Abstract:
Objective: To determine important errors in initial Gram staining of clinical specimens and evaluate the types of Gram-stain
errors.
Study Design: Cross-sectional study.
Place and Duration of Study: Microbiology Department, Armed Forces Institute of Pathology, Rawalpindi Pakistan, from Aug
2018 to Feb 2019.
Methodology: Gram staining and culture inoculation of all specimens were performed per recommended guidelines. The
Gram stain results on day-0 were compared with the results of the culture on day-2. There was no discrepancy if similar
organisms were obtained on culture as on Gram stain. Nevertheless, if the Gram stain and culture results were not similar, it
was termed a discrepancy. The consultant microbiologist reviewed all discrepant slides, and if not resolved, possible causes of
error were sought, and the results documented.
Results: Of the total 300 clinical specimens, errors were observed in the initial gram staining of 29 specimens (9.7%), whereas
271(90.3%) specimens were error-free. Upon evaluating these 29 errors, 11(38.0%) were observer errors which were resolved
when reviewed by a consultant microbiologist. 14(48.0%) were technical errors, and 4(14.0%) results were discrepant due to
the presence of anaerobic organisms, missed on initial aerobic cultures.
Conclusion: The frequency of Gram stain errors in our study (9.7%) is not very high; nevertheless, it can have severe
consequences in critical samples from seriously ill patients if wrong empirical antimicrobial treatment is begun based on a
wrong initial Gram stain result.
