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Boss S, Stephan R, Horlbog JA, Magouras I, Colon VA, Lugsomya K, Stevens MJA, Nüesch-Inderbinen M. Serotypes, Antimicrobial Resistance Profiles, and Virulence Factors of Salmonella Isolates in Chinese Edible Frogs ( Hoplobatrachus rugulosus) Collected from Wet Markets in Hong Kong. Foods 2023; 12:foods12112245. [PMID: 37297489 DOI: 10.3390/foods12112245] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 05/27/2023] [Accepted: 05/30/2023] [Indexed: 06/12/2023] Open
Abstract
Salmonella is an important agent of gastrointestinal disease in humans. While livestock, such as cattle, poultry, and pigs, are well-recognised animal reservoirs of Salmonella, there is a lack of data on Salmonella in edible frogs, even though frog meat is a popular food worldwide. In this study, 103 live edible Chinese frogs (Hoplobatrachus rugulosus) were collected from wet markets throughout Hong Kong. After euthanasia, faeces or cloacal swabs were examined for Salmonella. Overall, Salmonella spp. were isolated from 67 (65%, CI: 0.554-0.736) of the samples. The serotypes included S. Saintpaul (33%), S. Newport (24%), S. Bareilly (7%), S. Braenderup (4%), S. Hvittingfoss (4%), S. Stanley (10%), and S. Wandsworth (16%). Many isolates were phylogenetically related. A high number of genes encoding for resistance to clinically relevant antimicrobials, and a high number of virulence determinants, were identified. Antimicrobial susceptibility testing (AST) identified multidrug resistance (MDR) in 21% of the isolates. Resistance to ampicillin, ciprofloxacin, nalidixic acid, and tetracycline was common. These results demonstrate that a high percentage of live frogs sold for human consumption in wet markets are carriers of multidrug-resistant Salmonella. Public health recommendations for handling edible frogs should be considered, to mitigate the risk of Salmonella transmission to humans.
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Affiliation(s)
- Sara Boss
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland
| | - Roger Stephan
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland
| | - Jule Anna Horlbog
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland
| | - Ioannis Magouras
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong SAR, China
- Centre for Applied One Health Research and Policy Advice, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Violaine Albane Colon
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Kittitat Lugsomya
- Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Marc J A Stevens
- Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, 8057 Zurich, Switzerland
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Narendrakumar L, Gupta SS, Johnson JB, Ramamurthy T, Thomas S. Molecular Adaptations and Antibiotic Resistance inVibrio cholerae: A Communal Challenge. Microb Drug Resist 2019; 25:1012-1022. [DOI: 10.1089/mdr.2018.0354] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Affiliation(s)
- Lekshmi Narendrakumar
- Cholera and Biofilm Research Laboratory, Rajiv Gandhi Centre for Biotechnology, Kerala, India
- Research Scholar, University of Kerala, Kerala, India
| | | | - John B. Johnson
- Viral Disease Biology, Rajiv Gandhi Centre for Biotechnology, Kerala, India
| | | | - Sabu Thomas
- Cholera and Biofilm Research Laboratory, Rajiv Gandhi Centre for Biotechnology, Kerala, India
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Changing paradigm of antibiotic resistance amongst Escherichia coli isolates in Indian pediatric population. PLoS One 2019; 14:e0213850. [PMID: 30995225 PMCID: PMC6469777 DOI: 10.1371/journal.pone.0213850] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 03/02/2019] [Indexed: 12/14/2022] Open
Abstract
Antimicrobial resistance happens when microorganisms mutates in manners that render the drugs like antibacterial, antiviral, antiparasitic and antifungal, ineffective. The normal mutation process is encouraged by the improper use of antibiotics. Mutations leading to quinolone resistance occur in a highly conserved region of the quinolone resistance-determining region (QRDR) of DNA gyrAse and topoisomerase IV gene. We analyzed antibiotic resistant genes and single nucleotide polymorphism (SNP) in gyrA and parC genes in QRDR in 120 E. coli isolates (both diarrheagenic and non-pathogenic) recovered from fresh stool samples collected from children aged less than 5 years from Delhi, India. Antibiotic susceptibility testing was performed according to standard clinical and laboratory standards institute (CLSI) guidelines. Phylogenetic analysis showed the clonal diversity and phylogenetic relationships among the E. coli isolates. The SNP analysis depicted mutations in gyrA and parC genes in QRDR. The sul1 gene, responsible for sulfonamide resistance, was present in almost half (47.5%) of the isolates across the diseased and healthy samples. The presence of antibiotic resistance genes in E. coli isolates from healthy children indicate the development, dissemination and carriage of antibiotic resistance in their gut. Our observations suggest the implementation of active surveillance and stewardship programs to promote appropriate antibiotic use and minimizing further danger.
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Dionisio F, Zilhão R, Gama JA. Interactions between plasmids and other mobile genetic elements affect their transmission and persistence. Plasmid 2019; 102:29-36. [DOI: 10.1016/j.plasmid.2019.01.003] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 01/24/2019] [Accepted: 01/30/2019] [Indexed: 10/27/2022]
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Ganaie HA. Fungal Diseases of Animals: Symptoms and Their Cure by Natural Products. Fungal Biol 2019. [DOI: 10.1007/978-3-030-18586-2_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Li L, Zhao X. Characterization of the resistance class 1 integrons in Staphylococcus aureus isolates from milk of lactating dairy cattle in Northwestern China. BMC Vet Res 2018; 14:59. [PMID: 29482565 PMCID: PMC5827992 DOI: 10.1186/s12917-018-1376-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 02/15/2018] [Indexed: 11/19/2022] Open
Abstract
Background Integrons are mobile DNA elements and they have an important role in acquisition and dissemination of antimicrobial resistance genes. However, there are limited data available on integrons of Staphylococcus aureus (S. aureus) from bovine mastitis, especially from Chinese dairy cows. To address this knowledge gap, bovine mastitis-inducing S. aureus isolates were investigated for the presence of integrons as well as characterization of gene cassettes. Integrons were detected using PCR reactions and then further characterized by a restriction fragment-length polymorphism analysis and amplicon sequencing. Results All 121 S. aureus isolates carried the class 1 integrase gene intI1, with no intI2 and intI3 genes detected. One hundred and three isolates were positive for the presence of 12 resistance genes, either alone or in combination with other gene cassettes. These resistance genes encoded resistance to trimethoprim (dhfrV, dfrA1, dfrA12), aminoglycosides (aadA1, aadA5, aadA4, aadA24, aacA4, aadA2, aadB), chloramphenicol (cmlA6) and quaternary ammonium compound (qacH) and were organized into 11 different gene cassettes arrangements (A-K). The gene cassette arrays dfrA1-aadA1 (D, 44.6%), aadA2 (K, 31.4%), dfrA12-orfX2-aadA2 (G, 27.3%) and aadA1 (A, 25.6%) were most prevalent. Furthermore, 74 isolates contained combinations of 2 to 4 gene cassette arrays. Finally, all of the integron/cassettes-positive isolates were resistant to aminoglycoside antibiotics. Conclusions This is the first study on the integrons and gene cassette arrays in S. aureus isolates from milk of mastitic cows from Northwestern China and provide the evidence for class 1 integron as possible antibiotic resistance determinants on dairy farms.
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Affiliation(s)
- Longping Li
- College of Animal Science and Technology, Northwest A&F University, YangLing, Shaanxi, People's Republic of China.,Life Science Research Center, Yulin University, Yulin, 719000, People's Republic of China.,Shaanxi Provincial Engineering and Technology Research Center of Cashmere Goat, Yulin University, Yulin, 719000, People's Republic of China
| | - Xin Zhao
- College of Animal Science and Technology, Northwest A&F University, YangLing, Shaanxi, People's Republic of China. .,Department of Animal Science, McGill University, 21,111 Lakeshore, Ste. Anne de Bellevue, Quebec, H9X 3V9, Canada.
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Lin M, Wu X, Yan Q, Ma Y, Huang L, Qin Y, Xu X. Incidence of antimicrobial-resistance genes and integrons in antibiotic-resistant bacteria isolated from eels and aquaculture ponds. DISEASES OF AQUATIC ORGANISMS 2016; 120:115-123. [PMID: 27409235 DOI: 10.3354/dao03013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The overuse of antimicrobials in aquaculture has promoted the selection of antimicrobial-resistant bacteria. Here we investigated the abundance of antimicrobial-resistance genes and integrons in 108 strains of antibiotic-resistant bacteria isolated from eels and aquaculture ponds in China. Conventional PCR was implemented to examine common antibiotic-resistance genes, integrons, and their gene cassette arrays. The results showed that the antibiotic-resistance genes blaTEM, tetC, sulI, aadA, floR, and qnrB were detected at high percentages, as were a number of other resistance genes. Class I integrons were present in 79.63% of the strains, and 10 out of 108 isolates carried class II integrons. Class III integrons were not detected. Three strains carried both class I and class II integrons, and 73.26% of the class I integron-positive isolates contained the qacEΔ1/sul1 gene. Fourteen types of integron cassette arrays were found among class I integron-positive isolates. A new array, dfrB4-catB3-blaOXA-10-aadA1, was discovered in this study. The gene cassette array dfrA12-orfF-aadA2 was the most widely distributed. In summary, 23 different gene cassettes encoding resistance to 8 classes of antibiotics were identified in the class I integrons, and the main cassettes contained genes encoding resistance to aminoglycosides (aad) and trimethoprim (dfr). All class II integron-positive strains had only a single gene cassette array, viz. dfrA1-catB2-sat2-aadA1. High levels of antimicrobial-resistance genes and integrons in eels and auqauculture ponds suggest that the overuse of antimicrobials should be strictly controlled and that the levels of bacterial antimicrobial-resistance genes in aquaculture should be monitored.
