Raw wastewater can contain high levels of antibiotic resistance genes (ARGs), making municipal wastewater treatment plants (WWTPs) critical for the control of the release of ARGs into the ...environment. The objective of this study was to investigate how individual treatment steps in two tertiary WWTPs affected the removal (copies/mL) and relative abundance of ARGs (copies/copies 16S rRNA genes). Nine ARG markers, representing resistance to commonly used antibiotics, as well as one integron gene (intl1) to assess ARG mobility potential, were quantified using quantitative real-time PCR (qPCR). Both WWTPs met provincial effluent regulations for removal of carbonaceous oxygen demand (CBOD5) and total suspended solids. Eight of the ten ARG markers (intl1, sul1, sul2, tet(O), ermB, blaCTX-M, blaTEM, qnrS) were detected in all samples. In contrast, mecA was detected intermittently and vanA remained below the detection limit in all samples. The total ARG marker abundances decreased by log 1.77 (p < 0.05) in the plant using an aerated lagoon (AL), and by 2.69 logs (p < 0.05) through treatment in the plant employing a biological nutrient removal (BNR) system. The BNR and secondary clarifier steps in both plants afforded the most removal of ARGs. The relative abundance of ARGs remained unchanged at the AL plant and showed a decreasing trend at the BNR plant. Levels of CBOD5, nitrate and the human Bacteroides fecal marker correlated with ARG concentrations, suggesting these variables may be useful in predicting ARG removal. In conclusion, the effluent coming from the WWTPs contained eight of the studied ARG markers in concentrations ranging from 0.01 to 3.6 log copies/mL, indicating their release into the environment, however, the relative abundance of ARGs was not enriched during treatment in the two WWTPs.
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•Tertiary wastewater treatment reduced effluent antibiotic resistance genes (ARGs) concentration.•BNR reactors and secondary clarifiers effected significant removal of ARGs.•ARG removal was modest in the aerated lagoons.•Microorganisms with ARGs were not enriched during wastewater treatment.•Removal of ARGs, nutrients and the human Bacteroides fecal indicator correlated.
To estimate minimally important differences (MIDs) on the Functional Assessment of Cancer Therapy–Colorectal (FACT-C) instrument using anchor- and distribution-based methods.
Preliminary MIDs were ...generated for FACT-C scores based on published results for two samples (
n = 60 and
n = 63) from the FACT-C validation study. Preliminary MIDs were confirmed using data from a Phase II randomized controlled clinical trial (
n = 104) and a population-based observational study (
n = 568). MIDs were estimated for the colorectal cancer subscale (CCS); the FACT-C Trial Outcome Index (TOI-C), which is the sum of the CCS, physical well-being, and functional well-being subscales; and the FACT-C total score. Both cross-sectional and longitudinal analyses were used.
MIDs were stable across the different patient samples. The recommended MIDs ranged from 2 to 3 points for the CCS, 4 to 6 points for the TOI-C, and 5 to 8 points for the FACT-C total score.
MIDs can enhance the interpretability of FACT-C scores, and they can be used to provide a basis for sample size estimation and to determine clinical benefit in combination with other measures of efficacy. General guidelines for estimating MIDs for other FACT instruments are suggested.
Abstract
Horizontal transfer of the integrative and conjugative element ICEMlSymR7A converts non-symbiotic Mesorhizobium spp. into nitrogen-fixing legume symbionts. Here, we discover subpopulations ...of Mesorhizobium japonicum R7A become epigenetically primed for quorum-sensing (QS) and QS-activated horizontal transfer. Isolated populations in this state termed R7A* maintained these phenotypes in laboratory culture but did not transfer the R7A* state to recipients of ICEMlSymR7A following conjugation. We previously demonstrated ICEMlSymR7A transfer and QS are repressed by the antiactivator QseM in R7A populations and that the adjacently-coded DNA-binding protein QseC represses qseM transcription. Here RNA-sequencing revealed qseM expression was repressed in R7A* cells and that RNA antisense to qseC was abundant in R7A but not R7A*. Deletion of the antisense-qseC promoter converted cells into an R7A*-like state. An adjacently coded QseC2 protein bound two operator sites and repressed antisense-qseC transcription. Plasmid overexpression of QseC2 stimulated the R7A* state, which persisted following curing of this plasmid. The epigenetic maintenance of the R7A* state required ICEMlSymR7A-encoded copies of both qseC and qseC2. Therefore, QseC and QseC2, together with their DNA-binding sites and overlapping promoters, form a stable epigenetic switch that establishes binary control over qseM transcription and primes a subpopulation of R7A cells for QS and horizontal transfer.
Foods and related processing environments are commonly contaminated with the pathogenic Listeria monocytogenes. To investigate potential environmental reservoirs of Listeria spp. and L. ...monocytogenes, surface water and point source pollution samples from an urban and a rural municipal water supply watershed in Nova Scotia, Canada, were examined over 18 months. Presumptive Listeria spp. were cultured from 72 and 35% of rural and urban water samples, respectively, with 24% of the positive samples containing two or three different Listeria spp. The L. innocua (56%) and L. welshimeri (43%) groups were predominant in the rural and urban watersheds, respectively. Analysis by the TaqMan assay showed a significantly (P < 0.05) higher prevalence of L. monocytogenes of 62% versus 17% by the culture-based method. Both methods revealed higher prevalences in the rural watershed and during the fall and winter seasons. Elevated Escherichia coli (≥ 100 CFU/100 ml) levels were not associated with the pathogen regardless of the detection method. Isolation of Listeria spp. were associated with 70 times higher odds of isolating L. monocytogenes (odds ratio = 70; P < 0.001). Serogroup IIa was predominant (67.7%) among the 285 L. monocytogenes isolates, followed by IVb (16.1%), IIb (15.8%), and IIc (0.4%). L. monocytogenes was detected in cow feces and raw sewage but not in septic tank samples. Pulsotyping of representative water (n = 54) and local human (n = 19) isolates suggested genetic similarities among some environmental and human L. monocytogenes isolates. In conclusion, temperate surface waters contain a diverse Listeria species population and could be a potential reservoir for L. monocytogenes, especially in rural agricultural watersheds.
