Bacteria

Bacteria

1. Aerobes

   • Aerobes
     • Gram
       • GP
         • Cocci (C)
           • Catalase
             • Positive = bubbles (O2) when dipped in H2O2
             • Cat +
               • Coagulase
                 • Positive result = clumping of plasma
                 • Coag + (clumping)
                   • Streptococcus Aureus
                     • - Post surgical infections - cellulitis - nosocomial pneumonia  - IV infections  - bacteremia  - food poisoning
                     • B-lactamase present
                       • Susceptible to B-Lactamase stable drugs: - Methicilin  - Nafcillin - Cephalosporin 
                       • MRSA
                         • Methicillin resistant.  use Vancomycin
                         • Vancomycin Resistant S. Aureus
                           • Use Linezolid, Ceftaroline 
                     • TX - NAFCILLIN, METHICILLIN, CEPHALOSPORIN
                 • Coag -
                   • Coagulase-neg STAPHYLOcoccus
                     • Generally are opportunistic infections that impact prosthetics.  - IV --> bacteremia  - Shunt --> meningitis  - Valve --> endocarditis
                     • S. Epidermis
                       • Normal skin flora that could contaminate blood samples. Not pathogenic  -MC COAG NEG STREP
                     • S. Saprophyticus
                       • Cause UTI in sexually active females 
             • Cat - (Enterococcus // Streptococcus)
               • B - Hemolysis
                 • GAS: S. Pyrogenies (4)
                   • - Pharyngitis - Soft tissue//skin infections (cellulitis) - Flesh eating bacteria  - toxic shock 
                   • Susceptible to penicillin // cephalosporins
                 • GBS: S. Agalactiae (2)
                   • Can cause UTI in pregnant mom which leads to Neonatal meningitis and sepsis 
               • Alpha Hemolysis
                 • Optochin (P disk)
                   • Susceptible
                     • S. Pneumoniae (pneumococcus) - MC CAP
                       • Tx CAP: Vancomycin // Levofloxacin (Meningitis tx is poor bc BBB)
                   • Resistant
                     • Enterococcus
                       • Opportunistic GI flora that can cause UTI, polymicrobe soft tissue infections, bacteremia 
                       • E. faecalis
                         • More susceptible than E. Faecium  S to Ampicillin & Vancomycin
                         • Ampicillin
                         • Vancomycin
                       • E. Faecium
                         • More difficult to treat
                         • +/- vancomycin
                           • VRE Tx: Linezolid, Ceftaroline
                         • R- Ampicillin
                     • Vidirans Streptococcus (oral flora)
                       • Oral flora causing endocarditis, aspiration pneumonia
                       • S. mutans = cavities
               • Gamma Hemolysis
         • Bacili (R)
           • Bacillis Anthracis
             • Spore. Causes cutaneous & inhalation anthrax. - BLACK ESCHAR spores may be found in goats (their coats) and can cause hematologic meningitis seen in CSF. 
             • BLACK ESCHAR
           • Bacillis Cereus
             • spore grows on rice that has been left out or reheated. Release toxins that are ingested and cause diarrhea & vomiting (food poisoning) . THE BACTERIA IS NOT INGESTED!!
           • Listeria Monocytogenes
             • Common opportunistic infection from SOFT CHEESES OF ANIMALS that may cause bacteremia & meningitis. 
             • SOFT CHEESE
           • Corynebacterium Diphtheriae
             • Causes diphtheria. Pharyngitis w/ grey pseudomembrane in throat.  also cause airway obstruction, myocarditis, CR collapse, CN paralysis  TDAP vaccine is against diphtheria toxin so that even if you get infected with the bacteria, the toxin cannot harm you. 
       • GN
         • Cocci (R)
           • Neisseria Gonorrhoeae
             • STI Males = urethritis Females = cervicitis --> PID, ectopic pregnancy, infertility 
             • Urethritis; UTI --> PID, ectopic preg, infertility
             • Tx: Ceftriaxone [Azithromycin, fluoroquinone, doxycycline]
           • Neisseria Meningitidis
             • Meningitis, sepsis, DIC
             • Tx: penicillin
           • Moraxella Catarrhalis
             • Otitis media, CAP, bronchitis
             • B-Lactamase +
             • Respiratory flora
         • Bacilli (C)
           • Enterobacteriaceae: facultative anaerobe = GI // Female Gu flora
             • Fecal --> oral transmission  - facultative anaerobic - ferment glucose - Cytochrome Oxidase negative - Nitrite positive (UTI)
             • Salmonella, shigella, e. coli, yersinia Enterocoliti
             • E. COLI : MC - CA - UTI
               • 2nd MC = Proteus Mirabilis
           • HACEK Endocarditis
             • H - haemophilis A - acinetobacter C - Capnocytophaga // Cardiobacterium E - Eikenella K - Kingella
           • Misc. Zoonotic
             • Brucella
               • From skinning animals. Causes ulcers that become lymph node bubos.
             • Francisella Tularemia
               • From drinking unpasteurized milk. Causes intracellular macrophage infections. Granuloma & abscess formation
             • Yersinia Pestis
               • Plague  - from person-person = pneumonic - rat-flea-person (bubonic)
           • Misc. Respiratory
             • colonize URS after infection knocks out fibronectin. Allows enterobacteriaceae & klebsiella (nosocomial pneumonia) to colonize.  Abe given in hospital quicken removal of GP flora.
             • H. Influenza
               • Has typable and non-typable strains. Respiratory flora 
               • H. Influenza -B (HiB)
                 • Kids 4 or under.  - Otitis media, epiglottitis, meningitis, bacteremia. -Ab against Type B capsule has reduced incidence.
               • Non-typable (COPD PT)
                 • COPD pt get treatment --> kill normal H. Influenza and replace with more resistant GN bacteria
             • H. Ducryeri (STD)
               • STD that causes PAINFUL, ULCERATIVE CHANCROIDS in men & prostitute 
             • Bordatella Pertusis
               • whooping cough [acute tracheobronchitis] which can cause chronic infection.
           • Misc. GI [not-enterobacteriaceae]
             • Vibrio (curved)
               • V. Cholerae
                 • - unlike B. Cereus, Vibrio Cholerae will colonize the GI track and release toxins that cause RICE WATER DIARRHEA. - from stool in water- from bad seafood (cholera likes warm salt water)
               • V. Vulnificus
                 • from saltwater injury.  cause disseminated skin infections in people with bad livers.
             • Campylobacter
               • Transmitted from farm animals/ pets to humans [little human-human transfer]
             • H. Pylori
               • causes gastritis and peptic ulcers. - has urease that raises pH so that they can thrive.
           • Non-Fermenting
             • Pseudomonas Aeruginosa
               • Cause Nosocomial pneumonia, UTI, skin infections in burn patients -not enterobacteriaceae  - nosocomial infections in pt after Abx - Highly resistant bacteria 
               • Tx: Aminoglycoside, anti-pseudomonal penicillin, 3rd gen cephalospoin (Ceftriaxone), quinolones, CARBAPENAM

