Changes In Bacterial Populations Research Articles

Fecal microbiota characteristics of Chinese patients with primary IgA nephropathy: a cross-sectional study

BackgroundGrowing evidence has shown that the gut-renal connection and gut microbiota dysbiosis play a critical role in immunoglobulin A nephropathy (IgAN). However, the fecal microbiome profile in Chinese patients with IgAN remains unknown. A cross-sectional study was designed for the first time to investigate the fecal microbiota compositions in patients with primary IgAN in China and to evaluate the relationship between the fecal microbiome and IgAN clinical presentation.MethodsFecal samples were collected from 17 IgAN patients and 18 age-, sex-, and body mass index-matched healthy controls, and bacterial DNA was extracted for 16S ribosomal RNA gene sequencing targeting the V3-V4 region.ResultsFecal samples from the IgAN patients and healthy controls showed differences in gut microbiota community richness and compositions. Compared to the healthy controls, IgAN patients at the phylum level had an increased abundance of Fusobacteria, but a decreased abundance of Synergistetes. The significantly increased genera in the IgAN group were Escherichia-Shigella, Hungatella, and Eggerthella, all of which possess pathogenic potential. Furthermore, the genus Escherichia-Shigella was negatively associated with the estimated glomerular filtration rate (eGFR) but was positively associated with the urinary albumin-to-creatinine ratio (uACR). However, the genus rectale_group was present in the IgAN group with a low abundance and was negatively associated with the uACR. Functional analysis disclosed that infection-related pathways were enriched in the IgAN group.ConclusionsWe demonstrate that gut microbiota dysbiosis occurs in patients with IgAN, and that changes in gut bacterial populations are closely related to IgAN clinical features, suggesting that certain specific gut microbiota may be a potential therapeutic target for IgAN.

Changes in Bacterial Populations and Their Metabolism over 90 Sequential Cultures on Wheat-Based Thin Stillage.

Wheat-based thin stillage (W-TS) is a liquid co-product of wheat fermentation for ethanol production, which typically contains substantial amounts of glycerol. Two-stage fermentation, via endemic microorganisms, can be used in processes to convert this compound to more valuable products and simplify the enrichment process through the clarification of the medium and concentration of particles as a protein-rich concentrate. We recultured bacteria 90 times (72 h at 37 °C) on fresh W-TS to determine the stability of the culture and metabolic processes. Next-generation sequencing of W-TS revealed the presence of a predominant Lactobacillus community that rapidly displaced competing microorganisms (e.g., Pediococcus) in subsequent fermentations. These organisms produced bacteriocins (e.g., helveticin J, interpreted through the presence of bacteriocin genes) and acidified the fermentation broth (through the production of succinic acid: 1.7 g/L, lactic acid: 1.8 g/L, and acetic acid: 4.1 g/L). Furthermore, the microbial community produced cobalamin (inferred through sequencing) and converted glycerol (10 g/L reduced to 3.5 g/L after 72 h) to 1,3-propanediol (6.1 g/L after 72 h). Altogether, Lactobacilli were identified as the predominant endemic microorganisms in W-TS after the first 10 cultures. The community was stable and provided a novel approach to increase the value of organic solutes in W-TS.

Hermetia illucens larvae as a Fishmeal replacement alters intestinal specific bacterial populations and immune homeostasis in weanling piglets

