Praćenje promene broja bakterija familije enterobacteriaceae u pastrmci i odrescima šarana upakovanim u vakuum i modifikovanu atmosferu

Kvar ribe može se definisati kao bilo koja promena u mesu ribe koja proizvod čini neprihvatljivim za ljudsku ishranu i najčešće nastaje kao rezultat rasta mikroorganizama. Od toga koji su mikroorganizmi najzastupljeniji u ribi u trenutku ulova u velikoj meri zavisi i kolika će biti njena održivost tokom skladištenja. Bakterije koje pripadaju familiji Enterobacteriaceae su fakultativni anaerobi, gram negativni i katalaza pozitivni mikroorganizmi. Ovoj familiji pripadaju sledeći rodovi: Salmonelle, Escherichia, Proteus, Shigella, Serratia, Citrobacter, Klebsiella, Enterobacter i Erwinia, a neki od njih su izraziti patogeni i izazivači velikog broja različitih oboljenja kod ljudi, kao što su septikemija, pneumonija, meningitis, infekcije urinarnog trakta, bolesti organa za varenje i mnogih drugih bolesti. Široko su rasprostranjeni u spoljašnjoj sredini, a neki su saprofitski stanovnici digestivnog trakta. Cilj ovog eksperimenta je bio da se ispita rast bakterija familije Enterobacteriaceae u svežoj pastrmci i odrescima šarana upakovanim u vakuum i modifikovanu atmosferu. Uzorci su podeljeni u tri grupe. Grupa I je upakovana u modifikovanu atmosferu sa odnosom gasova 60%CO2 i 40%N2, grupa II je upakovana u modifikovanu atmosferu sa 40%CO2 i 60%N2 dok je III grupa upakovana u vakuum. Odnos gas/uzorak u pakovanju bio je 2:1. Svi uzorci su skladišteni pri istovetnim uslovima na temperaturi od +3˚C. Određivanje broja bakterija familije Enterobacteriaceae prema ISO 21528 -2:2004 obavljeno je 0, 7. i 14. dana skladištenja. U pastrmci i odrescima šarana upakovanim u modifikovanu atmosferu sa 60%CO2 i 40% N2 (I grupa), rast ukupnog broja enterobakterija bio je sporiji nego u pastrmci i odrescima šarana upakovanim u modifikovanu atmosferu sa 40%CO2 i 60%N2 (II grupa) ili pak u vakuum (III grupa). Ovo se može objasniti antimikrobnim dejstvom ugljen-dioksida, koji je procentualno najzastupljeniji u smeši gasova u koju su upakovani uzorci I grupe kao i činjenicom da ugljen-dioksid deluje inhibitorno pre svega na gram-negativne bakterije, kakvi i jesu mikroorganizmi iz familije Enterobacteriaceae. Najveću stopu rasta imale su enterobakterije u pastrmci i odrescima šarana III grupe tj. u uzorcima upakovanim u vakuum. Ovi rezultati ukazuju na sposobnost Enterobacteriaceae da rastu u anaerobnim uslovima, na temperaturi frižidera u proizvodima upakovanim u vakuum. Modifikovana atmosfera smanjuje ukupan broj enterobakterija, a najniža vrednost je dobijena kod odrezaka šarana upakovanih u modifikovanu atmosferu sa 60%CO2 i 40%N2

Mikrobiološki aspekti ekološkog statusa šaranskog ribnjaka tokom trogodišnjeg perioda

