{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,11]],"date-time":"2025-11-11T13:26:36Z","timestamp":1762867596228},"reference-count":18,"publisher":"American Society for Microbiology","issue":"11","license":[{"start":{"date-parts":[[1998,11,1]],"date-time":"1998-11-01T00:00:00Z","timestamp":909878400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.asm.org\/non-commercial-tdm-license"}],"content-domain":{"domain":["journals.asm.org"],"crossmark-restriction":true},"short-container-title":["Antimicrob Agents Chemother"],"published-print":{"date-parts":[[1998,11]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n          <jats:p>\n            Selection of resistance to amoxicillin (with or without clavulanate), cefaclor, cefuroxime, and azithromycin among six penicillin G- and azithromycin-susceptible pneumococcal strains and among four strains with intermediate penicillin sensitivities (azithromycin MICs, 0.125 to 4 \u03bcg\/ml) was studied by performing 50 sequential subcultures in medium with sub-MICs of these antimicrobial agents. For only one of the six penicillin-susceptible strains did subculturing in medium with amoxicillin (with or without clavulanate) lead to an increased MIC, with the MIC rising from 0.008 to 0.125 \u03bcg\/ml. Five of the six penicillin-susceptible strains showed increased azithromycin MICs (0.5 to &gt;256.0 \u03bcg\/ml) after 17 to 45 subcultures. Subculturing in medium with cefaclor did not affect the cefaclor MICs of three strains but and led to increased cefaclor MICs (from 0.5 to 2.0 to 4.0 \u03bcg\/ml) for three of the six strains, with MICs of other \u03b2-lactams rising 1 to 3 twofold dilutions. Subculturing in cefuroxime led to increased cefuroxime MICs (from 0.03 to 0.06 \u03bcg\/ml to 0.125 to 0.5 \u03bcg\/ml) for all six strains without significantly altering the MICs of other \u03b2-lactams, except for one strain, which developed an increased cefaclor MIC. Subculturing in azithromycin did not affect \u03b2-lactam MICs. Subculturing of the four strains with decreased penicillin susceptibility in amoxicillin (with or without clavulanate) or cefuroxime did not select for \u03b2-lactam resistance. Subculturing of one strain in cefaclor led to an increase in MIC from 0.5 to 2.0 \u03bcg\/ml after 19 passages. In contrast to strains that were initially azithromycin susceptible, which required &gt;10 subcultures for resistance selection, three of four strains with azithromycin MICs of 0.125 to 4.0 \u03bcg\/ml showed increased MICs after 7 to 13 passages, with the MICs increasing to 16 to 32 \u03bcg\/ml. All azithromycin-resistant strains were clarithromycin resistant. With the exception of strains that contained\n            <jats:italic>mefE<\/jats:italic>\n            at the onset, no strains that developed resistance to azithromycin contained\n            <jats:italic>ermB<\/jats:italic>\n            or\n            <jats:italic>mefE<\/jats:italic>\n            , genes that have been found in macrolide-resistant pneumococci obtained from clinic patients.\n          <\/jats:p>","DOI":"10.1128\/aac.42.11.2914","type":"journal-article","created":{"date-parts":[[2018,10,9]],"date-time":"2018-10-09T00:29:45Z","timestamp":1539044985000},"page":"2914-2918","update-policy":"http:\/\/dx.doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":54,"title":["In Vitro Selection of Resistance to Four \u03b2-Lactams and Azithromycin in\n            <i>Streptococcus pneumoniae<\/i>"],"prefix":"10.1128","volume":"42","author":[{"given":"Glenn A.","family":"Pankuch","sequence":"first","affiliation":[{"name":"<!--label omitted: 1-->Department of Pathology (Clinical Microbiology), Hershey Medical Center, Hershey, Pennsylvania 17033,1 and"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shane A.","family":"Jueneman","sequence":"additional","affiliation":[{"name":"<!--label omitted: 1-->Department of Pathology (Clinical Microbiology), Hershey Medical Center, Hershey, Pennsylvania 17033,1 and"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Todd A.","family":"Davies","sequence":"additional","affiliation":[{"name":"<!--label omitted: 1-->Department of Pathology (Clinical Microbiology), Hershey Medical Center, Hershey, Pennsylvania 17033,1 and"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Michael R.","family":"Jacobs","sequence":"additional","affiliation":[{"name":"<!--label omitted: 2-->Department of Pathology (Clinical Microbiology), Case Western Reserve University, Cleveland, Ohio 441062"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Peter C.","family":"Appelbaum","sequence":"additional","affiliation":[{"name":"<!--label omitted: 1-->Department of Pathology (Clinical Microbiology), Hershey Medical Center, Hershey, Pennsylvania 17033,1 and"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"235","reference":[{"key":"e_1_3_2_2_2","doi-asserted-by":"publisher","DOI":"10.1093\/clinids\/15.1.77"},{"key":"e_1_3_2_3_2","doi-asserted-by":"crossref","unstructured":"Baquero F. 1996. Trends in antibiotic resistance of respiratory pathogens: an analysis and commentary on a collaborative surveillance study. J. Antimicrob. Chemother. 38 (Suppl. A):117\u2013132.","DOI":"10.1093\/jac\/38.suppl_A.117"},{"key":"e_1_3_2_4_2","unstructured":"Baquero F. and M. C. Negri. 1997. Strategies to minimise the development of antibiotic resistance. J. Chemother. 9 (Suppl. 3):29\u201337."},{"key":"e_1_3_2_5_2","doi-asserted-by":"publisher","DOI":"10.1001\/jama.1994.03510470035031"},{"key":"e_1_3_2_6_2","doi-asserted-by":"publisher","DOI":"10.1093\/jac\/36.2.417"},{"key":"e_1_3_2_7_2","unstructured":"Carsenti-Etesse\n              H.\n              Durant\n              J.\n              Roger\n              P. M.\n              Bensoussan\n              M.\n              Mancini\n              G.\n              Thabaut\n              A.\n              Dellamonica\n              P.\n          In vitro development of resistance of Streptococcus pneumoniae (SP) by spiral method or serial passages in sub-inhibitory (subMICs) concentrations of betalactams abstr. E11\n          Abstracts of the 35th Interscience Conference on Antimicrobial Agents and Chemotherapy.\n          1995\n          87\n          American Society for Microbiology\n          Washington D.C"},{"key":"e_1_3_2_8_2","unstructured":"Carsenti-Etesse\n              H.\n              Roger\n              P. M.\n              Mancini\n              G.\n              Thabaut\n              A.\n              Dellamonica\n              P.\n          In vitro development of resistance of Streptococcus pneumoniae (SP) by spiral method in sub inhibitory (subMICs) concentrations of betalactams and macrolides abstr. J13\n          Abstracts of the 36th Interscience Conference on Antimicrobial Agents and Chemotherapy.\n          1996\n          220\n          American Society for Microbiology\n          Washington D.C"},{"key":"e_1_3_2_9_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.40.5.1208"},{"key":"e_1_3_2_10_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.40.8.1950"},{"key":"e_1_3_2_11_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.41.1.129"},{"key":"e_1_3_2_12_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJM199408113310607"},{"key":"e_1_3_2_13_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0399-077X(05)80772-3"},{"key":"e_1_3_2_14_2","doi-asserted-by":"publisher","DOI":"10.1093\/clinids\/15.1.119"},{"key":"e_1_3_2_15_2","doi-asserted-by":"publisher","DOI":"10.1128\/jcm.35.1.298-301.1997"},{"key":"e_1_3_2_16_2","doi-asserted-by":"publisher","DOI":"10.1093\/infdis\/164.2.302"},{"key":"e_1_3_2_17_2","unstructured":"National Committee for Clinical Laboratory Standards\n          Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically. Publication no. M7-A4.\n          1997\n          National Committee for Clinical Laboratory Standards\n          Villanova Pa"},{"key":"e_1_3_2_18_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.40.11.2562"},{"key":"e_1_3_2_19_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.41.10.2251"}],"container-title":["Antimicrobial Agents and Chemotherapy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/AAC.42.11.2914","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/AAC.42.11.2914","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,2,21]],"date-time":"2022-02-21T15:42:50Z","timestamp":1645458170000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/AAC.42.11.2914"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1998,11]]},"references-count":18,"journal-issue":{"issue":"11","published-print":{"date-parts":[[1998,11]]}},"alternative-id":["10.1128\/AAC.42.11.2914"],"URL":"https:\/\/doi.org\/10.1128\/aac.42.11.2914","relation":{},"ISSN":["0066-4804","1098-6596"],"issn-type":[{"value":"0066-4804","type":"print"},{"value":"1098-6596","type":"electronic"}],"subject":[],"published":{"date-parts":[[1998,11]]},"assertion":[{"value":"1998-04-07","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"1998-08-17","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"1998-11-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}