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Biological Trace Element Research May 2016Copper (Cu) deficiency increases occurrence of certain infectious diseases in animals, including infectious keratoconjunctivitis in bovines, a bacterial ocular...
Superoxide Dismutase Activity, Hydrogen Peroxide Steady-State Concentration, and Bactericidal and Phagocytic Activities Against Moraxella bovis, in Neutrophils Isolated from Copper-Deficient Bovines.
Copper (Cu) deficiency increases occurrence of certain infectious diseases in animals, including infectious keratoconjunctivitis in bovines, a bacterial ocular inflammation caused by Moraxella bovis. Neutrophil leukocytes constitute the first phagocytic cells to arrive at infection sites for bacterial neutralization. The objective of this work was to evaluate whether the functionality of neutrophils against M. bovis is impaired in experimentally induced Cu deficiency in bovines using high molybdenum and sulfur levels in the diet. The Cu tissue values and the periocular achromotrichia observed in +Mo animals showed that the clinic phase of Cu deficiency was reached in this group. Instead, +Cu animals have not evidenced clinical signs or biochemical parameters of hypocuprosis. On the basis of our observations, we concluded that Cu deficiency has no effect on phagocytic and bactericidal activities of neutrophils against M. bovis. However, superoxide dismutase activity and peroxide hydrogen generation were significantly different between groups. Therefore, additional research to explain these results is merited to fully characterize the consequences of Cu status on the risk for infections under field conditions.
Topics: Animals; Anti-Bacterial Agents; Cattle; Cell Survival; Copper; Enzyme Activation; Hydrogen Peroxide; Moraxella bovis; Neutrophils; Phagocytosis; Superoxide Dismutase
PubMed: 26400649
DOI: 10.1007/s12011-015-0505-2 -
Brazilian Journal of Microbiology :... Jun 2015The aim of this study was to determine the differences in the antimicrobial susceptibility profiles of Moraxella bovis, M. bovoculi and M. ovis. Thirty-two strains of...
The aim of this study was to determine the differences in the antimicrobial susceptibility profiles of Moraxella bovis, M. bovoculi and M. ovis. Thirty-two strains of Moraxella spp. isolated from cattle and sheep with infectious keratoconjunctivitis were tested via broth microdilution method to determine their susceptibility to ampicillin, cefoperazone, ceftiofur, cloxacillin, enrofloxacin, florfenicol, gentamicin, neomycin, oxytetracycline and penicillin. The results demonstrated that Moraxella spp. strains could be considered sensitive for most of the antimicrobials tested in this study, but differences between the antimicrobial susceptibility profiles of these three Moraxella species were found. M. bovis might differ from other species due to the higher MIC and MBC values it presented.
Topics: Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; Keratoconjunctivitis, Infectious; Microbial Sensitivity Tests; Microbial Viability; Moraxella; Moraxellaceae Infections; Sheep; Sheep Diseases
PubMed: 26273272
DOI: 10.1590/S1517-838246220140058 -
Veterinary Microbiology Aug 2015The cytotoxin A (MbxA) is one of the main virulence factors of Moraxella bovis involved in the pathogenesis of infectious bovine keratoconjunctivitis (IBK). Moraxella...
The cytotoxin A (MbxA) is one of the main virulence factors of Moraxella bovis involved in the pathogenesis of infectious bovine keratoconjunctivitis (IBK). Moraxella ovis and Moraxella bovoculi, suspected to be associated with infectious keratitis in sheep and cattle respectively, also have a gene that encodes the cytotoxin A (movA and mbvA, respectively). The aim of this study was to determine the molecular sequence of the 3' region of the cytotoxin gene of Moraxella spp. strains isolated from clinical cases to establish phylogenetic and evolutionary comparisons. PCR amplification, nucleotide sequencing (nt) and amino acid (aa) sequence prediction were performed, followed by the sequences comparison, identity level calculation and selective pressure analysis. The phylogenetic reconstruction based on nt and aa sequences clearly differentiate M. bovis (n=15), M. bovoculi (n=11) and M. ovis (n=7) and their respective reference strains. An alignment of 843nt revealed high similarity within bacterial species (MbxA=99.9% nt and aa; MbvA=99.3% nt and 98.8% aa; MovA=99.5% nt and 99.3% aa). The similarity of partial sequences (nt 1807-2649) of MbxA in relation to MbvA and MovA ranged from 76.3 to 78.5%; similarity between MbvA and MovA ranged from 95.7 to 97.5%. A negative selection on mbvA and movA sequences was revealed by the molecular evolution analysis. The phylogenetic analysis of movA and mbvA allowed different strains of Moraxella spp. to be grouped according to the period of isolation. Sequence analysis of cytotoxin may provide insights into genetic and evolutionary relationships and into the genetic/molecular basis of Moraxella spp.
