Bartonella and Rickettsia in fleas and lice from mammals in South Carolina, U.S.A.

Species in the genera Bartonella and Rickettsia are vector-borne pathogens of humans and domestic animals. The natural reservoirs and enzootic transmission cycles of these bacteria are poorly known in South Carolina. Thirteen species of lice and fleas were collected from urban animals and screened for the presence of Bartonella and Rickettsia by PCR amplification using genus-specific primers. Bartonella henselae was present in cat fleas (Ctenocephalides felis) from Virginia opossums (Didelphis virginiana) and a novel genotype of Bartonella was detected in Orchopeas howardi from an eastern gray squirrel (Sciurus carolinensis). We detected R. typhi and three novel genotypes Rickettsia in other species of fleas and lice. Rickettsia typhi, the causative agent of murine typhus, was detected in two pools of lice (Enderleinellus marmotae) from the woodchuck (Marmota monax). Cat fleas harbored one of two novel genotypes of Rickettsia. A third novel Rickettsia was detected in Orchopeas howardi from an eastern gray squirrel.     

Prevalence and genetic diversity of bartonella species detected in different tissues of small mammals in Nepal

Bartonellae were detected in a total of 152 (23.7%) of 642 tissues from 108 (48.4%) of 223 small mammals trapped in several urban areas of Nepal. Based on rpoB and gltA sequence analyses, genotypes belonging to seven known Bartonella species and five genotypes not belonging to previously known species were identified in these animals.     

Acquisition of nonspecific Bartonella strains by the northern grasshopper mouse (Onychomys leucogaster)

Rodent-associated Bartonella species are generally host-specific parasites in North America. Here evidence that Bartonella species can 'jump' between host species is presented. Northern grasshopper mice and other rodents were trapped in the western USA. A study of Bartonella infection in grasshopper mice demonstrated a high prevalence that varied from 25% to 90% by location. Bartonella infection was detected in other rodent species with a high prevalence as well. Sequence analyses of gltA identified 29 Bartonella variants in rodents, 10 of which were obtained from grasshopper mice. Among these 10, only six variants were specific to grasshopper mice, whereas four were identical to variants specific to deer mice or 13-lined ground squirrels. Fourteen of 90 sequenced isolates obtained from grasshopper mice were strains found more commonly in other rodent species and were apparently acquired from these animals. The ecological behavior of grasshopper mice may explain the occurrence of Bartonella strains in occasional hosts. The observed rate at which Bartonella jumps from a donor host species to the grasshopper mouse was directly proportional to a metric of donor host density and to the prevalence of Bartonella in the donor host, and inversely proportional to the same parameters for the grasshopper mouse.     

Differences in the ecology of Bartonella infections of Apodemus flavicollis and Myodes glareolus in a boreal forest

The epidemiology of Bartonella species infecting Apodemus flavicollis and Myodes glareolus in a forest in Eastern Poland was followed for 2 years using mark-recapture. Infections could be acquired in any month, but prevalence, and probability of infection, peaked in the summer. There were significant differences in the pattern of infections between the two species. Both hosts were primarily infected as juveniles, but the probability of infection was highest for A. flavicollis, which, evidence suggests, experienced longer-lasting infections with a wider range of Bartonella genotypes. There was no evidence of increased host mortality associated with Bartonella, although the infection did affect the probability of recapture. Animals could become re-infected, generally by different Bartonella genotypes. Several longer lasting, poorly resolved infections of A. flavicollis involved more than 1 genotype, and may have resulted from sequential infections. Of 22 Bartonella gltA genotypes collected, only 2 (both B. grahamii) were shared between mice and voles; all others were specific either to A. flavicollis or to M. glareolus, and had their nearest relatives infecting Microtus species in neighbouring fields. This heterogeneity in the patterns of Bartonella infections in wild rodents emphasizes the need to consider variation between both, host species and Bartonella genotypes in ecological and epidemiological studies.     

