## 3 Results  
Table 1 summarizes the means and standard deviations of the ZOIs for each C-CaOH\({}_{2}\) NP concentration against all strains. Overall, a positive activity was observed from all four C-CaOH\({}_{2}\) NP concentrations that varied between bacteria. The diffusion of C-CaOH\({}_{2}\) NP samples into the agar displayed a white halo bordering the clear distinct inhibition zones, whereas positive controls showed clear sizable zones (Figure 1). The Kruskal-Wallis mean rank analysis demonstrated statistical significance in all bacteria (\(p<0.05\)). The largest recorded zone diameters were at the 150 mg/mL concentration in all tested strains. The inhibitory activity was slightly higher against Gram-negative strains compared to Gram-positive pathogens, as they showed larger ZOIs. At the lowest concentration of 50 mg/mL, _S. epidermidis_ showed the highest inhibition zones amongst the Gram-positive aerobes (8 \(\pm\) 0.6 mm), followed by _S. aureus_ (7 \(\pm\) 0.6 mm). Furthermore, both bacteria showed nearly similar activity at 75 mg/mL (_S. epidermidis_ 9 \(\pm\) 0.0 mm; _S. aureus_ 9 \(\pm\) 1.0 mm). Conversely, _E. faecalis_ showed no activity at 50 and 75 mg/mL. At 100 mg/mL, the zone of _E. faecalis_ (7 \(\pm\) 0.6 mm) was statistically different from lower concentrations, whereas _S. aureus_ and _S. epidermidis_ showed no significant change compared to 75 mg/mL. At 150 mg/mL, _S. aureus_ showed the largest zones (11 \(\pm\) 0.3 mm) among the Gram-positive aerobes, followed by _S. epidermidis_ (10 \(\pm\) 0.6 mm) and _E. faecalis_ (9 \(\pm\) 0.6 mm). For the Gram-negative aerobes, _P. aeruginosa_ exhibited the highest response at 75, 100, and 150 mg/mL concentrations (11 \(\pm\) 0.0, 11 \(\pm\) 0.3, and 12 \(\pm\) 0.6 mm, respectively). On the other hand, the lowest activity observed among them was with _K. pneumoniae_. There was no difference in zone diameter between the 50 and 75 mg/mL concentrations in both _K. pneumoniae_ (9 \(\pm\) 0.0 mm) and _E. coli_ (10 \(\pm\) 0.0 mm). Moreover, both bacteria showed no significant change in zone size at 100 mg/mL concentration. At 150 mg/mL, the zones observed in _E. coli_ (11 \(\pm\) 0.3 mm) and _K. pneumoniae_ (10 \(\pm\) 0.6 mm) were the largest among the different concentrations. The anaerobic pathogen _P. micra_ showed low response to all concentrations. Both 50 and 75 mg/mL displayed equal zones (6 \(\pm\) 0.6 mm), whereas slightly higher inhibition was observed at 100 and 150 mg/mL concentrations (7.5 \(\pm\) 0.5 mm and 8 \(\pm\) 0.6 mm, respectively). The Mann-Whitney pair-wise comparisons of C-CaOH\({}_{2}\) NPs with reference to control showed statistical significance in all pathogens (\(p<0.05\)). When comparing the zones between the four concentrations, _S. aureus_ demonstrated a significant statistical difference between 100 and 150 mg/mL (\(p<0.043\)) (Figure 2). _P. aeruginosa_ showed a statistically significant difference between 50 and 75 mg/mL (\(p<0.025\)). Furthermore, there was a significant difference observed between 75 and 100 mg/mL in _E. faecalis_ (\(p<0.034\)). On the other hand, no statistically significant differences were found between concentrations in _S. epidermidis_, _K. pneumoniae_, _E. coli_, and _P. micra_. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multicolumn{6}{c}{**Mean \(\pm\) Standard Deviation of Zones of Inhibition (ZOI) in mm**} \\ \hline
**Bacterial Strains** & **50 mg/mL** & **75 mg/mL** & **100 mg/mL** & **150 mg/mL** & **Control** \\ \hline _S. aureus_ & 7.3 \(\pm\) 0.6 & 9 \(\pm\) 1 & 9.3 \(\pm\) 0.6 & 10.8 \(\pm\) 0.3 & 26.7 \(\pm\) 0.6 \\ \hline _S. Epidermidis_ & 8.3 \(\pm\) 0.6 & 9 \(\pm\) 0 & 9.5 \(\pm\) 0.5 & 9.7 \(\pm\) 0.6 & 40.3 \(\pm\) 0.6 \\ \hline _E. faecalis_ & 0  
Figure 1: Agar well diffusion with the different C-CaOH\({}_{2}\) NPs concentrations against aerobic and anaerobic strains. The diffusion of C-CaOH\({}_{2}\) NPs displayed a white halo surrounding the inhibition zones. A: 50 mg/mL C-CaOH\({}_{2}\) NPs concentration showed the least ZOI activity.