scholarly journals Chemical synthesis of the hexasaccharide related to the repeating unit of the capsular polysaccharide from carbapenem resistant Klebsiella pneumoniae 2796 and 3264

RSC Advances ◽  
2016 ◽  
Vol 6 (46) ◽  
pp. 40147-40154 ◽  
Author(s):  
Vikramjit Sarkar ◽  
Balaram Mukhopadhyay
Keyword(s):  
Klebsiella Pneumoniae ◽  
Chemical Synthesis ◽  
Total Synthesis ◽  
Capsular Polysaccharide ◽  
Carbapenem Resistant

Total synthesis of the hexasaccharide repeating unit of the capsular polysaccharide fromKlebsiella pneumoniae2796 and 3264 following a linear sequential glycosylation strategy.

scholarly journals Isolation and characterization of a sequence type 25 carbapenem-resistant hypervirulent Klebsiella pneumoniae from the mid-south region of China

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Jun Li ◽  
Zi-Yan Huang ◽  
Ting Yu ◽  
Xiao-Yan Tao ◽  
Yong-Mei Hu ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Capsular Polysaccharide ◽  
Control Strategies ◽  
Virulence Gene ◽  
Sequence Type ◽  
Pfge Typing ◽  
Main Cluster ◽  
Carbapenem Resistant ◽  
Isolation And Characterization

Abstract Background The molecular characterization of carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) isolates is not well studied. Our goal was to investigate the molecular epidemiology of CR-hvKP strains that were isolated from a Chinese hospital. Results All clinical carbapenem-resistant K. pneumoniae (CR-KP) isolates were collected and identified from patient samples between 2014 and 2017 from a Chinese hospital. The samples were subjected to screening for CR-hvKP by string test and the detection of the aerobactin gene. CR-hvKP isolates were further confirmed through neutrophil phagocytosis and a mice lethality assay. The CR-hvKP isolates were investigated for their capsular genotyping, virulence gene profiles, and the expression of carbapenemase genes by PCR and DNA sequencing. Multilocus sequence type (MLST) and pulsed-field gel electrophoresis (PFGE) were performed to exclude the homology of these isolates. Twenty strains were identified as CR-hvKP. These strains were resistant to imipenem and several other antibiotics, however, most were susceptible to amikacin. Notably, two isolates were not susceptible to tigecycline. Capsular polysaccharide synthesis genotyping revealed that 17 of the 20 CR-hvKP strains belonged to the K2 serotype, while the others belonged to serotypes other than K1, K2, K5, K20, and K57. The strains were found to be positive for 10 types of virulence genes and a variety of these genes coexisted in the same strain. Two carbapenemase genes were identified: blaKPC-2 (13/20) and blaNDM-1 (1/20). PFGE typing revealed eight clusters comprising isolates that belonged to MLST types ST25, ST11 and ST375, respectively. PFGE cluster A was identified as the main cluster, which included 11 isolates that belong to ST25 and mainly from ICU department. Conclusions Our findings suggest that hospital-acquired infections may contribute in part to the CR-hvKP strains identified in this study. It also suggests that ST25 CR-hvKP strain has a clonal distribution in our hospital. Therefore, effective surveillance and strict infection control strategies should be implemented to prevent outbreak by CR-hvKP strains in hospitals setting.

scholarly journals Serum Antibody Responses against Carbapenem-Resistant Klebsiella pneumoniae in Infected Patients

mSphere ◽  
2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Kasturi Banerjee ◽  
Michael P. Motley ◽  
Elizabeth Diago-Navarro ◽  
Bettina C. Fries
Keyword(s):  
Klebsiella Pneumoniae ◽  
Capsular Polysaccharide ◽  
Serum Antibody ◽  
Antibody Responses ◽  
Capsular Polysaccharides ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Reactive Properties

