Streptococcus salivarius

Updated : November 12, 2023

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Epidemiology 

The epidemiology of Streptococcus salivarius is the study of the distribution and determinants of the infection and disease caused by this bacterium in human populations. According to the web search results, some epidemiological aspects of S. salivarius are: 

  • S. salivarius is a typical inhabitant In the human upper respiratory tract and oral cavity, where it is usually harmless and may even have some beneficial effects as a probiotic. 
  • S. salivarius is an opportunistic pathogen. It may result in bloodstream infections or other organs, especially in people with weakened immune systems or predisposing local factors such as mucosal disruption or underlying severe diseases. 
  • S. salivarius infections are rare and often associated with endocarditis, meningitis, septic arthritis, osteomyelitis, or abscesses. The mortality rate of S. salivarius bacteremia is estimated to be around 20%. 
  • S. salivarius is transmitted by direct contact with saliva or respiratory secretions of infected or colonized individuals. There is no evidence of animal or environmental reservoirs for this bacterium. 
  • S. salivarius has a worldwide distribution and affects people of all ages and genders. However, there is limited data on the prevalence and incidence of S. salivarius infections in different regions and populations. 

Classification and Structure 

Kingdom: Bacteria 

Phylum: Bacillota 

Class: Bacilli 

Order: Lactobacillales 

Family: Streptococcaceae 

Genus: Streptococcus 

Species:S. salivarius 

Spherical, gram-positive, facultatively anaerobic, catalase, and oxidase-negative, Streptococcus salivarius is a bacterium. It possesses a thick peptidoglycan coating in its cell wall and can form chains or pairs of cells. It lacks spores, flagella, and a capsule. Bacteriocins, which are proteins that stop other bacteria from growing, can be produced by it. Lactic acid can also be produced through the fermentation of carbohydrates like sucrose and glucose. 

Antigenic Types 

Antigenic types of Streptococcus salivarius are based on the type-specific capsular polysaccharides the bacteria produce. According to one source, at least 12 antigenic types of S. salivarius are designated as I to XI and XII. However, another source suggests that there are only ten antigenic types of S. salivarius and that types XI and XII are variants of types I and II, respectively. The antigenic types of S. salivarius are different from the serotypes of other streptococci, such as Streptococcus agalactiae (group B streptococcus), based on type-specific cell wall proteins. The antigenic types of S. salivarius may have implications for some strains’ bacteriocin production and probiotic potential. 

  • S. salivarius K12: This strain is a bacteriocin producer, which means it can produce substances that impede the development of dangerous germs, such as Streptococcus pyogenes, which causes strep throat. This strain has been used as a probiotic to prevent or reduce the severity of strep throat and other upper respiratory infections. 
  • S. salivarius M18: This strain is also a bacteriocin producer, but it has a different spectrum of activity than K12. It can inhibit bacteria associated with halitosis (bad breath), such as Fusobacterium nucleatum and Porphyromonas gingivalis. It can also produce enzymes that help break down dental plaque and prevent tooth decay. 
  • S. salivarius TOVE-R: This strain is another bacteriocin producer that can inhibit Streptococcus pyogenes and other pathogens. It has been shown to reduce the incidence of rheumatic fever, a complication of strep throat, in children. 

Pathogenesis 

The pathogenesis of Streptococcus salivarius is not well understood, but some factors that may contribute to its virulence are: 

  • The ability to produce bacteriocins, which are antimicrobial peptides that can inhibit the growth of other bacteria, including potential competitors or pathogens. 
  • The ability to form biofilms, communities of bacteria that adhere to surfaces and are protected by a matrix of extracellular substances. Biofilms can enhance bacterial survival and resistance to antibiotics and host defenses. 
  • possessing the capacity to cling to and infiltrate host cells, such as epithelial or endothelial cells, using various surface proteins and enzymes. It can facilitate bacterial dissemination and tissue damage. 
  • The ability to modulate host immune responses by inducing inflammation or suppressing immune cell activation. It can affect the balance between bacterial clearance and host tissue injury. 

