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Bartonella are vector-borne gram-negative facultative intracellular bacteria that can infect a wide spectrum of mammals, and are recognized as emerging human pathogens. This study aimed to investigate the prevalence and molecular characteristics of Bartonella infections in small mammals within the Qinghai Menyuan section of Qilian Mountain National Park, China. Small mammals were captured, and the liver, spleen and kidney were collected for Bartonella detection and identification using a combination of real-time PCR targeting the transfer-mRNA (ssrA) gene and followed by sequencing of the citrate synthase (gltA) gene. A total of 52 rodents were captured, and 36 rodents were positive for Bartonella, with a positivity rate of 69.23% (36/52). Bartonella was detected in Cricetulus longicaudatus, Microtus oeconomus, Mus musculus, and Ochotona cansus. The positivity rate was significantly different in the different habitats. Two Bartonella species were observed, including Bartonella grahamii and Bartonella heixiaziensis, and B. grahamii was the dominant epidemic strain in this area. Phylogenetic analysis showed that B. grahamii mainly clustered into two clusters, which were closely related to the Apodemus isolates from China and Japan and the local plateau pika isolates, respectively. In addition, genetic polymorphism analysis showed that B. grahamii had high genetic diversity, and its haplotype had certain regional differences and host specificity. Overall, high prevalence of Bartonella in small mammals in the Qinghai Menyuan section of Qilian Mountain National Park. B. grahamii is the dominant strain with high genetic diversity and potential pathogenicity to humans, and corresponding control measures should be considered. [ABSTRACT FROM AUTHOR]

Vector‐borne diseases pose a significant threat to human and animal health worldwide, with arthropods, including fleas and lice, acting as key vectors for transmitting various pathogens. In Uzbekistan, where millions of domestic dogs coexist with humans, the diversity of vector‐borne pathogens carried by ectoparasites remains largely unexplored. This study aimed to investigate the diversity and prevalence of lice and pathogens carried by fleas and lice collected from domestic dogs in Uzbekistan. Ectoparasites were collected from 77 dogs across five regions and subjected to morphological identification and molecular analysis. The 47 lice collected were identified as Trichodectes canis Fabricius, 1780 (Psocodea: Trichodectidae), Linognathus africanus Kellogg and Paine, 1911 (Psocodea: Linognathidae) and Bovicola bovis Linnaeus, 1758 (Phthiraptera: Trichodectidae), alongside with 197 fleas. Notably, L. africanus was detected for the first time on dogs worldwide. Molecular screening detected Rickettsia spp. in 27.9% fleas and 44.7% lice, Dipylidium caninum Linnaeus, 1758 (Cyclophyllidea: Dipylidiidae) in 1.5% of fleas and Bartonella spp. in 0.5% of fleas. Sequencing confirmed Rickettsia asembonensisMaina et al., 2016 (Rickettsiales: Rickettsiaceae), Rickettsia helvetica Beati et al., 1993 (Rickettsiales: Rickettsiaceae), Rickettsia monacensis Simser et al., 2019 (Rickettsiales: Rickettsiaceae), D. caninum and Bartonella clarridgeiae Lawson and Collins, 1996 (Hyphomicrobiales: Bartonellaceae). These findings highlight the potential role of dogs as reservoirs for vector‐borne pathogens and emphasises the need for further research to inform effective disease control strategies. [ABSTRACT FROM AUTHOR]

Vector-borne diseases account for nearly 20% of all globally recognised infectious diseases. Within the spectrum of flea-borne pathogens, Bartonella and Rickettsia bacteria are prominent, contributing to the emergence and resurgence of diseases on a global scale. This study investigates the presence of species of Bartonella and Rickettsia harboured by fleas collected from wild rodents in northwestern Argentina (NWA). A total of 28 fleas from three genera and seven species were assessed. DNA of Bartonella and Rickettsia spp. was found in 12 fleas (42.8%). Phylogenetic analysis of concatenated sequences of gltA and rpoB genes showed the presence of Bartonella quintana in eight fleas of two species, Craneopsylla minerva minerva and Polygenis acodontis. Phylogenetic analysis of concatenated sequences of gltA, ompA and ompB genes identified Rickettsia felis in ten fleas of five species, C. m. minerva, P. acodontis, Polygenis bohlsi bohlsi, Polygenis byturus and Tiamastus palpalis. These bacterial species mark the first report in all flea species studied. This study represents the first survey of flea-borne bacteria for NWA. The results provide information to address strategies for the control and prevention of bartonellosis and rickettsiosis that could have an impact on public health in one of the geographical areas of Argentina with the highest incidence of infections transmitted to humans by ectoparasites. [ABSTRACT FROM AUTHOR]

Background: Bartonella species are fastidious, intracellular bacteria responsible for an expanding array of human pathologies. Most are considered to be transmitted by direct inoculation with infected bodily fluids from a mammalian reservoir species or vector-transmitted through a variety of arthropod species and their excrement. However, there are mounting reports of infection in the absence of documented animal or vector contact. A variety of Bartonella species have been documented in conditions affecting both the peripheral and central nervous systems. More common conditions, including neuroretinitis, are often associated with Bartonella henselae. However, Bartonella quintana, the agent of trench fever, as well as emerging pathogens related to rodent reservoir species, B. grahamii and B. elizabethae, have also been documented. Encephalitis and encephalopathy, also most often associated with B. henselae, have been reported with B. quintana, B. washoensis (ground squirrels) and B. vinsonii subsp. vinsonii (voles) infections. Bartonella infections have also been associated with peripheral neuropathies, such as cranial nerve paresis and neuropathic pain, including infection with less commonly encountered species such as Bartonella koehlerae. Recently, molecular diagnostic testing revealed that DNA from Bartonella spp. was found to be more prevalent in blood of patients with neuropsychiatric disorders such as schizophrenia and psychoses compared to healthy controls. Methods: A systematic literature search was conducted on PubMed, Google Scholar and Web of Science. Search terms included Bartonella and specific neurological conditions and focused on peer-reviewed case reports published after 2012 pursuant to a prior review, with limited exceptions for conditions not previously covered. Published diagnostic testing, serology, molecular testing or pathology, were necessary for inclusion, except for one case which had clinical and epidemiological evidence consistent with diagnosis along with follow-up. Results: Neurobartonelloses included neuralgic amyotrophy, complex regional pain syndrome, chronic inflammatory demyelinating polyneuropathy, cranial nerve paralysis, Guillain-Barré syndrome, peripheral vasculitic polyneuropathy, acute transverse myelopathy, neuroretinitis, encephalitis/encephalopathy, cerebral vasculitis/aneurysm and neuropsychiatric conditions. Conclusions: The breadth of reported symptoms and clinical syndromes associated with an increasing number of Bartonella species continues to expand. Increased clinical awareness of this important zoonotic pathogen is necessary to advance One Health among the medical and veterinary communities. [ABSTRACT FROM AUTHOR]

Background: Rodent is a reservoir of various zoonotic pathogens. Wanzhou section of the Three Gorges reservoir region (TGRR) is a superior habitat for rodents, and the situation of rodent-borne zoonotic pathogens in this region has not been surveyed in recent years. Materials and Methods: Rodents were night trapped with mousecage or mousetrap in urban and surrounding towns' indoor or outdoor areas of the Wanzhou section of the TGRR, and nucleic acid was extracted from their lung or a mixture of liver, spleen, and kidney. Commercialized qPCR kits for pathogenic Leptospira spp., Rickettsia typhi, Anaplasma phagocytophilum, Bartonella spp., Orientia tsutsugamushi, and Francisella tularensis and qRT-PCR kits for hantavirus (HV), and severe fever with thrombocytopenia syndrome virus (SFTSV) were used for the detection of associated pathogens in collected rodents. Results: From 2021 to 2023, 604 rodents belonging to 10 species were collected. HV and pathogenic L. spp. were detected positive, with infection rates of 0.66% (4/604) and 1.32% (8/604), respectively. B. spp. were detected positive with an infection rate of 4.73% (19/402) in the rodents trapped in 2022 and 2023. Other five pathogens were all detected negative. Conclusion: This study showed that the Wanzhou section of the TGRR had HV, pathogenic L. spp., and B. spp. co-circulation in rodents. Hence, more attention should be paid to the prevention and control of associated rodent-borne diseases. [ABSTRACT FROM AUTHOR]

