Mapping the tRNA modification landscape of Bartonella henselae Houston I and Bartonella quintana Toulouse.

Transfer RNA (tRNA) modifications play a crucial role in maintaining translational fidelity and efficiency, and they may function as regulatory elements in stress response and virulence. Despite their pivotal roles, a comprehensive mapping of tRNA modifications and their associated synthesis genes is still limited, with a predominant focus on free-living bacteria. In this study, we employed a multidisciplinary approach, incorporating comparative genomics, mass spectrometry, and next-generation sequencing, to predict the set of tRNA modification genes responsible for tRNA maturation in two intracellular pathogens-Bartonella henselae Houston I and Bartonella quintana Toulouse, which are causative agents of cat-scratch disease and trench fever, respectively. This analysis presented challenges, particularly because of host RNA contamination, which served as a potential source of error. However, our approach predicted 26 genes responsible for synthesizing 23 distinct tRNA modifications in B. henselae and 22 genes associated with 23 modifications in B. quintana. Notably, akin to other intracellular and symbiotic bacteria, both Bartonella species have undergone substantial reductions in tRNA modification genes, mostly by simplifying the hypermodifications present at positions 34 and 37. Bartonella quintana exhibited the additional loss of four modifications and these were linked to examples of gene decay, providing snapshots of reductive evolution.

Knowledge and practices related to louse- and flea-borne diseases among staff providing services to people experiencing homelessness in the United States.

BACKGROUND AND AIMS: Louse-borne Bartonella quintana infection and flea-borne murine typhus are two potentially serious vector-borne diseases that have led to periodic outbreaks among people experiencing homelessness in the United States. Little is known about louse- and flea-borne disease awareness and prevention among staff who provide services to the population. We surveyed staff in seven US states to identify gaps in knowledge and prevention practices for these diseases. METHODS AND RESULTS: Surveys were administered to 333 staff at 89 homeless shelters and outreach teams in California, Colorado, Georgia, Maryland, Minnesota, New York and Washington from August 2022 to April 2023. Most participants (>68%) agreed that body lice and fleas are a problem for people experiencing homelessness. About half were aware that diseases could be transmitted by these vectors; however, most could not accurately identify which diseases. Less than a quarter of staff could describe an appropriate protocol for managing body lice or fleas. Misconceptions included that clients must isolate or be denied services until they are medically cleared. CONCLUSIONS: Our findings reveal significant knowledge gaps among staff who provide services to people experiencing homelessness in the prevention and control of louse- and flea-borne diseases. This demonstrates an urgent need for staff training to both reduce disease and prevent unnecessary restrictions on services and housing.

Antibodies to Borrelia burgdorferi and Bartonella species in serum and synovial fluid from people with rheumatic diseases.

Vector-borne infections may underlie some rheumatic diseases, particularly in people with joint effusions. This study aimed to compare serum and synovial fluid antibodies to B. burgdorferi and Bartonella spp. in patients with rheumatic diseases. This observational, cross-sectional study examined paired synovial fluid and serum specimens collected from 110 patients with joint effusion between October 2017 and January 2022. Testing for antibodies to B. burgdorferi (using CDC criteria) and Bartonella spp. via two indirect fluorescent antibody (IFA) assays was performed as part of routine patient care at the Institute for Specialized Medicine (San Diego, CA, USA). There were 30 participants (27%) with positive two-tier B. burgdorferi serology and 26 participants (24%) with IFA seroreactivity (≥1:256) to B. henselae and/or B. quintana. Both B. burgdorferi IgM and IgG were detected more frequently in synovial fluid than serum: 27% of patients were either IgM or IgG positive in synovial fluid, compared to 15.5% in serum (P = 0.048). Conversely, B. henselae and B. quintana antibodies were detected more frequently in serum than synovial fluid; overall only 2% of patients had positive IFA titers in synovial fluid, compared to 24% who had positive IFA titers in serum (P < 0.001). There were no significant associations between B. burgdorferi or Bartonella spp. seroreactivity with any of the clinical rheumatological diagnoses. This study provides preliminary support for the importance of synovial fluid antibody testing for documenting exposure to B. burgdorferi but not for documenting exposure to Bartonella spp. IMPORTANCE: This study focuses on diagnostic testing for two common vector-borne diseases in an affected patient population. In it, we provide data showing that antibodies to B. burgdorferi, but not Bartonella spp., are more commonly found in synovial fluid than serum of patients with joint effusion. Since Lyme arthritis is a common-and sometimes difficult to diagnose-rheumatic disease, improving diagnostic capabilities is of utmost importance. While our findings are certainly not definitive for changes to practice, they do suggest that synovial fluid could be a useful sample for the clinical diagnosis of Lyme disease, and future prospective studies evaluating this claim are warranted.

