Pyogenic spondylitis caused by Klebsiella pneumoniae: should the possibility of hypervirulent Klebsiella pneumoniae be considered?

Analysis of clinical and microbiological characteristics of invasive Klebsiella pneumoniae liver abscess syndrome

BACKGROUND

Invasive Klebsiella pneumoniae liver abscess syndrome (IKPLAS) is emerging as a new disease worldwide, threatening human health. This study aimed to investigate the clinical and microbiological features of IKPLAS in order to detect this syndrome early and select antibiotics appropriately.

METHODS

Medical data from patients in Tongji Hospital, China, diagnosed with Klebsiella pneumoniae liver abscess (KPLA) between 2015 and 2023 was collected and analyzed retrospectively.

RESULTS

The study included 208 patients with KPLA, 41 with IKPLAS, and 167 with non-IKPLAS (NIKPLAS). Multivariate logistic regression analysis demonstrated that symptoms in other organ systems (including ocular, pulmonary, and neurological symptoms) (p = 0.001) and a sequential organ failure assessment (SOFA) score ≥ 4 within 48 h of admission (P = 0.002) were significant risk factors for IKPLAS. Patients with IKPLAS had a higher risk of developing multiple organ dysfunction (MODS), and a PCT ≥ 10 ng/mL was identified as an independent risk factor for MODS (p = 0.01). IKPLAS was associated with significantly prolonged hospital stays and unfavorable outcomes (all p < 0.05). There were no significant differences in microbiological characteristics between IKPLAS and NIKPLAS, including the antimicrobial susceptibility pattern and resistance profile of Klebsiella pneumoniae (KP) (all p > 0.05). In this study, KP isolates were susceptible to most antibiotics, with low rates of drug resistance. Specifically, a total of five carbapenem-resistant strains (2.6%) and seven multidrug-resistant strains (3.6%) were detected, all of which were derived from the NIKPLAS group.

CONCLUSIONS

Symptoms in other organ systems and the SOFA score ≥ 4 within 48 h of admission were significant predictors for IKPLAS. This study elucidated the antimicrobial susceptibility profile of liver abscess-associated KP strains, providing a reference for the early initiation of rational and effective antimicrobial therapy in patients with KPLA.

Gram-negative rods are associated with prolonged treatment in patients with thoracolumbar pyogenic spondylitis after minimally invasive posterior fixation compared with gram-positive cocci: a multicenter retrospective cohort study

BACKGROUND

This study compared patient characteristics, clinical outcomes, and antibiotic durations between patients undergoing posterior fixation for gram-negative rods (GNR) or gram-positive cocci (GPC) thoracolumbar pyogenic spondylitis.

METHODS

In this multicenter retrospective cohort study, 53 patients who underwent minimally invasive posterior fixation for thoracolumbar pyogenic spondylitis were categorized into a GPC or GNR group based on the identified causative organisms. Patient characteristics, surgical outcomes, and postoperative infection control were compared between the two groups to identify factors affecting antibiotic duration.

RESULTS

The patients in the GNR group (n = 14) were older (77.2 years versus 70.1 years; p = 0.008), had a higher incidence of a history of abdominal-pelvic infections (4 versus 0; p = 0.003), required longer preoperative antibiotics (5.9 weeks versus 3.0 weeks; p = 0.035), and had more unplanned additional surgeries due to poor infection control (n = 4 versus n = 1; p = 0.014) than those in the GPC group (n = 39). Furthermore, GNR infection independently predicted longer preoperative antibiotic duration (p = 0.002, β = 0.43).

CONCLUSIONS

Pyogenic spondylitis with GNR is associated with the need for prolonged antibiotic treatment and higher rates of unplanned additional surgeries due to poor infection control as compared to GPC-associated pyogenic spondylitis. Older age and a history of abdominal-pelvic infections tend to complicate the management in these patients; therefore, tailored treatment strategies are required to optimize treatment duration and minimize complications.

CLINICAL TRIAL NUMBER

Not applicable.

Community-Acquired Solitary Brain Abscesses Caused by Hypervirulent Klebsiella pneumoniae in a Healthy Adult

A 42-year-old man was admitted to the emergency room complaining of fever and headache. His cerebrospinal fluid showed a cloudy appearance, and his white blood cell count was elevated at 2460/mm3, with a predominance of neutrophils (81%), and abnormal protein and glucose levels (510.7 mg/dL and 5 mg/dL, respectively). A lobulated lesion with rim enhancement, suggestive of abscess, was detected through magnetic resonance imaging. Klebsiella pneumoniae was detected in nasopharyngeal swab and blood cultures. The capsular serotype of K. pneumoniae was K2 and the sequence type determined by multilocus sequence typing was 23. The hypervirulent phenotype was associated with multiple virulent genes, including rmpA, rmpA2, entB, ybtS, kfu, iucA, iutA, iroB mrkD, allS, peg-344, peg-589, and peg-1631. After six weeks of receiving appropriate antibiotics and exhibiting clinical resolution of the brain abscesses, the patient was discharged. We present the first reported case of a healthy community-dwelling adult with solitary brain abscesses, and no other invasive abscesses, related to hypervirulent K. pneumoniae.

[Carbapenemase Genes, Virulence Genes, and Molecular Epidemiology of Carbapenem-Resistant Klebsiella pneumoniae Derived From Bloodstream Infections]

Objective

To investigate the clinical characteristics and molecular epidemiology of carbapenem-resistant Klebsiella pneumoniae (CRKP) isolated from patients with bloodstream infections in a large tertiary-care general hospital in Southwest China.

Methods

A total of 131 strains of non-repeating CRKP were collected from the blood cultures of patients who had bloodstream infections in 2015-2019. The strains were identified by VITEK-2, a fully automated microbial analyzer, and matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. The minimum inhibitory concentration (MIC) was determined by microbroth dilution method. The common carbapenemase resistant genes and virulence factors were identified by PCR. Homology analysis was performed by multilocus sequencing typing. Whole genome sequencing was performed to analyze the genomic characteristics of CRKP without carbapenemase.

Results

The 131 strains of CRKP showed resistance to common antibiotics, except for polymyxin B (1.6% resistance rate) and tigacycline (8.0% resistance rate). A total of 105 (80.2%) CRKP strains carried the Klebsiella pneumoniae carbapenemase (KPC) resistance gene, 15 (11.4%) strains carried the New Delhi Metallo-β-lactamase (NDM) gene, and 4 (3.1%) isolates carried both KPC and NDM genes. Sequence typing (ST) 11 (74.0%) was the dominant sequence type. High detection rates for mrkD (96.2%), fimH (98.5%), entB (100%), and other virulence genes were reported. One hypervirulent CRKP strain was detected. The seven strains of CRKP that did not produce carbapenemase were shown to carry ESBL or AmpC genes and had anomalies in membrane porins OMPK35 and OMPK36, according to whole genome sequencing.

Conclusion

In a large-scale tertiary-care general hospital, CRKP mainly carries the KPC gene, has a high drug resistance rate to a variety of antibiotics, and possesses multiple virulence genes. Attention should be paid to CRKP strains with high virulence.