Wolbachia Persica Research Articles

Current knowledge of the taxonomy and classification of representatives from the order Legionellales (Legionellaceae, Coxiellaceae) Phylum Pseudomonadota

Since the development of microbiology as a science, the identification, systematics and classification of microorganisms have been carried out based on the study of phenotypic characteristics. In the second half of the 20th century, after the discovery of the structure of DNA and polymerase chain reaction, the era of molecular biological research began in microbiology. Since 2002, the use of a complex of molecular biological and phylogenetic methods has been recommended as a guiding approach in the classification and taxonomy of prokaryotes, which has led to reclassification in some taxa. The representation of the taxonomy of Legionella pneumophila (order Legionellales, class Gammaproteobacteria) was formulated after the outbreak of legionnaires’ disease (legionellosis) in the USA in 1976. The description of the causative agent of Q-fever – Coxiella burnetii occurred 40 years earlier, but its classification and taxonomic status in the order Rickettsiales of the class Alphaproteobacteria were presented incorrectly based on the study of available phenotypic characteristics in the 1930s and 1950s. This determined the «fate» of C. burnetii and Q-fever for half a century, included in the list of rickettsiae and rickettsioses traditionally studied by rickettsiologists. As a result of the application of molecular biological methods in the 1990s, in the order Legionellales was replenished by several representatives of the order Rickettsiales, three representatives of which (C. burnetii, Rickettsiella grilli and Wolbachia persica) were moved to the class Gammaproteobacteria. Analysis of the 16S rRNA gene sequence led to the reclassification of Coxiella into a separate genus of gamma-proteobacteria of the phylum Proteobacteria (now Pseudomonadota) along with the genera Legionella, Francisella and Rickettsiella with representatives of which have the greatest phylogenetic relationship. Sequencing of the 16S rRNA gene of C. burnetii isolates from different geographical regions revealed only three nucleotide substitutions, indicating that the nucleotide sequences of these strains are closely related (the degree of homology is 99%), which confirms the phylogenetic uniformity of the genus Coxiella within a single species. A comparative analysis of the proteome of representatives of the order Legionellales and a phylodendrogramm constructed during the study of the main proteins of representatives of the genera Legionella, Coxiella, Acquicella and Rickettsiella (Diplorickettsia) allowed the formation of various clades confirming their monophyla. The C. burnetii genome encodes 24 similar components out of 27 involved in the pathogenesis of L. pneumophila by type IVB secretory system (type IVB secretory systems). Verification of the taxonomic position of C. burnetii is an example of the use of molecular biological methods to solve problems of taxonomy and classification of prokaryotes. It is advisable to use an integrated approach based on the application of «classical» methods of bacteriology and new molecular biological and phylogenetic methods, which will allow to obtain an objective understanding of the microorganisms associated with the human population.

Reclassification of Wolbachia persica as Francisella persica comb. nov. and emended description of the family Francisellaceae.

The taxonomic status of the bacterium Wolbachia persica is described, and based on the evidence presented, transfer of this species to the genus Francisella as Francisella persica comb. nov. is proposed. This reclassification is supported by data generated from genomic comparisons of W. persica ATCC VR-331T ( = FSC845T = DSM 101678T) to other near neighbours, including Francisella tularensis subsp. novicida. The full-length 16S rRNA gene sequence of strain ATCC VR-331T had 98.5 % nucleotide identity to the cognate gene in F. tularensis, with the highest similarity to subspecies novicida. Phylogenetic trees of full-length 16S rRNA gene, gyrA and recA sequences from species of the genera Wolbachia (class Alphaproteobacteria) and Francisella (class Gammaproteobacteria) indicated that W. persica ATCC VR-331T was most closely related to members of the genus Francisella and not Wolbachia. Local collinear blocks within the chromosome of strain ATCC VR-331T had considerable similarity with F. tularensis subsp. novicida, but not with any Wolbachia strain. The genomes of strain ATCC VR-331T and F. tularensis subsp. novicida Utah 112T ( = ATCC 15482T) contained an average nucleotide identity mean of 88.72 % and median of 89.18 %. Importantly, the genome of strain ATCC VR-331T contained one Francisella Pathogenicity Island, similar to F. tularensis subsp. novicida, as well as the Francisella-specific gene fopA1 and F. tularensis-specific genes fopA2 and lpnA (also referred to as tul4). In contrast to the obligate intracellular genus Wolbachia, strain ATCC VR-331T and facultative intracellular Francisella can replicate in specialized cell-free media. Collectively, these results demonstrate that Wolbachia persica should be reclassified in the genus Francisella as Francisella persica comb. nov. The type strain of Francisella persica comb. nov. is ATCC VR-331T ( = FSC845T = DSM 101678T). An emended description of the family Francisellaceae is also provided.

Genome characterisation of the genus Francisella reveals insight into similar evolutionary paths in pathogens of mammals and fish.

BackgroundPrior to this study, relatively few strains of Francisella had been genome-sequenced. Previously published Francisella genome sequences were largely restricted to the zoonotic agent F. tularensis. Only limited data were available for other members of the Francisella genus, including F. philomiragia, an opportunistic pathogen of humans, F. noatunensis, a serious pathogen of farmed fish, and other less well described endosymbiotic species.ResultsWe determined the phylogenetic relationships of all known Francisella species, including some for which the phylogenetic positions were previously uncertain. The genus Francisella could be divided into two main genetic clades: one included F. tularensis, F. novicida, F. hispaniensis and Wolbachia persica, and another included F. philomiragia and F. noatunensis.Some Francisella species were found to have significant recombination frequencies. However, the fish pathogen F. noatunensis subsp. noatunensis was an exception due to it exhibiting a highly clonal population structure similar to the human pathogen F. tularensis.ConclusionsThe genus Francisella can be divided into two main genetic clades occupying both terrestrial and marine habitats. However, our analyses suggest that the ancestral Francisella species originated in a marine habitat. The observed genome to genome variation in gene content and IS elements of different species supports the view that similar evolutionary paths of host adaptation developed independently in F. tularensis (infecting mammals) and F. noatunensis subsp. noatunensis (infecting fish).

Fangia hongkongensis gen. nov., sp. nov., a novel gammaproteobacterium of the order Thiotrichales isolated from coastal seawater of Hong Kong

A Gram-negative, coccobacillus-shaped, aerobic bacterium, designated strain UST040201-002T, was isolated in February 2004 from seawater at the outlet of a sandfilter in Port Shelter, Hong Kong SAR, China. This strain possessed ubiquinone-8; its 16S rRNA gene sequence shared only 91% similarity with the sequence from Caedibacter taeniospiralis and 89-90% similarity with sequences from Francisella tularensis, Francisella novicida, Francisella philomiragia and Wolbachia persica. 16S rRNA gene sequence analysis showed that the strain formed a distinct clade with C. taeniospiralis. This subcluster formed a tight coherent group with members of the family Francisellaceae and W. persica. Combined phylogenetic and physiological data suggest that strain UST040201-002T represents a novel genus and species within the order Tauhiotrichales. The name Fangia hongkongensis gen. nov., sp. nov. is proposed; the type strain is UST040201-002T (=JCM 14605T=NRRL B-41860T).

Francisella-like Endosymbionts of Ticks

Ticks affect human and animal health both directly by their blood feeding and indirectly by transmission of many disease-causing bacteria, such as Rickettsia, Ehrlichia, Borrelia, Coxiella, Cowdria, Anaplasma, Aegyptionella, and Tularemia, as well as many viruses (Piesman and Gage, 1996). In addition to these infectious agents, ticks harbor bacterial endosymbionts, such as Wolbachia persica, which was first isolated from the soft tick now classified as Argus arboreus (Suitor and Weiss, 1961).

Endosymbionts of ticks and their relationship to Wolbachia spp. and tick-borne pathogens of humans and animals.

