16S RNA Gene Research Articles

Rizobacterias aisladas de Jatropha curcas L.: actividad antagonista de fitopatógenos y promotora del crecimiento de plantas

Introduction:Jatropha curcas L. is a species native to Mexico that has recently been considered an important crop to produce biofuel. Objective: To isolate and identify rhizobacteria from J. curcas with antagonistic activity against phytopathogenic fungi (Curvularia lunata and Fusarium equiseti) of this crop and evaluate their capacity to promote tomato plant growth. Materials and methods: The isolates were obtained by serial dilution and antagonistic activity was assessed by volatile and diffusible compounds on PDA medium. In addition, the production of antifungal compounds and metabolites that promote the plant growth were determined. The isolates were identified by amplifying the 16S RNA and sodA genes. Finally, the isolates were inoculated on tomato seeds to evaluated plant growth promotion and germination. Results and discussion: The antagonistic bacteria were identified as Bacillus mojavensis, Bacillus subtilis, Bacillusthuringiensis, and Pseudomonas aeruginosa. The antifungal effect on the mycelial growth of C. lunata and F. equisetiwas due to the presence of volatile and diffusible compounds with between 30 % and 79 % inhibition. Pseudomonas aeruginosa showed the strongest inhibitory effect (48.7 to 79.8 %). Bacillus subtilis (A1), B. mojavensis (A4) and B. thuringiensis (A6, A8) showed the highest germination (70 % to 88 %). The vegetative growth of tomato plants treated with the isolates was significantly higher than the controls(P < 0.05). Conclusion: Eight rhizobacteria isolated from J. curcas showed antagonistic activity against C. lunata and F. equiseti and demonstrated their capacity to improve the germination and promote growth in tomato plants

Cadmium (Cd) and Lead (Pb) Uptake Potential and Surface Properties of Aeromonas spp. Isolated from Soil of Local Mining Site

Aim: In this study, Aeromonas spp. isolated from soil of local mining sites were assessed for their tolerance to some heavy metals and their capability for its uptake.
 Materials and Methods: The bacteria were isolated from soil of local mining site in Bagega District of Zamfara State in Nigeria. Maximum Tolerable Concentration (MTC) was employed to screen for metal tolerance of the bacteria to Cadmium (Cd) and Lead (Pb) via Agar Plate Method technique. DNA Extraction and 16sRNA Gene Sequence Analysis was carried out to identify the isolates and sequences were compared to those in NCBI database using Basic Local Alignment Search Tool (BLAST).
 Results: Similarly, isolates identified were further characterized and validated by subjecting them to 16sRNA gene sequence analysis. Similarity search indicated a close genetic relatedness to Aeromonas spp. in NCBI database. The Aeromonas spp. Identified showed maximum tolerance to Pb at 27ppm and Cadmium at 24ppm. Bioaccumulation assay carried out revealed Aeromonas sp. BDL2 to take up Pb by as high as 70%. Biosorption capacity of their respective dried biomass assayed showed higher Pb uptake at 95.9% for Aeromonas sp. BDL2. Statistical analysis revealed a significant difference (P≤0.05) between the isolates and their respective biomass in the uptake Pb and Cd. Surface examination different bands indicated the presence of carboxyl, amine, amides, sulfates and other aromatic groups and significant shifts of surface molecules.
 Conclusion: Aeromonas sp. BDL2 identified in this study exhibited higher tolerance to Pb. Surface molecules and their positional properties revealed the presence of hydroxyl, carboxyl, amine and amide group ligands with significant shifts after accumulation and biosorption experiment suggesting interaction between these surface molecules and heavy metal ions.

IMPACT OF ENDOPHYTIC LIPOPEPTIDES USE AGAINST SOME PLANT PATHOGENIC MICROORGANISMS

Twelve dissimilar plant associated bacterial colonies were isolated from five different tomato seedlings, the Non Ribosomal Lipopeptides genes were detected by degenerated primers technique in the twelve tomato endophytic isolates, only the long rode bacilli endophytic strains were found to harbour the lipopeptides synthetases genes, these three strains were given laboratory names of (BMG100, BMG101 and BMG102) for further pursuit. Partial sequencing of 16s RNA gene and protein profile analysis for the three bacilli isolates showed that all isolates belonged to Bacillus subtilis. The lipopeptides production by HPLC analysis revealed that all the endophytic isolates from tomato stems had the ability to produce lipopeptides except the third isolate named B. subtilis BMG102 showed no production. different levels of volumetric oxygen transfer coefficient (KLa) were used as cursors for lipopeptides production. The maximum concentration of surfactin type was about 1431, 529 and 437 mg.L-1, the plipastitin (fengycin type ) was 360 198 mg.L-1 and zero while the Mycosubtilin (iturin type) was zero, 228 and 414 mg.L-1 for the strains B. subtilis ATCC21332, BMG100 and BMG101, respectively. Surfactin production is visibly optimal at high oxygen transfer (kLa) and showed more than 0.07 S-1, while the optimum production of the fengycin and iturin could be observed at mild values of O2 transfer (kLa) which equal 0.01 and 0.015 S-1 respectively. The antibacterial - antifungal effects of the three B.subtilis extracts collected during lipopeptides productivity regimes showed inhibition activity against Pseudomonas syringae, Ralstonia solanacearum and Erwinia amylovora, as will as the antifungal activity against Aspergillus niger, Phanerochaete chrysosporium and Alternaria alternata. These results indicate potential use of B.subtilis strains as biocontrol agents, especially when considering commercial implementation. Studies regarding the lipopeptides applications, should also be considered as this will influence the efficacy of the lipopeptides against the target organisms.

A Validated Multiplex Real-Time PCR Assay for the Diagnosis of Infectious Leptospira spp.: A Novel Assay for the Detection and Differentiation of Strains From Both Pathogenic Groups I and II.

Leptospirosis is recognized as the most globally widespread reemerging zoonosis and represents a serious threat for both human and animal health. Indeed, leptospirosis is linked to more than 60,000 human deaths per year and to incalculable economic burden as consequence of medical treatment costs and livestock loss. The increasing number of reports from species of pathogenic Leptospira spp. group II causing disease in both humans and animals constitutes an additional concern to the complex epidemiology of this zoonotic agent. Diagnostic methods based on qPCR have improved the diagnosis of Leptospira spp. in terms of cost, time, and reliability, but most of the validated assays fail to detect species from the pathogenic group II. Hence, the current study was aimed to develop and validate a novel multiplex qPCR to enable the specific and selective detection of the whole group of infectious Leptospira spp., including both pathogenic groups I and II and moreover, selectively discriminate between them. To fit the “fitness of purpose” for the specific detection of infectious Leptospira spp. and further discrimination between both pathogenic groups three target regions on the 16S RNA gene were selected. These targets facilitated a broad and selective spectrum for the detection of all infectious Leptospira spp. with the exclusion of all saprophytic groups and the novel clade of environmental Leptospira spp. The analytical sensitivity (ASe) showed by the new assay also enables a wide window of detection for the agent at different stages of infection since the assay was able to efficiently detect at 95% of confidence ∼5 leptospires/reaction. From the evaluation of the analytical specificity (ASp) by in silico and in vitro approaches, it was congruently revealed that the primers and probes selected only recognized the specific targets for which the assay was intended. Bayesian latent class analysis of performance of the new assay on 684 clinical samples showed values of diagnostic sensitivity of 99.8% and diagnostic specificity of 100%. Thus, from the evaluation of the analytical and diagnostic parameters, the new multiplex qPCR assay is a reliable method for the diagnosis of Leptospira spp.

Development of a species-specific PCR coupled with lateral flow immunoassay for the identification of goose ingredient in foods

Meat authenticity testing along food supply chain can be largely improved through fast and integrated DNA-based identification methods. A species-specific polymerase chain reaction (PCR) coupled with lateral flow immunoassay (LFI) was developed for the identification of goose meat. The goose-specific primers that could specifically enrich a fragment on mitochondrial 12s RNA gene were successfully designed. The specificity of the primers was verified against 19 other species associated with meat fraud. The proposed PCR-LFI device was able to detect 0.01% (w/w) of goose in uncooked binary mixtures and 0.1% (w/w) in cooked binary mixtures. The LFI strip as a post-PCR visualization method was more sensitive and faster than gel electrophoresis method. Eight collaborative laboratories verified the reproducibility of fabrication and detection protocols of the developed LFI. This PCR-LFI method has great potential to be used as a fast and cost-efficient counter-measure for food industry and other regulatory bodies to reduce the possibility of fraud of goose products.

Linezolid resistance in Enterococcus faecium and Enterococcus faecalis from hospitalized patients in Ireland: high prevalence of the MDR genes optrA and poxtA in isolates with diverse genetic backgrounds.

ObjectivesTo investigate the prevalence of the optrA, poxtA and cfr linezolid resistance genes in linezolid-resistant enterococci from Irish hospitals and to characterize associated plasmids.MethodsOne hundred and fifty-four linezolid-resistant isolates recovered in 14 hospitals between June 2016 and August 2019 were screened for resistance genes by PCR. All isolates harbouring resistance genes, and 20 without, underwent Illumina MiSeq WGS. Isolate relatedness was assessed using enterococcal whole-genome MLST. MinION sequencing (Oxford Nanopore) and hybrid assembly were used to resolve genetic environments/plasmids surrounding resistance genes.Results optrA and/or poxtA were identified in 35/154 (22.7%) isolates, the highest prevalence reported to date. Fifteen isolates with diverse STs harboured optrA only; one Enterococcus faecium isolate harboured optrA (chromosome) and poxtA (plasmid). Seven Enterococcus faecalis and one E. faecium harboured optrA on a 36 331 bp plasmid with 100% identity to the previously described optrA-encoding conjugative plasmid pE349. Variations around optrA were also observed, with optrA located on plasmids in five isolates and within the chromosome in three isolates. Nine E. faecium and 10 E. faecalis harboured poxtA, flanked by IS1216E, within an identical 4001 bp region on plasmids exhibiting 72.9%–100% sequence coverage to a 21 849 bp conjugative plasmid. E. faecalis isolates belonged to ST480, whereas E. faecium isolates belonged to diverse STs. Of the remaining 119 linezolid-resistant isolates without linezolid resistance genes, 20 investigated representatives all harboured the G2576T 23S RNA gene mutation associated with linezolid resistance.ConclusionsThis high prevalence of optrA and poxtA in diverse enterococcal lineages in Irish hospitals indicates significant selective pressure(s) for maintenance.

Temperature potentially induced distinctive flavor of mud crab Scylla paramamosain mediated by gut microbiota

Many factors affect the flavor of crabs. However, impact of temperature on flavor has not been reported. Here, we examined Scylla paramamosain collected within the main four producing areas in China from north sampling point (NP) and south sampling point (SP), respectively. The contents of flavouring-related substances in hepatopancreas, muscles and gonads were determined by high-performance liquid chromatography (HPLC). Meanwhile, high-throughput sequencing of 16S RNA gene was used to reveal the diversity distribution of gut microbiota at each sample collection point. Comparisons among flavor substances of edible parts, the implied higher temperature in SP may be beneficial to the accumulation of flavor substances in gonads, while lower temperature in NP may be beneficial to the accumulation of flavor substances in muscles and hepatopancreas. The gut microbiota of crabs, was analyzed via 16S rRNA gene sequencing. The results of gut microbiota showed that there were significant differences in the distribution of gut microbiota in NP and SP. The microbiota composition of SP has a high distribution richness and no absolute dominant bacteria, while NP has absolute dominant bacteria and its microbiota richness was lower than SP. The results of redundancy analysis (RDA) showed that there was a significant correlation between temperature and the relative abundance of gut microbiota, and a significant correlation between gut microbiota and the content of flavor substances. This study indicates that temperature may be one of the main factors for the differences of flavor substances between SP and NP, which was most probably mediated by gut microbiota. Further exploration is needed with laboratory experiments in which the environment is more precisely controlled if these views are to be determined.

Phytophthora Antagonism of Endophytic Bacteria Isolated from Roots of Black Pepper (Piper nigrum L.)

