Root canal microorganisms and their antibiotic susceptibility in patients with persistent endodontic infections, with and without clinical symptoms.

Secondary/persistent infections are present in teeth with previous root canal treatment, and a great variety of anaerobic microorganisms has been observed in these infections. The antibiotics prescription is occasional; however, in some cases, it is essential, particularly when the general health condition of the patient is compromised. The aims of this study were to identify the associated microorganisms in diagnosis of persistent or secondary apical periodontitis and to evaluate the susceptibility level to the antibiotics most used. Fifteen patients with persistent or secondary apical periodontitis requiring endodontic re-treatment were included. Microbiological samples were taken from the root canals and incubated in thioglycollate under anaerobic conditions. Anaerobic CDC agar (formulated by the Center for Disease Control and Prevention) was employed as a culture medium and the microorganisms were identified using the API system. The microorganisms were subjected to antibiograms with three different antibiotics. Twenty-six microorganisms were identified, the most common genus was Enterococcus (26.8%), Streptococcus (19.22%), Aerococcus (19.1%), and Clostridium (11.4%). 48% of them were susceptible to amoxicillin, with 28% of resistance. For clavulanic acid/amoxicillin, the susceptibility occurred in 32%, with 28% of resistance; and for clindamycin, the susceptibility was present in 40%, with 52% of resistance. The most frequently detected associated microorganism for secondary infections was genus Enterococcus, which exhibited high resistance to the studied antibiotics.

Aerobic and anaerobic microorganisms and antibiotic sensitivity of odontogenic maxillofacial infections.

This study aimed to identify the aerobic and anaerobic causal microorganisms of odontogenic infections and their antibiotic sensitivity. Purulent exudates were taken from patients with odontogenic infections by transdermal puncture, and aerobic and anaerobic microorganisms were identified using biochemical tests. Susceptibility to antibiotics was tested using the Kirby-Bauer method; the inhibition halos were measured according to NCCLS, and based on the results, the microorganisms were classified as susceptible, intermediate or resistant to each antibiotic. Frequencies of species and percentages of resistance were calculated. The microorganisms associated with odontogenic infections were principally anaerobic (65.3% anaerobic vs. 35.7% aerobic), and the susceptibility to antibiotics was higher in anaerobic than in aerobic microorganisms. The majority of isolated microorganisms (82%) showed susceptibility to amoxicillin/clavulanic acid. The causal agents of odontogenic infections were anaerobic microorganisms, which exhibited high resistance to antibiotics.

Chronic Bi-Maxillary Osteomyelitis Caused by Actinomycetes in a Patient with Severe COVID-19 / Osteomyelitis bi-maxilar crónica causada por Actinomycetes en un paciente con COVID-19 severo

Abstract Osteomyelitis is defined as the inflammation of the either medullary, cortical, or cancellous bone, including nerves and blood vessels, causing necrosis and bone sequestrum formation; this condition has become a rare pathology, and odontogenic infections are considered the most frequent causal factor. This case shows a patient with bi-maxillary osteomyelitis caused by Actinomyces spp, which was worsened for severe COVID-19 infection. Patient was submitted at surgery as, amplified total bilateral maxillectomy through the surgical technique Weber-Fergusson, and prolonged use of combination of antibiotics, achieved a good recovery. Two years later follow- up, the patient no show imaging or clinical evidence of the infection of osteomyelitis. The present case shows an interesting relationship between a rare infection and its association with COVID-19.

Resumen La osteomielitis se define como la inflamación del hueso medular, cortical o esponjoso, incluyendo nervios y vasos sanguíneos, causando necrosis y formación de secuestro óseo; esta condición es una patología rara, y las infecciones odontogénicas son consideradas como el factor causal más frecuente. En este caso, se muestra un paciente con osteomielitis bi-maxilar causada por Actinomyces spp, la cual empeoró por la infección de COVID-19 severo. El paciente fue sometido a una cirugía, maxilectomía bilateral total amplificada, a través de la técnica quirúrgica de Weber- Fergusson, y el uso prolongado de una combinación de antibióticos, logrando una buena recuperación. A los 2 años de seguimiento, el paciente no mostró evidencia clínica o imagenológica de la infección de osteomielitis. El presente caso muestra una interesante relación entre una infección rara y su asociación con COVID-19.