The presence, internal distribution, and phylogenetic position of endosymbiotic bacteria from four species of specific-pathogen-free ticks were studied. These included the hard ticks Ixodes scapularis (the black-legged tick), Rhipicephalus sanguineus (the brown dog tick), and Haemaphysalis longicornis and the African soft tick Ornithodoros moubata. PCR assays for bacteria, using two sets of general primers for eubacterial 16S and 23S rRNA genes (rDNAs) and seven sets of specific primers for wolbachial, rickettsial, or Francisella genes, indicated that I. scapularis possessed symbiotic rickettsiae in the ovaries and that the other species harbored eubacteria in both the ovaries and Malpighian tubules. Phylogenetic analysis based on the sequence of 16S rDNA indicated that the symbiont of I. scapularis belonged to the alpha subgroup of proteobacteria and was closely related to the members of the genus Rickettsia. The other species had similar microorganisms in the ovaries and Malpighian tubules, which belonged to the gamma subgroup of proteobacteria, and formed a monophyletic group with the Q-fever pathogen, Coxiella burnetii. O. moubata harbored another symbiont, which formed a monophyletic group with Francisella tularensis and Wolbachia persica, the latter a symbiont previously isolated from Malpighian tubules of the soft tick Argas (Persicargas) arboreus. Thus, the symbionts of these four tick species were not related to the Wolbachia species found in insects. The two symbionts that live in the Malpighian tubules, one closely related to C. burnetii and the other closely related to F. tularensis, appear to be of ancient origin and be widely distributed in ticks.

Wolbachia in a Predator–Prey System: 16S Ribosomal Dna Analysis of Two Phytoseiids (Acari: Phytoseiidae) and Their Prey (Acari: Tetranychidae)

Using specific polymerase chain reaction (PCR) primers, the 5' region of Wolbachia 16S ribosomal DNA from the predatory mite Metaseiulus occidentalis (Nesbitt) and the twospotted spider mite, Tetranychus urticae Koch, was amplified. Because the prey contains Wolbachia , a method to eliminate amplification of transient Wolbachia from the gut contents was necessary. We found that if the otherwise uninfected phytoseiid Amblyseius reductus Wainstein was fed spider mite prey containing Wolbachia , a positive PCR signal was detectable immediately after feeding, but not 4 h later. M. occidentalis remained positive for Wolbachia by the PCR even 48 h after feeding, although a stronger signal was present at 24 h or less. Wolbachia DNA could be amplified from the predator's eggs, suggesting it is transovarially transmitted and a stable symbiont in this predatory mite. All but 1 of the laboratory colonies of M. occidentalis tested were positive for Wolbachia by the PCR, including those from other laboratories. One fresh collection of M. occidentalis and their prey Panonychus ulmi (Koch) were tested immediately and again 5 d after collection from the field, but a positive PCR signal was never detected. A field-collected sample of T. urticae did not test positive for Wolbachia , although a Wolbachia -specific signal was detected in a population of the strawberry spider mite, T. turkestani Ugarov & Nikolski, collected simultaneously from the same field. PCR products from 1 adult female of the Russian Select strain of M. occidentalis , 60 eggs of the COS strain of M. occidentalis , and 1 male T. urticae were directly sequenced. Phylogenetic analyses placed them within the same clade as Wolbachia from insects, clustered together with the type species, Wolbachia pipientis Hertig, from Culex pipiens L. The Wolbachia from these mites was not similar to Wolbachia persica Suiter & Weiss from another acarine, the fowl tick, Argas persicus (Oken). The sequence similarity between the mite and insect Wolbachia provides more evidence for the horizontal transfer of this microorganism between diverse arthropods.

