Rapid and accurate detection of Methicillin Resistant Staphylococcus aureus (MRSA) is an important role of clinical microbiology laboratories to avoid treatment failure. The detection of MRSA is basedon phenotypic assays which require at least 24 h to perform. Detection of the mecA gene or of PBP 2a is the "gold standard", but not always available. The aim of this study was to evaluate a rapid method for detection of MRSA by using 3 (4, 5 dimethyl thiazole -2-yl) -2, 5 diphenyl tetrazolium bromide (MTT). Total 126 isolates of MRSA were collected from tertiary healthcare center and were confirmed by oxacillin screening agar test as per CLSI guidelines. Amplification of mecA gene was performed by using PCR. MTT assay was carried out for all the isolates in 96 well Microtitre plate and compared with standard methods of CLSI. Out of 126 isolates, 98 were found to be mecA positive. MTT method was found to be 98.98% sensitive and 96.43% specific. The MTT based colorimetric method is rapid and simple test for screening of oxacillin resistance in Staphylococcus aureus. It significantly shortens the time to just 7 h required to obtained a drug susceptibility test and could be useful to screen MRSA.Methicillin resistant Staphylococcus aureus (MRSA) strains emerged soon after the introduction of methicillin into clinical practice. MRSA is one of the major pathogen associated with serious nosocomial infection because this strain shows multiple drug resistance which limits treatment possibilities 1 . Numerous clinical studies have indicated, based on mortality rates, that MRSA strains are more virulent than methicillin-susceptible S. aureus (MSSA) strains 2 . The proportion of patients whose death is attributable to MRSA is significantly higher than that for MSSA 3 . Resistance to oxacillin is mostly mediated by the mecA gene, which codes for the production of a supplemental penicillin-binding protein, PBP2a or 2′, which is expressed either homogeneously or heterogeneously 4,5 . Expression of resistance in some MRSA strains is also regulated by homologues of the regulatory genes for blaZ that encodes for β -lactamase. These genes, mecI and mecR1, regulate the mecA response to β -lactam antibiotics in a fashion similar to that of the regulation of blaZ by the genes blaR1 and blaI upon exposure to penicillin 6 . Rosato et al. 7 have found that either mecI or blaI must be functional in all MRSA. An additional series of genes, the fem genes (factor essential for resistance to methicillin resistance), play a role in cross-linking peptidoglycan strands and also contributes to the heterogeneity of expression of methicillin resistance 8 . The typical heterogeneity seen in the expression of resistance to methicillin and in levels of resistance depends on the concerted action of chromosomally encoded genes, including fem and aux that are also present in the genome of susceptible staphylococci. Early detection of drug resistance is one of the essential steps in the management of MRSA infections and the effectiveness of a standard Anti-...

Methicillin resistant Staphylococcus aureus (MRSA) is a well recognized problem pathogen all over the world both in the nosocomial as well as in the community. Accuracy and promptness in the detection of methicillin resistance is of key importance to ensure correct doses of antibiotic treatment in infected patients as well as control of MRSAisolates in hospital environments. The present study was aimed to compare the efcacy of the susceptibility testing methods as prescribed by CLSI guidelines. Agar dilution, Disk diffusion, E test, Ezy- MIC and Hi- comb test were compared for detecting high level methicillin resistance in S aureus. The results for these phenotypic methods were compared using PCR amplication of the mecAgene as gold standard. Atotal of 106 strains of S aureus were isolated from clinical samples like blood, surgical specimens, wounds, burns and urine, from a tertiary care hospital of Central India. Out of 106 S aureus isolates 98 are mecApositive and 8 are mecAnegative. When compared with PCR for mec A, Disk diffusion- 95.91% sensitivity and 87.5% specicity, Agar dilution method- 96.93% sensitivity and 87.5% specicity, Hi-Comb test- 97.95% sensitivity and 87.5% specicity and E-test and EZY- MIC shows excellent results with 100% sensitivity, specicity, PPV and NPV. the most appropriate and accurate test giving 100% concurrence with the Gold standard was E-test and EZYMIC, with EZYMIC being much advanced in performance and reading results.

BACKGROUND: Many bacterial infections are associated with biofilm formation. It is one of the important virulent factors of E. coli in urinary tract, causing recurrent and drug resistant infections. Fecal E. coli colonize the urethra and spread up the urinary tract to the bladder and kidney. Type 1 fimbriae are surface located adhesion organelles of E. coli that are directly associated with adherence to the urinary tract. The present study was aimed to study biofilm production in E. coli isolated from urinary tract infection and to correlate it with expression of fimH gene and compare its sequences. METHOD: Total 150 urine samples were processed for isolation and identification of uropathogens. E. coli isolates were further processed for detection of biofilm by TCP method and screened for the presence of fimH gene by PCR using specific primers. The PCR products were purified and sequenced bidirectionally by Sanger dideoxy sequencing system using ABI 3500 Genetic analyzer. RESULTS: From the total 98 urine samples with significant bacteriuria, 77 E. coli were isolated out of which, 40 were positive for in vitro biofilm production. Among them11 were classified as strong biofilm producers and 29 as moderate. The fimH gene from E. coli isolates was amplified using specific primers and appeared as a band of about 508bp on agarose gel. It was noted that the fimH gene was detected in moderate and strong biofilm forming E. coli while absent in non biofilm isolates. The sequences showed 99% similarity with fim H gene of E coli. CONCLUSION: The high binding ability of fimH could result in increased bacterial binding to target cells and increased pathogenicity of E. coli.

Objective-The Extended Spectrum Beta Lactamases (ESBL) producing bacteria are increasingly causing urinary tract infection (UTI) both in hospitalized and outpatients. Failure to identify them also contributes to their uncontrolled spread. Therefore, identification of the resistant phenotypes is important, particularly in developing countries where excessive use of antibiotics and lack of adequate antimicrobial resistance surveillance is there. The present study was conducted with an objective to examine the incidence of ESBL producing stain of Klebsiella pneumoniae and E. coli from UTI. Materials and methods-A total of 200 urine samples were analyzed during the period of study. Isolates of E. coli and Klebsiella pneumoniae were selected for further study. These isolates were tested for susceptibility to antibiotics like cephotaxime, chloramphenicol, ciprofloxacin, gentamycin and amoxicillin. ESBL production was tested by double disk synergy test recommended by Clinical and Laboratory Standards Institute. Result-Out of 200 urine samples, 77 and 58 isolates were E.coli and Klebsiella pneumoniae respectively. Among these uropathogens, 45.45% of E. coli and 31 % of Klebsiella pneumoniae were ESBL positive. ESBL producing strains were also found to be resistant to other antibiotics tested. Conclusion-The investigation has demonstrated that it is important for clinical microbiology laboratories to have the ability to detect a report on ESBL production in uropathogens of Gram-negative bacteria particularly with Klebsiella pneumoniae and E.coli isolated from urinary tract infection.