In this study, 90 root samples were collected from 30 black pepper farms in three provinces in the Central Highlands of Vietnam. A total of 352 endophytic bacteria were isolated and their morphology described. An in vitro assay on the antifungal activity of these isolates was then conducted and 47 isolates were found to have antagonistic activity on Phytophthora fungi. The antifungal activity of the 47 isolates was evaluated in vivo by shoot assay. Among these 47 isolates, 6 were selected for further investigation. The six isolates were classified and identified by sequencing the 16S RNA gene and phylogeny. The results showed that all six endophytic bacteria belong to the following species of Bacillus genus: B. siamensis, B. amyloliquefaciens, B. velezenis, and B. methylotrophiycus. Enzymatic activity related to the antifungal activity of the six potent isolates was determined; it showed that they possessed high chitinase and protease activities. These isolates were applied for black pepper seedlings in greenhouse. The results showed three promising isolates: B. siamensis EB.CP6, B. velezensis EB.KN12, and B. methylotrophycus EB.KN13. Black pepper seedlings treated with the promising bacteria had the lowest rate of root disease (8.45–11.21%) and lower fatal rate (11.11–15.55%) compared to the control group (24.81% and 24.44%). In addition, the three promising isolates strongly affected the growth of the black pepper seedlings in greenhouse. The plant height, length of roots, and fresh biomass of the seedlings in the treated plots were higher than those in the control plots. Thus, the endophytic bacterial isolates have the potential to act as biocontrol agent for the sustainable production of black pepper.

Dissimilarity of the gut-lung axis and dysbiosis of the lower airways in ventilated preterm infants.

BackgroundChronic lung disease of prematurity (CLD), also called bronchopulmonary dysplasia, is a major consequence of preterm birth, but the role of the microbiome in its development remains unclear. Therefore, we assessed the progression of the bacterial community in ventilated preterm infants over time in the upper and lower airways, and assessed the gut–lung axis by comparing bacterial communities in the upper and lower airways with stool findings. Finally, we assessed whether the bacterial communities were associated with lung inflammation to suggest dysbiosis.MethodsWe serially sampled multiple anatomical sites including the upper airway (nasopharyngeal aspirates), lower airways (tracheal aspirate fluid and bronchoalveolar lavage fluid) and the gut (stool) of ventilated preterm-born infants. Bacterial DNA load was measured in all samples and sequenced using the V3–V4 region of the 16S rRNA gene.ResultsFrom 1102 (539 nasopharyngeal aspirates, 276 tracheal aspirate fluid, 89 bronchoalveolar lavage, 198 stool) samples from 55 preterm infants, 352 (32%) amplified suitably for 16S RNA gene sequencing. Bacterial load was low at birth and quickly increased with time, but was associated with predominant operational taxonomic units (OTUs) in all sample types. There was dissimilarity in bacterial communities between the upper and lower airways and the gut, with a separate dysbiotic inflammatory process occurring in the lower airways of infants. Individual OTUs were associated with increased inflammatory markers.ConclusionsTaken together, these findings suggest that targeted treatment of the predominant organisms, including those not routinely treated, such as Ureaplasma spp., may decrease the development of CLD in preterm-born infants.

English

Seafood is part of a healthful diet, but seafood consumption is not risk-free because of sea contaminations by anthropogenic activities and environmental factors. Their microbiological quality is of major concern to the food processors, consumers and public health authorities hence the need for proper assessment of the microbial quality. This study therefore characterizes pathogenic microorganisms isolated from fresh sea snail and shrimp in Ugbo nla, Igbokoda, Ondo State, Nigeria. Isolation and molecular identification of microorganisms from snail and shrimp using 16sRNA and 18sRNA gene sequence for bacteria and fungi respectively, effects of salt concentration and temperature on isolated microorganisms were carried out using standard microbiological methods. Molecular identification revealed the presence different pathogens namely; Proteus mirabilis LZPM-03, Pantoea agglomerans BJCP2, Pseudomonas aeruginosa R8-589, Klebsiella pneumoniae 2N3, Serratia marcescens, Alcaligenes faecalis ACBC1, Yersinia. pseudotubercules YPIII, Escherichia coli 2A, Lysinibacillus sphaericus C3-41, Listeria monocytogen J1776, Staphylococcus aureus and Proteus mirabilis LCX20, Fusarium proliferatum FproStRINI, Aspergillus flavus NRRL3357, Aspergillus oryzae RIB40 and Aspergillus peniciliodes. Also, 4% salt concentration at 45°C effectively inhibited the pathogens isolated from seafood after 18 h. The presence of pathogenic microorganisms in the sea foods could make them a potential health-risk when consumed without proper cooking. Salting, a traditional technique could be used to eliminate these pathogens before consumption.   Key words: Seafood, molecular identification and salt concentration. &nbsp

Identifying predictors of early childhood caries among Australian children using sequential modelling: Findings from the VicGen birth cohort study

