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Tidbury HJ, Joiner CL, Rimmer GSE, Potter HV, Taylor NGH. The effectiveness of fishery net dips: Advice for the improvement of biosecurity measures. JOURNAL OF FISH DISEASES 2018; 41:1625-1630. [PMID: 30091241 DOI: 10.1111/jfd.12868] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 06/19/2018] [Accepted: 06/20/2018] [Indexed: 06/08/2023]
Abstract
Disease poses a major threat to aquaculture and commercial and recreational fisheries globally. Biosecurity measures have been implemented; however, empirical evidence of their efficacy in situ is lacking. Here, we present the results from a study conducted to examine the effectiveness of disinfectant net dips. Samples were collected from disinfectant net dips at 25 recreational fisheries in south-west England and assessed to determine (a) the level of bacterial contamination and (b) the reduction in titre of a target virus (infectious pancreatic necrosis virus, IPNV) following a contact time of 2 and 5 min. In addition, the study examined the reduction in target virus titre following exposure to laboratory prepared Virkon® , representing "clean," "dirty" and "diluted and dirty" conditions, for 2 and 5 min. Bacterial contamination was high in 64% of disinfectant samples, and, 76% of disinfectant samples did not effectively reduce the target virus titre in 2 or 5 min. Virus titre was successfully reduced following exposure to laboratory prepared Virkon® for 2 or 5 min, although dilution and contamination reduced the effectiveness. These results suggest that disinfectant net dips may not be working effectively on a high proportion of fishery sites. We provide recommendations for improving biosecurity.
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Affiliation(s)
- Hannah J Tidbury
- Centre for Environment, Fisheries and Aquaculture Science, Weymouth, UK
| | - Claire L Joiner
- Centre for Environment, Fisheries and Aquaculture Science, Weymouth, UK
| | | | - Holly V Potter
- Centre for Environment, Fisheries and Aquaculture Science, Weymouth, UK
- School of Biology, University of Leeds, Leeds, UK
| | - Nick G H Taylor
- Centre for Environment, Fisheries and Aquaculture Science, Weymouth, UK
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Alterations of Salmonella enterica Serovar Typhimurium Antibiotic Resistance under Environmental Pressure. Appl Environ Microbiol 2018; 84:AEM.01173-18. [PMID: 30054356 DOI: 10.1128/aem.01173-18] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 07/16/2018] [Indexed: 12/22/2022] Open
Abstract
Microbial horizontal gene transfer is a continuous process that shapes bacterial genomic adaptation to the environment and the composition of concurrent microbial ecology. This includes the potential impact of synthetic antibiotic utilization in farm animal production on overall antibiotic resistance issues; however, the mechanisms behind the evolution of microbial communities are not fully understood. We explored potential mechanisms by experimentally examining the relatedness of phylogenetic inference between multidrug-resistant Salmonella enterica serovar Typhimurium isolates and pathogenic Salmonella Typhimurium strains based on genome-wide single-nucleotide polymorphism (SNP) comparisons. Antibiotic-resistant S Typhimurium isolates in a simulated farm environment barely lost their resistance, whereas sensitive S Typhimurium isolates in soils gradually acquired higher tetracycline resistance under antibiotic pressure and manipulated differential expression of antibiotic-resistant genes. The expeditious development of antibiotic resistance and the ensuing genetic alterations in antimicrobial resistance genes in S Typhimurium warrant effective actions to control the dissemination of Salmonella antibiotic resistance.IMPORTANCE Antibiotic resistance is attributed to the misuse or overuse of antibiotics in agriculture, and antibiotic resistance genes can also be transferred to bacteria under environmental stress. In this study, we report a unidirectional alteration in antibiotic resistance from susceptibility to increased resistance. Highly sensitive Salmonella enterica serovar Typhimurium isolates from organic farm systems quickly acquired tetracycline resistance under antibiotic pressure in simulated farm soil environments within 2 weeks, with expression of antibiotic resistance-related genes that was significantly upregulated. Conversely, originally resistant S Typhimurium isolates from conventional farm systems lost little of their resistance when transferred to environments without antibiotic pressure. Additionally, multidrug-resistant S Typhimurium isolates genetically shared relevancy with pathogenic S Typhimurium isolates, whereas susceptible isolates clustered with nonpathogenic strains. These results provide detailed discussion and explanation about the genetic alterations and simultaneous acquisition of antibiotic resistance in S Typhimurium in agricultural environments.
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Srinivasan B, Tonddast-Navaei S, Roy A, Zhou H, Skolnick J. Chemical space of Escherichia coli dihydrofolate reductase inhibitors: New approaches for discovering novel drugs for old bugs. Med Res Rev 2018; 39:684-705. [PMID: 30192413 DOI: 10.1002/med.21538] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 07/16/2018] [Accepted: 08/09/2018] [Indexed: 12/15/2022]
Abstract
Escherichia coli Dihydrofolate reductase is an important enzyme that is essential for the survival of the Gram-negative microorganism. Inhibitors designed against this enzyme have demonstrated application as antibiotics. However, either because of poor bioavailability of the small-molecules resulting from their inability to cross the double membrane in Gram-negative bacteria or because the microorganism develops resistance to the antibiotics by mutating the DHFR target, discovery of new antibiotics against the enzyme is mandatory to overcome drug-resistance. This review summarizes the field of DHFR inhibition with special focus on recent efforts to effectively interface computational and experimental efforts to discover novel classes of inhibitors that target allosteric and active-sites in drug-resistant variants of EcDHFR.
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Affiliation(s)
- Bharath Srinivasan
- Center for the Study of Systems Biology, School of Biology, Georgia Institute of Technology, Atlanta, Georgia
| | - Sam Tonddast-Navaei
- Center for the Study of Systems Biology, School of Biology, Georgia Institute of Technology, Atlanta, Georgia
| | - Ambrish Roy
- Center for the Study of Systems Biology, School of Biology, Georgia Institute of Technology, Atlanta, Georgia
| | - Hongyi Zhou
- Center for the Study of Systems Biology, School of Biology, Georgia Institute of Technology, Atlanta, Georgia
| | - Jeffrey Skolnick
- Center for the Study of Systems Biology, School of Biology, Georgia Institute of Technology, Atlanta, Georgia
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Susceptibility of Methicillin-Resistant and -Susceptible Staphylococcus aureus Isolates of Various Clonal Lineages from Germany to Eight Biocides. Appl Environ Microbiol 2018; 84:AEM.00799-18. [PMID: 29728378 DOI: 10.1128/aem.00799-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 04/26/2018] [Indexed: 12/15/2022] Open
Abstract
Few studies have been conducted on the susceptibility of bacteria to biocides. A total of 182 methicillin-resistant and -susceptible Staphylococcus aureus isolates collected from healthy or diseased humans and animals in Germany were included in the present study. Sixty-three isolates of animal origin and 119 human isolates were tested for their MICs to eight biocides or heavy metals by the broth microdilution method. The MIC50 and MIC90 values of human and animal isolates were equal or differed by not more than 1 dilution step, and statistical analysis revealed that differences between MICs of human and animal isolates were not significant. However, when taking into account the multilocus sequence type (MLST), a strong tendency (P = 0.054) to higher MICs of silver nitrate was detected for clonal complex 398 (CC398) isolates from humans compared to those from animals. Furthermore, a comparison of MIC values from isolates belonging to different clonal lineages revealed that important human lineages such as CC22 and CC5 exhibited significantly (P < 0.05) higher MICs for the biocides chlorhexidine, benzethonium chloride, and acriflavine than the main animal lineage sequence type 398 (ST398). Isolates with elevated MIC values were tested for the presence of biocide and heavy metal tolerance-mediating genes by PCR assays, and the following genes were detected: mepA (n [no. of isolates containing the gene] = 44), lmrS (n = 36), norA (n = 35), sepA (n = 22), mco (n = 5), czrC (n = 3), smr (n = 2), copA (n = 1), qacA and/or -B (n = 1), qacG (n = 2), and qacJ (n = 1). However, only for some compounds was a correlation between the presence of a biocide tolerance gene and the level of MIC values detected.IMPORTANCE Biocides play an essential role in controlling the growth of microorganisms and the dissemination of nosocomial pathogens. In this study, we determined the susceptibility of methicillin-resistant and -susceptible S. aureus isolates from humans and animals to various biocides and heavy metal ions and analyzed differences in susceptibilities between important clonal lineages. In addition, the presence of biocide or heavy metal tolerance-mediating genes was investigated. We demonstrated that important human lineages such as CC22 and CC5 had significantly higher MIC values for chlorhexidine, benzethonium chloride, and acriflavine than the main farm animal lineage, ST398. In addition, it was shown that for some combinations of biocides and tolerance genes, significantly higher MICs were detected for carriers. These findings provide new insights into S. aureus biocide and heavy metal tolerance.
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Distribution of biocide resistant genes and biocides susceptibility in multidrug-resistant Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii - A first report from the Kingdom of Saudi Arabia. J Infect Public Health 2018; 11:812-816. [PMID: 29907439 DOI: 10.1016/j.jiph.2018.05.011] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 05/21/2018] [Accepted: 05/28/2018] [Indexed: 11/24/2022] Open
Abstract
PURPOSES The aim of this study was to determine the frequency of biocide resistant genes, qacA, qacE and cepA in multidrug resistant (MDR) bacteria: Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii and to correlate the presence or absence of resistant genes with biocides susceptibility. MATERIALS AND METHODS The study included 44 MDR K. pneumoniae, P. aeruginosa and A. baumannii microorganisms. The bacteria were screened for the presence of biocide resistant genes by the polymerase chain reaction (PCR) method. The test organisms were isolated from various clinical specimens in the Qassim region, Saudi Arabia. The in vitro susceptibility tests of the three biocides (benzalkonium chloride, cetrimide and chlorhexidine gluconate) were studied against the test isolates by broth microdilution method following Clinical and Laboratory Standards Institute guidelines. RESULTS With the distribution of biocide resistant genes in K. pneumoniae, all 9 isolates (100%) possessed cepA; 4 (44.4%) and 1 (11.1%) isolate contained qacA and qacE genes respectively. Among 24 isolates of A. baumannii tested, cepA, qacA and qacE genes were found in 54.2%, 16.7% and 33.3% of isolates respectively. Among 11 P. aeruginosa isolates, 63.6% contained cepA gene, 18.2% contained qacE genes, and none of the isolates harboured qacA gene. There was no significant correlation between presence or absence of biocide resistant genes and high MIC values of the test isolates (p≥0.2). CONCLUSION Our observations imply that there was no significant correlation between presence or absence of biocide resistant genes and MICs observed in MDR K. pneumoniae, P. aeruginosa and A. baumannii. Further studies are required to find to confirm the trend of reduced susceptibility to biocides of problematic nosocomial pathogens.
