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At least 19 recordsLinked to original sources

Phosphofructokinase activities within the order spirochaetales and the characterisation of the pyrophosphate-dependent phosphofructokinase from spirochaeta thermophila

The subtype of phosphofructokinase activity, either ATP-, ADP- or pyrophosphate-dependent, present in members of three genera from the Spirochaetales was investigated. The individual species/strains examined included Spirochaeta alkalica, S. asiatica, S. halophila, S. isovalerica, S. litoralis, S. zuelzerae, S. thermophila, two thermophilic spirochetes, Treponema bryantii, T. denticola, paragraph signT. pectinovorum, Leptospira biflexa and L. interrogans. All of the Spirochaeta strains, regardless of their phenotype, possessed primarily a pyrophosphate-dependent phosphofructokinase. In contrast, T. bryantii, T. denticola and L. biflexa had predominantly an ATP-dependent activity, whereas no activity was detected in T. pectinovorum or paragraph signL. interrogans. The results suggest that pyrophosphate-dependent phosphofructokinase activity may be a reliable phenotypic marker for the genus Spirochaeta and that there are potentially interesting differences in how the catabolism of saccharides is controlled among members of genera within the Spirochaetales. The pyrophosphate-dependent phosphofructokinase from S. thermophila strain RI 19.B1 was purified (303-fold) to homogeneity and biochemically characterised. The S. thermophila enzyme displayed hyperbolic kinetics with respect to both the forward and reverse cosubstrates and was not significantly affected by traditional activators or inhibitors of phosphofructokinase. The biochemical characterisation represents the first spirochete phosphofructokinase to be described.

Journal Article↗

Sylvatic maintenance of Borrelia burgdorferi (Spirochaetales) in Northern California: untangling the web of transmission.

Lyme borreliosis is associated with several genospecies of Borrelia burgdorferi sensu lato (s.l.) (Spirochaetales), but human disease has been associated only with Borrelia burgdorferi sensu stricto (s.s.) Johnson, Schmid, Hyde, Steigerwalt & Brenner in the western United States. Restriction fragment length polymorphism (RFLP) analysis of rrf-rrl amplicons from 124 tick and mammalian isolates from various habitats yielded 13 RFLP patterns. Of these patterns, six were patterns previously associated either with Borrelia bissettii Postic, Marti Ras, Lane, Hendson & Baranton or Borrelia burgdorferi s.s., and the remaining seven patterns belonged to diverse and previously uncharacterized Borrelia spp. Uncharacterized Borrelia spp. were cultured most frequently from Ixodes spinipalpis Hadwen & Nuttall and California kangaroo rats, Dipodomys californicus Merriam, inhabiting grasslands, and B. bissettii from I. spinipalpis and dusky-footed woodrats, Neotoma fuscipes Baird, associated with oak woodlands or chaparral. B. burgdorferi s.s. typically was isolated from host-seeking Ixodes pacificus Cooley & Kohls collected in dense oak woodlands, woodland-grass, or redwood forests. Although some isolates of B. burgdorferi s.s. were cultured from woodrats, there was no clear association of this human pathogen with any vertebrate host. These findings, along with recent evidence indicating that the western gray squirrel, Sciurus griseus Ord, may be an important reservoir of B. burgdorferi s.s. in Californian oak woodlands, suggest that our earlier hypothesis implicating an enzootic cycle involving woodrats and I. spinipalpis is insufficient to account for observed patterns of infection in nature.

Animals↗

Ticks (Acari: Ixodidae) and spirochetes (spirochaetaceae: spirochaetales) recovered from birds on a Georgia Barrier Island.

From September 1997 through July 1999, 300 individuals and 46 species of birds were mist-netted and screened for ticks and spirochetes on St. Catherine's Island, Liberty County, GA. Seventy-six (25%) of the birds were parasitized by a meal intensity of 4.6 ticks. Seasonally, more birds were infested with ticks during the summer (50% in 1998, 34% in 1999) than in spring (15% in 1998, 11% in 1999) or fall (21% in 1997, 20% in 1998), mainly because of severe infestations on some birds by immature stages of the lone star tick, Amblyomma americanum (L.), during this season. Eight species ofticks were recovered from 14 species of birds during this study: A. americanum (74 nymphs, 168 larvae); the blacklegged tick, Ixodes scapularis Say (11 nymphs, 28 larvae), the Gulf Coast tick, Amblyomma maculatum Koch (two nymphs, 29 larvae); Ixodes minor Neumann (16 larvae); the rabbit tick. Haemaphysalis leporispalustris (Packard) (one nymph, 14 larvae); the bird tick Ixodes brunneus Koch (two larvae); the American dog tick, Dermacentor variabilis (Say) (one nymph); and Ixodes affinis Neumann (one larva). The Carolina wren was parasitized by more species of ticks (seven) than any other bird species, followed by the northern cardinal (five), white-throated sparrow (four) and painted bunting (three). Spirochetes were isolated in BSK II medium from one tick (a nymphal A. americanum) and from skin biopsies of 12 (4%) of the individual birds (three downy woodpeckers, three northern waterthrushes, two Carolina wrens, one American redstart, one pine warbler, one Swainson's thrush, and one white-eyed vireo) all in fall 1997. This concentrated phenology of spirochete isolations might reflect periodic amplification or recrudescence of spirochetes in reservoir avian hosts.

