Spiroplasmas: Diversity of Arthropod Reservoirs and Host-Parasite Relationships

Strain CCHT (T = type strain), a helical procaryote that was isolated from floral surfaces of Culystegiu hederuceu (Convolvulaceae) in Jiangsu, People's Republic of China, was found to be a sterol-requiring member of the class Mullicutes. The cells of strain CCHT were small, motile helices that were devoid of a cell wall or periplasmic fibrils. The organism passed through filters with average pore diameters of 300 and 220 nm. Strain CCHT grew rapidly in liquid media having simple compositions, reaching stationary growth phase within 24 h at 30°C. Growth occurred at temperatures ranging from 25 to 37OC. The organism fermented glucose and other sugars with acid production and showed weak arginine hydrolysis. It did not hydrolyze urea. In preliminary electrophoretic analyses, the cell protein patterns of strain CCHT were distinct from those of eight other spiroplasmas commonly found on flowers. Using enzyme-linked immunosorbent assays and antisera to strain CCHT, we found no serological relationship to antigens of the 23 previously recognized spiroplasma groups or species. These distinctions were confirmed by performing reciprocal metabolism inhibition and deformation serological tests, in which we used antigens and antisera to representatives of spiroplasma groups I through XXIII. The base composition (guanine-plus-cytosine content) of the DNA of strain CCHT was about 29.0 mol%. On the basis of these findings, we propose that spiroplasma strain CCH (= ATCC 43960) be designated group XXIV and the type strain of a new species, Spiroplasrnu chinense.Many species of the genus Spiroplasma (class Mollicutes) have been isolated from flower surfaces (2, 8-11, 17, 18, 25-28, 34). Despite the frequency of these isolations, these helical wall-less procaryotes are associated primarily with arthropods and insects (7,34); therefore, their occurrence on flowers probably results from seasonal insect activities. The spiroplasma strains associated with plants and insects have proved to be extraordinarily diverse, and their classification has presented many problems. However, on the basis of their serological and genomic properties, spiroplasmas are now classified into groups or subgroups (25,30,31), which may be converted to species by fulfilling the minimal standards for description of species of Mollicutes (14, 30).In the spring of 1985, flowers of 23 plant species were collected in a field in Jiangsu, People's Republic of China; spiroplasmas were isolated and cultivated from the flower surfaces of 4 of these species (X. D. Ye, M.S. thesis, Nanjing Agricultural University, Nanjing, People's Republic of China, 1987). After purification by cloning procedures, one of the isolates from flowers of Calystegia hederacea (a bindweed and a member of the Convolvulaceae) gave rise to a strain, strain CCHT (T 6 type strain), that proved to be serologically unrelated to spiroplasmas belonging to previously described groups. Subsequently, we accumulated sufficient biological and genomic data to fulfill the minimal requirements for description...

Section: Resultsmentioning

confidence: 99%

Section: Many Species Of the Genus Spiroplasma (Class Mollicutes)mentioning

confidence: 99%

Spiroplasma chinense sp. nov. from Flowers of Calystegia hederacea in China

Guo

Chen

Whitcomb

et al. 1990

“…In this scheme, group I was subdivided into eight subgroups (1-1 to I-8), including a recently described (21) plant-pathogenic spiroplasma (strain P40 and allied spiroplasmas, subgroup [1][2][3][4][5][6][7][8]. Three groups (111, IV, and V) have been given species epithets (S.Jloricola [lo], S. apis [MI, and S .…”

mentioning

confidence: 99%

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

Tully

Rose

Clark

et al. 1987

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.

“…It is also possible that genetic manipulation could produce a specific pathogen. On the other hand, the wide occurrence of group XVI spiroplasmas in the insect world (13,20), together with a possibility that they may be acquired from plant surfaces by the activities of adult insects (27), may present environmental concerns if the spiroplasmas are used for biological control. Much more needs to be learned about the biological specificity of spiroplasma serotypes of biting insects, including those occurring in tabanid flies (14,16,25,35).…”

Section: Resultsmentioning

confidence: 99%

Spiroplasma cantharicola sp. nov., from Cantharid Beetles (Coleoptera: Cantharidae)

Whitcomb

Chastel²,

Abalain-Colloc³

et al. 1993

Spiroplasma strain CC-lT, isolated from the gut of the soldier beetle Cantharis carulinus, was serologically distinct from other spiroplasma species, groups, and subgroups. Cells of strain CC-lT were shown by light microscopy to be helical, motile filaments. Electron microscopy showed that the cells were bounded by a single cytoplasmic membrane, with no evidence of a cell wall. The organism was insensitive to penicillin. Strain CC-lT grew well in SM-1, MlD, and SP-4 liquid media under aerobic or anaerobic conditions. The strain also grew in 1% serum fraction medium. Optimal growth occurred at 32"C, with a doubling time of 2.6 h, but the strain multiplied at temperatures of 10 to 37°C. Strain CC-lT produced acid from glucose but hydrolyzed neither arginine nor urea. The guanine-plus-cytosine (G+C) content of the DNA was 26 f 1 mol%. Other uncloned isolates from C. carolinus exhibited similar or identical serological patterns. On the basis of the data presented here, strain CC-lT (= ATCC 43207), previously proposed as the representative strain of subgroup XVI-1, is designated the type strain of a new species, Spiroplasma cantharicolu.In 1982, adults of the soldier beetle, Cantharis carolinus (Coleoptera: Cantharidae), were found to harbor spiroplasmas in the gut but not in the hemolymph. Strain CC-lT, derived from one of five isolates, was chosen as a representative of the cluster, which was designated group XVI (33) and, more recently, subgroup XVI-1 (1, 4). This group, however, eventually turned out to be complex and to contain organisms not only from beetles but from mosquitoes and flowers also. Abalain-Colloc and colleagues (1,4) characterized group XVI spiroplasmas by serology, DNA-DNA homology, and polyacxylamide gel electrophoresis, and proposed recognition of three subgroups. In this classification, the cluster of spiroplasma strains and isolates from C. carolinus was designated subgroup XVI-1. Chaste1 and his colleagues, in 1985, discovered (11) a large assemblage of serologically diverse spiroplasma strains in mosquitoes in France that partially cross-reacted with strain CC-lT. These spiroplasmas were later designated subgroup XVI-3 (1,4). In 1983, an apparently unrelated strain (CB-1) had been isolated from the gut of a Cantharis bilineatzm adult. Although minor reciprocal cross-reactivities between the two strains were observed when the strains were compared by metabolism inhibition, deformation, and growth inhibition serology, the two strains were at first regarded (unpublished data) as representatives of separate spiroplasma groups. However, studies of Shaikh et al. (28) on spiroplasma carriage by mosquitoes in Alabama revealed a strain, AEF-2, that showed substantial cross-reactivity between strains CC-lT and CB-1, indicating that strains CC-lT and CB-1 belonged to a single spiroplasma group. Strain CB-1 was subsequently assigned to subgroup XVI-2 (1,4). In this paper, we describe taxonomic studies on strain CC-lT (subgroup XVI-1 of * Corresponding author.