SUGGESSTED MODEL FOR MONITORING AND CONTROL OF FOODBORNE PATHOGENS IN WILD BOAR'S MEAT

Wild animal meat harvesting and processing is signifi cantly different from classical livestock meat production and represents a challenge by itself.Implementation of concept “from forest to fork” encompasses influence of hunting ground ecology, type of hunting, fi eld evisceration of hunted game, meat inspection aft er shooting or transport etc. The objective of this paper was to propose a model for monitoring and control of food born pathogens in wild boar´s meat. Hazard analysis emphasized the importance of several pathogens: Mycobacterium spp., Salmonella spp., Trichinella spp., and a fi ve-step control program were proposed. The program includes management of microbial contamination of wild boar meat, control measures for live animals, control measures during hunting and aft er shooting, guidelines for offi cial meat inspection with specific details for control of identifi ed hazardous pathogens and control measures for wild boar carcasses processing. Th e research on presence of food born pathogens in wild boar meat is still scarce, while the Trichinella spp. live cycle is well described and there are relevant data about epidemiology and natural reservoirs of the parasite in this part of Europe, little is known about tuberculosis and salmonellosis prevalence in wild boar population. Thus, implementation of control program, with strictly defi ned control measures cannot be overemphasized, and should include veterinary offi cials as well as hunters and others involved in game meat chain.

THE ROLE OF EFFLUX PUMP AND OTHER MECHANISMS OF ANTIMICROBIAL RESISTANCE TO (FLUORO)QUINOLONES IN EPIDEMIC ISOLATES OF SALMONELLA TYPHIMURIUM, SALMONELLA KENTUCKY AND SALMONELLA INFANTIS

This paper briefly describes mechanisms of resistance to fluoroquinolones in several worldwide distributed Salmonella clones. The isolates have acquired multiple resistance traits over the years due to extensive antibiotic treatment both in human and veterinary medicine. Except for the Salmonella Typhimuirum DT104 where effl ux pump appears to play a major role in resistance to (fluoro)quinolones, in other serovars mutations on topoisomerase genes seem to fi rstly occur and have been primary mechanisms of resistance. Plasmid borne resistance is rarely detected but because of horizontal gene transfer needs to be recorded. Understanding the genetic events at the molecular level is crucial in epidemiology work and provides insight in spreading of resistance clones of Salmonella.

Chemometric approach for prediction of uranium pathways in the soil

Understanding the effect of soil parameters (pH, Eh and organic and inorganic ligands availability) on uranium mobility under different geochemical conditions is fundamental for reliable prediction of its behaviour and fate in the environment. In this study, the impact of total and available phosphorus content, humus and acidity of Serbian agricultural soils on the content of total and available uranium were evaluated by Response Surface Methodology (RSM), second order polynomial regression models (SOPs) and artificial neural networks (ANNs). The performance of ANNs was compared with the performance of SOPs and experimental results. SOPs showed high coefficients of determination (0.785–0.956), while ANN model performed high prediction accuracy: 0.8893–0.904. According to the results, total and available uranium content in the soil were mostly affected by pH, statistically significant at p < 0.05 level. For the same responses the total phosphorus was found to be also very influential, statistically significant at p < 0.05 and p < 0.10 levels. The impact of available phosphourus and humus was much more influential on total and available uranium content, compared to total phosphorus content. Proposed chemometric approach will be very helpful in preserving the natural resources and practical application for risk assessment modeling of uranium environmental pathways.

FANDING OF PARASITIC NEMATODES OF FISHES PRESENT IN THE MARKET

When placing the fish and fish products on the trade it is necessary to pay attention to the presence of zoonotic parasites that can lead to infection of people especially if the fish is consumed raw or undercooked. Epidemiologically the most important are helminths from the group of Nematoda. The most important are Anisaxis spp. and Eustrongylides excisus. Anisakiasis is a serious zoonotic disease with a dramatic increase in prevalence throughout the world in the last two decades. The larvae are found in marine fish species most frequently in sardines, herring and mackerel. Eustrongylidosis is a disease that occurs primarily in freshwater fish species: catfish, zander and pike, a cause is a parasite of the genus Eustrongylides of which the most important species is Eustrongylides excisus. In this paper, the nematodes that occur in fish that are present in the market in the Republic of Serbia are present. Investigations of Anisaxis spp. were carried out at the Institute of Veterinary Medicine Novi Sad in the period of 2000-2013. Total of 2414 samples of imported marine fish was inspected. In 25 (1.29 % ) samples of herrings (Clupea harengus ) and mackerels ( Scomber scombrus ) was identified Anisakis spp. Investigations of Eustrongylides spp . were carried out in the period 2010-2013 at the Danube- Tisa -Danube Canal. Samples were collected from zander (Sander lucioperca) and European catfish (Siluris glanis) in which the presence of nematodes was found in the abdominal cavity, muscles, the lumen of the stomach and gastric wall where the parasites were encapsulated. Individuals of zander were examined during the 2013 at the Veterinary Institute Novi Sad, where the presence of larvae Eustrongylides spp.u muscle was detected. In order to avoid infecting people with parasites of fish it is necessary to carry out continuous control and monitoring. Fresh fishes and traditional fish products must be inspected for the presence of parasites before they find on the trade. Continuous education is a key factor in combating zoonotic diseases. Avoid consumption of raw or poorly cooked fish is still the best preventive procedure.

CHARACTERISTICS OF HUMAN TRICHINELLOSIS IN THE TERRITORY OF VOJVODINA IN THE PERIOD 2002-2011

Current data on the incidence of the disease and abundant research strongly indicate that Trichinellosis has been widely present throughout past few decades, and is endemic in some regions of Serbia. Unfavourable epidemiological situation is due to high prevalence of infection sources and inadequate control of home-processed meat and meat products. The aim of this article was to describe the features of recorded trichinellosis outbreaks in Vojvodina according to gender structure of patients, based on the records obtained from the Institute for Public Health of Vojvodina in Novi Sad. Analysis of the number of diseased and hospitalized patients from the territory of Autonomous Province of Vojvodina in the ten-year period (2002-2011) revealed a total number of 983 patients with trichinellosis. The highest incidence of the disease was recorded in 2005, when 277 people were diagnosed with trichinellosis. Unfavourable epidemiological situation was observed also in 2002, with 275 aff ected patients. It is to be emphasized that in 2002 and 2005 three lethal outcomes were recorded, as a direct consequence of intensive migration and abundant invasion of T.spiralis larvae. Th e lowest incidence of the disease was recorded in 2010, that is, only 10 diseased patients. Primary prevention implying appropriate animal husbandry is the crucial point for the disease control, while thorough and systematic inspection of meat of home-produced pigs, wild boars, horses and other animals that can be a potential source of infection. The major risk factor for the occurrence of the disease is consuming raw or undercooked meat that was not subjected to standard examination methods, i.e. examining the skeletal striated musculature from predilection sites by trichinoscopy or artifi cial digestion.

Spatial distribution and vertical migration of (137)Cs in soils of Belgrade (Serbia) 25 years after the Chernobyl accident

In this study, the specific activity of (137)Cs was determined by gamma-ray spectrometry in 72 surface soil samples and 11 soil profiles collected from the territory of Belgrade 25 years after the Chernobyl accident. Based on the data obtained the external effective gamma dose rates due to (137)Cs were assessed and geographically mapped. The influence of pedogenic factors (pH, specific electrical conductivity, cation exchange capacity, organic matter content, soil particle size and carbonate content) on the spatial and vertical distribution of (137)Cs in soil was estimated through Pearson correlations. The specific activity of (137)Cs in surface soil samples ranged from 1.00 to 180 Bq kg(-1), with a mean value of 29.9 Bq kg(-1), while in soil profiles they ranged from 0.90 to 58.0 Bq kg(-1), with a mean value of 15.3 Bq kg(-1). The mean external effective gamma dose at 1 m above the ground due to (137)Cs in the soil was calculated to be 1.96 nSv h(-1). Geographic mapping of the external effective gamma dose rates originating from (137)Cs revealed much higher dose rates in southern parts of Belgrade city and around the confluence of the Sava and Danube. Negative Pearson correlation coefficients were found between pH, cation exchange capacity and (137)Cs specific activity in surface soil. There were positive correlations between organic matter and (137)Cs specific activity in surface soil; and between specific electrical conductivity, organic matter, silt content and (137)Cs specific activity in soil profiles.

Antimicrobial resistance of Escherichia coli in wild animals

The paper presents the recent finding of resistance phenotype and distribution of resistant genes in Escherichia Coli (E. coli) isolated from wild life. The resistance distribution was depended on animal species, their natural habitat, and some seasonal variations were also evident. Wild animals residing close to the farms were more often spreaders of resistant bacteria than those found in nature. It was shown that humans have an important role in appearance and dissemination of resistant E. coli in population of wild animals.

PLASMID MEDIATED RESISTANCE TO QUINOLONES IN SALMONELLA

Plasmid mediated resistance to quinolones in Salmonella enterica is briefly presented. World wide spread of qnr determinants is evident, indicating the necessity for prudent use of antimicrobials in human and veterinary medicine. In discovering plasmid mediated resistance to quinolones antimicrobial resistance monitoring for β-lactam antibiotics is helpful, since their target genes frequently coexist in plasmid. Nevertheless, 100% reliable method for screening of qnr determinants has not been discovered. The finding of qnr genes and other determinants from the large collection of Salmonella isolates in respective national laboratories, in several countries is described. Individual cases of qnr positive Salmonella from patients, reported in recent years, are also presented.

Optimization of matrix tablets controlled drug release using Elman dynamic neural networks and decision trees

The main objective of the study was to develop artificial intelligence methods for optimization of drug release from matrix tablets regardless of the matrix type. Static and dynamic artificial neural networks of the same topology were developed to model dissolution profiles of different matrix tablets types (hydrophilic/lipid) using formulation composition, compression force used for tableting and tablets porosity and tensile strength as input data. Potential application of decision trees in discovering knowledge from experimental data was also investigated. Polyethylene oxide polymer and glyceryl palmitostearate were used as matrix forming materials for hydrophilic and lipid matrix tablets, respectively whereas selected model drugs were diclofenac sodium and caffeine. Matrix tablets were prepared by direct compression method and tested for in vitro dissolution profiles. Optimization of static and dynamic neural networks used for modeling of drug release was performed using Monte Carlo simulations or genetic algorithms optimizer. Decision trees were constructed following discretization of data. Calculated difference (f(1)) and similarity (f(2)) factors for predicted and experimentally obtained dissolution profiles of test matrix tablets formulations indicate that Elman dynamic neural networks as well as decision trees are capable of accurate predictions of both hydrophilic and lipid matrix tablets dissolution profiles. Elman neural networks were compared to most frequently used static network, Multi-layered perceptron, and superiority of Elman networks have been demonstrated. Developed methods allow simple, yet very precise way of drug release predictions for both hydrophilic and lipid matrix tablets having controlled drug release.

THERAPEUTICAL USAGE OF FLUOROQUINOLONES IN POULTRY PRODUCTION INFLUENCE ON MEAT SAFETY – RESIDUES IN EDIBLE TISSUES

Current most important side effects of antimicrobial drugs usage are veterinary drug residues in edible animal tissues and development of resistance in food borne pathogens. Enrofloxacine and flumequine are fluoroquinolone antimicrobials licensed in Serbia for use in poultry treatment. Elimination of health risk for consumers is usually made by examination of the target tissue residues of flumequine and enrofloxacine (with its main metabolite ciprofloxacine). After correct application of enrofloxacine and flumequine tissue residue levels descrease to permitted quantities (below MRL) (Maximum Residue Limit) in prescribed withdrawal period. But even after expiration of withdrawal period residues of enrofloxacine are still present in edible animal tissues. Residues of enrofloxacine below MRL can be detected in meat nine days after the end of treatment, however, residues in liver are present much longer. The residues were detected in liver until 22nd post treatment day.

CONTROL OF ANTIBIOTIC RESIDUE IN MILK FROM FARM TO TABLE

Antibiotic residue in milk may have harmful consequences for humans and milk technology. In order to prevent adverse effects of residue, nowadays different screening methods are used for qualitative examination of antibiotic residue in milk. The aim of the work was to investigate the presence of antibiotic residue in the samples of milk from different phases of production chain (from raw material to final product) by using different screening methods. Three screening methods, that are most often used, were chosen. Microbiological inhibitory methods: Delvo SP test and diffusion method with B. stearothermophilus and enzyme method Penzyme S test. A total of 60 samples were examined. The samples were collected from whole milk production chain from farm to final product. The investigation determined high compatibility of tests. The differences that occur in examining the same sample using three different methods are a consequence of different sensitivity of the methods. Delvo SP test is sensitive to antibiotics, sulphonamides, disinfectants and inhibitory substances in milk (lactoferin, lactoperoxidase). Diffusion method is sensitive to antibiotics, while Penzyme S is sensitive only to β-lactam antibiotics. High coincidence of Penzyme S test with two other tests prove that β-lactam antibiotics are the most often residua that can be found in milk. The differences in results may also be a consequence of difference of detection limit for the same antibiotics. On the basis of performed investigation, it was detected that there is a high percent of milk sample that contain antibiotic residues 30% in bulk tanks on farms, 20% in cistern in diary and 20% in pasteurized and sterilized milk on the market. On the bases of parallel investigation of diffusion method, Delvo SP test and Penzyme S test, we can conclude that all three methods are extremely in agreement and thus they fulfill one of the criteria for introducing them in systematic milk control on presence of antibiotic residue.

Minor vs complete excision of pilonidal sinus--early postoperative period

Pilonidal sinus arises in the natal cleft of the sacrococcigeal region either as a cyst or as an abscess collection containing hair. It is predominantly a condition of younger people. When presenting as an abscess it usually requires surgical incision and drainage, or bursts spontaneously. In general, there are various surgical approaches to this condition, from very simple to complex ones. Each technique has its supporters and justifications. In the 3 years period, from 2009-2011, 110 treatments of the pilonidal disease were performed on our department. Midline excision was performed in 75 (68.18%) patients and the rest had marsupielisation done. The average discharge time was 1.14 days. Failure to heal occurred in 15 patients (13.63%). During that period we saw recurrence in 4 patients (3.63%). All the patients were coming to our department for postoperative care. The shortest healing time was 4 weeks and longest 21 weeks. During the period may 2011-May 2012 we performed 17 less extensive excisions. All the patients were discharged from the clinic within 23 hours and returned to their daily activities within 5 days. Healing time varied from 2 weeks to 5 weeks. In only one patient with the extensive excision healing time was 8 weeks. Although we had a short follow up period of 11.11 months, we saw no recurrence yet. Our results show that simple individual approach to every patients gives fastest and most comfortable results.

Use of vacuum-assisted closure device in a disastrous form of abdominal sepsis and stoma site infection: systematic review and report of a case

Use of Vacuum-Assisted Closure (VAC) for treatment of open abdomen has been established predominantly in cases of severe abdominal trauma, resulting with high percentage of primary fascial closure. The role of VAC technique in cases of severe diffuse peritonitis is not definitely incorrigible. However, in cases of severe complicated abdominal sepsis VAC come up as a last resort.

INFLUENCE OF ANTIMICROBIAL DRUG USE IN POULTRY BREEDING ON MEAT SAFETY

Recognition of food safety problems brings into focus the importance of primary production. Overuse of antimicrobial drugs in animal breeding is reality it is only a question in what manner and extent it influences on food safety. Use of antimicrobials can cause residues and herby influence safety of meat originating from treated animals. Besides residues, one of the most important and actual side effects is developing of resistance in food borne pathogens. After correct application of antimicrobial drugs tissue residue levels descrease to permitted quantities (below MRL) in  prescribed withdrawal period. But even after expiration of withdrawal period residues are still present in edible animal tissues. Residues of enrofloxacine can be detected in meat nine days after the end of treatment, residues in liver are present much longer. Residues were detected in liver until 22. post treatment day. Residues of florfenicole descrease in meat below MRL on third withdrawal day but in liver residues completely expire on seventh post treatment day, while in kidneys they can be still detected. After expiration of withdrawal period residues of florfenicole are still present in  edible animal tissues but in permitted quantities. In antimicrobial drug abuse or overuse it is impossible to apply correct withdrawal period this leads to high risk of appearance of dangerous meat on market.

MECHANISMS OF INCREASED RESISTANCE OF BACTERIA TO ANTIMICROBIALS IN BIOFILM

The most striking advantage of bacteria residing in biofilm is enhanced resistance to biocide including antibiotics and disinfectants. Biocides are 100% efficient in killing cells in suspension but there are not efficient in destroying bacteria from biofilm community. Mechanisms of increased resistance of bacteria in biofilm to antibiotics is not understood. Some factors alone or in combination are considered to be responsible such as restricted penetration of antibiotics into a biofilm, slow growth rate of biofilm cells, possible expression of certain resistance genes, increased rate of genetic transfer. The standard test for estimating the minimum bactericidal and minimum inhibitory concentration is not applicable for bacteria grown in biofilm. Nowadays, the apparatus for determination of Minimal Biofilm Eradication Concentration (MBEC) has been developed. Determining MBEC helps to select appropriate antibiotics for patient treatment, to identify new antimicrobials targeting biofilm and to track the possible future development of antibiotic resistance against biofilm drugs.

MODERN LABORATORY DIAGNOSTIC METHODS IN VETERINARY MEDICINE AND THE POSSIBILITY OF ITS APPLICATION

One of the greatest challenges of modern laboratory diagnosis is the selection of methods for fast, highly sensitive and specific detection of the infective agents. This challenge is present also in molecular diagnosing of causative agents in veterinary medicine. An example of molecular detection, the application of molecular diagnostic methods and procedures in the epizootiology of some viral infections is presented in the paper. The molecular methods play an important role in virus detection and surveillance. Out of a large number of molecular methods most frequently used are classical gel-based PCR (PCR, RT-PCR and nested PCR) and real-time PCR or RT-PCR techniques. Due to highly specificity and sensitivity these methods have been introduced as internationally recognized methods for virus detection in clinical materials. The advantage of the aforementioned molecular methods is that they are very fast and highly sensitive, and able to analyse a high number of samples. The obtained results may be used in molecular epizootiology, possibly for differentiation of filed isolates and vaccine virus strains, and for examining the samples not suitable for virus isolation. Alongside, these methods provide accurate quantification of viral particles in sample material. The detection with high sensitivity and specificity is of utmost importance in detection and typisation of the agents of highly contagious diseases and zoonoses. An example of rapid detection and sensitivity of RT-PCR and real-time RT-PCR in detection and characterization of avian influenza virus in clinical material as well as BVD virus in native bull semen is presented. Besides, molecular methods may be used for other purposes. Genome fragments amplified by PCR and RT-PCR, may be sequenced and used for classification, i.e. for virus isolate genotypisation. The results obtained in this way may be used for basic molecular research in epizootiology, that will point on the source of infections, their correlation and the prevalence of the causative agents what can help in finding the answer to the question why the diseases have occurred and what are the perspective for diseases outcome in the future. Also, these examination may help in determining pathogenicity, virulence and the spread of the pathogen agents. These information are of immeasurable importance for all the procedures in disease prevention and control. The possibilities of sequencing, molecular typisation and epizootiology of BVD virus and CSF virus isolated in Vojvodina in the last years are given as an example how this method can be used.

APPLICATION OF MICROPLATE BIOFILM ASSAY AND MICROSCOPY TECHNIQUES TO INVESTIGATE ABILITY OF SOME BACTERIAL STRAINS OF ANIMAL ORIGIN TO FORM BIOFILM

The use of some procedures for in vitro investigation of biofilm formation in bacterial species Staphylococcus aureus, Listeria monocytogenes and Pseudomonas aeruginosa isolated from animals is presented in this paper. Biofilms are formed on polystyrene and stainless steel surfaces. On polystyrene surface S. aureus and L. monocytogenes were examined by microplate biofilm assay and light microscopy. Biofilms of L. monocytogenes, S. aureus and P. aeruginosa, formed on stainless steel surface, were examined by scanning electron microscopy. The application of these methods can help distinguish between the bacteria isolates that don’t form and the one that form biofilm. Microplate biofilm assay proved to be a simple method suitable for examining a large number of isolates of the same or different bacteria species, particularly if used prior to other investigation techniques that require more complex procedure. The advantages of the test, among the others, is quantification of the obtained results, whereas a principal drawback implicates the impossibility of detecting extracellular substance. The microscopy techniques have provided a direct insight in the structures formed by the investigated strains on the used substrates, with some limitations. They are related to the poor resolution features and two-dimensional image obtained by light microscopy, as well as deformation of three-dimensional biofilm structures in the preparation for scanning electron microskopy.

MECHANISMS OF RESISTANCE TRANSFER IN BACTERIA

Wide application of antimicorbial agents forces bacteria to utilize specific genes and rearrange genomic structure in order to survive in the environment. In this article lateral gene transfer, mobile genetic elements, plasmid mediated resistance and spontaneous mutators in bacteria are briefly described. This resourceful means, by which microorganisms manage to communicate and transfer genetic material in their own kingdom, raises concerns about the possibility to keep microbial infections under control in the future.

Modelling of diclofenac sodium diffusion from swellable and water-soluble polyethylene oxide matrices

Objectives

The main objective of this study was to develop a mathematical model for the characterization of diclofenac sodium diffusion from polyethylene oxide (PEO) matrices. A model was developed on the basis of the diffusion theory accounting for the characteristics of the polymer: swelling with subsequent dissolution in water. The concentration-dependent diffusion of drug and water was taken into account. Experimental data were analysed using a computer software program as an aid for solving partial differential equations.

Methods

Six formulations of matrix tablets with different drug-excipient ratios were prepared using low-molecular-weight PEO as a matrix-forming material. For obtaining drug release data, dissolution studies were performed and water uptake by pure PEO matrices was studied as well.

Key findings

A good agreement of the developed model with experimental results was demonstrated. Some anomalies in drug diffusion were observed and their origin was questioned. Changes in the parameters characterizing the process of diffusion are attributed to glassy-rubbery polymer transitions. Additional interpretation of this phenomenon on the basis of percolation theory is also provided.

Conclusions

The obtained model has the ability to predict the required characteristics of matrices for desired drug release. The composition of batches with undesirable release properties can be predetermined and avoided in manufacturing.

Modelling of diclofenac sodium diffusion from swellable and water-soluble polyethylene oxide matrices

OBJECTIVES

The main objective of this study was to develop a mathematical model for the characterization of diclofenac sodium diffusion from polyethylene oxide (PEO) matrices. A model was developed on the basis of the diffusion theory accounting for the characteristics of the polymer: swelling with subsequent dissolution in water. The concentration-dependent diffusion of drug and water was taken into account. Experimental data were analysed using a computer software program as an aid for solving partial differential equations.

METHODS

Six formulations of matrix tablets with different drug-excipient ratios were prepared using low-molecular-weight PEO as a matrix-forming material. For obtaining drug release data, dissolution studies were performed and water uptake by pure PEO matrices was studied as well.

KEY FINDINGS

A good agreement of the developed model with experimental results was demonstrated. Some anomalies in drug diffusion were observed and their origin was questioned. Changes in the parameters characterizing the process of diffusion are attributed to glassy-rubbery polymer transitions. Additional interpretation of this phenomenon on the basis of percolation theory is also provided.

CONCLUSIONS

The obtained model has the ability to predict the required characteristics of matrices for desired drug release. The composition of batches with undesirable release properties can be predetermined and avoided in manufacturing.

QUALITY OF HOT DOG SAUSAGES

The volume of hot dog sausages plays an important role in meat production. Due to their desirable eating properties (softness, juicy, mild taste and smell) they form a group of sausages acceptable for all consumer categories. They are produced according to producer’s specification, which are not the same. Therefore, the differences in quality may be expected. The objective of this paper was to make a comparative analyses of three parameters in five different products present on Novi Sad market: the content of water, fat and protein, and to determine the average content of these parameters in hot dogs produced by different producers. The average content of water ranged from 56.29±3.30% to 61.44±4.08%. The differences between the average content of water in the product of producer A and C were with no statistic significance (p=0.05), and there was no difference between the average water content in other products. The average total fat in hot dogs ranged from 17.60±3.07% to 20.66±4.65%. The average fat content in the products of D and B producer, as well as Cand B, was without statistically significant difference (p=0.05). The average fat content in the products of producer E and D differed p=0.01. In all other comparisons the difference between the average fat content was p=0.001. The average meat protein content ranged from 11.77±1.08% to 15.41±1.82%. Between the products from producer A and C there was no statistical significant difference (p=0.05). The average meat protein content in the products of D and E producers showed statistic difference of p=0.01, but the average content in other producers was p=0.001. The content of meat protein in all hot dogs were within limits of regulations (10%). Statistically significant difference of the average water content in five different producers was discovered in one case (out of ten), the average fat content in two, and the average protein content in one of the examined products.