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We aimed to clarify the epidemiologic and clinical importance of evolutionary events that occurred in carbapenem-resistant Klebsiella pneumoniae (CRKP). We collected 203 CRKP causing bloodstream infections in a tertiary hospital in China during 2013-2017. We detected a subclonal shift in the dominant clone sequence type (ST) 11 CRKP in which the previously prevalent capsular loci (KL) 47 had been replaced by KL64 since 2016. Patients infected with ST11-KL64 CRKP had a significantly higher 30-day mortality rate than other CRKP-infected patients. Enhanced virulence was further evidenced by phenotypic tests. Phylogenetic reconstruction demonstrated that ST11-KL64 is derived from an ST11-KL47-like ancestor through recombination. We identified a pLVPK-like virulence plasmid carrying rmpA and peg-344 in ST11-KL64 exclusively from 2016 onward. The pLVPK-like-positive ST11-KL64 isolates exhibited enhanced environmental survival. Retrospective screening of a national collection identified ST11-KL64 in multiple regions. Targeted surveillance of this high-risk CRKP clone is urgently needed.

Hypervirulent Klebsiella pneumoniae (hvKp) is globally disseminating as a community-acquired pathogen causing life-threatening infections in healthy individuals. The fact that a dose as little as 50 bacteria is lethal to mice illustrates the dramatic increase of virulence associated with hvKp strains compared with classical K. pneumoniae (cKp) strains, which require lethal doses greater than 10⁷ bacteria. Until recently, these virulent strains were mostly antibiotic-susceptible. However, multidrug-resistant (MDR) hvKp strains have been emerging, spawning a new generation of hypervirulent “superbugs.” The mechanisms of hypervirulence are not fully defined, but overproduction of capsular polysaccharide significantly impedes host clearance, resulting in increased pathogenicity of hvKp strains. While there are more than 80 serotypes of K. pneumoniae, the K1 and K2 serotypes cause the vast majority of hypervirulent infections. Therefore, a glycoconjugate vaccine targeting these 2 serotypes could significantly reduce hvKp infection. Conventionally, glycoconjugate vaccines are manufactured using intricate chemical methodologies to covalently attach purified polysaccharides to carrier proteins, which is widely considered to be technically challenging. Here we report on the recombinant production and analytical characterization of bioconjugate vaccines, enzymatically produced in glycoengineered Escherichia coli cells, against the 2 predominant hypervirulent K. pneumoniae serotypes, K1 and K2. The K. pneumoniae bioconjugates are immunogenic and efficacious, protecting mice against lethal infection from 2 hvKp strains, NTUH K-2044 and ATCC 43816. This preclinical study constitutes a key step toward preventing further global dissemination of hypervirulent MDR hvKp strains.

Health officials are watching in horror as bacteria become resistant to powerful carbapenem antibiotics — one of the last drugs on the shelf.

Klebsiella pneumoniae carbapenemases (KPCs) were originally identified in the USA in 1996. Since then, these versatile β-lactamases have spread internationally among Gram-negative bacteria, especially K pneumoniae, although their precise epidemiology is diverse across countries and regions. The mortality described among patients infected with organisms positive for KPC is high, perhaps as a result of the limited antibiotic options remaining (often colistin, tigecycline, or aminoglycosides). Triple drug combinations using colistin, tigecycline, and imipenem have recently been associated with improved survival among patients with bacteraemia. In this Review, we summarise the epidemiology of KPCs across continents, and discuss issues around detection, present antibiotic options and those in development, treatment outcome and mortality, and infection control. In view of the limitations of present treatments and the paucity of new drugs in the pipeline, infection control must be our primary defence for now.

Klebsiella pneumoniae causes community- and healthcare-associated infections in children and adults. Globally in 2019, an estimated 1.27 million (95% Uncertainty Interval [UI]: 0.91–1.71) and 4.95 million (95% UI: 3.62–6.57) deaths were attributed to and associated with bacterial antimicrobial resistance (AMR), respectively. K. pneumoniae was the second leading pathogen in deaths attributed to AMR resistant bacteria. Furthermore, the rise of antimicrobial resistance in both community- and hospital-acquired infections is a concern for neonates and infants who are at high risk for invasive bacterial disease. There is a limited antibiotic pipeline for new antibiotics to treat multidrug resistant infections, and vaccines targeted against K. pneumoniae are considered to be of priority by the World Health Organization. Vaccination of pregnant women against K. pneumoniae could reduce the risk of invasive K.pneumoniae disease in their young offspring. In addition, vulnerable children, adolescents and adult populations at risk of K. pneumoniae disease with underlying diseases such as immunosuppression from underlying hematologic malignancy, chemotherapy, patients undergoing abdominal and/or urinary surgical procedures, or prolonged intensive care management are also potential target groups for a K. pneumoniae vaccine. A ‘Vaccine Value Profile’ (VVP) for K.pneumoniae, which contemplates vaccination of pregnant women to protect their babies from birth through to at least three months of age and other high-risk populations, provides a high-level, holistic assessment of the available information to inform the potential public health, economic and societal value of a pipeline of K. pneumoniae vaccines and other preventatives and therapeutics. This VVP was developed by a working group of subject matter experts from academia, non-profit organizations, public–private partnerships, and multi-lateral organizations, and in collaboration with stakeholders from the WHO. All contributors have extensive expertise on various elements of the K.pneumoniae VVP and collectively aimed to identify current research and knowledge gaps. The VVP was developed using only existing and publicly available information.

Background. During 2006, Israeli hospitals faced a clonal outbreak of carbapenem-resistant Klebsiella pneumoniae that was not controlled by local measures. A nationwide intervention was launched to contain the outbreak and to introduce a strategy to control future dissemination of antibiotic-resistant bacteria in hospitals. Methods. In March 2007, the Ministry of Health issued guidelines mandating physical separation of hospitalized carriers of carbapenem-resistant Enterobacteriaceae (CRE) and dedicated staffing and appointed a professional task force charged with containment. The task force paid site visits at acute-care hospitals, evaluated infection-control policies and laboratory methods, supervised adherence to the guidelines via daily census reports on carriers and their conditions of isolation, provided daily feedback on performance to hospital directors, and intervened additionally when necessary. The initial intervention period was 1 April 2007-31 May 2008. The primary outcome measure was incidence of clinically diagnosed nosocomial CRE cases. Results. By 31 March 2007, 1275 patients were affected in 27 hospitals (175 cases per 1 million population). Prior to the intervention, the monthly incidence of nosocomial CRE was 55.5 cases per 100,000 patient-days. With the intervention, the continuous increase in the incidence of CRE acquisition was halted, and by May 2008, the number of new monthly cases was reduced to 11.7 cases per 100,000 patient-days (P <.001). There was a direct correlation between compliance with isolation guidelines and success in containment of transmission (P = .02). Compliance neutralized the effect of carrier prevalence on new incidence (P = .03). Conclusions. A centrally coordinated intervention succeeded in containing a nationwide CRE outbreak after local measures failed. The intervention demonstrates the importance of strategic planning and national oversight in combating antimicrobial resistance.

Objectives This review fills the paucity of information on K. pneumoniae as a nosocomial pathogen by providing pooled data on epidemiological risk factors, resistant trends and profiles and resistant and virulent genes of this organism in Asia. Methods Exhaustive search was conducted using PubMed, Web of Science, and Google scholar for most studies addressing the prevalence, risk factors, drug resistant-mediated genes and/or virulent factors of K. pneumoniae in Asia. Data extracted for meta-analysis were analyzed using comprehensive meta-analysis version 3. Trends data for the isolation rate and resistance rates were entered into Excel spread sheet and the results were presented in graphs. Results The prevalence rate of drug resistance in K. pneumoniae were; amikacin (40.8%) [95% CI 31.9–50.4], aztreonam (73.3%) [95% CI 59.9–83.4], ceftazidime (75.7%) [95% CI 65.4–83.6], ciprofloxacin (59.8%) [95% CI 48.6–70.1], colistin (2.9%) [95% CI 1.8–4.4], cefotaxime (79.2%) [95% CI 68.0–87.2], cefepime (72.6) [95% CI 57.7–83.8] and imipenem (65.6%) [95% CI 30.8–89.0]. TEM (39.5%) [95% CI 15.4–70.1], SHV-11 (41.8%) [95% CI 16.2–72.6] and KPC-2 (14.6%) [95% CI 6.0–31.4] were some of the resistance mediated genes observed in this study. The most virulent factors utilized by K. pneumoniae are; hypermucoviscous phenotype and mucoviscosity-related genes, genes for biosynthesis of lipopolysaccharide, iron uptake and transport genes and finally, adhesive genes. Conclusion It can be concluded that, antimicrobial resistant in K. pneumoniae is a clear and present danger in Asia which needs strong surveillance to curb this menace. It is very important for public healthcare departments to monitor and report changes in antimicrobial-resistant isolates.

PurposeCarbapenem-resistant Klebsiella pneumoniae (CRKP) is one of the leading causes of healthcare-associated infections (HAIs) and is particularly pervasive in intensive care units (ICUs). This study takes ICU layout as the research object, and integrates clinical data and bacterial genome analysis to clarify the role of separate, small wards within the ICU in controlling the transmission of CRKP.MethodsThis study prospectively observed the carriage and spread of CRKP from a long-term in-hospital patient (hereafter called the Patient) colonized with CRKP in the gut and located in a separate, small ward within the ICU. The study also retrospectively investigated CRKP-HAIs in the same ICU. The relationship and transmission between CRKP isolates from the Patient and HAI events in the ICU were explored with comparative genomics.ResultsIn this study, 65 CRKP-HAI cases occurred during the investigation period. Seven CRKP-HAI outbreaks were also observed. A total of 95 nonrepetitive CRKP isolates were collected, including 32 strains from the Patient in the separate small ward. Phylogenetic analysis based on core genome single-nucleotide polymorphism (cgSNP) showed that there were five possible CRKP clonal transmission events and two clonal outbreaks (A1, A2) during the study. CRKP strains from the Patient did not cause CRKP between-patient transmission or outbreaks in the ICU during the 5-year study period.ConclusionThe presence of a long-term hospitalized patient carrying CRKP and positioned in a separate, small ward did not lead to CRKP transmission or infection outbreaks in the ICU. Combining a small-ward ICU layout with normative HAI control measures for multidrug-resistant pathogen infection was effective in reducing CRKP transmission.

Antibiotic resistance among enterococci and γ-proteobacteria is an increasing problem in healthcare settings. Dense colonization of the gut by antibiotic-resistant bacteria facilitates their spread between patients and also leads to bloodstream and other systemic infections. Antibiotic-mediated destruction of the intestinal microbiota and consequent loss of colonization resistance are critical factors leading to persistence and spread of antibiotic-resistant bacteria. The mechanisms underlying microbiota-mediated colonization resistance remain incompletely defined and are likely distinct for different antibiotic-resistant bacterial species. It is unclear whether enterococci or γ-proteobacteria, upon expanding to high density in the gut, confer colonization resistance against competing bacterial species. Herein, we demonstrate that dense intestinal colonization with vancomycin-resistant Enterococcus faecium (VRE) does not reduce in vivo growth of carbapenem-resistant Klebsiella pneumoniae. Reciprocally, K. pneumoniae does not impair intestinal colonization by VRE. In contrast, transplantation of a diverse fecal microbiota eliminates both VRE and K. pneumoniae from the gut. Fluorescence in situ hybridization demonstrates that VRE and K. pneumoniae localize to the same regions in the colon but differ with respect to stimulation and invasion of the colonic mucus layer. While VRE and K. pneumoniae occupy the same three-dimensional space within the gut lumen, their independent growth and persistence in the gut suggests that they reside in distinct niches that satisfy their specific in vivo metabolic needs.

Background Hospital-acquired infections caused by multidrug resistant (MDR) Klebsiella pneumoniae pose a significant global health threat. Effective antisepsis and disinfection protocols are mandatory to prevent these infections. This study aimed to isolate Klebsiella pneumoniae , evaluate antimicrobial susceptibility, and assess the efficacy of selected biocides. Methods Fifty clinical MDR Klebsiella pneumoniae isolates were collected from various hospital departments. Antimicrobial susceptibility was determined using the disc diffusion method. Minimum inhibitory concentrations (MICs) of chlorhexidine and benzalkonium chloride were measured via agar dilution. Conventional PCR was employed to detect biocide resistance genes ( qacE∆1 and cepA ). Results Klebsiella pneumoniae was identified in 19.16% of cases. All isolates exhibited multidrug resistance, with multiple antimicrobial resistance indices ranging from 0.24 to 0.92, reaching up to 1. Benzalkonium chloride MICs significantly increased with resistance, reaching up to 64 µg/mL, while chlorhexidine MICs were consistent across isolates. The qacE∆1 and cepA genes were detected in 62% and 72% of isolates, respectively, with a significant association between qacE∆1 and cephalosporin resistance. No significant correlation was found between biocide MICs and clinical specimen types or hospital units. Conclusion The cepA gene is closely associated with extensive drug resistance in Klebsiella pneumoniae , emphasizing its role in antimicrobial resistance. Optimized biocide formulations, when properly developed and applied, can play a crucial role in combating and preventing infections caused by multidrug-resistant Klebsiella pneumoniae . Clinical trial number Not applicable.