Authors: B Kullin T Brock N Rajabally F Anwar G Vedantam S Reid V Abratt
Publish Date: 2016/07/27
Volume: 35, Issue: 10, Pages: 1709-1718
Abstract
The C difficile infection rate in South Africa is concerning Many strains previously isolated from diarrhetic patients at Groote Schuur Hospital were ribotype 017 This study further characterised these strains with respect to their clonal relationships antibiotic susceptibility toxin production and various attributes impacting on pathogen colonisation Multilocus variablenumber tandemrepeat analysis MLVA was used to characterise all C difficile isolates Antibiotic susceptibility was determined by Etest and PCRbased analysis of the ermB gyrA and gyrB genes Autoaggregation of cells was measured in broth and biofilm formation observed in 24well plates Toxins were measured using the Wampole C DIFF TOX A/B II kit Most isolates belonged to the ribotype 017 group Identical MLVA types occurred in different wards over time and several patients were infected with identical strains All isolates were susceptible to vancomycin and metronidazole but some ribotype 017 isolates showed reduced metronidazole susceptibility ≥2 mg l−1 Sixtynine percent of ribotype 017 isolates were resistant to moxifloxacin and 94 to erythromycin compared to 0 and 17 resistance respectively in nonribotype 017 isolates The ermB gene and mutations in the gyrA and/or gyrB genes were linked to erythromycin and moxifloxacin resistance respectively Ribotype 017 isolates autoaggregated more strongly than other isolates and produced lower levels of the TcdB toxin than a reference strain Certain strains produced strong biofilms Patienttopatient transfer and unique infection events could cause the predominance of ribotype 017 strains in the cohort Multidrug resistant strains are a potential reservoir for future infectionsThis study was funded by the National Research Foundation of South Africa and the South African Medical Research Council B Kullin acknowledges the Claude Leon Foundation and the Carnegie Corporation of New York for Postdoctoral Fellowships and an assistance grant from the European Society of Clinical Microbiology and Infectious Diseases to attend the ANAEROBE 2014 Congress T Brock was supported by the Equity Development Programme UCT
Keywords: