Evaluation of Bacterial Contamination Risk in Milk Preparations and Antibiotic Resistance Patterns in the Neonatal Unit of Treichville University Hospital, Côte d'Ivoire

Abstract

Background: Breastfeeding remains the physiological and optimal mode of infant feeding, conferring critical benefits for early health, growth, and neurodevelopment (Victora et al., 2023). For mothers, exclusive breastfeeding is associated with enhanced postpartum weight loss, a decreased risk of breast and ovarian cancers, improved glucose metabolism, and lower incidence of cardiovascular disorders (Rollins et al., 2022; Binns et al., 2020). Despite these advantages, alternative feeding methods are often employed in hospital neonatal units, particularly when breastfeeding is not feasible. In such contexts, the safety of infant milk substitutes becomes paramount. Consequently, an evaluation of milk preparation systems and hygiene practices within the neonatology unit was conducted. The risk of microbial contamination associated with milk preparation procedures was assessed using a structured questionnaire administered to preparation staff, focusing on hygiene protocols, equipment handling, and environmental sanitation. Aims: The aim of our work is to ensure the safety of milk formulas used for newborn nutrition in the neonatal department of Treichville University Hospital. Study Design: This manuscript sheds light on a deeply important issue. The safety of milk preparations given to newborns in a hospital setting. By revealing the presence of harmful bacteria and their resistance to antibiotics, it brings attention to the hidden risks in neonatal care, especially for fragile infants. The study emphasizes the need for better hygiene and monitoring practices to protect newborns from preventable infections. It’s a timely and necessary contribution to improving infant health and hospital safety. Place and Duration of Study: In this study, sample collection was conducted at the Treichville University Hospital Center (Abidjan, Côte d'Ivoire) from Novembre 2017 to May 2018. To ensure the reliability and representativeness of the data, samples were systematically collected every day between 8:00 and 10:00 a.m. Methodology: Out of a total of 59 samples, 36 milk preparation samples grouped into 6 batches and 23 samples from hands, nostrils and ambient air were collected and analyzed in accordance with microbiological standards for foodstuffs. Analysis of the batches showed a predominance of S. aureus, followed by E. coli and finally P. aeruginosa. Presumptive isolates were identified by biochemical tests, and antibiotic susceptibility tests were carried out in accordance with the recommendations of the Antibiogram Committee of the French society of Microbiology. . Results: Microbiological analyses revealed high microbial loads in the milk formula, including Escherichia coli (3.6 × 10⁴ UFC/mL), Pseudomonas aeruginosa (7.95 × 10³ UFC/mL), and Staphylococcus aureus (3.6 × 10³ UFC/mL). Enterococcus faecalis was not detected. Antibiotic susceptibility testing showed a high level of resistance among the isolates, particularly to β-lactam antibiotics. A significant proportion of E. coli isolates (35%) exhibited an extended-spectrum β-lactamase (ESBL)-producing phenotype. Furthermore, 44,4% of S. aureus strains displayed resistance to aminoglycosides, consistent with a kanamycin-tobramycin-gentamicin (KTG) resistance phenotype. Additional ESBL-producing phenotypes were also identified among P. aeruginosa isolates. Overall, these strains demonstrated multidrug resistance, representing a serious threat to effective antibiotic therapy in clinical settings. Conclusion: The results obtained showed a predominance of E. coli with an average microbial load of 3,6 x 104 UFC/mL, followed by S. aureus (3,7 x 103 UFC/mL) and finally P. aeruginosa (7,95 x 103 UFC/mL). However, a diversity of bacterial strains in the environment was observed. Given the high microbial load of the strains compared with food microbiology standards, milk intended for newborns is judged to be of unsatisfactory sanitary quality.