{"title":"质粒介导的AmpC β-内酰胺酶活性在肺炎克雷伯菌和大肠杆菌中共现","authors":"Abdulaziz Zorgani, Hiyam Daw, Najib Sufya, Abdullah Bashein, Omar Elahmer, Chedly Chouchani","doi":"10.2174/1874285801711010195","DOIUrl":null,"url":null,"abstract":"<p><strong>Introduction: </strong>Extended-spectrum β-lactamases (ESBLs), including the AmpC type, are important mechanisms of resistance among <i>Klebsiella pneumoniae</i> and <i>Escherichia coli</i> isolates.</p><p><strong>Objective: </strong>The aim of the study was to investigate the occurrence of AmpC-type β-lactamase producers isolated from two hospitals in Tripoli, Libya.</p><p><strong>Methods: </strong>All clinical isolates (76 <i>K. pneumoniae</i> and 75 <i>E. coli</i>) collected over two years (2013-2014) were evaluated for susceptibility to a panel of antimicrobials and were analyzed phenotypically for the ESBL and AmpC phenotype using E-test and ESBL and AmpC screen disc test. Both ESBL and AmpC-positive isolates were then screened for the presence of genes encoding plasmid-mediated AmpC β-lactamases by polymerase chain reaction (PCR).</p><p><strong>Results: </strong>Of the <i>K. pneumoniae</i> and <i>E. coli</i> tested, 75% and 16% were resistant to gentamicin, 74% and 1.3% to imipenem, 71% and 12% to cefoxitin, 80% and 12% to cefepime, 69% and 22.6% to ciprofloxacin, respectively. None of the <i>E. coli</i> isolates were multidrug resistant compared with <i>K. pneumoniae</i> (65.8%). <i>K. pneumoniae</i> ESBL producers were significantly higher (85.5%) compared with (17.3%) <i>E. coli</i> isolates (P <0.0001, OR=4.93). Plasmid-mediated AmpC genes were detected in 7.9% of <i>K. pneumoniae</i>, and 4% <i>E. coli</i> isolates. There was low agreement between phenotypic and genotypic methods, phenotypic testing underestimated detection of AmpC enzyme and did not correlate well with molecular results. The gene encoding CMY enzyme was the most prevalent (66.6%) of AmpC positive isolates followed by MOX, DHA and EBC. Only one AmpC gene was detected in 5/9 isolates, i.e, <i>bla</i><sub>CMY</sub> (n=3), <i>bla</i><sub>MOX</sub> (n=1), <i>bla</i><sub>DHA</sub> (n=1). However, co-occurrence of AmpC genes were evident in 3/9 isolates with the following distribution: <i>bla</i><sub>CMY</sub> and <i>bla</i><sub>EBC</sub> (n=1), and <i>bla</i><sub>CMY</sub> and <i>bla</i><sub>MOX</sub> (n=2). Neither <i>bla</i><sub>FOX</sub> nor <i>bla</i><sub>ACC</sub> was detected in all tested isolates. All AmpC positive strains were resistant to cefoxitin and isolated from patients admitted to intensive care units.</p><p><strong>Conclusion: </strong>Further studies are needed for detection of other AmpC variant enzyme production among such isolates. Continued surveillance and judicious antibiotic usage together with the implementation of efficient infection control measures are absolutely required.</p>","PeriodicalId":38953,"journal":{"name":"Open Microbiology Journal","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2017-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5678236/pdf/","citationCount":"21","resultStr":"{\"title\":\"Co-Occurrence of Plasmid-Mediated AmpC β-Lactamase Activity Among <i>Klebsiella pneumoniae</i> and <i>Escherichia Coli</i>.\",\"authors\":\"Abdulaziz Zorgani, Hiyam Daw, Najib Sufya, Abdullah Bashein, Omar Elahmer, Chedly Chouchani\",\"doi\":\"10.2174/1874285801711010195\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><strong>Introduction: </strong>Extended-spectrum β-lactamases (ESBLs), including the AmpC type, are important mechanisms of resistance among <i>Klebsiella pneumoniae</i> and <i>Escherichia coli</i> isolates.</p><p><strong>Objective: </strong>The aim of the study was to investigate the occurrence of AmpC-type β-lactamase producers isolated from two hospitals in Tripoli, Libya.</p><p><strong>Methods: </strong>All clinical isolates (76 <i>K. pneumoniae</i> and 75 <i>E. coli</i>) collected over two years (2013-2014) were evaluated for susceptibility to a panel of antimicrobials and were analyzed phenotypically for the ESBL and AmpC phenotype using E-test and ESBL and AmpC screen disc test. Both ESBL and AmpC-positive isolates were then screened for the presence of genes encoding plasmid-mediated AmpC β-lactamases by polymerase chain reaction (PCR).</p><p><strong>Results: </strong>Of the <i>K. pneumoniae</i> and <i>E. coli</i> tested, 75% and 16% were resistant to gentamicin, 74% and 1.3% to imipenem, 71% and 12% to cefoxitin, 80% and 12% to cefepime, 69% and 22.6% to ciprofloxacin, respectively. None of the <i>E. coli</i> isolates were multidrug resistant compared with <i>K. pneumoniae</i> (65.8%). <i>K. pneumoniae</i> ESBL producers were significantly higher (85.5%) compared with (17.3%) <i>E. coli</i> isolates (P <0.0001, OR=4.93). Plasmid-mediated AmpC genes were detected in 7.9% of <i>K. pneumoniae</i>, and 4% <i>E. coli</i> isolates. There was low agreement between phenotypic and genotypic methods, phenotypic testing underestimated detection of AmpC enzyme and did not correlate well with molecular results. The gene encoding CMY enzyme was the most prevalent (66.6%) of AmpC positive isolates followed by MOX, DHA and EBC. Only one AmpC gene was detected in 5/9 isolates, i.e, <i>bla</i><sub>CMY</sub> (n=3), <i>bla</i><sub>MOX</sub> (n=1), <i>bla</i><sub>DHA</sub> (n=1). However, co-occurrence of AmpC genes were evident in 3/9 isolates with the following distribution: <i>bla</i><sub>CMY</sub> and <i>bla</i><sub>EBC</sub> (n=1), and <i>bla</i><sub>CMY</sub> and <i>bla</i><sub>MOX</sub> (n=2). Neither <i>bla</i><sub>FOX</sub> nor <i>bla</i><sub>ACC</sub> was detected in all tested isolates. All AmpC positive strains were resistant to cefoxitin and isolated from patients admitted to intensive care units.