A basic study of Vibrio vulnificus infection: serotyping and drug sensitivity test of environment-derived strains and human clinical isolates

摘要

In attempt to elucidate the route and source of Vibrio vulnificus infection. serotyping and drug sensitivity tests of environment-derived strains and human clinical isolates were performed. 1) Serotyping of isolates from the two types of source were determined. Of environment-derived strains, 72.5% were classified into 18 types, and O7 was the most frequent type, accounting for 73.1%, and the second frequent type was O4, accounting for 6.1%. Of human clinical isolates, 87.1% were classified into eight types, and O4 was the most frequent, accounting for 73.5%, and O7 was the secondly most frequent, accounting for 12.9%. 2) Serotypes were investigated by regions. In eastern Japan, 69.2% were classified into 18 types, and O7 and O4 accounting for 44.6% and 5.7%, respectively. In western Japan, 64.8% were classified into eight types, and O7 was the most frequent, accounting for 20.4%, and secondly frequent type was O4, accounting for 11.1%. 3) Regarding the relationship between biotypes and serotypes, environment-derived biotype-I strains were widely distributed in the serotypes, but most biotype-I human clinical isolates were distributed in serotypes O1-O7, showing a difference between the two types of sources. However, many biotype-II strains from the two types of sources included in the serotype O7 group. 4) Drug sensitivity was compared based on MIC90 between strains from the two types of sources. Environment-derived strains were sensitive to ABPC, PIPC, CPZ, CTX, LMOX, MEPM, GM, EM, TC, DOXY, MINO, CP, NA and CPFX, but some strains were resistant to CER, CET, CTX, CMZ, KM and LCM. Human clinical isolates were sensitive to EM, TC, DOXY, MINO, CP, NA and CPFX, but some strains were resistant to ABPC, PIPC, CER, CET, CPZ, CTX, CMZ, LMOX, MEPM, KM, GM, AMK and LCM.