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Coagulase-negative staphylococci (CNS) are among the main responsible agents for mastitis in sheep. Cure rates can be reduced due to several causes, such as those related to virulence factors presented by microorganisms. This study aims at characterizing the virulence and resistance factors to antimicrobial agents in different CNS species isolated from sheep milk. After collecting milk samples, the samples were analyzed and the CNS species were identified. After identification, the susceptibility-sensitivity profile was examined using the disk diffusion technique for 10 antimicrobial agents. The DNA was extracted to detect the presence of the mecA gene, biofilm (icaADBC, bap, and bhp) and toxin genes (sea, seb, sec, sed, tst, and luk-PV) by PCR. Samples carrying toxin genes had their expression assessed using the reverse-transcription PCR technique. The biofilm production was assessed using the adherence method on a polystyrene plate. One hundred twelve CNS samples were isolated, 53 (47.3%) from animals with subclinical mastitis and 59 (52.7%) from healthy animals. Drugs tested have shown to be efficient for most CNS samples. The largest resistance percentage of CNS was found for the penicillin (17.0%) and tetracycline (10.7%) and 4 samples carried the mecA gene. As for the biofilm genes, the icaADBC operon was found in 10 (8.9%) samples, the bap gene was found in 16 (14.3%), and the bhp gene was found in 3 (2.7%). In addition, 69 (61.6%) samples produced biofilm. The survey of toxin genes has shown that 70 (62.5%) samples showed some toxin-encoding gene. However, none of the samples has expressed any of the genes from those toxins studied.

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Although hemoplasma infection in domestic animals has been well documented, little is known about the prevalence and genetic diversity of these bacteria in wild rodents. The present work aimed to investigate the occurrence of hemotrophic mycoplasmas in wild rodents from five Brazilian biomes, assessing the 16S rRNA phylogenetic position of hemoplasma species by molecular approach. Spleen tissues were obtained from 500 rodents, comprising 52 different rodent species trapped between 2000 and 2011. DNA samples were submitted to previously described PCR protocols for amplifying Mycoplasma spp. based on 16S rRNA, followed by sequencing and phylogenetic inferences. Among 457 rodent spleen samples showing absence of inhibitors, 100 (21.9%) were PCR positive to Mycoplasma spp. The occurrence of hemotropic mycoplasmas among all sampled rodents was demonstrated in all five biomes and ranged from 9.3% (7/75) to 26.2% (38/145). The Blastn analysis showed that amplified sequences had a percentage of identity ranging from 86 to 99% with other murine hemoplasmas. The ML phylogenetic analysis of 16S rRNA gene of 24 positive randomly selected samples showed the presence of ten distinct groups, all clustering within the Mycoplasma haemofelis. The phylogenetic assessment suggests the circulation of novel hemoplasma species in rodents from different biomes in Brazil.

No abstract

The objective of this study was to characterize the clonal profile, virulence factors and antimicrobial resistance, particularly oxacillin resistance, of Staphylococcus aureus isolated from sheep milk. Milk samples were collected from all teats for the California Mastitis Test (CMT), somatic cell count, identification of S. aureus, investigation in these strains of genes encoding toxins (sea, seb, sec, sed, tst), biofilm (icaA, icaC, icaD, bap), leukocidin (luk-PV) oxacillin resistance by mecA gene detection and susceptibility testing (12 antibiotics). Messenger RNA expression was evaluated by RT-PCR in isolates carrying toxin and biofilm genes. Biofilm formation was also evaluated phenotypically by adherence to polystyrene plates. The clonal profile of S. aureus was investigated by pulsed-field gel electrophoresis. A total of 473 milk samples were collected from 242 animals on three farms and 20 S. aureus strains were isolated and none carried the mecA gene. The two sec gene-positive isolates and the isolates carrying the tst and luk-PV genes were positive by RT-PCR. Staphylococcus aureus isolated from the three flocks studied showed high susceptibility to the drugs tested and none was biofilm producer, indicating that biofilm formation was not a virulence factor causing infection by these strains. The typing of 17 S. aureus isolates revealed the presence of a common clone on the three farms studied, and the presence and expression of the sec and tst genes in one strain of this clone suggest the possible acquisition of virulence genes by this clone, a fact that is important for animal health and food hygiene.

