Analysis of Vibrio seventh pandemic island II and novel genomic islands in relation to attachment sequences among a wide variety of Vibrio cholerae strains

In this report, a wide variety of V. cholerae strains were analyzed for the structure and distribution of VSP‐II in relation to their attachment sequences. Of 188 V. cholerae strains analyzed, 81% (153/188) strains carried VSP‐II, of those, typical VSP‐II, and a short variant was found in 36% (55/153), and 63% (96/153), respectively. A novel VSP‐II was found in 2 V. cholerae non‐O1/non‐O139 strains. In addition to the typical 14‐bp attL, 6 new attL‐like sequences were identified. The 14‐bp attL was associated with VSP‐II in 91% (139/153), whereas, the remaining 6 types were found in 9.2% (14/153) of V. cholerae strains. Of note, 6 distinct types of the attL‐like sequence were found in the 7th pandemic wave 1 strains, however, only 1 or 2 types were found in the wave 2 or 3 strains. Interestingly, 86% (24/28) of V. cholerae 7th pandemic strains harboring a 13‐bp attL‐like sequence were devoid of VSP‐II. Six novel genomic islands (GIs) using 2 unique insertion sites to those of VSP‐II were identified in 11 V. cholerae strains in this study. Four of those shared similar gene clusters with VSP‐II, except integrase gene.
Source: Microbiology and Immunology - Category: Microbiology Authors: Tags: Original Article Source Type: research