Bartonella spp. are opportunistic, vectorborne bacteria that can cause disease in both animals and humans. We investigated the molecular occurrence of Bartonella spp. in 634 phlebotomine sand fly specimens, belonging to 44 different sand fly species, sampled during 2017-2021 in north and northeastern Brazil. We detected Bartonella sp. DNA in 8.7% (55/634) of the specimens by using a quantitative real-time PCR targeting the 16S-23S internal transcribed spacer intergenic region. Phylogenetic analysis positioned the Lutzomyia longipalpis sand fly–associated Bartonella gltA gene sequence in the same subclade as Bartonella ancashensis sequences and revealed a Bartonella sp. sequence in a Dampfomyia beltrani sand fly from Mexico. We amplified a bat-associated Bartonella nuoG sequence from a specimen of Nyssomyia antunesi sand fly. Our findings document the presence of Bartonella DNA in sand flies from Brazil, suggesting possible involvement of these insects in the epidemiologic cycle of Bartonella species. [ABSTRACT FROM AUTHOR]

The purpose of the current study was to examine the occurrence and genetic characteristics of Bartonella henselae (B. henselae) and Bartonella clarridgeiae (B. clarridgeiae) in dogs from West Azerbaijan province, Iran. Blood samples were obtained from 400 dogs, and their gender, age, reproductive status, ownership status, and geographical origin were documented. Positive samples were identified using PCR and sequencing techniques, and the gene sequences of the ftsZ (for B.henselae) and gltA (for B.clarridgeiae) genes were examined using BioEdit software. The gene sequences acquired demonstrated a minimum similarity of 100.00% when compared to the reference sequences in the GenBank® database. Additionally, a phylogenetic tree was built using MEGA11. The findings of the study indicated that 8.5% (p<0.05; 95%, CI: 6.15%–11.64%) of the tested dogs were positive for B. henselae, and 3.25% (p<0.05; 95%, CI: 1.91%–5.48%) were positive for B. clarridgeiae. The results for both Bartonella species showed a significant difference (p=0.001) between neutered and nonneutered dogs, as well as a significant difference (p=0.001 and p=0.004) between stray and pet dogs. The study's findings highlight the significant role that dogs could potentially engage as the origins of Bartonella infection, as a zoonotic agent, in the region. [ABSTRACT FROM AUTHOR]

Parasites, including pathogens, can adapt to better exploit their hosts on many scales, ranging from within an infection of a single individual to series of infections spanning multiple host species. However, little is known about how the genomes of parasites in natural communities evolve when they face diverse hosts. We investigated how Bartonella bacteria that circulate in rodent communities in the dunes of the Negev Desert in Israel adapt to different species of rodent hosts. We propagated 15 Bartonella populations through infections of either a single host species (Gerbillus andersoni or Gerbillus pyramidum) or alternating between the two. After 20 rodent passages, strains with de novo mutations replaced the ancestor in most populations. Mutations in two mononucleotide simple sequence repeats (SSRs) that caused frameshifts in the same adhesin gene dominated the evolutionary dynamics. They appeared exclusively in populations that encountered G. andersoni and altered the dynamics of infections of this host. Similar SSRs in other genes are conserved and exhibit ON/OFF variation in Bartonella isolates from the Negev Desert dunes. Our results suggest that SSR-based contingency loci could be important not only for rapidly and reversibly generating antigenic variation to escape immune responses but that they may also mediate the evolution of host specificity. Author summary: In nature, pathogens encounter a diverse range of host individuals and species. Understanding how pathogens respond to this high host diversity is essential for predicting and controlling infectious diseases in humans and wildlife. Does host diversity slow down and limit pathogen evolution or accelerate a pathogen's ability to access and adapt to novel hosts? Despite its importance, there are few experimental studies of how pathogens evolve in response to host diversity. To address this gap, we conducted a year-long laboratory evolution experiment to study how Bartonella bacteria from the Negev Desert dunes in Israel adapted to different native rodent species under low and high host diversity scenarios. Pathogen evolution did not proceed more slowly or quickly with the differences in host diversity. Instead, the pathogen rapidly adapted to the more challenging host species through mutations in mononucleotide repeats within an adhesion gene that is a virulence factor. Analysis of the genomes of Bartonella isolates from wild gerbils suggests that hypermutable repeats in this gene and others may have been selected and preserved by evolution, potentially enabling rapid and reversible adaptation to changing host environments. Our findings highlight a possible role for these "contingency loci" in the evolution of host specificity. [ABSTRACT FROM AUTHOR]

Background and Objectives: Parinaud oculoglandular syndrome (POS) is unilateral granulomatous follicular conjunctivitis with ipsilateral afferent lymphadenopathy, primarily caused by cat-scratch disease, tularemia, and sporotrichosis. We report a case of POS in which Bartonella DNA was detected using polymerase chain reaction (PCR) in corneal and conjunctival specimens. Methods: A 29-year-old man, who started keeping a stray cat two months prior, became aware of right preauricular lymphadenopathy and right ocular conjunctival hyperemia one month prior. Subsequently, he developed a fever of approximately 37.9 °C, with a purulent ocular discharge appearing 1 week before being referred to our department for a detailed ophthalmological examination. The patient's right eye showed hyperemia and edema in the bulbar conjunctiva, along with palpebral conjunctival hyperemia, follicles, and white ulcers. Two weeks later, his serum IgM titer for Bartonella henselae was 1:20, and Bartonella DNA was detected by PCR in the corneal and conjunctival specimens. Based on these findings, the patient was diagnosed with POS caused by cat-scratch disease (CSD). Oral doxycycline, rifampicin, topical gatifloxacin, betamethasone phosphate, and erythromycin eye ointments were prescribed. Results: After 2 weeks of oral treatment and 2 months of eye drop treatment, the deterioration of the cornea and conjunctiva improved when the patient recovered good visual acuity. Conclusions: PCR assays of corneal and conjunctival specimens are useful for the diagnosis of CSD presenting with POS. These results suggested that Bartonella may be directly involved in the ocular surface pathogenesis of POS. [ABSTRACT FROM AUTHOR]

Lyme disease is the most commonly reported vector-borne disease in the United States. Bartonella constitute an additional zoonotic pathogen whose public health impact and diversity continue to emerge. Rapid, sensitive, and specific detection of these and other vector-borne pathogens remains challenging, especially for patients with persistent infections. This report describes an approach for DNA extraction and PCR testing for the detection of Bartonella spp. and Borreliella spp. from dry blood spot (DBS) specimens from human patients. The present study included extraction of DNA and PCR testing of DBS samples from 105 patients with poorly defined, chronic symptoms labeled as Lyme-Like Syndromic Illness (LLSI). Bartonella spp. DNA was detected in 20/105 (19%) and Borreliella spp. DNA was detected in 41/105 (39%) patients with LLSI. Neither group of organisms was detected in DBS samples from 42 healthy control subjects. Bartonella spp. 16S–23S rRNA internal transcribed spacer sequences were highly similar to ones previously identified in yellow flies, lone star ticks, a human patient from Florida, mosquitoes in Europe, or B. apihabitans and choladocola strains from honeybees. These human strains may represent new genetic strains or groups of human pathogenic species of Bartonella. The 41 Borreliella spp. flaB gene sequences obtained from human patients suggested the presence of four different species, including B. burgdorferi, B. americana, B. andersonii, and B. bissettiae/carolinensis-like strains. These results suggest that specific aspects of the DBS DNA extraction and PCR approach enabled the detection of Bartonella spp. and Borreliella spp. DNA from very small amounts of human whole blood from some patients, including specimens stored on filter paper for 17 years. [ABSTRACT FROM AUTHOR]

Abstract Bartonella are vector-borne gram-negative facultative intracellular bacteria that can infect a wide spectrum of mammals, and are recognized as emerging human pathogens. This study aimed to investigate the prevalence and molecular characteristics of Bartonella infections in small mammals within the Qinghai Menyuan section of Qilian Mountain National Park, China. Small mammals were captured, and the liver, spleen and kidney were collected for Bartonella detection and identification using a combination of real-time PCR targeting the transfer-mRNA (ssrA) gene and followed by sequencing of the citrate synthase (gltA) gene. A total of 52 rodents were captured, and 36 rodents were positive for Bartonella, with a positivity rate of 69.23% (36/52). Bartonella was detected in Cricetulus longicaudatus, Microtus oeconomus, Mus musculus, and Ochotona cansus. The positivity rate was significantly different in the different habitats. Two Bartonella species were observed, including Bartonella grahamii and Bartonella heixiaziensis, and B. grahamii was the dominant epidemic strain in this area. Phylogenetic analysis showed that B. grahamii mainly clustered into two clusters, which were closely related to the Apodemus isolates from China and Japan and the local plateau pika isolates, respectively. In addition, genetic polymorphism analysis showed that B. grahamii had high genetic diversity, and its haplotype had certain regional differences and host specificity. Overall, high prevalence of Bartonella in small mammals in the Qinghai Menyuan section of Qilian Mountain National Park. B. grahamii is the dominant strain with high genetic diversity and potential pathogenicity to humans, and corresponding control measures should be considered.

Abstract Background Bartonella species are fastidious, intracellular bacteria responsible for an expanding array of human pathologies. Most are considered to be transmitted by direct inoculation with infected bodily fluids from a mammalian reservoir species or vector-transmitted through a variety of arthropod species and their excrement. However, there are mounting reports of infection in the absence of documented animal or vector contact. A variety of Bartonella species have been documented in conditions affecting both the peripheral and central nervous systems. More common conditions, including neuroretinitis, are often associated with Bartonella henselae. However, Bartonella quintana, the agent of trench fever, as well as emerging pathogens related to rodent reservoir species, B. grahamii and B. elizabethae, have also been documented. Encephalitis and encephalopathy, also most often associated with B. henselae, have been reported with B. quintana, B. washoensis (ground squirrels) and B. vinsonii subsp. vinsonii (voles) infections. Bartonella infections have also been associated with peripheral neuropathies, such as cranial nerve paresis and neuropathic pain, including infection with less commonly encountered species such as Bartonella koehlerae. Recently, molecular diagnostic testing revealed that DNA from Bartonella spp. was found to be more prevalent in blood of patients with neuropsychiatric disorders such as schizophrenia and psychoses compared to healthy controls. Methods A systematic literature search was conducted on PubMed, Google Scholar and Web of Science. Search terms included Bartonella and specific neurological conditions and focused on peer-reviewed case reports published after 2012 pursuant to a prior review, with limited exceptions for conditions not previously covered. Published diagnostic testing, serology, molecular testing or pathology, were necessary for inclusion, except for one case which had clinical and epidemiological evidence consistent with diagnosis along with follow-up. Results Neurobartonelloses included neuralgic amyotrophy, complex regional pain syndrome, chronic inflammatory demyelinating polyneuropathy, cranial nerve paralysis, Guillain-Barré syndrome, peripheral vasculitic polyneuropathy, acute transverse myelopathy, neuroretinitis, encephalitis/encephalopathy, cerebral vasculitis/aneurysm and neuropsychiatric conditions. Conclusions The breadth of reported symptoms and clinical syndromes associated with an increasing number of Bartonella species continues to expand. Increased clinical awareness of this important zoonotic pathogen is necessary to advance One Health among the medical and veterinary communities. Graphical Abstract

Bartonella spp. are opportunistic, vectorborne bacteria that can cause disease in both animals and humans. We investigated the molecular occurrence of Bartonella spp. in 634 phlebotomine sand fly specimens, belonging to 44 different sand fly species, sampled during 2017–2021 in north and northeastern Brazil. We detected Bartonella sp. DNA in 8.7% (55/634) of the specimens by using a quantitative real-time PCR targeting the 16S-23S internal transcribed spacer intergenic region. Phylogenetic analysis positioned the Lutzomyia longipalpis sand fly–associated Bartonella gltA gene sequence in the same subclade as Bartonella ancashensis sequences and revealed a Bartonella sp. sequence in a Dampfomyia beltrani sand fly from Mexico. We amplified a bat-associated Bartonella nuoG sequence from a specimen of Nyssomyia antunesi sand fly. Our findings document the presence of Bartonella DNA in sand flies from Brazil, suggesting possible involvement of these insects in the epidemiologic cycle of Bartonella species.

Abstract Background In recent years, Babesia and Bartonella species co-infections in patients with chronic, nonspecific illnesses have continued to challenge and change the collective medical understanding of “individual pathogen” vector-borne infectious disease dynamics, pathogenesis and epidemiology. The objective of this case series is to provide additional molecular documentation of Babesia odocoilei infection in humans in the Americas and to emphasize the potential for co-infection with a Bartonella species. Methods The development of improved and more sensitive molecular diagnostic techniques, as confirmatory methods to assess active infection, has provided increasing clarity to the healthcare community. Results Using a combination of different molecular diagnostic approaches, infection with Babesia odocoilei was confirmed in seven people suffering chronic non-specific symptoms, of whom six were co-infected with one or more Bartonella species. Conclusions We conclude that infection with Babesia odocoilei is more frequent than previously documented and can occur in association with co-infection with Bartonella spp. Graphical Abstract

Abstract Objective Bartonella are emerging bacterial zoonotic pathogens. Utilization of clotted blood samples for surveillance of these bacteria in wildlife has begun to supersede the use of tissues; however, the efficacy of these samples has not been fully investigated. Our objective was to compare the efficacy of spleen and blood samples for DNA extraction and direct detection of Bartonella spp. via qPCR. In addition, we present a protocol for improved DNA extraction from clotted, pelleted (i.e., centrifuged) blood samples obtained from wild small mammals. Results DNA concentrations from kit-extracted blood clot samples were low and A260/A280 absorbance ratios indicated high impurity. Kit-based DNA extraction of spleen samples was efficient and produced ample DNA concentrations of good quality. We developed an in-house extraction method for the blood clots which resulted in apposite DNA quality when compared to spleen samples extracted via MagMAX DNA Ultra 2.0 kit. We detected Bartonella in 9/30 (30.0%) kit-extracted spleen DNA samples and 11/30 (36.7%) in-house-extracted blood clot samples using PCR. Our results suggest that kit-based methods may be less suitable for DNA extraction from blood clots, and that blood clot samples may be superior to tissues for Bartonella detection.

We analyzed body lice collected from persons experiencing homelessness in Winnipeg, Manitoba, Canada, during 2020–2021 to confirm vector species and ecotype and to identify louseborne pathogens. Of 556 lice analyzed from 7 persons, 17 louse pools (218 lice) from 1 person were positive for the louseborne bacterium Bartonella quintana.

Emerging zoonotic diseases are one of the main threats to human and animal health. Among the agents with the potential for zoonoses, those of bacterial origin have great relevance in Public Health. Rodents are considered one of the main reservoirs of pathogens that represent a risk to human health or animal species. We used massive 16S ribosomal RNA gene amplicon sequencing to survey bacteria present in the spleen of six species of rodents in Panama in order to identify bacterial taxa with zoonotic potential in the country. We found 3352 bacterial Amplicon Sequence Variants (ASVs, i.e., phylogenetic species) in the spleen of six rodent species surveyed (Liomys adspersus, Melanomys caliginosus, Mus musculus, Proechimys semispinosus, Rattus rattus, Zygodontomys brevicauda). This bacterial community was represented by 25 phyla, 55 classes, 140 orders, 268 families, and 508 genera. The three predominant phyla were Actinobacteria, Firmicutes, and Proteobacteria, and the five predominant classes were Actinobacteria, Alpha- and Gammaproteobacteria, Bacilli, and Clostridia. There were seven high-abundance genera: Acinetobacter, Bartonella, Cutibacterium, Enterococcus, Sarcina, Staphylococcus, and Wolbachia. Genera found with less abundance included Bradyrhizobium, Chryseobacterium, Clostridium, Corynebacterium, Lactobacillus, Pseudonocardia, Rhodococcus, and Sphingomonas. Some of these genera (high or low abundance) have clinical importance. The identification of bacterial taxa with zoonotic potential in rodent species performed here allows us to have surveillance mechanisms for these pathogens and to be able to recognize localities to be prioritized for prevention of transmission and outbreaks, thus being of value for public health in Panama.

Abstract Background Fleas, considered to be the main transmission vectors of Bartonella, are highly prevalent and show great diversity. To date, no investigations have focused on Bartonella vectors in Southeast China. The aim of this study was to investigate the epidemiological and molecular characteristics of Bartonella in fleas in Southeast China. Methods From 2016 to 2022, flea samples (n = 1119) were collected from 863 rodent individuals in seven inland and coastal cities in Southeast China. Flea species, region, gender, host species and habitat were recorded. The DNA samples from each individual flea were screened by real-time PCR for the Bartonella ssrA gene. All positive samples were confirmed by PCR based on the presence of the gltA gene and sequenced. The factors associated with Bartonella infection were analyzed by the Chi-square test and Fisher's exact test. ANOVA and the t-test were used to compare Bartonella DNA load. Results Bartonella DNA was detected in 26.2% (293/1119) of the flea samples, including in 27.1% (284/1047) of Xenopsylla cheopis samples, 13.2% (5/38) of Monopsyllus anisus samples, 8.3% (2/24) of Leptopsylla segnis samples and 20.0% (2/10) of other fleas (Nosopsyllus nicanus, Ctenocephalides felis, Stivalius klossi bispiniformis and Neopsylla dispar fukienensis). There was a significant difference in the prevalence of Bartonella among flea species, sex, hosts, regions and habitats. Five species of Bartonella fleas were identified based on sequencing and phylogenetic analyses targeting the gltA gene: B. tribocorum, B. queenslandensis, B. elizabethae, B. rochalimae and B. coopersplainsensis. Conclusions There is a high prevalence and diversity of Bartonella infection in the seven species of fleas collected in Southeast China. The detection of zoonotic Bartonella species in this study, including B. tribocorum, B. elizabethae and B. rochalimae, raises public health concerns. Graphical Abstract

Few studies have examined the genetic population structure of vector-borne microparasites in wildlife, making it unclear how much these systems can reveal about the movement of their associated hosts. This study examined the complex host–vector–microbe interactions in a system of bats, wingless ectoparasitic bat flies (Nycteribiidae), vector-borne microparasitic bacteria (Bartonella) and bacterial endosymbionts of flies (Enterobacterales) across an island chain in the Gulf of Guinea, West Africa. Limited population structure was found in bat flies and Enterobacterales symbionts compared to that of their hosts. Significant isolation by distance was observed in the dissimilarity of Bartonella communities detected in flies from sampled populations of Eidolon helvum bats. These patterns indicate that, while genetic dispersal of bats between islands is limited, some non-reproductive movements may lead to the dispersal of ectoparasites and associated microbes. This study deepens our knowledge of the phylogeography of African fruit bats, their ectoparasites and associated bacteria. The results presented could inform models of pathogen transmission in these bat populations and increase our theoretical understanding of community ecology in host–microbe systems.

Mild Cognitive Impairment (MCI) is a neurological disorder at the transition between normal cognitive decline and dementia. Despite the potential role of neuroinflammation in the pathogenesis of MCI, infectious triggers remain mostly unknown. Infection with Bartonella spp., a zoonotic bacterium, has recently been associated with diffuse neurological and psychiatric symptoms. Given the preferential endothelial localization of Bartonella spp. and the role of vascular changes in neurocognitive decline, we hypothesized that there is an association between Bartonella spp. infection and pathologically accelerated decline in cognitive function in aging. To test this hypothesis, we collected serological and molecular markers of past and present Bartonella spp. infection in a sample of older people with and without MCI. Samples were processed in a blinded way to exclude laboratory biases. Contrary to our hypothesis, people with MCI were not more likely than people without MCI to have an active Bartonella spp. infection as measured by droplet digital PCR (p = 0.735) and quantitative PCR (p = 1). In addition, there was no significant difference in positive serological results between cases and controls (p = 0.461). Overall, higher-than-expected active Bartonella spp. infection (37% by ddPCR) and seroreactivity (71% by indirect fluorescent antibody assay) were found in people without MCI. Conclusions require caution, as our study was limited by the small number of cases with MCI. Overall, our results identified a higher than previously recognized rate of exposure and infection with Bartonella spp. in this older study population but does not support a specific role for such infection in MCI. [ABSTRACT FROM AUTHOR]

Background: Bartonella spp. infect a variety of vertebrates throughout the world, with generally high prevalence. Several Bartonella spp. are known to cause diverse clinical manifestations in humans and have been recognized as emerging pathogens. These bacteria are mainly transmitted by blood-sucking arthropods, such as fleas and lice. The role of ticks in the transmission of Bartonella spp. is unclear. Methods: A recently developed quadruplex polymerase chain reaction (PCR) amplicon next-generation sequencing approach that targets Bartonella-specific fragments on gltA, ssrA, rpoB, and groEL was applied to test host-seeking Ixodes scapularis ticks (n = 1641; consisting of 886 nymphs and 755 adults) collected in 23 states of the eastern half of the United States and Ixodes pacificus ticks (n = 966; all nymphs) collected in California in the western United States for the presence of Bartonella DNA. These species were selected because they are common human biters and serve as vectors of pathogens causing the greatest number of vector-borne diseases in the United States. Results: No Bartonella DNA was detected in any of the ticks tested by any target. Conclusions: Owing to the lack of Bartonella detection in a large number of host-seeking Ixodes spp. ticks tested across a broad geographical region, our results strongly suggest that I. scapularis and I. pacificus are unlikely to contribute more than minimally, if at all, to the transmission of Bartonella spp. [ABSTRACT FROM AUTHOR]

Background: Cats are hosts and reservoirs for many haemopathogens such as piroplasms, Rickettsia, hemotropic Mycoplasma, Bartonella, Ehrlichia, and Anaplasma, which are transmitted by various vector arthropods and some of which have a zoonotic concern. Although it is noteworthy that the rate of ownership of companion animals has increased in Türkiye in recent years and that cats account for a large proportion of these animals, there is limited research on the vector-borne infectious agents carried by them. The present study aimed to provide a comprehensive molecular epidemiological data and molecular characterization of feline vector-borne haemopathogens (FVBHs), including piroplasms, anaplasmataceae, rickettsias, haemoplasmas, and Bartonella species in Türkiye. In total, 250 feline blood samples were collected from client-owned cats (n = 203) and shelter cats (n = 47) brought to the Small Animal Hospital of Selcuk University, Veterinary Faculty. Results: Overall, 40 (16%) cats were found to be infected with at least one of the investigated haemopathogens and piroplasm, Mycoplasma spp. and Bartonella spp. prevalence was 1.6%, 11.2%, and 4.8%, respectively. No Anaplasma/Ehrlichia spp. and Rickettsia spp. DNA was detected in the investigated feline samples. Sequence analysis revealed that all four piroplasms belonged to Babesia ovis with a 97.93–99.82% nucleotide sequence identity to 18S rRNA gene sequences from Spain and Türkiye, while some sequenced hemoplasmas were Mycoplasma haemofelis (Mhf), Candidatus Mycoplasma haemominutum (CMhm) and Mycoplasma wenyonii, and Bartonella spp. were Bartonella henselae and Bartonella koehlerae species. Co-infections with Mycoplasma spp. and Bartonella spp. were also detected in 4 cats (1.6%) in this study, where single infections were predominant. Conclusion: This study provides valuable information on zoonotically important feline vector-borne hemopathogens in Türkiye, some of which have received attention under the One Health perspective, and is the first molecular epidemiological study to demonstrate the presence of Babesia ovis, the causative agent of ovine babesiosis, and Mycoplasma wenyonii DNA, the causative agent of bovine haemotropic mycoplasmosis, in cats. Further studies on the roles of such pathogens detected in unspecific hosts and the host specificity of the vectors that transmit them will contribute to the elucidation of this situation. [ABSTRACT FROM AUTHOR]

This study aimed to determine the sequence type (ST) of Bartonella henselae infecting small Indian mongooses from Saint Kitts via multi-locus sequence typing (MLST). This investigation used stored EDTA blood (n = 22) samples from mongooses previously identified as positive for B. henselae. Chocolate agar plates were enriched with Bartonella alpha-Proteobacteria growth medium (BAPGM) to culture and isolate Bartonella from the blood samples. To perform MLST, DNA was extracted and purified from isolates followed by amplification by conventional PCR (300–500 bp) for eight genes (16S rDNA, batR, gltA, groEL, ftsZ, nlpD, ribC, and rpoB). Bartonella henselae STs were deposited in the PubMLST repository. Out of 22 B. henselae-positive blood samples, isolates were obtained from 12 mongooses (54.5%; 12/22). Each mongoose was infected with one ST. The studied mongoose population was infected with sequence types ST2, ST3, ST8, and a novel ST represented by ST38. Bartonella henselae ST2, ST3 and ST8 infecting mongooses are known to circulate in humans and cats, with ST2 and ST8 associated with Cat Scratch Disease (bartonellosis) in humans. The results presented herein denote the circulation of B. henselae STs with zoonotic potential in mongooses with risk of B. henselae transmission to humans. [ABSTRACT FROM AUTHOR]

Bartonella quintana is a louse-borne intracellular bacterium that remains a neglected cause of bacteremia, bacillary angiomatosis, and infective endocarditis among individuals experiencing poverty. In October 2023, Health Canada notified Canadian organ transplantation programs of an outbreak of donor-derived B quintana infection. From March to August 2023, 5 cases of donor-derived B quintana disease were acquired in Alberta, Canada, from 3 deceased donors who had experienced homelessness. Similar cases recently occurred in the United States. In this article, we discuss strategies to screen organ donors and monitor transplant recipients for B quintana infection using epidemiologic risk factors, physical examination signs, and laboratory diagnostic tests. We review the limitations of existing diagnostic tests for B quintana and describe how these problems may be magnified in the organ transplantation context. [ABSTRACT FROM AUTHOR]

Bartonella spp. are intracellular bacteria associated with several re-emerging human diseases. Small mammals play a significant role in the maintenance and spread of Bartonella spp. Despite the high small mammal biodiversity in South Africa, there is limited epidemiological information regarding Bartonella spp. in these mammals. The main aim of this study was to determine the prevalence and genetic diversity of Bartonella spp. from wild small mammals from 15 localities in 8 provinces of South Africa. Small mammals (n = 183) were trapped in the Eastern Cape, Free State, Gauteng, Limpopo, Mpumalanga, Northern Cape, North West, and Western Cape provinces of South Africa between 2010 and 2018. Heart, kidney, liver, lung, and spleen were harvested for Bartonella DNA screening, and prevalence was determined based on the PCR amplification of partial fragments of the 16S-23S rRNA intergenic spacer (ITS) region, gltA, and rpoB genes. Bartonella DNA was detected in Aethomys chrysophilus, Aethomys ineptus, Gerbillurus spp., Lemniscomys rosalia, Mastomys coucha, Micaelamys namaquensis, Rhabdomys pumilio, and Thallomys paedulcus. An overall prevalence of 16.9% (31/183, 95% CI: 12.2%-23%) was observed. Bartonella elizabethae, Bartonella grahamii, and Bartonella tribocorum were the zoonotic species identified, while the remaining sequences were aligned to uncultured Bartonella spp. with unknown zoonotic potential. Phylogenetic analyses confirmed five distinct Bartonella lineages (I-V), with lineage IV displaying strong M. coucha host specificity. Our results confirm that South African wild small mammals are natural reservoirs of a diverse assemblage of Bartonella spp., including some zoonotic species with high genetic diversity, although prevalence was relatively low. [ABSTRACT FROM AUTHOR]

Background: Bartonellosis, caused by bacteria of the genus Bartonella, is a zoonotic disease with several mammalian reservoir hosts. In Somalia, a country heavily reliant on livestock, zoonotic diseases pose significant public health and economic challenges. To the best of our knowledge, no study has been performed aiming to verify the occurrence of Bartonella spp. in Somalia. This study investigated the occurrence and molecular characterization of Bartonella in dromedary (Camelus dromedarius, Linnaeus, 1758), cattle, sheep, and goats from Somalia. Materials and Methods: 530 blood samples were collected from various animals (155 dromedary, 199 goat, 131 cattle, and 45 sheep) in Benadir and Lower Shabelle regions. DNA was extracted for molecular analysis, and a qPCR assay targeting the NADH dehydrogenase gamma subunit (nuoG) gene was used for Bartonella screening. Positive samples were also subjected to PCR assays targeting seven molecular markers including: nuoG, citrate synthase gene (gltA), RNA polymerase beta‐subunit gene (rpoB), riboflavin synthase gene (ribC), 60 kDa heat‐shock protein gene (groEL), cell division protein gene (ftsZ), and pap31 and qPCR targeting the 16‐23S rRNA internal transcribed spacer (ITS) followed by Sanger sequencing, BLASTn and phylogenetic analysis. Results: Out of 530 tested animals, 5.1% were positive for Bartonella spp. by the nuoG qPCR assay. Goats showed the highest Bartonella occurrence (17/199, 8.5%), followed by sheep (6/44, 6.8%), cattle (4/131, 3.1%), and dromedary (1/155, 1.9%). Goats, sheep, and cattle had higher odds of infection compared to dromedary. Among nuoG qPCR‐positive samples, 11.1%, 14.8%, 11.1%, and 25.9% were positive in PCR assays based on nuoG, gltA, and pap31 genes, and in the qPCR based on the ITS region, respectively. On the other hand, nuoG qPCR‐positive samples were negative in the PCR assays targeting the ribC, rpoB, ftsZ, and groEL genes. While Bartonella bovis sequences were detected in cattle (nuoG and ITS) and goats (gltA), Bartonella henselae ITS sequences were detected in dromedary, goat, and sheep. Phylogenetic analysis placed gltA Bartonella sequence from a goat in the same clade of B. bovis. Conclusion: The present study showed, for the first time, molecular evidence of Bartonella spp. in dromedary and ruminants from Somalia and B. henselae in sheep and goats globally. These findings contribute valuable insights into Bartonella spp. occurrence in Somali livestock, highlighting the need for comprehensive surveillance and control measures under the One Health approach. [ABSTRACT FROM AUTHOR]

Bacterial zoonoses are established causes of severe febrile illness in East Africa. Within a fever etiology study, we applied a high-throughput 16S rRNA metagenomic assay validated for detecting bacterial zoonotic pathogens. We enrolled febrile patients admitted to 2 referral hospitals in Moshi, Tanzania, during September 2007-April 2009. Among 788 participants, median age was 20 (interquartile range 2-38) years. We performed PCR amplification of V1-V2 variable region 16S rRNA on cell pellet DNA, then metagenomic deep-sequencing and pathogenic taxonomic identification. We detected bacterial zoonotic pathogens in 10 (1.3%) samples: 3 with Rickettsia typhi, 1 R. conorii, 2 Bartonella quintana, 2 pathogenic Leptospira spp., and 1 Coxiella burnetii. One other sample had reads matching a Neoerhlichia spp. previously identified in a patient from South Africa. Our findings indicate that targeted 16S metagenomics can identify bacterial zoonotic pathogens causing severe febrile illness in humans, including potential novel agents. [ABSTRACT FROM AUTHOR]

Objectives: Bartonella spp., renowned for cat-scratch disease, has limited reports of dissemination. Tissue and blood cultures have limitations in detecting this fastidious pathogen. Molecular testing (polymerase chain reaction, PCR) and cell-free DNA have provided an avenue for diagnoses. This retrospective observational multicenter study describes the incidence of disseminated Bartonella spp. and treatment-related outcomes. Methods: Inclusion criteria were diagnosis of bartonellosis via diagnosis code, serology testing of blood, polymerase chain reaction (PCR) of blood, 16/18S tests of blood or tissue, cultures of blood or tissue, or cell-free DNA of blood or tissue from January 1, 2014, through September 1, 2021. Exclusions were patients who did not receive treatment, insufficient data on treatment course, absence of dissemination, or retinitis as dissemination. Results: Patients were primarily male (n = 25, 61.0%), white (n = 28, 68.3%), with mean age of 50 years (SD 14.4), and mean Charlson comorbidity index of 3.5 (SD 2.1). Diagnosis was primarily by serology (n = 34, 82.9%), with Bartonella henselae (n = 40, 97.6%) as the causative pathogen. Treatment was principally doxycycline with rifampin (n = 17, 41.5%). Treatment failure occurred in 16 (39.0%) patients, due to escalation of therapy during treatment (n = 5, 31.3%) or discontinuation of therapy due to an adverse event or tolerability (n = 5, 31.3%). Conclusions: In conclusion, this is the largest United States-based cohort of disseminated Bartonella spp. infections to date with a reported 39% treatment failure. This adds to literature supporting obtaining multiple diagnostic tests when Bartonella is suspected and describes treatment options. [ABSTRACT FROM AUTHOR]

