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Natural Killer (NK) cells are among the first effectors to directly contact influenza and influenza-infected cells and their activation affects not only their intrinsic functions, but also subsequent CD8+ T cell responses. We utilized a NK cell depletion model to interrogate the contribution of NK cells to the development of anti-influenza CD8+ T cell memory. NK cell ablation increased the number of influenza-specific memory CD8+ T cells in the respiratory tract and lung-draining lymph node. Interestingly, animals depleted of NK cells during primary influenza infection were protected as well as their NK-intact counterparts despite significantly fewer reactivated CD8+ T cells infiltrating the respiratory tract after lethal, heterosubtypic challenge. Instead, protection in NK-deficient animals seems to be conferred by rapid reactivation of an enlarged pool of lung tissue-resident (TRM) memory cells within two days post challenge. Further interrogation of how NK cell ablation enhances respiratory TRM indicated that TRM development is independent of global and NK cell derived IFN-γ. These data suggest that reduction in NK cell activation after vaccination with live, non-lethal influenza virus increases compartmentalized, broadly protective memory CD8+ T cell generation and decreases the risk of CD8+ T cell-mediated pathology following subsequent influenza infections.

Significant changes have been made in the systematics of the genus Spiroplasma (class Mollicutes) since it was expanded by revision in 1987 to include 23 groups and eight sub-groups. Since that time, two additional spiroplasmas have been assigned group numbers and species names. More recently, specific epithets have been assigned to nine previously designated groups and three sub-groups. Also, taxonomic descriptions and species names have been published for six previously ungrouped spiroplasmas. These six new organisms are: Spiroplasma alleghenense (strain PLHS-1T) (group XXVI), Spiroplasma lineolae (strain TALS-2T) (group XXVII), Spiroplasma platyhelix (strain PALS-1T) (group XXVIII), Spiroplasma montanense (strain HYOS-1T) (group XXXI), Spiroplasma helicoides (strain TABS-2T) (group XXXII) and Spiroplasma tabanidicola (strain TAUS-1T) (group XXXIII). Also, group XVII, which became vacant when strain DF-1T (Spiroplasma chrysopicola) was transferred to group VIII, has been filled with strain Tab 4c. The discovery of these strains reflects continuing primary search in insect reservoirs, particularly horse flies and deer files (Diptera: Tabanidae). In the current revision, new group designations for 10 spiroplasma strains, including six recently named organisms, are proposed. Three unnamed but newly grouped spiroplasmas are strain TIUS-1 (group XXIX; ATCC 51751) from a typhiid wasp (Hymenoptera: Tiphiidae), strain BIUS-1 (group XXX; ATCC 51750) from floral surfaces of the tickseed sunflower (Bidens sp.) and strain BARC 1901 (group XXXIV; ATCC 700283). Strain BARC 2649 (ATCC 700284) from Tabanus lineola has been proposed as a new sub-group of group VIII. Strains TIUS-1 and BIUS-1 have unusual morphologies, appearing as helices at only certain stages in culture. In this revision, potentially important intergroup serological relationships observed between strain DW-1 (group II) from a neotropical Drosophila species and certain sub-group representatives of group I spiroplasmas are also reported.

Spiroplasma strain HYOS-1Twas isolated from a tabanid fly, Hybomitra opaca. The organism was serologically distinct from other spiroplasma species, groups, and subgroups and was recently designated the representative of spiroplasma group XXXI. The cells of strain HYOS-1T, as determined by light microscopy, were long motile helices. Electron microscopic examination revealed wall-less cells delimited by a single membrane. The cells passed through 450- and 300-nm filter pores with a 10-fold reduction in titer, but failed to pass through 100-nm pores. Strain HYOS-1Tgrew very well in most conventional medium formulations for spiro-plasmas or other mollicutes. The organism grew at temperatures ranging from 5 to 41°C, and the optimum temperature was 32°C. The doubling time at the optimum temperature was 0.7 h, one of the shortest values obtained for members of the genus Spiroplasma. The strain catabolized glucose and hydrolyzed arginine but not urea. Growth of the organism was stimulated by cholesterol and serum, but the strain was nevertheless able to grow in the absence of sterols or serum. The guanine-plus-cytosine content of the DNA was about 28 ± 1 mol%, and the genome size was 1,225 kbp. On the basis of the experimental results reported here and previously reported data, group XXXI strain HYOS-1 (= ATCC 51745) is designated the type strain of a new species, Spiroplasma montanense.

Spiroplasma strain PUP-1Twas isolated from the gut fluids of a firefly beetle (Photuris pennsylvanicus) collected in Maryland. Cells of the strain were shown by dark-field microscopy to be helical, motile filaments. Ultrastructural examination by electron microscopy revealed filamentous cells bounded by a single cytoplasmic membrane and no evidence of a cell wall. The cells were not sensitive to 500 U of penicillin per ml and grew under aerobic conditions in M1D, SP-4, and M-2 broth formulations, as well as in conventional mycoplasma medium. The doubling times at 15, 20, 25, and 30°C were 83.1, 32.0, 14.9, and 9.8 h, respectively. Suboptimal growth occurred at 37°C, and no growth was apparent in cultures maintained at 10 or 40°C. The organism required cholesterol for growth and produced acid from glucose, fructose, and trehalose; arginine and urea were not hydrolyzed. The results of previous serological analyses of strain PUP-1Tindicated that the organism was not related to the then currently established Spiroplasma species or group representatives, and the organism was classified as the representative of group XIX. Additional testing of strain PUP-1Tagainst recently recognized Spiroplasma species or group representatives by both metabolism inhibition and deformation tests confirmed the unique serological status of the organism. The guanine-plus-cytosine content of the DNA was 26 ± 1 mol%, and the genome size was 1,375 kbp. These values clearly differentiate strain PUP-1Tfrom group XXI strain W115, with which it cross-reacted reciprocally at a low level in deformation and metabolism inhibition tests. We propose that strain PUP-1 (= ATCC 43206) should be recognized as the type strain of a new species, Spiroplasma lampyridicola.

Spiroplasma strain PLHS-1T from the gut of a common scorpion fly (Panorpa helena) collected in the West Virginia Allegheny Mountains was distinct from other spiroplasma species, groups, and subgroups as determined by reciprocal serological metabolism inhibition and deformation tests. However, when this strain was used as an antigen, it cross-reacted extensively with representatives of other groups. Light microscopy and/or electron microscopy of cells of strain PLHS-1T revealed helical motile cells surrounded by a single cytoplasmic membrane. The strain was resistant to penicillin, which confirmed that it had no cell wall. The organism grew well in M1D and SP-4 liquid media, in 1% serum fraction medium, and in conventional horse serum medium. The optimum temperature for growth was 30°C, at which the doubling time was 6.4 h. Multiplication occurred at temperatures from 10 to 32°C. Strain PLHS-1T catabolized glucose, hydrolyzed arginine but not urea, and required sterol for growth. The guanine-plus-cytosine content of the DNA was 31 ± 1 mol%, and the genome size was 1,465 kbp. Strain PLHS-1 (= ATCC 51752) is designated the type strain of a new species, Spiroplasma alleghenense.

Four spiroplasma strains, DF-1T, TG-1T, TABS-2T, and TAUS-1T, all of which were isolated from deerflies or horseflies (Diptera: Tabanidae), were serologically distinct from previously described spiroplasma species, groups, and subgroups. Strain DF-1Toriginated from a Maryland deerfly (Chrysops sp.); strain TG-1Twas isolated from a Maryland horsefly (Tabanus gladiator); strain TAUS-1Toriginated from a member of the Tabanus abdominalis-limbatinevris complex of horseflies collected in Maryland; and strain TABS-2Twas isolated from a horsefly (Tabanus abactor) collected in Oklahoma. Cells of all of the strains appeared to be helical and motile when they were examined by dark-field microscopy. Cells of strain DF-1Tgrowing in M1D medium were short helices with less than six turns; the helical cells of the other strains were long and usually had six or more turns. The short cells of strain DF-1Tpassed through 450- and 300-nm filter pores with no reduction in titer, but the longer cells of the other strains were partially retained by 450-nm-pore-size filters. Electron microscopic examination of all of the strains revealed wall-less cells surrounded only by a single cytoplasmic membrane. All of the strains grew well in SP-4 liquid media and in conventional mycoplasma or M1D media supplemented with horse or fetal bovine serum. Strains TABS-2T, TAUS-1T, and DF-1Trequired serum or sterol for growth, but strain TG-1Twas able to grow in the absence of serum or sterol. The optimum temperatures for growth of the four strains varied from 30 to 32°C, and growth occurred at 10 to 37°C. All of the strains catabolized glucose but did not hydrolyze urea. Only strain DF-1Thydrolyzed arginine. The guanine-plus-cytosine contents of the DNAs of the strains were: DF-1T, 29 ± 1 mol%; TG-1T, 26 ± 1 mol%; TABS-2T, 27 ± 1 mol%; and TAUS-1T, 26 ± mol%. The genome sizes of strains DF-1Tand TAUS-1Twere 1,270 and 1,375 kbp, respectively. Strain DF-1 (= ATCC 43209), the representative of spiroplasma subgroup VIII-2, is designated the type strain of a new species, Spiroplasma chrysopicola. We also propose that strain TG-1T(= ATCC 43525T), the designated representative of group XXIII, should be placed in a new species, Spiroplasma gladiatoris. In addition, group XXXII spiroplasma strain TABS-2 (= ATCC 51746) is designated the type strain of Spiroplasma helicoides sp. nov., and group XXXIII representative strain TAUS-1 (= ATCC 51747) is designated the type strain of another new species, Spiroplasma tabanidicola.

Spiroplasma strain TN-1T (T = type strain), a strain serologically distinct from other spiroplasma species, groups, and subgroups, was isolated from the gut of a horsefly (Tabanus nigrovittatus) from a barrier island off the coast of North Carolina. Related strains were isolated from other Tabanus spp., T. atratus, T. americanus, T. gladiator, T. lineola, T. sulcifrons, and T. zythicolor, from coastal Georgia. Cells of strain TN-1T in culture were helical and motile with an average of 5 to 10 helical turns per cell. Electron microscopic studies determined that the cells of strain TN-1T were surrounded by a single cytoplasmic membrane, and there was no evidence of a cell wall. The spiroplasma grew well in MID and SP-4 liquid media. Serum fraction (1%) medium and conventional horse serum medium also supported growth of strain TN-1T. Fried-egg colonies were not produced; instead, the strain produced small diffuse colonies that were surrounded by satellite growth. The optimum temperature for growth was 32°C, but multiplication was observed at temperatures from 10 to 41°C. The doubling time at the optimum temperature (32°C) was 1.6 h. No growth was observed at 5 or 43°C. Spiroplasma strain TN-1T passed through 220-nm filter pores but failed to pass through 100-nm filter pores. Strain TN-1T catabolized glucose but hydrolyzed neither arginine nor urea. The guanine-plus-cytosine content of the DNA was about 25 ± 1 mol%, and the genome size was 1,370 kbp. Based on results from this study and previously published data, strain TN-1T (= ATCC 43211) (group XVIII) is designated the type strain of a new spiroplasma species, Spiroplasma litorale.

Spiroplasma strain LD-1T (T = type strain), which was isolated from the gut of a Colorado potato beetle (Leptinotarsa decemlineata) larva collected in Maryland, was serologically distinct from other spiroplasmas. Similar isolates were obtained from other L. decemlineata specimens collected in various parts of North America, in Poland, and in other eastern European countries and from Leptinotarsa texana specimens collected in Texas. Cells of strain LD-1T, which in early passages were spiral, exhibited exceptionally rapid translational motility. This rapid motility and the spiral shape were lost after extended passage in culture. The organism required serum for growth. Originally isolated in coculture with insect cells in DCCM medium, strain LD-1T adapted to several media in the absence of cocultured cells. Use of anaerobic conditions allowed primary isolation in a variety of media. The organism did not grow in serum-free media containing 2% serum fraction. Optimal growth in M1D medium occurred at 30 to 37°C (doubling time, 7.2 h). On solid M1D medium containing 2.0% Noble agar (pH 6.25) at 30°C, strain LD-1T produced discrete colonies with numerous satellites. Strain LD-1T hydrolyzed arginine, but did not utilize urea; there was evidence of weak fermentation of glucose. The guanine-plus-cytosine content of the DNA was determined to be 25 ± 1 mol%, and the genome size was 1,085 kb. The results of extensive studies of the ecology of this spiroplasma suggest that it is host specific for Leptinotarsa beetles. Strain LD-1 (= ATCC 43213) is designated the type strain of a new species, Spiroplasma leptinotarsae.

