chlorine resistant microorganisms

• Cryptosporidium
• Giardia lamblia cysts
• Hepatitis A virus
• Polio 1>2 >3
• H.pylori
• E.Coli cysts
• Helminthes
• M.avium (2000  times more resistant than E.Coli)

Note-- chlorine has bactericidal,virucidal & at higher concentrations sporicidal action
enteric viruses &  protozoan parasites are more resistant to  chlorine than bacteria(E.Coli)
Hepatitis A virus is more heat stable than another enteroviruses
Enteroviruses are more resistant to ionising radiation than  bacteria

Microbes ranked in order of decreasing resistance to disinfectants

1. Spores
2. Mycobacterium tuberculosis
3. Non-lipid viruses (i.e., hepatitis A, poliovirus) 
4. Fungi
5. Vegetative bacteria
6. Lipid viruses (i.e., HIV)