Detection of Bartonella sp. and a novel spotted fever group Rickettsia sp. in Neotropical fleas of wild rodents (Cricetidae) from Southern Brazil

The Neotropical region shows a great diversity of fleas, comprising more than 50 genera. The importance of the study of fleas is linked to their potential role as disease vectors. The aim of this study is to investigate the presence of Rickettsia spp. and Bartonella spp. in Neotropical fleas collected from wild rodents in Southern Brazil. From 350 rodents captured, 30 were parasitized by fleas. A total of 61 fleas belonging to two genera and six different species were collected (Craneopsylla minerva minerva, Polygenis occidentalis occidentalis, Polygenis platensis, Polygenis pradoi, Polygenis rimatus, and Polygenis roberti roberti). In 13 % of fleas of three different species (C. minerva, P. platensis, and P. pradoi) Rickettsia sp. DNA was found. Phylogenetic analysis of concatenated sequences of gltA, htrA, and ompA genes showed that Rickettsia sp. found in rodent fleas (referred as strain Taim) grouped together with Spotted Fever Group Rickettsia. In reference to Bartonella spp., five genotypes were identified in seven fleas of two species (C. minerva and P. platensis) and in five rodent spleens. Also, 207 frozen samples of wild rodents were screened for these pathogens: while none was positive for Rickettsia spp.; five rodent spleens were PCR-positive for Bartonella spp.. Herein, we show the detection of potential novel variants of Bartonella sp. and Rickettsia sp. in fleas collected of wild rodents from Southern Brazil. Further studies are needed to fully characterize these microorganisms, as well as to improve the knowledge on the potential role of Neotropical flea species as diseases vectors.     

Infectious diseases of dogs and cats on Isabela Island, Galapagos

BACKGROUND: Vaccination and importation of dogs and cats are prohibited in the Galapagos, resulting in a uniquely isolated population. The purpose of this study was to determine the prevalence of infectious diseases of dogs and cats that impact their health, could spill over to native wildlife, or sentinel diseases of concern to humans. HYPOTHESIS: The isolation of dogs and cats in the Galapagos protects them from diseases common in mainland populations. ANIMALS: Ninety-five dogs and 52 cats presented during a neutering campaign. METHODS: A prospective cross-sectional study was performed. Blood was collected for serological and DNA evaluation of a panel of infectious diseases. RESULTS: Antibodies against parvovirus (100%), parainfluenza virus (100%), adenovirus 1/2 (66-67%), and distemper virus (22%) were present in dogs. Dirofilaria immitis was also common in dogs (34%), with lower prevalences of Wolbachia pipiens (22%), Bartonella sp. (13%), Ehrlichia/Anaplasma spp. (1%), and Mycoplasma haemocanis (1%) observed. Antibodies against panleukopenia virus (67%), Toxoplasma gondii (63%), calicivirus (44%), and herpesvirus 1 (10%) were detected in cats. Feline leukemia virus antigen, feline immunodeficiency virus antibody, or coronavirus antibodies were not detected. Bartonella sp. (44%) infections were common in cats, but only one was infected with M. haemofelis. CONCLUSIONS AND CLINICAL IMPORTANCE: Despite their relative seclusion from the rest of the world, cats and dogs of Isabela were exposed to many pathogens found in mainland South America. Parasite prophylaxis, neutering, and strict enforcement of animal movement restrictions would control a majority of the diseases. In the absence of vaccination, a reservoir of susceptible animals remains vulnerable to new disease introductions.     

Bartonella species antibodies and hyperglobulinemia in privately owned cats

Background

Bartonella species are zoonotic agents and primary pathogens in cats. Hyperglobulinemia has been associated with bartonellosis in humans and cats.

Hypothesis/Objectives

To evaluate for associations between Bartonella species immunoglobulin G (IgG) antibodies and serum biochemistry panel results in privately owned cats.

Animals

1,477 privately owned cats.

Methods

Residual sera were collected after biochemical evaluation for this prospective, cross‐sectional serosurvey. Bartonella species IgG ELISA was performed with a cutoff value of ≥1 : 64. Stepwise logistic regression analysis was performed with the endpoint titer as the outcome variable. The final statistical model included age, albumin, ALP activity, ALT activity, bilirubin, creatinine, glucose, and globulin as covariates. Serum protein electrophoresis was performed with serum from 50 cats with and without antibodies to Bartonella species and hyperglobulinemia. Sera from cats seropositive to Bartonella species and with hyperglobulinemia were assessed for evidence of exposure to other infectious agents associated with hyperglobulinemia.

Results

Risk of seropositivity to Bartonella species was positively associated with the natural log of globulin concentration (OR = 11.90, 95% CI 6.15–23.02, P < .0001), and inversely associated with the natural log of glucose concentration (OR = 0.66, 95% CI 0.50–0.87, P = .004). Another explanation for hyperglobulinemia was not identified for most cats with Bartonella species antibodies. Hyperglobulinemia was primarily caused by polyclonal gammopathy in cats that were seronegative and seropositive for Bartonella species.

Conclusions and Clinical Importance

Hyperglobulinemia was significantly associated with seropositivity to Bartonella species. Testing for bartonellosis is warranted in cats with unexplained hyperglobulinemia and clinical or laboratory findings suggestive of bartonellosis.     

Genetic diversity and hematological and biochemical alterations in Alouatta primates naturally infected with hemoplasmas in Brazil

Mycoplasma spp. and Bartonella spp. are Gram-negative bacteria transmitted by arthropod vectors that infect red blood cells of several mammal species. This study investigated the occurrence and genetic diversity of hemoplasmas and Bartonella spp. in 68 howler monkeys kept in captivity in São Paulo, a southeastern state in Brazil. In addition, possible hematological, biochemical and electrophoretic changes of serum proteins associated with the occurrence of hemoplasmas and Bartonella spp. in captive primates were also investigated. The cPCR results showed that all sampled howler monkeys were negative for Bartonella spp. based on the gltA gene. The cPCR results indicated that 18 (26.47%) non-human primates (NHP) were positive for hemoplasmas based on the 16S rRNA gene. Monocyte and lymphocyte counts were higher in hemoplasma-positive howlers (P < 0.05). Platelet counts decreased in nonhuman primates (NHP) positive for hemoplasmas (P < 0.05). The results from the blood serum proteinogram and biochemistry analyses were not significantly different between NHPs positive and negative for hemotrophic mycoplasmas. Phylogenetic analysis using Bayesian Inference (BI) based on the 16S rRNA gene positioned the obtained sequences close to ‘Candidatus Mycoplasma kahanei’. The analysis of sequence diversity of the 16S rRNA gene showed that 5 different genotypes are circulating in NHP in Brazil and in the world; besides, a clear separation between the sequences of hemoplasmas that infect NHP of the Sapajus and Alouatta genus in Brazil was found, probably corresponding to two different species. The pathogenic potential of this hemoplasma species in NHP should be further investigated.     

Detection of Bartonella henselae in the blood of 2 adult horses

BACKGROUND: Bartonella spp. are emerging zoonotic agents that have been found in a wide variety of domestic animals and wildlife and cause a number of clinical syndromes. Bartonella sp. infection has been identified in a growing number of animal species, including cats, rodents, porpoises, and canids, but has not been reported in horses. OBJECTIVE: To document the presence of Bartonella sp. in the blood of horses. ANIMALS: One horse with chronic arthropathy and 1 horse with presumptive vasculitis. METHODS: Blood samples were tested for the presence of Bartonella sp. by a combination of multiplex real-time polymerase chain reaction and enrichment culture technique. RESULTS: Bartonella henselae was isolated or detected in the blood of both horses. CONCLUSION AND CLINICAL IMPORTANCE: Bartonella henselae infection should be investigated as the cause of disease in horses.