Genus Bartonella Research Articles

Infective endocarditis associated with Bartonella henselae: A case series.

Organisms in the genus Bartonella are cause of blood culture-negative endocarditis. Bartonella infective endocarditis is being increasingly reported worldwide; however, reports from Japan are limited. Here, we report five cases of infective endocarditis associated with Bartonella henselae. All patients had a history of contact with cats or fleas; this information helped achieve an appropriate diagnosis.

Origin and Evolution of the Bartonella Gene Transfer Agent.

Gene transfer agents (GTAs) are domesticated bacteriophages that have evolved into molecular machines for the transfer of bacterial DNA. Despite their widespread nature and their biological implications, the mechanisms and selective forces that drive the emergence of GTAs are still poorly understood. Two GTAs have been identified in the Alphaproteobacteria: the RcGTA, which is widely distributed in a broad range of species; and the BaGTA, which has a restricted host range that includes vector-borne intracellular bacteria of the genus Bartonella. The RcGTA packages chromosomal DNA randomly, whereas the BaGTA particles contain a relatively higher fraction of genes for host interaction factors that are amplified from a nearby phage-derived origin of replication. In this study, we compare the BaGTA genes with homologous bacteriophage genes identified in the genomes of Bartonella species and close relatives. Unlike the BaGTA, the prophage genes are neither present in all species, nor inserted into homologous genomic sites. Phylogenetic inferences and substitution frequency analyses confirm codivergence of the BaGTA with the host genome, as opposed to multiple integration and recombination events in the prophages. Furthermore, the organization of segments flanking the BaGTA differs from that of the prophages by a few rearrangement events, which have abolished the normal coordination between phage genome replication and phage gene expression. Based on the results of our comparative analysis, we propose a model for how a prophage may be transformed into a GTA that transfers amplified bacterial DNA segments.

Prevalence of Bartonella spp. by culture, PCR and serology, in veterinary personnel from Spain

BackgroundThe genus Bartonella includes fastidious, facultative intracellular bacteria mainly transmitted by arthropods and distributed among mammalian reservoirs. Bartonella spp. implicated as etiological agents of zoonoses are increasing. Apart from the classical Bartonella henselae, B. bacilliformis or B. quintana, other species (B. elizabethae, B. rochalimae, B. vinsonii arupensis and B. v. berkhoffii, B. tamiae or B. koehlerae, among others) have also been associated with human and/or animal diseases. Laboratory techniques for diagnosis (culture, PCR assays and serology) usually show lack of sensitivity. Since 2005, a method based on a liquid enrichment Bartonella alphaproteobacteria growth medium (BAPGM) followed by PCRs for the amplification of Bartonella spp. has been developed. We aimed to assess culture, molecular and serological prevalence of Bartonella infections in companion animal veterinary personnel from Spain.MethodsEach of 89 participants completed a questionnaire. Immunofluorescence assays (IFA) using B. vinsonii berkhoffii (genotypes I, II and III), B. henselae, B. quintana and B. koehlerae as antigens were performed. A cut-off of 1:64 was selected as a seroreactivity titer. Blood samples were inoculated into BAPGM and subcultured onto blood agar plates. Bartonella spp. was detected using conventional and quantitative real-time PCR assays and DNA sequencing.ResultsAmong antigens corresponding to six Bartonella spp. or genotypes, the lowest seroreactivity was found against B. quintana (11.2%) and the highest, against B. v. berkhoffii genotype III (56%). A total of 27% of 89 individuals were not seroreactive to any test antigen. Bartonella spp. IFA seroreactivity was not associated with any clinical sign or symptom. DNA from Bartonella spp., including B. henselae (n = 2), B. v. berkhoffii genotypes I (n = 1) and III (n = 2), and B. quintana (n = 2) was detected in 7/89 veterinary personnel. PCR and DNA sequencing findings were not associated with clinical signs or symptoms. No co-infections were observed. One of the two B. henselae PCR-positive individuals was IFA seronegative to all tested antigens whereas the other one was not B. henselae seroreactive. The remaining PCR-positive individuals were seroreactive to multiple Bartonella spp. antigens.ConclusionsHigh serological and molecular prevalences of exposure to, or infection with, Bartonella spp. were found in companion animal veterinary personnel from Spain. More studies using BAPGM enrichment blood culture and PCR are needed to clarify the finding of Bartonella PCR-positive individuals lacking clinical symptoms.

