Bacteroides, Prevotella, Porphyromonas Flashcards
Anaerobic bacteria can not survive in the presence of _______. They are normally found in the ____ cavity, ___ tract, ______ tract Anaerobic bacteria are both considered to be ______ flora but also ________ pathogens. Form an _____ in which they are safe because protects from ___, host _____ response and _____.
Anaerobic bacteria are ____-______-forming, and can be either Gram- ______ OR Gram- _______.
oxygen, oral, GI, urogenital, normal, opportunistic, abscess, O2, immune, antibiotics, Non-spore, negative, negative
Bacteria that form spores under unfavorable conditions are called ____ forming bacteria and are mostly gram-______.
Examples of Spore forming gram + anaerobic bacteria are?.
Anaerobic Bacteria that do not form spores consist of gram-_____ and gram-_____.
Example of anaerobic gram + bacteria? _______
Example of anaerobic gram -?
spore, +, Clostridium, +, -, Actinomyocin, Bacterioids, prevotella, porphyromonas, fusobacterium.
Oxygen is _____ to obligate anaerobic bacteria
toxic
During reduction of oxygen, highly reactive intermediates such as superoxide ions and hydrogen peroxide are produced (ROS) and should be removed for cells to survive. Aerobic and facultative anaerobic bacteria produce Superoxide dismutase and Catalase makes oxygen less toxic.
Sd converts superoxide ion to hydrogen peroxide and catalase breaks off hydrogen peroxide into oxygen and water.
Bacteria in the air, then leaving the air, require superoxide dismutase and ?. Anaerobic bacteria do not produce superoxide dis utase, whihc is why oxygen is toxic to anaerobic bacteria.
Obligate anaerobes do not produce
_______ _____ and ______.
superoxide dismutase, catalase
Normal flora of animals and humans can be found on:
1. _____ _________
2. ____________ tract
3. ______ cavity
4. _________ tract
5. Protect against _______ at ________ surfaces
mucous, membranes, Gastrointestinal, Oral, Urogenital, pathogens, mucosal
Facilitating host metabolism and immune response. Protect cells against pathogens.
Opportunistic pathogens will act differently in each of the locations below. List what would happen if opportunistic pathogens penetrated the protective barriers in each location.
1. Gastrointestinal tract
2. Oral cavity
3. Urogenital tract
Protect against pathogens at mucosal surfaces
- IBD
- Periodontal disease
- PID, UTI
Polymicrobial nature
* Synergism with _____ ______ bacteria
* _____ spectrum ______ required due to polymicrobial nature.
facultative, anaerobic, Broad, antibiotics
Infection caused by multiple microroganisms is called polymicrobial infections whihc is common in anaerbic bacteria.
Explain what is happening in the image pictured
facultative anaerobices scaveneger oxygen which facilitates anaerboci bacteria to grow. anaerobic bacteria prives safe home for fac anaerobes as they produce abscess adn metabolites against antibmicrobial and phagocytes.
List the virulence factors
LPS = endotoxins
Frimbriae/Pilli = attachment ot host cell
Toxins = tissue damaging
Capsule = most important; antiphagocytic and reduces abscess formation.
Abscess formation
An abscess is a collection of ____ that has the buildup of ___, ____ and dead ____ blood cells, ____ tissue, and _______.
pus, fluid, living, white, dead, bacteria
Abscess can protect bacteria from phagocytosis and antibiotics.
Can be formed anywher in body from skin ot intenral organs such as the brain and liver.
Bcteria are confined in abscess wehre WBC try to get rid of pathogens. It is a host immune respinse. When bacteria are isolated, however, anaerobic bacteria cna escape abscess and ente rblood stream –> bacteremia. CAn cause systemic infeciton affecting entire body.
