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Schuffner dots
- Morphologic changes that occur in host erythrocytes infected with PLASMODIUM VIVAX (western hemisphere) or OVALE (Africa) malaria.
Catch-scratch fever
- Caused by BORTONELLA HENSELAE

-
GRAM-NEGATIVE RODS

SYMPTOMS

- low-grade FEVER

- H/As

- PAINFUL regional LYMPHADENOPATHY 

- Lymph biopsy shows GRANULOMAS FILLED WITH NECROTIC DEBRIS.

TREATMENT

- AZYTHROMYCIN

- DOXYCYCLINE
Epidermic (LOUSE-BORNE) TYPHUS
- Caused by RICKETTSIA PROWAZEKII

-
Transmitted by BODY LICE

SYMPTOMS

- Fever, rash

- Progresses from TRUNK TO EXTREMITIES.

- NO GRANULOMAS
Ixodes scapularis transmits the following:
- BORRELIA BURGDORFERI: Agent responsible for LYME disease.

- BABESIA MICROTI: Agent responsible for BABESIOSIS. (recognized by 1-WEEK INCUBATION PERIOD, and INTRAERYTHROCYTIC PARASITES).

- EHRLICHIA PHAGOCYTOPHILA: Agent responsible for GRANULOCYTICC EHRLICHIOSIS.
Cell wall of Gram(+)
Inside-out

- INNER (CYTOPLASMIC) MEMBRANE

- PEPTIDOGLYCAN LAYER

- CAPSULE

mnemonic: Gram(+) In Pre-Calc.
Cell Wall of Gram(-)
Inside-out

- INNER (cytoplasmic) MEMBRANE

- PERIPLASM (where beta-lactamases live)

- PEPTIDOGLYCAN

- PERIPLASM

- OUTER MEMBRANE (Endotoxin/LPS)

- Capsule
How to the following enzymes help bacteria?

- CATALASE

- COAGULASE

- UREASE
- CATALASE: Allows bacteria to degrade H2O2, which is secreted by macrophages to kill bacteria.

- COAGULASE: Coagulase interacts with prothrombin in the blood forming STAPHYLOTHROMBIN, which allows for the conversion of FIBRINOGEN → FIBRIN. Bacteria that have this enzyme can encapsulate themselves inside a fibrin clot, thus making themselves more resistant to phagocytosis.

- UREASE: Enzyme that breaks down UREA → C2O and Ammonia, the latter of which is used to buffer surrounding acid thus protecting bacteria.
Antibiotics that bind to bacterial 30S subunit of ribosome
AMINOGLYCOSIDES (initiation)

- usually considered CIDAL but can be STATIC against some organisms

- mycin: Streptomycin

- micin: Gentamicin

TETRACYCLINE (tRNA)

- STATIC

- Tetracycline, Oxytetracycline, Doxycycline

Antibiotics that bind to bacterial 50S subunit of ribosome
AMPLENICOLS (peptidyl transferance)

- STATIC

- Chloramphenicol

MACROLIDES

- STATIC

-  Azithromycin, Clarithromycin, Erythromycin

LINCOSAMIDES

- STATIC

- Clindamycin
Antibiotics that bind inhibit cell wall formation:

Glycopeptides
- inhibit PG chain elongation

- CIDAL

- Vancomycin
Antibiotics that bind inhibit cell wall formation:

B-lactams
- Inhibit PBP cross-links

- CIDAL

PENICILLINS

- EXTENDED:

• Amoxicillin, Ampicillin

• Piperacillin

- NARROW:

• B-lactamase sensitive: Penicillin G, Penicillin V 
 
• B-lactamase resistant: Nafcillin, Oxacillin, Dicloxacillin, Flucloxacillin

CEPHALOSPORIN

- 3rd GEN: Ceftriaxone, Ceftazidime (anti-pseufomonal).