Hermetia illucens larvae meal (HILM) are rich in proteins and chitin, and represent an innovative feed ingredient for animals. However, little is known about the intestinal bacteria and immune homeostasis response of HILM as a fishmeal replacement on weanling piglets. Thus, this study aimed to investigate the changes in specific ileal and cecal bacterial populations and their metabolic profiles, and ileal immune indexes in weanling piglets fed with a diet containing HILM. A total of 128 weanling piglets were fed either a basal diet or 1 of 3 diets with 1%, 2%, and 4% HILM (HI0, HI1, HI2, and HI4, respectively). Each group consisted of 8 pens (replicates), with 4 pigs per pen. After 28 d of feeding, 8 barrows per treatment were euthanized, the ileal and cecal digesta, and ileal mucosa were collected for analyzing bacterial population and metabolic profiles, and immune indexes, respectively. Results showed that HILM increased (P < 0.05, maximum in HI2) the number of Lactobacillus and Bifidobacterium in the ileum and cecum, but quadratically decreased (P < 0.05, minimum in HI2) the number of Escherichia coli. In the cecum, the number of Firmicutes, Ruminococcus, Clostridium cluster IV, and Prevotella showed a quadratic response to increasing (P < 0.05, maximum in HI2) HILM levels. Lactate and butyrate concentrations in the ileum and cecum were quadratically increased (P < 0.05, maximum in HI2) with increasing HILM levels. In the cecum, the amines, phenol, and indole compounds concentrations were quadratically decreased (P < 0.05, minimum in HI2) with increasing HILM levels, while total short-chain fatty acids and acetate concentrations were quadratically increased (P < 0.05, maximum in HI2). In the ileum, the TLR4, NF-κB, MyD88, and TNF-α mRNA expressions were quadratically decreased (P < 0.05, minimum in HI2) with increasing HILM levels, while the mRNA expression of IL-10, barrier function (MUC1, ZO-1, Occludin, and Claudin-2), and development-related genes (IGF-1, GLP-2, and EGF) was quadratically increased (P < 0.05, maximum in HI2). Furthermore, the changes in the mucosal gene expression were associated with changes in the bacterial populations and their metabolites. Collectively, these results showed that a diet supplemented with 2% HILM affected specific bacterial populations and metabolic profiles, and maintained ileal immune status. These findings provide new insights into the use of insect meal as a suitable alternative protein source for swine feeding.

Related Enteric Viruses Have Different Requirements for Host Microbiota in Mice.

Accumulating evidence suggests that intestinal bacteria promote enteric virus infection in mice. For example, previous work demonstrated that antibiotic treatment of mice prior to oral infection with poliovirus reduced viral replication and pathogenesis. Here, we examined the effect of antibiotic treatment on infection with coxsackievirus B3 (CVB3), a picornavirus closely related to poliovirus. We treated mice with a mixture of five antibiotics to deplete host microbiota and examined CVB3 replication and pathogenesis following oral inoculation. We found that, as seen with poliovirus, CVB3 shedding and pathogenesis were reduced in antibiotic-treated mice. While treatment with just two antibiotics, vancomycin and ampicillin, was sufficient to reduce CVB3 replication and pathogenesis, this treatment had no effect on poliovirus. The quantity and composition of bacterial communities were altered by treatment with the five-antibiotic cocktail and by treatment with vancomycin and ampicillin. To determine whether more-subtle changes in bacterial populations impact viral replication, we examined viral infection in mice treated with milder antibiotic regimens. Mice treated with one-tenth the standard concentration of the normal antibiotic cocktail supported replication of poliovirus but not CVB3. Importantly, a single dose of one antibiotic, streptomycin, was sufficient to reduce CVB3 shedding and pathogenesis while having no effect on poliovirus shedding and pathogenesis. Overall, replication and pathogenesis of CVB3 are more sensitive to antibiotic treatment than poliovirus, indicating that closely related viruses may differ with respect to their reliance on microbiota.IMPORTANCE Recent data indicate that intestinal bacteria promote intestinal infection of several enteric viruses. Here, we show that coxsackievirus, an enteric virus in the picornavirus family, also relies on microbiota for intestinal replication and pathogenesis. Relatively minor depletion of the microbiota was sufficient to decrease coxsackievirus infection, while poliovirus infection was unaffected. Surprisingly, a single dose of one antibiotic was sufficient to reduce coxsackievirus infection. Therefore, these data indicate that closely related viruses may differ with respect to their reliance on microbiota.

Metagenomic analysis of microbial community associated with coral mucus from the Gulf of Aqaba

Coral-associated microbial communities contribute to a wide variety of useful roles regarding the their host, and therefore, the arrangement of the general microbiome network can emphatically impact coral wellbeing and survival. Various pollution sources can interfere and disrupt the microbial relationship with corals. Here, we adopted the bacterial tag-encoded FLX amplicon pyrosequencing (bTEFAP®) technique to investigate the shift of microbial communities associated with the mucus of the coral Stylophora pistillata collected from five sites (Marine Science Station, Industrial Complex, Oil Terminal, Public Beach, and Phosphate Port) along the Gulf of Aqaba (Red Sea). Our results revealed a high diversity in bacterial populations associated with coral mucus. Proteobacteria were observed to be the dominating phylum among all sampling sites. The identified bacterial taxa belong to the pathogenic bacteria from the genus Vibrio was presented in varying abundances at all sampling sites. Diversity and similarity analysis of microbial communists based on rarefaction curve and UniFrac cluster respectively demonstrated that there are variances in microbial groups associated with coral mucus along sites. The pollution sources among different locations along the Gulf of Aqaba seem to affect the coral-associated holobiont leading to changes in bacterial populations due to increasing human activities.

