{"title":"氨苄西林亚抑制浓度加重多重耐药大肠杆菌O104:H4的毒力。","authors":"Yaraymi Ortiz, Vianey Lechuga, Carolina Ortiz, Eduardo Palomino, Eduardo Franco, Norma Heredia, Santos García","doi":"10.1016/j.resmic.2025.104266","DOIUrl":null,"url":null,"abstract":"<p><p>Little is known about how subinhibitory concentrations of antibiotics to which bacteria are resistant affect bacterial virulence. In this study, the effect of subinhibitory concentrations of ampicillin on the virulence of E. coli O104:H4 was analyzed. Bacteria were pre-exposed to 0.1, 0.3, or 0.5 mg/mL of ampicillin in LB media and incubated for 4 h at 37 °C. Transformation capacity (using plasmids and PCR-amplified DNA sequences), swarming motility, biofilm production, curli formation, and virulence gene expression were determined. Ampicillin increased the transformation of E. coli O104:H4, with the highest number of transformants (>10<sup>4</sup> CFU/ng DNA; p ≤ 0.05) detected after exposure to DNA sequences of spectinomycin. In addition, bacteria pre-treated with 0.5 mg/mL of ampicillin exhibited higher swarming motility (7.6 cm, vs 6.0 cm for control; p ≤ 0.05) and biofilm production (up to 1.9-fold; p ≤ 0.05) when subsequently exposed to 0.1 and 0.3 mg/mL of antibiotic compared with the control. Also, significant overexpression of the virulence-related genes flhC (≤16.1-fold), fliA (≤22.1-fold), csgA (≤3.6-fold), csgD (≤9.1-fold), stx2a (≤32.2-fold), and the antibiotic resistance gene blaTEM-1 (≤5.5-fold) was observed. In conclusion, ampicillin-resistant E. coli O104:H4 increased the expression of its virulence factors when exposed to most subinhibitory concentrations of ampicillin analyzed in this study.</p>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":" ","pages":"104266"},"PeriodicalIF":2.5000,"publicationDate":"2025-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Exacerbation of virulence of multi-drug resistant Escherichia coli O104:H4 by subinhibitory concentrations of ampicillin.\",\"authors\":\"Yaraymi Ortiz, Vianey Lechuga, Carolina Ortiz, Eduardo Palomino, Eduardo Franco, Norma Heredia, Santos García\",\"doi\":\"10.1016/j.resmic.2025.104266\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><p>Little is known about how subinhibitory concentrations of antibiotics to which bacteria are resistant affect bacterial virulence. In this study, the effect of subinhibitory concentrations of ampicillin on the virulence of E. coli O104:H4 was analyzed. Bacteria were pre-exposed to 0.1, 0.3, or 0.5 mg/mL of ampicillin in LB media and incubated for 4 h at 37 °C. Transformation capacity (using plasmids and PCR-amplified DNA sequences), swarming motility, biofilm production, curli formation, and virulence gene expression were determined. Ampicillin increased the transformation of E. coli O104:H4, with the highest number of transformants (>10<sup>4</sup> CFU/ng DNA; p ≤ 0.05) detected after exposure to DNA sequences of spectinomycin. In addition, bacteria pre-treated with 0.5 mg/mL of ampicillin exhibited higher swarming motility (7.6 cm, vs 6.0 cm for control; p ≤ 0.05) and biofilm production (up to 1.9-fold; p ≤ 0.05) when subsequently exposed to 0.1 and 0.3 mg/mL of antibiotic compared with the control. Also, significant overexpression of the virulence-related genes flhC (≤16.1-fold), fliA (≤22.1-fold), csgA (≤3.6-fold), csgD (≤9.1-fold), stx2a (≤32.2-fold), and the antibiotic resistance gene blaTEM-1 (≤5.5-fold) was observed. In conclusion, ampicillin-resistant E. coli O104:H4 increased the expression of its virulence factors when exposed to most subinhibitory concentrations of ampicillin analyzed in this study.</p>\",\"PeriodicalId\":21098,\"journal\":{\"name\":\"Research in microbiology\",\"volume\":\" \",\"pages\":\"104266\"},\"PeriodicalIF\":2.5000,\"publicationDate\":\"2025-01-08\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Research in microbiology\",\"FirstCategoryId\":\"99\",\"ListUrlMain\":\"https://doi.org/10.1016/j.resmic.2025.104266\",\"RegionNum\":4,\"RegionCategory\":\"生物学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"MICROBIOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Research in microbiology","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1016/j.resmic.2025.104266","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MICROBIOLOGY","Score":null,"Total":0}
Exacerbation of virulence of multi-drug resistant Escherichia coli O104:H4 by subinhibitory concentrations of ampicillin.
Little is known about how subinhibitory concentrations of antibiotics to which bacteria are resistant affect bacterial virulence. In this study, the effect of subinhibitory concentrations of ampicillin on the virulence of E. coli O104:H4 was analyzed. Bacteria were pre-exposed to 0.1, 0.3, or 0.5 mg/mL of ampicillin in LB media and incubated for 4 h at 37 °C. Transformation capacity (using plasmids and PCR-amplified DNA sequences), swarming motility, biofilm production, curli formation, and virulence gene expression were determined. Ampicillin increased the transformation of E. coli O104:H4, with the highest number of transformants (>104 CFU/ng DNA; p ≤ 0.05) detected after exposure to DNA sequences of spectinomycin. In addition, bacteria pre-treated with 0.5 mg/mL of ampicillin exhibited higher swarming motility (7.6 cm, vs 6.0 cm for control; p ≤ 0.05) and biofilm production (up to 1.9-fold; p ≤ 0.05) when subsequently exposed to 0.1 and 0.3 mg/mL of antibiotic compared with the control. Also, significant overexpression of the virulence-related genes flhC (≤16.1-fold), fliA (≤22.1-fold), csgA (≤3.6-fold), csgD (≤9.1-fold), stx2a (≤32.2-fold), and the antibiotic resistance gene blaTEM-1 (≤5.5-fold) was observed. In conclusion, ampicillin-resistant E. coli O104:H4 increased the expression of its virulence factors when exposed to most subinhibitory concentrations of ampicillin analyzed in this study.
期刊介绍：
Research in Microbiology is the direct descendant of the original Pasteur periodical entitled Annales de l''Institut Pasteur, created in 1887 by Emile Duclaux under the patronage of Louis Pasteur. The Editorial Committee included Chamberland, Grancher, Nocard, Roux and Straus, and the first issue began with Louis Pasteur''s "Lettre sur la Rage" which clearly defines the spirit of the journal:"You have informed me, my dear Duclaux, that you intend to start a monthly collection of articles entitled "Annales de l''Institut Pasteur". You will be rendering a service that will be appreciated by the ever increasing number of young scientists who are attracted to microbiological studies. In your Annales, our laboratory research will of course occupy a central position, but the work from outside groups that you intend to publish will be a source of competitive stimulation for all of us."That first volume included 53 articles as well as critical reviews and book reviews. From that time on, the Annales appeared regularly every month, without interruption, even during the two world wars. Although the journal has undergone many changes over the past 100 years (in the title, the format, the language) reflecting the evolution in scientific publishing, it has consistently maintained the Pasteur tradition by publishing original reports on all aspects of microbiology.
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