Gram Positiv Bacilli Flashcards by Iseoluwa Ojo

6 medically important genera of GPB:

List them

 Bacillus
 Clostridium
 Corynebacterium
 Listeria
 Gardnerella
Erysipelothris

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Out of the 5 medically important genera of GPB, which have spores and which do not

Bacillus and Clostridium – spores
Corynebacterium, Listeria, and Gardnerella –no spores

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Based on their tolerance for oxygen

 Bacillus – ______
 Clostridium - ______
 Corynebacterium -_____
 Listeria – _______
 Gardnerella – ______

aerobic

anaerobic

aerobic

falcultative anaerobe

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Gram staining appearance

These GPB can also be distinguished based on their appearance

 ________ and ________ are longer and more deeply staining than _________ and ________

Bacillus and Clostridium spp

Corynebacterium and Listeria spp

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Corynebacterium species are _____-shaped

Corynebacterium and Listeria species
characteristically appear as ____ or ___ shaped rods

club

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 Gardnerella vaginalis is a (short or long?) and gram ______

Short

variable

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General Characteristics of Bacillus

~___ species

Gram- _____or Gram- _____ bacilli

(Small or Large?) (0.5 x 1.2 to 2.5 x 10 um)

positive; variable

Large

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General Characteristics of Bacillus

Most are __________ or _________

Bacillus _________ is most important member

saprophytic contaminants or normal flora

anthracis

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General Characteristics of Bacillus

Presence or absence of endospores?

Catalase (positive or negative?) (most)

Presence

Positive

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General Characteristics of Bacillus

Bacillus spp. are ubiquitous

T/F

Soil, water, and airborne dust

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General Characteristics of Bacillus

Thermophilic (< 75°C) and psychrophilic (>5-8°C)
Can flourish at _________ PH (pH _____)

extremes of acidity & alkalinity

2 to 10

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Bacillus Endospores

(Thin or Thick?) walled structures formed by _______ cells

Thick ; vegetative

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Bacillus endospores

Are Resistant to radiation, chemicals, heat, desiccation (dipicolinic acid)

T/F

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__________ is necessary for destruction of bacillus endospores

Steam autoclaving

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List 5 species of bacillus

Anthracis
Cereus
Mycoides
Thuringiensis
Others🌚

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Laboratory Characteristics of Bacillus
On blood agar

(Small or Large?) , spreading

_______ colored colonies with ( regular or irregular?) margins

Large

gray-white

Irregular

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Laboratory Characteristics of Bacillus
On blood agar

Many are (alpha or beta?) -hemolytic which is helpful in _____________

Beta

differentiating various Bacillus species from B. anthracis

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Laboratory Characteristics of Bacillus
On blood agar

Spores seen after ____ days of incubation, but not typically in _________ specimens

several

fresh clinical

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Virulence of B. Anthracis

Virulent strains produce ______ exotoxins that combine to form _____ toxin and ____ toxin

three

edema

lethal

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edema toxin = _____ + _____

lethal toxin = ____ + ______

protective antigen; edema factor

protective antigen; lethal factor

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Epidemiology of B.anthracis

Primarily infects _____ with _____ as accidental host

Rarely isolated in ______ countries but is prevalent in ______ areas where __________

herbivores

humans

Developed

Impoverished
vaccination of animals is not practiced

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Epidemiology of B.anthracis

People at risk are those in endemic areas in _________________, and people who _____________

contact with infected animals or contaminated soil

work with animals imported from endemic areas

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There is little concern that the spores of bacillus Anthracis would be used for bioterrorism

T/F

Significant concern

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Diseases of Bacillus Anthracis

___________ is the most common form

___________ is the most deadly form

________ is a rare form but commonly fatal

Cutaneous anthrax

Inhalational anthrax

Gastrointestinal anthrax

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Treatment of bacillus Anthracis _______ is the drug of choice It’s resistant to ______

Ciprofloxacin Sulfonamides and extended spectrum cephalosporins

Prevention of bacillus Anthracis _________ can control disease but the spores are difficult to eliminate from _____

Vaccination of animal herds Soils

In Prevention of bacillus Anthracis ______ vaccination is effective _______ vaccination has limited usefulness

