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Luo Y, Chen M, Jiang Y, Wang W, Wang H, Deng L, Zhao Z. Study on the Genome and Mechanism of Tigecycline Resistance of a Clinical Chryseobacterium indologenes Strain. Microb Drug Resist 2023; 29:541-551. [PMID: 37733298 DOI: 10.1089/mdr.2023.0129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2023] Open
Abstract
Purpose: Chryseobacterium indologenes is a clinically relevant microorganism that has been on the rise, with multidrug-resistant (MDR) strains being reported. C. indologenes carrying tet(X2) has been demonstrated to be resistant to the antibiotic tigecycline, yet, sensitive to all other members of the tetracycline family. This inconsistency in resistance prompts an inquiry into the contribution of tet(X2) to tigecycline resistance in C. indologenes. Materials and Methods: In this study, we report on a comprehensive analysis of the genomic mechanisms underlying tigecycline resistance in a MDR C. indologenes strain (CI3125) that was resistant to tigecycline but sensitive to tetracycline, doxycycline, and minocycline. We used whole-genome sequencing, quantitative reverse transcription PCR, Western blot, antibiotic-degrading tests, and efflux pump inhibiting tests to reveal the mechanism of tigecycline resistance in C. indologenes and elucidate the inconsistency in the antibiotic resistance mechanism for the tetracycline family. Results: Our findings demonstrate that CI3125 carries 60 antibiotic resistance genes distributed on 6 different genetic islands (GIs), with the potential for horizontal transfer. Notably, the tet(X2) gene is located on GI06 of CI3125. Genetic environment analysis of tet(X2) showed that all tet(X2) genes in Flavobacterium and Bacteroides share a conservative and functional ribosome-binding site upstream. Contrary to expectation, our RT-qPCR showed that tet(X2) was not transcribed in CI3125, and Western blot suggested the absence of tet(X2) protein in CI3125. Rather, we demonstrate that minimum inhibitory concentration values for tigecycline decreased two- to eight-folds in the presence of five different efflux pump inhibitors [1-(1-naphthyl- methyl)-piperazine, phenyl-arginine-β-naphthylamide, verapamil, reserpine, and carbonyl cyanide 3-chlorophenylhydrazone]. This finding provides evidence for the involvement of efflux pumps in tigecycline resistance, which is likely to be a universal mechanism among C. indologenes. Our study proposes that the inconsistency in resistance to the tetracycline family in CI3125 may be ascribed to the silence of tet(X2) and the functions of efflux pumps for tigecycline. Conclusions: Overall, our results highlight the importance of genomic approaches in understanding the underlying mechanisms of antibiotic resistance in clinically relevant microorganisms. While tet(X2) in CI3125 is silent, our findings suggest that it may be horizontally spread through GIs. Hence, our findings have significant implications for the management of C. indologenes infections in clinical settings.
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Affiliation(s)
- Yi Luo
- Department of Parasitology of the Basical Medicine of Guangdong Medical University, Dongguan, China
| | - Min Chen
- Department of Parasitology of the Basical Medicine of Guangdong Medical University, Dongguan, China
| | - Yujie Jiang
- Department of Parasitology of the Basical Medicine of Guangdong Medical University, Dongguan, China
| | - Weiqi Wang
- Department of Parasitology of the Basical Medicine of Guangdong Medical University, Dongguan, China
| | - Heping Wang
- Department of Respiratory Diseases, Shenzhen Children's Hospital, Shenzhen City, China
| | - Li Deng
- Department of Parasitology of the Basical Medicine of Guangdong Medical University, Dongguan, China
| | - Zuguo Zhao
- Department of Parasitology of the Basical Medicine of Guangdong Medical University, Dongguan, China
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Irfan M, Tariq M, Basharat Z, Abid Khan RM, Jahanzaeb M, Shakeel M, Nisa ZU, Shahzad M, Jahanzaib M, Moin ST, Hassan SS, Khan IA. Genomic analysis of Chryseobacterium indologenes and conformational dynamics of the selected DD-peptidase. Res Microbiol 2023; 174:103990. [PMID: 36087828 DOI: 10.1016/j.resmic.2022.103990] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 08/27/2022] [Accepted: 08/30/2022] [Indexed: 01/11/2023]
Abstract
Chrysobacterium indologenes is an emerging MDR pathogen that belongs to the family Flavobacteriaceae. The genome of the C. indologenes, isolated from the nephrotic patient, was sequenced through Illumina MiSeq. The pangenomics of available 56 C. indologenes strains using BPGA revealed an open pangenome (n=5553 CDS), core genome (2141), and accessory genome (2013). The CEG/DEG database identified 662 essential genes that drastically reduced to 68 genes after non-homology analyses towards human and gut microbiome. Further filtering the data for other drug target prioritizing parameters resulted in 32 putative targets. Keeping in view the crucial role played in cell wall biosynthesis, dacB was selected as the final target that encodes D-alanyl-d-alanine carboxypeptidase/endopeptidase (DD-peptidase). The 3D structure of dacB was modelled and rendered to docking analyses against two compound libraries of African plants (n=6842) and Tibetan medicines (n=52). The ADMET profiling exhibited the physicochemical properties of final compounds. The MD simulations showed the stability of inhibitor-DD-peptidase complex and interactions in terms of RMSD, RMSF, binding free energy calculation and H-bonding. We propose that the novel compounds Leptopene and ZINC95486338 from our findings might be potent DD-peptidase inhibitors that could aid in the development of new antibiotic-resistant therapy for the emerging MDR C. indologenes.
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Affiliation(s)
- Muhammad Irfan
- Jamil-ur-Rahman Center for Genome Research, Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan
| | - Muhammad Tariq
- Third World Center for Science and Technology, H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan
| | - Zarrin Basharat
- Jamil-ur-Rahman Center for Genome Research, Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan.
| | - Rao Muhammad Abid Khan
- Department of Clinical Microbiology, Sindh Institute of Urology & Transplantation (SIUT), Karachi, Pakistan
| | - Muhammad Jahanzaeb
- Jamil-ur-Rahman Center for Genome Research, Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan
| | - Muhammad Shakeel
- Jamil-ur-Rahman Center for Genome Research, Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan
| | - Zaib Un Nisa
- Jamil-ur-Rahman Center for Genome Research, Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan
| | - Mohsin Shahzad
- Department of Molecular Biology, Shaheed Zulfiqar Ali Bhutto Medical University, Islamabad, Pakistan
| | - Muhammad Jahanzaib
- Jamil-ur-Rahman Center for Genome Research, Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan
| | - Syed Tarique Moin
- Third World Center for Science and Technology, H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan
| | - Syed Shah Hassan
- Jamil-ur-Rahman Center for Genome Research, Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan
| | - Ishtiaq Ahmad Khan
- Jamil-ur-Rahman Center for Genome Research, Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi-75270, Pakistan.
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