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Frontiers in Veterinary Science 2023Bovine respiratory disease (BRD) is a leading cause of disease in feedlot and stocker calves with () as one of the most common etiologies. One of the most effective...
Bovine respiratory disease (BRD) is a leading cause of disease in feedlot and stocker calves with () as one of the most common etiologies. One of the most effective means of controlling BRD is through metaphylaxis, which involves administering antimicrobials to all animals at high risk of developing BRD. However, increasing prevalence of multidrug resistant (MDR) may reduce efficacy of metaphylaxis due to decreased susceptibility to drugs used for metaphylaxis. Primarily, this study aimed to determine the effect of tulathromycin metaphylaxis and subsequent BRD treatment on antimicrobial resistance (AMR) in isolated from stocker calves. Secondary objectives included evaluating the effect of metaphylaxis and treatment for BRD on animal health and comparing the genetic relationship of isolated. Crossbred beef heifers ( = 331, mean weight = 232, SD = 17.8 kg) at high risk for BRD were randomly assigned to receive tulathromycin metaphylaxis (META, = 167) or not (NO META, = 164). Nasopharyngeal swabs were collected for isolation, antimicrobial susceptibility testing and whole genome sequencing at arrival and 3 (WK3) and 10 (WK10) weeks later. Mixed-effects logistic regression was used to identify risk factors for isolation of and MDR (resistant to ≥3 antimicrobial drug classes) at 3 and 10 weeks, BRD morbidity, and crude mortality. Animals in the META group had higher odds of isolation of MDR at 3 weeks [OR (95% CI) = 13.08 (5-30.9), < 0.0001] and 10 weeks [OR (95% CI) = 5.92 (1.34-26.14), = 0.019] after arrival. There was no difference in risk of isolation of any (resistant or susceptible) between META and NO META groups at all timepoints. Animals in the NO META group had 3 times higher odds of being treated for BRD [WK3: OR (95% CI) = 3.07 (1.70-5.52), = 0.0002; WK10: OR (95% CI) = 2.76 (1.59-4.80), = 0.0002]. Antimicrobial resistance genes found within isolates were associated with integrative conjugative element (ICE) genes. Tulathromycin metaphylaxis increased risk of isolation of MDR and in this population, the increase in MDR appeared to be associated with ICE containing antimicrobial resistance genes for multiple antimicrobial classes. This may have important implications for future efficacy of antimicrobials for control and treatment of BRD.
PubMed: 38053814
DOI: 10.3389/fvets.2023.1256997 -
Microbiome Jul 2023Bovine respiratory disease (BRD) is one of the most common diseases in intensively managed cattle, often resulting in high morbidity and mortality. Although several...
BACKGROUND
Bovine respiratory disease (BRD) is one of the most common diseases in intensively managed cattle, often resulting in high morbidity and mortality. Although several pathogens have been isolated and extensively studied, the complete infectome of the respiratory complex consists of a more extensive range unrecognised species. Here, we used total RNA sequencing (i.e., metatranscriptomics) of nasal and nasopharyngeal swabs collected from animals with and without BRD from two cattle feedlots in Australia.
RESULTS
A high abundance of bovine nidovirus, influenza D, bovine rhinitis A and bovine coronavirus was found in the samples. Additionally, we obtained the complete or near-complete genome of bovine rhinitis B, enterovirus E1, bovine viral diarrhea virus (sub-genotypes 1a and 1c) and bovine respiratory syncytial virus, and partial sequences of other viruses. A new species of paramyxovirus was also identified. Overall, the most abundant RNA virus, was the bovine nidovirus. Characterisation of bacterial species from the transcriptome revealed a high abundance and diversity of Mollicutes in BRD cases and unaffected control animals. Of the non-Mollicutes species, Histophilus somni was detected, whereas there was a low abundance of Mannheimia haemolytica.
CONCLUSION
This study highlights the use of untargeted sequencing approaches to study the unrecognised range of microorganisms present in healthy or diseased animals and the need to study previously uncultured viral species that may have an important role in cattle respiratory disease. Video Abstract.
Topics: Animals; Cattle; Rhinitis; Australia; Respiratory Tract Diseases; Viruses; Cattle Diseases
PubMed: 37491320
DOI: 10.1186/s40168-023-01591-1 -
International Journal of Molecular... Apr 2024Bovine respiratory disease (BRD) is the leading cause of morbidity and mortality in cattle raised in North America. At the feedlot, cattle are subject to metaphylactic...
