits the formation of P. aeruginosa PAO1 biofilm and its maintenance as well as the expression of the las and rhl QS systems. Consequently, the production of QS-controlled virulence factors including, rhamnolipids, pyocyanin, elastase and extracellular polysaccharides as well as twitching and swarming motilities is reduced. Native acylhomoserine lactones (AHLs) production is inhibited by OALC but exogenous supply of AHLs does not restore the production of virulence factors by OALC-treated cultures, indicating that OALC exerts its effect beyond AHLs synthesis in the QS pathways. Further experiments provided a significant inhibition of the global virulence factor activator gacA by OALC. OALC disorganizes established biofilm structure and improves the bactericidal activity of tobramycin against biofilm-encapsulated PAO1 cells. Finally, a significant reduction of Caenorhabditis elegans paralysis was recorded when the worms were infected with OALC-pre-treated P. aeruginosa. Taken together, these results show that triterpenoid coumarate esters are suitable chemical backbones to target P. aeruginosa virulence mechanisms.

  3. Pseudomonas aeruginosa Biofilm Formation and Persistence, along with the Production of Quorum Sensing-Dependent Virulence Factors, Are Disrupted by a Triterpenoid Coumarate Ester Isolated from Dalbergia trichocarpa, a Tropical Legume

    PubMed Central

    Pottier, Laurent; Huet, Joelle; Rabemanantsoa, Christian; Kiendrebeogo, Martin; Andriantsimahavandy, Abel; Rasamindrakotroka, Andry; Stévigny, Caroline; Duez, Pierre; El Jaziri, Mondher

    2015-01-01

    Recently, extracts of Dalbergia trichocarpa bark have been shown to disrupt P. aeruginosa PAO1 quorum sensing (QS) mechanisms, which are key regulators of virulence factor expression and implicated in biofilm formation. One of the active compounds has been isolated and identified as oleanolic aldehyde coumarate (OALC), a novel bioactive compound that inhibits the formation of P. aeruginosa PAO1 biofilm and its maintenance as well as the expression of the las and rhl QS systems. Consequently, the production of QS-controlled virulence factors including, rhamnolipids, pyocyanin, elastase and extracellular polysaccharides as well as twitching and swarming motilities is reduced. Native acylhomoserine lactones (AHLs) production is inhibited by OALC but exogenous supply of AHLs does not restore the production of virulence factors by OALC-treated cultures, indicating that OALC exerts its effect beyond AHLs synthesis in the QS pathways. Further experiments provided a significant inhibition of the global virulence factor activator gacA by OALC. OALC disorganizes established biofilm structure and improves the bactericidal activity of tobramycin against biofilm-encapsulated PAO1 cells. Finally, a significant reduction of Caenorhabditis elegans paralysis was recorded when the worms were infected with OALC-pre-treated P. aeruginosa. Taken together, these results show that triterpenoid coumarate esters are suitable chemical backbones to target P. aeruginosa virulence mechanisms. PMID:26186595

  4. Differences in antimicrobial susceptibility breakpoints for Pseudomonas aeruginosa, isolated from blood cultures, set by the Clinical and Laboratory Standards Institute (CLSI) and the Japanese Society of Chemotherapy.

    PubMed

    Nakamura, Tatsuya; Shimizu, Chihiro; Kasahara, Mayumi; Nakata, Chiyo; Munakata, Machiko; Takahashi, Hakuo

    2007-02-01

    A study was made of the antimicrobial susceptibility to and efficacy of various kinds of antimicrobial agents against 179 strains of Pseudomonas aeruginosa that were isolated from blood cultures at Kansai Medical University Hospital from 1990 through 2004. The annual detection rate was highest in 1994, at 22 strains (6.5%). There were 9 multidrug resistant strains of Pseudomonas aeruginosa (5.0%). Among 14 antimicrobial agents tested for measurements, ciprofloxacin (CPFX) showed the best minimum inhibitory concentration (MIC) 50 value, of 0.25 microg/ml, followed by pazufloxacin (PZFX) and biapenem (BIPM), each at 0.5 microg/ml. When the period of 15 years was divided into three stages, the MIC50 value for each antimicrobial agent was highest in the middle stage (1995 to 1999). Assuming that the percentage of sensitive strains according to the breakpoints set by the Clinical and Laboratory Standards Institute (CLSI) represents the antimicrobial susceptibility rate, amikacin (AMK) showed the best value, of 85.5%. According to the sepsis breakpoint set by the Japanese Society of Chemotherapy (JSC), the efficacy of CPFX showed the highest rate (77.1%) of all the antimicrobial agents tested. Among beta-lactams, BIPM showed the highest efficacy rate, of 67.0%. When the efficacy rates were compared with each other, the difference in efficacy rate between the breakpoint set by the CLSI and the sepsis breakpoint set by the JSC was large for beta-lactams. Comparisons made based on the CLSI criteria showed no difference in cross-resistance rates between CPFX, meropenem (MEPM), and BIPM. However, when comparisons were made using the JSC sepsis breakpoint, MEPM showed a cross-resistance rate of 87.8%, while the rate for BIPM was lower, at 56.1%, with the chi2 test showing a significant difference, at P = 0.0014. In accordance with the pharmacokinetics/pharmacodynamics theory that has been advocated, breakpoints which are more suitable for the clinical setting in Japan should

  5. Waste Isolation Pilot Plant Biennial Environmental Compliance Report

    SciTech Connect

    Westinghouse TRU Solutions

    2000-12-01

    This Biennial Environmental Compliance Report (BECR) documents environmental regulatory compliance at the Waste Isolation Pilot Plant (WIPP), a facility designed for the safe disposal of transuranic (TRU) radioactive waste, for the reporting period of April 1, 1998, to March 31, 2000. As required by the WIPP Land Withdrawal Act (LWA)(Public Law [Pub. L.] 102-579, and amended by Pub. L. 104-201), the BECR documents U.S. Department of Energy (DOE) Carlsbad Area Office's (hereinafter the ''CAO'') compliance with applicable environmental protection laws and regulations implemented by agencies of the federal government and the state of New Mexico. An issue was identified in the 1998 BECR relating to a potential cross-connection between the fire-water systems and the site domestic water system. While the CAO and its managing and operating contractor (hereinafter the ''MOC'') believe the site was always in compliance with cross-connection control requirements, hardware and procedural upgrades w ere implemented in March 1999 to strengthen its compliance posture. Further discussion of this issue is presented in section 30.2.2 herein. During this reporting period WIPP received two letters and a compliance order alleging violation of certain requirements outlined in section 9(a)(1) of the LWA. With the exception of one item, pending a final decision by the New Mexico Environment Department (NMED), all alleged violations have been resolved without the assessment of fines or penalties. Non-mixed TRU waste shipments began on March 26, 1999. Shipments continued through November 26, 1999, the effective date of the Waste Isolation Pilot Plant Hazardous Waste Facility Permit (NM4890139088-TSDF). No shipments regulated under the Hazardous Waste Facility Permit were received at WIPP during this BECR reporting period.

  6. Characterization and survival of environmental Escherichia coli O26 isolates in ground beef and environmental samples.

    PubMed

    Palmer, Christine E; Bratcher, Christy L; Singh, Manpreet; Wang, Luxin

    2015-04-01

    In addition to Escherichia coli O157:H7, shiga toxin-producing E. coli (STEC) O26 was added to the zero-tolerance adulterant list together with other 5 non-O157 STEC serogroups in 2012. Four farm O26 isolates were used in this study; they were obtained from a on-farm survey study conducted in Alabama. The presence of 3 major pathogenic genes (stx1, stx2, and eaeA) was determined through multiplex polymerase chain reaction (PCR). Two major pathogenic gene profiles were observed: 3 of the farm isolates contain only the eaeA gene whereas 1 farm isolate has both the eaeA and the stx1 genes. No significant difference was seen among the 4 farm isolates in the antibiotic resistance tests. To test their survival in ground beef and environmental samples, 2 inoculums were prepared and inoculated at various concentrations into samples of ground beef, bovine feces, bedding materials, and trough water. One inoculum was made of 3 farm isolates containing only the eaeA gene and another inoculum contained the isolate with both the eaeA and stx1 genes. Inoculated beef samples were stored at 4 °C for 10 d and the inoculated environmental samples were stored at ambient temperature for 30 d. Results showed that virulence gene profiles do not have an impact on O26's ability to survive in ground beef and in environment (P > 0.05). The inoculation levels, sample types as well as the storage times are the major factors that impact O26 survival (P < 0.05).

  7. O serotype-independent susceptibility of Pseudomonas aeruginosa to lectin-like pyocins

    PubMed Central

    Ghequire, Maarten G K; Dingemans, Jozef; Pirnay, Jean-Paul; De Vos, Daniel; Cornelis, Pierre; De Mot, René

    2014-01-01

    Lectin-like bacteriocins of the LlpA family, originally identified in plant-associated bacteria, are narrow-spectrum antibacterial proteins composed of two tandemly organized monocot mannose-binding lectin (MMBL) domains. The LlpA-like bacteriocin of Pseudomonas aeruginosa C1433, pyocin L1, lacks any similarity to known P. aeruginosa bacteriocins. The initial interaction of pyocin L1 with target cells is mediated by binding to d-rhamnose, present in the common polysaccharide antigen of lipopolysaccharides (LPS), but the actual cytotoxic mechanism is unknown. In this study, we characterized the activity range of pyocin L1 and two additional L pyocins revealed by genome mining, representing two highly diverged LlpA groups in P. aeruginosa. The recombinant proteins exhibit species-specific antagonistic activities down to nanomolar concentrations against clinical and environmental P. aeruginosa strains, including several multidrug-resistant isolates. The overlap in target strain spectrum between two close homologues of the pyocin L1 group is only minimal, contrasting with the considerable spectral redundancy of LlpA proteins reported for other Pseudomonas species. No correlation was found between L pyocin susceptibility and phylogenetic relatedness of P. aeruginosa isolates. Sensitive strains were retrieved in 13 out of 15 O serotypes tested, excluding the possibility that the highly variable and immunogenic O serotype antigen of the LPS coating would represent a dominant susceptibility-discriminating factor. PMID:25224846

  8. Final environmental impact statement. Waste Isolation Pilot Plant

    SciTech Connect

    Not Available

    1980-10-01

    In accordance with the National Environmental Policy Act (NEPA) of 1969, the US Department of Energy (DOE) has prepared this document as environmental input to future decisions regarding the Waste Isolation Pilot Plant (WIPP), which would include the disposal of transuranic waste, as currently authorized. The alternatives covered in this document are the following: (1) Continue storing transuranic (TRU) waste at the Idaho National Engineering Laboratory (INEL) as it is now or with improved confinement. (2) Proceed with WIPP at the Los Medanos site in southeastern New Mexico, as currently authorized. (3) Dispose of TRU waste in the first available repository for high-level waste. The Los Medanos site would be investigated for its potential suitability as a candidate site. This is administration policy and is the alternative preferred by the DOE. (4) Delay the WIPP to allow other candidate sites to be evaluated for TRU-waste disposal. This environmental impact statement is arranged in the following manner: Chapter 1 is an overall summary of the analysis contained in the document. Chapters 2 and 4 set forth the objectives of the national waste-management program and analyze the full spectrum of reasonable alternatives for meeting these objectives, including the WIPP. Chapter 5 presents the interim waste-acceptance criteria and waste-form alternatives for the WIPP. Chapters 6 through 13 provide a detailed description and environmental analysis of the WIPP repository and its site. Chapter 14 describes the permits and approvals necessary for the WIPP and the interactions that have taken place with Federal, State, and local authorities, and with the general public in connection with the repository. Chapter 15 analyzes the many comments received on the DEIS and tells what has been done in this FEIS in response. The appendices contain data and discussions in support of the material in the text.

  9. Molecular epidemiology of Pseudomonas aeruginosa in cystic fibrosis patients from Southeast Austria.

    PubMed

    Masoud-Landgraf, Lilian; Badura, Alexandra; Eber, Ernst; Feierl, Gebhard; Posch, Josefa; Zarfel, Gernot; Zach, Maximilian; Marth, Egon

    2012-04-01

    Pseudomonas aeruginosa is the major pathogen in the cystic fibrosis (CF) lung, the predominant source of its acquisition, however, is under discussion. In order to study the molecular epidemiology, we evaluated 86 P. aeruginosa isolates from 43 CF patients from southeast Austria. The DiversiLab system was used to identify genetic relationships among the isolates. Antibiotic susceptibilities were tested with a broth microdilution method (Micronaut Merlin). A total of 39 unrelated P. aeruginosa genotypes were found of which 34 were unique to a single patient and one was unique to a sibling pair. We found low rates of resistance for β-lactams with resistance to piperacillin/tazobactam and ceftazidime ranging from 4 to 6%. Resistance rates for meropenem and ciprofloxacin were 11% and 15%, respectively. The prevalence of multidrug-resistant isolates was 2%. We conclude that the majority of P. aeruginosa isolates from CF patients originate from environmental sources and patient-to-patient spread is very uncommon in our centre.

  10. Surface-active potential of biosurfactants produced in curd whey by Pseudomonas aeruginosa strain-PP2 and Kocuria turfanesis strain-J at extreme environmental conditions.

    PubMed

    Dubey, Kirti V; Charde, Pravin N; Meshram, Sudhir U; Shendre, Latika P; Dubey, Vijay S; Juwarkar, Asha A

    2012-12-01

    Surface-active potential of biosurfactants produced cost-effectively in curd whey by Pseudomonas aeruginosa strain-PP2 and Kocuria turfanesis strain-J were tested using parameters viz. surface tension (ST) reduction, F(CMC) (highest dilution factor to reach critical micelle concentration) and emulsification index (EI-24) of pesticides; monocrotophos and imidacloprid at extreme environmental conditions. Results have shown that ST reduction of biosurfactants was stable at pH 2-11. High F(CMC) of the biosurfactant in the fermented whey at low pH improved emulsification of pesticides. ST marginally increased at 5% and 15% NaCl, resulting in high EI-24 and F(CMC). Over a range of temperatures 30-121 °C, ST remained low with a higher F(CMC) and EI-24 at 60 °C than at 121 and 30 °C. The biosurfactants have shown differences in their surface-active property and have marked specificity to emulsify pesticides in extreme environmental conditions.

  11. Waste Isolation Pilot Plant Biennial Environmental Compliance Report

    SciTech Connect

    Washinton TRU Solutions LLC

    2002-09-30

    This Biennial Environmental Compliance Report (BECR) documents environmental regulatory compliance at the Waste Isolation Pilot Plant (WIPP), a facility designed for the safe disposal of transuranic (TRU) radioactive waste, for the reporting period of April 1, 2000, to March 31, 2002. As required by the WIPP Land Withdrawal Act (LWA)(Public Law [Pub. L.] 102-579, as amended by Pub. L. 104-201), the BECR documents U.S. Department of Energy (DOE) Carlsbad Field Office's (CBFO) compliance with applicable environmental protection laws and regulations implemented by agencies of the federal government and the state of New Mexico. In the prior BECR, the CBFO and the management and operating contractor (MOC)committed to discuss resolution of a Letter of Violation that had been issued by the New Mexico Environment Department (NMED) in August 1999, which was during the previous BECR reporting period. This Letter of Violation alleged noncompliance with hazardous waste aisle spacing, labeling, a nd tank requirements. At the time of publication of the prior BECR, resolution of the Letter of Violation was pending. On July 7, 2000, the NMED issued a letter noting that the aisle spacing and labeling concerns had been adequately addressed and that they were rescinding the violation alleging that the Exhaust Shaft Catch Basin failed to comply with the requirements for a hazardous waste tank. During the current reporting period, WIPP received a Notice of Violation and a compliance order alleging the violation of the New Mexico Hazardous Waste Regulations and the WIPP Hazardous Waste Facility Permit (HWFP).

  12. [Outbreak of nosocomial urinary tract infections due to a multidrug resistant Pseudomonas aeruginosa].

    PubMed

    Boutiba-Ben Boubaker, I; Boukadida, J; Triki, O; Hannachi, N; Ben Redjeb, S

    2003-04-01

    An outbreak of a multidrug resistant Pseudomonas aeruginosa including imipenem resistance occurred in the urology intensive care unit at Charles Nicolle Hospital (Tunis). All isolates presented the same antibiotic resistance pattern and were only susceptible to colistin. The epidemic strain was detected in different sites of this unit. Pulsed-field gel electrophoresis after enzymatic restriction using XbaI was performed in order to establish an epidemiologic link between these infections. Genotypic analysis showed two different patterns and the environmental source was identified in both cases. Although the same antibiotype was harbored by all the isolates, two outbreaks occurring in the same period were identified. The strengthening of hygiene measures allowed to stop the outbreak spreading. Since the hospital environment is the major source of Pseudomonas aeruginosa contamination, a continuous surveillance of the patients and the environmental sources is required for the implementation efficient control measures.

  13. Waste Isolation Pilot Plant 2005 Site Environmental Report

    SciTech Connect

    Washington Regulatory and Environmental Services

    2006-10-13

    The purpose of this report is to provide information needed by the DOE to assess WIPP's environmental performance and to make WIPP environmental information available to stakeholders and members of the public. This report has been prepared in accordance with DOE Order 231.1A and DOE guidance. This report documents WIPP's environmental monitoring programs and their results for 2004. The WIPP Project is authorized by the DOE National Security and Military Applications of Nuclear Energy Authorization Act of 1980 (Pub. L. 96-164). After more than 20 years of scientific study and public input, WIPP received its first shipment of waste on March 26, 1999. Located in southeastern New Mexico, WIPP is the nation's first underground repository permitted to safely and permanently dispose of TRU radioactive and mixed waste (as defined in the WIPP LWA) generated through defense activities and programs. TRU waste is defined, in the WIPP LWA, as radioactive waste containing more than 100 nanocuries (3,700 becquerels [Bq]) of alpha-emitting TRU isotopes per gram of waste, with half-lives greater than 20 years except for high-level waste, waste that has been determined not to require the degree of isolation required by the disposal regulations, and waste the U.S. Nuclear Regulatory Commission (NRC) has approved for disposal. Most TRU waste is contaminated industrial trash, such as rags and old tools; sludges from solidified liquids; glass; metal; and other materials from dismantled buildings. TRU waste is eligible for disposal at WIPP if it has been generated in whole or in part by one or more of the activities listed in the Nuclear Waste Policy Act of 1982 (42 United States Code [U.S.C.] §10101, et seq.), including naval reactors development, weapons activities, verification and control technology, defense nuclear materials production, defense nuclear waste and materials by-products management,defense nuclear materials security and safeguards and security investigations, and

  14. Occurrence of Pseudomonas aeruginosa in Kuwait soil.

    PubMed

    Al-Saleh, Esmaeil; Akbar, Abrar

    2015-02-01

    Environmentally ubiquitous bacteria such as Pseudomonas aeruginosa evolved mechanisms to adapt and prevail under diverse conditions. In the current investigation, strains of P. aeruginosa demonstrating high rates of crude oil utilization and tolerance to high concentrations of heavy metals were found in both crude oil-contaminated and uncontaminated sites in Kuwait, and were dominant in the contaminated sites. The incidence of P. aeruginosa in tested soils implies the definitive pattern of crude oil contamination in the selection of the bacterial population in petroleum-contaminated sites in Kuwait. Surprisingly, the unculturable P. aeruginosa in different soil samples showed significant high similarity coefficients based on 16S-RFLP analyses, implying that the unculturable fraction of existing bacterial population in environmental samples is more stable and, hence, reliable for phylogenetic studies compared to the culturable bacteria.

  15. Glycerol metabolism promotes biofilm formation by Pseudomonas aeruginosa.

    PubMed

    Scoffield, Jessica; Silo-Suh, Laura

    2016-08-01

    Pseudomonas aeruginosa causes persistent infections in the airways of cystic fibrosis (CF) patients. Airway sputum contains various host-derived nutrients that can be utilized by P. aeruginosa, including phosphotidylcholine, a major component of host cell membranes. Phosphotidylcholine can be degraded by P. aeruginosa to glycerol and fatty acids to increase the availability of glycerol in the CF lung. In this study, we explored the role that glycerol metabolism plays in biofilm formation by P. aeruginosa. We report that glycerol metabolism promotes biofilm formation by both a chronic CF isolate (FRD1) and a wound isolate (PAO1) of P. aeruginosa. Moreover, loss of the GlpR regulator, which represses the expression of genes involved in glycerol metabolism, enhances biofilm formation in FRD1 through the upregulation of Pel polysaccharide. Taken together, our results suggest that glycerol metabolism may be a key factor that contributes to P. aeruginosa persistence by promoting biofilm formation.

  16. Bulgecin A as a β-lactam enhancer for carbapenem-resistant Pseudomonas aeruginosa and carbapenem-resistant Acinetobacter baumannii clinical isolates containing various resistance mechanisms

    PubMed Central

    Skalweit, Marion J; Li, Mei

    2016-01-01

    Genetic screening of Pseudomonas aeruginosa (PSDA) and Acinetobacter baumannii (ACB) reveals genes that confer increased susceptibility to β-lactams when disrupted, suggesting novel drug targets. One such target is lytic transglycosylase. Bulgecin A (BlgA) is a natural product of Pseudomonas mesoacidophila and a lytic transglycosolase inhibitor that works synergistically with β-lactams targeting PBP3 for Enterobacteriaceae. BlgA also weakly inhibits di-Zn2+ metallo-β-lactamases like L1 of Stenotrophomonas maltophilia. We hypothesized that because of its unique mechanism of action, BlgA could restore susceptibility to carbapenems in carbapenem-resistant PSDA (CR-PSDA) and carbapenem-resistant ACB, as well as ACB resistant to sulbactam. A BlgA-containing extract was prepared using a previously published protocol. CR-PSDA clinical isolates demonstrating a variety of carbapenem resistance mechanisms (VIM-2 carbapenemases, efflux mechanisms, and AmpC producer expression) were characterized with agar dilution minimum inhibitory concentration (MIC) testing and polymerase chain reaction. Growth curves using these strains were prepared using meropenem, BlgA extract, and meropenem plus BlgA extract. A concentrated Blg A extract combined with low concentrations of meropenem, was able to inhibit the growth of clinical strains of CR-PSDA for strains that had meropenem MICs ≥8 mg/L by agar dilution, and a clinical strain of an OXA-24 producing ACB that had a meropenem MIC >32 mg/L and intermediate ampicillin/sulbactam susceptibility. Similar experiments were conducted on a TEM-1 producing ACB strain resistant to sulbactam. BlgA with ampicillin/sulbactam inhibited the growth of this organism. As in Enterobacteriaceae, BlgA appears to restore the efficacy of meropenem in suppressing the growth of CR-PSDA and carbapenem-resistant ACB strains with a variety of common carbapenem resistance mechanisms. BlgA extract also inhibits VIM-2 β-lactamase in vitro. BlgA may prove to be

  17. RESPONSES OF OYSTERS AND THEIR HEMOCYTES TO CLINICAL AND ENVIRONMENTAL ISOLATES OF VIBRIO PARAHAEMOLYTICUS

    EPA Science Inventory

    Interactions of Vibrio parahaemolyticus with oysters and oyster hemocytes were studied using three environmental isolates (1094, 1163 and ATCC 17802) and three clinical isolates (2030, 2062, 2107). Clinical isolates were from patients who became ill during the June 1998 food pois...

  18. Whole-Genome Sequences of 80 Environmental and Clinical Isolates of Burkholderia pseudomallei

    PubMed Central

    Baker, Anthony L.; Chain, Patrick S.; Currie, Bart J.; Daligault, Hajnalka E.; Davenport, Karen W.; Davis, Christopher B.; Inglis, Timothy J. J.; Kaestli, Mirjam; Koren, Sergey; Mayo, Mark; Merritt, Adam J.; Sarovich, Derek S.; Warner, Jeffrey

    2015-01-01

    Here, we present the draft genome sequences of 80 isolates of Burkholderia pseudomallei. The isolates represent clinical cases of melioidosis and environmental isolates from regions in Australia and Papua New Guinea where B. pseudomallei is endemic. The genomes provide further context for the diversity of the pathogen. PMID:25676747

  19. Whole-Genome Sequences of 80 Environmental and Clinical Isolates of Burkholderia pseudomallei.

    PubMed

    Johnson, Shannon L; Baker, Anthony L; Chain, Patrick S; Currie, Bart J; Daligault, Hajnalka E; Davenport, Karen W; Davis, Christopher B; Inglis, Timothy J J; Kaestli, Mirjam; Koren, Sergey; Mayo, Mark; Merritt, Adam J; Price, Erin P; Sarovich, Derek S; Warner, Jeffrey; Rosovitz, M J

    2015-02-12

    Here, we present the draft genome sequences of 80 isolates of Burkholderia pseudomallei. The isolates represent clinical cases of melioidosis and environmental isolates from regions in Australia and Papua New Guinea where B. pseudomallei is endemic. The genomes provide further context for the diversity of the pathogen.

  20. Waste Isolation Pilot Plant Annual Site Environmental Report for 2014. Emended

    SciTech Connect

    none,

    2015-09-01

    The purpose of the Waste Isolation Pilot Plant (WIPP) Annual Site Environmental Report for 2014 (ASER) is to provide information required by U.S. Department of Energy (DOE) Order 231.1B, Environment, Safety, and Health Reporting. Specifically, the ASER presents summary environmental data to: Characterize site environmental management performance; Summarize environmental occurrences and responses reported during the calendar year (CY); Confirm compliance with environmental standards and requirements; Highlight significant environmental accomplishments, including progress toward the DOE environmental sustainability goals made through implementation of the WIPP Environmental Management System (EMS).

  1. Carbenicillin resistance of Pseudomonas aeruginosa.

    PubMed Central

    Rodríguez-Tebar, A; Rojo, F; Dámaso, D; Vázquez, D

    1982-01-01

    Four strains of Pseudomonas aeruginosa obtained from clinical isolates which are carbenicillin resistant were studied to find the cause(s) of resistance to this beta-lactam antibiotic. The electrophoresis patterns of the four strains (PH20610, PH20815, PH4011, and PH4301) were found to be different from those of a wild-type strain, P. aeruginosa NCTC 10662, and appeared to lack penicillin-binding protein 2. Affinity of other penicillin-binding proteins from strains PH20610 and PH20815 for carbenicillin seemed to be normal or slightly diminished. Electrophoretic patterns of penicillin-binding proteins from strains PH4011 and PH4301 had more profound differences, since the affinities of their penicillin-binding proteins 1a, 1b, and 4 for carbenicillin were decreased by nearly two orders of magnitude relative to the preparations from the wild-type strain. Kinetic studies on binding of carbenicillin to penicillin-binding proteins both in isolated membrane preparations and in intact cells revealed that carbenicillin penetration into resistant cells was a much slower process than in susceptible cells, suggesting that the outer envelope structures serve as an efficient barrier against carbenicillin entry into our P. aeruginosa strains from clinical isolates. PMID:6821456

  2. Pharmacodynamic comparisons of antimicrobials against nosocomial isolates of escherichia coli, klebsiella pneumoniae, acinetobacter baumannii and pseudomonas aeruginosa from the MYSTIC surveillance program: the OPTAMA Program, South America 2002.

    PubMed

    Kiffer, Carlos R V; Mendes, Caio; Kuti, Joseph L; Nicolau, David P

    2004-06-01

    The OPTAMA (Optimizing Pharmacodynamic Target Attainment using the MYSTIC [Meropenem Yearly Susceptibility Test Information Collection] Antibiogram) Program provides insight into the appropriate antibiotic options for empiric therapy for common nosocomial pathogens. In this report, South America is represented by Brazil, Colombia, Peru, and Venezuela. A 5000-subject Monte Carlo Simulation estimated pharmacodynamic target attainment for meropenem, imipenem, ceftazidime, cefepime, piperacillin/tazobactam, and ciprofloxacin against Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa. Pharmacokinetic parameter variability was derived from existing healthy volunteer data, and minimum inhibitory concentration (MIC) data came from the 2002 MYSTIC program. Piperacillin/tazobactam and ciprofloxacin displayed the lowest target attainment against all bacterial species (14% to 24% for A. baumannii, 26% to 37% for P. aeruginosa, and 48% to 66% for the Enterobacteriaceae). Overall, the carbapenems had the highest probabilities of attainment against the Enterobacteriaceae (98% to 100%) and A. baumannii (73% to 74%), whereas cefepime obtained the greatest target attainment against P. aeruginosa (65%). Because no single regimen had high target attainment against A. baumannii and P. aeruginosa, the use of combination therapy to treat these pathogens in South America may be justified. Because of the lack of agreement with percent susceptibility for certain antimicrobial regimens, the use of pharmacodynamic target attainment may be a more accurate predictor of microbiologic success.

  3. Molecular epidemiological investigation of an outbreak of Pseudomonas aeruginosa infection in an SCT unit.

    PubMed

    Fanci, R; Bartolozzi, B; Sergi, S; Casalone, E; Pecile, P; Cecconi, D; Mannino, R; Donnarumma, F; Leon, A G; Guidi, S; Nicoletti, P; Mastromei, G; Bosi, A

    2009-02-01

    From May to October 2006, six severe Pseudomonas aeruginosa infections were diagnosed in patients undergoing SCT in the SCT unit of the Careggi hospital (Florence, Italy). Four of the infected patients were treated consecutively in the same room (room N). On the hypothesis of a possible environmental source of infection, samples were collected from different sites that had potential for cross-contamination throughout the SCT unit, including the electrolytic chloroxidant disinfectant used for hand washing (Irgasan) and the disinfectant used for facilities cleaning. Four of the environmental samples were positive for P. aeruginosa: three Irgansan soap samples and a tap swab sample from the staff cleaning and dressing room. The AFLP (amplified fragment length polymorphism) typing method employed to evaluate strain clonality showed that the isolates from the patients who had shared the same room and an isolate from Irgasan soap had a significant molecular similarity (dice index higher than 0.93). After adequate control measures, no subsequent environmental sample proved positive for P. aeruginosa. These data strongly support the hypothesis of the clonal origin of the infective strains and suggest an environmental source of infection. The AFLP method was fast enough to allow a 'real-time' monitoring of the outbreak, permitting additional preventive measures.

