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Identification of group B streptococci in tissue sections using the peroxidase-antiperoxidase method: a retrospective
Abstract:
The peroxidase-antiperoxidase (PAP) method was used to demonstrate group B streptococci in formalin-fixed, paraffin-embedded tissue sections using commercial group specific streptococcal antiserum. Sections from neonatal necropsies in which postmortem lung cultures were positive for group B streptococci showed positively stained intra- and extra-cellular cocci in the alveolar exudate. Many hyaline membranes contained intact organisms whereas some membranes showed only diffuse positive staining. One case of neonatal death was evaluated in which there was a clinical diagnosis of group B streptococcal infection, but postmortem cultures were not obtained. Group B streptococci were identified in the lung by the PAP method. This method may be of assistance in the postmortem evaluation of certain infectious diseases such as those due to group B streptococci.
Insights
The peroxidase-antiperoxidase (PAP) method successfully identified group B streptococci in neonatal lung tissues. This technique aids in diagnosing infectious diseases when cultures are unavailable.
Area of Science:
- Medical Microbiology
- Immunohistochemistry
- Pathology
Background:
- Group B Streptococcus (GBS) is a significant cause of neonatal infections.
- Accurate postmortem diagnosis is crucial for understanding neonatal mortality.
- Traditional culture methods may be limited in certain postmortem scenarios.
Purpose of the Study:
- To evaluate the efficacy of the peroxidase-antiperoxidase (PAP) method for detecting GBS in formalin-fixed, paraffin-embedded neonatal tissues.
- To assess the utility of PAP staining in cases where postmortem cultures were not obtained or were negative.
Main Methods:
- Utilized a commercial group-specific streptococcal antiserum with the PAP technique.
- Applied the method to formalin-fixed, paraffin-embedded lung tissue sections from neonatal necropsies.
- Compared PAP staining results with postmortem culture data where available.
Main Results:
- Positively stained intra- and extracellular cocci were observed in alveolar exudate in confirmed GBS cases.
- Intact GBS organisms were found within hyaline membranes, with some showing diffuse staining.
- The PAP method successfully identified GBS in lung tissue from a neonatal death with a clinical diagnosis but no cultures.
Conclusions:
- The peroxidase-antiperoxidase (PAP) method is effective for demonstrating group B streptococci in neonatal lung tissue.
- This immunohistochemical technique can aid in the postmortem diagnosis of GBS infections, especially when cultures are not feasible.
- PAP staining offers a valuable tool for evaluating infectious diseases in challenging postmortem cases.