Microbio Week 2 (Exam 1) Flashcards
Ideal antibacterial agents are __________, which means it will _____ the bacteria
bacteriocidal; kill
The ideal antibacterial agent comes as _______ and _______ preparations
oral; injected
An ideal antibacterial agent has a ___ half-life in plasma and ___ binding to plasma proteins
long; low
T/F We want the ideal antibacterial agent to be wide spectrum
FALSE, we want it to be narrow spectrum
Which antibiotic is described as “narrow” spectrum?
Penicillin V
Isolation of clinical strains of bacteria resistant to specific antibiotics typically occurs within ________ _______ of introduction of specific antibiotic therapy
several years
Which beta-lactam antibiotic has broad spectrum activity against bacteria resistant to penicillins and cephalosporins?
Carbapenem
(MRSA) methicillin-resistant S. aureus describes…
a group of antibiotic resistant strains of S. aureus
What experiment proved that genes that code for antibiotic resistance were in the gene pool before humans began to produce antibiotics?
‘Replica Plate’ experiment
T/F: the number of companies in the US researching/developing antibiotics has steadily increased since 1990
FALSE, it has declined
Due to resistance, we now have ‘carbapenemase’ producing bacteria like _______ ________
Klebsiella pneumoniae (KPC)
ID of bacteria can combine ___________ sensitivity and _______________ reactions
antibiotic; biochemical
What is this describing?
Bacteria streaked on plate, then antibiotic-impregnated discs put on plate and incubated overnight to allow growth
Laboratory antibiotic sensitivity test
Lowest concentration of antibiotic needed to inhibit growth of bacteria
Minimum inhibitory concentration (MIC)
Lowest concentration of antibiotic needed to kill bacteria
Minimum Bactericidal Concentration
Bacteria in ________ may be up to 1000x less sensitive to antibiotics than bacteria in ________
biofilms; solution
What test is used to determine the MIC (inhibit growth) and MBC (bacteriocidal)?
Inoculum test of bacteria
What % of antibiotics are prescribed by dentists according to Dr Graham?
10%
Antibiotics should NOT be prescribed for upper respiratory tract infections EXCEPT when…
Lab confirmed strep throat
Cough lasting 10 days
Advanced sinusitis
Half of all upper respiratory tract infections are _______
viral
T/F: For the best practice and answers, bacteria should be isolated, identified, and tested for antibiotic susceptibility profiles
True (but this takes time)
If you do not have time to isolate, identify, and test the bacteria for antibiotic susceptibility, then antibiotics must be selected based on __________ bacterial species for common clinical syndrome and _________ knowledge about antibiotic susceptibility
presumed; current
What are common infections in dentistry that must be treated with antibiotics?
- Facial cellulitis
- Aggressive acute necrotizing ulcerative gingivitis
- Lateral perio abscess
- Acute periocoronitis w/ systemic signs
What are 2 other indications for antibiotics in dentistry?
Oral infection with increased body temp
Evidence of systemic spread (trismus, lymphadenopathy)
Most orofacial infections are ________ _________ of normal flora and (are/are not) resistant to beta lactams.
However, __________ of lesions will often be all that is needed (no antibiotic)
mixed anaerobes; are NOT
draining
Facial cellulitis (soft tissue infection) must be treated ASAP with antibiotics because of a potential to develop ______
septicemia
How does facial cellulitis spread to cause septicemia?
Through the blood and lymph
T/F: drainage of dental infections without medication may often be sufficient to solve the infection
True
Antimicrobials are used prior to surgery/procedures (prophylaxis) in dentistry only when…
- Risk of post-op infection is high
- Wounds are contaminated and there is risk of infection
- Consequences of infection are serious or life threatening
- The pt’s defenses against infection are compromised (elderly, fragile, etc)
What 4 conditions indicate routine antibiotic prophylaxis to prevent infective endocarditis from dental procedures?
- Artificial heart valves/parts
- History of infective endocarditis
- Some congenital heart conditions
- Heart transplant recipients with valve problem
T/F: all patients with a prosthetic joint should have antibiotic prophylaxis
false - this was changed in 2021 to only patients with a history of infection
Which antibiotic is no longer indicated for a patient with penicillin allergy?
Clindamycin
What antibiotics are most commonly used by dentists?
Beta-lactam
Beta-lactam antibiotics have activity against bacterial species often present in infections of the head and neck, especially ___________ bacteria
Gram +
T/F Many people are allergic to beta-lactams
FALSE, only about 3% of people are allergic
________ _________ is acid labile, so it is best administered parenterally (IM injection), and can be inactivated by gastric acid
Benzyl penicillin (penicillin G)
What forms of penicillin are relatively acid stable and therefore more appropriate for oral administration?
Penicillin V
Amoxicillin
Which antibiotic is an alternative to Beta-lactams?
Metronidazole
__________ is an antibiotic which targets anaerobic bacteria (obligate, not facultative) and can be used for periodontal disease and complications
Metronidazole
Metronidazole should be considered when there is no improvement with _________ or _________ for ___ hours
penicillin; amoxicillin; 48
T/F: Patients are allowed to drink alcohol when taking Metronidazole
FALSE!!!! It is known to have major reaction issues!!
He said this many times in lecture too
Which antibiotic is the treatment of choice for acute uclerative gingivitis, rapidly progressive perio disease, and patients with serious anaerobic infections?
Metronidazole
For juvenile periodontitis, which medication is preferred?
Doxycycline
Diarrhea is a common side-effect of oral __________ and can be a risk for ___________ _________
Clindamycin; Clostridium difficile (4x)
What are some other alternative antibiotics for beta-lactam allergies (penicllin)?
Macrolides: Erythromycin, Azithromycin, Clarithromycin
Lincosamides: Clindamycin (only in tx of high risk or bone involvement)
What do macrolides and lincosamides inhibit?
Protein synthesis at ribosome
____________ are an equally good 3rd option as alternative for beta-lactams, but only when Gram - resistance is known or suspected
Quinolones
Which antibiotic causes permanent discoloration of developing teeth?
Tetracycline
Chlorhexidine diacetate is a chemical _________ that has bacteriocidal activity against many ______ and ______ oral bacteria
antiseptic; Gram +; Gram -
Fluoride has an antimicrobial effect of inhibiting _________
enolases
What are bacterial glycolytic enzymes called?
Enolases
Fluoride reduces cavities by ____
20-60%
What are 3 conditions where antibiotics are no longer recommended because they may do more harm than good?
- Mitral valve prolapse (MVP)
- Rheumatic heart disease
- Bicuspid valve disease
Staph aureus usually has a _____________ pigmentation but clinical isolates have a ___________ pigmentation
golden; creamy
Is Staph aureus coagulase positive or negative?
Coagulase positive
What color are the colonies that Staph epidermis produces?
White
Is Staph epidermis coagulase positive or negative?
Coagulase negative
What unique characteristic does Staph aureus have on blood agar plates?
Beta hemolytic
How do Staph aureus and Staph epidermis inhabit humans?
Staph aureus = anterior nares
Staph epidermis = skin
Which bacteria are the largest cause of a variety of hospital acquired infections?
Staph aureus and Staph epidermis
Which bacteria is a major cause of food poisoning?
Staph aureus
_______ ___________ is more limited in causing foreign body colonization (shunts, catheters, joint prostheses), leading to local pathology - occasionally bacteremia and endocarditis
Staph epidermis
Staph aureus and Staph epidermis are increasingly _________ _________
antibiotic resistant
Both Staph aureus and Staph epidermis produce _________ and inhibit ________________, which allows __________
capsules; phagocytosis; bacteremia
What does Staph epidermis produce that helps it adhere to smooth surfaces such as catheters?
Slime
Common skin infections caused by Staph aureus
Boils
Pimples
Scalded skin syndrome (babies)
Sialidentitis aka parotitis (infection of salivary gland)
Sinusitis
More serious infections caused by Staph aureus
Endocarditis
Osteomyelitis
Pneumonia
Septicemia
Toxic shock
Infection or swelling of the salivary glands is called?
Sialidentitis (parotitis)
Lip irritation caused by infection, irritation, or allergies is called?
(can be infected by Candida albicans or Staph aureus)
Angular cheilitis
Dental infection w/ rapid onset where the floor of the mouth is raised and there is difficulty swallowing saliva
Ludwig’s angina (facial cellulitis)
What are 3 metastatic infections of Staph aureus (bloodstream invasion capable of spreading to any area of body)?
