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Infection, Genetics and Evolution :... Oct 2016The influence of factors contributing to parasite diversity in individual hosts and communities are increasingly studied, but there has been less focus on the dominant...
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.
Topics: Adaptation, Biological; Animals; Bartonella; Bayes Theorem; Chiroptera; Genetic Variation; Genotype; Host-Parasite Interactions; Phylogeny; Phylogeography; Species Specificity
PubMed: 27473781
DOI: 10.1016/j.meegid.2016.07.033 -
Molecular Biology and Evolution Sep 2021Emergence of resistant bacteria during antimicrobial treatment is one of the most critical and universal health threats. It is known that several stress-induced...
Emergence of resistant bacteria during antimicrobial treatment is one of the most critical and universal health threats. It is known that several stress-induced mutagenesis and heteroresistance mechanisms can enhance microbial adaptation to antibiotics. Here, we demonstrate that the pathogen Bartonella can undergo stress-induced mutagenesis despite the fact it lacks error-prone polymerases, the rpoS gene and functional UV-induced mutagenesis. We demonstrate that Bartonella acquire de novo single mutations during rifampicin exposure at suprainhibitory concentrations at a much higher rate than expected from spontaneous fluctuations. This is while exhibiting a minimal heteroresistance capacity. The emerged resistant mutants acquired a single rpoB mutation, whereas no other mutations were found in their whole genome. Interestingly, the emergence of resistance in Bartonella occurred only during gradual exposure to the antibiotic, indicating that Bartonella sense and react to the changing environment. Using a mathematical model, we demonstrated that, to reproduce the experimental results, mutation rates should be transiently increased over 1,000-folds, and a larger population size or greater heteroresistance capacity is required. RNA expression analysis suggests that the increased mutation rate is due to downregulation of key DNA repair genes (mutS, mutY, and recA), associated with DNA breaks caused by massive prophage inductions. These results provide new evidence of the hazard of antibiotic overuse in medicine and agriculture.
Topics: Anti-Bacterial Agents; Bartonella; Mutagenesis; Mutation; Rifampin; SOS Response, Genetics
PubMed: 34175952
DOI: 10.1093/molbev/msab196 -
FEMS Microbiology Reviews May 2012Bartonella spp. are facultative intracellular bacteria that typically cause a long-lasting intraerythrocytic bacteremia in their mammalian reservoir hosts, thereby... (Review)
Review
Bartonella spp. are facultative intracellular bacteria that typically cause a long-lasting intraerythrocytic bacteremia in their mammalian reservoir hosts, thereby favoring transmission by blood-sucking arthropods. In most cases, natural reservoir host infections are subclinical and the relapsing intraerythrocytic bacteremia may last weeks, months, or even years. In this review, we will follow the infection cycle of Bartonella spp. in a reservoir host, which typically starts with an intradermal inoculation of bacteria that are superficially scratched into the skin from arthropod feces and terminates with the pathogen exit by the blood-sucking arthropod. The current knowledge of bacterial countermeasures against mammalian immune response will be presented for each critical step of the pathogenesis. The prevailing models of the still-enigmatic primary niche and the anatomical location where bacteria reside, persist, and are periodically seeded into the bloodstream to cause the typical relapsing Bartonella spp. bacteremia will also be critically discussed. The review will end up with a discussion of the ability of Bartonella spp., namely Bartonella henselae, Bartonella quintana, and Bartonella bacilliformis, to induce tumor-like vascular deformations in humans having compromised immune response such as in patients with AIDS.
Topics: Animals; Arthropods; Asymptomatic Infections; Bacteremia; Bartonella Infections; Bartonella bacilliformis; Bartonella henselae; Bartonella quintana; Chronic Disease; Disease Vectors; Host-Pathogen Interactions; Humans; Zoonoses
PubMed: 22229763
DOI: 10.1111/j.1574-6976.2012.00324.x -
Veterinaria Italiana Apr 2020Cat scratch disease (CSD) is a zoonotic disease, caused predominantly by Bartonella henselae and transmitted to humans through a scratch or bite of the cat. Cat...
Cat scratch disease (CSD) is a zoonotic disease, caused predominantly by Bartonella henselae and transmitted to humans through a scratch or bite of the cat. Cat represents the principal reservoir and healthy carrier of Bartonella, which is mainly transmitted, among cats, by the flea Ctenocephalides felis. During 2014, fifty‑two samples of whole blood and sera were collected randomly from cats in Abruzzo region and were examined by real-time PCR and IFAT tests, respectively. Seven samples out of fifty‑two (13.5%) resulted positive for Bartonella spp. in both tests, while six specimens (11.5%) resulted real-time PCR negative but IgG positive; thirty‑nine were instead both real-time PCR and IFAT negative (75%). Sequence analysis of a fragment of DNA identified B. henselae and B. clarridgeiae in four and in two real‑time PCR positive samples, respectively.
Topics: Animals; Bartonella henselae; Cat Diseases; Cat-Scratch Disease; Cats; Ctenocephalides; Fluorescent Antibody Technique, Indirect; Italy; Real-Time Polymerase Chain Reaction; Zoonoses
PubMed: 32343095
DOI: 10.12834/VetIt.1884.10006.2 -
Parasitology Sep 2023Many organisms live in fragmented populations, which has profound consequences on the dynamics of associated parasites. Metapopulation theory offers a canonical...
Many organisms live in fragmented populations, which has profound consequences on the dynamics of associated parasites. Metapopulation theory offers a canonical framework for predicting the effects of fragmentation on spatiotemporal host–parasite dynamics. However, empirical studies of parasites in classical metapopulations remain rare, particularly for vector-borne parasites. Here, we quantify spatiotemporal patterns and possible drivers of infection probability for several ectoparasites (fleas, and ) and vector-borne microparasites (, spp., spp.) in a classically functioning metapopulation of water vole hosts. Results suggest that the relative importance of vector or host dynamics on microparasite infection probabilities is related to parasite life-histories. , a microparasite with a fast life-history, was positively associated with both host and vector abundances at several spatial and temporal scales. In contrast, , a tick-borne parasite with a slow life-history, was only associated with vector dynamics. Further, we provide evidence that life-history shaped parasite dynamics, including occupancy and colonization rates, in the metapopulation. Lastly, our findings were consistent with the hypothesis that landscape connectivity was determined by distance-based dispersal of the focal hosts. We provide essential empirical evidence that contributes to the development of a comprehensive theory of metapopulation processes of vector-borne parasites.
Topics: Animals; Bartonella; Flea Infestations; Ixodes; Siphonaptera
PubMed: 37519240
DOI: 10.1017/S0031182023000677 -
Veterinary Research 2009Bartonella spp. are facultative intracellular bacteria that cause characteristic hostrestricted hemotropic infections in mammals and are typically transmitted by... (Review)
Review
Bartonella spp. are facultative intracellular bacteria that cause characteristic hostrestricted hemotropic infections in mammals and are typically transmitted by blood-sucking arthropods. In the mammalian reservoir, these bacteria initially infect a yet unrecognized primary niche, which seeds organisms into the blood stream leading to the establishment of a long-lasting intra-erythrocytic bacteremia as the hall-mark of infection. Bacterial type IV secretion systems, which are supra-molecular transporters ancestrally related to bacterial conjugation systems, represent crucial pathogenicity factors that have contributed to a radial expansion of the Bartonella lineage in nature by facilitating adaptation to unique mammalian hosts. On the molecular level, the type IV secretion system VirB/VirD4 is known to translocate a cocktail of different effector proteins into host cells, which subvert multiple cellular functions to the benefit of the infecting pathogen. Furthermore, bacterial adhesins mediate a critical, early step in the pathogenesis of the bartonellae by binding to extracellular matrix components of host cells, which leads to firm bacterial adhesion to the cell surface as a prerequisite for the efficient translocation of type IV secretion effector proteins. The best-studied adhesins in bartonellae are the orthologous trimeric autotransporter adhesins, BadA in Bartonella henselae and the Vomp family in Bartonella quintana. Genetic diversity and strain variability also appear to enhance the ability of bartonellae to invade not only specific reservoir hosts, but also accidental hosts, as shown for B. henselae. Bartonellae have been identified in many different blood-sucking arthropods, in which they are typically found to cause extracellular infections of the mid-gut epithelium. Adaptation to specific vectors and reservoirs seems to be a common strategy of bartonellae for transmission and host diversity. However, knowledge regarding arthropod specificity/restriction, the mode of transmission, and the bacterial factors involved in arthropod infection and transmission is still limited.
Topics: Adaptation, Physiological; Animals; Bartonella; Disease Reservoirs; Ecosystem; Humans; Insect Vectors; Insecta
PubMed: 19284965
DOI: 10.1051/vetres/2009011 -
Parasites & Vectors Jan 2020Bartonella is a genus of Gram-negative facultative intracellular Alphaproteobacteria of public health importance. Although they are known to mainly infect mammalian...
BACKGROUND
Bartonella is a genus of Gram-negative facultative intracellular Alphaproteobacteria of public health importance. Although they are known to mainly infect mammalian hosts with some blood-feeding arthropods having been confirmed as vectors, there is some evidence of Bartonella association with non-mammalian hosts including birds.
METHODS
Here we used high-throughput sequencing of 16S rRNA and Sanger sequencing of the citrate synthase (gltA) genes to test for the presence of Bartonellaceae in the blood of three migratory cavity nesting bird species, purple martins (Progne subis), tree swallows (Tachycineta bicolor) and eastern bluebirds (Sialia sialis) and their most prevalent and abundant nest ectoparasites, Dermanyssus prognephilus (mite), Ceratophyllus idius (flea) and Protocalliphora sialia (bird blow fly larva). We constructed maximum likelihood phylogenetic trees to verify the placement of the resulting sequences in the Bartonellaceae.
RESULTS
We found evidence of Bartonella in all three bird species and all three arthropod species tested. We report multiple instances of identical Bartonella sequences in both birds and parasites, leading to the likely hypothesis that these ectoparasites are potential vectors of Bartonella. Our phylogenetic analysis suggests that 'avian Bartonella' may form its own sub-clade within the genus Bartonella.
CONCLUSIONS
To the best of our knowledge, we provide the first confirmation of overlapping Bartonella strains among bird hosts and various species of nest-associated ectoparasites from the same system, suggesting a possible Bartonella host-vector relationship between these arthropods and a non-mammalian host. Our study adds to the growing appreciation of the Bartonellaceae as a phylogenetically diverse group with a wide range of hosts.
Topics: Animals; Arachnid Vectors; Bartonella; Bartonella Infections; Birds; Citrate (si)-Synthase; Diptera; Ectoparasitic Infestations; Genes, Bacterial; Insect Vectors; Metagenomics; Mites; Phylogeny; RNA, Ribosomal, 16S; Siphonaptera
PubMed: 31924262
DOI: 10.1186/s13071-020-3896-7 -
Genome Biology and Evolution Nov 2018Bartonella is a genetically diverse group of vector-borne bacteria. Over 40 species have been characterized to date, mainly from mammalian reservoirs and arthropod...
Bartonella is a genetically diverse group of vector-borne bacteria. Over 40 species have been characterized to date, mainly from mammalian reservoirs and arthropod vectors. Rodent reservoirs harbor one of the largest Bartonella diversity described to date, and novel species and genetic variants are continuously identified from these hosts. Yet, it is still unknown if this significant genetic diversity stems from adaptation to different niches or from intrinsic high mutation rates. Here, we explored the vertical occurrence of spontaneous genomic alterations in 18 lines derived from two rodent-associated Bartonella elizabethae-like strains, evolved in nonselective agar plates under conditions mimicking their vector- and mammalian-associated temperatures, and the transmission cycles between them (i.e., 26 °C, 37 °C, and alterations between the two), using mutation accumulation experiments. After ∼1,000 generations, evolved genomes revealed few point mutations (average of one-point mutation per line), evidencing conserved single-nucleotide mutation rates. Interestingly, three large structural genomic changes (two large deletions and an inversion) were identified over all lines, associated with prophages and surface adhesin genes. Particularly, a prophage, deleted during constant propagation at 37 °C, was associated with an increased autonomous replication at 26 °C (the flea-associated temperature). Complementary molecular analyses of wild strains, isolated from desert rodents and their fleas, further supported the occurrence of structural genomic variations and prophage-associated deletions in nature. Our findings suggest that structural genomic changes represent an effective intrinsic mechanism to generate diversity in slow-growing bacteria and emphasize the role of prophages as promoters of diversity in nature.
Topics: Bartonella; Biological Evolution; Genome, Bacterial; Genomic Structural Variation; Multigene Family; Prophages
PubMed: 30346520
DOI: 10.1093/gbe/evy236 -
Emerging Infectious Diseases Mar 2006Among the many mammals infected with Bartonella spp., pets represent a large reservoir for human infection because most Bartonella spp. infecting them are zoonotic. Cats... (Review)
Review
Among the many mammals infected with Bartonella spp., pets represent a large reservoir for human infection because most Bartonella spp. infecting them are zoonotic. Cats are the main reservoir for Bartonella henselae, B. clarridgeiae, and B. koehlerae. Dogs can be infected with B. vinsonii subsp. berkhoffii, B. henselae, B. clarridgeiae, B. washoensis, B. elizabethae, and B. quintana. The role of dogs as an important reservoir of Bartonella spp. is less clear than for cats because domestic dogs are more likely to be accidental hosts, at least in nontropical regions. Nevertheless, dogs are excellent sentinels for human infections because a similar disease spectrum develops in dogs. Transmission of B. henselae by cat fleas is better understood, although new potential vectors (ticks and biting flies) have been identified. We review current knowledge on the etiologic agents, clinical features, and epidemiologic characteristics of these emerging zoonoses.
Topics: Animals; Animals, Domestic; Bartonella; Bartonella Infections; Disease Reservoirs; Humans; Insect Vectors; Zoonoses
PubMed: 16704774
DOI: 10.3201/eid1203.050931 -
Infection, Genetics and Evolution :... Apr 2021Bats are notorious reservoirs of several zoonotic diseases and may be uniquely tolerant of infection among mammals. Broad sampling has revealed the importance of bats in...
Bats are notorious reservoirs of several zoonotic diseases and may be uniquely tolerant of infection among mammals. Broad sampling has revealed the importance of bats in the diversification and spread of viruses and eukaryotes to other animal hosts. Vector-borne bacteria of the genus Bartonella are prevalent and diverse in mammals globally and recent surveys have revealed numerous Bartonella lineages in bats. We assembled a sequence database of Bartonella strains, consisting of nine genetic loci from 209 previously characterized Bartonella lineages and 121 new cultured isolates from bats, and used these data to perform a comprehensive phylogenetic analysis of the Bartonella genus. This analysis included estimation of divergence dates using a molecular clock and ancestral reconstruction of host associations and geography. We estimate that Bartonella began infecting mammals 62 million years ago near the Cretaceous-Paleogene boundary. Additionally, the radiation of particular Bartonella clades correlate strongly to the timing of diversification and biogeography of mammalian hosts. Bats were inferred to be the ancestral hosts of all mammal-associated Bartonella and appear to be responsible for the early geographic expansion of the genus. We conclude that bats have had a deep influence on the evolutionary radiation of Bartonella bacteria and their spread to other mammalian orders. These results support a 'bat seeding' hypothesis that could explain similar evolutionary patterns in other mammalian parasite taxa. Application of such phylogenetic tools as we have used to other taxa may reveal the general importance of bats in the ancient diversification of mammalian parasites.
Topics: Animals; Bartonella; Bartonella Infections; Chiroptera; Phylogeny; Stochastic Processes
PubMed: 33444855
DOI: 10.1016/j.meegid.2021.104719