Pilot survey of mosquitoes (Diptera: Culicidae) from southeastern Georgia, USA for Wolbachia and Rickettsia felis (Rickettsiales: Rickettsiaceae).

BACKGROUND & OBJECTIVES: Mosquito surveillance is one of the critical functions of local health departments, particularly in the context of outbreaks of severe mosquito-borne viral infections. Unfortunately, some viral and parasitic infections transmitted by mosquitoes, manifests non-specific clinical symptoms which may actually be of rickettsial etiology, including Rickettsia felis infections. This study tested the hypothesis that mosquitoes from southeastern Georgia, USA may be infected with Rickettsia felis and Wolbachia, an endosymbiotic bacterium of the order Rickettsiales. METHODS: Specimens of the five most common mosquito species occurring in the region were collected using gravid and light-traps and identified using morphological keys. Mosquitoes were then pooled by species, sex, trap and collection site and their DNA was extracted. Molecular methods were used to confirm mosquito identification, and presence of Wolbachia and R. felis. RESULTS: Wolbachia DNA was detected in 90.8% of the mosquito pools tested, which included 98% pools of Cx. quinquefasciatus Say (Diptera: Culicidae), 95% pools of Ae. albopictus Skuse (Diptera: Culicidae), and 66.7% of pools of Cx. pipiens complex. Samples of An. punctipennis Say (Diptera: Culicidae) and An. crucians Wiedemann (Diptera: Culicidae) were tested negative for Wolbachia DNA. Three genotypes of Wolbachia sp. belonging to Group A (1 type) and Group B (2 types) were identified. DNA of R. felis was not found in any pool of mosquitoes tested. INTERPRETATION & CONCLUSIONS: This study provides a pilot data on the high presence of Wolbachia in Cx. quinque-fasciatus and Ae. albopictus mosquitoes prevalent in the study region. Whether the high prevalence of Wolbachia and its genetic diversity in mosquitoes affects the mosquitoes' susceptibility to R. felis infection in Georgia will need further evaluation.

Diversity and environmental distribution of the cosmopolitan endosymbiont "Candidatus Megaira".

Members of the order Rickettsiales are often found in association with ciliated protists. An interesting case is the bacterial endosymbiont "Candidatus Megaira", which is phylogenetically closely related to the pathogen Rickettsia. "Candidatus Megaira" was first described as an intracellular bacterium in several ciliate species. Since then it has been found in association with diverse evolutionary distantly-related hosts, among them other unicellular eukaryotes, and also algae, and metazoa, such as cnidarians. We provide the characterization of several new strains of the type species "Candidatus Megaira polyxenophila", and the multidisciplinary description of a novel species, "Candidatus Megaira venefica", presenting peculiar features, which highlight the diversity and variability of these widespread bacterial endosymbionts. Screening of the 16S rRNA gene short amplicon database and phylogenetic analysis of 16S rRNA gene hypervariable regions revealed the presence of further hidden lineages, and provided hints on the possibility that these bacteria may be horizontally transmitted among aquatic protists and metazoa. The phylogenetic reconstruction supports the existence of at least five different separate species-level clades of "Candidatus Megaira", and we designed a set of specific probes allowing easy recognition of the four major clades of the genus.

Molecular characterization of Haemaphysalis longicornis-borne rickettsiae, Republic of Korea and China.

Haemaphysalis longicornis, the cattle tick or bush tick, has an extended distribution throughout Asia and the Pacific region, including China, Russia, the Republic of Korea (ROK), Japan, Australia, New Zealand, and the South Pacific islands. It is an obligate ectoparasite found commonly on medium to large sized wild and domestic animals, with humans as an accidental host. Haemaphysalis longicornis transmits a number of pathogens, including severe fever with thrombocytopenia syndrome and tick-borne encephalitis viruses, bacteria, helminths, and protozoans, that impact on veterinary (wild and domestic animals) and human health. Surveys of rickettsial pathogens associated with H. longicornis from China, the ROK, and Japan have resulted in the discovery of more than 35 incompletely characterized molecular isolates of Rickettsia. In response to the increased global threat of tick-borne rickettsial diseases, H. longicornis collected in the ROK and China were assessed in our laboratory and two additional Rickettsia spp. isolates (ROK-HL727 and XinXian HL9) were identified. These agents were fully characterized by multilocus sequence typing using partial gene fragment sequences of rrs, gltA, ompA, ompB, and sca4. Phylogenetic comparisons of these Rickettsia isolates with known Rickettsia species and other molecular isolates identified from H. longicornis were performed to better understand their interrelationships. Phylogenetic analysis of the sequences from these 5 gene fragments showed that ROK-HL727 was closely related to rickettsial isolates of H. longicornis previously reported from China, the ROK and Japan, but distinct from any currently recognized Rickettsia species. It therefore qualifies genetically as a new species, introduced herein as Candidatus Rickettsia longicornii. The XinXian-HL9 isolate detected from China was determined to be genetically similar to the human pathogen Rickettsia heilongjiangensis. People living and working in areas where H. longicornis is endemic should be aware of the potential for rickettsial diseases.

Prevalence of Tick-Borne Pathogens from Ticks Collected from Cattle and Wild Animals in Tanzania in 2012.

This study was aimed to disclose the prevalence rate of tick-borne pathogens from ticks collected from cattle and wild animals in Tanzania in 2012. Ticks were collected from slaughtered cattle and dead wild animals from November 5 to December 23, 2012 and identified. PCR for detecting Anaplasmataceae, Piroplamidae, Rickettsiaceae, Borrelia spp., and Coxiella spp. were done. Among those tested, Rickettsiaceae, Piroplasmidae, and Anaplasmataceae, were detected in ticks from the 2 regions. Rickettsiaceae represented the major tick-borne pathogens of the 2 regions. Ticks from animals in Maswa were associated with a higher pathogen detection rate compared to that in ticks from Iringa. In addition, a higher pathogen detection rate was observed in ticks infesting cattle than in ticks infesting wild animals. All examined ticks of the genus Amblyomma were infected with diverse pathogens. Ticks of the genera Rhipicephalus and Hyalomma were infected with 1 or 2 pathogens. Collectively, this study provides important information regarding differences in pathogen status among various regions, hosts, and tick species in Tanzania. Results in this study will affect the programs to prevent tick-borne diseases (TBD) of humans and livestock in Tanzania.

Diversity and metabolic potential of the microbiota associated with a soil arthropod.

Springtails are important members of the soil fauna and play a key role in plant litter decomposition, for example through stimulation of the microbial activity. However, their interaction with soil microorganisms remains poorly understood and it is unclear which microorganisms are associated to the springtail (endo) microbiota. Therefore, we assessed the structure of the microbiota of the springtail Orchesella cincta (L.) using 16S rRNA gene amplicon sequencing. Individuals were sampled across sites in the field and the microbiota and in particular the endomicrobiota were investigated. The microbiota was dominated by the families of Rickettsiaceae, Enterobacteriaceae and Comamonadaceae and at the genus level the most abundant genera included Rickettsia, Chryseobacterium, Pseudomonas, and Stenotrophomonas. Microbial communities were distinct for the interior of the springtails for measures of community diversity and exhibited structure according to collection sites. Functional analysis of the springtail bacterial community suggests that abundant members of the microbiota may be associated with metabolism including decomposition processes. Together these results add to the understanding of the microbiota of springtails and interaction with soil microorganisms including their putative functional roles.

Extensive diversity of rickettsiales bacteria in ticks from Wuhan, China.

Rickettsiales bacteria are important agents of (re)emerging infectious diseases, with ticks playing a key role in their evolution and transmission. We collected 1079 hard ticks belonging to five species (Ixodes sinensis, Rhipicephalus microplus, Haemaphysalis flava, Haemaphysalis hystricis and Haemaphysalis longicornis) from cattle and goats in Wuhan city, Hubei province, China. The dominant tick species was H. longicornis (578, 53.57%), followed by R. microplus (354, 32.81%), H. hystricis (62, 5.75%), H. flava (57, 5.28%), and I. sinensis (28, 2.59%). Rickettsiales bacteria were identified in these ticks by amplifying the Rickettsiales 16S rRNA (rrs), citrate synthase (gltA), and heat shock protein (groEL) genes. The rrs gene of Rickettsiales was positive in 32 (2.97%) ticks, including 2 cases of co-infection, with 4 (0.69%) in H. longicornis, 15 (4.24%) in R. microplus, 7 (12.28%) in H. flava, 1 (1.61%) in H. hystricis, and 5 (17.86%) in I. sinensis ticks. Phylogenetic analysis revealed the presence of six recognized and seven Candidatus species of Rickettsiaceae, Anaplasmataceae and Candidatus Midichloriaceae. Notably, one lineage within both Ehrlichia and Candidatus Midichloriaceae was distinct from any known Rickettsiales, suggesting the presence of potentially novel species of Rickettsiales bacteria. In sum, these data reveal an extensive diversity of Rickettsiales in ticks from Wuhan, highlighting the need to understand Rickettsiales infection in local animals and humans.

