Food safety, livestock health, and productivity of a farm fatting Japanese black cattle following implementation of a certificated Hazard Analysis and Critical Control Point (HACCP) system.

This study examined the safety and productivity data analysis of a beef cattle farm with Japanese black cattle over a 4-year period following the implementation of a Hazard Analysis and Critical Control Point (HACCP) system in 2018. The critical control point was "the selection of shipping cows" and no deviations from critical limits were observed, indicating the beef were safe. In addition, cattle treated for bovine respiratory disease (BRD) less than 6 months after the introduction of cattle decreased, while the average Beef Marbling Standard and quality of meat (i.e., grades A5, B5, A4, and B4) in beef carcass trade standard scores increased. These results suggest that the HACCP system had a positive effect on the health and meat quality of the cattle.

Food safety, livestock health, and productivity of a dairy farm following implementation of a certificated Hazard Analysis and Critical Control Points system.

This study examined the safety and productivity data analysis of a dairy farm over a 3-year period following the implementation of a Hazard Analysis and Critical Control Point (HACCP) system in 2018. The CCP was "the selection of milking cows" and the critical limit was "the withholding period has passed". No deviation from the critical limit was observed, the safety of the milk is ensured. In addition, the average daily milk yield per cow increased, while the average number of somatic cells/ml decreased. The number of cows with newly diagnosed mastitis increased, and the product excluded. These results suggest that the HACCP system had a positive effect on milk yield per cow and led to a decrease in somatic cells.

Prevalence of Salmonella in wild snakes in Japan.

A total of 87 wild snakes of 6 species in 2 families collected in Japan were examined for the presence of Salmonella. The prevalence of Salmonella was 58.6%, and that of Salmonella enterica subspecies I, which includes most human pathogenic serotypes, accounted for 12.6%. S. enterica subspecies I was isolated from Japanese grass snakes and Japanese four-striped snakes, and the isolates belonged to 6 serotypes: S. enterica subspecies enterica serotypes Eastbourne, Mikawashima, Narashino, Newport, Saintpaul, and Thompson. The prevalence of S. enterica subspecies IIIb was higher (41.4%) than that of S. enterica subspecies I, and it was isolated from 4 snake species. The prevalence of Salmonella enterica subspecies and isolation of serotypes that are commonly detected in reptiles and human salmonellosis suggest that wild snakes may become a source of Salmonella infection.

Epidemiological characteristics of Salmonella enterica serovar typhimurium from healthy pigs in Japan.

We characterized 53 Salmonella enterica ser. Typhimurium strains recovered from healthy pigs during 1998-1999 (n=12) and 2004-2005 (n=41) as to their carriage of DT104 spacer region, class 1 and 2 integrons, virulence genes (spvC, rck, and pefA), and XbaI- and BlnI-Pulsed-Field Gel Electrophoresis (PFGE) profiles. No DT104 strain was detected in 1998-1999, whereas 65.9% (27/41) of the strains in 2004-2005 were DT104 showing resistance to ampicillin, chloramphenicol, streptomycin, sulfonamides, tetracycline, and cephaloridine (R-type ACSSuT+). Class 1 intergron-associated genes, aadA2 (1.0-kbp amplicon) and pse1 (1.2-kbp amplicon), were found in all the DT104 strains (27/27). One strain showing resistance to streptomycin, sulfonamides, tetracyclin, and trimethoprim (R-type SsuTTm) harbored another class 1 integron-associated gene (dhfrXII-orfF- aadA2) on 1.9-kbp amplicon. Virulence gene spvC was found in 92.5% (49/53) and rck and pefA were found in 88.7% (47/53) of the strains, whereas spvC, rck, and pefA were found in all the DT104 strains. Ser. Typhimurium strains were categorized into four clusters (X1, X2, X3, and X4a/X4b) by XbaI-PFGE, or into nine clusters (B1, B2, B3a/B3b, B4, B5, B6, B7, B8, B9a/B9b) by BlnI-PFGE analyses. DT104 strains were restricted into X2, or into B2, B3a/B3b, and B6 clusters, indicating that our multidrug-resistant DT104 strains from healthy pigs might have derived from at least three independent clones, with the most widespread clone being the cluster B6 strains isolated in Kanto, Tokai, Chugoku, and Kyushu regions.

Antimicrobial susceptibilities of Salmonella from domestic animals, food and human in the Mekong Delta, Vietnam.

A total of 230 Salmonella isolates representing 33 serotypes originated from food (pork, beef, chicken meat, duck meat, and shrimp), domestic animals (pig, chicken, and duck), and human (children with diarrhea) in the Mekong Delta, Vietnam were examined for the antimicrobial resistance to 10 antibiotics. Of the 230 Salmonella isolates examined, 49 (21.3%) showed antimicrobial resistance. Thirty-eight isolates (16.5%) were resistant to oxytetracycline, 26 (11.3%) to chloramphenicol, 17 (7.4%) to nalidixic acid, 16 (7.0%) to streptomycin, 5 (2.2%) to kanamycin, and 4 (1.7%) to ampicillin. No isolate showed resistance to gentamicin, cefazolin, ceftriaxone, and ciprofloxacin. Among the resistant isolates, nineteen isolates were resistant to one antimicrobial agent, 10 to two, 15 to three, 3 to four, and 2 to five antimicrobial agents. The resistance rate of Salmonella isolates from the Mekong Delta, Vietnam to these antimicrobial agents seems to be relatively lower than the results of developed countries and even those of the neighboring countries.

Virulence characteristics of Yersinia pseudotuberculosis isolated from breeding monkeys in Japan.

Between April 2001 and 2007, 18 Yersinia pseudotuberculosis outbreaks occurred in breeding monkeys at 12 zoological gardens in Japan, and 28 monkeys of 8 species died. A total of 18 Y. pseudotuberculosis strains from the dead monkeys, comprising one strain per outbreak, were examined for serotype and the presence of the virulence genes virF, inv, ypm (ypmA, ypmB and ypmC) and irp2. Of the 18 Y. pseudotuberculosis strains, 7 (38.9%) were serotype 4b, 7 (38.9%) were serotype 1b, and there was one each of serotypes 2b, 3, 6 and 7. All the 18 strains examined harbored virF and inv. Sixteen (88.9%) strains, including the strain of serotype 7, harbored ypmA. However, no strain harbored ypmB, ypmC and irp2. This study demonstrated that among other pathogenic factors, almost all the Y. pseudotuberculosis isolated from the outbreaks had the ypm gene encoding the superantigenic toxin, YPM. As most of the monkeys who died in those outbreaks originated from South America and other regions, where the presence of the ypm gene have not been reported, YPM might be the cause, or at least the most important factor for, the high mortality of the breeding monkeys infected by Y. pseudotuberculosis in Japan. This is also the first report of a fatal case due to Y. pseudotuberculosis serotype 7 infection in the world.

Immuno-magnetic separation and agar layer methods for the isolation of freeze-injured Yersinia enterocolitica O:8 from water.

To develop an effective method to isolate an injured pathogenic Yersinia enterocolitica O:8 organism from environmental samples, we compared the isolation of freeze-injured and non-injured Y. enterocolitica O:8 and found that the isolation was more successful when immuno-magnetic separation (IMS) with anti-Y. enterocolitica O:8 antibody was used. Plating onto cefsulodin-irgasan-novobiocin (CIN) agar and Virulent Yersinia enterocolitica (VYE) agar by means of the agar layer method was found to be effective in isolating the injured cells. The alkali treatment which is generally used for selective detection of Yersinia organism failed to isolate freeze-injured pathogenic Y. enterocolitica O:8 cells. Recovery methods without using the alkali treatment were superior for detecting freeze-injured Y. enterocolitica O:8. Our results demonstrate that the IMS and the agar layer methods should be used to isolate injured pathogenic Yersinia organisms from environmental samples such as water.

Contamination of Salmonella in retail meats and shrimps in the Mekong Delta, Vietnam.

From March 2000 to September 2001, 608 samples of retail meat (136 pork, 70 beef, 202 chicken, and 200 ducks) and 110 samples of retail shrimp from six provinces of the Mekong Delta in Vietnam were collected individually and examined for the prevalence of Salmonella. Of the 718 samples examined, 243 (33.8%) were Salmonella positive. Salmonella was isolated from 69.9% of the pork samples, 48.6% of the beef samples, 21.0% of the chicken meat samples, 22.3% of the duck meat samples, and 24.5% of the shrimp samples. From 261 Salmonella isolates, 24 different serovars were identified. The predominant serovars of the isolates were Salmonella Derby, Salmonella Weltevreden, and Salmonella London in pork; Salmonella Weltevreden, Salmonella London, and Salmonella Dessau in beef; Salmonella Emek, Salmonella Typhimurium, and Salmonella Dessau in chicken meat; Salmonella Lexington, Salmonella Derby, and Salmonella Dessau in duck meat; and Salmonella Weltevreden, Salmonella Tennessee, and Salmonella Dessau in shrimps. Salmonella Bovismorbificans, Salmonella Derby, Salmonella Dessau, and Salmonella Weltevreden were the most common serovars in all the samples examined. These results indicate a high rate of contamination by Salmonella in retail meats and shrimps in the Mekong Delta, Vietnam.

Loss of milk yield due to Akabane disease in dairy cows.

Akabane disease is an infection with clinical signs of congenital malformation and abortion in ruminants. Abnormal parturitions caused by Akabane disease result in great economic loss. The purpose of this study is to estimate the reduction in the milk yield from abnormal parturition due to Akabane disease. The data were collected from 33 Holstein cows on 11 farms. The animals had abnormal parturitions during the period from September 1998 to March 1999, and were diagnosed as having Akabane disease. The mean and standard deviation of the rate of reduction in the milk yield of 33 cows after abnormal parturition caused by Akabane disease was -11.4 +/- 14.9%. The means and standard deviations of the rate of reduction of four cows calving abnormally at 220-239 days of gestation, nine cows calving abnormally at 240-270 days of gestation, and 20 cows calving abnormally at 271-300 days of gestation were -26.6 +/- 24.7%, -14.7 +/- 11.0%, and -6.9 +/- 12.3%, respectively. In this study, we demonstrated that the rate of reduction in the milk yield in cows affected by Akabane disease was -11.4 +/- 14.9%, but values as high as -26.6 +/- 24.7% were reached in the comparison with the milk yield obtained after normal parturition.

Yersinia enterocolitica serovar O:8 infection in breeding monkeys in Japan.

In the period from December 2002 to January 2003, 5 of 50 squirrel monkeys (Saimiri sciureus) housed at a Zoological Garden in the Kanto region of Japan died following a few days' history of diarrhea. After this outbreak had ended in the squirrel monkeys, 1 of 2 dark-handed gibbons (Hylobates agilis) died in April of 2003, showing similar clinical signs. We examined the organs of 3 of the dead squirrel monkeys and of the dark-handed gibbon, and Yersinia enterocolitica serovar O:8, which is the most pathogenic serovar of Y. enterocolitica, was isolated. In order to determine the source and the transmission route of infection, 98 fecal samples (45 from squirrel monkeys, 20 from other monkeys of 18 different species, and 33 from black rats captured around the monkey houses) and 7 water samples were collected in the Zoological Garden, and were examined for the prevalence of Y. enterocolitica serovar O:8. Serovar O:8 was isolated from 21 of 65 monkeys (32.3%) and 5 of 33 (15.2%) black rats (Rattus rattus). Furthermore, we examined the 30 isolates using molecular typing methods, pulsed field gel electrophoresis (PFGE), ribotyping using the RiboPrinter system, and restriction endonuclease analysis of virulence plasmid DNA (REAP), and compared the isolates in this outbreak with Japanese O:8 isolates previously identified. Genotyping showed that almost all the isolates were identical, and the genotype of the isolates was highly similar to that from wild rodents captured in Niigata Prefecture. This is the first report of fatal cases of Y. enterocolitica serovar O:8 infection in monkeys anywhere in the world.

Occurrence of yersiniosis and listeriosis in wild boars in Japan.

From December 1994 to February 1995, 131 wild boars (Sus scrofa leucomysta) living in a mountainous area in Japan were examined for yersiniosis and listeriosis. Of 131 wild boars, 76 (58%) were males and 55 (42%) were females. Four Yersinia spp. including Y. pseudotuberculosis, Y. enterocolitica, Y. frederiksenii, and Y. aldovei, were isolated from 49 (37%) of 131 wild boars. Yersinia pseudotuberculosis was isolated from five (4%) of 131 wild boars. All Y. pseudotuberculosis isolates were serotype 4b and harbored virulence plasmids. Yersinia pseudotuberculosis was isolated only from boars under 2-yr-old. No human pathogenic Y. enterocolitica was isolated. Listeria monocytogenes was isolated from two (1%) of the wild boars and both isolates were serotype 4b. These findings indicated that wild boar could be a reservoir of Y. pseudotuberculosis and L. monocytogenes in Japan.