Hypervirulent carbapenem-resistant Klebsiella pneumoniae causing highly fatal meningitis in southeastern China

Comprehensive analysis of the Global Burden and epidemiological trends of meningitis from 1990 to 2021

BACKGROUND

Despite significant advances in prevention and treatment strategies, meningitis continues to pose a substantial global health challenge. The disease burden demonstrates marked geographical disparities, with disproportionate impact in resource-limited settings, particularly within the "meningitis belt" of Sub-Saharan Africa. The global meningitis burden is influenced by a complex interplay of environmental, behavioral, and socioeconomic determinants.

METHODS

Leveraging the Global Burden of Disease (GBD) 2021 database, we conducted a comprehensive analysis of global meningitis burden from 1990 to 2021. The study employed DisMod-MR 2.1, an advanced Bayesian meta-regression tool, for epidemiological modeling. We implemented age-period-cohort analysis to evaluate mortality trends and utilized the Comparative Risk Assessment framework to assess risk factors. The relationship between socio-demographic index (SDI) and disease burden was examined through Spearman's rank correlation analysis.

RESULTS

Our analysis revealed significant geographical and pathogen-specific variations in disease burden. Globally, the age-standardized incidence rate stands at 31.65 per 100,000 with a corresponding mortality rate of 2.95 per 100,000. The disease burden demonstrates a striking gradient across SDI levels, with low SDI regions experiencing the highest burden, approximately 17 times higher than high SDI regions. Neonatal mortality rates remain particularly concerning at 129.69 per 100,000, while under-5 mortality rates stand at 34.50 per 100,000. The Eastern Sub-Saharan African region emerges as an area of particular concern, with disease burden significantly exceeding global averages. Behavioral risks, child and maternal malnutrition, and low birth weight/short gestation emerged as the primary risk factors, each contributing to 0.15 million deaths and 13.41 million DALYs. Strong negative correlations were observed between all risk factors and SDI values (correlation coefficients ranging from - 0.55 to -0.75), indicating higher disease burden in regions with lower socio-demographic development.

CONCLUSION

While substantial progress has been achieved in global meningitis control, particularly in reducing under-5 mortality rates, significant disparities persist between high and low SDI regions. Our findings emphasize the critical need for targeted interventions in resource-limited settings and continued surveillance efforts to address remaining challenges in meningitis control.

Clinical characteristics and mortality risk factors of premature infants with carbapenem-resistant Klebsiella pneumoniae bloodstream infection

Due to the resistance of carbapenem-resistant Klebsiella pneumoniae (CRKP) to most antibiotics, CRKP treatment is challenging, which results a high mortality rate. CRKP infection poses a significant challenge for infection management and treatment, especially among neonates and premature infants. Therefore, it is important to understand the clinical characteristics of CRKP bloodstream infection (BSI) in premature infants and identify the related risk factors for death. This study aims to explore and analyze the clinical characteristics and risk factors affecting mortality of BSI caused by CRKP in premature infants. A retrospective study was conducted in a Children's Hospital in Henan to analyze clinical data of premature infants with CRKP BSI admitted from January 2015 to December 2022. Univariate and multivariate logistic regression models were utilized to investigate risk factors affecting mortality. Receiver operating characteristic curves were employed to evaluate the predictive value of different indicators on mortality, and differences in area under the curve (AUC) were compared using Stata 17 SE. A total of 96 premature infants with CRKP BSI were enrolled, including 70 patients in the survival group and 26 in the death group. At the onset of infection, 69 (71.9%) patients exhibited persistent tachycardia (heart rate > 180 beats/min), 61 (63.5%) had fever, and 59 (61.4%) experienced apnea episodes. Concurrent meningitis (OR 9.588, 95% CI 1.401-57.613, P = 0.021), concurrent necrotizing enterocolitis (NEC) (OR 7.881, 95% CI 1.672-73.842, P = 0.032), and the maximum vasoactive-inotropic score (VIS) value within 48 h of onset (OR 1.467, 95% CI 1.021-1.782, P = 0.001) were identified as independent risk factors for mortality. The univariate analysis showed that ceftazidime-avibactam (CAZ/AVI) treatment and appropriate early antimicrobial treatment were significantly associated with survival (P < 0.05). The combined predictive AUC for mortality in premature infants with CRKP BSI using the maximum VIS value ≥ 52.5 points within 48 h of onset, concurrent NEC, and purulent meningitis was 0.931 (95% CI 0.856-1.000) with a sensitivity of 92% and specificity of 85.7%. CRKP BSI was a significant mortality risk in premature infants. It is crucial to administer proper antimicrobial therapy in order to increase survival rates of the patients. CAZ/AVI has the potential to improve outcomes in this particular population; however, further research is required to evaluate the effectiveness of specific treatment in premature infants.