ObjectivesThe aim of this birth cohort study was to identify concurrent associations between early childhood caries and putative risk and protective factors. MethodsData were collected in seven waves over five years. The study outcome measure, d3-6mfs, was modelled in a set of sequential negative binomial regressions that introduced the variables in steps starting from health determinants most distal to the child and ending with the more proximal ones. The goodness of fit of each model at each step was tested using the quasi-likelihood under independence model criterion (QIC). A final model included all significant factors identified in the sequential modelling. Bacterial composition of the child’s saliva was determined by 16S RNA gene sequencing. ResultsOverall, 467 children (48.6 % female) participated, of whom 419 (89.7 %) had at least one follow-up visit after baseline. Of the 419 children included in the analyses, 133 (31.7 %) had their saliva samples sequenced for microbiomic determination. Independent protectors of surface cavitation included water fluoridation, and older age of mothers. Risk for d3-6mfs was significantly higher among children whose mothers were current smokers (IRR 3.29, 95 % CI 1.09–9.88, p = 0.034), children who went to bed with a bottle (IRR 2.67, 95–6.88, p = 0.041) and whose saliva sample sequencing over time showed higher percentages of Streptococcus mutans (IRR 1.39, 95 % CI 1.11–1.74, p = 0.005). Model fit was mostly improved by child’s proximal variables. Household and mother covariates did not substantially improve model fit. ConclusionThis analysis highlights the relevance and importance of child-proximal risk factors in childhood dental cavitation. Clinical significanceThe study findings inform clinical decision making for the management of early childhood caries at both the individual and population level. At an individual and family level these risk factors should be incorporated into caries risk assessment tools for more precise identification of risk and evidence-informed interventions by health professionals.

Safety Assessment of Indigenous Probiotic Strain Lactobacillus plantarum Mut-7 Using Sprague Dawley Rats as a Model

Lactobacillus plantarum Mut-7 is a probiotic candidate isolated from gatot, traditional fermented cassava from Java, Indonesia. This study aimed to evaluate safety aspects of high dose consumption of L. plantarum Mut-7 (1011 CFU/ml/day) on Sprague Dawley rats for 21 days. Twenty four female rats were randomly divided into 4 groups; initial condition group (P.0), control group (P.1), skim milk group (P.2) and probiotics group (P.3). All groups followed adaptation phase of 7 days, followed by treatment phase of 21 days for P.1, P.2 and P.3. The results showed that supplementation of high dose of L. plantarum Mut-7 did not have detrimental effects on general health, organ weight, hematology and histology parameters of treated rats. Feed intake and body weight showed no significant difference between groups. L. plantarum Mut-7 can survive in gastrointestinal tract of rats, resulting in an increased population of L. plantarum in the fecal matter and the digesta of treated rats. Bacterial translocation of L. plantarum Mut-7 was not detected in the blood and organ of treated rats as confirmed by rep-PCR with BOXAIR primer and further 16S RNA gene sequencing analysis. Twenty-six isolates from blood and organs of treated rats had low-level similarity (<75%) to that of L. plantarum Mut-7, with 10 isolates were further analyzed and found that none of them belong to L. plantarum. Although this study was limited to the use of animal study, the findings are useful to support the safety assessment of the use of L. plantarum Mut-7 as a probiotic according to the abovementioned parameters.

Analysis of bacterial communities of infected primary teeth in a Mexican population.

Background The objective of this study was to describe the bacterial communities associated with pediatric patients with endodontic infections of temporal teeth by targeting the 16S rRNA gene using pyrosequencing. Material and Methods Microbiological samples were obtained from the lower primary molars of thirteen 13 pediatric patients with dental infections. An aspiration method for microbiological sampling was used. The identification of microbiota employing the pyrosequencing method by targeting the 16S gene was performed. Results Ribosomal 16S RNA gene sequences were amplified, obtaining a total of 16,182 sequences from 13 primary infected molars (13 different individuals) by pyrosequencing. Bacteroidetes phyla (35.15%) were the most abundant followed by Firmicutes (33.3%) and Fusobacteria (10.05%); the presence of specific pathogenic bacteria was determined as well. Conclusions The infected root canal of primary teeth contains a high diversity of anaerobic bacteria, and Bacteroidetes, Firmicutes, and Fusobacteria phyla were the most abundant; Prevotella and Streptococcus genera were the most prevalent. Key words:Pyrosequencing, deciduous teeth, oral bacterial microbiota, 16S rRNA, taxonomy.