Spiroplasma sp. strain EA-1(T) (T = type strain) (subgroup VIII-1), which was isolated from the syrphid fly Eristalis arbustorum, was serologically distinct from other spiroplasma species, groups, and subgroups, The cells of this strain, as revealed by dark-field light microscopy, were short, helical, and motile. An electron microscopic examination revealed wall-less cells delimited by a single membrane. The unusually short cells passed through 220-nm filter pores with no reduction in titer. The organisms grew well in SM-1, M1D, and SP-4 liquid media. Growth also occurred in conventional horse serum medium and 1% serum fraction medium. Strain EA-1(T) grew at temperatures between 10 and 41 degrees C, and optimum growth occurred at 32 degrees C. The doubling time at the optimal temperature was 1.0 h. The strain catabolized glucose and hydrolyzed arginine but did not hydrolyze urea. The guanine-plus-cytosine content of the DNA was 30 +/- 1 mol%. The genome size was about 1,230 kbp. Strain Ea-1 (= ATCC 33826), which represents subgroup VIII-1, is designated the type strain of a new species, Spiroplasma syrphidicola.

Initially, strain CUAS-1T (T = type strain), which was isolated from a frozen triturate of Culex annulus mosquitoes collected in Taiwan, was thought to be a member of spiroplasma group VII. This placement was based on the spiroplasma deformation test titer observed when strain CUAS-1T spiroplasmas were tested with Spiroplasma monobiae MQ-1T antiserum. The results of subsequent reciprocal spiroplasma deformation, metabolism inhibition, and growth inhibition tests clearly revealed that strain CUAS-1T is not serologically related to previously described spiroplasma groups (groups I to XXIV) and thus is a representative of a new group, group XXV. Strain CUAS-1T was characterized by using the minimal standards for mollicute species descriptions. During logarithmic-phase growth, strain CUAS-1T cells are characteristically very short helices with 1.5 to 2 helical turns (1 to 2 microns), highly motile, and bounded by a single trilaminar membrane and form granular colonies with satellites when the organism is grown aerobically on MID medium containing 1.6% agar. Growth in MID broth occurs at temperatures ranging from 10 to 37 degrees C, and the optimum temperature is 30 degrees C. Substrate utilization tests revealed that cholesterol is required for growth, that glucose is hydrolyzed, and that arginine is not hydrolyzed both in the presence and in the absence of glucose. The genome of strain CUAS-1T is 1,080 kbp long, and the guanine-plus-cytosine content is 26 +/- 1 mol%. On the basis of the results of our studies we propose that strain CUAS-1T (group XXV) should be placed in a new species, Spiroplasma diminutum. Strain CUAS-1 (= ATCC 49235) is the type strain of S. diminutum.

Following influenza infection, natural killer (NK) cells function as interim effectors by suppressing viral replication until CD8 T cells are activated, proliferate, and are mobilized within the respiratory tract. Thus, NK cells are an important first line of defense against influenza virus. Here, in a murine model of influenza, we show that virally-induced IL-15 facilitates the trafficking of NK cells into the lung airways. Blocking IL-15 delays NK cell entry to the site of infection and results in a disregulated control of early viral replication. By the same principle, viral control by NK cells can be therapeutically enhanced via intranasal administration of exogenous IL-15 in the early days post influenza infection. In addition to controlling early viral replication, this IL-15-induced mobilization of NK cells to the lung airways has important downstream consequences on adaptive responses. Primarily, depletion of responding NK1.1+ NK cells is associated with reduced immigration of influenza-specific CD8 T cells to the site of infection. Together this work suggests that local deposits of IL-15 in the lung airways regulate the coordinated innate and adaptive immune responses to influenza infection and may represent an important point of immune intervention.

Two mollicutes (strains 0502T [T = type strain] and J233T), which were isolated from the surfaces of broccoli (Brassica oleracea var. italica) plants or the crown tissues of the coconut palm (Cocos nucifera), were capable of sustained growth in serum-free (or cholesterol-free) mycoplasma broth media. Examination by electron and dark-field microscopic techniques revealed that the cells of each strain were small, nonhelical, nonmotile, pleomorphic, and coccoid and that each cell was surrounded by a single cytoplasmic membrane. No evidence of a cell wall was found. The organisms were filterable and grew rapidly in most conventional mycoplasma culture medium formulations containing horse or fetal bovine sera under either aerobic or anaerobic conditions. The optimum temperature for growth of both organisms was 30 degrees C, but multiplication occurred over a temperature range from 18 to 37 degrees C. Both strains catabolized glucose, but did not hydrolyze arbutin, arginine, or urea. The genome size of strain 0502T was 1,215 kbp, and the DNA base composition (guanine-plus-cytosine content) was 35.5 mol%. The genome size of strain J233T was 1,610 kbp, and the DNA base composition was 30.0 mol%. The two isolates were not serologically related to each other or to the type strains of 11 previously described Acholeplasma species. Strain 0502 (= ATCC 49388) is the type strain of Acholeplasma brassicae sp. nov., and strain J233 (= ATCC 49389) is the type strain of Acholeplasma palmae sp. nov.

Spiroplasma strain CC-1T, isolated from the gut of the soldier beetle Cantharis carolinus, was serologically distinct from other spiroplasma species, groups, and subgroups. Cells of strain CC-1T 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-1T grew well in SM-1, M1D, 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-1T produced acid from glucose but hydrolyzed neither arginine nor urea. The guanine-plus-cytosine (G+C) content of the DNA was 26± 1 mol%. Other uncloned isolates from C. carolinus exhibited similar or identical serological patterns. On the basis of the data presented here, strain CC-1T (= ATCC 43207), previously proposed as the representative strain of subgroup XVI-1, is designated the type strain of a new species, Spiroplasma cantharicola.

DNA-DNA hybridization experiments were carried out in order to clarify the taxonomic relationships between the F38 group of caprine mycoplasmas, the established etiologic agents of classical contagious caprine pleuropneumonia, and Mycoplasma capricolum, an organism associated with septicemia, arthritis, and mastitis in goats and sheep. The taxonomic status of the F38 group has been uncertain, principally because of the serological, genomic, and other properties which it shares with M. capricolum. Tritium-labeled DNAs from the M. capricolum type strain (California kid) and from prototype strain F38 were hybridized with unlabeled DNAs from these two strains and from four other isolates belonging to each group. The results showed consistent DNA relatedness values of about 70% between the F38 and M. capricolum groups, compared with levels of relatedness of about 90 and 85%, respectively, for the strains within each group. In addition, the results of comparisons of these 10 strains in which growth inhibition and immunofluorescence tests were used confirmed the previously reported serological relationships between the two groups and reinforced other observations concerning their shared genomic and cell membrane characteristics, indicating that there is a close taxonomic relationship. However, as the 70% DNA relatedness values between the M. capricolum and F38 groups also indicate a degree of genomic difference inconsistent with a relationship at the species level, we conclude that our findings support previous proposals for classification of the F38 group as a subspecies of M. capricolum. In view of the prospective diagnostic problems, particularly those arising from the serological similarities of two putative subspecies, we believe that further studies should be performed to define additional phenotypic and genotypic properties that would allow more rapid and specific differentiation of the F38 group mycoplasmas.

