Open AccessCharacterisation and pathogenicity of Pasteurella multocida capsular serogroup A isolates from Awassi sheep in Syria
Author(s) -
Hussam Al-haj Ali,
B. Al Balaa
Publication year - 2021
Publication title -
bulgarian journal of veterinary medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.211
H-Index - 10
eISSN - 1311-1477
pISSN - 1313-3543
DOI - 10.15547/bjvm.2299
Subject(s) - pasteurella multocida , awassi , biology , fowl cholera , microbiology and biotechnology , veterinary medicine , serotype , pasteurellosis , herd , virulence , flock , pathogenicity , breed , pasteurella , isolation (microbiology) , virology , bacteria , zoology , medicine , paleontology , biochemistry , genetics , gene
The aim of the present study was to evaluate the prevalence of serogroup A of Pasteurella multocida in Syrian Awassi sheep. Of 1630 samples collected from nasal swabs of healthy and pneumonic sheep (125 herds) and pneumonic sheep lungs, a total of 228 (13.9%) strains were isolated and identified as P. multocida subsp. multocida by phenotypic and biochemical characterisation. However, of them only 117 (51.3%) were identified as serogroup A of P. multocida when PCR assay with specific primers for serogroup A strains was applied. The highest rate of serogroup A isolation was from apparently healthy sheep (49.6%) with consideration that all lung isolates (23 isolates) belonged to serogroup A. Geographical and seasonal distribution showed that about 60% of positively isolated bacteria originated from Syrian desert (29 isolates) and central parts of semi-arid step zone (41 isolates). A significant increase (P≤0.05) in the rate of positive isolates was observed in winter as compared to spring. Pathogenicity tests of 10 isolates with 50 or 10 LD50 values showed that 5 isolates were able to induce symptoms of fowl cholera in challenge-exposed chickens indicating that migratory Awassi sheep might serve as a carrier for serogroup A of P. multocida and that ovine isolates may be virulent for local breed of chickens.