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

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

Genomic detection and phylogenetic analysis of Bartonella quintana in pet cats from Urmia City, Northwest Iran.

The aim of this study was to investigate the presence and genetic characteristics of Bartonella quintana in pet cats from Urmia City, located in the northwest of Iran. Blood samples were collected from 200 cats, and their age, gender, and breed were noted. Nested-PCR and sequencing were used to identify B. quintana in positive samples, and the ftsZ gene sequences were analyzed using BioEdit software. The gene sequence obtained in this study exhibited 100.00 % similarity to reference sequences in the GenBank® database, and a phylogenetic tree was constructed using MEGA11. The results revealed that 15 % of the cats (30 out of 200 blood samples) tested positive for the B. quintana gene, with a 95 % confidence interval of 10.71 % to 20.61 %.

An autochthonous case of cutaneous bacillary angiomatosis not related to major immunosuppression: An emerging or overlooked disease?

Cutaneous bacillary angiomatosis (cBA) is a vascular proliferative disorder due to Bartonella henselae or Bartonella quintana that has been mostly described in people living with HIV. Since cBA is considered to be rare in hosts not affected by major immunosuppression, it could be underdiagnosed in this population. Moreover, antimicrobial treatment of cBA has been poorly validated, thus reporting experiences on this clinical entity is important. We reported a challenging and well-characterized case of an Italian 67-year-old gentleman without a history of major immunocompromizing conditions, although he was affected by conditions that can be associated with impaired immune function. The patient reported herein was diagnosed after a long time since the initiation of symptoms and was successfully treated with combined antibiotic therapy including macrolides and quinolones under the guidance of molecular test results. Physicians should consider cBA as a possible manifestation of Bartonella spp. Infection in patients not suffering from major immunocompromizing 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.

Molecular detection of Bartonella quintana, Acinetobacter baumannii and Acinetobacter haemolyticus in Pediculus humanus lice in Nigeria, West Africa.

The human lice Pediculus humanus is distributed worldwide but, it thrives and flourishes under conflict situations where people are forced to live in crowded unhygienic conditions. Molecular methods were used to identify and screen human lice for the DNA of pathogens of public health importance in an area that has been under insurgency related to religious and political conflicts with tens of thousands of internally displaced people (IDP). DNA of Bartonella quintana, Acinetobacter baumannii and Acinetobacter haemolyticus was detected in 18.3%, 40.0% and 1.7%, respectively, of human lice collected from children in Maiduguri, Nigeria. More body lice than head lice were positive for pathogen's DNA (64.3% vs. 44.4%; χ2 = 1.3, p = 0.33), but the difference was not significant. Two lice samples were found to harbour mixed DNA of B. quintana and A. baumannii. Phylogenetic analysis of the cytochrome b (cytb) gene sequences of the positive lice specimens placed them into clades A and E. This is the first report on the molecular identification of human lice and the detection of the DNA of pathogens of public health importance in lice in Nigeria, West Africa. The findings of this study will assist policy makers and medical practitioners in formulating a holistic healthcare delivery to IDPs.

