Habitat of Neisseria gonorrhoeae
- Human is only the natural host.
- Found in human urogenital tract.
- Rectal carriage in healthy individuals.
- Typically seen in pus cells (intracellular)
- Found intracellularly in polymorphonuclear leukocytes, or a specific category of white blood cells with varying shapes of nuclei.
What does the name Neisseria mean?
Microbiology
- Antigenic variation. N. ...
- Phase variation. Phase variation is similar to antigenic variation, but instead of changes at the genetic level altering the composition of molecules, these genetic changes result in the turning on ...
- Survival of gonococci. ...
What does Neisseria mean?
Then, what does Neisseria mean? Medical Definition of Neisseria : a genus (the type of the family Neisseriaceae) of parasitic bacteria that grow in pairs and occasionally tetrads, thrive best at 98.6°F (37°C) in the animal body or serum media, and include the gonococcus (N. gonorrhoeae) and meningococcus (N. meningitidis)
Is Neisseria Gram negative or positive?
Neisseria species are gram-negative, oxidase-positive bacteria. All are catalase-positive, except N. bacilliformis and N. elongata. All are diplococci, except N. bacilliformis, N. elongata, and N. weaveri.
How does Neisseria meningitidis attack and spread?
The Neisseria meningitidis bacterium is usually spread through close, personal or prolonged contact with respiratory or oral secretions. Unlike a cold or the flu, the bacteria that cause meningitis cannot be spread by casual contact or by breathing the air where an infected person has been.
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Where does Neisseria grow?
Neisseria spp. grow best aerobically in an atmosphere containing 5–10% carbon dioxide at a temperature of 89.6–98.6°F (32–37°C) and a pH of 7–7.5. Cell size ranges from 0.6 to 1.5 mm depending upon the species source of the isolate and the age of the culture.
Where does Neisseria come from?
History. The genus Neisseria is named after the German bacteriologist Albert Neisser, who in 1879 discovered its first example, Neisseria gonorrhoeae, the pathogen which causes the human disease gonorrhea.
What does Neisseria grow on?
The organism grows on different media such as blood agar, trypticase soy agar, supplemented chocolate agar, and Mueller-Hinton agar. Fig. 3 Neisseria meningitidis - blood agar culture.
How do you get Neisseria?
Meningococcal disease is caused by bacteria called Neisseria meningitidis. People with meningococcal disease spread the bacteria to others through close personal contact such as living together or kissing. A person with meningococcal disease needs immediate medical attention.
Can Neisseria be found in soil?
The family Enterobacteriaceae comprises a large heterogeneous group of Gram-negative, nonspore-forming facultative anaerobes; they are among the most important human pathogens. They are widely distributed in soil and plants and are colonizers of the gastrointestinal tract of humans and animals.
Where can Neisseria gonorrhoeae be found?
The most common site of Neisseria gonorrhoeae infection is the urogenital tract. Men with this infection may experience dysuria with penile discharge, and women may have mild vaginal mucopurulent discharge, severe pelvic pain, or no symptoms.
Does Neisseria grow on Mac?
Note: Neisseria does not grow on MacConkey. Note: Growth, but no fermentation of lactose. Colorless colonies, medium is slightly yellow due to the increased pH resulting from bacterial digestion of peptone in the medium. Note: Gram-positives do not grow on MacConkey.
Where is Neisseria meningitidis found?
N. meningitidis bacteria are found in the nose and throat without causing disease. Most people exposed to N. meningitidis do not become ill.
Does Neisseria grow on chocolate agar?
Chocolate agar is used for growing fastidious respiratory bacteria, such as Haemophilus influenzae and Neisseria meningitidis.
How do u know if u have clap?
If they do get symptoms, the most common include:pain when urinating.unusual vaginal discharge.pain in the tummy or pelvis.pain during sex.bleeding after sex.bleeding between periods.
What STD causes open sores?
Chancroid is a sexually transmitted infection (STI) caused by bacteria. It causes painful open sores (ulcers) in the genital area and swelling of the lymph nodes in the groin.
Can you get gonorrhea from kissing?
It wasn't believed to be, but recent studies have shown that it is actually possible to contract oral gonorrhea from kissing. There's accumulating evidence that kissing might be a common mode of gonorrhea transmission, though just how common requires more research. There's no need to swear off smooching, though.
What is the size of a Neisseria spp.?
Neisseria spp. are a Gram-negative non-spore-forming diplococcus that has a flattened shape; its size ranges between 0.6–0.8 μm. They are oxidase-positive, non-acid-fast cocci or plump rods. They can reach a diameter of around 0.6–0.8 μm and sometimes up to 1.0 × 2.0–3.0 μm. The cocci often occur in pairs with adjacent sides flattened, giving them a typical kidney-bean shape. They are non-motile aerobes and some are microaerophilic or facultative anaerobes. They are non-halophilic; some have an optimal growth temperature of around 37°C. They need blood or ascitic fluid for growth as well as increased carbon dioxide pressure. Neisseria spp. have a very well-advanced functioning tricarboxylic acid cycle with the ability to use Enter–Doudoroff and pentose shunt. The Embden–Meyerhof (EM) enzymes are present, but this pathway is not extensively used and probably not used at all in aerobic conditions. Fermentation of sugars will mainly result in acid formation from glucose; however, some strains have the ability to produce acids from other sugars.
What temperature does Neisseria grow?
Neisseria spp. grow best aerobically in an atmosphere containing 5–10% carbon dioxide at a temperature of 89.6–98.6°F (32–37°C) and a pH of 7–7.5. Cell size ranges from 0.6 to 1.5 mm depending upon the species source of the isolate and the age of the culture.
What type of plasmid does a gonococcus carry?
Many gonococci possess a 24.5-mDa conjugative plasmid and can thereby conjugally transfer other non–self-transferable plasmids with high efficiency; chromosomal genes are not mobilized. Many gonococci carry a plasmid (Pc r) that specifies production of a TEM-1 type of β-lactamase (penicillinase). The two most common Pc r plasmids have molecular weights of 3.2 and 4.4 mDa and are closely related to each other and to similar plasmids found in certain Haemophilus spp., including Haemophilus ducreyi. In fact, it is suspected that gonococci first acquired Pc r plasmids from H. ducreyi.28 Pc r plasmids are commonly mobilized to other gonococci by the conjugative plasmid.
Why do Neisseria produce endotoxins?
Some Neisseria produce endotoxins due to the presence of lipo-oligosaccharides and proteins in their outer membranes.
Which colony is larger, N. meningitidis or N. mucosa?
Colonies of N. meningitidis are usually larger (1–2 mm) and flatter. Colonies of the nonpathogenic Neisseria spp. are similar in size, appearance and consistency, except for the saccharolytic Neisseria spp. ( N. subflava, N. sicca and N. mucosa) that are larger (1–3 mm), more convex and smooth ( N. mucosa ).
Is N. meningitidis a bacterium?
N. meningitidis is a common commensal organism of the human nasopharnyx; it has not as yet been isolated from animals or environmental sources. This bacterium is fastidious: optimal growth takes place in a moist environment with temperatures between 35 and 37°C in an atmosphere of around 5–10% carbon dioxide.
Is Neisseria a transformable organism?
Neisseria. Neisseria are naturally highly transformable bacteria, having the ability to take up extracellular DNA efficiently, and incorporate it into the chromosome by homologous recombination [172]. From: Molecular Medical Microbiology (Second Edition), 2015.
What are the two most clinically significant members of the Neisseria genus?
The two most clinically significant members of the genus Neisseria are N. gonorrhoeae (gonococcus) and N. meningitidis (meningococcus). Infection by N. gonorrhoeae is referred to as a gonococcal infection and is transmitted by intimate contact with the mucous membranes. In infected males, the disease is characterized by urethritis with a urethral pus discharge; if left untreated, resulting complications such as prostatitis and periurethral abscess may occur. Females with gonorrhea exhibit vaginal discharge (cervicitis or vulvovaginitis) with accompanying abdominal pain and nonmenstrual bleeding. As with most other sexually transmitted diseases, gonorrhea is prevalent in young adult and homosexual populations. N. gonorrhoeae is sensitive to antibiotics; the common association with chlamydial infection dictates using a therapeutic regimen of cephalosporin (ceftriaxone) and a tetracycline or quinolone to kill organisms. If left untreated, N. gonorrhoeae can cause meningitis with septicemia and resulting arthritis and acute endocarditis upon further dissemination of organisms.
