Search

An essential metric for determining the efficacy of tuberculosis (TB) control programs is the evaluation of TB treatment outcomes. Assessing treatment outcomes is fundamental to facilitating the End TB Strategy set target. Clinic records from 457 patients with DR-TB were examined for data collection while 101 patients were followed up prospectively. Data were analyzed using Stata version 17.0. The odds ratio and 95% confidence interval were calculated to check the association between variables. P ≤ 0.05 was con-sidered statistically significant. Of the 427 participants, 65.8% had successful treatment whilst 34.2% had unsuccessful TB treatment. A total of 61.2% and 39% of the HIV-positive and HIV-negative participants had a successful TB treatment whilst 66% and 34% of both HIV-negative and positive participants had unsuccessful TB treatment. From 101 patients that were followed up, smokers had longer treatment outcomes compared to non-smokers. In the study with HIV/TB co-infection, men predominated. HIV and tuberculosis co-infection made therapy difficult with unfavorable effects on TB management. The treatment success rate (65.8%) is lower than the WHO threshold standard with a high proportion of patients lost to follow-up. The co-infection of tuberculosis and HIV resulted in undesirable treatment outcomes. Strengthening TB surveillance and control is recommended.

In South Africa, drug-resistant tuberculosis (DR-TB) continues to be a serious public health issue. Gene mutations and the genotyping of DR-TB in a rural Eastern Cape Province have not previously been studied. We detected prevalent mutations of DR-TB, identified genetic diversity, and assigned lineages. Sputum specimens obtained from 1157 patients suspected with tuberculosis were assayed for rifam-pin-resistance using Xpert® MTB/RIF.and detection of mutations conferring resistance to anti-TB drugs was carried out using GenoType MTBDRplus VER 2.0. Thereafter, 441 isolates were spoligotyped. The most prevalent rifampin resistance-conferring mutations were in rpoB codon S531L. The INH resistant strains, 54.5% had mutations in katG gene at codon S315TB and 24.7% with mutations in inhA gene at codon C-15TB. Furthermore 69.9% strains displayed mutations involving both rpoB and katG genes, while 24.6% strains displayed mutations involving both rpoB and inhA genes. Overall prevalence of hetero-resistance was 17.9%. Beijing family was predominant from Spoligotyping analysis. The diversity of mutations in the study provides information for investigating the evolutional lineages of M. tuberculosis isolates. The recognition frequency of rpoB, katG and inhA mutations in different study areas may help to guide decision‑making about standardization of treatment regimens or individualized treatment in areas where these mutations have been found.

Drug-resistant tuberculosis (DR-TB) remains a major public health problem in South Africa. Gene mu-tations and the genotyping of DR-TB in a rural Eastern Cape Province have not previously been studied. Hence, we sought to detect prevalent mutations linked to DR-TB profiles, identify genetic diversity, and assign lineages. Sputum specimens were obtained from 1157 patients suspected with tuberculosis. They were assayed for rifampin-resistance using Xpert® MTB/RIF.and detection of mutations conferring re-sistance to anti-TB drugs was carried out using GenoType MTBDRplus VER 2.0. Thereafter, 441 isolates were spoligotyped. The most prevalent rifampin resistance-conferring mutations were in rpoB codon S531L. The INH resistant strains, 54.5% had mutations in katG gene at codon S315TB and 24.7% with mutations in inhA gene at codons C-15TB. Furthermore 69.9% strains displayed mutations involving both rpoB and katG genes, while 24.6% strains displayed mutations involving both rpoB and inhA genes. The overall prevalence of heteroresistance was 17.9%. Spoligotyping analysis generated 410 patterns of iso-lates which were found in the international database, with Beijing family being predominant. The diversity of mutations in the study provides information for investigating the evolutional lineages of M. tuberculosis isolates. The recognition frequency of rpoB, katG and inhA mutations in different study areas may help to guide decision‑making about standardization of treatment regimens or individualized treatment in areas where these mutations have been found. This calls for increased drug resistance surveillance and rein-forcement of TB control in this area.

Tuberculosis (TB), an infectious airborne disease caused by Mycobacterium tuberculosis (Mtb), is a serious public health threat reported as the leading cause of morbidity and mortality worldwide. South Africa is a high TB burden country with TB being the highest infectious disease killer. The study investigated the distribution and clustering of Mtb mutations and spoligotypes in rural Eastern Cape Province. The Mtb isolates included were 1,157 from DR-TB patients and analysed by LPA followed by spoligotyping of 441 isolates, of these, 36 were whole genome sequenced. Distribution of mutations and spoligotypes was done by spatial analysis and clustering analysis was done by Bayesian model-based clustering of allele frequencies at heterozygous sites, using Mclust package in R. The rpoB gene had highest number of mutations. The distribution of rpoB and katG mutations was more prevalent in four health care facilities, inhA mutations were more prevalent in three healthcare facilities and heteroresistant isolates were more prevalent in five healthcare facilities. The Mtb was genetically diverse with Beijing more prevalent and largely distributed. Spatial analysis and mapping of gene mutations and spoligotypes revealed better picture of distribution. Clustering of isolates indicates that there is transmission of mixed infection in this area.

