V. B.Foodborne & Waterborne Bacterial Diseases 1.Foodborne Intoxications vs Infections 2.Botulism 3.Staphylococcal Food Poisoning 4.Clostridial Food Poisoning 5.Typhoid Fever 6.Salmonellosis 7.Shigellosis 8.Cholera 9.Diseases associated with Escherichia coli 10.Camphylobacteriosis and Helicobacteriosis

V. B. 1.Foodborne Intoxications vs Infections Foodborne intoxications: Caused by the exotoxin secreted by bacteria in contaminated food Foodborne infections: Caused by the ingestion of live bacteria that colonize the digestive tract

V. B. 2.Botulism Cause: Clostridium botulinum – Properties of the genus Clostridium Gram-positive rod Strictly anaerobic Spore-former Widely distributed, especially in soil – Important species: Clostridium botulinum Clostridium perfringins Clostridium tetani

V. B. 2.Botulism Transmission & Symptoms – Transmitted via contaminated food – Botulinum toxin: A neurotoxic exotoxin Heat sensitive Inhibits synaptic transmission at motor neuron end plates Causes flaccid paralysis Very deadly: Death due to respiratory & cardiac failure Treatment: Administration of antitoxin

V. B. 2.Botulism Transmission & Symptoms (cont.) – Other mechanisms of transmission: Wound botulism Animal botulism Infant botulism

V. B. 3.Staphylococcal Food Poisoning Cause: Staphylococcus aureus – Properties of the genus Staphylococcus Gram positive coccus in clusters Catalase positive – Two major species Staph. aureus is more virulent & is coagulase positive Staph epidermidis is more common & is coagulase negative Both are common skin & upper RT flora

V. B. 3.Staphylococcal Food Poisoning Transmission & Symptoms – Certain strains of Staph. aureus: Produce staphylococcal enterotoxin – Toxin is secreted in contaminated food – Causes abdominal pain, nausea, diarrhea, for a few hours – Staph. aureus enterotoxin is unusually heat-resistant

V. B. 4.Clostridial Food Poisoning Cause: Clostridium perfringins – Certain strains secrete an enterotoxic exotoxin Transmission & Symptoms – Similar to staphylococcal food poisoning, except that the clostridial enterotoxin is not as heat- stable

V. B. 5.Typhoid Fever Cause: Salmonella typhi – Properties of the genus Salmonella A member of the family Enterobacteriaceae Colon flora; sometimes carried asymptomatically Gram negative rods Facultatively anaerobic – Salmonella typhi Most virulent member of the genus

V. B. 5.Typhoid Fever Transmission & Symptoms – Transmission via oral route often associated with contact with infected persons, either symptomatic or carriers sewage flies

V. B. 5.Typhoid Fever Transmission & Symptoms – Invades intestinal epithelium tissue ulceration bloody stools but little diarrhea Blood invasion fever; delirium blood vessel hemorrhaging rose-colored spots on the abdomen bowel perforation gall-bladder infection

V. B. 6.Salmonellosis Cause: Salmonella serotypes – Serotypes of the genus Salmonella other than S. typhi – Hundreds of serotypes; species names exist but are often not reported – Examples Salmonella enteriditis Salmonella gallinarum Salmonella typhimurum

V. B. 6.Salmonellosis Transmission & Symptoms – Contaminated food Meat Poultry products Dairy products – Gastroenteritis Cramps Nausea Vomiting Diarrhea

V. B. 7.Shigellosis Cause: Shigella species – Genus Shigella A member of the family Enterobacteriaceae Colon flora; sometimes carried asymptomatically Gram negative rods Facultatively anaerobic – Species Shigella sonnei Shigella dysenteriae Shigella flexneri Shigella boydii

V. B. 7.Shigellosis Transmission & Symptoms – Transmission: Similar to salmonellosis – Gastroenteritis Often with watery diarrhea Sometimes with bloody stools: Dysentery

V. B. 8.Cholera Cause: Vibrio cholerae – Genus Vibrio Gram-negative curved bacteria comma-shaped facultatively anaerobic Normal flora in many animals – Notable Pathogenic Species Vibrio cholerae Vibrio parahaemolyticus

V. B. 8.Cholera Transmission & Symptoms – Transmission: Contaminated food – shellfish vermin livestock

V. B. 8.Cholera Transmission & Symptoms (cont.) – Gastroenteritis with extensive severe diarrhea Cholera enterotoxin Toxin blocks water reabsorption by inhibiting the anion active transport mechanism in large intestinal epithelium “Rice water” stools Dehydration & death – Recent epidemic due to spread of new drug- resistant strain

