scholarly journals An IncR Plasmid Harbored by a Hypervirulent Carbapenem-Resistant Klebsiella pneumoniae Strain Possesses Five Tandem Repeats of the blaKPC-2::NTEKPC-Id Fragment

2018 ◽  
Vol 63 (3) ◽  
Author(s):  
Ning Dong ◽  
Lizhang Liu ◽  
Rong Zhang ◽  
Kaichao Chen ◽  
Miaomiao Xie ◽  
...  

ABSTRACT Completed sequences of three plasmids from a carbapenem-resistant hypervirulent Klebsiella pneumoniae isolate, SH9, were obtained. In addition to the pLVPK-like virulence-conferring plasmid (pVir-CR-HvKP_SH9), the two multidrug-resistant plasmids (pKPC-CR-HvKP4_SH9 and pCTX-M-CR-HvKP4_SH9) were predicted to originate from a single pKPC-CR-HvKP4-like multireplicon plasmid through homologous recombination. Interestingly, the blaKPC-2 gene was detectable in five tandem repeats exhibiting the format of an NTEKPC-Id-like transposon (IS26-ΔTn3-ISKpn8-blaKPC-2-ΔISKpn6-korC-orf-IS26). The data suggest an important role of DNA recombination in mediating active plasmid evolution.

2020 ◽  
Vol 6 (12) ◽  
Author(s):  
Katlego Kopotsa ◽  
Nontombi M. Mbelle ◽  
John Osei Sekyere

Carbapenem-resistant Klebsiella pneumoniae (CRKP) remains a major clinical pathogen and public health threat with few therapeutic options. The mobilome, resistome, methylome, virulome and phylogeography of CRKP in South Africa and globally were characterized. CRKP collected in 2018 were subjected to antimicrobial susceptibility testing, screening by multiplex PCR, genotyping by repetitive element palindromic (REP)-PCR, plasmid size, number, incompatibility and mobility analyses, and PacBio’s SMRT sequencing (n=6). There were 56 multidrug-resistant CRKP, having bla OXA-48-like and bla NDM-1/7 carbapenemases on self-transmissible IncF, A/C, IncL/M and IncX3 plasmids endowed with prophages, traT, resistance islands, and type I and II restriction modification systems (RMS). Plasmids and clades detected in this study were respectively related to globally established/disseminated plasmids clades/clones, evincing transboundary horizontal and vertical dissemination. Reduced susceptibility to colistin occurred in 23 strains. Common clones included ST307, ST607, ST17, ST39 and ST3559. IncFIIk virulent plasmid replicon was present in 56 strains. Whole-genome sequencing of six strains revealed least 41 virulence genes, extensive ompK36 mutations, and four different K- and O-loci types: KL2, KL25, KL27, KL102, O1, O2, O4 and O5. Types I, II and III RMS, conferring m6A (G A TC, G A TGNNNNNNTTG, CA A NNNNNNCATC motifs) and m4C (C C WGG) modifications on chromosomes and plasmids, were found. The nature of plasmid-mediated, clonal and multi-clonal dissemination of blaOXA-48-like and blaNDM-1 mirrors epidemiological trends observed for closely related plasmids and sequence types internationally. Worryingly, the presence of both bla OXA-48 and bla NDM-1 in the same isolates was observed. Plasmid-mediated transmission of RMS, virulome and prophages influence bacterial evolution, epidemiology, pathogenicity and resistance, threatening infection treatment. The influence of RMS on antimicrobial and bacteriophage therapy needs urgent investigation.


mBio ◽  
2018 ◽  
Vol 9 (3) ◽  
Author(s):  
Roberto Adamo ◽  
Immaculada Margarit

ABSTRACT Antibiotics and vaccines have greatly impacted human health in the last century by dramatically reducing the morbidity and mortality associated with infectious diseases. The recent challenge posed by the emergence of multidrug-resistant bacteria could possibly be addressed by novel immune prophylactic and therapeutic approaches. Among the newly threatening pathogens, Klebsiella pneumoniae is particularly worrisome in the nosocomial setting, and its surface polysaccharides are regarded as promising antigen candidates. The majority of Klebsiella carbapenem-resistant strains belong to the sequence type 158 (ST258) lineage, with two main clades expressing capsular polysaccharides CPS1 and CPS2. In a recent article, S. D. Kobayashi and colleagues (mBio 9:e00297-18, 2018, https://doi.org/10.1128/mBio.00297-18) show that CPS2-specific IgGs render ST258 clade 2 bacteria more sensitive to human serum and phagocytic killing. E. Diago-Navarro et al. (mBio 9:e00091-18, 2018, https://doi.org/10.1128/mBio.00091-18) generated two murine monoclonal antibodies recognizing distinct glycotopes of CPS2 that presented functional activity against multiple ST258 strains. These complementary studies represent a step toward the control of this dangerous pathogen.


