Predominance of Klebsiella pneumoniaeST14 carrying CTX-M-15 causing neonatal sepsis in Tanzania

Abstract

BackgroundKlebsiella pneumoniae strains expressing ESBLs are a predominant cause of hospital acquired infections. Here we describe the molecular epidemiology of these isolates in a tertiary hospital in Tanzania, as potential pathogens for neonatal infections.MethodsBetween April 2009 and March 2010 all Klebsiella pneumoniae isolates with phenotypic expression Extended Spectrum Beta Lactamase (ESBL) were collected and characterized. Identification was done using in house biochemical tests in case of ambiguous results confirmation was done using API 20E. Susceptibility testing was determined using the disc diffusion method followed by specific PCR and sequencing to determine ESBL genes. Phylogenetic analysis, Pulse field gel electrophoresis (PFGE) and Multi-Locus sequence typing (MLST) to PFGE clusters representative isolates were performed to determine clones of the isolates. Conjugation and hybridization were performed to determine the location of blaCTX-M-15 gene.ResultsA total of 92 non- repetitive ESBL producing K. pneumoniae representing 50.3% of Klebsiella pneumoniae isolates were characterized. These isolates were from blood 61 (66%), wound swab 13 (14%), urine 12 (13%) and pus 6 (7%) were analyzed. Most blood culture strains originated from neonatal unit 39/61(64%) and 22 (36%) of the blood culture isolates were from neonatal ICU. All isolates were resistant to gentamicin and 54% were resistant to ciprofloxacin. Using a similarity index of 80%, the isolates were assigned to thirteen clusters based on PFGE patterns and contained sub-clusters with identical strains indicating clonal outbreaks. Cluster X5, X7 and X8, and X9 were grouped into ST48, ST14 and ST348 respectively. Based on gyrA PCR- RFLP phylogenetic analysis all isolates were grouped as KpI. The predominant ESBL allele detected was blaCTX-M-15 which was found in 76% of isolates, followed by blaTEM-104 (19%), blaSHV-11 (3.2%) and blaTEM-176 (2%). The blaCTX-M-15 gene was located in multiple conjugative IncF plasmids ranging from 25 kb-485 kb in size.ConclusionThe high prevalence of blaCTX-M-15 observed among ESBL producing K. pneumoniae in Tanzania, is possibly due to the spread of a common IncFII 145 kb plasmid and of certain clones such as ST14 and ST48. Furthermore the 485 kb plasmid detected is the largest plasmid reported to carry blaCTX-M-15 todate.

Prevalence of ESBL-producing Enterobacteriaceae isolated from blood cultures in Mali

“…[20]. Also in Tanzania, in a study on neonatal sepsis, 50.3% of the K. pneumoniae were found to be ESBL producers [13]. Importantly, a much more recent study in India (2014) in a nephrourology teaching institute showed that among Enterobacteriaceae isolated from blood cultures, 39.6% were ESBL producers [21].…”

“…In Ethiopia (2009), E. coli was isolated from 18.7% of the cases (67/359) in clinical samples of both hospitalized and non-hospitalized patients, of which 35.8% (24/67) were ESBL producers [12]. In Tanzania (2009-2010), 50.3% (92/183) of K. pneumoniae strains isolated from blood cultures were ESBL producers; 5.5% (5/92) of them were from the community and 94.5% (87/92) from hospitals [13]. In Ghana (2007) and Mali (2003), ESBLs were produced, respectively, by 49.4% and 63.4% of Enterobacteriaceae isolated in community and hospital samples [14,15] [16].…”

Detection of High Prevalence of TEM/SHV/CTX-M Genes in ESBL Producing and Multidrug Resistant Klebsiella Pneumoniae and Klebsiella Oxytoca

“…showed that bla CTX-M 15 was localized on a plasmid of 25 to 485KB and that ST14 and ST48 clones carried also resistance genes to gentamicin and trimethoprim-sulfamethoxazole [56]. More recently, in a study in Central African Republic, Rafai et al showed that all ESBL producing Klebsiella pneumoniae isolated from surgical wounds, expressed bla CTX-M 15 and aac(6 H)-Ib-cr [58].…”

In vitro susceptibility of multi-drug resistant Pseudomonas aeruginosa and extended-spectrum β-lactamase–producing Klebsiella pneumoniae isolated from clinical specimens at Bugando Medical Centre, Tanzania to Piperacillin-Tazobactam

“…In Tanzania high mortality has been observed with infections associated with ESBL producing gram negative bacteria (Kayange et al, 2010). In our setting, high prevalence of health care associated infections due to ESBL producing Klebsiella pneumoniae have been observed in surgical wards and neonatal units (Mshana et al, 2013). Pseudomonas spp also have been found to be common causes of wound infections in our setting (Mbunda et al, 2012).…”