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Sheydai F, Tukmechi A. Cell wall disruption, membrane damage, and decrease in the expression of Yrp1 virulence factor in Yersinia ruckeri by propolis ethanol extract. IRANIAN JOURNAL OF MICROBIOLOGY 2023; 15:533-540. [PMID: 38045706 PMCID: PMC10692965 DOI: 10.18502/ijm.v15i4.13507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Background and Objectives Instead of antibiotics, propolis is a promising alternative for treating bacterial diseases. The aim of this study was to evaluate the effect of propolis ethanol extract (PEE) on Yersinia ruckeri (Y. ruckeri), a fish pathogen, by examining its impact on the cell wall, cytoplasmic membrane, and gene expression. Materials and Methods The effect of propolis on the bacterial cell wall, membrane, and DNA using scanning electron microscopy (SEM) was investigated. Its effect on the NAD+/NADH ratio, reactive oxygen species (ROS) production, as well as the expression of a virulence factor (yrp1) was also determined. Results It was demonstrated that PEE has multiple antibacterial mechanisms against Y. ruckeri involving cell wall damage, membrane lysis, and a decrease in gene expression. Conclusion The obtained results indicated that the mode of propolis action against Y. ruckeri is both structural and functional, while others showed propolis only could inactivate bacteria in a structural way.
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Affiliation(s)
- Fardin Sheydai
- Department of Microbiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran
| | - Amir Tukmechi
- Department of Microbiology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran
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Quach NT, Loan TT, Nguyen TTA, Nguyen Vu TH, Pham QA, Chu HH, Phi QT, Thuoc DV. Phenotypic and genomic characterization provide new insights into adaptation to environmental stressors and biotechnological relevance of mangrove Alcaligenes faecalis D334. Res Microbiol 2023; 174:103994. [PMID: 36240959 DOI: 10.1016/j.resmic.2022.103994] [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] [Received: 05/12/2022] [Revised: 10/05/2022] [Accepted: 10/05/2022] [Indexed: 11/07/2022]
Abstract
Alcaligenes faecalis D334 was determined in this study as a salt-tolerant bacterium isolated from mangrove sediment. In response to 6% (w/v) NaCl, strain D334 produced the highest ectoines of 14.14 wt%. To understand adaptive features to mangrove environment, strain D334 was sequenced using Pacific BioScience platform, resulting in a circular chromosome of 4.23 Mb. Of note, D334 genome harbored 81 salt-responsive genes, among which two membrane-associated genes ompc and eric were absent in 3 selected A. faecalis genomes. Apart from that, a complete pathway for ectoine and 5-hydroxyectoine synthesis was predicted. To resist 40 mM H2O2, 46 genetic determinants contributing to oxidative stress response were employed. Moreover, two operons involved in polyhydroxyalkanoate (PHA) production were identified in the D334 genome, resulting in maximum PHA content of 5.03 ± 0.04 wt% and PHA concentration of 0.13 ± 0.001 g/L. A large flagellar biosynthesis operon contributing to swimming motility was found to be conserved in D334 and 8 other A. faecalis genomes. These findings shed light for the first time on the high versatility of A. faecalis D334 genome to adapt to mangrove lifestyle and the possibility to develop D334 as an industrial platform for PHA and 5-hydroxyectoine production.
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Affiliation(s)
- Ngoc Tung Quach
- Institute of Biotechnology, Vietnam Academy of Science and Technology, Hanoi 100000, Viet Nam; Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi 100000, Viet Nam
| | - Tran Thi Loan
- Department of Microbiology, Faculty of Biology, University of Science, Vietnam National University, Hanoi (VNU), Hanoi 100000, Viet Nam; Department of Biotechnology and Microbiology, Faculty of Biology, Hanoi National University of Education, Hanoi 100000, Viet Nam
| | - Thi Thu An Nguyen
- Institute of Biotechnology, Vietnam Academy of Science and Technology, Hanoi 100000, Viet Nam
| | - Thi Hanh Nguyen Vu
- Institute of Biotechnology, Vietnam Academy of Science and Technology, Hanoi 100000, Viet Nam; Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi 100000, Viet Nam
| | - Quynh Anh Pham
- Institute of Biotechnology, Vietnam Academy of Science and Technology, Hanoi 100000, Viet Nam
| | - Hoang Ha Chu
- Institute of Biotechnology, Vietnam Academy of Science and Technology, Hanoi 100000, Viet Nam; Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi 100000, Viet Nam
| | - Quyet-Tien Phi
- Institute of Biotechnology, Vietnam Academy of Science and Technology, Hanoi 100000, Viet Nam; Graduate University of Science and Technology, Vietnam Academy of Science and Technology, Hanoi 100000, Viet Nam.
| | - Doan Van Thuoc
- Department of Biotechnology and Microbiology, Faculty of Biology, Hanoi National University of Education, Hanoi 100000, Viet Nam.
