Infectious endocarditis caused by Bartonella henselae associated with infected pets: two case reports.

BACKGROUND: Blood culture-negative infective endocarditis is a potentially severe disease that can be associated with infectious agents such as Bartonella spp., Coxiella burnetti, Tropheryma whipplei, and some fungi. CASE PRESENTATION: Reported here are two cases of blood culture-negative infective endocarditis in patients with severe aortic and mitral regurgitation in Brazil; the first case is a 47-year-old white man and the second is a 62-year-old white woman. Bartonella henselae deoxyribonucleic acid was detectable in the blood samples and cardiac valve with vegetation paraffin-fixed tissue samples. Additionally, an investigation was carried out on patients' pets, within the context of One Health, and serum samples collected from cats and dogs were reactive by indirect immunofluorescence assay. CONCLUSIONS: Even though the frequency of bartonellosis in Brazil is unknown, physicians should be aware of the possibility of blood culture-negative infective endocarditis caused by Bartonella, particularly in patients with weight loss, kidney changes, and epidemiological history for domestic animals.

Identification of Immunogenic Linear B-Cell Epitopes in C. burnetii Outer Membrane Proteins Using Immunoinformatics Approaches Reveals Potential Targets of Persistent Infections.

Coxiella burnetii is a global, highly infectious intracellular bacterium, able to infect a wide range of hosts and to persist for months in the environment. It is the etiological agent of Q fever-a zoonosis of global priority. Currently, there are no national surveillance data on C. burnetii's seroprevalence for any South American country, reinforcing the necessity of developing novel and inexpensive serological tools to monitor the prevalence of infections among humans and animals-especially cattle, goats, and sheep. In this study, we used immunoinformatics and computational biology tools to predict specific linear B-cell epitopes in three C. burnetii outer membrane proteins: OMP-H (CBU_0612), Com-1 (CBU_1910), and OMP-P1 (CBU_0311). Furthermore, predicted epitopes were tested by ELISA, as synthetic peptides, against samples of patients reactive to C. burnetii in indirect immunofluorescence assay, in order to evaluate their natural immunogenicity. In this way, two linear B-cell epitopes were identified in each studied protein (OMP-H(51-59), OMP-H(91-106), Com-1(57-76), Com-1(191-206), OMP-P1(197-209), and OMP-P1(215-227)); all of them were confirmed as naturally immunogenic by the presence of specific antibodies in 77% of studied patients against at least one of the identified epitopes. Remarkably, a higher frequency of endocarditis cases was observed among patients who presented an intense humoral response to OMP-H and Com-1 epitopes. These data confirm that immunoinformatics applied to the identification of specific B-cell epitopes can be an effective strategy to improve and accelerate the development of surveillance tools against neglected diseases.

Serological evidence of Bartonellosis in an indigenous community in the Brazilian Legal Amazonia.

BACKGROUND: Due to immunological susceptibility, close contact with the environment and way of life, indigenous communities are in a highly vulnerable condition to be affected by zoonoses, such as bartonellosis. METHODS: Seventy three paired serum samples were collected from indigenous people from a region of the Brazilian Legal Amazon, in cohorts carried out in 2014 and 2015, with the performance of serological tests by indirect immunofluorescence to detect anti-Bartonella IgG antibodies. The interviews and laboratory results were double entered in the EpiInfo 7 software, and the data processing was performed in the MiniTab 17 software. RESULTS: 5.47% of the indigenous people were seroreagent. The female gender was predominant (65.75%), aged between 20 and 39 years old (39.73%) with complete elementary school (42.47%). As for housing, wooden residences predominated (50.68%). Rodents were seen by 46.58% of the interviewees, and 55.88% of them reported that the animal was close to or inside the house. It was identified that each indigenous family, in its majority, had four to six cats, for the function of hunters of rodents. CONCLUSION: The high concentration of domestic cats, the close contact of indigenous people with wild rodents and the lack of care and poor hygiene of both are aspects that imply the possibility of infection by Bartonella sp. Health surveillance through seroepidemiological studies is essential to find evidence of the circulation of bartonellosis in these populations.

Coxiella and Bartonella spp. in bats (Chiroptera) captured in the Brazilian Atlantic Forest biome.

BACKGROUND: The role of bats as reservoirs of zoonotic agents, especially pathogenic bacteria such as Bartonella and Coxiella, has been discussed around the world. Recent studies have identified bats as potential hosts of species from the proteobacteria phylum. In Brazil, however, the role of bats in the natural cycle of these agents is poorly investigated and generally neglected. In order to analyze the participation of bats in the epidemiology of diseases caused by Bartonella, Coxiella, Rickettsia, Anaplasma and Ehrlichia, we conducted a descriptive epidemiological study in three biogeographic regions of the Brazilian Atlantic Forest. RESULTS: Tissues of 119 bats captured in preserved areas in the states of Rio de Janeiro, Bahia and Santa Catarina from 2014 to 2015 were submitted to molecular analysis using specific primers. Bartonella spp. was detected in 22 spleen samples (18.5%, 95% CI: 11.9-26.6), whose phylogenetic analysis revealed the generation of at least two independent clusters, suggesting that these may be new unique genotypes of Bartonella species. In addition, four samples (3.4%, 95% CI: 0.9-8.3) were positive for the htpAB gene of C. burnetii [spleen (2), liver (1) and heart (1)]. Rickettsia spp., Anaplasma and Ehrlichia were not identified. This is the first study reporting C. burnetii and Bartonella spp. infections in bats from the Atlantic Forest biome. CONCLUSIONS: These findings shed light on potential host range for these bacteria, which are characterized as important zoonotic pathogens.

Q Fever in Military Firefighters during Cadet Training in Brazil.

We report five cases of Q fever among cadets during a training program for Military Firefighters Academy in the state of Rio de Janeiro, Brazil. This cluster confirms the significance of Coxiella burnetii as an infectious agent in Brazil, where the occurrence of this zoonosis is poorly documented and highlights the potential risk for Q fever transmission in rural areas or farms with infected animals.