Report of a Fatal Purulent Pericarditis Case Caused by ST11-K64 Carbapenem-Resistant Hypervirulent Klebsiella pneumoniae

Molecular Characterization and Risk Factors of Carbapenem-Resistant Hypervirulent Klebsiella pneumoniae Isolated from Chinese Tertiary Hospital

Background

Therefore, the objectives of this study were to investigate the prevalence of carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKp) in Fujian Medical University Union Hospital, identify their genetic characters, characterize their resistance profiles, and identify risk factors for their infection to improve prevention and treatment strategies for CR-hvKp in the area.

Methods

Between January 2021 and January 2022, clinically identified carbapenem-resistant Klebsiella pneumoniae (CRKp) isolates were collected. A PCR assay was used to detect the K capsule type, virulence genes, carbapenemase genes, and membrane pore protein. ERIC-PCR was carried out for homology analysis. Antimicrobial susceptibility test was used to determine drug resistance. Logistic multivariate regression analysis was conducted to confirm the risk factors for CR-hvKp infection.

Results

In total, 239 CRKp isolates were obtained. The virulence genes with the highest detection rates were mrkD, iucA, and rmpA2. Of these isolates, 54 (22.59%) carried both iucA and rmpA2, thus classifying them as CR-hvKp. All CR-hvKp isolates carried bla KPC. Furthermore, capsular serotypes K64 (94.44%) and K47 (3.70%) were detected. Resistance was observed against most common antibiotics, with the exception of complete sensitivity to ceftazidime-avibactam. ERIC-PCR indicated a potential clonal spread among CR-hvKp. Multivariate analysis found that changing beds was a risk factor for CR-hvKp infection.

Conclusion

Currently, the hospital predominantly carries K64 CR-hvKp that harbors the bla KPC. Our study found that changing patient beds was an independent risk factor for CR-hvKp infection.

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.

Endogenous Purulent Pericarditis Due to Klebsiella aerogenes in a Patient With Traumatic Chest Injury: A Case Report

Purulent pericarditis is a rare but serious medical condition caused by an infection that spreads to the pericardial space surrounding the heart. Gram-positive organisms are the most common pathogens associated with purulent pericarditis. However, there has been a shift in recent years toward gram-negative bacteria. Klebsiella aerogenes is a rare pathogen that has never been linked to purulent pericarditis. In this report, we describe the case of a 40-year-old male patient with chronic bronchiectasis who, two months after suffering an injury, developed purulent pericarditis due to an uncommon organism, K. aerogenes. During his stay in the hospital, the patient developed several infections caused by K. aerogenes. These included bacteremia and ventilator-associated pneumonia (VAP). Beta-lactamase-inducible K. aerogenes was grown in pericardial fluid culture following an emergency pericardiocentesis. The organism was resistant to carbapenems in a sputum culture, even though it was sensitive to meropenem in a blood culture. The patient had hypotension, requiring inotropes, and continued persistent bacteremia due to K. aerogenes. The patient had a heart attack with no pulse or electrical activity and died despite getting the best care possible. In light of this example, it is crucial to think about K. aerogenes and other rare organisms as possible pathogens in purulent pericarditis, especially in people who do not normally have known risk factors for this condition. Multidrug resistance patterns can make treatment more complicated, and aggressive care may be necessary in critically ill patients with chronic bacteremia.

"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.

Molecular Profiling of a Multi-Strain Hypervirulent Klebsiella pneumoniae Infection Within a Single Patient

Background

The rising prevalence of infections caused by carbapenem-resistant and hypervirulent Klebsiella pneumoniae (CR-hvKP) has outpaced our understanding of their evolutionary diversity. By straining the antimicrobial options and constant horizontal gene transfer of various pathogenic elements, CR-hvKP poses a global health threat.

Methods

Six KP isolates (KP1~KP6) from urine, sputum and groin infection secretion of a single patient were characterized phenotypically and genotypically. The antimicrobial susceptibility, carbapenemase production, hypermucoviscosity, serum resistance, virulence factors, MLST and serotypes were profiled. Genomic variations were identified by whole-genome sequencing and the phylogenetic differentiation was analyzed by Enterobacterial repetitive intergenic consensus (ERIC)-PCR.

Results

All KP strains were multi-drug resistant. Four of them (KP1, KP3, KP5 and KP6) belonged to ST11-K64, with high genetic closeness (relatedness coefficient above 0.96), sharing most resistance and virulence genes. Compared with KP1, the later isolates KP3, KP5 and KP6 acquired bla _KPC-1 and lost bla _SHV-182 genes. KP2 and KP4 had the same clonal origin of ST35-K16 (relatedness coefficient 0.98), containing almost identical genes for resistance and virulence. They were non-mucoid and carried bla _NDM-5 gene.

Conclusion

A co-infection with two types of CR-hvKP affiliated with different clades within a single patient amplified the treatment difficulties. In addition to source control and epidemiological surveillance, investigation of the in-host interactions between CR-hvKP variants may provide valuable treatment solutions.