Isolation, Serovar Identification, and Antimicrobial Susceptibility of Avibacteriumparagallinarum from Chickens in China from 2019 to 2020.

Mengjiao Guo,Yantao Wu,Xiufang Chen,Hao Zhang,Donghui Liu,Xiaorong Zhang

doi:10.3390/vetsci9010027

Abstract

Infectious coryza is an acute infectious respiratory disease in chickens that is caused by Avibacterium paragallinarum (A. paragallinarum). Infectious coryza has major economic effects due to decreased egg production in growing birds and slowed growth in broilers. In this study, we isolated and identified 40 strains of A. paragallinarum from chickens that showed typical clinical signs of coryza in part of China from 2019 to 2020. Using a hemagglutination-inhibition test, 11 isolates were identified as serovar A, 10 isolates were identified as serovar B, and 19 isolates were identified as serovar C. Antimicrobial sensitivity tests showed that high minimum inhibitory concentration (MIC) values were encountered for compounds sulfamethoxine sodium and oxytetracycline hydrochloride. Especially, of the 40 A. paragallinarum isolates, 30% had an MIC value of compound sulfamethoxine sodium of 64 μg/mL, 10% of 128 μg/mL, and 15% of 256 μg/mL. For oxytetracycline hydrochloride, 85% of isolates showed MIC values of 64 μg/mL or more. Excitingly, the MIC values of β-lactamase (amoxicillin, ampicillin, and ceftiofur) were low, with 77.5%, 70%, and 92.5% of isolates having an MIC value of ≤1 μg/mL, respectively. Our results may provide a reference for the treatment of infectious coryza.

Highlights

Infectious coryza (IC) is an acute infectious respiratory disease in chickens caused by a bacterium of the Pasteurellaceae family, Avibacterium paragallinarum (A. paragallinarum) [1].The most prominent character of IC is acute inflammation of the upper respiratory tract, with facial swelling, nasal discharge, and conjunctivitis
The A. paragallinarum isolates displayed a wide variance in minimum inhibitory concentration (MIC) values for LS with a range from ≤0.0625 to 256 μg/mL and the same was observed for TAT, a macrolide antibiotic
Only one serotype was prevalent during an outbreak

Summary

Introduction

Infectious coryza (IC) is an acute infectious respiratory disease in chickens caused by a bacterium of the Pasteurellaceae family, Avibacterium paragallinarum (A. paragallinarum) [1].The most prominent character of IC is acute inflammation of the upper respiratory tract, with facial swelling, nasal discharge, and conjunctivitis. Infectious coryza (IC) is an acute infectious respiratory disease in chickens caused by a bacterium of the Pasteurellaceae family, Avibacterium paragallinarum (A. paragallinarum) [1]. Stress is an important factor to be considered in the IC occurrence. High mortality and airsacculitis are the important issues of IC in broilers [6]. IC has been relatively well controlled in poultry. It occurred in many countries, such as China, USA, Indonesia, Great Britain and India, in recent years [7,8,9,10,11]. The disease prevention measures to control IC need to be improved

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