Microbiology Exam 4 Chapter 16

bacteri-yuh

Bacillus, Clostridium

Medically important gram-positive bacilli

Endospore formers

Listeria, Erysipelothrix

Medically important gram-positive bacilli

Non-endospore formers

Corynebacterium, Proprionibacterium, Mycobacterium, Actinomyces, Nocardia

Medically important gram-positive bacilli

Irregular shaped and staining properties

gram-positive

Is the Genus Bacillus gram-positive or gram-negative?

soil

the primary habitat of the Genus Bacillus

antibiotics

Genus Bacillus is a source of _______

saprobic

the Genus Bacillus is _____, meaning it finds nourishment from decaying material

Bacillus anthracis, Bacillus cereus

2 medically important species of the Genus Bacillus

polypeptide capsule and exotoxins

Virulence factors of Bacillus anthracis

cutaneous anthrax

anthrax: spores enter through skin, leads to black sores, least dangerous

eschar

black sore

pulmonary anthrax

anthrax: inhalation of spores

gastrointestinal anthrax

anthrax: ingested spores

antibiotics

What is Bacillus anthracis treated with?

purified toxoid vaccine

type of Bacillus anthracis vaccine given for high risk occupations and military personnel

Bacillus cerus

ingestion of toxin-containing food from this pathogen causes nausea, vomiting, abdominal cramps and diarrhea; 24 hour duration

Genus Clostridium

genus that gives rise to botulism, gas gangrene, tetanus, and really bad diarrhea

large diverse group of clinically significant anaerobes

Gram positive

Genus clostridium are gram ____ rods or bacilli

anaerobic

Genus Clostridium is (an)aerobic??

normal flora

Despite how pathogenic many of the species of Clostridium are, it is actually part of your ___ ___

lower GI tract

Genus Clostridium mainly resides in your _________

C. botulinum, C. difficile, C. perfringens, C. tetani

Four major species of genus Clostridium

spore

all Clostridium species are _____ formers

tennis rackets

Most of the time, Clostridium looks like rods, but when they form spores they look like ____ _____

Clostridium perfringens

cause of gas gangrene

3rd most common cause of food poisoning

causes very different diseases depending on where it invades

1 million to 10 million

need to ingest this much C. perfringens per gram of food to actually get sickz

contaminated meat

C. perfringes food poisoning is usually from ____

infection

C. perfringes is ________ not intoxication

8-18, 24

C. perfringes food poisoning usually has onset of nausea, cramping, and diarrhea occuring _____ hours after eating and lasts for ____ hours

Anaerobic cellulitis, gas gangrene

If C. perfringes is causing the disease by infecting a wound, there are two pathways it takes depending on where bacteria enters the body:

anaerobic cellulitis

bacteria gets in fascial spaces, but not into muscle

destroys unhealthy tissue

atherosclerosis, diabetes

anaerobic cellulitis:

diseases that predispose to anaerobic tissue conditions

decrease blood circulation to tissue

gas gangrene

bacteria is a fermenter → gas

foul smelling gas can cause crackling on palpation

kills healthy tissue

can lead to systemic toxicity

moves fast, limb amputation often required

hyperbaric oxygen is another treatment

myonecrosis

another word for gas gangrene

crepitus

a crackling or grating sound usually of bones

Clostridium difficile

one cause of antibiotic associated diarrhea and pseudomembranous colitis

small number of healthy people carry it, but in the hospital, large % carries it

opportunistic

very contagious, easy to spread

feces

C. diff is passed in ______ then spread by unwashed hands

pseudomembranous colitis

C. diff can cause ____________ which is life threatening

Tx for C. diff

get off antibiotics and take other antibiotics

can also add probiotics

stool transplant for recurring infections

Clostridium botulinum

causes botulism

neurotoxin

botulism is caused by the action of a _____ that is one of the most potent poisons known

not required

Something special about C. botulinum is that contact with organism itself is __________ and can solely be due to ingestion of toxin-contaminated food

anaerobic

_____ conditions favor spore germination and vegetative growth

botulin

actual neurotoxin that blocks NMJ and causes blurred vision and flaccid paralysis

blocks release of Ach

boiling

prevention: botulin is inactivated at ________ temps

antitoxin

treatment for C. botulinum

wound botulism

rare form of botulism with pathogenesis similar to tetanus

Clostridium tetani

common resident of soil and GI tracts of animals

causes tetanus and lockjaw (neuromuscular disease)

geriatric, IV

C. tetani most commonly among _________ patients and _______ drug abusers

accidental

C. tetani spores usually enter through ______ puncture wounds, burns, umbilical stumps, frostbite, and crushed body parts

anaerobic

type of environment that is ideal for vegetative C. tetani cells to grow and releass toxin

tetanospasmin

this neurotoxin of C. tetani causes paralysis by binding to motor nerve endings; blocking the release of neurotransmitter for muscular contraction inhibition; muscles contract uncontrollably

respiratory

death of C. tetani most often due to paralysis of _______ muscles

10

Vaccine available for C. tetani, needed every __ years

penicillin, tetracycline, muscle relaxants

control C. tetani infection with these three things

human tetanus immune globulin

antitoxin therapy for C. tetani using ____; inactivates circulating toxin but does not counteract that which is already bound

lipopolysaccharide

all aerobic gram negative non enteric bacilli have a _______ outer membrane of cell wall

endotoxin

A toxic component of the outer membrane of certain gram-negative bacteria that is released only when the bacteria die.

Pseudomonas, Burkholderia

examples of opportunistic pathogens of aerobic gram-negative non-enteric bacilli

Brucella, Francisella

examples of zoonotic pathogens of aerobic gram-negative non-enteric bacilli

Bordetella, Legionella

mainly human pathogens of aerobic gram-negative non-enteric bacilli

Pseudomonas Aeruginosa

common inhabitant of soil and water

intestinal resident in 10% normal people

Resistant to soaps, dyes, quaternary ammonium disenfectants, drugs, drying

frequent contaminant of ventilators, IV solutions, anesthesia equipment

whooping cough

Bordetella Pertussis causes pertussis, also known as ______ _____

-acute respiratory syndrome

-often severe, life-threatening complications in babies

apparently healthy carriers

Bordetella Pertussis reservoir

direct contact or inhalation of aerosols

Transmission of Bordetella Pertussis

toxins

virulence factors of Bordetella Pertussis

DTaP

Vaccine for B. Pertussis

Acellular vaccine contains toxoid and other Ags

ciliary

In pertussis; Loss of ______ mechanism leads to buildup of mucus and blockage of airways

Enterobacteriaceae Family

family of bacteria that cause intestinal trouble (ex: Escherichia, Salmonella, Campylobacter, Shigella, Vibrio)

resistant

Enterobacteriaceae family are _______ to antibiotics

50

Enterics, along with Pseudomonas sp., account for almost __% of nosocomial infection

nosocomial

term meaning originating from a hospital

glucose

all genera of the Enterobacteriaceae family ferment ______, which produces a lot of gas

→ divided into coliforms vs. non-coliforms

coliforms

lactose fermenters

non coliforms

non lactose fermenters

KOH

3 major groups of antigens

O157:H7

one of the deadliest E. coli strains

Escherichia Coli

most prevalent enteric bacillus

150 strains

Enterotoxigenic

Pathogenic strain of E. coli causes severe diarrhea due to heat-labile toxin and heat-stable toxin

Enterohemmorhagic

Pathogenic strain of E. coli, O157:H7 strain, causes hemorrhagic syndrome and kidney damage

Enteroinvasive, Enteropathogenic

Two other types of pathogenic strains of E. coli

Not enterotoxigenic or enterohemmorhagic

infantile diarrhea

E. coli pathogenic strains are frequent agents of ________ - greatest cause of mortality among babies

70

E. coli causes ~__% of traveler’s diarrhea

50-80

E. coli causes __ - _% of UTIs

coliform count

indicator of fecal contamination in water

opportunistic coliforms

K. pneumoniae, Enterobacter sp., Citrobacter sp., S. marcescens are all _______

noncoliform enterics

Proteus, Morganella, Providencia, Salmonella, Shigella, and Haemophilus are all examples of what

Salmonella and Shigella

• well developed virulence factors, primary pathogens

• Not normal human flora

• Some GI involvement and diarrhea but often affect other systems

Salmonella typhi

most serious pathogen of the genus; cause of typhoid fever; human host

Salmonella cholerae-suis

zoonosis of swine

Salmonella enteritidis

Its different serotypes cause animal Salmonelloses

• cattle, poultry, rodents, reptiles, animal, and dairy products

fecally contaminated

In Typhoid Fever, bacillus enters with ingestion of ___________ food or water

asymptomatic

typhoid fever carriers are __________

galbladder

some typhoid fever chronic carriers shed bacilli from _______

less severe, prevalent

animal salmonelloses are usually _______ than typhoid fever but more ________

Shigellosis

incapacitating dysentery

Haemophilus influenzae

causes acute bacterial meningitis, epiglottitis, otitis media, sinusitis, pneumonia, and bronchitis

Hib

subunit vaccine for H. influenzae

Haemophilus aegyptius

Causes conjunctivitis (pink eye)