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Hu D, Chen W, Wu J, Luo X, Yu L, Qu Y, Zhang X, Zhang J, Ma B. Coexistence of c-rmpA with p-rmpA and p-rmpA2 rather than excessive siderophores confers higher virulence in K1 Klebsiella pneumoniae. Pathology 2023; 55:1004-1012. [PMID: 37802741 DOI: 10.1016/j.pathol.2023.07.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 07/12/2023] [Accepted: 07/23/2023] [Indexed: 10/08/2023]
Abstract
Pyogenic liver abscess (PLA), which is particularly endemic in East Asia, is a relatively common and fatal infectious disease. Over the last 30-40 years, Klebsiella pneumoniae has replaced Escherichia coli as the dominant and overwhelming pathogen. To investigate the survival advantage of serotype K1 K. pneumoniae, we determined sequence types (STs), serotypes, and 11 virulence genes (allS, entB, irp2, iroN, iucA, fimH, mrkD, p-rmpA2, c-rmpA, p-rmpA, and peg-344). Virulence genes c-rmpA, p-rmpA, and p-rmpA2 in K. pneumoniae NTUH-K2044, which all confer hypercapsule and consequent hypervirulence, were deleted individually, and the consequent effects were evaluated. The lethality of various K1 K. pneumoniae strains was compared by using the Galleria mellonella model. In total, 31 K1 K. pneumoniae strains causing PLA and 30 causing non-PLA were identified. A significantly higher rate of c-rmpA was presented in PLA-derived K. pneumoniae strains than in non-PLA-derived strains. Similar ST23 (which dominates K1 strains) and string test-positive rates were observed in the two groups. Deletion of c-rmpA, p-rmpA, and p-rmpA2 individually did not confer significant effects on morphologies, such as positive string test, hypercapsule, and growth speed. Δc-rmpA presented weaker expressions of p-rmpA/p-rmpA2 than NTUH-K2044 and showed a higher expression of manC than Δp-rmpA and Δp-rmpA2. Three rmpAs conferred more virulence than one or two rmpAs, which presented an equally lethal effect in K1 K. pneumoniae. Klebsiella pneumoniae strains (H19 and H34) with the same genetic backgrounds except for siderophores showed equal virulence, but were less virulent than strain NTUH-K2044. Thus, the coexistence of c-rmpA with p-rmpA and p-rmpA2 enhances the lethality of K1 K. pneumoniae strains and the development of PLA. Excessive siderophores are not vital for the hypervirulence of K1 K. pneumoniae strains, although K1 strains usually harbour them on a molecular basis.
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Affiliation(s)
- Dakang Hu
- Department of Laboratory Medicine, Taizhou Municipal Hospital, Taizhou, Zhejiang, China
| | - Wenjie Chen
- Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Jinzuan Wu
- Department of Clinical Laboratory, Pingyang Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xinhua Luo
- Department of Laboratory Medicine, Taizhou Municipal Hospital, Taizhou, Zhejiang, China
| | - Lianhua Yu
- Department of Laboratory Medicine, Taizhou Municipal Hospital, Taizhou, Zhejiang, China
| | - Ying Qu
- Department of Laboratory Medicine, Taizhou Municipal Hospital, Taizhou, Zhejiang, China
| | - Xijiang Zhang
- Department of Critical Care Medicine, Taizhou Municipal Hospital, Taizhou, Zhejiang, China
| | - Jin Zhang
- Department of Laboratory Medicine, Taizhou Municipal Hospital, Taizhou, Zhejiang, China.
| | - Bin Ma
- School of Medical, Molecular and Forensic Sciences, Murdoch University, Murdoch, WA, Australia.
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Pu D, Zhao J, Chang K, Zhuo X, Cao B. "Superbugs" with hypervirulence and carbapenem resistance in Klebsiella pneumoniae: the rise of such emerging nosocomial pathogens in China. Sci Bull (Beijing) 2023; 68:2658-2670. [PMID: 37821268 DOI: 10.1016/j.scib.2023.09.040] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 08/19/2023] [Accepted: 09/26/2023] [Indexed: 10/13/2023]
Abstract
Although hypervirulent Klebsiella pneumoniae (hvKP) can produce community-acquired infections that are fatal in young and adult hosts, such as pyogenic liver abscess, endophthalmitis, and meningitis, it has historically been susceptible to antibiotics. Carbapenem-resistant K. pneumoniae (CRKP) is usually associated with urinary tract infections acquired in hospitals, pneumonia, septicemias, and soft tissue infections. Outbreaks and quick spread of CRKP in hospitals have become a major challenge in public health due to the lack of effective antibacterial treatments. In the early stages of K. pneumoniae development, HvKP and CRKP first appear as distinct routes. However, the lines dividing the two pathotypes are vanishing currently, and the advent of carbapenem-resistant hypervirulent K. pneumoniae (CR-hvKP) is devastating as it is simultaneously multidrug-resistant, hypervirulent, and highly transmissible. Most CR-hvKP cases have been reported in Asian clinical settings, particularly in China. Typically, CR-hvKP develops when hvKP or CRKP acquires plasmids that carry either the carbapenem-resistance gene or the virulence gene. Alternatively, classic K. pneumoniae (cKP) may acquire a hybrid plasmid carrying both genes. In this review, we provide an overview of the key antimicrobial resistance mechanisms, virulence factors, clinical presentations, and outcomes associated with CR-hvKP infection. Additionally, we discuss the possible evolutionary processes and prevalence of CR-hvKP in China. Given the wide occurrence of CR-hvKP, continued surveillance and control measures of such organisms should be assigned a higher priority.
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Affiliation(s)
- Danni Pu
- Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100730, China; Laboratory of Clinical Microbiology and Infectious Diseases, Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, National Clinical Research Center for Respiratory Diseases, National Center for Respiratory Medicine, China-Japan Friendship Hospital, Beijing 100029, China; Institute of Respiratory Medicine, Chinese Academy of Medical Sciences, Beijing 100029, China
| | - Jiankang Zhao
- Laboratory of Clinical Microbiology and Infectious Diseases, Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, National Clinical Research Center for Respiratory Diseases, National Center for Respiratory Medicine, China-Japan Friendship Hospital, Beijing 100029, China; Institute of Respiratory Medicine, Chinese Academy of Medical Sciences, Beijing 100029, China
| | - Kang Chang
- Laboratory of Clinical Microbiology and Infectious Diseases, Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, National Clinical Research Center for Respiratory Diseases, National Center for Respiratory Medicine, China-Japan Friendship Hospital, Beijing 100029, China; Institute of Respiratory Medicine, Chinese Academy of Medical Sciences, Beijing 100029, China
| | - Xianxia Zhuo
- Laboratory of Clinical Microbiology and Infectious Diseases, Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, National Clinical Research Center for Respiratory Diseases, National Center for Respiratory Medicine, China-Japan Friendship Hospital, Beijing 100029, China; Institute of Respiratory Medicine, Chinese Academy of Medical Sciences, Beijing 100029, China; Department of Pulmonary and Critical Care Medicine, Capital Medical University, Beijing 100069, China
| | - Bin Cao
- Graduate School of Peking Union Medical College, Chinese Academy of Medical Sciences, Peking Union Medical College, Beijing 100730, China; Laboratory of Clinical Microbiology and Infectious Diseases, Department of Pulmonary and Critical Care Medicine, Center of Respiratory Medicine, National Clinical Research Center for Respiratory Diseases, National Center for Respiratory Medicine, China-Japan Friendship Hospital, Beijing 100029, China; Institute of Respiratory Medicine, Chinese Academy of Medical Sciences, Beijing 100029, China; Department of Pulmonary and Critical Care Medicine, Capital Medical University, Beijing 100069, China; Tsinghua University-Peking University Joint Center for Life Sciences, Beijing 100084, China.
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Liu W, Li M, Cao S, Ishaq HM, Zhao H, Yang F, Liu L. The Biological and Regulatory Role of Type VI Secretion System of Klebsiella pneumoniae. Infect Drug Resist 2023; 16:6911-6922. [PMID: 37928603 PMCID: PMC10624183 DOI: 10.2147/idr.s426657] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 09/30/2023] [Indexed: 11/07/2023] Open
Abstract
Bacteria communicate with their surroundings through diverse secretory systems, and the recently discovered Type VI Secretion System (T6SS) has gained significant attention. Klebsiella pneumoniae (K. pneumoniae), an opportunistic pathogen known for causing severe infections in both hospital and animal settings, possesses this intriguing T6SS. This system equips K. pneumoniae with a formidable armory of protein-based weaponry, enabling the delivery of toxins into neighboring cells, thus granting a substantial competitive advantage. Remarkably, the T6SS has also been associated with K. pneumoniae's ability to form biofilms and acquire resistance against antibiotics. However, the precise effects of the T6SS on K. pneumoniae's functions remain inadequately studied, despite research efforts to understand the intricacies of these mechanisms. This comprehensive review aims to provide an overview of the current knowledge regarding the biological functions and regulatory mechanisms of the T6SS in K. pneumoniae.
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Affiliation(s)
- Wenke Liu
- Department of Pathogenic Biology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, People’s Republic of China
| | - Min Li
- Department of Pathogenic Biology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, People’s Republic of China
| | - Shiwen Cao
- Department of Pathogenic Biology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, People’s Republic of China
| | - Hafiz Muhammad Ishaq
- Faculty of Veterinary and Animal Sciences, Muhammad Nawaz Shareef University of Agriculture, Multan, Pakistan
| | - Huajie Zhao
- Department of Pathogenic Biology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, People’s Republic of China
| | - Fan Yang
- Department of Pathogenic Biology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, People’s Republic of China
| | - Liang Liu
- Department of Pathogenic Biology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, People’s Republic of China
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Li L, Ma J, Cheng P, Li M, Yu Z, Song X, Yu Z, Sun H, Zhang W, Wang Z. Roles of two-component regulatory systems in Klebsiella pneumoniae: Regulation of virulence, antibiotic resistance, and stress responses. Microbiol Res 2023; 272:127374. [PMID: 37031567 DOI: 10.1016/j.micres.2023.127374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 04/04/2023] [Accepted: 04/04/2023] [Indexed: 04/09/2023]
Abstract
Klebsiella pneumoniae is an opportunistic pathogen belonging to the Enterobacteriaceae family, which is the leading cause of nosocomial infections. The emergence of hypervirulent and multi-drug resistant K. pneumoniae is a serious health threat. In the process of infection, K. pneumoniae needs to adapt to different environmental conditions, and the two-component regulatory system (TCS) composed of a sensor histidine kinase and response regulator is an important bacterial regulatory system in response to external stimuli. Understanding how K. pneumoniae perceives and responds to complex environmental stimuli provides insights into TCS regulation mechanisms and new targets for drug design. In this review, we analyzed the TCS composition and summarized the regulation mechanisms of TCSs, focusing on the regulation of genes involved in virulence, antibiotic resistance, and stress response. Collectively, these studies demonstrated that several TCSs play important roles in the regulation of virulence, antibiotic resistance and stress responses of K. pneumoniae. A single two-component regulatory system can participate in the regulation of several stress responses, and one stress response process may include several TCSs, forming a complex regulatory network. However, the function and regulation mechanism of some TCSs require further study. Hence, future research endeavors are required to enhance the understanding of TCS regulatory mechanisms and networks in K. pneumoniae, which is essential for the design of novel drugs targeting TCSs.
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Hu D, Chen W, Wang W, Tian D, Fu P, Ren P, Mu Q, Li G, Jiang X. Hypercapsule is the cornerstone of Klebsiella pneumoniae in inducing pyogenic liver abscess. Front Cell Infect Microbiol 2023; 13:1147855. [PMID: 37065211 PMCID: PMC10102340 DOI: 10.3389/fcimb.2023.1147855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 03/14/2023] [Indexed: 04/03/2023] Open
Abstract
PurposeTo investigate the mechanisms of Klebsiella pneumoniae-induced pyogenic liver abscess (PLA).MethodsForty-three K. pneumoniae strains from PLAs and 436 from non-PLAs were collected. Their differences were compared for virulence genes and factors, sequence types, and serotypes. Virulence genes wzi, wzy-K1, and wzi+wzy-K1 were deleted in K. pneumoniae NTUH-K2044. Various analyses, such as transmission electron microscopy, neutrophil killing tests, and mouse lethality tests, were used to confirm the consequent changes.ResultsDifferences were found between K. pneumoniae strains from PLA and non-PLA samples for virulence genes and factors, including metabolism genes (allS and peg-344), capsular polysaccharide (CPS)-synthesis channel gene (wzy-K1), CPS-regulating genes (p-rmpA, p-rmpA2, and c-rmpA), and siderophore genes (iucA and iroN). When wzy-K1 was positive, the difference between PLA and non-PLA samples was only observed with c-rmpA. Δwzi, Δwzy-K1, and ΔwziΔwzy-K1 strains reverted to hypovirulence. In the Kupffer cell stimulation assay, interleukin (IL)-6, IL-12, IL-10, and transforming growth factor-β secretions were found to be equivalent in NTUH-K2044, Δwzi, Δwzy-K1, and ΔwziΔwzy-K1 groups. Lower IL-1β and higher tumor necrosis factor-α secretions were observed for Δwzi, Δwzy-K1, and ΔwziΔwzy-K1.ConclusionsHypercapsule production is the cornerstone of hypervirulence, regardless of exopolysaccharides. K1 K. pneumoniae-induced PLA may decrease core inflammatory cytokines rather than increase anti-inflammatory cytokines. Exopolysaccharides could also attenuate the inflammatory response to aid in the immune escape of K. pneumoniae.
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Affiliation(s)
- Dakang Hu
- Department of Laboratory Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Wenjie Chen
- Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Weiwen Wang
- Department of Laboratory Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Dongxing Tian
- Department of Laboratory Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Pan Fu
- Department of Laboratory Medicine, Huashan Hospital, Fudan University, Shanghai, China
- Microbiology Department, Children’s Hospital of Fudan University, Shanghai, China
| | - Ping Ren
- Zhejiang Provincial Demonstration Centre of Laboratory Medicine Experimental Teaching, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Qing Mu
- School of Pharmacy, Fudan University, Shanghai, China
| | - Gang Li
- Department of Laboratory Medicine, Jinshan Hospital of Fudan University, Shanghai, China
- *Correspondence: Gang Li, ; Xiaofei Jiang,
| | - Xiaofei Jiang
- Department of Laboratory Medicine, Huashan Hospital, Fudan University, Shanghai, China
- *Correspondence: Gang Li, ; Xiaofei Jiang,
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Fleeman RM, Mikesh M, Davies BW. Investigating Klebsiella pneumoniae biofilm preservation for scanning electron microscopy. Access Microbiol 2023; 5:000470.v3. [PMID: 36910511 PMCID: PMC9996182 DOI: 10.1099/acmi.0.000470.v3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 01/02/2023] [Indexed: 02/05/2023] Open
Abstract
Klebsiella pneumoniae biofilm formation is associated with chronic and relapsing infections. Scanning electron microscopy (SEM) is a powerful tool for characterizing biofilm structure and studying their formation. Reliable visualization of biofilm structure requires careful sample preservation, otherwise there may be loss of non-covalent interactions that are susceptible to damage during the dehydration and washing preparation steps. However, no standard procedure has been adopted in the literature to fix K. pneumoniae biofilm for scanning electron microscopy studies. This lack of standardization makes it challenging to compare results between studies and determine the degree to which native structures have been preserved. To advance this critical area of study, we investigated different scanning electron microscopy fixation methods for K. pneumoniae biofilm preservation. Our study reveals the impact preparation steps can have on retaining in biofilm architecture observed using scanning electron microscopy. Using fixation methods developed through our studies, we show that although species that overproduce capsular extracellular polysaccharides produced more robust biofilms, K. pneumoniae can form a developed biofilm in the absence of capsular polysaccharides.
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Affiliation(s)
- Renee M. Fleeman
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
- Present address: Division of Immunity and Pathogenesis, Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, FL 32837, USA
| | - Michelle Mikesh
- Center for Biomedical Research Support, The University of Texas at Austin, Austin, TX 78712, USA
| | - Bryan W. Davies
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA
- Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX 78712, USA
- John Ring LaMontagne Center for Infectious Diseases, The University of Texas at Austin, Austin, TX 78712, USA
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Horng YT, Dewi Panjaitan NS, Chang HJ, Wei YH, Chien CC, Yang HC, Chang HY, Soo PC. A protein containing the DUF1471 domain regulates biofilm formation and capsule production in Klebsiella pneumoniae. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2022; 55:1246-1254. [PMID: 34924339 DOI: 10.1016/j.jmii.2021.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 11/08/2021] [Accepted: 11/20/2021] [Indexed: 12/27/2022]
Abstract
BACKGROUND/PURPOSE Biofilms formed by Klebsiella pneumoniae on medical devices increase infection risk. Fimbriae and capsule polysaccharides (CPSs) are important factors involved in biofilm formation. KP1_4563 in K. pneumoniae NTUH-K2044, a small protein containing the DUF1471 domain, was reported to inhibit type 3 fimbriae function. In this study, we aimed to determine whether the KP1_4563 homolog is conserved in each K. pneumoniae isolate and what role it has in Klebsiella biofilms. METHODS The genomes of K. pneumoniae NTUH-K2044, CG43, MGH78578, KPPR1 and STU1 were compared. The KP1_4563 homolog in K. pneumoniae STU1 was named orfX. Biofilms of wild-type and orfX mutant strains from K. pneumoniae STU1 and one clinical isolate, 83535, were quantified. Transcription levels of the type 3 fimbrial genes, mrkA and mrkH, were investigated by RT-qPCR. MrkA of the wild-type and orfX mutant were observed by Western blotting. The morphology of bacterial cells was observed by transmission electron microscopy (TEM). Bacterial CPSs were quantified. RESULTS The gene and upstream region of orfX were conserved among the five K. pneumoniae isolates. Deletion of orfX enhanced Klebsiella biofilm formation. However, the amount of mRNA from mrkA and mrkH and the level of MrkA protein were not different between the wild type and orfX mutant. In contrast, the amount of CPS in orfX mutants was increased, compared to their parental strains, STU1 and 83535. CONCLUSION The role of orfX is speculated to be conserved in most K. pneumoniae isolates. OrfX negatively controlled biofilm formation by reducing CPS, not type 3 fimbriae, production.
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Affiliation(s)
- Yu-Tze Horng
- Department of Laboratory Medicine and Biotechnology, College of Medicine, Tzu Chi University, Hualien, Taiwan, R.O.C
| | - Novaria Sari Dewi Panjaitan
- Department of Laboratory Medicine and Biotechnology, College of Medicine, Tzu Chi University, Hualien, Taiwan, R.O.C
| | - Hui-Ju Chang
- Department of Laboratory Medicine and Biotechnology, College of Medicine, Tzu Chi University, Hualien, Taiwan, R.O.C
| | - Yu-Hong Wei
- Graduate School of Biotechnology and Bioengineering, Yuan Ze University, Taoyuan, Taiwan, R.O.C
| | - Chih-Ching Chien
- Graduate School of Biotechnology and Bioengineering, Yuan Ze University, Taoyuan, Taiwan, R.O.C
| | - Hung-Chi Yang
- Department of Medical Laboratory Science and Biotechnology, Yuanpei University of Medical Technology, Hsinchu, Taiwan, R.O.C
| | - Heng-Yuan Chang
- School of Post-Baccalaureate Chinese Medicine, College of Medicine, Tzu Chi University, Hualien, Taiwan, R.O.C
| | - Po-Chi Soo
- Department of Laboratory Medicine and Biotechnology, College of Medicine, Tzu Chi University, Hualien, Taiwan, R.O.C.
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Ma J, Song X, Li M, Yu Z, Cheng W, Yu Z, Zhang W, Zhang Y, Shen A, Sun H, Li L. Global Spread of Carbapenem-Resistant Enterobacteriaceae: Epidemiological Features, Resistance Mechanisms, Detection and Therapy. Microbiol Res 2022; 266:127249. [DOI: 10.1016/j.micres.2022.127249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 10/25/2022] [Accepted: 10/28/2022] [Indexed: 11/06/2022]
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Identification of the BolA Protein Reveals a Novel Virulence Factor in K. pneumoniae That Contributes to Survival in Host. Microbiol Spectr 2022; 10:e0037822. [PMID: 36121239 PMCID: PMC9603091 DOI: 10.1128/spectrum.00378-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BolA has been characterized as an important transcriptional regulator, which is induced in the stationary phase of growth and is often associated with bacterial virulence. This study was initiated to elucidate the role of the BolA in the virulence of K. pneumoniae. Using a mouse infection model, we revealed bolA mutant strain yielded significantly decreased bacterial loads in the liver, spleen, lung, and kidney, and failed to form liver abscesses. Gene deletion demonstrated that the bolA was required for siderophore production, biofilm formation, and adhesion to human colon cancer epithelial cells HCT116. Quantitative reverse transcriptase PCR (RT-qPCR) indicated that BolA could impact the expression of pulK, pulF, pulE, clpV, vgrG, entE, relA, and spoT genes on a genome-wide scale, which are related to type II secretion system (T2SS), type VI secretion system (T6SS), guanosine tetraphosphate (ppGpp), and siderophore synthesis and contribute to fitness in the host. Furthermore, the metabolome analysis showed that the deletion of the bolA gene led to decreased pools of five metabolites: biotin, spermine, cadaverine, guanosine, and flavin adenine dinucleotide, all of which are involved in pathways related to virulence and stress resistance. Taken together, we provided evidence that BolA was a significant virulence factor in the ability of K. pneumoniae to survive, and this was an important step in progress to an understanding of the pathways underlying bacterial virulence. IMPORTANCE BolA has been characterized as an important transcriptional regulator, which is induced in the stationary phase of growth and affects different pathways directly associated with bacterial virulence. Here, we unraveled the role of BolA in several phenotypes associated with the process of cell morphology, siderophore production, biofilm formation, cell adhesion, tissue colonization, and liver abscess. We also uncovered the importance of BolA for the success of K. pneumoniae infection and provided new clues to the pathogenesis strategies of this organism. This work constitutes a relevant step toward an understanding of the role of BolA protein as a master regulator and virulence factor. Therefore, this study is of great importance for understanding the pathways underlying K. pneumoniae virulence and may contribute to public health care applications.