B-LACTAMASE INHIBITORS

- Tazobactam, Sulbactam, Clavulanic Acid

COMBOS

- Piperacillin/Tazobactam, Ampicillin/Sulbactam, Amoxicillin/Clavulanic Acid, Ampicillin/Flucloxacillin

OTHER

- Daptomycin (disrupts several different aspects of cell membrane function)
Antibiotics that bind to Topoisomerase II at ligase domain leaving nucluese domains intacts:

Fluoroquinolones
- CIDALS

- 2nd GEN: Ciprofloxacin

- 3rd GEN: Levofloxacin
Antibiotic that is particularly toxic to bacterial cell
- CIDAL

- METRONIDAZOLE
Antibiotic that interferes with bacterial folic acid cycle: Dihydropteroate Synthetase, and DHFR
- CIDAL

- Trimethoprin / Sulfamethoxazole (co-trimoxazole
- Gram(+)

- Coccus (clusters)

- Catalase(+)

- Coagulase(+)

- Mannitol(F)
- STAPHYLOCOCCUS AUREUS

PATHO

- ABSCESSES and CAVITARY LESIONS

- IMPETIGO (Yellow, crusted, weepy papules)

- SSSS

- OSTEOMYELITIS

- FOOD POISONING

- ACUTE  BACTERIAL ENDOCARDITIS (IV drugs)

- TSST-1 → TOXIC SHOCK SYNDROME

► FEVER/NAUSEA/DIARRHEA

► DIFFUSE ERYTHEMATOUS RASH w/ DESQUAMATION OVER THE HANDS and FEET

► TSS is historically a/w USE OF TAMPONS in YOUNG WOMEN

- MRSA: Methicillin-resistant due to altered PENICILLIN-BINDING protein granted by the MEC operon.

TREAT

- Beta-lactamase-resistant b-lactam antibiotics s/a:
methicillin, (not used much anymore), NAFCILLIN, OXACILLIN, DICLOXACILLIN, FLUCLOXACILLIN. 

- For MRSA treat with:

► CLINDAMYCIN (binds 50S ribosomal subunit)

► TMP-SMX: DHFR and dihydropteroate synthetase inhibitors respectively
- Gram(+)

- Coccus (clusters)

- Catalase(+)

- Coagulase(-)

- Novobiocin(R)
- STAPHYLOCOCCUS SAPROPHYTICUS

PATHO

- Common cause of UTI

TREAT

- If methicillin(S) treat with NAFCILLIN or OXACILLIN

- If methicillin(R) treat with VANCOMYCIN (glycopeptide that INHIBITS CELL WALL synthesis in gram(+) )
- Gram(+)

- Coccus (clusters)

- Catalase(+)

- Coagulase(-)

- Novobiocin(S)
- STAPHYLOCOCCUS EPIDERMITIS

PATHO

- SUBACUTE ENDOCARDITIS in patients with prosthetic valves. 

- INFECTIONS of CATHETERS (due to BIOFILM formation)

TREAT

- If methicillin(S) treat with NAFCILLIN or OXACILLIN

- If methicillin(R) treat with VANCOMYCIN
- Gram(+)

- Coccus (chains)

- Catalase(-) 

- Alpha-hemolytic (Green on blood agar, partial hemolysis)

- Optochin(R), Bile(Insoluble;grows), Capsule(-)
- STREPTOCOCCUS VIRIDANS (e.g. MUTANS, SANGUIS)

PATHO

- SUBACUTE BACTERIAL ENDOCARDITIS (in patients with damaged valves after DENTAL work, due to Strep. MUTANS) or Strep. SANGUIS.

TREAT

- ENDOCARDITIS: PENICILLIN G, and maybe combination with GENTAMICIN (aminoglycoside a/b, used mainly against Gram(-). Binds 30S subunit of ribosome)
- Gram(+)

- Coccus (chains)

- Catalase(-) 

- Alpha-hemolytic (Green on blood agar, partial hemolysis)

- Optochin(S), Bile(Soluble;does not grow), Capsule(+)
- STREPTOCOCCUS PNEUMONIAE

PATHO

Most common cause of M O P S

- MENINGITIS in INFANTS, YOUNG-CHILDREN, and ADULTS

- OTITIS media  in CHILDREN

- PNEUMONIA

- SINUSITIS

TREAT

SYSTEMIC/PNEUMONIA:

- PENICILLIN or CEPHALOSPORIN

- S. Pneumo may under TRANSFORMATION and acquire PBP mutations, which lead to PENICILLIN-resistance

MENINGITIS

- VANCOMYCIN

- Gram(+)

- Coccus (chains)

- Catalase(-) 

- Beta-hemolytic (Clear on blood agar, complete hemolysis)

- Bacitracin(R)
- GROUP B STREP (e.g. Strep. AGALACTIAE)

- CAMP test used to identify

PATHO

- PNEUMONIA, MENINGITIS, SEPSIS in BABIES

B for Babies!!

