Photosynthetic performance and leaf water potential of gulupa (Passiflora edulis Sims, Passifloraceae) in the reproductive phase in three locations in the colombian andes / Desempeño fotosintético y potencial hídrico foliar de gulupa (Passiflora edulis Sims, Passifloraceae) en estado reproductivo en tres localidades de los Andes colombianos

Gulupa, Passiflora edulis Sims (Passifloraceae), is an important fruit due to its organoleptic and nutritional characteristics and its demand in the international market; however, very few studies have been conducted for studying its Ecophysiology. Until now, this crop has spread throughout the country through empirical knowledge without data that indicate the zones that are more suitable for its cultivation. For this reason, gas exchange, chlorophyll fluorescence (photosystem II operating efficiency and maximum quantum efficiency of photosystem II photochemistry) and leaf water potential were measured in three different locations of Cundinamarca department (Chia [2610 m a.s.l., 14 °C], Granada [2230 m a.s.l., 15 °C] and Tena [2090 m a.s.l., 17 °C]), whose climatic conditions were monitored with meteorological stations to evaluate the physiologic performance in each location related to the environmental factors. The results indicate that, even though the photosynthetic capacity was similar and high in Granada and Tena, the water status of the plant, the stomatal control of water loss and recovery of photosystems during the night were more efficient in Granada (p < 0.05). In Tena, the small differences between day and night temperature, humidity, and vapor pressure deficit (VPD) would limited the night water recovery in the plants. Meanwhile, in Chia, the increase of VPD during the day and the low temperatures would decreased the water potential both during the day and during the night, as well as the recovery of photosystem II. Therefore, in conclusion the climatic conditions similar to Granada, which are 18/13 °C day/night, a VPD close to 0.5 KPa, and radiation that did not exceed 1000 μmol photons/m²s favored the good physiological performance of gulupa.

La gulupa, Passiflora edulis Sims (Passifloraceae) es un frutal importante debido a sus características organolépticas, nutricionales y su demanda en el mercado internacional; sin embargo, existen muy pocos estudios relacionados con su ecofisiología. Hasta el momento, el cultivo se ha extendido a través del país por medio de conocimiento empírico sin tener datos que sustenten las zonas más apropiadas para su cultivo. Por esta razón, en el presente estudio se midió el intercambio de gases, la fluorescencia de la clorofila (factor de eficiencia del fotosistema II y eficiencia cuántica fotoquímica máxima del fotosistema II) y el potencial hídrico foliar en tres localidades diferentes del departamento de Cundinamarca (Chía [2610 m s.n.m., 14 °C], Granada [2230 m s.n.m., 15 °C] y Tena [2090 m s.n.m., 17 °C]), cuyas condiciones climáticas fueron monitoreadas con estaciones meteorológicas para evaluar el desempeño fisiológico en cada localidad y relacionarlo con los factores ambientales. Los resultados indican que aunque la capacidad fotosintética fue alta y similar en Granada y Tena, el estado hídrico de la planta, el control estomático de la pérdida de agua y la recuperación de los fotosistemas durante la noche fueron más eficientes en Granada (p < 0,05). En Tena, la estrecha diferencia entre los valores día/noche de temperatura, humedad y déficit de presión de vapor (DPV) limitarían la recuperación hídrica de la planta, mientras que en Chía el aumento de DPV en el día, y las bajas temperaturas disminuirían el potencial hídrico, tanto durante el día como durante la noche, así como la recuperación del fotosistema II. Por tanto, en conclusión, condiciones climáticas cercanas a las de Granada; 18/13 °C día/noche, DPV de 0,5 KPa, y una radiación que no exceda los 1000 μmol fotones/ m²s favorecen el buen desempeño de la planta.

Rickettsia parkeri: a Rickettsial pathogen transmitted by ticks in endemic areas for spotted fever rickettsiosis in southern Uruguay / Rickettsia parkeri: patógeno rickettsial transmitido por garrapatas en áreas endémicas de rickettsiosis por fiebre manchada en el sur de Uruguay

At first Rickettsia conorii was implicated as the causative agent of spotted fever in Uruguay diagnosed by serological assays. Later Rickettsia parkeri was detected in human-biting Amblyomma triste ticks using molecular tests. The natural vector of R. conorii, Rhipicephalus sanguineus, has not been studied for the presence of rickettsial organisms in Uruguay. To address this question, 180 R. sanguineus from dogs and 245 A. triste from vegetation (flagging) collected in three endemic localities were screened for spotted fever group (SFG) rickettsiosis in southern Uruguay. Tick extracted DNA pools were subjected to PCR using primers which amplify a fragment of the rickettsial gltA gene. Positive tick DNA pools with these primers were subjected to a second PCR round with primers targeting a fragment of the ompA gene, which is only present in SFG rickettsiae. No rickettsial DNA was detected in R. sanguineus. However, DNA pools of A. triste were found to be positive for a rickettsial organism in two of the three localities, with prevalences of 11.8% to 37.5% positive pools. DNA sequences generated from these PCR-positive ticks corresponded to R. parkeri. These findings, joint with the aggressiveness shown by A. triste towards humans, support previous data on the involvement of A. triste as vector of human infections caused by R. parkeri in Uruguay.

