Fatal meningitis in a calf caused by Mannheimia varigena

Mannheimia varigena was identified as the etiologic agent of meningitis in a young Belgian White Blue heifer calf. Species identification of the bacterium was done by phenotyping and molecularly confirmed by tDNA-PCR. Standard bacteriological examination might fail to differentiate species belonging to the genus Mannheimia.     

Endectocide activity of a new long-action formulation containing 2.25% ivermectin+1.25% abamectin in cattle

The present work aimed to evaluate the endectocide activity of a new injectable long-action formulation, containing ivermectin (IVM) and abamectin (ABA). In each one of the four experiments performed, the following groups were formed: group I: 2.25% IVM (450 microg/kg)+1.25% ABA (250 microg/kg), group II: 3.15% IVM (630 microg/kg) and group III: control. Eighteen bovine naturally infected by gastrointestinal nematoda were selected for anthelmintic evaluation and necropsied on posttreatment day (PTD) 14 to estimate the total parasitic burden. For the Rhipicephalus (Boophilus) microplus field trial, 30 bovine were selected by means of counts of semi-engorged R. (B.) microplus and the therapeutic and residual efficacy evaluated by tick counts on PTDs 1, 3, 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84 and 91. In the stall test, 15 calves were artificially infested with 5000 R. (B.) microplus (Mozzo strain) larvae three times a week and daily collections of all the engorged female ticks detached from each calf were performed until the PTD 80. Forty bovine naturally infected with Dermatobia hominis larvae were selected and the number of larvae was counted by visual and tactile inspection on PTDs 3, 7, 14, 28, 35, 49, 63, 77, 91 and 105. In this trial, a formulation containing 1% doramectin (200 microg/kg) was also used. IVM+ABA formulation and 3.15% IVM eliminated four of the eight species of nematode identified. The anthelmintic efficacy of the avermectins association against Haemonchus placei, Cooperia spatulata and C. punctata was 89.64%, 98.84% and 97.69%, while 3.15% IVM achieved 30.98%, 84.79% and 75.56%, respectively. The two formulations evaluated showed reduced acaricide action on the PTD 1 and 3, reaching high efficacy percentages from PTD 14 onward. The IVM+ABA showed efficacy above 95% in the period between PTDs 21 and 49. In the stall test, it observed no difference (P>0.05) between the two formulations regarding the R. (B.) microplus counts during the entire evaluation period. IVM+ABA reduced the number of ticks from the PTD 1 to 77 (P<0.05) and 3.15% IVM reduced (P<0.05) the tick number from PTD 4 up to PTD 80. The three endectocides showed no difference (P>0.05) regarding the number of D. hominis larvae and prevented this parasite reestablishment until PTD 105. These results indicate that the IVM+ABA association showed higher anthelmintic activity and similar efficacy against arthropods to the formulation containing 3.15% IVM.     

Sheep helminth parasitic disease in south eastern Scotland arising as a possible consequence of climate change

The climate in the UK is changing, with a trend towards increased rainfall in the autumn and winter and warmer average temperatures throughout the year. There has also been a 4-week extension of the herbage growing season over the past 40 years. These changes may have implications for the epidemiology of sheep helminth parasites. Here, we describe production-limiting disease outbreaks caused by Haemonchus contortus, Nematodirus battus, Teladorsagia circumcincta and Fasciola hepatica in sheep flocks in south eastern Scotland. The occurrence and timing of these disease outbreaks could not have been predicted in this region highlighting changes in the epidemiology of helminth infections from the patterns historically described. These cases are used to introduce discussion regarding the potential effects of climate change on the epidemiology of helminth parasites and the implications for sheep farming in the UK.     

Vaccination against fasciolosis by a multivalent vaccine of stage-specific antigens

Liver flukes produce cathepsin B and cathepsin L in their excretory–secretory material. These proteases are proposed to be key virulence factors for parasite infection, and are therefore targets for vaccination. Cathepsin B is predominately released in the juvenile stage of the life cycle, while different cathepsin L's are released throughout the cycle. Three proteases (cathepsin L5, cathepsin L1g and cathepsin B) were expressed in yeast from cDNA clones isolated from adult, metacercariae and newly excysted juvenile flukes respectively. Each was used singly or in combination to vaccinate rats that were subsequently challenged with Fasciola hepatica metercercariae. Each protein induced an immune response, and all groups vaccinated with recombinant protein yielded significantly fewer and smaller flukes than the control group. Maximal protection of 83% was seen in the group vaccinated with cathepsin B and cathepsin L5 in combination.     

