Flow cytometric assay in peripheral blood of dogs--reference values for leukocytes from Brazilian beagles

Use of domestic reference values in the flow cytometry analysis is known to improve its accuracy by integrating local variations as gender, race and age. Up to date application of flow cytometry in veterinary medicine has been limited to describe the percentual values just for peripheral lymphocytes subsets of blood. We now report establishment of reference values for a wide range of proportional and absolute numbers of peripheral blood leukocytes, including T cells subsets, B cells, monocytes and eosinophils, applicable to the healthy population of Beagles in Brazil and other regions with similar demographic characteristics. Normal reference values were also established to estimate the gender-related differences. This information will provide clinical aid in the evaluation of immunologic status as well as standard values for experimental animals of dogs from Brazil and other similar regions.     

Characterization of antibiotic resistance genes and virulence factors in faecal enterococci of wild animals in Portugal

Antibiotic susceptibility was tested in 140 non-selected enterococci (73 Enterococcus faecalis, 45 E. faecium and 22 of other species) recovered from faecal samples of 77 wild animals in Portugal. Susceptibility testing for 11 antibiotics (vancomycin, teicoplanin, ampicillin, streptomycin, gentamicin, kanamycin, chloramphenicol, tetracycline, erythromycin, quinupristin-dalfopristin and ciprofloxacin) was determined by disk diffusion and agar dilution methods. Forty-four isolates (31.4%) showed susceptibility to all the antibiotics tested (5.5% of E. faecalis; 62.2% of E. faecium; and 78.6% of E. hirae). Neither ampicillin-resistance nor acquired-vancomycin-resistance was detected and 1.4% of the isolates showed high-level-resistance for gentamicin or streptomycin. Tetracycline and erythromycin resistances were shown in 28.6% and 20.1% of the isolates, respectively. Antibiotic resistance genes were studied by polymerase chain reaction (PCR) and sequencing and tet(M) + tet(L), erm(B) or aac(6')-aph(2') genes were detected in most of tetracycline-, erythromycin- or gentamicin-resistant enterococci respectively. Genes encoding virulence factors were studied by PCR and a wide variety of virulence genes were detected in most of E. faecalis isolates but were rarely found in E. faecium and not detected in the other species. The prevalence of genes encoding virulence factors in E. faecalis was as follows: cpd (98.6%), gelE (75.3%), agg (30.1%), fsr (17.8%), ace (9.6%) and esp (4.1%). Low percentages of antibiotic resistance was found in the faecal enterococci of wild animals but a wide variety of virulence genes were detected among E. faecalis isolates although were rare in the other species.     

Luteoforol,a flavan 4-ol,is induced in pome fruits by prohexadione-calciumand shows phytoalexin-like properties against <Emphasis Type="Italic">Erwinia amylovora</Emphasis>and other plant pathogens

Treatments with prohexadione-calcium led to lowered incidence of fire blight, scab and other diseases in pome fruit trees and other crop plants. In addition to acting as a growth regulator, prohexadione-calcium interferes with flavonoid metabolism and induces the accumulation of the 3-deoxycatechin luteoliflavan in shoots of pome fruit trees. Luteoliflavan does not possess any remarkable antimicrobial activity. Therefore luteoforol, its unstable and highly reactive precursor, has been tested in vitro for its bactericidal and fungicidal activities. Luteoforol was found to be highly active against different strains of Erwinia amylovora, the causal agent of fire blight, and all other bacterial and fungal organisms tested. Phytotoxic effects were also observed in pear plantlets. The results obtained indicate that prohexadione-calcium induces luteoforol as an active principle with non-specific biocidal properties. It is proposed that luteoforol is released upon pathogen attack from its cellular compartment and inhibits further disease development by destroying pathogen cells as well as by inducing a hypersensitive-like reaction in the host plant tissue. This mechanism would be closely analogous to the one known for structurally related phytoalexins in sorghum.     

Clinical disorders observed in anteaters (Myrmecophagidae,Edentata) in captivity

The major health problems found in 103 captive lesser anteaters (Tamandua tetradactyla) and giant anteaters (Myrmecophaga tridactyla), family Myrmecophagidae, are presented and correlated with management. The most common of 200 recorded clinical disorders involved the digestive system (26%), nutritional deficiency (20%), injury (15.5%), respiratory system (10%), skin (7%) and circulatory system (4.5%), but 13% of the cases were inconclusive. Parasites were identified in 48.5% of faecal samples, mainly the eggs of nematodes (40%), of which the commonest wereTrichuris spp (28%) andStrongyloides spp (11%); protozoa (16%), of which the commonest wereEimeria spp (10%),Entamoeba spp (5%) andGiardia spp (1%); and cestodes (8%) and acanthocephalids (1%). Bacteria cultured from the various materials includedSalmonella enteritidis, S. cholerasuis, Escherichia coli, Enterobacter aerogenes, Streptococcus spp andStaphylococcus spp. The ectoparasites found wereAmblyomma spp andOtodectis spp (Arthropoda, Acaridae).     

