Characteristics of virulence gen distribution and antibiotic resistance of non-O1/O139 Vibrio cholera

Objective To explore the distribution of virulence genes and drug resistance of non-O1/O139Vibrio (V.) cholerae. Methods Non-O1/O139V.cholerae strains and the related patient records were collected from the intestinal clinic of Beijing Friendship Hospital from 2014 to 2015. The susceptibility of V.cholerae strain to 15 antibiotics was tested with microbroth dilution method, and virulence genes were detected by using polymerase chain reaction (PCR). Results The drug susceptibility test showed that the resistant rate of 35 strains of non-O1/O139V.cholerae to trimethoprim-sulfamethoxazole was highest (40.0%), followed by the resistant rates to chloramphenicol (28.5%) and sulfisoxazole (22.6%). The strains were sensitive to amoxicillin/clavulanate, ceftriaxone, cefoxitin, cefepime and imipenem. PCR detection of virulence genes showed that all strains were positive for hlyA and ompU gene, and the positive rates of hapA, rtxA, T6SS, T3SS and nanH were 97.1%, 91.4%, 94.3%-97.1%, 80.0%-85.7%, 62.9%, respectively. The predominant virulence pattern was hlyA-rtxA-hapA-ompU-nanH-vasA-vasK-vasH-vcsC-vcsV-vcsN-vspD (40.0%). Conclusion The high antibiotic resistance and virulence gene polymorphism suggested that it is important to strengthen the surveillance for the genetic variation and drug resistance of the clinical isolates of non-O1/O139 V.cholerae.