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Kunitomo Watanabe

Publications and source records attributed to Kunitomo Watanabe.

At least 19 recordsLinked to original sources

[Topics on anaerobic bacteria and anaerobic infection].

Considerable information has been accumulated in the field of anaerobic bacteria and anaerobic infections in the last ten years. Here we tried to briefly introduce several selected topics of clinical importance in this field: Proposal of the term "Nanaerobe", Changes of classification and nomenclature of anaerobes, Anaerobic bacteremia, Lemierre's syndrome as a revival anaerobic infection, Atopobium vaginae as Bacterial Vaginosis-associated bacteria, and new actions of the Clostridium perfringens toxins.

Bacteria, Anaerobic↗

In vitro antianaerobic activity of DX-619, a new des-fluoro(6) quinolone.

The in vitro activity of DX-619, a new des-F(6) quinolone, against anaerobic bacteria was evaluated. DX-619 showed potent activity against Bacteroides, Prevotella, Fusobacterium, Micromonas, Actinomyces, and Clostridium spp., with MIC(50)s/MIC(90)s of </=0.03 to 0.25/</=0.03 to 1 microg/ml, respectively. DX-619 was also active against imipenem-resistant Bacteroides spp., with MIC(50)s/MIC(90)s of 0.25/1 microg/ml, respectively.

Anti-Bacterial Agents↗

[Prevalence and treatment of pharyngeal Chlamydia trachomatis infections].

In recent years, the number of the patients with pharyngeal infection caused by Chlamydia trachomatis is believed to be on the rise due to diversification in sexual behaviors. In addition, pharyngeal infection by C. trachomatis is often asymptomatic, and this is also believed to be a major factor for the increase of the disease. In this study, we conducted a survey among general females and commercial sex workers (CSWs) to study their sexual behavior and prevalence of chlamydial infections (in uterine cervix and pharynx). The results showed that orogenital contact has become a common act, even for general females. Chlamydial infections of uterine cervix were found in 33.3% and 7.9% of CSWs and general females, respectively. Chlamydial infections of pharynx were found in 22.5% and 5.2% of CSWs and general females, respectively. The evaluation of treatments of these infections with clarithromycin, levofloxacin, and azithromycin showed that 7, 10, and 14 days administrations of 400 mg clarithromycin, 7, 10, and 14 days administrations of 300 mg levofloxacin, and a single dose of 1000 mg of azithromycin, would eradicate 100% of C. trachomatis for infections of uterine cervix. For pharyngeal infections, 10 and 14 days administrations of clarithromycin and levofloxacin were shown to eradicate 100% of C. trachomatis. However, the eradication rates for 7 days administrations of clarithromycin and levofloxacin were 83.9% and 86.2%, respectively, and the rate for a single dose of azithromycin was 85.0%. From these results, it was thought that more than 10 days of administrations of clarithromycin or fluoroquinolone antibacterial agents such as levofloxacin are necessary to treat pharyngeal chlamydial infection. Clinical significance of pharyngeal chlamydial infection is still not clear; however, this study have shown the need for more detailed investigations using culture assay, in corporation with doctors in otolaryngology and internal medicine.

Adult↗

[Sensitivity surveillance of Streptococcus pneumoniae isolates for several antibiotics in Gifu prefecture (2004)].

