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Biomedical subjects

J Oosterom

Publications and source records attributed to J Oosterom.

16 recordsLinked to original sources
PubMed1991

Campylobacter: pathogenicity and significance in foods.

In the last 10 years Campylobacter jejuni has emerged as the most frequent cause of bacterial gastroenteritis in man. Acute enterocolitis, the most common presentation of C. jejuni infection, can affect persons of all ages. C. jejuni has been found in virtually every country where investigations have been carried out. The frequent finding of dysenteric stools suggests that mucosal damage due to an invasive process analogous to that seen in shigellosis is important in the pathogenesis. Campylobacteriosis in man is mainly a foodborne infection in which foods of animal origin, particularly poultry, play an important role. Epidemiological investigations have demonstrated a significant correlation between the handling and consumption of poultry meat and the occurrence of Campylobacter enteritis. Barbecues appear to present special hazards for infection, because they permit easy transfer of bacteria from raw meats to hands and other foods and from these to the mouth. Milk is sometimes found to be contaminated and consumption of raw milk has caused several outbreaks of campylobacteriosis. Campylobacter can remain viable in fresh cheese for only a short period of time. The organism is also found in shellfish, such as clams. Campylobacter is probably very vulnerable to factors such as high temperatures and dry environments, and also to the presence of oxygen in atmospheric concentrations. Therefore, it is assumed that the organism does not persist in products like pelleted feed, meals, egg powder and spices, which are often contaminated by Salmonella. A number of preventive measures on different levels, taken simultaneously, are needed to reduce the incidence of campylobacteriosis in man.

Animals↗
PubMed1991

Epidemiological studies and proposed preventive measures in the fight against human salmonellosis.

A large number of countries annually report high numbers of Salmonella infections in man. Since it is estimated that these reported cases only represent 1 to 10% of the real incidence of this disease, it must be concluded that human salmonellosis is a serious problem all over the world. The major source for human salmonellosis is caused by farm animals, which may frequently be intestinal carriers of the organism. Particularly pigs and poultry are incriminated in this respect, and, to a lesser degree, cattle and sheep. Because generally no symptoms of disease can be observed, these animals usually pass veterinary slaughterhouse inspection without restrictions. During slaughter however, intestinal material, often containing Salmonella bacteria, pollutes the surface of carcasses, which in later stages may lead to extensive Salmonella contamination of meat and meat products. Additionally, milk may also be contaminated by faecal material during collection, while eggs may be externally contaminated by faecal material or internally infected by way of transovarial transmission. Cross-contamination in slaughterhouses, in butchers' shops and in the kitchen may add to the problem. Human infection occurs when animal products are improperly handled during final preparation. This may happen at home, but also in large kitchens of restaurants, hospitals, institutions and factories. In most instances infection is related to cross-contamination from meat to foods that are to be consumed without further treatment, such as bread, salads and fruits, to improper heating of the animal products themselves, as for instance with eggs, or even to the consumption of raw animal products, as may be the case with meat and milk. The faecal excretion of Salmonella by human patients, wild and domesticated animal carriers, as well as the disposal of slaughter offal, sludge, slurry and manure contributes to an overall Salmonella spread in the environment. This may lead, by way of contamination of surface waters and colonisation of birds, rodents and insects, to the contamination of animal feeds or directly contribute to the re-colonisation of farm animals. In order to solve the problem of human salmonellosis, measures should be taken simultaneously on several levels. Since there are so many transmission ways, particularly in the environment and on the farm, isolated actions, such as the decontamination of animal feed, will never give lasting results. Likewise, the sole responsibility for the problem should never lie with the consumer.(ABSTRACT TRUNCATED AT 400 WORDS)

Animal Husbandry↗
PubMed1987

Epidemiological studies on Salmonella and Campylobacter jejuni.

An overview is given of investigations concerning the epidemiology of Salmonella, carried out at the National Institute of Public Health and Environmental Hygiene in Bilthoven, The Netherlands, during the last thirty years. It is made clear that Salmonella, because of its ubiquitous occurrence and its large variety in sero- and phage-types, is the organism of choice to study the epidemiological pathways of pathogens between man, animals and the environment. It is demonstrated that these are in fact the pathways of faecal contamination, and therefore have validity for a larger number of bacterial, and perhaps even parasitic and viral, micro-organisms. This last statement is illustrated by the presentation of studies on the epidemiology of Campylobacter jejuni.

Animals↗
PubMed1987

Kinetics of anti-Campylobacter jejuni monomeric and polymeric immunoglobulin A1 and A2 responses in serum during acute enteritis.