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Martin MS, Santos IC, Carlton DD, Stigler-Granados P, Hildenbrand ZL, Schug KA. Characterization of bacterial diversity in contaminated groundwater using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 622-623:1562-1571. [PMID: 29054663 DOI: 10.1016/j.scitotenv.2017.10.027] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 10/04/2017] [Accepted: 10/04/2017] [Indexed: 06/07/2023]
Abstract
Groundwater is a major source for drinking water in the United States, and therefore, its quality and quantity is of extreme importance. One major concern that has emerged is the possible contamination of groundwater due to the unconventional oil and gas extraction activities. As such, the impacts of exogenous contaminants on microbial ecology is an area to be explored to understand what are the chemical and physical conditions that allow the proliferation of pathogenic bacteria and to find alternatives for water treatment by identifying organic-degrading bacteria. In this work, we assess the interplay between groundwater quality and the microbiome in contaminated groundwaters rich in hydrocarbon gases, volatile organic and inorganic compounds, and various metals. Opportunistic pathogenic bacteria, such as Aeromonas hydrophila, Bacillus cereus, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia, were identified, increasing the risk for consumption of and exposure to these contaminated groundwaters. Additionally, antimicrobial tests revealed that many of the identified bacteria were resistant to different antibiotics. The MALDI-TOF MS results were successfully confirmed with 16S rRNA gene sequencing, proving the accuracy of this high-throughput method. Collectively, these data provide a seminal understanding of the microbial populations in contaminated groundwater overlying anthropogenic activities like unconventional oil and gas development.
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Affiliation(s)
- Misty S Martin
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX, USA
| | - Inês C Santos
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX, USA; Collaborative Laboratories for Environmental Analysis and Remediation, The University of Texas at Arlington, Arlington, TX, USA
| | - Doug D Carlton
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX, USA; Collaborative Laboratories for Environmental Analysis and Remediation, The University of Texas at Arlington, Arlington, TX, USA
| | | | - Zacariah L Hildenbrand
- Collaborative Laboratories for Environmental Analysis and Remediation, The University of Texas at Arlington, Arlington, TX, USA; Inform Environmental, LLC, Dallas, TX, USA.
| | - Kevin A Schug
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX, USA; Collaborative Laboratories for Environmental Analysis and Remediation, The University of Texas at Arlington, Arlington, TX, USA.
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Lipus D, Roy D, Khan E, Ross D, Vikram A, Gulliver D, Hammack R, Bibby K. Microbial communities in Bakken region produced water. FEMS Microbiol Lett 2018; 365:4982779. [DOI: 10.1093/femsle/fny107] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 04/20/2018] [Indexed: 01/25/2023] Open
Affiliation(s)
- Daniel Lipus
- Department of Unconventional Resources, National Energy Technology Laboratory (NETL), 626 Cochrans Mill Rd, Pittsburgh, PA 15236-0940, USA
- Oak Ridge Institute for Science and Education, 1299 Bethel Valley Rd, Oak Ridge, TN 37830, USA
- Department of Civil and Environmental Engineering, University of Pittsburgh, 742 Benedum Hall, 3700 O’Hara St., Pittsburgh, PA 15201, USA
| | - Dhritikshama Roy
- Department of Civil and Environmental Engineering, North Dakota State University, Fargo, ND 58108-6050, USA
| | - Eakalak Khan
- Department of Civil and Environmental Engineering, North Dakota State University, Fargo, ND 58108-6050, USA
- Department of Civil and Environmental Engineering and Construction, University of Nevada, Las Vegas, 4505 S. Maryland Parkway, Las Vegas, NV 89154, USA
| | - Daniel Ross
- Department of Unconventional Resources, National Energy Technology Laboratory (NETL), 626 Cochrans Mill Rd, Pittsburgh, PA 15236-0940, USA
- AECOM, 707 Grant Street, Pittsburgh, PA, 15219, USA
| | - Amit Vikram
- Department of Civil and Environmental Engineering, University of Pittsburgh, 742 Benedum Hall, 3700 O’Hara St., Pittsburgh, PA 15201, USA
| | - Djuna Gulliver
- Department of Unconventional Resources, National Energy Technology Laboratory (NETL), 626 Cochrans Mill Rd, Pittsburgh, PA 15236-0940, USA
| | - Richard Hammack
- Geosciences Division, National Energy Technology Laboratory (NETL), 626 Cochrans Mill Rd, Pittsburgh, PA 15236-0940, USA
| | - Kyle Bibby
- Oak Ridge Institute for Science and Education, 1299 Bethel Valley Rd, Oak Ridge, TN 37830, USA
- Department of Civil and Environmental Engineering, University of Pittsburgh, 742 Benedum Hall, 3700 O’Hara St., Pittsburgh, PA 15201, USA
- Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, 171 Fitzpatrick Hall, Notre Dame, IN 46556, USA
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Slipski CJ, Zhanel GG, Bay DC. Biocide Selective TolC-Independent Efflux Pumps in Enterobacteriaceae. J Membr Biol 2018; 251:15-33. [PMID: 29063140 PMCID: PMC5840245 DOI: 10.1007/s00232-017-9992-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 10/04/2017] [Indexed: 02/03/2023]
Abstract
Bacterial resistance to biocides used as antiseptics, dyes, and disinfectants is a growing concern in food preparation, agricultural, consumer manufacturing, and health care industries, particularly among Gram-negative Enterobacteriaceae, some of the most common community and healthcare-acquired bacterial pathogens. Biocide resistance is frequently associated with antimicrobial cross-resistance leading to reduced activity and efficacy of both antimicrobials and antiseptics. Multidrug resistant efflux pumps represent an important biocide resistance mechanism in Enterobacteriaceae. An assortment of structurally diverse efflux pumps frequently co-exist in these species and confer both unique and overlapping biocide and antimicrobial selectivity. TolC-dependent multicomponent systems that span both the plasma and outer membranes have been shown to confer clinically significant resistance to most antimicrobials including many biocides, however, a growing number of single component TolC-independent multidrug resistant efflux pumps are specifically associated with biocide resistance: small multidrug resistance (SMR), major facilitator superfamily (MFS), multidrug and toxin extruder (MATE), cation diffusion facilitator (CDF), and proteobacterial antimicrobial compound efflux (PACE) families. These efflux systems are a growing concern as they are rapidly spread between members of Enterobacteriaceae on conjugative plasmids and mobile genetic elements, emphasizing their importance to antimicrobial resistance. In this review, we will summarize the known biocide substrates of these efflux pumps, compare their structural relatedness, Enterobacteriaceae distribution, and significance. Knowledge gaps will be highlighted in an effort to unravel the role that these apparent "lone wolves" of the efflux-mediated resistome may offer.
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Affiliation(s)
- Carmine J Slipski
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Rm 514C Basic Medical Sciences Bldg., 745 Bannatyne Avenue, Winnipeg, MB, R3E 0J9, Canada
| | - George G Zhanel
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Rm 514C Basic Medical Sciences Bldg., 745 Bannatyne Avenue, Winnipeg, MB, R3E 0J9, Canada
| | - Denice C Bay
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Rm 514C Basic Medical Sciences Bldg., 745 Bannatyne Avenue, Winnipeg, MB, R3E 0J9, Canada.
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109
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Morán G, Ramos-Chagas G, Hugelier S, Xie X, Boudjemaa R, Ruckebusch C, Sliwa M, Darmanin T, Gaucher A, Prim D, Godeau G, Amigoni S, Guittard F, Méallet-Renault R. Superhydrophobic polypyrene films to prevent Staphylococcus aureus and Pseudomonas aeruginosa biofilm adhesion on surfaces: high efficiency deciphered by fluorescence microscopy. Photochem Photobiol Sci 2018; 17:1023-1035. [DOI: 10.1039/c8pp00043c] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Superhydrophobic fluorinated-polypyrene proved to be highly efficient to prevent biofilm adhesion.
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110
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Alotaibi SMI, Ayibiekea A, Pedersen AF, Jakobsen L, Pinholt M, Gumpert H, Hammerum AM, Westh H, Ingmer H. Susceptibility of vancomycin-resistant and -sensitive Enterococcus faecium obtained from Danish hospitals to benzalkonium chloride, chlorhexidine and hydrogen peroxide biocides. J Med Microbiol 2017; 66:1744-1751. [PMID: 29134935 DOI: 10.1099/jmm.0.000642] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
PURPOSE In Danish hospitals, the number of infections caused by vancomycin-resistant Enterococcus faecium (VRE faecium) has dramatically increased in recent years. Hospital disinfectants are essential in eliminating pathogenic microorganisms, and reduced susceptibility may contribute to hospital-associated infections. We have addressed whether clinical VRE faecium display decreased biocide susceptibility when compared to vancomycin-sensitive Enterococcus faecium (VSE faecium) isolates. METHODOLOGY In total 12 VSE faecium and 37 VRE faecium isolates obtained from Danish hospitals over an extended time period were tested for susceptibility towards three commonly applied biocides, namely benzalkonium chloride, chlorhexidine and hydrogen peroxide. RESULTS For benzalkonium chloride, 89 % of VRE faecium strains had a minimal inhibitory concentration (MIC) of 8 mg l-1, whereas for VSE faecium, only 25 % of the strains had an MIC of 8 mg l-1. For chlorhexidine, the MIC of 95 % of VRE faecium strains was 4 mg l-1 or higher, while only 33 % of VSE faecium strains displayed MIC values at the same level. In contrast, both VRE and VSE faecium displayed equal susceptibility to hydrogen peroxide, but a higher minimal bactericidal concentration (MBC) was found for the former. The efflux activity was also assessed, and this was generally higher for the VRE faecium strains compared to VSE faecium. CONCLUSION VRE faecium from Danish hospitals demonstrated decreased susceptibility towards benzalkonium chloride and chlorhexidine compared to VSE faecium, where the use of chlorhexidine is particularly heavy in the hospital environment. These findings suggest that biocide tolerance may characterize VRE faecium isolated in Danish hospitals.
