Antibacterial efficacy of Enterococcus microencapsulated bacteriocin on Listeria monocytogenes, Listeria innocua and Listeria ivanovi.

This study focused on the microencapsulation of enterocin from Enterococcus durans (E. durans MF5) in whey powder (WP) using a spray-drying technique followed by the evaluation of how complexation can preserve the enterocin structure and antimicrobial activity against food-borne pathogens. Crude enterocin samples (1 and 5%) were microencapsulated in 10% WP. The antimicrobial activity of unencapsulated (crude) enterocin and microencapsulated enterocin was tested against the target bacteria Salmonella Typhimurium, Escherichia coli, Listeria monocytogenes, Listeria innocua, and Listeria ivanovi. The microencapsulation yields were 31.66% and 34.16% for concentrations of 1 and 5% enterocin, respectively. There was no significant difference between these concentrations. Microencapsulated enterocin was efficient for up to 12 h of cocultivation with Listeria sp., and the concentration required to inhibit the growth of target bacteria presented values of 6400 AU/mL (arbitrary unit). Microencapsulated enterocin demonstrated enhanced efficacy against Listeria species and E. coli when compared with crude enterocin (p < 0.05). Fourier transform-infrared spectroscopy and differential scanning calorimetry results confirmed the presence of enterocin in the microparticles. Scanning electron microscopy showed cell damage of the target bacteria. The results showed that complexation with WP preserved enterocin antimicrobial activity during spray-drying, indicating its potential use as a food preservative.

Colonization by multidrug-resistant microorganisms of hospitalized newborns and their mothers in the neonatal unit context.

INTRODUCTION: The mother plays a fundamental role in the constitution and regulation of her child's healthy microbiota, however, preterm newborns are separated from their mothers soon after birth and transferred to Neonatal Intensive Care Units, being exposed the constant risk for the development of multidrug-resistant microorganisms' infections. The aim of this study was to explore the multidrug-resistant microorganism colonization of hospitalized babies and their mothers in the neonatal unit context. METHODOLOGY: A prospective case study conducted with hospitalized babies and their mothers in the Neonatal Unit at a university hospital. The sample was composed of 433 binomials (mother-child). Colonization culture samples were taken at the moment of the baby's discharge, via two swabs in the oral, nasal, axillary, inguinal, and rectal regions. RESULTS: The colonization incidence among the binomials, 30 (6.9%) were both colonized by multi-resistant microorganisms. Mothers of colonized babies (24.4%) demonstrated a higher chance of colonization in comparison to mothers of non-colonized babies (11.9%) (p = 0.002). Relationships were drawn between baby colonization and prematurity, extremely low birth weight, and non-exclusive maternal breastfeeding (p<0.05). ESBL-producing Gram-negative microorganisms were more frequent in the cultures of the binomials, with 35.9% of the babies colonized with Klebsiella spp. ESBL and 42.0% of the mothers with Escherichia coli ESBL. Furthermore, 50% of the binomials were colonized with E. coli ESBL. CONCLUSION: The prematurity, extremely low birth weight, and non-exclusive breastfeeding at hospital discharge were associated with baby colonization by multidrug-resistant microorganism. Furthermore, mothers of colonized children presented higher chances of colonization.