Endocarditis in cattle caused by Bartonella bovis

Bartonella species in dromedaries and ruminants from Lower Shabelle and Benadir regions, Somalia

BACKGROUND

Bartonellosis, caused by bacteria of the genus Bartonella, is a zoonotic disease with several mammalian reservoir hosts. In Somalia, a country heavily reliant on livestock, zoonotic diseases pose significant public health and economic challenges. To the best of our knowledge, no study has been performed aiming to verify the occurrence of Bartonella spp. in Somalia. This study investigated the occurrence and molecular characterization of Bartonella in dromedary (Camelus dromedarius, Linnaeus, 1758), cattle, sheep, and goats from Somalia.

MATERIALS AND METHODS

530 blood samples were collected from various animals (155 dromedary, 199 goat, 131 cattle, and 45 sheep) in Benadir and Lower Shabelle regions. DNA was extracted for molecular analysis, and a qPCR assay targeting the NADH dehydrogenase gamma subunit (nuoG) gene was used for Bartonella screening. Positive samples were also subjected to PCR assays targeting seven molecular markers including: nuoG, citrate synthase gene (gltA), RNA polymerase beta-subunit gene (rpoB), riboflavin synthase gene (ribC), 60 kDa heat-shock protein gene (groEL), cell division protein gene (ftsZ), and pap31 and qPCR targeting the 16-23S rRNA internal transcribed spacer (ITS) followed by Sanger sequencing, BLASTn and phylogenetic analysis.

RESULTS

Out of 530 tested animals, 5.1% were positive for Bartonella spp. by the nuoG qPCR assay. Goats showed the highest Bartonella occurrence (17/199, 8.5%), followed by sheep (6/44, 6.8%), cattle (4/131, 3.1%), and dromedary (1/155, 1.9%). Goats, sheep, and cattle had higher odds of infection compared to dromedary. Among nuoG qPCR-positive samples, 11.1%, 14.8%, 11.1%, and 25.9% were positive in PCR assays based on nuoG, gltA, and pap31 genes, and in the qPCR based on the ITS region, respectively. On the other hand, nuoG qPCR-positive samples were negative in the PCR assays targeting the ribC, rpoB, ftsZ, and groEL genes. While Bartonella bovis sequences were detected in cattle (nuoG and ITS) and goats (gltA), Bartonella henselae ITS sequences were detected in dromedary, goat, and sheep. Phylogenetic analysis placed gltA Bartonella sequence from a goat in the same clade of B. bovis.

CONCLUSION

The present study showed, for the first time, molecular evidence of Bartonella spp. in dromedary and ruminants from Somalia and B. henselae in sheep and goats globally. These findings contribute valuable insights into Bartonella spp. occurrence in Somali livestock, highlighting the need for comprehensive surveillance and control measures under the One Health approach.

Geographical distribution of Bartonella spp in the countries of the WHO Eastern Mediterranean Region (WHO-EMRO)

Bartonellosis is a vector-borne and zoonotic diseases in humans, especially in immunocompromised individuals. However, there is no complete data about the geographical distribution of different species of Bartonella, as well as the status of its reservoirs, vectors, and human cases in most parts of the world. In this study, published reports related to Bartonella species from WHO-EMRO region countries were searched in different databases until October 2023. The eighteens different species of Bartonella were reported in WHO-EMRO countries including Bartonella henselae, Bartonella quintana, Bartonella elizabethae, Bartonella bovis, Bartonella clarridgeiae, Bartonella vinsonii, Bartonella doshiae, Bartonella taylorii, Bartonella rochalimae, Bartonella tribocorum, Bartonella rattimassiliensis, candidatus Bartonella merieuxii, candidatus Bartonella dromedarii, Bartonella acomydis, Bartonella jaculi, Bartonella coopersplainsensis and Bartonella koehlerae. Also, only human cases of B. henselae and B. quintana infections were reported from WHO-EMRO countries. The infections of Bartonella are important in the WHO-EMRO region, but they have been neglected by clinicians and healthcare systems.

Analysis of the bacterial community in female Rhipicephalus microplus ticks from selected provinces in Luzon, Philippines, using next-generation sequencing

Analysis of the tick microbiome can help understand tick-symbiont interactions and identify undiscovered pathogens, which may aid in implementing control of ticks and tick-borne diseases. The tropical cattle tick Rhipicephalus microplus is a widespread ectoparasite of cattle in the Philippines, negatively affecting animal productivity and health. This study characterized the bacterial community of R. microplus from Luzon, Philippines, through next-generation sequencing of 16s rRNA. DNA was extracted from 45 partially engorged female ticks from nine provinces. The DNA samples were pooled per province and then sequenced and analyzed using an open-source bioinformatics platform. In total, 667 operational taxonomic units (OTUs) were identified. The ticks in all nine provinces were found to have Coxiella, Corynebacterium, Staphylococcus, and Acinetobacter. Basic local alignment search tool (BLAST) analysis revealed the presence of known pathogens of cattle, such as Bartonella, Ehrlichia minasensis, and Dermatophilus congolensis. The tick samples from Laguna, Quezon, and Batangas had the most diverse bacterial species, whereas the tick samples from Ilocos Norte had the lowest diversity. Similarities in the composition of the bacterial community in ticks from provinces near each other were also observed. This is the first study on metagenomic analysis of cattle ticks in the Philippines, providing new insights that may be useful for controlling ticks and tick-borne diseases.

Molecular pathogen screening of louse flies (Diptera: Hippoboscidae) from domestic and wild ruminants in Austria

BACKGROUND

Hippoboscid flies (Diptera: Hippoboscidae), also known as louse flies or keds, are obligate blood-sucking ectoparasites of animals, and accidentally of humans. The potential role of hippoboscids as vectors of human and veterinary pathogens is being increasingly investigated, but the presence and distribution of infectious agents in louse flies is still unknown in parts of Europe. Here, we report the use of molecular genetics to detect and characterize vector-borne pathogens in hippoboscid flies infesting domestic and wild animals in Austria.

METHODS

Louse flies were collected from naturally infested cattle (n = 25), sheep (n = 3), and red deer (n = 12) across Austria between 2015 and 2019. Individual insects were morphologically identified to species level and subjected to DNA extraction for molecular pathogen screening and barcoding. Genomic DNA from each louse fly was screened for Borrelia spp., Bartonella spp., Trypanosomatida, Anaplasmataceae, Filarioidea and Piroplasmida. Obtained sequences of Trypanosomatida and Bartonella spp. were further characterized by phylogenetic and haplotype networking analyses.

RESULTS

A total of 282 hippoboscid flies corresponding to three species were identified: Hippobosca equina (n = 62) collected from cattle, Melophagus ovinus (n = 100) from sheep and Lipoptena cervi (n = 120) from red deer (Cervus elaphus). Molecular screening revealed pathogen DNA in 54.3% of hippoboscids, including infections with single (63.39%), two (30.71%) and up to three (5.90%) distinct pathogens in the same individual. Bartonella DNA was detected in 36.9% of the louse flies. Lipoptena cervi were infected with 10 distinct and previously unreported Bartonella sp. haplotypes, some closely associated with strains of zoonotic potential. DNA of trypanosomatids was identified in 34% of hippoboscids, including the first description of Trypanosoma sp. in H. equina. Anaplasmataceae DNA (Wolbachia spp.) was detected only in M. ovinus (16%), while < 1% of the louse flies were positive for Borrelia spp. and Filarioidea. All hippoboscids were negative for Piroplasmida.

CONCLUSIONS

Molecular genetic screening confirmed the presence of several pathogens in hippoboscids infesting domestic and wild ruminants in Austria, including novel pathogen haplotypes of zoonotic potential (e.g. Bartonella spp.) and the first report of Trypanosoma sp. in H. equina, suggesting a potential role of this louse fly as vector of animal trypanosomatids. Experimental transmission studies and expanded monitoring of hippoboscid flies and hippoboscid-associated pathogens are warranted to clarify the competence of these ectoparasites as vectors of infectious agents in a One-Health context.

