Evaluation of the antimicrobial activity of the K9CATH peptides of 21 and 38 amino acids against Brucella abortus and Brucella melitensis

Abstract

Brucellosis is a worldwide zoonotic disease endemic in Mexico and of major economic importance to the livestock
industry and public health. The increase of resistance and reduced susceptibility to common anti-brucella drugs in
several Brucella species reported in recent studies have motivated the researchers to search for new antimicrobials
where the antimicrobial peptides can be an alternative. The present is a pilot study in which the in vitro antimicrobial
susceptibility of two bovine field strains of B. abortus and B. melitensis were evaluated against the antimicrobial peptides
canine cathelicidin (K9CATH) of 21 and 38 amino acids. Minimum inhibitory concentration (MIC) of 8 μg/ml for both
cathelicidins was obtained against B. abortus, while none of the cathelicidins up to 128 μg/ml inhibited B. melitensis
growth. Further studies including more clinical isolates of brucella and the use of combinations of these peptides with
the conventionally prescribed anti brucellosis drugs could be useful in ascertaining whether these peptides have a
synergistic effect.