Project description:Incomplete antibiotic removal in pharmaceutical wastewater treatment plants (PWWTPs) could lead to the development and spread of antibiotic-resistant bacteria (ARBs) and genes (ARGs) in the environment, posing a growing public health threat. In this study, two multiantibiotic-resistant bacteria, Ochrobactrum intermedium (N1) and Stenotrophomonas acidaminiphila (N2), were isolated from the sludge of a PWWTP in Guangzhou, China. The N1 strain was highly resistant to ampicillin, cefazolin, chloramphenicol, tetracycline, and norfloxacin, while the N2 strain exhibited high resistance to ampicillin, chloramphenicol, and cefazolin. Whole-genome sequencing revealed that N1 and N2 had genome sizes of 0.52 Mb and 0.37 Mb, respectively, and harbored 33 and 24 ARGs, respectively. The main resistance mechanism in the identified ARGs included efflux pumps, enzymatic degradation, and target bypass, with the N1 strain possessing more multidrug-resistant efflux pumps than the N2 strain (22 vs 12). This also accounts for the broader resistance spectrum of N1 than of N2 in antimicrobial susceptibility tests. Additionally, both genomes contain numerous mobile genetic elements (89 and 21 genes, respectively) and virulence factors (276 and 250 factors, respectively), suggesting their potential for horizontal transfer and pathogenicity. Overall, this research provides insights into the potential risks posed by ARBs in pharmaceutical wastewater and emphasizes the need for further studies on their impact and mitigation strategies.
Project description:The study is intended to collect specimens to support the application of genome analysis technologies, including large-scale genome sequencing. This study will ultimately provide cancer researchers with specimens that they can use to develop comprehensive catalogs of genomic information on at least 50 types of human cancer. The study will create a resource available to the worldwide research community that could be used to identify and accelerate the development of new diagnostic and prognostic markers, new targets for pharmaceutical interventions, and new cancer prevention and treatment strategies. This study will be a competitive enrollment study conducted at multiple institutions.
Project description:Some plant growth promoting bacteria (PGPB) do not need to colonize plant roots to trigger the growth promotion mechanisms, as they emit volatile organic compounds (VOCs), which are small gaseous signaling molecules that mediate short- and long-distance interactions between plants and microorganisms. Therefore, VOCs-producing PGPB can be an eco-friendly solution to increase agricultural production. We aimed to understand the mechanisms underlying the VOC-mediated growth promotion effect on Setaria viridis, a model plant of C4 metabolism, by investigating its molecular, cellular, physiological and phenotypical changes triggered by these bioactive compounds. Remarkably, we screened and selected two bacteria, Pseudomonas and Burkholderia, capable of increasing the biomass of S. viridis plants by up to 4-fold in a co-cultivation system, wherein plant and bacteria only share the same atmosphere. A total of 2,871 differentially expressed genes (DEGs) were identified in S. viridis plants when exposed to VOCs from at least one of the three isolates (AI2, CTB and MTS) compared to the mock control. Then, a Gene Ontology analysis was performed. Comparing AI2 and mock treatment, 80 and 26 up- and down-regulated GOs were identified, respectively, while when comparing CTB and mock treatment, 94 up- and 36 down-regulated GOs were identified. Among these differential GOs in at least one of the growth promotion treatments compared to one or both controls we found categories like “aromatic compound biosynthetic process” (GO:0019438), “abscisic acid binding” (GO:0010427), "systemic acquired resistance" (GO:0009627), and “chitin catabolic process” (GO:0006032). Other GOs were only regulated in the treatments containing bacteria, such as “sucrose biosynthetic process” (GO:0005986), “L-phenylalanine metabolic process” (GO:0006558), “cell surface receptor signaling pathway” (GO:0007166), and “regulation of nitrogen compound metabolic process” (GO:0051171). Overall, the enrichment analysis showed a diverse spectrum of categories related to primary and secondary metabolisms, hormone pathways, enzymatic activities, plant defense and resistance, among others. Together with the other omic and target analyses, the study suggests that bacterial VOCs were able to boost photosynthesis, increasing the sugar content, that fuels respiration and cell wall modulation. Besides, VOCs were able to trigger defense response.
Project description:Previously, we investigated the effect of fungal VOCs on the behavior of phylogenetically different soil bacteria (Schmidt et al 2015). In these experiments we showed that VOCs emitted by several fungi can lead to phenotypical responses in bacteria, for example, by inducing a change in motility (Schmidt et al 2015). We observed that the plant pathogenic fungus Fusarium culmorum produced a unique cluster of VOCs consisting primarily of terpenes. When exposed to the VOCs emitted by this fungus, the rhizobacterium Serratia plymuthica PRI-2C responded with an induction of motility. It is plausible that in soil, microorganisms sense changes in their environments via shifts in VOCs blend and adapt their behavior accordingly (Garbeva et al 2014). Although several studies indicated that VOCs can be used as signaling molecules in microbial inter-species interactions, the following questions remain unanswered as how are VOCs perceived as signals by the microorganisms and which regulatory pathways and genes are involved in the response? To answer these questions, the rhizosphere isolate S. plymuthica PRI-2C was grown alone or exposed to VOCs emitted by F. culmorum. The bacterial transcriptome and proteome were analyzed under each situation to identify the molecular basis of the bacterial response to fungal VOCs.