Diagnosis of anaerobic infections
–> Sampling
- Locations? (3)
- _____ transport of samples in ______ transport media
–> Isolation of bacteria
- _______ media required for growth
(vitamin __ and ______)
- ______ culture in a chamber, jar,
container, or bag
pus, discharges, or tissues, Rapid, anaerobic, Enriched, K, hemin, Anaerobic
Diagnosis of anaerobic infections
–> Microbiological analysis
- Colony _____
- ____ staining
–> ___ analysis for ___ genes
–> Serological test
- ____
–> Cytological analysis
- Abundant degenerative ______
morphology, Gram, PCR, toxin, ELISA (antibodies against pathogens in blood or serum), neutrophils (tissue biopsy or body fluids and looks at cell types)
Treatment of anaerobic infections:
1. _______ intervention
2. _______ therapy. Caveat?
Surgical, Antibiotic
surgical: abscess is open and drained
2. Some strains are resistant to beta-lactams such as penicillins and cephalosporins; BUT Metronidazole, carbapenems, β-lactam with β-lactamase inhibitors, and clindamycin are generally effective
Genus: Bacteroides
- Non-____-forming, Gram-______, ________, ___-resistant, _______ rods
- ________ anaerobes
- Produce ______ polysaccharides
- Produce ____-chain fatty acids (SCFAs)
- Resistant to common _____
- Normal flora of the ?
- ___% of the total colonic bacteria
- Some species are _____ pathogens
- The most clinically significant pathogen:
- ?
spore, negative, pleomorphic, bile, anaerobic, Aerotolerant, capsular, short, antibiotics, GI tract, oral cavity, and , opportunistic, urogenital tract, 30, Bacteroides fragilis
Bile functions are biological detergent; permeabilizes bacterial membranes and eventually leads to cell lysis. Bile tolerance is essential to survive in the gut.
Aerotolerant: can survive in environment with oxygen because produce SOD and catalase.
______________ _______________ is a key characteristic of bacteroides
Capsular polysacharides
Bacteroides smells really bad because of ________ __________ ________ _______, which is a signature presentation of an anaerobic infection.
short chain fatty acids
Most prevalent bacteria in the gut?
Bacteroides
Bacteroides
Long filamentous folds, pleomorphic
List the Virulence factors of Bacteroides
- Fimbriae, agglutinins - Fuction as adhesions, allowing them to be established in tissues.
- Capsular polysaccharides
- Help adherence to peritoneal surfaces
- Inhibit phagocytosis
- Cause abscess formation - LPS
- Endotoxin
- Adhesion - Enzymes
- Zinc metalloprotease = ? damage
- Protease
- Hemolysin = lyse host cell membrane - Short chain fatty acids which Inhibit phagocytosis and intracellular killing
LPS = endotoxin. LPs and capsule may help adhere to host cell ad produce many enzymes such as SOD and catalse; not virulence facotrs, but mae them survive under oxudative stress.
Bacteroides
Bacteroides produce SCFAs
Short-chain fatty acids: Propionate, Butyrate, Acetate
Major metablites produced in colon during bacterial fermentation.
SCFAs have beneficial effects on gut health
- Energy source for colonic epithelial cells
- Help protect from pathogens
- Anti-inflammatory and anticancer effects.
Cons
Some SCFAs are bad
1. Modulate host immune response, and delay elimination of pathogen can lead to Chronic inflammation
But generally beneficial
Cultures of Bacteroides:
1. TSA with 5% ___ blood
2. Bacteroides ___ ____ Agar
* Circular, entire, ____ or ___ 2- to 3- mm colonies that are ____ and ____
* Resistant to penicillin, kanamycin, vancomycin and colistin
* ___ tolerance
* Anaerobic incubation ≥ __ hours
sheep, bile, Esculin, white, grey, shiny, smooth, Bile, 48
Are fastidious bacteria so grow on enriched media.
Can also grow on agar with antibiotics but others can not.
Esculin agar is TSA supplemented with 20% bile?
Common infections caused by Bacteroides. Bacteroides infection are related ot naturla habitat, bbite wounds, and spread through blood. Do not need to know chart.
Describe Bacteremia after a cat bite.
3 days later went to hospital after cat bite. Sample from wound and prescribed penicillin antibiotics. 8 days, owner admitted to ER b/c of thoracic pain and general ?
Bacteremia post cat bite
Clinical symptoms
Bacteremia post cat bite
Cytological analysis
Bacteremia post cat bite
Microbiological analysis
Bacteremia post cat bite
Molecular analysis
Bacteroides infection was treated with?
- Abscess drained (surgically)
- Antibiotics - determined based on AMR testing.
No blood supply to delivere antibiotics in abscess; could difuse via concentration gradient but is slow and unreliable. ph in abscess is low, so antibitics are designed to wok in neutral ph; low ph - antibiotics wont work. Hence why you need to drain, in order to improve therapeutic efficacy of antibiotics.
Vulvar abscess caused by Bacteroides sp.
in a 3-year-old dachshund
Neutrophils and bacteria on histo.
Pus cultured on blood agar aerobically and anaerobically. Bacteria only grew on anaerobic blood agar and identified as bacteroides speices b/c grew on bile esculin agar, whihc is selective for bacteroides. Prescribed oral ampicillin because bacteria susceptible to it.
The genus Bacteroides, Prevotella, and Porphyromonas are members
of the phylum _________
Bacteroidetes
Prevotella
Short, Gram-_____, obligate ______ ___ (coccobacilli)
Resistant to _____ and _____
Normally found in the ___ cavity and the ___
Most clinically significant pathogens?
Virulence factors?
negative, anaerobic, rods, kanamycin, vancomycin, oral, gut
- P. melaninogenica (interdigital necrobacillosis in cattle)
- P. heparinolytica (lesions in the buccal cavity in horses and cats)
- Capsule = contributes to host adhesion, abscess formation, and protection from phagocytosis.
- Protease
- T9SS (specific to Bacteroidetes)
Prevotella produce _______
* The good or the baddy?
Inhibit phagocytosis of?
Play a role as a __-_______ mediator
Improve ____ homeostasis
succinate, polymorphonuclear leukocyte, pro-inflammatory, glucose
Septicemia in a 6-year-old Holstein cow
Porphyromonas
____-_____-forming, Gram-____, non- _____, obligate _____ ___ or coccobacilli
Asaccharolytic = ? but Proteolytic
Small, ____ colonies on ____ agar
(_____ pigment)
A member of oral microbiota in humans and animals
An etiological agent of periodontitis
Clinical species?
Sensitive to ____
Resistant to ____
Non-spore, negative, motile, anaerobic, rods, black, blood, porphyrin
unable to ferment cabohydrates for energy and instad are proteolytoc therfore digest proteins into small peptides and ferment them. explains why porphyromonas can survive in deep periodontal pockets where? is scarce?
- P. gingivalis (human pathogen)
- P. gulae (animal pathogen)
vancomycin, kanamycin
Virulence factors of Porphyromonas?
- Capsule
- Adhesion
- Abscess formation
- Protection of phagocytosis - LPS
- Endotoxin - Fimbriae: FimA, Mfa1
- Adhesion and invasion of cells and tissues
- Interact with other bacteria (biofilm) - Proteases: Gingipains = provide nutrients through protein degradation
- Nutrient acquisition
- Adhesion and tissue invasion
- Destruction of host tissue
- Dysregulation of host immune responses
Periodontal disease is one of the ___ common diseases in dogs (present in almost __% of dogs).
_______ ___ is a major bacteria associated with periodontal disease in dogs.
Dogs with major plaque were treated with clindamycin (effective in control porphyromonas species) and interferon-a (suppresses inflammatory responses of epithelial cells).
most, 80, Porphyromonas gulae
Bile functions as a biological ___________. It permeabilizes bacterial _________ and eventually leads to cell ______. Bile tolerance is essential to survive in the ______.
detergent, membranes, lysis, gut
Aerotolerant: can survive in the environment with ________ because produce ____ and _____.
oxygen, SOD, catalase
