title: Molecular characterization of Staphylococcus aureus from patients with surgical site infections at Mulago Hospital in Kampala, Uganda.
abstract: BACKGROUND
  The prevalence of Methicillin resistant Staphylococcus aureus (MRSA) is progressively increasing globally with significant regional variation. Understanding the Staphylococcus aureus lineages is crucial in controlling nosocomial infections. Recent studies on S. aureus in Uganda have revealed an escalating burden of MRSA. However, the S. aureus genotypes circulating among patients are not known. Here, we report S. aureus lineages circulating in patients with surgical site infections (SSI) at Mulago National hospital, Kampala, Uganda.
  
  
  METHODS
  A cross-sectional study involving 314 patients with SSI at Mulago National Hospital was conducted from September 2011 to April 2012. Pus swabs from the patients' SSI were processed using standard microbiological procedures. Methicillin sensitive Staphylococcus aureus (MSSA) and MRSA were identified using phenotypic tests and confirmed by PCR-detection of the nuc and mecA genes, respectively. SCCmec genotypes were determined among MRSA isolates using multiplex PCR. Furthermore, to determine lineages, spa sequence based-genotyping was performed on all S. aureus isolates.
  
  
  RESULTS
  Of the 314 patients with SSI, S. aureus accounted for 20.4% (64/314), of which 37.5% (24/64) were MRSA. The predominant SCCmec types were type V (33.3%, 8/24) and type I (16.7%, 4/24). The predominant spa lineages were t645 (17.2%, 11/64) and t4353 (15.6%, 10/64), and these were found to be clonally circulating in all the surgical wards. On the other hand, lineages t064, t355, and t4609 were confined to the obstetrics and gynecology wards. A new spa type (t10277) was identified from MSSA isolate. On multivariate logistic regression analysis, cancer and inducible clindamycin resistance remained as independent predictors of MRSA-SSI.
  
  
  CONCLUSIONS
  SCCmec types I and V are the most prevalent MRSA mecA types from the patients' SSI. The predominant spa lineages (t645 and t4353) are clonally circulating in all the surgical wards, calling for strengthening of infection control practices at Mulago National Hospital.
authors.affiliation: Department of Medical Microbiology, Makerere University College of Health Sciences, Kampala, Uganda. senijj80@gmail.com
authors.forename: Jeremiah
authors.initials: J
authors.lastname: Seni
authors.forename: Freddie
authors.initials: F
authors.lastname: Bwanga
authors.forename: Christine F
authors.initials: CF
authors.lastname: Najjuka
authors.forename: Patson
authors.initials: P
authors.lastname: Makobore
authors.forename: Moses
authors.initials: M
authors.lastname: Okee
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Mshana
authors.forename: Benson R
authors.initials: BR
authors.lastname: Kidenya
authors.forename: Moses L
authors.initials: ML
authors.lastname: Joloba
authors.forename: David P
authors.initials: DP
authors.lastname: Kateete
mesh_terms: D000293:Adolescent; D000328:Adult; D001426:Bacterial Proteins / Q000235:genetics; D002648:Child; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology*; D003430:Cross-Sectional Studies; D052978:Disk Diffusion Antimicrobial Tests; D005260:Female; D006761:Hospitals; D006801:Humans; D008297:Male; D016106:Methicillin Resistance / Q000235:genetics; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics*; D008836:Micrococcal Nuclease / Q000235:genetics; D058885:Multilocus Sequence Typing; D015999:Multivariate Analysis; D010362:Patients' Rooms; D046915:Penicillin-Binding Proteins; D015995:Prevalence; D013203:Staphylococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D013530:Surgical Wound Infection / Q000453:epidemiology / Q000382:microbiology*; D014454:Uganda; D055815:Young Adult
chemical_list: D001426:Bacterial Proteins; D046915:Penicillin-Binding Proteins; C487789:mecA protein, Staphylococcus aureus; C074002:nuc protein, staphylococcus; D008836:Micrococcal Nuclease