Transfer of carbapenem-resistant plasmid from Klebsiella pneumoniae ST258 to Escherichia coli in patient.
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ABSTRACT:
SUBMITTER: Goren MG
PROVIDER: S-EPMC3086234 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BackgroundRecent studies indicated that the monosubstituted deoxystreptamine aminoglycoside apramycin is a potent antibiotic against a wide range of MDR Gram-negative pathogens.ObjectivesTo evaluate the in vitro activity of apramycin against carbapenem-resistant Klebsiella pneumoniae (CRKp) isolates from New York and New Jersey, and to explore mechanisms of apramycin resistance.MethodsApramycin MICs were determined by broth microdilution for 155 CRKp bloodstream isolates collected from 2013 to 2018. MLST STs, wzi capsular types and apramycin resistance gene aac(3')-IV were examined by PCR and Sanger sequencing. Selected isolates were further characterized by conjugation experiments and WGS.ResultsApramycin MIC50/90 values were 8 and >128 mg/L for CRKp isolates, which are much higher than previously reported. Twenty-four isolates (15.5%) were apramycin resistant (MIC ≥64 mg/L) and they were all from the K. pneumoniae ST258 background. The 24 apramycin-resistant K. pneumoniae ST258 strains belonged to six different capsular types and 91.7% of them harboured the apramycin resistance gene aac(3')-IV. Sequencing analysis showed that different ST258 capsular type strains shared a common non-conjugative IncR plasmid, co-harbouring aac(3')-IV and blaKPC. A novel IncR and IncX3 cointegrate plasmid, p59494-RX116.1, was also identified in an ST258 strain, demonstrating how apramycin resistance can be spread from a non-conjugative plasmid through cointegration.ConclusionsWe described a high apramycin resistance rate in clinical CRKp isolates in the New York/New Jersey region, mainly among the epidemic K. pneumoniae ST258 strains. The high resistance rate in an epidemic K. pneumoniae clone raises concern regarding the further optimization and development of apramycin and apramycin-like antibiotics.
| S-EPMC8283726 | biostudies-literature
Project description:Carbapenem-resistant Klebsiella pneumoniae strains classified as multilocus sequence type 258 (ST258) are among the most widespread multidrug-resistant hospital-acquired pathogens. Treatment of infections caused by these organisms is difficult, and mortality is high. The basis for the success of ST258, outside of antibiotic resistance, remains incompletely determined. Here we tested the hypothesis that ST258K. pneumoniae has enhanced capacity to circumvent killing by human neutrophils, the primary cellular defense against bacterial infections. There was limited binding and uptake of ST258 by human neutrophils, and correspondingly, there was limited killing of bacteria. On the other hand, transmission electron microscopy revealed that any ingested organisms were degraded readily within neutrophil phagosomes, thus indicating that survival in the neutrophil assays is due to limited phagocytosis, rather than to microbicide resistance after uptake. Our findings suggest that enhancing neutrophil phagocytosis is a potential therapeutic approach for treatment of infection caused by carbapenem-resistant ST258K. pneumoniae.
| S-EPMC4837910 | biostudies-literature
Project description:A diverse, antibiotic-naive microbiota prevents highly antibiotic-resistant microbes, including carbapenem-resistant Klebsiella pneumoniae (CR-Kp), from achieving dense colonization of the intestinal lumen. Antibiotic-mediated destruction of the microbiota leads to expansion of CR-Kp in the gut, markedly increasing the risk of bacteremia in vulnerable patients. While preventing dense colonization represents a rational approach to reduce intra- and interpatient dissemination of CR-Kp, little is known about pathogen-associated factors that enable dense growth and persistence in the intestinal lumen. To identify genetic factors essential for dense colonization of the gut by CR-Kp, we constructed a highly saturated transposon mutant library with >150,000 unique mutations in an ST258 strain of CR-Kp and screened for in vitro growth and in vivo intestinal colonization in antibiotic-treated mice. Stochastic and partially reversible fluctuations in the representation of different mutations during dense colonization revealed the dynamic nature of intestinal microbial populations. We identified genes that are crucial for early and late stages of dense gut colonization and confirmed their role by testing isogenic mutants in in vivo competition assays with wild-type CR-Kp Screening of the transposon library also identified mutations that enhanced in vivo CR-Kp growth. These newly identified colonization factors may provide novel therapeutic opportunities to reduce intestinal colonization by CR-Kp IMPORTANCE Klebsiella pneumoniae is a common cause of bloodstream infections in immunocompromised and hospitalized patients, and over the last 2 decades, some strains have acquired resistance to nearly all available antibiotics, including broad-spectrum carbapenems. The U.S. Centers for Disease Control and Prevention has listed carbapenem-resistant K. pneumoniae (CR-Kp) as an urgent public health threat. Dense colonization of the intestine by CR-Kp and other antibiotic-resistant bacteria is associated with an increased risk of bacteremia. Reducing the density of gut colonization by CR-Kp is likely to reduce their transmission from patient to patient in health care facilities as well as systemic infections. How CR-Kp expands and persists in the gut lumen, however, is poorly understood. Herein, we generated a highly saturated mutant library in a multidrug-resistant K. pneumoniae strain and identified genetic factors that are associated with dense gut colonization by K. pneumoniae This study sheds light on host colonization by K. pneumoniae and identifies potential colonization factors that contribute to high-density persistence of K. pneumoniae in the intestine.
| S-EPMC6414703 | biostudies-literature
Project description:Carbapenem-resistance in Klebsiella pneumoniae (KP) sequence type ST258 is mediated by carbapenemases (e.g. KPC-2) and loss or modification of the major non-selective porins OmpK35 and OmpK36. However, the mechanism underpinning OmpK36-mediated resistance and consequences of these changes on pathogenicity remain unknown. By solving the crystal structure of a clinical ST258 OmpK36 variant we provide direct structural evidence of pore constriction, mediated by a di-amino acid (Gly115-Asp116) insertion into loop 3, restricting diffusion of both nutrients (e.g. lactose) and Carbapenems. In the presence of KPC-2 this results in a 16-fold increase in MIC to Meropenem. Additionally, the Gly-Asp insertion impairs bacterial growth in lactose-containing medium and confers a significant in vivo fitness cost in a murine model of ventilator-associated pneumonia. Our data suggests that the continuous selective pressure imposed by widespread Carbapenem utilisation in hospital settings drives the expansion of KP expressing Gly-Asp insertion mutants, despite an associated fitness cost.
| S-EPMC6718652 | biostudies-literature
Project description:Carbapenem-resistant Klebsiella pneumoniae ST258 (CRKP-ST258) are a global concern due to their rapid dissemination, high lethality, antibiotic resistance and resistance to components of the immune response, such as neutrophils. Neutrophils are major host mediators, able to kill well-studied and antibiotic-sensitive laboratory reference strains of K. pneumoniae. However, CRKP-ST258 are able to evade neutrophil phagocytic killing, persisting longer in the host despite robust neutrophil recruitment. Here, we show that neutrophils are unable to clear a CRKP-ST258 isolate (KP35). Compared to the response elicited by a prototypic K. pneumoniae ATCC 43816 (KPPR1), the neutrophil intracellular response against KP35 is characterized by equivalent production of reactive oxygen species (ROS) and myeloperoxidase content, but impaired phagosomal acidification. Our results ruled out that this phenomenon is due to a phagocytosis defect, as we observed similar efficiency of phagocytosis by neutrophils infected with KP35 or KPPR1. Genomic analysis of the cps loci of KPPR1 and KP35 suggest that the capsule composition of KP35 explain the high phagocytosis efficiency by neutrophils. Consistent with other reports, we show that KP35 did not induce DNA release by neutrophils and KPPR1 only induced it at 3 h, when most of the bacteria have already been cleared. l-arginine metabolism has been identified as an important modulator of the host immune response and positively regulate T cells, macrophages and neutrophils in response to microbes. Our data show that l-arginine supplementation improved phagosome acidification, increased ROS production and enhanced nitric oxide consumption by neutrophils in response to KP35. The enhanced intracellular response observed after l-arginine supplementation ultimately improved KP35 clearance in vitro. KP35 was able to dysregulate the intracellular microbicidal machinery of neutrophils to survive in the intracellular environment. This process, however, can be reversed after l-arginine supplementation.
| S-EPMC7691228 | biostudies-literature
Project description:Carbapenem-resistant Klebsiella pneumoniae (CRKP) strains belonging to sequence type 258 (ST258) are frequent causes of hospital-associated outbreaks and are a major contributor to the spread of carbapenemases. This genetic lineage emerged several decades ago and remains a major global health care challenge. In this study, genomic epidemiology was used to investigate the emergence, evolution, and persistence of ST258 carbapenem-resistant K. pneumoniae outbreak-causing lineages at a large tertiary care hospital over 8 years. A time-based phylogenetic analysis of 136 ST258 isolates demonstrated the succession of multiple genetically distinct ST258 sublineages over the 8-year period. Ongoing genomic surveillance identified the emergence and persistence of several distinct clonal ST258 populations. Patterns of multidrug resistance determinants and plasmid replicons were consistent with continued evolution and persistence of these populations. Five ST258 outbreaks were documented, including three that were caused by the same clonal lineage. Mutations in genes encoding effectors of biofilm production and iron acquisition were identified among persistent clones. Two emergent lineages bearing K. pneumoniae integrative conjugative element 10 (ICEKp10) and harboring yersiniabactin and colibactin virulence factors were identified. The results show how distinct ST258 subpopulations have evolved and persisted within the same hospital over nearly a decade.IMPORTANCE The carbapenem class of antibiotics is invaluable for the treatment of selected multidrug-resistant Gram-negative pathogens. The continued transmission of carbapenem-resistant bacteria such as ST258 K. pneumoniae is of serious global public health concern, as treatment options for these infections are limited. This genomic epidemiologic investigation traced the natural history of ST258 K. pneumoniae in a single health care setting over nearly a decade. We found that distinct ST258 subpopulations have caused both device-associated and ward-associated outbreaks, and some of these populations remain endemic within our hospital to the present day. The finding of virulence determinants among emergent ST258 clones supports the idea of convergent evolution of drug-resistant and virulent CRKP strains and highlights the need for continued surveillance, prevention, and control efforts to address emergent and evolving ST258 populations in the health care setting.
