Antimicrobials and major Phyla/Classes
Abx that inhibit proper synthesis of new cell wall
Beta-lactams (Penicillins, Cephalosporin, Monobactam)
Vancomycin and cycloserine- interfere w/crosslinking
Bacitracin- blocks NAG/NAM secretion from cytoplasm
Isoniazid and ethambutol
Abx that inhibit protein synthesis
Streptomycin- some aminoglycosides alter 30S shape= mRNA misread
Tetracycline- block tRNA docking site (A site)
Chloramphenicol- block peptide bond formation
Lincosamides & Macrolides- bind 50S, block mRNA movement
Abx that inhibit general metabolic pathways
Atovaquone- interfere with ETC of protozoa & fungi
Heavy metals- inactivate enzymes
Niclosamide- disrupt oxida. phos. of ATP in many protozoa & helminths
Amantadine- inhibit viral uncoating in Influenza A
Sulfanilamide- analog of PABA; irreversibly binds enzyme for folic acid synth, which is required for nucleic acid synth
Abx that inhibit nucleic acid synthesis
Nucleoside analogs- acyclovir, AZT, ribavirin - don’t properly base-pair
quinolones/fluoroquinolones- target prok. DNA gyrase
Abx that disrupt cytoplasmic membrane
Amphotericin B- attaches to ergosterol in fungi, forms membrane channels. Human cholesterol=somewhat susceptible. Bacteria=no effect
Azoles & allylamines- inhibit ergosterol synthesis= only target fungi
Polymyxin- target membrane in gram (-), esp. Pseudomonas .
- Toxic to human kidney
Antiviral to prevent viral attachment/entry
Arildone- block Poliovirus attachment
Low G+C Gram (+) bacteria
- Phylum Firmicutes:
- Clostridia: bacilli, obligate anaerobes, endospores, toxins
- Mycoplasma: facultative/obligate anaerobes, no cell walls (pleomorphic), smallest free-living cells
- Bacillus- soil; endospores
- Listeria- milk/meat contaminate;
- Lactobacillus- normal in body; yogurt
- Streptococcus
- Enterococcus
- Staphylococcus
High G+C Gram (+) bacteria
- Phylum Actinobacteria
- Corynebacterium: pleomorphic aerobe/ facultative anaerobe; produce metachromatic granules (PO4 storage)
- Mycobacterium: aerobic rods/filaments; slow growth due to mycolic acid on cell walls/ acid-fast stain
- Actinomycetes: branching filaments (like fungi)
- Actinomyces: in mouth
- Nocardia: degrades pollutants
- Streptomyces: make Abx (erythromycin, tetracycline)
Phylum Proteobacteria: Class Alpha
nitrogen fixers, nitrifying bacteria, can live in vinegar and low nutrient water baths
Pathogens: Rickettsia, Brucella
Phylum Proteobacteria: Class Beta
- Pathogens:
- Neisseria- gonorrhea, meningitis
- Bordetella- Pertussis(whooping cough)
- Burkholderia- moist environments
- Non-pathogens: recycle sulfur into sulfate, waste treatment
Phylum Proteobacteria: Class Gamma
Most diverse class
- Intracellular pathogens:
- Legionella- eat amino acids, in macrophages; Legionnaires Disease
- Coxiella- low pH, in macrophages, Q fever
- Methane oxidizers
- Glycolytic facultative anaerobes (Enterobacteriaceae): Escherichia, Salmonella, Shigella, Yersinia, Vibrio; cause gastroenteritis and plague
- Pseudomonas- UTIs
Phylum Proteobacteria: Class Epsilon
Campylobacter- blood poisoning
Helicobacter- H. pylori, stomach ulcer
Other Gram (-) bacteria
Chlamydias-
- Chlamydia- small cocci, intracellular, cause chlamydia STD and neonatal blindness
Spirochetes- helical, axial filaments
Bacteroides- obligate anaerobe rods, comprise 30% of feces bacteria
- Treponema- Syphilis
- Borrelia- Lyme Disease
- Bacteroids
Protozoa: General Characteristics
- Eukaryotic, unicellular, no cell wall
- all motile but apicomplexa
- require moist environments
- Usually asexual, but some sexual
Parabasala
Protozoa; no mito;
ex: Trichomonas
Diplomonadids
Protozoa; no mito, golgi bodies, or peroxisomes;
ex: Giardia
Euglenozoa
Protozoa
Euglena- phototropic, no cell wall, flagella
Kinetoplastids- have kinetoplast (MRO);
ex: Trypanosoma, Leishmania
Alveolates
Protozoa
Ciliates- chemohetero, 2 nuclei
ex: Paramecium
Apicomplexans- chemohetero pathogens;
ex: Plasmodium, Toxoplasma
Fungi, Division Zygomycota
saprobes & obligate parasites
ex: Microsporidia, Nosema
Fungi, Division Ascomycota
Molds and yeasts. Food, Abx, pathogens
Ex: Tuber (truffles), Penicillium, Saccharomyces, Histoplasma
Fungi, Division Basidiomycota
Mushrooms and yeasts.
Ex: edible mushrooms, Cryptococcus neoformans (fungal meningitis)
Important Virus Families
- Herpesviridae: dsDNA
- Papillomaviridae: dsDNA
- Picornaviridae: ssRNA(+)
- Rhinovirus, Hep A, Polio
- Coronaviridae: ssRNA(+)
- SARS, cold
- Retroviridae: ssRNA(+) segmented
- HIV
- Rhabdoviridae: ssRNA(-)
- Rabies
- Filoviridae: ssRNA(-)
- Ebola
- Marburg (hemorrhagic fever)