Prevalence, persistence and antimicrobial resistance of Campylobacter spp. from eggs and laying hens housed in five commercial housing systems.

Authors: NOVOA RAMA, ESTEFANIA - University Of Georgia; BAILEY, MATTHEW - University Of Georgia; Jones, Deana; Gast, Richard; ANDERSON, KEN - North Carolina State University; BRAR, JAGPINDER - Purdue University; TAYLOR, RHONDA - Purdue University; OLIVER, HALEY - Purdue University; SINGH, MANPREET - University Of Georgia

Submitted to: Foodborne Pathogens and Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/2018
Publication Date: 8/1/2018
Citation: Novoa Rama, E., Bailey, M., Jones, D.R., Gast, R.K., Anderson, K., Brar, J., Taylor, R., Oliver, H.F., Singh, M. 2018. Prevalence, persistence and antimicrobial resistance of Campylobacter spp. from eggs and laying hens housed in five commercial housing systems. Foodborne Pathogens and Disease. 15:506-516.

Interpretive Summary: Husbandry practices for laying hens in commercial egg production is a topic of current social, economic, and regulatory interest. Consumer perceptions of hen welfare in conventional cage systems have led to a higher demand for cage-free eggs. The aim of this study was to assess the impact of different housing systems on the prevalence, persistence, and antimicrobial resistance of Campylobacter from laying hens and shell eggs. Samples were collected over a 10-month period from hens in several different housing systems maintained under simulated commercial conditions. Campylobacter isolates were identified by serological, biochemical and molecular tests. Campylobacter prevalence ranged from 11% in enrichable cages to 20% in conventional cages, and was higher in fecal swabs from free range birds than from more intensive housing systems. More than 20 different genetic patters were identified among the 72 confirmed Campylobacter isolates, although most isolates were C. jejuni. Two-thirds of C. jejuni isolates displayed high levels of resistance to tetracycline. This study suggests that laying hen housing systems can impact Campylobacter shedding and that tetracycline resistance levels of this pathogen are of concern, reinforcing the importance of farm biosecurity practices.

Technical Abstract: Husbandry practices for laying hens in commercial egg production is a topic of interest from a social, economic, and regulatory standpoint. Animal welfare concerns regarding the use of conventional cages have arisen and consumer perceptions of hen welfare have led to a higher demand of cage-free eggs. The aim of this study was to assess impact of housing systems on prevalence, persistence, and antimicrobial resistance (AMR) of Campylobacter from laying hens and shell eggs. A total of 425 samples were collected over a 10-month period from the North Carolina Layer Performance and Management Test and Campylobacter isolates were identified by serological, biochemical and molecular tests. Genetic variability was evaluated using Pulsed-field Gel Electrophoresis (PFGE) and the AMR testing was performed. Prevalence of Campylobacter spp. ranged from 11.1% in the enrichable cages to 19.7% in the conventional systems (P>0.05). A greater prevalence of Campylobacter was found in the fecal swab samples from free-range birds as compared to that of birds housed in the more intensive housing systems (P>0.05). Overall, 72 isolates were confirmed as Campylobacter spp. by qPCR. More than 90% of the isolates (n=66) were identified as C. jejuni, followed by C. coli (n=6). C. jejuni isolates displayed high levels of resistance to tetracycline (67%). Genetic variability of Campylobacter was high, with more than 20 PFGE patterns identified. Pattern ‘a’ comprised 42% of isolates from all housing systems and was also the most persistent. This study suggests that housing systems of laying hens used for commercial shell egg production can impact the rate of Campylobacter shedding by layers. Isolation rates and tetracycline resistance levels of this pathogen are still of concern, stressing the need for well-implemented biosecurity measures on the farm.