''Shigella sonnei'' is a species of ''

Shigella ''Shigella'' is a genus of bacteria that is Gram-negative, facultative anaerobic, non-spore-forming, nonmotile, rod-shaped, and genetically closely related to '' E. coli''. The genus is named after Kiyoshi Shiga, who first discovered it in 1 ...

''. Together with ''

Shigella flexneri ''Shigella flexneri'' is a species of Gram-negative bacteria in the genus ''Shigella'' that can cause diarrhea in humans. Several different serogroups of ''Shigella'' are described; ''S. flexneri'' belongs to group ''B''. ''S. flexneri'' infecti ...

'', it is responsible for 90% of

shigellosis Shigellosis is an infection of the intestines caused by ''Shigella'' bacteria. Symptoms generally start one to two days after exposure and include diarrhea, fever, abdominal pain, and feeling the need to pass stools even when the bowels are emp ...

cases. ''Shigella sonnei'' is named for the Danish bacteriologist Carl Olaf Sonne. It is a

Gram-negative Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wall ...

rod-shaped A bacillus (), also called a bacilliform bacterium or often just a rod (when the context makes the sense clear), is a rod-shaped bacterium or archaeon. Bacilli are found in many different taxonomic groups of bacteria. However, the name ''Bacillu ...

, nonmotile, non-spore-forming bacterium.

Pathophysiology

This species

polymerizes In polymer chemistry, polymerization (American English), or polymerisation (British English), is a process of reacting monomer molecules together in a chemical reaction to form polymer chains or three-dimensional networks. There are many for ...

host cell

actin Actin is a family of globular multi-functional proteins that form microfilaments in the cytoskeleton, and the thin filaments in muscle fibrils. It is found in essentially all eukaryotic cells, where it may be present at a concentration of over ...

Evolution

This species is clonal and has spread worldwide. Analysis of 132 strains has shown that they originated from a common ancestor in Europe around 1500 AD.

Causes

"Group D" ''

'' bacteria cause

. Those infected with the bacteria release it into their stool, thus causing possibility of spread through food or water, or from direct contact to a person orally. Having poorly sanitized living conditions or contaminated food or water contributes to contracting the disease.

People at risk

Infants and toddlers, the elderly, and people living with chronic health conditions are all susceptible to the most severe symptoms of ''S. sonnei'' disease. Shigellosis is commonly suffered by individuals with advanced HIV disease, as well as men who have sex with men, regardless of their HIV status. Shigellosis may invade the bloodstream and cause bacteremia in people with a compromised immune system, which can be life-threatening.

Symptoms

Infections can result in acute

fever Fever, also referred to as pyrexia, is defined as having a body temperature, temperature above the human body temperature, normal range due to an increase in the body's temperature Human body temperature#Fever, set point. There is not a single ...

, acute abdominal

cramping A cramp is a sudden, involuntary, painful skeletal muscle contraction or overshortening associated with electrical activity; while generally temporary and non-damaging, they can cause significant pain and a paralysis-like immobility of the aff ...

, cramping

rectal pain Rectal pain is the symptom of pain in the area of the rectum. A number of different causes (68) have been documented. Differential diagnosis Anal fissures One of the most common causes of rectal pain is an anal fissure. It involves a tear in th ...

, nausea, watery

diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin wi ...

, or blood,

mucus Mucus ( ) is a slippery aqueous secretion produced by, and covering, mucous membranes. It is typically produced from cells found in mucous glands, although it may also originate from mixed glands, which contain both serous and mucous cells. It is ...

, or

pus Pus is an exudate, typically white-yellow, yellow, or yellow-brown, formed at the site of inflammation during bacterial or fungal infection. An accumulation of pus in an enclosed tissue space is known as an abscess, whereas a visible collection ...

in the stool, which may occur within 1–7 days after coming in contact with the bacteria. Most ''Shigella'' infection usually clears up without complications, but if left untreated or delay in diagnosis may lead to some serious complication such as dehydration (especially severe dehydration can lead to shock and death), seizure, hemolytic uremic syndrome (HUS), toxic megacolon, and reactive arthritis. Persons with diarrhea usually recover completely, although it may be several months before their bowel habits are entirely normal. Once someone has had shigellosis, they are not likely to get infected with that specific type again for at least several years. However, they can still get infected with other types of ''Shigella''.

