{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,2]],"date-time":"2026-09-02T09:20:16Z","timestamp":1788340816236,"version":"build-2803163510"},"reference-count":46,"publisher":"American Society for Microbiology","issue":"5","license":[{"start":{"date-parts":[[2024,5,8]],"date-time":"2024-05-08T00:00:00Z","timestamp":1715126400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2024,5,8]],"date-time":"2024-05-08T00:00:00Z","timestamp":1715126400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.asm.org\/non-commercial-tdm-license"}],"funder":[{"DOI":"10.13039\/100000060","name":"HHS | NIH | National Institute of Allergy and Infectious Diseases","doi-asserted-by":"crossref","award":["AI133289"],"award-info":[{"award-number":["AI133289"]}],"id":[{"id":"10.13039\/100000060","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["journals.asm.org"],"crossmark-restriction":true},"short-container-title":["mBio"],"published-print":{"date-parts":[[2024,5,8]]},"abstract":"ABSTRACT<\/jats:title>\n \n \n \n Penicillin-binding protein 5 (PBP5) of\n Enterococcus faecium<\/jats:italic>\n (\n Efm<\/jats:italic>\n ) is vital for ampicillin resistance (AMP-R). We previously designated three forms of PBP5, namely, PBP5-S in\n Efm<\/jats:italic>\n clade B strains [ampicillin susceptible (AMP-S)], PBP5-S\/R (AMP-S or R), and PBP5-R (AMP-R) in clade A strains. Here,\n pbp5<\/jats:italic>\n deletion resulted in a marked reduction in AMP minimum inhibitory concentrations (MICs) to 0.01\u20130.09 \u00b5g\/mL for clade B and 0.12\u20130.19 \u00b5g\/mL for clade A strains;\n in situ<\/jats:italic>\n complementation restored parental AMP MICs. Using D344SRF (lacking\n ftsW\/psr\/pbp5<\/jats:italic>\n ), constructs with\n ftsW<\/jats:italic>\n A<\/jats:sub>\n \/psr<\/jats:italic>\n A<\/jats:sub>\n (from a clade A1 strain) cloned upstream of\n pbp5-S<\/jats:italic>\n and\n pbp5-S\/R<\/jats:italic>\n alleles resulted in modest increases in MICs to 3\u20138 \u00b5g\/mL, while high MICs (\n ><\/jats:underline>\n 64 \u00b5g\/mL) were seen using\n pbp5<\/jats:italic>\n from A1 strains. Next, using\n ftsW \u00b1 psr<\/jats:italic>\n from clade B and clade A\/B and B\/A hybrid constructs, the presence of\n psr<\/jats:italic>\n B<\/jats:sub>\n , even alone or in\n trans<\/jats:italic>\n , resulted in much lower AMP MICs (3\u20138 \u00b5g\/mL) than when\n psr<\/jats:italic>\n A<\/jats:sub>\n was present (MICs\n ><\/jats:underline>\n 64 \u00b5g\/mL). qRT PCR showed relatively greater\n pbp5<\/jats:italic>\n expression (\n P<\/jats:italic>\n = 0.007) with\n pbp5<\/jats:italic>\n cloned downstream of clade A1\n ftsW\/psr<\/jats:italic>\n (MIC\n ><\/jats:underline>\n 128 \u00b5g\/mL) vs when cloned downstream of clade B\n ftsW\/psr<\/jats:italic>\n (MIC 4\u201316 \u00b5g\/mL), consistent with results in western blots. In conclusion, we report the effect of clade A vs B\n psr<\/jats:italic>\n on AMP MICs as well as the impact of\n pbp5<\/jats:italic>\n alleles from different clades. While previously, Psr was not thought to contribute to AMP MICs in\n Efm,<\/jats:italic>\n our results showed that the presence of\n \n psr\n B<\/jats:sub>\n <\/jats:italic>\n resulted in a major decrease in\n Efm<\/jats:italic>\n AMP MICs.\n <\/jats:p>\n <\/jats:sec>\n \n IMPORTANCE<\/jats:title>\n \n The findings of this study shed light on ampicillin resistance in\n Enterococcus faecium<\/jats:italic>\n clade A strains. They underscore the significance of alterations in the amino acid sequence of penicillin-binding protein 5 (PBP5) and the pivotal role of the psr region in PBP5 expression and ampicillin resistance. Notably, the presence of a full-length psrB leads to reduced PBP5 expression and lower minimum inhibitory concentrations (MICs) of ampicillin compared to the presence of a shorter psrA, regardless of the pbp5 allele involved. Additionally, clade B\n E. faecium<\/jats:italic>\n strains exhibit lower AMP MICs when both\n psr<\/jats:italic>\n alleles from clades