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Outer membrane protein of OmpF contributes to swimming motility, biofilm formation, osmotic response as well as the transcription of maltose metabolic genes in Citrobacter werkmanii. World J Microbiol Biotechnol 2022; 39:15. [PMID: 36401137 DOI: 10.1007/s11274-022-03458-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 11/02/2022] [Indexed: 11/20/2022]
Abstract
Bacterial outer membrane proteins (Omps) are essential for environmental sensing, stress responses, and substance transport. Our previous study discovered that OmpA contributes to planktonic growth, biocide resistance, biofilm formation, and swimming motility in Citrobacter werkmanii, whereas the molecular functions of OmpF in this strain are largely unknown. Thus, in this study, the ompF gene was firstly knocked out from the genome of C. werkmanii using a homologous recombination method, and its phenotypical alternations of ∆ompF were then thoroughly characterized using biochemical and molecular approaches with the parental wild type (WT) and complementary (∆ompF-com) strains. The results demonstrated that the swimming ability of ∆ompF on semi-solid plates was reduced compared to WT due to the down-regulation of flgC, flgH, fliK, and fliF. Meanwhile, ompF deletion reduces biofilm formation on both glass and polystyrene surfaces due to decreased cell aggregation. Furthermore, ompF inactivation induced different osmotic stress (carbon sources and metal ions) responses in its biofilms when compared to WT and ∆ompF-com. Finally, a total of 6 maltose metabolic genes of lamB, malE, malK, malG, malM, and malF were all up-regulated in ∆ompF. The gene knockout and HPLC results revealed that the MalEFGK2 cluster was primarily responsible for maltose transport in C. werkmanii. Furthermore, we discovered for the first time that the upstream promoter of OmpF and its transcription can be combined with and negatively regulated by MalT. Overall, OmpF plays a role in a variety of biochemical processes and molecular functions in C. werkmanii, and it may even act as a targeted site to inhibit biofilm formation.
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The RNA Chaperone Hfq Participates in Persistence to Multiple Antibiotics in the Fish Pathogen Yersinia ruckeri. Microorganisms 2021; 9:microorganisms9071404. [PMID: 34209738 PMCID: PMC8308036 DOI: 10.3390/microorganisms9071404] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 06/11/2021] [Accepted: 06/25/2021] [Indexed: 11/16/2022] Open
Abstract
Yersinia ruckeri causes outbreaks of enteric redmouth disease in salmon aquaculture all over the world. The transient antibiotic tolerance exhibited by bacterial persisters is commonly thought to be responsible for outbreaks; however, the molecular factors underlying this behavior have not been explored in Y. ruckeri. In this study, we investigated the participation of the RNA chaperone Hfq from Y. ruckeri in antibiotic persistence. Cultures of the hfq-knockout mutant (Δhfq) exhibited faster replication, increased ATP levels and a more reductive environment than the wild type. The growth curves of bacteria exposed to sublethal concentrations of ampicillin, oxolinic acid, ciprofloxacin and polymyxin B revealed a greater susceptibility for the Δhfq strain. The time-kill curves of bacteria treated with the antibiotics mentioned above and florfenicol, using inoculums from exponential, stationary and biofilm cultures, demonstrated that the Δhfq strain has significant defects in persister cells production. To shed more light on the role of Hfq in antibiotic persistence, we analyzed its dependence on the (p)ppGpp synthetase RelA by determining the persister cells production in the absence of the relA gene. The ΔrelA and ΔrelAΔhfq strains displayed similar defects in persister cells formation, but higher than Δhfq strain. Similarly, stationary cultures of the ΔrelA and ΔrelAΔhfq strains exhibited comparable levels of ATP but higher than that of the Δhfq strain, indicating that relA is epistatic over hfq. Taken together, our findings provide valuable information on antibiotic persistence in Y. ruckeri, shedding light on the participation of Hfq in the persistence phenomenon.
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Bystritskaya E, Chernysheva N, Stenkova A, Guzev K, Rakin A, Isaeva M. Differential Expression of Yersinia pseudotuberculosis General Porin Genes during Short- and Long-Term Antibiotic Stresses. Molecules 2021; 26:3956. [PMID: 34203552 PMCID: PMC8272246 DOI: 10.3390/molecules26133956] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 06/21/2021] [Accepted: 06/23/2021] [Indexed: 11/25/2022] Open
Abstract
Here, we investigated general porin regulation in Yersinia pseudotuberculosis 488, the causative agent of Far Eastern scarlet-like fever, in response to sublethal concentrations of antibiotics. We chose four antibiotics of different classes and measured gene expression using qRT-PCR and GFP reporter systems. Our data showed temporal regulation of the general porin genes ompF and ompC caused by antibiotic stress. The porin transcription initially decreased, providing early defensive response of the bacterium, while it returned to that of the untreated cells on prolonged antibiotic exposure. Unlike the major porin genes, the transcription of the alternative porin genes ompX and lamB was increased. Moreover, a short-term ompR- and marA-mediated porin regulation was observed. The main finding was a phenotypic heterogeneity of Y. pseudotuberculosis population manifested in variable porin gene expression under carbenicillin exposure. This may offer adaptive fitness advantages for a particular bacterial subpopulation.
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Affiliation(s)
- Evgeniya Bystritskaya
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 Let Vladivostoku, 690022 Vladivostok, Russia; (E.B.); (N.C.); (K.G.)
| | - Nadezhda Chernysheva
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 Let Vladivostoku, 690022 Vladivostok, Russia; (E.B.); (N.C.); (K.G.)
| | - Anna Stenkova
- School of Biomedicine, Far Eastern Federal University, 8 Sukhanova St., 690090 Vladivostok, Russia;
| | - Konstantin Guzev
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 Let Vladivostoku, 690022 Vladivostok, Russia; (E.B.); (N.C.); (K.G.)
| | - Alexander Rakin
- Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Institute for Bacterial Infections and Zoonoses, Naumburger Str. 96a, D-07743 Jena, Germany;
| | - Marina Isaeva
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 Let Vladivostoku, 690022 Vladivostok, Russia; (E.B.); (N.C.); (K.G.)
- School of Biomedicine, Far Eastern Federal University, 8 Sukhanova St., 690090 Vladivostok, Russia;
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García-Torrico AI, Guijarro JA, Cascales D, Méndez J. Changes in physiology and virulence during the selection of resistant Yersinia ruckeri mutants under subinhibitory cefotaxime concentrations. JOURNAL OF FISH DISEASES 2019; 42:1687-1696. [PMID: 31617230 DOI: 10.1111/jfd.13086] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 08/24/2019] [Accepted: 08/26/2019] [Indexed: 06/10/2023]
Abstract
Bacterial antibiotic resistance is one of the main healthcare problems currently. Apart from reducing antibiotic efficacy, it has awakened the interest of scientists due to its association with bacterial fitness and virulence. Interestingly, antibiotic resistance can be a source of both increased fitness and decreased fitness, even though the molecular basis of these relationships remains unknown. The aim of this work is to define the effects of sub-MIC concentrations of cefotaxime, an antibiotic extensively used in clinical practice, on the physiology and virulence of Yersinia ruckeri and to determine the importance of these sub-MIC concentrations for the selection of antibiotic-resistant mutants in the aquatic environment. Results indicated that exposure to sub-MIC concentrations of cefotaxime selected Y. ruckeri populations with irreversible alterations in the physiology, such as slow growth, aggregation in liquid cultures and modification of the colony morphology. These bacteria also displayed changes in the OMPs and LPS profiles and a full attenuation of virulence. An overexpression of the envelope stress regulator RpoE was also detected after exposure to the antibiotic. In conclusion, exposure to cefotaxime selected, at high frequency, Y. ruckeri strains that survive the antibiotic stress at the expense of a fitness cost and the loss of virulence.
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Affiliation(s)
- Ana Isabel García-Torrico
- Área de Microbiología, Departamento de Biología Funcional, Facultad de Medicina, IUBA, Universidad de Oviedo, Oviedo, Spain
| | - José A Guijarro
- Área de Microbiología, Departamento de Biología Funcional, Facultad de Medicina, IUBA, Universidad de Oviedo, Oviedo, Spain
| | - Desirée Cascales
- Área de Microbiología, Departamento de Biología Funcional, Facultad de Medicina, IUBA, Universidad de Oviedo, Oviedo, Spain
| | - Jessica Méndez
- Área de Microbiología, Departamento de Biología Funcional, Facultad de Medicina, IUBA, Universidad de Oviedo, Oviedo, Spain
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Guo L, Huang L, Su Y, Qin Y, Zhao L, Yan Q. secA, secD, secF, yajC, and yidC contribute to the adhesion regulation of Vibrio alginolyticus. Microbiologyopen 2017; 7:e00551. [PMID: 29057613 PMCID: PMC5911994 DOI: 10.1002/mbo3.551] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 08/26/2017] [Accepted: 09/18/2017] [Indexed: 11/30/2022] Open
Abstract
Vibrio alginolyticus caused great losses to aquaculture. Adhesion is an important virulence factor of V. alginolyticus. In this study, the relationship between V. alginolyticus adhesion and type II secretion system genes (secA, secD, secF, yajC, and yidC) was determined using gene silencing, qRT‐PCR and in vitro adhesion assay. The results showed that the expression of target genes and the bacterial adhesion exhibited significant decreases after transient gene silencing and stable gene silencing, which indicated that secA, secD, secF, yajC, and yidC played roles in the bacterial adhesion of V. alginolyticus. The expression of secA, secD, secF, yajC, and yidC were significantly influenced by temperature, salinity, pH and starvation. The results indicated that the expression of secA, secD, secF, yajC, and yidC were sensitive to different environmental factors, whereas environmental factors can affect V. alginolyticus adhesion via the expression of secA, secD, secF, yajC, and yidC.
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Affiliation(s)
- Lina Guo
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, China
| | - Lixing Huang
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, China
| | - Yongquan Su
- State Key Laboratory of Large Yellow Croaker Breeding, Ningde, Fujian, China.,College of Ocean & Earth Sciences, Xiamen University, Xiamen, Fujian, China
| | - Yingxue Qin
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, China
| | - Lingmin Zhao
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, China
| | - Qingpi Yan
- Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, Fujian, China.,State Key Laboratory of Large Yellow Croaker Breeding, Ningde, Fujian, China
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Kumar G, Hummel K, Welch TJ, Razzazi-Fazeli E, El-Matbouli M. Global proteomic profiling of Yersinia ruckeri strains. Vet Res 2017; 48:55. [PMID: 28931430 PMCID: PMC5607619 DOI: 10.1186/s13567-017-0460-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 09/06/2017] [Indexed: 11/10/2022] Open
Abstract
Yersinia ruckeri is the causative agent of enteric redmouth disease (ERM) of salmonids. There is little information regarding the proteomics of Y. ruckeri. Herein, we perform whole protein identification and quantification of biotype 1 and biotype 2 strains of Y. ruckeri grown under standard culture conditions using a shotgun proteomic approach. Proteins were extracted, digested and peptides were separated by a nano liquid chromatography system and analyzed with a high-resolution hybrid triple quadrupole time of flight mass spectrometer coupled via a nano ESI interface. SWATH-MS technology and sophisticated statistical analyses were used to identify proteome differences among virulent and avirulent strains. GO annotation, subcellular localization, virulence proteins and antibiotic resistance ontology were predicted using bioinformatic tools. A total of 1395 proteins were identified in the whole cell of Y. ruckeri. These included proteases, chaperones, cell division proteins, outer membrane proteins, lipoproteins, receptors, ion binding proteins, transporters and catalytic proteins. In virulent strains, a total of 16 proteins were upregulated including anti-sigma regulatory factor, arginine deiminase, phosphate-binding protein PstS and superoxide dismutase Cu-Zu. Additionally, several virulence proteins were predicted such as Clp and Lon pro-teases, TolB, PPIases, PstS, PhoP and LuxR family transcriptional regulators. These putative virulence proteins might be used for development of novel targets for treatment of ERM in fish. Our study represents one of the first global proteomic reference profiles of Y. ruckeri and this data can be accessed via ProteomeXchange with identifier PXD005439. These proteomic profiles elucidate proteomic mechanisms, pathogenicity, host-interactions, antibiotic resistance ontology and localization of Y. ruckeri proteins.
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Affiliation(s)
- Gokhlesh Kumar
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.
| | - Karin Hummel
- VetCore Facility for Research/Proteomics Unit, University of Veterinary Medicine, Vienna, Austria
| | - Timothy J Welch
- National Center for Cool and Cold Water Aquaculture, Kearneysville, USA
| | - Ebrahim Razzazi-Fazeli
- VetCore Facility for Research/Proteomics Unit, University of Veterinary Medicine, Vienna, Austria
| | - Mansour El-Matbouli
- Clinical Division of Fish Medicine, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria
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Novikova OD, Chistyulin DK, Khomenko VA, Sidorin EV, Kim NY, Sanina NM, Portnyagina OY, Solov'eva TF, Uversky VN, Shnyrov VL. Peculiarities of thermal denaturation of OmpF porin from Yersinia ruckeri. MOLECULAR BIOSYSTEMS 2017; 13:1854-1862. [DOI: 10.1039/c7mb00239d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Irreversible denaturation of membrane proteins in detergent solutions is similar to unfolding of water-soluble multidomain proteins and represents a complex, multistage process.
