Rapid and convenient detection of <i>Weissella ceti</i> with loop-mediated isothermal amplification

Weissella ceti , a Gram‐positive lactic acid bacterium, has emerged as a novel pathogen causing Weissellosis in rainbow trout ( Oncorhynchus mykiss ). Until now, it has not been easy to distinguish W. ceti from other pathogens by the symptoms of the infected rainbow trout, especially at the primary stage of infection. Thus, a convenient and rapid identification method is needed to determine this pathogen. The current study demonstrated loop-mediated isothermal amplification (LAMP) superior specificity and sensitivity for W. ceti . Primers were designed targeting the hemolysin A gene, and LAMP was accomplished within 30 min at 63 ℃. The minimum concentration of LAMP for W. ceti DNA was 5.9 x 10 -6 ng/μl, which was 100 times more sensitive than traditional PCR. LAMP confirmed the high specificity for W. ceti , whereas the other six pathogens were negative reactions. Furthermore, the effectiveness of LAMP was also demonstrated in simulated clinical samples. Based on the results, LAMP was rapid and convenient for point-of-care testing to diagnose W. ceti infections.