Animals↗

Isolation of Borrelia burgdorferi (Spirochaetales: Spirochaetaceae) from Ixodes scapularis and Dermacentor albipictus ticks (Acari: Ixodidae) in Oklahoma.

Borrelia burgdorferi was isolated from Ixodes scapularis Say and Dermacentor albipictus Packard that were removed as partially fed adults from white-tailed deer, Odocoileus virginianus Zimmermann, in Oklahoma. Isolation in media was accomplished only after homogenates of pooled field-collected ticks were inoculated into laboratory-reared Peromyscus leucopus and reisolated from the urinary bladder into BSK II media. Both isolates were confirmed by western blot analysis and reactivity with monoclonal antibody H5332. These are the first reported isolates of B. burgdorferi from Oklahoma from these two tick species and are the first isolates from ticks from the south-central United States that were infective for laboratory-reared P. leucopus.

Animals↗

Attempted transmission of Borrelia burgdorferi (Spirochaetales: Spirochaetaceae) (JDI strain) by Ixodes scapularis (Acari: Ixodidae), Dermacentor variabilis, and Amblyomma americanum.

Laboratory-reared Ixodes scapularis Say, Amblyomma americanum (L.), and Dermacentor variabilis (Say) were fed on New Zealand white rabbits experimentally infected with Borrelia burgdorferi (JDI strain). At repletion, spirochetes could be detected by dark-field microscopy only in I. scapularis. Acquisition rates were 18 and 21%. When previously exposed nymphs of each species were fed on susceptible rabbits, I. scapularis was the only tick of the three species that transmitted B. burgdorferi. When a single rabbit was experimentally infected with B. burgdorferi and infested at 7-d intervals with I. scapularis, A. americanum, D. variabilis, and a second time with I. scapularis, B. burgdorferi was detected again only in cultures from the two groups of I. scapularis. When molted nymphs from each tick species were allowed to feed on susceptible rabbits, spirochetes again were isolated only at necropsy from the rabbits on which the two groups of I. scapularis fed.

Animals↗

Adhesion to and invasion of cultured tick (Acarina: Ixodidae) cells by Borrelia burgdorferi (Spirochaetales: Spirochaetaceae) and maintenance of infectivity.

Lyme disease spirochetes, Borrelia burgdorferi, interact with cultured tick cells in ways similar to those reported to occur in the vector Ixodes dammini Spielman, Clifford, Piesman & Corwin. Spirochete adhesion and penetration were examined using a cell line from embryos of Rhipicephalus appendiculatus Neumann that morphologically resembles tick gut cells, RAE25. Cocultivation of B. burgdorferi with these cells permitted prolonged maintenance of infectivity for hamsters. Borrelial adherence to RAE25 cells was time- and density-dependent and increased by 10-15% per h during the first 5.5 h of cocultivation when we used a concentration of 4 x 10(7) spirochetes/ml. After 6 h, > 90% of the cells bound an average of 3-5 spirochetes per cell. Low passage, hamster-infective strains of B. burgdorferi (JMNT and CD16) showed a 2-3-fold higher rate of adhesion to RAE25 cells than the highly passaged, noninfectious strain B31. Inactivation of CD16 or JMNT by heat, starvation, or treatment with puromycin reduced adherence by 40-60%, whereas pretreatment with monoclonal antibodies to the outer surface proteins had no effect. Spirochetes adhered to young I. dammini cell lines to a similar degree as they did to RAE25, whereas lines from the ticks Dermacentor variabilis (Say) (RML15) and Boophilus microplus (Canestrini) (BME26) bound 30-60% fewer spirochetes. Electron microscopy revealed epicellular borreliae associated with coated pits and vesicles before endocytosis, and intracellular spirochetes were surrounded by a host cell-derived membrane.

Animals↗

Presence of Borrelia burgdorferi (Spirochaetales: Spirochaetaceae) in southern Kettle Moraine State Forest, Wisconsin, and characterization of strain W97F51.

