Common use of Highlights Clause in Contracts

Highlights. Using single- or double-guarded swabs for deep nasopharyngeal sampling of preweaning calves shows a high agreement for recovery for Pasteurella multocida as evaluated by traditional culture methods. • Unguarded swabs had a higher percentage of polymicrobial growth compared with guarded swab methods, and their use should take this finding into account. ® JDS ▇▇▇▇▇▇▇▇▇ ▇▇▇▇▇-▇▇▇▇▇▇▇▇▇,1 ▇▇▇▇▇▇▇ ▇▇▇▇▇▇,1 ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇,2 ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇,3 ▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇▇,1 ▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇▇,1,4 ▇▇▇▇▇▇ ▇▇▇,1,4 and ▇▇▇▇▇▇▇ ▇. Pereira1* Abstract: Accurate isolation and identification of pathogens for an animal with bovine respiratory disease are of critical importance to direct appropriate decision-making related to the treatment of individual animals, as well as control and prevention options in a herd setting. The objective of this study was to compare nasopharyngeal sampling approaches to evaluate accuracy and agreement for the recovery of Mannheimia haemolytica (MH) and Pasteurella multocida (PM) from deep nasopharyngeal swabs (DNS) using 3 different swabs. Deep nasopharyngeal samples were collected from 45 dairy calves using 3 swabs: (1) double-guarded culture swab (DGS); (2) single-guarded culture swab (SGS); and (3) unguarded culture swab (UGS). To evaluate the degree of agreement between DGS, SGS, and UGS, culture results were compared for each calf sampled by using a kappa agreement test. Overall, findings from our study support that when using either SGS or DGS for DNS sampling of preweaning calves, a high agreement for recovery of PM is observed. A low recovery of MH was observed in the study, limiting the conclusion comparing the 3 DNS methods. Use of UGS is considered a potential alternative; however, a higher percentage of polymicrobial growth was found with UGS samples. ovine respiratory disease (BRD) is a multifactorial disease and can cause persistent negative economic impacts on the cattle industry due to higher morbidity and mortality rates of dairy calves and cattle in feedlots in the United States (Miles, 2009; ▇▇▇▇▇▇▇ et al., 2014; Peel, 2020). This multiagent complex is responsible for inducing clinical disease and lung pathology in young calves (▇▇▇▇▇▇▇▇ et al., 2015), leading to a decrease in feed intake and growth, increased antibiotic use and resistance, and higher mortal- ity rates (▇▇▇▇▇▇ et al., 2010; ▇▇▇▇▇▇▇ et al., 2020). Bovine respira- tory disease is a complex disease involving the interaction between environmental factors, host immunity, and microbial pathogens (▇▇▇▇▇▇ et al., 2010). Mannheimia haemolytica (MH) and Pasteu- ▇▇▇▇▇ multocida (PM) are the primary bacterial pathogens involved in BRD in cattle (Miles, 2009), and in preweaning dairy calves, PM is more frequently isolated compared with MH (▇▇▇▇▇▇ et al., 2021). Furthermore, aerobic culture is a key diagnostic component to recover MH and PM, enabling further characterization such as in vitro antimicrobial susceptibility testing and genetic analysis (▇▇▇ et al., 2018). One of the most common techniques for BRD diagnosis is the collection of deep nasopharyngeal swab (DNS) samples by using long double-guarded or single-guarded swabs (▇▇▇▇▇ et al., 2017). The advantage of using these guarded swabs is to reduce contamination from nostrils (double-guarded swabs) and to improve the accurate isolation of respiratory bacteria from DNS samples (▇▇▇▇▇ et al., 2017). The objective of this study was to compare nasopharyngeal sampling approaches to evaluate accuracy and agreement for the recovery of MH and PM from DNS using 3 different swabs. Deep nasopharyngeal samples were collected from a convenience sample of 45 dairy calves using 3 swabs: (1) double-guarded culture swab (DGS), (2) single-guarded culture swab (SGS), and (3) unguarded culture swab (UGS). To evaluate the degree of agreement between DGS, SGS, and UGS, culture results were compared for each calf sampled by using a kappa agreement test. Our hypothesis was that using SGS for DNS would generate high agreement for the recov- ery of MH and PM when compared with DGS, and that UGS DNS samples would have higher polymicrobial growth compared with either SGS or DGS. The University of California Institutional Animal Care and Use Committee (IACUC; #22232) approved all experimental pro- cedures conducted with animals for this study. A cross-sectional study design was used to collect DNS from one commercial dairy farm in California with a mixed herd, having Holstein, Jersey, and Jersey × Holstein crossbreds; this farm had a total milking herd of approximately 2,200 cows, with management practices commonly observed in California dairy farms. ▇▇▇▇▇▇ enrolled in this study were housed in wooden hutches in a sequential fashion based on birth order, which allowed calves to have nose-to-nose contact with adjacent calves only. Only female preweaning calves at or over 3 wk of age that did not have a farm history for treatment for any disease were included in the study. All calves were sampled at one of 4 distinct farm visits in May 2021. The sample size was based on the recovery of PM, and was based on an expected kappa of 0.8, with an expected ▇▇▇▇- dard error of 0.2, a prevalence of culture-positive for PM of 40%, and a confidence interval for significance at 95%, resulting in an estimated sample size of 37 animals. At enrollment, calves were examined by a veterinarian (RP or AG) by conducting a visual and hands-on evaluation, includ- ing thoracic ultrasound (TUS) of the lungs. Visual examinations included using the University of California–▇▇▇▇▇ BRD scoring system for preweaning dairy calves when examining and scoring eye discharge, nasal discharge, ear droop or head tilt, cough, and respiratory effort (▇▇▇ et al., 2014; Love et al., 2014). Calves that were severely depressed to the point of being unable to stand or unresponsive, or comatose were not eligible to be enrolled in the study. The TUS of the lungs was conducted by scanning the lungs us- ing a portable ultrasound with a linear probe (Easi-Scan: Go, IMV Imaging Ltd.), as previously described (▇▇▇▇▇▇▇▇▇ et al., 2014; Ol- livett and ▇▇▇▇▇▇▇▇▇, 2016). Briefly, a TUS score of 0 indicated a normally aerated lung, a TUS score of 1 indicated diffuse comet-tail artifacts without consolidation, a TUS score of 2 for findings with a consolidation ≥1 cm2 indicated lobular pneumonia, a TUS score of 3 for findings with 1 entire lung lobe consolidation indicated lobar pneumonia, a TUS score of 4 for findings with 2 entire lung lobe consolidation indicated lobar pneumonia and a TUS score of 5 for findings with ≥ 3 entire lung lobe consolidation indicated lobar pneumonia. A convenience sample of 45 female calves was enrolled and sampled using all 3 swab types for deep nasopharyngeal sampling: