Az előadás letöltése folymat van. Kérjük, várjon

Az előadás letöltése folymat van. Kérjük, várjon

Mikrobiológiai veszélyek

Hasonló előadás

Az előadások a következő témára: "Mikrobiológiai veszélyek"— Előadás másolata:

1 Mikrobiológiai veszélyek
Modul 02 - lecke 01 Mikrobiológiai veszélyek This lecture covers some of the basic knowledge necessary to apply HACCP. It is not the intention to give a short course in microbiology. Whenever insufficient knowledge concerning microbiological hazards is available in applying HACCP, outside expertise should be sought. If additional information is needed, see the enclosed list of further reading material.

2 A mikroorganizmusok nagyon kicsik
Joghurt 1 pohár joghurt 22x ennyit tartalmaz! pl különböző élő mikroorganizmus. A világ népessége 5.5 BILLION pl Microorganisms are extremely small. This slide tries to put this statement into perspective by showing you the astounding number of harmless lactic acid bacteria in a cup of yoghurt. (When explaining this concept, try to find an example which is meaningful to your listeners).

3 Mikroorganizmusok osztályozása
jelentőségük alapján Patogén mikróbák Romlást okozó mikróbák Hasznos mikroorganizmusok We have seen that microorganisms can be dangerous. As already mentioned, some organisms are not dangerous but may spoil foods. Some microorganisms are used to ferment food and drinks.

4 Veszélyes mikroorganizmusok
Élelmiszer eredetű megbetegedések Baktériumok Penészek Vírusok Paraziták Microorganisms consist of four main groups of varying complexity. Bacteria and moulds are most familiar to us since we can either see them, (e.g. mouldy fruit), or we can see the effects of their activities (e.g. spoiled meat). Viruses and parasites are less evident but, as with bacteria, we are aware of their effects when we suffer from an infection.

5 A legfontosabb, élelmiszer eredetű megbetegedést okozó baktériumok
Aeromonas spp. Bacillus cereus Brucella spp. Campylobacter jejuni Clostridium botulinum Clostridium perfringens Escherichia coli Listeria monocytogenes Mycobacterium bovis Salmonella spp. Shigella spp. Staphylococcus aureus Vibrio cholerae Vibrio parahaemolyticus Vibrio vulnificus Yersinia enterocolitica Many bacteria cause foodborne diseases. This list gives you an idea of the variety of organisms which can be transmitted through food. Later, we will discuss the differences between them, where they come from, and how they get into foods.

6 Romlást okozó mikroorganizmusok
Baktériumok Élesztők Penészek The main spoilage organisms are bacteria, yeasts and moulds. They may cause food to deteriorate, producing undesirable changes in flavour, odour or taste. Sometimes, these changes may be seen as desirable. In some cheeses, moulds are essential to the production process. However, we would not consider bread or fruit with the same mould growing on the surface to be fit to eat.

7 Élelmiszer-gyártás hasznos mikroorganizmusok felhasználásával
Fermentált húskészítmények Joghurt Sajt Sör Kovásszal készült kenyér Szójaszósz Tofu Many microorganisms are useful to us. Fermented products exist all over the world. Here are some examples.

8 Hasznos mikroorganizmusok
Tejsavbaktériumok (LAB) A szénhidrátokat szerves savakra bontják, melyek gátolják Salmonella-t Staphylococcus-t Listeria-t Clostridium-ot E. coli-t Lactic acid bacteria are very common in the natural world and are probably some of the first organisms to grow as plant matter decays. Many natural traditional fermentations contain these organisms. These organisms produce not only lactic acid but other organic acids as by-products of carbohydrate breakdown. They are found in soil, on plants and are natural inhabitants of the human gut. The organic acids reduce the pH of the surroundings (we shall look at pH later). This inhibits the growth of many microorganisms and may help lactic acid bacteria compete in their environment. Organic acids also inhibit many pathogens. Some traditional fermentations were used by ancient peoples to preserve food. Many of these methods are still used today. LAB található növényekben talajban állatokban emberi béltraktusban

9 A legfontosabb, élelmiszer-eredetű megbetegedést okozó vírusok
Hepatitis A és E vírusok Kis, kerek struktúrájú vírusok (pl. Norwalk) Rotavírus Poliovírus Viruses, unlike bacteria, cannot be cultivated outside a living host. They are much smaller and can be seen only with an electron microscope. Here is a list of viruses associated with foodborne disease. There are no animal or plantborne viruses causing food-transmitted illness. All foodborne viruses originate from the human gut, and use it as their target. Any food vehicle contaminated with human faeces could be contaminated with these viruses. Shellfish harvested in polluted water are common causes of foodborne viral infections all over the world.

