Search

This study determined the occurrence of potentially pathogenic free-living amoebae (FLA) and bacteria associated with amoebae in air-conditioning cooling towers in southern Brazil. Water samples were collected from 36 cooling systems from air-conditioning in the state of Rio Grande do Sul, Brazil. The organisms were identified using polymerase chain reaction (PCR) and sequencing automated. The results showed that these aquatic environments, with variable temperature, are potential 'hot spots' for emerging human pathogens like free-living amoebae and bacteria associated. In total, 92% of the cooling-tower samples analyzed were positive for FLA, and Acanthamoeba was the dominant genus by culture and PCR. Amoebal isolates revealed intracellular bacteria in 39.3% of them and all were confirmed as members of the genus Pseudomonas. The results obtained show the important role of cooling towers as a source of amoebae-associated pathogens. [ABSTRACT FROM AUTHOR]

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article discusses various presentations made at the 8th International Symposium on Testate Amoebae, held in São Paulo, Brazil, during September 12-14, 2016. Topics discussed at the event included the Neoproterozoic diversification of eukaryotes; ecology of planktonic testate amoebae in the floodplains of Brazil; and taxonomy and transcriptomics in Amoebozoa. Awards were also presented by the International Society of Protistologist (ISOP).

Population densities in different sites are frequently observed to fluctuate synchronously, a phenomenon termed temporal coherence. The two main causes of temporal coherence are dispersal and the effects of a regional factor (Moran effect) that influence each of the populations similarly. If synchronous patterns are observed, it is possible to infer that there is a regional process (e.g., climate) exerting a uniform influence over the entire region. Here, we evaluate patterns of temporal coherence in total densities of zooplankton groups. Data were gathered at 11 sites in the Corumbá Reservoir (Central Brazil) between 1996 and 2000 ( n = 27 months). These sites were distributed in the main channel, arms, and tributaries of the reservoir. Reservoir-wide correlations (as estimated by the average Spearman rank correlation between temporal trajectories of abundances) were low (−0.01, 0.06, 0.23, and 0.14 for cladocerans, copepods, rotifers, and testate amoebae, respectively). In general, high temporal coherence was detected only between geographically adjacent sites and/or between sites with similar limnological characteristics. Contrary to many recent studies, these results illustrate that, in a small geographic area (i.e., a single reservoir of approximately 65 km2), local processes may override the effects of regional processes or dispersal. Moreover, they demonstrate that the lack of regional trajectories (i.e., time series of population densities with asynchronous patterns of fluctuation) should be considered in interpreting results obtained in long-term studies or monitoring programs based on a single site per ecosystem. [ABSTRACT FROM AUTHOR]

The article presents a study on isolation of Naegleria australiensis and N. philippinensis in the Monjolinho River, Brazil. It mentions the importance of Naegleria genus was worldwide recognized 56 years after its discovery, due to the rising of the pathogenic specie Naegleda fowled. It reports from the 47 species already described, only four of them have been associated to encephalitis: N. fowled capable of infecting humans and N australiensis, N. philippinensis infecting mice models.