title: Prevalence of virulence determinants in Staphylococcus epidermidis from ICU patients in Kampala, Uganda.
abstract: BACKGROUND
  Staphylococcus epidermidis is often considered a non-pathogenic organism but it causes nosocomial infections. To distinguish invasive strains, comparative studies of patient and community isolates may offer some clues. We investigated the distribution of virulence determinants in patient isolates from Uganda.
  
  
  METHODS
  S. epidermidis isolates were identified with the Staph API ID 32 kit. Antimicrobial susceptibility, biofilm formation and hemolysis were detected with standard procedures. Genes associated with virulence (aap, atlE, bhp, hla, hld, ica, IS256, sdrE, sea, tsst) and antimicrobial resistance (aac(6')-Ie-aph(2'')-Ia, aph(3')-IIIa, ant(4')-Ia, blaZ, mecA, vanA/vanB1) were detected by PCR.
  
  
  RESULTS
  S. epidermidis grew in 30 (30/50, 60%) ICU samples and 20 (20/60, 33%) community samples (one isolate per sample per patient/person). All ICU isolates (30/30, 100%) were IS256 and hld positive, 22 (22/30, 73%) were biofilm/ica positive, 21 (21/30, 70%) were hemolytic on blood agar, nine (9/30, 30%) contained atlE gene, six (6/30, 20%) hla gene, five (5/30, 17%) aap gene, and three (3/30, 10%) bhp gene. A gene encoding an aminoglycoside-modifying enzyme, aph(3')-IIIa, was highly prevalent (28/30, 93%), while blaZ (2/30, 7%), mecA (3/30, 10%), vanA (3/30, 10%) and vanB1 (3/30, 10%) were less prevalent. Of the community isolates, one (1/20, 5%) was ica positive, two (2/20, 10%) formed biofilms, and three (3/20, 15%) possessed the atlE gene. bhp, aap, IS256, hld and antimicrobial resistance genes were not detected in community isolates.
  
  
  CONCLUSIONS
  S. epidermidis from ICU patients in Mulago Hospital is potentially virulent and could be a reservoir for antimicrobial resistant genes.
authors.affiliation: Makerere University College of Health Sciences, Kampala, Uganda. mokee182003@yahoo.co.uk
authors.forename: Moses S
authors.initials: MS
authors.lastname: Okee
authors.forename: Moses L
authors.initials: ML
authors.lastname: Joloba
authors.forename: Margaret
authors.initials: M
authors.lastname: Okello
authors.forename: Florence Christine
authors.initials: FC
authors.lastname: Najjuka
authors.forename: Fred Ashaba
authors.initials: FA
authors.lastname: Katabazi
authors.forename: Freddie
authors.initials: F
authors.lastname: Bwanga
authors.forename: Ann
authors.initials: A
authors.lastname: Nanteza
authors.forename: David Patrick
authors.initials: DP
authors.lastname: Kateete
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D018441:Biofilms / Q000254:growth & development; D017714:Community-Acquired Infections / Q000453:epidemiology / Q000382:microbiology; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D024881:Drug Resistance, Bacterial; D005260:Female; D006461:Hemolysis; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D013203:Staphylococcal Infections / Q000453:epidemiology* / Q000382:microbiology; D013212:Staphylococcus epidermidis / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification / Q000472:pathogenicity*; D014454:Uganda / Q000453:epidemiology; D014774:Virulence / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins