A Study of the Virulence Traits of Carbapenem-Resistant Klebsiella pneumoniae Isolates in a Galleria mellonella Model

2019 ◽  
Vol 25 (7) ◽  
pp. 1063-1071 ◽  
Author(s):  
Mahmoud A.F. Khalil ◽  
Raghda Hager ◽  
Fadwa Abd-El Reheem ◽  
Eman E. Mahmoud ◽  
Tamer Samir ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Galleria Mellonella ◽  
Carbapenem Resistant ◽  
Virulence Traits

scholarly journals An Outbreak of Carbapenem-Resistant Klebsiella Pneumoniae of K57 Capsular Serotype in an Emergency Intensive Care Unit of a Teaching Hospital in China

2020 ◽  
Author(s):  
Chunhong Shao ◽  
Yan Jin ◽  
Shuang Liu ◽  
Meijie Jiang ◽  
Shuping Zhao
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Klebsiella Pneumoniae ◽  
Teaching Hospital ◽  
Galleria Mellonella ◽  
Pulse Field ◽  
Carbapenem Resistant ◽  
Surrounding Environment ◽  
Antimicrobial Resistance Genes ◽  
Broth Microdilution Method

Abstract Background: Klebsiella pneumoniae is a common causative pathogen of nosocomial infections. The emergence of carbapenem-resistant hypervirulent K. pneumoniae (CR-hvKP) strains has further increased the threat posed by this bacterium. Here, we described an outbreak of 32 CR-hvKP isolates from the emergency intensive care unit (EICU) of a teaching hospital in China. Methods: From January 29, 2019 to March 11, 2019, 32 CRKp isolates were collected from 6 patients and their surrounding environment in EICU. Patient information including age, gender, length of EICU stay, diagnosis, treatment, and outcomes were obtained from electronic medical records. The isolates were identified using Vitek-MS system. The hypermucoviscosity phenotype was determined by the “string test”. Antimicrobial susceptibility testing was performed using VITEK 2 compact system, E-test or the broth microdilution method. All isolates were serotyped for K1, K2, K5, K20, K54, and K57 serotypes, antimicrobial resistance genes and twelve virulence-associated genes were screened using PCR and DNA sequencing. Multilocus sequence typing (MLST) and pulse-field gel electrophoresis (PFGE) were employed to characterize the genetic relationships among the CPKP isolates. The virulence capability of 11 CRKp isolates from 6 patients was evaluated through Galleria mellonella larva infection assay. Results: This outbreak involved 6 patients and lasted for 40 days. All 32 CR-hvKp isolates were obtained from 6 patients and their surrounding environment. PFGE showed that all 32 isolates belonged to one cluster, and MLST revealed that belonged to ST11. All isolates exhibited high resistance to β-lactam antibiotics, quinolones, and aminoglycosides. They were susceptible to ceftazidime/averbatan, tigecycline, and colistin. All 32 isolates harbored multiple resistance determinants, including blaKPC-2, blaSHV-11, blaTEM-1, rmtB, and qnrD. The serotype of all 32 isolates was K57 that was rarely reported. In the virulence gene analysis, all 32 isolates contained 6 virulence genes, namely, fimH, iucB, mrkD, rmpA, uge, and wabG. Infection assays demonstrated high mortality in the Galleria mellonella model. Following measures implemented by the hospital, the outbreak was controlled. The mortality rate was 83.3%.Conclusions: The epidemiology of CR-hvKP should be monitored closely to detect early indications of this emerging public health threat.

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

Evolution of hypervirulence in carbapenem-resistant Klebsiella pneumoniae in China: a multicentre, molecular epidemiological analysis

2019 ◽  
Vol 75 (2) ◽  
pp. 327-336 ◽  
Author(s):  
Yawei Zhang ◽  
Longyang Jin ◽  
Pengwen Ouyang ◽  
Qi Wang ◽  
Ruobing Wang ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Virulence Genes ◽  
Galleria Mellonella ◽  
Infection Model ◽  
Epidemiological Analysis ◽  
Virulence Plasmids ◽  
Carbapenem Resistant ◽  
Resistance Plasmid ◽  
Serum Killing ◽  
Evolution Of Resistance