ABSTRACT Capsular polysaccharide (CPS) heterogeneity within carbapenem-resistant Klebsiella pneumoniae (CR-Kp) strain sequence type 258 (ST258) must be considered when developing CPS-based vaccines. Here, we sought to characterize CPS-specific antibody responses elicited by CR-Kp-infected patients. Plasma and bacterial isolates were collected from 33 hospital patients with positive CR-Kp cultures. Isolate capsules were typed by wzi sequencing. Reactivity and measures of efficacy of patient antibodies were studied against 3 prevalent CR-Kp CPS types (wzi29, wzi154, and wzi50). High IgG titers against wzi154 and wzi50 CPS were documented in 79% of infected patients. Patient-derived (PD) IgGs agglutinated CR-Kp and limited growth better than naive IgG and promoted phagocytosis of strains across the serotype isolated from their donors. Additionally, poly-IgG from wzi50 and wzi154 patients promoted phagocytosis of nonconcordant CR-Kp serotypes. Such effects were lost when poly-IgG was depleted of CPS-specific IgG. Additionally, mice infected with wzi50, wzi154, and wzi29 CR-Kp strains preopsonized with wzi50 patient-derived IgG exhibited lower lung CFU than controls. Depletion of wzi50 antibodies (Abs) reversed this effect in wzi50 and wzi154 infections, whereas wzi154 Ab depletion reduced poly-IgG efficacy against wzi29 CR-Kp. We are the first to report cross-reactive properties of CPS-specific Abs from CR-Kp patients through both in vitro and in vivo models. IMPORTANCE Carbapenem-resistant Klebsiella pneumoniae is a rapidly emerging public health threat that can cause fatal infections in up to 50% of affected patients. Due to its resistance to nearly all antimicrobials, development of alternate therapies like antibodies and vaccines is urgently needed. Capsular polysaccharides constitute important targets, as they are crucial for Klebsiella pneumoniae pathogenesis. Capsular polysaccharides are very diverse and, therefore, studying the host’s capsule-type specific antibodies is crucial to develop effective anti-CPS immunotherapies. In this study, we are the first to characterize humoral responses in infected patients against carbapenem-resistant Klebsiella pneumoniae expressing different wzi capsule types. This study is the first to report the efficacy of cross-reactive properties of CPS-specific Abs in both in vitro and in vivo models.

scholarly journals Carbapenem-Resistant Klebsiella pneumoniae Exhibit Variability in Capsular Polysaccharide and Capsule Associated Virulence Traits

2014 ◽  
Vol 210 (5) ◽  
pp. 803-813 ◽  
Author(s):  
Elizabeth Diago-Navarro ◽  
Liang Chen ◽  
Virginie Passet ◽  
Seth Burack ◽  
Amaia Ulacia-Hernando ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Capsular Polysaccharide ◽  
Carbapenem Resistant ◽  
Virulence Traits

scholarly journals Identification of a Depolymerase Specific for K64-Serotype Klebsiella pneumoniae: Potential Applications in Capsular Typing and Treatment

Antibiotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 144
Author(s):  
Jiayin Li ◽  
Yueying Sheng ◽  
Ruijing Ma ◽  
Mengsha Xu ◽  
Fuli Liu ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Capsular Polysaccharide ◽  
Vaccine Development ◽  
Preventive Intervention ◽  
Global Public Health ◽  
Carbapenem Resistant ◽  
Potential Applications ◽  
Typing Methods ◽  
Therapeutic Biologics ◽  
Capsular Typing

Carbapenem-resistant Klebsiella pneumoniae (CRKP), one of the major nosocomial pathogens, is increasingly becoming a serious threat to global public health. There is an urgent need to develop effective therapeutic and preventive approaches to combat the pathogen. Here, we identified and characterized a novel capsule depolymerase (K64-ORF41) derived from Klebsiella phage SH-KP152410, which showed specific activities for K. pneumoniae K64-serotype. We showed that this depolymerase could be used in the identification of K64 serotypes based on the capsular typing, and the results agreed well with those from the conventional serotyping method using antisera. From this study, we also identified K64 mutant strains, which showed typing discrepancy between wzi-sequencing based genotyping and depolymerase-based or antiserum-based typing methods. Further investigation indicated that the mutant strain has an insertion sequence (IS) in wcaJ, which led to the alteration of the capsular serotype structure. We further demonstrated that K64-ORF41 depolymerase could sensitize the bacteria to serum or neutrophil killing by degrading the capsular polysaccharide. In summary, the identified K64 depolymerase proves to be an accurate and reliable tool for capsular typing, which will facilitate the preventive intervention such as vaccine development. In addition, the polymerase may represent a potential and promising therapeutic biologics against CRKP-K64 infections.

scholarly journals Population Structure of KPC-Producing Klebsiella pneumoniae Isolates from Midwestern U.S. Hospitals

2014 ◽  
Vol 58 (8) ◽  
pp. 4961-4965 ◽  
Author(s):  
Meredith S. Wright ◽  
Federico Perez ◽  
Lauren Brinkac ◽  
Michael R. Jacobs ◽  
Keith Kaye ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Capsular Polysaccharide ◽  
Sequence Type ◽  
Single Nucleotide Variants ◽  
Single Nucleotide ◽  
Content Type ◽  
Strain Diversity ◽  
Carbapenem Resistant ◽  
Genetic Context ◽  
Over Time