Inicialmente, Rickettsia conorii fue señalada como el agente causal de la fiebre manchada en Uruguay, diagnosticada mediante pruebas serológicas. Posteriormente, Rickettsia parkeri fue detectada mediante técnicas moleculares en garrapatas Amblyomma triste colectadas sobre humanos. El vector natural de R. conorii, Rhipicephalus sanguineus, no ha sido estudiado en cuanto a rickettsias en Uruguay. Para abordar este tema, 180 R. sanguineus fueron colectados sobre perros y 245 A. triste sobre vegetación en tres localidades consideradas endémicas para fiebres manchadas en el sur de Uruguay. El ADN de las garrapatas fue extraído en pools y sometido a una primera PCR utilizando cebadores que amplifican un fragmento del gen gltA, presente en prácticamente todas las especies de Rickettsia. Las muestras positivas fueron sometidas a una segunda PCR con cebadores que amplifican un fragmento del gen ompA, presente sólo en rickettsias del grupo de las fiebres manchadas (GFM). No se detectó ADN rickettsial en R. sanguineus. Sin embargo, muestras de A. triste fueron positivas a rickettsiales en dos de las tres localidades estudiadas, con prevalencias de pools positivos del 11.8 y 37.5% respectivamente. La secuenciación del ADN evidenció la presencia de R. parkeri. Basados en estos resultados junto a los anteriores y la agresividad de A. triste hacia los humanos, se concluye que esta garrapata es vector de rickettsiosis humana por R. parkeri en Uruguay.

Rickettsia parkeri: a Rickettsial pathogen transmitted by ticks in endemic areas for spotted fever rickettsiosis in southern Uruguay.

At first Rickettsia conorii was implicated as the causative agent of spotted fever in Uruguay diagnosed by serological assays. Later Rickettsia parkeri was detected in human-biting Amblyomma triste ticks using molecular tests. The natural vector of R. conorii, Rhipicephalus sanguineus, has not been studied for the presence of rickettsial organisms in Uruguay. To address this question, 180 R. sanguineus from dogs and 245 A. triste from vegetation (flagging) collected in three endemic localities were screened for spotted fever group (SFG) rickettsiosis in southern Uruguay. Tick extracted DNA pools were subjected to PCR using primers which amplify a fragment of the rickettsial gltA gene. Positive tick DNA pools with these primers were subjected to a second PCR round with primers targeting a fragment of the ompA gene, which is only present in SFG rickettsiae. No rickettsial DNA was detected in R. sanguineus. However, DNA pools of A. triste were found to be positive for a rickettsial organism in two of the three localities, with prevalences of 11.8% to 37.5% positive pools. DNA sequences generated from these PCR-positive ticks corresponded to R. parkeri. These findings, joint with the aggressiveness shown by A. triste towards humans, support previous data on the involvement of A. triste as vector of human infections caused by R. parkeri in Uruguay.

Rickettsia felis in Ctenocephalides felis from Argentina.

This article reports on the detection of Rickettsia felis in Argentina in Ctenocephalides felis fleas collected from a dog and analyzed by polymerase chain reaction (PCR) amplification and DNA sequencing.

Detection of Alpha and Gamma-Proteobacteria in Amblyomma triste (Acari: Ixodidae) from Uruguay.

Amblyomma triste is the most prevalent tick species reported in human tick bites in Uruguay and has been found to be infected with Rickettsia parkeri, but no other microorganisms have been reported from this tick. A sample of 254 adults of A. triste was collected by flagging on vegetation in suburban areas in southern Uruguay. Pools of five ticks were assembled and a screening for the DNA from the resulting 51 pools was realized by PCR assays using primers for amplifying a fragment of 16S rRNA gene for members of Anaplasmataceae. Seventeen pools were positive (33%) and the sequenciation of the gene fragment amplified revealed the presence of a putative new Alpha-Proteobacterium (denominated Atri-uru). The phylogenetic analysis showed that this microorganism is closely related to the symbiont of I. ricinus denominated 'Candidatus Midichloria mitochondrii' and other associated organisms. This rickettsial symbiont of ticks is included in a recent new clade proposed for the Alpha subclass of the Proteobacteria. The discovery of this bacterium in A. triste is the first evidence of this group of Rickettsiales detected in the Genus Amblyomma, and the first record in South America. Also, in two of 17 positive samples a Gamma-Proteobacterium related to Francisella-like organisms was detected.

Prevalence of Rickettsia felis in Ctenocephalides felis and Ctenocephalides canis from Uruguay.

Our aim was to determine the presence of Rickettsia spp. in 66 fleas from Uruguay. Rickettsial DNA was amplified using gltA and ompB PCR primers. Rickettsia spp. were found in 41% of the fleas (25 Ctenocephalides felis and 2 Ctenocephlides canis). Sequences resulted in the identification of Rickettsia felis and four genotypes closely related to this species (Rickettsia sp. TwKM03, California 2, Hf187, and RF2125). The presence of R. felis in fleas from Uruguay in was demonstrated. This is the second species of Rickettsia identified in Uruguay in the past 2 years using molecular approaches, and it is helping to clarify the etiology of rickettsial diseases in the region.