Bacterial Infections

• Bacterial overview

Bacteria are unicellular organisms that are barely visible under a microscope. Thousands of bacteria are present and inhabit every environment in the world. Bacteria that live in soil, seawater, deep underground, and even radioactive waste have been report. Many bacteria live in human and animal skin, respiratory tracts, mouth, gastrointestinal tract, urethra and genitals without harming the host. Such bacteria called indigenous flora or microbiome.

• What is a bacterium?

　It is a small creature that cannot seen with the eyes. On the other hand, there are bacteria that are useful for human life (such as natto bacteria). There are many types of bacteria in the human body. That maintain the environment on the surface of the skin and in the intestines.

Escherichia coli, Staphylococcus aureus, and Mycobacterium tuberculosis known as bacteria that can cause diseases in humans.

Antibacterial drugs (antibiotics, antibiotics) are drugs for getting rid of bacteria.

Bacteria that are ineffective or difficult to respond to antibacterial drugs called drug-resistant bacteria. When antibacterial drugs that should have worked in the past do not work, not only is it difficult to treat infectious diseases, but also various medical treatments such as prevention of infection during surgery or when immunity is lower by anticancer drug treatment become difficult. Become.

• Bacterial classification

Scientific name: Like other organisms, bacteria are classifies by genus (classification based on similar characteristics) and further by species. The scientific name consists of the name of the genus and the name of the species (for example, the scientific name of Clostridium botulinum is Clostridium botulinum). Different types of species called strains. Strains differ in terms of genetic composition and chemical composition, and certain drugs or vaccines may only be effective against a particular strain.

Staining: Bacteria are classifies according to their color difference when treated with a specific chemical (staining agent). A commonly used dyeing method called Gram stain. Bacteria that stain blue called Gram-positive bacteria. Bacteria that stain red called gram-negative bacteria. Gram-positive and Gram-negative bacteria are stain with different colors due to differences in their cell walls. Depending on the type of these bacteria, the types of infections that occur and the types of effective antibacterial drugs also differ.

Shape: Bacteria are also classified according to their basic shape, and there are three types of shapes: spherical (coccus), rod-shaped (bacillus [kankin]), and spiral (spirochete).

Oxygen Demand: Bacteria are also categorize by their need for oxygen to grow. Bacteria that require oxygen called aerobic bacteria. Those whose presence of oxygen impedes the survival and growth of the bacterium called anaerobic bacteria. Some bacteria, called facultative anaerobes, can grow with or without oxygen.

Gene composition: Special tests can be perform to check for differences in bacterial gene composition (genotype).

• Bacterial defense:

Bacteria protect themselves in a variety of ways.

• Biofilm

There are bacteria that secrete substances to attach to other bacteria, cells, and other things. This substance, together with bacteria, forms a sticky layer called a biofilm.

• Capsular

There are also bacteria that protect themselves by wearing capsules called capsules. The capsule blocks the action of white blood cells, which resist infection and prey on bacteria. Such bacteria are describe as having a capsule.

• Adventitia

Gram-negative bacteria have an outer membrane under the capsule, which protects them from certain antibiotics. When destroyed, this outer membrane releases a toxic substance called endotoxin. In gram-negative bacterial infections, endotoxins contribute to the aggravation of symptoms.

• Spore

Some bacteria form spores that are inactive (dormant). By becoming spores, bacteria can survive in harsh environments. In a better environment, spores will germinate as active bacteria.

Resistant bacteria are also transmit from animals to humans. Resistant bacteria are common in livestock because healthy livestock routinely given antibiotics to prevent growth-inhibiting and disease-causing infections. Many countries ban the use of antibiotics in animals to reduce the following risks:

• Risk of ingesting resistant bacteria contained in livestock meat and processed products
• Risk of infection with resistant strains by contact with animals
• Risk of exposure to antibiotics in livestock meat and processed products
• Bacterial infection

Bacterial infections are classifies based on various methods for classifying bacteria. For example, it is classifies as an infection with Gram-negative bacteria or an infection with Gram-positive bacteria, but it is important to make this distinction. This is because different types of antibiotics may be need to treat these two types of infections.

Infections caused by Gram-negative bacteria include:

• Brucellosis
• Campylobacter infection
• Cat scratch disease
• cholera
• E. coli infection
• Gonorrhea infection
• Infectious diseases caused by Klebsiella, Enterobacter, and Serratia bacteria
• Legionella infection

Infections caused by Gram-positive bacteria include:

• Anthrax
• diphtheria
• Enterococcal infection
• Eligiperoslix disease
• Listeriosis

The shape of the bacteria categorizes some infectious diseases. For example, infections caused by spirochete (spiral bacteria) are classifies as spirochete infections.

Spirochetes infections include:

• Begel, strawberry tumor, pinta
• Leptospirosis
• Lyme disease
• Rat-bite fever
• Relapsing fever
• syphilis

Infectious diseases may also be classifies according to whether the bacteria that cause the infection require oxygen or can live without oxygen. Bacteria that need oxygen to live and grow called aerobic bacteria. Bacteria that do not require oxygen to inhabit and multiply called anaerobic bacteria.