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Affiliation(s)
- Sulaiman M I Alotaibi
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.,Foodborne Diseases Surveillance Center, Executive Department of Surveillance Centers & Crisis Management, Saudi Food & Drug Authority, Riyadh, Saudi Arabia
| | - Alafate Ayibiekea
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Annemette Frøling Pedersen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Lotte Jakobsen
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Mette Pinholt
- Department of Clinical Microbiology, Hvidovre University Hospital, Hvidovre, Denmark
| | - Heidi Gumpert
- Department of Clinical Microbiology, Hvidovre University Hospital, Hvidovre, Denmark
| | - Anette M Hammerum
- Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark
| | - Henrik Westh
- Department of Clinical Microbiology, Hvidovre University Hospital, Hvidovre, Denmark.,Institute of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Hanne Ingmer
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
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112
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Formation of persisters in Streptococcus mutans biofilms induced by antibacterial dental monomer. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2017; 28:178. [PMID: 28980112 DOI: 10.1007/s10856-017-5981-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Accepted: 09/01/2017] [Indexed: 02/05/2023]
Abstract
Antibacterial monomers can combat oral biofilm acids and caries; however, little is known on whether quaternary ammonium monomers (QAMs) would induce drug persistence in oral bacteria. The objectives of this study were to investigate the interactions of Streptococcus mutans (S. mutans) with dimethylaminohexadecyl methacrylate (DMAHDM), and determine for the first time whether DMAHDM could induce persisters in S. mutans. DMAHDM was synthesized using a modified Menschutkin reaction. Dose-dependent killing curves and time-dependent killing curves of planktonic S. mutans and biofilms were determined to evaluate drug persistence, using chlorhexidine (CHX) as control. The inheritability assay, minimum inhibitory concentration (MIC) and live/dead biofilm assay were determined to investigate persister characteristics. DMAHDM matched the killing potency of the gold standard CHX against S. mutans biofilms. DMAHDM and CHX induced drug persistence in S. mutans biofilms but not in planktonic bacteria. S. mutans biofilm persistence was not inheritable in that the tolerance to DMAHDM or CHX of the surviving persisters in the initial population was not transferred to subsequent generations, as displayed by the inheritability assay. The MIC of S. mutans parental strain and induced persisters remained the same. The induced persisters in S. mutans biofilms could be eliminated via higher doses of 300 μg/mL of DMAHDM and CHX. In conclusion, this study showed for the first time that (1) DMAHDM induced persisters only in biofilms, but not in planktonic bacteria; and (2) both DMAHDM-induced and CHX-induced S. mutans persister biofilms could be completely eradicated by even higher concentrations of DMAHDM and CHX. More studies are needed on the induction of persisters in oral biofilms for the development and use of a new generation of antibacterial dental monomers and resins.
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Impact of Exposure of Methicillin-Resistant Staphylococcus aureus to Polyhexanide In Vitro and In Vivo. Antimicrob Agents Chemother 2017; 61:AAC.00272-17. [PMID: 28784678 DOI: 10.1128/aac.00272-17] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 07/18/2017] [Indexed: 01/13/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) resistant to decolonization agents such as mupirocin and chlorhexidine increases the need for development of alternative decolonization molecules. The absence of reported severe adverse reactions and bacterial resistance to polyhexanide makes it an excellent choice as a topical antiseptic. In the present study, we evaluated the in vitro and in vivo capacity to generate strains with reduced polyhexanide susceptibility and cross-resistance with chlorhexidine and/or antibiotics currently used in clinic. Here we report the in vitro emergence of reduced susceptibility to polyhexanide by prolonged stepwise exposure to low concentrations in broth culture. Reduced susceptibility to polyhexanide was associated with genomic changes in the mprF and purR genes and with concomitant decreased susceptibility to daptomycin and other cell wall-active antibiotics. However, the in vitro emergence of reduced susceptibility to polyhexanide did not result in cross-resistance to chlorhexidine. During in vivo polyhexanide clinical decolonization treatment, neither reduced polyhexanide susceptibility nor chlorhexidine cross-resistance was observed. Together, these observations suggest that polyhexanide could be used safely for decolonization of carriers of chlorhexidine-resistant S. aureus strains; they also highlight the need for careful use of polyhexanide at low antiseptic concentrations.
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114
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Li P, Gu Y, Li J, Xie L, Li X, Xie J. Mycobacterium tuberculosis Major Facilitator Superfamily Transporters. J Membr Biol 2017; 250:573-585. [DOI: 10.1007/s00232-017-9982-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 08/18/2017] [Indexed: 01/26/2023]
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115
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Phenotypic chlorhexidine and triclosan susceptibility in clinical Staphylococcus aureus isolates in Australia. Pathology 2017; 49:633-637. [PMID: 28811083 DOI: 10.1016/j.pathol.2017.05.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 05/12/2017] [Accepted: 05/18/2017] [Indexed: 11/20/2022]
Abstract
Antiseptics such as chlorhexidine gluconate and triclosan are widely used in healthcare settings for both skin antisepsis and decolonisation of Staphylococcus aureus. We determined the minimum inhibitory concentration (MIC) of 198 methicillin susceptible and resistant Staphylococcus aureus clinical isolates to both chlorhexidine and triclosan using an agar dilution method. Of these, 10% (19/198) showed a raised MIC to chlorhexidine and 3% (6/198) showed an elevated MIC to triclosan. The multilocus sequence type (MLST) of each isolate was predicted using a binary method, and although ST93-MRSA-IV was the most common, ST22-MRSA-IV was shown to have statistically higher chlorhexidine MIC values compared with non ST22-MRSA-IV isolates (z = -8.7, p < 0.01). Additionally, isolates from patients known to have failed decolonisation were included and did not demonstrate elevated MIC to the decolonisation antiseptic. Monitoring for non-susceptibility of clinical isolates to biocides is important to determine trends, and may have clinical implications in terms of sub-lethal concentration in residues and concomitant antibiotic resistance.
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Tembe S, Ghosh P, Sukhi S. Influence of methylation on the bacterial efflux pump-inducing property of triclosan. J Hosp Infect 2017; 98:172-174. [PMID: 28716672 DOI: 10.1016/j.jhin.2017.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Accepted: 07/08/2017] [Indexed: 11/30/2022]
Affiliation(s)
- S Tembe
- Department of Biotechnology, Savitribai Phule Pune University, Pune, India
| | - P Ghosh
- Bioinformatics Centre, Savitribai Phule Pune University, Pune, India
| | - S Sukhi
- Department of Biotechnology, Savitribai Phule Pune University, Pune, India.
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117
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Fathima JB, Pugazhendhi A, Venis R. Synthesis and characterization of ZrO 2 nanoparticles-antimicrobial activity and their prospective role in dental care. Microb Pathog 2017; 110:245-251. [PMID: 28666841 DOI: 10.1016/j.micpath.2017.06.039] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 06/26/2017] [Accepted: 06/26/2017] [Indexed: 12/13/2022]
Abstract
Nanomaterials are exerting a pull on deal with biological and pharmaceutical applications. Biomedical grade of zirconia reveals potential mechanical features of oxide ceramics. In this study, antimicrobial activity and anti-tooth decay applications of the synthesized NPs of ZrO2 were determined. The as-prepared ZrO2 NPs were characterized by UV-vis spectroscopy, FTIR and XRD, which determined the formation of ZrO2NPs and their crystalline nature. SEM analysis further revealed spherical shaped NPs and TEM analysis determined the size of the particles in the range of 15-21 nm, respectively. The antimicrobial activity of different concentrations of the synthesized ZrO2NPs was examined against gram positive bacteria (Bacillus subtilis and Staphylococcus aureus), gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa), respectively. The synthesized ZrO2NPs displayed a better inhibitory action against Pseudomonas aeruginosa (inhibition zone size of 20 mm) at the concentration of 100 μg/ml compared to other bacteria due to the negatively charged P. aeruginosa cell wall readily attracting positively charged ZrO2NPs and thereby inhibiting microbial actions. Moreover, the concentration of ZrO2NPs was directly proportional to their inhibitory actions against the tested microorganisms. Finally, the preventive role of ZrO2NPs in a tooth decay pathway has been elucidated. Hence, it could be concluded that the as-prepared ZrO2NPs possess viable biomedical applications.
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Affiliation(s)
- John Bani Fathima
- Department of Chemistry, St. Joseph's College, Tiruchirappalli, Tamil Nadu, India
| | - Arivalagan Pugazhendhi
- Green Processing, Bioremediation and Alternative Energies Research Group (GPBAE), Faculty of Environment and Labour Safety, Ton Duc Thang University (TDTU), Ho Chi Minh City, Viet Nam.
| | - Rose Venis
- Department of Chemistry, St. Joseph's College, Tiruchirappalli, Tamil Nadu, India.
