scholarly journals Acquisition of the Conjugative Virulence Plasmid From a CG23 Hypervirulent Klebsiella pneumoniae Strain Enhances Bacterial Virulence

2021 ◽  
Vol 11 ◽  
Author(s):  
Dongxing Tian ◽  
Weiwen Wang ◽  
Meng Li ◽  
Wenjie Chen ◽  
Ying Zhou ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Biofilm Formation ◽  
Evidence Base ◽  
Serum Resistance ◽  
Virulence Plasmid ◽  
E Coli ◽  
Virulence Plasmids ◽  
Carbapenem Resistant ◽  
High Level

The emergence of hypervirulent and carbapenem-resistant Klebsiella pneumoniae (hv-CRKP) has become a hot topic and confounding problem for clinicians and researchers alike. Conjugative virulence plasmids have the potential to cause more threatening dissemination of hv-CRKP strains. We previously identified K2606, a CG23 clinical hypervirulent strain of Klebsiella pneumoniae harboring a conjugative virulence plasmid designated pK2606. In this study we examined hypervirulence levels using assays of biofilm formation, serum resistance, and wax larvae and mouse in vivo infection models. Moreover, to define the transfer ability of pK2606 and whether this confers hypervirulence to other strains we performed plasmid transconjugation experiments between K2606 and the ST11 CRKP strain HS11286 along with E. coli J53. We found that although biofilm formation and serum resistance were not significantly increased, the transconjugants acquired the ability of produce high level of siderophores and also caused high mortality of wax larvae and mice. Furthermore, we identified pK2606-like conjugative virulence plasmids in GenBank, providing evidence that such plasmids may have begun to spread throughout China. These findings provide an evidence base for the possible mechanisms of the emergence of hv-CRKP strains and highlight the potential of pK2606-like conjugative virulence plasmids to spread worldwide.

scholarly journals Mobilization of the nonconjugative virulence plasmid from hypervirulent Klebsiella pneumoniae

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Yanping Xu ◽  
Jianfeng Zhang ◽  
Meng Wang ◽  
Meng Liu ◽  
Guitian Liu ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
In Silico ◽  
In Silico Analysis ◽  
Conjugative Plasmid ◽  
Virulence Plasmid ◽  
E Coli ◽  
Virulence Plasmids ◽  
Carbapenem Resistant ◽  
Helper Plasmids ◽  
Silico Analysis

Abstract Background Klebsiella pneumoniae, as a global priority pathogen, is well known for its capability of acquiring mobile genetic elements that carry resistance and/or virulence genes. Its virulence plasmid, previously deemed nonconjugative and restricted within hypervirulent K. pneumoniae (hvKP), has disseminated into classic K. pneumoniae (cKP), particularly carbapenem-resistant K. pneumoniae (CRKP), which poses alarming challenges to public health. However, the mechanism underlying its transfer from hvKP to CRKP is unclear. Methods A total of 28 sequence type (ST) 11 bloodstream infection-causing CRKP strains were collected from Ruijin Hospital in Shanghai, China, and used as recipients in conjugation assays. Transconjugants obtained from conjugation assays were confirmed by XbaI and S1 nuclease pulsed-field gel electrophoresis, PCR detection and/or whole-genome sequencing. The plasmid stability of the transconjugants was evaluated by serial culture. Genetically modified strains and constructed mimic virulence plasmids were employed to investigate the mechanisms underlying mobilization. The level of extracellular polysaccharides was measured by mucoviscosity assays and uronic acid quantification. An in silico analysis of 2608 plasmids derived from 814 completely sequenced K. pneumoniae strains available in GenBank was performed to investigate the distribution of putative helper plasmids and mobilizable virulence plasmids. Results A nonconjugative virulence plasmid was mobilized by the conjugative plasmid belonging to incompatibility group F (IncF) from the hvKP strain into ST11 CRKP strains under low extracellular polysaccharide-producing conditions or by employing intermediate E. coli strains. The virulence plasmid was mobilized via four modes: transfer alone, cotransfer with the conjugative IncF plasmid, hybrid plasmid formation due to two rounds of single-strand exchanges at specific 28-bp fusion sites or homologous recombination. According to the in silico analysis, 31.8% (242) of the putative helper plasmids and 98.8% (84/85) of the virulence plasmids carry the 28-bp fusion site. All virulence plasmids carry the origin of the transfer site. Conclusions The nonconjugative virulence plasmid in ST11 CRKP strains is putatively mobilized from hvKP or E. coli intermediates with the help of conjugative IncF plasmids. Our findings emphasize the importance of raising public awareness of the rapid dissemination of virulence plasmids and the consistent emergence of hypervirulent carbapenem-resistant K. pneumoniae (hv-CRKP) strains.

scholarly journals MCR-1 and OXA-48 In Vivo Acquisition in KPC-Producing Escherichia coli after Colistin Treatment

2017 ◽  
Vol 61 (8) ◽  
Author(s):  
Racha Beyrouthy ◽  
Frederic Robin ◽  
Aude Lessene ◽  
Igor Lacombat ◽  
Laurent Dortet ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Whole Genome ◽  
Content Type ◽  
First Report ◽  
E Coli ◽  
Carbapenem Resistant

ABSTRACT The spread of mcr-1-encoding plasmids into carbapenem-resistant Enterobacteriaceae raises concerns about the emergence of untreatable bacteria. We report the acquisition of mcr-1 in a carbapenem-resistant Escherichia coli strain after a 3-week course of colistin in a patient repatriated to France from Portugal. Whole-genome sequencing revealed that the Klebsiella pneumoniae carbapenemase-producing E. coli strain acquired two plasmids, an IncL OXA-48-encoding plasmid and an IncX4 mcr-1-encoding plasmid. This is the first report of mcr-1 in carbapenemase-encoding bacteria in France.

scholarly journals Four Carbapenem-Resistant Gram-Negative Species Carrying Distinct Carbapenemases in a Single Patient

2014 ◽  
Vol 53 (3) ◽  
pp. 1031-1033 ◽  
Author(s):  
Baixing Ding ◽  
Fupin Hu ◽  
Yang Yang ◽  
Qinglan Guo ◽  
Jinwei Huang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Klebsiella Pneumoniae ◽  
Acinetobacter Baumannii ◽  
Enterobacter Aerogenes ◽  
Single Patient ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Carbapenem Resistant

Carbapenem-resistantEscherichia coli,Klebsiella pneumoniae,Enterobacter aerogenes, andAcinetobacter baumanniiwere isolated from a single patient, each producing different carbapenemases (NDM-1, KPC-2, IMP, and OXA-23, respectively). The NDM-1-producingE. colistrain was preceded by a clonally related carbapenem-susceptible strain a month earlier, suggestingin vivoacquisition ofblaNDM-1.

scholarly journals Prevalence of Carbapenem-Resistant Klebsiella pneumoniae Co-Harboring blaKPC-Carrying Plasmid and pLVPK-Like Virulence Plasmid in Bloodstream Infections

2021 ◽  
Vol 10 ◽  
Author(s):  
Fang-ling Du ◽  
Qi-sen Huang ◽  
Dan-dan Wei ◽  
Yan-fang Mei ◽  
Dan Long ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Galleria Mellonella ◽  
Bloodstream Infections ◽  
Multi Drug Resistance ◽  
Virulence Plasmid ◽  
E Coli ◽  
Plasmid Gene ◽  
Carbapenem Resistant ◽  
Large Plasmids ◽  
Serotype K2

This study aimed to characterize carbapenem-resistant Klebsiella pneumoniae (CR-KP) co-harboring blaKPC-2-carrying plasmid and pLVPK-like virulence plasmid. Between December 2017 and April 2018, 24 CR-KP isolates were recovered from 24 patients with bacteremia. The mortality was 66.7%. Pulsed-field gel electrophoresis and multilocus sequence typing results indicated four clusters, of which cluster A (n = 21, 87.5%) belonged to ST11 and the three remaining isolates (ST412, ST65, ST23) had different pulsotypes (cluster B, C, D). The blaKPC-2-carrying plasmids all belonged to IncFIIK type, and the size ranged from 100 to 390 kb. Nineteen strains (79.2%) had a 219-kb virulence plasmid possessed high similarity to pLVPK from CG43 with serotype K2. Two strains had a 224-kb virulence plasmid resembled plasmid pK2044 from K. pneumoniae NTUH-K2044(ST23). Moreover, three strains carried three different hybrid resistance- and virulence-encoding plasmids. Conjugation assays showed that both blaKPC-2 and rmpA2 genes could be successfully transferred to E. coli J53 in 62.5% of the strains at frequencies of 4.5 × 10−6 to 2.4 × 10−4, of which three co-transferred blaKPC-2 along with rmpA2 in large plasmids. Infection assays in the Galleria mellonella model demonstrated the virulence level of these isolates was found to be consistently higher than that of classic Klebsiella pneumoniae. In conclusion, CR-KP co-harboring blaKPC-2-carrying plasmid and pLVPK-like virulence plasmid were characterized by multi-drug resistance, enhanced virulence, and transferability, and should, therefore, be regarded as a real superbug that could pose a serious threat to public health. Hence, heightened efforts are urgently needed to avoid its co-transmission of the virulent plasmid (gene) and resistant plasmid (gene) in clinical isolates.

