scholarly journals Short-term exposure to benzalkonium chloride in bacteria from activated sludge alters the community diversity and the antibiotic resistance profile

2021 ◽  
Author(s):  
Luz Chacón ◽  
Maria Arias-Andres ◽  
Freylan Mena ◽  
Luis Rivera ◽  
Lorena Hernández ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Activated Sludge ◽  
Microbial Communities ◽  
Benzalkonium Chloride ◽  
Bacterial Community Composition ◽  
Alpha Diversity ◽  
Community Diversity ◽  
Rrna Gene ◽  
Short Term Exposure

Abstract The continuous introduction of cleaning products containing benzalkonium chloride (BAC) from household discharges can mold the microbial communities in wastewater treatment plants (WWTPs) in a way still poorly understood. In this study, we performed an in vitro exposure of activated sludge from a WWTP in Costa Rica to BAC, quantified the changes in intI1, sul2, and qacE/qacEΔ1 gene profiles, and determined alterations in the bacterial community composition. The analysis of the qPCR data revealed elevated charges of antibiotic resistance genes in the microbial community; after BAC's exposure, a significant increase in the qacE/qacEΔ1 gene, which is related to ammonium quaternary resistance, was observed. The 16S rRNA gene sequences’ analysis showed pronounced variations in the structure of the bacterial communities, including reduction of the alpha diversity values and an increase of the relative abundance of Alphaproteobacteria, particularly of Rhodospseudomonas and Rhodobacter. We confirmed that the microbial communities presented high resilience to BAC at the mg/mL concentration, probably due to constant exposure to this pollutant. They also presented antibiotic resistance-related genes with similar mechanisms to tolerate this substance. These mechanisms should be explored more thoroughly, especially in the context of high use of disinfectant.

scholarly journals Short-Term Exposure to Sterile Seawater Reduces Bacterial Community Diversity in the Sea Anemone, Exaiptasia diaphana

2021 ◽  
Vol 7 ◽  
Author(s):  
Ashley M. Dungan ◽  
Madeleine J. H. van Oppen ◽  
Linda L. Blackall
Keyword(s):  
Bacterial Community ◽  
Model Organism ◽  
Alpha Diversity ◽  
Low Complexity ◽  
Community Diversity ◽  
Rrna Gene ◽  
Adaptation To Climate Change ◽  
Short Term ◽  
Sterile Seawater ◽  
Short Term Exposure

The global decline of coral reefs heightens the need to understand how corals may persist under changing environmental conditions. Restructuring of the coral-associated bacterial community, either through natural or assisted strategies, has been suggested as a means of adaptation to climate change. A low complexity microbial system would facilitate testing the efficacy of microbial restructuring strategies. We used the model organism for corals, Exaiptasia diaphana, and determined that short-term (3 weeks) exposure to filter-sterilized seawater conditions alone reduced the complexity of the microbiome. Metabarcoding of the V5–V6 region of the bacterial 16S rRNA gene revealed that alpha diversity was approximately halved in anemones reared in filter-sterilized seawater compared to controls reared in unfiltered seawater and that the composition (beta diversity) differed significantly between the two. By reducing the complexity of the E. diaphana microbiome, the development of a system for testing assisted strategies such as probiotics, is more feasible.

scholarly journals Biogeographical distribution of microbial communities along the Rajang River–South China Sea continuum

2019 ◽  
Vol 16 (21) ◽  
pp. 4243-4260
Author(s):  
Edwin Sien Aun Sia ◽  
Zhuoyi Zhu ◽  
Jing Zhang ◽  
Wee Cheah ◽  
Shan Jiang ◽  
...  
Keyword(s):  
South China Sea ◽  
Microbial Communities ◽  
South China ◽  
Linear Models ◽  
Bacterial Community Composition ◽  
Drainage System ◽  
Alpha Diversity ◽  
Rrna Gene ◽  
China Sea ◽  
Biogeographical Distribution