We analyzed Streptococcus pneumoniae isolates in Gifu prefecture between November 2004 and December 2004. We analyzed isolates of 160 strains from 8 medical facilities to determine antibiotic susceptibility, genotype of penicillin-binding protein (PBP) genes and macrolide resistant genes, and the serotypes of penicillin-resistant S. pneumoniae (PRSP). When referred to the classification in CLSI (formerly NCCLS), the overall incidence of penicillin-susceptible (PSSP), penicillin-intermediate (PISP) and penicillin-resistant (PRSP) were 48 (30.0%), 81 (50.6%) and 31 (19.4%) strains, respectively, and the susceptibility distribution to benzylpenicillin showed triplet peaks. The incidence of PISP and PRSP was higher in the material of throat and nasal cavity, and area of Chuno and Gifu district. The sum of the incidence of PISP and PRSP was slightly higher in inpatient-derived stains than outpatient-derived strains. The incidence that didn't possess mutations in PBP genes and macrolide-resistant genes was 6 (3.75%) and the others 154 strain (96.25%) had abnormal PBP genes or macrolide-resistant genes. The 90% of pneumococcal serotypes of PRSP 31 strains were serotype 6 (14 strains, 45.2%), 19 (7 strains, 22.6%) and 23 (7 strains, 22.6%). The MIC90 of each antibiotics was as follows; 0.1 microg/mL for panipenem, 0.2 microg/mL for imipenem and tosufloxacin, 0.39 microg/mL for meropenem and gatifloxacin, 0.78 microg/mL for amoxicillin, cefteram and cefditoren, 1.56 microg/mL for piperacillin, cefcapene and levofloxacin, 3.13 microg/mL for flomoxef, 6.25 microg/mL for cefdinir and cefotiam, 12.5 microg/mL for norfloxacin and minocycline, 25 microg/mL for cefixime, and 100 microg/mL for clarithromycin.

Anti-Bacterial Agents↗

[Surveillance on Pseudomonas aeruginosa isolated in Gifu prefecture (2004)].

We analyzed Pseudomonas aeruginosa isolates in Gifu prefecture between September and October 2004. We conducted antimicrobial susceptibility test for 266 strains isolated from 8 medical institutes and 1 clinical laboratory, based on broth microdilution method. The MIC50 and MIC90 of piperacillin, amikacin, imipenem, and ciprofloxacin were 4 and 64, 4 and 8, 1 and 16, 0.25 and 8 microg/mL, respectively. The strains isolated from urine had higher MIC level in comparison with from sputum, which was remarkable in penicillins, cephalosporins and fluoroquinolones. We isolated 7 strains of multi-drug resistant Pseudomonas aeruginosa (MDRP), in which 3 strains showed under 16 microg/mL in MIC against anti-MRSA (methicillin-resistant Staphylococcus aureus) drug arbekacin. Continuous surveillance would be needed for antimicrobial resistance on P. aeruginosa in Gifu prefecture.

Drug Resistance, Bacterial↗

[Clinical investigation on administration method of gatifloxacin based on PK/PD theory].

There have not been sufficient clinical studies based on pharmacokinetics/pharmacodynamics (PK/PD) theory, on which many clinical doctors have recently focused. To consider the optimized administration method based on PK/PD theory for gatifloxacin (GFLX), which was one of the oral fluoroquinolone antibacterial, we influenzae investigated clinical efficacies and adverse events for pelvic inflammatory disease (PID) in giving GFLX daily 400 mg divided twice a day or four times a day. The number of leukocyte and the value of CRP were significantly reduced by chemotherapy in twice a day group, compared with four times a day group. We were able to measure the blood level in 4 cases. The AUC/MIC values for presumption causative bacteria (causative bacteria in both cases: Escherichia coli) in cured patients were 142.28 and 280.16, however, in therapy-failed patients, the AUC/MIC value to presumption causative bacterium were 4.10 (causative bacteria: Prevotella bivia) and 4.35 (causative bacteria: Pseudomonas aeruginosa). These results suggested the importance of the therapeutic method based on PK/PD theory.

Anti-Infective Agents↗

Efficacy of micafungin against deep-seated candidiasis in cyclophosphamide-induced immunosuppressed mice.

OBJECTIVES: We investigated the effects of fluconazole and micafungin for the therapy of deep-seated candidiasis in a cyclophosphamide-induced immunosuppressed mouse model. METHODS: We used the experimental model of intraperitoneal fungal abscess caused by Candida albicans, as described previously. RESULTS AND CONCLUSIONS: Micafungin efficacy was equal to that of fluconazole in one-tenth dosage even in peritonitis. We also assessed the short-term (24 h) and long-term (8 days) therapeutic effects after the end of therapy. Although the therapeutic effect of fluconazole was similar to that of micafungin at 24 h after the end of therapy, the effect of micafungin was superior to that of fluconazole at 8 days after the end of therapy.

