Top marine predators present high mercury concentrations in their tissues due to biomagnification in the marine food chain. This study reports mercury (Hg) and selenium (Se) status, and the Hg:Se ...molar ratio assessment in bottlenose (Tursiops truncatus), striped (Stenella coeruleoalba) and Risso's dolphins (Grampus griseus). Total Hg and Se concentrations were determined in muscle, liver, kidney, lung, spleen, adipose tissue and skin collected from 186 specimens stranded in the Croatian part of Adriatic Sea from 1995 to 2014. Total Hg concentrations in tissue samples ranged from 0.001 in the spleen to 2238 mg/kg wet weight in liver. Se concentrations in dolphin samples ranged from 0.010 to 2916 mg/kg ww. Minimum Se concentration was found in muscle and maximum Se concentration were found in liver of bottlenose dolphin. Hg and Se levels in Risso's dolphins showed higher concentrations in all tissues in comparison to bottlenose and striped dolphins. Significant and positive correlations were observed between age and Hg concentrations (P < 0.05). In 66.6 % of Risso's, 15.3 % of bottlenose dolphins and one stranded striped dolphin in this study, the hepatic concentration of Hg exceeded the higher toxic thresholds (400 mg/kg w.w.) previously defined as evidence of liver damage in marine mammals. The Hg:Se molar ratio in the liver of Risso's dolphin was 0.670. The liver of adult bottlenose dolphins showed expected values (0.870), while the liver of young dolphins had a high ratio (0.750), non-specific for the age group. The Hg:Se molar ratio in the liver of striped dolphins was 0.390, which is lower than the literature values.
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•Hg and Se were determined in 186 specimens stranded in the Adriatic Sea.•64 individuals exceeded the lower critical level (Hg = 100 mg/kg) in liver.•The upper critical level in the liver (Hg = 400 mg/kg) exceeded 29 dolphins.•Bioaccumulation of Hg and Se was found in the liver of dolphins.
The bacterial species
is the most common causative agent of mastitis in cows in most countries with a dairy industry. The prevalence of infection caused by
ranges from 2% to more than 50%, and it ...causes 10-12% of all cases of clinical mastitis.
The objective was to analyze 237 strains of
isolated from the milk of cows with subclinical mastitis regarding the
,
and
genes and to perform
and multi-locus sequence typing (MLST).
Sequencing amplified gene sequences was conducted at Macrogen Europe. Ridom StaphType and BioNumerics software was used to analyze obtained sequences of
and seven housekeeping genes.
The
fragment was present in 204 (86.1%) of strains, while
and
gene were detected in 10 strains, and the
gene was not detected.
typing successfully analyzed 153 tested isolates (64.3%), confirming 53
types, four of which were new types. The most frequent
type was t2678 (14%). MLST typed 198 (83.5%) tested strains and defined 32 different allele profiles, of which three were new. The most frequent allele profile was ST133 (20.7%). Six groups (G) and 15 singletons were defined.
Taking the number of confirmed
types and sequence types (STs) into account, it can be concluded that the strains of
isolated from the milk of cows with subclinical mastitis form a heterogenous group. To check the possible zoonotic potential of isolates it would be necessary to test the persons and other livestock on the farms.
► Higher cadmium and mercury levels found in the southern than in the northern region. ► In both regions lead levels found were above the maximum residue levels. ► Similar mean copper levels found in ...both regions. ► Arsenic levels exceed the maximum residue levels in only 2–9% of samples.
A total of 157 raw milk samples were collected from tankers arriving at processing facilities from rural areas in northern and southern regions of Croatia during 2009 and 2010. Concentrations of As, Cd, Cu, Hg and Pb in the samples were analysed by graphite furnace-atomic absorption spectroscopy. Mean Pb concentrations in northern and southern regions were 58.7 and 36.2μgl−1, respectively, and both exceeded the maximum recommended level. Arsenic concentrations ranged from 1 to 283μgl−1 in the southern and to 1019μgl−1 in the northern regions. Mean Cd and Hg levels were: 1.76 and 1.59 in the northern and 3.4 and 7.1μgl−1 in the southern region. Significantly higher Cd and Hg levels were observed in the southern than in the northern region (p<0.001, both). Similar mean Cu levels were found in both regions: 931.9 in the north and 848.4μgl−1 in the south. The results indicate that particular attention should be paid to Pb residues. In future studies, a greater number of milk samples and grass samples from pastures from different regions of Croatia should be controlled to confirm the absence of possible toxicological risks.
Bovine mastitis causes changes in the milk and serum proteomes. Here changes in both proteomes caused by naturally occurring subclinical and clinical mastitis have been characterised and quantified. ...Milk and serum samples from healthy dairy cows (n = 10) were compared to those of cows with subclinical (n = 12) and clinical mastitis (n = 10) using tandem mass tag (TMT) proteomics. Proteins that significantly increased or decreased in milk (n = 237) or serum (n = 117) were quantified and classified by the type of change in subclinical and clinical mastitis. A group of the proteins (n = 38) showed changes in both milk and serum a number of which decreased in the serum but increased in milk, suggesting a particular role in host defence for maintaining and restoring homeostasis during the disease. Proteins affected by bovine mastitis included proteins in host defence and coagulation pathways. Investigation of the modified proteomes in milk and serum was assessed by assays for haptoglobin, serum amyloid A and α1 acid glycoprotein validating the results obtained by quantitative proteomics. Alteration of abundance patterns of milk and serum proteins, together with pathway analysis reveal multiple interactions related to proteins affected by mastitis. Data are available via ProteomeXchange with identifier PXD022595.
Mastitis is the most serious condition to affect dairy cows and leads to reduced animal welfare as well as having a negative economic effect for the dairy industry. Proteomics has previously identified changes in abundance of milk proteins during mastitis, but there have been few investigations addressing changes that may affect proteins in the blood during the infection. In this study, changes in the abundance of proteins of milk and serum, caused by naturally occurring mastitis have been characterised by proteomics using a quantitative approach and both subclinical and clinical cases of mastitis have been investigated. In both milk and serum, change in individual proteins was determined and classified into varying types of altering abundance, such as increasing in subclinical mastitis, but showing no further increase in clinical mastitis. Of special interest were the proteins that altered in abundance in both milk and serum which either showed similar trends - increasing or decreasing in both biological fluids or showed reciprocal change decreasing in serum but increasing in milk. As well as characterising proteins as potential markers of mastitis and the severity of the disease, these results provide insight into the pathophysiology of the host response to bovine mastitis.
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•Proteomes of milk and serum in mastitis have been quantified by TMT proteomics.•Changes in the abundance of many milk and serum proteins occur in mastitis.•Haptoglobin and serum amyloid A increase in milk and serum in mastitis.•β-2 microglobulin and β-casein decrease in milk and serum during mastitis.•α2-macroglobulin and apolipoprotein A2 increase in milk but decrease in serum.
The aim of the study was to determine effects of dietary clinoptilolite (CPL) supplementation on β-hydroxybutirate (BHB) serum levels and milk fat to protein ratio (FPR) during early lactation in ...Holstein-Friesian cows. Seventy cows of the Holstein-Friesian breed, aged from 3 to 5 years, kept in a farm nearby Đurđevac, Croatia, were used in the study. The cows were randomly assigned into two groups, either test, in-feed CPL treated; CPL (n = 35) or control, non-treated group; CON (n = 35). The CPL group received 50 g of natural modified CPL preparation in the ratio for dairy cows, twice a day, from third month of pregnancy. Blood and milk samples were collected from the cows after parturition on days 7, 12, 19, 26 and 33 of lactation. The average value of BHB was higher in the CON than in the CPL group (1.03 ± 0.78 vs. 0.82 ± 0.42 mmol/L), as well as average value of FPR (1.32 ± 0.20 vs. 1.24 ± 0.14), but without significant differences. The highest BHB serum levels were obtained on days 12 and 19 of lactation in the CON group and in the CPL group on day 12. The cows in CPL group had lower BHB levels and FPR ratio, mostly, in the optimal range or below, while cows from CON group had FPR higher than optimal on days 19, 26 and 33 after parturition. In the CON and CPL groups 17.5% and 7.9% cows, respectively suffered from subclinical ketosis. On days 7, 12 and 19 non-esterified fatty acids were significantly higher in the CON group than in the CPL group. The cows from the CON group were in severe and longer negative energy balance than the cows from the CPL group. In conclusion, the CPL had positive effects on BHB serum levels and FPR during early lactation in Holstein-Friesian cows.
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•Zeolite decreased BHB serum level during early lactation in dairy cows.•Zeolite had positive effect on milk fat to protein ratio during early lactation in cows.•Zeolite decreased severity and duration of negative energy balance in dairy cows.
Bacillus anthracis, the causative agent of anthrax disease, is a worldwide threat to livestock, wildlife and public health. It is also considered one of the most important pathogens of bioterrorism. ...Rapid and reliable diagnosis and administration of antimicrobials are essential for effective anthrax treatment. In this study, we determined the in vitro susceptibilities of 40 isolates of B. anthracis isolated in Croatia over the recent two decades to 18 antimicrobials. Whole-genome sequencing was performed, and bioinformatics tools were used to determine virulence factors and antimicrobial resistance genes. Core genome-based multilocus sequence typing was used for isolate comparison and phylogenetic analysis. All isolates were susceptible to all antimicrobials recommended for post-exposure prophylaxis or anthrax therapy. Susceptibility was found to all other tested antimicrobials that are an alternative for primary therapy. We found two beta-lactamase genes, but their expression is not sufficient to confer resistance. In all isolates used in this study, we found 21 virulence genes, 8 of which are responsible for toxin and capsule production. As far as phylogenetic analysis is concerned, the B. anthracis isolates from Croatia are categorised into two clades. The first is clade A, subclade Trans Eurasia, and the other is clade B, subclade B2.
The aim of this study was to investigate the influence of season, rainfall and air temperature on the reproductive efficiency in the Romanov breed of sheep in continental part of Croatia during five ...consecutive years (2012–2016). During this period, 5379 matings resulted in 5046 successful conceptions, i.e. lambings at eight medium-scale Romanov breed sheep farms. The conception rate was 93.81%, fecundity was 195% and average preweaning mortality until 90 days of age was 12.41%. The seasonal distribution of lambings was 47.64% for ewes that delivered in winter (
n
= 2422), 23.37% in spring (
n
= 1179), 18.82% in summer (
n
= 950) and 9.81% in autumn (
n
= 495). Sexual activity was lowest during spring and early summer when air temperatures were above average (very and extremely warm), and sexual activity peaked from August to September, especially during extremely wet and very wet seasons. Litter size was greater during winter than in other seasons (1.70 vs. 1.54) and was significantly different as compared to each of selected years of the study period. There was a statistically significant difference in the number of pregnant ewes between mating seasons. Most female Romanov lambs born during winter and early spring mated in late summer or autumn and delivered at the age of 1 year or earlier. The seasonal distribution of matings and lambing was not uniform throughout the seasons over five consecutive years. Thus, it can be assumed that air temperature and rainfall during different seasons could affect the reproductive efficiency in Romanov breed of sheep in continental part of Croatia.
•Concentrations of toxic and essential elements were determined in 11 fishes.•The most abundant elements measured were Fe and Zn followed by As.•Highest As, Cu, Fe, Mn, Ni and Zn levels were measured ...in sardine.•For all elements significant differences between fishes were found.•High As and Hg levels for some fishes suggest a strong public concern for consumers.
Concentrations of toxic (Al, As, Cd, Cr, Hg, Mn, Ni, Pb) and essential elements (Cu, Fe, Zn) were measured in 11 fish species purchased from supermarkets located in different Croatian cities. Mean element concentrations in fishes ranged: mg kg−1: Al 0.13–3.5, As 0.52–3.4, Cu 0.24–0.88, Fe 2.0–19, Mn 0.095–1.6, Zn 3.4–18; μg kg−1: Cd 0.61–123, Cr 5.0–41, Hg 17–130, Pb 2.0–59, Ni 5.5–51. The highest mean concentrations of elements were found in fishes: Al in cod; Cd in bluefin tuna; Cr in rainbow trout; Hg in European sea bass; Pb in canned sardine; As, Cu, Fe, Mn, Ni and Zn in sardine. Significant differences in the concentrations of all elements measured were found between fish species. Mean Cd levels of 123 μg kg−1 for bluefin tuna exceeded the European Commision limit of 100 μg kg−1. An estimation of the dietary intake of elements associated with the consumption of the studied fish species, and its comparison with the toxicological reference values is provided. The obtained results suggest a strong reason for public concern with regard to exposure to As and Hg for consumers who often consume certain types of fishes.
is present in the normal intestinal flora but some strains can cause intestinal and extraintestinal diseases, and research on its presence in food of animal origin is in the interests of public ...health. This study was designed to characterise
strains according to their origin, their carriage of virulence genes specific for certain pathogroups, and phylogenetic group affiliation.
The study was carried out on 100
strains isolated from food samples of various animal origin as well as pig and cattle carcass swabs. Isolation of the strains was performed using two methods. One method included colony count and the other an overnight enrichment of the samples. Isolation was followed by DNA extraction and detection of virulence genes and phylogenetic group with conventional and multiplex PCRs.
In this study, the most prevalent gene was
(20%) and strains which carried it were identified as enteroadherent
. Other pathogroups were represented in lower incidences. Phylogenetic group analysis revealed the prevalence of the A and B1 groups, with B1 mainly present in game and cattle strains, while the majority of pig and poultry strains were assigned to group A.
This study provides an overview of the presence of potentially pathogenic strains and
phylogenetic groups in Croatia, for which the data are limited. Further microbiological and molecular research is required to examine the epidemiological situation in the country.
Mastitis is one of the most frequent diseases of dairy cows throughout the world, therefore it causes the greatest economic losses in dairy cattle industry. These losses are reflected through: ...reduced milk production, increased costs of medication and the other animal health services, reduced fertility, early culling of animals and the value of discarded milk. Mastitis is also important from the aspects of public health, milk processing and animal welfare. In the pathogenesis of mastitis the key role plays the innate immune response which is the first line of defence against the pathogen invasion of the udder. The innate immune response generates an inflammatory reaction which is the elementary response of an organism to the tissue trauma induced by any physical, chemical or biological causative agent, but primarily it is the protective mechanism of a vital significance which includes increased phagocytic activity, secretion of antimicrobial substances, fibrosis as well as the alterations in tissue structure of affected organ or body cavity. The release of a number of inflammatory mediators as well as reactive oxygen species (ROS) is an important part of inflammatory response. In dairy cows, the metabolic challenge that occurred during the transition from dry period to early lactation may additionally increase the release of ROS which may contribute to development of oxidative stress and inflammatory response. Oxidative stress is defined as a shift in the balance from cellular oxidation-reduction reactions towards oxidation, i.e. to the state of excessive release of oxidants when their removal by antioxidants is impaired and even insufficient. During peripartum period antioxidantive status of dairy cows is seriously impaired and consequently both the oxidative stress and inflammatory response may present the predisposing factors to their higher susceptibility to intramammary infections (IMI) and mastitis. This association between oxidative stress and inflammation during IMI and mastitis indicates their role in the pathogenesis of mastitis. Thus, a better understanding of such a synergism could contribute to development of new approaches to prevention and therapy of IMI and mastitis.
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