Classification and antimicrobial susceptibilities of enterococcus species isolated from apparently healthy food-producing animals in Japan

A total of 1024 enterococci were recovered from faeces of healthy animals from 178 cattle, 178 pig and 156 broiler farms. Enterococcus faecium was the predominant species recovered (35.8%), followed by E. faecalis (31.3%) and E. hirae (25.6%). Oxytetracycline resistance was most frequently found among E. faecalis (85.9%), E. faecium (58.8%) and E. hirae (48.1%). Resistance rates to almost all antimicrobials were higher in E. faecalis than E. faecium and E. hirae. Isolates from cattle were more susceptible to the antimicrobials studied than those from pigs and broilers. VanA- or VanB-type vancomycin-resistant enterococci have not been found since the ban of avoparcin use 5 years ago.

Anomalous arterial supply to the gallbladder from the superior mesenteric artery: angiography and computed tomography findings in two cases

The arterial supply of the gallbladder usually arises from the right hepatic artery. Other origins include the left, proper, and common hepatic arteries. We report cases of the cystic artery arising from the superior mesenteric artery and arising from the dorsal pancreatic artery originating in turn from the superior mesenteric artery, as demonstrated by angiography and computed tomography.

[Ross procedure with aortic replacement for aortic stenosis with ascending aortic aneurysm: report of a case]

Bicuspid aortic valve (BAV) is a common congenital heart disease, and it is well known to be a risk factor for ascending aortic dilatation and dissection. We here report a case of 34-year-old woman who underwent Ross procedure with ascending aortic replacement under the diagnosis of subaortic stenosis and ascending aortic aneurysm. She was pointed out to have heart murmur soon after the birth diagnosed as patent ductus arteriosus. The ductus was ligated when she was 3-years-old, however, heart murmur remained. Further examinations revealed that she also had aortic stenosis with BAV. During her 20-year-follow-up, subaortic stenosis and ascending aorta ectasia were also progressed. Pathological examinations of resected ascending aortic wall showed mucoid degeneration and laceration of collagen fibers, suggesting the fragility of dilated aortic wall with BAV.

High production of beta-thujaplicin glycosides by immobilized plant cells of Nicotiana tabacum

beta-Thujaplicin (hinokitiol) is a tropolone derivative present in the heartwood of cupressaceous plants and is used as a medicine, a food additive, and a preservative, and in cosmetics as hair tonic. The cultured plant cells of Nicotiana tabacum glycosylated beta-thujaplicin to two glucosides, 4-isopropyltropolone 2-O-beta-D-glucoside (6%) and 6-isopropyltropolone 2-O-beta-D-glucoside (12%), and two gentiobiosides, 4-isopropyltropolone 2-O-beta-D-gentiobioside (2%) and 6-isopropyltropolone 2-O-beta-D-gentiobioside (5%) after 48 h incubation. The use of immobilized cells of N. tabacum in sodium alginate gel much improved the yield of the products; the glycosylation of beta-thujaplicin with immobilized N. tabacum gave the glycoside products, 4-isopropyltropolone 2-O-beta-D-glucoside (11%), 4-isopropyltropolone 2-O-beta-D-gentiobioside (6%), 6-isopropyltropolone 2-O-beta-D-glucoside (20%), and 6-isopropyltropolone 2-O-beta-D-gentiobioside (10%). On the other hand, 4-isopropyltropolone 2-O-beta-D-glucoside (14%), 4-isopropyltropolone 2-O-beta-D-gentiobioside (7%), 6-isopropyltropolone 2-O-beta-D-glucoside (33%), and 6-isopropyltropolone 2-O-beta-D-gentiobioside (13%) were obtained through the biotransformation with immobilized cells in the medium without iron ions. In comparison with the case of bioconversion in the normal medium containing iron ions, removal of iron ions improved the yields of products.