Temporal Dynamics in Rumen Bacterial Community Composition of Finishing Steers during an Adaptation Period of Three Months.

The objective of this study was to explore whether collecting rumen samples of finishing steers at monthly intervals differed, and whether this difference or similarity varied with diets. For these purposes, 12 Chinese Holstein steers were equally divided into two groups. The dietary treatments were either standard energy and standard protein (C) or low energy and low protein (L). Rumen samples were obtained on day 30, day 60 and day 90 from both dietary treatments and were analyzed by using 16S rRNA gene sequencing. The results showed that monthly intervals had no effect on the richness and evenness of the rumen bacterial community in the two diets. However, taxonomic difference analysis (relative abundance >0.5%) revealed that the relative abundance of three phyla (Proteobacteria, Fibrobacteres and Cyanobacteria) and six genera (Rikenellaceae_RC9_gut_group, Ruminococcaceae_NK4A214_group, Fibrobacter, Eubacterium_coprostanoligenes_group, Ruminococcaceae_UCG-010 and Ruminobacter) were significantly different between monthly sampling intervals, and the difference was prominent between sampling in the first month and the subsequent two months. Moreover, the differences in abundances of phyla and genera between monthly sampling intervals were affected by diets. Analysis of similarity (ANOSIM) showed no significant differences between monthly sampling intervals in the C diet. However, ANOSIM results revealed that significant differences between the first month and second month and between the first month and third month were present in the L diet. These results indicated that temporal dynamics in rumen bacterial community composition did occur even after an adaptation period of three months. This study tracked the changes in rumen bacterial populations of finishing cattle after a shift in diet with the passage of time. This study may provide insight into bacterial adaptation time to dietary transition in finishing steers.

Abstract 220: Gut Microbiota Alterations Associate With T Cell Activation and Adverse Cardiac Remodeling in Response to Cardiac Pressure Overload

Background: The complex syndrome of heart failure (HF), a leading cause of morbidity and mortality affecting more than 24 million people worldwide, is recently becoming associated with alterations in gut microbiota, also known as gut dysbiosis, as well as with T cell mediated systemic inflammation and T cell infiltration in the heart. Specifically, certain bacteria promote T cell activation, and T cell activation contributes to adverse cardiac remodeling and cardiac dysfunction in HF. We hypothesize that gut dysbiosis modulates cardiac remodeling and function in a T cell-dependent manner. Results: C57/BL6 mice were orally treated with a well-stablished wide spectrum antibiotic cocktail (ABX) and subjected to transverse aortic constriction (TAC), a model of non-ischemic HF. ABX was present during the duration of TAC (4 weeks), thus sterilizing the gut completely, or during 3 weeks before TAC followed by removal during the 4 weeks of TAC duration for spontaneous recovery of the gut microbiota (TAC-REC). The lack of gut microbiota showed a reduced T cell activation in the mediastinal lymph nodes and heart T cell infiltration, as well as cardiac fibrosis and cardiac hypertrophy were prevented in response to TAC. Nevertheless, gut dysbiosis induced by bacterial recolonization only partially recovered this phenotype. In addition, we sequenced 16S RNA to study the changes in bacterial populations in Sham, TAC, and TAC-REC. TAC induced changes in the gut microbiota compared to Sham surgery, which resulted in a higher relative abundance of several genera, such as Bacteroides, and lower relative abundance of Coprococcus, Lactobacillus and Bifidobacterium, these last two normally associated to an anti-inflammatory response. At the end of the experiment, bacterial recolonization in TAC-REC mice showed different relative bacterial abundance between TAC and TAC-REC, although there were no significant changes in diversity at 4 weeks post-TAC. Conclusion: Collectively, our findings suggest that changes in gut microbiota constitution modify T cell activation and migration to the heart in the TAC model. Exploring the role of gut microbiota in modulating adverse cardiac remodeling and cardiac function can become an optimal therapeutic target to treat HF patients.

