Oporność na antybiotyki beta-laktamowe u bakterii bytujących w oczyszczalni ścieków w Żywcu i Jeziorze Żywieckim

Antibiotic resistance has become a global problem that threatens contemporary medicine. The global spread of this phenomenon is mainly driven by mobile genetic elements bearing antibiotic resistance genes. It has been already established that environmental bacteria play a crucial role in the acquision of the genes among pathogens. Wastewater treatment plants has been recognised as hotspots for antibiotic-resistant bacteria and mobile genetic elements conferring antibiotic resistance. However, the fate of the bacteria, the genes and the mobile genetic elements in the environment remains uncetrain. Therefore the aim of the project was to evaluate the fate of the bacteria and the genes in final effluent receiving Żywieckie Lake (Poland). For this purpose samples of raw sewage, activated sludge and treated sewage were obtained from the wastewater treatment plant in Żywiec and samples of water and sediments from Żywieckie Lake were collected. Additional samples of water and sediments were collected from The Soła River upsteram the lake and they served as control. Plate counts were performed and culturable fraction of total heterotrophic bacteria and ampicillin-resistant bacteria were determined. The results confirmed statistically significant reduction of all studied bacterial fractions during the wastewater treatment process. The number of bacteria observed in the samples of The Soła River and Żywieckie Lake were considerably lower than in the samples collected from the wastewater treatment plant. The number of ampicillin-resistant bacteria was higher in sediment when compared to water samples what may suggest a possible accumulation of ampicillin-resistant bacteria in freshwater sediments. The biodiversity of microbial communities and antibiotic resistance genes relative abundance in treated sewage, water of the lake and the river were assessed by next generation sequencing on Illumina® platform. The metagenomic analysis revealed the highest microbial diversity in the water sample of Żywieckie Lake. On the other hand, the lowest diversity was observed in the water sample of The Soła, what was probably due to the dominance of two bacterial phyla. The microbial phyla represented in the studied metagenomes were typical of corresponding environments. The highest relative abundance of antibiotic resistance genes (ARGs/16S rRNA) was observed in treated sewage suggesting a considerable amount of the genes being released from the wastewater treatment plant. However, the lowest relative 1 abundance as well as the lowest diversity of the genes in the lake water, when compared to the other studied metagenomes, suggest rather negligible effect of the treated sewage release on antibiotic resistance spread within water microbial communities of the lake. The exogenous isolation method allowed to capture 56 resistance plasmids in E. coli cells. Using PCR-based replicon typing the majority of plasmids could not be classified to any incompatibility group. The classified replicons belonged to IncF and IncN groups. All IncF plasmids were isolated from water samples of The Soła the latter group was represented by vectors captured from lake sediments and treated sewage. Mobility testing revealed that the majority of plasmids isolated from the water samples of The Soła were conjugative, whereas among plasmids captured from other samples mobilizable vectors prevailed. Only 3 resistance vectors from the plasmid library were neither conjugative nor mobilizable. Susceptibility testing revealed that some of the plasmids conferred resistance to third generation cephalosporins and fluoroquinolones, whereas resistance to carbapenems, aminoglycosides and polymyxins was not observed. The isolation of resistance plasmids from the water samples of Żywieckie Lake failed suggesting lower resistance plasmid abundance in this environment. The results of the presented study revealed no obvious impact of the treated sewage release on the spread of antibiotic resistance among bacteria residing in water of the receiving lake. Furthermore, uncontrolled sewage dumping to the Soła River and Żywieckie Lake in the past as well as lower quality of water upstream the lake indicate rather protective role of the wastewater treatment plant in the studied ecosystem

Molecular basis of active cooper resistance mechanisms in Gram-negative bacteria

Copper is a metallic element that is crucial for cell metabolism; however, in extended concentrations, it is toxic for all living organisms. The dual nature of copper has forced organisms, including bacteria, to keep a tight hold on cellular copper content. This challenge has led to the evolution of complex mechanisms that on one hand enable them to deliver the essential element and on the other to protect cells against its toxicity. Such mechanisms have been found in both eukaryotic and prokaryotic cells. In bacteria a number of different systems such as extra- and intracellular sequestration, enzymatic detoxification, and metal removal from the cell enabling them to survive in the presence of high concentration of copper have been identified. Gram-negative bacteria, due to their additional compartment, need to deal with both cytoplasmic and periplasmic copper. Therefore, these bacteria have evolved intricate and precisely regulated systems which interact with each other. In this review the active mechanisms of copper resistance at their molecular level are discussed

Microbial communities from subglacial water of naled ice bodies in the forefield of Werenskioldbreen, Svalbard

We assessed the structure of microbial communities in the subglacial drainage system of the Werenskioldbreen glacier, Svalbard, which consists of three independent channels. Dome-shaped naled ice bodies that had been forming and releasing subglacial water in the glacial forefield during accumulations season were used to study glacial microbiome. We tested the hypothesis that the properties of the water transported by these channels are site-dependent and influence bacterial diversity. We therefore established the phylogenetic structure of the subglacial microbial communities using next generation sequencing (NGS) of the 16S rRNA gene and performed bioinformatics analyses. A total of 1409 OTUs (operational taxonomic units) belonged to 40 phyla; mostly Proteobacteria, Gracilibacteria, Bacteroidetes, Actinobacteria and Parcubacteria were identified. Sites located on the edge of Werenskioldbreen forefield (Angell, Kvisla) were mainly dominated by Betaproteobacteria. In the central site (Dusan) domination of Epsilonproteobacteria class was observed. Gracilibacteria (GN02) and Gammaproteobacteria represented the dominant taxa only in the sample Kvisla 2. Principal Coordinate Analysis (PCoA) of beta diversity revealed that phylogenetic profiles grouped in three different clusters according to the sampling site. Moreover, higher similarity of bacterial communities from Angell and Kvisla compared to Dusan was confirmed by cluster analysis and Venn diagrams. The highest alpha index values was measured in Dusan. Richness and phylogenetic diversity indices were significantly (p < .05) and positively correlated with pH values of subglacial water and negatively with concentration of Cl−, Br−, and NO3− anions. These anions negatively impacted the values of richness indices but positively correlated with abundance of some microbial phyla. Our results indicated that subglacial water from naled ice bodies offer the possibility to study the glacial microbiome. In the studied subglacial water, the microbial community structure was sampling site specific and dependent on the water properties, which in turn were probably influenced by the local bedrock composition