10 Néhány, élelmiszer-eredetű megbetegedést okozó toxikus penész
Aspergillus spp. Fusarium spp. Penicillium spp. ( Fő forrás – gyümölcsök, diófélék és gabonamagvak ) Some products of the metabolic activity of moulds (i.e. mycotoxins) may also cause foodborne intoxications. The three genera most often associated with toxin production are listed here. Acute intoxication by mycotoxins seems to be rare, but the result of chronic exposure is of considerable concern. Moulds are found in the environment, often on fruits, nuts and grains where they grow under the right conditions of temperature and humidity. In general, moulds are more likely to cause food spoilage than to produce toxins.

11 A legfontosabb, élelmiszer-eredetű megbetegedést okozó paraziták
Anisakis Ascaris Clonorchis sinensis Cryptosporidium Cyclospora cayetanensis Diphyllobothrium Echinococcus Entamoeba histolytica Fasciola hepatica Giardia Opisthorchis felineus Opisthorchis viverrini Sarcosporidium Taenia Toxoplasma Trichinella Parasites can include bacteria and viruses, but in general, this term is applied to protozoal and helminthic organisms. These parasites sometimes have complicated life cycles in which the human host is only one stage. To make the proper interventions to prevent transmission to humans, it is important to understand these life cycles.

12 Baktériumok növekedési görbéje
toxintermelés + _ Romlásig eltelt idő Idő 1 2 3 4 5 6 7 8 9 Lag fázis Log fázis Stationer fázis Romlás Log baktériumszám This graph shows the increase of bacteria with time, and its relation to spoilage and toxin production. At first, bacteria adapt to their surroundings and do not divide; this is the lag phase of growth. The next period is called the logarithmic growth phase, because the numbers increase exponentially (we have used a logarithmic scale on the Y axis, so this phase appears as a straight line). The time needed for the number of organisms to double is the generation time. After a while, the production of toxic by-products such as acids, and the depletion of growth substrates such as carbohydrate, essential amino acids, or oxygen, limit further growth. The curve flattens; this is the stationary phase. Toxins are produced towards the end of the logarithmic phase and during the stationary phase of the growth curve. Since toxin formation may occur before microbial growth produces visible changes, a seemingly acceptable food can cause an intoxication.

13 Fertőző, élelmiszer-eredetű baktériumok
Fertőzés a szervezeten belüli inváziója vagy megsokszorozódása Salmonella Campylobacter E. coli (bizonyos fajok) V. parahaemolyticus V. cholerae Y. enterocolitica A. hydrophila L. monocytogenes Several pathogens are able to invade the body and multiply in the tissues of the gut and other organs. The seriousness of the infection depends on the state of the patient. Young children, pregnant women, old people and people who are ill tend to be more severely affected than healthy adults. Young children are particularly likely to become sick, and the elderly have a high fatality rate.

14 Salmonellosis Fő tünetek Veszélyeztetettek Halálozási arány
hasmenés láz hasi görcsök hányás Veszélyeztetettek gyerekek idősek terhes nők legyengül immunrendszerű egyének betegek Halálozási arány < 1% Lappangási idő általában óra As we shall see later, salmonellosis is one of the most common foodborne diseases (FBDs), particularly in industrialized countries. The symptoms are listed here. They are typical of many enteric disease symptoms. We can see that the categories of people most at risk are the ones we just mentioned. The mortality is low in the general population, although it can be higher if an outbreak occurs in a hospital or nursing home, or if proper rehydration is not available. The disease called “typhoid” is also caused by a Salmonella. However, typhoid is a generalized disease while the salmonellae discussed here usually cause gastroenteritis.

