Vitamin K Deficiency of Germfree Mice Caused by Feeding Standard Purified Diet Sterilized by .GAMMA.-Irradiation

Hirayama, Kazuhiro; Uetsuka, Koji; Kuwabara, Yoshibumi; Tamura, Motoi; Itoh, Kazuyoshi

doi:10.1538/expanim.56.273

Cited by 15 publications

(6 citation statements)

References 11 publications

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“…The majority of vitamin K homologue in the liver is vitamin K2, which has strong biological activity in the synthesis of coagulation factor [3,15], however, the plasma vitamin K2 level is less than the vitamin K1 level in normal rats [10]. In our study, the blood vitamin K2 level was also less than the vitamin K1 level in reported that vitamin K in diet was reduced by γ-radiosterilization [17]. Therefore, in the present study there is a possibility that vitamin K in the diet was sham-operated rats.…”

Section: Discussioncontrasting

confidence: 47%

Viability and Plasma Vitamin K Levels in the Common Bile Duct-Ligated Rats

et al. 2005

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The common bile duct-ligated (CBDL) rat, which is widely used as a model of human cirrhosis, rapidly develops secondary biliary cirrhosis (SBC) within [1,4,5,6,21,27]. Therefore the viability of this model is poor. Lee et al. improved the viability of CBDL rats by supplying a diet enriched with protein, ascorbic acid and vitamin K [20]. Beck reduced the mortality rate of this model from 20-25% to 10% within 4 weeks of operation by subcutaneous

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Section: Discussioncontrasting

confidence: 47%

Viability and Plasma Vitamin K Levels in the Common Bile Duct-Ligated Rats

et al. 2005

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“…Macronutrients such as carbohydrates, proteins, and fats are generally insensitive to irradiation, but some vitamins including A, K, B1, B6 and B12 are fairly sensitive. 32 Irradiation levels nearing the legal maximum may significantly reduce the contents of these vitamins and cause clinical signs 7,21 unless the feed is fortified after irradiation, further adding to the cost of the feed.…”

Section: Discussionmentioning

confidence: 99%

Effects of Pelleting, Irradiation, and Autoclaving of Rodent Feed on MPV and MNV Infectivity

Adams

Myles²,

Tracey

et al. 2019

j am assoc lab anim sci

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Murine norovirus (MNV) and mouse parvovirus (MPV) are among the most common adventitial viruses seen in laboratory mice, and infections arise in barrier facilities despite rigorous biosecurity programs. Some authors have implicated nonsterilized feed as a source of MPV in rodent facilities, but none have conclusively documented viral particles in the feed. In this study, we hypothesized that both viruses can resist the pelleting process but not subsequent irradiation or autoclaving, thus revealing a potential source of outbreaks in rodent facilities. To test this hypothesis, we contaminated powdered feed with 10-fold concentrations of MNV and MPV and fed it to both Swiss Webster (SW) and C57BL/6NTac (B6) mice to determine a 'powdered ID 50 ' according to seroconversion over a 28-d period. We repeated the experiment by using powdered feed that we contaminated with increasing viral doses (as no. of powdered ID 50) and subsequently pelleted; from these results, we determined a 'pelleted ID 50 .' Finally we assessed the effect of irradiation and autoclaving on contaminated pellets by using the same experimental design. The powdered ID 50 was relatively low and identical in both mouse strains (2.51 × 10 2 pfu) for MNV but higher in B6 (copy number, 3.20 × 10 6) than SW (3.98 × 10 4 copies) for MPV. As hypothesized, mice were infected by contaminated rodent feed despite the pelleting process. Indeed, pelleting resulted in a 1-to 2-log increase in ID 50 in both strains for MNV and MPV. Irradiation and autoclaving of infected pellets effectively prevented seroconversion of mice exposed to all doses of MNV, whereas a single mouse seroconverted at the highest dose of MPV (1.35 × 10 7 copies). These data suggest that both MNV and MPV remain infectious after conditions reproducing the rodent chow pelleting process and that nonsterilized rodent chow might be a source of viral outbreaks.

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“…Bacterial resistance to sterilization by irradiation has been linked to microbiological burden, moisture level, oxygen content, and temperature of the product (Halls, 1992;Hanson and Shaffer, 2001). Vitamin deficiencies also have been reported with irradiated diets (Caulfield et al, 2008, Hirayama et al, 2007. Vitamin deficiencies also have been reported with irradiated diets (Caulfield et al, 2008, Hirayama et al, 2007.…”

Section: Ionizing Radiationmentioning

confidence: 91%

“…Gamma irradiation offers advantages in economy and convenience over autoclaving and has been used to sterilize food and bedding for gnotobiotic animals for many years (Barc et al, 2004;Cahenzli et al, 2013;Caulfield et al, 2008;Cherbuy et al, 2010;Corpet et al, 1989;Gianni F, personal communication, October 2013;Hartmann et al, 2000;Hirayama et al, 2007;Hudcovic et al, 2009;Ley et al, 1969;Mabrok et al, 2012;Matsumoto et al, 1988;Mwangi et al, 2010;Paterson and Cook, 1971;Rabot et al, 2010;Respondek et al, 2013;Wrzosek et al, 2013;Yamanaka et al, 1977). Many users also consider irradiation to be more reliable than autoclaving, especially with difficult materials such as pelleted chow, and a few have replaced autoclaving entirely with irradiation (F. Gianni, personal communication, January 2014).…”

Section: Ionizing Radiationmentioning

confidence: 99%