Multiple Locus Variable number of tandem repeat Analysis : a molecular genotyping tool for Paenibacillus larvae

American Foulbrood, caused by Paenibacillus larvae, is the most severe bacterial disease of honey bees (Apis mellifera). To perform genotyping of P.larvae in an epidemiological context, there is a need of a fast and cheap method with a high resolution. Here, we propose Multiple Locus Variable number of tandem repeat Analysis (MLVA). MLVA has been used for typing a collection of 209 P.larvae strains from which 23 different MLVA types could be identified. Moreover, the developed methodology not only permits the identification of the four Enterobacterial Repetitive Intergenic Consensus (ERIC) genotypes, but allows also a discriminatory subdivision of the most dominant ERIC type I and ERIC type II genotypes. A biogeographical study has been conducted showing a significant correlation between MLVA genotype and the geographical region where it was isolated

Campylobacter jejuniの菌株識別法の確立と殺菌剤への耐性獲得に関する研究

東京海洋大学博士学位論文 平成27年度(2015) 応用生命科学 課程博士甲第390号指導教員: 木村　凡全文公表年月日: 2018-07-09東京海洋大学201

Food processing as a risk factor for antimicrobial resistance spread along the food chain

Documento post-printFarms and food industries rely to a large extent on the use ofbiocides as disinfectants and other antimicrobial agents andpreservatives with antimicrobial properties in order to providefood of high microbiological quality and safe for consumers.However, in the last decades it has become apparent that long-term sub-lethal exposure to these antimicrobial agents canexert a selective pressure leading to the emergence and spreadof microbial strains with a reduced susceptibility to the usedantimicrobials, which can persistently colonize food-processing environments and recurrently contaminate food. Inaddition, it may induce resistance to unrelated and clinicallyrelevant antibiotics, in a phenomenon known as cross-resistance. This review aims to provide insights on howantimicrobial resistance emergence and spread can beaffected by certain food processing activities and to discussrecent research focused on different pathways through whichbiocides and other antimicrobials could co-select for bacteriaresistant to clinically relevant antibiotics.S

Development of molecular typing method and investigation of biocide adaptation in Campylobacter jejuni

東京海洋大学博士学位論文 平成27年度(2015) 応用生命科学 課程博士甲第390号指導教員: 木村　凡全文公表年月日: 2018-07-0

Development of Multiple-Locus Variable-Number Tandem-Repeat Analysis for Molecular Subtyping of Campylobacter jejuni by Using Capillary Electrophoresis

ABSTRACT Campylobacter jejuni is a common cause of the frequently reported food-borne diseases in developed and developing nations. This study describes the development of multiple-locus variable-number tandem-repeat (VNTR) analysis (MLVA) using capillary electrophoresis as a novel typing method for microbial source tracking and epidemiological investigation of C. jejuni . Among 36 tandem repeat loci detected by the Tandem Repeat Finder program, 7 VNTR loci were selected and used for characterizing 60 isolates recovered from chicken meat samples from retail shops, samples from chicken meat processing factory, and stool samples. The discrimination ability of MLVA was compared with that of multilocus sequence typing (MLST). MLVA (diversity index of 0.97 with 31 MLVA types) provided slightly higher discrimination than MLST (diversity index of 0.95 with 25 MLST types). The overall concordance between MLVA and MLST was estimated at 63% by adjusted Rand coefficient. MLVA predicted MLST type better than MLST predicted MLVA type, as reflected by Wallace coefficient (Wallace coefficient for MLVA to MLST versus MLST to MLVA, 86% versus 51%). MLVA is a useful tool and can be used for effective monitoring of C. jejuni and investigation of epidemics caused by C. jejuni . </jats:p