Antimicrobial susceptibility surveillance of bacterial isolates recovered in Japan from odontogenic infections in 2013.

We report on the findings of the first antimicrobial susceptibility surveillance study in Japan of isolates recovered from odontogenic infections. Of the 38 facilities where patients representing the 4 groups of odontogenic infections were seen, 102 samples were collected from cases of periodontitis (group 1), 6 samples from pericoronitis (group 2), 84 samples from jaw inflammation (group 3) and 54 samples from phlegmon of the jaw bone area (group 4) for a total of 246 samples. The positivity rates of bacterial growth on culture were 85.3%, 100%, 84% and 88.9%, respectively, for groups 1, 2, 3 and 4. Streptococcus spp. isolation rates according to odontogenic infection group were 22% (group 1), 17.7% (group 3) and 20.7% (group 4). Anaerobic isolation rates were 66.9% (group 1), 71.8% (group 3) and 68.2% (group 4). Drug susceptibility tests were performed on 726 strains excluding 121 strains that were undergrown. The breakdown of the strains subjected to testing was 186 Streptococcus spp., 179 anaerobic gram-positive cocci, 246 Prevotella spp., 27 Porphyromonas spp., and 88 Fusobacterium spp. The isolates were tested against 30 antimicrobial agents. Sensitivities to penicillins and cephems were good except for Prevotella spp. The low sensitivities of Prevotella spp is due to ß-lactamase production. Prevotella strains resistant to macrolides, quinolones, and clindamycin were found. No strains resistant to carbapenems or penems were found among all strains tested. No anaerobic bacterial strain was resistant to metronidazole. Antimicrobial susceptibility testing performed on the S. anginosus group and anaerobic bacteria, which are the major pathogens associated with odontogenic infections, showed low MIC90 values to the penicillins which are the first-line antimicrobial agents for odontogenic infections; however, for Prevotella spp., penicillins combined with ß-lactamase inhibitor showed low MIC90 values.

Giant Cell Tumor of the Skull: Review of the Literature.

BACKGROUND: Giant cell tumors (GCTs) are rare in the skull. The present report describes a case with a primary GCT located in the temporal bone and reviews the relevant literature. We also propose a treatment strategy for GCT of the skull. CLINICAL PRESENTATION: A 41-year-old man presented with headache and auditory disturbance. Radiologic images showed a lytic expansive extradural lesion originating primarily from the right temporal bone and expanding into the middle cranial fossa and the infratemporal fossa. A biopsy specimen of the lesion was obtained from the external auditory meatus. Total removal was performed with temporal craniectomy, mandibular condylar process removal, tympanoplasty, and mastoidectomy. DISCUSSION: The rate of recurrence of GCTs is related to complete resection and location of the GCT rather than to the degree of invasiveness. Some of the mononuclear cells and stromal cells in GCT express receptor activator of nuclear factor κ-ß ligand (RANKL). Because inhibition of RANKL and bisphosphonate therapy might eliminate giant cells, this approach might be useful for recurrent or unresectable GCTs of the skull. CONCLUSIONS: Preoperative diagnosis by biopsy is important in determining the therapeutic strategy of GCTs. Complete resection is important to reduce the recurrence rate of GCTs in the skull.

[In vitro susceptibilities to levofloxacin and various antibacterial agents of 12,919 clinical isolates obtained from 72 centers in 2007].

We have reported in this journal in vitro susceptibilities of clinical isolates to antibiotics every year since 1992. In this paper, we report the results of an analysis of in vitro susceptibilities of 12,919 clinical isolates from 72 centers in Japan to selected antibiotics in 2007 compared with the results from previous years. The common respiratory pathogens, Streptococcus pyogenes, Streptococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenzae maintained a high susceptibility to fluoroquinolones (FQs). The resistance of S. pyogenes to macrolides has been increasing every year and this was especially clear this year. Most strains of Enterobacteriaceae except for Escherichia coli showed a high susceptibility to FQs. Almost 30% of E. coli strains were resistant to FQs and the resistance increased further this year. FQs resistance of methicillin-resistant Staphylococcus aureus (MRSA) was approximately 95% with the exception of 45% for sitafloxacin (STFX). FQs resistance of methicillin-susceptible S. aureus (MSSA) was low at about 10%. FQs resistance of methicillin-resistant coagulase negative Staphylococci (MRCNS) was higher than that of methicillin-susceptible coagulase negative Staphylococci (MSCNS), but it was lower than that of MRSA. However, FQs resistance of MSCNS was higher than that of MSSA. FQs resistance of Enterococcus faecalis was 22.5% to 29.6%, while that of Enterococcusfaecium was more than 85% except for STFX (58.3%). In clinical isolates of Pseudomonas aeruginosa derived from urinary tract infections, FQs resistance was 21-27%, which was higher than that of P. aeruginosa from respiratory tract infections at 13-21%, which was the same trend as in past years. Multidrug resistant strains accounted for 5.6% in the urinary tract and 1.8% in the respiratory tract. Acinetobacter spp. showed high susceptibility to FQs. The carbapenem resistant strains, which present a problem at present, accounted for 2.7%. Neisseria gonorrhoeae showed high resistance of 86-88% to FQs. The results of the present survey indicated that although methicillin-resistant Staphylococci, Enterococci, E. coli, P. aeruginosa, and N. gonorrhoeae showed resistance tendencies, and other species maintained high susceptibility rates more than 90% against FQs, which have been used clinically for over 15 years.

