Emerging Prevalence and Clinical Features of Elizabethkingia meningoseptica Infection in Southwest China: A 9-Year Retrospective Study and Systematic Review

Mortality Risk and Antibiotic Therapy for Patients with Infections Caused by Elizabethkingia Species-A Meta-Analysis

Background and Objectives: Patients with infections caused by Elizabethkingia species require prompt identification and effective antibiotic treatment since these spp. are typically resistant to multiple antibiotics and variable susceptibility patterns. Understanding the mortality risk of this disease is difficult because of the relatively low incidence of infections caused by Elizabethkingia spp. and the lack of published systematic evaluations of the risk factors for mortality. The aim of the present study was to investigate risk factors for mortality in patients with infections caused by Elizabethkingia spp. by conducting a meta-analysis of existing studies on these infections. Materials and Methods: Studies comparing patients who died from infections caused by Elizabethkingia spp. with patients who survived were considered for inclusion. Studies that reported one or more risk factors for mortality were considered. Clinical predisposing variables, predisposing comorbidities, and clinical outcomes of antibiotic treatment were among the risk factors for mortality. Results: The meta-analysis included twenty studies with 990 patients, and 298 patients (30.1%) died. The following risk factors for mortality were identified: intensive care unit admission, the need for mechanical ventilation, immunosuppressive or steroid therapy use, pneumonia, comorbid liver disease, and the use of inappropriate antimicrobial therapy. Conclusions: The use of appropriate antimicrobial therapy is critical for the effective management of infections caused by Elizabethkingia spp. Antimicrobial susceptibility testing would be a more reliable means of guiding treatment. The identification of the best antimicrobial drugs is needed to ensure optimal treatment recommendations for treating Elizabethkingia-related infections.

Epidemiology, clinical profiles, and antimicrobial susceptibility of Elizabethkingia meningoseptica infections: Insights from a tertiary care hospital in Saudi Arabia

OBJECTIVES

To investigate the incidence rate, clinical characteristics across different age groups, antimicrobial susceptibility, and outcomes of Elizabethkingia meningoseptica (E. meningoseptica) infections.

METHODS

A retrospective analysis was carried out to include 66 cases with confirmed E. meningoseptica cultures from sterile samples between January 2014 and June 2022 at King Faisal Specialist Hospital and Research Centre in Riyadh, Saudi Arabia.

RESULTS

A total of 66 cases were identified, with an incidence rate of 0.3 per 1000 admissions. Most cases were hospital-acquired (80.3%), primarily in critical care areas. All patients had underlying diseases, with respiratory (40.9%) and cardiovascular (39.4%) diseases being the most common. Minocycline showed the highest susceptibility (96.0%), followed by trimethoprim/sulfamethoxazole (77.0%), whereas tobramycin and colistin were fully resistant. The in-hospital mortality rate was 34.8%, whereas the 28-day mortality rate was 22.7%. Clinical characteristics across age groups showed a higher prevalence of cardiovascular disease in pediatrics than in adults, whereas exposure to mechanical ventilation, immunosuppressive therapy, previous infection, anemia, and in-hospital mortality were reported more frequently in adults (p<0.05).

CONCLUSION

Our study provides valuable insights into E. meningoseptica infection in Saudi Arabia, emphasizing the importance of robust infection control measures. Incidence and mortality rates align with global trends. Variations in clinical characteristics across age groups highlight the importance of tailored treatments based on patient demographics and underlying comorbidities.

Identification of novel Tet(X6)-Tet(X2) recombinant variant in Elizabethkingia meningoseptica from a bullfrog farm and downstream river in China

Introduction

The dissemination of strains producing tetracyclines monooxygenase Tet(X) from breeding farms to the natural environment poses a potential threat to public health.

Methods

Antimicrobial susceptibility testing and WGS were performed to identify resistance phenotypes and genotypes. Cloning experiments, sequence alignment, and homology modeling were used to characterize the function and formation mechanisms of the recombinant variant. The mobilization potential of Tet(X) was assessed by collinearity analysis, conjugation experiments, and phylogenetic analysis.

Results

Three tet(X)-producing Elizabethkingia meningoseptica strains were isolated from bullfrog breeding ponds, the sewage outlet, and downstream river in Zhejiang Province, China. These strains carry a novel Tet(X) variant, differing from Tet(X6) by seven residues, and possess the ability to degrade tetracyclines. Interestingly, the novel Tet(X) is a recombinant variant formed by homologous recombination of Tet(X6) and the C-terminal of Tet(X2). Further analysis revealed that Tet(X6) formed several Tet(X) variants, including Tet(X5), through homologous recombination. The novel tet(X) gene is located on a circularizable integrative and conjugative element (ICEEmeChn3), with ISwz1 participating in the recombination of its multi-drug resistance region, potentially facilitating the mobilization and recombination of tet(X) in early hosts. These three strains were clonally transmitted and shared a close genetic relationship (SNP < 62) with a clinically-sourced strain isolated from the same province.

Discussion

To our knowledge, this is the first report of homologous recombination between Tet(X) variants with differing activities. These clonal strains provide evidence of the transmission of tet(X)-positive strains from aquaculture sewage to the natural environment, highlighting the need to strengthen the monitoring and management of this emerging farming model.

Clinical and microbiological features of positive blood culture episodes caused by non-fermenting gram-negative bacilli other than Pseudomonas and Acinetobacter species (2020-2023)

INTRODUCTION

Non-fermenting Gram-negative bacilli (NFGNB) other than Pseudomonas aeruginosa and Acinetobacter baumannii complex are pathogens of interest due to their ability to cause health-care associated infections and display complex drug resistance phenotypes. However, their clinical and microbiological landscape is still poorly characterized.

METHODS

Observational retrospective study including all hospitalized patients presenting with a positive positive blood culture (BC) episode caused by less common NFGNB over a four-year period (January 2020-December 2023). Clinical-microbiological features and factors associated with mortality were investigated.

RESULTS

Sixty-six less common NFGNB isolates other than Pseudomonas and Acinetobacter species causing 63 positive BC episodes were recovered from 60 patients. Positive BC episodes were predominantly sustained by Stenotrophomonas maltophilia (49.2%) followed by Achromobacter species (15.9%) that exhibited the most complex resistance phenotype. Positive BC episodes had bloodstream infection criteria in 95.2% of cases (60 out 63), being intravascular device (30.2%) and respiratory tract (19.1%) the main sources of infection. Fourteen-day, 30-day, and in-hospital mortality rates were 6.4%, 9.5%, and 15.9%, respectively. The longer time from admission to the positive BC episode, older age, diabetes, admission due to sepsis, and higher Charlson Comorbidity Index were identified as the main predictors of in-hospital mortality.

CONCLUSIONS

Positive BC episodes sustained by NFGNB other than Pseudomonas and Acinetobacter species were predominantly sustained by Stenotrophomonas maltophilia and Achromobacter species, having bloodstream infection criteria in the vast majority of cases. Factors that have emerged to be associated with mortality highlighted how these species may have more room in prolonged hospitalisation and at the end of life for patients with chronic organ diseases.

A case of Elizabethkingia meningoseptica septicemia

A 82-year-old man was admitted to hospital with fever, unresponsiveness, elevated hypersensitive C-reactive protein and neutrophile granulocyte. Ceftriaxone was administrated by intravenous dripping in the emergency room, but the effect was not satisfactory. Following his admission to the ward, cefoperazone sulbactam were given. Elizabethkingia meningoseptica was identified by blood culture and further confirmed by 16S rRNA sequencing. The lumbar puncture showed that cerebrospinal fluid pressure was 80 mmH2O (1 mmH2O=0.0098 kPa) and biochemical results were normal. After 11 days of cefoperazone sulbactam treatment, the patient was discharged with negative blood culture. The hypersensitive C-reactive protein and neutrophile granulocyte had also declined. The patient received levofloxacin tablets for anti-infection treatment for 14 d after discharge. No signs of infection were observed in three months' following up.

Current viewpoint on the epidemiology of nonfermenting Gram-negative bacterial strains

PURPOSE OF REVIEW

This article aims to review the epidemiology of nonfermenting Gram-negative bacilli (NFGNB) based on recent literature reports, particularly, of the less common, but with emerging clinical significance species.

RECENT FINDINGS

The reported frequency of multidrug-resistant Acinetobacter baumannii and Pseudomonas aeruginosa is increasing, with very significant variability, however, between different countries. Apart from the major NFGNB, that is, A. baumannii and P. aeruginosa, already recognized as of critical importance healthcare risks, several other NFGNB genera have been increasingly associated with diverse severe infections, such as Stenotrophomonas maltophilia, Burkholderia spp., Elizabethkingia spp., Chryseobacterium spp., Achromobacter spp., Alcaligenes spp., Sphingomonas spp., Shewanella spp. and Ralstonia spp., among others.

SUMMARY

The exploration of the epidemiology, as well as the pathogenic potential of the of the less frequent, but emerging and increasingly reported NFGNB, is crucial, not only for immunocompromised patients, but also for critically ill patients without overt immunosuppression. As we are heading fast towards a postantibiotic era, such information would contribute to the optimal antimicrobial management, that is, providing prompt, appropriate antimicrobial coverage when needed and, at the same time, avoiding overuse and/or inappropriate use of antimicrobial therapy. Also, it would help to better understand their transmission dynamics and to develop effective prevention strategies.