Surveillance and comparison of antimicrobial susceptibility patterns of ESKAPE organisms isolated from patients with bacteraemia in South Africa, 2016 - 2017

Background. In South Africa (SA), the National Department of Health has developed an Antimicrobial Resistance National Strategy Framework document to manage antimicrobial resistance (AMR). One of the strategic objectives is to optimise surveillance and early detection of AMR. At the National Institute for Communicable Diseases (NICD), an analysis of selected organisms and antimicrobial agents from both the public and the private sectors was conducted.Objectives. The relevance of surveillance for AMR is increasingly recognised in the light of global action plans to combat resistance. In this report, we present an overview of ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp.) organisms and Escherichia coli reported from public and private sector laboratories in SA for the period 2016 - 2017.Methods. Antimicrobial susceptibility testing (AST) profiles on selected ESKAPE organisms and E. coli isolated from blood cultures from the public and private sectors in 2016 and 2017 were analysed. AST data were extracted from a web-based electronic platform created by the NICD. Drug-bug combinations following the World Health Organization’s Global Antimicrobial Surveillance System guidelines were included in the analysis.Results. A total of 28 920 ESKAPE organisms and E. coli were reported in 2016 and 32 293 in 2017 across the two health sectors. Proportions of some organisms differed between the two health sectors, such as E. coli (19% in the public sector and 36% in the private sector), A. baumannii (14% public and 4% private), P. aeruginosa (7% public and 11% private) and S. aureus (27% public and 17% private). Susceptibility data indicated changing patterns in both sectors towards an increase in non-susceptibility to carbapenems in K. pneumoniae (p<0.01). However, we demonstrated an increase in susceptibility to cloxacillin in S. aureus (p<0.01) in both sectors.Conclusions. The key clinically important finding is the rapidly decreasing carbapenem susceptibility among Enterobacteriaceae reported in SA, irrespective of sector. In addition, the analysis provides information that could be used to monitor the effectiveness of interventions implemented at a national level under the guidance and direction of the national AMR framework.

Experimental phage therapy against haematogenous multi-drug resistant <i>Staphylococcus aureus</i> pneumonia in mice

Background: Community-acquired haematogenous Staphylococcus aureus pneumonia is a rare infection, though it can be acquired nosocomially. Currently, antibiotics used against S. aureus pneumonia have shown reduced efficacy. Thus, there is need for an alternative therapy against multidrug-resistant S. aureus (MDRSA) strains in the community. Objective: We sought to determine the efficacy of environmentally-obtained S. aureus lytic phage against haematogenous MDRSA pneumonia in mice. Methods: Phages and MDRSA were isolated from sewage samples collected within Nairobi County, Kenya. Isolated S. aureus bacteria were screened for resistance against ceftazidime, oxacillin, vancomycin, netilmicin, gentamicin, erythromycin, trimethroprim-sulfamethoxazole and cefuroxime. Thirty BALB/c mice aged six to eight weeks were randomly assigned into three groups: the MDRSA-infection group (n = 20), the phage-infection group (n = 5) and the non-infection group (n = 5). Mice were infected with either MDRSA or phage (108 CFU/mL) and treated after 72 hours with a single dose of clindamycin (8 mg/kg/bwt) or 108 PFU/mL of phage or a combination therapy (clindamycin and phage). The efficacy of phage, clindamycin or clindamycin with phage combination was determined using resolution of lung pathology and bacterial load in lung homogenates. Results: The viable MDRSA count was 0.5 ± 0.2 log10 CFU/gm in the phage-treated group,   4.4 ± 0.2 log10 CFU/gm in the clindamycin-treated group and 4.0 ± 0.2 log10 CFU/gm in the combination-treated group. The efficacy of phage therapy was significantly different from other therapeutic modes (p = 0 < 0.0001). Histology showed that the mice treated with phage did not develop pneumonia. Conclusion: Phage therapy is effective against haematogenous MDRSA infection. Thus, it can be explored as an alternative treatment method

Which facial views for facial trauma?

