1. Prof. Khalifa Sifaw Ghenghesh
ENTEROBACTERIACEAE
Prof. Khalifa Sifaw Ghenghesh

2. Gram-negative rods
Facultative anaerobes
Oxidase-negative
Most members are motile

3. Gastrointestinal diseases (Diarrhoea and Dysentery)
Escherichia coli (Lac+)
Salmonella (Lac-)
Shigella (Lac-)
Yersinia entercolitica (Lac-)

4. Salmonella E. coli

5. Opportunistic diseases
septicemia,
pneumonia,
meningitis
urinary tract infections
Citrobacter
Enterobacter
Escherichia
Hafnia
Klebsiella
Morganella
Proteus
Providencia
Serratia

7. IDENTIFICATION In Stool: Other sites: E. coli
lactose positive
not usually identified
Common in healthy intestine
Shigella, Salmonella,Yersinia
lactose negative
identified
Other sites:
identified biochemically

8. SEROTYPING Reference laboratory: antigens O (lipopolysaccharide)
H (flagellar)
K (capsular)

9. Escherichia coli

10. Enteropathogenic E. coli (EPEC):
Adhere to surface of mucosal cells inducing dramatic alteration on microvilli and the rearrangement of the host cell actin cytoskeleton.
Adhesion is medicated by two genes:
A Plasmid-encoded gene (bfpA), responsible for the formation of the bundle forming pilus.
A chromosomal-mediated gene (eae) coding for the adhesion intimin.
fever
diarrhea
vomiting
nausea
non-bloody stools

11. Enterotoxigenic E. coli (ETEC):
Cholera-like diarrhoea
milder
Travellers diarrhoea
Heat labile toxin (LT)
like choleragen (Cholera toxin)
activate enterocyte adenyl cyclase
cyclic AMP
chloride and water secretion >>Diarrhea
Heat stable toxin (ST)
activate enterocyte guanylate cyclase
cyclic GMP
Chloride and water secretion >> Diarrhea

12. Enteroinvasive E. coli (EIEC):
Dysentery
resembles shigellosis

13. Enterohemorrhagic E. coli (EHEC):
Usually O157:H7
Meat
Hemorrhagic
bloody, copious diarrhea
few leukocytes
afebrile
Hemolytic-uremic syndrome
hemolytic anemia
thrombocytopenia (low platelets)
kidney failure
Vero toxin (Shiga-like):
2 toxins: SLTI and SLTII (coded by sxt1 and sxt2)

14. TREATMENT Gastrointestinal disease: e.g. hemolytic-uremia syndrome
Fluid replacement
Antibiotics
not used usually unless systemic
e.g. hemolytic-uremia syndrome
UTIs:
Antibiotic Sensitivity Is Necessary.

15. Resistance of Escherichia coli isolated from
urinary tract infections in Benghazi to antibiotics.
Hospital Community
Antibiotic acquired acquired
(n=62) (n=148)
Ampicillin 52(84)* 111(75)
Carbenicillin 53(85) 117(79)
Cephaloridine 22(35) (36)
Chloramphenicol 37(60) (45)
Gentamicin 19(31) (18)
Nalidixic acid (5) (10)
Nitrofurantoin 4(6) (7)
Tetracycline 45(73) 121(82)
Trimethoprim 52(84) 120(81)
sulphamethoxazole *(%)

16. Shigella

17. Bacillary Dysentery Shigellosis bloody faeces intestinal pain pus
4 Major O Antigenic Groups:
Serogroup A = Sh. dysenteriae
Serogroup B = Sh. flexneri
Serogroup C = Sh. boydii
Serogroup D = Sh. sonnei
No H-Antigens.

18. Shiga Toxin enterotoxic cytotoxic inhibits protein synthesis
lysing 28S rRNA

19. The Organism Survive
the Passage Through the GIT >> Due to O Antigen
Attach to Colonic Cells.
Penetrate the Epithelial
Cells. >> "Invasiveness"
"Inflamation, Cell Death, Ulceration, Impaired
Multiply Inside >> Colonic Fluid Absorbtion and a Discharge of Blood, Mucus and Pus"
Pass to Another Cell.

