Abstract:
Yersiniosis (Enteric diseases
– red mouth) is a septicemic infectocontagious
disease of salmonides, produced
by Yersinia ruckeri, young rainbow trout
being the most susceptible to infection. The
disease appears as an exogenous or
endogenous infection, influenced by
favouring factors. The infection sources are
represented by sick and asymptomatic
carrier fishes that eliminate Yersinia through
faeces, contaminating water and fodder. At
the beginning of the disease outbreak, which
is the subject of the present scientific paper,
sudden water warming (15-17ºC) in the
spring of 2008 was incriminated. The
bacteriological examination carried out on
the anterior kidney and heart blood from
trout suspected of yersiniosis had as result
the isolation of some Yersinia ruckeri
bacteriological strains, confirming the
suspected diagnosis, based on lesions (high
degree anaemia of oral mucosa and
branchia, haemorrhagia on tongue mucosa,
exophthalmia and ocular haemorrhagia).
The identification of the causative agent was
based on morphological aspects (gramnegative,
motile and rod-shaped) and
distinctive metabolic characters, tested by
using API galleries. Antibiogramas pointed
out the Y. ruckeri strain susceptibility to
Oxytetracicline, Flumequine, Trimethoprim
and Ceftiofur and a medium susceptibility to
Amoxicillin and Enrofloxacin.
