Genotypic Characterization of Clinical Isolates of <i>Staphylococcus aureus</i> from Pakistan

• Main Authors: Saeed Khan, Bernard S. Marasa, Kidon Sung, Mohamed Nawaz
• Format: Article
• Language: English
• Published: MDPI AG 2021-07-01
• Series: Pathogens
• Subjects: methicillin resistance; virulence; genes; MLST; SCC<i>mec</i>; <i>Staphylococcus aureus</i>
• Online Access: https://www.mdpi.com/2076-0817/10/8/918

In this study, we compared pulsed-field gel electrophoretic (PFGE), multilocus sequence typing (MLST), Staphylococcal cassette chromosome <i>mec</i> (SCC<i>mec</i>), <i>spa</i> typing, and virulence gene profiles of 19 Panton–Valentine leucocidin (PVL)-positive, multidrug-, and methicillin-resistant clinical <i>Staphylococcus aureus</i> (MRSA) isolates obtained from a hospital intensive care unit in Pakistan. The isolates exhibited 10 pulsotypes, contained eight adhesin genes (<i>bbp, clfA, clfB, cna, fnbA, fnbB, map-eap,</i> and <i>spa</i>), 10 toxin genes (<i>hla, hlb, hld, hlg, pvl, sed, see, seg, seh,</i> and <i>tst</i>), and two other virulence genes (<i>cfb, v8</i>) that were commonly present in all isolates. The <i>spa</i>-typing indicated seven known <i>spa</i> types (t030, t064, t138, t314, t987, t1509, and t5414) and three novel <i>spa</i> types. MLST analysis indicated eight ST types (ST8, ST15, ST30, ST239, ST291, ST503, ST772, and ST1413). All isolates belonged to the <i>agr</i> group 1. Most of the isolates possessed SCC<i>mec</i> type III, but some isolates had it in combination with types SCC<i>mec</i> IV and V. The presence of multidrug-resistant MRSA isolates in Pakistan indicates poor hygienic conditions, overuse of antibiotics, and a lack of rational antibiotic therapy that have led to the evolution and development of hypervirulent MRSA clones. The study warrants development of a robust epidemiological screening program and adoption of effective measures to stop their spread in hospitals and the community.