Stimulation of Fusobacterium nucleatum biofilm formation by Porphyromonas gingivalis

BACKGROUND/AIMS

Bacterial infection is a major cause of periapical periodontitis. Eradication of these microorganisms from apical lesions is essential to the success of endodontic treatment. The aim of this study was to clarify the molecular interaction between Fusobacterium nucleatum, Porphyromonas gingivalis and other microorganisms associated with periapical periodontitis.

METHODS

Microorganisms isolated from periapical lesions were inoculated into type-I collagen-coated polystyrene microtiter plates and maintained at 37 degrees C under anaerobic conditions for 2 days, after which, the quantity of organized biofilm on the plates was evaluated by crystal violet staining. Growth enhancement via soluble factor was evaluated by separated coculture using a 0.4-mum membrane filter.

RESULTS

F. nucleatum exhibited strong adherence to type-I collagen-coated polystyrene microplates. Biofilm formation by F. nucleatum was significantly enhanced by P. gingivalis. It was complemented by compartmentalized coculture with P. gingivalis. Enhancement of biofilm formation by P. gingivalis was only slightly reduced by inactivation of its autoinducer-2-producing gene luxS.

CONCLUSION

The results suggest that P. gingivalis enhances biofilm formation by F. nucleatum by releasing diffusible signaling molecules other than autoinducer-2.

Heterogenic virulence and related factors among clinical isolates of Porphyromonas gingivalis with type II fimbriae

BACKGROUND/AIMS

Porphyromonas gingivalis is a periodontal pathogen whose fimbriae are classified into six genotypes (types I-V and Ib) based on the diversity of the fimA genes encoding the fimbrial subunits. Accumulated evidence suggests that P. gingivalis strains with type II fimbriae are more virulent as compared to those with other types. However, it is unknown if strong virulence is uniformly conserved among clones with type II fimbriae. In the present study, we compared infectious inflammatory changes in clinical isolates of P. gingivalis with type II fimbriae using a mouse abscess model to examine their pathogenic heterogeneity and heterogeneity-related factors.

METHODS

Suspensions of nine different clinical isolates with type II fimbriae were subcutaneously injected into female BALB/c mice and inflammatory parameters, such as serum sialic acid concentration, were compared.

RESULTS

Many of the type II fimbrial isolates caused severe inflammation in the mice, though some were less causative, as was the control strain ATCC 33277 (type I fimbria strain). These results showed that pathogenic heterogeneity exists among P. gingivalis clones with type II fimbriae. Further, the heterogeneity-related factors of P. gingivalis strains were analyzed and the pathogenic potentials showed positive relationships to gingipain activities and invasive efficiency but not to hydrophobicity or autoaggregation. In addition, invasive efficiency was related to the activities of gingipains that were extracellularly secreted.

CONCLUSION

These results suggest that pathogenic heterogeneity has relationships with the invasive and proteolytic activities of P. gingivalis clones with type II fimbriae.

Colonization pattern of periodontal bacteria in Japanese children and their mothers

BACKGROUND AND OBJECTIVE

The purpose of this study was to determine the time of infection by anaerobic gram-negative rods associated with periodontal disease, and to clarify their transmission from mother to child.

MATERIAL AND METHODS

Seventy-eight Japanese children (including 10 siblings), aged from 3 to 9 years, and 68 mothers, were enrolled in this study. Colonization by 11 periodontal bacterial species was determined using polymerase chain reaction amplification of samples of subgingival plaque obtained from the children and their mothers.

RESULTS

The detection rates of Porphyromonas gingivalis, Tannerella forsythensis and Treponema denticola increased in children after the age of 6 years. We found a high consistency in colonization by P. gingivalis, T. denticola, Prevotella intermedia and Prevotella nigrescens in 9 of the 10 siblings. The average number of bacterial species in plaque samples harboring Fusobacterium nucleatum and/or Fusobacterium periodonticum was significantly greater than in those without, in both children and mothers. Kappa statistical analysis revealed that the detection of Capnocytophaga gingivalis, Capnocytophaga ochracea, Campylobacter rectus and T. denticola in children was consistent with that in the mother.

CONCLUSION

Periodontal bacterial colonization in Japanese children increased with age and was associated with F. nucleatum and/or periodonticum, and the bacterial flora in children was similar to that in their mothers.

Changes of multi-drug resistance pattern in Salmonella enterica subspecies enterica serovar typhimurium isolates from food-producing animals in Japan

A total of 153 isolates of Salmonella Typhimurium derived from food-producing animals in Japan between 2002 and 2005 were investigated for antimicrobial resistance and phage types related to definitive phage type 104 (DT104). The predominant resistance type was resistance to ampicillin, dihydrostreptomycin, kanamycin, and oxytetracycline in bovine (45.2%, 48/104) and resistance to dihydrostreptomycin and oxytetracycline in porcine isolates (58.7%, 27/48). DT104-related phage type was found in 32 of 104 bovine isolates, two of 48 porcine isolates, and one of eight isolates from poultry, showing that the proportion of the phage type in S. Typhimurium isolates from cattle and pigs significantly (P<0.01) decreased from 71.9% and 31.4% in 1999-2001 to 30.8% and 4.1% in 2002-2005, respectively.

Inhibitory effect of cranberry polyphenol on biofilm formation and cysteine proteases of Porphyromonas gingivalis

BACKGROUND AND OBJECTIVE

The purpose of this study was to investigate the effects of cranberry polyphenol fraction on biofilm formation and activities of Arg-gingipain and Lys-gingipain in Porphyromonas gingivalis.

MATERIAL AND METHODS

The polyphenol fraction was prepared by using a glass column packed with Amberlite XAD 7HP and 70% aqueous ethanol as an elution solvent.

RESULTS

Synergistic biofilm formation by P. gingivalis and Fusobacterium nucleatum was significantly inhibited by the polyphenol fraction at a concentration of 250 microg/mL compared with untreated controls (p < 0.01). Arg-gingipain and Lys-gingipain activities in P. gingivalis ATCC 33277 and FDC 381 were inhibited significantly at a polyphenol fraction concentration of > or = 1 microg/mL (p < 0.05).

CONCLUSION

These findings indicate that the polyphenol fraction inhibits biofilm formation and the Arg-gingipain and Lys-gingipain activities of P. gingivalis.

Association of antimicrobial resistance in Campylobacter isolated from food-producing animals with antimicrobial use on farms

On 1,374 food-producing animal farms in 2001-2004, we investigated the influence of antimicrobial usage within 6 months before a survey conducted on antimicrobial resistance in Campylobacter. Tetracyclines and fluoroquinolones were used for therapeutic purposes on 107 and 21 farms, respectively. Oxytetracycline-resistant C. jejuni and C. coli were found in 57.1% (8/14) and 92.5% (37/40) of the farms, respectively, when the animals were treated with tetracyclines. However, they were found in 43.2% (112/259) and 74.3% (122/164) of the farms, respectively, when the animals were not treated with tetracyclines. Enrofloxacin-resistant C. jejuni and C. coli were found in 66.7% (2/3) and 16.7% (1/6) of the farms, respectively, when the animals were treated with fluoroquinolones. However, they were found in 15.5% (42/270) and 28.8% (57/198) of the farms, respectively, when the animals were not treated with fluoroquinolones. The percentage of oxytetracycline resistance in C. coli was significantly elevated when the animals were treated with tetracyclines (P < 0.05). The farms on which antimicrobials included by their resistance pattern were used accounted for 9.1% (4/44) and 24.1% (14/58) of the farms where enrofloxacin-resistant C. jejuni and C. coli were isolated, respectively. It is likely that several factors account for the presence of fluoroquinolone-resistant Campylobacter.

