meningitis – afrjcem.org

*^1,3Peletiri, I. C., ¹Ikeh, E. I., ²Nna, E.,³Ndike, U. P., ⁴Usman, Y. B., ⁵Durfa, L. D., ⁶Okonkwo, C. N., ⁷Murtala, R., and ²Nnajide, C. R.

¹Department of Medical Microbiology, Faculty of Clinical Sciences, College of Health Sciences, University of Jos, Nigeria

²Safety Molecular Pathology Laboratory, The Molecular Pathology Institute, Enugu, Enugu State, Nigeria

³Medical Microbiology & Parasitology Laboratories, National Hospital, Abuja, Nigeria

⁴Public Health Laboratory, Ministry of Health, Kebbi, Kebbi State, Nigeria

⁵Microbiology Laboratory, Plateau State Specialist Hospital, Jos, Nigeria

⁶Medical Laboratory Department, Specialist Hospital, Sokoto, Sokoto State, Nigeria

⁷Medical Laboratory Services, Ahmad Sani Yariman Specialist Hospital, Gusau, Zamfara State, Nigeria *Correspondence to: kumochris@hotmail.com

Abstract:

Background: Following an increase in the practice of starting antimicrobial therapy prior to clinical sample collection, the ability to confirm pathogenic microorganisms of bacterial meningitis has decreased by approximately 30%. Culture results may be false negative when fastidious or culture-resistant bacteria are involved or when patient samples are obtained after antimicrobial therapy has started. Molecular diagnosis using PCR can be performed directly on clinical samples after metagenomic DNA (mDNA) extraction not requiring live organisms for a positive result. The specific objectives of this study are to perform mDNA extraction directly from cerebrospinal fluids (CSF) using appropriate spin column method, and to determine the quality of the mDNA elute.

Methodology: Cerebrospinal fluid specimens were collected from 210 patients with suspected acute cerebrospinal meningitis (CSM) in the Federal Capital Territory and some States in Northern Nigeria during the 2017 and 2018 outbreak seasons. Metagenomic DNA was extracted from approximately 200µL of CSF specimens using the Qiagen QIAamp^(R) DNA Mini kit specific for bacterial agents only. DNA quality check was performed on all DNA elutes using fluorometric, spectrophotometric and agarose gel electrophoresis methods. Continue reading “Quality of metagenomic DNA extracted for molecular identification of microorganisms from CSF samples of patients with suspected cerebrospinal meningitis in northern Nigeria”

Y Chaibou, M Congo/Ouedraogo, I Sanou, H Somlare, K Ouattara, CM Kienou, H Belem, E Sampo, SA Traore, R Traore/Ouedraogo, C Hatcher, L Mayer, X Wang, L Sangare

Abstract

Purpose of study: The aim of this study was to determine the value of real-time Polymerase Chain Reaction (rt-PCR) in the routine surveillance of pneumococcal meningitis in Burkina Faso, compared to standard methods of culture, Gram stain and latex agglutination assay.
Materiel and methods: A total of 385 specimens of cerebrospinal fluid were analyzed by the three standard bacteriological methods (Gram stain, latex agglutination assay, and culture) and real-time Polymerase Chain Reaction.
Results: Of 385 specimens analyzed by these methods, 204 S. pneumoniae were detected by one or more methods. Gram stain detected 36.4% (140/385) Gram positive encapsulated diplococci; 37.7% (145/385) and 20.8% (80/385) of the specimens were positive for pneumococci by latex agglutination assay and culture. These specimens were tested with rt-PCR, which confirmed 51.2% (197/385) S. pneumoniae positive. The sensitivity and specificity of culture were 54.4% and 31.5%, respectively, and the sensitivity and specificity of rt-PCR were 96.6% and 100%, respectively. These results showed that rt-PCR was more sensitive than Gram stain (p=0.0235), latex agglutination assay (p=0.0442)and culture (p=0.0006).The culture is the gold standard method; however, the result showed that rt-PCR had specificity and was as specific as Gram stain (p=0.3405) and latex agglutination assay (p=0.7745).
Conclusion: rt-PCR was highly sensitive and specific. It could be used as a complementary diagnostic tool to mprove case confirmation of bacterial meningitis. However,its high cost, the qualification of the technical staff and infrastructures required for its implementation, constitute obstacles to its widened use in countries with limited resources.

Keywords: Streptococcus pneumoniae, meningitis, rt-PCR, standard bacteriological methods

Objectif: Le but de cette étude était de déterminer la place de la rt-PCR dans la surveillance de routine de
méningitespneumococciquesau Burkina Faso et la comparée avec les méthodes de la bactériologie classique: Culture, coloration de Gram et l’agglutination au latex.
Matériel etméthodes: Au total, 385 échantillons deliquides céphalorachidiens (LCR)étaient analysés par les trois méthodes de la bactériologie classique (coloration de Gram, agglutination au latex, culture) et la PCR en temps réel.

RESULTATS: Parmi 385 échantillons analysés, 204 cas de Streptococcuspneumoniae étaient détectés par une ou plusieurs méthodes. La coloration de Gram adétecté 36,4% (140/385) diplocoques encapsulés à Gram positif (DGP); 37,7% (145/385) et 20,8% (80/385) d’échantillons étaient positifs aux pneumocoques par l’agglutination au latex et la culture. Ces échantillons étaient aussi testés par rt-PCR qui a confirmé 51,2% (197/385) cas positifs de S. pneumoniae. La sensibilité et la spécificité de la culture étaient respectivement de 54,4% et 31,5%, et la sensibilité et la spécificité de rt-PCR étaient respectivement de 96,6% et 100%. Ces résultats ont montré que la rt-PCR était plus sensible que la coloration de Gram (p=0,0235), l’agglutination au latex (p=0,0442) et la culture(p=0,0006).La culture est une méthode de référence; cependant, le résultat a montré que rt-PCR était plus sensibleet aussi spécifique que la coloration de Gram ((p=0,3405)et l’agglutination au latex (p=0,7745).
Conclusion : :rt-PCR était plus sensible et plus spécifique. Elle pourrait être utilisée comme un outil de diagnostic
complémentaire pour améliorer les cas de confirmation de méningites bactériennes. Cependant, ces coûts de réalisation, la qualification de techniciens et les matériels pour son application constituent des obstacles pour sa vulgarisation dans les pays à ressources limités.

Keywords: Streptococcus pneumoniae, méningites, rt-PCR, méthodes de la bactériologie classique

Article in English.

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Polymerase Chain Reaction (PCR) provides a superior tool for the diagnosis of Pneumococcal Infection in Burkina Faso