Álan Maia Borges

Genital Lesions Associated with Visceral Leishmaniasis and Shedding of Leishmania sp. in the Semen of Naturally Infected Dogs

Although visceral leishmaniasis is primarily transmitted by a biological invertebrate vector, transmission in the absence of the vector has been reported, including venereal transmission in humans. Considering the possibility of venereal transmission, we studied genital lesions in dogs naturally infected with visceral leishmaniasis and shedding of Leishmania sp. in the semen. Approximately 200 dogs were serologically tested for anti-Leishmania antibodies and divided into three groups: 1) serologically negative dogs (n = 20), 2) asymptomatic serologically positive dogs (n = 20), and 3) symptomatic serologically positive dogs (n = 20). Samples from both testes, all segments of both epididymes, prostate gland, glans penis, and prepuce were histologically evaluated and processed for immunodetection of Leishmania sp. Semen samples were obtained from 22 symptomatic serologically positive dogs and processed for detecting Leishmania DNA by polymerase chain reaction. A significantly higher frequency of inflammation was observed in the epididymes, glans penis, and prepuce of dogs with visceral leishmaniasis, which was associated with a high frequency of immunohistochemically positive tissues (up to 95% of tissues from symptomatic dogs were positive by immunohistochemistry). Leishmania DNA was detected in eight of 22 semen samples from symptomatic dogs. Together these findings indicate that genital lesions and shedding of Leishmania sp. (donovani complex) in the semen are associated with visceral leishmaniasis. Additional studies should address the possibility of venereal transmission of the disease in the dog.

Explants of Intact Endometrium to Model Bovine Innate Immunity and Inflammation Ex Vivo

Bacterial infections commonly cause bovine endometritis and infertility via innate immune pathways. However, mechanistic studies using isolated cells or chopped tissue may be compromised by the disruption of endometrial architecture and release of damage‐associated molecular patterns. So, this study aimed to establish an ex vivo model of intact bovine endometrium to study innate immunity and inflammation.

NRAMP1 3′ Untranslated Region Polymorphisms Are Not Associated with Natural Resistance to Brucella abortus in Cattle

ABSTRACT The NRAMP1 gene encodes a divalent cation transporter, located in the phagolysosomal membrane of macrophages, that has been associated with resistance to intracellular pathogens. In cattle, natural resistance against brucellosis has been associated with polymorphisms at the 3′ untranslated region (3′UTR) of the NRAMP1 gene, which are detectable by single-strand conformational analysis (SSCA). This study aimed to evaluate the association between NRAMP1 3′UTR polymorphisms and resistance against bovine brucellosis in experimental and natural infections. In experimentally infected pregnant cows, abortion occurred in 42.1% of cows with a resistant genotype (SSCAr; n = 19) and in 43.1% of those with a susceptible genotype (SSCAs; n = 23). Furthermore, no association between intensity of pathological changes and genotype was detected. In a farm with a very high prevalence of bovine brucellosis, the percentages of strains of the SSCAr genotype were 86 and 84% in serologically positive (n = 64) and negative (n = 36) cows, respectively. Therefore, no association was found between the NRAMP1-resistant allele and the resistant phenotype in either experimental or naturally occurring brucellosis. To further support these results, bacterial intracellular survival was assessed in bovine monocyte-derived macrophages from cattle with either the resistant or susceptible genotype. In agreement with our previous results, no difference was observed in the rates of intracellular survival of B. abortus within macrophages from cattle with susceptible or resistant genotypes. Taken together, these results indicate that these polymorphisms at the NRAMP1 3′UTR do not affect resistance against B. abortus in cattle and that they are therefore not suitable markers of natural resistance against bovine brucellosis.

Determinação do valor energético de alimentos para ruminantes pelo sistema de equações

The objective was to evaluate the equations system for determination of the TDN of six forages (corn silage, sugar cane with 1% urea, coastcross grass hay 1, coastcross grass hay 2, tifton grass haylage and elephant grass) and 12 concentrate feeds (corn grain ground, sorghum grain ground, corn germ, wheat bran, rice bran, babacu meal, soybean meal, cotton meal, cotton seed, corn gluten, corn gluten meal and soybean hull) were determined using sheep as experimental animals. Forages and concentrates feed were combined in two different levels, following a completely randomized design with four repetitions for each level. The same animals were utilized to the two concentrate levels, in two consecutive periods. The diets refering to the two concentrate levels were isonitrogenous. The corn silage, sugar cane with 1% urea, coastcross grass hay 1, coastcross grass hay 2, tifton grass haylage and elephant grass presented, respectively, the following TDN values: 59.56, 60.57, 48.59, 50.24, 60.49 and 49.59%. The concentrate feeds presented the following TDN values: corn grain ground (93.75%), sorghum grain ground (82.82%), corn germ (85.30%), wheat bran (74.28%), rice bran (80.65%), babacu meal (49.38%), soybean meal (83.24%), cotton meal (67.75%), cotton seed (88.07%), corn gluten (85.34%), corn gluten meal (75.61%) and soybean hull (68.95%). The equations system was efficient in determination of the energy value of feed, because the high correlation between those values and the digestibilities of dry matter and organic matter of all feeds evaluated.

