Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 12 4 2020 07 31 273 280 EN Marziyeh Gholizadeh Tangestani Department of Microbiology and Parasitology, School of Medicine, Bushehr University of Medical Sciences, Bushehr, Iran AND The Persian Gulf Tropical Medicine Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran Jafar Alinezhad Department of Microbiology and Parasitology, School of Medicine, Bushehr University of Medical Sciences, Bushehr, Iran AND The Persian Gulf Tropical Medicine Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran Abdolmohammad Khajeian The Persian Gulf Tropical Medicine Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran Somayyeh Gharibi Department of Microbiology, School of Sciences, Kherad Institute of Higher Education, Bushehr, Iran Mohammad Ali Haghighi Department of Microbiology and Parasitology, School of Medicine, Bushehr University of Medical Sciences, Bushehr, Iran AND The Persian Gulf Tropical Medicine Research Center, The Persian Gulf Biomedical Sciences Research Institute, Bushehr University of Medical Sciences, Bushehr, Iran 2020 03 12 2020 07 08 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. https://ijm.tums.ac.ir/index.php/ijm/article/view/2525 https://ijm.tums.ac.ir/index.php/ijm/article/download/2525/1252