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Journal of Microbiological Methods Aug 2017Mannheimia haemolytica is an important respiratory pathogen of ruminants. Of the 12 capsular serovars identified, 1 and 6 are most frequently associated with disease in...
Mannheimia haemolytica is an important respiratory pathogen of ruminants. Of the 12 capsular serovars identified, 1 and 6 are most frequently associated with disease in cattle, while 2 is largely a commensal. Comparative analysis of 24 M. haemolytica genomes was used to identify unique genes associated with capsular polysaccharide synthesis as amplification targets in a multiplex PCR assay to discriminate between serotype 1, 2, and 6 strains. The specificity of serotype specific gene targets was evaluated against 47 reference strains representing 12 known serovars of M. haemolytica and 101 field isolates identified through antisera agglutination as serotypes 1, 2, or 6. The results suggest this simple and cost-effective serotype specific PCR assay can be used as an alternative to agglutination based techniques to serotype the majority of M. haemolytica collected from bovines, thus averting the need to use animals and invest in expensive sera development for agglutination assays. In addition, the gene targets identified in this study can be used in silico to identify serotype 1, 2, and 6 strains in sequenced M. haemolytica isolates without the need for culture based analysis.
Topics: Animals; Bacterial Capsules; Cattle; Cattle Diseases; Genes, Bacterial; Genome, Bacterial; Mannheimia haemolytica; Multiplex Polymerase Chain Reaction; Pasteurellaceae Infections; Serogroup; Serotyping
PubMed: 28551457
DOI: 10.1016/j.mimet.2017.05.010 -
Veterinary Microbiology Mar 2012The aim of this study was to analyse a florfenicol-resistant Mannheimia haemolytica isolated from a calf to determine the genetic basis of its florfenicol-resistance....
The aim of this study was to analyse a florfenicol-resistant Mannheimia haemolytica isolated from a calf to determine the genetic basis of its florfenicol-resistance. The antimicrobial susceptibility and plasmid content of the isolate were determined. A florfenicol resistant plasmid carrying the floR gene was identified by PCR and transformed into Escherichia coli JM109 and HB101 strains. The plasmid was then mapped and sequenced completely. The isolate was resistant to chloramphenicol, florfenicol, oxytetracycline, kanamycin, dihydrostreptomycin, nalidixic acid, ampicillin, and amoxicillin; it carried a floR plasmid of 7.7kb, designated pMH1405. The mobilisation and replication genes of pMH1405 showed extensive similarity to the 5.1-kb pDN1 plasmid from Dichelobacter nodosus and the 10.8-kb pCCK381 plasmid from Pasteurella multocida. An adjacent 2.4-kb segment was highly homologous to the TnfloR region of the E. coli BN10660 plasmid. A plasmid-mediated floR gene was responsible for florfenicol resistance in the bovine respiratory tract pathogen M. haemolytica. The pMH1405 plasmid is the smallest floR-carrying plasmid reported to date. To the best of our knowledge, this is the first report of a florfenicol-resistant gene in M. haemolytica.
Topics: Animals; Anti-Bacterial Agents; Cattle; Chloramphenicol; Drug Resistance, Bacterial; Mannheimia haemolytica; Pasteurellosis, Pneumonic; Plasmids; Thiamphenicol
PubMed: 22019290
DOI: 10.1016/j.vetmic.2011.09.033 -
Clinical and Vaccine Immunology : CVI Dec 2011We previously identified Mannheimia haemolytica outer membrane proteins (OMPs) that may be important immunogens by using immunoproteomic analyses. Genes for serotype...
We previously identified Mannheimia haemolytica outer membrane proteins (OMPs) that may be important immunogens by using immunoproteomic analyses. Genes for serotype 1-specific antigen (SSA-1), OmpA, OmpP2, and OmpD15 were cloned and expressed, and recombinant proteins were purified. Objective 1 of this study was to demonstrate immunogenicity of the four recombinant OMPs in mice and cattle. Objective 2 was to determine if the addition of individual recombinant OMPs or combinations of them would modify immune responsiveness of mice to the recombinant chimeric protein SAC89, containing the main epitope from M. haemolytica outer membrane lipoprotein PlpE and the neutralizing epitope of M. haemolytica leukotoxin. Mice vaccinated with recombinant OmpA (rOmpA), rSSA-1, rOmpD15, and rOmpP2 developed significant antibody responses to M. haemolytica outer membranes and to the homologous recombinant OMP. Cattle vaccinated with rOmpA and rSSA-1 developed significant antibodies to M. haemolytica outer membranes by day 28, whereas cattle vaccinated with rOmpD15 and rOmpP2 developed only minimal responses. Sera from cattle vaccinated with each of the recombinant proteins stimulated complement-mediated killing of the bacterium. Concurrent vaccination with SAC89 plus any of the four rOMPs singly resulted in increased endpoint anti-SAC89 titers, and for the SAC89/rSSA-1 vaccinees, the response was increased significantly. In contrast, the SAC89/P2/SSA-1 and SAC89/OmpA/P2/D15/SSA-1 combination vaccines resulted in significant decreases in anti-SAC89 antibodies compared to SAC89 vaccination alone. In conclusion, under the conditions of these experiments, vaccination of mice and cattle with rOmpA and rSSA-1 stimulated high antibody responses and may have protective vaccine potential.
