Dilated cardiomyopathy of possible dietary origin in a cat

An 11-year-old spayed female domestic shorthaired cat was diagnosed with severe dilated cardiomyopathy (DCM) and congestive heart failure. The cat had been eating cat foods that were high in pulses (e.g. peas, lentils, chickpeas). Neither plasma nor whole blood taurine concentrations were deficient. Primary treatment included furosemide, pimobendan, and clopidogrel, and changing to diets that did not contain pulses (a taurine supplements was not administered). The cat's clinical signs improved, high-sensitivity cardiac troponin I concentrations decreased, and echocardiographic measurements stayed relatively stable for over one year after initiating cardiac medications and changing the diet. Ultimately, the cat was euthanized for worsening congestive heart failure 374 days after the diagnosis of DCM. Infectious disease testing during the time of clinical surveillance was negative. Routine histopathology of the heart was unremarkable, but electron microscopy of the left ventricle showed large numbers of mitochondria of variable size and structure. A moderate number of lamellar bodies and autophagic vacuoles also were noted. This case report illustrates an unusual case of a cat with DCM unrelated to taurine deficiency. The relative roles of diet change, cardiac medications, and a dedicated owner are unclear, but this cat's relatively long survival time is similar to that seen after diet change in dogs and cats with DCM eating high-pulse diets.

Distribution and risk factors of canine haemotropic mycoplasmas in hunting dogs from southern Italy

Mycoplasma haemocanis (Mhc) and "Candidatus Mycoplasma haematoparvum" (CMhp) are the main haemoplasma species known to infect dogs. The aim of this study was to determine the prevalence of haemoplasma species infections in hunting dogs from southern Italy and assess related risk factors. 1,433 hunting dogs living in Campania region were tested by qPCR assay. The prevalence was 19.9 %; 13.1 % for Mhc and 11.4 % for CMhp; 4.6 % showed a coinfection with both haemoplasma species. Statistical analysis revealed living in Salerno province (Mhc: OR 3.72; CMhp: OR 2.74), hound (Mhc: OR 5.26; CMhp: OR 8.46) and mixed breed (Mhc: OR 3.38; CMhp: OR 2.80), rural environment (Mhc: OR 12.58; CMhp: OR 10.38), wild mammal hunting (Mhc: OR 8.73; CMhp: OR 8.32), cohabitation with other animals (Mhc: OR 2.82; CMhp: OR 2.78) and large pack size (Mhc: OR 2.96; CMhp: OR 1.61) as risk factors for haemoplasmas. Male gender (OR 1.44) and tick infestation history (OR 1.40) represented risk factors only for Mhc, while adult age (2-7 years - OR 2.01; > 7 years - OR 1.84) and large body size (OR 1.48) were associated only to CMhp. Mhc infection was significantly associated to Babesia vogeli (p < 0.05) and Hepatozoon canis (p < 0.001), while CMhp with H. canis (p < 0.001). This study adds information on haemoplasma species distribution in hunting dogs in southern Italy. Outdoor lifestyle and contact with wild fauna, through greater exposure to tick infestation, or possibly wounds acquired during hunting or fighting, could be factors contributing to haemoplasma infections.

Hepatozoon canis in hunting dogs from Southern Italy: distribution and risk factors

Hepatozoon canis is a hemoprotozoan organism that infects domestic and wild carnivores throughout much of Europe. The parasite is mainly transmitted through the ingestion of infected ticks containing mature oocysts. The aims of the present survey were to determine the prevalence of H. canis in hunting dogs living in Southern Italy and to assess potential infection risk factors. DNA extracted from whole blood samples, collected from 1433 apparently healthy dogs living in the Napoli, Avellino, and Salerno provinces of Campania region (Southern Italy), was tested by a quantitative real-time polymerase chain reaction (qPCR) assay to amplify H. canis. Furthermore, the investigated dog population was also screened by qPCR for the presence of Ehrlichia canis, a major tick-borne pathogen in Southern Italy, in order to assess possible co-infections. Two hundred dogs were H. canis PCR-positive, resulting in an overall prevalence of 14.0% (CI 12.2–15.9). Breed category (P < 0.0001), hair coat length (P = 0.015), and province of residence (P < 0.0001) represented significant risk factors for H. canis infection. The presence of H. canis DNA was also significantly associated with E. canis PCR positivity (P < 0.0001). Hunting dogs in Campania region (Southern Italy) are frequently exposed to H. canis, and the infection is potentially associated with close contact with wildlife. Further studies are needed to assess the pathogenic potential of H. canis, as well as the epidemiological relationships between hunting dogs and wild animal populations sharing the same habitats in Southern Italy.