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118
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Evaluating and improving terminal hygiene practices on broiler farms to prevent Campylobacter cross-contamination between flocks. Food Microbiol 2017; 64:1-6. [DOI: 10.1016/j.fm.2016.11.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 09/26/2016] [Accepted: 11/26/2016] [Indexed: 01/31/2023]
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119
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Davis SC, Harding A, Gil J, Parajon F, Valdes J, Solis M, Higa A. Effectiveness of a polyhexanide irrigation solution on methicillin-resistant Staphylococcus aureus biofilms in a porcine wound model. Int Wound J 2017; 14:937-944. [PMID: 28266133 DOI: 10.1111/iwj.12734] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 02/01/2017] [Accepted: 02/10/2017] [Indexed: 01/22/2023] Open
Abstract
Irrigation and removal of necrotic debris can be beneficial for proper healing. It is becoming increasingly evident that wounds colonized with biofilm forming bacteria, such as Staphylococcus aureus (SA), can be more difficult to eradicate. Here we report our findings of the effects of an irrigation solution containing propyl-betaine and polyhexanide (PHMB) on methicillin-resistant Staphylococcus aureus (MRSA) biofilms in a porcine wound model. Thirty-nine deep partial thickness wounds were created with six wounds assigned to one of six treatment groups: (i) PHMB, (ii) Ringer's solution, (iii) hypochlorous acid/sodium hypochlorite, (iv) sterile water, (v) octenidine dihydrochloride, and (vi) octenilin. Wounds were inoculated with MRSA and covered with a polyurethane dressing for 24 hours to allow biofilm formation. The dressings were then removed and the wounds were irrigated twice daily for 3 days with the appropriate solution. MRSA from four wounds were recovered from each treatment group at 3 days and 6 days hours after initial treatment. Irrigation of wounds with the PHMB solution resulted in 97·85% and 99·64% reductions of MRSA at the respective 3 days and 6 days assessment times when compared to the untreated group. Both of these reductions were statistically significant compared to all other treatment groups (P values <0·05).
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Affiliation(s)
- Stephen C Davis
- Department of Dermatology & Cutaneous Surgery, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Andrew Harding
- Department of Dermatology & Cutaneous Surgery, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Joel Gil
- Department of Dermatology & Cutaneous Surgery, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Fernando Parajon
- Department of Dermatology & Cutaneous Surgery, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Jose Valdes
- Department of Dermatology & Cutaneous Surgery, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Michael Solis
- Department of Dermatology & Cutaneous Surgery, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Alex Higa
- Department of Dermatology & Cutaneous Surgery, Miller School of Medicine, University of Miami, Miami, FL, USA
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120
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In vitro antimicrobial activity of LED irradiation on Pseudomonas aeruginosa. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2017; 168:25-29. [DOI: 10.1016/j.jphotobiol.2017.01.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Accepted: 01/20/2017] [Indexed: 12/12/2022]
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121
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Tintino S, Oliveira-Tintino C, Campina F, Costa M, Cruz R, Pereira R, Andrade J, Sousa E, Siqueira-Junior J, Coutinho H, Leal-Balbino T, Balbino V. Cholesterol and ergosterol affect the activity of Staphylococcus aureus antibiotic efflux pumps. Microb Pathog 2017; 104:133-136. [DOI: 10.1016/j.micpath.2017.01.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Revised: 01/06/2017] [Accepted: 01/10/2017] [Indexed: 10/20/2022]
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122
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Sachdeva S, Palur RV, Sudhakar KU, Rathinavelan T. E. coli Group 1 Capsular Polysaccharide Exportation Nanomachinary as a Plausible Antivirulence Target in the Perspective of Emerging Antimicrobial Resistance. Front Microbiol 2017; 8:70. [PMID: 28217109 PMCID: PMC5290995 DOI: 10.3389/fmicb.2017.00070] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 01/11/2017] [Indexed: 02/02/2023] Open
Abstract
Bacteria evolving resistance against the action of multiple drugs and its ability to disseminate the multidrug resistance trait(s) across various strains of the same bacteria or different bacterial species impose serious threat to public health. Evolution of such multidrug resistance is due to the fact that, most of the antibiotics target bacterial survival mechanisms which exert selective pressure on the bacteria and aids them to escape from the action of antibiotics. Nonetheless, targeting bacterial virulence strategies such as bacterial surface associated polysaccharides biosynthesis and their surface accumulation mechanisms may be an attractive strategy, as they impose less selective pressure on the bacteria. Capsular polysaccharide (CPS) or K-antigen that is located on the bacterial surface armors bacteria from host immune response. Thus, unencapsulating bacteria would be a good strategy for drug design, besides CPS itself being a good vaccine target, by interfering with CPS biosynthesis and surface assembly pathway. Gram-negative Escherichia coli uses Wzy-polymerase dependent (Groups 1 and 4) and ATP dependent (Groups 1 and 3) pathways for CPS production. Considering E. coli as a case in point, this review explains the structure and functional roles of proteins involved in Group 1 Wzy dependent CPS biosynthesis, surface expression and anchorage in relevance to drug and vaccine developments.
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Affiliation(s)
- Shivangi Sachdeva
- Department of Biotechnology, Indian Institute of Technology Hyderabad Kandi, India
| | - Raghuvamsi V Palur
- Department of Biotechnology, Indian Institute of Technology Hyderabad Kandi, India
| | - Karpagam U Sudhakar
- Department of Biotechnology, Indian Institute of Technology Hyderabad Kandi, India
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123
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Nwuche CO, Ujam OT, Ibezim A, Ujam IB. Experimental and In-Silico Investigation of Anti-Microbial Activity of 1-Chloro-2-Isocyanatoethane Derivatives of Thiomorpholine, Piperazine and Morpholine. PLoS One 2017; 12:e0170150. [PMID: 28107379 PMCID: PMC5249067 DOI: 10.1371/journal.pone.0170150] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 12/29/2016] [Indexed: 11/20/2022] Open
Abstract
The Antibiogram properties of 1-chloro-2-isocyanatoethane derivatives of thiomorpholine (CTC), piperazine (CPC) and morpholine (CMC) were evaluated by the approved agar well diffusion, the minimum inhibitory concentration (MIC) and in silico techniques. A total of fourteen microbial cultures consisting of ten bacteria and four yeast strains were used in the biological study while affinity of the compounds for DNA gyrase, a validated antibacterial drug target, was investigated by docking method. Results indicate that both thiomorpholine and piperazine had zero activity against the Gram negative organisms tested. With morpholine, similar result was obtained except that cultures of Escherichia coli (ATCC 15442) and Salmonella typhi (ATCC 6539) presented with weak sensitivity (7-8 mm) as shown by the inhibition zone diameter (IZD) measurement. The Gram positive organisms were more sensitive to morpholine than the other compounds. The highest IZD values of 15-18 mm were achieved except for Streptococcus pneumoniae (ATCC 49619) in which mobility of the compound stopped after 12 mm. S. pneumoniae was resistant to both thiomorpholine and piperazine. The yeast strains were not sensitive to any of the studied compounds investigated. The MIC tests evaluated against a reference antibiotic show that while morpholine was most active at 4 μg.ml-1 against both B. cereus ATCC (14579) and B. subtilis, the least active compound was thiomorpholine which inhibited S. aureus (ATCC 25923) at 64 μg.ml-1. The three compounds demonstrated high affinity for the target protein (DNA gyrase) ranging from -4.63 to -5.64 Kcal/mol and even showed better ligand efficiencies than three known antibiotics; chlorobiocin, ciprofloxacin and tetracycline. This study identified the studied compounds as potential antibiotic leads with acceptable physicochemical properties and gave the molecular basis for the observed interactions between the compounds and the target protein which can be harnessed in structural optimization process.
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Affiliation(s)
- Charles O. Nwuche
- Department of Microbiology, University of Nigeria, Nsukka, Enugu State, Nigeria
- Japan International Research Center for Agricultural Sciences (JIRCAS), Tsukuba, Ibaraki, Japan
| | - Oguejiofo T. Ujam
- Department of Pure and Industrial Chemistry, University of Nigeria, Nsukka, Enugu State, Nigeria
| | - Akachukwu Ibezim
- Department of Pharmaceutical and Medicinal Chemistry, University of Nigeria, Nsukka, Enugu State, Nigeria
| | - Ifeoma B. Ujam
- Department of Pharmacognosy, University of Nigeria, Nsukka, Enugu State, Nigeria
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124
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Casado Muñoz MDC, Benomar N, Lavilla Lerma L, Knapp CW, Gálvez A, Abriouel H. Biocide tolerance, phenotypic and molecular response of lactic acid bacteria isolated from naturally-fermented Aloreña table to different physico-chemical stresses. Food Microbiol 2016; 60:1-12. [DOI: 10.1016/j.fm.2016.06.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 05/22/2016] [Accepted: 06/15/2016] [Indexed: 11/16/2022]
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125
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Virulence factors and antimicrobial resistance in Escherichia coli strains isolated from hen egg shells. Int J Food Microbiol 2016; 238:89-95. [DOI: 10.1016/j.ijfoodmicro.2016.08.037] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 08/14/2016] [Accepted: 08/28/2016] [Indexed: 01/24/2023]
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126
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Wu D, Lu R, Chen Y, Qiu J, Deng C, Tan Q. Study of cross-resistance mediated by antibiotics, chlorhexidine and Rhizoma coptidis in Staphylococcus aureus. J Glob Antimicrob Resist 2016; 7:61-66. [DOI: 10.1016/j.jgar.2016.07.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 07/19/2016] [Accepted: 07/25/2016] [Indexed: 10/21/2022] Open
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127
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Lee LF, Mariappan V, Vellasamy KM, Lee VS, Vadivelu J. Antimicrobial activity of Tachyplesin 1 against Burkholderia pseudomallei: an in vitro and in silico approach. PeerJ 2016; 4:e2468. [PMID: 27812400 PMCID: PMC5088614 DOI: 10.7717/peerj.2468] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 08/21/2016] [Indexed: 11/20/2022] Open
Abstract
Burkholderia pseudomallei, the causative agent of melioidosis, is intrinsically resistant to many conventional antibiotics. Therefore, alternative antimicrobial agents such as antimicrobial peptides (AMPs) are extensively studied to combat this issue. Our study aims to identify and understand the mode of action of the potential AMP(s) that are effective against B. pseudomallei in both planktonic and biofilm state as well as to predict the possible binding targets on using in vitro and in silico approaches. In the in vitro study, 11 AMPs were tested against 100 B. pseudomallei isolates for planktonic cell susceptibility, where LL-37, and PG1, demonstrated 100.0% susceptibility and TP1 demonstrated 83% susceptibility. Since the B. pseudomallei activity was reported on LL-37 and PG1, TP1 was selected for further investigation. TP1 inhibited B. pseudomallei cells at 61.69 μM, and membrane blebbing was observed using scanning electron microscopy. Moreover, TP1 inhibited B. pseudomallei cell growth, reaching bactericidal endpoint within 2 h post exposure as compared to ceftazidime (CAZ) (8 h). Furthermore, TP1 was shown to suppress the growth of B. pseudomallei cells in biofilm state at concentrations above 221 μM. However, TP1 was cytotoxic to the mammalian cell lines tested. In the in silico study, molecular docking revealed that TP1 demonstrated a strong interaction to the common peptide or inhibitor binding targets for lipopolysaccharide of Escherichia coli, as well as autolysin, pneumolysin, and pneumococcal surface protein A (PspA) of Streptococcus pneumoniae. Homology modelled B. pseudomallei PspA protein (YDP) also showed a favourable binding with a strong electrostatic contribution and nine hydrogen bonds. In conclusion, TP1 demonstrated a good potential as an anti-B. pseudomallei agent.
