Development of a biosecurity assessment tool and the assessment of biosecurity levels by this tool on Japanese commercial swine farms

It is well known that infectious diseases such as porcine reproductive and respiratory syndrome (PRRS) and porcine epidemic diarrhea (PED) decrease herd productivity and lead to economic loss. It is believed that biosecurity practices are effective for the prevention and control of such infectious diseases. Therefore, the objective of the present study was to investigate whether or not an association between biosecurity level and herd productivity, as well as disease status exists on Japanese commercial swine farms. The present study was conducted on 141 farms. Biosecurity in each farm was assessed by a biosecurity assessment tool named BioAsseT. BioAsseT has a full score of 100 and consists of three sections (external biosecurity, internal biosecurity and diagnostic monitoring). Production data for number of pigs weaned per sow per year (PWSY) and post-weaning mortality per year (PWM) were collected for data analysis. Regarding PRRS status, the farms were categorized into two groups: unknown or unstable and stable or negative. In addition, these farms were categorized based on their PED status, either positive or negative. The total BioAsseT score was associated with herd productivity: as total score increased by 1, PWSY increased by 0.104 pigs and PWM decreased by 0.051 % (P <  0.05). Herd productivity was associated with the score of external and internal biosecurity (P <  0.05), but did not correlate with the score of diagnostic monitoring. Regarding PRRS status, farms with an unknown or unstable status had lower total score than those with stable or negative status (P < 0.05). Similarly, PED positive farms had a lower total score compared to PED negative farms (P <  0.05). In conclusion, the present study provides evidence for the association between high biosecurity levels and increased herd productivity as well as a decreased risk for novel introductions of infectious diseases such as PED.

Impact of a porcine epidemic diarrhea outbreak on swine productivity in Japan: a retrospective cohort study

The objective was to investigate porcine epidemic diarrhea (PED) outbreak that occurred in 2014 in Japan and its effects on herd-level productivity using a data recording system (PigINFO). The study herds were selected from farrow-to-finish herds (n=99) that entered in the PigINFO system between July 2013 and March 2015. From 1 April to 30 June 2014 (PED epidemic), any herds with clinical signs of PED and feces positive for porcine epidemic diarrhea virus (PEDV) on polymerase chain reaction analysis and/or immunohistochemical staining were defined as PED-positive (n=38). They were further classified into those with long PED periods (L-PED-positive; n=28) and those with short PED periods (S-PED-positive; n=10). Herds with no clinical signs of PED were classified as PED-negative (n=61). Herd-level production data, including preweaning mortality (%; PRWM), postweaning mortality (%; POWM), pigs weaned per litter (PWL), pigs born alive per litter, litters per mated female per year and pigs marketed per sow (MP), were calculated every 3 months during study period. During the PED epidemic, L-PED-positive herds had significantly higher PRWM and POWM than PED-negative herds, and L-PED-positive and S-PED-positive herds had significantly lower PWL. During October–December 2014, L-PED-positive herds had significantly fewer MP than PED-negative herds. The PED outbreak increased mortality and consequently reduced the numbers of marketed pigs. The rapid control of an outbreak is important for reducing the financial losses arising from PED infections.

Aujeszky's disease and the effects of infection on Japanese swine herd productivity: a cross-sectional study

Pseudorabies virus (PRV) is endemic in some regions of Japan. We investigated the effects of PRV infection status on herd productivity. Serum samples were obtained from 48 swine herds in Japan. Within each herd, three serum samples were obtained from growing pigs at four different ages, as well as from sows in low and high parity groups. Sera were tested for antibodies against wild-type PRV via competitive ELISA. Herds were classified into PRV positive and negative groups based on serological results. Herds infected with PRV exhibited postweaning mortalities (6.84%) that were significantly (P=0.0018) higher than those in unaffected herds (4.73%). Because of the reduced productivity in PRV positive herds, the current PRV eradication program must be strengthened.

Effect of vibration on auditory organ systems in low-birth weight infants treated with high-frequency oscillatory ventilation: 5 year outcome

BACKGROUND

To determine the effects of vibration exposure caused by high-frequency oscillatory ventilation (HFOV) on the auditory organ systems in low-birth weight (LBW) infants.

METHODS

Between 1989 and 1990, 30 LBW infants who received assisted ventilation with HFOV (n = 14) or conventional mechanical ventilation (CMV; n = 16) in the level III neonatal intensive care unit at Tokyo Metropolitan Ohtsuka Hospital were enrolled in this study. The effects of vibration exposure on the auditory system structures were investigated with auditory brainstem responses (ABR) at 37-41 weeks of postconceptional age and at 6, 12, 18 and 24 months of age until they passed and follow-up studies were performed at least until 5 years of age.

RESULTS

All infants enrolled in the study survived at discharge and one (7.1%) infant in the HFOV group and two (12.5%) in the CMV group failed the initial ABR test, but there were no significant differences between the two groups. Auditory brainstem response abnormalities were still observed in one infant in the HFOV group at 6 months of age, but this child died at 9 months of age because of meningitis. In contrast, in the CMV group, one patient passed the ABR test at 6 months of age, but another remained abnormal at 5 years of age. One of three infants with ABR abnormalities at 6 months of age had neurologic sequelae at 5 years of age and one of 28 infants who passed the initial ABR test was detected with cerebral palsy. No patients with hearing loss were clinically detected at 5 years of age.

CONCLUSIONS

The results of the serial ABR examinations and the 5 year follow-up studies suggest that vibration exposure caused by HFOV may not increase the adverse effects on the auditory system in LBW infants.

New piericidin glucosides, glucopiericidins A and B

The new piericidin group antibiotics, glucopiericidins A and B were isolated from the culture broth of Streptomyces pactum S48727 (FERM P-8117) as co-metabolite of piericidin A1. The structures of glucopiericidins A and B were determined as piericidin A1, 10-O-beta-D-glucoside and piericidin A1, 3'-O-D-glucoside on the basis of their spectral and chemical properties, respectively. Glucopiericidins were more potent in inhibiting antibody formation than piericidin A1 in vitro. In addition, these substances showed better antimicrobial activities than piericidin A1. Acute toxicities of these substances in mice were lower than that of piericidin A1. This indicates that D-glucose in glucopiericidin molecules is important in modulating their physiological activities.

Azinomycins A and B, new antitumor antibiotics. III. Antitumor activity

Azinomycins A and B, isolated from the culture broth of Streptomyces griseofuscus S 42227, were examined for antitumor activities against P388 leukemia, P815 mastocytoma, B-16 melanoma, Ehrlich carcinoma, Lewis lung carcinoma and Meth A fibrosarcoma. Azinomycin B was markedly effective against the intraperitoneally inoculated tumors such as P388 leukemia, B-16 melanoma and Ehrlich carcinoma. The intraperitoneal administration of azinomycin B showed 57% survivors for 45 days and 193% ILS against P388 leukemia. For Ehrlich carcinoma, azinomycin B gave 161% ILS and 63% survivors for 45 days, but solid tumors such as Lewis lung carcinoma and Meth A fibrosarcoma were not susceptible to repeated injection of this substance. Azinomycin A was somewhat less effective than azinomycin B for the tumor systems tested.

Azinomycins A and B, new antitumor antibiotics. I. Producing organism, fermentation, isolation, and characterization

A strain of Streptomyces griseofuscus S42227 (FERM P-8443) was found to produce new antitumor antibiotics, called azinomycins A and B. The molecular formulas of azinomycins A and B were determined as C30H33N3O10 and C31H33N3O11, respectively. They were active against Gram-positive bacteria, Gram-negative bacteria and L5178Y cells in tissue culture.

Suppressive effect of cupric acetate on DNA alkylation, DNA synthesis and tumorigenesis in the liver of dimethylnitrosamine-treated rats

The effect of cupric acetate on dimethylnitrosamine (DMN)-induced hepatocarcinogenesis in rats was investigated. The surviving rats in the group given DMN (25 ppm) in the drinking water alone were killed at 26 weeks and it was found that 12 of 16 rats had developed liver tumors. In the group given DMN and cupric acetate (sc injections of 2 mg of Cu/kg of body weight once a week for 26 weeks), 7 of 22 rats developed liver tumors. The incidence of liver tumors in rats given DMN and cupric acetate was thus only about 40% of that in rats given DMN alone. No tumor was observed in the group given saline or cupric acetate alone. The thymidine incorporation into the liver DNA of rats was measured at 2 and 4 weeks after the start of the carcinogenicity experiment. The thymidine incorporation into the liver DNA of rats given DMN was significantly suppressed by the administration of cupric acetate. The methylation of liver DNA in rats given a single dose of DMN was also significantly suppressed by sc injection of cupric acetate; the formation of both O6-methylguanine and 7-methylguanine was reduced. This result suggests that sc injection of cupric acetate may have a suppressive effect on the initiation of carcinogenesis in the liver.

Studies on effects of forphenicinol on immune responses

The oral administration of forphenicinol, S-2-(3-hydroxy-4-hydroxymethylphenyl)glycine which was synthesized during the study of derivatives and analogs of forphenicine, augmented delayed-type hypersensitivity to sheep red blood cells and oxazolone in mice. The treatment with forphenicinol restored DTH in mice immuno-suppressed by cyclophosphamide to normal response. Forphenicinol neither augmented antibody-formation nor stimulated proliferation of lymphocytes in the presence or absence of lectins. Phagocytosis by peritoneal macrophages was enhanced by forphenicinol in vivo and in vitro. Forphenicinol was effective in increasing the production of CFU-C in the presence of colony stimulating factor and partially prevented the reduction of leucocyte counts caused by mitomycin C.