Background
Lymphedema is a frequent complication after surgical treatment in gynecological oncology with substantial impact on patients´ Quality of Life (QoL). Little is known about screening ...instruments and prevention. Primary objective was to develop and validate the German version of a 13 items screening questionnaire (SQ) developed by Yost et al. to provide a valid instrument for early diagnosis of lower extremity lymphedema (LEL).
Methods
After translation the SQ was used in pt. with cervical or endometrial cancer who underwent pelvic/paraaortic Lymphadenectomy. Sensitivity and specifity were analysed regarding possible prediction and influencing factors of LEL.
Results
67 pt. had LEL (
N
= 128). Nearly 50% of women in each group (38 in LEL + e 30 in LEL − ) had a body mass index (BMI) > 30 kg/m
2
. Number of removed lymphnodes, radiotherapy and were significantly associated with development of LEL. Translated Mayo Clinic questionnaire can be used with reliable specifity and sensitivity. Four additional questions improved the diagnostic accuracy of the SQ.
Conclusions
The translated SQ is a valuable and predictive tool for screening and early detection of LEL in Gynecological cancer surgery and can even improved by adding simple questions.
Wastewater treatment plays an essential role in minimizing negative impacts on downstream aquatic environments. Microbial communities are known to play a vital role in the wastewater treatment ...process, particularly in the removal of nitrogen and phosphorus, which can be especially damaging to aquatic ecosystems. There is limited understanding of how these microbial communities may change in response to fluctuating temperatures or how seasonality may impact their ability to participate in the treatment process. The findings of this study indicate that the microbial communities of wastewater are relatively stable both compositionally and functionally across fluctuating temperatures.
Prevalence of antibiotic resistance in the environment is of critical concern from a public health perspective, with many human impacted environments showing increased incidence of antibiotic ...resistant bacteria. Wastewater treatment environments are of particular interest due to their high levels of antibiotic residuals, which can select for antibiotic resistance genes in bacteria. However, wastewater treatment plants are generally not designed to remove antibiotics from collected waste, and many of the currently proposed methods are unsafe for environmental use. This has prompted researchers to identify alternative environmentally safe methods for removing antibiotics from wastewater to be used in parallel with conventional wastewater treatment, as it is a potential strategy towards the mitigation of environmental antibiotic resistance selection. This paper reviews several methods developed to absorb and/or degrade antibiotics from aqueous solutions and wastewater biosolids, which includes ligninolytic fungi and ligninolytic enzymes, algae-driven photobioreactors and algae-activated sludge, and organically-sourced biochars.
•Antibiotic pollution in wastewater treatment facilities can select for antibiotic resistance genes in bacterial pathogens.•Removal of antibiotic residues from wastewater using ligninolytic fungi, microalgae, and biochars were summarized.•A combination of methods may be necessary to target the variety of antibiotic classes detected within wastewater.•Further research is needed before full-scale in situ implementation is possible for these alternative methods to be adopted in wastewater treatment plants.
Canada geese (Branta canadensis) are prevalent in North America and may contribute to fecal pollution of water systems where they congregate. This work provides two novel real-time PCR assays ...(CGOF1-Bac and CGOF2-Bac) allowing for the specific and sensitive detection of Bacteroides 16S rRNA gene markers present within Canada goose feces.
Two-component signal transduction systems (TCS) are a main strategy used by bacteria to sense and adapt to changes in their environment. In the legume symbiont Rhizobium leguminosarum biovar viciae ...VF39, mutation of chvG, a histidine kinase, caused a number of pleiotropic phenotypes. ChvG mutants are unable to grow on proline, glutamate, histidine, or arginine as the sole carbon source. The chvG mutant secreted smaller amounts of acidic and neutral surface polysaccharides and accumulated abnormally large amounts of poly-ss-hydroxybutyrate. Mutation of chvG caused symbiotic defects on peas, lentils, and vetch; nodules formed by the chvG mutant were small and white and contained only a few cells that had failed to differentiate into bacteroids. Mutation of chvG also destabilized the outer membrane of R. leguminosarum, resulting in increased sensitivity to membrane stressors. Constitutive expression of ropB, the outer membrane protein-encoding gene, restored membrane stability and rescued the sensitivity phenotypes described above. Similar phenotypes have been described for mutations in other ChvG-regulated genes encoding a conserved operon of unknown function and in the fabXL genes required for synthesis of the lipid A very-long-chain fatty acid, suggesting that ChvG is a key component of the envelope stress response in Rhizobium leguminosarum. Collectively, the results of this study demonstrate the important and unique role the ChvG/ChvI TCS plays in the physiology, metabolism, and symbiotic competency of R. leguminosarum.
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