The Sensitivity and Specificity of Loop-Mediated Isothermal Amplification and PCR Methods in Detection of Foodborne Microorganisms: A Systematic Review and Meta-Analysis.

BACKGROUND: The loop-mediated isothermal amplification (LAMP) method is frequently used for identifying many microorganisms. The present review aimed to evaluate the sensitivity and specificity of LAMP method for detection of food-borne bacteria and to compare these features with those of polymerase chain reaction (PCR), as an alternative molecular diagnostic procedure, and with cultivation method, as the gold standard method. METHODS: The literature was searched in electronic databases (PubMed, Scopus, Web of Science, and EMBASE) for recruiting publications within Jan 2000 to Jul 2021. We used the combinations of keywords including foodborne disease, LAMP, PCR, Loop-mediated isothermal amplification, and polymerase chain reaction. Meta-analysis was used to adjust the correlation and heterogeneity between the studies. The efficiency of the methods was presented by negative likelihood ratio, positive likelihood ratio, sensitivity, specificity, and odds ratio using forest plots. A P-value less than 0.05 was considered as statistical significance cut off. The confidence intervals were presented at the 95% interval. RESULTS: Overall, 23 relevant studies were analyzed. The sensitivities of LAMP and PCR methods were estimated to be 96.6% (95% CI: 95.0-97.7) and 95.6% (95%CI: 91.5-97.8), respectively. The specificities of LAMP and PCR were also estimated to be 97.6% (95%CI: 92.6-99.3) and 98.7% (95%CI: 96.5-99.5), respectively. CONCLUSION: The specificities of LAMP and PCR assays were determined by comparing their results with cultivation method as the gold standard. Overall, the specificity of both PCR and LAMP methods was low for detection of fastidious bacteria. Nevertheless, LAMP and PCR methods have acceptable specificities and sensitivities, and their application in clinical practice necessitates more studies.

Psp140: an immunodominant antigen in the supernatant of Streptococcus pneumoniae culture.

BACKGROUND AND OBJECTIVES: Streptococcus pneumoniae causes many lethal infections. Due to its reduced sensitivity to commonly used antibiotics, development of new strategies against pneumococcal infections seems to be necessary. We aimed to investigate immunodominant antigens in S. pneumoniae culture supernatant in order to develop novel targets for pneumococcal vaccines. MATERIALS AND METHODS: In this study S. pneumoniae ATCC49619 was sub-cultured into BHI broth from overnight culture at 37°C for 4 h. The supernatant proteins were precipitated using acetone precipitation method. A rabbit was intramuscularly immunized with alum adjuvant and 100 µg pneumococcal supernatant proteins, 6 times at 14 days' intervals to produce hyperimmune serum. ELISA assay was performed to determine the antibody level response to pneumococcal secretory proteins. Then dot blot applied for rapid evaluation of hyperimmune serum reactivity to pneumococcus supernatant proteins. The western blot was also used to determine the interaction of supernatant proteins with immunogenic rabbit's hyperimmune-serum. RESULTS: According to the western blot analysis, the immunodominant protein had 140KDa molecular weight and designated as pneumococcal secretory protein140 (Psp140). CONCLUSION: The Psp140 protein in the supernatant of S. pneumoniae culture is an immunodominant protein and it is likely related to pneumococcal secretory protein or surface exposed protein which released into culture supernatant during bacterial growth.

Molecular docking of the pneumococcal main autolysin (LytA) and deoxycholate ligand.

In the Streptococcus pneumoniae, the N-acetylmuramoyl-l-alanine amidase known as LytA protein is a main autolysin and in the presence of sodium deoxycholate, it activates and breaks S. pneumoniae cell wall. In the present study, the interaction between the LytA protein and deoxycholate as ligand was investigated. The Lyt A protein was retrieved from PDB databank and energetically minimized by Molegro Virtual Docker. The binding sites of LytA protein were detected and molecular docking carried out using MolDock algorithm. Finally, the number of hydrogen and electrostatic bonds were obtained for each predicted pose. A total of 5 binding sites predicted on LytA protein. The number of 5 predicted poses for each binding site also detected and molecular docking showed that all the poses have interactions (by H bonds) with deoxycholate. The interaction of the LytA protein with the deoxycholate ligand reveal five binding sites, which are involved in deoxycholate substrate recognition.

Radical cystectomy for management of inflammatory myofibroblastic tumor of the urinary bladder: A rare case report.

Inflammatory myofibroblastic tumor (IMT) of the bladder also known as pseudosarcomatous myofibroblastic proliferation is a rare lesion in the genitourinary tract was first described in 1980 by Roth. We herein report a case of urinary bladder IMT in a 42-year-old female patient presented with gross hematuria. The hematuria was difficult to control and radical treatment has been done. Monitoring for recurrence is strongly advisable.