FREQUENCY OF ISOLATION AND ANTIMICROBIAL RESISTANCE PATTERN OF GRAM-POSITIVE BACTERIA ISOLATED FROM PATIENTS REFERRED TO PRIVATE DIAGNOSTIC MEDICAL LABORATORIES IN FARS, SOUTHWEST IRAN

Background and Aim:Private laboratories play an important role as specialized units in diagnosis of many diseases including bacterial infections. Although, the prevalence and antimicrobial resistance of Gram-positive bacteria isolated from nosocomial origins are frequently reported in many studies but there is no data available regarding the prevalence and antimicrobial resistance of Gram-positive bacteria isolated from patients referred to private diagnostic medical laboratories in Fars, Southwest of Iran.Methods:In a cross-sectional study during a one year period from February 2015, microbiological data of all biological samples of patients referred to five different private diagnostic medical laboratories in Shiraz in favor of gram-positive bacteria were analyzed retrospectively. In all included laboratories, protocols of identification of Gram-positive bacteria and antimicrobial susceptibility testing by Kirby–Bauer disc diffusion method were checked to assure that reported data are within the standard values.Results:The most common isolated Gram-positive bacteria from 74 urine, 40 wound, 6 sputum, 5 discharge and 4 throat positive culture samples were Enterococcus spp. (67%), Staphylococcus aureus (40%), S. aureus (100%), S. aureus (75%) and S. aureus (80%), respectively. All Enterococcus spp. isolates were resistant to nalidixic-acid and trimethoprim-sulfamethoxazole and 96% of them were resistant to Cephalexin, Amikacin, Ciprofloxacin and Norfloxacin. Furthermore, 50% of all identified S. aureus isolates were resistant to Erythromycin as well.Conclusion:These results inform the physicians which antibiotics are not to be prescribed to the patients; however, due to high sensitivity rate of Enterococcus spp. and S. aureus to Vancomycin, it can be remained as the first line treatment of related infections.

کلیدواژه ها:

Gram- positive bacteria ، Antimicrobial resistance ، private diagnostic medical laboratories