Isolation and characterization of arcobacter butzleri from environmental samples and determination of their pathogenic gene expression under different physicochemical conditions

Abstract

Being transmitted through food and water, Arcobacter butzleri (A. butzleri) is known as an emerging pathogenic microorganism in humans. This Campylobacter-like organism can cause infertility, miscarriage, as well as gastrointestinal (GI) disorders in animals and even lead to gastroenteritis, bacteremia, endocarditis, and peritonitis in humans. To meet the research objectives, a total number of 384 samples were collected from the wastewater discharged by a poultry slaughterhouse (n = 238) and the Cheshmeh Kileh River (146) in the city of Tonekabon, northern Iran, during the four seasons of the year. Then, the samples were evaluated using culture techniques and phenotyping. In addition, the polymerase chain reaction (PCR) was applied to confirm A. butzleri via 16S ribosomal ribonucleic acid (rRNA) sequencing and pathogenic genes, i.e., tlyA, ciaB, and mviN. Afterwards, the effect of various environmental stresses on the isolates was evaluated. Finally, the reverse transcription (RT)-PCR was exploited to reflect on expression/lack of expression of the pathogenic genes at pre-/post-shock stages. Totally, 58 isolates were established as A. butzleri, which contained three pathogenic genes out of all three strains. The effect of various environmental stresses on tlyA, mviN, and ciaB expressions also demonstrated discontinued expression at pH levels of 5.0, 6.0, and 9.0; 5% sodium chloride (salt, NaCl) concentration; and 90 s ultraviolet (UV) light exposure time. In addition, the expressions of tlyA and ciaB stopped at 20 and 40ºC while no temperature affected the expression of mviN.