Background: In recent years, Babesia and Bartonella species co-infections in patients with chronic, nonspecific illnesses have continued to challenge and change the collective medical understanding of "individual pathogen" vector-borne infectious disease dynamics, pathogenesis and epidemiology. The objective of this case series is to provide additional molecular documentation of Babesia odocoilei infection in humans in the Americas and to emphasize the potential for co-infection with a Bartonella species. Methods: The development of improved and more sensitive molecular diagnostic techniques, as confirmatory methods to assess active infection, has provided increasing clarity to the healthcare community. Results: Using a combination of different molecular diagnostic approaches, infection with Babesia odocoilei was confirmed in seven people suffering chronic non-specific symptoms, of whom six were co-infected with one or more Bartonella species. Conclusions: We conclude that infection with Babesia odocoilei is more frequent than previously documented and can occur in association with co-infection with Bartonella spp. [ABSTRACT FROM AUTHOR]

Objective: Bartonella are emerging bacterial zoonotic pathogens. Utilization of clotted blood samples for surveillance of these bacteria in wildlife has begun to supersede the use of tissues; however, the efficacy of these samples has not been fully investigated. Our objective was to compare the efficacy of spleen and blood samples for DNA extraction and direct detection of Bartonella spp. via qPCR. In addition, we present a protocol for improved DNA extraction from clotted, pelleted (i.e., centrifuged) blood samples obtained from wild small mammals. Results: DNA concentrations from kit-extracted blood clot samples were low and A260/A280 absorbance ratios indicated high impurity. Kit-based DNA extraction of spleen samples was efficient and produced ample DNA concentrations of good quality. We developed an in-house extraction method for the blood clots which resulted in apposite DNA quality when compared to spleen samples extracted via MagMAX DNA Ultra 2.0 kit. We detected Bartonella in 9/30 (30.0%) kit-extracted spleen DNA samples and 11/30 (36.7%) in-house-extracted blood clot samples using PCR. Our results suggest that kit-based methods may be less suitable for DNA extraction from blood clots, and that blood clot samples may be superior to tissues for Bartonella detection. [ABSTRACT FROM AUTHOR]

Bats, with their robust immune system, frequently serve as hosts for viruses and bacteria. Bartonella spp. are transmitted by blood-sucking arthropods and are widely distributed among various mammalian species globally. The present study focused on the molecular detection of Bartonella spp. From ectoparasites infesting widely distributed Rhinolophus affinis in Southwest China. Briefly, the bats were captured from four districts, namely Xundian, Jinning, Lufeng, and Mouding and ectoparasites collected from these bats. The ectoparasites were identified based on morphological characteristics, and the biodiversity of ectoparasites infesting bats in the study area was elucidated through spatial distribution and analysis of dominant species. Further, DNA was extracted from ectoparasites and three targeted genes (ftsZ, gltA, and rpoB) of Bartonella were amplified using conventional PCR. Sixty R. affinis bats were captured with an impressive ectoparasites infestation rate of 90.00%. A total of 10 species were identified comprising 1,412 ectoparasites, with the dominant species being Eyndhovenia euryalis (Y = 0.099, m*/m = 2.439), Macronyssys tieni (Y = 0.563, m*/m = 2.040), Macronyssys dechangensis (Y = 0.024, m*/m = 1.815), Ixodes vespertilionis (Y = 0.026, m*/m = 2.146), and Stylidia fraterna (Y = 0.052, m*/m = 1.436) (one species of bat fly), all of which exhibited aggregated distribution on the host's body surface. Notably, the detection of 172 ectoparasites in the bats revealed that all positive cases of Bartonella were found in S. fraterna. This high prevalence may be attributed to the unique reproductive strategy of bat flies, which facilitates vertical transmission of Bartonella. Therefore, bat flies may act as potential vectors for Bartonella transmission. This study deepens understanding of the ectoparasite diversity of R. affinis and broadens our knowledge of the geographical distribution of this pathogen. [ABSTRACT FROM AUTHOR]

This comprehensive review provides updates on the epidemiology, clinical presentations, and diagnostic methods for the most common Bartonella species causing human disease, including B. henselae, B. quintana, and B. bacilliformis. We highlight the distinctive transmission dynamics and clinical manifestations associated with each species, such as cat-scratch disease, trench fever, and Carrion's disease. The review also evaluates the advantages and limitations of serological and molecular diagnostic techniques, emphasizing the importance of integrating clinical evaluation with laboratory testing for accurate diagnosis and effective management of Bartonella infections. [ABSTRACT FROM AUTHOR]

We analyzed body lice collected from persons experiencing homelessness in Winnipeg, Manitoba, Canada, during 2020--2021 to confirm vector species and ecotype and to identify louseborne pathogens. Of 556 lice analyzed from 7 persons, 17 louse pools (218 lice) from 1 person were positive for the louseborne bacterium Bartonella quintana. [ABSTRACT FROM AUTHOR]

Battery poultry houses are subject to infestations by pests, such as the ectoparasitic mites Dermanyssus gallinae (De Geer, 1778) and Ornithonyssus bursa (Berlese, 1888) which are hematophagous and can cause skin lesions, stress, and even death of hens, leading to significant economic losses. Recent European studies have shown that these mites can also work as vectors of pathogenic microorganisms. Therefore, due to the absence of records on the association between D. gallinae and O. bursa and pathogenic microorganisms in Brazil, the present study aimed to identify pathogenic bacteria through a metagenomics analysis associated with mites collected from a poultry house located in a rural area of the state of Rio Grande do Sul and direct from a skin' person that lives in a farm in the interior of the state of São Paulo (Brazil). For the material collected in Rio Grande do Sul, a higher predominance of endosymbiotic bacteria, and different species of the pathogenic bacteria species Bartonella was observed. On the other hand, some enterobacteria were identified from O. bursa samples, but the amount was not high enough to identify the species. Additionally, the endosymbiotic Wolbachia spp. was identified in both O. bursa samples (pooled and individuals). Besides the detection of Wolbachia, in the individual O. bursa microbiome, we detected Spiroplasma spp. and 'Candidatus Cardinium'. This is the first time that a microbiome study has been made for the species D. gallinae and O. bursa in Brazil, as well as the first time that Wolbachia, Spiroplasma and 'Candidatus Cardinium' was detected in O. bursa samples. [ABSTRACT FROM AUTHOR]

Simple Summary: Birds are known to be carriers of ticks, both Argasidae and Ixodidae, which often harbor bacterial pathogens. Climatic changes observed in the last years have influenced tick distributions in several geographic areas and the migratory behaviors of many avian species; consequently, wild birds can be responsible for the introduction of ticks and relative pathogens, most of which are zoonotic, in new environments. Some studies have been carried out to detect tick-borne bacteria in ticks removed from birds worldwide, but surveys on the presence of these pathogens directly in avifauna are very scanty. This study evaluated the occurrence of tick-borne bacteria, such as Anaplasma phagocytophilum, Bartonella spp., Borrelia burgdorferi sensu lato, Chlamydia psittaci, Coxiella burnetii, Ehrlichia canis, Francisella tularensis, and Rickettsia spp., in avian spleen samples, and the obtained results suggested that wild avifauna may be involved in the epidemiology of some of the investigated pathogens. Birds are known to be carriers of ticks infected by tick-borne pathogens, including bacteria. However, not many studies have been carried out on avian tissues to detect these agents. The aim of the present survey was to investigate, using PCR, the presence of Anaplasma phagocytophilum, Bartonella spp., Borrelia burgdorferi sensu lato, Chlamydia psittaci, Coxiella burnetii, Ehrlichia canis, Francisella tularensis, and Rickettsia spp. in the spleens collected from 300 wild birds of different orders and species from Central Italy. A total of 53 (17.67%) samples were PCR positive for at least one investigated pathogen. One (0.33%) bird was positive for Bartonella spp., five (1.67%) birds were positive for C. burnetii, eleven (3.67%) for B. burgdorferi s.l., and thirty-six (12%) for C. psittaci. No coinfection was detected. All samples were negative for A. phagocytophilum, E. canis, F. tularensis, and Rickettsia spp. The findings showed that wild birds may harbor different zoonotic tick-borne bacteria; therefore, they can contribute to the diffusion of these agents. [ABSTRACT FROM AUTHOR]

