A role for copper in protozoan grazing - two billion years selecting for bacterial copper resistance

2016 ◽  
Vol 102 (4) ◽  
pp. 628-641 ◽  
Author(s):  
Xiuli Hao ◽  
Freja Lüthje ◽  
Regin Rønn ◽  
Nadezhda A. German ◽  
Xuanji Li ◽  
...  
Keyword(s):  
Copper Resistance ◽  
Protozoan Grazing

Establishment of Copper Resistance in an ATP7B Knockout Cell Line

2016 ◽  
Vol 54 (12) ◽  
pp. 1343-1404
Author(s):  
S Reinartz Groba ◽  
V Sauer ◽  
CJ Niemietz ◽  
S Guttmann ◽  
L Fleischhauer ◽  
...  
Keyword(s):  
Cell Line ◽  
Copper Resistance

scholarly journals Copper Stress Targets the Rcs System To Induce Multiaggregative Behavior in a Copper-Sensitive Salmonella Strain

2010 ◽  
Vol 192 (23) ◽  
pp. 6287-6290 ◽  
Author(s):  
Lucas B. Pontel ◽  
Alejandro Pezza ◽  
Fernando C. Soncini
Keyword(s):  
Extracellular Polysaccharide ◽  
Copper Resistance ◽  
Copper Stress ◽  
Colanic Acid ◽  
Solid Media

ABSTRACT Salmonella ΔcuiD strains form mucoid colonies on copper-containing solid media. We show here that this multiaggregative behavior is caused by the Rcs-dependent induction of colanic acid extracellular polysaccharide. Deletion of cps operon genes in a ΔcuiD strain increased the sensitivity to copper, indicating a role for colanic acid in copper resistance.

scholarly journals Diversity and Geographical Structure of Xanthomonas citri pv. citri on Citrus in the South West Indian Ocean Region

2021 ◽  
Vol 9 (5) ◽  
pp. 945
Author(s):  
Olivier Pruvost ◽  
Damien Richard ◽  
Karine Boyer ◽  
Stéphanie Javegny ◽  
Claudine Boyer ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Host Range ◽  
Disease Surveillance ◽  
West Indian ◽  
Copper Resistance ◽  
The South ◽  
South West Indian Ocean ◽  
South West ◽  
Strain Collection ◽  
West Indian Ocean

A thorough knowledge of genotypic and phenotypic variations (e.g., virulence, resistance to antimicrobial compounds) in bacteria causing plant disease outbreaks is key for optimizing disease surveillance and management. Using a comprehensive strain collection, tandem repeat-based genotyping techniques and pathogenicity assays, we characterized the diversity of X. citri pv. citri from the South West Indian Ocean (SWIO) region. Most strains belonged to the prevalent lineage 1 pathotype A that has a wide host range among rutaceous species. We report the first occurrence of genetically unrelated, nonepidemic lineage 4 pathotype A* (strains with a host range restricted to Mexican lime and related species) in Mauritius, Moheli and Réunion. Microsatellite data revealed that strains from the Seychelles were diverse, grouped in three different clusters not detected in the Comoros and the Mascarenes. Pathogenicity data suggested a higher aggressiveness of strains of one of these clusters on citron (Citrus medica). With the noticeable exception of the Comoros, there was no sign of recent interisland movement of the pathogen. Consistent with this finding, the copL gene, a marker for the plasmid-borne copLAB copper resistance that was recently identified in Réunion, was not detected in 568 strains from any islands in the SWIO region apart from Réunion.

Occurrence oftcrB, a Transferable Copper Resistance Gene, in Fecal Enterococci of Swine

2010 ◽  
Vol 7 (9) ◽  
pp. 1089-1097 ◽  
Author(s):  
Raghavendra G. Amachawadi ◽  
Nick W. Shelton ◽  
Megan E. Jacob ◽  
Xiaorong Shi ◽  
Sanjeev K. Narayanan ◽  
...  
Keyword(s):  
Resistance Gene ◽  
Copper Resistance ◽  
Copper Resistance Gene

The role of calcium in the increase in flocculence of yeast growing in the presence of copper

1965 ◽  
Vol 162 (989) ◽  
pp. 555-566 ◽  
Keyword(s):  
Liquid Medium ◽  
Cell Cultures ◽  
Chloride Solution ◽  
Liquid Copper ◽  
Acquired Resistance ◽  
Calcium Chloride Solution ◽  
Copper Resistance ◽  
Liquid Cultures ◽  
Selection Of

Growth in the presence of inhibitory concentrations of copper enhances the tendency of yeast to flocculate. Many yeasts will not flocculate unless calcium is included in the growth medium and Guinness strain 522 used in the present work required a relatively large amount. Single cell cultures may undergo variation during subculture, resulting in the production of a large number of variants (Chester 1963). The cells of these variants differ considerably in their ability to adhere together. Flocculation variants of strain 522 differed among themselves in the amount of calcium necessary for flocculation, the most flocculent variants requiring least calcium. Washed cells of the more flocculent yeasts removed more calcium from a calcium chloride solution than did those with lesser powers of adhesion. In a copper medium con­taining calcium the more flocculent variants replaced the less flocculent. Calcium protected cells from copper and the more flocculent variants enjoyed most protection. All variants acquired resistance to copper during growth in the copper medium. Despite the selection of the more flocculent yeasts during growth in liquid medium, their copper resistance was less than that of the less flocculent yeasts. When calcium was added to the liquid copper medium, cultures developed less resistance. It is concluded that the less flocculent cells, having less protection by calcium, were exposed to what was effectively a greater concentration of copper and therefore became more resistant. This greater resistance did not enable these cells to compete with the flocculent cells in liquid cultures.

Genetic and transcriptional analysis of a novel plasmid-encoded copper resistance operon from Lactococcus lactis

Gene ◽  
2002 ◽  
Vol 297 (1-2) ◽  
pp. 241-247 ◽  
Author(s):  
Chun-Qiang Liu ◽  
Pilaiwan Charoechai ◽  
Nongpanga Khunajakr ◽  
Yi-Mo Deng ◽  
Widodo ◽  
...  
Keyword(s):  
Lactococcus Lactis ◽  
Copper Resistance ◽  
Transcriptional Analysis

Nitrification in activated sludge batch reactors is linked to protozoan grazing of the bacterial population

2005 ◽  
Vol 51 (9) ◽  
pp. 791-799 ◽  
Author(s):  
Penny Petropoulos ◽  
Kimberley A Gilbride
Keyword(s):  
Activated Sludge ◽  
Bacterial Population ◽  
Grazing Pressure ◽  
Nitrification Rate ◽  
Batch Reactors ◽  
Ammonia Oxidizing Bacteria ◽  
Bacterial Concentration ◽  
Batch Cultures ◽  
Protozoan Grazing ◽  
Swimming Bacteria

Protozoa feed upon free-swimming bacteria and suspended particles inducing flocculation and increasing the turnover rate of nutrients in complex mixed communities. In this study, the effect of protozoan grazing on nitrification was examined in activated sludge in batch cultures maintained over a 14-day period. A reduction in the protozoan grazing pressure was accomplished by using either a dilution series or the protozoan inhibitor cycloheximide. As the dilutions increased, the nitrification rate showed a decline, suggesting that a reduction in protozoan or bacterial concentration may cause a decrease in nitrification potential. In the presence of cycloheximide, where the bacterial concentration was not altered, the rates of production of ammonia, nitrite, and nitrate all were significantly lower in the absence of active protozoans. These results suggest that a reduction in the number or activity of the protozoans reduces nitrification, possibly by limiting the availability of nutrients for slow-growing ammonia and nitrite oxidizers through excretion products. Furthermore, the ability of protozoans to groom the heterotrophic bacterial population in such systems may also play a role in reducing interspecies competition for nitrification substrates and thereby augment nitrification rates.Key words: nitrification, activated sludge, protozoan grazing, ammonia-oxidizing bacteria, cycloheximide.

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