Microbiology
Sorour Farzi; Reza Ranjbar; Mohammad Niakan; Mohammad Hossein Ahmadi
Abstract
Background & Objective: Escherichia coli (E. coli) is a leading cause of urinary tract infections becoming resistant against beta-lactams and cephalosporins through different mechanisms, including ESBL production due to the presence of ESBL specific genes, including blaCTX-M and blaTEM. The purpose ...
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Background & Objective: Escherichia coli (E. coli) is a leading cause of urinary tract infections becoming resistant against beta-lactams and cephalosporins through different mechanisms, including ESBL production due to the presence of ESBL specific genes, including blaCTX-M and blaTEM. The purpose of the present study was to detect the uropathogenic E. coli strains producing the ESBL.Methods: A total of 100 isolates of uropathogenic E. coli were randomly selected in a period of 6 months and their resistances to a number of antibiotics including amoxicillin, amikacin, gentamicin, ciprofloxacin, ceftazidime, cefotaxime, ceftriaxone, ceftizoxime, nalidixic acid, and nitrofurantoin were determined. Then, DDT test was used to detect the presence of ESBL. Finally, the presence of blaCTX-M and blaTEM resistance genes was analyzed by PCR method.Results: The resistance profile of bacterial isolates to the antibiotics was as follows: amoxicillin: 16.7%, amikacin: 7.8%, gentamicin: 20.3%, ciprofloxacin: 35.5/%, ceftazidime: 35.0%, cefotaxime: 40.0%, ceftriaxone: 41.3%, nalidixic acid: 64.0%, nitrofurantoin: 9.7%, and ceftizoxime: 100%. Of these, 28 isolates (28%) were reported to be resistant to cefotaxime, ceftazidime, and ceftriaxone. In DDT test, 21 ESBL positive cases (21%) were detected. PCR results showed that the presence of blaCTX-M and blaTEM genes in the isolates were 21% and 20%, respectively. Conclusion: Regarding the production of ESBL by some E. coli isolates, phenotypic detection of ESBL-producing isolates is routinely suggested in the laboratories. Likewise, the treatment regimen should be selected regarding the ESBL production to avoid treatment failure.
Fatemeh Fattahi; Alireza Mirvaghefi; Hamid Farahmand; Gholamreza Rafiee; Alireza Abdollahi
Volume 8, Issue 1 , January 2013, , Pages 36-44
Abstract
Objectives: The presence of E.coli in fish intended for human consumption may constitute a potential danger, not only in causing disease, but also because of the possible transfer of antibiotic resistance from aquatic bacteria to those infecting humans. The objective of this study was to develop ...
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Objectives: The presence of E.coli in fish intended for human consumption may constitute a potential danger, not only in causing disease, but also because of the possible transfer of antibiotic resistance from aquatic bacteria to those infecting humans. The objective of this study was to develop an improved PCR method based on species – specific 16 S rRNA gene primers (FES, RES) for detection of E. coli from agar plates and fish tissues.
Materials and Methods: In this study, For the rapid detection of E .coli from fish a set of primers (FES, RES), targeting 16S rRNA gene sequences of the specific microorganism was designed, and fifty two rainbow trout were obtained from Karaj fish farm. Then 1mL of bacterial concentration of 106CFU/ml was injected into intraperitoneal cavity. Samples were collected from liver and kidney after 48h injection. The PCR reaction conditions were optimized to permit detection of organism from agar plates and fish tissue in a day.
Results: All tissue samples were positive for microbiological and PCR identification. DNA was successfully extracted by a boiled – extraction method or by phenol – chloroform – isoamyl alcohol. The BLAST analysis from sequencing of 4 amplicons randomly selected showed similar results, with the match being E .coli with a 100% similarity (not shown here).
Conclusion: It is concluded that this method is fast, specific and sensitive to detect E.coli in infected and asymptomatic animals, fish product, and may have a positive impact on public and environmental health.
Nasrin Shayanfar; Mitra Rezaei; Mehdi Ahmadi
Volume 5, Issue 1 , January 2010, , Pages 34-39
Abstract
Background and Objective: To evaluate extended spectrum betalactamase (ESBL) positive strains of Klebsiella pneumonia and Escherichia coli in positive bacterial cultures. Materials and Methods: In this analytical cross-sectional study, between March 2006 and March 2007, 170 bacterial isolates ...
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Background and Objective: To evaluate extended spectrum betalactamase (ESBL) positive strains of Klebsiella pneumonia and Escherichia coli in positive bacterial cultures. Materials and Methods: In this analytical cross-sectional study, between March 2006 and March 2007, 170 bacterial isolates including 133 cases of E. coli and 37cases of K. pneumonia were examined. All cases underwent double disk diffusion for ESBL. Demographic data were assessed and all data analyzed accordingly. Results: Patients’ mean age was 55±26.63 yr. Ninety six cases (56.5%) were female and 74 cases (43.5%) were male. Clinical presentation of infection were 118 cases UTI (96.4%), 15 cases septicemia (8.8%), 16cases wound infection (9.4%), 7 cases pneumonia (4.1%), 1 case meningitis (0.6%) and 13 cases other presentations (7.6%). Frequency of ESBL positive in E. coli isolates was 38 cases (28.6%) and in K. pneumonia isolates was 10 cases (27%). There was no significant correlation between ESBL positivity and age, gender, ward or clinical presentation of infection. Conclusion: Incidence of ESBL positive isolates of E. coli and K. pneumonia was high. These results should be considered in administration of broad-spectrum antibiotics by clinicians.
