In 2017, the Turlock branch of the California Animal Health & Food Safety laboratory system received a significant increase in infectious coryza (IC) necropsy cases, with a total of 54 submissions originating from commercial broilers (n = 40), commercial layers (n = 11), and backyard chickens (n = 3). Layer flocks positive for IC were distributed within the adjacent counties of Merced and Stanislaus, while broiler flocks were concentrated within Merced County. The backyard flocks were located in Alameda and Sacramento counties. The clinical and pathologic presentation was consistent with IC, although septicemic lesions were also noticed. Avibacterium paragallinarum was isolated and identified by PCR from the respiratory tract as well as from extrarespiratory sites. Polymicrobial infections involving other viral (infectious bronchitis virus, infectious bursal disease virus) and bacterial (Mycoplasma spp., Escherichia coli, Ornithobacterium rhinotracheale, Gallibacterium anatis biovar haemolytica) agents were commonly reported. Thirteen selected Av. paragallinarum isolates were successfully characterized as serovar C (Page scheme) and serovar C2 (Kume scheme). They shared a unique enterobacterial repetitive intergenic consensus (ERIC) PCR, differing from the four reference strains, and showed consistent high minimum inhibitory concentration values for tetracycline, suggesting a common origin from a single clone. Based on these results, high biosecurity standards and proper immunization of susceptible, multi-age flocks should always be implemented and adjusted as needed. The importance of backyard flocks should not be underestimated due to their unique epidemiologic role.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 63 • No. 3