First Molecular Detection of Bartonella bovis and Bartonella schoenbuchensis in European Bison (Bison bonasus)

Bartonella bacteria infect the erythrocytes and endothelial cells of mammalians. The spread of the Bartonella infection occurs mainly via bloodsucking arthropod vectors. Studies on Bartonella infection in European bison, the largest wild ruminant in Europe, are lacking. They are needed to clarify their role in the maintenance and transmission of Bartonella spp. The aim of this study was to investigate the presence of the Bartonella pathogen in European bison and their ticks in Lithuania. A total of 38 spleen samples from bison and 258 ticks belonging to the Ixodes ricinus and Dermacentor reticulatus species were examined. The bison and tick samples were subjected to ssrA, 16S-23S rRNA ITS, gltA, and rpoB partial gene fragment amplification using various variants of PCR. Bartonella DNA was detected in 7.9% of the tissue samples of European bison. All tick samples were negative for Bartonella spp. The phylogenetic analysis of 16S-23S rRNA ITS, gltA, and rpoB partial gene fragment revealed that European bison were infected by B. bovis (2.6%) and B. schoenbuchensis (5.3%). This is the first report addressing the occurrence of B. bovis and B. schoenbuchensis in European bison in Europe.

A Review of Bartonella Infections in California-Implications for Public and Veterinary Health

Bartonella are vector-transmitted, intracellular bacteria that infect a wide variety of blood-feeding arthropods and their vertebrate hosts. In California, more than 13 species of Bartonella have been described from companion animals, livestock, and wildlife, of which four have been associated with human disease. Infections in humans cause a range of symptoms from relatively mild to severe, especially in immunocompromised individuals. Exposure to infected domestic animals and wildlife, and their ectoparasites, may increase the risk of cross-species transmission. The objective of this review was to compile and summarize published materials on human and animal Bartonella infections in California. Medical and veterinary case reports of bartonellosis were highlighted in an effort to increase the awareness of this poorly understood and potentially under-recognized disease among healthcare professionals and veterinarians.

Tracking tick-borne diseases in Mongolian livestock using next generation sequencing (NGS)

The livestock industry in Mongolia accounts for 24% of national revenue, with one third of the population maintaining a pastoral lifestyle. This close connection between Mongolian population and livestock is a major concern for pathogen transfer, especially given the increase in vector-borne diseases globally. This study examines blood samples from livestock to assess the prevalence of tick-borne bacterial infections across three provinces in Mongolia (Dornogovi, Selenge, Töv). Whole blood samples from 243 livestock (cattle=38, camel=11, goat=85, horse=22, sheep=87) were analyzed with 16S metagenomics next-generation sequencing (NGS) to screen for bacterial pathogens. Positive-NGS samples for Anaplasma, Bartonella, Ehrlichia, Francisella, Leptospira, and Rickettsia were confirmed by conventional PCR and DNA sequencing. Prevalence rates of Anaplasma, Bartonella, and Ehrlichia were 57.6%, 12.8%, and 0.4%, respectively. A significant difference in the prevalence of Anaplasma spp. in livestock by province was observed, with a higher prevalence in Selenge (74.2%, p<0.001) and Töv (64.2% p = 0.006) compared to the semi-arid region of Dornogovi (39.8%). In contrast, no association was observed in Bartonella prevalence by provinces. All Anaplasma sequences (N = 139) were characterized as A. ovis. For Bartonella species characterization, phylogenetic analyses of gltA and rpoB genes identified three Bartonella species including B. bovis, B. melophagi and Candidatus B. ovis. Bartonella bovis was detected in all 22-positive cattle, while B. melophagi and Candidatus B. ovis were found in four and three sheep, respectively. This study identifies a high prevalence of tick-borne pathogens within the livestock population and to our knowledge, is the first time NGS methods have been used to explore tick-borne diseases in Mongolia. Further research is needed in Mongolia to better understand the clinical and economic burdens associated with tick-borne diseases in both livestock and pastoral herder populations.

Bartonella Infections in Cats and Cat Fleas in Lithuania

Bartonella are vector-borne parasitic bacteria that cause zoonotic infections in humans. One of the most common infections is cat-scratch disease caused by Bartonella henselae and Bartonella clarridgeiae. Cats are the major reservoir for these two species of bacteria, while cat fleas are vectors for the transmission of infection agents among cats. The aim of the present study was to investigate the presence of Bartonella infections in stray and pet cats and in cat fleas in Lithuania. Blood samples were taken from 163 cats presented in pet clinics and animal shelters. A total of 102 fleas representing two species, Ctenocephalides felis and Ctenocephalides canis, were collected from 12 owned cats that live both outdoors and indoors. Bartonella DNA in samples was detected using a nested PCR targeting the 16S–23S rRNA intergenic spacer (ITS) region. Bartonella DNA was detected in 4.9% (8/163) of the cats and 29.4% (30/102) of the fleas. Sequence analysis of the ITS region showed that the cats and fleas were infected with B. henselae, B. clarridgeiae and Bartonella sp., closely related to B. schoenbuchensis. This study is the first report on the prevalence and molecular characterization of Bartonella spp. in cats and cat fleas in Lithuania.

Two New Haplotypes of Bartonella sp. Isolated from Lipoptena fortisetosa (Diptera: Hippoboscidae) in SE Poland

Simple Summary

Lipoptena fortisetosa is a hematophagous ectoparasite of game animals feeding accidentally on companion animals and humans. Since the presence of numerous pathogenic microorganisms has been described in this species, monitoring its geographic distribution is of great epidemiological importance. To the best of our knowledge, we present two new haplotypes of Bartonella sp. isolated from L. fortisetosa in south-eastern Poland and confirm the presence of this invasive species in Lublin Voivodeship since 2013.

Abstract

Insects of the genus Lipoptena are parasitic arthropods with a broad host range. Due to the type of parasitism (hematophagy), their potential role as vectors of pathogens, i.e., Bartonella sp., Anaplasma phagocytophilum, Rickettsia spp., and Borrelia burgdorferi is considered. As the range of their occurrence has been changing dynamically in recent years and infestations of humans have increasingly been reported, these organisms are now the subject of numerous studies. Our research aimed to present the molecular characteristics of Bartonella sp. detected in Lipoptena fortisetosa parasitizing wild cervids in south-eastern Poland. Adults of Lipoptena spp. were collected from carcasses of roe deer and red deer between spring and autumn in 2013. The PCR method was used to detect Bartonella sp. in the insects. We report two new haplotypes of the rpoB gene of Bartonella sp. isolated from L. fortisetosa feeding on wild cervids in south-eastern Poland and the presence of this invasive ectoparasitic species in the studied area since 2013. Phylogenetic analyses of newly obtained Bartonella sp. haplotypes confirmed their unique position on the constructed tree and network topology. The rpoB gene sequences found belonging to lineage B support the view that this phylogenetic lineage represents a novel Bartonella species.

Several New Putative Bacterial ADP-Ribosyltransferase Toxins Are Revealed from In Silico Data Mining, Including the Novel Toxin Vorin, Encoded by the Fire Blight Pathogen Erwinia amylovora

Mono-ADP-ribosyltransferase (mART) toxins are secreted by several pathogenic bacteria that disrupt vital host cell processes in deadly diseases like cholera and whooping cough. In the last two decades, the discovery of mART toxins has helped uncover the mechanisms of disease employed by pathogens impacting agriculture, aquaculture, and human health. Due to the current abundance of mARTs in bacterial genomes, and an unprecedented availability of genomic sequence data, mART toxins are amenable to discovery using an in silico strategy involving a series of sequence pattern filters and structural predictions. In this work, a bioinformatics approach was used to discover six bacterial mART sequences, one of which was a functional mART toxin encoded by the plant pathogen, Erwinia amylovora, called Vorin. Using a yeast growth-deficiency assay, we show that wild-type Vorin inhibited yeast cell growth, while catalytic variants reversed the growth-defective phenotype. Quantitative mass spectrometry analysis revealed that Vorin may cause eukaryotic host cell death by suppressing the initiation of autophagic processes. The genomic neighbourhood of Vorin indicated that it is a Type-VI-secreted effector, and co-expression experiments showed that Vorin is neutralized by binding of a cognate immunity protein, VorinI. We demonstrate that Vorin may also act as an antibacterial effector, since bacterial expression of Vorin was not achieved in the absence of VorinI. Vorin is the newest member of the mART family; further characterization of the Vorin/VorinI complex may help refine inhibitor design for mART toxins from other deadly pathogens.

