Adult Fecal Samples Research Articles

Diversity Analysis of Intestinal Bifidobacteria in the Hohhot Population.

(1) Background: Bifidobacterium plays a pivotal role within the gut microbiota, significantly affecting host health through its abundance and composition in the intestine. Factors such as age, gender, and living environment exert considerable influence on the gut microbiota, yet scant attention has been directed towards understanding the specific effects of these factors on the Bifidobacterium population. Therefore, this study focused on 98 adult fecal samples to conduct absolute and relative quantitative analyses of bifidobacteria. (2) Methods: Using droplet digital PCR and the PacBio Sequel II sequencing platform, this study sought to determine the influence of various factors, including living environment, age, and BMI, on the absolute content and biodiversity of intestinal bifidobacteria. (3) Results: Quantitative results indicated that the bifidobacteria content in the intestinal tract ranged from 106 to 109 CFU/g. Notably, the number of bifidobacteria in the intestinal tract of the school population surpassed that of the off-campus population significantly (p = 0.003). Additionally, the group of young people exhibited a significantly higher count of bifidobacteria than the middle-aged and elderly groups (p = 0.041). The normal-weight group displayed a significantly higher bifidobacteria count than the obese group (p = 0.027). Further analysis of the relative abundance of bifidobacteria under different influencing factors revealed that the living environment emerged as the primary factor affecting the intestinal bifidobacteria structure (p = 0.046, R2 = 2.411). Moreover, the diversity of bifidobacteria in the intestinal tract of college students surpassed that in the out-of-school population (p = 0.034). This was characterized by a notable increase in 11 strains, including B. longum, B. bifidum, and B. pseudolongum, in the intestinal tract of college students, forming a more intricate intestinal bifidobacteria interaction network. (4) Conclusions: In summary, this study elucidated the principal factors affecting intestinal bifidobacteria and delineated their characteristics of intestinal bifidobacteria in diverse populations. By enriching the theory surrounding gut microbiota and health, this study provides essential data support for further investigations into the intricate dynamics of the gut microbiota.

Gut microbiota develop towards an adult profile in a sex-specific manner during puberty

Accumulating evidence indicates that gut microbiota may regulate sex-hormone levels in the host, with effects on reproductive health. Very little is known about the development of intestinal microbiota during puberty in humans. To assess the connection between pubertal timing and fecal microbiota, and to assess how fecal microbiota develop during puberty in comparison with adult microbiota, we utilized a Finnish allergy-prevention-trial cohort (Flora). Data collected at 13-year follow-up were compared with adult data from a different Finnish cohort. Among the 13-year-old participants we collected questionnaire information, growth data from school-health-system records and fecal samples from 148 participants. Reference adult fecal samples were received from the Health and Early Life Microbiota (HELMi) cohort (n = 840). Fecal microbiota were analyzed using 16S rRNA gene amplicon sequencing; the data were correlated with pubertal timing and compared with data on adult microbiota. Probiotic intervention in the allergy-prevention-trial cohort was considered as a confounding factor only. The main outcome was composition of the microbiota in relation to pubertal timing (time to/from peak growth velocity) in both sexes separately, and similarity to adult microbiota. In girls, fecal microbiota became more adult-like with pubertal progression (p = 0.009). No such development was observed in boys (p = 0.9). Both sexes showed a trend towards increasing relative abundance of estrogen-metabolizing Clostridia and decreasing Bacteroidia with pubertal development, but this was statistically significant in girls only (p = 0.03). In girls, pubertal timing was associated positively with exposure to cephalosporins prior to the age of 10. Our data support the hypothesis that gut microbiota, particularly members of Ruminococcaceae, may affect pubertal timing, possibly via regulating host sex-hormone levels.Trial registration The registration number for the allergy-prevention-trial cohort: ClinicalTrials.gov, NCT00298337, registered 1 March 2006—Retrospectively registered, https://clinicaltrials.gov/show/NCT00298337. The adult-comparison cohort (HELMi) is NCT03996304.

Comparative Assessment of Antibiotic Resistance in Lactic Acid Bacteria Isolated from Healthy Human Adult and Infant Feces

Lactic acid bacteria are normal inhabitants of the gastrointestinal tract of humans. Their occurrence in infant and adult feces is abundant. The current study assesses and compares the antibiotic resistance in lactic acid bacteria isolated from healthy human adult and healthy infant fecal samples. A total of 255 lactic acid bacteria isolates (126 from adult feces and 129 from infant feces) were isolated and characterized from 60 fecal samples. Lactobacillus spp., Pediococcus spp. and Enterococcus spp. were included in the study. The study was done using the WHONET software for the analysis of antibiotic susceptibility data of lactic acid bacteria. Most of the Lactobacillus and Pediococcus strains were sensitive to vancomycin. Enterococcus strains showed resistance against vancomycin. Ampicillin, ciprofloxacin and cefuroxime resistance were significantly (p<0.05) higher in Lactobacillus strains isolated from adult fecal samples than those isolated from infant fecal samples. A similar pattern was observed in Enterococcus strains with erythromycin, gentamycin and tobramycin resistance. Pediococcal isolates from adult feces showed significantly higher resistance against tobramycin, ciprofloxacin, gentamycin, cefotaxime and cefuroxime in comparison with infant fecal isolates. Antibiotic resistance was exhibited by lactic acid bacteria against most commonly used antibiotics and it was higher in strains isolated from adult fecal samples than in the strains isolated from infant fecal samples. The increasing trend in antibiotic resistance from infant to adult might be due to food habits and antibiotic intakes. Thus, the widespread antibiotic resistance in different lactic acid bacteriamay pose a food safety concern as well.

