Antimicrobial susceptibility of Pseudomonas aeruginosa isolates from dogs with otitis externa

Pseudomonas aeruginosa is a common cause of otitis externa in dogs, and treatment of these infections is becoming problematic because of the increasing number of multiresistant strains. The aim of the present study was to compare the in vitro activities of cefepime, ceftazidime, enrofloxacin, ciprofloxacin, gentamicin and ticarcillin/clavulanic acid against 104 strains of P aeruginosa isolated from dogs with otitis externa. Antimicrobial susceptibility and minimum inhibitory concentrations, in μg/ml, were evaluated by the E test (bioMérieux). The most active compound was ceftazidime, with 100 per cent efficiency. The majority of tested strains were susceptible to ticarcillin/clavulanic acid (89.4 per cent), followed by ciprofloxacin (88.5 per cent) and cefepime (60.6 per cent). The highest resistance was observed to enrofloxacin (51.9 per cent) and gentamicin (43.3 per cent). Large numbers of strains were intermediately susceptible to antibiotics registered for use in veterinary medicine in Croatia--enrofloxacin (47.1 per cent) and gentamicin (41.3 per cent).     

Proportion of circulating chicken heterophils and CXCLi2 expression in response to Salmonella enteritidis are affected by genetic line and immune modulating diet

Genetic line and diet affect chicken heterophil activity and gene expression, and the combination of these factors can enhance disease resistance. This study evaluated the effects of immune modulating diets on heterophil/lymphocyte (H/L) ratio and heterophil chemokine expression in distinct genetic lines. Fayoumi and Leghorn chickens were fed a basal diet or immune modulating diets enhanced with β-glucans, ascorbic acid, or corticosterone. H/L ratios and heterophil gene expression in response to in vitro stimulation with Salmonella enteritidis (SE) were evaluated on days 1, 3, 7, and 21 of diet treatment. The stress-mimicking corticosterone diet influenced H/L ratio in the Leghorn line, but not the Fayoumi line, suggesting resistance to stress-induced immunosuppression in the Fayoumi line. Leghorn line H/L ratios were increased on days 1 and 3 of corticosterone diet treatment, but not days 7 or 21. Expression of CXCLi2 by SE stimulated heterophils was higher in the Leghorn line, suggesting that Leghorns rely more heavily on inflammatory response than do Fayoumis. Corticosterone diet was associated with reduced CXCLi2 expression in heterophils from both lines. Dietary β-glucan or ascorbic acid did not affect H/L ratio or CXCLi2 expression, suggesting that benefits of these immunomodulators may not be evident in healthy birds.     

The presence of methicillin-resistant Staphylococcus aureus on large pig breeding farms in Croatia

Methicillin-resistant Staphylococcus aureus (MRSA) have emerged worldwide and have become resistant to a variety of antibiotics. MRSA colonisation in pigs was first reported from the Netherlands in 2005, where pigs were implicated as a source of human MRSA infections (Voss et al., 2005). This paper presents the first report on the presence of MRSA on large pig breeding farms in Croatia, together with the determination of the mecA gene, the results of spa typing and susceptibility to commonly used antimicrobials. Dust samples (7-11 per farm) were collected from eight large pig farms in Croatia. Of the total 68 swabs, the mecA gene was detected in 24 isolates growing on the MRSA agar. All isolates were resistant to oxacillin, tetracycline and streptomycin, and susceptible only to vancomycin, while 92% of the strains were susceptible to ciprofloxacin. Genotyping of the MRSA strains was performed by spa typing, and revealed t011 (n = 17), t034 (n = 5) and t1451 (n = 2). The results presented here predict that MRSA is present on a large number of pig farms in Croatia.     

