Antimicrobial susceptibility testing for escherichia coli strains to fluoroquinolones, in urinary tract infections

Urinary Tract Infections [UTIs] are one of the most common infectious diseases diagnosed all over the world. Meanwhile most episode of UTIs are caused by Escherichia coli [up to 85%] and frequently fluoroquinolones are preferred as initial agents for empiric therapy of UTIs. Widespread use of fluoroquinolones has resulted in an increasing incidence of resistance these agents all over the world. The aim of this study was to assess, susceptibility of Escherichia coli strains from UTI patients against common fluoroquinolones. Antimicrobial susceptibility testing was determined by disk agar diffusion [DAD] and Minimal Inhibitory Concentration methods as described by the National Committee for Clinical Laboratory Standards [NCCLS]. One hundred sixty four clinical isolates of E. coli were collected by urine cultures from patients with UTI. The extent of resistant to nalidixic acid, ofloxacin, norfloxacin and ciprofloxacin, by disk diffusion method was 49.3%, 44.5%, 41.4% and 40.2%, respectively. Resistance to ciprofloxacin by MIC method was 4.9%. This study represents high level resistant of E. coli isolates from UTI patients. It is because of inappropriate and incorrect administration of antimicrobial agents in blind cases. This problem remarks significance of performing antimicrobial susceptibility testing before empiric antibiotic therapy. To overcome this problem use of unnecessary antibiotics therapy should be limited

Detection of haemophilus influenzae type b in cerebrospinal fluid of suspected children with meningitis byPCR

A polymerase chain reaction [PCR] assay with primers from "hpd" gene was compared with culture for the detection of Haemophilus influenza type b [Hib] in CSF samples from children suspected of meningitis.300 cerebrospinal fluid [CSF] samples from suspected meningitis cases were studied by culture [Leventhal and Chocolate Agar] and PCR.The latter method could detect Hib in all 5 culture positive and in 2 of 295 culture negative cases, showing sensitivity, specificity, and an accuracy index of 100%, 99% and 99%, respectively. The PCR result was available within a day.This study has shown that PCR is a rapid, sensitive, and specific diagnostic test for Hib from CSF samples. Furthermore, to maximize management of meningitis cases to reduce the morbidity, mortality, and complications of invasive Hib infection a combination of culture and PCR is necessary for the detection of Hib infection. The incidence of Hib meningitis among children in Children's Medical Center in Tehran based on culture and PCR results were 2.4% and 1.7% respectively. Based on culture results, Hib causes 15.6% of all cases of bacterial meningitis in children