Characteristics of Mycoplasma meleagridis sp. n., Isolated from Turkeys

An Update on Novel Taxa and Revised Taxonomic Status of Bacteria Isolated from Domestic Animals Described in 2018 to 2021

Novel bacterial taxonomy and nomenclature revisions can have significant impacts on clinical practice, disease epidemiology, and veterinary microbiology laboratory operations. Expansion of research on the microbiota of humans, animals, and insects has significant potential impacts on the taxonomy of organisms of clinical interest. Implications of taxonomic changes may be especially important when considering zoonotic diseases. Here, we address novel taxonomy and nomenclature revisions of veterinary significance. Noteworthy discussion centers around descriptions of novel mastitis pathogens in Streptococcaceae, Staphylococcaceae, and Actinomycetaceae; bovine reproductive tract pathogens in Corynebacteriaceae; novel members of Mannheimia spp., Leptospira spp., and Mycobacterium spp.; the transfer of Ochrobactrum spp. to Brucella spp.; and revisions to the genus Mycoplasma.

Phylogenetic framework for the phylum Tenericutes based on genome sequence data: proposal for the creation of a new order Mycoplasmoidales ord. nov., containing two new families Mycoplasmoidaceae fam. nov. and Metamycoplasmataceae fam. nov. harbouring Eperythrozoon, Ureaplasma and five novel genera

The genus Mycoplasma, including species earlier classified in the genera Eperythrozoon and Haemobartonella, contains ~ 120 species and constitutes an extensively polyphyletic assemblage of bacteria within the phylum Tenericutes. Due to their small genome sizes and lack of unique characteristics, the relationships among the mycoplasmas/Tenericutes are not reliably discerned. Using genome sequences for 140 Tenericutes, their evolutionary relationships were examined using multiple independent approaches. Phylogenomic trees were constructed for 63 conserved proteins, 45 ribosomal proteins, three main subunits of RNA polymerase and 16S rRNA gene sequences. In all of these trees, Tenericutes species reliably grouped into four main clades designated as the "Acholeplasma", "Spiroplasma", "Pneumoniae" and "Hominis" clusters. These clades are also distinguished based on a similarity matrix constructed based on 16S rRNA gene sequences. Mycoplasma species were dispersed across 3 of these 4 clades highlighting their extensive polyphyly. In parallel, our comparative genomic analyses have identified > 100 conserved signature indels (CSIs) and 14 conserved signature proteins (CSPs), which are uniquely shared by the members of four identified clades, strongly supporting their monophyly and identifying them in molecular terms. Mycoplasma mycoides, the type species of the genus Mycoplasma, and a small number of other Mycoplasma species, formed a strongly supported clade within the "Spiroplasma" cluster. Nine CSIs and 14 CSPs reliably distinguish this clade from all other Mycoplasmatales species. The remainder of the Mycoplasmatales species are part of the "Pneumoniae" and "Hominis" clusters, which group together in phylogenetic trees. Here we are proposing that the order Mycoplasmatales should be emended to encompass only the Mycoplasma species within the "Spiroplasma" cluster and that a new order, Mycoplasmoidales ord. nov., should be created to encompass the other Mycoplasma species. The "Pneumoniae" and the "Hominis" clusters are proposed as two new families, Mycoplasmoidaceae fam. nov., which includes the genera Eperythrozoon, Ureaplasma, and the newly proposed genera Malacoplasma and Mycoplasmoides, and Metamycoplasmataceae fam. nov. to contain the newly proposed genera Metamycoplasma, Mycoplasmopsis, and Mesomycoplasma. The results presented here allow reliable discernment, both in phylogenetic and molecular terms, of the members of the two proposed families as well as different described genera within these families including members of the genus Eperythrozoon, which is comprised of uncultivable organisms. The taxonomic reclassifications proposed here, which more accurately portray the genetic diversity among the Tenericutes/Mycoplasma species, provide a new framework for understanding the biological and clinical aspects of these important microbes.

