The Role of Transplacental Infection in Leptospira spp. Epidemiology in Cattle in Caatinga Biome, Brazil.

Leptospirosis is an infectious disease that affects domestic animals, wild animals, and humans. It represents a public health problem and has an important economic impact on livestock. This study aims to investigate the importance of genital and transplacental infection in the epidemiology of leptospirosis in cows maintained in Caatinga biome conditions, Northeastern Brazil, as well as reporting organs colonized by Leptospira spp. in embryos and fetuses. Blood, urinary tract (urine, bladder, and kidney), and reproductive tract (vaginal fluid, uterus, uterine tube, ovary, and placenta) samples were collected from 15 slaughtered pregnant cows. Two embryos and 13 fetuses were sampled. Central nervous system and choroid ovoid samples were collected from embryos. Blood, central nervous system, lung, peritoneal liquid, abomasal content, liver, spleen, urine, bladder, kidney, and reproductive system samples were collected from fetuses. Diagnostic methods included the microscopic agglutination test (MAT) using a collection of 24 serovars belonging to 17 different pathogenic serogroups of five species as antigens, as well as polymerase chain reaction (PCR). Anti-Leptospira spp. antibodies were found in 9 cows (60%), while 13 cows (86.67%) had at least one organ or urine with leptospiral DNA. No fetus was seroreactive. Among the embryos and fetuses, 13 (86.67%) presented leptospiral DNA, proving a high frequency of transplacental infection (100%). For cows, the most frequent biological materials regarding Leptospira spp. DNA detection were placenta (13 out of 15 samples; 86.7%), uterus (10 out of 15 samples; 66.7%), and vaginal fluid (5 out of 15 samples; 33.3%), while, for fetuses/embryos, the most frequent PCR-positive samples were choroid ovoid (1/2; 50%), spleen (6/13; 46.2%), kidney (5/13; 38.5%), and central nervous system (5/15; 33.3%). Sequenced samples based on the LipL32 gene presented 99% similarity with L. borgpetersenii. The results indicate that transplacental infection is an efficient way of spreading Leptospira spp. in cows maintained in Caatinga biome conditions. Therefore, prevention and control strategies must include actions that interrupt transmission through this alternative route.

Antibody detection and molecular analysis for Mycobacterium avium subspecies paratuberculosis (MAP) in goat milk: Systematic review and meta-analysis.

Paratuberculosis is an incurable infectious disease that affects several species, including goat (Capra hircus). The etiologic agent is Mycobacterium avium subspecies paratuberculosis (MAP) that has tropism for the intestine, causing anorexia, progressive weight loss and death. In goats, the main transmission route is the ingestion of water and food contaminated by infected feces. Affected animals also eliminate the agent through milk, with a potential biological risk to public health. Thus, the aim of this study was to conduct a research of the literature available in electronic media for a systematic review, followed by a meta-analysis of the results found on prevalence and diagnostic tests adopted in the detection of MAP antibodies and DNA in goat milk. The following search parameters were used: "Mycobacterium avium subsp. paratuberculosis" AND (goat OR small ruminant) AND (milk OR pasteurized milk). Strictly obeying pre-established criteria, 437 articles were selected from the respective electronic databases of scientific content: ScienceDirect (285), PubMed (68), Web of Science (60) and Scopus (24), of which nine papers were elected to the construction of the systematic review and meta-analysis. The prevalence of MAP antibodies in milk detected by milk-ELISA ranged from 1.1 to 67.7% and the prevalence of MAP DNA in goat milk detected by MAP-specific polymerase chain reaction (PCR) ranged from 1.94 to 37.74%. A meta-analysis indicated a combined MAP infection prevalence of 8.24%, but with high heterogeneity among study findings (I2 = 98.7%). The identification of the MAP in goat milk implies the need for surveillance of the agent in order to prevent economic losses and impact on public health.

Leptospira sp. vertical transmission in ewes maintained in semiarid conditions.

Leptospirosis is a globally distributed disease associated with reproductive failures in livestock; however, its pathogenesis has not been fully elucidated. Results from the present study indicate there is a presence of Leptospira sp. in organs and fluids of fetuses from ewes slaughtered in the semiarid region of Brazil. Twenty-nine fetuses from 23 ewes determined to be Leptospira sp.-positive using PCR were sampled (14 and 15 in dry and rainy seasons, respectively). Fetal samples of blood, central nervous system (CNS), lung, liver, spleen, stomach contents, peritoneal fluid, kidney, bladder, urine and reproductive system were collected. Diagnostic methods included the microscopic agglutination test (MAT), polymerase chain reaction (PCR) and bacterial isolation. Of the 29 fetuses, 24 (82.8 %) had at least one Leptospira sp.-positive organ or fluid, as determined using PCR, and of a total of 209 samples, 62 (29.7 %) contained leptospiral DNA. Of the 99 samples collected during the dry season, 42 (42.4 %) were positive, and of 110 samples collected during the rainy season, 20 (18.2 %) were positive (P = 0.0001). There was deoxyribonucleic acid (DNA) sequencing of three samples of kidney, CNS and liver, and in all of these, there was 99.3 % similarity with Leptospira interrogans. Leptospires were present in cultures of pooled samples from fetuses with deformities. Results indicate there is vertical (maternal-to-fetus) transmission which would represent an alternative transmission route for the spread of Leptospira sp. in ewes, suggesting molecular detection is essential in the investigation of leptospirosis in fetuses to identify animals that have been infected with this bacterium.