Micro (1) Flashcards
What is the role of peptidoglycan?
Gives rigid support and protects against osmotic pressure. Composed of a sugar backbone with peptide side chains cross linked by transpeptidase
What is the role of the outer membrane in gram negatives?
this is the stie of endotoxin (LPS)
What are the ribosomal subunits for bacteria?
50S and 30S
What bacteria has a capsule (protects against phagocytosis) made of D-glutamate?
Bacillus anthracis
What is the chemical composition of plii/flagella?
glycoproteins
What are the major gram + cocci?
streptococci and staphylococci
What are the major gram - cocci?
Neisseria
Moraxella catarrhalis
What are the major gram + bacilli?
Bacillus
clostridium
Corynebacterium
Gardnerella (gram variable)
Listeria
Mycobacterium (acid fast)
Lactobacillus
What are the major enteric gram - bacilli?
Bacteriodes, Campylobacter. E. Coli
Helicobacter, Proteus, Pseudomonas
Salmonella, Vibrio
Yersinia
Serratia
What are the major respiratory gram - bacilli?
Bordetella
Haemophilus (pleomorphic)
Legionella (silver stain)
hat are the major Zoonotic gram - bacilli?
Bartonella
Brucella
Francisella
Pasteurella
What are the branching filamentous bacteria?
Actinomyces
Nocardia (weakly acid fast)
What are the spirochetes?
Borrelia
Leptospira
Treponema
What bugs do not gram stain well?
Treponema (cell wall too thin to visualize)
Myobacteria (high lipid content, myolic acids in cel wall detected by carbolfuchsin in acid-fast stain)
Mycoplasma (no cell wall)
Legionella pneumophilia (primarily intracellular)
Rickettsia (intracellular parasite)
Chlamydia (lacks classic peptidoglycan because of low muramic acid)
What bugs can be visualized with a Giemsa stain?
Chlaymdia,
Borrelia
Rickettsia
Trypanosomes
Plasmodium
Certain Bugs Really Try my Patience
What bugs can be visualized with a PAS (periodic acid-Schiff) stain?
Stains glycogen, mucopolysaccharides; used to diagnosed Whipple Disease (tropheryma whipplei)
What bugs can be visualized with a Ziehl-Neelsen (carbol fuchsin) stain?
Acid fast bacteria such as Nocardia, Mycobacteria and protozoa such as Cyrptosporidium occysts
Alternative stain for screening Auramine-Rhodamine (cheaper)
What bugs can be visualized with India Ink?
Cyrptococcus neoformans (nucicarmine can also be used to stain thick polysaccharide capsule red)
What bugs can be visualized with a Silver stain?
Fungi (e.g. Pneumocystis), Legionella, Helicobacter pylori
What special media is needed to culture H. influenza?
Chocolate agar with factors V (NAD+) and X (hematin)
What special media is needed to culture N. gonorrhoeae and N. meningitidis?
Thayey-Martin agar with Vanco (inhibits gram + organisms), Trimethoprim, Colistin (inhibits gram- negative organisms except Neisseria), and Nystatin (inhibits Fungi)
What special media is needed to culture B. pertussis?
Bordet-Gengou agar (with potato) or
Regan-Lowe medium (with charcoal, blood, and ABX)
What special media is needed to culture C. diptheriae?
Tellurite agar, Loffler medium
What special media is needed to culture M. tuberculosis?
Lowenstein-Jensen agar




