59 research outputs found
Humoral and Cellular Response of Pheasants Vaccinated against Newcastle Disease and Haemorrhagic Enteritis
The purpose of the experiment was to define whether and to what extent can prophylactic vaccinations against Newcastle disease (ND) and haemorrhagic enteritis (HE) affect the humoral and cellular response in pheasants. The evaluation of humoral response was performed on a basis of agglutinin titre after administered antigen and the cellular immunity index was the delayed type hypersensitivity (DTH) reaction. The pheasants were prophylactically vaccinated against Newcastle Disease (ND) on the 1st, 28th and 56th day of life. Moreover, on the 49th day of life, part of the birds was given in the drinking water a vaccine containing the HEV (Haemorrhagic Enteritis Virus). Fourteen days after the HEV vaccination, the birds were intravenously given 0.5 ml of the 10% SRBC (sheep red blood cells) suspension. Simultaneously with the SRBC administration the delayed hypersensitivity test was performed by intradermal administration of phytohaemagglutinin (PHA). It was shown that in pheasants vaccinated with NDV and additionally with HEV, the specific agglutinin anti-SRBC titre was significantly (p < 0.05) lower than in birds vaccinated against ND only. It also appeared that, the antibodies resistant to 2-mercaptoethanol were 43% of the total pool of specific anti-SRBC antibodies in the NDV vaccinated birds, whereas in birds vaccinated also with HEV they were 75%. No significant differences were found in the DTH test. Only in the HEV vaccinated pheasants the tendency to increase the wing index value was noted. The results confirm the observations concerning immunosuppressive effects of simultaneous vaccinations. They also indicate that overloading the pheasants with many antigens (ND and HEV vaccination) may weaken the humoral response to administered SRBC
Remote automatic selection of cows for milking in a pasture-based automatic milking system
ABSTRACT New Zealand pastoral dairy farming presents unique challenges for combining automatic milking systems (AMS), including long walking distances, large herds, year round pasturing and a predominately fresh pasture diet. This paper describes a system designed to minimise walking, maximise the efficiency of AMS utilisation and enable control of individual cow milking frequency by remotely selecting cows for milking up to 400 m from the dairy. Cows report to a selection unit (SU) located in the centre of a block of pasture and linked via raceways to the AMS. Entry is via one-way gates and exit via a computer controlled drafting gate, which directs the cow either to the dairy or the paddock depending on time since last milking. A communication cable connects the SU to the AMS server in the dairy. Cows wear an electronic identification device. Water and pasture access act as incentives for cows to enter the SU. Cows readily learned to use the SU and were observed visiting the unit at every hour over 24 hours. Twenty-seven cows were assigned to either a 6h or 12h minimum milking interval (MMI). On average, cows visited the SU 4.5 and 5.5 times/d for the 6h MMI and 12h MMI groups, respectively, and achieved a milking frequency of 1.9 and 1.4 milkings/d, respectively. Results showed that milking frequency can be controlled via a system for remotely selecting cows for milking and that access to fresh pasture is a strong factor in motivating cow traffic through the SU
The Phylogenetic Structure of Reptile, Avian and Uropathogenic Escherichia coli with Particular Reference to Extraintestinal Pathotypes
The impact of the Gram-negative bacterium Escherichia coli (E. coli) on the microbiomic and pathogenic phenomena occurring in humans and other warm-blooded animals is relatively well-recognized. At the same time, there are scant data concerning the role of E. coli strains in the health and disease of cold-blooded animals. It is presently known that reptiles are common asymptomatic carriers of another human pathogen, Salmonella, which, when transferred to humans, may cause a disease referred to as reptile-associated salmonellosis (RAS). We therefore hypothesized that reptiles may also be carriers of specific E. coli strains (reptilian Escherichia coli, RepEC) which may differ in their genetic composition from the human uropathogenic strain (UPEC) and avian pathogenic E. coli (APEC). Therefore, we isolated RepECs (n = 24) from reptile feces and compared isolated strains’ pathogenic potentials and phylogenic relations with the aforementioned UPEC (n = 24) and APEC (n = 24) strains. To this end, we conducted an array of molecular analyses, including determination of the phylogenetic groups of E. coli, virulence genotyping, Pulsed-Field Gel Electrophoresis-Restriction Analysis (RA-PFGE) and genetic population structure analysis using Multi-Locus Sequence Typing (MLST). The majority of the tested RepEC strains belonged to nonpathogenic phylogroups, with an important exception of one strain, which belonged to the pathogenic group B2, typical of extraintestinal pathogenic E. coli. This strain was part of the globally disseminated ST131 lineage. Unlike RepEC strains and in line with previous studies, a high percentage of UPEC strains belonged to the phylogroup B2, and the percentage distribution of phylogroups among the tested APEC strains was relatively homogenous, with most coming from the following nonpathogenic groups: C, A and B1. The RA-PFGE displayed a high genetic diversity among all the tested E. coli groups. In the case of RepEC strains, the frequency of occurrence of virulence genes (VGs) was lower than in the UPEC and APEC strains. The presented study is one of the first attempting to compare the phylogenetic structures of E. coli populations isolated from three groups of vertebrates: reptiles, birds and mammals (humans).</jats:p
Isospin effects studied with the CHIMERA detector at 35 Mev/nucleon
The yield of light charged particles and intermediate mass fragments is studied for the neutron-rich, 124Sn+64Ni, and neutron-poor, 112Sn+58Ni, reactions at 35MeV/nucleon as a function of the impact parameter. Our main observations are: (i) The yields of 1H, 3He and 4He particles in the neutron-poor system are enhanced with respect to the neutron-rich system and the yield of 3H is suppressed at all impact parameters, (ii) The ratio of 3H to 3He yield is three times larger for neutron poor system, (iii) The N/Z
ratio of the emitted intermediate-mass fragments shows dependence on the isospin of the system, (iv) The neutron richness of detected intermediate mass fragments depends strongly on their rapidity. The gross features of the experimental data are reproduced by quantum molecular dynamics model calculations
Evaluation of the immunogenicity of Campylobacter jejuni CjaA protein delivered by Salmonella enterica sv. Typhimurium strain with regulated delayed attenuation in chickens
Changing trends in mastitis
<p>Abstract</p> <p>The global dairy industry, the predominant pathogens causing mastitis, our understanding of mastitis pathogens and the host response to intramammary infection are changing rapidly. This paper aims to discuss changes in each of these aspects. Globalisation, energy demands, human population growth and climate change all affect the dairy industry. In many western countries, control programs for contagious mastitis have been in place for decades, resulting in a decrease in occurrence of <it>Streptococcus agalactiae </it>and <it>Staphylococcus aureus </it>mastitis and an increase in the relative impact of <it>Streptococcus uberis </it>and <it>Escherichia coli </it>mastitis. In some countries, <it>Klebsiella </it>spp. or <it>Streptococcus dysgalactiae </it>are appearing as important causes of mastitis. Differences between countries in legislation, veterinary and laboratory services and farmers' management practices affect the distribution and impact of mastitis pathogens. For pathogens that have traditionally been categorised as contagious, strain adaptation to human and bovine hosts has been recognised. For pathogens that are often categorised as environmental, strains causing transient and chronic infections are distinguished. The genetic basis underlying host adaptation and mechanisms of infection is being unravelled. Genomic information on pathogens and their hosts and improved knowledge of the host's innate and acquired immune responses to intramammary infections provide opportunities to expand our understanding of bovine mastitis. These developments will undoubtedly contribute to novel approaches to mastitis diagnostics and control.</p
The effects of subcutaneous and intraocular administration of class B ODN CpG in chicken on the expression of TLR21, IFN-gamma and IL-1Beta
The synthetic unmethylated oligodeoxynucleotides with CpG motifs (CpG ODN) were shown to activate Toll-like receptor 21 (TLR21) and stimulate the innate and adaptive immune system. In this study we tested the expression of TLR21, interferon (IFN)-γ and interleukin (IL)-1β mRNA in the blood after subcutaneous and intraocular application of the class B CpG ODN in chicken. The relative expression of mRNA of TLR21, IFN-γ and IL-1β were quantified at 3, 6, 12, 24 and 72 h post-stimulation. The study revealed that IFN-γ mRNA expression was significantly upregulated 12 h after subcutaneous stimulation with a high and low dose of ODN CpG, whereas the IL-1β mRNA expression levels were significantly upregulated 3 and 72 h after subcutaneous administration. After intraocular administration, the IL-1β mRNA levels were the highest at 24 h post-application, albeit not specifically. This data indicates that class B CpG ODN has the ability to induce TLR21 response in blood when administered parenterally in chicken. In contrast, intraocular administration of CpG ODN was not able to produce a significant increase in cytokine mRNA expression in blood. The data suggest that additional stimulus, e.g. the antigen, may be needed on the site of mucosal administration to activate systemic immune response
Carp deheaders evolution
Celem artykułu jest przedstawienie wyników badań własnych
i analiz publikacji, wyjaśniających przyczyny niższej wydajności
technologicznej maszynowego odgławiania karpi, niż uzyskiwanej
przy pracy ręcznej. Na ich podstawie prototyp odgławiarki,
w której stosowane jest oszczędne cięcie po łuku, wyposażono
w laserowy wskaźnik ułatwiający pozycjonowanie
ryby względem noża odgławiającego, przez co uzyskiwane wydajności
porównywalne są z ręcznym odgławianiem.The paper presents results of scientific researches and analysis
of professional literature on a yield of carp mechanical
deheading. Basing on these results the prototype of deheading
machine with circular cut and laser indicator for precise
fish positioning was designed. Application of laser indicator
increased deheading yield to hand deheading standard
Antimicrobial resistance of thermophilic Campylobacter spp. isolated from cattle in Poland
Campylobacter species are among the most frequently identified bacterial causes of human gastroenteritis. Because Campylobacter spp. harbored by cattle can be transmitted to humans, in this study we investigated antimicrobial resistance of thermophilic Campylobacter isolated from cows. Our study included 150 strains of Campylobacter (143 strains of C. jejuni and 7 strains of C. coli) isolated from cows in South-Western Poland. The minimal inhibitory concentration (MIC) to ciprofloxacin, erythromycin, gentamicin and tetracycline were determined using the agar dilution methodology. All strains of C. coli were susceptible to all four drugs studied. The most frequently detected resistance of C. jejuni was to ciprofloxacin (26 strains 18.2%). Resistance to tetracycline was observed in 5 strains (3.5%). All strains of C. jejuni were susceptible to erythromycin and gentamicin
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