Molecular detection of Bartonella spp. in deer ked (Lipoptena cervi) in Poland

BackgroundThe bacteria of the genus Bartonella are obligate parasites of vertebrates. Their distribution range covers almost the entire world from America, Europe, Asia to Africa and Australia. Some species of Bartonella are pathogenic for humans. Their main vectors are blood-sucking arthropods such as fleas, ticks and blood-feeding flies. One such dipteran able to transfer vector-borne pathogens is the deer ked (Lipoptena cervi) of the family Hippoboscidae. This species acts as a transmitter of Bartonella spp. in cervid hosts in Europe.MethodsIn the present study, 217 specimens of deer ked (Lipoptena cervi) were collected from 26 red deer (Cervus elaphus) hunted in January 2014. A short fragment (333 bp) of the rpoB gene was used as a marker to identify Bartonella spp. in deer ked tissue by PCR test. A longer fragment (850 bp) of the rpoB gene was amplified from 21 of the positive samples, sequenced and used for phylogenetic analysis.ResultsThe overall prevalence of Lipoptena cervi infection with Bartonella spp. was 75.12% (163/217); 86.67% (104/120) of females and 60.82% (59/97) of males collected from red deer hunted in the Strzałowo Forest District in Poland (53°45′57.03″N, 21°25′17.79″E) were infected. The nucleotide sequences from 14 isolates (Bartonella sp. 1) showed close similarity to Bartonella schoenbuchensis isolated from moose blood from Sweden (GenBank: KB915628) and human blood from France (GenBank: HG977196); Bartonella sp. 2 (5 isolates) and Bartonella sp. 3 (one isolate) were similar to Bartonella sp. from Japanese sika deer (GenBank: AB703149), and Bartonella sp. 4 (one isolate) was almost identical to Bartonella sp. isolated from Japanese sika deer from Japan (GenBank: AB703146).ConclusionsTo the best of our knowledge, this is the first report to confirm the presence of Bartonella spp. in deer keds (Lipoptena cervi) in Poland by molecular methods. Bartonella sp. 1 isolates were most closely related to B. schoenbuchensis isolated from moose from Sweden and human blood from France. The rest of our isolates (Bartonella spp. 2–4) were similar to Bartonella spp. isolated from Japanese sika deer from Japan.

First molecular detection and characterization of zoonotic Bartonella species in fleas infesting domestic animals in Tunisia

BackgroundBartonellosis is an emerging vector-borne disease caused by different intracellular bacteria of the genus Bartonella (Rhizobiales: Bartonellaceae) that is transmitted primarily by blood-sucking arthropods such as sandflies, ticks and fleas. In Tunisia, there are no data available identifying the vectors of Bartonella spp. In our research, we used molecular methods to detect and characterize Bartonella species circulating in fleas collected from domestic animals in several of the country’s bioclimatic areas.ResultsA total of 2178 fleas were collected from 5 cats, 27 dogs, 34 sheep, and 41 goats at 22 sites located in Tunisia’s five bioclimatic zones. The fleas were identified as: 1803 Ctenocephalides felis (83%) (Siphonaptera: Pulicidae), 266 C. canis (12%) and 109 Pulex irritans (5%) (Siphonaptera: Pulicidae). Using conventional PCR, we screened the fleas for the presence of Bartonella spp., targeting the citrate synthase gene (gltA). Bartonella DNA was detected in 14% (121/866) of the tested flea pools [estimated infection rate (EIR) per 2 specimens: 0.072, 95% confidence interval (CI): 0.060–0.086]. The Bartonella infection rate per pool was broken down as follows: 55% (65/118; EIR per 2 specimens: 0.329, 95% CI: 0.262–0.402) in C. canis; 23.5% (8/34; EIR per 2 specimens: 0.125, 95% CI: 0.055–0.233) in P. irritans and 6.7% (48/714; EIR per 2 specimens: 0.032, 95% CI: 0.025–0.045) in C. felis. Infection rates, which varied significantly by bioclimatic zone (P < 0.0001), were highest in the humid areas. By sequencing, targeting the gltA gene and the 16S–23S rRNA Intergenic Spacer Regions (ITS), we identified three Bartonella zoonotic species: B. elizabethae, B. henselae, B. clarridgeiae, as well as uncharacterized Bartonella genotypes.ConclusionsTo the best of our knowledge, this is the first time that fleas in Tunisia have been shown to carry zoonotic species of Bartonella. The dog flea, Ctenocephalides canis, should be considered the main potential vector of Bartonella. Our study not only provides new information about this vector, but also offers a public health update: medical practitioners and farmers in Tunisia should be apprised of the presence of Bartonella in fleas and implement preventive measures.

Bartonella in Rodents and Ectoparasites in the Canary Islands, Spain: New Insights into Host-Vector-Pathogen Relationships.

Bartonella genus is comprised of several species of zoonotic relevance and rodents are reservoirs for some of these Bartonella species. As there were no data about the range of Bartonella species circulating among rodents in the Canary Islands, our main aim was to overcome this lack of knowledge by targeting both the citrate synthase (gltA) and the RNA polymerase beta subunit (rpoB) genes. A total of 181 small mammals and 154 ectoparasites were obtained in three of the Canary Islands, namely Tenerife, La Palma, and Lanzarote. The overall prevalence of Bartonella DNA in rodents was 18.8%, whereas the prevalence in ectoparasites was 13.6%. Bartonella sequences closely related to the zoonotic species Bartonella elizabethae, Bartonella tribocorum, and Bartonella rochalimae were identified in rodents, whereas two different gltA haplotypes similar to B. elizabethae were also detected in fleas. Furthermore, Bartonella queenslandensis DNA was also identified in rodents. A strong host specificity was observed, since B. elizabethae DNA was only found in Mus musculus domesticus, whereas gltA and rpoB sequences closely related to the rest of Bartonella species were only identified in Rattus rattus, which is probably due to the host specificity of the arthropod species that act as vectors in these islands. Our results indicate that humans may contract Bartonella infection by contact with rodents in the Canary Islands.

Comparison of Microbiomes between Red Poultry Mite Populations (Dermanyssus gallinae): Predominance of Bartonella-like Bacteria.

Blood feeding red poultry mites (RPM) serve as vectors of pathogenic bacteria and viruses among vertebrate hosts including wild birds, poultry hens, mammals, and humans. The microbiome of RPM has not yet been studied by high-throughput sequencing. RPM eggs, larvae, and engorged adult/nymph samples obtained in four poultry houses in Czechia were used for microbiome analyses by Illumina amplicon sequencing of the 16S ribosomal RNA (rRNA) gene V4 region. A laboratory RPM population was used as positive control for transcriptome analysis by pyrosequencing with identification of sequences originating from bacteria. The samples of engorged adult/nymph stages had 100-fold more copies of 16S rRNA gene copies than the samples of eggs and larvae. The microbiome composition showed differences among the four poultry houses and among observed developmental stadia. In the adults' microbiome 10 OTUs comprised 90 to 99% of all sequences. Bartonella-like bacteria covered between 30 and 70% of sequences in RPM microbiome and 25% bacterial sequences in transcriptome. The phylogenetic analyses of 16S rRNA gene sequences revealed two distinct groups of Bartonella-like bacteria forming sister groups: (i) symbionts of ants; (ii) Bartonella genus. Cardinium, Wolbachia, and Rickettsiella sp. were found in the microbiomes of all tested stadia, while Spiroplasma eriocheiris and Wolbachia were identified in the laboratory RPM transcriptome. The microbiomes from eggs, larvae, and engorged adults/nymphs differed. Bartonella-like symbionts were found in all stadia and sampling sites. Bartonella-like bacteria was the most diversified group within the RPM microbiome. The presence of identified putative pathogenic bacteria is relevant with respect to human and animal health issues while the identification of symbiontic bacteria can lead to new control methods targeting them to destabilize the arthropod host.

Bartonella Species, an Emerging Cause of Blood-Culture-Negative Endocarditis.

Since the reclassification of the genus Bartonella in 1993, the number of species has grown from 1 to 45 currently designated members. Likewise, the association of different Bartonella species with human disease continues to grow, as does the range of clinical presentations associated with these bacteria. Among these, blood-culture-negative endocarditis stands out as a common, often undiagnosed, clinical presentation of infection with several different Bartonella species. The limitations of laboratory tests resulting in this underdiagnosis of Bartonella endocarditis are discussed. The varied clinical picture of Bartonella infection and a review of clinical aspects of endocarditis caused by Bartonella are presented. We also summarize the current knowledge of the molecular basis of Bartonella pathogenesis, focusing on surface adhesins in the two Bartonella species that most commonly cause endocarditis, B. henselae and B. quintana. We discuss evidence that surface adhesins are important factors for autoaggregation and biofilm formation by Bartonella species. Finally, we propose that biofilm formation is a critical step in the formation of vegetative masses during Bartonella-mediated endocarditis and represents a potential reservoir for persistence by these bacteria.

Neorickettsia risticii, Rickettsia sp. and Bartonella sp. in Tadarida brasiliensis bats from Buenos Aires, Argentina.

Bats are potential reservoirs of many vector-borne bacterial pathogens. The aim of the present study was to detect species of Anaplasma, Ehrlichia, Neorickettsia, Rickettsia, Borrelia and Bartonella in Brazilian free-tailed bats (Tadarida brasiliensis, Molossidae) from Buenos Aires city, Argentina. Between 2012 and 2013, 61 T. brasiliensis from urban areas of Buenos Aires city were studied. The samples were molecularly screened by PCR and sequencing. Five bats (8.2%) were positive to Neorickettsia risticii, one (1.6%) was positive to Rickettsia sp. and three bats (4.9%) to Bartonella sp. For molecular characterization, the positive samples were subjected to amplification and sequencing of a fragment of p51 gene for N. risticii, a fragment of citrate synthase gene (gltA) for Rickettsia genus and a fragment of gltA for Bartonella genus. Phylogenetic tree was constructed using the maximum-likelihood method. Phylogenetic analysis of N. risticii detect in our study revealed that it relates to findings in the USA West Coast; Rickettsia sp. detected is phylogenetically within R. bellii group, which also includes many other Rickettsia endosymbionts of insects; and Bartonella sp. found is related to various Bartonella spp. described in Vespertilionidae bats, which are phylogenetically related to Molossidae. Our results are in accordance to previous findings, which demonstrate that insectivorous bats could be infected with vector-borne bacteria representing a potential risk to public health. Future research is necessary to clarify the circulation of these pathogens in bats from Buenos Aires.

Whole-Genome Analysis ofBartonellaancashensis, a Novel Pathogen Causing Verruga Peruana, Rural Ancash Region, Peru

The genus Bartonella contains >40 species, and an increasing number of these Bartonella species are being implicated in human disease. One such pathogen is Bartonella ancashensis, which was isolated in blood samples from 2 patients living in Caraz, Peru, during a clinical trial of treatment for bartonellosis. Three B. ancashensis strains were analyzed by using whole-genome restriction mapping and high-throughput pyrosequencing. Genome-wide comparative analysis of Bartonella species showed that B. ancashensis has features seen in modern and ancient lineages of Bartonella species and is more related to B. bacilliformis. The divergence between B. ancashensis and B. bacilliformis is much greater than what is seen between known Bartonella genetic lineages. In addition, B. ancashensis contains type IV secretion system proteins, which are not present in B. bacilliformis. Whole-genome analysis indicates that B. ancashensis might represent a distinct Bartonella lineage phylogenetically related to B. bacilliformis.

Evolutionary Dynamics of Pathoadaptation Revealed by Three Independent Acquisitions of the VirB/D4 Type IV Secretion System in Bartonella.

The α-proteobacterial genus Bartonella comprises a group of ubiquitous mammalian pathogens that are studied as a model for the evolution of bacterial pathogenesis. Vast abundance of two particular phylogenetic lineages of Bartonella had been linked to enhanced host adaptability enabled by lineage-specific acquisition of a VirB/D4 type IV secretion system (T4SS) and parallel evolution of complex effector repertoires. However, the limited availability of genome sequences from one of those lineages as well as other, remote branches of Bartonella has so far hampered comprehensive understanding of how the VirB/D4 T4SS and its effectors called Beps have shaped Bartonella evolution. Here, we report the discovery of a third repertoire of Beps associated with the VirB/D4 T4SS of B. ancashensis, a novel human pathogen that lacks any signs of host adaptability and is only distantly related to the two species-rich lineages encoding a VirB/D4 T4SS. Furthermore, sequencing of ten new Bartonella isolates from under-sampled lineages enabled combined in silico analyses and wet lab experiments that suggest several parallel layers of functional diversification during evolution of the three Bep repertoires from a single ancestral effector. Our analyses show that the Beps of B. ancashensis share many features with the two other repertoires, but may represent a more ancestral state that has not yet unleashed the adaptive potential of such an effector set. We anticipate that the effectors of B. ancashensis will enable future studies to dissect the evolutionary history of Bartonella effectors and help unraveling the evolutionary forces underlying bacterial host adaptation.