Animal Human

Bacillus cereus Group Gastroenteritis Can grow in food and cause food poisoning by either producing: Heat-stable enterotoxin (_____form) Heat-labile enterotoxin (______ form)

emetic diarrheal

Bacillus cereus Group Gastroenteritis Heat-labile enterotoxin (diarrheal form) Similar to ______ – stimulates cAMP which leads to _______

V. cholera watery diarrhea

Bacillus cereus Group Other Clinical conditions _______ infections after trauma _______-related sepsis, _____,_____

Ocular IV-catheter endocarditis, meningitis

Bacillus cereus Group Other Clinical conditions Ocular infections after trauma –______ toxin, _______, phospholipase C IV-catheter-related sepsis, endocarditis, meningitis –_________ persons and _____

Necrotic ; hemolysin Immunocompromised drug abusers

L. monocytogenes Widespread in nature. Causes _________.

listeriosis

L. monocytogenes Very (Common or Rare?) ______ cases, ____ deaths _____% fatality.

Rare 2,500; 500 2- 30

Listeria monocytogenes •Gram- _____bacilli/______ •Catalase- ________ •Motile or Non-motile ?

positive ; coccobacilli positive Motile

Listeria monocytogenes •Esculin positive or negative? •___ hemolytic •Multiplies at __ o C

Positive beta 4

LISTERIOSIS (Symptomatic or Asymptomatic?) (mild or sever?) GI, unless disseminated infection (________) which leads to ______

Asymptomatic mild Bacteremia; Meningitis

LISTEROSIS Requires _________ to clear. ______CELLULAR PATHOGEN.

cellular immune response INTRA

At-risk populations for invasive listeriosis _______ women/ _____ Patients at _______ Patients with _____

Pregnant; fetuses extremes of age AIDS

At-risk populations for invasive listeriosis Patients taking _________ medications Patients with immunosuppressing co-morbidities (cancer, autoimmune disease, alcoholism, diabetes mellitus)

immunosuppressive

Listeria: Pathogenesis Organism adapted to grow at (low or high?) temperatures Multiplies in _______ of ———- and ———

Low cytoplasm of macrophages and epithelial cells

Listeria toxin _______ O which is a _______ Asymptomatic carriage reservoir

Listeriolysin hemolysin

Corynebacterium Gram- ____ Are curved pleomorphic rods “ _______ ”

positive Chinese Letters

Corynebacterium Grow readily on _____ agar Catalase & oxidase ______ Usually (motile or non-motile?)

Sheep blood positive Non-motile

Corynebacterium Are Commensals on ____ Some species pathogenic

skin

Two Lethal Pathologies of corynebacterium ______ _______ due to ______

Suffocation Organ damage; Diphtheria Toxin (DT)

Two Lethal Pathologies of corynebacterium Suffocation - edema (i.e., “_______ ”) + ___________ Organ damage due to Diphtheria Toxin (DT). Usually, the ____ (i.e., severe _______ ).

bull neck; pseudomembrane closes airways. heart; myocarditis

Diphtheria (C. diphtheriae) Spreads by ______ _________ increases vascular permeability & promotes spread

droplet Phospholipase D

Diphtheria (C. diphtheriae) ____-coded exotoxin (_____ subunits) acts on _____ mucous membranes interfering with protein synthesis by inactivating ____

Phage; A&B; respiratory; EF-2

Diphtheria (C. diphtheriae) _________ of _____,___,_____,______ impairs breathing

Pseudomembrane of fibrin, bacteria, epithelial & phagocytic cells

Diphtheria (C. diphtheriae) Toxin spreads to _____,_____, and ______

heart, CNS, & adrenals

Diphtheria (C. diphtheriae) Selective media (______-_____ ) Identify in Public Health Labs Protect by _____ vaccination - _____ < ___ cases/yr in US

cysteine-tellurite toxoid; DaPT 5

Diphtheria usually presents as _______ or _____

pharyngitis or tonsillitis

Other Pathogenic Corynebacteria C. __________ C. __________

jeikeium (JK) urealyticum

Other Pathogenic Corynebacteria C. jeikeium (JK) Opportunistic bloodstream infections in ________________ recipients Multiple antibiotic resistance - except _______ and ______ Commonly carried on ______ of ________ persons

bone marrow transplant vancomycin and tetracycline skin of hospitalized

Other Pathogenic Corynebacteria C. urealyticum Occasional cause of ——— and ——— (______)