Phylogenetic analysis of Bartonella detected in rodent fleas in Yunnan, China

Previous studies have demonstrated a diversity of Bartonella spp. in rodent populations in Yunnan Province, China. Although Bartonella spp. have been isolated from cat fleas and cattle ticks collected from their animal hosts, little is known about Bartonella carried by rodent fleas. In this study, Bartonella DNA was detected by polymerase chain reaction (PCR) in two of five species of rodent fleas. These included Xenopsylla cheopis and Ctenophthalmus lushuiensis, which were collected from Rattus tanezumi flavipectus and from the nests of voles, respectively, during 1997 from two sites in western Yunnan Province, China. Sequence analysis of the Bartonella citrate synthase gene (gltA) amplicons obtained from six of 65 grouped flea samples showed that Bartonella genetic variants were clustered in four groups. One from Xenopsylla cheopis was identical to Bartonella tribocorum, whereas the other three genotypes from Ctenophthalmus lushuiensis were related to the vole-associated Bartonella isolates and cat-associated Bartonella clarridgeiae. This is the first detection of this Bartonella variant from fleas in China. Therefore, further investigations are needed to clarify the distribution of Bartonella in rodents and their ectoparasites in China to define the role of these arthropods in the transmission routes of Bartonella.     

Presence of Bartonella species in wild carnivores of northern Spain

The genus Bartonella was detected by PCR in 5.7% (12/212) of wild carnivores from Northern Spain. Based on hybridization and sequence analyses, Bartonella henselae was identified in a wildcat (Felis silvestris), Bartonella rochalimae in a red fox (Vulpes vulpes) and in a wolf (Canis lupus), and Bartonella sp. in badgers (Meles meles).     

Prevalence of Bartonella henselae and Bartonella clarridgeiae in cats in the south of Brazil: a molecular study

Bartonella spp are the causative agent of cat scratch disease in humans. Cats are the natural reservoir of these bacteria and may infect humans through scratches, bites or fleas. Blood samples from 47 cats aged up to 12 months were collected for this study. All animals were lodged in municipal animal shelters in the Vale do Sinos region, Rio Grande do Sul, Brazil. Bartonella spp were detected by genus-specific polymerase chain reaction (PCR) and when the PCR was positive, the species were determined by DNA sequencing. A Giemsa-stained blood smear was also examined for the presence of intraerythrocytic elements suggestive of Bartonella spp infection. Phylogenetic analysis was also performed for all positive samples. Using molecular detection methods, Bartonella spp were detected in 17.02% (8/47) of the samples. In seven out of eight samples confirmed to be positive for Bartonella spp, blood smear examination revealed the presence of intraerythrocytic elements suggestive of Bartonella spp. Phylogenetic analysis characterized positive samples as Bartonella henselae (5) or Bartonella clarridgeiae (3). To the best of our knowledge, this is the first molecular study demonstrating the presence of Bartonella spp in cats from the Southern Region of Brazil.     

Vector transmission of Bartonella species with emphasis on the potential for tick transmission

Bartonella species are gram-negative bacteria that infect erythrocytes, endothelial cells and macrophages, often leading to persistent blood-borne infections. Because of the ability of various Bartonella species to reside within erythrocytes of a diverse number of animal hosts, there is substantial opportunity for the potential uptake of these blood-borne bacteria by a variety of arthropod vectors that feed on animals and people. Five Bartonella species are transmitted by lice, fleas or sandflies. However, Bartonella DNA has been detected or Bartonella spp. have been cultured from numerous other arthropods. This review discusses Bartonella transmission by sandflies, lice and fleas, the potential for transmission by other vectors, and data supporting transmission by ticks. Polymerase chain reaction (PCR) or culture methods have been used to detect Bartonella in ticks, either questing or host-attached, throughout the world. Case studies and serological or molecular surveys involving humans, cats and canines provide indirect evidence supporting transmission of Bartonella species by ticks. Of potential clinical relevance, many studies have proposed co-transmission of Bartonella with other known tick-borne pathogens. Currently, critically important experimental transmission studies have not been performed for Bartonella transmission by many potential arthropod vectors, including ticks.     

Association of Bartonella with the fleas (Siphonaptera) of rodents and bats using molecular techniques.

Bartonella spp. are putatively vector-borne bacterial agents of humans and animals. Fleas have been incriminated as vectors of Bartonella spp. and are suspected of transmitting Bartonella of rodents and bats, but some of these Bartonella spp. have not yet been directly detected in wild caught fleas. We report the molecular detection of Bartonella tribocorum, Bartonella vinsonii subsp. vinsonii, and two novel genotypes of Bartonella from the fleas Xenopsylla cheopis, Ctenophthalmus pseudagyrtes, Sternopsylla texanus, or Orchopeas howardi.     

Molecular detection of Bartonella species infecting rodents in Slovenia

Rodents, collected in three zoogeographical regions across Slovenia, were tested for the presence of bartonellae using direct PCR-based amplification of 16S/23S rRNA gene intergenic spacer region (ITS) fragments from splenic DNA extracts. Bartonella DNA was detected in four species of rodents, Apodemus flavicollis, Apodemus sylvaticus, Apodemus agrarius and Clethrionomys glareolus, in all three zoogeographic regions at an overall prevalence of 40.4%. The prevalence of infection varied significantly between rodent species and zoogeographical regions. Comparison of ITS sequences obtained from bartonellae revealed six sequence variants. Four of these matched the ITS sequences of the previously recognized species, Bartonella taylorii, Bartonella grahamii, Bartonella doshiae and Bartonella birtlesii, but one was new. The identity of the bartonellae from which the novel ITS sequences was obtained were further assessed by sequence analysis of cell division protein-encoding gene (ftsZ) fragments. This analysis demonstrated that the strain is most likely a representative of possible new species within the genus.     

Investigation of Bartonella acquisition and transmission in Xenopsylla ramesis fleas (Siphonaptera: Pulicidae)

Bartonella are emerging and re-emerging pathogens affecting humans and a wide variety of animals including rodents. Horizontal transmission of Bartonella species by different hematophagous vectors is well acknowledged but vertical transmission (from mother to offspring) is questionable and was never explored in fleas. The aim of this study was to investigate whether the rodent flea, Xenopsylla ramesis, can acquire native Bartonella from wild rodents and transmit it transovarially. For this aim, Bartonella-free laboratory-reared X. ramesis fleas were placed on six naturally Bartonella-infected rodents and six species-matched Bartonella-negative rodents (three Meriones crassus jirds, two Gerbillus nanus gerbils and one Gerbillus dasyurus gerbil) for 7 days, 12-14h per day. The fleas that were placed on the Bartonella-positive rodents acquired four different Bartonella genotypes. Eggs and larvae laid and developed, respectively, by fleas from both rodent groups were collected daily for 7 days and molecularly screened for Bartonella. All eggs and larvae from both groups were found to be negative for Bartonella DNA. Interestingly, two of five gut voids regurgitated by Bartonella-positive fleas contained Bartonella DNA. The naturally infected rodents remained persistently infected with Bartonella for at least 89 days suggesting their capability to serve as competent reservoirs for Bartonella species. The findings in this study indicate that X. ramesis fleas can acquire several Bartonella strains from wild rodents but cannot transmit Bartonella transovarially.     

