Extended-spectrum beta-lactamase [ESBL] in Omani Children: Study of prevalence, risk factors and clinical outcomes at Sultan Qaboos University Hospital, Sultanate of Oman

Antimicrobial resistance is a growing problem worldwide, which imposes difficulties in the selection of appropriate empirical antimicrobial therapy. This study evaluated extended-spectrum ?-lactamase [ESBL] isolates in 2005 in The Department of Child Health at Sultan Qaboos University Hospital [SQUH], Oman. During the 12 month period from January 2005 to December 2005, ESBL isolates from paediatrics inpatients were identified and analysed. Risk factors for the patients who grew ESBLs were analysed. 13.3% of E. coli and 16.6% of Klebsiella pneumoniae isolated were ESBL producers. Most of the ESBLs were from urine [46.2%] and blood [42.6%]. The main risk factors for ESBL in these children were previous exposure to antimicrobials [100%], prolonged hospital stay, severe illness [92.3%] and female gender [84.6%]. Sensitivity of 100% was observed to carbapenems whereas 92% of the isolates were susceptible to amikacin. The oximino-cephalosporins were 100% resistant. Klebsiella pneumoniae were 100% resistant to piperacillin-tazobactam and nitrofurantoin. E. coli was 100% resistant to trimethoprim-sulfamethoxazole and ciprofloxacin. No resistance was recorded for the following combinations: amikacin plus piperacillin-tazobactam, amikacin plus nitrofurantoin and gentamicin plus nitrofurantoin. ESBL-producing organisms are becoming a major problem in Omani children. Exposure to antimicrobials and long admissions are modifiable risk factors that should be targeted for better control. Carbapenems are the most sensitive and reliable treatment options for infections caused by ESBLs. Amikacin plus piperacillin-tazobactam or nitrofurantoin are good alternatives

Prevalence of extended-spectrum beta-lactamases-producing isolates over a 1-year period at a University Hospital in Oman

To evaluate the prevalence of extended-spectrum beta-lactamases isolates over one year period at Sultan Qaboos University Hospital. We identified the ESBL isolates during a 12-month period from July 2004 to June 2005, using a commercial system, and confirmed the result using the National Committee for Clinical Laboratory Standards-approved double-disk diffusion method. Sensitivity was recorded for a wide range of antibiotics, aminoglycosides, carbapenem, cephalosporins, quinolones, aztreonam, ampicillin, amoxicillin/clavulanate, ampicillin/sulbactam, piperacillin-tazobactam, trimethoprim/ sulfamethoxazole and nitrofurantoin. Of the total ESBL isolated, 29.6% were from medical ward, followed by outpatients clinic, 24.3%. Urine was the main source of ESBLs 70.4%, followed by 16.5% from blood. We observed a 100% sensitivity to carbapenems, whereas 93.9% of the isolates were susceptible to amikacin. Cephalosporins were 100% resistant, except for cefoxitin, which demonstrated sensitivity of 77.4%. Aztreonam, ampicillin, co-amoxyclav and ampicillin/sulbactam were 100% resistant. Of the isolates, 57.4% were sensitive to nitrofurantoin, whereas Tazocin showed 49.6% sensitivity and co-trimoxazole 13.9%. To quinolones, 74.8% of the isolates were resistant. Excess use of third generation cephalosporins led to increase rate of ESBLs, which are difficult to treat. Carbapenem are most reliable for treatment of infections caused by ESBL isolates. However, overuse of carbapenem may lead to resistance of other gram-negative organisms. Therefore, justifiable use of third-generation cephalosporins, will be an effective means of controlling and decreasing the spread of ESBL isolates