Identification of cholix toxin gene in Vibrio cholerae non-O1/non-O139 isolated from diarrhea patients in Bushehr, Iran

Abstract

Background and Objectives: Cholixin (cholix toxin) is a novel exotoxin in Vibrio cholerae identified as an elongation factor II specific ADP-ribosyltransferase which inhibits protein synthesis in the eukaryotic cell. Previous researches have suggested that cholixin probably is an important virulence factor in non-O1/non-O139 V. cholerae (NAG) serotypes that could be related to extra-intestinal rather than intestinal infections. This study was aimed to investigate the frequency and genetic diversity of colixin gene (chxA) in clinical V. cholerae NAG isolates.
 Materials and Methods: The presence of chxA gene in 44 clinical V. cholerae NAG isolates were screened using PCR through specific primers designed for the receptor-binding domain (RBD) of chxA gene. The five PCR products of chxA gene were sequenced.
 Results: This study showed that chxA gene presented in 19 V. cholerae NAG isolates. The sequences analysis of 5 out of 19 the partial chxA genes amplicon showed that 4 of them belonged to chxA I and the other one belonged to chxA II subtypes. Two distinct clusters were revealed for these isolates by phylogenic analysis, too.
 Conclusion: The chxA gene contained high frequency among V. cholerae NAG isolates in Bushehr, Iran. The polymorphism study on RBD of cholixin gene is suggested as an appropriate method for phylogenic characterization of the various chxA gene subtypes.

Duped by dumping syndrome: non-endemic Vibrio cholerae bacteremia in an immunocompetent host with gastric bypass surgery, a case report

“…Despite this, NOVC strains are associated with significant genetic diversity and may harbour other virulence factors acquired via horizontal gene transfer. The toxigenic potential of NOVC strains have been attributed to genes coding for type III and type VI secretion systems, enterotoxins, and hemagglutinin proteases [18, 19]. This isolate demonstrated genes coding for a type VI secretion system, associated with bacterial persistence [20], and an hlyA gene, coding for hemolysin, associated with gut colonization and immune evasion, and gastroenteritis in NOVC strains [18, 21].…”

Non-O1/Non-O139 Vibrio cholerae—An Underestimated Foodborne Pathogen? An Overview of Its Virulence Genes and Regulatory Systems Involved in Pathogenesis

“…The in vivo toxicity presented as liver damage and final death through mouse assay [107,117]. Tangestani et al, 2020, also confirmed the presence of cholix toxin in NOVC [17].…”

“…Bacteremia can also be caused by an orally acquired infection via the infiltration of NOVC in the bloodstream through the portal vein and intestinal lymphatic system [8][9][10]. Individual infection cases that could be clearly attributed to the consumption of contaminated seafood have been described in Spain [11], Italy [12], Portugal [13], India [14], Australia [15], the USA [16], and Iran [17]. Localized NOVC outbreaks have been reported in India and Thailand in the past [18][19][20][21][22][23].…”

Cell Death Signaling Pathway Induced by Cholix Toxin, a Cytotoxin and eEF2 ADP-Ribosyltransferase Produced by Vibrio cholerae

“…The cholix genes were found in V. cholerae strains isolated in various countries, such as Bangladesh [ 4 , 23 , 28 ], Germany [ 29 , 30 , 31 , 32 ], India [ 28 ], Iran [ 33 ], Kenya [ 34 ], Mexico [ 23 , 29 , 35 ], and the United States [ 23 ]. While the cholix gene was present in O1 serotype strains [ 4 , 23 ], some researchers proposed that the gene appears to be preferentially associated with NOVC strains, with higher prevalence in NOVC than O1/O139 V. cholerae strains [ 28 , 29 ].…”