Prevalence and antimicrobial susceptibility pattern of extended-spectrum beta-lactamase-producing enterobacteriaceae in the United Arab Emirates

ABSTRACT

To investigate the prevalence and antibiotic susceptibility pattern of extended-spectrum beta-lactamases [ESBL]-producing Enterobacteriaecae among patients in the United Arab Emirates. A total of 130 Enterobacteriaceae comprising of Escherichia coli [n = 83], Klebsiella pneumoniae [n = 45] and Klebsiella oxytoca [n = 2] was studied. Of these 130 isolates, 64 were from urine. ESBL screening was by disc diffusion and confirmatory tests for ESBL phenotype were conducted using BD Phoenix[TM] ESBL System and cephalosporin/clavulanate combination discs. Susceptibility to a panel of antibiotics was evaluated. Of the 130 isolates, 53 [41%] were identified as having ESBL phenotype; of these, 32 [60%] were E. coli, 20 [36%] K. pneumoniae and 2 [4%] K. oxytoca. ESBL phenotype was seen in 100% of endotracheal tubes isolates, 20 [31%] from urine, 7 [58%] from blood and 4 [80%] from catheter tips. Amikacin susceptibility was 100%. Over 90% of ESBL isolates showed resistance to aztreonam and cephalosporins. All Klebsiella isolates were carbapenem sensitive. One ESBL isolate showed intermediate resistance to imipenem and meropenem [both MIC 8 micro g/ml], cefotetan [MIC 32 micro g/ml] and piperacillin/ tazobactam [MIC 32 micro g/ml]. MIC for the carbapenems was lower in non-ESBL isolates [0.034 micro g/ml] than ESBL isolates [0.071 micro g/ml]. Resistance to gentamicin, ciprofloxacin and piperacillin/tazobactam was higher in ESBL than non-ESBL isolates [p < 0.05]. A high prevalence of ESBL-producing bacteria exists among in-patients in the United Arab Emirates. Amikacin and carbapenems remain the most effective drugs, but the presence of carbapenem-resistant ESBL-producing E. coli and occurrence of multidrug resistance are of concern. Continued surveillance and judicious antibiotic usage are recommended