Genotypic versus phenotypic methods for detection of [methicillin resistant staphylococcus aureus] MRSA isolates from Tanta University Hospital

Methicillin-resistant Staphylococcus aureus [MRSA] has emerged worldwide as a nosocomial pathogen of major importance, and the incidence of infections caused by MRSA continues to increase. Infections with MRSA are known to be associated with considerable morbidity and mortality. "Mortality was three times higher in patients with MRSA than those with MSSA infection in ICU. We aimed in this study to apply rapid and accurate detection method for identification of MRSA and prevent its spread in Tanta University Hospital. Our study was carried out on 110 different clinical specimens and we evaluate three different methods which are two phenotypic methods and one genotypic method for identification of MRSA .The genotypic method was Real time PCR for mec A gene and the phenotypic methods were oxacillin disc diffusion method using 1ug and 5ug OX and latex agglutination using PBP2a. Conventional PCR for 533bp mecA gene product was utilized as a golden standard test. Our study showed that disc diffusion method using OX1ug and 5ug yield 90.9% and 90.1 sensitivity and 94.1% and 76.5% specificity respectively while latex PBP2a and real time PCR yielded 100%sensitivity and 100% specificity. We recommendPBP2a latex agglutination test as a phenotypic method and Real time PCR as a genotypic method for rapid detection of MRSA. The use of these rapid assays should help to reduce the work load associated with MRSA surveillance programs and the spread of MRSA in clinical settings

Molecular characterization of ciprofloxacin resistant e. coli in community acquired urinary tract infection

Widespread use of ciprofloxacin in treatment of urinary tract infection [UTI] led to increased level of resistance in clinical isolates of E. coli. The aim of this study was to investigate the molecular characterization of ciprofloxacin resistant E.coli isolates from community acquired urinary tract infections.. E-coli strains were isolated from urine samples [E. coli represented 70% of isolates [21/30] and minimal inhibitory concentration [MIC] of Ciprofloxacin [CFX] of E. coli was measured [Resistant strains of E. coli had MICs of ciprofloxacin ranging from 4 to >32 mg per liter]. CFX resistant E. coli strains were subjected to PCR to amplify gyrA and parC genes of Quinolones resistance determining region of E. coli. DNA sequencing of amplified product was carried out and the molecular characterization of E. coli resistant to CFX were analysed [All resistant E. coli isolates contained Ser83+/-Leu and Asn87+/-Asp mutations in gyrA and a Ser83-+/-Ile mutation in parC; two isolates also contained a Glu84+/-Val mutation in parC.