Clostridium difficile in bee products: assessing the spread of the bacterium

Abstract

The vicinity of small apiaries to the farms makes honey and bee pollen prone to the contamination with clostridial spores. The possible presence of Clostridium difficile (C. difficile) spores in bee products may pose a risk especially to elderly who perceive them as natural remedies in health problems including functional bowel abnormalities. The aim of the study was to evaluate the prevalence of C. difficile spores in 120 samples of honey and 44 samples of bee pollen harvested in Northeastern Europe. All incubation procedures were performed in anaerobic conditions. The 10 g samples were subsequently pre-enriched in Cooked Meat Medium (CMM) and Brain Heart Infusion-supplement (BHIS) broths. Sporulated forms were seeded on supplemented C. difficile blood agar. Rapid immunoenzymatic tests targeted at glutamate dehydrogenase (GDH) detection and polymerase chain reaction (PCR) targeted at tpi gene detection were also performed. Based on microbiological culture 32 (20%) out of 164 samples were selected for culture on blood agar. The growth of ground-glass colonies was noted towards 13 (8%) samples. The presence of C. difficile was not confirmed by immunoenzymatic rapid tests towards any sample selected. Neither PCR assay targeted to tpi gene showed positive samples. This is the first report reviewing the possibility of native to Europe Apis mellifera (A. mellifera) bee products contamination with C. difficile. The samples of A. mellifera bee products produced in small apiaries in Northeastern Europe did not show the presence of C. difficile spores.