Genomic changes associated with the evolutionary transition of an insect gut symbiont into a blood-borne pathogen

The genus Bartonella comprises facultative intracellular bacteria with a unique lifestyle. After transmission by blood-sucking arthropods they colonize the erythrocytes of mammalian hosts causing acute and chronic infectious diseases. Although the pathogen–host interaction is well understood, little is known about the evolutionary origin of the infection strategy manifested by Bartonella species. Here we analyzed six genomes of Bartonella apis, a honey bee gut symbiont that to date represents the closest relative of pathogenic Bartonella species. Comparative genomics revealed that B. apis encodes a large set of vertically inherited genes for amino acid and cofactor biosynthesis and nitrogen metabolism. Most pathogenic bartonellae have lost these ancestral functions, but acquired specific virulence factors and expanded a vertically inherited gene family for harvesting cofactors from the blood. However, the deeply rooted pathogen Bartonella tamiae has retained many of the ancestral genome characteristics reflecting an evolutionary intermediate state toward a host-restricted intraerythrocytic lifestyle. Our findings suggest that the ancestor of the pathogen Bartonella was a gut symbiont of insects and that the adaptation to blood-feeding insects facilitated colonization of the mammalian bloodstream. This study highlights the importance of comparative genomics among pathogens and non-pathogenic relatives to understand disease emergence within an evolutionary-ecological framework.

The genome of Rhizobiales bacteria in predatory ants reveals urease gene functions but no genes for nitrogen fixation.

Gut-associated microbiota of ants include Rhizobiales bacteria with affiliation to the genus Bartonella. These bacteria may enable the ants to fix atmospheric nitrogen, but no genomes have been sequenced yet to test the hypothesis. Sequence reads from a member of the Rhizobiales were identified in the data collected in a genome project of the ant Harpegnathos saltator. We present an analysis of the closed 1.86 Mb genome of the ant-associated bacterium, for which we suggest the species name Candidatus Tokpelaia hoelldoblerii. A phylogenetic analysis reveals a relationship to Bartonella and Brucella, which infect mammals. Novel gene acquisitions include a gene for a putative extracellular protein of more than 6,000 amino acids secreted by the type I secretion system, which may be involved in attachment to the gut epithelium. No genes for nitrogen fixation could be identified, but genes for a multi-subunit urease protein complex are present in the genome. The urease genes are also present in Brucella, which has a fecal-oral transmission pathway, but not in Bartonella, which use blood-borne transmission pathways. We hypothesize that the gain and loss of the urease function is related to transmission strategies and lifestyle changes in the host-associated members of the Rhizobiales.

A family of genus-specific RNAs in tandem with DNA-binding proteins control expression of the badA major virulence factor gene in Bartonella henselae.

Bartonella henselae is a gram‐negative zoonotic bacterium that causes infections in humans including endocarditis and bacillary angiomatosis. B. henselae has been shown to grow as large aggregates and form biofilms in vitro. The aggregative growth and the angiogenic host response requires the trimeric autotransporter adhesin BadA. We examined the transcriptome of the Houston‐1 strain of B. henselae using RNA‐seq revealing nine novel, highly‐expressed intergenic transcripts (Bartonella regulatory transcript, Brt1‐9). The Brt family of RNAs is unique to the genus Bartonella and ranges from 194 to 203 nucleotides with high homology and stable predicted secondary structures. Immediately downstream of each of the nine RNA genes is a helix‐turn‐helix DNA‐binding protein (transcriptional regulatory protein, Trp1‐9) that is poorly transcribed under the growth conditions used for RNA‐seq. Using knockdown or overexpressing strains, we show a role of both the Brt1 and Trp1 in the regulation of badA and also in biofilm formation. Based on these data, we hypothesize that Brt1 is a trans‐acting sRNA that also serves as a cis‐acting riboswitch to control the expression of badA. This family of RNAs together with the downstream Trp DNA‐binding proteins represents a novel coordinated regulatory circuit controlling expression of virulence‐associated genes in the bartonellae.

