Isolation, culture and identification of Clostridium in infant and young child food, biological samples and environmental samples

ObjectivesTo understand the Clostridium carriage levels of infant and young child food, biological samples and environment in Liaocheng, identify the collected samples with different methods and provide evidence for food hygiene supervision departments to take effective measures to reduce Clostridium contamination.

MethodsA total of 257 samples were used for anaerobic and micro aerobic cultures. Then the characteristics of growth, gram staining and morphological features of the isolates under ordinary microscope were analyzed. At last the isolates were identified by 16S rRNA gene cloning method.

ResultsA total of 97 strains of Clostridium were detected in 257 samples, the detection rate was 37.74%, including 38 strains of Clostridium bifermentans, 14 strains of Clostridium tertium, 12 strains of Clostridium sporogenes, 11 strains of Clostridium butyricum, 9 strains of Clostridium sordellii. The sources of 97 Clostridium strains were as follows: stool samples (50 strains), soil samples (28 strains), milk powder samples (6 strains), swabs of surface of table (6 strains), nipple (3 strains), water used for milk powder (2 strains), swabs of hands of milkmen (2 strains).

ConclusionThe carriage rate of Clostridium in infant and young child food, biological samples and environment was very high in Laiocheng. The detection rate of C. bifermentans was highest, followed by C. tertium, C. sporogenes and C. butyricum.