Lect. 1 Classifications and Gram positives Flashcards
1
Q
- Identify 3 structural differences in Prokaryotes vs. Eukaryotes
- Name the structure which is found in both Prokaryotes and Eukaryotes but is structurally different allowing for antibiotics to take effect on the prokaryotes
A
- Nucleus w/ a membrane, endoplasmic reticulum, and mitochondria
- Ribosomes (prokaryotes 70s and eukaryotes 80s)
2
Q
- The classification species can be broken down further into subgroups. What how are individuals broken up into serotypes (serovars) and biotypes (biovars)?
A
Serotypes (serovars) are differentiated based upon their antigen.
Biotypes (biovars) are differentiated on the basis of some type of biological difference (e.g. one biotype is capable of infecting a horse while the other is capable of infecting a sheep)
3
Q
- What is DNA homology used for?
- What is 16s rRNA homology used for?
A
- DNA homology is used to determine relationships between CLOSELY closely related bacteria
- 16S rRNA homology is used to determine relationships between DIVERSE groups of bacteria
4
Q
Identify each of the morphology types indicated below in the photo
A
5
Q
- Matrix Assisted Laser Desorption Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF-MS) classifies organisms based on what?
A
- MALDI-TOF-MS measures highly abundant proteins which are found in microorganisms. With this organisms are identified by the characteristic patterns of proteins they show.
6
Q
- Explain the structure of bacteria focusing on information regarding their nuclear material, plasmids.
- What are bacteriophages (phages)?
A
- Nuclear material of bacteria have no limiting membrane as in eukaryotes and are typically attached to the cell membrane during cell division. Plasmids are additional DNA material which are autonomous with the chromosomal DNA (can add or subtract DNA). Plasmids are important in the transfer of antimicrobial resistance, virulence factors, and other DNA material.
- Bacteriophages are viruses which attack bacteria. Can kill or just replicate along with the bacteria. Also able to transfer plasmid like information (e.g antimicrobial resistance, virulence factors)
7
Q
- Identify differences in gram positive cell wall structure vs. gram negative cell wall structure.
- How does one get antibiotics in a pathogen?
A
- Gram (+) bacteria contain a thick peptidoglycan layer and have no outter cell membrane associated with this layer. Where as Gram (-) (see image below)
- In addition gram (+) linkages in the peptidoglycan are quite similar where as gram (-) linkages tend to vary
- In order to get inside a bacteria the antibiotic must follow a transporter with which the bacteria contains
8
Q
- In gram (+) bacteria their peptidoglycan layer can be disrupted in two spots. Where on these chains can this occur?
- Identify where lysozymes attack and destroy
A
- Vulnerable areas on the peptidoglycan of gram positives are the Beta-1,4 linkages of the NAG (N-acetylyglucosamine) and the NAM (N-acetlmuramic acid) and the areas where crossbridging (transpeptidation) occurs in the peptidoglycan layer.
- Lysozymes attack the Beta-1,4 linkages causing destruction of the peptidoglycan –> resulting in bacterial cell wall breakdown.
9
Q
Peptidoglycans of bacteria can have many different effects on the bacteria itself as well as on the host including: antigenic, toxic, and adjuvant effects on the host and increasing the resistance to infectious agents of the bacteria.
- Describe how the peptidoglycan can increase resistance of the host to infectious agents
- Describe the adjuvant effects of Muramyl dipeptide (MDP) on the host
A
- The peptidoglycan can increase resistance to infectious agents by causing activation of B-cells to stimulate M0s to produce IL1. IL1 will then promote thymocyte maturation and IL2 secretion by antigen-sensitive T-cells which will result in the triggering of regulatory T-cells
- Muramyl dipeptide (MDP) causes an increase in body temperature as well as cause for a somnogenic effect (sleepiness)