Changes in Microbial Population Numbers during Composting of Some Organic Wastes in Greenhouse

Aim: This study identified and enumerated microorganisms associated with the composting of some organic wastes using the plate count method&#x0D; Study Design: The wastes were allowed to decompose for 70 days in greenhouse using the modified windrow method of composting. Standard methods were employed to monitor temperature changes in compost piles as well as changes in bacterial and fungal populations.&#x0D; Place and Duration of Study: This study was carried out at in the Agricultural Research Centre of the Federal University of Technology, Owerri, Nigeria.&#x0D; Methodology: The organic wastes namely Poultry Litter (PL), Pig waste (PW), Cow dung (CD) and Source-Separated Municipal Solid Waste (MSW) were composted/co-composted using the windrow method as modified .Sixty kilograms (60) each of PW, PL, CD and MSW were introduced respectively into 100-litre(L) buckets that had previously been perforated at several points. In the co-composted piles, 30 kg of both samples were introduced into the same 100 L bucket that had previously been perforated and then mixed thoroughly. The organic wastes were allowed to decompose at room temperature at a corner of the greenhouse. and initial microbial populations as well as subsequent populations in the compost bins were studied using standard microbiological methods&#x0D; Results: Microbial populations increased concurrently with temperature during the first 3 – 4 weeks of composting except, however, for faecal coliforms and Salmonella. The highest temperature recorded was 60°C for cow dung (CD) compost pile though at maturity the temperature in all compost piles ranged between 27°C to 30°C. The bacterial colony forming units were higher than fungal colony forming units throughout the composting period for both mesopholic and themophilic microorganisms. The population of mesophilic organisms increased in the first 14 – 15 days; for cow dung, the initial total heterotrophic bacteria count (THBC) and total coliform count (TCC) were 2.4 x107 cfu/g and 5.0 x105 cfu/g respectively and increased to 2.5x108 cfu/g and 1.7x107 cfu/g for THBC and TCC, respectively, after the 14th day. Thermophilic bacteria dominated all the composting systems after the 21st day and lasted to the 35th day except for cow dung compost where thermophilic temperatures were still observed on the 45th day with a THBC of 6.3x106 cfu/g on the 49th day. Faecal coliforms and Salmonella were completely eliminated in all the compost systems after the 28th day with temperature values between 47°C – 60°C.&#x0D; Conclusion: Organic wastes when managed properly through the application of knowledge of composting can be transformed into beneficial materials for human and agricultural use.

Temporal Stability of the Ruminal Bacterial Communities in Beef Steers

Nutritional studies involving ruminants have traditionally relied on relatively short transition or wash-out periods between dietary treatments, typically two to four weeks. However, little is known about adequate adaptation periods required to reach stabilization of the rumen microbiome that could provide more accurate results from nutritional studies in ruminants. This study determined the rumen bacterial communities and rumen environment parameters over ten weeks following transition from a forage-based to concentrate-based diet. Several α-diversity metrics, including observed OTUs and Simpson’s Evenness fluctuated throughout the trial, but were typically either greatest (observed OTUs) or lowest (Simpson’s) at week 5 of the trial contrasted from weeks 1 and 10 (P < 0.05). At week 4, several orders associated with the shift to the final bacterial community composition, including Pasteurellales, Aeromonadales, and Bacteroidales. At week 5, rumen pH was correlated with α-diversity (P = 0.005) and predictive of the rumen microbiome signature at week 10 (R2 = 0.48; P = 0.04). Rumen microbiome stability did not occur until approximately 9 weeks following adaptation to the diet and was associated with changes in specific bacterial populations and rumen environment. The results of this study suggest that adaptation and wash-out periods must be re-evaluated in order to accommodate necessary rumen microbiome acclimation.

Effect of dietary concentrate to forage ratios on ruminal bacterial and anaerobic fungal populations of cashmere goats