Efeito do resfriamento do sêmen eqüino sobre sua congelabilidade

Two freezing protocols and two thawing methods were evaluated on 25 ejaculates from five stallions of the Mangalarga Marchador breed. In the first freezing method, semen was cooled to 5oC before freezing (CR); and in the second, semen at room temperature was frozen directly (SC). The two thawing methods were thawing semen at 37oC for 30 seconds versus thawing at 75oC for 7 seconds. Thawed semen was evaluated by the thermal resistance test (TRT- total motility and vigor) and by integrity of sperm membranes (the hypo-osmotic test and the eosine-nigrosine test). Semen that was cooled before freezing had higher (P<0.05) motility immediately post-thaw than semen that was more abruptly frozen (46.7% versus 21.0% for semen thawed at 37oC and 44.1% versus 24.5% for semen thawed at 75oC, respectively). At both thawing temperatures, the percentage of live spermatozoa was higher (P<0.05) in CR treatment than in the SC method (71% versus 54.6% for semen thawed at 37oC and 77.3% versus 54.1% for semen thawed at 75oC, respectively). The CR treatment also resulted in better hypo-osmotic test results and better semen vigor than did the SC treatment. Semen thawed at 75oC showed better (P<0.05) vigor than semen thawed at 37oC, independent of the semen freezing method. In conclusion, there were substantial benefits on subsequent semen quality from cooling of semen before it was frozen.

Perdas econômicas devidas à brucelose bovina no Brasil

Brucellosis is an important zoonosis of worldwide distribution. Reliable epidemiologic brucellosis data covering approximately 90% of the cattle population in Brazil have been recently published. Therefore, considering the scarcity of information regarding the economic impact of bovine brucellosis in Brazil, the goal of this study was to estimate economic impact of brucellosis on the Brazilian cattle industry. Several parameters including abortion and perinatal mortality rates, temporary infertility, replacement costs, mortality, veterinary costs, milk and meat losses were considered in the model. Bovine brucellosis in Brazil results in an estimated loss of R

Transcription of pattern recognition receptors and abortive agents induced chemokines in the bovine pregnant uterus.

420,12 or R

Ovarian steroids do not affect bovine endometrial cytokine or chemokine responses to Escherichia coli or LPS in vitro

226,47 for each individual dairy or beef infected female above 24 months of age, respectively. The total estimated losses in Brazil attributed to bovine brucellosis were estimated to be approximately R

Postpartum toll-like receptors and β-defensin 5 mRNA levels in the endometrium of Holstein cows.

892 million (equivalent to about 448 million American dollars). Every 1% increase or decrease in prevalence is expected to increase or decrease the economic burden of brucellosis in approximately 155 million Reais.

Use of complementary tests to evaluate the freezing ability of semen from goats under artificial photoperiod exposure

Pattern recognition receptors (PRRs) are important components of the innate immune system whose ligands are specific pathogen associated molecular patterns (PAMPs). Considering the scarcity of studies on transcription of PRRs in the pregnant uterus of cows, and its response to PAMPs and microorganisms that cause abortion in cattle, this study aimed to characterize the transcription of TLR1-10, NOD1, NOD2 and MD2 in bovine uterus throughout gestation and to investigate the sensitivity of different uterine tissues at third trimester of pregnancy to purified TLR ligands or heat-killed Brucella abortus, Salmonella enterica serotype Dublin (S. Dublin), Listeria monocytogenes, and Aspergillus fumigatus, by assessing chemokine transcription. RNA extracted from endometrium, placentome and intercotiledonary region of cows at the first (n=6), second (n=6), and third (n=6) trimesters of pregnancy were subjected to real time RT-PCR. After stimulation of endometrium and intercotiledonary regions with purified TLR ligands or heat-killed microorganisms, gene transcription was assessed by real time RT-PCR. In the placentome, there was no significant variation in TLRs transcription throughout the three trimesters of pregnancy. In the endometrium, there was significant variation in TLR4 and TLR5 transcription during the three stages of gestation; i.e. TLR4 transcription was higher during the third trimester, whereas TLR5 transcription was higher during the last two trimesters. In the intercotiledonary region, there was significant variation in transcription of TLR1/6, TLR7, and TLR8, which were more strongly expressed during the first trimester of pregnancy. At the third trimester of gestation, significant transcription of CXCL6 and CXCL8 was detected mostly in endometrial tissues in response to purified TLR4 and TLR2 ligands. Transcription of these chemokines was induced in the endometrium and intercotiledonary region at the third trimester of pregnancy when stimulated with heat-killed B. abortus or S. Dublin. Therefore, this study demonstrates that some PRRs are expressed in the uterus during pregnancy, which coincides with its ability to respond to stimulation with TLRs ligands as well as heat-killed organisms known to cause abortion in cattle.