Bartonella spp. as a Possible Cause or Cofactor of Feline Endomyocarditis-Left Ventricular Endocardial Fibrosis Complex

Endomyocarditis is a commonly detected post-mortem finding in domestic cats presenting for sudden onset cardiovascular death, yet the aetiology remains unresolved. Cats are documented reservoir hosts for Bartonella henselae, the infectious cause of cat scratch disease in man. Various Bartonella spp. have been associated with culture-negative endocarditis, myocarditis and sudden death in man and animals. We hypothesized that Bartonella spp. DNA could be amplified more often from the hearts of cats with feline endomyocarditis-left ventricular endocardial fibrosis (FEMC-LVEF) complex compared with cats with hypertrophic cardiomyopathy (HCM) or cats with grossly and microscopically unremarkable hearts (designated non-cardiac disease controls). Formalin-fixed and paraffin wax-embedded, cardiac tissues from 60 domestic and purebred cats aged 3 months to 18 years were examined, and histological features were recorded. Cardiac tissue sections were tested for Bartonella DNA using multiple 16-23S intergenic transcribed spacer region polymerase chain reaction (PCR) primer sets, including two Bartonella genera, a Bartonella koehlerae species-specific and a Bartonella vinsonii subsp. berkhoffii-specific assay, followed by DNA sequence confirmation of the species or genotype. Special precautions were taken to avoid DNA cross-contamination between tissues. Bartonella spp. DNA was amplified by PCR and sequenced from 18 of 36 cats (50%) with FEMC-LVEF and 1/12 (8.3%) cats with HCM. Bartonella spp. DNA was not amplified from any non-cardiac disease control hearts. Based on PCR/DNA sequencing, one Bartonella spp. was amplified from 10 cats, while the remaining eight were coinfected with more than one Bartonella spp. To our knowledge, this study represents the first documentation of B. vinsonii subsp. berkhoffii genotype I infection in cats (n = 11). Fluorescence in-situ hybridization testing facilitated visualization of Bartonella bacteria within the myocardium of four of seven PCR-positive FEMC-LVEF hearts. Collectively, these findings support the hypothesis that Bartonella spp. may play a primary role or act as a cofactor in the pathogenesis of FEMC-LVEF. Studies involving cats from other geographical regions and definitive demonstration of Bartonella spp. within regions of inflammation are needed to confirm an association between Bartonella spp. and FEMC-LVEF induced morbidity and mortality in cats.

Doxycycline treatment efficacy in dogs with naturally occurring Anaplasma phagocytophilum infection

OBJECTIVES

To evaluate doxycycline treatment efficacy and post-treatment pathogen persistence in dogs naturally infected with Anaplasma phagocytophilum in endemic regions of the USA.

MATERIALS AND METHODS

Symptomatic dogs in four US states (MN, WI, CT and CA) were evaluated before treatment with doxycycline and approximately 30 and 60 days post-treatment. Clinicopathological parameters, co-exposures and A. phagocytophilum DNA in whole blood and lymph node samples were compared between A. phagocytophilum infected and uninfected dogs.

