Virulence genes and plasmid replicon profiles of selected ß-lactamase-producing Acinetobacter baumannii from orthopaedic patients and the environment in a tertiary referral hospital in Tanzania, East Africa.

Acinetobacter baumannii has emerged as an important nosocomial pathogen due to its high resistance to multi-drugs and disinfectants plus its ability to survive in hospital environments. Rectal swabs were collected for screening ß-lactamases-producing Acinetobacter baumannii among hospitalized orthopedic patients at a tertiary referral hospital in Tanzania. Swabs were also taken from patients' caretakers, healthcare workers, and the neighboring inanimate environment. A total of 26 confirmed ß-lactamases producing Acinetobacter baumannii were isolated, of which 4 representative isolates (two from patients and two from hospital environment) underwent whole-genome sequencing (WGS) to detect sequence types (ST), ß-lactamases genes, plasmid replicon types, and virulence genes. All four isolates harbored multiple ß-lactamases genes including blaADC-25(3), blaOXA(4), blaCTX-M-15(2) and blaNDM-1(2). Furthermore, isolates harbored virulence genes encoding outer membrane protein (ompA), curli protein (csg), siderophore biosynthesis systems (enterobactin [entABCDEFS, fepABCDG, fes]; yersiniabactin [ybtAEPQSTUX, irp1, irp2, fyuA] and aerobactin [iucABCD, iutA]), transport secretion system type II (T2SS) and type III (T3SS), E. coli common pilus (ecpRABCDE operon), type 1 fimbriae (fim), arylsulfatase (aslA) and adhesions (fedC). Only isolates from patients harbored 4 plasmid replicons each, with the most common plasmid replicons being IncFIA_1; IncY_1 and IncFIB(AP001918)_1. Admitted orthopedic patients and the hospital environment act as a reservoir of multiple ß-lactamases producing Acinetobacter baumannii (including those against carbapenems like blaOXA and blaNDM-1) endowed with virulence genes, highlighting the necessity to routinely screening of orthopedic patients with open fractures on admission as well as reinforcing infection prevention and control measures to reduce the dissemination of nosocomial infection within the hospital environment.

Sputum smear microscopy in the Xpert® MTB/RIF era.

A balanced perspective is advocated for the assessment and application of the most recent and the oldest diagnostic methods for pulmonary tuberculosis (TB)-the molecular Xpert® MTB/RIF assay and microscopy for acid-fast bacilli. We discuss their respective merits and shortcomings and identify threats that may hamper their use in TB control. Neither test on its own provides all the information needed for diagnosis and treatment monitoring. Considering all aspects important for both individual patient care and disease control, neither seems 'better' than the other. The required advancement of microscopy had already been hampered before the introduction of the GeneXpert technology by unsuccessful and probably misguided attempts to decentralise culture-based diagnosis and drug susceptibility testing. It seems evident that systematic replacement of microscopy by Xpert is not a viable option for the foreseeable future. Instead, the two methods should complement each other to arrive at a comprehensive, accessible and continuous service for a maximum number of patients. This will intrinsically prioritise targeting the most potent transmitters with the worst prognosis, simultaneously offering optimised prospects for efficient TB control. New microscopy and Xpert applications are expected to ultimately make control programmes independent of culture-based methods in diagnosis, treatment monitoring and outcome assessment.

Sputum smear-positive, culture-negative state during anti-tuberculosis treatment in the MGIT liquid culture era.

The sputum smear-positive, culture-negative state poses a challenge for clinicians. Previous studies have shown that most samples with positive smears during the later stages of treatment are culture-negative. Earlier studies generally used solid culture media, which tend to be less sensitive than current liquid culture systems. We examined the smear-positive, culture-negative state in the era of MGIT™ 960™ liquid cultures. We found that the smear-positive, culture-negative state occurred less frequently with MGIT culture, and that the majority of the samples with late positive smears were culture-negative, regardless of media type.

Tuberculosis resistance-conferring mutations with fitness cost among HIV-positive individuals in Uganda.

