ZOONOSIS OF AQUATICAL ORGANISMS

Organizmi koji žive u vodi imaju veliku važnost u prehrani ljudi. Istodobno su i realna opasnost za zdravlje ljudi, jer uzrokuju bolesti. Paraziti, bakterije i virusi mogu se direktno ili indirektno prenijeti s riba, školjkaša i s rakova na ljude. Pri nastanku bolesti važan utjecaj imaju pogodovni čimbenici, ponajprije umanjena imunoreaktivnost organizma te način i higijena prehrane. Češćoj pojavi bolesti pridonosi sve razvijeniji transport robe i ljudi, kao i prilagodba uzročnika na tehnološke promjene u pripremi hrane. Najčešće su parazitarne bolesti jer za mnoge parazite čovjek je jedna od karika u njihovu razvojnom ciklusu. Učestalost parazitarnih bolesti povećava i konzumiranje prijesnih riba i školjkaša. Osnovna značajka bakterijskih bolesti jest fakultativna patogenost većine uzročnika. Pojava bolesti u većini je slučajeva uvjetovana oslabljenom imunoreaktivnošću organizma. Nekoliko je bakterija, me|utim, izrazito patogeno i mogu prouzročiti znatan pobol i smrtnost u ljudi. Do danas nije opisan slučaj infekcije ljudi virusima specifičnim za organizme koji žive u vodenoj sredini. Ljudi se inficiraju humanim vrstama, a ribe, rakovi i školjkaši služe samo kao prijenosno sredstvo. Veliku važnost u tom pogledu imaju školjkaši. Ribe, a pogotovo školjkaši mogu biti izvor otrovanja u ljudi. Uglavnom su posrijedi toksini fitoplanktonskog podrijetla koji se kumuliraju u školjkašima i u ribama.Aquatic organisms play a very important role in human nutrition. They also pose a real threat for human health by causing various diseases. Parasites, bacteria and viruses may either directly or indirectly be carried from aquatic organisms to humans. Disease outbreaks are influenced by many factors among which decreased immune response and feeding habits and higyene are most important. More frequent occuence of foodborne diseases has a number of reasons, including international travel and trade, microbial adaptation and changes in the food production system. Parasitic diseases occur most frequently as a result of human role in parasites life cycles. The prevalence is further increased by consuming raw fish and shellfish. The main feature of bacterial infections is facultative pathogenicity of most ethiological agents. In most cases disease occures as a result of decreased immunoreactivity. Several bacteria are, however, hightly pathogenic and capable of causing high morbidity and mortality in human. To date it has not been reported the case of human infection with viruses specific for aquatic organisms. Human infections are caused with human viruses and aquatic organisms play role only as vechicles. The greatest risk in that respect present shellfish. Fish and particularly shellfish are likely to cause food poisoning in humans. In most cases the cause are toxins of phithoplancton origins accumulating in shellfish and fish

