Introduction
Cirrhosis and other chronic liver diseases (collectively referred to herein as cirrhosis) are one of the major causes of morbidity and mortality worldwide1. Spontaneous bacterial peritonitis (SBP) is a common and potentially fatal complication of liver cirrhosis2.
Figure 1:Spontaneous bacterial peritonitis infection
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SBP is most often caused by infection in fluid that collects in the peritoneal cavity (ascites)3. The fluid buildup often occurs with advanced liver or kidney disease. The mortality rate of patients with SBP complications is as high as 25-30%, and the early clinical diagnosis, pathological diagnosis and anti-infective treatment of SBP have always been a difficult problem.
Current status of SBP diagnosis
Liver ascites and liver cirrhosis are closely related, and the severity of the disease can be judged by ascites. Detection of pathogenic bacteria in ascites is the current international "gold standard" for the diagnosis of SBP, but the traditional detection methods have many drawbacks.
Figure 2: The testing process and treatment of SBP4
(Picture comes from JAMA. If it is an infringement of your copyrights, please contact us.）
First of all, it is difficult to obtain test samples, and it is necessary to perform diagnostic puncture on the patient to sample, which brings great pain to the patient. Second, if the number of bacteria in the sample is low, it can lead to problems such as bacteria that cannot be cultured or that have low sensitivity. Finally, the longer time required for bacterial culture is likely to cause patients to miss the best opportunity for antimicrobial therapy and increase mortality.
The progress of molecular diagnosis in SBP
The detection and sequencing of bacterial DNA is now increasingly used in the diagnosis of infectious diseases. Molecular techniques can detect trace amounts of bacterial DNA and improve the speed and accuracy of bacterial identification compared to microbial cultures5.
Since 2014, Krohn et al. have proposed the use of fluorescent PCR (qPCR) to detect bacterial counts in ascites6. Initially, the researchers thought that a qualitative test of bacterial DNA could determine whether a patient had SBP.
However, subsequent experiments found that bacterial DNA characterization is insufficient to predict the development of SBP7.Because, in decompensated cirrhosis, pathological bacterial translocation (BT) from the gastrointestinal lumen to the mesenteric lymph nodes and into the systemic circulation is a common phenomenon. Although patients with cirrhosis were not infected with SBP, bacterial DNA fragments remained in the patients and were misdiagnosed as patients with SBP.
In 2015, Fagan et al. found that the quantitative detection of bacterial DNA may be more helpful for the diagnosis of SBP than the qualitative detection of bacterial DNA8.
For the accuracy of diagnosis, the researchers tried to combine the qualitative and quantitative detection of specific bacterial species for the diagnosis of SBP. For example, cirrhotic patients with α-proteobacteria and γ-proteobacteria in their ascites are more likely to have SBP9.
Future prospects
The diagnosis of SBP has always been a difficult problem due to the complex and diverse clinical conditions of patients with cirrhotic ascites and the difficulty of sampling. So far, the diagnosis of SBP is still based on traditional methods, and there is no more mature SBP molecular diagnosis product on the market. However, with the advancement of molecular technology, the qualitative and quantitative determination of bacteria and the use of sequencing technology to determine the type of bacteria also make molecular diagnostic technology have great potential in the clinical detection of SBP.
Vazyme Solutions
As a supplier of professional products and solutions in life sciences, in vitro diagnostics and life medicine, Vazyme will give full play to the advantages in raw materials. In the field of diagnostic products for spontaneous bacterial peritonitis (SBP), we provide the extraction and amplification products you need for product development.
Nucleic Acid Isolation (click on the Cat.No. to see the detail of each product)
| Cat. No. | Product name | Product advantages |
| DC502 | FastPure Microbiome DNA Isolation Kit |
Ultra-fast extraction |
| DC112 | FastPure Blood/Cell/Tissue/Bacteria DNA Isolation Mini Kit |
Good DNA integrity |
Nucleic Acid Amplification(click on the Cat.No. to see the detail of each product)
| Cat. No. | Product name | Product advantages |
| P401-MD1 | AceTaq DNA Polymerase |
Hot-start enzymes |
| P122-MD2 | FastPure Blood/Cell/Tissue/Bacteria DNA Isolation Mini Kit |
Hot-start enzymes |
| PN102 | Taq Pro HS DNA Polymerase for ddPCR |
Upgraded hot-start enzymes |
| P132 | Taq HS DNA Polymerase |
Antibody modification |
| P051 | Heat-labile UDG | Rapid inactivation at 55°C for 10 minutes |
| P703 | Bst II Pro DNA Polymerase Large Fragment |
Room temperature establishment system |
| Q513 | AceQ Universal U+ Probe Master Mix V2 |
Excellent amplification sensitivity |
| QN213 | Taq Pro U+ Multiple Probe qPCR Mix |
Excellent amplification performance |
| Q113 | AceQ U+ Probe Master Mix |
Probe assay kit |
Reference
1. GBD 2017 Cirrhosis Collaborators (2020). The global, regional, and national burden of cirrhosis by cause in 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017. The lancet. Gastroenterology & hepatology, 5(3), 245–266. https://doi.org/10.1016/S2468-1253(19)30349-8
2. Tay, P., Xiao, J., Tan, D., Ng, C., Lye, Y. N., Lim, W. H., Teo, V., Heng, R., Yeow, M., Lum, L., Tan, E., Kew, G. S., Lee, G. H., & Muthiah, M. D. (2021). An Epidemiological Meta-Analysis on the Worldwide Prevalence, Resistance, and Outcomes of Spontaneous Bacterial Peritonitis in Cirrhosis. Frontiers in medicine, 8, 693652. https://doi.org/10.3389/fmed.2021.693652
3. Encyclopedia, M., & bacterial, P. (2022). Peritonitis - spontaneous bacterial: MedlinePlus Medical Encyclopedia. Retrieved 26 July 2022, from https://medlineplus.gov/ency/article/000648.htm
4. Zhang, G., & Faust, A. J. (2021). Spontaneous Bacterial Peritonitis. JAMA, 325(11), 1118-1118.
5. Woo, P. C., Lau, S. K., Teng, J. L., Tse, H., & Yuen, K. Y. (2008). Then and now: use of 16S rDNA gene sequencing for bacterial identification and discovery of novel bacteria in clinical microbiology laboratories. Clinical Microbiology and Infection, 14(10), 908-934.
6. Krohn, S. , S Böhm, Engelmann, C. , Hartmann, J. , Brodzinski, A. , & Chatzinotas, A. , et al. (2014). Application of qualitative and quantitative real-time pcr, direct sequencing, and terminal restriction fragment length polymorphism analysis for detection and identification of polymicrobial 16s rrna genes in ascites. Journal of Clinical Microbiology, 52(5), 1754.
7. Bruns, T., Reuken, P. A., Stengel, S., Gerber, L., Appenrodt, B., Schade, J. H., ... & Stallmach, A. (2016). The prognostic significance of bacterial DNA in patients with decompensated cirrhosis and suspected infection. Liver International, 36(8), 1133-1142.
8. Fagan, K. J. , Rogers, G. B. , Melino, M. , Arthur, D. M. , & Irvine, K. M. . (2015). Ascites bacterial burden and immune cell profile are associated with poor clinical outcomes in the absence of overt infection. PLoS ONE, 10(3), e0120642.
9. Chen, Y., Guo, J., Shi, D., Fang, D., Chen, C., & Li, L. (2018). Ascitic bacterial composition is associated with clinical outcomes in cirrhotic patients with culture-negative and non-neutrocytic ascites. Frontiers in Cellular and Infection Microbiology, 8, 420.