A nosocomial outbreak of colistin and carbapenem-resistant hypervirulent Klebsiella pneumoniae in a large teaching hospital

Recently, colistin and carbapenem-resistant hypervirulent Klebsiella pneumoniae (CCR-hvKP) has been observed sporadically. The aim of this study was to report a nosocomial outbreak due to CCR-hvKP, so as to control the transmission of CCR-hvKP and prevent future outbreaks. The clinical characteristics of five involved cases were analyzed and infection prevention and control measures were documented. Five CCR-hvKP isolates were discovered from the five involved cases. Molecular features of the isolates including sequence type, capsule locus, antimicrobial resistance genes, virulence factors and phylogenetic relationship were analyzed by whole-genome sequencing. Validation of the role of the deleterious amino acid mutations to colistin resistance was examined by complementation assays. PCR was performed to identify insertion sequences within the mgrB gene. Mouse intraperitoneal infection models were used to assess virulence phenotype. Five cases infected with CCR-hvKP were identified with a high attributable mortality rate of 60% in the patients. The five outbreak isolates belonged to the high-risk ST11-KL64 clone and were closely clustered. They were highly resistant to commonly used antibiotics and showed hypervirulent in vivo. WGS revealed multiple antimicrobial resistance genes such as blaKPC-2 and blaCTX-M-65 and important virulence factors. Concerning colistin resistance, amino acid mutations G53S in pmrA gene, and T157P, T246A and R256G in pmrB gene were indentified. Among them, the deleterious mutation T157P in pmrB gene was validated to be responsible for the resistance phenotype of isolate KP01, KP03 and KP05. In addition, disruption of mgrB gene by insertion sequences of ISKpn26 and IS903B was indentified in isolate KP02 and KP04, respectively. This is the first report of an outbreak caused by CCR-hvKP. The study highlights infection prevention and control measures are key to successfully fight against CCR-hvKP dissemination and nosocomial infections. Continuous surveillance should be performed to limit the spread of these isolates.

The Use of Cefiderocol in Gram-Negative Bacterial Infections at International Medical Center, Jeddah, Saudi Arabia

BACKGROUND/OBJECTIVES

The necessity for ground-breaking treatments for Gram-negative infections is evident. The World Health Organization, the Infectious Diseases Society of America, and the European Commission have highlighted the critical insufficiency of efficient antibiotics, urging pharmaceutical businesses to manufacture new antibiotics. Therefore, developing new antibiotics with broad efficacy against Gram-negative pathogens is essential. Thus, this research aimed to evaluate the safety and effectiveness of cefiderocol in treating multidrug-resistant Gram-negative bacterial infections at the International Medical Center (IMC), Jeddah, Saudi Arabia.

METHODS

A retrospective analysis was conducted on patients treated from January 2021 to February 2023. Thirteen case groups treated with cefiderocol were compared to twenty control groups treated with other antibiotics.

RESULTS

The results indicated no statistically significant differences in ICU stay, comorbidity indices, or mortality rates between the two groups. Cefiderocol showed high clinical and microbiological cure rates, despite the severity of the patients' conditions. Carbapenem-resistant Klebsiella pneumoniae and difficult-to-treat resistance Pseudomonas aeruginosa were the most prevalent pathogens in the case and control group, respectively. Two patients treated with cefiderocol developed Clostridioides difficile infection, emphasizing the need for close monitoring of potential adverse effects.

CONCLUSIONS

The results of this study support cefiderocol as a viable alternative for managing serious infections instigated by multidrug-resistant Gram-negative bacteria.

