
The Prevalence and the Risk Factors Which
are Associated with Staphylococcus aureus
and Methicillin-Resistant S. aureus Which
Harboured the Panton-Valentine-
Leukocidin Gene in Sikkim
393-399
Correspondence
Ms. Kunsang Ongmoo Bhutia,
Department of Microbiology,
Sikkim Manipal Institute of Medical Sciences,
5th Mile Tadong, East Sikkim-737102
Phone: 9932010640
E-mail: ankusang@gmail.com
Background: The clinical sequelae of PVL-positive S. aureus infection tend to be more severe than those of the PVL-negative ones. The strong association of the PVL toxin in the MRSA isolates suggests the methcillin-resistance which contributes to the success of these PVL-positive isolates.
Aims: To estimate the burden and the risk factors which were associated with S. aureus and MRSA which harboured the pvl gene in Sikkim.
Settings and Design: A point prevalence study was conducted during a period of one year from August 2010 to 2011 in the teaching hospitals.
Materials and Methods: A total of 119 clinical strains of S. aureus were subjected to monoplex (fem-A) and multiplex PCR (mec-A and pvl) respectively.
Statistical Analysis: The data were analyzed by using Pearson’s Chi-square test. The p-value of <0.05 was taken as statistically significant.
Results: Out of 119 isolates of S. aureus, 117 (98.31%), 49 (41.17%) and 54 (45.37%) isolates were positive for the fem-A (internal control), mec-A and the pvl genes respectively. Out of the 117 fem-A positive isolates, 47 (40.17%) and 52 (44.44%) were found to be mec-A (MRSA) and pvl positive. Among the 54 pvl positive isolates, 47 (87.03%), 5 (9.25%) and 2 (3.7%) were reported from the MRSA (fem-A and mec-A positive), MSSA (fem-A positive and mec-A negative), and the MRCoNS (fem-A negative and mec-A positive) isolates respectively. The PVL toxin was significantly higher in the MRSA (87.03%), as compared to the MSSA (9.25%). Among the risk factors which were studied, patients with a previous history of antibiotic intake and hospitalization and who attended the surgery and the burn/ICU units were more positive for the MRSA and the PVLS. aureus infections as compared to the negative patients.
Conclusion: The high prevalence of the PVL toxin among the S. aureus population, which was mainly reported from the MRSA isolates, irrespective of their types i.e. CA or HA-MRSA, revealed that PVL was not a reliable marker for the CA-MRSA strains. Rather, it may be hypothesized that the MRSA strains may be important reservoirs of the PVL toxin and that it may be slowly acquired by the MSSA strains.