Essential Oils Biofilm Modulation Activity, Chemical and Machine Learning Analysis—Application on Staphylococcus aureus Isolates from Cystic Fibrosis Patients

Abstract

Bacterial biofilm plays a pivotal role in chronic Staphylococcus aureus (S. aureus) infection and its inhibition may represent an important strategy to develop novel therapeutic agents. The scientific community is continuously searching for natural and “green alternatives” to chemotherapeutic drugs, including essential oils (EOs), assuming the latter not able to select resistant strains, likely due to their multicomponent nature and, hence, multitarget action. Here it is reported the biofilm production modulation exerted by 61 EOs, also investigated for their antibacterial activity on S. aureus strains, including reference and cystic fibrosis patients’ isolated strains. The EOs biofilm modulation was assessed by Christensen method on five S. aureus strains. Chemical composition, investigated by GC/MS analysis, of the tested EOs allowed a correlation between biofilm modulation potency and putative active components by means of machine learning algorithms application. Some EOs inhibited biofilm growth at 1.00% concentration, although lower concentrations revealed different biological profile. Experimental data led to select antibiofilm EOs based on their ability to inhibit S. aureus biofilm growth, which were characterized for their ability to alter the biofilm organization by means of SEM studies.

Anti-Virulence Activity of the Cell-Free Supernatant of the Antarctic Bacterium Psychrobacter sp. TAE2020 against Pseudomonas aeruginosa Clinical Isolates from Cystic Fibrosis Patients

“…Biofilm production was quantified based on microtiter plate biofilm assay (MTP), as previously reported [ 42 ]. Briefly, the wells of a sterile 96-well flat-bottomed polystyrene plate were filled with BHI containing a 1:100 dilution of overnight bacterial cultures (about 0.5 OD 600 nm).…”

Microscopy Methods for Biofilm Imaging: Focus on SEM and VP-SEM Pros and Cons

“…It is of crucial importance nowadays to design or screen anti-biofilm molecules that can effectively minimize and eradicate biofilm-related infections. In this kind of investigation, the use of different microscopy techniques is required to better understand the intimate details of the biofilms’ ultrastructure, their 3-D organization, cell population behavior, and reactions after drug treatments [ 12 ]. The development of novel morphological investigation approaches is therefore crucial.…”

In vitro interactions of Alternaria mycotoxins, an emerging class of food contaminants, with the gut microbiota: a bidirectional relationship

“…antibiotics; Majidpour et al 2017 ) and complex mixtures (i.e. essential oils; Papa et al 2020 ). Despite no information is currently available about both the mechanisms underlying this phenomenon and the anti- or pro-biofilm properties of the single compounds of the Alternaria extract, it could be hypothesized that some mycotoxins of the extract exert pro-biofilm effects, while others act as anti-biofilm factors, resulting, in mixture, in an inhibition of the biofilm production.…”