Chlamydia

Ans:A.)Inhibit phagolysosome fusion

Chlamydia are gram negative, non motile, obligate intracellular parasites which multiply in the cytoplasm of host cells.

Chlamydia trachomatis serotypes A, B and C cause trachoma, L1-3 serotypes cause lymphoganuloma venerum, D-K serotypes cause genital tract infection and conjunctivitis.

Pscittacosis is caused by Chlamydia psittaci. 

Ans. is ‘a’ i.e., Chlamydia; ‘b’ i.e., Rickettsia; ‘c’ i.e., Mycoplasma

Bacteria

. Bacteria are single celled microorganisms which can exist either as independent (free living) organisms or as parasites (dependent on other organisms for life).

.   There are typically 40 million bacterial cells in a gram of soil and 1 million bacterial cells in a millilitre of fresh water; in all, there are approximately five nonillion (5 X IV ) bacteria on earth.

Ans. is ‘a’ i.e., Virus; ‘b’ i.e., Chlamydia; ‘c’i.e., Rickettsia

Ans. is ‘c’ i.e., They can grow in cell free culture media 

Unique properties of chlamvdiae are

.  Chlamydia is an obligate intracellular parasite. This means they can survive only by establishig residence inside animal cells

• They need their host’s ATP as an energy source for their own cellular activity. They are energy parasites using a cell membrane transport system that uses ATP from the host system and gives out ADP.

.     This obligate intracellular existence makes it impossible to culture these organisms on nonliving artificial media. Due to their small size and failure to grow in cell – free media they were considered to be viruses.

.    Chlamydiae grows in cultures of a variety of eukaryotic cell lines Mc Coy or HeLa cells. It may be necessary to treat cells with polyanionic compounds such as DEAD-dextran to reduce the electrostatic barrier to infection. Antimetabolite such as cycloheximide is added to favour competition for host cell amino acid pools. All types of chlamydiae proliferate in embryonated eggs particulary in the yolk sac.

.  The special features in structure and chemical composition of chlamydiae are:

– The outer cell wall resembles the cell wall of gram negative bacteria

–         It has a relatively high lipid content

–         It is rigid but it does not contain typical bacterial peptidoglycan; perhaps it contain a tetrapeptide linked matrix.

–         N Acetylmuramic acid also appears to be absent from chlamydiae cell wall.

.         Antibiotic susceptibility of chlamydiae:

–        Penicillin binding proteins occur in chlamydiae cell wall and chlamydiae cell wall formation is inhibited by penicillins and other drugs that inhibit transpeptidation of bacterial peptidoglycan. But remember the important point about t/t, that cell wall inhibitors result in the production of morphologically defective forms but are not effective in clinical disease.

.    Inhibitors of protein synthesis (tetracyclines, erythromycins) are effective in most clinical infections. Erythromycin or tetracyclines are considered the drug of choice for chlamydiae infections.

Ans. is ‘b’ i.e., Chlamydia 

.  Chlamydia produces basophilic (intracytoplasmic) inclusion bodies in infected cells in contrast to eosinophilic inclusion bodies produced by most viruses and hence they are sometimes referred to as Basophilic viruses.

Ans. is ‘d’ i.e., Parotitis 

Ans. is ‘a’ i.e., Q fever 

Ans. is ‘a’ i.e., Corononary heart disease; ‘b’ i.e., LGV; ‘c’ i.e., Ophthalmia Neonatorum

.  “Epidemiological studies have demonstrated an association between serologic evidence of C. pneumoniae infection and atherosclerotic disease of the coronary and other arteries.”  

.  “Occasiaonal patients develop endocarditis and C. psittaci infection should be considered in cases of culture-negative endocarditis.”  

.   Pneumonia caused by C. pneumoniae resembles the primary atypical pneumonia of M. pneumoniae.

.  C. trachomatis types D to K can cause ophthalmia neonatorum.

.  C. trachomatis (type LI; L2, L3) causes L.G.V.

Ans. is ‘d’ i.e., Bacteria 

Chlamydiae are obligate intracellular bacterial parasites of humans, animals and birds.

Ans. is `a’ i.e., Elementary body 

Ans. is ‘c’ i.e., Contains inclusion body

Chlamydia produces basophilic (intracytoplasmic) inclusion bodies in infected cells in contrast to eosinophilic inclusion bodies produced by most viruses and hence they are sometimes referred to as Basophilic viruses.

Unique properties of chlamydiae are

• Chlamydia is an obligate intracellular parasite. This means they can survive only by establishig residence inside animal cells
• They need their host’s ATP as an energy source for their own cellular activity. They are energy parasites using a cell membrane transport system that uses ATP from the host system and gives out ADP.
• This obligate intracellular existence makes it impossible to culture these organisms on nonliving artificial media. Due to their small size and failure to grow in cell – free media they were considered to be viruses.
• Chlamydiae grows in cultures of a variety of eukaryotic cell lines Mc Coy or HeLa cells. It may be necessary to treat cells with polyanionic compounds such as DEAD-dextran to reduce the electrostatic barrier to infection. Antimetabolite such as cycloheximide is added to favour competition for host cell amino acid pools. All types of chlamydiae proliferate in embryonated eggs particulary in the yolk sac.
• The special features in structure and chemical composition of chlamydiae are:

1. The outer cell wall resembles the cell wall of gram negative bacteria
2. It has a relatively high lipid content
3. It is rigid but it does not contain typical bacterial peptidoglycan; perhaps it contain a tetrapeptide linked matrix.
4. N Acetylmuramic acid also appears to be absent from chlamydiae cell wall.

Ans. is ‘b’ i.e., HeLa cells for isolation

Chlamydia is an obligate intracellular parasite. This means they can survive only by establishig residence inside animal cells.

• They need their host’s ATP as an energy source for their own cellular activity. They are energy parasites using a cell membrane transport system that uses ATP from the host system and gives out ADP.
• This obligate intracellular existence makes it impossible to culture these organisms on nonliving artificial media. Due to their small size and failure to grow in cell – free media they were considered to be viruses.

• Chlamydiae grows in cultures of a variety of eukaryotic cell lines Mc Coy or HeLa cells. It may be necessary to treat cells with polyanionic compounds such as DEAD-dextran to reduce the electrostatic barrier to infection. Antimetabolite such as cycloheximide is added to favour competition for host cell amino acid pools. All types of chlamydiae proliferate in embryonated eggs particulary in the yolk sac.
• The special features in structure and chemical composition of chlamydiae are :

1. The outer cell wall resembles the cell wall of gram negative bacteria
2. It has a relatively high lipid content
3. It is rigid but it does not contain typical bacterial peptidoglycan; perhaps it contain a tetrapeptide linked matrix.
4. N Acetylmuramic acid also appears to be absent from chlamydiae cell wall.

Antibiotic susceptibility of chlamydiae:

• Penicillin binding proteins occur in chlamydiae cell wall and chlamydiae cell wall formation is inhibited by penicillins and other drugs that inhibit transpeptidation of bacterial peptidoglycan. But remember the important point about t/t, that cell wall inhibitors result in the production of morphologically defective forms but are not effective in clinical disease.
• Inhibitors of protein synthesis (tetracyclines, erythromycins) are effective in most clinical infections. Erythromycin or tetracyclines are considered the drug of choice for chlamydiae infections.