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Scientific Reports Oct 2022Many proteins of the Repeats in Toxins (RTX) protein family are toxins of Gram-negative pathogens including hemolysin A (HlyA) of uropathogenic E. coli. RTX proteins are...
Many proteins of the Repeats in Toxins (RTX) protein family are toxins of Gram-negative pathogens including hemolysin A (HlyA) of uropathogenic E. coli. RTX proteins are secreted via Type I secretion systems (T1SS) and adopt their native conformation in the Ca-rich extracellular environment. Here we employed the E. coli HlyA T1SS as a heterologous surrogate system for the RTX toxin MbxA from the bovine pathogen Moraxella bovis. In E. coli the HlyA system successfully activates the heterologous MbxA substrate by acylation and secretes the precursor proMbxA and active MbxA allowing purification of both species in quantities sufficient for a variety of investigations. The activating E. coli acyltransferase HlyC recognizes the acylation sites in MbxA, but unexpectedly in a different acylation pattern as for its endogenous substrate HlyA. HlyC-activated MbxA shows host species-independent activity including a so-far unknown toxicity against human lymphocytes and epithelial cells. Using live-cell imaging, we show an immediate MbxA-mediated permeabilization and a rapidly developing blebbing of the plasma membrane in epithelial cells, which is associated with immediate cell death.
Topics: Humans; Acyltransferases; Bacterial Proteins; Escherichia coli; Escherichia coli Proteins; Hemolysin Proteins; Moraxella bovis; Type I Secretion Systems
PubMed: 36280777
DOI: 10.1038/s41598-022-22480-x -
The Veterinary Clinics of North... Jul 2021Infectious bovine keratoconjunctivitis (IBK) is a multifactorial disease complex caused by opportunistic pathogens, classically those members of the genus Moraxella.... (Review)
Review
Infectious bovine keratoconjunctivitis (IBK) is a multifactorial disease complex caused by opportunistic pathogens, classically those members of the genus Moraxella. However, IBK in some situations is associated with other potentially pathogenic agents, which include Mycoplasma bovoculi, Mycoplasma bovis, Ureaplasma diversum, bovine herpesviruses, and Chlamydia sp. Ocular infections that may resemble IBK are also caused by Listeria monocytogenes. These agents and their association with IBK are reviewed in this article.
Topics: Animals; Bacteria; Cattle; Cattle Diseases; Keratoconjunctivitis, Infectious; Moraxella; Virulence Factors
PubMed: 34049660
DOI: 10.1016/j.cvfa.2021.03.005 -
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 -
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 -
Journal of Microbiological Methods May 2019Infectious bovine keratoconjunctivitis (IBK), also known as pinkeye, is one of the most common eye diseases in cattle. Several pathogens have been associated with IBK...
Infectious bovine keratoconjunctivitis (IBK), also known as pinkeye, is one of the most common eye diseases in cattle. Several pathogens have been associated with IBK cases, however, Moraxella bovis, Moraxella bovoculi, Mycoplasma bovis, Mycoplasma bovoculi and bovine herpesvirus type 1 (BHV-1) are most frequently observed. A multiplex real-time PCR assay using two reactions was developed for the detection and differentiation of these five pathogens. Detection sensitivities of the multiplex assays were compared to singleplex reactions testing for the same targets. Correlation coefficients (R) of >0.99, and PCR efficiencies between 92 and 106% were demonstrated in all singleplex and multiplex real-time PCR reactions. The limits of detection (LOD) of multiplex assays for Moraxella bovis, Moraxella bovoculi, Mycoplasma bovis, Mycoplasma bovoculi and BHV-1 were 19, 23, 25, 24 and 26 copies per reaction, respectively. No cross amplification was observed for specificity testing of 179 IBK positive clinical samples and 55 non-target clinical samples. Percentage of clinical samples positive for Mycoplasma bovoculi, Moraxella bovoculi, Moraxella bovis, BHV-1 and Mycoplasma bovis were 88.8% (159/179), 75.9% (136/179), 60.3% (108/179), 11.7% (21/179) and 10.0% (18/179), respectively. Moraxella bovis, Moraxella bovoculi and Mycoplasma bovoculi were more prevalent than Mycoplasma bovis and BHV-1 in IBK samples collected from animals in this study population. Our data indicates that the multiplex real-time PCR panel assay is highly sensitive and highly specific for the detection and differentiation of the five major pathogens associated with bovine pinkeye.
Topics: Animals; Cattle; Cattle Diseases; Herpesvirus 1, Bovine; Keratoconjunctivitis; Moraxella bovis; Moraxellaceae Infections; Multiplex Polymerase Chain Reaction; Mycoplasma Infections; Mycoplasma bovis
PubMed: 30930057
DOI: 10.1016/j.mimet.2019.03.024 -
Veterinary World May 2021Infectious bovine keratoconjunctivitis (IBK; conjunctivitis) is a widespread eye disease in cattle. In 1960, the Gram-negative bacillus was discovered as one of IBK's...
BACKGROUND AND AIM
Infectious bovine keratoconjunctivitis (IBK; conjunctivitis) is a widespread eye disease in cattle. In 1960, the Gram-negative bacillus was discovered as one of IBK's etiological causal agents. This study aimed to clarify the epidemiological (epizootic) situation of cattle moraxellosis in the Republic of Kazakhstan. The study also maps the quantitative and qualitative indicators of the epidemiological (epizootic) process to develop more effective antiepizootic measures.
MATERIALS AND METHODS
We clinically examined both imported and local cattle species based on existing epidemiological (epizootological) units of economic entities in Kazakhstan. Then, we selected biomaterials for laboratory tests to screen for moraxellosis.
RESULTS
We clarified the epizootic situation for moraxellosis of cattle in Kazakhstan using data from the Meat Union of Kazakhstan, veterinary reports from the Veterinary Control and Surveillance Committee of the Ministry of Agriculture, Kazakhstan, and our results, obtained during visits to farms in the various regions of the republic.
CONCLUSION
Based on the data of the conducted studies, we developed epizootic visualization maps with quantitative indicators of the cattle moraxellosis epizootic-transfer processes within various regions of Kazakhstan for 2019. The data obtained from studies of the properties of the isolated cultures compared with the characteristics of reference strains gave grounds to classify them as belonging to the genus.
PubMed: 34220144
DOI: 10.14202/vetworld.2021.1380-1388 -
EFSA Journal. European Food Safety... Dec 2021In this opinion, the antimicrobial resistant bacteria responsible for transmissible diseases that constitute a threat to the health of cattle have been assessed. The...
In this opinion, the antimicrobial resistant bacteria responsible for transmissible diseases that constitute a threat to the health of cattle have been assessed. The assessment has been performed following a methodology based on information collected by an extensive literature review and expert judgement. Details of the methodology used for this assessment are explained in a separate opinion. A global state of play on antimicrobial resistance in clinical isolates of (non-VTEC) and is provided. Among those bacteria, EFSA identified and with ≥ 66% certainty as being the most relevant antimicrobial resistant bacteria in cattle in the EU based on the available evidence. The animal health impact of these most relevant bacteria, as well as their eligibility for being listed and categorised within the animal health law framework will be assessed in separate scientific opinions.
PubMed: 34938371
DOI: 10.2903/j.efsa.2021.6955 -
Metabolites Nov 2018: Tear film fluid serves as a dynamic barrier that both lubricates the eye and protects against allergens and infectious agents. However, a detailed analysis of a...
: Tear film fluid serves as a dynamic barrier that both lubricates the eye and protects against allergens and infectious agents. However, a detailed analysis of a bacteria-induced immune response on the tear film lipidome has not been undertaken. : We undertook a high-resolution mass spectrometry lipidomics analysis of endogenous anti-inflammatory and structural tear film lipids in bovine pink eye. : Bovine pink eye resulted in dramatic elevations in tear fluid levels of the anti-inflammatory lipids resolvin E2, cyclic phosphatidic acid 16:0, and cyclic phosphatidic acid 18:0. In addition, there were elevated levels of the structural lipids (O-acyl)-ω-hydroxy-fatty acids, cholesterol sulfate, ethanolamine plasmalogens, and sphingomyelins. Lipid peroxidation also was augmented in pink eye as evidenced by the hydroperoxy derivatives of ethanolamine plasmalogens. : Ocular infections with result in the induction of a number of endogenous anti-inflammatory lipids and augmentation of the levels of structural glycerophospholipids and sphingolipids. Increased levels of hydroperoxy glycerophospholipids also indicate that this bacterial infection results in lipid peroxidation.
PubMed: 30469369
DOI: 10.3390/metabo8040081 -
Carbohydrate Research Sep 2018The Gram-negative bovine pathogen Moraxella bovis is a causative agent of Infectious bovine keratoconjunctivitis, 'pink-eye' that affects cattle. Here we report that...
The Gram-negative bovine pathogen Moraxella bovis is a causative agent of Infectious bovine keratoconjunctivitis, 'pink-eye' that affects cattle. Here we report that strain L183/2 has the same capsular polysaccharide (CPS) of unsulfated chondroitin, as does strain Mb25, whereas strain Epp63 does not express CPS. NMR analysis of the oligosaccharides (OS) derived from the lipooligosaccharides (LOS) in these three strains by NMR has shown that strain Mb25 and Epp63 have the same OS structure with a terminal N-acetylgalactosamine ((1S)-GalaNAc) residue →4,6-linked. Strain L183/2 lacks the (1 S)-GalaNAc residue. The biological role of M. bovis LOS was assessed by comparing the LOS from strains Epp63, Mb25 and L183/2 and truncated Epp63 LOS variants. LOS truncation affected M. bovis growth rate, susceptibility to antibiotics, detergents, bovine serum bactericidal activity, endotoxicity and adherence to HeLa cells.
Topics: Animals; Cattle; Cell Adhesion; HeLa Cells; Humans; Moraxella bovis; Polysaccharides, Bacterial
PubMed: 30032028
DOI: 10.1016/j.carres.2018.07.002 -
Vaccine: X Dec 2023Infectious bovine keratoconjunctivitis (IBK; pinkeye) is generally considered to be caused by corneal infections with . Previous studies demonstrated that...
BACKGROUND
Infectious bovine keratoconjunctivitis (IBK; pinkeye) is generally considered to be caused by corneal infections with . Previous studies demonstrated that cytotoxin-specific mucosal immune responses in the bovine eye can be stimulated by intranasal vaccination with a recombinant cytotoxin subunit adjuvanted with polyacrylic acid.
METHODS
A randomized controlled field trial (two-arm parallel design with blinding) was conducted in beef steers in Northern California to determine if this vaccine could prevent naturally occurring IBK and/or reduce morbidity rates associated with this disease. Beef steers were vaccinated intranasally on days 0 and 21 with either a recombinant cytotoxin subunit adjuvanted with polyacrylic acid (Vaccine group) or adjuvant alone (Control group). Eye examinations were performed on all steers every 7 days for 16 weeks to document the occurrence of IBK and to determine sizes of corneal ulcers. Serum and tear samples were collected on days 0, 42, and 112 from a subset of animals to measure changes in systemic and ocular immune responses to cytotoxin.
RESULTS
The cumulative proportion of steers that developed IBK after 16 weeks did not differ between groups. Variables related to disease severity were numerically lower in steers that received the experimental vaccine. IBK-affected Vaccine group steers had a significantly lower number of observation weeks with severe ulcers versus Control group steers. Cytotoxin-specific tear IgA was significantly higher in Vaccine group compared to Control group steers on day 112. Although the proportion of animals that developed corneal ulcers associated with IBK did not differ between groups, the lowered metrics of disease severity in vaccinated steers suggests that intranasal vaccination with recombinant cytotoxin can reduce the severity of IBK in cattle.
PubMed: 37693844
DOI: 10.1016/j.jvacx.2023.100378