TORTORA • FUNKE • CASE Microbiology AN INTRODUCTION EIGHTH EDITION B.E Pruitt & Jane J.
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TORTORA • FUNKE • CASE Microbiology AN INTRODUCTION EIGHTH EDITION B.E Pruitt & Jane J. Stein Chapter 25, part B Microbial Diseases of the Digestive System PowerPoint® Lecture Slide Presentation prepared by Christine L. Case Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Escherichia coli Gastroenteritis • Occurs as traveler's diarrhea and epidemic diarrhea in nurseries • 50% of feedlot cattle may have enterohemorrhagic strains in their intestines • Enterohemorrhagic strains such as E. coli O157:H7 produce Shiga toxin • O = cell wall antigen • H = flagellar antigen Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Campylobacter Gastroenteritis • Campylobacter jejuni • Usually transmitted in cow's milk Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Helicobacter Peptic ulcer disease • Treated with antibiotics • H. pylori causes stomach cancer Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 11.11 Helicobacter Peptic ulcer disease Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.13 Yersinia Gastroenteritis • Y. enterocolitica and Y. pseudotuberculosis • Can reproduce at 4°C • Usually transmitted in meat and milk Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Clostridium perfringens Gastroenteritis • Grow in intestinal tract producing exotoxin Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Bacillus cereus Gastroenteritis • Ingestion of bacterial exotoxin produces mild symptoms Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Mumps • Mumps virus • Enters through respiratory tract • Infects parotid glands • Prevented with MMR vaccine Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.14 Hepatitis • Inflammation of the liver • Hepatitis may result from drug or chemical toxicity, EB virus, CMV, or the Hepatitis viruses Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Hepatitis Transmission Causative agent Chronic liver disease Vaccine Hepatitis A Fecal-oral Picornaviridae No Inactivated virus Hepatitis B Parenteral, STD Hepadnaviridae Yes Recombinant Hepatitis C Parenteral Filoviridae Yes No Hepatitis D Pareteral, HBV coinfection Deltaviridae Yes HBV vaccine Hepatitis E Fecal-oral Caliciviridae No No Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Table 25.1 Hepatitis B Virus Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.15 Viral Gastroenteritis • Rotavirus • 3 million cases annually • 1-2 day incubation, 1 week illness • Norovirus • 50% of U.S. adults have antibodies • 1-2 day incubation. 1-3 day illness • Treated with rehydration Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.17 Mycotoxins • Mycotoxins are produced by some fungi: • Claviceps purpurea • Grows on grains • Produces ergot • Toxin restricts blood flow to limbs; causes hallucination • Aspergillus flavus • Grows on grains • Produces aflatoxin • Toxin causes liver damage; liver cancer Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Giardiasis • Giardia lamblia • Transmitted by contaminated water • Diagnosed by microscopic examination of stool for ova and trophozoite • Treated with metronidazole Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.18 Cryptosporidiosis • Cryptosporidium parvum • Transmitted by oocysts in contaminated water • Diagnosed by acid-fast staining of stool or presence of antibodies by FA or ELISA • Treated with oral rehydration Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 25.19 Cyclospora Diarrheal Infection • Cyclospora cayetanensis • Transmitted by oocysts in contaminated water • Diagnosed by microscopic examination for oocysts • Treated with trimethoprim and sulfamethoxazole Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Amoebic Dysentery • Entamoeba histolytica • Amoeba feeds on RBCs and GI tract tissues • Diagnosis by observing trophozoites in feces • Treated with metronidazole Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Amoebic Dysentery Figure 25.20 Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Amoebic Dysentery Figure 12.18b Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings