Composition of Human Breast Milk Microbiota and Its Role in Children’s Health / 대한소아소화기영양학회지

Human milk contains a number of nutritional and bioactive molecules including microorganisms that constitute the so-called “Human Milk Microbiota (HMM)”. Recent studies have shown that not only bacterial but also viral, fungal, and archaeal components are present in the HMM. Previous research has established, a “core” microbiome, consisting of Firmicutes (i.e., Streptococcus, Staphylococcus), Proteobacteria (i.e., Serratia, Pseudomonas, Ralstonia, Sphingomonas, Bradyrhizobium), andActinobacteria (i.e., Propionibacterium, Corynebacterium). This review aims to summarize the main characteristics of HMM and the role it plays in shaping a child’s health. We reviewed the most recent literature on the topic (2019-2021), using the PubMed database. The main sources of HMM origin were identified as the retrograde flow and the entero-mammary pathway. Several factors can influence its composition, such as maternal body mass index and diet, use of antibiotics, time and type of delivery, and mode of breastfeeding. The COVID-19 pandemic, by altering the mother-infant dyad and modifying many of our previous habits, has emerged as a new risk factor for the modification of HMM.HMM is an important contributor to gastrointestinal colonization in children and therefore, it is fundamental to avoid any form of perturbation in the HMM that can alter the microbial equilibrium, especially in the first 100 days of life. Microbial dysbiosis can be a trigger point for the development of necrotizing enterocolitis, especially in preterm infants, and for onset of chronic diseases, such as asthma and obesity, later in life.

MRSA ST22-IVa [EMRSA-15 clone] in Palermo, Italy

Epidemic spread of methicillin-resistant Staphylococcus aureus [MRSA] strains carrying the Staphylococcal Chromosomal Cassettes [SCC] mec type IV is being increasingly reported in many geographical areas. A survey to determine the prevalence and characteristics of MRSA SCCmec IV isolates identified in four general hospitals in Palermo, Italy, was carried out. During the period February-June 2009, SCCmec type IVa has been found in12 out of 94 isolates. Nine isolates from all hospitals and all strains from a NICU outbreak occurring in the same period were attributed with the ST22-IVa [EMRSA-15] clone. In our setting, due to the changing MRSA epidemiology, detection of SCCmec IV could be poorly predictive of CA-MRSA