Prevalence of extended-spectrum beta -lactamases-producing Escherichia coli from hospitals in Khartoum state, Sudan

This study aimed to determine the prevalence and assess antimicrobial susceptibility of extended- spectrum beta -lactamase-producing Escherichia coli isolated from clinical specimens of patients at hospitals in Khartoum State, Sudan. During April to August 2011, a total of 232 E. coli isolates were collected from various clinical specimens of patients. Isolates were identified, tested for antimicrobial susceptibility and screened for ESBL production as per standard methods. The double-disk diffusion method was used to confirm ESBL production using antimicrobial disks of ceftazidime [30 micro g], cefotaxime [30 micro g], with or without clavulanic acid [10 micro g]. A zone difference of >5 mm between disks was considered indicative of ESBL production. Out of 232 E. coli isolates, 70 [30.2%] were found to be positive for ESBL by the applied phenotypic methods. ESBL-producing isolates yielded high resistance rates for trimethoprim-sulfamethoxazole [98.6%], tetracycline [88.6%], nalidixic acid [81.4%] and ciprofloxacin [81.4%]. The highest antimicrobial activities of ESBL-producing isolates were observed for amikacin [95.7%], followed by tobramicin [74.3%] and nitrofurantoin [68.6%]. Resistance to quinolones, aminoglycosides, trimethoprim-sulfamethoxazole, tetracycline, nitrofurantoin and chloramphenicol was higher in ESBL than non-ESBL isolates [p<0.05]. The frequency of ESBL-producing isolates varied among hospitals [18.2% to 45.1%], although a high prevalence was recorded as 45.1% at Khartoum Teaching Hospital. Wound specimens were the most common source of ESBL-producing isolates. The proportion of ESBL-producing E. coli did not differ significantly between adults and children [31% vs. 27%]. The prevalence of ESBL-producing E. coli detected in this study is of great concern, which requires sound infection control measures including antimicrobial management and detection of ESBL-producing isolates

Distribution of class I integrons and their effect on the prevalence of multi-drug resistant Escherichia coli clinical isolates from Sudan

To analyze integrons gene cassettes Class I among Escherichia coli [E. coli] isolates from Sudan and to determine their effect on the prevalence of resistance to antimicrobials. This cross-sectional study was conducted at 6 hospitals in Khartoum State, Sudan between April and August 2011. Escherichia coli [n=133] isolated from clinical specimens of patients were included. Isolates were identified and tested for antimicrobial susceptibility following standard procedures. Multi-drug resistance [MDR] patterns was defined as non-susceptibility to >/= 3 antimicrobials. Class I integrons was detected by polymerase chain reaction, and gene cassettes were characterized via sequencing analysis. Of the 133 E. coli isolates, 40.6% [n=54] harbored Class I integrons. All the 54 integron carriage, E. coli was found to be MDR strains. Integron carriage isolates confer higher levels of resistance than any other isolates [p<0.05] such as amoxicillin-clavulanic acid [66.7% versus 36.7%], ceftazidime [46.3% versus 17.7%], chloramphenicol [29.6% versus 7.6%], ciprofloxacin [70.4% versus 43%], tetracycline [88.9% versus 57%] and trimethoprim-sulfamethoxazole [98.1% versus 69.6%]. Sequencing of gene cassettes harbored mostly dihydrofolate reductase [dfrA], which encodes resistance to trimethoprim and aminoglycoside adenyltransferase [aadA] that encodes resistance to streptomycin. The most frequent combination types were dfrA17 and aadA5 genes. Class I integrons were quite common and its carriage contributed significantly to the emergence of MDR among E. coli. Nevertheless, factors leading to the wide spread of integrons are still to be determined

Throat culture screening for Beta-haemolytic streptococci among schoolboys in Saudi Arabia

This study was designed to estimate the carrier rate of beta-haemolytic streptococci among 972 primary-school boys in a high-altitude area of Saudi Arabia, and its association with social class, crowding index and body mass index, and also to determine the seasonal variation of infection. A carrier rate of 13.1% for beta-haemolytic streptococci was detected. The carrier rate was significantly higher in spring than in winter. The association between streptococcal infection and social class, crowding index, or body mass index was statistically not significant. The low prevalence of streptococcal infection might be attributed to the high altitude but further studies are needed to determine whether this is the case