Chicken Cathelicidins Display Antimicrobial Activity against Multiresistant Bacteria without Inducing Strong Resistance

The increased prevalence of multidrug-resistant (MDR) bacteria in combination with the relatively limited development of new antibiotics presents a serious threat to public health. In chicken, especially Extended-Spectrum ß-Lactamase (ESBL) carrying Enterobacteriaceae are often asymptomatically present but can infect humans. Due to their broad range antimicrobial activity cathelicidins and other host defence peptides, are considered to be an attractive alternative to conventional antibiotics. In this study, the antimicrobial activity of three chicken cathelicidins against a broad array of multidrug resistant bacteria was determined. All three peptides showed high antibacterial activity independent of the presence of MDR characteristics. Induction experiments using S. aureus and K. pneumoniae showed that although an increase in resistance was initially observed, susceptibility towards chicken cathelicidins remained high and no major resistance was developed. The combined results underline the potential of chicken cathelicidins as a new alternative to antibiotics.