Risk Factors for Bartonella species Infection in Blood Donors from Southeast Brazil

Blood Supplementation Enhances Bartonella henselae Growth and Molecular Detection of Bacterial DNA in Liquid Culture

Bacteria of the genus Bartonella, a member of the Alphaproteobacteria, are fastidious, Gram-negative, aerobic bacilli that comprise numerous species, subspecies, and genotypes. Bartonella henselae, with a worldwide distribution, infects cats, dogs, horses, humans, and other mammals. Diagnostically, direct detection of Bartonella henselae in patient blood specimens by culture or molecular methods is required to confirm infection with this bacterium. Enrichment blood culture combined with quantitative PCR (qPCR) or ddPCR enhances the sensitivity of direct detection. The addition of sheep blood to liquid culture media increased the Bartonella henselae DNA concentration compared to controls, additionally improving PCR direct detection sensitivity. IMPORTANCE This study aims to improve diagnostic detection of Bartonella henselae. Patient samples are combined with enriched bacterial cultures aimed at growing Bartonella henselae for the best possible chance at detection. However, current Bartonella growth methods could be improved. The DNA extraction method used by most laboratories should also be optimized. Sheep blood was added to increase the growth of Bartonella henselae and multiple DNA extraction methods were to be compared to each other.

Bartonella spp. in households with cats: Risk factors for infection in cats and human exposure

The aim of this study was to estimate the occurrence of Bartonella spp. per household in cats and the risk factors for Bartonella spp. positivity in cats and their owners from Valdivia, Chile. A total of 464 cats (distributed within 324 households) and 326 humans (control group [n = 112] and cat owner [n = 214]) distributed in 262 households were sampled. From the cat owners (n = 214), 128 humans were in households where the cat was also sampled, totaling 84 households with dual sampling. Real-time PCR (qPCR) was used for Bartonella spp. detection in blood from cats and humans, and immunofluorescent immunoassay (IFA) anti-Bartonella henselae was performed in human serum samples. Out of the total of 324 households, 20.43% presented at least one Bartonella positive cat. From the households with dual sampling, 29.7% (25/84) presented at least one qPCR-Bartonella spp. positive cat. However, Bartonella DNA was not amplified in humans, and in 7.3% (6/82) of the households was found at least one of the cat's owners exposed to B. henselae. Cats younger than one year (Odds Ratio (OR) = 5.3), non-neutered (OR 3.46), sampled at home (OR 5.82), and with improper application of tick/flea control products (OR 3.13) showed a higher risk for Bartonella spp. presence. Humans with occupational exposure involving animal contact, were more likely to exhibit B. henselae seropositivity (OR 7.5). Bartonella spp. was present in the cats a moderate number of households, but Bartonella DNA was not detected in owners' blood, inferring that there is a low risk of recent human infection in the studied population.

Comparison of molecular methods for Bartonella henselae detection in blood donors

The Bartonella genus consists of neglected pathogens associated with potentially transfusional-transmitted and fatal human diseases. We aimed to evaluate Bartonella sp. prevalence in 500 blood donors and compare the results with the data already published about these samples. We used molecular diagnostic methods to detect Bartonella sp.-DNA from blood and liquid culture samples: (A) conventional PCR for two gene regions, the ITS targeting the genus Bartonella and the specific gltA Bartonella henselae; (B) nested PCR for the ftsZ gene and (C) qualitative real-time PCR for the gltA gene, both B. henselae specific. We obtained 30/500 (6%) DNA detections from the blood samples; 77/500 (15.4%) DNA detections from liquid culture samples and five (1%) samples had DNA detection from both. In total, we detected B. henselae DNA from 102/500 (20.4%) donors. The samples used in this study had already been submitted for Bartonella sp.-DNA detection using only a conventional PCR in liquid culture. Sixteen samples (3.2%) were positive previously, and from these 16 samples, 13 were negative in the new investigation. We concluded that the use of liquid culture combined with different molecular tests increases the possibility of detecting Bartonella sp.-DNA, but the tests do not avoid false-negative results. More than a fifth of blood donors had at least one PCR that detected Bartonella sp.-DNA among the eight molecular reactions performed now (four reactions in whole blood and four in liquid culture). Seven percent had B. henselae-DNA detection for two or more distinct regions. Considering the results obtained previously, the DNA of Bartonella spp. was detected or the agent isolated in 23% of analyzed blood donors. The results establish that the low bacteremia and the fastidious characteristics of the bacterium are challenges to laboratory diagnosis and can make it difficult to confirm the infection in patients with bartonelloses.

Detection of Bartonella henselae DNA in the blood of patients with livedoid vasculopathy

BACKGROUND

Livedoid vasculopathy (LV) manifests as ulcers and atrophic white scars on the lower extremities. The main known etiopathogenesis is hypercoagulability with thrombus formation, followed by inflammation. Thrombophilia, collagen and myeloproliferative diseases may induce LV, but the idiopathic (primary) form predominates. Bartonella sp. may cause intra-endothelial infection and skin manifestations caused by these bacteria may be diverse, including leukocytoclastic vasculitis and ulcers.

OBJECTIVE

The aim of this study was to investigate the presence of bacteremia by Bartonella spp. in patients with difficult-to-control chronic ulcers diagnosed as primary LV.

METHODS

Questionnaires and molecular tests (conventional PCR, nested PCR and real-time PCR) were applied and liquid and solid cultures were performed in the blood samples and blood clot of 16 LV patients and 32 healthy volunteers.

RESULTS

Bartonella henselae DNA was detected in 25% of LV patients and in 12.5% of control subjects but failed to reach statistically significant differences (p = 0.413).

STUDY LIMITATIONS

Due to the rarity of primary LV, the number of patients studied was small and there was greater exposure of the control group to risk factors for Bartonella spp.

INFECTION

CONCLUSION

Although there was no statistically significant difference between the groups, the DNA of B. henselae was detected in one of every four patients, which reinforces the need to investigate Bartonella spp. in patients with primary LV.

Bartonella Associated Cutaneous Lesions (BACL) in People with Neuropsychiatric Symptoms

Bartonella species are globally important emerging pathogens that were not known to infect animals or humans in North America prior to the human immunodeficiency virus (HIV) epidemic. Ongoing improvements in diagnostic testing modalities have allowed for the discovery of Bartonella species (spp.) DNA in blood; cerebrospinal fluid; and the skin of patients with cutaneous lesions, fatigue, myalgia, and neurological symptoms. We describe Bartonella spp. test results for participants reporting neuropsychiatric symptoms, the majority of whom reported the concurrent development of cutaneous lesions. Study participants completed a medical history, a risk factor questionnaire, and provided cutaneous lesion photographs. Bartonella spp. serology and Bartonella alpha proteobacteria enrichment blood culture/PCR were assessed. Within a 14-month period, 33 participants enrolled; 29/33 had serological and/or PCR evidence supporting Bartonella spp. infection, of whom 24 reported concurrent cutaneous lesions since neuropsychiatric symptom onset. We conclude that cutaneous lesions were common among people reporting neuropsychiatric symptoms and Bartonella spp. infection or exposure. Additional studies, using sensitive microbiological and imaging techniques, are needed to determine if, or to what extent, Bartonella spp. might contribute to cutaneous lesions and neuropsychiatric symptoms in patients.

The clinical spectrum of ocular bartonellosis: a retrospective study at a tertiary centre in Malaysia

BACKGROUND

Cat scratch disease (CSD) is a systemic illness caused by the gram-negative bacillus, Bartonella henselea, which can occasionally involve the ocular structures. The objective of this study is to evaluate the various clinical presentations of ocular bartonellosis at our institution. A retrospective review of the clinical records of 13 patients (23 eyes) with ocular manifestations of Bartonella infections over a 3-year period between January 2016 to December 2018 was undertaken at our institution.

RESULTS

The diagnosis was made based on clinical findings and in addition, with the support of the evidence of Bartonella hensalae IgG and/or IgM. Small retinal white lesions were the most common ocular findings in this series of patients (82.6% of eyes, 76.9% of patients). Neuroretinitis was the second most common finding (47.8% of eyes, 69.2% of patients), followed by exudative retinal detachment involving the macula (34.8% of eyes, 53.8% of patients) and Parinaud's oculoglandular syndrome (17.4% of eyes, 23.1% of patients). Other findings like isolated optic disc oedema without macular star (8.7% of eyes, 15.4% of patients) and vitritis (4.3% of eyes, 7.7% of patients) were also observed. Ten patients (76.9%) had bilateral ocular involvement. Most of the patients were young, immunocompetent and had systemic symptoms like fever prior to their ocular symptoms. The visual acuity (VA) at initial presentation ranged from 6/6 to hand movement (mean, 6/20), and at final visit 6/6 to 6/60, (mean, 6/9). 91.7% of patients were treated with antibiotics. Only 2 patients received oral corticosteroids together with antibiotics due to very poor vision on presentation. The visual prognosis of ocular bartonellosis is generally good with 16 (88.9%) of 23 eyes having VA of 6/12 or better at final follow-up visit.

