mock question paper for neet pg, usmle, plab and fmge (mci screening exam) on mycoplasma

Q:1 Granulomatous inflammatory reaction is caused by all of the following organisms,EXCEPT:

A: M. TuberculosisB: M. LepraeC: Yersinia pestisD: Mycoplasma

Correct Ans:D

ExplanationMycoplasma pneumoniae produce acute self limited lower respiratory tract infectionwhich mostly affects children, and young adults. pneumonia caused by Mycoplasmashows patchy consolidation of the lung. The alveoli shows interstitial process withreactive alveolar lining cells and mononuclear infiltration. It does not causegranulomatous inflammatory reaction. A granuloma is defined as a nodular lesion caused by the accumulation of mononuclearleukocytes resulting from a chronic inflammatory reaction. Mycobacteria inducedtuberculosis and leprosy are examples of infectious agent induced granulomatousdisease. Ref: Essentials of Rubin's Pathology edited by Emanuel Rubin, page 174.

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Q:2Which of the following microorganism has sterol in the cell wall?

A: MycoplasmaB: VirusC: FungiD: Protozoa

Correct Ans:A

ExplanationThe mycoplasmas are cell walllacking bacteria that do not synthesize the precursorsof peptidoglycan. A unique characteristic is that some genera require cholesterol forgrowth; unesterified cholesterol is a unique component of the membranes of both sterolrequiring and non–sterolrequiring species if present in the medium. Ref: Brooks G.F. (2013). Chapter 3. Classification of Bacteria. In G.F. Brooks (Ed),Jawetz, Melnick, & Adelberg's Medical Microbiology, 26e.


Q:3Which of the following is the most common pathogens responsible for nosocomial

pneumonias in the ICU?

A: Gram positive bacteriaB: Gram negative bacteriaC: MycoplasmaD: Virus infections

Correct Ans:B

Explanation

Most common organisms causing nosocomial pneumonia are gram negative bacteriain 5070% cases, which reach the lower airways by aspiration of gastric contents or bymicroaspiration of upper airway secretions. Most common organism is pseudomonasaeruginosa followed by enterobacteriacea. Staphylococci aureus is second to gramnegative bacteria and accounts for 15 30%. Anaerobic bacteria is found in 1030%cases.

Ref: Infectious Diseases By Sherwood L. Gorbach, 3rd Edition, Page 477


Q:4 Penicillin would be LEAST effective in treating:

A: SyphilisB: Streptococcal pharyngitisC: Pneumococcal pneumoniaD: Mycoplasma pneumonia

Correct Ans:D

Explanation

Mycoplasma organisms do have a cell wall and are therefore resistant to penicillin.Other forms of bacteria that lack a cell wall are spheroplasts and protoplasts, which areformed from gramnegative and grampositive bacteria, respectively, through theaction of penicillin or by other procedures that remove the cell wall or interfere withits formation. The other organisms listed in the question are all susceptible to theaction of penicillin. Tetracyclines, erythromycin and the aminoglycosides are effectiveantibiotics for the treatment of mycoplasmal infections.

Ref: Infection and Immunity By Huw Davies, D. H. Davies, Page 34


Q:5Which of the following mycoplasmas has been implicated as a cause ofnongonococcal urethritis (NGU)?

A: Mycoplasma hominis

B: M.pneumoniaeC: M.fermentansD: Ureaplasma urealyticum

Correct Ans:D

Explanation

Ureaplasma urealyticum has been associated with nongonococcal urethritis (NGU) aswell as infertility. Mycoplasma pneumoniae is the etiologic agent of primary atypicalpneumonia. M. hominis, although isolated from up to 30% of patients with NGU, hasyet to be implicated as a cause of that disease. M. fermentans has on rare occasionsbeen isolated from the oropharynx and genital tract. M. mycoides causes bovinepleuropneumonia.