Proliferative dermatitis in a loggerhead turtle, Caretta caretta, and a green turtle, Chelonia mydas, associated with novel papillomaviruses

A subadult loggerhead turtle, Caretta caretta, presented with generalized small, white, raised lesions over its neck, shoulders, and all four flippers. A juvenile green turtle, Chelonia mydas, recently treated for fibropapillomatosis, presented with four similar localized lesions on one flipper. To diagnose the conditions, biopsies of the lesions were taken for histopathology, electron microscopy, and molecular diagnostics. Histopathologic findings were similar in the two turtles and skin lesions were characterized by multifocal areas of epidermal hyperplasia accompanied by variation and abnormalities in the nuclear morphology of keratinocytes and a few intranuclear inclusions in some cells. Transmission electron microscopy revealed multiple epithelial cells with large intranuclear aggregates of virions consistent in morphology with papillomavirus. Papillomavirus was detected in samples from both turtles by polymerase chain reaction (PCR). Sequence analysis of the partial sequence of the papillomavirus E1 gene revealed two viruses (CcPV and CmPV) that were distinct from each other and from other species in Papillomaviridae, and likely represent two novel species and perhaps a new genus.     

The Control of Parasitic Nematodes in Commercial Piggeries in Kenya as Reflected by a Questionnaire Survey on Management Practices

Tropical Animal Health and Production -     

Gastric Helicobacter species as a cause of feline gastric lymphoma: A viable hypothesis

Gastric Helicobacter spp. are associated with chronic inflammation and neoplastic transformation in humans as well as domestic and laboratory species. The present study examined the association of Helicobacter heilmannii (Hhe) infection in pet cats with feline gastric mucosa associated lymphoid tissue (MALT) lymphoma. Tissues were collected via gastric biopsy or at necropsy from 47 pet cats with clinical signs of gastrointestinal disease, including vomiting and inappetance, and classified as gastritis (14/47), lymphoma (31/37), or normal (2/47). Tissues positive for argyrophilic organisms with Warthin–Starry stain (29/47) were assessed by fluorescent in situ hybridization (FISH) for the presence of Hhe strains 1–4 as well as with a fifth probe that detected Helicobacter salomonis, Helicobacter bizzozeronii, or Helicobacter felis. A significant association of positive Warthin–Starry status with Hhe infection was found in cases of sick cats (22/29; p < 0.05 by Chi-square; χ² = 7.034). Interestingly, a significant association between Hhe status and a diagnosis of lymphoblastic or lymphocytic lymphoma was observed as well in a subset of 24 Warthin–Starry positive lymphoma cases: of lymphoblastic lymphoma cases, 13/17 were positive for Hhe (p < 0.05; χ² = 4.854). Hhe strains 2 and 4 were most commonly found (18/29 and 17/29, respectively) among sick cats, although a higher than expected number of cats was also positive for Hhe1, which initial reports have described as rare in cats and common in humans. The association found between a positive Hhe status with the presence of feline gastric lymphoma, especially lymphoblastic lymphoma, argues for the need to conduct prospective studies to better identify the frequency and strain distribution of Hhe infection in both healthy and clinically ill cats, particularly those cats with gastric lymphoma.     

The effect of polyethylene glycol on browsing behaviour of beef cattle in a tanniferous shrubby Mediterranean range

The aim of the present study was to determine the effect of polyethylene glycol (PEG) supplementation on grazing behaviour of beef cattle and on utilization of the woody components of a Mediterranean shrubland. Two experiments were conducted on two different sites in Northern Israel, Ramat Hanadiv (RH) and Hatal. On each site, the study area was divided into two paddocks, in one cattle were supplemented with 50 g PEG day^− 1 per cow, while the other served as a control, with no PEG supplementation. In RH site the cows had free access to Prolix and in Hatal to poultry litter, both serving as a nitrogen supplement during the experiment. In the RH site, the consumption of Pistacia lentiscus, a shrub whose leaves contain high concentration of tannins, was found higher (P = 0.001) in the PEG group diet than in the control group. In Hatal site PEG increased foraging time by 18%, daily foraging distance by 15% and reduced the use of supplementary feed (poultry litter) by 20%. However, PEG did not affect the average cow body weight or water consumption on either site. It is concluded that PEG influences grazing behaviour of beef cattle on shrubby rangeland and increases the use of woody species with high tannin concentrations.     

