The effects of climatic elements on Salmonella contamination of 240 chicken meat samples purchased from March 2015 to
February 2017 were investigated.
Salmonella was isolated from 143 samples (59.6%), and the most dominant serovars identified were Infantis (77/240,
32.1%) and Schwarzengrund (56/240, 23.3%).
Previous studies have reported S. Schwarzengrund contamination of broiler chickens only in western Japan; however, in
the present study, S. Schwarzengrund was also isolated from meat produced in eastern Japan suggesting that S.
Schwarzengrund-contaminated areas have expanded towards eastern Japan.
Air temperature showed a significant negative association with S. Schwarzengrund isolation for chicken meat produced
during periods with rising temperature (spring and summer) [odds ratio (OR), 0.894 to 0.935; P<0.01].
Moreover, the risk of S. Schwarzengrund contamination of chicken meat was higher during spring (OR, 3.951; P=0.008)
and winter (OR, 4.071; P=0.006) than during summer.
Effects of climatic elements and differences in contamination risk across seasons were not observed for any Salmonella
serovars and only S. Infantis, which could be attributed to differences in transmission patterns and vehicles among
Salmonella serovars.
市販鶏肉からのサルモネラの分離率
（Isolation rate of Salmonell from retailed chicken in Japan from 2015）
鶏肉のSalmonella Schwarzengrund 汚染に対する気温の影響（気温上昇期＝春・夏）
The effects of air temperature on Salmonella Schwarzengrund from chicken meat （ During the period of rising
temperature; Spring・Summer ）
鶏肉の産地別Salmonella Schwarzengrund分離率
（Percentage isolation of Salmonella Schwarzengrund from chicken meat for each production region）
南日本で飼育されたブロイラーにおけるCampylobacter保菌に及ぼす気候的要素の影響 Effect of climatic elements on Campylobacter colonization in broiler flocks reared in southern Japan from 2008 to 2012
To demonstrate the effect of climatic elements on Campylobacter colonization in broiler chickens reared in Japan, the
correlation between Campylobacter isolated from chickens (191 of 236 flocks, 80.9%) between 2008 and 2012 and climatic
elements was analyzed by logistic regression.
The rearing period of broiler was divided into 13 terms of 5 days each (total: 65 days). Terms were numbered
backwards, wherein a 0-term lag was considered as the sampling day plus 4 days before sampling; 1-term lag was the 5
days term before the 0-term lag, and so on, until the 12-term lag.
Air temperature showed a positive correlation with Campylobacter colonization from the 0- to 12-term lags in chickens
reared during the period of rising temperature and from the 0- to 4- and 6-term lags in chickens reared during the
period of decreasing temperature. The strong positive effect of air temperature on Campylobacter colonization,
particularly during the period of rising temperature, may be associated with the effect on the Campylobacter
environmental sources and/or vectors.
A positive correlation was observed between Campylobacter colonization and humidity when chicken houses were empty and
new chicks were introduced (from the 9- to 12-term lags) during the period of decreasing temperature (OR, 1.076 to
1.141). Thus, high humidity would be an important factor causing carry-over of Campylobacter infection during the period
of decreasing temperature.
We also found that solar radiation increased Campylobacter colonization during the period of decreasing temperature,
from the 2- to 8-term lags, except for the 4- and 5-term lags, in Japan. The results of this study demonstrate the
effects of air temperature, humidity, and solar radiation on Campylobacter colonization in broiler chickens, and are
potentially important for developing strategies to reduce the risk of Campylobacter contamination in broiler chickens.
肉用鶏のカンピロバクター保菌に対する飼育期間中の気温の影響
（The effects of air temperature on Campylobacter colonization）
肉用鶏のカンピロバクター保菌に対する飼育期間中の湿度の影響
（The effects of relative humidity on Campylobacter colonization）