Identification and functional analysis of invasion associated locus B (IalB) in Bartonella species

Bartonellosis is caused by the genus Bartonella. Bartonella is widely distributed in the ruminants, cats, dogs, rodents and other mammals including humans. At least 13 species or subspecies of Bartonella are zoonotic, and each species appears to be highly adapted to one or a limited number of reservoir animals in which it is asymptomatic, while it can be transmitted to humans in which a variety of clinical manifestations can be caused. It was reported that Bartonella henselae infection rate among domestic cats was high in nature, making it one of the leading, important, and easily neglected zoonotic diseases. The aims of this study were to identify the expression, localization, immunogenicity and functional mechanism of Bartonella virulence factor IalB. We found that recombinant IalB protein could react with the serum from infected reservoir hosts and anti-IalB polyclonal antibodies could react with different Bartonella species by western blot analysis. According to these results, we proposed that IalB protein and anti-IalB antibodies would be good candidates for diagnosis of Bartonella infection by antigen-based anti-IalB antibodies or antibody-based IalB antigen capture immunoassay, respectively. We also found that IalB had a putative 22-amino-acid signal sequence and little IalB was localized to the outer membrane of Bartonella birtlesii by electron microscopy assay. Incubation with anti-IalB polyclonal antibodies resulted in inhibition of the invasion of mouse erythrocytes by B. birtlesii. According to these results, we propose that IalB could be a secreted protein that facilitates Bartonella entry into erythrocytes. In conclusion, these results improve our understanding of IalB as a candidate for immunodiagnosis and how IalB affects Bartonella-erythrocyte entry.

Phylogenetic and geographic patterns of bartonella host shifts among bat species

The influence of factors contributing to parasite diversity in individual hosts and communities are increasingly studied, but there has been less focus on the dominant processes leading to parasite diversification. Using bartonella infections in bats as a model system, we explored the influence of three processes that can contribute to bartonella diversification and lineage formation: (1) spatial correlation in the invasion and transmission of bartonella among bats (phylogeography); (2) divergent adaptation of bartonellae to bat hosts and arthropod vectors; and (3) evolutionary codivergence between bats and bartonellae. Using a combination of global fit techniques and ancestral state reconstruction, we found that codivergence appears to be the dominant process leading to diversification of bartonella in bats, with lineages of bartonellae corresponding to separate bat suborders, superfamilies, and families. Furthermore, we estimated the rates at which bartonellae shift bat hosts across taxonomic scales (suborders, superfamilies, and families) and found that transition rates decrease with increasing taxonomic distance, providing support for a mechanism that can contribute to the observed evolutionary congruence between bats and their associated bartonellae. While bartonella diversification is associated with host sympatry, the influence of this factor is minor compared to the influence of codivergence and there is a clear indication that some bartonella lineages span multiple regions, particularly between Africa and Southeast Asia. Divergent adaptation of bartonellae to bat hosts and arthropod vectors is apparent and can dilute the overall pattern of codivergence, however its importance in the formation of Bartonella lineages in bats is small relative to codivergence. We argue that exploring all three of these processes yields a more complete understanding of bat-bartonella relationships and the evolution of the genus Bartonella, generally. Application of these methods to other infectious bacteria and viruses could uncover common processes that lead to parasite diversification and the formation of host-parasite relationships.

Bartonella spp. - a chance to establish One Health concepts in veterinary and human medicine.

Infectious diseases remain a remarkable health threat for humans and animals. In the past, the epidemiology, etiology and pathology of infectious agents affecting humans and animals have mostly been investigated in separate studies. However, it is evident, that combined approaches are needed to understand geographical distribution, transmission and infection biology of “zoonotic agents”. The genus Bartonella represents a congenial example of the synergistic benefits that can arise from such combined approaches: Bartonella spp. infect a broad variety of animals, are linked with a constantly increasing number of human diseases and are transmitted via arthropod vectors. As a result, the genus Bartonella is predestined to play a pivotal role in establishing a One Health concept combining veterinary and human medicine.

Risk Factors for Bartonella species Infection in Blood Donors from Southeast Brazil.

