Lecture 9 - Wall-less bacteria and Other Oddities

Question 1

Mycoplasma are unique in that they “scavenge” _____ from the host, and substitute this for having a cell wall.

Answer 1

Cholesterol

Question 2

An L Form is a bacterium that has lost its ____ ____, and can divide. This can only occur in ______conditions (otherwise they would lyse without a _____ ____.) Keep in mind these bacteria lose their shape (which should make sense given they’ve lost the thing that holds their shape.)

Answer 2

Cell Wall

Isosmotic

Cell Wall

Question 3

Mycoplasma and Chlamydia are similar in that they are both very _____ (makes them hard to filter.)

Answer 3

Small

Question 4

Mycoplasma are ______ bacteria (don’t invade host cells), while Chlamydia are obligate ______ bacteria (they can survive outside, but can only grow inside.) Keep in mind Chlamydia are considered gram _____, but their cell wall is not comprised of _____.

Answer 4

Extracellular

Intracellular

Negative

Peptidoglycan

Question 5

Mycoplasma Pneumoniae is a causative agent for _____ or “_____” pneumonia. It also causes ______ or ______(the most common M. Pneumoniae disease) and Pharyngitis (which can proceed to the former two, or in rare cases Otitis media or Systemic infection - very rare.)

Answer 5

Atypical

“Walking”

Bronchitis or Bronchiolitis

Question 6

Mycoplasma Genitalium is a causative agent for non-gonococcal ____ in both men and women, but can also cause _____ _____ _____ (PID) in women.

Answer 6

Urethritis

Pelvic Inflammatory Disease

Question 7

Mycoplasma were initially thought to be viruses because they could not be ______ (too small - they are the smallest bacteria.) Because they are so small, they have a small ______, which lacks many genes.

Answer 7

Filtered

Genome

Question 8

The cytoplasmic membrane of Mycoplasma is unique in that it contains ______ that it scavenges from the host and is ______ (the outer leaflet is comprised of Lipo_____ rather than LPS.)

Answer 8

Sterols

Asymmetric

Lipoprotein

Question 9

Because Mycoplasma lack a cell wall, they don’t ____ stain, they are resistant to cell wall inhibitors, and their _____ is not maintained by the cell wall (instead, it’s maintained by a primitive _______.)

Answer 9

Gram

Shape

Cytoskeleton

Question 10

M. Pneumoniae diseases are presumtively diagnosed based on severity and lack of responsiveness to ______, followed by responsiveness to non-Beta lactam antibiotics.

Answer 10

Penicillin

Question 11

Atypical bacterial pneumonia is more characterized by _____ rather than fluid buildup. It can be cause by Mycoplasma and Chlamydia pneumoniae, and in rare cases, Legionella pneumophila (very severe.)

Answer 11

Inflammation

Question 12

In Atypical pneumonia, because it’s more characterized by inflammation than fluid buildup, the accompanying cough is usually ____. The incubation period is about 1-__ weeks. Symptoms also include:

• Rales
• Fever (though it’s often low.)
• X-ray shows diffuse or patchy density (rare to see consolidation.)

Answer 12

Dry

1-3 weeks

Question 13

Atypical pneumonia caused by Mycoplasma usually occurs in individuals ____ than 40 years old. That caused by Chlamydia accounts for 20% of all ____ pneumonia, and even more in children 5-20 years old.

Answer 13

Less than 40

Adult

Question 14

M. Pneumoniae virulence factors include a _______ organelle –> binds specific host receptor protein and ultimately binds cilia which stops them from beating. It also produces _____ _____ which causes direct cytotoxic damage to epithelial cells (the host inflammatory response to this indirectly causes cytolysis as well.)

Answer 14

Cytoadherance organelle

Hydrogen peroxide

Question 15

M. Pneumoniae can be diagnosed through bacterial culture (colonies have characteristic _____ ____ shape), but because the bacteria are slow growing, this isn’t a great method. Serum ______ can be performed, but is only positive about 50-70% of the time.) Diagnosis should be confirmed by staining the sputum with a fluorescent _____, or by ______.

Answer 15

Fried Egg shape

Agglutination

Antibody

PCR

Question 16

Mycoplasma treatments include _____ synthesis inhibitors, as cell wall synthesis inhibitors would have no effect.

Answer 16

Protein

Question 17

Chlamydia sp. are obligate ______ pathogens (they can survive outside but can only grow/divide inside) whose cell wall lacks ______. Instead, the cell wall is comprised of cross-linked ______.

Answer 17

Intracellular

Peptidoglycan

Proteins

Question 18

As obligate intracellular pathogens, Chlamydia sp. have a _____ life cycle. This consists of an ______ body that is non-replicative (but is infectious and can survive short periods outside macrophages), and a ______ body, which is replicative and can ONLY survive inside macrophages.

Answer 18

Biphasic

Elementary body

Reticulate body

Question 19

Chlamydia infection is a common cause for atypical pneumonia in young adults and adults older than ____.

Answer 19

60

Question 20

Keep in mind that Chlamydia sp. lack peptidoglycan in their cell walls, so beta-lactam antibiotics (i.e. penicillin) won’t be effective. Instead, ______ inhibitors should be used to treat. The fact that chlamydia sp. are obligate intracellular bacteria is another reason to use _____ inhibitors, as these tend to be taken up by host cells –> allows them to carry out their function on the intracellular bacteria.

Answer 20

Translation

Translation

Question 21

Chlamyidia trachomatis causes about 50% of non-_______ urehtritis. In females, it can also cause PID, endometriosis, and ectopic _____.

Answer 21

non-Gonococcal urethritis

Pregnancy

Question 22

Because it’s hard to directly identify Chlamydia sp., in order to diagnose C. Trachomatis infection, you should follow a diagnosis of _______ method (rule out other possibilities.) Treatment involves use of ______ synthesis inhibitor.

Answer 22

Exclusion

Protein

Question 23

Chlamydia Psitacci is the causative agent for ______ (bird fever.) It is spread through inhalation of bird _____. Infection can lead to Pneumonia with systemic infection, hepatitis, and ______.

Answer 23

Psittacosis

Feces

Endocarditis

Question 24

Legionella Pneumophila is the causative agent for _______ disease. The bacteria has an incubation period of 2-___ days, and the disease has a high mortality rate (about 15%.)

Answer 24

Legionnaires

2-10 days

Question 25

Legionella Pneumophila is a gram ____, pleiomorphic _____. It’s hard to stain, is often ____, and is a facultative ______ organism. It grows within _____ in the wild, and then in _____ during human infection. Intracellular L. Pneumophila are short rods, and are highly ____.

Answer 25

Negative

Bacillus (rod)

Intracellular

Amoeba

Macrophages

Motlie

Question 26

Like other intracellular bacteria, it is taken up in a ______, and prevents fusion with the ______. If you’re infected, you’re not also contagious. The original source is what causes infection in others.

Answer 26

Phagosome

Lysosome

Question 27

L. Pneumophila grow in amoeba above ____ degrees C, but are killed below _____ degrees C.

Answer 27

25

20

Question 28

The two preferred methods, which should be done together, to identify L. Pneumophila infection are _____ on a special medium and ______ antigen test. In order to treat L. Pneumophila infection, antibiotics that can penetrate/be taken up by ______ should be used (like translation inhibitors - which should make sense, given it infects these cells.)

Answer 28

Culture

Urinary

Macrophages