Actinomyces species are anaerobic, gram-positive bacteria that are commonly found in the human mouth and digestive tract. They are also found in soil and water. Actinomyces species are part of the normal flora of the mouth and digestive tract, but can become pathogenic when the normal balance of flora is disrupted or the immune system is weakened.
The most common cause of Actinomyces species is poor oral hygiene. Poor oral hygiene can lead to the accumulation of plaque, tartar, and food debris in the mouth. These provide a suitable environment for the growth of Actinomyces species, as they are anaerobic and thrive in these conditions.
Other causes of Actinomyces species include dental procedures, such as the placement of dental crowns, bridges, and implants; trauma to the mouth; and the use of certain medications, such as antibiotics, which can disrupt the normal balance of flora in the mouth and digestive tract.
Actinomyces species can also be transmitted from person to person through contact with saliva, such as through kissing. Additionally, people who have a weakened immune system, such as those with HIV/AIDS, are more prone to developing infections caused by Actinomyces species.
In conclusion, poor oral hygiene, dental procedures, trauma to the mouth, the use of certain medications, and a weakened immune system can all lead to the growth of Actinomyces species.