  4. Waste Isolation Pilot Plant 2003 Site Environmental Report

    SciTech Connect

    Washington Regulatory and Environmental Services

    2005-09-03

    The purpose of this report is to provide information needed by the DOE to assess WIPP's environmental performance and to convey that performance to stakeholders and members of the public. This report has been prepared in accordance with DOE Order 231.1A and DOE guidance. This report documents WIPP's environmental monitoring programs and their results for 2003. The WIPP Project is authorized by the DOE National Security and Military Applications of Nuclear Energy Authorization Act of 1980 (Pub. L. 96-164). After more than 20 years of scientific study and public input, WIPP received its first shipment of waste on March 26, 1999. Located in southeastern New Mexico, WIPP is the nation's first underground repository permitted to safely and permanently dispose of TRU radioactive and mixed waste (as defined in the WIPP LWA) generated through the research and production of nuclear weapons and other activities related to the national defense of the United States. TRU waste is defined in the WIPP LWA as radioactive waste containing more than 100 nanocuries (3,700 becquerels [Bq]) of alpha-emitting transuranic isotopes per gram of waste, with half-lives greater than 20 years. Exceptions are noted as high-level waste, waste that has been determined not to require the degree of isolation required by the disposal regulations, and waste the U.S. Nuclear Regulatory Commission (NRC) has approved for disposal. Most TRU waste is contaminated industrial trash, such as rags and old tools, and sludges from solidified liquids; glass; metal; and other materials from dismantled buildings. A TRU waste is eligible for disposal at WIPP if it has been generated in whole or in partby one or more of the activities listed in the Nuclear Waste Policy Act of 1982 (42 United States Code [U.S.C.] §10101, et seq.), including naval reactors development, weapons activities, verification and control technology, defense nuclear materials production, defense nuclear waste and materials by

  5. Antifungal susceptibility of 175 Aspergillus isolates from various clinical and environmental sources.

    PubMed

    Sabino, Raquel; Carolino, Elisabete; Veríssimo, Cristina; Martinez, Marife; Clemons, Karl V; Stevens, David A

    2016-10-01

    Some environmental Aspergillus spp. isolates have been described as resistant to antifungals, potentially causing an emerging medical problem. In the present work, the antifungal susceptibility profile of 41 clinical and 134 environmental isolates of Aspergillus was determined using the CLSI microdilution method. The aim of this study was to compare environmental and clinical isolates with respect to their susceptibility, and assess the potential implications for therapy of isolates encountered in different environments. To our knowledge, this is the first report comparing antifungal susceptibility profiles of Aspergillus collected from different environmental sources (poultries, swineries, beach sand, and hospital environment). Significant differences were found in the distribution of the different species sections for the different sources. Significant differences were also found in the susceptibility profile of the different Aspergillus sections recovered from the various sources. Clear differences were found between the susceptibility of clinical and environmental isolates for caspofungin, amphotericin B and posaconazole, with clinical isolates showing overall greater susceptibility, except for caspofungin. In comparison to clinical isolates, hospital environmental isolates showed significantly less susceptibility to amphotericin B and posaconazole. These data indicate that species section identity and the site from which the isolate was recovered influence the antifungal susceptibility profile, which may affect initial antifungal choices.

  6. The isolation of Balamuthia mandrillaris from environmental sources from Peru.

    PubMed

    Cabello-Vílchez, Alfonso Martín; Reyes-Batlle, María; Montalbán-Sandoval, Esmelda; Martín-Navarro, Carmen Ma; López-Arencibia, Atteneri; Elias-Letts, Rafaela; Guerra, Humberto; Gotuzzo, Eduardo; Martínez-Carretero, Enrique; Piñero, José E; Maciver, Sutherland K; Valladares, Basilio; Lorenzo-Morales, Jacob

    2014-07-01

    Balamuthia mandrillaris is an opportunistic free-living amoeba that has been reported to cause skin lesions and the fatal Balamuthia amoebic encephalitis (BAE) in humans and other animals. Currently, around 200 human BAE cases have been reported worldwide, although this number is considered to be underestimated. The highest number of BAE cases has been reported in the American continent, mainly in the southwest of the USA. Peru seems to be another hotspot for BAE with around 55 human cases having been identified, usually involving cutaneous infection, especially lesions in the central face area. The isolation of Balamuthia from environmental sources has been reported on only three prior occasions, twice from Californian soils and once from dust in Iran and so it seems that this amoeba is relatively rarely encountered in samples from the environment. We investigated that possibility of finding the amoebae in soil samples from different regions where clinical cases have been reported in Peru. Twenty-one samples were cultured in non-nutrient agar plates and were checked for the presence of B. mandrillaris-like trophozoites and/or cysts. Those samples that were positive for these amoebae by microscopic criteria were then confirmed by PCR amplification and DNA sequencing of the mitochondrial 16S rDNA gene of B. mandrillaris. We have detected the presence of B. mandrillaris in four samples collected in the regions of Piura (3) and Lima (1) where infection cases have been previously reported. We hypothesize that B. mandrillaris is present in Peru in soil and dust which therefore constitutes a source of the infection for the BAE cases previously reported in this country. Further studies should be carried out in the area to confirm the generality of this finding.

  7. Novel bacteriophage therapy for controlling metallo-beta-lactamase producing Pseudomonas aeruginosa infection in Catfish

    PubMed Central

    2013-01-01

    Background The bacteriophage therapy is an effective antimicrobial approach with potentially important applications in medicine and biotechnology which can be seen as an additional string in the bow. Emerging drug resistant bacteria in aquaculture industry due to unrestricted use of antibiotics warrants more sustainable and environmental friendly strategies for controlling fish infections. The isolated bacteria from fish lesions was characterised based on isolation on selective and differential medium like Pseudomonas agar, gram staining, biochemical tests and 16SrRNA sequencing. The metallo-beta-lactamase (MBL) producing bacterial isolate was evaluated using Imipenem - Ethylenediaminetetraacetic acid (EDTA) disk method. The specific bacteriophage was isolated and concentrated using coal bed developed in our lab at CSIR-NEERI. The isolated and enriched bacteriophage was characterised by nucleotide sequencing and electron microscopy. The phage therapy was applied for treating ulcerative lesion in fish. Results The pathogenic bacterium responsible for causing ulcerative lesions in catfish species (Clarias gariepinus) was identified as Pseudomonas aeruginosa. One out of twenty P. aeruginosa isolate showing multi drug resistance (MDR) was incidentally found to be MBL producing as determined by Imipenem-EDTA disk method. The phage therapy effectively cured the ulcerative lesions of the infected fish in 8–10 days of treatment, with a sevenfold reduction of the lesion with untreated infection control. Conclusion Bacteriophage therapy can have potential applications soon as an alternative or as a complement to antibiotic treatment in the aquaculture. We present bacteriophage therapy as a treatment method for controlling MDR P. aeruginosa infection in C. gariepinus. To the best of our knowledge this is a first report of application of phage therapy against MBL producing P. aeruginosa isolated from aquatic ecosystem. PMID:24369750

  8. Enzymatic characterisation of clinical isolates of Cryptococcus neoformans, Cryptococcus gattii and other environmental Cryptococcus spp.

    PubMed

    Chan, M Y; Tay, S T

    2010-01-01

    This study compared the enzymatic activity of clinical isolates of Cryptococcus neoformans, Cryptococcus gattii, environmental isolates of C. neoformans and non-neoformans Cryptococcus. Most of the cryptococcal isolates investigated in this study exhibited proteinase and phospholipase activities. Laccase activity was detected from all the C. neoformans and C. gattii isolates, but not from the non-neoformans Cryptococcus isolates. There was no significant difference in the proteinase, phospholipase and laccase activities of C. neoformans and C. gattii. However, significant difference in the enzymatic activities of beta-glucuronidase, alpha-glucosidase, beta-glucosidase and N-acetyl-beta-glucosaminidase between C. neoformans and C. gattii isolates was observed in this study. Environmental isolates of C. neoformans exhibited similar enzymatic profiles as the clinical isolates of C. neoformans, except for lower proteinase and laccase activities.

  9. Ribotyping of Pseudomonas aeruginosa: discriminatory power and usefulness as a tool for epidemiological studies.

    PubMed Central

    Blanc, D S; Siegrist, H H; Sahli, R; Francioli, P

    1993-01-01

    Restriction fragment length polymorphism of ribosomal DNA regions (ribotyping) of Pseudomonas aeruginosa was evaluated as a tool for epidemiological purposes. Fifty-five epidemiologically unrelated isolates from three geographic areas of Switzerland and 11 isolates obtained during an outbreak of P. aeruginosa infections in a burn unit were typed by this method. Typeability and reproducibility of the method reached 100%. With four selected restriction enzymes (BamHI, ClaI, EcoRI, and PstI), the 55 unrelated isolates could be classified into 33 ribotypes. To assess the value of this method for the interpretation of epidemiological data, we calculated an index of discrimination (ID) which takes into consideration both the number of types defined by the typing method and their relative frequencies. Our ribotyping system obtained a high ID of 0.958 with only four restriction enzymes, comparing well with other different typing schemes for which ID values could be calculated from published data. All clinical isolates of the outbreak belonged to the same ribotype, whereas environmental isolates, initially thought to be the source of the epidemic, belonged to a different ribotype. Thus, the typeability, reproducibility, and discriminatory power of our method as well as its value established in an epidemiological investigation were found to be appropriate for further epidemiological studies of P. aeruginosa. Images PMID:8093252

  10. Quorum quenching activity in cell-free lysate of endophytic bacteria isolated from Pterocarpus santalinus Linn., and its effect on quorum sensing regulated biofilm in Pseudomonas aeruginosa PAO1.

    PubMed

    Rajesh, P S; Ravishankar Rai, V

    2014-01-01

    Quorum sensing mechanism allows the microorganisms to resist the antibiotic treatment by forming biofilms. Quorum quenching is one of the mechanisms to control the development of drug resistance in microbes. Endophyte bacteria are beneficial to plant growth as they support the immune system against the pathogen attack. The endophytic bacteria present in Pterocarpus santalinus were screened for the presence of N-acyl homoserine lactones (AHLs) degrading bacteria using biosensor strains and further confirmed by quantifying the violacein production. Cell-free lysate of endophytic bacteria, Bacillus firmus PT18 and Enterobacter asburiae PT39 exhibited potent AHL degrading ability by inhibiting about 80% violacein production in biosensor strain. Furthermore, when the cell-free lysate was applied to Pseudomonas aeruginosa PAO1 and PAO1-JP2 biofilm it resulted in significant (p<0.01) inhibition of biofilm formation. The biofilm inhibition was confirmed by visualization of biofilm slides under fluorescence microscopy, which showed decrease in total biomass formation in treated slides. Isolation and amplification of the gene (aiiA) indicated that the presence of AHL lactonase in cell-free lysate and sequence alignment indicated that AiiA contains a "HXHXDH" zinc-binding motif that is being conserved in several groups of metallohydrolases. Therefore, the study shows the potential of AHLs degradation by AHL lactonase present in cell-free lysate of isolated endophytic bacteria and inhibition of quorum sensing regulated biofilm formation in P. aeruginosa PAO1.

  11. A simple test for the detection of KPC and metallo-β-lactamase carbapenemase-producing Pseudomonas aeruginosa isolates with the use of meropenem disks supplemented with aminophenylboronic acid, dipicolinic acid and cloxacillin.

    PubMed

    Pasteran, F; Veliz, O; Faccone, D; Guerriero, L; Rapoport, M; Mendez, T; Corso, A

    2011-09-01

    We evaluated the ability of the combination disk test (CDT) and the Modified Hodge Test (MHT) to discriminate between various carbapenemase-producing Pseudomonas aeruginosa isolates (KPC, n = 36; metallo-β-lactamase (MBL), n = 38) and carbapenemase non-producers (n = 75). For the CDT, the optimal inhibitor concentrations and cut-off values were: 600 μg of 3-aminophenylboronic acid (APB) per disk (an increment of ≥4 mm), 1000 μg of dipicolinic acid (DPA) per disk (an increment of ≥5 mm) and 3000 μg of cloxacillin per disk (an increment of ≥3 mm). APB had excellent sensitivity (97%) and specificity (97%) for the detection of KPC enzymes. DPA detected MBL enzymes with a sensitivity and specificity of 97% and 81%, respectively. The MHT resulted in a low sensitivity (78%) and specificity (57%). The CDT could be very useful in daily practice to provide fast and reliable detection of KPC and MBL carbapenemases among P. aeruginosa isolates.

  12. Loss of Social Behaviours in Populations of Pseudomonas aeruginosa Infecting Lungs of Patients with Cystic Fibrosis

    PubMed Central

    Jiricny, Natalie; Molin, Søren; Foster, Kevin; Diggle, Stephen P.; Scanlan, Pauline D.; Ghoul, Melanie; Johansen, Helle Krogh; Santorelli, Lorenzo A.; Popat, Roman; West, Stuart A.; Griffin, Ashleigh S.

    2014-01-01

    Pseudomonas aeruginosa, is an opportunistic, bacterial pathogen causing persistent and frequently fatal infections of the lung in patients with cystic fibrosis. Isolates from chronic infections differ from laboratory and environmental strains in a range of traits and this is widely interpreted as the result of adaptation to the lung environment. Typically, chronic strains carry mutations in global regulation factors that could effect reduced expression of social traits, raising the possibility that competitive dynamics between cooperative and selfish, cheating strains could also drive changes in P. aeruginosa infections. We compared the expression of cooperative traits - biofilm formation, secretion of exo-products and quorum sensing (QS) - in P. aeruginosa isolates that were estimated to have spent different lengths of time in the lung based on clinical information. All three exo-products involved in nutrient acquisition were produced in significantly smaller quantities with increased duration of infection, and patterns across four QS signal molecules were consistent with accumulation over time of mutations in lasR, which are known to disrupt the ability of cells to respond to QS signal. Pyocyanin production, and the proportion of cells in biofilm relative to motile, free-living cells in liquid culture, did not change. Overall, our results confirm that the loss of social behaviour is a consistent trend with time spent in the lung and suggest that social dynamics are potentially relevant to understanding the behaviour of P. aeruginosa in lung infections. PMID:24454693

  13. Loss of social behaviours in populations of Pseudomonas aeruginosa infecting lungs of patients with cystic fibrosis.

    PubMed

    Jiricny, Natalie; Molin, Søren; Foster, Kevin; Diggle, Stephen P; Scanlan, Pauline D; Ghoul, Melanie; Johansen, Helle Krogh; Santorelli, Lorenzo A; Popat, Roman; West, Stuart A; Griffin, Ashleigh S

    2014-01-01

    Pseudomonas aeruginosa, is an opportunistic, bacterial pathogen causing persistent and frequently fatal infections of the lung in patients with cystic fibrosis. Isolates from chronic infections differ from laboratory and environmental strains in a range of traits and this is widely interpreted as the result of adaptation to the lung environment. Typically, chronic strains carry mutations in global regulation factors that could effect reduced expression of social traits, raising the possibility that competitive dynamics between cooperative and selfish, cheating strains could also drive changes in P. aeruginosa infections. We compared the expression of cooperative traits - biofilm formation, secretion of exo-products and quorum sensing (QS) - in P. aeruginosa isolates that were estimated to have spent different lengths of time in the lung based on clinical information. All three exo-products involved in nutrient acquisition were produced in significantly smaller quantities with increased duration of infection, and patterns across four QS signal molecules were consistent with accumulation over time of mutations in lasR, which are known to disrupt the ability of cells to respond to QS signal. Pyocyanin production, and the proportion of cells in biofilm relative to motile, free-living cells in liquid culture, did not change. Overall, our results confirm that the loss of social behaviour is a consistent trend with time spent in the lung and suggest that social dynamics are potentially relevant to understanding the behaviour of P. aeruginosa in lung infections.

  14. Primary isolation of Shiga toxigenic Escherichia coli from environmental sources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since the time of the first microbe hunters, primary culture and isolation of bacteria has been a foundation of microbiology. Like other microbial methods, bacterial culture and isolation methodologies continue to develop. Although fundamental concepts like selection and enrichment are as relevant t...

  15. Isolation and genotyping of free-living environmental isolates of Acanthamoeba spp. from bromeliads in Southern Brazil.

    PubMed

    Landell, Melissa Fontes; Salton, Juliana; Caumo, Karin; Broetto, Leonardo; Rott, Marilise B

    2013-07-01

    Species of Acanthamoeba are frequently isolated from distinct environmental sources such as water, soil, dust and air. They are responsible to cause infections and disease in humans and animals. In addition, Acanthamoeba sp. are considered an important reservoir of bacteria, virus and fungi, which act as "Trojan horses" to protect these microorganisms of harsh environmental conditions. In this study, nine Acanthamoeba isolates from bromeliads phylloplane were identified based on the morphology of cyst and trophozoite forms. The genotype level was accessed by the sequence analysis of Acanthamoeba small-subunit rRNA gene. Genotypic characterization grouped five isolates in the genotype T2/T6, three in the T4 genotype and one in the genotype T16. The results obtained indicate that the genotype T2/T6 is common on phylloplane. To predict the pathogenic potential of the Acanthamoeba isolates, thermo and osmotolerance assays were employed, although all isolates were capable of surviving at temperatures of 37°C, other tests will be conducted in the future to determine the potential pathogenic of the isolates. Altogether, our results revealed the importance of the presence of Acanthamoeba associated with bromeliads in Rio Grande do Sul, Brazil, and the necessity for further studies to determine the environmental distribution and the role of these species.

  16. In Vitro Activity of Fusidic Acid (CEM-102, Sodium Fusidate) against Staphylococcus aureus Isolates from Cystic Fibrosis Patients and Its Effect on the Activities of Tobramycin and Amikacin against Pseudomonas aeruginosa and Burkholderia cepacia▿

    PubMed Central

    McGhee, Pamela; Clark, Catherine; Credito, Kim; Beachel, Linda; Pankuch, Glenn A.; Appelbaum, Peter C.; Kosowska-Shick, Klaudia

    2011-01-01

    We tested the MICs of fusidic acid (CEM-102) plus other agents against 40 methicillin-resistant Staphylococcus aureus (MRSA) isolates from cystic fibrosis patients and the activities of fusidic acid with or without tobramycin or amikacin against Pseudomonas aeruginosa, MRSA, and Burkholderia cepacia isolates from cystic fibrosis patients in a 24-h time-kill study. Fusidic acid was potent (MICs, 0.125 to 0.5 μg/ml; a single 500-mg dose of fusidic acid at 8 h averaged 8 to 12. 5 μg/ml with 91 to 97% protein binding) against all MRSA strains. No antagonism was observed; synergy occurred for one MRSA strain treated with fusidic acid plus tobramycin. PMID:21343445

  17. Osteomyelitis due to multiple carbapenemase-producing Gram-negative bacteria: The first case report of a GES-13-producing Pseudomonas aeruginosa isolate in Canada.

    PubMed

    Sepehri, Shadi; Poliquin, Guillaume; Alfattoh, Nora; Boyd, David; Mulvey, Michael; Denisuik, Andrew; Fanella, Sergio; Karlowsky, James; Walkty, Andrew

    2014-07-01

    A case of osteomyelitis in an infant following a burn injury sustained in Pakistan caused by a GES-13-producing Pseudomonas aeruginosa (the first reported in Canada) and an OXA-48 producing Klebsiella pneumoniae is described. The present case serves to highlight the importance of international travel as a risk factor for infection with carbapenemase-producing bacteria and the challenges in the laboratory detection of these organisms.

  18. Pseudomonas aeruginosa adaptation to lungs of cystic fibrosis patients leads to lowered resistance to phage and protist enemies.

    PubMed

    Friman, Ville-Petri; Ghoul, Melanie; Molin, Søren; Johansen, Helle Krogh; Buckling, Angus

    2013-01-01

    Pathogenic life styles can lead to highly specialized interactions with host species, potentially resulting in fitness trade-offs in other ecological contexts. Here we studied how adaptation of the environmentally transmitted bacterial pathogen, Pseudomonas aeruginosa, to cystic fibrosis (CF) patients affects its survival in the presence of natural phage (14/1, ΦKZ, PNM and PT7) and protist (Tetrahymena thermophila and Acanthamoebae polyphaga) enemies. We found that most of the bacteria isolated from relatively recently intermittently colonised patients (1-25 months), were innately phage-resistant and highly toxic for protists. In contrast, bacteria isolated from long time chronically infected patients (2-23 years), were less efficient in both resisting phages and killing protists. Moreover, chronic isolates showed reduced killing of wax moth larvae (Galleria mellonella) probably due to weaker in vitro growth and protease expression. These results suggest that P. aeruginosa long-term adaptation to CF-lungs could trade off with its survival in aquatic environmental reservoirs in the presence of microbial enemies, while lowered virulence could reduce pathogen opportunities to infect insect vectors; factors that are both likely to result in poorer environmental transmission. From an applied perspective, phage therapy could be useful against chronic P. aeruginosa lung infections that are often characterized by multidrug resistance: chronic isolates were least resistant to phages and their poor growth will likely slow down the emergence of beneficial resistance mutations.

  19. Isolation and characterization of chlorpyrifos degrading soil bacteria of environmental and agronomic significance.

    PubMed

    Bhatia, Divya; Malik, Deepak Kumar

    2013-04-01

    Chlorpyrifos is being used globally as an agriculture based pesticide. Microbial degrada tion of chlorpyrifos pesticide is of particular interest because of high mammalian toxicity. Six bacterial cultures were isolated from chlorpyrifos contaminated soil by using enrich- ment technique. All the isolates showed good growth in basal salt medium containing chlorpyrifos and suggested their ability to utilize chlorpyrifos as sole carbon and energy source. All the six bacterial cultures were examined for various plant growth promoting properties, out of six only one bacteirial culture Pseudomonas aeruginosa DKC2 was found to be positive for various plant growth promoting activities (phosphate solubiliza- tion, protease activity, IAA production and antagonistic properties against plant patho- genic fungi). The resting cell study confirmed that the bacterial strain DKC2 degrade chlorpyrifos by 71 % within 2 days. Isolated bacterial culture can be used successfully for the removal of chlorpyrifos from contaminated soil along with plant growth promotion, but further research is required before commercial utilization of this isolate in removing chlorpyrifos from contaminated soil.

  20. Accurate mass analysis of N-acyl-homoserine-lactones and cognate lactone-opened compounds in bacterial isolates of Pseudomonas aeruginosa PAO1 by LC-ESI-LTQ-FTICR-MS.

    PubMed

    Cataldi, Tommaso R I; Bianco, Giuliana; Abate, Salvatore

    2009-02-01

    N-acyl-homoserine-lactones (AHSLs) are widely conserved signal molecules present in quorum sensing systems of Gram-negative bacteria such as Pseudomonas aeruginosa. We present here the results obtained with a hybrid linear trap/Fourier transform ion cyclotron resonance (LTQ-FTICR) mass spectrometer used to investigate the occurrence of AHSLs and cognate N-acyl-homoserines (AHSs) in bacterial isolates of P. aeruginosa (strain PAO1). Two hydrolysed AHSs were found in significant amounts, most likely formed through the lactone opening of N-3-oxo-decanoyl-L-homoserine-lactone (3OC10-HSL) and N-3-oxo-dodecanoyl-L-homoserine-lactone (3OC12-HSL). Structure elucidation of these ring-opened molecules, i.e. N-3-oxo-decanoyl-L-homoserine (3OC10-HS), and N-3-oxo-dodecanoyl-L-homoserine (3OC12-HS), which are not detected by bacterial biosensors, was performed by high-resolution and accurate mass measurements upon liquid chromatography (LC) and confirmed by tandem MS in the LTQ analyser. Assignment of chemical formula, with mass spectra in the form of [M+H]+, was significantly expedited by extracted ion chromatograms (XICs) because the number of potentially plausible formulae for each protonated signalling molecule was considerably reduced a priori by the LC behaviour, the high mass measurement accuracy available in FTICR mass spectra and the isotopic patterns. At least two concentration levels were observed in spent culture supernatants of P. aeruginosa: compounds at a relatively high content (5-15 microM) that is C4-HSL, 3OC10-HS, and 3OC12-HS and those occurring at a lower content (<0.2 microM) that is C6-HSL and C8-HSL. The implications of this work extend to a great variety of Gram-negative bacteria.

  1. Molecular identification, antifungal susceptibility profile, and biofilm formation of clinical and environmental Rhodotorula species isolates.

    PubMed

    Nunes, Jorge Meneses; Bizerra, Fernando César; Ferreira, Renata Carmona E; Colombo, Arnaldo Lopes

    2013-01-01

    Rhodotorula species are emergent fungal pathogens capable of causing invasive infections, primarily fungemia. They are particularly problematic in immunosuppressed patients when using a central venous catheter. In this study, we evaluated the species distribution of 51 clinical and 8 environmental Rhodotorula species isolates using the ID32C system and internal transcribed spacer (ITS) sequencing. Antifungal susceptibility testing and biofilm formation capability using a crystal violet staining assay were performed. Using ITS sequencing as the gold standard, the clinical isolates were identified as follows: 44 R. mucilaginosa isolates, 2 R. glutinis isolates, 2 R. minuta isolates, 2 R. dairenensis isolates, and 1 Rhodosporidium fluviale isolate. The environmental isolates included 7 R. mucilaginosa isolates and 1 R. slooffiae isolate. Using the ID32C system, along with a nitrate assimilation test, only 90.3% of the isolates tested were correctly identified. In the biofilm formation assay, R. mucilaginosa and R. minuta exhibited greater biofilm formation ability compared to the other Rhodotorula species; the clinical isolates of R. mucilaginosa showed greater biofilm formation compared to the environmental isolates (P = 0.04). Amphotericin B showed good in vitro activity (MIC ≤ 1 μg/ml) against planktonic cells, whereas voriconazole and posaconazole showed poor activity (MIC(50)/MIC(90), 2/4 μg/ml). Caspofungin and fluconazole MICs were consistently high for all isolates tested (≥64 μg/ml and ≥ 4 μg/ml, respectively). In this study, we emphasized the importance of molecular methods to correctly identify Rhodotorula species isolates and non-R. mucilaginosa species in particular. The antifungal susceptibility profile reinforces amphotericin B as the antifungal drug of choice for the treatment of Rhodotorula infections. To our knowledge, this is the first study evaluating putative differences in the ability of biofilm formation among different Rhodotorula

  2. Molecular Identification, Antifungal Susceptibility Profile, and Biofilm Formation of Clinical and Environmental Rhodotorula Species Isolates

    PubMed Central

    Nunes, Jorge Meneses; Bizerra, Fernando César; Ferreira, Renata Carmona e

    2013-01-01

    Rhodotorula species are emergent fungal pathogens capable of causing invasive infections, primarily fungemia. They are particularly problematic in immunosuppressed patients when using a central venous catheter. In this study, we evaluated the species distribution of 51 clinical and 8 environmental Rhodotorula species isolates using the ID32C system and internal transcribed spacer (ITS) sequencing. Antifungal susceptibility testing and biofilm formation capability using a crystal violet staining assay were performed. Using ITS sequencing as the gold standard, the clinical isolates were identified as follows: 44 R. mucilaginosa isolates, 2 R. glutinis isolates, 2 R. minuta isolates, 2 R. dairenensis isolates, and 1 Rhodosporidium fluviale isolate. The environmental isolates included 7 R. mucilaginosa isolates and 1 R. slooffiae isolate. Using the ID32C system, along with a nitrate assimilation test, only 90.3% of the isolates tested were correctly identified. In the biofilm formation assay, R. mucilaginosa and R. minuta exhibited greater biofilm formation ability compared to the other Rhodotorula species; the clinical isolates of R. mucilaginosa showed greater biofilm formation compared to the environmental isolates (P = 0.04). Amphotericin B showed good in vitro activity (MIC ≤ 1 μg/ml) against planktonic cells, whereas voriconazole and posaconazole showed poor activity (MIC50/MIC90, 2/4 μg/ml). Caspofungin and fluconazole MICs were consistently high for all isolates tested (≥64 μg/ml and ≥ 4 μg/ml, respectively). In this study, we emphasized the importance of molecular methods to correctly identify Rhodotorula species isolates and non-R. mucilaginosa species in particular. The antifungal susceptibility profile reinforces amphotericin B as the antifungal drug of choice for the treatment of Rhodotorula infections. To our knowledge, this is the first study evaluating putative differences in the ability of biofilm formation among different Rhodotorula species

  3. Genotypes of Clinical and Environmental Isolates of Cryptococcus neoformans and Cryptococcus gattii in Korea

    PubMed Central

    Park, So Hae; Choi, Seok Cheol; Lee, Kyung Won; Kim, Mi-Na

    2015-01-01

    Multilocus sequence typing analysis was applied to determine the genotypes of 147 (137 clinical and 10 environmental) Cryptococcus neoformans and three clinical Cryptococcus gattii isolates from 1993 to 2014 in Korea. Among the 137 clinical isolates of C. neoformans, the most prevalent genotype was ST5 (n = 131), followed by ST31 (n = 5) and ST127 (n = 1). Three C. gattii strains were identified as ST57, ST7, and ST113. All environmental isolates were identified as C. neoformans with two genotypes, ST5 (n = 7) and ST31 (n = 3). Our results show that C. neoformans isolates in Korea are genetically homogeneous, and represent a close genetic relationship between clinical and environmental isolates. PMID:26539057

  4. DIFFERENTIAL EFFECTS OF OYSTER (CRASSOSTREA VIRGINICA) DEFENSES ON CLINICAL AND ENVIRONMENTAL ISOLATES OF VIBRIO PARAHEMOLYTICUS

    EPA Science Inventory

    Three clinical (2030, 2062, and 2107) and three environmental (1094, 1163, and ATCC 17802) isolates of Vibrio parahaemolyticus were exposed to hemocytes and plasma collected from oysters (Crassostrea virginica) to determine their susceptibility to putative oyster defenses. Clinic...

