Determination of bacterial aetiologic factor on tracheobronchial lavage in relation to clinical signs of bovine respiratory disease

Abstract

This study aimed to determine the occurrence of Mannheimiahaemolytica, Pasteurella multocida and Mycoplasma spp., in relation to clinical signs of respiratory disease. Tracheobronchial lavage samples were collected from 96 (healthy and unhealthy) cattle in the State of São Paulo, Brazil. Mycoplasma spp. (12.5 %) and Pasteurellamultocida (15.50 %) were the most prevalent species. Bacillus sp., Staphylococcus sp., Escherichia coli, Klebsiella oxytoca, Pseudomonas aeruginosa and Klebsiella pneumoniae were also isolated. Mollicutes (70.83 %), Mycoplasmabovis (2.94 %) and Mycoplasma dispar (38.23 %) were identified using conventional PCR. Submassive sound on acoustic percussion of the thorax was associated with the absence of Mollicutes (P=0.025). Whistling (P=0.076) and coarse crackle (P=0.046) were associated with the absence of Mycoplasma dispar. Clear sound on acoustic percussion of the thorax was associated with the absence of Mycoplasmabovis (P=0.007). Coughing was associated with the presence of Pasteurellamultocida [P=0.035; confidence interval (CI), 1.12-26.89], but its absence was associated with mucopurulent (P=0.0215; CI, 1.55-34.5) and mucoid nasal discharge (P=0.068; CI, 19-28.5), submassive sound (P=0.031; CI, 1.23-75.5), fine crackle (P=0.058; CI, 1.23-20.1) and coarse crackle (P=0.046; CI, 2.38-70.8). The high prevalence of Pasteurella multocida and Mycoplasma spp. in unhealthy calves increases the importance of these micro-organisms in the pathogenesis of respiratory diseases. This study increases the information about the role of Mycoplasma dispar in respiratory diseases. Differences in some species in relation to clinical signs can be applied as a presumptive diagnosis.

Bacterial pathogens of the lower respiratory tract of calves from Brazilian rural settlement herds and their association with clinical signs of bovine respiratory disease

“…Mollicutes were isolated in BRD and healthy calves. These microorganisms were also detected by PCR in 20.6% of the direct material (tracheobronchial fluid), and this result were lower in percentage compared to those reported by Oliveira et al (2016) and Marques et al (2007). Only M. dispar was detected in samples.…”

“…Only M. dispar was detected in samples. Oliveira et al (2016) reported a higher frequency of M. dispar in trachoebronchial lavage samples, particularly in healthy calves. However, Autio et al (2007), Marques et al (2007), and Angen et al (2009) reported higher prevalence in BRD animals.…”

“…01.0 (01/99) --(--) 00.7 (01/141) --(--) 1.000 E. coli 01.0 (01/99) --(--) 00.7 (01/141) --(--) 1.000 E. aerogenes 01.0 (01/99) --(--) 00.7 (01/141) --(--) 1.000 S. maltophilia 01.0 (01/99) --(--) 00.7 (01/141) -- ( were obtained by Benesi et al (2013). However these species were isolated in other studies (Härtel et al 2004, Autio et al 2007, Angen et al 2009, Oliveira et al 2016. The high occurrence of Bacillus spp.…”

“…Benesi et al (2013) detected Staphylococcus spp., Bacillus spp., Streptococcus spp., P. aeruginosa and enterobacteria. Evaluating calves from an intensive production type, Oliveira et al (2016) also detected Bacillus spp., Staphylococcus spp., P. aeruginosa and E. coli, but in lower prevalence. In other countries, Elshafee (2003) detected Staphylococcus spp., Bacillus spp., Enterobacter spp., Escherichia spp., Pseudomonas spp.…”

“…mycoides SC is also an important microbe due to its role in Contagious Bovine Pleuropneumonia (OIE 2014), as well as M. dispar which is standing out as an important pathogen of BRD (Thomas et al 2002, Marques et al 2007, Angen et al 2009, Šiugždaitė et al 2015, Oliveira et al 2016. In Brazil, there are few studies for the bacterial components of respiratory tract of healthy and BRD cattle (Gonçalves 1987, Barros et al 1994, Benesi et al 2013, Oliveira et al 2016. In addition, there is a lack of studies of microbes in the respiratory tract of calves of small producers such as those from family farms.…”