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Affiliation(s)
- Mao Lin
- Jimei University, Xiamen 361021, Fujian, PR China Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education, Xiamen 361021, Fujian, PR China
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8
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Shah SQA, Cabello FC, L'abée-Lund TM, Tomova A, Godfrey HP, Buschmann AH, Sørum H. Antimicrobial resistance and antimicrobial resistance genes in marine bacteria from salmon aquaculture and non-aquaculture sites. Environ Microbiol 2014; 16:1310-20. [PMID: 24612265 DOI: 10.1111/1462-2920.12421] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 01/29/2014] [Accepted: 01/31/2014] [Indexed: 11/29/2022]
Abstract
Antimicrobial resistance (AR) detected by disc diffusion and antimicrobial resistance genes detected by DNA hybridization and polymerase chain reaction with amplicon sequencing were studied in 124 marine bacterial isolates from a Chilean salmon aquaculture site and 76 from a site without aquaculture 8 km distant. Resistance to one or more antimicrobials was present in 81% of the isolates regardless of site. Resistance to tetracycline was most commonly encoded by tetA and tetG; to trimethoprim, by dfrA1, dfrA5 and dfrA12; to sulfamethizole, by sul1 and sul2; to amoxicillin, by blaTEM ; and to streptomycin, by strA-strB. Integron integrase intl1 was detected in 14 sul1-positive isolates, associated with aad9 gene cassettes in two from the aquaculture site. intl2 Integrase was only detected in three dfrA1-positive isolates from the aquaculture site and was not associated with gene cassettes in any. Of nine isolates tested for conjugation, two from the aquaculture site transferred AR determinants to Escherichia coli. High levels of AR in marine sediments from aquaculture and non-aquaculture sites suggest that dispersion of the large amounts of antimicrobials used in Chilean salmon aquaculture has created selective pressure in areas of the marine environment far removed from the initial site of use of these agents.
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Affiliation(s)
- Syed Q A Shah
- Norwegian University of Life Sciences, Ullevålsvein 72, Oslo, Norway
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Multiple Pathways of Genome Plasticity Leading to Development of Antibiotic Resistance. Antibiotics (Basel) 2013; 2:288-315. [PMID: 27029305 PMCID: PMC4790341 DOI: 10.3390/antibiotics2020288] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 05/21/2013] [Accepted: 05/23/2013] [Indexed: 02/05/2023] Open
Abstract
The emergence of multi-resistant bacterial strains is a major source of concern and has been correlated with the widespread use of antibiotics. The origins of resistance are intensively studied and many mechanisms involved in resistance have been identified, such as exogenous gene acquisition by horizontal gene transfer (HGT), mutations in the targeted functions, and more recently, antibiotic tolerance through persistence. In this review, we focus on factors leading to integron rearrangements and gene capture facilitating antibiotic resistance acquisition, maintenance and spread. The role of stress responses, such as the SOS response, is discussed.
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Cabello FC, Godfrey HP, Tomova A, Ivanova L, Dölz H, Millanao A, Buschmann AH. Antimicrobial use in aquaculture re-examined: its relevance to antimicrobial resistance and to animal and human health. Environ Microbiol 2013; 15:1917-42. [PMID: 23711078 DOI: 10.1111/1462-2920.12134] [Citation(s) in RCA: 396] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 02/10/2013] [Accepted: 02/14/2013] [Indexed: 12/18/2022]
Abstract
The worldwide growth of aquaculture has been accompanied by a rapid increase in therapeutic and prophylactic usage of antimicrobials including those important in human therapeutics. Approximately 80% of antimicrobials used in aquaculture enter the environment with their activity intact where they select for bacteria whose resistance arises from mutations or more importantly, from mobile genetic elements containing multiple resistance determinants transmissible to other bacteria. Such selection alters biodiversity in aquatic environments and the normal flora of fish and shellfish. The commonality of the mobilome (the total of all mobile genetic elements in a genome) between aquatic and terrestrial bacteria together with the presence of residual antimicrobials, biofilms, and high concentrations of bacteriophages where the aquatic environment may also be contaminated with pathogens of human and animal origin can stimulate exchange of genetic information between aquatic and terrestrial bacteria. Several recently found genetic elements and resistance determinants for quinolones, tetracyclines, and β-lactamases are shared between aquatic bacteria, fish pathogens, and human pathogens, and appear to have originated in aquatic bacteria. Excessive use of antimicrobials in aquaculture can thus potentially negatively impact animal and human health as well as the aquatic environment and should be better assessed and regulated.
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Affiliation(s)
- Felipe C Cabello
- Department of Microbiology and Immunology, New York Medical College, Valhalla, NY, 10595, USA.
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Tennstedt T, Szczepanowski R, Braun S, Pühler A, Schlüter A. Occurrence of integron-associated resistance gene cassettes located on antibiotic resistance plasmids isolated from a wastewater treatment plant. FEMS Microbiol Ecol 2012; 45:239-52. [PMID: 19719593 DOI: 10.1016/s0168-6496(03)00164-8] [Citation(s) in RCA: 165] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The role of a municipal wastewater treatment plant as a reservoir for bacteria carrying antibiotic resistance plasmids was analysed. Altogether, ninety-seven different multiresistance plasmids were isolated and screened by PCR for the presence of class 1 integron-specific sequences. Twelve of these plasmids were identified to carry integrons. In addition, integron-specific sequences were found on plasmid-DNA preparations from bacteria residing in activated sludge and in the final effluents of the wastewater treatment plant. Sequencing and annotation of the integrons identified nineteen different gene cassette arrays, containing twenty-one different resistance gene cassettes. These cassettes carry genes encoding eight different aminoglycoside-modifying enzymes, seven dihydrofolate reductases, three beta-lactamases, two chloramphenicol resistance proteins and two small exporter proteins. Moreover, new gene cassettes and cassettes with unknown function were identified. Eleven gene cassette combinations are described for the first time. Six integron-associated gene cassette arrays are located on self-transmissible, putative broad-host-range plasmids belonging to the IncP group. Hybridisation analyses, using the integron-specific gene cassette arrays as templates and labelled plasmid-DNA preparations from bacteria of the final effluents as hybridisation probes, revealed that bacteria containing integron-specific sequences on plasmids are released into the environment.
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Affiliation(s)
- Thomas Tennstedt
- Fakultät für Biologie, Lehrstuhl für Genetik, Universität Bielefeld, Postfach 100131, D-33501 Bielefeld, Germany
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Igbinosa EO, Obi LC, Tom M, Okoh AI. Detection of potential risk of wastewater effluents for transmission of antibiotic resistance from Vibrio species as a reservoir in a peri-urban community in South Africa. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2011; 21:402-414. [PMID: 21574085 DOI: 10.1080/09603123.2011.572278] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We assessed the antibiogram characteristics of some Vibrio species isolated from wastewater final effluents in a typical peri-urban community of South Africa. Marked resistances were noted against erythromycin (100%), chloramphenicol (100%), nitrofurantoin, cefuroxime and cephalothin (90-95%) in V. parahaemolyticus, V. fluvialis and V. vulnificus, respectively. Fourteen antibiotypes were identified, with multiresistance to 8-10 antibiotics being common. The antibiotypes AMP, PEN, STR, SUL, TMP, COT, CHL, ERY, CIP and PB demonstrated by V. fluvialis were the most prevalent (17.24%). Eight putative antibiotic resistance genes were identified with floR being the mostly (100%) detected in all the three species while tet(A) was the least with 65% prevalence in V. vulnificus, 7.14% in V. parahaemolyticus and none in V. fluvialis. These results demonstrate that the treated effluent system are reservoirs for various antibiotic resistance genes which could be disseminated to inhabitants downstream the plant and pose health risk to the communities who are dependent upon the watershed for domestic and recreational purposes.
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Affiliation(s)
- Etinosa O Igbinosa
- Applied and Environmental Microbiology Research Group (AEMREG), Department of Biochemistry and Microbiology, University of Fort Hare, Alice, South Africa
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Baharoglu Z, Bikard D, Mazel D. Conjugative DNA transfer induces the bacterial SOS response and promotes antibiotic resistance development through integron activation. PLoS Genet 2010; 6:e1001165. [PMID: 20975940 PMCID: PMC2958807 DOI: 10.1371/journal.pgen.1001165] [Citation(s) in RCA: 189] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Accepted: 09/17/2010] [Indexed: 11/21/2022] Open
Abstract
Conjugation is one mechanism for intra- and inter-species horizontal gene transfer among bacteria. Conjugative elements have been instrumental in many bacterial species to face the threat of antibiotics, by allowing them to evolve and adapt to these hostile conditions. Conjugative plasmids are transferred to plasmidless recipient cells as single-stranded DNA. We used lacZ and gfp fusions to address whether conjugation induces the SOS response and the integron integrase. The SOS response controls a series of genes responsible for DNA damage repair, which can lead to recombination and mutagenesis. In this manuscript, we show that conjugative transfer of ssDNA induces the bacterial SOS stress response, unless an anti-SOS factor is present to alleviate this response. We also show that integron integrases are up-regulated during this process, resulting in increased cassette rearrangements. Moreover, the data we obtained using broad and narrow host range plasmids strongly suggests that plasmid transfer, even abortive, can trigger chromosomal gene rearrangements and transcriptional switches in the recipient cell. Our results highlight the importance of environments concentrating disparate bacterial communities as reactors for extensive genetic adaptation of bacteria. Bacteria exchange DNA in their natural environments. The process called conjugation consists of DNA transfer by cell contact from one bacterium to another. Conjugative circular plasmids have been identified as shuttles and reservoirs for adaptive genes. It is now established that such lateral gene transfer plays an essential role, especially for the antibiotic resistance development and dissemination among bacteria. Moreover, integrons, platforms of mobile gene cassettes, have been instrumental in this phenomenon, through their successful association with conjugative resistance plasmids. We demonstrate in this study that the conjugative transfer of plasmids triggers a bacterial stress response—the SOS response—in recipient cells and can impact the cassette content of integrons. The SOS response is already known to induce various genome modifications. Human and animal pathogens cohabit with environmental bacteria, in niches which will favor DNA exchange. SOS induction during conjugation is thus most probably able to impact a wide range of genomes. Bacterial SOS response could then be a suitable target for co-treatment of infections in order to prevent exchange of antibiotic resistance/adaptation genes.
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Affiliation(s)
- Zeynep Baharoglu
- Institut Pasteur, Unité Plasticité du Génome Bactérien, Département Génomes et Génétique, Paris, France
- CNRS, URA2171, Paris, France
| | - David Bikard
- Institut Pasteur, Unité Plasticité du Génome Bactérien, Département Génomes et Génétique, Paris, France
- CNRS, URA2171, Paris, France
| | - Didier Mazel
- Institut Pasteur, Unité Plasticité du Génome Bactérien, Département Génomes et Génétique, Paris, France
- CNRS, URA2171, Paris, France
- * E-mail:
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Sandalli C, Buruk CK, Sancaktar M, Ozgumus OB. Prevalence of integrons and a newdfrA17variant in Gram-negative bacilli which cause community-acquired infections. Microbiol Immunol 2010; 54:164-9. [DOI: 10.1111/j.1348-0421.2010.00197.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Kiiru JN, Saidi SM, Goddeeris BM, Wamae NC, Butaye P, Kariuki SM. Molecular characterisation of Vibrio cholerae O1 strains carrying an SXT/R391-like element from cholera outbreaks in Kenya: 1994-2007. BMC Microbiol 2009; 9:275. [PMID: 20040104 PMCID: PMC2806261 DOI: 10.1186/1471-2180-9-275] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Accepted: 12/29/2009] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Over the last decade, cholera outbreaks in parts of Kenya have become common. Although a number of recent studies describe the epidemiology of cholera in Kenya, there is paucity of information concerning the diversity and occurrence of mobile genetic elements in Vibrio cholerae strains implicated in these outbreaks. A total of 65 Vibrio cholerae O1 El Tor serotype Inaba isolated between 1994 and 2007 from various outbreaks in Kenya were investigated for mobile genetic elements including integrons, transposons, the integrating conjugative elements (ICEs), conjugative plasmids and for their genotypic relatedness. RESULTS All the strains were haemolytic on 5% sheep blood and positive for the Vibrio cholerae El Tor-specific haemolysin toxin gene (hylA) by PCR. They all contained strB, sulII, floR and the dfrA1 genes encoding resistance to streptomycin, sulfamethoxazole, chloramphenicol and trimethoprim respectively. These genes, together with an ICE belonging to the SXT/R391 family were transferable to the rifampicin-resistant E. coli C600 en bloc. All the strains were negative for integron class 1, 2 and 3 and for transposase gene of transposon Tn7 but were positive for integron class 4 and the trpM gene of transposon Tn21. No plasmids were isolated from any of the 65 strains. All the strains were also positive for all V. cholera El Tor pathogenic genes except the NAG- specific heat-stable toxin (st) gene. None of the strains were positive for virulence genes associated with the V. cholerae classical biotype. All the strains were positive for El Tor-specific CTXphi bacteriophage rstrR repressor gene (CTXETPhi) but negative for the Classical, Calcutta, and the Environmental repressor types. Pulse Field Gel Electrophoresis (PFGE) showed that regardless of the year of isolation, all the strains bearing the SXT element were clonally related. CONCLUSIONS This study demonstrates that the V. cholerae O1 strains carrying an SXT/R391-like element implicated in recent cholera outbreaks in Kenya has not changed significantly between 1994 and 2007 and are clonally related.
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Affiliation(s)
- John N Kiiru
- Centre for Microbiology Research, Kenya Medical Research Institute, PO Box 43640, Nairobi, Kenya.
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Sandalli C, Buruk CK, Sancaktar M, Ozgumus OB. Prevalence of integrons and a new dfrA17 variant in Gram-negative bacilli which cause community-acquired infections. Microbiol Immunol 2009. [DOI: 10.1111/j.1348-0421.2009.00197.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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17
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Identification and characterization of class 1 integrons among Pseudomonas aeruginosa isolates from patients in Zhenjiang, China. Int J Infect Dis 2009; 13:717-21. [DOI: 10.1016/j.ijid.2008.11.014] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2008] [Revised: 09/22/2008] [Accepted: 11/26/2008] [Indexed: 11/23/2022] Open
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Abstract
Large amounts of antibiotics used for human therapy, as well as for farm animals and even for fish in aquaculture, resulted in the selection of pathogenic bacteria resistant to multiple drugs. Multidrug resistance in bacteria may be generated by one of two mechanisms. First, these bacteria may accumulate multiple genes, each coding for resistance to a single drug, within a single cell. This accumulation occurs typically on resistance (R) plasmids. Second, multidrug resistance may also occur by the increased expression of genes that code for multidrug efflux pumps, extruding a wide range of drugs. This review discusses our current knowledge on the molecular mechanisms involved in both types of resistance.
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Affiliation(s)
- Hiroshi Nikaido
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202, USA.
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Abstract
Large population sizes, rapid growth and 3.8 billion years of evolution firmly establish microorganisms as a major source of the planet's biological and genetic diversity. However, up to 99% of the microorganisms in a given environment cannot be cultured. Culture-independent methods that directly access the genetic potential of an environmental sample can unveil new proteins with diverse functions, but the sequencing of random DNA can generate enormous amounts of extraneous data. Integrons are recombination systems that accumulate open reading frames (gene cassettes), many of which code for functional proteins with enormous adaptive potential. Some integrons harbor hundreds of gene cassettes and evidence suggests that the gene cassette pool may be limitless in size. Accessing this genetic pool has been hampered since sequence-based techniques, such as hybridization or PCR, often recover only partial genes or a small subset of those present in the sample. Here, a three-plasmid genetic strategy for the sequence-independent recovery of gene cassettes from genomic libraries is described and its use by retrieving functional gene cassettes from the chromosomal integron of Vibrio vulnificus ATCC 27562 is demonstrated. By manipulating the natural activity of integrons, we can gain access to the caches of functional genes amassed by these structures.
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Affiliation(s)
- Dean A Rowe-Magnus
- Division of Clinical Integrative Biology, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, S1-26A, Toronto, Ontario M4N 3N5, Canada.
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Prevalence of antibiotic resistance in drinking water treatment and distribution systems. Appl Environ Microbiol 2009; 75:5714-8. [PMID: 19581476 DOI: 10.1128/aem.00382-09] [Citation(s) in RCA: 289] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The occurrence and spread of antibiotic-resistant bacteria (ARB) are pressing public health problems worldwide, and aquatic ecosystems are a recognized reservoir for ARB. We used culture-dependent methods and quantitative molecular techniques to detect and quantify ARB and antibiotic resistance genes (ARGs) in source waters, drinking water treatment plants, and tap water from several cities in Michigan and Ohio. We found ARGs and heterotrophic ARB in all finished water and tap water tested, although the amounts were small. The quantities of most ARGs were greater in tap water than in finished water and source water. In general, the levels of bacteria were higher in source water than in tap water, and the levels of ARB were higher in tap water than in finished water, indicating that there was regrowth of bacteria in drinking water distribution systems. Elevated resistance to some antibiotics was observed during water treatment and in tap water. Water treatment might increase the antibiotic resistance of surviving bacteria, and water distribution systems may serve as an important reservoir for the spread of antibiotic resistance to opportunistic pathogens.
