Evaluation of TBc identification immunochromatographic assay for rapid identification of Mycobacterium tuberculosis complex in samples from broth cultures.

Tuberculosis (TB) is a disease of major public health concern worldwide, especially in developing countries. In addition, the human immunodeficiency virus (HIV) epidemic has increased the incidence of infection with nontuberculous mycobacteria (NTM). Rapid, accurate, and simple methods for differentiation of Mycobacterium tuberculosis complex (MTBC) isolates from NTM is greatly needed for successful control of the TB epidemic. This study was done to evaluate the clinical performance of the BD MGIT TBc identification test (TBc ID) for rapid identification of MTBC in samples from broth cultures. A total of 229 Ziehl-Neelsen (ZN) stain-positive MGIT cultures were tested using the TBc ID test, and the results were compared with those of the AccuProbe MTBC identification test (GenProbe, San Diego, CA). The agreement between the TBc ID test and the AccuProbe assay was 96% (kappa = 0.92; confidence interval [CI] = 0.869 to 0.971). The sensitivity, specificity, and negative and positive predictive values of the TBc ID test compared to the AccuProbe assay were 100%, 92.4%, 100%, and 92.2%, respectively. After additional molecular testing, the agreement between the two methods increased to 97.8% (kappa = 0.96; CI = 0.917 to 0.994), and the specificity and positive predictive value increased to 95.6% and 95.7%, respectively. The TBc ID test is a simple, sensitive, and specific test for identification of MTBC in samples from acid-fast bacillus (AFB) smear-positive cultures. The TBc ID test could be a good alternative to the AccuProbe test in TB diagnostic laboratories.

Drug-susceptibility patterns of Mycobacterium tuberculosis in Mpumalanga province, South Africa: possible guiding design of retreatment regimen.

Multidrug-resistant tuberculosis (MDR-TB) has been a cause of concern in both developed and developing countries. The prevalence of drug resistance in Mycobacterium tuberculosis (MTB) isolates (n=692) from Mpumalanga province was assessed. In total, 692 (64%) MTB strains from cases with pulmonary TB were tested for susceptibility against rifampicin, isoniazid, ethambutol, and streptomycin using the MGIT 960 instrument. Two hundred and nine (30.2%) strains were resistant to one or more drugs. Resistance to one drug ranged from 1.4% for ethambutol to 17.7% for rifampicin. The prevalence of MDR-TB ranged from 6.7% for three drugs to 34% for four drugs, with significant predictors being patients' age-groups of 25-54 years (p=0.0012) and >55 years (p=0.007). The result showed a high level (58.4%) of MDR-TB from cases in Mpumalanga province. To achieve a higher cure rate in this province, drug-susceptibility tests must be done for every case.

Risk of having a sexually transmitted infection in women presenting at a termination of pregnancy clinic in Pretoria, South Africa.

This study was undertaken to assess the risk of being infected with a known sexually transmitted pathogen at the time of presentation for termination of pregnancy. Endocervical and vaginal swabs were collected for the diagnosis of Neisseria gonorrhoeae, Chlamydia trachomatis and Trichomonas vaginalis. Single infections were found in 21.5% of the women, with C. trachomatis being the commonest (10.0%). Mixed infections were found in nine women, with trichomoniasis and chlamydial infections in six. During speculum examination, vaginal discharge was observed in 73% of the women. The commonest organism detected in patients with vaginal discharge was C. trachomatis (11.6%), while T. vaginalis (11.1%) was the most common in women without visible vaginal discharge. No significant differences were found when comparing symptomatic and non-symptomatic women. This study strongly recommends that women presenting for termination of pregnancy be screened for STIs and receive relevant sexual health education.

Use of an immunochromatographic kit for the rapid detection of Mycobacterium tuberculosis from broth cultures.

In settings of high human immunodeficiency virus (HIV) prevalence, culture confirmation, preferably by liquid culture, is required for the diagnosis of tuberculosis (TB). However, long delays with phenotypic identification offsets the short turnaround time of liquid cultures. We report here the advantages of using a commercial immunochromatographic (ICT) assay targeting the Mycobacterium tuberculosis protein 64 (MPT-64) Ag and compare it with the Accuprobe MTB complex molecular probe assay. The performance of the ICT kit was excellent, with sensitivity, specificity, positive and negative predictive values of respectively 97%, 100%, 100%, and 92%. The kit requires a 15-min assay time, is easy to perform and is a good method for simplifying the diagnosis of TB.