Obesity status may intervene in the relation between dietary fiber intake and gut microbiota diversity

AbstractHigh diversity is considered a property of gut microbiota that is beneficial for human health. A higher dietary fiber intake has been shown to increase gut microbiota diversity. Similarly, there is preliminary evidence that an excess adiposity relates to low diversity. Our objective was to investigate the relationship between dietary fiber intake and gut microbiota diversity whilst considering the overweight and obesity status. Overweight (n = 52, prepregnancy BMI ≥ 25 kg/m2) and obese (n = 47, BMI ≥ 30 kg/m2) women were studied in early pregnancy (a mean of 13 weeks of gestation). The mean daily fiber intake (g) was calculated from 3-day food diaries by computerized software. To evaluate the gut microbiota α-diversity we determined the divergence-based measure, phylogenetic diversity (PD), and the qualitative and quantitative species-based measures, Chao 1 and Shannon index, from 16S RNA gene sequencing using QIIME pipeline. Dietary fiber intake (mean ± SD: 19.7 ± 6.2 g) correlated directly with PD (rho = 0.33, P = 0.002) and Chao 1 index (rho = 0.31, P = 0.004), but not with Shannon index (rho = 0.20, P = 0.06) in all women. Instead, no correlation between BMI and microbiota diversity indexes were seen, except for obese women in whom the BMI correlated inversely with PD (rho = -0.31, P = 0.04). Interestingly, distinct associations between fiber intake and microbiota diversity were detected in overweight and obese women. Fiber intake correlated directly with PD (rho = 0.34, P = 0.02 vs. rho = 0.32, P = 0.04), the measure depicting the phylogenetic branch length, in both overweight and obese women, the correlation with Chao 1 (rho = 0.35, P = 0.02), which depicts the presence or absence of each taxon i.e. richness, was seen only in obese women. Nevertheless, no correlation was seen between fiber intake and Shannon index (rho = -0.004, P = 0.98 vs. rho = -0.18, P = 0.25), the measure depicting the presence and absence as well as the abundance of each taxon i.e. richness and evenness, either in overweight or obese pregnant women. We found direct correlations between dietary fiber intake and gut microbiota α-diversity but obesity status intervened in this relation. In contrast to overweight women, in obese women, the higher dietary intake was reflected in a higher gut microbiota diversity measured at the level of taxon richness, suggesting that particularly obese pregnant women may benefit from a higher dietary fiber intake.

Microbial Inhibition by Bacteria Isolated from Pallial Cavity Fluids and Associated Mucus of the Eastern Oyster Crassostrea virginica (Gmelin)

Thirteen aerobic, mesophilic marine bacterial strains were isolated from the pallial (mantle) cavity fluids and associated mucus of the eastern oyster Crassostrea virginica Gmelin. All strains were Gram-negative and identified to genus using 16S RNA gene sequence analysis. Each isolated strain was tested for its ability to inhibit growth of six Gram-negative and five Gram-positive bacterial tester strains, as well as the yeast Candida albicans, using an in vitro agar diffusion screening method to detect antimicrobial activity (Romenenko et al. 2008). All of the marine bacteria isolated from the oyster pallial cavity fluids showed some ability to inhibit tester strains. Two isolates, F (red) and M, inhibited the greatest variety of indicator strains and produced the largest zones of inhibition. Gram-negative indicator strains were more susceptible to antimicrobial activity of pallial fluid isolates than Gram-positive strains. None of the isolated bacteria was shown to inhibit C. albicans. In addition, targeted 16S metagenome libraries from the Chesapeake Bay were screened for the presence of bacteria isolated from this study. Results indicate that there are commonalities between bacteria associated with oysters from Long Island Sound and the Chesapeake Bay systems.

Characterization of Reactive and Sensitive Skin Microbiota: Effect of Halymenia durvillei (HD) Extract Treatment

