Factors associated with community-acquired urinary tract infections among adults attending assessment centre, Mulago Hospital Uganda.

BACKGROUND: Urinary tract infections (UTI) are a common medical problem affecting the general population and thus commonly encountered in medical practice, with the global burden of UTIs at about 150 million people. Because uropathogens largely originate from colonic flora, they are easy to predict, and this is the rationale for empirical treatment in Community Acquired-UTI (CA-UTIs). With the increasing prevalence of drug-resistant bacteria among adults with CA-UTI in Uganda, it is no longer adequate to manage CA-UTIs on empiric regimen without revising the susceptibility patterns of common CA-UTI causative agents. Thus in this study we set out to identify: The factors associated with CA-UTIs, the common uropathogens and the drug sensitivity patterns of the common uropathogens cultured. METHODOLOGY: This was a cross-sectional study that was conducted in adults who presented with symptoms of a UTI at Mulago Hospital, assessment center. There were 139 patients who consented to the study and were recruited, an interviewer administered questionnaire was used to collect information from the study participants as regards demographic, social and clinical characteristics and Mid Stream Urine (MSU) samples were collected for urinalysis, culture and antibiotic susceptibility testing using the Kirby-Bauer disc diffusion technique was applied to the isolates.Numeric data were summarized using measures of central tendency while the categorical data was summarized using proportions and percentages. RESULTS: Age, female sex and marital status were factors that were significantly associated with CA-UTIs. Fifty four (54) cultures were positive for UTI with 26 giving pure growths. The commonest uropathogen isolated was Escherichia coli at 50%, this was followed by Staphylococcus aureus at 15.4%. The sensitivity of Escherichia coli to Ampicillin and Nitrofurantoin were78.6%, 64.3% respectively, and the sensitivity of Staphylococcus aureus to ciprofloxacin, Nitrofurantoin and gentamycin were 100%, 66.7% and 66.7% respectively. CONCLUSION: There are known factors associated with CA-UTIs such as age, female sex. There was generally high sensitivity to nitrofurantoin and gentamycin by most of the uropathogens isolated, and high resistance to the common antibiotics such as nalidixic acid and erythromycin thus a need for a bigger study that can be used to effect the change of the current recommendations in the Uganda Clinical Guidelines as regards empirical management of CA-UTIs.

High prevalence of methicillin resistant Staphylococcus aureus in the surgical units of Mulago hospital in Kampala, Uganda.

BACKGROUND: There is limited data on Methicillin resistant Staphylococcus aureus (MRSA) in Uganda where, as in most low income countries, the routine use of chromogenic agar for MRSA detection is not affordable. We aimed to determine MRSA prevalence among patients, healthcare workers (HCW) and the environment in the burns units at Mulago hospital, and compare the performance of CHROMagar with oxacillin for detection of MRSA. RESULTS: One hundred samples (from 25 patients; 36 HCW; and 39 from the environment, one sample per person/item) were cultured for the isolation of Staphylococcus aureus. Forty one S. aureus isolates were recovered from 13 patients, 13 HCW and 15 from the environment, all of which were oxacillin resistant and mecA/femA/nuc-positive. MRSA prevalence was 46% (41/89) among patients, HCW and the environment, and 100% (41/41) among the isolates. For CHROMagar, MRSA prevalence was 29% (26/89) among patients, HCW and the environment, and 63% (26/41) among the isolates. There was high prevalence of multidrug resistant isolates, which concomitantly possessed virulence and antimicrobial resistance determinants, notably biofilms, hemolysins, toxin and ica genes. One isolate positive for all determinants possessed the bhp homologue which encodes the biofilm associated protein (BAP), a rare finding in human isolates. SCCmec type I was the most common at 54% prevalence (22/41), followed by SCCmec type V (15%, 6/41) and SCCmec type IV (7%, 3/41). SCCmec types II and III were not detected and 10 isolates (24%) were non-typeable. CONCLUSIONS: Hyper-virulent methicillin resistant Staphylococcus aureus is prevalent in the burns unit of Mulago hospital.

Identification of Staphylococcus aureus: DNase and Mannitol salt agar improve the efficiency of the tube coagulase test.

BACKGROUND: The ideal identification of Staphylococcus aureus clinical isolates requires a battery of tests and this is costly in resource limited settings. In many developing countries, the tube coagulase test is usually confirmatory for S. aureus and is routinely done using either human or sheep plasma. This study evaluated Mannitol salt agar and the deoxyribonuclease (DNase) test for improving the efficiency of the tube coagulase test in resource limited settings. The efficiency of human and sheep plasma with tube coagulase tests was also evaluated. METHODS: One hundred and eighty Gram positive, Catalase positive cocci occurring in pairs, short chains or clusters were subjected to growth on Mannitol salt agar, deoxyribonuclease and tube coagulase tests. Of these, isolates that were positive for at least two of the three tests (n = 60) were used to evaluate the performance of the tube coagulase test for identification of S. aureus, using PCR-amplification of the nuc gene as a gold standard. RESULTS: Human plasma was more sensitive than sheep plasma for the tube coagulase test (sensitivity of 91% vs. 81% respectively), but both plasmas had very low specificity (11% and 7% respectively). The sensitivity and specificity of the tube coagulase test (human plasma) was markedly improved when Mannitol salt agar and DNase were introduced as a tri-combination test for routine identification of Staphylococcus aureus (100% specificity and 75% sensitivity). The specificity and sensitivity of Mannitol salt agar/DNase/tube coagulase (sheep plasma) combination was 100% and 67%, respectively. CONCLUSION: The efficiency of the tube coagulase test can be markedly improved by sequel testing of the isolates with Mannitol salt agar, DNase and Tube coagulase. There is no single phenotypic test (including tube coagulase) that can guarantee reliable results in the identification of Staphylococcus aureus.