title: Molecular characterization of Staphylococcus aureus isolates from various healthcare institutions in Nairobi, Kenya: a cross sectional study.
abstract: BACKGROUND
  Staphylococcus aureus (S. aureus) has established itself over the years as a major cause of morbidity and mortality both within the community and in healthcare settings. Methicillin resistant S. aureus (MRSA) in particular has been a major cause of nosocomial infections resulting in significant increase in healthcare costs. In Africa, the MRSA prevalence has been shown to vary across different countries. In order to better understand the epidemiology of MRSA in a setting, it is important to define its population structure using molecular tools as different clones have been found to predominate in certain geographical locations.
  
  
  METHODS
  We carried out PFGE, MLST, SCCmec and spa typing of selected S. aureus isolates from a private and public referral hospital in Nairobi, Kenya.
  
  
  RESULTS
  A total of 93 S. aureus isolates were grouped into 19 PFGE clonal complexes (A-S) and 12 singletons. From these, 55 (32 MRSA and 23 MSSA) representative isolates from each PFGE clonal complex and all singletons were spa typed. There were 18 different MRSA spa types and 22 MSSA spa types. The predominant MRSA spa type was t037 comprising 40.6 % (13/32) of all MRSA. In contrast, the MSSA were quite heterogeneous, only 2 out of 23 MSSA shared the same spa type. Two new MRSA spa types (t13149 and t13150) and 3 new MSSA spa types (t13182, t13193 and t13194) were identified. The predominant clonal complex was CC 5 which included multi-locus sequence types 1, 8 and 241.
  
  
  CONCLUSIONS
  In contrast to previous studies published from Kenya, there's marked genetic diversity amongst clinical MRSA isolates in Nairobi including the presence of well-known epidemic MRSA clones. Given that these clones are resident within our referral hospitals, adherence to strict infection control measures needs to be ensured to reduce morbidity and mortality associated with hospital acquired MRSA infections.
authors.affiliation: Department of Pathology, Aga Khan University Hospital Nairobi, P.O. Box 30270-00100, Nairobi, Kenya. g_omuse@yahoo.com.
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Omuse
authors.affiliation: Division of Medical Microbiology, Department of Pathology, Stellenbosch University, P. O. Box 19063, Western Cape, South Africa.
authors.forename: Kristien Nel
authors.initials: KN
authors.lastname: Van Zyl
authors.affiliation: Division of Medical Microbiology, Department of Pathology, Stellenbosch University, P. O. Box 19063, Western Cape, South Africa.
authors.forename: Kim
authors.initials: K
authors.lastname: Hoek
authors.affiliation: Division of Medical Microbiology, Department of Pathology, Faculty of Health Sciences, University of Cape Town, South Africa, P.O. Box 7925, Cape Town, South Africa.
authors.forename: Shima
authors.initials: S
authors.lastname: Abdulgader
authors.affiliation: Center of Microbiology Research, Kenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya.
authors.forename: Samuel
authors.initials: S
authors.lastname: Kariuki
authors.affiliation: Division of Medical Microbiology, Department of Pathology, Stellenbosch University, P. O. Box 19063, Western Cape, South Africa.
authors.forename: Andrew
authors.initials: A
authors.lastname: Whitelaw
authors.affiliation: Department of Pathology, Aga Khan University Hospital Nairobi, P.O. Box 30270-00100, Nairobi, Kenya.
authors.forename: Gunturu
authors.initials: G
authors.lastname: Revathi
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002999:Clone Cells; D003428:Cross Infection / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission; D003430:Cross-Sectional Studies; D004269:DNA, Bacterial / Q000235:genetics*; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D005838:Genotype; D016304:Hospitals, Private; D006779:Hospitals, Public; D006801:Humans; D007630:Kenya / Q000453:epidemiology; D055624:Methicillin-Resistant Staphylococcus aureus / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D058885:Multilocus Sequence Typing; D010802:Phylogeny; D015995:Prevalence; D013203:Staphylococcal Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology / Q000635:transmission
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial
keywords: Kenya; MRSA; MSSA; Staphylococcus aureus