scholarly journals Identification of a novel hybrid plasmid encoding KPC-2 and virulence factors in Klebsiella pneumoniae sequence type 11

2021 ◽  
Author(s):  
Longyang Jin ◽  
Ruobing Wang ◽  
Hua Gao ◽  
Qi Wang ◽  
Hui Wang
Keyword(s):  
Klebsiella Pneumoniae ◽  
Sequence Type ◽  
Hybrid Plasmid ◽  
Virulence Plasmids ◽  
Carbapenem Resistant ◽  
Clinical Challenge ◽  
Recent Emergence ◽  
Stable Maintenance

Recent emergence of carbapenem-resistant K. pneumoniae (CRKP) co-harbouring blaKPC-2 and pLVPK-like virulence plasmids represented a novel clinical challenge. In the present study, we characterized a blaKPC-2 and virulence hybrid plasmid, designated as pCRHV-C2244, from a clinical ST11-K64 CRKP strain. pCRHV-C2244 was non-self-transmissible due to the incomplete conjugative elements, but mobilizable together with a conjugative helper. Enhanced virulence and stable maintenance without significant fitness loss in its original host were confirmed in vitro and in vivo.

scholarly journals Novel Carbapenem-Hydrolyzing β-Lactamase, KPC-1, from a Carbapenem-Resistant Strain of Klebsiella pneumoniae

2001 ◽  
Vol 45 (4) ◽  
pp. 1151-1161 ◽  
Author(s):  
Hesna Yigit ◽  
Anne Marie Queenan ◽  
Gregory J. Anderson ◽  
Antonio Domenech-Sanchez ◽  
James W. Biddle ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Clavulanic Acid ◽  
Outer Membrane Proteins ◽  
Carbapenem Resistance ◽  
Kinetic Studies ◽  
The Novel ◽  
E Coli ◽  
Carbapenem Resistant ◽  
Extended Spectrum ◽  
High Level

ABSTRACT A Klebsiella pneumoniae isolate showing moderate to high-level imipenem and meropenem resistance was investigated. The MICs of both drugs were 16 μg/ml. The β-lactamase activity against imipenem and meropenem was inhibited in the presence of clavulanic acid. The strain was also resistant to extended-spectrum cephalosporins and aztreonam. Isoelectric focusing studies demonstrated three β-lactamases, with pIs of 7.2 (SHV-29), 6.7 (KPC-1), and 5.4 (TEM-1). The presence of bla SHV andbla TEM genes was confirmed by specific PCRs and DNA sequence analysis. Transformation and conjugation studies withEscherichia coli showed that the β-lactamase with a pI of 6.7, KPC-1 (K. pneumoniae carbapenemase-1), was encoded on an approximately 50-kb nonconjugative plasmid. The gene,bla KPC-1, was cloned in E. coli and shown to confer resistance to imipenem, meropenem, extended-spectrum cephalosporins, and aztreonam. The amino acid sequence of the novel carbapenem-hydrolyzing β-lactamase, KPC-1, showed 45% identity to the pI 9.7 carbapenem-hydrolyzing β-lactamase, Sme-1, fromSerratia marcescens S6. Hydrolysis studies showed that purified KPC-1 hydrolyzed not only carbapenems but also penicillins, cephalosporins, and monobactams. KPC-1 had the highest affinity for meropenem. The kinetic studies also revealed that clavulanic acid and tazobactam inhibited KPC-1. An examination of the outer membrane proteins of the parent K. pneumoniae strain demonstrated that the strain does not express detectable levels of OmpK35 and OmpK37, although OmpK36 is present. We concluded that carbapenem resistance in K. pneumoniae strain 1534 is mainly due to production of a novel Bush group 2f, class A, carbapenem-hydrolyzing β-lactamase, KPC-1, although alterations in porin expression may also play a role.

scholarly journals In vivo Emergence of Colistin and Tigecycline Resistance in Carbapenem-Resistant Hypervirulent Klebsiella pneumoniae During Antibiotics Treatment

2021 ◽  
Vol 12 ◽  
Author(s):  
Jiawei Chen ◽  
Yu Zeng ◽  
Rong Zhang ◽  
Jiachang Cai
Keyword(s):  
Klebsiella Pneumoniae ◽  
Galleria Mellonella ◽  
Survival Rates ◽  
Fold Increase ◽  
Conjugative Plasmid ◽  
Virulence Plasmid ◽  
Carbapenem Resistant ◽  
Antimicrobial Resistance Genes

Three carbapenem-resistant Klebsiella pneumoniae (CRKP; strains KP-426, KP-C76, and KP-CT77) were isolated from a patient with severe burns during the treatment of colistin and tigecycline. Single-nucleotide polymorphism typing showed that three ST11 CRKP were clonally related. Three isolates harbored the same set of antimicrobial resistance genes. blaKPC-2, blaSHV-12, blaTEM-1, and rmtB genes were located on the same 128,928-bp IncFII/IncR plasmid. Tet(A), catA2, sul2, and dfrA14 genes were located on a plasmid with an unknown Inc-type. blaSHV-11, fosA, and aadA2 were chromosomal genes. An IS1 and an ISKpn14 were found in the promoter region of the mgrB gene of two colistin-resistant CRKP, K. pneumoniae KP-C76, and KP-CT77, respectively. A novel amino acid substitution, G300E, was identified in the type 1 Tet(A) variant of K. pneumoniae KP-CT77 which exhibited high-level tigecycline resistance compared to strains KP-426 and KP-C76 (MIC of 32, 4, and 4mg/l, respectively). Conjugation and cloning experiments confirmed that the mutated Tet(A) resulted in a 4-fold increase in tigecycline minimal inhibitory concentration (MIC) of Escherichia coli. Three CRKP belonged to the K64 serotype and possessed a similar IncHI1B/repB virulence plasmid carrying rmpA, rmpA2, and iucABCDiutA. The survival rates of Galleria Mellonella injected with K. pneumoniae KP-426, KP-C76, and KP-CT77 were 4.2, 20.8, and 8.3%, respectively. The emergence of colistin and tigecycline resistance in carbapenem-resistant hypervirulent K. pneumoniae posed a serious threat to clinical anti-infective therapy. The type 1 Tet(A) variant carrying G300E mutation, which conferred significantly elevated tigecycline MIC and was located on a conjugative plasmid, needs attention.

Difference in biofilm formation between carbapenem-resistant and carbapenem-sensitive Klebsiella pneumoniae based on analysis of mrkH distribution

2021 ◽  
Vol 152 ◽  
pp. 104743
Author(s):  
Renchi Fang ◽  
Haiyang Liu ◽  
Xiucai Zhang ◽  
Guofeng Dong ◽  
Jiahui Li ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Biofilm Formation ◽  
Carbapenem Resistant

scholarly journals Kinetics of Targeted Phage Rescue in a Mouse Model of SystemicEscherichia coliK1

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
György Schneider ◽  
Nikolett Szentes ◽  
Marianna Horváth ◽  
Ágnes Dorn ◽  
Alysia Cox ◽  
...  
Keyword(s):  
Capsular Polysaccharide ◽  
Protective Efficacy ◽  
Lytic Bacteriophage ◽  
E Coli ◽  
Causative Agents ◽  
High Level ◽  
Systemic Infections ◽  
Kinetics Of

Escherichia (E.) coliK1 strains remain common causative agents of neonatal sepsis and meningitis. We have isolated a lytic bacteriophage (ΦIK1) againstE. colistrain IHE3034 and tested its specificityin vitro, as well as distribution and protective efficacyin vivo. The phage was shown to be specific to the K1 capsular polysaccharide. In the lethal murine model, a high level of protection was afforded by the phage with strict kinetics. A single dose of 1 x 108phage particles administered 10 and 60 minutes following the bacterial challenge elicited 100 % and 95 % survival, respectively. No mice could be rescued if phage administration occurred 3 hours postinfection. Tissue distribution surveys in the surviving mice revealed that the spleen was the primary organ in which accumulation of active ΦIK1 phages could be detected two weeks after phage administration. These results suggest that bacteriophages have potential as therapeutic agents in the control of systemic infections.

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