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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 -
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 -
The Veterinary Clinics of North... Jul 2021Environmental factors that contribute to the pathogenesis of infectious bovine keratoconjunctivitis (IBK) include face flies, ultraviolet (UV) radiation, and mechanical... (Review)
Review
Environmental factors that contribute to the pathogenesis of infectious bovine keratoconjunctivitis (IBK) include face flies, ultraviolet (UV) radiation, and mechanical irritation from plant awns or dust. Limited research has shown face fly control to be associated with lower incidence of IBK. UV radiation is known to cause corneal irritation and damage in mammalian species. The increased formation of corneal dark cells has been observed following UV radiation in exposed calves. Moraxella bovis preferentially binds to corneal dark cells where it can be found in pits, which may be formed due to bacterial contact. Little is known about the efficacy of management of pasture plants on the prevention of IBK.
Topics: Animal Husbandry; Animals; Cattle; Cattle Diseases; Diptera; Eye Foreign Bodies; Keratoconjunctivitis, Infectious; Ultraviolet Rays
PubMed: 34049661
DOI: 10.1016/j.cvfa.2021.03.006 -
Carbohydrate Research Feb 2016Moraxella bovis is a Gram-negative gammaproteobacterium and is one of the causative agents of infectious bovine keratoconjunctivitis. The structure of...
Moraxella bovis is a Gram-negative gammaproteobacterium and is one of the causative agents of infectious bovine keratoconjunctivitis. The structure of lipooligosaccharide (LOS) from strain Epp63 was recently elucidated. In the present study a genetic locus of seven encoding genes with high similarity to glycosyltransferases has been identified. Mutation of these putative glycosyltransferase genes resulted in M. bovis mutant bacteria that expressed truncated LOS structures. The structures of the oligosaccharide (OS) expressed by the mutant strains were elucidated and demonstrated the role of the glycosyltransferase enzymes in the LOS biosynthesis of M. bovis. The glycosyltransferase genes designated lgt1, lgt3, and lgt6 are highly similar to the genes in the related bacterium M. catarrhalis. In addition, there are syntenic similarities with the corresponding LOS biosynthesis locus in M. catarrhalis and other members of Moraxellaceae.
Topics: Bacterial Proteins; Cloning, Molecular; Computer Simulation; Genetic Loci; Glycosyltransferases; Lipopolysaccharides; Moraxella bovis; Mutation; Sequence Homology, Nucleic Acid
PubMed: 26774874
DOI: 10.1016/j.carres.2015.12.003 -
BMC Microbiology Oct 2022Moraxella bovis and Moraxella bovoculi both associate with infectious bovine keratoconjunctivitis (IBK), an economically significant and painful ocular disease that...
BACKGROUND
Moraxella bovis and Moraxella bovoculi both associate with infectious bovine keratoconjunctivitis (IBK), an economically significant and painful ocular disease that affects cattle worldwide. There are two genotypes of M. bovoculi (genotypes 1 and 2) that differ in their gene content and potential virulence factors, although neither have been experimentally shown to cause IBK. M. bovis is a causative IBK agent, however, not all strains carry a complete assortment of known virulence factors. The goals of this study were to determine the population structure and depth of M. bovis genomic diversity, and to compare core and accessory genes and predicted outer membrane protein profiles both within and between M. bovis and M. bovoculi.
RESULTS
Phylogenetic trees and bioinformatic analyses of 36 M. bovis chromosomes sequenced in this study and additional available chromosomes of M. bovis and both genotype 1 and 2 M. bovoculi, showed there are two genotypes (1 and 2) of M. bovis. The two M. bovis genotypes share a core of 2015 genes, with 121 and 186 genes specific to genotype 1 and 2, respectively. The two genotypes differ by their chromosome size and prophage content, encoded protein variants of the virulence factor hemolysin, and by their affiliation with different plasmids. Eight plasmid types were identified in this study, with types 1 and 6 observed in 88 and 56% of genotype 2 strains, respectively, and absent from genotype 1 strains. Only type 1 plasmids contained one or two gene copies encoding filamentous haemagglutinin-like proteins potentially involved with adhesion. A core of 1403 genes was shared between the genotype 1 and 2 strains of both M. bovis and M. bovoculi, which encoded a total of nine predicted outer membrane proteins.
CONCLUSIONS
There are two genotypes of M. bovis that differ in both chromosome content and plasmid profiles and thus may not equally associate with IBK. Immunological reagents specifically targeting select genotypes of M. bovis, or all genotypes of M. bovis and M. bovoculi together could be designed from the outer membrane proteins identified in this study.
Topics: Cattle; Animals; Moraxella bovis; Keratoconjunctivitis, Infectious; Phylogeny; Hemolysin Proteins; Hemagglutinins; Cattle Diseases; Moraxellaceae Infections; Genotype; Whole Genome Sequencing; Virulence Factors
PubMed: 36271336
DOI: 10.1186/s12866-022-02670-3 -
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 -
Animal Microbiome Nov 2023Infectious bovine keratoconjunctivitis (IBK) is a common cause of morbidity in cattle, resulting in significant economic losses. This study aimed to characterize the...
BACKGROUND
Infectious bovine keratoconjunctivitis (IBK) is a common cause of morbidity in cattle, resulting in significant economic losses. This study aimed to characterize the bovine bacterial ocular surface microbiome (OSM) through conjunctival swab samples from Normal eyes and eyes with naturally acquired, active IBK across populations of cattle using a three-part approach, including bacterial culture, relative abundance (RA, 16 S rRNA gene sequencing), and semi-quantitative random forest modeling (real-time polymerase chain reaction (RT-PCR)).
