Question

2 useful bacteria and 2 harmful bacteria

Answer 1

Helpful Bacteria

Lactobacillus/ Doderlein’s bacillus
Bifidobacterium

harmful bacteria
Mycobacteria
Clostridium tetani

Answer 2

Useful bacteria :
Lactobacillus (The bacterium in milk)
E.coli (the bacterium in human intestines that help in digestion)

Harmful bacteria :
Campylobacter(That causes diarrhea)
Staphylococcus (that causes acne)

Hope this helps ya ✌️✌️