MICROBIOLOGY- Basic Bacteriology Flashcards
This Bacterial structure gives rigid support, protects againts osmotic pressure
Peptidoglycan
This is the chemichal composition of peptydoglycan
Sugar backbone with peptide side chains
Which is the link between Sugar and peptide in the peptydoglycan?
Cross linked by transpeptidase
What is the difference in the membrane between gram positive and gram negatives?
Gram positive have cell wall/ cell memebrane
Gram negative have Outer membrane
In the gram positives works as the major surface antigen
Cell wall/ Cell membrane
This bacterial structure gives support to the cell membrane in gram positives
Peptudoglycan
This element on the cell wall in gram positives induces TNF and IL-1
Lipotheichoic acid
In Gram negatives this is the site of endotoxin and major surface antigen
Outer membrane
In gram negatives is consider the endotoxin
Lipopolysaccharide (LPS)
In the outer membrane of gram negatives, who induces TNF and IL-1
Lipid A
This chemical compositon plays the role as the antigen in the outer membrane
O polysaccharide is the antigen
Unique to gram positives
Lipoteichoic acid
Unique to gram negatives
Endotoxin/LPS
Which is the function of plasma membrane in the bacterial structure?
Site of oxidative and transport enzymes
Which is the chemical composition of Plasma membrane?
Phospholipid bilayer
This bacterial structure manages the Protein synthesis
Ribosome
Which kind of subunits do the bacterias have?
50S and 30S Subunits
This is a characteristic just for gram negatives which consists of a space between the cytoplasmic membrane and outter membrane
Periplasm
What does the periplasm contains?
Many hydrolytic enzymes including β Lactamase
This Bacterial structure gives protection against phagocytosis
Capsule
Which is the chemical composition of capsule on the bacterial structure?
Polysacaccharide
Which Bacteria is the only exception on the chemical composition of the capsule?
Bacillus anthracis
Why is Bacillus anthracis the only exception on the chemical composition of the capsule?
Because it contains D glutamate instead of polysaccharide
Which importance does Pilus has in the bacteria structure?
Mediate adherence of bacterial to cell surface
What other name does the pilus receives?
Fimbria
Who carries the attachment between 2 bacteria during conjugation?
Sex Pilus
This is the chemical composition of fimbria
Glycoprotein
Who gives the motility to the bacteria?
Flagellum
The flagellum is composed of….
Proteins
This bacterial structure makes the bacteria resistant to dehydration, heat and chemicals
Spore
This bacterial structure gives the bacteria a Keratin like coat
Spore
Chemicaly this are the composition of the spore
Dipicolinic acid; peptidoglycan
Contains a variaty of genes for antibiotic resistance, enzymes and toxins
Plasmid
What is the composition of the plasmid?
DNA
Mediates adherence to surfaces, especially foreign surfaces (indwelling catheters)
Glycocalyx
What is the difference between Glycocalyx and Pilus?
Glycocalyx is made of polysaccharide
Pilus is made of glycoprotein
Which are the types of bacterial morphology?
Circular (coccus) Rod (bacillus) Branching filamentous Pleomorphic Spiral No cell wall
Give examples of circular (coccus) gram positive
Staphylococcus
Streptococcus
In the morphology Neisseria is an example of?
Coccus gram negative
Who are examples of Rod (bacillus) gram positive?
Clostridium Corynebacterium Bacillus Listeria Mycobacterium Gardnerella
This kind of Rod bacteria is consider a gram variable
Gardnerrella
Which is the classification of Bacillus Gram negatives?
Enterics
Respiratory
Zoonotic
Give examples of Rod Gram negatives of the enteric famiy
E. coli Shigella Salmonella Yersinia Klebsiella Proteus Enterobacter Serratia Vibrio Campylobacter Helicobacter Pseudomonas Bacteriods
Which is the bacterial taxonomy of Haemophilus, Legionella and Bordetella?
Bacillus gram negative of the respiratory family
This respiratory Rod bacteria is consider pleomorphic
Haemophilus
Who are consider Zoonotic Bacterias?
Francisella
Brucella
Pasteurella
Bartonella
Which bacterias are consider branching filamentous?
Actinomyces
Nocardia
Rickettsiae and Chlamydiae which morphology do they have?
Pleomorphic
Giemsa stain is used for this bacterias
Rickettsiae
Chlamydiae
Borrelia
These three bacterias are consider Spiral or spirochetes
Borelia
Leptospira
Treponema
Which is the only bacteria that doesn´t has a cell wall?
Mycoplasma
Why doesn´t Mycoplama Gram stains?
Because it doesn´t has cell wall
So… if Mycoplasma doesn´t has a cell wall, what does it has?
Contain sterols
What is so special about mycobacteria cell wall?
Contain mycolic acid. High lipid content
These bacterias do not Gram stain well
Treponema Mycobacterias Mycoplasma Legionella pneumophila Rickettsia Chlamydia
Which is the reason treponema doesn´t Gram stain well?
Too thin to be visualized
What is needed in order to visualized Treponem?
Treponemes-dark field microscopy and fluorescent antibody staining
This bacteria has high lipid content in cell wall, that´s why it doesn´t stain well with Gram
Mycobacteria
So… if it´s difficult for Mycobacteria to be visualized with Gram stain, How do we detect it?
Detected by carbolfuchsin in acid fast stain
Which is the reason Legionella pneumophila has limitation with Gram stain?
Because is Primarily intracellular
This special stain is used for Legionella pneumophila
Silver Stain
These two bacterias are consider intracellular parasites
Rickettsia
Chlamydia
What does Chlamydia lacks in the cell wall?
Lacks muramic acid in cell wall
Name 5 types of stain
Giemsa PAS Ziehl Neelsen India ink Silver stain
These 5 bacterias are stain with Giemsa
Chlamydia, Borrelia, Rickettsiae, Trypanosomes, Plasmodium
What does the PAS stains?
Stains Glycogen, mucopolysaccharides
Which disease is diagnosed with PAS?
Whipple disease (Tropheryma whipplei)
Which is the meaning of PAS?
Periodic acid acid Schiff
Ziehl Neelsen works for these bacterias
Acid fast organisms (Nocardia, Mycobacterium)
Which other name does Ziehl Neelsen receives?
Carbol fuchsin
This bacteria requires India ink because of its thick polysaccharide capsule
Cryptococcus neoformans
What else can be use to stain thick ploysacharide capsules?
mucicarminne stains red
Who can be stain with silver?
Fungi (Pneumocystis), Legionella, Helicobacter pylori
Which media is used in special cultures for H. influenzae?
Chocolate agar with factors V (NAD+) and X (hematin)
Thayer Martin (or VPN) is the media culture for this bacteria
Neisseria Gonorrhoeae
Neisseria Meningitidis
Which characteristics does VPN media has?
Vancomycin (inhibits gram positives organisms)
Polymyxin (inhibits gram negative organisms except Neisseria)
Nystatin (inhibits fungi)
For Bordetella Pertusis this is the special media culture
Bordet Gengou (potato) agar
Tellurite agar, Loffler medium is special media culture for?
C. diphteriae
In order to make a culture for M. Tuberculosis, what agar is needed?
Lowenstein Jensen agar
For M. pneumoniae which is the media used for isolation and what is the special requirement?
Eaton Agar, requires cholesterol
Pink colonies on MacConkey agar is used for…
Lactose fermenting enterics
Why do the colonies turn pink with MacConkey agar?
Fermentation produces acid, turning colony pink
Apart from MacConkey agar, where else can E. Coli grow?
Eosin Methylene blue (EMB) agar with green metalic sheen
This is the media used for isolating Legionella
Charcoal yeast extract agar buffered with cysteine and iron
If you want to make a special culture for Fungi which agar do yo need?
Saboraud agar
Why do the Obligate aerobes are O2 dependant?
To generate ATP
These are examples of obligate aerobes
Nocardia, Pseudomona aeruginosa and Mycobacterium tuberculosis
If there is a reactivation of M. tuberculosis where is the predilection site of apperance? Why?
Apices of the lung, which have the highest POs
Which cases can be at risk for reactivation of M. Tuberculosis?
After immune compromise or TNF α inhibitor use
In which patients can P. aeruginosa be seen?
Seen in burn wounds, complications of diabetes, nosocomial pneumonia, pneumonias in cystic fibrosis patients
Clostridium, Bacteriodes and Actinomyces on which kind of conditions do they have to live?
Obligate anaerobes
Why do the obligate anaerobes are suceptible to oxidative damage?
They lack catalase and/or superoxide dismutase
Why do the obligate anaerobes generally have foul smell?
Short chain fatty acids
These bacterias are difficult to culture, and also produce gas in tissue
Obligate anaerobes
Which kind of gas do obligate anaerobes produce?
CO2 and H2