Tn916-dependent conjugal transfer of PC194 and PUB110 from Bacillus subtilis into Bacillus thuringiensis subsp. israelensis

Naglich, Joseph G.; Andrews, Robert E.

doi:10.1016/0147-619x(88)90014-5

Cited by 62 publications

(46 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our observation that a chromosome-borne Tn916 can mobilize a nonconjugative plasmid (e.g., pAM401 or pVA749) at a low frequency (i.e., less than 2% cotransfer) is consistent with that of Naglich and Andrews (23), who reported that a Tn916-dependent transfer of nonconjugative plasmids between Bacillus subtilis and Bacillus thuringiensis also occurred at a relatively low frequency. However, these observations differ somewhat from those of Guffanti et al (16), who recently reported a relatively high frequency of plasmid mobilization between B. subtilis and Bacillus firmus by the conjugative transposon Tn925.…”

Section: Discussionsupporting

confidence: 79%

Conjugative transfer of Tn916 in Enterococcus faecalis: trans activation of homologous transposons

Flannagan

Clewell

1991

J Bacteriol

View full text Add to dashboard Cite

tet. Experiments showed that the presence of one element (e.g., Tn916AE) in a recipient cell did not prevent the uptake of the other (e.g., Tn916) (7, 24), indicating an absence of negatively acting factors relating to entry exclusion or incompatibility. The presence of a transposon on the recipient chromosome also failed to prevent the zygotically induced excision-insertion that occurs at a high frequency when Tn916 enters passively on a conjugative plasmid (7). The data argue against the presence of a strong, trans-acting negative regulator being produced by an established element.In the present study we focus on the interaction that occurs between Tn916 and Tn9J6AE when they reside together in a donor cell. Evidence is presented showing that the transfer of one element results in a high-frequency trans activation of the other. Comobilization of resident plasmids was also detected, but at frequencies much lower than that involving the transposon. MATERIALS AND METHODSBacterial strains, plasmids, and media. The bacterial strains and plasmids used in this study are listed in Tables 1 and 2, respectively. Cultures of E. faecalis were grown in Todd-Hewitt broth (THB; Difco) at 37°C. Escherichia coli cultures were grown at 37°C in LB medium (11) for preparation of competent cells and in THB for plasmid isolation. Antibiotics, when present, were used in the following concentrations except as noted: tetracycline, 10 ,ig/ml (to maintain pAM420 in E. coli, a concentration of 60 p.g/ml was used); erythromycin, 10 ,ug/ml; chloramphenicol, 25 ,ug/ml; fusidic acid, 25 p.g/ml; streptomycin, 1,000 jig/ml; spectinomycin, 500 ,ug/ml; rifampin, 25 ,ug/ml. Rifampin was from Calbiochem, whereas all other antibiotics were from Sigma.DNA analyses. Chromosomal DNA was prepared by a standard protocol (35). Plasmid DNA was purified by an alkaline lysis procedure modified from that of Ish-Horowicz 7136 JOURNAL

show abstract

Section: Discussionsupporting

confidence: 79%

Conjugative transfer of Tn916 in Enterococcus faecalis: trans activation of homologous transposons

Flannagan

Clewell

1991

J Bacteriol

View full text Add to dashboard Cite

show abstract

“…In cis, the transposon provides the proteins needed for transfer (257). The Tn916 family can mobilize plasmids in trans (48,183,297). Low levels of tetracycline increase the transfer of these genes and also increase the ability of the bacterial host to spread antibiotic resistance genes to other isolates, species, and genera (48,69,297).…”

Section: Distribution and Mobility Of Tet Genesmentioning

confidence: 99%

Tetracycline Antibiotics: Mode of Action, Applications, Molecular Biology, and Epidemiology of Bacterial Resistance

Chopra

Roberts

2001

Microbiol Mol Biol Rev

3,540

2,643

View full text Add to dashboard Cite

Tetracyclines were discovered in the 1940s and exhibited activity against a wide range of microorganisms including gram-positive and gram-negative bacteria, chlamydiae, mycoplasmas, rickettsiae, and protozoan parasites. They are inexpensive antibiotics, which have been used extensively in the prophlylaxis and therapy of human and animal infections and also at subtherapeutic levels in animal feed as growth promoters. The first tetracycline-resistant bacterium, Shigella dysenteriae, was isolated in 1953. Tetracycline resistance now occurs in an increasing number of pathogenic, opportunistic, and commensal bacteria. The presence of tetracycline-resistant pathogens limits the use of these agents in treatment of disease. Tetracycline resistance is often due to the acquisition of new genes, which code for energy-dependent efflux of tetracyclines or for a protein that protects bacterial ribosomes from the action of tetracyclines. Many of these genes are associated with mobile plasmids or transposons and can be distinguished from each other using molecular methods including DNA-DNA hybridization with oligonucleotide probes and DNA sequencing. A limited number of bacteria acquire resistance by mutations, which alter the permeability of the outer membrane porins and/or lipopolysaccharides in the outer membrane, change the regulation of innate efflux systems, or alter the 16S rRNA. New tetracycline derivatives are being examined, although their role in treatment is not clear. Changing the use of tetracyclines in human and animal health as well as in food production is needed if we are to continue to use this class of broad-spectrum antimicrobials through the present century

show abstract

“…Small tet(K) or tet(L)-carrying plasmids are not self-transmissible but can be transmi�ed into the recipient cells by the conjugation by means of conjugative plasmids or conjugative transposons co-resident in the same cell (Naglich and Andrews, 1988). These provide their conjugative apparatus and mobilize small plasmids either in trans or in cis.…”

Section: Active Efflux Determinants Of Grampositive Bacteriamentioning

confidence: 99%

Tetracyclines in veterinary medicine and bacterial resistance to them

Michalova¹,

PNovotna²,

Schlegelová³

2004

Vet. Med.

117

View full text Add to dashboard Cite

Since their discovery in 1945, tetracyclines have been used extensively in the therapy and prophylaxis of infectious diseases and as growth promoters. These wide applications have led to the equally fast spread of tetracycline resistant strains of gram-positive and gram-negative bacterial genera, including strains belonging to pathogenic as well as nonpathogenic species. Nonpathogenic bacteria could act as a reservoir of resistance determinants, which can be disseminated by horizontal transfer into pathogens. More than thirty different tetracycline resistance genes have been characterized. They encode two major mechanisms of resistance: 1 -active efflux of the antibiotic, and 2 -protection of ribosomes. Further mechanisms of tetracycline resistance include enzymatic inactivation of antibiotic, permeability barriers, mutations or multidrug transporter systems. Effective horizontal spread is favoured by the location of tetracycline resistance genes on mobile genetic elements such as plasmids and transposons. Their exchange, enhanced by the use of tetracyclines, is observed between bacteria of the same or different species and genera as well. Thus, questions of reevaluating and global reducing of tetracyclines in human and animal healthcare and food production are extensively discussed.

show abstract

Tn916-dependent conjugal transfer of PC194 and PUB110 from Bacillus subtilis into Bacillus thuringiensis subsp. israelensis

Cited by 62 publications

References 31 publications

Conjugative transfer of Tn916 in Enterococcus faecalis: trans activation of homologous transposons

Conjugative transfer of Tn916 in Enterococcus faecalis: trans activation of homologous transposons

Tetracycline Antibiotics: Mode of Action, Applications, Molecular Biology, and Epidemiology of Bacterial Resistance

Tetracyclines in veterinary medicine and bacterial resistance to them

Contact Info

Product

Resources

About