## 4 Discussion
With the exception of _S.thymra_ against _L. monocytogenes_, the EOs tested showed antibiofilm potential, but MBIC ranged at similar or higher values than those of their main compounds (\(p<0.05\)). The antagonistic effect between these compounds could possibly explain the difference in MBIC values against _E. coli_, _S._ Enteritidis, and _P. mirabilis_ species. Although _S.thymra_ EO consists mainly of \(\gamma\)-terpinene and carvacrol, the MBIC of _S.thymra_ EO against _L. monocytogenes_ biofilm formation was almost 4-fold lower than the MBIC of the two main compounds when tested alone (\(p<0.05\)), suggesting a possible synergistic effect with the other components of the oil against this strain. [PERSON] et al. [44] tested the antibiofilm activity of _Thymus vulgaris_ EO against seven clinically biofilm-forming bacteria. The MBIC determined for _E. coli_ and _P. mirabilis_ at 0.125% (\(v/v\)) and 0.25% (\(v/v\)), respectively, was in accordance with the results of the present study. _T. vulgaris_ EO inhibited the growth of _E. coli_ up to almost 70% at 0.75 mg/mL [45]. [PERSON] et al. [46] found a strong inhibitory effect of _T. vulgaris_ EO against the biofilm formation of _E. coli_ and _L. monocytogenes_ at 0.5 mg/mL and 2 mg/mL, respectively, in line with the results of this study, as _E. coli_ was more sensitive to _T. capitatus_ EO than _L. monocytogenes_. [PERSON] et al. [47] showed that the methanolic extract of _Thymus musili_ Velen. can inhibit the biofilm formation of _S._ Typhimurium, _E. coli_, and _L. monocytogenes_ by 36.59 \(\pm\) 2.84% at 5 mg/mL, 53.96 \(\pm\) 4.21% at 10 mg/mL and 41.96 \(\pm\) 3.42% at 5 mg/mL, respectively. The MBIC of _O. hirtum_ EO against _E. coli_ in this study was 1.2 (mg/mL), which was in agreement with [PERSON] et al. [48], as they reported inhibition of biofilm formation and removal of established _E. coli_ biofilm at 0.1% (\(v/v\)). [PERSON] et al. [49] screened 79 EOs for antibiofilm activity againstopathogenic _E. coli_ and noticed that oregano oil, thymre red oil, carvacrol, and thymol significantly inhibited biofilm formation at subinhibitory concentrations of less than 0.01% (\(v/v\)). Apparently, the antimicrobial and antibiofilm potential of EOs is closely linked to the composition of their main compounds. Variations in the abundances of carvacrol, thymol, \(p\)-cymene, and \(\gamma\)-terpinene can influence the antimicrobial efficacy of EOs against certain pathogens, suggesting either a possible antagonistic or synergistic effect depending on each case. Between the four main compounds tested, the strongest biofilm inhibition formation activity was noted by \(p\)-cymene followed by thymol, while carvacrol and \(\gamma\)-terpinene had the least effect on biofilm inhibition. The MBIC values of \(p\)-cymene against all bacterial biofilms tested were significantly (\(p<0.05\)) lower than those of the EOs, suggesting that other EOs components may influence the biofilm inhibition activity, potentially through antagonistic interactions. In accordance with the presented results, [PERSON] et al. [50] also demonstrated the strong antibiofilm activity of _T. capitatus_ EO, consisting mainly of \(p\)-cymene and thymol, against \(S\). Enteritidis and \(L\). _monocytogenes_ [MBIC values ranged between 0.03 and 0.13% (\(v/v\))]. Recently, [PERSON] et al. [32] suggested that \(p\)-cymene could directly affect some of the virulence genes of pathogenic bacteria, such as _Streptococcus mutans_. In addition, the combination of \(p\)-cymene with other compounds like carvacrol andlinal has shown increased synergistic effects against biofilms [51]. In their study, [PERSON] et al. [51] observed a reduction of approximately 30% in the total biomass of _Gardneella_ species biofilms due to \(p\)-cymene. Besides diminishing established biofilms, \(p\)-cymene was effective in inhibiting the initial attachment of microbial cells to surfaces, thus preventing biofilm formation.