Mycoplasma infection of geese. 1. Incidence of mycoplasmas and acholeplasmas in geese

This paper presents data about the isolation of members of the order Mycoplasmatales from material of goose origin. Acholeplasma laidlawii strains were isolated from 2 to 8 day old goslings with heavy fibrinous airsacculitis, peritonitis and perihepatitis. Losses reached 30% of the flock by the end of the 8th week of age. Acholeplasma axanthum strains were detected in goose-embryos that died on the 13th day of incubation. A significant loss (up to 60%) of embryos was observed in the flock and some layers died showing fibrinous peritonitis, salpingitis and abdominal airsacculitis. Mycoplasma gallinarum also was isolated from goose-embryo fibroblast tissue cultures. All strains except A. laidlawii caused cytoplasmic vacuolization and intracytoplasmic inclusion bodies in goose-embryo fibroblast tissue cultures. The alteration observed in chicken-embryo fibroblast cell cultures were similar; in addition, the A. laidlawii caused a marked pycnosis of the cells.

Characteristics of Mycoplasma meleagridis sp. n., Isolated from Turkeys

Yamamoto, R. (University of California, Davis), C. H. Bigland, and H. B. Ortmayer. Characteristics of Mycoplasma meleagridis sp. n., isolated from turkeys. J. Bacteriol. 90:47-49. 1965.-A designation is proposed for a pathogenic Mycoplasma species isolated from turkeys. The organism originally was recovered from the air-sac lesion of a turkey poult in 1957, and was designated the "N" strain. Mycoplasma species with identical characteristics have since been recovered from the sinus, trachea, oviduct, vagina, semen, and bursa of Fabricius of turkeys. The organism has been recovered from many turkey flocks throughout the country. Many investigators have confirmed the original finding that this organism is antigenically distinct from other known serotypes of Mycoplasma found in poultry. The species proposed is Mycoplasma meleagridis sp. n.

Antigenic analysis of three strains of Mycoplasma meleagridis of varying pathogenicity

Three strains of Mycoplasma meleagridis of varying pathogenicity were characterized by conventional serologic methods and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The three strains (RY-39A, MC-25B, and RY-39C) did not differ by cross agglutination, immunofluorescence and immunodiffusion tests. However, the strains differed in their protein patterns as determined by SDS-PAGE.

Comparison of seven isolates of Mycoplasma meleagridis

A comparative study of seven isolates of Mycoplasma meleagridis indicated that they were indistinguishable morphologically. Two isolates, E2 and 8M92, induced hemagglutination of red blood cells of several different species while the others did not. Metabolic inhibition, growth inhibition and growth precipitation tests revealed minor differences among the seven isolates. According to these differences, isolates were divided into three groups: antiserum-sensitive isolate 1466, less sensitive isolates N, 8M92, RY3, 529 and E2 and insensitive isolate 1940. One dimensional polyacrylamide gel electrophoresis of cell proteins revealed that all isolates of M. meleagridis had virtually identical patterns and that they were electrophoretically distinct from Mycoplasma gallisepticum and Mycoplasma synoviae. When nonhemagglutinating isolate N, and hemagglutinating isolate E2 were examined by simple immunoelectrophoresis, no differences were detected. However, minor antigenic differences were detected between the two strains by means of two dimensional immunoelectrophoresis.

Isolation and characterization of Mycoplasma and Acholeplasma from apparently healthy and diseased (infectious sinusitis) turkeys

Investigation of 136 turkeys (24 manifesting infra-orbital sinusitis, 112 apparently healthy) resulted in isolation of 79 strains of Mycoplasma and 4 of Acholeplasma. By the disc growth inhibition test with 16 reference antisera of avian serogroups, 55 strains were identified serologically and 28 remained unidentified. Thirteen strains of Mycoplasma gallisepticum, 1 of M. meleagridis, and 2 of Acholeplasma laidlawii were isolated from turkey sinusitis whereas serogroups C (2), D (19), F (8), M. meleagridis (4), M. anatis (4), A. laidlawii (2), and 28 unidentified strains were isolated from apparently healthy turkeys. Three patterns were recognized on the basis of glucose, maltose, and sucrose, fermentation. The most frequent, pattern I, included 13 M. gallisepticum strains whereas 5 M. meleagridis strains belonged to fermentation pattern III. Isolates were also studied for reduction of tetrazolium, methylene blue, potassium tellurite, resistance to methylene blue and sodium taurocholate, and production of arginine deiminase and "film and sports." Inoculation of selected isolates into developing chick embryos revealed that 2 A. laidlawii strains were nonpathogenic and 13 M. gallisepticum, 1 serogroup D and 2 serogroup F strains were pathogenic, causing 50--100% mortality. In vitro antibiotic disc sensitivity tests indicated that rovamycin (solubilized spiramycin) may be recommended for turkey mycoplasmosis. Isolation of 2 A. laidlawii strains from turkey sinusitis and 4 M. anatis strains from apparently healthy turkeys appears interesting.