A retrospective review of malaria cases seen in a non-endemic area of South Africa.

BACKGROUND: Malaria is a risk for travelers to endemic areas. We describe the diagnosis and treatment of malaria in Pretoria, a non-endemic area in South Africa. METHODS: Records of specimens submitted to the medical microbiology laboratory for malaria investigations over 3 years were reviewed with follow up of hospital records for positive specimens for clinical data. The laboratory performs malaria smears and uses HRP2-Ag testing for rapid diagnosis of Plasmodium falciparum. RESULTS: A total of 516 specimens were received, with a 211/516 (41%) malaria smear positive rate. The number of malaria positive specimens has been increasing overtime and this increase was statistically significant in children [p=0.005]. HRP2-Ag testing was done on 430 specimens with124/430 (29%) being positive, of which 10/124 (8%) were smear negative, giving 98% sensitivity. Hospital records for 198/211 (94%) smear positive cases showed that 190/198 (96%) of the patients had a travel history with 170/190 (71%) having traveled to Mozambique, a malaria endemic country. Most patients presented with uncomplicated malaria; the CFR was 4/198 (2%). Treatment mainly followed South African national guidelines. CONCLUSION: Imported malaria is increasingly being diagnosed in returning travelers, especially from Mozambique. Rapid antigen tests remain useful for the diagnosis of malaria in non-endemic areas.

Increased exposure to hepatitis B virus infection in HIV-positive South African antenatal women.

The prevalence of markers for hepatitis B virus (HBV) exposure and active infection in HIV-positive (n=710) and HIV-negative (n=710) pregnant South African women was investigated. The following statistically significant increases in the HIV-positive group were found: anti-hepatitis B core antigen (anti-HBc) (37.3% versus 28.6%; odds ratio [OR]: 1.49); anti-hepatitis B surface antigen (anti-HBs) (29.5% versus 20.1%; OR: 1.66); exposure based on hepatitis B surface antigen (HBsAg) and anti-HBc (39.2% versus 30.1%; OR: 1.49); and exposure based on anti-HBs, anti-HBc and HBsAg (37.1% versus 24.5%; OR: 1.82). However, there was no increase in active HBV infections, with 2.4% of the HIV positives and 2.2% of the HIV negatives being HBV DNA positive. Although the impact that HIV has had on the prevalence of HBV in this population group is not as pronounced as that found in areas of low endemicity (where up to seven-fold increases have been reported), there is a statistically significant increased exposure to HBV.

Acceptability and feasibility of Micralax applicators and of methyl cellulose gel placebo for large-scale clinical trials of vaginal microbicides.

OBJECTIVE(S): To evaluate the feasibility and acceptability of the Micralax applicator and of methyl cellulose placebo gel for use in vaginal microbicide clinical trials. DESIGN: A two-centre prospective study following women for 2 months. SETTING: Two primary health care clinics in South Africa. PATIENTS, PARTICIPANTS: Female volunteers (n = 28) 18 years or older who were HIV negative and had no clinically detectable genital tract abnormalities or reproductive tract infections. INTERVENTIONS: Participants used pre-filled Micralax applicators to apply methyl cellulose gel every other day, as well as up to 1 h before to every episode of vaginal sex. MAIN OUTCOME MEASURE(S): Consistency in the weight of gel dispensed per application; side-effects attributed to applicator or gel use; and acceptability of the applicator and of the gel. RESULTS: Over a 2 month follow-up period the 22 women completing the study reported no adverse events related to gel or applicator use. The Micralax applicator proved acceptable. The gel was not too messy and did not reduce sexual frequency or pleasure. On average, the applicator dispensed 4.7 ml per use (close to the 4 ml planned). CONCLUSIONS: The Micralax applicator performs well as a delivery system for potential vaginal microbicides; and methyl cellulose is an appropriate placebo for future microbicide trials.

Double stranded RNA virus in South African Trichomonas vaginalis isolates.

AIMS: To screen Trichomonas vaginalis isolates from South Africa for the presence of a small double stranded RNA virus designated T vaginalis virus (TVV). METHODS: TVV was detected by simultaneous extraction of DNA and RNA, and its presence confirmed by electron microscopy and nuclease digestions. RESULTS: TVV was detected in 59 of 72 (81.9%) isolates. CONCLUSIONS: These results indicate a possible higher infection rate of South African T vaginalis isolates by the double stranded RNA virus than has been reported for isolates elsewhere.

