African Swine Fever Outbreak in an Enclosed Wild Boar Hunting Ground in Serbia

African swine fever (ASF) has been detected in many European countries since its introduction in Georgia in 2007. Serbia suffered its first case of ASF in the domestic pig population in 2019. At the beginning of 2020, ASF was detected in wild boars in open hunting grounds in the southeastern region of the country in districts along the country's borders with Romania and Bulgaria. Since then, all ASF outbreaks in wild boar were clustered in the population located in the same bordering areas. Despite the newly implemented biosecurity protocols for hunters in 2019, ASF was detected for the first time in June 2021 in the wild boar population located in an enclosed hunting ground in the northeast region of the country. In this study, we reported the first ASF outbreak in a wild boar population located in an enclosed hunting ground in close proximity to the Serbian-Romanian border. The epizootiological data on the field investigation of the ASF outbreak, with descriptions of the clinical signs and gross pathological lesions detected, including the total number as well as the estimated age, sex, and postmortem interval, were analyzed. Clinical signs were detected only in nine diseased wild boars, while in total, 149 carcasses were found in the open and enclosed part of the hunting ground. In addition, 99 carcasses from which samples (parts of spleen or long bones) were collected for molecular diagnostics (RT-PCR) were confirmed as ASF-positive. The results of the epidemiological investigations indicate the central role of wild boar movements as well as the constant risk of human-related activities in the countries bordering area.

Highly Pathogenic Avian Influenza H5N8 Outbreak in Backyard Chickens in Serbia

In winter 2016/2017, the highly pathogenic avian influenza virus H5N8 was detected in backyard poultry in Serbia for the first time. The second HPAI outbreak case in backyard poultry was reported in 2022, caused by subtype H5N1. This is the first study that documents the laboratory identification and pathology associated with highly pathogenic avian influenza in poultry in Serbia during the first and second introduction waves. In both cases, the diagnosis was based on real-time reverse transcriptase PCR. The most common observed lesions included subepicardial hemorrhages, congestion and hemorrhages in the lungs, and petechial hemorrhages in coelomic and epicardial adipose tissue. Histologically, the observed lesions were mostly nonpurulent encephalitis accompanied by encephalomalacia, multifocal necrosis in the spleen, pancreas, and kidneys, pulmonary congestion, and myocardial and pulmonary hemorrhages. In H5N8-infected chickens, immunohistochemical examination revealed strong positive IHC staining in the brain and lungs. Following these outbreaks, strict control measures were implemented on farms and backyard holdings to prevent the occurrence and spread of the disease. Extensive surveillance of birds for avian influenza virus did not detect any additional cases in poultry. These outbreaks highlight the importance of a rapid detection and response system in order to quickly suppress outbreaks.

AFRICAN SWINE FEVER: A BIOSECURITY CHALLENGE FOR DOMESTIC PIG PRODUCTION IN SERBIA

African swine fever (ASF) is currently the most important challenge for domestic pig production worldwide. The virus reached Eurasia in 2007, and is today affecting more than half of European Union member countries. Among Western Balkan countries, Serbia suffered the first case of ASF in a backyard holding in 2019. Since then, numerous outbreaks in domestic pigs and wild boar have been reported throughout the country despite the efforts of the veterinary authorities to control the disease. The lack of an effective vaccine is one of the main constraints, and the only currently available option to prevent further ASF infections is the application of strict biosecurity measures. Regarding biosecurity, backyard pig producers and smallholding farmers in Serbia have substantial gaps in the knowledge and fail to comply with safe production behaviour that favours the spread of ASF virus. In the currently prevailing smallholder and backyards farming systems, farm biosecurity is largely non-existent. The aim of this review was to identify specific ASF-risks factors in the current pig production system and gaps in biosecurity measures related to the human activities recognised as social and cultural identity in Serbia. Moreover, the main risk factors for ASF spreading and transmission at the domestic/wild boar interface, biosecurity practices in different production systems, and possible future control measures and awareness campaigns are discussed.

IN VITRO STUDY OF THE EFFICACY OF MYCOTOXINS DEGRADATION BY FEED ENZYMES

Providing healthy and safe food in terms of mycotoxicological safety is an imperative for not only good and sustainable livestock production, but also for the population that consumes food of both plant and animal origin. Climate change in the temperate regions of southern Europe has led to frequent occurrence of aflatoxins, deoxynivalenol and zearalenone in cereals. In order to reduce harmful effects of these toxins on animal health as well as to avoid large economic losses, various feed additives are increasingly being used. All of them must first of all be safe, and then have certain efficiency in the fight against mycotoxins. Although in vivo experiments are mandatory to assess the efficacy, in vitro test offers the advantage of rapid screening of the efficacy of a large number of food additives. In this paper, the efficiency of two commercial products belonging to the enzyme group for animal nutrition was investigated for degradation of aflatoxin B1, zearalenone and deoxynivalenol using in vitro experiments. For this purpose, two different methodologies were used according to the recommendation of the enzyme manufacturer. The percentage of mycotoxin degradation was recorded by high pressure liquid chromatography and ELISA methods. One of the tested enzymes showed a very high efficiency in zearalenone degradation being as much as 96%. Both tested enzyme samples showed similar percentage of aflatoxin B1 degradation (about 35%). Deoxynivalenol was not significantly degradable under the applied test conditions.