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Rajpara N, Patel A, Tiwari N, Bahuguna J, Antony A, Choudhury I, Ghosh A, Jain R, Ghosh A, Bhardwaj AK. Mechanism of drug resistance in a clinical isolate of Vibrio fluvialis: involvement of multiple plasmids and integrons. Int J Antimicrob Agents 2009; 34:220-5. [PMID: 19427174 DOI: 10.1016/j.ijantimicag.2009.03.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Revised: 03/26/2009] [Accepted: 03/26/2009] [Indexed: 11/18/2022]
Abstract
The role of mobile genetic elements in imparting multiple drug resistance to a clinical isolate of Vibrio fluvialis (BD146) was investigated. This isolate showed complete or intermediate resistance to all of the 14 antibiotics tested. Polymerase chain reaction (PCR) revealed the presence of a class 1 integron and the absence of the SXT element in this isolate. The strain harboured a 7.5 kb plasmid and a very low copy number plasmid of unknown molecular size. Transformation of Escherichia coli with plasmid(s) from BD146 generated two kinds of transformants, one that harboured both of these plasmids and the other that harboured only the low copy number plasmid. PCR and antibiogram analysis indicated the association of the class 1 integron with the low copy number plasmid, which also conferred all the transferable resistance traits except trimethoprim to the parent strain. A BLAST search with the sequence of the 7.5kb plasmid showed that it was 99% identical to plasmid pVN84 from Vibrio cholerae O1 in Vietnam, indicating that these two plasmids are probably one and the same. To the best of our knowledge, this is the first report of horizontal transfer of a plasmid between V. fluvialis and V. cholerae.
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Affiliation(s)
- Neha Rajpara
- Department of Human Health and Diseases, School of Biological Sciences and Biotechnology, Indian Institute of Advanced Research, Koba Institutional Area, Gandhinagar 382 007, Gujarat, India
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22
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Szczepanowski R, Linke B, Krahn I, Gartemann KH, Gützkow T, Eichler W, Pühler A, Schlüter A. Detection of 140 clinically relevant antibiotic-resistance genes in the plasmid metagenome of wastewater treatment plant bacteria showing reduced susceptibility to selected antibiotics. MICROBIOLOGY-SGM 2009; 155:2306-2319. [PMID: 19389756 DOI: 10.1099/mic.0.028233-0] [Citation(s) in RCA: 300] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
To detect plasmid-borne antibiotic-resistance genes in wastewater treatment plant (WWTP) bacteria, 192 resistance-gene-specific PCR primer pairs were designed and synthesized. Subsequent PCR analyses on total plasmid DNA preparations obtained from bacteria of activated sludge or the WWTP's final effluents led to the identification of, respectively, 140 and 123 different resistance-gene-specific amplicons. The genes detected included aminoglycoside, beta-lactam, chloramphenicol, fluoroquinolone, macrolide, rifampicin, tetracycline, trimethoprim and sulfonamide resistance genes as well as multidrug efflux and small multidrug resistance genes. Some of these genes were only recently described from clinical isolates, demonstrating genetic exchange between clinical and WWTP bacteria. Sequencing of selected resistance-gene-specific amplicons confirmed their identity or revealed that the amplicon nucleotide sequence is very similar to a gene closely related to the reference gene used for primer design. These results demonstrate that WWTP bacteria are a reservoir for various resistance genes. Moreover, detection of about 64 % of the 192 reference resistance genes in bacteria obtained from the WWTP's final effluents indicates that these resistance determinants might be further disseminated in habitats downstream of the sewage plant.
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Affiliation(s)
- Rafael Szczepanowski
- Institute for Genome Research and Systems Biology, Center for Biotechnology, Universität Bielefeld, Postfach 100131, D-33501 Bielefeld, Germany
| | - Burkhard Linke
- Bioinformatics Resource Facility, Center for Biotechnology, Universität Bielefeld, Postfach 100131, D-33501 Bielefeld, Germany
| | - Irene Krahn
- Institute for Genome Research and Systems Biology, Center for Biotechnology, Universität Bielefeld, Postfach 100131, D-33501 Bielefeld, Germany
| | - Karl-Heinz Gartemann
- Lehrstuhl für Gentechnologie und Mikrobiologie, Fakultät für Biologie, Universität Bielefeld, Universitätsstraße 25, D-33615 Bielefeld, Germany
| | - Tim Gützkow
- Institute for Genome Research and Systems Biology, Center for Biotechnology, Universität Bielefeld, Postfach 100131, D-33501 Bielefeld, Germany
| | - Wolfgang Eichler
- Landesamt für Natur, Umwelt und Verbraucherschutz NRW, FB76.2, Auf dem Draap 25, 40221 Düsseldorf, Germany
| | - Alfred Pühler
- Institute for Genome Research and Systems Biology, Center for Biotechnology, Universität Bielefeld, Postfach 100131, D-33501 Bielefeld, Germany
| | - Andreas Schlüter
- Institute for Genome Research and Systems Biology, Center for Biotechnology, Universität Bielefeld, Postfach 100131, D-33501 Bielefeld, Germany
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Labbate M, Case RJ, Stokes HW. The integron/gene cassette system: an active player in bacterial adaptation. Methods Mol Biol 2009; 532:103-25. [PMID: 19271181 DOI: 10.1007/978-1-60327-853-9_6] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
The integron includes a site-specific recombination system capable of integrating and expressing genes contained in structures called mobile gene cassettes. Integrons were originally identified on mobile elements from pathogenic bacteria and were found to be a major reservoir of antibiotic-resistance genes. Integrons are now known to be ancient structures that are phylogenetically diverse and, to date, have been found in approximately 9% of sequenced bacterial genomes. Overall, gene diversity in cassettes is extraordinarily high, suggesting that the integron/gene cassette system has a broad role in adaptation rather than being confined to simply conferring resistance to antibiotics. In this chapter, we provide a review of the integron/gene cassette system highlighting characteristics associated with this system, diversity of elements contained within it, and their importance in driving bacterial evolution and consequently adaptation. Ideas on the evolution of gene cassettes and gene cassette arrays are discussed.
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Affiliation(s)
- Maurizio Labbate
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW, Australia
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Toomey N, Monaghan A, Fanning S, Bolton DJ. Assessment of horizontal gene transfer in Lactic acid bacteria--a comparison of mating techniques with a view to optimising conjugation conditions. J Microbiol Methods 2008; 77:23-8. [PMID: 19135099 DOI: 10.1016/j.mimet.2008.12.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Revised: 12/01/2008] [Accepted: 12/05/2008] [Indexed: 10/21/2022]
Abstract
Plate, filter and broth mating techniques were assessed over a range of pHs using three Lactococcus lactis donor strains (one with an erythromycin resistance marker and two with tetracycline resistance markers, all located on transferable genetic elements) and one L. lactis recipient strain. Transconjugants were confirmed using antibiotic selection, E-tests to determine MICs, PCR assays to detect the corresponding marker genes, DNA fingerprinting by pulsed-field gel electrophoresis (PFGE), and Southern blotting. Horizontal gene transfer (HGT) rates varied (ranging from 1.6 x 10(-1) to 2.3 x 10(-8)). The general trend observed was plate > filter > broth, independent of pH. Our data suggests that standardisation of methodologies to be used to assess HGT, is warranted and would provide a meaningful assessment of the ability of commensal and other bacteria in different environments to transfer relevant markers.
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Affiliation(s)
- Niamh Toomey
- Department of Food Safety, Ashtown Food Research Centre, Teagasc, Ashtown, Dublin 15, Ireland
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25
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Genetic elements responsible for erythromycin resistance in streptococci. Antimicrob Agents Chemother 2008; 53:343-53. [PMID: 19001115 DOI: 10.1128/aac.00781-08] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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26
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Extensively drug-resistant Stenotrophomonas maltophilia in a tertiary care hospital in Taiwan: microbiologic characteristics, clinical features, and outcomes. Diagn Microbiol Infect Dis 2008; 60:205-10. [DOI: 10.1016/j.diagmicrobio.2007.09.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Revised: 08/22/2007] [Accepted: 09/10/2007] [Indexed: 01/08/2023]
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Mukherjee S, Chakraborty R. Conjugation potential and class 1 integron carriage of resident plasmids in river water copiotrophs. Acta Microbiol Immunol Hung 2007; 54:379-97. [PMID: 18088011 DOI: 10.1556/amicr.54.2007.4.5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Plasmid content was investigated in hundred copiotrophic Gram-negative river water isolates that exhibited resistance to four or more antibiotics. A total of seventy-seven isolates were found to carry plasmids of varying sizes. These isolates were primarily grouped as Pseudomonads and members of Enterobacteriaceae on the basis of physiological and biochemical tests. Fifty-six isolates that were rifampicin-sensitive and belonged to Enterobacteriaceae family were chosen as donors for the conjugal transfer assay. Eighteen of the isolates successfully transferred conjugable plasmids to the E. coli DH5alpha recipient. Countable multiple antibiotic resistant transconjugants arose readily and conjugal transfer frequency was in the range of 3.75 x 10(-6) to 1.0 x 10(-1). The most common carriage of resistances conferred by transmissible R plasmids was against ampicillin, cefotaxim and cephalexin. The residence of class 1 integrons on conjugative R plasmids was confirmed in only six transconjugants. Gene cassettes borne on the integrons were identified to be dihydrofolate reductases (dhfrs). The major concern of this study was about the copiotrophs containing self-transmissible R plasmids which may be potential reservoirs of antibiotic-resistance genes and instrumental in dissemination of the same in the environment.
