Color-enhanced scanning electron micrograph showing Salmonella typhimurium (red) invading cultured human cells

Bacteria are vital for the maintenance of human health, but they also pose and a significant health threat by causing disease. There are 10 times more bacterial cells than human cells in the human body, with large numbers of bacteria on the skin and in the digestive tract. Due to their small size, commensal bacteria are ubiquitous and grow on animals and plants exactly as they will grow on any other surface. However, their growth can be increased by warmth and sweat and large populations of these organisms in humans are the cause of body odor. The presence of over 1,000 bacterial species in the normal human gut flora of the intestines can contribute to gut immunity, synthesise vitamins such as folic acid, vitamin K and biotin, as well as fermenting complex undigestable carbohydrates.^[1][2] Bacteria that offer some benefit to human hosts include Lactobacillus species, which convert milk protein to lactic acid in the gut.^[3] The presence of such bacterial colonies also inhibits the growth of potentially pathogenic bacteria (usually through competitive exclusion) and these beneficial bacteria are consequently sold as probiotic dietary supplements.^[4] ImageMetadata File history File links Download high resolution version (2100x1761, 1696 KB) Color-enhanced scanning electron micrograph showing Salmonella typhimurium (red) invading cultured human cells Credit: Rocky Mountain Laboratories, NIAID, NIH Source: NIAID: File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to... ImageMetadata File history File links Download high resolution version (2100x1761, 1696 KB) Color-enhanced scanning electron micrograph showing Salmonella typhimurium (red) invading cultured human cells Credit: Rocky Mountain Laboratories, NIAID, NIH Source: NIAID: File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to... Binomial name Salmonella enterica Salmonella enterica is a species of Salmonella bacterium. ... Kingdoms Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ... Bromhidrosis or body odour (also called bromidrosis, osmidrosis and ozochrotia) is the smell of bacteria growing on the body. ... Gut flora, or intestinal bacteria, are the bacteria that normally live in the digestive tract and perform a number of useful functions involving digestion for their hosts. ... Retinol (Vitamin A) Vitamins are nutrients required in very small amounts for essential metabolic reactions in the body [1]. The term vitamin does not encompass other essential nutrients such as dietary minerals, essential fatty acids, or essential amino acids. ... Folic acid and folate (the anion form) are forms of a water-soluble B vitamin. ... Vitamin K denotes a group of 2-methilo-naphthoquinone derivatives. ... Biotin, also known as vitamin H or B7 and C10H16N2O3S (Biotin; Coenzyme R, Biopeiderm), is a water-soluble B-complex vitamin which is composed of an ureido (tetrahydroimidizalone) ring fused with a tetrahydrothiophene ring. ... Lactose is a disaccharide found in milk. ... Species L. acidophilus L. bulgaricus L. casei L. plantarum L. reuterietc. ... The competitive exclusion principle, sometimes referred to as Gauses Law of competitive exclusion or just Gauses Law, states that two species that compete for the exact same resources cannot stably coexist. ... Probiotics are dietary supplements containing potentially beneficial bacteria or yeast, however lactic acid bacteria (LAB) are the most common microbes used. ... A prescribed dietary supplement is intended to supply nutrients (vitamins, minerals, fatty acids or amino acids) that are missing or not consumed in sufficient quantity in a persons diet. ...

Although the vast majority of bacteria are harmless or beneficial, a few pathogenic bacteria cause infectious diseases. The most common bacterial disease is tuberculosis, caused by the bacterium Mycobacterium tuberculosis, which kills about 2 million people a year, mostly in sub-Saharan Africa. Pathogenic bacteria contribute to other globally important diseases, such as pneumonia, which can be caused by bacteria such as Streptococcus and Pseudomonas, and foodborne illnesses, which can be caused by bacteria such as Shigella, Campylobacter and Salmonella. Pathogenic bacteria also cause infections such as tetanus, typhoid fever, diphtheria, syphilis and leprosy. Tuberculosis (abbreviated as TB for Tubercle Bacillus) is a common and deadly infectious disease caused by the bacterium Mycobacterium tuberculosis, which most commonly affects the lungs (pulmonary TB) but can also affect the central nervous system, lymphatic system, circulatory system, genitourinary system, bones and joints. ... Tetanus is a serious and often fatal disease caused by the neurotoxin tetanospasmin which is produced by the Gram-positive, obligate anaerobic bacterium Clostridium tetani. ... Typhoid fever is an illness caused by the bacterium Salmonella Typhi. ... Syphilis is a sexually transmitted infection (STI) caused by a spirochaete bacterium, Treponema pallidum. ... Leprosy, also known as Hansens disease,[1] is an infectious disease caused by a DNA plasmid (transposon, or ultravirus, a small circle of DNA) carried in Hansens bacillus (the Mycobacterium leprae bacterium) which is thus the vector. ...

Koch's postulates, proposed by Robert Koch in 1890, are criteria designed to establish a causal relationship between a causative microbe and a disease. A pathogenic cause for a known medical disease may only be discovered many years after, as was the case with Helicobacter pylori and peptic ulcer disease. M.J has ebola. ... Robert Koch For the American lobbyist, see Bobby Koch. ... Binomial name Helicobacter pylori ((Marshall 1985) Goodwin 1989) Helicobacter pylori is a bacterium that infects the mucus lining of the human stomach. ... Electron micrograph of This is a timeline of the events relating to the discovery that peptic ulcer disease is caused by . ...