Experimental acute canine monocytic ehrlichiosis: clinicopathological and immunopathological findings

Clinical signs, humoral and cellular immune responses, and microscopic and gross tissue alterations resulting from acute experimental Ehrlichia canis infection in dogs were studied. Four dogs were inoculated with E. canis and four were used as uninfected controls. After a 10-14-day incubation period, infected dogs developed pyrexia up to 41 degrees C for 6-8 days. Antibody titers to E. canis antigen were demonstrable in all inoculated dogs at 30 days post-infection. Necropsy of infected animals revealed pale mucous membranes, generalized lymphadenopathy, splenomegaly, edema and ascites. Microcopically, the main lesions were: lymphoreticular hyperplasia in cortical areas of lymph nodes and spleenic white pulp, periportal accumulation of mononuclear cells and centrolobular fatty degeneration of the liver. Kidneys presented with glomerulonephritis characterized by interstitial mononuclear infiltration. Immunophenotyping of lymphocytes from lymph nodes and spleen sections displayed alterations in IgG, IgM, CD3+ and CD8+ cells population in infected dogs.     

Cervical syringohydromyelia secondary to a brainstem tumor in a dog

An 11-year-old male Pekingese was evaluated because of a history of head tilt. Neurologic examination revealed a right-sided head tilt, ataxia, scoliosis, and proprioceptive deficits. Diagnostic testing included magnetic resonance imaging (MRI) of the head and neck. After IV administration of gadopentetate dimeglumine, an extra-axial, highly contrast-enhanced mass in the brainstem, cerebellar herniation, and syringohydromyelia were detected via MRI. The dog was treated with corticosteroids and radiation therapy of the mass for 4 weeks (total dose, 42.5 Gy). Magnetic resonance imaging was repeated 9 weeks and 6 months after radiation therapy; compared with the initial findings, a reduction in the size of the brainstem mass was observed in both MRI scans. The third MRI scan also revealed a normal cerebellar shape, no evidence of herniation, and resolution of syringohydromyelia in the dog at that time. It is recommended that whenever syringohydromyelia is observed via MRI, a primary cause (cranial or caudal to the affected region) should be sought.     

Effect of focused and radial extracorporeal shock wave therapy on equine bone microdamage

OBJECTIVES : To determine whether bone microcracks are altered after application of focused and radial extracorporeal shock wave therapy (ESWT) to the equine distal limb. STUDY DESIGN : An ex vivo experimental model. SAMPLE POPULATION : A contralateral limb specimen was obtained from 11 Thoroughbred racehorses with a unilateral catastrophic injury. Distal limb specimens were also obtained from 5 non-racing horses. METHODS : Three separate skin-covered bone segments were obtained from the mid-diaphysis of the metacarpus (MC3) or metatarsus (MT3). Focused (9,000 shockwaves, 0.15 mJ/mm2, 4 Hz) and radial (9,000 shockwaves, 0.175 mJ/mm2, 4 Hz) ESWT treatments were randomized to the proximal and distal segments and the middle segment was used as a treatment control for pre-existing microcracks. After treatment, bone specimens were bulk-stained with basic fuchsin and microcracks were quantified in transverse calcified bone sections. RESULTS : ESWT had small but significant effects on microcracks. Microcrack density (Cr.Dn) and microcrack surface density (Cr.S.Dn) were increased after focused ESWT, whereas Cr.Le was increased after radial ESWT. In racing Thoroughbreds, Cr.Le increased with increased number of races undertaken. Cr.Dn and Cr.S.Dn were not significantly influenced by the number of races undertaken. CONCLUSION : ESWT has small but significant effects on bone microcracking ex vivo. CLINICAL RELEVANCE : These preliminary data suggest that ESWT has the potential to increase bone microcracking in equine distal limb bone in vivo. Such effects may be more pronounced in Thoroughbreds that are actively being raced, because in vivo microcracking increases with increased number of races undertaken.     

Detection of genes encoding virulence factors and bacteriocins in fecal enterococci of poultry in Portugal

Seventy-six Enterococcus isolates (43 E. faecalis, 30 E. faecium, two E. durans, and one E. hirae) recovered from fecal samples of poultry in a slaughterhouse (one isolate per fecal sample and one fecal sample per lot of animals) were studied for bacteriocin production and for the presence of genes encoding bacteriocins and virulence factors. The presence of genes encoding virulence factors (cpd, geE, fsr, ace, agg, and esp) and bacteriocins (entA, entB, entP, entQ, entAS-48, entL50A/B, cyl, and bac31) were studied by polymerase chain reaction in all enterococci. At least two virulence genes were detected in all 43 E. faecalis isolates, cpd and gelE being the most frequently detected genes (97.7%) followed by ace (62.8%), agg (39.5%), fsr (27.9%), and esp (2.3%). No virulence genes were detected in the other enterococcal species with the exception of one E. faecium and one E. durans isolates that harbored the gelE gene. Antimicrobial activity against eight indicator bacteria (including Listeria monocytogenes) was assayed in the enterococci, and 23 (30.3%) showed inhibitory activity against L. monocytogenes, the other 22 enterococci showing activity against indicator bacteria other than L. monocytogenes. Only the entA, entB, and cyl genes were detected in our study (entA + entB in nine E. faecium isolates and the cyl gene in seven E. faecalis isolates). A wide variety of virulence genes have been detected in fecal E. faecalis isolates from poultry, but not in the other enterococcal species. However, the presence of known bacteriocin structural genes is associated more with the E. faecium species.