Midtrimester amniotic fluid from healthy pregnancies has no microorganisms using multiple methods of microbiologic inquiry

There is controversy about whether the amniotic fluid contains bacteria. With the use of sequencing-based methods, recent studies report that the amniotic fluid is colonized by microorganisms. However, background-contaminating DNA might lead to false-positive findings when such a low microbial biomass sample is examined. The purpose of this study was to determine whether the midtrimester amniotic fluid of patients who subsequently had normal pregnancy outcomes contains a microbial signature. In this prospective cohort study, 42 amniotic fluid samples were collected from 37 pregnancies (5 twin and 32 singletons) during genetic amniocentesis in the midtrimester. The subsequent pregnancy outcomes of all the participants were followed. Multiple methods were used to detect the presence of microorganisms in this study, which included cultivation, quantitative real-time polymerase chain reaction, and 16S ribosomal RNA gene sequencing. Multiple positive control samples (n=16) served as quality control samples and included 3 adult fecal samples, 4 vaginal swabs, and 9 artificial bacterial communities that were run in parallel with negative control samples (n=12) that included 4 samples from the hospital operating room and 8 samples from the laboratory, to account for background-contaminating DNA during each step of the experiments. No bacteria under anaerobic or aerobic conditions or genital mycoplasmas were cultured from any of the amniotic fluid samples. Quantitative polymerase chain reaction did not reveal greater copy numbers of 16S ribosomal RNA gene in amniotic fluid samples than in negative control samples. 16S Ribosomal RNA gene sequencing did not indicate a significant difference in the microbial richness or community structures between amniotic fluid and negative control samples. With multiple methods of microbiologic inquiry, no microorganisms were identified in the midtrimester amniotic fluid of healthy pregnancies with a normal pregnancy outcome.

Plant species identification using fecal DNAs from red-eared slider and Reeves’ pond turtle in agricultural canals for rural ecosystem conservation

Fecal DNA samples from the red-eared slider and Reeves’ pond turtle, suspected pests of lotus root paddies, were used to identify the plant species eaten by these turtles in order to develop a strategy for rural ecosystem conservation. The fecal samples were obtained from young and adult individuals (mostly female) of both species living in agricultural canals surrounding lotus root paddies in Tokushima Prefecture, Japan. The samples were screened for the presence or absence of DNA from nine plant species using PCR and plant species-specific primers for the rbcL gene of chloroplast DNA. In the red-eared slider, our analysis identified seven plant species in the fecal DNA samples of adults and three plant species in those of young individuals. In Reeves’ pond turtle, our analysis identified two plant species from adult fecal samples and one species from those of young individuals. Thus, adult red-eared sliders consume a greater range of plants than young red-eared sliders or Reeves’ pond turtles. Both turtle species, independently of age, consumed lotus plants and were likely to cause feeding damage to lotus roots. Considering the plant species detected in adult red-eared sliders and these plant habitats, we suggest that this adult turtle is likely to travel between the agricultural canals and the lotus root paddies. These findings will help the development of strategies for preventing damage to lotus roots by these turtles; furthermore, they indicate that fecal DNA analysis will be applicable to investigation of the feeding habits of other animal species.

Diarrheagenic pathogens in adults attending a hospital in Singapore.

BackgroundSingapore’s diarrhoeal notification system is based on specific pathogens. Official data may thus be skewed towards notifiable diseases. Limited information is available on the profiles of aetiological agents responsible for acute gastroenteritis (AGE) cases, especially among the adult population. To understand the frequency and distribution of potential causative agents of diarrheal disease in Singapore, we screened adults’ stool samples collected from a large public hospital.MethodsThe stool samples were screened for 18 diarrheagenic pathogens using a combination of commercial multiplex polymerase chain reaction (PCR), in-house singleplex PCR and immunochromatographic assays. One hundred adult faecal samples that were collected from October 2013 to January 2014 for routine diagnostic purposes and submitted for culture at Tan Tock Seng Hospital, Singapore were used.ResultsPathogens were detected in 32 % of the samples. The predominant organisms encountered were norovirus genogroup II (11 %), Aeromonas spp. (9 %) and Campylobacter spp. (5 %). One sample was positive for both verocytotoxigenic E. coli (VTEC) and E. coli O157:H7. Two other samples were positive for VTEC only, and one other sample was positive for E. coli O157:H7 only. Astrovirus, C. perfringens, Shigella spp. and toxigenic C. difficile were each detected in 2 % of the samples. Cryptosporidium parvum, Giardia lamblia, group A rotavirus, Salmonella spp. and Vibrio spp. were each detected in 1 % of the samples. No L. monocytogenes, Y. enterocolitica, enteric adenovirus, or norovirus genogroup I were detected.ConclusionOur preliminary findings suggest that pathogens causing non-notifiable diseases might have contributed considerably to the adult hospitalised AGE cases. However, as the samples were from an adult hospital, the data obtained may not be representative of the whole community. Thus, a larger study to collect clinical samples and risk exposure data from primary healthcare clinics and children hospital is planned for, to gain a more holistic perspective on the epidemiology of AGE in Singapore. A larger study may also offer valuable insights for improving the approach of microbiological surveillance of food, as well as strategizing inspection efforts along the food supply chain by public health authorities.

