title: Application of multilocus sequence analysis for molecular characterization of enterococci with virulence factors recovered from a tropical recreational beach.
abstract: Partial gene sequences of phenylalanyl-tRNA synthase alpha subunit (pheS) and RNA polymerase alpha subunit (rpoA) were evaluated for species delineation and detection of recombination among enterococci populations recovered from a bathing beach impacted by low tide river flow. At inter-species level, a maximum similarity of 86.5% and 94.8% was observed among the enterococci pheS and rpoA sequence, respectively. A superimposed plot of delimited pairwise similarity values obtained for 266 pair-wise observations revealed that while there was a harmony between species identity obtained from both genes, pheS was more discriminatory than rpoA. The difference was more pronounced for inter-species comparison. A number of putative recombination events between indigenous and non-indigenous strains was detected based on a library of aligned sequences. Virulence genes cyl, esp, gelE and asa were detected in 7, 22, 100 and 63%, respectively among river isolates but at lower proportion of 0, 20, 67 and 42%, respectively among beach water isolates. Random amplified polymorphic DNA profiling presented evidence suggesting low tide river as a source of fecal enterococci entering the recreation beach water. Multilocus sequence typing analysis of a number of Enterococcus faecalis isolates presented four sequence types, ST59, 117, 181 and 474. The presence of genetically diverse fecal enterococci with associated virulence traits and a background of recombination events in surface recreational water could present a potential public health risk.
authors: Asmat
authors: A
authors: Ahmad
authors: Ayokunle Christopher
authors: AC
authors: Dada
authors: Gires
authors: G
authors: Usup
mesh_terms: D015373:Bacterial Typing Techniques; D001493:Bathing Beaches; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000235:genetics*; D016983:Enterococcus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D008296:Malaysia; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000032:analysis / Q000235:genetics; D017422:Sequence Analysis, DNA; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D037521:Virulence Factors; D012321:DNA-Directed RNA Polymerases; C113275:RNA polymerase alpha subunit