BACKGROUND: Multidrug-resistant tuberculosis (MDR-TB) is considered to be less transmissible due to the fitness cost associated with drug resistance-conferring mutations in essential genes. OBJECTIVE: To test the hypothesis that TB drug resistance-conferring mutations with fitness cost are more frequent among human immunodeficiency virus (HIV) positive than among HIV-negative patients. DESIGN: We analysed all strains from the two TB drug resistance surveys conducted in Uganda between 2008 and 2011. Strains phenotypically susceptible to rifampicin and/or isoniazid were assumed to be wild-type; in all other cases, we performed whole-genome sequencing. Mutations at the rpoB531 and katG315 codons were considered without fitness loss, whereas other rpoB codons and non-katG were considered with fitness loss. RESULTS: Of the 897 TB patients, 286 (32.1%) were HIV-positive. Mutations with fitness loss in HIV-positive and HIV-negative patients were respectively as follows: non-531 rpoB: 1.03% (n = 3), 0.71% (n = 4) (OR 1.46, 95%CI 0.58-3.68); non-katG: 0.40% (n = 1), 1.0% (n = 6) (OR 0.40, 95%CI 0.07-2.20); rpoB531: 1.49% (n = 4), 0.69% (n = 4) (OR 2.29, 95%CI 0.83-5.77); katG315: 3.86% (n = 11), 2.55% (n = 15) (OR 1.54, 95%CI 0.81-2.90). The odds of mutations with and without fitness cost were higher for patients with a history of previous anti-tuberculosis treatment. CONCLUSIONS: Our data do not support the hypothesis that resistance-conferring mutations with fitness cost are likely to be often present in HIV-positive individuals.

Chest X-ray vs. Xpert® MTB/RIF assay for the diagnosis of sputum smear-negative tuberculosis in Uganda.

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.

Distinct T-cell responses when BCG vaccination is delayed from birth to 6 weeks of age in Ugandan infants.

BACKGROUND: In Uganda, the tuberculosis vaccine BCG is administered on the first day of life. Infants delivered at home receive BCG vaccine at their first healthcare facility visit at 6 weeks of age. Our aim was to determine the effect of this delay in BCG vaccination on the induced immune response. METHODS: We assessed CD4(+) and CD8(+) T-cell responses with a 12-hour whole-blood intracellular cytokine/cytotoxic marker assay, and with a 6-day proliferation assay. RESULTS: We enrolled 92 infants: 50 had received BCG vaccine at birth and 42 at 6 weeks of age. Birth vaccination was associated with (1) greater induction of CD4(+) and CD8(+) T cells expressing either interferon γ (IFN-γ) alone or IFN-γ together with perforin and (2) induction of proliferating cells that had greater capacity to produce IFN-γ, tumor necrosis factor α (TNF-α), and interleukin 2 together, compared with delayed vaccination. CONCLUSIONS: Distinct patterns of T-cell induction occurred when BCG vaccine was given at birth and at 6 weeks of age. We propose that this diversity might impact protection against tuberculosis. Our results differ from those of studies of delayed BCG vaccination in South Africa and the Gambia, suggesting that geographical and population heterogeneity may affect the BCG vaccine-induced T-cell response.

Comparison of time to positive and colony counting in an early bactericidal activity study of anti-tuberculosis treatment.

SETTING: Patients with smear-positive, newly diagnosed pulmonary tuberculosis (TB) presenting to the out-patient TB clinic in Kampala, Uganda. OBJECTIVE: To compare colony-forming unit (cfu) counting and time to positive (TTP) in Mycobacteria Growth Indicator Tube (MGIT) culture as measures of early bactericidal activity (EBA). DESIGN: Patients were enrolled in an EBA feasibility study of standard TB chemotherapy. Sixteen-hour overnight sputum collections were obtained before and on days 2, 4, 7, 10, 12 and 14 of treatment for quantitative culture on selective Middlebrook 7H11 agar media and TTP in the MGIT liquid culture system. RESULTS: Log cfu and TTP were correlated over all time points (r(s) = -0.71, P < 0.001). Within-subject (day to day) variation as a percentage of total variation was very similar between the two measures: 25.7% for cfu and 25% for TTP. Mean EBA 0-14, 0-2 and 2-14 measured by TTP were similar to those previously reported. CONCLUSION: TTP measured by an automated, standardized, commercially available culture system correlates with cfu determinations. EBA measured by TTP provides similar information to cfu counting, and is reproducible across sites and in different patient populations. These findings support replacing cfu counting with TTP as the primary measurement in EBA studies.