Topics: Amino Acid Sequence; Animals; Base Sequence; Cattle; Cattle Diseases; Cytotoxins; Genetic Variation; Geography; Keratoconjunctivitis, Infectious; Molecular Sequence Data; Moraxella; Moraxella bovis; Moraxellaceae Infections; Phylogeny; Sequence Analysis, DNA; Sheep; Sheep Diseases
PubMed: 26036790
DOI: 10.1016/j.vetmic.2015.05.025 -
Nucleic Acids Research Apr 2015DNA-dependent T7 RNA polymerase (T7 RNAP) is the most powerful tool for both gene expression and in vitro transcription. By using a Next Generation Sequencing (NGS)...
DNA-dependent T7 RNA polymerase (T7 RNAP) is the most powerful tool for both gene expression and in vitro transcription. By using a Next Generation Sequencing (NGS) approach we have analyzed the polymorphism of a T7 RNAP-generated mRNA pool of the mboIIM2 gene. We find that the enzyme displays a relatively high level of template-dependent transcriptional infidelity. The nucleotide misincorporations and multiple insertions in A/T-rich tracts of homopolymers in mRNA (0.20 and 0.089%, respectively) cause epigenetic effects with significant impact on gene expression that is disproportionally high to their frequency of appearance. The sequence-dependent rescue of single and even double InDel frameshifting mutants and wild-type phenotype recovery is observed as a result. As a consequence, a heterogeneous pool of functional and non-functional proteins of almost the same molecular mass is produced where the proteins are indistinguishable from each other upon ordinary analysis. We suggest that transcriptional infidelity as a general feature of the most effective RNAPs may serve to repair and/or modify a protein function, thus increasing the repertoire of phenotypic variants, which in turn has a high evolutionary potential.
Topics: Amino Acids; DNA Repair; DNA-Directed RNA Polymerases; Epigenesis, Genetic; Frameshifting, Ribosomal; INDEL Mutation; Methyltransferases; Moraxella bovis; Phenotype; RNA Editing; RNA, Messenger; Viral Proteins
PubMed: 25824942
DOI: 10.1093/nar/gkv269 -
The Veterinary Clinics of North... Mar 2015As is the case for controlling other infectious livestock diseases, the most successful efforts to control infectious bovine keratoconjunctivitis (IBK) will include... (Review)
Review
As is the case for controlling other infectious livestock diseases, the most successful efforts to control infectious bovine keratoconjunctivitis (IBK) will include consideration of the host, the environment, herd management, and ongoing surveillance even after the immediate crisis has passed. Research over many years has led to the discovery of a variety of antibiotic treatments and antibiotic regimens that can be effective against IBK. The discoveries of Mor bovoculi and reports of IBK associated with Mycoplasma spp without concurrent Mor bovis or Mor bovoculi have raised new questions into the roles that other organisms may play in IBK pathogenesis.
Topics: Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; Dairying; Female; Keratoconjunctivitis, Infectious; Moraxella; Moraxellaceae Infections
PubMed: 25576389
DOI: 10.1016/j.cvfa.2014.11.006 -
F1000Research 2015Infectious bovine keratoconjunctivitis (IBK) is a common corneal disease of calves that adversely affects animal welfare by causing pain and weight loss. Identifying...
