frequency of extended spectrum beta lactamase and CTX M-I of Escherichia coli isolated from the urine tract infection of patients by phenotypic and PCR methods in the city of Khoy in Iran

The production of Extended Spectrum Beta Lactamases [ESBLs] by Escherichia coli is the main cause of resistance to Cephalosporins. In the past decade, CTX-M enzymes have become the most prevalent ESBLs in Europe, Canada, and Asia. In this study, the frequency of ESBL- producing E.coli and molecular detection of the CTX-M-I group was investigated. A total of 400 urine samples were collected from both hospitalized and out-patients in Khoy's hospitals between November 2009 and April 2010. Out of these samples, 188 were identified as E.coli by standard biochemical tests. The antibiotic Susceptibility tests to 10 antibiotics were performed by the-disk-agar diffusion [DAD] method. ESBL production was screened by phenotypic test that including disk diffusion agar and combined disk as recommended by the Clinical and Laboratory Standards Institute [CLSI] Screened isolates were investigated by PCR assay for detection of CTX-M-I group genes. The results show that out of 188 E.coli isolates identified, 56 [29.8%] were producing ESBls by phenotypic test. All isolates were sensitive to imipenem. Overall, 49 [87.5%] isolates were confirmed as CTX-M-I producer by PCR. The results of this study showed that about 30% of the identified E.coli were producing ESBL Therefore, we recommend to use molecular methods in such researches

[Antibacterial effects of Rosmarinus officinalis on methicillin - resistant Staphylococcus aureus isolated from patients and foods]

Methicillin-resistant Staphylcoccus aureus [MRSA] is considered a major problem in the world. This strain colonizes nose and causes increased incidence of nosocomial infections, mortality and morbidity. Rosemary [Rosmarinus officinalis] is a herbal medicine widely used all over the world. The aim of this study was to evaluate the in vitro antimicrobial activity of rosemary essence on MRSA isolated from patients and food. 200 strains of MRSA, 100 from patients and 100 from food samples, were collected and analyzed in Tehran, during the last year. 28 MRSA strains and multi drug resistant [MDR] strains were isolated. The antimicrobial activity of the rosemary essence against different isolates of the microorganism was evaluated by disk diffusion and macro broth dilution methods. MRSA isolates belonged to 25% and 60% of food and clinical samples, respectively. The results showed effective and similar antimicrobial activity of Rosmarinus officinalis on broth clinical and food samples with an inhibition zone of 20mm in diameter. The minimum inhibitory concentration [MIC] and minimum bactericidal concentration [MBC] in our study were 1.40 mg/ml and 2.81 mg/ml, respectively. Overuse of antibiotics has led to extensive bacterial resistance to antibiotics, which demonstrates the need for use of new antimicrobial agents. Considering increasing prevalence of MRSA strains and the beneficial effect of rosemary essence on these strains, this essence can be recommended for the treatment of MRSA infections