This study aimed to evaluate protection induced by the vaccine candidate B. ovis ΔabcBA against experimental challenge with wild type B. ovis in rams. Rams were subcutaneously immunized with B. ovis ΔabcBA encapsulated with sterile alginate or with the non encapsulated vaccine strain. Serum, urine, and semen samples were collected during two months after immunization. The rams were then challenged with wild type B. ovis (ATCC25840), and the results were compared to non immunized and experimentally challenged rams. Immunization, particularly with encapsulated B. ovis ΔabcBA, prevented infection, secretion of wild type B. ovis in the semen and urine, shedding of neutrophils in the semen, and the development of clinical changes, gross and microscopic lesions induced by the wild type B. ovis reference strain. Collectively, our data indicates that the B. ovis ΔabcBA strain is an exceptionally good vaccine strain for preventing brucellosis caused by B. ovis infection in rams.
Listeria monocytogenes is a Gram-positive, facultative intracellular and invasive bacterium that has tropism to the placenta, and causes fetal morbidity and mortality in several mammalian species. While infection with L. monocytogenes and L. ivanovii are known as important causes of abortion and reproductive failure in cattle, the pathogenesis of maternal-fetal listeriosis in this species is poorly known. This study used the bovine chorioallantoic membrane explant model to investigate the kinetics of L. monocytogenes, L. ivanovii, and L. innocua infections in bovine trophoblastic cells for up to 8 h post infection. L. monocytogenes and L. ivanovii were able to invade and multiply in trophoblastic cells without causing cell death or inducing expression of pro-inflammatory genes. Although L. innocua was unable to multiply in bovine trophoblastic cells, it induced transcription of the pro-inflammatory mediator CXCL6. This study demonstrated for the first time the susceptibility of bovine trophoblastic cells to L. monocytogenes and L. ivanovii infection.
Brucella ovis infection is associated with epididymitis, orchitis and infertility in rams. Most of the information available on B. ovis and host cell interaction has been generated using murine macrophages or epithelial cell lines, but the interaction between B. ovis and primary ovine macrophages has not been studied. The aim of this study was to evaluate the role of the B. ovis abcEDCBA-encoded ABC transporter and the virB operon-encoded Type IV Secretion System (T4SS) during intracellular survival of B. ovis in ovine peripheral blood monocyte-derived macrophages. ΔabcBA and ΔvirB2 mutant strains were unable to survive in the intracellular environment when compared to the WT B. ovis at 48 hours post infection (hpi). In addition, these mutant strains cannot exclude the lysosomal marker LAMP1 from its vacuolar membrane, and their vacuoles do not acquire the endoplasmic reticulum marker calreticulin, which takes place in the WT B. ovis containing vacuole. Higher levels of nitric oxide production were observed in macrophages infected with WT B. ovis at 48 hpi when compared to macrophages infected with the ΔabcBA or ΔvirB2 mutant strains. Conversely, higher levels of reactive oxygen species were detected in macrophages infected with the ΔabcBA or ΔvirB2 mutant strains at 48 hpi when compared to macrophages infected with the WT strain. Our results demonstrate that B. ovis is able to persist and multiply in ovine macrophages, while ΔabcBA and ΔvirB2 mutations prevent intracellular multiplication, favor phagolysosome fusion, and impair maturation of the B. ovis vacuole towards an endoplasmic reticulum-derived compartment.
Abstract. It has been proposed, based on taxonomic and molecular studies, that all canine isolates belonging to Staphylococcus intermedius group (SIG) should be renamed Staphylococcus pseudintermedius. However, isolates of SIG and other coagulase-positive staphylococci share many phenotypic characteristics, which could lead to misidentification. The accuracy of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) for identifying S. pseudintermedius isolates obtained from canine infections was evaluated, using a polymerase chain reaction (PCR)-based identification as the gold standard. In addition, MALDI-TOF MS was compared with conventional biochemical tests. A central problem was the incorrect identification of S. pseudintermedius isolates as S. intermedius by either MALDI-TOF MS or biochemical identification. From the 49 S. pseudintermedius isolates identified by the molecular method, only 21 could be assigned to this species by the biochemical approach and only 12 by MALDI-TOF MS. The 6 S. aureus isolates were correctly identified by all 3 techniques. However, using biochemical tests, 9 S. pseudintermedius were mistakenly classified as S. aureus, indicating a reduced specificity relative to the MALDI-TOF MS system. Analysis with the MALDI-TOF MS platform allowed rapid and accurate identification of the 49 isolates to the S. intermedius group but the approach was very limited in identifying S. pseudintermedius isolates, as only 12 of 49 isolates were correctly identified, a sensitivity of 0.24 (95% confidence interval: 0.13-0.39).
BackgroundBrucella ovis infection is one of the leading causes of sub fertility and infertility in ovine, been characterized mainly by epididymitis, orchitis and testicular atrophy in rams. This study aimed to determine the frequency of B. ovis positivity in rams and goats flocks in the State of Minas Gerais, Brazil, by agarose gel immunodiffusion (AGID), ELISA, Rose Bengal, PCR and bacteriological isolation as diagnostic tools.FindingsSerum and urine samples were collected from properties with sheep or goat flocks, or from properties with mixed flock. Out of 50 sheep flocks, 6 % (3/50) were seropositive by AGID while 4 % (2/50) were positive by urine PCR for B. ovis. Out of five goat farms, 20 % (1/5) were seropositive for B. ovis by AGID. Mixed flock farms had 11.1 % (2/18) of positivity by AGID. By ELISA, 19.5 % (8/41) of sheep properties and 61.1 % (11/18) of the properties with mixed flocks were positive for B. ovis. No samples were positive in the test of Rose Bengal, ruling out exposure to smooth LPS Brucella species (particularly Brucella melitensis) and indicating that the positive in the ELISA was associated with Brucella spp. LPS rough (presumably B. ovis). No urine sample from sheep or goat was positive by bacteriological isolation.ConclusionsOur results demonstrate serologic or molecular evidence of B. ovis infection in several rams and billy goats from meso-regions of the State of Minas Gerais, Brazil. Also, this study report the indirect ELISA as an important tool for the diagnosis of B. ovis infection, as indirect ELISA in this study demonstrated to be the most sensitive diagnostic method adopted.