| S-EPMC6722418 | biostudies-literature
Project description:Klebsiella pneumoniae, an ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogen, has acquired multiple antibiotic resistance genes and is becoming a serious public health threat. Here, we report the genome sequences of two representative strains of K. pneumoniae from the emerging K. pneumoniae carbapenemase (KPC) outbreak in northeast Ohio belonging to sequence type 258 (ST258) (isolates Kb140 and Kb677, which were isolated from blood and urine, respectively). Both isolates harbor a blaKPC gene, and strain Kb140 carries blaKPC-2, while Kb677 carries blaKPC-3.
| S-EPMC4064024 | biostudies-literature
Project description:Antimicrobial resistance genes (ARG), such as extended-spectrum β-lactamase (ESBL) and carbapenemase genes, are commonly carried on plasmids. Plasmids can transmit between bacteria, disseminate globally, and cause clinically important resistance. Therefore, targeting plasmids could reduce ARG prevalence, and restore the efficacy of existing antibiotics. Cobalt complexes possess diverse biological activities, including antimicrobial and anticancer properties. However, their effect on plasmid conjugation has not been explored yet. Here, we assessed the effect of four previously characterised bis(N-picolinamido)cobalt(II) complexes lacking antibacterial activity on plasmid conjugation in Escherichia coli and Klebsiella pneumoniae. Antimicrobial susceptibility testing of these cobalt complexes confirmed the lack of antibacterial activity in E. coli and K. pneumoniae. Liquid broth and solid agar conjugation assays were used to screen the activity of the complexes on four archetypical plasmids in E. coli J53. The cobalt complexes significantly reduced the conjugation of RP4, R6K, and R388 plasmids, but not pKM101, on solid agar in E. coli J53. Owing to their promising activity, the impact of cobalt complexes was tested on the conjugation of fluorescently tagged extended-spectrum β-lactamase encoding pCTgfp plasmid in E. coli and carbapenemase encoding pKpQILgfp plasmid in K. pneumoniae, using flow cytometry. The complexes significantly reduced the conjugation of pKpQILgfp in K. pneumoniae but had no impact on pCTgfp conjugation in E. coli. The cobalt complexes did not have plasmid-curing activity, suggesting that they target conjugation rather than plasmid stability. To our knowledge, this is the first study to report reduced conjugation of clinically relevant plasmids with cobalt complexes. These cobalt complexes are not cytotoxic towards mammalian cells and are not antibacterial, therefore they could be optimised and employed as inhibitors of plasmid conjugation.
| S-EPMC10998897 | biostudies-literature
Project description:The purpose was to explore the optimal dosage regimen of colistin using Monte Carlo simulations, for the treatment of carbapenem-resistant Klebsiella pneumoniae and carbapenem-resistant Escherichia coli based on PK/PD targets in critically ill patients. A total of 116 carbapenem-resistant K. pneumoniae and E. coli were obtained from various clinical specimens at Siriraj Hospital in Bangkok, Thailand. Minimum inhibitory concentrations (MICs) of colistin were determined by broth microdilution method. Monte Carlo simulation was used to calculate the cumulative fraction of response (CFR) for European Medicine Agency (EMA), US-Food and Drug Administration (FDA), Nation et al., Siriraj Hospital and our study regimens. The targeted CFR was 90%. For colistin-susceptible K. pneumoniae, all of the dosage regimens achieved ?90% CFR in patients with creatinine clearance <80 mL/min except the FDA-approved regimens for patients with creatinine clearance 51-79 and 11-29 mL/min, respectively. While, patients with creatinine clearance ?80 mL/min, CFR ?90% was observed in Siriraj Hospital and our study regimen. For colistin-susceptible E. coli, all of the dosage regimens achieved ?90% CFR regardless of renal function. In contrast, the currently approved regimens achieved CFR target in only 10-50% for colistin-resistant isolates subgroup. These results suggest that currently approved regimens still recommended for colistin-susceptible CRE. For colistin-resistant CRE, alternative approaches such as high dose or combination therapy should be considered.
| S-EPMC6784242 | biostudies-literature
Project description:Here we describe the spread of colistin resistance in clinical isolates of carbapenem-resistant Klebsiella pneumoniae in Medellín, Colombia. Among 32 isolates collected between 2012 and 2014, 24 showed genetic alterations in mgrB Nineteen isolates belonged to sequence type 512 (ST512) (or its single locus variant [SLV]) and harbored an 8.1-kb hsdMSR insertion corresponding to ISKpn25, indicating a clonal expansion of the resistant strain. The insertion region showed 100% identity to several plasmids, suggesting that the colistin resistance is mediated by chromosomal integration of plasmid DNA.
| S-EPMC5527652 | biostudies-literature