What is the size of a Neisseria spp.?
Neisseria spp. are a Gram-negative non-spore-forming diplococcus that has a flattened shape; its size ranges between 0.6–0.8 μm. They are oxidase-positive, non-acid-fast cocci or plump rods. They can reach a diameter of around 0.6–0.8 μm and sometimes up to 1.0 × 2.0–3.0 μm. The cocci often occur in pairs with adjacent sides flattened, giving them a typical kidney-bean shape. They are non-motile aerobes and some are microaerophilic or facultative anaerobes. They are non-halophilic; some have an optimal growth temperature of around 37°C. They need blood or ascitic fluid for growth as well as increased carbon dioxide pressure. Neisseria spp. have a very well-advanced functioning tricarboxylic acid cycle with the ability to use Enter–Doudoroff and pentose shunt. The Embden–Meyerhof (EM) enzymes are present, but this pathway is not extensively used and probably not used at all in aerobic conditions. Fermentation of sugars will mainly result in acid formation from glucose; however, some strains have the ability to produce acids from other sugars.
Why do Neisseria cells express opacity proteins?
Pathogenic Neisseria express another surface-exposed class of outer membrane proteins that are called opacity proteins (Opa) because their expression leads to distinctive changes in the translucency of the colonies on agar. In the gonococcus, there are about a dozen opa genes while in the meningococcus there are usually four. The expression of Opa protein can turn off and on at high frequency because all of the opa genes have a variable number of pentameric repeats of the sequence CTCTT between the ATG initiation codon and the remainder of the protein that is subject to rapid change due to slipped strand mispairing during replication. Thus, the expression of this class of proteins is controlled at the level of protein translation. Gonococci freshly isolated from the blood of patients with disseminated gonococcal infection do not express Opa. The same is true of isolates from PID. Strains from males with genitourinary disease usually express Opa protein. Most remarkably, in young women not on the pill, the gonococci that can be isolated from the cervix vary so that at the time of ovulation the isolates express Opa, while at the time of menses they do not. This mechanism of translational mechanism for variation has now been seen with other neisserial antigens and is also seen in a number of other mucosal pathogens, notably H. influenzae and Helicobacter pylori. Many different opa genes have been sequenced and have been distinguished either by naming them opaA – opaJ or by adding a numerical subscript (see Table 3 ). The mature proteins coded by these loci are all about 250 amino acids in length. The genes are highly homologous except for two regions that are highly variable and a smaller region that has lesser variation. Gonococi have about 12 opa loci while meningococci have 3 to 4. The differences between the proteins in the content of basic amino acids is noteworthy and the pI of the proteins range from about 7.0 to 10.0.
What temperature does Neisseria grow?
Neisseria spp. grow best aerobically in an atmosphere containing 5–10% carbon dioxide at a temperature of 89.6–98.6°F (32–37°C) and a pH of 7–7.5. Cell size ranges from 0.6 to 1.5 mm depending upon the species source of the isolate and the age of the culture.
Why do Neisseria produce endotoxins?
Some Neisseria produce endotoxins due to the presence of lipo-oligosaccharides and proteins in their outer membranes.
Which colony is larger, N. meningitidis or N. mucosa?
Colonies of N. meningitidis are usually larger (1–2 mm) and flatter. Colonies of the nonpathogenic Neisseria spp. are similar in size, appearance and consistency, except for the saccharolytic Neisseria spp. ( N. subflava, N. sicca and N. mucosa) that are larger (1–3 mm), more convex and smooth ( N. mucosa ).
Does N. meningitidis need oxygen?
N. meningitidis has a strict requirement for oxygen, and in low oxygen (microaerobic) conditions can supplement growth using a truncated denitrification pathway, using nitrogen compounds as electron acceptors ( Rock et al., 2005) ( Fig. 27.1 ). Neisseria sp. have the ability to reduce nitrite (via nitric oxide) to nitrous oxide.