Time to detection of Mycobacterium tuberculosis as an alternative to quantitative cultures.

Testing new drugs is critical to improving the treatment of tuberculosis. Quantitative cultures of Mycobacterium tuberculosis on solid media have been used in Phase 1 and 2 trials, but are time and resource intensive. Time to detection (TTD) of growth of M. tuberculosis in automated liquid culture systems is an alternative. TTD has been shown to correlate with CFU in quantitative cultures, and is faster and simpler to perform. We compared TTD in the BACTEC 460 liquid culture system with CFU in a clinical trial that included 110 subjects. Comparing all sputum cultures collected between baseline and 2 months we found a strong negative correlation between log(10) CFU and TTD (rho = -0.91). In addition, when TTD at baseline was compared with 1 and 2 month sputum culture positivity, subjects whose cultures were negative after 1 and 2 months had a significantly longer median baseline TTD compared with subjects whose cultures were positive at 1 and 2 months (5 vs. 3 days and 3 vs. 2 days, respectively). TTD compares closely with CFU and represents a faster, simpler alternative to quantitative cultures.

Role of microscopic examination of stool specimens in the diagnosis of campylobacter infection from children with acute diarrhoea in Kampala, Uganda.

Campylobacter species are a frequent cause of enteritis and less often of extraintestinal infections in humans. The diagnosis of campylobacter infection depends mainly on culture which is difficult and expensive to be done as routine in most clinical microbiology laboratories in the developing countries. This study was conducted to determine the sensitivity and specificity of Gram-stain of the stool in diagnosis of campylobacter infection, using culture as the gold standard. A total of 226 stool specimens were obtained from children with acute diarrhoea, attending Mulago Hospital in Kampala, Uganda. Stool smears were made and conventional Gram stain done using 0.3% carbol-fuschin as counter stain for 5 minutes. Mucous part of the stool was cultured in Charcoal Ceferaperazone Deoxycholate Agar and blood contained selective media. A total of 21 stool samples (9.3%) were positive by culture and 17 (7.5%) by Gram stain. Sensitivity and specificity of Gram stain in the diagnosis of campylobacter infection was 76% and 99.5%, respectively with positive predictive value of 94.1%. A total of 127 (56.2%) had white blood cells (WBC) in stool and there was strong association between WBC in stool and the presence of campylobacter infection (P=0.001). Gram stain is a good alternative in diagnosis of campylobacter infection in place where facilities for culture are limited.

Evaluation of seven tests for the rapid detection of multidrug-resistant tuberculosis in Uganda.

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.

Sputum Mycobacterium tuberculosis mRNA as a marker of bacteriologic clearance in response to antituberculosis therapy.

mRNA is a marker of cell viability. Quantifying Mycobacterium tuberculosis mRNA in sputum is a promising tool for monitoring response to antituberculosis therapy and evaluating the efficacy of individual drugs. mRNA levels were measured in sputum specimens from patients with tuberculosis (TB) receiving monotherapy in an early bactericidal activity study of fluoroquinolones and in those receiving a standard rifampin-based regimen in an interleukin-2 (IL-2) trial. In the early bactericidal activity study, sputum for quantitative culture and mRNA analysis was collected for 2 days before and daily during 7 days of study drug administration. In the IL-2 trial, sputum was collected for quantitative culture, Bactec 460 liquid culture, and mRNA analysis throughout the intensive treatment phase. RNA was isolated from digested sputum and tested in quantitative reverse transcription-PCR assays for several gene targets. mRNA for the glyoxylate cycle enzyme isocitrate lyase declined at similar rates in patients receiving isoniazid, gatifloxicin, levofloxacin, and moxifloxacin monotherapy. Isocitrate lyase mRNA correlated highly with CFU in sputum prior to therapy and during 7 days of monotherapy in all treatment arms. Isocitrate lyase mRNA was detectable in sputum of culture-positive TB patients receiving a rifampin-based regimen for 1 month. At 2 months, sputum for isocitrate mRNA correlated more closely with growth in liquid culture than did growth on solid culture medium. Data suggest that isocitrate lyase mRNA is a reliable marker of M. tuberculosis viability.