Possible complications

Dehydration In physiology, dehydration is a lack of total body water, with an accompanying disruption of metabolic processes. It occurs when free water loss exceeds free water intake, usually due to exercise, disease, or high environmental temperature. Mil ...

Seizure An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with los ...

s occur most often in children, although how ''Shigella'' causes this complications is unknown. *

Bloodstream infection Bloodstream infections (BSIs), which include bacteremias when the Bacterial infection, infections are bacterial and fungemias when the Mycosis, infections are fungal, are infections present in the blood. Blood is normally a Asepsis, sterile envi ...

s may occur from ''Shigella''. *

Rectal prolapse A rectal prolapse occurs when walls of the rectum have prolapsed to such a degree that they protrude out of the anus and are visible outside the body. However, most researchers agree that there are 3 to 5 different types of rectal prolapse, depend ...

can occur while straining during bowel movements. *

Toxic megacolon Toxic megacolon is an acute form of colonic distension. It is characterized by a very dilated colon (megacolon), accompanied by abdominal distension (bloating), and sometimes fever, abdominal pain, or shock. Toxic megacolon is usually a complica ...

paralyzes bowel movements or causes passing gas. *

Reactive arthritis Reactive arthritis, also known as Reiter's syndrome, is a form of inflammatory arthritis that develops in response to an infection in another part of the body (cross-reactivity). Coming into contact with bacteria and developing an infection can ...

, which is the inflammation of joints * Hemolytic-uremic syndrome (HUS) is a complication that occurs when bacteria enter the digestive system and produce toxins to destroy red blood cells that may cause

bloody diarrhea Dysentery (UK pronunciation: , US: ), historically known as the bloody flux, is a type of gastroenteritis that results in bloody diarrhea. Other symptoms may include fever, abdominal pain, and a feeling of incomplete defecation. Complications ...

as a symptom.

Prevention

vaccine A vaccine is a biological Dosage form, preparation that provides active acquired immunity to a particular infectious disease, infectious or cancer, malignant disease. The safety and effectiveness of vaccines has been widely studied and verifie ...

s are available for ''Shigella''. The best prevention against shigellosis is thorough, frequent, and cautious handwashing with soap and water before and after using the washroom and before handling food; also, a strict adherence to standard food and water safety precautions is important. Avoid having sexual intercourse with those people who have diarrhea or who recently recovered from diarrhea. It is also important to avoid swallowing water from ponds, lakes, or untreated swimming pools.

Treatment

Antibiotic resistance Antimicrobial resistance (AMR) occurs when microbes evolve mechanisms that protect them from the effects of antimicrobials. All classes of microbes can evolve resistance. Fungi evolve antifungal resistance. Viruses evolve antiviral resistance. ...

has been reported.

Growth in lab

It can be grown on MAC agar and TSA, at 37 °C optimally, but it also grows at 25 °C. It is

facultatively anaerobic A facultative anaerobic organism is an organism that makes ATP by aerobic respiration if oxygen is present, but is capable of switching to fermentation if oxygen is absent. Some examples of facultatively anaerobic bacteria are ''Staphylococcus' ...

and chemo-organotrophic, and produces acid when

carbohydrate In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or ma ...

s are

catabolized Catabolism () is the set of metabolic pathways that breaks down molecules into smaller units that are either oxidized to release energy or used in other anabolic reactions. Catabolism breaks down large molecules (such as polysaccharides, lipids, ...

References

External links

''Shigella sonnei''
a
MicrobeWiki

''Shigella sonnei''
in the NCBI Taxonomy Browser
Type strain of ''Shigella sonnei'' at Bac''Dive'' – the Bacterial Diversity Metadatabase
{{Taxonbar, from=Q6382438 Enterobacteriaceae Bacteria described in 1920