The present study was carried out in 11 dairy herds in four municipal districts of the rural area of the State of Pernambuco, Brazil. Out of 984 quarter milk (246 cows), 10 (1.0%) were positive for clinical mastitis, 562 (57.1%) for subclinical mastitis and 412 (41.9%) were negative. A total of 81 Staphylococcus spp. isolates were obtained from milk samples from the cows diagnosed with subclinical mastitis. From these, 53 (65.0%) were S. aureus, 16 (20.0%) coagulase-positive staphylococci (CPS) and 12 (15.0%) coagulase-negative staphylococci (CNS). The isolates were further investigated for the presence of toxin genes by multiplex and uniplex PCR. The main gene observed was seg followed by seh, sei and sej. The distribution of these observed genes among the isolates obtained from different areas showed a regional pattern for the SEs. The presence of toxin genes in the strains isolated from bovine milk demonstrates a potential problem for public health.

Due to their mass production and intense consumption in human medicine, veterinary, and aquaculture, antibiotics have been widely detected in different ecosystems, leading to a growing worldwide concern. These and their byproducts are being continuously discarded in natural ecosystems via excretion of human and animal urine and feces, also domestic and hospital effluents. Residues of these drugs can persist in natural environments through bioaccumulation due to their difficult biodegradation. Also, they have a gradual deposition in sediments, aquatic surfaces, and groundwater. Studies have shown the presence of these drugs in aquatic environments, which can trigger severe changes in the composition and structure of the bacterial community, such as the ability to develop and propagate genes resistant to these pollutants. In this context, this review aims to address the effects of the antibiotics on microorganisms present in impacted aquatic environments.

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Infectious bovine mastitis is an infection of mammary gland responsible great losses to dairy farming, resulting in negative impacts on the quantity and quality of milk produced. Genetic factors may be related to resistance or intensification of the inflammatory condition. Among them, the bovine myeloid antimicrobial peptide 28 gene (Bmap-28) and the natural resistance associated macrophage protein 1 gene (Nramp1) stand out because they can be used as genetic markers in dairy cattle breeding programs. The aim of this study was to analyze the immunogenetic profile in herds from the dairy basin of the state of Pernambuco in Northeastern Brazil, using these markers previously established in the literature. For this, the partial sequencing of the genes Bmap-28 and Nramp1 was performed. The study covered 54 animals, regardless of sex or age. For Bmap-28, two genotypes were found, GG (76%) and GC (24%). Both profiles are considered susceptible to intramammary infection. On the other hand, Nramp1 immunogenotyping revealed three distinct profiles, GG (11%), GC (48%) and CC (41%), of which only the GG genotype configures resistance to mastitis. The immunogenetic scenario detected suggests that the local herd is prone to intramammary infection, which is corroborated by the high prevalence (65.2%) of mastitis in the Agreste region of Pernambuco State.