Distribution and molecular characteristics of rickettsiae found in ticks across Central Mongolia.

BACKGROUND: Little is known regarding tick-borne diseases in Mongolia, despite having 26% of the population still living nomadic pastoral lifestyles. A total of 1497 adult unfed ticks: 261 Ixodes persulcatus, 795 Dermacentor nuttalli, and 441 Hyalomma asiaticum, were collected from three ecologically distinct regions in Central Mongolia. Tick pools (n = 299) containing ~5 ticks each, were tested for Rickettsia and Tick-borne encephalitis virus (TBEV) using nested polymerase chain reaction, reverse transcription-PCR, and quantitative real-time RT-PCR. RESULTS: Assays yielded pooled prevalence of 92.5% (49/53) and 1.9% (1/53) for pooled I. persulcatus testing positive for "Candidatus Rickettsia tarasevichiae" and TBEV, respectively, while Rickettsia raoultii was found in 72.8% (115/158) of pooled D. nuttalli samples. When calculating a maximum likelihood estimation, an estimated 46.6% (95% CI: 35.2-63.6%) of I. persulcatus ticks in the pooled sample were infected with "Candidatus R. tarasevichiae". CONCLUSIONS: Both "Candidatus R. tarasevichiae" and R. raoultii are recognized as emerging tick-borne pathogens, with this being one of the first reports of "Candidatus R. tarasevichiae" in Mongolia. Given that "Candidatus R. tarasevichiae" shares the same vector (I. persulcatus) as TBEV, and infections may present with similar symptoms, Mongolian physicians treating suspected cases of TBEV should include "Candidatus R. tarasevichiae" infection in their differential diagnosis and consider prescribing antimicrobial therapy.

Disentangling the Taxonomy of Rickettsiales and Description of Two Novel Symbionts ("Candidatus Bealeia paramacronuclearis" and "Candidatus Fokinia cryptica") Sharing the Cytoplasm of the Ciliate Protist Paramecium biaurelia.

In the past 10 years, the number of endosymbionts described within the bacterial order Rickettsiales has constantly grown. Since 2006, 18 novel Rickettsiales genera inhabiting protists, such as ciliates and amoebae, have been described. In this work, we characterize two novel bacterial endosymbionts from Paramecium collected near Bloomington, IN. Both endosymbiotic species inhabit the cytoplasm of the same host. The Gram-negative bacterium "Candidatus Bealeia paramacronuclearis" occurs in clumps and is frequently associated with the host macronucleus. With its electron-dense cytoplasm and a distinct halo surrounding the cell, it is easily distinguishable from the second smaller symbiont, "Candidatus Fokinia cryptica," whose cytoplasm is electron lucid, lacks a halo, and is always surrounded by a symbiontophorous vacuole. For molecular characterization, the small-subunit rRNA genes were sequenced and used for taxonomic assignment as well as the design of species-specific oligonucleotide probes. Phylogenetic analyses revealed that "Candidatus Bealeia paramacronuclearis" clusters with the so-called "basal" Rickettsiales, and "Candidatus Fokinia cryptica" belongs to "Candidatus Midichloriaceae." We obtained tree topologies showing a separation of Rickettsiales into at least two groups: one represented by the families Rickettsiaceae, Anaplasmataceae, and "Candidatus Midichloriaceae" (RAM clade), and the other represented by "basal Rickettsiales," including "Candidatus Bealeia paramacronuclearis." Therefore, and in accordance with recent publications, we propose to limit the order Rickettsiales to the RAM clade and to raise "basal Rickettsiales" to an independent order, Holosporales ord. nov., inside Alphaproteobacteria, which presently includes four family-level clades. Additionally, we define the family "Candidatus Hepatincolaceae" and redefine the family Holosporaceae IMPORTANCE: In this paper, we provide the characterization of two novel bacterial symbionts inhabiting the same Paramecium host (Ciliophora, Alveolata). Both symbionts belong to "traditional" Rickettsiales, one representing a new species of the genus "Candidatus Fokinia" ("Candidatus Midichloriaceae"), and the other representing a new genus of a "basal" Rickettsiales According to newly characterized sequences and to a critical revision of recent literature, we propose a taxonomic reorganization of "traditional" Rickettsiales that we split into two orders: Rickettsiales sensu stricto and Holosporales ord. nov. This work represents a critical revision, including new records of a group of symbionts frequently occurring in protists and whose biodiversity is still largely underestimated.

