Bacteria and the Use of Antibiotics

What bacteria are
Disease-causing bacteria often associated with indoor air quality
Antibiotics and Bacteria

What Bacteria Are

Bacteria are living, biological contaminants that can be transmitted by infected people, animals and indoor air. Bacteria can be carried by soil, plant debris, or through the air. They typically make up one-third of all airborne, living organisms.¹ Gram-negative bacteria, like other biological contaminants, contribute to poor indoor air quality and may be a major cause of days lost from work and school. These bacteria can grow in water-damaged buildings and may be the cause of indoor air quality (IAQ) complaints. Some bacteria are transmitted by infected people, contaminated water systems, contaminated air handling systems in homes and buildings, moisture damaged materials, and animals. This is particularly a problem in enclosed areas where there are many people such as correctional facilities, schools, office buildings and military training centers.

In addition to infected people and animals, water sources and water damaged materials; the outdoor air can also be a source for bacteria indoors, especially in rural areas or locations with nearby agricultural practices and wastewater treatment processes. In particular, harvesting/combine operations generate plumes of bacteria and fungi that are carried downwind. Composting facilities and municipal landfills where decomposing organic matter is stored can also increase airborne bacterial concentrations.

Endotoxins have been associated with disease such as byssinosis from cotton dust and organic dust toxicity from silos and barns. IAQ studies show a correlation between respiratory irritation and endotoxin levels. Endotoxin, which is a big product of gram-negative bacteria, can also be found on plants before harvested, in metalworking fluids, humidifiers and air washers. Levels of endotoxins found indoors in excess of those found outdoors are considered significant exposures. Endotoxins can be measured in building air, dust, and materials. Elevated levels indicate the presence of gram-negative bacteria that may be unusual. This testing is used by IAQ field investigations for a quick analysis of bacteria presence.

Gram-positive bacteria are also common in buildings and homes, and include Staphylococcus and Micrococcus, which are found on human skin scales. Some species of Staphylococcus are emitted from the nasopharynx of individuals when a person talks. In general, the presence of these bacteria indicate the presence of people and their levels may get high when the building is heavily populated. However, adverse health effects from gram-positive bacteria are not likely.

When most people think of bacteria, they think of disease-causing organisms, such as the bacteria that cause tuberculosis. However, disease-causing bacteria are only a fraction of the bacteria as a whole. Some bacteria in our body can help with things like the digestion of food.

Some of the disease-causing bacteria often associated with indoor air quality include:

• Legionella

• Coxiella burnetti (Q fever): Q fever commonly occurs in cattle, sheep, and goats. These animals produce contaminated dust and aerosols found in the milk, urine, or feces that can be inhaled. Dust contaminated with this bacterium may also be spread by the wind.

• Staphylococcus aureus: This is commonly found in air, water, the skin and upper throat of normally healthy people.

• Mycobacterium tuberculosis.

• Pseudomonas, Flavobacterium and Blastobacter: These grow in stagnant water such as in humidifiers and sumps or on wet surfaces of air- conditioning systems, cooling coils, drain pans, or sump pumps.

Bacterial concentrations may be high at both low and high levels of relative humidity; therefore, one should maintain indoor humidity levels between 40 percent and 60 percent.

Antibiotics and Bacteria

Bacteria may cause infections and these infections may be treated with antibiotics. In most cases, the doctor may want to take a sample of the infectious material and send it to a laboratory to be analyzed. Once the results are back from this culture, the doctor will know what antibiotic to prescribe.

If your doctor prescribes an antibiotic, it is important to follow these steps:

• DO take the ENTIRE prescribed antibiotic unless another antibiotic is prescribed by your doctor.

• DO NOT stop taking the antibiotic when you begin feeling better

• DO NOT share antibiotics with other family members

• DO NOT "save" antibiotics for a time when you might get sick again.

• DO NOT flush unused antibiotics down the toilet. They can get into the water system and kill off "good" bacteria that help break down waste, and sensitize "bad" bacteria so that they may become resistant to that antibiotic.

• DO consider eating yogurt or acidophilus (found at health food stores) containing "active cultures." When you take antibiotics, they often knock off some of the "good" bacteria in your digestive system that can lead to things like diarrhea or yeast infections.

The reason for doing these things is that even though you may be feeling better, some of the infection may still be in your body. If there is not enough antibiotic to completely knock out the infection, the bacterial organisms can learn to adapt to the low levels of antibiotic until they become resistant to it and that antibiotic no longer works for that type of infection. These drug-resistant organisms are extremely dangerous because they can result in super infections throughout the body. These drug-resistant organisms can then be transmitted to other people. Today many bacteria are becoming resistant to antibiotics at a faster pace than science is able to develop new antibiotics so this could be even more of a problem in the future.

Because of the threat of drug-resistant organisms, it is also important that you see your doctor again if you are running out of an antibiotic and you still have an infection. You may need to take the antibiotic longer for it to do its work or you may need another antibiotic altogether. This is especially true of infections in hard to reach places like sinuses and bones.

Reference

1. Trudeau WL, Fernández-Caldas E. Identifying and measuring indoor biologic agents. J Allergy Clin Immunol. 1994;94(issue 2, part 2):393-400.