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Jin Z, Wang Z, Gong L, Yi L, Liu N, Luo L, Gong W. Molecular epidemiological characteristics of carbapenem-resistant Klebsiella pneumoniae among children in China. AMB Express 2022; 12:89. [PMID: 35829853 PMCID: PMC9279541 DOI: 10.1186/s13568-022-01437-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Accepted: 07/06/2022] [Indexed: 11/10/2022] Open
Abstract
Klebsiella pneumoniae infection and antimicrobial resistance among children are major concerns. The occurrence of hypervirulent K. pneumoniae (hvKp) infections is gradually increasing worldwide, and disinfectant resistance is also being reported. Carbapenem- and disinfectant-resistant hvKp infection has made clinical treatment and nosocomial infection control among children increasingly challenging. In this study, whole-genome sequencing was conducted among 34 Carba NP-positive carbapenem-resistant K. pneumoniae (CRKP) strains, and the distribution of antibiotic resistance genes, virulence genes and disinfectant resistance genes was determined. Eleven distinct STs were identified, and most of them were ST11 (58.8%). Among the carbapenem resistance genes, KPC-2 was predominant (61.8%), followed by NDM-1 (26.5%) and IPM-4 (11.8%), and no other carbapenemase genes were found. Twelve virulence genes were investigated. All 34 CRKP strains carried the following virulence genes: rcsA/B, entA, fimA/H and mrkA/D. The gene iucB was present in only 3 (8.9%) CRKP strains. The positive detection rates of the iroN and ybtA genes were 94.1% and 64.7%, respectively. None of the strains was found to carry the rmpA and iroB genes. Two disinfectant resistance genes were investigated in this study. Twenty-one (61.8%) strains carried both the qacE and cepA disinfectant resistance genes, 13 (38.2%) CRKP strains carried only the cepA gene, and no strains with only the qacE gene was detected. The correlations among virulence, drug resistance and disinfectant tolerance showed that the virulence and disinfectant resistance genes were distinct among several types of carbapenemase-producing CRKP strains.
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Affiliation(s)
- Zhengjiang Jin
- Department of Clinical Laboratory, Maternal and Child Health Hospital of Hubei Province, Wuhan, 430070, China
| | - Zhenhui Wang
- Department of Clinical Laboratory, Maternal and Child Health Hospital of Hubei Province, Wuhan, 430070, China
| | - Lin Gong
- Department of Disinfection and Pest Control, Wuhan Center for Disease Control & Prevention, Wuhan, 430000, China
| | - Lu Yi
- Department of Clinical Laboratory, Maternal and Child Health Hospital of Hubei Province, Wuhan, 430070, China
| | - Nian Liu
- Department of Clinical Laboratory, Maternal and Child Health Hospital of Hubei Province, Wuhan, 430070, China
| | - Lan Luo
- Department of Child Health, Maternal and Child Health Hospital of Hubei Province, Wuhan, 430070, China.
| | - Wenting Gong
- Department of Pharmacy, Maternal and Child Health Hospital of Hubei Province, Wuhan, 430070, China
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Targeting the Holy Triangle of Quorum Sensing, Biofilm Formation, and Antibiotic Resistance in Pathogenic Bacteria. Microorganisms 2022; 10:microorganisms10061239. [PMID: 35744757 PMCID: PMC9228545 DOI: 10.3390/microorganisms10061239] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 06/12/2022] [Accepted: 06/14/2022] [Indexed: 12/12/2022] Open
Abstract
Chronic and recurrent bacterial infections are frequently associated with the formation of biofilms on biotic or abiotic materials that are composed of mono- or multi-species cultures of bacteria/fungi embedded in an extracellular matrix produced by the microorganisms. Biofilm formation is, among others, regulated by quorum sensing (QS) which is an interbacterial communication system usually composed of two-component systems (TCSs) of secreted autoinducer compounds that activate signal transduction pathways through interaction with their respective receptors. Embedded in the biofilms, the bacteria are protected from environmental stress stimuli, and they often show reduced responses to antibiotics, making it difficult to eradicate the bacterial infection. Besides reduced penetration of antibiotics through the intricate structure of the biofilms, the sessile biofilm-embedded bacteria show reduced metabolic activity making them intrinsically less sensitive to antibiotics. Moreover, they frequently express elevated levels of efflux pumps that extrude antibiotics, thereby reducing their intracellular levels. Some efflux pumps are involved in the secretion of QS compounds and biofilm-related materials, besides being important for removing toxic substances from the bacteria. Some efflux pump inhibitors (EPIs) have been shown to both prevent biofilm formation and sensitize the bacteria to antibiotics, suggesting a relationship between these processes. Additionally, QS inhibitors or quenchers may affect antibiotic susceptibility. Thus, targeting elements that regulate QS and biofilm formation might be a promising approach to combat antibiotic-resistant biofilm-related bacterial infections.
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Hu D, Chen W, Zhang Q, Li M, Yang Z, Wang Y, Huang Y, Li G, Tian D, Fu P, Wang W, Ren P, Mu Q, Yu L, Jiang X. Prevalence of Carbapenem-Resistant Hypervirulent Klebsiella pneumoniae and Hypervirulent Carbapenem-Resistant Klebsiella pneumoniae in China Determined via Mouse Lethality Tests. Front Cell Infect Microbiol 2022; 12:882210. [PMID: 35719357 PMCID: PMC9199425 DOI: 10.3389/fcimb.2022.882210] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 04/20/2022] [Indexed: 02/01/2023] Open
Abstract
Objective To investigate the epidemiology of carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-HvKP) and hypervirulent carbapenem-resistant Klebsiella pneumoniae (Hv-CRKP). Methods Totally 436 K. pneumoniae strains were collected from 7 hospitals in mainland China between 2017.01 and 2018.02. Sequence types, serotypes, antimicrobial-resistance and virulence genes were analyzed. Additionally, string test, capsule stain, Periodic Acid Schiff stain, fitness analysis, quantitative real-time PCR and mouse lethality test were also performed. Molecular combinations were used to screen putative blaKPC(+)-HvKP and Hv-blaKPC(+)-KP, followed by the confirmation of mouse lethality test. Results Diverse detection rates were found for the virulence genes, ranging from c-rmpA (0.0%) to entB (100.0%). According to the molecular criteria, 127, 186, 9 and 26 strains were putatively denoted as HvKP, blaKPC(+)-KP, blaKPC(+)-HvKP and Hv-blaKPC(+)-KP. Mouse lethality test confirmed 2 blaKPC(+)-HvKP strains (JS184 and TZ20) and no Hv-blaKPC(+)-KP. JS184 showed K2 serotype, thin capsule, positive exopolysaccharid and string test. TZ20 presented K20 serotype, thin capsule, negative exopolysaccharide and string test. Compared with the positive control NTUH-K2044, equal galF expression and growth curves were confirmed for JS184 and TZ20. Conclusions Molecular determination of CR-HvKP and Hv-CRKP brings remarkable bias compared with mouse lethality test. The exact prevalence of CR-HvKP is less than 1.0%, which of Hv-CRKP is much lower.
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Affiliation(s)
- Dakang Hu
- Department of Laboratory Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Wenjie Chen
- Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Qi Zhang
- Department of Laboratory Medicine, Henan Provincial People’s Hospital & the People’s Hospital of Zhengzhou University, Zhengzhou, China
| | - Meng Li
- Department of Clinical Laboratory, The First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Zehua Yang
- Department of Laboratory Medicine, Sixth Hospital of Shanxi Medical University, Taiyuan, China
| | - Yong Wang
- Department of Clinical Laboratory, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China
| | - Yunkun Huang
- Department of Laboratory Medicine, Kunming Yan’an Hospital, Kunming, China
| | - Gang Li
- Department of Laboratory Medicine, Jinshan Hospital of Fudan University, Shanghai, China
| | - Dongxing Tian
- Department of Laboratory Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Pan Fu
- Department of Laboratory Medicine, Huashan Hospital, Fudan University, Shanghai, China
- Microbiology Department. Children’s Hospital of Fudan University, Shanghai, China
| | - Weiwen Wang
- Department of Laboratory Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Ping Ren
- Zhejiang Provincial Demonstration Centre of Laboratory Medicine Experimental Teaching, Wenzhou Medical University, Wenzhou, China
| | - Qing Mu
- School of Pharmacy, Fudan University, Shanghai, China
| | - Lianhua Yu
- Department of Laboratory Medicine, Taizhou Municipal Hospital, Taizhou, China
- *Correspondence: Xiaofei Jiang, ; Lianhua Yu,
| | - Xiaofei Jiang
- Department of Laboratory Medicine, Huashan Hospital, Fudan University, Shanghai, China
- *Correspondence: Xiaofei Jiang, ; Lianhua Yu,
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13
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Shen L, Zhang J, Xue J, Du L, Yuan L, Nie H, Dai S, Yu Q, Li Y. Regulation of ECP fimbriae-related genes by the transcriptional regulator RcsAB in Klebsiella pneumoniae NTUH-K2044. J Basic Microbiol 2022; 62:593-603. [PMID: 35132658 DOI: 10.1002/jobm.202100595] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 01/06/2022] [Accepted: 01/15/2022] [Indexed: 11/11/2022]
Abstract
Klebsiella pneumoniae is one of the major pathogens causing nosocomial infections. The regulator of capsule synthesis (Rcs) system is a complex signal transduction pathway that is involved in the regulation of virulence factors of K. pneumoniae as an important transcriptional regulator. The RcsAB box-like sequence was found to be present in the promoter-proximal regions of ykgK, one of the ECP fimbriae-related genes, which suggested the expression of ECP fimbriae may be regulated by RcsAB. The ykgK gene in K. pneumoniae has 86% similarity to the ecpR gene in Escherichia coli. Nucleotide sequence alignment revealed a similar ECP fimbriae gene cluster including six genes in K. pneumoniae, which was proved to be on the same operon in this study. The electrophoretic mobility shift assay and DNase I assay, relative fluorescence expression, β-galactosidase activity, and relative gene expression of ykgK in the wild-type and mutant strains were performed to determine the transcriptional regulation mechanism of RcsAB on ECP fimbriae. The mutant ΔykgK and complementary strain ΔykgK/cΔykgK were constructed to complete the Galleria mellonella larvae infection experiment and biofilm formation assay. This study showed that RcsAB binds directly to the promoter region of the ykgK gene to positively regulate ECP fimbriae-related gene clusters, and then positively affect the biofilm formation.
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Affiliation(s)
- Lifei Shen
- School of Public Health and Management, Chongqing Medical University, Chongqing, China
| | - Jiaxue Zhang
- Chongqing Jiangbei District Center for Disease Control and Prevention, Chongqing, China
| | - Jian Xue
- Zunyi Medical and Pharmaceutical College, Zunyi, China
| | - Ling Du
- School of Public Health and Management, Chongqing Medical University, Chongqing, China
| | - Lingyue Yuan
- School of Public Health and Management, Chongqing Medical University, Chongqing, China
| | - Hao Nie
- School of Public Health and Management, Chongqing Medical University, Chongqing, China
| | - Sue Dai
- School of Public Health and Management, Chongqing Medical University, Chongqing, China
| | - Qian Yu
- School of Public Health and Management, Chongqing Medical University, Chongqing, China
| | - Yingli Li
- School of Public Health and Management, Chongqing Medical University, Chongqing, China
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14
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Xiong L, Su L, Tan H, Zhao W, Li S, Zhu Y, Lu L, Huang Z, Li B. Molecular Epidemiological Analysis of ST11-K64 Extensively Drug-Resistant Klebsiella pneumoniae Infections Outbreak in Intensive Care and Neurosurgery Units Based on Whole-Genome Sequencing. Front Microbiol 2021; 12:709356. [PMID: 34646245 PMCID: PMC8504482 DOI: 10.3389/fmicb.2021.709356] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 08/18/2021] [Indexed: 11/13/2022] Open
Abstract
Klebsiella pneumoniae (Kp) is the primary causative bacteria for nosocomial infections and hospital outbreaks. In particular, extensively drug-resistant K. pneumoniae (XDRKp) causes severe clinical infections in hospitalized patients. Here, we used pulsed-field gel electrophoresis (PFGE), drug susceptibility tests, and the whole-genome sequencing (WGS) technology to examine genetic relatedness and phenotypic traits of the strains isolated during an outbreak period. Based on PFGE, a distinct clones cluster comprised of eight XDRKp was observed. These strains were confirmed as ST11-K64 via multiple-locus sequence typing database of Kp. The strains also had genes related to the regulation of biofilm biosynthesis (type 1 & 3 fimbriae, type IV pili biosynthesis, RcsAB, and type VI secretion system) and multiple drug resistance (β-lactamase and aminoglycoside antibiotic resistance). WGS data based on core-single nucleotide polymorphisms and epidemiological investigation showed that the neurosurgery unit was likely the source of the outbreak, the strain was likely to have been transmitted to the ICU through patients. In addition, the two highly probable transmission routes were in the ICU (exposure through shared hospital beds) and the neurosurgery units (all cases were treated by the same rehabilitation physician and were most likely infected during the physical therapy). Notably, the bed mattress had played a crucial transmission role of this outbreak, served as a pathogen reservoir.
