Yersinia

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Yersinia

• Prepared by-Prof.Dr.Sundus.S.Bakr

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Yersinia

• Member of Enterobacteriaceae
• Gram negative, small rod shape
• Y. enterocolitica,
• Y. pseudotuberculosis,
• Y. pestis

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• Cells of Yersinia are small 1mm or less on
  nutrient agar
• Y. enterocolitica, Y. pseudotuberculosis, Y.
  pestis are the three pathogenic species
• Y. enterocolitica and Y. pseudotuberculosis cause
  the food borne disease.
• Y. Pestis causes the bubonic plague or black
  death in Europe

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Yersinia
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Yersinia
Gram-negative rods.
Small rods
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Yersinia
Yersinia
Enterobacteriaceae
Growth of Y. enterocolitica on blood agar medium
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Yersinia
18 hours incubation on MacConkey Agar at 37C
18 hours incubation on Yersinia entreo Selective
Agar at 37C
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Yersinia

• Low temperature pathogen
• Able to grow at 4C
• Some biochemical characteristics are temperature
  dependent
• expose at 28-30C but not at 37C
• Mobile below 30C but not at 37C
• Incubation at 37C ?loss of the virulence plasmid
  plasmid mediated properties
• Yersinia is psychrotroph.
• So, may continue to grow under refrigeration

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Yersinia
Influence of incubation temperature in the
motility of Y. enterocolitica
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• At 28C Y. enterocolitica is motile and is seen
  (arrowed) spreading away from the stab inoculums
  during growth in semi-solid medium.
• At 37C, the org. is non-motile

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Yersiniosis

• Infectious disease caused by Yersinia
• Only Y. enterocolitica and Y. pseudotuberculosis
  cause gastroenteritis
• Symptoms
• Gastroenteritis
• Abdominal pain, diarrhea (often bloody) ,
  vomiting, fever
• In older children and adults, right-sided
  abdominal pain (pseudo-appendicitis)
• Right sided abdominal pain may be confused with
  appendicitis.
• In a small proportion of cases, complications
  such as skin rash, joint pains, or spread of
  bacteria to the bloodstream can occur.

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Yersiniosis

• Onset illness, between 24 to 48 hours after
  ingestion
• Occasional Y. enterocolitica GI infection
  followed by arthritis of peripheral joints
• 2 - 6 weeks after intestinal infection clears
• Called reactive arthritis (Reithers syndrome)
• may occur even in the absence of obvious
  symptoms.

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Yersiniosis
VS
Bacterial antigen
Arthritis of peripheral joint (post food
poisoning consequences)

• The frequency of postenteritis arthritic
  conditions is about 2-3

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• Can occur with people who has human lymphocyte
  antigen B27 (HLA-B27) the antigen exposed on the
  host cell
• Thought to be caused by T-cells and/or antibodies
• elicited by antigens that cross-react with host
  antigens, not by infection of the joints
• common in people with histocompatibility antigen
  HLA-B27 (exposed on surface of host cells)
• antibodies vs. bacterial surface antigens
  cross-react with human B27, activate C'
• T-cells recognizing B27 may attack host cells

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Yersinia enterocolitica

• Optimum temperature 22-29C (range of -2 to 45C)
• Foods involved in transmission
• Meats (pork, beef, lamb, etc.)
• Oysters, fish
• Raw milk
• Prevalent in the soil and water and in animals
  such as pigs

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Yersinia enterocolitica

• Infected by
• Eating contaminated food ? raw or undercooked
  pork products
• Drinking contaminated unpasteurized milk or
  untreated water
• Susceptibility
• Infants, children
• Compromised adults
• individuals with the antigen HLA-B27
  (postenteritis arthritis)

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Yersinia pestis
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Hosts of Yersinia pestis

• Mammalian
• Human
• Rodent
• Insect
• Xenopsylla cheopis

http//www.channel4.com/history/ microsites/H/hist
ory/plaegu/plague.html Science Picture Library
www.exn.ca/Stories/ 2000/09/12/52.asp
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Symptoms
idcs0100.lib.iup.edu/ WestCivI/the8.htm
www.imcworldwide.org/ cbr/L1C-m2.html
http//aci.mta.ca/Courses/Biology/Images/bacterial
20folder/Plague.html

• Bubonic
• Pneumonic
• Septicemic

www.niaid.nih.gov/dir/ labs/lhbp/hinnebusch.htm
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Transmission Cycles The transmission cycle of Y.
pestis is vector-dependent, and is usually
dependent on X. cheopis, the rat flea
www.pon.nic.in/fil-free/ vcrc/plague.html
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Diagnosis

• Diagnosis is based primarily on clinical
  suspicion - USAMRIID
• Staining
• Culture

http//www.cdc.gov/ncidod/dvbid/plague/p4.htm
www.einsamer-schuetze.com/natur/krankheit/pest/bed
rohung.html
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• Diagnosis for Y. pestis is based on staining
  blood, sputum, CSF or lymph node aspirates with
  Gram, Wayson or Giemsa staining, but a definitive
  diagnosis requires a culture.
• The green picture at the top of the slide is a
  presumptive positive confirmation via
  immunofluoresence for the presence of F1
  antigen, which is specific to the Y. pestis .The
  tan picture Is an SEM image of Y. pestis from
  culture.
• Currently, only culturing is the definitive
  method of confirming a diagnosis of bubonic
  plague,
• The Rapid Detection Test is being
  collaboratively developed by the WHO Coll.
  Center for Plague in Madagascar and France, as
  well as the Ministry of Health in Madagascar

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Treatment

• ANTIBIOTICS- streptomycin ,ciprofloxacin or
  doxycycline
• Development of resistant strains

http//content.nejm.org/cgi/content/full/337/10/67
7
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Pathogenesis

• Evolution
• Plasmids
• Type III Secretion
• Virulence Factors

dr-gng.dp.ua/death/ black/death_0.htm
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Plasmids

• pPCP1 interferes with blood coagulation.
• pPMT1 have a role in resisting monocytic
  phagocytosis.
• pCD1 the most important plasmid necessary for
  virulence in Y. pestis.

http//tecfaetu.unige.ch/wiki/index.php/PrincipeTr
ansgenese
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Type III Secretion

• Yersinia pestis relies on Type III secretion for
  many of its anti-immune system properties
• A major component of Type III secretion is the
  Injectisome
• Yops inhibit phagocytosis

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Virulence Factors

• Invasins
• Tyrosine Phosphatase
• , Y. pestis is well equipped to both avoid
  phagocytosis and to deal with engulfment

http//www.jbc.org/cgi/content/full/280/11/10388
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Detection

• Rapid Detection Test
• The RDT is a test sensitive to the presence of
  the plague-specific F1 antigen using monoclonal
  antibodies.

www.allwestselectsires.com/ ecf.asp
www.testsymptomsathome.com/ TEC01.asp
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Thank you