Bovine respiratory disease (BRD) is the leading cause of morbidity and mortality in cattle raised in North America. At the feedlot, cattle are subject to metaphylactic treatment with macrolides to prevent BRD, a practice that may promote antimicrobial resistance and has resulted in an urgent need for novel strategies. is one of the major bacterial agents of BRD. The inhibitory effects of two amphipathic, α-helical (PRW4, WRL3) and one β-sheet (WK2) antimicrobial peptides were evaluated against multidrug-resistant (MDR) isolated from Alberta feedlots. WK2 was not cytotoxic against bovine turbinate (BT) cells by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. All three peptides inhibited , with WK2 being the most efficacious against multiple isolates. At 8-16 µg/mL, WK2 was bactericidal against Mh 330 in broth, and at 32 µg/mL in the presence of BT cells, it reduced the population by 3 logs CFU/mL without causing cytotoxic effects. The membrane integrity of Mh 330 was examined using NPN (1-N-phenylnaphthylamine) and ONPG (o-Nitrophenyl β-D-galactopyranoside), with both the inner and outer membranes being compromised. Thus, WK2 may be a viable alternative to the use of macrolides as part of BRD prevention and treatment strategies.
Topics: Animals; Cattle; Anti-Bacterial Agents; Antimicrobial Peptides; Bovine Respiratory Disease Complex; Mannheimia haemolytica; Microbial Sensitivity Tests; Protein Conformation, alpha-Helical; Protein Conformation, beta-Strand
PubMed: 38673750
DOI: 10.3390/ijms25084164 -
International Journal of Molecular... Jan 2024Respiratory diseases in ruminants are a main cause of economic losses to farmers worldwide. Approximately 25% of ruminants experience at least one episode of respiratory...
Respiratory diseases in ruminants are a main cause of economic losses to farmers worldwide. Approximately 25% of ruminants experience at least one episode of respiratory disease during the first year of life. is the main etiological bacterial agent in the ruminant respiratory disease complex. can secrete several virulence factors, such as leukotoxin, lipopolysaccharide, and proteases, that can be targeted to treat infections. At present, little information has been reported on the secretion of A2 proteases and their host protein targets. Here, we obtained evidence that A2 proteases promote the degradation of hemoglobin, holo-lactoferrin, albumin, and fibrinogen. Additionally, we performed biochemical characterization for a specific 110 kDa Zn-dependent metalloprotease (110-Mh metalloprotease). This metalloprotease was purified through ion exchange chromatography and characterized using denaturing and chaotropic agents and through zymography assays. Furthermore, mass spectrometry identification and 3D modeling were performed. Then, antibodies against the 110 kDa-Mh metalloprotease were produced, which achieved great inhibition of proteolytic activity. Finally, the antibodies were used to perform immunohistochemical tests on postmortem lung samples from sheep with suggestive histology data of pneumonic mannheimiosis. Taken together, our results strongly suggest that the 110-Mh metalloprotease participates as a virulence mechanism that promotes damage to host tissues.
Topics: Cattle; Sheep; Animals; Mannheimia haemolytica; Pasteurellosis, Pneumonic; Metalloproteases; Peptide Hydrolases; Ruminants; Collagenases; Zinc; Sheep Diseases
PubMed: 38279292
DOI: 10.3390/ijms25021289 -
Frontiers in Veterinary Science 2024An increase in chronic, non-responsive bovine respiratory disease (BRD) infections in North American feedlot cattle is observed each fall, a time when cattle are... (Review)
Review
An increase in chronic, non-responsive bovine respiratory disease (BRD) infections in North American feedlot cattle is observed each fall, a time when cattle are administered multiple antimicrobial treatments for BRD. A number of factors are responsible for BRD antimicrobial treatment failure, with formation of biofilms possibly being one. It is widely accepted that biofilms play a role in chronic infections in humans and it has been hypothesized that they are the default lifestyle of most bacteria. However, research on bacterial biofilms associated with livestock is scarce and significant knowledge gaps exist in our understanding of their role in AMR of the bacterial BRD complex. The four main bacterial species of the BRD complex, , , , and are able to form biofilms and there is evidence that at least retains this ability . However, there is a need to elucidate whether their biofilm-forming ability contributes to pathogenicity and antimicrobial treatment failure of BRD. Overall, a better understanding of the possible role of BRD bacterial biofilms in clinical disease and AMR could assist in the prevention and management of respiratory infections in feedlot cattle. We review and discuss the current knowledge of BRD bacteria biofilm biology, study methodologies, and their possible relationship to AMR.
