PurposeThe goal of this study was to characterize the patterns of antimicrobial resistance and virulence genes in samples of Staphylococcus aureus (S. aureus) isolated from periodontitis patients.MethodsFrom July 2015 to August 2015, oral saliva was collected from a total of 112 patients diagnosed with periodontitis, including 80 outpatients in dental hospitals and 32 patients in dental clinics located in Seoul and Cheonan. The samples were subjected to a susceptibility test to evaluate the prevalence of antimicrobial resistance, and the pathogenic factors and antimicrobial resistance factors in the DNA of S. aureus were analyzed using polymerase chain reaction.ResultsA susceptibility test against 15 antimicrobial agents showed that 88% of cultures were resistant to ampicillin, 88% to penicillin, and 2% to oxacillin. Resistance to at least two drugs was observed in 90% of cultures, and the most common pattern of multidrug resistance was to ampicillin and penicillin. Enterotoxins were detected in 65.9% of samples. The cell hemolysin gene hld was detected in 100% of cultures and hla was detected in 97.6% of samples. All strains resistant to penicillin and ampicillin had the blaZ gene. The aph(3′)IIIa gene, which encodes an aminoglycoside modifying enzyme, was detected in 46.3% of samples.ConclusionsIn the treatment of oral S. aureus infections, it is important to identify the pathogenic genes and the extent of antimicrobial resistance. Furthermore, it is necessary to study patterns of antimicrobial resistance and cross-infection in the context of periodontological specialties in which antimicrobials are frequently used, such as maxillofacial surgery, where the frequency of antimicrobial use for minor procedures such as implant placement is increasing.

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Oral keratinocytes of buccal and gingival tissues undergo a terminal differentiation program to form a protective epithelial barrier as non-keratinized or parakeratinized stratified cells. We have examined the protein composition of cell envelopes (CEs) from normal human buccal and gingival tissues as well as keratinocytes from normal human gingival cells grown in culture. Biochemical and sequencing analyses reveal that the CEs contain 60^70% small proline-rich protein 1a/b (SPR1a/b), together with smaller amounts of involucrin, annexin I and several other known CE proteins. The data imply a specialized role for SPR1 proteins in the unique barrier function requirements of oral epithelia. ß

Background and aims:The odontoma is the most common benign tumor of odontogenic origin, characterized by mixed histological features and diverse clinical presentation. The purpose of this study was to review clinicopathologic features of odontomas arising from oral and maxillofacial area in Korean patients. Methods: Sixty cases of odontoma were analyzed for their prevalence, clinical and pathological findings. Results: Clinical symptoms showed delayed eruption (n = 9) of either the deciduous or permanent tooth, intra-or extra-oral swelling (n = 27), pain (n = 6), but 18 cases had no subjective symptoms. Seventy percent of the odontomas were associated with unerupted teeth. The location of the tumor was maxilla in 55% and mandible in 45% of cases. There were 55% in the anterosuperier sector and 25% in the posteroinferior zone, while the rest in the upper molar region. Compound odontoma was more common (60%) than complex odontoma. Compound odontoma showed a mean age of 18.5 years, in the incisor/canine area of the maxilla, and smaller tumors (5-30 mm) with unilocular and multiple radio-opaque miniteeth surrounded by defined radiolucency. The complex odontoma showed a mean age of 30.1 years, in the first and second molar of the mandible, and larger tumors (10-60 mm) with unilocular undistinguished radio-opaque mass surrounded by radiolucent zone and a distinct radio-opaque border. Conclusions: The clinicopathologic pattern of odontomas can be divided into compound and complex odontomas, while the definitive diagnosis of odontomas was based on the pathological examination after surgical removal of the tumor.