Molecular characterization of netB and tpeL virulence factors and antimicrobial resistance genes of Clostridium perfringens isolated from herbs and spices.

Abstract

The present study aimed to determine some virulence-associated genes and antimicrobial multidrug resistance of Clostridium perfringens recovered from herbs and spices widely distributed in the Egyptian market. C. perfringens virulence and resistance factors were determined using PCR targeting the netB, tpeL, ermB, bla and tetK genes. Thirty three out of 392 samples (8.42%) from herbs and spices submitted to our laboratory for bacteriological screening were positive for presence C. perfringens. PCR results for the tpeL gene in isolated C. perfringens revealed 9 out of 33 (27.3 %) of isolates, while netB was not detected. The isolates were resistant to Clindamycin, Vancomycin, tetracycline, and erythromycin with inhibition zones of 6.28 ± 0.63, 8.78 ± 0.41, 9.63 ± 0.63, and 9.84 ± 0.66 mm, respectively. The genes mentioned above were selected to correspond to the ineffective antimicrobials; ermB for erythromycin, tetK for tetracycline, and bla for the remainder. PCR results for antibacterial resistant genes in isolated C. perfringens revealed their presence. From 33 isolates, bla gene was detected in 21 (63.4 %), tetK in 13 (39.4 %) and ermB in only one isolate (3.03 %). Sequencing analysis was done for the bla gene as an example for the detected genes as detected at the highest incidence (63.4%). No cross-relationship was detected upon comparing incidence data of both studied virulence genes and those of antimicrobial resistance. The present findings may explain the resistance of C. perfringens to the examined antibacterials and recommend avoiding the application of them to control the microbe. In addition, the authors recommend following strict hygienic procedures during the industry of herbs and spices to ensure their clearance from Clostridium perfringens before distributing the products as food additives into the markets.