PulseNet Japan is a network system for utilizing epidemiological information and the results of laboratory investigations of foodborne illness outbreaks. We have been analyzing DNA pattern of foodborne pathogens such as enterohemorrhagic Escherichia coli (EHEC) isolates by the use of pulsed-field gel electrophoresis (PFGE). The method, capable of discriminating genotypical difference of the isolates, enabled us to find the contaminated food such as salmon roe which was the causative agent for the multiprefectual outbreaks in Japan. PFGE results of the isolates and other epidemiological information have been accumulated to construct database for foodborne bacterial pathogens for sharing and making use of the information among municipal public health institutes, National Institute of Infectious Diseases and the Ministry of Health, Labor and Welfare.

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Antimicrobial agents are essential for human and animal health and welfare, but antimicrobial use can lead to antimicrobial resistance. The resistance arising from antimicrobial use in food-producing animals represents a potential hazard to human medicine through foodborne infection caused by resistant bacteria. In Japan, the Japanese Veterinary Antimicrobial Resistance Monitoring System (JVARM) was formed in 1999 in response to international concern about the impact of antimicrobial resistance on public health. In the JVARM program, initial monitoring for antimicrobial-resistant bacteria was carried out in 1999 and then the first and second stages of the JVARM program were completed in 2000-2003 and 2004-2007, respectively.
Veterinary antimicrobial use is a selective force for appearance and prevalence of antimicrobial-resistant bacteria in food-producing animals. However, antimicrobial-resistant bacteria are found in the absence of antimicrobial selective pressure. We show here the relationship between antimicrobial usage and prevalence of resistant bacteria under the JVARM from 1999 to 2007.

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This study aimed to investigate the relationships between behavior, lifetime reproductive performance and salivary cortisol in stalled gestating female pigs. A commercial farm with approximately 300 female pigs was visited eight times for three years. Three postural behaviors and the vacuum chewing behavior were recorded at 15-min intervals for 6 hours by using point sampling. Of 1,570 observations, 1,285 were farrowed, and 427 females were culled during the study period. Relative frequency (%) of vacuum chewing was used to divide 30 gestating females into two groups : no-vacuum chewing and high-vacuum chewing. Salivary samples were collected from the gestating female pigs in the two groups. The correlations between consecutive parities in each behavior were analyzed. Associations between behaviors and lifetime performance were separately analyzed at each parity. As parity increased from 0 to 3, vacuum chewing increased from 8.14 to 13.1%. Relative frequencies (%) of vacuum chewing between consecutive parities 0 and 5 were positively correlated (P<0.05). No differences in salivary cortisol concentrations were found between the high- and the no-vacuum chewing groups. In parities 4 and 5, lower vacuum chewing frequency was associated with greater lifetime average total pigs born and pigs born alive (P<0.05).

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The stereotypy behavior is defined as the repetitive and relatively invariant behavior pattern with no obvious function. Increased stereotypy behavior raises a concern for poor well-being for animals. The dog-sitting (sitting) behavior in sows is considered as one of the stereotypies. The objectives of this study were to investigate the relationships between sitting behaviors and longevity of sows and to compare sitting behaviors among sows culled for “locomotion” and “other reasons.” A commercial farrowing-to-finish farm with approximately 300 female pigs was visited 11 times for 3 years to record the behaviors of sows using time-lapse video recorders for 24hr. Sitting behaviors were measured as the total duration of sitting postures for 24hr and the average duration of sitting bouts The lifetime records of each sow were collected using a software system. Sows were categorized into two groups of : high and low longevity. High longevity groups included the sows having both parity at cullin≥6 and the culling reason was “old age.” The other sows were categorized into the low longevity groups. Sows culled at the observed parity were divided into two groups on the basis of culling reasons : sows culled for “locomotion” and sows culled for “other reasons.” Among the 205 sows observed, means of total duration of sitting postures for 24hr and average duration of sitting bouts were found to be 80.7±3.44min and 2.6±0.11min, respectively. No differences were found in the total duration of sitting postures and average duration of sitting bouts between the two longevity groups. Additionally, both sitting behaviors were not related with herd-entry to culling interval and lifetime pigs born alive. The groups, which were classified on the basis of culling reasons, showed no differences in terms of sitting behaviors. In conclusion, sitting behaviors in lactating sows were not related to longevity and lifetime performance.

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Since September 2001, Japan has reported 35 BSE cases to the OIE including a few atypical cases. There were at least two major exposures in Japan. The first exposure to BSE occurred between 1995 and 1996, and 13 Holstein cows (Group A) have been detected in different parts of Japan due mainly to imported contaminated feed ingredients.
The second exposure occurred in Hokkaido between 1999 and 2001. As of April 2008 17 BES cases have been found there among the same cohort animals (Group B). Almost all positive cases of Groups A and B were Holstein cows. The remaining 5 cases (Group C) were of various ages including two native beef cattle. Two young (21and 23-month-old) Holstein steers are also included in Group C, but the transmissibility of these two cases has not been reported. Additional data on these 2 cases are needed to confirm that these were genuine BSE cases.
There were 4 cases in native Wagyu breed. Two were in Hokkaido among Group B cases, and the other two were old Wagyu (13 and 15 years of age) of Group C. It will be possible that future surveillance of BSE in Japan could be focused mainly in Hokkaido where a large number of Group B cohort cattle still remain. It will be also possible that Japan is divided into two zones, Hokkaido zone and the rest. Since the youngest typical BSE case confirmed in Japan was a 48-month-old cow of Group B, it is considered that the age of the cattle to be tested at abattoirs could be raised from 20 months to 36 months or older with negligible risks.
Three atypical cases of BSE have been found in Japan, but it is considered necessary to demonstrate the transmissibility of these cases in order to confirm that they are indeed TSE cases. So far only one case (No. 24) could be transmitted to mice. The author considers that it is necessary to review the surveillance systems in Japan with reference to the OIE standard for BSE surveillance. It is also considered necessary that more countries to look for atypical BSE cases in order to obtain enough data necessary for the OIE to define international rules dealing with atypical BSE cases.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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