In Vitro Antibacterial, Anti-Adhesive and Anti-Biofilm Activities of Krameria lappacea (Dombey) Burdet & B.B. Simpson Root Extract against Methicillin-Resistant Staphylococcus aureus Strains.

Carlo Genovese,Debora Lo Furno,Alfio Distefano,Francesco Attanasio,Daria Nicolosi,Francesco Bellia,Gianna Tempera,Floriana D’Angeli,Fabio Milardo,Giovanni Li Volti,Valentina Di Salvatore,Mariarita Spampinato,Giuliana Mannino

doi:10.3390/antibiotics10040428

Abstract

Methicillin-resistant Staphylococcus aureus (MRSA) represents a serious threat to public health, due to its large variety of pathogenetic mechanisms. Accordingly, the present study aimed to investigate the anti-MRSA activities of Krameria lappacea, a medicinal plant native to South America. Through Ultra-High-Performance Liquid Chromatography coupled with High-Resolution Mass spectrometry, we analyzed the chemical composition of Krameria lappacea root extract (KLRE). The antibacterial activity of KLRE was determined by the broth microdilution method, also including the minimum biofilm inhibitory concentration and minimum biofilm eradication concentration. Besides, we evaluated the effect on adhesion and invasion of human lung carcinoma A549 cell line by MRSA strains. The obtained results revealed an interesting antimicrobial action of this extract, which efficiently inhibit the growth, biofilm formation, adhesion and invasion of MRSA strains. Furthermore, the chemical analysis revealed the presence in the extract of several flavonoid compounds and type-A and type-B proanthocyanidins, which are known for their anti-adhesive effects. Taken together, our findings showed an interesting antimicrobial activity of KLRE, giving an important contribution to the current knowledge on the biological activities of this plant.

Highlights

Bacteria colonization of specific districts of the human body constitutes what is defined as the “human microbiome”
Given the pathogenic role played by S. aureus at the pulmonary level, we investigated whether the Krameria lappacea root extract (KLRE) was able to prevent the adhesion and invasion of the selected strains against the human lung carcinoma A549 cell Hlionwe.eFvienra, lilnyt,hwisesatulsdoyp, tehrefoarumthedortshme achinelmy iincavleastniaglaytseids tohfethcheeKmLiRcaEl,cboymupsoisnigtioann oafptphreoeaxc-h trbaacste. dSpoencUifilctarallyH, tihgehy-Piesorfloatremdaanncde LchiqauraidcteCrhizreodmtahteogtarnanpihnysycoruooptl,eidnwpaitrhticHuilgahrthReesporlouatniotnhoMcyaasnsisdpiencstr[2o7m].etry (HRMS)
Given the pathogenic role played by S. aureus at the pulmonary level, we investigated whether the KLRE was able to prevent the adhesion and invasion of the selected strains against the human lung carcinoma A549 cell line

Summary

Introduction

Bacteria colonization of specific districts of the human body constitutes what is defined as the “human microbiome”. S. aureus is endowed with an external capsule of a polysaccharidic nature, that allows it to escape from the phagocytic action of the immune cells [7,8]. This ability is supported by the expression of a series of enzymes, including coagulase [9], lipase [10], hyaluronidase [11], staphylokinase [12], by which the bacterium can elude the host’s innate and adaptive immune response, promoting tissues invasion. A further evasion mechanism consists of biofilm production, a polysaccharidic matrix, which acts like a barrier protecting itself from the immune system and antibiotics action, favoring its persistence in the host [13]

Results

Discussion

Conclusion