Presumed acute posterior multifocal placoid pigmentary epitheliopathy associated with Bartonella infection / Epiteliopatia pigmentar placoide multifocal posterior aguda presumível associada com infecção por Bartonella

ABSTRACT To report a unique case of acute posterior multifocal placoid pigment epitheliopathy (APMPPE) in a patient with positive serology for Bartonella, presenting with ocular signs and symptoms not attributable to other diseases. A 27-year-old woman presented with decreased visual acuity in both eyes. Multimodal fundus image analysis was performed. A color fundus photograph of both eyes revealed peripapillary and macular yellow-white placoid lesions. The fundus autofluorescence of both eyes demonstrated hypo- and hyperautofluorescence of the macular lesions. Fluorescein angiography showed early-stage hypofluorescence and late staining of placoid lesions in both eyes. Spectral domain optical coherence tomography (SD-OCT) of both eyes revealed irregular elevations in the retinal pigment epithelium with the disruption of the ellipsoid zone on the topography of macular lesions. At 3 months after the treatment initiation for Bartonella infection, the placoid lesions became atrophic and hyperpigmented, and SD-OCT revealed loss of both the outer retinal layers and retinal pigment epithelium on the topography of macular lesions in both eyes.

RESUMO Caso de epiteliopatia pigmentada placoide multifocal posterior aguda presumida em paciente com sorologia positiva para Bartonella. Paciente feminina de 27 anos apresentou diminuição da acuidade visual em ambos os olhos. Análise multimodal de imagem foi realizada. A retinografia mostrou revelou lesões placoides amarelo-esbranquiçadas nas áreas peripapilar e macular de ambos os olhos. A autofluorescência demonstrou hipo e hiperautofluorescência em ambos os olhos, na mesma topografia das lesões detectadas na retinografia. A angiofluoresceínografia mostrou hipofluorescência na fase inicial do exame e hiperfluorescência tardia das lesões placoides em ambos os olhos. A tomografia de coerência óptica de domínio espectral de ambos os olhos revelou elevações irregulares do epitélio pigmentado da retina com descontinuação da zona elipsoide na área macular. Três meses após o início do tratamento para infecção por Bartonella, as lesões placoides tornaram-se atróficas e hiperpigmentadas, e a tomografia de coerência óptica revelou perda das camadas externas da retina e do epitélio pigmentado da retina na topografia das lesões maculares em ambos os olhos.

Development of a quadruplex PCR amplicon next generation sequencing assay for detection and differentiation of Bartonella spp.

The genus Bartonella includes a group of species that are associated with a wide range of mammalian species, including human. It is challenging to detect all Bartonella species using a single molecular target due to its high genetic diversity. To solve this issue, we developed a quadruplex PCR amplicon sequencing assay using next-generation sequencing (NGS) technology for the detection and differentiation of Bartonella species. Our objective was to obtain the specific sequences of a minimum of two of the four target genes as confirmation of the identity of a particular Bartonella species using the assay. Four pairs of primers targeting specific regions on gltA, groEL, rpoB, and ssrA were evaluated for their capability of differentiating Bartonella species individually and collectively by performing singular PCR amplicon sequencing and quadruplex PCR amplicon sequencing. Using the quadruplex PCR amplicon sequencing, 24 Bartonella reference species were tested, all of which were successfully differentiated by at least two targets. Bartonella species were accurately identified from the artificially mixed DNA templates developed to simulate coinfections. The limit of detection was determined to be 1 fg based on testing a series of 10-fold dilutions of DNA from the Bartonella species. Testing of high DNA concentrations of 19 non-Bartonella species showed high specificity with none of the non-Bartonella species misclassified as Bartonella. Finally, the assay was evaluated by testing DNA extracts from field-collected body lice (Pediculus humanus humanus) and Norway rats (Rattus norvegicus): Bartonella quintana was detected and confirmed by three targets in the lice and Bartonella tribocorum was detected and confirmed by two targets in the rats. These results demonstrated that Bartonella species could be accurately and rapidly detected and differentiated into different tissue types using the quadruplex sequencing assay.

Evidence for Bartonella quintana in Lice Collected from the Clothes of Ethiopian Homeless Individuals.