RESULTS

In total, 42 dogs fulfilled the inclusion criteria, with 16 dogs (38%) blood PCR-positive and 26 dogs (62%) blood PCR-negative for A. phagocytophilum. At initial evaluation, the proportion of clinicopathological abnormalities was similar between A. phagocytophilum infected and uninfected dogs, although thrombocytopenia and lymphopenia were statistically more prevalent among A. phagocytophilum infected dogs. Treatment with doxycycline resulted in resolution of all clinical abnormalities in infected dogs; four dogs had persistent haematological abnormalities, including mild leukopenia, eosinopenia and lymphopenia. All 16 infected dogs became blood PCR-negative approximately 30 and 60 days after treatment onset. Additionally, 13/13 (100%) lymph node specimens tested post-treatment were PCR-negative. Select clinicopathological abnormalities persisted in uninfected dogs after treatment.

CLINICAL SIGNIFICANCE

The results of this study support the efficacy of doxycycline therapy for clinical treatment of dogs naturally infected with A. phagocytophilum in the USA. This study did not find clinical, haematological or microbiological indicators that supported the persistence of A. phagocytophilum infection in naturally infected dogs following treatment with doxycycline for 28 days.

Prevalence of Vector-Borne Pathogens in Southern California Dogs With Clinical and Laboratory Abnormalities Consistent With Immune-Mediated Disease

BACKGROUND

Studies investigating the prevalence of vector-borne pathogens in southern California dogs are limited. Occult infections might be misdiagnosed as idiopathic immune-mediated disease.

HYPOTHESIS/OBJECTIVES

(1) To determine the prevalence of vector-borne pathogens in southern California dogs with compatible clinical findings using PCR and serologic panels and (2) to determine whether testing convalescent samples and repeating PCR on acute samples using the same and different gene targets enhance detection.

ANIMALS

Forty-two client-owned dogs with clinical signs of vector-borne disease presenting to specialty practices in San Diego County.

METHODS

Combined prospective and retrospective observational study. Forty-two acute and 27 convalescent samples were collected. Acute samples were prospectively tested for antibodies to Rickettsia, Ehrlichia, Bartonella, Babesia, Borrelia, and Anaplasma species. PCR targeting Ehrlichia, Babesia, Anaplasma, hemotropic Mycoplasma, and Bartonella species was also performed. Retrospectively, convalescent samples were tested for the same organisms using serology, and for Ehrlichia, Babesia, Anaplasma, and Bartonella species using PCR. Acute samples were retested using PCR targeting Ehrlichia and Babesia species.

RESULTS

Evidence of exposure to or infection with a vector-borne pathogen was detected in 33% (14/42) of dogs. Ehrlichia and Babesia species were most common; each was identified in 5 dogs. Convalescent serologic testing, repeating PCR, and using novel PCR gene targets increased detection by 30%.

CONCLUSIONS AND CLINICAL IMPORTANCE

Repeated testing using serology and PCR enhances detection of infection by vector-borne pathogens in dogs with clinical signs of immune-mediated disease. Larger prevalence studies of emerging vector-borne pathogens in southern California dogs are warranted.

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

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.

Relationship between degenerative joint disease, pain, and Bartonella spp. seroreactivity in domesticated cats

Background

Recently, a potential association was identified between Bartonella exposure and arthritides in mammalian species other than cats.

Hypothesis/Objectives

We hypothesized that Bartonella exposure is associated with more severe degenerative joint disease (DJD) and a greater burden of DJD‐associated pain in client‐owned cats.

Animals

Ninety‐four client‐owned cats (6 months to 20 years old), ranging from clinically unaffected to severely lame because of DJD.

Methods

Using physical examination and radiography, pain and radiographic scores were assigned to each part of the bony skeleton. Sera were tested for Bartonella henselae, B. koehlerae, and B. vinsonii subsp. berkhoffii (genotypes I, II, and III) antibodies using immunofluorescence antibody assays. Variables were categorized and logistic regression used to explore associations.

Results

Seropositivity to Bartonella was identified in 33 (35.1%) cats. After multivariate analysis controlling for age, total DJD score (OR, 0.51; 95% CI, 0.26–0.97; P = .042), appendicular pain score (OR, 0.33; 95% CI, 0.17–0.65; P = .0011), and total pain score (OR, 0.35; 95% CI, 0.17–0.72; P = .0045) were significantly inversely associated with Bartonella seroreactivity status, indicating that cats with higher DJD and pain scores were less likely to be Bartonella seropositive.

Conclusions and Clinical Importance

Based upon this preliminary study, Bartonella spp. seropositivity was associated with decreased severity of DJD and decreased DJD‐associated pain in cats. Additional studies are needed to verify these findings, and if verified, to explore potential mechanisms.

Analysis of seroreactivity against cell culture-derived Bartonella spp. antigens in dogs

BACKGROUND

Little is known about the specificity of Bartonella spp. immunofluorescent antibody (IFA) assays in dogs. Bacteremia in sick dogs most often has been associated with Bartonella henselae (Bh), Bartonella vinsonii subspecies berkhoffii (Bvb), and Bartonella koehlerae (Bk). Clarification of the diagnostic utility of IFA serology when testing against these organisms is needed.

OBJECTIVE

To evaluate the specificity of Bartonella IFA assays utilizing 6 cell culture-grown antigen preparations.

ANIMALS

Archived sera from SPF dogs (n = 29) and from dogs experimentally infected with Bvb (n = 10) and Bh (n = 3).

METHODS

Antibodies (Abs) to Bvb genotypes I, II, and III, Bh serotype I, strains H-1 and SA2, and to Bk were determined by IFA testing.

RESULTS

Serum from naïve SPF dogs shown to be negative for Bartonella bacteremia did not react with any of the 6 Bartonella antigens by IFA testing. Dogs experimentally infected with Bvb genotype I developed Abs against homologous antigens, with no cross-reactivity to heterologous Bvb genotypes, Bh H-1, SA2 strains, or to Bk. Dogs experimentally infected with Bh serotype I developed Abs against Bh H-1, but not to Bh SA2 strain with no cross-reactive Abs to Bvb genotypes I-III or to Bk.

CONCLUSIONS AND CLINICAL IMPORTANCE

Bartonella spp. Ab responses during acute experimental infections are species and type specific.

Flea species infesting dogs in Florida and Bartonella spp. prevalence rates

Several Bartonella spp. associated with fleas can induce a variety of clinical syndromes in both dogs and humans. However, few studies have investigated the prevalence of Bartonella in the blood of dogs and their fleas. The objectives of this study were to determine the genera of fleas infesting shelter dogs in Florida, the prevalence of Bartonella spp. within the fleas, and the prevalence of Bartonella spp. within the blood of healthy dogs from which the fleas were collected. Fleas, serum, and EDTA-anti-coagulated whole blood were collected from 80 healthy dogs, and total DNA was extracted for PCR amplification of Bartonella spp. The genera of fleas infesting 43 of the dogs were determined phenotypically. PCR amplicons from blood and flea pools were sequenced to confirm the Bartonella species. Amplicons for which sequencing revealed homology to Bartonella vinsonii subsp. berkhoffii (Bvb) underwent specific genotyping by targeting the 16S-23S intergenic spacer region. A total of 220 fleas were collected from 80 dogs and pooled by genus (43 dogs) and flea species. Bartonella spp. DNA was amplified from 14 of 80 dog blood samples (17.5%) and from 9 of 80 pooled fleas (11.3%). B. vinsonii subsp. berkhoffii DNA was amplified from nine dogs and five of the flea pools. Bartonella rochalimae (Br) DNA was amplified from six dogs and two flea pools. One of 14 dogs was co-infected with Bvb and Br. The dog was infested with Pulex spp. fleas containing Br DNA and a single Ctenocephalides felis flea. Of the Bvb bacteremic dogs, five and four were infected with genotypes II and I, respectively. Of the Bvb PCR positive flea pools, three were Bvb genotype II and two were Bvb genotype I. Amplification of Bvb DNA from Pulex spp. collected from domestic dogs, suggests that Pulex fleas may be a vector for dogs and a source for zoonotic transfer of this pathogen from dogs to people. The findings of this study provide evidence to support the hypothesis that flea-infested dogs may be a reservoir host for Bvb and Br and that ectoparasite control is an important component of shelter intake protocols.

