To investigate the molecular typing, virulence and antimicrobial resistance characteristics of food-borne Klebsiella pneumoniae in Guizhou Province, providing scientific evidence for targeted food safety risk assessment and regulatory decision-making in our province.
A total of 38 strains of Klebsiella pneumoniae were isolated from pre-packaged chilled ready-to-eat food and pig livers in 9 cities (states) of Guizhou Province from 2023 to 2024. Strains were screened by string test, whole genome sequencing and antimicrobial susceptibility test.
Four hypermucoviscous Klebsiella pneumoniae strains were isolated from 38 isolates. Through whole genome sequence analysis, 20 KL types, 30 ST types, 80 virulence genes and 35 drug resistance genes were obtained. ST 37 was the main strain. HmKp of ST65-KL2 carried iucA, iroB, ybtS, rmpA and clb genes, while ST490-KL3 carried iucA, iroB, ybtS and allS genes. The main β-lactamase resistance genes were blaSHV-11, blaSHV-1, blaLAP-2. 5 of the strains carried blaOXA-10 gene. The results of antibiotic susceptibility tests showed that the top five resistant antibiotics were ampicillin, tetracycline, chloramphenicol, florfenicol and sulfamethoxazole/trimethoprim, with resistance rates of 81.58%, 50.0%, 44.74%, 44.74% and 28.95% respectively. All isolates were sensitive to carbapenems.
The prevalence of virulence genes in Klebsiella pneumoniae in food in Guizhou Province is high, with a strong pathogenic potencial. The ST types and KL types of the strains are diverse.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |