Project description:Polymyxin B is considered as a last-resort antibiotic for multidrug-resistant or extensively drug-resistant gram-negative bacterial infections. Addressing Salmonella resistance to polymyxin B is crucial for global public health. In this study, transcriptomic detection and analysis were used to clarify the mechanisms by which CpxA-deleted S.typhimurium is involved in resistance to polymyxin B stress, which may be related to processes such as increased assembly of bacterial flagella.
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:Tuberculosis (TB) remains one of the world’s major infectious diseases affecting nations with limited public health resources. Multidrug resistance development has seriously compromised therapeutic treatment choices. The pathology of latent TB shows evidence of a reservoir of Mycobacterium tuberculosis (Mtb) in the lungs of affected individuals. If the pathogen is contained by the immune system, no overt disease symptoms occur. The environmental and internal triggers leading to disease reactivation are not well understood. Proteomic investigations of blood plasma and sputum derived from subjects with active TB versus latent TB versus healthy individuals may yield new biomarkers and, when surveying larger longitudinally monitored cohorts, may discriminate infection outcomes in an endemic setting.
Project description:Wastewater treatment plants (WWTPs) and Drinking water treatment plants (DWTPs) are critical points for public health for persistently remaining microorganisms after treatment may pose a risk. This study aimed to conduct microbial metagenomic analyses on waters from both DWTPs and WWTPs under the Istanbul Water and Sewerage Administration (ISKI). In this study a total of 52 samples were included, comprising 18 samples from DWTPs and 34 from WWTPs. All water samples underwent pre-isolation filtration. DNA isolation was conducted using filter material, followed by library preparation and sequencing on a NovaSeq 6000 instrument following the manufacturer's guidelines.
Project description:Staphylococcus aureus can infect a wide range of animals and pose as a serious threat to public health by transferring via animals or animal-derived food stuff. Even more importantly, multiple drug resistance development in the bacteria has resulted in therapeutic failure of a number of antibiotics. Therefore by realizing the need of time, this study was designed to investigate the underlying mechanisms of virulence and resistance in S. aureus. After screening through in vivo and in vitro virulence assays and susceptibility test, a highly virulent and multidrug resistant MRSA strain was selected for differential analysis by RNA-seq technology and gene expression results were verified by RT-qPCR. Up-regulation of crucial regulators like sarA and KdpDE seemed to play role in decreased expression of many exotoxin genes while enhanced the adhesion and cell wall protein expression, leading to strong biofilm production in the presence of inactivated agr system. In addition to resistance genes like blaZ, ermC and femA, up-regulation of vraS and multidrug ABC transporter genes contributed to the multidrug resistance in MRSA. Fluoroquinolone resistance was attributed to mutational changes in gyrA and parC genes. Our findings suggested that many virulence and resistance determinants in S. aureus are controlled by complex network of various regulators, and sarA is the most important of those as it adds to pathogenicity of the bacteria and ensures its survival in diverse environment. Further investigations are required to unveil these mechanisms in S. aureus. Four samples were analysed including 2 MRSA1679a test strain and 2 reference strain ATCC1 samples with two replicates of each.