characterization of β-lactamases from urinary isolates of escherichia coli in tehran
نویسندگان
چکیده
knowledge of antimicrobial resistance patterns in e. coli, the predominant pathogen associated with urinary tract infections (uti) is important as a guide in selecting empirical antimicrobial therapy. methods: to describe the antimicrobial susceptibility of e. coli associated with uti in a major university hospital in tehran (iran), seventy-six clinical isolates of e. coli were studied for susceptibility to b-lactam antibiotics by the disc diffusion method and minimal inhibitory concentrations determination. results: all isolates were resistant to ampicillin, amoxicillin and oxacillin. resistance to the other tested antibiotics was shown to be 93.4% to cefradine, 76.3% to carbenicillin, 47.3% to cefazoline, 50% to cefalexin and 32.8% to cephalothin while 1.3% expressed resistance to cefoxitime, and 2.6% were resistant to ceftizoxime and ceftriaxone. two isolates (2.4%) harbored extended spectrum b-lactamases (esbl) shown by the double disc diffusion method. substrate hydrolysis by ultra violet spectroscopy showed that 87.4% harbored penicillinases, 9% produced cephlosporinases and 3.6% degraded both substrates. clavulanic acid inhibited enzyme activity in 82.9%, of which 78.95% was penicillinases (group iia) and 3.95% was cephalosporinases (group iib) of the bush classification system. the rest of the isolates (6.58 %) were placed in group iv b-lactamases. no group iii b-lactamase was found, as edta inhibited none of the enzymes. dna amplification by polymerase chain reaction using specific primers for ampc, tem and shv type b-lactamases for all of the isolates showed that 47 organisms (60%) carried the tem gene and 18 isolates (24%) harbored blatem and ampc genes. about 26% of the organisms harbored shv type enzymes. conclusion: these results indicate that e. coli can posses a variety of b-lactamases that are responsible for β-lactam resistance.
منابع مشابه
Characterization of β-Lactamases from Urinary Isolates of Escherichia coli in Tehran
Knowledge of antimicrobial resistance patterns in E. coli, the predominant pathogen associated with urinary tract infections (UTI) is important as a guide in selecting empirical antimicrobial therapy. Methods: To describe the antimicrobial susceptibility of E. coli associated with UTI in a major university hospital in Tehran (Iran), seventy-six clinical isolates of E. coli were studied for susc...
متن کاملCharacterization of beta-lactamases from urinary isolates of Escherichia coli in Tehran.
BACKGROUND Knowledge of antimicrobial resistance patterns in E. coli, the predominant pathogen associated with urinary tract infections (UTI) is important as a guide in selecting empirical antimicrobial therapy. METHODS To describe the antimicrobial susceptibility of E. coli associated with UTI in a major university hospital in Tehran (Iran), seventy-six clinical isolates of E. coli were stud...
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background beta-lactam resistance in gram-negative bacteria, especially escherichia coli, is a main clinical problem. it is often caused by the co-production of β-lactamases, particularly extended-spectrum β-lactamases (esbls) and ampc enzymes. it may lead to a problem for diagnosis via recommended phenotypic tests by the clinical and laboratory standards institute (clsi). conversely, β-lactama...
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This study was conducted to reveal the phylogenetic background, to detect the genes encoding TEM, SHV and CTX-M-15 extended-spectrum β-lactamases (ESBL), and to analyze their distribution in phylo-groups of 150 Escherichia coli isolates from broiler chickens in Ahvaz (Southwest of Iran). Seventy- five cloacal swabs from healthy birds (fecal isolates), and 75 heart blood samples from bi...
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Background & objectives: Urinary tract infection (UTI) is one of the most common types of human infections and Escherichia coli and Klebsiella pneumonia are the main causes of urinary tract infection among the gram negative bacteria. The prevalence of extended-spectrum β-lactamases (ESBLs) among these bacteria and hence resistant strains to β-lactam antibiotics have increased in recent decades...
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عنوان ژورنال:
iranian biomedical journalجلد ۱۱، شماره ۲، صفحات ۹۵-۹۹
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