Abstract
In the brief communication “Coxiella burnetii in Infertile Dairy Cattle With Chronic Endometritis,” 1 the authors demonstrated the presence of C. burnetii within the endometrium by immunohistochemistry and PCR. The authors also presented results from double color immunofluorescence microscopy, claiming colocalization of C. burnetii and CD68, but positive signal is unconvincing in the images presented in Figure 3.
The possibility that autofluorescence is responsible for the claimed signal in these images is supported by identical colocalization of the purported immunofluorescent signal for C. burnetii and CD68 because such exact colocalization would not be expected given the variation in size and cellular location of each of these unique antigens. Moreover, the variably sized and punctate to globular appearance of the areas of supposed signal is characteristic of the autofluorescent material commonly observed within cells, particularly macrophages, in negative control slides.
The presence of immunofluorescent signal and autofluorescence cannot be evaluated and distinguished without positive and negative control slides. The article does not indicate that positive or negative controls were employed, nor were any data presented on such findings. It is essential to convey how the specificity of antibody binding is confirmed, particularly in a novel assay, with images and/or descriptions of the results from individual positive and negative control slides. It is also important to report how the immunofluorescent signals of interest are verified and distinguished from autofluorescence, including the computer software used to identify the immunofluorescent signal and the methods used to generate and interpret the resultant colocalization image.
As authors, we should strive to include an informative description and justification of scientific methods in a publication such that the reader can fully assess and foster confidence in the work performed.
Footnotes
Declaration of Conflicting Interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
The author(s) received no financial support for the research, authorship, and/or publication of this article.