</p><p><strong>Conclusion: </strong>Further studies are needed for detection of other AmpC variant enzyme production among such isolates. Continued surveillance and judicious antibiotic usage together with the implementation of efficient infection control measures are absolutely required.</p>\",\"PeriodicalId\":38953,\"journal\":{\"name\":\"Open Microbiology Journal\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2017-09-26\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5678236/pdf/\",\"citationCount\":\"21\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Open Microbiology Journal\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.2174/1874285801711010195\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"2017/1/1 0:00:00\",\"PubModel\":\"eCollection\",\"JCR\":\"Q3\",\"JCRName\":\"Immunology and Microbiology\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Open Microbiology Journal","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.2174/1874285801711010195","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2017/1/1 0:00:00","PubModel":"eCollection","JCR":"Q3","JCRName":"Immunology and Microbiology","Score":null,"Total":0}
Co-Occurrence of Plasmid-Mediated AmpC β-Lactamase Activity Among Klebsiella pneumoniae and Escherichia Coli.
Introduction: Extended-spectrum β-lactamases (ESBLs), including the AmpC type, are important mechanisms of resistance among Klebsiella pneumoniae and Escherichia coli isolates.
Objective: The aim of the study was to investigate the occurrence of AmpC-type β-lactamase producers isolated from two hospitals in Tripoli, Libya.
Methods: All clinical isolates (76 K. pneumoniae and 75 E. coli) collected over two years (2013-2014) were evaluated for susceptibility to a panel of antimicrobials and were analyzed phenotypically for the ESBL and AmpC phenotype using E-test and ESBL and AmpC screen disc test. Both ESBL and AmpC-positive isolates were then screened for the presence of genes encoding plasmid-mediated AmpC β-lactamases by polymerase chain reaction (PCR).
Results: Of the K. pneumoniae and E. coli tested, 75% and 16% were resistant to gentamicin, 74% and 1.3% to imipenem, 71% and 12% to cefoxitin, 80% and 12% to cefepime, 69% and 22.6% to ciprofloxacin, respectively. None of the E. coli isolates were multidrug resistant compared with K. pneumoniae (65.8%). K. pneumoniae ESBL producers were significantly higher (85.5%) compared with (17.3%) E. coli isolates (P <0.0001, OR=4.93). Plasmid-mediated AmpC genes were detected in 7.9% of K. pneumoniae, and 4% E. coli isolates. There was low agreement between phenotypic and genotypic methods, phenotypic testing underestimated detection of AmpC enzyme and did not correlate well with molecular results. The gene encoding CMY enzyme was the most prevalent (66.6%) of AmpC positive isolates followed by MOX, DHA and EBC. Only one AmpC gene was detected in 5/9 isolates, i.e, blaCMY (n=3), blaMOX (n=1), blaDHA (n=1). However, co-occurrence of AmpC genes were evident in 3/9 isolates with the following distribution: blaCMY and blaEBC (n=1), and blaCMY and blaMOX (n=2). Neither blaFOX nor blaACC was detected in all tested isolates. All AmpC positive strains were resistant to cefoxitin and isolated from patients admitted to intensive care units.
Conclusion: Further studies are needed for detection of other AmpC variant enzyme production among such isolates. Continued surveillance and judicious antibiotic usage together with the implementation of efficient infection control measures are absolutely required.
期刊介绍：
The Open Microbiology Journal is a peer-reviewed open access journal which publishes research articles, reviews/mini-reviews, case studies, guest edited thematic issues and short communications/letters covering theoretical and practical aspects of Microbial systematics, evolutionary microbiology, immunology, virology, parasitology , bacteriology, mycology, phycology, protozoology, microbial ecology, molecular biology, microbial physiology, biochemistry, microbial pathogenesis, host-microbe interaction, systems microbiology, synthetic microbiology, bioinformatics. The Open Microbiology Journal , a peer-reviewed journal, is an important and reliable source of current information on developments in the field. The emphasis will be on publishing quality papers rapidly and freely available to researchers worldwide.
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