Moraxella Ovis Research Articles

Identification and characterization of complete RTX operons in Moraxella bovoculi and Moraxella ovis

To determine if Moraxella bovoculi ( M. bovoculi), a recently characterized coccoid Moraxella that was isolated from the eyes of calves affected with infectious bovine keratoconjunctivitis (IBK), and Moraxella ovis ( M. ovis), originally isolated from sheep with conjunctivitis, possessed genes encoding RTX proteins, genomic DNA was amplified with oligonucleotide primers targeting RTX operon genes of Moraxella bovis ( M. bovis). Complete classical RTX operons composed of RTXCABD genes closely linked to a putative secretion accessory protein encoding gene ( tolC) were identified in M. bovoculi and M. ovis and were designated mbvCABDtolC and movCABDtolC, respectively. These genes were closely related to M. bovis mbxCABDtolC. Polyclonal rabbit antiserum against the carboxy terminus of M. bovoculi MbvA neutralized hemolytic activity of both M. bovoculi and M. ovis; this antiserum did not neutralize the hemolytic activity of M. bovis. M. bovoculi and M. ovis possess genes that encode proteins related to pathogenic factors of M. bovis.

Moraxella bovoculi sp. nov., isolated from calves with infectious bovine keratoconjunctivitis

Eighteen isolates of a Gram-negative coccus (strain 237(T)) were cultured from the eyes of dairy and beef calves affected with infectious bovine keratoconjunctivitis (IBK; 'pinkeye') in northern California, USA, during summer 2002. These isolates had near full-length (1397 bp) 16S rRNA gene sequences that clustered into three groups with 99.9 % sequence similarity. On the basis of 16S rRNA gene sequence, the isolates were most closely associated with Moraxella bovis and Moraxella ovis in clade I of the classical moraxellae. Biochemically, the novel isolates could be distinguished from the other members of the genus Moraxella isolated from animals on the basis of phenylalanine deaminase activity. The results of partial sequence analysis of six housekeeping genes, the 16S-23S rRNA gene interspacer region and partial 23S rRNA gene provide strong support for the inclusion of these isolates in a novel taxon, for which the name Moraxella bovoculi sp. nov. is proposed. The type strain is strain 237(T) (=ATCC BAA-1259(T)=CCUG 52049(T)).

Recovery of Moraxella ovis from the bovine respiratory tract and differentiation of Moraxella species by tDNA-intergenic spacer PCR

The purpose of the present study was to identify Moraxella ( M.)—like organisms recovered from calves suffering from respiratory disease down to species level by means of tDNA-intergenic spacer length polymorphism analysis (tDNA-PCR), and to perform antimicrobial susceptibility testing of these isolates using an agar dilution technique. A total of 16 isolates originating from 12 unrelated occasions were identified as Moraxella ovis, and tDNA fingerprinting showed clear delineation from other Moraxella species. The minimal inhibitory concentrations (in μg/mL) for 90% of the investigated isolates were ≤0.03 for ampicillin; 0.25 for ceftiofur; 0.5 for oxytetracycline; 8 for gentamicin; 64 for spectinomycin; 0.5/9.5 for the combination trimethoprim-sulfonamides; 4 for erythromycin; 8 for tilmicosin; 1 for florfenicol and 0.125 for enrofloxacin.

Effect of the natural serum (non-immunized) on the bacteria isolated from pneumonic lung in sheep

Normal serum bactericidal activity study were carried out against nine bacterial species (Mannheimia haemolytica, Staphelococcus aureus, Arcanobacterium pyogenes, Streptococcus pyogenes, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Bacillus subtilis, Moraxella ovis) isolated from pneumonial lungs in sheep by the use of a normal non immunized serum collected from normally healthy sheep, cattle, horses. All species of bacteria were resistant for serum effect except B. subtilis and Pseudo. aeruginosa which were sensitive for all types of serum, while Moraxella ovis was sensitive for horse serum only, but Pseudomonas aeruginosa and Bacillus subtilis were resistant to complement free serum.

Bacteriological Investigation of Infectious Keratoconjunctivitis in Norwegian Sheep

