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Fowl adenovirus (FAdV) is distributed worldwide and causes economic losses in the poultry industry. The objectives of this study were to determine the hexon and fiber gene changes in an attenuated FAdV isolate from Malaysia in specific pathogen-free chicken embryonated eggs (SPF CEE) and its infectivity in commercial broiler chickens. SPF CEE were inoculated with 0.1 mL FAdV inoculum via the chorioallantoic membrane (CAM) for 20 consecutive passages. The isolate at passage 20 (E20), with a virus titer of 10(8.7)TCID₅₀/mL (TCID₅₀, 50% tissue culture infective dose), was inoculated (0.5 mL) into one-day-old commercial broiler chicks either via oral or intraperitoneal routes. The study demonstrated that 100% embryonic mortality was recorded from E2 to E20 with a delayed pattern at E17 onwards. The lesions were confined to the liver and CAM. Substitutions of amino acids in the L1 loop of hexon at positions 49 and 66, and in the knob of fiber at positions 318 and 322 were recorded in the E20 isolate. The isolate belongs to serotype 8b and is non-pathogenic to broiler chickens, but it is able to induce a FAdV antibody titer. It appears that molecular changes in the L1 loop of hexon and the knob of fiber are markers for FAdV infectivity.
Subject(s)
Adenoviridae , Amino Acids , Chickens , Chorioallantoic Membrane , Eggs , Fowl adenovirus A , Liver , Malaysia , Mortality , Ovum , Poultry , Serogroup , Specific Pathogen-Free Organisms , Viral LoadABSTRACT
Objective@#To investigate the abnormalities of the blood system in landfill workers.@*Methods@#A cohort study was conducted for 224 landfill workers who were followed up for 6 consecutive years with abnormal routine blood test results and a low platelet count as the outcome events. The life-table method was used to analyze the incidence rates of these two outcome events, and the incidence rates were compared between first-and second-line workers.@*Results@#A total of 71 workers had abnormal routine blood test results, among whom 29 had abnormal leukocyte count, 14 had abnormal erythrocyte count, 40 had abnormal platelet count, 17 had abnormal hemoglobin, and 29 had a reduction in platelet count. For these landfill workers, the 6-year abnormal rate of routine blood test results was 43.2%, and the incidence rate of low platelet count within 6 years was 13.5%. The first-line workers had a significantly lower abnormal rate of routine blood test results than the second-line workers (P=0.020) , and the relative risk of abnormal routine blood test results in the first-and second-line workers was 0.592. There was no significant difference in the incidence rate of low platelet count between the two groups of workers (P≥0.05) .@*Conclusion@#The landfill has an adverse effect on the blood system of landfill workers, and the second-line workers have greater impairment than the first-line workers.
ABSTRACT
In this study, a Specific Pathogen-Free (SPF) Bama miniature pig herd was established.The standards for breeding experimental pigs, genetic test and microbiological quality control had been drafted.The local standards of Heilongjiang province SPF technical specifications for microbiological monitoring of pigs had been formulated.The genetic and microbiological quality criterion had been used to control of the SPF pig herd.Classical swine fever virus (CSFV) and highly pathogenic porcine reproductive and respiratory syndrome virus (PRRSV) infection models of Bama miniature pigs were established, especially the infection miniature pig model of PRRSV was used to evaluated commercially vaccine.The comparison of the cytokine homology between Bama miniature pigs and domestic pigs showed that the Bama miniature pigs can be used to instead of domestic pigs as an ideal experiental animal.At present the SPF Bama miniature pig colonies have been widely used to study the mechanism of prevention and pathogenic in the classical swine fever virus, porcine reproductive and respiratory syndrome virus and porcine transmissible gastroenteritis virus and porcine circovirus and so on.The completion of the project solved the bottleneck problem of the experimental pig usage which provided a new ideal experimental animal for animal disease and life science research.
ABSTRACT
The term“specific pathogen free” ( SPF) implies the bioexclusion of a defined list of organisms that can cause disease in a host.Due to many different factors including animal source, vivarium layout, microbiological history, engineering standards, operation practice, and experimental needs, the bioexclusion list tends to be specific for many institutions using live animals in biomedical research.As such, the design and implementation of institution-specific health monitoring program can also vary based on needs.By comparison, laboratory animal producers and users in China are subject to GB regulations which have established a national bioexclusion list based on animal health categories, as well as set detailed engineering standards for vivarium operations based on specific animal health profiles.In addition to summarizing the SPF list of major rodent vendors in North America, the purpose of this article is to bring attention to the different factors animal users should take into consideration when evaluating one ’ s own bioexclusion list and designing institution-specific health monitoring program for laboratory mice and rats, in order to assure animal colony health and scientific integrity.
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Objective Giardia lamblia is an important pathogen of zoonosis giardiasis , it poses a potential threat to the quality of SPF (specific pathogen-free) laboratory animals cannot be ignored.The aim of this study is to establish the method of rapid diagnosis of Giardia lamblia, and analyze the test results of 516 batches form 17 manufactures.Methods Direct microscopy, Giemsa-fast staining and multiplex polymerase chain reaction (multiplex PCR) were applied to detect Giardia lamblia.Results Numerous of Giardia lamblia trophozoites and cysts were detected in SPF laboratory animals by using direct microscopy and Giemsa-fast staining, and multiplex PCR were performed to identify 18S rDNA,β-giardin, TPI and GDH genes of DNA extracted from these trophozoites and cysts identified Giardia lamblia.Direct microscopy, Giemsa-fast staining, and multiplex PCR methods can be used to detect Giardia lamblia.Of the 2562 SPF laboratory animals studied, 22.9%(586/2562) were positive for Giardia lamblia.Conclusions Direct microscopy , Giemsa-fast staining , and multiplex PCR were effective techniques with high sensitivity and specificity for rapid diagnosis of Giardia lambliain.It is not satisfactory that the results of Giardia lamblia examination in 516 batches form 17 manufactures failed to meet the requirements 100%.
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Objective To understand the genetic background of the specific pathogen-free Yorkshire and Landrace pigs, imported from Canada by Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences.Methods The population genetics were investigated by using 19 pairs of microsatellite primers.Results In the Yorkshire pigs and Landrace pigs, 84 and 89 alleles, respectively, were detected at 19 microsatellites loci.The average polymorphic informa-tion content and mean heterozygosity in the Yorkshire pigs were 0.5271 and 0.5877, and in the Landrace population were 0.5652 and 0.6066, respectively.Because of the significant ( P<0.01) differences of alleles in different loci such as S0155,S0143,S0178,Sw857 and Sw936, it made them possible to be used to identify Yorkshire and Landrace pigs′breed. F-statistics showed that the differentiation within the population was small and genetic structure was stable.Conclusions Compare with the domestic pedigree large White and Landrace pigs, the SPF pedigree pigs imported from Canada are more stable in genetic structure, and can be used as laboratory animal models in animal science research.
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Resultados confiables y económicos solo son obtenidos cuando los animales de experimentación son aislados de factores ambientales y biológicos, implantándose en el biomodelo una microbiota normal, lejos de la presencia de microorganismos patógenos. El objetivo de la investigación fue obtener curieles libre de patógenos específicos por cesárea aséptica, mantenidos en aisladores y alimentados con dietas estériles. Se realizaron 26 histerectomías. Los animales fueron alimentados con una fórmula modificada (L-477) en forma de papilla hasta los 21 días y permanentemente después la C-484 sólida y granulada, esterilizadas a 121oC/20 minutos o a 1,5Mrad. Además fueron suplementados con vitamina C y B1. El forraje o heno fue consumido a partir de la primera generación. La microbiota gastrointestinal se administró por vía oral en 0,5 ml de una dilución de 10-6/g de contenido de la porción final del íleon, ciego y principio del colon de curieles, a las 24 y 48 horas del nacimiento. Se utilizó para el monitoreo microbiológico caldo Tioglicolato, caldo Triptona Soya y caldo Saboraud incubados aeróbicamente a temperatura de 55, 37 y 25oC respectivamente. Se obtuvieron 51 neonatos. La mortalidad más alta se registró entre los primeros 10 días de edad (58,8%). Se lograron 12 animales (3 machos y 9 hembras), 6 de las hembras se reprodujeron aproximadamente a los 9 meses de edad, lográndose 11 crías por parto normal. La metodología aplicada permitió obtener curieles libres de Salmonella sp, Pasteurella sp, Streptococcus del tipo A y C, Bordetella bronchiseptica, Toxoplasma gondii, Virus Sendai y parásitos internos y externos.
Confidence and economics results are only obtained when the animals are isolated of the environmental and biological factors, that could interfere the course of from investigation and when is being established in them, a normal microflora balanced far from the presence of pathogen microorganisms. They were accomplished 26 histerectomies. The animals were fed with a modified formula of L-477 in the form of porridge until 21 days of age and permanently after with the C-484 solid and granulated, sterilized at 121oC/20 minutes or 1,5Mrad. The forage or hay was consumed by the first generation since the 6 months of age. The gastrointestinal flora was administered by oral route with 0,5 ml of a dilution of 10-6/g of the contents of the ileum final portion, cecum and first part of the colon of conventionalized Dunkin Hartley guinea pigs, at 24 and 48 hours born. It was used for microbiological bacteria monitoring Thioglycolate broth, Tryptic Soy broth and Sabouraud broth incubated aerobically at temperatures of 55, 37 and 25oC respectively. There were obtained 51 newborns. The highest mortality was registered during the first 10 days of age (58,8%). There were archieved 12 animals: 9 female and 3 males. 6 of the female were reproduced approximately at 9 months of age and were archieved 11 normal delivery sucklings. There were obtained guinea pigs free of the followings specific pathogens: Salmonella sp., Pasteurella sp., Streptococcus of the group A y C. Bordetella bronchiseptica, Toxoplasma gondii, Sendai Virus, beside internal and external parasites.
Subject(s)
Diet Therapy , Hysterectomy , Insulator Elements , Specific Pathogen-Free Organisms , Diet , Host-Pathogen InteractionsABSTRACT
We analyzed 72 items related to serum biochemistry and hematology in 85 specific pathogen-free (SPF) Seoul National University (SNU) miniature pigs aged 1- to 36-months which originated from a Minnesota miniature pig. Almost all examined items were similar between male and female pigs. However, some items such as Cr level, B/C ratio, C.R.F, LDH, LAP and T4 were significantly different between male and female pigs (P<0.05). Thirty four examined items showed age-related changes, and the significant changes were observed in animals less than six months old. The values for BUN, K, uric acid, Ca, Ca++, and Pi were significantly higher in pigs younger than six months of age, which might reflect poor kidney function in young pigs. Additionally, TIBC, UIBC and RDW were significantly higher in young pigs, and RBC, Hb, HCT, MCHC and MCV were significantly lower in young pigs, thus indicating a similar physiology of iron deficiency anemia. These age-related specific phenotypes seemed to be normal, but it should be considered in the long-term experiment using the young pigs. In conclusion, in this study, we defined the normal reference intervals for SPF SNU miniature pigs, and we also determined that there are some physiological differences between the pig genders and ages. This study provides fundamental data for use in experiments involving SPF SNU miniature pigs.