ABSTRACT
The use of antimicrobials in the dairy production environment for mastitis control must take etiology, clinical signs, economic impacts, and regulatory frameworks into consideration. The objective of the present review is to highlight important aspects of the dynamics of antimicrobial use in dairy production and the potential impacts on the main pathogens circulating in this environment, considering the parameters set by the World Health Organization (WHO) regarding the priority of monitoring as well as control strategies for these agents, such as the methicillin-resistant Staphylococcus and the beta-lactamase-producing Escherichia coli. Understanding the animal-environment-pathogen triad is crucial for establishing control measures and preventing the spread of bacterial resistance. Implementing mastitis prevention and control measures in dairy farms, considering process flow and personnel qualification, enables a reduction in antimicrobial usage and contributes to prevent the spread of resistant bacterial agents in the dairy production environment, minimizing the relapses and the chronicity of the infectious process.
A utilização de antimicrobianos no controle de mastite em ambiente de produção leiteira deve considerer alguns aspectos como a etiologia, os sinais clínicos, os impactos económicos e a legislação. O objetivo da presente revisão é destacar aspectos importantes na dinâmica do uso de antimicrobianos na produção leiteira e os potenciais impactos sobre os principais patógenos circulantes neste ambiente, considerando os parâmetros estabelecidos pela Organização Mundial da Saúde (OMS) quanto à prioridade de monitoramento, bem como estratégias de controle para esses agentes, como o Staphylococcus resistente à meticilina e a Escherichia coli produtora de beta-lactamase. Compreender a tríade animal-ambiente-patógeno é crucial para estabelecer medidas de controle e prevenir a propagação da resistência bacteriana. A implementação de medidas de prevenção e controle de mastites nas propriedades leiteiras, considerando o fluxo do processo e a qualificação do pessoal, permite a redução do uso de antimicrobianos e contribui para prevenir a propagação de agentes bacterianos resistentes no ambiente de produção leiteira, minimizando as recidivas e a cronicidade do processo infeccioso.
ABSTRACT
Staphylococcus aureus antimicrobial resistance, especially to beta-lactams, favors treatment failures and its persistence in herd environment. This work aimed to develop a more specific primer for mecA gene detection based on the comparison of the conserved regions from distinct host origins and also investigated the presence of homologue mecA(LGA251) in bovine strains. A total of 43 Staphylococcus spp. were included in this study, comprising 38 bovine S. aureus, two human and three equine coagulase-negative staphylococci (CNS). Phenotypical methicillin-resistance detection was performed through oxacillin agar-screening and cefoxitin disk-diffusion test. None isolate tested positive for mecA(LGA251) gene. For mecA gene PCR, new primers were designed based on the sequences of human S. aureus (HE681097) and bovine S. sciuri (AY820253) mecA. The new primers based on the S. aureus mecA sequence amplified fragments of human and equine CNS and the ones based on S. sciuri mecA sequence only yielded fragments for S. aureus bovine strains. Multiples alignments of mecA gene sequences from bovine, human and equine revealed punctual but significant differences in bovine strains that can lead to the mecA gene detection impairment. The observed divergences of mecA gene sequences are not a matter of animal or human origin, it is a specificity of bovine samples.
Subject(s)
Bacterial Proteins/genetics , Staphylococcal Infections/microbiology , Staphylococcal Infections/veterinary , Staphylococcus aureus/genetics , Staphylococcus aureus/isolation & purification , Animals , Cattle , DNA Primers/genetics , DNA, Bacterial/genetics , Genetic Variation , Horses , Humans , Methicillin Resistance , Microbial Sensitivity Tests , Penicillin-Binding Proteins , Polymerase Chain Reaction/methods , Sequence Alignment , Sequence Homology, Nucleic AcidABSTRACT
Staphylococcus aureus antimicrobial resistance, especially to beta-lactams, favors treatment failures and its persistence in herd environment. This work aimed to develop a more specific primer for mecA gene detection based on the comparison of the conserved regions from distinct host origins and also investigated the presence of homologue mecA LGA251 in bovine strains. A total of 43 Staphylococcus spp. were included in this study, comprising 38 bovine S. aureus, two human and three equine coagulase-negative staphylococci (CNS). Phenotypical methicillin-resistance detection was performed through oxacillin agar-screening and cefoxitin disk-diffusion test. None isolate tested positive for mecA LGA251 gene. For mecA gene PCR, new primers were designed based on the sequences of human S. aureus (HE681097) and bovine S. sciuri (AY820253) mecA. The new primers based on the S. aureus mecA sequence amplified fragments of human and equine CNS and the ones based on S. sciuri mecA sequence only yielded fragments for S. aureus bovine strains. Multiples alignments of mecA gene sequences from bovine, human and equine revealed punctual but significant differences in bovine strains that can lead to the mecA gene detection impairment. The observed divergences of mecA gene sequences are not a matter of animal or human origin, it is a specificity of bovine samples.