Phylogenetic diversity of bacteria isolated from sick dogs using the BAPGM enrichment culture platform

BACKGROUND

Bartonella alpha-Proteobacteria growth medium (BAPGM) enrichment culture has proven useful for documenting Bartonella species infection and has facilitated growth of other fastidious bacteria from human samples.

PURPOSE

To report non-Bartonella bacterial isolates obtained from canine samples cultured using BAPGM enrichment culture.

ANIMALS

Between 2004 and 2008, 695 specimens from 513 dogs were tested by the NCSU-IPRL using the BAPGM enrichment culture. Over the same period of time, blood samples from 270 dogs were cultured by the NCSU-CML using Bactec-Plus Aerobic/F media.

METHODS

BAPGM isolates were characterized using Bartonella genus primers and 16S rDNA primers followed by DNA sequencing. NCSU medical records were retrospectively reviewed. Blood culture results from the NCSU-CML were compared with BAPGM blood culture results.

RESULTS

Seventy-nine non-Bartonella isolates were obtained from 69/513 dogs. The most commonly isolated phylum was Proteobacteria (48.1%) with alpha-Proteobacteria being the most commonly isolated class. Staphylococcus and Sphingomonas were the most commonly isolated genera. The majority of the remaining isolates were bacteria that are rarely isolated from canine samples. Comparison of NCSU-CML and IPRL (BAPGM) blood culture isolates showed alpha-Proteobacteria were isolated more often from BAPGM.

CONCLUSIONS AND CLINICAL IMPORTANCE

Use of insect cell culture enrichment medium, such as BAPGM, appears to enhance the growth of alpha-Proteobacteria, but also results in isolation of non-alpha-Proteobacteria from sick dogs. Future studies are needed to elucidate the utility of BAPGM and other "nonconventional" growth media and methods for isolation of fastidious organisms and to determine if these organisms play a causal role in disease development.

Koch's postulates and the pathogenesis of comparative infectious disease causation associated with Bartonella species

In his homage to Lucretius (‘Georgica’), Vergil is credited with stating: ‘Felix qui potuit rerum cognoscere causas’ (‘Fortunate is he who knows the causes of things’). Based on numerous commentaries and publications it is obvious that clinicians, diagnosticians and biomedical research scientists continue to struggle with disease causation, particularly in the assessment of the pathogenic role of ‘stealth pathogens’ that produce persistent infections in the host. Bartonella species, because of their evolutionary ability to induce persistent intravascular infections, present substantial challenges for researchers attempting to clarify the ability of these stealth bacteria to cause disease. By studying the comparative biological and pathological behaviour of microbes across mammalian genera, researchers might be able more rapidly to advance medical science and, subsequently, patient care by undertaking focused research efforts involving a single mammalian species or by attempting to recapitulate a complex disease in an rodent model. Therefore, in an effort to further assist in the establishment of disease causation by stealth pathogens, we use recent research observations involving the genus Bartonella to propose an additional postulate of comparative infectious disease causation to Koch's postulates.

Abstract P3-10-03: Bartonella henselae Infection Detected in Patients with Inflammatory Breast Cancer

Inflammatory breast cancer (IBC) is a very aggressive type of advanced breast cancer with a poor prognosis. Clinical symptoms involve a rapid onset of changes in the skin overlying the breast, including edema, redness and swelling including a wrinkled and orange peel appearance in the skin. This particular presentation is due to the invasion of the skin dermal lymphatics by breast cancer cells that obstructed the lymph channels producing the characteristic skin changes that mimic an inflammatory process. Mouse Mammary Tumor-associated Virus (MMTV) and other infectious agents have been consider as possible etiological agents of IBC particularly related to the initial description of higher incidence in women living in rural areas in North Africa. Although, the etiopathological role of bacteria in this disease has never been explored in spite of the evidence that chronic infections with certain bacteria can facilitate tumors development.

Several bacterial infections promote cell proliferation and could increase the rate of cell transformation. Bartonella spp. is an emerging pathogen that can cause conditions which are characterized by the development of proliferative lesions. Bartonella might cause vasculoproliferative disorders by triggering the proliferation of endothelial cells and inducing the secretion of proliferative cytokines from infected host cells. It cause persistent infection of erythrocytes and endothelial cells in their mammalian hosts and their transmission occur mainly by blood-sucking arthropods. Bartonella are Gram-negative bacteria usually associated with cat-scratch disease, urban trench fever, bacillary angiomatosis-peliosis and endocarditis. Some reports have showed some similarities between cat scratch disease and inflammatory breast cancer (Povoski et al., Breast J 9: 497–500, 2003).

Methods and Results: In the present work, we report the identification of Bartonella henselae in the pleural effusions of two patients with IBC. These patients had both estrogen-receptor negative (ER−) and progesterone-receptor negative (PR−) disease and have failed a number of previous chemotherapy regimens. Furthermore, they had metastatic disease to the pleura, skin, lymph nodes and lung. Cells from the pleural fluids of these patients stained positive for Bartonella sp. using the Warthin-Starry staining kit. Moreover, we used PCR and sequencing of the 16S–23S intergenic spacer (ITS) region to identify the etiological agent as Bartonella henselae. By immunofluorescence using an antibody that specifically recognized Bartonella henselae, the bacteria were found in the nucleus of IBC tumor cells confirming the infection and their intracellular localization.

Conclusions: These results suggested that bacteria infections such as the one produced by Bartonella henselae might contribute to the clinical and pathological characteristics of IBC, associated with rapid spread of the breast tumor cells through the lymphatic system. The infection and activation of endothelial lymphatics by Bartonella might contribute to the highly metastatic process observed in IBC patients. An acute inflammatory reaction triggered by the Bartonella infected endothelium may be crucial for initiating the chronic inflammation in IBC patients and the rapid spread of tumor cells.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-10-03.

Experimental infection of horses with Bartonella henselae and Bartonella bovis

BACKGROUND

Experimental infection of horses with Bartonella species is not documented.

OBJECTIVES

Determine clinical signs, hematologic changes, duration of bacteremia, and pattern of seroconversion in Bartonella henselae or Bartonella bovis-inoculated horses.

ANIMALS

Twelve (2 groups of 6) randomly selected healthy adult horses seronegative and culture negative for Bartonella spp.

METHODS

Experimental/observational study: Group I: B. henselae or saline control was inoculated intradermally into 4 naïve and 2 sentinel horses, respectively. Group II: same design was followed by means of B. bovis. Daily physical examinations, once weekly CBC, immunofluorescent antibody assay serology, real-time polymerase chain reaction (PCR), and twice weekly blood cultures were performed for 6 weeks and at postinoculation day 80 and 139. Bartonella alpha-Proteobacteria growth medium (BAPGM) enrichment blood culture was performed for horses that seroconverted to B. henselae antigens.

RESULTS

Transient clinical signs consistent with bartonellosis occurred in some Bartonella-inoculated horses, but hematological alterations did not occur. Three B. henselae-inoculated horses seroconverted, whereas 1 B. bovis-inoculated horse was weakly seropositive. In Group I, B. henselae was amplified and sequenced from BAPGM blood culture as well as a subculture isolate from 1 horse, blood from a 2nd horse, and BAPGM blood culture from a 3rd horse although a subculture isolate was not obtained. All sentinels remained PCR, culture, and serology negative.

CONCLUSIONS

Detection of Bartonella sp. in blood after experimental inoculation supports bacteremia and seroconversion. Culture with BAPGM may be required to detect Bartonella sp. Although mild clinical signs followed acute infection, no long-term effects were noted for 2 years postinoculation.