MAIN RISK FACTORS OF AMERICAN FOULBROOD SPREADING IN HONEY BEES IN SERBIA

American foulbrood (AFB) is one of the most important contagious honey bee diseases. In Serbia, it is mandatory to report AFB, and this disease is registered in our country every year. Starting from 2018, active surveillance of the presence of the AFB has been conducted throughout the country. The paper analyzes the data on the occurrence of AFB during the period between 2019 and 2021 from official disease reports in the National Animal Disease Notification System "VetUp". The results of this research indicate that AFB appears every year in the Republic of Serbia, despite the measures that are being applied. The results indicate that in 36 settlements in the country, this disease has reoccurred in the same localities in the observed period. Namely, in 17 localities AFB occurred consecutively in the 2019-2020 period , while in 21 localities the disease was re-registered consecutively in the period between 2020 and 2021 (until 6.11.2021), and it reoccurred in 2021 in 9 localities, compared to the registered cases of AFB in 2019. It was found that the disease has consecutively been reoccurring in 5 location between 2019 and 2021 in the same locations. The fact that the disease has been occurring for several years in the same places speaks in favor of the fact that the control measures applied in the control of this disease are not effective enough. Continuing education of beekeepers, veterinarians and veterinary inspection in the field of diagnosis and effective decontamination and neutralization of all potencional sources of AFB reinfections, revision of current legislation, as well as raising awareness of the importance of early diagnosis of as many cases of this disease as possible are the key factors in successful AFB control.

THE MOST COMMON CAUSES OF HONEYBEE POISONING

 This paper will discuss the most common causes of poisoning of honey bees and other pollinating insects that occur in the Republic of Serbia and the world as well. Some potential ways of pollinator exposure to different poisons and their intake will be described. The paper will also deal with the methods of testing and assessing toxicity of newly synthesized chemical substances and new formulations, classification of potential toxic substances according to their chemical characteristics and mechanism of action on the insects, symptoms of honeybee poisoning and risk assessment for the uses of pesticides. In the end, the paper will look into the methods of responsible use of pesticides and their toxicity in order to avoid bee poisoning.  

CHARACTERIZATION OF SERBIAN SUNFLOWER HONEYS BY THEIR PHYSICOCHEMICAL CHARACTERISTICS

Abstract: Five physicochemical parameters (water content, electrical conductivity, total acidity (pH), ash mass fraction and concentration of free acids) were analyzed in 15 sunflower honeys collected from several localities in Vojvodina, Republic of Serbia. The mean values of analyzed honeys were: water content 16.87%; concentration of free acids 27.43 mEq/kg; electrical conductivity 0.34 mS/cm; pH 3.64. The selected physicochemical characteristics of all honey samples from Serbia analyzed in this research can be considered to be within the parameters expected for sunflower honey in general. The values for ash mass fraction, electrical conductivity and concentration of free acids in all sunflower honey samples showed similar trends. High correlation was established between electrical conductivity and ash mass fraction. Statistically significant difference at p≤0.05 (p=0.017) was established only for average values of free acids concentration between honey samples originating from the localities Kanjiža and Čelarevo. All of the analyzed honeys were found to meet national and European legislation for all investigated parameters. Therefore, further research on physicochemical properties of sunflower honey is required to confirm the quality and authenticity of this product and for better understanding the benefits of this honey.

Characterization of Serbian sunflower honeys by their physicochemical characteristics

Five physicochemical parameters (water content, electrical conductivity, total acidity (pH), ash mass fraction and concentration of free acids) were analyzed in 15 sunflower honeys collected from several localities in Vojvodina, Serbia. The mean values of analyzed honeys were: water content 16.87%; concentration of free acids 27.43 mEq/kg; electrical conductivity 0.34 mS/cm; pH 3.64 and ash mass fraction 0.13%. The selected physicochemical characteristics of all honey samples from Serbia analyzed in this research can be considered to be within the parameters expected for sunflower honey in general. The values for ash mass fraction, electrical conductivity and concentration of free acids in all sunflower honey samples showed similar trends. High correlation was established between electrical conductivity and ash mass fraction. Statistically significant difference (p≤0.05) was established only for average values of free acids concentration between honey samples originating from the localities Kanjiža and Čelarevo. All of the analyzed honey samples were found to meet national and European legislation for investigated parameters

