RESUMEN
BACKGROUND: The dissemination of NDM-1 carbapenemases (New Delhi Metallo-ß-lactamase) is a global public health problem, mainly in developing countries. The aim of this study was to characterize the spread of NDM-producing bacteria in the Southern Brazilian states analyzing epidemiological, molecular, and antimicrobial susceptibility aspects. METHODS: A total of 10,684 carbapenem-resistant isolates of Enterobacterales, Pseudomonas spp. and Acinetobacter spp. obtained from several hospitals in eight cities in Southern Brazil were screened, and 486 NDM-producing bacteria were selected. RESULTS: The incidence varied from 0.5 to 77 cases/100.000 habitants. ST11, ST15, ST340 and ST674 were the most common in K. pneumoniae. A total of 5 plasmids were identified in one K. pneumoniae strain: Col440I, Col440II, IncFIA(HI1), IncFIB(K), IncFIB(pQil)/ IncFII(K), and IncR. CONCLUSIONS: The number of patients with NDM-producing bacteria has increased in Southern Brazil, whose gene is present in different plasmids, explaining the expansion of this enzyme.
Asunto(s)
Antibacterianos , Infecciones por Klebsiella , Humanos , Brasil/epidemiología , Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple/genética , beta-Lactamasas/genética , Carbapenémicos , Klebsiella pneumoniae/genética , Plásmidos , Pruebas de Sensibilidad Microbiana , Infecciones por Klebsiella/microbiologíaRESUMEN
Interactions between leaf-cutting ants, their fungal symbiont (Leucoagaricus) and the endophytic fungi within the vegetation they carry into their colonies are still poorly understood. If endophytes antagonistic to Leucoagaricus were found in plant material being carried by these ants, then this might indicate a potential mechanism for plants to defend themselves from leaf-cutter attack. In addition, it could offer possibilities for the management of these important Neotropical pests. Here, we show that, for Atta sexdens rubropilosa, there was a significantly greater incidence of Trichoderma species in the vegetation removed from the nests-and deposited around the entrances-than in that being transported into the nests. In a no-choice test, Trichoderma-infested rice was taken into the nest, with deleterious effects on both the fungal gardens and ant survival. The endophytic ability of selected strains of Trichoderma was also confirmed, following their inoculation and subsequent reisolation from seedlings of eucalyptus. These results indicate that endophytic fungi which pose a threat to ant fungal gardens through their antagonistic traits, such as Trichoderma, have the potential to act as bodyguards of their plant hosts and thus might be employed in a Trojan-horse strategy to mitigate the negative impact of leaf-cutting ants in both agriculture and silviculture in the Neotropics. We posit that the ants would detect and evict such 'malign' endophytes-artificially inoculated into vulnerable crops-during the quality-control process within the nest, and, moreover, that the foraging ants may then be deterred from further harvesting of 'Trichoderma-enriched' plants.
RESUMEN
We studied the foliicolous mycobiota associated with Coussapoa floccosa. This is a tree belonging to the Cecropiaceae, endemic to the Brazilian tropical seasonal semideciduous montane forest. It is listed as an endangered species because of habitat destruction. Until now no fungus has been recorded in association with this plant species. This paper describes six foliicolous fungi associated with this plant that were collected during a survey of the mycobiota occurring in a locality where a small population of C. floccosa was discovered. All fungi described here are new to science, namely Dennisiella coussapoae, Mycosphaerella coussapoae, Pseudoallosoma nervisequens (which also represents a newly proposed genus), Pseudocercospora coussapoae, Pseudocercospora atrofuliginosa and Tripospermum acrobaticum. The high proportion of taxonomic novelties revealed in this study reflects the general lack of mycological information for forest ecosystems in Brazil and also indicates that vulnerable plant species such as C. floccosa may harbor unique mycobiota. Such mycobiota may depend on their nearly extinct hosts and consequently can be equally endangered with extinction and therefore also deserve consideration for in situ and ex situ conservation.