2. Obligate Anaerobes

   • GN Bacilli (URS// female genital flora)
     • Lung abscess, PID, Peritonitis
     • Provotella
     • Bacteroides
     • Porphyromonas
   • GP
     • GP bacilli
       • Acinomyces (URS//female genital flora)
         • chronic sinus infection with boring necrosis = LUMPY JAW.  Tx: amputate
       • Clostridium spp.
         • Colon
           • C. Deficile, C. botulinum 
         • Puncture
           • C. Tetanus, C. Myconecrosis
       • Propionibacterium Acnes.
         • causes acne
     • GP Cocci
       • Peptostreptococci (URS)
         • aspiration pneumonia --> Brain // lung abscess

3. Abnormal cell wall

   • all penicillin (b-lactam) resistant
   • Mycobacterium [acid fast]
     • no cell wall (no B-lactams). Cell wall has lots of mycolic acid (acid fast) - have gram stain ghosts
     • M. Tuberculosis
       • - Tuberculosis  - Kidney MC other affected site - Nutritionally deficient/ immunosuppressed - not everyone has clinical presentation and P2P transmission only occurs if person has symptoms 
       • use PPD or TST test
     • MOTT
       • Scrotochromogen - always pig. Photochromogen - pig. after light non-photochromagen - no pig. Rapid - grow fast 
       • (P) M. Kansasii
         • Immunosuppressed chronic respiratory or disseminated infection
       • (N) M. Avian complex
         • Immunosuppressed chronic respiratory or disseminated infection
       • (R) M. Fortuitum
         • Post surgical infections
   • Ureaplasma & Mycoplasma [have no cell wall]
     • Ureaplasma Urealyticum & Mycoplasma Hominis (female genital flora)
       • infections in female genital tract and newborns (like s. agalactiae)
     • Mycoplasma Pneumonia
       • Tx: macrolide, Fluroquinones
   • Chlamydia
     • -cannot make any ATP - obligate intracellular parasite -EB --> RB --> EB --> burst cell -EB is inert -RB can replicate
     • C. Trachoma's (STD)
       • - Urethritis, cervicitis - Cervicitis --> PID, ectopic pregnancy, infertility -Trachoma (blindness) in poor countries
     • C. pneumoniae
       • atypical/walking pneumonia [need PCR, cannot be found on culture] -pneumonia & bronchitis
     • Tx: Azithromycin, Doxycycline, quinolone
   • Rickettsiaceae
     • - Can make ATP outside a host, but not enough. Obligate intracellular parasite
     • R. Rickettsii
       • Rocky Mt. spotted fever
     • Coxiella Burnetti
       • -Q Fever -not transmitted by arthropod
     • Ehrlichosis & Anaplasma
       • - Ehrlichosis (monocytes) - Anaplasma (granulocyte) - HA, fever, no rash - NO TX BY CEPHALOSPORIN -arthropod transmission
       • (R) CEPHALOSPORIN
   • Legionella
     • Clusters of endemic infections by contaminated water source.  -can survive any water temp
     • B-lactam R. Use levofloxacin & azithromycin
   • Treponema Palladium (syphilis)
     • - Painless, hard chancery (unlike H. Ducreyi)  - this lesion might disappear (go to secondary syphilis)
     • Secondary syphilis
       • skin and mucosal secondary syphilis all over the body
       • Tertiary syphilis
         • CV & neurosyphilis
     • Susceptible to B-lactam (except neurosyphilis bc it can't cross BBB)
   • Borrelia Burdorferi
     • Lyme disease from ticks at bite: erythema chronic migraines [targetoid rash] - chronic joint//CNS lesions  -Tx: B-Lactam Abx
   • Spirochete