Nina Strzałkowska

Cathelicidins: family of antimicrobial peptides. A review

Cathelicidins are small, cationic, antimicrobial peptides found in humans and other species, including farm animals (cattle, horses, pigs, sheep, goats, chickens, rabbits and in some species of fish). These proteolytically activated peptides are part of the innate immune system of many vertebrates. These peptides show a broad spectrum of antimicrobial activity against bacteria, enveloped viruses and fungi. Apart from exerting direct antimicrobial effects, cathelicidins can also trigger specific defense responses in the host. Their roles in various pathophysiological conditions have been studied in mice and humans, but there are limited information about their expression sites and activities in livestock. The aim of the present review is to summarize current information about these antimicrobial peptides in farm animals, highlighting peptide expression sites, activities, and future applications for human and veterinary medicine.

Defensins: Natural component of human innate immunity

The widespread use of antibiotics has contributed to a huge increase in the number of resistant bacteria. New classes of drugs are therefore being developed of which defensins are a potential source. Defensins are a group of antimicrobial peptides found in different living organisms, involved in the first line of defense in their innate immune response against pathogens. This review summarizes the results of studies of this family of human antimicrobial peptides (AMPs). There is a special emphasis on describing the entire group and individual peptides, history of their discovery, their functions and expression sites. The results of the recent studies on the use of the biologically active peptides in human medicine are also presented. The pharmaceutical potential of human defensins cannot be ignored, especially considering their strong antimicrobial activity and properties such as low molecular weight, reduced immunogenicity, broad activity spectrum and resistance to proteolysis, but there are still many challenges and questions regarding the possibilities of their practical application.

Association of polymorphisms in exons 2 and 10 of the insulin-like growth factor 2 ( IGF2 ) gene with milk production traits in Polish Holstein-Friesian cattle

Insulin-like growth factor 2 (IGF2) is considered to be a regulator of post-natal growth and differentiation of the mammary gland. In the present work, associations of two single nucleotide polymorphisms in the bovine IGF2 gene with milk production traits were studied in dairy Holstein-Friesian cows: the already described g.8656C>T transition in exon 2 (RFLP-BsrI) and the newly found g.24507G>T transversion in exon 10 (RFLP-HaeIII), found by sequencing 273-bp exon 10 of the IGF2 gene in six individuals. Associations were analysed individually and in combination with the multi-trait repeatability test-day animal model. The CT/GT haplotype appeared to be associated with most of the milk traits studied (differences were significant at P < or = 0.001). The most frequent CT/GG haplotype seemed inferior to others in fat and protein content and daily yield of fat and protein but superior (together with the TT/GG genotype) when the daily milk yield is considered.

Twelve-year cohort study on the influence of caprine arthritis-encephalitis virus infection on milk yield and composition.

This long-term observational cohort study was carried out to evaluate the effect of caprine arthritis-encephalitis virus (CAEV) infection on the quantitative and qualitative characteristics of milk production in dairy goats. For this purpose, a dairy herd comprising both CAEV-infected and uninfected female goats was observed for 12 consecutive years. Records on daily milk yield, somatic cell count (SCC), and contents of the major milk components (fat, protein and lactose) were collected every month. In total, 3,042 records (1,114 from CAEV-positive and 1,928 from CAEV-negative animals) from 177 female goats were used for statistical analysis. The multi-trait repeatability test-day animal model using the derivative-free multivariate analysis package with the average information-REML method was applied to eliminate the influence of factors other than CAEV infection on milk production in goats. The statistical significance of the differences between estimates for seropositive and seronegative goats was evaluated using Students t-test. The effect of age of goats (parity) on their serological status was also estimated with the one-trait repeatability test-day model. The serological status of goats was linked to parity: the higher the parity, the greater the probability of CAEV infection. No significant differences between infected and uninfected goats with respect to daily milk yield and SCC were found. On the other hand, the milk of uninfected goats contained more total protein (3.40% vs. 3.35%), fat (3.69% vs. 3.54%), and lactose (4.30% vs. 4.25%) than the milk of infected goats. Even though these differences were highly significant, they were small when expressed numerically.

Influence of small ruminant lentivirus infection on cheese yield in goats

Three-year cohort study was carried out to investigate the influence of small ruminant lentivirus (SRLV) infection on cheese yield in goats. For this purpose records of milk yield, milk composition and cheese yield were collected in a dairy goat herd. Cheese yield was recorded as the amount of fresh cheese obtained from 1 kg milk. All goats were serologically tested for SRLV infection twice a year. The analysis included 247 records in total (71 for seropositive and 176 from seronegative individuals) and was carried out with the use of the four-level hierarchical linear model (α = 0·05). SRLV infection proved to be a statistically significant independent factor reducing cheese yield (P = 0·013)--when other covariates were held constant cheese yield was reduced by 4·6 g per each 1 kg milk in an infected goat compared with an uninfected goat. Other statistically significant covariates positively associated with cheese yield were protein contents, fat contents and the 3rd stage of lactation (P < 0·001 for all).

Effect of linseed, rapeseed, and vitamin E long term supplementation on the activity of the lysosomal enzymes in ostrich liver

Abstract The aim of the study was to assess the activity of lysosomal enzymes: aminopeptidases, including alanine aminopeptidase (AlaAP), leucine aminopeptidase (LeuAP), arginine aminopeptidase (ArgAP), and glycosidases, such as β-galactosidase (BGAL), β-glucuronidase (BGRD), β-glucosidase (BGLU), N-acetyl-β-hexosaminidase (HEX), α-glucosidase (AGLU) and α-mannosidase (MAN) in the liver of ostriches (n = 80) fed diet supplemented with linseed (4% and 8%) and rapeseed (5% and 10%), with low and high level of vitamin E. (40 and 100 mg). The results indicate that higher level of vitamin E or 4% linseed supplementation in ostrich diet generally increase the activity of glycosidase enzymes and decrease the activity of aminopeptidases in the liver. The 8% linseed and rapeseeds feeding in decreased the activity of AlaAP, LeuAP, and ArgAP and increased only the activity of BGLU.

Effects of replacing extracted soybean meal with rapeseed cake in corn grass silage-based diet for dairy cows.

The aim of the study was to assess the effects of partial replacement of soybean meal with a protein-equivalent amount of rapeseed cake in the diet on milking parameters and fatty acid (FA) composition of milk in dairy cows. Two groups of Holstein-Friesian cows, 8 each, consisting of randomised blocks were studied: a control group (C) was given a traditional high-protein supplement (extracted soybean meal) and the experimental group (E), had part of extracted soybean meal replaced with rapeseed cake. Dry matter intake and milk yield in both groups were not affected by the diet but milk fat percentage and yield were decreased in both groups. Rapeseed cake had no effect on milk acidity or on protein (including casein) and lactose contents. A lower concentration of urea in milk in E group indicated a proper ratio of protein to energy in the fodder. Health condition of mammary gland and indicators of metabolic profile were not affected by rapeseed cake supplementation. In E group, the share of atherogenic saturated fatty acids (FA) was reduced after 11 weeks: palmitic, by 26% and myristic, by 22%; moreover, as compared with control cows, the content of monounsaturated FA in milk increased by 44% after 3 weeks and by 68% after 11 weeks, t-18:1 and c-9 t-11 isomer of CLA increased about 2.5-fold after 11 weeks. In E group, the atherogenic index (AI) was significantly (P < 0.001) lower than in C (by 54% on average) and the decrease with time was considerable (by 29%, P < 0.001). Contents of odd- and branched- chain FA in milk were not significantly affected thus reflecting proper rumen function. Partial replacement of soybean meal with rapeseed cake in the diet of cows may improve both milking indices and FA profile of milk.

