Gram Positive Bugs Flashcards
Staph is grouped how?
clusters/clumps like grapes
Catylase associated with what kind of bacteria?
staph aureas
Strep grouped how?
Bunches in lines or in pairs
Buzz word for Diphtheria?
grey pseudomembrane
Where do we see anthrax?
soil, sheep, goats, cattle
bioterrism
Classifications of Bacteria
Reaction to certain types of stains
Physiologic structure
What are the different types of shapes in bacterial infetions?
5
Bacillus are Rod shaped Coccus is sphere shaped Spirillum are spiral shaped Streptococci are cocci in chains Staphylococci are cocci in clusters
Name the gram positive bacteria we covered?
6
- Staphylococcus sp.
- Streptococcus sp.
- Clostridium Botulinum (anerobe)
- Corynebacterium Diptheriae (Diphtheria)- grey pseudomembrane
- Clostridium Tetanus (Tetanus)
- Bacillus antracis (Anthrax)-soil, sheep, goats, cattle
Stpah aureus is the only staph that produces what?
only one that produced coagulase)-produces exotoxins
Name three things the exotoxins in staph aureus cause?
- food poisening(GI)
- scalded skin syndrome(causes skin to slough off
- toxic shock syndrome- pinpoint rash on ab
What instances should we worry about Staph aureus infection?
4
foley/catheter iv line infections prothetic valves knee replacement etc
What is s. saprophyticus associated with?
UTIs
Strep Pyogenes is what kind of strep?
Lancefield antigen?
Hemolytic?
Group A beta-hemolytic strep
Positive
Yes, partially
Streptococcus agalactiae is what kind of Strep?
What is it mainly known to cause?
Lancefield anitgen?
Hemolytic?
Group B
neonatal meningitis in babies
Positive
Yes
Streptococcus pneumoniae (Pneumococcus) is what kind of strep?
What is it mainly known to cause?3
Lancefield anitgen?
Hemolytic?
GP diplococci
In adults:
CAP!! sudden onset shaking chills, rust colored sputum,
In chidlren: OM, sinusistis
NO
NO
Streptococcus viridans is what kind of strep?
What is it mainly known to cause?
3
Where is strep viridans normal flora in your body?
Lancefield anitgen?
Hemolytic?
Alpha hemolytic
Dental infections
Endocarditis (prothetic valve)
Abcesses
GI
NO
Yes, partially (green)
Enterococcus is what kind of strep?
Where does it like to hang out (normal flora)?
What is it resistance to?
Lancefield?
Hemolytic?
(Group D strep)
Bilius areas, gall bladder/liver etc
vanco and amp.
Yes
Yes
Common Bacterial Infections
caused by gram pos bacteria?
3
Skin-first think staph aureus
Soft tissue
Bone
What do localized infections not do that differentiates them from systemic infecitons?
Organism does not spread through the lymphatic system or reach the bloodstream
-infection subsides due to host defenses
Which pathways do bacteria take to become a generalized or systemic infection?
3
via tissues, lymphatic system, bloodstream
Examples of localized infections? 2
Cellulitis
Erysipelas- strep
Potentially lethal infections that were noted?
3
Necrotizing fasciitis (flesh eating disease)
Myonecrosis (gas gangrene or Clostridial myonecrosis)
Pyomyositis (abscess from bacterial infection of skeletal muscles)
What do we need to make sure we do with cellulitis infections?
mark it with a sharpy, treat cellulitis aggressively
Most staphylococcus are harmless and reside where?
skin and mucous membranes
What is Methicillin-resistant Staphylococcus Aureus resistant to?
What does MRSA look like right awa?
beta lactams
Spider bite but it develops and spreads fast to become very dangerous
How do we further divide Staphylococcus bacteria?
2
Further divided into ability to produce coagulase
1. Coagulase positive species (virulence)
Staphylococcus aureus (common nasal flora)
2. Coag Negative species
Staphylococcus epidermidis (universal skin flora)
Pathogenicity of S. aureus
Cutaneous infections?4
Deep infections? 5
Toxin mediated infections? 3
1. Cutaneous infections – Folliculitis (boils) furuncle burns wounds
2. Deep infections – Osteomyelitis, abscesses, pneumonia, endocarditis, septicemia
- Toxin mediated infections –
Staphylococcal scalded skin syndrome (SSSS),
Toxic Shock Syndrome (TSS),
Food poisoning (in 1-8hr, vomiting ,diarrhea, nausea, self limited )
People with massive burns often die of what?
Staph infections
Skin and soft tissue infections most common in what kind of pts?
immunocompetent host
What is the most common cutaneous staph aureus infection?
Abcesses
Other staph aureus skin infections?
4
- Folliculitis
- Mastitis (infection of the breast when nursing)- nights sweats ad high fevers
- Wound Infections
- Infected IV catheter sites
How would we treat mastitis?
treat with antibiotics and excessive nursing have to drain it. wont cause problems with babies
How would we diagnose septic arthritis?
injury to the area/staph. red swollen joint you need to tap and see what you have.
What major systemic infections does Staph aureus cause?
3
Bacteremia/septicemia/endocarditis
Pneumonia
Musculoskeletal: septic arthritis
What type of MRSA is associated with invasive procedures or devices?
What kind of MRSA can begin as a painful skin boil. Spread by skin to skin contact. At risk populations include high school wrestlers, child care workers and people who live in crowded conditions?
HA-MRSA Health care associated
CA-MRSA: Community Associated among healthy people
How do we treat MRSA?
3 drug choices
2 (timeline)
- bactrim/sulfas, then 2. clinda or doxy. then 3. vanco
aggressive and early
How should we treat MRSA of the nares?
Bactroban (Mupirocin) ointment in the nose qd
Full body wash (Rules of 3) is called what?
how often do we use it?
(Hibiclens)
3 times a day for 3 days then 3 times a week for 3 weeks
Features of Cellulitis?
6
Red swollen warm to touch no areas of pus! painful tender
What is the most common bug that causes cellulitis?
How does it manifest?
Group A strep
Follws an nnocuous or unrecognized injury. Inflammation is diffuse spreading along the tissue
When does staph aureus usually cause cellulitis?
2
Usually with a wound or penetrating trauma
Localized ABCESS becomes surrounded by cellulitis
What is the current antibiotic choice for cellulitis?
3
Clindamycin, Doxycycline, or Trimethoprim-Sulfa (“Bactrim, Septra”)
If you have severe cellulitisand its spreading quickly and systemic symptoms- fever what should we go with?
go with IV antibiotics go right to vanco. hospitalize them
Hospital admission criteria for cellulitis?
5
- animal bite on pts face or hand
- area of skin involvement is more than 50% of limb or torso or more than 10% of total body surface
- Coexisitng morbidities
- Compirmised host
- If they need IV ABX
When the tissue in the area of cellulitis turns to pus under the surface of the skin, the collection of pus is termed what?
an abcess
What does an abcess consist of?
2
What is the most common bacteria in the abcess?
The pus in the abscess consists of dead, liquified tissue, billions of white blood cells
“staph”, or Staphylococcus aureus
Many other bacteria that can cause abscesses
Whats the difference between a empyema and an abcess?
Must be distinguished from empyemas which are accumulations of pus in a preexisting rather than a newly formed anatomical cavity.
Clinical features of abcesses?
3
- superficial like on skin, subcutaneous tissues, on the hand
- Infections of the head and neck
- Deep seated infections
Example of abcesses of the head and neck?
suppurative parotitis (acute infection of the parotid)
Example of deep seated infections that cause abcesses?
4
hepatic abscess
splenic abscess
sub-phrenic abscess
rectal abscess
How will the center of the abcess feel?
soft center. feels like fluid underneath
Treatment of Abscesses?
2
- I and D
? ABX- but probably do it anyway.
If the abscess has a lot of cellulitis around it, an antibiotic is probably needed.
Abscesses have to be drained. - Antibiotics cannot penetrate w/o drainage. They do not get into the site without it being drained first
When the bacteria in a cellulitis or abscess start spreading quickly between the fat layer and the muscle underneath it is termed what?
necrotizing fasciitis
Fasciitis means the infection is spreading along the space between the fat and the muscle underneath
How does necrotizing fasciitis kill tissue?
The infection cuts off the blood supply to the tissue above it and the tissue dies
The bacteria may also enter the bloodstream
Treatment of Necrotizing Fasciitis?
3
What are the main bugs associated with it?
4
- Have to cut it out and keep cutting it out until the bacteria stops spreading
- Antibiotics help, but they will NOT cure the infection
- -Antibiotics for a minimum of 3 wks
Empiric antibiotics to cover anaerobes,
gram negative bacilli, streptococci, and
Staph aureus
What is myonecrosis?
