Impacts of Poultry House Environment on Poultry Litter Bacterial Community Composition

Abstract

Viral and bacterial pathogens are a significant economic concern to the US broiler industry and the ecological epicenter for poultry pathogens is the mixture of bedding material, chicken excrement and feathers that comprises the litter of a poultry house. This study used high-throughput sequencing to assess the richness and diversity of poultry litter bacterial communities, and to look for connections between these communities and the environmental characteristics of a poultry house including its history of gangrenous dermatitis (GD). Cluster analysis of 16S rRNA gene sequences revealed differences in the distribution of bacterial phylotypes between Wet and Dry litter samples and between houses. Wet litter contained greater diversity with 90% of total bacterial abundance occurring within the top 214 OTU clusters. In contrast, only 50 clusters accounted for 90% of Dry litter bacterial abundance. The sixth largest OTU cluster across all samples classified as an Arcobacter sp., an emerging human pathogen, occurring in only the Wet litter samples of a house with a modern evaporative cooling system. Ironically, the primary pathogenic clostridial and staphylococcal species associated with GD were not found in any house; however, there were thirteen 16S rRNA gene phylotypes of mostly Gram-positive phyla that were unique to GD-affected houses and primarily occurred in Wet litter samples. Overall, the poultry house environment appeared to substantially impact the composition of litter bacterial communities and may play a key role in the emergence of food-borne pathogens.

Arcobacter

“…Other studies utilizing both PCR and culture confirmation have been able to identify Arcobacter in a large percentage of chicken intestines, though the rates of detection vary significantly between flocks . Arcobacter has also been identified in poultry house litter at high levels, but was not ubiquitous across all houses (Dumas et al, 2011), consistent with other reports of sporadic detection in chicken feces.…”

<i>Salmonella</i> Contamination in Layer Farms in China: Detection and Genetic Analysis

“…In farms A and H, some drinking nipples were contaminated with Salmonella. Previous studies have indicated that moist environments promote the multiplication of microflora (Rusin et al, 1998), and bacterial abundance on wet litter was found to more diverse than that in dry conditions (Dumas et al, 2011). Furthermore, the absence of dry cleaning between laying rounds reportedly worsens the Salmonella contamination status in conventional battery cages (Van Hoorebeke et al, 2010).…”

Costs of biosecurity measures in Brazilian laying hens farms in response to policies against Avian Influenza, Newcastle Disease and Salmonellosis

“…The environment in the production system can be a potential source of infections and the severity and outbreaks of the diseases are directly related to the level of contamination of the environment (DUMAS et al, 2011). According to Sesti (2005), the adoption of an effective biosecurity program is the best alternative to maintain commercial flocks free or controlled from the presence of diseases of economic impact in productivity or dangerous to public health.…”