what can some species of salmonella cause
some can cause Typhi and enteric fever and some cause Entrocolitis
what are some characteristics of Salmonella
- Production of H2S ( S.typhi Less amount)
- Bile resistant
- non lactose fermenter
- surgace antigen ( o,Vi)
what are some routes of transmission?
- it is strict human pathogen ( typhi, paratyphi)
- high infectious dose
- spread person to person
- mostly contaminated food
- can cause septicemia
- some are zoonotic but can cause disease in human ( s.Entriditis >eggs)
- can cause gasteroentritis, entrocolitis and septecimia
- mostly in hot seasons in outdoor events
- associated with poultry, eggs, diary product, food made on contaminated surface
- childeren <5, Elder >60
which salmonella infection is carried by asymptomatic carrier?
what are most salmonelisis caused by?
S.enteritidis and S.typhimerium
where are most salmonella spp found?
they are mostly in animal feces
who is at great risk of typhoid fever
who was the asymptomatic carrier of typhoid fever
what are some clinical manifestation associated with gasteroentritis and entrocolitis
- symptoms are 6 to 8 hrs
- nausea and vomiting
- abdominal pain and non bloody diarrhea
- self limiting
what are some signs of enteric fever?
- 10 to 14 days incubation period
- weakness and stomach pain, headache and rash
- no diarrhea
- high fever
- can be fatal
- survivors can be asymptomatic
what are some factors associated with septecimia?
- most common in S.typhi and paratyphi
- people vary in susceptibility
what are cells in intestinal epithelium?
- M cells antigen sampling
- goblet cell mucin secretion
- paneth cell antibacteria protein secretion
- entrocyte nutrition absorption
- IEL epithelial leucocyte
- DC denderic cell
what is invasome
specific surface appendage of salmonella, shorter and thicker than pili and only expressed during attachments.
what mechanism does salmonella use for invasion?
what is the difference between zipper and trigger mechanism?
zipper induces local changes whereas trigger induce a large scale response.
what is a TTSS?
it is a multiprotein complex that all entrobacteriea will rely on for virulence. structure resembles syring and it is used to inject virulance factor into host cell.
what factors contribute to pathogenesis of salmonella?
- endotoxin and LPS
- Invasome and fimbrease
- Multitude of specific virulance factor
what does SPI 1 do in salmonella?
Important for invasion of entrocytes and encodes for TTSS and protein
what are some diognostic tools for salmonella?
- Isolation from stool or blood
- Hekton and XLD media > allows growth of salmonella and shigella
- Stereotype > trace origin of outbreak ( O, H, Vi)
what are some ways to treat gastroentritis ?
- dehydration prevention
- balance electrolyte
- avoid antibiotic to prevent prolonged carrier state
what are some ways to treat enteric fever and septecemia?
Ampicilin / trimethroprim / sulfamethoxazole/ ciprofloxin ( antibiotic resistance in vitro testing)
what are some ways to treat typhoid fever?
live attenuated vaccine and polysaccharides vaccine