Novel complication of an emerging disease: Invasive Klebsiella pneumoniae liver abscess syndrome as a cause of acute respiratory distress syndrome

Genetic Characterization of Carbapenem-Resistant Klebsiella pneumoniae Clinical Isolates in a Tertiary Hospital in Greece, 2018-2022

BACKGROUND

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a serious public health issue. The study aimed to identify the antimicrobial resistance and accessory genes, the clonal relatedness, and the evolutionary dynamics of selected CRKP isolates recovered in an adult and pediatric intensive care unit of a tertiary hospital in Greece.

METHODS

Twenty-four CRKP isolates recovered during 2018-2022 were included in the study. Next-generation sequencing was performed using the Ion Torrent PGM Platform. The identification of the plasmid content, MLST, and antimicrobial resistance genes, as well as the comparison of multiple genome alignments and the identification of core genome single-nucleotide polymorphism sites, were performed using various bioinformatics software.

RESULTS

The isolates belonged to eight sequence types: 11, 15, 30, 35, 39, 307, 323, and 512. A variety of carbapenemases (KPC, VIM, NDM, and OXA-48) and resistance genes were detected. CRKP strains shared visually common genomic regions with the reference strain (NTUH-K2044). ST15, ST323, ST39, and ST11 CRKP isolates presented on average 17, 6, 16, and 866 recombined SNPs, respectively. All isolates belonging to ST15, ST323, and ST39 were classified into distinct phylogenetic branches, while ST11 isolates were assigned to a two-subclade branch. For large CRKP sets, the phylogeny seems to change approximately every seven SNPs.

CONCLUSIONS

The current study provides insight into the genetic characterization of CRKP isolates in the ICUs of a tertiary hospital. Our results indicate clonal dispersion of ST15, ST323, and ST39 and highly diverged ST11 isolates.

Klebsiella pneumoniae invasion syndrome: a case of liver abscess combined with lung abscess, endophthalmitis, and brain abscess

Klebsiella pneumoniae invasion syndrome (KPIS) is a critical multi-site infection that is usually caused by highly virulent Klebsiella pneumonia. It is relatively common in Asian patients with diabetes and leads to sepsis, which has a high mortality rate. We report the case of a man in his early 40s who presented to the hospital with blurred vision in his left eye of 7 days’ duration and fever of 1 day’s duration. After a complete examination, he was diagnosed with KPIS on the basis of his liver abscessation, lung abscessation, endophthalmitis of the left eye and brain abscessation. After needle puncture and drainage of the left eye and liver abscess and anti-bacterial treatment with meropenem, the patient recovered well. When KPIS is suspected, attention should be paid to the sites of infection and the selection of the most appropriate antibiotics, but the most important aim should be to drain the lesions in a timely manner to improve the patient’s prognosis.

Clinical features and development of Sepsis in Klebsiella pneumoniae infected liver abscess patients: a retrospective analysis of 135 cases

Background

Klebsiella pneumoniae is a primary pathogen of pyogenic liver abscess (PLA). However, little data are available on combination with sepsis. In this study, we aimed to evaluate the clinical characteristics and prognostic differences of PLA patients with sepsis.

Methods

This retrospective cohort study was conducted to investigate 135 patients with confirmed Klebsiella pneumoniae-caused liver abscesses (KPLA) from a tertiary teaching hospital, from 2013 to 2019. The patients were divided into two groups, KPLA with sepsis and KPLA without sepsis. The demographic characteristics, clinical features as well as laboratory and microbiologic findings were analyzed.

Results

A total of 135 patients with KPLA were analyzed. The mean age of patients was 60.9 ± 12.7 years, and the percentage of men was 59.3%. Among them, 37/135 (27.4%) of patients had sepsis and the mortality rate was 1.5%. The most common symptom was fever (91.1%). KPLA patients with sepsis had a significantly higher proportion of frailty, diarrhea, fatty liver, chronic renal insufficiency, and hepatic dysfunction compared to KPLA patients without sepsis (p < 0.05). Antibiotic therapy and percutaneous drainage were most frequently therapeutic strategy. Furthermore, the incidences of sepsis shock and acute respiratory distress syndrome were higher in the sepsis group compared to the non-sepsis group. As for metastatic infections, the lung was the most common site. In addition, KPLA patients with sepsis showed respiratory symptoms in 11 patients, endophthalmitis in 4 patients, and meningitis in 1 patient.

Conclusion

Our findings emphasize that KPLA patients combined with or without sepsis have different clinical features, but KPLA patients with sepsis have higher rates of complications and metastatic infections. Taken together, further surveillance and control of septic spread is essential for KPLA patients.

Small Klebsiella pneumoniae Plasmids: Neglected Contributors to Antibiotic Resistance

Klebsiella pneumoniae is the causative agent of community- and, more commonly, hospital-acquired infections. Infections caused by this bacterium have recently become more dangerous due to the acquisition of multiresistance to antibiotics and the rise of hypervirulent variants. Plasmids usually carry genes coding for resistance to antibiotics or virulence factors, and the recent sequence of complete K. pneumoniae genomes showed that most strains harbor many of them. Unlike large plasmids, small, usually high copy number plasmids, did not attract much attention. However, these plasmids may include genes coding for specialized functions, such as antibiotic resistance, that can be expressed at high levels due to gene dosage effect. These genes may be part of mobile elements that not only facilitate their dissemination but also participate in plasmid evolution. Furthermore, high copy number plasmids may also play a role in evolution by allowing coexistence of mutated and non-mutated versions of a gene, which helps to circumvent the constraints imposed by trade-offs after certain genes mutate. Most K. pneumoniae plasmids 25-kb or smaller replicate by the ColE1-type mechanism and many of them are mobilizable. The transposon Tn1331 and derivatives were found in a high percentage of these plasmids. Another transposon that was found in representatives of this group is the bla KPC-containing Tn4401. Common resistance determinants found in these plasmids were aac(6')-Ib and genes coding for β-lactamases including carbapenemases.

Prognosis of liver abscess with no identified organism

BACKGROUND

There are limited studies focusing on liver abscess with negative microbiological cultures. This study evaluated the clinical and prognostic differences of patients with culture-negative liver abscess (CNLA) compared to those with a positive culture (CPLA) and compared these factors between K. pneumoniae liver abscess (KLA) and E. coli liver abscess (ELA).

METHODS

A retrospective study of the patients who admitted with a liver abscess at two tertiary hospitals in Korea from 2012 to 2016 was performed.

RESULTS

Among a total of 402 patients with liver abscess, 61.2% had positive cultures. K. pneumoniae (n = 133) was the most common cause, followed by E. coli (n = 74). Patients with CPLA were significantly older (p = 0.02) and more frequently had cholelithiasis or biliary tract disease (p = 0.001) compared to patients with CNLA. In-hospital mortality (p = 0.63) and recurrence (p = 0.77) were no different between the two groups. The length of hospital stay was significantly longer in patients with CPLA (p = 0.03) compared with those with CNLA. Subgroup analysis for patients who received 3rd generation cephalosporins empirically showed that in-hospital mortality (p = 0.18) and recurrence (p = 0.27) were not also significantly different. Cholelithiasis, or biliary tract disease (p = 0.001), liver disease (p = 0.001), malignancy (p = 0.0001), and ESBL production (p = 0.0001) were found more frequently in patients with ELA compared with those with KLA.

CONCLUSIONS

The prognosis of the CNLA patients was similar to that of the CPLA patients, although the length of hospital stay was shorter in the CNLA patients. The epidemiologic and clinical characteristics of the ELA patients are somewhat different than those of the KLA patients.