CLASSICAL SWINE FEVER VIRUS DETECTION IN FETAL SWINE TISSUES BY IMMUNOHISTOCHEMISTRY

The classical swine fever virus has the ability to cross the placental barrier, resulting in the infection of fetuses, which may consequently lead to persistent infection in piglets. The aim of this study was to report the lesions in fetuses naturally infected with CSFV during late gestation and clarify the nature of infected cells and the distribution of viral antigen in different tissues. A total of twenty-nine fetuses aged 82, 83 and 95 gestational days originating from three naturally CSFV infected sows were examined in this study. In all tested sows and their fetuses CSFV was detected using RT-PCR method. Immunohistochemistry method was used to detect viral antigen and monoclonal antibody WH303 was used on formalin fixed tissue samples of brain, spleen, heart, tonsils, kidney, ileocecal valve and umbilical cord. The most common lesions in the majority of fetuses were hyperemia, petechial haemorrhages in the skin, lymph nodes and kidneys. With the exception of myocardium, CSF viral antigen was detected in all the examined tissues. WH303 positive cells included endothelial cells, monocytes, macrophages and lymphocytes. The largest number of positive cells was found in kidneys in all of the examined fetuses. Reticular cells, macrophages, lymphocytes and endothelial cells in the spleen were also intensely and widely stained in most of the fetuses. These results showed that CSFV antigen can be detected in formalin-fixed, paraffin-embedded fetal tissue specimens originating from naturally CSFV infected sows by using monoclonal antibody WH303. Fetal kidneys proved to be a very useful organ for diagnosis of the CSF virus. Having that in mind, it is assumed that persistently infected piglets may shed a high amount of viral particles through urine. However, further research is needed to confirm this hypothesis.

THE FIRST STUDY OF THE ENDOPARASITIC FAUNA OF MUTE SWANS (CYGNUS OLOR) IN THE NORTHERN PART OF SERBIA

In the Northern part of Serbia, which is part of Pannonian Basin, mute swan (Cygnus olor) population has notably increased over the last few decades. Like other birds from Anatidae family, mute swans are a host of numerous endoparasite species. The aim of this study was to acquire the data on identification and prevalence of endoparasites in mute swans in the Republic of Serbia, as that information is lacking. Individual faecal samples of sixty-eight adult mute swans were examined for the presence of endoparasites. Coprological examination was performed using flotation and sedimentation technique with saturated ZnSO4 solution. The samples were collected from December 2016 to March 2017, during epizootic of highly pathogenic avian influenza H5N8 in the Republic of Serbia. Dead mute swans were collected from twelve different locations in the Northern part of Serbia. Altogether, 39.7% of the examined fecal samples contained different parasites. The endoparasitic fauna was divers and included 3 species of nematodes, 2 cestodes species, one trematode and one protozoan species. Nematodes were the most prevalent helminthes and among these the most frequent nematode species found was Heterakis dispar (17.6%), followed by Echinuria uncinata (5,8%) and Ascaridia spp. (4,4%). Four mixed infections were found, where double infection was the most prevalent. No endoparasites were found in faecal samples of mute swans collected from the locations Sombor and Titel. As this study covers a small population of mute swans, more detailed studies need to be carried out on a larger population in order to gain an insight into the diversity and prevalence of endoparasites in the Republic of Serbia.

Neethling vaccine proved highly effective in controlling lumpy skin disease epidemics in the Balkans

Despite the wide use of the live attenuated Neethling lumpy skin disease (LSD) vaccine, only limited data existed on its efficacy and effectiveness prior to the large LSD epidemic in the Balkans, which took place during 2016-2017. In addition, analysis of risk factors for the disease was hardly performed with proper control for vaccination effects and potential differences in exposure to the virus. Data from the LSD epidemics in six Balkan countries (Bulgaria, Greece, Serbia, Montenegro, Former Yugoslav Republic of Macedonia (FYROM) and Albania) affected during 2016 were analyzed to determine vaccine effectiveness (VE) and risk factors for LSD infection at the farm level. Vaccination was performed along the occurrence of the epidemics and thus vaccination status of some of the farms changed during the epidemic. To allow for this, left truncated and right censored survival analysis was used in a mixed effects Cox proportional hazard regression model to calculate VE and risk factors for LSD. The results indicated of an average VE of 79.8% (95% CI: 73.2-84.7)) in the six countries, with the lowest VE of 62.5% documented in Albania and up to VE of more than 97% as documented in Bulgaria and Serbia. Analysis of time from vaccination to development of protective immunity showed that VE mostly developed during the first 14 days after vaccination. Data from Greece showed that the vaccination adjusted hazard ratio for LSD was 5.7 higher in grazing farms compared to non-grazing farms. However, due to a difference in geographical location of grazing and non-grazing farms and higher vaccination rate in non-grazing farms, this effect can be at least partly attributed to indirect protection due to herd immunity provided by surrounding vaccinated farms.

PHYSICOCHEMICAL CHARACTERISTICS OF SERBIAN HONEYDEW HONEY

Th e aim of this study was to investigate the composition and quality of Serbian honeydew honey. For this purpose, the physicochemical characteristics of 14 honeydew samples were analyzed. Th e physicochemical characteristics of all honeydew honeys from Serbia analyzed in this research can be considered to be within the parameters prescribed for honeydew in general. Th e sum value of glucose and fructose, the content of sucrose, water, hydroxymethylfurfural, acidity, and diastase activity were in line with European and national regulations for honey, for all investigated honeydew samples. Out of a total of 14 tested honey samples, 1 sample did not comply with the national regulations for honey regarding electrical conductivity. According to our results, in most of investigated samples the fructose/glucose (F/G) ratio was greater than 1.11 and glucose/water (G/W) ratio was close to 2. Th is means that they can be categorized as medium-crystallizing honeys. Th e results obtained in this study indicate excellent quality, absence of undesirable fermentation, acceptable freshness and proper manipulation of Serbian honeydews.

Molecular survey of Dirofilaria species in stray dogs, red foxes and golden jackals from Vojvodina, Serbia

Cardiopulmonary dirofilariosis in dogs and other carnivores is caused by Dirofilaria immitis, while Dirofilaria repens usually causes a subcutaneous infection. The importance of red foxes and golden jackals in the epidemiology of dirofilariosis remains unknown. Thus, the aim of this study was to conduct a cross-sectional molecular survey of Dirofilaria species in stray dogs, red foxes and golden jackals from the endemic region of Vojvodina, Serbia, in order to determine and update data on their prevalence and provide insight into the epidemiological importance of wild canids. A total of 59 blood samples from stray dogs, 94 from red foxes and 32 from golden jackals were collected and screened by real-time PCR targeting a 115-bp fragment of the mitochondrial 12S gene of filarioids and by conventional PCR assay targeting a 484-524-bp fragment of 5.8S-ITS2-28S locus of filarioids. The cross-sectional molecular survey detected the filarioid mitochondrial 12S gene fragment in stray dogs (27.1 %), red foxes (8.5 %) and golden jackals (6.3 %) in the same endemic region of Vojvodina, Serbia. Only D. immitis was detected in stray dogs, while both D. immitis and D. repens were detected in populations of red foxes and golden jackals. These results outline a possible interaction of D. immitis infection between the dog population and the wild canid populations, while D. repens was found to circulate mostly in golden jackals and red foxes populations.

Comparative pathological findings in mute swans (Cygnus olor) naturally infected with highly pathogenic Avian influenza viruses H5N1 and H5N8 in Serbia

The aim of this study was to compare pathological lesions and viral antigen expression in the organs of mute swans (Cygnus olor) naturally infected with highly pathogenic avian influenza virus subtypes H5N1 and H5N8. The examination was conducted on the carcasses of 22 mute swans which died during the avian influenza outbreaks in Serbia in 2006 and 2016-2017. Avian influenza virus subtype H5N8 isolated from mute swans in 2016-2017 was clustered within the 2.3.4.4 clade group B. After necropsy, lung, liver, spleen, pancreas, kidney and brain tissues were sampled for histopathology and immunohistochemical examination. Avian influenza virus nucleoprotein polyclonal antibodies were used for detecting the viral antigen in the examined tissues. The most significant gross lesions were necrosis and haemorrhages in the pancreas. Major histological lesions were multifocal necroses in the pancreas, spleen and liver, non-purulent encephalitis, lung congestion and oedema. Immunohistochemical demonstration of HPAIV nucleoprotein in pancreas and brain was strongly consistent with histological lesions in both infected groups. Our findings showed that pancreas was the most affected organ in all examined mute swans. In addition to increased mortality rate, similar pathological findings were detected in mute swans naturally infected with highly pathogenic avian influenza viruses H5N1 and H5N8.

Seroprevalence and spreading of Brucella ovis in South Bačka and Srem District

Ovine brucellosis can cause epididymitis and reduce fertility in rams and therefore is an important disease in sheep and rams from economic point of view. Sometimes it causes abortions and increased perinatal mortality in sheep as well, but it primarily affects male animals. Brucella ovis was first identified in northern region of Serbia, in 2008-2009 during a research study. Specific antibodies against Brucella ovis were detected in the sheep that originated from Becej and Titel municipalities in the South Bačka district. The prevalence was low, only 0.89%. For the purpose of this study, a total number of 6,407 serum samples from rams and sheep were used. All of the samples were from the northern part of Serbia, belonging to South Bačka and Srem districts. Serological test was performed in order to determine the presence of specific antibodies against Brucella ovis in rams and sheep, by ELISA test (indirect ELISA - iELISA). The prevalence varied from 0% - 19.3% during the years. If we look into the municipalities of South Bačka and Srem district, we can see that the numbers of positive samples are different, and the number of analyzed samples varies. The overall seroprevalence from 2014-2018 in South Bačka and Srem district is 6.15%, but it varies significantly among different municipalities from 0 to 26%. The majority of analyzed sample were from rams and all of the positive findings are in rams. Only a small number of sheep (female) has been examined so far, so the prevalence among females is still unknown.

Poisoning of domestic carnivores by banned pesticides in South Bačka district

Cases of deliberate, illegal animal poisoning are widely documented in the literature. Recently, there has been an increase in number of cases of poisoning of domestic and wild animals with highly toxic pesticides in the Republic of Serbia. During the two-year period (2016-2017), in total 40 autopsies of dogs and 2 cats from the territory of the South Bačka District were performed at the Department of Pathology at Scientific Veterinary Institute “Novi Sad” to determine the cause of death. Reasonable suspicion of poisoning in 13 dogs and 2 cats was made based on anamnestic data. The expertises were performed on request of the Republic veterinary inspector in 5 cases, and on the request of the owner in 8 cases. After autopsy, liver, kidneys and stomach content were sampled for toxicological analysis. The presence of carbofuran was determined in three dogs and one cat and the presence of 4,6-dinitro-ortho-cresol in one dog by method of gas-mass chromatography. In these cases of poisoning, on the basis of anamnestic data, clinical picture and autopsy finding it was concluded that poisonings were deliberate. Although the number of confirmed cases of domestic carnivores poisoning during the two-year period is relatively low, it is assumed that the number of undetected and undiagnosed poisoning cases is much higher. Abuse of highly toxic pesticides can have severe consequences for both public health and the overall biodiversity.

The Role of Myofibroblasts in Granulomatous Lymphadenitis in Pigs Naturally Infected with M. Avium Subsp. Hominissuis

The most important morphological characteristic of infections caused by M. avium subsp. hominissuis (MAH) is granuloma formation. The growth of mycobacteria is in accordance with anti-bacterial effector mechanisms of the host within granuloma. The most important cytokines for „orchestrating“the host defense are interferon γ (INF-γ), tumor necrosis factor α (TNF-α) and transforming growth factor β1 (TGF-β1). Myofibroblasts that make up a peripheral layer of granuloma largely express receptors for TGF-β1. This cytokine is believed to affect the induction of myofibroblast proliferation. The aim of this paper is to point out the importance of myofibroblasts in the formation and sustainability of granuloma during natural infection of pigs with M. avium subsp. hominissuis. Examinations have been performed on the samples of Lnn. jejunales, Lnn. ileocolici and Lnn. colici of 100 pigs with a positive tuberculin skin test. The molecular method confirmed the presence of a genome M. avium subsp. hominissuis. The microscopic examination of lymph node samples stained by the routine hematoxyilin-eosin (HE) method, showed the presence of granulomatous lymphadenitis. The method of double immunohistochemical staining revealed that myofibroblasts which express TGF-β1 receptor type I (TGF-β1RI) and α smooth muscle actin (α SMA) have an important role in the morphogenesis of granulomatous lymphadenitis in pigs infected with MAH.

PATOLOŠKE PROMENE KOD LABUDOVA INFICIRANIH VISOKO PATOGENIM SOJEM VIRUSA AVIJARNE INFLUENCE (H5N8)

Od 2014 godine nekoliko epizootija izazvanih visoko patogenim virusom avijarne infl uence podtipa H5N8, izbilo je u Aziji, Evropi i severnoj Americi. Ovaj tip virusa infl uence uzrokovao je infekcije domaće živine i divljih ptica. Globalnom širenju virusa doprinele su intrakontinentalne i interkontinentalne migracije ptica. Prvi slučaj visoko patogene avijarne influence podtipa H5N8 u Srbiji detektovan je kod labudova (Cygnus olor),lociranih na rukavcu Dunava (područje Koviljskog-Petrovaradinskog rita) u novembru 2016.godine. Tokom ove epizootije, veći broj bolesnih i uginulih labudova pronađen je oko staništa migratornih ptica. Pokazalo se da su labudovi tokom epizootije bili visoko osetljiva i najviše pogođena vrsta ptica virusom infl uence podtipa H5N8. Oboleli labudovi su ispoljavali neurološke simptome, uključujući tortikolis, inkoordinaciju i ataksiju. Uovom radu su predstavljeni rezultati postmortalnog pregleda labudova inficiranih virusom infl uence. Ispitivanje je rađeno na leševima deset uginulih labudova. Najdominantnije patološke promene izazvane virusom influence podtipa H5N8 bile su nekroze pankreasa, petehijalna krvarenja u subepikardijumu i masnom tkivu mezenterijuma. Kod većine uginulih labudova bila je prisutna kongestija pluća.

