Bacterial conjunctivitis is a common type of pink eye, caused by bacteria that infect the eye through various sources of contamination. The bacteria can be spread through contact with an infected individual, exposure to contaminated surfaces or through other means such as sinus or ear infections.he most common types of bacteria that cause bacterial conjunctivitis include Staphylococcus aureus, Haemophilus influenzae, Streptococcus pneumoniae and Pseudomonas aeruginosa. Bacterial conjunctivitis usually produces a thick eye discharge or pus and can affect one or both eyes.