Periódicos Brasileiros em Medicina Veterinária e Zootecnia

p. 921-927

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

Gu, QuanLi, XundeQu, PinghuaHou, ShuipingLi, JuntaoAtwill, Edward RChen, Shouyi

<p>Strains of <italic>Francisella</italic> 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 <italic>Francisella</italic>. Biochemical tests and phylogenetic and BLAST analyses of 16S rRNA, <italic>rpoB</italic> and <italic>sdhA</italic> genes indicated that one strain was very similar to <italic>Francisella philomiragia</italic> and that the other strains were identical or highly similar to the <italic>Francisella guangzhouensis</italic> sp. nov. strain 08HL01032 we previously described. Biochemical and molecular characteristics of these strains demonstrated that multiple <italic>Francisella</italic> species exist in air conditioning systems.</p>.(AU)

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