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Colibacillosis, caused by avian pathogenic Escherichia coli (APEC), is one of the most prevalent and economically damaging bacterial diseases affecting poultry globally. Managing colibacillosis is difficult and frequently ineffective because APEC strains have developed widespread resistance to antibiotics, and the strict regulations and public concerns towards using antimicrobial agents in poultry further complicate the situation. This study aimed to evaluate the antibacterial properties of hydrolysable (sweet chestnut extract) and condensed (quebracho extract) tannins on Escherichia coli (E. coli) isolates from poultry, exploring their potential as antibiotic alternatives in managing colibacillosis. E. coli was isolated from the internal organs of deceased poultry across 18 farms, including layers, broilers, and broiler breeders. Each isolate was assessed for the presence of APEC strain predictors (virulence genes iutA, hlyF, iss, iroN, and ompT), antimicrobial resistance to 14 antibiotics using the disc diffusion method, and the presence of resistance genes for specific antibiotics (ampicillin, gentamicin, tetracycline, and quinolones). Out of 43 isolates, 27 (62.8%) were classified as APEC, 30 (69.8%) showed resistance to three or more antibiotic classes, and 32 (74.4%) carried at least one AMR gene. The minimum inhibitory concentrations (MICs) for the hydrolysable tannins from sweet chestnut extract (Castanea sativa Mill.) (SwCh) ranged from 0.5 to 3 mg/mL, while for the condensed tannins from quebracho extract (Schinopsis lorentzii) (Que), the MICs ranged from 1.5 to 4.5 mg/mL. The results indicate that both hydrolysable and condensed tannins possess significant in vitro antimicrobial activity against APEC, offering a potentially valuable alternative for controlling colibacillosis in the poultry industry.

Eight lovebirds of both sexes and different age were admitted showing alterations in behaviour and apathy. During the initial examination delamination of the beak was noted in all birds and discrete areas of alopecia in three of eight birds. Based on clinical experience, molecular diagnostic on PBFD, sequencing of obtained amplicons, and histopathological examination were performed. All birds tested positive on the presence of PBFD virus, despite the fact they did not exhibit expected clinical signs for PBFD. Sequencing results showed 100% match with sequences previously isolated from parrots with PBFD exhibiting classical PBFD manifestation. Histopathological examination showed similar findings as in previously described cases of PBFD in parrots. Other studies on psittacine birds correlate clinical manifestations and nucleotide variations with geographic localization. Our results indicate that the clinical manifestation of the disease is more dependent on bird species than on the genetic variation of the virus or the geographical distribution.

We present a case of Ascaridia galli infection in laying hens on a farm in central Serbia. During the rearing period on litter, ascaridosis was diagnosed at 15 weeks of age by routine parasitological fecal examination. Pullets were treated with flubendazole for one week, and two weeks later the hens were moved to battery cages. The production results were within technological standards until the 23rd week and the medical health status was without any clinical symptoms. After that period weight loss began, the egg production dropped to 70% and eggs were of poor quality. Subsequently, severe feather pecking and an increase of mortality were reported. The postmortal examination showed severe anemia and several gross lesions in the liver, intestines, lungs, and kidneys. Different sizes of A. galli were found in the lumen of the duodenum and jejunum. Gross changes of the intestinal mucosa were present, such as a thickened intestinal wall with hemorrhagic spots, inflammation and necrotic patches. Histopathological examination showed marked changes in the intestines, liver and kidneys. All visible live parasites were collected and stored in Earle’s balanced salts, and females were used for in vitro susceptibility testing. Median lethal concentration (LC50) of piperazine, levamisole and carvacrol for A. galli was 119.7μM, 2.71μM and 3.26μM, were applied, respectively. Based on our results, it is likely that reinfection occurred after completed dehelmintization. In relation to the new circumstances and the regulation for laying hen welfare the deworming protocol should be changed in order to ensure successful dehelmintization. In order to prevent reinfection the treatment must be done at the end of the rearing period and thus be maximally effective.