How is N. meningitidis spread?
meningitidis is spread through saliva and respiratory secretions during coughing, sneezing, kissing, chewing on toys and even through sharing a source of fresh water. It has also been reported to be transmitted through oral sex and cause urethritis in men.
How long does it take for N. meningitidis to infect the bloodstream?
The incubation period is short, from 2 to 10 days. In susceptible individuals, N. meningitidis may invade the bloodstream and cause a systemic infection, sepsis, disseminated intravascular coagulation, breakdown of circulation, and septic shock .
What is the bacterial name for meningococcus?
Binomial name. Neisseria meningitidis. Albrecht & Ghon 1901. Neisseria meningitidis, often referred to as meningococcus, is a Gram-negative bacterium that can cause meningitis and other forms of meningococcal disease such as meningococcemia, a life-threatening sepsis. The bacterium is referred to as a coccus because it is round, ...
What is the scale bar of a bacterium?
The scale bar corresponds to 1 µm. Neisseria meningitidis, often referred to as meningococcus, is a Gram-negative bacterium that can cause meningitis and other forms of meningococcal disease such as meningococcemia, a life-threatening sepsis. The bacterium is referred to as a coccus because it is round, and more specifically, ...
Why is a bacterium called a coccus?
The bacterium is referred to as a coccus because it is round, and more specifically, a diplococcus because of its tendency to form pairs. About 10% of adults are carriers of the bacteria in their nasopharynx.
Is N. meningitidis a diplococcus?
N. meningitidis is a Gram-negative diplococcus since it has an outer and inner membranes with a thin layer of peptidoglycan in between. It is 0.6–1.0 micrometers in size. It tests positive for the enzyme cytochrome c oxidase.
Who first observed the bacterium inside cells in the cerebral spinal fluid?
In 1884 Ettore Marchiafava and Angelo Celli first observed the bacterium inside cells in the cerebral spinal fluid (CSF). In 1887 Anton Weichselbaum isolated the bacterium from the CSF of patients with bacterial meningitis. He named the bacterium Diplococcus intracellularis meningitidis.
What is the cell envelope of gram negative bacteria?
Cell Envelope. In gram-negative bacteria, such as N. meningitidis, the subcapsular cell envelope consists of an outer membrane (OM), a peptidoglycan layer, and a cytoplasmic or inner membrane (Fig. 1).
How old are meningococcus?
The meningococcus remains a common cause of bacterial meningitis in children and young adults in the USA (132), now mostly affecting children less than 2 years of age (102, 133). Two-thirds of meningococcal disease in the first year of life in the US occurs in infants less than 6 months of age (134).
When was meningitis first described?
Epidemics of meningococcal meningitis were first described during the early nineteenth century, in 1805 in Geneva, Switzerland by Vieusseux (2), in 1806 in New Bedford, Massachusetts by Danielson and Mann (3) and in the early 1900s in the African meningitis belt (4).
Is N. meningitidisis a gram negative bacterium?
N. meningitidisis a gram-negative β proteobacterium and member of the bacterial family of Neisseriaceae. N. meningitidisis a fastidious bacterium, dying within hours on inanimate surfaces, and is either an encapsulated or unencapsulated, aerobic diplococcus with a “kidney” or “coffee-bean” shape (Fig. 2).
What is meningococcal disease?
Meningococcal disease is caused by bacteria called Neisseria meningitidis. People with meningococcal disease spread the bacteria to others through close personal contact such as living together or kissing. A person with meningococcal disease needs immediate medical attention.
Who is at risk?
Anyone can get meningococcal disease, but people who live or travel to certain areas of the world are more likely to get it.
What can travelers do to prevent meningococcal disease?
Getting a meningococcal vaccine is the best way to protect against meningococcal disease. There are two types of meningococcal vaccines available in the United States:
What is the name of the bacteria that causes a multitude of illnesses?
It is a human-specific bacterium that causes a multitude of illnesses, collectively termed meningococcal disease . Surprisingly, up to 10% of the general population carry the bacteria in their nose and throat without any adverse effects.[2] . Neisseria meningitidis is associated with many infections.
What are the diseases caused by N. meningitidis?
