Project description:Antibiotic-resistant bacteria can escape from the killing of host immune and settle in the host to form persistent infections. In this study, we investigated the environmental adaptation mechanism of resistant Staphyloccus aureus (S. aureus) to host environment by Data-independent acquisition based quantitative proteomics and functional validation. The detection of growth curve and MIC indicated that ciprofloxacin-resistant S. aureus (Cip-R) showed survival advantage over sensitive strain. Cip-R also exhibited stronger adhesion and invasion ability than sensitive bacteria. Cip-R stimulation resulted in the production of stronger inflammatory factors of the host cells. Proteomics study combined with biochemical validations showed that Cip-R obtains adaptability to host via up-regulation of TCA cycle and down-regulation of ribosome metabolism and protein folding to maintain energy to support their survival. Thus, this study will help us to further explain the growth strategy of resistant bacteria to adapt to the host environment, and provide important information for the development of new antibacterial drugs.
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.