Determining the sex in birds is very difficult, primarily because over 50% of species is monomorphic (no morphological differences between the sexes). Before the application of molecular genetic methods, there were used numerous methods all of which were un­reliable. Because of the importance of the analyses, they have to be reliable, economical, safe and prompt. Highly conserved CHD gene is defined in 1995. on W chromosome in birds, while on Z chromosome it was defined two years later. The difference in the length of the intronic sequences of CHD gene of Z and W chromosomes enables the distinguishing of the sexes after amplification of specific fragments by the application of specific primers. Molecular genetic methods have the supremacy over all the other methods because, ex­cept for being safe (both for birds and people), they provide reliable results, and also can be applied in all bird species.

Health risks associated with the consumption of products contaminated with mycotoxins are worldwide recognized and depend on the extent to which they are consumed in diversified diet. To some extent, the presence of small amount of mycotoxins in cereals and related food products is unavoidable; this requires risk assessments which are to be carried out by regulatory bodies in several countries to help establish regulatory guidelines for the protection of public health. By assessing the levels at which these substances in food may pose a potential risk to human health, it is possible to devise appropriate risk management strategies. However, several important factors have to be taken into account in making a rational risk management decision, such as adequate toxicological data and information concerning the extent of exposure, availability of technically sound analytical procedures (including sampling), socioeconomic factors, food intake patterns and levels of mycotoxins in food commodities which may vary considerably between countries.

Considering that more than 50% of bird species are monomorphic, the identification of gender based on phenotypic characteristics is extremely difficult. The aim of this study is sex determination in species inhabiting the Republic of Serbia, all under the state protection and declared by IUCN as endangered. DNA was isolated from feathers. Sex determination was based on sex-specific CHD gene amplified by 2550F/2718R primer set. Sexing gave good results in all 91 samples from 20 species including 6 species where molecular sexing has not previously been successful. [Projekat Ministarstva nauke Republike Srbije, br. 46002]

This investigation was conducted in order to investigate the efficacy of the detoxifying agent Mycofix® Plus (MP) in the prevention and/or alleviation in vivo adverse effects of T-2 toxin in broilers. In addition, the adsorbing potential of MP was estimated in vitro. Mean degradation levels of T-2 toxin with MP in vitro, as measured by HPTLC, varied from 26.06 to 31.02 % and the adsorption ability was elevated in acidic environment (pH 3). In vivo trial was performed on 160 one day old "Ross" broiler chicks and lasted for 21 days. Birds were divided into 4 equal groups as follows: Group 1 - negative control; Group 2 - positive control - 2 ppm T-2 toxin; Group 3 - 2 ppm T-2 toxin+2 kg/t MP; Group 4 - 2 kg/t MP. Broilers fed the diet containing 2 mg/kg of T-2 toxin without MP developed typical T-2 toxicosis. Birds that were fed the diet containing both T-2 and MP had better performances and no oral ulcerations as the dominant sign of T-2 toxicosis were observed. Histopathological examination of tissues originating from birds fed the diet containing T-2 toxin revealed degenerative changes in the oral and small intestine mucosa, necroses of enterocytes and hepatocytes, as well as depletion of lymphocytes in the bursa Fabricii. Immunohistochemical examination also revealed negative effects of T-2 toxin on cells proliferation in intestineal and bile duct mucosa, as well as on lymphocytes from bursa Fabricii. The macroscopic and microscopic structure of the liver, intestine and bursa Fabricii of broilers fed a diet containing T-2 toxin and MP was mostly preserved. Cutaneous basophile hypersensitivity reaction was weaker in broilers fed mixtures containing 2 mg/kg T-2 toxin.

Five strains of Newcastle disease virus (NDV) were obtained from poultry in Vojvodina, Serbia during the outbreaks in 2006 and 2007. These isolates were confirmed and genotypically characterized by reverse transcription polymerase chain reaction (RT-PCR) with primer specific to the viral fusion (F) protein (572bp), and by sequencing of partial F gene for phylogenetic analysis. Phylogenetic analysis showed that all five isolated strains of Newcastle disease virus belong to genotype VII. At the same time, all five isolates were clustered in NDV subtype VIId. The examined NDV isolates express high similarity to each other (99.7-100%) and group together with the strains of Newcastle disease virus isolated previously from wild birds in Serbia during the same 2006 - 2007 outbreak. The analysis of the isolates F gene cleavage sites has shown that all five isolated strains of Newcastle disease virus had a cleavage site motif 112R-R-Q-K-R-F-117 characteristic for highly virulent, velogenic strains. [Projekat Ministarstva nauke Republike Srbije, br. 31008 i br. 31084]