Seroprevalence of Ehrlichia canis, Ehrlichia chaffeensis and Ehrlichia ewingii in dogs in North America

BACKGROUND

This study evaluated the exposure of dogs to three different Ehrlichia spp. in the south and central regions of the United States where vector-borne disease prevalence has been previously difficult to ascertain, particularly beyond the metropolitan areas.

METHODS

Dog blood samples (n = 8,662) were submitted from 14 veterinary colleges, 6 private veterinary practices and 4 diagnostic laboratories across this region. Samples were tested for E. canis, E. chaffeensis and E. ewingii specific antibodies using peptide microtiter ELISAs.

RESULTS

Overall, E. canis, E. chaffeensis and E. ewingii seroprevalence was 0.8%, 2.8%, and 5.1%, respectively. The highest E. canis seroprevalence (2.3%) was found in a region encompassing Arkansas, Louisiana, Oklahoma, Tennessee and Texas. E. chaffeensis seroreactivity was 6.6% in the central region (Arkansas, Kansas, Missouri, and Oklahoma) and 4.6% in the southeast region (Georgia, Maryland, North Carolina, South Carolina, Tennessee and Virginia). Seroreactivity to E. ewingii was also highest in the central region (14.6%) followed by the southeast region (5.9%). The geospatial pattern derived from E. chaffeensis and E. ewingii seropositive samples was similar to previous reports based on E. chaffeensis seroreactivity in white-tailed deer and the distribution of human monocytic ehrlichiosis (HME) cases reported by the CDC.

CONCLUSIONS

The results of this study provide the first large scale regional documentation of exposure to E. canis, E. chaffeensis and E. ewingii in pet dogs, highlighting regional differences in seroprevalence and providing the basis for heightened awareness of these emerging vector-borne pathogens by veterinarians and public health agencies.

Uropathogenic E. coli promote a paracellular urothelial barrier defect characterized by altered tight junction integrity, epithelial cell sloughing and cytokine release

The urinary bladder is a common site of bacterial infection with a majority of cases attributed to uropathogenic Escherichia coli. Sequelae of urinary tract infections (UTIs) include the loss of urothelial barrier function and subsequent clinical morbidity secondary to the permeation of urine potassium, urea and ammonia into the subepithelium. To date there has been limited research describing the mechanism by which this urothelial permeability defect develops. The present study models acute uropathogenic E. coli infection in vitro using intact canine bladder mucosa mounted in Ussing chambers to determine whether infection induces primarily a transcellular or paracellular permeability defect. The Ussing chamber sustains tissue viability while physically separating submucosal and lumen influences, so this model is ideal for quantitative measurement of transepithelial electrical resistance (TER) to assess alterations of urothelial barrier function. Using this model, changes in both tissue ultrastructure and TER indicated that uropathogenic E. coli infection promotes a paracellular permeability defect associated with the failure of umbrella cell tight junction formation and umbrella cell sloughing. In addition, bacterial interaction with the urothelium promoted secretion of cytokines from the urinary bladder with bioactivity capable of modulating epithelial barrier function including tumour necrosis factor-α, interleukin (IL)-6 and IL-15. IL-15 secretion by the infected bladder mucosa is a novel finding and, because IL-15 plays key roles in reconstitution of tight junction function in damaged intestine, this study points to a potential role for IL-15 in UTI-induced urothelial injury.

Molecular prevalence of Bartonella, Babesia, and hemotropic Mycoplasma sp. in dogs with splenic disease

BACKGROUND

Among diseases that cause splenomegaly in dogs, lymphoid nodular hyperplasia (LNH), splenic hemangiosarcoma (HSA), and fibrohistiocytic nodules (FHN) are common diagnoses. The spleen plays an important role in the immunologic control or elimination of vector-transmitted, blood-borne pathogens, including Bartonella sp., Babesia sp., and hemotropic Mycoplasma sp.

OBJECTIVE

To compare the prevalence of Bartonella sp., Babesia sp., and hemotropic Mycoplasma sp. DNA in spleens from dogs with LNH, HSA, and FHN.

MATERIALS AND METHODS

Paraffin-embedded, surgically obtained biopsy tissues from LNH (N = 50), HSA (N = 50), and FHN (N = 37) were collected from the anatomic pathology archives. Spleens from specific pathogen-free (SPF) dogs (N = 8) were used as controls. Bartonella sp., Babesia sp., and Mycoplasma sp. DNA was amplified by PCR, followed by DNA sequencing.

RESULTS

Bartonella sp. DNA was more prevalent in FHN (29.7%) and HSA (26%) as compared to LNH (10%) (P = .019, .0373, respectively) or control spleens (0.0%). The prevalence of Babesia sp. and hemotropic Mycoplasma sp. DNA was significantly lower than Bartonella sp. DNA in HSA (P = .0005, .006, respectively) and FHN (P = .003, .0004, respectively). There was no statistically significant difference in DNA prevalence among the 3 genera in the LNH group.

CONCLUSIONS

The higher prevalence of Bartonella sp. in FHN and HSA warrants future investigations to determine if this bacterium plays a role in the development of these splenic diseases.

Identification of Bartonella henselae in 2 cats with pyogranulomatous myocarditis and diaphragmatic myositis

Most cats infected with Bartonella henselae remain outwardly healthy carriers for years; however, self-limiting fever, transient anemia, neurologic dysfunction, lymphadenopathy, reproductive disorders, aortic valvular endocarditis, and neutrophilic myocarditis have been described in experimentally or naturally infected cats. Two cats in a North Carolina shelter died with pyogranulomatous myocarditis and diaphragmatic myositis. Bacteria were visualized in the lesions by Warthin-Starry silver impregnation and by B. henselae immunohistochemistry. B. henselae DNA was amplified and sequenced from the heart of 1 cat and from multiple tissue samples, including heart and diaphragm, from the second cat. This study supports a potential association between B. henselae and what has been historically described as "transmissible myocarditis and diaphragmitis" of undetermined cause in cats.

Evaluation of brain tissue or cerebrospinal fluid with broadly reactive polymerase chain reaction for Ehrlichia, Anaplasma, spotted fever group Rickettsia, Bartonella, and Borrelia species in canine neurological diseases (109 cases)

BACKGROUND

Vector-transmitted microorganisms in the genera Ehrlichia, Anaplasma, Rickettsia, Bartonella, and Borrelia are commonly suspected in dogs with meningoencephalomyelitis (MEM), but the prevalence of these pathogens in brain tissue and cerebrospinal fluid (CSF) of dogs with MEM is unknown.

HYPOTHESIS/OBJECTIVES

To determine if DNA from these genera is present in brain tissue and CSF of dogs with MEM, including those with meningoencephalitis of unknown etiology (MUE) and histopathologically confirmed cases of granulomatous (GME) and necrotizing meningoencephalomyelitis (NME).

ANIMALS

Hundred and nine dogs examined for neurological signs at 3 university referral hospitals.

METHODS

Brain tissue and CSF were collected prospectively from dogs with neurological disease and evaluated by broadly reactive polymerase chain reaction (PCR) for Ehrlichia, Anaplasma, Spotted Fever Group Rickettsia, Bartonella, and Borrelia species. Medical records were evaluated retrospectively to identify MEM and control cases.

RESULTS

Seventy-five cases of MUE, GME, or NME, including brain tissue from 31 and CSF from 44 cases, were evaluated. Brain tissue from 4 cases and inflammatory CSF from 30 cases with infectious, neoplastic, compressive, vascular, or malformative disease were evaluated as controls. Pathogen nucleic acids were detected in 1 of 109 cases evaluated. Specifically, Bartonella vinsonii subsp. berkhoffii DNA was amplified from 1/6 dogs with histopathologically confirmed GME.

CONCLUSION AND CLINICAL IMPORTANCE

The results of this investigation suggest that microorganisms in the genera Ehrlichia, Anaplasma, Rickettsia, and Borrelia are unlikely to be directly associated with canine MEM in the geographic regions evaluated. The role of Bartonella in the pathogenesis of GME warrants further investigation.