Mycobacterium tuberculosis Uganda genotype is the predominant cause of TB in Kampala, Uganda.

SETTING: Rubaga Division, Kampala, Uganda. OBJECTIVE: To use polymerase chain reaction (PCR) based regions of difference (RD) analysis to study the species diversity of Mycobacterium tuberculosis complex isolates from a community-based sample of tuberculosis (TB) patients from Rubaga and to perform long sequence polymorphism (LSP) analysis to further characterise the M. tuberculosis Uganda genotype, a group of strains previously recognised by their characteristic spoligotype patterns. DESIGN: For the present study, 344 consecutive TB patients attending clinics in Rubaga Division were enrolled. Sample processing and culture were performed at the National Tuberculosis and Reference Laboratory and molecular assays at Makerere Medical School. Species identification was achieved by determining the RDs, while spoligotyping and LSP analysis were performed to characterise the M. tuberculosis Uganda genotype. RESULTS: Of the 344 isolates, 343 (99.7%) were M. tuberculosis sensu stricto, while one was classical M. bovis. The Uganda genotype strains characteristically lacked RD724, a locus that defines one of the major sub-lineages of M. tuberculosis, which suggested that this geographically constrained lineage is specifically adapted to a central African human host population. CONCLUSION: M. tuberculosis is the most prevalent species of the M. tuberculosis complex in Kampala, and the Uganda genotype is the predominant strain.

Characterization of penicillin intermediate serotypes of Streptococcus pneumoniae carried by human immunodeficiency virus-infected adults and healthy children in Uganda.

There are little data on the genetic relatedness between antibiotic-resistant pneumococcal isolates colonizing the Ugandan population. Penicillin-intermediate pneumococci of serogroups or serotypes rarely or not previously reported as being penicillin nonsusceptible were selected out of 166 isolates representing 26 capsular serogroups or serotypes isolated from Ugandan children in 1995 and human immunodeficiency virus (HIV) infected Ugandan adults in 2004-2005. Pairs of penicillin-intermediate pneumococci of the same serogroup or serotype present in both patient populations were characterized further by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). Seven such pairs of isolates were found and included serogroups 7, 11, 15B/C, and 16 as well as serotypes 13, 21, and 35B. PFGE of these seven pairs showed no clonality between serogroups or serotypes, and clonality only within serogroup 11 and serotype 13. MLST of the 14 individual isolates revealed 13 different sequence types (STs), 11 of which had not previously been recorded. Comparisons with all known STs revealed that most of these strains were related only to strains of the same serotype in other countries, with these related strains frequently also being penicillin intermediate. These findings suggest that penicillin nonsusceptibility in Uganda is likely due to the introduction of antibiotic-resistant pneumococcal clones into Uganda rather than development of resistance within the country.

Introduction of an in-house PCR for routine identification of M. tuberculosis in a low-income country.

SETTING: National Tuberculosis (TB) Treatment Centre, Makerere University Medical School and Joint Clinical Research Centre, Kampala, Uganda. OBJECTIVE: To evaluate the introduction of a polymerase chain reaction (PCR) based assay for identification of the Mycobacterium tuberculosis complex (MTC) into routine practice. DESIGN: Routine diagnostic specimens were processed and inoculated into Bactec 12B vials and monitored daily. At a growth index (GI) > or =10, 0.5 ml of the 12B broth was removed and assayed with PCR. The same 12B vial was analyzed using the Bactec NAP method at GI > or =500. Vials at various levels of GI were included. Recurrent cost and time required to perform PCR and NAP were compared. RESULTS: Initially, 71 specimens were analyzed; of these, 68 were NAP-positive while 69 were PCR-positive for MTC. PCR resulted in a 75% reduction in cost for a single test compared with Bactec NAP. PCR has been successfully incorporated into routine practice, and 432 samples have been analyzed. In addition, isolates from solid media were also well identified by PCR. With PCR, more samples can be analyzed at a time, it is faster and is less labor intensive. CONCLUSION: PCR is a reliable and cheaper alternative for the identification of MTC.

