We studied the prevention of bacterial endocarditis, i. e., lowering the incidence of transient bacteremia by administering antibiotics prior to tooth extractions. In the U. S., the American Heart Association (AHA) publicly announced in 1977 a regimen of preventive administration. The latest was published in the JAMA (1997). The regimen recommends the administration of antibiotics by venous infusion to high-risk patients and oral administration to moderate-risk patients. Our was to determine form a regimen more suitable to the Japanese than the AHA's as a guide to dental practitioners for chemoprophylaxis for moderate-risk patients in oral antibiotics administration.
(1) Healthy patients.
Subjects were the 47 volunteers from among doctors and nurses who work for the Tokai University. They had venous blood (15 mL) taken immediately after tooth extraction without antibiotics administration. The positive rate of blood culture was 69.2%(35/47). Streptococcus milleri and Peptostreptococci were the top 2 strains detected.
(2) High-risk patients
Subjects had a history of valve replacement or bacterial endocarditis. They were administered antibiotics by venous infusion prior to tooth extractions. Cases numbered 236 patients and 8 antibiotic agents were tested. Carbapenems showed the lowest positive rate.
(3) Moderate-risk patients
We tested 4 commercially available antibiotics for oral administration obtained easily in Japanamoxicillin, faropenem, cefterampivoxil, and clarithromycin. Cases numbered 60 cases of amoxillin (500mg/dose), 45 for faropenem (400mg/dose), 14 for cefteram pivoxil (300mg/dose), and 16 for clarithromycin (600mg/dose). Amoxillin showed the lowest positive rate of 26.7%(16/60), followed by faropenem. Our recommendation based on the above experiment is that to lower the positive rate of blood culture after tooth extraction, dental practitioners should administer 500mg of amoxillin 61 minutes to 110 minutes before tooth extraction or 400mg of faropenem 70 minutes to 120 minutes before they start treatment.

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Our study was to evaluate a VITEK 2 system to determine antimicrobial susceptibility in clinical isolates. The 434 strains tested consisted of 111 Staphylococcus aureus (MRSA, MSSA), 108 Enterococcus, 113 Streptococcus pneumoniae (PSSP, PISP, PRSP), and 102 Pseudomonas aeruginosa. Antimicrobial- susceptibility tests were evaluated by comparing the VITEK 2 system to S, I, and R categories determined by agar dilution following the standard method of the Japan Society of Chemotherapy. Similar results were obtained for MRSA by both methods wherein approximately 40% of tested strains were resistant to gentamicin (GM) and 70% to ofloxacin (OFLX), while all were susceptible to vancomycin (VCM) and sulfamethoxazole-trimethoprim (ST). With PISP, PRSP agar dilution, approximately 20% of ceftriaxone (CTRX) and cefotaxime (CTX) and 66% of imipenem (IPM) were determined to be “I”, The susceptibility result for CTRX obtained by the VITEK 2 system agreed well with that obtained by agar dilution. The VITEK 2 system determined 64% as “I” for CTX and all strains as “S” for IPM, showing a tendency for CTXto be resistant and IPM to be susceptible compared to agar dilution. For Enterococcus, many penicillin G (PCG)-resistant strains were seen in Enterococcus faecium. Enterococcus faecalis and Enterococcus faecium determined as VCM-resistant by agar dilution showed the same results as for the VITEK 2 system. For ceftazidime (CAZ)-resistant P. aeruginosa, many strains were resistant to β-lactams, including piperacillin (PIPC) and cefpirome, but were susceptible to quinolones such as ciprofloxacin and levofloxacin. Approximately 70% of IPM-resistant strains were susceptible to PIPC and CAZ, and about half were resistant to quinolones. Results obtained by agar dilution and the VITEK 2 system thus agreed closely. In conclusion, these results demonstrate that VITEK 2 system performance is equivalent to agar dilution MIC reference and useful in routine clinical microbiology laboratory procedures.

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Candida species are reported to be one of the major pathogens in serious infectious problems in the surgical treatment of cancer patients. Candidemia is diagnosed by blood culture, β-D-glucan, and Candida antigen assay in Japan. However, these methods are not satisfied in the view points of confidence and quickness. The polymerase chain reaction (PCR) has been applied to diagnose fungal infections. Candida-specific PCR was developed to detect fungi, especially medically important Candida sp., and proved to be clinically more reliable than conventional methods. However Candida-specific PCR provided only nonquantitative results and it was difficult to diagnose fungemia more precisely. Therefore, the present syudy was designed to investigate the real-time quantitative PCR for diagnosis and qantitative analysis of candidiasis. The Candida albicans-secreted aspartic proteinase (SAP) gene was used as the specific primer pair of in quantitative PCR. A specific fluorogenic probe was designed between the sequence of the specific primer pair of SAP genes. Real-time detection of the specific fluorescent signal in each PCR cycle indicated an essential information to quantify the number of C. albicans. This method was evaluated using human whole blood mixed with different numbers of C.albicans isolates. Almost no difference was seen between measured numbers analyzed within 4.5 hours and actual numbers. Furthermore, the present syudy was designed to investigate the nested PCR for identification of clinically important C.albicans, Candida tropicalis, Candida parapsilosis, Candida glabrata and Candida krusei, and it was successfully established in candidemia. Each specific nested primer pair was designed to identify individual fungi, between the sequence of the specific primer pair of the first PCR for the V 4 region of the 18 S ribosomal RNA gene of Candida sp. Our quantitative determination of C. albicans using real-time PCR and identification of Candida sp. by nested PCR were confirmed to be applicable to fungemia and able to diagnose easily and sensitively quantify C. albicans or identify Candida sp. from blood in a short time.

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A 56-year-old man with poorly controlled diabetes mellitus contracted buccal cellulitis due to pericoronitis of the right upper third molar. His blood suger was 554mg/dL, and Hb_A1 12.2%. He immediately underwent surgical drainage and tooth extraction and received panipem/betamipron (PAPM), clindamycin (CLDM) and γ-globulin. The postoperative course was uneventful, and no recurrence was observed. Streptococcus constellatus, Klebsiella pneumoniae, Peptostreptococcus Propionibacterium and anaerobic gram-positive rod, (ANGPR) were isolated from pus.
Bacteriological examination in odontogenic infections.
We indentified 219 strains of causative organisms in 51 cases of odontogenic infection. Of these, aerobic strains numbered 93 (42%) and anaerobic 126 (58%). Prevotella and Porphyromonas were most frequent among anaerobic bacteria, whereas oral streptococci were most frequent isolates among aerobic bacteria. Faropenem (FRPM) showed greater antibacterial activity against Streptococcus mitis, than cefditoren, ampicillin, flomoxef, levofroxacin, clarithromaycin or azithromycin.

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The bactricidal activity of benzalconium chloride (BAC), chlorhexidine (CHG). popidone iodine (PVPI) and alkyldiaminoethylglycine hydrochloride (AEG) on methicillin-resistant Staphylococcus aureus (MRSA, 10 clinical isolates) and Psudomonas aeruginosa (6 clinical isolates) was evaluated by the microplate method. And the effect of organic substances (3% yeast) on the bactericidal activity of these disinfectants was examined. All disinfectants showed excellent bactericidal activity on floating MRSA and P. aeruginosa. The bactricidal activity of PVP-I on MRSA and that of CHG on MRSA and P. aeruginosa were weaker than other disinfectants in lower concentrations. All of four disinfectants showed weaker bactericidal activity on adhered bacteria than on floating bacteria. Against adhered MRSA, the bactericidal activity of AEG and BAC decreased to 20-30%, and the activity of PVP-I and CHG to 30-50% of the activity against floating bacteria. As to P. aeruginosa, the bactericidal activity against adhered bacteria was weaker than that against floating bacteria. The bactreicidal activity of PVP-I and AEG in the presence of 3% yeast was decreased to 30% of the activity without yeast. In the clinical study, PVP-I had excellent eradication rate. The most common survival bacteria was Bacillus.

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Between January 2000 and October 2000, we clinically evaluated 30 patients with lower respiratory infection due to Streptococcus pneumoniae and/or Haemophilus influenzae orally administered 9mg/kg/day of cefditoren pivoxil (CDTR-PI) or 15mg/kg/day of faropenem (FRPM). Patients ranged from 6 months to 5 years of age. No significant difference was seen in background patient profiles between groups. Clinical efficacy was 86.7% in the CDTR-PI group and 80.0% in the FRPM group. Clinical efficacy by pathogeic organism was 100%(CDTR-PI group) vs 63.6%(FRPM group) in H. influenzae, 75.0% vs 100 % in penicillin-resistant S. pneumoniae (PRSP), 50.0% vs 100% in penicillin-susceptible S. pneumoniae (PSSP), 100% vs 87.5% in H. influenzae and PRSP, and 50.0% vs 66.7% in H. influenzae and PSSP. Bacteriological efficacy was 50.0 vs 22.7% in H. influenzae, 18.8% and 46.2% in PRSP, and 25.0% vs 66.7 % in PSSP. Diarrhea was observed in 10.0% in the CDTR-PI group and in 13.3% in the FRPM group. No significant difference was seen between groups in clinical evaluation.

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