Note:Ureaplasmas can be distinguished from mycoplasmas by their ability to produce theenzyme urease, which degrades urea to ammonia and carbon dioxide. Ref: Brooks G.F., Carroll K.C., Butel J.S., Morse S.A., Mietzneron T.A. (2010).Chapter 25. Mycoplasmas & Cell WallDefective Bacteria. In G.F. Brooks, K.C.Carroll, J.S. Butel, S.A. Morse, T.A. Mietzneron (Eds), Jawetz, Melnick, & Adelberg'sMedical Microbiology, 25e.


Q:6 TRUE about mycoplasma are all, EXCEPT:

A: They are L formsB: Sterol enhances growthC: Can grow in cell free mediaD: When grown in liquid medium do not produces turbidity

Correct Ans:A

Explanation

The organisms have diameters of about 0.2 to 0.3 mm, but they are highly plastic andpleomorphic and may appear as coccoid bodies, filaments, and large multinucleoidforms. They do not have a cell wall and are bounded only by a single triplelayeredmembrane, which, unlike bacteria, contains sterols. The sterols are not synthesized bythe organism, but are acquired as essential components from the medium or tissue inwhich the organism is growing. Lacking a cell wall, Mycoplasma and Ureaplasmastain poorly or not at all with the usual bacterial stains. Hemadsorption is a feature ofM pneumoniae. Because of their small size mycoplasma usually do not produceturbidity in liquid media.

Ref: Ray C.G., Ryan K.J. (2010). Chapter 38. Mycoplasma and Ureaplasma. In C.G.Ray, K.J. Ryan (Eds), Sherris Medical Microbiology, 5e.


Q:7 The following is lure for Mycoplasmas except:

A: Multiply by binary fissionB: Are sensitive to betalactam group of drugsC: Can grow in cell free mediaD: Require sterols for their growth

Correct Ans:B

ExplanationGENERAL CHARACTERISTICS OF MYCOPLASMAS:

Very small(0.20.3 µm) .Can pass through bacterial filters.Lack a rigid cell wall.Bound by a single trilaminar cell membrane that contains a sterol.Extremely pleomorphic varying in shape from coccoid to filamentous to otherbizzare forms.Mycoplasma, Ureaplasma, Spiroplasma and Anaeroplasma cannot synthesizetheir own cholesterol and require it as a growth factor in culture medium.Acholeplasma synthesizes carotenol as a substitute for cholesterol, but willincorporate cholesterol if it is provided.Insensitive to cellwall active antibiotics such as penicillins and cephalosporins.Limited biosynthetic capabilities due to a small genome.Multiply by binary fission. However, cytoplasmic division may lag behindgenome division. This results in the formation of multinucleate filaments andother shapes.Do not possess flagellae or pili, but some mycoplasmas including M.pneumoniae, exhibit gliding motility on liquidcovered surfaces. This isattributed to specialized tip structures that also help the organisms in theattachment to the cell.Non sporingStain poorly with Grams stain. Can be stained with Giemsa and Dienes methods.Are considered as stable L forms by some researchers but this hypothesis is stillnot fully accepted.Aerobes and facultative anaerobes except Anaeroplasma which is strictlyanaerobic.For primary isolation, an atmosphere of 95% Nitrogen and 5% Carbon dioxideis preferred.They can grow within a temperature range of 2241°C, the parasitic speciesgrowing optimally at 3537°C.For fermentative organisms, the initial pH of the medium is adjusted to 7.37.8,for arginine metabolizing organisms it should be around 7 and for ureaplasmas,range of pH should be 66.5.PPLO broth/agar and SP4 media are used for isolation of mycoplasmas.Fried egg colony morphology is obtained on culture media.

Ref : Textbook of Microbiology by Dr. D.R. Arora; 3rd edition & Mackie McCartneyPractical Medical Microbiology; 14th edition


Q:8Which among the following is known as ‘Eaton agent’ which causes respiratoryinfection?

A: CorynebacteriumB: PseudomonasC: MycoplasmaD: Streptococcus

Correct Ans:C

ExplanationM. pneumoniae pneumonia is also referred to as Eaton agent pneumonia (theorganism having first been isolated in the early 1940s by Monroe Eaton), primaryatypical pneumonia, and "walking" pneumonia. A mild tracheobronchitis with fever, cough, headache, and malaise is the mostcommon syndrome associated with acute M pneumoniae infection. The pneumonia istypically less severe than other bacterial pneumonias. It has been described as"walking" pneumonia because most cases do not require hospitalization. Ref: Hardy R.D. (2012). Chapter 175. Infections Due to Mycoplasmas. In D.L. Longo,A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison'sPrinciples of Internal Medicine, 18e.


Q:9Mycoplasma pneumoniae (Eaton agent) is an infectious agent that:

A: Lacks steroids in its cytoplasmic membraneB: Contains muramic acid in its cell wallC: Contains only DNAD: Causes primary atypical pneumonia

Correct Ans:D

ExplanationMycoplasma pneumoniae is the causative agent of primary atypical pneumonia, whichwas initially described by Eaton, giving rise to the eponym Eaton agent. Mycoplasmapneumoniae requires sterols for growth, usually in the form of cholesterol that isincorporated into the cell membrane. Mycoplasma pneumoniae lacks muramic acid inits cell wall as do all microorganisms belonging to genus Mycoplasma.

Similarly, and in harmony with other species of the genus, Mycoplasma pneumoniaecontains both DNA and RNA. Mycoplasma pneumoniae is completely resistant toPenicillin, which inhibits cell wall synthesis, because Mycoplasma pneumoniae doesnot have a cell wall. Mycoplasma may cause a hemolytic anemia (cold agglutination).

Ref: Ray C.G., Ryan K.J. (2010). Chapter 38. Mycoplasma and Ureaplasma. In C.G.Ray, K.J. Ryan (Eds), Sherris Medical Microbiology, 5e.


Q:10 'Stalactite' growth is a feature of the following organism:

A: HaemophilusB: PasteurellaC: CorynebacteriumD: Mycoplasma

Correct Ans:B

Explanation'Stalactite' growth is a feature of Pasteurella pestis. If Pasteurella pestis (Yersinia pestis) grown in a flask or broth with oil or ghee(clarified butter) floated on top (ghee broth) a characteristic growth occurs whichhangs down into the broth from the surface, resembling stalactites (stalactite growth). Ref: Textbook of Microbiology By Ananthanarayan And Paniker, 6th edition, Page299.


Q:11

A 24 year old female has fever, malaise, and a dry, nonproductive cough. Shealso complains of headache, muscle aches, and leg pain. Lab values aresignificant for elevated cold agglutinins. Which of the following microorganismsis responsible for her symptoms?

A: Haemophilus influenzaeB: Klebsiella pneumoniaeC: Legionella pneumophilaD: Mycoplasma pneumoniae

Correct Ans:D

ExplanationMycoplasma pneumoniae is a wallless bacterium that causes interstitial pneumonia inyoung adults. Elevated cold agglutinins (a classic clue) are found in about half of thepatients. The cold agglutinins are IgM antibodies. M. pneumoniae may be diagnosedby sputum or complement fixation. Haemophilus causes bronchopneumonia in babies and children, and may occur indebilitated adults. Klebsiella causes a bronchopneumonia with patchy infiltrates involving one or morelobes. Think red currant jelly sputum. It frequently occurs in debilitated patients,

diabetics, and alcoholics. Note that these organisms are highly encapsulated andproduce mucoid colonies on lab media. Legionella lives in contaminated water sources such as air conditioning systems. Ref: Ray C.G., Ryan K.J. (2010). Chapter 38. Mycoplasma and Ureaplasma. In C.G.Ray, K.J. Ryan (Eds), Sherris Medical Microbiology, 5e.


Q:12

A 14 year old girl with cystic fibrosis is admitted to the hospital with fever andshortness of breath, and is diagnosed with pneumonia. During a respiratorytherapy session, she coughs up mucus that is distinctly greenish in color. Whichof the following organisms should be suspected?

A: Klebsiella pneumoniaeB: Mycoplasma pneumoniaeC: Pneumocystis cariniiD: Pseudomonas aeruginosa

Correct Ans:D

ExplanationThe clues suggesting infection with Pseudomonas aeruginosa are the greentingedsputum (due to the formation of blue and green pigments by P. aeruginosa), and theassociation with cystic fibrosis. Unfortunately, P. aeruginosa is very difficult to treatwith most antibiotics, and presents a very difficult therapeutic challenge in themanagement of cystic fibrosis patients.Klebsiella pneumoniae is most often seen in alcoholics, the elderly, and diabetics.Mycoplasma pneumoniae is a common cause of communityacquired atypicalpneumonia, and is characterized by a dry, nonproductive cough.Pneumocystis carinii usually causes pneumonia in immunocompromised patients, e.g.,AIDS patients. Ref: Brooks G.F. (2013). Chapter 16. Pseudomonads, Acinetobacters, and UncommonGramNegative Bacteria. In G.F. Brooks (Ed), Jawetz, Melnick, & Adelberg's MedicalMicrobiology, 26e.


Q:13

A 19 year old college student presents to the student health clinic complaining ofweakness, malaise, and a chronic cough. He has a fever of 100 degrees F and adry cough; no sputum can be obtained for laboratory analysis, so a bronchiallavage is performed and the washings are submitted to the laboratory. Thelaboratory reports that the organism is "slowgrowing."Serodiagnosis revealsStrep MG agglutinins in the patient's serum. Which of the following organismsis the most likely cause of this student's illness?

A: Klebsiella pneumoniae

B: Mycoplasma pneumoniaeC: Parainfluenza virusD: Respiratory syncytial virus

Correct Ans:B

ExplanationThe patient has primary atypical pneumonia caused by Mycoplasma pneumoniae. Thisorganism is fastidious and difficult to culture in the laboratory, however serodiagnosiscan be most helpful. Patients typically produce one or two heterophile antibodiesduring the course of the infection; one agglutinates human O+ RBCs in the cold (thecold hemagglutinin) while the other causes the agglutination of a strain ofStreptococcus salivarius termed strain MG (the Strep MG agglutinins). Klebsiella pneumoniae is readily cultured on routine laboratory media andcharacteristically produces pneumonia with blood clots in the sputum (red currantjelly sputum), which may be indicative of pulmonary abscess development. Parainfluenza viruses cause croup, which is characterized by a dry, "barking" cough.It is more of a tracheitis, bronchitis, and bronchiolitis than a pneumonitis. Noheterophile antibodies are produced in these patients. Respiratory syncytial virus causes an atypical pneumonitis in infants. It is usuallydiagnosed by the observation of syncytial masses in respiratory secretions. Coldhemagglutinins and Strep MG agglutinins are absent. Ref: Levinson W. (2012). Chapter 23. Mycoplasmas. In W. Levinson (Ed), Review ofMedical Microbiology & Immunology, 12e.


Q:14 Vincent's angina is caused by :

A: MycoplasmaB: FusiformisC: Microaerophilic streptococciD: Treponema pallidum

Correct Ans:B

ExplanationVincent's angina is an acute pseudomembranous involvement of the pharynx ortonsils.It may start as aseptic necosis secondary to capillary staisis due to poor oralhygeine,local irritation from food impaction,smoking,trauma,stress and endocrine ormetabolic distrubances.The disease is most likely secondary to a combination offusospirochetal organisms(most often fusobacterium nucleatum and treponemavincentii. Ref : Infectious Diseases edited by Sherwood L. Gorbach, John G. Bartlett, Neil R.Blacklo

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Q:15 Kamla, a 30 yrs old lady examined for infertility by hysterosalpingography,reveals 'Beadlike' fallopian tube and clubbing of ampulla. Most likely cause is:

A: GonococcusB: MycoplasmaC: ChlamydiaD: Mycobacterium tuberculosis

Correct Ans:D

Explanation

'Beadlike' fallopian tube and clubbing of ampulla in a case of infertility indicatesprevious infection with Mycobaterium tuberculosis.

Ref: Shaw’s Textbook of Gynaecology, 12th Edition, Page 119 ; Textbook of Gynecology By D C Dutta, 4th Edition, Page 132


Q:16 Life threatening intravascular hemolysis occurs with sepsis due to whichorganism?

A: Clostridium perfringensB: Mycoplasma pneumoniaC: PseudomonaD: Klebsiella

Correct Ans:A

Explanation

Life threatening intravascular hemolysis due to a toxin with lecithinase activity is seenin clostridium perfringens sepsis.

Ref: Harrison's principles of internal medicine, 18th edition, Page 881.


Q:17Which among the following is the drug of choice in Mycoplasma infection?

A: DoxycyclineB: PenicillinC: Ceftriaxone

D: Cotrimoxazole

Correct Ans:A

Explanation

For mycoplasma tetracyclines are the drugs of choice (doxycycline 100 mg 2 times a day for 10 to 14 days). Erythromycin, Azithromycin and Fluroquinolones can also be used.

Tetracyclines are contraindicated in pregnancy, therefore erythromycin or spiramycincan be used.


Q:18 The MOST COMMON causative organism for community acquired pneumonia is:

A: Streptococcus pneumoniaeB: Haemophilus influenzaeC: Mycoplasma pneumoniaeD: Chlamydia pneumoniae

Correct Ans:A

Explanation

Although Streptococcus pneumoniae is most common pathogen causing communityaquoired pneumonia. Data suggest that a virus may be responsible for up to 18% ofcases of CAP that require admission to the hospital.

Ref: Harrison, E18,P2131.


Q:19Which of the following etiological agents corresponds with pyelonephritis?

A: Mycoplasma pneumoniaeB: Mycoplasma hominisC: Ureaplasma urealyticumD: All of the above

Correct Ans:B

Explanation

Mycoplasma hominis colonizes lower genitourinary tract of almost 50% healthysexually active adults. It is an opportunist pathogen that can invade uppergenitourinary tract and cause infections. It adheres to the epithelial cells of mucosalsurfaces in urogenital tract and can not be eliminated by mucosal secretion and urine.It is mostly resistant to erythromycin but sensitive to tetracycline and lincomycin.

It is associated with following infections in adults:

PyelonephritisSalpingitisPelvic inflammatory diseasePostabortal feverPostpartum fever

Ref: Brooks G.F. (2013). Chapter 25. Mycoplasmas and Cell Wall–Defective Bacteria. InG.F. Brooks (Ed), Jawetz, Melnick, & Adelberg's Medical Microbiology, 26e.


Q:20 Fried Egg Colonies are produced by?

A: ChlamydiaB: MycoplasmaC: NiesseriaD: Diphtheria

Correct Ans:B

Explanation

(67) Mycoplasma

REF: Jawetz 24th edition Section III. Bacteriology Chapter 26

Mycoplasma Cultures:

1. The material is inoculated onto special solid media and incubated for 310 days at37°C with 5% CO2 (under microaerophilic conditions), or into special broth andincubated aerobically. One or two transfers of media may be necessary before growthappears that is suitable for microscopic examination by staining orimmunofluorescence. Colonies may have a "Fried Egg" appearance on agar.


Q:21A patient (pigeon handler) presents with interstitial pneumonitis accompanied byheadache, backache, and a dry, hacking cough. A pale, macular rash is also found onthe trunk (Horder's spots). Likely organism is:

A: HistoplasmaB: ChlamydiaeC: MycoplasmaD: Aspergillus

Correct Ans:B

Explanation

Chlamydiae


Q:22 Metachromatic granules are found in

A: DiphtheriaB: MycoplasmaC: StaphylococcusD: All

Correct Ans:A

Explanation

Ans. is 'a' i.e., Diphtheria


Q:23 Lform is seen in

A: RicketsiaB: ChlamydiaC: MycoplasmaD: H. pylori

Correct Ans:C

Explanation

Ans. is 'c' i.e., Mycoplasma

Lforms are seen in several species of bacteria, developing either spontaneoulyor in presence of penicillin or other agents that interfere with cell wall synthesis.Lforms may be unstable in that the morphological abnormality is maintainedonly in the presence of penicillin, orstable, when the aberrant form becomes the permanent feature of the strain andis retained in serial subcultures.Lform resemble mycoplasma and it is possible that mycoplasma represent stableLforms of as yet unidentified parent bacteria.


Q:24 The following statements are true with reference to Mycoplasma except

A: They are the smallest prokaryotic organisms that can grow in cell free culturemediaB: They are obligate intracellular organismsC: They lack a cell wallD: They are resistant to Betalactam drugs

Correct Ans:B

Explanation

Ans. is 'b' i.e., They are obligate intr acellular organisms

Morphology

. Smallest free living organism, are prokaryotes

. Lack cell wall, are bounded by a triple layered unit membrane that contains sterol(therefore mycoplasmas require sterol for growth).

. Their lack of cell wall is associated with cellular pleomorphism and resistance to cellwall active antimicrobial agents, such as penicillins and cephalosporins lactam drugs).

. Multiplication is by binary fission.

. Non sporing

. Do not posses flagella or fimbria.

. Mycoplasma can be cultivated in fluid or solid media (cell free media).

Biochemical reactions

. Mycoplasmas are chemoorganotrophs, the metabolism being mainly fermentative.

. Most species utilize glucose or arginine as the major source of energy.

. Urea is not hydrolyzed, except by ureoplasmas.

. Unique among prokaryotes is the requirment of most mycoplasmas for cholesterol andrelated sterols.

. Mycoplasmas lack the ability to synthesize purine and pyrimidines.


Q:25 Diene's method is used for

A: MycoplasmaB: ChlamydiaeC: Plague

D: Diphtheria

Correct Ans:A

Explanation

Ans. is 'a' i.e., Mycoplasma

Culture

. May be cultivated in fluid or solid media.

. Generally facultative anaerobes, growth being better aerobically. But, sinceorganisms from primary tissue specimens frequently grow under anaerobicconditions, an atmosphere of 95% N2 and 5% CO2 is preferred.

. Grow in heart infusion peptone broth with 2% agar (pH 7.8) (PRL.O. broth) with freshyeast extract and horse serum.

. For enrichement, 30% human ascitic fluid or animal serum (horse, rabbit) areadded to the medium. (Serum acts as a source of cholesteral).

. The colony gives 'fried egg' appearance.

. Colonies are best studied after staining by Dienes method.

. Most mycoplasma colonies are hemolytic (63 hemolysis) due to production ofhydrogen peroxide. Remember

. Dienes phenomenon is used to detect swarming of proteus.


Q:26 In reference to the mycoplasmas, the following are true except

A: They are inhibited by penicillinsB: They can reproduce in cell free mediaC: They have an affinity for mammalian cell membranesD: They can pass through filters of 450 nm pore size

Correct Ans:A

Explanation

Ans. is 'a' i.e., They are inhibited by penicillins

. Their (mycoplasmas) lack of cell wall is associated with cellular pleomorphism andresistance to cell wall active antimicrobial agents, such as penicillins andcephalosporins.

. Because of their plasticity, they can pass through bacterial filters and have oftenbeen mistaken for viruses. The smallest mycoplasmas are 125250 nm in size so they

can easily pass through bacterial filters 450 nm in size. They are free living in nature,self replicating on a laboratory media.

About option 'c'

. Mycoplasmas generally produce surface infections by adhering to the surface of hostcell.