Other infections that N. meningitidis can cause are meningococcemia (defined as a blood infection due to N. meningitidis), pneumonia, septic arthritis, pericarditis, and urethritis. N. meningitidiscan also cause both endemic and epidemic infections and can even infect young, healthy adults. Epidemiology.
What should an infectious disease nurse do?
The infectious disease nurse should educate patients about vaccination. Vaccination is the best strategy in preventing disease, especially in at-risk populations. Due to new vaccinations recently introduced worldwide, the overall burden of meningococcal infection has diminished.
What is the main serotype in Europe?
Serotypes B and C are the main serotypes in Europe and the Americas and serotype Y, generally causing infection in the United States and Canada. Serotype W is the cause of epidemic outbreaks around the world and had an association with the Hajj pilgrimages to Saudi Arabia.
What are the mechanisms of N. meningitidis?
These include phase variation (alteration in protein expression), antigenic variation (altering surface proteins), and molecular mimicry to help it survive the immune response. [7][9]
Can colonization of the nasopharynx cause infection?
Humans so colonized may be asymptomatic carriers. Colonizing the nasopharynx puts close contacts, such as family members, college roommates, and military recruits at an increased risk of contracting N. meningitidis and possible infection.
Overview
Neisseria is a large genus of bacteria that colonize the mucosal surfaces of many animals. Of the 11 species that colonize humans, only two are pathogens, N. meningitidis and N. gonorrhoeae. Most gonococcal infections are asymptomatic and self-resolving, and epidemic strains of the meningococcus may be carried in >95% of a population where systemic disease occurs at <1% prevalence.
Pathogenesis and classification
Species of this genus (family Neisseriaceae) of parasitic bacteria grow in pairs and occasionally tetrads, and thrive best at 98.6 °F (37 °C) in the animal body or serum media.
The genus includes:
• N. gonorrhoeae (also called the gonococcus) causes gonorrhea.
Biochemical identification
All the medically significant species of Neisseria are positive for both catalase and oxidase. Different Neisseria species can be identified by the sets of sugars from which they will produce acid. For example, N. gonorrhoeae makes acid from only glucose, but N. meningitidis produces acid from both glucose and maltose.
Polysaccharide capsule. N. meningitidis has a polysaccharide capsule that surrounds the outer …
History
The genus Neisseria is named after the German bacteriologist Albert Neisser, who in 1879 discovered its first example, Neisseria gonorrhoeae, the pathogen which causes the human disease gonorrhea. Neisser also co-discovered the pathogen that causes leprosy, Mycobacterium leprae. These discoveries were made possible by the development of new staining techniques which he helped to develop.
Genomes
The genomes of at least 10 Neisseria species have been completely sequenced. The best-studied species are N. meningitidis with more than 70 strains and N. gonorrhoeae with at least 10 strains completely sequenced. Other complete genomes are available for N. elongata, N. lactamica, and N. weaveri. Whole genome shotgun sequences are available for hundreds of other species and strains. N. meningitidis encodes 2,440 to 2,854 proteins while N. gonorrhoeae encodes from 2,60…
Vaccine
Diseases caused by N. meningitidis and N. gonorrhoeae are significant health problems worldwide, the control of which is largely dependent on the availability and widespread use of comprehensive meningococcal and gonococcal vaccines. Development of neisserial vaccines has been challenging due to the nature of these organisms, in particular the heterogeneity, variability and/or poor immunogenicity of their outer surface components. As strictly human pathogens, they are hi…
Antibiotic resistance
The acquisition of cephalosporin resistance in N. gonorrhoeae, particularly ceftriaxone resistance, has greatly complicated the treatment of gonorrhea, with the gonococcus now being classified as a "superbug".
Genetic transformation
Genetic transformation is the process by which a recipient bacterial cell takes up DNA from a neighboring cell and integrates this DNA into the recipient’s genome by recombination. In N. meningitidis and N. gonorrhoeae, DNA transformation requires the presence of short DNA sequences (9-10 monomers residing in coding regions) of the donor DNA. These sequences are called DNA uptake sequences (DUSs). Specific recognition of DUSs is mediated by a type IV pilin…