Title of article :
Antibiotic Susceptibility Pattern of Gram-positive Cocci Cultured from Patients in Three University Hospitals in Tehran, Iran during 2001-2005
Author/Authors :
Aligholi, Marzieh Department of Microbiology - School of Medicine - Tehran University of Medical Sciences , Emaneini, Mohammad Department of Microbiology - School of Medicine - Tehran University of Medical Sciences , Jabalameli, Fereshteh Department of Microbiology - School of Medicine - Tehran University of Medical Sciences , Shahsavan, Shadi Department of Microbiology - School of Medicine - Tehran University of Medical Sciences , Abdolmaleki, Zohreh Department of Veterinary Pharmacology - Faculty of Veterinary Medicine - University of Tehran , Sedaghat, Hossein Department of Microbiology - School of Medicine - Tehran University of Medical Sciences , Jonaidi, Nematollah Health Research Center - Baqiyatallah University of Medical Science, Tehran
Abstract :
Bacterial resistance to antibiotics is a serious problem and is increasing in prevalence world-wide
at an alarming rate. The antimicrobial susceptibility patterns of 1897 gram-positive bacterial Isolates were
evaluated. The minimum inhibitory concentration (MIC) of isolates which comprised Staphylococcus aureus
(927 isolates), coagulase-negative staphylococci (CNS; 425 isolates), Enterococcus faecalis (320 isolates),
Enterococcus faecium (157 isolates), and pneumococci (50 isolates) collected from 3 teaching hospitals in
Tehran were determined by agar dilution method according to Clinical and Laboratory Standards Institute
(CLSI) guidelines. The presence of mecA gene was investigated in methicillin-resistant staphylococci by PCR
method and vanA and vanB genes were targeted in enterococcal isolates by Multiplex PCR method. The resistance
rate to methicillin among S. aureus and CNS isolates were 33% and 49%, respectively. All S. aureus
isolates were susceptible to vancomycin .The lowest rate of resistance in all S. aureus isolates was found for
rifampicin (<4%). The vancomycin resistance rate in enterococci isolates was 11% which was more frequent
among E. faecium (19%) than E. faecalis (4%), all resistant isolates carrying vanA. High-level resistance to
gentamicin and streptomycin, were detected in 47% and 87% of enterococcal isolates respectively. The rate
of penicillin resistance in pneumococci was 3% and about 27% of isolates had reduced susceptibility to penicillin.
The prevalence of erythromycin resistant among pneumococci was 58%. All pneumococcal isolates
were susceptible to ceftriaxone, rifampicin and vancomycin. Our data highlight the importance of access to
updated bacterial susceptibility data regarding commonly prescribed agents for clinicians in Iran.
Keywords :
Antimicrobial susceptibility patterns , gram-positive Cocci , MRSA , VRE , Pneumococci
Journal title :
Astroparticle Physics