بررسي الگوي مقاومت دارويي سويه هاي آنتروكوكوس فكاليس و آنتروكوكوس فسيوم در بيمارستان هاي لبافي نژاد و شهيد چمران طي سالهاي 1382-1379

Assesmental of drug resistance pattern spicess about entrococci faecalis and faecium of two hospital in tehran

Background:Entrococci induced Nosocomail infections are quite prevalent in Tehran hospitals,which are the most important and also the most prevalent cause of urinary infections among gram positive bacteria.The goals of this study are defining the prevalence of different strains of entrococci in Tehran hospitals and their resistance against commonly used antibiotics against these bacteria. Material and Methods: 339 strains of enterococci from patients of two hospitals in Tehran (labafinejad ,shahid chamran hasp) were collected from both in out patients.all strains were defined by bacteriologic & PCR tests and their drug resistance to penicillin , ampicillin ,ciprofloxacin , nitrofurantoin , imipenem and chloramphenicol were defined using carbibaer method .besides dilutional method was performed to defined MIC of gentamycine ,streptomycin (high dose aminoglyside resistant species)and ampicillin (on Ent .faccium spp.) Results:of the 339 entrococcus spp.273 ,were of faecalis strain (77.5%) and 66 were collected as faecium strain (22.5%). The E. facalis and E.facium isolates in their resistance to ampicllim (13% versus 76.5%), penicillin (14 versus 95.13%), ciprofloxacin (57% versus 80%), nitrofurantion (17.2% versus 54%), imipenem (3.2% versus 83.3%), and chloramphenicol(4.7% versus 19.6%). All isolates of E. faeclis (n=273) were susceptible to vancomynic. Resistance to vancomycin among isolates of E. faecium (n=66) has increased from 5% in 2001 to 10.6% in 2003, though they remained susceptible to linezolid and quinopristin /dlfoprestin. The phenotype van A was detected in all vancomycin resistant isolates of E. faecium. The rate of resistance to high level dose of getamaicin (HLGR strains) was high for both species of E. faecalis (42.4%) and E. faecium (60%). Conclusion:The high prevalence of HLGR strains has hindered the use of this antibiotic in synergistic combination with glycopeptides and betalactams. Linezolid and quinopristin dalfopristin could be a potential alternative against multidrug resistant strains of enterococci including glycopeptide resistant isolates in Iran.