PubMed · 8469301
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J A Jacobs, J L Verhagen, J J Schrander, E E Stobberingh. 1993-03-27. [Pneumococci].. https://pubmed.ncbi.nlm.nih.gov/8469301/
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The resistance inhibitory activities of 54 odorant mixtures (essential oil) from 41 Korean aromatic herbs were tested against multi-drug resistant Staphylococcus aureus SA2, which has resistances to 10 usual antibiotics including chloramphenicol. As results, combinations of 28 kinds of samples from 21 herbs and chloramphenicol have resistance inhibitory activities in dose dependent manner.
For the examination of possible intermitochondrial interaction of human mitochondria from different cells, cybrids were constructed by introducing HeLa mitochondria into cells with respiration-deficient (rho-) mitochondria. Respiration deficiency was due to the predominance of mutant mtDNA with a 5,196-base pair deletion including five tRNA genes (DeltamtDNA5196). The HeLa mtDNA and DeltamtDNA5196 encoded chloramphenicol-resistant (CAPr) and chloramphenicol-sensitive (CAPs) 16 S rRNA, respectively. The first evidence for the interaction was that polypeptides exclusively encoded by DeltamtDNA5196 were translated on the introduction of HeLa mitochondria, suggesting supplementation of the missing tRNAs by rho- mitochondria from HeLa mitochondria. Second, the exchange of mitochondrial rRNAs was observed; even in the presence of CAP, CAPs DeltamtDNA5196-specific polypeptides as well as those encoded by CAPr HeLa mtDNA were translated in the cybrids. These phenomena can be explained assuming that the translation in rho- mitochondria was restored by tRNAs and CAPr 16 S rRNA supplied from HeLa mitochondria, unambiguously indicating interorganellar interaction. These observations introduce a new concept of the dynamics of the mitochondrial genetic system and help in understanding the relationship among mtDNA mutations and expression of human mitochondrial diseases and aging.
An excision reporter plasmid was constructed to characterize the intracellular mobility of Tn916 in various Gram-positive bacteria. The reporter component of this plasmid is a chloramphenicol-resistance gene which has been insertionally inactivated with the integrative vector pAT112 containing the attachment site of Tn916. Tn916-mediated excision of pAT112, to produce clones resistant to chloramphenicol, was detected in Enterococcus faecalis BM4110, Listeria monocytogenes L028-Str and Streptococcus gordonii BM120, but not in Lactococcus lactis MG1363-RF or in Streptococcus pneumoniae BM124, and always depended upon the ability of the bacterial host to generate circular forms of the transposon. The results suggest that (i) the excision event, although required, is not sufficient for conjugal transfer to occur and (ii) there is no linear relationship between the donor potential of E. faecalis strains and either the excision frequency of pAT112 or the copy number of Tn916 circular intermediates per cell in these hosts. Excision of pAT112 occurred mainly during the late exponential phase of growth of E. faecalis and L. monocytogenes and this recombination event was not stimulated by heat shock, salt and alcohol stresses or by the presence of tetracycline in the medium.