15 Salmonella 2200 különböző szerotípus
200 olyan, amely minden évben okoz élelmiszer-eredetű megbetegedést Európában Az esetek 70%-át S. enteritidis és S. typhimurium okozza A szerotípusok szubtípusokra oszlanak, amiket fág-típusoknak neveznek There are more than 2000 serotypes of Salmonella that can be identified in the laboratory. 200 of these have been associated with FBD in Europe. 70% of the cases are caused by two types: S. enteritidis and S. typhimurium. We can further distinguish between the serotypes by phage typing. This technique looks at the sensitivity to bacteriophage viruses that specifically attack the genus.

16 Nyers élelmiszerek, amik valószínűleg Salmonella-val fertőzöttek
Szárnyas Hús Tej Tojás Zöldségek Kagyló Fűszerek és gyógynövények Kezeletlen víz These organisms live in the gut of warm-blooded animals and birds. They can be isolated from the environment, where they are transmitted from faeces and where they can survive. Poultry and eggs are a major source of Salmonella, particularly S. enteritidis which infects chickens. Other meat is less likely to be associated with it. In Europe, milk tends to be associated with S. typhimurium. Contaminated irrigation water can transmit a variety of serotypes to vegetables. Shellfish can be contaminated by sewage discharged into the sea and rivers. Spices which are dried in the open air can be exposed to animals and birds.

17 A Salmonella hőtűrése élelmiszerekben
Salmonella hőre érzékeny A pasztörizálás elegendő az elpusztításához Salmonella magas nedvességtartalmú élelmiszerekben 70°C-os 2 perces hőkezelés elegendő a csíraszám 6 log csökkentéshez Even though the organisms may be found in raw materials, standard heat treatments, applied in the presence of sufficient moisture, usually will kill them. Some strains are particularly heat resistant. However, 70°C for 2 minutes is usually sufficient to reduce the number of Salmonella by a factor of 106.

18 Campylobacteriosis Fő tünetek Veszélyeztetettek
enyhe/komoly hasmenés láz émelygés hasi görcsök Veszélyeztetettek Csecsemők és gyerekek Legyengült emberek Lappangási idő ált. 2-5 nap In many countries, campylobacteriosis is rapidly overtaking salmonellosis as the most frequently reported cause of enteric disease. It is caused by a spiral organism commonly found in poultry and in other birds, which may be a normal gut inhabitant since it is found in free range poultry. Campylobacter coli, which infects pigs in some countries and poultry in others, can cause human illness.

19 A Campylobacter túlélése
Nagyon sérülékeny mikroba, az élelmiszer-feldolgozást többnyire nem éli túl Hőérzékeny Érzékeny a szárazságra Túléli a fagyasztást (fagyasztott húsban, baromfiban néhány hónap) Jobban tűri a hűtést, mint a környezeti hőmérsékletet These organisms are fragile. They survive only for seconds at 60°C. They are sensitive to drying although they may survive in frozen meat and poultry. They require special low oxygen conditions to grow and thus, do not normally grow in foods. Later, we shall look at the epidemiology of this disease.

20 Pathogén E. coli Enteropathogén E. coli ( EPEC )
Enteroinvasív E. coli ( EIEC ) Enterotoxikus E. coli ( ETEC ) Enterohaemorrhagiás E. coli ( EHEC ) E. coli is one of the organisms most familiar to bacteriologists. It is a normal inhabitant of the gut of warm-blooded animals, including man, and birds. Although we all have it in our gut, we may not readily accept E. coli from outside sources. The organism is obviously adapted to this niche, which also means that some strains may have characteristics that favour their colonization over other strains. This may be the reason that the organism can cause disease. Four types of disease have been recognized, each with different symptoms.

21 Pathogén E. coli EPEC Akut, vizes hasmenés – elsősorban a fiatal gyermekek fogékonyak EIEC Dizentéria-szerű tünetek ETEC Akut, vizes hasmenés – általában az utazók betegsége EHEC Véres, hasmenéses szindróma Lappangás: típustól függően 8-44 óra Diarrhoea due to this organism is probably one of the most common causes of morbidity in young children. The symptoms of the different types of disease vary in severity. When travellers adjust to the microflora of different countries, they often experience a mild form of diarrhoea. Lately, enterohaemorrhagic E. coli O157;H7 has emerged in the USA, Europe, Japan and Africa as the cause of not only a severe enteritis, but of subsequent kidney disease, which can be fatal and is particularly likely to affect children.

22 Pathogén E. coli az élelmiszer-eredetű megbetegedésekkel kapcsolatban
E. coli Reservoir Forrás Előfordulás típus EPEC ember élelm. feldolgozó - ritka szennyvíz - környezet EIEC ember élelm. feldolgozó - lágy sajt - víz szennyvíz ETEC ember élelm. feldolgozó - lágy sajt - víz szennyvíz EHEC lábasjószág állatok ürüléke - Nem kellően húsfeldolgozó hőkezelt hús berendezés (pl. hamburger) tejtermék pasztörizálatlan tej Some E. coli can be spread from person to person, especially EIEC. The food handler can spread it to food. It grows easily in the gut, so small numbers can cause disease. This table shows that EIEC, ETEC and EHEC have all been associated with foods. EPEC rarely causes food-related disease.

23 A baktériumok szaporodása
1 2 3 4 5 Bacteria divide asexually by binary fission. There are four or five points at which the cell gradually splits after first elongating. Bacteria can exchange genetic material in a process called conjugation, where simple circular strands of DNA called plasmids are passed from one to the other. Under optimum conditions, bacteria can duplicate every 20 minutes. These dividing bacteria are in the vegetative form. Some bacteria may exist also in a sporulated form. This is a survival mechanism. Sporulated bacteria are much more resistant to e.g. heating. They can not multiply however, in the sporulated form.

24 Fertőzési mennyiség Gazdaszervezet Életkor Immunállapot
Gyomornedv kémhatása Immunmegfelelés A bélflóra összetétele Terhesség We have mentioned infection and the numbers of microorganisms required to cause it. The infectious dose is determined by several factors. The state of the host is important; age and immune status are critical, and perhaps related. We know very little about the factors affecting immune status but certainly, malnutrition is one of them. Gastric acid is one of the first barriers to infection; its pH may change according to the food. The gut flora may also be important since they can help prevent the establishment of pathogens. Certain infections, such as listeriosis and toxoplasmosis, may be of concern to pregnant women, because of the high susceptibility of the unborn child.

25 Fertőzési mennyiség Organizmus Virulencia Vegetatív sejtek vagy spóra
The organism is also important, whether it is sporulated or in the vegetative state. Some strains have special characters such as fimbriae which help them to attach to the gut. These contribute to the virulence of the strain. However, the outcome of infection is related to the interaction of the state of the host and the organism.

26 Fertőzési mennyiség Élelmiszer Zsiradék jelenléte Savasság
The type of food can play a role. Fatty foods may form an insoluble layer of fat around the microorganism, thus protecting it from the bactericidal effects of gastric acid. In outbreaks of salmonellosis linked to chocolate and cheese, the number of organisms present was very low. The acidity of the stomach is a major barrier to infection. This may vary with the type of food. Milk products can reduce acidity due to the buffering power of casein. The use of anti-acid medicines can also increase susceptibility to foodborne disease.

27 Gazdaszervezet Korábbi élelmiszer-eredetű megbetegedések
következményei: Tartós immuntitás Hepatitis A Rövid idejű immunitás Campylobacter V. cholerae Nincs immunitás Salmonella Other factors associated with the host include immunity resulting from previous infections. Some diseases leave a lasting immunity. Others provide short term-protection. Salmonellosis leaves no immunity.

28 Minimális fertőzési dózis
EPEC 106 ETEC 106 Shigella, EIEC EHEC 10 L. monocytogenes magas, de a veszélyeztetett csoportokban kb. 100/g élelmiszer Salmonella ( kiv. typhi ) 106 ( ennél kevesebb (pl ) zsíros élelmiszerekkel okozhat fertőzést, mint a csokoládé vagy a sajt) Campylobacter kb. 500 Salmonella typhi V. cholerae 106 The minimum infective dose has been estimated for some organisms under particular sets of conditions but is unknown for others. However, we can see that estimates are either high or low. In either case, growth in foods may be required to permit a sufficient number of organisms to pass through the gastric acid. Under certain conditions, disease may be caused by a single organism.

