-
Proceedings of the National Academy of... Jun 2022The bacterial genus comprises numerous emerging pathogens that cause a broad spectrum of disease manifestations in humans. The targets and mechanisms of the anti-...
The bacterial genus comprises numerous emerging pathogens that cause a broad spectrum of disease manifestations in humans. The targets and mechanisms of the anti- immune defense are ill-defined and bacterial immune evasion strategies remain elusive. We found that experimentally infected mice resolved infection by mounting antibody responses that neutralized the bacteria, preventing their attachment to erythrocytes and suppressing bacteremia independent of complement or Fc receptors. -neutralizing antibody responses were rapidly induced and depended on CD40 signaling but not on affinity maturation. We cloned neutralizing monoclonal antibodies (mAbs) and by mass spectrometry identified the bacterial autotransporter CFA (CAMP-like factor autotransporter) as a neutralizing antibody target. Vaccination against CFA suppressed bacteremia, validating CFA as a protective antigen. We mapped -neutralizing mAb binding to a domain in CFA that we found is hypervariable in both human and mouse pathogenic strains, indicating mutational antibody evasion at the subspecies level. These insights into immunity and immune evasion provide a conceptual framework for vaccine development, identifying important challenges in this endeavor.
Topics: Animals; Antibodies, Monoclonal; Antibodies, Neutralizing; Antigens, Bacterial; Bacteremia; Bacterial Vaccines; Bartonella; Bartonella Infections; Cloning, Molecular; Immune Evasion; Mice; Type V Secretion Systems; Vaccination
PubMed: 35714289
DOI: 10.1073/pnas.2202059119 -
Parasites & Vectors Aug 2018Bartonella spp. cause persistent bacterial infections in mammals. Although these bacteria are transmitted by blood-feeding arthropods, there is also evidence for...
Bartonella infections in three species of Microtus: prevalence and genetic diversity, vertical transmission and the effect of concurrent Babesia microti infection on its success.
BACKGROUND
Bartonella spp. cause persistent bacterial infections in mammals. Although these bacteria are transmitted by blood-feeding arthropods, there is also evidence for vertical transmission in their mammalian hosts. We aimed to determine: (i) the prevalence and diversity of Bartonella spp. in a Microtus spp. community; (ii) whether vertical transmission occurs from infected female voles to their offspring; (iii) the effect of concurrent Babesia microti infection on the success of vertical transmission of Bartonella; and (iv) the impact of congenital infection on pup survival.
RESULTS
We sampled 124 Microtus arvalis, 76 Microtus oeconomus and 17 Microtus agrestis. In total, 115 embryos were isolated from 21 pregnant females. In the following year 11 pregnant females were kept until they had given birth and weaned their pups (n = 62). Blood smears and PCR targeting the Bartonella-specific rpoB gene fragment (333bp) were used for the detection of Bartonella. Bartonella DNA was detected in 66.8% (145/217) of the wild-caught voles. Bartonella infection was detected in 81.8% (36/44) of pregnant female voles. Bartonella-positive individuals were identified among the embryos (47.1%; 40/85) and in 54.8% (34/62) of pups. Congenitally acquired Bartonella infections and co-infection with B. microti had no impact on the survival of pups over a 3-week period post partum. Among 113 Bartonella sequences, four species were detected: Bartonella taylorii, Bartonella grahamii, Bartonella doshiae and a Bartonella rochalimae-like genotype. Bartonella taylorii clade B was the dominant species in wild-caught voles (49%), pregnant females (47%), their embryos (85%), dams (75%) and pups (95%).
CONCLUSIONS
High prevalence of Bartonella spp. infection maintained in Microtus spp. community is followed by a high rate of vertical transmission of several rodent species of Bartonella in three species of naturally infected voles, M. arvalis, M. oeconomus and M. agrestis. Congenitally acquired Bartonella infection does not affect the survival of pups. Co-infection with B. microti does not affect the effectiveness of the vertical transmission of Bartonella in voles. Bartonella taylorii clade B was found to be the dominant species in wild-caught voles, including pregnant females and dams, and in their offspring, and was also found to be the most successful in vertical transmission.
Topics: Animals; Arvicolinae; Babesia microti; Babesiosis; Bartonella; Bartonella Infections; Coinfection; Embryo, Mammalian; Female; Genetic Variation; Genotype; Infectious Disease Transmission, Vertical; Prevalence; Rodent Diseases
PubMed: 30165879
DOI: 10.1186/s13071-018-3047-6 -
Zoonoses and Public Health Sep 2022Bartonella spp. and haemoplasmas are pathogens of veterinary and medical interest with ectoparasites mainly involved in their transmission. This study aimed at molecular...
Bartonella spp. and haemoplasmas are pathogens of veterinary and medical interest with ectoparasites mainly involved in their transmission. This study aimed at molecular detection of Bartonella spp. and haemoplasmas in cats (n = 93) and dogs (n = 96), and their related fleas (n = 189) from countries in East and Southeast Asia. Ctenocephalides felis was the dominant flea species infesting both cats (97.85%) and dogs (75%) followed by Ctenocephalides orientis in dogs (18.75%) and rarely in cats (5.2%). Bartonella spp. DNA was only detected in blood samples of flea-infested cats (21.51%) (p < .0001, OR = 27.70) with Bartonella henselae more frequently detected than Bartonella clarridgeiae in cat hosts (15.05%, 6.45%) and their associated fleas (17.24%, 13.79%). Out of three Bartonella-positive fleas from dogs, two Ct. orientis fleas carried Bartonella vinsonii subsp. berkhoffii and Bartonella clarridgeiae, while the 3rd flea (Ct. felis) carried Candidatus Bartonella merieuxii. Felines represented a risk factor for Bartonella spp. infections, where fleas collected from cats (32.25%) presented an increased likelihood for Bartonella spp. occurrence (p < .0001, OR = 14.76) than those from dogs (3.13%). Moreover, when analysing infectious status, higher Bartonella spp. DNA loads were detected in fleas from bacteraemic cats compared to those from non-bacteraemic ones (p < .05). The haemoplasma occurrence was 16.13% (15/93) and 4.17% (4/96) in cat and dog blood samples from different countries (i.e. Indonesia, Malaysia, the Philippines, Taiwan and Thailand), with cats more at risk of infection (p < .01, OR = 5.96) than dogs. Unlike Bartonella spp., there was no evidence for flea involvement in the hemoplasmas' transmission cycle, thus supporting the hypothesis of non-vectorial transmission for these pathogens. In conclusion, client-owned cats and dogs living in East and Southeast Asia countries are exposed to vector-borne pathogens with fleas from cats playing a key role in Bartonella spp. transmission, thus posing a high risk of infection for humans sharing the same environment.
Topics: Animals; Asia, Southeastern; Bacterial Load; Bartonella; Bartonella Infections; Cat Diseases; Cats; Ctenocephalides; Dog Diseases; Dogs; Flea Infestations; Humans; Mycoplasma; Siphonaptera
PubMed: 35545848
DOI: 10.1111/zph.12959 -
Applied and Environmental Microbiology Jan 2013Infections with Bartonella spp. have been recognized as emerging zoonotic diseases in humans. Large knowledge gaps exist, however, relating to reservoirs, vectors, and...
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.
Topics: Animals; Bacterial Proteins; Bartonella; Bartonella Infections; Blood; Coinfection; Diptera; Molecular Sequence Data; Norway; Ruminants; Sequence Analysis, DNA
PubMed: 23104416
DOI: 10.1128/AEM.02632-12 -
Journal of Veterinary Science May 2023Poor disease management and irregular vector control could predispose sheltered animals to disease such as feline infection, a vector-borne zoonotic disease primarily...
BACKGROUND
Poor disease management and irregular vector control could predispose sheltered animals to disease such as feline infection, a vector-borne zoonotic disease primarily caused by .
OBJECTIVES
This study investigated the status of infection in cats from eight (n = 8) shelters by molecular and serological approaches, profiling the CD4:CD8 ratio and the risk factors associated with infection in shelter cats.
METHODS
deoxyribonucleic acid (DNA) was detected through polymerase chain reaction (PCR) targeting 16S-23S rRNA internal transcribed spacer gene, followed by DNA sequencing. IgM and IgG antibody titre, CD4 and CD8 profiles were detected using indirect immunofluorescence assay and flow cytometric analysis, respectively.
RESULTS
was detected through PCR and sequencing in 1.0% (1/101) oral swab and 2.0% (1/50) cat fleas, while another 3/50 cat fleas carried Only 18/101 cats were seronegative against , whereas 30.7% (31/101) cats were positive for both IgM and IgG, 8% (18/101) cats had IgM, and 33.7% (34/101) cats had IgG antibody only. None of the eight shelters sampled had antibody-free cats. Although abnormal CD4:CD8 ratio was observed in 48/83 seropositive cats, flea infestation was the only significant risk factor observed in this study.
CONCLUSIONS
The present study provides the first comparison on the spp. antigen, antibody status and CD4:CD8 ratio among shelter cats. The high seropositivity among shelter cats presumably due to significant flea infestation triggers an alarm of whether the infection could go undetectable and its potential transmission to humans.
Topics: Humans; Animals; Cats; Malaysia; Bartonella Infections; Bartonella; Flea Infestations; Ctenocephalides; Immunoglobulin G; Cat Diseases
PubMed: 37271506
DOI: 10.4142/jvs.22277 -
Clinical & Developmental Immunology 2012Most infections by genus Bartonella in immunocompromised patients are caused by B. henselae and B. quintana. Unlike immunocompetent hosts who usually develop milder... (Review)
Review
Most infections by genus Bartonella in immunocompromised patients are caused by B. henselae and B. quintana. Unlike immunocompetent hosts who usually develop milder diseases such as cat scratch disease and trench fever, immunocompromised patients, including those living with HIV/AIDS and posttransplant patients, are more likely to develop different and severe life-threatening disease. This paper will discuss Bartonella's manifestations in immunosuppressed patients and will examine Bartonella's interaction with the immune system including its mechanisms of establishing infection and immune escape. Gaps in current understanding of the immunology of Bartonella infection in immunocompromised hosts will be highlighted.
Topics: Bartonella; Bartonella Infections; Bartonella henselae; Bartonella quintana; Cat-Scratch Disease; Cell Proliferation; HIV Infections; Humans; Immunocompromised Host; Trench Fever
PubMed: 22162717
DOI: 10.1155/2012/612809 -
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 -
PLoS Neglected Tropical Diseases Mar 2021Bartonella species are recognized globally as emerging zoonotic pathogens. Small mammals such as rodents and shrews are implicated as major natural reservoirs for these...
Bartonella species are recognized globally as emerging zoonotic pathogens. Small mammals such as rodents and shrews are implicated as major natural reservoirs for these microbial agents. Nevertheless, in several tropical countries, like India, the diversity of Bartonella in small mammals remain unexplored and limited information exists on the natural transmission cycles (reservoirs and vectors) of these bacteria. Using a multi-locus sequencing approach, we investigated the prevalence, haplotype diversity, and phylogenetic affinities of Bartonella in small mammals and their associated mites in a mixed-use landscape in the biodiverse Western Ghats in southern India. We sampled 141 individual small mammals belonging to eight species. Bartonella was detected in five of the eight species, including three previously unknown hosts. We observed high interspecies variability of Bartonella prevalence in the host community. However, the overall prevalence (52.5%) and haplotype diversity (0.9) was high for the individuals tested. Of the seven lineages of Bartonella identified in our samples, five lineages were phylogenetically related to putative zoonotic species-B. tribocorum, B. queenslandensis, and B. elizabethae. Haplotypes identified from mites were identical to those identified from their host species. This indicates that these Bartonella species may be zoonotic, but further work is necessary to confirm whether these are pathogenic and pose a threat to humans. Taken together, these results emphasize the presence of hitherto unexplored diversity of Bartonella in wild and synanthropic small mammals in mixed-use landscapes. The study also highlights the necessity to assess the risk of spillover to humans and other incidental hosts.
