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.Key words: Drug resistance, Microbial; Mycobacterium tuberculosis; Risk factors; Tuberculosis; South Africa     

Detection of neonatal unit clusters of Candida parapsilosis fungaemia by microsatellite genotyping: Results from laboratory‐based sentinel surveillance,South Africa, 2009‐2010

Neonatal candidaemia is a common, deadly and costly hospital‐associated disease. To determine the genetic diversity of Candida parapsilosis causing fungaemia in South African neonatal intensive care units (NICUs). From February 2009 through to August 2010, cases of candidaemia were reported through laboratory‐based surveillance. C. parapsilosis isolates from neonatal cases were submitted for identification by internal transcribed spacer (ITS) region sequencing, antifungal susceptibility testing and microsatellite genotyping. Cluster analysis was performed using Unweighted Pair Group Method with Arithmetic Mean (UPGMA). Of 1671 cases with a viable Candida isolate, 393 (24%) occurred among neonates. Isolates from 143 neonatal cases were confirmed as C. parapsilosis sensu stricto. Many isolates were resistant to fluconazole (77/143; 54%) and voriconazole (20/143; 14%). Of 79 closely‐related genotypes, 18 were represented by ≥2 isolates; 61 genotypes had a single isolate each. Seven clusters, comprised of 82 isolates, were identified at five hospitals in three provinces. Isolates belonging to certain clusters were significantly more likely to be fluconazole resistant: all cluster 7 isolates and the majority of cluster 4 (78%), 5 (89%) and 6 (67%) isolates (P<.001). Candida parapsilosis‐associated candidaemia in public‐sector NICUs was caused by closely related genotypes and there was molecular evidence of undetected outbreaks as well as intra‐hospital transmission.     

IS6110 Restriction Fragment Length Polymorphism Typing of Drug-resistant Mycobacterium tuberculosis Strains from Northeast South Africa

Tuberculosis (TB) remains a deadly infectious disease affecting millions of people worldwide; 95% of TB cases, with 98% of death occur in developing countries. The situation in South Africa merits special attention. A total of 21,913 sputum specimens of suspected TB patients from three provinces of South Africa routinely submitted to the TB laboratory of Dr. George Mukhari (DGM) Hospital were assayed for Mycobacterium tuberculosis (MTB) growth and antibiotic susceptibility. The genetic diversity of 338 resistant strains were also studied. DNA isolated from the strains were restricted with Pvu II, transferred on to a nylon membrane and hybridized with a PCR-amplified horseradish peroxidase 245 bp IS6110 probe. Of the 338 resistant strains, 2.09% had less than 5 bands of IS6110, and 98% had 5 or more bands. Unique restriction fragment length polymorphism (RFLP) patterns were observed in 84.3% of the strains, showing their epidemiological independence, and 15.7% were grouped into 22 clusters. Thirty-two strains (61.5%) from the 52 that clustered were from Mpumalanga, 16/52 (30.8%) from Gauteng, and 4/52 (9.6%) from Limpopo province. Clustering was not associated with age. However, strains from male patients in Mpumalanga were more likely to be clustered than strains from male patients in Limpopo and/or Gauteng province. The minimum estimate for the proportion of resistant TB that was due to transmission is 9.06% (52-22=30/331). Our results indicate that transmission of drug-resistant strains may contribute substantially to the emergence of drug-resistant tuberculosis in South Africa.Key words: Drug resistance, Epidemiology, IS6110, M. tuberculosis, PCR-RFLP, South Africa     

Emergence of multi-drug-resistant Acinetobacter anitratus species in neonatal and paediatric intensive care units in a developing country: concern about antimicrobial policies

Antimicrobial abuse is a serious risk factor for the emergence of multi-drug-resistant (MDR) pathogens. We report on the emergence of multi-drug-resistant Acinetobacter anitratus species over two 8-week periods in 1999 in the neonatal and paediatric intensive care units (NICU and PICU) of King Edward VII Hospital, Durban, South Africa. The source, transmission dynamics, microbiological evaluations, antibiotic utilization patterns and outcome were evaluated. MDR Acinetobacter anitratus was isolated from different body sites in 23 infants less than 2 months of age, 18 in the PICU and five in the NICU. The mortality was 56.5% and two survivors required re-admission. Ten of the 23 cases had entered the ICU with MDR Acinetobacter anitratus. Eleven of the study infants had received broad-spectrum antimicrobial agents before entering the ICU, while all infants with nosocomially acquired MDR Acinetobacter anitratus had received broad-spectrum antimicrobial agents. All the surgical cases with MDR Acinetobacter anitratus died. Microbiological data from both ICUs for 1999 indicated that gram-negative bacteria accounted for two-thirds of isolates, Acinetobacter anitratus and Klebsiella pneumoniae accounting for 33% and 27% of the isolates, respectively. Only 53% and 57% of all Acinetobacter spp isolates were susceptible to piperacillin/tazobactam and carbepenems, respectively. MDR Acinetobacter anitratus is an emerging problem to which antimicrobial abuse contributes.     

Oral and oropharyngeal high-risk HPV prevalence,HIV status,and risk behaviours in a cohort of South African men who have sex with men

Data lag is evident when observing studies focussing on human papillomavirus (HPV) prevalence in the head and neck of men who have sex with men (MSM) in Southern Africa. Sexual behaviours other than anal intercourse, and associated factors are similarly underreported. HPV vaccination has not yet commenced for this population group. One hundred and ninety-nine MSM were enrolled in this study. Participants completed a questionnaire followed by a clinical oral examination, and a rinse-and-gargle specimen in Thinprep^® vials containing Preservcyt^® solution was collected. Detection and genotyping for high-risk HPV were done by an automated system (Abbott^® m2000sp). Six percent of MSM in this cohort had high-risk HPV present in the mouth/oropharynx. This cohort averages 29 years of age, more than half were unemployed (53.3%), and 66.8% were human immunodeficiency virus (HIV) seropositive. The most common sexual practice was anal sex (69.4%) followed by oral sex (28.6%), and by rimming (9.6%). A significant association between oral insertive sex and oral/oropharyngeal HPV status was demonstrated (p = 0.0038; phi coefficient = 0.20). An incidental but significant association between rimming and HIV status was found (p = 0.0046; phi coefficient = 0.19), and HIV seropositive participants had higher oral/oropharyngeal HPV presence. The HPV prevalence of 6% reported in this study is in alignment with global reports. The prevalence of oral/oropharyngeal HPV in this MSM cohort was influenced by sexual practices. MSM participants who practiced rimming appear to be at higher risk of HIV acquisition. Given the transmission routes of HPV in this vulnerable population, vaccination must be urgently studied as an intervention for prevention.