Host Defenses 

Host defenses of Streptococcus salivarius are the mechanisms by which the human body protects itself from infections caused by this bacterium. Streptococcus salivarius is a typical inhabitant In the upper respiratory tract and mouth cavity in humans, and it usually does not cause any harm to healthy people. However, it can become an opportunistic pathogen and cause infections in different body parts under certain conditions. Some of the host defenses of Streptococcus salivarius are: 

  • The innate immune system: This is the first line of defense that recognizes and responds to external invaders like fungi, viruses, and bacteria. Physical barriers like the skin & mucous membranes make up the innate immune system. Cellular components include macrophages, neutrophils, natural killer cells, and complement proteins. These cells and molecules can kill or inhibit the growth of Streptococcus salivarius by phagocytosis (engulfing and digesting), oxidative burst (producing reactive oxygen species), antimicrobial peptides (destroying the bacterial cell wall or membrane), or opsonization (coating the bacteria with antibodies or complement proteins to facilitate phagocytosis). 
  • The adaptive immune system: This is the second line of defense that develops a specific and long-lasting response to foreign invaders, such as bacteria, viruses, and fungi. There are two types of lymphocytes in the adaptive immune system: B and T cells. B cells produce antibodies that bind to specific antigens (molecules that trigger an immune response) on Streptococcus salivarius’s surface and neutralize or identify them so that other immune cells can destroy them. a T cell can help B cells produce antibodies or directly kill infected cells by releasing cytotoxic molecules. 
  • The oral microbiota: This is the community of microorganisms that live in the oral cavity and interact with each other and the host. The oral microbiota can prevent or limit the colonization and infection of Streptococcus salivarius by competing for nutrients and space, producing inhibitory substances, such as bacteriocins (proteins that kill or inhibit other bacteria), or modulating the host immune system. 

These are some of the host defenses of Streptococcus salivarius, but there may be more that are not yet known or understood. 

Clinical manifestations 

Streptococcus salivarius is a type of bacteria that usually lives in the oral cavity and upper respiratory tract of humans. It is usually harmless but can sometimes cause infections in certain conditions. Some of the clinical manifestations of Streptococcus salivarius infections are: 

  • Bacteremia is a condition where bacteria enter the bloodstream and cause symptoms such as fever, chills, and low blood pressure. It can happen after dental procedures or tooth brushing that cause trauma to the oral mucosa. 
  • Endocarditis: This is an infection of the interior of the heart chambers or the heart valves. It can cause heart murmurs, chest pain, shortness of breath, and fatigue. It can also lead to complications such as heart failure or stroke. It can occur in people who have pre-existing heart defects or damage. 
  • Meningitis is an inflammation of the membranes that surround the brain and spinal cord. It can cause headaches, stiff neck, fever, confusion, and seizures. It can also result in brain damage or death. It can occur in people with weakened immune systems or head injuries. 
  • Pharyngitis: This is an inflammation of the throat that causes sore throat, difficulty swallowing, and swollen lymph nodes. Additionally, it may result in a skin rash or the soft palate (the area at the back of the roof of the mouth). It can occur in people exposed to someone with strep throat caused by a different species of Streptococcus (Streptococcus pyogenes). 
  • Skin infections: These are infections of the skin that cause red, raised, and painful lesions with distinct margins. They can also cause pus-filled blisters or ulcers. These can occur in people with skin injuries or wounds contaminated by the bacteria. 

These are some possible clinical manifestations of Streptococcus salivarius infections, but they are uncommon. Most people with this bacterium in their mouth or throat do not develop any symptoms or problems. 

Diagnosis 

The diagnosis of Streptococcus salivarius is based on the following steps: 

  • Clinical examination and history: The doctor will ask about the patient’s symptoms, medical history, and risk factors. The symptoms may include fever, swollen/aching limbs, hyperactivity, depression, ataxia, paresis, seizures, paralysis, or signs of endocarditis, meningitis, septic arthritis, osteomyelitis, or abscesses. 
  • Blood culture: The doctor will collect and deliver a lab to analyse a sample of blood. The blood culture will show if there is any bacterial growth in the blood. S. salivarius can be identified by its morphology, biochemical characteristics, and molecular methods. 
  • Other tests: Depending on the site and severity of the infection, the doctor may order other investigations to assess the injury’s severity and 
  • validate the diagnosis. These tests may include urine culture, cerebrospinal fluid (CSF) analysis, echocardiography, magnetic resonance imaging (MRI), computed tomography (CT) scan, or biopsy. 

Control 

Streptococcus salivarius is a typical inhabitant of the oral cavity and upper respiratory tract, and it usually does not cause any harm to healthy people. However, there are some ways to prevent infections caused by this bacterium, especially in people at risk of developing complications. Some of the preventive measures are: 

  • Good oral hygiene: Brush teeth 2x/a day, floss, and use mouthwash to reduce bacteria and prevent dental issues. 
  • Don’t share food/drink: Avoid sharing utensils with people having oral infections to prevent bacterial transmission. 
  • Probiotics: Take Streptococcus salivarius K12 probiotics to prevent or reduce strep throat and respiratory infections potentially. 
  • Seek medical attention: If experiencing strep throat symptoms (sore throat, fever, etc.), see a doctor for diagnosis and antibiotics to avoid complications. 
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Streptococcus salivarius

Updated : November 12, 2023

Mail Whatsapp PDF Image



Epidemiology 

The epidemiology of Streptococcus salivarius is the study of the distribution and determinants of the infection and disease caused by this bacterium in human populations. According to the web search results, some epidemiological aspects of S. salivarius are: 

  • S. salivarius is a typical inhabitant In the human upper respiratory tract and oral cavity, where it is usually harmless and may even have some beneficial effects as a probiotic. 
  • S. salivarius is an opportunistic pathogen. It may result in bloodstream infections or other organs, especially in people with weakened immune systems or predisposing local factors such as mucosal disruption or underlying severe diseases. 
  • S. salivarius infections are rare and often associated with endocarditis, meningitis, septic arthritis, osteomyelitis, or abscesses. The mortality rate of S. salivarius bacteremia is estimated to be around 20%. 
  • S. salivarius is transmitted by direct contact with saliva or respiratory secretions of infected or colonized individuals. There is no evidence of animal or environmental reservoirs for this bacterium. 
  • S. salivarius has a worldwide distribution and affects people of all ages and genders. However, there is limited data on the prevalence and incidence of S. salivarius infections in different regions and populations. 

Classification and Structure 

Kingdom: Bacteria 

Phylum: Bacillota 

Class: Bacilli 

Order: Lactobacillales 

Family: Streptococcaceae 

Genus: Streptococcus 

Species:S. salivarius 

Spherical, gram-positive, facultatively anaerobic, catalase, and oxidase-negative, Streptococcus salivarius is a bacterium. It possesses a thick peptidoglycan coating in its cell wall and can form chains or pairs of cells. It lacks spores, flagella, and a capsule. Bacteriocins, which are proteins that stop other bacteria from growing, can be produced by it. Lactic acid can also be produced through the fermentation of carbohydrates like sucrose and glucose. 

Antigenic Types 

Antigenic types of Streptococcus salivarius are based on the type-specific capsular polysaccharides the bacteria produce. According to one source, at least 12 antigenic types of S. salivarius are designated as I to XI and XII. However, another source suggests that there are only ten antigenic types of S. salivarius and that types XI and XII are variants of types I and II, respectively. The antigenic types of S. salivarius are different from the serotypes of other streptococci, such as Streptococcus agalactiae (group B streptococcus), based on type-specific cell wall proteins. The antigenic types of S. salivarius may have implications for some strains’ bacteriocin production and probiotic potential. 

  • S. salivarius K12: This strain is a bacteriocin producer, which means it can produce substances that impede the development of dangerous germs, such as Streptococcus pyogenes, which causes strep throat. This strain has been used as a probiotic to prevent or reduce the severity of strep throat and other upper respiratory infections. 
  • S. salivarius M18: This strain is also a bacteriocin producer, but it has a different spectrum of activity than K12. It can inhibit bacteria associated with halitosis (bad breath), such as Fusobacterium nucleatum and Porphyromonas gingivalis. It can also produce enzymes that help break down dental plaque and prevent tooth decay. 
  • S. salivarius TOVE-R: This strain is another bacteriocin producer that can inhibit Streptococcus pyogenes and other pathogens. It has been shown to reduce the incidence of rheumatic fever, a complication of strep throat, in children. 

Pathogenesis 

The pathogenesis of Streptococcus salivarius is not well understood, but some factors that may contribute to its virulence are: 

  • The ability to produce bacteriocins, which are antimicrobial peptides that can inhibit the growth of other bacteria, including potential competitors or pathogens. 
  • The ability to form biofilms, communities of bacteria that adhere to surfaces and are protected by a matrix of extracellular substances. Biofilms can enhance bacterial survival and resistance to antibiotics and host defenses. 
  • possessing the capacity to cling to and infiltrate host cells, such as epithelial or endothelial cells, using various surface proteins and enzymes. It can facilitate bacterial dissemination and tissue damage. 
  • The ability to modulate host immune responses by inducing inflammation or suppressing immune cell activation. It can affect the balance between bacterial clearance and host tissue injury. 

