{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2023,11,8]],"date-time":"2023-11-08T20:28:07Z","timestamp":1699475287963},"reference-count":20,"publisher":"Hindawi Limited","issue":"2","license":[{"start":{"date-parts":[[2009,4,14]],"date-time":"2009-04-14T00:00:00Z","timestamp":1239667200000},"content-version":"unspecified","delay-in-days":14805,"URL":"https:\/\/www.cambridge.org\/core\/terms"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Genet. Res."],"published-print":{"date-parts":[[1968,10]]},"abstract":"<jats:p>We have previously described strains of<jats:italic>Escherichia coli<\/jats:italic>K12 resistant to D, L-ampicillin concentrations of 50 \u03bcg\/ml (Eriksson-Grennberg<jats:italic>et al.<\/jats:italic>1965; Boman<jats:italic>et al.<\/jats:italic>1967). Such strains were assumed to be double mutants carrying the genes<jats:italic>ampA<\/jats:italic>and<jats:italic>ampB<\/jats:italic>. We here describe genetic steps which produce strains carrying only the<jats:italic>ampB<\/jats:italic>gene. Determinations of resistance showed that<jats:italic>ampA<\/jats:italic>increased the resistance provided by<jats:italic>ampA<\/jats:italic><jats:sup>+<\/jats:sup>by a factor of 10\u201315.<jats:italic>AmpB<\/jats:italic>increased the resistance of both<jats:italic>ampA<\/jats:italic>and<jats:italic>ampA<\/jats:italic><jats:sup>+<\/jats:sup>by a factor of 2.<\/jats:p><jats:p>R-factors were introduced into two sets of strains with all combinations of<jats:italic>ampA<\/jats:italic>,<jats:italic>ampB<\/jats:italic>and their wild type alleles.<jats:italic>AmpA<\/jats:italic>and the R-factors gave additive effects on resistance, while<jats:italic>ampB<\/jats:italic>doubled the ampicillin resistance mediated by<jats:italic>ampA<\/jats:italic>as well as by the R-factors.<jats:italic>AmpB<\/jats:italic>also enhanced the chloramphenicol resistance of R-factor and of the wild type chromosomal genes. It is suggested that<jats:italic>ampB<\/jats:italic>resembles the modifying genes previously described and that R-factors can be useful for the identification of such genes.<\/jats:p>","DOI":"10.1017\/s0016672300011770","type":"journal-article","created":{"date-parts":[[2009,9,17]],"date-time":"2009-09-17T07:55:17Z","timestamp":1253174117000},"page":"157-168","source":"Crossref","is-referenced-by-count":42,"title":["Resistance of<i>Escherichia coli<\/i>to penicillins: III. AmpB, a locus affecting episomally and chromosomally mediated resistance to ampicillin and chloramphenicol"],"prefix":"10.1155","volume":"12","author":[{"given":"Kurt","family":"Nordstr\u00f6m","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kerstin G.","family":"Eriksson-Grennberg","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hans G.","family":"Boman","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"98","published-online":{"date-parts":[[2009,4,14]]},"reference":[{"key":"S0016672300011770_ref014","doi-asserted-by":"publisher","DOI":"10.1017\/S0016672300009538"},{"key":"S0016672300011770_ref001","doi-asserted-by":"publisher","DOI":"10.1017\/S0016672300010478"},{"key":"S0016672300011770_ref015","unstructured":"Nordstr\u00f6m K. & Burman L. G. (1968). Resistance of Escherichia coli to penicillins. VI. AmpB mediated sensitivity to osmotic shock and to cycloserine. In preparation."},{"key":"S0016672300011770_ref002","doi-asserted-by":"crossref","first-page":"293","DOI":"10.1128\/JB.62.3.293-300.1951","article-title":"Studies on lysogenesis. I. The mode of phage liberation by lysogenic Escherichia coli","volume":"62","author":"Bertani","year":"1951","journal-title":"J. Bact."},{"key":"S0016672300011770_ref007","doi-asserted-by":"publisher","DOI":"10.1093\/oxfordjournals.bmb.a070405"},{"key":"S0016672300011770_ref017","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.47.12.2005"},{"key":"S0016672300011770_ref020","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1016\/S0021-9258(18)65874-0","article-title":"Acetylornithinase of Escherichia coli: partial purification and some properties","volume":"218","author":"Vogel","year":"1956","journal-title":"J. Biol. Chem."},{"key":"S0016672300011770_ref006","doi-asserted-by":"publisher","DOI":"10.1017\/S0016672300011782"},{"key":"S0016672300011770_ref013","first-page":"43","article-title":"Purification of penicillinase from wild type and two ampicillin resistant mutants of Escherichia coli","volume":"106","author":"Lindstr\u00f6m","year":"1968","journal-title":"Biochem. J."},{"key":"S0016672300011770_ref003","doi-asserted-by":"publisher","DOI":"10.1099\/00221287-31-3-339"},{"key":"S0016672300011770_ref004","first-page":"366","volume-title":"Regulation of Nucleic Acid and Protein Biosynthesis","author":"Boman","year":"1967"},{"key":"S0016672300011770_ref009","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1128\/JB.90.1.54-62.1965","article-title":"Resistance of Escherichia coli to penicillins. I. Genetic study of some ampicillin-resistant mutants","volume":"90","author":"Eriksson-Grennberg","year":"1965","journal-title":"J. Bact."},{"key":"S0016672300011770_ref005","first-page":"106","article-title":"Two types of chromosomal genes for ampicillin resistance and their effect on R-factor mediated resistance in Escherichia coli","author":"Boman","year":"1968","journal-title":"Biochem. J."},{"key":"S0016672300011770_ref008","doi-asserted-by":"publisher","DOI":"10.1042\/bj0980204"},{"key":"S0016672300011770_ref010","doi-asserted-by":"publisher","DOI":"10.1017\/S0016672300011769"},{"key":"S0016672300011770_ref011","doi-asserted-by":"publisher","DOI":"10.1016\/0042-6822(59)90125-4"},{"key":"S0016672300011770_ref012","doi-asserted-by":"publisher","DOI":"10.1101\/SQB.1951.016.01.032"},{"key":"S0016672300011770_ref016","doi-asserted-by":"publisher","DOI":"10.1017\/S0016672300009708"},{"key":"S0016672300011770_ref018","doi-asserted-by":"crossref","first-page":"332","DOI":"10.1128\/br.31.4.332-353.1967","article-title":"Revised linkage map of Escherichia coli K-12","volume":"31","author":"Taylor","year":"1967","journal-title":"Bact. Rev."},{"key":"S0016672300011770_ref019","doi-asserted-by":"crossref","first-page":"87","DOI":"10.1128\/br.27.1.87-115.1963","article-title":"Infective heredity of multiple drug resistance in bacteria","volume":"27","author":"Watanabe","year":"1963","journal-title":"Bact. Rev."}],"container-title":["Genetical Research"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.cambridge.org\/core\/services\/aop-cambridge-core\/content\/view\/S0016672300011770","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,10,10]],"date-time":"2021-10-10T22:53:11Z","timestamp":1633906391000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.cambridge.org\/core\/product\/identifier\/S0016672300011770\/type\/journal_article"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1968,10]]},"references-count":20,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1968,10]]}},"alternative-id":["S0016672300011770"],"URL":"https:\/\/doi.org\/10.1017\/s0016672300011770","relation":{},"ISSN":["0016-6723","1469-5073"],"issn-type":[{"value":"0016-6723","type":"print"},{"value":"1469-5073","type":"electronic"}],"subject":[],"published":{"date-parts":[[1968,10]]}}}