After characterization of the reactive skin microbiota, we investigated whether the active Halymenia durvillei (HD), rich in polysaccharides, could modulate this microbiota after 28 days of treatment, act on neuroinflammation parameters, and calm feelings of discomfort and redness. Skin microbiota was assessed using next-generation sequencing experiments (16S RNA gene fragment sequencing) on samples collected from 30 volunteers suffering from reactive, sensitive skin. To evaluate the effect of the HD extract on neuroinflammation, we used an ex vivo model. Finally, an in vivo study was performed using a clinical assessment (blood microcirculation via videocapillaroscopy) of functional signs employing the Sensitive Scale and the soothing effect was evaluated and compared to a placebo treatment. At the phylum level, the samples were mostly composed of Actinobacteria, Proteobacteria, Firmicutes, and Bacteroidetes, which accounted for more than 97% of the total sequencing read in all samples, with no differences before or after treatment with the HD active ingredient. The Shannon Diversity index indicated lower microbial communities compared to healthy skin. Maintenance of the Shannon Diversity index was reported after 28 days of HD active ingredient treatment, wherein microbial communities continued to decrease in number during treatment with the placebo. The average taxonomic composition of associated skin microbial communities showed that reactive skin is characterized by a low proportion of the Chryseobacterium genus compared to a high proportion of the Corynebacterium genus. At the species level, Actinobacteria are mainly represented by Propionibacterium acnes (72.13%) and Corynebacterium kroppenstedtii (13.23%), representing species typically observed in clinical cases of redness, the main criteria for volunteer inclusion. Corynebacterium kroppenstedtii, with increased levels being associated with skin redness, decreased with HD treatment. This decrease coincided with the clinical improvement observed after 7 weeks of treatment. The ex vivo study revealed that the HD extract induced a significant decrease in the expression of TRPV-1 (−67%; p &lt; 0.001) and NK1-R (−43%; p &lt; 0.01) compared to the control after 6 days of treatment. These data support the use of polysaccharides, found in red alga, in the treatment of reactive and sensitive skin related to the modulation of skin microbiota.

PSVI-35 The combined effects of early-socialization of piglets and neonatal enriched environment on intestinal gene expression and fecal community structure

Abstract The management of the litters through practices of early-socialization and environmental enrichment has been shown to improve piglet’s adaptation at weaning, reducing stress response. We hypothesized that changes in the neonatal environment of piglets could also modulate the maturation of intestinal microbiota and gene expression at weaning. In a commercial farm, 14 maternity sows and their litters were allotted to two treatments: a control treatment (commercial conditions, CTR) and an enriched treatment (ENR) in which piglets from two litters were mixed 14 days post-partum by removing fences. Moreover, the farrowing pen was fitted with hanging objects. Piglets were mixed after weaning (d28) according to their body size, as in commercial practice, but keeping experimental groups. Faecal and jejunum samples were collected from 7 piglets/treatment before (d26) and after (d31) weaning. Faecal microbiome was analyzed by sequencing the 16S RNA gene (Illumina MiSeq®) and OpenArray® technology was used for gene expression analysis. No significant changes promoted by treatments were found in microbiota structure during lactation. However, dissimilarities were observed after weaning (Penvfit = 0.04) although we were not able to detect significant changes in particular taxa. Weaning had an evident impact in the microbiota structure with increases in α-diversity and a clear decrease in Lactobacillaceae family. Regarding intestinal gene expression, a higher expression of the TLR2 gene was registered in CTR piglets after weaning (P = 0.03). The weaning process itself was associated with changes in the expression of numerous genes related to barrier function, digestive enzymes and nutrient transport. Results confirm that early socialization of piglets and an enriched neonatal environment during lactation, can have an impact on the maturation of the intestinal microbiota after weaning. These effects could be mediated by a differential stress response and changes in the cross-talk between the host and the intestinal microbiota.

PSVI-34 Evaluating the impact of two Bacillus probiotic strains in commercial sows and their litters

