ABSTRACT
SETTING: An out-patient clinic in a country with high rates of tuberculosis-human immunodeficiency virus (TB-HIV) co-infection. DESIGN: Cross-sectional analytical study of 123 adults with chronic cough and no previous anti-tuberculosis treatment. Demographic, clinical, chest X-ray (CXR) and GeneXpert® MTB/RIF data were collected. Proportions of TB diagnoses using both tests were calculated and compared using an unpaired t-test. RESULTS: Sixty-six patients (53.7%) were female and 35 (28.5%) tested positive for HIV; 21 (17.1%) were Xpert-positive, while 51 (42.5%) had CXR suggestive of TB (P = 0.0018), of whom only 15 (29.4%) were Xpert-positive. CXR was suggestive of pulmonary TB in 15 (71.4%) of the 21 patients with a positive Xpert test. CONCLUSIONS: The majority of the sputum smear-negative patients did not have TB on single Xpert testing. CXR gave an overestimate of sputum smear-negative TB cases.
Subject(s)
Mycobacterium tuberculosis/isolation & purification , Radiography, Thoracic , Sputum/microbiology , Tuberculosis, Pulmonary/diagnosis , Adult , Aged , Ambulatory Care , Antitubercular Agents/therapeutic use , Bacterial Proteins/genetics , Coinfection , Cross-Sectional Studies , DNA, Bacterial/isolation & purification , DNA-Directed RNA Polymerases , Drug Resistance, Bacterial/genetics , False Positive Reactions , Female , HIV Infections/diagnosis , HIV Infections/epidemiology , Humans , Male , Middle Aged , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/genetics , Predictive Value of Tests , Prevalence , Rifampin/therapeutic use , Tuberculosis, Pulmonary/diagnostic imaging , Tuberculosis, Pulmonary/drug therapy , Tuberculosis, Pulmonary/epidemiology , Tuberculosis, Pulmonary/microbiology , Uganda/epidemiology , Young AdultABSTRACT
SETTINGS: National Tuberculosis (TB) Reference Laboratory and Department of Medical Microbiology, College of Health Sciences, Makerere University, Kampala, Uganda. OBJECTIVE: To evaluate head-to-head rapid tests for drug susceptibility testing (DST) of Mycobacterium tuberculosis against rifampicin (RMP) and isoniazid (INH) in a resource-limited setting. METHODS: Thirty-one well-characterised strains of M. tuberculosis were tested with the nitrate reductase assay (NRA), microscopic observation drug susceptibility (MODS), MGIT 960 (Mycobacterium Growth Indicator Tube 960), Genotype MTBDRplus, Alamar blue, MTT and resazurin assays. The proportion method on Löwenstein-Jensen medium was used as the reference test. RESULTS: NRA correctly identified the resistant strains, with 100% sensitivity and specificity. MGIT 960 detected all multidrug-resistant strains but missed one RMP-monoresistant strain. Genotype MTBDRplus detected all RMP-resistant strains, but the sensitivity for detection of INH resistance was lower (88%). Sensitivity and specificity ranged from 86% to 100% for MODS and from 57% to 100% for the Alamar blue, MTT and resazurin assays. Test results were obtained within 2-14 days. CONCLUSION: In the study setting, NRA, MGIT 960 and Genotype MTBDRplus gave excellent detection of multidrug-resistant tuberculosis, with significantly shorter time to results compared to conventional testing.
Subject(s)
Antitubercular Agents/pharmacology , Mycobacterium tuberculosis/drug effects , Tuberculosis, Multidrug-Resistant/diagnosis , Humans , Isoniazid/pharmacology , Microbial Sensitivity Tests , Mycobacterium tuberculosis/isolation & purification , Rifampin/pharmacology , Sensitivity and Specificity , Time Factors , Tuberculosis, Multidrug-Resistant/drug therapy , Tuberculosis, Multidrug-Resistant/microbiology , UgandaABSTRACT
Methicilline resistant Staphylococcus aureus (MRSA) strains are becoming increasingly multiresistant, and have recently developed resistance to vancomycin, which has been used successfully to treat MRSA for many years. In-vitro determination of resistance patterns of S. aureus is critical in terms of administering suitable antimicrobial treatments. The objective of this study was to determine the relative prevalence of MRSA among S. aureus isolates from surgical site infections and their antibiotic susceptibility pattern in Mulago Hospital, Kampala, Uganda. One hundred eighty eight pus swabs were collected from patients with surgical site infections. Swabs were inoculated for culture at the Microbiology Laboratory of the Faculty of Medicine, Makerere University. S. aureus isolates were identified using standard procedures and tested for oxacillin resistance according to methods of the National Committee for Clinical Laboratory Standards. Out of the 188 specimens, 54 (28.7%) grew S. aureus. Seventeen (31.5%) of the S. aureus isolates were confirmed as MRSA by PCR. Resistance rates of MRSA were 88.2% for trimethoprim-sulfamethoxazole, 88.2% for erythromycin, 58.8% for gentamycin, 70.6% for ciprofloxacin, and 88.2% for chloramphenicol. All isolates were found to be sensitive to vancomycin and clindamycin though the D-test was found to be positive in 82.4% of the isolates. In our region, although methicillin resistance increased in S. aureus strains, because of the unavailability and the high cost of alternative antibiotics, gentamycin is still suggested as an alternative for treatment of S. aureus infections. These results however indicate that vancomycin seemed to be the only antimicrobial agent effective against MRSA and it could be the drug of choice in treating multidrug resistant MRSA infection.
