Phenotypic and genotypic characterization of methicillin resistant Staphylococcus aureus associated with pyogenic infections

Sharanya Krishnakumar; Abdul Azeez  Mohamed Khalid; Jothipandian Sowndarya; Lakshmi Krishnasamy; Paramasivam Nithyanand

doi:10.18502/ijm.v16i4.16302

Sharanya Krishnakumar Department of Microbiology, Sree Balaji Medical College and Hospital, Bharath Institute of Higher Education and Research, Chennai, Tamilnadu, India
Abdul Azeez Mohamed Khalid Biofilm Biology Laboratory, Centre for Research on Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed University, Tirumalaisamudram, Thanjavur, Tamil Nadu, India
Jothipandian Sowndarya Biofilm Biology Laboratory, Centre for Research on Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed University, Tirumalaisamudram, Thanjavur, Tamil Nadu, India
Lakshmi Krishnasamy Department of Microbiology, Sree Balaji Medical College and Hospital, Bharath Institute of Higher Education and Research, Chennai, Tamilnadu, India
Paramasivam Nithyanand Biofilm Biology Laboratory, Centre for Research on Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed University, Tirumalaisamudram, Thanjavur, Tamil Nadu, India

DOI: https://doi.org/10.18502/ijm.v16i4.16302

Keywords: Staphylococcus aureus; Pyogenic infection; Methicillin-resistant Staphylococcus aureus; Biofilm; Multi drug resistance; Penicillin binding proteins; Healthcare associated infections

Abstract

Background and Objectives: Staphylococcal infections are one of the major infectious diseases affecting globally in spite of advances in development of antimicrobial agents. Knowledge and awareness about the local pattern and prevalence of MRSA infections plays a key role in treatment. The aim of this study was to identify MRSA strains by phenotypic and ge- notypic methods and to analyze the antibiotic susceptibility pattern of MRSA strains from patients attending a tertiary care hospital.

Materials and Methods: This study was conducted over a period of 1 year, where 296 isolates of Staphylococcus aureus were isolated from various clinical specimens. The isolated strains were examined for antibiotic susceptibility by the modi- fied Kirby Bauer disc diffusion method. Methicillin resistance was detected by cefoxitin disk diffusion test.

Results: A total of 104 isolates were found to be MRSA and 192 were found to be MSSA. Among the 104 MRSA isolates,

10 strains that were multidrug resistant were subjected to 16S rRNA gene sequencing analysis. All the 10 strains had a 99% match with S. aureus strains that were responsible for causing some serious biofilm mediated clinical manifestations like cystic fibrosis and device mediated infections. The biofilms were quantified using crystal violet staining and their ability to produce biofilms was analyzed using scanning electron microscopy and matched with the Genbank.

Conclusion: Hence these phylogenetic analysis aid in treating the patients and combating resistance to antibiotics.