2016 ◽  
Vol 61 (2) ◽  
Author(s):  
Hajime Kanamori ◽  
Christian M. Parobek ◽  
Jonathan J. Juliano ◽  
David van Duin ◽  
Bruce A. Cairns ◽  
...  

ABSTRACT Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacter cloacae has been recently recognized in the United States. Whole-genome sequencing (WGS) has become a useful tool for analysis of outbreaks and for determining transmission networks of multidrug-resistant organisms in health care settings, including carbapenem-resistant Enterobacteriaceae (CRE). We experienced a prolonged outbreak of CRE E. cloacae and K. pneumoniae over a 3-year period at a large academic burn center despite rigorous infection control measures. To understand the molecular mechanisms that sustained this outbreak, we investigated the CRE outbreak isolates by using WGS. Twenty-two clinical isolates of CRE, including E. cloacae (n = 15) and K. pneumoniae (n = 7), were sequenced and analyzed genetically. WGS revealed that this outbreak, which seemed epidemiologically unlinked, was in fact genetically linked over a prolonged period. Multiple mechanisms were found to account for the ongoing outbreak of KPC-3-producing E. cloacae and K. pneumoniae. This outbreak was primarily maintained by a clonal expansion of E. cloacae sequence type 114 (ST114) with distribution of multiple resistance determinants. Plasmid and transposon analyses suggested that the majority of bla KPC-3 was transmitted via an identical Tn4401b element on part of a common plasmid. WGS analysis demonstrated complex transmission dynamics within the burn center at levels of the strain and/or plasmid in association with a transposon, highlighting the versatility of KPC-producing Enterobacteriaceae in their ability to utilize multiple modes to resistance gene propagation.


2018 ◽  
Vol 62 (10) ◽  
Author(s):  
Johanne Blais ◽  
Sara Lopez ◽  
Cindy Li ◽  
Alexey Ruzin ◽  
Srijan Ranjitkar ◽  
...  

ABSTRACTLYS228 is a novel monobactam with potent activity againstEnterobacteriaceae. LYS228 is stable to metallo-β-lactamases (MBLs) and serine carbapenemases, includingKlebsiella pneumoniaecarbapenemases (KPCs), resulting in potency against the majority of extended-spectrum β-lactamase (ESBL)-producing and carbapenem-resistantEnterobacteriaceaestrains tested. Overall, LYS228 demonstrated potent activity against 271Enterobacteriaceaestrains, including multidrug-resistant isolates. Based on MIC90values, LYS228 (MIC90, 1 μg/ml) was ≥32-fold more active against those strains than were aztreonam, ceftazidime, ceftazidime-avibactam, cefepime, and meropenem. The tigecycline MIC90was 4 μg/ml against the strains tested. AgainstEnterobacteriaceaeisolates expressing ESBLs (n= 37) or displaying carbapenem resistance (n= 77), LYS228 had MIC90values of 1 and 4 μg/ml, respectively. LYS228 exhibited potent bactericidal activity, as indicated by low minimal bactericidal concentration (MBC) to MIC ratios (MBC/MIC ratios of ≤4) against 97.4% of theEnterobacteriaceaestrains tested (264/271 strains). In time-kill studies, LYS228 consistently achieved reductions in CFU per milliliter of 3 log10units (≥99.9% killing) at concentrations ≥4× MIC forEscherichia coliandK. pneumoniaereference strains, as well as isolates encoding TEM-1, SHV-1, CTX-M-14, CTX-M-15, KPC-2, KPC-3, and NDM-1 β-lactamases.


mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Elizabeth Diago-Navarro ◽  
Michael P. Motley ◽  
Gonzalo Ruiz-Peréz ◽  
Winnie Yu ◽  
Julianne Austin ◽  
...  

