Role of CRISPR-Cas system on antibiotic resistance patterns of Enterococcus faecalis.

Clustered regularly interspaced short palindromic repeat (CRISPR)-Cas systems are one of the factors which can contribute to limiting the development and evolution of antibiotic resistance in bacteria. There are three genomic loci of CRISPR-Cas in Enterococcus faecalis. In this study, we aimed to assess correlation of the CRISPR-Cas system distribution with the acquisition of antibiotic resistance among E. faecalis isolates. A total of 151 isolates of E. faecalis were collected from urinary tract infections (UTI) and dental-root canal (DRC). All isolates were screened for phenotypic antibiotic resistance. In addition, antibiotic resistance genes and CRISPR loci were screened by using polymerase chain reaction. Genomic background of the isolates was identified by random amplified polymorphic DNA (RAPD)-PCR. The number of multidrug-resistant E. faecalis strains were higher in UTI isolates than in DRC isolates. RAPD-PCR confirmed that genomic background was diverse in UTI and DRC isolates used in this study. CRISPR loci were highly accumulated in gentamycin-, teicoplanin-, erythromycin-, and tetracycline-susceptible strains. In concordance with drug susceptibility, smaller number of CRISPR loci were identified in vanA, tetM, ermB, aac6'-aph(2"), aadE, and ant(6) positive strains. These data indicate a negative correlation between CRISPR-cas loci and antibiotic resistance, as well as, carriage of antibiotic resistant genes in both of UTI and DRC isolates.

Brain Abscess Due to Dental Sinusitis: A Case Report on Incomplete Infection Defense Associated With a Post-Fusion Linear Skull Fracture.

Brain abscess is a pyogenic disease secondary to a bacterial, tuberculous, or fungal infection of the brain; thus, early detection and treatment are of crucial importance. Herein, we present a case of a brain abscess arising from dental sinusitis due to an incomplete infection defense mechanism linked to a post-fusion linear skull fracture. The patient initially presented with a persistent headache, which was diagnosed as frontal sinusitis. Consequently, antibiotic treatment was started. However, due to a refractory response to antibiotics, MRI was performed, which revealed a brain abscess in the frontal lobe adjacent to the right frontal sinus measuring 40 mm in diameter. This abscess was surgically drained and cultured. Initially, the patient was treated with three antibiotics, which were eventually de-escalated. The cultures revealed nasal commensal bacteria, suggesting a direct spillover from sinusitis leading to a brain abscess. A tooth with root inflammation, which had been left untreated and resulted in bone melting of the maxillary sinus wall, was extracted. After more than eight weeks of antimicrobial therapy, improvement in the clinical and imaging findings was noted, and the patient was discharged. Brain abscesses may develop from sinusitis even after linear fractures have healed due to a continued incomplete infection defense mechanism. Moreover, root and sinus infections should undergo evaluation, including the upper dental crown using coronal computed tomography, and treatment should be initiated promptly.

Detection of periodontal bacteria in thrombi of patients with acute myocardial infarction by polymerase chain reaction.

BACKGROUNDS: Numerous reports have demonstrated that periodontal bacteria are present in plaques from atherosclerotic arteries. Although periodontitis has recently been recognized as a risk factor for coronary artery disease, the direct relationship between periodontal bacteria and coronary artery disease has not yet been clarified. It has been suggested that these bacteria might contribute to inflammation and plaque instability. We assumed that if periodontal bacteria induce inflammation of plaque, the bacteria would be released into the bloodstream when vulnerable plaque ruptures. To determine whether periodontal bacteria are present in thrombi at the site of acute myocardial infarction, we tried to detect periodontal bacteria in thrombi of patients with acute myocardial infarction by polymerase chain reaction (PCR). METHODS: We studied 81 consecutive adults with ST-segment elevation acute myocardial infarction who underwent primary percutaneous coronary intervention (PCI). All patients underwent removal of thrombus with aspiration catheters at the beginning of percutaneous coronary intervention, and a small sample of thrombus was obtained for PCR. RESULTS: The detection rates of periodontal bacteria by PCR were 19.7% for Aggregatibacter actinomycetemcomitans, 3.4% for Porphyromonas gingivalis, and 2.3% for Treponema denticola. CONCLUSIONS: Three species of periodontal bacteria were detected in the thrombi of patients with acute myocardial infarction. This raises the possibility that such bacteria are latently present in plaque and also suggests that these bacteria might have a role in plaque inflammation and instability.

Two patients requiring surgical management for leakage of calcium hydroxide paste from root canal into infraorbital space.

Two patients requiring surgical management for leakage of calcium hydroxide paste from a root canal into the infraorbital space are reported. A paste root canal treatment material used at the time of maxillary root canal treatment had leaked out of the root canal in both patients. Computed tomography confirmed displacement of the root canal treatment material into the soft tissue, with extension into the infraorbital space. In both cases, foreign body removal was performed. Root canal treatment using a calcium hydroxide paste should be performed carefully without strong pressure.

A Case of a Stafne Bone Defect Associated with Sublingual Glands in the Lingual Side of the Mandible.

A Stafne bone defect from the mandibular anterior to the premolar region is an extremely rare case. A case of a Stafne bone defect extending from the mandibular anterior to the premolar region was presented. Computed tomography (CT) and magnetic resonance imaging (MRI) suggested that salivary gland tissue connected to the sublingual glands was involved in the formation of the cavity. The patient was a 68-year-old man who was examined at our hospital's emergency outpatient department after a traffic accident. He was referred to our department for the treatment of contusions of the lips and oral cavity. A bone defect in the lingual side of the mandible from the right anterior to the right premolar region was incidentally detected on CT. CT showed a rounded cavity in the lingual side of the mandible that had a lingual opening, was monocystic, and had a cortical margin. The margin of the cavity was relatively dull and regular. MRI showed that the tissue filling the cavity in the lingual side of the mandible had similar signal intensity as the sublingual glands and was contiguous with the normal sublingual glands. Based on these findings, the bone defect was diagnosed as a Stafne bone defect filled with salivary gland tissue connected to the sublingual gland tissue.

Long-term pegylated interferon monotherapy following 72 weeks of pegylated interferon and ribavirin in hepatitis C virus genotype-1-infected slow responders.

OBJECTIVE: Slow responders to pegylated interferon (Peg-IFN) and ribavirin (RBV) among patients infected with hepatitis C virus (HCV) genotype 1 may benefit from an extended treatment course. The aim of this study was to determine the efficacy of persistent negative serum HCV RNA over 96 weeks during long-term Peg-IFN monotherapy following 72 weeks of combination therapy. METHODS: A total of 46 HCV genotype 1-infected slow responders were treated for 72 weeks with Peg-IFN and RBV combination therapy alone (n=25) or additional long-term biweekly treatment with 90 µg of Peg-IFN-α2a (n=21). The criterion for the completion of long-term Peg-IFN monotherapy was defined as the attainment of constantly negative HCV RNA in the serum over 96 weeks during IFN treatment. RESULTS: The patients with sustained negative serum HCV RNA during 96 weeks of IFN treatment had a higher rate of sustained virological response (SVR) than those without (81 vs. 40%, p=0.012). A multivariate analysis identified sustained negativity of serum HCV RNA over 96 weeks of IFN treatment to be a predictive factor for SVR. CONCLUSION: In the present study, sustained negative serum HCV RNA over 96 weeks during long-term Peg-IFN monotherapy following 72 weeks of combination therapy of Peg-IFN and RBV resulted in beneficial virological outcomes among HCV genotype 1-infected slow responders.