ABSTRACTGenome sequencing of carbapenem-resistantKlebsiella pneumoniaeisolates from regional U.S. hospitals was used to characterize strain diversity and theblaKPCgenetic context. A phylogeny based on core single-nucleotide variants (SNVs) supports a division of sequence type 258 (ST258) into two distinct groups. The primary differences between the groups are in the capsular polysaccharide locus (cps) and their plasmid contents. A strict association between clade and KPC variant was found. TheblaKPCgene was found on variants of two plasmid backbones. This study indicates that highly similarK. pneumoniaesubpopulations coexist within the same hospitals over time.

scholarly journals The capsular polysaccharide and lipopolysaccharide structures of two carbapenem resistant Klebsiella pneumoniae outbreak isolates

2013 ◽  
Vol 369 ◽  
pp. 6-9 ◽  
Author(s):  
Joanna Kubler-Kielb ◽  
Evgeny Vinogradov ◽  
Weng-Ian Ng ◽  
Beata Maczynska ◽  
Adam Junka ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Capsular Polysaccharide ◽  
Carbapenem Resistant

scholarly journals Reduced virulence and enhanced host adaption during antibiotics therapy: A story of a within-host carbapenem-resistant Klebsiella pneumoniae sequence type 11 evolution in a fatal scrotal abscess patient

2021 ◽  
Author(s):  
Meiping Ye ◽  
Chunjie Liao ◽  
Mengya Shang ◽  
Danyang Zou ◽  
Jingmin Yan ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Binding Site ◽  
Biofilm Formation ◽  
Capsular Polysaccharide ◽  
Human Life ◽  
Sequence Type ◽  
Genomic Diversity ◽  
Rna Seq ◽  
Carbapenem Resistant ◽  
Virulence Attenuation

Carbapenem-resistant Klebsiella pneumoniae (CRKP) has disseminated globally and become a major threat to human life. The sequence type (ST) 11 CRKP is a dominant clone in Asia, especially China, but how this clone evolves in vivo, then adapts to host and facilitates dissemination remain largely unknown. We analyzed the genomic dynamics of 4 ST11-CRKP isolates sequencially isolated from the urine of a patient with initial fatal scrotal abscess and finally recovered without effective medication. Genomic differences were identified and their implications for pathogenesis and host adaptation were investigated. The related transcriptional pathways were further explored by RNA-Seq. Genomic analysis identified 4-24 mutations and 94%-100% were synonymous or intergenic. The mutation rate of ST11-CRKP was 2.1×10-6-1.7×10-5 substitutions/site/year over 47 days of antibiotics therapy. During this period, CRKP underwent several adaptive changes including tigecycline resistance and virulence attenuation. Tigecycline resistance was caused by ramR ribosomal binding site (RBS) deletion, which has been described by us previously. In this study, we demonstrated that mutations associated with acyltransferase (act) and ompK26 caused the virulence attenuation of ST11-CRKP. act deletion reduced the production of capsular polysaccharide and enhanced biofilm formation. RNA-Seq analysis revealed that act influenced the expression of ldhA, bglX, mtnK and metE which likely participate in capsular synthesis and biofilm formation. ompK26 affected the virulence by its overexpression caused by the deletion of upstream repressor binding site. Our finding suggested that the broad genomic diversity, high evolutionary capacity and rapid within-host adaptability of ST11-CRKP might contribute to the worldwide dissemination of this clone.

scholarly journals Outbreak of KPC-2 Carbapenem-Resistant Klebsiella pneumoniae ST76 and Carbapenem-Resistant K2 Hypervirulent Klebsiella pneumoniae ST375 Strains in Northeast China: Molecular and Virulent Characteristics

2019 ◽  
Author(s):  
Shanshan Su ◽  
Yongxin Zhao ◽  
Lan Yu ◽  
Chunjiang Li ◽  
Yong Wang ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Klebsiella Pneumoniae ◽  
Biofilm Formation ◽  
Northeast China ◽  
Capsular Polysaccharide ◽  
Molecular Characteristics ◽  
Circular Chromosome ◽  
Carbapenem Resistant ◽  
Positive Isolate ◽  
Serotype K2

Abstract Background Carbapenem-resistant hypervirulent Klebsiella pneumoniae strains have recently come into existence worldwide; however, researchers in northeast China are not aware of their clinical features and molecular characteristics. Methods Here, the molecular and virulent characteristics of 44 carbapenem-resistant K. pneumoniae (CRKP) isolates collected from January 2015 to December 2017 were studied. Multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) were carried out to define the clonal relatedness among the isolates. PCR and capsular serotyping of the virulence-associated genes, as well as biofilm formation and serum complement-mediated killing assays, were employed to determine the virulent potential. The genomic features and associated mobile genetic elements of JmsCRE57 were detected by whole genome sequencing. Results The only positive isolate was JmsCRE57, which belonged to the ST375 serotype K2 that expressed uge, mrkD, fimH, kpn, aerobactin and rmpA virulence-associated genes and showed strong biofilm formation and serum sensitivity. Sequencing results showed that the JmsCRE57 genome mainly consisted of a circular chromosome, three antibiotic resistance plasmids and a virulent plasmid. The antibiotic resistance plasmid expressing blaKPC-2, blaCTX-M-15, aph(3'')-Ib, aph(6)-Id, qnrB1, aac(3)-IIa, aac(6')-Ib-cr, blaOXA-1, blaTEM-1B, catB4, sul2, dfrA14 and blaSHV-99. The virulent plasmid belonged to the IncHI1B group, which is mainly composed of capsular polysaccharide genes and siderophore-associated genes. The remaining CRKP strains that expressed uge, fimH, mrkD and kpn virulence-associated genes were not successfully typed. We also identified an isolate that expressed the alls gene. Conclusion Our results provide new insights on the epidemiology of carbapenem-resistant K2 hypervirulent K. pneumoniae ST375 and CRKP ST76 strains in northeast China, which may help control their future outbreaks.

scholarly journals The Role of IgG Subclass in Antibody-Mediated Protection against Carbapenem-Resistant Klebsiella pneumoniae

mBio ◽  
2020 ◽  
Vol 11 (5) ◽  
Author(s):  
Michael P. Motley ◽  
Elizabeth Diago-Navarro ◽  
Kasturi Banerjee ◽  
Sean Inzerillo ◽  
Bettina C. Fries
Keyword(s):  
Monoclonal Antibodies ◽  
Klebsiella Pneumoniae ◽  
Capsular Polysaccharide ◽  
Resistant Bacteria ◽  
Infection Model ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Neutropenic Patients ◽  
Antibody Subclass

ABSTRACT Monoclonal antibodies (MAbs) have the potential to assist in the battle against multidrug-resistant bacteria such as carbapenem-resistant Klebsiella pneumoniae (CR-Kp). However, the characteristics by which these antibodies (Abs) function, such as the role of antibody subclass, must be determined before such modalities can be carried from the bench to the bedside. We performed a subclass switch on anticapsular monoclonal murine IgG3 (mIgG3) hybridomas and identified and purified a murine IgG1 (mIgG1) hybridoma line through sib selection. We then compared the ability of the mIgG1 and mIgG3 antibodies to control CR-Kp sequence type 258 (ST258) infection both in vitro and in vivo. We found by enzyme-limited immunosorbent assay (ELISA) and flow cytometry that mIgG3 has superior binding to the CR-Kp capsular polysaccharide (CPS) and superior agglutinating ability compared to mIgG1. The mIgG3 also, predictably, had better complement-mediated serum bactericidal activity than the mIgG1 and also promoted neutrophil-mediated killing at concentrations lower than that of the mIgG1. In contrast, the mIgG1 had marginally better activity in improving macrophage-mediated phagocytosis. Comparing their activities in a pulmonary infection model with wild-type as well as neutropenic mice, both antibodies reduced organ burden in a nonlethal challenge, regardless of neutrophil status, with mIgG1 having the highest overall burden reduction in both scenarios. However, at a lethal inoculum, both antibodies showed reduced efficacy in neutropenic mice, with mIgG3 retaining the most activity. These findings suggest the viability of monoclonal Ab adjunctive therapy in neutropenic patients that cannot mount their own immune response, while also providing some insight into the relative contributions of immune mediators in CR-Kp protection. IMPORTANCE Carbapenem-resistant Klebsiella pneumoniae is an urgent public health threat that causes life-threatening infections in immunocompromised hosts. Its resistance to nearly all antibiotics necessitates novel strategies to treat it, including the use of monoclonal antibodies. Monoclonal antibodies are emerging as important adjuncts to traditional pharmaceuticals, and studying how they protect against specific bacteria such as Klebsiella pneumoniae is crucial to their development as effective therapies. Antibody subclass is often overlooked but is a major factor in how an antibody interacts with other mediators of immunity. This paper is the first to examine how the subclass of anticapsular monoclonal antibodies can affect efficacy against CR-Kp. Additionally, this work sheds light on the viability of monoclonal antibody therapy in neutropenic patients, who are most vulnerable to CR-Kp infection.

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