ISOLATION AND CHARACTERIZATION OF YERSINIA SPECIES FROM CHICKENS AROUND ZAR1A
ISOLATION AND CHARACTERIZATION OF YERSINIA SPECIES FROM CHICKENS AROUND ZAR1A
No Thumbnail Available
Date
2014-09-08
Authors
EVELYN, NNENN1A NWOSUH
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
The study was conducted to determine the prevalence of
Yersinia spp. infection in chickens kept under different
management systems in Zaria area using cultural and serologic
means. All isolates were fully characterized. In addition,
experimental studies were conducted in chickens exposed to
Y. enterocolitica by the oral and intravenous routes.
Five (0.63%) strains of Y. enterocolitica were i s o l a t ed
from 800 cloacal swabs of chickens kept under the extensive
( free-range ) , semi-intensive and intensive management systems.
All samples were enriched in 0.67m phosphate buffered saline,
pH 7.6 for 3 weeks and plated on desoxycholate citrate agar and
MacConkey agar. All 5 s t r a i n s came from chickens kept under the
extensive management system ana were of serotype 0:12,25,
biotype 3 and ptoagetype Xz.
Biochemically, all reactions of the isolates were typical
for Y. enterocolitica but for the utilization of citrate by all
and Voges-Proskauer positive results at 370 C for two isolates.
Only as train (ZM12) was positive for all 4 virulence
markets assayed for, namely, calcium dependency at 370 C,
autoagglutination at 37 C, invasiveness in guinea-pig eye
(sereny t e s t ) and production of heat-stable (ST) enterotoxin as
detected by the infant mouse system (IMS). The IMS was found
to be more sensitive in detecting ST enterotoxin with 4 of 5
strains being positive, than the rabbit ileal loop system where
filtrates of supernatant of the 5 strains were negative.
In vitro activities of the antimicrobial agents tested
by the disc and agar dilution metnods demonstrated that neomycin,
kanamycin, gentamycin, nalidixic acid, colistin sulphate and
sulphamethoxazole-Trimethoprim (SXT) were most effective against
Y. enterocolitica strains from chickens.
An overall antibody prevalence of 1.9% was detected against
serotypes 0:3, 0:5, 27, 0:8, 0:9 and 0:12,26 screened for in 800
serum samples obtained from the extensive and intensive systems
of management. All sere, were negative for agglutinins against
serotypes 0:5,27, 0:8 and 0:12,26 but 4(0.5%) and 11(1.4%) were
positive for antibodies to serotypes 0:3 and 0:9 respectively.
9
Experimental inoculation, by the oral route, of 10 to
101 1 cells of 3 serotypes of Y. enterocolitica into day-old
broiler chicks did not cause any overt clinical signs. Weight
gain in infected chickens was not affected over the study period.
Colonization of the gut of infected chickens was minimal with
Y. enterocolitica shed in faeces for only a few days.
Administration of 10% NaHCO3 had no significant effect on colonization
of the gut of chickens by Y. enterocolitica.
Of public health significance was the detection of
Y. enterocolitica in the liver, spleen, heart and bile of some
experimentally exposed but apparently healthy chickens,
10
Three-week old chicks inoculated with 1.0x10 and
2.1x10 cells of Y. enterocolitica by the intravenous
route showed initial clinical signs like diarrhoea, depression
and loss of appetite but recovery was completed within 24hrs
in most chicks.
It was concluded that the rather high environmental
temperature in Nigeria, a tropical country coupled with the
relatively high normal body temperature of chickens may be
responsible, in part, for the low prevalence of Y. enterocolitica
infection detected in the present study. This is because the
organism has affinity for low temperature.
Description
A thesis submitted to Ahmadu Bello University, Zaria
in partial fulfilment for the degree of MASTER OF
SCIENCE
Department of Veterinary Public Health and
Preventive Medicine
Ahmadu Bello University, Zaria
Keywords
ISOLATION,, CHARACTERIZATION,, YERSINIA,, SPECIES,, CHICKENS,, AROUND ZAR1A