Kitchen Sponges as Reservoirs of Foodborne Pathogens: Microbial Growth Dynamics, Surface Cross-Contamination, and Hygiene Implications

colony-forming units (CFU) per sponge section). Escherichia coli and Salmonella Enteritidis rapidly established stable populations reaching approximately 9 log CFU per sponge section, whereas S. aureus showed limited growth of approximately 4 log CFU per sponge section, indicating species-specific interactions with the resident microbiota. Notably, pathogen populations remained stable after 3 days of desiccation, confirming the role of sponges as long-term microbial reservoirs. Contact between colonized sponges and surfaces under mild pressure resulted in transfer of up to 5 log CFU to contacted surfaces, highlighting realistic domestic transmission pathways. Sensory changes such as odor or discoloration were not correlated with microbial load, indicating that visual assessment is unreliable for sponge replacement decisions. These results underscore the role of kitchen sponges as critical microbial reservoirs in households and emphasize the need for regular sponge replacement or the use of alternative cleaning utensils. The standardized sponge model developed in this study provides a valuable platform for evaluating sanitation strategies and for understanding microbial interactions relevant to domestic hygiene and public health.