Rapid and visual detection of specific bacteria for saliva and vaginal fluid identification with the lateral flow dipstick strategy.

Identification of body fluids is critical for crime scene reconstruction, and a source of investigation source of investigative leads. In recent years, microbial DNA analysis using sequencing and quantitative real-time polymerase chain reaction have been used to identify body fluids. However, these techniques are time-consuming, expensive, and require complex workflows. In this study, a new method for simultaneous detection of Streptococcus salivarius and Lactobacillus crispatus using polymerase chain reaction (PCR) in combination with a lateral flow dipstick (LFD) was developed to identify saliva and vaginal fluid in forensic samples. LFD results can be observed with the naked eye within 3 min with a sensitivity of 0.001 ng/µL DNA. The PCR-LFD assay was successfully used to detect S. salivarius and L. crispatus in saliva and vaginal fluid respectively, and showed negative results in blood, semen, nasal fluid, and skin. Moreover, saliva and vaginal fluid were detectable even at an extremely high mixing ratio of sample DNA (1:999). Saliva and vaginal fluid were identified in various mock forensic samples. These results indicate that saliva and vaginal fluid can be effectively detected by identifying S. salivarius and L. crispatus, respectively. Furthermore, we have shown that DNA samples used to identify saliva and vaginal fluid can also provide a complete short tandem repeat (STR) profile when used as source material for forensic STR profiling. In summary, our results suggest that PCR-LFD is a promising assay for rapid, simple, reliable, and efficient identification of body fluids.

Antifouling Electrochemical Biosensor Based on the Designed Functional Peptide and the Electrodeposited Conducting Polymer for CTC Analysis in Human Blood.

Circulating tumor cells (CTCs) are considered reliable cancer biomarkers for the liquid biopsy of many types of tumors. The direct detection of CTCs in human blood with normal biosensors, however, remains challenging because of severe biofouling in blood that contains various proteins and a large number of cells. Herein, we report the construction of an antifouling electrochemical biosensor capable of assaying CTCs directly in blood, based on a designed multifunctional peptide and the electrodeposited conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT). The designed peptide possesses antifouling capability in complex biological media and specific recognition ability to capture breast cancer cells MCF-7. Meanwhile, electrodeposited PEDOT can promote electron transfer at the sensing interface, improve the signal-to-noise ratio for the detection, and thus enhance the sensitivity of the biosensor. The integration of the multifunctional peptide and conducting polymer PEDOT ensures that the developed biosensor is able to perform directly in blood samples without purification or separation. The antifouling electrochemical biosensor for the detection of MCF-7 cells exhibits a wide linear range over 4 orders, with a limit of detection (LOD) of 17 cells mL-1. More interestingly, even when performing in 25% human blood, the biosensor still retains a linear response with an LOD of 22 cells mL-1, without suffering significantly from biofouling in real blood. This work provides a promising strategy for the direct analysis of CTCs in human blood without a complicated pretreatment, and it may find practical application in the liquid biopsy of cancers.

Rational Design of Ag/ZnO Hybrid Nanoparticles on Sericin/Agarose Composite Film for Enhanced Antimicrobial Applications.

Silver-based hybrid nanomaterials are receiving increasing attention as potential alternatives for traditional antimicrobial agents. Here, we proposed a simple and eco-friendly strategy to efficiently assemble zinc oxide nanoparticles (ZnO) and silver nanoparticles (AgNPs) on sericin-agarose composite film to impart superior antimicrobial activity. Based on a layer-by-layer self-assembly strategy, AgNPs and ZnO were immobilized on sericin-agarose films using the adhesion property of polydopamine. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray powder diffraction spectroscopy were used to show the morphology of AgNPs and ZnO on the surface of the composite film and analyze the composition and structure of AgNPs and ZnO, respectively. Water contact angle, swelling ratio, and mechanical property were determined to characterize the hydrophilicity, water absorption ability, and mechanical properties of the composite films. In addition, the antibacterial activity of the composite film was evaluated against Gram-positive and Gram-negative bacteria. The results showed that the composite film not only has desirable hydrophilicity, high water absorption ability, and favorable mechanical properties but also exhibits excellent antimicrobial activity against both Gram-positive and Gram-negative bacteria. It has shown great potential as a novel antimicrobial biomaterial for wound dressing, artificial skin, and tissue engineering.