Abstract. The Rajang River is the main drainage system for central Sarawak in Malaysian Borneo and passes through peat domes through which peat-rich material is being fed into the system and eventually into the southern South China Sea. Microbial communities found within peat-rich systems are important biogeochemical cyclers in terms of methane and carbon dioxide sequestration. To address the critical lack of knowledge about microbial communities in tropical (peat-draining) rivers, this study represents the first seasonal assessment targeted at establishing a foundational understanding of the microbial communities of the Rajang River–South China Sea continuum. This was carried out utilising 16S rRNA gene amplicon sequencing via Illumina MiSeq in size-fractionated samples (0.2 and 3.0 µm GF/C filter membranes) covering different biogeographical features and sources from headwaters to coastal waters. The microbial communities found along the Rajang River exhibited taxa common to rivers (i.e. predominance of β-Proteobacteria) while estuarine and marine regions exhibited taxa that were common to the aforementioned regions as well (i.e. predominance of α− and γ-Proteobacteria). This is in agreement with studies from other rivers which observed similar changes along salinity gradients. In terms of particulate versus free-living bacteria, nonmetric multi-dimensional scaling (NMDS) results showed similarly distributed microbial communities with varying separation between seasons. Distinct patterns were observed based on linear models as a result of the changes in salinity along with variation of other biogeochemical parameters. Alpha diversity indices indicated that microbial communities were higher in diversity upstream compared to the marine and estuarine regions, whereas anthropogenic perturbations led to increased richness but less diversity. Despite the observed changes in bacterial community composition and diversity that occur along the continuum of the Rajang River to the sea, the PICRUSt predictions showed minor variations. The results provide essential context for future studies such as further analyses on the ecosystem response to anthropogenic land-use practices and probable development of biomarkers to improve the monitoring of water quality in this region.

Effect of ambient water conditions on microbial communities on the artificially produced aggregates: Evidence from experiments using two different seawater cultures

2021 ◽  
Author(s):  
Markus Weinbauer ◽  
Chiaki Motegi ◽  
Christophe Migon ◽  
Xavier Mari
Keyword(s):  
Microbial Communities ◽  
Water Flow ◽  
Bacterial Community Composition ◽  
Rrna Gene ◽  
Transplant Experiment ◽  
Ambient Water ◽  
Lagoon Water ◽  
Water Conditions ◽  
Flow Experiment ◽  
Water Treatments

<p>Microbial communities on marine aggregates could be influenced by ambient water conditions; however, empirical data are scarce. In this study, we used fingerprint analysis of PCR-amplified 16S rRNA gene fragment to examine how microbial communities on aggregates change in response to different conditions of ambient water. We conducted two experiments using seawater cultures from surface waters of the lagoon and the anthropogenically influenced bay of Nouméa, New Caledonia: a transplant experiment in which the artificially produced aggregates from one station was added to ultra-filtered seawater culture of another station, and a water-flow experiment in which the artificially produced aggregates placed in the ultra-filtered seawater culture with or without water-flow. In a transplant experiment, bacterial community composition (BCC) on the bay and lagoon water aggregates were significantly different (<em>p < 0.05</em>, ANOSIM) at the beginning of experiment. After 11 days of incubation, BCC on the lagoon water aggregates were significantly different (<em>p < 0.05</em>) from transplanted communities. Transplantation effect was also observed in the bay water treatments. In a water-flow experiment, BCC on the bay and lagoon water aggregates were significantly different (<em>p < 0.05</em>) at the beginning of the experiment. BCC on the lagoon and bay water aggregates with and without water-flow treatments were significantly different (<em>p </em>< 0.05) at the end of incubation, and effect of water-flow on BCC were observed in the bay and lagoon water treatments. Our experimental studies suggest that changes in ambient water conditions potentially influence microbial communities on aggregates in the Bay of Nouméa.</p>

scholarly journals Association between the microbiomes of tonsil and saliva samples isolated from pediatric patients subjected to tonsillectomy for the treatment of tonsillar hyperplasia

2020 ◽  
Vol 52 (9) ◽  
pp. 1564-1573
Author(s):  
Da Hyeon Choi ◽  
Jiwon Park ◽  
Ju Kwang Choi ◽  
Kyeong Eun Lee ◽  
Won Hee Lee ◽  
...  
Keyword(s):  
Oral Cavity ◽  
Microbial Communities ◽  
Alpha Diversity ◽  
16S Rrna Gene Sequencing ◽  
Diversity Indices ◽  
Rrna Gene ◽  
Strong Positive Correlation ◽  
Korean Children ◽  
Positive Correlation ◽  
Tonsillar Hyperplasia