Analysis of 16S Ribosomal DNA Sequences of Francisella Strains and Utilization for Determination of the Phylogeny of the Genus and for Identification of Strains by PCR

The 16S ribosomal DNAs (rDNAs) of two strains of Francisella tularensis and one strain of Francisella philomiragia were sequenced. On the basis of phylogenetic analysis data, the genus Francisella was placed in the gamma subclass of the Proteobacteria. The most closely related organism was the intracellular bacterium Wolbachia persica. The sequenced 16S rDNA molecules of the Francisella species exhibited very high levels of similarity (98.5 to 99.9%). Two variable regions, comprising 390 to 450 nucleotides of the 16S rDNA molecules of 17 additional Francisella strains, including members of the species F. tularensis and F. philomiragia, were also sequenced. At most, six nucleotide differences were observed among the sequences of the F. tularensis strains. The sequence of Francisella novicida was virtually identical to the sequences of the F. tularensis strains, thereby supporting the hypothesis that these organisms are members of the same species. On the basis of the observed differences, primer pairs were designed to distinguish strains by using the PCR at the genus, species, and subspecies levels. This permitted sensitive identification of strains belonging to the genus Francisella and discrimination of the species F. tularensis and F. philomiragia.

Piscirickettsia salmonis gen. nov., sp. nov., the causative agent of an epizootic disease in salmonid fishes.

A novel intracellular pathogen morphologically similar to the ehrlichiae has been isolated in cell culture and identified as the cause of an epizootic disease of salmonid fish. Like the ehrlichiae, the salmonid pathogen, designated strain LF-89, replicates within membrane-bound cytoplasmic vacuoles in host cells. This agent is the first with characteristics of this type to be isolated from a fish. Analysis of the LF-89 16S rRNA indicated that, unlike the ehrlichiae, LF-89 is a gamma proteobacterium distantly related to Coxiella burnetii and perhaps Wolbachia persica. A new genus and species (Piscirickettsia salmonis gen. nov., sp. nov.) are proposed for this organism, with ATCC(R) VR 1361 as the type strain.

Malpighian Tubule Ultrastructure of Female Argas (Persicargas) arboreus (Acari: Ixodoidea: Argasidae) During and After Feeding

Malpighian tubules of the female tick Argas (Persicargas) arboreus Kaiser, Hoogstraal & Kohls consist of a region of structurally different pyramidal and cuboidal cells along the entire length of the tubule. In unfed ticks, the abundant pyramidal cells are characterized by apically projected microvilli and basal membrane infoldings and contain rough endoplasmic reticulum, membrane-bound vacuoles, and microtubules. Cuboidal cells have longer microvilli and a few basal membrane infoldings; their cytoplasm contains lipidlike vacuoles associated with glycogenlike particles. As feeding progresses, pyramidal cells become rich in glycogenlike particles that could be the source of energy required during feeding. These cells are possibly involved in formation of guanine spherules as an excretory product. Cuboidal cells replace their glycogenlike particles seen in unfed ticks with lipidlike droplets, which may be the source of energy required mainly after detachment. These cells reflect features of epithelia involved in water and ion transport. Single and colonial forms of the rickettsialike symbiote Wolbachia persica (Suitor & Weiss, 1961) are distributed along the entire length of the tubule except for a few cells near the rectal sac. The single forms increase rapidly during feeding, but the colonial forms are absent.

Isolation and characterization of symbiotes from the Rocky Mountain wood tick, Dermacentor andersoni

Wolbachia-like symbiotes in the Rocky Mountain wood tick, Dermacentor andersoni, were isolated repeatedly by injection of ovarial tissues into 5-day-old chick embryos. In Giemsa-stained smears of infected embryo tissues, the organisms appeared as blueish or pinkstained coccal bodies indistinguishable from those seen in the ovaries of ticks, where they are located in the luminal epithelium and funicle cells, as well as in oocytes. Electron microscopy revealed that these symbiotes are highly pleomorphic and vary in size from 0.6 to 3.4 μm in diameter. Their fine structure in tissue cells is differentiated into a granular, cortical region, which contains densely stained ribosomes, and a medullary region consisting of a diffuse reticulum partially or completely devoid of granular material or ribosomes. Multiplication is by binary fission. Each organism is delimited by a distinct plasmalemma; a cell wall as in bacterial and rickettsial agents was not observed in organisms from ovarial tissues. Symbiotes cultivated in chick embryos and then injected intracoelomically into adult D. andersoni, developed rapidly and produced massive infestations in hemocytes, hypodermal tissues, salivary glands, and in connective tissues surrounding midgut, Malpighian tubules, and ovary. In hypodermal tissue, organisms with a distinct bilayered cell envelope were occasionally detected. The massive invasion of tissues by injected symbiotes invariably proved fatal for ticks. Results of complement-fixation tests and of fluorescent antibody staining indicated that symbiotes in D. andersoni are closely related to Wolbachia persica, previously isolated from Argas arboreus.

