Meconium microbiota in naturally delivered canine puppies.

BACKGROUND: Microbial colonization during early life has a pivotal impact on the host health, shaping immune and metabolic functions, but little is known about timing and features of this process in dogs. The objectives of this study were to characterize the first step of intestinal microbiota development in naturally delivered canine puppies and to investigate its relationship with the maternal bacterial flora, using traditional culture and molecular analyses. Sixty puppies of two breeds, Appenzeller Cattle Dog (n = 3 dams) and Lagotto Romagnolo (n = 6), housed in the same breeding kennel, were included in the study. Swabs were collected in duplicate (for culture and for molecular analysis) from the dams' vagina and rectum at the end of parturition, from puppies' rectum, before maternal care, and from the environment (floor of the nursery and parturition box). RESULTS: 93.3% meconium samples showed bacterial growth, limited to a few colonies in 57.0% of cases. High growth was detected for Enterococcus faecalis, which was the most frequently isolated bacterium. The genus Enterococcus was one of the most represented in the dams' rectum and vagina (88.9% and 55.6%, respectively). The genera Staphylococcus, Enterococcus, Escherichia and Proteus were also often isolated in meconium but were usually present in maternal samples as well, together with ubiquitous bacteria (Acinetobacter, Psychrobacter). In the environmental samples, just a few bacterial species were found, all with low microbial load. Additionally, bacteria of the phyla Proteobacteria, Firmicutes, and Actinobacteria were identified in meconium through molecular analysis, confirming the culture results and the early colonization of the newborn gut. Maternal, meconium and environmental samples had similar alpha diversity, while beta-diversity showed differences among families (i.e. a dam and her litter), and association indexes revealed a significant correlation between family members and between sample origin, suggesting a strong contribution of the maternal flora to the initial seeding of the canine neonatal gut and a strong individual dam imprint. CONCLUSION: This study showed that the meconium of vaginally delivered puppies has its own microbiota immediately after birth, and that it is shaped by the dam, which gives a specific imprint to her litter.

A common trajectory of gut microbiome development during the first month in healthy neonates with limited inter-individual environmental variations.

The early development of the gut microbiome is governed by multiple factors and has significantly long-term effects on later-in-life health. To minimize inter-individual variations in the environment, we determined developmental trajectories of the gut microbiome in 28 healthy neonates during their stay at a postpartum center. Stool samples were collected at three time points: the first-pass meconium within 24 h of life, and at 7 and 28 days of age. Illumina sequencing of the V3-V4 region of 16S rRNA was used to investigate microbiota profiles. We found that there was a distinct microbiota structure at each time point, with a significant shift during the first week. Proteobacteria was most abundant in the first-pass meconium; Firmicutes and Actinobacteria increased with age and were substituted as the major components. Except for a short-term influence of different delivery modes on the microbiota composition, early microbiome development was not remarkably affected by gravidity, maternal intrapartum antibiotic treatment, premature rupture of membranes, or postnatal phototherapy. Hence, our data showed a similar developmental trajectory of the gut microbiome during the first month in healthy neonates when limited in environmental variations. Environmental factors external to the host were crucial in the early microbiome development.

Impact of intrapartum antibiotic prophylaxis on the oral and fecal bacteriomes of children in the first week of life.

