Antimicrobial activity of selected essential oils against selected pathogenic bacteria: In vitro study

The worldwide problem of infectious diseases has appeared in recent years, and antimicrobial agents are crucial in reducing disease emergence. Nevertheless, the development and distribution of multidrug-resistant (MDR) strains in pathogenic bacteria, such as Escherichia coli, Staphylococcus aureus, Salmonella Typhi and Citrobacter koseri, has become a major society health hazard. Essential oils could serve as a promising tool as a natural drug in fighting the problem with these bacteria. The current study aimed to investigate the antimicrobial effectiveness of tea tree (Melaleuca alternifolia (Maiden and Betche) Cheel), rosemary (Rosmarinus officinalis L.), eucalyptus (Eucalyptus obliqua L’Hér.), and lavender (Lavandula angustifolia Mill) essential oils. The antimicrobial properties of essential oils were screened against four pathogenic bacteria, E. coli, S. aureus, S. Tyhpi, and C. koseri, and two reference bacterial strains, while for the testing, the agar well diffusion method was used. Gas chromatography (GC) and gas chromatography–mass spectrometric (GC–MSD) analyses were performed on essential oils. The obtained results showed that M. alternifolia essential oil is the richest in terpinen-4-ol, R. officinalis and E. oblique essential oils in 1,8-cineole, and L. angustifolia essential oil in α-terpinyl acetate. In addition, the main bioactive compounds present in the essential oil of tea tree are rich in α-pinene (18.38%), limonene (7.55%) and γ-terpinene (14.01%). The essential oil of rosemary is rich in α-pinene (8.38%) and limonene (11.86%); eucalyptus essential oil has significant concentrations of α-pinene (12.60%), p-cymene (3.24%), limonene (3.87%), and γ-terpinene (7.37%), while the essential oil of lavender is rich in linalool (10.71%), linalool acetate (9.60%), α-terpinyl acetate (10.93%), and carbitol (13.05%) bioactive compounds, respectively. The obtained results from the in vitro study revealed that most of the essential oils exhibited antimicrobial properties. Among the tested essential oils, tea tree was discovered to demonstrate the strongest antimicrobial activity. The recorded MIC of S. Typhi was 6.2 mg/mL, 3.4 mg/mL of C. koseri, 3.1 mg/mL of E. coli, and 2.7 mg/mL of E. coli ATCC 25922, compared to M. alternifolia. Similarly, only S. aureus ATCC 25923 showed antimicrobial activity towards R. officinalis (1.4 mg/mL), E. oblique (2.9 mg/mL), and L. angustifolia (2.1 mg/mL). Based on the obtained results, it is possible to conclude that tea tree essential oil might be used as an ecological antimicrobial in treating infectious diseases caused by the tested pathogens

Vanadijum u ishrani živine

Vanadium (V) is essential element for poultry nutrition. Relatively low level of V ( lt 10 μg/kg of feed) is known to reduce both growth in chicks and Haugh unit value of eggs. The National Research Council (NRC) recommends the presence of very low levels of V in poultry diets, with the maximum tolerance level (MTL) being 10 mg/kg. Excessive vanadium in poultry diets has been shown to be detrimental to egg production, interior quality of eggs (albumen height), body weight and feed consumption. There is little information on the content of V in feedstuffs. Phosphates are known to be the cause of excessive V in various types of poultry diets. The objective of this study was to obtain information about the content of vanadium in phosphates and poultry feed. The samples were prepared by microwave wet digestion. Content of V was determined by the method of coupled plasma with mass spectrometry on the Agilent ICP-MS 7700. The concentrations of vanadium determined in the examined samples were above the minimum recommended levels for poultry feed, still not exceeding the maximum tolerable values.Vanadijum (V) je esencijalni element u ishrani živine. Relativno niski nivoi V ( lt 10 mg) smanjuju porast pilića i vrednosti Haugh-ovih jedinica jaja. The National Research Council (NRC) preporučuje veoma niske nivoe V u hrani za živinu, pri čemu je za maksimalni nivo tolerancije utvrđena vrednost od 10 mg/kg. Višak vanadijuma u ishrani živine ispoljava štetne efekte u proizvodnji jaja, negativno utiče na unutrašnji kvalitet jaja, telesnu masu živine i efikasnost iskorišćavanja hrane. Podaci o sadržaju V u hrani i hranivima za životinje su oskudni, ali zna se da fosfatna mineralna hraniva često sadrže visoke koncentracije ovog elementa. Cilj ovog istraživanja je bio da se dobiju informacije o sadržaju vanadijuma u hranivima i hrani za živinu. Uzorci hrane za životinje su pripremljeni mikrotalasnom digestijom, a sadržaj V je određen metodom indukovano kuplovane plazme sa masenom spektrometrijom (ICP-MS). Koncentracije vanadijuma u ispitivanim uzorcima bile su iznad minimalnih preporučenih nivoa u ishrani živine, ali nisu prelazile maksimalne tolerantne vrednosti za živinu za ovaj element

Antimicrobial efficiency of medicinal plants and their influence on cheeses quality

Mlijeko i mliječni proizvodi najstarija su i najčešće konzumirana hrana širom svijeta. Ističu se kao izvor visokokvalitetnih proteina i najvažniji izvor bioaktivnih peptida. Mliječni proteini imaju visoku nutritivnu vrijednost i izvanredna ljekovita svojstva. Poznati su kao potencijalni sastojci funkcionalne hrane koja promiče zdravlje, a mliječna industrija već je komercijalizirala mnoge mliječne proteine i proizvode na bazi peptida koji se mogu konzumirati kao dio redovite dnevne prehrane. Osim toga, sir je vrlo osjetljiv na kontaminaciju patogenim i mikroorganizmima kvarenja, što rezultira smanjenjem njegovog roka trajanja i uzrokuje ozbiljne rizike za zdravlje potrošača. Danas se prehrambena industrija sve više specijalizira, a metode obrade se stalno razvijaju kako bi zadovoljile potrebe i zahtjeve potrošača. Potrošači zahtijevaju proizvode koji su sigurni i po mogućnosti bez sintetskih aditiva, što je dovelo do potrebe za traženjem prirodnih alternativa. Ljekovito bilje i njihovi ekstrakti zanimljiva su prirodna alternativa za očuvanje i poboljšanje kvalitete sira. Neke su tvari pokazale dobre učinke protiv većine uzročnika kontaminacije sira, kao što su Listeria monocytogenes, Staphylococcus aureus i Salmonella spp. Ipak, nije sasvim jasno utječe li dodavanje ljekovitog bilja na promjene karakteristika sira. Cilj ovog rada bio je prikazati učinak dodanog ljekovitog bilja, začina i eteričnih ulja na sireve u funkciji zaštite i kvarenja uzrokovanog patogenima i mikroorganizmima, kao i njihovog utjecaja na kvalitetu sira.Milk and dairy products are the oldest and most widely consumed nutritious foods worldwide. They are highlighted as a source of high-quality proteins and the most important sources of bioactive peptides. Milk proteins have high nutritive value and remarkable medicinal properties. They are known as potential health-promoting ingredients of functional foods, and the dairy industry has already commercialized many milk proteins and peptide-based products which can be consumed as part of a regular daily diet. Besides, cheese is highly susceptible to contamination by pathogenic and spoilage microorganisms, which results in a decrease in its shelf life and cause serious risks to the consumers’ health. Nowadays, the food industry is continuously becoming more specialized towards meeting consumer needs and demands. Consumers demand safe products, which are also preferably free of synthetic additives. Therefrom to the need to search for natural additives has emerged. Botanicals and their extracts came to an interest as a natural alternative for cheese preservation and quality enhancer. Some substances have demonstrated good effects against most pathogens of cheese such as Listeria monocytogenes, Staphylococcus aureus, and Salmonella spp. Nevertheless, it is not quite clear do the botanical addition affect cheese quality characteristics. This review aims to present the effect of added botanicals such as medicinal plants, herbs, spices and essential oils to cheeses in the function of protection against pathogens and spoilage microorganisms, as well as for their influence on the cheese quality

Nоvе i prеtеćе virusnе bоlеsti ciprinidа

The intensive aquaculture remains the world's fastest growing sector producing food of animal origin. In fact, it is the only animal food-producing sector growing faster than the human population, and provides an acceptable supplement to and substitute for wild fish. A number of cyprinid diseases have emerged globally and their study has become increasingly important. The expansion of aquaculture, which has relied heavily on the movement of animals and farming species new to aquaculture, has been paralleled with disease emergence. In the last few years several emerging or re-emerging fish diseases have been detected in cyprinid fish populations in Serbia. In this paper, the authors overview the major viral threats for cyprinid fishes in Serbia.Nа svеtskоm nivоu, intеnzivnа аkvаkulturа је nајbržе rаstući sеktоr zа prоizvоdnju hrаnе živоtinjskоg pоrеklа. Štа višе, tо је јеdini sеktоr kојi rаstе bržе оd lјudskе pоpulаciје i оbеzbеđuје znаčајnu dоpunu i zаmеnu izlоvlјаvаnju ribа iz оtvоrеnih vоdа. Nа žаlоst оvај trеnd је prаćеn pојаvоm brојnih bоlеsti ciprinidа nа glоbаlnоm nivоu. Еkspаnziја аkvаkulturе, kоја sе u vеlikој mеri оslаnjа nа trgоvinu i prоmеt ribа, uklјučuјući i vrstе kоје rаniје nisu kоrišćеnjе u аkvаkulturi је dоvеlа i dо istоvrеmеnоg širеnjа pаtоgеnа. U pоslеdnjih nеkоlikо gоdinа u pоpulаciјi ciprinidnih ribа u Srbiјi оtkrivеnо је nеkоlikо nоvih bоlеsti, а uоčеnа је i pоnоvnа pојаvа rаniје prisutnih bоlеsti. U оvоm rаdu аutоri prеzеntuјu nајznаčајniје nоvе i prеtеćе bоlеsti ciprinidа u Srbiјi

Bolesti jesetre u akvakulturi

Sturgeon aquaculture is economically important in many countries, for both meat and caviar production. Sturgeon is the common name for 27 species of fish belonging to the family Acipenseridae. Among them, only the sterlet (Acipenser ruthenus) and the Siberian sturgeon (Acipenser ba-erii) completes the lifecycle in fresh water. In Serbia, in the last few years, aquaculture enterprises have shown more interest in farming these fish species. Also, the importance of sturgeon aquaculture grows due to the rapid decrease of wild populations caused by overfishing, water pollution and destruction of habitat. The development of sturgeon aquaculture activities has been accompanied by the disease outbreaks, and possibility of the emergence and rapid dissemination of several infectious disease agents may represent serious problem in sturgeon aquaculture. Several viral, bacterial , fungal and parasitic diseases have been reported worldwide. Due to the limited knowledge about epizootiology and disease control methods, infectious diseases may represent a major challenge in sturgeon aquaculture. Moreover, none of the diseases reported in sturgeon are regulated in the World Organization for Animal Health (OIE) or European Union (EU) legislations. Due to the increasing interest in sturgeon aquaculture in Serbia present study is focused on the most important pathogens that may represent a threat to sturgeon aquaculture in Serbia.Akvakultura jesetre ima veliki ekonomski značaj u brojnim zemljama, kako za dobijanje mesa tako i za proizvodnju kavijara. Jesetra je uobičajeno ime za 27 vrsta riba koje pripadaju porodici Acipenseridae. Među njima, samo kečiga (Acipenser ruthenus) i sibirska jesetra (Acipenser baerii) pro-vode ceo životni ciklus u slatkoj vodi. Poslednjih godina, u Srbiji postoji veća zainteresovanost za uzgoj ovih vrsta riba. Značaj akvakulture jesetre raste zbog brzog opadanja njihovog broja u prirodi, izazvanog prekomernim izlivom, zagađenjem voda i uništavanjem staništa. Razvoj akvakulture jesetre je praćen pojavom bolesti, a mogućnost pojave i brzog širenja uzročnika zaraznih bolesti može predstavljati ozbiljan problem. Više virusnih, bakterijskih, gljivičnih i parazitskih bolesti je uočeno širom sveta. Zbog ograničenih podataka o epizootiologiji i metodama kontrole bolesti, zarazne bolesti mogu predstavljati veliki izazov u akvakulturi jesetri. Šta više, nijedna od bolesti utvrđenih kod jesetri nije regulisana od strane Svetske organizacije za zdravlje životinja (OIE) niti zakonodavstva Evropske unije (EU). Zbog sve većeg interesovanja za akvakulturu jesetre u Srbiji, u ovom radu je ukazano na najvažnije patogene koji mogu predstavljati pretnju za zapate jesetre u akvakulturi

Detection of glyphosate and its metabolite aminomethylphosphonic acid: Risk assessment for the aquatic organisms

This paper delves into a thorough risk assessment of glyphosate, a widely used herbicide, and its metabolite, aminomethylphosphonic acid (AMPA), within the aquatic ecosystems of the Danube-Tisa-Danube (DTD) network, which represents large land drained system between Serbia, Hungary, and Romania. The primary objective is to employ a Toxicity and Exposure Ratio (TER) framework, encompassing both acute and chronic considerations, to comprehensively evaluate the potential risks these agrochemicals pose to aquatic organisms in the intricate hydro system of the DTD. The study integrates field data, laboratory experiments, and mathematical modeling to quantify glyphosate and AMPA exposure levels in the DTD channels. Furthermore, it explores the toxicological impacts of these substances on a diverse range of aquatic organisms, such as fish, invertebrates, and amphibians, considering acute effects arising from short-term exposure and chronic effects resulting from prolonged interactions. This research aims to provide a holistic understanding of the risk landscape associated with glyphosate and AMPA in the DTD hydro system by employing the TER approach. The findings contribute valuable insights into the potential ecological implications of herbicide usage in this critical water network, aiding regulatory decision-making and facilitating the development of targeted mitigation strategies to safeguard aquatic biodiversity and ecosystem health

Management of blood lipid profile and oxidative status in Holstein and Simmental dairy cows during lactation

Upravljanje i određivanje lipidnog profila krvi i oksidacijskog statusa vrlo je korisno sredstvo za dokazivanje utjecaja stranih kemijskih tvari na proizvodnju mliječnih krava. Istraživanje različitih biomarkera oksidativnog stresa povezanog s različitim problemima u proizvodnji mliječnih krava predstavlja vrlo važno pitanje. Cilj ovog rada je istražiti različite biološke markere krava holstein i simentalske pasmine, tijekom različitih faza laktacije. Ukupno 60 krava holstein i simentalske pasmine podijeljeno je u dva tretmana (HF i S) koji su dalje podijeljeni u tri skupine. Skupine svake pasmine krava bile su podijeljene u tri faze u ranoj laktaciji od 32-75 dana (HF1 i S1), maksimalna laktacija 80-165 dana (HF2 i S2) i niska laktacija od 175 dana nadalje (HF3 i S3). Tijekom pokusa utvrđena je ukupna proizvodnja mlijeka i postotak mliječne masti i proteina. Uzorci krvi su uzeti iz jugularne vene svake krave, dok serum je sakupljen bez antikoagulanta i pohranjen na -20 °C u malim alikvotima do daljnje analize. Serum je zatim analiziran na trigliceride, kolesterol, HDL, LDL, AST, ALT, GGT, ukupni antioksidacijski status (TAS), ukupni oksidacijski status (TOS), MDA, SOD, katalaze i paraoksonaze (PON1). Značajno (P<0,05) su se pokazale visoke vrijednosti kolesterola, TOS-a i SOD-a na vrhuncu laktacije kod svih krava. Postupno opadanje od rane laktacije do niske laktacije uočeno je u vrijednostima triglicerida, ALT, dok je MDA postupno rasla iz iste faze u svih krava, dok su LDL i katalaza pokazale nepravilan raspon varijacija u različitim fazama laktacije među svim skupinama. Holstein pasmina pokazala je značajno više vrijednosti ALT i PON1 (level of signifikance), dok su vrijednosti HDL, TAS i TOS bile niže u simentalskoj skupini. Pokazujući znakove oksidativnog stresa, zaključeno je da metabolički napori krava tijekom vrha laktacije utječu na istražene parametre. Poremećaj u unosu hrane i porast metaboličkih procesa podižu oksidativni stres kod krava, osobito tijekom vrha laktacije koji se može odrediti nadziranjem promjena u krvi. Rezultati istraživanja pokazali su da je krave holštajn pasmine bila pod većim oksidativnim stresom u različitim fazama laktacije u odnosu na krave simentaske pasmine.Managing and determination of the blood lipid profile and oxidative status are useful tool to show the influence of foreign chemical substances on production of dairy cows. Investigation of various biomarkers of oxidative stress related to various problems in the production dairy cows presents a very important issue. The aim of this research was to investigate different biological markers in two different breeds of dairy cows – the Holstein Friesian and the Simmental, during different stages of lactation. The total of 60 Holstein Friesian and Simmental cows were divided into two treatments (HF and S) which was further divided into three groups each, respectively. Lactating groups of each cow breed was divided into three stages at early lactation of 32-75 days (HF1 and S1), peak lactation of 80-165 days (HF2 and S2) and low lactation of 175 days onward (HF3 and S3). During the research the total milk production and the percentage of milk fat and protein were determined. Blood samples were collected from jugular vein of each cow, the serum was harvested without anticoagulant and stored at -20 °C in small aliquots till further analysis. Serum was then analyzed for triglyceride, cholesterol, HDL, LDL, AST, ALT, GGT, the total antioxidant status (TAS), the total oxidant status (TOS), MDA, SOD, catalase and paraoxonase (PON1). Significantly (P<0.05) higher values of cholesterol, TOS and SOD at peak lactation stage was observed in all cows. A gradual decline from early lactation to low lactation was observed in the values of triglycerides and ALT, while MDA gradually increased from the same stage in all cows. The values of LDL and catalase showed an irregular pattern of variations in various lactation stages among all groups. The Holstein Friesian breed showed significantly higher values of ALT and PON1, while values of HDL, TAS and TOS were the lowest in Simmental group (P<0.05). By measuring the signs of oxidative stress, it was concluded that metabolic efforts of cows during the peak of lactation affected the investigated parameters. Disturbance in feed intake and rise in metabolic processes lift up oxidative stress in cows, especially during the peak of lactation, which might be determined by monitoring blood alterations. Results of our study indicated that the Holstein Friesian breed was under higher oxidative stress during different lactation stages compared to Simmental dairy cows