  5. OCCURRENCE OF HIGH-LEVEL AMINOGLYCOSIDE RESISTANCE IN ENVIRONMENTAL ISOLATES OF ENTEROCOCCI

    EPA Science Inventory

    High-level resistance fo aminoglycosides was observed in environmental isolates of enterococci. Various aquatic habitats, including agricultural runoff, creeks, rivers, wastewater, and wells, were analyzed. Strains of Enterococcus faecalis, e.faecium, E. gallinarum, and other Ent...

  6. Detection of piluslike structures on clinical and environmental isolates of Vibrio vulnificus.

    PubMed Central

    Gander, R M; LaRocco, M T

    1989-01-01

    Twenty clinical isolates of Vibrio vulnificus were compared with 10 environmental strains by using electron microscopy and agglutination assays with human erythrocytes, guinea pig erythrocytes, and Saccharomyces cerevisiae. In addition, the isolates were tested for ability to adhere to the human epithelial cell lines HEp-2 and A549. When examined by electron microscopy, 16 (80%) of the 20 clinical isolates demonstrated the presence of piluslike structures; the composition of the bacterial populations ranged from 0 to 68% piliated cells. In contrast, only 3 (30%) of the 10 environmental isolates were piliated, with a range from 0 to 16% piliated cells. A significant association between the presence of piliated cells and the isolate source was found (P less than 0.05). None of the 30 strains agglutinated erythrocytes or yeast cells. V. vulnificus adherence results obtained with HEp-2 cells showed 10 (50%) of 20 clinical isolates and 0 (0%) of 10 environmental isolates with averages of greater than 10 adherent bacteria per cell, demonstrating a correlation between attachment and the isolate source (P less than 0.05). Selected strains were tested to determine whether methyl alpha-D-mannopyranoside, fructose, or alpha-L-(-)-fucose would inhibit bacterial adherence to HEp-2 cells. Multiple patterns of adherence inhibition were observed. Adherence to A549 cells showed 8 (40%) of 20 clinical isolates and 0 (0%) of 10 environmental strains with averages of greater than 10 adherent bacteria per cell. A statistical association between attachment and the isolate source was demonstrated (P less than 0.05). These data suggest that the presence of piluslike structures and the ability to adhere to human epithelial cell lines may be more closely associated with V. vulnificus isolates from clinical specimens than with environmental strains. Images PMID:2568368

  7. Molecular typing and antifungal susceptibility of clinical and environmental Cryptococcus neoformans species complex isolates in Goiania, Brazil.

    PubMed

    Souza, L K H; Souza Junior, A H; Costa, C R; Faganello, J; Vainstein, M H; Chagas, A L B; Souza, A C M; Silva, M R R

    2010-01-01

    A total of 124 Cryptococcus isolates, including 84 clinical strains obtained from cerebrospinal fluid from AIDS patients and 40 environmental isolates from pigeon excreta and from Eucalyptus trees, were studied. The varieties, serotypes, phospholipase activity and molecular profile of these isolates were determined. Cryptococcus neoformans var. grubii serotype A was identified in 120 isolates and Cryptococcus gattii serotype B in four isolates. The clinical isolates showed higher phospholipase activity than environmental isolates. Similar patterns of in vitro susceptibility to amphotericin B, fluconazole, itraconazole and voriconazole and no resistance were found for all isolates. Molecular type VNI (C. neoformans var. grubii) was recovered in 80 clinical and 40 environmental isolates while the type VGIII (C. gattii) was found in four clinical isolates. This study demonstrated for the first time the molecular types of clinical and environmental Cryptococcus isolates in the midwest Brazil region.

  8. First detection in Europe of the metallo-β-lactamase IMP-15 in clinical strains of Pseudomonas putida and Pseudomonas aeruginosa.

    PubMed

    Gilarranz, R; Juan, C; Castillo-Vera, J; Chamizo, F J; Artiles, F; Álamo, I; Oliver, A

    2013-09-01

    In a prospective study (2009-2011) in healthcare institutions from the Canary Islands (Spain), 6 out of 298 carbapenem non-susceptible Pseudomonas aeruginosa isolates produced a metallo-β-lactamase: four IMP-15, two VIM-2 (including one IMP-15-positive isolate) and one VIM-1. Multilocus sequence typing identified the single VIM-1-producing isolate as clone ST111 and two IMP-15-producing isolates as ST606, but, strikingly, bacterial re-identification revealed that the other three isolates (producing IMP-15 and/or VIM-2) were actually Pseudomonas putida. Further retrospective analysis revealed a very high prevalence (close to 50%) of carbapenem resistance in this environmental species. Hence, we report the simultaneous emergence in hospitals on the Canary Islands of P. putida and P. aeruginosa strains producing IMP-15, a metallo-β-lactamase not previously detected in Europe, and suggest an underestimated role of P. putida as a nosocomial reservoir of worrying transferable resistance determinants.

  9. Strain- and Substrate-Dependent Redox Mediator and Electricity Production by Pseudomonas aeruginosa

    PubMed Central

    Bosire, Erick M.; Blank, Lars M.

    2016-01-01

    ABSTRACT Pseudomonas aeruginosa is an important, thriving member of microbial communities of microbial bioelectrochemical systems (BES) through the production of versatile phenazine redox mediators. Pure culture experiments with a model strain revealed synergistic interactions of P. aeruginosa with fermenting microorganisms whereby the synergism was mediated through the shared fermentation product 2,3-butanediol. Our work here shows that the behavior and efficiency of P. aeruginosa in mediated current production is strongly dependent on the strain of P. aeruginosa. We compared levels of phenazine production by the previously investigated model strain P. aeruginosa PA14, the alternative model strain P. aeruginosa PAO1, and the BES isolate Pseudomonas sp. strain KRP1 with glucose and the fermentation products 2,3-butanediol and ethanol as carbon substrates. We found significant differences in substrate-dependent phenazine production and resulting anodic current generation for the three strains, with the BES isolate KRP1 being overall the best current producer and showing the highest electrochemical activity with glucose as a substrate (19 μA cm−2 with ∼150 μg ml−1 phenazine carboxylic acid as a redox mediator). Surprisingly, P. aeruginosa PAO1 showed very low phenazine production and electrochemical activity under all tested conditions. IMPORTANCE Microbial fuel cells and other microbial bioelectrochemical systems hold great promise for environmental technologies such as wastewater treatment and bioremediation. While there is much emphasis on the development of materials and devices to realize such systems, the investigation and a deeper understanding of the underlying microbiology and ecology are lagging behind. Physiological investigations focus on microorganisms exhibiting direct electron transfer in pure culture systems. Meanwhile, mediated electron transfer with natural redox compounds produced by, for example, Pseudomonas aeruginosa might enable an

  10. Draft Genome Sequence of an Environmental trh+ Vibrio parahaemolyticus K23 Strain Isolated from Kerala, India

    PubMed Central

    Prabhakaran, Divya Meparambu; Chowdhury, Goutam; Pazhani, Gururaja Perumal; Ramamurthy, Thandavarayan

    2016-01-01

    Vibrio parahaemolyticus is the leading cause of seafood-related gastroenteritis. Here, we report the draft genome sequence of a trh+ strain, V. parahaemolyticus K23, isolated from seafood. The sequence will be useful for comparative analysis between environmental and clinical isolates of V. parahaemolyticus. PMID:27081143

  11. Shared Mycobacterium avium genotypes observed among unlinked clinical and environmental isolates*

    EPA Science Inventory

    Our understanding of the sources of Mycobacterium avium infection is partially based on genotypic matching of pathogen isolates from cases and environmental sources. These approaches assume that genotypic identity is rare in isolates from unlinked cases or sources. To test this a...

  12. Shared Mycobacterium avium genotypes observed among unlinked clinical and environmental isolates

    EPA Science Inventory

    Our understanding of the sources of Mycobacterium avium infection is partially based on genotypic matching of pathogen isolates from cases and environmental sources. These approaches assume that genotypic identity is rare in isolates from unlinked cases or sources. To test this, ...

  13. Aeromonas hydrophila: variability in biochemical characteristics of environmental isolates.

    PubMed

    Okpokwasili, G C

    1991-01-01

    A total of 161 strains, including 144 aeromonads, of which 100 had been isolated from water and sediment samples from the Chesapeake Bay, five clinical and 33 Anacostia River isolates of Aeromonas hydrophila, six Aeromonas sobria, and ten reference cultures were examined in a numerical taxonomy study in which each of the strains were examined for 56 unit characters. Similarity between strains was computed using the simple matching (SSM) and Jaccard (SJ) coefficients. The strains were clustered by unweighted average linkage and single linkage algorithms. Results of all analyses yielded similar clusterings of strains. Of the 161 strains included in the study, 148 were recovered in seven major clusters. A large cluster of Aeromonas hydrophila yielded two sub-clusters. From the results of the taxonomic analysis it is concluded that several biovars of Aeromonas hydrophila can be isolated from the aquatic environment, but geographical or site specific distribution of the biovars could not be detected.

  14. Isolation and molecular characterization of Salmonella enterica serovar Javiana from food, environmental and clinical samples.

    PubMed

    Mezal, Ezat H; Stefanova, Rossina; Khan, Ashraf A

    2013-06-03

    A total of 50 Salmonella enterica serovar Javiana isolates, isolated from food, environmental and clinical samples, were analyzed for antibiotic resistance, presence of virulence genes, plasmids and plasmid replicon types. To assess the genetic diversity, pulsed-field gel electrophoresis (PFGE) fingerprinting and plasmid profiles were performed. All of the isolates were sensitive to chloramphenicol, nalidixic acid, and sulfisoxazole, and four isolates showed intermediate resistance to gentamicin or kanamycin. Eleven isolates, including representatives from each of the source types, were resistant to ampicillin. Four isolates from either clinical or environmental sources were resistant to tetracycline, while an additional 20 isolates showed intermediate resistance to this drug. Fourteen isolates, primarily from food sources, showed intermediate resistance to streptomycin. The S. Javiana isolates were screened by PCR for 17 virulence genes (spvB, spiA, pagC, msgA, invA, sipB, prgH, spaN, orgA, tolC, iroN, sitC, IpfC, sifA, sopB, cdtB, and pefA). All isolates were positive for nine to fourteen of these genes, but none were positive for pefA, spvB and lpfC, which are typically present on the Salmonella virulence plasmid. Seven of the virulence genes including cdtB were found in all 50 isolates, suggesting that S. Javiana from food and environmental sources had virulence similar to clinical isolates. Four clinical isolates and two food isolates carried one or more plasmids of approximately 30, 38, and 58 kb, with the 58 kb plasmids belonging to incompatibility group IncFIIA. Two clinical isolates carried IncI1 type mega plasmid (80 kb), and one clinical isolate carried plasmids of 4.5 and 7 kb. The PFGE profiles resulted 34 patterns in five clusters at a 90% similarity threshold. Our results indicate that S. Javiana isolates have a diverse clonal population among the clinical, food and environmental samples and this serotype possesses several virulent genes and plasmids

  15. Presence of high-risk clones of OXA-23-producing Acinetobacter baumannii (ST79) and SPM-1-producing Pseudomonas aeruginosa (ST277) in environmental water samples in Brazil.

    PubMed

    Turano, Helena; Gomes, Fernando; Medeiros, Micheli; Oliveira, Silvane; Fontes, Lívia C; Sato, Maria I Z; Lincopan, Nilton

    2016-09-01

    This study reports the presence of hospital-associated high-risk lineages of OXA-23-producing ST79 Acinetobacter baumannii and SPM-1-producing ST277 Pseudomonas aeruginosa in urban rivers in Brazil. These findings indicate that urban rivers can act as reservoirs of clinically important multidrug-resistant bacteria, which constitute a potential risk to human and animal health.

  16. Environmental optimization for production of 7, 10-dihydroxy-8(E)-octadecenoic acid from olive oil by Pseudomonas aeruginosa PR3

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microbial conversions of free unsaturated fatty acids often generate novel hydroxy fatty acids (HFA), which are known to have special properties such as higher viscosity and reactivity. Among microbial strains known to produce HFAs, Pseudomonas aeruginosa PR3 has been well studied to produce 7,10-d...

  17. Homogeneity of Danish environmental and clinical isolates of Shewanella algae.

    PubMed

    Vogel, B F; Holt, H M; Gerner-Smidt, P; Bundvad, A; Sogaard, P; Gram, L

    2000-01-01

    Danish isolates of Shewanella algae constituted by whole-cell protein profiling a very homogeneous group, and no clear distinction was seen between strains from the marine environment and strains of clinical origin. Although variation between all strains was observed by ribotyping and random amplified polymorphic DNA analysis, no clonal relationship between infective strains was found. From several patients, clonally identical strains of S. algae were reisolated up to 8 months after the primary isolation, indicating that the same strain may be able to maintain the infection.

  18. Genomic Features of Environmental and Clinical Vibrio parahaemolyticus Isolates Lacking Recognized Virulence Factors Are Dissimilar.

    PubMed

    Ronholm, J; Petronella, N; Chew Leung, C; Pightling, A W; Banerjee, S K

    2015-12-04

    Vibrio parahaemolyticus is a bacterial pathogen that can cause illness after the consumption or handling of contaminated seafood. The primary virulence factors associated with V. parahaemolyticus illness are thermostable direct hemolysin (TDH) and Tdh-related hemolysin (TRH). However, clinical strains lacking tdh and trh have recently been isolated, and these clinical isolates are poorly understood. To help understand the emergence of clinical tdh- and trh-negative isolates, a genomic approach was used to comprehensively compare 4 clinical tdh- and trh-negative isolates with 16 environmental tdh- and trh-negative isolates and 34 clinical isolates positive for tdh or trh, or both, with the objective of identifying genomic features that are unique to clinical tdh- and trh-negative isolates. The prevalence of pathogenicity islands (PAIs) common to clinical isolates was thoroughly examined in each of the clinical tdh- and trh-negative isolates. The tdh PAI was not present in any clinical or environmental tdh- and trh-negative isolates. The trh PAI was not present in any environmental isolates; however, in clinical tdh- and trh-negative isolate 10-4238, the majority of the trh PAI including a partial trh1 gene was present, which resulted in reclassification of this isolate as a tdh-negative and trh-positive isolate. In the other clinical tdh- and trh-negative isolates, neither the trh gene nor the trh PAI was present. We identified 862 genes in clinical tdh- and trh-negative isolates but not in environmental tdh- and trh-negative isolates. Many of these genes are highly homologous to genes found in common enteric bacteria and included genes encoding a number of chemotaxis proteins and a novel putative type VI secretion system (T6SS) effector and immunity protein (T6SS1). The availability of genome sequences from clinical V. parahaemolyticus tdh- and trh-negative isolates and the comparative analysis may help provide an understanding of how this pathotype is able to

  19. Genomic Features of Environmental and Clinical Vibrio parahaemolyticus Isolates Lacking Recognized Virulence Factors Are Dissimilar

    PubMed Central

    Petronella, N.; Chew Leung, C.; Pightling, A. W.; Banerjee, S. K.

    2015-01-01

    Vibrio parahaemolyticus is a bacterial pathogen that can cause illness after the consumption or handling of contaminated seafood. The primary virulence factors associated with V. parahaemolyticus illness are thermostable direct hemolysin (TDH) and Tdh-related hemolysin (TRH). However, clinical strains lacking tdh and trh have recently been isolated, and these clinical isolates are poorly understood. To help understand the emergence of clinical tdh- and trh-negative isolates, a genomic approach was used to comprehensively compare 4 clinical tdh- and trh-negative isolates with 16 environmental tdh- and trh-negative isolates and 34 clinical isolates positive for tdh or trh, or both, with the objective of identifying genomic features that are unique to clinical tdh- and trh-negative isolates. The prevalence of pathogenicity islands (PAIs) common to clinical isolates was thoroughly examined in each of the clinical tdh- and trh-negative isolates. The tdh PAI was not present in any clinical or environmental tdh- and trh-negative isolates. The trh PAI was not present in any environmental isolates; however, in clinical tdh- and trh-negative isolate 10-4238, the majority of the trh PAI including a partial trh1 gene was present, which resulted in reclassification of this isolate as a tdh-negative and trh-positive isolate. In the other clinical tdh- and trh-negative isolates, neither the trh gene nor the trh PAI was present. We identified 862 genes in clinical tdh- and trh-negative isolates but not in environmental tdh- and trh-negative isolates. Many of these genes are highly homologous to genes found in common enteric bacteria and included genes encoding a number of chemotaxis proteins and a novel putative type VI secretion system (T6SS) effector and immunity protein (T6SS1). The availability of genome sequences from clinical V. parahaemolyticus tdh- and trh-negative isolates and the comparative analysis may help provide an understanding of how this pathotype is able to

  20. Imported PER-1 producing Pseudomonas aeruginosa, PER-1 producing Acinetobacter baumanii and VIM-2-producing Pseudomonas aeruginosa strains in Hungary

    PubMed Central

    Szabó, Dora; Szentandrássy, Julia; Juhász, Zsuzsa; Katona, Katalin; Nagy, Károly; Rókusz, László

    2008-01-01

    Introduction Pseudomonas aeruginosa and Acinetobacter baumanii are important nosocomial pathogens with wide intrinsic resistance. However, due to the dissemination of the acquired resistance mechanisms, such as extended-spectrum beta-lactamase (ESBL) and metallo beta-lactamase (MBL) production, multidrug resistant strains have been isolated more often. Case presentation We report a case of a Hungarian tourist, who was initially hospitalized in Egypt and later transferred to Hungary. On the day of admission PER-1-producing P. aeruginosa, PER-1 producing A. baumannii, SHV-5-producing Klebsiella pneumoniae and VIM-2-producing P. aeruginosa isolates were subcultured from the patient's samples in Hungary. Comparing the pulsed-field gel electrophoresis (PFGE) patterns of the P. aeruginosa strains from the patient to the P. aeruginosa strains occurring in this hospital, we can state that the PER-1-producing P. aeruginosa and VIM-2-producing P. aeruginosa had external origin. Conclusion This is the first report of PER-1-producing P. aeruginosa,and PER-1-producing A. baumanii strains in Hungary. This case highlights the importance of spreading of the beta-lactamase-mediated resistance mechanisms between countries and continents, showing the importance of careful screening and the isolation of patients arriving from a different country. PMID:18513394

  1. In vitro susceptibilities of clinical and environmental isolates of Cryptococcus neoformans to five antifungal drugs.

    PubMed Central

    Franzot, S P; Hamdan, J S

    1996-01-01

    A total of 53 Cryptococcus neoformans strains, including clinical and environmental Brazilian isolates, were tested for their susceptibilities to amphotericin B, 5-flucytosine, ketoconazole, fluconazole, and itraconazole. The tests were performed according to the National Committee of Clinical Laboratory Standards recommendations (document M27-P). In general, there was a remarkable homogeneity of results for all strains, and comparable MICs were found for environmental and clinical isolates. This paper represents the first contribution in which susceptibility data for Brazilian C. neoformans isolates are provided. PMID:8851624

  2. Developing an international Pseudomonas aeruginosa reference panel.

    PubMed

    De Soyza, Anthony; Hall, Amanda J; Mahenthiralingam, Eshwar; Drevinek, Pavel; Kaca, Wieslaw; Drulis-Kawa, Zuzanna; Stoitsova, Stoyanka R; Toth, Veronika; Coenye, Tom; Zlosnik, James E A; Burns, Jane L; Sá-Correia, Isabel; De Vos, Daniel; Pirnay, Jean-Paul; Kidd, Timothy J; Reid, David; Manos, Jim; Klockgether, Jens; Wiehlmann, Lutz; Tümmler, Burkhard; McClean, Siobhán; Winstanley, Craig

    2013-12-01

    Pseudomonas aeruginosa is a major opportunistic pathogen in cystic fibrosis (CF) patients and causes a wide range of infections among other susceptible populations. Its inherent resistance to many antimicrobials also makes it difficult to treat infections with this pathogen. Recent evidence has highlighted the diversity of this species, yet despite this, the majority of studies on virulence and pathogenesis focus on a small number of strains. There is a pressing need for a P. aeruginosa reference panel to harmonize and coordinate the collective efforts of the P. aeruginosa research community. We have collated a panel of 43 P. aeruginosa strains that reflects the organism's diversity. In addition to the commonly studied clones, this panel includes transmissible strains, sequential CF isolates, strains with specific virulence characteristics, and strains that represent serotype, genotype or geographic diversity. This focussed panel of P. aeruginosa isolates will help accelerate and consolidate the discovery of virulence determinants, improve our understanding of the pathogenesis of infections caused by this pathogen, and provide the community with a valuable resource for the testing of novel therapeutic agents.

  3. Difference in virulence of environmental isolates of Legionella pneumophila.

    PubMed Central

    Bollin, G E; Plouffe, J F; Para, M F; Prior, R B

    1985-01-01

    Endemic nosocomial Legionnaires disease has occurred at our medical center for several years. Two subtypes of Legionella pneumophila serogroup 1 (UH-1 and RH-1) have been isolated in approximately equal numbers from hospital potable water. However, almost all clinical isolates have been UH-1. To assess potential differences in virulence, 50% lethal doses (LD50) and 50% infective doses (ID50) of UH-1 and RH-1 were determined by intraperitoneal infection in guinea pigs. The UH-1 LD50 was 7.41 X 10(6) CFU, which was significantly lower than the RH-1 LD50 of 9.12 X 10(7) CFU (P = 0.0001). The mean time to death in UH-1-infected guinea pigs was also significantly shorter than in RH-1-infected animals (P = 0.0008). The UH-1 ID50 was 5.8 X 10(3) CFU, and although it was lower than the RH-1 ID50 of 1.4 X 10(4) CFU, this difference was not statistically significant (P = 0.21). This study demonstrates a difference in virulence between UH-1 and RH-1 in guinea pigs. Differences in strain virulence, as demonstrated between these two subtypes, may help to explain the widespread isolation of L. pneumophila from the environment contrasted with the limited occurrence of human Legionnaires disease. PMID:3998095

  4. Determination of antifungal susceptibility patterns among the environmental isolates of Aspergillus fumigatus in Iran

    PubMed Central

    Mohammadi, Faezeh; Dehghan, Parvin; Nekoeian, Shahram; Hashemi, Seyed Jamal

    2016-01-01

    Background: In recent years, triazole-resistant environmental isolates of Aspergillus fumigatus have emerged in Europe and Asia. Azole resistance has been reported in patients who are treated with long-term azole therapy or exposure of the fungus spores to the azole fungicides used in agriculture. To date, a wide range of mutations in A. fumigatus have been described conferring azole-resistance, which commonly involves modifications in the cyp51A gene. We investigated antifungal susceptibility pattern of environmental isolates of A. fumigatus. Materials and Methods: In this study, 170 environmental samples collected from indoors surfaces of three hospitals in Iran. It was used β-tubulin gene to confirm the all of A. fumigatus isolates, which was identified by conventional methods. Furthermore, the antifungal susceptibility of itraconazole, voriconazole, and posaconazole was investigated using broth microdilution test, according to European Committee on Antimicrobial Susceptibility testing reference method. Results: From a total of 158 environmental molds fungi obtained from the hospitals, 58 isolates were identified as A. fumigatus by amplification of expected size of β-tubulin gene (~500 bp). In this study, in vitro antifungal susceptibility testing has shown that there were not high minimum inhibitory concentration values of triazole antifungals in all of the 58 environmental isolates of A. fumigatus. Conclusion: Our findings demonstrated that there was not azole-resistant among environmental isolates of A. fumigatus. Medical triazoles compounds have structural similarity with triazole fungicide compounds in agriculture, therefore, resistance development through exposure to triazole fungicide compounds in the environment is important but it sounds there is not a serious health problem in drug resistance in environmental isolates in Iran. PMID:27656605

  5. Environmental isolates of fungi from aquarium pools housing killer whales (Orcinus orca).

    PubMed

    Kohata, Erina; Kano, Rui; Akune, Yuichiro; Ohno, Yoshito; Soichi, Makoto; Yanai, Tokuma; Hasegawa, Atsuhiko; Kamata, Hiroshi

    2013-12-01

    Systemic mycoses in killer whales (Orcinus orca) are rare diseases, but have been reported. Two killer whales died by fungal infections at the Port of Nagoya Public Aquarium in Japan. In this study, the fungal flora of the pool environment at the aquarium was characterized. Alternaria spp., Aspergillus spp. (A. fumigatus, A. niger, A. versicolor), Fusarium spp. and Penicillium spp. were isolated from the air and the pool surroundings. The other isolates were identified as fungal species non-pathogenic for mammals. However, the species of fungi isolated from the environmental samples in this study were not the same as those isolated from the cases of disease in killer whales previously reported.

  6. Isolation of new Brazilian giant viruses from environmental samples using a panel of protozoa

    PubMed Central

    Dornas, Fábio P.; Khalil, Jacques Y. B.; Pagnier, Isabelle; Raoult, Didier; Abrahão, Jônatas; La Scola, Bernard

    2015-01-01

    The Megavirales are a newly described order capable of infecting different types of eukaryotic hosts. For the most part, the natural host is unknown. Several methods have been used to detect these viruses, with large discrepancies between molecular methods and co-cultures. To isolate giant viruses, we propose the use of different species of amoeba as a cellular support. The aim of this work was to isolate new Brazilian giant viruses by comparing the protozoa Acanthamoeba castellanii, A. polyphaga, A. griffini, and Vermamoeba vermiformis (VV) as a platform for cellular isolation using environmental samples. One hundred samples were collected from 3 different areas in September 2014 in the Pampulha lagoon of Belo Horizonte city, Minas Gerais, Brazil. PCR was used to identify the isolated viruses, along with hemacolor staining, labelling fluorescence and electron microscopy. A total of 69 viruses were isolated. The highest ratio of isolation was found in A. polyphaga (46.38%) and the lowest in VV (0%). Mimiviruses were the most frequently isolated. One Marseillevirus and one Pandoravirus were also isolated. With Brazilian environmental samples, we demonstrated the high rate of lineage A mimiviruses. This work demonstrates how these viruses survive and circulate in nature as well the differences between protozoa as a platform for cellular isolation. PMID:26500630

  7. Isolation of new Brazilian giant viruses from environmental samples using a panel of protozoa.

    PubMed

    Dornas, Fábio P; Khalil, Jacques Y B; Pagnier, Isabelle; Raoult, Didier; Abrahão, Jônatas; La Scola, Bernard

    2015-01-01

    The Megavirales are a newly described order capable of infecting different types of eukaryotic hosts. For the most part, the natural host is unknown. Several methods have been used to detect these viruses, with large discrepancies between molecular methods and co-cultures. To isolate giant viruses, we propose the use of different species of amoeba as a cellular support. The aim of this work was to isolate new Brazilian giant viruses by comparing the protozoa Acanthamoeba castellanii, A. polyphaga, A. griffini, and Vermamoeba vermiformis (VV) as a platform for cellular isolation using environmental samples. One hundred samples were collected from 3 different areas in September 2014 in the Pampulha lagoon of Belo Horizonte city, Minas Gerais, Brazil. PCR was used to identify the isolated viruses, along with hemacolor staining, labelling fluorescence and electron microscopy. A total of 69 viruses were isolated. The highest ratio of isolation was found in A. polyphaga (46.38%) and the lowest in VV (0%). Mimiviruses were the most frequently isolated. One Marseillevirus and one Pandoravirus were also isolated. With Brazilian environmental samples, we demonstrated the high rate of lineage A mimiviruses. This work demonstrates how these viruses survive and circulate in nature as well the differences between protozoa as a platform for cellular isolation.

  8. Molecular and physiological evaluation of subtropical environmental isolates of Acanthamoeba spp., causal agent of Acanthamoeba keratitis.

    PubMed

    Booton, Gregory C; Rogerson, Andrew; Bonilla, Tonya D; Seal, David V; Kelly, Daryl J; Beattie, Tara K; Tomlinson, Alan; Lares-Villa, Fernando; Fuerst, Paul A; Byers, Thomas J

    2004-01-01

    Previous molecular examination of Acanthamoeba spp. has resulted in the determination of distinct genotypes in this genus (designated T1-T12, T14). Genotype T4 has been responsible for the majority of cases of Acanthamoeba keratitis. Here we examine the relative abundance of environmental T4 isolates on beaches and ask whether they have temperature and salinity tolerances that could enhance pathogenicity. Twenty-four Acanthamoeba strains were isolated from beach sand (n = 20), soil (n = 3), and tap water (n = 1) in south Florida. Phylogenetic analysis identified 19 of 24 isolates as T4, the Acanthamoeba keratitis-associated genotype. The remaining isolates were genotype T5 (4) and T11 (1). Nearly all beach isolates were genotype T4, whereas the tap water and soil isolates were mostly T5. All amoebae grew at 0, 1.0, and 2.0% salt and 19 of 20 beach isolates also grew at 3.2%. No soil or tap-water acanthamoebae reproduced at 3.2%. All isolates grew at 37 degrees C and two (T5) at 42 degrees C. Little correlation existed between beach location, salt-tolerance, and genetic relatedness. Overall, the large majority of environmental isolates obtained were genotype T4, suggesting it may be the most common genotype in this environment and could be a potential source of Acanthamoeba keratitis infections.