Detection of 'Candidatus Neoehrlichia mikurensis' and other Anaplasmataceae and Rickettsiaceae in Canidae in Switzerland and Mediterranean countries.

INTRODUCTION: 'Candidatus Neoehrlichia mikurensis' is an emerging tick-borne zoonotic agent that primarily affects immunocompromised human patients. Dogs and foxes are frequently exposed to ticks, and both species are in close proximity to humans. This is the first study to systematically investigate the occurrence of 'Candidatus Neoehrlichia mikurensis' in Canidae in Europa. We analyzed 1'739 blood samples from dogs in Switzerland, Italy, Spain and Portugal and 162 blood samples from free-ranging red foxes (Vulpes vulpes) in Switzerland. All samples were tested using a previously described multiplex real-time PCR for the Anaplasmataceae family, the 'Candidatus Neoehrlichia' genus and the 'Candidatus Neoehrlichia mikurensis' species. All Anaplasmataceae positive samples were subsequently tested using specific real-time PCRs for Anaplasma phagocytophilum, Anaplasma platys, Ehrlichia canis and Rickettsia helvetica. Among the tested animals, one dog from Zurich tested positive for 'Candidatus Neoehrlichia mikurensis'. The 12-year old West Highland white terrier had been splenectomized 3 months prior to the blood collection and presented with polyuria/polydipsia. Fanconi syndrome was diagnosed based on glucosuria with normoglycemia and hyperaminoaciduria. A. platys and E. canis were detected in 14/249 dogs from Sicily and Portugal; two of the dogs were coinfected with both agents. Four Swiss foxes tested positive for A. phagocytophilium. R. helvetica was detected for the first time in a red fox. In conclusion, 'Candidatus Neoehrlichia mikurensis' infection should be considered in sick dogs, particularly when immunocompromised. The pathogen seems not to be widespread in Canidae in the investigated countries. Conversely, other Anaplasmataceae were more readily detected in dogs and foxes.

INTRODUCTION: 'Candidatus Neoehrlichia mikurensis' est un agent de zoonose transmis par les tiques qui gagne en importance et concerne principalement les patients immunosupprimés. Les chiens comme les renards sont souvent concernés par des morsures de tiques et vivent en contact étroit avec les êtres humains. Dans le présent travail, nous étudions pour la première fois systématiquement la présence de 'Candidatus Neoehrlichia mikurensis' chez les canidés en Europe. Les échantillons sanguins analysés provenaient de 1'739 chiens de Suisse, d'Italie, d'Espagne et du Portugal ainsi que de 162 renards (Vulpes vulpes) de Suisse. Tous les échantillons ont été examinés avec un test de PCR multiplex en temps réel déjà publié quant à la présence d'agents de la famille des Anaplasmataceae, du genre 'Candidatus Neoehrlichia' et de l'espèce 'Candidatus Neoehrlichia mikurensis'. Les échantillons positifs aux Anaplasmataceae ont ensuite été testés avec un test PCR en temps réel spécifique quant à Anaplasma phagocytophilum, Anaplasma platys, Ehrlichia canis und Rickettsia helvetica. Parmi les échantillons examinés se trouvait celui d'un chien de Zürich qui était infecté par 'Candidatus Neoehrlichia mikurensis'. Ce West Highland White Terrier de 12 ans avait été présenté pour polyurie/polydipsie; il avait été splénectomisé trois mois avant la prise de l'échantillon. Au vu d'une glycosurie et d'une hyperaminoacidurie accompagnées d'une glycémie normale, on a posé le diagnostic de syndrome de Fanconi. A. platys et E. canis ont été mis en évidence chez 14/249 chiens provenant de Sicile et du Portugal; deux chiens étaient infectés par les deux agents pathogènes. Quatre renards suisses étaient positifs à A. phagocytophilium et R. helvetica a été trouvé pour la première fois chez un renard. En résumé, on peut dire qu'une infection à 'Candidatus Neoehrlichia mikurensis' chez un chien malade doit être prise en considération comme diagnostic différentiel, particulièrement chez les anomaux immunosupprimés. Toutefois cet agent n'est pas très répandu chez les canidés des pays examinés, contrairement aux autres Anaplasmataceae spp. qui ont été trouvées plus souvent chez les chiens et les renards.

