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Antimicrobial susceptibility profile of selected bacteraemic pathogens from private institutions in South Africa


Adrian Brink
Johan Moolman
Mark Cruz da Silva
Maria Botha
National Antibiotic Surveillance Forum

Abstract

Objectives. The National Antimicrobial Surveillance Forum is a continuous  surveillance organisation comprising all academic/ public and private   sector  laboratories in South Africa.

Methods. The antibiotic susceptibility of blood culture isolates of  Escherichia  coli, Klebsiella pneumoniae, Enterobacter species,   Pseudomonas aeruginosa, Acinetobacter baumannii and Staphylococcus  aureus from patients in private hospitals in five major centres were  investigated. Antimicrobial susceptibility tests were performed by 12  participating laboratories  according to the Clinical and Laboratory Standards Institute (CLSI)  guidelines. Extended-spectrum 13-lactamase (ESBL)  production was  determined in selected species of Enterobacteriaceae  irrespective of source.

Results. The overall prevalence of ampicillin resistance in blood culture isolates of E. coli (N = 471) was 84%, and 20% were resistant to the  fluoroquinolones. Considerable geographical differences were noted   between the centres with regard to the K. pneumoniae (N = 636) resistance rates for ceftriaxone and/ or cefotaxime (39- 87%). The most active   agents in the Enterobacter spp. (N = 244) were imipenem/meropenem, ertapenem, ciprofloxacin, levofloxacin and cefepime, with 100%,94%, 88%, 87% and 80% susceptibility, respectively. Carbapenem resistance in P. aeruginosa (N = 382) varied between 42% and 45%, and in the case of A. baumannii (N= 190) resistance varied between 32% and 33% for   meropenem and imipenem respectively. The nationwide incidence of  oxacillin resistance in S. aureus (N = 629) was 36%. Overall, the  prevalence of ESBL production among all isolates of K. pneumoniae was 26% (N = 7 514), while in Enterobacter spp. it was 12% (N = 4 031) and in E. coli 5% (N = 28 412).

Conclusions. The data highlight the widespread problem of antibiotic  resistance among important bacteraemic pathogens in private institutions in South Africa. Continued surveillance is vital to guide appropriate  empirical therapy for invasive infections.


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eISSN: 2078-5135
print ISSN: 0256-9574