Carbapenemase-producing Klebsiella Research Articles

The Increased Prevalence of rmpA Gene in Klebsiella pneumoniae Isolates Coharboring blaNDM and blaOXA-48-like Genes.

The emergence of carbapenemase-producing Klebsiella pneumoniae poses a substantial risk to public health. It is essential to comprehend the influence of carbapenemase on the virulence characteristics of K. pneumoniae in order to devise successful strategies for combating these infections. In this study, we explored the distribution disparity of virulence determinants between carbapenemase-producing (CP-Kp, n = 52) and carbapenemase-nonproducing (CN-Kp, n = 43) isolates. The presence of carbapenemases was detected via the modified carbapenem inactivation method and confirmed by PCR. The New Delhi metallo-β-lactamase (blaNDM) and Oxacillinase-48-like (blaOXA-48-like) genes were the most prevalent (94.23% and 76.92%, respectively) in CP-Kp isolates. Coexistence of blaNDM and blaOXA-48-like was observed in 71.15% of isolates, whereas 5.77% coharbored blaNDM and blaKPC. PCR analysis revealed the presence of several virulence genes, including adhesins (fimH, 92.63%, mrkD, 97.89%), capsule-associated virulence (uge, 90.53%), the K2 capsule serotype (k2, 6.32%), the iron acquisition system (kfu, 23.16%), and the regulator of mucoid phenotype (rmpA, 28.42%). A significantly higher prevalence of rmpA was detected in the CP-Kp compared with the CN-Kp (24/52 vs. 3/43, p < 0.0001), indicating a potential association between rmpA and carbapenemase acquisition. In addition, the majority of rmpA (22/24) positive isolates in the CP-Kp isolates coharbored blaNDM and either blaOXA-48-like or blaKPC.

Epidemiological and clinical characterization of community, healthcare-associated and nosocomial colonization and infection due to carbapenemase-producing Klebsiella pneumoniae and Escherichia coli in Spain.

Community-acquired (CA) and healthcare-associated (HCA) infections caused by carbapenemase-producing Enterobacterales (CPE) are not well characterized. The objective was to provide detailed information about the clinical and molecular epidemiological features of nosocomial, HCA and CA infections caused by carbapenemase-producing Klebsiella pneumoniae (CP-Kp) and Escherichia coli (CP-Ec). A prospective cohort study was performed in 59 Spanish hospitals from February to March 2019, including the first 10 consecutive patients from whom CP-Kp or CP-Ec were isolated. Patients were stratified according to acquisition type. A multivariate analysis was performed to identify the impact of acquisition type in 30-day mortality. Overall, 386 patients were included (363 [94%] with CP-Kp and 23 [6%] CP-Ec); in 296 patients (76.3%), the CPE was causing an infection. Acquisition was CA in 31 (8.0%) patients, HCA in 183 (47.4%) and nosocomial in 172 (48.3%). Among patients with a HCA acquisition, 100 (54.6%) had been previously admitted to hospital and 71 (38.8%) were nursing home residents. Urinary tract infections accounted for 19/23 (82.6%), 89/130 (68.5%) and 42/143 (29.4%) of CA, HCA and nosocomial infections, respectively. Overall, 68 infections (23%) were bacteremia (8.7%, 17.7% and 30.1% of CA, HCA and nosocomial, respectively). Mortality in infections was 28% (13%, 14.6% and 42.7% of CA, HCA and nosocomial, respectively). Nosocomial bloodstream infections were associated with increased odds for mortality (adjusted OR, 4.00; 95%CI 1.21-13.19). HCA and CA infections caused by CPE are frequent and clinically significant. This information may be useful for a better understanding of the epidemiology of CPE.

Genomic characterization of carbapenemase-producing Klebsiella pneumoniae ST307 revealed multiple introductions in Buenos Aires, Argentina

