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

Epidemiology of Bartonella henselae infection in pet and stray cats in Croatia with risk factors analysis

BACKGROUND

Cats are the primary reservoirs of the bacterium Bartonella henselae, the main cause of cat-scratch disease in humans. The main vector of the bacterium is the cat flea, Ctenocephalides felis. In southeastern Europe, data are lacking on the prevalence of B. henselae infection in cats, the strains of B. henselae involved and the risk factors associated with the infection.

METHODS

Blood samples collected in ethylenediaminetetraacetic acid-containing tubes from 189 domestic cats (156 pet cats and 33 stray cats) from Zagreb, the capital city of Croatia, and 10 counties throughout Croatia were cultured for Bartonella spp. Following culture, bacterial isolates were genotyped at eight loci after using PCR to amplify 16S ribosomal RNA (rRNA) and the internal transcribed spacer region between the 16S and 23S rRNA sequences. Univariate and multivariate logistic regression were used to identify risk factors for B. henselae infection in cats.

RESULTS

Bartonella spp. was detected in 31 cats (16.4%), and subsequent genotyping at the eight loci revealed B. henselae in all cases. Thirty complete multilocus sequence typing profiles were obtained, and the strains were identified as four sequence types that had been previously reported, namely ST5 (56.7%), ST6 (23.3%), ST1 (13.3%) and ST24 (3.3%), as well as a novel sequence type, ST33 (3.3%). The univariate analysis revealed a significantly higher risk of B. henselae infection in cats residing in coastal areas of Croatia (odds ratio [OR] 2.592, 95% confidence interval [CI] 1.150-5.838; P = 0.0191) and in cats with intestinal parasites (OR 3.207, 95% CI 1.088-9.457; P = 0.0279); a significantly lower risk was identified in cats aged > 1 year (OR 0.356, 95% CI 0.161-0.787; P = 0.0247) and in cats sampled between April and September (OR 0.325, 95% CI 0.147-0.715; P = 0.005). The multivariate analysis that controlled for age showed a positive association with the presence of intestinal parasites (OR 4.241, 95% CI 1.243-14.470; P = 0.0119) and coastal residence (OR 2.567, 95% CI 1.114-5.915; P = 0.0216) implying increased risk of infection, and a negative association with sampling between April and September (OR 0.379, 95% CI 0.169-0.848; P = 0.018) implying a decreased risk of infection. After controlling for the season, an increased risk of infection remained for the coastal region (OR 2.725, 95% CI 1.200-6.186; P = 0.012).

CONCLUSIONS

Bartonella henselae is prevalent throughout Croatia and is a public health threat. Environmental and host factors can significantly affect the risk of infection, and these should be explored in more detail. The presence of intestinal parasites highlights the need to eliminate the flea vector, Ctenocephalides felis, as the most effective approach to control infections in cats and humans.

Bartonella Infection in Fruit Bats and Bat Flies, Bangladesh

Bats harbor diverse intracellular Bartonella bacteria, but there is limited understanding of the factors that influence transmission over time. Investigation of Bartonella dynamics in bats could reveal general factors that control transmission of multiple bat-borne pathogens, including viruses. We used molecular methods to detect Bartonella DNA in paired bat (Pteropus medius) blood and bat flies in the family Nycteribiidae collected from a roost in Faridpur, Bangladesh between September 2020 and January 2021. We detected high prevalence of Bartonella DNA in bat blood (35/55, 64%) and bat flies (59/60, 98%), with sequences grouping into three phylogenetic clades. Prevalence in bat blood increased over the study period (33% to 90%), reflecting an influx of juvenile bats in the population and an increase in the prevalence of bat flies. Discordance between infection status and the clade/genotype of detected Bartonella was also observed in pairs of bats and their flies, providing evidence that bat flies take blood meals from multiple bat hosts. This evidence of bat fly transfer between hosts and the changes in Bartonella prevalence during a period of increasing nycteribiid density support the role of bat flies as vectors of bartonellae. The study provides novel information on comparative prevalence and genetic diversity of Bartonella in pteropodid bats and their ectoparasites, as well as demographic factors that affect Bartonella transmission and potentially other bat-borne pathogens.

Detection of bacterial and protozoan pathogens in individual bats and their ectoparasites using high-throughput microfluidic real-time PCR

Among the most studied mammals in terms of their role in the spread of various pathogens with possible zoonotic effects are bats. These are animals with a very complex lifestyle, diet, and behavior. They are able to fly long distances, thus maintaining and spreading the pathogens they may be carrying. These pathogens also include vector-borne parasites and bacteria that can be spread by ectoparasites such as ticks and bat flies. In the present study, high-throughput screening was performed and we detected three bacterial pathogens: Bartonella spp., Neoehrlichia mikurensis and Mycoplasma spp., and a protozoan parasite: Theileria spp. in paired samples from bats (blood and ectoparasites). In the samples from the bat-arthropod pairs, we were able to detect Bartonella spp. and Mycoplasma spp. which also showed a high phylogenetic diversity, demonstrating the importance of these mammals and the arthropods associated with them in maintaining the spread of pathogens. Previous studies have also reported the presence of these pathogens, with one exception, Neoehrlichia mikurensis, for which phylogenetic analysis revealed less genetic divergence. High-throughput screening can detect more bacteria and parasites at once, reduce screening costs, and improve knowledge of bats as reservoirs of vector-borne pathogens. IMPORTANCE The increasing number of zoonotic pathogens is evident through extensive studies and expanded animal research. Bats, known for their role as reservoirs for various viruses, continue to be significant. However, new findings highlight the emergence of Bartonella spp., such as the human-infecting B. mayotimonensis from bats. Other pathogens like N. mikurensis, Mycoplasma spp., and Theileria spp. found in bat blood and ectoparasites raise concerns, as their impact remains uncertain. These discoveries underscore the urgency for heightened vigilance and proactive measures to understand and monitor zoonotic pathogens. By deepening our knowledge and collaboration, we can mitigate these risks, safeguarding human and animal well-being.

Analysis of COI gene, prevalence, and intensity of the bat fly Cyclopodia greeffi on roosting straw-coloured fruit bat Eidolon helvum in Southwest Nigeria

We investigated ectoparasite diversity, interspecific infestation rates and host preference in roosting fruit bats, Eidolon helvum, from Bowen University, Southwest Nigeria. Fur of captured E. helvum were sampled monthly for ectoparasites from January 2021 to June 2022. We examined a total of 231 E. helvum and observed a significant female to male adult sex ratio (0.22:1); with 53.9% ectoparasitic infestation rate. We identified and enumerated the ectoparasite; and subjected its Cytochrome c oxidase subunit I (COI) gene to phylogenetic analysis with other nycteribiids. COI gene sequences obtained formed a distinct clade with other C. greeffi sequences. We recovered a total of 319 (149 female and 170 male) ectoparasites and observed a balanced C. greeffi female to male adult sex ratio of 0.88:1. Ectoparasitic sex distribution had no association with host sex and season. Prevalence was significantly higher during the wet season, but not between sexes of E. helvum. The intensity of infestation, 3.7 ± 0.4 individuals per fruit bat, was significantly higher during the wet season with a bimodal seasonal distribution. The strongly male-biased host adult sex ratio had no significant influence on C. greeffi metapopulation adult sex ratio.