Contagious keratoconjunctivitis is a rather common disease in Norwegian sheep. Since the knowledge of its aetiology is limited, the present study was performed to determine the microorganisms involved. Local veterinarians throughout the country collected conjunctival swabs from both sick (n = 43) and healthy (n = 42) sheep on 15 farms with outbreaks of ovine keratoconjunctivitis, and further from healthy sheep (n = 50) on 17 farms not showing any signs of conjunctival disease. All samples were cultivated for bacteria and mycoplasma.Listeria monocytogenes was isolated from 3 cases (1%) in one single herd. Staphylococcus aureus (5%), Corynebacterium spp. (2%) and Escherichia coli (4%) were isolated only in herds with keratoconjunctivitis, but from both sick and healthy animals. Moraxella (Branhamella) ovis was isolated from 28% of sampled animals in affected herds and from 10% of sampled animals in healthy herds. The corresponding numbers for Moraxella spp. were 9%/12%, for Pseudomonas spp. 7%/8%, for Staphylococcus spp. 22%/22%, for Bacillus spp. 12%/14%, for Micrococcus spp. 6%/2% and for Streptococcus/Enterococcus spp. 2%/2%. Mycoplasma conjunctivae was isolated from 16 animals with keratoconjunctivitis (37%) and from 3 animals without clinical signs (7%) in farms with keratoconjunctivitis. In farms without clinical signs of keratoconjunctivitis, M. conjunctivae was isolated in 4 animals (8%).To our knowledge, this is the first time M. conjunctivae has been isolated in Norway. Other predisposing agents found were Moraxella (Branhamella) ovis and Listeria monocytogenes. The etiological importance of different microorganisms in ovine keratoconjunctivitis seems to vary; some are probably only present as secondary invaders. Other possible causes of ovine keratoconjunctivitis in Norway, such as Chlamydia psittaci, remain to be investigated.

Biodegradation of an s-triazine herbicide, simazine

Two types of simazine-degrading microorganisms were isolated from soil samples where the herbicide had been spread with the enrichment culture using simazine as the sole carbon and nitrogen source.A fungal strain, DS6F, identified as Penicillium steckii, is the first simazine-degrading fungus ever reported.Simazine was gradually degraded by P. steckii DS6F in the mineral medium containing simazine (initial concentration: 50 mg/l) and 25 mg/l of yeast extract. The rate of simazine degradation was improved when assimilable carbon sources were added into the medium, and the reduction rate of 53% was obtained after 5 days of cultivation at 30°C when glucose was added into the basal medium.The bacterial strain, N5C, identified as Moraxella (Branhamella) ovis, was newly isolated and proven to degrade simazine more effectively than strain, DS6F, and 200 mg/l of simazine disappeared almost completely within 5 days at 35°C.M. (Branhamella) ovis could also degrade another s-triazine herbicide, atrazine, at the similar reduction rate as simazine.

Bacteria and nematodes in the conjunctiva of mule deer from Wyoming and Utah.

Swabs of conjunctiva were collected from 44 live and 226 hunter-harvested mule deer (Odocoileus hemionus) from Wyoming and Utah (USA). We identified 29 gram negative and 22 gram positive bacterial taxonomic categories, but many isolates from hunter-harvested animals were environmental contaminants. Staphylococcus spp. and Micrococcus spp. were the most common gram positive bacteria isolated, and Enterobacter spp., Escherichia coli, and Pseudomonas spp. were common gram negative bacteria isolated. Thelazia californiensis were found in 15% of hunter-harvested deer in Utah in 1994 and in 8% in 1995. Nematodes were found in 40% of live deer in 1995 and 66% in 1996. Three live animals showed clinical signs of infectious keratoconjunctivitis (IKC) in 1996, but pathogenic bacteria were not isolated from these individuals. Hemolytic, non-piliated Moraxella ovis was isolated from two clinically normal live deer in 1996 and isolates were similar to those cultured from IKC cases from Wyoming and Utah.

Association of Moraxella ovis with keratoconjunctivitis in mule deer and moose in Wyoming.

Six cases of infectious keratoconjunctivitis (IKC) in mule deer (Odocoileus hemionus) and moose (Alces alces) in Wyoming (USA) were investigated during fall and winter of 1995 and 1996. Excessive lacrimation, mucopurulent conjunctivitis, keratitis, and corneal opacity were observed in mule deer. Moose had severe mucopurulent conjunctivitis, keratitis, and corneal ulceration. Hemolytic, non-piliated Moraxella ovis was isolated from two mule deer and two moose. We attempted to reproduce IKC in three mule deer fawns using an isolate of M. ovis from a clinically affected mule deer. These fawns did not develop clinical signs of infection and the bacterium was not reisolated from inoculated deer. Inoculated deer may not have developed clinical signs because deer were not exposed to ultraviolet light or mechanical insult before inoculation. In addition, the isolate used for inoculation may have lost virulence factors through passage, or M. ovis may not have been the primary pathogen responsible for clinical disease in the natural cases of IKC we investigated. The etiology of IKC in free-ranging wild ruminants remains poorly understood.

