Micro Block 2

• Genus: Straphylococcus
• Gram Positive
• Non Flagellated
• Easily grown on most media
• No Endospores
• Facultative anaerobes
• Some have Capsules; normal flora of skin
• Pathogen: Straphylococcus aureus

• Found in the nares of healthy people. (Nasal carriers) Autoinfections from nares and skin.
• Nosocomial infections
• Very resistant to drying
• Now resistant to many antibiotics
• coagulase + mannitol agar

• Selective - 7.5% NaCl
• Differential - Staphylococcus aureus ferments mannitol. dye added which turns yellow in acid pH

virus of bacteria

• Can be done in broth: no bacterial growth
• Can be done on agar plate streked with bacteria: look for plaques

• Straphlococcus aureus toxin
• Partially destroys heme molecule. BAP green
• Destroys WBCs, platelets - Necrosis
• Punctures host cell membrane with leakage

• toxic shock syndrome
• fever, malaise, major organ damage

• Major cause of food poisoning (2-3 hours afer meal)
• Nausea, vomiting, dizziness
• usually lasts several hours
• resistant to boiling and gastric pH
• get from pyogenic lesion on foot handler

• exfoliates skin layers
• *Stratum spinosum and stratum granulosum)
• Scalding of skin of skin (shedding in layers)

fibrin clots formed protects bacteria from phagocytosis

Hemolysins, Haluronidase, Nucleases, Lipases, Proteases

• Teichoic acid in CW binds to host CM. Adhesion.
• Usually there is low infectivity. Need trauma, foreign objects, etc.
• Convict study:
• 10^5- 10^6 intradermal bacteria required to cause infection.
• If talcum powder is applied to skin, less than 100 cells cause infection (due to dry environment).
• Surface protein A - helps the bacteria bind to host’s
• cells

boil. Deep pus filled lesion

a necrotic infection of skin and subcutaneous tissue composed of clusters of furuncles

pus, mainly on hands and feet

• Intradermal splitting of epidermis between the stratum spinosum and stratum
• granulosum
• Caused by exfoliatin toxins.



• 1980s tampons
• renal and liver damage
• fever, vomiting, diarrhea, muscle pain, sore throat
• many women have S. aureus in normal vagina flora
• eradicated by making tampons allow air movement

• Food preparer had S. aureus lesions on hands
• Food not refrigerated (picnics)
• potato salad and creamy dishes
• acute vomiting and diarrhea usually within 2-3 hours
• Prostration - collapse: an abrupt failure of function or complete physical exhaustion
• recovery usually rapid

• antibiotic susceptibility tests
• proper antibiotic
• drainage of pyogenic skin lesions

• Washing clothing and bedding with water above 70C
• Wash skin with hexachlorophane soaps, etc.
• Nasal creams with antibiotics

• gram stains of pyogenic lesions (gram +)
• hemolysis on blood agar plate (BAP)
• All straphylococci are catalase +
• only S. aureus is coagulase +
• Disc Sensitivity Test or antibiotic susceptibility test

• Coagulase Negative
• flora of skin, nares, ears, etc.
• usually opportunisitic
• now with catheters and prosthetic devices, they are important nosocomial infections (bladder infections)
• Some strains secrete slime (similar to capsule) which help them adhere to host's cells
• if on prosthetic device, the device must be removed

• coagulase negative
• saprophyte - organism living on dead animals or vegetation found in environment
• opportunist
• uropathogen

• most are resistant to many antibiotoics (staphylococci)
• do disc sensitivity test

• commensals - living on an organism without harming it
• free living
• Gram positive
• Aerobes - usually facultative, some obligate
• Opportunist
• includes: micrococcus, tetracoccus, sarcina (all coagulase negative and catalase positive)
• pathogenesis - similar to coagulase negative staphylococci

• Gram Positive
• Grow best on enriched media
• Normal flora of oral cavity, nasopharynx, and GI tract
• 1 micrometers
• chains of 30 or so cells
• non-acid fast, non-motile, some have capsules
• grow best on blood agar. Look for type of hemolysis:
• -alpha = green color. Partial lysis heme
• -beta = clear color. Complete lysis heme
• catalase negative
• aerobic to facultative anaerobic
• the obligative anaerobic streptococci are now placed in the genus peptostreptococcus

acute infections that can cause rheumatic fever and acute glomerulonephritis

neonatal sepsis and meningeal infections

pnemonia and meningitis

• these have Lancefield antigens
• Often cause purulent infections
• often speciated by type of hemolysis and enzymes
• most human pathogens: pyogenic groups A and B

