scholarly journals Usefulness of Pulsed Field Gel Electrophoresis Assay in the Molecular Epidemiological Study of Extended Spectrum Beta Lactamase Producers

Author(s):  
Patrick Eberechi ◽  
Padman Jayaratne
2009 ◽  
Vol 20 (suppl a) ◽  
pp. 43A-48A ◽  
Author(s):  
Patricia J Baudry ◽  
Melissa McCracken ◽  
Philippe Lagacé-Wiens ◽  
Michael R Mulvey ◽  
George G Zhanel ◽  
...  

OBJECTIVE: The purpose of the present study was to determine the prevalence and molecular epidemiology of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae identified from Canadian hospitals in 2007. METHODS: Clinically significant isolates were collected as part of the Canadian Ward Surveillance Study (CANWARD 2007) from January to December 2007, inclusive, from 12 sentinel hospital centres across Canada. Minimum inhibitory concentrations were determined by broth microdilution, and putative ESBL isolates were confirmed by the Clinical and Laboratory Standards Institute disk diffusion method. Polymerase chain reaction and DNA sequencing were used to detectblaSHV,blaTEM,blaCTX-MandblaOXA-likegenes. Strains were typed using pulsed-field gel electrophoresis. RESULTS: A total of 3.4% and 1.6% ofEscherichia coliandKlebsiella pneumoniae, respectively, were identified as ESBL producers. Resistance to fluoroquinolones, doxycycline, trimethoprim/sulfamethoxazole and gentamicin occurred in 92.5% and 71.4%, 75.5% and 71.4%, 67.9% and 57.1%, and 58.5% and 57.1% of ESBL-producingE coliandK pneumoniae, respectively. A total of 90.6% and 71.4% of ESBL-producingE coliandK pneumoniaewere identified as multidrug resistant. The CTX-M type was the predominant ESBL, with CTX-M-15 as the predominant genotype. A total of 81.7% ESBL-producers carried several beta-lactamase genes. Pulsed-field gel electrophoresis revealed that the majority of ESBL producers were not genetically related (less than 80% homology). Similar patient demographics were observed among both ESBL-producingE coliand K pneumoniae. CONCLUSION: CTX-M has become the most common enzyme among both ESBL-producingE coliandK pneumoniae. The spread of ESBLproducing bacteria across Canada is polyclonal and is not due to the clonal spread of a single strain.


2017 ◽  
Vol 71 (1) ◽  
pp. 0-0
Author(s):  
Patrycja Zalas-Więcek ◽  
Tomasz Bogiel ◽  
Krzysztof Wiśniewski ◽  
Eugenia Gospodarek-Komkowska

Introduction: The aim of the study was to evaluate genetic relatedness and antimicrobial susceptibility of extended-spectrum beta-lactamase-producing E. coli strains isolated from patients hospitalized in the University Hospital in Bydgoszcz (Poland).Material and methods: The study included 33 extended-spectrum beta-lactamase-producing E. coli strains isolated from 31 patients. The chromosomal DNA was extracted from the strains and separated by pulsed-field gel electrophoresis. Antimicrobial susceptibility testing was performed by the agar dilution method and carried out according to the European Committee on Antimicrobial Susceptibility Testing recommendations.Results: According to the pulsed-field gel electrophoresis results, 32 distinct pulsotypes were revealed. Based on Molecular Analyst Fingerprinting software analysis, the studied isolates were divided into four subgroups: 6 (18.2%) isolates showing similarity greater than 90% (group A); 19 (57.6%) showing 80-90% similarity (group B); 7 (21.2%) showing 70-79% similarity (group C); and one isolate with less than 70% similarity (group D). Among E. coli isolates showing similarity greater than 90%, four antimicrobial patterns were noted. Among the isolates showing 80-90% similarity, 18 antimicrobial patterns were observed. E. coli isolates showing 70-79% similarity presented 6 antimicrobial patterns.Conclusions: Our results show a high degree of genetic diversity of extended-spectrum beta-lactamase-producing E. coli isolates. However, based on a similarity of ≥80%, almost 75% of E. coli isolates were clonally related. Although it is difficult to identify definitive transmission events based on the recovery of indistinguishable pulsed-field gel electrophoresis types alone, we speculate that extended-spectrum beta-lactamase-producing E. coli strains may have disseminated throughout the hospital.


2010 ◽  
Vol 54 (6) ◽  
pp. 2687-2691 ◽  
Author(s):  
Moran G. Goren ◽  
Shiri Navon-Venezia ◽  
Inna Chmelnitsky ◽  
Yehuda Carmeli

ABSTRACT All of the carbapenem-resistant Escherichia coli (CREC) isolates identified in our hospital from 2005 to 2008 (n = 10) were studied. CREC isolates were multidrug resistant, all carried bla KPC-2, and six of them were also extended-spectrum beta-lactamase producers. Pulsed-field gel electrophoresis indicated six genetic clones; within the same clone, similar transferable bla KPC-2-containing plasmids were found whereas plasmids differed between clones. Tn4401 elements were identified in all of these plasmids.


2013 ◽  
Vol 76 (1) ◽  
pp. 18-25 ◽  
Author(s):  
J. S. VAN KESSEL ◽  
J. SONNIER ◽  
S. ZHAO ◽  
J. S. KARNS

Salmonella isolates were recovered from bulk tank milk as part of the National Animal Health Monitoring System (NAHMS) Dairy 2002 and 2007 surveys. In-line milk filters were also tested in the 2007 survey. The objective of this study was to determine the prevalence of antimicrobial resistance among Salmonella enterica isolates from bulk milk and milk filters in the NAHMS Dairy 2002 and 2007 surveys and to further characterize resistant isolates. Susceptibilities to 15 antibiotics were determined for 176 Salmonella isolates of 26 serotypes using an automated antimicrobial susceptibility system. Resistant isolates were screened by PCR for the presence of the extended-spectrum β-lactamase (blaCMY) gene and class I integrons and further characterized by pulsed-field gel electrophoresis. Thirty isolates (17.0%) representing six S. enterica serotypes exhibited resistance to at least one antimicrobial agent (serotypes Newport [14 of 14 isolates exhibited resistance], Dublin [7 of 7], Typhimurium [3 of 5], Kentucky [4 of 22], Anatum [1 of 13], and Infantis [1 of 2]). Twenty isolates (11.4%), including all 14 Newport, 3 Dublin, 2 Typhimurium, and 1 Infantis isolate, displayed the typical multidrug-resistant, blaCMY-positive (MDR-AmpC) phenotype which included resistance to ampicillin, chloramphenicol, streptomycin, sulfonamide, and tetracycline, plus resistance to amoxicillin–clavulanic acid and extended-spectrum cephalosporins. Five of the MDR-AmpC isolates carried class I integrons (2.8%). Two-enzyme (XbaI and BlnI) pulsed-field gel electrophoresis discerned clades within serotypes and, together with the resistance profiles, identified strains that appeared to have persisted temporally and geographically. These results suggest that there is a low but appreciable risk of infection with MDR Salmonella from consumption of nonpasteurized milk and dairy products.


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