Impact of controlled redox conditions on nickel in a serpentine soil

Purpose  

Serpentine soils exist in many regions around the world; they are naturally enriched with nickel (Ni). An adequate understanding of soil processes determining Ni solubility is a special need particularly since less research has been addressed to Ni behavior under dynamic and controlled redox conditions. Our aim was (1) to characterize the properties of a serpentine soil and (2) to determine the impact of predefined redox windows on the mobility and dynamics of Ni in a serpentine soil.     

Trace elements in soils and food chains of the Balkan region

Abstract

The present review summarizes the available data on the concentration of trace elements (TEs) in soils and their availability to plants with a view to reflect the quality and safety of food and fodder crops. Most soils in western Balkan countries are not contaminated. However, soils around industrial centers and historical mining sites do create concern for food and feed safety. Also high concentrations of TEs are related to their geochemical original. For example, ultrabasic rocks and serpentinites in western Serbia and western Bosnia are very rich in chromium, nickel, magnesium, iron (Fe), and cobalt, and cover an area of 5200 km². High TE concentrations caused by anthropogenic activities are also reported. In vineyard soils in Croatia, concentrations of cadmium, copper (Cu), and zinc (Zn) were much higher than their background concentrations. On the other hand, TE deficiency in plants is also prevalent in the regions. For example, Zn and Fe deficiencies in eastern parts of Croatia and northern parts of Serbia, Cu deficiency in pasture and sheep's blood at Nisici Plateau of Bosnia and Herzegovina, and selenium (Se) deficiency almost in the whole region have been observed. Therefore, information on TEs' behavior and soil factors affecting their mobility and availability is highly needed in order to separate the areas of contamination and then propose agrotechnical measures to protect the entry of TEs into the food chain. Research is also required to assess the influence of agronomic management on TE supply to plants and for achieving a better utilization of essential TEs. Concentrations of Se in wheat in Serbia are so low that if people were fed exclusively with wheat, their daily requirements for Se would not be met. There is also a need for full implementation of new food safety regulations in the Balkan countries in accordance with the legislations of the European Union.     

Die Veränderungen der Gehalte an essentiellen Aminosäuren während der Reifung des Weizenkorns

Changes in the contents of main aminoacids have been watched during the period of wheat ripening. The aminoacids have been determined by microbiological methods. The results obtained have been calculated according to the statistics used in British Pharmacopeia. Reliability range has been settled for each results separately. Determination fault amounts to ±4,6% on an average. The total aminoacids have been calculated to 16% nitrogen. According to analysis results the aminoacids can be classified in four groups, i.e.:

1. Aminoacids which share in total proteins remain constant during wheat ripening: Threonine, Valine, Isoleucine.
2. Aminoacids which share in total proteins decrease during wheat ripening: Lysine.
3. Aminoacids which share in total proteins increase during wheat ripening: Methionine, Arginine, Tryptophane.
4. Aminoacids whose contents show no regularity during the wheat ripening: Leucine, Histidine, Phenylalanine.

     

Distribution and Genotypic Characterization of Campylobacter jejuni Isolated from Poultry in Split and Dalmatia County,Croatia

Consumption of poultry contaminated with Campylobacter jejuni has been recognized worldwide as the leading cause of campylobacteriosis. Therefore, the aim of our study was to investigate the prevalence and genotype diversity of Campylobacter jejuni in poultry meat intended for consumption in Split and Dalmatia County, which is the second biggest County in Croatia. Furthermore, we also wanted to discover possibly stable clones of C. jejuni appearing in different samples and periods of time, which would indicate their ability to persist in or adapt to poultry. In the period from March 2008 until June 2010, 834 samples of poultry from various sources were examined using a surface swab technique. Isolation of C. jejuni was performed by Preston broth and Karmali agar. Identification of the isolates was carried out using biochemical tests. C. jejuni was found in 84 of 574 chicken samples (14.6%) and in nine of 260 samples of turkey (3.5%). Pulse‐field gel electrophoresis (PFGE) was used to analyse 61 obtained isolates using SmaI and KpnI. Of 22 different macrorestriction profiles (MRP) that were found, five were detected in poultry from both different locations and periods of time. Samples from 11 locations were found to be contaminated with more than two different genotypes of C. jejuni. Interestingly, the same MRP were found both in poultry declared to be of domestic origin and in the poultry imported from abroad. The prevalence of C. jejuni in poultry samples was in accordance with previously reported results. Genotypic analysis indicated that the population of C. jejuni in Split and Dalmatia County was diverse and that multiple strains of C. jejuni could be found in the same poultry samples. Furthermore, the same genotypes were identified from the samples obtained from different locations and periods of time, which could support the theory of a global existence of certain MRP that are able to persist in or adapt to poultry.     