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Affiliation(s)
- Liuxin Xiong
- Clinical Laboratory, The Second People's Hospital of Zhaoqing, Zhaoqing, China
| | - Lebin Su
- Microbiological Laboratory, Zhaoqing Center for Disease Control and Prevention, Zhaoqing, China
| | - Hanqing Tan
- Microbiological Laboratory, Zhaoqing Center for Disease Control and Prevention, Zhaoqing, China
| | - Wansha Zhao
- Microbiological Laboratory, Zhaoqing Center for Disease Control and Prevention, Zhaoqing, China
| | - Shuying Li
- Clinical Laboratory, The Second People's Hospital of Zhaoqing, Zhaoqing, China
| | - Yingmei Zhu
- Microbiological Laboratory, Zhaoqing Center for Disease Control and Prevention, Zhaoqing, China
| | - Limiao Lu
- Clinical Laboratory, The Second People's Hospital of Zhaoqing, Zhaoqing, China
| | - Zhiwei Huang
- Clinical Laboratory, The Second People's Hospital of Zhaoqing, Zhaoqing, China
| | - Baisheng Li
- Institute of Microbiology, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, China
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15
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Lazar V, Holban AM, Curutiu C, Chifiriuc MC. Modulation of Quorum Sensing and Biofilms in Less Investigated Gram-Negative ESKAPE Pathogens. Front Microbiol 2021; 12:676510. [PMID: 34394026 PMCID: PMC8359898 DOI: 10.3389/fmicb.2021.676510] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 06/30/2021] [Indexed: 01/20/2023] Open
Abstract
Pathogenic bacteria have the ability to sense their versatile environment and adapt by behavioral changes both to the external reservoirs and the infected host, which, in response to microbial colonization, mobilizes equally sophisticated anti-infectious strategies. One of the most important adaptive processes is the ability of pathogenic bacteria to turn from the free, floating, or planktonic state to the adherent one and to develop biofilms on alive and inert substrata; this social lifestyle, based on very complex communication networks, namely, the quorum sensing (QS) and response system, confers them an increased phenotypic or behavioral resistance to different stress factors, including host defense mechanisms and antibiotics. As a consequence, biofilm infections can be difficult to diagnose and treat, requiring complex multidrug therapeutic regimens, which often fail to resolve the infection. One of the most promising avenues for discovering novel and efficient antibiofilm strategies is targeting individual cells and their QS mechanisms. A huge amount of data related to the inhibition of QS and biofilm formation in pathogenic bacteria have been obtained using the well-established gram-positive Staphylococcus aureus and gram-negative Pseudomonas aeruginosa models. The purpose of this paper was to revise the progress on the development of antibiofilm and anti-QS strategies in the less investigated gram-negative ESKAPE pathogens Klebsiella pneumoniae, Acinetobacter baumannii, and Enterobacter sp. and identify promising leads for the therapeutic management of these clinically significant and highly resistant opportunistic pathogens.
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Affiliation(s)
- Veronica Lazar
- Department of Microbiology and Immunology, Faculty of Biology, University of Bucharest, Bucharest, Romania
- The Research Institute of the University of Bucharest, Bucharest, Romania
| | - Alina Maria Holban
- Department of Microbiology and Immunology, Faculty of Biology, University of Bucharest, Bucharest, Romania
- The Research Institute of the University of Bucharest, Bucharest, Romania
| | - Carmen Curutiu
- Department of Microbiology and Immunology, Faculty of Biology, University of Bucharest, Bucharest, Romania
- The Research Institute of the University of Bucharest, Bucharest, Romania
| | - Mariana Carmen Chifiriuc
- Department of Microbiology and Immunology, Faculty of Biology, University of Bucharest, Bucharest, Romania
- The Research Institute of the University of Bucharest, Bucharest, Romania
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16
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Zhang M, Li J, Lu Y, Wu W, Wu J, Xu Y, Zhong Y, Liu S, Lin C, Xu S, Chen D, Gao X, Luo Y, Chen H, Liu X, Huang W. Expanding of ST11 Carbapenemase-Producing Klebsiella pneumoniae Subclones in a Chinese Hospital, Shenzhen, China. Infect Drug Resist 2021; 14:1415-1422. [PMID: 33880046 PMCID: PMC8053513 DOI: 10.2147/idr.s299478] [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: 01/03/2021] [Accepted: 03/21/2021] [Indexed: 12/12/2022] Open
Abstract
Background ST11 is the most prevalent sequence type of clinical Klebsiella pneumoniae in China. Methods We investigated the characteristics of the ST11 subclones using core genome multi-locus sequence typing (cgMLST). Ninety-three carbapenemase-producing K. pneumoniae isolates were collected at Shenzhen People's Hospital. Then, whole-genome sequencing and cgMLST were used to discriminate apparent subclones within the ST11 group. Results We analyzed the prevalence and genetic relationships of these subclones. ST11 and K. pneumoniae carbapenemase (KPC-2) were the predominant genotype and carbapenemase, respectively, in the clinical carbapenemase-producing K. pneumoniae strains. cgMLST scheme genotyping divided the ST11 group into two clades across seven complex types (CTs). CT1313 was the most prevalent subclone. The deletion of galF and a high frequency of SNPs in genes associated with the stress- and SOS-responses were found in CT1291 and CT2405 over time, respectively. Conclusion Our results indicated that the subclones of the ST11 group had different patterns of prevalence. Highly discriminatory genotyping techniques, such as cgMLST scheme, should be used in further molecular epidemiology investigations.