- Screen pregnant women at 35-37 weeks, if positive prophylax with PENICILLIN.

TREAT

- PENICILLIN G
- Gram(+)

- Coccus (chains)

- Catalase(-) 

- Beta-hemolytic (Clear on blood agar, complete hemolysis)

- Bacitracin(S)
GROUP A STREP (e.g. Strep. PYOGENES)

PATHO

- PYOGENIC:

► Pharyngitis

► Cellulitis

► Impetigo (yellow, crusted, weepy vesicles; #1 cause is Staph),

► Erysipelas (Erythematous patches; Staph may also cause it)

- TOXIGENIC:

Scarlet Fever:

► Sore thoat

► Bright red tongue (STRAWBERRY tongue)

► Forchheimer SPOTS (RED SPOTS ON SOFT PALATE)

► "Sandpaper-like" RASH (CIRCUMORAL PALLOR; BLANCHES; STARTS ON CHEST, ARMPITS AND BEHIND EARS; WORSE IN THE SKIN FOLDS

Toxic shock-like syndrome.

- IMMUNOLOGIC: Rheumatic Fever, Acute Gromeluronephitis

mnemonic: No RHEUM for SPECCulations
(Subcutaneous plaques, Polyarthritis, Erythema marginatum, Chorea [sydenham], Carditis [PAN])

TREAT

-  In children treat/w PENICILLIN G {+} CLINDAMYCIN

- ADULTS treat/w B-LACTAM {+} CLINDAMYCIN
- Gram(+)

- Coccus (chains)

- Catalase(-) 

- Gamma-hemolytic (Red on blood agar, no hemolysis)
1) ENTEROCOCCUS (growth in bile, and 6.5% NaCl) (e.g. E. Faecalis)

- Normal COLONIC flora

- Penicillin G RESISTANT

PATHO

- E. FAECALIS and FAECIUM are normal GUT flora → UTI

- E. Faecium → SBE a/w GENITOURINARY procedures

- VRE important cause of NOSOCOMIAL infxn 

2) NONENTEROCOCCUS (growth in bile, NOT 6.5% NaCl) (e.g. S. BOVIS)

PATHO

- Strep. Bovis → SBE a/w COLON CANCER

TREAT

ENDOCARDITIS:

- PENICILLIN

- CEFTRIAXONE (BROAD spect; 3rd gen CEPHALOSPORIN, which are also members of the B-lactam a/b family)

- VANCOMYCIN 

BACTEREMIA: CEFTRIAXONE
- Gram(+)

- Bacilli (aka rods)
1) CLOSTRIDIUM (anaerobe):

PATHO

- C. TETANI → TETANOSPASMIN → TETANUS (inhibits GABA and GLYCINE release in spinal cord.

- C. BOTULINUM → BOTULINUM Toxin → BOTULIMUN (inhibits Ach release at NMJ)

► NOTE: BABIES < 6 mo can become infected by injesting BOTULINUM SPORES. Adults are immune to spore injestion, and require injestion of PREFORMED TOXIN to become infected

- C. PERFRINGENS → ALPHA Toxin → MYONECROSIS (gas gangrene)

- C. DIFFICILE → inflammatory, yellow-tan pseudomembranes in the colon → PSEUDOMEMBRANOUS colitis

Toxin A & Toxin B → A binds to brush border of GUT atracting GRANULOCYTES & B destroys enterocytes.
Often a result of ANTIBIOTIC USE s/a AMPICILLIN and CLINDAMYCIN
Diagnose by detecting TOXINS in stool.

TREAT

- C. botulinum: ANTITOXIN

- C. Tetani: ANTITOXIN + VACCINE booster + DIAZEPAM

- C. Difficile: Oral METRONIDAZOLE (Toxic to anaerobic bacteria and protozoa)

2) LISTERIA

PATHO

- Acquired by injestion of UNPASTEURIZED MILK/CHEESE and DELI MEATS.

- Transmitted VAGINALLY during BIRTH

- Causes AMNIONITIS, SEPTICEMIA, AND SPONTANEOUS ABORTION IN preg. women

- GRANULOMATOSIS INFANTISEPTICA, NEONATAL NENINGITIS in NEONATES

- MENINGITIS in IMMUNOcompromised. 

- MILD GASTROENTERITIS in HEALTHY ADULTS.

