Many Gram-negative plant pathogenic bacteria employ a N-acylhomoserine lactone (AHL)-based quorum sensing (QS) system to regulate their virulence traits. A sustainable biocontrol strategy has been developed using quorum quenching (QQ) bacteria to interfere with QS and protect plants from pathogens. Here, the prevalence and the diversity of QQ strains inhabiting tobacco leaf surfaces were explor...

Endophytic bacteria were isolated from stems of Eucalyptus spp (Eucalyptus citriodora, E. grandis, E. urophylla, E. camaldulensis, E. torelliana, E. pellita, and a hybrid of E. grandis and E. urophylla) cultivated at two sites; they were characterized by RAPD and amplified rDNA restriction analysis (ARDRA). Endophytic bacteria were more frequently isolated from E. grandis and E. pellita. The 76...

Using a polyphasic approach (including cellular protein and fatty acid analysis, biochemical characterization, 16S ribosomal DNA sequencing, and DNA-DNA hybridizations), we characterized 51 bacterial isolates recovered from respiratory secretions of cystic fibrosis (CF) patients. Our analyses showed that 24 isolates belong to taxa that have so far not (or only rarely) been reported from CF pati...

Topical chemoprophylaxis of extensive burns with silver sulphadiazine cream led to a large increase in the proportion of sulphadiazine-resistant Gram-negative bacilli in a burns unit. When all sulphonamide treatment in the ward was stopped; the incidence of sulphonamide-resistant strains fell back to levels similar to those recorded when silver sulphadiazine treatment was introduced. This was a...

Ultraviolet radiation can damage biomolecules, with detrimental or even lethal effects for life. Even though lower wavelengths are filtered by the ozone layer, a significant amount of harmful UV-B and UV-A radiation reach Earth's surface, particularly in high altitude environments. high-altitude Andean lakes (HAALs) are a group of disperse shallow lakes and salterns, located at the Dry Central ...

In the January 2007 issue of the Journal of Clinical Microbiology, Jones et al. reported a multicenter study of the tigecycline disk diffusion breakpoints of Acinetobacter spp., including multidrug-resistant (MDR) strains. The authors concluded that a breakpoint zone diameter of 16/ 12 mm to define susceptibility/resistance, respectively, instead of those proposed by the U.S. Food and Drug Admi...

The construction of artificial biofilms with defined internal architectures is described. Bacterial cells are suspended in a low conductivity medium, guided to specific areas in a microelectrode array by dielectrophoresis (DEP), and then immobilised using the flocculating agent poly(ethylenimine). Multispecies biofilms can be constructed by introducing different species at different times. The ...

Military medical facilities treating patients injured in Iraq and Afghanistan have identified a large number of multidrug-resistant (MDR) Acinetobacter baumannii isolates. In order to anticipate the impact of these pathogens on patient care, we analyzed the antibiotic resistance genes responsible for the MDR phenotype in Acinetobacter sp. isolates collected from patients at the Walter Reed Army...

Ochratoxin A (OTA) is a mycotoxin with a main nephrotoxic activity contaminating several foodstuffs. In the present report, five soil samples collected from OTA-contaminated vineyards were screened to isolate microorganisms able to biodegrade OTA. When cultivated in OTA-supplemented medium, OTA was converted in OTα by 225 bacterial isolates. To reveal clonal relationships between isolates, mole...

The polyhydroxyalkanoic acid (PHA) biosynthetic gene locus was cloned and characterized from an Acinetobacter sp. isolated from activated sludge. Nucleotide sequence analysis identified three clustered genes, phaAAc (encoding a beta-ketothiolase), phaBAc (encoding an acetoacetyl coenzyme A reductase), and phaCAc (encoding a PHA synthase). In addition, an open reading frame (ORF1) with potential...