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→Clinical infections
Salmonella spp. are gram-negative straight rods, usually flagellated, facultative anaerobes.
===Overview===
===Overview===
**Stimulate immune response on reaching the lamina propria
**Stimulate immune response on reaching the lamina propria
**Acute inflammation, possibly with ulceration; prostaglandin and cytokine production by epithelial cells; enterotoxin production damaging mucosa
**Acute inflammation, possibly with ulceration; prostaglandin and cytokine production by epithelial cells; enterotoxin production damaging mucosa
**Phagocytosis of bacteria by neutrophils and macrophages
**Phagocytosis of bacteria by [[Neutrophils|neutrophils]] and macrophages
**Bacteria either destroyed by the phagocytic cells or survive and multiply in the cells to cause systemic disease
**Bacteria either destroyed by the phagocytic cells or survive and multiply in the cells to cause systemic disease
**Resistance to phagocytosis and destruction by complement allows spread within the body - bacteraemia and septicaemia
**Resistance to phagocytosis and destruction by complement allows spread within the body - bacteraemia and septicaemia
**LPS O antigens prevent damage to bacterial cell wall by complement
**LPS O antigens prevent damage to bacterial cell wall by complement
**LPS also causes endotoxaemia, and may contribute to local inflammatory response damaging intestinal cells to cause diarrhoea
**LPS also causes endotoxaemia, and may contribute to local inflammatory response damaging intestinal cells to cause diarrhoea
**Endotoxic shock during septicaemic [[Intestines - Fibrinous/ Haemorrhagic Enteritis#Salmonellosis|salmonellosis]] due to LPS
**Endotoxic shock during septicaemic [[Salmonellosis|salmonellosis]] due to LPS
**Septicaemia may cause [[Bacterial skin infections#Systemic bacterial infections|cyanosis of extremities]]
**Septicaemia may cause [[Bacterial skin infections - Pathology#Systemic bacterial infections|cyanosis of extremities]]
**Intracellular carriage if bacteria no completely removed
**Intracellular carriage if bacteria no completely removed
**Invasive potential of certain strains e.g. ''Salmonella'' Dublin associated with carriage of a large plasmid, encoding genes to allow intracellular survival in macrophages and also to allow iron acquisition
**Invasive potential of certain strains e.g. ''Salmonella'' Dublin associated with carriage of a large plasmid, encoding genes to allow intracellular survival in macrophages and also to allow iron acquisition
**Bacteria can survive intracellularly, avoiding the immune system and antimicrobials
**Bacteria can survive intracellularly, avoiding the immune system and antimicrobials
**May have latent carriage and intermittent excretion in faeces
**May have latent carriage and intermittent excretion in faeces
**Stresses e.g. transportaion, illness, parturition, overcrowding promote excretion in carrier animals and may cause clinical signs to be shown
**Stresses e.g. transportation, illness, parturition, overcrowding promote excretion in carrier animals and may cause clinical signs to be shown
**Tortoises, terrapins, snakes and other reptiles ofter carry ''Salmonellae''
**Tortoises, terrapins, snakes and other reptiles ofter carry ''Salmonellae''
**Asymptomatic carriage allows faecal spread of infection
**Asymptomatic carriage allows faecal spread of infection
*Most human infections contracted from animals, especially poulty and cattle
*Most human infections contracted from animals, especially poulty and cattle
*Some serotypes are host-specific, some infect a wide range of species
*Some serotypes are host-specific, some infect a wide range of species
*Healthy adult carnivores are resistant to [[Intestines - Fibrinous/ Haemorrhagic Enteritis#Salmonellosis|salmonellosis]]
*Healthy adult carnivores are resistant to [[Salmonellosis|salmonellosis]]
*Clinical outcome depends on number of bacteria ingested, virulence of serotype, susceptibility of host
*Clinical outcome depends on number of bacteria ingested, virulence of serotype, susceptibility of host
*Young and debilitated animals susceptible
*Young and debilitated animals susceptible
*''Salmonella'' serotypes:
*''Salmonella'' serotypes:
**''S.'' Tymphimurium infects many species; causes severe diarrhoea; non-invasive; causes of food poisoning in humans, e.g. from infected poultry
**''S.'' Typhimurium infects many species; causes severe diarrhoea; non-invasive; causes of food poisoning in humans, e.g. from infected poultry
**''S. enteritidis'': non species-specific; losses in young birds; causes food poisoning in humans
**''S. enteritidis'': non species-specific; losses in young birds; causes food poisoning in humans
**''S.'' Dublin: invasive serovar; infects cattle
**''S.'' Dublin: invasive serovar; infects cattle
**''S.'' Typhi, ''S.'' Paratyphi: infect humans
**''S.'' Typhi, ''S.'' Paratyphi: infect humans
**''S.'' Montevideo produces outbreaks from contaminated imported meat and bone meal
**''S.'' Montevideo produces outbreaks from contaminated imported meat and bone meal
*Enteric [[Intestines - Fibrinous/ Haemorrhagic Enteritis#Salmonellosis|salmonellosis]]:
*Enteric [[Salmonellosis|salmonellosis]]:
**Enterocolitis occurs in most farm animal species affecting all ages
**Enterocolitis occurs in most farm animal species affecting all ages
**[[Intestines - Ulcerative Enteritis|Ulcerative enteritis]]
**[[:Category:Enteritis, Ulcerative|Ulcerative enteritis]]
**Fever, depression, anorexia, foul-smelling diarrhoea containing blood, mucus and epithelial casts
**Fever, depression, anorexia, foul-smelling diarrhoea containing blood, mucus and epithelial casts
**Dehydration and weight loss
**Dehydration and weight loss
**Milder syndrome where endemic on farms, possibly due to acquired immunity
**Milder syndrome where endemic on farms, possibly due to acquired immunity
**Chronic enterocolitis can occur in surviving pigs, cattle, horses, causing intermittent fever, soft faeces and gradual weight loss
**Chronic enterocolitis can occur in surviving pigs, cattle, horses, causing intermittent fever, soft faeces and gradual weight loss
*Septicaemic [[Intestines - Fibrinous/ Haemorrhagic Enteritis#Salmonellosis|salmonellosis]]:
*Septicaemic [[Salmonellosis|salmonellosis]]:
**Most common in calves, neonatal foals, pigs under one month
**Most common in calves, neonatal foals, pigs under one month
**Sudden onset fever, depression, recumbency
**Sudden onset fever, depression, recumbency
**Die within 48 hours if not treated
**Die within 48 hours if not treated
**Persistent diarrhoea, meningitis, arthritis or pneumonia may occur in surviving animals
**Persistent diarrhoea, meningitis, arthritis or pneumonia may occur in surviving animals
**Found in [[Joints - inflammatory#In Horses|arthritis of horses]]
**Found in [[Infectious Arthritis#In Horses|arthritis of horses]]
**Can cause haemorrhagic disease by [[General Pathology - Haemostasis#Secondary Thrombocytopenic Disease|secondary thrombocytopenic disease]]
**Can cause haemorrhagic disease by [[Platelet Abnormalities|secondary thrombocytopenic disease]]
**''S.'' Cholerae-Suis in pigs causes blue discoloration of ears and snout; co-infection with viruses causes severe clinical forms of disease
**''S.'' Cholerae-Suis in pigs causes blue discoloration of ears and snout; co-infection with viruses causes severe clinical forms of disease
*Bovine [[Intestines - Fibrinous/ Haemorrhagic Enteritis#Salmonellosis|salmonellosis]]:
*Bovine [[Salmonellosis|salmonellosis]]:
**Syndrome of fever and diarrhoea (with dysentery), often fatal, in calves and adult cattle
**Syndrome of fever and diarrhoea (with dysentery), often fatal, in calves and adult cattle
**Abdominal pain in adult cattle due to necrotic bowel
**Abdominal pain in adult cattle due to necrotic bowel
***Abortion with no other clinical signs
***Abortion with no other clinical signs
***Chronic infections with ''S.'' Dublin in calves cause dry gangrene of extremities due to disseminated intravascular coagulation; tips of ears, tail and limbs may slough
***Chronic infections with ''S.'' Dublin in calves cause dry gangrene of extremities due to disseminated intravascular coagulation; tips of ears, tail and limbs may slough
***Can cause [[Bones - inflammatory#Osteomyelitis|Osteomyelitis]] in young animals
***Can cause [[Osteomyelitis|Osteomyelitis]] in young animals
***Most survivors become subclinical excretors
***Most survivors become subclinical excretors
***May become latent carriers with no excretion
***May become latent carriers with no excretion
*[[Intestines - Fibrinous/ Haemorrhagic Enteritis#Salmonellosis|Salmonellosis]] in poultry:
*<div id="Spleen">[[Salmonellosis|Salmonellosis]] in poultry:
**''S.'' Pullorum and ''S.'' Gallinarum now rare in UK due to eradication programs including the Pullorum test (whole blood slide agglutination to detect antibody to both ''S.'' Pullorum and ''S'' Gallinarum)
**''S.'' Pullorum and ''S.'' Gallinarum now rare in UK due to eradication programs including the Pullorum test (whole blood slide agglutination to detect antibody to both ''S.'' Pullorum and ''S'' Gallinarum)
**These ''Salmonellae'' can infect the ovaries of hens and be transmitted via eggs
**These ''Salmonellae'' can infect the ovaries of hens and be transmitted via eggs
**Pullorum disease infects young chickens and turkeys (under 3 weeks); high mortality rates; anorexia, depression, white diarrhoea; white nodules throughout lungs; focal necrosis of liver and [[Spleen - Anatomy & Physiology|spleen]]
**Pullorum disease infects young chickens and turkeys (under 3 weeks); high mortality rates; anorexia, depression, white diarrhoea; white nodules throughout lungs; focal necrosis of liver and [[Spleen - Anatomy & Physiology|spleen]]</div>
**Fowl typhoid causes similar lesions to pullorum disease in young birds; septicaemic condition in adult birds with sudden death (enlarged, friable, bole-stained liver and enlarged [[Spleen - Anatomy & Physiology|spleen]])
**Fowl typhoid causes similar lesions to pullorum disease in young birds; septicaemic condition in adult birds with sudden death (enlarged, friable, bole-stained liver and enlarged [[Spleen - Anatomy & Physiology|spleen]]). On post mortem inspection bronzing of the organs is notable.
**Paratyphoid caused by non host-specific ''Salmonella'' serotypes, e.g. ''S.'' Enteritidis and ''S.'' Typhimurium; often subclinical infections
**Paratyphoid caused by non host-specific ''Salmonella'' serotypes, e.g. ''S.'' Enteritidis and ''S.'' Typhimurium; often subclinical infections
===Diagnosis===
===Diagnosis===
==In Reptiles==
It is estimated that between 36 and 77% lizards harbour Salmonella - the most recognized reptilian zoonosis. Owners must be educated regarding the public health hazard (especially for the very young, the old and the immune compromised).
[[Category:Lizard_and_Snake_Glossary]]
[[Category:Enterobacteriaceae]]
[[Category:Zoonoses]]
[[Category:To_Do_-_Bacteria]]