Three pathogens in sympatric populations of pumas, bobcats, and domestic cats: implications for infectious disease transmission

Anthropogenic landscape change can lead to increased opportunities for pathogen transmission between domestic and non-domestic animals. Pumas, bobcats, and domestic cats are sympatric in many areas of North America and share many of the same pathogens, some of which are zoonotic. We analyzed bobcat, puma, and feral domestic cat samples collected from targeted geographic areas. We examined exposure to three pathogens that are taxonomically diverse (bacterial, protozoal, viral), that incorporate multiple transmission strategies (vector-borne, environmental exposure/ingestion, and direct contact), and that vary in species-specificity. Bartonella spp., Feline Immunodeficiency Virus (FIV), and Toxoplasma gondii IgG were detected in all three species with mean respective prevalence as follows: puma 16%, 41% and 75%; bobcat 31%, 22% and 43%; domestic cat 45%, 10% and 1%. Bartonella spp. were highly prevalent among domestic cats in Southern California compared to other cohort groups. Feline Immunodeficiency Virus exposure was primarily associated with species and age, and was not influenced by geographic location. Pumas were more likely to be infected with FIV than bobcats, with domestic cats having the lowest infection rate. Toxoplasma gondii seroprevalence was high in both pumas and bobcats across all sites; in contrast, few domestic cats were seropositive, despite the fact that feral, free ranging domestic cats were targeted in this study. Interestingly, a directly transmitted species-specific disease (FIV) was not associated with geographic location, while exposure to indirectly transmitted diseases--vector-borne for Bartonella spp. and ingestion of oocysts via infected prey or environmental exposure for T. gondii--varied significantly by site. Pathogens transmitted by direct contact may be more dependent upon individual behaviors and intra-specific encounters. Future studies will integrate host density, as well as landscape features, to better understand the mechanisms driving disease exposure and to predict zones of cross-species pathogen transmission among wild and domestic felids.     

Molecular Characterization of Enterocytozoon bieneusi in Wild Carnivores in Spain

Microsporidia comprises a diverse group of obligate intracellular parasites that infect a broad range of invertebrates and vertebrates. Among Microsporidia, Enterocytozoon bieneusi is the most frequently detected species in humans and animals worldwide bringing into question the possible role of animal reservoirs in the epidemiology of this pathogen. Although E. bieneusi is an emerging zoonotic pathogen able to infect many domestic and wild mammals that could act as reservoir of infection for humans and other animals, only few studies have documented its occurrence in wild carnivores. To determine the occurrence of E. bieneusi in wild carnivores, we examined 190 wild carnivores collected from different locations in Spain. Twenty‐five fecal samples (13.2%) from three host species (European badger, beech marten, and red fox) were E. bieneusi‐positive by PCR. Nucleotide sequence analysis of the ITS region revealed a high degree of genetic diversity with a total of eight distinct genotypes including four known (PtEbIX, S5, S9, and WildBoar3) and four novel (EbCar1‐EbCar4) genotypes identified. Phylogenetic analysis showed that the four novel genotypes (EbCar1‐EbCar4), S5, S9, and WildBoar3 clustered within the previously designated zoonotic Group 1. Our results demonstrate that human‐pathogenic genotypes are present in wild carnivores, corroborating their potential role as a source of human infection and environmental contamination.     

Bartonella species in fleas from Palestinian territories: Prevalence and genetic diversity

Bartonellosis is an infectious bacterial disease. The prevalence and genetic characteristics of Bartonella spp. in fleas of wild and domestic animals from Palestinian territories are described. Flea samples (n=289) were collected from 121 cats, 135 dogs, 26 hyraxes and seven rats from northern (n=165), central (n=113), and southern Palestinian territories (n=11). The prevalent flea species were: Ctenocephalides felis (n=119/289; 41.2%), Ctenocephalides canis (n=159/289; 55%), and Xenopsylla sp. (n=7/289; 2.4%). Targeting the Intergenic Transcribed Spacer (ITS) locus, DNA of Bartonella was detected in 22% (64/289) of all fleas. Fifty percent of the C. felis and 57% of the Xenopsylla sp. contained Bartonella DNA. DNA sequencing showed the presence of Bartonella clarridgeiae (50%), Bartonella henselae (27%), and Bartonella koehlerae (3%) in C. felis. Xenopsylla sp. collected from Rattus rattus rats were infected with Bartonella tribocorum, Bartonella elizabethae, and Bartonella rochalimae. Phylogenetic sequence analysis using the 16S ribosomal RNA gene obtained four genetic clusters, B. henselae and B. koehlerae as subcluster 1, B. clarridgeiae as cluster 2, while the rat Bartonella species (B. tribocorum and B. elizabethae) were an outgroup cluster. These findings showed the important role of cat and rat fleas as vectors of zoonotic Bartonella species in Palestinian territories. It is hoped that this publication will raise awareness among physicians, veterinarians, and other health workers of the high prevalence of Bartonella spp. in fleas in Palestinian territories and the potential risk of these pathogens to humans and animals in this region.     

Molecular Characterization of Human-Pathogenic Microsporidia and Cyclospora cayetanensis Isolated from Various Water Sources in Spain: a Year-Long Longitudinal Study

Recent studies suggest the involvement of water in the epidemiology of Cyclospora cayetanensis and some microsporidia. A total of 223 samples from four drinking water treatment plants (DWTPs), seven wastewater treatment plants (WWTPs), and six locations of influence (LI) on four river basins from Madrid, Spain, were analyzed from spring 2008 to winter 2009. Microsporidia were detected in 49% of samples (109/223), Cyclospora spp. were detected in 9% (20/223), and both parasites were found in 5.4% (12/223) of samples. Human-pathogenic microsporidia were detected, including Enterocytozoon bieneusi (C, D, and D-like genotypes), Encephalitozoon intestinalis, Encephalitozoon cuniculi (genotypes I and III), and Anncaliia algerae. C. cayetanensis was identified in 17 of 20 samples. To our knowledge, this is the first study that shows a year-long longitudinal study of C. cayetanensis in drinking water treatment plants. Additionally, data about the presence and molecular characterization of the human-pathogenic microsporidia in drinking water, wastewater, and locations of influence during 1 year in Spain are shown. It is noteworthy that although the DWTPs and WWTPs studied meet European and national regulations on water sanitary quality, both parasites were found in water samples from these plants, supporting the idea that new and appropriate controls and regulations for drinking water, wastewater, and recreational waters should be proposed to avoid health risks from these pathogens.     

Bartonella species in bat flies (Diptera: Nycteribiidae) from western Africa

Bat flies are obligate ectoparasites of bats and it has been hypothesized that they may be involved in the transmission of Bartonella species between bats. A survey was conducted to identify whether Cyclopodia greefi greefi (Diptera: Nycteribiidae) collected from Ghana and 2 islands in the Gulf of Guinea harbour Bartonella. In total, 137 adult flies removed from Eidolon helvum, the straw-coloured fruit bat, were screened for the presence of Bartonella by culture and PCR analysis. Bartonella DNA was detected in 91 (66·4%) of the specimens examined and 1 strain of a Bartonella sp., initially identified in E. helvum blood from Kenya, was obtained from a bat fly collected in Ghana. This is the first study, to our knowledge, to report the identification and isolation of Bartonella in bat flies from western Africa.     

Experimental infection of cotton rats with three naturally occurring Bartonella species

The kinetics of infection and humoral immune response of laboratory-bred cotton rats (Sigmodon hispidus) challenged with three Bartonella spp. recovered from the blood of naturally infected cotton rats captured in Georgia (USA) are described. Bartonella spp. infection, as determined by bacteremia, occurred in all 18 cotton rats inoculated with live Bartonella of each species at either a low dose, 10(3) colony-forming units (CFU's), or high dose, 10(7) CFU. Cotton rats inoculated with lower doses of Bartonella spp. developed higher bacteremia that persisted for longer periods than in those inoculated with high doses. Peak bacteremia varied among Bartonella spp, ranging from 10(4) to 10(6) CFUs per 1.0 ml of blood. Antibody measured by immunofluorescence assays using species-specific antigens indicated more rapidly rising and higher antibody titers in cotton rats challenged with high doses vs. low doses and with inactivated bacteria vs. live bacteria. Each group of rats produced high IgG titers to the homologous challenge antigen; low or unmeasurable cross-reactivity was detected to heterologous Bartonella antigens. Exposure of cotton rats to a specific Bartonella sp. resulted in protection, as measured by detectable bacteremia, in eight of nine animals challenged with the same Bartonella sp. used initially; no evidence of resistance to secondary challenge with different Bartonella spp. was obtained. Cross-protection between Bartonella spp., isolated from the same rodent species, may not occur.     