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Affiliation(s)
- Shriparna Mukherjee
- 1 University of North Bengal Department of Biotechnology, Microbial Biotechnology Laboratory Raja Rammohunpur Siliguri 734013 West Bengal India
| | - Ranadhir Chakraborty
- 1 University of North Bengal Department of Biotechnology, Microbial Biotechnology Laboratory Raja Rammohunpur Siliguri 734013 West Bengal India
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28
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Szekeres S, Dauti M, Wilde C, Mazel D, Rowe-Magnus DA. Chromosomal toxin-antitoxin loci can diminish large-scale genome reductions in the absence of selection. Mol Microbiol 2007; 63:1588-605. [PMID: 17367382 DOI: 10.1111/j.1365-2958.2007.05613.x] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Superintegrons (SIs) are chromosomal genetic elements containing assemblies of genes, each flanked by a recombination sequence (attC site) targeted by the integron integrase. SIs may contain hundreds of attC sites and intrinsic instability is anticipated; yet SIs are remarkably stable. This implies that either selective pressure maintains the genes or mechanisms exist which favour their persistence in the absence of selection. Toxin/antitoxin (TA) systems encode a stable toxin and a specific, unstable antitoxin. Once activated, the continued synthesis of the unstable antitoxin is necessary for cell survival. A bioinformatic search of accessible microbial genomes for SIs and TA systems revealed that large SIs harboured TA gene cassettes while smaller SIs did not. We demonstrated the function of TA loci in different genomic contexts where large-scale deletions can occur; in SIs and in a 165 kb dispensable region of the Escherichia coli genome. When devoid of TA loci, large-scale genome loss was evident in both environments. The inclusion of two TA loci, relBE1 and parDE1, which we identified in the Vibrio vulnificus SI rendered these environments refractory to gene loss. Thus, chromosomal TA loci can stabilize massive SI arrays and limit the extensive gene loss that is a hallmark of reductive evolution.
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Affiliation(s)
- Silvia Szekeres
- Division of Clinical Integrative Biology, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, S1-26A, Toronto, Ontario, M4N 3N5, Canada
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Gu B, Tong M, Zhao W, Liu G, Ning M, Pan S, Zhao W. Prevalence and characterization of class I integrons among Pseudomonas aeruginosa and Acinetobacter baumannii isolates from patients in Nanjing, China. J Clin Microbiol 2006; 45:241-3. [PMID: 17122024 PMCID: PMC1828976 DOI: 10.1128/jcm.01318-06] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Class I integrons were detected in 40.8% (40/98) of Pseudomonas aeruginosa strains and 52.8% (56/106) of Acinetobacter baumannii strains in the Nanjing area of China, including several cassette arrays not previously reported.
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Affiliation(s)
- Bing Gu
- Department of Clinical Laboratories, First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
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30
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Cowan D, Meyer Q, Stafford W, Muyanga S, Cameron R, Wittwer P. Metagenomic gene discovery: past, present and future. Trends Biotechnol 2005; 23:321-9. [PMID: 15922085 DOI: 10.1016/j.tibtech.2005.04.001] [Citation(s) in RCA: 148] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2004] [Revised: 02/22/2005] [Accepted: 04/04/2005] [Indexed: 11/29/2022]
Abstract
It is now widely accepted that the application of standard microbiological methods for the recovery of microorganisms from the environment has had limited success in providing access to the true extent of microbial biodiversity. It follows that much of the extant microbial genetic diversity (collectively termed the metagenome) remains unexploited, an issue of considerable relevance to a wider understanding of microbial communities and of considerable importance to the biotechnology industry. The recent development of technologies designed to access this wealth of genetic information through environmental nucleic acid extraction has provided a means of avoiding the limitations of culture-dependent genetic exploitation.
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Affiliation(s)
- Don Cowan
- Advanced Research Centre for Applied Microbiology, Department of Biotechnology, University of the Western Cape, Bellville 7535, Cape Town, South Africa.
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31
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Kim SH, Wei CI, An H. Molecular characterization of multidrug-resistant Proteus mirabilis isolates from retail meat products. J Food Prot 2005; 68:1408-13. [PMID: 16013378 DOI: 10.4315/0362-028x-68.7.1408] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Sixty-four multidrug-resistant isolates of Proteus mirabilis were collected from retail meat products in Oklahoma. The isolates showed four different patterns of antibiotic resistance based on their resistant phenotype and genotypes. Most of these isolates were resistant to ampicillin, tetracycline, gentamycin, and kanamycin. Class 1 integrons were detected as a common carrier of the antibiotic-resistant genes, such as aadA1, aadB, and aadA2. A few isolates (9%) contained class 2 integrons with three gene cassettes included: dhfr1, sat1, and aadA1. These isolates were even resistant to nalidixic acid due to mutations in gyrA and parC. All ampicillin-resistant isolates contained blaTEM-1. Plasmids that contained class 1 or 2 integrons and blaTEM-1 were able to be transferred from P. mirabilis isolates into Escherichia coli by conjugation, indicating that conjugal transfer could contribute to the dissemination of antibiotic resistance genes between the Enterobacteriaceae species.
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Affiliation(s)
- Shin-Hee Kim
- Department of Nutritional Sciences, College of Human Environmental Sciences, Oklahoma State University, Stillwater, Oklahoma 74078, USA.
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Nijssen S, Florijn A, Top J, Willems R, Fluit A, Bonten M. Unnoticed spread of integron-carrying Enterobacteriaceae in intensive care units. Clin Infect Dis 2005; 41:1-9. [PMID: 15937755 DOI: 10.1086/430711] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2005] [Accepted: 02/19/2005] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND Integrons are strongly associated with multidrug resistance in Enterobacteriaceae. Little is known about the natural history of integron-associated resistance in hospitals during nonoutbreak periods. The prevalence of integrons and the incidence of cross-transmission and horizontal gene transfer in Enterobacteriaceae with reduced susceptibility to cephalosporins (ERSC) were determined for 2 intensive care units (ICUs). METHODS Microbiological surveillance using rectal swab samples obtained 2 times per week and genotyping using amplified fragment-length polymorphism (AFLP) were used to determine colonization with and genetic relatedness of ERSC. IntI1 integrase polymerase chain reaction (PCR), conserved-segment PCR, restriction fragment-length polymorphism, and DNA sequencing were used to determine the prevalence and contents of integrons. RESULTS Of 457 patients, 121 patients were colonized with ERSC, and 174 isolates underwent AFLP and PCR. In 34 isolates obtained from 31 patients, 11 different integrons were identified; these integrons encoded resistance to streptomycin/spectinomycin, gentamicin/tobramycin/kanamycin, chloramphenicol, and trimethoprim. Integrons could be divided into 7 clusters of > or =2 isolates each. Compared with isolates that were negative for integrons, isolates that were positive for integrons were associated with resistance to piperacillin, cephalosporins, aminoglycosides, and quinolones. Acquisition rates of integron-carrying ERSC were 10 cases per 1000 patient-days in the first ICU and 8 cases per 1000 patient-days in the second ICU, with most cases (26 of 34) being acquired during the ICU stay. Nineteen episodes resulted from cross-transmission. In addition, 2 cases of interspecies transfer and 1 case of intraspecies transfer of integrons were recorded. Younger age was independently associated with acquisition of integron-carrying ERSC (hazard ratio, 0.953; 95% confidence interval, 0.926-0.987). CONCLUSION Surveillance, genotyping, and integron analysis identified previously unnoticed outbreaks of integron-carrying ERSC. Cross-transmission appeared to be the dominant route of transmission. Therefore, barrier precautions are necessary to prevent further spread.
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Affiliation(s)
- S Nijssen
- Division of Acute Medicine and Infectious Diseases, University Medical Center Utrecht, The Netherlands
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Szczepanowski R, Krahn I, Linke B, Goesmann A, Pühler A, Schlüter A. Antibiotic multiresistance plasmid pRSB101 isolated from a wastewater treatment plant is related to plasmids residing in phytopathogenic bacteria and carries eight different resistance determinants including a multidrug transport system. MICROBIOLOGY-SGM 2005; 150:3613-3630. [PMID: 15528650 DOI: 10.1099/mic.0.27317-0] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Ten different antibiotic resistance plasmids conferring high-level erythromycin resistance were isolated from an activated sludge bacterial community of a wastewater treatment plant by applying a transformation-based approach. One of these plasmids, designated pRSB101, mediates resistance to tetracycline, erythromycin, roxythromycin, sulfonamides, cephalosporins, spectinomycin, streptomycin, trimethoprim, nalidixic acid and low concentrations of norfloxacin. Plasmid pRSB101 was completely sequenced and annotated. Its size is 47 829 bp. Conserved synteny exists between the pRSB101 replication/partition (rep/par) module and the pXAC33-replicon from the phytopathogen Xanthomonas axonopodis pv. citri. The second pRSB101 backbone module encodes a three-Mob-protein type mobilization (mob) system with homology to that of IncQ-like plasmids. Plasmid pRSB101 is mobilizable with the help of the IncP-1alpha plasmid RP4 providing transfer functions in trans. A 20 kb resistance region on pRSB101 is located within an integron-containing Tn402-like transposon. The variable region of the class 1 integron carries the genes dhfr1 for a dihydrofolate reductase, aadA2 for a spectinomycin/streptomycin adenylyltransferase and bla(TLA-2) for a so far unknown Ambler class A extended spectrum beta-lactamase. The integron-specific 3'-segment (qacEDelta1-sul1-orf5Delta) is connected to a macrolide resistance operon consisting of the genes mph(A) (macrolide 2'-phosphotransferase I), mrx (hydrophobic protein of unknown function) and mphR(A) (regulatory protein). Finally, a putative mobile element with the tetracycline resistance genes tetA (tetracycline efflux pump) and tetR was identified upstream of the Tn402-specific transposase gene tniA. The second 'genetic load' region on pRSB101 harbours four distinct mobile genetic elements, another integron belonging to a new class and footprints of two more transposable elements. A tripartite multidrug (MDR) transporter consisting of an ATP-binding-cassette (ABC)-type ATPase and permease, and an efflux membrane fusion protein (MFP) of the RND-family is encoded between the replication/partition and the mobilization module. Homologues of the macrolide resistance genes mph(A), mrx and mphR(A) were detected on eight other erythromycin resistance-plasmids isolated from activated sludge bacteria. Plasmid pRSB101-like repA amplicons were also obtained from plasmid-DNA preparations of the final effluents of the wastewater treatment plant indicating that pRSB101-like plasmids are released with the final effluents into the environment.