  9. Nontuberculous Mycobacteria Isolation from Clinical and Environmental Samples in Iran: Twenty Years of Surveillance.

    PubMed

    Velayati, Ali Akbar; Farnia, Parissa; Mozafari, Mohadese; Mirsaeidi, Mehdi

    2015-01-01

    Nontuberculous mycobacteria (NTM) are opportunistic pathogens that are widely distributed in the environment. There is a lack of data on species distribution of these organisms from Iran. This study consists of a review of NTM articles published in Iran between the years 1992 and 2014. In this review, 20 articles and 14 case reports were identified. Among the 20 articles, 13 (65%) studies focused on NTM isolates from clinical specimens, 6 (30%) studies examined NTM isolates from environmental samples, and one (5%) article included both clinical and environmental isolates. M. fortuitum (229/997; 23%) was recorded as the most prevalent and rapid growing mycobacteria (RGM) species in both clinical (28%) and environmental (19%) isolated samples (P < 0.05). Among slow growing mycobacteria (SGM), M. simiae (103/494; 21%) demonstrated a higher frequency in clinical samples whereas in environmental samples it was M. flavescens (44/503; 9%). These data represent information from 14 provinces out of 31 provinces of Iran. No information is available in current published data on clinical or environmental NTM from the remaining 17 provinces in Iran. These results emphasize the potential importance of NTM as well as the underestimation of NTM frequency in Iran. NTM is an important clinical problem associated with significant morbidity and mortality in Iran. Continued research is needed from both clinical and environmental sources to help clinicians and researchers better understand and address NTM treatment and prevention.

  10. Campylobacter jejuni Isolation/Enumeration from Environmental Samples.

    PubMed

    Hiett, Kelli L

    2017-01-01

    Currently, there is no universally accepted standard media or method for the recovery of Campylobacter species. This is likely due to the ubiquity of the organism in nature, the complex sample matrices from which the organism is often recovered, as well as the fragile/viable-but nonculturable state the organism assumes in response to stress. The use of a sterile filter placed upon a nonselective Brucella Agar Blood Plate (BAB), followed by incubation at 37 °C in a hydrogen-containing atmosphere (Campycheck), is one method to recover stressed and emerging Campylobacter spp. from complex environmental matrices; however, this technique does not currently allow for the enumeration of the recovered organisms. Enumeration is performed using serial dilutions of sample homogenate plated onto modified Campy-Cefex media followed by incubation at either 37 °C or 42 °C in a microaerobic atmosphere.

  11. First environmental isolation of Cryptococcus gattii, genotype AFLP5, from India and a global review.

    PubMed

    Chowdhary, A; Prakash, A; Randhawa, H S; Kathuria, S; Hagen, F; Klaassen, C H; Meis, J F

    2013-05-01

    We report the first environmental isolation from India of Cryptococcus gattii, genotype amplified fragment length polymorphism 5 (AFLP5), which is one of the rarely reported genotypes of this pathogen. It originated from decayed wood inside a trunk hollow of Manilkara hexandra, a native tree in Delhi. We investigated 101 isolates of C. gattii, originating from 556 samples of decayed wood inside trunk hollows of 311 heterogeneous tree species and their surrounding soil. Of these, only a solitary isolate proved to be AFLP5, the remainder belonged to AFLP4. Antifungal susceptibility testing showed a low MIC90 (0.25 μg ml(-1) ) of the new azoles posaconazole and isavuconazole for these environmental isolates. Genotype AFLP5 has been mainly reported from environmental sources in Colombia and from clinical sources in California (USA), where it seems to be endemic. Phylogenetic analysis of multi-locus sequence typing data showed that the Indian AFLP5 C. gattii isolate had a distinct profile compared with a cluster of mainly Colombian and Californian C. gattii AFLP5 isolates. As molecular typing of human pathogenic fungi is still in its infancy and not accessible to many countries, our current knowledge cannot be taken as reflective of the true geographic distribution of C. gattii AFLP5 or its other rarely reported molecular types.

  12. Environmental management assessment of the Waste Isolation Pilot Plant (WIPP), Carlsbad, New Mexico

    SciTech Connect

    Not Available

    1993-07-01

    This document contains the results of the Environmental Management Assessment of the Waste Isolation Pilot Plant (WIPP). This Assessment was conducted by EH-24 from July 19 through July 30, 1993 to advise the Secretary of Energy of the adequacy of management systems established at WIPP to ensure the protection of the environment and compliance with Federal, state, and DOE environmental requirements. The mission of WIPP is to demonstrate the safe disposal of transuranic (TRU) waste. During this assessment, activities and records were reviewed and interviews were conducted with personnel from the management and operating contractors. This assessment revealed that WIPP`s environmental safety and health programs are satisfactory, and that all levels of the Waste Isolation Division (WID) management and staff consistently exhibit a high level of commitment to achieve environmental excellence.

  13. Epinecidin-1 Has Immunomodulatory Effects, Facilitating Its Therapeutic Use in a Mouse Model of Pseudomonas aeruginosa Sepsis

    PubMed Central

    Pan, Chieh-Yu; Chen, Jian-Chyi; Sheen, Jenn-Feng; Lin, Tai-Lang

    2014-01-01

    Antimicrobial peptides (AMPs) are garnering attention as possible alternatives to antibiotics. Here, we describe the antimicrobial properties of epinecidin-1 against a multidrug-resistant clinical isolate of P. aeruginosa (P. aeruginosa R) and a P. aeruginosa strain from ATCC (P. aeruginosa ATCC 19660) in vivo. The MICs of epinecidin-1 against P. aeruginosa R and P. aeruginosa ATCC 19660 were determined and compared with those of imipenem. Epinecidin-1 was found to be highly effective at combating peritonitis infection caused by P. aeruginosa R or P. aeruginosa ATCC 19660 in mouse models, without inducing adverse behavioral effects or liver or kidney toxicity. Taken together, our results indicate that epinecidin-1 enhances the rate of survival of mice infected with the bacterial pathogen P. aeruginosa through both antimicrobial and immunomodulatory effects. PMID:24820078

  14. In Vitro Activities of Amphotericin B, Terbinafine, and Azole Drugs against Clinical and Environmental Isolates of Aspergillus terreus Sensu Stricto

    PubMed Central

    Fernández, Mariana S.; Rojas, Florencia D.; Cattana, María E.; Sosa, María de los Ángeles; Iovannitti, Cristina A.; Giusiano, Gustavo E.

    2015-01-01

    The antifungal susceptibilities of 40 clinical and environmental isolates of A. terreus sensu stricto to amphotericin B, terbinafine, itraconazole, and voriconazole were determined in accordance with CLSI document M38-A2. All isolates had itraconazole and voriconazole MICs lower than epidemiologic cutoff values, and 5% of the isolates had amphotericin B MICs higher than epidemiologic cutoff values. Terbinafine showed the lowest MICs. No significant differences were found when MICs of clinical and environmental isolates were compared. PMID:25824228

  15. Molecular epidemiology of Pseudomonas aeruginosa in an intensive care unit.

    PubMed Central

    Döring, G.; Hörz, M.; Ortelt, J.; Grupp, H.; Wolz, C.

    1993-01-01

    Genotyping was used to analyse Pseudomonas aeruginosa isolates from sink drains and 15 intubated patients as part of a 3-month prospective study of strain transmission in a medical-surgical intensive care unit. Ninety percent of all washbasin drains were persistently contaminated with several P. aeruginosa genotypes. In 60% (9/15) of the patients, P. aeruginosa colonization or infection was hospital-acquired: P. aeruginosa strains isolated from these patients were present in hospital sinks or in other patients before their admission. Since all patients were immobile, personnel were the probable route of transmission of P. aeruginosa in the hospital. The mechanism of strain transmission from sinks to hands during hand washing was investigated in a children's hospital. When P. aeruginosa was present at densities of > 10(5)/c.f.u. per ml in sink drains, hand washing resulted in hand contamination with P. aeruginosa via aerosol generation in the majority of experiments or P. aeruginosa was detected using an air sampler above the washing basin. High P. aeruginosa cfu were present at 4.30 h in the eight sinks (5.4 x 10(5)-7.0 x 10(10) c.f.u./ml), whereas at 13.00 h P. aeruginosa c.f.u. were significantly lower (3.1 x 10(2)-8.0 x 10(5) c.f.u./ml). These data reveal that the danger of bacterial contamination of hands during hand washing is highest in the morning. The identified transmission routes demand more effective hygienic measures in hospital settings particularly concerning personnel hands and sink drains. Images Fig. 1 PMID:8519308

  16. Assessment of polyaromatic hydrocarbon degradation by potentially pathogenic environmental Vibrio parahaemolyticus isolates from coastal Louisiana, USA.

    PubMed

    Smith, Conor B; Johnson, Crystal N; King, Gary M

    2012-01-01

    A presumed Vibrio parahaemolyticus isolate from Chesapeake Bay, Maryland, USA was previously reported to grow on phenanthrene, a polyaromatic hydrocarbon (PAH) found in crude oil. Following the Deepwater Horizon oil spill in the Gulf of Mexico, concerns were raised that PAH-degrading V. parahaemolyticus could increase in abundance, leading to elevated risks of disease derived from shellfish consumption. To assess this possibility, we examined responses to naphthalene and phenanthrene of 17 coastal Louisiana environmental V. parahaemolyticus isolates representing five distinct genotypes. Isolates were obtained immediately after the spill began and after oil had reached the Louisiana coast. None of the isolates grew on or oxidized either substrate and a naphthalene degradation product, 1-naphthol, substantially inhibited growth of some isolates. The use of PAH by V. parahaemolyticus is unusual, and an increase in human health risks due to stimulation of V. parahaemolyticus growth by oil-derived PAH under in situ conditions appears unlikely.

  17. First environmental isolations of Cryptococcus neoformans and Cryptococcus gattii in Tunisia and review of published studies on environmental isolations in Africa.

    PubMed

    Mseddi, F; Sellami, A; Jarboui, M A; Sellami, H; Makni, F; Ayadi, A

    2011-05-01

    Cryptococcus neoformans and Cryptococcus gattii are pathogenic yeasts that cause cryptococcosis. These fungi were commonly associated with pigeon droppings and plant materials. The habitat of these pathogens has not been yet studied in Tunisia, although the ecology of these yeasts must be elucidated in order to establish surveillance programs and to prevent infections. The aim of this survey was to recover C. neoformans and C. gattii environmental isolates from pigeon droppings and plant materials in different areas of Sfax region, Tunisia. Nine hundred and fifty samples from leaves, wood, flowers, fruits and soil around trunk bases of 40 almond (Prunus dulcis) and 60 eucalyptus trees were collected as well as 250 pigeon droppings samples from different sites: buildings (n = 150), houses (n = 50) and zoo (n = 50). The identification of Cryptococcus neoformans complex was confirmed using the ID32C auxanogram panel (BioMérieux, Marcy l'Etoile, France); species were determined by multiplex PCR using the CN70 and CN49 primers, and mating type was determined by PCR. C. neoformans was recovered from 26 specimens of pigeon droppings (10.4%). This yeast was obtained more frequently from dry droppings (9.2%) than from moist droppings (1.2%). The mating type was determined. All the 31 environmental strains of C. neoformans and C. gattii were MATα. Out of 700 samples tested from 100 trees, only 5 isolates of Cryptococcus neoformans species complex were recovered (0.6%), two isolates of C. gattii and one isolate of C. neoformans were recovered from the wood of E. camaldulensis trees, and only two isolates of C. gattii were recovered from the wood of almond trees (Prunus dulcis Mill. var. zaaf and var. achek). These two Tunisian almond tree varieties were recorded for the first time in Africa as hosts for C. gattii. These results add new information to the ecology and epidemiology of C. neoformans species complex in Tunisia.

  18. Environmental phosphate differentially affects virulence phenotypes of uropathogenic Escherichia coli isolates causative of prostatitis

    PubMed Central

    Grillo-Puertas, M; Martínez-Zamora, MG; Rintoul, MR; Soto, SM; Rapisarda, VA

    2015-01-01

    K-12 Escherichia coli cells grown in static media containing a critical phosphate (Pi) concentration ≥25 mM maintained a high polyphosphate (polyP) level in stationary phase, impairing biofilm formation, a phenomenon that is triggered by polyP degradation. Pi concentration in human urine fluctuates according to health state. Here, the influence of environmental Pi concentration on the occurrence of virulence traits in uropathogenic E. coli (UPEC) isolated from acute prostatitis patients was evaluated. After a first screening, 3 isolates were selected according to differential biofilm formation profiles depending on media Pi concentration. For each isolate, biofilm positive and negative conditions were established. Regardless of the isolate, biofilm formation capacity was accompanied with curli and cellulose production and expression of some key virulence factors associated with adhesion. When the selected isolates were grown in their non-biofilm-forming condition, low concentrations of nalidixic acid and ciprofloxacin induced biofilm formation. Interestingly, similar to laboratory strains, polyP degradation induced biofilm formation in the selected isolates. Data demonstrated the complexity of UPEC responses to environmental Pi and the importance of polyP metabolism in the virulence of clinical isolates. PMID:26083279

  19. Biosynthesis of the Pseudomonas aeruginosa Extracellular Polysaccharides, Alginate, Pel, and Psl

    PubMed Central

    Franklin, Michael J.; Nivens, David E.; Weadge, Joel T.; Howell, P. Lynne

    2011-01-01

    Pseudomonas aeruginosa thrives in many aqueous environments and is an opportunistic pathogen that can cause both acute and chronic infections. Environmental conditions and host defenses cause differing stresses on the bacteria, and to survive in vastly different environments, P. aeruginosa must be able to adapt to its surroundings. One strategy for bacterial adaptation is to self-encapsulate with matrix material, primarily composed of secreted extracellular polysaccharides. P. aeruginosa has the genetic capacity to produce at least three secreted polysaccharides; alginate, Psl, and Pel. These polysaccharides differ in chemical structure and in their biosynthetic mechanisms. Since alginate is often associated with chronic pulmonary infections, its biosynthetic pathway is the best characterized. However, alginate is only produced by a subset of P. aeruginosa strains. Most environmental and other clinical isolates secrete either Pel or Psl. Little information is available on the biosynthesis of these polysaccharides. Here, we review the literature on the alginate biosynthetic pathway, with emphasis on recent findings describing the structure of alginate biosynthetic proteins. This information combined with the characterization of the domain architecture of proteins encoded on the Psl and Pel operons allowed us to make predictive models for the biosynthesis of these two polysaccharides. The results indicate that alginate and Pel share certain features, including some biosynthetic proteins with structurally or functionally similar properties. In contrast, Psl biosynthesis resembles the EPS/CPS capsular biosynthesis pathway of Escherichia coli, where the Psl pentameric subunits are assembled in association with an isoprenoid lipid carrier. These models and the environmental cues that cause the cells to produce predominantly one polysaccharide over the others are subjects of current investigation. PMID:21991261

  20. Characterization of Environmentally Persistent Escherichia coli Isolates Leached from an Irish Soil▿

    PubMed Central

    Brennan, Fiona P.; Abram, Florence; Chinalia, Fabio A.; Richards, Karl G.; O'Flaherty, Vincent

    2010-01-01

    Soils are typically considered to be suboptimal environments for enteric organisms, but there is increasing evidence that Escherichia coli populations can become resident in soil under favorable conditions. Previous work reported the growth of autochthonous E. coli in a maritime temperate Luvic Stagnosol soil, and this study aimed to characterize, by molecular and physiological means, the genetic diversity and physiology of environmentally persistent E. coli isolates leached from the soil. Molecular analysis (16S rRNA sequencing, enterobacterial repetitive intergenic consensus PCR, pulsed-field gel electrophoresis, and a multiplex PCR method) established the genetic diversity of the isolates (n = 7), while physiological methods determined the metabolic capability and environmental fitness of the isolates, relative to those of laboratory strains, under the conditions tested. Genotypic analysis indicated that the leached isolates do not form a single genetic grouping but that multiple genotypic groups are capable of surviving and proliferating in this environment. In physiological studies, environmental isolates grew well across a broad range of temperatures and media, in comparison with the growth of laboratory strains. These findings suggest that certain E. coli strains may have the ability to colonize and adapt to soil conditions. The resulting lack of fecal specificity has implications for the use of E. coli as an indicator of fecal pollution in the environment. PMID:20154122

  1. Efficient screening of environmental isolates for Saccharomyces cerevisiae strains that are suitable for brewing.

    PubMed

    Fujihara, Hidehiko; Hino, Mika; Takashita, Hideharu; Kajiwara, Yasuhiro; Okamoto, Keiko; Furukawa, Kensuke

    2014-01-01

    We developed an efficient screening method for Saccharomyces cerevisiae strains from environmental isolates. MultiPlex PCR was performed targeting four brewing S. cerevisiae genes (SSU1, AWA1, BIO6, and FLO1). At least three genes among the four were amplified from all S. cerevisiae strains. The use of this method allowed us to successfully obtain S. cerevisiae strains.

  2. Antimicrobial resistance in Enterococcus spp. isolated from environmental samples in the area of intensive poultry production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study, we investigated antimicrobial resistance of Enterococcus spp. from different environmental compartments including litter from two farms, 12 surface and 28 groundwater sites in an area of intensive poultry production and litter application. The enumerated isolates (n=250) were tested ...

  3. A Mouse Model for Characterization of Gastrointestinal Colonization Rates Among Environmental Aeromonas Isolates

    EPA Science Inventory

    The colonization rates of ten different environmental isolates of Aeromonas were determined using a novel mouse-streptomycin pre-treatment method. A novel streptomycin pre-treatment prepared animals with a transient alteration in colon flora that allowed colonization by Aeromon...

  4. CRISPR Diversity in E. coli Isolates from Australian Animals, Humans and Environmental Waters

    PubMed Central

    Sheludchenko, Maxim S.; Huygens, Flavia; Stratton, Helen; Hargreaves, Megan

    2015-01-01

    Seventy four SNP genotypes and 54 E. coli genomes from kangaroo, Tasmanian devil, reptile, cattle, dog, horse, duck, bird, fish, rodent, human and environmental water sources were screened for the presence of the CRISPR 2.1 loci flanked by cas2 and iap genes. CRISPR 2.1 regions were found in 49% of the strains analysed. The majority of human E. coli isolates lacked the CRISPR 2.1 locus. We described 76 CRISPR 2.1 positive isolates originating from Australian animals and humans, which contained a total of 764 spacer sequences. CRISPR arrays demonstrated a long history of phage attacks especially in isolates from birds (up to 40 spacers). The most prevalent spacer (1.6%) was an ancient spacer found mainly in human, horse, duck, rodent, reptile and environmental water sources. The sequence of this spacer matched the intestinal P7 phage and the pO111 plasmid of E. coli. PMID:25946192

  5. CRISPR Diversity in E. coli Isolates from Australian Animals, Humans and Environmental Waters.

    PubMed

    Sheludchenko, Maxim S; Huygens, Flavia; Stratton, Helen; Hargreaves, Megan

    2015-01-01

    Seventy four SNP genotypes and 54 E. coli genomes from kangaroo, Tasmanian devil, reptile, cattle, dog, horse, duck, bird, fish, rodent, human and environmental water sources were screened for the presence of the CRISPR 2.1 loci flanked by cas2 and iap genes. CRISPR 2.1 regions were found in 49% of the strains analysed. The majority of human E. coli isolates lacked the CRISPR 2.1 locus. We described 76 CRISPR 2.1 positive isolates originating from Australian animals and humans, which contained a total of 764 spacer sequences. CRISPR arrays demonstrated a long history of phage attacks especially in isolates from birds (up to 40 spacers). The most prevalent spacer (1.6%) was an ancient spacer found mainly in human, horse, duck, rodent, reptile and environmental water sources. The sequence of this spacer matched the intestinal P7 phage and the pO111 plasmid of E. coli.

  6. Metabolic phenotype of clinical and environmental Mycobacterium avium subsp. hominissuis isolates

    PubMed Central

    Sanchini, Andrea; Dematheis, Flavia; Semmler, Torsten

    2017-01-01

    Background Mycobacterium avium subsp. hominissuis (MAH) is an emerging opportunistic human pathogen. It can cause pulmonary infections, lymphadenitis and disseminated infections in immuno-compromised patients. In addition, MAH is widespread in the environment, since it has been isolated from water, soil or dust. In recent years, knowledge on MAH at the molecular level has increased substantially. In contrast, knowledge of the MAH metabolic phenotypes remains limited. Methods In this study, for the first time we analyzed the metabolic substrate utilization of ten MAH isolates, five from a clinical source and five from an environmental source. We used BIOLOG Phenotype MicroarrayTM technology for the analysis. This technology permits the rapid and global analysis of metabolic phenotypes. Results The ten MAH isolates tested showed different metabolic patterns pointing to high intra-species diversity. Our MAH isolates preferred to use fatty acids such as Tween, caproic, butyric and propionic acid as a carbon source, and L-cysteine as a nitrogen source. Environmental MAH isolates resulted in being more metabolically active than clinical isolates, since the former metabolized more strongly butyric acid (p = 0.0209) and propionic acid (p = 0.00307). Discussion Our study provides new insight into the metabolism of MAH. Understanding how bacteria utilize substrates during infection might help the developing of strategies to fight such infections. PMID:28070460

  7. Exposure to an environmental estrogen breaks down sexual isolation between native and invasive species

    PubMed Central

    Ward, Jessica L; Blum, Michael J

    2012-01-01

    Environmental change can increase the likelihood of interspecific hybridization by altering properties of mate recognition and discrimination between sympatric congeners. We examined how exposure to an environmentally widespread endocrine-disrupting chemical (EDC), bisphenol A (BPA), affected visual communication signals and behavioral isolation between an introduced freshwater fish and a native congener (genus: Cyprinella). Exposure to BPA induced changes in the expression of male secondary traits as well as male and female mate choice, leading to an overall reduction in prezygotic isolation between congeners. Changes in female mate discrimination were not tightly linked to changes in male phenotypic traits, suggesting that EDC exposure may alter female choice thresholds independently of the effects of exposure on males. These findings indicate that environmental exposure to EDCs can lead to population declines via the erosion of species boundaries and by promoting the establishment and spread of non-native species via hybridization. PMID:23346234

  8. Waste Isolation Pilot Plant Site Environmental Report for calendar year 1989

    SciTech Connect

    Not Available

    1989-01-01

    This is the 1989 Site Environmental Report (SER) for the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico. The WIPP is a government owned and contractor-operated facility. The WIPP project is operated by Westinghouse Electric Corporation for the US Department of Energy (DOE). The mission of the WIPP is to provide a research and development facility to demonstrate the safe disposal of transuranic (TRU) waste generated by the defense activities of the US Government. This report provides a comprehensive description of environmental activities at the WIPP during calendar year 1989. The WIPP facility will not receive waste until all concerns affecting opening the WIPP are addressed to the satisfaction of the Secretary of Energy. Therefore, this report describes the status of the preoperational activities of the Radiological Environmental Surveillance (RES) program, which are outlined in the Radiological Baseline Program for the Waste Isolation Pilot Plant (WTSD-TME-057). 72 refs., 13 figs., 20 tabs.

  9. Molecular screening of 246 Portuguese Aspergillus isolates among different clinical and environmental sources.

    PubMed

    Sabino, Raquel; Veríssimo, Cristina; Parada, Helena; Brandão, João; Viegas, Carla; Carolino, Elisabete; Clemons, Karl V; Stevens, David A

    2014-07-01

    Clinical and environmental samples from Portugal were screened for the presence of Aspergillus and the distributions of the species complexes were determined in order to understand how their distributions differ based on their source. Fifty-seven Aspergillus isolates from clinical samples were collected from 10 health institutions. Six species complexes were detected by internal transcribed spacer sequencing; Fumigati, Flavi, and Nigri were found most frequently (50.9%, 21.0%, and 15.8%, respectively). β-tubulin and calmodulin sequencing resulted in seven cryptic species (A. awamorii, A. brasiliensis, A. fructus, A. lentulus, A. sydowii, A. tubingensis, Emericella echinulata) being identified among the 57 isolates. Thirty-nine isolates of Aspergillus were recovered from beach sand and poultry farms, 31 from swine farms, and 80 from hospital environments, for a total 189 isolates. Eleven species complexes were found in these 189 isolates, and those belonging to the Versicolores species complex were found most frequently (23.8%). There was a significant association between the different environmental sources and distribution of the species complexes; the hospital environment had greater variability of species complexes than other environmental locations. A high prevalence of cryptic species within the Circumdati complex was detected in several environments; from the isolates analyzed, at least four cryptic species were identified, most of them growing at 37ºC. Because Aspergillus species complexes have different susceptibilities to antifungals, knowing the species-complex epidemiology for each setting, as well as the identification of cryptic species among the collected clinical isolates, is important. This may allow preventive and corrective measures to be taken, which may result in decreased exposure to those organisms and a better prognosis.

  10. Sequence types diversity of Legionella pneumophila isolates from environmental water sources in Guangzhou and Jiangmen, China.

    PubMed

    Guo, Jingyu; Liang, Ting; Hu, Chaohui; Lv, Ruichen; Yang, Xianwei; Cui, Yujun; Song, Youtao; Yang, Ruifu; Zhu, Qingyi; Song, Yajun

    2015-01-01

    In this study, 159 Legionella pneumophila strains isolated from various natural and artificial water sources in Guangzhou and Jiangmen, China, were subjected to genotyping by the sequence-based typing (SBT) scheme. These isolates were assigned into 53 sequence types (STs) (50 STs with seven loci data and three unidentified STs with incomplete loci profiles) with ST1 as the dominant one (14.5%), and the index of diversity (IOD) was 0.950. Eight new alleles and 34 new STs were reported here. Notably, most of the newly identified STs with seven loci data (24/34) contained no new allele, implying frequent recombination events in L. pneumophila. Five intragenic recombination events were identified in the concatenated sequences of seven loci. The diversity of STs in natural environmental isolates (41 STs, IOD=0.956) is higher than that of artificial environmental ones (17 STs, IOD=0.824). The ST patterns varied in isolates from these two sources: the most common STs from artificial water sources, ST1 and ST752 (39.2% and 13.7%), were only occasionally isolated from natural water sources (2.9% and 3.8%, respectively); while the predominant STs from natural water sources, ST1048, ST739 and ST1267 (15.2%, 6.7% and 6.7%), were less frequently seen in artificial environments (2.0%, 0% and 0%, respectively). We also found out that Legionnaires' disease associated STs might be more frequently isolated in artificial environments than in natural ones. Our data revealed remarkable genetic diversity of L. pneumophila isolates from environmental water systems of Guangzhou and Jiangmen, and the different ST distribution patterns between natural water and artificial water sources as well.

  11. Waste Isolation Pilot Plant site environmental report, for calendar year 1995

    SciTech Connect

    1996-09-01

    The U.S. Department of Energy (DOE) Order 5400.1 General Environmental Protection Program, requires DOE facilities, that conduct environmental protection programs, to annually prepare a Site Environmental Report (SER). The purpose of the SER is to provide an abstract of environmental assessments conducted in order to characterize site environmental management performance, to confirm compliance with environmental standards and requirements, and to highlight significant programs and efforts of environmental merit. The content of this SER is not restricted to a synopsis of the required data, in addition, information pertaining to new and continued monitoring and compliance activities during the 1995 calendar year are also included. Data contained in this report are derived from those monitoring programs directed by the Waste Isolation Pilot Plant (WIPP) Environmental Monitoring Plan (EMP). The EMP provides inclusive guidelines implemented to detect potential impacts to the environment and to establish baseline measurements for future environmental evaluations. Surface water, groundwater. air, soil, and biotic matrices are monitored for an array of radiological and nonradiological factors. The baseline radiological surveillance program encompasses a broader geographic area that includes nearby ranches, villages, and cities. Most elements of nonradiological assessments are conducted within the geographic vicinity of the WIPP site.

  12. Isolation and genetic analysis of an environmental bacteriophage: A 10-session laboratory series in molecular virology.

    PubMed

    Williamson, Ryan P; Barker, Brent T; Drammeh, Hamidou; Scott, Jefferson; Lin, Joseph

    2014-01-01

    Bacterial viruses, otherwise known as bacteriophage (or phage), are some of the most abundant viruses found in the environment. They can be easily isolated from water or soil and are ideal for use in laboratory classrooms due to their ease of culture and inherent safety. Here, we describe a series of 10 laboratory exercises where students collect, isolate, and purify the genome of an environmental phage. Once the genome has been extracted, students then clone a fragment of their isolated phage genome into a plasmid and analyze its sequence to identify the phage in their original isolate. These exercises have been carefully designed to apply foundational concepts that will expose students to basic skills in microbiology, molecular biology, and bioinformatics.

  13. Susceptibility profile of clinical and environmental isolates of Cryptococcus neoformans and Cryptococcus gattii in Uberaba, Minas Gerais, Brazil.

    PubMed

    Andrade-Silva, Leonardo; Ferreira-Paim, Kennio; Mora, Delio Jose; Da Silva, Paulo Roberto; Andrade, Anderson Assunção; Araujo, Natalia Evelyn; Pedrosa, André Luiz; Silva-Vergara, Mario León

    2013-08-01

    Cryptococcus neoformans and C. gattii are the etiologic agents of cryptococcosis, a life-threatening disease in both immunocompromised and immunocompetent hosts. Antifungal resistance has been evaluated using different methods, breakpoints, and sizes of test populations and it is an emerging as a significant issue worldwide. A total of 176 (95 clinical and 81 environmental) C. neoformans and eight clinical C. gattii isolates were evaluated to determine the minimal inhibitory concentration (MIC) according to the Clinical and Laboratory Standards Institute method. A total of 10.5% of the C. neoformans clinical isolates were resistant to amphotericin B (AMB), and 6.2% of the environmental isolates were resistant to fluconazole (FLZ). Environmental and clinical isolates presented epidemiologic cut-off values (ECVs) of 64 and 16 to FLZ and 1 and 2 to AMB, respectively. All of the C. gattii isolates showed high susceptibility to most drugs evaluated. Clinical isolates had lower susceptibility than environmental isolates to AMB and itraconazole whereas environmental isolates had lower susceptibility than the clinical isolates to FLZ, voriconazole, and ketoconazole. However, no difference was found in the susceptibility of the two species. The MICs and ECVs to antifungals can help to select the best therapeutic option for tracking epidemiological resistance among clinical and environmental isolates of Cryptococcus spp. around the world.