29 Élelmiszermérgezést okozó baktériumok
A mérgezés az élelmiszeren belüli toxintermelésnek köszönhető Bacillus cereus Clostridium botulinum Escherichia coli (ETEC) Staphylococcus aureus Four organisms concern us. With one exception, they are Gram-positive, that means that they share certain characteristics of their cell walls (made evident by the so- called Gram-stain). S.aureus and E. coli are associated with humans, the former as a skin commensal and the latter as a gut commensal. The others are found in the terrestrial environment. Clostridium botulinum are anaerobic but B. cereus can grow in the presence or absence of air.

30 Mi a toxin? Olyan méreganyag, ami állatokban, növényekben és mikroorganizmusokban található Botulinum toxin akkor keletkezik, amikor a C. botulinum szaporodik – ez egy FEHÉRJE Kb. 500g elég az emberiség elpusztításához! C. botulinum produces one of the most toxic substances known. It is a protein formed when the organism grows.

31 A C. botulinum okozta megbetegedés jellemzői
Jellemző Proteolytic típus Non-proteolytic típus Kezdet 2h - 8 nap ugyanaz Időtartam Napoktól néhány hónapig Tünetek Émelygés Hányás Látási zavar, Szédülés Toxikus dózis mg mg The onset of intoxication with botulinum toxin is variable. In severe cases, the symptoms may persist for several months. Nausea and vomiting occur, due to an action not at the enteric level but at the level of the central nervous system. Visual disturbance, due to decreased coordination of the eye muscles, is often seen quite early. In severe cases, the respiratory muscles are paralysed and artificial life support is necessary. The different types of the organism, proteolytic (able to break down proteins) and non-proteolytic (unable to break down proteins), produce toxins of different toxic doses.

32 A S. aureus okozta megbetegedés jellemzői
Lappangási idő 1 - 6h Fő tünetek megjelenése h Émelygés Hányás Hasmenés Hasi fájdalom NINCS Láz Néhány esetben eszméletvesztés és kiszáradás Intoxication by S. aureus can be serious; the onset of symptoms is rapid. It can cause dehydration and shock followed by prostration. It causes violent diarrhoea and vomiting but no fever. Absence of fever is quite common in cases of intoxication. The toxin is formed when the organism grows in food and the symptoms occur after ingesting the preformed toxin. It is heat resistant, which means that although there may be no organisms detectable in the food, the toxin remains.

33 A Bacillus cereus okozta megbetegedés jellemzői
Hasmenéses szindróma Hányásos szindróma Jellemző Tünetek kezdete h h A tünetek időtartama h h Tünetek Hasi fájdalom, Émelygés és vizes hasmenés hányás Baktériumszám a fertőzött élelmiszerben 108 / g 108 / g Intoxication by this organism is much more common than that with botulinum toxin. The onset is rapid and two syndromes are seen, the diarrhoeal syndrome being more common than the emetic syndrome. In foods associated with outbreaks, large numbers of bacteria have been detected. This intoxication is unpleasant but rarely fatal.

34 A baktériumtoxinok minimális toxikus mennyisége
Min. toxikus dózis (sejt / g) S. aureus 106 C. botulinum C. perfringens B. cereus Bacteria that produce toxin in the exponential phase of growth generally require the presence of fewer cells before a food becomes toxic. The high numbers noted for B. cereus indicate either that toxin is produced in the stationary phase, or that it is necessary to ingest high numbers of spores that go on to germinate in the gut.

35 A baktériumok szaporodás befolyásoló tényezők az élelmiszerben
Hőmérséklet Idő pH Vízaktivitás (aw) Oxigén-nyomás Tartósítószerek Mikrobák közötti kölcsönhatások These are the major factors affecting growth of bacteria. We shall examine them (in later lectures) without looking at actual mechanisms. Those of you who wish to have further information can refer to your reading list. Among these factors, microbial interactions are generally less important than the others.