Growth and cultural characteristics of Calymmatobacterium granulomatis--the aetiological agent of granuloma inguinale (Donovanosis).

Granuloma inguinale is a chronic destructive granulomatous disease of the genitalia. The clinical diagnosis is often unreliable and the definitive diagnosis is based on the visualisation of 'Donovan bodies' in tissue smears or biopsy specimens. The organism implicated in its aetiology, Calymmatobacterium granulomatis, was reported to have been cultured > 30 years ago, but little is known about the organism because of its fastidious nature and the difficulty in culturing it. Twenty-two biopsy specimens from female patients with clinical and laboratory-confirmed granuloma inguinale were treated with amikacin 10 mg/L and inoculated in a monocyte co-culture system with peripheral blood mononuclear cells (PBMC) from a single donor and autologous sera. The method was subsequently modified by pretreatment of specimens with vancomycin 5 mg/L and metronidazole 10 mg/L in addition to amikacin 10 mg/L for the purpose of decontamination, pooled blood donor PBMC and by the use of heat-inactivated fetal calf serum instead of autologous serum for culture. This modified method was used to culture additional biopsy specimens and genital ulcer scrapings from female and male patients, respectively. All monocyte co-cultures were examined by a rapid Giemsa (RapiDiff) stain and by an indirect immunofluorescence test with immune sera. Representative cultures were examined by transmission electron microscopy. C. granulomatis was successfully isolated in pure culture by the monocyte co-culture system from four biopsy specimens and 14 genital ulcer scrapings. The cultured organisms were visible both intra- and extra-cellularly and were extremely pleomorphic, with characteristic single and biopolar condensation. The numbers of the organisms increased after each passage. All positive cultures showed bright fluorescence when tested with immune sera. Transmission electron microscopy of the cultured bacteria demonstrated a typical gram-negative cell wall consisting of an outer membrane, middle electron opaque layer and an inner plasma membrane. The capsule was thick and electron dense. Numerous electron dense granules were present within the cytoplasm.

Phylogenetic analysis of Calymmatobacterium granulomatis based on 16S rRNA gene sequences.

Calymmatobacterium granulomatis is the aetiological agent of granuloma inguinale - a chronic granulomatous genital infection - and is morphologically similar to members of the genus Klebsiella. This study determined the 16S rRNA gene sequence of C. granulomatis and the taxonomic position of the organism in relation to the genus Klebsiella. Genomic DNA was extracted from C. granulomatis-infected monocytes and from frozen and formalin-fixed paraffin wax-embedded tissue biopsy specimens from patients with histologically proven granuloma inguinale. The 16S rDNA was amplified by PCR with broad range oligonucleotide primers. The amplified DNA fragments were cloned into pMOS vector, digested with Bam HI and Pst1 restriction endonucleases, hybridised with a gram-negative bacterial probe (DL04), sequenced in both directions by the automated ALF DNA sequencer, verified on an ABI Prism 377 automated sequencer and analysed with DNASIS and MEGA software packages. Sequence analysis revealed DNA homology of 99% in C. granulomatis from the different sources, supporting the belief that the bacteria in the culture and the biopsy specimens belonged to the same species, although there was some diversity within the species. Phylogenetically, the strains were closely related to the genera Klebsiella and Enterobacter with similarities of 95% and 94% respectively. C. granulomatis is a unique species, distinct from other related organisms belonging to the gamma subclass of Proteobacteria.

Comparison of culture media for the laboratory diagnosis of chancroid.

Seven different agar-based media were compared to determine the optimal set of culture media for primary isolation of Haemophilus ducreyi. Also, a new method for sampling genital ulcers -- with a disposable sterile plastic loop -- and processing specimens that provides a standardised inoculum for culture of H. ducreyi on various media is described. A total of 202 patients with genital ulcer disease was enrolled in this study. A sterile swab or plastic loop was used to sample the base of the ulcers and ulcer material was suspended in sterile phosphate-buffered saline. A 100-microl sample of this suspension was mixed with an equal volume of tryptic soy broth containing IsoVitaleX and centrifuged for 1 min. This suspension was used to inoculate the different media. Plates were incubated at 33 degrees C in micro-aerophilic conditions and examined for growth of H. ducreyi after 48 h. Of the 202 specimens, 77 (38.1%) were culture positive for H. ducreyi. None of the agar bases supported the growth of all H. ducreyi strains. Based on this observation, we recommend the universal use of Mueller-Hinton agar base supplemented with chocolate horse blood and IsovitaleX (MH-HBC) and Columbia agar base supplemented with bovine haemoglobin, activated charcoal, fetal calf serum and IsovitaleX (C-HgCh) to enable comparison of prevalence figures for chancroid. In addition, the novel sampling technique described in this study eliminates sampling bias normally associated with genital ulcer specimens.

Ultrastructure of Calymmatobacterium granulomatis: comparison of culture with tissue biopsy specimens.

The ultrastructural features of cells of Calymmatobacterium granulomatis from monocyte co-cultures and tissue biopsy specimens were compared. In cultures the bacteria were mainly extracellular, i.e., not within membrane-bound vacuoles. The bacterial body was surrounded by a uniformly extensive homogeneous layer with a relatively high electron density. This layer varied considerably in tissue biopsy specimens, having either homogeneously electron-dense or delicate web-like structures with varying density and thickness. In tissue specimens the bacteria were located predominantly within vacuoles of varying sizes in the cytoplasm of the macrophages and, occasionally, extracellularly within the intercellular spaces of the stroma. The bacterial cytoplasm contained ribosomes scattered throughout with electron-dense granules located peripherally. The trilaminar cell-wall structure was typical of a gram-negative organism, comprising an outer membrane, a middle electron-opaque layer and an inner plasma membrane. Surface structures such as fimbriae, flagella and bacteriophages were not identified in specimens from either source.

Pasteurella gallinarum neonatal meningitis.

A 4-day-old baby weighing 1.7 kg was admitted to the neonatal intensive care unit of Ga-Rankuwa Hospital, Pretoria, with a history of apneic attacks. On examination there was an umbilical sepsis and the neonate was septicemic. The baby had been delivered at home and the umbilical cord had been cut by the grandmother using unclean scissors and chimney soot applied to the umbilical stump. On admission, a septic screen was done and antibiotic treatment was started with penicillin and amikacin. The investigations showed that the baby was slightly anemic, with hemoglobin levels of 10.0 g/dL (14.9-23.7 g/dL), and a pure growth of a Gram-negative bacillus was obtained from the cerebrospinal fluid, blood culture and suprapubic aspirate urine specimens. The Gram-negative bacillus was catalase and oxidase positive and it was identified as Pasteurella gallinarum. Antimicrobial profiling showed the organism to be susceptible to penicillin, cefotaxime, gentamicin and amikacin. Despite having received antimicrobial agents to which the etiological agent was susceptible, the neonate died within 5 days of admission. The cause of death was postulated to be due to overwhelming sepsis which resulted in septic shock.

Utility of surveillance bacterial cultures in neonatal exchange blood transfusions.

Invasive procedures, like exchange blood transfusions via the umbilical vein, potentially expose the neonate to nosocomial infection. Attempts to limit hospital-acquired infection following exchange transfusions (ETF) in our unit have included umbilical vein blood cultures and swabs from umbilical stumps. The value of this surveillance was examined. Forty-four neonates undergoing ETF were studied prospectively. Specimens for bacterial cultures were taken from the umbilical stump and umbilical vein immediately before and after ETF and results correlated with clinical outcome and antibiotic use. Except for staphylococci, bacteria cultured in the asymptomatic neonates were similar to those cultured from neonates who had signs of infection. Polymicrobial cultures were obtained from both umbilical vein blood and stump specimens suggesting contamination with colonizing organisms. Surveillance bacterial culture results did not influence antimicrobial therapy. Therefore, we advocate microbiological investigations only when clinical infection is suspected.

Neonatal group B streptococcal infections in Indian (Asian) babies in South Africa.

In this, the first report of group B streptococcal (GBS) infections in Asian neonates in South Africa, the incidence was 2.65/1000 live births over a period of 3.5 years. Early onset disease (EOD), defined as arising less than or equal to 5 days after birth, was present in 79% cases; in most of these, the onset was before the age of 24 h. One baby presented with two episodes of late onset GBS infection. The incidence of culture-proven neonatal septicaemia during the same period was 12.3/1000 live births, GBS being commonest organism isolated. It was also the most frequent cause of bacterial meningitis in the newborn, accounting for 89% cases. Although neurological signs were present in 40% patients with EOD, only 13.3% had CSF-culture-positive meningitis. Radiographic features of hyaline membrane disease were found in half of the babies with EOD and for whom a chest radiograph was performed, while one had a pneumothorax. The overall mortality was 13.2% which is much lower than that reported in other series.