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Affiliation(s)
- Min Zhang
- Shenzhen People's Hospital, Shenzhen Institute of Respiratory Diseases, Shenzhen, Guangdong, People's Republic of China.,Bacteriology & Antibacterial Resistance Surveillance Laboratory, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, Guangdong, People's Republic of China
| | - Jia Li
- Department of Nosocomial Infection Control, Bengbu Third People's Hospital, Bengbu, People's Republic of China
| | - Yuemei Lu
- Department of Clinical Microbiology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, Guangdong, People's Republic of China
| | - Weiyuan Wu
- Department of Clinical Microbiology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, Guangdong, People's Republic of China
| | - Jinsong Wu
- Department of Clinical Microbiology, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, Guangdong, People's Republic of China
| | - Yanji Xu
- Shenzhen People's Hospital, Shenzhen Institute of Respiratory Diseases, Shenzhen, Guangdong, People's Republic of China.,Nanshan District Center of Chronic Disease Control, Shenzhen, People's Republic of China
| | - Yuxin Zhong
- Shenzhen People's Hospital, Shenzhen Institute of Respiratory Diseases, Shenzhen, Guangdong, People's Republic of China.,Bacteriology & Antibacterial Resistance Surveillance Laboratory, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, Guangdong, People's Republic of China
| | - Shiyi Liu
- Shenzhen People's Hospital, Shenzhen Institute of Respiratory Diseases, Shenzhen, Guangdong, People's Republic of China.,Bacteriology & Antibacterial Resistance Surveillance Laboratory, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, Guangdong, People's Republic of China
| | - Chuchu Lin
- Department of Nosocomial Infection Control, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, Guangdong, People's Republic of China
| | - Shuye Xu
- Department of Nosocomial Infection Control, Bengbu Third People's Hospital, Bengbu, People's Republic of China
| | - Dandan Chen
- Shenzhen People's Hospital, Shenzhen Institute of Respiratory Diseases, Shenzhen, Guangdong, People's Republic of China.,Bacteriology & Antibacterial Resistance Surveillance Laboratory, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, Guangdong, People's Republic of China
| | - Xuefeng Gao
- Department of Gastroenterology and Hepatology, Shenzhen University General Hospital, Shenzhen, People's Republic of China
| | - Yutian Luo
- Department of Intensive Care Unit, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, Guangdong, People's Republic of China
| | - Huaisheng Chen
- Department of Intensive Care Unit, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, Guangdong, People's Republic of China
| | - Xueyan Liu
- Department of Intensive Care Unit, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, Guangdong, People's Republic of China
| | - Wei Huang
- Shenzhen People's Hospital, Shenzhen Institute of Respiratory Diseases, Shenzhen, Guangdong, People's Republic of China.,Bacteriology & Antibacterial Resistance Surveillance Laboratory, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University; The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, Guangdong, People's Republic of China
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17
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Genome sequencing and comparative genome analysis of 6 hypervirulent Klebsiella pneumoniae strains isolated in China. Arch Microbiol 2021; 203:3125-3133. [PMID: 33811489 PMCID: PMC8019302 DOI: 10.1007/s00203-021-02263-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 02/17/2021] [Accepted: 02/24/2021] [Indexed: 11/23/2022]
Abstract
Hypervirulent Klebsiella pneumoniae (hvKP) has been increasingly reported over the past three decades and causes severe infections. To increase our understanding of hvKP at the genome level, genome sequencing and comparative genome analysis were performed on 6 hvKPs. The whole genome DNA from 6 hvKPs with different capsular serotypes isolated in China was extracted. The genome sequencing and assembly results showed the genome size of the six hvKPs and GC content. Comparative analyses of the genomes revealed the gene homology and genome rearrangement in the 6 hvKPs compared with Klebsiella pneumonia NTUH-K2044. The phylogenetic tree based on full-genome SNPs of the 7 hvKPs showed that NTUH-K2044 formed a single clade, showing distant evolutionary distances with the other six strains, and the non-K1 hvKP strains had a relatively closer phylogenetic relationship. BLAST comparison analysis found that some selected virulence genes had different degrees of deletion in the non-K1 hvKPs. SNP-based virulence gene mutation analysis showed that some virulence genes had different degrees of SNP mutations. The whole-genome sequencing and comparative genome analysis of six hvKP strains with NTUH-K2044 provide us with a basic understanding of the genome composition, genetic polymorphism, evolution and virulence genes of hvKP and a basis for further research on these genes and the pathogenesis of hvKP.
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18
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Gomes AÉI, Pacheco T, Dos Santos CDS, Pereira JA, Ribeiro ML, Darrieux M, Ferraz LFC. Functional Insights From KpfR, a New Transcriptional Regulator of Fimbrial Expression That Is Crucial for Klebsiella pneumoniae Pathogenicity. Front Microbiol 2021; 11:601921. [PMID: 33552015 PMCID: PMC7861041 DOI: 10.3389/fmicb.2020.601921] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 12/03/2020] [Indexed: 12/17/2022] Open
Abstract
Although originally known as an opportunistic pathogen, Klebsiella pneumoniae has been considered a worldwide health threat nowadays due to the emergence of hypervirulent and antibiotic-resistant strains capable of causing severe infections not only on immunocompromised patients but also on healthy individuals. Fimbriae is an essential virulence factor for K. pneumoniae, especially in urinary tract infections (UTIs), because it allows the pathogen to adhere and invade urothelial cells and to form biofilms on biotic and abiotic surfaces. The importance of fimbriae for K. pneumoniae pathogenicity is highlighted by the large number of fimbrial gene clusters on the bacterium genome, which requires a coordinated and finely adjusted system to control the synthesis of these structures. In this work, we describe KpfR as a new transcriptional repressor of fimbrial expression in K. pneumoniae and discuss its role in the bacterium pathogenicity. K. pneumoniae with disrupted kpfR gene exhibited a hyperfimbriated phenotype with enhanced biofilm formation and greater adhesion to and replication within epithelial host cells. Nonetheless, the mutant strain was attenuated for colonization of the bladder in a murine model of urinary tract infection. These results indicate that KpfR is an important transcriptional repressor that, by negatively controlling the expression of fimbriae, prevents K. pneumoniae from having a hyperfimbriated phenotype and from being recognized and eliminated by the host immune system.
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Affiliation(s)
- Ana Érika Inácio Gomes
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Thaisy Pacheco
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | | | - José Aires Pereira
- Laboratório de Biologia Molecular e Celular de Tumores, Universidade São Francisco, Bragança Paulista, Brazil
| | - Marcelo Lima Ribeiro
- Laboratório de Imunofarmacologia e Biologia Molecular, Universidade São Francisco, Bragança Paulista, Brazil
| | - Michelle Darrieux
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
| | - Lúcio Fábio Caldas Ferraz
- Laboratório de Biologia Molecular de Microrganismos, Universidade São Francisco, Bragança Paulista, Brazil
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19
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Yuan L, Li X, Du L, Su K, Zhang J, Liu P, He Q, Zhang Z, Peng D, Shen L, Qiu J, Li Y. RcsAB and Fur Coregulate the Iron-Acquisition System via entC in Klebsiella pneumoniae NTUH-K2044 in Response to Iron Availability. Front Cell Infect Microbiol 2020; 10:282. [PMID: 32587833 PMCID: PMC7298118 DOI: 10.3389/fcimb.2020.00282] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 05/12/2020] [Indexed: 01/21/2023] Open
Abstract
The iron acquisition system is an essential virulence factor for human infection and is under tight regulatory control in a variety of pathogens. Ferric-uptake regulator (Fur) is one of Fe2+-responsive transcription factor that maintains iron homeostasis, and the regulator of capsule synthesis (Rcs) is known to regulate exopolysaccharide biosynthesis. We speculate the Rcs may involve in iron-acquisition given the identified regulator box in the upstream of entC that participated in the biosynthesis of enterobactin. To study the coregulation by RcsAB and Fur of entC, we measured the β-galactosidase activity and relative mRNA expression of entC in WT and mutant strains. The RcsAB- and Fur-protected regions were identified by an electrophoretic mobility shift assay (EMSA) and a DNase I footprinting assay. A regulatory cascade was identified with which Fur repressed rcsA expression and reduced RcsAB and entC expression. Our study demonstrated that entC was coregulated by two different transcriptional regulators, namely, RcsAB and Fur, in response to iron availability in Klebsiella pneumoniae.
