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Open access

Barbara Kazuń, Joanna Małaczewska, Krzysztof Kazuń, Joanna Żylińska-Urban and Andrzej K. Siwicki

Abstract

Introduction: Immune-potentiating functions of Lactobacillus plantarum strains in the common carp were evaluated.

Material and Methods: Fourteen days of feeding fish dry diet supplemented with the bacteria provided parameters of nonspecific humoral immunity (lysozyme, ceruloplasmin, γ-globulin, total protein levels, and serum bactericidal activity) and cellular immunity (pinocytosis, respiratory burst activity, and potential killing activity of organ phagocytes), as well as the proliferative response of organ lymphocytes stimulated with mitogens. The resistance of fish to infection with Aeromonas hydrophila was also determined.

Results: Dietary supplementation with L. plantarum had a substantial influence on the activity of organ phagocytes, especially the potential killing activity of head kidney cells. A significant increase in the proliferative activity of LPS-stimulated B lymphocytes and in the levels of γ-globulins and total protein was observed. The supplemented diet conveyed higher resistance than the control diet as the cumulative fish mortalities after infection with A. hydrophila were 65% and 85%, respectively.

Conclusion: The results indicate that dietary supplementation with L. plantarum stimulates the antibacterial resistance of common carp and may reinforce defence against bacterial infections, but further studies need to be conducted.

Open access

Monika Olszewska-Tomczyk, Izabella Dolka, Edyta Świętoń and Krzysztof Śmietanka

Abstract

Introduction: Genotype VI of avian avulavirus 1 (AAvV-1) has pigeons and doves as its reservoir and is often termed pigeon paramyxovirus type-1 (PPMV-1). The pathogenesis of PPMV-1 infections in poultry is largely obscure. It is known that PPMV-1 requires a series of passages in chickens before it becomes adapted to gallinaceous poultry.

Material and Methods: Changes in the genome of PPMV-1 were analysed after serial passages in specific pathogen free (SPF) chickens, using high-throughput sequencing. Additionally, histopathological lesions induced by PPMV-1 in experimentally inoculated pigeons, chickens, and turkeys were evaluated.

Results: Following six passages of PPMV-1 in chickens, 10 nonsynonymous substitutions were found including one (in the NP protein) which dominated the genetic pool of viral quasispecies. Histopathological changes induced by the post-passage PPMV-1 strain were more prominent than changes wrought by the pre-passaged PPMV-1 strain and the lesions were most intense in pigeons followed by chickens and turkeys.

Conclusion: PPMV-1 is highly adapted to pigeons and passaging through chickens results in the acquisition of novel amino acids in the polymerase complex, which may alter the pathogenic potential of the virus.

Open access

Małgorzata Kwaśnik, Ilona M. Góra, Jan F. Żmudziński, Jerzy Rola, Mirosław P. Polak and Wojciech Rożek

Abstract

Introduction: Traditionally, evolutionary analysis of equine influenza virus (EIV) is based on the HA gene. However, the specificity of the influenza virus enables the classification of viral strains into different phylogenetic groups, depending on the gene being analysed. The aim of the study was to analyse phylogenetic paths of EIV based on M gene with reference to the HA gene.

Material and Methods: M gene of Polish isolates has been sequenced and analysed along with all M sequences of EIV available in GenBank database. Phylogenetic analysis was performed using BioEdit, ClustalW, and MEGA7 softwares.

Results: The clustering of the strains isolated not only from Asia but also from Europe into one common Asian-like group of EIV was observed. Twelve nucleotide substitutions in the M gene of strains from the Asian-like group were crucial for the evolutionary analysis. We also observed homology in the M gene of the Asian-like and H7N7 strains.

Conclusions: M gene specific for the Asian-like group is present in strains recently isolated in Europe and Asia, which were classified previously in the Florida 2 clade based on HA. Therefore, Asian-like group does not seem to be assigned to a specific geographical region. Traces of H7N7 strains in more conservative genes like M of some contemporary EIV strains may indicate the link between the old phylogenetic group and recent H3N8 strains. Analysis of conservative genes may be more useful in tracking the direction of virus evolution than in the genes where the high variability rate may blur the original relationships.

Open access

Krzysztof Szkucik, Monika Ziomek, Waldemar Paszkiewicz, Łukasz Drozd, Michał Gondek and Przemysław Knysz

Abstract

Introduction: The objective was to determine the content of fatty acids in edible snail fat by snail species, collection site, and processing stage.

Material and Methods: The research material comprised 180 edible fat samples from the three genera of edible snails collected in Poland: free-living Helix pomatia (HP) and two cultivated Cornu subspecies: C. aspersa maxima (CAM) and C. aspersum aspersum (CAA). All snails came from the Greater Poland and Lower Silesian Provinces: HP from their natural habitat and CAM and CAA from heliciculture farms. The studies focused on the raw meat, cooked meat, and frozen meat processing stages. Fatty acid (FA) profiles were determined by the gas chromatography method.

