GRAM POSITIVE

Question 1

The most severe form of this disease results from the inhalation of spores with mediastinitis, pulmonary edema, and hemorrhage (Woolsorter’s disease)

Answer 1

Bacillus anthracis

-can occur as an OCCUPATIONAL DISEASE of TEXTILE or AGRICULTURAL PERSONNEL resulting from contact with INFECTED HIDES or WOOL; recently, it has gained attention as an agent of BIOWARFARE and BIOTERRORISM

Question 2

Causes gastroenteritis and is typically associated with consumption of reheated rice

Answer 2

Bacillus cereus

-rapid EMESIS or DIARRHEA is associated with an ENTEROTOXIN that INCREASES cAMP and is produced by the organism as it germinates

Question 3

Disease can be due to the ingestion of preformed toxin in home-canned foods or by ingestion of spores in honey by an infant

Answer 3

Clostridium botulinum

-symptoms include FLACCID PARALYSIS, dry mouth, diplopia, dysphagia, and RESPIRATORY FAILURE

Question 4

Associated with the use of broad-spectrum abx and the overgrowth of toxin-producing bacteria

Answer 4

Clostridium difficile

-results in PSEUDOMEMBRANOUS COLITIS and is also a major nosocomial disease

Question 5

Causes gas gangrene and is often associated with automobile and motorcycle accidents

Answer 5

Clostridium perfringens

-SPORES are abundant in soil and GERMINATE IN WOUNDS; treatment includes surgical debridement, abx, and HYPERBARIC OXYGEN

Question 6

Infection is associated with traumatic inoculation of spores that germinate and produce a toxin that causes a spastic paralysis

Answer 6

Clostridium tetani

-the organism looks like a long rod with a DILATED TERMINAL END containing a SPORE that resembles a TENNIS RACQUET

Question 7

Can causes risus sardonicus, the characteristic grimace of lockjaw

Answer 7

Clostridium tetani

-treatment includes the use of ANTITOXINS produced in HORSES or hyperimmunized humans, and ANTISPASMODICS such as benzodiazepines

Question 8

Causes a fishy smelling vaginal discharge

Answer 8

Gardnerella vaginalis

-histologically characterized by the presence of “CLUE CELLS”, vaginal epithelial cells covered with bacteria, seen on a pap smear

Question 9

As the dominant organism of normal vaginal flora, its metabolism helps maintain the low pH of the vagina

Answer 9

Lactobacillus spp.

-the LACTIC ACID produced helps prevent the OVERGROWTH OF POTENTIALLY PATHOGENIC ORGANISMS; with the use of BROAD-SPECTRUM ABX, such acid-producing FLORA IS LOST, allowing for OVERGROWTH of pathogenic species

Question 10

A major cause of acute bacterial endocarditis, especially in IV drug users

Answer 10

Staphylococcus aureus

-unlike subacute bacterial endocarditis, this organism can cause infection of UNDAMAGED HEART VALVES, typically on the RIGHT SIDE [tricuspid] in IV DRUG USERS

Question 11

The 2nd leading cause of UTI in sexually active women

Answer 11

Staphylococcus saprophyticus

-differentiated from Staphylococcus epidermidis by its ability to FERMENT MANNITOL and its resistance to novobiocin

Question 12

Infection results in rheumatic fever

Answer 12

Streptococcus pyogenes (Group A)

-characterized by a constellation of symptoms including MIGRATORY POLYARTHRITIS, ERYTHEMA MARGINATUM, PANCARDITIS, Syndenham CHOREA, and SUBCUTANEOUS NODULES

Question 13

A major cause of pharyngitis, infection can also result in other suppurative symptoms such as erysipelas, cellulitis, and impetigo

Answer 13

Streptococcus pyogenes (Group A)

-infection with this BETA-HEMOLYTIC, BACITRACIN-SENSITIVE cocci can be serodiagnosed with the detection of host antibodies to bacterial DNase B and ANTI-STREPTOLYSIN O [ASO]

Question 14

Infection can lead to the development of acute glomerulonephritis and mitral and aortic stenosis

Answer 14

Streptococcus pyogenes (Group A)

-IMMUNOCOMPLEX DEPOSITION in the kidney visualized by “LUMPY-BUMPY” immunofluorescence; CROSS-REACTIVE ANTIBODIES to the bacteria result in AUTOIMMUNE DESTRUCTION of the heart valves