Assessing the value of bacteriological examination as a diagnostic tool in relation to meat inspection in cattle

In Denmark, lesions indicating acute generalised infection identified at meat inspection will result in total condemnation. An official bacteriological examination (BU) protocol can be used for slaughtered animals with lesions such as endocarditis and endophlebitis as an assisting diagnostic tool to confirm whether the condition is local or generalised. If local, the carcass can be approved after condemnation of the relevant organs. The BU involves cultivating samples from the spleen and muscle. The aim of this study was to assess the value of the BU protocol. The study was conducted from February to May 2019 at a Danish cattle abattoir. Three groups of slaughtered cattle were included: 24 cases consisting of cattle with endocarditis and endophlebitis, 25 control animals consisting of cattle fully approved at inspection and 16 animals condemned at inspection due to endocarditis and endophlebitis with complications. Samples were taken from the heart, liver, kidney, lung, spleen and muscles of each animal. The BU protocol was used for cultivation. Different types of colonies were identified using MALDI-TOF-MS analysis. One or more samples with bacterial growth were found in all condemned animals - in 16 out of the 24 case animals and in two out of 25 control animals. In all three groups, Trueperella pyogenes was the most frequently isolated bacterium (60%) followed by Fusobacterium necrophorum (10%). For the case animals, the organ most commonly found with bacterial growth was the liver (46%), followed by the lung (38%) and the kidney (38%), while 96% of the muscle samples were negative. For the condemned group, bacterial growth was found in 75% of the spleen samples, 56% of liver and lung samples, and 50% of the muscle samples. A statistical analysis of the samples from cases and controls showed strong pair-wise associations for the presence of bacteria between organs, but no pair-wise associations between presence of bacteria in the muscle and any of the organs. Hence, if bacteria are found e.g. in the liver, they are likely to be found in other organs, but not in the muscle. In total, 20 of the 24 case animals were fully or partly approved in accordance with the current rules for judgement. It was concluded that the BU protocol using spleen and muscle samples would be suitable as a diagnostic tool for the judgement of slaughtered animals in cases where there is doubt about the stage of the lesions observed.

Molecular detection and genetic diversity of Bartonella species in large ruminants and associated ectoparasites from the Brazilian Cerrado

Currently, five Bartonella species and an expanding number of Candidatus Bartonella species have globally been reported in ruminants. Likewise, different Bartonella genotypes were identified. However, studies relating to ruminant-associated Bartonella in Brazil are scarce. The current study aimed to assess the prevalence and genetic diversity of Bartonella in cattle, buffaloes and associated ectoparasites in Brazil. For this purpose, EDTA-blood samples from 75 cattle and 101 buffaloes were sampled. Additionally, 128 Rhipicephalus microplus and one Amblyomma sculptum ticks collected from cattle, and 197 R. microplus, one A. sculptum and 170 lice (Haematopinus tuberculatus) collected from buffaloes were included. Bartonella DNA was initially screened through an HRM real-time PCR assay targeting the 16S-23S internal transcribed spacer (ITS), and the positive samples were submitted to an additional HRM assay targeting the ssrA gene. The HRM-positive amplicons were sequenced, and the nucleotide identity was assessed by BLASTn. Bartonella spp.-positive DNA samples were analysed by conventional PCR assays targeting the gltA and rpoB genes, and then, the samples were cloned. Finally, the phylogenetic positioning and the genetic diversity of clones were assessed. Overall, 21 of 75 (28%) cattle blood samples and 13 of 126 (10.3%) associated ticks were positive for Bartonella bovis. Out of 101 buffaloes, 95 lice and 188 tick DNA samples, one (1%) buffalo and four (4.2%) lice were positive for Bartonella spp. Conversely, none of the ticks obtained from buffaloes were positive for Bartonella. The Bartonella sequences from buffaloes showed identity ranging from 100% (ITS and gltA) to 94% (ssrA) with B. bovis. In contrast, the Bartonella DNA sequences from lice were identical (100%) to uncultured Bartonella sp. detected in cattle tail louse (Haematopinus quadripertusus) from Israel in all amplified genes. The present study demonstrates the prevalence of new B. bovis genotypes and a cattle lice-associated Bartonella species in large ruminants and their ectoparasites from Brazil. These findings shed light on the distribution and genetic diversity of ruminant- and ectoparasite-related Bartonella in Brazil.

Bartonella spp. detection in ticks, Culicoides biting midges and wild cervids from Norway

Bartonella spp. are fastidious, gram-negative, aerobic, facultative intracellular bacteria that infect humans, and domestic and wild animals. In Norway, Bartonella spp. have been detected in cervids, mainly within the distribution area of the arthropod vector deer ked (Lipoptena cervi). We used PCR to survey the prevalence of Bartonella spp. in blood samples from 141 cervids living outside the deer ked distribution area (moose [Alces alces, n = 65], red deer [Cervus elaphus, n = 41] and reindeer [Rangifer tarandus, n = 35]), in 44 pool samples of sheep tick (Ixodes ricinus, 27 pools collected from 74 red deer and 17 from 45 moose) and in biting midges of the genus Culicoides (Diptera: Ceratopogonidae, 120 pools of 6,710 specimens). Bartonella DNA was amplified in moose (75.4%, 49/65) and in red deer (4.9%, 2/41) blood samples. All reindeer were negative. There were significant differences in Bartonella prevalence among the cervid species. Additionally, Bartonella was amplified in two of 17 tick pools collected from moose and in 3 of 120 biting midge pool samples. The Bartonella sequences amplified in moose, red deer and ticks were highly similar to B. bovis, previously identified in cervids. The sequence obtained from biting midges was only 81.7% similar to the closest Bartonella spp. We demonstrate that Bartonella is present in moose across Norway and present the first data on northern Norway specimens. The high prevalence of Bartonella infection suggests that moose could be the reservoir for this bacterium. This is the first report of bacteria from the Bartonella genus in ticks from Fennoscandia and in Culicoides biting midges worldwide.

Development and validation of a droplet digital PCR assay for the detection and quantification of Bartonella species within human clinical samples

This report describes the development, optimization, and validation of a ddPCR assay for the detection of Bartonella spp. DNA within several sample matrices, including clinical blood samples from patients with or without documented Bartonella spp. bacteremia. The Bartonella spp. ddPCR assay was developed based upon previously published TaqMan-based qPCR assays that can amplify DNA of over 25 Bartonella spp. Host DNA (housekeeping gene) amplification serves as a reference target to facilitate quantification. The efficiency, sensitivity, and specificity of the Bartonella spp. ddPCR assay was assessed by direct comparison with the current qPCR methods used by the Intracellular Pathogens Research Laboratory (North Carolina State University, North Carolina, USA), and Galaxy Diagnostics (Research Triangle Park, North Carolina, USA). Bartonella spp. ddPCR assay parameters were successfully optimized to detect Bartonella concentrations equivalent to 0.5 bacterial genome copies per microliter of blood (0.001 pg/ul of bacterial DNA). The number of droplets detected (resolution) for each concentration was consistent across each of four assessed time points. The Bartonella spp. ddPCR assay detected 16 species/strains including B. henselae; B. quintana; B. vinsonii subsp. berkhoffii (genotypes I, II, III and IV); B. vinsonii subsp. vinsonii; B. melophagi; B. volans; B. monaki; B. alsatica; B. bovis; B. elizabethae; B. clarridgeiae; and B. koehlerae. Bartonella DNA was detected in only one previously negative patient sample (119/120 negative; 99% specificity). The ddPCR sensitivity (53/112) was significantly better than qPCR (6/112) when testing patient blood and enrichment blood culture samples. The development of commercial ddPCR systems with integrated technologies has significantly streamlined the DNA detection process, making it more efficient and standardized for clinical diagnostic testing. The assay described in this work is the first step toward the development of a multiplex ddPCR assay (i.e., using the QX One from Bio-Rad) for the simultaneous detection and absolute quantification of multiple vector-borne pathogens (such as Babesia, Bartonella and Borrelia) within clinical samples.