V. B. 9.Diseases associated with Escherichia coli Cause: Escherichia coli – Family Enterobacteriaceae – Gram-negative rods – Facultatively anaerobic – Widely distributed among humans & animals – Normal colon flora – Used as indicator of water & food contamination

V. B. 9.Diseases associated with Escherichia coli Transmission & Symptoms – Oral route Extremely common normal flora Different strains in different geographical regions Colonize gut in infancy – Infantile diarrhea – Traveler's diarrhea

V. B. 9.Diseases associated with Escherichia coli Transmission & Symptoms (cont.) – E. coli strain O157:H7 A rare, particular virulent & deadly strain Hemorrhagic E. coli disease Kidney damage in children

V. B. 10.Camphylobacteriosis and Helicobacteriosis Camphylobacter jejuni – Gram-negative spirillum – Microaerophilic – Normal flora of colon – Common cause of mild to moderate gastroenteritis

V. B. 10.Camphylobacteriosis and Helicobacteriosis Helicobacter pylori – Gram-negative spirillum – Microaerophilic – Can colonize the stomach lining underneath the protective mucous layer – Stomach irritation and ulcers

V. C.Soilborne Bacterial Diseases 1.Anthrax 2.Tetanus 3.Gas Gangrene 4.Leptospirosis 5.Listeriosis

V. C. 1.Anthrax Cause: Bacillus anthracis – Genus Bacillus – Gram-positive rods – Facultatively anaerobic – Spore-forming – Widely distributed in soil – Many species; Bacillus anthracis is the most important human pathogen of the group

V. C. 1.Anthrax Transmission & Symptoms – Transmission Contact with contaminated soil Livestock Through skin; wounds; abrasions Also through oral route or airborne – Skin anthrax – Intestinal anthrax – Pulmonary anthrax; “Woolsorter’s disease”

V. C. 2.Tetanus Cause: Clostridium tetani – Genus properties: See “Botulism” Transmission & Symptoms – Wounds; esp. deep or puncture wounds – Tetanospasmin: A neurotoxic exotoxin Acts as a cholinesterase inhibitor “Short-circuits” nerve synapses; esp. in the central nervous system Causes rigid paralysis – Treatment: Antitoxins plus muscle relaxants – Prevention: Vaccination with tetanus toxoid

V. C. 3.Gas Gangrene Often caused by Clostridium perfringins – Genus properties: See “Botulism” Transmission & Symptoms – Wounds; esp. deep wounds – Gangrene: Tissue death due to reduced oxygen to tissue Gas or moist gangrene: Gangrene accompanied by bacterial infection Swelling; tissue death; blackish discoloration

V. C. 4.Leptospirosis Cause: Leptospira interrogans – A spirochete – Found in soil contaminated with animal waste Transmission & Symptoms – Contact with contaminated soil or animals Often enters through the feet – Spreads to several organs, including liver, kidney, meninges – Jaundice may be present – May have bloody vomit

V. C. 5.Listeriosis Cause: Listeria monocytogenes – Genus Listeria – Small Gram-positive rods – Non-sporeforming – Found in soil; esp in soil contaminated with animal waste

V. C. 5.Listeriosis Transmission & Symptoms – Contact with contaminated soil – Also possibly transmitted via contaminated food – Listeric meningitis – Blood infection with high white count – Uterine infections; miscarriage or congenital damage

V. D.Arthropodborne Bacterial Diseases 1.Plague 2.Lyme Disease 3.Rocky Mt. Spotted Fever 4.Epidemic Typhus 5.Endemic Typhus

V. D. 1.Plague Cause: Yersinia pestis – Gram-negative, facultatively anaerobic rods – in Family Enterobactereaceae; however, not normally found in colon – Characterized by bipolar staining

V. D. 1.Plague Transmission & Symptoms – Vector: Fleas, esp. rodent fleas – Bubonic plague: Infection of lymph node tissue; swelling; hemorrhaging; buboes – Septicemic plague – Pneumonic plague – Cases of airborne transmission among humans have been noted

V. D. 2.Lyme Disease Cause: Borrelia burgdorferi – A spirochete – Transmitted by deer ticks – First noted in Northeastern US

V. D. 2.Lyme Disease Transmission & Symptoms – Vector: Ticks of the genus Ixodes (deer ticks); may be transmitted by both immature & mature ticks – Incubation period of several weeks – Initial symptoms Flu-like symptoms Rash: Erythema chronicum migrans (ECM) – Several weeks/months later Joint pain/swelling Arthritis-like symptoms Cardiovascular & nervous system damage

V. D. 3.Rocky Mt. Spotted Fever Cause: Rickettsia rickettsii – A rickettsia: Small, gram-negative bacterium Obligately intracellular parasite – Detected by serological testing, eg. the Weil-Felix test (Reaction of serum to Proteus OX19) Transmission & Symptoms – Vector: Ticks – Macropapipular rash begins on palms & soles then spreads to other parts of the body – High fever & other flu-like symptoms

V. D. 4.Epidemic Typhus Cause: Rickettsia prowasekii – Genus properties: See “Rocky Mt. Spotted Fever” Transmission & Symptoms – Vector: Human Louse – Epidemics; often in areas with reduced sanitation – High fever; high fatality rate – Rash begins on trunk of body & spreads to extremities

V. D. 5.Endemic Typhus Cause: Rickettsia typhi – Genus properties: See “Rocky Mt. Spotted Fever” Transmission & Symptoms – Vector: Fleas; esp. rodent fleas – Endemic in many areas – Often with mild or no symptoms

V. E.Sexually Transmitted Bacterial Diseases 1.Syphilis 2.Gonorrhea 3.Chlamydia 4.Chanchroid

V. E. 1.Syphilis Cause: Treponema pallidum – A spirochete – Cannot be cultured on lab medium – Detected microscopically or serologically

V. E. 1.Syphilis Transmission & Symptoms – Transmission: Sexual contact or congenitally – Primary Syphilis Few days after contact Hard Chancre – Secondary Syphilis Several weeks after chancre disappears Fever; flu-like symptoms Rash

V. E. 1.Syphilis Transmission & Symptoms (cont.) – Tertiary Syphilis Months or years later Gummae: Lesions on skin & mucous membranes Damage to internal organs Cardiovascular & central nervous system damage

V. E. 2.Gonorrhea Cause: Neiserria gonorrhoeae – Genus Properties: See “Neiserria meningitidis” Transmission & Symptoms – Transmission: Sexual contact or congenital – Urinary Tract Symptoms Urethritis: Burning sensation; discharge Cystitis; kidney infection – Male Reproductive Tract Symptoms Prostatitis Inflammation of epididymis & testes; sometimes sterility

V. E. 2.Gonorrhea Transmission & Symptoms (cont.) – Female Reproductive Tract Symptoms Uterine Infections Fallopian Tube inflammation; blockage; occasional sterility Pelvic Inflammatory Disease – Other Infections Gonococcal Eye Infections Respiratory Tract Infections

V. E. 3.Chlamydia Cause: Chlamydia trachomatis – Genus Properties A small, Gram-negative bacterium Obligately intracellular parasite; similar to Rickettsia – Occasionally carried subclinically as part of the normal vaginal flora

V. E. 3.Chlamydia Transmission & Symptoms – Very similar to gonorrhea: Often mistaken for gonorrhea – Important to distinguish because the treatment is different from gonorrhea – Identified by serological testing – Transmission: Sexual contact or congenital – Urinary and Reproductive Tract Symptoms – Respiratory Tract and Eye Infections

V. E. 4.Chanchroid Cause: Haemophilus ducreyii – Genus Properties: See Haemophilus influenzae – Haemophilus ducreyii is occasionally found among the vaginal flora or under the prepuce in males Transmission & Symptoms – Transmission: Sexual contact – Symptoms Painful soft chancre; sometimes mistaken for syphilis Urethritis; occasional pelvic inflammation

V. F.Miscellaneous Bacterial Diseases 1.Leprosy 2.Staphylococcal Infections 3.Pseudomonas aeruginosa Infections

V. F. 1.Leprosy Cause: Mycobacterium leprae – Genus Properties: See “Tuberculosis” – Cannot be cultured; detected by skin biopsy Transmission & Symptoms – Skin contact; not particularly contagious – Whitish skin lesions – Loss of sensation due to nerve damage – Disfiguration

V. F. 2.Staphylococcal Infections Cause: Staphylococcus aureus – Genus Properties: See “Staph. Food Poisoning” Transmission & Symptoms – Skin contact; opportunistic – Skin Infections Acne; boils; pimples Abscesses; carbuncles Impetigo Scalded Skin Syndrome – Toxic Shock Syndrome Septicemia & High fever

V. F. 3.Pseudomonas aeruginosa Infections Cause: Pseudomonas aeruginosa – Genus Pseudomonas Gram-negative rods Nonfermentative metabolism Most species are strictly aerobic Widely distributed in aquatic & moist soil environments Can contaminate moist aerated surfaces: water faucets; respiration equipment

V. F. 3.Pseudomonas aeruginosa Infections Transmission & Symptoms – Frequently an opportunistic or a nosocomial infection – Respiratory tract infections – Urinary tract infections – Infections in burn patients