Lyme disease, caused by Borrelia burgdorferi Johnson, Schmidt, Hyde, Steigerwalt & Brenner; babesiosis, caused by Babesia microti Franca; and human granulocytic ehrlichiosis, caused by Anaplasma phagocytophilum Bakken & Dumler have been reported in Wisconsin, mainly in the endemic areas of the northwestern part of the state. People exposed to blacklegged ticks, Ixodes scapularis Say, from this region can potentially contract one or all of these diseases concurrently. Within the past several years, there have been cases of Lyme disease reported from southeastern Wisconsin, an area that contains deer, mice, and similar vegetation found at regions with high endemicity. However, past white-tailed deer surveys suggested no existence of I. scapularis in southeastern Wisconsin. However, in 1996, we identified questing adult I. scapularis in the southernmost part of the Southern Kettle Moraine State Forest, Walworth County. To determine whether an established population of I. scapularis exists in this region, we performed a detailed survey of the abundance of host-seeking I. scapularis adults and the presence and abundance of subadults feeding on white-footed mice, Peromyscus leucopus Rafinesque. We also tested for possible infections of B. burgdorferi, Ba. microti, and A. phagocytophilum in ticks and B. burgdorferi harbored by mice. In 1997 and 1998, a total of 249 P. leucopus mice and 118 questing adult I. scapularis ticks, in addition to 157 larvae and seven nymphs feeding on mice, were collected and their locations were recorded from the Nordic trails of the Southern Kettle Moraine State Forest. Only one P. leucopus and its attached engorged I. scapularis nymph were infected with B. burgdorferi, whereas none of the engorged larvae attached to mice were infected. However, 4.2% of questing adult I. scapularis were infected with B. burgdorferi. The abundance of questing adult I. scapularis was 1.6 ticks per hour. The prevalence of subadult ticks on mice was 27%, with a mean intensity on infested mice of 2.0. I. scapularis adults were not infected with either Ba. microti or A. phagocytophilum. A unique strain of B. burgdorferi s.l. (W97F51) was discovered, showing 33 nucleotide substitutions and one codon insertion in a 567-bp fragment of the OspB gene, compared with Borrelia bissettii (strain Ca389). The sequences of ospA, ospB, ospC,fla, and rrs genes and the rrf-rrl intergenic spacer region were compared between W97F51 and other B. burgdorferi s.l. species. Although W97F51 was most genetically related to B. bissettii, the genetic identity of W97F51 was less than that of B. bissettii conspecifics. This study documents the existence of an established population of I. scapularis and the presence of B. burgdorferi with a novel strain in southeastern Wisconsin.

Animals↗

Lipids of the Spirochaetales: comparison of the lipids of several members of the genera Spirochaeta, Treponema, and Leptospira.

The lipid compositions of 17 spirochetes belonging to the genera Spirochaeta and Treponema were investigated and compared with data previously derived from 11 strains of Leptospira. The lipid compositions and lipid metabolism of any of these genera is sufficiently different to be characteristic of that genus and to differentiate it from the other two genera. Members of the genus Leptospira are characterized by their ability to beta-oxidize long chain fatty acids as their major carbon and energy source. With few exceptions, they are incapable of synthesizing fatty acids de novo. The major phospholipid found was phosphatidyl ethanolamine. No glycolipid or phosphatidyl choline was found in these organisms. Members of the genus Treponema studied were incapable of beta-oxidation as well as de novo synthesis of fatty acids. Phosphatidyl choline is the major phospholipid of this genus. The glycolipid, monogalactosyl diglyceride, is a major component of the Treponema. Members of the Spirochaeta did synthesize fatty acids de novo. Although these spirochetes contain a monoglycosyl diglyceride, the hexose content of the glycolipid varied from species to species. Neither phosphatidyl ethanolamine nor phosphatidyl choline was found in the Spirochaeta.

Chromatography, Gas↗

The prevalence of Borrelia burgdorfieri (Spirochaetales: spirochaetaceae) and the agent of human granulocytic ehrlichiosis (Rickettsiaceae: Ehrlichieae) in Ixodes scapularis (Acari:Ixodidae) collected during 1998 and 1999 from Minnesota.

We tested 103 adult Ixodes scapularis Say from 12 counties in Minnesota for the presence of Borrelia burgdorferi and the causative agent of human granulocytic ehrlichiosis (HGE), using polymerase chain reaction (PCR). A total of 17 ticks (16.5%) was positive for B. burgdoiferi using nested PCR for the flagellin gene. or both PCR for the ospA gene and nested PCR for the flagellin gene. A total of four ticks (3.8%) was positive for the agent of HGE using nested PCR for 16S rDNA. Counties in Minnesota with established and recently reported populations of I. scapularis both had ticks infected with B. burgdorferi. The agent of HGE was only detected in counties with established I. scapularis populations.

Anaplasmataceae↗