RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES, KARNATAKA, BANGALORE
PROFORMA FOR REGISTRATION OF SUBJECTS FOR DISSERTATION
1. Name of the Candidate and Address (in block letters)
DR. T. M. NANDAN
S/O H. T. MANJUNATH
#1625/4, NEAR DOUBLE TANKS, NORTHERN EXTENSION
HASSAN-573201
TEMPORARY ADDRESS
DR. T. M. NANDAN
C/O M. S. BHAT
#111, 1ST FLOOR REAR
5TH C CROSS, 1ST PHASE, GIRINAGAR
BANGALORE-560085
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2. Name of the institution:
Kempegowda institute of medical sciences and research centre, Bangalore.
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3. Course of study and subject:
MD in MICROBIOLOGY
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4. Date of admission to the course:
26-05-07
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5. Title of the topic:
“ ANTIMICROBIAL RESISTANCE IN COLONIZING Streptococcus pneumoniae ISOLATED FROM CHILDREN”
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6. Brief resume of the intended work:
6.1 Need for the study.
o S.pneumoniae is the major cause of morbidity and mortality in India and abroad and carriage is the key to invasive disease [1, 12, 13].
o Carriage (20-60%) and invasive disease are more prevalent in children. [4, 6, 12]
o Increased case fatality is due to the emergence of Penicillin and Multidrug Resistant S.pneumoniae worldwide. Penicillin has been the drug of choice for treatment of pneumococcal infections but the increasing number of reports of penicillin resistant pneumococci (PRP) throughout the world makes it essential to determine the prevalence of PRP regionally.[10,11,13]
6.2 Review of literature.
Streptococcus pneumoniae was recognized as the major cause of pneumonia in the 1880s and has been a central focus of study. S. pneumoniae causes infections of the middle ear, sinuses, trachea, bronchi, and lungs by direct spread from the nasopharyngeal site of colonization. Infections of the CNS, heart valves, bones, joints, and peritoneal cavity usually arise by hematogenous spread; peritoneal infection also results from ascent via the fallopian tubes. The CNS may also be infected by contiguous spread of organisms, as in patients who have a tear in the dura. [4, 6]
Microbiology:
Pneumococci are identified in the clinical laboratory as gram-positive lanceolate diplococci that grow in chains and are catalase-negative. They produce pneumolysin, a toxin that breaks down hemoglobin into a greenish degradation product, thereby causing hemolysis on blood agar (5% horse, sheep or goat). More than 98% of pneumococcal isolates are susceptible to ethylhydrocupreine (optochin), and virtually all pneumococcal colonies are dissolved by bile salts. [2, 6]
Epidemiology:
S. pneumoniae colonizes the nasopharynx and, on any single occasion, can be isolated from 5 to 10% of healthy adults and from 20 to 60% of healthy children. Once the organisms have colonized, they are likely to persist for 4 to 6 weeks but may persist for as long as 6 months. [4, 6, 14]
The incidence of bacteremic pneumococcal infection is relatively high among children up to 2 years of age and low among teenagers and young adults; rates increase with increasing age beginning at around age 55. [4, 6]
Pneumococci spread from one individual to another by direct or droplet transmission as a result of close contact; transmission may be enhanced by crowding or poor ventilation. Day-care centers have been a site of spread, especially of penicillin-resistant strains. [4, 6]
Pathogenetic mechanisms:
S. pneumoniae attaches to human nasopharyngeal cells through the specific interaction of bacterial surface adhesins, such as pneumococcal surface antigen A or choline-binding proteins (including PspA), with epithelial cell receptors. [4, 6]
Once the nasopharynx has been colonized, infection results if the organisms are carried into anatomically contiguous areas such as the eustachian tubes or the nasal sinuses and if their clearance is hindered, for example, by mucosal edema due to allergy or viral infection. Similarly, pneumonia ensues if organisms are inhaled or aspirated into the bronchioles or alveoli and then are not cleared especially, for example, if viral infection or other toxic substances have increased mucus production and/or damaged ciliary action.
