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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 -
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 -
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 -
Microorganisms Jun 2019is an ocular bacterial pathogen isolated in cases of keratitis, conjunctivitis, and endophthalmitis. Gram-negative brick-shaped diplobacilli from ocular specimens, and...
is an ocular bacterial pathogen isolated in cases of keratitis, conjunctivitis, and endophthalmitis. Gram-negative brick-shaped diplobacilli from ocular specimens, and slow growth in culture, are early indications of ocular infection; however, identifying to species can be complex and inconsistent. In this study, bacteria consistent with were identified to species using: (1) DNA sequencing coupled with vancomycin susceptibility, (2) MALDI-TOF mass spectrometry, and (3) the Biolog ID system. Study samples consisted of nine ATCC controls, 82 isolates from keratitis, 21 isolates from conjunctivitis, and 4 isolates from endophthalmitis. The ATCC controls were correctly identified. For keratitis, 66 (80.5%) were identified as , 7 (9.0%) as , 5 (6%) as , 2 (2.5%) as , 1 (1.0%) as , and 1 (1.0%) as . For conjunctivitis, 9 (43.0%) were identified as , 6 (29.0%) as , 3 (14.3%) as , 2 (9.5%) as (), and 1 (4.5%) as . From endophthalmitis, 3 of 4 of the isolates were . Overall, . and were identified in 70% (75 of 107) and 13% (14 of 107) of cases, respectively, totaling 83% (89 of 107). and are important bacterial pathogens of the eye as determined by DNA sequencing, MALDI-TOF MS, and Biolog. Although is a clinical pathogen, other species of appear to have a prominent role in eye infections.
PubMed: 31167433
DOI: 10.3390/microorganisms7060163 -
Revista Argentina de Microbiologia Feb 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.
PubMed: 38403533
DOI: 10.1016/j.ram.2023.12.003 -
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 -
Journal of Veterinary Internal Medicine 1998The economic impact of infectious bovine keratoconjunctivitis (IBK) warrants continued investigation of the mechanisms by which Moraxella bovis survives on and colonizes... (Review)
Review
The economic impact of infectious bovine keratoconjunctivitis (IBK) warrants continued investigation of the mechanisms by which Moraxella bovis survives on and colonizes the corneal surface. Virulent strains of M bovis produce hemolysin and exhibit different plasmid profiles than nonvirulent strains. Interactions among host, environment, vector, season, and concurrent infection influence the prevalence of IBK. Mycoplasma sp. or infectious bovine rhinotracheitis virus may enhance or hasten the disease process. The manifestations of IBK may range from mild conjunctivitis to severe ulceration, corneal perforation, and blindness. Treatment of IBK is dictated by economic considerations, intended animal use, and feasibility of administration. Antibiotic therapy is aimed at achieving drug concentrations in tears to meet or exceed the minimum inhibitory concentration for prolonged periods. At present, IBK is not a preventable disease. Affected animals must be separated from the herd and vector control vigorously instituted. Carrier animals must be identified and removed from the herd. Vaccination trials have been unsuccessful because of pili antigen cross-reactivity, variable strains, and uncontrolled environmental factors. Recent investigations have determined that M bovis may utilize host iron sources via iron-repressible outer membrane proteins and siderophores for growth. Elucidation of normal defense mechanisms of the bovine eye may lead to new strategies to enhance the immune response against M bovis.
Topics: Animals; Cattle; Cattle Diseases; Keratoconjunctivitis, Infectious
PubMed: 9686385
DOI: 10.1111/j.1939-1676.1998.tb02120.x -
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 -
American Journal of Veterinary Research Jul 2004To compare stability, antigenicity, and aggregation characteristics of Moraxella bovis cytolysins among isolates from geographically diverse areas. (Comparative Study)
Comparative Study
OBJECTIVES
To compare stability, antigenicity, and aggregation characteristics of Moraxella bovis cytolysins among isolates from geographically diverse areas.
STUDY POPULATION
8 isolates of M. bovis.
PROCEDURE
Filter-sterilized broth culture supernatants of M. bovis were concentrated, diafiltered, and chromatographed. The endotoxin and cytolysin activities in samples were measured. Chromatographed cytolysins of M. bovis were examined by immunoblotting. Hemolytic and leukotoxic activities were measured from samples collected at each step of purification and before and after storage. Hemolysis was measured directly by use of washed bovine erythrocyte targets. Leukotoxicity was measured by use of a 51Cr release assay.
RESULTS
Cytolysin was retained by a filter with 100-kd nominal molecular weight limit. Hemolytic activity, leukotoxic activity, and endotoxin were eluted together in void volume of a gel-filtration column (molecular mass exclusion limit = 4 X 10(7) d). Gel-column chromatographed diafiltered retentate had the greatest specific cytolytic activity and the highest endotoxin-to-protein ratio. Frozen diafiltered retentate(-80 degrees C, 4 months) was cytolytic after thawing. Immunoblots of gel-column chromatographed cytolysin contained 4 proteins with molecular masses between 90 and 68 kd. Fractions with high lytic activities also had additional protein bands with molecular masses of 98 and 63 kd. Immunoblots of gel-column chromatographed diafiltered retentate revealed proteins with molecular masses between 90 and 68 kd.
CONCLUSIONS AND CLINICAL RELEVANCE
Diafiltered M. bovis cytolysin is aggregated with endotoxin. Antigenicity and cytolytic activities in diafiltered retentate are conserved among M. bovis isolates. Diafiltration could be useful for bulk semipurification of M. bovis cytolysin. Cytolysin-enriched vaccines of M. bovis could be contaminated by endotoxin.
Topics: Analysis of Variance; Animals; Bacterial Toxins; Cattle; Chromates; Chromatography, Gel; Chromium Radioisotopes; Cytotoxins; Electrophoresis, Polyacrylamide Gel; Erythrocytes; Filtration; Hemolysis; Immune Sera; Immunoblotting; Leukocytes; Moraxella bovis; Sodium Compounds
PubMed: 15281658
DOI: 10.2460/ajvr.2004.65.977 -
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