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Affiliation(s)
- Lyn-Fay Lee
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
| | - Vanitha Mariappan
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
| | - Kumutha Malar Vellasamy
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
| | - Vannajan Sanghiran Lee
- Department of Chemistry, Faculty of Science, University of Malaya , Kuala Lumpur , Malaysia
| | - Jamuna Vadivelu
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya , Kuala Lumpur , Malaysia
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128
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Lin W, Zhang M, Zhang S, Yu X. Can chlorination co-select antibiotic-resistance genes? CHEMOSPHERE 2016; 156:412-419. [PMID: 27192478 DOI: 10.1016/j.chemosphere.2016.04.139] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 04/26/2016] [Accepted: 04/27/2016] [Indexed: 06/05/2023]
Abstract
Selective pressures, such as chemical or heavy metal pollution, may co-select for bacterial antibiotic resistance in the environment. However, whether chlorination in water treatment can co-select antibiotic-resistant bacteria is controversial. In this study, high capacity quantitative polymerase chain reaction (qPCR) analysis was applied to target almost all known antibiotic-resistance genes (ARGs) (282 types) and 13 mobile genetic elements (MGEs) in bacteria detected in secondary effluents from a municipal wastewater treatment plant after chlorination. The results revealed that 125 unique ARGs were detected in non-chlorinated samples, and the number decreased (79-91 types) as the chlorine concentration was increased. Moreover, 7.49 × 10(4)-3.92 × 10(7) copies/100 ml water reduction of ARGs occurred with 4 mg Cl2/l. Considering the relative abundance of ARGs (i.e., ARG copies normalized to 16S rRNA gene copies), 119 ARGs decreased in response to chlorination, whereas only six ARGs, such as dfrA1, tetPB-03, tetPA, ampC-04, tetA-02, and erm(36), were potentially enriched by 10.90-, 10.06-, 8.63-, 6.86-, 3.77-, and 1.09-fold, respectively. Furthermore, the relative abundance of 12 detected MGEs was lower after chlorination. Therefore, chlorination was effective in reducing ARGs and MGEs rather than co-selecting them.
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Affiliation(s)
- Wenfang Lin
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Menglu Zhang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Shenghua Zhang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
| | - Xin Yu
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China.
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129
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Gupta SK, Gross R, Dandekar T. An antibiotic target ranking and prioritization pipeline combining sequence, structure and network-based approaches exemplified for Serratia marcescens. Gene 2016; 591:268-278. [PMID: 27425866 DOI: 10.1016/j.gene.2016.07.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 06/26/2016] [Accepted: 07/12/2016] [Indexed: 01/20/2023]
Abstract
We investigate a drug target screening pipeline comparing sequence, structure and network-based criteria for prioritization. Serratia marcescens, an opportunistic pathogen, serves as test case. We rank according to (i) availability of three dimensional structures and lead compounds, (ii) not occurring in man and general sequence conservation information, and (iii) network information on the importance of the protein (conserved protein-protein interactions; metabolism; reported to be an essential gene in other organisms). We identify 45 potential anti-microbial drug targets in S. marcescens with KdsA involved in LPS biosynthesis as top candidate drug target. LpxC and FlgB are further top-ranked targets identified by interactome analysis not suggested before for S. marcescens. Pipeline, targets and complementarity of the three approaches are evaluated by available experimental data and genetic evidence and against other antibiotic screening pipelines. This supports reliable drug target identification and prioritization for infectious agents (bacteria, parasites, fungi) by these bundled complementary criteria.
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Affiliation(s)
- Shishir K Gupta
- Department of Bioinformatics, Biocenter, Am Hubland, D-97074 Würzburg, Germany; Department of Microbiology, Biocenter, Am Hubland, D-97074 Würzburg, Germany.
| | - Roy Gross
- Department of Microbiology, Biocenter, Am Hubland, D-97074 Würzburg, Germany.
| | - Thomas Dandekar
- Department of Bioinformatics, Biocenter, Am Hubland, D-97074 Würzburg, Germany; EMBL Heidelberg, BioComputing Unit, Meyerhofstraße 1, 69117 Heidelberg, Germany.
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130
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Tseng CC, Tsai YH, Hu A, Liou JW, Chang KC, Chang HH. Altered susceptibility to the bactericidal effect of photocatalytic oxidation by TiO2 is related to colistin resistance development in Acinetobacter baumannii. Appl Microbiol Biotechnol 2016; 100:8549-61. [DOI: 10.1007/s00253-016-7654-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Revised: 05/24/2016] [Accepted: 05/27/2016] [Indexed: 10/21/2022]
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131
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Khameneh B, Diab R, Ghazvini K, Fazly Bazzaz BS. Breakthroughs in bacterial resistance mechanisms and the potential ways to combat them. Microb Pathog 2016; 95:32-42. [DOI: 10.1016/j.micpath.2016.02.009] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2015] [Revised: 02/07/2016] [Accepted: 02/17/2016] [Indexed: 12/17/2022]
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132
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Li Z, Tang XZ, Zhu W, Thompson BC, Huang M, Yang J, Hu X, Khor KA. Single-Step Process toward Achieving Superhydrophobic Reduced Graphene Oxide. ACS APPLIED MATERIALS & INTERFACES 2016; 8:10985-10994. [PMID: 27064825 DOI: 10.1021/acsami.6b01227] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We report the first use of spark plasma sintering (SPS) as a single-step process to achieve superhydrophobic reduced graphene oxide (rGO). It was found that SPS was capable of converting smooth and electrically insulating graphene oxide (GO) sheets into highly electrically conductive rGO with minimum residual oxygen and hierarchical roughness which could be well retained after prolonged ultrasonication. At a temperature of 500 °C, which is lower than the conventional critical temperature for GO exfoliation, GO was successfully exfoliated, reduced, and hierarchically roughened. rGO fabricated by only 1 min of treatment at 1050 °C was superhydrophobic with a surface roughness (Ra) 10 times as large as that of GO as well as an extraordinarily high C:O ratio of 83.03 (atom %) and water contact angle of 153°. This demonstrates that SPS is a superior GO reduction technique, which enabled superhydrophobic rGO to be quickly and effectively achieved in one single step. Moreover, the superhydrophobic rGO fabricated by SPS showed an impressive bacterial antifouling and inactivation effect against Escherichia coli in both aqueous solution and the solid state. It is envisioned that the superhydrophobic rGO obtained in this study can be potentially used for a wide range of industrial and biomedical applications, such as the fabrication of self-cleaning and antibacterial surfaces.
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Affiliation(s)
- Zhong Li
- School of Mechanical & Aerospace Engineering, ‡School of Civil & Environmental Engineering, and §School of Materials Science & Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798
| | - Xiu-Zhi Tang
- School of Mechanical & Aerospace Engineering, ‡School of Civil & Environmental Engineering, and §School of Materials Science & Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798
| | - Wenyu Zhu
- School of Mechanical & Aerospace Engineering, ‡School of Civil & Environmental Engineering, and §School of Materials Science & Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798
| | - Brianna C Thompson
- School of Mechanical & Aerospace Engineering, ‡School of Civil & Environmental Engineering, and §School of Materials Science & Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798
| | - Mingyue Huang
- School of Mechanical & Aerospace Engineering, ‡School of Civil & Environmental Engineering, and §School of Materials Science & Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798
| | - Jinglei Yang
- School of Mechanical & Aerospace Engineering, ‡School of Civil & Environmental Engineering, and §School of Materials Science & Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798
| | - Xiao Hu
- School of Mechanical & Aerospace Engineering, ‡School of Civil & Environmental Engineering, and §School of Materials Science & Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798
| | - Khiam Aik Khor
- School of Mechanical & Aerospace Engineering, ‡School of Civil & Environmental Engineering, and §School of Materials Science & Engineering, Nanyang Technological University , 50 Nanyang Avenue, Singapore 639798
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133
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McLain JE, Cytryn E, Durso LM, Young S. Culture-based Methods for Detection of Antibiotic Resistance in Agroecosystems: Advantages, Challenges, and Gaps in Knowledge. JOURNAL OF ENVIRONMENTAL QUALITY 2016; 45:432-40. [PMID: 27065389 DOI: 10.2134/jeq2015.06.0317] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Various culture-based methodologies are used in assessment of antibiotic resistance in samples collected in agroecosystems. Culture-based methods commonly involve isolating target bacteria on general or selective media and assessing growth in response to specific concentrations of antibiotics. The advantages of culture-based methods are multifold. In particular, isolation of bacteria is key to understanding phenotypic characteristics of isolates and their resistance patterns, and most national and international antibiotic resistance monitoring projects are isolate based. This review covers current knowledge of bacterial groups and antibiotics commonly targeted in resistance studies using bacterial culture and discusses the range in methods used, data interpretation, and factors supporting and confounding the use of culture-based methods in assessment of antibiotic resistance. Gaps in knowledge related to study design and resistance databases are discussed. Finally, a case is made for the integration of culture-based and molecular methods to better inform our understanding of antibiotic resistance in agroecosystems.