TREAT

- Ampicillin in infants but usually self-limited

3) BACILLUS (aerobe)

- Bacillus is Boxcar-shaped

PATHO

- B. ANTHRACIS → ANTHRAX Toxin → ANTHRAX

- CUTANEOUS Anthrax (trans. contact) → black ESCHAR surrounded by edema. Caused by LETHAL factor and EDEMA factor

► May → bacteremia and death.

- PULMONARY Anthrax (inhalation of spores) → FLU-LIKE symptoms → FEVER, PULMONARY HEMORRHAGE, MEDIASTINITIS, SHOCK

► Woolsorter's disease: Inhalation of SPORES from contaminated WOOL

TREAT

- CIPROFLOXACIN

- DOXYCYCLINE

- PENICILLIN

4) CORYNEBACTERIUM DIPHTHERIAE

PATHO

- Causes DIPHTHERIA via EXOTOXIN encoded by b-prophage, which inhibits protein synthesis by ADP ribosylation of EF-2.

- PSEUDOMEMBRANOUS PHARYNGITIS with LYMPHADENOPATHY.

- Diagnose based on Gram(+) rods with metachromic (BLUE and RED) GRANULES.

- TOXOID vaccine prevents it.

ABCDEFG

A DP ribosylation from
B eta-prophage by
C orynebacterium
D iphtheria leads to inhibition of 
E F-2 and has metachromic
G ranules 

HISTO/DIAG

- ELEK test (looking for lines of precipitation due to the presence of diphteria antitoxin Abs)

TREAT

- ANTITOXIN + ERYTHROMYCIN + PENICILLIN G
- Acid-fast Gram(+)

NOTE: the gram(+) classification is from an empirical standpoint only as they actually do not retain the crystal-violet stain very well, but they also do not have an outer-membrane.

- Bacillus
MYCOBACTERIUM Tuberculosis

- Contain mycolic acid in their cell walls. High lipid content.

PATHO

PRIMARY infection in NONIMMUNE

- Focal caseating necrosis in SUBPLEURAL area of LOWER LOBE (GHON Focus)

- HILAR nodes

OPTIONS

1) Heal by fibrosis and calcification → Immunity and hypersensitivity → PPD(+)

- GHON complex = GHON focus + HILAR nodes

2) Progressive lung disease (e.g. HIV, malnutrition) → death

3) Severe bacteremia → MILIARY TB → death

4) Preallergic lymphatic or hematogenous dissemination → DORMANT tubercle bacilli in several organs → REACTIVATION in adult life

REACTIVATION

- Reactivation → secondary TB in lungs (reinfection after partial immunity can lead to this to) = FIBROCASEOUS CAVITARY LESION (usually UPPER lobes)

EXTRApulmonary TB:

- CNS (parenchimal tuberculoma or MENINGITIS; usually on MENINGIS at BASE of BRAIN)

- Cervical Lymph nodes

- Kidney (organ most commly involved)

- Vertebral body (POTT'S DISEASE)

Also known as Tuberculosis SPONDYLITIS

TB spreads to vertebras, most common LOWER THORACIC and UPPER LUMBAR. When two adjacent vertebras are involved INTERVERTEBRAL DISK loses nutrient and dies through CASEATING NECROSIS

DIAG

- PPD: Composed of tuberculin (an OUTER SURFACE PROTEIN) and MYCOLIC ACIDS of TB. Elicits a Type IV HYPERSENSITIVITY RXN.

TREAT

RIPE

- RIFAMPIN (inhibits bacterial DNA-dependent RNA synthesis by RNA polymerase)

- ISONIAZID (INH): Prodrug, when metabolized by microbe INHIBITS MYCOLIC ACID SYNTHESIS.

- PYRAZINAMIDE: Prodrug, leads to accumulation of pyrazinoic acid.

- ETHAMBUTOL: Disrupts CELL WALL synthesis
- Acid-fast Gram(+) 

NOTE: the gram(+) classification is from an empirical standpoint only as they actually do not retain the crystal-violet stain very well, but they also do not have an outer-membrane.

- Bacillus
MYCOBACTERIUM LEPRAE

- HANSEN'S disease (laprae):

- LEPROMATOUS: diffusely over skin; communicable; low cell-mediated immunity with humoral Th2 response.
LEpromatous can be LEthal!!!

