Experimental infection of four horses with Ehrlichia phagocytophila

Four clinically healthy horses which were negative for antibodies to Ehrlichia phagocytophila, the agent of bovine ehrlichiosis, were infected experimentally with E phagocytophila-containing bovine leucocytes, administered intravenously. The horses were examined daily for four weeks, and blood samples were collected daily for cytological, haematological and biochemical examination and for a nested polymerase chain reaction (PCR). An indirect immunofluorescence test was used to determine when the horses seroconverted and the duration of positive titres. There were no abnormal clinical, haematological or biochemical findings in any of the four horses and all the PCRs yielded negative results. However, all the horses seroconverted with reciprocal titres of up to 1280, and the positive titres persisted for up to five months.     

Kinetics of serologic cross-reactions between Ehrlichia canis and the Ehrlichia phagocytophila genogroups in experimental E. canis infection in dogs

The serological cross-reactions between the Ehrlichia canis and Ehrlichia phagocytophila genogroups, and the kinetics of development of antibodies in dogs to the E. phagocytophila group after artificial infection with the Israeli strain of E. canis was investigated. Results of this study indicate that the development of antibodies to the E. phagocytophila genogroup in dogs after infection with E. canis is a time dependent event probably conditional on the continued propagation of the rickettsia in the host. After spontaneous clinical recovery, and at the beginning of the subclinical phase, no antibodies to E. phagocytophila were yet detectable. The first evidence of IgG antibodies to E. phagocytophila were found in two of the six dogs, 55 days after artificial infection with E. canis, while another two dogs became seropositive to E. phagocytophila 22 days later. All surviving dogs were seropositive to E. phagocytophila by 150 days PI. It is suggested that the appearance of E. phagocytophila antibodies following treatment of acute E. canis infection may be used to judge treatment failure and/or persistence of infection.     

Persistence of Ehrlichia phagocytophila infection in lambs in relation to clinical parameters and antibody responses

Five lambs were infected experimentally with Ehrlichia phagocytophila and examined regularly during the next six months. The lambs all had recurrences of parasitaemia at various times but had a fever on only 21 per cent of these occasions. A reduced number of leucocytes was observed in all the lambs for at least eight weeks. All the lambs were still infected four months after inoculation with E phagocytophila. After six months, blood from four of the five lambs was infective when inoculated into susceptible lambs.     

Experimental oral transmission of Ehrlichia phagocytophila to calves

Three groups of four calves were used to determine whether Ehrlichia phagocytophila could be transmitted orally to calves via infected milk. Groups 1 and 2 consisted of four-week-old calves and group 3 of newborn calves. The calves in group 1 were fed for several days with milk from cows infected experimentally with E phagocytophila. The calves in groups 2 and 3 were fed 200 ml of whole blood containing E phagocytophila organisms; for group 2 the blood was added to milk before being fed, and for group 3 the blood was added to colostrum before being fed within three hours after birth. Blood samples for haematological, serological and cytological examination, and for polymerase chain reaction (PCR) were collected from all the calves, starting on the first or only day of administration and then every four days for four weeks. The calves of groups 1 and 2 showed no clinical, haematological or serological changes, and there was no direct or indirect evidence of the agent. In contrast, all the calves in group 3 had mild pyrexia and seroconverted on day 8, and in one of them E phagocytophila organisms were visible in leucocytes, and the PCR on the buffy coat was positive on day 8.     

Identification of a granulocytic Ehrlichia strain isolated from a horse in Switzerland and comparison with other rickettsiae of the Ehrlichia phagocytophila genogroup

This case report describes a 12-year-old Arabian mare with granulocytic ehrlichiosis. Clinical signs included fever, apathy, anorexia, icterus, limb edema, and reluctance to move. Examination of buffy coat smears revealed Ehrlichia organisms in neutrophils and eosinophils. A band of 1,428 bp was amplified from DNA of leukocytes via nested PCR and was identified as part of the Ehrlichia 16S rRNA gene. It differed from the gene sequences of Ehrlichia phagocytophila and E. equi at two and three positions, respectively. Interestingly, the nucleotide sequence of the 16S rRNA was 100% identical to that of the agent of human granulocytic ehrlichiosis.     

Detection of Ehrlichia phagocytophila DNA in Ixodes ricinus ticks from areas in Switzerland where tick-borne fever is endemic

A total of 1,523 adult Ixodes ricinus ticks were collected from regions where bovine ehrlichiosis is endemic and were examined for Ehrlichia phagocytophila via PCR. Of the ticks from cattle with ehrlichiosis, the ticks from healthy cattle, and the free-living ticks, 26.5% (18 of 68), 4.4% (35 of 802), and 0.8% (5 of 653), respectively, were positive.     

Seroprevalence of Ehrlichia canis and of canine granulocytic Ehrlichia infection in dogs in Switzerland

Serum samples from 996 dogs in Switzerland were examined for antibodies to Ehrlichia canis and to the agent causing canine granulocytic ehrlichiosis (CGE). Ehrlichiosis, borreliosis, and systemic illness not associated with ticks were suspected in 75, 122, and 157 of these dogs, respectively. The remainder of the serum samples were obtained from clinically healthy dogs which resided north (n = 235) or south (n = 407) of the Alps. The serum samples were tested by an indirect immunofluorescence technique for antibodies to the two agents incriminated, E. canis and Ehrlichia phagocytophila, a surrogate marker of the agent of CGE. Twenty-two of 996 (2.2%) serum samples had antibodies to E. canis and were distributed as follows: 20 of 75 (26.7%) samples from dogs suspected of having ehrlichiosis, 1 of 122 (0.8%) from dogs suspected of having borreliosis, and 1 of 407 (0.2%) from healthy dogs which resided south of the Alps. Of the 75 (7.5%) serum samples that had antibodies to E. phagocytophila, significantly more samples were from ill dogs than from healthy dogs. Among the sera from healthy dogs, antibodies to E. phagocytophila were significantly more prevalent in the north. Because seropositive dogs had a history of travel outside Switzerland and because Rhipicephalus sanguineus is found exclusively south of the Alps, it was presumed that, in contrast to the agent of CGE, E. canis is not indigenous to Switzerland.     

Comparison of nested PCR with immunofluorescent-antibody assay for detection of Ehrlichia canis infection in dogs treated with doxycycline

A partial 16S rRNA gene was amplified in Ehrlichia canis-infected cells by nested PCR. The assay was specific and did not amplify the closely related Ehrlichia chaffeensis, Ehrlichia muris, Neorickettsia helminthoeca, and SF agent 16S rRNA genes. The assay was as sensitive as Southern hybridization, detecting as little as 0.2 pg of E. canis DNA. By this method, all blood samples from four dogs experimentally infected with E. canis were positive as early as day 4 postinoculation, which was before or at the time of seroconversion. One hundred five blood samples from dogs from Arizona and Texas (areas of E. canis endemicity) and 30 blood samples from dogs from Ohio (area of E. canis nonendemicity) were examined by nested PCR and immunofluorescent-antibody (IFA) test. Approximately 84% of dogs from Arizona and Texas had been treated with doxycycline before submission of blood specimens. Among Arizona and Texas specimens, 46 samples were PCR positive (44%) and 80 were IFA positive (76%). Forty-three of 80 IFA-positive samples (54%) were PCR positive, and 22 of 25 IFA-negative samples (88%) were negative in the nested PCR. None of the Ohio specimens were IFA positive, but 5 specimens were PCR positive (17%). Our results indicate that the nested PCR is highly sensitive and specific for detection of E. canis and may be more useful in assessing the clearance of the organisms after antibiotic therapy than IFA, especially in areas in which E. canis is endemic.     

