Application of mNGS in the Etiological Diagnosis of Thoracic and Abdominal Infection in Patients With End-Stage Liver Disease

BackgroundDespite the obvious advantages of metagenomic next-generation sequencing (mNGS) in etiological diagnosis of various infectious diseases, there are few reports on etiological diagnosis of suspected thoracic and abdominal infections in patients with end-stage liver disease (ESLD).MethodsSeventy-three ESLD patients were enrolled from January 2019 to May 2021 due to suspected complicated thoracic and abdominal infections with poor response to empirical anti-infective treatment. Pleural effusion and ascites samples of these patients were collected for mNGS detection and conventional pathogen culture. The application value of mNGS in etiological diagnosis of thoracic and abdominal infections in ESLD patients was finally evaluated.ResultsA total of 96 pathogens were detected using mNGS method, including 47 bacteria, 32 viruses, 14 fungi, 2 Mycobacterium tuberculosis, and 1 parasite. The positive rate of mNGS reached 42.5%, which was significantly higher than that of conventional culture method (21.9%) (p = 0.008). Considering neutrophil counts, the overall positive rate of bacteria detection of both methods in Polymorphonuclear Neutrophils (PMN) ≥250/mm3 group was 64.3% and in PMN <250/mm3 group was 23.7%. Compared with the final clinical diagnosis, the agreement rate of mNGS in patients with positive bacteria detection and with suspected positive bacteria detection was 78.6% (11/14) and 44.4% (8/18), respectively. In addition, the agreement rate of mNGS was 66.7% (4/6, respectively) in patients with positive and suspected fungal detection. Interestingly, of the 11 patients with fungal detection, 5 had alcoholic liver disease, accounting for 45.5% of all patients with alcoholic liver disease. We also detected 32 strains of viruses using mNGS, mainly cytomegalovirus (62.5%).ConclusionsThe mNGS method is a useful supplement to conventional culture methods, which performs a higher positive rate, higher sensitivity, and broader pathogen spectrum, especially for rare pathogens and those difficult to culture. For ESLD patients, mNGS has great prospects in early etiological diagnosis of thoracic and abdominal infections. In addition, the cutoff values for the diagnosis of bacterial infection (PMN ≥250/mm3) in the thoracic and abdominal cavities may need to be redefined.

Detection of Salmonella sp. on Bulk Meatballs and Packaged Meatballs at Sepanjang Market, Sidoarjo

Background: Bacterial contamination in food can cause congenital diseases in the form of infections. Meatballs are one of the foods that are in demand by the public and foods that can be contaminated with salmonella bacteria. Detection of Salmonella sp bacteria can determine the quality of bulk meatballs and packaged meatballs. Salmonella sp bacteria should not contaminate the meatballs according to the quality requirements of the BSNI (Badan Standarisasi Nasional Indonesia). Purpose: To determine the contamination of Salmonella sp bacteria in bulk meatballs and packaged meatballs sold at Sepanjang market, Taman District, Sidoarjo Regency. Methods: The Salmonella sp. test on meatballs was carried out in four stages, pre-enrichment using Buffered Pepthone Water solution, enrichment using Tetrathionate Brothbase solution, isolation using Salmonella Shigella Agar media, and biochemical testing using Triple Sugar Iron Agar media. The samples used were 10 samples each. Result: The test proved that 20% of the samples were positively contaminated with Salmonella sp. both on bulk meatballs and on packaged meatballs. Conclusion: Food hygiene and sanitation must be applied properly and correctly in every process because food products circulating in public, especially meatball products, can avoid microbial contamination and be safe for consumption.