Abstract Objectives Carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) have been increasingly reported in China. Here, a multicentre, longitudinal surveillance study on CR-hvKP is described. Methods We retrospectively investigated carbapenem-resistant K. pneumoniae (CRKP) in 56 centres across China during 2015–17 and screened the virulence genes (iucA, iroN, rmpA and rmpA2) for the presence of virulence plasmids. Hypermucoviscosity, serum killing and Galleria mellonella lethality experiments were conducted to identify CR-hvKP among strains with all four virulence genes. Capsule typing, fitness and plasmid features of CR-hvKP were also investigated. Results A total of 1052 CRKP were collected. Among these, 34.2% (360/1052) carried virulence genes and 72 of them had all four of the virulence genes tested. Fifty-five (76.4%) were considered to be CR-hvKP using the G. mellonella infection model, with KPC-2-producing K64-ST11 being the most common type (80%, 44/55). Prevalence of CR-hvKP differed greatly between regions, with the highest in Henan (25.4%, 17/67) and Shandong (25.8%, 25/97). A significant increase in CR-hvKP among KPC-2-producing ST11 strains was observed, from 2.1% (3/141) in 2015 to 7.0% (23/329) in 2017 (P=0.045). Alarmingly, compared with classic CRKP, no difference in growth was found among CR-hvKP (P=0.7028), suggesting a potential risk for dissemination. The hybrid virulence and resistance-encoding plasmid evolved from pLVPK and the resistance plasmid harbouring blaKPC-2, indicating evolution existed between the hypervirulence and hyper-resistance plasmid. Conclusions CR-hvKP were more frequently detected than previously assumed, especially among KPC-2-producing ST11. Dissemination of hypervirulence could be extremely rapid due to limited fitness cost. Also, the evolution of resistance genes into hypervirulence plasmids was identified, presenting significant challenges for public health and infection control.

scholarly journals Komodo-dragon cathelicidin-inspired peptides are antibacterial against carbapenem-resistant Klebsiella pneumoniae

2020 ◽  
Vol 69 (11) ◽  
pp. 1262-1272
Author(s):  
Samantha J. Hitt ◽  
Barney M. Bishop ◽  
Monique L. van Hoek
Keyword(s):  
Antimicrobial Activity ◽  
Klebsiella Pneumoniae ◽  
Antimicrobial Peptides ◽  
Galleria Mellonella ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Level Of Activity ◽  
Improvement In Survival ◽  
Synthetic Antimicrobial Peptides

Introduction. The rise of carbapenem-resistant enterobacteriaceae (CRE) is a growing crisis that requires development of novel therapeutics. Hypothesis. To this end, cationic antimicrobial peptides (CAMPs) represent a possible source of new potential therapeutics to treat difficult pathogens such as carbapenem-resistant Klebsiella pneumoniae (CRKP), which has gained resistance to many if not all currently approved antibiotics, making treatment difficult. Aim. To examine the anti-CRKP antimicrobial activity of the predicted cathelicidins derived from Varanus komodoensis (Komodo dragon) as well as synthetic antimicrobial peptides that we created. Methodology. We determined the minimum inhibitory concentrations of the peptides against CRKP. We also characterized the abilities of these peptides to disrupt the hyperpolarization of the bacterial membrane as well as their ability to form pores in the membrane. Results. We did not observe significant anti-CRKP activity for the predicted native Komodo cathelicidin peptides. We found that the novel peptides DRGN-6,-7 and -8 displayed significant antimicrobial activity against CRKP with MICs of 4–8 µg ml−1. DRGN-6 peptide was the most effective peptide against CRKP. Unfortunately, these peptides showed higher than desired levels of hemolysis, although in vivo testing in the waxworm Galleria mellonella showed no mortality associated with treatment by the peptide; however, CRKP-infected waxworms treated with peptide did not show an improvement in survival. Conclusion. Given the challenges of treating CRKP, identification of peptides with activity against it represents a promising avenue for further research. Given DRGN-6′s similar level of activity to colistin, DRGN-6 is a promising template for the development of novel antimicrobial peptide-based therapeutics.

