American Journal of Infectious Diseases and Microbiology
ISSN (Print): 2328-4056 ISSN (Online): 2328-4064 Website: Editor-in-chief: Maysaa El Sayed Zaki
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American Journal of Infectious Diseases and Microbiology. 2017, 5(3), 100-105
DOI: 10.12691/ajidm-5-3-1
Open AccessArticle

Phenotypic Characterization and Serotypes Identification of CSF isolates in Acute Bacterial Meningitis

Birhanemeskel Tegene1, , Kassahun Denekew2 and Gashaw Mesele3

1Department of Medical Microbiology, college of Medicine and Health Sciences, University of Gondar, Ethiopia

2Department of Pediatrics and Child Health, college of Medicine and Health Sciences, University of Gondar, Ethiopia

3Department of Surgery, Faculty of Medicine and Health Sciences, University of Gondar, Ethiopia

Pub. Date: May 31, 2017

Cite this paper:
Birhanemeskel Tegene, Kassahun Denekew and Gashaw Mesele. Phenotypic Characterization and Serotypes Identification of CSF isolates in Acute Bacterial Meningitis. American Journal of Infectious Diseases and Microbiology. 2017; 5(3):100-105. doi: 10.12691/ajidm-5-3-1


Background and Aim: Bacterial meningitis is a fatal disabling disease which needs prompt antibiotic management. As it causes a significant morbidity and mortality throughout the world, every developing country should have accurate information regarding the common etiological agents in bacterial meningitis cases. In the present study, we have serotyped the obtained agents in order to predict the usefulness of existing vaccines against bacterial meningitis. Materials and Methods: Two thousand nineteen cerebrospinal fluid (CSF) samples were obtained prospectively from suspected meningitis from January 2011 to July 2013 out of which 76 cases were approved by cytological, microbiological, molecular, and biochemical analysis as per the standard techniques. The isolated bacteria were serotyped to determine the predominant strain. Results: On the whole, 2019 CSF samples were collected, and bacterial etiology was isolated in 76 cases; S. pneumoniae in 31.5%, N. meningitides in 18.4%, and H. influenza in 10.5% of culture positive samples. Gram stained smears were positive in 63 samples. Among pneumococcal meningitis the most common serotype was 1, (29 %), followed by 19F, (25%), 18F, (8.3%), 6, (16.6%), 14, (12.5%), and 20 (8.3%). Out of the N. meningitidis positive CSF samples, 35.7%, 21.4%, and 35.7%, belonged to serogroups A, C, and W-135, respectively, and one non-groupable isolate were involved as S. pneumoniae meningitis. In the H. influenzae group only serotype b (87.5%), and untypable, 1, (7.5%) cases have been identified. Only 17, (0.8%) soluble antigens were detected from culture negative CSF samples. High protein and low sugar levels associated well with the features of ABM. The mean sugar and protein level in the CSF samples were 22.3 ± 9.8 mg/dl, 85.3 ± 51.29 mg/dl, respectively. Conclusions: The isolation rate of bacteria causing meningitis is 3.8%. Out of the total pneumococcal serotypes three of them were not included in the current vaccine in Ethiopia. Unusual findings and high a proportion of serogroup W-135 meningococci are observed in our study area The role of clinical presentations, routine CSF analysis in the rapid diagnosis of acute bacterial meningitis in cases of negative gram stained smears and a good knowledge of the bacterial epidemiology of meningitis can serve as a guide to start a rapid treatment as early as possible. Recommendation: the result of this study can be used to improve the existing vaccines to cover the detected serotypes and consequently reduce the incidence of bacterial meningitis.

acute bacterial meningitis neisseria meningitids streptococcus pneumoniae huemophilus and latex agglutination test

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[1]  Prober CG. Central Nervous System Infections. In: Nelson’s Textbook of Pediatrics 18th edition. Kliegman RM, Behrman RE, Jenson HB, Stanton BF editors, Elsevier, New Delhi 2008; 2512-21.
[2]  Scheld WM, Koedel U, Nathan B, Pfister HW. athophysiology of bacterial meningitis: mechanism(s) of neuronal injury. J Infect Dis 2002; 186 (2): 225-233.
[3]  Osrin D, Vergnano S, Costello A. Serious bacterial infections in newborn infants in developing countries. Curr Opin Infect Dis 2004; 17: 217-224.
[4]  Grimwood K, Anderson VA, Bond L, Catroppa C, Hore RL, Keir EH, et al. Adverse outcomes of bacterial meningitis in school-age survivors. Pediatrics 1995; 95:646-656.
[5]  World Health Organization. Control of epidemic meningococcal diseases. WHO Practical Guidelines.2 ed. 1998. Geneva Switzerland.
[6]  Puopolo KM. acterial and fungal infections.In Manual of Neonatal care 4thed. Cloherty JP, Eichenwald EC, StarkAR editors Lippincott- Raven, Philadelphia 2008: 274-93.
[7]  Solberg C.O. Meningococcal infections, In Fauci A.S., Braunwald E, Isselbacher K.J, et al (eds.), Harrison’s principles of internal medicine, 14th ed. McGraw- Hill, New York USA 1998; 9: 910-15.
[8]  WHO (2012). Bacterial meningitis. meningitis.
[9]  Tunkel AR. Clinical Trials Report. Curr Infect Dis Rep 2001; 3:347-351.
[10]  Mengistu G., Mitiku K., Teferi W., (2003). Analysis and reporting of meningococcal meningitis epidemic in north Gondar. Ethiopia Medical Journal.; 41(4): 319-31.
[11]  Laving AM, Musoke RN, Wasunna AO, Revathi G. Neonatal bacterial meningitis at the newborn unit of Kenyatta National Hospital. East Afr Med J 2003; 80:456-462.
[12]  Norheim G., Rosenqvist E., Assefa A., et al, (2006). Nesseria meningitis isolated from recent out breaks in Ethiopia and comparison with those Recovered during the epidemic of 1988 to 1989. Jornal of clinical microbiology. 44:861-871.
[13]  Brooks G, Caroll K, Butel J, Morse SA, Mietzner TA. Jawetz Melnick & Adelbergs Medical Microbiology 26/E edn.The McGraw-Hill Companies, Inc. N.Y 2013.
[14]  Clinical and Laboratory Standards Institute. Performance standards for antimicrobial susceptibility testing. 16th informational supplement (M100-S16). Wayne, PA: CLSI, 2006.
[15]  Bauer AW, Kirby WMM, Sherris JC, Turck M. Antibiotics susceptibility testing by a standardised single disc method. Am J Clin Pathol 1966; 45: 493-6.
[16]  National Committee for Clinical Laboratory Standards. Performance standards for antimicrobial disk susceptibility test, 7th ed. Approved standards, NCCLS Document.
[17]  Mohammad M, Abdolreza G, Mirkaveh M, Noushin D. Identification of the serotypes of bacterial meningitis agents; implication for vaccine usage Iranian journal of microbiology; Volume 6 Number 4 (August 2014) 211-218.
[18]  Andargachew M, Afework K, Belay T, Bacterial isolates from cerebrospinal fluids and their antibiotic susceptibility patterns in Gondar University Teaching Hospital, Northwest Ethiopia; Ethiop.J.Health Dev. 2005; 19(2).
[19]  Syamal M., Amit Kumar A., Phenotypic Characterization and antibiogram of CSF Isolates in Acute Bacterial Meningitis; Journal of Clinical and Diagnostic Research. 2013 Dec, Vol-7(12): 2704-2708.
[20]  Birhanemeskel T, Solomon G, Nigus F Bacterial Meningitis: a five-year retrospective study among patients who had attended at University of Gondar Teaching Hospital, Northwest Ethiopia. Journal of Biomedical Research and Therapy 2015, 2(5): 270-278.
[21]  Miller E, Andrews NJ, Waight PA, Slack MP, George RC. Effectiveness of the new serotypes in the 13-valent pneumococcal conjugate vaccine. Vaccine; 29:9127- 9131.
[22]  Hsu HE, Shutt KA, Moore MR, Beall BW, Bennett NM, Craig AS, et al. Effect of pneumococcal conjugate vaccine on pneumococcal meningitis. N Engl J Med 2009; 360:244-256.
[23]  Schuchat A, Robinson K, Wenger JD, Harrison LH, Farley M, Reingold AL, Lefkowitz L, Perkins BA. Bacterial meningitis in the United States in 1995. Active Surveillance Team. N Eng J Med. 1997; 337: 970-76.
[24]  Rabab F, Marwa K, Waleed F, Taha G, et al. Role of Clinical Presentations and Routine CSF Analysis in the Rapid Diagnosis of Acute Bacterial Meningitis in Cases of Negative Gram Stained Smears, Journal of Tropical Medicine Volume 2014, Article ID 213762, 7 pages.
[25]  Lund E, Henrichsen J. Laboratory diagnosis, serology and epidemiology of Streptococcus pneumoniae. Methods Microbiol 1978; 12: 241-262.
[26]  Davis S, Feikin D, Johnson HL. The effect of Haemophilus influenzae type B and pneumococcal conjugate vaccines on childhood meningitis mortality: a systematic review. BMC Public Health 2013; 13 Suppl 3: S21.