Occurrence and dietary exposure of organochlorine pesticides in common carp obtained from integrated production systems

The aim of this study was to determine the level of the organochlorine pesticides (OCPs) in meat, liver and skin of common carp. Fish were collected in spring and in autumn from fishpond that receives purified water from slaughterhouse. OCPs, including alpha-HCH, beta-HCH, delta-HCH, lindane, heptachlor, aldrin, heptachlor epoxide, trans-chlordane, cis-chlordane, endosulfan I, DDE, dieldrin, endrin, DDD, endosulfan II, dichlorodiphenyltrichloroethane (DDT), endosulfan sulphate, methoxychlor, and endrin ketone, were determined by using a gas chromatography-mass spectrometry method. OCPs were present at low concentrations and only aldrin was detected in all examined tissues. The estimated daily intake for OCPs via common carp from integrated system of production was at the lower level compared with the acceptable daily intake recommended by different organisations, showing no significant risk on consumers

Good sampling practice-prerequisite of a reliable examination of presence of Trichinella spp. in the wild boar meat

Дивље свиње могу бити резервоар инфекције Trichinellа spp. за домаће животиње, али и директан извор трихинелозе људи. У највећем броју држава Европе, трихинелоза се ретко јавља, док се на подручју некадашње Југославије (изузев Македоније и Словеније) јавља у виду спорадичних или масовних епидемија сваке године због чега се територије Србије, Босне и Херцеговине и Хрватске сматрају ендемским подручјем трихинелозе. Законом је прописан, у свим земљама региона, обавезан преглед меса дивљих животиња које су намењене за конзумирање. У нашој лабораторији се акредитованом методом „Микробиологија ланца хране – Откривање ларви Trichinella у месу методом вештачке дигестије“ (SRPS EN ISO 18743:2016) годишње прегледа преко 200 узорака меса дивљих свиња. Приликом пријема узорaка у лабораторију се дешавало да узорци буду неадекватни (≈ 10%), самим тим поуздан преглед меса на присуство Trichinella spp. није било могуће спровести. Како би се у што већој мери смањио број неадекватних узорака, наша лабораторија је издала „Упутство за узорковање, транспорт и складиштење узорака дивљих свиња за испитивање присуства ларви Trichinella spp. - метода вештачке дигестије“ које је достављено ловачким удружењима који достављају узорке меса дивљих свиња нашој лабораторији. Након тога, проценат неадекватних узорака се сваке године смањује, па је тако за 2018. годину он износио 3,14%, за 2019. годину 1,85%, за 2020. годину 0,42%. У 2021. години ниједан пристигао узорак у нашу лабораторију није био неадекватан.Wild boars could be a reservoir of Trichinella spp. for domestic animals, but also a direct source of human trichinelosis. In most European countries, trichinelosis is rare, while in the area of the former Yugoslavia (except Macedonia and Slovenia) it occurs in the form of sporadic or mass epidemics every year, which is why the territories of Serbia, Bosnia and Herzegovina and Croatia are considered endemic to trichinelosis. The law prescribes, in all countries of the region, a mandatory inspection of the meat of wild animals that are intended for consumption. In our laboratory, over 200 samples of wild boar meat are examined annually with the accredited method "Microbiology of the food chain - Detection of Trichinella larvae in meat by artificial digestion" (SRPS EN ISO 18743: 2016). When receiving samples in the laboratory, it happened that the samples were inadequate (≈ 10%), thus a reliable finding for the presence of Trichinella spp. was not possible. In order to reduce the number of inadequate samples as much as possible, our laboratory has issued "Instruction for sampling, transport and storage of wild boar samples for testing the presence of Trichinella spp. - method of artificial digestion” which was delivered to hunting societies which deliver samples of wild boar meat to our laboratory. After that, the percentage of inadequate samples decreases every year, so in 2018 it was 3.14%, in 2019 1.85%, in 2020 0.42%. In 2021, not a single sample arrived at our laboratory was inadequate.Zbornik kratkih sadržaj