The rumen contains a highly complex microbial ecosystem that plays an important role in converting solar energy in plants into nutrients for ruminants and generates animal food products, such as meat and milk for humans. Therefore, understanding the effect of the dietary concentrate to forage (C:F) ratio on ruminal microbiota is of great significance for the growth and development of ruminants. In this study, changes in the ruminal bacterial and anaerobic fungal populations of Shaanbei white-cashmere (SWC) goats that were reared under different dietary C:F ratios were evaluated by high-throughput sequencing analysis. It was found that dietary C:F ratio has a significant impact on the composition of the ruminal bacteria in SWC goats. The levels of Actinobacteria and Proteobacteria were significantly increased (P < 0.05), whereas the level of Bacteroidetes was significantly decreased when the proportion of dietary concentrate was increased (P < 0.05); as the proportion of dietary concentrate increased, Prevotella, Selenomonas, and Treponema were significantly increased (P < 0.05), whereas Oscillospira and Succiniclasticum were significantly reduced (P < 0.05). Furthermore, different dietary C:F ratios significantly affected the composition of anaerobic fungi in SWC goats. As the proportion of dietary concentrate increased, Ascomycota, Basidiomycota, and Zygomycota were significantly increased (P < 0.05), while Neocallimastigomycota was significantly reduced (P < 0.05); the levels of Alternaria, Aspergillus, Neocallimastix, Orpinomyces, Piromyces, and Stachybotrys were significantly increased, while those of Candida, Penicillium, and Trichosporon were significantly decreased when the proportion of dietary concentrate increased (P < 0.05). These findings will help us to better understand the changes in ruminal bacterial and anaerobic fungal populations of SWC goats under different dietary C:F ratios, which could provide a theoretical basis for microecological regulation of SWC goats.

Fate of Mycobacterium avium subsp. paratuberculosis and changes in bacterial diversity populations in dairy slurry after chemical treatments.

A major drawback of using dairy slurry as fertilizer is that it may contains pathogens such as Mycobacterium avium subsp. paratuberculosis (MAP), and it could represent a risk to animal and public health. Thus, the aim of this study was to evaluate the fate of MAP and bacterial communities in dairy slurry after chemical treatments. Cattle slurry, naturally contaminated with MAP, was collected from a dairy herd and divided into 32 glass bottles which were assigned to eight different treatments (control, 3·0% CaO, 0·5% NaOH; 0·087%, 0·11% and 0·14% H2 SO4 ; and 1·0 and 2·5% KMnO4 ). Treated dairy slurry samples were evaluated at 0, 1, 3, 7, 15, 30 and 60-days following treatment application for viable MAP and dairy slurry pH, and in addition temperature in this material was monitored continuously. Bacterial counts were estimated at each sampling time. A Bayesian zero-inflated Poisson mixed model was fitted to assess the effect of each treatment on the count of MAP cells. Model results indicated that only the 3·0% CaO treatment had a statistically important negative effect on MAP counts during the study period. For most treatments, MAP was undetectable immediately after chemical treatment but re-appeared over time, in some replicates at low concentrations. However, in those cases MAP counts were not statistically different than the control treatment. Regarding the fate of the other bacterial populations, the Firmicutes phylum was the dominant population in the un-treated slurry while Clostridia class members were among the most prevalent bacteria after the application of most chemical treatments. Only 3% CaO treatment had a statistically important negative effect on MAP viability in cattle slurry. This study provides evidence of MAP partial control in dairy slurry. This information should be considered as a best management practice to reduce MAP and other pathogens for slurry management on dairy farms.

Dietary supplementation with inulin-propionate ester or inulin improves insulin sensitivity in adults with overweight and obesity with distinct effects on the gut microbiota, plasma metabolome and systemic inflammatory responses: a randomised cross-over trial

ObjectiveTo investigate the underlying mechanisms behind changes in glucose homeostasis with delivery of propionate to the human colon by comprehensive and coordinated analysis of gut bacterial composition, plasma metabolome and...

Colloidal carbon interference in the treatability of pulp and paper wastewater by MBR

Pulp and paper wastewaters are challenging to treat due to their variability, complexity and toxicity. Membrane Bioreactor’s (MBR’s) provide high-quality filtrates but are subject to periods of low filterability / high capillary suction time (CST) which potentially limit their use in this application. There is a paucity of published literature concerning long-term operational issues in full-scale, industrial MBR’s. We hypothesised that either changes of bacterial population, alteration/reduction of bacterial metabolism or bacterial production of extra-cellular polymers (ESPs) increased CST and reduced filterability. This study, conducted over two years at the 16.4MLD Gippsland Water Factory, was structured to inform this bacterial centric hypothesis. However, no shifts in bacterial population were seen as causative of high CST and microbial stress levels and biological activity were observed to be low during high CST and no sign of toxicity was found. The strongest correlator with CST was the concentration of colloidal Total Organic Carbon of the mixed liquor suspended solids (MLSS) supernatant (following centrifugation). The carbonaceous colloids accumulated in the supernatant were named ‘Non-Centrifugable Total Organic Carbon’ (NCTOC). Their accumulation in the MLSS was found be due to their biologically refractory nature and their retention by the MBR membrane. The accumulation of NCTOC typically followed a period where the influent had a high colour and a high sodium to calcium ratio, which is consistent with a pulping by-product called ‘Black Liquor’. Additional experiments with Black Liquor allowed us to conclude that high CST can be produced by addition of Black Liquor.

