Mycoplasma genitalium
Encyclopedia
Mycoplasma genitalium is a small parasitic bacterium that lives on the ciliated epithelial cells of the primate
genital and respiratory tract
s. M. genitalium is the smallest known genome that can constitute a cell, and the second-smallest bacterium after the recently-discovered endosymbiont
Carsonella ruddii. Until the discovery of Nanoarchaeum
in 2002, M. genitalium was also considered to be the organism
with the smallest genome
. There is a difference between smallest parasitic bacteria and smallest free living bacteria. The smallest known free living bacteria is the thermophile Aquifex aeolicus with 1.5 Mb and 1512 genes.
s of two male patients with non-gonococcal urethritis
. Infection by M. genitalium seems fairly common, can be transmitted between partners during unprotected sexual intercourse
, and can be treated with antibiotic
s; however, the organism's role in genital diseases is still unclear.
The genome of M. genitalium consists of 521 genes (482 protein encoding genes) in one circular chromosome of 582,970 base pairs. An initial study of the M. genitalium genome with random sequencing was performed by Peterson in 1993. It was then sequenced by Fraser and others. It was found to contain only 470 predicted coding region
s, including gene
s required for DNA replication
, transcription and translation, DNA repair
, cellular transport, and energy metabolism. It was the second complete bacterial genome ever sequenced, after Haemophilus influenzae
. The small genome of M. genitalium made it the organism of choice in The Minimal Genome Project, a study to find the smallest set of genetic material necessary to sustain life
.
This infection is associated with bacterial vaginosis
. In the long term, this infection is suspected to cause pelvic inflammatory disease
.
However, this study Azithromycin Failure in Mycoplasma genitalium Urethritis says that "...doxycycline
and levofloxacin
have substantial failure rates..." and "...Recurrent urethral symptoms following azithromycin therapy only occurred in persons with persistent M. genitalium infection and resolved with moxifloxacin."
So moxifloxacin
appears to be an alternative treatment after one of the other treatments have already failed (Azithromycin
1g is the preferred first-line treatment).
and Nobel laureate Hamilton Smith
announced that they plan to create the first artificial life
form in history by creating a synthetic chromosome, which they plan to inject into the M. genitalium bacterium, with potential to result in an artificial species dubbed Mycoplasma laboratorium
or Mycoplasma JCVI-1.0 after the research centre in which it was created, the J. Craig Venter Institute
in the United States.
On 24 January 2008, the same team reported to have synthesized the complete 582,970-base pair genome of M. genitalium (a key gene that enables the wild organism to cause disease was knocked out). The final stage of synthesis was completed inside a M capricolum
, which had its DNA removed, with the help of yeast cell
s. On 20 May 2010 they reported success with a similar process, using instead the genome of Mycoplasma mycoides, creating what some called the first artificial life.
Primate
A primate is a mammal of the order Primates , which contains prosimians and simians. Primates arose from ancestors that lived in the trees of tropical forests; many primate characteristics represent adaptations to life in this challenging three-dimensional environment...
genital and respiratory tract
Respiration (physiology)
'In physiology, respiration is defined as the transport of oxygen from the outside air to the cells within tissues, and the transport of carbon dioxide in the opposite direction...
s. M. genitalium is the smallest known genome that can constitute a cell, and the second-smallest bacterium after the recently-discovered endosymbiont
Endosymbiont
An endosymbiont is any organism that lives within the body or cells of another organism, i.e. forming an endosymbiosis...
Carsonella ruddii. Until the discovery of Nanoarchaeum
Nanoarchaeum
Nanoarchaeum equitans is a species of tiny microbe, discovered in 2002 in a hydrothermal vent off the coast of Iceland by Karl Stetter. Since it grows in temperatures approaching boiling, it is considered to be a thermophile. Nanoarchaeum appears to be an obligatory symbiont on the archaeon...
in 2002, M. genitalium was also considered to be the organism
Organism
In biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...
with the smallest genome
Genome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....
. There is a difference between smallest parasitic bacteria and smallest free living bacteria. The smallest known free living bacteria is the thermophile Aquifex aeolicus with 1.5 Mb and 1512 genes.
Overview
Mycoplasma genitalium was originally isolated in 1980 from urethral specimenSpecimen
A specimen is a portion/quantity of material for use in testing, examination, or study.BiologyA laboratory specimen is an individual animal, part of an animal, a plant, part of a plant, or a microorganism, used as a representative to study the properties of the whole population of that species or...
s of two male patients with non-gonococcal urethritis
Non-gonococcal urethritis
Nongonococcal urethritis is an inflammation of the urethra that is not caused by gonorrheal infection.For treatment purposes, doctors usually classify infectious urethritis in two categories: gonococcal urethritis, caused by gonorrhea, and nongonococcal urethritis .-Causes:There are many causes of...
. Infection by M. genitalium seems fairly common, can be transmitted between partners during unprotected sexual intercourse
Sexual intercourse
Sexual intercourse, also known as copulation or coitus, commonly refers to the act in which a male's penis enters a female's vagina for the purposes of sexual pleasure or reproduction. The entities may be of opposite sexes, or they may be hermaphroditic, as is the case with snails...
, and can be treated with antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
s; however, the organism's role in genital diseases is still unclear.
The genome of M. genitalium consists of 521 genes (482 protein encoding genes) in one circular chromosome of 582,970 base pairs. An initial study of the M. genitalium genome with random sequencing was performed by Peterson in 1993. It was then sequenced by Fraser and others. It was found to contain only 470 predicted coding region
Coding region
The coding region of a gene, also known as the coding sequence or CDS, is that portion of a gene's DNA or RNA, composed of exons, that codes for protein. The region is bounded nearer the 5' end by a start codon and nearer the 3' end with a stop codon...
s, including gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
s required for DNA replication
DNA replication
DNA replication is a biological process that occurs in all living organisms and copies their DNA; it is the basis for biological inheritance. The process starts with one double-stranded DNA molecule and produces two identical copies of the molecule...
, transcription and translation, DNA repair
DNA repair
DNA repair refers to a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as UV light and radiation can cause DNA damage, resulting in as many as 1...
, cellular transport, and energy metabolism. It was the second complete bacterial genome ever sequenced, after Haemophilus influenzae
Haemophilus influenzae
Haemophilus influenzae, formerly called Pfeiffer's bacillus or Bacillus influenzae, Gram-negative, rod-shaped bacterium first described in 1892 by Richard Pfeiffer during an influenza pandemic. A member of the Pasteurellaceae family, it is generally aerobic, but can grow as a facultative anaerobe. H...
. The small genome of M. genitalium made it the organism of choice in The Minimal Genome Project, a study to find the smallest set of genetic material necessary to sustain life
Life
Life is a characteristic that distinguishes objects that have signaling and self-sustaining processes from those that do not, either because such functions have ceased , or else because they lack such functions and are classified as inanimate...
.
Symptoms
Various symptoms of infection: An infected person may have some or all symptoms, or may be asymptomatic.- UrethritisUrethritisUrethritis is inflammation of the urethra. The most common symptom is painful or difficult urination.-Causes:The disease is classified as either gonococcal urethritis, caused by Neisseria gonorrhoeae, or non-gonococcal urethritis , most commonly caused by Chlamydia trachomatis...
(in men) - DischargeDischargeDischarge in the context to expel or to "let go" may refer to:* A military discharge, issued when a member of the armed forces is released from service* Termination of employment, the end of an employee's duration with an employer...
(both sexes) - Burning while urinating (both sexes)
- ArthritisArthritisArthritis is a form of joint disorder that involves inflammation of one or more joints....
/reactive arthritisReactive arthritisReactive arthritis , is classified as an autoimmune condition that develops in response to an infection in another part of the body. Coming into contact with bacteria and developing an infection can trigger the disease. Reiter's syndrome has symptoms similar to various other conditions collectively...
(mostly men) - Vaginal itching (women)
- Pain during intercourse (women)
This infection is associated with bacterial vaginosis
Bacterial vaginosis
Bacterial vaginosis or less commonly vaginal bacteriosis is a disease of the vagina caused by bacteria. The U.S. Centers for Disease Control and Prevention states it is not clear what role sexual activity plays in the development. However, it is known that BV is associated with having a new sex...
. In the long term, this infection is suspected to cause pelvic inflammatory disease
Pelvic inflammatory disease
Pelvic inflammatory disease is a generic term for inflammation of the uterus, fallopian tubes, and/or ovaries as it progresses to scar formation with adhesions to nearby tissues and organs. This may lead to infections. PID is a vague term and can refer to viral, fungal, parasitic, though most...
.
Treatment
The CDC recommends using one of these treatments, in this order of prevalence (the first is known to be the most effective, the others are alternative treatments)- AzithromycinAzithromycinAzithromycin is an azalide, a subclass of macrolide antibiotics. Azithromycin is one of the world's best-selling antibiotics...
1 g orally in a single dose - DoxycyclineDoxycyclineDoxycycline INN is a member of the tetracycline antibiotics group, and is commonly used to treat a variety of infections. Doxycycline is a semisynthetic tetracycline invented and clinically developed in the early 1960s by Pfizer Inc. and marketed under the brand name Vibramycin. Vibramycin...
100 mg orally twice a day for 7 days - ErythromycinErythromycinErythromycin is a macrolide antibiotic that has an antimicrobial spectrum similar to or slightly wider than that of penicillin, and is often used for people who have an allergy to penicillins. For respiratory tract infections, it has better coverage of atypical organisms, including mycoplasma and...
base 500 mg orally four times a day for 7 days - Erythromycin ethylsuccinate 800 mg orally four times a day for 7 days
- OfloxacinOfloxacinOfloxacin is a synthetic chemotherapeutic antibiotic of the fluoroquinolone drug class considered to be a second-generation fluoroquinolone. The original brand, Floxin, has been discontinued by the manufacturer in the United States on 18 June 2009, though generic equivalents continue to be...
300 mg orally twice a day for 7 days - LevofloxacinLevofloxacinLevofloxacin is a synthetic chemotherapeutic antibiotic of the fluoroquinolone drug class and is used to treat severe or life-threatening bacterial infections or bacterial infections that have failed to respond to other antibiotic classes. It is sold under various brand names, such as Levaquin and...
500 mg orally once daily for 7 days
However, this study Azithromycin Failure in Mycoplasma genitalium Urethritis says that "...doxycycline
Doxycycline
Doxycycline INN is a member of the tetracycline antibiotics group, and is commonly used to treat a variety of infections. Doxycycline is a semisynthetic tetracycline invented and clinically developed in the early 1960s by Pfizer Inc. and marketed under the brand name Vibramycin. Vibramycin...
and levofloxacin
Levofloxacin
Levofloxacin is a synthetic chemotherapeutic antibiotic of the fluoroquinolone drug class and is used to treat severe or life-threatening bacterial infections or bacterial infections that have failed to respond to other antibiotic classes. It is sold under various brand names, such as Levaquin and...
have substantial failure rates..." and "...Recurrent urethral symptoms following azithromycin therapy only occurred in persons with persistent M. genitalium infection and resolved with moxifloxacin."
So moxifloxacin
Moxifloxacin
Moxifloxacin is a fourth-generation synthetic fluoroquinolone antibacterial agent developed by Bayer AG . It is marketed worldwide under the brand names Avelox, Avalox, and Avelon for oral treatment. In most countries, the drug is also available in parenteral form for intravenous infusion...
appears to be an alternative treatment after one of the other treatments have already failed (Azithromycin
Azithromycin
Azithromycin is an azalide, a subclass of macrolide antibiotics. Azithromycin is one of the world's best-selling antibiotics...
1g is the preferred first-line treatment).
Synthetic life
In October 2007, a team of scientists headed by DNA researcher Craig VenterCraig Venter
John Craig Venter is an American biologist and entrepreneur, most famous for his role in being one of the first to sequence the human genome and for his role in creating the first cell with a synthetic genome in 2010. Venter founded Celera Genomics, The Institute for Genomic Research and the J...
and Nobel laureate Hamilton Smith
Hamilton O. Smith
Hamilton Othanel Smith is an American microbiologist and Nobel laureate.Smith was born on August 23, 1931, and graduated from University Laboratory High School of Urbana, Illinois. He attended the University of Illinois at Urbana-Champaign, but in 1950 transferred to the University of California,...
announced that they plan to create the first artificial life
Artificial life
Artificial life is a field of study and an associated art form which examine systems related to life, its processes, and its evolution through simulations using computer models, robotics, and biochemistry. The discipline was named by Christopher Langton, an American computer scientist, in 1986...
form in history by creating a synthetic chromosome, which they plan to inject into the M. genitalium bacterium, with potential to result in an artificial species dubbed Mycoplasma laboratorium
Mycoplasma laboratorium
Mycoplasma laboratorium is a planned partially synthetic species of bacterium derived from the genome of Mycoplasma genitalium. This effort in synthetic biology is being undertaken at the J. Craig Venter Institute by a team of approximately 20 scientists headed by Nobel laureate Hamilton Smith, and...
or Mycoplasma JCVI-1.0 after the research centre in which it was created, the J. Craig Venter Institute
J. Craig Venter Institute
The J. Craig Venter Institute is a non-profit genomics research institute founded by J. Craig Venter, Ph.D. in October 2006. The Institute was the result of consolidating four organizations: the Center for the Advancement of Genomics, The Institute for Genomic Research, the Institute for...
in the United States.
On 24 January 2008, the same team reported to have synthesized the complete 582,970-base pair genome of M. genitalium (a key gene that enables the wild organism to cause disease was knocked out). The final stage of synthesis was completed inside a M capricolum
Mycoplasma capricolum
Mycoplasma capricolum is a species of Mycoplasma bacteria. It is primarily a pathogen of goats, but has also been found in sheep and cows.-External links:* at MicrobeWiki...
, which had its DNA removed, with the help of yeast cell
Saccharomyces cerevisiae
Saccharomyces cerevisiae is a species of yeast. It is perhaps the most useful yeast, having been instrumental to baking and brewing since ancient times. It is believed that it was originally isolated from the skin of grapes...
s. On 20 May 2010 they reported success with a similar process, using instead the genome of Mycoplasma mycoides, creating what some called the first artificial life.
See also
- The Minimal Genome Project
- Candidatus Carsonella ruddiiCandidatus Carsonella ruddiiCandidatus Carsonella ruddii is an obligate endosymbiotic Gamma Proteobacterium; it has the smallest genome of any characterised bacteria....
- ArthritisArthritisArthritis is a form of joint disorder that involves inflammation of one or more joints....
/ Reactive arthritisReactive arthritisReactive arthritis , is classified as an autoimmune condition that develops in response to an infection in another part of the body. Coming into contact with bacteria and developing an infection can trigger the disease. Reiter's syndrome has symptoms similar to various other conditions collectively...
/ Septic arthritisSeptic arthritisSeptic arthritis is the purulent invasion of a joint by an infectious agent which produces arthritis. People with artificial joints are more at risk than the general population but have slightly different symptoms, are infected with different organisms and require different treatment. Septic...
External links
- Mycoplasma genitalium Reference Work at the UK Health Protection Agency
- Mycoplasma genitalium G-37 genome page