Prevalence and Genetic Diversity of Bartonella Spp. in Northern Bats (Eptesicus nilssonii) and Their Blood-Sucking Ectoparasites in Hokkaido, Japan

We investigated the prevalence of Bartonella in 123 northern bats (Eptesicus nilssonii) and their ectoparasites from Hokkaido, Japan. A total of 174 bat fleas (Ischnopsyllus needhami) and two bat bugs (Cimex japonicus) were collected from the bats. Bartonella bacteria were isolated from 32 (26.0%) of 123 bats. Though Bartonella DNA was detected in 79 (45.4%) of the bat fleas, the bacterium was isolated from only one bat flea (0.6%). The gltA sequences of the isolates were categorized into genotypes I, II, and III, which were found in both bats and their fleas. The gltA sequences of genotypes I and II showed 97.6% similarity with Bartonella strains from a Finnish E. nilssonii and a bat flea from a E. serotinus in the Netherlands. The rpoB sequences of the genotypes showed 98.9% similarity with Bartonella strain 44722 from E. serotinus in Republic of Georgia. The gltA and rpoB sequences of genotype III showed 95.9% and 96.7% similarity with Bartonella strains detected in shrews in Kenya and France, respectively. Phylogenetic analysis revealed that Bartonella isolates of genotypes I and II clustered with Bartonella strains from Eptesicus bats in Republic of Georgia and Finland, Myotis bats in Romania and the UK, and a bat flea from an Eptesicus bat in Finland. In contrast, genotype III formed a clade with B. florencae, B. acomydis, and B. birtlesii. These data suggest that northern bats in Japan harbor two Bartonella species and the bat flea serves as a potential vector of Bartonella transmission among the bats.

New geographical records for tick-borne pathogens in ticks collected from cattle in Benin and Togo

BACKGROUND

Ticks are obligate hematophagous arthropods capable of transmitting a great variety of endemic and emerging pathogens causing diseases in animals and humans.

OBJECTIVES

The aim of this study was to investigate the presence of Bartonella spp., Rickettsia spp., Borrelia burgdorferi sensu lato (s.l.) and Anaplasma phagocytophilum in ticks collected from cattle in Benin and Togo.

METHODS

Overall, 396 (148 males, 205 females and 43 nymphs) ticks were collected from cattle in 17 districts (Benin and Togo) between 2019 and 2020. Ticks were pooled into groups of 2-6 ticks per pool according to individual host, location, species and developmental stage. The DNA of each pool was extracted for molecular screening.

RESULTS

PCR results revealed that 20 tick pools were positive for Bartonella spp. (Benin and Togo) and 23 tick pools positive for Rickettsia spp. (Benin), while all pools were negative for A. phagocytophilum and B. burgdorferi s.l. Sequence analysis of positive Rickettsia samples revealed the presence of Rickettsia aeschlimannii.

CONCLUSIONS

The present study highlights the presence of zoonotic agents in ticks collected from cattle in Benin and Togo. This information will raise awareness of tick-borne diseases among physicians and veterinarians, stimulate further studies to monitor these pathogens, and advise on necessary measures to control the spread of these zoonoses.

Molecular Detection and Phylogenetic Analyses of Diverse Bartonella Species in Bat Ectoparasites Collected from Yunnan Province, China

Bartonella species has been validated as blood-borne bacteria in mammals and has a substantial opportunity to be harbored by a variety of hematophagous arthropod vectors. Bats, along with their ectoparasites, are recognized worldwide as one of the natural reservoir hosts for these bacteria. However, there have been few investigations of Bartonella bacteria toward a broad range of obligated bat ectoparasites in China. Here, molecular detection of Bartonella species was performed to survey the infection among bat ectoparasites and follow-up phylogenetic analyses to further characterize the evolutionary relationships of the genus. A total of 434 bat ectoparasites involving four types of arthropods, namely, bat mites, bat tick, bat fleas, and bat flies (further divided into traditionally fly-like bat flies and wingless bat flies) were collected in 10 trapping sites in Yunnan Province, southwestern China. Bartonella was detected by PCR amplification and sequencing through four gene target fragments (gltA, ftsZ, rpoB, and ITS). Accordingly, diverse Bartonella species were discovered, including both the validated species and the novel genotypes, which were characterized into several geographical regions with high prevalence. Phylogenetic analyses based on gltA and multi-locus concatenated sequences both demonstrated strong phylogeny-trait associations of Bartonella species from bats and their parasitic arthropods, suggesting the occurrence of host switches and emphasizing the potential connecting vector role of these ectoparasites. Nevertheless, the maintenance and transmission of Bartonella in both bat and hemoparasite populations have not been fully understood, as well as the risk of spillage to humans, which warrants in-depth experimental studies focusing on these mammals and their ectoparasites.

Public Health Awareness on Bat Rabies among Bat Handlers and Persons Residing near Bat Roosts in Makurdi, Nigeria

Rabies is a neglected disease endemic in Asia and Africa but is still a significant public and veterinary health threat. Whilst a key delicacy for the local diet, bats are a natural reservoir host for many viral zoonotic agents including lyssaviruses, the causative agent of rabies. Studies on knowledge and practices linked to the disease will help to identify gaps and define preventive strategies that may subsequently result in a reduction and the potential elimination of human rabies. In order to assess the public health awareness of bat rabies among specific population groups in Makurdi (Nigeria), structured questionnaires (n = 154) were administered by face-to-face interviews to bat handlers and persons residing near bat roost sites. A total of 59.7% of the respondents were persons residing near bat roost sites, 13% were bat hunters, 25.3% were bat meat consumers and 1.9% were university researchers. Only 6.5% of respondents reported using some form of personal protective equipment (PPE) ranging from hand gloves, face/nose masks and protective boots to lab coats/coveralls while handling bats, whilst the majority (93.5%) did not use any form of PPE. With a mean knowledge score of 8.34 out of a possible 12 points, 50.6% of respondents had good knowledge of bats and their disease-carrying potential, 39.6% had fair knowledge, while 9.7% had poor knowledge. Log linear models showed significant associations between knowledge score and level of education, as well as knowledge score and occupation. The latter highlights the requirement to enhance public education among bat handlers and persons residing near bat roosts on the need to protect themselves better, while handling bats particularly during processing of bats for food and on steps to take when exposed to bites from bats.

Genetic Diversity of Bartonella spp. in Cave-Dwelling Bats and Bat Flies, Costa Rica, 2018

To determine Bartonella spp. dynamics, we sampled bats and bat flies across 15 roosts in Costa Rica. PCR indicated prevalence of 10.7% in bats and 29.0% in ectoparasite pools. Phylogenetic analysis of 8 sequences from bats and 5 from bat fly pools revealed 11 distinct genetic variants, including 2 potentially new genotypes.