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Affiliation(s)
- Lingyue Yuan
- School of Public Health and Management, Chongqing Medical University, Chongqing, China
| | - Xuan Li
- School of Public Health and Management, Chongqing Medical University, Chongqing, China
| | - Ling Du
- School of Public Health and Management, Chongqing Medical University, Chongqing, China
| | - Kewen Su
- Hangzhou Hospital for the Prevention and Treatment of Occupational Disease, Hangzhou, China
| | - Jiaxue Zhang
- School of Public Health and Management, Chongqing Medical University, Chongqing, China
| | - Pin Liu
- Nanjing Center for Disease Control and Prevention, Nanjing, China
| | - Qiang He
- School of Public Health and Management, Chongqing Medical University, Chongqing, China
| | - Zhongshuang Zhang
- School of Public Health and Management, Chongqing Medical University, Chongqing, China
| | - Dan Peng
- School of Public Health and Management, Chongqing Medical University, Chongqing, China
| | - Lifei Shen
- School of Public Health and Management, Chongqing Medical University, Chongqing, China
| | - Jingfu Qiu
- School of Public Health and Management, Chongqing Medical University, Chongqing, China
| | - Yingli Li
- School of Public Health and Management, Chongqing Medical University, Chongqing, China
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20
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Liu W, Lu H, Chu X, Lou T, Zhang N, Zhang B, Chu W. Tea polyphenols inhibits biofilm formation, attenuates the quorum sensing-controlled virulence and enhances resistance to Klebsiella pneumoniae infection in Caenorhabditis elegans model. Microb Pathog 2020; 147:104266. [PMID: 32442664 DOI: 10.1016/j.micpath.2020.104266] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 05/13/2020] [Accepted: 05/13/2020] [Indexed: 02/05/2023]
Abstract
Bacteria cells can communicate with each other via quorum sensing (QS) system. Various physiological characteristics including virulence factors and biofilm formation are controlled by QS. So interrupting the bacterial communication is an alternative strategy instead of antibiotics for control bacterial infection. The aim of this study was to investigate the effects of tea polyphenols (TPs) on quorum sensing and virulence factors of Klebsiella pneumoniae. In vitro study showed that the anti-QS activity of tea polyphenols against Chromobacterium violaceum in violacein production. At sub-MICs, TPs inhibited the motility, reduced protease and exopolysaccharide (EPS) production and also biofilm formation in K. pneumoniae. In addition, in vivo study showed that tea polyphenols at 200 μg/mL and 400 μg/mL increased the survival rate of Caenorhabditis elegans to 73.3% and 82.2% against K. pneumonia infection. Our findings suggest that tea polyphenols can act as an effective QS inhibitor and can serve as a novel anti-virulence agent for the management of bacterial pathogens.
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Affiliation(s)
- Wugao Liu
- Lishui People's Hospital, The Sixth Affiliated Hospital of Wenzhou Medical University, Lishui, 323000, China
| | - Hongjia Lu
- School of Life Science and Technology, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 211198, China
| | - Xinyu Chu
- The MacDuffie School, Nanjing Campus, Nanjing, 210002, China
| | - Tianzheng Lou
- Lishui People's Hospital, The Sixth Affiliated Hospital of Wenzhou Medical University, Lishui, 323000, China
| | - Ning Zhang
- Lishui People's Hospital, The Sixth Affiliated Hospital of Wenzhou Medical University, Lishui, 323000, China
| | - Bao Zhang
- School of Life Science and Technology, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 211198, China
| | - Weihua Chu
- School of Life Science and Technology, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 211198, China.
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21
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Walker KA, Miller VL. The intersection of capsule gene expression, hypermucoviscosity and hypervirulence in Klebsiella pneumoniae. Curr Opin Microbiol 2020; 54:95-102. [PMID: 32062153 DOI: 10.1016/j.mib.2020.01.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 01/09/2020] [Indexed: 12/15/2022]
Abstract
For ∼30 years, two distinct groups of clinical isolates of Klebsiella pneumoniae have been recognized. Classical strains (cKp) are typically isolated from patients with some degree of immunocompromise and are not virulent in mouse models of infection whereas hypervirulent strains (hvKp) are associated with community acquired invasive infections and are highly virulent in mouse models of infection. Hyperproduction of capsule and a hypermucoviscous colony phenotype have been strongly associated with the hypervirulence of hvKp strains. Recent studies have begun to elucidate the relationship between capsule gene expression, hypermucoviscosity and hypervirulence. Additionally, genes associated with hyperproduction of capsule and hypermucoviscosity in hvKp strains have been identified in a few cKp isolates. However, it is not clear how the acquisition of these genes impacts the virulence of cKp isolates. A better understanding of the potential risks of these strains is particularly important given that many of them are resistant to multiple antibiotics, including carbapenems.
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Affiliation(s)
- Kimberly A Walker
- Department of Microbiology and Immunology at the University of North Carolina, Chapel Hill, United States
| | - Virginia L Miller
- Department of Microbiology and Immunology at the University of North Carolina, Chapel Hill, United States; Department of Genetics at the University of North Carolina, Chapel Hill, United States.
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22
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Barbosa VAA, Lery LMS. Insights into Klebsiella pneumoniae type VI secretion system transcriptional regulation. BMC Genomics 2019; 20:506. [PMID: 31215404 PMCID: PMC6580597 DOI: 10.1186/s12864-019-5885-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Accepted: 06/05/2019] [Indexed: 12/21/2022] Open
Abstract
Background Klebsiella pneumoniae (KP) is an opportunistic pathogen that mainly causes respiratory and urinary tract infections. The frequent occurrence of simultaneously virulent and multiple drug-resistant isolates led WHO to include this species in the list of top priorities for research and development of therapeutic alternatives. The comprehensive knowledge of the molecular mechanisms underlying KP virulence may lead to the proposal of more efficient and specific drugs. One of its virulence factors is the Type VI Secretion System (T6SS), which contributes to bacterial competition, cell invasion and in vivo colonisation. Despite the few studies showing the involvement of T6SS in KP pathogenesis, little is known concerning the regulation of its expression. The understanding of regulatory mechanisms may give more clues about the function of the system and the possibilities of future interference in this process. This work aimed to standardise the annotation of T6SS genes in KP strains and identify mechanisms of their transcriptional regulation through computational predictions. Results We analyzed the genomes of Kp52.145, HS11286 and NTUH-K2044 strains to perform a broad prediction and re-annotation of T6SS genes through similarity searches, comparative and linear discriminant analysis. 38 genes were found in Kp52.145, while 29 in HS11286 and 30 in NTUH-K2044. Genes coding for iron uptake systems are encoded in adjacencies of T6SS, suggesting that KP T6SS might also play a role in ion import. Some of the T6SS genes are comprised in syntenic regions. 17 sigma 70-dependent promoter regions were identified in Kp52.145, 12 in HS11286 and 12 in NTUH-K2044. Using VirtualFootprint algorithm, binding sites for 13 transcriptional regulators were found in Kp52.145 and 9 in HS11286 and 17 in NTUH-K2044. Six of them are common to the 3 strains: OxyR, H-NS, RcsAB, GcvA, Fis, and OmpR. Conclusions The data presented herein are derived from computational analysis. Although future experimental studies are required to confirm those predictions, they suggest that KP T6SS might be regulated in response to environmental signals that are indeed sensed by the bacteria inside the human host: temperature (H-NS), nutrition-limitation (GcvA and Fis), oxidative stress (OxyR) and osmolarity (RscAB and OmpR). Electronic supplementary material The online version of this article (10.1186/s12864-019-5885-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Victor Augusto Araújo Barbosa
- Cellular Microbiology Laboratory, Oswaldo Cruz Foundation - Oswaldo Cruz Institute, Av. Brasil, 4365 - Manguinhos, Rio de Janeiro, RJ, CEP: 21040-900, Brazil
| | - Leticia Miranda Santos Lery
- Cellular Microbiology Laboratory, Oswaldo Cruz Foundation - Oswaldo Cruz Institute, Av. Brasil, 4365 - Manguinhos, Rio de Janeiro, RJ, CEP: 21040-900, Brazil.
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