Hypervirulent and carbapenem-resistant Klebsiella pneumoniae: A global public health threat

The evolution of hypervirulent and carbapenem-resistant Klebsiella pneumoniae can be categorized into three main patterns: the evolution of KL1/KL2-hvKp strains into CR-hvKp, the evolution of carbapenem-resistant K. pneumoniae (CRKp) strains into hv-CRKp, and the acquisition of hybrid plasmids carrying carbapenem resistance and virulence genes by classical K. pneumoniae (cKp). These strains are characterized by multi-drug resistance, high virulence, and high infectivity. Currently, there are no effective methods for treating and surveillance this pathogen. In addition, the continuous horizontal transfer and clonal spread of these bacteria under the pressure of hospital antibiotics have led to the emergence of more drug-resistant strains. This review discusses the evolution and distribution characteristics of hypervirulent and carbapenem-resistant K. pneumoniae, the mechanisms of carbapenem resistance and hypervirulence, risk factors for susceptibility, infection syndromes, treatment regimens, real-time surveillance and preventive control measures. It also outlines the resistance mechanisms of antimicrobial drugs used to treat this pathogen, providing insights for developing new drugs, combination therapies, and a "One Health" approach. Narrowing the scope of surveillance but intensifying implementation efforts is a viable solution. Monitoring of strains can be focused primarily on hospitals and urban wastewater treatment plants.

Metagenome mining divulges virulent and multidrug resistant Pseudomonas aeruginosa ST242 and Klebsiella michiganensis ST∗1b23 coinfecting an 8-month-old meningitis infant under ICU in Kampala, Uganda, East Africa

Pediatric meningitis is a global health problem, with insufficiently known pathogens and antibiotic resistance (AMR) especially in low-resource settings. Here, we sought to uncover the virulence and AMR of pathogens associated with infant meningitis, treated with ceftriaxone, in Kampala, Uganda. In a bid to isolate Klebsiella oxytoca, we coincidentally recovered a co-culture and challenged it with antibiotic susceptibility testing (AST) on a panel of 14 antibiotics. We then combined metagenome binning with antiSMASH/PRISM genome mining to unveil the pathogens, their virulence and molecular targets in relation to meningitis. From AST, the co-culture exhibited resistance to multiple aminoglycosides, fluroquinolones, and β-lactams, including ceftriaxone, the inherently used drug. From metagenome annotation, the first bin was identified as Pseudomonas aeruginosa ST242 and the second as Klebsiella michiganensis ST∗1b23. Among others, P. aeruginosa ST242 virulence factors include type 3 and type 6 secretion systems, biofilm, and nonribosomal peptides (NRPs) of the pyoverdine synthase operon, targeting claudin-5, a component of the tight junctions of the blood-brain barrier (BBB). The P. aeruginosa ST242 genome portrays intrinsic resistance to beta-lactamases (blaOXA-50 and blaPAO), aminoglycosides [aph(3')-IIb)], fluoroquinolones (crpP), tetracycline (tmexD2) and fosfomycin (fosA), among others. From K. michiganensis ST∗1b23 genome mining we elucidated a yersiniabactin-related metabolite, targeting the ligand-binding domain of the human polymeric immunoglobulin receptor (pIgR) and other components of the BBB. The K. michiganensis ST∗1b23 chromosome encodes the genes blaOXY-1 and OqxA/B, conferring resistance to β-lactams, fluoroquinolones, and trimethoprim respectively. Notably, we found one frameshift and nine substitution mutations conferring carbapenem and cephalosporin resistance mechanisms. Overall, our findings strongly suggest coinfection and a mechanistic crosstalk between P. aeruginosa ST242 and K. michiganensis ST∗1b23 in the pathogenesis of meningitis in this case. Importantly, ceftriaxone could be an inappropriate treatment choice for these pathogens. Hence, serious surveillance and experimental studies will improve the management of pediatric meningitis.

Clinical and laboratory insights into the threat of hypervirulent Klebsiella pneumoniae

Hypervirulent Klebsiella pneumoniae (hvKP) typically causes severe invasive infections affecting multiple sites in healthy individuals. In the past, hvKP was characterized by a hypermucoviscosity phenotype, susceptibility to antimicrobial agents, and its tendency to cause invasive infections in healthy individuals within the community. However, there has been an alarming increase in reports of multidrug-resistant hvKP, particularly carbapenem-resistant strains, causing nosocomial infections in critically ill or immunocompromised patients. This presents a significant challenge for clinical treatment. Early identification of hvKP is crucial for timely infection control. Notably, identifying hvKP has become confusing due to its prevalence in nosocomial settings and the limited predictive specificity of the hypermucoviscosity phenotype. Novel virulence predictors for hvKP have been discovered through animal models or machine learning algorithms, while standardization of identification criteria is still necessary. Timely source control and antibiotic therapy have been widely employed for the treatment of hvKP infections. Additionally, phage therapy is a promising alternative approach due to escalating antibiotic resistance. In summary, this narrative review highlights the latest research progress in the development, virulence factors, identification, epidemiology of hvKP, and treatment options available for hvKP infection.

Antibiotic resistance and epidemiological characteristics of polymyxin-resistant Klebsiella pneumoniae

OBJECTIVES

The emergence of polymyxin-resistant Klebsiella pneumoniae (KPN) in clinical settings necessitates an analysis of its antibiotic resistance characteristics, epidemiological features, and risk factors for its development. This study aims to provide insights for the prevention and control of polymyxin-resistant KPN infections.

METHODS

Thirty clinical isolates of polymyxin-resistant KPN were collected from the Third Xiangya Hospital of Central South University. Their antibiotic resistance profiles were analyzed. The presence of carbapenemase KPC, OXA-48, VIM, IMP, and NDM was detected using colloidal gold immunochromatography. Hypervirulent KPN was initially screened using the string test. Biofilm formation capacity was assessed using crystal violet staining. Combination drug susceptibility tests (polymyxin B with meropenem, tigecycline, cefoperazone/sulbactam) were conducted using the checkerboard method. Polymyxin-related resistance genes were detected by PCR. Multi-locus sequence typing (MLST) was performed for genotyping and phylogenetic tree construction. The study also involved collecting data from carbapenem-resistant (CR)-KPN polymyxin-resistant strains (23 strains, experimental group) and CR-KPN polymyxin-sensitive strains (57 strains, control group) to analyze potential risk factors for polymyxin-resistant KPN infection through univariate analysis and multivariate Logistic regression. The induction of resistance by continuous exposure to polymyxin B and colistin E was also tested.

RESULTS

Among the 30 polymyxin-resistant KPN isolates, 28 were CR-KPN, all producing KPC enzyme. Four isolates were positive in the string test. Most isolates showed strong biofilm formation capabilities. Combination therapy showed additive or synergistic effects. All isolates carried the pmrA and phoP genes, while no mcr-1 or mcr-2 genes were detected. MLST results indicated that ST11 was the predominant type. The phylogenetic tree suggested that polymyxin-resistant KPN had not caused a hospital outbreak in the institution. The use of two or more different classes of antibiotics and the use of polymyxin were identified as independent risk factors for the development of polymyxin-resistant strains. Continuous use of polymyxin induced drug resistance.

CONCLUSIONS

Polymyxin-resistant KPN is resistant to nearly all commonly used antibiotics, making polymyxin-based combination therapy a viable option. No plasmid-mediated polymyxin-resistant KPN has been isolated in the hospital. Polymyxin can induce resistance in KPN, highlighting the need for rational antibiotic use in clinical settings to delay the emergence of resistance.

Expansion and transmission dynamics of high risk carbapenem-resistant Klebsiella pneumoniae subclones in China: An epidemiological, spatial, genomic analysis

AIMS

Carbapenem-resistant Klebsiella pneumonia (CRKP) is a global threat that varies by region. The global distribution, evolution, and clinical implications of the ST11 CRKP clone remain obscure.

METHODS

We conducted a multicenter molecular epidemiological survey using isolates obtained from 28 provinces and municipalities across China between 2011 and 2021. We integrated sequences from public databases and performed genetic epidemiology analysis of ST11 CRKP.