The species Mycobacterium africanum in the light of new molecular markers.

The findings of recent studies addressing the molecular characteristics of Mycobacterium tuberculosis complex isolates have initiated a discussion on the classification of M. africanum, especially of those isolates originating from East Africa (cluster F, subtype II) and displaying phenotypic and biochemical characteristics more similar to those of M. tuberculosis. To further address this question, we analyzed a representative collection of 63 M. tuberculosis complex strains comprising 30 M. africanum subtype I strains, 20 M. africanum subtype II strains, 10 randomly chosen M. tuberculosis isolates, and type strains of M. tuberculosis, M. bovis, and M. africanum for the following biochemical and molecular characteristics: single-nucleotide polymorphisms (SNPs) in gyrB and narGHJI and the presence or absence of RD1, RD9, and RD12. For all molecular markers analyzed, subtype II strains were identical to the M. tuberculosis strains tested. In contrast, the subtype I strains as well as the M. africanum type strain showed unique combinations of SNPs in gyrB and genomic deletions (the absence of RD9 and the presence of RD12), which proves their independence from M. tuberculosis and M. bovis. Accordingly, all subtype I strains displayed main biochemical characteristics included in the original species description of M. africanum. We conclude that the isolates from West Africa were proved to be M. africanum with respect to the phenotypic and genetic markers analyzed, while the isolates from East Africa must be regarded as phenotypic variants of M. tuberculosis (genotype Uganda). We propose the addition of the molecular characteristics defined here to the species description of M. africanum, which will allow clearer species differentiation in the future.

Mycobacterium africanum subtype II is associated with two distinct genotypes and is a major cause of human tuberculosis in Kampala, Uganda.

The population structure of 234 Mycobacterium tuberculosis complex strains obtained during 1995 and 1997 from tuberculosis patients living in Kampala, Uganda (East Africa), was analyzed by routine laboratory procedures, spoligotyping, and IS6110 restriction fragment length polymorphism (RFLP) typing. According to biochemical test results, 157 isolates (67%) were classified as M. africanum subtype II (resistant to thiophen-2-carboxylic acid hydrazide), 76 isolates (32%) were classified as M. tuberculosis, and 1 isolate was classified as classical M. bovis. Spoligotyping did not lead to clear differentiation of M. tuberculosis and M. africanum, but all M. africanum subtype II isolates lacked spacers 33 to 36, differentiating them from M. africanum subtype I. Moreover, spoligotyping was not sufficient for differentiation of isolates on the strain level, since 193 (82%) were grouped into clusters. In contrast, in the IS6110-based dendrogram, M. africanum strains were clustered into two closely related strain families (Uganda I and II) and clearly separated from the M. tuberculosis isolates. A further characteristic of both M. africanum subtype II families was the absence of spoligotype spacer 40. All strains of family I also lacked spacer 43. The clustering rate obtained by the combination of spoligotyping and RFLP IS6110 analysis was similar for M. africanum and M. tuberculosis, as 46% and 49% of the respective isolates were grouped into clusters. The results presented demonstrate that M. africanum subtype II isolates from Kampala, Uganda, belong to two closely related genotypes, which may represent unique phylogenetic branches within the M. tuberculosis complex. We conclude that M. africanum subtype II is the main cause of human tuberculosis in Kampala, Uganda.

Pneumococcal conjugate vaccine serotypes of Streptococcus pneumoniae isolates and the antimicrobial susceptibility of such isolates in children with otitis media.

