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PubMed1991

Moraxella (Branhamella) catarrhalis.

Moraxella (Branhamella) catarrhalis is now a well-recognized pathogen in lower respiratory tract infections, particularly in the setting of chronic lung disease. The ability to produce beta-lactamase, which now characterizes most clinical strains, appears to be a recently acquired trait. The most common clinical syndrome caused by this organism is exacerbation of chronic bronchitis; this syndrome has been well described in Europe, Japan, and the United States, particularly from centers with a large elderly population with chronic lung disease. The syndrome of pneumonia is less common, and suppurative complications and bacteremia are rare.

Anti-Bacterial Agents↗
PubMed1990

Plasmid content of piliated and nonpiliated forms of Moraxella bovis.

Plasmid profiles were compared between nonpiliated and piliated forms of Moraxella bovis isolates. The piliated form of M bovis isolate IBH64 contained 1 fewer plasmid than did the nonpiliated form. Piliated and nonpiliated cells of IBH64 contained plasmids having molecular size of 45, 32.8, 4.9, and 4.6 kilobases (kb). Single- and double-restriction endonuclease digestion by Ava I and Nde I indicated that the size of the additional plasmid carried by the nonpiliated form of IBH64 was approximately 43.6 kb. The M bovis isolates, Newport and GRS, contained the same number of plasmids in either their piliated or nonpiliated form.

DNA Restriction Enzymes↗
PubMed1990

Moraxella (Branhamella) catarrhalis bacteremia. A case report and literature review.

Moraxella catarrhalis is increasingly recognized as a cause of pulmonary and upper airway disease, but bacteremia remains unusual. We treated a 71-year-old man who died of rapidly progressive bacteremic M catarrhalis bronchopneumonia. This case, and a review of the 27 previously reported M catarrhalis bacteremias in the literature, demonstrated that M catarrhalis can be a virulent organism capable of causing serious infection and death in both immunocompetent and compromised hosts.

Aged↗
PubMed1985

Immunogenicity of Moraxella bovis hemolysin.

Anti-Moraxella bovis hemolysin activity was observed in 35 cattle exposed to field infections of infectious bovine keratoconjunctivitis (IBK). All cattle in infected herds seroconverted with respect to antihemolysin whether or not clinical IBK was noted. Cattle previously exposed to IBK possessed higher antihemolysin titers than did younger, nonexposed cattle. Antihemolysin activity was noted in bovine sera up to 7 years after exposure to IBK. Sera from experimentally infected calves were found to possess antihemolytic activity against all 33 strains of M bovis tested. Antihemolytic activity could be demonstrated in random-bred mice inoculated with whole doxycycline-treated M bovis, frozen or lyophilized whole M bovis, and membrane fractions treated with sodium lauryl sarcosinate, Triton X 100, and Triton X 100 + EDTA, but not with formalin-treated whole M bovis.

Animals↗
PubMed1989

Infectious bovine keratoconjunctivitis epizootic associated with area-wide emergence of a new Moraxella bovis pilus type.

Pilus-mediated adherence is a virulence attribute of Moraxella bovis. Several pilus types have been shown to exist among strains of this bacterium, but correlation between pilus type and specific field cases of the disease has not been done. During the summer of 1987, an epizootic of infectious bovine keratoconjunctivitis was reported in 7 Iowa counties. Eight isolates of M bovis were secured from 12 episodes studied. All 8 of the isolates were nearly homogeneous in biochemical properties and had the same plasmid biotype. Pilus typing performed by immunofluorescence and immunogold electron microscopy identified a single new pilus type among 5 of the 8 isolates. This pilus type was identified in field cases that developed within a narrow time frame and over large distances. The implication of these findings is that infectious bovine keratoconjunctivitis epizootics may be associated with emergence of a novel pilus type, and that rapid dissemination over wide distances can occur, presumably by transportation of carrier cattle.

Animals↗
PubMed1989

Botryomycosis caused by Moraxella nonliquefaciens.

Botryomycosis is a bacterial infection characterized by the presence of grains of organisms in the tissue. Although Staphylococcus aureus is the most common causative agent, other bacteria have been reported to cause botryomycosis. Several factors have been hypothesized to be important in the pathogenesis of botryomycosis, including foreign bodies, quantity and virulence of organisms, and host immunity. The resulting infection tends to be resistant to antibiotic therapy. We report a case of botryomycosis of the hand caused by Moraxella nonliquefaciens, an organism of low virulence not previously associated with botryomycosis, and discuss the factors that may have led to this infection. This infection was successfully treated by excision and grafting.

Adult↗
PubMed1989

Characterization of the plasmids of Moraxella bovis.