Mycobacteriosis in Pigs – An Underrated Threat

Although Mycobacterium avium subspecies are generally not considered food pathogens, the infections caused by these particular nontuberculous mycobacteria (NTM) can represent a serious threat to immunocompromised population. Additionally, infections with a member of Mycobacterium Avium Compex (MAC) can affect the efficiency of BCG vaccines used for the humans. In infected animals, M. avium may be present in different tissues without apparent clinical symptoms and macroscopic lesions. Veterinary meat inspection would then fail to recognize infected animals and such meat and meat products thereof could enter the human diet. The aim of this paper is also to analyze the current control policy in Europe according to infections of pigs with the members of MAC, and point out the risks for public health. By analyzing a large number of meat samples and other dietary nutrients, different groups of authors have provided evidence to support the hypothesis that M. avium is present in the everyday environment. Therefore, food as a source of infection with mycobacteria should not be ignored. The control of mycobacteria requires a better diagnostic approach, having in mind recent positive cases of M. avium subspecies hominissuis (MAH) in an increasing number of exported pigs from EU countries to Serbia. The introduction of reliable diagnostic methods for MAH could result in decreasing the occurrence of infection in pigs, as well as in humans, having in mind that WHO reported 10 million new cases of tuberculosis-mycobacteriosis in the human population in 2015 with 21% of these cases occurring in immunocompromised individuals and children.

Mastitis associated with Prototheca zopfii - an emerging health and economic problem on dairy farms

Increased incidence of protothecal mastitis has been recorded in several countries in the past ten years. The main goal of this article is to draw the attention of scientific and professional community to the emerging issue of mammary protothecosis. The article collates currently known facts about infection reservoirs, predisposing factors for the development of mastitis, clinical manifestations of the disease, and potential transmission routes within the herd as well as the measures for control and eradication. We would like to point out that identification of protothecal mastitis on a dairy farm is associated with a range of problems. Early detection of infected animals can be difficult because of predominantly subclinical course of early-stage infection, which easily spreads between cows via the milking system. Spontaneous recovery has not been recorded and infected cows typically develop chronic mastitis with granulomatous infiltration and progressive loss of functional parenchyma of the mammary gland. Substantial economic losses and health damages associated with mammary protothecosis strongly emphasise the need for developing effective prevention strategies aimed at control of the infection.

MALIGNANT TUMOURS IN LABRADOR RETRIEVERS USED FOR NARCOTIC DETECTION

The two corpses of police dogs, of Labrador retriever breed used for fi nding narcotics, were sent to the Scientifi c Veterinary Institute “Novi Sad”, and examined post-mortem, in order to determine the cause of death. Post-mortem examination revealed the presence of neoplastic changes inthe mandibular region, pulmonary parenchyma and axillary region. The samples of neoplastic changes were sent to the Laboratory of Patohistologywithin the Faculty of Veterinary Medicine, University of Belgrade, in order to specify the diagnosis. Histopathology examination revealed an adenocarcinoma in lungs and haemangioendothelioma in axillary region. Is there any role of drug sniffi ng on the occurrence of neoplasia in Labrador retriever breed is still unknown, but it could be an important factor in the development of neoplasia in these dogs.

PROSPECTIVES AND NECESSITY OF ERADICATION OF INFECTIOUS BOVINE RHINOTRACHEITIS / INFECTIOUS PUSTULAR VULVOVAGINITIS IN THE REPUBLIC OF SERBIA

Infectious bovine rhinotracheitis/infectious pustular vulvovaginitis (IBR/IPV) is a disease aff ecting cattle population of all breeds, categories and age. Th e disease can take diff erent clinical courses, infectious bovine rhinotracheitis (IBR) and infectious pustular vulvovaginitis (IPV) being the most common ones. Both diseases, an especially infectious bovine rhinotracheitis (IBR), pose severe health threat and cause major economic losses and are considered one of the most costly diseases in cattle industry. The causal agent is a virus categorized into the family Hepesviridae and designated as bovine herpesvirus type 1 (BHV-1) or IBR/IPV virus. Any positive result to IBR/IPV specifi c antibodies in non-vaccinated cattle, in either blood or milk, indicates the infection, and the animal is considered a source of infection. In this article, we described the needs and prospects for the eradication of IBR/IPV in the Republic of Serbia. The eradication of IBR/IPV is a complex process implying strictly defi ned program of measures. The implementation of such measures requires systematic strategy involving diff erent phases and activities that can continue over several years. The program requires substantial eff orts as well as fi nancial resources, which should be justifi ed and paid off through a successful eradication of IBR/IPV.

EPIZOOTIOLOGICAL IMPORTANCE OF SALMONELLA SPP. ISOLATED IN VARIOUS ASPECTS OF POULTRY PRODUCTION IN THE SOUTHERN BAČKA AND SREM REGION

Salmonella causes local and systemic infections of poultry, which may lead to substantial direct and indirect economic losses, presenting also significant risk to human health. Th e aim of this study was to monitor the occurrence of certain serotypes of Salmonella spp. isolated on poultry farmsin Southern Bačka and Srem regions in the period from 2010 to 2014, as recommended by the Book of rules of early detection, diagnostic, prevention of spreading and eradication of Salmonella spp. We analyzed the results obtained from the laboratory for clinical bacteriology to determine number of salmonella cases. From all samples that have been submitted for bacteriology analysis, salmonellas were isolated from 7.3% samples. Salmonella infantis was isolated from 50.3% of all salmonella-positive samples, mostly from materials supplied from broiler farms. Salmonella enteritidis was most frequently isolated in broiler chickens at the rate of 48.2%. Th ere is an increasing trend in the occurrence of Salmonella enteritidis and Salmonella infantis on poultry farms from year to year. Our research revealed the highest incidence of salmonella isolates in broilers that died during transportation or within the fi rst three days upon arrival of chickens. During the five-year research period, 65 samples from parent fl ocks (63 from broiler breeders and 2 from parent fl ocks of layers) were salmonella positive, which makes 8.03% of all positive isolates. It is most likely that salmonella infection occurs due to infection of parent flocks and young chickens are infected trough both vertical and horizontal transmission.

PROPOSAL OF A PROGRAM FOR CONTROL, SUPPRESSION AND ERADICATION OF BOVINE VIRAL DIARRHEA VIRUS INFECTION IN CATTLE HERDS IN THE REPUBLIC OF SERBIA

Bovine Viral Diarrhoea (BVD) is a viral infection of cattle caused by Bovine Viral Diarrhoea Virus (BVDV). Th e most important source of infectionis persistently infected and sick cattle, but also other susceptible species. BVDV infection, except for cattle, occurs in sheep, pigs, goats and wild ruminants. Th ese animals can be reservoirs of the virus, and thus the source of infection. Th e greatest economic losses caused by BVDV infectionin cattle farming are the direct consequences of transplacental infection, as a result of foetal deaths, congenital malformations, neonatal and postnatal mortality, including mucosal diseases and slow growth and poor performance results of the surviving animals, as well as acute infections of respiratory and alimentary infections. Economic losses due to BVDV infection can be seen in a cattle herd even several years aft er the infection. Moreover, BVDV infection is considered as the third most important disease to cattle farming industry, immediately aft er rinderpest and the foot-and-mouth disease. Th e primary task of BVDV infection control is to prevent prenatal infection. This procedure includes the determination and elimination of persistently infected (PI) animals from the herd. Aft er the removal of these animals, great attention must be paid to introducing new animals into the herd and preventing the occurrence of transplacental infection. On the basis of existing data and real suppositions about the distribution of BVDV infection in the territory of Serbia, the great economic damages it causes, as well as the general tendency to resolve problems in European states, and for the competitiveness of our farmers and food industries in the production of milk, meat or breeding material after joining the EU market, it is necessary to draft legal regulations in the control of this bovine viral disease in Serbia. The mentioned control could be based on the voluntary BVDV eradication program on herd’s level in the beginning and on establishing herds with BVDV free status. Certifi cation of BVDV free status of herd will be done by Veterinary Directorate, and the register of herds with BVDV free status could be “on line” available and maintained by the Veterinary Directorate. The essence of this proposal, a volunteer program of establishing herds with BVDV free status, is based on several steps or phases, which includes frequent diagnostic testing, removal of PI animals from the herd and the introduction of strict biosecurity measures.

Endoparasitic fauna of red foxes (Vulpes vulpes) and golden jackals (Canis aureus) in Serbia

Wild canides have a high epizootiological - epidemiological significance, considering that they are hosts for some parasites which spread vector born diseases. Increased frequency of certain interactions between domestic and wild canides increases the risk of occurrence, spreading and maintaining the infection of parasitic etiology in domestic canides. The research was conducted in 232 wild canides (172 red foxes and 60 golden jackals). The examined material was sampled from foxes and jackals, which were hunted down between 2010 and 2014, from 8 epizootiological areas of Serbia (North-Bačka, West-Bačka, Southern-Banat, Moravički, Zlatiborski, Raški, Rasinski and Zaječarski district). On completing the parasitological dissection and the coprological diagnostics, in wild canides protozoa from the genus Isospora were identified, 3 species of trematoda (Alaria alata, Pseudamphistomum truncatum and Metagonimus yokogawai), cestods from the genus Taenia and 5 species of nematodes (Toxocara canis, Ancylostomatidae, Trichuris vulpis and Capillaria aerophila). The finding of M. yokogawai in golden jackals were, to the best of our knowledge, one of the first diagnosed cases of metagonimosis in golden jackals in Serbia. The continued monitoring of the parasitic fauna of wild canides is needed to establish the widespread of the zoonoses in different regions of Serbia, because they present the reservoirs and/or sources of these infections.