  14. Interactions with lectins and agglutination profiles of clinical, food, and environmental isolates of Listeria.

    PubMed Central

    Facinelli, B; Giovanetti, E; Casolari, C; Varaldo, P E

    1994-01-01

    On the basis of preliminary trials with 14 collection strains of Listeria, five lectins (Canavalia ensiformis, concanavalin A; Griffonia simplicifolia lectin I; Helix pomatia agglutinin; Ricinus communis agglutinin; and Triticum vulgaris wheat germ agglutinin) were selected to set up a microtiter agglutination assay. The lectin agglutination profiles of 174 clinical, food, and environmental strains of Listeria monocytogenes, Listeria innocua, and Listeria seeligeri were investigated. Data on the standard determination of the antigenic structure were available for clinical strains; nonclinical isolates were assigned to serogroup 1 or 4 with commercial antisera. The listeria-lectin interaction was related to serological type rather than species; in particular, the strains assigned to serogroup 1 or belonging to serovars 1/2a, 1/2b, 1/2c, 3a, 3b, and 7 were never agglutinated by G. simplicifolia lectin I. The five-lectin set proved to be capable of detecting differences between serologically identical isolates of L. monocytogenes. Of the 150 isolates of this species, 144 were distributed over 15 different lectin agglutination profiles and 6 autoagglutinated, the overall typeability being 96%. However, the profiles encountered among L. monocytogenes isolates were not randomly distributed. With strains assigned to serogroup 1 or belonging to serovars 1/2a, 1/2b, 1/2c, and 3b, the clinical isolates fell into only two of the eight patterns recorded overall; with strains of serogroup 4 and serovar 4b, food and environmental isolates were distributed over eight of the nine patterns found in total, while clinical isolates were distributed over five patterns. In a comparative study of 15 epidemiologically relevant isolates of L. monocytogenes from five distinct outbreaks, strains with identical phage types and/or DNA fingerprints displayed identical lectin profiles. The heterogeneity of agglutination profiles may form the basis of a new approach to L. monocytogenes typing

  15. Genetic diversity of Enterococcus faecalis isolated from environmental, animal and clinical sources in Malaysia.

    PubMed

    Daniel, Diane S; Lee, Sui M; Gan, Han M; Dykes, Gary A; Rahman, Sadequr

    2017-02-18

    Enterococcus faecalis ranks as one of the leading causes of nosocomial infections. A strong epidemiological link has been reported between E. faecalis inhabiting animals and environmental sources. This study investigates the genetic diversity, antibiotic resistance and virulence determinants in E. faecalis from three sources in Malaysia. A total of 250 E. faecalis isolates were obtained consisting of 120 isolates from farm animals, 100 isolates from water sources and 30 isolates from hospitalized patients. Pulse-field gel electrophoresis-typing yielded 63 pulsotypes, with high diversity observed in all sources (D=≥0.901). No pulsotype was common to all the three sources. Each patient room had its own unique PFGE pattern which persisted after six months. Minimum inhibitory concentrations of Vancomycin, Gentamicin, Penicillin, Tetracycline, Nitrofurantoin, Levofloxacin, Ciprofloxacin and Fosfomycin were evaluated. Resistance to Tetracycline was most prevalent in isolates from farm animals (62%) and water sources (49%). Water isolates (86%) had a higher prevalence of the asa1 gene, which encodes for aggregation substance, whereas clinical (78%) and farm animal isolates (87%) had a higher prevalence of the esp gene, encoding a surface exposed protein. This study generates knowledge on the genetic diversity of E. faecalis with antibiotic resistance and virulence characteristics from various sources in Malaysia.

  16. Biofilm formation and genetic diversity of Salmonella isolates recovered from clinical, food, poultry and environmental sources.

    PubMed

    Nair, Amruta; Rawool, Deepak B; Doijad, Swapnil; Poharkar, Krupali; Mohan, Vysakh; Barbuddhe, Sukhadeo B; Kolhe, Rahul; Kurkure, Nitin V; Kumar, Ashok; Malik, S V S; Balasaravanan, T

    2015-12-01

    In the present study, Salmonella isolates (n=40) recovered from clinical, food, poultry and environmental sources were characterized for serotype identification, genetic diversity and biofilm formation capability. Serotype identification using multiplex PCR assay revealed six isolates to be Salmonella Typhimurium, 14 as Salmonella Enteritidis, 11 as Salmonella Typhi, and the remaining nine isolates unidentified were considered as other Salmonella spp. Most of the Salmonella isolates (85%) produced biofilm on polystyrene surfaces as assessed by microtitre plate assay. About 67.5% isolates were weak biofilm producers and 17.5% were moderate biofilm producers. There was no significant difference in biofilm-forming ability among the Salmonella isolates recovered from different geographical regions or different sources. Among the genetic methods, Enterobacterial Repetitive Intergenic Consensus (ERIC) PCR revealed greater discriminatory power (DI, 0.943) followed by pulsed field gel electrophoresis (PFGE) (DI, 0.899) and random amplification of polymorphic DNA (RAPD) PCR (DI, 0.873). However, composite analysis revealed the highest discrimination index (0.957). Greater discrimination of S. Typhimurium and S. Typhi was achieved using PFGE, while ERIC PCR was better for S. Enteritidis and other Salmonella serotypes. A strong positive correlation (r=0.992) was observed between biofilm formation trait and clustered Salmonella isolates in composite genetic analysis.

  17. Acanthamoeba polyphaga mimivirus stability in environmental and clinical substrates: implications for virus detection and isolation.

    PubMed

    Dornas, Fábio P; Silva, Lorena C F; de Almeida, Gabriel M; Campos, Rafael K; Boratto, Paulo V M; Franco-Luiz, Ana P M; La Scola, Bernard; Ferreira, Paulo C P; Kroon, Erna G; Abrahão, Jônatas S

    2014-01-01

    Viruses are extremely diverse and abundant and are present in countless environments. Giant viruses of the Megavirales order have emerged as a fascinating research topic for virologists around the world. As evidence of their ubiquity and ecological impact, mimiviruses have been found in multiple environmental samples. However, isolation of these viruses from environmental samples is inefficient, mainly due to methodological limitations and lack of information regarding the interactions between viruses and substrates. In this work, we demonstrate the long-lasting stability of mimivirus in environmental (freshwater and saline water) and hospital (ventilator plastic device tube) substrates, showing the detection of infectious particles after more than 9 months. In addition, an enrichment protocol was implemented that remarkably increased mimivirus detection from all tested substrates, including field tests. Moreover, biological, morphological and genetic tests revealed that the enrichment protocol maintained mimivirus particle integrity. In conclusion, our work demonstrated the stability of APMV in samples of environmental and health interest and proposed a reliable and easy protocol to improve giant virus isolation. The data presented here can guide future giant virus detection and isolation studies.

  18. Acanthamoeba polyphaga mimivirus Stability in Environmental and Clinical Substrates: Implications for Virus Detection and Isolation

    PubMed Central

    de Almeida, Gabriel M.; Campos, Rafael K.; Boratto, Paulo V. M.; Franco-Luiz, Ana P. M.; La Scola, Bernard; Ferreira, Paulo C. P.; Kroon, Erna G.; Abrahão, Jônatas S.

    2014-01-01

    Viruses are extremely diverse and abundant and are present in countless environments. Giant viruses of the Megavirales order have emerged as a fascinating research topic for virologists around the world. As evidence of their ubiquity and ecological impact, mimiviruses have been found in multiple environmental samples. However, isolation of these viruses from environmental samples is inefficient, mainly due to methodological limitations and lack of information regarding the interactions between viruses and substrates. In this work, we demonstrate the long-lasting stability of mimivirus in environmental (freshwater and saline water) and hospital (ventilator plastic device tube) substrates, showing the detection of infectious particles after more than 9 months. In addition, an enrichment protocol was implemented that remarkably increased mimivirus detection from all tested substrates, including field tests. Moreover, biological, morphological and genetic tests revealed that the enrichment protocol maintained mimivirus particle integrity. In conclusion, our work demonstrated the stability of APMV in samples of environmental and health interest and proposed a reliable and easy protocol to improve giant virus isolation. The data presented here can guide future giant virus detection and isolation studies. PMID:24498379

  19. Waste Isolation Pilot Plant site environmental report for calendar year 1994

    SciTech Connect

    1995-06-01

    US Department of Energy (DOE) Order 5400.1 General Environmental Protection Program, requires each DOE facility that conducts significant environmental protection programs to prepare an Annual Site Environmental Report (ASER). The purpose of the ASER is to summarize environmental data in order to characterize site environmental management performance, to confirm compliance with environmental standards and requirements, and to highlight significant programs and efforts. This ASER not only documents the required data, it also documents new and continued monitoring and compliance activities during the 1994 calendar year. Data contained in this report are derived from those monitoring programs directed by the Waste Isolation Pilot Plant (WIPP) Environmental Monitoring Plan (EMP) (DOE/WIPP 94-024). The EMP defines a comprehensive set of parameters that must be monitored to detect potential impacts to the environment and to establish baseline measurements for future environmental evaluations. Surface water, groundwater, air, soil, and biotics are monitored for radiological and nonradiological activity levels. The baseline radiological surveillance program covers the broader geographic area that encompasses nearby ranches, villages, and cities. Nonradiological studies focus on the area immediately surrounding the WIPP site.

  20. Molecular Typing of Environmental and Clinical Strains of Vibrio vulnificus Isolated in the Northeastern USA

    PubMed Central

    Reynaud, Yann; Pitchford, Steven; De Decker, Sophie; Wikfors, Gary H.; Brown, Christopher L.

    2013-01-01

    Vibrio vulnificus is a ubiquitous marine bacterium that is responsible for infections and some seafood-related illnesses and deaths in the United States, mainly in individuals with compromised health status in the Gulf of Mexico region. Most phylogenetic studies focus on V. vulnificus strains isolated in the southern United States, but almost no genetic data are available on northeastern bacterial isolates of clinical or environmental origin. Our goal in this study was to examine the genetic diversity of environmental strains isolated from commercially-produced oysters and in clinical strains of known pathogenicity in northeastern United States. We conducted analyses of a total of eighty-three strains of V. vulnificus, including 18 clinical strains known to be pathogenic. A polyphasic, molecular-typing approach was carried out, based upon established biotypes, vcg, CPS, 16S rRNA types and three other genes possibly associated with virulence (arylsulfatase A, mtlABC, and nanA). An established Multi Locus Sequence Typing (MLST) method was also performed. Phylogenetic analyses of these markers and MLST results produced similar patterns of clustering of strains into two main lineages (we categorized as ‘LI’ and ‘LII’), with clinical and environmental strains clustering together in both lineages. Lineage LII was comprised primarily but not entirely of clinical bacterial isolates. Putative virulence markers were present in both clinical and environmental strains. These results suggest that some northeastern environmental strains of V. vulnificus are phylogenetically close to clinical strains and probably are capable of virulence. Further studies are necessary to assess the risk of human illness from consuming raw oysters harvested in the northeastern US. PMID:24386187

  1. Molecular typing of environmental and clinical strains of Vibrio vulnificus isolated in the northeastern USA.

    PubMed

    Reynaud, Yann; Pitchford, Steven; De Decker, Sophie; Wikfors, Gary H; Brown, Christopher L

    2013-01-01

    Vibrio vulnificus is a ubiquitous marine bacterium that is responsible for infections and some seafood-related illnesses and deaths in the United States, mainly in individuals with compromised health status in the Gulf of Mexico region. Most phylogenetic studies focus on V. vulnificus strains isolated in the southern United States, but almost no genetic data are available on northeastern bacterial isolates of clinical or environmental origin. Our goal in this study was to examine the genetic diversity of environmental strains isolated from commercially-produced oysters and in clinical strains of known pathogenicity in northeastern United States. We conducted analyses of a total of eighty-three strains of V. vulnificus, including 18 clinical strains known to be pathogenic. A polyphasic, molecular-typing approach was carried out, based upon established biotypes, vcg, CPS, 16S rRNA types and three other genes possibly associated with virulence (arylsulfatase A, mtlABC, and nanA). An established Multi Locus Sequence Typing (MLST) method was also performed. Phylogenetic analyses of these markers and MLST results produced similar patterns of clustering of strains into two main lineages (we categorized as 'LI' and 'LII'), with clinical and environmental strains clustering together in both lineages. Lineage LII was comprised primarily but not entirely of clinical bacterial isolates. Putative virulence markers were present in both clinical and environmental strains. These results suggest that some northeastern environmental strains of V. vulnificus are phylogenetically close to clinical strains and probably are capable of virulence. Further studies are necessary to assess the risk of human illness from consuming raw oysters harvested in the northeastern US.

  2. Waste Isolation Pilot Plant site environmental report for calendar year 1990

    SciTech Connect

    Not Available

    1990-01-01

    The US Department of Energy (DOE) Waste Isolation Pilot Plant (WIPP) Operational Environmental Monitoring Plan (OEMP) monitors a comprehensive set of parameters in order to detect any potential environmental impacts and establish baselines for future quantitative environmental impact evaluations. Surface water and groundwater, soil, and biotics are measured for background radiation. Nonradiological environmental monitoring activities include meteorological, air quality, soil properties, and the status of the local biological community. Ecological studies focus on the immediate area surrounding the site with emphasis on the salt storage pile, whereas baseline radiological surveillance covers a broader geographic area including nearby ranches, villages, and cities. Since the WIPP is still in a preoperational state, no waste has been received; therefore, certain elements required by Order DOE 5400.1 are not presented in this report. 15 figs. 19 tabs.

  3. Performance of the CLSI Carba NP and the Rosco Carb Screen Assays Using North American Carbapenemase-Producing Enterobacteriaceae and Pseudomonas aeruginosa Isolates

    PubMed Central

    Gallagher, Lauren C.; Roundtree, Sylvester S.; Lancaster, Diana P.; Rudin, Susan D.; Bard, Jennifer Dien; Roberts, Amity L.; Marshall, Steven H.; Bonomo, Robert A.

    2015-01-01

    This study compared the performance of the Carba NP assay, published by the Clinical and Laboratory Standards Institute, and the Rosco Rapid Carb Screen kit. Carba NP had superior sensitivity, but both assays required an increased inoculum to detect carbapenemase production in isolates with blaNDM, blaIMP, and blaOXA-48. PMID:26269624

  4. Performance of the CLSI Carba NP and the Rosco Carb Screen Assays Using North American Carbapenemase-Producing Enterobacteriaceae and Pseudomonas aeruginosa Isolates.

    PubMed

    Gallagher, Lauren C; Roundtree, Sylvester S; Lancaster, Diana P; Rudin, Susan D; Bard, Jennifer Dien; Roberts, Amity L; Marshall, Steven H; Bonomo, Robert A; Sullivan, Kaede V

    2015-10-01

    This study compared the performance of the Carba NP assay, published by the Clinical and Laboratory Standards Institute, and the Rosco Rapid Carb Screen kit. Carba NP had superior sensitivity, but both assays required an increased inoculum to detect carbapenemase production in isolates with blaNDM, blaIMP, and blaOXA-48.

  5. Pseudomonas Aeruginosa: Resistance to the Max

    PubMed Central

    Poole, Keith

    2011-01-01

    Pseudomonas aeruginosa is intrinsically resistant to a variety of antimicrobials and can develop resistance during anti-pseudomonal chemotherapy both of which compromise treatment of infections caused by this organism. Resistance to multiple classes of antimicrobials (multidrug resistance) in particular is increasingly common in P. aeruginosa, with a number of reports of pan-resistant isolates treatable with a single agent, colistin. Acquired resistance in this organism is multifactorial and attributable to chromosomal mutations and the acquisition of resistance genes via horizontal gene transfer. Mutational changes impacting resistance include upregulation of multidrug efflux systems to promote antimicrobial expulsion, derepression of ampC, AmpC alterations that expand the enzyme's substrate specificity (i.e., extended-spectrum AmpC), alterations to outer membrane permeability to limit antimicrobial entry and alterations to antimicrobial targets. Acquired mechanisms contributing to resistance in P. aeruginosa include β-lactamases, notably the extended-spectrum β-lactamases and the carbapenemases that hydrolyze most β-lactams, aminoglycoside-modifying enzymes, and 16S rRNA methylases that provide high-level pan-aminoglycoside resistance. The organism's propensity to grow in vivo as antimicrobial-tolerant biofilms and the occurrence of hypermutator strains that yield antimicrobial resistant mutants at higher frequency also compromise anti-pseudomonal chemotherapy. With limited therapeutic options and increasing resistance will the untreatable P. aeruginosa infection soon be upon us? PMID:21747788

  6. Biochemical Characteristics, Adhesion, and Cytotoxicity of Environmental and Clinical Isolates of Herbaspirillum spp.

    PubMed Central

    Marques, Ana C. Q.; Paludo, Katia S.; Dallagassa, Cibelle B.; Surek, Monica; Pedrosa, Fábio O.; Souza, Emanuel M.; Cruz, Leonardo M.; LiPuma, John J.; Zanata, Sílvio M.; Rego, Fabiane G. M.

    2014-01-01

    Herbaspirillum bacteria are best known as plant growth-promoting rhizobacteria but have also been recovered from clinical samples. Here, biochemical tests, matrix-assisted laser deionization–time of flight (MALDI-TOF) mass spectrometry, adherence, and cytotoxicity to eukaryotic cells were used to compare clinical and environmental isolates of Herbaspirillum spp. Discrete biochemical differences were observed between human and environmental strains. All strains adhered to HeLa cells at low densities, and cytotoxic effects were discrete, supporting the view that Herbaspirillum bacteria are opportunists with low virulence potential. PMID:25355763

  7. Antimicrobial resistance in Enterococcus spp. isolated from environmental samples in an area of intensive poultry production.

    PubMed

    Furtula, Vesna; Jackson, Charlene R; Farrell, Erin Gwenn; Barrett, John B; Hiott, Lari M; Chambers, Patricia A

    2013-03-12

    Enterococcus spp. from two poultry farms and proximate surface and ground water sites in an area of intensive poultry production were tested for resistance to 16 clinical antibiotics. Resistance patterns were compared to assess trends and possible correlations for specific antimicrobials and levels of resistance. Enterococci were detected at all 12 surface water sites and three of 28 ground water sites. Resistance to lincomycin, tetracycline, penicillin and ciprofloxacin in poultry litter isolates was high (80.3%, 65.3%, 61.1% and 49.6%, respectively). Resistance in the surface water to the same antibiotics was 87.1%, 24.1%, 7.6% and 12.9%, respectively. Overall, 86% of litter isolates, 58% of surface water isolates and 100% of ground water isolates were resistant to more than one antibiotic. Fifty-four different resistance patterns were recognised in isolates obtained from litter and environmental samples and several E. faecium and E. faecalis isolates from litter and environment samples shared the same resistance pattern. Multiple antibiotic resistant (MAR) indices calculated to assess health risks due to the presence of resistant enterococci suggested an increased presence of antibiotics in surface water, likely from poultry sources as no other wastewater contributions in the area were documented.

  8. MALDI-TOF Mass Spectrometry Discriminates Known Species and Marine Environmental Isolates of Pseudoalteromonas.

    PubMed

    Emami, Kaveh; Nelson, Andrew; Hack, Ethan; Zhang, Jinwei; Green, David H; Caldwell, Gary S; Mesbahi, Ehsan

    2016-01-01

    The genus Pseudoalteromonas constitutes an ecologically significant group of marine Gammaproteobacteria with potential biotechnological value as producers of bioactive compounds and of enzymes. Understanding their roles in the environment and bioprospecting for novel products depend on efficient ways of identifying environmental isolates. Matrix Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) biotyping has promise as a rapid and reliable method of identifying and distinguishing between different types of bacteria, but has had relatively limited application to marine bacteria and has not been applied systematically to Pseudoalteromonas. Therefore, we constructed a MALDI-TOF MS database of 31 known Pseudoalteromonas species, to which new isolates can be compared by MALDI-TOF biotyping. The ability of MALDI-TOF MS to distinguish between species was scrutinized by comparison with 16S rRNA gene sequencing. The patterns of similarity given by the two approaches were broadly but not completely consistent. In general, the resolution of MALDI-TOF MS was greater than that of 16S rRNA gene sequencing. The database was tested with 13 environmental Pseudoalteromonas isolates from UK waters. All of the test strains could be identified to genus level by MALDI-TOF MS biotyping, but most could not be definitely identified to species level. We conclude that several of these isolates, and possibly most, represent new species. Thus, further taxonomic investigation of Pseudoalteromonas is needed before MALDI-TOF MS biotyping can be used reliably for species identification. It is, however, a powerful tool for characterizing and distinguishing among environmental isolates and can make an important contribution to taxonomic studies.

  9. Fast and specific detection of Pseudomonas Aeruginosa from other pseudomonas species by PCR

    PubMed Central

    Jami Al-Ahmadi, G.; Zahmatkesh Roodsari, R.

    2016-01-01

    Summary Pseudomonas aeruginosa is an important life-threatening nosocomial pathogen that plays a prominent role in wound infections of burned patients. We designed this study to identify the isolates of P. aeruginosa recovered from burned patients at the genus and species level through primers targeting oprI and oprL genes, and analyzed their antimicrobial resistance pattern. Over a 2-month period, wound samples were taken from burned patients and plated on MacConkey agar. All suspected colonies were primarily screened for P. aeruginosa by a combination of phenotypic tests. Molecular identifications of colonies were done using specific primers for oprI and oprL genes. Bacterial isolates were recovered from burn wound infections. Based on phenotypical identification tests, 138 (34%) P. aeruginosa isolates were identified; whereas by molecular techniques, just 128 P. aeruginosa yielded amplicon of oprL gene using species-specific primers, verifying the identity of P. aeruginosa; the others yielded amplicon of oprI gene using genus-specific primers, confirming the identity of fluorescent pseudomonads. This study indicates that molecular detection of P. aeruginosa in burn patients employing the OprL gene target is a useful technique for the early and precise detection of P. aeruginosa. PCR detection should be carried out as well as phenotypic testing for the best aggressive antibiotic treatment of P. aeruginosa strains at an earlier stage. It also has significant benefits on clinical outcomes. PMID:28289359

  10. Application of oligonucleotide microarrays for bacterial source tracking of environmental Enterococcus sp. isolates.

    PubMed

    Indest, Karl J; Betts, Kelley; Furey, John S

    2005-04-01

    In an effort towards adapting new and defensible methods for assessing and managing the risk posed by microbial pollution, we evaluated the utility of oligonucleotide microarrays for bacterial source tracking (BST) of environmental Enterococcus sp. isolates derived from various host sources. Current bacterial source tracking approaches rely on various phenotypic and genotypic methods to identify sources of bacterial contamination resulting from point or non-point pollution. For this study Enterococcus sp. isolates originating from deer, bovine, gull, and human sources were examined using microarrays. Isolates were subjected to Box PCR amplification and the resulting amplification products labeled with Cy5. Fluorescent-labeled templates were hybridized to in-house constructed nonamer oligonucleotide microarrays consisting of 198 probes. Microarray hybridization profiles were obtained using the ArrayPro image analysis software. Principal Components Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were compared for their ability to visually cluster microarray hybridization profiles based on the environmental source from which the Enterococcus sp. isolates originated. The PCA was visually superior at separating origin-specific clusters, even for as few as 3 factors. A Soft Independent Modeling (SIM) classification confirmed the PCA, resulting in zero misclassifications using 5 factors for each class. The implication of these results for the application of random oligonucleotide microarrays for BST is that, given the reproducibility issues, factor-based variable selection such as in PCA and SIM greatly outperforms dendrogram-based similarity measures such as in HCA and K-Nearest Neighbor KNN.

  11. Application of Oligonucleotide Microarrays for Bacterial Source Tracking of Environmental Enterococcus sp. Isolates

    PubMed Central

    Indest, Karl J.; Betts, Kelley; Furey, John S.

    2005-01-01

    In an effort towards adapting new and defensible methods for assessing and managing the risk posed by microbial pollution, we evaluated the utility of oligonucleotide microarrays for bacterial source tracking (BST) of environmental Enterococcus sp. isolates derived from various host sources. Current bacterial source tracking approaches rely on various phenotypic and genotypic methods to identify sources of bacterial contamination resulting from point or non-point pollution. For this study Enterococcus sp. isolates originating from deer, bovine, gull, and human sources were examined using microarrays. Isolates were subjected to Box PCR amplification and the resulting amplification products labeled with Cy5. Fluorescent-labeled templates were hybridized to in-house constructed nonamer oligonucleotide microarrays consisting of 198 probes. Microarray hybridization profiles were obtained using the ArrayPro image analysis software. Principal Components Analysis (PCA) and Hierarchical Cluster Analysis (HCA) were compared for their ability to visually cluster microarray hybridization profiles based on the environmental source from which the Enterococcus sp. isolates originated. The PCA was visually superior at separating origin-specific clusters, even for as few as 3 factors. A Soft Independent Modeling (SIM) classification confirmed the PCA, resulting in zero misclassifications using 5 factors for each class. The implication of these results for the application of random oligonucleotide microarrays for BST is that, given the reproducibility issues, factor-based variable selection such as in PCA and SIM greatly outperforms dendrogram-based similarity measures such as in HCA and K-Nearest Neighbor KNN. PMID:16705816

  12. Pulsed-field gel electrophoresis and ribotype profiles of clinical and environmental Vibrio vulnificus isolates.

    PubMed Central

    Tamplin, M L; Jackson, J K; Buchrieser, C; Murphree, R L; Portier, K M; Gangar, V; Miller, L G; Kaspar, C W

    1996-01-01

    Vibrio vulnificus belongs to the autochthonous bacterial flora of warm estuarine waters. It can cause life-threatening extraintestinal disease in persons who have underlying illness and who consume raw shellfish or contact wounds with estuarine water. Currently, very little is known about genetic diversity within this species. In this report, we describe high-level variation in restriction fragment length polymorphism profiles among 53 clinical and 78 environmental isolates, as determined by pulsed-field gel electrophoresis. In contrast, ribotype profiles showed greater similarity. When combined ribotype profiles of clinical and environmental isolates were analyzed, four predominant clusters were observed. Interestingly, a low number (16%) of clinical isolates were found in cluster C, compared with clusters A, B, and D (range, 50 to 83%). In addition, 83% of all Hawaiian isolates were located in a single cluster, indicating a possible relationship between geography and genotype. We also report that spontaneous translucent colonial morphotypes were distinct by both restriction fragment length polymorphism and biochemical profiles, compared with opaque parent strains. PMID:8837412

  13. A new selective enrichment procedure for isolating Pasteurella multocida from avian and environmental samples

    USGS Publications Warehouse

    Moore, M.K.; Cicnjak-Chubbs, L.; Gates, R.J.

    1994-01-01

    A selective enrichment procedure, using two new selective media, was developed to isolate Pasteurella multocida from wild birds and environmental samples. These media were developed by testing 15 selective agents with six isolates of P. multocida from wild avian origin and seven other bacteria representing genera frequently found in environmental and avian samples. The resulting media—Pasteurella multocida selective enrichment broth and Pasteurella multocida selective agar—consisted of a blood agar medium at pH 10 containing gentamicin, potassium tellurite, and amphotericin B. Media were tested to determine: 1) selectivity when attempting isolation from pond water and avian carcasses, 2) sensitivity for detection of low numbers of P. multocida from pure and mixed cultures, 3) host range specificity of the media, and 4) performance compared with standard blood agar. With the new selective enrichment procedure, P. multocida was isolated from inoculated (60 organisms/ml) pond water 84% of the time, whereas when standard blood agar was used, the recovery rate was 0%.

  14. Genetic Diversity of Clinical and Environmental Strains of Salmonella enterica Serotype Weltevreden Isolated in Malaysia

    PubMed Central

    Thong, K. L.; Goh, Y. L.; Radu, S.; Noorzaleha, S.; Yasin, R.; Koh, Y. T.; Lim, V. K. E.; Rusul, G.; Puthucheary, S. D.

    2002-01-01

    The incidence of food-borne salmonellosis due to Salmonella enterica serotype Weltevreden is reported to be on the increase in Malaysia. The pulsed-field gel electrophoresis (PFGE) subtyping method was used to assess the extent of genetic diversity and clonality of Salmonella serotype Weltevreden strains from humans and the environment. PFGE of XbaI-digested chromosomal DNA from 95 strains of Salmonella serotype Weltevreden gave 39 distinct profiles with a wide range of Dice coefficients (0.27 to 1.00), indicating that PFGE is very discriminative and that multiple clones of Salmonella serotype Weltevreden exist among clinical and environmental isolates. Strains of one dominant pulsotype (pulsotype X1/X2) appeared to be endemic in this region, as they were consistently recovered from humans with salmonellosis between 1996 and 2001 and from raw vegetables. In addition, the sharing of similar PFGE profiles among isolates from humans, vegetables, and beef provides indirect evidence of the possible transmission of salmonellosis from contaminated raw vegetables and meat to humans. Furthermore, the recurrence of PFGE profile X21 among isolates found in samples of vegetables from one wet market indicated the persistence of this clone. The environment in the wet markets may represent a major source of cross-contamination of vegetables with Salmonella serotype Weltevreden. Antibiotic sensitivity tests showed that the clinical isolates of Salmonella serotype Weltevreden remained drug sensitive but that the vegetable isolates were resistant to at least two antibiotics. To the best of our knowledge, this is the first study to compare clinical and environmental isolates of Salmonella serotype Weltevreden in Malaysia. PMID:12089269

  15. Clinical utilization of genomics data produced by the international Pseudomonas aeruginosa consortium

    PubMed Central

    Freschi, Luca; Jeukens, Julie; Kukavica-Ibrulj, Irena; Boyle, Brian; Dupont, Marie-Josée; Laroche, Jérôme; Larose, Stéphane; Maaroufi, Halim; Fothergill, Joanne L.; Moore, Matthew; Winsor, Geoffrey L.; Aaron, Shawn D.; Barbeau, Jean; Bell, Scott C.; Burns, Jane L.; Camara, Miguel; Cantin, André; Charette, Steve J.; Dewar, Ken; Déziel, Éric; Grimwood, Keith; Hancock, Robert E. W.; Harrison, Joe J.; Heeb, Stephan; Jelsbak, Lars; Jia, Baofeng; Kenna, Dervla T.; Kidd, Timothy J.; Klockgether, Jens; Lam, Joseph S.; Lamont, Iain L.; Lewenza, Shawn; Loman, Nick; Malouin, François; Manos, Jim; McArthur, Andrew G.; McKeown, Josie; Milot, Julie; Naghra, Hardeep; Nguyen, Dao; Pereira, Sheldon K.; Perron, Gabriel G.; Pirnay, Jean-Paul; Rainey, Paul B.; Rousseau, Simon; Santos, Pedro M.; Stephenson, Anne; Taylor, Véronique; Turton, Jane F.; Waglechner, Nicholas; Williams, Paul; Thrane, Sandra W.; Wright, Gerard D.; Brinkman, Fiona S. L.; Tucker, Nicholas P.; Tümmler, Burkhard; Winstanley, Craig; Levesque, Roger C.

