From buffalo to human: Klebsiella pneumoniae in high-somatic cell count milk as an overlooked link in the one health chain.

Zhifei Wei; Yifei Xiang; Xuelian Mo; Wenjing Li; Erqiang Wang; Changhua Lin; Jiazhou Wei; Yulian Xi; Yuying Liao; Zhengmin Liang; Zhiran Xu; Jiakang He

doi:10.1016/j.ijfoodmicro.2026.112027

PubMed · 42667764

From buffalo to human: Klebsiella pneumoniae in high-somatic cell count milk as an overlooked link in the one health chain.

Zhifei Wei·Yifei Xiang·Xuelian Mo·Wenjing Li·Erqiang Wang·Changhua Lin·Jiazhou Wei·Yulian Xi·Yuying Liao·Zhengmin Liang·Zhiran Xu·Jiakang He

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Abstract

High somatic cell count (SCC) is a critical indicator of udder health and milk quality in buffalo milk production. However, in many low-income regions, SCC monitoring is often underemphasized, allowing a proportion of high-SCC buffalo milk to enter the food chain and potentially compromising food safety and public health. Klebsiella pneumoniae (K. pneumoniae) is a common zoonotic pathogen found in high-SCC milk, yet systematic investigations into the prevalence and characteristics in high-SCC buffalo milk remain limited. In this study, 23 K. pneumoniae strains were screened out from 460 bacterial isolates obtained from high-SCC buffalo milk samples from Guangxi, China, with an isolation rate of 5.0%. These isolates were comprehensively characterized using whole-genome sequencing and comparative genomic analyses. The results revealed that 78.26% (18/23) of the isolates shared high genomic similarity with the human reference strain ATCC 13883, and the ST37 clone exhibited a pronounced potential of cross-species transmission. All isolates harbored core adhesion factors and intrinsic resistance genes. Notably, several strains displayed high-risk features: strain 419 carried the K1 capsular serotype, strain 326 possessed a complete yersiniabactin synthesis gene cluster, and strain 320 exhibited a multidrug-resistant phenotype. Phenotypic assays further demonstrated a positive correlation between biofilm formation capacity and virulence in Galleria mellonella. Metabolic pathway enrichment analyses suggested that K. pneumoniae has undergone substantial adaptation to the nutrient-rich buffalo milk environment. Collectively, these findings confirm that raw high-SCC buffalo milk serves as a significant reservoir for high-risk zoonotic K. pneumoniae. While industrial thermal processing effectively eliminates viable pathogens, the resilient antimicrobial resistance determinants within these isolates pose a persistent risk of horizontal gene dissemination along the food chain, providing critical evidence for enhancing pre-processing milk quality regulations within a One Health framework.

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Animals Buffaloes Klebsiella pneumoniae Milk Humans Klebsiella Infections China Cell Count Anti-Bacterial Agents Drug Resistance, Multiple, Bacterial Food Microbiology Dairy water buffalo milk Food safety Genomics High somatic cell count Journal Article

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Zhifei Wei, Yifei Xiang, Xuelian Mo, Wenjing Li, Erqiang Wang, Changhua Lin, Jiazhou Wei, Yulian Xi, Yuying Liao, Zhengmin Liang, Zhiran Xu, Jiakang He. 2026-08-26. From buffalo to human: Klebsiella pneumoniae in high-somatic cell count milk as an overlooked link in the one health chain.. https://doi.org/10.1016/j.ijfoodmicro.2026.112027

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Journal Article resource Animals subject Anti-Bacterial Agents subject Buffaloes subject Cell Count subject China subject Dairy water buffalo milk subject Drug Resistance, Multiple, Bacterial subject Food Microbiology subject Food safety subject Genomics subject High somatic cell count subject Humans subject Journal Article subject Klebsiella Infections subject Klebsiella pneumoniae subject

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