Bacterial and protozoan agents found in Hyalomma aegyptium (L., 1758) (Ixodida: Ixodidae) collected from Testudo graeca L., 1758 (Reptilia: Testudines) in Corum Province of Turkey

Hyalomma aegyptium (L., 1758) (Ixodida: Ixodidae) is a hard tick and the main host for adults are Palearctic tortoises of the genus Testudo, while larvae and nymphs are less host-specific and nymphs also attach to humans. In the present study, a total of 261 H. aegyptium ticks were removed from 26 Testudo graeca L., 1758 in Corum Province of Turkey. The most prevalent pathogens identified molecularly in the ticks were Hemolivia mauritanica (51.9 %), followed by Rickettsia aeschlimannii (32.6 %), Ehrlichia spp. (30.2 %), and Bartonella bovis (0.8 %). All samples were negative for Coxiella burnetii, Francisella tularensis, Anaplasma phagocytophilum, Babesia spp., Hepatozoon spp. and Theileria spp. Overall, 97.4 % of the examined adult ticks and 26.3 % of nymphs were infected with at least one pathogen, while 40.9 % of all ticks were infected with only one pathogen, 27.4 % with two pathogens, and 9.9 % with three pathogens, concomitantly. Overall, 80.8 % of the examined blood smears of tortoises were H. mauritanica-positive, and the mean intensity of parasitemia was 4.8 % (1-21). As a conclusion, since the examined tortoises were sampled in gardens and vineyards close to human habitation, and as a relatively large percentage of them were infested with ticks carrying pathogenic agents affecting also humans, the importance of tortoises, their ticks and pathogens in terms of the public health should be farther examined.

Bartonella bovis and Bartonella chomelii infection in dairy cattle and their ectoparasites in Algeria

Bartonella are blood-borne and vector-transmitted bacteria, some of which are zoonotic. B. bovis and B. chomelii have been reported in cattle. However, no information has yet been provided on Bartonella infection in cattle in Algeria. Therefore, 313 cattle from 45 dairy farms were surveyed in Kabylia, Algeria, in order to identify Bartonella species infecting cattle using serological and molecular tests. In addition, 277 ticks and 33 Hippoboscidae flies were collected. Bartonella bovis and B. chomelii were identified as the two species infecting cattle. Bartonella DNA was also amplified from 6.8 % (n = 19) of ticks and 78.8 % (n = 26) of flies. Prevalence of B. bovis DNA in dairy cattle was associated both with age and altitude. This study is the first one to report of bovine bartonellosis in Algeria, both in dairy cattle and in potential Bartonella vectors, with the detection of B. bovis DNA in tick samples and B. chomelii in fly samples.

Molecular Detection of Bartonella spp. in China and St. Kitts

Bartonella are vector-borne hemotropic bacteria that infect a wide variety of hosts, including people. While there are PCR assays that can identify individual or groups of Bartonella, there is no reliable molecular method to simultaneously detect all species while maintaining genus specificity and sensitivity. By comparing highly conserved 16S rRNA sequences of the better-recognized Bartonella spp. on GenBank, we selected primers and probes for a genus-specific pan-Bartonella FRET-qPCR. Then, a gltA-based Bartonella PCR was established by selecting primers for a highly variable region of gltA, of which the sequenced amplicons could identify individual Bartonella spp. The pan-Bartonella FRET-qPCR did not detect negative controls (Brucella spp., Anaplasma spp., Rickettsia spp., Coxiella burnetii, and Wolbachia) but reliably detected as few as two copies of the positive control (Bartonella henselae) per reaction. There was complete agreement between the pan-Bartonella FRET-qPCR and the gltA-based Bartonella PCR in detecting Bartonella in convenience test samples from China and St. Kitts: cats (26%; 81/310), Ctenocephalides felis (20%; 12/60), cattle (24%; 23/98), and donkeys (4%; 1/20). Sequencing of the gltA-based Bartonella PCR products revealed B. henselae (70%; 57/81) and B. clarridgeiae (30%; 24/81) in cats and C. felis (67%; 8/12, and 33%; 4/12, respectively) and B. bovis in cattle (23.5%; 23/98) and donkeys (4.0%; 1/24). The pan-Bartonella FRET-qPCR and gltA-based Bartonella PCR we developed are highly sensitive and specific in detecting recognized Bartonella spp. in a single reaction. The pan-Bartonella FRET-qPCR is convenient requiring no gel electrophoresis and providing copy numbers, while the gltA-based Bartonella PCR reliably differentiates individual Bartonella species. The use of these PCRs should greatly facilitate large-scale surveillance studies and the diagnosis of infections in clinical samples.

Molecular evidence of bacteria in Melophagus ovinus sheep keds and Hippobosca equina forest flies collected from sheep and horses in northeastern Algeria

The sheep ked, Melophagus ovinus, and the forest fly, Hippobosca equina, are parasitic dipteran insects of veterinary importance. As hematophagous insects, they might be considered as potential vectors of diseases which may be transmissible to humans and animals. The purpose of this study was to present initial primary data about these two species in Algeria. To do so, we conducted a molecular survey to detect the presence of bacterial DNA in flies collected in Algeria. A total of 712 flies including, 683 Melophagus ovinus and 29 Hippobosca equina were collected from two regions in northeastern Algeria. Monitoring the monthly kinetics of M. ovinus infestations showed something resembling annual activity, with a high prevalence in January (21.67%) and May (20.94%). Real-time quantitative PCR assays showed that for 311 tested flies, 126 were positive for the Bartonella spp. rRNA intergenic spacer gene and 77 were positive for Anaplasmataceae. A random selection of positive samples was submitted for sequencing. The DNA of Bartonella chomelii and Bartonella melophagi were amplified in, respectively, five and four H. equina. 25 M. ovinus positive samples were infected by Bartonella melophagi. Amplification and sequencing of the Anaplasma spp. 23S rRNA gene revealed that both species were infected by Wolbachia sp. which had previously been detected in Cimex lectularius bed bugs. Overall, this study expanded knowledge about bacteria present in parasitic flies of domestic animals in Algeria.

Microbiome Analysis Reveals the Presence of Bartonella spp. and Acinetobacter spp. in Deer Keds (Lipoptena cervi)

The deer ked (Lipoptena cervi) is distributed in Europe, North America, and Siberia and mainly infests cervids as roe deer, fallow deer, and moose. From a one health perspective, deer keds occasionally bite other animals or humans and are a potential vector for Bartonella schoenbuchensis. This bacterium belongs to a lineage of ruminant-associated Bartonella spp. and is suspected to cause dermatitis and febrile diseases in humans. In this study, we analyzed the microbiome from 130 deer keds collected from roe deer, fallow deer and humans in the federal states of Hesse, Baden-Wuerttemberg, and Brandenburg, Germany. Endosymbiontic Arsenophonus spp. and Bartonella spp. represented the biggest portion (~90%) of the microbiome. Most Bartonella spp. (n = 93) were confirmed to represent B. schoenbuchensis. In deer keds collected from humans, no Bartonella spp. were detected. Furthermore, Acinetobacter spp. were present in four samples, one of those was confirmed to represent A. baumannii. These data suggest that deer keds harbor only a very narrow spectrum of bacteria which are potentially pathogenic for animals of humans.

Triatomines: Trypanosomatids, Bacteria, and Viruses Potential Vectors?

Triatominae bugs are the vectors of Chagas disease, a major concern to public health especially in Latin America, where vector-borne Chagas disease has undergone resurgence due mainly to diminished triatomine control in many endemic municipalities. Although the majority of Triatominae species occurs in the Americas, species belonging to the genus Linshcosteus occur in India, and species belonging to the Triatoma rubrofasciata complex have been also identified in Africa, the Middle East, South-East Asia, and in the Western Pacific. Not all of Triatominae species have been found to be infected with Trypanosoma cruzi, but the possibility of establishing vector transmission to areas where Chagas disease was previously non-endemic has increased with global population mobility. Additionally, the worldwide distribution of triatomines is concerning, as they are able to enter in contact and harbor other pathogens, leading us to wonder if they would have competence and capacity to transmit them to humans during the bite or after successful blood feeding, spreading other infectious diseases. In this review, we searched the literature for infectious agents transmitted to humans by Triatominae. There are reports suggesting that triatomines may be competent vectors for pathogens such as Serratia marcescens, Bartonella, and Mycobacterium leprae, and that triatomine infection with other microrganisms may interfere with triatomine-T. cruzi interactions, altering their competence and possibly their capacity to transmit Chagas disease.

