Comparison of the Quality of Gram Stain Prepared Using Different Swab Transport Systems

Gram stain slide quality was assessed across five different swab transport systems using control strains of Gram-positive and Gram-negative bacteria to determine the impact of transport format on microscopic interpretation. Dry swab preparations produced the clearest slides, with minimal background interference and well-preserved bacterial morphology. In contrast, liquid and gel-based systems introduced varying degrees of background artefacts, including structures that could be misinterpreted as Gram-negative cocci. These findings demonstrate that transport medium composition can significantly influence Gram stain readability and the reliability of early presumptive diagnostic assessment.