Abstract The effect of long-term administration of two different Bacillus strains was tested on 90 breeding sows (Landrace x Yorkshire) that were randomly allotted into three treatments: a control group (CON), supplemented with 5x108 cfu/kg B. subtilis 25841 (PR1), or 5x108 cfu/kg B. amyloliquefaciens 25840 (PR2). Reproductive parameters were registered along three reproductive full cycles. Fecal samples were taken along the third cycle from the sows (on days 8 and 21 of lactation) and from the piglets (on days 21 and 33 (12 post-weaning)). Fecal microbiota was analyzed by sequencing the 16S RNA gene (Illumina MiSeq®) and jejunum samples, obtained from piglets on day 21, analyzed for gene expression (52 genes by OpenArray® plate). Supplemented sows showed higher number of born piglets per litter (P = 0.01) and PR2 sows a higher number of born alive (P = 0.01). Regarding sows’ fecal microbiota, changes were found in community structure (ANOSIM test, P = 0.08) with changes at phylum level (Firmicutes:Bacteroidetes: 3.7, 5.3 and 4.6 for CON, PR1 &amp; PR2, P = 0.10) and at family level (Prevotellaceae: 9.4, 7.3, 7.3% (P = 0.03) and Ruminococcaceae: 16.1, 13.1, 13.7% (P = 0.04)). Several genera were also modified including Prevotella, Ruminococcus and Megasphaera. Regarding the microbiota of piglets, the administration of probiotics to their mothers was associated to structural changes in piglets’ fecal community during lactation (PEnvfit=0.05) but not after weaning, although relevant changes were observed between both periods (PEnvfit&amp;lt; 0.001). The expression of different genes was clearly modified by weaning but we were not able to detect changes related to the probiotic in any of the genes analyzed. In conclusion, the addition of B. subtilis 25841 and B. amyloliquefaciens 25840 were shown to enhance the sow reproductive performance in terms of prolificacy, with a clear impact on the gut microbial ecosystem of the sows and shifts in the microbiota structure of suckling piglets.

Paenibacillus xylanivorans sp. nov., a xylan-degrading bacterium isolated from decaying forest soil.

A xylanolytic bacterial strain, named A59T, was isolated from a forest soil consortium in southern Argentina. Strain A59T is a Gram-stain-positive, facultative anaerobic, endospore-forming and rod-shaped bacterium. Its optimal growth conditions are 30 °C (range, 28-37 °C), pH 7 (range, pH 5-10) and it tolerates up to 7 % of NaCl (range, 2-7 %). Chemotaxonomic analysis revealed that strain A59Tpossesses meso-diaminopimelic acid in the cell wall. It contains menaquinone MK-7 as the predominant isoprenoid quinone and the major fatty acid is anteiso-C15 : 0 (35.1 %), with a moderate amount of C16 : 0 (6.9 %). According to 16S RNA gene sequence analysis, the isolate is phylogenetically placed in the same cluster as Paenibacillus taichungensis BCRC 17757T (99.7 % nucleotide sequence identity) and Paenibacillus pabuli NBRC 13638T (99.1 %) and is closely related to Paenibacillus tundrae A10bT (98.8 %). However, phylogenetic studies based on the housekeeping gyrB gene placed A59T in a separate branch from all other related type strains. Furthermore, the results of whole genome average nucleotide identity analysis (gANI) with related type strains was lower than 91.10 % and the digital DNA-DNA hybridization value was lower than 44.30 %, which are below the threshold values for separating two species. The DNA G+C content was estimated as 46.09 mol%, based on genome sequencing. On the basis of these results, A59T represents a new species of the genus Paenibacillus, and we propose the name Paenibacillusxylanivorans sp. nov. The type strain is A59T (=DSM 107920T=NCIMB 15123T).

Temporal development of the oral microbiome and prediction of early childhood caries

Human microbiomes are predicted to assemble in a reproducible and ordered manner yet there is limited knowledge on the development of the complex bacterial communities that constitute the oral microbiome. The oral microbiome plays major roles in many oral diseases including early childhood caries (ECC), which afflicts up to 70% of children in some countries. Saliva contains oral bacteria that are indicative of the whole oral microbiome and may have the ability to reflect the dysbiosis in supragingival plaque communities that initiates the clinical manifestations of ECC. The aim of this study was to determine the assembly of the oral microbiome during the first four years of life and compare it with the clinical development of ECC. The oral microbiomes of 134 children enrolled in a birth cohort study were determined at six ages between two months and four years-of-age and their mother’s oral microbiome was determined at a single time point. We identified and quantified 356 operational taxonomic units (OTUs) of bacteria in saliva by sequencing the V4 region of the bacterial 16S RNA genes. Bacterial alpha diversity increased from a mean of 31 OTUs in the saliva of infants at 1.9 months-of-age to 84 OTUs at 39 months-of-age. The oral microbiome showed a distinct shift in composition as the children matured. The microbiome data were compared with the clinical development of ECC in the cohort at 39, 48, and 60 months-of-age as determined by ICDAS-II assessment. Streptococcus mutans was the most discriminatory oral bacterial species between health and current disease, with an increased abundance in disease. Overall our study demonstrates an ordered temporal development of the oral microbiome, describes a limited core oral microbiome and indicates that saliva testing of infants may help predict ECC risk.