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134
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Kitagawa H, Izutani N, Kitagawa R, Maezono H, Yamaguchi M, Imazato S. Evolution of resistance to cationic biocides in Streptococcus mutans and Enterococcus faecalis. J Dent 2016; 47:18-22. [PMID: 26904979 DOI: 10.1016/j.jdent.2016.02.008] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 02/08/2016] [Accepted: 02/17/2016] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVES The aim of this study was to investigate whether Streptococcus mutans and Enterococcus faecalis develop resistance to the cationic biocides chlorhexidine (CHX), cetylpyridinium chloride (CPC), and 12-methacryloyloxydodecylpyridinium bromide (MDPB). METHODS The minimum inhibitory concentrations (MICs) of CHX, CPC, and MDPB were assessed after repeated exposure of S. mutans and E. faecalis to these biocides. Cell-surface hydrophobicity and protein expression profiles of bacterial cells were examined to elucidate possible resistance mechanisms. RESULTS The MIC of CHX against E. faecalis showed constant increases up to 10 passages. No changes in the MICs of CPC and MDPB against E. faecalis were observed. The MICs of CHX, CPC, and MDPB against S. mutans did not increase. The surface hydrophobicity of E. faecalis significantly increased with increasing exposure to CHX and CPC. However, changes in protein expression profiles were only found in CHX-adapted E. faecalis, as evidenced by the emergence of a novel, approximately 19-kDa band following sodium dodecyl sulfate-polyacrylamide gel electrophoresis. CONCLUSIONS While E. faecalis and S. mutans did not exhibit increased resistance to CPC or MDPB, repeated exposure of E. faecalis to CHX led to resistance. It is likely that the acquisition of resistance is related to an altered protein composition. CLINICAL SIGNIFICANCE Alkyl pyridinium compounds, such as CPC and MDPB, could have a lower risk to cause adaptation of E. faecalis, which is advantageous compared with CHX.
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Affiliation(s)
- Haruaki Kitagawa
- Department of Biomaterials Science, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan.
| | - Naomi Izutani
- Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - Ranna Kitagawa
- Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - Hazuki Maezono
- Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - Mikiyo Yamaguchi
- Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
| | - Satoshi Imazato
- Department of Biomaterials Science, Osaka University Graduate School of Dentistry, Suita, Osaka, Japan
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135
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Dzotam JK, Touani FK, Kuete V. Antibacterial and antibiotic-modifying activities of three food plants (Xanthosoma mafaffa Lam., Moringa oleifera (L.) Schott and Passiflora edulis Sims) against multidrug-resistant (MDR) Gram-negative bacteria. Altern Ther Health Med 2016; 16:9. [PMID: 26753836 PMCID: PMC4709887 DOI: 10.1186/s12906-016-0990-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 01/08/2016] [Indexed: 11/25/2022]
Abstract
Background The present study was designed to investigate the antibacterial activities of the methanol extract of three edible plants, namely Xanthosoma mafaffa, Moringa oleifera and Passiflora edulis and their synergistic effects with some commonly used antibiotics against MDR Gram-negative bacteria expressing active efflux pumps. Methods Broth microdilution method was used to determine the minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) of the extracts, as well as those of antibiotics in association with the extracts. Results The phytochemical test indicate that all tested crude extracts contained polyphenols, triterpenes and steroids whilst other phytochemical classes were selectively distributed. Extracts showed antibacterial activities with minimum inhibitory concentrations ranging from 128-1024 μg/mL on the majority of the 19 tested Gram-negative bacterial strains. Extract from the pericarp of P. edulis inhibited the growth of 89.5 % of the 19 tested bacterial strains, the lowest minimal inhibitory concentration (MIC) value of 128 μg/mL being recorded against Escherichia coli AG100 strain. In the presence of Phenylalanine-Arginine β-Naphtylamide (PAβN)], an efflux pump inhibitor (EPI), the activity of the extract from X. mafaffa increased on 40 % of tested strains. In combination with antibiotics, extracts of X. mafaffa, M. oleifera and pericarp of P. edulis showed synergistic effects with some antibiotics against more than 75 % of the tested bacteria. Conclusion The results of the present study indicate that the tested plants may be used in the treatment of bacterial infections including the multi-resistant bacteria.
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136
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Liu KY, Yang WH, Dong XK, Cong LM, Li N, Li Y, Wen ZB, Yin Z, Lan ZJ, Li WP, Li JS. Inhalation Study of Mycobacteriophage D29 Aerosol for Mice by Endotracheal Route and Nose-Only Exposure. J Aerosol Med Pulm Drug Deliv 2016; 29:393-405. [PMID: 26745146 DOI: 10.1089/jamp.2015.1233] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
BACKGROUND Lytic mycobacteriophage D29 has the potential for tuberculosis treatment including multidrug-resistant strains. The aims of this study are to investigate deposition and distribution of aerosolized phage D29 particles in naive Balb/C mice, together with pharmacokinetics and evaluation of acute lung injury. METHODS Pharmacokinetics and BALF (bronchoalveolar lavage fluids) were analyzed after administration of phage D29 aerosols by endotracheal route using Penn-century aerosolizer; Collison 6-jet and Spinning top aerosol nebulizers (STAG) were used to generate phage aerosols with different particle size distributions in nose-only inhalation experiments. After exposure, deposited amounts of phage D29 particles in respiratory tracts were measured, and deposition efficiencies were calculated. A typical path deposition model for mice was developed, and then comparisons were made between predictions and experimentally measured results. RESULTS Approximately 10% of aerosolized phages D29 reached lung of mouse for pulmonary delivery, and were completely eliminated until 72 h after administration. In contrast, about 0.1% of intraperitoneal injected phages reached the lung, and were almost eliminated at 12 h time point. The inflammation was hardly observed in lung according to the results of BALF analysis. The CMADs (count median aerodynamic diameters) of generated aerosol by Collison and STAG nebulizer were 0.8 μm and 1.5 μm, respectively. After nose-only exposure, measured deposition efficiencies in whole respiratory tract for 0.8 and 1.5 μm phage particles were below 1% and 10%, respectively. Predictions of the computer deposition model compared fairly well with experimentally measured results. CONCLUSIONS This is the first systematic study of phage D29 aerosol respiratory challenge in laboratory animals. It provides evidence that aerosol delivery of phage D29 is an effective way for treating pulmonary infections caused by Mycobacterium tuberculosis. This research will also provide important data for future inhalation experiments.
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Affiliation(s)
- Ke-Yang Liu
- 1 Tongzhou Institute of Infectious Diseases and Epidemiology , Beijing, China .,2 State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology , Beijing, China
| | - Wen-Hui Yang
- 2 State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology , Beijing, China
| | - Xiao-Kai Dong
- 2 State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology , Beijing, China
| | - Li-Ming Cong
- 1 Tongzhou Institute of Infectious Diseases and Epidemiology , Beijing, China
| | - Na Li
- 2 State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology , Beijing, China
| | - Yun Li
- 3 College of Veterinary Medicine, Nanjing Agricultural University , Nanjing, China
| | - Zhan-Bo Wen
- 2 State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology , Beijing, China
| | - Zhe Yin
- 2 State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology , Beijing, China
| | - Zhi-Jie Lan
- 1 Tongzhou Institute of Infectious Diseases and Epidemiology , Beijing, China
| | - Wei-Peng Li
- 1 Tongzhou Institute of Infectious Diseases and Epidemiology , Beijing, China
| | - Jin-Song Li
- 2 State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology , Beijing, China
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137
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Antibacterial Activity of Alanine-Derived Gemini Quaternary Ammonium Compounds. J SURFACTANTS DETERG 2015; 19:275-282. [PMID: 26949329 PMCID: PMC4764639 DOI: 10.1007/s11743-015-1778-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 12/08/2015] [Indexed: 01/21/2023]
Abstract
The antibacterial activity of alanine-derived gemini quaternary ammonium salts (chlorides and bromides) with various spacer and alkyl chain lengths was investigated. The studied compounds exhibited a strong bactericidal effect, especially bromides with 10 and 12 carbon alkyl chains and 3 carbon spacer groups (TMPAL-10 Br and TMPAL-12 Br), with a short contact time. Both salts dislodged biofilms of Pseudomonas aeruginosa and Staphylococcus epidermidis, and were lethal to adherent cells of S. epidermidis. Bromide with 2 carbon spacer groups and 12 carbon alkyl chains (TMEAL-12 Br) effectively reduced microbial adhesion by coating polystyrene and silicone surfaces. The results obtained suggest that, after further studies, gemini QAS might be considered as antimicrobial agents in medicine or industry.
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138
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Diribe O, Thomas S, AbuOun M, Fitzpatrick N, La Ragione R. Genotypic relatedness and characterization of Staphylococcus pseudintermedius associated with post-operative surgical infections in dogs. J Med Microbiol 2015; 64:1074-1081. [PMID: 26449388 DOI: 10.1099/jmm.0.000110] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Staphylococcus pseudintermedius is a commensal organism of dogs that can also be implicated in surgical site infections (SSIs) in dogs. Particularly with the recent emergence and spread of the ST71-t02-SCCmecII-III multidrug-resistant S. pseudintermedius clonal lineage (MDRSP), it is important to understand the clonal diversity of S. pseudintermedius in SSIs in dogs. The study reported here investigated the genotypic relatedness of 124 S. pseudintermedius isolates from the surgical wounds of 90 dogs admitted to a referral practice in the UK. This study also aimed to understand whether MDRSP is better adapted to survival and persistence in different environments compared with other S. pseudintermedius. Whilst no individual S. pseudintermedius clonal type was primarily responsible for S. pseudintermedius-associated SSIs in dogs, we found that MDRSP was the most represented clonal type among the isolates studied. However, we observed no difference in the level of biofilm production, susceptibility to biocides or carriage of specific virulence determinants between MDRSP and other S. pseudintermedius isolates studied. Interestingly, in the competitive fitness study, MDRSP did not outcompete any member of the other S. pseudintermedius isolates studied in each environment. Our data suggest that the determinants that promote S. pseudintermedius-associated SSIs in dogs are distributed among S. pseudintermedius as a species and are not restricted to a few clonal types. They also provide evidence to support the suggestion that MDRSP is not better adapted to survival or persistence in different environments and is no more virulent than other S. pseudintermedius isolates.