- TUBERCULOID: limited to a few hypoesthetic skin plaques; high cell-mediated immunity with a Th1 type immune response.

TREAT

- Long-term DAPSONE (s/e hemolysis and methemoglobinemia [treat w/ methylene blue or ascorbic acid])

- Alternative: RIFAMPIN and DAPSONE/CLOFAZIMINE
- Gram(+)

NOTE: Gram(+) classification is empirical only as they do not have a PEPTIDOGLYCAN CELL WALL and therefore cannot be gram stained. Also, because they lack a cell wall, they are RESISTANT to PENICILLIN-type antibiotics)

- Pseudococcoidal body

- EATON-AGAR(+)
- MYCOPLASMA PNEUMONIAE

PATHO

- ATYPICAL "WALKING" PNEUMONIA (insidious onset, headache, nonproductive cough, diffuse interstitial infiltrate).

- HIGH-TITER COLD AGGLUTININS (IgM) → AIHA.

TREAT

- AZYTHROMYCIN: MACROLIDE, binds 50S subunit of RIBOSOME

- Doxycicline

- Erythromycin
- Gram(+)

- Rods → Branching filaments 

- Anaerobe (not Acid Fast)
- ACTINOMYCES

PATHO

- YELLOW "SULFUR" GRANULES

CLINICAL

- LUMPY JAW (i.e. oral/facial abscesses that may drain through SINUS TRACT)

- Infections a/w IUDs

TREAT

S ulfa for
N ocardia;
A ctinomyces use
P enicillin
- Gram(+)

- Rods → Branching filaments

- Aerobe (Acid Fast)
- NOCARDIA

PATHO

- PULMONARY INFECTION IN IMMUNOCOMPROMISED.

TREAT

S ulfa for
N ocardia (TMP-SMX);
A ctinomyces use
P enicillin
- Gram(-)

- Coccus

- Maltose(F)

Distinguish from Moraxella using OXIDASE test (Neisseria Oxidase(-), Moraxella Oxidase(+) )
- NEISSERIA MENINGITIDIS (ferments both Maltose and Glucose)

- YES polysaccharide CAPSULE

- 12 subtypes, type B MOST COMMON IN US (NO VACCINE FOR IT).

PATHO

-  MENINGOCOCCEMIA and MENINGITIS

- WATERHOUSE-FRIDERICSEN SYNDROME (bleeding into the adrenals due to fulminant infection)

PROPHYLAX

- Rifampin (bacteriocidal, inhibits DNA dependent RNA polymerase)

- Ciprofloxacin (broad spectrum antibiotic, 2nd gen fluoroquinolone, inhibits DNA gyrase, and some topoisomerase inhibing DNA division)

• Ceftriaxone (3rd gen cephalosporin [B-lactam antibiotic → ↓ cell wall synthesis]) in CLOSE contacts.

TREAT

• Ceftriaxone

• Penicillin G (GOLD standard penicillin, administered only IV as it's unstable in stomach acid. [btw, penicillin V is oral penicillin])
- Gram(-)

- Coccus

- Maltose(NF)

Distinguish from Moraxella using OXIDASE test (Neisseria Oxidase(-), Moraxella Oxidase(+) )  
- NEISSERIA GONORRHOEAE (ferments only Glucose)

- NO polysaccharide CAPSULE

- NO VACCINE because it expresses OVER 1 MILLION VARIANTS OF PILLI

- SEXUAL xmsn

PATHO

- Primary Infection:

► URETHRITIS

► CERVICITIS

► PID → FITZ-HUGH-CURTIS syndrome

- PETECHIAL RASH

- SEPTIC ARTHRITIS and TENOSINOVITIS

- NEONATAL CONJUCTIVITIS (NO PNEUMONIA)

TREAT

- CEFTRIAXONE
- Gram(-)

- "Coccoid" rods
1) HAEMOPHILUS INFLUENZA

PATHO

- COMMON CAUSE of BRONCHITIS in SMOKERS

haEMOPhilis

- E piglotitis ("cherry-red" in children)

- M eningitis

- O titis media

- P neumonia

CULTURE 

► Chocolate agar with factors V and X.

► Factors V and X are released from RBCs in chocolate either by GENTLE HEATING or by coculture with STAPH. AUREUS (B-hemolytic).

► The latter is called SATELLITE PHENOMENON

PROPHYLAX

- VACCINE: Type B capsular polysaccharide + diphteria toxoid given 2-18 months of age.