Background/Aim. Zeolites are the hydratised alumosilicates of alcali and earthalcali cations, which have a long three-dimensional crystal structure. Preparations on the basis of zeolites are used for adsorption of organic and nonorganic toxic substances and they, also, find more and more use in veterinary and human medicine and pharmacy. The aim of this study was to evaluate the possibilities of zeolite to adsorb vitamins B1, B2 and B6 in acid and neutral solutions, as well as the characteristics of the process (saturability, reversibility and competitivness). Methods. The specific and sensitive HPLC method with fluorescent detector was used for determination of vitamins B1, B2 and B6. Analyte separation and detection were carried out by applying the reverse-phase method on column C18. An in vitro experiment was done by testing the influence of pH value (2 and 7), concentration of vitamin solution (1, 2 and 5 mg/L), the lenght of contact with zeolite (10-180 min) and cation competitiveness on the exchange capacity, which is achieved by media and zeolite contact, as well as a possible vitamins desorption through changing pH value of the solution at 37°C. Jon competitiveness was examined by adding commercial feed mixture (grower) with a defined content of the examined vitamines in zeolite solutions the pH = 2 and pH = 7. Results. Vitamins B1, B2 and B6 were stable in both pH=2 and pH = 7 solutions at 37°C, in the defined time intervals. In acid solution concentrations of vitamins significantly declined in the first 10 min, with no significant decline in further 30 min for all the three concentrations testch. In neutral solution, after the addition of 1% zeolite, decrease in vitamins concentrations was slightly lower than in acid solution, but also significant in the first 10 min of the contact with zeolite. It was found that zeolite, which adsorbed vitamins in acid solution, transferred in the neutral one released a significant quantity of adsorbed vitamins after 30 min of extraction on 37°C. Vitamins B1, B2 and B6 from a commercial feed mixture in pH = 2 solution, at 37°C, were significantly adsorbed on zeolite after 30 min of the contact (21.87%, 20.15% and 4.53%, respectively), while in neutral solution there was no statistically significant adsorption. Conclusion. Zeolite significantly adsorbs vitamins B1, B2 and B6 in acid and neutral solutions at 37°C, already in the first 10 min of the contact. Adsorption was irreversible, but partly reversible after changing pH from acid to neutral. This is a significant ions competition for adsorption on zeolite in neutral solution, so no statistically significant vitamins B1, B2 and B6 adsorption occurs, while in acid solution competition is less, thus zeolite significanthy adsorbs these vitamins, although in less degree than in conditions with no concurrent ions.

This paper deals with the biosynthetic capacity for ochratoxin A (OTA) production by Aspergillus ochraceus E'G isolate derived from A. ochraceus CBS 108.08 strain, during 2007. Preliminary analysis of fungal potential for the production of OTA were performed according to the modified method of Filtenborg et al. (1983). Toxin production was tested in the following liquid media: (i) glucose-peptone-yeast extract broth (GPY - pH 5.6), (ii) potato-dextrose broth (PDB - pH 6.9), (iii) yeast extract-sucrose broth (YES - pH 6.5), and (iv) YES broth supplemented with 0.23 mg/l ZnSO4 x 5 H2O (YESZn - pH 6.5) after stationary and submerged cultivation. Dynamics of OTA biosynthesis was tested after the cultivation of A. ochraceus E'G on natural solid substrates, such as wet sterilized rice, corn and wheat grain. Cultivations were performed during different time periods (ranging from four days to few weeks) at different temperatures (ranging from 21°C to 30°C). The presence of OTA was determined as follows: (i) in liquid media according to the method of Balzer et al. (1978) modified by Bočarov-Stančić et al. (2003), and (ii) in the solid substrates according to the Serbian official methods for sampling and analyzing of fodder (Official Gazette of SFRY, No. 15/87). After the cultivation of A. ochraceus E'G isolate in liquid media, the highest yield of OTA (6.4 mg/l) was obtained after submerged cultivation in PDB (4 days, 128 rpm, 21-23°C). In the case of cultivation on solid substrates, the highest amount of OTA (800.0 mg/kg of dry matter) was recorded after several week long cultivation on wheat grain at 30±1°C.

All poultry is sensitive to mycotoxins. This partly depends on the type, age and production categories of poultry, their living conditions and nutritive status and partly on the type, quantity and duration of mycotoxin ingestion. The presence of mycotoxins results in significant health disorders and a decrease in production performances. This leads to considerable economic loss for the poultry industry - either direct losses, i.e. death of the poultry or the indirect ones, i.e. the decrease in body mass, number and quality of eggs, greater food conversion, and immunosuppression. Immunosuppression results in increased sensitivity to infective agents and a bad vaccinal response. Morevover, mycotoxin residues in poultry meat, eggs and products derived from them pose a threat to human health. In order to prevent and reduce the negative implications of mycotoxins in the poultry production, it is necessary to create both global and national strategies for combatting mycotoxins, advance diagnostic techniques and procedures, intensify the control of food quality, introduce new limits on the maximum amount of mycotoxins allowed in food and poultry feed used for certain species and categories of animals, and synchronise it with the European standards.

In this study female Wistar rats were treated with T-2 toxin (1 LD50 0.23 mg/kg sc) and sacrificed on days 1, 3, 5, 7, 14, 21, 28 and 60 after the treatment. Control groups of rats were treated by saline (1 ml/kg 0.9% NaCl). At each time-schedule, control groups of animals were sacrificed, too. Pathohistological alterations of the heart were evaluated in whole visual fields stained by haematoxylin and eosin (HE), periodic acid- -Schiff's (PAS), Masson-Trichrom's (MT) and Giemsa (GIM) methods. The changes observed were scored by using semiquantitative grading scale. The heart alterations detected in T-2 toxin-treated animals ranged from focal parenchymal or hyaline degeneration (HE = 2.5 - 4.0; p < 0.05 vs. control) to diffuse necrosis of muscle cells (HE = 5.0; p < 0.05 vs. control and 1st day after T-2 treatment). The myofibrils were slightly PAS-positive during the first week of the study (PAS = 2.0 - 3.2; p < 0.05 vs. control and 1st day after T-2 treatment), while a diffuse distribution of glycogen granules in endo- and perimisium were observed from day 21 to 60 in the whole heart' tissue (PAS = 4.0; p < 0.05 vs. control and 1st day after T-2 treatment). Massive hemorrhagic foci associated with diffuse accumulation and degranulation of MCs were the most intensive from day 28 to 60 of the study (MT = 5.0; p < 0.05 vs. control and 1st day after T-2 treatment). During the whole study period, irregular distribution of glycogen granules, intensity and total number of haemorrhages were in correlation with the degree of heart structural lesions, which showed the highest coefficient of correlation (r = 0.8750; p < 0.001). Our results indicate that basic histohemical methods can be a useful tool for evaluation of T-2 toxin-induced cardiac damage, which is probably a result of complex inflammatory mechanisms, eventually leading to vascular lesions and myocardial necrosis, as well as for some potential cardioprotectors in the future.

A 21-day-long experiment was performed on 160 one-day-old 'Ross' broiler chicks. This research was done with the aim of investigating pathomorphological changes in broilers exposed to a relatively small amount of T-2 toxin (2 ppm) and the possibility of prevention and/or alleviating adverse effects of T-2 toxin using various feed additives. Pathohistological examination showed negative consequences of T-2 toxin in all examined organs as degenerative changes developed in small intestine mucosa, enterocites and hepatocites necroses, as well as lymphocites depletion in bursa of Fabricius. Disparately from inorganic (Minazel-plus, Mz) and organic (Mycosorb, Ms) adsorbents, which did not provoke protective effects, in liver, small intestine and bursa of Fabricius of broilers who were given feed with T-2 toxin and mixed adsorbent (Mycofix-plus, Mf), mostly preserved structure of these organs could be noted.

In the trial, in vitro HPTLC - High Performance Thin Layer Chomatography was used to determine the amount of 'free', i.e. unbound or non-decomposed T-2 toxin. Mean adsorption or degradation levels of T-2 toxin in examined feed aditives, in in vitro conditions, ranged from 26.06 to 34.84% and did not significantly differ among used adsorbents: inorganic (Minazel plus - Mz), organic (Mycosorb - Ms) and mixed (Micofyx - Mf). All these additives showed better adsorption ability in the acidic environment (pH3).

With the increased demand of consumers for safe poultry products, efficient control of pathogenic microorganisms that cause diseases in humans is becoming the chief challenge in contemporary poultry production. Poultry meat, eggs and related products present the main source of salmonellosis in humans that occurs as a result of the consumption of contaminated food. Any serotype of Salmonella spp. that is not strictly linked to the host is capable of causing gastrointestinal disorders of various degrees in humans. However, according to the World Health Organization (WHO), Salmonella enterica serotype enteritidis has been the leading cause of salmonellosis in humans over the past 10 years. One of the available prophylactic measures is resorting to the vaccination of poultry against salmonellosis. Several vaccines against poultry salmonellosis, produced by different manufacturers, have been registered in Serbia. In order for these vaccines to become widely used in our country, it is necessary that the factors in primary poultry production are aquainted with the mechanisms of action of these vaccines, the effects achieved by their implementation, the economic feasibility, and the possibilities for monitoring in keeping with the valid legal regulations. Certainly, vaccination should not be taken as the only method in the prophylaxis of salmonellosis, but as one of the very important methods in a series of biosafety and other measures that should be applied on poultry farms for the successful curbing of salmonellosis infections.

T-2 mycotoxin, secondary metabolite of Fusarium fungi, is one of the most potent cytotoxic representatives of trichothecene mycotoxin type A. After ingestion, T-2 toxin affects actively dividing cells and irreversible post-mitotic cells. In our experiments, the best protective effects were produced by dexametasone (PI = 3.37) and different methylprednisolone formulations (PI = 2.43-2.64). Significant protective efficacy was shown by nimesulide (PI = 1.44) and N-acethyilcistein (PI = 1.29), but their values were higher in a combination with methylprednisolone (PI = 2.16-2.34). Radioprotector amifostine (WR-2721) expressed good protective effects (PI = 1.26) or/and different absorbent formulations, such as: activated charcoal (PI = 1.13) and various Min-a-zel® powder compounds, which are a well known zeolite clinoptilolite absorbents. Among the five zeolite regimens investigated, only Min-a-zel Plus® showed a significant protective effect (PI = 1.77). In summary, the steroidal anti-inflammatory drugs could be recommended as a regimen of choice for treatment of acute T-2 toxicosis while nonsteroidal anti-inflammatory compounds, different absorbent formulations and their combinations with antioxidants or radioprotectors could be important for the treatment of subacute and chronic T-2 toxin poisonings.

Type A trichothecenes, T-2 toxin and diacetoxyscirpenol - DAS, belong to one of the most toxic groups of fusariotoxins. Although larger quantities of them can be found more often in cooler parts of Europe, regarding their metabolic characteristics and the types of illnesses they provoke, it is obvious that even smaller quantities of these toxins can cause serious health disturbances of humans and animals in climatic conditions of Serbia. Having in mind the importance of these substances, the aim of this study was to carry out the optimization of laboratory conditions under which screening of Fusarium spp. isolates from Serbia, regarding T-2 toxin and DAS production, should be done. Four cultures of Fusarium sporotrichioides originating from different regions throughout the world, were under present investigation: ITM-391 (Italy), KF-38/1 (Poland), M-1-1 (Japan) and R-2301 (Germany). According to the previous literature data, all of these isolates were T-2 toxin producers, and some of them were also DAS producers. The influence of medium composition (different C and N atoms sources microelements etc), as well as aeration (in liquid media), on biosynthesis process of these mycotoxins, in vitro conditions was investigated. In the case of most Fusarium sporotrichioides isolates, highest yields of T-2 toxin and DAS were achieved under the conditions of more intense aeration, and with the use of glucose (5 or 20%) as a C atom source. Fermentation in semi-synthetic liquid medium, using a rotary shaker, was more suitable for screening the toxicity of the fungal isolates in pure culture because of shorter period of incubation, more simpler sample preparation, obtaining less interfering materials in crude toxin extracts, and possibility for more precise definition of factors influencing the yield of trichothecenes.