INTRODUCTION The prevalence of azole resistance in C parapsilosis is very low in most parts of the world. However, South Africa has reported an exceptionally high prevalence of azole resistance in C parapsilosis strains isolated from candidaemia cases. We aimed to determine the possible molecular mechanisms of fluconazole resistance in C parapsilosis isolates obtained through surveillance at a large neonatal unit at a South African academic hospital. METHODS We sequenced the ERG11 and MRR1 genes of C parapsilosis isolates recovered from cases of neonatal candidemia, followed by microsatellite genotyping. A total of 73 isolates with antifungal susceptibility results were analysed. RESULTS Of these, 57 (78%) were resistant, 11 (15%) susceptible dose-dependent and 5 (7%) susceptible. The most commonly identified amino acid substitution within the ERG11 gene was Y132F in 68% (39/57) of fluconazole-resistant isolates and none in susceptible isolates. Three amino acid substitutions (R405K, G583R and A619V) and 1 nucleotide deletion at position 1331 were identified within MRR1 gene in 19 (26%) isolates. Microsatellite genotyping grouped isolates into four clusters (50 isolates). Cluster 1 accounted for 23% (17/73) of all cases, cluster 2 for 22% (16/73), cluster 3 for 14% (10/73) and cluster 4 for 10% (7/73). We found an association between cluster type and fluconazole resistance (P-value = .004). Isolates harbouring the Y132F substitution were more likely to belong to a cluster than non-Y132F isolates. CONCLUSION Fluconazole resistance in C parapsilosis strains from a single South African neonatal unit was associated with cluster type and predominantly driven by Y123F amino acid substitutions in the ERG11 gene.

Evaluation of resistant profiles and detection of antimicrobial-resistant genes of bacterial pathogens in the nonclinical milieu is imperative to assess the probable risk of dissemination of resistant genes in the environment. This paper sought to identify antibiotic-resistant genes in Pseudomonas aeruginosa from nonclinical sources in Mthatha, Eastern Cape, and evaluate its public health implications. Samples collected from abattoir wastewater and aquatic environment were processed by membrane filtration and cultured on CHROMagarTM Pseudomonas medium. Species identification was performed by autoSCAN-4 (Dade Behring Inc., IL). Molecular characterization of the isolates was confirmed using real-time polymerase chain reaction (rPCR) and selected isolates were further screened for the possibility of harboring antimicrobial resistance genes. Fifty-one Pseudomonas species were recovered from abattoir wastewater and surface water samples, out of which thirty-six strains were Pseudomonas aeruginosa (70.6%). The P. aeruginosa isolates demonstrated resistance to aztreonam (86.1%), ceftazidime (63.9%), piperacillin (58.3%), cefepime (55.6%), imipenem (50%), piperacillin/tazobactam (47.2%), meropenem (41.7%), and levofloxacin (30.6%). Twenty out of thirty-six P. aeruginosa displayed multidrug resistance profiles and were classified as multidrug-resistant (MDR) (55.6%). Most of the bacterial isolates exhibited a high Multiple Antibiotic Resistance (MAR) Index ranging from 0.08 to 0.69 with a mean MAR index of 0.38. In the rPCR analysis of fifteen P. aeruginosa isolates, 14 isolates (93.3%) were detected harboring blaSHV, six isolates (40%) harbored blaTEM, and three isolates (20%) harbored blaCTX-M, being the least occurring ESBL. Results of the current study revealed that P. aeruginosa isolates recovered from nonclinical milieu are resistant to frontline clinically relevant antipseudomonal drugs. This is concerning as it poses a risk to the environment and constitutes a public health threat. Given the public health relevance, the paper recommends monitoring of multidrug-resistant pathogens in effluent environments.

Introduction Carbapenem-resistant Acinetobacter baumannii has been responsible for an increasing number of hospital-acquired infections globally. The study investigated the prevalence of carbapenemase-encoding genes in clinical multidrug-resistant A. baumannii strains. Materials and Methods A total of 100 nonduplicate multidrug-resistant A. baumannii strains were cultured from clinical samples obtained from healthcare facilities in the O. R. Tambo district. The strains were confirmed by detecting the intrinsic blaOXA-51-like gene. Antimicrobial susceptibility testing was performed by VITEK® 2 and autoSCAN-4 systems. The MIC of imipenem and meropenem was rechecked by E-test. Colistin MIC was confirmed by the broth microdilution method. Real-time PCR was performed to investigate the presence of carbapenemase-encoding genes. Results Most strains showed high resistance rates (>80%) to the antibiotics tested. Resistance to amikacin, tetracycline, and tigecycline were 50%, 64%, and 48%, respectively. All strains were fully susceptible to colistin. The blaOXA-51-like was detected in all strains whilst blaOXA-23-like, blaOXA-58-like, blaOXA-24-like, blaIMP-1, blaVIM, and blaNDM-1 were found in 70%, 8%, 5%, 4%, 3%, and 2% of strains, respectively. None of the tested strains harboured the genes blaSIM and blaAmpC. The coexistence of blaOXA-23-like, and blaIMP-1 or blaOXA-58-like was detected in 1% and 2% strains, respectively. A distinct feature of our findings was the coharbouring of the genes blaOXA-23-like, blaOXA-58-like, and blaIMP-1 in 2% strains, and this is the first report in the Eastern Cape Province, South Africa. The intI1 was carried in 80% of tested strains whilst ISAba1/blaOXA-51-like and ISAba1/blaOXA-23-like were detected in 15% and 40% of the strains, respectively. The detection of blaOXA-23-like, ISAba1/blaOXA-51-like, ISAba1/blaOXA-23-like, and blaOXA-23-like, blaOXA-58-like, and blaIMP-1 carbapenemases in strains had a significant effect on both imipenem and meropenem MICs. Conclusions Results showed a high level of oxacillinases producing A. baumannii circulating in our study setting, highlighting the need for local molecular surveillance to inform appropriate management and prevention strategies.