Spiroplasma strain M55, isolated from a fall flower in Maryland, showed patterns of partial serological cross-reactivity with the other seven group I spiroplasma subgroups but was not serologically related to other spiroplasma groups. Strain M55 had less than 70% DNA-DNA homology with group I subgroups previously assigned binomial names and was unique among the group I subgroups in possessing a higher guanine-plus-cytosine content in its DNA (28 ± 1 mol%, versus 26 ± 1 mol% for other group I subgroups). The genome size was 1,850 kb (1,233 MDa). Extensive data on the metabolism of strain M55 and the community ecology of this and similar strains have been reported. These circumstances fulfill criteria proposed by the Subcommittee on the Taxonomy of Mollicutes for elevation of mollicute subgroups to species status. Accordingly, strain M55 was characterized according to proposed minimal standards for species descriptions. Cells of strain M55 were shown by light microscopy to be helical, motile filaments. Electron microscopy showed that the cells possessed no cell wall and were bounded by a single membrane; they were insensitive to penicillin (1,000 U/ml). Strain M55 was culturable in M1D and SP-4 liquid media under aerobic (with or without enhanced carbon dioxide) or anaerobic environments. Optimal growth occurred at 30°C, with a doubling time of 7.2h. Growth occurred from 15 to 37°C but not at 10 or 42°C. Strain M55 did not utilize urea or hydrolyze arginine but did produce acid from glucose. As a consequence of these studies, strain M55 is designated the type strain (M55T; ATCC 33502T) of a new species, Spiroplasma insolitum.

Spiroplasma strain CN-5T (T = type strain), isolated from the gut of the cetoniine scarabaeid beetle Cotinus nitida, was serologically distinct from other spiroplasma species, groups, and subgroups. Cells of strain CN-5T were shown by light microscopy to be helical, motile filaments. Cells in early passages exhibited strong translational motility that tended to be lost in later passages. Electron microscopy showed that the cells were bounded by a single cytoplasmic membrane with no evidence of a cell wall. The organism was not susceptible to penicillin. Strain CN-5T grew well in SM-1, M1D, and SP-4 liquid media and on solid SP-4 medium under aerobic or anaerobic conditions. The doubling time at 30°C, the optimum temperature, was 4.3 h. The strain also grew in 1% serum fraction medium. Strain CN-5T produced acid from glucose and catabolized arginine, but did not hydrolyze urea. The guanine-plus-cytosine content of the DNA was 29 ± 1 mol%. The genome size was 1,770 kb (1,186 MDa). Other uncloned isolates obtained from C. nitida or the cetoniine hermit flower beetle Osmoderma eremicola exhibited similar or identical serological patterns. Since no other hosts were discovered in extensive studies, strain CN-5T (previously designated group IX) appears to represent a cluster of relatively host-specific cetoniine beetle-associated strains. Strain CN-5 (= ATCC 33827) is designated the type strain of a new species, Spiroplasma clarkii.

Spiroplasma strain MQ-1T (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-1T 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, M1D, 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-1T catabolized glucose but hydrolyzed neither arginine nor urea. Previous work showed that strain MQ-1T has a unique methylase, previously known only in eucaryotes. Also, strain MQ-1T induces production of tumor necrosis factor in bone marrow macrophages. The guanine-plus-cytosine content of the DNA was 28 ± 1 mol%. The genome size of strain MQ-1T was 940 kb (627 MDa); a similar strain, MQ-8, had a genome size of 985 kb (657 MDa). Strain MQ-1T 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, Spiroplasma monobiae.

Strain PPAV, a filamentous but nonhelical mollicute, was isolated from aborted apple seeds in France in late 1979. This organism grew well in SP-4 broth, fermented glucose, and required sterol for growth, and most of its properties suggested that it belonged to the genus Mycoplasma. However, it was serologically distinct; in addition, unlike other Mycoplasma species, genome measurements consistently yielded values of about 1,000 MDa (ca. 1,500 kbp), and the organism had a growth temperature optimum of 43 degrees C. A comparison of strain PPAV 16S rRNA sequences with those of other mollicutes revealed a high degree of sequence similarity to a strain of Mycoplasma iowae, which is commonly encountered in poultry. This relationship was confirmed by performing a restriction endonuclease pattern analysis and DNA-DNA hybridization tests. The genome size of type strain 695 of M. iowae was determined to be about 1,000 MDa (1,500 kbp) by renaturation kinetics, a value which is much higher than any other value known in the genus. Additional measurements by pulsed-field gel electrophoresis yielded values of 1,300 kbp for both strain PPAV and M. iowae. Subsequent phenotypic comparisons supported this relationship. Serologic tests with strain PPAV and other strains of M. iowae confirmed the findings of other investigators that this species is serologically heterogeneous. The high optimum temperature for growth of strain PPAV was also shared by a number of M. iowae isolates. Genome size is an inappropriate character for taxonomic assignment to the family Mycoplasmataceae because strain PPAV and other established species in this family are now known to have genomes ranging in size from 1,000 to 1,400 kbp.

Two mollicutes (strains F7T [T = type strain] and F28) isolated from floral surfaces of plants growing in Morocco and France were capable of sustained growth in serum-free (or cholesterol-free) mycoplasma broth media. The two isolates were found to be genomically and serologically related. Morphologic examination of the organisms by electron and dark-field microscopic techniques showed that each strain consists of small, nonhelical, nonmotile, pleomorphic coccoid cells surrounded by a single cytoplasmic membrane. No evidence of cell walls was observed. Growth in serum-free or cholesterol-free medium was sustained only when the medium contained a Tween 80 fatty acid mixture (0.01 or 0.04%). The organisms grew rapidly in most conventional mycoplasma culture medium formulations containing horse or fetal bovine serum or a bovine serum fraction and under either aerobic or anaerobic environments. The optimum temperature for growth was 28°C, but multiplication occurred over a temperature range from 20 to 35°C. Both strains catabolized glucose and mannose, but did not hydrolyze arbutin, arginine, or urea. The molecular mass of the genome of strain F7T was determined to be about 886 megadaltons, while the base composition (guanine-plus-cytosine content) of the DNA was found to be 30.0 mol%. The two isolates were serologically unrelated to type strains of the 11 previously described Acholeplasma species and to 10 other unclassified sterol-nonrequiring mollicutes cultivated from various animal, plant, or insect sources. Strain F7 (= ATCC 49495) is the type strain of Acholeplasma seiffertii sp. nov.

Strain CCHT (T = type strain), a helical procaryote that was isolated from floral surfaces of Calystegia hederacea (Convolvulaceae) in Jiangsu, People's Republic of China, was found to be a sterol-requiring member of the class Mollicutes. 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 37°C. 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, Spiroplasma chinense.

