In vivo evaluation of the antiretroviral activity of Melia azedarach against small ruminant lentiviruses in goat colostrum and milk.

This study aimed to evaluate in vivo the use of the extract from the leaves of Melia azedarach in the ethyl acetate fraction at a concentration of 150 µg/mL as an antiretroviral treatment against small ruminant lentiviruses (SRLV) in goat colostrum, and milk with a 90-min action. Two groups of six kids were treated with the extract. One group received three supplies of colostrum from does naturally positive for SRLV, treated with the ethyl acetate fraction of M. azedarach (EAF-MA) for three days, while the other group consumed milk from does also carrying the virus with the respective extract twice a day for five days. After undergoing treatment, all animals began to receive thermized milk until weaning (60 days) and were monitored for six months using nested polymerase chain reaction (nPCR) and western blot (WB) tests. The study revealed cumulative percentages of positive animals in WB or nPCR in the milk group of 66.66% on the seventh day, 83.33% in the following week, and 100% at 120 days, while the colostrum group showed values of 66.66% at 14 days, 83.33% at 90 days, and 100% at 120 days. Variation and intermittency were observed in viral detection, but all animals tested positive in WB or nPCR at some point. A potential delay in infection was observed, which was more significant in the colostrum group. The need for the combination of serological and molecular tests for a more efficient detection of the disease is also emphasized.

Detection and isolation of small ruminant lentivirus in the amniotic fluid of goats.

The objective of this study was to verify the presence of small ruminant lentivirus in the amniotic fluid of goats using molecular tests and viral isolation by cocultivation in the amniotic fluid of naturally infected goats. The study analyzed eight goats: seven were small ruminant lentivirus-positive and one was negative. The amniotic fluid was collected from each of the eight animals during cesarean section at 147 days of pregnancy. Cocultivation was undertaken using secondary goat nictitating membrane cell cultures obtained by explant from a small ruminant lentivirus-negative calf followed by trypsinization and sub-cultivation of the cells for 63 days. During this period, five supernatant collections were performed for DNA extraction and subsequent nested polymerase chain reaction. DNA was extracted from the amniotic fluid after 3 h of cellular sedimentation, from which a sample of 600 µL was taken from the sediment and another 600 µL sample from the supernatant. After DNA extraction, nested polymerase chain reaction was performed. Of the eight goats, 62.5 % (05/08) were small ruminant lentivirus-positive, with 43.75 % (07/16) of the total samples positive when considering the two repetitions (supernatant and cell sediment). Moreover, positivity was confirmed by small ruminant lentivirus pro-viral DNA amplification in the cell supernatant throughout the cocultivation period. Small ruminant lentivirus were present in the amniotic fluid samples from the naturally infected goats indicating an intrauterine transmission route. Moreover, this biological fluid can be adopted for the diagnosis of these lentiviruse because it is an important risk factor related to intrauterine transmission.

Influência da progesterona injetável na taxa de prenhez e perda gestacional de fêmeas nelore de distintas categorias reprodutivas submetidas a inseminação artificial em tempo fixo / Influence of injectable progesterone on the pregnancy rate and gestational loss of Nellore females of different reproductive categories undergoing fixed-time artificial insemination

Progesterone (P4) is essential for embryonic development and maintenance of pregnancy when deficiency causes early embryonic loss. In this study, we investigated the ability of hormonal supplementation to improve the fertility of Nellore females subjected to fixed-time artificial insemination (IATF) protocols. Here, we evaluated the effect of long-acting injectable progesterone (iP4) supplementation in the D4 after IATF on pregnancy rate and pregnancy loss in Nellore females (Bos taurus indicus) from different reproductive categories in Western Amazonia. Eight hundred thirteen Nellore females from 5 farms were selected and distributed into 2 groups: control [GC; administration of 0.5 mL of 0.9% saline solution, intramuscularly - IM] (n = 407) and a group that received injectable progesterone (iP4) that was long-acting [GiP4; administration of 0.5 mL of iP4, 300 mg, via IM four days after IATF] (n = 406). Each group contained 3 subgroups: heifers, primiparous cows, and multiparous cows. Of the 407 animals in the CG, 103 were heifers, 107 primiparous, and 197 multiparous. Of the 406 animals in the GiP4 group, there were 101 heifers, 107 primiparous, and 198 multiparous. On a random day of the estrous cycle (D0), an intravaginal device containing 1 g of P4 and 2 mg of estradiol benzoate (BE) was inserted by intramuscular injection. On D8, the P4 device was removed and 150 µg of D-cloprostenol (PGF2α), 300 IU eCG, and 1 mg BE were administered IM. Cows were inseminated at D10, 48-52 h after procedure on D8. Pregnancy diagnosis was made between 35 and 40 days after insemination through ultrasound examination. Between 80 and 90 days after insemination, a new ultrasound examination was performed to assess early pregnancy loss. The data were processed using the SAS 9.2. The conception rate, pregnancy loss, and final conception rate were analyzed using PROC GLIMMIX according to groups (CG and GiP4), categories (heifers, primiparous and multiparous), and their interactions as variables. The differences in the means of least squares were adjusted using the Tukey­Kramer method. Statistical significance was defined as P < 0.05. The general conception rate was 46% (375/816). Regardless of the animal class, GiP4 animals (51.97%) had higher conception rates (P < 0.05) than CG (40.29%). In the subgroups (heifers, primiparous and multiparous cows), there was a difference (P < 0.05) between animals treated with iP4 (52.48%, 57.94%, and 48.48%, respectively) and those who were not (39.81%, 41.12%, and 40.10%, respectively). Gestational losses, regardless of the animal class, were higher in females in the CG (7.93%) [P < 0.05] compared to those in the GiP4 group (2.84%). Regardless of treatment with iP4, the percentage of gestational loss in heifers was significantly higher (10.64%) than that in primiparous and multiparous cows (3.77% and 2.86%, respectively). The final conception rates were higher in animals that received long-acting iP4, which increased the final pregnancy in all parity categories. In the present study, the use of iP4 increased the pregnancy rate in Nellore females, regardless of the category. Although there has been no consensus on the use of iP4, there is an agreement that increases in the pregnancy rate are related to the moment of exogenous P4 application. In addition to influencing the pregnancy rate, reduction in pregnancy losses is also attributed to iP4 treatment, a fact demonstrated in the present study, where animals treated with iP4 had a lower pregnancy loss rate than normally occurs in beef cattle. Supplementation with long-acting iP4 increased the pregnancy rate at D35-40, reduced pregnancy losses, and increased the conception rate on D80-90 days in Nellore females reared in the Western Amazon, regardless of the animal category.(AU)

Vertical transmissibility of small ruminant lentivirus.

This study aimed to evaluate by means of Nested Polymerase Chain Reaction (nPCR), co-cultivation and sequencing, with genetic comparison between strains (mother/newborn), the occurrence of vertical transmission of Small Ruminant Lentiviruses (SRLV) from naturally occurring nannies infected for their offspring. For the detection of SRLV seropositive progenitors, blood was collected from 42 nannies in the final third of gestation in tubes with and without anticoagulant. The diagnostic tests used were Western Blot (WB) and nPCR. During the period of birth, the same blood collection procedure was performed on 73 newborns at zero hours of birth, with the same diagnostic tests. Seventeen blood samples from seven-day-old kids, proven positive for SRLV by nPCR, chosen at random, were subjected to coculture in goat synovial membrane (GSM) cells for 105 days. The pro-viral DNA extracted from the cell supernatant from the coculture was subjected to nPCR. For DNA sequencing from the nPCR products, nine positive samples were chosen at random, four nannies with their respective offspring, also positive. Each sample was performed in triplicate, thus generating 27 nPCR products of which only 19 were suitable for analysis. Among the 42 pregnant goats, in 50% (21/42) pro-viral DNA was detected by nPCR, while in the WB, only 7.14% (3/42) presented antibodies against SRLV. Regarding neonates, of the 73 kids, 34 (46.57%) were positive for the virus, using the nPCR technique, while in the serological test (WB), three positive animals (4.10%) were observed. The coculture of the 17 samples with a positive result in the nPCR was confirmed in viral isolation by amplification of the SRLV pro-viral DNA. When aligned, the pro-viral DNA sequences (nannies and their respective offspring) presented homology in relation to the standard strain CAEV Co. It was concluded that the transmission of SRLV through intrauterine route was potentially the source of infection in the newborn goats.

Seroprevalence and associated risk factors of Mycoplasma agalactiae and investigation of coinfection with the caprine lentivirus in Rio Grande do Norte, Brazil.

Contagious agalactia is a disease caused by Mycoplasma agalactiae that leads to a reduction or complete stop of milk production. Caprine arthritis encephalitis (CAE) is an infectious disease caused by a lentivirus of the Retroviridae family, member of the small ruminant lentivirus (SRLV) group. Although these diseases are caused by distinct pathogens, the clinical presentation is similar. Hence, this study aimed to perform a serological investigation, as well as to assess correlation between both diseases and risk factors associated in two mesoregions of Rio Grande do Norte, Brazil. Enzyme-linked immunosorbent assay (ELISA) was used for contagious agalactia and western blot for CAE. A total of 538 serum samples were used in this study that were collected from goats and sorted from a blood bank of the Brazilian Agricultural Research Corporation. Seroprevalence of M. agalactiae in flocks from Rio Grande do Norte was 7.8% (42/538). In both regions that were investigated, 25.9% (14/54) of farms had positive animals. CAE results revealed that 3.9% (21/538) of animals and 42.6% (23/54) of farms had this disease. Concerning risk factors, only sex and animal category presented significant relevance (P < 0.05) for contagious agalactia, in which females presented higher frequency of seropositive individuals (10.1%; 39/387). In the animal category, 4.3% (14/326) and 11.1% (36/323) of female breeders were positive for CAE and contagious agalactia, respectively, and significance was identified only in the latter (P < 0.05). In conclusion, there was no correlation between the investigated diseases, considering that no animal demonstrated antibodies for both pathogens.

