Spiroplasma mirum, a New Species from the Rabbit Tick (Haemaphysalis leporispalustris)

Yunker

et al. 1995

Self Cite

Eight strains of mollicutes were isolated from pooled suspensions prepared from western black-legged ticks (Ixodes puciJicus) collected in Oregon. Morphologic examination by electron and dark-field microscopic techniques showed that each strain consisted of a mixture of motile, tightly coiled helical cells, small coccoid cells with diameters ranging from 300 to 500 nm, and pleomorphic, straight or branched filamentous forms. All cellular forms were surrounded by a single cytoplasmic membrane, and there was no evidence of a cell wall. The organisms were filterable and fastidious in their growth requirements. The optimum temperature for growth was 30°C, but multiplication occurred at temperatures ranging from 23 to 32°C. The strains catabolized glucose but did not hydrolyze arginine or urea. The genome size of strain Y32T (T = type strain) was 2,220 kbp, and the DNA base composition (guanine-plus-cytosine content) of this organism was 25 k 1 mol%. The eight isolates were serologically related to each other but were not related to 37 other type or representative strains belonging to the genus Spiroplasmu. Strain Y32 (= ATCC 33835) is the type strain of Spiroplasma ixodetis sp. nov.Spiroplasmas (class Mollicutes) are helical, motile, wall-less prokaryotes that are associated with a variety of insects, other arthropods, and some plant hosts (11,38,51). Although members of the genus Spiroplasma are usually commensal organisms in their arthropod hosts, several are pathogenic for insects and plants (11, 12,24,29,30).The occurrence of spiroplasmas in hematophagous arthropods was first demonstrated in 1976 when two serologically distinct helical mollicutes (represented by strains SMCA and 277F) were identified in rabbit ticks (Haemaphysalis leporispalustris) (4,41). Strain SMCA and two related strains were eventually characterized as Spiroplasma mirum (39). Strain 277F is serologically and genomically related to Spiroplasma citri and was assigned to subgroup 1-4 in an interim classification scheme for spiroplasmas (21,36,44). Subsequently, spiroplasmas have been identified in blood-sucking members of the Diptera, including horseflies (Tabanus spp.), deerflies (Chrysops spp.), and mosquitoes (Adedes spp., Culex spp., etc.). The current status of these organisms has been summarized in several recent reviews or reports (1, 10, 15, 18, 19,38,45).We described additional isolations of tick-associated spiroplasmas in 1981 (37), including primary isolation of seven helical mollicutes from triturates of the western black-legged tick, Ixodes pacificus. While these organisms were isolated directly in SP-4 spiroplasma culture medium (43), a later report showed that most of the same isolates could be cultivated from stored triturates in several continuously maintained cultured tick cell lines (53). An extensive serologic comparison of the strains isolated from I. pacificus showed that these organisms are closely related to each other but distinct from other previously described spiroplasmas. Strain Y32T (T = type strain) was selected ...

Section: Resultsmentioning

confidence: 66%

Section: Spiroplasma Strainsmentioning

confidence: 99%

See 1 more Smart Citation

Spiroplasma ixodetis sp. nov., a New Species from Ixodes pacificus Ticks Collected in Oregon

Yunker

et al. 1995

Self Cite

“…Three groups (111, IV, and V) have been given species epithets (S.Jloricola [lo], S. apis [MI, and S . mirum [24], respectively). In addition, following recommendations by the International Committee on Systematic Bacteriology Subcommittee on the Taxonomy of Mollicutes (15) for elevation of group I subgroups to species levels, we recently characterized representatives of subgroups I-2,1-3, and 1-8 as Spiroplasma melliferum (9), Spiroplasma kunkelii (29), and Spiroplasma phoeniceum (20), respectively.…”

mentioning

confidence: 91%

Revised Group Classification of the Genus Spiroplasma (Class Mollicutes), with Proposed New Groups XII to XXIII

Clark

et al. 1987

Self Cite

Fourteen spiroplasma strains, primarily of insect origin, were analyzed according to criteria previously proposed for description of new serogroups of the genus Spiroplasma. When tested by reciprocal metabolism inhibition, growth inhibition, and deformation serological procedures, 12 of the strains were serologically unrelated to each other and to representative strains previously assigned to groups I to XI and subgroups 1-1 to 1-8. Examination by dark-field and electron microscopy indicated that each of the 12 strains possessed morphological features typical of spiroplasmas (helicity , motility, lack of a cell wall, and absence of periplasmic fibrils). All strains were resistant to 500 U of penicillin per ml and catabolized glucose but were unable to hydrolyze urea. Ability to hydrolyze arginine varied among strains. The guanine-plus-cytosine contents of the deoxyribonucleic acid of the 12 strains varied from 24 to 29 mol%. Two other strains (MQ-6 and Ar-1357) shared only a partial serological relationship to strain CC-1 (group XVI), suggesting that this group may consist of an assemblage of heterogeneous serovars. On the basis of the unique serological distinctions and other properties reported herein, we propose that the 12 representative strains be assigned new consecutive group designations XI1 to XXIII.

“…Group IV appeared to be a widely distributed cluster of spiroplasmas, some of whose members, including type strain B31 (Spiroplasma apis), were pathogenic (19, 20) for honeybees @pis mellifera). Groups V (Spiroplasma mirum [30]) and VI (29) were associated with ticks. Thus, each of the first six established spiroplasma groups appeared to possess unusual biological and/or ecological properties.…”

mentioning

confidence: 99%

Spiroplasma monobiae sp. nov. from the Vespid Wasp Monobia quadridens (Hymenoptera: Vespidae)

Whitcomb

et al. 1993

Self Cite

Spiroplasma strain MQ-lT (T = type strain) from the hemolymph of the vespid wasp Monobia quadridens differed serologically from other spiroplasma species, groups, and subgroups. Cells of strain MQ-lT were helical and motile and possessed a single cytoplasmic membrane, with no evidence of a cell wall. The organism grew in conventional mycoplasma medium, in serum fraction, SM-1, MlD, and SP-4 liquid media, and on SP-4 solid medium in either aerobic or anaerobic environments. The optimum temperature for growth was 32"C, but multiplication occurred over a wide temperature range (10 to 37°C). The doubling time at 32°C in M1D medium was 1.9 h. Strain MQ-lT catabolized glucose but hydrolyzed neither arginine nor urea. Previous work showed that strain MQ-lT has a unique methylase, previously known only in eucaryotes. Also, strain MQ-lT induces production of tumor necrosis factor in bone marrow macrophages. The guanine-plus-cytosine content of the DNA was 28 f 1 mol%. The genome size of strain MQ-lT was 940 kb (627 MDa); a similar strain, MQ-8, had a genome size of 985 kb (657 MDa). Strain MQ-lT and its allies have the smallest genomes known in the genus Spiroplasma. Strain MQ-1 (= ATCC 33825) is designated the type strain of a new species, Spirophsma monobiae.The genus Spiroplasma (36), originally thought to consist of plant pathogens (22), was later shown, largely through the efforts of T. B. Clark and his associates (7,15), to be associated with arthropods. As the immense diversity of this genus unfolded, numerous interesting properties emerged. For example, group I organisms (2) were the only spiroplasmas found to be associated with plant disease or with plant-sucking bugs. Yet, the subgroup 1-2 spiroplasma, Spiroplasma melliferum (8), which was closely related to the plant spiroplasmas, was primarily associated with bees. One subgroup of this cluster (subgroup I-6), which appears to occur in the insect-plant surface habitat (15), had a guanineplus-cytosine (G+C) content that was higher than the G+C contents of its cohort subgroups (5). Another spiroplasma (subgroup I-4), isolated only once, appeared to be associated with ticks. Group I1 spiroplasmas (34) produced sex ratio abnormalities in Drosophila flies. Group 111 spiroplasmas (9) (Spiroplasma jloricola) proved to be associated with magnoliaceous flowers and their beetle and fly visitors and to have idiosyncratic metabolic pathways (6) that were readily studied because of the rapid growth of the species. Group IV appeared to be a widely distributed cluster of spiroplasmas, some of whose members, including type strain B31 (Spiroplasma apis), were pathogenic (19, 20) for honeybees @pis mellifera). Groups V (Spiroplasma mirum [30]) and VI (29) were associated with ticks. Thus, each of the first six established spiroplasma groups appeared to possess unusual biological and/or ecological properties.For some time, the group VII spiroplasmas, strain MQ-lT (T = type strain) and its allies, appeared to be exceptions to the emerging uniqueness of newly discovered strains. H...