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 Yersiniabactin, Colibactin and Wider Resistome Contribute to Enhanced Virulence and Persistence of KPC-2-Producing Klebsiella pneumoniae CG258 in South America

2018 ◽  
Author(s):  
Louise T. Cerdeira ◽  
Fernanda Esposito ◽  
Margaret M. C. Lam ◽  
Kelly L. Wyres ◽  
Ryan R. Wick ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
South America ◽  
Galleria Mellonella ◽  
Genomic Analysis ◽  
Public Health Issue ◽  
Infection Model ◽  
Veterinary Antibiotics ◽  
Carbapenem Resistant ◽  
Clonal Origin ◽  
Sequence Types

AbstractThe emergence and dissemination of carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKp) is a worrisome public health issue compromising the treatment and outcome of infections caused by this pathogen. We performed a detailed virulome and resistome analysis of representative KPC- and/or CTX-M-producing K. pneumoniae belonging to clonal group (CG) 258 (sequence types ST11, ST258, ST340, ST437), circulating in Argentina, Brazil, Chile, Colombia and Peru; with further evaluation of the virulence behavior using the Galleria mellonella infection model. Genomic analysis of K. pneumoniae strains recovered from the human-animal-environment interface revealed a wide resistome characterized by the presence of genes and mutations conferring resistance to human and veterinary antibiotics, quaternary ammonium compounds (QACs) and heavy metals. Plasmid Inc typing revealed the presence of a wide diversity of replicon types with IncF, IncN, IncR and Col-like being frequently detected. Moreover, KPC-2-producing K. pneumoniae belonging to ST11 (KL-64 andKL-105) and ST340 (KL-15) carried multiple variants of distinct yersiniabactin siderophore (ybt) and/or genotoxic colibactin (clb) genes. In this regard, ICEKp3, ICEKp4 and ICEKp12 were identified in strains belonging to ST11 and ST340, recovered from Argentina, Brazil, Chile and Colombia; whereas ybt 17 and a novel ybt sequence type (YbST346) were identified together with clb in ICEKp10 structures from ST11 and ST258, from Brazil and Colombia, respectively. K. pneumoniae ST11 (ICEKp10/YbST346 and ICEKp4/ybt 10) strains killed 100% of wax moth larvae, in a similar way to hypervirulent K1/ST23 strain (ybt- and clb-negative) carrying the pLVPK-like plasmid, indicating enhanced virulence. In summary, our results indicate that yersiniabactin, colibactin and an expanded resistome have contributed to enhanced virulence and persistence of KPC-2-producing K. pneumoniae CG258 in South America. Therefore, active surveillance of hospital-associated lineages of K. pneumoniae should not only focus on clonal origin and antimicrobial resistance, but also on the virulence factors ybt and clb.

scholarly journals Bacteriophage SRD2021 Recognizing Capsular Polysaccharide Shows Therapeutic Potential in Serotype K47 Klebsiella pneumoniae Infections

Antibiotics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 894
Author(s):  
Guijuan Hao ◽  
Rundong Shu ◽  
Liqin Ding ◽  
Xia Chen ◽  
Yonghao Miao ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Capsular Polysaccharide ◽  
Galleria Mellonella ◽  
Therapeutic Potential ◽  
Protein A ◽  
Opportunistic Pathogen ◽  
Tail Fiber ◽  
Global Public Health ◽  
Transposon Insertion ◽  
Carbapenem Resistant