Genetic diversity, infection prevalence, and possible transmission routes of Bartonella spp. in vampire bats

Bartonella spp. are globally distributed bacteria that cause endocarditis in humans and domestic animals. Recent work has suggested bats as zoonotic reservoirs of some human Bartonella infections; however, the ecological and spatiotemporal patterns of infection in bats remain largely unknown. Here we studied the genetic diversity, prevalence of infection across seasons and years, individual risk factors, and possible transmission routes of Bartonella in populations of common vampire bats (Desmodus rotundus) in Peru and Belize, for which high infection prevalence has previously been reported. Phylogenetic analysis of the gltA gene for a subset of PCR-positive blood samples revealed sequences that were related to Bartonella described from vampire bats from Mexico, other Neotropical bat species, and streblid bat flies. Sequences associated with vampire bats clustered significantly by country but commonly spanned Central and South America, implying limited spatial structure. Stable and nonzero Bartonella prevalence between years supported endemic transmission in all sites. The odds of Bartonella infection for individual bats was unrelated to the intensity of bat flies ectoparasitism, but nearly all infected bats were infested, which precluded conclusive assessment of support for vector-borne transmission. While metagenomic sequencing found no strong evidence of Bartonella DNA in pooled bat saliva and fecal samples, we detected PCR positivity in individual saliva and feces, suggesting the potential for bacterial transmission through both direct contact (i.e., biting) and environmental (i.e., fecal) exposures. Further investigating the relative contributions of direct contact, environmental, and vector-borne transmission for bat Bartonella is an important next step to predict infection dynamics within bats and the risks of human and livestock exposures.

Infections with Bartonella spp. in free-ranging cervids and deer keds (Lipoptena cervi) in Norway

Bartonella bacteria are arthropod-borne and can cause long-term bacteremia in humans and animals. The predominant arthropod vectors and the mode of transmission for many novel Bartonella species remain elusive or essentially unstudied. The aim of this study was to investigate the prevalence of Bartonella spp. in Norwegian cervids and deer keds (Lipoptena cervi) and to characterise the bacteria by sequencing of the partial gltA gene and 16 S-23 S rRNA intergenic spacer region (ITS) in order to evaluate a possible transmission route. A total of 260 spleen samples and 118 deer keds were collected from cervids by hunters in the Southern part of Norway. Bartonella DNA was detected in 10.5% of spleen samples of roe deer (n = 67), in 35.1% red deer (n = 37), in 35.9% moose (n = 156), and in 85% pools of adult wingless deer ked (n = 59). Two Bartonella lineages were identified based on phylogenetic analysis of the gltA gene and ITS region sequences.

Molecular detection of Bartonella species and haemoplasmas in wild African buffalo (Syncerus caffer) in Mozambique, Africa

The African buffalo (Syncerus caffer), a mammal species whose population is declining, can play a role as a reservoir or carrier of a wide number of arthropod-borne pathogens. Translocation procedures have been used as an alternative approach for species conservation. However, the veterinary aspects of this sort of procedures are extremely important to minimize the impact on animal health. In order to detectBartonellaand haemoplasmas, two important group of bacterial that have an impact in both human and animal health, EDTA whole-blood samples were screened for the presence of these bacterial pathogens by molecular techniques. As a result, a molecular occurrence of 4.1 and 15.4% forBartonellaspp. and haemoplasmas, respectively, was reported among 97 wild buffaloes sampled during a translocation procedure from Marromeu to Gorongosa Reserve, Mozambique. Additionally, phylogenetic analyses of the obtained sequences were conducted. At least, three bovine-associated pathogens, namelyB. bovis,M. wenyoniiand ‘CandidatusM. haemobos’, as well as a probably newBartonellagenotype/species were detected inS. caffer.Further studies are needed in order to determine whether these bacterial species may cause impact in buffaloes and other sympatric ruminant species living in the release site.

Bartonella dromedarii sp. nov. isolated from domesticated camels (Camelus dromedarius) in Israel

Bartonella spp. are fastidious, Gram-negative bacilli that cause a wide spectrum of diseases in humans. Most Bartonella spp. have adapted to a specific host, generally a domestic or wild mammal. Dromedary camels (Camelus dromedarius) have become a focus of growing public-health interest because they have been identified as a reservoir host for the Middle East respiratory syndrome coronavirus. Nevertheless, data on camel zoonoses are limited. We aimed to study the occurrence of Bartonella bacteremia among dromedaries in Israel. Nine of 51 (17.6%) camels were found to be bacteremic with Bartonella spp.; bacteremia levels ranged from five to >1000 colony-forming units/mL. Phylogenetic reconstruction based on the concatenated sequences of gltA and rpoB genes demonstrated that the dromedary Bartonella isolates are closely related to other ruminant-derived Bartonella spp., with B. bovis being the nearest relative. Using electron microscopy, the novel isolates were shown to be flagellated, whereas B. bovis is nonflagellated. Sequence comparisons analysis of the housekeeping genes ftsZ, ribC, and groEL showed the highest homology to B. chomelii, B. capreoli, and B. birtlesii, respectively. Sequence analysis of the gltA and rpoB revealed ∼96% identity to B. bovis, a previously suggested cutoff value for sequence-based differentiation of Bartonella spp., suggesting that this approach does not have sufficient discriminatory power for differentiating ruminant-related Bartonella spp. A comprehensive multilocus sequence typing (MLST) analysis based on nine genetic loci (gltA, rpoB, ftsZ, internal transcribed spacer (ITS), 16S rRNA, ribC, groEL, nuoG, and SsrA) identified seven sequence types of the new dromedary isolates. This is the first description of a Bartonella sp. from camelids. On the basis of a distinct reservoir and ecological niche, sequence analyses, and expression of flagella, we designate these isolates as a novel Bartonella sp. named Bartonella dromedarii sp. nov. Further studies are required to explore its zoonotic potential.

Detection of a Potential New Bartonella Species "Candidatus Bartonella rondoniensis" in Human Biting Kissing Bugs (Reduviidae; Triatominae)

BACKGROUND

Among the Reduviidae family, triatomines are giant blood-sucking bugs. They are well known in Central and South America where they transmit Trypanosoma cruzi to mammals, including humans, through their feces. This parasitic protozoan is the causative agent of Chagas disease, a major public health issue in endemic areas. Because of the medical and economic impact of Chagas disease, the presence of other arthropod-borne pathogens in triatomines was rarely investigated.

METHODOLOGY/PRINCIPAL FINDINGS

In this study, seven triatomines species involved in the transmission of T. cruzi were molecularly screened for the presence of known pathogens generally associated with arthropods, such as Rickettsia, Bartonella, Anaplasmataceae, Borrelia species and Coxiella burnetii. Of all included triatomine species, only Eratyrus mucronatus specimens tested positive for Bartonella species for 56% of tested samples. A new genotype of Bartonella spp. was detected in 13/23 Eratyrus mucronatus specimens, an important vector of T. cruzi to humans. This bacterium was further characterized by sequencing fragments of the ftsZ, gltA and rpoB genes. Depending on the targeted gene, this agent shares 84% to 91% of identity with B. bacilliformis, the agent of Carrion's disease, a deadly sandfly-borne infectious disease endemic in South America. It is also closely related to animal pathogens such as B. bovis and B. chomelii.

CONCLUSIONS

As E. mucronatus is an invasive species that occasionally feeds on humans, the presence of potentially pathogenic Bartonella-infected bugs could present another risk for human health, along with the T. cruzi issue.

Bartonella bovis and Candidatus Bartonella davousti in cattle from Senegal

In Senegal, domestic ruminants play a vital role in the economy and agriculture and as a food source for people. Bartonellosis in animals is a neglected disease in the tropical regions, and little information is available about the occurrence of this disease in African ruminants. Human bartonellosis due to Bartonella quintana has been previously reported in Senegal. In this study, 199 domestic ruminants, including 104 cattle, 43 sheep, and 52 goats were sampled in villages from the Senegalese regions of Sine Saloum and Casamance. We isolated 29 Bartonella strains, all exclusively from cattle. Molecular and genetic characterization of isolated strains identified 27 strains as Bartonella bovis and two strains as potentially new species. The strains described here represent the first Bartonella strains isolated from domestic ruminants in Senegal and the first putative new Bartonella sp. isolated from cattle in Africa.

