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Year : 2011  |  Volume : 29  |  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

Correspondence Address:
R Moniri
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

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;29:318-319

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 Dec 11 ];29:318-319
Available from: http://www.ijmm.org/text.asp?2011/29/3/318/83926

Full Text

Dear Editor,

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. [1] Other studies reported a higher prevalence of SCCmec type II in MRSA isolates. [2] 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%. [3],[4]{Table 1}

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.[5]

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.

References

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3Machado AB, Reiter KC, Paiva RM. Distribution of staphylococcal cassette chromosome mec (SCCmec) types I, II, III and IV in coagulase-negative staphylococci from patients attending a tertiary hospital in southern Brazil. J Med Microbiol 2007;56:1328-33.
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