Inhibitory effect of Persea cordata Mez. (pau-andrade) bark extracts against Clostridium perfringens causing gangrenous mastitis

ABSTRACT

Introduction: Gangrenous mastitis is a special clinical presentation of mastitis in cattle and small ruminants. The bark of the tree Persea cordata Mez. is used in Brazilian ethnoveterinary medicine to treat wounds in farm animals. Objectives: Examine in vitro antimicrobial action of apolar fractions of P. cordata bark against a wild strain of C. perfringens isolated from the udder of a cow with gangrenous mastitis, and against a reference strain. Methods: A milk sample was collected from the udder, aliquots were diluted and Gram-stained smears were performed. The aliquots were inoculated in broth and planted in blood agar, and then incubated in anaerobiosis at 37oC / 24h. Biochemical identification was based on bacterial isolation. In vitro inhibitory activity of apolar fractions of P. cordata was evaluated by agar diffusion and MIC (minimum inhibitory concentration) using the agar dilution method. Results: In both tests the plant extracts displayed significant in vitro inhibitory activity against the clinical and reference strains of C. perfringens assayed. Conclusion: The study is the first demonstration of the inhibitory effect of P. cordata on C. perfringens, due to its antimicrobial properties, which serves as evidence supporting its folk use. The extracts could be used as coadjuvants in the treatment of gangrenous mastitis(AU)