    2015-01-01

    The International Pseudomonas aeruginosa Consortium is sequencing over 1000 genomes and building an analysis pipeline for the study of Pseudomonas genome evolution, antibiotic resistance and virulence genes. Metadata, including genomic and phenotypic data for each isolate of the collection, are available through the International Pseudomonas Consortium Database (http://ipcd.ibis.ulaval.ca/). Here, we present our strategy and the results that emerged from the analysis of the first 389 genomes. With as yet unmatched resolution, our results confirm that P. aeruginosa strains can be divided into three major groups that are further divided into subgroups, some not previously reported in the literature. We also provide the first snapshot of P. aeruginosa strain diversity with respect to antibiotic resistance. Our approach will allow us to draw potential links between environmental strains and those implicated in human and animal infections, understand how patients become infected and how the infection evolves over time as well as identify prognostic markers for better evidence-based decisions on patient care. PMID:26483767

  16. Determinants for persistence of Pseudomonas aeruginosa in hospitals: interplay between resistance, virulence and biofilm formation.

    PubMed

    Kaiser, S J; Mutters, N T; DeRosa, A; Ewers, C; Frank, U; Günther, F

    2017-02-01

    Pseudomonas aeruginosa (Pa) is one of the major bacterial pathogens causing nosocomial infections. During the past few decades, multidrug-resistant (MDR) and extensively drug-resistant (XDR) lineages of Pa have emerged in hospital settings with increasing numbers. However, it remains unclear which determinants of Pa facilitated this spread. A total of 211 clinical XDR and 38 susceptible clinical Pa isolates (nonXDR), as well as 47 environmental isolates (EI), were collected at the Heidelberg University Hospital. We used RAPD PCR to identify genetic clusters. Carriage of carbapenamases (CPM) and virulence genes were analyzed by PCR, biofilm formation capacity was assessed, in vitro fitness was evaluated using competitive growth assays, and interaction with the host's immune system was analyzed using serum killing and neutrophil killing assays. XDR isolates showed significantly elevated biofilm formation (p < 0.05) and higher competitive fitness compared to nonXDR and EI isolates. Thirty percent (62/205) of the XDR isolates carried a CPM. Similarities in distribution of virulence factors, as well as biofilm formation properties, between CPM+ Pa isolates and EI and between CPM- and nonXDR isolates were detected. Molecular typing revealed two distinct genetic clusters within the XDR population, which were characterized by even higher biofilm formation. In contrast, XDR isolates were more susceptible to the immune response than nonXDR isolates. Our study provides evidence that the ability to form biofilms is an outstanding determinant for persistence and endemic spread of Pa in the hospital setting.

  17. Isolation and identification of Salmonella spp. in environmental water by molecular technology in Taiwan

    NASA Astrophysics Data System (ADS)

    Kuo, Chun Wei; Hao Huang, Kuan; Hsu, Bing Mu; Tsai, Hsien Lung; Tseng, Shao Feng; Shen, Tsung Yu; Kao, Po Min; Shen, Shu Min; Chen, Jung Sheng

    2013-04-01

    Salmonella spp. is one of the most important causal agents of waterborne diseases. The taxonomy of Salmonella is very complicated and its genus comprises more than 2,500 serotypes. The detection of Salmonella in environmental water samples by routines culture methods using selective media and characterization of suspicious colonies based on biochemical tests and serological assay are generally time consuming. To overcome this drawback, it is desirable to use effective method which provides a higher discrimination and more rapid identification about Salmonella in environmental water. The aim of this study is to investigate the occurrence of Salmonella using molecular technology and to identify the serovars of Salmonella isolates from 70 environmental water samples in Taiwan. The analytical procedures include membrane filtration, non-selective pre-enrichment, selective enrichment of Salmonella. After that, we isolated Salmonella strains by selective culture plates. Both selective enrichment and culture plates were detected by Polymerase Chain Reaction (PCR). Finally, the serovars of Salmonella were confirmed by using biochemical tests and serological assay. In this study, 15 water samples (21.4%) were identified as Salmonella by PCR. The positive water samples will further identify their serotypes by culture method. The presence of Salmonella in environmental water indicates the possibility of waterborne transmission in drinking watershed. Consequently, the authorities need to provide sufficient source protection and to maintain the system for disease prevention. Keywords: Salmonella spp., serological assay, PCR

  18. Differentiation of environmental aquatic bacterial isolates by MALDI-TOF MS.

    PubMed

    Popović, Natalija Topić; Kazazić, Snježana P; Strunjak-Perović, Ivančica; Čož-Rakovac, Rozelindra

    2017-01-01

    Identification of bacteria in aquatic and environmental applications, for monitoring purposes and research, for health assessments and therapy considerations of farmed and free-living aquatic organisms, still relies on conventional phenotypic and biochemical protocols. Although molecular techniques based on DNA amplification and sequencing are finding ways into diagnostic laboratories, they are time-consuming, costly and difficult in the case of multiplex assays. Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) is a rapid and accurate proteomic method reliable for identification of unknown bacteria to the genus and species level. Upon extension of databases, it will certainly find its position in environmental sciences. The paper presents an overview of the principle of the method, its effectiveness in comparison with conventional and molecular identification procedures, and applicability on environmental and aquatic isolates, discussing its advantages and shortcomings, as well as possible future implementations.

  19. Waste Isolation Pilot Plant annual site environmental report for calendar year 1992

    SciTech Connect

    Not Available

    1993-12-31

    The US Department of Energy (DOE) Waste Isolation Pilot Plant (WIPP) Operational Environmental Monitoring Plan (OEMP) defined a comprehensive set of parameters which are monitored to detect potential environmental impacts and establish baselines for future environmental evaluations. Surface water and groundwater, air, soil, and biotics are monitored for radioactivity levels. Nonradiological environmental monitoring activities include air, water quality, soil properties, meteorological measurements and determination of the status of the local biological community. Ecological studies focus on the immediate area surrounding the WIPP site with emphasis on the salt storage pile. The baseline radiological surveillance covers a broader geographic area including nearby ranches, villages, and cities. Since the WIPP is still in its preoperational phase (i.e., no waste has been received) certain operational requirements of DOE Orders 5400.1, 5400.5, and the Environmental Regulatory Guide for Radiological Effluent Monitoring and Environmental Surveillance (DOE/EH-0173T) are not relevant. Therefore, this report does not discuss items such as radionuclide emissions and effluents and subsequent doses to the public.

  20. [Evaluation of a hospital outbreak related to carbapenem-resistant Pseudomonas aeruginosa].

    PubMed

    Cekin, Yeşim; Karagöz, Alper; Kızılateş, Filiz; Cekin, Ayhan Hilmi; Oztoprak Çuvalcı, Nefise; Bülbüller, Nurullah; Durmaz, Rıza

    2013-10-01

    Pseudomonas aeruginosa is an important nosocomial pathogen that causes opportunistic infections and hospital outbreaks. During October 2012, carbapenem-resistant P.aeruginosa strains with similar antibiotic resistance patterns, were isolated from specimens sent from the intensive care and plastic surgery units in our hospital. Thus a hospital outbreak was suspected. The microbiology laboratory database was retrospectively searched and all strains of P.aeruginosa isolated during the four month period, starting with the initial carbapenem-resistant strain in August 2012, was evaluated as a hospital outbreak. The aim of this study was to define the outbreak by investigating the clonal relationship between the strains, to detect the potential environmental sources and to evaluate the period of the outbreak, risk factors and the efficiency of infection control measures. The study was conducted between August-November 2012. Twenty patients with carbapenem-resistant P.aeruginosa (CRPA) positive cultures were included in the study. The control group consisted of 22 patients with carbapenem-susceptible P.aeruginosa (CSPA) positive cultures. The clonal relationship between 26 CRPA strains was studied by pulsed-field gel electrophoresis (PFGE). The PFGE results indicated that CRPA strains in our hospital were not related to a single clone, however, there were four major clones composed of four to eight strains. Logistic regression analysis indicated that the risk increased 15.7 fold (95% CI: 1.19-207.76) by the use of carbapenem, 76.8 fold (95% CI: 2.03-2901.30) by surgical procedures and 0.787 fold (95% CI: 0.63-0.97) by the duration of hospital stay. Surveillance cultures from health-care personel and the environment performed in course of the outbreak, yielded no growth of a strain with the similar antibiotic resistance pattern. The spread of CRPA has been controlled by the use of effective precautionary measures, regressing the isolate number to 0-1 strain/month. Since

  1. ISOLATION OF Cryptococcus neoformans FROM ENVIRONMENTAL SAMPLES COLLECTED IN SOUTHEASTERN NIGERIA

    PubMed Central

    NWEZE, Emeka I.; KECHIA, Fred A.; DIBUA, Uju E.; EZE, Charles; ONOJA, Uwakwe S.

    2015-01-01

    SUMMARY Cryptococcosis caused by Cryptococcus neoformans is the second most common fungal opportunistic pathogen and a lifethreatening infection with serious clinical manifestations especially in HIV/AIDS and other immunocompromised patients. In Nigeria, HIV/AIDS infection has reached an alarming level. Despite this, information on the presence of this fungus in clinical and environmental samples is very scanty in Nigeria and many other parts of Africa. We set out to evaluate the presence of Cryptococcus neoformans or C. gattii in pigeon droppings obtained from Southeastern Nigeria. One hundred and seventy-seven samples of pigeon droppings from six sample types were collected. The area covered comprised of ten cities and other locations spanning across five States in Nigeria. Using established techniques, Cryptococcus neoformans was isolated from 39 of the 177 (22.0%) samples overall. No C. gattiiwas isolated. Most of the isolates (32.4%) were recovered from dovecotes (11 of 34) followed closely by samples taken from markets (31.8%; seven of 22) and least from the church (4.0%; one of 25). The highest isolation rate (38.9%) was found in samples from Enugu-Ezike(seven of 23) while the least came from Afikpoand the other locations each with 9.1% isolation rate. This is the first large-scale screening of Cryptococcus neoformans from pigeon droppings in Nigeria. The ecological and epidemiological significance of these findings are discussed. PMID:26422152

  2. Genetic Background of β-Lactamases in Enterobacteriaceae Isolates from Environmental Samples.

    PubMed

    de Oliveira, Daniele V; Nunes, Luciana S; Barth, Afonso Luís; Van Der Sand, Sueli T

    2017-04-04

    The prevalence of β-lactamase-producing Enterobacteriaceae has increased worldwide. Although antibiotic-resistant bacteria are usually associated with hospitals, there are a growing number of reports of resistant bacteria in other environments. Concern about resistant microorganisms outside the hospital setting highlights the need to investigate mechanisms of antibiotic resistance in isolates collected from the environment. The present study evaluated the resistance mechanism to β-lactam antibiotics in 40 isolates from hospital sewage and surface water from the Dilúvio Stream, Porto Alegre City, Southern Brazil. The multiplex PCR technique was used to detect several resistance genes of β-lactamases: extended-spectrum β-lactamases (ESBLs), carbapenemases, and β-lactamase AmpC. After genes, detection amplicons were sequenced to confirm their identification. The clonal relationship was established by DNA macrorestriction using the XbaI enzyme, followed by pulsed-field gel electrophoresis (PFGE). The results indicated that resistance genes were present in 85% of the isolates. The most prevalent genes encoded narrow-spectrum β-lactamase, such as TEM-1 and SHV-1 with 70% of the strains, followed by carbapenemase KPC and GES (45%), ESBL types SHV-5 and CTX-M-8 (27.5%), and AmpC (ACT-1/MIR-1) (2.5%). Twelve isolates contained only one resistance gene, 14 contained two, and eight isolates had three resistance genes. PFGE indicated a clonal relationship among K. pneumoniae isolates. It was not possible to establish a clonal relationship between Enterobacter sp. isolates. The results highlight the potential of these resistance genes to spread in the polluted environment and to present a health risk to communities. This report is the first description of these resistance genes present in environmental samples other than a hospital in the city of Porto Alegre/RS.

  3. Draft Genome Sequence of Pseudomonas aeruginosa Strain RB, a Bacterium Capable of Synthesizing Cadmium Selenide Nanoparticles.

    PubMed

    Ayano, Hiroyuki; Kuroda, Masashi; Soda, Satoshi; Ike, Michihiko

    2014-05-15

    Pseudomonas aeruginosa strain RB is a bacterium capable of synthesizing cadmium selenide (CdSe) nanoparticles and was isolated from a soil sample. Here, we present the draft genome sequence of P. aeruginosa strain RB. To the best of our knowledge, this is the first report of a draft genome of a CdSe-synthesizing bacterium.

  4. Risk assessment of Pseudomonas aeruginosa in water.

    PubMed

    Mena, Kristina D; Gerba, Charles P

    2009-01-01

    enhances its growth. The organism is usually found in whirlpools when the chlorine concentrations are low, but it has been isolated even in the presence of 3.00 ppm residual free chlorine (Price and Ahearn 1988). Many outbreaks of folliculitis and ear infections have been reportedly associated with the use of whirlpools and hot tubs that contain P. aeruginosa (Ratnam et al. 1986). Outbreaks have also been reported from exposure to P. aeruginosa in swimming pools and water slides. Although P. aeruginosa has a reputation for being resistant to disinfection, most studies show that it does not exhibit any marked resistance to the disinfectants used to treat drinking water such as chlorine, chloramines, ozone, or iodine. One author, however, did find it to be slightly more resistant to UV disinfection than most other bacteria (Wolfe 1990). Although much has been written about biofilms in the drinking water industry, very little has been reported regarding the role of P. aeruginosa in biofilms. Tap water appears to be a significant route of transmission in hospitals, from colonization of plumbing fixtures. It is still not clear if the colonization results from the water in the distribution system, or personnel use within the hospital. Infections and colonization can be significantly reduced by placement of filters on the water taps. The oral dose of P. aeruginosa required to establish colonization in a healthy subject is high (George et al. 1989a). During dose-response studies, even when subjects (mice or humans) were colonized via ingestion, there was no evidence of disease. P. aeruginosa administered by the aerosol route at levels of 10(7) cells did cause disease symptoms in mice, and was lethal in aerosolized doses of 10(9) cells. Aerosol dose-response studies have not been undertaken with human subjects. Human health risks associated with exposure to P. aeruginosa via drinking water ingestion were estimated using a four-step risk assessment approach. The risk of colonization

  5. Heterogeneity of Pseudomonas aeruginosa in Brazilian Cystic Fibrosis Patients

    PubMed Central

    Silbert, Suzane; Barth, Afonso Luis; Sader, Hélio S.

    2001-01-01

    The aim of this study was to assess the diversity and genomic variability of Pseudomonas aeruginosa isolates from cystic fibrosis (CF) patients being treated at a university hospital in Brazil. Ninety-seven isolates of P. aeruginosa from 43 CF patients were characterized by macrorestriction analysis of chromosomal DNA by pulsed-field gel electrophoresis (PFGE) and tested for susceptibility to 20 antimicrobial agents by broth microdilution. It was possible to evaluate single isolates from 20 patients and multiple isolates (two to seven) from 23 patients collected during a 22-month period. Among all of the unrelated patients, we detected only one pair of patients sharing a common strain. Among the 77 isolates from 23 patients who had multiple isolates analyzed, we identified 37 major types by PFGE, and five different colonization patterns were recognized. The isolates were susceptible to several antimicrobial agents, although consecutive isolates from the same patient may display differences in their susceptibilities. Mucoid isolates were more resistant (P < 0.001) than nonmucoid isolates to five antibiotics. Our results indicate that CF patients remain colonized by more than one strain of P. aeruginosa for long periods of time. In addition, the finding of several different genotypes in the same patient suggests that the colonizing strain may occasionally be replaced. PMID:11682517

  6. Early postweaning social isolation but not environmental enrichment modifies vermal Purkinje cell dendritic outgrowth in rats.

    PubMed

    Pascual, Rodrigo; Bustamante, Carlos

    2013-01-01

    In the present study, we analyzed the effects of enriched, social and isolated experiences on vermal Purkinje cell of the rat, together with anxiety-like behavior in the elevated-plus maze. Sprague-Dawley male rats were randomly submitted to either enriched, social, or isolated environments during the early postweaning period (postnatal days 22-32) and were then behaviorally evaluated in the elevated-plus maze and euthanized for histological analysis. Vermal Purkinje cells (sub-lobules VIa and VIb) were sampled, drawn under camera lucida and morphometrically assessed using the Sholl's concentric ring method. Data obtained indicate that environmental enrichment did not significantly modify the Purkinje cell dendritic branching. On the contrary, Purkinje cell of animals reared in social isolation exhibited a significant reduction in dendritic arborization, which was closely associated with anxiety-like behaviors. The data obtained indicate that, although environmental stimulation in normal animals does not produce significant changes in vermal Purkinje cell dendritic arborization, these cells are vulnerable to early stressful experiences, which is in close association with anxiety-like behaviors.

  7. Detection, selective isolation and characterisation of Dactylosporangium strains from diverse environmental samples.

    PubMed

    Kim, Byung-Yong; Kshetrimayum, Jenileima Devi; Goodfellow, Michael

    2011-12-01

    A culture-independent, nested PCR procedure based on genus-specific oligonucleotide primers detected the presence of members of the genus Dactylosporangium in 14 out of 21 diverse environmental samples. Clones generated from the 14 positive environmental samples formed distinct phyletic lines in the dactylosporangial 16S rRNA gene tree. Presumptive dactylosporangiae were isolated from 7 of these samples using a medium designed to be selective for members of the genus Dactylosporangium, namely Streptomyces Isolation Medium supplemented with gentamicin and antifungal antibiotics. One hundred and two out of 219 representative presumptive dactylosporangiae were considered as authentic members of the genus Dactylosporangium as they gave PCR amplification products using the genus-specific primers and had chemical features typical of dactylosporangiae. Representative of the Dactylosporangium isolates formed distinctive phyletic lines in the dactylosporangial 16S rRNA gene tree, contained the non-ribosomal peptide and type-I polyketide synthase genes and inhibited the growth of Bacillus subtilis, Kocuria rhizophila and Staphylococcus aureus strains. It is evident from these results that the genus Dactylosporangium is underspeciated, widely distributed in natural habitats and is a potentially rich source of novel secondary metabolites.

  8. Molecular characterization of environmental Cryptococcus neoformans VNII isolates in Jos, Plateau State, Nigeria.

    PubMed

    Nnadi, N E; Enweani, I B; Cogliati, M; Ayanbimpe, G M; Okolo, M O; Kim, E; Sabitu, M Z; Criseo, G; Romeo, O; Scordino, F

    2016-12-01

    Cryptococcus neoformans and Cryptococcus gattii are encapsulated yeasts able to cause fatal neurological infections in both human and other mammals. Cryptococcosis is the most common fungal infection of the central nervous system and has a huge burden in sub-Saharan Africa and South East Asia. Bird excreta are considered an environmental reservoir for C. neoformans in urban areas, therefore a study aimed at isolating and characterizing this yeast is important in disease management. In this study, one hundred samples of pigeon droppings were collected in Jos, Plateau State, Nigeria. C. neoformans was isolated from three samples and initially identified using standard phenotypic and biochemical tests. Molecular analysis revealed that all three isolates belonged to C. neoformans genotype VNII, mating type α and were assigned to the sequence type ST43 by multilocus sequence typing analysis. This study reports, for the first time, the molecular characterization of C. neoformans in Nigeria, where little is still known about the environmental distribution of the genotypes, serotypes and mating types of this important human pathogen.

  9. Detection of benzalkonium chloride resistance in community environmental isolates of staphylococci.

    PubMed

    He, Gui-Xin; Landry, Michael; Chen, Huizhong; Thorpe, Conner; Walsh, Dennis; Varela, Manuel F; Pan, Hongmiao

    2014-05-01

    We isolated a total of 653 strains from 64 community environmental samples in Massachusetts, USA. Among these isolates, 9.65 % (63 strains) were benzalkonium chloride (BC)-resistant staphylococci. All BC-resistant strains were collected from surfaces upon which antibacterial wipes or antibacterial sprays containing 0.02-0.12 % BC had frequently been used in the fitness centres. However, isolates from surfaces upon which antibacterial wipes or antibacterial sprays had not been used were all sensitive to BC. All BC-resistant strains were also resistant to erythromycin, penicillin and ampicillin. In addition, 51 strains showed resistance to cetyltrimethylammonium bromide (CTAB), 15 strains showed resistance to chloramphenicol, 12 strains showed resistance to ciprofloxacin and four strains showed resistance to meticillin. Resistance gene analysis demonstrated that 41 strains contained qacA/B, 30 strains had qacC, 25 strains contained qacG, 16 strains had qacH and eight strains contained qacJ. These data indicate that application of BC is associated with environmental staphylococcal antimicrobial resistance.

  10. [Antibacterial activities of combination uses of cefpirome with various antibiotics in vitro against clinically isolated glucose non-fermentative gram-negative rods: part 1. the results against Pseudomonas aeruginosa].

    PubMed

    Suzuki, Y; Koguchi, M; Fukayama, S; Ishihara, R; Oda, S; Deguchi, K

    1996-01-01

    In order to evaluate antibacterial activities of combination uses of cefpirome (CPR) and various antibiotics in vitro, minimum inhibitory concentrations (MICs) of CPR alone and combinations of CPR+other drugs against freshly isolated clinical strains of Pseudomonas aeruginosa. The results are summarized as follows; 1. Combined effects of CPR+beta-lactams, piperacillin (PIPC), aztreonam (AZT), imipenem (IPM) showed wider antibacterial spectra and stronger antibacterial activities than CPR alone with drugs concentrations of CPR and other drugs at sub-MIC levels. At concentrations of sub-MIC levels, antibacterial effects of CPR+PIPC and CPR+AZT combination were strong but CPR+IPM was weaker than those of the former two combinations. It appeared that stronger effects were demonstrated by some combinations against strains that were susceptible to both drugs of combination, but little additive effects were shown against strains that were resistant to both drugs. Antibacterial effect of CPR+fosfomycin combination was the same as those of CPR+PIPC and CPR+AZT combinations. 2. Combined effects of CPR+aminoglycosides (AGs), gentamicin, tobramycin, amikacin showed wider antibacterial spectra and stronger antibacterial activities at sub-MIC levels of CPR or ATs. The effect against CPR-resistant strains was same. But the combined effect was weak against AGs-resistant strains. 3. Effectiveness of combinations of CPR+beta-lactams and CPR+AGs depended on drug susceptibilities of strains tested. We cannot estimate effects of those combinations without investigating drug susceptibility of bacteria being tested. 4. In none of the combinations tested, antagonism was observed.

  11. Strong incidence of Pseudomonas aeruginosa on bacterial rrs and ITS genetic structures of cystic fibrosis sputa

    PubMed Central

    Pages-Monteiro, Laurence; Marti, Romain; Commun, Carine; Alliot, Nolwenn; Bardel, Claire; Meugnier, Helene; Perouse-de-Montclos, Michele; Reix, Philippe; Durieu, Isabelle; Durupt, Stephane; Vandenesch, Francois; Freney, Jean; Cournoyer, Benoit; Doleans-Jordheim, Anne

    2017-01-01

    Cystic fibrosis (CF) lungs harbor a complex community of interacting microbes, including pathogens like Pseudomonas aeruginosa. Meta-taxogenomic analysis based on V5-V6 rrs PCR products of 52 P. aeruginosa-positive (Pp) and 52 P. aeruginosa-negative (Pn) pooled DNA extracts from CF sputa suggested positive associations between P. aeruginosa and Stenotrophomonas and Prevotella, but negative ones with Haemophilus, Neisseria and Burkholderia. Internal Transcribed Spacer analyses (RISA) from individual DNA extracts identified three significant genetic structures within the CF cohorts, and indicated an impact of P. aeruginosa. RISA clusters Ip and IIIp contained CF sputa with a P. aeruginosa prevalence above 93%, and of 24.2% in cluster IIp. Clusters Ip and IIIp showed lower RISA genetic diversity and richness than IIp. Highly similar cluster IIp RISA profiles were obtained from two patients harboring isolates of a same P. aeruginosa clone, suggesting convergent evolution in the structure of their microbiota. CF patients of cluster IIp had received significantly less antibiotics than patients of clusters Ip and IIIp but harbored the most resistant P. aeruginosa strains. Patients of cluster IIIp were older than those of Ip. The effects of P. aeruginosa on the RISA structures could not be fully dissociated from the above two confounding factors but several trends in these datasets support the conclusion of a strong incidence of P. aeruginosa on the genetic structure of CF lung microbiota. PMID:28282386

  12. Influence of Pseudomonas Aeruginosa on Exacerbation in Patients with Bronchiectasis

    PubMed Central

    Chawla, Kiran; Vishwanath, Shashidhar; Manu, Mohan K; Lazer, Bernaitis

    2015-01-01

    Background: A majority of the studies done on the western population have shown that Pseudomonas aeruginosa causes many severe infections in patients with bronchiectasis as compared to other pathogens. There is scarcity of similar data from the Asian population. Materials and Methods: A prospective study was undertaken to identify the various pathogens isolated from the respiratory samples of 117 patients with bronchiectasis from south India and to compare the clinicomicrobiological profile of infections caused by P. aeruginosa and other respiratory pathogens. Results: The respiratory pathogens were isolated from 63 (53.8%) patients. P. aeruginosa was the most common isolate (46.0%) followed by Klebsiella pneumoniae (14.3%) and other pathogenic bacteria. Patients included in the P. aeruginosa group had a higher number of exacerbations (p: 0.008), greater number of hospital admissions (p: 0.007), a prolonged hospital stay (p: 0.03), and poor lung function, compared to the patients infected with the non-Pseudomonas group. Conclusion: It is necessary to investigate the etiology of respiratory tract infections among bronchiectasis patients followed by the prompt management of cases diagnosed with P. aeruginosa infections, so as to lower the morbidity and have a better prognosis. PMID:25722615

  13. [Resistance to antibiotics in Pseudomonas aeruginosa in Colombian hospitals].

    PubMed

    Villa, Lina M; Cortés, Jorge A; Leal, Aura L; Meneses, Andrés; Meléndez, Martha P

    2013-12-01

    Pseudomonas aeruginosa infections cause high morbidity and mortality. We performed a descriptive analysis of the rates of antibiotic resistance in isolates of P. aeruginosa in 33 hospitals enrolled in a surveillance network in Colombia. The study was conducted between January 2005 and December 2009 .9905 isolates of P. aeruginosa were identified, (4.9% of all strains). In intensive care units (ICU) P. aeruginosa showed an overall resistance to aztreonam, cefepime , ceftazidime, imipenem, meropenem , and piperacillin / tazobactam of 31.8% , 23.9% , 24.8%, 22.5%, 20.3% and 22.3%, respectively. Resistance rates increased for piperacillin/tazobactam, cefepime, and imipenem; remained unchanged for meropenem; and decreased for aminoglycosides, quinolones and ceftazidime. Resistance to one, two and three or more families of antibiotics was found in 17%, 12.5%, and 32.1%, respectively. In samples collected from the wards, the resistance rate was lower but usually over 10%. Antibiotic resistance in P. aeruginosa isolates in hospitalized patients and particularly in those admitted to ICUs in Colombia is high.

  14. Pseudomonas aeruginosa on vinyl-canvas inflatables and foam teaching aids in swimming pools.

    PubMed

    Schets, F M; van den Berg, H H J L; Baan, R; Lynch, G; de Roda Husman, A M

    2014-12-01

    Swimming pool-related Pseudomonas aeruginosa infections mainly result in folliculitis and otitis externa. P. aeruginosa forms biofilms on surfaces in the swimming pool environment. The presence of P. aeruginosa on inflatables and foam teaching aids in 24 public swimming pools in the Netherlands was studied. Samples (n = 230) were taken from 175 objects and analysed for P. aeruginosa by culture. Isolated P. aeruginosa were tested for antibiotic resistance by disk diffusion. P. aeruginosa was detected in 63 samples (27%), from 47 objects (27%) in 19 (79%) swimming pools. More vinyl-canvas objects (44%) than foam objects (20%) were contaminated, as were wet objects (43%) compared to dry objects (13%). Concentrations were variable, and on average higher on vinyl-canvas than on foam objects. Forty of 193 (21%) P. aeruginosa isolates from 11 different objects were (intermediate) resistant to one or more of 12 clinically relevant antibiotics, mostly to imipenem and aztreonam. The immediate risk of a P. aeruginosa infection from exposure to swimming pool objects seems limited, but the presence of P. aeruginosa on pool objects is unwanted and requires attention of pool managers and responsible authorities. Strict drying and cleaning policies are needed for infrequently used vinyl-canvas objects.

  15. Environmental Isolation of Circulating Vaccine-Derived Poliovirus After Interruption of Wild Poliovirus Transmission - Nigeria, 2016.