- meningitis with RIFAMPIN for close contacts

TREAT

- meningitis with Ceftriaxone 

2) BORDETELLA PERTUSSIS

- WHOOPING COUGH

- Pertussis TOXIN → inactivation of Gi → ↑ activity of adenylate cyclase → ↑cAMP, which leads to

► ↓ PHAGOCYTOSIS of organism

► ↑ INSULIN release → HYPOGLYCEMIA

TREAT

- ERYTHROMYCIN if early, supportive if late. DO NOT GIVE COUGH SUPPRESSANTS!!!

3) PASTEURELLA

- Animal bites

4) BRUCELLA

think of RANCHERS, VETS, CATTLE

- a/w CATTLE  

- Brucellosis

PATHO

- Chronic GRANULOMATOUS disease w/ CASEATING GRANULOMAS

- ENDOCARDITIS of AORTIC, MITRAL valves

OTHER COCCOID RODS THAT DO NOT GRAM STAIN WELL

1) LEGIONELLA PNEUMOPHILA

- Silver stain

- BCYE agar with IRON and CYSTEINE

PATHO

1. LEGIONNAIRES' disease:

- HIGH fever w/ relative BRADYCARDIA

- H/A and confusion

- Watery DIARRHEA

- HYPONATREMIA

- UNILATERAL infiltrate → CONSOLIDATION

HISTO

- Sputum Gram stain shows many PMNs, but few or no organisms

2. PONTIAC fever: mild FLULIKE syndrome 

- Detected in URINE

- XMSN: Aerosol from environment → human; no human→human

TREAT

- ERYTHROMYCIN 

2) YERSINIA ENTEROCOLITICA

- PET FECES, PORK, MILK

- outbreaks of DIARRHEA in daycares

PATHO

- MESENTERIC ADENITIS, mimis Crohn's or APENDICITIS

3) FRANCISELLA Tularensis

- TURALEMIA

- Most cases in MISSOURI, ARKANSAS, & OKLAHOMA

- Dermacentor TICK, or animal CARCASSES s/a RABBITS, SQUIRRELS, BEAVERS, MURKRATS, DEER.

- 3-5 DAYS INCUBATION

- Intracellular pathogen so → Type IV HYPERSENSITIVITY RXN

PATHO

- Ruptured pustule → ULCERATION

- Fever/Chills/Sweats/Wt. Loss/Non-productive cough

- Granulomas

- H/A

- Joint STIFFNESS, MYALGIAS

- SOB

- May complicated into BACTEREMIA, SPLENOMEGALY, RASH, PNEUMONIA, or ENDOTOXEMIC SHOCK.

TREAT

- STREPTOMYCIN

- TETRACYCLINE
- Gram(-) 

- Comma-shaped

- Oxidase(+) 

- Grows in 42oC
CAMPYLOBACTER JEJUNI

- CHICKEN, MEAT, UNPASTEURIZED MILK.

- Common antecedent event to GUILLAIN-BARRE

PATHO

- MAJOR CAUSE OF BLOODY DIARRHEA, sp. in CHILDREN
- Gram(-) 

- Comma-shaped

- Oxidase(+) 

- Grows in Alkaline Media
- VIBRIO CHOLERAE

PATHO

- RICE-WATER diarrhea

TREAT

- PROMPT REHYDRATON!!!!

- TETRACYCLINE to reduce the duration of illness.

- Gram(-)

- Rods

- Lactose(F)

- Fast-fermenter

- Oxidase(-)
1) KLEBSIELLA

PATHO

- Intestinal flora, when aspirated can cause LOBAR PNEUMONIA, most commonly in

► ALCOHOLICS

► DIABETICS

► Patients with COPD

- RED CURRANT JELLY SPUTUM

- FOUR A'S: Aspiration pneumonic, Abscess in lungs and liver, Alcoholics, di-A-betics.

TREAT

- Antipseudomonal beta-lactam (i.e. ceftazidime, piperacillin/tazobactam) + antipseudomonal quinolone (ciprofloxacin, levefloxacin), or aminoglycoside (i.e. streptomycin, gentomicin)

2) ESCHERICHIA COLI

VIRULENCE factors:

- fimbrae (P-PILLI): CYSTITIS & PYELONEPHRITIS

- K capsule: PNEUMONIA, neonatal MENINGITIS

- LPS endotoxin: SEPTIC SHOCK

PATHO

EHEC

- EnteroHemorrhagic

- 0157:H7 most common

- SHIGA-LIKE Toxin → HUS

- DYSENTERY (due to necrosis and inflammation).

