Antimicrobial activity of plant extracts against carbapenem-producing Klebsiella pneumoniae and in vivo toxicological assessment

ABSTRACT

The global spread of multidrug-resistant strains has prompted the scientific community to explore novel sources of chemicals with antimicrobial activity. The aim of the study was to examine the antimicrobial activity in vitro of 28 extracts against carbapenem-producing Klebsiella pneumoniae, individually and in combination with antibiotics and in vivo toxicological assessment of the most active product. The multi-resistant K. pneumoniae strain was submitted for phenotypic and molecular characterization. The antibacterial activity of 28 plant extracts was evaluated alone and in combination with antibiotics against this strain through the agar disk diffusion. Of these, 16 extracts showed synergism against carbapenem-producing K. pneumoniae, being that B. crassifolia extract exhibited synergism with three antibiotics. Based on this assessment, B. crassifolia-extract-induced toxicity on Swiss male mice was evaluated by administering this extract and subsequently determining apoptosis and splenic phagocytosis using the comet and micronucleus assays. The results of this study showed that B. crassifolia extract had synergistic activity promising and groups treated with B. crassifolia exhibited no genotoxic or mutagenic activity, indicating that B. crassifolia extract exerted beneficial effects and appeared safe to use at the studied concentrations.

KEYWORDS:

• Byrsonima crassifolia L. Kunth
• genotoxicity
• synergism
• KPC
• multidrug Resistant

Highlights

• Antimicrobial activity of 28 extracts against carbapenem-producing Klebsiella pneumoniae was evaluated.

• Extract of Byrsonima crassifolia showed synergism with imipenem, piperacillin/tazobactam, and polymyxin.

• No damage to DNA or mutagenic activity of Byrsonima crassifolia was observed in genotoxicity and mutagenicity tests using the comet and micronucleus assay.

Acknowledgments

The authors thank Universidade Federal da Grande Dourados (UFGD) and Universidade Federal do Mato Grosso do Sul (UFMS).

Disclosure statement

The authors declare that there are no conflicts of interest.

Supplementary material

Supplemental data for this article can be accessed on the publisher’s website.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This research was supported by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior [Finance Code 001], and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) [grant number 407791/2013-2].