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Affiliation(s)
- Rafael Szczepanowski
- Fakultät für Biologie, Lehrstuhl für Genetik, Universität Bielefeld, Postfach 100131, D-33501 Bielefeld, Germany
| | - Irene Krahn
- Fakultät für Biologie, Lehrstuhl für Genetik, Universität Bielefeld, Postfach 100131, D-33501 Bielefeld, Germany
| | - Burkhard Linke
- Center for Biotechnology (CeBiTec), Bioinformatics Resource Facility, Universität Bielefeld, Universitätsstrasse 25, D-33615 Bielefeld, Germany
| | - Alexander Goesmann
- Center for Biotechnology (CeBiTec), Bioinformatics Resource Facility, Universität Bielefeld, Universitätsstrasse 25, D-33615 Bielefeld, Germany
| | - Alfred Pühler
- Fakultät für Biologie, Lehrstuhl für Genetik, Universität Bielefeld, Postfach 100131, D-33501 Bielefeld, Germany
| | - Andreas Schlüter
- Fakultät für Biologie, Lehrstuhl für Genetik, Universität Bielefeld, Postfach 100131, D-33501 Bielefeld, Germany
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Abstract
Bacteria of the genus Acinetobacter are ubiquitous in nature. These organisms were invariably susceptible to many antibiotics in the 1970s. Since that time, acinetobacters have emerged as multiresistant opportunistic nosocomial pathogens. The taxonomy of the genus Acinetobacter underwent extensive revision in the mid-1980s, and at least 32 named and unnamed species have now been described. Of these, Acinetobacter baumannii and the closely related unnamed genomic species 3 and 13 sensu Tjernberg and Ursing (13TU) are the most relevant clinically. Multiresistant strains of these species causing bacteraemia, pneumonia, meningitis, urinary tract infections and surgical wound infections have been isolated from hospitalised patients worldwide. This review provides an overview of the antimicrobial susceptibilities of Acinetobacter spp. in Europe, as well as the main mechanisms of antimicrobial resistance, and summarises the remaining treatment options for multiresistant Acinetobacter infections.
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Affiliation(s)
- M Van Looveren
- Department of Medical Microbiology, University Hospital Antwerp, UA, Antwerp, Belgium.
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Szczepanowski R, Krahn I, Pühler A, Schlüter A. Different molecular rearrangements in the integron of the IncP-1 beta resistance plasmid pB10 isolated from a wastewater treatment plant result in elevated beta-lactam resistance levels. Arch Microbiol 2004; 182:429-35. [PMID: 15375643 DOI: 10.1007/s00203-004-0726-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2004] [Revised: 06/24/2004] [Accepted: 08/05/2004] [Indexed: 10/26/2022]
Abstract
The multiresistance IncP-1 beta plasmid pB10 conferring resistance to ampicillin, streptomycin, sulfonamides, tetracycline and mercury ions was previously obtained from activated sludge bacteria by applying the exogenous isolation method with Pseudomonas sp. strain GFP2 as recipient. A pB10 derivative, designated pB10-1, occurred spontaneously and displays an extended NotI restriction fragment. From the pB10 nucleotide sequence, it is known that the corresponding NotI fragment of this plasmid contains a complete class 1 integron with an oxa2 and an orfE-like gene cassette. Sequencing of the integron-specific variable region present on pB10-1 revealed that a second copy of the oxa2 gene cassette has inserted downstream of the orfE-like cassette. Sequences flanking the second oxa2 cassette indicate that this cassette was excised from pB10 and reinserted at a new site in an integrase-catalyzed manner. Duplication of the oxa2 cassette is associated with a higher level of ampicillin resistance. Another pB10 derivative, designated pB10-2, conferring higher resistance to ampicillin, was shown to carry an IS10 insertion upstream of the oxa2 cassette. Since IS10 possesses a promoter-out activity, it can be assumed that the elevated ampicillin resistance level is due to enhanced transcription of the beta-lactamase gene.
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Affiliation(s)
- Rafael Szczepanowski
- Fakultät für Biologie, Lehrstuhl für Genetik, Universität Bielefeld, Postfach 100131, 33501 Bielefeld, Germany
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36
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Del Grosso M, Scotto d'Abusco A, Iannelli F, Pozzi G, Pantosti A. Tn2009, a Tn916-like element containing mef(E) in Streptococcus pneumoniae. Antimicrob Agents Chemother 2004; 48:2037-42. [PMID: 15155196 PMCID: PMC415626 DOI: 10.1128/aac.48.6.2037-2042.2004] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The association between the macrolide efflux gene mef(E) and the tet(M) gene was studied in two clinical strains of Streptococcus pneumoniae that belonged to serotypes 19F and 6A, respectively, and that were resistant to both tetracycline and erythromycin. The mef(E)-carrying element mega (macrolide efflux genetic assembly; 5,511 bp) was found to be inserted into a Tn916-like genetic element present in the chromosomes of the two pneumococcal strains. In both strains, mega was integrated at the same site, an open reading frame identical to orf6 of Tn916. The new composite element, Tn2009, was about 23.5 kb and, with the exception of the tet(M)-coding sequence, appeared to be identical in both strains. By sequencing of the junction fragments of Tn2009 at the site of insertion into the chromosome, it was possible to show that (i) the insertion site was identical in the two clinical strains and (ii) the integration of Tn2009 caused a 9.5 kb-deletion in the pneumococcal chromosome. It was not possible to detect the conjugal transfer of Tn2009 to a recipient pneumococcal strain; however, transfer of the whole element by transformation was shown to occur. It is possible to hypothesize that Tn2009 relies on transformation for its spread among clinical strains of S. pneumoniae.
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Affiliation(s)
- Maria Del Grosso
- Department of Infectious, Parasitic and Immunomediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
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37
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Abstract
The integron content of Gram-negative strains implicated in three distinct episodes of suspected cross-infection among inpatients was investigated and compared with ribotyping. In the first episode, ribotyping identified a strain of Acinetobacter, isolated over a 3-month period, responsible for an outbreak associated with the use of mechanical ventilation in the intensive care unit (ICU). The second episode concerned simultaneous isolations of Pseudomonas aeruginosa and Serratia marcescens from 13 bronchoscopy patients. In these two episodes, results obtained by analysis of integron content and ribotyping were in agreement and correctly identified the epidemiologically related strains. In the third episode, isolates of Enterobacter cloacae were collected from patients in the neonatal ICU over a 3-month period. Although several isolates belonged to the same ribotype, cross-infection could not always be confirmed when the integron content was analysed. Integron detection can be considered a useful tool for studying molecular epidemiology in hospital environments, facilitating the quick detection of possible cross-infection cases, especially in critical wards such as the ICU.
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Affiliation(s)
- P Severino
- Center for Experimental Research, Education and Research Institute, Hospital Albert Einstein, São Paulo, Brazil.
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38
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Chen CY, Wu KM, Chang YC, Chang CH, Tsai HC, Liao TL, Liu YM, Chen HJ, Shen ABT, Li JC, Su TL, Shao CP, Lee CT, Hor LI, Tsai SF. Comparative genome analysis of Vibrio vulnificus, a marine pathogen. Genome Res 2004; 13:2577-87. [PMID: 14656965 PMCID: PMC403799 DOI: 10.1101/gr.1295503] [Citation(s) in RCA: 310] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The halophile Vibrio vulnificus is an etiologic agent of human mortality from seafood-borne infections. We applied whole-genome sequencing and comparative analysis to investigate the evolution of this pathogen. The genome of biotype 1 strain, V. vulnificus YJ016, was sequenced and includes two chromosomes of estimated 3377 kbp and 1857 kbp in size, and a plasmid of 48,508 bp. A super-integron (SI) was identified, and the SI region spans 139 kbp and contains 188 gene cassettes. In contrast to non-SI sequences, the captured gene cassettes are unique for any given Vibrio species and are highly variable among V. vulnificus strains. Multiple rearrangements were found when comparing the 5.3-Mbp V. vulnificus YJ016 genome and the 4.0-Mbp V. cholerae El Tor N16961 genome. The organization of gene clusters of capsular polysaccharide, iron metabolism, and RTX toxin showed distinct genetic features of V. vulnificus and V. cholerae. The content of the V. vulnificus genome contained gene duplications and evidence of horizontal transfer, allowing for genetic diversity and function in the marine environment. The genomic information obtained in this study can be applied to monitoring vibrio infections and identifying virulence genes in V. vulnificus.
