# Functional and Antimicrobial Properties of Propolis from Different Areas of Romania
## 3 Results
### Antimicrobial Activity and MIC
The most effective extract for the _E. faecalis_ strain ATCC 29212 was identified \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Propolis Extracts**} & \multicolumn{5}{c}{**Gram-positive Indicator Strains**} \\ \cline{2-6}  & _E. faecalis_ & _S. aureus_ & _S. aureus_ MRSA & _S. epidermidis_ & _L. monocytogenes_ \\  & **ATCC 29212** & **ATCC 25923** & **ATCC 43300** & **ATCC 12228** & **ATCC 35152** \\ \hline
**C1** & \(10.4\pm 0.3\) & \(12.8\pm 0.2\) & \(9.4\pm 0.4\) & \(11.1\pm 0.2\) & \(10.4\pm 0.4\) \\
**C2** & \(5.4\pm 0.3\) & \(12.2\pm 0.2\) & \(9.0\pm 0.3\) & \(8.1\pm 0.2\) & \(8.1\pm 0.1\) \\
**A** & \(5.3\pm 0.1\) & \(11.0\pm 0.2\) & \(8.5\pm 0.4\) & \(8.8\pm 0.2\) & \(9.2\pm 0.2\) \\
**S** & \(8.4\pm 0.3\) & \(7.3\pm 0.3\) & \(6.7\pm 0.2\) & \(6.9\pm 0.1\) & \(7.5\pm 0.4\) \\
**H** & \(5.9\pm 0.2\) & \(8.2\pm 0.2\) & \(7.2\pm 0.2\) & \(8.1\pm 0.3\) & \(6.5\pm 0.3\) \\
**Vancomycin (30 \(\mu\)g)** & \(15.3\pm 0.9\) & \(19.0\pm 0.08\) & \(18.0\pm 0.08\) & \(20.0\pm 0.1\) & \(17.0\pm 0.1\) \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Antimicrobial activity of propolis ethanolic extracts against the tested Gram-positive pathogenic bacteria. The data (mean \(\pm\) SD; \(n=3\)) are expressed as ZOI (mm). Different lower-case letters (a-f) in each column indicate significant differences \(p\) < 0.05. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Propolis Extracts**} & \multicolumn{5}{c}{**Gram-negative and Yeast Indicator Strains**} \\ \cline{2-6}  & _S. enterica_ & _K. pneumoniae_ & _P. aeruginosa_ & _E. coli_ & _A. baumannii_ & _C. albicans_ \\  & **ATCC 25928** & **ATCC 13883** & **ATCC 27853** & **ATCC 25922** & **ATCC 19606** & **ATCC 10231** \\ \hline
**C1** & \(7.4\pm 0.2\) & \(3.1\pm 0.1\) & \(10.5\pm 0.3\) & \(4.9\pm 0.1\) & \(7.5\pm 0.4\) & \(12.5\pm 0.6\) \\
**C2** & \(11.1\pm 0.2\) & \(5.7\pm 0.2\) & \(9.1\pm 0.3\) & \(6.1\pm 0.1\) & \(7.5\pm 0.4\) & \(8.1\pm 0.2\) \\
**A** & \(11.5\pm 0.4\) & \(5.5\pm 0.1\) & \(9.4\pm 0.4\) & \(4.9\pm 0.05\) & \(6.5\pm 0.2\) & \(8.9\pm 0.2\) \\
**S** & \(8.3\pm 0.2\) & \(7.2\pm 0.3\) & \(8.3\pm 0.2\) & \(7.1\pm 0.2\) & \(7.9\pm 0.1\) & \(7.1\pm 0.3\) \\
**H** & \(3.8\pm 0.1\) & \(0\pm 0\) & \(7.1\pm 0.1\) & \(4.2\pm 0.2\) & \(3.2\pm 0.1\) & \(7.3\pm 0.3\) \\
**Gentamycin (10 \(\mu\)g)** & \(19.0\pm 0.2\) & \({}^{2}\) & \(18.0\pm 0.08\) & \({}^{2}\) & \(10.0\pm 0.1\) & \({}^{2}\) & \(16.0\pm 0.08\) & \({}^{2}\) \\
**Fluconazole (25 \(\mu\)g)** & - & - & - & - & - & \(28.0\pm 0.2\) \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Antimicrobial activity of propolisols ethanolic extracts against the tested Gram-negative pathogenic bacteria and yeast strain. The data (mean \(\pm\) SD; \(n=3\)) are expressed as ZOI (mm). Different lowercase letters (a-e) in each column indicate significant differences \(p\) < 0.05.  
as C1, which exhibited an average propolis extract concentration of 0.75 mg/mL. This was followed by extracts C2 (1.00 mg/mL) and A (1.78 mg/mL). The lowest response to this strain was observed for extracts S (3.12 mg/mL) and H (4.06 mg/mL). Concerning _S. aureus_ ATCC 25923, the highest sensitivity was observed with extract C2, with an average of 0.25 mg/mL, followed by extract C1 and A, with 0.45 mg/mL. In contrast, the lowest sensitivity was observed for extracts S and H, with values of 0.78 mg/mL. For _S. aureus_ MRSA ATCC 43300, a general increase in resistance was observed among the various test organisms to all five propolis extracts. The most effective extract remained C1, with an average of 0.59 mg/mL, followed by extract A with 0.89 mg/mL. Extract H exhibited the lowest response, with an average concentration of 4.06 mg/mL, which is five times higher than the concentration required for _S. aureus_ ATCC 25923. The extracts with the most effective activity against _S. epidermidis_ ATCC 12228 were C1 and A, with a mean minimum inhibitory concentration (MIC) value of 0.59 mg/mL and 1.00 mg/mL, respectively. In contrast, the extracts S and H demonstrated comparatively reduced efficacy.