[Molecular epidemiological characterization of hypervirulent carbapenem-resistant Klebsiella pneumoniae in a hospital in Henan Province from 2020 to 2022].

Objective: The study investigated the clinical distribution, antimicrobial resistance and epidemiologic characteristics of hypervirulent Carbapenem-resistant Klebsiella pneumoniae (hv-CRKP) in a hospital in Henan Province to provide a scientific basis for antibiotic use and nosocomial infection prevention and control. Methods: A retrospective analysis of the clinical data from the cases was carried out in this study. Clinical data of patients infected with the CRKP strain isolated from the clinical microbiology laboratory of Henan Provincial Hospital of Traditional Chinese Medicine from January 2020 to December 2022 were retrospectively analyzed. A string test, virulence gene screening, serum killing, and a G. mellonella infection model were used to screen hv-CRKP isolates. The clinical characteristics of hv-CRKP and the drug resistance rate of hv-CRKP to twenty-five antibiotics were analyzed using WHONET 5.6. Carbapenemase phenotypic characterization of the hv-CRKP was performed by colloidal gold immunochromatographic assay, and Carbapenemase genotyping, multi-locus sequence typing (MLST) and capsular serotyping of hv-CRKP isolates were performed by PCR and Sanger sequencing. Results: A total of non-duplicate 264 CRKP clinical isolates were detected in the hospital from 2020 to 2022, and 23 hv-CRKP isolates were detected, so the corresponding detection rate of hv-CRKP was 8.71% (23/264). The hv-CRKP isolates in this study were mainly from the intensive care unit (10/23) and neurosurgery department (8/23), and the main sources of hv-CRKP isolates were sputum (10/23) and bronchoalveolar lavage fluid (6/23). The hv-CRKP isolates in this study were highly resistant to ß-lactam antibiotics, fluoroquinolones and aminoglycosides, and were only susceptible to colistin, tigecycline and ceftazidime/avibactam. The detection rate of the blaKPC-2 among 23 hv-CRKP isolates was 91.30% (21/23) and none of the class B and class D carbapenemases were detected. Results of MLST and capsular serotypes showed that ST11 type hv-CRKP was the dominant strain in the hospital, accounting for 56.52% (13/23), and K64 (9/13) and KL47 (4/13) were the major capsular serotypes. Conclusion: The hv-CRKP isolates from the hospital are mainly from lower respiratory tract specimens from patients admitted to the intensive care department and the drug resistance is relatively severe. The predominant strains with certain polymorphisms are mainly composed of the KPC-2-producing ST11-K64 and ST11-KL47 hv-CRKP isolates in the hospital.

[Sensitization characteristics of Juniperus chinensis pollen in Beijing area].

Objective: To investigate the sensitization characteristics of Juniperus chinensis pollen in patients with allergic rhinitis and/or allergic asthma in Beijing area, and to explore the characteristics of Juniper chinensis pollen sensitized population. Methods: Patients with suspected allergic rhinitis and/or asthma from January 2017 to December 2019 in the outpatient department of Allergy Department of Beijing Shijitan Hospital were selected in this study. Skin prick test (SPT) was performed with Juniper chinensis pollen allergen reagent to compare different age and disease allergen distribution, and to observe the sensitization characteristics of its population. All of the analyses were performed using SAS software version 9.4. Results: A total of 8 380 patients were enrolled in the end. The total positive rate of Juniper chinensis pollen SPT reached 49.92% (4 183/8 380). The positive rate of Juniper chinensis pollen SPT was highest in the 10-14 age group, reaching 60.99% (283/464). Compared with other age groups, there was a statistical difference (χ²=266.77, P<0.01). The SPT positive rate of patients aged less than 10 years increased with the increase of age, while the SPT positive rate of patients aged over 40 years decreased with the increase of age. Single Juniper chinensis pollen was less allergenic, accounting for about 25.05% (1 048/4 183), and the patients' age was (35.21±12.39) years. Regardless of single Juniper chinensis pollen or other pollen allergies, allergic rhinitis was the main disease. Among the patients with SPT positive Juniper chinensis pollen combined with other inhaled pollen allergens, willow pollen accounted for the first (74.99%). The positive rate of Juniper chinensis pollen was the highest in patients with single allergic rhinitis, accounting for 52.05% (3 797/7 295), and the rate in patients with single allergic asthma was the lowest, accounting for 17.49% (53/303), with statistically difference (χ²=138.99, P<0.01). Conclusions: Juniper chinensis pollen is highly sensitized in patients with allergic rhinitis and/or allergic asthma in Beijing . The positive rate of SPT is highest among 10-14 age group, most of which showed strong positive reaction, and allergic rhinitis is more common in Juniper chinensis pollen sensitization diseases.