Multilocus Sequence Typing (MLST) for Characterization of Enterobacter cloacae

Abstract

Enterobacter cloacae is an important emerging pathogen, which sometime causes respiratory infection, surgical site infection, urinary infection, sepsis, and outbreaks at neonatal units. We have developed a multilocus sequence typing (MLST) scheme utilizing seven housekeeping genes and evaluated the performance in 101 clinical isolates. The MLST scheme yielded 83 sequence types (ST) including 78 novel STs found in the clinical isolates. These findings supported the robustness of the MLST scheme developed in this study.

Clonal distribution of multidrug-resistant Enterobacter cloacae

“…The discriminatory ability of the different loci, measured as the number of alleles obtained for each gene, varied from 17 (for rpoB and rplB) to 21 (for dnaA) ( Table 1). This result differs from that obtained by Miyoshi-Akiyama et al (2013), reporting the leuS and pyrG alleles as the most polymorphic ones. The result of the nucleotide diversity analysis within the sample, performed on alleles of each MLST gene, demonstrated significant diversity in accordance with the data from Miyoshi-Akiyama et al (2013) and Izdebski et al (2015).…”

“…A phylogenic tree was inferred by bootstrap phylogenetic inference using Molecular Evolutionary Genetics Analysis Version 6.0. software (MEGA6) (Tamura et al, 2013). These sequences were compared with 3 concatenated reference sequences (ST2, ST3, and ST9), corresponding to the 3 main clades of ST for E. cloacae isolates, as reported by Miyoshi-Akiyama et al (2013). Searches of the GenBank databases were carried out using the NCBI BLASTn option (www.ncbi.nlm.nih.…”

“…By contrast, multilocus sequence typing (MLST) provides interlaboratory comparison of epidemiological data. We have used here a recently described MLST scheme including 7 housekeeping genes (Miyoshi-Akiyama et al, 2013) in order to perform an epidemiological comparison of 50 multidrug-resistant E. cloacae. This study focuses on multidrug-resistant isolates and, in particular, those producing the NDM-1 or OXA-48 carbapenemases and the ESBL CTX-M-15.…”

Emerging Carbapenem-Resistant <i>Enterobacter cloacae</i> Producing OXA-48-, VIM- and IMP-Type-<i>β</i>-Lactamases in Eastern Cape Hospitals in South Africa

“…The MLST scheme performed in this study is a new scheme developed and published in 2013 [27] and we were not able to compare the sequence types (ST) obtained in this study to previous sequence types obtained for this organism in South Africa. Five isolates resulted in new sequence types as they have not been located on the database although allelic profiles were generated for all seven reference genes.…”

“…The screening of bla GES , bla IMP and bla VIM was done using conventional PCR (GStorm Thermal Cycler, Somerton Biotechnology Centre, UK and the Qiagen multiplex PCR kit, Qiagen, Germany) and the primers from previous publications [25] [26]. Multilocus sequencing (MLST) was performed on these isolates using previously published primers and conventional typing methods [27]. Conventional PCR was performed for each of the seven reference/house-keeping genes and the products were purified (Qiagen Purification kit; Qiagen, Germany) and sequenced (Inqaba Biotech, South Africa).…”