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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 -
Brazilian Journal of Microbiology :... Sep 2021Infectious keratoconjunctivitis (IKC) is the most frequent ocular disease in livestock worldwide and is primarily caused by Moraxella bovis, M. ovis, and/or M. bovoculi....
Infectious keratoconjunctivitis (IKC) is the most frequent ocular disease in livestock worldwide and is primarily caused by Moraxella bovis, M. ovis, and/or M. bovoculi. The economic impact of IKC is mainly due to ocular damage, which leads to weight loss, management difficulties, pain and discomfort, and cost of treatments. In horses, limited information is available on the association of Moraxella spp. with keratoconjunctivitis. The present report describes two cases of equine keratoconjunctivitis caused by members of the genus Moraxella. Both animals presented with lacrimation, conjunctivitis, photophobia, mucoid or purulent secretions, blepharitis, and conjunctival hyperemia. The diagnosis of IKC was based on the epidemiological and clinical findings; the etiological agent was identified through bacteriological (culture and biochemistry assays) and molecular testing (PCR and nucleotide sequencing). Our study reports the isolation of Moraxella bovoculi (SBP 88/19) and a putative new species/mutant of Moraxella (SBP 39/19) recovered from ocular secretions in horses. Thus, we suggest the inclusion of Moraxella spp. infection in the differential diagnosis of conjunctivitis in horses in Southern Brazil.
Topics: Animals; Brazil; Horses; Keratoconjunctivitis, Infectious; Moraxella; Moraxellaceae Infections
PubMed: 33931826
DOI: 10.1007/s42770-021-00507-1 -
Frontiers in Cellular and Infection... 2021is the bacterium most often cultured from ocular lesions of cattle with infectious bovine keratoconjunctivitis, also known as bovine pinkeye. Some strains of contain...
is the bacterium most often cultured from ocular lesions of cattle with infectious bovine keratoconjunctivitis, also known as bovine pinkeye. Some strains of contain operons encoding for a repeats-in-toxin (RTX) toxin, which is a known virulence factor of multiple veterinary pathogens. We explored the utility of MALDI-TOF MS and biomarker detection models to classify the presence or absence of an RTX phenotype in . Ninety strains that had undergone whole genome sequencing were classified by the presence or absence of complete RTX operons and confirmed with a visual assessment of hemolysis on blood agar. Strains were grown on Tryptic Soy Agar (TSA) with 5% sheep blood, TSA with 5% bovine blood that was supplemented with 10% fetal bovine serum, 10 mmol/LCaCl, or both. The formulations were designed to determine the influence of growth media on toxin production or activity, as calcium ions are required for toxin secretion and activity. Mass spectra were obtained for strains grown on each agar formulation and biomarker models were developed using ClinProTools 3.0 software. The most accurate model was developed using spectra from strains grown on TSA with 5% bovine blood and supplemented with CaCl, which had a sensitivity and specificity of 93.3% and 73.3%, respectively, regarding RTX phenotype classification. The same biomarker model algorithm developed from strains grown on TSA with 5% sheep blood had a substantially lower sensitivity and specificity of 68.0% and 52.0%, respectively. Our results indicate that MALDI-TOF MS biomarker models can accurately classify strains of regarding the presence or absence of RTX toxin operons and that agar media modifications improve the accuracy of these models.
Topics: Agar; Animals; Biomarkers; Calcium Chloride; Cattle; Cattle Diseases; Keratoconjunctivitis, Infectious; Moraxella; Phenotype; Sheep; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 33796479
DOI: 10.3389/fcimb.2021.632647 -
Journal of Medical Microbiology Feb 2021is frequently isolated from the eyes of cattle with infectious bovine keratoconjunctivitis (IBK; pinkeye). As with which has been causally linked to IBK, expresses...
is frequently isolated from the eyes of cattle with infectious bovine keratoconjunctivitis (IBK; pinkeye). As with which has been causally linked to IBK, expresses an RTX (repeats in the structural toxin) cytotoxin that is related to cytotoxin. Pilin, another pathogenic factor in , is required for corneal attachment. Seven antigenically distinct pilin serogroups have been described in . Multiple different serogroups exist amongst type IV pilin encoded by , however, it is not known whether exhibits a similar degree of diversity in type IV pilin that it encodes. This study was done to characterize a structural pilin (PilA) encoded by isolated from cases of IBK to determine if diversity exists amongst PilA sequences. Ninety-four isolates of collected between 2002 and 2017 from 23 counties throughout California and from five counties in four other Western states were evaluated. DNA sequencing and determination of deduced amino acid sequences revealed ten (designated groups A through J) unique PilA sequences that were ~96.1-99.3 % identical. Pilin groups A and C matched previously reported putative PilA sequences from isolated from IBK-affected cattle in the USA (Virginia, Nebraska, and Kansas) and Asia (Kazakhstan). The ten pilin sequences identified were only ~74-76 % identical to deduced amino acid sequences of putative pilin proteins identified from the previously reported whole-genome sequences of derived from deep nasopharyngeal swabs of IBK-asymptomatic cattle. Compared to the diversity reported between structural pilin proteins amongst different serogroups of , PilA from geographically diverse isolates derived from IBK-affected cattle are more conserved.
Topics: Amino Acid Sequence; Animals; Cattle; Cattle Diseases; Fimbriae Proteins; Fimbriae, Bacterial; Genetic Variation; Genome, Bacterial; Keratoconjunctivitis; Moraxella; Moraxellaceae Infections
PubMed: 33404383
DOI: 10.1099/jmm.0.001293 -
Veterinary and Animal Science Jun 2020Infectious bovine keratoconjunctivitis (IBK) is a widespread, contagious ocular disease that affects cattle, especially dairy breeds. The disease is caused by...
Infectious bovine keratoconjunctivitis (IBK) is a widespread, contagious ocular disease that affects cattle, especially dairy breeds. The disease is caused by Gram-negative bacteria mainly and its treatment consists of parenteral or topic antibiotic therapy. The topic treatment approach is used more commonly in lactating cows, to avoid milk disposal. However, treatment failures are common, because the antibiotic is removed during lacrimation. This study aimed to evaluate the susceptibility of commercial cloxacillin and evaluate the efficacy of nanostructured cloxacillin in clinical cases of IBK by . The minimum inhibitory concentration (MIC) of nanoparticle cloxacillin nanocoated, the nanoparticle without the antibiotic and the commercial cloxacillin were determined with field samples of (5) and (5). The efficiency of nanoparticles was tested in three cows naturally infected that were treated with 1.0 mL (with 0.32 mg of nanostructured cloxacillin) for the ocular route. was isolated and identified by biochemical and molecular methods before the treatment. The animals were treated every 12 h for six days. The cure was considered by the absence of clinical symptoms and bacteria after treatment. The mucoadhesive nanoparticle-based formulation promoted clinical cure with a low number of doses of antibiotics, probably due to the maintenance of the MIC in the ocular mucosa for longer due to the mucoadhesive characteristics of the nanoparticle. The results indicate that the use of nanocoated cloxacillin is possible to control infectious bovine keratoconjunctivitis.
PubMed: 32734103
DOI: 10.1016/j.vas.2020.100089 -
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 -
Animals : An Open Access Journal From... Jan 2020Infectious bovine keratoconjunctivitis (IBK) caused by is commonly seen in the summer months spread by face flies. This trial investigated the difference in incidence...
Infectious bovine keratoconjunctivitis (IBK) caused by is commonly seen in the summer months spread by face flies. This trial investigated the difference in incidence of IBK cases from natural exposure between two groups of animals, one treated with Cypermethrin pour-on preparation (PON, n = 98) and one with Cypermethrin impregnated ear tags (TAG, n = 99). Daily Live Weight Gain (DLWG) difference was investigated between animals with cases and those without and between treatment groups. A randomised positive control study, enrolled 197 animals split into two treatment groups. Cases of IBK and DLWG were recorded over the grazing season (April-November 2018). Fifty-four cases of IBK were recorded. There was no association between the two treatment groups (p = 0.362) and case status. Breed and under 12 months old were significant factors for having a case; (OR 2.3, = 0.014 and OR 3.5, < 0.001 respectively). There was no difference in DLWG between animals that had a case and animals that had not (p = 0.739) or between the two treatment groups (p = 0.215). Based on our results, there is no significant difference between PON or TAG preparations in the prevention of IBK. Younger animals and white-faced breeds are significantly more likely to suffer with IBK.
PubMed: 31978947
DOI: 10.3390/ani10020184