L5: Enterobacter II Flashcards
- What tribe is Shigella a part of?
- Lactose + or -?
- Indole + or -?
- Motile?
- Co2 + or -
- What is its habitat?
- Tribe I - Escherichieae
- Lactose NEGATIVE
(E.Coli is positive) - Indole negative
- NOT MOTILE
- CO2 negative
- Habitat = intestines of humans
How does Shigellavary from E.COli in terms of:
- Lactose fermentation
- Gas production
- Motility
- NON LACTOSE FERMENTER
- Non gas producer
- Non - motile
SHigella:
- Transmission via _____
- 5f’s
- Highest risk individuals?
- Person to person via fecal oral route
- Contaminated WATER, food, flies, fingers, fomites, feces (5f’s)
- Young children in day care center/nurseries
- siblings/parents of these children
- MALE HOMOSEXUALS
PATHOGENESIS of Shigella:
- Virulent strains carry ____ for attachment and entry
- Enters cells by _____
- Organism escapes in _____
- Intracellular _____ (in cytoplasm)
- _____ drives organism in cytoplasm
- Organisms enter adjacent cells - Shigella phagocytosed into new cell and released into ____
- Shigella can KILL _____
- plasmid
- phagocytic vacuole
- cytoplasm
- replication
- Actin “tail”
- cytoplasm
- PHAGOCYTIC MACROPHAGES
Shigella infection does not extend where?
Unlike Salmonella, does it require a low or high inocolum?
Lamina propria!
LOW inoculum to cause disease for shigella!
What is the major clinical syndrome of shigella?
What are symptoms of this syndrome?
What is tissue invasion limited to?
How long is the incubation period? How long does it last?
- Bacillary Dysentry
- Abdominal cramps, tenesmus, pus and BLOOD in stool
- Tissue invasion limited to EPITHELIAL. cells and SUBMUCOSA
Fecal leukocytes present
- Incubation 1-3 days lasting 48 hrs.
HUMAN SERVES AS NATURAL HOST
Edwardseilla tarda is found in what habitat?
What tribe is this?
- Cold blooded vertebrates, fresh water, catfish
Tribe II - Edwardsielleae
Genus Edwardsiella
What are the clinical symptoms of E. Tarda?
(2)
Is the diarrhea bloody?
What is it often mistaken for? (2)
- Gastroenteritis
- Septicemia (rare)
- acute, self-limiting w/ watery diarrhea
Typhoid like illness with BLOODY diarrhea & possible fever, nausea, vomiting, colonic ulcerations & terminal ileum modularity
- Mistaken for:
- Salmonellosis
- IBD (Crohn’s)
What is the habitat for Salmonella (Tribe III)?
a) non-typhoid
b) S.typhi
- INTESTINEs of Lower animals (poultry, cows, pigs, pets) for non-typhoid strains
- Humans for S. typhi
Salmonella:
- Lactose fermenter?
- Produces ____ (black)
- Trasmission via____
- Found where? (2)
- Secondary transmission ____
- NON - LACTOSE fermenter
- H2S positive
(grows black colonies on Nekton Agar plates) - transmission via Improper food handling
- Found in humans and livestock
- Secondary transmission person-to-person***
Salmonella is Encapsulated. T/F
Samonella is acid STABILE T/F
- TRUE
- FALSE - Salmonella is acid LABILE (think of lemon on salmon = acidic)
- Need HIGH DOSE to cause infection
Almost half of salmonella epidemics are a result of contaminated_____
contaminated poultry and poultry products
- Also associated with reptiles (lizards, snakes, turtles)
What are the 5 clinical syndromes of Salmonella?
- Asymptomatic (carrier state)
- Febrile Gastroenteritis
- Enteric fever
- Septicemia
- Focal Infections
- The asymptomatic (carrier) state is mostly seen with S. Typhi (T/F)
- TRUE
- limited with non-S.Typhi
What clinical syndrome of salmonella does the following describe:
- Most common
- Incubation of 12-48 hours
- Symptoms: malaise, nausea, sometimes with vomiting, followed by abdominal pain and diarrhea.
- Self-limited.
- Duration 3-5 days.
T/F: Not treated with antibiotics
FEBRILE GASTROENTERITIS
TRUE: Do NOT treat with antibiotics.
WHY???
Can destroy normal flora
Create antibiotic resistant Salmonella strain
Enteric Fever:
- ____ is best example
- Caused by ___ and ____
- Incubation period?
- Length of illness?
- What are the 2 stages of Enteric Fever?
- What is the only known reservoir of S. Typhi?
BIMODAL DISEASE
- Typhoid fever
- S. Tyhphi & S. Paratyphi A & B
- Incubation 1-2 weeks
- Length is 4 weeks
a) fever for 2 weeks (bacteremic stage)
b) GI symptoms for 2 weeks
6. Only known reservoir of S. typhi is man
The following describes what syndromes of Salmonela?
1.Osteomyelitis, meningitis, brain abscess, endocarditis *
- -found in patients with
underlying leukemia, lymphoma, AIDS, SLE, sickle cell crisis, and alcoholic hepatitis.
- Found frequently in infections due to S. choleraesuis, S. dublin, and S. oranienburg.
Relapses are common
- Focal Infections
2. Septicemia (w.o major GI involvement)
Pathogenesis of Gastroenteritis:
- Salmonella produces
produces an _____»_space; stimulates rearrangement of plasma cell membrane to form ruffles. - Bacteria enter cell by ______
- Organisms invade what 3 areas?
- What is the result?
- adhesin
- by pinocytosis associated with ruffles
- Organisms invade large and small bowel and lamina propria
- Large inflammatory response induced
Pathogenesis of Enteric Fever:
- Bacteria bind to ___ cells
- Infection KILLS cell, bacteria go to what area of intestine?
- Organisms invade ____ where they multiply
- Inhibition of ____ allows organisms to survive intra-cellularly.
- Bacteria spread from ____ to ___. (bloodstream)
- What is a major virulence factor causing SEPTIC shock?
- Immunity is mediated by what?(2)
- M cells
- Peyer’s patches
- macrophages
- oxidative metabolic burst
- Peyer’s patches to Blood stream
- LPS
- Humoral & Cell mediated
(T & B cell)
- S. typhi occurs only in humans
Transmission person-to-person
The following are clinical presentations of what?
- Presents with fever, headache, rose spots, constipation
- Rose spots; pink macules or prupuric lesions
- Fever; temperature-pulse dissociation
(Refers to relative bradycardia with a pulse rate less than expected at a given body temperature. Associated with specific infections, including intracellular organisms such as salmonella, legionella, and chlamydia)
- Neuropsychiatric manifestions
Salmonella ENTERIC FEVER
What are some complications of Salmonella Enteric Fever?
- GI bleeding
- Perforation of ileal ulcers
- Circulatory collapse
- Relapse following treatment
- Long term carriage
Salmonella BACTEREMIA
(bimodal disease)
- Increased risk in what 3 patient groups?
- Similar clinically to other ___ bacteremia
- 10% localized ____ infections (examples)
- HOW IS IT DIAGNOSED?
- WHAT IS THE TREATMENT???
1.
a) pediatric
b) geriatric
c) AIDS patients
- gram (-)
- SUPPURATIVE
- Positive blood cultures
- THIRD GENERATION CEPHALOSPORIN
What is the treatment for Salmonella BACTEREMIA?
How is it diagnosed?
- 3rd generation CEPHALOSPORIN
2. Positive blood culture
A 50 year old female returned to Chicago from a 3 week trip to Jakarta (Indonesia) and about 5 days later started having flu like symptoms and a low grade fever. On the day prior to admission she had spiking fevers followed by profuse sweating. Stool cultures, ova and parasite exams and urine cultures were all negative. The blood culture collected after a spiking fever episode grew a glucose-fermenting, gram-negative rod that was oxidase negative. Additional testing showed the organism was lactose-negative and H2S positive. What is the likely etiologic agent of this patient’s symptoms?
Shigella E. coli O157 Malaria (Plasmodium falciparum) Salmonella typhi Vibrio cholera
Salmonella typhi
STOOL CULTURE NEGATIVE –> first 2 weeks septic (bactermia)
next 2 weeks = diarrhea
always get BLOOD AND STOOL if not sure in which stage!!!!
TEST QUESTION:
what sample should be sent to lab if typhoid fever?
BLOOD & STOOL
What tribe do the following fall under?
- C. freundii, C. koseri
What habitat are they found in?
TRIBE IV: Citrobactereae
Habitat: intestinal tract humans/animals
What are the clinical syndromes of Citrobacter infections? (general) -3
- Specifically of C. Freundii
- Specifically for C. Koseri
- a) Nosocomial infections of urinary and respiratory tracts of debilitated, hospitalized patients
b) endocarditis and
c) hospital acquired bacteremias - C. freundii - rare cause of diarrhea
- C. koseri - rare cause of meningitis and brain abscess in neonates
neonatal menigitis:
- E.Coli
- Citrobacter KOSERI
The following species are under which tribe & Genus?
K. pneumoniae,
K. oxytoca, K. ozaenae,
K. rhinoscleromatis
What habitat are they found in? (2)
- Tribe V: Klebsielleae
2. Intestines & UPPER RESPIRATORY TRACT of humans & animals
What is the Klebsiella species responsible for the following clinical syndrome: (2)
Primary lobar pneumonia characterized by destructive changes
necrosis
hemorrhage
(“currant jelly” sputum)**
bronchopneumonia
bronchitis,
accounts for 9% of UTI’s
and 14% of bacteremias in hospitalized patients
1) K.pneumoniae
2) K. oxytoca
What is the Klebsiella species responsible for the following clinical syndrome:
rhinoscleroma
chronic granulomatous disease involving mucosa of upper respiratory tract ***
K. rhinoscleromatis
What is the Klebsiella species responsible for the following clinical syndrome:
atrophic rhinitis (ozena)
destruction of mucosa
and fetid mucopurulent discharge (nose)
K. Ozaenae
What genus of Tribe V Klebsiella do E. aerogenes & E. cloacae fall under?
Genus: ENTEROBACTER
Widely distributed in environment & GI tract of humans
What are the clinical symptoms of Enterobacter?
- frequent colonizers of ____
- cause ______ involving urinary tract, respiratory tract, cutaneous wounds
- occasional cause of _____ and _____
- Antibiotic treatment can be ineffective T/F
- HOSPITAL patients
- opportunistic infections
- septicemia
meningitis - TRUE
- because the organisms are frequently resistant to multiple antibiotics (resistance genes)
What important SPECIES is part of the genus Serratia under Tribe V Klebsielleae?
Habitat?
How do Serratia appear on MacConkey?
S. Marcescens
Widely distributed in the environment
Appear RED
- not because fermenting lactose but because the colonies are RED
Name some clinical syndromes of Serratia.(5)
What syndromes relate to IV drug addicts? (2 new ones)
- Nosocomial infections
- pneumoniae,
- septicemia,
- UTI
- surgical wound and
cutaneous infections.
IV DRUG USERS:
- Endocarditis
- Osteomyelitis
- What are the species in TRIBE VI Proteae? (2)
- a) What are the KEY ID FEATURES ? (TEST question)
b) Lactose neg or pos?
c) Urease neg or pos?
- Habitat?
- P. mirabilis
P. Vulgaris - SWARMING observed on blood agar
b) Lactose NEGATIVE
c) Strongly UREASE POSITIVE - Soil, water and intestinal tract of humans and animals.
What is the only organism that SWARMS and grows in spurts?
PROTEAE!!! (mirabilis & Vulgaris)
- indol test to separate the two
Which of the Proteus species is described by the following:
- most commonly recovered from infected sites in IC patients (immunocompromised)
- is most frequently isolated species, cause of UTI and wound infections.
- Strongly urease positive produces highly alkaline urea which can lead to renal CALCULI composed of struvite (magnesium ammonium phosphate) –test question
- P. Vulgaris
- P. Mirabilis
(think of balls–> urease positive (a lot of ammonia and Co2) –> HIGH ALKALINE UREA –> renal calculi–> make struvite)
Proteas Mirabilis causes ___ and has a ____ odor.
Tx?
What type of motility does it exhibit when plated? (only one that does this)
- UTI
- Fishy odor
- SULFONAMIDES (also treat nocardia with sulfonamides)
- SWARMING MOTILITY
- because it is urease positive it produces a lot of ammonia and CO2 which leads to a very alkaline environment creating STRUVITE stone precipitates in the renal pelvis –> CALCULI form
Yersinia Enterolitica:
- Pinpoint colonies on
MacConkey at ____ - Biochemical tests should be incubated at ___ Celcius
- Usually transmitted from what 3 things.
- Causes acute ___ or pseudo ____
- 24 h
- 25C
- a) puppy feces (kids)
b) contaminated milk
c) pork - Acute diarrhea
or
Pseudoappendicitis
(RLQ pain)
Y. Enterolitica:
- Most common spp in ______
- Widely distributed in _____
- Epizootic outbreaks of ___ (4)
- Predominant subgroup?
- clinical specimens
- lakes and reservoirs
3.
- diarrhea
- lymph-adenopathy, - pneumonia, and
- spontaneous abortions
- O:3
- What is the major reservoir for infection of Y. Enterocolitica?
- Associated with?
- Portal of entry?
- PIGS for infection in humans
- Associated with household preparation of chitterlings
- ORAL DIGESTIVE ROUTE
Y. Enterocolitica:
Organism adheres to and penetrates the ileum causing what (3)
What does it mimic?
Most common in ____.
- terminal ileitis
- lymphadenitis
- and acute enterocolitis.
- Mimics APPENDICITIS (also in first aid)
- CHILDREN
Enterocolitis accounts for 2/3 of infection. Diarrhea, fever, abdominal pain lasting as long a 1-2 weeks.
- Chronic form can persist mos to > yr
Y. Enterocolitica
- Also associated w/transfusion related sepsis, arthritis, intraabdominal abscess, hepatitis, osteomyelitis
- Blood contamination occurs due to asymptomatic Y. enterocolitica bacteremia at time of blood donation
- Y. enterocolitica can proliferate in blood stored at 4o C after 2-3 weeks
A 1-year-old African-American patient was brought into the emergency room of an intercity hospital suffering from diarrhea and subsequent dehydration. The family reports that the illness began a couple of days after Christmas. In questioning the parents about food-born source of the infection the parents reported serving chitterlings to the adults but not the children. A stool specimen sent to the laboratory grew a lactose-negative gram-negative bacillus that gave biochemical reactions typical of E. coli except that the organism was urease positive. What is the most likely identity of the bacterium?
E. coli 0157:H7 Salmonella serotype arizonae Yersinia enterocolitica Vibrio cholerae Edwardsiella tarda
Y. Enterocolitica