Human lice, Pediculus humanus, can transmit various pathogens, including Bartonella quintana, Borrelia recurrentis, and Rickettsia prowazekii. Xenosurveillance is an epidemiological approach to assessing human infection risks performed by screening vectors of infectious disease agents. In the proof-of-principle study reported herein, the DNA of 23 human lice was collected from the clothes of 30 homeless Ethiopian individuals. These samples were assessed using 16S rRNA gene-specific pan-eubacterial PCR for screening, followed by Bartonella genus 16S-23S internal transcribed spacer (ITS) sequence-specific PCR, Bartonella genus gltA gene-specific PCR, and 16S rRNA gene PCR with specificity for relapsing-fever-associated Borrelia spp. with subsequent sequencing of the amplicons. In one sample, the pan-eubacterial 16S rRNA gene-specific screening PCR, the Bartonella genus 16S-23S ITS sequence-specific PCR, and the Bartonella genus gltA gene-specific PCR allowed for the sequencing of B. quintana-specific amplicons. In two additional samples, Bartonella genus gltA gene-specific PCR also provided sequences showing 100% sequence identity with B. quintana. In total, 3/23 (13.0%) of the assessed lice were found to be positive for B. quintana. Correlating clinical data were not available; however, the assessment confirmed the presence of B. quintana in the local louse population and thus an associated infection pressure. Larger-sized cross-sectional studies seem advisable to more reliably quantify the infection risk of lice-infested local individuals. The need for prevention by providing opportunities to maintain standard hygiene for Ethiopian homeless individuals is stressed by the reported findings, especially in light of the ongoing migration of refugees.

Species diversity and detection of pathogens in phlebotomine sand flies collected from forest management areas of Quintana Roo, Mexico.

Sand flies have expanded their areas of distribution, thereby increasing the risk of pathogen transmission in non-endemic areas. To establish efficient prevention and control strategies for the transmission of vector-borne pathogens, it is important to understand seasonal dynamics of their vectors. In Mexico, there are several areas where the contact between sand flies, hosts and reservoirs favours the transmission of the pathogen. We compared sand fly communities in a forest management area and a conserved area in Noh-Bec, Quintana Roo, Mexico. The analysis included species diversity, activity peaks and molecular detection of pathogens. Sand flies were collected from November to December 2021 and April to May 2022, during 84 night-traps. The conserved area showed higher numbers and greater species heterogeneity of sand flies as compared with the other sites. The ß-diversity analysis revealed that sites disturbed by logging (S1, S2, S3) had greater similarity (90%) in their sand fly species composition than a conserved area (S4) (similarity = 36%). Although none of the specimens were infected with Leishmania, we detected Wolbachia (19.4%) in all four sites, as well as Bartonella (3.25%) only in the disturbed sites. Further studies on the dynamics of sand fly populations and their association with pathogens are necessary.

Exploring the potential role of defensins in differential vector competence of body and head lice for Bartonella quintana.

BACKGROUND: The body and head lice of humans are conspecific, but only the body louse functions as a vector to transmit bacterial pathogens such as Bartonella quintana. Both louse subspecies have only two antimicrobial peptides, defensin 1 and defensin 2. Consequently, any differences in the molecular and functional properties of these two louse subspecies may be responsible for the differential vector competence between them. METHODS: To elucidate the molecular basis of vector competence, we compared differences in the structural properties and transcription factor/microRNA binding sites of the two defensins in body and head lice. Antimicrobial activity spectra were also investigated using recombinant louse defensins expressed via baculovirus. RESULTS: The full-length amino acid sequences of defensin 1 were identical in both subspecies, whereas the two amino acid residues in defensin 2 were different between the two subspecies. Recombinant louse defensins showed antimicrobial activities only against the representative Gram-positive Staphylococcus aureus but not against either Gram-negative Escherichia coli or the yeast Candida albicans. However, they did show considerable activity against B. quintana, with body louse defensin 2 being significantly less potent than head louse defensin 2. Regulatory sequence analysis revealed that the gene units of both defensin 1 and defensin 2 in body lice possess decreased numbers of transcription factor-binding sites but increased numbers of microRNA binding sites, suggesting relatively lower transcription activities of body louse defensins. CONCLUSIONS: The significantly lower antibacterial activities of defensin 2 along with the reduced probability of defensin expression in body lice likely contribute to the relaxed immune response to B. quintana proliferation and viability, resulting in higher vector competence of body lice compared to head lice.