- Distinguished from other E. Coli because it DOES NOT FERMENT SORBITOL.

TREAT

- Primarily supportive. BE CAREFUL WITH A/B THERAPY, specially FLUOROQUINOLONES (e.g. CIPROFLOXACIN) which can induce SLT production and realease increasing the risk for HUS in patients).

ETEC

- EnteroToxigenic

- LT and ST toxins

- No inflammation or invasion.

- Traveler's diarrhea.

EIEC

- EnteroInvasive.

- NO TOXIN but causes NECROSIS and INFLAMMATION of INTESTINAL MUCOSA → DYSENTERY-like DIARRHEA. 

- Clinical manifest. similar to SHIGELLA.

- Invasive

- Dysentery.

UPEC

- MOST COMMON cause of UTI

- P-Pili important virulance factor

- Can progress to BACTEREMIA → SEPTIC SHOCK and ARDS

- Treat empirically AMPICILLIN & GENTAMICIN. In complicated you can use IV CEFTRIAXONE.

EPEC

- EnteroPathogenic

- NO TOXIN, but ADHERES tightly to COLONIC MUCOSA and disrupts MICROVILLI.

- VILLOUS ATROPHY, MUCOSAL THINNING, & INFLAMMATION in the LAMINA PROPIA → DIARRHEA & IMPAIRED absorption

3) Enterobacter

- Gram(-)

- Rods

- Lactose(F)

- Slow-fermenter

- Oxidase(-)
1) Citrobacter

2) Serratia
- Gram(-)

- Rods

- Lactose(NF)

- Oxidase(+)

Cytochrome C Oxidase allows bacteria to use oxygen for energy production with an electron xfer chain.
1) PSEUDOMONAS aureginosa

- WATER source

- BLUE-GREEN pigment and FRUITY (grape) ODOR on culture.

PATHO

- Associated with BURN victims.

mnemonic: PSEUDDO HOT

- P neumonia (specially in CYSTIC FIBROSIS)

- S epsis

- E xternal otitis (swimmer's ear; a/w ELDERLY and DIABETICS)

- U TI

- D rug use

- D iabetic O steomyelitis

- HOT-tub FOLLICULITIS 

- EXOTOXIN A (inactivates EF-2)

- ECTHYMA GANGRENOSUM: Classical skin lesion of pseudomonas septcemia. BLACK, NECROTIC CENTER and a RAISED HOMORRHAGIC RING outside.

TREAT

- Aminoglycoside (e.g. STREPTOMYCIN) + extended-spectrum penicillin (e.g. PIPERACILLIN/taxobactam).

- Antipseudomonal beta-lactam(i.e. ceftazidime, piperacillin/tazobactam) + antipseudomonal quinolone (ciprofloxacin, levefloxacin), or aminoglycoside (i.e. streptomycin, gentomycin)


2) H. PYLORI

PATHO

- GASTRITIS and up to 90% of DUODENAL ULCERS → GASTRIC ADENOCARCINOMA and LYMPHOMA.

TREAT

- Triple therapy:

• Protom Pump Inhibitor (e.g. OMEPRAZOLE, LANSOPRAZOLE)

• CLARITHROMYCIN (MACROLIDE acts by inhibiting protein synthesis by binding tothe 50S subunit of ribosome. BACTERIOSTATIC)

• AMOXICILLIN (bacteriolytic B-lactam)

NOTE: Amoxicillin can be replaced by METRONIDAZOLE, but only in individuals that are allercig to penicillins
- Gram(-)

- Rods

- Lactose(NF)

- Oxidase(-)
1) SHIGELLA 

PATHO

- SHIGA Toxin → CYTOKINE release → HUS

- HIGHLY VIRULENT (10 organisms for infection)

- INVADE INTESTINAL MUCOSA → BLOODY DIARRHEA

- Propel inside cell via ACTIN polymeration, NO FLAGELLA

- Antibiotics SHORTEN illness.