PubMed: 38933702
DOI: 10.3389/fvets.2024.1353551 -
Vaccines Apr 2024is a bovine respiratory pathogen commonly associated with bacterial bronchopneumonia. Current vaccine strategies have shown variable efficacy in feedlot cattle, and...
BACKGROUND
is a bovine respiratory pathogen commonly associated with bacterial bronchopneumonia. Current vaccine strategies have shown variable efficacy in feedlot cattle, and therefore novel vaccines are needed. spores have been investigated as a mucosal vaccine platform, due to their ability to bind and present antigens to the mucosa and act as an adjuvant. The aim of this study was to develop two spore-based mucosal vaccines targeting and evaluate their immunogenicity in mice.
METHODS
Two antigen constructs composed of cholera toxin B subunit, leukotoxin, and either the outer membrane protein PlpE (MhCP1) or GS60 (MhCP2) were synthesized, purified and then bound to spores as vaccines. In two separate mice trials, the spore-bound vaccines (Spore-MhCP1 and Spore-MhCP2) were administered to mice through intranasal and intragastric routes, while free antigens were administered intranasally and intramuscularly. Unbound spores were also evaluated intranasally. Antigen-specific serum IgG and mucosal IgA from bronchoalveolar lavage, feces, and saliva were measured after vaccination. Mice sera from all treatment groups were assessed for their bactericidal activity against .
RESULTS
In both mice experiments, intramuscular immunization induced the strongest serum IgG antibody response. However, the intranasal administration of Spore-MhCP1 and Spore-MhCP2 elicited the greatest secretory IgA-specific response against leukotoxin, PlpE, and GS60 in bronchoalveolar lavage, saliva, and feces ( < 0.05). Compared to the intranasal administration of free antigen, spore-bound antigen groups showed greater bactericidal activity against ( < 0.05).
CONCLUSIONS
Since intranasally delivered Spore-MhCP1 and Spore-MhCP2 elicited both systemic and mucosal immune responses in mice, these vaccines may have potential to mitigate lung infection in cattle by restricting colonization and proliferation in the respiratory tract. The efficacy of these mucosal spore-based vaccines merits further assessment against in cattle.
PubMed: 38675757
DOI: 10.3390/vaccines12040375 -
Microbial Pathogenesis Jul 2024Mannheimiahaemolytica is an opportunistic agent of the respiratory tract of bovines, a member of the Pasteurellaceae family, and the causal agent of fibrinous...
Mannheimiahaemolytica is an opportunistic agent of the respiratory tract of bovines, a member of the Pasteurellaceae family, and the causal agent of fibrinous pleuropneumonia. This bacterium possesses different virulence factors, allowing it to colonize and infect its host. The present work describes the isolation and characterization of a serine protease secreted by M. haemolytica serotype 1. This protease was isolated from M. haemolytica cultured media by precipitation with 50 % methanol and ion exchange chromatography on DEAE-cellulose. It is a 70-kDa protease able to degrade sheep and bovine fibrinogen or porcine gelatin but not bovine IgG, hemoglobin, or casein. Mass spectrometric analysis indicates its identity with protease IV of M. haemolytica. The proteolytic activity was active between pH 5 and 9, with an optimal pH of 8. It was stable at 50 °C for 10 min but inactivated at 60 °C. The sera of bovines with chronic or acute pneumonia recognized this protease. Still, it showed no cross-reactivity with rabbit hyperimmune serum against the secreted metalloprotease from Actinobacilluspleuropneumoniae, another member of the Pasteurellaceae family. M. haemolytica secreted proteases could contribute to the pathogenesis of this bacterium through fibrinogen degradation, a characteristic of this fibrinous pleuropneumonia.