Question 15

Causes gray pseudomembranes on the back of the throat

Answer 15

Corynebacterium diphtheriae

-organisms often viewed in a “CHINESE-LETTER” configuration

Question 16

A major cause of dental carries

Answer 16

Streptococcus mutans

-a member of the VIRIDANS GROUP, it is also ALPHA-HEMOLYTIC and OPTOCHIN-RESISTANT

Question 17

Leading cause of subacute bacterial endocarditis

Answer 17

Streptococcus viridans

-this ALPHA-HEMOLYTIC, OPTOCHIN-RESISTANT COCCI is part of the NORMAL FLORA of the HUMAN PHARYNX

Question 18

Part of the normal flora of the skin, it causes infection of IV lines and catheters; it is a major cause of endocarditis in patients with prosthetic heart valves

Answer 18

Staphylococcus epidermidis

-similar to Staphylococcus aureus, but grows as white colonies, DOES NOT PRODUCE COAGULASE, DOES NOT FERMENT MANNITOL, and does not produce Protein A

Question 19

An important cause of neonatal sepsis and meningitis

Answer 19

Streptococcus agalactiae (Group B)

-this BETA-HEMOLYTIC, BACITRACIN-RESISTANT cocci is a NORMAL inhabitant of the FEMALE GENITAL TRACT and can be acquired during VAGINAL DELIVERY

Question 20

Lancet-shaped dipolococci found in a rusty brown sputum

Answer 20

Streptococcus pneumoniae

-causes >90% of all cases of LOBAR PNEUMONIA

Question 21

A common cause of nosocomial infections, this organism is often resistant to many Abx, including vancomycin

Answer 21

Enterococcus spp.

-common cause of UTI’s, sepsis, meningitis, and endocarditis

Question 22

Part of the microbial flora of the skin, this bacilli contributes to the development of acne

Answer 22

Propionibacterium acnes

-the organism produces LIPASES that split fatty acids that cause INFLAMMATION, resulting in the formation of COMEDONES

Question 23

A major cause of abscesses, furuncles, carbuncles, and other skin infections such as impetigo

Answer 23

Staphylococcus aureus

-this BETA-HEMOLYTIC cocci grows in GRAPE-LIKE CLUSTERS, produces COAGULASE, and grows in culture as YELLOWISH colonies

Question 24

This cause of late onset neonatal sepsis is a facultative intracellular parasite that spreads from cell to cell via actin rockets

Answer 24

Listeria monocytogenes

-this organism can be detected as short non-spore-forming rods with a tumbling END-OVER-END motility

Question 25

The organism is detected as PAS+ rods within the macrophages of the lamina propria of the small intestine

Answer 25

Tropheryma whippelii

-the causative agent of WHIPPLE’S DISEASE that results in abdominal pain, MALABSORPTION with diarrhea and weight loss, and a migratory polyarthritis

Question 26

Chronic exposure to this group of organisms leads to the development of hypersensitivity pneumonitis, including Farmer’s lung, Pigeon breeder’s lung, and Humidifier lung

Answer 26

Thermophilic actinomycetes

-exposure causes an IMMUNOLOGICALLY MEDIATED INTERSTITIAL FIBROSIS, bronchilotis, and GRANULOMA formation with progressive respiratory failure and CYANOSIS

Question 27

The use of a quellung reaction helps differentiate between the 85 different capsular subtypes

Answer 27

Streptococcus pneumoniae

-this ALPHA-HEMOLYTIC, OPTOCHIN-SENSITIVE bile-soluble coccus grows on sheep RBC agar; the VACCINE contains at least 23 OF THESE SUBTYPES

Question 28

As well as being Gram +, this organism is also weakly acid fast and causes a pneumonia predominantly in immunocompromised patients

Answer 28

Nocardia asteroides

-this aerobic bacteria with FILAMENTOUS GROWTH is a common soil organism

Question 29

A normal inhabitant of the oral cavity, infx can be associated with dental procedures, with formation of lesions that erupt through the face with a purulent discharge

Answer 29

Actinomycetes israelli

-diagnosis is by finding SULFUR GRANULES= tangles of filaments of organisms wrapped in a matrix of calcium phosphate, imparting a YELLOW [sulfur] color to the ABSCESS and discharge