RESUMOO objetivo deste estudo foi verificar a influência do colostro nos parâmetros bioquímicos séricos em cordeiros recém-nascidos. Foram colhidas amostras sanguíneas de 28 cordeiros, determinando-se os indicadores proteicos, energéticos, de função renal, bilirrubinas e as enzimas aspartato aminotransferase (AST), gamaglutamiltransferase (GGT) e creatina quinase (CK), nos momentos pré e pós-colostro. Os dados foram analisados comparando-se a variabilidade dos parâmetros entre os dois momentos. Houve elevação (P<0,001) das concentrações de proteínas totais, em resposta ao forte aumento (P<0,01) dos teores de globulinas totais e ao leve decréscimo (P<0,05) da concentração de albumina, após a ingestão colostral. Também foram observados maiores valores de bilirrubinas total e direta (P<0,001), e variação dos metabólitos renais, com elevação dos níveis de ureia (P<0,01) concomitante à redução dos valores de creatinina (P<0,001), no momento pós-colostro. Houve aumento (P<0,001) da glicemia, de colesterol total e triglicerídeos, bem como das atividades enzimáticas (P<0,001) de AST e GGT, entre os momentos avaliados. Conclui-se que a dinâmica do perfil bioquímico em cordeiros recém-nascidos sofre o efeito da ingestão de colostro e da adaptação das funções fisiológicas à vida extra-uterina. Os valores dos parâmetros variam marcadamente no período pós-natal, sendo recomendável a utilização de valores de referência próprios para esta fase. PALAVRAS-CHAVE: amamentação, bioquímica clínica, neonato, ovino, sangue. PRE AND POST-COLOSTRAL DYNAMICS OF BIOCHEMICAL PARAMETERS IN LAMBS ABSTRACTThis study aimed to verify the influence of colostrum in serum biochemical parameters in newborn lambs. Blood samples were taken of 28 lambs, determining the protein, energy and kidney function indicators, bilirrubins and the enzymes aspartate aminotransferase (AST), gammaglutamyl transferase (GGT) and creatine kinase (CK), in pre and post-colostrum moments. The data were analyzed comparing the variability of the parameters between the two moments. There was an elevation (P<0.001) in total protein concentrations, in response to substantial increase (P<0.01) in total globulin levels, and a slight decrease (P<0.05) in albumin concentration, after colostral intake. We also observed higher values of total and conjugated bilirubins (P<0.001), and variation of kidney metabolites, with an elevation of urea levels (P<0.01) concomitant to decrease of creatinine values (P<0.001) in the postcolostrum moment. There was an increase (P<0.001) in glycemia, total cholesterol and triglycerides, as well as of

The objective of this study was to evaluate the carcass and meat traits, and the non-carcass components of crossbred Dorper lambs fed diets with increasing levels of urea (0.0, 0.5, 1.0, and 1.5% of dry matter – DM). The experimental design was completely randomized with four treatments (urea inclusion levels) and six replicates per treatment. Lambs were fed ad libitum for 56 days and slaughtered at 37.9 ± 5.1 kg of body weight (BW). The weight and yield of carcass before and after cooling were not influenced by urea levels, with average values of 16.9 kg and 44.6% for cold carcass weight and yield. Urea levels did not affect the morphometric measurements, the fat deposition on the carcass, the weight of carcass cuts and the weight of non-carcass components. There was a quadratic effect of urea levels on the loin yield, which may achieve maximum value of 11.31% with the inclusion of 0.84% DM urea in the feed. The pH and the color coordinates L* (brightness), a* (red intensity) and C* (saturation) of the meat also showed quadratic response to the urea levels, where in the minimum value of 5.53 for pH, maximum value of 48.67 for L* and minimum values of 14.04 and 16.21 for a* and C* may be obtained by including 0.53 to 0.70% DM urea in the ration. The inclusion of 0.84% DM urea in the ration is recommended to obtain maximum yield of loin and meat with attractive characteristics to the consumer, which is characterized by high red intensity and brightness. If consumers have preference for lamb meat with a more intense red color, the inclusion of 1.5% DM urea should be considered in the ration formulation.