Introduction: The potential role of pathogens, particularly vector-transmitted infectious agents, as a cause of psychosis has not been intensively investigated. We have reported a potential link between Bartonella spp. bacteremia and neuropsychiatric symptoms, including pediatric acute onset neuropsychiatric syndrome and schizophrenia. The purpose of this study was to further assess whether Bartonella spp. exposure or infection are associated with psychosis. Methods: In a blinded manner, we assessed the presence of anti-Bartonella antibodies by indirect immunofluorescence assays (IFA), and infection by amplification of bacterial DNA from blood by quantitative polymerase chain reaction (qPCR), digital PCR (dPCR), and droplet digital PCR (ddPCR) in 116 participants. Participants were categorized into one of five groups: 1) controls unaffected by psychosis (n = 29); 2) prodromal participants (n = 16); 3) children or adolescents with psychosis (n = 7); 4) adults with psychosis (n = 44); and 5) relatives of a participant with psychosis (n = 20). Results: There was no significant difference in Bartonella spp. IFA seroreactivity between adults with psychosis and adult controls unaffected by psychosis. There was a higher proportion of adults with psychosis who had Bartonella spp. DNA in the bloodstream (43.2%) compared to adult controls unaffected by psychosis (14.3%, p = 0.021). The Bartonella species was determined for 18 of the 31 bacteremic participants, including infection or co-infection with Bartonella henselae (11/18), Bartonella vinsonii subsp. berkhoffii (6/18), Bartonella quintana (2/18), Bartonella alsatica (1/18), and Bartonella rochalimae (1/18). Discussion: In conjunction with other recent research, the results of this study provide justification for a large national or international multi-center study to determine if Bartonella spp. bacteremia is more prevalent in adults with psychosis compared to adults unaffected by psychosis. Expanding the investigation to include a range of vector-borne and other microbial infections with potential CNS effects would enhance knowledge on the relationship between psychosis and infection. [ABSTRACT FROM AUTHOR]

Background: Fleas, considered to be the main transmission vectors of Bartonella, are highly prevalent and show great diversity. To date, no investigations have focused on Bartonella vectors in Southeast China. The aim of this study was to investigate the epidemiological and molecular characteristics of Bartonella in fleas in Southeast China. Methods: From 2016 to 2022, flea samples (n = 1119) were collected from 863 rodent individuals in seven inland and coastal cities in Southeast China. Flea species, region, gender, host species and habitat were recorded. The DNA samples from each individual flea were screened by real-time PCR for the Bartonella ssrA gene. All positive samples were confirmed by PCR based on the presence of the gltA gene and sequenced. The factors associated with Bartonella infection were analyzed by the Chi-square test and Fisher's exact test. ANOVA and the t-test were used to compare Bartonella DNA load. Results: Bartonella DNA was detected in 26.2% (293/1119) of the flea samples, including in 27.1% (284/1047) of Xenopsylla cheopis samples, 13.2% (5/38) of Monopsyllus anisus samples, 8.3% (2/24) of Leptopsylla segnis samples and 20.0% (2/10) of other fleas (Nosopsyllus nicanus, Ctenocephalides felis, Stivalius klossi bispiniformis and Neopsylla dispar fukienensis). There was a significant difference in the prevalence of Bartonella among flea species, sex, hosts, regions and habitats. Five species of Bartonella fleas were identified based on sequencing and phylogenetic analyses targeting the gltA gene: B. tribocorum, B. queenslandensis, B. elizabethae, B. rochalimae and B. coopersplainsensis. Conclusions: There is a high prevalence and diversity of Bartonella infection in the seven species of fleas collected in Southeast China. The detection of zoonotic Bartonella species in this study, including B. tribocorum, B. elizabethae and B. rochalimae, raises public health concerns. [ABSTRACT FROM AUTHOR]

Aims: Rat‐associated zoonotic pathogen transmission at the human–wildlife interface is a public health concern in urban environments where Norway rats (Rattus norvegicus) thrive on abundant anthropogenic resources and live in close contact with humans and other animal species. To identify potential factors influencing zoonotic pathogen occurrence in rats, we investigated associations between environmental and sociodemographic factors and Leptospira interrogans and Bartonella spp. infections in rats from Windsor, Ontario, Canada, while controlling for the potential confounding effects of animal characteristics (i.e., sexual maturity and body condition). Methods and Results: Between November 2018 and June 2021, 252 rats were submitted by collaborating pest control professionals. Kidney and spleen samples were collected for L. interrogans and Bartonella spp. PCR and sequencing, respectively. Of the rats tested by PCR, 12.7% (32/252) were positive for L. interrogans and 16.3% (37/227) were positive for Bartonella species. Associations between infection status and environmental and sociodemographic variables of interest were assessed via mixed multivariable logistic regression models with a random intercept for social group and fixed effects to control for sexual maturity and body condition in each model. The odds of L. interrogans infection were significantly higher in rats from areas with high building density (odds ratio [OR]: 3.76; 95% CI: 1.31–10.79; p = 0.014), high human population density (OR: 3.31; 95% CI: 1.20–9.11; p = 0.021), high proportion of buildings built in 1960 or before (OR: 11.21; 95% CI: 2.06–60.89; p = 0.005), and a moderate number of reports of uncollected garbage compared to a low number of reports (OR: 4.88; 95% CI: 1.01–23.63; p = 0.049). A negative association was observed between median household income and Bartonella spp. infection in rats (OR: 0.26; 95% CI: 0.08–0.89; p = 0.031). Conclusions: Due to the complexity of the ecology of rat‐associated zoonoses, consideration of environmental and sociodemographic factors is of critical importance to better understand the nuances of host–pathogen systems and inform how urban rat surveillance and intervention efforts should be distributed within cities. [ABSTRACT FROM AUTHOR]

Simple Summary: In this study, we performed microbial community ecology analyses of bacteria present in the spleen of six species of rodents in Panama in order to identify taxa with zoonotic potential in the country. Genera of bacteria containing species with zoonotic potential detected in this study included Acinetobacter, Bartonella, Cutibacterium, Enterococcus, and Staphylococcus. The results obtained are of value for estimating the prevalence and relative abundance of the bacteria found and the potential of different species of rodents as reservoirs of bacterial zoonosis. This study provides information for comparative studies in the Neotropics and other regions of the world and to generate knowledge on the conditions that may drive zoonosis in different rural vs. suburban environmental settings. Emerging zoonotic diseases are one of the main threats to human and animal health. Among the agents with the potential for zoonoses, those of bacterial origin have great relevance in Public Health. Rodents are considered one of the main reservoirs of pathogens that represent a risk to human health or animal species. We used massive 16S ribosomal RNA gene amplicon sequencing to survey bacteria present in the spleen of six species of rodents in Panama in order to identify bacterial taxa with zoonotic potential in the country. We found 3352 bacterial Amplicon Sequence Variants (ASVs, i.e., phylogenetic species) in the spleen of six rodent species surveyed (Liomys adspersus, Melanomys caliginosus, Mus musculus, Proechimys semispinosus, Rattus rattus, Zygodontomys brevicauda). This bacterial community was represented by 25 phyla, 55 classes, 140 orders, 268 families, and 508 genera. The three predominant phyla were Actinobacteria, Firmicutes, and Proteobacteria, and the five predominant classes were Actinobacteria, Alpha- and Gammaproteobacteria, Bacilli, and Clostridia. There were seven high-abundance genera: Acinetobacter, Bartonella, Cutibacterium, Enterococcus, Sarcina, Staphylococcus, and Wolbachia. Genera found with less abundance included Bradyrhizobium, Chryseobacterium, Clostridium, Corynebacterium, Lactobacillus, Pseudonocardia, Rhodococcus, and Sphingomonas. Some of these genera (high or low abundance) have clinical importance. The identification of bacterial taxa with zoonotic potential in rodent species performed here allows us to have surveillance mechanisms for these pathogens and to be able to recognize localities to be prioritized for prevention of transmission and outbreaks, thus being of value for public health in Panama. [ABSTRACT FROM AUTHOR]