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Affiliation(s)
- Olga D. Novikova
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry
- Far East Branch
- Russian Academy of Sciences
- Vladivostok
- Russia
| | - Dmitry K. Chistyulin
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry
- Far East Branch
- Russian Academy of Sciences
- Vladivostok
- Russia
| | - Valentina A. Khomenko
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry
- Far East Branch
- Russian Academy of Sciences
- Vladivostok
- Russia
| | - Evgeny V. Sidorin
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry
- Far East Branch
- Russian Academy of Sciences
- Vladivostok
- Russia
| | - Natalya Yu. Kim
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry
- Far East Branch
- Russian Academy of Sciences
- Vladivostok
- Russia
| | | | - Olga Yu. Portnyagina
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry
- Far East Branch
- Russian Academy of Sciences
- Vladivostok
- Russia
| | - Tamara F. Solov'eva
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry
- Far East Branch
- Russian Academy of Sciences
- Vladivostok
- Russia
| | - Vladimir N. Uversky
- Department of Molecular Medicine
- Morsani College of Medicine
- University of South Florida
- Tampa
- USA
| | - Valery L. Shnyrov
- Departamento de Bioquimica y Biologia Molecular
- Universidad de Salamanca
- 37007 Salamanca
- Spain
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Majewski P, Wieczorek P, Ojdana D, Sieńko A, Kowalczuk O, Sacha P, Nikliński J, Tryniszewska E. Altered Outer Membrane Transcriptome Balance with AmpC Overexpression in Carbapenem-Resistant Enterobacter cloacae. Front Microbiol 2016; 7:2054. [PMID: 28066375 PMCID: PMC5179509 DOI: 10.3389/fmicb.2016.02054] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 12/07/2016] [Indexed: 11/13/2022] Open
Abstract
The growing incidence of multidrug-resistant (MDR) bacteria is an emerging challenge in modern medicine. The utility of carbapenems, considered “last-line” agents in therapy of infections caused by MDR pathogens, is being diminished by the growing incidence of various resistance mechanisms. Enterobacter cloacae have lately begun to emerge as an important pathogen prone to exhibiting multiple drug resistance. We aimed to investigate the molecular basis of carbapenem-resistance in 44 E. cloacae clinical strains resistant to at least one carbapenem, and 21 susceptible strains. Molecular investigation of 65 E. cloacae clinical strains was based on quantitative polymerase chain reaction (qPCR) allowing for amplification of ampC, ompF, and ompC transcripts, and analysis of nucleotide sequences of alleles included in MLST scheme. Co-operation of three distinct carbapenem resistance mechanisms has been reported—production of OXA-48 (5%), AmpC overproduction (97.7%), and alterations in outer membrane (OM) transcriptome balance. Carbapenem-resistant E. cloacae were characterized by (1.) downregulation of ompF gene (53.4%), which encodes protein with extensive transmembrane channels, and (2.) the polarization of OM transcriptome-balance (79.1%), which was sloped toward ompC gene, encoding proteins recently reported to possess restrictive transmembrane channels. Subpopulations of carbapenem-susceptible strains showed relatively high degrees of sequence diversity without predominant types. ST-89 clearly dominates among carbapenem-resistant strains (88.6%) suggesting clonal spread of resistant strains. The growing prevalence of pathogens resistant to all currently available antimicrobial agents heralds the potential risk of a future “post-antibiotic era.” Great efforts need to be taken to explore the background of resistance to “last resort” antimicrobials.
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Affiliation(s)
- Piotr Majewski
- Department of Microbiological Diagnostics and Infectious Immunology, Medical University of Bialystok Bialystok, Poland
| | - Piotr Wieczorek
- Department of Microbiological Diagnostics and Infectious Immunology, Medical University of Bialystok Bialystok, Poland
| | - Dominika Ojdana
- Department of Microbiological Diagnostics and Infectious Immunology, Medical University of Bialystok Bialystok, Poland
| | - Anna Sieńko
- Department of Microbiological Diagnostics and Infectious Immunology, Medical University of Bialystok Bialystok, Poland
| | - Oksana Kowalczuk
- Department of Clinical Molecular Biology, Medical University of Bialystok Bialystok, Poland
| | - Paweł Sacha
- Department of Microbiological Diagnostics and Infectious Immunology, Medical University of Bialystok Bialystok, Poland
| | - Jacek Nikliński
- Department of Clinical Molecular Biology, Medical University of Bialystok Bialystok, Poland
| | - Elżbieta Tryniszewska
- Department of Microbiological Diagnostics and Infectious Immunology, Medical University of Bialystok Bialystok, Poland
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