Bartonella melophagi in blood of domestic sheep (Ovis aries) and sheep keds (Melophagus ovinus) from the southwestern US: Cultures, genetic characterization, and ecological connections

Bartonella melophagi sp. nov. was isolated from domestic sheep blood and from sheep keds (Melophagus ovinus) from the southwestern United States. The sequence analyses of the reference strain performed by six molecular markers consistently demonstrated that B. melophagi relates to but differ from other Bartonella species isolated from domestic and wild ruminants. Presence of 183 genes specific for B. melophagi, being absent in genomes of other Bartonella species associated with ruminants also supports the separation of this bacterial species from species of other ruminants. Bartonella DNA was detected in all investigated sheep keds; however, culturing of these bacteria from sheep blood rejects a speculation that B. melophagi is an obligatory endosymbiont. Instead, the results support the hypothesis that the domestic sheep is a natural host reservoir for B. melophagi and the sheep ked its main vector. This bacterium was not isolated from the blood of bighorn sheep and domestic goats belonging to the same subfamily Caprinae. B. melophagi has also been shown to be zoonotic and needs to be investigated further.

Molecular survey of tick-borne pathogens in Ixodid ticks collected from hunted wild animals in Tuscany, Italy

OBJECTIVE

To determine the prevalence of zoonotic tick-borne bacteria in feeding ticks removed from hunted wild animals.

METHODS

PCR was executed on DNA extracted from 77 tick pools to detect Anaplasma phagocytophilum, Bartonella spp., Borrelia burgdorferi sensu lato, Coxiella burnetii and Rickettsia spp.

RESULTS

A total of 432 ticks were collected: 30 (6.94%) Haemaphysalis punctata, 72 (16.7%) Dermacentor marginatus and 330 (76.38%) Ixodes ricinus. For each animal one or two pools of 3 ticks of the same species was constituted. Seventy-seven tick pools were examined by PCR: 58 (75.32%) resulted infected and among them 14 (18.18%) showed co-infections. In particular, 29 (37.66%) pools were positive for Bartonella spp., 23 (29.87%) for Anaplasma phagocytophilum, 16 (20.78%) for Rickettsia spp., and 5 (6.49%) for Borrelia burgdorferi s.l. All samples were negative for Coxiella burnetii.

CONCLUSIONS

The results demonstrate the presence of several zoonotic tick-borne pathogens in the studied area, and underline the risk of exposure to infections for hunters not only during the outdoor activity, but also when they manipulate hunted animals infested by infected ticks.

Prevalence and molecular heterogeneity of Bartonella bovis in cattle and Haemaphysalis bispinosa ticks in Peninsular Malaysia

Background

Bartonellosis is an emerging zoonotic infection responsible for a variety of clinical syndromes in humans and animals. Members of the genus Bartonella exhibit high degrees of genetic diversity and ecologic plasticity. The infection is usually transmitted to animals and humans through blood-feeding arthropod vectors such as fleas, lice, ticks and sandflies. This study was conducted to investigate the prevalence of Bartonella species in 184 beef cattle, 40 dairy cattle, 40 sheep and 40 goats in eight animal farms across Peninsular Malaysia. Bartonella-specific PCR assays and sequence analysis of partial fragments of the citrate synthase gene were used for detection and identification of B. bovis. Isolation of B. bovis was attempted from PCR-positive blood samples. Molecular heterogeneity of the isolates was investigated based on sequence analysis of gltA, ITS, rpoB genes, ERIC-PCR, as well as using an established multilocus sequence typing (MLST) method. The carriage rate of B. bovis in ticks was also determined in this study.

Results

B. bovis was detected using Bartonella gltA-PCR assays from ten (4.5 %) of 224 cattle blood samples, of which three (1.3 %) were from beef cattle and seven (3.1 %) were from dairy cattle. None of the blood samples from the sheep and goats understudied were positive for B. bovis. Haemaphysalis bispinosa and Rhipicephalus (Boophilus) microplus were the predominant tick species identified in this study. B. bovis was detected from eight of 200 H. bispinosa ticks and none from the R. microplus ticks. Isolation of B. bovis was successful from all PCR-positive cattle blood samples, except one. Strain differentiation of B. bovis isolates was attempted based on sequence analysis of gltA, ITS, rpoB, and ERIC-PCR assay. B. bovis isolates were differentiated into six genotypes using the approach. The genetic heterogeneity of the isolates was confirmed using MLST method. Of the six MLST sequence types identified, five were designated new sequence types (ST23-27), while one (ST18) had been reported previously from Thailand isolates. All except one isolates were segregated into lineage II. A new lineage (IIa) is proposed for a single isolate obtained from a dairy cow.

Conclusions

The current study reported the first detection of B. bovis infection in the cattle and H. bispinosa ticks in Peninsular Malaysia. At least six genotypes of B. bovis were found circulating in the cattle understudied. New MLST sequence types were identified in Malaysian B. bovis isolates. Further study is necessary to explore the zoonotic potential of B. bovis and the vector compatibility of H. bispinosa ticks.

Endocarditis associated with Erysipelothrix rhusiopathiae in a fat-tailed ram

Endocarditis is rarely reported in sheep and information presented for ovine endocarditis is based mostly on comparative findings in the cattle. Infective vegetative endocarditis of the right heart was diagnosed in a 3-year-old fat-tailed ram. Clinical findings included tachycardia, marked brisket edema, jugular veins distention and pulsation and pale mucous membranes. Hematologic abnormality included neutrophilic leukocytosis. Necropsy confirmed severe right atrioventricular and pulmonary valves vegetative endocarditis with evidence of right heart failure. Erysipelothrix rhusiopathiae was isolated from those vegetative lisions.

Lack of transplacental transmission of Bartonella bovis

Transplacental transmission of Bartonella spp. has been reported for rodents, but not for cats and has never been investigated in cattle. The objective of this study was to assess vertical transmission of Bartonella in cattle. Fifty-six cow-calf pairs were tested before (cows) and after (calves) caesarean section for Bartonella bacteremia and/or serology, and the cotyledons were checked for gross lesions and presence of the bacteria. None of the 29 (52%) bacteremic cows gave birth to bacteremic calves, and all calves were seronegative at birth. Neither placentitis nor vasculitis were observed in all collected cotyledons. Bartonella bovis was not detected in placental cotyledons. Therefore, transplacental transmission of B. bovis and multiplication of the bacteria in the placenta do not seem likely. The lack of transplacental transmission may be associated with the particular structure of the placenta in ruminants or to a poor affinity/agressiveness of B. bovis for this tissue.

Bartonella chomelii is the most frequent species infecting cattle grazing in communal mountain pastures in Spain

The presence of Bartonella spp. was investigated in domestic ungulates grazing in communal pastures from a mountain area in northern Spain, where 18.3% (17/93) of cattle were found to be positive by PCR combined with a reverse line blot (PCR/RLB), whereas sheep (n = 133) or horses (n = 91) were found not to be infected by this pathogen. Bartonella infection was significantly associated with age, since older animals showed a higher prevalence than heifers and calves. In contrast to other studies, B. chomelii was the most frequent species found in cattle (14/17), while B. bovis was detected in only three animals. Moreover, 18 B. chomelii isolates and one B. bovis isolate were obtained from nine animals. Afterwards, B. chomelii isolates were characterized by a multilocus sequence typing (MLST) method which was adapted in this study. This method presented a high discrimination power, identifying nine different sequence types (STs). This characterization also showed the presence of different STs simultaneously in the same host and that STs had switched over time in one of the animals. In addition, B. chomelii STs seem to group phylogenetically in two different lineages. The only B. bovis isolate was characterized with a previously described MLST method. This isolate corresponded to a new ST which is located in lineage I, where the B. bovis strains infecting Bos taurus subsp. taurus are grouped. Further studies on the dynamics of Bartonella infection in cattle and the potential ectoparasites involved in the transmission of this microorganism should be performed, improving knowledge about the interaction of Bartonella spp. and domestic ungulates.

