Protection against Mycoplasma bovis infection in calves following intranasal vaccination with modified-live Mannheimia haemolytica expressing Mycoplasma antigens

2021 ◽  
pp. 105159
Author(s):  
Robert E. Briggs ◽  
Sheila R. Billing ◽  
William D. Boatwright ◽  
Bradley O. Chriswell ◽  
Eduardo Casas ◽  
...  
2021 ◽  
Vol 8 ◽  
Author(s):  
Sara Andrés-Lasheras ◽  
Reuben Ha ◽  
Rahat Zaheer ◽  
Catrione Lee ◽  
Calvin W. Booker ◽  
...  

A broad, cross-sectional study of beef cattle at entry into Canadian feedlots investigated the prevalence and epidemiology of antimicrobial resistance (AMR) in Mannheimia haemolytica, Pasteurella multocida, Histophilus somni, and Mycoplasma bovis, bacterial members of the bovine respiratory disease (BRD) complex. Upon feedlot arrival and before antimicrobials were administered at the feedlot, deep nasopharyngeal swabs were collected from 2,824 feedlot cattle in southern and central Alberta, Canada. Data on the date of feedlot arrival, cattle type (beef, dairy), sex (heifer, bull, steer), weight (kg), age class (calf, yearling), source (ranch direct, auction barn, backgrounding operations), risk of developing BRD (high, low), and weather conditions at arrival (temperature, precipitation, and estimated wind speed) were obtained. Mannheimia haemolytica, P. multocida, and H. somni isolates with multidrug-resistant (MDR) profiles associated with the presence of integrative and conjugative elements were isolated more often from dairy-type than from beef-type cattle. Our results showed that beef-type cattle from backgrounding operations presented higher odds of AMR bacteria as compared to auction-derived calves. Oxytetracycline resistance was the most frequently observed resistance across all Pasteurellaceae species and cattle types. Mycoplasma bovis exhibited high macrolide minimum inhibitory concentrations in both cattle types. Whether these MDR isolates establish and persist within the feedlot environment, requires further evaluation.


2011 ◽  
Vol 56 (No. 1) ◽  
pp. 29-35 ◽  
Author(s):  
A. Gabinaitiene ◽  
J. Siugzdaite ◽  
H. Zilinskas ◽  
R. Siugzda ◽  
S. Petkevicius

Bovine respiratory disease caused by Mycoplasma bovis is a major health problem of cattle worldwide. It inflicts considerable financial losses on beef herds and is the most common cause of mortality in dairy cattle. Bacteriological examination of 35 nasal cavity samples from calves younger than three months of age identified Mycoplasma bovis in eight (22.9%) samples. These cattle were followed until 17 months of age, and repeated examination of nasal cavity samples before necropsy identified Mycoplasma bovis in four (11.4%) samples. At necropsy and lung samples for bacteriological and histological examination were collected. To identify microorganisms from the Mollicutes class isolated from the nasal cavities of cattle we used the PCR method. Furthermore, Mycoplasma bovis was identified on the grounds of biochemical characteristics and by the disk growth inhibition test. The organism was found in 5.7% of calves younger than three months of age in combination with Pasteurella spp. Mycoplasma bovis in combination with Pasteurella multocida and Mannheimia haemolytica was isolated from 5.7% and 2.9% of cattle at 17 months. However, Pasteurella multocida was common in cattle at 17 months and Mannheimia haemolytica was isolated from both age groups of cattle. Histopathological examination of lung samples revealed broncho-interstitial pneumonia in 14.3% of samples. Mycoplasma bovis was isolated from 60.0% of broncho-insterstitial pneumonia cases. The organism was isolated more frequently from the group of calves rather than from the cattle group (P < 0.05). The most common bacterial agents were Pasteurella multocida and Mannheimia haemolytica.


2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity

2020 ◽  
Vol 8 (2) ◽  
pp. 164 ◽  
Author(s):  
Xifang Zhu ◽  
Yaqi Dong ◽  
Eric Baranowski ◽  
Xixi Li ◽  
Gang Zhao ◽  
...  

Molecules contributing to microbial cytoadhesion are important virulence factors. In Mycoplasma bovis, a minimal bacterium but an important cattle pathogen, binding to host cells is emerging as a complex process involving a broad range of surface-exposed structures. Here, a new cytoadhesin of M. bovis was identified by producing a collection of individual knock-out mutants and evaluating their binding to embryonic bovine lung cells. The cytoadhesive-properties of this surface-exposed protein, which is encoded by Mbov_0503 in strain HB0801, were demonstrated at both the mycoplasma cell and protein levels using confocal microscopy and ELISA. Although Mbov_0503 disruption was only associated in M. bovis with a partial reduction of its binding capacity, this moderate effect was sufficient to affect M. bovis interaction with the host-cell tight junctions, and to reduce the translocation of this mycoplasma across epithelial cell monolayers. Besides demonstrating the capacity of M. bovis to disrupt tight junctions, these results identified novel properties associated with cytoadhesin that might contribute to virulence and host colonization. These findings provide new insights into the complex interplay taking place between wall-less mycoplasmas and the host-cell surface.


Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1470
Author(s):  
Ana García-Galán ◽  
Juan Seva ◽  
Ángel Gómez-Martín ◽  
Joaquín Ortega ◽  
Francisco Rodríguez ◽  
...  

Bovine respiratory disease (BRD) is an important viral and/or bacterial disease that mainly affects feedlot calves. The involvement of Mycoplasma bovis in BRD can lead to chronic pneumonia poorly responsive to antimicrobial treatment. Caseonecrotic bronchopneumonia is a pulmonary lesion typically associated with M. bovis. In Spain, M. bovis is widely distributed in the feedlots and circulating isolates are resistant to most antimicrobials in vitro. However, the role of this species in clinical respiratory disease of feedlot calves remains unknown. Furthermore, available data are relative to a fixed panel of antimicrobials commonly used to treat BRD, but not to the specific set of antimicrobials that have been used for treating each animal. This study examined 23 feedlot calves raised in southeast Spain (2016–2019) with clinical signs of respiratory disease unresponsive to treatment. The presence of M. bovis was investigated through bacteriology (culture and subsequent PCR), histopathology and immunohistochemistry. The pathogen was found in 86.9% (20/23) of the calves, mainly in the lungs (78.26%; 18/23). Immunohistochemistry revealed M. bovis antigens in 73.9% (17/23) of the calves in which caseonecrotic bronchopneumonia was the most frequent lesion (16/17). Minimum inhibitory concentration assays confirmed the resistance of a selection of 12 isolates to most of the antimicrobials specifically used for treating the animals in vivo. These results stress the importance of M. bovis in the BRD affecting feedlot calves in Spain.


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