A novel clade of bat-associated Bartonella detected in the bat fly Leptocyclopodia ferrari (Diptera: Nycteribiidae) parasitizing Cynopterus brachyotis (Chiroptera: Pteropodidae)

Bartonelloses are emerging infectious diseases that are common in humans and animals worldwide. Several Bartonella species associated with companion animals such as Bartonella henselae and Bartonella rochalimae are species with zoonotic implications and have become a global concern. Other Bartonella species associated with wild animals, however, remain underappreciated particularly in the developing regions of the world. To explore further on this neglected bacterial agent, Leptocyclopodia ferrari (Nycteribiidae) bat flies collected from Cynopterus brachyotis (Pteropodidae), an endemic fruit bat species in Southeast Asia, were molecularly examined for the presence of Bartonella. Both 16 S-23 S ribosomal RNA intergenic spacer region and citrate synthase gene sequences exhibited less than 95 % similarity to all previously reported Bartonella spp. Further phylogenetic analysis revealed a novel clade of this Bartonella sp. with high bootstrap support. The vectorial capacity of bat flies in transmitting this novel pathogen merits further investigation.

Bats and their ectoparasites (Nycteribiidae and Spinturnicidae) carry diverse novel Bartonella genotypes, China

Bartonella species are facultative intracellular bacteria and recognized worldwide as emerging zoonotic pathogens. Bartonella were isolated or identified by polymerase chain reaction (PCR) in bats and their ectoparasites worldwide, whereas the association between them was scarce, especially in Asia. In this study, a retrospective analysis with frozen samples was carried out to identify the genetic diversity of Bartonella in bats and their ectoparasites and to investigate the relationships of Bartonella carried by bats and their ectoparasites. Bats and their ectoparasites (bat flies and bat mites) were collected from caves in Hubei Province, Central China, from May 2018 to July 2020. Bartonella were screened by PCR amplification and sequencing of three genes (gltA, rpoB, and ftsZ). Bats, bat flies, and bat mites carried diverse novel Bartonella genotypes with a high prevalence. The sharing of some Bartonella genotypes between bats and bat flies or bat mites indicated a potential role of bat flies and bat mites as vectors of bartonellae, while the higher genetic diversity of Bartonella in bat flies than that in bats might be due to the vertical transmission of this bacterium in bat flies. Therefore, bat flies might also act as reservoirs of Bartonella. In addition, human‐pathogenic B. mayotimonesis was identified in both bats and their ectoparasites, which expanded our knowledge on the geographic distribution of this bacterium and suggested a potential bat origin with bat flies and bat mites playing important roles in the maintenance and transmission of Bartonella.

Virome of bat-infesting arthropods: highly divergent viruses in different vectors

Bats are reservoirs of important zoonotic viruses like Nipah and SARS viruses. However, whether the blood-sucking arthropods on the body surface of bats also carry these viruses, and the relationship between viruses carried by the blood-sucking arthropods and viruses carried by bats, have not been reported. This study collected 686 blood-sucking arthropods on the body surface of bats from Yunnan Province, China between 2012 and 2015, and they included wingless bat flies, bat flies, ticks, mites, and fleas. The viruses carried by these arthropods were analyzed using meta-transcriptomic approach, and 144 highly diverse positive-sense single-stranded RNA, negative-sense single-stranded RNA, and double-stranded RNA viruses were found, of which 138 were potentially new viruses. These viruses were classified into 14 different virus families or orders, including Bunyavirales, Mononegavirales, Reoviridae, and Picornavirales. Further analyses found that Bunyavirales were the most abundant virus group (84% of total virus RNA) in ticks, whereas narnaviruses were the most abundant (52-92%) in the bat flies and wingless bat flies libraries, followed by solemoviruses (1-29%) and reoviruses (0-43%). These viruses were highly structured based on the arthropod types. It is worth noting that no bat-borne zoonotic viruses were found in the virome of bat-infesting arthropod, seemly not supporting that bat surface arthropods are vectors of zoonotic viruses carried by bats. IMPORTANCE Bats are reservoir of many important viral pathogens. To evaluate whether bat-parasitic blood-sucking arthropods participate in the circulation of these important viruses, it is necessary to conduct unbiased virome studies on these arthropods. We evaluated five types of blood-sucking parasitic arthropods on the surface of bats in Yunnan, China and identified a variety of viruses, some of which had high prevalence and abundance level, although there is limited overlap in virome between distant arthropods. While most of the virome discovered here are potentially arthropod-specific viruses, we identified three possible arboviruses, including one orthobunyavirus and two vesiculoviruses (family Rhabdoviridae), suggesting bat-parasitic arthropods carry viruses with risk of spillage, which warrants further study.

Relationship among bats, parasitic bat flies, and associated pathogens in Korea

Background

Bats are hosts for many ectoparasites and act as reservoirs for several infectious agents, some of which exhibit zoonotic potential. Here, species of bats and bat flies were identified and screened for microorganisms that could be mediated by bat flies.

Methods

Bat species were identified on the basis of their morphological characteristics. Bat flies associated with bat species were initially morphologically identified and further identified at the genus level by analyzing the cytochrome c oxidase subunit I gene. Different vector-borne pathogens and endosymbionts were screened using PCR to assess all possible relationships among bats, parasitic bat flies, and their associated organisms.

Results

Seventy-four bat flies were collected from 198 bats; 66 of these belonged to Nycteribiidae and eight to Streblidae families. All Streblidae bat flies were hosted by Rhinolophus ferrumequinum, known as the most common Korean bat. Among the 74 tested bat flies, PCR and nucleotide sequencing data showed that 35 (47.3%) and 20 (27.0%) carried Wolbachia and Bartonella bacteria, respectively, whereas tests for Anaplasma, Borrelia, Hepatozoon, Babesia, Theileria, and Coxiella were negative. Phylogenetic analysis revealed that Wolbachia endosymbionts belonged to two different supergroups, A and F. One sequence of Bartonella was identical to that of Bartonella isolated from Taiwanese bats.

Conclusions

The vectorial role of bat flies should be checked by testing the same pathogen and bacterial organisms by collecting blood from host bats. This study is of great interest in the fields of disease ecology and public health owing to the bats’ potential to transmit pathogens to humans and/or livestock.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-021-05016-6.

Associations between Afrotropical bats, eukaryotic parasites, and microbial symbionts

Skin is the largest mammalian organ and the first defensive barrier against the external environment. The skin and fur of mammals can host a wide variety of ectoparasites, many of which are phylogenetically diverse, specialized, and specifically adapted to their hosts. Among hematophagous dipteran parasites, volatile organic compounds (VOCs) are known to serve as important attractants, leading parasites to compatible sources of blood meals. VOCs have been hypothesized to be mediated by host‐associated bacteria, which may thereby indirectly influence parasitism. Host‐associated bacteria may also influence parasitism directly, as has been observed in interactions between animal gut microbiota and malarial parasites. Hypotheses relating bacterial symbionts and eukaryotic parasitism have rarely been tested among humans and domestic animals, and to our knowledge have not been tested in wild vertebrates. In this study, we used Afrotropical bats, hematophagous ectoparasitic bat flies, and haemosporidian (malarial) parasites vectored by bat flies as a model to test the hypothesis that the vertebrate host microbiome is linked to parasitism in a wild system. We identified significant correlations between bacterial community composition of the skin and dipteran ectoparasite prevalence across four major bat lineages, as well as striking differences in skin microbial network characteristics between ectoparasitized and nonectoparasitized bats. We also identified links between the oral microbiome and presence of malarial parasites among miniopterid bats. Our results support the hypothesis that microbial symbionts may serve as indirect mediators of parasitism among eukaryotic hosts and parasites.

