Table 1.

Categorisation of bacterial growth for each tissue sample

Initial categorisation	Description	Final categorisation with positive PCR*	Final categorisation with negative PCR†
No growth	No growth, single colonies outside the streak or clinically irrelevant species (ie, Micrococcus spp).	No growth	No growth
Possible contamination	<5 single colonies on primary plate and no growth from enrichment broth	‘Possible significant growth’	‘No growth’
	No growth on primary plate but growth from enrichment broth	‘Possible significant growth’	‘No growth’
Significant growth	Growth on primary plate and from enrichment broth, or growth ≥5 single colonies on primary plate regardless of growth or not in enrichment broth	‘Significant growth’	‘Significant growth’

*PCR analysis (16S rDNA sequencing) positive for the same species as the cultivated possible contaminant. The sample may still be considered contamination, but we cannot rule out that the growth is significant.

†PCR analyses (16S rDNA sequencing) negative for the cultivated possible contaminant. The sample is considered a true ‘no growth’.