Foodborne and Waterborne Bacterial Diseases Chapter 11 Foodborne and Waterborne Bacterial Diseases

11.1 The Digestive System Has an Extensive Indigenous Microbiota The digestive system is composed of two separate categories of organs. Gastrointestinal (GI) tract Accessory digestive organs Chemical, mechanical, and cellular defenses protect the GI tract from pathogen colonization. Figure 11.02: The Human Digestive System

Figure 11.03A: Microbiota of the Digestive System. Our understanding of the human oral and GI microbiome is rapidly improving. the Human Gut Microbiome Initiative is helping to learn more about our gut microbiome. Figure 11.03A: Microbiota of the Digestive System.

Figure 11.05B: The Anatomy of a Tooth. 11.2 Bacterial Diseases of the Oral Cavity Can Affect One’s Overall Health Dental plaque is a biofilm, containing salivary proteins, food debris and bacterial cells and products. Dental caries (tooth decay) causes pain and tooth loss in affected individuals plaque building. dietary carbohydrates. acidogenic bacteria 50-100 million bacterial cells inhabit the tooth surface, called the dental pellicle. Figure 11.05A: The Anatomy of a Tooth. © BSIP/Photo Researchers, Inc. Figure 11.05B: The Anatomy of a Tooth.

Figure 11.07A: Dental plaque. A major cause of dental caries is Streptococcus mutans. They ferment dietary carbohydrates into acids. Fluoride and diet can prevent dental caries. Figure 11.07A: Dental plaque. Figure 11.06: Dental caries. © Dr. Tony Brain/Photo Researchers, Inc.

Figure 11.08B: Periodontal disease. Periodontal disease can arise from bacteria in dental plaque. Figure 11.08A: Gingivitis. Gingivitis develops when plaque builds up between teeth and gums. It is characterized by: ulcers and bleeding along the gingival margin. degradation of periodontal ligaments and bone. loosened or lost teeth. © Medical-on-Line/Alamy Images Figure 11.08B: Periodontal disease. © SPL/Photo Researchers, Inc.

Figure 11.09A: Foodborne Illness Surveillance. 11.3 Bacterial Diseases of the GI Tract Are Usually Spread Through Food and Water Gastroenteritis is an inflammation of the GI tract Intoxications are illnesses in which bacterial toxins are ingested with food and water. Infections are illnesses in which live bacterial pathogens are ingested and grow in the body. The incubation period is the time between: consumption of contaminated material. appearance of symptoms. Figure 11.09A: Foodborne Illness Surveillance. Data from: CDC

Clinical symptoms and duration of illness depend on: the toxin or microbe. the infectious dose. Demographics can make individuals more or less prone to food/waterborne illness. For example, age, immunocompromised patients or sanitary conditions

Figure 11.09B: Foodborne outbreaks. There are several ways foods or water become contaminated. Meat can be infected during improper slaughter procedure. Fruits and vegetables can be washed with contaminated water. Infected humans can contaminate food they handle through the fecal-oral route. Figure 11.09B: Foodborne outbreaks. Data from: CDC

Figure 11.01: Recent Cholera Outbreaks. Cross-contamination can occur: between foods via knife, cutting board, etc. Water contamination can occur by defecation of infected individuals in public water sources Improperly stored foods can contain large numbers of pathogens because of rapid multiplication Figure 11.01: Recent Cholera Outbreaks. Adapted from Waldor, M.K., Hotez, P.J., and Clemens,J.D. (2010) N Engl J Med 363 (24): 2279-2282.

11.4 Some Bacterial Diseases Are the Result of Foodborne Intoxications Food poisoning illnesses are the result of enterotoxins. Staphylococcus aureus causes staphylococcal food poisoning. Toxins are often consumed in protein-rich foods such as: meat and fish. dairy products. The enterotoxin causes gastroenteritis for several hours. Figure 11.10A: Staphylococcus aureus. © Eye of Science/Photo Researchers, Inc.

Figure 11.10B: Staphylococcus aureus typing. Food is often contaminated by: boils or abscesses on a handler’s skin. through sneezing. Incubation is 1-6 hours Proper handling, refrigeration, and heating help decrease the risk of contamination. Figure 11.10B: Staphylococcus aureus typing. Courtesy of Paul Gulig, Donna Duckworth and Julio Martin, University of Florida

Figure 11.11: Clostridium perfringens TEM. Clostridium perfringens causes clostridial food poisoning. C. perfringens commonly contaminated meat, poultry, and fish. Clinical symptoms require a high infectious dose and take 8–24 hours to appear. Bacillus cereus can cause diarrhea or vomiting. Infections usually occur from eating contaminated cooked grains. Figure 11.11: Clostridium perfringens TEM. © CNRI/Photo Researchers, Inc.

Clostridium botulinum causes the most dangerous foodborne intoxication. Botulism is caused by a neurotoxin that inhibits the release of the neurotransmitter acetylcholine preventing the contraction of muscles causing flaccid paralysis and respiratory arrest. Treated by antitoxins and life-support systems like ventilators. Prevented by heating foods before eating them for at least 10 minutes.