Histopathological variation of primary mucosa-associated lymphoid tissue lymphoma of the oral cavity.

Primary mucosa-associated lymphoid tissue (MALT) type lymphoma arising in the oral cavity is rare. We examined histopathologic, immunohistological and genotypic findings of seven cases of intraoral MALT lymphoma using formalin-fixed paraffin-embedded tissues. Histologically, two variants have been delineated. (i) In four cases of minor salivary gland type, the lymphoid follicles were surrounded by centrocyte-like (CCL) cells with occasional follicular colonization. The CCL cells invaded the residual salivary gland duct resulting in a lymphoepithelial lesion. CCL cells frequently showed plasmacytic differentiation. (ii) In three cases of follicular growth type, the lesion was characterized by follicular growth pattern resulting from prominent follicular colonization. CCL cells showed minimal plasma cell differentiation. There was no residual epithelial component detected even by cytokeratin immunostaining. There were no Epstein-Barr virus-encoded small RNA-positive cells detected by in situ hybridization. API2-MALT1 fusion transcript does not appear to be associated with either histological variant of primary intraoral MALT lymphoma.

[In-vitro susceptibilites to levofloxacin and various antibacterial agents of 18,639 clinical isolates obtained from 77 centers in 2004].

A total of 18,639 clinical isolates in 19 species collected from 77 centers during 2004 in Japan were tested for their susceptibility to fluoroquinolones (FQs) and other selected antibiotics. The common respiratory pathogens, Streptococcus pyogenes, Streptococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenzae showed a high susceptible rate against FQs. The isolation rate of beta lactamase non-producing ampicillin-resistant H. influenzae was approximately three times as large as those of western countries. Most strains of Enterobacteriaceae were also susceptible to FQs. The resistance rate of Escherichia coli against FQs has however been rapidly increasing so far as we surveyed since 1994. The FQs-resistant rate in methicillin-resistant Staphylococcus aureus (MRSA) showed approximately 90% except for 36%. of sitafloxacin while FQs-resistant rate in methicillin-susceptible S. aureus (MSSA) was around 5%. The FQs-resistant rate of methicillin-resistant coagulase negative Staphylococci (MRCNS) was also higher than that of methicillin-susceptible coagulase negative Staphylococci (MSCNS), however, it was lower than that of MRSA. In Pseudomonas aeruginosa clinical isolates, 32-34% from UTI and 15-19% of from RTI was resistant to FQs. Acinetobacter spp. showed a high susceptibility to FQs. Although FQs-resistant Neisseria gonorrhoeae have not been increased in western countries, it is remarkably high in Japan. In this survey, isolates of approximately 85% was resistant to FQs.

Progressive transformation of germinal centers: a clinicopathological study of 42 Japanese patients.

To clarify the clinicopathological features of progressive transformation of germinal center (PTGC) unrelated to nodular lymphocyte predominant Hodgkin's lymphoma in Japanese patients, we reviewed 42 cases and compared the results with those of the United States and Germany. Our results were similar to theirs, with male predominance (M/F ratio, 3:1) and the presentation of a solitary asymptomatic enlarged lymph node in the head and neck area as the common features. However, in Japan, PTGC occurs more frequently in elderly patients. In this study, 12 (29%) of the patients with PTGC were aged 60 years or more. Thirteen patients (31%) with lymphadenopathy in the neck and head area had developed localized chronic inflammation (chronic sialoadenitis=4, chronic tonsillitis=3, infectious epidermal cyst=2) or an autoimmune disorder (hyperthyroidism=2 and bronchial asthma=2). None of the patients developed a malignant lymphoma during the follow-up period of 5 to 238 months (median 27 months). Histologically, in a single longitudinal section of the lymph node, the PTGC occupied up to 5% of the total follicles in 22 patients, 5-10% in 10, 10-20% in 7, and more than 20% in 3. In 5 (12%) patients, an association with prominent marginal zone hyperplasia was also noted. This study also indicates that nodal involvement by various low-grade B-cell lymphomas exhibiting marginal zone distribution patterns should be considered as a differential diagnosis of PTGC. Moreover, in Japan, PTGC is thought to be involved in the etiology of florid reactive follicular hyperplasia in elderly patients.