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Labdx g iinfection_print

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  1. 1. Laboratory Diagnosis for Common Gastro-intestinal Infections Dr Vincent CC Cheng Department of Microbiology Queen Mary Hospital
  2. 2. Diagnostic Clinical Microbiology
  3. 3. 其 中 11 名 男 子, 進 食 過 燒 味 、 海 鮮 卷 、 石 斑 、 貴 妃 雞 及 鮮 鮑 蚌 等 食 品 St l lt S l ll t itidi (2008-06-17 HKT 00:27) Stool culture: Salmonella enteritidis MacConkey XLD agar
  4. 4. Food borne infectious diseases Water (untreated) Salmonella, shigella, cholera H titi A/E C li i i /N lk i il litiHepatitis A/E. Caliciviruses/Norwalk virus, poilomyelitis Giardia, cryptosporidium, cyclospora Dairy (unpasteurised) Brucella, listeria, salmonella, shigella (unpasteurised) Raw or Enteric bacteria (salmonella, shigella, C. jejuni, etc) undercooked food ( g j j ) Helminths (ascaris, trichinella, taenia, etc) Protozoa (amoebiasis, toxoplasma)
  5. 5. E t i fEnteric fever Salmonella typhi & S. paratyphiyp p yp Increasing fever over 1–2 weeks Headache, abdominal pain & cough Rose spots Fleeting lesions 2 - 3 mm pink-red macules Rose spots p blanch with pressure
  6. 6. Blood culture
  7. 7. Antigenic formulae of some representative serotypes of Salmonella (Kaulffman-White classification) O-antigen group A Serotype name Paratyphi A O antigens and Vi 1,2,12 H antigens (I) a H antigens (II) 1,2 B Paratyphi B Typhimurium Agona 1,4,5,12 1,4,5,12 1,4,12 b i f,g,s 1,2 1,2 - C1 Heidelberg Choleraesuis Paratyphi C 1,4,5,12 6,7 6 7 Vi r c c 1,2 1,5 1 5Paratyphi C Virchow Infantis 6,7, Vi 6,7 6,7 c r r 1,5 1,2 1,5 C2-C3 D1 Newport Hadar Typhi 6,8 6,8 9,12, Vi e,h z10 d 1,2 e,n,x - Enteriditis Dublin 1,9,12 1,9,12, Vi g,m g,p - -
  8. 8. Dysentery Low infectious doseDysentery Intracellular multiplication EHEC, Shigella EIEC, Campylobacter Clin Microbiol Rev. 1998 Jan;11(1):142-201
  9. 9. Shigella species Dept. of Microbiology, QMH
  10. 10. Campylobacter jejuni CCDA (charcoal-cefoperazon-deoxycholate agar) Microaerophilic atmosphere: 5% O2, 10% CO2, 85% N2 42oC, 3 days
  11. 11. Dept. of Microbiology, QMH
  12. 12. Serotype of E. coli isolated from human diarrheal illness O6:NM O6:H16 O114:H21 O115:H21 O26:NM O26:H11 O28ac:NM O29:NM O1:NM O1:H1 O23:H7 O23:H16 O55:H10 O73:H34 O111:NM O111:H2 O119:H5 O119:H6 O141:NM O145:NM ETEC EPEC EIEC EHEC O6:H16 O8:H9 O11:H27 O15:H11 O115:H21 O126:H9 O128ac:H12 O128ac:H21 O26:H11 O55:NM O55:H6 O55:H7 O29:NM O112ac:NM O115:NM O124:NM O1:H1 O1:H7 O2:H1 O2:H5 O23:H16 O25:NM O26:NM O26:H2 O73:H34 O75:H5 O82:H8 O84:H2 O111:H2 O111:H7 O111:H8 O111:H30 O119:H6 O120:H19 O121:NM O121:H8 O145:NM O145:H25 O146:NM O146:H21 O29:NM O25:NM 025:H42 O27:NM O128ac:H27 O148:H28 O149:H4 O153:H45 O86:NM O86:H2 O86:H34 O111ab:NM O124:H7 O124:H30 O135:NM O136:NM O2:H6 O2:H7 O4:NM O4:H10 O26:H8 O26:H11 O26:H32 O38:H21 O85:NM O86:H110 O88:NM O91:NM O111:H34 O111:HNT O112:H21 O113:H2 O121:H19 O125:NM O125:H8 O126:NM O153:H25 O157:NM O157:H7 O163:H19O27:NM O27:H7 O27:H20 O49:NM O159:HNM O159:H4 O159:H20 O111ab:H2 O111ab:H12 O111ab:H21 O143:NM O144:NM O152:NM O4:H10 O5:NM O5:H16 O6:NM O39:H4 O45:NM O45:H2 O91:NM O91:H14 O100:H32 O101:H19 O113:H2 O113:H7 O113:H21 O113:H53 O126:H8 O126:H21 O128:NM O163:H19 O165:NM O165:H10 O165:H19 O63:H12 O78:H11 O78:H12 O85:H7 O166:H27 O167:H5 O169:H41 O114:NM O114:H2 O119:H6 O128ab:H2 O164:NM O167:NM O6:H1 O6:H28 O18:NM O18:H7 O48:H21 O50:NM O50:H7 O52:H25 O103:H2 O103:H6 O104:NM O104:H21 O114:H4 O114:H48 O115:H10 O115:H18 O128:H2 O128:H8 O128:H12 O128:H25 O165:H25 O166:H12 O166:H15 O142:H6 O158:H23 O22:H8 O22:H16 O55:NM O55:H7 O105:H18 O110:H19 O117:H4 O118:H30 O132:NM O133:H53
  13. 13. Serotype of E. coli O157:H7 Dept. of Microbiology, QMH
