Toxin genotypes of Clostridium perfringens in animal feed and their role in the ethiology of enterotoxemia in domestic animals

Abstract

Clostridium perfringens is a Gram-positive, endospore-forming, anaerobic rod, ubiquitous in nature. C. perfringens strains can produce about 17 toxins. Many of them can lead to miscellaneous diseases, among which the enteric ailment may be the most common and is of utmost importance. In the present work 34 strains of C. perfringens isolated from feed and one from a cow suspected to have died of clostridial infection were subjected to molecular analysis. In order to detect the genotypes, the following genes coding for toxins were targetted: cpa, cpb, cpb2, cpe, etx and iap. The multiplex PCR assay revealed that all C. perfringens isolates from animal feed were of type A and b2-toxinogenic type A strains, possessing only the cpa (n=21), or both the cpa and the cpb2 genes (n=13). The importance of C. perfringens toxins α and β-2 in the pathogenesis of enterotoxemia is discussed and the regulation on the detection of this bacteria in animal feed questioned. The use of PCR in practise could enable the toxin-genotyping of C. perfringens isolates and, thus, provide a real basis for the establishment of maximum acceptable limits of this bacteria in feed.

Clostridium perfringens je Gram-pozitivna, anaerobna, sporulišuća, štapićasta bakterija, ubikvitarno rasprostranjena u prirodi. Kod različitih sojeva C. Perfringens, do danas, identifikovano je oko 17 vrsta toksina. C. perfringens je uzročni agens različitih oboljenja (sindroma), ali su crevne infekcije/intoksikacije najčešće i od najvećeg značaja za zdravlje farmski gajenih životinja. U ovom radu prikazujemo rezultate ispitivanja sojeva C. perfringens poreklom iz hrane za životinje (n=34) i jednog izolata iz organa krave uginule sa znacima enterotoksemije na prisustvo gena: cpa, cpb, cpb2, cpe, etx i iap primenom multipleks PCR tehnike. Svi sojevi C. perfringens izolovani iz hrane za životinje, identifikovani su kao tip A koji poseduje samo cpa gen (n=21) ili tip A koji produkuje b2-toksin, odnosno ima cpa i cpb2 gene (n=13). U radu diskutujemo o ulozi alfa (α) i beta-2 (β2) toksina u patogenezi enterotoksemija domaćih životinja, kao i aktuelnom zakonskom propisu po kojem ova vrsta bakterije ne sme biti prisutna u hrani za životinje. Primena PCR tehnike u svakodnevnoj praksi omogućila bi toksin-genotipizaciju sojeva C. perfringens, a time i realne osnove za uspostavljanje graničnih dozvoljenih vrednosti za ovu vrstu bakterije u hrani za životinje.