8 There have been instances in which a surgeon was using spark producing instruments to remove intestinal polyps and a small explosion occurred. What ignited? 25-1How are normal microbiota confined to the mouth and large intestine? 25-2
9 Bacterial Diseases of the Mouth Learning Objective25-3 Describe the events that lead to dental caries and periodontal disease.
15 Bacterial Diseases of the Mouth PathogenDental cariesStreptococcus mutansPeriodontal diseasePorphyromonas spp.Acute necrotizing gingivitisPrevotella intermedia
16 Diseases in Focus: Bacterial Diseases of the Mouth Can you identify infections that could cause persistent sore, swollen, red, or bleeding gums, as well as tooth pain or sensitivity and bad breath?
17 Why are “sugarless” candies and gum, which actually contain sugar alcohols, not considered cariogenic (causing caries)? 25-3
18 Diseases of Lower Digestive System Learning Objective25-4 List the causative agents, suspect foods, signs and symptoms, and treatments for staphylococcal food poisoning, shigellosis, salmonellosis, typhoid fever, cholera, gastroenteritis, and peptic ulcer disease.
19 Diseases of Lower Digestive System Infection: Growth of a pathogenIncubation is from 12 hours to 2 weeksFeverIntoxication: Ingestion of toxinSymptoms appear 1 to 48 hours after ingestionGastroenteritis: Diarrhea, dysenteryTreatment: Oral rehydration therapy
21 Events in Staphylococcal Food Poisoning Figure 25.6
22 Shigellosis (Bacillary Dysentery) PathogenShigella spp.SymptomsTissue damage and dysenteryIntoxication/InfectionInfectionEndotoxin and Shiga exotoxinDiagnosisIsolation of bacteriaTreatmentQuinolones
23 Invasion of Intestinal Wall by Shigella Figure 25.7
31 Vibrios Cholera Noncholera vibrios Vibrio cholerae serotypes that produce cholera toxinToxin causes host cells to secrete Cl–, HCO–, and waterNoncholera vibriosUsually from contaminated crustaceans or mollusksV. cholerae serotypes other than O:1, O:139, eltorV. parahaemolyticusV. vulnificus
33 Vibrio cholerae O:1 and O:139 V. vulnificus DiseaseCholeraNoncholera vibriosPathogenVibrio cholerae O:1 and O:139V. parahaemolyticusV. vulnificusSymptomsDiarrhea with large water lossCholera-like diarrhea, but generally milderRapidly spreading tissue destructionIntoxication/InfectionCholera toxin (exotoxin)Infection, enterotoxinInfection, siderophoresDiagnosisIsolation of bacteriaTreatmentRehydration; doxycyclineRehydration; antibioticsAntibiotics
34 Escherichia coli Gastroenteritis Pathogenic E. coliAttach to intestinal cells with fimbriaeProduce toxinsMay aggregate
35 Escherichia coli Gastroenteritis DiseaseTraveler’s DiarrheaSTECPathogenEnterotoxigenic, enteroinvasive, enteraggregative E. coliShiga-toxin-producing E. coliSymptomsWatery diarrheaShigella-like dysentery; hemorrhagic colitis and hemolytic uremic syndrome
40 Yersinia Gastroenteritis PathogenY. enterocolitica, Y. pseudotuberculosisSymptomsAbdominal pain and diarrhea, usually mild; may be confused with appendicitisIntoxication/InfectionInfectionEndotoxinDiagnosisBacterial culture; serotypingTransmittedMeat, milk
41 Clostridium and Bacillus Gastroenteritis PathogenC. perfringensC. difficileB. cereusSymptomsDiarrheaDiarrhea to colitisNausea and vomiting; diarrheaIntoxication/InfectionInfectionExotoxinIntoxicationDiagnosisIsolation of bacteriaCytotoxin assay
42 Clostridium and Bacillus Gastroenteritis PathogenC. perfringensC. difficileB. cereusTransmittedMetronidazole;discontinue other antibiotic therapySource of InfectionMeatsElimination of normal microbiotaRice dishes
43 Salmonellosis and typhoid fever are caused by closely related organisms. Why was typhoid fever almost entirely eliminated in developed countries by modern sewage treatment whereas salmonellosis has not been? 25-4
44 Diseases in Focus: Bacterial Diseases of the Lower Digestive System An 8-year-old boy had diarrhea, chills, fever (39.3º C), abdominal cramps, and vomiting for 3 days. The next month, his 12-year-old brother experienced the same symptoms. Two weeks before the first patient became ill, the family had purchased a small (10 cm) red-eared slider turtle at a flea market.Can you identify infections that could cause these symptoms?
45 Viral Diseases of the Digestive System Learning Objectives25-5 List the causative agents, modes of transmission, sites of infection, and symptoms for mumps.25-6 Differentiate hepatitis A, hepatitis B, hepatitis C, hepatitis D, and hepatitis E.25-7 List the causative agents, mode of transmission, and symptoms of viral gastroenteritis.
46 Viral Diseases of the Digestive System MumpsViral GastroenteritisPathogenMumps virusRotavirusNorovirusSymptomsSwollen parotid glandsVomiting, diarrhea, 1 wkVomiting, diarrhea, 2–3 daysIncubation16–18 days1–3 days14–48 hrDiagnosisEIAPCRTreatmentPreventive vaccineOral rehydration
51 Applications of Microbiology: A Safe Blood Supply Nucleic acid testing (NAT) is used to test donated blood and plasma:HCVHIVWest Nile virusVirus-inactivation is used on plasma
52 Diseases in Focus: Viral Hepatitis After eating at one restaurant, 355 people were diagnosed with the same hepatitis virus.Can you identify infections that could cause these symptoms?
53 Diseases in Focus: Viral Diseases of the Digestive System An outbreak of diarrhea began in mid-June, peaked in mid-August, and tapered off in September. A clinical case was defined as diarrhea (three loose stools during a 24-hour period).Can you identify infections that could cause these symptoms?
54 Why is mumps included with the diseases of the digestive system? 25-5 Of the several hepatitis diseases, HAV, HBV, HCV, HDV, and HEV, which two now have effective vaccines to prevent them? 25-6Two very common causes of viral gastroenteritis are caused by rotaviruses and noroviruses. Which of these now can be prevented by a vaccine? 25-7
55 Fungal Diseases of the Digestive System Learning Objective25-8 Identify the causes of ergot poisoning and aflatoxin poisoning.
56 Mycotoxin Intoxications DiseaseErgot PoisoningAflatoxin PoisoningPathogenClaviceps purpureaAspergillus flavusSymptomsReduced blood to limbsLiver cirrhosis; liver cancerIntoxication/InfectionMycotoxin in grainMycotoxin in foodDiagnosisSclerotia in foodImmunoassay for toxin in foodTreatmentNone
57 What is the connection between the occasional hallucinogenic symptoms produced by ergot poisoning and a modern illicit drug? 25-8
58 Protozoan Diseases of the Digestive System Learning Objective25-9 List the causative agents, modes of transmission, symptoms, and treatments for giardiasis, cryptosporidiosis, Cyclospora diarrheal infection, and amoebic dysentery.
62 Cryptosporidium hominis in the U. S. Clinical Focus, p. 355
63 Cryptosporidiosis Pathogen Cryptosporidium hominis Symptoms Self-limiting diarrhea; may be life-threatening in immunosuppressed peopleReservoirCattle; waterDiagnosisAcid-fast stain; FA; ELISATreatmentOral rehydration
64 Cyclospora Diarrheal Infection PathogenCyclospora cayetanensisSymptomsWatery diarrheaReservoirHumans; birdsDiagnosisMicroscopyTreatmentTrimethoprim and sulfamethoxazole
67 Is giardiasis caused by ingestion of a cyst or an oocyst? 25-9
68 Helminthic Diseases of Digestive System Learning Objective25-10 List the causative agents, modes of transmission, symptoms, and treatments for tapeworms, hydatid disease, pinworms, hookworms, ascariasis, and trichinellosis.
69 Worldwide Prevalence of Helminthic Diseases Figure 25.20
84 Q&AThe United States frequently imports cheese and wine from France. In return, the United States exports horses to France. What does this have to do with the disease of trichinellosis?
85 What species of tapeworm is the cause of cysticercosis? 25-10
86 Diseases in Focus: Fungal, Protozoan, and Helminthic Diseases Public health officials in Pennsylvania were notified of cases of watery diarrhea with frequent, sometimes explosive, bowel movements among persons associated with a residential facility. The disease was associated with eating snow peas.Can you identify infections that could cause these symptoms?
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