|Don's Home Health Germs - Pathogens|
|Related Pages: Common Cold | FLu | Disinfecting | Household germs | Traveler's diarrhea | Water Purification|
Germs are generally microbes (living material too small to see) that cause diseases, also called Pathogens.
VirusStructure: Viruses are basically raw genetic material, DNA or RNA with a protein coating (called a capsid). Viruses first attach themselves to healthy cells and then inject their genetic material into those cells. The viral genetic material takes over the cells' operation, forcing the repeated production of viral proteins and genetic material. Eventually, the accumulating viral particles cause the host cell to rupture. This burst sends out large numbers of viruses to repeat the cycle of infection. Viruses are not considered to be living organisms because they cannot reproduce outside of a living cell.
Types: parainfluenza, influenza, respiratory syncytial virus, HIV, rotavirus, ebola, hantavirus, variola
Reproduction: have to invade other cells and hijack their cellular machinery to reproduce.
Size: .01 - .3 µm
mumps, measles, Common Cold, influenza (flu), rabies, hepatitis, poliomyelitis, smallpox, AIDS, polio, Ebola, viral pneumonia,
Chickenpox, Dengue Fever, Ebola, Hepatitis (A, B, or C), Lassa Fever,
Marburg, Meningitis, Poliomyelitis, Rubella (German Measles), Yellow Fever
and certain types of cancer.
Colds Flu Days from infection to symptoms 2-3 1-4 Days contagious after symptoms start 2-3 5-7 Time to run course 1-2 wks 1-2 wks
See virus page for more.
BacteriaStructure: Single-celled organisms without a nucleus and generally ony one chrosome. Many good bacteria live in our bodies, mostly in our digestive tract. Only 300 out of some 4,600 listed species are considered pathogens (disease causing).
All told, the microbes in your body outnumber your own cells by ten to one and can weigh as much as or more than your brain--about three pounds in an average adult.
An imbalanced gut bacteria (more bad bacteria than good bacteria) or diminished bacteria in general (a sterilized gut) will affect your immune function, absorption of essential nutrients, and can promote a perfect environment for the development or maintenance of mental-emotional disorders and serious physical pathologies such as neurological diseases.
Research is now supporting that gut bacteria influences brain development and even behaviour. One study of interest shows that serotonin and dopamine are regulated by colonizing gut bacteria - so these substances (that are often related to depression etc.) don't develop normally in "bad" guts.
Gut bacteria help digest food, absorb nutrients, protect intestinal wals, regulate weight and ward off autoimmune diseases.
Escherichia coli (E. coli), salmonella, Bacillus, staphylococci, enterococci, Campylobacter, shigella and Vibrio parahaemolyticus, Cholera.
Serratia marcescens is a bacteria commonly found in homes and hospitals.
Reproduction: Bacteria have ribosomes, tools necessary for copying DNA so bacteria can reproduce.
Size: .2 - 20 µm
Diseases: Cholera, diphtheria, leprosy, plague, some kinds of pneumonia, strep throat, tetanus, tuberculosis, anthrax, tooth decay, several sexually transmitted diseases, typhoid fever, Legionnaires' Disease, Lyme Disease, Meningitis, Pertussis (Whooping Cough), Strep Infections (Scarlet Fever, Rheumatic Fever, Invasive Strep), Tuberculosis, Typhus.
Parasites - Protozoans (protists)Structure: Single-celled organisms, that may have more than one nucleus. There are 10,000 kinds of parasites, but only a few cause disease in humans
Amoeba, Giardia, Coccidia, Plasmodium falciparum, Trypanosoma, Cryptosporidium, Babesiosis
Size: 15-200 µm
Diseases: Malaria, Trypanosomiasis (African sleeping sickness), Amoebic Dysentery, Chagas' disease, giardiasis, leishmaniasis, and toxoplasmosis.
FungiStructure: Fungi and are generally multicellular, such as molds or mushrooms, but include single-celled yeasts. A single teaspoon of topsoil contains about 120,000 fungi.
Types: gonorrhoeae, Candida, Phytophthora infestans (Irish potato famine), yeast
Reproduction: Division, budding and germination from reproductive cells called spores
Size: 1-100 * µm
Diseases: ringworm, athlete's foot, candidiasis (Thrush) and some kinds of pneumonia, and jock itch
parasitic wormsStructure: multi-celled animals.
Types: Helminths. - flatworms or Platyhelminthes (flukes and tapeworms) and the roundworms or Nematoda.
Reproduction: eggs. Worms do not generally reproduce in the body.
Size: 50-100µm (eggs)
Diseases: Anisakiasis, Elephantiasis, Guinea Worm, Hookworm, River Blindness, Schistosomiasis, Tapeworm, Trichinosis
* Many fungi cells generally cling together so they are large enough to be seen.
An infectious agent composed of protein in a misfolded form.
Also referred to as transmissible spongiform encephalopathies (TSEs), they are a family of rare progressive neurodegenerative disorders that affect both humans and animals.
They are responsible for bovine spongiform encephalopathy (BSE, also known as "mad cow disease") in cattle. In humans, prions cause Creutzfeldt-Jakob Disease (CJD), variant Creutzfeldt-Jakob Disease (vCJD).
They are distinct from other pathogens which contain nucleic acids (either DNA, RNA)
Other Pathogenic Agents
Natural Toxins: Shellfish, Mushroom, Other
Some scientists now believe brain illnesses like mad cow disears are among a few diseases caused by an infectious agents called prions. Prions are not even DNA or RNA, but simply proteins.
Biosafety Risk Groups:
The National Institute of Health has created a list of Human etiologic agents (pathogens) that is categorized into 4 major risk groups. of the National Institutions of Health has created a list of Human etiologic agents (pathogens) that is categorized into 4 major risk groups.
See Risk Groups for the complete list.
The World Health Organization (WHO) has slightly different definitions. See Public Health Emergency page (phe.gov)
Biosafety Levels (BSL) prescribe procedures and levels of containment for the particular microorganism or material (including Research Involving Recombinant or Synthetic Nucleic Acid Molecules). Similar to Risk Groups, BSL are graded from 1 - 4.
A micron (µm) is 1/1000 of a millimeter, a nanometer nm is 1/1000 of a micron.
Diameter of human hair is 50-100 microns.
Viruses can be from 0.02-0.3 µm (100-300 nm)
|Family||Known germs||Size range|
|Viruses||Hepatitis A, Norwalk Virus, Rotavirus, Poliovirus||~0.02 - 0.2 microns|
|Bacteria||E-coli (Escherichia coli), Salmonella (Salmonella typhimurium), Cholera (Vibrio cholerae)||0.2 - 5 microns|
|Protozoans||Amoeobiasis (Entamoeba histolytica), Giardia lamblia (Giardia intestinalis), Cryptosporidium (Cryptosporidumparvum)||1 - 15 microns|
www.scribd.com/doc/24508349/10/GLOBAL-VIEW from www.reise-tropenmedizin.de and
Selection Card Bacteria EN Web at www.katadyn.com/usen/water-knowledge/water-contamination/
Incidence in North America:
An article "Microbiology" in the Dec. 2003 Backpacker states:
An American Water study of treatment plants in 14 US states and one Canadian province in 1991 found:
Giardia 17% of samples Cryptosporidium 27% Standards have been raised since then.A 2003 American Water study of six watersheds found:
Giardia 23% Cryptosporidium 4%However levels of cryptosporidium were so low your chance of ingesting an infectious dose is approximately 1 in 5,000.
Studies showed that it took an average of 132 Cryto cysts to cause a problem.
However if your imune system is compromised because of Chemotherapy, AIDS or other reasons you should be more careful.
See more at water purification under recreation.
The increasing use of antimicrobials in humans, animals, and agriculture has resulted in many pathogens developing resistance to these powerful drugs. All major groups of pathogens viruses, fungi, parasites, and bacteria can become resistant to antimicrobials.
Viruses are generally avoided by increasing immunity with a vaccines before you get sick. A vaccine is a suspension of whole or parts of bacteria or viruses (live or inactivated) that have been engineered so that they don't make the immunized person sick but do induce an immune response and prevent disease.
Examples are the polio and flu vaccines.
Some viruses (e.g. HIV and Hepatitis) use "protease" (an enzyme that breaks down protein) to get into the cell. Drugs called protease inhibitors can be used to fight them.
Neuraminidase inhibitors are a class of antiviral drugs targeted at the influenza virus, which work by blocking the function of the viral neuraminidase protein. e.g Oseltamivir (Tamiflu®) and Zanamivir (Relenza®).
Antiviral treatment as early as possible is recommended for any patients with confirmed or suspected influenza who are hospitalized, seriously ill, or ill and at high risk of serious influenza-related complications, including young children, people 65 and older, people with certain underlying medical conditions and pregnant women.
Antibiotics are used for Bacterial Infections. Some antibiotics work by interfering with the bacteria's ability to build a cell wall (e.g. Penicillin). Antibiotics may also destroy the bacteria's ability to use nutrients or make proteins (e.g. erythromycin, azithromycin and clarithromycin). Still others stop the bacteria from making DNA (e.g. sulfas ( "sulfanilamides" or "sulfonamides"))
Eating and Drinking:
See Flu Recovery Diet
Flu Recovery Diet
Infectious agents and how they cause disease at NIH.gov
Division of Microbiology and Infectious Diseases - DMID at the National Institute of Allergy and Infectious Diseases (NIAID) in the National Institutes of Health (NIH)
Your Kitchen Sponge is Covered With Bacteria -- Don't Bother Cleaning It - D-brief (DiscoverMagazine)
Microbes: Small, Small World | National Geographic
Bad Bug Book at the Center for Food Safety & Applied Nutrition at the FDA
Centers for Disease Control and Prevention
Orthomyxoviridae Influenza Viruses.
Emergency Water Essentials
Gut Health: The Key to our Overall Health and Immunity | K-W Homeopathic Medicine and Wellness Clinic
John and Amy's Influenza Page
Bacteria vs Viruses at DRGreen.com
Cryptosporidium and Water: A Public Health Handbook | CDC
1. Frank DN, St Amand AL, Feldman RA, Boedeker EC, Harpaz N, Pace NR. Molecular-phylogenetic characterization of microbial community imbalances in human inflammatory bowel diseases. Proc Natl Acad Sci USA 104: 13780-13785, 2007.