UTI & stones splits urea

Corynebacterium diphtheria sometimes presents as skin lesions T/F

Spore positioning and species _________ spore C. tetani ________ spore C. perfringens __________ spore C. septicum, novyi, histolyticum difficile, botulinum

Terminal Central Subterminal

Wounds and soft tissue infection ________________ is the most common invasive clostridial species (but other species can cause similar effects – C. novyi, C. septicum) The organism requires_____ tissue with ____ conditions, _____ blood supply, complex nutrients, and ______ ions

C. perfringens type A damaged; anaerobic; impaired Ca++

Wounds and soft tissue infection C. perfringens type A Produces ___ toxins that attack membranes, including: – alpha -toxin (_____, AKA “_____”) –_______________ (hydrolyzes phosphatidylcholine and sphingomyelin-kills cells)

12 lecithinase; myotoxin zinc metallophospholipase

Wounds and soft tissue infection C. perfringens type A Toxins destroy ______, produce ______ Organisms produce ____ when they grow = _______ in tissue

PMNs; myonecrosis gas; crepitance

Anaerobic growth Anaerobes will grow at the ____ of tubes of static nutrient broth

bottom

To separate facultative from obligate anaerobes you must plate out the growth from the _____ of the tubes

bottom

Most obligate anaerobes produce a distinctly ———— odor!!

unpleasant

Clostridial diseases in which culture is not usually done Mention 4

Food poisoning Tetanus Botulism Antibiotic-associated colitis

C. perfringens food poisoning Improperly-handled food is contaminated with spores, which survive ________ Spores germinate with heating ( ________ ) and if > ____/g bacteria are ingested, illness may occur

cooking temperature anaerobiasis 10^5

C. perfringens food poisoning _______ in the small intestine releases ______ Diarrhea (with or without?) fever occurs 6-18 hours later, and resolves in 1-2 days

Sporulation enterotoxin Without

Generalizations about invasive Clostridium spp. ________ is critical for survival in the environment (soil) Disease is mediated by _____-release from _______ cells

Sporulation exotoxin; vegetative

Generalizations about invasive Clostridium spp. Exogenous infections = spores in ________ Endogenous infections = vegetative bacteria released from ________

wounds colonized sites (e.g., colon)

Generalizations about invasive Clostridium spp. Treatment: ————- are effective, but not in ______ tissues; _______ is often required

Simple antibiotics non- viable surgery

Generally, In invasive clostridium spp, Antibiotic resistance is a problem T/F

F Antibiotic resistance is not a problem

Clostridium Alpha-toxin is a _____ that destroy cell membranes, including _____ and _____

lecithinase PMNs and muscle cells.

Clostridium C. septicum bacteremia may signal ______

colon cancer

Clostridial enterotoxin causes a __________________(_________) but is not ______ most cases.

self-limited diarrhea (food poisoning) invasive

Gardnerella _____ is the only species of Gardnerella T/F

vaginalis T

Gardnerella The organisms are (small or large?) (1.0–1.5 μm in diameter) spore or non-spore-forming? motile or nonmotile coccobacilli?

Small Non -spore Non motile

Gardnerella G.vaginalis - ____- hemolytic on media containing _____ or _____ blood but not on _____ blood agar

beta human or rabbit sheep

Bacillus is versatile in degrading complex macromolecules T/F

Bacillus Motile or Non Motile

Non Motile

bacillus can be used as a source of antibiotics T/F

Virulence factors of Bacillus Anthracis _____ ________ ——— _____

Capsule Spores Anthrax toxins Plasmids

Virulence factors of Bacillus Anthracis Spores: resistant to ________ , withstand _______ and certain ____ for moderate periods, and persist for years in dry earth.

environmental changes dry heat chemical disinfectants

Virulence factors of Bacillus Anthracis Anthrax toxins are made up of three proteins, _______,_____, and ________

protective antigen (PA), edema factor (EF), and lethal factor (LF).