Abstract Oral microbes have the capacity to spread throughout the gastrointestinal system and are strongly associated with multiple diseases. Given that tonsils are located between the oral cavity and the laryngopharynx at the gateway of the alimentary and respiratory tracts, tonsillar tissue may also be affected by microbiota from both the oral cavity (saliva) and the alimentary tract. Here, we analyzed the distribution and association of the microbial communities in the saliva and tonsils of Korean children subjected to tonsillectomy because of tonsil hyperplasia (n = 29). The microbiome profiles of saliva and tonsils were established via 16S rRNA gene sequencing. Based on the alpha diversity indices, the microbial communities of the two groups showed high similarities. According to Spearman’s ranking correlation analysis, the distribution of Treponema, the causative bacterium of periodontitis, in saliva and tonsils was found to have a significant positive correlation. Two representative microbes, Prevotella in saliva and Alloprevotella in tonsils, were negatively correlated, while Treponema 2 showed a strong positive correlation between saliva and tonsils. Taken together, strong similarities in the microbial communities of the tonsils and saliva are evident in terms of diversity and composition. The saliva microbiome is expected to significantly affect the tonsil microbiome. Furthermore, we suggest that our study creates an opportunity for tonsillar microbiome research to facilitate the development of novel microbiome-based therapeutic strategies.

scholarly journals Influence of Sampling Site and other Environmental Factors on the Bacterial Community Composition of Domestic Washing Machines

2019 ◽  
Vol 8 (1) ◽  
pp. 30 ◽  
Author(s):  
Susanne Jacksch ◽  
Dominik Kaiser ◽  
Severin Weis ◽  
Mirko Weide ◽  
Stefan Ratering ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Bacterial Community Composition ◽  
Sampling Site ◽  
Alpha Diversity ◽  
Growth Conditions ◽  
Microbial Colonization ◽  
Rrna Gene ◽  
Washing Machines ◽  
16S Rrna Gene Pyrosequencing ◽  
Machine Parts

Modern, mainly sustainability-driven trends, such as low-temperature washing or bleach-free liquid detergents, facilitate microbial survival of the laundry processes. Favourable growth conditions like humidity, warmth and sufficient nutrients also contribute to microbial colonization of washing machines. Such colonization might lead to negatively perceived staining, corrosion of washing machine parts and surfaces, as well as machine and laundry malodour. In this study, we characterized the bacterial community of 13 domestic washing machines at four different sampling sites (detergent drawer, door seal, sump and fibres collected from the washing solution) using 16S rRNA gene pyrosequencing and statistically analysed associations with environmental and user-dependent factors. Across 50 investigated samples, the bacterial community turned out to be significantly site-dependent with the highest alpha diversity found inside the detergent drawer, followed by sump, textile fibres isolated from the washing solution, and door seal. Surprisingly, out of all other investigated factors only the monthly number of wash cycles at temperatures ≥ 60 °C showed a significant influence on the community structure. A higher number of hot wash cycles per month increased microbial diversity, especially inside the detergent drawer. Potential reasons and the hygienic relevance of this finding need to be assessed in future studies.

scholarly journals Impact of Diabetes on the Gut and Salivary IgA Microbiomes

2020 ◽  
Vol 88 (12) ◽  
Author(s):  
Eric L. Brown ◽  
Heather T. Essigmann ◽  
Kristi L. Hoffman ◽  
Noah W. Palm ◽  
Sarah M. Gunter ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Immunoglobulin A ◽  
Alpha Diversity ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
Host Immune Responses ◽  
Mucosal Surfaces ◽  
Immune Mediated ◽  
Rrna Gene Sequencing ◽  
Immune Exclusion