Objective: to describe at genomic level nine carbapenemase-producing Klebsiella pneumoniae ST307 (Kp-ST307) clinical isolates recovered in Buenos Aires during 2017-2021, investigating their resistome, virulome and phylogeny.Methods: Antimicrobial susceptibility was determined according to CLSI. Genomic DNA was sequenced by Illumina MiSeq and analyzed using SPAdes, PROKKA and Kleborate. Phylogeny of 355 randomly selected Kp-ST307 genomes and those from nine local isolates was inferred by a maximum-likelihood approach. The tree was visualized using Microreact.Results: Besides resistance to ß-lactams and fluoroquinolones, six out of nine Kp-ST307 were also resistant to ceftazidime/avibactam (CZA). This difficult-to-treat resistance phenotype was mediated by blaSHV-28 and gyrA-83I/parC-80I mutations in addition to carbapenemase coding genes. Among CZA susceptible isolates, two of them harbored blaKPC-3 while the other harbored blaKPC-2+blaCTX-M-15. Respect to CZA resistant isolates, three harbored blaKPC-3+blaNDM-1+blaCMY-6, two carried blaKPC-2+blaNDM-5+blaCTX-M-15, and blaNDM-5+blaCTX-M-15 were detected in the remaining isolate. Besides, five colistin resistant isolates presented a nonsense mutation in mgrB.Global Kp-ST307 isolates were distributed in two deep-branching lineages while local isolates set in the main clade of the phylogenetic tree. The five isolates from a same hospital, harboring blaKPC-3 or blaKPC-3+blaNDM-1+blaCMY-6, clustered in a monophyletic subclade with Italian isolates. Also, an isolate harboring blaKPC-2+blaNDM-5+blaCTX-M-15 recovered in another hospital was closed to this group. The remaining local Kp-ST307 grouped in other subclades containing isolates of diverse geographically origin.Conclusion: The inferred resistome was consistent with the resistant phenotype. Phylogeny suggested multiple introduction events in our region and a single major introduction in one hospital followed by local spread.

High Prevalence of Carbapenem-Resistant Enterobacterales Producing OXA-48 among Carbapenem-Resistant Isolates in a Regional Hospital in Central Taiwan.

In response to the increasing number of carbapenem-resistant Enterobacterales (CRE), we investigated carbapenemase-producing Klebsiella pneumoniae and non-K. pneumoniae epidemiology and genetics. We collected 76 clinical Enterobacterales and 4 stool surveillance Escherichia coli isolates resistant to ertapenem or imipenem. Using polymerase chain reaction (PCR) and DNA sequencing, we assessed carbapenemases, extended-spectrum β-lactamases, and AmpC β-lactamases. Molecular typing via pulsed-field gel electrophoresis (PFGE) and conjugation experiments were conducted to examine resistance gene transfer. Among the 80 isolates, 96.2% harbored at least one carbapenemase gene, with blaOXA-48 in 87.5%. KPC-2 and IMP-8 carbapenemases were found in 15.0 and 22.5% of the isolates, respectively, with 27.5% having 2 or more carbapenemase genes. The PFGE analysis revealed the presence of diverse genotypes. PCR-based plasmid replicon typing identified IncA/C as the most prevalent type among K. pneumoniae isolates (26/29), and IncF and IncFIB among E. coli isolates (22/28). Conjugal transfer was successful for plasmids encoding OXA-48, CTX-M-3, CTX-M-14, CMY-2, and other β-lactamases, except the KPC-2 gene. In conclusion, our study highlights high carbapenemase prevalence in CRE, primarily OXA-48. Multiple carbapenemases within strains were common, and PFGE showed diverse patterns in these carbapenem-resistant isolates.

Evaluation of the synergistic effect of eravacycline and tigecycline against carbapenemase-producing carbapenem-resistant Klebsiella pneumoniae

BackgroundCarbapenem-resistant Klebsiella pneumoniae (CRKP) poses a substantial healthcare challenge. This study assessed the in vitro efficacy of selected antibiotic combinations against CRKP infections. MethodsOur research involved the evaluation of 40 clinical isolates of CRKP, with half expressing Klebsiella pneumoniae carbapenemase (KPC) and half producing Metallo-β-lactamase (MBL), two key enzymes contributing to carbapenem resistance. We determined the minimum inhibitory concentrations (MICs) of four antibiotics: eravacycline, tigecycline, polymyxin-B, and ceftazidime/avibactam. Synergistic interactions between these antibiotic combinations were examined using checkerboard and time-kill analyses. ResultsWe noted significant differences in the MICs of ceftazidime/avibactam between KPC and MBL isolates. Checkerboard analysis revealed appreciable synergy between combinations of tigecycline (35%) or eravacycline (40%) with polymyxin-B. The synergy rates for the combination of tigecycline or eravacycline with polymyxin-B were similar among the KPC and MBL isolates. These combinations maintained a synergy rate of 70.6% even against polymyxin-B resistant isolates. In contrast, combinations of tigecycline (5%) or eravacycline (10%) with ceftazidime/avibactam showed significantly lower synergy than combinations with polymyxin-B (P < 0.001 and P = 0.002, respectively). Among the MBL CRKP isolates, only one exhibited synergy with eravacycline or tigecycline and ceftazidime/avibactam combinations, and no synergistic activity was identified in the time-kill analysis for these combinations. The combination of eravacycline and polymyxin-B demonstrated the most promising synergy in the time-kill analysis. ConclusionThis study provides substantial evidence of a significant synergy when combining tigecycline or eravacycline with polymyxin-B against CRKP strains, including those producing MBL. These results highlight potential therapeutic strategies against CRKP infections.

In vitro activity, pharmacodynamic profile and dose optimization of biapenem against NDM and OXA-48-like carbapenemase-producing Klebsiella pneumoniae: A multicentre study in Thailand

Biapenem (BIPM) exhibited a less efficient substrate for various metallo-β-lactamase (MBL) than other carbapenems. We aimed to evaluate in vitro susceptibility data of BIPM and optimal dose based on Monte Carlo simulation to extend treatment options. We collected 192 carbapenem-resistant Klebsiella pneumoniae (CRKP) clinical isolates from unique patients among multicentres in Thailand, from June 2019 to March 2023. BIPM disk diffusion and broth-microdilution testing were performed to obtain minimum inhibitory concentration (MIC). Each BIPM regimen was simulated using the Monte Carlo technique to calculate the probability of target attainment (PTA) and the cumulative fraction of response (CFR). The most common genotypes among 192 CRKP isolates were blaOXA-48 (62.3%), blaOXA-48+blaNDM (22.6%) and blaNDM (15.1%). BIPM showed 22.4 and 28.6% susceptible rate when interpreted at clinical breakpoints of 1 and 2 mg/L. The MIC50 and MIC90 of BIPM against CRKP were 8 and 32 mg/L. The BIPM dosing regimens of 300 mg q 6 h infused 6 h and 600 mg q 8 h infused 8 h met the PTA target of %fTime >MIC at 50%, 75% and 100% against isolates MICs of ≤2 mg/L. Based on CFR ≥90%, no BIPM regimens were effective against all the studied CRKP isolates. BIPM exhibited a partially susceptible rate among the CRKP isolates in Thailand. The current suggested dose of BIPM with prolonged infusion appears appropriate regimen against CRKP MICs of ≤2 mg/L. However, the empirical use of BIPM for severe CRE infection is not recommended unless the susceptibility has been confirmed.

Evaluation of temocillin efficacy against KPC-2-producing Klebsiella pneumoniae isolates in a hollow-fibre infection model.

Temocillin is an old antimicrobial that is resistant to hydrolysis by ESBLs but has variable activity against carbapenemase-producing Enterobacteriaceae. The current EUCAST susceptibility breakpoints for Enterobacterales are set at ≤16 mg/L (susceptible with increased exposure) based on a dose of 2 g q8h, but there is limited information on the efficacy of this dose against temocillin-susceptible carbapenemase-producing Klebsiella pneumoniae isolates. To evaluate the efficacy of this dose using a hollow-fibre infection model (HFIM) against six KPC-2-producing clinical isolates of K. pneumoniae. The isolates were characterized by WGS and temocillin susceptibility was determined using standard and high inoculum temocillin. Mutant frequencies were estimated and temocillin activity was tested in time-kill assays and in the HFIM. At standard conditions, three of the isolates were classified as susceptible (MIC ≤ 16 mg/L) and three as resistant (MIC > 16 mg/L). The HFIM was performed over 3 days to mimic human-like pharmacokinetics of 2 g q8h. Bacterial counts were performed by plating on Mueller-Hinton agar (MHA) and MHA containing 64 mg/L temocillin to detect resistant subpopulations. All isolates showed a reduction in bacterial population of at least 3 log cfu/mL within the first 8 h of simulated treatment in the hollow-fibre assay. Regrowth was observed for the three resistant isolates and one of the susceptible ones. The MIC value for these isolates was higher by at least two dilutions compared with their initial values. These data suggest that an optimized pharmacokinetic regimen may be of clinical interest for the treatment of KPC-2-producing K. pneumoniae susceptible to temocillin. These data showed activity of temocillin against KPC-2-producing K. pneumoniae susceptible to temocillin; however, a dose of 2g q8h administered over 30 min may be inadequate to prevent the emergence of resistant variants.

