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Papers by jenny llanos
PubMed, 2000
Surface hydrophobicity is a widely distributed characteristic among human bacterial pathogens pla... more Surface hydrophobicity is a widely distributed characteristic among human bacterial pathogens playing an important role in microbes retention by the incurrent siphon of a marine bivalve. Feeding retention experiments with the bivalve Mesodesma donacium was done with hydrophobic strains alone (Staphylococcus aureus, Salmonella paratyphi, Vibrio cholerae) or with mixed cultures using a hydrophilic strain (Aeromonas hydrophila). Results showed that hydrophobic bacteria are retained in greater numbers than hydrophilic bacteria. This difference is statistically significant. Hydrophobic strains also survive longer than hydrophilic ones in sea water. Surface hydrophobicity is to be considered as a factor influencing concentration of hydrophobic pathogens by filter feeding molluscs.
Current Microbiology, 2000
Thirty thermophilic strains isolated from heavy metal-rich hydrothermal vent sites at Lau Basin w... more Thirty thermophilic strains isolated from heavy metal-rich hydrothermal vent sites at Lau Basin were tested for their susceptibility to cadmium, zinc, cobalt, and nickel. The 14 aerobic spore formers belonging to the genus Bacillus, 6 anaerobic fermenters from the order Thermotogales, and 10 anaerobic sulfur reducers from the order Thermococcales could be clearly distinguished according to their metal susceptibilities. The Thermococcales were found to exhibit the highest resistance to cadmium and zinc, whereas Thermotogales were highly sensitive to these metals. In contrast, the Thermotogales displayed the highest resistance to cobalt ions. No clear distinction could be established between the metal susceptibilities of these strains and seven reference organisms used for comparative studies. Cadmium resistance, slightly inducible in some cadmium-resistant bacilli, was not plasmid mediated. The amount of cadmium immobilized by the Thermotogales was related to their level of resistance to this metal.
Investigaciones marinas, 2002
A simple bacteriological analysis for accompanying culturable microflora from different regions o... more A simple bacteriological analysis for accompanying culturable microflora from different regions of the body of Argopecten purpuratus showed a rather atypical bacteria considering that farming is done in the seawater column. High numbers of Vibrio strains, Gram-positive cocci, and sporeformers were present. Also members of the Enterobacteriaceae family were isolated.
Research in Microbiology, 2001
Superoxide dismutases (SODs) are vital components that defend against oxidative stress through de... more Superoxide dismutases (SODs) are vital components that defend against oxidative stress through decomposition of superoxide radical. Escherichia coli contains two highly homologous SODs, a manganese-and an iron-containing enzyme (Mn-SOD and Fe-SOD, respectively). In contrast, a single Mn-SOD is present in Bacillus subtilis. In E. coli, the absence of SODs was found to be associated with an increased sensitivity to cadmium, nickel and cobalt ions. Mutants lacking either sodA or sodB exhibited metal resistance to levels comparable to that of the wild-type strain. Although soddeficient mutant cells were more resistant to zinc than their wild-type counterpart, no differences between the strains were observed in the presence of copper. In B. subtilis, the sodA mutation had no effect on cadmium and copper resistance. These results suggest that intracellular generation of superoxide by cadmium, nickel and cobalt is toxic in E. coli. They support the participation of sod genes in its protection against metal stress. 2001 Éditions scientifiques et médicales Elsevier SAS Escherichia coli / Bacillus subtilis / superoxide dismutase / oxidative stress / heavy metal resistance
Cahiers De Biologie Marine, 1997
PubMed, 2000
Surface hydrophobicity is a widely distributed characteristic among human bacterial pathogens pla... more Surface hydrophobicity is a widely distributed characteristic among human bacterial pathogens playing an important role in microbes retention by the incurrent siphon of a marine bivalve. Feeding retention experiments with the bivalve Mesodesma donacium was done with hydrophobic strains alone (Staphylococcus aureus, Salmonella paratyphi, Vibrio cholerae) or with mixed cultures using a hydrophilic strain (Aeromonas hydrophila). Results showed that hydrophobic bacteria are retained in greater numbers than hydrophilic bacteria. This difference is statistically significant. Hydrophobic strains also survive longer than hydrophilic ones in sea water. Surface hydrophobicity is to be considered as a factor influencing concentration of hydrophobic pathogens by filter feeding molluscs.
Current Microbiology, 2000
Thirty thermophilic strains isolated from heavy metal-rich hydrothermal vent sites at Lau Basin w... more Thirty thermophilic strains isolated from heavy metal-rich hydrothermal vent sites at Lau Basin were tested for their susceptibility to cadmium, zinc, cobalt, and nickel. The 14 aerobic spore formers belonging to the genus Bacillus, 6 anaerobic fermenters from the order Thermotogales, and 10 anaerobic sulfur reducers from the order Thermococcales could be clearly distinguished according to their metal susceptibilities. The Thermococcales were found to exhibit the highest resistance to cadmium and zinc, whereas Thermotogales were highly sensitive to these metals. In contrast, the Thermotogales displayed the highest resistance to cobalt ions. No clear distinction could be established between the metal susceptibilities of these strains and seven reference organisms used for comparative studies. Cadmium resistance, slightly inducible in some cadmium-resistant bacilli, was not plasmid mediated. The amount of cadmium immobilized by the Thermotogales was related to their level of resistance to this metal.
Investigaciones marinas, 2002
A simple bacteriological analysis for accompanying culturable microflora from different regions o... more A simple bacteriological analysis for accompanying culturable microflora from different regions of the body of Argopecten purpuratus showed a rather atypical bacteria considering that farming is done in the seawater column. High numbers of Vibrio strains, Gram-positive cocci, and sporeformers were present. Also members of the Enterobacteriaceae family were isolated.
Research in Microbiology, 2001
Superoxide dismutases (SODs) are vital components that defend against oxidative stress through de... more Superoxide dismutases (SODs) are vital components that defend against oxidative stress through decomposition of superoxide radical. Escherichia coli contains two highly homologous SODs, a manganese-and an iron-containing enzyme (Mn-SOD and Fe-SOD, respectively). In contrast, a single Mn-SOD is present in Bacillus subtilis. In E. coli, the absence of SODs was found to be associated with an increased sensitivity to cadmium, nickel and cobalt ions. Mutants lacking either sodA or sodB exhibited metal resistance to levels comparable to that of the wild-type strain. Although soddeficient mutant cells were more resistant to zinc than their wild-type counterpart, no differences between the strains were observed in the presence of copper. In B. subtilis, the sodA mutation had no effect on cadmium and copper resistance. These results suggest that intracellular generation of superoxide by cadmium, nickel and cobalt is toxic in E. coli. They support the participation of sod genes in its protection against metal stress. 2001 Éditions scientifiques et médicales Elsevier SAS Escherichia coli / Bacillus subtilis / superoxide dismutase / oxidative stress / heavy metal resistance
Cahiers De Biologie Marine, 1997