Results: Helix pomatia fat showed a higher saturated fatty acid (SFA) content, whereas the fat of Cornu genus snails had a higher unsaturated fatty acid (UFA) component, i.e. monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA). Thermal processing of snail meat increased all the determined SFA and decreased all the PUFA values, and increased the content of C18:1, C20:1, and C22:1 acids in the MUFA group. The material collection site had limited impact on FA content as differences were noted only in levels of C18:1, C18:2 n6, and C20:5. The differences pertained only to the fat of farmed snails of the Cornu genus.

Conclusion: Due to the high content of UFA and a favourable ratio of n6:n3 acids and PUFA:SFA, snail fat can be regarded as nutritionally valuable.

Open access

M. Fedorová, R. Nemcová, D. Mudroňová, E. Styková, M. Brudňáková and K. Reiffová

Abstract

This study investigated a possible relationship between exopolysaccharides (EPS) production and the resistance to bile salts and low pH in intestinal strains of Lactobacillus reuteri. The strains displayed a mucoid phenotype, when grown in the presence of 10 % sucrose. Scanning electron microscopy (SEM) revealed strands of exopolysaccharide linking neighbouring cells. The strains (except L. reuteri B1/1) produced EPS in the range from 15.80 to 650.70 mg.l−1. The strains were tested for tolerance to bile salts (0.15; 0.3 %) and low pH (1.5—2.0—2.5—3.0). The survival rate, after the treatment with artificial gastric and intestinal juices, was determined by flow cytometric analysis. The strains of L. reuteri that produced 121—650 mg.l−1 of EPS showed a significantly higher tolerance (P < 0.001) to the gastric juice at pH 3 and 2.5, throughout the entire exposure time, in comparison to the strains that produced less than 20 mg.l−1 of EPS. L. reuteri L26, with the highest production of EPS, exhibited the highest survival rate (60 %) at pH 2 after the 120 minutes of in-cubation and was able to tolerate pH 1.5 for 30 minutes. Higher production of EPS significantly (P < 0.001) increased the strains’ tolerance against the intestinal juice in the presence of 0.15 and 0.3 % bile salts and was time dependent. L. reuteri L26 showed the highest tolerance (P < 0.001) against 0.3 % bile salts. This investigation revealed a positive correlation between the EPS production and the resistance of intestinal L. reuteri to the stress conditions of the gastrointestinal tract (GIT).

Open access

Agnieszka Kędrak-Jabłońska, Sylwia Budniak, Anna Szczawińska, Monika Reksa, Marek Krupa and Krzysztof Szulowski

Abstract

Introduction: The aim of the study was the application and evaluation of real-time PCRs based on the fluorescence of SYBR Green I intercalating dye for the detection of three Bacillus anthracis genes in contaminated liver and blood samples. The goals for detection were rpoB gene as a chromosomal marker, pag gene located on plasmid pXO1, and capC gene located on plasmid pXO2.

Material and Methods: Five B. anthracis strains were used for the experiments. Additionally, single strains of other species of the genus Bacillus, i.e. B. cereus, B. brevis, B. subtilis, and B. megaterium, and strains of six other species were used for evaluation of the specificity of the tests. Three SYBR Green I real-time PCRs were conducted allowing confirmation of B. anthracis in the biological samples.

Results: The observation of amplification curves in real-time PCRs enabled the detection of the chromosomally encoded rpoB gene, pag gene, and capC gene of B. anthracis. The specificity of the tests was confirmed by estimation of the melting temperature of the PCR products. The sensitivity and linearity of the reactions were determined using regression coefficients. Strains of other microbial species did not reveal real-time PCR products.

Conclusion: All real-time PCRs for the detection of B. anthracis in biological samples demonstrated a significant sensitivity and high specificity.

Open access

R. A. Ajadi, J. L. Sanni and E. L. Sobayo

Abstract

This study compares the coxofemoral parameters used for the detection of hip dysplasia in humans with Norberg angles in Boerboel dogs. Twenty adult Boerboel dogs of both sexes (mean weight: 54.0 ± 7.54 kg) were used. They were premedicated with Xylazine (0.5 mg.kg−1) and induced with a propofol (4 mg.kg−1) injection. Extended antero-posterior radiographs of the hip were obtained with a digital X-ray machine. Linear Femoral Overlap (LFO), Norberg Angle (NA), Sourcil Sector Angle (SSA), Center Edge Angle (CEA) and Acetabular Index Angle (AIA) were determined. The inter- and intra-observer variability were calculated from inter- and intra- class correlation coefficient using the analysis of variance (ANOVA). Fischer’s exact test was used to define the statistically significant difference in measurements between sexes and hip dysplasia status. A significant difference was set at P < 0.05. The intra-observer agreement was high for NA and CEA, moderate for AIA, but low for SSA and LFO, while inter-observer agreement was high for NA and CEA, moderate for LFO and AIA, but very low for SSA. There was no significant (P < 0.05) difference in the measured parameters between male and female Boerboels, however, NA and CEA were significantly (P < 0.05) lower in Boerboels with hip dysplasia than those with normal hips. The CEA does not have advantage over NA for radiographic screening of dogs with hip dysplasia.