CONCLUSION

Small foci of retinal white lesions were the most common manifestation of ocular bartonellosis in this series, followed by neuroretinitis, though an array of other ocular findings may also occur. Therefore, we should consider bartonella infection as a possible differential diagnosis in those patients.

Investigation of Bartonella spp. in brazilian mammals with emphasis on rodents and bats from the Atlantic Forest

The Bartonella species are zoonotic agents that infect mammals and are transmitted by arthropod vectors. Approximately 18 distinct genotypes cause diseases in humans, and may be spread by both domestic and wild animals. In Brazil, Bartonella genotypes have been identified in several species of wild mammals, and in the present study, we analyzed samples from non-human primates (marmosets), marsupials, rodents, and bats, and compared them with the genotypes described in mammals from Brazil, to examine the distribution of Bartonella genotypes in two impacted areas of Rio de Janeiro state, in southeastern Brazil. We used polymerase chain reaction (PCR) methods to detect the Bartonella DNA using partial sequences of the gltA, ftsZ, and groEL genes. We generated Bayesian inference and maximum likelihood trees to characterize the positive PCR samples and infer the phylogenetic relationships of the genotypes. A total of 276 animals were captured, including 110 bats, 91 rodents, 38 marsupials, and 37 marmosets. The DNA of Bartonella was amplified from tissue samples collected from 12 (4.34%) of the animals, including eight rodents – Akodon cursor (5/44) and Nectomys squamipes (3/27) – and four bats, Artibeus lituratus (3/58) and Carollia perspicillata (1/15). We identified Bartonella genotypes closely related to those described in previous studies, as well as new genotypes in both the rodent and the bat samples. Considering the high diversity of the Bartonella genotypes and hosts identified in the present study, further research is needed to better understand the relationships between the different Bartonella genotypes and their vectors and host species. The presence of Bartonella in the wild rodents and bats from the study area indicates that the local human populations may be at risk of infection by Bartonella due to the spillover of these strains from the wild environment to domestic and peri-domestic environments.

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First record of wild mammals with Bartonella DNA at northwestern of Rio de Janeiro.

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The genotypes of Bartonella were characterized in two species of cricetid rodents and two species of phyllostomid bats from Rio de Janeiro.

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The genotype of Bartonella in Akodon cursor was identified closely related to B. rochalimae.

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This is the first report of Bartonella in C. perspicillata from Rio de Janeiro state, based on the analysis of tissue samples.

Bartonella spp. Prevalence (Serology, Culture, and PCR) in Sanitary Workers in La Rioja Spain

Bartonella spp. are increasingly implicated in association with a spectrum of zoonotic infectious diseases. One hundred sanitary workers in La Rioja, Spain completed a questionnaire and provided blood specimens for Bartonella spp. serology and Bartonella alpha-Proteobacteria growth medium (BAPGM) enrichment blood culture/PCR. Six immunofluorescence assays (IFA) were performed and aseptically obtained blood specimens were inoculated into liquid BAPGM and subcultured onto blood agar plates. Bartonella DNA was amplified using conventional and real-time PCR assays. The Bartonella spp., strain, or genotype was determined by DNA sequencing. Bartonella seroreactivity was documented in 83.1% and bloodstream infection in 21.6% of participants. Bartonella henselae, B. vinsonii subsp. berkhoffii genotypes I and III, and B. quintana were identified. IFA seroreactivity and PCR positivity were not statistically associated with self-reported symptoms. Our results suggest that exposure to and non-clinical infection with Bartonella spp. may occur more often than previously suspected in the La Rioja region.

Cutaneous manifestations of bartonellosis

Bartonellosis are diseases caused by any kind of Bartonella species. The infection manifests as asymptomatic bacteremia to potentially fatal disorders. Many species are pathogenic to humans, but three are responsible for most clinical symptoms: Bartonella bacilliformis, Bartonella quintana, and Bartonella henselae. Peruvian wart, caused by B. bacilliformis, may be indistinguishable from bacillary angiomatosis caused by the other two species. Other cutaneous manifestations include maculo-papular rash in trench fever, papules or nodules in cat scratch disease, and vasculitis (often associated with endocarditis). In addition, febrile morbilliform rash, purpura, urticaria, erythema nodosum, erythema multiforme, erythema marginatus, granuloma annularis, leukocytoclastic vasculitis, granulomatous reactions, and angioproliferative reactions may occur. Considering the broad spectrum of infection and the potential complications associated with Bartonella spp., the infection should be considered by physicians more frequently among the differential diagnoses of idiopathic conditions. Health professionals and researchers often neglected this diseases.

The seroprevalence of Bartonella spp. in the blood of patients with musculoskeletal complaints and blood donors, Poland: a pilot study

BACKGROUND

Bartonella spp. can cause a variety of diseases, such as lymphadenopathies, cat scratch disease, and trench fever, but can also give rise to many non-specific symptoms. No data exists regarding the prevalence of Bartonella spp. in patients with musculoskeletal complaints, nor among blood donors in Poland.

METHODS

The presence of anti-Bartonella IgM and IgG in the serum of blood donors (n = 65) (Lodz, Poland) and in the patients of the Department of Rheumatology Clinic (n = 40) suffering from musculoskeletal symptoms was tested by immunofluorescence. Blood samples were cultured on enriched media. Epidemiological questionnaires were used to identify key potential risk factors, such as sex, age, contact with companion animals, and bites from insects or animals.

RESULTS

Altogether, 27 of the 105 tested subjects were seropositive for Bartonella henselae IgG (23%) and three for Bartonella quintana IgG (2.85%); IgMs against B. henselae were found in three individuals (2.85%), and IgMs against B. quintana were found in one (1.54%). No statistically significant difference was found between the prevalence of B. henselae in the blood of donors or patients and the presence of unexplained musculoskeletal complaints (23% vs 30%). Individuals who had kept or been scratched by cats were not more likely to be B. henselae seropositive (p > 0.01). Tick bites were more commonly reported in patients, but insignificantly (p > 0.01).

CONCLUSION

This is the first report of a high seroprevalence of anti-Bartonella IgG in patients with musculoskeletal symptoms and in blood donors in Poland. The obtained results indicate that such seroprevalence may have a possible significance in the development of musculoskeletal symptoms, although it should be confirmed on a larger group of patients. Asymptomatic bacteremia might occur and pose a threat to recipients of blood from infected donors. Hence, there is a need for more detailed research, including molecular biology methods, to clarify the potential risk of Bartonella spp. being spread to immunocompromised individuals.

KEY POINTS

• This is the first study presenting high seroprevalence of Bartonella spp. in Poland. • IgG and IgM antibodies against B. quintana were found in blood samples of blood donors.

A review on the occurrence of companion vector-borne diseases in pet animals in Latin America

Companion vector-borne diseases (CVBDs) are an important threat for pet life, but may also have an impact on human health, due to their often zoonotic character. The importance and awareness of CVBDs continuously increased during the last years. However, information on their occurrence is often limited in several parts of the world, which are often especially affected. Latin America (LATAM), a region with large biodiversity, is one of these regions, where information on CVBDs for pet owners, veterinarians, medical doctors and health workers is often obsolete, limited or non-existent. In the present review, a comprehensive literature search for CVBDs in companion animals (dogs and cats) was performed for several countries in Central America (Belize, Caribbean Islands, Costa Rica, Cuba, Dominican Republic, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, Panama, Puerto Rico) as well as in South America (Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, French Guiana, Guyana (British Guyana), Paraguay, Peru, Suriname, Uruguay, Venezuela) regarding the occurrence of the following parasitic and bacterial diseases: babesiosis, heartworm disease, subcutaneous dirofilariosis, hepatozoonosis, leishmaniosis, trypanosomosis, anaplasmosis, bartonellosis, borreliosis, ehrlichiosis, mycoplasmosis and rickettsiosis. An overview on the specific diseases, followed by a short summary on their occurrence per country is given. Additionally, a tabular listing on positive or non-reported occurrence is presented. None of the countries is completely free from CVBDs. The data presented in the review confirm a wide distribution of the CVBDs in focus in LATAM. This wide occurrence and the fact that most of the CVBDs can have a quite severe clinical outcome and their diagnostic as well as therapeutic options in the region are often difficult to access and to afford, demands a strong call for the prevention of pathogen transmission by the use of ectoparasiticidal and anti-feeding products as well as by performing behavioural changes.

Bartonella spp. Bloodstream Infection in a Canadian Family

Historically, Bartonella spp. have been associated with febrile illness (Oroya fever, trench fever, and cat scratch disease), endocarditis (numerous Bartonella spp.), and vasoproliferative lesions (Bartonella bacilliformis, Bartonella quintana, Bartonella henselae, and Bartonella vinsonii subsp. berkhoffii), occurring most often but not exclusively in immunocompromised patients. Recently, bloodstream infections with various Bartonella spp. have been documented in nonimmunocompromised individuals in association with a spectrum of cardiovascular, neurologic, and rheumatologic symptoms. As documented in this family, symptoms for which the medical implications remain unclear can occur in multiple family members infected with one or more Bartonella spp. Serial serologic and molecular microbiological findings supported exposure to or infection with Bartonella spp. in all seven family members. Either antibiotics failed to eliminate bacteremic infection, resulted in partial resolution of symptoms, or potentially reinfection occurred during the 19-month study period. There is a substantial need for clinical research to clarify the extent to which Bartonella spp. bacteremia induces nonspecific cardiovascular, neurologic, or rheumatologic symptoms, for ongoing improvement in the sensitivity and specificity of diagnostic testing, and clarification as to if, when, and how to treat patients with documented Bartonella spp. bacteremia.

Bartonella henselae Infection in Sickle Cell Disease Mice Is Associated with Hyperalgesia

BACKGROUND

Sickle cell disease (SCD) is the most prevalent hematologic genetic disorder. Acute vaso-occlusive painful crisis is the hallmark of the disease and may be related to subclinical infections. Bartonellosis, a rare and neglected infection, is caused by Bartonella spp., which can be found in donated blood. These bacteria cause intraerythrocytic and endothelial infection and pain, all of which occur in SCD. It is likely that this infection is transmitted to SCD patients during transfusion from donated blood, leading to pain. We, therefore, evaluated whether Bartonella henselae infection would cause hyperalgesia in mice with SCD.

MATERIALS AND METHODS

SCD mice were generated by transplantation of nucleated bone marrow cells harvested from transgenic Berkeley sickle mice into 2-month-old irradiated C57BL/6 mice. We infected four SCD mice by intraperitoneal inoculation with B. henselae, and inoculated four other mice with the same volume of saline. Mechanical hyperalgesia was determined using von Frey monofilaments by two blinded observers. Thereafter, the animals were anesthetized and euthanized to collect blood, liver, and spleen samples to seek B. henselae infection by PCR.

FINDINGS

We confirmed the experimental infection in all animals by PCR. Tremors and mechanical hypersensitivity were demonstrated by SCD mice infected with B. henselae infection but not in those receiving saline.

CONCLUSION

B. henselae infection may be related to pain and other symptoms in SCD.

Bartonella quintana and Bartonella vinsonii subsp. vinsonii bloodstream co-infection in a girl from North Carolina, USA

The genus Bartonella consists of globally distributed and highly diverse alpha-proteobacteria that infect a wide-range of mammals. Medically, Bartonella spp. constitute emerging, vector-borne, zoonotic, intravascular organisms that induce long-lasting bacteremia in reservoir-adapted (passive carrier of a microorganism) hosts. At times, these bacteria are accidentally transmitted by animal scratches, bites, needles sticks or vectors to animal or human hosts. We report the first documented human case of blood stream infection with Bartonella vinsonii subsp. vinsonii in a girl from North Carolina, USA, who was co-infected with Bartonella quintana. Limitations of Bartonella spp. serology and the challenges of microbiological culture and molecular diagnostic confirmation of co-infection with more than one Bartonella spp. are discussed. When and where these infections were acquired is unknown; however, exposure to rodents, fleas and cats in the peri-equestrian environment was a suspected source for transmission of both organisms.

Seroprevalence of Bartonella spp., Coxiella burnetii, and Hantavirus among people who inject drugs in Rio de Janeiro, Brazil: a retrospective assessment of a biobank

The increasing use of illicit drugs imposes a public health challenge worldwide. People who inject drugs (PWID) are more susceptible to health complications due to immunosuppression associated with drug use and non-hygienic self-administration of substances, contaminants, and liquids. PWID are subjected to increased risk of acquiring and transmitting different pathogens (frequently functioning as sentinel cases for (re)emerging pathogens), including those transmitted by arthropods and vertebrate reservoirs in unhealthy environments. A clear association between injection drug use and HIV, HBV, and HCV infections has been described; however, other infectious viral and bacterial agents have been seldomly assessed. In this study, we investigated the seroprevalence of Bartonella spp., Coxiella burnetii, and Hantavirus among 300 randomly selected PWIDs from Rio de Janeiro, as part of a multi-city cross-sectional study carried out in the 1990s. Point seroprevalences and respective 95% CIs are as follows: 9.3% for C. burnetii (95% CI: 6.0%-13.0%), 1.0% for Bartonella spp. (95% CI: 0.0%-3.0%), and 4.0% for Hantavirus (95% CI: 2.0%-7.0%). In addition to the blood-borne pathogens, the results of this study increase our knowledge on other transmissible infectious agents in PWID. The high seroprevalence of C. burnetii and Hantavirus found among PWID is intriguing and suggests the need to carry out prospective studies, including molecular analyses, to confirm these findings and allow a better understanding of the putative relevance of these zoonotic infectious agents among PWID.

Improvement of Bartonella henselae DNA Detection in Cat Blood Samples by Combining Molecular and Culture Methods

Bartonella spp. are bacteria of worldwide distribution that cause asymptomatic to fatal infections in animals and humans. The most common zoonotic species is Bartonella henselae, for which cats are the major natural reservoir host. To better understand Bartonella sp. diagnostic limitations, we determined the frequency of bloodstream infection in 112 cats by comparing and combining the results of multiple conventional and nested PCRs from blood and liquid culture samples. Using liquid culture conventional PCR, Bartonella sp. DNA was amplified from 27.7% of samples (31/112) compared to 90.2% of samples (101/112) by combining nested PCR from blood and liquid culture, indicating that PCR testing of more than one type of sample provides better sensitivity than a standalone PCR and that bloodstream infection is very frequent among cats in southeastern Brazil. This study reinforces the need for multistep testing for Bartonella sp. infection to prevent false-negative diagnostic results, even in reservoir hosts such as cats that typically maintain higher bacteremia levels.

Demographic characteristics of teenage boys with horizontal striae distensae of the lower back

BACKGROUND

This study examines the clinical characteristics and demographics of teenage boys with horizontal striae distensae of the lower back in an outpatient setting.

METHODS

Retrospective medical chart reviews and telephone survey studies were completed on an outpatient cohort of 12 boys 11 to 17 years of age with a clinical diagnosis of transverse striae distensae of the lower back at a single-center, university-based, pediatric dermatology practice. We evaluated the clinical features of the striae, participant demographic characteristics, and past medical history. A review of the literature concerning risk factors was conducted using PubMed and Google Scholar.

RESULTS

Of the 14 patients we contacted, 12 agreed to participate. The average age of onset for the striae was 14.3 years. All boys were above the 50th percentile in height at the time of onset. Eight (66.7%) reported a significant growth spurt before the appearance of the stretch marks. Most were asymptomatic. None of the boys had a history of unmonitored exogenous steroid use or prior infection with Bartonella henselae or Borrelia burgdorferi. Only one (8.3%) had a chronic medical condition. Eleven (91.7%) had at least one first-degree relative with striae distensae.

CONCLUSION

Our results indicate that horizontal striae distensae of the lower back in adolescent boys is associated with a rapid growth spurt, tall stature, and family history of striae distensae. There is no association between this type of striae distensae and any chronic medical condition, bacterial infection, or exogenous steroid use. Thus a careful review of systems and counseling without further medical testing is reasonable management.

Bartonella Species, an Emerging Cause of Blood-Culture-Negative Endocarditis

Since the reclassification of the genus Bartonella in 1993, the number of species has grown from 1 to 45 currently designated members. Likewise, the association of different Bartonella species with human disease continues to grow, as does the range of clinical presentations associated with these bacteria. Among these, blood-culture-negative endocarditis stands out as a common, often undiagnosed, clinical presentation of infection with several different Bartonella species. The limitations of laboratory tests resulting in this underdiagnosis of Bartonella endocarditis are discussed. The varied clinical picture of Bartonella infection and a review of clinical aspects of endocarditis caused by Bartonella are presented. We also summarize the current knowledge of the molecular basis of Bartonella pathogenesis, focusing on surface adhesins in the two Bartonella species that most commonly cause endocarditis, B. henselae and B. quintana. We discuss evidence that surface adhesins are important factors for autoaggregation and biofilm formation by Bartonella species. Finally, we propose that biofilm formation is a critical step in the formation of vegetative masses during Bartonella-mediated endocarditis and represents a potential reservoir for persistence by these bacteria.

Chronic lymphadenopathy caused by a Brazilian strain of Bartonella henselae

Bartonella henselae is a relevant causative agent of bartonelloses in humans. We described an immunocompetent patient with clinical manifestation of chronic cervical lymphadenopathy after a cat-scratch in her forearm. This case shows B. henselae infection persistence even after prolonged antibiotic treatment.

Clinical Profile and Visual Outcome of Ocular Bartonellosis in Malaysia

Background. Ocular bartonellosis can present in various ways, with variable visual outcome. There is limited data on ocular bartonellosis in Malaysia. Objective. We aim to describe the clinical presentation and visual outcome of ocular bartonellosis in Malaysia. Materials and Methods. This was a retrospective review of patients treated for ocular bartonellosis in two ophthalmology centers in Malaysia between January 2013 and December 2015. The diagnosis was based on clinical features, supported by a positive Bartonella spp. serology. Results. Of the 19 patients in our series, females were predominant (63.2%). The mean age was 29.3 years. The majority (63.2%) had unilateral involvement. Five patients (26.3%) had a history of contact with cats. Neuroretinitis was the most common presentation (62.5%). Azithromycin was the antibiotic of choice (42.1%). Concurrent systemic corticosteroids were used in approximately 60% of cases. The presenting visual acuity was worse than 6/18 in approximately 60% of eyes; on final review, 76.9% of eyes had a visual acuity better than 6/18. Conclusion. Ocular bartonellosis tends to present with neuroretinitis. Azithromycin is a viable option for treatment. Systemic corticosteroids may be considered in those with poor visual acuity on presentation.

Detection of Mycoplasma haemocanis, Mycoplasma haematoparvum, Mycoplasma suis and other vector-borne pathogens in dogs from Córdoba and Santa Fé, Argentina

Background

In Argentina, only very few reports are available for canine tick-borne diseases where most are related to parasitic diseases. The objective of this survey was to investigate the prevalence of tick-borne pathogens in 70 dogs from Santa Fé and Córdoba, Argentina.

Methods

Microscopic blood smear examination as well as polymerase chain reaction (PCR) amplification using species-specific markers of Anaplasma, Babesia, Bartonella, Borrelia, Ehrlichia, Francisella, Mycoplasma (hemotropic group) and Rickettsia, followed by DNA sequencing were used to establish the prevalence of each infecting pathogen.

Results

Blood smear analysis showed 81% (57/70) prevalence of structures morphologically compatible with hemotropic mycoplasmas. No structures resembling either piroplasms or Anaplasma/Ehrlichia were detected. Hemotropic mycoplasma species (Mycoplasma haematoparvum, Mycoplasma haemocanis and Mycoplasma suis) were the most prevalent pathogens detected with an overall prevalence of 77.1%. Anaplasma platys was detected and identified in 11 of the 70 dogs (15.7%), meanwhile two Bartonella spp. (B. clarridgeiae and an uncharacterized Bartonella sp.) and Babesia vogeli were detected at 3 and 7% prevalence, respectively.

Conclusions

The work presented here describes a high molecular prevalence for hemotropic mycoplasma species in each of the five locations selected. Three Mycoplasma spp., including Mycoplasma suis, reported for the first time in dogs have been identified by DNA amplification and sequencing. This study highlights the risk that these bacterial pathogens represent for companion animals and, due to their potential zoonotic nature, also for people.

Bartonella spp. - a chance to establish One Health concepts in veterinary and human medicine

Infectious diseases remain a remarkable health threat for humans and animals. In the past, the epidemiology, etiology and pathology of infectious agents affecting humans and animals have mostly been investigated in separate studies. However, it is evident, that combined approaches are needed to understand geographical distribution, transmission and infection biology of “zoonotic agents”. The genus Bartonella represents a congenial example of the synergistic benefits that can arise from such combined approaches: Bartonella spp. infect a broad variety of animals, are linked with a constantly increasing number of human diseases and are transmitted via arthropod vectors. As a result, the genus Bartonella is predestined to play a pivotal role in establishing a One Health concept combining veterinary and human medicine.