Each species of pathogen has a characteristic spectrum of interactions with its human hosts. Some organisms, such as Staphylococcus or Streptococcus, can cause skin infections, pneumonia, meningitis and even overwhelming sepsis, a systemic inflammatory response producing shock, massive vasodilation and death.^[5] Yet these organisms are also part of the normal human flora and usually exist on the skin or in the nose without causing any disease at all. Other organisms invariably cause disease in humans, such as the Rickettsia, which are obligate intracellular parasites able to grow and reproduce only within the cells of other organisms. One species of Rickettsia causes typhus, while another causes Rocky Mountain spotted fever. Chlamydia, another phylum of obligate intracellular parasites, contains species that can cause pneumonia, or urinary tract infection and may be involved in coronary heart disease.^[6] Finally, some species, such as Pseudomonas aeruginosa, Burkholderia cenocepacia, and Mycobacterium avium, are opportunistic pathogens and cause disease mainly in people suffering from immunosuppression or cystic fibrosis.^[7][8] Species S. aureus S. caprae S. epidermidis S. haemolyticus S. hominis S. lugdunensis S. saprophyticus S. warneri S. xylosus Staphylococcus (in Greek staphyle means bunch of grapes and coccos means granule) is a genus of gram-positive bacteria. ... Streptococcus, a genus of spherical, Gram-positive bacteria of the phylum Firmicutes. ... Sepsis (in Greek Σήψις, putrefaction) is a serious medical condition, resulting from the immune response to a severe infection. ... Species Rickettsia felis Rickettsia prowazekii Rickettsia rickettsii Rickettsia typhi Rickettsia conorii etc. ... It has been suggested that this article or section be merged with Epidemic typhus. ... Binomial name Rickettsia rickettsii Wolbach, 1919 Wikispecies has information related to: Ixodidae Wikispecies has information related to: Rickettsia Rocky Mountain spotted fever is the most severe and most frequently reported rickettsial illness in the United States, and has been diagnosed throughout the Americas. ... Chlamydia is a common term for infection with any bacteria belonging to the phylum Chlamydiae. ... It has been suggested that CURB-65 be merged into this article or section. ... A urinary tract infection (UTI) is an infection of the urinary tract. ... It has been suggested that this article or section be merged with Ischaemic heart disease. ... Binomial name Pseudomonas aeruginosa (Schroeter 1872) Migula 1900 Pseudomonas aeruginosa is Gram-negative, aerobic, rod-shaped bacteria with unipolar motility. ... Mycobacterium avium complex refers to infection by two species of bacteria, Mycobacterium avium and Mycobacterium intracellulare. ... Opportunistic infections are infections caused by organisms and usually do not cause disease in a person with a healthy immune system, but can affect people with a poorly functioning or suppressed immune system. ... Immunosuppression is the medical suppression of the immune system. ...

Bacterial infections may be treated with antibiotics, which are classified as bacteriocidal if they kill bacteria, or bacteriostatic if they just prevent bacterial growth. There are many types of antibiotics and each class inhibits a process that is different in the pathogen from that found in the host. An example of how antibiotics produce selective toxicity are chloramphenicol and puromycin, which inhibit the bacterial ribosome, but not the structurally-different eukaryotic ribosome.^[9] Antibiotics are used both in treating human disease and in intensive farming to promote animal growth, where they may be contributing to the rapid development of antibiotic resistance in bacterial populations.^[10] Infections can be prevented by antiseptic measures such as sterilizating the skin prior to piercing it with the needle of a syringe, and by proper care of indwelling catheters. Surgical and dental instruments are also sterilized to prevent contamination and infection by bacteria. Disinfectants such as bleach are used to kill bacteria or other pathogens on surfaces to prevent contamination and further reduce the risk of infection. Staphylococcus aureus - Antibiotics Test plate. ... A bacteriocide or bactericide is a substance that kills bacteria and, preferably, nothing else. ... Bacteriostatic antibiotics hamper the growth of bacteria by interfering with bacteria protein production, interfering with bacteria DNA production interfering with bacteria cellular metabolism Bacteriostatic antibiotics inhibit growth and repoduction of the bacteria, though do not kill it, while bactericidal antibiotics kill bacteria. ... An enzyme inhibitor is a molecule that binds to an enzyme and decreases its rate of reaction. ... Chloramphenicol is a bacteriostatic antibiotic originally derived from the bacterium Streptomyces venezuelae, isolated by David Gottlieb, and introduced into clinical practice in 1949. ... Puromycin is an antibiotic that is a potent inhibitor of translation. ... Figure 1: Ribosome structure indicating small subunit (A) and large subunit (B). ... Intensive Farming Intensive agriculture is an agricultural production system characterized by the significant use of inputs, and seeking to maximize the production. ... Antibiotic resistance is the ability of a microorganism to withstand the effects of an antibiotic. ... An antiseptic solution of iodine applied to a cut An antiseptic (Greek αντι, against, and σηπτικος, putrefactive) is a substance that prevents the growth and reproduction of various microorganisms (such as bacteria, fungi, protozoa, and viruses). ... Sterilization (or sterilisation) is the elimination of all transmissible agents (such as bacteria, prions and viruses) from a surface, a piece of equipment, food or biological culture medium. ... Disinfection The destruction of pathogenic and other kinds of microorganisms by physical or chemical means Disinfectants are chemical substances used to kill viruses and microbes (germs), such as bacteria and fungi. ... Commercial chlorine bleach To bleach something is to remove or lighten its color; a bleach is a chemical that can produce these effects, often via oxidation. ...

References