Non-aureus Staphylococcus and Mammaliicoccus spp. (NASM) and NAS cell-free supernatants isolated from sheep inhibit major mastitis pathogens in vitro

This dataset contains supplementary material from an undergraduate research project that investigates the in vitro antimicrobial activity of non-aureus Staphylococcus spp. and Mammaliicoccus spp. against Staphylococcus aureus and Escherichia coli, common pathogens responsible for mastitis in dairy animals. The materials are: Table 2. Results of the in vitro inhibition assay using NAS CFS under different treatments: heat treatment, pH adjustment, heat treatment + pH adjustment, and control (untreated CFS). Results are presented with two dilutions (10⁻⁶ and 10⁻⁷ CFU/mL) tested at three CFS concentrations (12.5%, 25%, 50%) against E. coli. Table 3. Results of the in vitro inhibition assay using NAS CFS under different treatments: heat treatment, pH adjustment, heat treatment + pH adjustment, and control (untreated CFS). Results are presented with two dilutions (10⁻⁶ and 10⁻⁷ CFU/mL) tested at three CFS concentrations (12.5%, 25%, 50%) against S. aureus. Fig 1. Average of CFU/mL of E. coli after in vitro exposure to NAS CFS under diferente treatments: heat treatment, pH adjustment, heat treatment + pH adjustment, and control (untreated CFS). Results are presented with two dilutions (10⁻⁶ and 10⁻⁷ CFU/mL). Each boxplot aggregates data from 10 isolates per species (S. chromogenes, S. equorum, and S. xylosus), tested at three CFS concentrations (12.5%, 25%, 50%). Vertical lines indicate data variability, midlines represent the average, and symbols represent concentrations. Statistical analysis showed that combined heat treatment + pH adjustment significantly reduced E. coli CFU/mL counts compared with control (untreated CFS) and with single treatments (p < 0.05). No other treatments differed considerably from the control. Fig 2. Average of CFU/mL of S. aureus after in vitro exposure to NAS CFS under diferente treatments: heat treatment, pH adjustment, and heat treatment + pH adjustment, and control (untreated CFS). Results are presented for two serial dilutions (10⁻⁶ and 10⁻⁷ CFU/mL). Each boxplot aggregates data from 10 isolates per species (S. chromogenes, S. equorum, and S. xylosus), tested at three CFS concentrations (12.5%, 25%, and 50%). Vertical lines indicate data variability, midlinesrepresent the average, and symbols represent concentrations. Statistical analysis showed that combined heat treatment + pH adjustment significantly reduced S. aureus CFU/mL counts compared with control (untreated CFS) and with single treatments (p < 0.05). No other treatments differed considerably from the control. These results were obtained through prolonged in vitro assays during the study period and aim to support the findings discussed in the main research manuscript.