Pertussis toxin "Bordetella" is that "B. pertussis" produces PT and the other species do not. "Bordetella parapertussis" shows the most similarity to "B. pertussis" and was therefore used for research determining the role of PT in causing the typical symptoms of whooping cough. Rat studies showed the development of paroxysmal coughing, a characteristic for whooping cough, occurred in rats infected with "B. pertussis". Rats infected with "B. parapertussis" or a PT-deficient mutant of "B. pertussis" did not show this symptom; neither of these two strains produced PT. A large group of bacterial exotoxins are referred to as "A/B toxins", in essence because
White line disease wall resection or debridement. Sometimes, if the problem is severe enough, the horse may need to be specially shod with a heart-bar shoe. White line disease White line disease (also known as seedy toe) is a fungal infection of the horse's hoof. As the name suggests, it attacks the white line, which connects the sole to the hoof wall. It is sometimes mistaken for hoof wall separation disease, but is not to be confused because it is not genetic nor as severe. White line disease changes the typical light color of the white line to a black or dark gray