[4, 6]
The polysaccharide capsule renders the organisms resistant to opsonization, phagocytosis, and intracellular killing by phagocytic cells. The capacity to cause disease reflects the capacities of pneumococci to escape ingestion and killing by host phagocytic cells, on the one hand, and to stimulate an inflammatory response and damage tissues, on the other. [4, 6]
Patients with underlying defects in host defence mechanisms such as hypogammaglobulinemia, complement component deficiencies, asplenia are at increased risk for invasive pneumococcal disease. [4, 6]
Antimicrobial susceptibility:
Penicillin-susceptible pneumococci are susceptible to all commonly used cephalosporins. Penicillin-intermediate strains tend to be resistant to all first- and many second- generation cephalosporins (of which cefuroxime retains the best efficacy), but most are susceptible to certain third-generation cephalosporins, including cefotaxime, ceftriaxone, cefepime, and cefpodoxime. One-half of highly penicillin resistant pneumococci are also resistant to cefotaxime, ceftriaxone, and cefepime, and nearly all are resistant to cefpodoxime. [5,7]
About one-quarter of all pneumococcal isolates in the United States are resistant to erythromycin and the newer macrolides, including azithromycin and clarithromycin, with much higher rates of resistance in penicillin-resistant strains. This resistance will certainly affect empirical therapy for bronchitis, sinusitis, and pneumonia. [1, 6, 7, 5]
Pneumococcal susceptibility patterns vary greatly between and
even within individual communities, and the data are in a state of flux.
It does appear, however, that the constant trend is toward more widespread antibiotic resistance. [1, 6]
6.3 Objectives of the study.
1. To determine the carriage percentage of S.pneumoniae in children.
2. To study antimicrobial susceptibility patterns of S.pneumoniae isolates.
3. To determine Penicillin MIC for S.pneumoniae isolates.
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7. Materials and methods:
7.1 Source of data:
Children ≤5 years [4, 12] old attending Paediatric OPD and/or inpatients (within 24 hours), Kempegowda Institute of Medical Sciences and Research Centre, Bangalore.
Period of study: one year.
Sample size: ~250 [4, 12]
7.2 Method of collection of data (including sampling procedure, if any).
Inclusion Criteria [12, 13]:
o Children ≤ 5 years old attending Paediatric OPD and/or inpatients (within 24 hours), KIMS, Bangalore.
Exclusion Criteria [12, 13]:
o Recent (3 months) hospitalization.
o Current antibiotic therapy.
o Current or recent invasive pneumococcal disease.
o Known immunologic disorders.
o Consent refusal.
Sample collection [1, 3, 9]:
Nasopharyngeal/nasal samples will be taken with a nasopharyngeal or deep nasal swab (pediatric cotton tipped) according to convenience of the child after consent of the parent/guardian. To obtain the specimen the child’s head should be tipped slightly backward and the swab passed directly backwards, parallel to the floor of the nasopharynx. The swab should pass without resistance until it reaches the posterior pharynx which is approximately one-half to two-thirds the distance from the nostril to the ear lobe. If resistance is encountered, the swab should be removed, and an attempt should be made to pass the swab through the other nostril. Once the swab is in place, it should be rotated 180 degrees or left in place for 5s to saturate the tip before removing it slowly.
The specimens will be plated onto culture media for further processing.
Identification and characterization by culture and biochemical tests [1, 2]:
The plated 5% sheep blood agar [9] plates will be incubated at 35-37° C in
3-10% CO2 jar (candle jar [2]) for 24 h. Colonies typical of pneumococci will be selected and identified by optochin disc (inhibition zone ≥14 mm [1]) and will be confirmed by bile solubility test.
Antimicrobial susceptibility testing [1, 5]:
Antimicrobial susceptibility testing will be carried out by Kirby Bauer disc diffusion method as per NCCL guidelines (presently CLSI). For cefotaxime and ciprofloxacin, interpretation will be done as for other hemolytic streptococci. Penicillin minimum inhibitory concentration (MIC) for Oxacillin resistant (zones showing ≤ 19 mm) [1, 5] S.pneumoniae isolates will be determined by E-test [4].
7.3 Does the study require any investigations or interventions to be conducted on patients or other humans or animals? If so, please describe briefly.
Yes. Collection of nasopharyngeal/ nasal specimens from children will be carried out with consent of their parent/guardian.
7.4 Has ethical clearance been obtained from your institution in case of 7.3?
Yes. (Enclosed)
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8. List of references:
1. Goyal R, Singh, NP, Kaur M, Talwar V. Antimicrobial resistance in invasive and colonizing Streptococcus pneumoniae in north India. Indian Journal of Medical Microbiology 2007; 25(3): 256-9.
2. Forbes BA, Sahm DF, Weissfeld AS. Bailey and Scott’s diagnostic microbiology. 12th ed. Mosby; 2007.
3. Sleeman KL, Griffiths D, Shackley F, Diggle L, Gupta S, Maiden MC, et al. Capsular Serotype Specific Attack Rates and Duration of Carriage of Streptococcus pneumoniae in a Population of Children. JID 2006; 194: 682-88.
4. Winn WC Jr., Allen SD, Janda WM, Koneman EW, Procop GW, Schreckenberger PC, Woods GL, editors, Gram positive cocci, part 2, Koneman’s Color Atlas and Textbook of Diagnositc Microbiology, Lippincott Williams & Wilkins, 2006: 689-93.
5. Winn WC Jr., Allen SD, Janda WM, Koneman EW, Procop GW, Schreckenberger PC, Woods GL, editors, Antimicrobial Susceptibility Testing, Koneman’s Color Atlas and Textbook of Diagnositc Microbiology, Lippincott Williams & Wilkins, 2006: 1009-11.
6. Musher DM. Pneumococcal Infections. Kasper DL, Braunwald E, Fauci AS, Hauser SL, Longo DL, Jameson JL, editors, Harrison’s Principles of Internal Medicine, McGraw- Hill, 2005(vol 1): 806-14.
7. Jacobs MR, Bajaksouzian S, Windau A, Good CE, Lin G, Pankuch GA et al. Susceptibility of Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis to 17 oral antimicrobial agents based on pharmacodynamic parameters: 1998-2001 US Surveillance Study. Clin Lab Med 2004; 24: 503-530.
8. File TM Jr. Streptococcus pneumoniae and Community-Acquired Pneumonia: A Cause for Concern. The American Journal of Medicine 2004; 117(3A): 39S-50S.
9. O’Brien KL, Nohynek H. Report from a WHO Working Group: standard method for detecting upper respiratory carriage of Streptococcus pneumoniae. Pediatr Infect Dis J 2003; 22:e1-11.
10. Appelbaum PC. Resistance among Streptococcus pneumoniae: Implications for drug selection. Clin Infect Dis 2002; 34:1613-20.
11. Kanungo R, D’Lima D, Rajalakshmi B, Kumar A, Badrinath S. Emerging antibiotic resistant pneumococci in invasive infections in south India: Need for monitoring. Indian J Pharmacol 2002; 34:38-43.
12. Lee NY, Song JH, Kim S, Peck RK, Ahn KM, Lee SI, et al. Carriage of Antibiotic-Resistant Pneumococci among Asian Children: A multinational Surveillance by the Asian Network for Surveillance of Resistant Pathogens (ANSORP). Clin Infect Dis 2001; 32: 1463-9
13. Song JH, Lee NY, Ichiyama S, Yoshida R, Hirakata Y, Fu W, et al. Spread of drug resistant Streptococcus pneumoniae in Asian countries: Asian network for surveillance of resistant pathogens (ANSORP) study. Clin Infect Dis 1999;28: 1206-11.
14. Obaro S and Adegbola R. The pneumococcus: carriage, disease and conjugate vaccines. J Med Microbiol 2002; 51: 98-104.
9. Signature of the candidate:
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10. Remarks of the guide:
Emergence of penicillin and other antibiotic resistance among Streptococcus pneumoniae
and carriage being the predisposing factor for invasive disease and deaths in children in India and abroad, this study will be of benefit to the community of this region to tackle the burden of S.pneumoniae efficiently and will also be an attempt to establishing the need to eliminate colonizing S.pneumoniae by preventive and therapeutic measures.
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11. Name and designation of (in block letters)
11.1 Guide: DR. JAGADEESH, Professor, Department of Microbiology, Kempegowda Institute of Medical Sciences (KIMS), Bangalore.
11.2 Signature:
11.3 Co-guide: DR. S. R. KESHAVAMURTHY, Professor and Head of the Department of Paediatrics, Kempegowda Institute of Medical Sciences, Bangalore.
11.4 Signature:
11.5 Head of the Department: DR. K. L. RAVIKUMAR, Professor and Head of the Department of Microbiology, Kempegowda Institute of Medical Sciences, Bangalore.
11.6 Signature:
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12.1 Remarks of the Chairman and Principal:
12.2 Signature.
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