Ostrich raising around the world have some key factors and farming profit depend largely on information and ability of farmers to rear these animals. Non fertilized eggs from ostriches are discharged in the reproduction season. Staphylococcus aureus and Escherichia coli are microorganisms involved in animal and human diseases. In order to optimize the use of sub products of ostrich raising, non fertilized eggs of four selected birds were utilized for development of polyclonal IgY antibodies. The birds were immunized (200ug/animal) with purified recombinant staphylococcal enterotoxin C (recSEC) and synthetic recRAP, both derived from S. aureus, and recBFPA and recEspB involved in E. coli pathogenicity, diluted in FCA injected in the braquial muscle. Two subsequent immunization steps with 21 days intervals were repeated in 0,85% saline in FIA. Blood and eggs samples were collected before and after immunization steps. Egg yolk immunoglobulins were purified by precipitation with 19% sodium sulfate and 20% ammonium sulphate methodologies. Purified IgY 50μL aliquots were incubated in 850μL BHI broth containing 50μL inoculums of five strains of S. aureus and five strains of E.coli during four hours at 37°C. Growth inhibition was evaluated followed by photometry reading (DO550nm). Egg yolk IgY preparation from hiperimmunized birds contained antibodies that inhibited significantly (p<0,05) growth of strains tested. Potential use of ostrich IgY polyclonal antibodies as a diagnostic and therapeutic tool is proposed for diseased animals.
The presence of Leptospira spp. and Brucella spp. antibodies was investigated in serum samples from 28 collared anteaters (Tamandua tetradactyla) kept in seven Brazilian zoos. Sera were tested against 19 Leptospira serovars using microscopic agglutination. Samples reacted to the following serovars: two (7.14%) to Patoc, three (10.71%) to Tarrasovi, three (10.71%) to both Patoc and Tarrasovi, two (7.14%) to Wolffi, and one (3.57%) to Australis. Two (7.14%) samples reacted to the buffered Brucella antigen test, but no confirmatory reaction occurred using the 2-mercaptoethanol slow slide agglutination test. No sample was reactive in the agar gel immunodiffusion test for rugose species of Brucella. The presence of anti-leptospira agglutinins in captive T. tetradactyla serum indicates that this species may be susceptible to infection by these bacteria.
A male adult crocodile (Crocodylus niloticus) was diagnosed with systemic yeast infection. Histologically, there were extensive areas of necrosis in the lung, which were associated with a diffuse severe lympho-plasmo-histiocytic inflammatory infiltrate, with numerous multinucleated giant cells, and myriads of intralesional pseudo-hyphae and yeast like organisms within distended foveolae. Necrotic foci were also observed in the mucosa of the digestive tract, trachea, tunica intima of arteries, liver, and heart, with a marked inflammatory lympho-histiocytic infiltrate, with large numbers of epithelioid macrophages and giant cells, and intralesional and intravascular pseudo-hyphae and yeast-like organisms. Oval yeast structures with 4 to 6 μm in diameter and 5 to 8 μm thick paralleled-wall pseudo-hyphae were observed in PAS or GMS stained sections. PCR with DNA template extracted from paraffin embedded tissues amplified the D1/D2 domains of the large subunit rRNA gene, which was sequenced and found to be identical to sequences of a new species, isolated from rotting wood in Brazil, of the genus Spencermartinsiella, which its closest relative is Spencermartinsiella cellulosicola. Keywords: Crocodile. Crocodylus niloticus. Candidiasis. Spencermartinsiella sp. ResumoUm crocodilo macho adulto (Crocodylus niloticus) foi diagnosticado com infecção fúngica sustêmica. Histologicamente, havia extensas áreas de necrose no pulmão, que estavam associadas com infiltrado inflamatório linfo-plasmo-histiocitário, com numerosas células gigantes multinucleadas e miríade de pseudo-hifas e organismos leveduriformes intralesionais, dentro de favéolas distendidas. Focos necróticos também foram observados na mucosa do trato digestório, traquéia, túnica íntima de artérias, fígado e coração, com acentuado infiltrado inflamatório linfo-histiocitário, com grande número de macrófagos epitelioides e células gigantes e hifas e organismos leveduriformes intralesionais e intravasculares. Cortes corados por PAS e GMS evidenciaram estruturas leveduriformes ovais com 4 a 6 μm de diâmetro e pseudo-hifas de paredes espessas e paralelas com 5 a 8 μm. PCR realizado com DNA extraído de material parafinizado amplificou os domínios D1/D2 da subunidade maior do gene rRNA, cuja sequencia foi idêntica a sequências de uma nova espécie, isolada no Brasil de madeira em decomposição, do gênero Spencermartinsiella, cuja espécie mais próxima é Spencermartinsiella cellulosicola. Palavras-chave: Crocodilo. Crocodylus niloticus. Candidíase. Spencermartinsiella sp.Several yeast species are considered opportunistic pathogens of humans and animals. These yeasts are saprophytic and found on wet outer surfaces or mucosae of men and animals, including the skin, ear canal, conjunctival sac, mouth, digestive tract, as well as perianal, genital, and oral mucosae (CLEFF et al.,
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