Strain 831-C4T (T = type strain), isolated from the surface of lettuce plants (Lactuca sativa) obtained from a retail food market, was shown to be a sterol-requiring mollicute. Morphological examination of this organism by electron and dark-field microscopic techniques showed that it consists of small, nonhelical, nonmotile, pleomorphic coccoid cells, with individual cells surrounded by a single cytoplasmic membrane. No evidence of a cell wall was observed. The organism grew rapidly in all conventional culture medium formulations for mollicutes in either aerobic or anaerobic environments. The optimum temperature for growth was 30 degrees C, but multiplication occurred at 18 to 37 degrees C. Strain 831-C4T catabolized glucose, but hydrolysis of arginine or urea could not be demonstrated. The genome size of strain 831-C4T was determined to be about 569 megadaltons, while the base composition (guanine-plus-cytosine content) of the DNA was 30.0 mol%. Recent studies in which we compared the 16S rRNA sequences of strain 831-C4T with those of more than 40 other mollicutes indicated that this organism is phylogenetically related to the Spiroplasma-Mycoplasma mycoides clade. Strain 831-C4T was serologically unrelated to the type strains of previously described Mycoplasma species and to 18 other unclassified sterol-requiring isolates cultivated from various animal, plant, or insect sources. Strain 831-C4T (= ATCC 49193) is the type strain of Mycoplasma lactucae sp. nov.

Spiroplasma strain DU-1T (T = type strain), which was isolated from hemolymph of the corn rootworm Diabrotica undecimpunctata (Coleoptera:Chrysomelidae), was serologically distinct from other spiroplasma species, groups, and subgroups. Cells of strain DU-1T were shown by light microscopy to be helical motile filaments. Electron microscopy revealed cells bounded by a single cytoplasmic membrane, with no evidence of a cell wall. The organism was not sensitive to 500 U of penicillin per ml. Strain DU-1T grew well in SM-1, M1D, and SP-4 liquid media, in broth supplemented with 1% bovine serum fraction or conventional horse serum, and under both aerobic and anaerobic conditions. This organism did not appear to have a sterol requirement for growth, as has been reported for several other Spiroplasma species or strains. Optimal growth occurred at 32 degrees C, with a doubling time of 0.9 h; strain DU-1T multiplied at 10 to 41 degrees C but failed to grow at 5 or 43 degrees C. It produced acid from glucose but hydrolyzed neither arginine nor urea. The results of reciprocal serologic tests in which antigens or antisera to established Spiroplasma species, groups, subgroups, and putative groups were used indicated that strain DU-1T was serologically distinct. This organism has a DNA guanine-plus-cytosine content of 25 +/- 1 mol% and a genome size of 1,350 kbp. Strain DU-1T is a member of a cluster of fast-growing insect-associated spiroplasmas, as determined by sequence analysis of 16S rRNA. On the basis of the results of this study and previously published data, strain DU-1 (= ATCC 43210) is designated the type strain of a new species, Spiroplasma diabroticae.

Mycoplasma sp. strain G145T (T = type strain) was isolated from a goat's abscessed ankle. Strain G145T required cholesterol or serum for growth and possessed characteristics similar to those of other members of the genus Mycoplasma. This strain was serologically distinct from previously described Mycoplasma. species and from a group of currently unnamed strains thought to belong to the genus Mycoplasma. Strain G145T hydrolyzed arginine, but did not hydrolyze urea or ferment glucose. The guanine-plus-cytosine content of the DNA was 29.6 mol%. We propose that strain G145 (= ATCC 27948) is the type strain of a new species, for which we propose the name Mycoplasma adleri.

Spiroplasma strain EC-1T (T = type strain), which was isolated from the gut of a lampyrid beetle (Ellychnia corrusca) in Maryland, was serologically distinct from other spiroplasma species and groups. Similar strains were obtained from other E. corrusca specimens, and, later, numerous isolates of similar or partially related strains were obtained from several species of tabanid files. Cells of strain EC-1T were helical, motile filaments that were bound by a single cytoplasmic membrane, and there was no evidence of a cell wall. The cells were filterable through 220-nm-pore-size membrane filters but not through 100-nm-pore-size membrane filters. The organism was absolutely resistant to penicillin (1,000 U/ml) and required sterol for growth. Strain EC-1T grew well in M1D and SP-4 liquid media and could be cultivated in the Edward formulation of conventional mycoplasma medium and in 1% serum fraction medium. Optimal growth occurred at 32 degrees C (doubling time, 1.5 h). Strain EC-1T multiplied at 10 to 41 degrees C, but not at 5 or 43 degrees C. This organism produced acid from glucose, but did not hydrolyze arginine or utilize urea. The guanine-plus-cytosine content of the DNA was determined to be 26.3 mol% by the melting temperature method and 27.0 mol% by the buoyant density method. As a result of our studies, strain EC-1 (= ATCC 43212) is designated the type strain of a new species, Spiroplasma corruscae.

Spiroplasma strain MQ-4T (T = type strain), which was isolated from the hemolymph of the vespid wasp Monobia quadridens, was serologically distinct from other spiroplasma species, groups, putative groups, and subgroups. Each strain MQ-4T cell was helical and motile and was surrounded by a single cytoplasmic membrane; there was no evidence of a cell wall. The strain grew well in 1% serum fraction medium, as well as in SM-1, M1D, and SP-4 liquid media, under both aerobic and anaerobic conditions. Strain MQ-4T grew at temperatures ranging from 10 to 41 degrees C but did not grow at 43 degrees C. The strain grew optimally at 37 degrees C with a doubling time of 0.6 h, the shortest doubling time recorded for any spiroplasma. Strain MQ-4T catabolized glucose and arginine but did not hydrolyze urea. The guanine-plus-cytosine content of the DNA was about 27.5 +/- 1 mol%. The genome size was 1,480 kbp (940 MDa). Strain MQ-4 (= ATCC 35262) is designated the type strain of a new species, Spiroplasma velocicrescens.

Eight strains of mollicutes were isolated from pooled suspensions prepared from western black-legged ticks (Ixodes pacificus) 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 degrees C, but multiplication occurred at temperatures ranging from 23 to 32 degrees 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 +/- 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 Spiroplasma. Strain Y32 (= ATCC 33835) is the type strain of Spiroplasma ixodetis sp. nov.

