Virulence factors and antimicrobial resistance in uropathogenic Escherichiacoli strains isolated from cystitis and pyelonephritis

Background/aim: The aim of this study was to investigate the prevalence of virulence genes as well as patterns of antibiotic resistance in cystitis and pyelonephritis uropathogenic Escherichia coli (UPEC) isolates. Materials and methods: Two hundred UPEC isolates were collected from hospitalized patients with pyelonephritis (n = 50) and cystitis (n = 150) in Shafa Hospital in Iran. Antimicrobial susceptibility and ESBL production were determined with confirmatory tests. Polymerase chain reaction assay was performed to determine the prevalence of virulence genes in UPEC strains. Results: Of a total 200 UPEC isolates, the highest and lowest resistance rates to antibiotics were for cephalexin (74%) and nitrofurantoin (9%), respectively. Of these isolates, 72 (36%) and 128 (64%) strains were ESBL-positive and ESBL-negative, respectively. The frequency of fimH, papC, and hly was 64%, 38%, and 12%, respectively. The most commonly identified virulence gene in ESBL-positive and ESBL-negative strains was fimH 46 (23%) and 86 (43%), respectively. The hlyA gene was more prevalent among patients with pyelonephritis than cystitis. Conclusion: The frequency of virulence genes was not significantly different between pyelonephritis and cystitis UPEC strains in the studied patients, but the prevalence rates of hlyA and papC genes were higher among UPEC strains isolated from inpatients compared to outpatients; hence, they could be considered as useful targets for prophylactic interventions.

Prevalence and antimicrobial susceptibility pattern of toxigenic Clostridium difficilestrains isolated in Iran

Background/aim: Clostridium difficile is a frequent cause of nosocomial infections and has become a major public health concern in developed nations. In the present study, the prevalence and antimicrobial susceptibility pattern of toxigenic C. difficile strains isolated in Iran were investigated. Materials and methods: Between June 2016 and May 2017, 2947 inpatient fecal samples were taken from symptomatic adult hospitalized patients in different units of 32 care facilities in Tehran, Iran. C. difficile strains were identified by microbiological/biochemical methods. Susceptibility to 20 antimicrobials was measured by E-test method. Toxin-specific immunoassays and cytotoxicity assays were used to determine in vitro toxin production Results: Out of 2947 fecal samples, 538 (18.25%) C. difficile isolates were obtained among those with suspected CDI. In E-test method, all C. difficile isolates were susceptible to fidaxomicin, vancomycin, amoxicillin/clavulanate, and meropenem and were resistant to penicillin G. The prevalence of multidrug resistant C. difficile was 69.33% (373/538). Among 538 C. difficile, 147 (27.32%), 169 (31.41%), and 222 (41.26%) isolates were TcdA+/TcdB+, TcdA-/TcdB+, and TcdA-/TcdB-, respectively Conclusion: The results evidently support the hypothesis of a probable role of toxigenic strains of C. difficile in developing gastrointestinal complaints in patients with diarrhea

Extraction and purification of the H9N2 virus nucleoprotein: A simple and practical method.

Background: Avian Influenza disease annually entails a significant economic loss to the poultry industry around the world. Influenza virus is a polymorphic virus of the orthomyxoviridae family (single-stranded RNA genome), and nucleoprotein (NP) is the structural and internal protein of the virus. The aim of the work was to purify nucleoprotein for further investigations with a simple, low-cost, fast and practical method. Methods: In this study, H9N2 influenza virus was isolated in specific pathogen-free embryonated chicken eggs by allantoically inoculating 103 to 105 egg-infective doses (EID50) for 9 to 11 days, purified by 10% (W/V) polyethylene glycol (PEG) 6000 with a sucrose gradient of 60% to 30%. The influenza virus proteins were collected and prepared as fractions by preparative electrophoresis. Finally, the purified NP was subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot procedures. Results: The protein analysis with SDS-PAGE and silver nitrate staining indicated that the desired samples contained purified nucleoprotein and lacked other viral proteins. The results of the investigation of lyophilized fractions containing nucleoprotein on the SDS-PAGE revealed the absence of viral RNA in nucleoprotein and its high purity. Conclusion: According to this study, purified nucleoprotein can be used to produce nucleoprotein vaccines, as well as to study structural, molecular and diagnostic and therapeutic materials.