  14. 14. Treatment of bacterial dysentery Ciprofloxacin Dose (mg) po Levofloxacin Norfloxacin 500 500 400Dose (mg) po Cmax (µg/ml) T1/2 (hr) 500 2.4 3 - 5 500 5.7 6 - 8 400 1.5 2 - 4 Cost (HK$) (3-d) 51.6 51.6 40.1 MIC90 (µg/ml) E. Coli Shigella spp 0.25 0.06 0.5 0.03 0.12 0.12Shigella spp Campylobacter 0.06 64 0.03 32 0.12 NA Fecal concentration: 100 1000 x serum concentrationFecal concentration: 100 - 1000 x serum concentration
  15. 15. Treatment of bacterial dysentery Ciprofloxacin Dose (mg) po Azithromycin 500 500 10 mg/kgDose (mg) po Cmax (µg/ml) T1/2 (hr) 500 2.4 3 - 5 500 0.41 68 10 mg/kg (Children) Cost (HK$) (3-d) 51.6 78 MIC90 (µg/ml) E. Coli Shigella spp 0.25 0.06 < 4 < 4Shigella spp Campylobacter 0.06 64 4 0.5 Tissue concentration: 10 100 x serum concentrationTissue concentration: 10 - 100 x serum concentration Macrophage & neutrophil
  16. 16. Clinical features of traveler’s diarrheaC ca ea u es o a e e s d a ea ≥ 3 unformed stools within 24 hours with at least 1 of the following: N iti bd i l iNausea, vomiting, abdominal pain Fever, bloody stool 2 – 3 days after arrival (90% within first 2 weeks) Onset: Duration: 3 – 5 days (90%) > 2 weeks (10%) Duration: 0 1 2 >3 Travel 0 1 2 >3 Weeks post-travelHome
  17. 17. Approach to Vibrio (curved)Approach to Cholera-like illness Vibrio (curved) TCBS (thiosulphate citrate bile salts sucrose agar) Vibrio cholerae Vibrio parahemolyticus Dept. of Microbiology, QMH
  18. 18. Vibrio cholerae ? Serotype Agglutination test: O1 & O139, Non O1 Dept. of Microbiology, QMH
  19. 19. The first imported case of cholera inp 2008 From Philippine Notification data (DH) 2003: 7003 2004: 5 2005: 5 2006: 1 2007: 3 2008: 1 (till 8 Apr 08) Oriental daily 8 Apr 2008
  20. 20. Cholera stool Treatment ofCholera stool 500 - 1000 ml / hr Treatment of watery diarrhea Rehydration Rehydration Rehydration Rehydration Rehydration Rehydration Lancet. 2004 Jan 17;363(9404):223-33
  21. 21. Approach to Cholera-like diarrhea RotavirusRotavirus (Age of extremities)
  22. 22. Norovirus virus Positive Control Negative Control Patient 1 2 113 bp RT-PCR for ORF1 of Norwalk virus Dept. of Microbiology, QMH
  23. 23. Minimum infective dose of viral gastroenteritis 1011 / g of stool Rotavirus 10 viral particles 3 x 107 / vomiting Norovirus 10 - 100 viral particles
  24. 24. Entamobea histolyticaEntamobea histolytica By Trichrome stain 10µm Dept. of Microbiology, QMH
  25. 25. Giardia intestinalis By Trichrome stain 10um Dept. of Microbiology, QMH
  26. 26. Before inoculation After inoculationAfter inoculation
  27. 27. Laribacter hongkongensis gen. nov. sp. nov.Laribacter hongkongensis gen. nov. sp. nov. M/54 Oxidase + Alcoholic cirrhosis & portal HT Empyema thoracis & bacteraemia Catalase + Urease + Arginine dihydrolase + S-shaped Gram-ve bacillus Growth g y Nitrate reduction + 25°C - 42°C 0-2% NaCl MacConkey agar Facultative anaerobic J Clin Microbiol. 2001 Dec;39(12):4227-32.
  28. 28. Cefoperazone (32 μg/ml) MacConkey agar: selective medium for Laribacter hongkongensisselective medium for Laribacter hongkongensis BA, aerobic 48 h CMA, aerobic 48 h48 h 48 h CCDA, aerobic 48 h CCDA, microaerophilic 48 h
  29. 29. Risk factors for gastroenteritis associated with L ib t h k iLaribacter hongkongensis Characteristics Patients with L Controls P valueCharacteristics Patients with L. hongkongensis GE (n=17) Controls without GE (n=34) P value Recent travel histories 10 2 <0 001Recent travel histories 10 2 <0.001 Consumption of fish within 3 days prior to onset of 16 19 <0.01 y p diarrhoea/interview Consumption of minced 5 1 <0 05Consumption of minced freshwater fish meat within 3 days prior to onset of diarrhoea/interview 5 1 <0.05 Lancet. 2004 Jun 12;363(9425):1941-7.

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