Evaluation of a multiplex real-time PCR for detection of four bacterial agents commonly associated with bovine respiratory disease in bronchoalveolar lavage fluid (original) (raw)
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Scientific Reports, 2019
Respiratory tract infections are a major health problem and indication for antimicrobial use in cattle and in humans. Currently, most antimicrobial treatments are initiated without microbiological results, holding the risk of inappropriate first intention treatment. The main reason for this empirical treatment is the long turnaround time between sampling and availability of identification and susceptibility results. Therefore the objective of the present study was to develop a rapid identification procedure for pathogenic respiratory bacteria in bronchoalveolar lavage fluid (BALf) samples from cattle by MALDI-TOF MS, omitting the cultivation step on agar plates to reduce the turnaround time between sampling and identification of pathogens. The effects of two different liquid growth media and various concentrations of bacitracin were determined to allow optimal growth of Pasteurellaceae and minimise contamination. The best procedure was validated on 100 clinical BALf samples from cat...
Journal of Medical Microbiology, 2016
This study aimed to determine the occurrence of Mannheimia haemolytica, 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 Pasteurella multocida (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 %), Mycoplasma bovis (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 Mycoplasma bovis (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 microorganisms 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.
Slovenian Veterinary Research, 2017
Respiratory diseases often correspond to primary infections with different pathogens of cattle, causing heavy economic losses in young stock and breeding herds. Between 2012 and 2014, nasal swab samples were collected from twenty-eight herds from 133 affected live cattle that were clinically suffering from symptoms of respiratory disease, pyrexia, cough, serous nasal and lacrimal discharge, increased respiratory rate, and breath sounds. Individual swab samples were tested in the laboratory using three commercial and one in-house real-time PCR methods, to detect nucleic acids of a total of ten different respiratory pathogens. Pasteurella multocida ( P. multocida ) was detected in 58.65% of samples, Mannheimia haemolytica ( M. haemolytica ) in 15.04%, while Mycoplasma bovis ( M. bovis ) and Histophilus somni ( H. somni ) were positive in 9.77% of nasal swab samples. Among viral pathogens, the highest prevalence (40.60%) was observed for bovine respiratory syncytial virus (BRSV), follo...
Veterinary Research
This work modifies a loop-mediated isothermal amplification (LAMP) assay to detect the bovine respiratory disease (BRD) bacterial pathogens Pasteurella multocida, Mannheimia haemolytica, and Histophilus somni in a colorimetric format on a farm. BRD causes a significant health and economic burden worldwide that partially stems from the challenges involved in determining the pathogens causing the disease. Methods such as polymerase chain reaction (PCR) have the potential to identify the causative pathogens but require lab equipment and extensive sample processing making the process lengthy and expensive. To combat this limitation, LAMP allows accurate pathogen detection in unprocessed samples by the naked eye allowing for potentially faster and more precise diagnostics on the farm. The assay developed here offers 66.7–100% analytical sensitivity, and 100% analytical specificity (using contrived samples) while providing 60–100% concordance with PCR results when tested on five steers in...
Research in Veterinary Science, 2015
Three hundred ninety five calves were purchased from sale barns and delivered to the Willard Sparks Beef Research Center. Nasal swabs were collected to determine if presence of Mannheimia haemolytica and Pasteurella multocida in the upper respiratory tract (URT) can facilitate diagnosis of bovine respiratory disease (BRD). Samples were collected at arrival and at treatment for BRD. Clinically healthy control calves were sampled at time of treatment of sick calves. M. haemolytica was more commonly isolated from calves at treatment than at time of arrival or from control calves. M. haemolytica was more common in calves requiring treatment than in those never treated. Need for treatment and number of treatments were negatively associated with average daily gain, supporting the accuracy of diagnosis. These results suggest that URT sampling, when combined with clinical diagnosis, may assist in providing greater diagnostic accuracy, improving ability to evaluate risk factors, interventions, and treatments.
archives of razi institute, 2017
In this study, we performed a bacteriological investigation on bovine respiratory infections. Additionally, the study evaluates the efficacy of florfenicol 30 µg produced by Rooyan Darou Company (test group) as compared to a similar drug produced by Aboraihan Company (control group). Sampling was carried out on 30 calves at two farms with 30-55% incidence rate of respiratory disorders. Nasopharyngeal swabs were collected for culture, biochemical activity, and antibiograme testing from all the calves before commencing the treatment. The calves of the test group received florfenicol 30 µg (20 mg/kg, two intramuscular [IM] injections with a 48-hour interval). Similarly, the control group received the same drug dose produced by Aboraihan Company. All the calves were examined clinically before treatment, and ultimately, clinical index score was recorded for each calf based on Observation Gradings on days two, four, and seven after the treatment. The results of culture analysis and routin...
Irish Veterinary Journal, 2022
Background Bovine Respiratory Disease (BRD) is a multifactorial and economically important illness of cattle. The current study was designed to characterize the major bacterial pathogens associated with BRD and determine the antibiotic susceptibility patterns of isolates. Samples were collected from 400 pneumonic cases of cattle. Results Laboratory assay revealed isolation of 376 (94.0%) bacterial pathogens. The most prevalent bacterial pathogens recovered were Mannheimia haemolytica (M. haemolytica) followed by Pasteurella multocida (P. multocida), Histophilus somni (H. somni), and Bibersteinia trehalosi (B. trehalosi) from 191 (50.80%), 81 (21.54%), 56 (14.89%), and 48 (12.77%) samples, respectively. M. haemolytica strains were confirmed using multiplex PCR assay through the amplification of PHSSA (~ 325 bp) and Rpt2 (~ 1022 bp) genes. Capsular typing of P. multocida revealed amplification of serogroup A (hyaD-hyaC) gene (~ 1044 bp) and serogroup D (dcbF) gene (~ 657 bp). B. treha...
TURKISH JOURNAL OF VETERINARY AND ANIMAL SCIENCES
The present study was planned to detect the genetic elements of Mannheimia haemolytica and Pasteurella multocida in pneumonic sheep lungs. Pneumonia was diagnosed on the basis of gross pathological lesions. Lung tissues were collected at necropsy of sheep (n = 96) and subjected to isolation of total DNA. The M. haemolytica-specific PHSSA and Rpt2 genes, and the P. multocidaspecific KMT1 and the Omp87 genes were amplified using polymerase chain reaction (PCR). A housekeeping gene targeting the sheep cellular mitochondrial 12S ribosomal DNA was used as an internal control. PCR reactions were optimized using the positive and negative controls. Gene-specific PCR products were subjected to nucleotide sequencing for confirmation. The pneumonic lungs showed congestion and hemorrhagic changes with consolidation, which was most evident in the whole of the apical lobes and parts of the diaphragmatic lobes. PCR amplification showed detection of PHSSA (327 bp) and Rpt2 (~1022 bp) genes specific to M. haemolytica in 52 (54.1%), and the KMT1 (457 bp) and Omp87 (2627 bp) genes specific to P. multocida in 16 (16.6%) lung samples. Sequence analysis confirmed the PCR products for specific genes. This study highlighted the culture-independent, rapid, and confirmatory diagnosis of ovine pneumonic pasteurellosis caused by M. haemolytica and/or P. multocida.
Journal of Veterinary Diagnostic Investigation, 2010
Bovine respiratory disease (BRD) is the most costly disease of beef cattle in North America. Because Pasteurella multocida is a commensal of the upper respiratory tract, it is generally considered an opportunistic pathogen. However, studies in swine indicated that there may be a limited number of strains associated with disease, suggesting that some are more virulent than others. Although this may also be true of isolates from cattle, appropriate typing methods must be established before this possibility can be investigated. The purpose of this study was to compare effectiveness of polymerase chain reaction (PCR) fingerprinting to more traditional approaches for typing bovine P. multocida isolates. Isolates were obtained from 41 cases of fatal BRD and subjected to random amplified polymorphic DNA PCR (RAPD-PCR), whole cell protein (WCP) profiles, outer membrane protein (OMP) profiles, and serotyping. The discrimination index was calculated for each typing method and combinations of each using Simpson's index of diversity. Correlation coefficients were calculated to assess concordance between classification results achieved through genotypic (RAPD-PCR) and phenotypic (WCP, OMP, and serotyping) approaches. All characterization methods were capable of discriminating between isolates. However, there was poor concordance between techniques. There were also few significant associations between typing results and epidemiologic data. Random amplified polymorphic DNA PCR was validated as being a repeatable and reliable means of discriminating between P. multocida isolates obtained from cattle. Isolates obtained from fatal cases of BRD in calves in a commercial feedlot demonstrated significant diversity, justifying additional investigation into whether P. multocida is a strictly opportunistic pathogen in cattle.