RESULTS
Conjunctival swab samples were obtained from eyes individually classified as Normal (n = 376) or IBK (n = 228) based on clinical signs. Cattle unaffected by IBK and the unaffected eye in cattle with contralateral IBK were used to obtain Normal eye samples. Moraxella bovis was cultured from similar proportions of IBK (7/228, 3.07%) and Normal eyes (1/159, 0.63%) (p = 0.1481). Moraxella bovoculi was cultured more frequently (p < 0.0001) in IBK (59/228, 25.88%) than Normal (7/159, 4.40%) eyes. RA (via 16 S rRNA gene sequencing) of Actinobacteriota was significantly higher in Normal eyes (p = 0.0045). Corynebacterium variabile and Corynebacterium stationis (Actinobacteriota) were detected at significantly higher RA (p = 0.0008, p = 0.0025 respectively) in Normal eyes. Rothia nasimurium (Actinobacteriota) was detected at significantly higher RA in IBK eyes (p < 0.0001). Alpha-diversity index was not significantly different between IBK and Normal eyes (p > 0.05). Alpha-diversity indices for geographic location (p < 0.001), age (p < 0.0001), sex (p < 0.05) and breed (p < 0.01) and beta-diversity indices for geographic location (p < 0.001), disease status (p < 0.01), age (p < 0.001), sex (p < 0.001) and breed (p < 0.001) were significantly different between groups. Modeling of RT-PCR values reliably categorized the microbiome of IBK and Normal eyes; primers for Moraxella bovoculi, Moraxella bovis, and Staphylococcus spp. were consistently the most significant canonical variables in these models.
CONCLUSIONS
The results provide further evidence that multiple elements of the bovine bacterial OSM are altered in the context of IBK, indicating the involvement of a variety of bacteria in addition to Moraxella bovis, including Moraxella bovoculi and R. nasimurium, among others. Actinobacteriota RA is altered in IBK, providing possible opportunities for novel therapeutic interventions. While RT-PCR modeling provided limited further support for the involvement of Moraxella bovis in IBK, this was not overtly reflected in culture or RA results. Results also highlight the influence of geographic location and breed type (dairy or beef) on the bovine bacterial OSM. RT-PCR modeling reliably categorized samples as IBK or Normal.
PubMed: 37996960
DOI: 10.1186/s42523-023-00282-4 -
Journal of the Association of Medical... Jun 2022We report a rare case of bacteremia and polyarticular septic arthritis in a 37-year-old pregnant woman with HIV who injects drugs. Two sets of blood cultures obtained 5...
CASE PRESENTATION
We report a rare case of bacteremia and polyarticular septic arthritis in a 37-year-old pregnant woman with HIV who injects drugs. Two sets of blood cultures obtained 5 hours apart were positive for gram-negative bacilli, and purulent fluid was present intra-operatively from both her left knee and her right third MCP joints.
DIAGNOSIS
Organism identification using ligation sequencing confirmed both her blood culture and synovial tissue isolates as . Her infection was initially treated with third-generation cephalosporins and later changed to moxifloxacin because of a drug reaction; although she defervesced clinically with improvement in her C-reactive protein levels, she died most likely as a result of a non-traumatic fat embolism after an elective cesarean delivery.
DISCUSSION
In contrast to , other species are rarely associated with disease in human hosts. is classically associated with infectious bovine keratoconjunctivitis in cattle; interestingly, our patient denied significant animal exposure. To the authors' knowledge, this is the first case describing infection secondary to in an adult host.
PubMed: 36337353
DOI: 10.3138/jammi-2021-0027 -
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 -
Journal of Veterinary Diagnostic... Sep 2018Infectious bovine keratoconjunctivitis (IBK) is an economically significant disease caused by Moraxella bovis. Moraxella bovoculi, although not reported to cause IBK,...
Infectious bovine keratoconjunctivitis (IBK) is an economically significant disease caused by Moraxella bovis. Moraxella bovoculi, although not reported to cause IBK, has been isolated from the eyes of cattle diagnosed with IBK. Identification of M. bovis and M. bovoculi can be performed using biochemical or DNA-based approaches, both of which may be time consuming and inconsistent between laboratories. We conducted a comparative evaluation of M. bovoculi and M. bovis identification using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) with a database provided by Bruker Daltonics (termed the BDAL database), the BDAL database supplemented with spectra generated in our study (termed the UNLVDC database), and with PCR-restriction-fragment length polymorphism (PCR-RFLP) typing. M. bovoculi ( n = 250) and M. bovis ( n = 18) isolates from cattle with or without IBK were used. MALDI-TOF MS using the UNLVDC database correctly identified 250 of 250 (100%) of M. bovoculi and 17 of 18 (94%) of M. bovis isolates. With the BDAL database, MALDI-TOF MS correctly identified 249 of 250 (99%) of M. bovoculi and 7 of 18 (39%) of M. bovis isolates. In comparison, the PCR-RFLP test correctly identified 210 of 250 (84%) of M. bovoculi and 12 of 18 (66%) of M. bovis isolates. Thus, MALDI-TOF MS with the UNLVDC database was the most effective identification methodology for M. bovis and M. bovoculi isolates from cattle.
Topics: Animals; Cattle; Cattle Diseases; Databases, Factual; Keratoconjunctivitis, Infectious; Mass Spectrometry; Moraxella; Moraxella bovis; Moraxellaceae Infections; Polymerase Chain Reaction; Polymorphism, Restriction Fragment Length; Sensitivity and Specificity; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 30027824
DOI: 10.1177/1040638718789725