Phase I study of amrubicin (AMR) for patients (pts) with previously treated small cell lung cancer (SCLC)

18209

Background: Amrubicin, a totally synthetic 9-amino-anthracycline, has been demonstrated to have excellent antitumor activity against previously untreated SCLC. However, severe hematological toxicities were observed in previously treated SCLC when given at doses of 40 to 45 mg/m2, days 1–3. We sought to determine the maximum tolerable dose (MTD) and toxicity of amrubicin for pts with previously treated SCLC. Methods: Pts with confirmed SCLC, ECOG PS 0–1, and 20 to 74 years of age, with a history of receiving one or two regimens were eligible for the study. Pts were divided into two groups. Group R (-) consisted of pts without history of radiotherapy except prophylactic cranial irradiation. Group R (+) consisted of pts with history of irradiation up to two fields including thoracic radiotherapy. AMR was initially given at 35 mg/m2, iv, days 1–3, every 3 weeks in both groups. The dose was then increased to 40 and 45 mg/m2. Three pts were treated at each dose level in the absence of a dose limiting toxicity (DLT). All pts received prophylactic hG- CSF between days 8–13. DLT was defined as neutrophil nadir <500/μL lasting more than 4 days, neutropenic fever and neutrophil nadir <1000/μL, platelet nadir <20,000/μL or ≥ grade 3 non-hematologic toxicities. Results: Fourteen pts were enrolled, 10m/4f. The median age was 62 years (range 34–82). Two of 6 pts in the first cohort in group R (-) had dose-limiting neutropenia. The dose escalation is ongoing. Three pts in the first cohort in group R (+) had no dose-limiting toxicities. A subsequent 5 pts were treated at dose-level 2, and 3 pts had dose-limiting neutropenia. The MTD in group R (+) was 40 mg/m2. A response rate of 62% was observed. Median survival time was 12 months. No treatment-related death was observed. Conclusions: The MTD in group R (-) was not determined. The MTD in group R (+) was determined as 40 mg/m2. Further data will be presented.

No significant financial relationships to disclose.

Arg-gingipain A DNA vaccine prevents alveolar bone loss in mice

One major pathogenic factor of Porphyromonas gingivalis is Arg-gingipain (Rgp), an arginine-specific cysteine proteinase. To clarify the effect of rgpA DNA vaccine, we immunized BALB/c mice via the abdomen with a Gene Gun or via the nasal cavity weekly for 6 weeks. After immunization, the mice were challenged orally with P. gingivalis. Immunization elicited IgG responses against P. gingivalis in both groups. Nasal immunization also induced sIgA against P. gingivalis, although Gene Gun immunization did not. Reduction of alveolar bone loss was observed in both groups at 42 days following initial infection. This effect was more pronounced in the intranasal immunization group than in the Gene Gun group. The results of this study suggest that immunization with rgpA DNA vaccine via the nasal cavity is an effective method for preventing alveolar bone loss incurred by infection with P. gingivalis.

Professional oral health care by dental hygienists reduced respiratory infections in elderly persons requiring nursing care

OBJECTIVES

Respiratory infection is a major cause of death in the elderly. We have evaluated the role of professional oral health care (POHC) by dental hygienists in reducing respiratory infections in elderly persons requiring nursing care.

METHODS

Two populations of elderly persons, one receiving POHC and one not, were examined to determine numbers of microorganisms, potent pathogens of respiratory infection, enzymatic activity in saliva, fevers, prevalence of fatal aspiration pneumonia and prevalence of influenza.

RESULTS

In the first population, we found a high prevalence of potent respiratory pathogens such as Staphylococcus species, Pseudomonas aeruginosa and Candida albicans. Patients who received POHC showed a lower prevalence for these pathogens than those who did not. The ratio of fatal aspiration pneumonia in POHC patients was significantly lower than that in patients without POHC (non-POHC) over a 24-month period (P < 0.05). The prevalence of a fever of 37.8 degrees C or more in POHC patients was significantly lower than that in the non-POHC group (P < 0.05). In the second study population, we investigated the effects of POHC on infection with influenza over a 6-month period. In the POHC group, neuraminidase and trypsin-like protease activities decreased, and one of 98 patients was diagnosed with influenza; whereas, in the non-POHC group, nine of 92 patients were diagnosed with influenza. The relative risk of developing influenza while under POHC was 0.1 (95% CI 0.01-0.81, P = 0.008).

CONCLUSION

These results suggest that POHC by dental hygienists is effective in preventing respiratory infections in elderly persons requiring nursing care.

Novel Immunosuppressant Agents Targeting Activated Lymphocytes by Biocompatible MPC Polymer Conjugated with Interleukin-2

The immunopharmacological profile of novel biocompatible water-soluble interleukin-2 (IL-2)-conjugated 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer immunosuppressive agents was established. MPC-co-n- butyl methacrylate (BMA)-co-p-nitrophenylcarbonyloxyethyl methacrylate (NPMA) (PMBN) was prepared as a backbone for these novel agents. PMBN contained MPC as a biocompatible unit, BMA as a hydrophobic domain in water, and NPMA as an immobilizable unit with IL-2. This research showed that proliferation of cell lines with high-affinity IL-2 receptors derived from T cell malignancies were suppressed by the PMBN conjugated with IL-2 (PMBN-IL2 conjugate) incorporating paclitaxel (PTX) and cyclosporin A at lower concentrations than used conventionally. PMBN-IL2 conjugates incorporating PTX also inhibited the proliferation of responder cells in a human mixed lymphocyte culture at a lower concentration than unconjugated drug. However, PMBN-IL2 conjugates incorporating FK506 inhibited proliferation no more than FK506 alone. The PMBN-IL2 conjugate with PTX may therefore be useful for selectively eliminating activated lymphocytes that hyperproduce high-affinity IL-2 receptors. As an entirely human 'immunotoxin analogue' it may not be associated with the dose-limiting toxicity and immunogenicity of conventional immunotoxins.

The effects of tetracycline, minocycline, doxycycline and ofloxacin on Prevotella intermedia biofilm

Prevotella intermedia, a black-pigmented, anaerobic, gram-negative bacterium, is associated with various type of periodontitis. Antibiotic treatments via a systemic or local route have been reported as being useful for treating periodontal disease. The purpose of this study was to examine the effects of four antibiotics, tetracycline (TET), minocycline (MINO), doxycycline (DOXY) and ofloxacin (OFLX) on P. intermedia biofilms at minimum inhibitory concentrations (MIC) from one-fold to 100-fold. MICs were determined for planktonic cells. Biofilm formation was determined with the crystal violet stain method and the bioactivities in the biofilms were determined with the adenosine triphosphate (ATP) -bioluminescent assay using a 96-well culture plate. At one-fold MIC, DOXY inhibited biofilm formation by P. intermedia ATCC 25611. Other antibiotics at one-fold MIC had no effects on the biofilm formation of tested bacterial strains. In P. intermedia ATCC 25611 biofilms, all the antibiotics tested showed inhibitory activities at five- to 100-fold MICs. In the biofilms of P. intermedia strains, except ATCC 25611, treated with three tetracycline antibiotics, the bioactivities were significantly increased, indicating the difficulties involved in designing antibiotic therapy for periodontal disease.

Measurement of atmospheric neutrino flux consistent with tau neutrino appearance

A search for the appearance of tau neutrinos from nu(mu) <--> nu(tau) oscillations in the atmospheric neutrinos has been performed using 1489.2 days of atmospheric neutrino data from the Super-Kamiokande-I experiment. A best fit tau neutrino appearance signal of 138+/-48(stat)-32(+15)(syst) events is obtained with an expectation of 78+/-26(syst). The hypothesis of no tau neutrino appearance is disfavored by 2.4 sigma.

Antimicrobial resistance in Salmonella isolates from apparently healthy food-producing animal from 2000 to 2003: the first stage of Japanese veterinary antimicrobial resistance monitoring (JVARM)

Antimicrobial susceptibility of 183 Salmonella isolates from apparently healthy food-producing animals obtained during the period from 2000 to 2003 throughout Japan was examined. Of 29 serovars identified, Salmonella Infantis (37.7%) was the most prevalent, followed by S. Typhimurium (19.7%). Salmonella bacteria resistant to dihydrostreptomycin (77.6%) were about 10% more prevalent than those resistant to oxytetracycline (67.8%), though the nation-level veterinary use of tetracycline antibiotics is much greater than that of streptomycin in Japan. In seventeen isolates (9.3%) resistant to nalidixic acid, single point mutations were detected at 84 or 87 in the quinolone resistance-determining region of the gyrA gene.

