Characterization of Francisella species isolated from the cooling water of an air conditioning system

Braz J Microbiol. 2015 Jul 1;46(3):921-7. doi: 10.1590/S1517-838246320140465. eCollection 2015 Jul-Sep.

Abstract

Strains of Francisella spp. were isolated from cooling water from an air conditioning system in Guangzhou, China. These strains are Gram negative, coccobacilli, non-motile, oxidase negative, catalase negative, esterase and lipid esterase positive. In addition, these bacteria grow on cysteine-supplemented media at 20 °C to 40 °C with an optimal growth temperature of 30 °C. Analysis of 16S rRNA gene sequences revealed that these strains belong to the genus Francisella. Biochemical tests and phylogenetic and BLAST analyses of 16S rRNA, rpoB and sdhA genes indicated that one strain was very similar to Francisella philomiragia and that the other strains were identical or highly similar to the Francisella guangzhouensis sp. nov. strain 08HL01032 we previously described. Biochemical and molecular characteristics of these strains demonstrated that multiple Francisella species exist in air conditioning systems.

Keywords: Francisella; air conditioning; water.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Conditioning*
  • Bacterial Proteins / genetics*
  • Base Sequence
  • China
  • DNA, Bacterial / genetics
  • DNA, Ribosomal / genetics
  • DNA-Directed RNA Polymerases / genetics*
  • Flavoproteins / genetics*
  • Francisella* / classification
  • Francisella* / genetics
  • Francisella* / isolation & purification
  • Molecular Sequence Data
  • Molecular Typing
  • Phylogeny
  • RNA, Ribosomal, 16S / genetics
  • Sequence Analysis, DNA
  • Water Microbiology*

Substances

  • Bacterial Proteins
  • DNA, Bacterial
  • DNA, Ribosomal
  • Flavoproteins
  • RNA, Ribosomal, 16S
  • SdhA protein, Bacteria
  • DNA-Directed RNA Polymerases
  • RNA polymerase alpha subunit