The subgenus Persicargas (Ixodoidea, Argasidae, Argas). 13. Histological studies on A. (P.) arboreus Kaiser, Hoogstraal & Kohls.

The anatomy and histology of the capitulum, salivary glands, digestive system, and Malpighian tubules of each stage of Argas (Persicargas) arboreus Kaiser, Hoogstraal & Kohls are described. The fluid-tight buccal canal is formed by the close apposition of the dorsal chelicerae and ventral hypostome. There is no buccal cavity. The pharynx is the suctorial organ and the labrum is a prepharyngeal valve preventing blood regurgitation. The adult and nymphal salivary glands consist of nongranular alveoli (Type A) with 1 cell type and granule-secreting alveoli (Type B) of 3 structurally different cell types (Ba, Bb, Bc). These glands do not change significantly during or after feeding. Larval salivary glands are similar but lack Bb cells and enlarge greatly during feeding. The midgut of the adult and immature stages consists of a median stomach and 7 pairs of diverticula. The appearance of the gut epithelium varies according to the digestive activities. The yolk material filling the larval midgut is completely digested within the first 5 days following hatching. The blood ingested during the larval and nymphal stages is partially digested during the premolting periods; digestion is completed very slowly after molting to later instars or stages. In recently fed females, rapid digestion starts ca 3 days after feeding and continues until oviposition commences; later digestion is very slow. Digestion in males proceeds similarly but is less active. The epithelium of the 2 Malpighian tubules contains Wolbachia persica Suitor & Weiss except for a few cells near the excretory receptacle. The histological changes in the Malpighian tubules are more significant during rapid digestion and oviposition. The definite defecation cycle of each developmental stage is related to the activities in the midgut and Malpighian tubules.

Biochemical and Physiological Studies of Certain Ticks (Ixodoidea). Incorporation of Tritiated Tyrosine in the Digestive System of Nymphal Argas (Persicargas) arboreus (Argasidae)1

Malpighian tubules of Argas (Persicargas) arboreus Kaiser, Hoogstraal, & Kohls have alternating regions of 2 different cell types, 1 with acid, the other with neutral mucopolysaccharide inclusions. Wolbachia persica occurs in both cell types. The tubule lumen contains a weakly basophilic, homogeneous material with acid and neutral mucopolysaccharide granules and small guanine spherules. Near the rectal sac, the lumen contains a homogeneous acid mucopolysaccharide. All lumen contents pass to the rectal sac where spherule growth occurs with concurrent reduction in mucopolysaccharides and basophilic contents. After an in vitro bloodmeal to which 3H-tyrosine has been added, the malpighian tubule cells and lumen content incorporate the radioisotope. Incorporation in rectal sac cells occurs when the amount of radioactive material is reducing and the guanine spherules are growing. Guanine and hematin in the rectal sac are nonradioactive. The excretory material is postulated to include a soluble precursor of guanine, perhaps guanosine, linked to the mucopolysaccharide from which insoluble guanine is liberated by enzymic action or by changes in the physical environment of the tubules and sac.

Biochemical and Physiological Studies of Certain Ticks (Ixodoidea). Incorporation of Tritiated Tyrosine in the Excretory System of Nymphal Argas (Persicargas) arboreus (Argasidae)1

Malpighian tubules of Argas (Persicargas) arboreus Kaiser, Hoogstraal, & Kohls have alternating regions of 2 different cell types, 1 with acid, the other with neutral mucopolysaccharide inclusions. Wolbachia persica occurs in both cell types. The tubule lumen contains a weakly basophilic, homogeneous material with acid and neutral mucopolysaccharide granules and small guanine spherules. Near the rectal sac, the lumen contains a homogeneous acid mucopolysaccharide. All lumen contents pass to the rectal sac where spherule growth occurs with concurrent reduction in mucopolysaccharides and basophilic contents. After an in vitro bloodmeal to which 3H-tyrosine has been added, the malpighian tubule cells and lumen content incorporate the radioisotope. Incorporation in rectal sac cells occurs when the amount of radioactive material is reducing and the guanine spherules are growing. Guanine and hematin in the rectal sac are nonradioactive. The excretory material is postulated to include a soluble precursor of guanine, perhaps guanosine, linked to the mucopolysaccharide from which insoluble guanine is liberated by enzymic action or by changes in the physical environment of the tubules and sac.