Molecular detection of bacteria in the families Rickettsiaceae and Anaplasmataceae in northern crested caracaras (Caracara cheriway).

Bacterial pathogens of the families Anaplasmataceae and Rickettsiaceae are often spread to humans or other animals from bites from infected arthropod hosts. Recently, an increasing number of studies have implicated migratory birds in the circulation of these pathogens through the spread of arthropod vectors. However, few studies have examined the potential for resident bird populations to serve as reservoirs for these zoonoses. In this study, we used nested PCRs of the GroESL and 17 kDa genes to screen for Anaplasmataceae and Rickettsiaceae, respectively, in a resident population of the northern crested caracara (Caracara cheriway) from Florida (n=55). Additionally, a small number (n=6) of captive individuals from Texas were included. We identified one individual (1.64%) positive for Rickettsia felis and one (1.64%) positive for Ehrlichia chaffeensis; both these individuals were from Florida. Presence of these pathogens demonstrates that these birds are potential hosts; however, the low prevalence of infections suggests that these populations likely do not function as an ecological reservoir.

Rickettsiaceae and Anaplasmataceae infections in Ixodes ricinus ticks from urban and natural forested areas of Poland.

BACKGROUND: Ixodes ricinus is a major vector for a range of microbial pathogens and the most prevalent and widely distributed tick species on the European continent, occurring in both natural and urban habitats. Nevertheless, little is known about the relative density of ticks in these two ecologically distinct habitats and the diversity of tick-borne pathogens that they carry. METHODS: We compared densities of questing I. ricinus nymphs and adults in urban and natural habitats in Central and Northeastern Poland, assessed the prevalence and rate of co-infection with A. phagocytophilum, Rickettsia, Ehrlichia and 'Ca. Neoehrlichia spp.' in ticks, and compared the diversity of tick-borne pathogens using molecular assays (PCR). RESULTS: Of the 1325 adults and nymphs, 6.2% were infected with at least one pathogen, with 4.4%, 1.7% and less than 0.5% being positive for the DNA of Rickettsia spp., A. phagocytophilum, Ehrlichia spp. and Ca. N. mikurensis, respectively. Although tick abundance was higher in natural habitats, the prevalence of the majority of pathogens was higher in urban forested areas. CONCLUSION: We conclude that: (i) zoonotic genetic variants of A. phagocytophilum are widely distributed in the Polish tick population, (ii) although the diversity of tick borne pathogens was higher in natural habitats, zoonotic species/strains were detected only in urban forests, (iii) and we provide the first description of Ca. N. mikurensis infections in ticks in Poland.

Differential susceptibility to the Withering Syndrome agent and renal coccidia in juvenile Haliotis rufescens, Haliotis discus hannai and the interspecific hybrid.

