Education, Infectious Diseases

A Guide to Bacterial Infections

Author Kimberly Hazel , 10-May-2022

Bacteria are some of the most common organisms in the world, affecting humans and other living things alike. They can cause a wide range of infections, from minor rashes to serious illnesses that require medical attention. Some of the most common bacterial infections include pneumonia, strep throat, urinary tract infections, blood poisoning, food poisoning, and sepsis.


These bacteria can be transmitted in many different ways: they can be picked up from direct contact with an infected person or animal, transmitted via contaminated food or water, or spread through the air through droplets released when an infected individual coughs or sneezes.


In addition, bacteria often thrive in moist environments like bathrooms and kitchens where bacteria-laden surfaces provide ideal breeding grounds for bacteria to take hold and multiply. These conditions make it crucial to take precautions against bacterial infections by practicing good hygiene and regularly disinfecting commonly used surfaces.


By staying informed about the various types of bacterial infections and taking steps to prevent them, we can make our homes safer places for ourselves and our loved ones.

Not All Bacteria are Bad


Bacteria are microorganisms that can be either single-celled or multi-cellular. They are among the most common organisms on Earth and play a vital role in human health and the environment.

Bacteria come in many shapes and sizes, but all of them have one common feature: they are made of cells. Cells are the smallest units of life and bacteria are no exception; they consist of a single cell or a colony of cells. Bacteria can be either free-living or parasitic, and some forms can cause disease in humans, animals, and plants.

Despite their bad reputation, most bacteria are harmless and play important roles in human health and the environment. Some of the most important include Lactobacillus and Bifidobacterium, which are both commonly found in yogurt. These bacteria help break down food in the gut, and they also produce vitamins and other nutrients that are essential for good health. Other good bacteria can be found in fermented foods like sauerkraut, kimchi, and kefir. They are also present in soil and on plants

Of course, some types of bacteria are harmful and can cause infections in humans. Bacterial infections can range from mild to life-threatening and can occur anywhere in the body.

What is a Bacterial Infection?


Bacterial infection refers to the invasion of bacteria into the host organism. The bacteria can either be enveloped or naked. The disease caused by this infection is called bacterial disease. Various types of bacteria can cause infections like gram-positive cocci, gram-negative bacilli, and spirochetes. Bacterial infections occur in a variety of ways and in various body systems.

These bacteria can enter the body through breaks in the skin, or by coming into contact with contaminated surfaces, food, or water. Once inside the body, these bacteria can multiply and cause an infection. These infections can range from mild to severe, and in some cases can even be deadly.

The Most Common Bacterial Infections


There are many types of bacterial infections that can affect humans, but some are more common than others. Some of the most common types of bacterial infection include:


Other common bacterial infections include:

  • urinary tract infections (UTIs)
  • respiratory infections (such as pneumonia or bronchitis)
  • skin infections (such as cellulitis or impetigo)
  • sexually transmitted infections (STIs) (such as chlamydia or gonorrhea)

Symptoms Related to Bacterial Infections


Symptoms of bacterial infection depend on the type of infection but may include:

  • fever or chill
  • body aches
  • fatigue
  • coughing
  • shortness of breath
  • diarrhea
  • nausea/vomiting
  • abdominal pain


How is The Infection Diagnosed?


A doctor diagnoses a bacterial infection by considering the patient’s symptoms and medical history and then performing a physical examination. If a bacterial infection is suspected, the doctor may order laboratory tests, such as blood tests or cultures to confirm the diagnosis.


So, in short: bacterial infections are diagnosed by looking at the symptoms or signs and then doing a lab test to confirm the infection.

Treatment for Bacterial Infections


Doctors treat bacterial infections by prescribing antibiotics. Antibiotics are drugs that kill bacteria or prevent them from multiplying. They are usually taken by mouth in pills, capsules, or liquids, but some types can be given intravenously (through a vein).


A doctor will likely prescribe a specific antibiotic to treat infection based on several factors, including the type of bacteria causing it, medical history, and allergies.


It’s essential to take the entire course of antibiotics as prescribed to fully rid your body of the infection. Taking shortcuts or stopping early may allow some bacteria to survive and continue causing problems.


What is an Antibiotic, and How Does it Work?


An antibiotic is a substance that kills or inhibits the growth of bacteria. Antibiotics are used to treat infections caused by bacteria, but they are not effective against viruses.

The mechanism of action of antibiotics depends on the type of antibiotic. For example, some antibiotics work by interfering with the bacterial cell wall, while others work by inhibiting protein synthesis. The main classes of antibiotics include penicillins, cephalosporins, macrolides, tetracyclines, and aminoglycosides.

This means that type of antibiotic depends on the particular bacteria causing the infection.

