When we breathe, we expose our bodies to a wide range of bacteria. Generally, these bacteria originate near the main carina, the portion of the trachea where the airway branches out to the left and right lungs. The main carina also serves as a landing pad for aspirated saliva. Moreover, our upright posture and gravity cause bacteria to collide with the airway. In addition, some bacteria make their way into the deepest pulmonary system, where they live in tiny air sacs called alveoli.
Exhaled breath
The bacterial pathogens in our breath are mostly microscopic and pose a higher risk of transmission than larger organisms. Our exhaled breath contains millions of bacterial particles per minute. About 17% of this number is in fluorescent bioaerosol. These particles are present at a concentration of 1.93 x 105 CFU/m3, with a peak diameter of 1.5 um. Human activities, such as coughing and sneezing, re-suspend these particles.
The bacterial pathogens detected in exhaled breath included E. coli, P. aeruginosa, and MRSA. One subject showed evidence of all three. In addition, in the study, 25 out of 69 throat swabs were positive for at least one type of bacterial pathogen, and five specimens had two or more pathogens present. Higher positive rates were found for H. influenzae, which is likely the cause of most upper respiratory tract infections.
The population of bacteria in our lungs resembles that of our mouth. This was found by a study that examined how bacteria spread throughout our airways. This allowed researchers to identify the most common route of entry for bacteria. Some bacteria also make it to the deepest pulmonary system, where they live in the air sacs called alveoli.
Microaspiration
Microaspiration is the inhalation of a small amount of saliva and bacteria from the mouth and throat during breathing. It may occur in as many as 10% of healthy people. However, it occurs much more frequently in vulnerable populations. In fact, it has been found in 70 percent of patients with acute pneumonia. It has been linked to poor oral health and has been implicated in several adverse pulmonary outcomes, including aspiration pneumonia.
Healthy have a relatively homogenous microbial community. But when we start to study bacteria in our lungs, the situation is different. This is because microaspiration is the primary route for microbial immigration. In healthy volunteers, micro-aspiration occurs, but the bacteria are still present in the bronchoalveolar lavage fluid.
Airborne transmission
There are several ways that you can prevent the spread of bacteria, viruses, and fungi. These methods include practicing good health practices, such as hand washing, and avoiding contact with sick people. In addition, you should avoid breathing contaminated air. In addition, there are ways to limit the spread of bacteria and fungi by increasing the ventilation in your house or workplace.
One of the most effective ways to reduce the spread of bacteria, viruses, and fungi is to avoid touching people who are sick. You should also wear a mask or cover your mouth with a tissue when you cough or sneeze. Using hand sanitizer is also helpful. Avoid touching other people's faces when you're sick, as germs can remain on your hands after a long time. Similarly, proper hand washing and environmental controls can reduce the spread of water droplet-borne pathogens.
In addition to airborne transmission, bacteria can be transmitted to humans through surfaces and dust. Many diseases are spread through different routes, but airborne transmission is the most unpredictable. While the air is a very effective medium for transferring bacteria, only a few types of bacteria can be spread through the air. Instead, they linger on respiratory droplets and dust particles, which are then breathed in by other people. In some cases, no physical contact is required, but you don't want to risk getting sick.
As far as preventing airborne transmission of bacteria goes, this method of spreading bacteria is not perfect, but it's not as bad as it seems. The airborne particles that carry these pathogens are usually very small and can remain on surfaces and infected people. These particles can move a long distance and stay infectious for minutes or hours. Consequently, proper ventilation and personal protective equipment are essential in preventing the spread of bacteria and fungi.
The most common route of airborne transmission of SARS-CoV-2 is through respiratory aerosol. These particles, which are often a few micrometers in diameter, pose the greatest risk of infection. The size of these aerosol particles determines the probability of the bacterium being inhaled.