Sodium dodecyl sulfate as a viral inactivator and future perspectives in the control of small ruminant lentiviruses / Emprego do dodecil sulfato de sódio como inativador viral e suas perspectivas no controle de lentivírus de pequenos ruminantes

Infections by small ruminant lentiviruses (SRLVs) affect goats and sheep causing chronic multisystemic diseases that generate great economic losses. The caprine lentivirus (CLV) and the ovine lentivirus (OLV) present tropism for cells of the monocyte/macrophage lineage, which are directly associated with the main route of transmission through the ingestion of milk and colostrum from infected animals. In this manner, controlling this route is of paramount importance. Currently, researches have investigated the use of chemical additives in milk that can preserve colostrum or milk and inactivate microbiological agents. Among the compounds, sodium dodecyl sulfate (SDS) has been shown to be satisfactory in the chemical inactivation of HIV and CLV in milk, and also as a biocide in goat colostrum.(AU)

As lentiviroses de pequenos ruminantes (LVPRs) são infecções que afetam caprinos e ovinos, causando doenças multissistêmicas crônicas, ocasionando grandes perdas econômicas. Os agentes causadores, lentivírus caprino (LVC) e o lentivírus ovino (LVO), apresentam tropismo por células da linhagem monocítico--fagocitária, as quais estão diretamente associadas à principal via de transmissão, por meio da ingestão de leite e colostro provindos de animais infectados. Desse modo, o controle por esta via é de suma importância. Atualmente, pesquisas vêm sendo desenvolvidas para o uso de aditivos químicos no leite, que possam conservar o colostro ou leite, e inativar agentes microbiológicos presentes. Dentre estes, o dodecil sulfato de sódio (SDS) vem apresentando resultados satisfatórios na inativação química do HIV e LVC em leite, e ainda como biocida em colostro caprino.(AU)

Small ruminant lentiviruses: economic and productive losses, consequences of the disease / Lentiviroses de pequenos ruminantes: perdas produtivas e econômicas, consequências da doença

Small ruminant lentiviruses, caprine arthritis encephalitis virus, and Maedi-Visna virus cause diseases that result in significant productive losses, mostly in dairy animals. These viruses belong to the Retroviridae family, Lentivirus genus, and constitute a heterogeneous group, which may generate implications for the diagnosis and control of small ruminant lentiviruses. Losses caused by them are associated with reproductive failure, short productive life, and decreased milk production by the infected animals. In addition, these viruses may reduce milk quality, affecting the production of dairy products such as cheese. Small ruminant lentiviruses lead to indirect losses, decreasing herd value and forcing the development of epidemiological trade barriers for animal germplasm. Control of small ruminant lentiviruses is important to promote optimal milk production and to reduce costs with medicine and technical assistance. This control may vary in caprine and ovine populations of each country, according to seroprevalence, variety of breeds, and peculiarities of the practiced management.(AU)

Os lentivírus de pequenos ruminantes, o vírus da artrite encefalite caprina e o vírus Maedi-Visna causam enfermidades que ocasionam perdas produtivas significativas, principalmente em animais com aptidão leiteira. Esses vírus pertencem à família Retroviridae e ao gênero Lentivirus e formam um grupo genético heterogêneo, o que pode ocasionar implicações para o diagnóstico e o controle dos lentivírus de pequenos ruminantes. As perdas causadas pelos lentivírus de pequenos ruminantes estão relacionadas com falhas reprodutivas, vida produtiva curta e diminuição da produção leiteira dos animais infectados. Além disso, esses vírus podem promover a redução da qualidade do leite, afetando a produção de laticínios, tal como o queijo. Os lentivírus de pequenos ruminantes levam a perdas indiretas, reduzindo o valor dos rebanhos e forçando o desenvolvimento de barreiras comerciais epidemiológicas para germoplasma animal. O controle dos lentivírus de pequenos ruminantes é importante para promover uma maior produção de leite e reduzir os custos com medicamentos e assistência técnica. Esse controle pode variar de acordo com a população caprina e ovina de cada país em termos de soroprevalência, variedade de raças e particularidades do manejo adotado.(AU)