Pathogens of Bovine Respiratory Disease in North American Feedlots Conferring Multidrug Resistance via Integrative Conjugative Elements

Abstract

In this study, we determined the prevalence of bovine respiratory disease (BRD)-associated viral and bacterial pathogens in cattle and characterized the genetic profiles, antimicrobial susceptibilities, and nature of antimicrobial resistance determinants in collected bacteria. Nasopharyngeal swab and lung tissue samples from 68 BRD mortalities in Alberta, Canada (n ‫؍‬ 42), Texas (n ‫؍‬ 6), and Nebraska (n ‫؍‬ 20) were screened using PCR for bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus, bovine herpesvirus 1, parainfluenza type 3 virus, Mycoplasma bovis, Mannheimia haemolytica, Pasteurella multocida, and Histophilus somni. Excepting bovine herpesvirus 1, all agents were detected. M. haemolytica (91%) and BVDV (69%) were the most prevalent, with cooccurrence in 63% of the cattle. Isolates of M. haemolytica (n ‫؍‬ 55), P. multocida (n ‫؍‬ 8), and H. somni (n ‫؍‬ 10) from lungs were also collected. Among M. haemolytica isolates, a clonal subpopulation (n ‫؍‬ 8) was obtained from a Nebraskan feedlot. All three bacterial pathogens exhibited a high rate of antimicrobial resistance, with 45% exhibiting resistance to three or more antimicrobials. M. haemolytica (n ‫؍‬ 18), P. multocida (n ‫؍‬ 3), and H. somni (n ‫؍‬ 3) from Texas and Nebraska possessed integrative conjugative elements (ICE) that conferred resistance for up to seven different antimicrobial classes. ICE were shown to be transferred via conjugation from P. multocida to Escherichia coli and from M. haemolytica and H. somni to P. multocida. ICE-mediated multidrug-resistant profiles of bacterial BRD pathogens could be a major detriment to many of the therapeutic antimicrobial strategies currently used to control BRD.

Detection and economic impact related to bovine respiratory disease, shrink, and traveling distance in feedlot cattle in Northwest Mexico

“…They found a prevalence of P. multocida from 7.11% to 14.09% in the states of Hidalgo and Queretaro, as well as a prevalence of M. haemolytica of 28.03%, which might have been caused by the use of bacterial culture as a diagnostic technique. PCR, on the other hand, is a more sensitive test that allowed the detection of a number of cases that failed to be detected by culture (6). Studies carried out in Colima and Yucatán found the BRSV average seroprevalences to be 50.8% and 90.8%, respectively (14,15), which are similar to the results found in this study.…”

“…Although clinical signs may raise the suspicion of BRD infection, laboratory confirmation is needed to make a definitive diagnosis. BRD diagnosis can be achieved by a variety of serological methods, agent isolation, fluorescent antibodies tests, immunohistochemistry, and molecularbased tests (6). Irrespective of the infectious agent involved, the presenting clinical signs of BRD can appear similar.…”

The nasopharyngeal microbiota of feedlot cattle that develop bovine respiratory disease

“…The bacteria most frequently associated with BRD are Mannheimia haemolytica, Pasteurella multocida, Histophilus somnus, Mycoplasma bovis, and occasionally Trueperella pyogenes (Griffin et al, 2010;Klima et al, 2014). Strains of these bacteria are considered opportunistic pathogens and are isolated from both healthy and sick cattle.…”

Biochemical and proteomic investigation of bovine nasal secretion

“…Some researchers sampled the upper airways of live animals (Corstvet et al, 1973), bronchoalveolar lavages (Caldow, 2001 and Senthilkumaran et al, 2013) while most studies have sampled lungs from animals that succumbed to BRD (Martin, 1983;Fulton et al, 2009;Burgess et al, 2011;and Klima et al, 2013). However, despite the likely importance of the nasal cavity as an Prior to this investigation, there have been no studies to characterise the biochemical and immunological properties of bovine NS.…”