Withering Syndrome (WS) is a pathogenic chronic disease caused by the intracellular rickettsial-like bacterium "Candidatus Xenohaliotis californiensis" (WS-RLOs), which affects many abalone species. The renal coccidium (Margolisiella haliotis) has often been observed concurrent with WS infection. The red abalone Haliotis rufescens is a very susceptible species to WS and is also infected by the coccidium M. haliotis. In contrast, the Japanese abalone Haliotis discus hannai is not infected by these parasites. Interspecific hybridization is a method for improving important traits in animal husbandry. The objective of this study was to determine susceptibility to WS-RLO and M. haliotis infection in the hybrid generated from a cross between red and Japanese abalones. Juveniles from both species and the interspecific hybrid were challenged by exposure to effluent from red abalone adults infected with both parasites. The animals were analyzed by histology at 130days post-challenge. A 33% prevalence WS-RLOs was observed in the red abalone H. rufescens, whereas a 20% prevalence was observed in the hybrid. Infections were graded on a scale of 0-3. Of these red abalones infected, 53% presented grade 1 infection intensity, 10% had grade 2 infections, and 50% had grade 3 infections. However, the hybrids only presented intensities at the extremes of the scale; of those infected 33% showed grade 1 infections and 66% had grade 3 infections. The coccidium prevalence was 7% in red abalone individuals and 13% in the hybrid abalone. In contrast, the Japanese abalone did not present infections with either parasite. As with the prevalence, the infection intensities for the coccidium were higher in the hybrid abalone; of those infected 25% had grade 2 infections, and 75% had grade 3 infections, but the red abalone presented only grade 2 infection intensities. Therefore, the hybrid did not inherited non-susceptibility or resistance characteristics of the parental H. discus hannai and possessed biological conditions that could foster development of both parasites. Development of a culture based on this hybrid abalone should consider its susceptibility to infection by coccidian, WS-RLOs and the potential for developing the WS disease.

Bacterial DNA sifted from the Trichoplax adhaerens (Animalia: Placozoa) genome project reveals a putative rickettsial endosymbiont.

Eukaryotic genome sequencing projects often yield bacterial DNA sequences, data typically considered as microbial contamination. However, these sequences may also indicate either symbiont genes or lateral gene transfer (LGT) to host genomes. These bacterial sequences can provide clues about eukaryote-microbe interactions. Here, we used the genome of the primitive animal Trichoplax adhaerens (Metazoa: Placozoa), which is known to harbor an uncharacterized Gram-negative endosymbiont, to search for the presence of bacterial DNA sequences. Bioinformatic and phylogenomic analyses of extracted data from the genome assembly (181 bacterial coding sequences [CDS]) and trace read archive (16S rDNA) revealed a dominant proteobacterial profile strongly skewed to Rickettsiales (Alphaproteobacteria) genomes. By way of phylogenetic analysis of 16S rDNA and 113 proteins conserved across proteobacterial genomes, as well as identification of 27 rickettsial signature genes, we propose a Rickettsiales endosymbiont of T. adhaerens (RETA). The majority (93%) of the identified bacterial CDS belongs to small scaffolds containing prokaryotic-like genes; however, 12 CDS were identified on large scaffolds comprised of eukaryotic-like genes, suggesting that T. adhaerens might have recently acquired bacterial genes. These putative LGTs may coincide with the placozoan's aquatic niche and symbiosis with RETA. This work underscores the rich, and relatively untapped, resource of eukaryotic genome projects for harboring data pertinent to host-microbial interactions. The nature of unknown (or poorly characterized) bacterial species may only emerge via analysis of host genome sequencing projects, particularly if these species are resistant to cell culturing, as are many obligate intracellular microbes. Our work provides methodological insight for such an approach.

Lyme borreliosis spirochetes and spotted fever group rickettsiae in ixodid ticks from Pianosa island, Tuscany Archipelago, Italy.

A study on tick fauna and tick-borne pathogens was undertaken in Pianosa, an island in the Tuscany Archipelago that constitutes an important stopping and nesting point for migratory birds. Ticks were removed from feral cats and a few terrestrial birds, and host-seeking ticks were collected by dragging. A total of 89 ticks were found on animals: 57 Ixodes ventalloi Gil Collado, 1936 and 32 Ixodes acuminatus Neumann, 1901. Host-seeking ticks were 354 Hyalomma spp. larvae and 18 Hyalomma spp. adults, identified as Hyalomma marginatum C.L. Koch, 1844 (n=11) and 7 Hyalomma detritum Schulze, 1919 (n=7). A sample of adult ticks was subjected to molecular analyses to look for Rickettsia spp. and Borrelia burgdorferi sensu lato (s.l.). Sequence analysis of the 5S-23S intergenic spacer region and OspA gene of B. burgdorferi s.l.-positive samples showed the presence of Borrelia spielmanii (n=3; 3.7%, 95% confidence interval [CI] 0.08-10.4) and Borrelia valaisiana (n=13; 13.6%, 95% CI 7.0-23.0) in Ixodes ticks from cats and terrestrial birds. Ixodes spp. were also infected by Rickettsia helvetica (n=19; 23.4%, 95% CI 14.7-34.2). Finally, we detected Rickettsia aeschlimannii in 3 out of 12 host-seeking Hyalomma spp. adults tested (25%, 95% CI 5.5-57.2). Our study shows the presence of several tick-borne pathogens in Pianosa. Hyalomma spp. and Ixodes ticks other than I. ricinus seem to be involved in their epidemiological cycle, and birds could contribute to the pathogen dispersal along their migration routes. This is the first finding of B. spielmanii in Italy. We hypothesize the involvement of peridomestic rodents or hedgehogs in its maintenance in Pianosa.

Phage particles infecting branchial Rickettsiales-like organisms in banded carpet shell Polititapes virgineus (Bivalvia) from Galicia (NW Spain).

Basophilic intracellular prokaryotic-like colonies were observed in the gills of banded carpet shell Polititapes virgineus (= Tapes rhomboides) (Linnaeus, 1767) from a natural bed in Galicia (NW Spain). Light microscope observations suggested the presence of 2 types of colonies, but transmission electron microscopy revealed that these were the same Rickettsiales-like colonies, one infected and the other uninfected by phage particles. This is the first report of the presence of phage particles in Rickettsiales-like organisms in the gills of P. virgineus.

Spotted fever group rickettsiae in ticks collected from wild animals in Israel.

We report molecular evidence for the presence of spotted fever group rickettsiae (SFGR) in ticks collected from roe deer, addax, red foxes, and wild boars in Israel. Rickettsia aeschlimannii was detected in Hyalomma marginatum and Hyalomma detritum while Rickettsia massiliae was present in Rhipicephalus turanicus ticks. Furthermore, a novel uncultured SFGR was detected in Haemaphysalis adleri and Haemaphysalis parva ticks from golden jackals. The pathogenicity of the novel SFGR for humans is unknown; however, the presence of multiple SFGR agents should be considered when serological surveillance data from Israel are interpreted because of significant antigenic cross-reactivity among Rickettsia. The epidemiology and ecology of SFGR in Israel appear to be more complicated than was previously believed.

Infection prevalences of common tick-borne pathogens in adult lone star ticks (Amblyomma americanum) and American dog ticks (Dermacentor variabilis) in Kentucky.

Rocky Mountain spotted fever, Lyme disease, and ehrlichiosis are tick-borne diseases that are reported annually in Kentucky. We conducted a survey to describe infection prevalence of tick-borne pathogens in Amblyomma americanum and Dermacentor variabilis ticks collected in Kentucky. During 2007-2008, we collected 287 ticks (179 D. variabilis and 108 A. americanum) from canine, feral hog, horse, raccoon, white-tailed deer, and human hosts in six counties in Kentucky. Ticks were screened for Rickettsia spp., Borrelia spp., and Ehrlichia spp. by using polymerase chain reaction. Forty-one (14.3%) ticks (31 A. americanum and 10 D. variabilis) were polymerase chain reaction-positive for a Rickettsia spp. Fourteen (4.9%) ticks (6 A. americanum and 8 D. variabilis) were positive for E. chaffeensis, and 4 A. americanum (1.4%) were positive for E. ewingii. One (0.4%) A. americanum was positive for Borrelia lonestari. Although Rocky Mountain spotted fever is diagnosed in Kentucky, no R. rickettsii was found in ticks in this study.

Wild rodents and novel human pathogen candidatus Neoehrlichia mikurensis, Southern Sweden.

We examined small mammals as hosts for Anaplasmataceae in southern Sweden. Of 771 rodents, 68 (8.8%) were infected by Candidatus Neoehrlichia mikurensis, but no other Anaplasmataceae were found. Candidatus N. mikurensis has recently been found in human patients in Germany, Switzerland, and Sweden, which suggests that this could be an emerging pathogen in Europe.