Selection of a Clostridium perfringens type D epsilon toxin producer via dot-blot test.
Clostridium perfringens type D produces enterotoxemia, an enteric disease in ruminants, also known as pulpy kidney disease. Caused by epsilon toxin, enterotoxemia is a major exotoxin produced by this microorganism. Epsilon toxin is also the main component of vaccines against this enteric disorder. In this study, a standardized dot-blot was used to choose strains of C. perfringens type D that are producers of epsilon toxin. Clones producing epsilon toxin were chosen by limiting dilution; after three passages, lethal minimum dose titers were determined by soroneutralization test in mice. These clones produced epsilon toxin 240 times more concentrated than the original strain. The presence of the epsilon toxin gene (etx) was verified by polymerase chain reaction. All clones were positive, including those determined to be negative by dot-blot tests, suggesting that mechanisms in addition to the presence of the etx gene can influence toxin production. The dot-blot test was efficient for the selection of toxigenic colonies of C. perfringens type D and demonstrated that homogeneous populations selected from toxigenic cultures produce higher titers of epsilon toxin.
Anaerobians Laboratory, Department of Preventive Veterinary Medicine, Veterinary School of Federal University of Minas Gerais, Antônio Carlos Avenue, 6627, Belo Horizonte, Brazil.
Luciana A
LA
Gonçalves
Zélia I P
ZI
Lobato
Rodrigo O S
RO
Silva
Felipe M
FM
Salvarani
Prhiscylla S
PS
Pires
Ronnie A
RA
Assis
Francisco C F
FC
Lobato
D000818:Animals; D001427:Bacterial Toxins / Q000096:biosynthesis* / Q000633:toxicity; D001428:Bacterial Vaccines; D003016:Clostridium perfringens / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D015151:Immunoblotting; D051379:Mice; D016133:Polymerase Chain Reaction; D018675:Toxicity Tests
D001427:Bacterial Toxins; D001428:Bacterial Vaccines; C039811:Clostridium perfringens epsilon-toxin; D004269:DNA, Bacterial