RESULTS

Among ST11 CRKP, KL64 serotypes exhibited considerable expansion, increasing from 1.54% to 46.08% between 2011 and 2021. Combining our data with public databases, the phylogenetic and phylogeography analyses indicated that ST11 CRKP appeared in the Americas in 1996 and spread worldwide, with key clones progressing from China's southeastern coast to the inland by 2010. Global phylogenetic analysis showed that ST11 KL64 CRKP has evolved to a virulent, resistant clade with notable regional spread. Single-nucleotide polymorphism (SNP) analysis identified BMPPS (bmr3, mltC, pyrB, ppsC, and sdaC) as a key marker for this clade. The BMPPS SNP clade is associated with high mortality and has strong anti-phagocytic and competitive traits in vitro.

CONCLUSIONS

The high-risk ST11 KL64 CRKP subclone showed strong expansion potential and survival advantages, probably owing to genetic factors.

Clinical characteristics and prognosis of Klebsiella pneumoniae meningitis in adults

Background

Klebsiella pneumoniae is a causative agent of bacterial meningitis in adults. However, there is little information regarding this infection. Therefore, this study comprehensively analyzed the clinical characteristics and prognosis of Klebsiella pneumoniae meningitis (KPM) patients.

Methods

The clinical data of adult hospitalized patients with KPM were retrospectively collected from January 2015 to December 2022. The clinical characteristics and antibiotic resistance of KPM were evaluated. Meanwhile, a set of logistic regression models was constructed to identify prognostic factors for death. These prognostic factors were subsequently combined to develop a nomogram for predicting the risk of in-hospital mortality in individual patients. Finally, the receiver operating characteristic curve and calibrate plot were utilized to verify the performance of the nomogram.

Results

This study included 80 adult patients with KPM, 58 (72.5%) of whom were males. The mortality rate was 45%. Among them, 74 (92.5%) were diagnosed with healthcare-associated meningitis. Thirty-seven carbapenem-resistant Klebsiella pneumoniae (CRKP) strains were susceptible to tigecycline, polymyxin, and ceftazidime/avibactam. CRKP (OR = 9.825, 95%CI = 2.757-35.011, P < 0.001), length of stay (OR = 0.953, 95%CI = 0.921-0.986, P = 0.005), and C-reactive protein-to-prealbumin ratio (CRP/PA, OR = 3.053, 95%CI = 1.329-7.016, P = 0.009) were identified as predictive factors for mortality using multivariate logistic regression. Finally, a nomogram for death prediction was established. The area under the curve of this nomogram was 0.900 (95% CI = 0.828-0.971).

Conclusions

KPM is a fatal disease associated with high incidence of healthcare-associated infections and carbapenem resistance. Moreover, CRKP, length of stay, and CRP/PA were found to be independent predictors of mortality.

The Global and Regional Prevalence of Hospital-Acquired Carbapenem-Resistant Klebsiella pneumoniae Infection: A Systematic Review and Meta-analysis

Background

Due to scarce therapeutic options, hospital-acquired infections caused by Klebsiella pneumoniae (KP), particularly carbapenem-resistant KP (CRKP), pose enormous threat to patients' health worldwide. This study aimed to characterize the epidemiology and risk factors of CRKP among nosocomial KP infections.

Method

MEDLINE, Embase, PubMed, and Google Scholar were searched for studies reporting CRKP prevalence from inception to 30 March 2023. Data from eligible publications were extracted and subjected to meta-analysis to obtain global, regional, and country-specific estimates. To determine the cause of heterogeneity among the selected studies, prespecified subgroup analyses and meta-regression were also performed. Odds ratios of CRKP-associated risk factors were pooled by a DerSimonian and Laird random-effects method.

Results

We retained 61 articles across 14 countries and territories. The global prevalence of CRKP among patients with KP infections was 28.69% (95% CI, 26.53%-30.86%). South Asia had the highest CRKP prevalence at 66.04% (95% CI, 54.22%-77.85%), while high-income North America had the lowest prevalence at 14.29% (95% CI, 6.50%-22.0%). In the country/territory level, Greece had the highest prevalence at 70.61% (95% CI, 56.77%-84.45%), followed by India at 67.62% (95% CI, 53.74%-81.79%) and Taiwan at 67.54% (95% CI, 58.65%-76.14%). Hospital-acquired CRKP infections were associated with the following factors: hematologic malignancies, corticosteroid therapies, intensive care unit stays, mechanical ventilations, central venous catheter implantations, previous hospitalization, and antibiotic-related exposures (antifungals, carbapenems, quinolones, and cephalosporins).

Conclusions

Study findings highlight the importance of routine surveillance to control carbapenem resistance and suggest that patients with nosocomial KP infection have a very high prevalence of CRKP.

Hepatitis E virus and Klebsiella pneumoniae co-infection detected by metagenomics next-generation sequencing in a patient with central nervous system and bloodstream Infection: a case report

BACKGROUND

Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis worldwide with major prevalence in the developing countries and can cause extrahepatic disease including the nervous system. Central nervous system infections caused by HEV are rare and caused by HEV together with other bacteria are even rarer.

CASE PRESENTATION

A 68-year-old man was admitted to the hospital due to a headache lasting for 6 days and a fever for 3 days. Lab tests showed significantly raised indicators of inflammation, cloudy cerebrospinal fluid, and liver dysfunction. Hepatitis E virus and Klebsiella pneumoniae were identified in the blood and cerebrospinal fluid using metagenomic next-generation sequencing. The patient received meropenem injection to treat K. pneumoniae infection, isoglycoside magnesium oxalate injection and polyene phosphatidylcholine injection for liver protection. After ten days of treatment, the patient improved and was discharged from the hospital.

CONCLUSION

Metagenomic next-generation sequencing, which can detect various types of microorganisms, is powerful for identifying complicated infections.

Carbapenem resistant Enterobacterales in the United Arab Emirates: a retrospective analysis from 2010 to 2021

BACKGROUND

Carbapenem-resistant Enterobacterales (CRE) are spreading in the United Arab Emirates (UAE) where their dissemination is facilitated by international travel, trade, and tourism. The objective of this study is to describe the longitudinal changes of CRE as reported by the national AMR surveillance system of the UAE.

METHODS

In this study, we retrospectively describe CRE isolated from 317 surveillance sites, including 87 hospitals and 230 centers/clinics from 2010 to 2021. The associated clinical, demographic, and microbiological characteristics are presented by relying on the UAE national AMR surveillance program. Data was analyzed using WHONET microbiology laboratory database software (http://www.whonet.org).

RESULTS

A total of 14,593 carbapenem resistant Enterobacterales were analyzed, of which 48.1% were carbapenem resistant Klebsiella pneumoniae (CRKp), 25.1% carbapenem resistant Escherichia coli (CREc), and 26.8% represented 72 other carbapenem resistant species. Carbapenem resistant strains were mostly associated with adults and isolated from urine samples (36.9% of CRKp and 66.6% of CREc) followed by respiratory samples (26.95% for CRKp) and soft tissue samples (19.5% for CRKp). Over the studied period carbapenem resistance rates remained high, especially in K. pneumoniae, and in 2021 were equivalent to 67.6% for imipenem, 76.2% for meropenem, and 91.6% for ertapenem. Nevertheless, there was a statistically significant decreasing trend for imipenem and meropenem resistance in Klebsiella species (p < 0.01) while the decrease in ertapenem resistance was non-significant. Concerning E. coli, there was a statistically significant decreasing trend for meropenem and imipenem resistance over the 12 years, while ertapenem resistance increased significantly with 83.8% of E. coli exhibiting ertapenem resistance in 2021. Resistance rates to ceftazidime and cefotaxime remained higher than 90% (in 2021) for CRKp and cefotaxime rates increased to 90.5% in 2021 for CREc. Starting 2014, resistance to colistin and tigecycline was observed in carbapenem resistant Enterobacterales. CRE were associated with a higher mortality (RR: 6.3), admission to ICU (RR 3.9), and increased length of stay (LOS; 10 excess inpatient days per CRE case).

CONCLUSION

This study supports the need to monitor CRE in the UAE and draws attention to the significant increase of ertapenem resistance in E. coli. Future surveillance analysis should include a genetic description of carbapenem resistance to provide new strategies.

