Question

In 2000, on a farm in North Dakota, 67-year-old Caleb helped bury five cows that had died of anthrax. Wearing heavy leather gloves, Caleb placed chains around the heads and hooves of the carcasses and moved them to the burial site. Four days later, he noticed a small lump on his left cheek. Over two days, the lump enlarged and a lesion opened. Caleb then sought medical attention. The physician reported a firm, superficial nodule surrounded by a purple ring, with an overlying black eschar (piece of dead tissue sloughed from the skin). The physician prescribed ciprofloxacin, the standard antibiotic for cutaneous (affecting skin) anthrax. Testing the patient’s serum with a bacterial antigen revealed the presence of antibodies, confirming the diagnosis of anthrax. The ciprofloxacin was continued, and the patient slowly improved over several weeks.
If this scenario were an application of Koch’s postulates rather than a natural infection, which of these case notes would NOT be relevant?

	a.	Caleb developed a lesion similar to those affecting the dead cows.
	b.	Bacillus anthracis can be isolated from lesions on all dead cows.
	c.	Bacillus anthracis can be isolated from Caleb’s lesion.
	d.	Antibiotics successfully treated the lesion.

Answer 1

Answer-

Koch’s postulates- According to this

• Bacillus anthracis can be isolated from lesions on all dead cows.
• Caleb developed a lesion similar to those affecting the dead cows.

Not relevent.-

• Bacillus anthracis can be isolated from Caleb’s lesion. because suspected causative agent present only in diseased organism.
• if Antibiotics successfully treated the lession then there was no presence of any causative agent.