Topics: Animals; Antibodies, Bacterial; Antigens, Bacterial; Bacterial Outer Membrane Proteins; Bacterial Vaccines; Blood Bactericidal Activity; Cattle; Cloning, Molecular; Complement System Proteins; Gene Expression; Mannheimia haemolytica; Mice; Microbial Viability; Recombinant Proteins
PubMed: 21976226
DOI: 10.1128/CVI.05332-11 -
Veterinary Microbiology Nov 2011Mannheimia haemolytica is known to be an important cause of intramammary infection in sheep. It usually causes severe clinical mastitis, followed by toxaemia and... (Review)
Review
Mannheimia haemolytica is known to be an important cause of intramammary infection in sheep. It usually causes severe clinical mastitis, followed by toxaemia and gangrenous necrosis of the udder. However there are limited data available on the epidemiology and pathogenesis of mastitis associated with Mannheimia species. These organisms can be more significant as a cause of mastitis than Staphylococcus aureus in some flocks. Some data suggest the possibility of horizontal transmission of Mannheimia species between ewes via lamb sucking. There is no vaccine available for prevention, and the sudden onset of mastitis and its peracute nature renders most treatments unsuccessful. This review examines the significance of the species within this genus in sheep mastitis.
Topics: Animals; Female; Mammary Glands, Animal; Mannheimia; Mannheimia haemolytica; Mastitis; Sheep; Sheep Diseases; Sheep, Domestic; Virulence Factors
PubMed: 21511411
DOI: 10.1016/j.vetmic.2011.03.024 -
Australian Veterinary Journal Jan 2021This study evaluates the effects of respiratory vaccines on health and growth rates in cattle placed in local backgrounding facilities then feedlots.
Health and production effects of killed vaccines against Mannheimia haemolytica, bovine viral diarrhoea virus and bovine herpesvirus 1, in locally backgrounded feedlot cattle.
OBJECTIVES
This study evaluates the effects of respiratory vaccines on health and growth rates in cattle placed in local backgrounding facilities then feedlots.
METHODS
A total of 7011 cattle entering backgrounding facilities contiguous with six feedlots in Australia were allocated to eight respiratory vaccine categories, including an untreated control category. The vaccines, against Mannheimia haemolytica, bovine viral diarrhoea virus and bovine herpesvirus 1, were administered in various combinations at backgrounding facility entry and subsequent feedlot entry. Cattle were held in the backgrounding facilities for a minimum of 28 days.
RESULTS
During their feedlot phase, 3.7% of study animals were detected with bovine respiratory disease (BRD). BRD sub hazard was lowest in cattle vaccinated with Bovilis MH + infectious bovine rhinotracheitis® (sub hazards ratio: 0.47; 95% confidence interval: 0.27-0.83; P = 0.010), and point estimates for other vaccine combinations did not differ (P > 0.10) from controls. Six of the respiratory vaccine combinations decreased growth rate during backgrounding relative to untreated controls (P ≤ 0.003). Overall, the feedlot growth rate was not significantly affected by the vaccine category (overall Wald P = 0.191).
CONCLUSIONS
Use of these respiratory vaccines in cattle held for at least 28 days in backgrounding facilities contiguous with their feedlots before feedlot entry reduces growth rate during the backgrounding period and does not result in large beneficial effects on either BRD risk or average daily live weight gain during the feedlot phase.
Topics: Animals; Australia; Cattle; Cattle Diseases; Diarrhea; Herpesvirus 1, Bovine; Mannheimia haemolytica; Vaccines, Inactivated
PubMed: 32671826
DOI: 10.1111/avj.12995 -
Veterinary Microbiology Jan 2002Trehalose-negative strains of the Pasteurella haemolytica complex have recently been transferred to a new genus, Mannheimia. This genus presently consists of five named...
Trehalose-negative strains of the Pasteurella haemolytica complex have recently been transferred to a new genus, Mannheimia. This genus presently consists of five named species: M. haemolytica, M. glucosida, M. granulomatis, M. ruminalis and M. varigena. The purpose of this study was to investigate the occurrence of these species and lesions associated with these isolates in Denmark. In all 106 M. haemolytica-like strains isolated from pathological material from cattle, sheep, pigs and hares submitted to the Danish Veterinary Laboratory between 1994 and 1998 were investigated. Phenotypic characterization and ribotyping were used for identification in addition to sequencing of the 16S rRNA genes for selected strains. The species allocation was determined by comparison to results from a previous polyphasic taxonomic study. Seventy-one percent of the strains belonged to M. haemolytica, 18% to M. varigena and 8% to unnamed groups within the genus Mannheimia. Single isolates identified as M. glucosida and P. trehalosi, respectively, were detected. Two isolates belonged to M. granulomatis. Forty-three percent of the strains belonged to serotype 1, 41% were untypeable, while the rest belonged to serotypes 2, 7, 9, and 16. The present investigation also showed that a simplified phenotypic characterization using Diatabs Diagnostic Tablets (Rosco, Denmark) represents a useful method for obtaining a quick and reliable species identification. Finally, the investigation confirmed that serotyping does not represent a reliable method for species identification. The heterogeneity of species associated with bovine "pasteurellosis" should be considered in future studies to improve our understanding of the pathogenesis of pneumonic disease.
Topics: Animals; Cattle; DNA, Bacterial; Denmark; Genotype; Lagomorpha; Mannheimia haemolytica; Pasteurella Infections; Phenotype; Phylogeny; RNA, Ribosomal, 16S; Respiratory Tract Diseases; Ribotyping; Sheep; Swine
PubMed: 11731163
DOI: 10.1016/s0378-1135(01)00439-4 -
Nutrients Oct 2021Emerging antimicrobial-resistant pathogens highlight the importance of developing novel interventions. Here, we investigated the anti-inflammatory properties of...
Emerging antimicrobial-resistant pathogens highlight the importance of developing novel interventions. Here, we investigated the anti-inflammatory properties of Fructo-oligosaccharides (FOS) in calf lung infections and in airway epithelial cells stimulated with pathogens, and/or bacterial components. During a natural exposure, 100 male calves were fed milk replacer with or without FOS for 8 weeks. Then, immune parameters and cytokine/chemokine levels in the bronchoalveolar lavage fluid (BALF) and blood were measured, and clinical scores were investigated. Calf primary bronchial epithelial cells (PBECs) and human airway epithelial cells (A549) were treated with , lipopolysaccharides (LPS), and/or flagellin, with or without FOS pretreatment. Thereafter, the cytokine/chemokine levels and epithelial barrier function were examined. Relative to the control (naturally occurring lung infections), FOS-fed calves had greater macrophage numbers in BALF and lower interleukin (IL)-8, IL-6, and IL-1β concentrations in the BALF and blood. However, FOS did not affect the clinical scores. At slaughter, FOS-fed calves had a lower severity of lung lesions compared to the control. Ex vivo, FOS prevented -induced epithelial barrier dysfunction. Moreover, FOS reduced - and flagellin-induced (but not LPS-induced) IL-8, TNF-α, and IL-6 release in PBECs and A549 cells. Overall, FOS had anti-inflammatory properties during the natural incidence of lung infections but had no effects on clinical symptoms.
Topics: Animals; Anti-Inflammatory Agents; Cattle; Disease Models, Animal; Epithelial Cells; Lung; Mannheimia haemolytica; Oligosaccharides; Pasteurella multocida; Pneumonia of Calves, Enzootic
PubMed: 34684515
DOI: 10.3390/nu13103514 -
Glycoconjugate Journal Aug 2011Inner core lipopolysaccharide (LPS) has been shown to be conserved in the majority of veterinary strains from the species Mannheimia haemolytica, Actinobacillus...
Inner core lipopolysaccharide (LPS) has been shown to be conserved in the majority of veterinary strains from the species Mannheimia haemolytica, Actinobacillus pleuropneumoniae and Pasteurella multocida and as such is being considered as a possible vaccine antigen. The proof-in-principle that a LPS-based antigen could be considered as a vaccine candidate has been demonstrated from studies with monoclonal antibodies raised to the inner core LPS of Mannheimia haemolytica, which were shown to be both bactericidal and protective in a mouse model of disease. In this study we confirm and extend the candidacy of the inner core LPS by demonstrating that it is possible to elicit functional antibodies against Mannheimia haemolytica wild-type strains following immunisation of rabbits with glycoconjugates elaborating the conserved inner core LPS antigen. The present study describes a conjugation strategy that uses amidases produced by Dictyostelium discoideum, targeting the amino functionality created by the amidase activity as the attachment point on the LPS molecule. To protect the amino functionality on the phosphoethanolamine (PEtn) residue of the inner core, we developed a novel blocking and unblocking strategy with t-butyl oxycarbonyl. A maleimide-thiol linker strategy with the thiol linker on the carboxyl residues of the carrier protein and the maleimide linker on the carbohydrate resulted in a high loading of carbohydrates per carrier protein. Immunisation derived antisera from rabbits recognised fully extended Mannheimia haemolytica LPS and whole cells from serotypes 1 and 2, despite a somewhat immunodominant response to the linkers also being observed. Moreover, bactericidal activity was demonstrated to a strain elaborating the immunising carbohydrate antigen and crucially to wild-type cells of serotypes 1 and 2, thus further supporting the consideration of inner core LPS as a potential vaccine antigen to combat disease caused by Mannheimia haemolytica.
Topics: Animals; Bacterial Vaccines; Blotting, Western; Electrophoresis, Polyacrylamide Gel; Enzyme-Linked Immunosorbent Assay; Glycoconjugates; Lipopolysaccharides; Mannheimia haemolytica; Mice; Pasteurellaceae Infections; Rabbits; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Vaccines
PubMed: 21701793
DOI: 10.1007/s10719-011-9339-0 -
Animal Health Research Reviews Dec 2014Bovine respiratory disease complex (BRDC) is a major animal health and economic issue that affects cattle industries worldwide. Within the USA, the beef cattle industry...
Bovine respiratory disease complex (BRDC) is a major animal health and economic issue that affects cattle industries worldwide. Within the USA, the beef cattle industry loses up to an estimated 1 billion dollars a year due to BRDC. There are many contributors to BRDC, including environmental stressors and viral and/or bacterial infections. One species of bacteria in particular, Mannheimia haemolytica, is recognized as the major cause of severe fibrinonecrotic pneumonia in cattle. M. haemolytica is an opportunistic pathogen that normally populates the upper respiratory tract of cattle, and invades the lower respiratory tract in stressed and/or virally infected cattle by mechanisms that are not completely understood. However, not all M. haemolytica appear to be equally pathogenic to cattle. Thus, a test could be developed to distinguish M. haemolytica genetic subtypes by their propensity to cause respiratory disease, allowing isolation and/or treatment of cattle harboring strains with an increased propensity to cause disease. To that end, the genomes of over 300 M. haemolytica strains are being sequenced.
Topics: Animals; Base Sequence; Bovine Respiratory Disease Complex; Cattle; Chromosome Mapping; Genetic Variation; Mannheimia haemolytica; Pasteurellosis, Pneumonic; Serotyping
PubMed: 25381881
DOI: 10.1017/S1466252314000188 -
Journal of Microbiological Methods Apr 2010Mannheimia haemolytica is an opportunistic pathogen that can cause fibrinonecrotic pneumonia in cattle and is the main bacterial agent implicated in bovine respiratory...
Mannheimia haemolytica is an opportunistic pathogen that can cause fibrinonecrotic pneumonia in cattle and is the main bacterial agent implicated in bovine respiratory disease-complex (BRD). Despite its economic importance to the cattle industry, few studies have characterized the genetic nature of M. haemolytica and none have genotyped isolates from feedlots. Identifying and monitoring genetic variants of M. haemolytica is important to understanding the etiology of BRD in cattle. We investigated the capacity of three genotyping techniques (BOX-PCR, (GTG)(5)-PCR and PFGE analysis of SalI-restricted DNA) to discriminate among 24 reference strains from the family Pasteurellaceae and 40 M. haemolytica isolates collected from feedlot cattle. From cluster analysis of the M. haemolytica isolates, PFGE was revealed as most discriminating, followed by BOX-PCR and then (GTG)(5)-PCR (Simpson's diversity index >0.98, 0.82, and 0.72, respectively). Of these methods, PFGE also had the greatest mean repeatability (0.96). The PFGE and BOX-PCR assays grouped all M. haemolytica in a single cluster but only BOX-PCR and (GTG)(5)-PCR grouped the Mannheimia glucosida and Mannheimia ruminalis strains together. Refinement of genotyping procedures for M. haemolytica could offer new insight into the etiology of this pathogen in BRD.
Topics: Animals; Bacterial Typing Techniques; Cattle; Cluster Analysis; DNA Fingerprinting; DNA, Bacterial; Electrophoresis, Gel, Pulsed-Field; Genotype; Mannheimia haemolytica; Pneumonia of Calves, Enzootic; Polymerase Chain Reaction
PubMed: 20122972
DOI: 10.1016/j.mimet.2010.01.020