First description of Bartonella bovis in cattle herds in Israel

Bartonella bovis has been described in beef and dairy cattle worldwide, however the reported prevalence rates are inconsistent, with large variability across studies (0-89%). This study describes the first isolation and characterization of B. bovis among cattle herds in the Middle East. Blood samples from two beef cattle herds (each sampled thrice) and one dairy herd (sampled twice) in Israel were collected during a 16-months period. Overall, 71 of 95 blood samples (75%) grew Bartonella sp., with prevalence of 78% and 59% in beef and dairy cattle, respectively. High level bacteremia (≥100,000 colony forming units/mL) was detected in 25 specimens (26%). Such high-level bacteremia has never been reported in cattle. Two dairy cows and one beef cow remained bacteremic when tested 60 or 120 days apart, respectively, suggesting that cattle may have persistent bacteremia. One third of animals were infested with ticks. Sequence analysis of a gltA fragment of 32 bacterial isolates from 32 animals revealed 100% homology to B. bovis. Species identification was confirmed by sequence analysis of the rpoB gene. Phylogenetic analysis based on the concatenated sequences of gltA and rpoB demonstrated that the isolates described herein form a monophyletic group with B. bovis strains originating from cattle worldwide. Taken together, the high prevalence of bacteremia, including high-level bacteremia, in beef and dairy cattle, the potential to develop prolonged bacteremia, the exposure of cattle to arthropod vectors, and proximity of infected animals to humans, make B. bovis a potential zoonotic agent.

A descriptive review of the prevalence and risk factors of hock lesions in dairy cows

This article reviews the literature on hock lesions in dairy cattle, focusing in particular on their prevalence and associated clinical signs, as well as the scoring systems used to assess them and the data on risk factors. This analysis was limited to hock lesions where there was inflammation and damage of the skin and the subcutaneous tissue only without involvement of the joint. The presence of hock lesions, or tarsal peri-arthritis, is strongly related to time spent lying on abrasive surfaces, prolonged high local pressure or friction of the hock on hard surfaces, and collisions of the hock with cubicle fittings. Since hocks have almost no fatty tissue or muscles between the bones and skin, there is no protection against these types of trauma and skin damage occurs (resulting in hock lesions). The risk of these lesions becoming infected is strongly dependent on the hygiene of the lying area. The prevalence of hock lesions in dairy cows is generally reported as high (>50%). As hock lesions are often correlated with lameness, they are associated with economic losses and impaired welfare, as well as negative societal perception of the dairy sector. Alterations in cubicle characteristics, bedding material, pasture access and lameness prevention may all lower the prevalence of hock lesions; nevertheless, the actual relationship between housing design and other cow- and management-related risk factors on the occurrence of hock lesions appears to be complex and interrelated.

Identification of different Bartonella species in the cattle tail louse (Haematopinus quadripertusus) and in cattle blood

Bartonella spp. are worldwide-distributed facultative intracellular bacteria that exhibit an immense genomic diversity across mammal and arthropod hosts. The occurrence of cattle-associated Bartonella species was investigated in the cattle tail louse Haematopinus quadripertusus and in dairy cattle blood from Israel. Lice were collected from cattle from two dairy farms during summer 2011, and both lice and cow blood samples were collected from additional seven farms during the successive winter. The lice were identified morphologically and molecularly using 18S rRNA sequencing. Thereafter, they were screened for Bartonella DNA by conventional and real-time PCR assays using four partial genetic loci (gltA, rpoB, ssrA, and internal transcribed spacer [ITS]). A potentially novel Bartonella variant, closely related to other ruminant bartonellae, was identified in 11 of 13 louse pools collected in summer. In the cattle blood, the prevalence of Bartonella infection was 38%, identified as B. bovis and B. henselae (24 and 12%, respectively). A third genotype, closely related to Bartonella melophagi and Bartonella chomelii (based on the ssrA gene) and to B. bovis (based on the ITS sequence) was identified in a single cow. The relatively high prevalence of these Bartonella species in cattle and the occurrence of phylogenetically diverse Bartonella variants in both cattle and their lice suggest the potential role of this animal system in the generation of Bartonella species diversity.

Molecular detection of Bartonella spp. in deer ked pupae, adult keds and moose blood in Finland

The deer ked (Lipoptena cervi) is a haematophagous ectoparasite of cervids that harbours haemotrophic Bartonella. A prerequisite for the vector competence of the deer ked is the vertical transmission of the pathogen from the mother to its progeny and transstadial transmission from pupa to winged adult. We screened 1154 pupae and 59 pools of winged adult deer keds from different areas in Finland for Bartonella DNA using PCR. Altogether 13 pupa samples and one winged adult deer ked were positive for the presence of Bartonella DNA. The amplified sequences were closely related to either B. schoenbuchensis or B. bovis. The same lineages were identified in eight blood samples collected from free-ranging moose. This is the first demonstration of Bartonella spp. DNA in a winged adult deer ked and, thus, evidence for potential transstadial transmission of Bartonella spp. in the species.

Global distribution of Bartonella infections in domestic bovine and characterization of Bartonella bovis strains using multi-locus sequence typing

Bartonella bovis is commonly detected in cattle. One B. bovis strain was recently isolated from a cow with endocarditis in the USA, suggesting its role as an animal pathogen. In the present study, we investigated bartonella infections in 893 cattle from five countries (Kenya, Thailand, Japan, Georgia, and Guatemala) and 103 water buffaloes from Thailand to compare the prevalence of the infection among different regions and different bovid hosts. We developed a multi-locus sequence typing (MLST) scheme based on nine loci (16S rRNA, gltA, ftsZ, groEL, nuoG, ribC, rpoB, ssrA, and ITS) to compare genetic divergence of B. bovis strains, including 26 representatives from the present study and two previously described reference strains (one from French cows and another from a cow with endocarditis in the USA). Bartonella bacteria were cultured in 6.8% (7/103) of water buffaloes from Thailand; all were B. bovis. The prevalence of bartonella infections in cattle varied tremendously across the investigated regions. In Japan, Kenya, and the Mestia district of Georgia, cattle were free from the infection; in Thailand, Guatemala, and the Dusheti and Marneuli districts of Georgia, cattle were infected with prevalences of 10-90%. The Bartonella isolates from cattle belonged to three species: B. bovis (n=165), B. chomelii (n=9), and B. schoenbuchensis (n=1), with the latter two species found in Georgia only. MLST analysis suggested genetic variations among the 28 analyzed B. bovis strains, which fall into 3 lineages (I, II, and III). Lineages I and II were found in cattle while lineage III was restricted to water buffaloes. The majority of strains (17/28), together with the strain causing endocarditis in a cow in the USA, belonged to lineage I. Further investigations are needed to determine whether B. bovis causes disease in bovids.

Bartonella bovis isolated from a cow with endocarditis

A 7-year-old pregnant Angus cow was found dead in the field. At necropsy, the aortic valve was expanded by moderate fibrous connective tissue and acidophilic coagulum containing multifocal marked bacteria, mineral, neutrophils, and red blood cells. Numerous tiny grayish, opaque bacterial colonies were detected on blood agar plates at 7 days after inoculation with a swab of the heart valve of the cow. The bacterium was a Gram-negative, very small coccobacillus that was catalase, oxidase, and urease negative, and did not change litmus milk, triple sugar iron agar, and sulfide-indole-motility medium. The bacterium was negative for esculin hydrolysis, phenylalanine deaminase, nitrate reduction, and gelatin hydrolysis. The isolate did not produce acid from glycerol, inulin, lactose, maltose, mannose, raffinose, salicin, sorbitol, sucrose, trehalose, glycogen, ribose, or starch. Polymerase chain reaction tests for the gltA, ssrA, ftsZ, ribC, rpoB, and 16S ribosomal RNA genes of Bartonella species were positive for the isolate. Amplicons were sequenced, and the gltA, ribC, ssrA, and 16S ribosomal RNA gene sequences were found to have 100% homology to the type strain of Bartonella bovis, whereas the fts and rpoB sequences showed 99.9% and 99.6% homology, respectively, to the type strain of Bartonella bovis. Diagnosticians should be aware of slow-growing microorganisms, and culture media should be incubated beyond the standard period to enhance the recovery of Bartonella species.

Koch's postulates and the pathogenesis of comparative infectious disease causation associated with Bartonella species

In his homage to Lucretius (‘Georgica’), Vergil is credited with stating: ‘Felix qui potuit rerum cognoscere causas’ (‘Fortunate is he who knows the causes of things’). Based on numerous commentaries and publications it is obvious that clinicians, diagnosticians and biomedical research scientists continue to struggle with disease causation, particularly in the assessment of the pathogenic role of ‘stealth pathogens’ that produce persistent infections in the host. Bartonella species, because of their evolutionary ability to induce persistent intravascular infections, present substantial challenges for researchers attempting to clarify the ability of these stealth bacteria to cause disease. By studying the comparative biological and pathological behaviour of microbes across mammalian genera, researchers might be able more rapidly to advance medical science and, subsequently, patient care by undertaking focused research efforts involving a single mammalian species or by attempting to recapitulate a complex disease in an rodent model. Therefore, in an effort to further assist in the establishment of disease causation by stealth pathogens, we use recent research observations involving the genus Bartonella to propose an additional postulate of comparative infectious disease causation to Koch's postulates.

Bartonella infections in deer keds (Lipoptena cervi) and moose (Alces alces) in Norway

Infections with Bartonella spp. have been recognized as emerging zoonotic diseases in humans. Large knowledge gaps exist, however, relating to reservoirs, vectors, and transmission of these bacteria. We describe identification by culture, PCR, and housekeeping gene sequencing of Bartonella spp. in fed, wingless deer keds (Lipoptena cervi), deer ked pupae, and blood samples collected from moose, Alces alces, sampled within the deer ked distribution range in Norway. Direct sequencing from moose blood sampled in a deer ked-free area also indicated Bartonella infection but at a much lower prevalence. The sequencing data suggested the presence of mixed infections involving two species of Bartonella within the deer ked range, while moose outside the range appeared to be infected with a single species. Bartonella were not detected or cultured from unfed winged deer keds. The results may indicate that long-term bacteremia in the moose represents a reservoir of infection and that L. cervi acts as a vector for the spread of infection of Bartonella spp. Further research is needed to evaluate the role of L. cervi in the transmission of Bartonella to animals and humans and the possible pathogenicity of these bacteria for humans and animals.

The first cases of Bartonella bovis infection in cattle from Central Europe

Bartonella bovis was recently identified as a cause of bovine endocarditis, although Bartonella infections in natural hosts are usually asymptomatic. The disease is often misdiagnosed and is only discovered during the slaughtering process. In Europe B. bovis infections in cattle were reported only in France and Italy, nothing is known about the occurrence of B. bovis in cattle for the northern and eastern parts of Europe. The aim of our study was to search for Bartonella DNA in cattle in Central Europe (Poland) using three different loci (rpoB, ITS 16-23S rRNA, gltA). Our study resulted in the first detection of the asymptomatic B. bovis infection in 6.8% (12/177) of cattle in Central Europe. The potential role of B. bovis as a zoonotic agent for domestic animals and human diseases creates the need for further studies of these bacteria in natural and accidental hosts.

Pyrosequencing-based analysis of the microbiome associated with the horn fly, Haematobia irritans

The horn fly, Haematobia irritans, is one of the most economically important pests of cattle. Insecticides have been a major element of horn fly management programs. Growing concerns with insecticide resistance, insecticide residues on farm products, and non-availability of new generation insecticides, are serious issues for the livestock industry. Alternative horn fly control methods offer the promise to decrease the use of insecticides and reduce the amount of insecticide residues on livestock products and give an impetus to the organic livestock farming segment. The horn fly, an obligatory blood feeder, requires the help of microflora to supply additional nutrients and metabolize the blood meal. Recent advancements in DNA sequencing methodologies enable researchers to examine the microflora diversity independent of culture methods. We used the bacterial 16S tag-encoded FLX-titanium amplicon pyrosequencing (bTEFAP) method to carry out the classification analysis of bacterial flora in adult female and male horn flies and horn fly eggs. The bTEFAP method identified 16S rDNA sequences in our samples which allowed the identification of various prokaryotic taxa associated with the life stage examined. This is the first comprehensive report of bacterial flora associated with the horn fly using a culture-independent method. Several rumen, environmental, symbiotic and pathogenic bacteria associated with the horn fly were identified and quantified. This is the first report of the presence of Wolbachia in horn flies of USA origin and is the first report of the presence of Rikenella in an obligatory blood feeding insect.

Experimental infection of horses with Bartonella henselae and Bartonella bovis

BACKGROUND

Experimental infection of horses with Bartonella species is not documented.

OBJECTIVES

Determine clinical signs, hematologic changes, duration of bacteremia, and pattern of seroconversion in Bartonella henselae or Bartonella bovis-inoculated horses.

ANIMALS

Twelve (2 groups of 6) randomly selected healthy adult horses seronegative and culture negative for Bartonella spp.

METHODS

Experimental/observational study: Group I: B. henselae or saline control was inoculated intradermally into 4 naïve and 2 sentinel horses, respectively. Group II: same design was followed by means of B. bovis. Daily physical examinations, once weekly CBC, immunofluorescent antibody assay serology, real-time polymerase chain reaction (PCR), and twice weekly blood cultures were performed for 6 weeks and at postinoculation day 80 and 139. Bartonella alpha-Proteobacteria growth medium (BAPGM) enrichment blood culture was performed for horses that seroconverted to B. henselae antigens.

RESULTS

Transient clinical signs consistent with bartonellosis occurred in some Bartonella-inoculated horses, but hematological alterations did not occur. Three B. henselae-inoculated horses seroconverted, whereas 1 B. bovis-inoculated horse was weakly seropositive. In Group I, B. henselae was amplified and sequenced from BAPGM blood culture as well as a subculture isolate from 1 horse, blood from a 2nd horse, and BAPGM blood culture from a 3rd horse although a subculture isolate was not obtained. All sentinels remained PCR, culture, and serology negative.

CONCLUSIONS

Detection of Bartonella sp. in blood after experimental inoculation supports bacteremia and seroconversion. Culture with BAPGM may be required to detect Bartonella sp. Although mild clinical signs followed acute infection, no long-term effects were noted for 2 years postinoculation.

Bartonella and Babesia infections in cattle and their ticks in Taiwan

Bartonella and Babesia infections and the association with cattle breed and age as well as tick species infesting selected cattle herds in Taiwan were investigated. Blood samples were collected from 518 dairy cows and 59 beef cattle on 14 farms and 415 ticks were collected from these animals or in a field. Bartonella and Babesia species were isolated and/or detected in the cattle blood samples and from a selected subset (n=254) of the ticks either by culture or DNA extraction, PCR testing and DNA sequence analysis. Bartonella bovis was isolated from a dairy cow and was detected in 25 (42.4%) beef cattle and 40 (15.7%) tick DNA samples. This is the first isolation of B. bovis from cattle in Asia and detection of a wide variety of Bartonella species in Rhipicephalus microplus. Babesia spp. were detected only on one farm from dairy cows either infected by Babesia bovis (n=10, 1.9%) or B. bigemina (n=3, 0.6%).

Murine model for Bartonella birtlesii infection: New aspects

As a model of persistent infection, various aspects of Bartonella birtlesii infection in laboratory mice, including some immunodeficient mice, are presented, particularly focusing on conditions mimicking natural infection. Bacteraemia was explored using different mice strains routes and inoculum doses (3.4-5x10(7)CFU/mouse). Mice became bacteraemic for 5 (C57Bl6/6) to 10 weeks (Balb/c, Swiss) with peaks ranging from 2x10(3) to 10(5)CFU/mL of blood. The ID route induced the most precocious bacteraemia (day 3) while the higher and longer bacteraemia in immunocompetent mice was obtained with SC when infecting Balb/c with approximately 10(3) CFU/mouse. As opposed to ID, SC and IV routes, bacteraemia was obtained with the oral and ocular routes only for high doses (10(7)) and in 33-66% mice. It was significantly higher and longer in CD4-/- mice compared to CD8-/- and double KO mice at most time points. CD8-/- mice and the control group had near to superimposed kinetics. These results confirm the relevance of the present model.