Adherence is necessary for colonization and infection.

Remember

. The genome of mycoplasma genitalium is the smallest known so far.

Mycoplasmas have limited biosynthetic abilities, so that they need a rich growthmedium containing natural animal protein and in most cases a sterolcomponent.


Q:27 True about mycoplasma are all except ?

A: They are L formsB: Sterol enhances growthC: Can grow in cell free mediaD: When grown in liquid medium do not produces turbidity

Correct Ans:A

Explanation

Ans. is 'a' i.e., They are L forms

Features of mvcoplasma

. Mycoplasmas are unique organisms because they have a very small size similar toviruses but unlike viruses, they have an independent existence i.e. they can grow in cellfree media.

Though they can grow in cell free media but they have a limited biosyntheticability to they need a rich growth medium containing natural animal protein(usually blood serum) and in most cases a sterol component.

. The sterol component is required because mycoplasma contains sterol in their cellmembrane.

. Mycoplasmas are also unique because they do not have a regular cell wall insteadthey are bound by a cell membrane consisting primarily of sterol.

The absence of the cell wall gives two characteristic properties to mycoplasma

i) The absence of cell wall makes them highly pleomorphic.

ii) Mycoplasmas are completely resistant to penicillin because, they lack the cell wallstructure at which penicillin acts instead they are inhibited by tetracycline orerythromycin.

Mycoplasma and L forms of bacteria (cell wall defective bacteria)

L phase bacteria are cell wall defective bacteria that can replicate serially as nonrigid cells and can produce colonies on solid media.

. L forms develop when many bacteria either spontaneously or induced by certaincell wall inhibiting drugs lose part or all of their cell wall and develop into L forms.

Some L phase variants are stable, others are unstable and revert to theirbacterial parental forms.It has been suggested that mycoplasmas may represent stable L forms ofbacteria but genetic, antigenic and biochemical evidence are against thepossibility.

. The characteristic of the cell wall defective forms may be similar to those ofmycoplasma but by definition, mycoplasmas do not revert to parental bacterial forms ororiginate from them. There is no genetic relationship between mvcoplasmas and cell walldefective microbial forms or their parent bacteria.

About option `d'

Mycoplasma and ureoplasma ureolyticum do not produce turbidity in liquid medum.— www.springerlink.com


Q:28 Mycoplasma pneumonia is characterised by all except?

A: Diagnosed by serum cold antibodyB: Treatment is erythromycinC: Cannot be cultured from sputumD: Raised ESR

Correct Ans:C

Explanation

Ans. is 'c' i.e., Can not be cultured from sputum

. Laboratory diagnosis of mycoplasmal primary atypical pneumonia may be establishedeither by isolation of the mycoplasma or by serological methods.

. Mycoplasma can be cultured in fluid or solid media. A widely used isolation mediumis PPLO broth.

. Specimens are :

1. Throat swabs 3. Inflammatory exudates

2. Sputum 4. Respiratory secretions

Treatment of Mycoplasma pneumonia

About other options

. In a patient with a compatible clinical picture, a cold agglutinin titre of 1 : 32 supportsthe diagnosis of mycoplasma pneumonia.

. Cold agglutinins are nonspecific but develop within the first 7 to 10 days.

. The test can also be performed at the bedside.

. ESR, may be raised in 50% of the patients.


Q:29 Which one of the following bacteria contains mycolic acid in the cell wall?

A: EscherichiaB: MycoplasmaC: MycobacteriaD: Staphylococcus

Correct Ans:C

Explanation

Ans. is 'c' i.e., Mycobacteria


Q:30 Mycoplasma infection simulates?

A: Pneumococcal pneumoniaB: Viral pneumoniaC: Hypersensitivity pneumoniaD: Aspiration pneumonia

Correct Ans:B

Explanation

Ans. is 'b' i.e., Viral pneumonia

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mock question paper for neet pg, usmle, plab and fmge (mci screening exam) on mycoplasma

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