Infectious bovine keratoconjunctivitis (IBK) is a common corneal disease of calves that adversely affects animal welfare by causing pain and weight loss. Identifying behavioral indicators of pain and sickness in calves with IBK is necessary for designing studies that aim to identify effective means of pain mitigation. Consistent with principles of the 3Rs for animal use in research, data from a randomized blinded challenge study was used to identify and describe variation of behaviors that could serve as reliable indicators of pain and sickness in calves with corneal injuries. Behavioral observations were collected from 29 Holstein calves 8 to 12 weeks of age randomly allocated to one of three treatments: (1) corneal scarification only, (2) corneal scarification with inoculation with Moraxella bovoculi and (3) corneal scarification with inoculation with Moraxella bovis. Behavior was continuously observed between time 1230 - 1730 h on day -1 (baseline time period) and day 0 (scarification time period). Corneal scarification and inoculation occurred between 0800 - 1000 h on day 0. Frequency of head-directed behaviors (head shaking, head rubbing, head scratching) and durations of head rubbing, feeding, standing with head lifted, lying with head lifted and sleeping were compared between study days and groups. Following scarification, the frequency of head-directed behavior significantly increased (p = 0.0001), as did duration of head rubbing (p=0.02). There was no significant effect of trial, trial day, treatment or treatment-day interaction on other behaviors studied. Our study demonstrated that head-directed behavior, such as head shaking, rubbing and scratching, was associated with scarification of eyes using an IBK challenge model, but sickness behavior was not observed.
PubMed: 26949517
DOI: 10.12688/f1000research.6649.1 -
Veterinary Journal (London, England :... Jan 2015Infectious bovine keratoconjunctivitis (IBK) has significant economic consequences and a detrimental impact on animal welfare. Although Moraxella (Mor.) bovis is the...
Infectious bovine keratoconjunctivitis (IBK) has significant economic consequences and a detrimental impact on animal welfare. Although Moraxella (Mor.) bovis is the primary causative agent, the role of other bacteria, such as Mor. ovis, Mor. bovoculi and Mycoplasma (Myc.) bovoculi, is not well understood. To assess the prevalence of infection with these organisms, and to correlate this with outbreaks of IBK, conjunctival samples from four herds of cattle in Germany of differing IBK status were examined. Herds were selected to represent a hypothetical course of IBK ranging from the pre-outbreak stage (herd 1), to the acute disease stage (herd 2), to a stage where treatment had ceased (herd 3). Unaffected animals were also included (herd 4). To facilitate effective, sensitive sample analysis, a new real-time PCR for Myc. bovoculi was developed and used in concert with established real-time PCR protocols for Myc. bovis and Moraxella spp. Herds 1 and 2 showed similarly high rates of detection for Myc. bovoculi (92.5% and 84.0%, respectively), whereas herds 3 and 4 had a lower prevalence (35.5% and 26.2%, respectively). Mor. bovis and Mor. ovis were more prevalent in herd 1 (32.5% and 87.5%, respectively) and herd 2 (38% and 58%, respectively) than herd 3 (10.4% and 1.3%, respectively) and herd 4 (9.8% and 31.1%, respectively). Mor. bovoculi was the only pathogen that correlated with clinical signs of IBK; at 20% prevalence, it was almost exclusively detected in herd 2. The results indicate that herds with high Myc. bovoculi prevalence are more predisposed to outbreaks of IBK, possibly due to a synergistic interaction with Moraxella spp.
Topics: Animals; Cattle; Cattle Diseases; Germany; Keratoconjunctivitis; Moraxella; Moraxellaceae Infections; Mycoplasma; Mycoplasma Infections
PubMed: 25475168
DOI: 10.1016/j.tvjl.2014.11.009 -
Acta Crystallographica. Section F,... Oct 2014Pathogens have evolved a range of mechanisms to acquire iron from the host during infection. Several Gram-negative pathogens including members of the genera Neisseria...
