RESUMEN
OBJECTIVES: To determine the association between diet during pregnancy and infancy, including breastfeeding vs formula feeding, solid food introduction, and the infant intestinal microbiome. STUDY DESIGN: Infants participating in the Vitamin D Antenatal Asthma Reduction Trial were included in this study (n = 323). Maternal and infant diets were assessed by questionnaire. Infant stool samples were collected at age 3-6 months. Stool sequencing was performed using the Roche 454 platform. Analyses were stratified by race/ethnicity. RESULTS: Breastfeeding, compared with formula feeding, was independently associated with infant intestinal microbial diversity. Breastfeeding also had the most consistent associations with individual taxa that have been previously linked to early-life diet and health outcomes (eg, Bifidobacterium). Maternal diet during pregnancy and solid food introduction were less associated with the infant gut microbiome than breastfeeding status. We found evidence of a possible interaction between breastfeeding and child race/ethnicity on microbial composition. CONCLUSIONS: Breastfeeding vs formula feeding is the dietary factor that is most consistently independently associated with the infant intestinal microbiome. The relationship between breastfeeding status and intestinal microbiome composition varies by child race/ethnicity. Future studies will need to investigate factors, including genomic factors, which may influence the response of the microbiome to diet. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00920621.
Asunto(s)
Dieta , Microbioma Gastrointestinal , Bacteroides/genética , Bacteroides/aislamiento & purificación , Bifidobacterium/genética , Bifidobacterium/aislamiento & purificación , Lactancia Materna , Clostridium/genética , Clostridium/aislamiento & purificación , Heces/microbiología , Femenino , Humanos , Lactante , Fórmulas Infantiles , Masculino , Embarazo , ARN Ribosómico 16S , Factores Raciales , Análisis de Secuencia de ARN , Encuestas y CuestionariosRESUMEN
We report the case of a patient from Brazil with a bloodstream infection caused by a strain of methicillin-resistant Staphylococcus aureus (MRSA) that was susceptible to vancomycin (designated BR-VSSA) but that acquired the vanA gene cluster during antibiotic therapy and became resistant to vancomycin (designated BR-VRSA). Both strains belong to the sequence type (ST) 8 community-associated genetic lineage that carries the staphylococcal chromosomal cassette mec (SCCmec) type IVa and the S. aureus protein A gene (spa) type t292 and are phylogenetically related to MRSA lineage USA300. A conjugative plasmid of 55,706 bp (pBRZ01) carrying the vanA cluster was identified and readily transferred to other staphylococci. The pBRZ01 plasmid harbors DNA sequences that are typical of the plasmid-associated replication genes rep24 or rep21 described in community-associated MRSA strains from Australia (pWBG745). The presence and dissemination of community-associated MRSA containing vanA could become a serious public health concern.