The Omnivorous Diet of the Western Chicken Turtle (Deirochelys reticularia miaria)

Chicken Turtles (Deirochelys reticularia) are morphologically adapted for carnivory, and this specialization has been corroborated by diet studies of the eastern and Florida subspecies (D. r. reticularia and D. r. chrysea, respectively). However, the diet of the western subspecies (D. r. miaria) has not been examined. To investigate this important aspect of this subspecies' ecology, we collected 54 fecal samples from 22 adult D. r. miaria and 13 samples from nine juvenile D. r. miaria in southeastern Oklahoma. White River Crayfish (Procambarus acutus) were found in 88.9% of adult samples (mean of 2.3 crayfish per sample), and appeared to be the dominant food source for adults. There was a significant positive relationship between turtle size and crayfish size, and on average the crayfish were 29.8 mm in carapace length. Insects representing six orders (predominantly Hemiptera and Coleoptera) were found in 57.4% of adult fecal samples. Surprisingly, plants were present in 92.6% of adult fecal samples. While most of the plant matter was unidentifiable, Common Rush (mostly seeds; Juncus effusus), Broadleaf Cattail (Typha latifolia), Giant Cutgrass (seeds; Zizaniopsis miliacea), and Purple-fringed Riccia (Ricciocarpus natans) were identified in several fecal samples. There was a significant difference between the diets of juveniles and adults, with juveniles consuming more insects, fewer crayfish, and fewer plants than adults. These results suggest both that there is an ontogenetic shift in the diet of D. r. miaria and that, unlike the other subspecies, D. r. miaria is demonstrably omnivorous.

Quantification of Human Fecal Bifidobacterium Species by Use of Quantitative Real-Time PCR Analysis Targeting the groEL Gene

Quantitative real-time PCR assays targeting the groEL gene for the specific enumeration of 12 human fecal Bifidobacterium species were developed. The housekeeping gene groEL (HSP60 in eukaryotes) was used as a discriminative marker for the differentiation of Bifidobacterium adolescentis, B. angulatum, B. animalis, B. bifidum, B. breve, B. catenulatum, B. dentium, B. gallicum, B. longum, B. pseudocatenulatum, B. pseudolongum, and B. thermophilum. The bifidobacterial chromosome contains a single copy of the groEL gene, allowing the determination of the cell number by quantification of the groEL copy number. Real-time PCR assays were validated by comparing fecal samples spiked with known numbers of a given Bifidobacterium species. Independent of the Bifidobacterium species tested, the proportion of groEL copies recovered from fecal samples spiked with 5 to 9 log(10) cells/g feces was approximately 50%. The quantification limit was 5 to 6 log(10) groEL copies/g feces. The interassay variability was less than 10%, and variability between different DNA extractions was less than 23%. The method developed was applied to fecal samples from healthy adults and full-term breast-fed infants. Bifidobacterial diversity in both adults and infants was low, with mostly ≤3 Bifidobacterium species and B. longum frequently detected. The predominant species in infant and adult fecal samples were B. breve and B. adolescentis, respectively. It was possible to distinguish B. catenulatum and B. pseudocatenulatum. We conclude that the groEL gene is a suitable molecular marker for the specific and accurate quantification of human fecal Bifidobacterium species by real-time PCR.

An outbreak of diarrhoea associated with rotavirus serotype 1 in a day care nursery in Rio de Janeiro, Brazil.

Faeces from 17 children less than 1.6 years old and 15 adults more than 22 years old were collected during an outbreak of gastroenteritis in a day care nursery and screened for the presence of adenovirus and rotavirus by enzyme immunoassay (EIARA) and other viruses by electron microscopy (EM) and polyacrylamide gel electrophoresis (PAGE). Ten samples (58.8%) from children and one (6.7%) from adults were positive for rotavirus and all samples were negative for bacteria and parasites. No other viruses were observed in EM. An enzyme immunoassay test using monoclonal antibodies (MAb-EIA) to determine the subgroup(s) and the serotype(s) of rotavirus was performed and the results showed that all positive samples belong to serotype 1, subgroup II of group A rotaviruses. In PAGE test all samples had the same profile and the 10 and 11 dsRNA segments corresponded to the "long" profile of group A of rotaviruses. These results corroborated the MAb-EIA results and indicate a sole source of infection. The major symptoms observed were: vomiting (60%), fever (70%) and diarrhoea (100%). In previous years (1989 to 1991) we observed only rotavirus serotype 2 in this same day care nursery, but no outbreak was reported.