Prevalence of Virulence Determinants in Staphylococcus Epidermidis from ICU Patients in Kampala; Uganda

Introduction: 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. Methodology: 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

Human immunodeficiency virus seropositivity in children aged six to eighty-four months at Kenyatta National Hospital

To determine the prevalence of the HIV seropositivity in general paediatric emergency admissions at Kenyatta National Hospital; 552 children were studied systematically for four months in 1991.A clinical history was taken and physical examination conducted. The HIV status was determined by use of organ Teknika's Vironostika viral lysate assay for initial two screenings and then a Behring enzygnost anti-HIV-1 synthetic peptide assays a confirmatory assay.Seventy (12.7) of all the children studied were HIV positive; the mean age of the HIV-positive children was 17.5 months while that of the total study population was 23.5 months. HIV seropositivity was not associated with history or parenteral injections. No haemophilia patient was recruited during the study period; and of all the 18 sicklers recruited; none was HIV positive despite multiple blood transfusions. The WHO paediatric Aids Case definition criteria had moderately low sensitivity (55.7); high specificity (85.9) and low positive predictive value (36.4). This was in agreement with observations noted in other studies in East and Central Africa