Phenotypic and Molecular Detection of Carbapenemase-Producing Klebsiella pneumoniae Isolated from Patients Admitted to Teaching Hospitals in Shiraz, Iran

Background: Carbapenem-resistant Klebsiella pneumoniae (Cr-KPN) poses a significant global public health challenge. Objectives: This study aimed to investigate the prevalence and expression levels of carbapenemase-encoding genes in Cr-KPN isolated from patients admitted to teaching hospitals in Shiraz, Iran. Methods: A total of 671 distinct clinical samples were collected from two teaching hospitals in Shiraz. Initial identification and final confirmation of K. pneumoniae isolates were carried out using conventional biochemical tests and PCR assays, respectively. The detection of carbapenemase-producing K. pneumoniae, both phenotypically and genotypically, was performed through modified carbapenem inactivation methods (mCIM) and multiplex PCR assays. Real-time PCR was utilized to assess the expression levels of carbapenemase-encoding genes. Results: The overall frequency of K. pneumoniae strains was 14.9% (n = 100/671). mCIM indicated that 26% of K. pneumoniae isolates exhibited carbapenemase production. Furthermore, 24% and 17% of K. pneumoniae isolates demonstrated resistance to imipenem and meropenem, respectively. The blaIMI/IMP gene was detected in 91% of the isolates. Among imipenem-resistant isolates, 62.5% tested positive for the blaOXA-48 gene. Additionally, 29.4%, 76.5%, and 11.8% of meropenem-resistant isolates were positive for the blaKPC, blaOXA-48, and blaNDM genes, respectively. Real-time PCR analysis revealed increased expression levels of blaKPC (1.66-fold), blaOXA-48 (7.30-fold), blaNDM (4.22-fold), and blaIMI/NMC (2.39-fold) genes in resistant isolates when exposed to imipenem. Conclusions: These findings underscore the significance of establishing active surveillance networks to monitor and track the dissemination of carbapenemase-producing K. pneumoniae, which presents a global public health threat.

Carbapenemase-Producing Klebsiella pneumoniae Infections in Diabetic and Nondiabetic Hospitalized Patients.

Carbapenem-resistant Klebsiella pneumoniae (CRKP) infection has recently attracted widespread attention due to its limited treatment options and significant morbidity and mortality rates. This study aimed to examine the relationship between risk factors and antimicrobial resistance in individuals with and without diabetes for the development of carbapenemase-producing K. pneumoniae infections. Between May 2019 and January 2021, a prospective study involving patients with and without diabetes who were infected with K. pneumonia, was carried out in a tertiary care hospital. Six hundred K. pneumoniae isolates were collected from various clinical samples, such as pus/wound samples, urine, respiratory samples, blood, and body fluids. An antimicrobial susceptibility test in K. pneumoniae was performed and compared between diabetics and nondiabetics. Univariate and multivariate logistic regression were used to identify independent risk factors for K. pneumoniae infections in the diabetic group and nondiabetic group separately. Multiplex PCR was used to detect genes that produce carbapenemase. A total of 600 patients were infected with K. pneumoniae, with 300 (50%) being diabetic and 300 (50%) being nondiabetic. We found that diabetics had higher antimicrobial resistance to numerous routinely used drugs for infection than the nondiabetic group. In the multivariate analysis of the variables, it was found that immunosuppressive therapy, prior antibiotic use, mechanical ventilation, and urinary catheter use were all significant risk factors influencing the development of K. pneumoniae infections in diabetic patients. Diabetics had a higher prevalence of carbapenemase-producing K. pneumoniae than nondiabetics. Outcome measures in K. pneumoniae patients revealed that the diabetic group had considerably higher infection-related mortality. We found that CRKP infection was associated with higher resistance to antibiotics in the diabetic group. Furthermore, the diabetic group had a higher prevalence of carbapenemase-producing K. pneumoniae than the nondiabetic group. Crucially, in order to lower mortality without worsening antibiotic resistance and metabolic damage, more focus has to be placed on sensible and efficient antibiotic and supportive care therapies.

Molecular characteristics, fitness, and virulence of high-risk and non-high-risk clones of carbapenemase-producing Klebsiella pneumoniae.

Extensively drug-resistant (XDR) Klebsiella pneumoniae inflict a notable burden on healthcare worldwide. Of specific concern are strains producing carbapenem-hydrolyzing enzymes, as the therapeutic options for these strains are still very limited. Specific sequence types of K. pneumoniae have been noted for their epidemic occurrence globally, but the mechanisms behind the success of specific clones remain unclear. Herein, we have characterized 20 high-risk clones (HiRCs) and 10 non-HiRCs of XDR K. pneumoniae, exploring factors connected to the epidemiological success of some clones. Isolates were subjected to core genome multilocus sequence typing analysis to determine the clonal relationships of the isolates and subsequently characterized with regard to features known to be linked to overall bacterial fitness and virulence. The genomes were analyzed in silico for capsule types, O antigens, virulence factors, antimicrobial resistance genes, prophages, and CRISPR-Cas loci. In vitro growth experiments were conducted to retrieve proxies for absolute and relative fitness for 11 HiRC and 9 non-HiRC isolates selected based on the clonal groups they belonged to, and infections in a Galleria mellonella insect model were used to evaluate the virulence of the isolates in vivo. This study did not find evidence that virulence factors, prophages, CRISPR-Cas loci, or fitness measured in vitro alone would contribute to the global epidemiological success of specific clones of carbapenemase-producing XDR K. pneumoniae. However, this study did find the HiRC group to be more virulent than the non-HiRC group when measured in vivo in a model with G. mellonella. This suggests that the virulence and epidemiological success of certain clones of K. pneumoniae cannot be explained by individual traits investigated in this study and thus warrant further experiments in the future.IMPORTANCEHerein, we explored potential explanations for the successfulness of some epidemic or high-risk clones of carbapenemase-producing Klebsiella pneumoniae. We found differences in mortality in a larva model but found no clear genomic differences in known virulence markers. Most of the research on virulence in K. pneumoniae has been focused on hypervirulent strains, but here, we try to understand differences within the group of highly resistant strains. The results from the larva virulence model could be used to design experiments in higher animals. Moreover, the data could provide further support to a differentiated infection control approach against extensively drug-resistant strains, based on their classification as high-risk clones.

Genomic features of resistant &lt;i&gt;Klebsiella pneumonia&lt;/i&gt;, isolated from the bloodstream and cerebrospinal fluid of pediatric hospital patients

Introduction. Carbapenemase-producing Klebsiella pneumoniae (CP-Kp), which are international high-risk clones, have become a problem of utmost importance. CP-Kps, adapting to the hospital environment, evolve into convergent pathotypes. Such variants combine traits of two genetic lineages: multidrug resistant (MDR) and hypervirulent. The pathotypes, along with MDR K. pneumoniae, pose an exceptional threat to young patients during systemic infection.&#x0D; The objective of this study is the detailed molecular genetic analysis of MDR isolates of K. pneumoniae detected during the monitoring of resistant Gram-negative bacteria at the National Medical Research Center for Children’s Health in 2014–2021.&#x0D; Materials and methods. Whole-genome sequencing with a subsequent bioinformatics analysis of eight MDR isolates from the bloodstream and cerebrospinal fluid.&#x0D; Results. MDR isolates belonged to 4 sublineages (SL): SL307, SL395, SL29 and SL1198. In the genomes of 6 pangrug-resistant (PDR) isolates, genes associated with resistance to all categories of antibiotics recommended for Enterobacteriaceae therapy were identified. Plasmids were present in all genomes. In 6 isolates, plasmids contained heavy metal ion resistance operons in addition to antibiotic resistance genes. Prophages within the plasmids were also involved in the transfer of resistance genes. The ST395 isolate from the cerebrospinal fluid belonged to the convergent pathotype in terms of resistance and virulence. Comparison of genomes within SLs revealed recombination events in the K- and O-locus regions and the Yersiniabactin operon.&#x0D; Conclusion. Thus, in a sample of resistant K. pneumoniae isolated from bloodstream and cerebrospinal fluid, 6 PDR isolates were detected, one of which belongs to the convergent pathotype ST395.

Usefulness of inclusion of ertapenem and temocillin screening breakpoints in the EUCAST rapid antimicrobial susceptibility testing (RAST) for rapid detection of OXA-48-producing Klebsiella pneumoniae directly from positive blood cultures.

