Actinomycosis is not Frequent in the Periapex But is a Persistent Lesion

A simplified method for detecting Gram-positive and Gram-negative bacteria in dental histological samples: A preliminary and comparative study

OBJECTIVE

Bacteria identification inside the dental tissue is a complex procedure requiring specific protocols. This study aimed to compare two classical Gram staining methods with a new staining method proposed by the authors to detect Gram-positive and Gram-negative bacteria in dental histological samples of human dentin.

METHODS

Ten human teeth, extracted because of various pathologies, were decalcified, dehydrated, and paraffin-embedded. Then, approximately 100 serial sections of 4 µm thickness were made per sample. The serial sections were placed on glass slides and were stained according to Brown-Brenn, Brown-Hopps, and a proposed modification of Brown-Brenn staining. Both ATCC strains, smeared on glass slides, were stained following each method's instructions used in histological samples.

RESULTS

From a qualitative evaluation, the Brown-Brenn method resulted in better staining of Gram-positive bacteria, while the authors' proposed staining technique was more oriented towards Gram-negative bacteria. On the other hand, the Brown-Hopps showed quite a balance in detecting Gram-positive and Gram-negative bacteria. Unlike the Brown-Brenn stain, the other two protocols showed better stainability of Gram-negative microorganisms in bacterial-smeared samples.

CONCLUSION

All staining techniques evaluated in this article can identify bacteria, but the outcome can change according to the staining procedure used.

Florid cemento-osseous dysplasia-related osteonecrosis: A series of cases

OBJECTIVE

The aim of this study was to assess the clinicopathological features of florid cemento-osseous dysplasia (FCOD)-related osteonecrosis highlighting their histopathological aspects and bone structure.

METHODS

Twenty-two FCOD-related osteonecrosis cases were evaluated retrospectively. Osteonecrosis, osteomyelitis, bacterial colonization, bone resorption, reactive bone, osteon-like structure, lamellar bone, and basophilic lines were analyzed. Specific staining and fluorescence and polarized light microscopy analyses were also performed.

RESULTS

The mandible was more affected by FCOD-related osteonecrosis. There was a predominance of African-Brazilian women in the fifth and seventh decades of life. Osteomyelitis was present in 82 % of cases whereas bone resorption and bacterial colonization were present in 100 % of FCOD-related osteonecrosis cases. Thick basophilic lines were seen in all cases (100 %). Actinomycosis and osteoclasts were not often.

CONCLUSIONS

This study showed female adult preference, mandibular location, and some findings such as osteomyelitis, bone resorption, and bacterial colonization were histopathological features more frequent in FCOD-related osteonecrosis. In the absence of a close clinical and radiographic correlation, the morphology of the necrotized bone similar to cementum could help to recognize FCOD.

Clinical Characteristics of Actinomyces viscosus Bacteremia

Background and Objectives: Actinomyces species are part of the normal flora of humans and rarely cause disease. It is an uncommon cause of disease in humans. The clinical features of actinomycosis have been described, and various anatomical sites (such as face, bones and joints, respiratory tract, genitourinary tract, digestive tract, central nervous system, skin, and soft tissue structures) can be affected. It is not easy to identify actinomycosis because it sometimes mimics cancer due to under-recognition. As new diagnostic methods have been applied, Actinomyces can now more easily be identified at the species level. Recent studies have also highlighted differences among Actinomyces species. We report a case of Actinomyces viscosus bacteremia with cutaneous actinomycosis. Materials and Methods: A 66 years old male developed fever for a day with progressive right lower-leg erythematous swelling. Blood culture isolates yielded Actinomyces species, which was identified as Actinomyces viscosus by sequencing of the 16S rRNA gene. In addition, we searched for the term Actinomyces or actinomycosis cross-referenced with bacteremia or "blood culture" or "blood stream" from January 2010 to July 2020. The infectious diseases caused by species of A. viscosus from January 1977 to July 2020 were also reviewed. Results: The patient recovered well after intravenous ampicillin treatment. Poor oral hygiene was confirmed by dental examination. There were no disease relapses during the following period. Most cases of actinomycosis can be treated with penicillin. However, clinical alertness, risk factor evaluation, and identification of Actinomyces species can prevent inappropriate antibiotic or intervention. We also compiled a total of 18 cases of Actinomyces bacteremia after conducting an online database search. Conclusions: In summary, we describe a case of fever and progressive cellulitis. Actinomyces species was isolated from blood culture, which was further identified as Actinomyces viscosus by 16S rRNA sequencing. The cellulitis improved after pathogen-directed antibiotics. Evaluation of risk factors in patients with Actinomyces bacteremia and further identification of the Actinomyces species are recommended for successful treatment.

Prevalence of Bacteria of Genus Actinomyces in Persistent Extraradicular Lesions-Systematic Review

Actinomyces are anaerobic, rod-shaped, Gram-positive bacteria. They are associated with persistent extraradicular endodontic infections, with possible involvement of the soft tissues of the maxillofacial district. Many studies reported conflicting data on the presence of bacteria of the genus Actinomyces in endodontic infections. The aim of this systematic review of the literature was to determine the real prevalence of such bacteria in primary and/or secondary endodontic infections and in cases of persistence with extraradicular involvement. This systematic review was performed according to the PRISMA protocol. A search was carried out through the Scopus and PubMed databases of potentially eligible articles through the use of appropriate keywords. The literature research resulted in preliminary 2240 records which, after the elimination of overlaps and the application of inclusion and exclusion criteria, led to the inclusion of 46 articles focusing on three outcomes (primary outcome: number of teeth with the presence of a persistent extraradicular infection in which the presence of Actinomyces was ascertained; secondary outcome: number of teeth with endodontic infection in which the presence of Actinomyces was assessed; tertiary outcome: difference in the prevalence of bacteria of the genus Actinomyces between primary endodontic infections and secondary endodontic infections). Results of the meta-analysis show how bacteria of the genus Actinomyces are present in primary and secondary intraradicular infections and in those with persistence with a prevalence (ratio between teeth with actinomyces and teeth with infection) ranging from 0.091 up to 0.130 depending on the subgroups analyzed.

"Holes" in the Jaw-A Report of Two Cases of Periapical Actinomycosis

Periapical actinomycosis is a relatively rare form of cervicofacial actinomycosis, which typically involves the periapical region with subsequent potential spread to the jaw bones. We hereby present two cases of periapical actinomycosis. Both patients presented with jaw pain and "holes" in their gum and lacked the characteristic clinical features commonly seen in cervicofacial actinomycosis such as jaw mass, draining ulcers, sinuses and fistulae. The first patient was an immunocompetent host with chronic stable medical conditions but with a rather bad dentition requiring multiple recent teeth extractions. The second patient was edentulous, had refractory multiple myeloma, was on low-dose chronic steroids and pomalidomide therapy and therefore relatively immunocompromised. Both cases of actinomycosis were diagnosed by jaw bone histopathology, which showed characteristic sulfur granules and embedded Actinomyces-like organisms. The two patients had excellent clinical response to six months of penicillin therapy without any need for surgical intervention. The cases remind clinicians of including actinomycosis in the differential diagnosis of periapical lesions and illustrates the possibility of achieving cure with non-surgical treatment.