The conditions for the growth and reproduction of bacteria are as follows: ① Sufficient nutrients, including water, carbon source, nitrogen source, inorganic salts, growth factors, etc. ② Suitable pH: The optimum pH for most pathogens is 7.2 ~ 7.6; ③ Suitable temperature: The optimum temperature for most pathogens is 37℃; ④ In the necessary gas environment, the main gases needed are O and CO, obligate aerobic bacteria can grow and reproduce under aerobic conditions, obligate anaerobic bacteria can grow and reproduce under anaerobic conditions, facultative anaerobic bacteria can grow and reproduce under aerobic and anaerobic conditions, and microaerobic bacteria can grow and reproduce under low oxygen pressure. A few pathogenic bacteria, such as Neisseria meningitidis and Neisseria gonorrhoeae, need to provide 5% ~ 10% CO2 for initial isolation and culture.