Assessment of Microbial Colonization on Used Neonatal Feeding Nipples and Infection Control Management Strategies

<title>Abstract</title> <p> Objective To investigate the bacterial distribution and dynamics on used neonatal feeding nipples under varying exposure durations and environmental settings, thereby providing evidence for standardized nipple management and infection control during neonatal feeding. Methods A convenience sampling method was used to select 118 used neonatal feeding nipples that had not been cleaned or disinfected between May 1 and September 30, 2025. After feeding, the nipples were exposed in the ward or clinic for 3 or 6 hours. The 0-hour sampling was defined as oral swabs collected immediately after feeding. Subsequently, swab samples were collected from the surface of each nipple. Bacterial culture and identification were performed to investigate bacterial distribution. Unused nipples from the same batch served as negative controls. The positive detection rates and bacterial composition on the nipple surfaces were compared across different exposure durations and settings. Results A total of 19 bacterial strains were detected across all samples, all of which were common oral bacteria in newborns, including <italic>Staphylococcus haemolyticus, Staphylococcus aureus</italic> , and <italic>Klebsiella pneumoniae</italic> . The bacterial detection rate on nipple samples at 3 hours post-feeding was significantly higher than that at 0 hours (P &lt; 0.05). The detection rates at 0, 3, and 6 hours after use showed an increasing trend (4.24% vs. 10.17% vs. 13.56%), although the difference was not statistically significant (P &gt; 0.05). No significant difference in bacterial detection rate was observed between different exposure settings (ward vs. consulting room). Conclusions Common bacteria could be detected on the surface of used neonatal feeding nipples within a short period of time, and the bacterial detection rate increased with prolonged exposure. No significant difference in detection rate was observed between different exposure settings (ward vs. clinic). In neonatal wards, it is recommended to avoid leaving used nipples exposed, to clean and disinfect them promptly after use, or to consider using disposable feeding equipment to reduce the risk of neonatal infection. In family care settings, disinfection after each use is not necessary. </p>