Molecular Characterisation of Methicillin-Resistant Staphylococcus aureus Isolated from Patients at a Tertiary Care Hospital in Hyderabad, South India

• Published in: Indian journal of medical microbiology Vol. 38; no. 2; pp. 183 - 192
• Main Authors: Archana, Ganapuram J., Sinha, Akhauri Yash, Annamanedi, Madhavi, Asrith, Kandala Pavan, Kale, Satyajit B., Kurkure, Nitin V., Doijad, Swapnil P., Nagamani, Kammili, Hegde, Nagendra R.
• Format: Journal Article
• Language: English
• Published: United States Elsevier B.V 01.04.2020; Wolters Kluwer India Pvt. Ltd; Elsevier Limited
• Subjects: Adult; Anti-Bacterial Agents - pharmacology; Antibiotics; Chromosomes; Clindamycin; Confidence intervals; Drug resistance; Electrophoresis; Electrophoresis, Gel, Pulsed-Field; Female; Gel electrophoresis; Genetic diversity; Humans; India; Infant, Newborn; Infectious Disease; Male; Methicillin; methicillin-resistant Staphylococcus aureus; Methicillin-Resistant Staphylococcus aureus - drug effects; Methicillin-Resistant Staphylococcus aureus - genetics; Methicillin-Resistant Staphylococcus aureus - isolation & purification; Microbial Sensitivity Tests; Middle Aged; Molecular Typing; Multi-locus sequence typing; Multilocus Sequence Typing; Population genetics; Public health; Pulsed-field gel electrophoresis; SCCmec; spa type; Spas; Staphylococcal Infections - microbiology; Staphylococcal Protein A - genetics; Staphylococcus aureus; Staphylococcus infections; Statistical analysis; Statistical methods; Tertiary Care Centers; Vancomycin; Young Adult; India; methicillin-resistant Staphylococcus aureus; pulsed-field gel electrophoresis; SCCmec; spa type; Multi-locus sequence typing
• ISSN: 0255-0857; 1998-3646
• DOI: 10.4103/ijmm.IJMM_20_151

Context: Infections with methicillin-resistant Staphylococcus aureus (MRSA) greatly influence clinical outcome. Molecular characterisation of MRSA can help to predict their spread and to institute treatment and hospital protocols. Aim: The aim of this study is to understand the diversity of MRSA in a tertiary care hospital in Hyderabad, India. Settings and Design: Samples collected at Gandhi Medical College, Hyderabad, and designed to assess hospital-or community-associated MRSA (HA-MRSA or CA-MRSA). Subjects and Methods: MRSA were subjected to antibiotic susceptibility testing, pulsed-field gel electrophoresis (PFGE), spa typing, multi-locus sequence typing and staphylococcal cassette chromosome–mec (SCCmec) typing. Statistical Analysis Used: Discriminatory index and 95% confidence interval. Results: Of the 30 MRSA, (a) 18 and 12 were HA-MRSA and CA-MRSA, respectively, and (b) 23.3% and 6.6% displayed induced clindamycin and intermediate vancomycin resistance, respectively. Genetic diversity was evident from the presence of (a) 20 pulsotypes, (b) eight spa types, with the predominance of t064 (n = 9) and (c) seven sequence types (ST), with the preponderance of ST22 and ST8 (9 each). ST22 and ST8 were the most prevalent among HA-MRSA and CA-MRSA, respectively. SCCmec type IV was the most frequent (n = 8). 44.4% of HA-MRSA belonged to SCCmec IV and V, whereas 33.3% of CA-MRSA belonged to SCCmec I and III; 33.3% (5/15) of the isolates harbouring the pvl gene belonged to SCCmec IVC/H. Conclusions: ST8 was a dominant type along with other previously reported types ST22, ST239, and ST772 from India. The observations highlight the prevalence of genetically diverse clonal populations of MRSA, suggesting potential multiple origins.