Use of electromyography in a cow with esophageal paralysis

Electromyography of the esophageal musculature of a cow that had been regurgitating and losing weight after correction of an esophageal obstruction was suggestive of unilateral denervation. Radiography before and after oral administration of barium sulfate revealed a dilated terminal portion of the thoracic esophagus, suggestive of a focal motility problem. Electromyography was performed on the esophageal musculature by positioning the electrode through the rumen fistula and into the thoracic esophagus and by positioning the electrode percutaneously with the aid of a tube placed in the cervical esophagus. Numerous fibrillation potentials and sharp epsilon-positive waves were detected in the muscles of the left side of the distal portions of the cervical and thoracic esophagus. During hospitalization, the cow was given alfalfa pellets, ground corn, and sodium bicarbonate through the rumen fistula 3 times each day for several weeks to maintain body weight.     

Granulocytic Ehrlichia infection in ixodid ticks and mammals in woodlands and uplands of the U.K

BACKGROUND: The number of patients waiting lung transplantation greatly exceeds the supply of donors. This study was conducted to determine the effect of high-dose steroid administration on oxygenation and donor lung recovery after brain death. METHODS: A retrospective analysis was conducted on 118 consecutive organ donors from January 1 through December 31, 1995. Eighty donors received high-dose steroids (methylprednisolone, mean 14.5+/-0.06 mg/kg) after organ procurement organization management began; a second group was composed of 38 patients who received no steroids. PaO2/FiO2 ratios were used to evaluate oxygenation. The number of single and double lungs transplanted served as the endpoint. RESULTS: No differences were noted in hemodynamics, most clinical or demographic variables and initial values of PaO2/FiO2 between groups. However, nonsteroid-treated donors showed an overall decrease in oxygenation (mean decrease in PaO2/FiO2 -34.2+/-14), whereas steroid-treated donors had a significant and progressive increase in oxygenation (mean increase in PaO2/FiO2: 16+/-14) before aortic cross-clamping (p = 0.01). Time before cross-clamping was longer in the steroid-treated patients (p = 0.003). The number of procured lungs was markedly greater in steroid-treated than nonsteroid-treated donors (25/80 patients vs 3/38; p < 0.01). CONCLUSIONS: High-dose methylprednisolone given during donor management results in improved oxygenation at organ recovery. This treatment resulted in a significant increase in the number of lungs transplanted and may have enabled donors to be treated longer.     

Invasive malignant fibrous histiocytoma in a cow

An invasive malignant fibrous histiocytoma associated with the left cornual process, and causing lysis of the frontal bone, was diagnosed in a cow. The mass compressed the left cerebral hemisphere focally and extended into the frontal sinus and ethmoid and nasal turbinates. It was composed of pleomorphic to spindle-shaped cells with ultra-structural evidence of fibroblastic, myofibroblastic, and fibrohistiocytic differentiation. Trauma and chronic inflammation may be predisposing factors for development of neoplasia in cattle.     

Dogs infected with a human granulocytotropic Ehrlichia spp. (Rickettsiales: Ehrlichieae)

In contrast to the anticipation that in sepsis granulocyte colony-stimulating factor (G-CSF) would overactivate the nonspecific immune system by recruiting and priming leukocytes with consequent aggravation of inflammatory tissue lesions, recombinant (r) G-CSF pretreatment was protective in various experimental non-neutropenic models of inflammation. The mechanisms of protection, however, are not fully understood. Using intravital fluorescence microscopy, we show that rG-CSF enhances leukocyte endothelial cell interaction within the microvasculature of normal rat livers, whereas rG-CSF pretreatment of animals exposed to lipopolysaccharide (LPS) attenuates the LPS-induced leukocytic response, including stasis in sinusoids as well as rolling and adherence in postsinusoidal venules with subsequent tissue infiltration. Moreover, rG-CSF, which did not affect Kupffer cell activity in normal rat livers, reduced the immediate activation of Kupffer cells on LPS exposure, as indicated in vivo by the delayed adherence/phagocytosis of intra-arterially administered latex particles associated with attenuation of proinflammatory cytokine release (tumor necrosis factor alpha and interleukin-6). Finally, rG-CSF reduced LPS-induced nutritive perfusion failure and hepatocellular excretory dysfunction. This study provides evidence for a distinct, possibly tumor necrosis factor alpha-dependent modulation of LPS-induced cellular response within the liver by rG-CSF, thereby achieving protection against microcirculatory perfusion failure and hepatic dysfunction.     