Effects of routine procedures on salivary cortisol in mechanically ventilated neonates.

Even though the stress secondary to invasive procedures has been investigated, less attention has been paid to the stimulation or pain caused by routine procedures on neonates. The changes in salivary cortisol concentration in mechanically ventilated NICU patients during routine procedures were monitored to provide reference and guidance for pain management. 80 mechanically ventilated neonates in the hospital from Sep 2021 to Mar 2022 were selected. The salivary cortisol levels of the neonates were monitored during nursing procedures and were categorized by their risk levels to the following groups: high-risk (endotracheal suctioning and arterial blood sampling), moderate-risk (gastric tube insertion, venipuncture), and low-risk (bedside bathing and diaper changes). The changes in heart rate were also recorded and compared. The concentration of cortisol in the saliva of the neonates was 1.5 ± 0.8 nmol/L during the sleeping state, 6.2 ± 1.3 nmol/L during endotracheal suctioning, 6.4 ± 1.4 nmol/L during arterial blood sampling, 6.1 ± 1.2 nmol/L during venipuncture, 4.4 ± 1.1 nmol/L during gastric tube insertion, 3.5 ± 0.8 nmol/L during bedside bathing, and 3.3 ± 0.9 nmol/L during a diaper change. The results revealed a statistically significant effect between routine procedures on salivary cortisol levels. Compared with the neonates in the control sleep state, there was a significant (P < 0.05) change in salivary cortisol concentration of infants undergoing high and moderate-risk nursing procedures. There was a small but significant (P < 0.05) change in salivary cortisol levels in infants who underwent low-risk procedures compared to infants in the control sleep state. Further, the fluctuation of salivary cortisol levels in routine procedures was more frequent compared with routine handling at night. The fluctuations of salivary cortisol concentration in high-risk procedures were larger than that of infants who underwent low-risk procedures, with the difference being statistically significant (P < 0.05). It was also determined that the top four influencing factors on the infants' heart rate were arterial blood sampling venipuncture, intubation, endotracheal suctioning, and gastric tube insertion (P < 0.05). Monitoring the saliva cortisol concentration index and heart rates can reflect the impact of different routine procedures on newborns and can be used to manage neonatal pain in the future.

The Effects of Drug Addiction and Detoxification on the Human Oral Microbiota.

Drug addiction can powerfully and chronically damage human health. Detoxification contributes to health recovery of the body. It is well established that drug abuse is associated with poor oral health in terms of dental caries and periodontal diseases. We supposed that drug addiction and detoxification might have significant effects on the oral microbiota. To test the hypothesis, we assessed the effects of drug (heroin and methylamphetamine) addiction/detoxification on the oral microbiota based on 16S rRNA gene sequencing by an observational investigation, including 495 saliva samples from participants. The oral microbial compositions differed between non-users, current and former drug users. Lower alpha diversities were observed in current drug users, with no significant differences between non-users and former drug users. Heroin and METH addiction can cause consistent variations in several specific phyla, such as the enrichment of Acidobacteria and depletion of Proteobacteria and Tenericutes. Current drug users had significantly lower relative abundances of Neisseria subflava and Haemophilus parainfluenzae compared to non-users and former drug users. The result of random forest prediction model suggested that the oral microbiota has a powerful classification potential for distinguishing current drug users from non-users and former drug users. A cooccurrence network analysis showed that current drug users had more complex oral microbial networks and lower functional modularity. Overall, our study suggested that drug addiction may damage the balance of the oral microbiota. These results may have benefits for further understanding the effects of addiction-related oral microbiota on the health of drug users and promoting the microbiota to serve as a potential tool for accurate forensic identification. IMPORTANCE Drug addiction has serious negative consequences for human health and public security. The evidence indicates that drug abuse can cause poor oral health. In the current study, we observed that drug addiction caused oral microbial dysbiosis. Detoxication have positive effects on the recovery of oral microbial community structures to some extent. Understanding the effects of drug addiction and detoxification on oral microbial communities will promote a more rational approach for recovering the oral function and health of drug users. Furthermore, specific microbial species might be considered biomarkers that could provide information regarding drug abuse status for saliva left at crime scenes. To the best of our knowledge, this is the first report on the role of the oral microbiota in drug addiction and detoxification. Our findings give new clues to understand the association between drug addiction and oral health.