Morphological, densitometric and mechanical properties of pelvic limb bones in 14-month-old female ostriches (Struthio camelus)

Limited information on physiological characteristic of bones in ostrich skeleton are available, even though bone weaknesses in ostriches are commonplace. Thus, the aim of this study was to evaluate morphological, densitometric, and mechanical properties of pelvic limb long bones (femur, tibia, and tarsometatarsus) in 14-month-old female ostriches (Struthio camelus var. domesticus). After the slaughter procedure, all bones were isolated, cleaned of soft tissues, and bone weight and length were determined. Using dual energy X-ray absorptiometry (DEXA) bone mineral density (BMD) and bone mineral content (BMC) were determined. Volumetric bone mineral density (vBMD) and geometrical parameters of the bones were determined using the quantitative computed tomography (QCT) method. Maximum elastic strength and ultimate strength of the bones were determined using three-point bending test. Significant differences were revealed between morphological, densitometric, and mechanical properties of femur, tibia, and tarsometatarsus in female ostriches at the slaughter age of 14 months. Elaborated experimental model and determination of morphological, densitometric, and mechanical properties of femur, tibia, and tarsometatarsus in female ostriches may serve for further studies on metabolic regulation of skeletal system properties with environmental, physiological, dietary, pharmacological, and toxicological factors.

Oxidative stability of ostrich meat related to duration of linseed and lucerne supplementation to the bird's diet

Abstract The effect of dietary linseed and lucerne supplementation on the oxidative stability of ostrich meat expressed by changes in concentrations of malondialdehyde (MDA) and glutathione (GSH), and in activity of superoxide dismutase (SOD), was studied. The feeding regimens were as follows: C – control group, L – 4% supplement of linseed, L-L45, L-L55, L-L65, and L-L75 – 4% supplement of linseed and supplement of lucerne added to the birds’ diet at 45, 55, 65, and 75 kg b.w. The highest level of GSH was recorded in L-L65 group, whereas the highest activity of SOD was observed in C, L-L65 and L-L75 groups. Among all groups, the long-term linseed and lucerne supplementation reduced the antioxidant potential of ostrich meat, especially in L-L45 and L-L55 groups, which was reflected in the highest level of MDA and the lowest activity of SOD. Thus, the optimal results after linseed and lucerne supplementation with regard to ostrich meat oxidative stability were reported in groups L-L65 and L-L75, approximately three to four months prior to slaughter.

The Effect of Different Levels of Cu, Zn and Mn Nanoparticles in Hen Turkey Diet on the Activity of Aminopeptidases

The aim of the study was to estimate the influence of the different levels of Cu, Zn, and Mn nanoparticles on the activity of aminopeptidases in turkey. An experiment was carried out on 144 turkey hen Hybrid Converter. The birds were divided into groups given standard- and nanoparticle-supplementation of different level of copper (Cu 20, 10, 2 mg/kg), zinc (Zn 100, 50, 10 ppm), and manganese (Mn 100, 50, 10 ppm), covering respectively 100%, 50%, and 10% of the physiological demands for those minerals in the diet. The activity of aminopeptidases (alanyl: AlaAP, leucyl: LeuAP and arginyl: ArgAP) after supplementation of minerals was determined in the breast and thigh turkey muscle. The strongest effect of interaction among minerals supplementation form and dose on the activity levels of the aminopeptidases in thigh muscle was observed for nano-Cu already at the lowest dose of 2 mg/kg. In this dose (covering 10% of the birds’ demand) nano form of supplementation significantly increased the activity of Ala-, Leu-, and ArgAP (877, 201, and 719, respectively), compared to standard form of supplementation (461, 90.5, and 576, respectively). In turn, in breast muscle, after supplementation covering 10% of the demand with the nano-Cu, nano-Zn, and nano-Mn compared to the standard form, we did not observe any significant difference in the activity levels of any of the investigated aminopeptidases, except for AlaAP under Zn supplementation. Supplementation with the 20 mg/kg of Nano-Cu (100% of demand) and with 10 mg/kg of Nano-Cu (50% of demand) inhibited the activity of all of the three aminopeptidases in thigh muscle. Supplementation of the minerals in nano form into the diet, especially of Cu and Zn in the dose covering 10% of the demand is relevant to maintain homeostasis in turkey muscles, as indicated by the activity of the aminopeptidases.