Ruptured urinary bladder after dystocia in a cow

Rupture of the urinary bladder of a cow occurred secondary to prolonged dystocia. Primary surgical closure of the tear was performed after drainage of the uroperitoneum, and the cow recovered without complications.     

Surgical management of rectal and jejunal tears associated with dystocia in a cow

The rectal and jejunal tears associated with dystocia in a cow were treated surgically. The cow developed peritonitis which was treated medically. It recovered, was successfully rebred and delivered a live calf.     

Human exposure to a granulocytic Ehrlichia and other tick-borne agents in Connecticut

Indirect fluorescent-antibody (IFA) staining methods with Ehrlichia equi (MRK or BDS strains) and Western blot analyses containing a human granulocytic ehrlichiosis (HGE) agent (NCH-1 strain) were used to confirm probable human cases of infection in Connecticut during 1995 and 1996. Also included were other tests for Ehrlichia chaffeensis, the agent of human monocytic ehrlichiosis (HME), Babesia microti, and Borrelia burgdorferi. Thirty-three (8.8%) of 375 patients who had fever accompanied by marked leukopenia or thrombocytopenia were serologically confirmed as having HGE. Western blot analyses of a subset of positive sera confirmed the results of the IFA staining methods for 15 (78.9%) of 19 seropositive specimens obtained from different persons. There was frequent detection of antibodies to a 44-kDa protein of the HGE agent. Serologic testing also revealed possible cases of Lyme borreliosis (n = 142), babesiosis (n = 41), and HME (n = 21). Forty-seven (26.1%) of 180 patients had antibodies to two or more tick-borne agents. Therefore, when one of these diseases is clinically suspected or diagnosed, clinicians should consider the possibility of other current or past tick-borne infections.     

Intrauterine growth restriction: a genetic perspective

BACKGROUND: Anastrozole is a new oral aromatase inhibitor with highly potent and selective activity for the aromatase enzyme. In a Phase III trial, the efficacy and tolerability of anastrozole, given in doses of 1 and 10 mg orally once daily, and megestrol acetate, given in doses of 40 mg orally 4 times daily, were compared in 386 postmenopausal women with advanced breast carcinoma who progressed after tamoxifen therapy. METHODS: The trial was randomized, double blind for anastrozole, open label for megestrol acetate, parallel group, and multicenter. Patients were randomly assigned to receive anastrozole, 1 mg (n = 128); anastrozole, 10 mg (n = 130); or megestrol acetate (n = 128). The primary efficacy measures were time to progression and tumor response; secondary measures were time to treatment failure, duration of response, quality of life, and time to death. RESULTS: With a median duration of follow-up of 6 months, there was no statistical evidence of a difference between either 1 or 10 mg doses of anastrozole and megestrol acetate for any efficacy endpoint. According to rigid response criteria, 10%, 6%, and 6% of patients in the anastrozole 1 mg, anastrozole 10 mg, and megestrol acetate groups, respectively, had an objective response (complete response or partial response) and 27%, 24%, and 30% of patients in the respective groups had stable disease for a duration of 24 weeks or longer. Quality-of-life assessments revealed that anastrozole in a 1-mg dose was associated with better physical scores and anastrozole in a 10-mg dose with better psychologic scores than megestrol acetate. Both anastrozole and megestrol acetate were generally well tolerated. Among anticipated adverse events, gastrointestinal disturbance was more common among patients in the anastrozole groups, whereas weight gain occurred more frequently among patients in the megestrol acetate groups. Weight increases of 5% or more and 10% or more were more common among megestrol acetate-treated patients; moreover, patients in this group continued to gain weight over time. CONCLUSIONS: Anastrozole, given in doses of 1 and 10 mg once daily, represents a well tolerated and effective therapeutic option for the treatment of postmenopausal women with advanced breast carcinoma who progress after tamoxifen treatment.