Infectious diseases caused by pathogenic bacteria pose a critical threat to global public health security. However, existing research predominantly focuses on elucidating the acute virulence mechanisms of typical culturable (Wild-Type, WT) pathogenic bacteria, whereas studies on the host infection modes, virulence levels, and pathogenic mechanisms of viable but non-culturable (VBNC) state pathogens are notably lacking. Therefore, this study established a Staphylococcus aureus (S. aureus) (including VBNC state) -Caenorhabditis elegans (C. elegans) infection system. Following infection, S. aureus within exposed nematodes was released via lysis techniques to investigate bacterial state transitions, virulence protein secretion, and virulence gene expression patterns, aiming to elucidate infection mechanisms under distinct bacterial states. Findings of this research revealed that wild-type S. aureus exhibited accelerated proliferation and intestinal colonization in nematodes, accompanied by substantial virulence protein release, triggering acute infection. In contrast, VBNC-state S. aureus displayed significantly reduced reproductive and colonization capacities. Notably, VBNC-state S. aureus underwent resuscitation within the nematode host, achieving a resuscitation rate of 90.4%, representing a sixfold increase compared with natural resuscitation in vitro. Furthermore, wild-type S. aureus subverted host immune defenses through global upregulation of virulence gene expression. Conversely, VBNC-state S. aureus exhibited a distinct pathogenic pattern: delayed virulence gene expression, prioritized activation of biofilm formation-related genes to establish resuscitation conditions, followed by gradual restoration of virulence gene expression through stress response systems, ultimately re-establishing pathogenicity and inducing chronic infection. This unique virulence resuscitation mechanism facilitates VBNC-state S. aureus in maintaining long-term colonization under host immune pressure. Consequently, long-term monitoring of both typical pathogenic bacteria and their VBNC-state counterparts in environmental systems is imperative to prevent potential health risks.

Currently, there is sufficient evidence of carcinogenicity of parent Polycyclic Aromatic Hydrocarbons (PAHs), and their methylated (Methyl PAHs, MPAHs), heterocyclic (Heterocyclic PAHs, HPAHs), halogenated (Halogenated PAHs, XPAHs) and oxygenated (Oxygenated PAHs, OPAHs) derivatives are also proved to be more toxic than their parent compounds. However, most of the studies focus on the distribution characteristics of them in various environmental media, and few studies have measured their levels in human body fluids, especially in serum. Most of the pretreatment methods for extracting PAHs and their derivatives from serum focus only on one or two types of PAH derivatives. To fill this gap, this study optimized the pretreatment methods by comparing the recoveries of different liquid-liquid extraction of extracts, solid-phase extraction columns and eluent volumes to detect the total of 68 PAHs and their derivatives (five types of substances including PAHs, MPAHs, HPAHs, XPAHs, and OPAHs). Results showed that the extract was carried out with 3 mL of acetonitrile + 1 mL of ethyl acetate : dichloromethane : n-hexane (20% : 40% : 40%, volume fraction), and cleaned up by elution with a Florisil solid-phase extraction column and 10 mL of a 1 : 1 mixture of dichloromethane and ethyl acetate was combined with GC-MS/MS analysis to establish an analytical method for 68 PAHs and their derivatives in serum with high sensitivity and accuracy. The developed method exhibited a limit of detection ranging from 0.007 to 1.3 ng/mL. The method recovery was between 60% and 140%, with accuracy ranging from 50% to 150%. This method was successfully applied to determine 29 PAHs and their derivatives in the serum of workers in a petrochemical industry. Ultimately, 11 PAHs, 7 MPAHs, 5 HPAHs, 3 XPAHs, and 3 OPAHs were quantified. Among the measured compounds, concentration of 2-methylnaphthalene was the highest (50 ng/mL), followed by 5-bromoanthracene (36 ng/mL). The method is well-suited for analyzing PAHs and their derivatives in human serum and can be effectively utilized to investigate the health impacts of them on humans.