20. Man only "reservoir"
Mostly young children
fecal to oral contact
children to adults
Transmitted by adult food handlers
unwashed hands

21. Patients respond to antibiotics
Treating Shigellosis
Manage dehydration
Patients respond to antibiotics
disease duration diminished

22. CONTROL Adequate Sanitization. Detection and Treatment of Carriers.
Carriers Should Not Be Allowed to Handle Food.
Proper Sewage Disposal and Chlorination of Water.
FLIES >>>>>>>>>>>>>>>>

23. Information about Libyan children with diarrhea and their Shigella isolates
Patient Sex Age Month of Length of Episode Species and
(Mo) occurrence diarrhea per day serotype of
(days) Shigella
F Sep S. sonnei
F Sep S. flexneri type2
M Oct S. sonnei
F Oct S. flexneri type2
F Oct S. flexneri type2
M Dec S. flexneri type1
M Apr S. flexneri type2
M Jun S. flexneri type3
M Jul S. sonnei

24. Information about Libyan children with diarrhea and their Shigella isolates
Faeces with Presence of
Patient Mucus Blood Fever Vomiting Species and
serotype of
Shigella
S. sonnei
S. flexneri type2
S. sonnei
S. flexneri type2
S. flexneri type2
S. flexneri type1
S. flexneri type2
S. flexneri type3
S. sonnei

25. Salmonella

26. More than 2000 antigenic types (Serotypes).
Salmonella Typhi
Salm. Enteritidis
Salm. Cholera-suis
Salm. Typhimurium
Genetically single species
Salmonella enterica
Salm. enterica serotype Typhi
ANTIGENIC STRUCTURE:
O & H Antigens >>> Serotyping.
Vi-Antigen (protective) >>> Salm. Typhi.

27. CLINICAL INFECTION AND PATHOGENSIS
1. S. Typhi, S. Paratyphi A and B:
Gastroenteritis, bacteremia and typhoid fever.
Typhoid Fever (Enteric fever):
Fever, headache, diarrhoea, and abdominal pain.
Human Carriers Are the Only Source of Infection.
Transmission:
contaminated food
water supply
poor sanitary conditions
Mortality Rate:
Relapse:

28. 2. S. Enteritidis, S. Typhimurium, etc..
Salmonellosis:
Self-limiting gastroenteritis with fever for <2 days and diarrhoea < 7 days.
Source:
poultry, eggs
no human reservoir
Transmission:
Pets:

29. TREARMENT:
Supportive Therapy and Maintaining Fluid and Electrolyte Balance.
Enteric Fever or Septicaemia:
Antibiotics
essential
Carriers of Salm. typhi:
CONTROL:
Carriers:
Food Cooked Properly
Water Standards Be Observed.

30. Salmonella Serotypes Isolated from Diarrhoeic Faeces in Tripoli (1975-1980)
S. Wien
S. Muenchen
S. Typhimurium
Salmonella Serotypes Isolated from Children with Diarrhoea in Tripoli ( )
S. Saintpaul
Salmonella Serotypes Isolated from Children with Diarrhoea in Zliten ( )
S. Heidelberg
S. Enteritidis

31. Reistance of Salmonella species isolated from children with diarrhoea in Zliten ( ) to antibiotics
________________________________________________
Antibiotic No. (%) resistant:
(n=23)
Ampicillin (100)
Amoxicillin+calvulanic acid 22 (95.7)
Cefoxitin (87)
Gentamicin (78.3)
Doxycycline (91.3)
Chloramphenicol (95.7)
Nalidixic acid (4.3)
Norfloxacin (0.0)
Trimethoprim-sulphamehtoxazole 1 (4.3)

32. Department e-mail = dmi.ly Khalifa Sifaw Ghenghesh e-mail =