Ji Zeng,Rong Fu,Jiahao Ji,Tong Xing,Dongping Hou,Zefeng Li,Zepeng Zhao,Shaoting Li,Hongmei Zhang
Salmonella enterica is a common foodborne pathogen that poses significant safety risks across the world. And benzalkonium bromide (BK) is widely used as a disinfectant to sterilize the food processing equipment. It has been reported that sub-lethal concentration of disinfectants induced not only the homologous resistance but also cross-resistances. This work analyzed the induced resistances of Salmonella Enteritidis by short-term adaptation (STA) and long-term adaptation (LTA) to BK. We have demonstrated that inefficient sterilization exposes Salmonella Enteritidis to sub-lethal concentrations of BK, and adapts bacteria to a higher minimum inhibitory concentration and minimum bactericidal concentration. In addition, STA, but not LTA, to BK induced heterogeneous resistance to sodium hypochlorite, and cross-resistance to freezing, desiccation, and heating, which may be caused by the membrane composition change of Salmonella Enteritidis. This work could be useful to the optimization of cleaning protocol.
Lan Sugui,Li Zhirong,Su Aiqiu,Peng Yanhong,Liao Yanke,Liu Xuemei,Tan Qiang
The purpose of this study was focused on the mechanisms of the cross-resistance to tetracycline (TET), piperacillin Sodium (PIP), and gentamicin (GEN) in Staphylococcus aureus (SA) mediated by Rhizoma Coptidis extracts (RCE). The selected strains were exposed continuously to RCE at the sublethal concentrations for 12 days, respectively. The susceptibility change of the drug-exposed strains was determined by analysis of the minimum inhibitory concentration. The 16S rDNA sequencing method was used to identify the RCE-exposed strain. Then the expression of resistant genes in the selected isolates was analyzed by transcriptome sequencing. The results indicated that RCE could trigger the preferential cross-resistance to TET, PIP, and GEN in SA. The correlative resistant genes to the three kinds of antibiotics were upregulated in the RCE-exposed strain, and the mRNA levels of the resistant genes determined by RT-qPCR were consistent with those from the transcriptome analysis. It was suggested from these results that the antibacterial Traditional Chinese Medicines might be a significant factor of causing the bacterial antibiotic-resistance.
Li Cui,Ying-Jiao Zhang,Wei E. Huang,Bi-Feng Zhang,Francis L. Martin,Jun-Yi Li,Kai-Song Zhang,Yong-Guan Zhu
Bacterial antibiotic resistance poses a threat to global public health. Restricted usage of antibiotics does not necessarily prevent its continued emergence. Rapid and sensitive screening of triggers, in addition to antibiotic, and exploring the underlying mechanism are still major challenges. Herein, by developing a homogeneous vacuum filtration-based bacterial sample fabrication enabling high surface-enhanced Raman scattering (SERS) reproducibility across multiple bacterial samples and negating interfering spectral variations from inhomogeneous sample geometry and SERS enhancement, SERS was employed to study heavy metal arsenic [As(V)]-mediated antibiotic resistance in a robust, sensitive, and rapid fashion. Independent and robust spectral changes representing phenotypic bacterial responses, combined with multivariate analysis, clearly identified that As(V) enhanced antibiotic resistance to tetracycline (Tet). Similar spectral alteration profile to As(V) and Tet indicated that cross-resistance, whereby As(V)-induced bacterial resistance simultaneously blocked Tet action, could account for the enhanced resistance. The sensitive, robust, and rich phenotypic profile provided by SERS, combined with additional advantages in imposing no need to cultivate bacteria and single-cell sensitivity, can be further exploited to evaluate resistance-intervening factors in real microbiota.
危险品化学品经营许可证（带存储）