The occurrence of Salmonella, extended‐spectrum β‐lactamase producing Escherichia coli and carbapenem resistant non‐fermenting Gram‐negative bacteria in a backyard poultry flock environment

Abstract

Increase in the number of small‐scale backyard poultry flocks in the USA has substantially increased human‐to‐live poultry contact, leading to increased public health risks of the transmission of multi‐drug resistant (MDR) zoonotic and food‐borne bacteria. The objective of this study was to detect the occurrence of Salmonella and MDR Gram‐negative bacteria (GNB) in the backyard poultry flock environment. A total of 34 backyard poultry flocks in Washington State (WA) were sampled. From each flock, one composite coop sample and three drag swabs from nest floor, waterer‐feeder, and a random site with visible faecal smearing, respectively, were collected. The samples were processed for isolation of Salmonella and other fermenting and non‐fermenting GNB under ceftiofur selection. Each isolate was identified to species level using MALDI‐TOFF and tested for resistance against 16 antibiotics belonging to eight antibiotic classes. Salmonella serovar 1,4,[5],12:i:‐ was isolated from one (3%) out of 34 flocks. Additionally, a total of 133 ceftiofur resistant (CefR) GNB including Escherichia coli (53), Acinetobacter spp. (45), Pseudomonas spp. (22), Achromobacter spp. (8), Bordetella trematum (1), Hafnia alvei (1), Ochrobactrum intermedium (1), Raoultella ornithinolytica (1), and Stenotrophomonas maltophilia (1) were isolated. Of these, 110 (82%) isolates displayed MDR. Each flock was found positive for the presence of one or more CefR GNB. Several MDR E. coli (n = 15) were identified as extended‐spectrum β‐lactamase (ESBL) positive. Carbapenem resistance was detected in non‐fermenting GNB including Acinetobacter spp. (n = 20), Pseudomonas spp. (n = 11) and Stenotrophomonas maltophila (n = 1). ESBL positive E. coli and carbapenem resistant non‐fermenting GNB are widespread in the backyard poultry flock environment in WA State. These GNB are known to cause opportunistic infections, especially in immunocompromised hosts. Better understanding of the ecology and epidemiology of these GNB in the backyard poultry flock settings is needed to identify potential risks of transmission to people in proximity.

Risk Factors for Positivity to Shiga Toxin-Producing Escherichia coli and Salmonella enterica in Backyard Production Systems Animals from Metropolitana Region, Chile: A Threat to Public Health?

“…The positivity rates for S. enterica reported in this study are similar to those previously described for BPS in Chile [6,46] and in other countries [42,43,78,79]. In terms of the risk factor analysis, evidence suggests that those variables that were found to be significant and increased the risk of positivity with respect to S. enterica in this study were also found to be significant in previous studies [6].…”

Association of Broiler Litter Microbiome Composition and Campylobacter Isolation

“…The abundance of the genus Stenotrophomonas decreased when Campylobacter was isolated in boot socks. Stenotrophomonas are Gram-negative bacteria that are opportunistic pathogens in humans ( 66 ), are the predominant bacteria aerosolized from swine feces ( 67 ), and have been documented in the poultry environment ( 68 ), including litter ( 12 ) and poultry meat ( 69 ). Li et al ( 70 ) reported that Stenotrophomonas was enriched in the jejunum of chickens reared at 33.5°C and was associated with multiple lipid metabolic pathways.…”

Occurrence of potentially zoonotic and cephalosporin resistant enteric bacteria among shelter dogs in the Central and South-Central Appalachia

“…The approach of initial selection for resistance to the third-generation cephalosporin (ceftiofur), has been used previously in cattle and poultry [25,26]. Here, we employed similar approach to selectively isolate enteric bacteria that are not only resistant to cephalosporins, but also resistant to other antibiotic classes.…”

“…One gram of fecal sample was resuspended in 5 ml of phosphate buffered saline (PBS) and incubated at room temperature for 5 min. Fifty and 150 μl of sample were transferred onto a MacConkey agar plate supplemented with Ceftiofur (8 μg/ml) and evenly spread over the surface of the agar as described previously [25]. The plates were then incubated at 37°C for 15 to 18 h. Two to three colonies representing a unique colony morphotype were selected, transferred to 5 ml LB containing Ceftiofur (8 μg/ml), mixed well and then incubated again at 37°C for 15 to 18 h. Following incubation, the cultures were preserved in 15% (v/v) glycerol and frozen at -80°C.…”