LIPID METABOLISM OF THE RICKETTSIALIKE MICROORGANISM WOLBACHIA PERSICA. II. STUDIES WITH LABELED NONLIPID SUBSTRATES.

Journal Article Lipid Metabolism of the Rickettsialike Microorganism Wolbachia Persica: II. Studies with Labeled Nonlipid Substrates Get access E. M. Neptune, Jr., E. M. Neptune, Jr. Department of Microbiology and the Department of Clinical Investigation, Naval Medical Research Institute, Bethesda 14, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar E. Weiss, E. Weiss Department of Microbiology and the Department of Clinical Investigation, Naval Medical Research Institute, Bethesda 14, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar J. A. Davies J. A. Davies Department of Microbiology and the Department of Clinical Investigation, Naval Medical Research Institute, Bethesda 14, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar The Journal of Infectious Diseases, Volume 114, Issue 1, February 1964, Pages 45–49, https://doi.org/10.1093/infdis/114.1.45 Published: 01 February 1964 Article history Received: 17 July 1963 Published: 01 February 1964

LIPID METABOLISM OF THE RICKETTSIALIKE MICROORGANISM WOLBACHIA PERSICA. III. COMPARISON WITH OTHER METABOLIC ACTIVITIES.

Journal Article Lipid Metabolism of the Rickettsialike Microorganism Wolbachia Persica: III. Comparison with Other Metabolic Activities Get access E. Weiss, E. Weiss Department of Microbiology and the Department of Clinical Investigation, Naval Medical Research Institute, Bethesda 14, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar E. M. Neptune, Jr., E. M. Neptune, Jr. Department of Microbiology and the Department of Clinical Investigation, Naval Medical Research Institute, Bethesda 14, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar J. A. Davies J. A. Davies Department of Microbiology and the Department of Clinical Investigation, Naval Medical Research Institute, Bethesda 14, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar The Journal of Infectious Diseases, Volume 114, Issue 1, February 1964, Pages 50–54, https://doi.org/10.1093/infdis/114.1.50 Published: 01 February 1964 Article history Received: 17 July 1963 Published: 01 February 1964

Respiration of a rickettsialike microorganism, Wolbachia persica.

Journal Article Respiration of a Rickettsialike Microorganism, Wolbachia Persica Get access E. Weiss, E. Weiss From the Division of Virology, Naval Medical Research Institute, Bethesda 14, Maryland, and the Department of Microbiology, University of Maryland Medical School, Baltimore 1, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar W. F. Myers, W. F. Myers From the Division of Virology, Naval Medical Research Institute, Bethesda 14, Maryland, and the Department of Microbiology, University of Maryland Medical School, Baltimore 1, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar E. C. Suitor, Jr., E. C. Suitor, Jr. From the Division of Virology, Naval Medical Research Institute, Bethesda 14, Maryland, and the Department of Microbiology, University of Maryland Medical School, Baltimore 1, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar E. M. Neptune, Jr. E. M. Neptune, Jr. From the Division of Virology, Naval Medical Research Institute, Bethesda 14, Maryland, and the Department of Microbiology, University of Maryland Medical School, Baltimore 1, Maryland Search for other works by this author on: Oxford Academic PubMed Google Scholar The Journal of Infectious Diseases, Volume 110, Issue 2, March 1962, Pages 155–164, https://doi.org/10.1093/infdis/110.2.155 Published: 01 March 1962 Article history Received: 16 October 1961 Published: 01 March 1962