New insights on Leptospira sp. infection in ewes maintained in field semiarid conditions.

Leptospirosis is poorly studied in small ruminants raised in field semiarid conditions. In this study we compared serological, bacteriological and molecular diagnostic methods in ewes maintained in field Brazilian semiarid conditions. Blood, vaginal fluid and urine samples were collected from 60 Morada Nova ewes raised in a semi-intensive system in the Brazilian semiarid. Diagnostic tests performed were microscopic agglutination test (MAT), polymerase chain reaction (PCR) and bacterial isolation. Anti-Leptospira sp. antibodies were found in eight (13.33%) animals analyzed by MAT at reciprocal titer 25 (cut-off 25), while Leptospira sp. DNA was detected in urine or vaginal fluid of 56 animals (93.33%). There was growth of leptospires in 10 urine cultures and in 11 vaginal fluid cultures, however, two of urine (2/60-3.33%) and eight cultures of vaginal fluid (8/60-13.33%) were confirmed by PCR. Two samples of vaginal fluid (one of each animal) were submitted to sequencing demonstrating 99% similarity with L. santarosai and L. interrogans. The highest MAT sensitivities were obtained with reciprocal titer 25 (cut-off 25) compared to 50 and 100. The performance of different diagnostic techniques for leptospirosis in ewes raised in field semiarid conditions allowed a better evaluation of the herd, as well as made it possible to identify carrier animals. Genital route may be important for efficient transmission and without dependence on environmental factors in ewes from semiarid, as well as it's highlighted that titer 1:25 in serology was more efficient, indicating its use in ewes in field semiarid conditions.

Avaliação de resíduo de antibiótico em amostras de leite de vacas após a terapia de vacas secas / Evaluation of antibiotic residues in milk samples from cows after dry cow therapy

Neste trabalho objetivou-se avaliar a presença de resíduos de antimicrobianos no leite de animais tratados no período pré-parto. Foram utilizados 47 animais de propriedades leiteiras, oriundas do estado de Rondônia, para tratamentos com antibióticos comerciais antimastíticos específicos para uso em período seco (cloxacilinabenzatina e espiramicina em associação com neomicina) e em lactação (cloridrato de ceftiofur) aos 60 e 30 dias pré-parto, respectivamente, em uma única aplicação. As análises para detecção de resíduos de antimicrobianos foram realizadas com um teste microbiológico comercial Eclipse 50 (ZEU-Inmunotec®, Zaragoza). Foi constatada a presença desses em 3,44% dos animais tratados com cloxacilina, em 12,50% dos animais tratados com espiramicina associada à neomicina e em 10% dos animais que receberam cloridrato de ceftiofur. O período para o aproveitamento do leite após a terapia de vacas secas com antibióticos mais indicado foi de 30 dias para antibióticos usados durante a lactação e de 60 dias para tratamento de vacas secas. A ocorrência dos resíduos de antibióticos no leite é um risco para a saúde pública e para a contaminação de produtos lácteos.(AU)

The present study aimed to assess antibiotic residues in milk from animals treated in the pre-term period. A total of 47 animals from dairy farms in Rondônia, Brazil, were used for treatment with commercially available antibiotics especific to the dry period (cloxacillinbenzathine and spiramycin associated to neomycin) and during the lactation period (ceftiofur hydrochloride) at 60 and 30 days after delivery, respectively, in a single application. The detection of antimicrobial residues was performed using the commercial microbiologic kit Eclipse 50 (ZEU-Inmunotec®, Zaragoza). The results showed antibiotic residues in 3.44% of animals treated with cloxacillinbenzathine, in 12.50% of animals treated with spiramycin/neomycin, and in 10% of animals treated with ceftiofur hydrochloride. The period indicated for milk consumption after therapy was 30 days for lactation antibiotic products and 60 days for dry cow therapy. The occurrence of the antibiotic residues in milk is a risk to public health and for the contamination of milk products.(AU)