ABSTRACT Mucosal surfaces like those present in the lung, gut, and mouth interface with distinct external environments. These mucosal gateways are not only portals of entry for potential pathogens but also homes to microbial communities that impact host health. Secretory immunoglobulin A (SIgA) is the single most abundant acquired immune component secreted onto mucosal surfaces and, via the process of immune exclusion, shapes the architecture of these microbiomes. Not all microorganisms at mucosal surfaces are targeted by SIgA; therefore, a better understanding of the SIgA-coated fraction may identify the microbial constituents that stimulate host immune responses in the context of health and disease. Chronic diseases like type 2 diabetes are associated with altered microbial communities (dysbiosis) that in turn affect immune-mediated homeostasis. 16S rRNA gene sequencing of SIgA-coated/uncoated bacteria (IgA-Biome) was conducted on stool and saliva samples of normoglycemic participants and individuals with prediabetes or diabetes (n = 8/group). These analyses demonstrated shifts in relative abundance in the IgA-Biome profiles between normoglycemic, prediabetic, or diabetic samples distinct from that of the overall microbiome. Differences in IgA-Biome alpha diversity were apparent for both stool and saliva, while overarching bacterial community differences (beta diversity) were also observed in saliva. These data suggest that IgA-Biome analyses can be used to identify novel microbial signatures associated with diabetes and support the need for further studies exploring these communities. Ultimately, an understanding of the IgA-Biome may promote the development of novel strategies to restructure the microbiome as a means of preventing or treating diseases associated with dysbiosis at mucosal surfaces.

Effect of rice bran fermented with Saccharomyces cerevisiae and Lactobacillus plantarum on gut microbiome of mice fed high-sucrose diet

2019 ◽  
Vol 10 (7) ◽  
pp. 811-821
Author(s):  
J. Shibayama ◽  
M. Goto ◽  
T. Kuda ◽  
M. Fukunaga ◽  
H. Takahashi ◽  
...  
Keyword(s):  
Bile Acid ◽  
Rice Bran ◽  
Gut Microbiome ◽  
Control Diet ◽  
Alpha Diversity ◽  
Blood Lipid ◽  
Operational Taxonomic Unit ◽  
Rrna Gene ◽  
High Sucrose

To clarify the effect of rice bran (RB) and fermented RB (FRB) in a high-sucrose and low-dietary fibre diet on the gut microbiome, the in vitro bile acid-lowering capacity and caecal microbiota of ICR mice fed with 20% RB or FRB diets for two weeks were determined. The caecal microbiome was analysed by 16S rRNA gene amplicon sequencing. The in vitro bile acid-lowering capacity was high for FRB. In mouse experiments, triacylglycerol and total cholesterol were generally lower with FRB, although the faecal frequency was highest in mice fed with RB. The Shannon-Wiener and Simpson’s indices for alpha-diversity in the microbiome of mice fed with RB and FRB, were higher than mice fed the control diet. At the phylum level in the caecal microbiome, Firmicutes and Bacteroidetes were high with FRB and RB, respectively. At the operational taxonomic unit level, some bacterial groups related to diabetes and gut toxicity, such as Lachnospiraceae and Enterorhabdus mucosicola, were high for RB but not for FRB diets. These results suggest that FRB, rather than RB, intake improve the intestinal environment and blood lipid condition.

Microbial population dynamics in laboratory-scale activated sludge reactors

2002 ◽  
Vol 46 (1-2) ◽  
pp. 19-27 ◽  
Author(s):  
K. Kaewpipat ◽  
C.P.L. Grady
Keyword(s):  
Activated Sludge ◽  
Microbial Communities ◽  
System Performance ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Treatment Plant ◽  
Laboratory Scale ◽  
Rrna Gene ◽  
Significant Finding ◽  
Prokaryotic Community ◽  
Activated Sludge Systems

As a first step in understanding nonlinear dynamics in activated sludge systems, two laboratory-scale sequencing batch reactors were operated under identical conditions and changes in their microbial communities were followed through microscopic examination, macroscopic observation, and denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA gene segments from the prokaryotic community. Two experiments were performed. The first used activated sludge from a local wastewater treatment plant to start the replicate reactors. The second used the biomass from the first experiment as a source by intermixing the two and equally redistributing the biomass into the two replicate reactors. For both experiments, the two reactors behaved fairly similarly and had similar microbial communities for a period of 60 days following start-up. Beyond that, the microbial communities in the two reactors in the first experiment diverged in composition, while those in the second experiment remained fairly similar. This suggests that the degree of change occurring in replicate reactors depends upon the severity of perturbation to which they are exposed. The DGGE data showed that the bacterial communities in both experiments were highly dynamic, even though the system performance of the replicate reactors were very similar, suggesting that dynamics within the prokaryotic community is not necessarily reflected in system performance. Moreover, a significant finding from this study is that replicate activated sludge systems are not identical, although they can be very similar if started appropriately.

