## 3 Results and Discussion
### Antibacterial Activity
#### 3.4.1 Inhibition Zones of Honey Extracts against Different Microorganisms  
The disk diffusion method revealed that honey samples exhibited increased antibacterial activity against Gram-negative bacteria, particularly _S. typhimurium_, and moderate activity against Gram-positive bacteria, with notable activity against _S. aureus_. Regarding the Gram-positive strains, the growth inhibition ranged between 23.2 \(\pm\) 1.2 (H12) and 11.76 \(\pm\) 1.3 (H10) against _S. aureus_. The Bulgarian samples (i.e., H1 and H2) manifested the capability to inhibit _S. pyogenes_. No activity against all Gram-positive bacteria has been observed in the case of H8 and H18 samples. Significant activity manifested against the Gram-negative bacteria, particularly _S. typhimurium_, which displayed an inhibition diameter ranging from 16.1 \(\pm\) 0.1 (H1) to 10.0 \(\pm\) 0.1 (H17), with no inhibition observed in H15. Overall, out of the evaluated honey types, the Bulgarian samples (i.e., H1 and H2), \begin{table}
\begin{tabular}{c c c c c c} \hline
**ID** & **EC** & **KA** & **ST** & **SP** & **SA** & **LM** \\ \hline H1 & 11.7 \(\pm\) 0.7 ab & 10.0 \(\pm\) 0.0 d & 16.1 \(\pm\) 0.1 a & 26.8 \(\pm\) 0.1 a & 21.3 \(\pm\) 0.4 a & 12.7 \(\pm\) 0.5 b \\ H2 & 12.2 \(\pm\) 0.8 ab & 15.5 \(\pm\) 0.8 a & 15.6 \(\pm\) 0.2 a & 23.1 \(\pm\) 1.0 b & 22.3 \(\pm\) 0.8 a & 15.1 \(\pm\) 0.3 a \\ H3 & 10.6 \(\pm\) 0.0 cd & 10.5 \(\pm\) 0.5 d & 11.6 \(\pm\) 0.1 c & 17.4 \(\pm\) 0.5 c & 16.9 \(\pm\) 0.2 d & 11.5 \(\pm\) 0.1 b \\ H4 & 10.9 \(\pm\) 0.4 c & 14.9 \(\pm\) 1.4 a & 15.6 \(\pm\) 0.8 a & 21.5 \(\pm\) 3.2 b & 20.6 \(\pm\) 1.0 b & 14.5 \(\pm\) 0.1 a \\ H5 & 9.9 \(\pm\) 0.3 d & 13.9 \(\pm\) 0.3 b & 12.8 \(\pm\) 1.1 c & 18.2 \(\pm\) 0.6 c & 16.4 \(\pm\) 0.4 d & 12.6 \(\pm\) 0.1 b \\ H6 & 10.8 \(\pm\) 0.1 c & 14.0 \(\pm\) 0.0 b & 12.5 \(\pm\) 0.8 c & 15.4 \(\pm\) 0.4 c & 18.3 \(\pm\) 1.6 c & 13.6 \(\pm\) 0.4 ab \\ H7 & 10.7 \(\pm\) 0.1 c & 12.5 \(\pm\) 1.8 c & 13.5 \(\pm\) 1.2 b & 19.6 \(\pm\) 0.0 bc & 18.9 \(\pm\) 1.3 bc & 14.9 \(\pm\) 0.1 a \\ H8 & 10.7 \(\pm\) 0.3 c & 11.9 \(\pm\) 0.1 c & 10.2 \(\pm\) 0.1 c & ND & ND & ND \\ H9 & 11.5 \(\pm\) 0 b & 13.5 \(\pm\) 0.8 b & 13.9 \(\pm\) 0.8 b & 22.0 \(\pm\) 0.5 b & 22.2 \(\pm\) 0.9 a & 15.3 \(\pm\) 0.4 a \\ H10 & 12 \(\pm\) 0.8 ab & 13.7 \(\pm\) 1.1 b & 16.1 \(\pm\) 0 a & 20.5 \(\pm\) 1.1 b & 11.76 \(\pm\) 1.3 d & 12.5 \(\pm\) 0.2 b \\ H11 & 10.5 \(\pm\) 1.0 cd & 14.4 \(\pm\) 0.8 ab & 11.9 \(\pm\) 0.0 c & 11.0 \(\pm\) 0.1 d & 17.9 \(\pm\) 0.4 c & ND \\ H12 & 10.8 \(\pm\) 0.3 c & 14.3 \(\pm\) 1.9 ab & 13.2 \(\pm\) 0.1 b & 21.7 \(\pm\) 0.6 b & 23.2 \(\pm\) 1.2 a & 13.2 \(\pm\) 0.2 ab \\ H13 & 10.6 \(\pm\) 0.2 cd & 13.0 \(\pm\) 0.8 bc & 11.2 \(\pm\) 1.6 c & 9.9 \(\pm\) 0.4 d & 14.2 \(\pm\) 1.1 d & ND \\ H14 & 10.7 \(\pm\) 0.6 c & 11.8 \(\pm\) 1.5 cd & 14.3 \(\pm\) 1.8 b & 17.9 \(\pm\) 0.2 c & 18.4 \(\pm\) 0.0 c & ND \\ H15 & 10.8 \(\pm\) 0.1 c & 9.6 \(\pm\) 0.0 d & ND & 19 \(\pm\) 0.3 c & 20.0 \(\pm\) 0.5 c & 11.2 \(\pm\) 0.0 b \\ H16 & 10.9 \(\pm\) 0.1 c & 10.9 \(\pm\) 0.3 d & 10.6 \(\pm\) 0.6 c & ND & 12.8 \(\pm\) 0.7 d & ND \\ H17 & 10.5 \(\pm\) 0.1 cd & 9.8 \(\pm\) 0.1 d & 10.0 \(\pm\) 0.1 c & ND & ND & ND \\ H18 & 13.9 \(\pm\) 0.8 a & 13 \(\pm\) 0.2 bc & 16.2 \(\pm\) 1.7 a & 22.9 \(\pm\) 1.6 b & 22.7 \(\pm\) 0.4 a & 16.3 \(\pm\) 0.5 a \\ \hline \end{tabular} 10055: EC–_Eskrridia coli;_ KA–_Klebsiella aerogenes;_ ST–_Salmonella typhimurium;_ SP–_Streprotoccus pyogenes_; SA–_Staphylococcus aureus_; LM–_Listeria monocytogenes_. ND–not detected or no data available (no inhibition zone). Values in the same column annotated with lowercase characters denote statistically significant variations in inhibitory activity against the evaluated microorganisms (established by post hoc Tukey HSD test, \(p<\) 0.05).  
\end{table} 
Table 5: Inhibition zones of honey samples against different microorganisms (in mm), expressed as average \(\pm\) standard deviation (\(n=2\)). Figure 2: Antibacterial determinations for samples 1 and 2 (**left**) and 17 and 18 (**right**), for the undiluted honey samples (100% concentration).