One-step sensitive detection of Salmonella typhimurium by coupling magnetic capture and fluorescence identification with functional nanospheres.

Sensitive, rapid, and reliable detection of bacteria has always been pursued due to the great threat of the bacteria to human health. In this study, a convenient one-step strategy for detecting Salmonella typhimurium was developed. Immunomagnetic nanospheres (IMNS) and immunofluorescent nanospheres (IFNS) were used to specifically capture and recognize S. typhimurium simultaneously. After magnetic separation, the sandwich immune complexes (IMNS-bacteria-IFNS) were detected under a fluorescence microscope with a detection limit as low as ca. 10 CFU/mL. When they were detected by fluorescence spectrometer, a linear range was exhibited at the concentration from 10(5) to 10(7) CFU/mL with R(2) = 0.9994. Compared with the two-step detection strategy, in which the bacteria were first captured with the IMNS and subsequently identified with the IFNS, this one-step strategy simplified the detection process and improved the sensitivity. Escherichia coli and Shigella flexneri both showed negative results with this method, indicating that this method had excellent selectivity and specificity. Moreover, this method had strong anti-interference ability, and it had been successfully used to detect S. typhimurium in synthetic samples (milk, fetal bovine serum, and urine), showing the potential application in practice.

Efficacy of Transnasal Endoscopic Fine-Needle Aspiration Biopsy in Diagnosing Submucosal Nasopharyngeal Carcinoma.

OBJECTIVES/HYPOTHESIS: The routine practices of examining submucosal lesions are not suitable for deep lesions. Therefore, we evaluated the efficacy of non-real-time image-guided transnasal endoscopic fine-needle aspiration biopsy (FNAB) in diagnosing nasopharyngeal carcinoma (NPC) with submucosal lesions. STUDY DESIGN: The effectiveness evaluation of diagnostic methods. METHODS: Fifty suspected NPC patients who failed in conventional biopsies were enrolled in this study. The efficacy, maneuverability, and safety of FNAB in diagnosing these intractable cases were evaluated. RESULTS: The definitive diagnostic results of these 50 patients were NPC (34/50, 68.0%), nasopharyngeal necrosis (1/50, 2.0%), nasopharyngeal mucositis (12/50, 24.0%), and other cancers (3/50, 6.0%), respectively. The results of the diagnostic efficacy of FNAB were sensitivity, 89.2%; specificity, 100.0%; positive predictive value, 100.0%; negative predictive value, 76.5%; and accuracy, 92.0%, respectively. The area under the receiver operating characteristic curves was 0.946 (95% confidence interval = 0.884-1.00, P < .001). No severe complications occurred after FNAB. CONCLUSIONS: FNAB can improve the diagnostic efficiency of NPC occurring in the submucosal space. It can be an additional option for routine nasopharyngeal biopsy and is worthy of clinical application. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:1798-1804, 2021.

Combined determination of Epstein-Barr virus-related antibodies and antigens for diagnosis of nasopharyngeal carcinoma.

BACKGROUND AND OBJECTIVE: With the development of molecular biology in recent years, many indexes for detecting Epstein-Barr virus (EBV) have been developed. This study was to evaluate the diagnostic value of combined determination of EBV-related antibodies and antigens, including VCA-IgA, EA-IgA, EBV-DNase antibody and EBV-DNA, in diagnosing nasopharyngeal carcinoma (NPC). METHODS: Serum and plasma samples from 160 untreated NPC patients and 76 healthy donors were collected. VCA-IgA and EA-IgA in the serum samples were detected by immunoenzyme staining method. Raji cells were stimulated by ortho-butanoic acid and croton oil to detect EBV-DNase antibody. The content of EBV-DNA in the plasma samples was detected by real-time fluorescence quantitative polymerase chain reaction (RQ-PCR). The diagnostic values of the indexes for NPC were evaluated. RESULTS: The sensitivity and specificity for diagnosing NPC were 90.0% and 89.5% for VCA-IgA, 75.0% and 94.7% for EA-IgA, 76.3% and 90.8% for EBV-DNase antibody, 68.8% and 88.2% for EBV-DNA, and 98.8% and 84.2% for combined determination. The positive rates of VCA-IgA and EA-IgA had no relationship with clinical stage of NPC (p > 0.05); nevertheless, the positive rates of EBV-DNase antibody and EBV-DNA were related with clinical stage (p < 0.05). CONCLUSIONS: The sensitivity of VCA-IgA and the specificity of EA-IgA are the highest while detecting solely. Combined determination could improve the diagnostic sensitivity and accuracy for NPC. EBV-DNase antibody and EBV-DNA could be helpful to evaluate the course of disease and classify the clinical stage of NPC.