    PubMed

    Etsano, Andrew; Damisa, Eunice; Shuaib, Faisal; Nganda, Gatei Wa; Enemaku, Ogu; Usman, Samuel; Adeniji, Adekunle; Jorba, Jaume; Iber, Jane; Ohuabunwo, Chima; Nnadi, Chimeremma; Wiesen, Eric

    2016-08-05

    In September 2015, more than 1 year after reporting its last wild poliovirus (WPV) case in July 2014 (1), Nigeria was removed from the list of countries with endemic poliovirus transmission,* leaving Afghanistan and Pakistan as the only remaining countries with endemic WPV. However, on April 29, 2016, a laboratory-confirmed, circulating vaccine-derived poliovirus type 2 (cVDPV2) isolate was reported from an environmental sample collected in March from a sewage effluent site in Maiduguri Municipal Council, Borno State, a security-compromised area in northeastern Nigeria. VDPVs are genetic variants of the vaccine viruses with the potential to cause paralysis and can circulate in areas with low population immunity. The Nigeria National Polio Emergency Operations Center initiated emergency response activities, including administration of at least 2 doses of oral poliovirus vaccine (OPV) to all children aged <5 years through mass campaigns; retroactive searches for missed cases of acute flaccid paralysis (AFP), and enhanced environmental surveillance. Approximately 1 million children were vaccinated in the first OPV round. Thirteen previously unreported AFP cases were identified. Enhanced environmental surveillance has not resulted in detection of additional VDPV isolates. The detection of persistent circulation of VDPV2 in Borno State highlights the low population immunity, surveillance limitations, and risk for international spread of cVDPVs associated with insurgency-related insecurity. Increasing vaccination coverage with additional targeted supplemental immunization activities and reestablishment of effective routine immunization activities in newly secured and difficult-to-reach areas in Borno is urgently needed.

  16. Environmental Free-Living Amoebae Isolated from Soil in Khon Kaen, Thailand, Antagonize Burkholderia pseudomallei

    PubMed Central

    Noinarin, Parumon; Chareonsudjai, Pisit; Wangsomnuk, Pinich; Wongratanacheewin, Surasak

    2016-01-01

    Presence of Burkholderia pseudomallei in soil and water is correlated with endemicity of melioidosis in Southeast Asia and northern Australia. Several biological and physico-chemical factors have been shown to influence persistence of B. pseudomallei in the environment of endemic areas. This study was the first to evaluate the interaction of B. pseudomallei with soil amoebae isolated from B. pseudomallei-positive soil site in Khon Kaen, Thailand. Four species of amoebae, Paravahlkampfia ustiana, Acanthamoeba sp., Naegleria pagei, and isolate A-ST39-E1, were isolated, cultured and identified based on morphology, movement and 18S rRNA gene sequence. Co-cultivation combined with a kanamycin-protection assay of B. pseudomallei with these amoebae at MOI 20 at 30°C were evaluated during 0–6 h using the plate count technique on Ashdown’s agar. The fate of intracellular B. pseudomallei in these amoebae was also monitored by confocal laser scanning microscopy (CLSM) observation of the CellTracker™ Orange-B. pseudomallei stained cells. The results demonstrated the ability of P. ustiana, Acanthamoeba sp. and isolate A-ST39-E1 to graze B. pseudomallei. However, the number of internalized B. pseudomallei substantially decreased and the bacterial cells disappeared during the observation period, suggesting they had been digested. We found that B. pseudomallei promoted the growth of Acanthamoeba sp. and isolate A-ST39-E1 in co-cultures at MOI 100 at 30°C, 24 h. These findings indicated that P. ustiana, Acanthamoeba sp. and isolate A-ST39-E1 may prey upon B. pseudomallei rather than representing potential environmental reservoirs in which the bacteria can persist. PMID:27898739

  17. Genotypic characterization of environmental isolates of Cryptococcus gattii from Puerto Rico.

    PubMed

    Loperena-Alvarez, Yaliz; Ren, Ping; Li, Xiaojiang; Schoonmaker-Bopp, Dianna J; Bopp, D J; Ruiz, Alejandro; Chaturvedi, Vishnu; Rios-Velazquez, Carlos

    2010-10-01

    Cryptococcus neoformans and Cryptococcus gattii are found in distinct environments with some overlap around different parts of the world. However, no systematic surveys of these two pathogens have been reported from Puerto Rico, a tropical island uniquely situated between mainland USA and countries in South America. We carried out an exhaustive environmental survey in southwestern Puerto Rico for pathogenic Cryptococcus species. Twenty-two presumptive isolates of C. gattii from cacti and tree detritus were characterized in detail by physiological and molecular methods and seventeen strains were confirmed as C. gattii. Cryptococcus gattii isolates were haploid and majority of them were MATa [corrected] strains. Sixteen out of seventeen C. gattii isolates belonged to VGII/AFLP6 genotype while one isolate was a VGIV/AFLP7 genotype. The results are significant as Puerto Rico strains are distinct from VGIII/AFLP5 strains reported from Southern California, but similar to C. gattii VGII/AFLP6 molecular type implicated in recent outbreaks of cryptococcosis in Pacific Northwest and British Columbia, Canada, but different in its M13 fingerprinting, and a common genotype in South America.

  18. Occurrence of an Environmental Acinetobacter baumannii Strain Similar to a Clinical Isolate in Paleosol from Croatia

    PubMed Central

    Durn, Goran; Goic-Barisic, Ivana; Kovacic, Ana

    2014-01-01

    Over the past decade, bacteria of the genus Acinetobacter have emerged as a leading cause of hospital-acquired infections. Outbreaks of Acinetobacter infections are considered to be caused exclusively by contamination and transmission in hospital environments. The natural habitats of clinically important multiresistant Acinetobacter spp. remain to be defined. In this paper, we report an incidental finding of a viable multidrug-resistant strain of Acinetobacter baumannii, related to clinical isolates, in acid paleosol from Croatia. The environmental isolate of A. baumannii showed 87% similarity to a clinical isolate originating from a hospital in this geographic area and was resistant to gentamicin, trimethoprim-sulfamethoxazole, ciprofloxacin, and levofloxacin. In paleosol, the isolate was able to survive a low pH (3.37), desiccation, and a high temperature (50°C). The probable source of A. baumannii in paleosol is illegally disposed waste of external origin situated in the abandoned quarry near the sampling site. The bacteria could have been leached from waste by storm water and thus infiltrated the paleosol. PMID:24584245

  19. Different growth rates in amoeba of genotypically related environmental and clinical Legionella pneumophila strains isolated from a thermal spa.

    PubMed Central

    Molmeret, M.; Jarraud, S.; Mori, J. P.; Pernin, P.; Forey, F.; Reyrolle, M.; Vandenesch, F.; Etienne, J.; Farge, P.

    2001-01-01

    Two cases of legionellosis occurring 3 years apart were acquired in the same French thermal spa and were apparently due to the same strain of Legionella pneumophila serogroup 1, as shown by genomic macrorestriction analysis. Minor differences between the two isolates were found by random amplification PCR profiling which showed an additional band with one of the isolates. Analysis of 107 L. pneumophila strains isolated from the spa waters by genome macrorestriction failed to identify the infective strain, but a closely related L. pneumophila serogroup 3 strain differing from the clinical isolates by only one band was found. To determine if the clinical L. pneumophila serogroup 1 isolates was better adapted for intracellular multiplication than related serogroup 3 environmental isolates, the growth kinetics of six isolates were determined in co-culture with Acanthamoeba lenticulata. One clinical isolate failed to grow within amoeba, while the other clinical isolate yielded the highest increase in bacterial cell count per amoeba (1,200%) and the environmental isolates gave intermediate values. Genetic analysis of L. pneumophila isolates by DNA macrorestriction does not therefore appear to reflect their growth kinetics within amoeba, and is not sufficiently discriminatory to identify potentially virulent strains. PMID:11349974

  20. Different growth rates in amoeba of genotypically related environmental and clinical Legionella pneumophila strains isolated from a thermal spa.

    PubMed

    Molmeret, M; Jarraud, S; Mori, J P; Pernin, P; Forey, F; Reyrolle, M; Vandenesch, F; Etienne, J; Farge, P

    2001-04-01

    Two cases of legionellosis occurring 3 years apart were acquired in the same French thermal spa and were apparently due to the same strain of Legionella pneumophila serogroup 1, as shown by genomic macrorestriction analysis. Minor differences between the two isolates were found by random amplification PCR profiling which showed an additional band with one of the isolates. Analysis of 107 L. pneumophila strains isolated from the spa waters by genome macrorestriction failed to identify the infective strain, but a closely related L. pneumophila serogroup 3 strain differing from the clinical isolates by only one band was found. To determine if the clinical L. pneumophila serogroup 1 isolates was better adapted for intracellular multiplication than related serogroup 3 environmental isolates, the growth kinetics of six isolates were determined in co-culture with Acanthamoeba lenticulata. One clinical isolate failed to grow within amoeba, while the other clinical isolate yielded the highest increase in bacterial cell count per amoeba (1,200%) and the environmental isolates gave intermediate values. Genetic analysis of L. pneumophila isolates by DNA macrorestriction does not therefore appear to reflect their growth kinetics within amoeba, and is not sufficiently discriminatory to identify potentially virulent strains.

  1. Evidence for isolated evolution of deep-sea ciliate communities through geological separation and environmental selection

    PubMed Central

    2013-01-01

    Background Deep hypersaline anoxic basins (DHABs) are isolated habitats at the bottom of the eastern Mediterranean Sea, which originate from the ancient dissolution of Messinian evaporites. The different basins have recruited their original biota from the same source, but their geological evolution eventually constituted sharp environmental barriers, restricting genetic exchange between the individual basins. Therefore, DHABs are unique model systems to assess the effect of geological events and environmental conditions on the evolution and diversification of protistan plankton. Here, we examine evidence for isolated evolution of unicellular eukaryote protistan plankton communities driven by geological separation and environmental selection. We specifically focused on ciliated protists as a major component of protistan DHAB plankton by pyrosequencing the hypervariable V4 fragment of the small subunit ribosomal RNA. Geospatial distributions and responses of marine ciliates to differential hydrochemistries suggest strong physical and chemical barriers to dispersal that influence the evolution of this plankton group. Results Ciliate communities in the brines of four investigated DHABs are distinctively different from ciliate communities in the interfaces (haloclines) immediately above the brines. While the interface ciliate communities from different sites are relatively similar to each other, the brine ciliate communities are significantly different between sites. We found no distance-decay relationship, and canonical correspondence analyses identified oxygen and sodium as most important hydrochemical parameters explaining the partitioning of diversity between interface and brine ciliate communities. However, none of the analyzed hydrochemical parameters explained the significant differences between brine ciliate communities in different basins. Conclusions Our data indicate a frequent genetic exchange in the deep-sea water above the brines. The “isolated island

  2. Waste Isolation Pilot Plant disposal phase supplemental environmental impact statement. Implementation plan

    SciTech Connect

    1996-05-01

    The Implementation Plan for the Waste Isolation Pilot Plant Disposal Phase Supplemental Environmental Impact Statement (SEIS-II) has two primary purposes: (1) To report on the results of the scoping process (2) To provide guidance for preparing SEIS-II SEIS-II will be the National Environmental Policy Act (NEPA) review for WIPP`s disposal phase. Chapter 1 of this plan provides background on WIPP and this NEPA review. Chapter 2 describes the purpose and need for action by the Department of Energy (hereafter DOE or the Department), as well as a description of the Proposed Action and alternatives being considered. Chapter 3 describes the work plan, including the schedule, responsibilities, and planned consultations with other agencies and organizations. Chapter 4 describes the scoping process, presents major issues identified during the scoping process, and briefly indicates how issues will be addressed in SEIS-II.

  3. Environmental thermoluminescent dosimetry measurements at the WIPP (Waste Isolation Pilot Plant) Site, 1976-1985

    SciTech Connect

    Thompson, D.J.

    1988-02-01

    In 1975, the US Energy Research and Development Administration began evaluating a site in southeastern New Mexico for the possible construction and operation of a Waste Isolation Pilot Plant. The purpose of the facility was to test and demonstrate the operations and technical principles of a permanent repository in bedded salt for ERDA-generated transuranic radioactive waste. An extensive preoperational environmental study program to document the region's meterorology, geology, hydrology, flora and fauna, existing air and water quality, and background radiation was undertaken by Sandia National Laboratories. The purpose of this document is to report the final results of environmental thermoluminescent dosimeter measurements performed from January 1976 through December 1985. The final results were obtained by reevaluating the quarterly raw data using a uniform analysis procedure. 6 refs., 4 figs., 2 tabs.

  4. A network biology approach to denitrification in Pseudomonas aeruginosa

    DOE PAGES

    Arat, Seda; Bullerjahn, George S.; Laubenbacher, Reinhard

    2015-02-23

    Pseudomonas aeruginosa is a metabolically flexible member of the Gammaproteobacteria. Under anaerobic conditions and the presence of nitrate, P. aeruginosa can perform (complete) denitrification, a respiratory process of dissimilatory nitrate reduction to nitrogen gas via nitrite (NO₂), nitric oxide (NO) and nitrous oxide (N₂O). This study focuses on understanding the influence of environmental conditions on bacterial denitrification performance, using a mathematical model of a metabolic network in P. aeruginosa. To our knowledge, this is the first mathematical model of denitrification for this bacterium. Analysis of the long-term behavior of the network under changing concentration levels of oxygen (O₂), nitrate (NO₃),more » and phosphate (PO₄) suggests that PO₄ concentration strongly affects denitrification performance. The model provides three predictions on denitrification activity of P. aeruginosa under various environmental conditions, and these predictions are either experimentally validated or supported by pertinent biological literature. One motivation for this study is to capture the effect of PO₄ on a denitrification metabolic network of P. aeruginosa in order to shed light on mechanisms for greenhouse gas N₂O accumulation during seasonal oxygen depletion in aquatic environments such as Lake Erie (Laurentian Great Lakes, USA). Simulating the microbial production of greenhouse gases in anaerobic aquatic systems such as Lake Erie allows a deeper understanding of the contributing environmental effects that will inform studies on, and remediation strategies for, other hypoxic sites worldwide.« less

  5. Increased Isolation Frequency of Toxigenic Vibrio cholerae O1 from Environmental Monitoring Sites in Haiti

    PubMed Central

    Alam, Meer T.; Weppelmann, Thomas A.; Longini, Ira; De Rochars, Valery Madsen Beau; Morris, John Glenn; Ali, Afsar

    2015-01-01

    Since the identification of the first cholera case in 2010, the disease has spread in epidemic form throughout the island nation of Haiti; as of 2014, about 700,000 cholera cases have been reported, with over 8,000 deaths. While case numbers have declined, the more fundamental question of whether the causative bacterium, Vibrio cholerae has established an environmental reservoir in the surface waters of Haiti remains to be elucidated. In a previous study conducted between April 2012 and March 2013, we reported the isolation of toxigenic V. cholerae O1 from surface waters in the Ouest Department. After a second year of surveillance (April 2013 to March 2014) using identical methodology, we observed a more than five-fold increase in the number of water samples containing culturable V. cholerae O1 compared to the previous year (1.7% vs 8.6%), with double the number of sites having at least one positive sample (58% vs 20%). Both seasonal water temperatures and precipitation were significantly related to the frequency of isolation. Our data suggest that toxigenic V. cholerae O1 are becoming more common in surface waters in Haiti; while the basis for this increase is uncertain, our findings raise concerns that environmental reservoirs are being established. PMID:25853552

  6. Increased isolation frequency of toxigenic Vibrio cholerae O1 from environmental monitoring sites in Haiti.

    PubMed

    Alam, Meer T; Weppelmann, Thomas A; Longini, Ira; De Rochars, Valery Madsen Beau; Morris, John Glenn; Ali, Afsar

    2015-01-01

    Since the identification of the first cholera case in 2010, the disease has spread in epidemic form throughout the island nation of Haiti; as of 2014, about 700,000 cholera cases have been reported, with over 8,000 deaths. While case numbers have declined, the more fundamental question of whether the causative bacterium, Vibrio cholerae has established an environmental reservoir in the surface waters of Haiti remains to be elucidated. In a previous study conducted between April 2012 and March 2013, we reported the isolation of toxigenic V. cholerae O1 from surface waters in the Ouest Department. After a second year of surveillance (April 2013 to March 2014) using identical methodology, we observed a more than five-fold increase in the number of water samples containing culturable V. cholerae O1 compared to the previous year (1.7% vs 8.6%), with double the number of sites having at least one positive sample (58% vs 20%). Both seasonal water temperatures and precipitation were significantly related to the frequency of isolation. Our data suggest that toxigenic V. cholerae O1 are becoming more common in surface waters in Haiti; while the basis for this increase is uncertain, our findings raise concerns that environmental reservoirs are being established.

  7. Isolation and identification of Arcobacter species from environmental and drinking water samples.

    PubMed

    Talay, Funda; Molva, Celenk; Atabay, Halil Ibrahim

    2016-11-01

    Water plays an important role in the transmission of Arcobacter spp. to animals and humans. The aim of this study was to isolate and characterize Arcobacter spp. from 115 different water samples (66 sewage, 25 rivers, 16 spring water, and 8 drinking water) in Izmir, Turkey. In total, 41 samples (35.7 %) were found positive for Arcobacter spp. by the genus-specific PCR. Arcobacter butzleri was detected in 39 out of 115 samples (33.9 %) including 24 sewage, 13 rivers, and 2 spring water. The remaining Arcobacter spp. (n = 2) isolates could not be identified by m-PCR and 16S rRNA gene sequencing. Based on the phenotypic characterization, most of the Arcobacter species (87.8 %) indicated weak catalase activity. In addition, there were differences in phenotypic patterns among isolated species during growth at 37 °C under microaerobic and aerobic conditions, in the presence of 2 % (39/41) and 3.5 % (32/41) NaCl and 0.04 % TTC (39/41) and on MacConkey agar (38/41). The results of this study indicated that environmental water samples are common sources for Arcobacter spp. Therefore, effective control measures should be taken to protect human health.

  8. Physiological, morphological, and immunochemical parameters used for the characterization of clinical and environmental isolates of Acanthamoeba.

    PubMed

    Becker-Finco, A; Costa, A O; Silva, S K; Ramada, J S; Furst, C; Stinghen, A E; De Figueiredo, B C; De Moura, J; Alvarenga, L M

    2013-03-01

    The factors that characterize Acanthamoeba strains as harmless or potentially pathogenic have not been elucidated. Analysing the in vitro and in vivo parameters of Acanthamoeba samples, including heat tolerance at temperatures close to that of the human body, cytopathic effects, and their ability to cause infections in animals, has been proposed to identify their pathogenic potential. Another promising criterion for differentiating strains is the analysis of their biochemical and immunochemical properties. In this study, a comparative evaluation between clinical and environmental Acanthamoeba isolates was performed on the basis of physiological, morphological, and immunochemical criteria. Crude antigens were used to characterize the protein profiles by electrophoresis and immunize mice to produce polyclonal and monoclonal antibodies. The antibodies were characterized using ELISA, Western blotting, and immunofluorescence techniques. The results obtained with polyclonal antibodies suggest the presence of specific proteins for each studied isolate and co-reactive immunochemical profiles among conserved components. Ten monoclonal antibody clones were obtained; mAb3 recognized 3 out of 4 samples studied. The results of this study may help standardize criteria for identifying and characterizing Acanthamoeba strains. Taken together, our results support the view that a set of features may help differentiate Acanthamoeba species and isolates.

  9. Permissiveness of freshly isolated environmental strains of amoebae for growth of Legionella pneumophila.

    PubMed

    Dupuy, Mathieu; Binet, Marie; Bouteleux, Celine; Herbelin, Pascaline; Soreau, Sylvie; Héchard, Yann

    2016-03-01

    Legionella pneumophila is a pathogenic bacterium commonly found in water and responsible for severe pneumonia. Free-living amoebae are protozoa also found in water, which feed on bacteria by phagocytosis. Under favorable conditions, some L. pneumophila are able to resist phagocytic digestion and even multiply within amoebae. However, it is not clear whether L. pneumophila could infect at a same rate a large range of amoebae or if there is some selectivity towards specific amoebal genera or strains. Also, most studies have been performed using collection strains and not with freshly isolated strains. In our study, we assess the permissiveness of freshly isolated environmental strains of amoebae, belonging to three common genera (i.e. Acanthamoeba, Naegleria and Vermamoeba), for growth of L. pneumophila at three different temperatures. Our results indicated that all the tested strains of amoebae were permissive to L. pneumophila Lens and that there was no significant difference between the strains. Intracellular proliferation was more efficient at a temperature of 40°C. In conclusion, our work suggests that, under favorable conditions, virulent strains of L. pneumophila could equally infect a large number of isolates of common freshwater amoeba genera.

  10. Cytopathogenicity and molecular subtyping of Legionella pneumophila environmental isolates from 17 hospitals.

    PubMed

    Garcia-Nuñez, M; Pedro-Botet, M L; Ragull, S; Sopena, N; Morera, J; Rey-Joly, C; Sabria, M

    2009-02-01

    The cytopathogenicity of 22 Legionella pneumophila isolates from 17 hospitals was determined by assessing the dose of bacteria necessary to produce 50% cytopathic effect (CPED50) in U937 human-derived macrophages. All isolates were able to infect and grow in macrophage-like cells (range log10 CPED50: 2.67-6.73 c.f.u./ml). Five groups were established and related to the serogroup, the number of PFGE patterns coexisting in the same hospital water distribution system, and the possible reporting of hospital-acquired Legionnaires' disease cases. L. pneumophila serogroup 1 isolates had the highest cytopathogenicity (P=0.003). Moreover, a trend to more cytopathogenic groups (groups 1-3) in hospitals with more than one PFGE pattern of L. pneumophila in the water distribution system (60% vs. 17%) and in hospitals reporting cases of hospital-acquired Legionnaires' disease (36.3% vs. 16.6%) was observed. We conclude that the cytopathogenicty of environmental L. pneumophila should be taken into account in evaluating the risk of a contaminated water reservoir in a hospital and hospital acquisition of Legionnaires' disease.

  11. Bioinformatic evaluation of the secondary metabolism of antistaphylococcal environmental bacterial isolates.

    PubMed

    Wyatt, Morgan A; Lee, Jonghyun; Ahilan, Yasodha; Magarvey, Nathan A

    2013-07-01

    The increasing occurrence of drug-resistant Staphylococcus aureus is exacerbated with a declining rate of antibiotic discovery, particularly those with new mechanisms of action. The decline in antibiotic discovery from traditional sources, such as soil actinobacteria, necessitates examination of lesser studied microbes. Here, we present a strategy to select for organisms that may have a propensity to result in new antistaphylococcal agents by using S. aureus as a bait organism, and selecting organisms that have a natural lytic activity towards it. We have isolated over 80 environmental isolates and typed these organisms using 16S rDNA sequence comparison and deployed bioinformatics to assess the secondary metabolic potential of the isolated antistaphylococcal bacteria using genomic sequences. Bioinformatic analysis highlights the enriched and unique suite of potential antibiotic polyketides and nonribosomal peptides and lantibiotic gene clusters from these organisms. Profiling organic microbial extracts further showed that many of the organisms from the 10 staphylolytic genera secrete agents with antistaphylococcal activity and may serve as new sources for future antistaphylococcal drug discovery.

  12. Physiological behaviour of gliotoxigenic Aspergillus fumigatus sensu stricto isolated from maize silage under simulated environmental conditions.

    PubMed

    Alonso, V; Vergara, L Díaz; Aminahuel, C; Pereyra, C; Pena, G; Torres, A; Dalcero, A; Cavaglieri, L

    2015-01-01

    Environmental conditions play a key role in fungal development. During the silage production process, humidity, oxygen availability and pH vary among lactic-fermentation phases and among different silage sections. The aim of this work was to study the physiological behaviour of gliotoxicogenic Aspergillus fumigatus strains isolated from maize silage under simulated natural physicochemical conditions - different water activities (a(W)), temperatures (Tº), pH and oxygen pressure - on the growth parameters (growth rate and lag phase) and gliotoxin production. The silage was made with the harvested whole maize plant that was chopped and used for trench-type silo fabrication. Water activity and pH of the silage samples were determined. Total fungal counts were performed on Dichloran Rose Bengal Chloramphenicol agar and Dichloran 18% Glycerol agar. The morphological identification of A. fumigatus was performed with different culture media and at different growth temperature to observe microscopic and macroscopic characteristics. Gliotoxin production by A. fumigatus was determined by HPLC. All strains isolated were morphologically identified as A. fumigatus. Two A. fumigatus strains isolated from the silage samples were selected for the ecophysiological study (A. fumigatus sensu stricto RC031 and RC032). The results of this investigation showed that the fungus grows in the simulated natural physicochemical conditions of corn silage and produces gliotoxin. The study of the physiological behaviour of gliotoxigenic A. fumigatus under simulated environmental conditions allowed its behaviour to be predicted in silage and this will in future enable appropriate control strategies to be developed to prevent the spread of this fungus and toxin production that leads to impairment and reduced quality of silage.

  13. Cryptic transposable phages of Pseudomonas aeruginosa

    SciTech Connect

    Krylov, V.N.; Mit`kina, L.N.; Pleteneva, E.A.; Aleshin, V.V.

    1995-11-01

    Frequencies of nucleotide sequences homologous to phage transposons (PT) of two species, D3112 and B3, were assessed in genomes of natural Pseudomonas aeruginosa strains by the dot-blot hybridization method. These strains were incapable of liberating viable phages on a lawn of the PA01 standard indicator strain of P. aeruginosa. It was shown that the homologies detected belong to two groups, high and intermediate, with respect to homology level. Homology patterns were classified as high when they provided signals comparable to those for hybridization in a positive control; patterns were classified as intermediate when the hybridization level was higher than the background level, but lower than in the positive control. Homologous PT sequences were designated as cryptic PT. Intact cryptic PT prophages were shown to exist in genomes of particular natural strains manifesting a higher level of hybridization. However, the growth of these phages was limited by the restriction system of strain PA01. It is possible to isolate strains maintaining the growth of some cryptic PT. These strains differed from P. aeruginosa with respect to the specificity of the restriction and modification system. Nevertheless, in most cases, the attempt to identify a novel host capable of maintaining growth of a cryptic PT failed. Natural strains often carry cryptic PT related to both known PT species, D3112 and B3. The frequency of cryptic PT is extremely high, reaching 30% in strains with a high level of homology only and up to 50% in all strains exhibiting homology. This high PT frequency is assumed to be associated with the considerable variation of P. aeruginosa. 15 refs., 1 fig., 2 tabs.

  14. Isolation of phenazine 1,6-di-carboxylic acid from Pseudomonas aeruginosa strain HRW.1-S3 and its role in biofilm-mediated crude oil degradation and cytotoxicity against bacterial and cancer cells.

    PubMed

    Dasgupta, Debdeep; Kumar, Abhinash; Mukhopadhyay, Balaram; Sengupta, Tapas K

    2015-10-01

    Pseudomonas sp. has long been known for production of a wide range of secondary metabolites during late exponential and stationary phases of growth. Phenazine derivatives constitute a large group of secondary metabolites produced by microorganisms including Pseudomonas sp. Phenazine 1,6-di-carboxylic acid (PDC) is one of such metabolites and has been debated for its origin from Pseudomonas sp. The present study describes purification and characterization of PDC isolated from culture of a natural isolate of Pseudomonas sp. HRW.1-S3 while grown in presence of crude oil as sole carbon source. The isolated PDC was tested for its effect on biofilm formation by another environmental isolate of Pseudomonas sp. DSW.1-S4 which lacks the ability to produce any phenazine compound. PDC showed profound effect on both planktonic as well as biofilm mode of growth of DSW.1-S4 at concentrations between 5 and 20 μM. Interestingly, PDC showed substantial cytotoxicity against three cancer cell lines and against both Gram-positive and Gram-negative bacteria. Thus, the present study not only opens an avenue to understand interspecific cooperation between Pseudomonas species which may lead its applicability in bioremediation, but also it signifies the scope of future investigation on PDC for its therapeutic applications.

  15. Simultaneous production of alkaline lipase and protease by antibiotic and heavy metal tolerant Pseudomonas aeruginosa.

    PubMed

    Bisht, Deepali; Yadav, Santosh Kumar; Gautam, Pallavi; Darmwal, Nandan Singh

    2013-09-01

    An efficient bacterial strain capable of simultaneous production of lipase and protease in a single production medium was isolated. Thirty six bacterial strains, isolated from diverse habitats, were screened for their lipolytic and proteolytic activity. Of these, only one bacterial strain was found to be lipase and protease producer. The 16S rDNA sequencing and phylogenetic analyses revealed that strain (NSD-09) was in close identity to Pseudomonas aeruginosa. The maximum lipase (221.4 U/ml) and protease (187.9 U/ml) activities were obtained after 28 and 24 h of incubation, respectively at pH 9.0 and 37 °C. Castor oil and wheat bran were found to be the best substrate for lipase and protease production, respectively. The strain also exhibited high tolerance to lead (1450 µg/ml) and chromium (1000 µg/ml) in agar plates. It also showed tolerance to other heavy metals, such as Co(+2) , Zn(+2) , Hg(+2) , Ni(+2) and Cd(+2) . Therefore, this strain has scope for tailing bioremediation. Presumably, this is the first attempt on P. aeruginosa to explore its potential for both industrial and environmental applications.

  16. Multilocus sequence typing of Campylobacter jejuni isolates from humans, chickens, raw milk, and environmental water in Quebec, Canada.

    PubMed

    Lévesque, Simon; Frost, Eric; Arbeit, Robert D; Michaud, Sophie

    2008-10-01

    Molecular strain typing is essential for deciphering the epidemiology of Campylobacter jejuni infections. We applied two different methods, multilocus sequence typing (MLST) and analysis of the flaA short variable repeat (SVR), to 289 isolates (163 human, 56 chicken, 34 raw milk, and 36 environmental water isolates) collected in the province of Québec, Canada, over 3 years; in addition, the analysis included the pulsed-field gel electrophoresis (PFGE) typing results for a subset of 131 isolates studied previously. MLST defined 96 sequence types (STs) and 20 clonal complexes (CCs), including 49 STs (73 isolates, 25%) and 39 alleles not previously documented in an international database. The frequency of new STs was significantly higher among water isolates than among isolates from other sources (18/36 [50%] and 55/253 [22%], respectively; P < 0.001). Nine of the 10 most prevalent CCs included isolates from humans and at least one other source; five CCs comprised exclusively or mostly human and chicken isolates. However, water and milk were the predominant nonhuman sources among the remaining CCs, suggesting that sporadic C. jejuni infections in humans may frequently arise from sources other than chickens. All three typing systems were discriminatory (discriminatory index > 0.9). Among 131 isolates analyzed by PFGE, each of the 20 types represented by two or more isolates corresponded to a single CC. In contrast, among the 14 most prevalent types detected by analysis of the flaA SVR (5 to 27 isolates each), 8 (57%) included isolates that represented multiple different CCs. The basis for these discordant results was uncertain. Antimicrobial resistance was randomly distributed among the CCs and appeared to be more closely related to the source of an isolate than its genotype. Although MLST is labor-intensive and expensive, it remains the single best method for the genotyping of C. jejuni isolates and deciphering the epidemiologic relationships among isolates.

  17. Genotypic characterization of Pseudomonas aeruginosa strains recovered from patients with cystic fibrosis after initial and subsequent colonization.

    PubMed

    Munck, A; Bonacorsi, S; Mariani-Kurkdjian, P; Lebourgeois, M; Gérardin, M; Brahimi, N; Navarro, J; Bingen, E

    2001-10-01

    Chronic infection by Pseudomonas aeruginosa (PA) in patients with cystic fibrosis (CF) is preceded by a period of colonization and acute infection. Early aggressive antibiotic treatment of initial colonisation may prevent or at least delay chronic pulmonary infection. We initiated treatment with a combination of IV beta-lactam tobramycin, followed by nebulized colistin when PA was first isolated from patients with CF. Subsequent serial PA isolates obtained from these colonized CF patients were characterized by means of molecular methods to determine whether they were genetically related to the initial strain. Initial colonization was eradicated in all 19 patients. All patients reacquired PA within 3-25 months during the 3 years of follow-up. Fourteen patients acquired a new PA strain with a distinct genotypic profile, suggesting a new source of contamination. Five patients had two PA isolates with identical genotypes, suggesting either previous undetected respiratory tract colonization or a persistent environmental source of contamination.

  18. Distribution and association between environmental and clinical isolates of Cryptococcus neoformans in Bogotá-Colombia, 2012-2015.

    PubMed

    Vélez, Norida; Escandón, Patricia

    2016-10-01

    The propagules of the fungal species Cryptococcus neoformans and C. gattii, whose varieties are distributed world wide, are the primary cause of cryptococcosis, a life threatening disease. The study of environmental and clinical isolates of Cryptococcosis is an important contribution to the epidemiology and ecology of the fungus. The aim of this work was to determine the presence of C. neoformans and C. gattii in the environment in Bogotá, Colombia's capital city and to establish the relation between clinical and environmental isolates in the period 2012-2015. From a total of 4.116 environmental samples collected between October 2012 - March 2014, 35 were positive for C. neoformans var. grubii. From 55 cryptococcosis cases reported in Bogotá during 2012-2015, 49 isolates were recovered. From those, 94% were identified as C. neoformans var. grubii molecular type VNI; 4% as VNII and 1,2% as C. neoformans var neoformans VNIV. The 84 detected clinical and environmental isolates studied had a similarity between 49-100% according with molecular typing. The correlation between environmental and clinical samples confirms the hypothesis that patients acquire the disease from environmental exposure to the fungal propagules.

  19. Distribution and association between environmental and clinical isolates of Cryptococcus neoformans in Bogotá-Colombia, 2012-2015

    PubMed Central

    Vélez, Norida; Escandón, Patricia

    2016-01-01

    The propagules of the fungal species Cryptococcus neoformans and C. gattii, whose varieties are distributed world wide, are the primary cause of cryptococcosis, a life threatening disease. The study of environmental and clinical isolates of Cryptococcosis is an important contribution to the epidemiology and ecology of the fungus. The aim of this work was to determine the presence of C. neoformans and C. gattii in the environment in Bogotá, Colombia’s capital city and to establish the relation between clinical and environmental isolates in the period 2012-2015. From a total of 4.116 environmental samples collected between October 2012 - March 2014, 35 were positive for C. neoformans var. grubii. From 55 cryptococcosis cases reported in Bogotá during 2012-2015, 49 isolates were recovered. From those, 94% were identified as C. neoformans var. grubii molecular type VNI; 4% as VNII and 1,2% as C. neoformans var neoformans VNIV. The 84 detected clinical and environmental isolates studied had a similarity between 49-100% according with molecular typing. The correlation between environmental and clinical samples confirms the hypothesis that patients acquire the disease from environmental exposure to the fungal propagules. PMID:27706379

  20. Molecular typing of environmental Cryptococcus neoformans/C. gattii species complex isolates from Manaus, Amazonas, Brazil.

    PubMed

    Alves, Gleica Soyan Barbosa; Freire, Ana Karla Lima; Bentes, Amaury Dos Santos; Pinheiro, José Felipe de Souza; de Souza, João Vicente Braga; Wanke, Bodo; Matsuura, Takeshi; Jackisch-Matsuura, Ani Beatriz

    2016-08-01

    Cryptococcus neoformans and Cryptococcus gattii are the main causative agents of cryptococcosis, a systemic fungal disease that affects internal organs and skin, and which is acquired by inhalation of spores or encapsulated yeasts. It is currently known that the C. neoformans/C. gattii species complex has a worldwide distribution, however, some molecular types seem to prevail in certain regions. Few environmental studies of Cryptococcus have been conducted in the Brazilian Amazon. This is the first ecological study of the pathogenic fungi C. neoformans/C. gattii species complex in the urban area of Manaus, Amazonas, Brazil. A total of 506 samples from pigeon droppings (n = 191), captive bird droppings (n = 60) and tree hollows (n = 255) were collected from June 2012 to January 2014 at schools and public buildings, squares, pet shops, households, the zoo and the bus station. Samples were plated on niger seed agar (NSA) medium supplemented with chloramphenicol and incubated at 25°C for 5 days. Dark-brown colonies were isolated and tested for thermotolerance at 37°C, cycloheximide resistance and growth on canavanine-glycine-bromothymol blue agar. Molecular typing was done by PCR-RFLP. Susceptibility to the antifungal drugs amphotericin B, fluconazole, itraconazole and ketoconazole was tested using Etest(®) strips. In total, 13 positive samples were obtained: one tree hollow (C. gattiiVGII), nine pigeon droppings (C. neoformansVNI) and three captive bird droppings (C. neoformansVNI). The environmental cryptococcal isolates found in this study were of the same molecular types as those responsible for infections in Manaus.

  1. Evaluation of flagella and flagellin of Pseudomonas aeruginosa as vaccines.

    PubMed

    Campodónico, Victoria L; Llosa, Nicolás J; Grout, Martha; Döring, Gerd; Maira-Litrán, Tomás; Pier, Gerald B

    2010-02-01

    Pseudomonas aeruginosa is a serious pathogen in hospitalized, immunocompromised, and cystic fibrosis (CF) patients. P. aeruginosa is motile via a single polar flagellum made of polymerized flagellin proteins differentiated into two major serotypes: a and b. Antibodies to flagella delay onset of infection in CF patients, but whether immunity to polymeric flagella and that to monomeric flagellin are comparable has not been addressed, nor has the question of whether such antibodies might negatively impact Toll-like receptor 5 (TLR5) activation, an important component of innate immunity to P. aeruginosa. We compared immunization with flagella and that with flagellin for in vitro effects on motility, opsonic killing, and protective efficacy using a mouse pneumonia model. Antibodies to flagella were superior to antibodies to flagellin at inhibiting motility, promoting opsonic killing, and mediating protection against P. aeruginosa pneumonia in mice. Protection against the flagellar type strains PAK and PA01 was maximal, but it was only marginal against motile clinical isolates from flagellum-immunized CF patients who nonetheless became colonized with P. aeruginosa. Purified flagellin was a more potent activator of TLR5 than were flagella and also elicited higher TLR5-neutralizing antibodies than did immunization with flagella. Antibody to type a but not type b flagella or flagellin inhibited TLR5 activation by whole bacterial cells. Overall, intact flagella appear to be superior for generating immunity to P. aeruginosa, and flagellin monomers might induce antibodies capable of neutralizing innate immunity due to TLR5 activation, but solid immunity to P. aeruginosa based on flagellar antigens may require additional components beyond type a and type b proteins from prototype strains.

  2. Trypsin-treated Ma-104: a sensitive cell line for isolating enteric viruses from environmental samples.

    PubMed Central

    Agbalika, F; Hartemann, P; Foliguet, J M

    1984-01-01

    During a 1-year survey of enteroviruses in wastewater samples from the Lorraine area, three widely used continuous monkey kidney cell lines were tested: BGM, Vero, and trypsin-treated Ma-104. Decontaminated samples from secondary wastewater treatment plants (influent or effluent) were directly inoculated onto cells, and viruses were revealed after two passages with a liquid medium technique. Out of the total percentage of positive isolates with the three systems (32.7) 24.7% were found with Ma-104, 14.1% with BGM, and only 1.7% with Vero cells. Poliovirus was recovered more frequently with Ma-104 (12.3%) than with BGM (1.7%). Reovirus (3.5%) and echovirus (1.7%) were only found with Ma-104 cells; however, BGM cells allowed the isolation of a few group B coxsackieviruses (5.9%). It must be pointed out that 7.0% of samples with an unconfirmed cytopathic effect were found with BGM against 3.4% found with Ma-104, but they did not have significant differences. Because of its large spectrum of sensitivity, easy maintenance, and resistance to toxic effects, trypsin-treated Ma-104 may be recommended in conjunction with other cell lines for the detection of viruses from environmental samples, especially with the use of a liquid method. PMID:6324675

  3. A hypervariable genomic island identified in clinical and environmental Mycobacterium avium subsp. hominissuis isolates from Germany.

    PubMed

    Sanchini, Andrea; Semmler, Torsten; Mao, Lei; Kumar, Narender; Dematheis, Flavia; Tandon, Kshitij; Peddireddy, Vidyullatha; Ahmed, Niyaz; Lewin, Astrid

    2016-11-01

    Mycobacterium avium subsp. hominissuis (MAH) is an opportunistic human pathogen widespread in the environment. Genomic islands (GI)s represent a part of the accessory genome of bacteria and influence virulence, drug-resistance or fitness and trigger bacterial evolution. We previously identified a novel GI in four MAH genomes. Here, we further explored this GI in a larger collection of MAH isolates from Germany (n=41), including 20 clinical and 21 environmental isolates. Based on comparative whole genome analysis, we detected this GI in 39/41 (95.1%) isolates. Although all these GIs integrated in the same insertion hotspot, there is high variability in the genetic structure of this GI: eight different types of GI have been identified, designated A-H (sized 6.2-73.3kb). These GIs were arranged as single GI (23/41, 56.1%), combination of two different GIs (14/41, 34.1%) or combination of three different GIs (2/41, 4.9%) in the insertion hotspot. Moreover, two GI types shared more than 80% sequence identity with sequences of M. canettii, responsible for Tuberculosis. A total of 253 different genes were identified in all GIs, among which the previously documented virulence-related genes mmpL10 and mce. The diversity of the GI and the sequence similarity with other mycobacteria suggests cross-species transfer, involving also highly pathogenic species. Shuffling of potential virulence genes such as mmpL10 via this GI may create new pathogens that can cause future outbreaks.

  4. The effects of environmental enrichment on depressive- and anxiety-relevant behaviors in socially isolated prairie voles

    PubMed Central

    Grippo, Angela J.; Ihm, Elliott; Wardwell, Joshua; McNeal, Neal; Scotti, Melissa-Ann L.; Moenk, Deirdre A.; Chandler, Danielle L.; LaRocca, Meagan A.; Preihs, Kristin

    2014-01-01

    Objectives Social isolation is associated with depression, anxiety and negative health outcomes. Environmental enrichment, including environmental and cognitive stimulation with inanimate objects and opportunities for physical exercise, may be an effective strategy to include in treatment paradigms for affective disorders as a function of social isolation. In a rodent model – the socially monogamous prairie vole – we investigated the hypothesis that depression- and anxiety-related behaviors following social isolation would be prevented and remediated with environmental enrichment. Methods Experiment 1 investigated the preventive effects of environmental enrichment on negative affective behaviors when administered concurrently with social isolation. Experiment 2 investigated the remediating effects of enrichment on negative affective behaviors when administered following a period of isolation. Behaviors were measured in 3 operational tests: open field; forced swim test; and elevated plus maze. Results In isolated prairie voles, enrichment prevented depression- (immobility in FST, group × housing interaction, P=0.049) and anxiety-relevant behaviors (exploration in open field, group × housing interaction, P=0.036; exploration in elevated plus maze, group × housing interaction, P=0.049). Delayed enrichment also remediated these behaviors in isolated animals (immobility in forced swim test, main effect of housing, P=0.001; exploration in open field, main effect of housing, P=0.047; exploration in elevated plus maze, main effect of housing, P=0.001), and was slightly more effective than physical exercise alone in remediating anxiety-relevant behaviors. Conclusions These findings provide insight into the beneficial effects of an enriched environment on depression- and anxiety-relevant behaviors using a translational rodent model of social isolation. PMID:24804886

  5. Detection of Metallo-Beta Lactamases Among Carbapenem-Resistant Pseudomonas aeruginosa

    PubMed Central

    Farajzadeh Sheikh, Ahmad; Rostami, Soodabeh; Jolodar, Abbas; Tabatabaiefar, Mohammad Amin; Khorvash, Farzin; Saki, Azadeh; Shoja, Saeed; Sheikhi, Raheleh

    2014-01-01

    Background: Carbapenems are important drugs used for the treatment of Pseudomonas aeruginosa infections, however metallo-β-lactamases (MBL) are able to efficiently hydrolyze these classes of drugs. Immediate detection of the MBL-producing P. aeruginosa is necessary in order to accurately treat infections caused by this organism. Objectives: To determine the prevalence of MBL producing P. aeruginosa in burn and non-burn patients by two phenotypic tests and polymerase chain reaction (PCR) and to compare phenotypic tests with PCR. Materials and Methods: A total of 223 non-duplicate strains of P. aeruginosa were collected from three teaching hospitals of Ahvaz, Iran. Antimicrobial susceptibility and minimum inhibitory concentrations (MICs) of carbapenems (imipenem, meropenem, doripenem and ertapenem) were determined by the Kirby-Bauer and E-test methods. Combined disk (CD) test, MBL E-test and PCR were performed for carbapenem-resistant P. aeruginosa isolates. Results: Amongst all the P. aeruginosa isolates, 58.7% were resistant to imipenem while 31.8%, 13.5% and 74.4% were resistant to meropenem, doripenem and ertapenem, respectively. Amongst all the P. aeruginosa isolates, 44.4% were multidrug resistant and 13.45% were resistant to all of the carbapenems. The CD test with doripenem disk / 750 μg ethylene diamine tetra acetic acid (EDTA) had the highest efficiency compared to the other phenotypic tests. blaIMP and blaVIM genes were detected in 11.7% and 0.4% of isolates, respectively. blaSPM and blaNDM genes were not observed. Conclusions: Epidemiological and regional evaluation of MBL-producing P. aeruginosa through simple and inexpensive methods should be considered for effective treatment of carbapenem-resistant P. aeruginosa infections. PMID:25774271

  6. Virulence genes in clinical and environmental Stenotrophomas maltophilia isolates: a genome sequencing and gene expression approach.

    PubMed

    Adamek, Martina; Linke, Burkhard; Schwartz, Thomas

    2014-01-01

    The rate of nosocomial infections with the opportunistic pathogen Stenotrophomonas maltophilia has remarkably increased in the last decade. To determine S. maltophilia virulence genes, the complete genome sequences of two S. maltophilia isolates were compared. The clinical strain SKK35 was proved virulent in an amoeba host-pathogen model, and wastewater strain RA8 was determined as non-virulent in the amoeba model. The genome sequences of three additional S. maltophilia strains, K279a (clinical, non-virulent against amoeba), R511-3 and SKA14 (both environmental, non-virulent against amoeba) were taken into account as reference strains. We were able to show that all clinical and environmental S. maltophilia strains presented comparable distribution of so far identified potential virulence genes, regardless to their virulence potential against amoebae. Aside from that, strain SKK35 was found harboring a putative, strain specific pathogenicity island, encoding two proteins from the RTX (repeats-in-toxin) family. The actual expression of the RTX genes was verified in growth experiments in different culture media containing blood or blood components and in co-cultures with amoeba.

  7. Development and validation of benomyl birdseed agar for the isolation of Cryptococcus neoformans and Cryptococcus gattii from environmental samples.

    PubMed

    Pham, Cau D; Ahn, Stacey; Turner, Lance A; Wohrle, Ron; Lockhart, Shawn R

    2014-05-01

    One of the difficulties of isolating Cryptococcus neoformans and Cryptococcus gattii from environmental samples is the abundant overgrowth of other yeast and mold species that occurs on the plates. Here we report the application of benomyl to Guizotia abyssinica seed extract growth medium to improve the isolation of C. neoformans and C. gattii from environmental samples. We validated this medium by recovering C. neoformans and C. gattii from convenience soils and swabs from a region of the United States where these yeasts are endemic.

  8. Environmental carbonate chemistry selects for phenotype of recently isolated strains of Emiliania huxleyi

    NASA Astrophysics Data System (ADS)

    Rickaby, Rosalind E. M.; Hermoso, Michaël; Lee, Renee B. Y.; Rae, Benjamin D.; Heureux, Ana M. C.; Balestreri, Cecilia; Chakravarti, Leela; Schroeder, Declan C.; Brownlee, Colin

    2016-05-01

    Coccolithophorid algae, particularly Emiliania huxleyi, are prolific biomineralisers that, under many conditions, dominate communities of marine eukaryotic plankton. Their ability to photosynthesise and form calcified scales (coccoliths) has placed them in a unique position in the global carbon cycle. Contrasting reports have been made with regards to the response of E. huxleyi to ocean acidification. Therefore, there is a pressing need to further determine the fate of this key organism in a rising CO2 world. In this paper, we investigate the phenotype of newly isolated, genetically diverse, strains of E. huxleyi from UK Ocean Acidification Research Programme (UKOA) cruises around the British Isles, the Arctic, and the Southern Ocean. We find a continuum of diversity amongst the physiological and photosynthetic parameters of different strains of E. huxleyi morphotype A under uniform, ambient conditions imposed in the laboratory. This physiology is best explained by adaptation to carbonate chemistry in the former habitat rather than being prescribed by genetic fingerprints such as the coccolithophore morphology motif (CMM). To a first order, the photosynthetic capacity of each strain is a function of both aqueous CO2 availability, and calcification rate, suggestive of a link between carbon concentrating ability and calcification. The calcification rate of each strain is related linearly to the natural environmental [CO32-] at the site of isolation, but a few exceptional strains display low calcification rates at the highest [CO32-] when calcification is limited by low CO2 availability and/or a lack of a carbon concentrating mechanism. We present O2-electrode measurements alongside coccolith oxygen isotopic composition and the uronic acid content (UAC) of the coccolith associated polysaccharide (CAP), that act as indirect tools to show the differing carbon concentrating ability of the strains. The environmental selection revealed amongst our recently isolated strain

  9. Gold-functionalized magnetic nanoparticles restrict growth of Pseudomonas aeruginosa.

    PubMed

    Niemirowicz, Katarzyna; Swiecicka, Izabela; Wilczewska, Agnieszka Z; Misztalewska, Iwona; Kalska-Szostko, Beata; Bienias, Kamil; Bucki, Robert; Car, Halina

    2014-01-01

    Superparamagnetic iron oxide nanoparticles (SPIONs) and their derivatives (aminosilane and gold-coated) have been widely investigated in numerous medical applications, including their potential to act as antibacterial drug carriers that may penetrate into bacteria cells and biofilm mass. Pseudomonas aeruginosa is a frequent cause of infection in hospitalized patients, and significant numbers of currently isolated clinical strains are resistant to standard antibiotic therapy. Here we describe the impact of three types of SPIONs on the growth of P. aeruginosa during long-term bacterial culture. Their size, structure, and physicochemical properties were determined using transmission electron microscopy, X-ray diffraction analysis, and Fourier transform infrared spectroscopy. We observed significant inhibition of P. aeruginosa growth in bacterial cultures continued over 96 hours in the presence of gold-functionalized nanoparticles (Fe₃O₄@Au). At the 48-hour time point, growth of P. aeruginosa, as assessed by the number of colonies grown from treated samples, showed the highest inhibition (decreased by 40%). These data provide strong evidence that Fe₃O₄@Au can dramatically reduce growth of P. aeruginosa and provide a platform for further study of the antibacterial activity of this nanomaterial.

  10. Serotyping of 467 Cryptococcus neoformans Isolates from Clinical and Environmental Sources in Brazil: Analysis of Host and Regional Patterns

    PubMed Central

    Nishikawa, Marília M.; Lazera, Márcia S.; Barbosa, Glaucia G.; Trilles, Luciana; Balassiano, Beatriz R.; Macedo, Regina C. L.; Bezerra, Cláudia C. F.; Pérez, Maurício A.; Cardarelli, Paola; Wanke, Bodo

    2003-01-01

    Cryptococcus neoformans is an important zoopathogen, and it is one of the most prevalent lethal mycotic agents. Its polysaccharide capsule, synthesized in vivo and in vitro, is a virulence factor, contains predominantly glucuronoxylomannan, and is responsible for the antigenic differentiation of serotypes A, B, C, D, and AD. A total of 467 isolates of C. neoformans obtained from clinical and environmental sources from Brazilian regions were studied serologically by using the Crypto Check Iatron RM 304-K kit. Serotyping of the clinical isolates showed the following prevalences of the serotypes: A (77.95%), followed by B (18.2%), AD (1.3%), D (0.4%), C (0.2%), and untypeable (1.93%). The epidemiology of serotype A in the Brazilian southern and southeastern regions reproduces the picture observed worldwide. In contrast, serotype B was the most frequent agent of cryptococcosis in the northeastern region, occurring nearly equally in male and female healthy hosts. Among the isolates from environmental sources, serotypes A and B were found to occur in the hollows of tropical trees of the genera Cassia, Ficus, and Moquillea. The few isolates from Eucalyptus camaldulensis debris were serotypes A and B and untypeable. Overall, no association with a specific host tree was identified for these serotypes, denoting a distinct ecoepidemiological regional pattern. The one serotype C isolate was recovered from a human immunodeficiency virus-negative host. Serotype AD predominated over serotype D among both clinical and environmental isolates. PMID:12517828

  11. Genomic profiles of clinical and environmental isolates of Vibrio cholerae O1 in cholera-endemic areas of Bangladesh

    PubMed Central

    Zo, Young-Gun; Rivera, Irma N. G.; Russek-Cohen, Estelle; Islam, M. Sirajul; Siddique, A. K.; Yunus, M.; Sack, R. Bradley; Huq, Anwar; Colwell, Rita R.

    2002-01-01

    Diversity, relatedness, and ecological interactions of toxigenic Vibrio cholerae O1 populations in two distinctive habitats, the human intestine and the aquatic environment, were analyzed. Twenty environmental isolates and 42 clinical isolates were selected for study by matching serotype, geographic location of isolation in Bangladesh, and season of isolation. Genetic profiling was done by enterobacterial repetitive intergenic consensus sequence–PCR, optimized for profiling by using the fully sequenced V. cholerae El Tor N16961 genome. Five significant clonal clusters of haplotypes were found from 57 electrophoretic types. Isolates from different areas or habitats intermingled in two of the five significant clusters. Frequencies of haplotypes differed significantly only between the environmental populations (exact test; P < 0.05). Analysis of molecular variance yielded a population genetic structure reflecting the differentiating effects of geographic area, habitat, and sampling time. Although a parameter confounding the latter differences explained 9% of the total molecular variance in the entire population (P < 0.01), the net effect of habitat and time could not be separated because of the small number of environmental isolates included in the study. Five subpopulations from a single area were determined, and from these we were able to estimate a relative differentiating effect of habitat, which was small compared with the effect of temporal change. In conclusion, the resulting population structure supports the hypothesis that spatial and temporal fluctuations in the composition of toxigenic V. cholerae populations in the aquatic environment can cause shifts in the dynamics of the disease. PMID:12205294

  12. Pseudomonas aeruginosa outbreak in a pediatric oncology care unit caused by an errant water jet into contaminated siphons.

    PubMed

    Schneider, Henriette; Geginat, Gernot; Hogardt, Michael; Kramer, Alexandra; Dürken, Matthias; Schroten, Horst; Tenenbaum, Tobias

    2012-06-01

    We analyzed an outbreak of invasive infections with an exotoxin U positive Pseudomonas aeruginosa strain within a pediatric oncology care unit. Environmental sampling and molecular characterization of the Pseudomonas aeruginosa strains led to identification of the outbreak source. An errant water jet into the sink within patient rooms was observed. Optimized outbreak management resulted in an abundance of further Pseudomonas aeruginosa infections within the pediatric oncology care unit.

  13. Effects Due to Rhizospheric Soil Application of an Antagonistic Bacterial Endophyte on Native Bacterial Community and Its Survival in Soil: A Case Study with Pseudomonas aeruginosa from Banana

    PubMed Central

    Thomas, Pious; Sekhar, Aparna C.

    2016-01-01

    native microbial community. Direct agar-plate challenge assays with individual environmental bacterial isolates displayed varying interactive or antagonistic effects. In effect, the application of P. aeruginosa in rhizospheric soil did not serve any net benefit in terms of sustained survival. Conversely, it caused a disturbance to the native soil bacterial community. The findings highlight the need for monitoring the bio-inoculant(s) in field-soil and assessing the interactive effects with native microbial community before commercial recommendation. varying interactive or antagonistic effects. In effect, the application of P. aeruginosa in rhizospheric soil did not serve any net benefit in terms of sustained survival. Conversely, it caused a disturbance to the native soil bacterial community. The findings highlight the need for monitoring the bio-inoculant(s) in field-soil and assessing the interactive effects with native microbial community before commercial recommendation. PMID:27199897

  14. Assessment of biofilm formation in Pseudomonas aeruginosa by antisense mazE-PNA.

    PubMed

    Valadbeigi, Hassan; Sadeghifard, Nourkhoda; Salehi, Majid Baseri

    2017-03-01

    The hallmark patogenicity in Pseudomonas aeruginosa (P. aeruginosa) is biofilm formation that is not easy to eradicate, because it has variety mechanisms for antibiotic resistance. In addition, toxin-antitoxin (TA) system may play role in biofilm formation. The current study aimed to evaluate the role of TA loci in biofilm formation. Therefore, 18 P. aeruginosa clinical isolates were collected and evaluated for specific biofilm and TA genes. The analysis by RT-qPCR demonstrated that expression of mazE antitoxin in biofilm formation was increase. On the other hand, mazE antitoxin TA system was used as target for antisense PNA. mazE-PNA was able to influence in biofilm formation and was inhibit at 5,10 and 15 μM concentrations biofilm formation in P. aeruginosa. Therefore, it could be highlighted target for anti-biofilm target to eradicate P. aeruginosa biofilm producer.

  15. Pseudomonas aeruginosa Lifestyle: A Paradigm for Adaptation, Survival, and Persistence

    PubMed Central

    Moradali, M. Fata; Ghods, Shirin; Rehm, Bernd H. A.

    2017-01-01

    Pseudomonas aeruginosa is an opportunistic pathogen affecting immunocompromised patients. It is known as the leading cause of morbidity and mortality in cystic fibrosis (CF) patients and as one of the leading causes of nosocomial infections. Due to a range of mechanisms for adaptation, survival and resistance to multiple classes of antibiotics, infections by P. aeruginosa strains can be life-threatening and it is emerging worldwide as public health threat. This review highlights the diversity of mechanisms by which P. aeruginosa promotes its survival and persistence in various environments and particularly at different stages of pathogenesis. We will review the importance and complexity of regulatory networks and genotypic-phenotypic variations known as adaptive radiation by which P. aeruginosa adjusts physiological processes for adaptation and survival in response to environmental cues and stresses. Accordingly, we will review the central regulatory role of quorum sensing and signaling systems by nucleotide-based second messengers resulting in different lifestyles of P. aeruginosa. Furthermore, various regulatory proteins will be discussed which form a plethora of controlling systems acting at transcriptional level for timely expression of genes enabling rapid responses to external stimuli and unfavorable conditions. Antibiotic resistance is a natural trait for P. aeruginosa and multiple mechanisms underlying different forms of antibiotic resistance will be discussed here. The importance of each mechanism in conferring resistance to various antipseudomonal antibiotics and their prevalence in clinical strains will be described. The underlying principles for acquiring resistance leading pan-drug resistant strains will be summarized. A future outlook emphasizes the need for collaborative international multidisciplinary efforts to translate current knowledge into strategies to prevent and treat P. aeruginosa infections while reducing the rate of antibiotic resistance

  16. Pseudomonas aeruginosa Lifestyle: A Paradigm for Adaptation, Survival, and Persistence.

    PubMed

    Moradali, M Fata; Ghods, Shirin; Rehm, Bernd H A

    2017-01-01

    Pseudomonas aeruginosa is an opportunistic pathogen affecting immunocompromised patients. It is known as the leading cause of morbidity and mortality in cystic fibrosis (CF) patients and as one of the leading causes of nosocomial infections. Due to a range of mechanisms for adaptation, survival and resistance to multiple classes of antibiotics, infections by P. aeruginosa strains can be life-threatening and it is emerging worldwide as public health threat. This review highlights the diversity of mechanisms by which P. aeruginosa promotes its survival and persistence in various environments and particularly at different stages of pathogenesis. We will review the importance and complexity of regulatory networks and genotypic-phenotypic variations known as adaptive radiation by which P. aeruginosa adjusts physiological processes for adaptation and survival in response to environmental cues and stresses. Accordingly, we will review the central regulatory role of quorum sensing and signaling systems by nucleotide-based second messengers resulting in different lifestyles of P. aeruginosa.