Pathogens have evolved a range of mechanisms to acquire iron from the host during infection. Several Gram-negative pathogens including members of the genera Neisseria and Moraxella have evolved two-component systems that can extract iron from the host glycoproteins lactoferrin and transferrin. The homologous iron-transport systems consist of a membrane-bound transporter and an accessory lipoprotein. While the mechanism behind iron acquisition from transferrin is well understood, relatively little is known regarding how iron is extracted from lactoferrin. Here, the crystal structure of the N-terminal domain (N-lobe) of the accessory lipoprotein lactoferrin-binding protein B (LbpB) from the pathogen Neisseria meningitidis is reported. The structure is highly homologous to the previously determined structures of the accessory lipoprotein transferrin-binding protein B (TbpB) and LbpB from the bovine pathogen Moraxella bovis. Docking the LbpB structure with lactoferrin reveals extensive binding interactions with the N1 subdomain of lactoferrin. The nature of the interaction precludes apolactoferrin from binding LbpB, ensuring the specificity of iron-loaded lactoferrin. The specificity of LbpB safeguards proper delivery of iron-bound lactoferrin to the transporter lactoferrin-binding protein A (LbpA). The structure also reveals a possible secondary role for LbpB in protecting the bacteria from host defences. Following proteolytic digestion of lactoferrin, a cationic peptide derived from the N-terminus is released. This peptide, called lactoferricin, exhibits potent antimicrobial effects. The docked model of LbpB with lactoferrin reveals that LbpB interacts extensively with the N-terminal lactoferricin region. This may provide a venue for preventing the production of the peptide by proteolysis, or directly sequestering the peptide, protecting the bacteria from the toxic effects of lactoferricin.
Topics: Animals; Bacterial Proteins; Carrier Proteins; Cattle; Crystallography, X-Ray; Host-Pathogen Interactions; Humans; Hydrogen Bonding; Iron; Lactoferrin; Models, Molecular; Neisseria meningitidis; Protein Binding; Protein Interaction Domains and Motifs; Protein Structure, Quaternary; Protein Structure, Secondary
PubMed: 25286931
DOI: 10.1107/S2053230X14019372 -
Journal of Veterinary Diagnostic... Nov 2014Infectious bovine keratoconjunctivitis (IBK), also known as pinkeye, is the most costly eye disease of cattle. The principal etiologic agent of IBK is the Gram-negative...
Infectious bovine keratoconjunctivitis (IBK), also known as pinkeye, is the most costly eye disease of cattle. The principal etiologic agent of IBK is the Gram-negative bacterium Moraxella bovis. However, there have been reports of IBK outbreaks associated with Moraxella bovoculi. A retrospective study of IBK diagnostic cases submitted from July 1, 2010 through October 31, 2013 was conducted. Included in the study were 1,042 Moraxella isolates from 1,538 swabs of lacrimal secretions collected from 282 herds from 30 U.S. states. Moraxella isolates were identified to the species level and were composed of M. bovoculi (701 isolates), M. bovis (295 isolates), Moraxella ovis (5 isolates), and other Moraxella spp. (41). Minimum inhibitory concentrations required for 90% growth inhibition (MIC90) was calculated for representative isolates. The MIC90 values for both M. bovis and M. bovoculi were as follows: ampicillin and ceftiofur: ≤0.25 µg/ml; clindamycin: 2 µg/ml; danofloxacin and enrofloxacin: ≤0.12 µg/ml; florfenicol: 0.5 µg/ml; gentamicin: 1 µg/ml; neomycin: 4 µg/ml; tulathromycin: 2 µg/ml; and tylosin: 8 µg/ml. The MIC90 values for M. bovoculi included the following: chlortetracycline: ≤0.5 µg/ml; oxytetracycline: 4 µg/ml; penicillin: 0.25 µg/ml; spectinomycin: 32 µg/ml; sulfadimethoxine: >256 µg/ml; tiamulin: 1 µg/ml; and trimethoprim-sulfamethoxazole: 4 µg/ml. For M. bovis, MIC90 values included the following: chlortetracycline and oxytetracycline: 1 µg/ml; penicillin: ≤0.12 µg/ml; spectinomycin: 16 µg/ml; sulfadimethoxine: ≤256 µg/ml; tiamulin: ≤0.5 µg/ml; and trimethoprim-sulfamethoxazole: ≤2 µg/ml. The current work describes the frequency of isolation and differences in antimicrobial sensitivity observed among Moraxella isolates from case submissions.
Topics: Animals; Anti-Bacterial Agents; Cattle; Cattle Diseases; Drug Resistance, Microbial; Keratoconjunctivitis, Infectious; Moraxella; Moraxellaceae Infections; Nebraska; Polymerase Chain Reaction; Prevalence; Retrospective Studies
PubMed: 25261461
DOI: 10.1177/1040638714551403