Seeking a niche: putative contributions of the hfq and bacA gene products to the successful adaptation of the brucellae to their intracellular home

Long-term residence of the brucellae in the phagosomal compartment of host macrophages is essential to their ability to produce disease in both natural and experimental hosts. Correspondingly, the Brucella spp. appear to be well adapted to resist the multiple environmental stresses they encounter in their intracellular home. This brief review will focus on the contributions of the hfq and bacA gene products to this adaptation. Studies with Brucella hfq mutants suggest that stationary phase physiology is critical for successful long-term residence in host macrophages. Analysis of Brucella bacA mutants, on the other hand, reveal very striking parallels between the strategies employed by the rhizobia to establish and maintain protracted intracellular residence in their plant host and those used by the brucellae during their long-term survival in the phagosomal compartment of host macrophages.     

Detection of a novel hemoplasma based on 16S rRNA gene DNA in captive and free-ranging capybaras (Hydrochaeris hydrochaeris)

Two different species of hemoplasmas, Mycoplasma coccoides and M. haemomuris, are known to infect small rodents such as mice and rats. However, there are no previous reports of hemoplasma infection in capybara (Hydrochaeris hydrochaeris). The aim of our study was to determine whether these hemoplasmas might infect capybaras from Southern Brazil. Blood samples from 31 animals: 10 captive and 21 free-ranging capybaras were collected and packed cell volume and total plasma protein were measured. DNA was extracted and PCR assays for M. coccoides and M. haemomuris were performed. Using the M. coccoides-PCR assay 64% of the capybaras were positive, 80% free-ranging and 30% from captive animals. The prevalence of infection between the groups was significantly different (p = 0.001). Sequencing of the nearly entire 16S rRNA gene from the positive samples suggested a novel hemoplasma isolate with identity of 92% with M. coccoides and 86% with M. haemomuris. All capybara samples were negative for M. haemomuris infection. DNA of a housekeeping gene was successfully amplified from all samples. This is the first evidence of a hemoplasma infection in capybaras.     

Heterologous Expression of a Gene Encoding a 35 kDa Protein of Mycobacterium avium paratuberculosis in Escherichia coli

The full-length open reading frame coding for a potentially immunogenic 35 kDa protein of Mycobacterium avium paratuberculosis was generated using polymerase chain reaction technology. The gene was inserted in-frame into Escherichia coli expression plasmid pQE32. The resulting recombinant plasmid pPMP35 was transformed into E. coli M15. Analysis of the E. coli induced with isopropyl-beta-D-thiogalactopyranoside revealed that the protein accumulated into the cytoplasm as insoluble inclusion bodies. The level of expression of the recombinant 35 kDa protein (P35) was more than 30% of the total protein of E. coli cells. Expression of the recombinant protein was confirmed by immunoblotting. The P35 reacted with a rabbit antiserum raised against a sonicate of M. a. paratuberculosis. The protein was also recognized by serum from a goat with clinical paratuberculosis. Further, a polyclonal antiserum against P35 recognized a 35 kDa band in a membrane fraction of M. a. paratuberculosis. Also, the protein provoked a significant skin reaction in outbred guinea pigs sensitized with M. a. paratuberculosis, as well as in those sensitized with Mycobacterium avium. The results indicate that the 35 kDa protein of M. a. paratuberculosis is a membrane protein, having a role in the cellular immune response.     

Identification and Serological Specificity of a Polysaccharide Component from Mycoplasma bovis

Whole-cell lysate and proteinase K digest preparations of the Mycoplasma bovis type strain (American Type Culture Collection 25523) were compared using sodium dodecyl sulfate polyacrylamide gel electrophoresis. Coomassie blue staining for protein revealed approximately 50 bands for the lysate but only a single band for the digest. Silver staining for polysaccharide revealed at least 19 bands for the digest. Fourteen monoclonal antibodies (MAbs) were produced using a screening procedure with an M. bovis digest. On immunoblots of digests of four M. bovis strains, an almost identical profile was seen with each strain for all 14 MAbs but differences were evident between strains. One MAb, M1557, was used to analyse 17 M. bovis strains on immunoblots. Ten to 20 bands were observed with 16 of the 17 strains, and differences were apparent among all 16 strains. In an enzyme-linked immunosorbent assay, M1557 reacted with 16 of the 17 M. bovis strains, but did not react with any of 41 non-M. bovis organisms tested. Strong reactions were observed with the MAbs and M. bovis colonies in immunofluorescence. The M. boris polysaccharide and MAbs to this component may be useful for the development of diagnostic assays for this organism.     

