In which situation might a false-positive CAMP test for group B streptococci occur?

A false-positive CAMP test for group B streptococci can occur in a candle jar or CO2 incubator due to the specific growth conditions that favor the development of other organisms that can produce similar hemolytic patterns. The CAMP test assesses the ability of certain bacteria, specifically Streptococcus agalactiae (group B strep), to enhance the hemolysis of Staphylococcus aureus. In a CO2-rich environment, the growth of other organisms, like certain Enterococcus species or other staphylococci, can lead to misleadingly positive results because these bacteria may also demonstrate hemolytic properties that can mimic those of group B strep.

On the other hand, incubating in ambient air typically does not create an environment conducive to such false positives. Incubation at 35°C or 37°C is standard for the growth of Streptococcus species but does not particularly contribute to false positives on its own unless accompanied by the wrong incubation atmosphere. Therefore, the specific conditions of a candle jar or CO2 incubator, which can foster the growth of various bacteria, are crucial to understanding the risk of false-positive results in the CAMP test.