Concepts and Direction of Induced Systemic Resistance in Plants and its Application

Resistance to plant disease is often specific and metabolites and receptors contributing to this specificity may have specific structures. However, simple, structurally-unrelated compounds induce systemic resistance in unrelated plants to diverse pathogens including fungi, bacteria and viruses. Both resistance and induced systemic resistance (ISR) are associated with the rapid accumulation of the same structurally unrelated putative defense compounds that have diverse functions. It has been suggested that cultivar (race)-specific resistance is initiated by the specific interaction of a pathogen product (or pathogen induced product) and a plant receptor. However, restricted infection by pathogens can result in ISR and many different compounds can cause ISR. It is thus evident that there are both specific and non-specific routes to the master switch for ISR and there may be more than one master switch. Are reactive oxygen species and free radicals regulating the master switch(es) via both routes? It is also evident there are many switches, other than the master switch. Adding to the complexity of resistance and ISR are the observations that different compounds and pathways may mediate different biochemical resistances. Activation of one of the pathways may antagonize or enhance the activation or effectiveness of another. The review will address these complexities and questions and propose directions of research which require high priority. Factors which encourage and suppress the application of ISR in agriculture will also be addressed.     

The impact of the chromium supplementation on insulin signalling pathway in different tissues and milk yield in dairy cows

Thirty days before expected time of parturition, 20 Holstein cows were divided into ?Cr and +Cr groups. From day 25 before parturition (BP ) up to day 30 after parturition (AP ), +Cr cows received 10 mg of Cr (chromium‐enriched yeast) daily. Muscle and adipose tissue samples were taken at days ?30, ?10, +7 and +10 related to parturition, when body condition score (BCS ) was also determined. Hepatic tissue samples were taken at days ?10 and +7. Tissue samples were used for determination of the insulin signalling pathway protein expressions. Intravenous glucose tolerance test (IVGTT ) was performed at days ?28, ?7, +10 and +30. Milk yield was recorded during first 14 weeks AP . Milk composition was obtained at days 7 and 28 AP . At day 10 BP , protein content of β ‐subunit of insulin receptor (IR β ) was significantly higher (p ? 0.05) in muscle, and phosphorylation of insulin receptor substrate 1 at serine 307 (pIRS ‐1 Ser³⁰⁷) was significantly lower (p ? 0.05) in hepatic tissue of +Cr group. After parturition, pIRS ‐1 Ser³⁰⁷ was significantly lower in muscle tissue at days 7 and 28 (p ? 0.05 and p ? 0.001, respectively), while phosphorylation of Akt at serine 473 (pA kt Ser⁴⁷³) was significantly higher (p ? 0.01) in hepatic tissue at day 7 AP in +Cr group. Chromium had opposite effect on insulin kinetics during IVGTT s obtained BP and AP . Insulin secretion was significantly reduced at day 7 BP and significantly enhanced at day 10 AP , when NEFA concentration was also significantly increased. Milk yield and ECM value were depressed in +Cr group. DMI and BCS were significantly enhanced in +Cr group at day 7 BP . In conclusion, chromium modulates insulin signalling pathway in dairy cows, but targeted signalling molecules are different in antepartal then post‐partal period, probably due to duration of exposure to chromium and different energy status between those periods.