Emergence of OXA-48 and OXA-181 carbapenemases among Enterobacteriaceae in South Africa and evidence of in vivo selection of colistin resistance as a consequence of selective decontamination of the gastrointestinal tract.

This study reports on the emergence of OXA-48-like carbapenemases among isolates of Enterobacteriaceae in South Africa. In addition, the emergence during therapy of a colistin-resistant OXA-181-producing Klebsiella pneumoniae isolate was documented following selective digestive tract decontamination with oral colistin, which is therefore strongly discouraged.

The spread of carbapenem-resistant Enterobacteriaceae in South Africa: risk factors for acquisition and prevention.

New, effective antibiotics are only likely to become available in 15 - 20 years. To prevent deaths from untreatable Gram-negative infections in South Africa, the rights of any doctor, whether in general or in hospital practice, to indiscriminately prescribe whatever antibiotic they wish, and in whatever fashion, must be challenged. Furthermore, although prevention of the emergence and subsequent spread of carbapenem-resistant Enterobacteriaceae (CRE) has focused on acute and chronic care facilities and inter alia on antibiotic exposure in these institutions, CRE may soon become an issue within entire communities, highlighting a role for public health authorities in CRE prevention efforts.

In vitro activity of tigecycline against clinical isolates of carbapenem resistant Acinetobacter baumannii complex in Pretoria, South Africa.

BACKGROUND: The presence of multi-drug resistant Acinetobacter baumannii raises a big therapeutic challenge in our hospital. Tigecycline, a new glycylcycline with expanded broad spectrum of activity against multi-drug resistant organisms was recently licensed in South Africa. AIM: The aim of this study was to evaluate the in vitro activity of tigecycline against carbapenem resistant A. baumannii complex. METHODS: Consecutive clinical isolates of carbapenem resistant A. baumannii complex were collected between February and July 2010. Species identification and susceptibility testing was performed by Vitek-2 colorimetric compact system with Advanced Expert System (AES). Strains were tested for carbapenemase production by the modified Hodge test, according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. RESULTS: A total of 232 carbapenem resistant clinical isolates of A. baumannii complex were collected over the six months study period; 217 (93.5%) of these were modified Hodge test positive. All isolates were susceptible to colistin and 174 (78%) susceptible to amikacin whilst 20 (9%) were susceptible to ciprofloxacin. For tigecycline 169 (75.8%) were fully susceptible, 37 (16.6%) intermediately resistant and only 17 (7.6%) were fully resistant. None of the carbapenem resistant isolates were susceptible to ampicillin, amoxicillin/clavullanic acid, piperacillin/tazobactam, cefuroxime, cefuroxime axetil, cefoxitin, cefepime or nitrofurantoin. CONCLUSION: All carbapenem resistant isolates were found to be fully susceptible to colistin; amikacin and tigecycline susceptibility was 78% and 76% respectively. Treatment options for infections due to carbapenem and multi-drug resistant A. baumannii organisms are limited and hence tigecycline and amikacin may be considered. The properties of tigecycline i.e. stability, safety, low toxicity, non cross-resistance with other antibiotics and its efficacy against multi-drug resistant A. baumannii isolates make it a good choice. However, ongoing monitoring of A. baumannii susceptibility to tigecycline is needed.

Emergence of New Delhi metallo-beta-lactamase (NDM-1) and Klebsiella pneumoniae carbapenemase (KPC-2) in South Africa.

This report documents emergence of New Delhi metallo-beta-lactamase (NDM-1) and Klebsiella pneumoniae carbapenemase (KPC-2) in K. pneumoniae and Enterobacter cloacae in South Africa. NDM-1 producers have not been described in South Africa, and this is the first instance that KPC producers have been identified in Africa. The two patients infected with these carbapenemase-producing bacteria demised.