Antimicrobial resistance in Escherichia coli isolates from Japanese raccoon dogs (Nyctereutes viverrinus) in Kanagawa Prefecture, Japan: Emergence of extended-spectrum cephalosporin-resistant human-related clones.

Introduction. Wild animals are one of the putative reservoirs of antimicrobial-resistant bacteria, but the significance of raccoon dogs remains to be investigated.Hypothesis. Raccoon dogs can be a reservoir of antimicrobial-resistant bacteria.Aim. This study aimed to explore the prevalence of antimicrobial resistance, mainly extended-spectrum cephalosporins resistance, in Escherichia coli isolates from faeces of 80 Japanese raccoon dogs in Kanagawa Prefecture, Japan.Methodology. All of the 80 faecal samples were streaked onto deoxycholate-hydrogen sulfate-lactose (DHL) and cefotaxime (CTX)-supplemented DHL (DHL-CTX) agars. Susceptibilities to ten antimicrobials were determined using the agar dilution method. Additionally, extended-spectrum ß-lactamases (ESBLs) and AmpC-type ß-lactamases (ABLs) were identified in addition to sequence types (STs), in ESC-resistant isolates by a polymerase chain reaction and sequencing.Results. Out of all the samples, 75 (93.8 %) and 20 (25.0 %) E. coli isolates were isolated by DHL and DHL-CTX agars, respectively. Significantly higher resistance rates to most of the drugs were found in DHL-CTX-derived isolates than DHL-derived isolates (P<0.01). Genetic analysis identified CTX-M-14 (n=6), CTX-M-2 (n=2), CTX-M-1 (n=1) and CTX-M-55 (n=1) as ESBLs, and CMY-2 (n=8) and DHA-1 (n=1) as ABLs in 20 DHL-CTX-derived isolates. Most of the detected STs were related to Japanese humans (i.e. ST10, ST58, ST69, ST131, ST357, ST648 and ST4038). Notably, this is the first report on ST69, ST131, ST155 and ST648, which are well-known international high-risk clones in Japanese raccoon dogs.Conclusion. Our findings underscore the need to understand the significance of raccoon dogs as an antimicrobial-resistant bacteria reservoir using one health approach.

Determination of minimum biofilm eradication concentrations of orbifloxacin for canine bacterial uropathogens over different treatment periods.

Biofilm formation can cause refractory urinary tract infections (UTIs) in dogs; however, minimum biofilm eradication concentrations (MBECs) of veterinary drugs against canine uropathogens remain to be investigated. In this study, the MBECs of orbifloxacin (OBFX), trimethoprim-sulfamethoxazole (TMS) and amoxicillin/clavulanate (ACV) over different time periods for treatment of canine uropathogenic Escherichia coli (n = 10) were determined. The MBECs of OBFX for other bacterial uropathogens, including Staphylococcus pseudintermedius (n = 5), Pseudomonas aeruginosa (n = 5), Klebsiella pneumoniae (n = 5) and Proteus mirabilis (n = 5) were also determined. Minimum inhibitory concentrations (MICs) were identified for all strains by broth microdilution, and MBECs were determined at 24, 72, and 168 hr using the Calgary biofilm method. The 24 hr MBECs of OBFX, TMS and ACV for the E. coli strains were significantly higher than the MICs (P < 0.05), and the 72 and 168 hr MBECs were significantly lower than those at 24 hr (P < 0.05). In addition, the 24 hr OBFX MBECs for the four other uropathogens were significantly higher than the corresponding MICs (P < 0.05). The 72 and/or 168 hr OBFX MBECs for S. pseudintermedius, K. pneumoniae and P. mirabilis were significantly lower than the 24 hr concentrations (P < 0.05), whereas for P. aeruginosa, no significant difference was found between any of the MBECs (P > 0.05). These data indicate that the administration period and uropathogenic bacterial species are important factors affecting the efficacy of OBFX treatment of biofilm-related UTIs in dogs.

Burdock fermented by Aspergillus awamori elevates cecal Bifidobacterium, and reduces fecal deoxycholic acid and adipose tissue weight in rats fed a high-fat diet.

This study investigated the effects of dietary supplementation with burdock powder and Aspergillus awamori-fermented burdock powder at 5% on the intestinal luminal environment and body fat in rats fed a high-fat (HF) diet. Food intake and growth were unaffected by dietary manipulation. Consumption of the burdock and fermented burdock diets significantly elevated fecal IgA and mucins (indices of intestinal immune and barrier functions) and reduced fecal lithocholic acid (a risk factor for colon cancer) (p<0.05). The fermented burdock diet markedly elevated cecal Bifidobacterium and organic acids, including lactate, acetate, propionate, and butyrate, and reduced fecal deoxycholic acid (a risk factor for colon cancer) and perirenal adipose tissue weight (p<0.05), but the burdock diet did not. These results suggest that consumption of fermented burdock improves the intestinal luminal environment and suppresses obesity in rats fed a HF diet.

Antioxidant activity of the giant jellyfish Nemopilema nomurai measured by the oxygen radical absorbance capacity and hydroxyl radical averting capacity methods.

The giant jellyfish Nemopilema nomurai (reaching sizes of up to 2 m diameter and 150 kg), which forms dense blooms, has caused extensive damage to fisheries by overloading trawl nets, while its toxic nematocysts cause dermatological symptoms. Giant jellyfish are currently discarded on the grounds of pest control. However, the giant jellyfish is considered to be edible and is part of Chinese cuisine. Therefore, we investigated whether any benefits for human health may be derived from consumption of the jellyfish in order to formulate medicated diets. Antioxidant activity of Nemopilema nomurai was measured using the oxygen radical absorbance capacity (ORAC) and hydroxyl radical averting capacity (HORAC) methods. Based on the results, the ORAC value of the giant jellyfish freeze-dried sample was 541 µmol trolox equivalent (TE)/100 g and the HORAC value was 3,687 µmol gallic acid equivalent (GAE)/100 g. On the other hand, the IC50 value of hydroxyl radical scavenging activity measured by using the electron spin resonance method was 3.3%. In conclusion, the results suggest that the freeze-dried powder of the giant jellyfish Nemopilema nomurai is a potentially beneficial food for humans.

Farm-level impact of therapeutic antimicrobial use on antimicrobial-resistant populations of Escherichia coli isolates from pigs.

We investigated the farm-level impact of the use of several different antimicrobial agents on the population of antimicrobial-resistant commensal bacteria of animal origin to appropriately assess the release risk of resistance. This study was carried out based on the results of a survey on the history of antimicrobial drug use in 297 pig farms and antimicrobial susceptibility testing for the 545 Escherichia coli isolates (one or two isolates/pig/farm). A comparative analysis with the nonexposed herd revealed that ampicillin (ABPC) resistance in E. coli increased in the herds that were exposed to penicillin (relative risk [RR], 1.75) and penicillin-streptomycin (RR, 2.28); dihydrostreptomycin (DSM) resistance, in the penicillin-streptomycin-exposed herd (RR, 1.75); and trimethoprim (TMP) resistance in the methoprim-sulfonamide-exposed herd (RR, 2.10). On the other hand, ABPC and DSM resistances increased in the tetracycline-exposed herd (RR, 1.66 and 1.58, respectively); TMP resistance, in the penicillin-exposed herd (RR, 1.77); and oxytetracycline and kanamycin resistances, in the penicillin-streptomycin-exposed herd (RR, 1.28 and 2.22, respectively). These results demonstrated that the development of cross-resistance and coresistance, imposed by the therapeutic use of the antimicrobials studied, contributed the farm-level prevalence of antimicrobial-resistant E. coli and that the influence of coselection was characteristic to individual antimicrobial agents used.

Measurement of the radical scavenging activity of chicken jelly soup, a part of the medicated diet, 'Yakuzen', made from gelatin gel food 'Nikogori', using chemiluminescence and electron spin resonance methods.

We reported that gelatin gel 'Nikogori' soup made from the collagen in chicken wing meat, which is a part of the medicated diet 'Yakuzen', has high peroxyl and hydroxyl radical scavenging activities as the antioxidative capacity using chemiluminescence and electron spin resonance methods. The peroxyl radical scavenging activity of the soy sauce and chicken jelly 'Nikogori' soup sample was much higher than that of the chicken-only sample (control) at 100 degrees C heating for 60 min, although the addition of soy sauce only slightly enhanced the hydroxyl radical scavenging activity. Although the addition of garlic slightly enhanced the hydroxyl radical scavenging activity, it strongly inhibited the peroxyl radical scavenging activity. We found that chicken jelly 'Nikogori' soup only and soup with the addition of soy sauce had the highest antioxidative capacity as part of the medicated diet, 'Yakuzen'.

Synergistic cell-killing effect of a combination of hyperthermia and heavy ion beam irradiation: in expectation of a breakthrough in the treatment of refractory cancers (review).

We studied the sensitivity against heavy ion beam and hyperthermia on radioresistant procaryote, Deinococcus radiodurans, for the purpose of cancer therapy. First, we examined the decrease of the survival rate and molecular weight of DNA purified from this cell by acid heat treatment. These decreases were recognized by heating at 55 degrees C below pH 5.0. Then, we assumed that the decrease in survival of D. radiodurans in vivo and damage to its DNA in vitro by acid heating were due to the release of purine rings from the phosphodiester backbone of DNA molecules, i.e., depurination. Second, we investigated the relation between LET (linear energy transfer) and RBE (relative biological effectiveness) on D. radiodurans dry and wet cells using AVF cyclotron at the TIARA facility of JAERI-Takasaki, Japan. These cells were irradiated with carbon (12C5+) ion beam at LET of about 100 keV/microm, neon (20Ne8+) ion beam at LET of about 300 keV/microm and oxygen (16O6+) ion beam at LET of about 400 keV/microm. The peak in the figure of the relation between LET and RBE value was found to increase according to the increase of LET value from 100 keV/microm. Third, we conducted combination treatment with 4.8 kGy of alpha-particles, i.e., boron 10 neutron captured beam induced by Kyoto University Research Nuclear Reactor operated at 5 MW, and hyperthermia at 52 degrees C, which caused the synergistic killing effect on D. radiodurans wet cells. However, being dissimilar to the case of gamma-irradiation, the interval incubation at 30 degrees C in the medium between both treatments could inhibit the recovery of survival.