Frequency, serotype distribution, and antimicrobial susceptibility patterns of Salmonella in small poultry flocks in California

Abstract

Backyard poultry operations are increasingly popular and commonplace in both rural and suburban locations. Although Salmonella surveillance programs are well established for large commercial poultry systems, information on smaller operations is lacking. We identified the occurrence and serotype distribution of Salmonella spp. recovered from backyard flock cases submitted to the California Animal Health and Food Safety Laboratory System (Davis, CA) in 2012-2015, and evaluated minimum inhibitory concentration for 12 antimicrobials as well as the lesions associated with Salmonella spp. in these cases. From records of 2,347 backyard flock cases with 2,627 samples, 44 samples (1.7%) were positive for Salmonella spp. DNA by PCR, and 41 (1.6%) of these samples yielded a Salmonella isolate by culture for further characterization. Seventeen different serotypes, including 3 isolates identified to the serogroup level, were identified from these isolates. Antimicrobial resistance was infrequent; however, 2 multidrug-resistant isolates were identified. Enteric or systemic lesions associated with Salmonella recovery were uncommon, with 77.3% of cases having no disease attributable to Salmonella. Recovered serotypes overlap with those seen in commercial poultry as well as in foodborne outbreaks reported by the Centers for Disease Control and Prevention in humans. Zoonotic risks via contact and food product contamination make monitoring of backyard flocks for Salmonella a critical part of flock surveillance programs, and we propose a potential sampling scheme.

Antimicrobial resistance in fecal Escherichia coli and Salmonella enterica isolates: a two-year prospective study of small poultry flocks in Ontario, Canada

“…Although the frequency of Salmonella enterica was very low in our study [26], and many of the Salmonella isolates were pan-susceptible, some were resistant to streptomycin alone, or to streptomycin, sulfisoxazole, trimethoprim-sulfamethoxazole, and tetracycline. Our findings agree with a recent study that evaluated AMR in Salmonella isolated from small flock cases at the California Animal Health and Food Safety Laboratory System, and found resistance to streptomycin, sulfonamides, and tetracycline [34].…”

Prevalence, Serotyping, Molecular Typing, and Antimicrobial Resistance of Salmonella Isolated From Conventional and Organic Retail Ground Poultry

“…The presence of antimicrobial resistant Salmonella in retail meats, particularly in poultry, is a major risk to the treatment of foodborne illnesses caused by this bacterial pathogen ( Antunes et al, 2016 ; Chai et al, 2017 ). The presence of multidrug resistant (MDR), nontyphoidal Salmonella in retail meats has been reported in several studies ( Cetinkaya et al, 2008 ; Zhao et al, 2008 ; Yildirim et al, 2011 ; Thai et al, 2012 ; Van et al, 2012 ; Maka et al, 2014 ; Yang et al, 2014 ; Iwamoto et al, 2017 ; Clothier et al, 2018 ). Most of the antimicrobial resistance genes in Salmonella are carried on conjugative plasmids that facilitate transfer between different isolates ( Jones and Stanley, 1992 ; Rotgers and Casadesüs, 1999 ; Carattoli, 2003 ; Rychlik et al, 2006 ).…”

Molecular Detection of Colistin Resistance mcr-1 Gene in Multidrug-Resistant Escherichia coli Isolated from Chicken

“…Furthermore, the resistance of Enterobacteriaceae to multiple antibiotics [ 21 ] makes the study of the antibiotic susceptibility profile and antimicrobial resistance gene detection a priority [ 22 ]. So far, mcr-1 positive Enterobacteriaceae have been detected in animals, food, humans, and the environment in more than 25 countries across four continents [ 18 , 23 , 24 , 25 , 26 , 27 ].…”