see also the Perspective by Kelly A. Speer

Bat Flies of the Family Streblidae (Diptera: Hippoboscoidea) Host Relatives of Medically and Agriculturally Important "Bat-Associated" Viruses

Bat flies (Hippoboscoidea: Nycteribiidae and Streblidae) are obligate hematophagous ectoparasites of bats. We collected streblid bat flies from the New World (México) and the Old World (Uganda), and used metagenomics to identify their viruses. In México, we found méjal virus (Rhabdoviridae; Vesiculovirus), Amate virus (Reoviridae: Orbivirus), and two unclassified viruses of invertebrates. Méjal virus is related to emerging zoonotic encephalitis viruses and to the agriculturally important vesicular stomatitis viruses (VSV). Amate virus and its sister taxon from a bat are most closely related to mosquito- and tick-borne orbiviruses, suggesting a previously unrecognized orbivirus transmission cycle involving bats and bat flies. In Uganda, we found mamucuso virus (Peribunyaviridae: Orthobunyavirus) and two unclassified viruses (a rhabdovirus and an invertebrate virus). Mamucuso virus is related to encephalitic viruses of mammals and to viruses from nycteribiid bat flies and louse flies, suggesting a previously unrecognized orthobunyavirus transmission cycle involving hippoboscoid insects. Bat fly virus transmission may be neither strictly vector-borne nor strictly vertical, with opportunistic feeding by bat flies occasionally leading to zoonotic transmission. Many "bat-associated" viruses, which are ecologically and epidemiologically associated with bats but rarely or never found in bats themselves, may actually be viruses of bat flies or other bat ectoparasites.

Rickettsia hoogstraalii and a Rickettsiella from the Bat Tick Argas transgariepinus, in Namibia

Ectoparasites were collected from Eptesicus hottentotus, the long-tailed serotine bat, caught in Namibia as part of an ecological study. Larvae of Argas transgariepinus, a blood-feeding ectoparasite of bats in Africa, were removed from 3 of 18 bats. We present scanning electron microscope images of unengorged larvae. As with other ectoparasites, this bat tick might transmit pathogens such as Borrelia and Rickettsia to their hosts as has been reported for bat ticks in Europe and North America. We screened 3 pools (25 total) of larvae of A. transgariepinus removed from the long-tailed serotine bat Eptesicus hottentotus caught in Namibia. Two microbes of unknown pathogenicity, including Rickettsia hoogstraalii, a spotted fever group pathogen, and a Rickettsiella sp. were detected by molecular techniques.

Detection and phylogenetic analysis of Bartonella species from bat flies on eastern bent-wing bats (Miniopterus fuliginosus) in Japan

We examined Bartonella prevalence in 281 bat flies collected from 114 eastern bent-wing bats (Miniopterus fuliginosus) in Japan and phylogenetically analyzed with other bat fly and bat strains. The bat flies were identified as Penicilidia jenynsii (PJ; n = 45), Nycteribia allotopa (NA; n = 157), and novel Nycteribia species (NS; n = 79). Bartonella DNAs were detected in 31.7 % (89/281) of bat flies by PCR targeting the citrate synthase (gltA) gene. The prevalence of Bartonella DNA among the bat flies was 47.1 % (74/157) in NA, 15.2 % (12/79) in NS, and 6.7 % (3/45) in PJ. Bartonella bacteria were also isolated from two NA and one NS. A phylogenetic analysis of the gltA sequences revealed that bat fly-associated strains were classified into three lineages and the same lineages of Bartonella were commonly detected from both Nycteribia bat flies and Miniopterus bats. These results suggest that Nycteribia bat flies are potential vectors for transmitting Bartonella among Miniopterus bats.

Occurrence of Bartonella genotypes in bats and associated Streblidae flies from Maranhão state, northeastern Brazil

Bartonella is a genus of emerging zoonotic bacteria that are mainly associated with mammalian erythrocytes and endothelial cells. Bats are natural reservoirs for a variety of important pathogens that impact human and animal health. Recent reports have highlighted the role of bats and bat flies in the maintenance of Bartonella. Here, we showed that none of the 29 bat DNA blood samples obtained from five bat species in São Luís Island, state of Maranhão, northeastern Brazil, were positive for Bartonella in qPCR assays targeting nuoG. On the other hand, three out of 15 DNA samples (20%) from flies in the family Streblidae were positive for Bartonella. The BLASTn results showed that the gltA and rpoB sequences shared identities ranging from 97.2% to 100%, with Bartonella sequences amplified from bats or bat flies from Costa Rica and Brazil. These findings were supported by phylogenetic analyses based on Bayesian inferences. The present study showed that Bartonella genotypes are present in bat flies, thus shedding some light on the distribution of bat fly-related Bartonella genotypes in South America.

Isolation of Candidatus Bartonella rousetti and Other Bat-associated Bartonellae from Bats and Their Flies in Zambia

Bat-associated bartonellae, including Bartonella mayotimonensis and Candidatus Bartonella rousetti, were recently identified as emerging and potential zoonotic agents, respectively. However, there is no report of bat-associated bartonellae in Zambia. Thus, we aimed to isolate and characterize Bartonella spp. from bats and bat flies captured in Zambia by culturing and PCR. Overall, Bartonella spp. were isolated from six out of 36 bats (16.7%), while Bartonella DNA was detected in nine out of 19 bat flies (47.3%). Subsequent characterization using a sequence of five different genes revealed that three isolates obtained from Egyptian fruit bats (Rousettus aegyptiacus) were Ca. B. rousetti. The isolates obtained from insectivorous bats (Macronycteris vittatus) were divided into two previously unclassified bat-associated bartonellae. A phylogenetic analysis of the six genotypes of Bartonella gltA sequences from nine pathogen-positive bat flies revealed that three genotypes belonged to the same clades as bat-associated bartonellae, including Ca. B. rousetti. The other three genotypes represented arthropod-associated bartonellae, which have previously been isolated only from ectoparasites. We demonstrated that Ca. B. rousetti is maintained between bats (R. aegyptiacus) and bat flies in Zambia. Continuous surveillance of Bartonella spp. in bats and serological surveys in humans in Africa are warranted to evaluate the public health importance of bat-associated bartonellae.

Emerging and re-emerging bacterial zoonoses in Nigeria: current preventive measures and future approaches to intervention

A characteristic of bacterial zoonoses, diseases caused by bacteria that can be transmitted to humans from animals, is a propensity to re-emerge. Several studies demonstrate their ongoing transmission in Nigeria, the most populous country in Africa. However, as local epidemiological data on bacterial zoonoses are inadequate the extent and impact of these infectious diseases is under-reported. Consequently, they are not a targeted priority of national public health policies. This limited recognition is despite indications of their possible roles in the widespread prevalence of non-malarial undifferentiated fever in Nigeria. While a number of animal reservoirs and arthropod vectors have been identified in the transmission routes of these diseases, an escalation of cases of undiagnosed febrile illness highlights the urgent need for a comprehensive assessment of other potential reservoirs, vectors and transmission cycles that may increase the local risk of infection with bacterial zoonoses. Animal health interventions have been proposed as a cost-effective strategy. Here, we present a broad overview of bacterial zoonotic infections of humans in Nigeria in the context of evolving epidemiological patterns. Further, we propose that facilitating the operation of a community-based One Health program is essential to providing the comprehensive epidemiological information that is required to improve prioritization of bacterial zoonoses. This would provide a driver for much needed investment in relevant public health interventions in Africa's most populous country.

