Outbreaks of multidrug-resistant Acinetobacter baumannii strains in a Kenyan teaching hospital

Abstract

Acinetobacter baumannii is a serious nosocomial pathogen with a high propensity to cause outbreaks. Whilst outbreaks of A. baumannii have been reported in many regions worldwide, few data are available from East Africa. In this study, 25 A.baumannii isolates derived from a single institution located in Nairobi, Kenya, between September 2010 and September 2011 were examined. Antimicrobial susceptibility testing was performed by the disk diffusion method and the relatedness among the isolates was examined by pulsed-field gel electrophoresis, repetitive sequence-based PCR (rep-PCR) and multilocus sequence typing. The examined isolates clustered into three distinct groups. The most prevalent sequence type (ST) was ST110 (17 isolates), followed by ST92 (5 isolates) and ST109 (3 isolates). All isolates exhibited resistance to cefepime, ceftazidime, ticarcillin/clavulanic acid, cefotaxime/clavulanic acid, piperacillin/tazobactam, cefoxitin, ciprofloxacin, gentamicin, nitrofurantoin, fosfomycin trometamol, trimethoprim/sulfamethoxazole, amikacin, meropenem and imipenem, with the exception of four isolates. Two isolates belonging to ST92 and two isolates belonging to ST109 were susceptible to amikacin; one of these amikacin-susceptible ST109 isolates was also susceptible to meropenem and imipenem. All isolates were positive for OXA 51-like and all carbapenem-resistant isolates were OXA-23 positive.

Molecular characterization of Extended Spectrum Beta Lactamases (ESBLs) produced by clinical isolates of Acinetobacter baumannii in Saudi Arabia

“…Yet, MLST provides a quick and easy method to study the epidemiology of ESBL-producing bacteria and to monitor the international emergence of multidrug resistant bacteria. Consistent with other studies that used MLST in the epidemiologic characterization of clinically important bacterial pathogens such as A.baumannii, Streptococcus pneumoniae, Streptococcus pyogenes, Neisseria meningitidis, Campylobacter jejuni, Staphylococcus aureus, Enterococcus faecium, Haemophilus influenza, and Vibrio cholera, our study has detected different allelic diversity (STs) which belongs to clonal complex (CC)2 which is globally distributed in Europe, Asia, Africa, Australia, USA, South America [19,[27][28][29].…”

The Molecular Epidemiology and Genetic Environment of Carbapenemases Detected in Africa

“…Two new resistance gene cassettes (arr-2-crnlA5 and aadBaadA2-crnlA6-aadA15) were also discovered with ArmA, aph(3¢)-vl, and aac(6¢)-lh on class 1 integrons (Supplementary Table S1) in CRAB isolates. 38 …”

Species identification within Acinetobacter calcoaceticus–baumannii complex using MALDI-TOF MS

“…The MLST typed A. baumanni isolates included sixteen isolates of sequence type (ST)110, four isolates of ST92 and three isolates of ST109 (Huber et al, 2014). In addition to this, four isolates of from the Arabian peninsula were added to the study, including one isolate from Saudi Arabia of the ST195 and one of ST436, respectively, plus one isolate of ST208 from Kuwait and one of ST229 from Qatar (Zowawi et al, 2015).…”

“…The Kenyan strains and the strains from the Arabian peninsula were collected and MLST typed as previously described (Huber et al, 2014;Zowawi et al, 2015). MLST typing has been performed according to the Oxford scheme for all isolates (http://pubmlst.org/abaumannii/).…”