Intrapartum antibiotic prophylaxis (IAP) is commonly used during C-section delivery and in Group B Streptococcus-positive women before vaginal delivery. Here, we primarily aimed to investigate the effect of IAP on the neonatal oral and fecal bacteriomes in the first week of life. In this preliminary study, maternal and neonatal oral swabs and neonatal fecal (meconium and transitional stool) swabs were selected from a pool of samples from healthy mother-neonate pairs participating in the pilot phase of CELSPAC: TNG during their hospital stay. The DNA was extracted and bacteriome profiles were determined by 16S rRNA amplicon sequencing (Illumina). In the final dataset, 33 mother-neonate pairs were exposed to antibiotics during C-section or vaginal delivery (cases; +IAP) and the vaginal delivery without IAP (controls, -IAP) took place in 33 mother-neonate pairs. Differences in alpha diversity (Shannon index, p=0.01) and bacterial composition (PERMANOVA, p<0.05) between the +IAP and -IAP groups were detected only in neonatal oral samples collected ≤48 h after birth. No significant differences between meconium bacteriomes of the +IAP and -IAP groups were observed (p>0.05). However, the IAP was associated with decreased alpha diversity (number of amplicon sequence variants, p<0.001), decreased relative abundances of the genera Bacteroides and Bifidobacterium, and increased relative abundances of genera Enterococcus and Rothia (q<0.01 for all of them) in transitional stool samples. The findings of this study suggest that exposure to IAP may significantly influence the early development of the neonatal oral and gut microbiomes. IAP affected the neonatal oral bacteriome in the first two days after birth as well as the neonatal fecal bacteriome in transitional stool samples. In addition, it highlights the necessity for further investigation into the potential long-term health impacts on children.

Influencia del tipo de nacimiento sobre el contenido de bacterias acidolácticas en meconio de neonatos* / Influence from the type of birth on the content of lactic acid bacteria in neonate meconium

RESUMEN El objetivo del estudio fue determinar la influencia del nacimiento por vía vaginal en comparación con el nacimiento por cesárea sobre el contenido de bacterias acidolácticas con características probióticas de los recién nacidos. Se evaluaron muestras de meconio de recién nacidos por vía vaginal y por cesárea que fueron debidamente enriquecidas, sembradas e incubadas. Las colonias resultantes fueron identificadas para ser sometidas a tolerancia de sales biliares, pH ácido y fermentación. Se obtuvo un mayor desa rrollo de colonias en meconio de nacidos por vía vaginal en comparación con los nacidos por cesárea (p<0,001). Se aislaron 48 cepas en total, siendo en su gran mayoría tolerantes a sales biliares y pH ácido; asimismo, la fermentación de lactosa en leche fue positiva. Este estudio respalda hallazgos previos que sustentan que el nacimiento por vía vaginal favorece al mayor, desarrollo de bacterias acidolácticas con características probióticas, en comparación con el nacimiento por cesárea, y destaca la presencia de bac terias del género Lactobacillus.

ABSTRACT The study's objective was to determine the influence of vaginal birth compared to cesarean birth on the content of lactic acid bacteria with probiotic characteristics from newborns. Vaginal and cesarean sec tion meconium samples of lactic acid were evaluated, which were duly enriched, seeded and incubated. The resulting colonies were identified to be subjected to bile salt tolerance, acid pH, and fermentation. A greater development of meconium colonies was obtained in those born vaginally compared to those born by caesarean section (p <0.001). A total of 48 strains were isolated, the majority being tolerant to bile salts and acid pH; likewise, the fermentation of lactose in milk was positive. This study supports previous findings that support vaginal birth favors the greatest development of lactic acid bacteria with probiotic characteristics, compared to cesarean birth, and highlights the presence of bacteria of the genus Lactobacillus.

Rotavírus em recém-nascidos com menos de 24 horas de vida / Rotavirus in newborns with less than 24 hours of life

Durante 22 meses foram analisadas 687 amostras dentre fezes e mecônios de RN no berçário (grupo A - 236 amostras) e no ambulatório (grupo B - 451 amostras) do Hospital Universitário Antonio Pedro, da Universidade Federal Fluminense, para rotavírus, por ELISA, gel de poliacrilamida e microscopia eletrônica e bactérias. Verificou-se que os RN assintomáticos foram os únicos positivos (2,11% das amostras). Quando se confrontou freqüência de diarréia de mäes e bebês com o tipo de parto, näo houve correlaçäo entre os fenômenos. Houve predomínio de K. pneumoniae nos sintomáticos hospitalizados