Value of CAMP trial in identification of Streptococcus agalactiae and ex-ploration of mechanism of negative results
10.3969/j.issn.1000-4718.2024.12.019
- VernacularTitle:CAMP试验在无乳链球菌鉴定中的价值及其阴性结果产生机制的探讨
- Author:
Mo LI
1
;
Pinghua QU
1
;
Yanjiao ZHANG
1
;
Xuan ZHANG
1
Author Information
1. 广州中医药大学第二附属医院检验医学部,广东 广州 510006
- Publication Type:Journal Article
- Keywords:
CAMP test;
Streptococcus agalactiae;
16S rDNA gene sequencing;
cfb gene
- From:
Chinese Journal of Pathophysiology
2024;40(12):2343-2350
- CountryChina
- Language:Chinese
-
Abstract:
AIM:This study aims to investigate the utility of the Christie-Atkinson-Munch-Peterson(CAMP)test in identifying Streptococcus agalactiae and to assess the sensitivity of positive CAMP test results for this identification.We also identified and analyzed Streptococcus agalactiae isolates that exhibited negative CAMP test results and conducted a preliminary study on the possible mechanisms behind these occurrences.METHODS:Streptococcus agalactiae isolates were collected from the University Town Branch of Guangdong Provincial Hospital of Traditional Chinese Medicine be-tween January 2018 and January 2023.Isolates identified as Streptococcus agalactiae using an automated rapid microbial mass spectrometry detection system underwent the CAMP test.CAMP-negative strains were screened,and the presence of the cfb gene was assessed.We also conducted a statistical analysis of the clinical sources of the samples and the drug sensi-tivity test results for Streptococcus agalactiae.RESULTS:Among 112 Streptococcus agalactiae strains,two CAMP-nega-tive strains were identified,which were confirmed as Streptococcus agalactiae through 16S rDNA sequencing and showed negative detection of the cfb gene.The clinical sample sources for the 112 strains were as follows:midstream urine(34.82%),semen(34.82%),cervical swab(8.04%),secretion(4.46%),urethral swab(4.46%),venous blood(3.57%),pus(3.57%),sputum(1.79%),wound swab(1.79%),and unknown sources(1.79%).All Streptococcus agalactiae strains in our laboratory were found to be 100%sensitive to penicillin,linezolid,ampicillin,and vancomycin,while the resistance rate to levofloxacin was 24.44%.CONCLUSION:The positive results of the CAMP test demonstrate its potential for identifying Streptococcus agalactiae.The negative CAMP test results observed in the two strains could be at-tributed to the deletion of the cfb gene.The majority of Streptococcus agalactiae detected in clinical laboratory work were sourced from midstream urine and semen,indicating a potential association with urinary tract infections.However,the correlation with male reproductive diseases remains uncertain.
