Responses of Bacterial Taxonomical Diversity Indicators to Pollutant Loadings in Experimental Wetland Microcosms

Urbanization results in higher stormwater loadings of pollutants such as metals and nutrients into surface waters. This directly impacts organisms in aquatic ecosystems, including microbes. Sediment microbes are known for pollution reduction in the face of contamination, making bacterial communities an important area for bioindicator research. This study explores the pattern of bacterial responses to metal and nutrient pollution loading and seeks to evaluate whether bacterial indicators can be effective as a biomonitoring risk assessment tool for wetland ecosystems. Microcosms were built containing sediments collected from wetlands in the urbanizing Pike River watershed in southeastern Wisconsin, USA, with metals and nutrients added at 7 day intervals. Bacterial DNA was extracted from the microcosm sediments, and taxonomical profiles of bacterial communities were identified up to the genera level by sequencing 16S bacterial rRNA gene (V3–V4 region). Reduction of metals (example: 90% for Pb) and nutrients (example: 98% for NO3−) added in water were observed. The study found correlations between diversity indices of genera with metal and nutrient pollution as well as identified specific genera (including Fusibacter, Aeromonas, Arthrobacter, Bacillus, Bdellovibrio, and Chlorobium) as predictive bioindicators for ecological risk assessment for metal pollution.

Endurance Training in Humans Modulates the Bacterial DNA Signature of Skeletal Muscle

Accumulating evidence supports the existence of a tissue microbiota, which may regulate the physiological function of tissues in normal and pathological states. To gain insight into the regulation of tissue-borne bacteria in physiological conditions, we quantified and sequenced the 16S rRNA gene in aseptically collected skeletal muscle and blood samples from eight healthy male individuals subjected to six weeks of endurance training. Potential contamination bias was evaluated and the taxa profiles of each tissue were established. We detected bacterial DNA in skeletal muscle and blood, with background noise levels of detected bacterial DNA considerably lower in control versus tissue samples. In both muscle and blood, Proteobacteria, Actinobacteria, Firmicutes and Bacteroidetes were the most prominent phyla. Endurance training changed the content of resident bacterial DNA in skeletal muscle but not in blood, with Pseudomonas being less abundant, and both Staphylococcus and Acinetobacter being more abundant in muscle after exercise. Our results provide evidence that endurance training specifically remodels the bacterial DNA profile of skeletal muscle in healthy young men. Future investigations may shed light on the physiological impact, if any, of training-induced changes in bacterial DNA in skeletal muscle.

Delivery Mode Shapes the Composition of the Lower Airways Microbiota in Newborns

Radical alterations in the human microbiota composition are well-known to be associated with many pathological conditions. If these aberrations are established at the time of birth, the risk of developing correlated pathologies throughout life is significantly increased. For this reason, all newborns should begin their lives with a proper microbiota in each body district. The present study aimed at demonstrating a correlation between the mode of delivery and the development of a well-balanced microbiota in the lower airways of newborns. 44 pregnant women were enrolled in this study. Microbiological comparative analysis was carried out on tracheobronchial secretions of babies born through vaginal delivery (VD) or caesarean section (CS). All samples showed the presence of bacterial DNA, regardless of the mode of delivery. No viable cultivable bacteria were isolated from the CS samples. On the contrary, VD allowed colonization of the lower airways by alive cultivable bacteria. The identification of bacterial species revealed that Lactobacillus spp. and Bacteroides vulgatus were the most common microorganisms in the lower airways of vaginally-delivered newborns. Data obtained from quantitative PCRs showed a significantly higher total bacterial load, as well as Firmicutes and Lactobacillus spp. amount, in VD samples than CS ones, while no statistically significant difference was found in Torque Teno Virus (TTV) load between samples. Taken together, our findings confirm the hypothesis that passage through the maternal vaginal canal determines more beneficial colonization of the lower airways in newborns.

Nano-Metals Forming Bacteria in Egypt. II. Efficacy towards Some Bacterial Soft Rot/Blackleg Genera ex vivo and Bio-Control in vivo as Eco-Friendly Therapeutic against Dickeya Solani

The antibacterial activity of Cu, Fe, Co, and ZnNPs which were formed by Enterococcus thailandicus, Pseudomonas putida, Marinobacter hydrocarbonoclasticus, and P. geniculate sequentially was tested against some soft rot/blackleg genera. The effects of NPs were recorded on bacterial DNA, proteins, and carbohydrates concentration of Pectobacterium carotovorum, Enterobacter cloacae (soft rot), and Dickeya solani (soft rot/blackleg). Treated cells showed degradation in the DNA isolated, and a decrease in proteins, and carbohydrates concentration compared with untreated cells. The treated cells using SEM showed collapsed, and small pits in the cell wall. Internal changes using TEM showed penetration of NPs inside the tested bacterial cells, the appearance of periplasmic space, formation vacuoles, and condensation of cytoplasm. Disease severity ex vivo of tuber infected with tested genera demonstrated that NPs treatment didn't show any rotted tissue compared with untreated. FeNPs were tested to control soft rot/blackleg disease caused by D. solani in comparison with copper pesticide. Present data recorded an increase in shoot and root length, in addition to, increase in dry and fresh weight, compared with either infected or healthy plants. In studying the ability of treated potato (Solanum tuberosum) seedlings with NPs to uptake and accumulate FeNPs from the soil, ICP-OES recorded a small increase in Fe content of treated plants compared with untreated. FeNPs can be used to control soft rot/blackleg disease caused by D. solani instead of copper pesticide and can be considered as a new and alternative approach to traditional disease management methods, and also increase the nutritional value of the plants

Correlation between chronic periodontitis and rheumatoid arthritis: A periodontist perspective

In this study, we evaluate the relationship between rheumatoid arthritis (RA) and chronic periodontitis on the basis of clinical attachment present and severity of attachment loss in both the cases. First of all Diagnosis of rheumatoid arthritis and chronic periodontitis was performed, thereafter bacterial DNA extraction from blood serum sample and subgingival dental plaque of each group through PCR and later DNA purification through Spin protocol was performed, oligonucleotide primer was used to detect t.forcythia and PCR amplification was done to detect T. Denticola for both the groups .PBDNA was detected in both SGP and serum samples of both the groups. In SGP samples, Tannerella forsythia was more frequently detected as compared to serum samples of both the groups. In result theclinical attachment Level (CAL) was observed to be higher in RA group as compared to CP group. Comparison of CAL according to severity was also observed in both the groups which suggested that RA group has mild periodontitis as compared to CP group in which moderate to severe periodontitis was seen, Detection of periodontal bacterial DNA by PCR assay PBDNA was detected in both SGP and serum samples. In SGP samples, Tannerella forsythia was more frequently detected as compared to serum samples of both the groups. So these are two common chronic inflammatory diseases with a similar host-mediated pathogenesis. Current evidence suggests that an association exists between periodontitis and RA. Well-designed multicenter longitudinal clinical trials and studies with sufficient sample sizes are needed to ascertain the relationship between these two diseases and whether periodontal treatment can reduce the severity of RA or prevent its onset.

Synthesis of Adenine-based Fluorescent and Naked-eye Chemosensors: Specific DNA Probes for the Detection of Bacterial Pathogens

A rapid and confident tool to identify and diagnose bacterial pathogens with more accuracy using DNA as fingerprints is necessary. Herein, we report a smart chemosensor having a terminal adenine sticking to the thymine of single-stranded DNA (ssDNA) through supramolecular interactions and, which leaves ssDNA when the same ssDNA matches with the targeting desired DNA. We have synthesized a naked-eye coloured chemosensor with carbazole. As a model genetic material, DNA of Clavibacter michiganensis subsp. michiganensis was hybridized to ssDNA and immobilized over nitrocellulose membrane. The prepared adenine-chemosensor, by passing through the nitrocellulose-ssDNA membrane caused the formation of ssDNA nitrocellulose-ssDNA-adenine-chemosensor. FTIR results of the immobilized ssDNAs showed that the matching of same ssDNA releases the adenine-chemosensor from the surface of nitrocellulose-ssDNA that results in formation of the double stranded DNA. The selectivity of chemosensor was also confirmed with different bacterial DNA (Bacillus subtilis) as control. These data highlights accurate and reliable results of a new diagnostic kit prototype promising for further studies, which is able to diagnose DNA quickly and precisely.

Evaluation of SARS-CoV-2 in semen, seminal plasma, and spermatozoa pellet of COVID-19 patients in the acute stage of infection

To date, there is limited information about the presence of SARS-CoV-2 in semen especially in the acute phase of the infection. While available data from cohort studies including a total of 342 patients in the acute or recovery phase of the infection are reassuring, one study mentioned detecting virus in the semen of 6/38 COVID-19 patients. Here we assessed SARS-CoV-2 presence in the semen of COVID-19 positive patients in the acute stage of infection, within 24 hours of the positive nasopharyngeal swabs. Semen, seminal plasma and spermatozoa pellet were screened for SARS-CoV-2 and manual or airborne contamination during semen sampling. Among the 32 COVID-19 volunteers, the median interval from the onset of symptoms to semen collection was 4 days [IQR: 0–8]. Only one presented positive SARS-CoV-2 PCR in semen and seminal plasma fractions, although the spermatozoa pellet was negative. Viral cultures were all negative. We observed slightly higher concentrations of bacterial DNA in the SARS-CoV-2 positive specimen than in all negative samples. The bacteria identified neither confirm nor rule out contamination by oropharyngeal secretions during collection. SARS-CoV-2 was rarely present in semen during the acute phase of the disease. This very rare situation could be connected to oral or manual contamination during semen collection. The possible presence of SARS-CoV-2 in semen calls for nasopharyngeal viral testing and strict hygiene protocols during semen collection before assisted reproductive attempts.

The Viable Microbiome of Human Milk Differs from the Metataxonomic Profile

Bacteria in human milk contribute to the establishment of the infant gut microbiome. As such, numerous studies have characterized the human milk microbiome using DNA sequencing technologies, particularly 16S rRNA gene sequencing. However, such methods are not able to differentiate between DNA from viable and non-viable bacteria. The extent to which bacterial DNA detected in human milk represents living, biologically active cells is therefore unclear. Here, we characterized both the viable bacterial content and the total bacterial DNA content (derived from viable and non-viable cells) of fresh human milk (n = 10). In order to differentiate the living from the dead, a combination of propidium monoazide (PMA) and full-length 16S rRNA gene sequencing was used. Our results demonstrate that the majority of OTUs recovered from fresh human milk samples (67.3%) reflected DNA from non-viable organisms. PMA-treated samples differed significantly in their bacterial composition compared to untreated samples (PERMANOVA p < 0.0001). Additionally, an OTU mapping to Cutibacterium acnes had a significantly higher relative abundance in PMA-treated (viable) samples. These results demonstrate that the total bacterial DNA content of human milk is not representative of the viable human milk microbiome. Our findings raise questions about the validity of conclusions drawn from previous studies in which viability testing was not used, and have broad implications for the design of future work in this field.