Bacterial endocarditis (BE) is a severe infection of the endocardium and cardiac valves caused by bacterial agents in dogs. Diagnosis of endocarditis is challenging due to the variety of clinical presentations and lack of definitive diagnostic tests in its early stages. This study aims to provide a research literature analysis on BE in dogs based on text mining (TM) and topic analysis (TA) identifying dominant topics, summarizing their temporal trend, and highlighting any possible research gaps. A literature search was performed utilizing the Scopus® database, employing keywords pertaining to BE to analyze papers published in English from 1990 to 2023. The investigation followed a systematic approach based on the PRISMA guidelines. A total of 86 records were selected for analysis following screening procedures and underwent descriptive statistics, TM, and TA. The findings revealed that the number of records published per year has increased in 2007 and 2021. TM identified the words with the highest term frequency-inverse document frequency (TF-IDF), and TA highlighted the main research areas, in the following order: causative agents, clinical findings and predisposing factors, case reports on endocarditis, outcomes and biomarkers, and infective endocarditis and bacterial isolation. The study confirms the increasing interest in BE but shows where further studies are needed. [ABSTRACT FROM AUTHOR]

Abstract The Hyphomicrobiales bacterial order (previously Rhizobiales) exhibits a wide range of lifestyle characteristics, including free-living, plant-association, nitrogen-fixing, and association with animals (Bartonella and Brucella). This study explores the diversity and evolutionary strategies of bacteriophages within the Hyphomicrobiales order, comparing animal-associated (AAB) with non-animal-associated bacteria (NAAB). We curated 560 high-quality complete genomes of 58 genera from this order and used the PHASTER server for prophage annotation and classification. For 19 genera with representative genomes, we curated 96 genomes and used the Defense-Finder server to summarize the type of anti-phage systems (APS) found in this order. We analyzed the genetic repertoire and length distributions of prophages, estimating evolutionary rates and comparing intact, questionable, and incomplete prophages in both groups. Analyses of best-fit parameters and bootstrap sensitivity were used to understand the evolutionary processes driving prophage gene content. A total of 1860 prophages distributed in Hyphomicrobiales were found, 695 in AAB and 1165 in the NAAB genera. The results revealed a similar number of prophages per genome in AAB and NAAB and a similar length distribution, suggesting shared mechanisms of genetic acquisition of prophage genes. Changes in the frequency of specific gene classes were observed between incomplete and intact prophages, indicating preferential loss or enrichment in both groups. The analysis of best-fit parameters and bootstrap sensitivity tests indicated a higher selection coefficient, induction rate, and turnover in NAAB genomes. We found 68 types of APS in Hyphomicrobiales; restriction modification (RM) and abortive infection (Abi) were the most frequent APS found for all Hyphomicrobiales, and within the AAB group. This classification of APS showed that NAAB genomes have a greater diversity of defense systems compared to AAB, which could be related to the higher rates of prophage induction and turnover in the latter group. Our study provides insights into the distributions of both prophages and APS in Hyphomicrobiales genomes, demonstrating that NAAB carry more defense systems against phages, while AAB show increased prophage stability and an increased number of incomplete prophages. These results suggest a greater role for domesticated prophages within animal-associated bacteria in Hyphomicrobiales.

Abstract Background Cutaneous bacillary angiomatosis (cBA) is a vascular proliferative disorder due to Bartonella spp. that mostly affects people living with HIV (PLWH), transplanted patients and those taking immunosuppressive drugs. Since cBA is mostly related to these major immunocompromising conditions (i.e., T-cell count impairment), it is considered rare in relatively immunocompetent patients and could be underdiagnosed in them. Moreover, antimicrobial treatment in this population has not been previously investigated. Methods We searched the databases PubMed, Google Scholar, Scopus, OpenAIRE and ScienceDirect by screening articles whose title included the keywords “bacillary” AND “angiomatosis” and included case reports about patients not suffering from major immunocompromising conditions to provide insights about antibiotic treatments and their duration. Results Twenty-two cases of cBA not related to major immunocompromising conditions were retrieved. Antibiotic treatment duration was shorter in patients with single cBA lesion than in patients with multiple lesions, including in most cases macrolides and tetracyclines. Conclusions cBA is an emerging manifestation of Bartonella spp. infection in people not suffering from major immunocompromising conditions. Until evidence-based guidelines are available, molecular tests together with severity and extension of the disease can be useful to personalize the type of treatment and its duration.

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

The diversity and prevalence of canine vector-borne pathogens (VBPs) in Bhutan have to date remained unexplored, whilst recent epidemiological surveys in other South Asian nations have found diseases caused by VBPs to be rife in local dog populations. Importantly, many of such VBPs can infect people as well, with a building body of evidence identifying potentially zoonotic rickettsial organisms infecting humans in Bhutan. Given the lack of data on canine pathogens in Bhutan we employed a suite of deep-sequencing metabarcoding methods using Oxford Nanopore Technologies' MinION™ device to holistically characterise the bacterial, apicomplexan and filarial worm blood-borne pathogens of dogs in the country's south. Of the 95 stray, owned and community dogs sampled 78% (95% CI = 69%–85%) were infected with at least one VBP. Pathogen species detected were highly diverse including the bacteria Mycoplasma haemocanis in 16% (95% CI: 10–24%), Ehrlichia canis in 4% (95% CI: 2–10%), Anaplasma platys in 2% (95% CI: 0.5–7%) of dogs as well as the zoonotic species Bartonella clarridgeiae in 1% (95% CI: 0.1–6%), a potentially novel Bartonella spp. and an Ehrlichia chaffeensis-like bacterium, both in 1% (95% CI: 0.1–6%) of dogs. The apicomplexan haemoparasites Hepatozoon canis in 62% (95% CI: 52–71%), Babesia gibsoni in 45% (95% CI: 36–55%) and Babesia vogeli in 3% (95% CI: 1–9%) of dogs were also detected. Finally, 5% (95% CI: 2–12%) of dogs were found to be infected with the filarioid Acanthocheilonema reconditum and 1% (95% CI: 0.1–6%) with zoonotic Dirofilaria sp. hongkongensis. One canine was found positive to the filarioid Setaria tundra, a species normally found infecting cervids. The elucidated diversity of VBP communities highlights the strength of assumption-free diagnostics, such as metabarcoding, in detecting rare, novel, and unexpected pathogens. This approach to identifying pathogen diversity is of critical importance when investigating regions and populations that have thus far been neglected, with the findings aiding the development of future One Health informed strategies for disease control.

ABSTRACTGram-negative Bartonella species are facultative intracellular bacteria that can survive in the harsh intracellular milieu of host cells. They have evolved strategies to evade detection and degradation by the host immune system, which ensures their proliferation in the host. Following infection, Bartonella alters the initial immunogenic surface-exposed proteins to evade immune recognition via antigen or phase variation. The diverse lipopolysaccharide structures of certain Bartonella species allow them to escape recognition by the host pattern recognition receptors. Additionally, the survival of mature erythrocytes and their resistance to lysosomal fusion further complicate the immune clearance of this species. Certain Bartonella species also evade immune attacks by producing biofilms and anti-inflammatory cytokines and decreasing endothelial cell apoptosis. Overall, these factors create a challenging landscape for the host immune system to rapidly and effectively eradicate the Bartonella species, thereby facilitating the persistence of Bartonella infections and creating a substantial obstacle for therapeutic interventions. This review focuses on the effects of three human-specific Bartonella species, particularly their mechanisms of host invasion and immune escape, to gain new perspectives in the development of effective diagnostic tools, prophylactic measures, and treatment options for Bartonella infections.

Rodents and bats are the most diverse mammal group that host Bartonella species. In the Americas, they were described as harboring Bartonella species; however, they were mostly characterized to the genotypic level. We describe here Bartonella isolates obtained from blood samples of one rodent (Peromyscus yucatanicus from San José Pibtuch, Yucatan) and two bat species (Desmodus rotundus from Progreso, and Pteronotus parnellii from Chamela-Cuitzmala) from Mexico. We sequenced and described the genomic features of three Bartonella strains and performed phylogenomic and pangenome analyses to decipher their phylogenetic relationships. The mouse-associated genome was closely related to Bartonella vinsonii. The two bat-associated genomes clustered into a single distinct clade in between lineages 3 and 4, suggesting to be an ancestor of the rodent-associated Bartonella clade (lineage 4). These three genomes showed