# An Overview of the Public Health Challenges in Diagnosing and Controlling Human Foodborne Pathogens
## 4 Diagnostic Approaches of Foodborne Pathogens
### Methods Based on Nucleic Acids
#### 4.2.2 Isothermal Amplification  
Loop-Mediated Isothermal Amplification (LAMP)  
Molecular amplification of nucleic acids is a technique that has been developed by [PERSON] et al. [143], who developed the LAMP method. The LAMP technique is very specific, since it uses four or six different primers and binds one from each pair to six or eight (sometimes) specific locations on the target gene itself. All of the reactions can be conducted at isothermal conditions between 60 and 65 \({}^{\circ}\)C, which is the ideal temperature range (Figure 2). A post-amplification electrophoresis is not needed for the detection of PCR products since the process can be carried out visually without the use of any device [144,145]. First of all, the detection of _StxA2_ by LAMP is a first in the area of foodborne pathogen detection, having been performed in _Escherichia coli_ O157:H7 strains [146]. It can possibly be argued that the characteristics of LAMP are less hazardous to health than those obtained by in situ PCR due to the mild permeable nature and low isothermal temperature used. According to the results, this approach is more successful in producing images that feature more contrast than the in situ PCR method [147]. The LAMP method was used by [PERSON] et al. [148] for the purpose of determining the frequency of foodborne pathogens associated with dairy products. In less than 30 min, a single copy of a gene can be identifiedusing LAMP, thus making it extremely quick and sensitive. The LAMP technique has been designed and evaluated by [PERSON] et al. [149] as a method for identifying foodborne _Salmonella_ strains rapidly. An optimal reaction temperature of 65 \({}^{\circ}\)C for 45 min was found to be optimal when detecting 1 pg of DNA per tube and 100 CFU per reaction. A total of 214 _Salmonella_ strains isolated from food sources were subjected to rapid and simple LAMP screenings. For both LAMP and PCR, the accuracy rates were 97.7% (209/214) and 91.6% (196/214), respectively, with 100% specificity. Based on the results of 39 reference strains that were tested simultaneously using the LAMP assay, high specificity was achieved and no false positives occurred. As a result, it can be concluded that the LAMP test is a convenient and effective method of identifying _Salmonella_ strains in a timely manner. This modified LAMP approach has advantages in terms of simplicity and time consumption compared to previously published LAMP analyses used to identify Salmonella strains. A total of 60 min was spent on the entire detection process, including DNA extraction, LAMP reactivity, reporting the results and interpreting the data. In all probability, LAMP assays will be widely used for the identification of microbiological _Salmonella_ species based on their speed, simplicity and affordability. As far as identifying particular infections is concerned, LAMP is one of the easiest methods. An amplification reaction can be completed at a steady temperature, as long as the temperature remains constant. This technique has been shown to be far more sensitive than traditional PCR because of the advantage in sensitivity that LAMP offers. There is no doubt that one can complete the test in 30-60 min [150; 151]. Unless there are measures taken to prevent cross-contamination, an amplified sequence has a maximum length of 300 bp; furthermore, non-specific pairing between loop primers will yield false positive results and cross-contamination can occur unless precautions are taken to prevent it [124]. There are also a number of complications and costs involved in the creation of primers. Figure 2: Workflow of LAMP for detection of foodborne pathogens. Nucleic Acid Sequence-Based Amplification (NASBA)  
In contrast to conventional PCR, which is used to detect DNA, NASBA uses isothermal amplification of RNA from the target organism, making it more sensitive than conventional PCR [152]. In order to perform thermal cycling, there is no need for any additional equipment.