Host Defenses 

Host defenses of Streptococcus salivarius are the mechanisms by which the human body protects itself from infections caused by this bacterium. Streptococcus salivarius is a typical inhabitant In the upper respiratory tract and mouth cavity in humans, and it usually does not cause any harm to healthy people. However, it can become an opportunistic pathogen and cause infections in different body parts under certain conditions. Some of the host defenses of Streptococcus salivarius are: 

  • The innate immune system: This is the first line of defense that recognizes and responds to external invaders like fungi, viruses, and bacteria. Physical barriers like the skin & mucous membranes make up the innate immune system. Cellular components include macrophages, neutrophils, natural killer cells, and complement proteins. These cells and molecules can kill or inhibit the growth of Streptococcus salivarius by phagocytosis (engulfing and digesting), oxidative burst (producing reactive oxygen species), antimicrobial peptides (destroying the bacterial cell wall or membrane), or opsonization (coating the bacteria with antibodies or complement proteins to facilitate phagocytosis). 
  • The adaptive immune system: This is the second line of defense that develops a specific and long-lasting response to foreign invaders, such as bacteria, viruses, and fungi. There are two types of lymphocytes in the adaptive immune system: B and T cells. B cells produce antibodies that bind to specific antigens (molecules that trigger an immune response) on Streptococcus salivarius’s surface and neutralize or identify them so that other immune cells can destroy them. a T cell can help B cells produce antibodies or directly kill infected cells by releasing cytotoxic molecules. 
  • The oral microbiota: This is the community of microorganisms that live in the oral cavity and interact with each other and the host. The oral microbiota can prevent or limit the colonization and infection of Streptococcus salivarius by competing for nutrients and space, producing inhibitory substances, such as bacteriocins (proteins that kill or inhibit other bacteria), or modulating the host immune system. 

These are some of the host defenses of Streptococcus salivarius, but there may be more that are not yet known or understood. 

Clinical manifestations 

Streptococcus salivarius is a type of bacteria that usually lives in the oral cavity and upper respiratory tract of humans. It is usually harmless but can sometimes cause infections in certain conditions. Some of the clinical manifestations of Streptococcus salivarius infections are: 

  • Bacteremia is a condition where bacteria enter the bloodstream and cause symptoms such as fever, chills, and low blood pressure. It can happen after dental procedures or tooth brushing that cause trauma to the oral mucosa. 
  • Endocarditis: This is an infection of the interior of the heart chambers or the heart valves. It can cause heart murmurs, chest pain, shortness of breath, and fatigue. It can also lead to complications such as heart failure or stroke. It can occur in people who have pre-existing heart defects or damage. 
  • Meningitis is an inflammation of the membranes that surround the brain and spinal cord. It can cause headaches, stiff neck, fever, confusion, and seizures. It can also result in brain damage or death. It can occur in people with weakened immune systems or head injuries. 
  • Pharyngitis: This is an inflammation of the throat that causes sore throat, difficulty swallowing, and swollen lymph nodes. Additionally, it may result in a skin rash or the soft palate (the area at the back of the roof of the mouth). It can occur in people exposed to someone with strep throat caused by a different species of Streptococcus (Streptococcus pyogenes). 
  • Skin infections: These are infections of the skin that cause red, raised, and painful lesions with distinct margins. They can also cause pus-filled blisters or ulcers. These can occur in people with skin injuries or wounds contaminated by the bacteria. 

These are some possible clinical manifestations of Streptococcus salivarius infections, but they are uncommon. Most people with this bacterium in their mouth or throat do not develop any symptoms or problems. 

Diagnosis 

The diagnosis of Streptococcus salivarius is based on the following steps: 

  • Clinical examination and history: The doctor will ask about the patient’s symptoms, medical history, and risk factors. The symptoms may include fever, swollen/aching limbs, hyperactivity, depression, ataxia, paresis, seizures, paralysis, or signs of endocarditis, meningitis, septic arthritis, osteomyelitis, or abscesses. 
  • Blood culture: The doctor will collect and deliver a lab to analyse a sample of blood. The blood culture will show if there is any bacterial growth in the blood. S. salivarius can be identified by its morphology, biochemical characteristics, and molecular methods. 
  • Other tests: Depending on the site and severity of the infection, the doctor may order other investigations to assess the injury’s severity and 
  • validate the diagnosis. These tests may include urine culture, cerebrospinal fluid (CSF) analysis, echocardiography, magnetic resonance imaging (MRI), computed tomography (CT) scan, or biopsy. 

Control 

Streptococcus salivarius is a typical inhabitant of the oral cavity and upper respiratory tract, and it usually does not cause any harm to healthy people. However, there are some ways to prevent infections caused by this bacterium, especially in people at risk of developing complications. Some of the preventive measures are: 

  • Good oral hygiene: Brush teeth 2x/a day, floss, and use mouthwash to reduce bacteria and prevent dental issues. 
  • Don’t share food/drink: Avoid sharing utensils with people having oral infections to prevent bacterial transmission. 
  • Probiotics: Take Streptococcus salivarius K12 probiotics to prevent or reduce strep throat and respiratory infections potentially. 
  • Seek medical attention: If experiencing strep throat symptoms (sore throat, fever, etc.), see a doctor for diagnosis and antibiotics to avoid complications. 

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