The aims of this study were: (i) to assess the ability of the meropenem screening breakpoint as part of the screening rapid antimicrobial susceptibility testing (sRAST) of EUCAST for the detection of OXA-48 carbapenemase-producing Klebsiella pneumoniae directly from positive blood cultures (BCs); and (ii) to evaluate the inclusion of ertapenem and temocillin discs into the sRAST to enhance the detection of OXA-48-producing isolates. BC bottles were spiked with a total of 117 K. pneumoniae isolates, including 77 previously characterized OXA-48 producers and 40 non-OXA-48 producers. Disc diffusion assays were directly performed from positive BCs with meropenem (10 µg), ertapenem (10 µg) and temocillin (30 µg) discs, and inhibition zones were manually measured after 4, 6 and 8 h of incubation. The screening cut-off values of sRAST were applied to evaluate their capability in detecting OXA-48-producing isolates. Receiver operating characteristic curves were constructed to illustrate the performance efficacy of the disc diffusion assays to detect OXA-48 producers. The meropenem cut-off values of sRAST only detected 90.91% of the OXA-48-producing isolates after 6 and 8 h of incubation. With the proposed cut-off points for ertapenem [<19 mm (4/6 h) and <20 mm (8 h)] and temocillin [<10 mm (4 h) and <11 mm (6/8 h)], all OXA-48-positive isolates were detected without any false-positive results at any reading time. In healthcare settings with a high prevalence of OXA-48 producers, the inclusion of ertapenem and temocillin discs in the sRAST procedure may improve the detection of OXA-48-producing K. pneumoniae isolates directly from positive BCs, providing reliable results after only a 4 h incubation period.

Pharmacodynamics of Doripenem Alone and in Combination with Relebactam in an In Vitro Hollow-Fiber Dynamic Model: Emergence of Resistance of Carbapenemase-Producing Klebsiella pneumoniae and the Inoculum Effect.

The emergence of bacteria resistant to beta-lactam/beta-lactamase inhibitor combinations is insufficiently studied, wherein the role of the inoculum effect (IE) in decreased efficacy is unclear. To address these issues, 5-day treatments with doripenem and doripenem/relebactam combination at different ratios of the agents were simulated in a hollow-fiber dynamic model against carbapenemase-producing K. pneumoniae at standard and high inocula. Minimal inhibitory concentrations (MICs) of doripenem alone and in the presence of relebactam at two inocula were determined. Combination MICs were tested using traditional (fixed relebactam concentration) and pharmacokinetic-based approach (fixed doripenem-to-relebactam concentration ratio equal to the therapeutic 24-h area under the concentration-time curve (AUC) ratio). In all experiments, resistant subpopulations were noted, but combined simulations reduced their numbers. With doripenem, the IE was apparent for both K. pneumoniae isolates in combined treatments for one strain. The pharmacokinetic-based approach to combination MIC estimation compared to traditional showed stronger correlation between DOSE/MIC and emergence of resistance. These results support (1) the constraint of relebactam combined with doripenem against the emergence of resistance and IE; (2) the applicability of a pharmacokinetic-based approach to estimate carbapenem MICs in the presence of an inhibitor to predict the IE and to describe the patterns of resistance occurrence.

ANCA: artificial nucleic acid circuit with argonaute protein for one-step isothermal detection of antibiotic-resistant bacteria

Endonucleases have recently widely used in molecular diagnostics. Here, we report a strategy to exploit the properties of Argonaute (Ago) proteins for molecular diagnostics by introducing an artificial nucleic acid circuit with Ago protein (ANCA) method. The ANCA is designed to perform a continuous autocatalytic reaction through cross-catalytic cleavage of the Ago protein, enabling one-step, amplification-free, and isothermal DNA detection. Using the ANCA method, carbapenemase-producing Klebsiella pneumoniae (CPKP) are successfully detected without DNA extraction and amplification steps. In addition, we demonstrate the detection of carbapenem-resistant bacteria in human urine and blood samples using the method. We also demonstrate the direct identification of CPKP swabbed from surfaces using the ANCA method in conjunction with a three-dimensional nanopillar structure. Finally, the ANCA method is applied to detect CPKP in rectal swab specimens from infected patients, achieving sensitivity and specificity of 100% and 100%, respectively. The developed method can contribute to simple, rapid and accurate diagnosis of CPKP, which can help prevent nosocomial infections.

Corrigendum: CARB-ES-19 multicenter study of carbapenemase-producing Klebsiella pneumoniae and Escherichia coli from all Spanish provinces reveals interregional spread of high-risk clones such as ST307/OXA-48 and ST512/KPC-3

Corrigendum: CARB-ES-19 multicenter study of carbapenemase-producing Klebsiella pneumoniae and Escherichia coli from all Spanish provinces reveals interregional spread of high-risk clones such as ST307/OXA-48 and ST512/KPC-3

Emergence and persistent spread of carbapenemase-producing Klebsiella pneumoniae high-risk clones in Greek hospitals, 2013 to 2022.