Renal allograft injury is associated with urinary tract infection caused by Escherichia coli bearing adherence factors

Urinary tract infections are the most common infection in renal transplant patients and Escherichia coli (E. coli) is the most common clinical isolate. Although acute allograft injury (AAI) secondary to urinary tract infection (UTI) has been reported, the incidence of AAI associated with UTI, the virulence factors express by uropathic E. coli and whether virulence factors are associated with renal allograft outcome have not been described. We collected E. coli from our renal transplant patients with UTI, determined O:H serotypes, P and Dr fimbriae expression and the clinical presentation and allograft function during the UTI and post-UTI period. Pyelonephritis occurred in 40% of our patients, 82% of which had AAI (>20% increase in SCr). Sixty-two percent of E. coli isolates that expressed P fimbriae were associated with AAI, whereas only 29% that did not express P fimbriae had AAI (p = 0.03). The pattern of P fimbriae and O serotypes differed from reported isolates, as the P fimbriae PapG class II and the O25 serotype were the most common. Dr adhesin was expressed on 7 isolates, including 2 of 3 with urosepsis. We propose a unique pattern of uropathogenic serotypes and adherence factors contribute to acute allograft injury in renal transplant patients with UTI.

[Present situation of national surveillance of antimicrobial resistance in bacteria isolated from farm animals in Japan and correspondence to the issue]

The Japanese Veterinary Antimicrobial Resistance Monitoring System (JVARM) was formed in 1999 in response to international concerns about the impact of antimicrobial resistance on public health. The aim of the present investigation was to provide insight into the occurrence of antimicrobial resistance among bacterial strains isolated from cattle, swine and poultry on farms across Japan. In this paper, we summarize a nationwide investigation (1999-2003) on antimicrobial susceptibility of the targeted bacterial species for the JVARM, namely Salmonella, Campylobacter, Enterococcus and Escherichia coli, isolated from the feces of healthy domestic animals. Minimum inhibitory concentrations (MICs) of 10-18 antimicrobial agents including the major generic groups were determined using an agar dilution method according to the international NCCLS guideline in principle. The outline of present results is as follows: (1) A total of 307 Salmonella, 3,225 Escherichia coli, 2,822 Enterococcus and 1,122 Campylobacter were isolated from healthy domestic animals and examined for antimicrobial susceptibility. (2) The isolates of all targeted bacterial species represent high rates of antimicrobial resistance to both oxytetracycline (OTC) and dihydrostreptomycin (DSM). (3) Among the isolates of Campylobacter and E. coli, the frequency of isolation of resistance to fluoroquinolones ranged from 14 to 24% and 2 to 3%, respectively. (4) Resistance to fluoroquinolones was not observed among the isolates of Salmonella or Enterococcus. Continious investigation at the nation level of antimicrobial resistance among the isolates from healthy domestic animals remains a high priority for the JVARM program. Furthermore, appropriate and prudent use of antimicrobials for diseased animals should be considered essential.

High-dose ifosfamide, carboplatin and etoposide (HD-ICE) with peripheral blood stem cell transfusion (PBSCT) for limited stage small-cell lung cancer (LD-SCLC)

