Introduction We aimed to obtain an in-depth understanding on recent antimicrobial resistance trends and molecular epidemiology trends of S. aureus bacteraemia (SAB). Methods Thirteen academic centres ...in South Africa were included from June 2010 until July 2012. S. aureus susceptibility testing was performed on the MicroScan Walkaway. Real-time PCR using the LightCycler 480 II was done for mecA and nuc. SCCmec and spa-typing were finalized with conventional PCR. We selected one isolate per common spa type per province for multilocus sequence typing (MLST). Results S. aureus from 2709 patients were included, and 1231 (46%) were resistant to methicillin, with a significant decline over the three-year period (p-value = 0.003). Geographical distribution of MRSA was significantly higher in Gauteng compared to the other provinces (P<0.001). Children <5 years were significantly associated with MRSA with higher rates compared to all other age groups (P = 0.01). The most prevalent SCCmec type was SCCmec type III (531 41%) followed by type IV (402 31%). Spa-typing discovered 47 different spa-types. The five (87%) most common spa-types were t037, t1257, t045, t064 and t012. Based on MLST, the commonest was ST612 clonal complex (CC8) (n = 7) followed by ST5 (CC5) (n = 4), ST36 (CC30) (n = 4) and ST239 (CC8) (n = 3). Conclusions MRSA rate is high in South Africa. Majority of the isolates were classified as SCCmec type III (41%) and type IV (31%), which are typically associated with hospital and community- acquired infections, respectively. Overall, this study reveals the presence of a variety of hospital-acquired MRSA clones in South Africa dominance of few clones, spa 037 and 1257. Monitoring trends in resistance and molecular typing is recommended to detect changing epidemiological trends in AMR patterns of SAB.
Introduction Group B Streptococcus (GBS) is a leading cause of neonatal sepsis and meningitis. We aimed to evaluate the burden of invasive early-onset (0-6 days of life, EOD) and late-onset (7-89 ...days, LOD) GBS disease and subsequent neurological sequelae in infants from a setting with a high prevalence (29.5%) of HIV among pregnant women. Methods A case-control study was undertaken at three secondary-tertiary care public hospitals in Johannesburg. Invasive cases in infants <3 months age were identified by surveillance of laboratories from November 2012 to February 2014. Neurodevelopmental screening was done in surviving cases and controls at 3 and 6 months of age. Results We identified 122 cases of invasive GBS disease over a 12 month period. Although the incidence (per 1,000 live births) of EOD was similar between HIV-exposed and HIV-unexposed infants (1.13 vs. 1.46; p = 0.487), there was a 4.67-fold (95%CI: 2.24-9.74) greater risk for LOD in HIV-exposed infants (2.27 vs. 0.49; p<0.001). Overall, serotypes Ia, Ib and III constituted 75.8% and 92.5% of EOD and LOD, respectively. Risk factors for EOD included offensive draining liquor (adjusted Odds Ratio: 27.37; 95%CI: 1.94-386.50) and maternal GBS bacteriuria (aOR: 8.41; 95%CI: 1.44-49.15), which was also a risk-factor for LOD (aOR: 3.49; 95%CI: 1.17-10.40). The overall case fatality rate among cases was 18.0%. The adjusted odds for neurological sequelae at 6 months age was 13.18-fold (95%CI: 1.44-120.95) greater in cases (13.2%) than controls (0.4%). Discussion The high burden of invasive GBS disease in South Africa, which is also associated with high case fatality rates and significant neurological sequelae among survivors, is partly due to the heightened risk for LOD in infants born to HIV-infected women. An effective trivalent GBS conjugate vaccine targeted at pregnant women could prevent invasive GBS disease in this setting.
Shigellosis is a global human health problem. The disease is most prevalent in developing countries with poor access to safe potable water and sanitation. Shigella boydii is of particular ...epidemiological importance in developing nations such as African and Asian countries. In the present study, we report on the analysis of a temporal cluster of 29 S. boydii serotype 2 strains, isolated in the Mpumalanga Province of South Africa (SA) over the period of November to December 2007.
Bacteria were identified as S. boydii using standard microbiological identification techniques and serotyped using commercially available antisera. Susceptibility testing to antimicrobial agents was determined by the Etest. Genotypic relatedness of strains was investigated by pulsed-field gel electrophoresis (PFGE) analysis of digested genomic DNA.
The cluster of 29 isolates revealed comparable antimicrobial susceptibility profiles, while dendrogram analysis of PFGE patterns showed that the cluster of isolates grouped together and could clearly be differentiated from a random selection of unrelated S. boydii serotype 2 strains. Our data has strongly suggested that this cluster of isolates may share a common ancestry. However, this cannot be substantiated by epidemiological data because a detailed epidemiological investigation was not conducted.
We have documented the first cluster of S. boydii infection in SA. Due to the lack of adequate epidemiological investigation, we cannot emphatically state that an outbreak had occurred. However, we do hypothesis that this was an outbreak for which a waterborne source cannot be excluded. This study has highlighted the urgent need for timely and appropriate systems of epidemiological investigation of all suspected outbreaks of disease in developing countries.
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