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Affiliation(s)
- Chung-Yung Chen
- Division of Molecular and Genomic Medicine, National Health Research Institutes, Taipei 115, Taiwan
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39
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Houang ETS, Chu YW, Lo WS, Chu KY, Cheng AFB. Epidemiology of rifampin ADP-ribosyltransferase (arr-2) and metallo-beta-lactamase (blaIMP-4) gene cassettes in class 1 integrons in Acinetobacter strains isolated from blood cultures in 1997 to 2000. Antimicrob Agents Chemother 2003; 47:1382-90. [PMID: 12654674 PMCID: PMC152494 DOI: 10.1128/aac.47.4.1382-1390.2003] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We characterized two new gene cassettes in an Acinetobacter isolate: one harbored the metallo-beta-lactamase (IMP-4) gene bla(IMP-4), the other harbored the rifampin ADP-ribosyltransferase (ARR-2) gene arr-2, and both arrayed with the aminoglycoside acetyltransferase [AAC(6')-Ib(7)] gene cassette aacA4 in two separate class 1 integrons. The epidemiology of these gene cassettes in isolates from blood cultures obtained from 1997 to 2000 was studied. Isolates bearing either the bla(IMP-4) or the arr-2 gene cassette or both represented 17.5% (10 of 57) of isolates in 1997, 16.1% (10 of 62) in 1998, 2.5% (1 of 40) in 1999, and 0% (0 of 58) in 2000. These two gene cassettes, probably borne on two separate integrons, were found in at least three genomic DNA groups, with evidence of clonal dissemination in the intensive care unit during 1997 to 1998. Seventeen of the 52 Acinetobacter baumannii (genomic DNA group 2) isolates from 1997 to 2000 harbored intI1, but only one was positive for these gene cassettes, whereas 20 of the 21 intI1-positive isolates of all other genomic DNA groups were positive for either or both of them. Reduced susceptibility to imipenem and rifampin was seen only in isolates harboring the bla(IMP-4) and arr-2 cassettes, respectively. The aminoglycoside phosphotransferase [APH(3')-VIa] gene aph(3')-VIa was detected in all 21 isolates for which the MIC of amikacin was >/=8 micro g/ml, with or without aacA4, whereas aacA4 alone was found in isolates for which the MIC of amikacin was 0.5 to 2 micro g/ml. Significant differences between the 17 intI1-positive and 47 intI1-negative isolates belonging to genomic DNA group 3 from 1997 to 1998 in the MICs of amikacin, gentamicin, imipenem, sulfamethoxazole, and ceftazidime were observed (Mann-Whitney test, P < 0.001 to 0.01).
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Affiliation(s)
- Elizabeth T S Houang
- Department of Microbiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, China.
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40
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Abstract
Antimicrobial resistance may become a major problem in veterinary medicine as a consequence of the intensive use and misuse of antimicrobial drugs. Related problems are now arising in human medicine, such as the appearance of multi-resistant food-borne pathogens. Product characteristics, dose, treatment interval and duration of treatment influence the selection pressure for antimicrobial drug resistance. There are theoretical, experimental and clinical indications that the emergence of de novo resistance in a pathogenic population can be prevented by minimizing the time that suboptimal drug levels are present in the infected tissue compartment. Until recently, attention has been focused on target pathogens. However, it should be kept in mind that when antimicrobial drugs are used in an individual, resistance selection mainly affects the normal body flora. In the long term, this is at least equally important as resistance selection in the target pathogens, as the horizontal transfer of resistance genes converts almost all pathogenic bacteria into potential recipients for antimicrobial resistance. Other factors contributing to the epidemiology of antimicrobial resistance are the localization and size of the microbial population, and the age, immunity and contact intensity of the host. In livestock, dynamic herd-related resistance patterns have been observed in different animal species.
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Affiliation(s)
- B Catry
- Department of Reproduction, Obstetrics and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan, Merelbeke, Belgium.
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41
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Roe MT, Pillai SD. Monitoring and identifying antibiotic resistance mechanisms in bacteria. Poult Sci 2003; 82:622-6. [PMID: 12710483 DOI: 10.1093/ps/82.4.622] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Sub-therapeutic administration of antibiotics to animals is under intense scrutiny because they contribute to the dissemination of antibiotic-resistant bacteria into the food chain. Studies suggest that there is a link between the agricultural use of antibiotics and antibiotic-resistant human infections. Antibiotic-resistant organisms from animal and human wastes reenter the human and animal populations through a number of pathways including natural waters, irrigation water, drinking water, and vegetables and foods. Antibiotic usage in the United States for animal production (disease prevention and growth promotion) is estimated to be 18 million pounds annually. As much as 25 to 75% of the antibiotics administered to feedlot animals are excreted unaltered in feces. Because about 180 million dry tons of livestock and poultry waste is generated annually in the United States, it is not surprising that animal-derived antibiotic-resistant organisms are found contaminating groundwater, surface water, and food crops. It is extremely important to clearly understand the molecular mechanisms that could potentially cause lateral or horizontal gene transfer of antibiotic resistance genes among bacteria. Once the mechanisms and magnitude of resistance gene transfer are clearly understood and quantified, strategies can be instituted to reduce the potential for dissemination of these genes.
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Affiliation(s)
- M T Roe
- Food Safety & Environmental Microbiology Program, Poultry Science Department, Texas A&M University, College Station, Texas 77843-2472, USA
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42
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Léon G, Roy PH. Excision and integration of cassettes by an integron integrase of Nitrosomonas europaea. J Bacteriol 2003; 185:2036-41. [PMID: 12618471 PMCID: PMC150120 DOI: 10.1128/jb.185.6.2036-2041.2003] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We found in the environmental strain Nitrosomonas europaea a chromosomal integron-like structure with an integrase gene, intI(Neu). We have tested the capacity of the IntINeu integrase to excise and integrate several resistance gene cassettes. The results allow us to consider IntINeu a new functional integron integrase.
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Affiliation(s)
- Grégory Léon
- Centre de Recherche en Infectiologie, Centre Hospitalier Universitaire de Québec, Québec, Canada
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43
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Rowe-Magnus DA, Guerout AM, Biskri L, Bouige P, Mazel D. Comparative analysis of superintegrons: engineering extensive genetic diversity in the Vibrionaceae. Genome Res 2003; 13:428-42. [PMID: 12618374 PMCID: PMC430272 DOI: 10.1101/gr.617103] [Citation(s) in RCA: 156] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Integrons are natural tools for bacterial evolution and innovation. Their involvement in the capture and dissemination of antibiotic-resistance genes among Gram-negative bacteria is well documented. Recently, massive ancestral versions, the superintegrons (SIs), were discovered in the genomes of diverse proteobacterial species. SI gene cassettes with an identifiable activity encode proteins related to simple adaptive functions, including resistance, virulence, and metabolic activities, and their recruitment was interpreted as providing the host with an adaptive advantage. Here, we present extensive comparative analysis of SIs identified among the Vibrionaceae. Each was at least 100 kb in size, reaffirming the participation of SIs in the genome plasticity and heterogeneity of these species. Phylogenetic and localization data supported the sedentary nature of the functional integron platform and its coevolution with the host genome. Conversely, comparative analysis of the SI cassettes was indicative of both a wide range of origin for the entrapped genes and of an active cassette assembly process in these bacterial species. The signature attC sites of each species displayed conserved structural characteristics indicating that symmetry rather than sequence was important in the recognition of such a varied collection of target recombination sequences by a single site-specific recombinase. Our discovery of various addiction module cassettes within each of the different SIs indicates a possible role for them in the overall stability of large integron cassette arrays.
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Affiliation(s)
- Dean A Rowe-Magnus
- Département de Microbiologie Fondamentale et Médicale, Institut Pasteur, 75724 Paris, France
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44
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Howe CJ, Barbrook AC, Koumandou VL, Nisbet RER, Symington HA, Wightman TF. Evolution of the chloroplast genome. Philos Trans R Soc Lond B Biol Sci 2003; 358:99-106; discussion 106-7. [PMID: 12594920 PMCID: PMC1693101 DOI: 10.1098/rstb.2002.1176] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We discuss the suggestion that differences in the nucleotide composition between plastid and nuclear genomes may provide a selective advantage in the transposition of genes from plastid to nucleus. We show that in the adenine, thymine (AT)-rich genome of Borrelia burgdorferi several genes have an AT-content lower than the average for the genome as a whole. However, genes whose plant homologues have moved from plastid to nucleus are no less AT-rich than genes whose plant homologues have remained in the plastid, indicating that both classes of gene are able to support a high AT-content. We describe the anomalous organization of dinoflagellate plastid genes. These are located on small circles of 2-3 kbp, in contrast to the usual plastid genome organization of a single large circle of 100-200 kbp. Most circles contain a single gene. Some circles contain two genes and some contain none. Dinoflagellate plastids have retained far fewer genes than other plastids. We discuss a similarity between the dinoflagellate minicircles and the bacterial integron system.
