Development of Loop-Mediated Isothermal Amplification (LAMP) Assays for the Rapid Detection of Toxigenic Aspergillus flavus and A. carbonarius in Nuts.

Aspergillus species create major postharvest problems due to the food losses caused by their mere presence and the hazardous mycotoxins they produce, such as aflatoxin B1 (AFB1) and ochratoxin A (OTA). These mycotoxins are mainly produced by A. flavus and A. carbonarius, respectively. In this study, we developed a rapid detection method for the two aforementioned species based on loop-mediated isothermal amplification (LAMP). The primers were designed to target genes belonging to the mycotoxin clusters pks and aflT for A. carbonarius and A. flavus, respectively. Result visualization was carried out in real time via the detection of fluorescent signals. The method developed showed high sensitivity and specificity, with detection limits of 0.3 and 0.03 pg/reaction of purified DNA of A. carbonarius and A. flavus, respectively. The assays were further implemented on inoculated nuts, including pistachios and almonds, after one-step crude DNA extraction. These tests revealed a detection level of 0.5 spore/g that shows the effectiveness of LAMP as a rapid method for detecting potentially toxigenic Aspergillus spp. directly in food. The validation of the assays included tests on a larger scale that further confirmed their sensitivity and specificity, as well as enabling the production of ready-to-use LAMP prototype kits. These kits are easy to use and aim to simplify the screening of food samples in order to monitor the presence of specific Aspergillus contaminations.

Screening for cognitive impairment in older adults with hypertension: the HYPER-COG study.

Hypertension is a major risk factor for dementia. Yet, the most suitable cognitive screening test for hypertensive patients has yet to be identified. This study investigated cognitive impairment in hypertensive older adults and compared the discriminative ability of the most widely used cognitive screening tests. The study involved hypertensive patients aged 65+ without prior diagnosis of cognitive impairment, from the Hypertension Clinic of Careggi Hospital, Florence, Italy. Mini Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), MiniCog and Clock Drawing Test (CDT) were administered, using a comprehensive neuropsychological assessment as gold standard. The ROC curve analysis and the paired chi-square test were used to compare the discriminative ability, sensitivity and specificity for cognitive impairment of the different screening instruments. Cognitive impairment was diagnosed in 37% of 94 participants (mean age 76, 55% female), mainly involving attention and executive functions. The MoCA (AUC = 0.746), the MMSE (AUC = 0.689) and the MiniCog (AUC = 0.684) showed similar ability in detecting cognitive impairment, while the CDT had a poorer discriminative capacity (AUC = 0.535). The sensitivity of MoCA (80%) and of MMSE/MiniCog combination (74%) was higher in comparison with MiniCog alone (49%, p = 0.007 and 0.004, respectively), while MiniCog achieved the highest specificity (88%, p < 0.001 vs all). Cognitive impairment was detected in more than one-third of hypertensive older adults without prior diagnosis of dementia. MoCA, MMSE and MiniCog showed similar discriminative ability for cognitive impairment, with MoCa and MMSE showing greater sensitivity and MiniCog the highest specificity.