ABSTRACT
The aim of the study was to compare the effectiveness of Cefoxitin with that of Methicillin/Oxacillin in the determination of mecA gene in Methicillin resistant Coagulase-negative staphylococci [CoNS]. We assessed 57 CoNS isolates for mecA gene via PCR, which were subsequently subjected to Methicillin/Oxacillin and Cefoxitin disc diffusion test. These methods are simple, inexpensive and easily available compared to PCR despite less specificity. Out of 41 mecA positive species, 33 [80.5%] were resistant to Methicillin/Oxacillin. Cefoxitin-resistance was seen in all 41 [100%] mecA positive samples. Two [12.5%] mecA negative isolates of S.saprophyticus were Methicillin/Oxacillin resistant, but were Cefoxitin sensitive. Four [9.7%] isolates of S.saprophyticus, three [7.3%] of S.epidermidis species, and one [2.4%] S.haemolyticus that were mecA positive were sensitive to Methicillin/Oxacillin but resistant to Cefoxitin. Cefoxitin resistance provides a more accurate picture of mecA gene positivity as compared to Methicillin and Oxacillin
ABSTRACT
The aim of this study was to evaluate the antibiotic resistance pattern of Psedomonas aeruginosa and its prevalence in patients with urinary tract infections [UTI] for effective treatment in a developing country like Pakistan. This is an observational study conducted for a period of ten months which ended on December 2013 at the Dr. Essa Laboratory and Diagnostic Centre in Karachi. A total of 4668 urine samples of UTI patients were collected and standard microbiological techniques were performed to identify the organisms in urine cultures. Antibiotic susceptibility testing was performed by Kirby-Bauer technique for twenty five commonly used antimicrobials and then analyzed on SPSS version 17. P. aeruginosa was isolated in 254 cultures [5.4%]. The most resistant drugs included Ceclor [100%] and Cefizox [100%] followed by Amoxil/Ampicillin [99.6%], Ceflixime [99.6%], Doxycycline [99.6%],Cefuroxime [99.2%], Cephradine [99.2%], Cotrimoxazole [99.2%], Nalidixic acid [98.8%], Pipemidic acid [98.6%] and Augmentin [97.6%]. Emerging resistant strains of Pseudomonas aeruginosa are potentially linked to injudicious use of drugs leading to ineffective empirical therapy and in turn, appearance of even more resistant strains of the bacterium. Therefore, we recommend culture and sensitivity testing to determine the presence of P.aeruginosa prior to specific antimicrobial therapy