Human Exposure to Novel Bartonella Species from Contact with Fruit Bats

Twice a year in southwestern Nigeria, during a traditional bat festival, community participants enter designated caves to capture bats, which are then consumed for food or traded. We investigated the presence of Bartonella species in Egyptian fruit bats (Rousettus aegyptiacus) and bat flies (Eucampsipoda africana) from these caves and assessed whether Bartonella infections had occurred in persons from the surrounding communities. Our results indicate that these bats and flies harbor Bartonella strains, which multilocus sequence typing indicated probably represent a novel Bartonella species, proposed as Bartonella rousetti. In serum from 8 of 204 persons, we detected antibodies to B. rousetti without cross-reactivity to other Bartonella species. This work suggests that bat-associated Bartonella strains might be capable of infecting humans.

Bat Flies and Their Microparasites: Current Knowledge and Distribution

Bats are the second most diverse mammalian group, playing keystone roles in ecosystems but also act as reservoir hosts for numerous pathogens. Due to their colonial habits which implies close contacts between individuals, bats are often parasitized by multiple species of micro- and macroparasites. The particular ecology, behavior, and environment of bat species may shape patterns of intra- and interspecific pathogen transmission, as well as the presence of specific vectorial organisms. This review synthetizes information on a multi-level parasitic system: bats, bat flies and their microparasites. Bat flies (Diptera: Nycteribiidae and Streblidae) are obligate, hematophagous ectoparasites of bats consisting of ~500 described species. Diverse parasitic organisms have been detected in bat flies including bacteria, blood parasites, fungi, and viruses, which suggest their vectorial potential. We discuss the ecological epidemiology of microparasites, their potential physiological effects on both bats and bat flies, and potential research perspectives in the domain of bat pathogens. For simplicity, we use the term microparasite throughout this review, yet it remains unclear whether some bacteria are parasites or symbionts of their bat fly hosts.

Systematic Review of Important Bacterial Zoonoses in Africa in the Last Decade in Light of the 'One Health' Concept

Zoonoses present a major public health threat and are estimated to account for a substantial part of the infectious disease burden in low-income countries. The severity of zoonotic diseases is compounded by factors such as poverty, living in close contact with livestock and wildlife, immunosuppression as well as coinfection with other diseases. The interconnections between humans, animals and the environment are essential to understand the spread and subsequent containment of zoonoses. We searched three scientific databases for articles relevant to the epidemiology of bacterial zoonoses/zoonotic bacterial pathogens, including disease prevalence and control measures in humans and multiple animal species, in various African countries within the period from 2008 to 2018. The review identified 1966 articles, of which 58 studies in 29 countries met the quality criteria for data extraction. The prevalence of brucellosis, leptospirosis, Q fever ranged from 0–40%, 1.1–24% and 0.9–28.2%, respectively, depending on geographical location and even higher in suspected outbreak cases. Risk factors for human zoonotic infection included exposure to livestock and animal slaughters. Dietary factors linked with seropositivity were found to include consumption of raw milk and locally fermented milk products. It was found that zoonoses such as leptospirosis, brucellosis, Q fever and rickettsiosis among others are frequently under/misdiagnosed in febrile patients seeking treatment at healthcare centres, leading to overdiagnoses of more familiar febrile conditions such as malaria and typhoid fever. The interactions at the human–animal interface contribute substantially to zoonotic infections. Seroprevalence of the various zoonoses varies by geographic location and species. There is a need to build laboratory capacity and effective surveillance processes for timely and effective detection and control of zoonoses in Africa. A multifaceted ‘One Health’ approach to tackle zoonoses is critical in the fight against zoonotic diseases. The impacts of zoonoses include: (1) Humans are always in contact with animals including livestock and zoonoses are causing serious life-threatening infections in humans. Almost 75% of the recent major global disease outbreaks have a zoonotic origin. (2) Zoonoses are a global health challenge represented either by well-known or newly emerging zoonotic diseases. (3) Zoonoses are caused by all-known cellular (bacteria, fungi and parasites) and noncellular (viruses or prions) pathogens. (4) There are limited data on zoonotic diseases from Africa. The fact that human health and animal health are inextricably linked, global coordinated and well-established interdisciplinary research efforts are essential to successfully fight and reduce the health burden due to zoonoses. This critically requires integrated data from both humans and animals on zoonotic diseases.

Isolation and Identification of a Highly Divergent Kaeng Khoi Virus from Bat Flies (Eucampsipoda sundaica) in China

BACKGROUND

Kaeng Khoi virus (KKV), which belongs to the genus Orthobunyavirus, family Perbunyaviridae, was originally isolated from the brain tissue of bats and may cause infection in humans. In this study, the KKV strain WDBC1403 was isolated from bat flies (Eucampsipoda sundaica), ectoparasites of the bat Rousettus leschenaultia, collected from Yunnan Province of China at the Sino-Burmese border.

METHODS AND RESULTS

The bat fly specimens were ground and inoculated in culture cells. The WDBC1403 strain was shown to induce cytopathic effects in Vero, baby hamster kidney (BHK-21), and Tb1Lu cells, but not in C6/36 cells; however, viral gene amplification was detected in the supernatants of C6/36 cells. Using electron microscopy, the virus was determined to be spherical, enveloped, and 80-90 nm in diameter; it was also shown to form plaques in BHK-21 cells and the titer reached 1 × 10^6.57 plaque-forming units/mL 24 h after infection. The phylogenetic analysis showed that WDBC1403 is a KKV strain, but is independent of the original KKV strain (PSC-19). Viral genome analysis revealed that the nucleotide and amino acid sequence identities of the S, M, and L segments of WDBC1403 with PSC-19 were 88.2% and 96.1%, 76.7% and 85.0%, and 78.3% and 88.9%, respectively. Two amino acids were removed at the end of the open reading frame of the M segment, and 47 nucleotides were removed in the 3'-untranslated region of the M segment of the WDBC1403 strain compared with the PSC-19 strain.

CONCLUSIONS

The WDBC1403 strain is a highly divergent KKV strain, suggesting that there are a variety of KKV strains that exhibit molecular differences. Moreover, because of the large variations in nucleotide and amino acid sequence in the M segment, which encodes an important membrane protein, further research on antigenicity and pathogenicity in humans and animals is needed.

