Eating a lot of fruit is recommended to maintain health. However, you should be careful in choosing fruit. If contaminated, the fruit can cause health problems. Recently, the Indonesian government, through the Ministry of Health, stopped importing melons from Australia's rock melons because they were contaminated with listeria bacteria which caused death. Bacteria Listeria monocytogenes (L. monocytogenes) is somewhat dangerous because although healthy people only give symptoms in the short term, it can cause serious and fatal infections in pregnant women and fetuses, children, the elderly (elderly), and people who are sick or have a weak immune system. Recognizing Listeria Monocytogenes Bacteria Listeria bacteria are classified as gram-positive bacteria. This bacterium is very strong and resistant to heat, acids, and salt. This bacterium is also freezing resistant and can continue to develop at temperatures of 0.4 ° C - 45 ° C with an optimal development temperature of 37 ° C