Investigation of Biofilm Formation and Phylogenetic Typing of Escherichia Coli Strains Isolated from Milk of Cows with Mastitis / Ispitivanje Formiranja Biofilma I Filogenetska Tipizacija Sojeva Escherichia Coli Izolovanih Iz Mleka Krava Sa Mastitisom

Escherichia coli is an opportunistic pathogen affecting bovine mammary gland causing mainly transient infections; however, some recent reports indicated that some strains are able to adhere to and internalize into the epithelial cells, which can result in the persistence of the pathogen in the tissue and development of recurrent mastitis. The mechanism of adaptation of E. coli to the mammary gland relies on structures that are distinctive components of its extracellular matrix - curli fimbriae (proteinaceous component) and cellulose (polysaccharide). Expression of these components varies among the isolates. In this study, we investigated the capacity of expression of curli fimbriae and cellulose (via colony morphotype on Congo Red agar) and ability of biofilm formation (microtiter plate test) in 25 strains of E. coli isolated from milk of cows with clinical mastitis. Phylogenetic grouping of the isolates was performed using PCR method based on detection of chuA, yjaA and TspE4-C2 amplicons. Antimicrobial susceptibility was examined using standard disk diffusion test. Production of both extracellular matrix components was established in 56%, and expression of curli fimbriae in 64% E. coli isolates. All isolates that produced curli fimbriae, demonstrated this ability at a temperature of 37°C, indicating the potential role of these adhesive structures in the pathogenesis of mastitis. The results of phylogenetic typing confirmed that E. coli strains isolated from milk of cows with mastitis are typical commensals mainly belonging to phylogenetic groups A and B1. All curli and curli/cellulose producing isolates formed biofilm under in vitro conditions. The biofilm potentially plays an important role in the development of persistent infections as well as recurrent clinical symptoms after antibiotic therapy in spite of quite good in vitro antimicrobial susceptibility of the agent.

Investigation of an outbreak of mycobacteriosis in pigs

Background

A high proportion of pigs imported to Serbia from a Lithuanian breeding herd reacted positively against avian and/or bovine tuberculin. The pigs were euthanized and lesions characteristic for mycobacterial infection were detected. An investigation of potential mycobacteriosis in the pigs imported to Serbia and the possible source of infection in the Lithuanian herd were therefore initialised.

Results

Formalin fixed, paraffin embedded lymph nodes from tuberculin positive animals were examined by real-time PCR for IS1245 and IS6110. IS1245 was detected in 55% and IS6110 in 11% of the samples. Seven of the ten IS6110 positive samples were positive for IS1245. Eleven lymph nodes from 10 pigs and 15 environmental samples were collected from the Lithuanian breeding herd and cultured for mycobacteria. M. avium subsp. hominissuis was detected in all lymph nodes and from eight samples of peat and sawdust. Isolates with identical and related IS1245- and IS1311 RFLP profiles were detected from swine and peat.

Conclusions

This study demonstrated cross reactions between avian and bovine tuberculin in pigs. Real-time PCR indicated infection with M. avium in the Serbian pigs. However, as a small proportion of the lymph nodes were positive for IS6110, infection with bacteria in the M. tuberculosis complex could not be ruled out. Analyses confirmed the presence of M. avium subsp. hominissuis in porcine and environmental samples from the Lithuanian breeding herd. The results indicate peat as a source of M. avium subsp. hominissuis infection in these pigs, and that the pigs imported to Serbia were infected with M. avium subsp. hominissuis.

PREVALENCE OF HERPESVIRUS 1 IN SMALL HERDS IN SOUTHERN BAČKA AND SREM DISTRICT

Bovine herpesvirus type 1 infection (IBR/IPV virus) presents the most spread infection in nowadays cattle breeding. Bovine herpesvirus-1 (BHV-1) may be an agent of serious health disorders causing great economic losses. Since the largest number of cattle in Southern Baåka and Srem district are raised in small herds (what may considerably influence effective implementation of program for control and eradication of BHV-1 infection) it was necessary to investigate the prevalence of BHV-1 infection in the cattle population in this area, what was the aim of this work. Detection and estimation of the presence and prevalence of BHV-1 was done by detection of specific antibodies against BHV-1 in sera samples of cattle raised individually or in small herds (up to 20 animals) collected during the State Program of Disease Control in 2005 and 2006. The sampling was randomly carried out taking care that the samples from all the settlements and municipalities in Southern Bačka and Srem were present. A total of 16,610 samples was collected. Animals seropositive for BHV-1 were detected in all municipalities, but not in all settlements. The highest percent of seropositive animals was found in Beočin municipality(27.27%), Titel municipality (27.16%), Žabalj (22.45%) and Stara Pazova municipality (22.15%). The lowest prevalence was in Bački Petrovac (8.16%) and Temerin municipalities (9.68%). In other municipalities the prevalence ranged between 10% and 20%. From the obtained results it can be concluded that BHV-1 infection was not present in 10 settlements in Southern Bačka and 14 settlements in Srem district. In other settlements (151) the percentage of seropositive animals ranged from 1 to 50%. However, if we analyze the obtained results in the area, it may be concluded that the prevalence is almost the same: in Srem district there were 18.42% and in Southern Bačka 18.79% seropositive animals. Low prevalence was detected in the majority of settlements. The data that in 24 settlements in both districts there were no seropositive animals His an encouraging information. This points on a possibility of easier and faster implementation of control measures and eradication of BHV-1 infection. The results obtained in serology examination provide us an insight in immunology status of small herds in Southern Bačka and Srem districts, what is a starting point in designing and implementing necessary measures with the aim to prevent cases of this disease, as well as its spreading and eradication.