Submitted to: Probiotics and Antimicrobial Proteins
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/1/2009
Publication Date: 1/1/2009
Citation: Svetoch, E.A., Eruslanov, B.V., Kovalev, Y.N., Mitsevich, E.V., Levchuk, V.P., Fursova, N.K., Perelygin, V.V., Stepanshin, Y.G., Seal, B.S., Stern, N.J. 2009. Antimicrobial activities of bacteriocins E 50-52 and B 602 against antobiotic resistant strains involved in nosocomial infections. Probiotics and Antimicrobial Proteins. Volume 1 Pages 136-142. Interpretive Summary: Recognition of the dramatic rise in antibacterial resistance or drug resistance (DR) has caused substantial alarm and concern in the public, the media, in veterinary circles and in medical circles. We have been exploring and identifying bacteriocins (BCN) to provide potential alternatives and create alternative antimicrobial therapeutic treatments. Paenibacillus polymyxa NRRL B-30509 was used to produce BCN B-602 and Enterococcus faecium NRRL B-30746 produced BCN E 50-52. We tested 64 DR isolates from hospitals and determined the minimal inhibitory concentrations (MIC; mg/ml) to quantify susceptibility and resistance to antibiotic classes and our BCN. We observed high resistance of these isolates to the different classes of antibiotics whereas these same isolates were very susceptible to our BCN. The ranges of susceptibility of the clinical isolates were from =0.025 to 6.4 mg BCN/ml for Acinetobacter baumannii, Citrobacter freundii, Escherichia coli, Klebsiella pneumoniae, Proteus spp., Staphylococcus aureus. The potential applications of BCN to human medical and veterinary infections appear to provide a promising future for bacteriological research and potential applications.
Technical Abstract: The antimicrobial spectra of previously published bacteriocins (BCN) E 50-52 and B 602 was determined. The amino acid sequences, molecular weights and the isoelectric points of both E 50-52 and B 602 BCN were consistent with class IIa characteristics, contained 39 and 29 amino acid residues, molecular weights of 3,932 and 3,864 Da, and pI values of 8.5 and 7.2, respectively. We studied antibacterial activity against methicillin resistant Staphylococcus aureus, MRSA (n=10) and other prominent nosocomial bacterial agents (Acinetobacter baumannii, n=11; Citrobacter freundii, n=8; Escherichia coli, n=9; Klebsiella pneumoniae, n=10; Proteus, n=6; and Pseudomonas aeruginosa, n=10) collected from Russian hospitals during 2003-2007. Antimicrobial resistance was determined by Kirby-Bauer disc-diffusion assay and measured by minimal inhibitory concentrations (MICs). Moreover, Enterobacteriaceae bacterial strains were characterized for the presence of the resistance genes using a polymerase chain reaction (PCR) assay. The MIC values of the same isolates ranged from < 0.025 to 1.56 mg/ml for BCN B 602 and 0.05 to 6.25 mg/ml for BCN E 50-52. For the 64 diverse clinical isolates tested, antibiotic resistance was high while the susceptibility to the BCN tested was remarkably good. The potentials for application of BCN in clinical settings as therapeutic agents appear quite promising.