Taxonomy of Moraxellaceae fam. nov., a New Bacterial Family To Accommodate the Genera Moraxella, Acinetobacter, and Psychrobacter and Related Organisms

DNA-rRNA hybridization results showed that members of the genus Moraxella, members of the genus Psychrobacter and their relatives, members of the genus Acinetobacter, the false neisseriae, and two misnamed Alysiella strains constitute a separate genotypic cluster. A new family, Moraxellaceae, is proposed to accommodate these organisms. The genus Moraxella is the type genus. Within the Moraxellaceae two main groups can be distinguished. One group includes the Acinetobacter species. The other group can be subdivided in four subgroups consisting of (i) the authentic moraxellae (Moraxella lacunata, Moraxella nonliquefaciens, Moraxella bovis, Moraxella catarrhalis, Moraxella caviae, Moraxella ovis, Moraxella cuniculi, and two misnamed Alysiella strains), (ii) the generically misnamed taxon Moraxella osloensis, (iii) the generically misnamed taxon Moraxella atlantae, and (iv) the generically misnamed taxon Moraxella phenylpyruvica, Psychrobacter immobilis, and allied organisms. The Moraxellaceae cluster belongs to the class Proteobacteria and is a member of superfamily II, which includes the authentic pseudomonads and related organisms. It is not related to the family Neisseriaceae.

Ovine keratoconjunctivitis experimentally induced by instillation of Mycoplasma conjunctivae.

Five sheep, free from Mycoplasma conjunctivae and ocular Chlamydia infection, were experimentally inoculated with M. conjunctivae and five more sheep were exposed to the infection by contact. Keratoconjunctivitis developed in all ten sheep. As in natural outbreaks of infectious keratoconjunctivitis (IKC), clinical signs were generally moderate and transient, and recurred in some sheep. M. conjunctivae was detected throughout the 53-day observation period. Clinical diagnosis was confirmed by histopathologic examination of three sheep. Moraxella ovis, found in six of the ten sheep before the start of the experiment, appeared to play no etiologic role in the development of IKC.

The occurrence of Mycoplasma conjunctivae in The Netherlands and its association with infectious keratoconjunctivitis in sheep and goats.

The occurrence of Mycoplasma conjunctivae in the Netherlands is reported for the first time. M. conjunctivae was detected in all five sheep flocks examined with clinical signs of infectious keratoconjunctivitis (IKC) and in none of five sheep flocks without these clinical signs. These observations suggest a primary aetiological role of this organism in IKC in the Netherlands. M. conjunctivae was also detected on a goat farm with clinical signs of IKC. Experiences in culturing this organism are reported. From each sheep flock at least one strain was isolated and characterised in more detail. All Dutch strains, including two strains of M. conjunctivae isolated from sheep milk, as well as type strain HRC 581, formed film and spots which is in contrast with the description of the type strain. All strains, including the type strain, failed to grow in an anaerobic atmosphere generated by GasPak anaerobic system (BBL). Moraxella ovis was detected in nearly all flocks and was apparently not associated with IKC. Mycoplasma arginini was also isolated from ovine eyes.

Cellular Fatty Acid Composition Comparisons of Haemophilus equigenitalis and Moraxella Species

The cellular fatty acid compositions of Haemophilus equigenitalis and some other species were compared. The cellular fatty acid composition of H. equigenitalis was very similar to the cellular fatty acid compositions of Moraxella species. When the double bond positions in monounsaturated fatty acids were determined by a gas chromatography-mass spectrometry analysis of ditrimethylsilyloxy derivatives, Moraxella species were divided into two groups, the oleic acid group and the cis-vaccenic acid group. The former included eight species (Moraxella atlantae, Moraxella bovis, Moraxella caviae, Moraxella equi, Moraxella lacunata, Moraxella nonliquefaciens, Moraxella osloensis, and Moraxella phenylpyruvica), and the latter included Moraxella catarrhalis, Moraxella ovis, and Moraxella urethralis. H. equigenitalis was closely related to the cis-vaccenic acid group.

Proposal to Divide the Genus Moraxella Lwoff 1939 emend. Henriksen and Bovre 1968 into Two Subgenera, Subgenus Moraxella (Lwoff 1939) Bovre 1979 and Subgenus Branhamella (Catlin 1970) Bovre 1979

The proposal by Henriksen and Bøvre in 1968 to transfer Neisseria catarrhalis, N. caviae, and N. ovis to the genus Moraxella has been supported by recent genetic and chemotaxonomic studies. The proposal by B. W. Catlin (Int. J. Syst. Bacteriol. 20:155-159) in 1970 to transfer N. catarrhalis to a new genus, Branhamella, has not been followed by similar proposals for the other two coccal species, although occasionally they have been referred to informally as members of Branhamella. As a compromise so as to facilitate communication between adherents to these different taxonomies, it is presently proposed to divide the genus Moraxella Lwoff 1939 emend. Henriksen and Bøvre 1968 into two subgenera—subgenus Moraxella (Lwoff 1939) Bøvre 1979 for the six rod-shaped species (Moraxella lacunata, M. bovis, M. nonliquefaciens, M. osloensis, M. phenylpyruvica, and M. atlantae) and subgenus Branhamella for the three coccal species. Strain 199/55 (= ATCC 33078 = NCTC 11227) is here proposed as the neotype strain of Moraxella (Branhamella) ovis (Lindqvist 1960) Henriksen and Bøvre 1968, Bøvre 1979.