Invasive bacillary angiomatosis in a kidney transplant recipient: A challenging case on belatacept immunosuppression.

Bacillary angiomatosis is a disseminated vascular proliferative disease caused by aerobic gram-negative bacilli Bartonella henselae or Bartonella quintana. Bacillary angiomatosis is mostly described in immunosuppressed patients with HIV infection and organ transplant recipients. We describe the case of a female aged 75 years who is a kidney transplant recipient who was admitted for a 3-month history of intermittent fever, chills, vomiting, and a 12-kg weight loss. The maintenance immunosuppression was based on prednisone, mycophenolate, and monthly infusions of belatacept. Physical examination was unremarkable. Laboratory investigations revealed elevated blood acute phase proteins but all blood cultures were negative. Serological tests for Bartonella were negative. Thoracoabdominal computed tomography scan and transesophageal echocardiography were normal. A Positron Emission Tomography scan showed a hypermetabolic mass in the duodenopancreatic region, with multiple hepatic and splenic lesions. Histological findings of spleen and pancreatic biopsies were not conclusive. The histopathological examination of a celiac lymph node biopsy finally demonstrated bacillary angiomatosis. The diagnosis of bacillary angiomatosis in immunocompromised patients is most often delayed in the absence of skin involvement. A high index of clinical suspicion is needed when interpreting negative results.

Effects of selected blood-derived factors on innate immunity in the human body louse.

BACKGROUND: The human body louse (Pediculus humanus humanus) is a host-specific hematophagous ectoparasite that frequently infests populations experiencing a breakdown of hygienic conditions. Body lice are also vectors for several bacterial human pathogens, including Bartonella quintana, the agent of trench fever. However, the factors that influence immunity and infection in body lice are poorly understood. Human infection with B. quintana is associated with alcoholism and homelessness and can coincide with elevated circulating levels of the cytokine IL-10 and the inflammatory marker neopterin. Hematophagous arthropods are capable of responding physiologically and immunologically to a variety of biomolecules present in the blood of their hosts. Therefore, we sought to investigate whether ingestion of alcohol, its metabolic product acetaldehyde, IL-10 or neopterin could affect innate immunity and infection in the body louse. METHODS: Groups of lice were provisioned multiple blood meals containing physiological concentrations of alcohol, acetaldehyde, IL-10 or neopterin, and expression of six previously identified immunity-related genes (Defensin 1, Defensin 2, Prophenoloxidase, Hemocytin, Noduler and Dual Oxidase) was examined by qRT-PCR. RESULTS: Alcohol, acetaldehyde and IL-10 had no significant effects on gene expression relative to blood-fed controls while ingestion of neopterin significantly downregulated expression of Defensin 1 and Defensin 2. Nonetheless, ingestion of neopterin concurrent with B. quintana had no significant effect on the load of infection, indicating that neopterin-induced repression of Defensin expression is insufficient to reduce resistance to the pathogen. CONCLUSIONS: Our findings demonstrate that the immune system of body lice can be affected by factors present in the blood of their human hosts and suggest potential conservation of the function of some immune molecules from human host to ectoparasite. Further, the discord between the effects of neopterin on immunity-related gene expression and B. quintana load highlights the complexity of the regulation of pathogen infection in the louse vector.

Molecular epidemiology of Bartonella quintana endocarditis in patients from Israel and Eastern Africa.

