Plasmid curing

Molnar et al. [69] studied antibacterial effect and plasmid curing property of several phenothaizines and tried to correlate these functions with respect to their chemical structure. They observed that diethazine, amitriptyline, and impipramine showed bacteriostatic and bactericidal effect on different bacteria. Chlorpromazine sulfoxide and fluorescein were ineffective even at 1000 Ag/ml. The antibacterial compounds deleted at 40-70% frequency the F lac-t- plasmid of Escherichia coli K12 Le-140. Similar plasmid elimination potentiality by phenothiazines was reported by the same group of authors in 1982 [72],... 

In 1999, Radhakrishnan et al. [88] reported the plasmid curing effect of thioridazine on 12 multiple antibiotic and thioridazine resistant bacteria. 

Table I Activity of Some Naturally Occurring Glycopeptides Agaimt a Typical VanA Enterococcus and Its Plasmid Cured CIycopcpti k Scnsitive Derivative...

The phosphorus concentration at the surface of a plasmid-cured Thermus strain was three times lower compared to the wild strain, suggesting that the presence of plasmids influences cell-surface characteristics. ... 

The first whole genome sequence of a Lact. sakei strain was that reported in 2005 for the 1,884-kb chromosome of Lact. sakei 23K, a plasmid cured strain derived from a sausage isolate (Chaillou et al. 2005). Recently, the draft genome sequence of a second strain Lact. sakei LS25, a commercial starter for fermented sausage) has also been published (McLeod et al. 2013). The sequence reported a 2015-kb chromosome and a 20.5-kb plasmid. 

To facilitate our work on plasmids with no known phenotype, we have developed a method for the use and detection of biotinylated probes in colony hybridization. It is suitable both for the detection of rare positive hybridization events over a background of nonreactive colonies and for the detection of nonhybridizing colonies in a population containing sequences homologous to the probe. The latter capability could be useful in such applications as the detection of cured (i.e., plasmid-free) cells in a bacterial population containing plasmids. 

Mutator plasmid mutation rate of host is enhanced curing strain of plasmid stabilizes the mutation Selifonova, 2001... 

Aside from the expression of histidine mutations that are easily detected, other properties have been built into the Salmonella strains by mutation to increase their sensitivity. The strains cure defective in DNA excision repair (uvrB). In this case, the increased sensitivity probably is due to the failure to remove some DNA adducts that could lead to mutation. The strains also possess a mutation (rfa) that removes part of the lipopolysaccharide barrier of the bacterial cell wall and thereby makes the cells more permeable to some chemicals. Finally, Salmonella strains TA98 and TA100 contain the R-factor plasmid pkMIOl,277 which increases sensitivity probably by increasing the activity of an error-prone DNA-repair system. 

The result suggested that thioridazine was able to eliminate different antibiotic resistances singly or jointly in Escherichia coli strains and Shigella flexneri 6 BDC1 quite efficiently, but had a much weaker effect on Vibrio cholerae (Table 42). The pattern of elimination further indicated that penicillin, ampicillin, and amoxicillin were determined by a single plasmid in these bacteria. It seems that effective elimination depended on the curing concentrations, which were close to the MIC value of thioridazine for any... 

A Hethylomonas sp (BI.10) capable of utilizing butylate also contained a plasmid DNA band (pSMB 4) that was estimated to be 50 kb. This plasmid was very stable and was not cured by hot or cold temperatures and had to be cured with acridine orange (46). Con jugjal matings between Herb donor (Sm ) and herb recipient (Tc Km ) cells produced Herb transconjugants (Sm Tc Km ) that contained pSMB 4 and turned red on the butylate-TTC medium (46) to demonstrate transfer of butylate-degrading ability. 

If a yeast virus or plasmid (or the mitochodrial DNA genome) is cured from a strain, they will not return or arise again unless they are... 

---