Is a positive Christie-Atkinson-Munch-Peterson (CAMP) test sensitive enough for the identification of Streptococcus agalactiae?

Abstract

BackgroundFor a long time, the Christie-Atkinson-Munch-Peterson (CAMP) test has been a standard test for the identification of Streptococcus agalactiae, and a positive result for S.agalactiae has been considered sensitive enough.MethodsTo confirm whether a positive CAMP test is a requirement for the identification of S.agalactiae, five suspected CAMP-negative S.agalactiae isolates from two hospitals, confirmed as Gram-positive and catalase-negative streptococci, were verified by the CAMP test in three batches of plates from two manufacturers and identified by the Phoenix system, MALDI-TOF MS, the PCR assay and the 16S rDNA gene sequencing.ResultsAll five suspected strains were S.agalactiae, four of which were CAMP-negative and one of which was not S.agalactiae by the PCR assay.ConclusionsA positive CAMP test was lacking sensitivity for the identification of S.agalactiae, and the question of whether the cfb gene is worthy of targeting should be further studied.

Molecular diagnostic assays for the detection of common bacterial meningitis pathogens: A narrative review

“…The Christie-Atkinson-Munch-Peterson (CAMP) test has been the conventional culture-based test for identifying GBS and differentiates haemolytic versus non-haemolytic GBS. Notably, some GBS isolates are CAMP negative and lack cfb , indicating that further studies assessing the distribution of cfb are required [ 41 , 42 ]. Another assay employed a recombinase polymerase amplification (RPA) method to detect the cfb gene in vaginal swabs and this assay was sensitive and specific for GBS [43] .…”

False-positive detection of Group B Streptococcus (GBS) in chromogenic media due to presence of Enterococcus faecalis in High Vaginal Swabs

“…The copyright holder for this this version posted December 18, 2021. ; https://doi.org/10.1101/2021.12.17.21267936 doi: medRxiv preprint ease of interpretation and fast turnaround time following sample collection (Gao et al, 2021, Guo et al, 2019.…”

Usefulness Of Microbial Cytotoxins In The Diagnosis Of Selected Bacterial Infections

“…1). Następnie płytkę inkubuje się w warunkach tlenowych przez 18-24 godzin w temperaturze 37°C, a za pozytywny wynik uznaje się charakterystyczną strzałkę powstającą na styku posiewów S. agalactiae i S. aureus (reakcja synergistycznej hemolizy) [17,18,20,25].…”

“…Test CAMP jest jedną z podstawowych metod stosowanych do wstępnej identyfikacji S. agalactiae, którą przez długi czas uważano za niezawodną i wystarczająco czułą. Już na początku XXI wieku zaczęły pojawiać się doniesienia na temat CAMP-ujemnych paciorkowców grupy B, ale wtedy nie wzbudziły większego zainteresowania wśród badaczy i diagnostów [17,18,20]. Guo i współpracownicy (2019) zbadali czułość tej metody.…”

“…Wyniki te sugerują, że zarówno test CAMP, jak i wykrywanie genu cfb S. agalactiae powinno być uzupełniane innymi testami, m.in. biochemicznymi [18].…”