Eco-epidemiology of Novel Bartonella Genotypes from Parasitic Flies of Insectivorous Bats

Bats are important zoonotic reservoirs for many pathogens worldwide. Although their highly specialized ectoparasites, bat flies (Diptera: Hippoboscoidea), can transmit Bartonella bacteria including human pathogens, their eco-epidemiology is unexplored. Here, we analyzed the prevalence and diversity of Bartonella strains sampled from 10 bat fly species from 14 European bat species. We found high prevalence of Bartonella spp. in most bat fly species with wide geographical distribution. Bat species explained most of the variance in Bartonella distribution with the highest prevalence of infected flies recorded in species living in dense groups exclusively in caves. Bat gender but not bat fly gender was also an important factor with the more mobile male bats giving more opportunity for the ectoparasites to access several host individuals. We detected high diversity of Bartonella strains (18 sequences, 7 genotypes, in 9 bat fly species) comparable with tropical assemblages of bat-bat fly association. Most genotypes are novel (15 out of 18 recorded strains have a similarity of 92-99%, with three sequences having 100% similarity to Bartonella spp. sequences deposited in GenBank) with currently unknown pathogenicity; however, 4 of these sequences are similar (up to 92% sequence similarity) to Bartonella spp. with known zoonotic potential. The high prevalence and diversity of Bartonella spp. suggests a long shared evolution of these bacteria with bat flies and bats providing excellent study targets for the eco-epidemiology of host-vector-pathogen cycles.

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.

Acquisition of Bartonella elizabethae by Experimentally Exposed Oriental Rat Fleas (Xenopsylla cheopis; Siphonaptera, Pulicidae) and Excretion of Bartonella DNA in Flea Feces

Few studies have been able to provide experimental evidence of the ability of fleas to maintain rodent-associated Bartonella infections and excrete these bacteria. These data are important for understanding the transmission cycles and prevalence of these bacteria in hosts and vectors. We used an artificial feeding approach to expose groups of the oriental rat flea (Xenopsylla cheopis Rothschild; Siphonaptera, Pulicidae) to rat blood inoculated with varying concentrations of Bartonella elizabethae Daly (Bartonellaceae: Rhizobiales). Flea populations were maintained by membrane feeding on pathogen-free bloodmeals for up to 13 d post infection. Individual fleas and pools of flea feces were tested for the presence of Bartonella DNA using molecular methods (quantitative and conventional polymerase chain reaction [PCR]). The threshold number of Bartonellae required in the infectious bloodmeal for fleas to be detected as positive was 106 colony-forming units per milliliter (CFU/ml). Individual fleas were capable of harboring infections for at least 13 d post infection and continuously excreted Bartonella DNA in their feces over the same period. This experiment demonstrated that X. cheopis are capable of acquiring and excreting B. elizabethae over several days. These results will guide future work to model and understand the role of X. cheopis in the natural transmission cycle of rodent-borne Bartonella species. Future experiments using this artificial feeding approach will be useful for examining the horizontal transmission of B. elizabethae or other rodent-associated Bartonella species to naïve hosts and for determining the viability of excreted bacteria.

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.

Molecular detection of Bartonella spp. and Rickettsia spp. in bat ectoparasites in Brazil

The family Streblidae comprises a monophyletic group of Hippoboscoidea, hematophagous dipterans that parasitize bats. Bartonella spp. and Rickettsia spp. have been reported in bats sampled in Europe, Africa, Asia, North, Central and South America. However, there are few reports on the Bartonella and Rickettsia bacteria infecting Hippoboscoidea flies and mites. While Spinturnicidae mites are ectoparasites found only in bats, those belonging to the family Macronyssidae comprise mites that also parasitize other mammal species. This study investigates the occurrence and assesses the phylogenetic positioning of Bartonella spp. and Rickettsia spp. found in Streblidae flies and Spinturnicidae and Macronyssidae mites collected from bats captured in Brazil. From May 2011 to April 2012 and September 2013 to December 2014, 400 Streblidae flies, 100 Macronyssidaes, and 100 Spinturnicidae mites were collected from bats captured in two sites in northeastern Nova Iguaçu, Rio de Janeiro, southeastern Brazil. Forty (19.8%) out of 202 Streblidae flies were positive for Bartonella spp. in qPCR assays based on the nuoG gene. Among the flies positive for the bacterium, six (18%) were Paratrichobius longicrus, seven (29%) Strebla guajiro, two (40%) Aspidoptera phyllostomatis, five (11%) Aspidoptera falcata, one (10%) Trichobius anducei, one (25%) Megistopoda aranea, and 18 (32%) Trichobius joblingi, and collected from bats of the following species: Artibeus lituratus, Carollia perspicillata, Artibeus planirostris, Sturnira lilium, and Artibeus obscurus. Six sequences were obtained for Bartonella (nuoG [n = 2], gltA [n = 2], rpoB [n = 1], ribC = 1]). The phylogenetic analysis based on gltA (750pb) gene showed that the Bartonella sequences clustered with Bartonella genotypes detected in bats and ectoparasites previously sampled in Latin America, including Brazil. Only one sample (0.49%) of the species Trichobius joblingi collected from a specimen of Carollia perspicillata was positive for Rickettsia sp. in cPCR based on the gltA gene (401bp). This sequence was clustered with a 'Candidatus Rickettsia andaenae" genotype detected in an Amblyomma parvum tick collected from a rodent in the southern region of Brazilian Pantanal. The sampled Macronyssidae and Spinturnicidae mites were negative for Bartonella spp. and Rickettsia spp. This study demonstrated the first occurrence of Bartonella spp. and Rickettsia spp. DNA in Streblidae flies collected from bats in Brazil.

Molecular Detection of Bartonella Species in Blood-Feeding Bat Flies from Mexico

Bartonellae are emerging blood-borne bacteria that have been recovered from a wide range of mammalian species and arthropod vectors around the world. Bats are now recognized as a potential wildlife reservoir for a diverse number of Bartonella species, including the zoonotic Candidatus B. mayotimonensis. These bat-borne Bartonella species have also been detected in the obligate ectoparasites of bats, such as blood-feeding flies, which could transmit these bacteria within bat populations. To better understand this potential for transmission, we investigated the relatedness between Bartonella detected or isolated from bat hosts sampled in Mexico and their ectoparasites. Bartonella spp. were identified in bat flies collected on two bat species, with the highest prevalence in Trichobius parasiticus and Strebla wiedemanni collected from common vampire bats (Desmodus rotundus). When comparing Bartonella sequences from a fragment of the citrate synthase gene (gltA), vector-associated strains were diverse and generally close to, but distinct from, those recovered from their bacteremic bat hosts in Mexico. Complete Bartonella sequence concordance was observed in only one bat-vector pair. The diversity of Bartonella strains in bat flies reflects the frequent host switch by bat flies, as they usually do not live permanently on their bat host. It may also suggest a possible endosymbiotic relationship with these vectors for some of the Bartonella species carried by bat flies, whereas others could have a mammalian host.

Survey of Parasitic Bacteria in Bat Bugs, Colorado

Bat bugs (Cimex adjunctus Barber) (Hemiptera: Cimicidae) collected from big brown bats (Eptesicus fuscus Palisot de Beauvoir) in Colorado, United States were assessed for the presence of Bartonella, Brucella, and Yersinia spp. using molecular techniques. No evidence of Brucella or Yersinia infection was found in the 55 specimens collected; however, 4/55 (7.3%) of the specimens were positive for Bartonella DNA. Multi-locus characterization of Bartonella DNA shows that sequences in bat bugs are phylogenetically related to other Bartonella isolates and sequences from European bats.

