Identification of Bordetella pertussis in nasopharyngeal swabs using the polymerase chain reaction: evaluation of detection methods
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R Lichtinghagen1, R Diedrich-Glaubitz, B von Hörsten
1Institut für Klinische Chemie I der Medizinischen Hochschule Hannover, Germany.
Abstract:
A 183 base pairs or 153 base pairs DNA fragment from a repetitive region of the Bordetella pertussis genome was amplified in a polymerase chain reaction. The sensitivities of three different detection methods (Enzymun Test, silver stained polyacrylamide gel, ethidium bromide stained agarose gel) after amplification by polymerase chain reaction showed that both a one-time polymerase chain reaction (35 cycles) with Enzymun testing as well as a nested polymerase chain reaction with either of the electrophoresis methods have high levels of sensitivity for detection of the infectious organism in nasopharyngeal swabs. Smears from 53 children with whooping cough and from 50 children without infections were analysed, using these methods. 51 patients with whooping cough gave positive test results, while 2 of the sick patients and all the control children gave negative results.
Insights
Detecting Bordetella pertussis (whooping cough) DNA in nasopharyngeal swabs is highly sensitive using polymerase chain reaction (PCR) combined with Enzymun testing or electrophoresis. This method accurately identified infectious organisms in children with whooping cough.
Area of Science:
- Microbiology
- Molecular Biology
- Infectious Diseases
Background:
- Bordetella pertussis causes whooping cough, a significant respiratory infection.
- Accurate and sensitive detection methods are crucial for diagnosing and controlling pertussis outbreaks.
Purpose of the Study:
- To evaluate the sensitivity of different polymerase chain reaction (PCR) based detection methods for Bordetella pertussis.
- To compare the efficacy of Enzymun testing and electrophoresis methods for identifying the infectious agent in clinical samples.
Main Methods:
- Amplification of a repetitive DNA fragment from Bordetella pertussis using PCR.
- Analysis of nasopharyngeal swab smears from children with and without whooping cough.
- Comparison of three detection methods: Enzymun Test, silver-stained polyacrylamide gel electrophoresis, and ethidium bromide-stained agarose gel electrophoresis.
Main Results:
- Both one-time PCR (35 cycles) with Enzymun testing and nested PCR with electrophoresis methods demonstrated high sensitivity.
- 51 out of 53 children with whooping cough tested positive.
- Only 2 sick children and none of the control children yielded positive results, indicating high specificity.
Conclusions:
- PCR combined with Enzymun testing or electrophoresis offers a highly sensitive and specific approach for detecting Bordetella pertussis in nasopharyngeal swabs.
- These molecular methods are effective for the diagnosis of whooping cough in pediatric populations.