Twenty mollicute strains isolated primarily from insect hosts were characterized and arranged into eight new species in the genus Mesoplasma. Morphological examination of the organisms by electron and dark-field microscopic techniques revealed that the cells of each strain were small, nonhelical, nonmotile, pleomorphic, and coccoid and that each cell was surrounded by a single cytoplasmic membrane with no evidence of a cell wall. Although the new mollicutes grew well in media containing horse or fetal bovine serum, growth in serum-free or cholesterol-free medium occurred only when the medium contained 0.04% polyoxyethylene sorbitan (Tween 80). The optimum temperature for growth was usually 30 degrees C, but multiplication generally occurred over a temperature range of 10 to 32 degrees C. All strains catabolized glucose. Most strains did not hydrolyze arginine or urea, although three related strains isolated from fireflies (the strain PUPA-2T [T = type strain] group) did hydrolyze arginine. The genome sizes ranged from 825 to 930 kbp, and the DNA base compositions (guanine-plus-cytosine contents) ranged from 26.5 to 31.6 mol%. The proposed type strains of the eight new species were not serologically related to the type strains of four other Mesoplasma species, five Entomoplasma species, 11 Acholeplasma species, and 100 Mycoplasma species and subspecies. Strain PS-1 (= ATCC 49582) is the type strain of Mesoplasma pleciae sp. nov., strain PUPA-2 (= ATCC 49581) is the type strain of Mesoplasma photuris sp. nov., strain YJS (= ATCC 51578) [corrected] is the type strain of Mesoplasma syrphidae sp. nov., strain CHPA-2 (= ATCC 49578) is the type strain of Mesoplasma chauliocola sp. nov., strain ELCA-2 (= ATCC 49579) is the type strain of Mesoplasma corruscae sp. nov., strain GRUA-1 (= ATCC 49580) is the type strain of Mesoplasma grammopterae sp. nov., strain BARC 779 (= ATCC 49583) is the type strain of Mesoplasma coleopterae sp. nov., and strain BARC 857 (= ATCC 49584) is the type strain of Mesoplasma tabanidae sp. nov.

Three mycoplasma strains, designated GIHT (T = type strain), UIAT, and VISTT, were isolated from the external ear canals of goats and were shown to be serologically distinct from each other and from previously described Acholeplasma, Entomoplasma, Mesoplasma, and Mycoplasma species. Using light and transmission electron microscopy, we showed that the cells of these organisms were small, pleomorphic, coccoid, nonmotile, and nonhelical and that each cell was surrounded by a single cytoplasmic membrane. There was no evidence of a cell wall, and the organisms grew freely in media containing penicillin at concentrations of 1,000 U/ml or more and thallous acetate (final concentration, 1:4,000) and produced the “fried-egg” morphology typical of most mollicutes. Growth occurred both aerobically and anaerobically (as determined by the GasPak method). The ability to catabolize glucose and mannose and the ability to hydrolyze arginine varied among the three strains. All three strains required sterol for growth, and none of the strains hydrolyzed urea. The guanine-plus-cytosine contents of the DNAs of strains UIAT, VIST, and GIHT were determined to be 26.9, 27.0, and 26.6 mol%, respectively. Our data indicate that the three strains represent new Mycoplasma species, for which we propose the names Mycoplasma auris, Mycoplasma cottewii, and Mycoplasma yeatsii. The type strain of M. auris is UIA (= ATCC 51348 = NCTC 11731), the type strain of M. cottewii is VIS (= ATCC 51347 = NCTC 11732), and the type strain of M. yeatsii is GIH (= ATCC 51346 = NCTC 11730).

A test is described that is useful for characterizing mollicutes in terms of the ability to maintain growth in medium containing 15 to 20% fetal bovine serum or in serum-free media with or without 0.04% Tween 80 (polyoxyethylene sorbitan). Representative Acholeplasma species maintained growth in serum-free medium, and about half of the strains tested grew well in Tween 80-supplemented medium. Representative Mycoplasma and Entomoplasma species did not maintain growth in either serum-free medium alone or when Tween 80 was added. Spiroplasma species and group representatives generally failed to sustain growth in serum-free medium with or without Tween 80, but at least four of the spiroplasmas tested maintained growth in serum-free medium. The representative Mesoplasma species grew in serum-free media only when Tween 80 was added, as did Mycoplasma lactucae. Although the test has obvious determinative uses for members of the class Mollicutes, it does not supplant the conventional methodology for assaying the cholesterol requirements of these organisms.

A 64-year-old slaughterhouse worker with advanced non-Hodgkin's lymphoma developed septicemia and pneumonia. Mycoplasma arginini, a wall-free prokaryote found in a variety of domestic animal hosts, was repeatedly isolated from blood and bronchial washings from the patient. Immunosuppression, in part caused by hypogammaglobulinemia, probably played a key role in predisposing the patient to a fatal infection. This case suggests that animal mycoplasmas should be considered in the list of infectious agents acquired by immunosuppressed hosts.

An unusual mycoplasma, which was isolated from the urine of a human immunodeficiency virus-positive male homosexual patient, has an elongated flask shape and two unique sharply divided internal compartments. The tiplike compartment is densely packed with fine granules, and the body compartment is loosely filled with coarse granules consistent with ribosomal structures. The organism has properties of adherence, hemadsorption, and cytadsorption and invades many different types of mammalian cells. Adhesion and penetration apparently involve the terminally located tiplike structure. Cholesterol is required for growth, and the mycoplasma ferments glucose and hydrolyzes arginine, but does not hydrolyze urea. The results of DNA homology studies revealed that this organism is not genetically related to previously described mycoplasma species that have the same biochemical properties. The results of serologic studies demonstrated that this organism is antigenically distinct from all previously described mycoplasmas. We propose that this new mollicute species should be named Mycoplasma penetrans sp. nov. The type strain is strain GTU-54-6A1 (= ATCC 55252).

Three sterol-requiring mollicutes from floral surfaces of two tropical plant species (Melaleuca quinquenervia and Melaleuca decora) and a single isolate from a flower of the silk oak (Grevillea robusta) were serologically indistinguishable. Strain M1T (T = type strain), isolated from Melaleuca quinquenervia, was chosen for characterization. Light and electron microscopic observations of strain M1T revealed nonhelical, nonmotile, pleomorphic coccoid cells surrounded by a single cytoplasmic membrane. No evidence of a cell wall was observed. The organism grew well in SP-4 medium, but no sustained growth occurred in conventional mycoplasma media containing horse serum. The optimum temperature for growth was 23 degrees C, but multiplication occurred over a temperature range of 10 to 30 degrees C. Growth was not observed at temperatures above 30 degrees C. Strain M1T and related strains (strains M5, M10, and SO1) catabolized glucose but hydrolyzed neither arginine nor urea. The size of the strain M1T genome was about 561 megadaltons, while the guanine-plus-cytosine content of the DNA was about 27.0 mol%. The organism was serologically unrelated to the type strains of the 80 previously recognized Mycoplasma species or to 18 other unclassified sterol-requiring strains cultivated from animal, plant, or insect sources. Recent sequencing studies of 16S rRNA demonstrated that strain M1T is a member of a clade that contains the type species of the genus Mycoplasma. Strain M1 (= ATCC 49191) is the type strain of Mycoplasma melaleucae sp. nov.