Bartonella, bats and bugs: A review

Ecological, immunological, and epidemiological factors enable bats to transmit an increasingly recognized spectrum of zoonotic agents, and bartonellae are among those emerging pathogens identified in bats and their arthropod ectoparasites. Current data reveal a multifaceted disease ecology where diverse host species distributed around the world interact with a number of Bartonella spp. and several potential vectors. This review summarizes the methods and findings of studies conducted since 2005 to illustrate that Bartonella bacteremia varies by bat species, location, and other potential variables, such as diet with a very high prevalence in hematophagous bats. Among bat families, Bartonella prevalence ranged from 7.3% among Nycteridae to 54.4% in Miniopteridae. Further research can build on these current data to better determine risk factors associated with Bartonella infection in bat populations and the role of their ectoparasites in transmission.

Diversity and phylogenetic relationships among Bartonella strains from Thai bats

Bartonellae are phylogenetically diverse, intracellular bacteria commonly found in mammals. Previous studies have demonstrated that bats have a high prevalence and diversity of Bartonella infections globally. Isolates (n = 42) were obtained from five bat species in four provinces of Thailand and analyzed using sequences of the citrate synthase gene (gltA). Sequences clustered into seven distinct genogroups; four of these genogroups displayed similarity with Bartonella spp. sequences from other bats in Southeast Asia, Africa, and Eastern Europe. Thirty of the isolates representing these seven genogroups were further characterized by sequencing four additional loci (ftsZ, nuoG, rpoB, and ITS) to clarify their evolutionary relationships with other Bartonella species and to assess patterns of diversity among strains. Among the seven genogroups, there were differences in the number of sequence variants, ranging from 1-5, and the amount of nucleotide divergence, ranging from 0.035-3.9%. Overall, these seven genogroups meet the criteria for distinction as novel Bartonella species, with sequence divergence among genogroups ranging from 6.4-15.8%. Evidence of intra- and intercontinental phylogenetic relationships and instances of homologous recombination among Bartonella genogroups in related bat species were found in Thai bats.

Bartonella Infection in Hematophagous, Insectivorous, and Phytophagous Bat Populations of Central Mexico and the Yucatan Peninsula

Although emerging nonviral pathogens remain relatively understudied in bat populations, there is an increasing focus on identifying bat-associated bartonellae around the world. Many novel Bartonella strains have been described from both bats and their arthropod ectoparasites, including Bartonella mayotimonensis, a zoonotic agent of human endocarditis. This cross-sectional study was designed to describe novel Bartonella strains isolated from bats sampled in Mexico and evaluate factors potentially associated with infection. A total of 238 bats belonging to seven genera were captured in five states of Central Mexico and the Yucatan Peninsula. Animals were screened by bacterial culture from whole blood and/or polymerase chain reaction of DNA extracted from heart tissue or blood. Bartonella spp. were isolated or detected in 54 (22.7%) bats, consisting of 41 (38%) hematophagous, 10 (16.4%) insectivorous, and three (4.3%) phytophagous individuals. This study also identified Balantiopteryx plicata as another possible bat reservoir of Bartonella. Univariate and multivariate logistic regression models suggested that Bartonella infection was positively associated with blood-feeding diet and ectoparasite burden. Phylogenetic analysis identified a number of genetic variants across hematophagous, phytophagous, and insectivorous bats that are unique from described bat-borne Bartonella species. However, these strains were closely related to those bartonellae previously identified in bat species from Latin America.

Bacterial arthropod-borne diseases in West Africa

Arthropods such as ticks, lice, fleas and mites are excellent vectors for many pathogenic agents including bacteria, protozoa and viruses to animals. Moreover, many of these pathogens can also be accidentally transmitted to humans throughout the world. Bacterial vector-borne diseases seem to be numerous and very important in human pathology, however, they are often ignored and are not well known. Yet they are in a phase of geographic expansion and play an important role in the etiology of febrile episodes in regions of Africa. Since the introduction of molecular techniques, the presence of these pathogens has been confirmed in various samples from arthropods and animals, and more rarely from human samples in West Africa. In this review, the aim is to summarize the latest information about vector-borne bacteria, focusing on West Africa from 2000 until today in order to better understand the epidemiological risks associated with these arthropods. This will allow health and veterinary authorities to develop a strategy for surveillance of arthropods and bacterial disease in order to protect people and animals.

Isolation of Kaeng Khoi virus (KKV) from Eucampsipoda sundaica bat flies in China

A virus strain (WDBC1210) was isolated from specimens of bat flies (Eucampsipoda sundaica) associated with Leschenault's Rousette (Rousettus leschenaultii) in the China-Myanmar border area of Yunnan Province, China. Both BHK-21 and VeroE6 cells infected with WDBC1210 showed evident cytopathic effects (CPE), and the highest propagation titer was 1×10^5.6. The virus particles were spherical, 70nm in diameter. Virus plaques could be observed in BHK-21 cells. The whole genome of WDBC1210 contained three RNA segments: the small gene (S), 975 nucleotides long; the medium gene (M), 4568 nucleotides long; and the large gene (L), 6866 nucleotides long. The nucleotide homologies of the S, M, and L genes between WDBC1210 and the original isolate of Kaeng Khoi virus (KKV; PSC-19 strain) were 96.9%, 94.1%, and 95.2%, respectively. Phylogenetic analyses based on the S, M, and L segments indicated that WDBC1210 belongs within the same clade as the KKV strain PSC-19, a member of the Bunyaviridae family. This is the first report on the isolation of KKV from bat flies (Eucampsipoda sundaica) and from an inland area, nearly 2000km north from the original isolation site of KKV in Thailand, suggesting that KKV virus not only has a diverse set of vectors, but also a wide geographic distribution.

Diversity and role of cave-dwelling hematophagous insects in pathogen transmission in the Afrotropical region

The progressive anthropization of caves for food resources or economic purposes increases human exposure to pathogens that naturally infect cave-dwelling animals. The presence of wild or domestic animals in the immediate surroundings of caves also may contribute to increasing the risk of emergence of such pathogens. Some zoonotic pathogens are transmitted through direct contact, but many others require arthropod vectors, such as blood-feeding insects. In Africa, hematophagous insects often play a key role in the epidemiology of many pathogens; however, their ecology in cave habitats remains poorly known. During the last decades, several investigations carried out in Afrotropical caves suggested the medical and veterinary importance particularly of insect taxa of the Diptera order. Therefore, the role of some of these insects as vectors of pathogens that infect cave-dwelling vertebrates has been studied. The present review summarizes these findings, brings insights into the diversity of cave-dwelling hematophagous Diptera and their involvement in pathogen transmission, and finally discusses new challenges and future research directions.