Open access

Joanna Małaczewska, Edyta Kaczorek-Łukowska, Monika Szymańska-Czerwińska, Wojciech Rękawek, Roman Wójcik, Krzysztof Niemczuk and Andrzej Krzysztof Siwicki

Abstract

Introduction: Coxiella (C.) burnetii, the aetiological agent of Q fever, is able to modulate the macrophage/T-lymphocyte axis in an infected organism and impair synthesis of monokines and lymphokines.

Material and Methods: The purpose of this research was to determine the levels of the cytokines that play a key role in the response to C. burnetii antigens (IL-1β, IL-2, IL-6, IL-10, IFN-γ and TNF-α) in the serum of animals originating from an infected herd prior to vaccination (day 0) and at 1, 7, and 21 days afterwards.

Results: The vaccination of animals did not affect the production of IL-6, IL-1β, or IL-2. The serum levels of these cytokines were too low to measure in most of the samples. The initial levels of TNFα, IFNγ, and IL-10 were higher in seropositive than in seronegative animals, although significant differences between seropositive shedders and seropositive nonshedders appeared only in the levels of IFNγ and IL-10. Additionally, the course of the post-vaccination response concerning these two cytokines was different among seronegative nonshedders, seropositive nonshedders, and seropositive shedders.

Conclusion: It seems that analysis of the IFNγ and IL-10 concentrations in animal blood serum may have some practical value in an assessment of the health status of seropositive animals and post-vaccination response.

Open access

R. Szabóová, Z. Faixová, Z. Maková and E. Piešová

Abstract

The mucus layer of the intestinal tract plays an important role of forming the front line of innate host defense. Recent studies have suggested that the involvement of feeding natural additives on protection/prevention/promotion of mucus production in the intestinal environment is beneficial. The goblet cells continually produce mucins for the retention of the mucus barrier under physiological conditions, but different factors (e. g. microorganisms, microbial toxins, viruses, cytokines, and enzymes) can have profound effects on the integrity of the intestinal epithelium covered by a protective mucus. The intestinal mucus forms enterocytes covered by transmembrane mucins and goblet cells produce by the secreted gel-forming mucins (MUC2). The mucus is organized in a single unattached mucus layer in the small intestine and in two mucus layers (inner, outer) in the colon. The main part of the review evaluates the effects of natural additives/substances supplementation to stimulate increased expression of MUC2 mucin in the intestine of animals.

Open access

Ya-Li Liu, Yao-Zhong Ding, Jun-Fei Dai, Bing Ma, Ji-Jun He, Wei-Min Ma, Jian-Liang Lv, Xiao-Yuan Ma, Yun-Wen Ou, Jun Wang, Yong-Sheng Liu, Hui-Yun Chang, Yong-Lu Wang, Qiang Zhang, Xiang-Tao Liu, Yong-Guang Zhang and Jie Zhang

Abstract

Introduction: The extremely high genetic variation and the continuously emerging variants of foot-and-mouth disease virus (FMDV) of Southern African Territory (SAT) serotypes including SAT1, SAT2, and SAT3 make it necessary to develop a new RT-PCR for general use for monitoring viruses based on the updated genome information.

Material and Methods: A FMDV SAT-D8 one-step RT-PCR was established based on the 1D2A2B genes of the SAT serotype viruses with a multiplex primer set. FMDV A, O, C, and Asia 1 serotypes, other vesicular disease viruses, inactivated SAT viruses, and 125 bovine, ovine, caprine and porcine tissue samples collected from the Chinese mainland were included for evaluating the assay.

Results: The new RT-PCR was proven to be specific without cross-reactions with Eurasian FMDV, swine vesicular disease virus (SVDV), Seneca valley virus (SVV), or other common viral pathogens of cattle, sheep, goat, and pig. An around 257 bp-sized amplicon clearly appeared when the inactivated SAT viruses were detected. However, all 125 samples collected from FMDV-susceptible animals from the Chinese mainland which has not known SAT epidemics showed negative results.

Conclusions: A FMDV SAT-D8 one-step RT-PCR is a promising method for primary screening for FMDV SAT serotypes.