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Affiliation(s)
- Onyinye Diribe
- Animal and Plant Health Agency, Weybridge, Surrey, UK.,Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK
| | - Sarah Thomas
- Animal and Plant Health Agency, Weybridge, Surrey, UK
| | - Manal AbuOun
- Animal and Plant Health Agency, Weybridge, Surrey, UK
| | - Noel Fitzpatrick
- Fitzpatrick Referrals, Halfway Lane, Godalming, Surrey, UK.,Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK
| | - Roberto La Ragione
- Animal and Plant Health Agency, Weybridge, Surrey, UK.,Faculty of Health and Medical Sciences, University of Surrey, Guildford, Surrey, UK
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139
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Co-Selection of Resistance to Antibiotics, Biocides and Heavy Metals, and Its Relevance to Foodborne Pathogens. Antibiotics (Basel) 2015; 4:567-604. [PMID: 27025641 PMCID: PMC4790313 DOI: 10.3390/antibiotics4040567] [Citation(s) in RCA: 217] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 11/05/2015] [Accepted: 11/06/2015] [Indexed: 02/07/2023] Open
Abstract
Concerns have been raised in recent years regarding co-selection for antibiotic resistance among bacteria exposed to biocides used as disinfectants, antiseptics and preservatives, and to heavy metals (particularly copper and zinc) used as growth promoters and therapeutic agents for some livestock species. There is indeed experimental and observational evidence that exposure to these non-antibiotic antimicrobial agents can induce or select for bacterial adaptations that result in decreased susceptibility to one or more antibiotics. This may occur via cellular mechanisms that are protective across multiple classes of antimicrobial agents or by selection of genetic determinants for resistance to non-antibiotic agents that are linked to genes for antibiotic resistance. There may also be relevant effects of these antimicrobial agents on bacterial community structure and via non-specific mechanisms such as mobilization of genetic elements or mutagenesis. Notably, some co-selective adaptations have adverse effects on fitness in the absence of a continued selective pressure. The present review examines the evidence for the significance of these phenomena, particularly in respect of bacterial zoonotic agents that commonly occur in livestock and that may be transmitted, directly or via the food chain, to human populations.
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140
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El Zowalaty ME, Al Thani AA, Webster TJ, El Zowalaty AE, Schweizer HP, Nasrallah GK, Marei HE, Ashour HM. Pseudomonas aeruginosa: arsenal of resistance mechanisms, decades of changing resistance profiles, and future antimicrobial therapies. Future Microbiol 2015; 10:1683-706. [PMID: 26439366 DOI: 10.2217/fmb.15.48] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Antimicrobial resistance is one of the most serious public health issues facing humans since the discovery of antimicrobial agents. The frequent, prolonged, and uncontrolled use of antimicrobial agents are major factors in the emergence of antimicrobial-resistant bacterial strains, including multidrug-resistant variants. Pseudomonas aeruginosa is a leading cause of nosocomial infections. The abundant data on the increased resistance to antipseudomonal agents support the need for global action. There is a paucity of new classes of antibiotics active against P. aeruginosa. Here, we discuss recent antibacterial resistance profiles and mechanisms of resistance by P. aeruginosa. We also review future potential methods for controlling antibiotic-resistant bacteria, such as phage therapy, nanotechnology and antipseudomonal vaccines.
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Affiliation(s)
- Mohamed E El Zowalaty
- Department of Microbiology & Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA.,BioMedical Research Center, Qatar University, Doha, PO Box 2713, Qatar
| | - Asmaa A Al Thani
- BioMedical Research Center, Qatar University, Doha, PO Box 2713, Qatar.,Department of Health Sciences, College of Arts and Sciences, Qatar University, Doha 2713, Qatar
| | - Thomas J Webster
- Department of Chemical Engineering, Northeastern University, Boston, MA 02018, USA.,Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia
| | - Ahmed E El Zowalaty
- Department of Physiology & Pharmacology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA.,Interdisciplinary Toxicology Program, University of Georgia, Athens, GA 30602, USA
| | - Herbert P Schweizer
- Department of Molecular Genetics & Microbiology, College of Medicine, University of Florida, Gainesville, FL 32611, USA.,Emerging Pathogens Institute, Institute for Therapeutic Innovation, University of Florida Gainesville, FL 32611, USA
| | - Gheyath K Nasrallah
- BioMedical Research Center, Qatar University, Doha, PO Box 2713, Qatar.,Department of Health Sciences, College of Arts and Sciences, Qatar University, Doha 2713, Qatar
| | - Hany E Marei
- BioMedical Research Center, Qatar University, Doha, PO Box 2713, Qatar
| | - Hossam M Ashour
- Department of Microbiology & Immunology, Faculty of Pharmacy, Cairo University, Egypt.,Department of Pharmacy Practice, Eugene Applebaum College of Pharmacy & Health Sciences, Wayne State University, Detroit, MI, USA
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141
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Engineering the central biosynthetic and secondary metabolic pathways of Pseudomonas aeruginosa strain PA1201 to improve phenazine-1-carboxylic acid production. Metab Eng 2015; 32:30-38. [PMID: 26369437 DOI: 10.1016/j.ymben.2015.09.003] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 08/10/2015] [Accepted: 09/02/2015] [Indexed: 11/24/2022]
Abstract
The secondary metabolite phenazine-1-carboxylic acid (PCA) is an important component of the newly registered biopesticide Shenqinmycin. We used a combined method involving gene, promoter, and protein engineering to modify the central biosynthetic and secondary metabolic pathways in the PCA-producing Pseudomonas aeruginosa strain PA1201. The PCA yield of the resulting strain PA-IV was increased 54.6-fold via the following strategies: (1) blocking PCA conversion and enhancing PCA efflux pumping; (2) increasing metabolic flux towards the PCA biosynthetic pathway through the over-production of two DAHP synthases and blocking the synthesis of 21 secondary metabolites; (3) increasing the PCA precursor supply through the engineering of five chorismate-utilizing enzymes; (4) engineering the promoters of two PCA biosynthetic gene clusters. Strain PA-IV produced 9882 mg/L PCA in fed-batch fermentation, which is twice as much as that produced by the current industrial strain. Strain PA-IV was also genetically stable and comparable to Escherichia coli in cytotoxicity.
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142
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Zhou G, Shi QS, Huang XM, Xie XB. The Three Bacterial Lines of Defense against Antimicrobial Agents. Int J Mol Sci 2015; 16:21711-33. [PMID: 26370986 PMCID: PMC4613276 DOI: 10.3390/ijms160921711] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 08/21/2015] [Accepted: 08/31/2015] [Indexed: 01/06/2023] Open
Abstract
Antimicrobial agents target a range of extra- and/or intracellular loci from cytoplasmic wall to membrane, intracellular enzymes and genetic materials. Meanwhile, many resistance mechanisms employed by bacteria to counter antimicrobial agents have been found and reported in the past decades. Based on their spatially distinct sites of action and distribution of location, antimicrobial resistance mechanisms of bacteria were categorized into three groups, coined the three lines of bacterial defense in this review. The first line of defense is biofilms, which can be formed by most bacteria to overcome the action of antimicrobial agents. In addition, some other bacteria employ the second line of defense, the cell wall, cell membrane, and encased efflux pumps. When antimicrobial agents permeate the first two lines of defense and finally reach the cytoplasm, many bacteria will make use of the third line of defense, including alterations of intracellular materials and gene regulation to protect themselves from harm by bactericides. The presented three lines of defense theory will help us to understand the bacterial resistance mechanisms against antimicrobial agents and design efficient strategies to overcome these resistances.
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Affiliation(s)
- Gang Zhou
- Guangdong Institute of Microbiology, Guangzhou 510070, Guangdong, China.
- State Key Laboratory of Applied Microbiology Southern China, Guangzhou 510070, Guangdong, China.
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangzhou 510070, Guangdong, China.
| | - Qing-Shan Shi
- Guangdong Institute of Microbiology, Guangzhou 510070, Guangdong, China.
- State Key Laboratory of Applied Microbiology Southern China, Guangzhou 510070, Guangdong, China.
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangzhou 510070, Guangdong, China.
| | - Xiao-Mo Huang
- Guangdong Institute of Microbiology, Guangzhou 510070, Guangdong, China.
- State Key Laboratory of Applied Microbiology Southern China, Guangzhou 510070, Guangdong, China.
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangzhou 510070, Guangdong, China.
| | - Xiao-Bao Xie
- Guangdong Institute of Microbiology, Guangzhou 510070, Guangdong, China.
- State Key Laboratory of Applied Microbiology Southern China, Guangzhou 510070, Guangdong, China.
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangzhou 510070, Guangdong, China.
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143
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De Silva M, Ning C, Ghanbar S, Zhanel G, Logsetty S, Liu S, Kumar A. Evidence that a novel quaternary compound and its organic N-chloramine derivative do not select for resistant mutants of Pseudomonas aeruginosa. J Hosp Infect 2015; 91:53-8. [PMID: 26122622 DOI: 10.1016/j.jhin.2015.05.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 05/12/2015] [Indexed: 01/17/2023]
Abstract
BACKGROUND Pseudomonas aeruginosa is well known for causing hospital-acquired infections that are often difficult to treat because of its high intrinsic and acquired resistance to antibiotics. Resistance-nodulation-division (RND) efflux pumps are the major contributors to the intrinsic multidrug resistance (MDR) in this organism. Various biocides used in hospital settings have been shown to select for RND-pump-overexpressing mutants of P. aeruginosa that show cross-resistance to clinically relevant antibiotics. Therefore, finding biocides that do not select for multidrug-resistant mutants is important in controlling the spread of bacteria such as P. aeruginosa. AIM To evaluate the potential of a novel quaternary ammonium compound and its N-chloramine derivative in selecting for MDR mutants of P. aeruginosa. METHODS P. aeruginosa PA01 was cultured in the presence of increasing concentrations of the quaternary ammonium compound and its N-chloramine derivative respectively, and one mutant each selected. Susceptibility of the mutants to both compounds as well as antibiotics was tested. Susceptibility of P. aeruginosa strains with deletions in RND pumps was also tested for both compounds to determine whether they are a substrate of these pumps. Expression of mexB, mexD, and mexY genes in the mutants was analysed using quantitative reverse transcriptase-polymerase chain reaction to determine whether the compounds can select for pump-overexpressing mutants. FINDINGS We show that whereas both compounds can be pumped by the MexCD-OprJ pump, they neither select for mutants that overexpress RND pumps nor for mutants that display cross-resistance to antibiotics. CONCLUSION These compounds are promising candidates to be used as disinfectants in hospital settings.
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Affiliation(s)
- M De Silva
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - C Ning
- Department of Textile Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - S Ghanbar
- Department of Chemistry, University of Manitoba, Winnipeg, MB, Canada
| | - G Zhanel
- Department of Medical Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - S Logsetty
- Department of Surgery, University of Manitoba, Winnipeg, MB, Canada
| | - S Liu
- Department of Textile Sciences, University of Manitoba, Winnipeg, MB, Canada; Department of Chemistry, University of Manitoba, Winnipeg, MB, Canada; Department of Medical Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - A Kumar
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada; Department of Medical Microbiology, University of Manitoba, Winnipeg, MB, Canada.
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144
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Anes J, McCusker MP, Fanning S, Martins M. The ins and outs of RND efflux pumps in Escherichia coli. Front Microbiol 2015; 6:587. [PMID: 26113845 PMCID: PMC4462101 DOI: 10.3389/fmicb.2015.00587] [Citation(s) in RCA: 162] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Accepted: 05/28/2015] [Indexed: 11/13/2022] Open
Abstract
Infectious diseases remain one of the principal causes of morbidity and mortality in the world. Relevant authorities including the WHO and CDC have expressed serious concern regarding the continued increase in the development of multidrug resistance among bacteria. They have also reaffirmed the urgent need for investment in the discovery and development of new antibiotics and therapeutic approaches to treat multidrug resistant (MDR) bacteria. The extensive use of antimicrobial compounds in diverse environments, including farming and healthcare, has been identified as one of the main causes for the emergence of MDR bacteria. Induced selective pressure has led bacteria to develop new strategies of defense against these chemicals. Bacteria can accomplish this by several mechanisms, including enzymatic inactivation of the target compound; decreased cell permeability; target protection and/or overproduction; altered target site/enzyme and increased efflux due to over-expression of efflux pumps. Efflux pumps can be specific for a single substrate or can confer resistance to multiple antimicrobials by facilitating the extrusion of a broad range of compounds including antibiotics, heavy metals, biocides and others, from the bacterial cell. To overcome antimicrobial resistance caused by active efflux, efforts are required to better understand the fundamentals of drug efflux mechanisms. There is also a need to elucidate how these mechanisms are regulated and how they respond upon exposure to antimicrobials. Understanding these will allow the development of combined therapies using efflux inhibitors together with antibiotics to act on Gram-negative bacteria, such as the emerging globally disseminated MDR pathogen Escherichia coli ST131 (O25:H4). This review will summarize the current knowledge on resistance-nodulation-cell division efflux mechanisms in E. coli, a bacteria responsible for community and hospital-acquired infections, as well as foodborne outbreaks worldwide.
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Affiliation(s)
- João Anes
- UCD Centre for Food Safety, School of Public Health, Physiotherapy and Population Science, UCD Centre for Molecular Innovation and Drug Discovery, University College Dublin Dublin, Ireland
| | - Matthew P McCusker
- UCD Centre for Food Safety, School of Public Health, Physiotherapy and Population Science, UCD Centre for Molecular Innovation and Drug Discovery, University College Dublin Dublin, Ireland
| | - Séamus Fanning
- UCD Centre for Food Safety, School of Public Health, Physiotherapy and Population Science, UCD Centre for Molecular Innovation and Drug Discovery, University College Dublin Dublin, Ireland
| | - Marta Martins
- UCD Centre for Food Safety, School of Public Health, Physiotherapy and Population Science, UCD Centre for Molecular Innovation and Drug Discovery, University College Dublin Dublin, Ireland
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145
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146
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Efflux as a glutaraldehyde resistance mechanism in Pseudomonas fluorescens and Pseudomonas aeruginosa biofilms. Antimicrob Agents Chemother 2015; 59:3433-40. [PMID: 25824217 DOI: 10.1128/aac.05152-14] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 03/21/2015] [Indexed: 01/13/2023] Open
Abstract
A major challenge in microbial biofilm control is biocide resistance. Phenotypic adaptations and physical protective effects have been historically thought to be the primary mechanisms for glutaraldehyde resistance in bacterial biofilms. Recent studies indicate the presence of genetic mechanisms for glutaraldehyde resistance, but very little is known about the contributory genetic factors. Here, we demonstrate that efflux pumps contribute to glutaraldehyde resistance in Pseudomonas fluorescens and Pseudomonas aeruginosa biofilms. The RNA-seq data show that efflux pumps and phosphonate degradation, lipid biosynthesis, and polyamine biosynthesis metabolic pathways were induced upon glutaraldehyde exposure. Furthermore, chemical inhibition of efflux pumps potentiates glutaraldehyde activity, suggesting that efflux activity contributes to glutaraldehyde resistance. Additionally, induction of known modulators of biofilm formation, including phosphonate degradation, lipid biosynthesis, and polyamine biosynthesis, may contribute to biofilm resistance and resilience. Fundamental understanding of the genetic mechanism of biocide resistance is critical for the optimization of biocide use and development of novel disinfection strategies. Our results reveal genetic components involved in glutaraldehyde resistance and a potential strategy for improved control of biofilms.
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147
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Supramolecular cationic assemblies against multidrug-resistant microorganisms: activity and mechanism of action. Int J Mol Sci 2015; 16:6337-52. [PMID: 25809608 PMCID: PMC4394535 DOI: 10.3390/ijms16036337] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 03/12/2015] [Accepted: 03/16/2015] [Indexed: 11/30/2022] Open
Abstract
The growing challenge of antimicrobial resistance to antibiotics requires novel synthetic drugs or new formulations for old drugs. Here, cationic nanostructured particles (NPs) self-assembled from cationic bilayer fragments and polyelectrolytes are tested against four multidrug-resistant (MDR) strains of clinical importance. The non-hemolytic poly(diallyldimethylammonium) chloride (PDDA) polymer as the outer NP layer shows a remarkable activity against these organisms. The mechanism of cell death involves bacterial membrane lysis as determined from the leakage of inner phosphorylated compounds and possibly disassembly of the NP with the appearance of multilayered fibers made of the NP components and the biopolymers withdrawn from the cell wall. The NPs display broad-spectrum activity against MDR microorganisms, including Gram-negative and Gram-positive bacteria and yeast.
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148
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Carey DE, McNamara PJ. The impact of triclosan on the spread of antibiotic resistance in the environment. Front Microbiol 2015; 5:780. [PMID: 25642217 PMCID: PMC4295542 DOI: 10.3389/fmicb.2014.00780] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2014] [Accepted: 12/19/2014] [Indexed: 12/22/2022] Open
Abstract
Triclosan (TCS) is a commonly used antimicrobial agent that enters wastewater treatment plants (WWTPs) and the environment. An estimated 1.1 × 10(5) to 4.2 × 10(5) kg of TCS are discharged from these WWTPs per year in the United States. The abundance of TCS along with its antimicrobial properties have given rise to concern regarding its impact on antibiotic resistance in the environment. The objective of this review is to assess the state of knowledge regarding the impact of TCS on multidrug resistance in environmental settings, including engineered environments such as anaerobic digesters. Pure culture studies are reviewed in this paper to gain insight into the substantially smaller body of research surrounding the impacts of TCS on environmental microbial communities. Pure culture studies, mainly on pathogenic strains of bacteria, demonstrate that TCS is often associated with multidrug resistance. Research is lacking to quantify the current impacts of TCS discharge to the environment, but it is known that resistance to TCS and multidrug resistance can increase in environmental microbial communities exposed to TCS. Research plans are proposed to quantitatively define the conditions under which TCS selects for multidrug resistance in the environment.
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Affiliation(s)
| | - Patrick J. McNamara
- Department of Civil, Construction and Environmental Engineering, Marquette University, Milwaukee, WI, USA
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149
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Ogasawara H, Ohe S, Ishihama A. Role of transcription factor NimR (YeaM) in sensitivity control of Escherichia coli to 2-nitroimidazole. FEMS Microbiol Lett 2015; 362:1-8. [DOI: 10.1093/femsle/fnu013] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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150
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Yadav R, Balasubramanian K. Metallization of electrospun PAN nanofibers via electroless gold plating. RSC Adv 2015. [DOI: 10.1039/c5ra03531g] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
An electroless gold plating process was investigated for the metallization of an electropun PAN fibre by utilizing a non-cyanide based gold complex i.e. gold thiosulfate.
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Affiliation(s)
- Ramdayal Yadav
- Defence Institute of Advanced Technology
- Ministry of Defence
- Pune-411025
- India
| | - K. Balasubramanian
- Defence Institute of Advanced Technology
- Ministry of Defence
- Pune-411025
- India
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