High prevalence of blaCTX-M in Enterobacteriaceae isolates from the Kingdom of Bahrain

OBJECTIVE@#To determine the molecular epidemiology of extended-spectrum β-lactamase (ESBL) by testing a cohort of clinical ESBL-producing bacterial isolates that were isolated in the Kingdom of Bahrain.@*METHODS@#ESBL producing Enterobacteriaceae isolates (based on phenotypic tests) were collected from Microbiology Laboratory of the Salmaniya Medical Complex, Bahrain between January-June 2006. Antibiotic susceptibility to a panel of antibiotics was performed and bla(CTX-M) genes were detected by multiplex PCR.@*RESULTS@#A total of 230 isolates (Escherichia coli, n=180; Klebsiella pneumoniae, n=50) were studied, 98% were CTX-M type. For Escherichia coli isolates, 65 (36.1%) harbored CTXM+TEM combination and 68 (37.8%) had CTX-M alone. In contrast, for Klebsiella pneumoniae isolates only 5 (10.0%) harbored the CTX-M combination, and none had CTX-M only. The bla(CTX-M) gene was found predominantly in urine isolates (n=145/230; 63.0%). Sensitivity to imipenem and nitrofurantoin was 100% and 60%, respectively. CTX-M carriage was associated with the resistance to fluoroquinolones, trimethoprim-sulfamethoxazole and aminoglycosides.@*CONCLUSIONS@#Our study documentes high prevalence of CTX-M ESBL type among Escherichia coli and Klebsiella from the Kingdom of Bahrain. The apparent dissemination of CTX-M producers could represent a substantial barrier in the treatment of community-acquired infections. The use of extended-spectrum cephalosporins, quinolones, and aminoglycosides is compromised, leaving carbapenems as the therapeutic option for severe infections caused by ESBL producers.

Predominance of CTX-M genotype among extended spectrum beta lactamase isolates in a tertiary hospital in Saudi Arabia

To determine the molecular characterization of extended-spectrum beta-lactamases [ESBL] isolates from a tertiary center in Saudi Arabia using multiplex polymerase chain reaction [PCR] technique and assess their antibiotic susceptibility pattern. Prospective study conducted at the Saudi Aramco Dhahran Health Center, Dhahran, Saudi Arabia between April-December 2006. Extended-spectrum beta-lactamases phenotype of isolates identified by automated methods was confirmed using E-test. Multiplex PCR for the detection of blaTEM, blaSHV and blaCTX-M was performed. Susceptibility to a panel of antibiotics was determined. One hundred isolates [Escherichia coli [E.coli] n=84; Klebsiella pneumoniae [K. pneumoniae] n=16] were studied and 71% harbored the blaCTX-M gene. For E.coli isolates 43 [51%] harbored CTX-M+TEM combination and 21 [25%] had CTX-M alone. In contrast, only one K. pneumoniae isolate [6.2%] harbored the CTX-M+TEM combination and 3 [18.8%] isolates had CTX-M only. One E.coli and 7 K. pneumoniae isolates were blaSHV positive. The blaCTX-M gene was found predominantly in urinary isolates [n=63/71; 88.7%]. The presence of blaCTX-M was significantly higher in isolates from outpatients compared to inpatient [p<0.05]. Sensitivity to imipenem was 100% and 78% to nitrofurantoin. Resistance to amoxicillin-sulbactam was significantly higher in blaCTX-M positive isolates [p<0.05]. The findings indicate a high-level of blaCTX-M positive ESBL isolates circulating in our setting with the dissemination of these in the community. The trend of multidrug resistance profile associated with carriage of blaCTX-M gene is cause for concern

Neonatal sepsis 1991-2001: prevalent bacterial agents and antimicrobial susceptibilities in Bahrain

To investigate the organisms causing neonatal sepsis and their modifications over an extended period, to assess their changing sensitivities to antibiotics and to verify whether the policy for screening pregnant women for group B streptococci [GBS] carriage is desirable in our settings. Medical records of all infants with positive blood culture from the Neonatal Intensive Care Unit at Salmaniya Medical Complex between 1991 and 2001 and Bahrain Defense Force Hospital between 1999 and 2001 were reviewed. Of the 7,978 neonates in both hospitals 335 [4.19%] had culture-proven bacteremia. Gram-positive bacteria were isolated at constant rate over the 11-year period. The main agents isolated were coagulase-negative Staphylococcus [CoNS] in 138 cases [41%], Staphylococcus aureus in 28 newborns [8%] and GBS in 26 patients [7.8%, 0.2/1,000 live births]. All of them were sensitive to penicillin G, erythromycin and clindamycin. Gram-negative bacteria were declining but Escherichia coli was isolated in 35 cases [10%]. Of special concern is the increasing percentage [5.7%] of Candida isolation. No clear trend toward increasing resistance was observed, although a major difference among the two institutions was evident. Klebsiella and Enterobacter spp. showed resistance to many of the antibiotics tested, thereby posing difficult therapeutic choices. Good quality specimens are essential to evaluate the role of CoNS. The increasing threat of fungal infection must be carefully tackled. Specifically tailored policies for GBS prevention must be defined according to the local epidemiology

Antibiotic susceptibilities of helicobacter pylori

The aim of this study was to evaluate the prevalence of resistance among 83 Helicobacter pylori isolates cultured from biopsies taken during routine endoscopies in 1998-1999. Minimum Inhibitory Concentration of amoxicillin, tetracycline, clarithromycin and metronidazole were determined by Epsilometer test. Forty-seven strains [57%] were resistant to metronidazole, and 27 [32.5%] were resistant to clarithromycin. Twenty of the 27 strains resistant to clarithromycin were also resistant to metronidazole. None of the strains were resistant to amoxicillin or tetracycline. A high percentage of patients from Bahrain were infected with resistant strains of Helicobacter pylori. Antibiotic resistance monitoring is very important and unified national treatment policies are needed