BackgroundPreliminary unpublished results of the survey of carbapenem- and/or colistin-resistant Enterobacterales (CCRE survey) showed the expansion of carbapenemase-producing Klebsiella pneumoniae (CPKP) sequence type (ST) 39 in 12 of 15 participating Greek hospitals in 2019.AimWe conducted a rapid survey to determine the extent of spread of CPKP high-risk clones in Greek hospitals in 2022 and compare the distribution of circulating CPKP clones in these hospitals since 2013.MethodsWe analysed whole genome sequences and epidemiological data of 310 K. pneumoniae isolates that were carbapenem-resistant or 'susceptible, increased exposure' from Greek hospitals that participated in the European survey of carbapenemase-producing Enterobacteriaceae (EuSCAPE, 2013-2014), in the CCRE survey (2019) and in a national follow-up survey (2022) including, for the latter, an estimation of transmission events.ResultsFive K. pneumoniae STs including ST258/512 (n = 101 isolates), ST11 (n = 93), ST39 (n = 56), ST147 (n = 21) and ST323 (n = 13) accounted for more than 90% of CPKP isolates in the dataset. While ST11, ST147 and ST258/512 have been detected in participating hospitals since 2013 and 2014, KPC-2-producing ST39 and ST323 emerged in 2019 and 2022, respectively. Based on the defined genetic relatedness cut-off, 44 within-hospital transmission events were identified in the 2022 survey dataset, with 12 of 15 participating hospitals having at least one within-hospital transmission event.ConclusionThe recent emergence and rapid spread of new high-risk K. pneumoniae clones in the Greek healthcare system related to within-hospital transmission is of concern and highlights the need for molecular surveillance and enhanced infection prevention and control measures.

Prevalence and mortality of ceftazidime/avibactam-resistant KPC-producing Klebsiella pneumoniae bloodstream infections (2018–2022)

IntroductionCeftazidime/avibactam-resistance in Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae (KPC-Kp) is a topic of great interest for epidemiological, diagnostic, and therapeutical reasons. However, data on its prevalence and burden on mortality in patients with bloodstream infection (BSI) are lacking. This study was aimed at identifying risk factors for mortality in patients suffering from ceftazidime/avibactam-resistant KPC-Kp BSI.MethodsAn observational retrospective study (January 2018–December 2022) was conducted at a tertiary hospital including all consecutive hospitalized adult patients with a ceftazidime/avibactam-resistant KPC-Kp BSI. Data on baseline clinical features, management, and admission outcomes were analyzed.ResultsOver the study period, among all the KPC-Kp BSI events recorded, 38 (10.5%) were caused by ceftazidime/avibactam-resistant KPC-Kp strains, 37 events being finally included. The ceftazidime/avibactam-resistant KPC-Kp strains revealed susceptibility restoration to at least one carbapenem in more than 60% of cases. In-hospital and 30-day all-cause mortality rates were 22% and 16.2%, respectively. Non-survivors suffered from more baseline comorbidities and experienced a more severe ceftazidime/avibactam-resistant KPC-Kp BSI presentation (i.e., both the Pitt Bacteremia and INCREMENT-CPE scores were significantly higher). Presenting with a higher Charlson Comorbidity Index, chronic kidney disease—KDIGO stage 3A or worse—having recently gone through renal replacement therapy, having suffered from an acute kidney injury following the ceftazidime/avibactam-resistant KPC-Kp BSI, and being admitted for cardiac surgery were the strongest predictors of mortality.ConclusionCeftazidime/avibactam resistance in KPC-Kp BSI easily emerged in our highly KPC-Kp endemic area with remarkable mortality rates. Our findings might provide physicians possibly actionable information when managing patients with a ceftazidime/avibactam-resistant KPC-Kp BSI.

Whole genome structure and resistance genes in carbapenemase-producing multidrug resistant ST378 Klebsiella pneumoniae

Background Carbapenemase-producing Klebsiella pneumoniae (CPKP) is one of the most dangerous multidrug-resistant (MDR) pathogens in human health due to its widespread circulation in the nosocomial environment. CPKP carried by companion dogs, which are close to human beings, should be considered a common threat to public health. However, CPKP dissemination through companion animals is still under consideration of major diagnosis and surveillance systems.MethodsTwo CPKP isolates which were genotyped to harbor blaNDM-5-encoding IncX3 plasmids, were subjected to the whole-genome study. Whole bacterial DNA was isolated, sequenced, and assembled with Oxford Nanopore long reads and corrected with short reads from the Illumina NovaSeq 6000 platform. The whole-genome structure and positions of antimicrobial resistance (AMR) genes were identified and visualized using CGView. Worldwide datasets were downloaded from the NCBI GenBank database for whole-genome comparative analysis. The whole-genome phylogenetic analysis was constructed using the identified whole-chromosome SNP sites from K. pneumoniae HS11286.ResultsAs a result of the whole-genome identification, 4 heterogenous plasmids and a single chromosome were identified, each carrying various AMR genes. Multiple novel structures were identified from the AMR genes, coupled with mobile gene elements (MGE). The comparative whole-genome epidemiology revealed that ST378 K. pneumoniae is a novel type of CPKP, carrying a higher prevalence of AMR genes.ConclusionsThe characterized whole-genome analysis of this study shows the emergence of a novel type of CPKP strain carrying various AMR genes with variated genomic structures. The presented data in this study show the necessity to develop additional surveillance programs and control measures for a novel type of CPKP strain.

Prevalence and molecular determinants of carbapenemase-producing Klebsiella pneumoniae isolated from Jazan, Saudi Arabia

Introduction: The World Health Organization (WHO) designated Carbapenem-resistant Enterobacterales (CRE), formerly Enterobacteriaceae, among the global priority list of antibiotic-resistant bacteria. The rate of CRE in Arabian countries, including Saudi Arabia has increased. Here, we report the prevalence of carbapenemase-producing Klebsiella pneumoniae (CPKP) in the Jazan region, a southern coastal province of Saudi Arabia. Methodology: Eighty-six non-repetitive clinical isolates of K. pneumoniae that showed resistance to at least one of the carbapenem drugs were collected from three tertiary hospitals in the Jazan region from March 2020 to April 2021. The identification and antimicrobial susceptibility testing (AST) of isolates were performed using various automated systems. Molecular detection of carbapenemase genes was conducted using a multiplex PCR. Results: Out of the 86 tested CRKP isolates, 64 (74.4%) were carbapenemase-producing isolates. The blaOXA-48 gene was the most predominant carbapenemase gene, detected in 65.1% (n = 56) of isolates. The blaNDM gene was detected in only 9.3% (n = 8) of isolates; three were found to be co-harbored with blaVIM. Interestingly, one isolate of CRKP was found to have carbapenemase genes (blaNDM, blaVIM and blaKPC), which was associated with COVID-19 patient. Conclusions: The incidence of carbapenemase-producing K. pneumoniae in Jazan hospitals seemed to be high, confirming the continued prevalence of carbapenem resistance in Saudi Hospitals. We report K. pneumoniae strain with triple carbapenemase genes in southern Saudi Arabia. The emergence of such an isolate could threaten patients and healthcare workers and requires great attention to rapid interventions to avoid further dissemination, particularly during the COVID-19 pandemic.

Prevalence of carbapenemase producing Enterobacterales colonization and risk factor of clinical infection

BackgroundCarbapenemase-producing Enterobacterales (CPE) are global concerns in infection control, and the number of CPE outbreaks in hospitals is increasing despite the strengthening of contact precautions. This study aimed to confirm the prevalence and transition rate of CPE infection from stool surveillance culture and to identify the acquisition pathway of CPE. MethodsThis is a longitudinal review of patients with stool surveillance cultures at a tertiary center in Seoul, South Korea, from July 2018 to June 2020. Pulsed-field gel electrophoresis, multi-locus sequence typing, and whole genome sequencing were performed for carbapenemase-producing Klebsiella pneumoniae and Escherichia coli strains. ResultsAmong 1620 patients who had undergone stool CPE surveillance cultures, only 7.1% of active surveillance at the Emergency Room (ER) and 4.4% of universal surveillance in the Intensive Care Unit (ICU) were stool CPE positive. The transition rates from stool carriers to clinical CPE infections were 29.4% in the ER and 31.3% in the ICU. However, it was significantly high (55.0%) in the initial stool CPE-negative ICU patients. Among the initial stool CPE-positive patients, hypertension (61% vs. 92.3%, P = 0.004), malignancy (28.8% vs. 53.8%, P = 0.027), and mechanical ventilation (25.4% vs. 53.8%, P = 0.011) were significant risk factors for clinical CPE infection. Molecular typing revealed that sequence type (ST) 307 and ST 395 were dominant in K. pneumoniae, and ST 410 was dominant in E. coli isolates. ConclusionsActive surveillance showed a higher detection rate than universal stool CPE screening, and one-third of positive stool CPE specimens ultimately developed subsquent clinical CPE infection. According to the molecular typing of the identified CPE strains, in-hospital spread prevailed over external inflow, and the transition rate to clinical CPE was particularly high in the ICU. Therefore, in order to control CPE propagation, not only active surveillance to block inflow from outside, but also continuous ICU monitoring within the hospital is necessary.