Exploring the Link between Superimposed Preeclampsia and the Gut Microbiome

Preeclampsia, a hypertensive disorder of pregnancy, is a leading cause of maternal and fetal morbidity and mortality worldwide. Despite the rising prevalence and severity of this disease, the initiating factors responsible for the development of preeclampsia remain unknown. Recent evidence suggests an association of gut microbiome changes with certain forms of hypertension, but the effects of differences in the microbiome during preeclampsia are unknown. We hypothesized that gut dysbiosis contributes to the development of the preeclamptic phenotype in the Dahl salt‐sensitive rat (Dahl S) model of preeclampsia superimposed on hypertension and chronic kidney disease. Sprague Dawley (SD) rats were used for comparison as a model of healthy pregnancy, and comparisons were made to age matched virgin littermates in both strains. All rats were housed in the same room and maintained on a 0.3% NaCl diet (TD7034) for 5 months prior to study. Fecal samples were obtained on two separate days for baseline measures, and then half of the rats in each strain were mated (n=7–9/group). Samples were collected on days 6, 13, and 20 of pregnancy and then one week postpartum (Day ~29). Microbial DNA was isolated from fecal matter, and the V3‐V4 region of 16S ribosomal RNA was PCR amplified and processed through the Illumina 16S sequencing pipeline. A single library was generated (n=191) and run on Illumina MiSeq instrument. The sequencing reads were processed via QIIME application (Illumina Cloud BaseSpace) which provided an initial analysis of sequencing reads by quality filtering, operational taxonomic unit (OTU) picking, and taxonomic assignment. The web‐based Microbiome Analyst was used for statistical analysis to establish differences in microbiota diversity, composition, and tools for visualization. A preliminary analysis of the fecal microbiota between SD and Dahl S showed a distinct diversity (alpha and beta) in the microbiome between Dahl S and SD rats at baseline. The microbiome diversity stayed relatively constant over the course of pregnancy for SD (versus virgin control), whereas in Dahl S there was a significant difference at day 20 compared to virgin controls. Dahl S microbiome diversity at each time point in pregnancy (day 6, 13, and 20) trended higher than SD. Both pregnant Dahl S and SD (versus virgin) demonstrated a significant change at the Phylum level for several taxa. However, the ratio of Firmicutes:Bacteroidetes (F:B) ratio remained relatively constant across pregnancy for both Dahl S (average ratio 1.34) and SD (1.37), with the exception of day 20 in pregnant Dahl S which demonstrated a significant change in F:B ratio from 1.30 (virgin) to 0.78 (pregnant). Currently, we are working to perform a more systematic analysis, including potential changes in bacterial populations that produce beneficial short‐chain fatty acids (SCFA) that have been identified in other models of hypertension to place the differences in context of physiological changes. Future studies will determine if manipulation of the microbiota in the Dahl S strain will improve the preeclamptic phenotype and offspring outcomes.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Signal Disruption Leads to Changes in Bacterial Community Population.

The disruption of bacterial signaling (quorum quenching) has been proven to be an innovative approach to influence the behavior of bacteria. In particular, lactonase enzymes that are capable of hydrolyzing the N-acyl homoserine lactone (AHL) molecules used by numerous bacteria, were reported to inhibit biofilm formation, including those of freshwater microbial communities. However, insights and tools are currently lacking to characterize, understand and explain the effects of signal disruption on complex microbial communities. Here, we produced silica capsules containing an engineered lactonase that exhibits quorum quenching activity. Capsules were used to design a filtration cartridge to selectively degrade AHLs from a recirculating bioreactor. The growth of a complex microbial community in the bioreactor, in the presence or absence of lactonase, was monitored over a 3-week period. Dynamic population analysis revealed that signal disruption using a quorum quenching lactonase can effectively reduce biofilm formation in the recirculating bioreactor system and that biofilm inhibition is concomitant to drastic changes in the composition, diversity and abundance of soil bacterial communities within these biofilms. Effects of the quorum quenching lactonase on the suspension community also affected the microbial composition, suggesting that effects of signal disruption are not limited to biofilm populations. This unexpected finding is evidence for the importance of signaling in the competition between bacteria within communities. This study provides foundational tools and data for the investigation of the importance of AHL-based signaling in the context of complex microbial communities.