• only 1 species = S. pnemoniae
• No Lancefield group antigens
• unusual because it can be diplococcus
• polysaccharide capsule
• alpha hemolytic
• 80+serotypes

• No Lancefield antigens
• alpha hemolytic
• no casular antigens
• normal oral flora
• almost never pathogenic
• several species: S. salivarius, S. mitis

• Like viridans, but NOT hemolytic
• assigned descriptive terms: non - hemolytic streptococci, microaerophilic streptococci
• almost never pathogenic

• most are beta hemolytic
• strept throat
• obtained by droplet infection
• group A streptococcal

• skin infection. often co - infected with Staphylococcus
• pinpoint blisters that are followed by dry scabs
• usually associated with poor hygiene (orphanage)
• obtained by direct contact or fomite
• beta hemolytic
• group A streptococcal

• skin infection spreading into a red lesion with edema
• associated with fever
• obtained by direct contact or fomite
• toxins released in blood could cause serious problems
• beta hemolytic
• group A streptococcal

• nosocomial
• diffiucult to treat due to antibiotic resistance
• pyogenic lesions present
• must do antibiotic disc sensitivity tests
• group A streptococcal

• puerpera - women that has just parturated
• infections enters mother following umbilical cutting
• usually associated with home - births (midwife, etc.)
• group A streptococcal

• focus is upper respiratory tract
• toxins travel throughout body in blood
• key diagnostic criteria: fever, scarlet red skin color, strawberry tongue
• group A streptococcal

• symptoms are similar to staph toxic shock syndrome
• obtained by droplet infection
• toins spread from lungs to major organ systems (lethal)
• super antigen
• Group A streptococcal

• complication of pharyngitis (less than 1%)
• cardiac failure usually cause of fatality
• theories of infection process
• 1. strept fragments attatch to cardiac muscle and antibodies are made which destroy cardiac muscle (autoimmune disease)
• 2. Strept grow in throat and antibodies made which react with certain proteins in heart similar to strept. Antibodies destroy heart tissue

• complication of pharyngitis (less than 1%)
• several theories explain
• sticking of antibodies glomerular basement membrame
• two theories of infection process:
• 1. antigenic strept fragments attach to glomerular basement membrane and antibodies are made which destroy this bm. Autoimmune disease
• 2. strept grow in throat and antibodies made which react with certain proteins in kidney similar to strept. antibodies destroy glomerular bm

• throat swab on anaerobic BAP
• beta hemolysis
• identify Lancefield group by serology
• Most are inhibited by bacitracin
• use bactracin discs

• example is S. agalactiae
• Leading cause of neonatal sepsis and meningitis
• colonizes respiratory tract and associated with pyogenic infections at non - respiratory sites (skin)
• Puerperal fevers
• infections associated with surgery (prosthetics) or gynecological manipulations (IUD, etc.)

• occasionally produce respiratory, skin, wound, soft tissue, and genital infections that may resemble groups A & B
• Bacteremia with S. bovis is associated with colon cancer

• lancet - shaped gram + diplococcus (viral infection may have caused shape change) & streptococcus
• virulent strains have capsule
• alpha hemolytic
• bile solubility test distinguishes S. pneumoniae from the alpha hemolytic veridans streptococci

• MCC: bacterial pnemonia - mortality is high for people over 50 (and before antibiotics); many carriers
• predisposing factors: alcoholism, diabetes mellitus, and renal diseases
• huge capsule with many enzymes and toxins
• 80+ serotypes
• antibodies of S. pneumoniae cross react with capsule of Klebsiella pnemoniae & Haemophilus pnemoniae (both Gram - rods)

• Enterococcus faecalis
• Lancefield group D antigens
• Gram + streptococci (shape)
• DNA homology studies now separate them from the streptococci (genus). Former name was Streptococcus faecalis
• present in intestinal tract. Fecal contamination
• Grow on ile and high salt
• Many resistant to antibiotics
• some are hemolytic; some are non - hemolytic
• opportunistic

• facultative aerobes
• no spores: not motile
• catalase (+)
• Gram positive, twisted rods
• V or L shape

• missing viral - induced toxin genes
• opportunists
• commensals of pharynx, nasopharynx, distal urethra, skin

• selective media = tellurite (black colonies due to reduction of tellurite)
• gram stains and test for enzymes
• transmission: droplet infection, direct contact, fomites
• convalescent pharyngeal or nasal carriers
• mainly occurs now in developing tropical countries

• gene for toxin is contained in a lysogenic phage
• many local and systemic effects of the toxin
• inhibits protein synthesis and binds to CM of host cells
• toxin is highly antigenic
• diphtherioids missing viral - induced toxin genes

• have a beaded appearance
• beads - consist of granules of a highly polymerized phosphate that is a storage mechanism for high - energy phosphate bonds
• granules stain metachromatically (dye that stains the rest of the cell blue will stain the granules red (methylene blue)

• pharyngitis, malaise, fever
• pseudomembrane (gray - white) - due to toxin activity acting like a strong acid, leaving gray - white scar tissue
• bullneck - cervical nodes, adenoditis, edema
• complications and lethal effects caused by respiratory obstruction or systemic effects of the toxin
• toxin in the circulatory system will damage organs (heart, nervous, system)
• organism remains in throat, toxins goes to blood, from there it can affect the skin causing pustules and lesions

• symptoms: pseudomembrane and bullneck
• selective media: tellurite agar (patients coughs onto plate)
• gram + twisted rods
• enzymes: many - lactase, maltase, etc.
• serology: antibody assays after 1 week

• antitoxin, which should be given immediately on the basis of clinical impression because there is a delay in laboratory diagnostic procedures
• toxin binds rapidly to cells and can not be neutralized by antitoxin. function of antitoxin is to neutralize any unbound toxin in blood
• because the antitoxin is made in the horse, the patient must be tested for hypersensitivity and medications for the treatment of serum sickness must be available

• immunization - DPT vaccine (contains diphtheria toxoid, tetanus toxoid, and acellular pertussis vaccine (purified protein from Bordetella pertussis))
• immunized persons may become infected because their antibodies are against a toxoid. however their disease is mild

• listeriosis
• gram + rods (v or l shaped)
• beta hemolytic
• catalase (+)
• facultative anaerobes
• motile - moves by tumbling (corynebacteria are not motile)
• widely spread among wild and domesticated animals
• found in intestines
• food - borne transmission (milk)
• mostly obtained from unpasturized milk products
• can grow at 4 degrees C and non-immune macrophages
• enter macrophage by endocytosis
• once inside cytoplasm of host cell, it stimulates the rearrangement of the host's actin fibers
• pseudopods form in host cell with extension to adjacent cells with the spread of Listeria (actin rockets)

• spread often by unpasturized milk or unwashed, raw vegetables grown in fields with animal fertilizer
• symptoms mimic other diseases: meningitis, bacteremia, endocarditis, urethritis, conjunctivitis
• high incidence in renal transplants. Causes meningitis and sepsis in newborns and immunosuppressed adults
• carriers - many people highly immune

• may be found in the GI tract and female genital tract
• transmission may be across placenta or by contact during parturition
• outbreaks related to unpasturized milk or milk products (cheese)
• NO VACCINE

• Gram+ rods
• in animals and decaying matter
• traumatic inoculation of mo into skin produces erysipeloid (red, painful, slow spreading erythematous swelling of the skin)
• also caused by Group A Streptococcus
• Occupational disease of fisthermen, butchers, veterinarians, and animal handlers

• Gram+ rods
• spores (position used to speciate); aerobic
• some are motile
• most: saprophytes

• anthrax
• Gram+ "bamboo rods" with square ends
• Medusa colonies
• glutamate capsule --> tendency to form chains
• elliptical central spore
• non-motile; non-hemolytic

• acquired through breaks in skin or mucous membranes; also through inhaling or ingesting
• spread by spores in soil from animal feces
• affected animals often develop fatal septicemic disease
• occupational disease (goat handler)
• pathogenesis: capsule & exotoxins
• clinical: 2-5 incubation time; initial lesion is erythematous papule, "redness of the skin due to congestion of a capillary"
• often mistaken for an insect bite
• papule usually progresses through vesicular and ulcerative stages (7-10 days); form black eschar (scab) - lesion usually heals
• less commonly - disease progresses with massive local edema, toxemia, bacteremia, and is fatal if untreated

• inhalation of spores from animal (sheep)
• pnemonia - like disease
• focus in lungs then spreads to body

ingesting raw or undercooked meat containing spores

• smears show large gram-positive rods in chains
• spores usually not seen in smears of exudate
• colonies form on BAP aerobically
• not motile; but other bacilli are usualy motile
• rise in antibody titer in agglutination test is diagnostic
• treatment: penicillin G and other antibiotics are effective. strains usually not resistant to antibiotics
• prevention: sterilizing dead animals and animal products from areas of endemic infections
• people at risk can be immunized with cell-free vaccine

• Gram+ rods
• food poisoning
• spores
• opportunist
• pyrogenic toxin causes food poisoning
• survive steaming and rapid frying
• spores germinate when rice is kept warm for many hours (re-heated fried rice)
• clinical findings: short incubation period (3 hrs - nausea and vomiting and similar to staphylococcal food poisoning )
• long incubation period (18 hrs - watery, non-bloody diarrhea and resembles clostridial gastroenteritis)
• prevention: cooked rice should not be kept at room temperature or warm for long periods

• lack cytochromes (use O2 as final electron acceptor)
• lack catalase and peroxidases - enter body in mixed cultures
• flora are usually harmles ->however, tissue devitalized by trauma, malignancy, etc -> life threatening
• four groups: clostridium, bacteroides, fusobacterium, peptostreptococcus

• gram+ rods
• endospores
• some are motile
• found in soil with feces and in large intestines of animals
• diseases: gas gangrene, tetanus, botulism, toxic enterocolitis

• gram- rods
• no spores
• pleomorphic
• normal flora in the oral cavity and colon

• gram- rods
• fusiform shape
• normal flora of oral cavity, colon and female genital tract. Abcesses of oral cavity and lesions of gums and pharynx
• distinguished from bacteroides by metabolic end products. different enzymes

• Gram+ streptococcus
• normal flora of upper aliementary tract, upper respiratory tract and lower intestinal tract
• rarely pathogenic
• obligative anerobes (most strept. are facultative)

• gram+ rods
• non-motile; capsule
• spores in soil; vegetative cells in colon and vagina
• 4 major and 9 minor exotoxins
• 5 serotypes based on toxins (A-E). Type A most impt.

• food poisoning caused by exotoxin
• alpha toxin = hydrolyzes lecithin and distrupts cell membrane; alpha hemolytic
• beta toxin = alters capillary permeability and is toxic to cardiac muscle; beta hemolytic
• 8-24 hour incubation
• nausea, abdominal pain, diarrhea, rarely vomiting. Meat dishes (stews, gravy)
• spores survive initial cooking

• less virulent strains
• wound infection with gas (H2S)
• less severe than gas gangrene

unsanitary abortions

• C. perfringens, C. novyi, C. septicum -> species causing gas gangrene
• acquire from deep wounds (spores) produces gas (H2S) with a putrid smelling leaking pus
• Eventually tears open skin
• treatment: minor surgery, antitoxin, antibiotics

• gram+ rods
• drumstick or tennis racket with terminal spores
• motile
• found in manured soil
• large intestines of animals
• neurotoxic exotixin (tetanospasmin) made by genes on plasmid
• DPT vaccine (2,4,6,18 monts, 4 years)with booster every 10 years
• diphtheria toxoid, pertussis pieces cells, tetanus toxoid

• transmission: soil through wounds, injecting drugs, neo-natal tetanus - enters through a contaminated umbilicus or circumcision wound
• pathogenesis: tetanus toxin (tetanospasmin) is an exotoxin (polypeptide) and produced by clostridium tetani at the wound site
• toxin is carried to the CNS where it binds to ganglioside receptors and blocks the release of inhibitory mediators at spinal synapses
• tetanus toxin and botulinum toxin are among the most toxic substances known; proteases that cleave proteins involved in mediator release
• clinical: violent muscle spasms; lockjaw due to rigid contraction; facial grin known as "risus sardonicus"
• exagerated reflexes, high mortality rate if untreated

• lab diag: no good serologic test. organisms are seldum isolated from the wound site
• tetanus is prevented by immunization with tetanus toxoid in childhood and every 10 years thereafter
• when trauma occurs - wound should be cleaned and tetanus booster toxin given; wound is grossly contaminated, tetanus immune globulin, as well as the toxoid booster, should be given

• botulism
• gram+ rod with subterminal spore
• several neurotoxins. all toxins are destroyed at 100C; resistent to enzymes and HCl in GI tract
• toxins inhibit release of Ach at MEP- = muscle paralysis
• production of toxin is determined by lysogenic phage and chromosomal genes
• acidic canned foods
• 18-96 hours incubation time; paralysis, dry mouth, constipation, urine retention
• Treatment: antitoxin and antibiotics to patients with wound botulism

• transmission - organism is carried in the GI tract of 3% of gp
• 30% of hospitalized patients becoem colonized and this organism is, therefore, and important cause of nosocomial disease
• transmitted by the fecal - oral route
• pathogenesis: antibiotics supress drug - sensitive members of normal flora allowing clostridum difficile to multiply and produce exotoxins a and b
• exotoxin a: enterotoxin that causes an outpouring of intestinal fluid resulting in watery diarrhea
• exotoxin b: cytotoxin that causes damage to colonic mucosa, leading to pseudomembrane formation

• causes diarrhea, associated with pseudomembranes (yellow-white plaques) on colonic mucosa
• diarrhea is not usually bloody
• neutrophils are found in stool in about half the cases
• pseudomembranes are visualized by sigmoidoscopy
• toxic megacolon can occur and surgical resection of the colon may be necessary
• no vaccine

• anaerobic
• gram- pleomorphic rods, non-spore forming
• flora of mouth and colon
• mcc of serious anaerobic infections

• most frequent anaerobe pathogen
• infections often endogenous, usually arising from a break in a mucosal surface; non communicable
• can cause a variety of infections such as local abscesses at the site of mucosal break and metastatic abscesses by spread of distant organs

• E.coli
• utilize the oxygen and contribute to the growth of this anaerobe

intra-abdominal infections - either peritonitis or localized abscesses; pelvic abscesses and bacteremia also occur

• oral, pharyngeal, and pulmonary abscesses are more commonly caused
• member of the normal oral flora
• causes disease above the diaphragm

cause disease below the diaphragm

• can be isolated anaerobically on BAP containing kanamycin and vancomycin to inhibit unwanted mo
• identified by biochemical reacitons and by the production of certain organic acids which are identified by gas chromatography
• no vaccine
• diagnosis can be confirmed on th ebasis of sugar fermentation tests: meningococci ferment maltose, whereas gonococci do not (both germent glucose)
• bacteroides melaninogenicus - produces characteristic black colonies

• gram- diplococci
• resemble paired kidney beans
• non-motile
• usually capsules & fimbriae
• grows best with CO2 and blood (fastidius)
• Oxidase+
• phagocytosed by neutrophils

• Meningitis and Meningococcemia
• bap enhanced with CO2
• capsule antigens divide into serotypes. vaccines for most of these serotypes
• respiratory droplets: humans are the only natural hosts
• nasal carriers (5-15%)
• attaches to non-ciliated columnar ET of host upper respiratory tract by fimbriae
• IgA protease (destroys IgA (gamma globulin fraction))
• enters meninges by blood stream
• diagnosis: spinal tap L4-L5
• Treatment: massive doses of antibiotics get into cns

• characterized by high fever, shock, wide-spread purpura (a small hemorrhage in the skin, mucous membrane, or serosal surface)
• disseminated intravascular coagulation and adrenal insufficiency

• chemoprophylaxis and immunization are both used to prevent meningococcal disease
• rifampin is used for prophylaxis because it is secreted in saliva
• meningococcal vaccine, contains capsular polysaccharides of groups A,C,Y, and W-135 strains is effective in preventing epidemics and reducing the carrier rate
• vaccien does not contain gropu B polysaccharide, which is poorly antigenic in humans

• used to identify species of Neisseria
• procedure that can assist in the rapid diagnosis of meningococcal meningitis is the latex agglutination test -> detects capsular polysaccharide in the spinal fluid

• Gonorrhea
• chocolate agar (heated blood) with CO2
• very high in teenagers (asymptomatic females about 50% due to urethra size)
• not normal flora -> sometimes in throat or rectum
• diagnosis: symptoms (males): 2-7 days purulent urethral discharge with dysuria
• gram- diplococci inside neutrophils
• test for enzymes, e.g. sugar fermentation. no good serological test

• agar containing a variety of antibiotics
• chocolate agar
• incubated at 37C
• finding of oxidase - positive colonies composed of gram negative diplococci is sufficient to diagnose Neisseria
• can use ELISA (detects antigens) or DNA probe assay (detects gonococcal ribosomal genes)
• no vaccine. usual serological tests are not useful

• normal flora of the oral cavity and upper respiratory tract
• do not grow on thayer-martin agar

escherichia coli, shigella, salmonella, yersinia, serratia, citrobacter, klebsiella, enterobacter, proteus, providencia, morganella

• all gram- rods
• most in large intestines
• aerobic to anerobic
• no spores
• some cause diarrhea

• mcc of urinary tract infections
• when get into blood, may cause sepsis
• may have fimbraie
• some have capsules
• most secrete slime
• Habitat: L1, female genital tract, some may be in upper respiratory tract, some can be free-living
• all possess LPS toxin and usually many other toxins
• divided into strains (instead of species) based on antigens present in CW, capsule, and flagella

• o antigens - cw lipopollysaccharide (LPS)
• a antigens - CW lipid
• k antigens - capsules
• h antigens - flagella
• O111:H7 - very virulent (uremic toxemia - renal failure)
• -->urinary tract infections, intestinal tract infection (diarrhea), meningitis (neonatal)
• O18:K76
• 150+ types based on antigens
• ferments lactose -->EMB agar

• cultural characteristics (colony size, shape, color, etc.)
• biochemistry: all ferment glucose, reduce nitrates, oxidase negative
• they differ in: carbohydrate fermentations, SIM test
• antigens (O,A,K,H)

• do not ferment lactose
• no H2S gas
• non-motile, speciate with antigens and biochemistry

• usa under 10 years
• fecal contaminatio: dysentery (shiegella flexneri, boydii, and dysenteriae), bloody diarrhea, acute inflammatory colitis
• plasmids were first discovered in this

• do not ferment lactose
• release H2S gas
• Enterocolitis & Septicemia
• ubiquitous in animals. usually acquired by fecal contamination of man and animals (chicken) - gastroenteritis

• typhoid fever
• gastroenteritis and enteric fever
• tests: stool culture on EMB agar or deoxycholate

• gram- bipolar staining
• mainly an animal parasite

• causes the plague
• enters dermal lymphatics by flea bites
• zoonosis

• invades mesenteric lymphatics (peyer's patches)
• do not possess the virulence factors of Yersinia pestis
• transmitted to humans by contamination of food with the excreta of domestic animals (dogs, cats, cattle)
• can cause mesenteric adentis that clinically resembles acute appendicitis; rarely they are involved in bacteremia or abscesses of the liver and spleen
• enterocolitica - clinically indistinguishalbe from that caused by salmonella or shigella

• slowly ferment lactose
• inducible enzymes
• opportunist - diarrhea
• nosocomial infections
• resistant

• biochemically and serologically similar to salmonella, but usually does NOT cause enterocolitis or enteric fever
• maybe present in normal intestinal flora
• opportunist and may cause diarrhea
• can use citrate as sole source of carbon

• severe pnemonia & URT infections
• polysaccharide capsule and non-motile
• over 70 types based on capsule possess fimbriae

• lobar pnemonia and is now resistant to many antibiotics
• grows in lungs (not GI)

• mild pnemonia
• ferment lactose
• peritrichous flagella
• less virulent than Klebsiella pnemoniae (mild pnemonia)
• usually found in mixed infections
• now resistant to many antibiotics

• proteus (p. vulgaris)
• providencia
• morganella

• gram-
• often polar flagella
• chains of coma shaped rods - streptobacilli
• marine habitat - tolerate SALT (halophilic)
• most infections are due to penetrating wounds (fish hook)

• cholera
• speciated by: o antigens, biochemistry, enterotoxins
• usually acquired by fecal contamination
• rice water stool (rice substance is GI epithelial cells)
• vaccines. carriers.
• no abdominal pain and subsequent symptoms are referable to the marked dehydration -> loss of fluid and electrolytes may lead to cardiac and renal failure
• acidosis and hypokalemia

• marine organism transmitted by contaminated seafood
• major cause of diarrhea in japan
• varies from mild to severe watery diarrhea, nausea and vomiting, abdominal cramps and fever
• lasts about 3 days
• can be prevented by proper refrigeration and cooking of seafood

• found in seawater
• caues severe skin and soft tissue infections (cellulitis), especially in shellfish handlers thru skin wounds
• also cause a rapid fatal septicemia of AIDS patients who have eaten raw shellfish containing the organism
• chronic liver diseases (cirrhosis) predisposes to severe infection

• halophilic
• often enter thru cuts in marine environment
• diarrhea and cramps

• curved gram- rods
• polar flagella
• oxidase(+) & microaerophilic. Urease negative
• normal flora of GI and UG tract flora of animals (cows, sheep, birds, dogs)
• frequent cause of enterocolitis, especially in children, and a rare cause of systemic infection, particularly bacteremia
• transmission: by fecal - oral route

• diarrhea
• C. jejuni - begins as watery foul-smelling diarrhea followed by bloody stools accompanied by fever and severe abdominal pains

• abotion in animals - due to toxin coating fetus causing the immune system to turn on it, abortion ensures
• sepsis in humans

• systemic infections, most commonly bacteremia
• lab diagnosis: patient has diarrhea, a stool specimen is cultured on a blood agar plate containing antibiotics to inhibit other fecal flora
• no vaccine. proper sewage disposal and personal hygiene (hand washing) are important in preventing the disease

• curved gram- rods
• peptic ulcers and gastritis
• urease +
• helicobacter pylori

• attaches to mucus secreting cells of gastric mucosa
• production of large amounts of amonia from urea by organism's urease, coupled with an inflammatory response, leads to damage of the mucosa
• loss of protective mucus coating predisposes to gastritis and peptic ulcer -> ammonia neutralizes stomach acid, allowing mo to survive
• natural habitat of H. pylori is human stomach, acquired by ingestion; person to person transmission probably occurs

• lab diagnosis: gram stained smears of biopsy specimens of gastric mucosa
• cultured on special media. presence of IgG antibodies can be used as evidence of infection
• "urease breath" test, in which radioactive urea is ingested, can also be used
• if mo is present, radioactive carbon dioxide is evolved and detected in the breath
• treatment and prevention: treatment of duodenal ulcers with antibodies and bismuth salts (pepto-bismol) results in greatly decreased occurence rate
• no vaccine

• gram- rods - resemble enterobacteriacae, but differ in that they are strict aerobes
• do not ferment glucose
• oxidase positive (oxidation involves electron transport by cytochorme C)
• able to grow in water containing only trace nutrients e.g. tap water
• favors their persistence in the hospital environment
• some withstand disinfectants

• gram- rod
• aerobic, motile, opportunist (wound, tube, etc)
• water soluble greenish pigment
• pathogen of plant and animals
• most commonly found in humans: burns, cystic fibrosis, aids, and catheterizations
• treatment: swab lesion -> culture -> test for enzymes

• found in soil and water
• colon flora - found on skin in moist areas and can colonize the URT of hospital patients
• ability to grow in simple aqueous solutions has resulted in contamination of respiratory therapy and anesthesia equipment, intravenous fluids, and even tap water
• opportunist, exotoxin and endotoxin play roles in pathogenesis
• two pigments: pyocyanin and fluroescein are non toxic

• cause infectious virtually anywhere in the body but urinary tract infections, wound infections and burns predominate
• can enter blood and cause sepsis
• can spread to skin where causes black, necrotic lesions
• corneal infections are seen in contact lens users

• gram- coccobacilli
• non-motile
• some have capsules
• most have fimbriae

• needs complex lab media containing hematin (factor X) and NAD (factor V)
• vaccines
• spreads by droplet infection (epidemic WWI)
• respiratory transmission, meningitis is most common type of infection with brian damage and middle ear infections.
• epiglottiditis, cellulitis, arthritis, and varied respiratory tract infections

• infects only humans and no animal reservoirs
• enters body through URT, resulting in asymptomatic colonization or infections such as otitis media, sinusitis, or pnemonia
• organism produces IgA protease that degrades IgA, thus facilitaing attachment to respiratory mucosa
• URT may spread via blood to meninges -> meningitis is primarily caused by the encapsulated strains
• most infections occur in children between the ages of 6 mts to 1 yr

• chocolate agar enriched with factor X (heme) and factor V (NAD)
• biochemical tests
• Quellung test, flurescent antibody tests, agglutination tests

• cannot be distinguished on clinical grounds from that caused by other bacterial pathogens (pnemonococci or meningococci)
• rapid onset of fever, headache, stiff neck, and drowsiness
• sinusitis and otitis media cause pain in the infected area
• rarely, epiglottis can obstruct the airway

• whooping cough or pertussis
• strict human pvaccine athogen
• incubation 7-10 days
• catarrhal stage (inflammation of mucous membranes), paroxysmal cough (spasm), convalescence
• Nasal swab on charcoal (cocolate) blood agar fluorescent antibody serology
• DPT

• PPLO - pleura pnemonia0like organism
• no cell wall
• gram-, but stain poorly
• .2 micrometers (smallest cell)
• pleomorphic
• sterols in cm acquired from media (the mo does not make sterols)
• aerobic to facultative anaerobic (species dependent)

• fried egg colonies
• 20% of pnemonia
• droplet infection
• very low infectious dose
• attaches to bronchial ET via cytadhesion protein in its cytoplasmic membrane
• grow on mycoplasma agar

flluorescent antibody test more sensitive

• flora of genitourinary tract
• post - abortion and post - partum infections
• disease is usually self limiting
• other mycoplasmae often found in arthritis

• gram-, but stain poorly
• no cell wall
• .2 micrometers
• pleomorphic
• sterols in CM
• urease + (mycoplasma are urease -) salts ppt in urine
• Only 1 species: Ureaplasma urealyticum

• female genital tract
• sexually transmitted
• no sterility
• itching
• non - gonococcal, non -chlamydial urethritis

• 30+ species
• Thin (.2 micrometer), pleomorphic
• gram- rod
• 2-20 micrometer long
• stains poorly with Gram reagents
• use silver impregnation stains (coats the rods, blackish)
• most have flagella
• no spores
• aerobic

• Legionellosis or Legionnaries disease
• fastidius (requires L-cysteine and Fe+3)
• colonies resemble "ground glass"
• found in fresh water, soil; parasite of protozoa (amoeba)
• cases - linked to water habitat: hotel cooling towers for air conditioners, respiratory devices, tap water
• person to person spread not shown
• attacks the lungs: necrotizing multifocal pnemonia
• 2 syndromes: legionnaires' disease (severe pnemonia) and Pontiac fever (non-pnemonia, febrile, not life threatening)
• fluroescent antibody tests

• clinical picture can vary from a mild influenza - like illness to a severe pnemonia accompanied by mental confusion acompanied by mental confusion, non-bloody diarrhea, proteinuria, and hematuria
• sputum is frequently scanty and non-purulent - cough is prominent
• spontaneously in 7-10 days, but in older or immunocompromised patients the infection may be fetal

Gram- cocobacillary rod

• major pathogen
• member of normal flora of upper respiratory tract
• causes sinusitis, otitis, bronchitis, and pneumonia - especially in immunocompromised patients

two common causes of blephartitis (infection of eyelid)

• flexible, peptidoglycan CW with axial fibril (proteins)
• motile; slim (.15 micrometers)
• Dark field m.s. or e.m.
• Gram negative -> too thin to visualize with conventional compound light microscope
• normal flora of mouth

• syphilis
• grows in lab by special tissue culture or on skin, cornea, or testes of rabbit
• acquired: sexual contact, lesions, drug user needles

• permanent scar tissue on skin
• Hutchinson's teeth (affects tooth bud)
• multiple effects on eyes, organs
• exclusive human pathogen

• 3 stages:
• Primary: 2-10 weeks; Hard chancre (haemophilus ducreyi -soft chancre "chancroids); heals in 3-8 weeks; Silent 2-10 weeks
• Secondary: