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PubMed2026

Description and genomic characterization of Aquipuribacter aurantiacus sp. nov., isolated from saline lake sediment.

Strains MA13-6T and MA13-13, two Gram-stain-positive, aerobic, short rod-shaped actinobacteria, were isolated from a saline lake in Ngari Prefecture, Xizang Autonomous Region, China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that these two strains belonged to the genus Aquipuribacter, with the closest relationship to Aquipuribacter hungaricus IV-75T (98.47% sequence similarity) and Aquipuribacter nitratireducens AMV4T (97.36% sequence similarity). Phylogenetic analysis based on genomes further confirmed their classification as a distinct cluster within the genus Aquipuribacter. The average nucleotide identity and digtal DNA-DNA hybridization values between these two strains and their closest relative Aquipuribacter hungaricus IV-75T, were 82.44-82.49% and 23.00%, respectively, clearly indicating that strains MA13-6T and MA13-13 represent a novel species. The 16S rRNA gene sequence similarity, average nucleotide identity and digital DNA-DNA hybridization values between these two strains were 99.79%, 99.97% and 99.40%, respectively, unequivocally confirming their classification within the same species. However, DNA fingerprinting analysis distinguished them as non-clonal variants. The polar lipids comprised phosphatidylglycerol, two unidentified phospholipids, two unidentified glycolipids, and two unidentified lipids. The predominant respiratory quinone was MK-10 (H4). The major fatty acids were anteiso-C15:0, C18:1ω9c, isoC16:0 and anteiso-C17:0. The cell wall diagnostic diamino acid was meso-diaminopimelic acid. Based on phylogenetic analyses combined with phenotypic and chemotaxonomic characterization, strains MA13-6T and MA13-13 represent a novel species of the genus Aquipuribacter, for which the name Aquipuribacter aurantiacus sp. nov. is proposed. The type strain is MA13-6T (=MCCC 1K10045T = KCTC 59572T).

Phylogeny↗

PubMed2026

Tracing and characterization of a family outbreak of subtype B2 botulism linked to homemade pickled eggs in Jinan, China.

Foodborne botulism (FB) results from the ingestion of food contaminated with botulinum neurotoxin. Here, we report a family outbreak of foodborne botulism caused by Clostridium botulinum subtype B2 linked to homemade pickled eggs. On August 13, 2024, the Jinan Center for Disease Control and Prevention and the Shanghe County Center for Disease Control and Prevention collaborated to investigate an outbreak of botulism poisoning related to a family gathering in Shanghe County, Jinan City. A total of 4 people attended the family gathering, three of whom developed clinical symptoms of botulism after consuming pickled eggs. The diagnosis of botulism was suspected through collaborative efforts by the Qilu Medical Prevention and Control Innovation Integration Mechanism and multidisciplinary consultations across multiple hospitals. We detected the bont gene using real-time quantitative PCR (qPCR) in Jinan CDC, determined the toxin serotype by mouse bioassay (MBA) in China CDC and performed whole-genome sequencing of bacterial strains isolated from patient feces, the homemade pickled eggs and soil in both laboratories. It was shown that the toxin type and bont gene were subtype B2, belonging to the ha gene cluster. The Clostridium botulinum strains isolated from two patients were closely related to the strains from the homemade pickled eggs through whole-genome single nucleotide polymorphism analysis. We also found that Clostridium botulinum strains from soil clustered into one branch with those from patients and food, suggesting that the source of Clostridium botulinum contamination may be from soil, although the contamination pathway was not clear. Importantly, our findings provided a basis for clinical antitoxin treatment, in which one patient successfully gave birth after recovery. These results underscore the importance of strengthening public education about the health risks associated with consuming homemade fermented or preserved foods and enhancing the laboratory detection capabilities.

Botulism↗