7090

Background: Efficacy of high dose chemotherapy with autologous PBSCT has been demonstrated in the treatment of lymphoma. The purpose of this trial is to determine progression-free survival and long-term survival for LD-SCLC patients (pts) who responded to first-line concurrent chemo-radiotherapy followed by HD-ICE with PBSCT. Methods: Patients (pts) with pathologically proven SCLC without malignant pleural and pericardial effusion, stage II-IIIB, ECOG-PS 0–1 were eligible. All pts were treated with cisplatin (P) 60 mg/m2 day1 and etoposide (E) 100 mg/m2, days 1–3, with concurrent hyperfractionted radiotherapy initially (1.5Gy X 2/day X 15 days, total 45Gy) and then two or three cycles of chemotherapy consisted of P 60 mg/m2, day 1, and E 120 mg/m2, days 1–3, or APE (adriamycin 30 mg/m2, day 1, P 60 mg/m2, day1 and E 100 mg/m2, days 1–3) were repeated. Pts with tumor shrinkage more than 90% after initial therapy received HD-ICE (ifosfamide 3 g/m2, days 1–3, carboplatin 400 mg/m2, days 1–3, etoposide 400 mg/m2, days 1–3) followed by PBSCT. All pts received prophylactic cranial irradiation (1.5 Gy × 2/day × 9 days, total 27 Gy). Results: Between 1996 and 2001, 15 pts were eligible and all 15 pts received HD-ICE with PBSCT. Patient characteristics included M/F:14/1, median age: 55 (47–62), PS 0/1: 7/8 stage IIIA/IIIB: 7/8. Grade IV neutropenia and thorombocytopenia were observed in all pts and 93% of pts experienced neutropenic fever after HD-ICE. There was no toxic death. Median follow up time was 83.2 months. Median progression free survival time was 10. 7 months and overall median survival time (MST) was 30.9 months. Two, 3 and 5-year survival rates after initial chemoradiotherapy were 67%, 33%, 25%, respectively. Conclusion: HD-ICE with PBSCT for LD-SCLC revealed promising MST and a 5-year survival rate with manageable treatment-related toxicity. A randomized phase III study comparing chemo-radiotherapy followed by HD-ICE with PBSCT to standard chemo-radiotherapy for LD-SCLC is ongoing.

No significant financial relationships to disclose.

Improved search for nu(mu) --> nu(e) oscillation in a long-baseline accelerator experiment

We performed an improved search for nu(mu) --> nu(e) oscillation with the KEK to Kamioka (K2K) long-baseline neutrino oscillation experiment, using the full data sample of 9.2 x 10(19) protons on target. No evidence for a nu(e) appearance signal was found, and we set bounds on the nu(mu) --> nu(e) oscillation parameters. At Deltam(2)=2.8 x 10(-3) eV(2), the best-fit value of the K2Knu(mu) disappearance analysis, we set an upper limit of sin(2)2theta(mue) < 0.13 at a 90% confidence level.

Drug resistance and random amplified polymorphic DNA analysis of Photobacterium damselae ssp. piscicida isolates from cultured Seriola (yellowtail, amberjack and kingfish) in Japan

AIMS

To investigate the antimicrobial susceptibility and genetic characteristics of Photobacterium damselae ssp. piscicida isolates obtained from cultured Seriola in Japan.

METHODS AND RESULTS

Minimal inhibitory concentrations of 14 antimicrobials for 74 isolates from Seriola in Japan in 2002 were determined. Isolates showed high frequencies of resistance to sulfamonomethoxine (SMMX) (97.3%), oxytetracycline (OTC) (77.0%), flumequine (FMQ) (77.0%), chloramphenicol (CP) (75.7%), kanamycin (KM) (63.5%) and oxolinic acid (OA) (62.0%), but low to ampicillin (ABPC) (2.8%). All isolates were susceptible to bicozamycin (BCM), fosfomycin (FOM) and florfenicol (FF). Of these isolates, 45 (60.8%) showed same resistance pattern (SMMX-OTC-FMQ-OA-CP-KM). In random amplified polymorphic DNA (RAPD) analysis, no difference was observed among our 74 field isolates and ATCC51736 isolated from Seriola in 1974 in Japan, but different from ATCC 17911 isolated from white perch in USA.

CONCLUSIONS

FF, BCM, FOM and ABPC were useful antimicrobials for treating pseudotuberculosis. However, the frequency of multidrug resistance was high. RAPD analysis showed homogeneity of isolates from Seriola in Japan.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrates that some antimicrobials were still useful for treating pseudotuberculosis and that P. damselae ssp. piscicida strains of same origin might have spread among Seriola in Japan since 1974.