ABSTRACTCarbapenem-resistant (CR) sequence type 258 (ST258)Klebsiella pneumoniaehas become an urgent health care threat, causing an increasing number of high-mortality infections. Its resistance to numerous antibiotics and threat to immunocompromised patients necessitate finding new therapies to combat these infections. Previous successes in the laboratory, as well as the conservation of capsular polysaccharide (CPS) among the members of the ST258 clone, suggest that monoclonal antibody (MAb) therapy targeting the outer polysaccharide capsule ofK. pneumoniaecould serve as a valuable treatment alternative for afflicted patients. Here, we isolated several IgG antibodies from mice inoculated with a mixture of CRK. pneumoniaeCPS conjugated to anthrax protective antigen. Two of these MAbs, 17H12 and 8F12, bind whole and oligosaccharide epitopes of the CPS of clade 2 ST258 CRK. pneumoniae, which is responsible for the most virulent CRK. pneumoniaeinfections in the United States. These antibodies were shown to agglutinate all clade 2 strains and were also shown to promote extracellular processes killing these bacteria, including biofilm inhibition, complement deposition, and deployment of neutrophil extracellular traps. Additionally, they promoted opsonophagocytosis and intracellular killing of CRK. pneumoniaeby human-derived neutrophils and cultured murine macrophages. Finally, when mice were intratracheally infected with preopsonized clade 2 CRK. pneumoniae, these MAbs reduced bacterial dissemination to organs. Our data suggest that broadly reactive anticapsular antibodies and vaccines against clade 2 ST258 CRK. pneumoniaeare possible. Such MAbs and vaccines would benefit those susceptible populations at risk of infection with this group of multidrug-resistant bacteria.IMPORTANCECarbapenem-resistantKlebsiella pneumoniaeis an enteric bacterium that has been responsible for an increasing number of deadly outbreaks and hospital-acquired infections. The pathogen’s resistance to numerous antibiotics, including new drugs, leaves few therapeutic options available for infected patients, who often are too sick to fight the infection themselves. Immunotherapy utilizing monoclonal antibodies has been successful in other medical fields, and antibodies targeting the outer polysaccharide capsule of these bacteria could be a valuable treatment alternative. This study presents two anticapsular antibodies, 17H12 and 8F12, that were found to be protective against the most virulent carbapenem-resistantK. pneumoniaeclinical strains. These antibodies are shown to promote the killing of these strains through several extracellular and intracellular processes and prevent the spread of infection in mice from the lungs to distal organs. Thus, they could ultimately treat or protect patients infected or at risk of infection by this multidrug-resistant bacterium.


2014 ◽  
Vol 59 (2) ◽  
pp. 1038-1047 ◽  
Author(s):  
Yi-Jiun Pan ◽  
Tzu-Lung Lin ◽  
Yi-Tsung Lin ◽  
Po-An Su ◽  
Chun-Tang Chen ◽  
...  

ABSTRACTKlebsiella pneumoniaeis an important human pathogen associated with a variety of diseases, and the prevalence of multidrug-resistantK. pneumoniae(MDRKP) is rapidly increasing. Here we determined the capsular types of 85 carbapenem-resistantK. pneumoniae(CRKP) strains bywzcsequencing and investigated the presence of carbapenemases and integrons among CRKP strains. Ten CRKP strains (12%) were positive for carbapenemase (imipenemase, 6/85 strains;K. pneumoniaecarbapenemase, 3/85 strains; Verona integron-encoded metallo-β-lactamase, 1/85 strains). Capsular type K64 accounted for 32 CRKP strains (38%), followed by K62 (13%), K24 (8%), KN2 (7%), and K28 (6%). Sequence types (STs) were determined by multilocus sequence typing (MLST), and the results indicated that ST11, which accounted for 47% of these CRKP strains (40/85 strains), was the major ST. We further isolated a K64-specific capsule depolymerase (K64dep), which could enhance serum and neutrophil killingin vitroand increase survival rates for K64K. pneumoniae-inoculated mice. The toxicity study demonstrated that mice treated with K64dep showed normal biochemical parameters and no significant histopathological changes of liver, kidney, and spleen, indicating that enzyme treatment did not cause toxicity in mice. Therefore, the findings of capsular type clustering among CRKP strains and effective treatment with capsule depolymerase for MDRKP infections are important for capsule-based vaccine development and therapy.


mSystems ◽  
2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Xuemei Yang ◽  
Lianwei Ye ◽  
Edward Wai-Chi Chan ◽  
Rong Zhang ◽  
Sheng Chen

