-
The Veterinary Clinics of North... Jul 2021Pinkeye and infectious bovine keratoconjunctivitis (IBK) are imprecise terms that describe diverse ocular diseases. Moraxella bovis is the major causative agent of IBK;... (Review)
Review
Pinkeye and infectious bovine keratoconjunctivitis (IBK) are imprecise terms that describe diverse ocular diseases. Moraxella bovis is the major causative agent of IBK; however, disease epidemiology is not fully known. Not all cases referred to as pinkeye are of infectious origin, and not all IBK involve M bovis. This article suggests the term pinkeye should no longer be used, offers a case definition for IBK (a herd disease), and suggests describing ocular signs of IBK using existing clinical descriptors rather than resorting to novel scores. A new term "ocular moraxellosis" is defined as IBK from which Moraxella spp are demonstrated.
Topics: Animals; Cattle; Cattle Diseases; Keratoconjunctivitis, Infectious
PubMed: 34049656
DOI: 10.1016/j.cvfa.2021.03.001 -
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 -
Revista Argentina de Microbiologia 2024Infectious bovine keratoconjunctivitis (IBK) is an ocular disease that affects bovines and has significant economic and health effects worldwide. Gram negative bacteria...
Infectious bovine keratoconjunctivitis (IBK) is an ocular disease that affects bovines and has significant economic and health effects worldwide. Gram negative bacteria Moraxella bovis and Moraxella bovoculi are its main etiological agents. Antimicrobial therapy against IBK is often difficult in beef and dairy herds and, although vaccines are commercially available, their efficacy is variable and dependent on local strains. The aim of this study was to analyze for the first time the genomes of Uruguayan clinical isolates of M. bovis and M. bovoculi. The genomes were de novo assembled and annotated; the genetic basis of fimbrial synthesis was analyzed and virulence factors were identified. A 94% coverage in the reference genomes of both species, and more than 80% similarity to the reference genomes were observed. The mechanism of fimbrial phase variation in M. bovis was detected, and the tfpQ orientation of these genes confirmed, in an inversion region of approximately 2.18kb. No phase variation was determined in the fimbrial gene of M. bovoculi. When virulence factors were compared between strains, it was observed that fimbrial genes have 36.2% sequence similarity. In contrast, the TonB-dependent lactoferrin/transferrin receptor exhibited the highest percentage of amino acid similarity (97.7%) between strains, followed by cytotoxins MbxA/MbvA and the ferric uptake regulator. The role of these virulence factors in the pathogenesis of IBK and their potential as vaccine components should be explored.
Topics: Animals; Moraxella; Cattle; Moraxella bovis; Keratoconjunctivitis, Infectious; Cattle Diseases; Genome, Bacterial; Moraxellaceae Infections; Uruguay; Virulence Factors
PubMed: 38403533
DOI: 10.1016/j.ram.2023.12.003 -
Journal of Applied Microbiology Feb 2019This study aimed to verify the formation of biofilms by Moraxella bovis, Moraxella ovis and Moraxella bovoculi isolates from ruminants. In addition, the lysozyme...
AIMS
This study aimed to verify the formation of biofilms by Moraxella bovis, Moraxella ovis and Moraxella bovoculi isolates from ruminants. In addition, the lysozyme activity against the isolates of M. bovis, M. ovis and M. bovoculi in free form and in biofilms was determined.
METHODS AND RESULTS
In this study, 54 isolates of Moraxella sp. obtained from bovine and ovine clinical samples were evaluated in vitro for capacity of biofilm formation and lysozyme susceptibility in planktonic and sessile cells. In addition, biofilms produced by four Moraxella sp. isolates were visualized under scanning electron microscope (SEM). It was possible to demonstrate, for the first time, the ability to form biofilms by M. ovis and M. bovoculi. The isolates of Moraxella sp. have the capacity to form biofilms in different intensities, varying among weak, moderate and strong. It was verified that the lysozyme shows activity on Moraxella sp. in planktonic form. However, on biofilms there was a reduction in the production, but without impairing its formation, and on consolidated biofilms the lysozyme did not have the capacity to eradicate the preformed biofilms.
CONCLUSIONS
This work shows the capacity of biofilm formation by Moraxella sp. of veterinary importance. The lysozyme susceptibility of Moraxella sp. in planktonic form shows that this enzyme has bacteriostatic activity on this micro-organism and it reduced the production of biofilms.
SIGNIFICANCE AND IMPACT OF THE STUDY
Based on the results, it is possible to infer that the biofilm formation capacity by Moraxella sp. and the resistance to lysozyme concentrations equal to or greater than the physiological levels of the ruminant tear may be linked not only to the capacity to colonize the conjunctiva, but also to remain in this place even after healing of the lesions, being a reservoir of Moraxella sp. in a herd.
Topics: Animals; Biofilms; Cattle; Cattle Diseases; Keratoconjunctivitis, Infectious; Moraxella; Moraxella bovis; Moraxellaceae Infections; Muramidase; Sheep
PubMed: 30142702
DOI: 10.1111/jam.14086 -
The Veterinary Clinics of North... Jul 2021Studies have sought to develop effective vaccines against infectious bovine keratoconjunctivitis (IBK). Most research has focused on parenterally administered vaccines... (Review)
Review
Studies have sought to develop effective vaccines against infectious bovine keratoconjunctivitis (IBK). Most research has focused on parenterally administered vaccines against Moraxella bovis antigens; however, researchers have also included Moraxella bovoculi antigens in vaccines to prevent IBK. Critical knowledge gaps remain as to which Moraxella spp antigens might be completely protective, and whether systemic, mucosal, or both types of immune responses are required for protection against IBK associated with Moraxella spp. Immune responses to commensal Moraxella spp residing in the upper respiratory tract and eye have not been analyzed to determine if these responses control colonization or contribute to IBK.
Topics: Animals; Bacterial Vaccines; Cattle; Cattle Diseases; Keratoconjunctivitis, Infectious; Moraxella; Moraxella bovis; Moraxellaceae Infections
PubMed: 34049657
DOI: 10.1016/j.cvfa.2021.03.002 -
The Veterinary Clinics of North... Jul 2021Establishing causation, otherwise known as causal assessment, is a difficult task, made more difficult by the variety of causal assessment frameworks available to... (Review)
Review
Establishing causation, otherwise known as causal assessment, is a difficult task, made more difficult by the variety of causal assessment frameworks available to consider. In this article, Bradford Hill viewpoints are used to discuss the evidence base for Moraxella bovis and Moraxella bovoculi being component causes of infectious bovine keratoconjunctivitis. Each of the nine Bradford Hill viewpoints are introduced and explained: strength, consistency, specificity, temporality, biologic gradient, plausibility, coherence, experiment, and analogy. Examples of how the viewpoints have been applied for other causal relations are provided, and then the evidence base for M bovis and M bovoculi is discussed.
Topics: Animals; Cattle; Cattle Diseases; Keratoconjunctivitis, Infectious; Moraxella; Moraxella bovis; Moraxellaceae Infections
PubMed: 34049658
DOI: 10.1016/j.cvfa.2021.03.003 -
Genetics and Molecular Biology 2020The objective of this study was to evaluate the genetic diversity of Moraxella bovis and Moraxella bovoculi bacteria isolated from infectious bovine keratoconjunctivitis...
The objective of this study was to evaluate the genetic diversity of Moraxella bovis and Moraxella bovoculi bacteria isolated from infectious bovine keratoconjunctivitis (IBK) outbreaks in the state of Rio Grande do Sul, Brazil. The genetic diversity among Moraxella spp. was evaluated by RAPD-PCR, JWP1-JWOPA07-PCR, ERIC-PCR and by sequencing the 16S-23S intergenic regions. Based on the dendrogram, two genetically differentiated clades were observed; 14 isolates were classified as M. bovis and 17 as M. bovoculi. Genetic distances between the M. bovis samples ranged from 0.0379 to 0.4285, while for M. bovoculi the dissimilarities ranged from zero to 0.7297. Alternatively, based on sequencing analyses of the 16S-23S intergenic region, M. bovis and M. bovoculi isolates were grouped into the same two different clades, but it was not possible to differentiate between isolates within clades. PCR techniques were demonstrated to be a satisfactory tool to unravel the genetic variability among Moraxella spp., while sequencing of the 16S-23S intergenic region was only able to differentiate two species of the Moraxella genus. Despite sampling geographically close regions, we demonstrate considerable genetic diversity in M. bovis and M. bovoculi strains and genetically distinct M. bovis strains co-infecting the same animal.
PubMed: 32478794
DOI: 10.1590/1678-4685-GMB-2018-0380 -
The Veterinary Clinics of North... Jul 2021Pili and cytotoxins are important virulence factors and antigens for Moraxella spp. Local and systemic immunity may play a role in the body's response to infectious... (Review)
Review
Pili and cytotoxins are important virulence factors and antigens for Moraxella spp. Local and systemic immunity may play a role in the body's response to infectious bovine keratoconjunctivitis (IBK). No evidence exists that eliminating the carrier state for IBK is possible or beneficial. Evidence for efficacious transfer of passive immunity from dams to calves is conflicting. Autogenous vaccines and commercial vaccines for putative pathogens for IBK have not yet shown efficacy in blinded randomized field trials. Study design features, such as randomization, blinding, diagnostic criteria, and use of a placebo, reduce the risk of bias in vaccine studies for IBK.
Topics: Animals; Bacterial Vaccines; Cattle; Cattle Diseases; Keratoconjunctivitis, Infectious; Vaccination
PubMed: 34049664
DOI: 10.1016/j.cvfa.2021.03.009 -
Veterinary Microbiology Oct 2017Moraxella bovis is historically known as the primary agent of infectious bovine keratoconjunctivitis (IBK). However, Moraxella bovoculi and Moraxella ovis are also...
Moraxella bovis is historically known as the primary agent of infectious bovine keratoconjunctivitis (IBK). However, Moraxella bovoculi and Moraxella ovis are also reported to be involved in the pathogenesis of IBK, therefore, these three species should be included in the development of a new vaccine with a broad-spectrum protection against the disease natural challenge. In this study we investigated the antigenic properties of clinical isolates and reference strains of M. bovis, M. bovoculi and M. ovis using a novel in vitro approach for vaccine evaluation based on two techniques, flow cytometry and western blotting (WB). Here, we demonstrated that rabbit antisera produced against reference M. bovis strain and commercial bacterin showed low number of IgG with capacity to recognize a panel of heterologous strains composed by M. bovoculi and M. ovis. On the other hand, the antisera generated against two clinical isolates of M. ovis (Mov2 and Mov3) presented high cross-reactivity levels against all M. ovis and M. bovis strains evaluated. Similarly, the antisera against Mbv3 (clinical isolate of M. bovoculi) had high levels of IgG associated on the surface of all M. bovoculi strains and most of the M. ovis strains analyzed. The WB analysis demonstrated that Moraxella spp. has multiple immunogenic antigens and most of them are shared between the three species. Based on the cross-reactivity analysis and considering the relative number of IgGs associated on the bacterial surface, we suggest that a multivalent vaccine including Mbv3, Mov2 and Mov3 strains may provide a strong and broad protection against all strains involved in IBK outbreaks.
Topics: Animals; Antigens, Bacterial; Cattle; Cattle Diseases; Cross Reactions; Keratoconjunctivitis, Infectious; Moraxella; Moraxella bovis; Moraxellaceae Infections; Rabbits; Sheep; Sheep Diseases
PubMed: 29103697
DOI: 10.1016/j.vetmic.2017.08.016 -
Frontiers in Microbiology 2022() is regarded as a causative agent of infectious bovine keratoconjunctivitis (IBK), the most common ocular disease of cattle. Recently, whole genome sequencing...
() is regarded as a causative agent of infectious bovine keratoconjunctivitis (IBK), the most common ocular disease of cattle. Recently, whole genome sequencing identified the presence of two distinct genotypes within that differ in chromosome content, potential virulence factors, as well as prophage and plasmid profiles. It is unclear if the genotypes equally associate with IBK or if one is more likely to be isolated from IBK lesions. We utilized 39 strains of that had previously undergone whole genome sequencing and genotype classification to determine the utility of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) to accurately genotype strains. We successfully developed two biomarker models that accurately classified strains according to genotype with an overall accuracy of 85.8-100% depending upon the model and sample preparation method used. These models provide a practical tool to enable studies of genotype associations with disease, allow for epidemiological studies at the sub-species level, and can be used to enhance disease prevention strategies.
PubMed: 36569069
DOI: 10.3389/fmicb.2022.1057621