title: Multidrug-resistant Staphylococcus haemolyticus isolates from infected eyes and healthy conjunctivae in India.
abstract: This study aimed to determine the presence of antibiotic resistance genes (ARGs), SCCmec elements and genetic relatedness among Staphylococcus haemolyticus isolated from patients with a variety of eye infections (n=11) and from healthy conjunctiva (n=7). Minimum inhibitory concentrations were determined for 14 antimicrobials according to BSAC guidelines. PCR was used to identify the presence of mecA, mecC, SCCmec type and ARGs. Sequencing was used to determine mutations in gyrA, gyrB, topoisomerase IVA and IVB genes. Genetic relatedness was determined by PFGE. Of the 18 isolates, 17 showed resistance to at least one antibiotic, but none showed resistance to vancomycin or rifampicin. Ten isolates were oxacillin-resistant and carried the mecA gene, eight of which belonged to SCCmec type V. The presence of non-mec SCC elements in two meticillin-susceptible isolates and untypeable SCC elements in meticillin-resistant isolates suggests the involvement of S. haemolyticus in the diversification of SCC elements. Sequence analysis revealed point mutations in gyrA (Ser-84→Leu) and topoisomerase IVA genes (Ser-80→Leu) in 13 isolates, and additional variation in the QRDR (Asp-84→Asn) of two isolates, showing good correlation between mutations in gyrA and topoisomerase IV genes and the level of resistance to fluoroquinolones. PFGE analysis showed distinct pulsotypes forming two major clusters, indicating the existence of diversity among isolates, irrespective of the source of isolation. This study suggests that S. haemolyticus isolates from infected eyes and healthy conjunctivae invariably carried ARGs and SCCmec elements and showed diversity in their genomic content, irrespective of the source of isolation.
authors.affiliation: Infectious Disease Biology, Institute of Life Sciences, Nalco Square, Bhubaneswar 751023, India.
authors.forename: Sasmita
authors.initials: S
authors.lastname: Panda
authors.affiliation: Microbiological Services, L.V. Prasad Eye Institute, Patia, Bhubaneswar 751021, India.
authors.forename: Sarita
authors.initials: S
authors.lastname: Kar
authors.affiliation: Jhaveri Microbiology Centre, L.V. Prasad Eye Institute, Prof. Brien Holden Eye Research Centre, Kallam Anji Reddy Campus, L.V. Prasad Marg, Banjara Hills, Hyderabad 500034, India.
authors.forename: Savitri
authors.initials: S
authors.lastname: Sharma
authors.affiliation: Infectious Disease Biology, Institute of Life Sciences, Nalco Square, Bhubaneswar 751023, India. Electronic address: durg_singh@yahoo.co.in.
authors.forename: Durg V
authors.initials: DV
authors.lastname: Singh
mesh_terms: D000900:Anti-Bacterial Agents; D003228:Conjunctiva / Q000382:microbiology*; D024901:Drug Resistance, Multiple, Bacterial; D005123:Eye / Q000382:microbiology*; D005798:Genes, Bacterial; D006801:Humans; D007194:India; D008826:Microbial Sensitivity Tests; D013203:Staphylococcal Infections / Q000382:microbiology*; D041162:Staphylococcus haemolyticus / Q000187:drug effects* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents
keywords: Antibiotic resistance; Genetic diversity; PFGE; SCCmec typing; Staphylococcus haemolyticus