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Prof. Khalifa Sifaw Ghenghesh

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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

6

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 =


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