Animals↗

Dual role of vitamin C in an oxygen-sensitive system: discrepancy between DNA damage and cell death.

Although vitamin C is considered to act both as pro-oxidant and antioxidant, the mechanisms underlying these actions are still unclear. Using the oxygen-sensitive system of a strict anaerobe, Prevotella melaninogenica, we investigated both the pro-oxidant and antioxidant mechanisms of vitamin C. In the presence of vitamin C, the 8-hydroxydeoxyguanosine (8OHdG) formation induced by oxygen exposure was enhanced, probably due to the action of vitamin C on hydrogen peroxide generated during oxygen exposure: while catalase almost completely suppressed the enhancing effect of vitamin C, 8OHdG formation induced by hydrogen peroxide was enhanced by vitamin C. By contrast, the presence of vitamin C inhibited bacterial cell death, membrane damage, and lipid peroxidation induced by oxygen exposure. Sodium azide showed similar effects to vitamin C, thus the antioxidant action of vitamin C may be due to its quenching of the singlet oxygen generated in this system. Both the pro-oxidant and antioxidant effects of vitamin C were observed only in acidic conditions.

8-Hydroxy-2'-Deoxyguanosine↗

Microbiology of Bartholin's gland abscess in Japan.

This study was conducted to determine the current epidemiology concerning the causative organisms for Bartholin's gland abscess in Japan. Microbiological examination of 224 cases showed positive results in 219 cases and negative results in 5 cases. Of all of the bacterial isolates, 307 and 118 were aerobes and anaerobes, respectively. The most frequently isolated bacterium was Escherichia coli. Of the anaerobes, the most frequently isolated organism was Bacteroides species, followed by Prevotella species. The organisms related to respiratory infectious diseases, such as Streptococcus pneumoniae and Haemophilus influenzae, including resistant bacteria, were sometimes involved between 2000 and 2004.

Abscess↗

Propionibacterium acnes is the most common bacterium commensal in peripheral lung tissue and mediastinal lymph nodes from subjects without sarcoidosis.

BACKGROUND: In studies of the unknown etiology of sarcoidosis, Propionibacterium acnes (a possible agent) was found in the lungs and lymph nodes of many sarcoidosis patients and some control subjects. P. acnes might be commensal not only to the skin, conjunctivae, and intestine, but also to the lungs and lymph nodes of individuals without sarcoidosis. METHODS: We cultured peripheral lung tissue and various lymph nodes obtained from patients with diseases other than sarcoidosis. DNA of 45 isolates of P. acnes from these patients, 67 isolates from normal skin, conjunctiva, and intestine, and 39 isolates from sarcoid lymph nodes were compared by random amplified polymorphic DNA analysis. RESULTS: P. acnes was isolated from half of 43 lungs and 8 of 11 mediastinal lymph nodes, mostly in pure culture. P. acnes was isolated from half of 20 gastric and 3 of 12 intestinal lymph nodes; intestinal bacteria were also numerous. In general, fewer than 500 colony-forming units of P. acnes per gram tissue were isolated, but 4 lung tissue specimens, 2 of which had a few granulomas, had many more. P. acnes strains from a particular site (lung, lymph node, skin or conjunctivae, and intestine) were genetically similar, more than isolates obtained from different sites. Lymph-node isolates from subjects with and without sarcoidosis differed little. CONCLUSION: These results suggest that P. acnes normally resides in peripheral lung tissue and mediastinal lymph nodes and that the strains of P. acnes isolated from sarcoid lymph nodes were not specific to sarcoidosis.

Adult↗

[Surveillance based on molecular epidemiology for Haemophilus influenzae Isolates in Gifu Prefecture].

We analyzed Haemophilus influenzae isolates in Gifu prefecture between May 2003 and August 2003. We conducted molecular-level epidemiological studies for 313 strains using PCR to identify resistant genes in H. influenzae. Our four sets of primers are as follows: (i) p6 gene of P6 membrane protein, (ii) TEM-1 type beta-lactamase gene (bla), (iii) normal PBP 3 gene (ftsl), and (iv) mutational ftsl gene detected in beta-lactamase-nonproducing ampicillin (ABPC) resistant H. influenzae (BLNAR). H. influenzae strains were classified into 6 types based on PCR: (i) beta-lactamase-nonproducing ABPC-susceptible strains (BLNAS; n = 85) with no any resistant genes, (ii) TEM-1 type beta-lactamase-producing ABPC resistant strains (BLPAR; n = 6), (iii) beta-lactamase-nonproducing and low-level ABPC-resistant strains (Low-BLNAR; n = 77) possessing Asn-526 --> Lys-526 amino acid substitution, (iv) BLNAR strains (n = 138) possessing Asn-526 --> Lys-526 and 3 amino acids substitutions detected around the Ser-Ser-Asn conserved motif, (v) beta-lactamase-producing amoxicillin-clavulanate resistant strains (BLPACR-I; n = 3) possessing TEM-1 and Low-BLNAR resistant genes, and (vi) beta-lactamase-producing amoxicillin-clavulanate resistant strains (BLPACR-II; n = 4) possessing TEM-1 and BLNAR resistant genes. Amoxicillin (AMPC) MIC90s in Low-BLNAR was 4 microg/mL and in BLNAR was 16 microg/mL. In oral cephalosporins, cefditoren MIC90 was the most excellent with 0.5 microg/mL against BLNAR. The prevalence of H. influenzae type b isolates in Matsubara Otorhinolaryngology Clinic was 66.7%. Selection of appropriate antimicrobial agents should be performed to prevent resistant microorganisms. Also, the vaccination for H. influenzae type b would be strongly recommended in near future.

Adolescent↗

[Two cases of Bartholin's gland abscesses caused by Streptococcus pneumoniae and Haemophilus influenzae].

Most of Bartholin's gland abscesses have been thought to be caused by microorganisms found in opportunistic infections. However, we have encountered two very interesting cases of Bartholin's gland abscesses caused by Streptococcus pneumoniae and Haemophilus influenzae, two major pathogens of respiratory tract infections. In the first case, since abscess formation was not observed due to disintegration, cefdinir (CFDN), 300 mg/day, t.i.d. for 5 days was administered. The treatment improved clinical symptoms, but relapse occurred 3 days after the administration was discontinued. Microbiological examination of pus revealed the presence of Streptococcus pneumoniae and Finegoldia magna, and it also showed that the isolated S. pneumoniae was penicillin-resistant S. pneumoniae (PRSP). After an incision and drainage of abscess, cefteram pivoxil (CFTM-PI), 300 mg/day t.i.d. for 7 days, was administered, and the cure was confirmed. In the second case, after an incision and drainage of Bartholin's gland abscess, amoxicillin (AMPC), 750 mg/day, t.i.d. for 5 days, was administered. The treatment improved clinical symptoms temporarily. However, the symptoms deteriorated 7 days after the operation, and the patient was diagnosed with relapse. Microbiological examination of pus revealed the presence of Haemophilus influenzae and Peptostreptococcus anaerobius, and it also showed that the isolated H. influenzae was beta-lactamase-nonproducing ampicillin-resistant H. influenzae (BLNAR). After performing additional incision and drainage of abscess again, CFTM-PI, 300 mg/day, t.i.d. for 7 days, was administered, and the cure was confirmed. In addition, the analysis of these two cases using PK/PD theory revealed that the time above MIC reached 100% with administration of CFTM-PI 300mg, t.i.d. suggesting that the dosage is sufficient for treating these infections. There are other cases of external genitalia infections caused by microorganisms usually associated with respiratory tract infections like cases that we are reporting here. Therefore, it is necessary to consider a possible infection by drug-resistant bacteria even for a case of external genitalia infection. In addition, it was thought that adjusting dosage and method for administration of antibacterial agents based on PK/PD theory would help to rovide efficient treatment.