What bug causes it?
Whats its incubation period?
Clinical presentation? 4
How should we treat it?
4
(2 drug choices)
gas gangrene
Pure Clostridium perfringens infection
Incubation period of hours to days
Local edema and pain accompanied by fever and tachycardia
- Pen G (3-4 million U q4h) or
- chloramphenicol
- Surgical removal of infected muscle
- Hyperbaric chamber
What is Pyomyositis?
What bug most often causes it?
Treatment? 2
A purulent bacterial infection of the skeletal muscles which results in a pus-filled abscess
Staph aureus
Must be drained surgically and antibiotics are given for a minimum of 3 weeks
Staphylococcal toxin disorders?
4
- Gastroenteritis (Food Poisoning)
- Toxic Shock Syndrome
- (TEN) Toxic Epidermal Necrolysis
- (SSSS) Staph Scalded Skin Syndrome
Describe the progression to (TEN) Toxic Epidermal Necrolysis?
4
What should we treat with if we even suspect this?
- first- multiform erythematous minor. little bullseye region.
- Its major when you get mucosal membrane involvement. treat different. (oral lesions)
- next step is stevens johnsons/blistering
- TEN is massive loss of dermis
Prednisone
What is a disease caused by epidermolytic toxins produced by certain strains of Staphylococci. This toxin is distributed systemically and results in dissolution of keratinocyte attachments in only the upper layer of the epidermis (stratum granulosum).?
What population does this mostly affect?
Staphylococcal scalded skin syndrome
SSSS usually affects newborns and children. Adults are less commonly affected because improved renal function allows for clearance of the toxins from the body, although adults with renal failure are more susceptible
What bug are we most worried about for Nosocomial infections: device/ implant associated infections - shunts, catheters, artificial heart valves / joints, pacemaker?
Staphylococcus epidermidis
How are Streptococcal Infections subdivided and what are the divisions?
3
Subdivided by ability to lyse RBC’s
- beta hemolysis-complete lysis
- alpha hemolysis-partial lysis
- gamma hemolysis-no hemolysis
What three complications can arise from strep throat?
3
- post streptococcal glomerulonephritis
- Rheumatic heart disease
- Scarlet fever
How will strep manifest in kids under 4 compared to older kids?
a lot of kids carry it in their sinuses and ears. so if little brother 3-4 gets sick from sister who has strep throat age 6. They will present different
What is Erysipelas?
What causes it?
Acute streptococcus infection of the upper dermis and superficial lymphatics
Streptococcus pyogenes (Beta hemolytic group A Strep)
How do we differentiate Cellulitis and Erysipelas?
2 differences
Cellulitis has an ill-defined border that merge smoothly with adjacent skin; usually pinkish to reddish
Erysipelas has an elevated and sharply demarcated border with a fiery-red appearance
Management of Cellulitis & Erysipelas:
Local Care?3
Long term care?
2 meds for how long
- Immobilization
- Elevation to reduce swelling
- Draw lines (with the patients permission)
Two weeks of antibiotic therapy
Penicillin and Dicloxacillin for most patients
Superficial lesions that break and form highly contagious crust; often occurs in epidemics in school children; also associated with insect bites, poor hygiene, and crowded living conditions
Impetigo (pyoderma)
Honey crust
What is a pathogen enters through a break in the skin and eventually spreads to the dermis and subcutaneous tissues; can remain superficial or become systemic. Mostly in the face?
Erysipelas
Sharper and red
What are the two kinds of Impetigo?
Non-bullous and Bullous
Whats the cause of Non-bollous impetigo?
What age does it primarily present in?
How does it look?
What is its duration like?
- Strep Group A or Staph aureus
- Preschool and school aged kids
- Very thin walled vescile on an erythematous base. Yellowish thick custs
- transient
What is the cause of bullous impetigo?
What age does it primarily present in?
How does it look?
What is its duration like?
- Staph aureus
- All ages
- Bullae of 1-2 cm. Thin flat brownish crusts
- persist for 2-3 days
Predisposing factors for impetigo?
3
Malnutrition
Diabetes
Immuno-compromised status
Complications that can occur from impetigo?
4
- Streptococcal infection (pink eye, meningitis, endocarditis)
- Scarlet Fever (Scarlatina. Caused by Strep pyogenes (Group A Strep)
Can get “Strawberry tongue) - Urticaria (Hives. Allergic reaction)
- Erythema Multiforme (unknown etiology. Skin condition in the superficial microvasculature of the skin and oral mucous membranes usually follows an infection or drug exposure)
- Streptococcal infection
- Scarlet Fever
- Urticaria
- Erythema Multiforme
Treatment of Impetigo?
2 treatments
4 drug choices
- First soak the affected area in warm water or use wet compresses to help remove overlying scabs
- Antibiotic Creams or ointments
- Bactroban (Mupirocin) AAA tid x 5 days
- Fusidic Acid Cream AAA x 7-12 days
- Retapamulon ointment bid x 5 days
- Consider Septra/Bactrim if has history of MRSA
Streptococcus pyogenes (group A beta hemolytic strep) Common infections? 6
Cutaneous infections Pharyngitis (sore throat) Otitis media Sinusitis Pneumonia Streptococcal Toxic Shock Syndrome
Complications of GABHS infections
2
- Rheumatic fever (RF)-
delayed antibody mediated disease (immune disease)
- Glomerulonephritis
4 signs for pharyngitis and tonsilitis?
strep throat-
- white exudate(in virus and bacteria)
- petechia
- strawberrry tongue,
- red beefy tonsils
Mono- looks the same
Pathogenicity
of Beta Hemolytic group B strep?
2
Neonatal meningitis and sepsis
Pneumonia
Most common menigitis bugs for adults?
H. flu, nessieria meng
Streptococcus pneumoniae (pneumococcus)
Gram positive cocci in pairs. What are some common diseases they cause?
4
What is a core measure associated with this infection?
Does Strep Pneumo have the lansfield antigen?
Pneumonia
Otitis media
Sinusitis
Meningitis
Prevention: Vaccination (capsular antigens)
IMMUNIZATION (core measure)
Pneumovax
NO
What makes strep pneumo so effective against our immune system?
How would we diagnose pneumonia causes by strep pneumo?
4 symtpoms
What would we hear during auscultation?
Polysaccarhide capsule
-we think its one of our own
SHAKING CHILL
HIGH FEVER
RUST COLOR sputum, pleuridic chest pain
dullness/dead spot with consolidation
Why do kids have so many ear iinfections?
esuatachian tube disfuntion. angle is really poor for good drainage so you get them in chidlren
OTITIS MEDIA defintiion?
How is acute otitis media different from otitis media with effusion?
What would otitis with effusion respond best to?
If a child is not talking by two what do we need to ask about in the history?
Most common bug for ear infections?
Presence of a middle ear infection
Acute Otitis Media
Bulging TM thats taught with pressure, Erythmatous, might see Pus
Otitis Media with Effusion: Presence of nonpurulent fluid within the middle ear cavity
drainage (may want to treat with an antibiotic but dont need to)
Are they have lots of ear infections? Might be permanent damage to the ear
Strep pneumo
Major risk factors for acute otitis media are what?
7
Young age Bottle feeding Drinking a bottle in bed Parental history Sibling history Second hand smoke Daycare
Organisms responsible for otitis media are?
7
- Streptococcus pneumoniae
- Haemophilus influenzae
- Moraxella catarrhalis
- Group A Streptococcus
- Staph aureus
- Pseudomonas aeruginosa
- RSV assoc. with Acute Otitis Media
Physical Exam findings for otitis media?
The classic description for Otitis Media is an erythematic, opaque, bulging tympanic membrane with loss of anatomic landmarks including a dull/absent light reflex
Treatment options for OM?
Infants younger than 6 months?
Children 6 mo to 2 years? 2
Children 2 years and older?
- Infants younger than 6 months should receive antibiotics
- Children 6 months to 2 years should receive antibiotics if the diagnosis is certain (acute onset, MEE, and middle ear inflammation)
- –Diagnosis uncertain: Observation period 48 to 72 hours with analgesics and follow up - Children 2 years and older should receive antibiotics if diagnosis is certain or illness severe (severe otolagia and temp > 102)
Observation period an option
First line treatment for OM?
3
Allergic or second line?
Amoxicillin: 20-40 mg/kg/day TID for 10-14 days or
Augmentin: 45 mg/kg/day BID for 10-14 days
Auralgan: analgesic/adjunct for ear pain 2-4 drops TID
Cefzil, Pediazole, Bactrim
Streptococci viridans (alpha or gamma hemolytic) is common where?
What are the infections that it causes?