36 A patogén baktériumok szaporodásához szükséges hőmérsékleti értékek
Hőmérséklet°C Min. Opt. Max. Salmonella Campylobacter E. coli S. aureus C. botulinum (proteolytic) C. botulinum (non-proteolytic) B. cereus 432 1 = Mezofil 2 = Psychrofil Here we can see the growth ranges of several foodborne pathogens.

37 A toxintermelő penészek szaporodásához szükséges hőmérsékletek
Min. Opt. Max. °C °C °C Penicillium verrucosum Aspergillus ochraceus Aspergillus flavus (aflatoxin formation) Fusarium moniliforme Under optimum conditions, mycotoxins can be produced over a wide range of temperatures. Optimum conditions for growth are not necessarily the optimum conditions for toxin formation.

38 Az élelmiszer-eredetű megbetegedések megelőzése
10° 36.5° 60° 72° 100° BIZTONSÁG VESZÉLY Forrás- pont Pasztörizálás hőmérséklete Fagyasztás Hűtés Test- hőmérséklet Temperature affects microbial growth. We have already seen the growth curve. Most bacteria found in foods grow best at °C. Some can grow rapidly at °C. Foods should never be kept in warm surroundings for more than one or two hours. In the cold, germs breed slowly. A few can multiply under refrigeration conditions (3-10°C). in the freezer, most live but do not breed. Boiling and pasteurizing kills germs in a few minutes but it does not kill heat-resistant spores or destroy heat-resistant toxins. That is why cooked food should be eaten immediately. Here we can see a picture of the critical temperatures. This is a good diagram for training people.

39 Élelmiszer-eredetű megbetegedések
következményei Fertőzés Hasmenés Alultápláltság Egyéb betegség Egyén Szociális és gazdasági hatások Közösség There are three main consequences of foodborne infections. First, there are direct influences on the individuals, such as diarrhoea and malnutrition. Malnutrition is caused by repeated episodes of diarrhoea. Second, there are secondary disease states arising from foodborne infections, creating a vicious spiral of diseases. This is the target for preventive measures. Third, there are socio-economic effects on the community.

40 A legjelentősebb faktorok, melyek hozzájárulnak
az élelmiszer-eredetű megbetegedéshez Keresztfertőzés Szennyezett berendezés Romlott/egészségre káros élelmiszer Kémiai szennyeződés Rovarok / rágcsálók Fertőzött dolgozók Fertőzés Elégtelen főzés / ismételt hőkezelés Túlélés Elégtelen hűtés / melegen tartás Szaporodás A problem occurs when factors combine to favour contamination, allow survival, or allow growth. Contamination and recontamination are due to many factors. Survival and growth depend on temperature and time. All these factors should be controlled by GMP/GHP if properly applied (see also M1L4, p. 6).

41 Összegfoglalás A baktériumok károsak vagy hasznosak lehetnek.
Baktériumokat, élesztőket és penészeket használhatunk az élelmiszerek tartósításához Élelmiszer-eredetű megbetegedést okoznak a baktériumok, penészek, vírusok és paraziták A baktériumok és a penészek megsokszorozódnak az élelmiszerekben és toxint termelhetnek Vírusok és paraziták nem szaporodnak az élelmiszerekben Megértve azokat a faktorokat, melyek a mikrobák szaporodását befolyásolják, lehetőségünk van az élelmiszerekben való ellenőrzésükre In this lecture, we have had an overview of microorganisms. We have seen that FBD is caused by bacteria, moulds, viruses and protozoa. They not only cause infections but some also produce toxins. The behaviour of bacteria depends on the food in which they are found. If we understand contamination, and factors affecting survival and growth of the different bacteria, we may be able to control them in foods.

42 Fertőző patogének - összefoglalás
A legtöbb élelmiszer-eredetű megbetegedést elsősorban a fertőző, mint a toxikus patogének okozzák Világviszonylatban a legfontosabbak Salmonella Campylobacter Shigella E. coli A fertőzési mennyiség különböző és függ gazdaszervezettől organizmustól élelmiszertől Ritka a tartós immunitás Esszenciálisak a megelőző tevékenységek Védőoltás csak a Hepatitis A ellen van

Letölteni ppt "Mikrobiológiai veszélyek"

Hasonló előadás

Google Hirdetések