Is sewage sludge a valuable fertilizer? A soil microbiome and resistome study under field conditions

Purpose Sewage sludge land application is strongly recommended to improve soil quality and fertility despite the presence of pollutants, pathogens and antibiotic resistance genes. This study aimed to assess the fertilization value of low and recommended by law sewage sludge dose (15 t ha− 1). Materials and methods In a 540-day field study, the effect of sewage sludge on the soil physicochemical and microbial parameters, emphasising antibiotic and metal resistance spread, was investigated. Results In contrast to expectations, sewage sludge did not improve the organic matter, nutrient content and microbial activity in the soil; therefore, the fertilization effect was not achieved. Moreover, an increase in the bioavailable Cd, Ni and Cu content was observed. Canonical correspondence analysis revealed that these increases mainly explain the changes in the soil microbial community. Sixteen resistance genes and four integron classes were detected in both the total DNA and on plasmids isolated from sewage sludge. Obtained plasmids confer β-lactam resistance or extreme resistance to tetracycline (> 256 μg mL− 1). Two antibiotic resistance genes (blaNPS-2, tetA) were transferred into the fertilized soil and detected up to 6 months after the fertilization. Conclusion Our results provide evidence that the regulated dose of sewage sludge, even when characterized by low total metal content, may affect soil microbial microbiome and resistome. Therefore, these findings provide critical data that have public health implications, which may raise concerns about the suitability of applying sewage sludge to the soil even at the low regulated dose

Metagenomic Functional Profiling Reveals Differences in Bacterial Composition and Function During Bioaugmentation of Aged Petroleum-Contaminated Soil

Our objective was to study the bacterial community changes that determine enhanced removal of petroleum hydrocarbons from soils subjected to bioaugmentation with the hydrocarbon-degrading strains Rhodococcus erythropolis CD 130, CD 167, and their combination. To achieve this, a high-throughput sequencing of the 16S rRNA gene was performed. The changes in the bacterial community composition were most apparent the day after bacterial inoculation. These changes represented an increase in the percentage abundance of Rhodococcus and Pseudomonas genera. Surprisingly, members of the Rhodococcus genus were not present after day 91. At the end of the experiment, the bacterial communities from the CD 130, CD 167, and control soils had a similar structure. Nevertheless, the composition of the bacteria in the CD 130 C CD 167 soil was still distinct from the control. Metagenomic predictions from the 16S rRNA gene sequences showed that the introduction of bacteria had a significant influence on the predicted pathways (metabolism of xenobiotics, lipids, terpenoids, polyketides, and amino acids) on day one. On day 182, differences in the abundance of functional pathways were also detected in the CD 130 and CD 130 C CD 167 soils. Additionally, we observed that on day one, in all bioaugmented soils, the alkH gene was mainly contributed by the Rhodococcus and Mycobacterium genera, whereas in non-treated soil, this gene was contributed only by the Mycobacterium genus. Interestingly, from day 91, the Mycobacterium genus was the main contributor for the tested genes in all studied soils. Our results showed that hydrocarbon depletion from the analyzed soils resulted from the activity of the autochthonous bacteria. However, these changes in the composition and function of the indigenous bacterial community occurred under the influence of the introduced bacteria

Gut Microbiome in Chronic Coronary Syndrome Patients

Despite knowledge of classical coronary artery disease (CAD) risk factors, the morbidity and mortality associated with this disease remain high. Therefore, new factors that may affect the development of CAD, such as the gut microbiome, are extensively investigated. This study aimed to evaluate gut microbiome composition in CAD patients in relation to the control group. We examined 169 CAD patients and 166 people in the control group, without CAD, matched in terms of age and sex to the study group. Both populations underwent a detailed health assessment. The microbiome analysis was based on the V3–V4 region of the 16S rRNA gene (NGS method). Among 4074 identified taxonomic units in the whole population, 1070 differed between study groups. The most common bacterial types were Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria. Furthermore, a higher Firmicutes/Bacteroidetes ratio in the CAD group compared with the control was demonstrated. Firmicutes/Bacteroidetes ratio, independent of age, sex, CAD status, LDL cholesterol concentration, and statins treatment, was related to altered phosphatidylcholine concentrations obtained in targeted metabolomics. Altered alpha-biodiversity (Kruskal–Wallis test, p = 0.001) and beta-biodiversity (Bray–Curtis metric, p &lt; 0.001) in the CAD group were observed. Moreover, a predicted functional analysis revealed some taxonomic units, metabolic pathways, and proteins that might be characteristic of the CAD patients’ microbiome, such as increased expressions of 6-phospho-β-glucosidase and protein-N(pi)-phosphohistidine-sugar phosphotransferase and decreased expressions of DNA topoisomerase, oxaloacetate decarboxylase, and 6-beta-glucosidase. In summary, CAD is associated with altered gut microbiome composition and function