Effects of extracts from Italian medicinal plants on planktonic growth, biofilm formation and adherence of methicillin-resistant Staphylococcus aureus

Abstract

One-third of botanical remedies from southern Italy are used to treat skin and soft tissue infection (SSTI). Staphylococcus aureus, a common cause of SSTI, has generated increasing concern due to drug resistance. Many plants possess antimicrobial agents and provide effective remedies for SSTI. Our aim was to investigate plants from different ethnobotanical usage groups for inhibition of growth and biofilms in methicillin-resistant S. aureus (MRSA).Three groups were assessed: plant remedies for SSTI, plant remedies not involving the skin, and plants with no ethnomedical application. We screened 168 extracts, representing 104 botanical species, for activity against MRSA (ATCC 33593). We employed broth dilution methods to determine the MIC after 18 hours growth using an optical density (OD 600nm ) reading. Anti-biofilm effects were assessed by growing biofilms for 40 hours, then fixing and staining with crystal violet. After washing, 10% Tween 80 was added and OD 570nm readings were taken.Extracts from 10 plants exhibited an IC 50 ≤32 μg/ml for biofilm inhibition: Lonicera alpigena, Castanea sativa, Juglans regia, Ballota nigra, Rosmarinus officinalis, Leopoldia comosa, Malva sylvestris, Cyclamen hederifolium, Rosa canina, and Rubus ulmifolius. Limited bacteriostatic activity was evident. The anti-biofilm activity of medicinal plants was significantly greater than plants without any ethnomedical applications.

An ethnomedicinal survey of a Tashelhit-speaking community in the High Atlas, Morocco

“…(Citoglu et al, 2004). Antinociceptive activities have been observed for Ballota glandulosissima (Citoglu et al, 2005) and antimicrobial agents are present in Ballota nigra (Quave et al, 2008) Mkhinza (Dysphania ambrosioides), igg (Pistacia atlantica), imitk (Pistacia lentiscus), louz n'uili (Searsia tripartita), itzghi (Cladanthus scariosus), lgnbes (Tagetes sp. ), shih (Artemisia herba-alba), tlir (Dittrichia viscosa), irifi (Lonicera biflora), irgl (Cistus salviifolius, Cistus creticus), bilkam (Equisetum ramosissimum), algu (Retama dasycarpa), tekeda (Ceratonia siliqua), tswig (Juglans regia), azukni (Thymus saturejoides), afleyou (Mentha pulegium), grzguiel (Lavandula maroccana, Lavandula multifidia), ifzi (Marrubium vulgare), timzuri (Lavandula dentata), khzemt (Lavandula pedunculata, Lavandula stoechas), tatait (Micromeria graeca, Micromeria hochreutineri), tlba (Ajuga iva), timja (Mentha suaveolens), uarimsa (Ballota hirsuta), rman (Punica granatum), asln (Fraxinus dimorpha), zeet l3ud (Olea europaea), tirqa (Globularia alypum), azenzou (Clematis flammula), ashdir (Rubus ulmifolius), louz (Prunus dulcis), tarubi (Rubia peregrina), safsaf (Populus alba), ifski n'ughiul (Scrophularia laevigata), ifr tarrausht (Verbascum sp.…”

The Evaluation of the Antibacterial and Antioxidant Activity of Tarragon (Artemisia dracunculus L.) Essential Oil and Its Chemical Composition

“…The bacterial strain was inoculated in tryptic soy broth (TSB, Merck Ink, Darmstadt, Germany) at 37ºC overnight, and 0.5 McFarland Standard was prepared with densities of 1.5 × 108 cfu/mL in phosphate buffered saline (PBS) (11). The microtiter broth method in sterile 96-microwell plates was used for minimum inhibitory concentration (MIC) (12).…”

Synergistic interactions in mixed-species biofilms of pathogenic bacteria from the respiratory tract

“…The strongest synergism was observed between P. aeruginosa 31 and S. maltophilia 106: the biofi lm biomass of P31 was increased by more than 100-fold. The total number of cells remained constant during inoculation for both single-and dual-species biofi lm and the optical density values indicated the biofi lm biomass 8 .…”

“…The screening process was performed in 96-well microtiter plates using the crystal violet method 7,8 . Six bacterial strains, including P. aeruginosa (n = 2), A. baumannii (n = 2), and S. maltophilia (n = 2) were selected for single-and dual-species biofi lm formation.…”