Old Questions: TU: MSC 2nd Year: Bacteriology: 2061

T.U.2061 BACTERIOLOGY

GROUP A(3*15)

1.      Describe mechanism of drug resistance development.

2.      Define staphylococcus . list toxins and enzymes of staphylococcus aureus. Describe laboratory diagnosis of Staphylococcus aureus.

3.      Define STD. list etiological agent of STD. describe laboratory diagnosis of HIV.
                                                       Or
describe mechanism of cholera toxin to induce secretary diarrhea and laboratory diagnosis of Vibrio cholerae.
                                         GROUP B(7*5)

4.      Describe Kauffman and white scheme classification of salmonella.

5.      Describe principles and uses of PCR.

6.      Describe quality control in microbiology laboratory.

7.      Describe method of rapid diagnosis of bacterial diseases in the laboratory.

8.      Describe laboratory diagnosis of infective bacterial endocarditis.

9.      Describe method of identification of non afermentative gram negative bacilli.

                                           GROUP C(5*4)

10.  Write short notes on any four.

1. Method of determination of MTC of antibiotics.
2. FTA-Abs test.
3. CAMP test
4. EPEC
5. Methods of anerobiosis.

Old Questions: TU: MSC 2nd Year: Bacteriology: 2059

TU 2059 BACTERIOLOGY

GROUP A (3*15)

1. Describe the pathogenesis and laboratory diagnosis of Mycobacterium tuberculosis.
2. What is STD. describe the laboratory diagnostic methods of diagnosis of one of the common STDS in context of Nepal.
3. Describe the principles of antimicrobial susceptibility test by Disc diffusion method
                                           or
   explain the mechanism of action of antibiotics.
   
                                            GROUP B(7*5)
4. Explain corneal ulcer and its laboratory diagnosis.
5. Write in brief on rapid microbiological methods for identification of bacteria.
6. Describe briefly laboratory diagnosis of peptic ulcer.
7. Describe briefly hospital acquired infection and infection control.
8. Define urinary tract infection and explain the main role of bacterial count in its laboratory diagnosis.
9. Explain in briefly the serological test for diagnosis of Typhoid fever.
                                                    GROUP C
10. Write short notes on any four. (5*4)

A.     Bacteriamia or septicaemia

B.     Urease test

C.     VDRL and TPHA

D.     Disinfection

E. Travellers Diarrhoea

Old Questions: TU: MSC 2nd Year: Bacteriology: 2058

TU 2058 BACTERIOLOGY

GROUP A (3*15)

1. Describe the mechanisms of bacterial resistance to antibiotics.
2. Describe in detail rapid and conventional methods to diagnose meningitis.
3. Point out characteristic features of family enterobacteriaceae. Describe Kauffman and white scheme of classification of salmonella. List the media used to isolate salmonella from blood and stool samples.
                                        Or
   describe the laboratory diagnosis of upper respiratory tract infection. List methods of differentiation of Streptococcus pneumoniae from Streptococcus viridans.
   
   GROUP B (7*5)
4. Describe laboratory organization in brief.
5. Describe the rapid methods of diagnosis of infectious disease.
6. Describe molecular mechanism of sectetary diarrhea caused by Vibrio cholerae and its laboratory diagnosis.
7. Describe rapid diagnosis of gas gangrene.
8. Describe enzymes and toxins produced by Helicobacter pylori and its laboratory diagnosis.
9. Describe travellors diarrhea in brief.
   
                                                                GROUP C
10. Write short notes on any four. (5*4)

1. Betalactamame test
2. Montoux test.
3. Urease test
4. MOTT bacilli
5. PID
   
   

Laboratory diagnosis of dengue infection

TU 2063

Laboratory diagnosis of dengue infection

The clinical diagnosis of dengue, both the uncomplicated dengue fever form and DHF(dengue hemorrhagic fever)/DSS( dengue shock syndrome), is often unreliable. Dengue fever may resemble clinically a variety of acute febrile illnesses, although the severe muscle and bone pain is suggestive of dengue.

Similarly, DHF may resemble other causes of haemorrhagic fever, although thrombocytopaenia with haemoconcentration and signs of a moderate consumptivecoagulopathy is suggestive of dengue.

The most widely used serological test is the HI test, detecting antibodies as early as 4 days post-onset. A specific diagnosis of dengue can be made early in primary infections, but cross-reactions with other flaviviruses occur in late primary or secondary infections. The IgM antibody capture ELISA (MAC ELISA) is being used during outbreaks of dengue, and there are now rapid assays available for the detection of dengue IgG and IgM, although crossreaction may occur with the IgG assay. The IgM antibodies may persist for over 3 months, so the test is also useful for retrospective studies, but this persistence may cause diagnostic problems in areas where dengue is endemic. A combined IgG and IgM assay, detecting high levels of IgG indicating secondary infection, is useful in dengue endemic areas. Immunofluorescent assays have been used successfully to detect dengue IgG and IgM antibodies. The CF test is more specific than the HI test, but the antibodies detected by this assay appear later and disappear earlier. The NT and PRNT tests are the most specific and sensitive but are difficult to perform and thus tend to be used only for specific purposes.

Virus isolation, the only definitive way of being able to type isolates, is difficult and if mice are used, a number of blind passages are usually required. Intracerebral inoculation of adult or larval Toxorhynchites spp. is a sensitive and rapid method for the isolation of dengue virus, giving results in 2–3 days. The use of a rapid centrifugation method may increase sensitivity and reduce time scales. Intrathoracic inoculation of mosquitoes is easier and just as sensitive, but head squashes cannot be made or tested for specific dengue antigen for at least 7 days post-inoculation.

The most commonly used system of virus isolation is the inoculation of mosquito cell lines, viz. A. albopictus (C6-36), A. pseudoscutellaris (AP-61) and Toxorhynchites

ambionensis (TRA-248), which are almost as sensitive as mosquito inoculation, which allows specific results to be obtained within 2–3 days using fluorescent- labelled monoclonal antibodies. A combination of MAC ELISA and RT-PCR on peripheral blood

Leukocytes have been shown to give high levels of sensitivity and specificity.

Laboratory diagnosis of dengue infection

(JAWETZ)

Reverse transcriptase- polymerase chain reaction based methods are available for rapid identification and serotyping of dengue virus in acute- phase serum, roughly during the period of fever. Isolation of the virus is difficult. The current favored approach is inoculation of a mosquito cell line with patient serum, coupled with nucleic acid assay to identify a recovered virus.

Serological diagnosis is complicated by cross- reactivity of IgG antibodies to heterologus falvivirus antigens. A variety of methods are available; the most commonly used methods are E/M viral protein- specific capture IgM or IgG ELISA and the hemagglutination inhibition test. IgM antibodies develop within a few days of illness. Neutralizing and hemagglutination- inhibiting antibodies appear within a week after onset of dengue fever. Analysis of paired acute and convalescent sera to show a significant rise in antibody titer is the most reliable evidence of an active dengue infection.

Agriculture Microbiology MCQ tribhuvan University 2

11. Dissolution of rocks is due to
a. Carbonic acid b. Organic acid c. freezing and thawing d. all of the above
12. In which depth in a garden soil does the maximum number of microorganisms per gram occur?
a. at a depth of 3-8 cm. b. at a depth of 1-3 cm c. at a depth of 8-12 cm d. at a depth of 12-25 cm
13. compound responsible for the distinctive “earthy” odor of soil is
a. Phytoalexins b. root exudates c. cellulose d. Geosmin
14. ………… is a common denitrifying bacteria?
a. Pseudomonas b. Nitrobacter c.frankia d. azospirillum
15. dissimilatory sulfur- reducing bacteria……………
a. can reduce elemental sulfur to sulfide but are unable to reduce sulfate to sulfide
b. cant reduce elemental sulfur to sulfide but can reduce sulfate to sulfide
c. can reduce both elemental sulfur and sulfate to sulfide
d. cant reduce both elemental sulfur and sulfate
16. Desulfuromonas is ………………..
a. obligate anaerobes b. sulfate reducing bacteria c. both of above d. facultative aerobe
17. Formation of “infection thread” in certain root hairs is due to
a. Rhizobium bacteria b. pathogenic bacteria c. pathogenic fungi
18. Organisms involved in non symbiotic nitrogen fixations are the species of;
a. Spp of Azotobacter b.Cyanobacteria c. Clostridium Pasteurianum d. all of the above
19. The amount of nitrogen fixed by the non symbiotic process ranges between
a. 20-50lb/acre annually b 50-100 lb/ acre annually c. >200 lb/acre annually
20. Nitrogenase enzyme complex contains component I an II……….
a. Nitrogenase and Nitrogenase reductase b. MoFe protein and Fe protein
c. Both of the above d. None of the above