Yanyan Liu’s research while affiliated with Chinese Center For Disease Control And Prevention and other places

Objective To identify the source of Clostridium botulinum (C. botulinum) involved in a food poisoning case in Kunming and analyze its molecular characteristics. Results This study examined samples from a clustered food poisoning incident, including pickled pig liver consumed by three patients, hospital vomit from a deceased patient, and household waste mixed with vomit. Enrichment culture, microscopic examination, and real-time quantitative PCR confirmed the presence of C. botulinum (designated KM001) with type E botulinum toxin. The full-length genomic sequence of this strain was obtained through second and third-generation sequencing, revealing a genome size of 3,713,470 bp. KEGG annotation indicated that 1,840 single genes were assigned to 44 KEGG pathways. Whole-genome sequencing revealed genetic diversity among toxin gene clusters, with 94.76% homology to C. botulinum E3 strain (Alaska E43) and 93.65% homology to C. botulinum B strain (Eklund 17B, NRP). Evolutionary analysis, incorporating complete genomes of foodborne and environmental C. botulinum strains worldwide along with KM001, showed stronger phylogenetic affinity of KM001 to other type E strains. Conclusion Overall, this study identified KM001 as the causative agent in a food poisoning incident, marking the first report of type E botulinum toxin poisoning in the region. Genomic analysis revealed the serotype and genetic diversity among toxin gene clusters, providing insights into its gene function, virulence, and evolutionary relationships. Understanding the genetic relationships and evolutionary pathways of different C. botulinum strains is crucial for predicting infection risks and implementing effective control measures.The findings contribute to the documentation of botulinum toxin incidents in Yunnan, China, but do not examine the antimicrobial resistance of C. botulinum or its interactions with other microorganisms; further research is needed to address these aspects.

In recent years, the avian influenza virus has emerged as a significant threat to both human and public health. This study focuses on a patient infected with the H10N3 subtype of avian influenza virus, admitted to the Third People’s Hospital of Kunming City on March 6, 2024. Metagenomic RNA sequencing and polymerase chain reaction (PCR) analysis were conducted on the patient’s sputum, confirming the H10N3 infection. The patient presented severe pneumonia symptoms such as fever, expectoration, chest tightness, shortness of breath, and cough. Phylogenetic analysis of the Haemagglutinin (HA) and neuraminidase (NA) genes of the virus showed that the virus was most closely related to a case of human infection with the H10N3 subtype of avian influenza virus found in Zhejiang Province, China. Analysis of amino acid mutation sites identified four mutations potentially hazardous to human health. Consequently, this underscores the importance of continuous and vigilant monitoring of the dynamics surrounding the H10N3 subtype of avian influenza virus, utilizing advanced genomic surveillance techniques.

In recent years, the avian influenza virus has emerged as a significant threat to both human and public health. Despite this, only two cases of human infection with the H10N3 strain have been documented. Here, we present the initial instance of human infection with avian influenza virus H10N3 in Yunnan Province, Southwest China. The patient, a previously healthy 51-year-old male, presented with recurrent fever peaking at 39℃, accompanied by symptoms such as cough, expectoration, chest tightness, and shortness of breath. Diagnosis revealed severe pneumonia, type I respiratory failure, and infection with avian influenza virus H10N3. Additionally, the patient experienced complications from Candida albicans and Staphylococcus epidermidis infections. Following treatment with appropriate antiviral drugs and antibiotics, the patient's condition improved. Molecular analysis of the viral strain identified four mutations potentially hazardous to human health. This underscores the importance of continuous and vigilant monitoring of the dynamics surrounding the H10N3 subtype of avian influenza virus.