Novel Bartonella Species in Insectivorous Bats, Northern China

Bartonella species are emerging human pathogens. Bats are known to carry diverse Bartonella species, some of which are capable of infecting humans. However, as the second largest mammalian group by a number of species, the role of bats as the reservoirs of Bartonella species is not fully explored, in term of their species diversity and worldwide distribution. China, especially Northern China, harbors a number of endemic insectivorous bat species; however, to our knowledge, there are not yet studies about Bartonella in bats in China. The aim of the study was to investigate the prevalence and genetic diversity of Bartonella species in bats in Northern China. Bartonella species were detected by PCR amplification of gltA gene in 25.2% (27/107) bats in Mengyin County, Shandong Province of China, including 1/3 Rhinolophus ferrumequinum, 2/10 Rhinolophus pusillus, 9/16 Myotis fimbriatus, 1/5 Myotis ricketti, 14/58 Myotis pequinius. Phylogenetic analysis showed that Bartonella species detected in bats in this study clustered into ten groups, and some might be novel Bartonella species. An association between Bartonella species and bat species was demonstrated and co-infection with different Bartonella species in a single bat was also observed. Our findings expanded our knowledge on the genetic diversity of Bartonella in bats, and shed light on the ecology of bat-borne Bartonella species.

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.

Ecology of Bats, Their Ectoparasites, and Associated Pathogens on Saint Kitts Island

Ectoparasites of bats and bat-associated pathogens are poorly studied in the Lesser Antilles Islands. We report on an 11-mo field study on Saint Kitts Island of bat populations, their associated ectoparasites, and pathogens. We report on five ectoparasite species, including four Streblidae (Diptera) and a Spinturnicidae (Acari). Several genotypes of unnamed Bartonella were isolated from bats and ectoparasites. Microfilaria of an undetermined Litomosoides spp. were detected in blood from Artibeus jamaicensis Leach (Chiroptera: Phyllostomidae) (and associated ectoparasites: Trichobius intermedius Peterson and Hurka (Diptera: Streblidae) and Periglischrus iheringi Oudemans (Acari: Spinturnicidae)). In addition, an Ehrlichia sp. and Rickettsia africae were detected in the blood of several bat species. Our study is one of the first surveys of ectoparasite-borne pathogens in wild mammals from St. Kitts.

Bat trait, genetic and pathogen data from large-scale investigations of African fruit bats, Eidolon helvum

Bats, including African straw-coloured fruit bats (Eidolon helvum), have been highlighted as reservoirs of many recently emerged zoonotic viruses. This common, widespread and ecologically important species was the focus of longitudinal and continent-wide studies of the epidemiological and ecology of Lagos bat virus, henipaviruses and Achimota viruses. Here we present a spatial, morphological, demographic, genetic and serological dataset encompassing 2827 bats from nine countries over an 8-year period. Genetic data comprises cytochrome b mitochondrial sequences (n=608) and microsatellite genotypes from 18 loci (n=544). Tooth-cementum analyses (n=316) allowed derivation of rare age-specific serologic data for a lyssavirus, a henipavirus and two rubulaviruses. This dataset contributes a substantial volume of data on the ecology of E. helvum and its viruses and will be valuable for a wide range of studies, including viral transmission dynamic modelling in age-structured populations, investigation of seasonal reproductive asynchrony in wide-ranging species, ecological niche modelling, inference of island colonisation history, exploration of relationships between island and body size, and various spatial analyses of demographic, morphometric or serological data.

Diversity of Bartonella and Rickettsia spp. in Bats and Their Blood-Feeding Ectoparasites from South Africa and Swaziland

In addition to several emerging viruses, bats have been reported to host multiple bacteria but their zoonotic threats remain poorly understood, especially in Africa where the diversity of bats is important. Here, we investigated the presence and diversity of Bartonella and Rickettsia spp. in bats and their ectoparasites (Diptera and Siphonaptera) collected across South Africa and Swaziland. We collected 384 blood samples and 14 ectoparasites across 29 different bat species and found positive samples in four insectivorous and two frugivorous bat species, as well as their Nycteribiidae flies. Phylogenetic analyses revealed diverse Bartonella genotypes and one main group of Rickettsia, distinct from those previously reported in bats and their ectoparasites, and for some closely related to human pathogens. Our results suggest a differential pattern of host specificity depending on bat species. Bartonella spp. identified in bat flies and blood were identical supporting that bat flies may serve as vectors. Our results represent the first report of bat-borne Bartonella and Rickettsia spp. in these countries and highlight the potential role of bats as reservoirs of human bacterial pathogens.

The Bacteriome of Bat Flies (Nycteribiidae) from the Malagasy Region: a Community Shaped by Host Ecology, Bacterial Transmission Mode, and Host-Vector Specificity

The Nycteribiidae are obligate blood-sucking Diptera (Hippoboscoidea) flies that parasitize bats. Depending on species, these wingless flies exhibit either high specialism or generalism toward their hosts, which may in turn have important consequences in terms of their associated microbial community structure. Bats have been hypothesized to be reservoirs of numerous infectious agents, some of which have recently emerged in human populations. Thus, bat flies may be important in the epidemiology and transmission of some of these bat-borne infectious diseases, acting either directly as arthropod vectors or indirectly by shaping pathogen communities among bat populations. In addition, bat flies commonly have associations with heritable bacterial endosymbionts that inhabit insect cells and depend on maternal transmission through egg cytoplasm to ensure their transmission. Some of these heritable bacteria are likely obligate mutualists required to support bat fly development, but others are facultative symbionts with unknown effects. Here, we present bacterial community profiles that were obtained from seven bat fly species, representing five genera, parasitizing bats from the Malagasy region. The observed bacterial diversity includes Rickettsia, Wolbachia, and several Arsenophonus-like organisms, as well as other members of the Enterobacteriales and a widespread association of Bartonella bacteria from bat flies of all five genera. Using the well-described host specificity of these flies and data on community structure from selected bacterial taxa with either vertical or horizontal transmission, we show that host/vector specificity and transmission mode are important drivers of bacterial community structure.

Bartonella spp. in a Puerto Rican bat community

We captured and sampled 68 bats of six species from a shared roosting site in Puerto Rico in April 2012. Bats were screened for Bartonella spp. by culture and confirmed by PCR and sequencing for the gltA gene. Bartonella cultures were obtained from blood specimens of 9/51 (18%) individuals from three species (Artibeus jamaicensis, Brachyphylla cavernarum, and Monophyllus redmani). Phylogenetic analysis of the gltA sequences showed that M. redmani was infected with multiple, diverse Bartonella strains, and A. jamaicensis was infected with a strain related to a strain from a congeneric host. Ectoparasite load could possibly explain observed differences in Bartonella diversity and prevalence between bat species in this community, and we suggest future research to substantiate these preliminary findings.

Immunology of bats and their viruses: challenges and opportunities

Bats are reservoir hosts of several high-impact viruses that cause significant human diseases, including Nipah virus, Marburg virus and rabies virus. They also harbor many other viruses that are thought to have caused disease in humans after spillover into intermediate hosts, including SARS and MERS coronaviruses. As is usual with reservoir hosts, these viruses apparently cause little or no pathology in bats. Despite the importance of bats as reservoir hosts of zoonotic and potentially zoonotic agents, virtually nothing is known about the host/virus relationships; principally because few colonies of bats are available for experimental infections, a lack of reagents, methods and expertise for studying bat antiviral responses and immunology, and the difficulty of conducting meaningful field work. These challenges can be addressed, in part, with new technologies that are species-independent that can provide insight into the interactions of bats and viruses, which should clarify how the viruses persist in nature, and what risk factors might facilitate transmission to humans and livestock.