ZOONOSIS OF AQUATICAL ORGANISMS

Organizmi koji žive u vodi imaju veliku važnost u prehrani ljudi. Istodobno su i realna opasnost za zdravlje ljudi, jer uzrokuju bolesti. Paraziti, bakterije i virusi mogu se direktno ili indirektno prenijeti s riba, školjkaša i s rakova na ljude. Pri nastanku bolesti važan utjecaj imaju pogodovni čimbenici, ponajprije umanjena imunoreaktivnost organizma te način i higijena prehrane. Češćoj pojavi bolesti pridonosi sve razvijeniji transport robe i ljudi, kao i prilagodba uzročnika na tehnološke promjene u pripremi hrane. Najčešće su parazitarne bolesti jer za mnoge parazite čovjek je jedna od karika u njihovu razvojnom ciklusu. Učestalost parazitarnih bolesti povećava i konzumiranje prijesnih riba i školjkaša. Osnovna značajka bakterijskih bolesti jest fakultativna patogenost većine uzročnika. Pojava bolesti u većini je slučajeva uvjetovana oslabljenom imunoreaktivnošću organizma. Nekoliko je bakterija, me|utim, izrazito patogeno i mogu prouzročiti znatan pobol i smrtnost u ljudi. Do danas nije opisan slučaj infekcije ljudi virusima specifičnim za organizme koji žive u vodenoj sredini. Ljudi se inficiraju humanim vrstama, a ribe, rakovi i školjkaši služe samo kao prijenosno sredstvo. Veliku važnost u tom pogledu imaju školjkaši. Ribe, a pogotovo školjkaši mogu biti izvor otrovanja u ljudi. Uglavnom su posrijedi toksini fitoplanktonskog podrijetla koji se kumuliraju u školjkašima i u ribama.Aquatic organisms play a very important role in human nutrition. They also pose a real threat for human health by causing various diseases. Parasites, bacteria and viruses may either directly or indirectly be carried from aquatic organisms to humans. Disease outbreaks are influenced by many factors among which decreased immune response and feeding habits and higyene are most important. More frequent occuence of foodborne diseases has a number of reasons, including international travel and trade, microbial adaptation and changes in the food production system. Parasitic diseases occur most frequently as a result of human role in parasites life cycles. The prevalence is further increased by consuming raw fish and shellfish. The main feature of bacterial infections is facultative pathogenicity of most ethiological agents. In most cases disease occures as a result of decreased immunoreactivity. Several bacteria are, however, hightly pathogenic and capable of causing high morbidity and mortality in human. To date it has not been reported the case of human infection with viruses specific for aquatic organisms. Human infections are caused with human viruses and aquatic organisms play role only as vechicles. The greatest risk in that respect present shellfish. Fish and particularly shellfish are likely to cause food poisoning in humans. In most cases the cause are toxins of phithoplancton origins accumulating in shellfish and fish

COMPARISON OF THE HISTOLOGICAL CHANGES IN ORGANS OF CHUB (Squalius cephalus) WITH THE NUMBER OF BACTERIA IN THE WATER OF SAVA RIVER

Za naše istraživanje uzorkovano je ukupno 157 klenova na 5 postaja od slovensko–hrvatske granice do utoka rijeke Une u Savu. Dvije postaje bile su uzvodno, a preostale tri nizvodno od grada Zagreba i glavnih izvora onečišćenja vode. Jetra, slezenu, bubreg, škrge i crijevo uzorkovali smo kod svih klenova i izradili histološke preparate koje smo obojili hematoksilin eozinom. Istodobno je uzorkovana voda i određen broj heterotrofnih i koliformnih bakterija. Na osnovi rezultata ovog rada možemo zaključiti da bi histološke promjene u organima klena mogle poslužiti kao pokazatelj onečišćenja vode. Razlike intenziteta histoloških promjena bile su sukladne razlici u broju heterotrofnih i koliformnih bakterija na pojedinim postajama. Histološke promjene, kao rezultat kumulativnoga djelovanja, vjernije su nego broj heterotrofnih i koliformnih bakterija odražavale kakvoću vode. U svim organima utvrđen je barem jedan histološki pokazatelj s visokom pozitivnom korelacijom sa stupnjem onečišćenja vode. Škrge su bile organ s najbrojnijim histološkim pokazateljima koji su bili u korelaciji s promjenom kakvoće vode.In this study we sampled 157 chubs on 5 sites from slovenian–croatian border through to the inflow of river Una in Sava. Two sites were upstream while the remaining were downstream from the city of Zagreb. Gills, intestine, spleen, kidney and liver were sampled from all fish. Histological slides were stained with haematoxylin and eosin and examined under the light microscope. At the same time, water was sampled for the counting of coliforms and heterotrophic bacteria. According to the results of this study we can conclude that fish histology is a valuable indicator of water pollution. The intensity of histological parameters was in correlation with the number of bacteria in water. Furthermore, fish histology proved to be more reliable method than water microbiology as differences between two sampling seasons were not significant for histological indices while being significant for bacteria counts. At least one histological parameter highly correlated with water quality was found in every organ. Of the organs examined, response in the gills correlated best with changes in water quality