The dynamic evolution and IS26-mediated interspecies transfer of a blaNDM-1-bearing fusion plasmid leading to a hypervirulent carbapenem-resistant Klebsiella pneumoniae strain harbouring blaKPC-2 in a single patient

OBJECTIVES

To characterize the evolution and interspecies transfer of plasmids between Klebsiella pneumoniae and Escherichia coli within a single patient.

METHODS

Minimum inhibitory concentrations were measured using broth microdilution assays. Conjugation assays, string tests, and Galleria mellonella infection model experiments were also conducted. Whole-genome sequencing was performed on the Illumina and Nanopore platforms. Antimicrobial resistance determinants, insertion sequences, and virulence factors were identified using ABRicate/ResFinder database, ISFinder, and virulence factor database. Wzi and capsular polysaccharide (KL) were typed using Kleborate and Kaptive. Multi-locus sequence typing (MLST), replicon typing, and single nucleotide polymorphism analyses were conducted using the BacWGSTdb server.

RESULTS

The carbapenem-resistant K. pneumoniae 2111KP was characterized as ST11, wzi64, and KL64, with a positive string test result and a relatively high virulence phenotype. Analysis of the 2111KP genome revealed that blaNDM-1 was located in a 268,400-bp IncFIB/IncHI1B/IncX3 conjugative plasmid (p2111KP-1), regulated by IS26, IS5, and ISKox3. p2111KP-1 was also a rmpA2-associated virulence plasmid with an iutA-iucABCD gene cluster and a IS26-mediated multidrug-resistant fusion plasmid, which contained 8-bp (AGCTGCAC or GGCCTTTG) target site duplications. Segments flanked by IS26 of p2111KP-1 were 99.99% identical to a 49,016-bp E. coli plasmid.

CONCLUSIONS

This study provided direct evidence of plasmid fusion via IS26 between two different bacterial species within one patient and revealed the process by which genetic elements conferring carbapenem resistance and virulence were simultaneously transferred between these species. It highlights the need for strategic antibiotic use and rigorous monitoring to prevent the plasmid-mediated fusion and transmission of drug-resistance/virulence factors.

"Superbugs" with hypervirulence and carbapenem resistance in Klebsiella pneumoniae: the rise of such emerging nosocomial pathogens in China

Although hypervirulent Klebsiella pneumoniae (hvKP) can produce community-acquired infections that are fatal in young and adult hosts, such as pyogenic liver abscess, endophthalmitis, and meningitis, it has historically been susceptible to antibiotics. Carbapenem-resistant K. pneumoniae (CRKP) is usually associated with urinary tract infections acquired in hospitals, pneumonia, septicemias, and soft tissue infections. Outbreaks and quick spread of CRKP in hospitals have become a major challenge in public health due to the lack of effective antibacterial treatments. In the early stages of K. pneumoniae development, HvKP and CRKP first appear as distinct routes. However, the lines dividing the two pathotypes are vanishing currently, and the advent of carbapenem-resistant hypervirulent K. pneumoniae (CR-hvKP) is devastating as it is simultaneously multidrug-resistant, hypervirulent, and highly transmissible. Most CR-hvKP cases have been reported in Asian clinical settings, particularly in China. Typically, CR-hvKP develops when hvKP or CRKP acquires plasmids that carry either the carbapenem-resistance gene or the virulence gene. Alternatively, classic K. pneumoniae (cKP) may acquire a hybrid plasmid carrying both genes. In this review, we provide an overview of the key antimicrobial resistance mechanisms, virulence factors, clinical presentations, and outcomes associated with CR-hvKP infection. Additionally, we discuss the possible evolutionary processes and prevalence of CR-hvKP in China. Given the wide occurrence of CR-hvKP, continued surveillance and control measures of such organisms should be assigned a higher priority.

Dissemination and characteristics of carbapenem-resistant Klebsiella pneumoniae in nine district hospitals in southwestern China

Background

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is epidemically transmitted globally, but few studies focused on the prevalence in district-level hospitals. In this study, we investigated CRKP strains collected from nine district hospitals from September 2019 to September 2020, aiming to determine the resistance mechanisms, virulence profiles, and molecular epidemiological characteristics of CRKP in district hospitals in Southwest China.