Šaranski ribnjaci su, pored pastrmskih ribnjaka jedan od dva najzastupljenija vida akvakulture na našim prostorima. Konzumni šaran može da dostigne dužinu od preko 30 cm i masu preko 6 kg. Meso šarana bogato je polinezasićenim masnim kiselinama koje imaju korisno delovanje u ishrani. Šaran iz akvakulture, dobro je prilagođen na uslove životne sredine, koji su slični onima u prirodnom staništu. Naseljava bentos i pelagijal, rastresiti mulj i vegetaciju širokih, usporenih vodotokova. Šaran je omnivor i hrani se rečnim rakovima, insektima, crvima, larvama i submerznim biljkama. Pored makroozooplanktna i makrozoobentosa, mikroskopski vidljive alge, bakterije, gljive i virusi prisutne su u ekosistemu šaranskih ribnjaka. Bakterije mogu biti korisne, bezopasne, štetne ili patogene. E. coli i Enterobacteriaceae važni su pokazatelji fekalnog zagađenja vode i rizika po zdravlje gajenih životinja. Zdrave jedinke šarana u svom crevnom sistemu imaju korisne bakterije, saprofite, koje u uslovima optimalnog metabolizma, postaju dominantne. Saprofitnu mikrofloru crevnog sistema šarana čine, sa više od 99 % Bacillus spp., Bifidobacterium spp., Lactobacillus spp., Saccharomycetes, itd. Aerobne i fakultativno aerobne bakterije čine oko 1 % crevne mikroflore. Različite su bakterije koje izazivaju oboljenja gajene ribe. Aeromonas spp. su Gram- negativne bakterije koje naseljavaju prirodno stanište slatkovodnih i morskih ekosistema a i deo su oportunističke saprofitne mikroflore gastrointestinalnog trakta. Aeromonas spp. vrlo je čest izolat iz hemoragičnih lezija i nekrotičnih delova tkiva. Kod šarana, Aeromonas salmonicida dovodi do oboljenja, poznatijeg kao eritrodermatitis. Septikemije kod šarana mogu izazvati pokretljive aeromonade, A. hydrophila, A. sobria i A.caviae. U slučaju oboljenja šarana, gde je veoma velika gustina populacije ribe u ribnjaku, lako dolazi do širenja bolesti, a sama bolest teško se iskorenjuje, uz velike ekonomske gubitke. Enterobakterije obuhvataju rodove Escherichia, Salmonella, Klebsiella, Edwardsiella i Yersinia. Ukupno je ispitivano po 6 uzoraka ribe (koža i mišić), hrane za ribe, mulja i vode, tokom 4 godišnja doba, tokom trogodišnjeg perioda. Uzorci kože i mišića šarana ispitivani su prema metodama propisanim u Pravilniku o metodama vršenja mikrobioloških analiza i superanaliza životnih namirnica (Sl. list SFRJ br.25/80). Na ovaj način uzorci su ispitani na prisustvo Salmonella spp., Proteus spp., E.coli, Clostridium spp. i Staphylococcus aureus. Odgovarajućim ISO i ostalim mikrobiološkim metodama utvrđivano je prisustvo Aeromonas hydrophila, Vibrio parachaemoliticus., Yersinia enterocolitica., P. aeruginosa, odnosno E. coli, koliformnih bakterija i intestinalnih enterokoka. Ukupan broj bakterija izolovanih iz kože i mišića kretao se od 3.11 log10 CFU/g do 4.72 log10 CFU/g. E.coli izolovana je iz barem jednog uzorka kože od šest ispitivanih, tokom svih uzorkovanja. Ostali patogeni mikroorganizmi nisu izolovani iz tkiva. Ukupan broj koliformnih bakterija u vodi nije prelazio 198 bakterija/100 ml, dok su u mulju nađeni predstavnici rodova Aeromonas i Clostridium, pored E.coli. Hrana za ribe bila je mikrobiološki ispravna po kriterijumima važećeg Pravilnika. Na osnovu ovih pokazatelja može se zaključiti da je proizvodnja šarana u veštačkom sistemu akvakulture omogućila dobijanje mikrobiološki ispravnog mesa iz ujednačenog ekosistema najsličnijeg prirodnom staništu rečnog šarana C. carpio

CLIMATE CHANGE: IMPACT ON MYCOTOXINS INCIDENCE AND FOOD SAFETY

Climate change may have an impact on the occurrence of food safety hazards along the entire agri-food chain, from farm to fork. The interactions between environmental factors and food contamination, food safety and foodborne diseases are very complex, dynamic and difficult to predict. Extreme weather conditions such as floods and droughts which have not occurred previously in Serbia, may be supporting factors to contamination of crops by various species of toxigenic fungi and related mycotoxins. Mycotoxins are a group of naturally occurring toxic chemical substances, produced mainly by microscopic filamentous fungal species that commonly grow on a number of crops and that cause adverse health effects when consumed by humans and animals. Recent drought and then flooding confirmed that Serbia is one of the few European countries with very high risk exposure to natural hazards, as well as that mycotoxins are one of the foodborne hazards most susceptible to climate change.Climate change may have an impact on the occurrence of food safety hazards along the entire agri-food chain, from farm to fork. The interactions between environmental factors and food contamination, food safety and foodborne diseases are very complex, dynamic and difficult to predict. Extreme weather conditions such as floods and droughts which have not occurred previously in Serbia, may be supporting factors to contamination of crops by various species of toxigenic fungi and related mycotoxins. Mycotoxins are a group of naturally occurring toxic chemical substances, produced mainly by microscopic filamentous fungal species that commonly grow on a number of crops and that cause adverse health effects when consumed by humans and animals. Recent drought and then flooding confirmed that Serbia is one of the few European countries with very high risk exposure to natural hazards, as well as that mycotoxins are one of the foodborne hazards most susceptible to climate change

