Escherichia coli cells penetrated by chrysotile fibers are transformed to antibiotic resistance by incorporation of exogenous plasmid DNA

2002 ◽  
Vol 60 (4) ◽  
pp. 461-468 ◽  
Author(s):  
Yoshida N. ◽  
Kodama K. ◽  
Nakata K. ◽  
Yamashita M. ◽  
Miwa T.
1984 ◽  
Vol 48 (3) ◽  
pp. 657-662 ◽  
Author(s):  
Michio HIMENO ◽  
Toshihiro SHIBATA ◽  
Yoshio KAWAHARA ◽  
Yuhji HANAOKA ◽  
Tohru KOMANO

1985 ◽  
Vol 5 (4) ◽  
pp. 714-720 ◽  
Author(s):  
R S Kucherlapati ◽  
J Spencer ◽  
P D Moore

Two plasmids containing noncomplementing and nonreverting deletions in a bacterial phosphotransferase gene conferring resistance to neomycin (Neor) were incubated with human cell extracts, and the mixtures were used to transform recombination-deficient (recA-) Escherichia coli cells. We were able to obtain Neor colonies at a frequency of 2 X 10(-3). This frequency was 100 to 1,000 times higher than that obtained with no extracts. The removal of riboadenosine 5'-triphosphate, Mg2+, or deoxynucleoside triphosphates from the reaction mixture severely reduced the yield of Neor colonies. Examination of plasmid DNA from the Neor colonies revealed that they resulted from gene conversion and reciprocal recombination. On the basis of these results, we conclude that mammalian somatic cells in culture have the enzymatic machinery to catalyze homologous recombination in vitro.


1985 ◽  
Vol 5 (4) ◽  
pp. 714-720
Author(s):  
R S Kucherlapati ◽  
J Spencer ◽  
P D Moore

Two plasmids containing noncomplementing and nonreverting deletions in a bacterial phosphotransferase gene conferring resistance to neomycin (Neor) were incubated with human cell extracts, and the mixtures were used to transform recombination-deficient (recA-) Escherichia coli cells. We were able to obtain Neor colonies at a frequency of 2 X 10(-3). This frequency was 100 to 1,000 times higher than that obtained with no extracts. The removal of riboadenosine 5'-triphosphate, Mg2+, or deoxynucleoside triphosphates from the reaction mixture severely reduced the yield of Neor colonies. Examination of plasmid DNA from the Neor colonies revealed that they resulted from gene conversion and reciprocal recombination. On the basis of these results, we conclude that mammalian somatic cells in culture have the enzymatic machinery to catalyze homologous recombination in vitro.


2020 ◽  
Vol 97 (3) ◽  
pp. 258-264
Author(s):  
Nadejda A. Selyanskaya ◽  
Sergey O. Vodop'yanov ◽  
Violetta A. Rykova ◽  
Elena P. Sokolova

Aim. Detection of SXT elements in cholera vibrios O1 and nonO1/nonO139 serogroups and study of the effectiveness of their conjugative transmission to Escherichia coli cells.Materials and methods. In conjugation experiments, Vibrio cholerae O1 El Tor (3) and V. cholerae nonO1/ nonO139 (3) strains were used as donors. Donor strains, recipients, and transconjugants were tested in realtime PCR for sensitivity to antibiotics and for the presence of drug resistance genes and integrase gene (int). Electrophoresis was carried out on a 0.7% agarose gel with ethidium bromide staining.Results. Resistance to chloramphenicol, trimethoprim/sulfamethoxazole, streptomycin was transmitted in conjugation experiments with a frequency of 2.1 × 10–9–7.1 × 10–9. The genes int and dfrA1 (resistance to trimethoprim/sulfamethoxazole) were found in most V. cholerae strains, and were stably transmitted to E. coli QD Rif r cells and in reverse crosses of V. cholerae O1 El Tor 5879 Nalr .Conclusion. The detection of the SXT element in V. cholerae strains and its successful horizontal transfer emphasize the need to detect such mobile genetic elements to control the spread of antibiotic resistance in V. cholerae.


2021 ◽  
Vol 14 (4) ◽  
pp. 1607-1612
Author(s):  
Geetika Gupta

Globally antibiotic resistance has become a major concern, which warrants the real time monitoring for resistance in very common pathogenic organisms. E. coli is normal micro flora in humans, but sometimes it can be pathogenic. For the observation and increment of antimicrobial resistance among pathogen, E. coli has been one of the important pathogens. It is present everywhere in fecal, water, food etc., if resistant E. coli will present in the environment that it can be transferrable anywhere through water, fecal food, animals and humans. This is very dangerous to living beings. This study was designed on status of antibiotic resistance in E. coli isolates in human kids and animal kids, both. Newborns are affected more because of poor or lack of immune system. In this study, fecal materials were used as sample material collected from goat kids (0-3 months) and human children (up to 3 years) residing in same local area. Fifteen fecal samples were collected from human children (up to 3 years) and goat kids (0-3 months) in each case to study the risk of transmission of resistance in E. coli isolates. PCR was conducted on genomic DNA isolates for the presence of usp A gene of E. coli. Multiplex PCR were conducted on plasmid DNA isolates for the resistance specific genes. Molecular resistance results in goat kids isolates showed resistance to antibiotics with tetracycline, sulphonamide, gentamycin, streptomycin and cephalothin to the level of 93.33, 53.33, 46.66, 13.33 & 6.66% respectively, whereas, human E. coli isolates were showed the highest resistance to sulphonamide, Tetracycline and β-lactams were as 53.33, 46.66 and 13.33% respectively but no resistance with gentamycin and streptomycin. Here, we concluded that humans and animals both were refractory to the various groups of antibiotics. This study will help in making the strategy for prevention or reduction of resistance in public


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