Methods

A total of 51 CRKP strains were collected from 9 district-level hospitals. Matrix-assisted laser desorption/ionization-time of flight mass spectrometer was used for strain identification review, and the micro-broth dilution method was used for antibiotic sensitivity detection. Molecular epidemiological investigation of strains was performed by multilocus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE) methods. PCR and efflux pump inhibition tests were used to detect CRKP resistance mechanisms. PCR and serum killing tests were used to detect capsular serotype, virulence-related genes, and virulence validation.

Results

The CRKP strains in district hospitals presented high levels of MIC50 and MIC90 in carbapenem antibiotics especially ertapenem and meropenem. A total of 90.2% (46/51) CRKP strains were detected as carbapenemase producers, and the proportion of strains co-expressing carbapenemases was 11.8% (6/51). All CRKP strains were grouped into eight MLST types, and ST11 was the most prevalent genotype. A total of 11.8% (6/51) CRKP isolates were positive for the string test, and three strains of hypervirulent and carbapenem-resistant K. pneumoniae (HV-CRKP) were positive in serum killing test. The molecular typing of all the CRKP isolates was grouped into 29 different PFGE patterns, and 40 ST11 isolates belonged to 20 different PFGE clusters.

Conclusion

CRKP strains showed high-level antibiotic resistance and virulence phenotype in district hospitals in Southwest China, which suggested that we should immediately pay attention to the rapid dissemination of the CRKP in regional hospitals. Our study will provide new insights into the epidemiology of CRKP in regional hospitals, which will help regional hospitals develop nosocomial infection prevention and control policies tailored to local conditions.

Global, regional, and national burden of meningitis and its aetiologies, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019

BACKGROUND

Although meningitis is largely preventable, it still causes hundreds of thousands of deaths globally each year. WHO set ambitious goals to reduce meningitis cases by 2030, and assessing trends in the global meningitis burden can help track progress and identify gaps in achieving these goals. Using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, we aimed to assess incident cases and deaths due to acute infectious meningitis by aetiology and age from 1990 to 2019, for 204 countries and territories.

METHODS

We modelled meningitis mortality using vital registration, verbal autopsy, sample-based vital registration, and mortality surveillance data. Meningitis morbidity was modelled with a Bayesian compartmental model, using data from the published literature identified by a systematic review, as well as surveillance data, inpatient hospital admissions, health insurance claims, and cause-specific meningitis mortality estimates. For aetiology estimation, data from multiple causes of death, vital registration, hospital discharge, microbial laboratory, and literature studies were analysed by use of a network analysis model to estimate the proportion of meningitis deaths and cases attributable to the following aetiologies: Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae, group B Streptococcus, Escherichia coli, Klebsiella pneumoniae, Listeria monocytogenes, Staphylococcus aureus, viruses, and a residual other pathogen category.

FINDINGS

In 2019, there were an estimated 236 000 deaths (95% uncertainty interval [UI] 204 000-277 000) and 2·51 million (2·11-2·99) incident cases due to meningitis globally. The burden was greatest in children younger than 5 years, with 112 000 deaths (87 400-145 000) and 1·28 million incident cases (0·947-1·71) in 2019. Age-standardised mortality rates decreased from 7·5 (6·6-8·4) per 100 000 population in 1990 to 3·3 (2·8-3·9) per 100 000 population in 2019. The highest proportion of total all-age meningitis deaths in 2019 was attributable to S pneumoniae (18·1% [17·1-19·2]), followed by N meningitidis (13·6% [12·7-14·4]) and K pneumoniae (12·2% [10·2-14·3]). Between 1990 and 2019, H influenzae showed the largest reduction in the number of deaths among children younger than 5 years (76·5% [69·5-81·8]), followed by N meningitidis (72·3% [64·4-78·5]) and viruses (58·2% [47·1-67·3]).

INTERPRETATION

Substantial progress has been made in reducing meningitis mortality over the past three decades. However, more meningitis-related deaths might be prevented by quickly scaling up immunisation and expanding access to health services. Further reduction in the global meningitis burden should be possible through low-cost multivalent vaccines, increased access to accurate and rapid diagnostic assays, enhanced surveillance, and early treatment.

FUNDING

Bill & Melinda Gates Foundation.