ارزيابي تست حساسيت مقداري فلوروكينولونها (سيپروفلوكساسين و افلوكساسين ) و آمينوگيلكوزيدها (جنتامسين و آميكاسين) در سويه هاي enterobacter ايجاد كننده عفونت هاي اداري در تهران

Evaluation of quantitative susceptibility testing of flouroquinolones ( ciprofloxacin and ofloxacin) and aminoglycosides (gentamicin and amikacin) against Enterobacter strains (UTIs agents ) in Tehran

Urinary tract infections (UTIs) are a significant cause of morbidity in people of all ages. Sexually active young women, elderly people and those undergoing catheterization or genitourinary instrumentation are at risk .Enterobacter species are rod-shaped bacteria which belong to family Enterobacteriaceae. They are found in the environment and in the human intestinal tract. Some species (E. cloacae and E. aerogenes) are the most pathogenic species which can cause opportunistic infections in immunocompromised patients. The urinary and respiratory tracts are the most common sites of infection with Enterobacter species, but bloodstream infection may occur on occasion. Aminoglycosides and fluoroquinolone are two groups of practical broad-spectrum antibiotics in UTIs treatment. Fluoroquinolones interfere with the enzyme DNA gyrase which is needed for synthesis of bacterial DNA, and aminoglycosides work by binding to the bacterial 3 OS ribosomal subunit (some work by binding to the 5OS subunit). They kill bacteria by inhibiting protein synthesis as they bind to the 16S rRNA and by disrupting the integrity of bacterial cell membrane. Susceptibility of clinical isolates of Enterobacter species (40 isolates from laboratories specimens in Tehran) to aminoglycosides (gentamicin and amikacin) and to fluoroquinolones (ciprofloxacin and ofloxacin) was determined by two methods: Disk Diffusion susceptibility and broth dilution. Results of two methods agreed with each other most of the time. There was variable range of MIC for each groups of antibiotic against Enterobacter species. Results of MIC as measured in broth and Disk Diffusion were generally comparable, it means every antimicrobial agent which produced a greater zone diameter had less MIC amount. At concentration of 128 jig/ml, all antibiotics inhibited 100% of strains. Average of inhibitory concentrations of four antibiotics for all strains were: ciprofloxacin 0.925 jig/ml, ofloxacin 4.1626 |ig/ml, gentamicin 7.578 l|ig/ml and amikacin 7.5375 |ig/ml. The numbers of resistant strains to ciprofloxacin were less than the others. The MBC amounts for 4 groups of antibiotics are at most 16-fold more than MIC. In general, resistant strains to four groups of antibiotics were insufficient. The surveys indicated that they are still promising antibacterial agents for treatment of Enterobacter strains.