Week 1 (negative + positive)

Pseudomonas Small Gram-negative rods with a single polar flagellum (monotrichous) primarily in soil, sea water, and fresh water; also colonize plants and animals Produce oxidase and catalase Example :1. Pseudomonas aeruginosaa. Frequent contaminant of ventilators, IV solutions, anesthesia equipmentb. Opportunistic pathogenc. Common cause of nosocomial infectionsd. Grapelike odore. Greenish-blue pigment (pyocyanin)

Bordetella pertussis Encapsulated coccobacillus Causes pertussis or whooping cough Acute respiratory syndrome Transmission by direct contact or inhalation of aerosols Virulence factorsa. receptors that recognize and bind to ciliated respiratory epithelial cellsb. Toxins that destroy and dislodge ciliated cells Loss of ciliary mechanism leads to buildup of mucus and blockage of the airways.

Enterobacteriaceae Family Coliform (lactose fermenting bacteria) Most frequent cause of diarrhea through enterotoxins All ferment glucose, reduce nitrates to nitrites, oxidase negative, and catalase positive. Antigenic Structures and Virulence Factors1. H flagellar Ag2. K capsule and/or fimbrial Ag3. O somatic or cell wall Ag all have4. Endotoxin 5. Exotoxins Example :1. E. Coli Enterotoxigenic Enteroinvasive Enteropathogenic Enterohemorrhagic Noncoliform Lactose-Negative Enterics Salmonella and shigella

Salmonella typhi1. Flagellated; ferments glucose 2. Resistant to chemicals bile and dyes 3. cause of typhoid fever Bacillus enters with ingestion of fecally contaminated food or water Asymptomatic carriers Bacilli adhere to small intestine, cause invasive diarrhea that leads to septicemia chloramphenicol or sulfa-trimethoprim treatments Shigella and Bacillary Dysentery1. S. dysenteriae, S. sonnei, S. flexneri and S. boydii 2. Invades villus of large intestine, can perforate intestine or invade blood3. Enters Peyers patches instigate inflammatory response; endotoxin and exotoxins 4. Treatment fluid replacement and ciprofloxacin and sulfa-trimethoprim Yersinia pestis and Plague1. tiny, Gram-negative rod, unusual bipolar staining and capsules2. Virulence factors capsular and envelope proteins protect against phagocytosis and foster intracellular growth coagulase, endotoxin, murine toxin3. Flea vectors bacteria replicates in gut, coagulase causes blood clotting that blocks the flea esophagus4. Pathology Bubonic, bacillus multiplies in flea bite, enters lymph, causes necrosis and swelling called a bubo in groin or axilla Septicemic, virulence factors cause intravascular coagulation subcutaneous hemorrhage and purpura - black plague Pneumonic

Spirochetes Treponema Treponema pallidum (Syphilis) Thin, regular, coiled cells Live in the oral cavity, intestinal tract, and perigenital regions of humans and animals Sexually transmitted and transplacental Bind to epithel multiplies penetrate capillaries

Curviform Gram Negative Bacteria and Enteric Diseases Vibrio comma-shaped rods, single polar flagellum Vibrio cholerae, possess unique O and H Ags. Infects mucous barrier of small intestine, noninvasive Cholera toxin causes electrolyte and water loss through secretory diarrhea, rice water stool; resulting dehydration leads to muscle, circulatory, and neurological symptoms Helicobacter spirochete with tight spirals and endoflagella Produces urease which converts ammonium and bicarbonate into alkaline products that neutralize stomach acid

The Chlamydiaceae Chlamydia trachomatis Small, Gram-negative cell wall attacks the mucous membranes of the eyes, genitourinary tract and lungs STD second most prevalent STD; urethritis, cervicitis, salpingitis (PID)

Haemophilus H. influenza, satellitism around and between the large, white, hemolytic staphylococci

X-factor ( hemin): Heat-stable substance V-factor (NAD): Heat- labile, coenzyme I, nicotinamide adenine dinucleotide, found in blood or secreted by certain organisms

Neisseriaceae Gram-negative cocci Capsules on pathogens Pili Strict parasites, do not survive long outside of the host Aerobic or microaerophilic Oxidative metabolism Produce catalase and cytochrome oxidase Pathogenic species require enriched complex media and CO2. Genera include Neisseria, Moraxella, Acinetobacter. 2 primary human pathogens: Neisseria gonorrhoeae STD Virulence factors: pili, other surface molecules for attachment; slows phagocytosis IgA protease cleaves secretory IgG Infection is asymptomatic in 10% of males and 50% of females. Males urethritis, yellowish discharge, scarring and infertility Females vaginitis, urethritis, salpingitis (PID) mixed anaerobic abdominal infection, common cause of sterility and ectopic tubal pregnancies Extragenital infections anal, pharygeal, conjunctivitis, septicemia, arthritis Gonorrhea in Newborns Infected as they pass through birth canal Eye inflammation, blindness Gram stain Gram-negative intracellular (neutrophils) diplococci from urethral, vaginal, cervical, or eye exudate

Neisseria meningitides Virulence factors: capsule pili IgA protease endotoxin 12 strains; serotypes A, B, C cause most cases

Other Gram-negative Cocci and Coccobacilli Genus Branhamella Branhamella catarrhalis found in nasopharynx: significant opportunist in cancer, diabetes, alcoholism Genus Moraxella bacilli; found on mucous membranes Genus Acinetobacter Gram-negative bacilli; nonliving reservoir; source of nosocomial infections