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

Okaro U1, Addisu A2, Casanas B2, Anderson B3. Clin Microbiol Rev. 2017.

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.  Seroprevalence of Bartonella species, Coxiella burnetii and Toxoplasma gondii among patients with hematological malignancies: A pilot study in Romania.

Messinger CJ1, Gurzau ES2,3, Breitschwerdt EB4,5, Tomuleasa CI6,7, Trufan SJ8, Flonta MM9, Maggi RG4,5, Berindan-Neagoe I6,10,11, Rabinowitz PM8. Zoonoses Public Health. 2017.

Patients receiving immunosuppressive cancer treatments in settings where there is a high degree of human-animal interaction may be at increased risk for opportunistic zoonotic infections or reactivation of latent infections. We sought to determine the seroprevalence of selected zoonotic pathogens among patients diagnosed with haematologic malignancies and undergoing chemotherapeutic treatments in Romania, where much of the general population lives and/or works in contact with livestock. A convenience sample of 51 patients with haematologic cancer undergoing chemotherapy at a referral clinic in Cluj-Napoca, Romania, was surveyed regarding animal exposures. Blood samples were obtained and tested for evidence of infection with Bartonella species, Coxiella burnetii and Toxoplasma gondii, which are important opportunistic zoonotic agents in immunocompromised individuals. 58.8% of participants reported living or working on a farm, and living or working on a farm was associated with contact with livestock and other animals. 37.5% of participants were IgG seroreactive against one or more of five Bartonella antigens, and seroreactivity was statistically associated with living on farms. Farm dwellers were 3.6 times more likely to test IgG seroreactive to Bartonella antibodies than non-farm dwellers. 47.1% of the participants tested T. gondii IgG positive and 13.7% tested C. burnetii IgG positive, indicating past or latent infection. C. burnetii IgM antibodies were detected in four participants (7.8%), indicating possible recent infection. These results indicate that a large proportion of patients with haematologic cancer in Romania may be at risk for zoonotic infections or for reactivation of latent zoonotic infections, particularly with respect to Bartonella species. Special attention should be paid to cancer patients’ exposure to livestock and companion animals in areas where much of the population lives in rural settings.  Seroprevalence of Bartonella Species in Patients with Ocular Inflammation.

Brydak-Godowska J1, Kopacz D1, Borkowski PK2, Fiecek B3, Hevelke A4, Rabczenko D5, Tylewska-Wierzbanowska S3, Kęcik D1, Chmielewski T3. Adv Exp Med Biol. 2017.

Bartonella species, vector-borne etiologic agents of many systemic or self-limited infections, are responsible for a widening spectrum of diseases in humans, including inflammatory conditions of the eye. The aim of this study was to determine whether there is any relationship between uveitis and the evidence of Bartonella spp. infection in the serum, ocular fluid, and cataract mass in patients with intraocular inflammation. Polymerase chain reaction (PCR)-based tests and DNA sequencing were performed on surgery-extracted specimens of intraocular fluid and lens mass of 33 patients. Sera from 51 patients and 101 control subjects were tested for the presence of specific antibodies against Bartonella spp. Neither IgM-class antibodies against Bartonella spp. nor Bartonella spp. DNA were detected. A specific IgG-class antibody was found in 33.3% of the patients with uveitis. The rate of positive Bartonella serology was higher among the uveitis patients than that in control subjects. This high rate may in part result from unrecognized indirect mechanisms rather than the immediate presence and multiplication of Bartonella spp. in the eyeball. Nonetheless we believe that screening for Bartonella spp. should become part of the diagnostic workup in uveitis.

Another ocular study: