Analyses of prevalence and molecular typing reveal the spread of antimicrobial-resistant Salmonella infection across two breeder chicken farms

Abstract

In this study, Salmonella prevalence and antimicrobial resistance were evaluated at various production stages in 2 geographically separated breeder farms (referred to as G and F). Day-old chicks for the breeder flock at farm F were purchased from farm G. A total of 219 Salmonella isolates, all identified as Salmonella enterica subsp. enterica serovar Enteritidis, were recovered from 1,430 samples (sick chicken carcasses and/or dead embryos). The isolation rates at breeder farms G and F were 10.53% (56/532) and 18.15% (163/898), respectively. Resistance to 4-6 antimicrobial agents was the most frequent phenotype during the laying stage at both farms, suggesting that chicks are exposed to higher risk of antimicrobial-resistant Salmonella infection during this stage of the breeding process. Using clustered regularly interspaced short palindromic repeat (CRISPR) typing, 5 CRISPR patterns were identified, out of which one pattern was shared by the 2 farms. In addition, pulsed-field gel electrophoresis (PFGE) typing result indicated that 2 clusters (PF-1 and PF-2) were shared among the 2 breeder farms, suggesting that strains were transmitted from breeder farm G to farm F via the trade of day-old chicks. Our findings suggested that the trade of day-old breeder chicks could be one of the potential Salmonella transmission routes, and antibiotics should be administered with caution during the laying stage.

Antimicrobial resistance monitoring of commensal Enterococcus faecalis in broiler breeders

“…Similar resistance profiles in MDR isolates with their corresponding genotypes within and between the farms and the occurrence of the same profiles in different farms may be an indication of the ease of spread of enterococcus strains ( Nowakiewicz et al., 2017a ). This study also suggest that the different resistance levels and patterns in MDR isolates may be related to the use of diverse antimicrobials during poultry production on each farm ( Fei et al., 2018 , Li et al., 2018 ).…”

“…The integrated production, processing, and distribution systems of the poultry industry can vertically transfer antimicrobial resistant bacteria from the breeding chickens to their offspring ( Olsen et al, 2011 ; Kim et al., 2012 ; Dierikx et al., 2013 , Seo et al., 2018 ). Although numerous studies on antimicrobial resistance in poultry have been reported, only a few studies have investigated the breeders ( Fei et al., 2018 ). In this study, E. faecalis from broiler breeders showed high resistance to a variety of antimicrobials and suggested a potential role as reservoirs for the transmission of resistant isolates throughout the poultry industry.…”

Characterization of Salmonella enterica Isolates from Diseased Poultry in Northern China between 2014 and 2018

“…All 55 Enteritidis isolates were assigned into ST11, a vastly distributed clone across the world [14,30,31]. However, PFGE analysis showed that the 55 isolates displayed nine banding patterns distinguishable by at least one band difference ( Figure 2); this banding pattern similarity was higher than that of S. Enteritidis isolates from breeder chickens reported recently [32]. No obviously epidemiological relatedness was explored from the same and different samples.…”

Prevalence of Salmonella Isolates and Their Distribution Based on Whole-Genome Sequence in a Chicken Slaughterhouse in Jiangsu, China

“…S. Enteritidis was also the most common serotype of human Salmonella infections in the USA during 2011 and 2016 (3). In China, S. Enteritidis was recognized as the most frequently isolated Salmonella serotype in chicken meat (30,31). The above data indicated that the S. Enteritidis was recognized as a dominant serotype worldwide.…”