A and B are present, although it is important to consider other distinctions between clade A and B strains that may contribute to this effect. It is intriguing to note that the divergence between clade A and clade B\n E. faecium<\/jats:italic>\n and the subsequent evolution of heightened AMP MICs in hospital-associated strains appear to coincide with changes in\n Pbp5<\/jats:italic>\n and\n psr<\/jats:italic>\n . These changes in\n psr<\/jats:italic>\n may have resulted in an inactive Psr, facilitating increased PBP5 expression and greater ampicillin resistance. These results raise the possibility that a mimicker of PsrB, if one could be designed, might be able to lower MICs of ampicillin-resistant\n E. faecium<\/jats:italic>\n , thus potentially resorting ampicillin to our therapeutic armamentarium for this species.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.1128\/mbio.00170-24","type":"journal-article","created":{"date-parts":[[2024,4,2]],"date-time":"2024-04-02T15:53:04Z","timestamp":1712073184000},"update-policy":"https:\/\/doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":14,"title":["Genomic context as well as sequence of both\n psr<\/i>\n and penicillin-binding protein 5 contributes to \u03b2-lactam resistance in\n Enterococcus faecium<\/i>"],"prefix":"10.1128","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3005-3982","authenticated-orcid":false,"given":"Kavindra V.","family":"Singh","sequence":"first","affiliation":[{"name":"Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1081-254X","authenticated-orcid":false,"given":"Jessica","family":"Galloway-Pe\u00f1a","sequence":"additional","affiliation":[{"name":"Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9639-9690","authenticated-orcid":true,"given":"Maria Camila","family":"Montealegre","sequence":"additional","affiliation":[{"name":"Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA"},{"name":"Department of Microbiology and Infectious Diseases, University of Texas Health Science Center, Houston, Texas, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xingxing","family":"Dong","sequence":"additional","affiliation":[{"name":"Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4461-6870","authenticated-orcid":false,"given":"Barbara E.","family":"Murray","sequence":"additional","affiliation":[{"name":"Division of Infectious Diseases, Department of Internal Medicine, University of Texas Health Science Center, Houston, Texas, USA"},{"name":"Department of Microbiology and Infectious Diseases, University of Texas Health Science Center, Houston, Texas, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"235","reference":[{"key":"e_1_3_3_2_2","doi-asserted-by":"publisher","DOI":"10.1086\/591861"},{"key":"e_1_3_3_3_2","doi-asserted-by":"publisher","DOI":"10.1017\/ice.2019.296"},{"key":"e_1_3_3_4_2","doi-asserted-by":"publisher","DOI":"10.2807\/1560-7917.ES.2021.26.45.2001628"},{"key":"e_1_3_3_5_2","doi-asserted-by":"publisher","DOI":"10.1093\/ofid\/ofy344"},{"key":"e_1_3_3_6_2","doi-asserted-by":"publisher","DOI":"10.1093\/jac\/dky188"},{"key":"e_1_3_3_7_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.drup.2018.10.002"},{"key":"e_1_3_3_8_2","doi-asserted-by":"publisher","DOI":"10.1111\/nyas.12948"},{"key":"e_1_3_3_9_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0030187"},{"key":"e_1_3_3_10_2","doi-asserted-by":"publisher","DOI":"10.1128\/mBio.00534-13"},{"key":"e_1_3_3_11_2","doi-asserted-by":"publisher","DOI":"10.1128\/mBio.00318-11"},{"key":"e_1_3_3_12_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.00099-11"},{"key":"e_1_3_3_13_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.45.5.1480-1486.2001"},{"key":"e_1_3_3_14_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.49.2.612-618.2005"},{"key":"e_1_3_3_15_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.03648-14"},{"key":"e_1_3_3_16_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.48.8.3028-3032.2004"},{"key":"e_1_3_3_17_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.02034-16"},{"key":"e_1_3_3_18_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.175.7.2046-2051.1993"},{"key":"e_1_3_3_19_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.01834-08"},{"key":"e_1_3_3_20_2","doi-asserted-by":"publisher","DOI":"10.1128\/AAC.45.9.2594-2597.2001"},{"key":"e_1_3_3_21_2","doi-asserted-by":"publisher","DOI":"10.1093\/infdis\/jiv597"},{"key":"e_1_3_3_22_2","doi-asserted-by":"publisher","DOI":"10.1186\/1471-2164-11-239"},{"key":"e_1_3_3_23_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.180.17.4426-4434.1998"},{"key":"e_1_3_3_24_2","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.72.1.334-345.2006"},{"key":"e_1_3_3_25_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pgen.1002804"},{"key":"e_1_3_3_26_2","volume-title":"Performance standards for antimicrobial susceptibility testingCLSI M100-ED 31","author":"CLSI","year":"2021","unstructured":"CLSI. 2021. Performance standards for antimicrobial susceptibility testing. 31st ed. CLSI M100-ED 31. Clinical and Laboratory Standards Institute, Annapolis Junction, MD.","edition":"31"},{"key":"e_1_3_3_27_2","doi-asserted-by":"publisher","DOI":"10.1111\/1574-6968.12146"},{"key":"e_1_3_3_28_2","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.00376-08"},{"key":"e_1_3_3_29_2","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.00885-15"},{"key":"e_1_3_3_30_2","doi-asserted-by":"publisher","DOI":"10.1128\/IAI.01911-14"},{"key":"e_1_3_3_31_2","doi-asserted-by":"publisher","DOI":"10.1128\/AEM.02665-07"},{"key":"e_1_3_3_32_2","doi-asserted-by":"publisher","DOI":"10.1111\/j.1574-6968.1997.tb12726.x"},{"key":"e_1_3_3_33_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1916037116"},{"key":"e_1_3_3_34_2","doi-asserted-by":"publisher","DOI":"10.1172\/JCI29021"},{"key":"e_1_3_3_35_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.ppat.1000716"},{"key":"e_1_3_3_36_2","doi-asserted-by":"publisher","DOI":"10.1038\/nrg3185"},{"key":"e_1_3_3_37_2","doi-asserted-by":"publisher","DOI":"10.1128\/MCB.19.3.1720"},{"key":"e_1_3_3_38_2","doi-asserted-by":"publisher","DOI":"10.1086\/515605"},{"key":"e_1_3_3_39_2","doi-asserted-by":"publisher","DOI":"10.1186\/s12866-016-0844-y"},{"key":"e_1_3_3_40_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.mib.2016.07.015"},{"key":"e_1_3_3_41_2","doi-asserted-by":"publisher","DOI":"10.1128\/jb.178.17.5272-5278.1996"},{"key":"e_1_3_3_42_2","doi-asserted-by":"publisher","DOI":"10.3390\/microorganisms10020217"},{"key":"e_1_3_3_43_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.vetmic.2021.109003"},{"key":"e_1_3_3_44_2","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2020.00557"},{"key":"e_1_3_3_45_2","doi-asserted-by":"publisher","DOI":"10.1371\/journal.ppat.1004891"},{"key":"e_1_3_3_46_2","doi-asserted-by":"publisher","DOI":"10.1128\/JB.00184-13"},{"key":"e_1_3_3_47_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.1300118110"}],"container-title":["mBio"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/mbio.00170-24","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/mbio.00170-24","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,5,8]],"date-time":"2024-05-08T09:02:14Z","timestamp":1715158934000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/mbio.00170-24"}},"subtitle":[],"editor":[{"given":"Paul M.","family":"Dunman","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2024,5,8]]},"references-count":46,"journal-issue":{"issue":"5","published-print":{"date-parts":[[2024,5,8]]}},"alternative-id":["10.1128\/mbio.00170-24"],"URL":"https:\/\/doi.org\/10.1128\/mbio.00170-24","relation":{},"ISSN":["2150-7511"],"issn-type":[{"value":"2150-7511","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,5,8]]},"assertion":[{"value":"2024-01-29","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-03-04","order":1,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2024-04-02","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e00170-24"}}