Other forms of botulism Wound botulism occurs when toxins are produced in anaerobic tissue of wounds. Infant botulism is the most common form of botulism in the US. It occurs when infants ingest endospores, commonly with honey causing floppy baby syndrome. They are treated by Penicillin. Botulinum toxins are used in Botox. Figure 11.12: Cosmetic Injection of Botulinum Toxin. © Michael N. Paras/age fotostock

11.5 GI Infections Can Be Caused by Several Bacterial Pathogens Bacterial GI infections have a longer incubation period than intoxications because bacterial cells must establish themselves in the body after ingestion. Bacterial gastroenteritis often produces an inflammatory condition. Dehydration is a common but serious complication of gastroenteritis. Figure MF11.01: A computer enhanced barium enema X-ray. © Scott Camazine/Alamy Images

Figure 11.13: Vibrio cholerae. Cholera can involve enormous fluid loss. Cholera is caused by Vibrio cholerae. V. cholerae are often consumed with raw oysters and water. The cells are susceptible to stomach acid. A large infectious dose is needed to colonize the intestines. Figure 11.13: Vibrio cholerae. © SAS/Alamy Images

Antibiotics and oral rehydration therapy are effective in treatment. Cholera toxin causes loss of fluid and electrolytes through diarrhea called rice water stools (up to 1 L/hour). If untreated, fluid loss thickens the blood, leading to shock and coma. Antibiotics and oral rehydration therapy are effective in treatment. Vaccines using dead V. cholerae are available. Preventable by clean water and food. Figure MF 11.04: Spread of cholera. Figure MM05: Vibrio cholerae.

E. coli diarrheas cause various forms of gastroenteritis. Escherichia coli is normally found in the human intestine, but certain serotypes are pathogenic. Transmission occurs through the fecal-oral route. “travelers diarrhea” lasts 3-7 days Figure 11.14: E. coli. © Stephanie Schuller/Photo Researchers, Inc.

Healthcare-associated infections Figure 11.15: Pseudomembra nous colitis. Clostridium difficile Associated with antibiotic use Major cause of pseudomembranous colitis Fecal transplant can cure 90% of patients with severe, long-term C. difficile infections © David M. Martin, M.D./Photo Researchers, Inc. Figure 11.04AB: Fecal Transplant. © Paul Gunning/Photo Researchers, Inc. © Stephanie Schuller/Photo Researchers, Inc.

Figure 11.16 Listeria monocytogenes. Listeria monocytogenes causes listeriosis through fecal contaminated food, water and milk. It primarily affects pregnant women, newborns, elderly and the immunocompromised causing a form of meningitis. Vibrio sp. causes seafood borne gastroenteritis. Intestinal Anthrax caused by eating contaminated or undercooked meat Figure 11.16 Listeria monocytogenes. Courtesy of Dr. Balasubr Swaminathan and Peggy Hayes/CDC

Figure 11.17: The incidence of typhoid fever. Several bacteria can cause an invasive gastroenteritis. Typhoid Fever involves a blood infection. It is caused by Salmonella enterica serotype Typhi (S. typhi). S. typhi is transmitted by the five Fs: Flies Food Fingers Feces Fomites It is acid resistant. It passes through the stomach to the small intestine. It causes ulcers, bleeding, and pain. Figure 11.17: The incidence of typhoid fever. Data from CDC, Summary of Notifiable Diseases, 2006.

Figure 11.18AB: Salmonella enterica SEM. Salmonella serotypes are often found in unpasteurized milk or poultry products. Transmitted by the fecal oral route or they can also be transmitted by chickens, turkeys, eggs, and pet turtles. © Kwangshin Kim/Photo Researchers, Inc. © Scimat/Photo Researchers, Inc. Figure 11.18AB: Salmonella enterica SEM.

Figure MM11: Shigella sonnei. Shigellosis (bacterial dysentery) occurs where sanitary conditions are lacking. Shigellosis is primarily caused by Shigella sonnei S. dystenteriae causes epidemics in the developing world Contaminated foods commonly include eggs, vegetables, shellfish, dairy. Shiga toxin production in the intestinal epithelium triggers gastroenteritis. Infection of the large intestine can lead to fatal dysentery. No vaccine is available. Figure MM11: Shigella sonnei.

Figure 11.19: Fresh Bagged Spinach. Enterotoxigenic E. coli (ETEC) penetrate the intestinal epithelium and produce a toxin that causes gastroenteritis. Enteropathogenic E. coli (EPEC) cause diarrhea in infants, particularly where sanitation is lacking. Enterohemorrhagic E. coli (EHEC) has shiga toxin in E. coli O157:H7 outbreaks Figure TC11: E. coli O157:H7. Figure 11.19: Fresh Bagged Spinach. © Jeff Chiu/AP Photos Courtesy of CDC

Figure 11.20: Campylobacter jejuni. Campylobacteriosis results from consumption of contaminated poultry or unpasteurized milk Campylobacteriosis is one of the most common causes of bacterial gastroenteritis in the US Campylobacter jejuni is transmitted through the fecal-oral route A rare immune reaction is Guillain-Barre syndrome causing paralysis Figure 11.20: Campylobacter jejuni. © Medical-on-Line/Alamy

Figure 11.21: Yersinia enterocolitica. Yersiniosis is an emerging foodborne illness caused by Yersinia enterocolitica Figure 11.21: Yersinia enterocolitica. Reprinted with permission from the American Society for Microbiology (ASM News, January 2002, p. 20-24.) Photo courtesy of Doctor Virginia L. Miller, University of North Carolina.

Figure 11.22: The progression of gastric ulcers. Gastric ulcer disease can be spread person to person. Helicobacter pylori is involved in gastric ulcers. It is unknown how H. pylori is transmitted, but it likely involves contaminated food or water. The bacteria produce urease, which in turn produces ammonia. Ammonia neutralizes acid in that area of the stomach, allowing the bacteria to survive. The ammonia, and an H. pylori cytotoxin destroy mucous-secreting cells. This creates a sore. © P. Hawtin/Photo Researchers, Inc. Figure 11.22: The progression of gastric ulcers.