Assessment of chromium induced alterations on gut bacterial population of E. eugeniae

The aim of the present study was to enumerate the diversity of gut bacterial population of epigeic earthworm species, E. eugeniae exposed to heavy metal. Adult earthworms were treated with three different doses (0.06%, 0.13% and 0.19% w/v) of potassium dichromate (K2Cr2O7) for this purpose. The gut samples were serially diluted and inoculated in seven distinct media viz. Jensen's media, King’smedium B base, Burk’s media, Yeast Mannitol Agar media, Vogel- Johnson agar base media, Luria Bertani Broth Miller and Nutrient agar media. Dose dependent decrease in bacterial population was observed in treated worms when compared with control. Maximum percent change (62.59%) in bacterial population was observed in Burk’s media when exposed to 0.19% chromium. The results revealed that chromium alters the microbial population present in gut of earthworms. Therefore, changes in earthworms’ gut microbial community due to soil management practices can also be used as markers of soil fertility and quality.

Effect of Temperature Changes on the Bacterial and Fungal Succession Patterns during Composting of Some Organic Wastes in Greenhouse

Aim: Organic wastes were composted and the effect of temperature changes on the bacterial and fungal succession patterns studied.&#x0D; Study Design: The wastes which included cow dung (CD), pig waste (PW), poultry litter (PL) and source-separated municipal solid waste (MSW) and their combinations: PL+MSW, PW+MSW and CD+MSW were allowed to decompose for 70 days in a greenhouse.&#x0D; Place and Duration of Study: This study was carried out between September 2017 and January 2018, in the greenhouse of the Agricultural Research Farm of Federal University of Technology, Owerri, Nigeria.&#x0D; Methodology: The wastes were allowed to decompose for 70 days in a greenhouse using the modified windrow method of composting. Standard microbiological methods were used to monitor temperature changes in compost piles as well as changes in bacterial and fungal populations.&#x0D; Results: Results revealed that changes in temperature affected microbial composition in the compost piles. The highest temperature recorded was 60oC for cow dung (CD) compost pile while at maturity the temperature in all the compost piles ranged between 27°C to 30°C. Different bacterial and fungal populations were isolated during the thermophilic and mesophilc phases of composting. Bacteria isolates included species of Staphylococcus, Proteus, Klebsiella, Salmonella, Alcaligenes, Serratia, Lactobacillus and Pseudomonas. Others included Enterobacter, Bacillus, Streptococcus, Corynebacterium and Micrococcus spp. Fungal species isolated included Candida, Saccharomyces, Rhizopus, Aspergillus, Mucor and Fusarium.&#x0D; Conclusion: The presence of some plant growth promoting (PGP) bacteria at the end of composting qualifies organic waste composts as effective nutrient sources for crop production and can be considered as potential alternatives to chemical fertilizers.

Association of Systemic Antibiotic Treatment of Acne With Skin Microbiota Characteristics

Given the widespread use of systemic antibiotics for treatment of moderate to severe acne, it is important to understand the associations of such antibiotic use with changes not only in Cutibacterium acnes (formerly Propionibacterium acnes) but also in the complete bacterial community of the skin. To examine the composition, diversity, and resilience of skin microbiota associated with systemic antibiotic perturbation in individuals with acne. This longitudinal cohort study conducted at an academic referral center in Maryland from February 11 to September 23, 2014, included 4 female participants who had received a recent diagnosis of acne vulgaris, showed comedonal and inflammatory acne on the face, were at least 18 years old, and had no recent use of systemic or topical treatments for acne, including antibiotics and retinoids. Data analysis was performed between July 5, 2017, and November 7, 2018. Participants were prescribed oral minocycline, 100 mg, twice daily for 4 weeks. Skin areas on the forehead, cheek, and chin were sampled for 16S ribosomal RNA gene sequencing at baseline, 4 weeks after starting minocycline treatment, and then 1 week and 8 weeks after discontinuation of treatment. Skin microbiota examined with respect to relative abundance of bacterial taxa, α diversity (represents within-sample microbial diversity), and β diversity (represents between-sample microbial diversity). Acne status evaluated with photography and lesion count. Of the 4 patients included in this study, 2 were 25 years old, 1 was 29 years old, and 1 was 35 years old; 2 were white women, 1 was an African American woman, and 1 was an Asian woman. Across all 4 patients, antibiotic treatment was associated with a 1.4-fold reduction in the level of C acnes (difference, -10.3%; 95% CI, -19.9% to -0.7%; P = .04) with recovery following cessation of treatment. Distinct patterns of change were identified in multiple bacterial genera, including a transient 5.6-fold increase in the relative abundance of Pseudomonas species (difference, 2.2%; 95% CI, 0.9%-3.4%; P < .001) immediately following antibiotic treatment, as well as a persistent 1.7-fold increase in the relative abundance of Streptococcus species (difference, 5.4%; 95% CI, 0.3%-10.6%; P = .04) and a 4.7-fold decrease in the relative abundance of Lactobacillus species (difference, -0.8%; 95% CI, -1.4% to -0.2%; P = .02) 8 weeks following antibiotic treatment withdrawal. In general, antibiotic administration was associated with an initial decrease from baseline of bacterial diversity followed by recovery. Principal coordinates analysis results showed moderate clustering of samples by patient (analysis of similarity, R = 0.424; P = .001) and significant clustering of samples by time in one participant (analysis of similarity, R = 0.733; P = .001). In this study, systemic antibiotic treatment of acne was associated with changes in the composition and diversity of skin microbiota, with variable rates of recovery across individual patients and parallel changes in specific bacterial populations. Understanding the association between systemic antibiotic use and skin microbiota may help clinicians decrease the likelihood of skin comorbidities related to microbial dysbiosis.

Optimization on production of konjac oligo-glucomannan and their effect on the gut microbiota.

Konjac glucomannan (KGM) is a polysaccharide extracted from Amorphophallus konjac, and its degradation product is konjac oligo‐glucomannan (KOG). The aim of this study was to produce KOG from KGM and to evaluate its effect on the gut microbiota in fecal batch culture. KOG was produced by enzymatic hydrolysis using β‐mannanase. The optimum conditions were as follows: reaction temperature of 48°C, reaction time of 4 hr, pH of 5.5 and E/S of 0.05% followed by purification step using 3,000 NMWC ultrafiltration (UF) membrane pore size. The effect of KOG on changes in human fecal bacterial populations and short‐chain fatty acids (SCFAs) production was evaluated. The results showed that low‐molecular weight KOG (LKOG) from purification step with concentration of 9.54 mg/ml, and a prebiotic index (PI) of 0.76 was successfully produced. LKOG can enhance the production of butyric acid in the colon with the highest concentration (8.24 mM) found at 72 hr fermentation.

Impact of Manure Storage Time and Temperature on Microbial Composition and Stable Fly (Diptera: Muscidae) Development

Samples are often frozen for preservation until needed for use. It has been a common practice to store fresh dairy manure in the freezer until needed for fly development studies. However, conflicting data have suggested that freezer temperature and duration of manure may impact fly development studies, and it is likely due to the change in microbial comminutes due to the freezer conditions. In this study manure storage conditions were assessed to ascertain how temperatures impact stable fly, Stomoxys calcitrans L., survival to pupation and determine which bacterial populations impacted fly development using massively-parallel sequencing and 16S metagenomic analysis. Stable fly survival to pupation was greater in manure that was stored warm (27˚C) or frozen (-20˚C or -80˚C) for 24 days as compared to fresh manure samples. Refrigeration (4˚C) of the manure for 24 days did not affect fly development and slightly decreased the pupal weights. Over 80 bacterial families were detected by sequencing allowing for a more thorough assessment of changes in bacterial populations. Only minor shifts were observed in bacterial family composition in the manure when refrigerated or frozen for 24 days, but significant population changes were observed when the manure was incubated for 24 days at 27˚C. Since it is the temperature and incubation time that yielded the greatest pupation rate, it is hypothesized that the manure microbial community impacts the growth and development of stable flies. This study has determined suggested freezer conditions for the best storage of manure samples to maintain bacterial diversity and retain the closest bacterial populations to freshly collected manure. Although untouched, aged (20 days) manure is best to use to assess fly development, it is not always feasible in laboratory experimentations. This study demonstrates the importance of preservation techniques on manure samples, which could also confer to storage of other biological specimens that contain resident microbes.