Abscess↗

[Epidemiology of Streptococcus pneumoniae isolates in Gifu Prefecture].

We analyzed Streptococcus pneumoniae isolates confirmed by direct PCR in Gifu prefecture between May 2002 and August 2002. We analyzed isolates of 254 strains from 6 hospitals to determine antibiotic susceptibility, genotype of penicillin-binding protein (PBP) genes and macrolide resistant genes, and the serotypes distribution of isolates from Matsubara Otorhinolaryngology Clinic. Isolates in which abnormal PBP genes of pbp1a, pbp2x, and pbp2b were identified by PCR were classified based on PCR results as follows; (i) penicillin-susceptible (PSSP) with 3 normal PBP genes, (ii) penicillin-intermediate (PISP) with an abnormal pbp2x, (iii) PISP with an abnormal php2b, (iv) PISP with abnormal pbp2x and pbp2b, (v) PISP with abnormal pbpla and pbp2x, (vi) penicillin-resistant (PRSP) with 3 abnormal PBP genes. The overall incidence of PRSP, PISP and PSSP was 121 (49%), 109 (42%) and 24 (9%), respectively, and there was a significant difference among some hospitals (p<0.05). However, there was no significant difference among the hospitals for the incidence of abnormal macrolide-resistant genes (mefA, ermB). Panipenem showed an excellent antimicrobial activity for injectable carbapenems against PRSP, following biapenem, imipenem, and meropenem. Cefditoren (CDTR) showed an excellent antimicrobial activity for oral cephalosporins against PRSP, following cefteram and cefcapene. Interestingly, there were 2 and 3 strains on MIC of CDTR for 8 and 4 microg/mL, respectively. The prevalent pneumococcal serotypes of isolates in Matsubara Clinic were 6 (17/55), following by 40 (8/55), 9 (6/5) and 15 (5/55). The endemic strains were observed in this study using pulsed field gel electrophoresis. These findings suggest the needs to continue the surveillance of bacterial resistance not only in the nationwide but also in the distict.

Drug Resistance, Bacterial↗

[Incidence, treatment and outcome of anaerobic bacteremia].

In this paper, we discussed the incidence and clinical significance of blood cultures positive for anaerobes. Anaerobic bacteria is uncommon, accounting for 0.5-13% of all positive cultures. The incidence depend on the institution. Recent findings of a multicenter prospective observational trials showed that in vitro activity of the agents directed at Bacteroides species reliably predicts outcome. When a positive anaerobic blood culture was noted, appropriate action must be taken, since negligence in this respect may seriously impair the outcome of patients.

Bacteremia↗

[Recovery of facultatives and anaerobes from frozen specimens with a polymicrobial nature].

Microbiological examination of frozen specimens is sometimes carried out in clinical microbiology and the result is used as an aid of diagnosis and/or treatment of polymicrobial infections. The study was carried out to reevaluate the merit of freezing specimens in clinical microbiology. A total of 10 specimens with a polymicrobial nature were included in this study. Before and after freezing specimens, we isolated facultative and anaerobic bacteria using a set of primary isolation media, consisting of three aerobic agar plates (MacConkey agar, blood agar and chocolate agar) and four pre-reduced anaerobic agar plates (HK Blood agar, HK blood agar with paromomycin (PM) and vancomycin (VM), phenyl ethyl-alcohol (PEA) agar and Bacteroides bile esculin (BBE) agar). All the procedures were done in a properly controlled anaerobic chamber. The number of isolates before and after freezing was 79 and 70, respectively. Among the strains isolated before freezing, 33 strains were recovered on the same kin of media artery freezing, without a remarkable decrease in the quantity. But 26 strains were not recovered and 2 strains were recovered with a remarkable decrease. Among 26 strains, 15 strains could be successfully backed up on the different kind of media. In conclusion, an anaerobic technique with an anaerobic chamber and a set of isolatin plates including blood agar, chocolate agar, HK blood agar, PEA blood agar, HK blood agar with PM and VM enable us to estimate the bacteriology before freezing from frozen specimens.

Bacteria, Anaerobic↗