著者

Yoichiro Shimura Nobuo Shoji Taichiro Tanikawa Tomoaki Obayashi Jun Honda Miyuki Tanaka Yukiko Sasaki Jun Fukushima Tamio Inamoto

出版者

日本家禽学会

雑誌

The Journal of Poultry Science (ISSN:13467395)

巻号頁・発行日

vol.53, no.2, pp.165-172, 2016 (Released:2016-04-25)

参考文献数

33

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To determine the influence of media composition on Salmonella exclusion of Nurmi-type cultures, two and four types of cultures in the first and second trial, respectively, were prepared from the cecal contents of conventional laying hens, and Salmonella exclusion was assessed in newly hatched chicks. In the first trial, modified Viande Levure (VL) broth or nutrient broth (NB) were used to prepare Nurmi-type cultures (N-VL and N-NB), which were administered to the newly hatched chicks. Twenty-four hours later, the chicks were challenged with Salmonella enterica Typhimurium EF85-9 (ST). ST recoveries (log10 colony forming units/g of cecal contents) from the N-VL-, N-NB-, and control-treated groups 5 days after the challenge were 7.6±0.6, 0.9±1.9, and 7.7±0.4, respectively. The results suggested the influence of L-cysteine (Cys) present in the VL broth. Thus, we determined the effect of Cys in the second trial. We prepared two other cultures using VL broth without Cys (N-VL—Cys) and NB with Cys (N-NB+Cys). ST recoveries from the cecal contents of the N-VL-, N-VL—Cys-, and control-treated groups were 6.3±0.9, 2.1±2.5, and 9.2±0.8, respectively. ST was not recovered from the N-NB- and N-NB+Cys-treated groups. To identify bacteria with Salmonella exclusion activity, we isolated 41 bacterial strains from the ceca of N-NB-treated chicks without Salmonella challenge. Most isolates were identified as Enterococcus faecalis or E. mundtii based on 16S rRNA gene sequencing, and only four cultures excluded Salmonella. Therefore, VL broth containing Cys was not always required for preparing Nurmi-type cultures. The use of media prepared with Cys at the lowest possible concentration or without Cys would promote to enhance Salmonella exclusion from Nurmi-type cultures.

著者

Emi Takashita Hiroko Morita Shiho Nagata Masayuki Shirakura Seiichiro Fujisaki Hideka Miura Ikuyo Takayama Tomoko Arita Yasushi Suzuki Masaoki Yamaoka Taichiro Tanikawa Ryota Tsunekuni Junki Mine Saki Sakuma Yuko Uchida Akihiro Shibata Mari Iwanaka Noriko Kishida Kazuya Nakamura Tsutomu Kageyama Shinji Watanabe Hideki Hasegawa The Influenza Virus Surveillance Group of Japan

出版者

National Institute of Infectious Diseases, Japanese Journal of Infectious Diseases Editorial Committee

雑誌

Japanese Journal of Infectious Diseases (ISSN:13446304)

巻号頁・発行日

pp.JJID.2021.751, (Released:2021-12-28)

参考文献数

15

被引用文献数

1

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Circulation of avian influenza A viruses in poultry is a public health concern because these viruses may cause severe disease in humans and have the potential to become more transmissible among humans. Monitoring the susceptibility of these viruses to antivirals is important for influenza pandemic preparedness. However, information about their antiviral susceptibility is limited. Here, we determined the susceptibilities of avian influenza A(H5N1), A(H5N2), A(H5N8), A(H7N7), A(H7N9), A(H9N1), and A(H9N2) viruses isolated in Japan to the antivirals approved for use there: the M2 inhibitor amantadine; the neuraminidase inhibitors oseltamivir, peramivir, zanamivir, and laninamivir; and the RNA polymerase inhibitors baloxavir and favipiravir. Genotypic methods that detect amino acid substitutions associated with antiviral resistance and phenotypic methods that assess viral susceptibility to drugs revealed that these avian influenza A viruses are susceptible to neuraminidase inhibitors and RNA polymerase inhibitors. These results suggest that the neuraminidase inhibitors and the RNA polymerase inhibitors currently approved in Japan could be a treatment option against influenza A virus infections in humans.