In some cases, more than one type of antibiotic may be needed. Antibiotics are usually taken for 10 days to two weeks. The length of treatment depends on the severity of the infection and how well the antibiotics work.

Modes of Transmission: How Bacteria are Spread and Why They are Infectious


There are a few different ways that bacteria can spread. These are known as modes of transmission. These modes include contact, airborne, droplet, vectors, and vehicular (contaminated inanimate objects such as food, water, and fomites).

Contact Spread or Surface Spread


Contact transmission for bacteria occurs when the bacteria are transferred from one person to another through direct contact. This can happen through things like shaking hands, sharing utensils, or even touching something that someone else with the bacteria has touched. When someone touches a surface that contains bacteria, they can transfer those bacteria to their own hands. If they then touch their face, the bacteria can enter their body through their eyes, nose, or mouth.

There is also a transmission mode known as indirect contact. This includes examples such as touching a doorknob that someone with the bacteria has touched. Bacteria can live on surfaces for a surprisingly long time. Some bacteria can survive for up to a week on dry surfaces! However, the amount of time bacteria can survive on wet surfaces depends on the environment and the type of bacterium. Some bacteria can stay alive for months or even years in the water!

Contact transmission is important for the spread of many diseases, including strep throat and MRSA.

Airborne Spread


Another way that bacteria can spread is through the air. Bacteria can be released into the air when somebody coughs or sneezes. These airborne bacteria can then be inhaled by other people, causing them to become ill.

This happens because some bacteria are carried on air currents in droplet nuclei, which is commonly known as an airborne or aerosol spread. Many types of bacteria can be spread through the air, but some of the most common include Streptococcus, Staphylococcus, and Haemophilus influenza.

Droplet Spread


Consolidated or droplet spread on the other hand is one of the main ways bacteria reproduce and cause disease. Droplet spread is unique because it occurs when an infected droplet is expelled from the mouth or nose and deposited on a surface. From there, the bacteria can easily infect someone who touches the surface.

This type of transmission is responsible for many outbreaks of respiratory illnesses, such as the flu. Because these are heavier nuclei, they are not technically considered aerosol or airborne modes of transmission. Some experts consider droplet spread more similar to contact spread while others feel that it is a mode of transmission all on its own.

Vector Spread


Vector spread for bacteria is the transfer of the pathogen from one host to another. There are many ways that this can happen, but most experts consider vector spread to be spread through insect bites. This usually takes place via the arthropod (mosquito, tick, louse) taking a blood meal from an infected host and transferring pathogens to an uninfected individual.

Vector-borne illnesses account for a significant proportion of the global disease burden and can be very serious. Some examples of vector-borne bacteria include malaria, Lyme disease, and dengue fever.

Vehicular Spread: Food or Water Contamination


The vehicular spread of bacteria refers to the spread of bacteria from one area to another via a vehicle. Vehicles of a bacterial spread most often include food, water, and fomites.

Bacteria can be spread by food and water in a few ways. Most commonly, it can be spread by food and water that have not been cooked or washed properly.

A fomite is an inanimate object that can harbor and transmit pathogens. Fomites include anything from doorknobs to towels to utensils. Common fomites in this mode of transmission are hands and skin.

Preventing the Spread of Bacteria and Heading Off Bacterial Infections for Your Health


Globally, mortality due to bacterial infections is estimated to be over 15 million people each year – more than HIV/AIDS, tuberculosis, and malaria combined. Given the enormous burden that bacteria pose to public health, preventing the spread of these microbes is critical. Here are a few tips on how you can help prevent the spread of bacteria.

Wash your hands regularly and thoroughly with soap and water. This is perhaps the simplest and most effective way to prevent the spread of bacteria. Stepping up handwashing efforts could reduce childhood mortality from pneumonia and diarrheal diseases by as much as 50%. This is why it is commonly said, “the best way to prevent bacterial infections is to practice good hygiene”.

Cook food properly. Undercooked meat and poultry are common sources of bacterial infections. Make sure to cook these items thoroughly to kill any bacteria that may be present.

Avoid sharing personal items. Bacteria can easily spread through contact with personal items, such as towels, clothing, and utensils. If you must share these items, make sure to wash them thoroughly afterward.

Disinfect surfaces regularly. Bacteria can live on surfaces for long periods. To prevent the spread of bacteria, it is important to clean and disinfect surfaces regularly, especially those that are frequently touched (doorknobs, countertops, etc.).

Vaccinate against bacterial diseases. Many bacterial diseases can be prevented through vaccination. Vaccines are available for several bacterial diseases, such as pertussis (whooping cough), meningococcal disease, and pneumococcal disease.

Bacterial infections can be serious, but they are often preventable. By following the above tips, you can help reduce your risk of infection.

Kimberly Hazel

Articles you won’t delete.
Delivered to your inbox weekly.