A loop-mediated isothermal amplification (LAMP) assay for detection of Toxoplasma gondii infection in women with spontaneous abortion

The mechanism and improvements to the isothermal amplification of nucleic acids, at a glance

A comparative review of the most common isothermal methods is provided. In the last two decades, the challenge of using isothermal amplification systems as an alternate to the most extensive and long-standing nucleic acids-amplifying method-the polymerase chain reaction-has arisen. The main advantage of isothermal amplification is no requirement for expensive laboratory equipment for thermal cycling. Considerable efforts have been made to improve the current techniques of nucleic acid amplification and the development of new approaches based on the main drawbacks of each method. The most important and challenging goal was to achieve a low-cost, straightforward system that is rapid, specific, accurate, and sensitive.

Molecular evaluation of Toxocara species in stray cats using loop-mediated isothermal amplification (lamp) technique as a rapid, sensitive and simple screening assay

Toxocara species are parasitic nematodes of dogs and cats with a worldwide distribution. The adult worm lives in the intestine, and horizontal transmission of the infection occurs through eating paratenic host or embryonated eggs. This study aimed to estimate the molecular prevalence of Toxocara species in stray cats using the loop-mediated isothermal amplification (LAMP) technique. A total of 95 stool samples were randomly collected from stray cats in Khorramabad city in western Iran. Microscopic examination was performed after the separation and extraction of supernatants. The LAMP reaction was performed using the internal transcribed spacer 2 (ITS2) gene primers of Toxocara species and the appropriate master mix. The overall prevalence of Toxocara spp. in stray cats was 20% (19/95, CI 95%: 0.2 ± 0.08) by parasitological and molecular assessments. The microscopic examination of stool samples revealed that 19 samples were positive for Toxocara. The same 19 positive samples were also positive by the LAMP technique. Interestingly, based on the results of the LAMP assay, out of 95 studied samples, 18 (18.94%; CI 95%: 0.19 ± 0.08) specimens were Toxocara canis, while only 1 (1.05%; CI 95%: 0.005 ± 0.01) sample was diagnosed as Toxocara cati. The relatively high prevalence of Toxocara species in the studied cats shows the role of this species in spreading the parasite and the role of the cats in transmitting this zoonotic parasite. Preventive measures including the control of stray cat's population by castration and protection of public gardens where children play are recommended. The easy, highly sensitive and specific LAMP method is proposed for the differential detection of Toxocara species in animals and humans.

Accurate and rapid detection of Fasciola hepatica copro-DNA in sheep using loop-mediated isothermal amplification (LAMP) technique

Fascioliasis is a parasitic infection caused by Fasciola spp. in humans and animals. Despite significant advances in vaccination and new therapeutic agents, little attention has been paid to validate methods for the diagnosis of fascioliasis in animals. This study aimed to compare the loop‐mediated isothermal amplification (LAMP) technique with PCR assay for the diagnosis of F. hepatica in sheep. In this cross‐sectional study, 195 stool samples were collected from sheep for 3 months in Lorestan province, West of Iran. Specimens’ parasitological examination was performed by using the direct wet mount and formalin‐ether concentration method. After DNA extraction from the samples, molecular analysis was done using PCR and LAMP techniques based on the Fasciola ribosomal intergenic spacer (IGS) sequence. Of 195 specimens of sheep, 11 specimens were identified as F. hepatica‐positive infection by using microscopic, PCR and LAMP assays. Kappa agreement test results showed that there was a significant agreement between the results of microscopic examination diagnostic tests, PCR and LAMP (Kappa = 0.51–0.72 and p < .001). According to the results of chi‐square comparisons between parasite prevalence applying different techniques and variables of age, sex breed, and type of drinking water, there was no significant relationship (p ≥ .05). However, most of the infected sheep with Fasciola were 3‐ to 4‐year‐old females, of the Lori breed and consumed tap water. In many endemic areas, successful prevention and treatment of fascioliasis in animals depend on rapid and accurate diagnosis. Based on the results of the Kappa agreement, the significant agreement among the results of the microscopic examination, PCR and LAMP indicates the accuracy and reliability of these tests in the diagnosis of F. hepatica in sheep. However, molecular methods, especially the LAMP technique, are suggested because of their higher sensitivity and reliability for the diagnosis of F. hepatica even under field conditions.