Demographic features of Bartonella infections in Richardson's ground squirrels (Spermophilus richardsonii)

The epidemiology of Bartonella infections in Richardson's ground squirrels (Spermophilus richardsonii) was studied at multiple sites in Saskatchewan, Canada, from 2002 to 2004. The overall prevalence of Bartonella infection was 48%. Juvenile squirrels were significantly more likely to be infected with Bartonella than were adults (58% and 37%, respectively), and juvenile animals also were significantly more likely to have high levels of bacteremia compared to adult animals. Prevalence of Bartonella infection appeared to decrease with age; only 24% of animals known to be > or = 2 yr old were infected with Bartonella. Prevalence of infection was lowest in May (27%) and highest in late summer and early autumn (71%). The prevalence of fleas also varied seasonally, and animals were more likely to have fleas in the late summer and early autumn than in early summer. We found no relationship between Bartonella prevalence and host density or flea prevalence.     

Trichinella papuae n.sp. (Nematoda), a new non-encapsulated species from domestic and sylvatic swine of Papua New Guinea

Encapsulated and non-encapsulated species of the genus Trichinella are widespread in sylvatic animals in almost all zoogeographical regions. In sylvatic animals from Tasmania (Australian region), only the non-encapsulated species Trichinella pseudospiralis has been reported. Between 1988 and 1998, non-encapsulated larvae of Trichinella were detected in five domestic pigs and six wild boars from a remote area of Papua New Guinea. Morphological, biological, and molecular studies carried out on one strain isolated from a wild boar in 1997 suggest that these parasites belong to a new species, which has been named Trichinella papuae n.sp. This species can be identified by the morphology of muscle larvae, which lack a nurse cell in host muscles, and whose total length is one-third greater than that of the other non-encapsulated species, T. pseudospiralis. Adults of T. papuae do not cross with adults of the other species and genotypes. Muscle larvae of T. papuae are unable to infect birds, whereas those of T. pseudospiralis do. The expansion segment V of the large subunit of the ribosomal DNA differs from that of the other species and genotypes. All of these features allow for the easy identification of T. papuae, even in poorly equipped laboratories. The discovery and identification of a second non-encapsulated species in the Australian region strongly supports the existence of two evolutionary lines in the genus Trichinella, which differ in terms of the capacity of larvae to induce a modification of the muscle cell into a nurse cell.     

A genetically homogenous population of Fusarium circinatum causes pitch canker of Pinus radiata in the Basque Country, Spain

Pitch canker, caused by Fusarium circinatum, is a destructive disease of Pinus species and has recently been shown to represent a substantial threat to natural and commercial forests in northern Spain. The genetic diversity of F. circinatum in the Basque Country of Spain was assessed by characterising 96 isolates based on vegetative compatibility groups (VCGs), mating type assays, polymorphic DNA-markers and amplified fragment length polymorphism (AFLP) analyses. For this purpose, F. circinatum isolates were collected from diseased Pinus radiata as well as from insects associated with this host. Overall, a low level of diversity was detected in the population. The isolates represented only two VCGs and they were all of the same mating type. AFLP analyses revealed three genotypes and polymorphic DNA-markers specific for F.?circinatum showed nine genotypes. The most common genotypes represented 97% of all isolates for AFLP analysis and 68% of isolates for the polymorphic DNA-marker sets. Over all, this indicates that pitch canker in the Basque Country of Spain is caused by a clonally propagating population of F. circinatum, typical of a recently introduced pathogen.