scholarly journals Effects of Wildfire and Harvest Disturbances on Forest Soil Bacterial Communities

2007 ◽  
Vol 74 (1) ◽  
pp. 216-224 ◽  
Author(s):  
Nancy R. Smith ◽  
Barbara E. Kishchuk ◽  
William W. Mohn
Keyword(s):  
Microbial Biomass ◽  
Microbial Communities ◽  
Community Composition ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Microbial Biomass Carbon ◽  
Bacterial Community Composition ◽  
Soil Microbial Communities ◽  
Rrna Gene ◽  
Microbial Biomass Nitrogen ◽  
Soil Microbial

ABSTRACT Wildfires and harvesting are important disturbances to forest ecosystems, but their effects on soil microbial communities are not well characterized and have not previously been compared directly. This study was conducted at sites with similar soil, climatic, and other properties in a spruce-dominated boreal forest near Chisholm, Alberta, Canada. Soil microbial communities were assessed following four treatments: control, harvest, burn, and burn plus timber salvage (burn-salvage). Burn treatments were at sites affected by a large wildfire in May 2001, and the communities were sampled 1 year after the fire. Microbial biomass carbon decreased 18%, 74%, and 53% in the harvest, burn, and burn-salvage treatments, respectively. Microbial biomass nitrogen decreased 25% in the harvest treatment, but increased in the burn treatments, probably because of microbial assimilation of the increased amounts of available NH4 + and NO3 − due to burning. Bacterial community composition was analyzed by nonparametric ordination of molecular fingerprint data of 119 samples from both ribosomal intergenic spacer analysis (RISA) and rRNA gene denaturing gradient gel electrophoresis. On the basis of multiresponse permutation procedures, community composition was significantly different among all treatments, with the greatest differences between the two burned treatments versus the two unburned treatments. The sequencing of DNA bands from RISA fingerprints revealed distinct distributions of bacterial divisions among the treatments. Gamma- and Alphaproteobacteria were highly characteristic of the unburned treatments, while Betaproteobacteria and members of Bacillus were highly characteristic of the burned treatments. Wildfire had distinct and more pronounced effects on the soil microbial community than did harvesting.

scholarly journals Diversity and characterization of lactic acid bacteria from Common Carp (Cyprinus carpio L.) intestine in winter (Northern Kazakhstan)

2020 ◽  
pp. 34-47
Author(s):  
Maira Urazova ◽  
◽  
Kunsulu Zakarya ◽  
Zinigul Sarmurzina ◽  
Gulmira Bissenova ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Common Carp ◽  
Universal Primers ◽  
Rrna Gene ◽  
Fish Farms ◽  
Commercial Fish ◽  
Freshwater Aquaculture

Currently, in Kazakhstan, chemical agents and antibiotics are widely used for treatment and prevention of fish diseases at fish farms. The use of probiotics as an alternative to antibiotics can help reduce the spread of antibiotic resistance in this area. The aim of the present study was to isolate the intestinal lactic acid bacteria of wintering carps. We assume that such bacteria can have more adaptive properties and can be used as probiotics for growing carp juveniles at fish farms. A probiotic characteristic of 22 lactic acid bacteria isolated from Common carp intestines was studied. Universal primers were used to determine the sequence of 16S rRNA gene fragments of lactic acid bacteria (LAB). Phylogenetic relationships of the isolates were estimated using the neighbor-joining (NJ) method in Mega 6,0. All identified isolates can grow in temperature range from 10° C to 37° C and in presence of bile salt. The isolated bacteria were screened for antibacterial activity, resistance to bile, resistance to antibiotics and growth at low temperatures. All isolates were tested in vitro for their ability to inhibit the growth of Shewanella xiamenensis, Pseudomonas taiwanensis, Ps. aeruginosa and Aeromonas punctata. As a result, 7 isolates with strong antagonistic activity were selected. 16S rDNA gene sequencing identified 4 isolates as Lactobacillus fermentum, 2 - as L. casei/paracasei and 1 - as Pediococcus pentosaceus. Antibiotic resistance profile of selected strains was studied, too. This study is the first attempt for Kazakhstan to isolate and study the representatives of the normal intestinal microflora of commercial fish species. Selective strains could be potential probiotics for freshwater aquaculture practices in Kazakhstan.

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