Osteomyelitis
Arthritis
Endocarditis
Most common bone infection caused by wound infection with trauma to the bones
Osteomyelitis
Dissemination from skin via blood to joint, destruction of cartilage and permanent joint deformity
Arthritis
Infection of innermost layers of the heart and can occur in pts w/ congenital valve disease
Endocarditis
What bacteria is most commonly associated with endocarditis?
Staph aureus
What are the most common valves affected in endocarditis?
Aortic and mitral valves
What are the 4 most widely known virulence factors for Staph aureus?
Adhesins
Exported toxins/enzymes
Coagulase
Catalse
What virulence factor of Staph aureus causes clotting and bacterial adherence?
Coagulase
What virulence factor of Staph aureus detoxifies neutrophil oxygen radical killing?
Catalase
What parts of Staph aureus act as virulence factors?
Peptidoglycan
Techoic acid
Like Gram negatives, Staph cell wall components are _________
inflammatory
Which Staph aureus cell wall virulence factor is antigenic, has endotoxin-like activity, and is inflammatory?
Peptidoglycan
Which Staph aureus cell wall virulence factor is a major surface antigen and inflammatory?
Teichoic acid
Major protein component of cell wall that is antigenic and has non-specific interaction with Fc of immunoglobulins, interfering with opsonization (ex: anti-phagocytic)
Protein A
What are the 5 exotoxins that are part of Staph aureus’s virulence?
Hemolysins
Leukocidans
Entertoxins
Exfoliative
TSST-1
Which pore-forming hemolysin of Staph aureus produces the most extensive tissue damage?
Alpha toxin
What do alpha toxins lyse?
WBCs, RBCs, other tissue cells
Important in immune evasion as they act exclusively on immune phagocytes
Leukocidans
Staph aureus _____________ are related to _________ poisioning
enterotoxins; food
Which Staph aureus secreted toxin cleaves the upper layer of the epidermis resulting in “scalded skin syndrome”?
Exfoliative
Which Staph aureus secreted toxin causes fever, erythroderma, and enhances susceptibility to endotoxin shock from Gram - LPS?
TSST-1
(toxic shock syndrome - 1)
What are adhesins?
Cell bound proteins
(virulence factor for Staph aureus)
How do you treat a Staph aureus infection?
Clean wounds, drain abscess, remove foreign bodies, topical antibiotics (ex: neosporin)
If it’s serious -> beta-lactams or vancomycin
What do Staph aureus and Strep pyogenes have in common?
Both Gram + cocci
Streptococcus is a Gram ____________ cocci that grows in pairs and chain using ____________
+ ; fermentation
The pathogenic species of strep have ___________ and __________ which are used to evade ___________
capsules; M protein; phagocytosis
Group A strep (Strep pyogenes) causes?
Strep throat
Scarlet fever
Necrotizing fascitis
Rheumatic heart disease
What bacteria is Group A strep?
Strep pyogenes
What bacteria is responsible for the most common visit to the doctor (upper respiratory) and most common for meningitis?
Strep pneumonia (‘mitis’)
What bacteria plays a role in dental caries and periodontal disease?
Strep mutans (‘mutans’)
Which Strep bacteria are in the ‘viridans’ group?
Strep pneumonia (‘mitis’)
Strep mutans (‘mutans’)
How do we differentiate different Streps?
- Hemolysis on blood agar plate
- rRNA
What type of hemolysis is Strep pyogenes?
Beta hemolytic
What type of hemolysis is Strep pneumonia?
Alpha hemolytic (also called alpha green)
What type of hemolysis is Strep mutans?
Alpha hemolytic (also called alpha green)
These bacteria have the most identifiable gene coding capacity for virulence factors of known bacterial pathogens
Strep pyogenes (Group A strep)
Strep are a clear example of __________ in bacterial disease in relatively recent lifetimes
evolution
T/F: Strep evolve quickly and exchange DNA by transformation among many Strep ssp that live on and in the body
True
_______ ________ causes even more diverse infectious diseases than Staph aureus
Strep pyogenes
If a pt comes in with a rash and red tongue aka scarlet fever, which strep are they infected with?
Strep pyogenes
Examples of skin and soft tissue infections caused by Step pyogenes
Impetigo/cellulitis
Erysipelas (similar to Staph aureus)
Necrotizing fasciitis
Streptococcal toxic shock syndrome (STSS)
Examples of respiratory infections caused by Strep pyogenes
Strep throat
Scarlet fever
Pneumonia
Pneumonia caused by Strep pyogenes is often preceded by what?
A viral infection
What is Strep pyogenes TSS caused by?
Bacteria enter the bloodstream and secrete super antigen proteins
What do the super antigen proteins do in Strep pyogenes TSS?
Lock T-cells onto antigen presenting cells
Name some components of the cell wall that are virulence factors of Strep pyogenes
Since it’s gram + it will have:
Peptidoglycan
Teichoic acid
What is the KEY virulence factor in Strep pyogenes that extends out from the surface of the cell?
M protein
This protein belonging to Strep pyogenes inhibits complement fixation and opsonization, thereby inhibiting phagocytosis
M protein
What does the M protein of Strep pyogenes bind to?
Host peptides with roles in immunity
M proteins are long, ________ molecules
fibrillar
T/F The M protein is variable, and is the basis for >200 serotypes
True
Another Strep pyogenes virulence factor is the conventional capsule. What is it made of and what is its purpose?
Made of polysaccharides
Purpose = inhibits phagocytosis (but less important than M protein)
Name 2 exotoxins that serve as Strep pyogenes virulence factors
- Cytolytic exotoxin = “streptolysin” O and S -> beta lysis on blood agar
- Pyrogenic exotoxin = superantigens that cause scarlet fever
Name 2 superantigens of Strep pyogenes that are inflammatory. Where are they encoded?
- SpeA
- SpeC
Encoded on phages
This protein of Strep pyogenes allows for non-specific binding to Fc of immunoglobulins, interfering w/ opsonization (inhibits phagocytosis)
Protein G
What is Protein G of Strep pyogenes similar in function to?
Protein A of Staph aureus
How is Strep pyogenes transmitted?
Direct skin contact
Respiratory droplets
Exchanging secretions via close physical contact
How do we treat Strep pyogenes?
Topical antibiotics for skin (neosporin)
PENICILLIN!!
for invasive disease and STSS use injectable penicillin G, but you may have to add clindamycin
T/F There is a vaccine for Strep pyogenes
FALSE!
What did Griffith observe when he injected a mixture of heat-killed, disease-causing bacteria and live harmless bacteria into mice?
Nonvirulent bacteria turned into virulent and the mice died
T/F: In Griffith’s experiment, the bacteria that had a capsule were responsible for killing the mice
True
What do Staph aureus and Strep pyogenes have in common?
They both cause toxic shock syndrome (TSS)
Strep pneumoniae is usually isolated from what area in healthy individuals?
upper respiratory tract
Strep pneumoniae is the most frequent cause of what disease in infants and children?
Otitis media (ear infection)
What is the major cause of community-acquired pneumonia with half a million cases per year in the US?
Strep pneumoniae
What is the most common cause of bacteremia and meningitis in all ages, and the most common cause of meningitis in adults?
Strep pneumoniae
Which bacteria might get released into the bloodstream during a cleaning and land on a heart valve?
Strep oralis
(‘mitis’/’oralis’ group)
What group do Strep pneumoniae and Strep oralis fall under?
‘Mitis’
Strep pneumoniae, Strep oralis, and Strep mutans undergo __________ hemolysis
alpha
What does alpha hemolysis indicate?
Incomplete lysis of RBC’s (partial hemolysis)
Zone of “greening” under & around colonies
ONLY in streptococci
Which bacteria are in the ‘Mitis’ (aka oralis) group?
Strep oralis
Strep (para) sanguis
Strep mitis
Strep gordonii
Strep pneumoniae
Strep pneumoniae have a unique morphology when examined microscopically.
Describe their appearance
Gram + diplococci - they do NOT form chain
T/F: Pneumonia is the #1 community acquired disease
True
Strep pneumoniae are potentially invasive, although they can live without __________ in the upper respiratory tract
tissue
Name the disease:
Rapid onset, shaking chills fever, cough with copious “rusty” sputum
X-ray shows heavy consolidation - lobar
Pneumococcal pneumonia
T/F: There is only 5% fatality when treated for pneumonia
True
There is a potential for pneumococcal pneumonia to lead to ?
Bacteremia, and then endocarditis, septic arthritis, and meningitis
An adult w/ pneumonia has an additional risk of meningitis. How does the fluid travel to the meninges?
Spread from pleura via lymphatics to bloodstream to meninges
How to diagnose strep pneumonia
Gram stain of normally sterile specimens such as:
Blood
CNS fluid
Sputum
T/F: Strep pneumonia is very sensitive to penicillin
False! it used to be, but now there is increase in % of penicillin-resistant strains
Major virulence factor of Strep pneumoniae
Polysaccharide capsule
What are the 2 exotoxin virulence factors for Strep pneumoniae?
- Pneumolysin
- IgA1 protease
This exotoxin for Strep pneumoniae is:
Oxygen labile (only observed anaerobically)
Cross-reacts with streptolysin O
Beta hemolytic (anaerobic only); kills phagocytes
Pneumolysin
This exotoxin for Strep pneumoniae is:
Thought to aid in colonization of mucosal surfaces
IgA1 protease
(cleaves sIgA)
Is there a vaccine for Strep pyogenes?
NO
What is unique about the new heptavalent vaccine for preventing bacteremia, meningitis, and pneumonia?
It’s conjugated to a diptheria toxin mutant protein (safe for infants)!
What is the pneumococcal conjugate vaccine called?
PCV7
As of 2010, which vaccine is preferred from PCV7?
PCV13
(has 6 added purified capsules to cover more serotypes)
Name 3 Gram - respiratory pathogens that all have vaccines
Neisseria meningitidis
Haemophilus influenzae
Bordetella pertussis
These bacteria are very distinctive for their Gram - diplococci in classic kidney bean shape
Neisseria
Only reservoir for Neisseria
Humans
What do Neisseria live on in the human body?
Mucosal surfaces
Are Neisseria catalase positive or catalase negative?
Catalase +
Two main Neisseria groups
1) N. meningitidis
2) N. gonorrhea
This bacteria is closely related to Neisseria and is now a common cause of otitis media in children
Moraxella catarrhalis
For Neisseria, the _________ _________ is important in transmission (asymptomatic)
carrier state
What is the susceptible age group for N. meningitidis?
College students
(and anyone else living in close quarters - military recruits, boarding schools, etc)
How is N. meningitidis spread?
Large respiratory droplets
(you have to be pretty close to a person to get it)
Where is a N. meningitidis infection located in the body? What are 2 routes it can take?
Upper respiratory tract
Person can become a carrier or have severe disease (systemic inflammation and/or meningitis)
T/F: N. meningitidis is intracellular
False! It’s extracellular
How is gonorrhea transmitted? is it intracellular or extracellular?
Direct genital contact
Always extracellular! It attaches to epithelial cells on surface
T/F: Gonorrhea rarely spreads to the bloodstream
True, it typically remains localized in one part of the body
What can N. gonorrhea lead to in women?
Pelvic inflammatory disease
Why is it difficult to treat gonorrhea with antibiotics?
It is drug resistant to beta-lactams and tetracyclines
Why is it difficult to make a vaccine for N. gonorrhea?
It has variable LPS/LOS
What is the septicemia stage of N. meningitidis called?
Meningococcemia
How is Meningococcemia spread to the bloodstream?
Via lymph
What is LPS/LOS endotoxin shock, as seen in Meningococcemia?
When there are large numbers of N. meningitidis (Gram -) bacteria in the bloodstream, and it is exposed to LPS/LOS
(this causes a big inflammatory rxn that is multi-organ systemic shock)
How does someone get meningitis?
N. meningitidis spreads to the meninges and causes inflammation
What could happen if a young child develops meningitis?
Neuromotor disabilities
Seizure disorders
Learning difficulties
Virulence factors of N. meningitidis include something called LOS. What is different about LOS compared to LPS? (on exam)
LOS has no O-antigen!!!
Name the N. meningitidis virulence factors
Capsule
LOS
Pili (fimbriae)
Exo-enzymes (IgA1 protease)
What exo-enzyme does N. meningitidis make? What does it aid in?
IgA1 protease; aids in colonization
What does LOS mimic?
Human carbohydrate patterns
LOS is considered an __________
endotoxin
Which virulence factor is used in the vaccine against N. meningitidis?
Capsule
How do you treat N. meningitidis infections?
Penicillin G
Supportive care for septic shock, DIC, meningitis (antibiotics alone not sufficient bc it doesn’t get rid of the endotoxin)
2 vaccines that help prevent N. meningitidis
1) Menomune ACY/W - purified capsule polysaccharide (works on adults only)
2) New ACY/W Conjugate vaccine - purified capsule polysaccharide conjugated to protein (works on children + adults)
The US now sees mostly _____ capsule strains for N. meningitidis, where there is now a recently available vaccine
B
What are the 4 components of the 4CMenB vaccine?
2 outer membrane proteins
1) Neisseria adhesin (NadA)
2) Heparin binding antigen (NHBA)
3) Factor H binding protein (fHbp)
4) Outer membrane vesicles (OMV)
All Gram - bacteria release ______ or ________ _________ _________
blebs; outer membrane vesicles
What do bacteria of the Haemophilus genus and Bordetella genus look like?
Small Gram -
Coccobacilli
Major Haemophilus pathogen
H. influenza
H. influenza is most similar to
Strep pneumoniae
Non-invasive infections of H. influenzae usually originate from __________ ________ ______ strains (no capsule)
existing normal flora
What does H. influenzae cause?
Ear infection
Sinusitis
Pink eye
Pneumonia
Invasive infections of H. influenzae spread _________ by type _____ capsule strains (this is uncommon because of vaccine)
systemically; B
What can invasive infections of H. influenzae cause?
Septicemia
Meningitis
Who is most at risk for developing Septicemia and Meningitis from an invasive H. influenzae infection?
6 month - 2 yr olds
Name the virulence factors of H. influenzae. Which one is the major virulence factor?
Capsule (major virulence factor)
LOS
Exo-enzymes (IgA1 protease)
Which bacteria all share the exo-enzyme, IgA1 protease?
H. influenzae
N. meningitidis
Strep pneumoniae
Which bacteria share the virulence factor LOS?
H. influenzae
N. meningitidis
Describe the first conjugate vaccine for H. influenzae
Type B capsule covalently linked to a protein
What 2 other pathogens is N. meningitidis (Gram -) often compared to because they cause blood infection, then meningitis?
H. influenzae (Gram -)
Strep pneumonia (Gram +)
Which bacteria are the termed “the triplets”? What do they all do?
The triplets = N. meningitidis + H. influenzae + Strep pneumoniae
Respiratory, encapsulated -> bloodstream -> meningitis
T/F: H. influenzae, N. meningitidis, and Strep pneumoniae all cause meningitis
True
What bacteria is Bordetella similar to?
Haemophilus
(Recall they are both small Gram - coccobacilli)
T/F: B. pertussis is in the normal flora
FALSE
T/F: People can be carriers of B. pertussis
FALSE, you can only get infection, not be a carrier
Where is B. pertussis found in humans?
Nasopharynx (only when the disease is present)
Newborns are very susceptible to B. pertussis because due to lack of __________ __________
maternal antibodies
B. pertussis attaches to _______ and secrete exotoxins that kill epithelial cells
cilia
The toxins produced by B. pertussis inhibit _________
phagocytosis
Describe the paroxysmal stage of B. pertussis
Repeated coughing w/o breathing with an inspirational “whooping” sound when a breath is taken
What are the virulence factors of B. pertussis?
LPS
Outermembrane proteins
3 secreted extracellular toxins
What are the 3 extracellular toxins secreted by B. pertussis?
- Pertussis toxin
- Adenylate cyclase toxin
- Tracheal cytotoxin
The pertussis toxin (virulence factor of B. pertussis) inhibits phagocytosis by inhibiting which specific cells?
Monocytes and neutrophils
What is the major component of the acellular B. pertussis vaccine?
Pertussis toxin
What does the tracheal toxin (virulence factor of B. pertussis) inhibit and trigger?
Inhibits ciliated epithelial cells
Triggers inflammation
What is the tracheal toxin (virulence factor of B. pertussis)?
A peptidoglycan monomer
What are the components of B. pertussis vaccine? What pathogens are covered?
FHA + pertussis toxoid + minor components
(DTaP = Diptheria, Tetanus, acellular Pertussis)
T/F: We have a fairly stable (60-70%) microbiota over time (usually 5 years)
True
What is the stability of our microbiota largely due to?
Bacteriodetes firmicutes
Actinobacteria
(proteobacteria come and go)
4 major sites of colonization
GI tract
Mouth/upper respiratory
Skin
Urogenital tract
This bacteria is acquired in the birth canal by the fetus
Bifidobacterium
(Gram +, anaerobic rods)
How do fetuses obtain microbiota?
Through maternal milk
Disruption of early microbiota predisposes to what 3 things?
Allergy
Asthma
Obesity
In the GI tract, the epithelial surfaces of the small and large intestines are colonized. Describe the amount in each
Small intestine: low numbers
Large intestine: high numbers
Most abundant bacteria found in the intestine
Bacteroides (Gram - rods)
Clostridium
T/F: Bacteroides are strict aerobes.
False! They’re strict ANAEROBES
Bacteroides make up ____% of gut bacteria
30%
What is the major role of bacteroides in the gut?
Process complex molecules
Break down plant glycans/carbohydrates!!
Most abundant species of bacteria in the human gut is Bacteroides ____________
thetaiotamicron
Where do oral bacteria colonize?
Lip
Cheek
Palate
Tongue
Teeth
Gingiva
Saliva
T/F: The areas of colonization in the oral cavity all have their own flora.
True
Abundant types of bacteria in the mouth
Streptococcus
Many obligate anaerobes
Diptheroids
Lactobacillus
Neisseria
What are the important obligate anaerobes that are found in tooth plaque and gingiva?
Porphyromonas gingivalis
Tannerella forsythia
Treponema denticola
Fusobacterium
Prevotella
Peptostreptococcus
Actinomyces
Predominant obligate anaerobes in periodontal disease
Porphyromonas gingivalis
Tannerella forsythia
Treponema denticola
Predominant obligate anaerobes in ulcerative gingivitis
Treponema denticola
Fusobacterium
Prevotella
What is the flora in the respiratory tract very similar to?
Mouth
Sites of colonization in upper respiratory tract
Epithelial surface of nasal cavity, nasopharynx, and oropharynx
Sites of colonization in lower respiratory tract
Trachea, bronchi, lungs (kinda controversial due to transient inhaled bacteria)
Abundant types of bacteria in the upper respiratory tract (7)
Streptococcus
Haemophilus
Neisseria
Moraxella
Staphylococcus
Diptheroids
Mycoplasma
Name 3 aerobic Gram + cocci found on the skin
Staph epidermis
Staph aureus
Micrococcus
Name 2 diptheroids found on the skin
Cornyebacterium
Propionibacterium
Which diptheroid is found in hair follicles?
Propionibacterium
Propionibacterium feed on oil in hair follicles and cause what?
Acne
T/F: The flora on your left hand can be different from your right hand
True
Sites of colonization in the genitourinary tract
Epithelial surface of anterior urethra, vagina, cervix
Where can intestinal microbiota spread to?
Adjacent areas such as vagina and urinary tract
Normal, healthy bacteria found in the vagina/cervix
Lactobacillus
Name the predominant bacteria found in the vagina/cervix
Lactobacillus
Intestinal bacteria: streptococci, E. coli, intestinal anaerobes
Skin bacteria: staph, diphtheroids
Clinical dentistry indicates the use of antibiotics in all of these situations. Choose the one where antibiotics are not routine:
A. anaerobic soft tissue abscess in a healthy patient
B. oral infection with elevated temperature or swollen lymph node
C. recognized named clinical infection syndrome or lesion type
D. otherwise fragile or patient with multiple co-morbidities
E. soil in a oral wound
A. anaerobic soft tissue abscess in a healthy patient
Guidelines on the prophylatic use of antibiotics in routine dental procedures have changed through the years, resulting in confusion about this. Indicate which of these REMAINS on of the instances where antibiotics are used prior to invasive dental procedures:
A. history of infective endocarditis
B. heart murmur
C. mitral valve prolapse
D. bicuspid valve disease
E. prosthetic joint replacement
A. history of infective endocarditis
T/F B-lactams are simply never an option when it comes to someone indicating they may have had an allergy to penicillin as a child
False
