Tetracycline Resistant Campylobacter jejuni Subtypes Emanating from Beef Cattle Administered Non-Therapeutic Chlortetracycline are Longitudinally Transmitted within the Production Continuum but are Not Detected in Ground Beef

Abstract

The impacts of the antimicrobial growth promoter (AGP), chlortetracycline with sulfamethazine (AS700), on the development of antimicrobial resistance and longitudinal transmission of Campylobacter jejuni within the beef production continuum were empirically determined. Carriage of tetracycline resistance determinants in the enteric bacterial community increased at a greater rate for AS700-treatment cattle. The majority of the bacteria from animals administered AS700 carried tetW. Densities of C. jejuni shed in feces increased over the confined feeding period, and the administration of AS700 did not conspicuously reduce C. jejuni densities in feces or within the intestine. The majority of C. jejuni isolates recovered were resistant to tetracycline, but the resistance rates to other antibiotics was low (≤20.1%). The richness of C. jejuni subtypes recovered from AS700-treated animals that were either resistant or susceptible to tetracycline was reduced, indicating selection pressure due to AGP administration. Moreover, a degree of subtype-specific resistance to tetracycline was observed. tetO was the primary tetracycline resistance determinant conferring resistance in C. jejuni isolates recovered from cattle and people. Clinically-relevant C. jejuni subtypes (subtypes that represent a risk to human health) that were resistant to tetracycline were isolated from cattle feces, digesta, hides, the abattoir environment, and carcasses, but not from ground beef. Thus, study findings indicate that clinically-relevant C. jejuni subtypes associated with beef cattle, including those resistant to antibiotics, do not represent a significant foodborne risk.

Local accessory gene sharing drives lineage-specific acquisition of antimicrobial resistance in Egyptian Campylobacter spp.

“…However global rates of antimicrobial resistance are rising (Mourkas et al, 2019; Zhao et al, 2016) in line with other Gram negative gastrointestinal pathogens (Tam et al, 2012; CDC, 2020). Widespread agricultural usage has driven the proliferation of tetracycline resistance through its use as a growth promoter (Abdi Hachesoo et al, 2014; Inglis et al, 2019). In particular, C. coli has shown an ability to acquire erythromycin resistance genes from other species (Mourkas et al, 2019).…”

Rates of fluoroquinolone resistance in domestically acquiredCampylobacter jejuniare increasing in people living within a model study location in Canada

“…Before December 2018, the continuous administration of antimicrobial agents, including tetracyclines and macrolides, at low doses in the feed of beef cattle was permitted (i.e., as antimicrobial growth promoters) (Public Health Agency of Canada 2019). We have previously observed the rapid proliferation of resistance to tetracycline in beef cattle within CFOs, presumable due to selection pressure and the close proximity of cattle to one another, which facilitates interanimal transmission (Inglis et al 2020a(Inglis et al , 2020bWebb et al 2018). The administration of FQs to cattle in Canada is limited to short-term therapeutic administration against bovine respiratory disease (Plumb 2011).…”

“…However, the epidemiology of cattle-borne C. jejuni remains enigmatic, although direct transmission via occupational contact has been identified as a risk factor in SWA (Hasselback 2002). Evidence indicates that the infection risk posed by consumption of beef contaminated with C. jejuni is low in SWA (Inglis et al 2020a(Inglis et al , 2020b, suggesting that alternate transmission mechanisms are responsible. It is recognized that certain clinically relevant subtypes of C. jejuni are associated with multiple nonhuman reservoirs, including beef cattle and chickens, and these subtypes (e.g., CC-21) have been designated as "generalists" (Dearlove et al 2016;Gripp et al 2011).…”

“…Amplicons were visualized by capillary electrophoresis using a QIAxcel (Qiagen Inc.). For positive controls, plasmids were constructed by amplifying the target gene from a positive intestinal digesta sample, ligating the product into a pDRIVE Cloning Vector (Qiagen Inc.), and transforming it into QIAGEN EZ Competent Cells (Qiagen Inc.) according to manufacturers' protocols (Inglis et al 2020b). Plasmids were sequence verified for the insert.…”

“…It is recognized that consumption of unpasteurized milk and untreated surface water can result in campylobacteriosis (Clark et al 2003;Pintar et al 2017). Although the mechanisms of transmission are poorly understood, emerging evidence is implicating beef cattle as an important reservoir of C. jejuni infecting people, although not likely via consumption of meat (Inglis et al 2020a(Inglis et al , 2020b.…”