Strain PYAN-1T (T = type strain), which was isolated from a pupal gut of the firefly beetle Pyractonema angulata, and strains PIMN-1T and PIPN-2T, which were isolated from guts of adult Photinus marginalis and Photinus pyralis fireflies, respectively, were demonstrated to be sterol-requiring mollicutes. Cells of the three strains were shown by electron and dark-field microscopy to be small, pleomorphic, nonhelical, nonmotile bodies surrounded by single membranes. No evidence of a cell wall was observed, and the organisms were not susceptible to 500 U of penicillin per ml. The three strains grew rapidly in SP-4 broth medium. Strains PIMN-1T and PIPN-2T grew in medium supplemented with bovine serum fraction, but strain PYAN-1T did not. All three strains grew on solid media when the cultures were incubated aerobically, but only strains PYAN-1T and PIPN-2T formed colonies when anaerobic conditions were employed. The three strains catabolized glucose but hydrolyzed neither arginine nor urea. All of the strains grew at temperatures of 18 to 32°C; strains PYAN-1T and PIMN-1T also grew at 10°C. The optimal temperature for growth for strains PYAN-1T and PIPN-2T was 30°C; strain PIMN-1T grew equally well at 30 or 32°C. None of the three strains grew at 37°C. The genome sizes of strains PYAN-1T, PIMN-1T, and PIPN-2T were about 527 (478 to 589), 570 (480 to 630), and 762 (635 to 871) megadaltons, respectively. The guanine-plus-cytosine contents of the DNAs of the strains, as determined by buoyant density, thermal denaturation, and high-performance liquid chromatography methods, were as follows: 27.4, 30.2, and 27.5 mol%, respectively, for strain PYAN-1T; 28.8, 31.2, and 29.2 mol%, respectively, for strain PIMN-1T; and 28.4, 30.4, and 31.2 mol%, respectively, for strain PIPN-2T. All three strains were serologically unrelated to the type strains of previously established Mycoplasma species (including Mycoplasma ellychniae), to each other, and to 15 other unclassified sterol-requiring strains isolated from animals, plants, and insects. Along with M. ellychniae, these three organisms represent an unusual cluster of strains belonging to the genus Mycoplasma isolated from insects. Strain PYAN-1 (= ATCC 49194) is the type strain of Mycoplasma somnilux sp. nov.; strain PIMN-1 (= ATCC 49195) is the type strain of Mycoplasma luminosum sp. nov.; and strain PIPN-2 (= ATCC 49196) is the type strain of Mycoplasma lucivorax sp. nov.

Three acholeplasmas isolated from floral surfaces of healthy plants in Florida were found to be similar in their biochemical and serological properties. These organisms did not require serum or cholesterol for growth, although addition of some supplementary fatty acids (as represented by Tween 80) was necessary for growth to occur in serum-free medium. The three strains possessed biochemical properties typical of the Acholeplasmataceae and were distinguished from the nine previously recognized Acholeplasma species by serological and deoxyribonucleic acid-deoxyribonucleic acid hybridization techniques. The genome molecular weight of the three Acholeplasma strains was 109, and the guanine-plus-cytosine content of the deoxyribonucleic acid was 27 to 28 mol%. On the basis of these results and other morphological, biological, and serological properties, we propose that these organisms represent a new species, Acholeplasma florum. Strain L1 (= ATCC 33453) is the type strain.

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 I-1 to I-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 XII to XXIII.

Two acholeplasmas recovered from contaminated cell cultures or commercial fetal bovine serum were found to be similar in biochemical and serological properties. The organisms, although not requiring serum or cholesterol for growth, did require a supplement of 0.5% albumin and 10 μg of palmitic acid per ml to a serum-free medium for sustained growth in the absence of sterols. The growth of both organisms was inhibited in medium containing 20% horse serum, although smaller amounts of horse serum or 20% fetal bovine serum did not exert inhibitory effects. The two strains possessed biochemical properties typical of other non-sterol-requiring members of the Mycoplasmatales, and they were serologically distinct from seven established Acholeplasma species. On the basis of these findings and other morphological, biological, and serological properties of the organisms, it is proposed that these organisms represent a new species, Acholeplasma morum. Strain 72–043 (=ATCC 33211) is the type strain.

Seven arginine-utilizing mycoplasmas isolated from upper respiratory tracts of normal swine were shown to be serologically distinct from other arginine-utilizing species previously isolated from swine. The isolates required sterol for growth but did not utilize glucose or urea. The isolates were distinct from over 80 additional mycoplasmas, as determined by epiimmunofluorescence and growth inhibition tests. Based on morphological, biological, and serological properties, we propose that these strains constitute a new mycoplasma species, Mycoplasma hyopharyngis. Strain H3-6B F (ATCC 35707) has been designated as the type strain.

Three spiroplasma strains recovered from rabbit ticks (Haemaphysalis leporispalustris) in Georgia and Maryland were found to be similar in biochemical, serological, and pathological properties. The organisms grew at temperatures of 20 to 37°C, required cholesterol for growth, fermented glucose, hydrolyzed arginine, and produced a film and spot reaction. The three spiroplasma strains were serologically distinct from the one established species (Spiroplasma citri) in the genus and from all other unclassified spiroplasma serogroups presently known. On the basis of these findings and other morphological, biological, and serological properties of the organism, it is proposed that spiroplasma strains with these characteristics be classified as a new species, Spiroplasma mirum. Strain SMCA (ATCC 29335) is the type strain.

Eighteen male and eight female primates, representing five subhuman species, were inoculated urogenitally with Mycoplasma genitalium, a microorganism recovered from men with nongonococcal urethritis. Male rhesus (Macaca mulatta) and cynomolgus (Macaca fascicularis) monkeys apparently were resistant. Female squirrel monkeys (Saimiri sciureus) and female tamarins (Saguinus mystax) exhibited low-level, genital-tract infections. Male chimpanzees (Pan troglodytes) developed an obvious genital-tract infection, with some shedding organisms for 21 weeks. M. genitalium was recovered from the blood of two of the male chimpanzees, usually when large numbers of organisms were in the urethra. Female chimpanzees generally shed organisms for 12-15 weeks. Most chimpanzees colonized with the organism exhibited increased numbers of polymorphonuclear leukocytes in the genital tract and developed a significant antibody response. The results offer substantial evidence for the pathogenicity of M. genitalium for the urogenital tract of higher primates and suggest the microorganism may have a role in human genital-tract infections.

The isolation of Mollicutes from food has not been reported. To isolate Mollicutes in the presence of high levels of unwanted bacteria, we first incubated fresh vegetables in liquid culture media containing lysozyme, ampicillin, and thallous acetate. Culture fluids were than separated from the vegetable samples, subjected to one freeze-thaw cycle, and passed through a filter of 0.4-micron porosity. Filtered samples were cultured in SP4 medium and in a conventional medium containing horse serum. With this procedure 21 acholeplasma isolations representing three species were obtained from endive, broccoli, and kale. Of 35 food samples tested, 11 were positive for acholeplasmas; acholeplasmas isolated from 6 of these samples were recovered only in SP4 medium. In seven single vegetable samples, two or more Acholeplasma spp. were isolated. A. laidlawii was isolated from all three vegetables and A. axanthum was found in broccoli and kale. Four isolates were serologically identified as A. oculi. Mycoplasma verecundum was the only Mycoplasma species recovered. Several isolates could not be typed serologically, as they reacted with antisera to both A. morum and A. hippikon. these isolates may include new Acholeplasma spp.

Wall-less prokaryotes from guts of five insect species (a corn root maggot [Plecia sp.: Diptera: Bibionidae, strain PS-1], a syrphid fly [Diptera: Syrphidae, strain YJS], two tabanid flies [Tabanus catenatus, strain TAC, andChrysops discalis, strain DF-2], and a vespid wasp [Monobia quadridens, strain MQ-3]) were characterized. The strains grew at 23°–32°C in conventional mycoplasma media containing 10% (vol/vol) serum, or in serum-free mycoplasma medium with or without fatty-acid-Tween-80 supplements. No helical forms were noted in dark-field microscopy, and electron micrographs of thin sections of the strains showed a single membrane. Two strains (DF and MQ-3) cross reacted with antiserum againstAcholeplasma florum. Although the other three strains did not react with antisera to establishedAcholeplasma orMycoplasma species, they were otherwise characteristic of acholeplasmas. This study, the first to demonstrate acholeplasmas from Arthropoda, in conjunction with previous isolations from plant surfaces, suggests that insects may constitute an important reservoir for acholeplasmas.

Twenty-eight strains of spiroplasma subgroup I-2 isolated from insects and flower surfaces were similar in their serological properties. Strain BC-3T (T = type strain), which was isolated from the honeybee, was chosen as a representative of this cluster and was characterized according to accepted standards. This strain and other strains of the cluster entered the hemocoel of their insect hosts after per os acquisition, caused pathology in various tissues, and reduced adult longevity. Growth in SM-1 or M1D medium occurred at 20 to 37°, with optimum growth at about 32 to 35°. Cholesterol was required for growth. Glucose, fructose, and other carbohydrates were fermented, and arginine was catabolized. Seventeen strains, including strain BC-3T, reacted with considerable homogeneity in deformation tests and were completely separable from strains of subgroup I-1 (Spiroplasma citri) and subgroup I-3 (corn stunt spiroplasma). A group of five subgroup I-2 strains showed homogeneity upon one-dimensional polyacrylamide gel electrophoresis of cell proteins. Strain BC-3T was also serologically distinct from subgroups I-4 through I-8; from Spiroplasma floricola, Spiroplasma apis, and Spiroplasma mirum; and from representative strains of spiroplasma groups II and VI through XI. Previously published studies on strain BC-3T and related strains demonstrated that (i) these organisms comprise a unique subgroup of the S. citri complex (group I); (ii) deoxyribonucleic acid-deoxyribonucleic acid homologies between strain BC-3T and strains of other group I subgroups do not exceed 70%; (iii) the patterns of protein sharing among group I strains revealed by two-dimensional polyacrylamide gel electrophoresis support molecular genetic indications of partial relatedness; (iv) the EcoRI restriction endonuclease patterns of deoxyribonucleic acids from strain BC-3T and serologically related strains show close relatedness; (v) sequencing of 5S ribosomal ribonucleic acid suggests some degree of relatedness with all organisms now classified in the Mollicutes; (vi) strain BC-3T is capable of viscotactic and chemotactic responses; (vii) strain BC-3T possesses fibrils that may mediate various types of motility; and (viii) a lytic virus (SpV4) isolated from Spiroplasma sp. strain B63 (a representative of subgroup I-2) is morphologically and genomically distinct from other spiroplasma viruses and forms plaques only on lawns of subgroup I-2 spiroplasmas. Previous work on strain AS 576, another member of subgroup I-2, demonstrated (i) a viscotactic response, (ii) moderate sensitivity to osmotic environments, (iii) susceptibility to tetracycline and aminoglycoside antibiotics, (iv) growth in a relatively simple, chemically defined medium, (v) nutritional utilization patterns in defined medium, and (vi) a genome molecular weight of 109. On the basis of our new findings and the previously described properties of strain BC-3T and related subgroup I-2 strains, we propose that spiroplasma strains with the characteristics described here be classified as a new species, Spiroplasma melliferum. Strain BC-3, the type strain, has been deposited in the American Type Culture Collection as strain ATCC 33219.

Two mycoplasmas recovered from human urogenital tracts were similar in their biochemical and serological properties. These organisms possessed a unique terminal structure that appeared to be associated with attachment to tissue cells and erythrocytes. The organisms fermented glucose but did not hydrolyze urea or arginine. Growth occurred at 30 to 37°. Cholesterol was required for growth. Unlike most other mycoplasmas, both strains were susceptible to thallium acetate. These two organisms were serologically distinct from other Mycoplasma species and from a group of unclassified serotypes of mycoplasmas. On the basis of these findings and other morphological, biological, and serological properties of the microorganisms, we propose that mycoplasmas with these characteristics belong to a new species, Mycoplasma genitalium. Strain G-37 (= ATCC 33530) is the type strain.

The present study compared the genetic characteristics of three previously unclassified acholeplasmas of plant origin with those of the eight established species ofAcholeplasma. A radiolabeled DNA probe was derived from the lemon (L1) strain acholeplasma by using the nick translation method and hybridized to the excess unlabeled DNA isolated from the eight established species ofAcholeplasma and three new isolates from plants. Nucleic acid hydridization and serological tests confirmed that the L1 acholeplasma was distinct from all eight established species ofAcholeplasma but closely related to strains isolated from the flowers of grapefruit trees (GF1) and powder puff plants (PP2). The results suggest that these new acholeplasmas isolated exclusively from plants may represent a new species ofAcholeplasma.