2) SALMONELLA

- MEAT, CHICKEN & EGGS

- H2S(+)

- INVADE INTESTINAL MUCOSA → BLOODY DIARRHEA

- HAS FLAGELLA so can disseminate HEMATOGENOUSLY (SALMON swim)

- Antibiotics may PROLONG excretion of organism in recovered patients (BMJ, 1965:2)

3) SALMONELLA TYPHI

PATHO

- TYPHOID FEVER: ROSE spots in ABDOMEN, fever, h/a, and DIARRHEA. 

3) PROTEUS

- H2S(+)

- UTIs
DO NOT GRAM STAIN WELL

T hese
R ascals
M ay
M icroscopically
L ack
C olor
- Treponema (e.g. Treponema pallidum [syphilis]. It is too thin to visualize. Use DARKFIELD microscopy and IHC)

- Rickettsia (intracellular parasite)

- Mycobacteria (high-lipid-content cell wall, requires acid-fast stain)

- Mycoplasma (no cell wall)

- Legionella pneumophila (primarily intracellular. Use SILVER stain)

- Chlamydia (intracellular parasite; lacks muramic acid in cell wall; use GIEMSA stain)
GIEMSA stain:

Try Pla Ce Bo
It is specific for the phosphate groups of DNA and where there are high amounts of A-T bonding

Human = PURPLE; bacteria = PINK

- Tryponasomes (e.g. Cruzi [CHAGAS]; parasite; reduviid bug]

- Plasmodium (e.g. falciparum [MALARIA]; protozoan parasite; Anopheles mosquito) 

- Chlamidia (e.g. trachomatis [CHLAMYDIA]; obligate intracellular parasite)

- Borrelia (e.g. Burgdorferi [Lyme]; spiroquete; Ixodes Scapularis)

PATHO of Lyme disease

- Stage 1: ERYTHEMO MIGRANS, flulike symptoms

- Stage 2: neurologic (BELL'S PALSY) and cardiac (AV NODAL BLOCK) manifestations.

- Stage 3: chronic MONOARTHRITIS and MIGRATORY POLYARTHRITIS.
PAS stain: 

PASs the sugar
- Identify Whipple's disease (Tropheryma whipplei)

- Presents primarily as MALABSORPTION, WEIGHT LOSS, ARTHRALGIA or ARTHRITIS, DIARRHEA, skin RASH, FEVER, and ADENOPATHY
ZIEHL-NEELSEN
ACID-FAST organisms (Mycobacterium TUBERCULOSIS)
INDIA INK stain:
- CRYPTOCOCCUS NEOFORMANS

Cause of LUNG INFECTIONS, in immunodepressed fungal meningitis  and encephalitis. 

TREAT with FLUCONAZOLE  if no CNS (imidazole antifungal; inhibits the fungal CYP-450 enzyme causing inability to synthesize ergosterol, a componente of fungal cell wall).

If CNS, treat with IV AMPHOTERICIN B (polyene antifungal; binds ERGOSTEROL) and oral FLUCYTOSINE.
SILVER stain:
- LEGIONELLA

- FUNGI (e.g. PNEUMOCYSTIS jiroveci)
Special Culture:

H. INFLUENZAE

mnemonic: when kids have the FLU mom goes to the five (V) and dime (X) store to buy CHOCOLATE.
- CHOCOLATE AGAR with factors V (NAD+) and X (hemain)
Special Culture:

NEISSERIA GONORRHOEAE
NEISSERIA MENINGITIDIS

mnemonic: To connect to Neisseria please use your VPN client.

- VPS (aka thayer-meyer) media.

Vancomycin (inhibits gram(+) organisms

Polymyxin (inhibits gram(-) )

Nystatin (inhibits fungi)
Special Culture:

BORDETELA PERTUSSIS

mnemonic: Bordet for Bordetela
- Bordet-gengou (POTATO) agar.
Special Culture:

CORYNEBACTERIUM DIPHTHERIAE

mnemonic: BLACK ENHANCEMENT of diphtheria is a TELL TELL sign

Step 1) Grow with enhancement medium, LOFFLER'S MEDIUM

Step 2) Culture in TELLURITE agar.

C. DIPHTHERIAE reduces tellurite to metallic tellurium and a BLACK HALO is formed around the colonies.
Special Culture:

MYCOBACTERIUM TUBERCULOSIS

mnemonic: LJ for TB Brown

- LOWENSTEIN-JENSES (aka L J) medium

When grown in L J medium, M. Tuberculosis appears as BROWN GRANULAR colonies.
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