Dataset Information

Mechanisms for Development of Ciprofloxacin Resistance in a Clinical Isolate of Pseudomonas aeruginosa.

ABSTRACT: Treatment of infections by Pseudomonas aeruginosa is difficult due to its high intrinsic and acquired antibiotic resistance. Upon colonization in the human hosts, P. aeruginosa accumulates genetic mutations that confer the bacterium antibiotic resistance and ability to better live in the host environment. Characterizing the evolutionary traits would provide important insights into the development of effective combinatory antibiotic therapies to cure P. aeruginosa infections. In this work, we performed a detailed analysis of the molecular mechanisms by which a clinical isolate (CSP18) yields a ciprofloxacin-resistant derivative (CRP42). Genomic DNA re-sequencing and RNAseq were carried out to compare the genomic mutational signature and transcriptional profiles between the two isolates. The results indicated that D87G mutation in GyrA, together with MexEF-OprN hyper-expression caused by F7S mutation in MexS, was responsible for the increased resistance to ciprofloxacin in the isolate CRP42. Further simulation of CRP42 by gene editing in CSP18 demonstrated that D87G mutation in GyrA rendered CSP18 a fourfold increase in minimum inhibitory concentration against ciprofloxacin, while F7S mutation in MexS conferred an additional eightfold increase. Our experimental results demonstrate for the first time that the clinically relevant F7S point mutation in MexS results in hyper-expression of the mexEF-oprN and thus confers P. aeruginosa resistance to ciprofloxacin.

SUBMITTER: Xu C

PROVIDER: S-EPMC7819972 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Mechanisms for Development of Ciprofloxacin Resistance in a Clinical Isolate of Pseudomonas aeruginosa.

Xu Congjuan C Liu Huimin H Pan Xiaolei X Ma Zhenzhen Z Wang Dan D Zhang Xinxin X Zhu Guangbo G Bai Fang F Cheng Zhihui Z Wu Weihui W Jin Yongxin Y

Frontiers in microbiology 20210108

Treatment of infections by Pseudomonas aeruginosa is difficult due to its high intrinsic and acquired antibiotic resistance. Upon colonization in the human hosts, P. aeruginosa accumulates genetic mutations that confer the bacterium antibiotic resistance and ability to better live in the host environment. Characterizing the evolutionary traits would provide important insights into the development of effective combinatory antibiotic therapies to cure P. aeruginosa infections. ...[more]

PMID: 33488544

Similar Datasets

Project description:The spread of resistance genes via horizontal plasmid transfer plays a significant role in the formation of multidrug-resistant (MDR) Pseudomonas aeruginosa strains. Here, we identified a megaplasmid (ca. 513 kb), designated pPAG5, which was recovered from a clinical multidrug-resistant P. aeruginosa PAG5 strain. The pPAG5 plasmid belonged to the IncP-2 incompatibility group. Two large multidrug resistance regions (MDR-1 and MDR-2) and two heavy metal resistance operons (merEDACPTR and terZABCDE) were identified in the pPAG5 plasmid. Genetic analysis demonstrated that the formation of MDR regions was mediated by several homologous recombination events. Further conjugation assays identified that pPAG5 could be transferred to P. aeruginosa but not Escherichia coli. Antimicrobial susceptibility testing on transconjugants demonstrated that pPAG5 was capable of transferring resistance genes to transconjugants and producing a multidrug-resistant phenotype. Comparative analysis revealed that pPAG5 and related plasmids shared an overall similar backbone, including genes essential for replication (repA), partition (par), and conjugal transfer (tra). Further phylogenetic analysis showed that pPAG5 was closely related to plasmids pOZ176 and pJB37, both of which are members of the IncP-2-type plasmid group. IMPORTANCE The emergence and spread of plasmid-associated multidrug resistance in bacterial pathogens is a key global threat to public health. It is important to understand the mechanisms of the formation and evolution of these plasmids in patients, hospitals, and the environment. In this study, we detailed the genetic characteristics of a multidrug resistance IncP-2 megaplasmid, pPAG5, and investigated the formation of its MDR regions and evolution. To the best of our knowledge, plasmid pPAG5 is the largest multidrug resistance plasmid ever sequenced in the Pseudomonas genus. Our results may provide further insight into the formation of multidrug resistance plasmids in bacteria and the molecular evolution of plasmids.

Project description:Factor for inversion stimulation (Fis) is a versatile DNA binding protein that plays an important role in coordinating bacterial global gene expression in response to growth phases and environmental stresses. Previously, we demonstrated that Fis regulates the type III secretion system (T3SS) in Pseudomonas aeruginosa In this study, we explored the role of Fis in the antibiotic resistance of P. aeruginosa and found that mutation of the fis gene increases the bacterial susceptibility to ciprofloxacin. We further demonstrated that genes related to pyocin biosynthesis are upregulated in the fis mutant. The pyocins are produced in response to genotoxic agents, including ciprofloxacin, and the release of pyocins results in lysis of the producer cell. Thus, pyocin biosynthesis genes sensitize P. aeruginosa to ciprofloxacin. We found that PrtN, the positive regulator of the pyocin biosynthesis genes, is upregulated in the fis mutant. Genetic experiments and electrophoretic mobility shift assays revealed that Fis directly binds to the promoter region of prtN and represses its expression. Therefore, our results revealed novel Fis-mediated regulation on pyocin production and bacterial resistance to ciprofloxacin in P. aeruginosaIMPORTANCEPseudomonas aeruginosa is an important opportunistic pathogenic bacterium that causes various acute and chronic infections in human, especially in patients with compromised immunity, cystic fibrosis (CF), and/or severe burn wounds. About 60% of cystic fibrosis patients have a chronic respiratory infection caused by P. aeruginosa The bacterium is intrinsically highly resistant to antibiotics, which greatly increases difficulties in clinical treatment. Therefore, it is critical to understand the mechanisms and the regulatory pathways that are involved in antibiotic resistance. In this study, we elucidated a novel regulatory pathway that controls the bacterial resistance to fluoroquinolone antibiotics, which enhances our understanding of how P. aeruginosa responds to ciprofloxacin.

Dataset Information

Mechanisms for Development of Ciprofloxacin Resistance in a Clinical Isolate of Pseudomonas aeruginosa.

Publications

Mechanisms for Development of Ciprofloxacin Resistance in a Clinical Isolate of <i>Pseudomonas aeruginosa</i>.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets