RESUMO
Most members of the Pseudoalteromonas genus have been isolated from living surfaces as members of epiphytic and epizooic microbiomes on marine macroorganisms. Commonly Pseudoalteromonas isolates are reported as a source of bioactive exoproducts, i.e., secondary metabolites, such as exopolymeric substances and extracellular enzymes. The experimental conditions for the production of these agents are commonly associated with sessile metabolic states such as biofilms or liquid cultures in the stationary growth phase. Despite this, the molecular mechanisms that connect biofilm formation and the biosynthesis of exoproducts in Pseudoalteromonas isolates have rarely been mentioned in the literature. This review compiles empirical evidence about exoproduct biosynthesis conditions and molecular mechanisms that regulate sessile metabolic states in Pseudoalteromonas species, to provide a comprehensive perspective on the regulatory convergences that generate the recurrent coexistence of both phenomena in this bacterial genus. This synthesis aims to provide perspectives on the extent of this phenomenon for the optimization of bioprospection studies and biotechnology processes based on these bacteria.
Assuntos
Pseudoalteromonas , Biofilmes , Pseudoalteromonas/genéticaRESUMO
We reviewed 18 cases of histoplasmosis in patients at risk for the acquired immunodeficiency syndrome seen at two New York City hospitals in the past 3 1/2 years. Seventeen patients were Hispanic, including 13 born in Puerto Rico and three in South America. Clinical presentation was subacute, with high fever, weight loss, and mild respiratory symptoms with well-maintained gas exchange. Five patients had normal chest roentgenograms. The most common chest roentgenographic abnormality was diffuse small nodules. A rapid diagnosis was established histologically in 72 percent of patients, most commonly by transbronchial lung biopsy; cultures were positive in 94 percent of patients while serology was positive in five of six patients. Mycobacterium tuberculosis was a concurrent, often unrecognized, pathogen in six cases. Most patients responded to amphotericin therapy. Histoplasmosis may represent an early sign of altered host immunity in the acquired immunodeficiency syndrome.