Escherichia Coli

Most E. coli are not pathogenic, but some serotypes can cause severe food poisoning or food contamination.

Escherichia coli is often used as a sign of fecal contamination E. coli, which is generally harmless to the human body, can also cause disease in the following situations:

When bacteria leave the intestine and enter the urinary tract can cause infections.

When bacteria enter the abdominal cavity due to perforations such as ulcers, it usually causes a fatal peritonitis infection.

Some strains of E. coli are toxic (some of which are similar to toxins that cause dysentery), can cause food poisoning, and the severity of the disease can be much different, especially fatal to children, the elderly and immunocompromised patients


Legionella Pneumophila

Legionella is a kind of Gram-negative bacteria. It is Legionella pneumophila that causes Legionnaires’ Disease.

Legionella is aerobic and can survive for a long time in nature. For example, it can survive for more than 100 days in distilled water and one year in sewage.

In 1976, a veterans conference was held in Philadelphia, Pennsylvania, USA. More than 200 of the participants had pneumonia, and 34 of them were dead. It was found that the culprit of the incident was a bacteria that had not been found at the time-Legionella pneumophila (the disease was therefore named Legionnaires’ Disease). This incident reflects that Legionella pneumophila is not a small-scale human-to-human transmission.