Estudo bacteriológico do complexo de doenças respiratórias em bezerros (CDRB) leiteiros do estado do Maranhão

Abstract

This work aimed to carry out the bacteriological study of the bacterial agents involved in the complex of respiratory diseases of calves (CDRB) in the state of Maranhão. A total of 550 calves, distributed among 29 herds, were evaluated, obtaining a total of 45 samples of animals with a clinical picture suggestive of CDRB, representing a frequency of 8.18% (n=45). The frequency of positive herds was 44.82% (n=13) and that of municipalities was 63.63% (n=7). Samples were collected by nasal swab and were cultured on blood agar and MacConkey agar plates. Of the 45 samples, 37 showed bacterial growth on plates. From the cultivated colonies, Gram staining, biochemical tests and antibiogram were performed. The bacteria Mannheimia haemolytica 24.32% (n=9), Pasteurella multocida 18.91% (n=7), Histophilus somni 2.70% (n=1), Actinobacillus pleuropneumoniae 2.70% (n=1), Yersinia sp. 5.40% (n=2), Corynebacterium sp. 5.40% (n=2), Moraxella bovis 21.62% (n=8), Pseudomonas aeruginosa 2.7% (n=1), Staphylococcus sp. % (n=4), Streptococcus sp. 2.70% (n=1), and Arcanobacterium sp. 2.70% (n=1). In the antibiogram, all isolates showed sensitivity to amoxicillin + clavulanic acid (30 μcg), amoxicillin (10 μcg), erythromycin (15 μcg), ceftiofur (30 μcg) and tetracycline (30 μcg) 100% (n=37). The herds visited were georeferenced and the positive animals came from the following municipalities: São João do Caru, Itapecuru- Mirim, Araioses, Bernardo do Mearim, Lima Campos, Igarapé Grande and Poção de Pedra. Thus, it was concluded that CDRB is present in dairy herds in the state of Maranhão and the following bacteria were isolated: Mannheimia haemolytica, Pasteurella multocida., Histophilus somni, Actinobacillus pleuropneumoniae, Corynebacterium sp., Moraxella bovis, Yersínia sp., Pseudomonas aeroginosa, Staphylococcus sp., Streptococcus sp. and Arcanobacterium sp.