3
Common oral/pharyngeal flora
Infections
- Endocarditis
- Bacteremia & Septic Shock
- Dental
Group D streptococci (enterococcus)
most common infections that it causes?
5
- UTI
- Endocarditis
- Intraabdominal infections (abscesses)
- Biliary tract Infections!!
- Wound infections
Diagnosis of Streptococcal Infections?
4
Culture
ASO titers/Streptozyme
Rapid Group A Strep tests
Gram Stains
Antistreptolysin O (ASO) titer is a blood test to measure what?
antibodies against streptolysin O, a substance produced by group A Streptococcus bacteria
S. pyogenes: DOC?
PCN (low incidence of resistant organisms)
S. pneumoniae DOC?
Entercoccus DOC?
increased PCN resistance
Erythromycin for both in PCN allergic patient
Ampicillin for enterococcus
What is a Gram positive, nonmotile, spore forming bacterium Bacillus anthracis.
Natural transmission to humans by contact with what?
What makes it so good against our defenses?
2
Anthrax
infected animals or contaminated animal products
- has special capsule that makes it really good at avoiding phagocytosis
- spore is ideal for inhalation
How can anthrax be transmitted?
3
Contact, ingestion, or inhalation of infective spores
Incubation period of anthrax?
Clinical syndromes? 4
Main threat for anthrax?
How does it manifest?
1-7 days (1-60 days)
Cutaneous ulcer,
respiratory,
gastrointestinal, oropharyngeal
Inhalation
Bronchopneumonia not a component (hemorrhagic lymphadenitis and mediastinitis) - so you dont see it coming until symptoms are really bad
What are the two biggest causes of death for anthrax?
Most comomn?
- lyphatic or hematogenous spread leading to menigitis (most common)
- Pulmonary lymphatic bloackage leading to pulmonary edema
Epidemiology of inhalation anthrax?
Sudden appearance of multiple cases of severe flu illness with fulminant course and high mortality
Clinical symtpoms of inhalation anthrax?3
Serious symptoms?
4
- Non-specific prodrome of flu-like symptoms
- Possible brief interim improvement
- Abrupt onset of
- respiratory failure and
- hemodynamic collapse 2-4
days after initial symptoms, possibly accompanied by
- thoracic edema and a
- widened mediastinum on CxR
INHALATION ANTHRAX: DIAGNOstic studies?
2
- Chest radiograph with widened mediastinum
2. Peripheral blood smear with gram (+) bacilli on unspun smear
Microbiology for anthrax diagnosis?
Blood culture growth of large gram (+) bacilli with preliminary identification of Bacillus spp.
Pathology of diagnosis for anthrax?
4
- Hemorrhagic mediastinitis, 2. hemorrhagic thoracic
- lymphadenitis,
- hemorrhagic meningitis
Prophylaxis treatment for anthrax?
Preexposure?
Postexposure?2
Pre-exposure: Vaccine
{not currently available}
Post-exposure: Ciprofloxacin (or other quinolone) or doxycycline (vaccine if available)
Treatment for cutaneous anthrax?
Ciprofloxacin or doxycycline x 60 days
Treatment of anthrax for inhalation?
3 things to remember
Ciprofloxacin or doxycline PLUS
1 or 2 other drugs (e.g., vancomycin, imipenem)
Initial Rx should be IV then switch to PO for total 60 days
Diphtheria infects what part of the body?
What are its most common complications?
2
mucous membrane
Most common complications are myocarditis and neuritis
Symtpoms of Diptheria?
4
sore throat,
malaise,
cervical lymphadenopathy
low grade fever.
Whats the earliest pharyngeal finding in diptheria?
pharyngeal finding is mild erythema, which can progress to isolated spots of gray and white exudate.
Treatmen of diptheria? 2
For severe cases?
How should we monitor?
3
How do we grow out and culture diptheria?
Antibiotics- erythromycin or penicillin G
diphtheria antitoxin for severe cases.
- Careful airway management
- serial electrocardiograms and cardiac enzymes
- Neurologic status should also be monitored carefully
potassium tellurite
skin infections and abcesses. go to bacteria?
How do we treat staph?
Which streps have the lancefiled anitgen?
If pregnant mom has group B strep what should we treat with?
Staph auerus
sulfa then doxy then vance
Group ABD
36 weeks treat with IV antibiotics. (amoxicillin and pen G)
Strep pneumo treat with what?
3
amox, aug, pen g