Topics: Animals; Mannheimia haemolytica; Sheep; Cattle; Fibrinogen; Hydrogen-Ion Concentration; Serine Proteases; Temperature; Proteolysis; Molecular Weight; Gelatin; Enzyme Stability; Bacterial Proteins; Mass Spectrometry; Chromatography, Ion Exchange; Swine; Virulence Factors
PubMed: 38763316
DOI: 10.1016/j.micpath.2024.106706 -
Brazilian Journal of Microbiology :... Dec 2023Bovine respiratory disease (BRD) is a multifactorial and predominantly multietiological disease that affects dairy cattle herds worldwide, being more frequent in young...
Bovine respiratory disease (BRD) is a multifactorial and predominantly multietiological disease that affects dairy cattle herds worldwide, being more frequent in young animals. The occurrence of BRD was investigated in lactating cows from two high-yielding dairy herds in southern Brazil. To determine the etiology of the clinical cases of acute respiratory disease, nasal swab samples were collected from cows with clinical signs of BRD and evaluated using PCR and RT-PCR for nucleic acid detection of the main BRD etiological agents, including Mycoplasma bovis, Mannheimia haemolytica, Pasteurella multocida, Histophilus somni, bovine respiratory syncytial virus, bovine coronavirus, bovine viral diarrhea virus, bovine alphaherpesvirus 1, and bovine parainfluenza virus 3. Only three microorganisms (M. bovis, H. somni, and P. multocida) were identified in both single and mixed infections. We concluded that 40.0% of the cows were infected with M. bovis and 75.0% with H. somni in herd A. Considering both single and mixed infections, the analyses performed in herd B showed that 87.5%, 25.0%, and 50.0% of the cows were infected with M. bovis, H. somni, and P. multocida, respectively. M. bovis and H. somni are considered fastidious bacteria and laboratory diagnosis is neglected. Subsequently, most clinical cases of mycoplasmosis and histophilosis in cattle remain undiagnosed. This study demonstrates the importance of M. bovis and H. somni infections in adult cows with BRD. These results highlight the importance of including these bacteria in the group of etiological agents responsible for the occurrence of BRD in cattle, especially in adult cows with unfavorable immunological conditions, such as recent calving and peak lactation.
Topics: Animals; Female; Cattle; Coinfection; Lactation; Cattle Diseases; Bacterial Infections; Bacteria; Pasteurella multocida
PubMed: 37917227
DOI: 10.1007/s42770-023-01165-1 -
Microbiology Resource Announcements Sep 2023A lack of whole genome sequences for spp. other than complicates their identification. Here, we present the genome sequence of 39324.S-11, isolated from a healthy...
A lack of whole genome sequences for spp. other than complicates their identification. Here, we present the genome sequence of 39324.S-11, isolated from a healthy calf on a feedlot in Saskatchewan, Canada, and compare it to ZY190616, which is currently the only other isolate of for which sequence is publicly available.
PubMed: 37555671
DOI: 10.1128/MRA.00456-23 -
Frontiers in Plant Science 2023Bovine respiratory disease (BRD) affects feedlot cattle across North America, resulting in economic losses due to animal treatment and reduced performance. In an effort...
Bovine respiratory disease (BRD) affects feedlot cattle across North America, resulting in economic losses due to animal treatment and reduced performance. In an effort to develop a vaccine candidate targeting a primary bacterial agent contributing to BRD, we produced a tripartite antigen consisting of segments of the virulence factor Leukotoxin A (LktA) and lipoprotein PlpE from , fused to a cholera toxin mucosal adjuvant (CTB). This recombinant subunit vaccine candidate was expressed in the leaves of plants, with accumulation tested in five subcellular compartments. The recombinant protein was found to accumulate highest in the endoplasmic reticulum, but targeting to the chloroplast was employed for scaling up production due the absence of post-translational modification while still producing feasible levels. Leaves were freeze dried, then orally administered to mice to determine its immunogenicity. Sera from mice immunized with leaf tissue expressing the recombinant antigen contained IgG antibodies, specifically recognizing both LktA and PlpE. These mice also had a mucosal immune response to the CTB+LktA+PlpE protein as measured by the presence of LktA- and PlpE-specific IgA antibodies in lung and fecal material. Moreover, the antigen remained stable at room temperature with limited deterioration for up to one year when stored as lyophilized plant material. This study demonstrated that a recombinant antigen expressed in plant tissue elicited both humoral and mucosal immune responses when fed to mice, and warrants evaluation in cattle.
PubMed: 37790785
DOI: 10.3389/fpls.2023.1251046