In bacillus Anthracis, the same plasmid encode genes for toxin and capsule production T/F

F different plasmids encode genes for toxin and capsule production

3 major types of anthrax Cutaneous( approximately ____% of cases) Inhalation anthrax /____ disease(___%) Gastrointestinal anthrax -very (common or rare?) ;

95 woolsorters;5 Rare

Culture of bacillus Anthracis : • on ___ agar plates •the organisms produce ___hemolytic gray to white, tenacious colonies with a rough texture and a ground-glass appearance. •_____-shaped outgrowths (_____, “_____”) may project from the colony.

blood non Comma; Medusa head; curled hair

Capsule demonstration of Bacillus Anthracis requires growth on ______-containing medium in 5–7% carbon dioxide

bicarbonate

Definitive identification of Bacillus Anthracis requires lysis by a specific _____________ detection of the capsule by _______, or identification of toxin genes by _________. Serology: ELISA

anthrax γ-bacteriophage fluorescent antibody polymerase chain reaction (PCR)

Control measures against bacillus Anthracis include (1) disposal of ____ by ______ or by _____ (2) decontamination (usually by _____) of animal products (3) _______ and ______ for handling potentially infected materials, and (4)_______ of domestic animals and high risk individuals with _________

animal carcasses; burning; deep burial in lime pits autoclaving protective clothing and gloves active immunization; live attenuated vaccines

Both Bacillus _______ and Bacillus _______ may occasionally produce disease in immunocompromised humans

cereus thuringiensis

C botulinum The spores are highly heat resistant can withstand _____°C for _______ Heat resistance is diminished at ____ pH or _______ concentration

100; several hours acid; high salt

C botulinum Toxin is liberated into the environment during the _____ of C botulinum and during ______ of the bacteria ___ antigenic varieties of toxin (__-__) are known

growth; autolysis 7; A-G

C botulinum toxins The lethal dose for a human is probably about __-___μg/kg. The toxins are destroyed by ____ for ____ at _______.

1–2 heating 20 minutes 100°C

C botulinum toxins are among the most toxic substances known T/F

Botulinum toxin is considered to be a major agent for bioterrorism and biologic warfare T/F

Clinical findings of C. Botulinum •Symptoms begin __-___ after ingestion of the toxic food, with _____ disturbances (incoordination of _____, double vision), inability to ____, and _____ difficulty •signs of ____ paralysis are progressive •Death occurs from _______ or ______ •(little or no?) fever and patient remains( not , semi, or fully?) conscious until shortly before death.

18–24 hours; visual; eye muscles swallow; speech; bulbar respiratory paralysis or cardiac arrest. No ; fully conscious

Survivors of botulism develop antitoxin in the blood and the mortality rate is (low or high?) T/F

F do not develop antitoxin in the blood and the mortality rate is high

Treatment of botulism : ——— and _____ Prevention and control: _____ and _____

antitoxin and supportive care Food hygiene ; Preheating of canned food

C tetani causes tetanus produce the toxin ______ and ______

tetanospasmin and tetanolysin

Corynebacterium contain ______ granules that give the ———- appearance

metachromatic rod a beaded

Individual corynebacteria in stained smears tend to lie _______ or _____________ (Chinese lettering appearance)

parallel or at acute angles to one another

L monocytogenes has a tumbling _______ motility at _____°C but not at ___°C

End-over-end 22–28 37

ERYSIPELOTHRIX RHUSIOPATHIAE Causes ______ (usually occurs on the _____ by direct inoculation at the site of a cut or abrasion)

erysipeloid fingers

ERYSIPELOTHRIX RHUSIOPATHIAE there may also be _____ form and _____ with _____

diffuse cutaneous bacteremia with endocarditis.

E rhusiopathiae is unique among gram-positive rods in that it _______________

produces H2S on TSI slant

Actinomycetes Causes _____ form _____ chains with occasional ______ Are acid fast because of ________

actinonycosis elongated; branches the presence of mycolic acid

Actinomycetes _____,_______ and a few others of clinical significance.

Nocardia, Rhodococcus,

________ and _______, two agents that cause actinomycotic mycetomas, are acid-fast stain (positive or negative?) .

Streptomyces and Actinomadura Negative

Nocardia species are _____, beaded gram-positive rods found in soil and other environmental sources

branching

Nocardia species cause _____ disease ( ______ )primarily in immunocompromised patients.

systemic norcadiosis

Gram Positiv Bacilli Flashcards

(109 cards)