Mycobacterium tuberculosis can spread from person to person through the respiratory tract, making it essential to understand its survival characteristics, including how long it can live in the air and the conditions that lead to its death. This knowledge is crucial for effectively preventing Tuberculosis (TB) infection.
1. Basic characteristics of Mycobacterium tuberculosis
Mycobacterium tuberculosis is a bacilli that measures approximately 0.4 x 3-5 mm in size. It has no shells, hairs, or spores. This bacilli often appear in small clusters resembling the letters N, V, or Y, or it may exist individually. Unlike many other bacteria, Mycobacterium tuberculosis cannot be stained using conventional methods; however, it does stain red when viewed under Ziehl-Neelsen stained slides.
Mycobacterium tuberculosis is strictly aerobic, meaning it needs oxygen and cannot grow in normal environments. It requires a nutrient-rich environment to thrive and have a slow growth rate, with a division time of about 18 hours for each division.
Bacteria cause pulmonary tuberculosis, peritoneal tuberculosis, and lymph node tuberculosis..., exhibit high resistance to dry conditions and other physical and chemical factors, known as alcohol-resistant and acid-resistant bacteria, chemicals used to kill tuberculosis bacteria require high concentrations and long contact times to be effective.
2. How long does Mycobacterium tuberculosis survive in the air?
The survival time of Mycobacterium tuberculosis in the air depends on several key factors, including temperature, humidity, and light exposure. The survival characteristics of Mycobacterium tuberculosis are as follows:
- Mycobacterium tuberculosis can survive in the air for about 3 to 4 months.
- In damp, dark environments, these bacteria can remain viable for up to 3 months while still retaining their ability to cause infection.
- Since Mycobacterium tuberculosis is aerobic, it is typically found in the highest numbers within tuberculous cavities that have open bronchi, which offer a rich oxygen supply.
5. At what temperature does Mycobacterium tuberculosis die?
At what temperature does Mycobacterium tuberculosis die? This is a question that many people are interested in. Under different conditions of temperature as well as physicochemical agents, Mycobacterium tuberculosis will survive for different periods:
- Under sunlight: Mycobacterium tuberculosis typically dies after about 1.5 hours.
- At a temperature of 42°C: Mycobacterium tuberculosis stops growing.
- At temperatures of 80°C or higher: Mycobacterium tuberculosis dies within 10 minutes.
- With exposure to ultraviolet rays: Mycobacterium tuberculosis can survive for only about 2 to 3 minutes.
- In 90% alcohol: Mycobacterium tuberculosis is destroyed after 3 minutes.
- In 5% phenol (phenic acid): Mycobacterium tuberculosis can survive for approximately 1 minute.