ABSTRACT We recently reported the recovery of a conjugative virulence plasmid, p15WZ-82_Vir, from a clinical Klebsiella variicola strain. In this study, we found that several new plasmid types were generated due to genetic rearrangement. Partial integration of plasmid p15WZ-82_Vir with existing plasmids such as resistance plasmids by different homologous recombination events was observable in three recipient strains. Such recombination events enable the formation of various types of mosaic plasmids simultaneously carrying virulence-encoding and antibiotic resistance-encoding genes as well as genes involved in plasmid conjugation, which promote transmission of various virulence-encoding and resistance-encoding elements among pathogens. Our data also suggest that these conjugative events may play an integral role in the development of novel mosaic plasmids, which is vital for plasmid evolution. IMPORTANCE Although they are often nonconjugative, large virulence plasmids are increasingly detected in clinical K. pneumoniae and contribute to the hypervirulence phenotype of this organism. In this study, we demonstrated that the virulence-encoding region that originated from virulence plasmid pLVPK actively interacted with different types of plasmids via homologous recombination to generate new conjugative plasmids. This report provides insights into the evolution of self-transmissible plasmids carrying genetic elements encoding both hypervirulent and multidrug-resistant phenotypes, which facilitate the rapid development of clinical K. pneumoniae strains that are hypervirulent and multidrug resistant.


2018 ◽  
Vol 62 (12) ◽  
Author(s):  
Noriko Sakamoto ◽  
Yukihiro Akeda ◽  
Yo Sugawara ◽  
Dan Takeuchi ◽  
Daisuke Motooka ◽  
...  

ABSTRACT We report here Klebsiella pneumoniae strains carrying chromosomal blaNDM-1 in Thailand. The genomes of these two isolates include a 160-kbp insertion containing blaNDM-1, which is almost identical to that in the IncHI1B-like plasmid. Further analysis indicated that IS5-mediated intermolecular transposition and Tn3 transposase-mediated homologous recombination resulted in the integration of blaNDM-1 into the chromosome from an IncHI1B-like plasmid. The spread of this type of carbapenem-resistant Enterobacteriaceae may threaten public health and warrants further monitoring.


2015 ◽  
Vol 53 (9) ◽  
pp. 2861-2868 ◽  
Author(s):  
Raffaella Onori ◽  
Stefano Gaiarsa ◽  
Francesco Comandatore ◽  
Stefano Pongolini ◽  
Sylvain Brisse ◽  
...  

Multidrug-resistant (MDR)Klebsiella pneumoniaeis one of the most important causes of nosocomial infections worldwide. After the spread of strains resistant to beta-lactams at the end of the previous century, the diffusion of isolates resistant to carbapenems and colistin is now reducing treatment options and the containment of infections. Carbapenem-resistantK. pneumoniaestrains have spread rapidly among Italian hospitals, with four subclades of pandemic clonal group 258 (CG258). Here we show that a single Italian hospital has been invaded by three of these subclades within 27 months, thus replicating on a small scale the “Italian scenario.” We identified a single clone responsible for an epidemic outbreak involving seven patients, and we reconstructed its star-like pattern of diffusion within the intensive care unit. This epidemiological picture was obtained through phylogenomic analysis of 16 carbapenem-resistantK. pneumoniaeisolates collected in the hospital during a 27-month period, which were added to a database of 319 genomes representing the available global diversity ofK. pneumoniaestrains. Phenotypic and molecular assays did not reveal virulence or resistance determinants specific for the outbreak isolates. Other factors, rather than selective advantages, might have caused the outbreak. Finally, analyses allowed us to identify a major subclade of CG258 composed of strains bearing the yersiniabactin virulence factor. Our work demonstrates how the use of combined phenotypic, molecular, and whole-genome sequencing techniques can help to identify quickly and to characterize accurately the spread of MDR pathogens.


Author(s):  
Eve A. Maunders ◽  
Katherine Ganio ◽  
Andrew J. Hayes ◽  
Stephanie L. Neville ◽  
Mark R. Davies ◽  
...  

Klebsiella pneumoniae is a leading cause of healthcare-associated infections, including pneumonia, urinary tract infections, and sepsis. Treatment of K. pneumoniae infections is becoming increasingly challenging due to high levels of antibiotic resistance and the rising prevalence of carbapenem-resistant, extended-spectrum β-lactamases producing strains.


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