Klebsiella pneumoniae is an opportunistic pathogen posing an urgent threat to global public health, and the capsule is necessary for K. pneumoniae infection and virulence. Phage-derived capsule depolymerases have shown great potential as antivirulence agents in treating carbapenem-resistant K. pneumoniae (CRKP) infections. However, the therapeutic potential of phages encoding depolymerases against CRKP remains poorly understood. In this study, we identified a long-tailed phage SRD2021 specific for mucoid CRKP with capsular K47 serotype, which is the predominant infectious K-type in Asia. Genome sequencing revealed that ΦSRD2021 belonged to the Drulisvirus genus and exhibited a capsular depolymerase domain in its tail fiber protein. A transposon-insertion library of host bacteria was constructed to identify the receptor for ΦSRD2021. We found that most phage-resistant mutants converted to a nonmucoid phenotype, including the mutant in wza gene essential for capsular polysaccharides export. Further knockout and complementation experiments confirmed that the Δwza mutant avoided adsorption by ΦSRD2021, indicating that the K47 capsular polysaccharide is the necessary receptor for phage infection. ΦSRD2021 lysed the bacteria mature biofilms and showed a therapeutic effect on the prevention and treatment of CRKP infection in the Galleria mellonella model. Furthermore, ΦSRD2021 also reduced the colonized CRKP in mouse intestines significantly. By recognizing the host capsule as a receptor, our results showed that ΦSRD2021 may be used as a potential antibacterial agent for K47 serotype K. pneumoniae infections.

scholarly journals In VitroandIn VivoActivities of Tigecycline-Colistin Combination Therapies against Carbapenem-Resistant Enterobacteriaceae

2014 ◽  
Vol 58 (6) ◽  
pp. 3541-3546 ◽  
Author(s):  
Jonathan W. Betts ◽  
Lynette M. Phee ◽  
Michael Hornsey ◽  
Neil Woodford ◽  
David W. Wareham
Keyword(s):  
Escherichia Coli ◽  
Animal Model ◽  
Klebsiella Pneumoniae ◽  
Galleria Mellonella ◽  
Combination Therapies ◽  
Viable Option ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Carbapenem Resistant Enterobacteriaceae

ABSTRACTWe assessed the activity of tigecycline (TGC) combined with colistin (COL) against carbapenem-resistant enterobacteria. Synergy occurredin vitroagainst the majority of isolates, with the exception ofSerratia marcescens. In a simple animal model (Galleria mellonella), TGC-COL was superior (P< 0.01) in treatingEscherichia coli,Klebsiella pneumoniae, andEnterobacterinfections, including those with TGC-COL resistance. Clinical studies are needed to determine whether TGC-COL regimens may be a viable option.

scholarly journals The Emergence of Novel Sequence Type Strains Reveals an Evolutionary Process of Intraspecies Clone Shifting in ICU-Spreading Carbapenem-Resistant Klebsiella pneumoniae

2021 ◽  
Vol 12 ◽  
Author(s):  
Dongdong Zhao ◽  
Qiucheng Shi ◽  
Dandan Hu ◽  
Li Fang ◽  
Yihan Mao ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Galleria Mellonella ◽  
Sequence Similarity ◽  
Public Health Problem ◽  
Infection Model ◽  
Virulence Determinants ◽  
Clinical Environment ◽  
Typing Method ◽  
Phylogenetic Structure ◽  
Carbapenem Resistant

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is an urgent public health problem worldwide, and its rapid evolution in the clinical environment has been a major concern. A total of 99 CRKP isolates spreading in the intensive care unit (ICU) setting were included and subjected to whole-genome sequencing, and their sequence types (STs), serotype loci, and virulence determinants were screened based on genome data. The phylogenetic structure was reconstructed based on the core genome multilocus sequence typing method. Regions of recombination were assessed. Biofilm formation, serum resistance assays, and a Galleria mellonella infection model were used to evaluate strain virulence. A novel ST, designated ST4496, emerged in the ICU and spread for 6 months before its disappearance. ST4496 was closely related to ST11, with only a single-allele variant, and ST11 is the most dominant clinical clone in China. Recombination events occurred at capsule biosynthesis loci and divided the strains of ST11 and its derivative ST4496 into three clusters, including ST11-KL47, ST11-KL64, and ST4496-KL47. The phylogenetic structure indicated that ST11-KL47 was probably the origin of ST11-related strain evolution and presented more diversity in terms of both sequence similarity and phenotypes. ST4496-KL47 cluster strains presented less virulence than ST11-KL64, which was probably one of the factors preventing the former from spreading widely. In conclusion, ST4496-KL47 was probably derived from ST11-KL47 via intraspecies shifting but was less competitive than ST11-KL64, which also evolved from ST11-KL47 and developed increased virulence via capsule biosynthesis locus recombination. ST11-KL64 has the potential to be the predominant CRKP clone in China.

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