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Affiliation(s)
- Christopher J Howe
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1QW, UK.
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45
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Lanz R, Kuhnert P, Boerlin P. Antimicrobial resistance and resistance gene determinants in clinical Escherichia coli from different animal species in Switzerland. Vet Microbiol 2003; 91:73-84. [PMID: 12441233 DOI: 10.1016/s0378-1135(02)00263-8] [Citation(s) in RCA: 226] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Antimicrobial susceptibility testing was performed on a total of 581 clinical Escherichia coli isolates from diarrhea and edema disease in pigs, from acute mastitis in dairy cattle, from urinary tract infections in dogs and cats, and from septicemia in laying hens collected in Switzerland between 1999 and 2001. Among the 16 antimicrobial agents tested, resistance was most frequent for sulfonamides, tetracycline, and streptomycin. Isolates from swine presented significantly more resistance than those from the other animal species. The distribution of the resistance determinants for sulfonamides, tetracycline, and streptomycin was assessed by hybridization and PCR in resistant isolates. Significant differences in the distribution of resistance determinants for tetracycline (tetA, tetB) and sulfonamides (sulII) were observed between the isolates from swine and those from the other species. Resistance to sulfonamides could not be explained by known resistance mechanisms in more than a quarter of the sulfonamide-resistant and sulfonamide-intermediate isolates from swine, dogs and cats. This finding suggests that one or several new resistance mechanisms for sulfonamides may be widespread among E. coli isolates from these animal species. The integrase gene (intI) from class I integrons was detected in a large proportion of resistant isolates in association with the sulI and aadA genes, thus demonstrating the importance of integrons in the epidemiology of resistance in clinical E. coli isolates from animals.
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Affiliation(s)
- Roland Lanz
- Institute for Veterinary Bacteriology, University of Bern, Länggass-Strasse 122, CH-3012 Bern, Switzerland
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46
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Martínez JL, Baquero F. Interactions among strategies associated with bacterial infection: pathogenicity, epidemicity, and antibiotic resistance. Clin Microbiol Rev 2002; 15:647-79. [PMID: 12364374 PMCID: PMC126860 DOI: 10.1128/cmr.15.4.647-679.2002] [Citation(s) in RCA: 299] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Infections have been the major cause of disease throughout the history of human populations. With the introduction of antibiotics, it was thought that this problem should disappear. However, bacteria have been able to evolve to become antibiotic resistant. Nowadays, a proficient pathogen must be virulent, epidemic, and resistant to antibiotics. Analysis of the interplay among these features of bacterial populations is needed to predict the future of infectious diseases. In this regard, we have reviewed the genetic linkage of antibiotic resistance and bacterial virulence in the same genetic determinants as well as the cross talk between antibiotic resistance and virulence regulatory circuits with the aim of understanding the effect of acquisition of resistance on bacterial virulence. We also discuss the possibility that antibiotic resistance and bacterial virulence might prevail as linked phenotypes in the future. The novel situation brought about by the worldwide use of antibiotics is undoubtedly changing bacterial populations. These changes might alter the properties of not only bacterial pathogens, but also the normal host microbiota. The evolutionary consequences of the release of antibiotics into the environment are largely unknown, but most probably restoration of the microbiota from the preantibiotic era is beyond our current abilities.
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Affiliation(s)
- José L Martínez
- Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología. Servicio de Microbiología, Hospital Ramón y Cajal, Madrid, Spain.
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47
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Leverstein-Van Hall MA, Paauw A, Box ATA, Blok HEM, Verhoef J, Fluit AC. Presence of integron-associated resistance in the community is widespread and contributes to multidrug resistance in the hospital. J Clin Microbiol 2002; 40:3038-40. [PMID: 12149373 PMCID: PMC120645 DOI: 10.1128/jcm.40.8.3038-3040.2002] [Citation(s) in RCA: 111] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Integrons are strongly associated with the multidrug resistance seen in gram-negative bacilli in the hospital environment. No data, however, are available on their prevalence in the community. This study is the first to show that integrons are widespread in Enterobacteriaceae in the community and that integron-associated resistance genes in the community constitute a substantial reservoir for multidrug resistance in the hospital.
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Affiliation(s)
- M A Leverstein-Van Hall
- Eijkman-Winkler Institute for Microbiology, Infectious Diseases & Inflammation, University Medical Center, Utrecht, The Netherlands.
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48
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Rowe-Magnus DA, Mazel D. The role of integrons in antibiotic resistance gene capture. Int J Med Microbiol 2002; 292:115-25. [PMID: 12195734 DOI: 10.1078/1438-4221-00197] [Citation(s) in RCA: 164] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Although recently discovered, integrons have played a primordial role in the evolution of bacterial genomes. They are best known as the genetic agents responsible for the capture and spread of antibiotic resistance determinants among diverse Gram-negative clinical isolates, and this activity is at the root of the antibiotic resistance phenomenon that has evolved over the last 60 years. The discovery of the ancestral chromosomal super-integrons, novel integron classes, and the multitude of gene cassettes they propagate solidify the crucial role of this system in adaptive bacterial evolution. Recent evidence suggests that evolutionarily old genetic recombination mechanisms for gene transfer have been adapted to the new antibiotic environment due to the heavy selective pressure of liberal antibiotic use in human medicine and animal husbandry.
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Affiliation(s)
- Dean A Rowe-Magnus
- Department of Microbiology, Division of Clinical Integrative Biology, Sunnybrook and Women's College Hospital Health Sciences Centre Research Institute, Toronto, Canada
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49
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Sundsfjord A, Simonsen GS, Courvalin P. Human infections caused by glycopeptide-resistant Enterococcus spp: are they a zoonosis? Clin Microbiol Infect 2002; 7 Suppl 4:16-33. [PMID: 11688531 DOI: 10.1046/j.1469-0691.2001.00055.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Following the detection of glycopeptide-resistant enterococci (GRE) in 1986 and their subsequent global dissemination during the 1990s, many studies have attempted to identify the reservoirs and lines of resistance transmission as a basis for intervention. The eradication of reservoirs and the prevention of GRE spread is of major importance for two reasons: (i) the emergence of high-level glycopeptide resistance in invasive enterococcal clinical isolates that are already multiresistant, has left clinicians with therapeutic options that are only at the experimental stage; and (ii) the resistance genes may spread to more virulent bacterial species such as Staphylococcus aureus, Streptococcus pneumoniae and Clostridium difficile. VanA-type strains, resistant to high levels of both vancomycin and teicoplanin, are the most commonly encountered enterococci with acquired glycopeptide resistance in humans. A widespread VanA-type GRE reservoir was detected early in farm animals that were exposed to the glycopeptide growth-promoter avoparcin. Numerous studies have provided indirect evidence for the transfer of VanA-type GRE and their resistance determinants from animal reservoirs to humans. The data collected have expanded our understanding of the promiscuous nature of antibiotic resistance, and have provided the groundwork for logical decision-making with the objective of deterring the dissemination of resistant bacteria and of their resistance genes.
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Affiliation(s)
- A Sundsfjord
- Unité des Agents Antibactériens, Institut Pasteur, Paris, France.
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50
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Rowe-Magnus DA, Guerout AM, Mazel D. Bacterial resistance evolution by recruitment of super-integron gene cassettes. Mol Microbiol 2002; 43:1657-69. [PMID: 11952913 DOI: 10.1046/j.1365-2958.2002.02861.x] [Citation(s) in RCA: 153] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The capture and spread of antibiotic resistance determinants by integrons underlies the rapid evolution of multiple antibiotic resistance among diverse Gram-negative clinical isolates. The association of multiple resistance integrons (MRIs) with mobile DNA elements facilitates their transit across phylogenetic boundaries and augments the potential impact of integrons on bacterial evolution. Recently, ancestral chromosomal versions, the super-integrons (SIs), were found to be genuine components of the genomes of diverse bacterial species. SIs possess evolutionary characteristics and stockpiles of adaptive functions, including cassettes related to antibiotic resistance determinants previously characterized in clinical isolates, which suggest that MRIs and their resistance genes were originally recruited from SIs and their pool of amassed genes. However, the recombination activity of integrons has never been demonstrated in a bacterium other than Escherichia coli. We introduced a naturally occurring MRI (TpR, SulR) on a conjugative plasmid into Vibrio cholerae, a species known to harbour a SI. We show that MRIs can randomly recruit genes directly from the cache of SI cassettes. By applying a selective constraint for the development of antibiotic resistance, we demonstrate bacterial resistance evolution through the recruitment a novel, but phenotypically silent, chloramphenicol acetyltransferase gene from the V. cholerae SI and its precise insertion into the MRI. The resulting resistance profile (CmR, TpR, SulR) could then be disseminated by conjugation to other clinically relevant pathogens at high frequency. These results demonstrate that otherwise phenotypically sensitive strains may still be a genetic source for the evolution of resistance to clinically relevant antibiotics through integron-mediated recombination events.
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Affiliation(s)
- Dean A Rowe-Magnus
- Unité de Programmation Moléculaire et Toxicologie Génétique, CNRS URA 1444, Département des Biotechnologies, Institut Pasteur, 25 rue du Dr Roux, 75724 Paris, France
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