Restriction endonuclease digestions were performed on plasmids purified from Moraxella bovis isolates GRS, Newport, and IBH64. It was determined from single and double digestions of plasmid DNA that GRS and Newport isolates carried 3 large plasmids having molecular sizes of 43.8, 41.3, and 32.8 kilobases (kb). Digestion of the 3 large plasmids and restriction endonucleases Hae III, HindIII, Nde I, and Ava I strongly indicated that these isolates shared structurally identical large plasmids. Timed single digestions with Ava I revealed that the IBH64 isolate carried 2 large plasmids having molecular sizes of 45 and 32.8 kb. The 32.8-kb plasmid was the only large plasmid that appeared to be shared by all 3 M bovis isolates. Two isolates, Newport and IBH64, carried small plasmids in addition to the large plasmids. Restriction maps were constructed for the 43.8-, 41.3-, and 32.8-kb plasmids.

Animals↗
PubMed1988

Light and electron microscopic changes in corneas of healthy and immunomodulated calves infected with Moraxella bovis.

Thirty-nine Holstein calves (50 to 100 kg and 2 to 3 months old) were randomly assigned to 4 groups. Calves in group I (n = 12) were inoculated with Moraxella bovis and were euthanatized 24 hours (6 calves) or 8 days after inoculation (6 calves). Group-II calves (n = 12) were treated with hydroxyurea for 6 days, and then 6 of these calves were inoculated with M bovis. The daily hydroxyurea treatments continued for 14 days, and then all calves in group II were euthanatized. Group-III calves (n = 9) were administered dexamethasone parenterally, beginning 24 hours before inoculation with M bovis, and then daily thereafter, until they were euthanatized at either 24 hours (n = 5) or 8 days (n = 4). Group-IV calves (n = 6) were inoculated with M bovis, and euthanatized 12 hours later. Tears were collected from all calves that had been inoculated more than 24 hours earlier. The concentration of myeloperoxidase and collagenase was determined for each sample. After the calves were euthanatized, the corneas were dissected free, fixed, and examined by use of scanning or transmission electron microscopy, or light microscopy. Microscopic corneal erosions were detected 12 hours after inoculation. These lesions were not accompanied by inflammatory cell infiltration and were detected by use of scanning electron microscopy. Inflammatory cells were first observed in the corneal lesions in specimens collected 24 hours after inoculation. Bacteria that resembled M bovis morphologically were seen in several locations in these lesions. By 8 days, corneas of the group-I calves had the least number of intracorneal bacteria, compared with the corneas from other groups. The number of calves that developed corneal ulcers by 8 days was similar in all groups. The corneal ulcers of the hydroxyurea-treated calves were shallower, but appeared larger in surface area than those of the controls. By 8 days after inoculation, the corneal ulcers of the dexamethasone-treated calves had less corneal neovascularization and opacification than did the controls. Corneal perforations developed in 2 eyes of the dexamethasone-treated calves, but did not develop in any eyes of the controls. Microscopically, a larger number of M bovis were observed in corneas of dexamethasone-treated calves than in corneas of calves from other groups. Collagenase was not detected in any tear samples. The concentration of myeloperoxidase in tear samples were significantly (P less than 0.05) higher in the prehydroxyurea-treatment samples than in the posttreatment samples from corresponding calves.

Animals↗
PubMed1985

Infectious bovine keratoconjunctivitis: subconjunctival administration of a Moraxella bovis pilus preparation enhances immunogenicity.

To compare the immune response elicited by 3 routes of vaccination, 36 calves were randomly allotted to 4 groups of 9 calves each. Group I was vaccinated subconjunctivally only. Group II was vaccinated concomitantly, both subconjunctivally and in the dewlap. Group III was vaccinated in the dewlap only. Group IV was not vaccinated and served as a virulence control for the Moraxella bovis culture. Calves in groups I, II, and III were given 2 inoculations with 14 days between inoculations. Twenty-one days after the last inoculation, the ventral conjunctival sac of all calves was instilled with cells of a virulent M bovis strain. After challenge exposure, all vaccinated calves (groups I, II, and III) had evidence of enhanced resistance, compared with the nonvaccinated calves. The highest to lowest gradients of immune responsiveness were: Group I greater than or equal to group II greater than group III greater than group IV. When immune criteria, such as the percentage of diseased eyes, the mean duration of infection, the severity of corneal lesions, and the serologic response were compared, groups I and II were significantly (P less than 0.05) more resistant to challenge exposure than were groups III and IV. Group III was significantly (P less than 0.05) different from group IV in severity of lesions and in serologic response. Also, the mean duration of infection was shorter, and the percentage of diseased eyes was less in group III than in group IV (P greater than 0.10). Group I was more resistant than was group II (P less than 0.10).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Adherence of Moraxella bovis to cell cultures of bovine origin.

The adherence of five strains of Moraxella bovis to cell cultures was investigated. M bovis adhered to cultures of bovine corneal epithelial and Madin-Darby bovine kidney cells but not to cell types of non-bovine origin. Both piliated and unpiliated strains adhered but piliated strains adhered to a greater extent than unpiliated strains. Antiserum against pili of one strain inhibited adherence of piliated strains but caused only slight inhibition of adherence to the unpiliated strains. Treatment of bacteria with magnesium chloride caused detachment of pili from the bacterial cell and markedly inhibited adherence of piliated strains but caused only slight inhibition of adherence by the unpiliated strains. The results suggested that adhesion of piliated strains to cell cultures was mediated via pili but that adhesins other than pili may be involved in the attachment of unpiliated strains of M bovis to cells.

Adhesiveness↗
PubMed1986

Pathogenicity and immunogenicity of piliated and nonpiliated phases of Moraxella bovis in calves.

Pathogenicity evaluations of Moraxella bovis strain EPP 63 grown in the piliated and nonpiliated phase indicated that the organism grown in the piliated phase induced clinical keratoconjunctivitis, whereas the organism grown in the nonpiliated phase did not induce disease under identical challenge conditions. Calves inoculated with culture grown in the piliated phase developed significantly (P less than 0.01) higher lesion scores than did calves inoculated with culture grown in the nonpiliated phase. Vaccination/challenge exposure evaluations indicated that calves immunized with vaccine prepared from piliated culture had significantly lower lesion scores than did control calves (P less than 0.001) or calves immunized with vaccine prepared from nonpiliated culture (P less than 0.05). Similarly, calves immunized with piliated vaccine developed a significantly higher antibody titer against purified pili. Nonvaccinated controls and calves immunized with nonpiliated vaccine did not develop a significant increase in antibody titer. The results indicate that M bovis pili constitute an important factor in the pathogenicity of keratoconjunctivitis and may be used as a vaccine in the control of keratoconjunctivitis in cattle.

Animals↗
PubMed1986

Characterisation and quantitation of pilus antigens of Moraxella bovis by ELISA.

Hyperimmune serums raised in rabbits to purified pili from 9 Australian and 2 American strains of Moraxella bovis from infectious bovine keratoconjunctivitis (IBK) affected herds were used to study the degree of binding between combinations of antigen and antiserum in a conventional enzyme linked immunosorbent assay (ELISA). With the aid of appropriate absorption tests major antigenic differences among pili were found permitting 6 distinct serogroups to be recognised. Further, production of specific antiserums to representative strains of each serogroup in goats facilitated the development of a double antibody sandwich ELISA which could be used to quantitate pilus expression of a given strain of M. bovis, or to differentiate pilus serogroups of 22 strains of M. bovis obtained from a total of 12 Australian herds. Most isolates were found to belong to serogroups designated IV and V. One strain from the United States of America showed total homology with Australian serogroup IV while the other showed some cross-reactivity with serogroups V and VI.

Animals↗
PubMed1989

Cytopathic effects of Moraxella bovis on cultured bovine neutrophils and corneal epithelial cells.

The effects of Moraxella bovis on the morphologic features of purified bovine neutrophils and bovine corneal epithelial cells were examined, using transmission and scanning electron microscopy and light microscopy. Within 2 minutes after incubation of bovine neutrophils with living M bovis, electron microscopic cellular changes included vacuolation, swelling, and loss of microplicae. Most of the neutrophils were lysed by 10 minutes of incubation. Human neutrophils phagocytosed the M bovis and remained intact, even after 30 minutes of incubation with the bacteria. Living M bovis killed bovine corneal epithelial cells in vitro. Sterile filtrates prepared from 6-hour shaker cultures of M bovis also killed bovine corneal epithelial cells, but the cytotoxic activity was less than that produced by the living bacteria. Cellular changes were first observed in specimens collected 1 hour after corneal cell monolayers were inoculated with sterile culture filtrates. The changes in these cells included pit-like lesions on the cellular surface, cellular separation, and vacuolation.

Animals↗
PubMed1989

Effects of Moraxella bovis and culture filtrates on 51Cr-labeled bovine neutrophils.

The cytotoxicity of Moraxella bovis whole cells and culture filtrates was studied, using 51Cr-labeled bovine and human blood neutrophils. The cytotoxicity of living M bovis was directly related to the concentration of bacteria in the neutrophil cultures, and was maximal at an approximate neutrophil to bacteria ratio of 1:10. Cytotoxicity was maximal by 30 minutes after living bacteria were added to the suspension of the 51Cr-labeled neutrophils. Expression of the cytotoxicity was dependent on the presence of Ca2+ in the media, and was independent of the presence of Mg2+. Cytotoxic activity was eliminated by inactivating M bovis in buffers containing formalin or sodium azide. Hemolytic and nonhemolytic isolates of M bovis were examined for cytotoxic activity. All 7 of the hemolytic isolates were cytotoxic for bovine neutrophils, but all 4 of the nonhemolytic isolates were devoid of cytotoxic activity. None of the 11 isolates were cytotoxic for human neutrophils. Sterile filtrates from 6-hour shaker cultures of a hemolytic M bovis isolate were cytotoxic for bovine neutrophils. Cytotoxicity of the filtrate was eliminated by heating, incubation with trypsin, or addition of EDTA to the media. Bacterial homogenates or sterile filtrates prepared from statistically incubated cultures of M bovis were not toxic for bovine neutrophils.

Animals↗
PubMed1988

[Species-forming involution of pathogenic bacteria as a biological pattern (exemplified by bacteria of the genus Moraxella)].

The author advances a hypothesis stating that a species disappearing as a result of new conditions evolving in a colonized animal or human body, unfavorable for the existence of this species, does not become extinct, but reverts into newly developing species due to the loss of its properties and acquiring new properties corresponding to new conditions. Thus the genus is preserved through the loss of species characteristics by individual organisms. The advanced hypothesis is substantiated by the analysis of the relevant processes observed in cases of infectious keratoconjunctivitis in humans and cattle, caused by bacteria of the genus Moraxella. The data indicating the possibility of such reversion in the genera Neisseria and Bordetella are presented.

Animals↗
PubMed1978

Detection of Moraxella bovis antibodies in the SIgA, IgG, and IgM classes of immunoglobulin in bovine lacrimal secretions by an indirect fluorescent antibody test.

The relationship between clinical infectious bovine keratoconjunctivitis (IBK) and Moraxella bovis antibodies was evaluated in a herd of calves during one summer. The detection and the distribution of antibody response in lacrimal secretions of beef calves to natural exposure of M bovis were determined by an indirect fluorescent antibody test. Three classes of immunoglobulins--secretory IgA, IgM, and IgG--were monitored in lacrimal secretions over a 5-month period when IBK was enzootic in the herd. The 3 classes of antibody to M bovis were detected in all but 2 calves at the start of the monitoring, and the highest and most persistent M bovis antibody titers were in the IgG immunoglobulin class, and less so in IgM and secretory IgA classes. The specific antibodies present in the lacrimal secretions did not prevent the development of clinical IBK in the calves.

Animals↗
PubMed1986

Use of subcutaneously implanted chambers in calves for in vivo study of isolates of Moraxella bovis.

Selected cultures of Moraxella bovis were studied in calves, using chambers fabricated from a semipermeable membrane supported and protected by perforated plastic golf balls. Plain balls, semipermeable membrane-covered balls, and balls that contained bags fabricated from semipermeable membranes were surgically implanted subcutaneously in calves at a site approximately 25 cm ventral to the paralumbar fossa and cranial to the prefemoral lymph node. After calves recovered from surgery, chambers were inoculated with different cultures of M bovis. Cultural examination of samples taken from inoculated chambers indicated that M bovis cultures were maintained within the chambers for variable times, depending on the characteristics of the culture inoculated. A smooth (piliated) culture dissociated into a rough (nonpiliated) culture after 4 weeks of incubation within a chamber but none of the rough cultures became smooth. The technique offers a method to study the in vivo variations in a series of cultures or strains of microorganisms under the influence of the same host factors. The selective permeability of the chamber may be controlled by using membranes of different porosities to control the flow of entering or exiting dialysate.

Animals↗
PubMed1986

Scanning electron microscopy of bovine corneas irradiated with sun lamps and challenge exposed with Moraxella bovis.

Effects of UV radiation and irradiation followed by challenge exposure with Moraxella bovis on the corneal epithelium were studied in 6 calves by scanning electron microscopy. After UV irradiation, the number of dark cells comprising the surface epithelium increased. Many epithelial cells were in various states of degeneration and were characterized initially by large round nuclei, whereas sloughing and peeling were characteristic of the last degenerative stage. All M bovis-infected irradiated eyes had large numbers of degenerating cells, deep epithelial defects, fibrin strands, surface inflammatory cells, and debris. A few M bovis organisms were randomly attached to the cornea before visible ulceration. There were many inflammatory cells between the ulcerated corneal epithelium and adjacent nonulcerated epithelium. Epithelial cells at the margin of the ulcer appeared swollen. Light, dark, and intermediate epithelial cell types could not be distinguished peripheral to the ulcer.

Animals↗