Bacteria from the genus Bartonella are emerging blood-borne bacteria, capable of causing long-lasting infection in marine and terrestrial mammals, including humans. Bartonella are generally well adapted to their main host, causing persistent infection without clinical manifestation. However, these organisms may cause severe disease in natural or accidental hosts. In humans, Bartonella species have been detected from sick patients presented with diverse disease manifestations, including cat scratch disease, trench fever, bacillary angiomatosis, endocarditis, polyarthritis, or granulomatous inflammatory disease. However, with the advances in diagnostic methods, subclinical bloodstream infection in humans has been reported, with the potential for transmission through blood transfusion been recently investigated by our group. The objective of this study was to determine the risk factors associated with Bartonella species infection in asymptomatic blood donors presented at a major blood bank in Southeastern Brazil. Five hundred blood donors were randomly enrolled and tested for Bartonella species infection by specialized blood cultured coupled with high-sensitive PCR assays. Epidemiological questionnaires were designed to cover major potential risk factors, such as age, gender, ethnicity, contact with companion animals, livestock, or wild animals, bites from insects or animal, economical status, among other factors. Based on multivariate logistic regression, bloodstream infection with B. henselae or B. clarridgeiae was associated with cat contact (adjusted OR: 3.4, 95% CI: 1.1–9.6) or history of tick bite (adjusted OR: 3.7, 95% CI: 1.3–13.4). These risk factors should be considered during donor screening, as bacteremia by these Bartonella species may not be detected by traditional laboratory screening methods, and it may be transmitted by blood transfusion.

GEOGRAPHIC DISTRIBUTION AND MOLECULAR DIVERSITY OF BARTONELLA SPP. INFECTIONS IN MOOSE (ALCES ALCES) IN FINLAND.

Moose, Alces alces (Artiodactyla: Cervidae) in Finland are heavily infested with deer keds, Lipoptena cervi (Diptera: Hippoboschidae). The deer ked, which carries species of the genus Bartonella, has been proposed as a vector for the transmission of bartonellae to animals and humans. Previously, bartonella DNA was found in deer keds as well as in moose blood collected in Finland. We investigated the prevalence and molecular diversity of Bartonella spp. infection from blood samples collected from free-ranging moose. Given that the deer ked is not present in northernmost Finland, we also investigated whether there were geographic differences in the prevalence of bartonella infection in moose. The overall prevalence of bartonella infection was 72.9% (108/148). Geographically, the prevalence was highest in the south (90.6%) and lowest in the north (55.9%). At least two species of bartonellae were identified by multilocus sequence analysis. Based on logistic regression analysis, there was no significant association between bartonella infection and either age or sex; however, moose from outside the deer ked zone were significantly less likely to be infected (P<0.015) than were moose hunted within the deer ked zone.

Bartonella Species Identified in Rodent and Feline Hosts from Island and Mainland Western Australia.

Bacteria of the genus Bartonella have been described in multiple mammalian hosts with many species capable of causing disease in humans. Cats and various species of rats have been reported to play a role as vertebrate hosts to a number of Bartonella spp. This study aimed to identify Bartonella spp. in Western Australia, Dirk Hartog Island (DHI), and Christmas Island (CI) and to investigate the presence of potential arthropod vectors. Feral cats were collected from CI (n = 35), DHI (n = 23) and southwest Western Australia (swWA; n = 58), and black rats were collected from CI (n = 48). Individuals were necropsied, ectoparasites were collected by external examination of carcasses, and splenic tissue was collected for polymerase chain reaction analysis to detect Bartonella DNA. Bartonella henselae DNA was detected from two cats and Bartonella koehlerae DNA from one cat in southwest WA, but Bartonella DNA was not identified in cats on DHI or CI. Bartonella phoceensis (28/48 = 58.3%) and a novel Bartonella genotype (8/48 = 16.7%) based on the internal transcribed space region were detected in the spleens of black rats on CI. Detection of Bartonella spp. in each location corresponded to the presence of ectoparasites. Cats from southwest WA harbored four species of fleas, including Ctenocephalides felis, and black rats on CI were infested with multiple species of ectoparasites, including mites, fleas, and lice. Conversely, cats on Dirk Hartog and CI were free of ectoparasites. This study has identified the DNA of Bartonella species from island and mainland swWA with some (B. henselae and B. koehlerae) of known zoonotic importance. This study further extends the geographical range for the pathogenic B. koehlerae. The association of Bartonella with ectoparasites is unsurprising, but little is known about the specific vector competence of the ectoparasites identified in this study.