The ability of the recently licensed 7-valent pneumococcal conjugate vaccine to cover isolates that cause otitis media, especially drug-resistant ones, was assessed using 500 recently obtained US isolates. Of these isolates, 418 (84%) belonged to vaccine-related serogroups, whereas 82 (16%) belonged to non-vaccine-related serogroups. Serotype 3 accounted for 48 (59%) of the non-vaccine-related serogroups. In addition, 93% of the isolates from patients < or =3 years of age belonged to serotypes that were included in or related to the heptavalent vaccine, compared with 49% of the isolates from older patients (P=.001). Most of the isolates (98%-100%) that were resistant to the antimicrobial agents tested were covered by the heptavalent vaccine, including 95.1% of the isolates from patients <2 years of age. The 7-valent pneumococcal conjugate vaccine could therefore potentially provide protection against all but 1 (type 3) of the common otitis media-associated pneumococcal serogroups identified in this study as well as against 98% of antibiotic-resistant isolates.

Evaluation of suspected tuberculous pleurisy: clinical and diagnostic findings in HIV-1-positive and HIV-negative adults in Uganda.

SETTING: National Tuberculosis Treatment Centre, Mulago Hospital, Kampala, Uganda. OBJECTIVES: To compare clinical and radiographic presentation, and diagnostic methods, in adults with tuberculous pleurisy who are negative and positive for the human immunodeficiency virus (HIV). DESIGN: Adults with suspected pleural tuberculosis were screened by clinical examination, thoracocentesis and closed pleural biopsy. Biopsy material was cultured on Middlebrook 7H-10 solid medium and in BACTEC 12B radiometric vials. Pleural fluid was cultured using Löwenstein-Jensen slants, BACTEC and Kirchner liquid medium. RESULTS: Of 156 individuals enrolled, 142 had tuberculosis, of whom 80% were HIV-positive. Among those with tuberculosis, HIV-positive patients bad a more severe and longer illness. The size of effusions was similar in HIV-positive and HIV-negative patients. A higher proportion of HIV-positive patients had parenchymal infiltrates but this difference was not statistically significant. Pleural fluid lymphocytosis was present in all HIV-negative and 97% of the HIV-positive patients. HIV-positive patients had lower pleural fluid lymphocyte counts. Pleural fluid cultures were more often positive in HIV-positive patients. BACTEC and Kirchner liquid media gave higher yields than solid media. CONCLUSION: HIV-positive patients with tuberculous pleurisy had a more severe illness than HIV-negative patients. Mycobacterial cultures from HIV-positive patients were more often positive, suggesting more mycobacterial extension from the lungs into the pleural space. Liquid culture media were superior to solid media with regard to diagnostic yield and time until diagnosis.

Quantitative bacillary response to treatment in Mycobacterium tuberculosis infected and M. africanum infected adults with pulmonary tuberculosis.

Data regarding possible differences in microbiological response to therapy of disease caused by Mycobacterium tuberculosis and M. africanum are limited. Presenting clinical characteristics and sputum bacillary load during standard short-course chemotherapy in patients with newly-diagnosed pulmonary tuberculosis due to M. tuberculosis (n = 7) and M. africanum (n = 6) were compared. Changes in sputum bacillary load were measured using quantitative acid-fast bacilli smears, colony forming unit assay, and time until positive culture in the BACTEC radiometric system. Presentation and response to short course chemotherapy were comparable between patients infected with M. tuberculosis and those infected with M. africanum.

High prevalence of carriage of antibiotic-resistant Streptococcus pneumoniae in children in Kampala Uganda.

There are few data on antibiotic-resistant Streptococcus pneumoniae in Uganda. A total of 191 healthy children in Kampala, Uganda were screened for nasopharyngeal carriage of S. pneumoniae; 118 (62%) of the children were carriers. Antimicrobial susceptibility and serotype of 115 strains was determined. Ninety-six (83.5%) of the isolates were of intermediate resistance to penicillin and 19 (16.5%) were susceptible. All strains were susceptible to cefotaxime. The rates of resistance to other drugs were trimethoprim-sulphamethoxazole (83.5%), tetracycline (28.7%) and chloramphenicol (10.4%). All strains were susceptible to rifampicin, erythromycin and clindamycin. Serogroups 6, 9, 14, 19 and 23 accounted for 80% of the isolates. These data show that the rate of carriage of antibiotic-resistant pneumococci by children is high in Kampala, Uganda.