ABSTRACT Laboratory diagnosis of human leptospirosis usually relies on indirect methods exploring specific immune response. Isolation and identification of the involved strains are cumbersome, but can provide biological resources for pathogenic studies and relevant information for guiding prevention and control measures. The aim of the research we are hereby reporting was the characterization of Leptospira isolates obtained from humans and the environment in Uruguay. Blood cultures were performed from early samples of 302 Uruguayan patients, mainly rural workers, and from 36 water samples taken from their living or working environments. Eight human isolates and seven environmental isolates were obtained and analyzed by end point Polymerase Chain Reaction (PCR), Multilocus Variable Number of Tandem Repeat Analysis (MLVA) and other molecular methods. Human isolates corresponded to several serogroups and serovars of Leptospira interrogans and Leptospira kirschneri species, probably reflecting the infection with similar involved Leptospira species and serovars of an extended animal reservoir in rural settings of the country, mostly dedicated to meat and dairy production. Culture-positive patients were older than usually affected workers, and presented signs and symptoms of severe illness. A high organic and circulating bacterial burden may explain an easier positive result from these workers’ samples. Environmental isolates were mainly identified as Leptospira biflexa strains, with a single L. meyeri isolate of uncertain significance.

Mild cognitive impairment is understood as a cognitive deficit of insufficient severity to fulfil the criteria for Alzheimer's disease. Many studies have attempted to identify which cognitive functions are most affected by this type of impairment and which is the most sensitive neuropsychological test for early detection. This study investigated sustained and selective attention, processing speed, and the inhibition process using a sample of people divided into three groups mild cognitive impairment, Alzheimer disease and cognitively healthy controls selected and grouped based on their scores in the Mini Mental State Examination and Cambridge Cognitive Examination-revised. Three tests from the Cambridge Neuropsychological Test Automated Battery (Motor Screening Task, Stop Signal Task and Reaction time) were used as well as the d2 attention test. The results show that that participants with mild cognitive impairment and Alzheimer disease showed lower levels of concentration compared with the cognitively healthy controls group in the d2 test and longer reaction times in the Cambridge Neuropsychological Test Automated Battery, although the differences were not marked in the latter test. The impairments in basic cognitive processes, such as reaction time and sustained attention, indicate the need to take these functions into account in the test protocols when discriminating between normal aging and early and preclinical dementia processes.

El Deterioro Cognitivo Leve es entendido como un déficit cognitivo de curso insuficiente para cumplir criterios de demencia o Enfermedad de Alzheimer. Muchos estudios tratan de averiguar cuáles son las funciones cognitivas más afectadas en este tipo de deterioro, así como las pruebas neuropsicológicas más sensibles a la hora de detectarlos tempranamente. Este estudio tratará de estudiar la atención sostenida y selectiva, velocidad de procesamiento, así como el factor de inhibición, en una muestra de sujetos divididos en tres grupos (Deterioro Cognitivo leve, Demencia de Alzheimer y sujetos cognitivamente sanos), mediante el Mini Mental State Examination y la batería Cambridge Cognitive Examination-revised. Para ello utilizaremos las pruebas Cambridge Neuropsychological Test Automated Battery (Motor Screening Task, Stop Signal Task, Reaction Time) así como el test de atención d2. Los resultados muestran que aquellos sujetos con Deterioro Cognitivo Leve y Demencia de Alzheimer obtienen índices menores de concentración en comparación con los sujetos cognitivamente sanos en el test d2, así como mayores tiempos de reacción en las pruebas del Cambridge Neuropsychological Test Automated Battery, aunque estos no muestran diferencias tan marcadas. Este deterioro en los procesos cognitivos básicos, tales como el tiempo de reacción o la atención sostenida, nos indica la necesidad de tener en cuenta estas funciones en los protocolos de evaluación a la hora de discriminar entre el envejecimiento normal y los procesos tempranos de demencia.