Differences between cull and normal turkeys in natural infection with Mycoplasma meleagridis at one day of age

The thoracic air sacs of poults at one day of age were examined to compare those of normal, saleable poults with those of sibs culled(1) at hatching at three stages in the laying season. Lesions of airsacculitis were recorded and the air sacs were cultured for mycoplasma. Impression smears of the thoracic air sacs were stained with rabbit anti-Mycoplasma meleagridis serum conjugated with fluorescein isothiocyanate and examined to determine the location and infection rate of the organism. M. meleagridis were observed closely associated with or within epithelial cells of the air sac; within mononuclear cells and as extracellular "microcolonies". The lesion and infection rate of cull poults in most hatches exceeded that of normal poults and infection with M. meleagridis was more often expressed (as a lesion) in cull than in normal poults.

Natural resolution of air sac lesions caused by mycoplasma meleagridis in turkeys

Lesions caused by Mycoplasma meleagridis were followed in one hatch of turkeys from one day to 20(1/2) weeks of age. Air sac lesion incidence increased from 20% at one day to 44% at six weeks of age with a slow decline to 10% at 10 weeks of age. Lesions were detectable on careful examination at 10-20% level to 20 weeks of age on laboratory examination, but at 20(1/2) weeks only 0.07% lesions were found in 1000 turkeys from the same hatch. Air sac lesion severity, based on an arbitrary 0.5,1,2,3,+scale, increased in intensity and spread of air sac involvement from a mean of 1.5 at day old to 2.5 at five weeks of age. This declined to 1.0 at 10 weeks of age and lesions became progressively more faint until careful examination was necessary to detect them in birds 15 weeks and older. The latter would not be considered as a cause of total condemnation. The percentage of Mycoplasma isolations from the respiratory tissues were much higher in birds exhibiting air sac lesions than those in which no typical air sac lesions were visible, as follows. air sacs 51.6 vs. 2.9, lungs 43.3 vs. 4.0, trachea 47.2 vs. 4.6, sinus 38.5 vs. 19.0.

Characterization of a newly identified mycoplasma (Mycoplasma orale type 3) from the human oropharynx

Six mycoplasma strains, isolated under anaerobic conditions from the human oropharynx, were studied by biologic and serologic means. The strains produced nippled colonies with weak hemolytic activity for guinea pig erythrocytes on agar medium. In addition, the strains metabolized arginine with a concomitant alkaline shift in the pH of the medium but did not produce a pH shift when grown in the presence of glucose or urea. The strains failed to reduce 2-3-5 triphenyl tetrazolium and were inhibited by 0.001% methylene blue. In addition, they required fresh yeast extract for growth. When compared by several serologic methods, the strains were found to be related to each other but distinct from 23 serotypes of human, animal, and avian origin. However, one-way serologic relationships between one of the new strains and Mycoplasma orale type 1 and M. salivarium were observed when they were tested by complement fixation. Furthermore, partial relationship of one of the new strains to all of the arginine-utilizing mycoplasma species of human origin was demonstrated with the agar gel diffusion technique. Thus, the new strains appear to constitute a new mycoplasma species, for which the name M. orale type 3 is tentatively proposed. M. orale type 3 accounted for 1.4% of 437 mycoplasma isolates from the oropharynx of adults. The new species probably is a rare member of the normal mycoplasmal flora of man.

Electrophoretic patterns of membrane proteins of Mycoplasma

Cell membranes of Mycoplasma were isolated either by osmotic lysis or by ultrasonic disruption of the organisms. The membranes were dissolved in phenol-acetic acid-water (2:1:0.5, w/v/v), and membrane proteins were separated electrophoretically in polyacrylamide gels containing 5 m urea and 35% (v/v) acetic acid. The electrophoretic patterns of membrane proteins were highly specific for the different Mycoplasma strains examined. The use of this method to prove the identity or dissimilarity of Mycoplasma strains is suggested.