Clonal analysis of Yersinia ruckeri based on biotypes, serotypes and outer membrane protein‐types

Abstract

The biotypes, serotypes and outer membrane protein-types (OMP-types) of 135 isolates of Yersinia ruckeri were analysed in an attempt to identify elonal groups and to examine in further detail the relationships between isolates from wide geographie areas. Eaeh isolate eould be assigned to one of two biotypes (1 and 2), one of five 0-serotypes (01, 02, 05, 06 and 07), and one of live OMP-types (1-5). Outer membrane protein analysis was able lo differentiate between isolates within a given serotype. Thus, serotype 01 isolates eonsisted of OMP-types 1, 2, 3 and 4, serotype 02, 05 and 06 isolates eonsisted of OMPtypes 1 and 2, and serotype 07 isolates eonsisted of OMP-types 1 and 5. Whereas OMPtypes 3 and 4 were assoeiated only with serotype 01, and OMP-type 5 was associated only with serotype 07, OMP-types 1 and 2 were assoeiated with serotypes 01, 02, 05, 06 and 07, and 01, 02, 05 and 06, respeetively. When biotype was taken into consideration, serotype 01 isolates of OMP-types 1 and 2 eould be sub-divided into four groups; serotype 01 isolates eould thus be sub-divided into six elona! groups. Two of these elonal groups were responsible for the majority of the disease outbreaks in Europe and represented 79% of the European isolates. A combination of biotype, serotype and OMP-type analysis was demonstrated to be useful in epidemiologieal studies of Y. ruckeri.

Yersinia ruckeri biotype 2 isolates from mainland Europe and the UK likely represent different clonal groups

“…In general, the highly clonal nature of Yersinia ruckeri isolates responsible for ERM in rainbow trout, as shown by this and other studies (Pyle et al 1987, Davies 1991a, Garcia et al 1998, is similar to that observed for other significant bacterial pathogens of farmed fish (Grayson et al 1999, Eyngor et al 2004, Reid et al 2004, Nash et al 2006. Although the isolates analysed were geographically biased and, in many cases, nonrandomly selected (e.g.…”

“…The majority of ERM-causing serotype O1 isolates in the UK has always been biotype 2 (Davies & Frerichs 1989, present study). In contrast, Danish biotype 2 serotype O1 isolates shared the same pulsotype (pt35) as the serotype O1 biotype 1 clone (clonal group 5), the latter being responsible for the majority of disease outbreaks since the first emergence of ERM in Denmark and elsewhere in mainland Europe (Davies 1991a). It is therefore likely that the Danish biotype 2 isolates have independently emerged out of the existing mainland European Y. ruckeri population, rather than representing cross-border transfer of UK biotype 2 isolates into or from Denmark.…”

“…Yersinia ruckeri is a highly clonal and biochemically homogeneous species (Schill et al 1984, Stevenson & Airdrie 1984, Daly et al 1986, Pyle et al 1987, Davies 1991a, Garcia et al 1998. A single serogroup (serovar 1 or heat-stable O1 antigen) is responsible for most outbreaks in rainbow trout farmed worldwide (Stevenson & Airdrie 1984, Davies 1991a).…”

“…A single serogroup (serovar 1 or heat-stable O1 antigen) is responsible for most outbreaks in rainbow trout farmed worldwide (Stevenson & Airdrie 1984, Davies 1991a). This can be further subdivided by biotype and outer membrane protein (OMP) type into 6 major clonal groups.…”

Ribotyping and plasmid profiling of Yersinia ruckeri

“…A possible relation between motility and virulence is at present unknown and needs further investigation. Davies (1991b) also found different clonal groups within serotype 0 1 according to biotypes, serotypes and OMP profiles. This author reported that two of these clonal groups were predominant, one in the UK and the other in the rest of Europe.…”