Journal Article

Limitations of bacterial culture, viral PCR, and tulathromycin susceptibility from upper respiratory tract samples in predicting clinical outcome of tulathromycin control or treatment of bovine respiratory disease in high-risk feeder heifers

Taube, Patrick C., Pollreisz, John P., Bechtol, David T., Sarchet, Jeffrey J., Saltman, Roger L., Blanding, Mitchell R.

2022

Overview

A cross-sectional prospective cohort study including 1026 heifers administered tulathromycin due to high risk of clinical signs of bovine respiratory disease (BRD), measured poor association between BRD clinical outcomes and results of bacterial culture and tulathromycin susceptibility from BRD isolates of deep nasopharyngeal swabs (DNS) and adequate association with viral polymerase chain reaction (PCR) results from nasal swabs. Isolation rates from DNS collected on day-0 and at 1 st BRD-treatment respectively were: Mannheimia haemolytica (10.9% & 34.1%); Pasteurella multocida (10.4% & 7.4%); Mycoplasma bovis (1.0% & 36.6%); and Histophilus somni (0.7% & 6.3%). Prevalence of BRD viral nucleic acid on nasal swabs collected exclusively at 1 st BRD-treatment were: bovine parainfluenza virus type-3 (bPIV-3) 34.1%; bovine viral diarrhea virus (BVDV) 26.3%; bovine herpes virus type-1 (BHV-1) 10.8%; and bovine respiratory syncytial virus (BRSV) 54.1%. Increased relative risk, at 95% confidence intervals, of 1 st BRD-treatment failure was associated with positive viral PCR results: BVDV 1.39 (1.17–1.66), bPIV-3 1.26 (1.06–1.51), BHV-1 1.52 (1.25–1.83), and BRSV 1.35 (1.11–1.63) from nasal swabs collected at 1 st BRD-treatment and culture of M . haemolytica 1.23 (1.00–1.51) from DNS collected at day-0. However, in this population of high-risk feeder heifers, the predictive values of susceptible and resistant isolates had inadequate association with BRD clinical outcome. These results indicate, that using tulathromycin susceptibility testing of isolates of M . haemolytica or P . multocida from DNS collected on arrival or at 1 st BRD-treatment to evaluate tulathromycin clinical efficacy, is unreliable.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Analysis / Animals / Anti-Bacterial Agents - pharmacology / Anti-Bacterial Agents - therapeutic use / Antimicrobial agents / Bacterial infections / Biology and Life Sciences / Bovine respiratory disease complex / Bovine Respiratory Disease Complex - drug therapy / Bovine Respiratory Disease Complex - microbiology / Bovine Respiratory Disease Complex - pathology / Care and treatment / Cattle / Cattle Diseases - drug therapy / Cattle Diseases - microbiology / Cattle Diseases - pathology / Clinical outcomes / Confidence intervals / Cross-Sectional Studies / Diarrhea / Diarrhea Viruses, Bovine Viral - drug effects / Diarrhea Viruses, Bovine Viral - genetics / Diarrhea Viruses, Bovine Viral - isolation & purification / Disaccharides - pharmacology / Disaccharides - therapeutic use / DNA, Viral - genetics / DNA, Viral - metabolism / Drug dosages / Health risks / Health services / Herpesvirus 1, Bovine - drug effects / Herpesvirus 1, Bovine - genetics / Herpesvirus 1, Bovine - isolation & purification / Heterocyclic Compounds - pharmacology / Heterocyclic Compounds - therapeutic use / Infections / Mannheimia haemolytica - drug effects / Mannheimia haemolytica - isolation & purification / Medicine and Health Sciences / Microbial Sensitivity Tests / Nasopharynx - microbiology / Nasopharynx - virology / Nucleic acids / Parainfluenza / Pasteurella multocida - drug effects / Pasteurella multocida - isolation & purification / Pathogens / Polymerase Chain Reaction / Prospective Studies / Respiratory diseases / Respiratory syncytial virus / Respiratory Syncytial Virus, Bovine - drug effects / Respiratory Syncytial Virus, Bovine - genetics / Respiratory Syncytial Virus, Bovine - isolation & purification / Respiratory tract / Risk / Risk Factors / RNA, Viral - genetics / RNA, Viral - metabolism / Treatment Failure / Veterinary medicine / Viruses