Report by Kerstin Hogg, Clinical Research Fellow 
Checked by Margaret Maloba, Specialist Registra

Rectal or intravenous non-steroidal anti-inflammatory drugs in acute renal colic

Report by Caroline Lee, Specialist Registrar 
Checked by Dhurga Gnanasegaram and Margaret Maloba, Specialist Registrar

Characterisation of mobile colistin resistance genes (mcr‑3 and mcr‑5) in river and storm water in regions of the Western Cape of South Africa

CITATION: Snyman, Y., et al. 2021. Characterisation of mobile colistin resistance genes (mcr‑3 and mcr‑5) in river and storm water in regions of the Western Cape of South Africa. Antimicrobial Resistance and Infection Control, 10:96, doi:10.1186/s13756-021-00963-2.The original publication is available at https://aricjournal.biomedcentral.comPublication of this article was funded by the Stellenbosch University Open Access FundBackground: Colistin is regarded as a last-resort antimicrobial against multi-drug resistant Gram-negative bacteria (GNB), therefore the dissemination of colistin resistance in the environment is of great concern. Horizontal transfer of mobile colistin resistance (mcr) genes to potential pathogens poses a serious problem. This study aimed to describe the presence of colistin resistant GNB and mcr genes in river and storm water in regions of the Western Cape. Methods: Water samples were collected from three rivers during May 2019 and January 2020 and two storm water samples were collected in November 2019. Colistin resistant GNB were cultured on MacConkey agar containing colistin and identified by MALDI-TOF. Colistin resistance was confirmed using broth microdilution (BMD). mcr-1-5 genes were detected by PCR performed directly on the water samples and on the colistin resistant isolates. mcr functionality was assessed by BMD after cloning the mcr genes into pET-48b(+) and expression in SHuffle T7 E. coli. Results: mcr-5.1 and various mcr-3 gene variants were detected in the Plankenburg-, Eerste- and Berg rivers and in storm water from Muizenberg, and only mcr-5.1 was detected in storm water from Fish Hoek. Colistin resistant GNB were isolated from all of the water sources. Aeromonas spp. were the most common colistin resistant organisms detected in the water sources; 25% (6/24) of colistin resistant Aeromonas spp. isolated from the Berg river contained novel mcr-3 variants; mcr-3.33 (n = 1), mcr-3.34 (n = 1) mcr-3.35 (n = 1) mcr-3.36 (n = 2) and mcr-3.37 (n = 1), which were confirmed to confer colistin resistance. Conclusions: The mcr-5.1 and mcr-3 colistin resistance gene variants were present in widely dispersed water sources in regions of the Western Cape. The mcr genes were only detected in water sampled downstream of and alongside communities, suggesting that their presence is driven by human influence/contamination. This is the first documentation of mcr-3 and mcr-5 gene variants in any setting in South Africa. Spill-over of these genes to communities could result in horizontal gene transfer to pathogenic bacteria, exacerbating the challenge of controlling multidrug resistant GNB infections.https://aricjournal.biomedcentral.com/articles/10.1186/s13756-021-00963-2Publisher's versio

Antimicrobial susceptibility patterns of <I>Escherichia coli </I>strains isolated from urine samples in South Africa from 2007 - 2011

Geneeskunde en GesondheidswetenskappeGeneeskundige MikrobiologiePlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]

Distribution and diversity of wildlife in northern Kenya in relation to livestock and permanent water points

Arid rangelands host a variety of drought-tolerant wildlife species, many of them requiring conservation efforts for the survival of their populations. The development of drinking water sources for people and livestock forms one of the main development interventions in these rangelands. However, the impact of availability of permanent drinking water on wildlife remains unknown. In this study we analyzed the distribution of wildlife and livestock in northern Kenya in relation to distance to permanent water. Livestock were concentrated in areas close to permanent water, while wildlife were frequently farther away from water; their distributions were inversely correlated. In addition, wildlife assemblages were more diverse farther from water. These results suggest that livestock and human activities related to water points negatively affect the distribution of wildlif