Cecrosins from Rhynchophorus ferrugineus Gut: A Promising Peptide Antibiotic against Multiple Antibiotic-Resistant Klebsiella pneumoniae Strains

Abstract

Klebsiella pneumoniae, a major pathogen, is increasingly resistant to antibiotics, posing a significant public health threat due to its role in various infections. This study aimed to isolate and characterize K. pneumoniae from clinical samples and evaluate the antibacterial activity of cecropins, antimicrobial peptides, against multidrug-resistant (MDR) K. pneumoniae isolates. K. pneumoniae isolates were characterized using cultural, morphological, biochemical, and molecular tests. Antibiotic resistance profiles were determined using standard methods. The antibacterial activity of cecropins was assessed using minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. Three K. pneumoniae strains A27782, K60365 and DD02425 (KPA2, KPK6, and KPDD) were identified, exhibiting extensive resistance to conventional antibiotics. Cecropins showed potent, strain-dependent bactericidal activity against the MDR isolates, with MIC and MBC values ranging from 0.00781 to 0.25000 mg/mL and 0.06250 to 0.50000 mg/mL, respectively. Statistical analysis confirmed significant differences in susceptibility among the isolates (p < 0.05).  Cecropins exhibit promising antibacterial activity against MDR K. pneumoniae isolates, suggesting their potential as alternative therapeutic agents against antibiotic-resistant infections. This study highlights the potential of cecropins as novel antibacterial agents against MDR K. pneumoniae, providing a new avenue for combating antibiotic resistance.