HIV infection and asymptomatic sexually transmitted infections in a rural South African community.

The objective was to determine the prevalence of HIV and other sexually transmitted infections (STIs) in a rural community. A population-based survey of adults in 110 homesteads was conducted in 1995. A questionnaire on demographics, sexual practices and history of STDs was administered. Neisseria gonorrhoeae and Chlamydia trachomatis infections were detected using ligase chain reaction (LCR) assay of urine. The seroprevalence of syphilis rapid plasma reagin (RPR) and Treponema pallidum haemagglutination assay (TPHA) and HIV infection (ELISA) was determined. Among 259 subjects the prevalence of HIV was 10.5%, N. gonorrhoeae 4.5%, C. trachomatis 6.1% and active syphilis 8.8%. All infections were asymptomatic. Forty per cent of sexually active men had more than one concurrent sexual partner. Only 14% of subjects had ever used condoms. The STI epidemic is being promoted by high levels of asymptomatic infections, high partner concurrency and low condom use.

PIP: This study determined the prevalence of HIV and other sexually transmitted infections (STIs) in a rural South African community. A population-based survey of adults in 110 homesteads was conducted in 1995. A questionnaire on demographics, sexual practices and histories of STIs was administered. Neisseria gonorrhea and Chlamydia trachomatis infections were detected using ligase chain reaction assay of urine. The seroprevalence of syphilis rapid plasma reagin and Treponema pallidum hemagglutination assay and HIV infection (ELISA) was determined. Among 259 subjects, the prevalence of HIV was 10.5%; N. gonorrhea, 4.5%; C. trachomatis, 6.1%; active syphilis, 8.8%. All infections were asymptomatic. About 40% of sexually active men had more than one concurrent sexual partner. Only 14% of subjects had ever used condoms. In general, these findings indicate that high levels of asymptomatic infections, high partner concurrence, and low condom use are promoting the STI epidemic in this community.

Bacterial vaginosis and associated infections in pregnancy.

OBJECTIVE: To assess the role of bacterial vaginosis (BV) on pregnancy complications in a developing community where mixed cervico-vaginal infections are common. SETTING: The antenatal clinic at King Edward VIII Hospital (KEH), Durban, South Africa, which is a large urban tertiary hospital serving mainly a Black underprivileged population of KwaZulu/Natal. METHODS: Asymptomatic pregnant women < or = 30 weeks gestation were recruited at their first antenatal visit. Clinical data including the sexual history were recorded. Swab specimens were collected from the vagina and endocervix for diagnosing BV, trichomoniasis, candidiasis, gonorrhea and chlamydial infection. Venous blood specimens were tested for antibody to syphilis and human immunodeficiency virus (HIV). All women continued standard antenatal care and hospital records were reviewed following delivery to evaluate pregnancy outcome. RESULTS: BV was found in 52% of the women studied and was the commonest infection diagnosed. Mixed vaginal infections of BV and trichomoniasis were diagnosed in 14%. Only 29% of asymptomatic women did not have any microbiological evidence of a lower genital tract infection. A total of 46% of women studied had poor pregnancy outcome as measured by obstetrical complications, pregnancy loss and/or neonatal morbidity. There was a significant difference in outcome in women with BV (55 of 88) compared to those having infections other than BV (13 of 31), or no infection (5 of 9)-P = 0.005. This difference was for obstetrical complications of preterm delivery, premature rupture of membranes and intrauterine infection, but not for pregnancy losses and neonatal morbidity. CONCLUSIONS: The high prevalence of BV and concomitant lower genital tract infections among asymptomatic pregnant women and the resultant adverse pregnancy outcome associated with BV, confirms reports from developed countries of the need for screening for BV at the initial antenatal clinic visit. Whether pregnancy outcome was worse in the presence of BV and other infections than BV alone could not be determined. Future studies with appropriate interventions are needed to evaluate the unique problems of developing countries.

Granuloma inguinale in association with pregnancy and HIV infection.