Brain abscess in a dog immunosuppressed using cyclosporin

This report describes a dog that developed brain abscesses following prolonged immunosuppression with cyclosporin. Bacteria within the abscess were most likely Nocardia, an organism well recognised in immunosuppressed humans, and probably reached the brain through haematogenous spread from a more long-standing abscess in the mediastinum. Bacterial brain abscesses developing in this manner are very rare in dogs and this case highlights the wider range of possible diagnoses that need to be considered in immunosuppressed patients and the care with which potent drugs such as cyclosporin should be used.     

Anaplasma marginale infection in a Japanese Black cow 13 years after eradication of Rhipicephalus (Boophilus) microplus in Okinawa, Japan

In October 2007, a 15-year-old Japanese Black cow on Ishigaki Island, Okinawa, Japan, was diagnosed with Anaplasma marginale infection based on clinical symptoms, blood examination, smear observation, 16S rRNA and groEL gene sequence analysis, and the result of a CF test. The cow was introduced into the farm from mainland Japan as a calf in 1993, one year before the eradication of Rhipicephalus (Boophilus) microplus, the main vector of A. marginale in Okinawa Prefecture. It is possible that the cow was first infected with A. marginale as a calf in Ishigaki Island and had been persistently infected since then. This is the first reported clinical case of A. marginale infection of cattle since the eradication of R. microplus in Okinawa Prefecture. Additional analysis of major surface protein 1α amino acid sequences revealed that the A. marginale Okinawa strain presented four new repeat forms which were not seen in other strains. This indicates that the Okinawa strain may be a unique geographical variant of A. marginale.     

Isolation of Moellerella wisconsensis from the lung of a goat

This report describes the first isolation of Moellerella wisconsensis from the lung of a goat in Italy and represents the fourth isolation of this rare enterobacterial species from non-human sources reported in the literature. In fact, since its first isolation, M. wisconsensis has only been described in a few other occasions and often in clinical samples associated with cases of human enteritis.     

Exclusion of DMRT1 as a candidate gene for canine SRY-negative XX sex reversal

DMRT1, which encodes a zinc finger-like DNA binding motif, is a well-conserved gene that is involved in testis differentiation in a variety of mammalian and non-mammalian vertebrates. The objective of this study was to determine whether a DMRT1 microsatellite marker allele is associated with the affected phenotype in a pedigree of canine SRY-negative XX sex reversal generated from an American Cocker spaniel founder. Ten affected dogs and their parents and grandparents were genotyped. Four alleles at this locus and five different genotypes were found in this pedigree. All affected dogs inherited this trait from the foundation sire of this colony. Thus, the disease-causing mutation should be identical by descent in all affected dogs. Six affected dogs were found to have genotypes at this locus that were different from those of the founder sire. These results indicate that DMRT1 is an unlikely candidate gene for SRY-negative XX sex reversal in this model.     

An increased incidence of mastitis caused by Prototheca species and Nocardia species on a farm in São Paulo,Brazil

Mastitis caused by Prototheca spp or Nocardia spp is considered to be difficult to treat. Both microorganisms are contaminants commonly found in soil. The occurrence of mastitis caused by these agents was studied in a particular dairy farm. In this herd, the animals were kept at pasture overnight and during daytime were brought to a pen where they were fed. This pen accumulated mud and faeces, particularly in the rainy season. During milking, pre-dipping of the teats was performed with an iodide solution, but they were not washed, so a layer of soil and faeces remained which may have contaminated the milking equipment. The herd comprised 91 lactating animals and 47 dry cows. For microbiological examination, 107 milk samples were collected from lactating cows and 186 samples of mammary secretions from the dry cows. Prototheca spp were isolated from 14.55% of the milk samples and Nocardia spp from 4.55%. Prototheca spp were isolated from 8.06% of the secretion samples from dry cows and Nocardia spp were isolated from 2.15% samples. The high occurrence of mastitis due to these environmental agents reflects the problem of keeping animals in muddy pastures and pens, and the defective pre-milking hygiene for the teats.