Retropharyngeal abscess due to actinomyces species in an immunocompromised patient: case report

Bacterial and histopathological findings in deep head and neck infections: a retrospective analysis

OBJECTIVES

Deep neck infections are among the most dangerous acute diseases in the head and neck region. This analysis gives an overview of the bacterial and histopathologic findings of deep neck infections.

STUDY DESIGN

From January 2002 to December 2012, 63 patients were diagnosed with and treated for deep neck infections at the University Medical Center Göttingen. Bacterial and histopathologic examinations were made, and the occurrence of bacterial pathogens and histopathologic findings were analyzed.

RESULTS

The most commonly isolated aerobic gram-positive pathogen was Streptococcus viridans (26.7%); Staphylococcus epidermidis and Staphylococcus aureus were each found in 16.7% of infections. The most commonly isolated aerobic gram-negative pathogens were Escherichia coli, Klebsiella oxytoca, and Haemophilus influenzae. In 1.6% of patients, a malignant cancer was detected.

CONCLUSION

For clear diagnosis and effective therapy, a bacteriologic investigation of deep neck infections is essential because of the heterogeneous spectrum of the detected bacteria. In contrast to Asia, where Klebsiella pneumoniae is the most common pathogen, in South Lower Saxony, Germany, we discovered a dominating spectrum of aerobic gram-positive cocci. Biopsy obtained from an abscess cavity for histologic examination should always be part of the diagnostic process in order to exclude a malignant process.

Actinomyces and related organisms in human infections

Actinomyces israelii has long been recognized as a causative agent of actinomycosis. During the past 3 decades, a large number of novel Actinomyces species have been described. Their detection and identification in clinical microbiology laboratories and recognition as pathogens in clinical settings can be challenging. With the introduction of advanced molecular methods, knowledge about their clinical relevance is gradually increasing, and the spectrum of diseases associated with Actinomyces and Actinomyces-like organisms is widening accordingly; for example, Actinomyces meyeri, Actinomyces neuii, and Actinomyces turicensis as well as Actinotignum (formerly Actinobaculum) schaalii are emerging as important causes of specific infections at various body sites. In the present review, we have gathered this information to provide a comprehensive and microbiologically consistent overview of the significance of Actinomyces and some closely related taxa in human infections.