|Year : 2011 | Volume
| Issue : 3 | Page : 318-319
Antibiotic resistance and molecular subtypes of clinical methicillin-resistant Staphylococcus aureus in a teaching hospital
E Zeinali, R Moniri, GH Musavi
Departments of Microbiology and Immunology, School of Medicine, Kashan University of Medical Sciences, Kashan; Department of Biostatic, School of Health, Kashan University of Medical Sciences, Kashan, Iran
|Date of Submission||14-Mar-2011|
|Date of Acceptance||13-Jun-2011|
|Date of Web Publication||17-Aug-2011|
Departments of Microbiology and Immunology, School of Medicine, Kashan University of Medical Sciences, Kashan; Department of Biostatic, School of Health, Kashan University of Medical Sciences, Kashan
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Zeinali E, Moniri R, Musavi G H. Antibiotic resistance and molecular subtypes of clinical methicillin-resistant Staphylococcus aureus in a teaching hospital. Indian J Med Microbiol 2011;29:318-9
|How to cite this URL:|
Zeinali E, Moniri R, Musavi G H. Antibiotic resistance and molecular subtypes of clinical methicillin-resistant Staphylococcus aureus in a teaching hospital. Indian J Med Microbiol [serial online] 2011 [cited 2019 Jun 24];29:318-9. Available from: http://www.ijmm.org/text.asp?2011/29/3/318/83926
Emergence of multi-drug resistant methicillin resistant Staphylococcus aureus (MDR-MRSA) has profoundly affected the choice of empirical treatment for staphylococcal infection. This descriptive study was done on 87 MRSA isolates which were collected from the clinical samples of patients from a tertiary teaching hospital in Kashan, Iran, in 2010. The isolates were tested for antibiotic resistance by the disc diffusion method for 10 antimicrobials. The MRSA genotypes were determined by a multiplex polymerase chain reaction (PCR) based on the staphylococcal cassette chromosome mec (SCCmec).
All the isolates remained susceptible to vancomycin and low resistance rates were noted for amikacin (13.8%). Three (3.4%) of MRSA strains were SCCmec type I, 12 (13.8%) SCCmec type II, 8 (9.2%) SCCmec type IVb, 4 (4.6%) SCCmec type IVd and 3 (3.4%) SCCmec type V. Interestingly, there was also a high frequency of non-typeable strains 51 (58.6%) as they did not show any characteristic bands.
The resistance rates of the isolates to 10 antimicrobial agents are summarised in [Table 1]. The SCCmec type II is harboured by hospital acquired MRSA (HA-MRSA) and usually presents multi-drug resistant MRSA strains.  Other studies reported a higher prevalence of SCCmec type II in MRSA isolates.  No SCCmec type III element was detected in the MRSA isolates in this study in contrast to other reports of SCCmec type III (HA-MRSA) prevalence from 14 to 52%. ,
|Table 1: The resistance rates of the 87 MRSA isolates to 10 antimicrobial agents|
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The second most common type was SCCmec type IVb which were all sensitive to amikacin but showed high resistance rates to erythromycin, clindamycin, tetracycline and sulfamethoxazole-trimethoprim. CA-MRSA is typically characterised by the presence of SCCmec IV, V or VII which is susceptible to non-β-lactams.
In conclusion, all MRSA isolates from the teaching hospital were multi-drug-resistant, and SCCmec type II and type IV predominated. Effective hospital control practices need to be reinforced to avoid transmission of multi-drug resistant organisms.
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