Evaluation of pig welfare in lairage and process hygiene in a single abattoir

Food safety is indirectly affected by the welfare of food animals, due to close links between animal welfare, animal health and food borne diseases. Stress factors and poor welfare can lead to increased susceptibility to disease among animals and may intensify the fecal shedding of food borne pathogens, e.g. Salmonella, Campylobacter, Yersinia, and human pathogenic STEC in the pre-slaughter phase: on-farm, in transport and in lairage. This study evaluated two aspects: a) assessment of pig welfare in abattoir lairage founded on animal-based categories, and b) the relationship between pig welfare and microbial process hygiene at slaughter. The results revealed that the animal-based category ‘manure on the body’ assessed in abattoir lairage corresponded with microbial process hygiene at slaughter

A hygiene report regarding slaughter process of pig and cattle carcasses for 2017 in Serbia

For the successful validation and verification of the HACCP system, a food business operator is obliged, among other duties, to have continuous microbiological data of carcasses which are followed by a certain dynamic that the subject himself prescribed. To obtain these data, it is necessary to perform systematic monitoring of indicator microorganisms. The most important meat hygiene indicators are Total Viable Counts (TVC) and Enterobacteriaceae (EC). TVC are defined as indicators of overall slaughter hygiene (equipment, environment, tools, workers), while EC are indicators of faecal contamination on carcasses. The aim of this study was to determine the microbial contamination of cattle and pig carcasses, level of hygiene of the slaughter process as well as whether variations hygiene levels were related to seasonality in Serbia during 2017. The year was divided into four quarters of three months each, while the microbiological results were classified into three levels of hygiene status (unsatisfactory, satisfactory or acceptable). The highest percentage of the results surveyed during the entire study was at a satisfactory hygiene level. Furthermore, we found there were differences in results between the quarters, which could be associated with seasonality. The best microbiological results, and so the best hygiene of carcasses, was recorded in the period April, May, June, while the worst microbiological results were observed in the period of July, August and September

Wholegenome sequencing as the gold standard approach for control of Listeria monocytogenes in the food chain

Listeria monocytogenes has been implicated in numerous outbreaks and related deaths of listeriosis. In food production, L. monocytogenes occurs in raw food material and above all, through postprocessing contamination. The use of next-generation sequencing technologies such as whole-genome sequencing (WGS) facilitates foodborne outbreak investigations, pathogen source tracking and tracing geographic distributions of different clonal complexes, routine microbiological/epidemiological surveillance of listeriosis, and quantitative microbial risk assessment. WGS can also be used to predict various genetic traits related to virulence, stress, or antimicrobial resistance, which can be of great benefit for improving food safety management as well as public health

Landscape of Stress Response and Virulence Genes Among Listeria monocytogenes Strains

The pathogenic microorganism Listeria monocytogenes is ubiquitous and responsible for listeriosis, a disease with a high mortality rate in susceptible people. It can persist in different habitats, including the farm environment, the food production environments, and in foods. This pathogen can grow under challenging conditions, such as low pH, low temperatures, and high salt concentrations. However, L. monocytogenes has a high degree of strain divergence regarding virulence potential, environmental adaption, and stress response. This review seeks to provide the reader with an up-to-date overview of clonal and serotype-specific differences among L. monocytogenes strains. Emphasis on the genes and genomic islands responsible for virulence and resistance to environmental stresses is given to explain the complex adaptation among L. monocytogenes strains. Moreover, we highlight the use of advanced diagnostic technologies, such as whole-genome sequencing, to fine-tune quantitative microbiological risk assessment for better control of listeriosis

CLIMATE CHANGE: IMPACT ON MYCOTOXINS INCIDENCE AND FOOD SAFETY

Climate change may have an impact on the occurrence of food safety hazards along the entire agri-food chain, from farm to fork. The interactions between environmental factors and food contamination, food safety and foodborne diseases are very complex, dynamic and difficult to predict. Extreme weather conditions such as floods and droughts which have not occurred previously in Serbia, may be supporting factors to contamination of crops by various species of toxigenic fungi and related mycotoxins. Mycotoxins are a group of naturally occurring toxic chemical substances, produced mainly by microscopic filamentous fungal species that commonly grow on a number of crops and that cause adverse health effects when consumed by humans and animals. Recent drought and then flooding confirmed that Serbia is one of the few European countries with very high risk exposure to natural hazards, as well as that mycotoxins are one of the foodborne hazards most susceptible to climate change

Reducing Sodium Chloride Content in Meat Burgers by Adding Potassium Chloride and Onion

AbstractThe goal of this paper was to examine the reduction of sodium chloride by partial replacing with potassium chloride and the influence on taste acceptability of meat burgers. Sodium chloride content in burgers produced with 1.5% of salt and half of partial replacement of sodium chloride with potassium chloride in burgers was 0.62-0.67% in fresh and 0.72-0.93% in grilled burgers. The best taste acceptability had burgers with 1.5% of added sodium chloride and burgers with 1.5% salt and 50g of added onion, in which the partial replacement of sodium chloride with potassium chloride was one half