Topics: Animals; Bartonella; Bartonella Infections; DNA, Bacterial; Haplotypes; India; Mammals; Mite Infestations; Mites; Phylogeny; Polymerase Chain Reaction; Prevalence
PubMed: 33705398
DOI: 10.1371/journal.pntd.0009178 -
Clinical Microbiology Reviews Jan 2012Bartonella spp. are facultative intracellular pathogens that employ a unique stealth infection strategy comprising immune evasion and modulation, intimate interaction... (Review)
Review
Bartonella spp. are facultative intracellular pathogens that employ a unique stealth infection strategy comprising immune evasion and modulation, intimate interaction with nucleated cells, and intraerythrocytic persistence. Infections with Bartonella are ubiquitous among mammals, and many species can infect humans either as their natural host or incidentally as zoonotic pathogens. Upon inoculation into a naive host, the bartonellae first colonize a primary niche that is widely accepted to involve the manipulation of nucleated host cells, e.g., in the microvasculature. Consistently, in vitro research showed that Bartonella harbors an ample arsenal of virulence factors to modulate the response of such cells, gain entrance, and establish an intracellular niche. Subsequently, the bacteria are seeded into the bloodstream where they invade erythrocytes and give rise to a typically asymptomatic intraerythrocytic bacteremia. While this course of infection is characteristic for natural hosts, zoonotic infections or the infection of immunocompromised patients may alter the path of Bartonella and result in considerable morbidity. In this review we compile current knowledge on the molecular processes underlying both the infection strategy and pathogenesis of Bartonella and discuss their connection to the clinical presentation of human patients, which ranges from minor complaints to life-threatening disease.
Topics: Animals; Bartonella; Bartonella Infections; Disease Reservoirs; Disease Transmission, Infectious; Disease Vectors; Genotype; Humans; Mammals; Molecular Epidemiology; Molecular Typing; Virulence Factors
PubMed: 22232371
DOI: 10.1128/CMR.05009-11 -
PloS One 2015Our study highlights the surveillance of Bartonella species among rodents and their associated ectoparasites (ticks, fleas, lice, and mites) in several regions across...
Our study highlights the surveillance of Bartonella species among rodents and their associated ectoparasites (ticks, fleas, lice, and mites) in several regions across Thailand. A total of 619 rodents and 554 pooled ectoparasites (287 mite pools, 62 flea pools, 35 louse pools, and 170 tick pools) were collected from 8 provinces within 4 regions of Thailand. Bandicota indica (279), Rattus rattus (163), and R. exulans (96) were the most prevalent species of rats collected in this study. Real-time PCR assay targeting Bartonella-specific ssrA gene was used for screening and each positive sample was confirmed by PCR using nuoG gene. The prevalence of Bartonella DNA in rodent (around 17%) was recorded in all regions. The highest prevalence of Bartonella species was found in B. savilei and R. rattus with the rate of 35.7% (5/14) and 32.5% (53/163), respectively. High prevalence of Bartonella-positive rodent was also found in B. indica (15.1%, 42/279), and R. norvegicus (12.5%, 5/40). In contrast, the prevalence of Bartonella species in ectoparasites collected from the rats varied significantly according to types of ectoparasites. A high prevalence of Bartonella DNA was found in louse pools (Polyplax spp. and Hoplopleura spp., 57.1%) and flea pools (Xenopsylla cheopis, 25.8%), while a low prevalence was found in pools of mites (Leptotrombidium spp. and Ascoschoengastia spp., 1.7%) and ticks (Haemaphysalis spp., 3.5%). Prevalence of Bartonella DNA in ectoparasites collected from Bartonella-positive rodents (19.4%) was significantly higher comparing to ectoparasites from Bartonella-negative rodents (8.7%). The phylogenetic analysis of 41 gltA sequences of 16 Bartonella isolates from rodent blood and 25 Bartonella-positive ectoparasites revealed a wide range of diversity among Bartonella species with a majority of sequences (61.0%) belonging to Bartonella elizabethae complex (11 rodents, 1 mite pool, and 5 louse pools), while the remaining sequences were identical to B. phoceensis (17.1%, 1 mite pool, 5 louse pools, and 1 tick pool), B. coopersplainensis (19.5%, 5 rodents, 1 louse pool, and 2 tick pools), and one previously unidentified Bartonella species (2.4%, 1 louse pool).
Topics: Animals; Bartonella; Bartonella Infections; Insect Vectors; Mites; Phthiraptera; Phylogeny; Rats; Rodent Diseases; Rodentia; Siphonaptera; Thailand; Ticks
PubMed: 26484537
DOI: 10.1371/journal.pone.0140856