OBJECTIVE: Our study aimed to conduct genomic characterization of Salmonella strains carrying the bla _NDM-1 gene in the intestinal tract of healthy individuals. The objectives were to underscore the importance of genomic surveillance for drug resistance in both commensal and pathogenic bacteria among healthy populations, and to establish protocols for regulating drug resistance plasmids based on the completion of a comprehensive map of drug resistance plasmid genomes. METHODS: We performed antimicrobial susceptibility testing and employed second- and third-generation sequencing techniques to analyze Salmonella strains harboring the bla _NDM-1 gene, to surveil drug-resistant bacteria in the intestines of healthy subjects. Sequence comparison was conducted using both core- and pan-genome approaches. Concurrently, conjugation experiments were carried out to assess the efficiency of plasmid transfer. RESULTS: We isolated a carbapenem-resistant Salmonella enterica serovar Typhimurium strain from a healthy food worker in China. This strain harbored an IncHI2/IncHI2A plasmid carrying bla _NDM-1 along with multiple antibiotic resistance genes (ARGs). Our findings highlight the potential for asymptomatic carriers to facilitate the transmission of ARGs. Pan-genomic analysis revealed that bla _NDM-1-positive plasmids could traverse bacterial species barriers, facilitating cross-host transmission. CONCLUSION This study marks the first detection of bla _NDM-1 in Salmonella strains isolated from healthy individuals. We underscore the risk associated with the transmission of conjugative hybrid plasmids carrying bla _NDM-1, which have the potential to be harbored and transmitted among healthy individuals. Enhanced surveillance of drug-resistant pathogens and plasmids in the intestinal microbiota of healthy individuals could provide insights into the risk of ARG transmission and pathways for population-wide dissemination via ARG transfer factors.
beta-Lactamases/genetics* ; Plasmids/genetics* ; Humans ; Anti-Bacterial Agents/pharmacology* ; China ; Microbial Sensitivity Tests ; Salmonella typhimurium/isolation & purification* ; Salmonella/isolation & purification* ; Salmonella Infections/microbiology*

Objective X-linked adrenoleukodystrophy (X-ALD) is a genetically determined disorder that is characterized by demyelination of central nervous system,and impaired adrenal cortex and abnormal accumulation of very long chain fatty acids in body fluid and tissue.The clinical manifestation,biochemical change,and magnetic resonance imaging were analyzed.Methods Clinical data of 11 cases with X-ALD were summarized and analyzed,including symptoms,signs,and inspection result.Relevant literature was reviewed.Results All cases were males,whose average onset age was (7.2 ± 4.7) year-old.It was (2.4 ± 1.9) years that the mean interval appears from onset to diagnosis.Six cases were with onset of adrenal insufficiency (AI),remaining 5 onset neural symptoms,where plasma very-long-chain fatty acids (VLCFA) was tested in 6 patients,all with abnormally high levels and brain magnetic resonance imaging(MRI) showed demyelination of cerebral white matter in 9 ones.Conclusions ALD is a X-linked genetically determined disorder that mainly affects the nervous system and adrenal gland.Plasma VLCFA test,ALD gene test,and cerebral MRI are reliable diagnostic methods.Early diagnosis and appropriate therapy would improve survival and neurological outcomes.