OBJECTIVES: A retrospective study to confirm the clinical impression of an increasing prevalence of granuloma inguinale (GI) in women, and to evaluate its association with pregnancy and HIV infection. METHODS: Clinical records of all patients with a definitive diagnosis of GI attending the gynecology and antenatal clinics at King Edward VIII Hospital, Durban, South Africa, over a period of 36 months (January 1991-December 1993). RESULTS: A total of 123 women were diagnosed with GI. The diagnosis was made by tissue smear alone in 21% (n = 26), histology 43% (n = 53) and by a combination of smear and histology in the rest. Forty-two percent (n = 52) were pregnant. The only difference between pregnant and non-pregnant women were the presence of rectal and pelvic lesions in the latter. Sixty-nine percent (n = 36) delivered vaginally while the remaining (n = 16) were delivered by cesarean section. The indications for cesarean section were obstetric except for a patient in labor with extensive untreated vulval granuloma. In the majority (85%) GI had no influence on pregnancy outcome. There was no evidence of congenital GI in the neonates. Twenty-seven percent (30/113) had positive syphilis serology and 16% (18/110) had antibody to HIV. There were no differences in the clinical features and outcome of HIV positive and negative women. CONCLUSION: This study shows that GI is increasing in pregnancy in Durban, South Africa. Despite the concern that pregnancy promotes dissemination of GI, such an effect could not be established as the clinical response to treatment and outcome were similar in both pregnant and non-pregnant women. Infection with HIV also did not alter the clinical presentation and outcome of the disease in the patients studied.

Pneumocystis carinii pneumonia (PCP) at Ga-Rankuwa Hospital.

Pneumocystis carinii is recognized as one of the leading causes of death in AIDS patients in developed countries but its role in this regard in developing countries appears to be less prominent. Sub-Saharan African countries, in spite of their high HIV prevalence, have hardly recorded any cases. We report the first microbiologically proven case of PCP in an adult patient at Ga-Rankuwa Hospital. A 37 year old African woman was referred to Ga-Rankuwa Hospital from the local clinic for chest infection with a non productive cough that had not responded to conventional treatment. On admission, she was febrile, emaciated and in respiratory distress with oral thrush. Chest radiography showed diffuse bilateral infiltrations and a preliminary diagnosis of atypical pneumonia and tuberculosis was made. The patient was begun on penicillin, gentamicin, contrimoxazole and anti-tuberculosis therapy. Laboratory investigations revealed a low haemoglobin, positive HIV test (after counselling) and Pneumocystis carinii trophozoites and cytes in the bronchoalveolar larvage specimen. In spite of appropriate treatment the patient died within three days. One wonders whether the outcome for this middle aged woman with advanced HIV infection would have been different had appropriate cotrimoxazole therapy been administered at the primary health care centre. It must be noted that PCP may no longer be a rare disease in sub-Saharan countries and intensive investigations should be carried out to avoid losing patients with treatable infectious diseases.

Evaluation of the GenoType® MTBDRsl assay for susceptibility testing of second-line anti-tuberculosis drugs.

BACKGROUND: The GenoType® MTBDRsl assay is a new rapid assay for the detection of resistance to second-line anti-tuberculosis drugs. OBJECTIVE: To evaluate the MTBDRsl assay on 342 multidrug-resistant tuberculosis isolates for resistance to ofloxacin (OFX), kanamycin (KM), capreomycin (CPM) and ethambutol (EMB), to compare the results to the agar proportion method, and to test discrepant results using DNA sequencing. RESULT: The sensitivity and specificity of the MTBDRsl assay were respectively 70.3% and 97.7% for OFX, 25.0% and 98.7% for KM, 21.2% and 98.7% for CPM and 56.3% and 56.0% for EMB. DNA sequencing identified mutations that were not detected by the MTBDRsl assay. The 8/11 phenotypically OFX-resistant isolates had mutations in gyrA (2/8 had an additional mutation in the gyrB gene), 1/11 had mutations only in the gyrB gene, 6/21 phenotypically KM-resistant isolates had mutations in the rrs gene, and 7/26 and 20/26 phenotypically CPM-resistant isolates had mutations in the rrs and tlyA genes. CONCLUSION: The MTBDRsl assay showed lower sensitivity than previous studies. The assay performed favourably for OFX; however, it was less sensitive in the detection of KM/CPM resistance and demonstrated low sensitivity and specificity for EMB resistance. It is recommended that the MTBDRsl assay include additional genes to achieve better sensitivity for all the drugs tested.