BACKGROUND: Bartonella quintana is an important cause of culture-negative endocarditis. Although humans have been considered as its only reservoir, recent studies showed that macaque species are also reservoirs of B. quintana. Based on multi-locus sequence typing (MLST) B. quintana strains have been classified into 22 sequence types (STs), with 7 STs exclusively found in humans. Data regarding the molecular epidemiology of B. quintana endocarditis is limited to only 3 STs identified in 4 patients from Europe and Australia. We studied B. quintana endocarditis acquired in Eastern Africa or Israel to investigate the genetic diversity and clinical relatedness of B. quintana from distinct geographic regions. METHODS: Eleven patients with B. quintana endocarditis, 6 from Eastern Africa and 5 from Israel, were studied. DNA was extracted from cardiac tissue or blood specimens and analyzed by MLST based on 9 genetic loci. An evolutionary relationship between STs was visualized by a minimum spanning tree. A phylogenetic tree was constructed with the concatenated sequences (4271 bp) of the 9 loci using the maximum-likelihood method. RESULTS: Six strains were classified into previously described STs while 5 strains were identified for the first time and classified into new STs 23-27 which clustered with the previously reported STs 1-7 from human strains found in Australia, France, Germany, the USA, Russia, and the former Yugoslavia, without indication of geographical structuring. ST2 was the most prevalent ST, found in 5 of 15 patients with endocarditis (33.3%). ST26 appears to be a primary founder of the human lineage. CONCLUSIONS: The new and previously reported human STs form a single human lineage, clearly separated from the other 3 B. quintana lineages of cynomolgus, rhesus, and Japanese macaques. From evolutionary perspectives, these findings support the assumption that B. quintana has co-evolved with host species to form a host-speciation pattern. ST26 is suggested herein as a primary founder of the human lineage and may be key to explore where B. quintana had first originated; ST2 is a dominant genetic type associated with B. quintana endocarditis. To confirm these findings, additional worldwide molecular epidemiological studies are required.

The autotransporter BafA contributes to the proangiogenic potential of Bartonella elizabethae.

Bartonella elizabethae is a rat-borne zoonotic bacterium that causes human infectious endocarditis or neuroretinitis. Recently, a case of bacillary angiomatosis (BA) resulting from this organism was reported, leading to speculation that B. elizabethae may also trigger vasoproliferation. However, there are no reports of B. elizabethae promoting human vascular endothelial cell (EC) proliferation or angiogenesis, and to date, the effects of this bacterium on ECs are unknown. We recently identified a proangiogenic autotransporter, BafA, secreted from B. henselae and B. quintana, which are recognized as Bartonella spp. responsible for BA in humans. Here, we hypothesized that B. elizabethae also harbored a functional bafA gene and examined the proangiogenic activity of recombinant B. elizabethae-derived BafA. The bafA gene of B. elizabethae, which was found to share a 51.1% amino acid sequence identity with BafA of B. henselae and 52.5% with that of B. quintana in the passenger domain, was located in a syntenic region of the genome. The recombinant protein of the N-terminal passenger domain of B. elizabethae-BafA facilitated EC proliferation and capillary structure formation. Furthermore, it upregulated the receptor signaling pathway of vascular endothelial growth factor, as observed in B. henselae-BafA. Taken together, B. elizabethae-derived BafA stimulates human EC proliferation and may contribute to the proangiogenic potential of this bacterium. So far, functional bafA genes have been found in all BA-causing Bartonella spp., supporting the key role BafA may play in BA pathogenesis.

Bartonella spp. Infections Identified by Molecular Methods, United States.

Molecular methods can enable rapid identification of Bartonella spp. infections, which are difficult to diagnose by using culture or serology. We analyzed clinical test results of PCR that targeted bacterial 16S rRNA hypervariable V1-V2 regions only or in parallel with PCR of Bartonella-specific ribC gene. We identified 430 clinical specimens infected with Bartonella spp. from 420 patients in the United States. Median patient age was 37 (range 1-79) years; 62% were male. We identified B. henselae in 77%, B. quintana in 13%, B. clarridgeiae in 1%, B. vinsonii in 1%, and B. washoensis in 1% of specimens. B. quintana was detected in 83% of cardiac specimens; B. henselae was detected in 34% of lymph node specimens. We detected novel or uncommon Bartonella spp. in 9 patients. Molecular diagnostic testing can identify Bartonella spp. infections, including uncommon and undescribed species, and might be particularly useful for patients who have culture-negative endocarditis or lymphadenitis.