{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,24]],"date-time":"2026-08-24T15:37:13Z","timestamp":1787585833913,"version":"build-2736575974"},"reference-count":27,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2023,5,24]],"date-time":"2023-05-24T00:00:00Z","timestamp":1684886400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Microbiol."],"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>\n                      <jats:italic>Streptococcus agalactiae<\/jats:italic>\n                      can produce CAMP factor, which can promote the \u03b2-hemolysin activity of\n                      <jats:italic>Staphylococcus aureus<\/jats:italic>\n                      , forming an arrow-shaped hemolysis enhancement zone at the intersection of the two bacterial species on a blood agar plate. This characteristic feature of\n                      <jats:italic>Streptococcus agalactiae<\/jats:italic>\n                      has led to the widespread use of the CAMP test as an identification method.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      Vaginal\/rectal swabs, collected from women at 35\u201337 \u2009weeks of pregnancy, were first inoculated into a selective enrichment broth media, then subcultured onto GBS chromogenic agar and 5% sheep blood agar sequentially. The VITEK-2 automatic identification system and MALDI-TOF MS were initially employed for identification, followed by the CAMP test. CAMP-negative strains underwent 16S rDNA and\n                      <jats:italic>cfb<\/jats:italic>\n                      gene sequence analysis, as well as bacterial multilocus sequence typing.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      A total of 190 strains were isolated, with 15 identified as CAMP-negative. Further 16S rDNA gene sequence analysis confirmed that all 15 strains were\n                      <jats:italic>Streptococcus agalactiae<\/jats:italic>\n                      . The MLST typing assay revealed that these 15 strains were of the ST862 type. The\n                      <jats:italic>cfb<\/jats:italic>\n                      gene was amplified and electrophoresed, but no specific fragments were found, indicating that these strains lack the CAMP factor due to\n                      <jats:italic>cfb<\/jats:italic>\n                      gene deletion. Antibiotic susceptibility tests demonstrated no resistance to penicillin, ampicillin, vancomycin and linezolid among the GBS strains. However, there are significant differences in resistance rates to tetracycline.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>\n                      This study found that 7.9% of GBS strains isolated from the vagina\/rectum of pregnant women were CAMP-negative, suggesting that the CAMP test method or primers targeting the\n                      <jats:italic>cfb<\/jats:italic>\n                      gene should not be used as the sole presumptive test for GBS identification.\n                    <\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fmicb.2023.1189093","type":"journal-article","created":{"date-parts":[[2023,5,24]],"date-time":"2023-05-24T02:01:50Z","timestamp":1684893710000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":11,"title":["Analysis of molecular characteristics of CAMP-negative Streptococcus agalactiae strains"],"prefix":"10.3389","volume":"14","author":[{"given":"Jie","family":"Zhou","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Li","family":"Zhang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yang","family":"Zhang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hui","family":"Liu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kangli","family":"Xu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Baohu","family":"Zhang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tianyuan","family":"Feng","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shucai","family":"Yang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2023,5,24]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"838","DOI":"10.1128\/iai.23.3.838-844.1979","article-title":"Nature and mechanism of action of the CAMP protein of group B Streptococci","volume":"23","author":"Bernheimer","year":"1979","journal-title":"Infect. 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