The intensity and kinetics of the serum polymeric and monomeric immunoglobulin A1 (IgA1) and IgA2 antibody responses to Campylobacter jejuni were analyzed. A rapid and marked serum IgA antibody response involving both the monomeric and polymeric components of IgA was observed after C. jejuni infections. IgA antibodies reached a peak of activity in serum during week 2 after the first symptoms of enteritis, about 10 days before the peak of IgG activity. Polymeric IgA accounted for most of the anti-C. jejuni activity at the peak of the IgA response (median, 90%; range, 44 to 98%) but rapidly disappeared from serum over a few weeks. In contrast, the serum monomeric IgA antibody response was low and was maintained over a prolonged period of time. Anti-C. jejuni IgA detected in the serum of healthy blood donors was mainly monomeric (median, 83%; range, 17 to 94%). In both the patients and the positive controls, IgA1 was the predominant (greater than 85%) subclass involved, even when the IgA antibody response was mainly polymeric. Our results suggest that polymeric IgA antibody responses are linked to a strong or persisting antigenic stimulation or both. Polymeric IgA antibodies appear to be a potential marker of acute C. jejuni infections, and their determination could provide a useful tool for the serological diagnosis of recent C. jejuni infections.

Acute Disease↗
PubMed1986

[The hygienic disposal and rendering of dead animals and animal waste].

In this publication an overview is made of both the fundamental and practical approaches laid down in the 'WHO Guidelines on the hygienic disposal and rendering of dead animals and animal wastes to protect human and animal health'. It describes methods that can be used both in developed and developing countries for the hygienic disposal and rendering of contaminated animal materials. In view of the various veterinary-hygienic measures that might be taken a distinction is made between low-risk materials (for instance slaughter offal of healthy animals) and high-risk materials (for instance animals that died because of infectious diseases). The hygienic disposal of low-risk materials is usually done by sterilisation in autoclaves or by cooking, so that proteins and fat may be re-used, mostly in the form of animal feed components. High-risk materials should at the least be sterilised or otherwise be burnt. Attention is also paid to the hygiene in rendering plants, particularly concerning the avoidance of cross-contamination from raw to decontaminated materials. Finally aspects of environmental hygiene are discussed and attention is paid to the protection of the personnel that is involved in the hygienic disposal and rendering of dead animals and animal wastes.

Abattoirs↗
PubMed1986

[Hygiene in poultry processing].

Investigations during the last two decades directed to measures designed to improve hygiene in poultry slaughtering are reviewed. Attention is paid to investigations on the degree and origin of bacterial contamination as well as on the mechanisms of attachment. Finally, future developments with regard to hygiene in poultry processing are discussed.

Animals↗
PubMed1986

[Bacterial cycles].

As a result of several epidemiological investigations on Salmonella it was realized that bacterial cycles occur in the environment which are of direct importance in bacterial contamination of man, animals and food. The manner in which knowledge of these bacterial cycles may help in identifying the most important routes of transmission and designing adequate measures to reduce the hazards to public health wherever possible are described.

Animals↗
PubMed1985

[Incidence of Clostridium botulinum on cattle farms].

Clostridium botulinum, mainly type B, was constantly found to be present on cattle farms. The organism was isolated both from samples of the soil of pastures and from the faeces of cattle during the winter housing period. The number of C. botulinum type B in samples of soil varied from 10 to 300 organisms per 100 grams. Contamination with C. botulinum was found to be of a similar order of magnitude on farms on which pastures are regularly dressed with sewage sludge. C. botulinum was detected in 13 per cent of the faecal samples (420 samples of one gram each). Particularly grass silage pits prepared with wilted grass were found to provide a possible link between contamination of pastures and cattle.

Animals↗
PubMed1985

Serotyping of and hippurate hydrolysis by Campylobacter jejuni isolates from human patients, poultry and pigs in the Netherlands.

Three hundred strains of Campylobacter jejuni, isolated from human patients, poultry and pigs were serotyped according to the Penner-Lauwers system and furthermore tested for hippurate hydrolysis. Serotyping showed a close relationship between human and chicken strains, whereas there was little relationship between human and pig strains. A similar conclusion was drawn from the results of the hippurate hydrolysis test: 86% of human and 94% of poultry strains were positive, whereas 91% of pig strains were negative. These data confirm the conclusions from epidemiological investigations, according to which poultry is a major source of human campylobacteriosis, while pigs are rarely so.

Animals↗
PubMed1985

Evaluation of an enzyme-linked immunosorbent assay (ELISA) for the detection of Campylobacter jejuni antibodies, and comparison with a complement fixation test (CFT).

An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of total anti-Campylobacter immunoglobulins in human sera. In this assay disintegrated Campylobacter bacteria were used as the antigen. Absorption tests including other possibly enteropathogenic bacterial species showed that the ELISA system displayed a high immunological specificity for Campylobacter. Using this ELISA it was found that in about 80% of Campylobacter patients these Campylobacter antibodies are produced to almost maximal levels within 8 days after onset of disease, and that they may persist for at least 4 months. Indeed, Campylobacter antibodies were demonstrated at low levels in a large number of control sera. However, accepting an antibody titre of 1:640 as indicative of Campylobacter infection, the statistical sensitivity of the ELISA system was 77% and the specificity 95%. In an epidemiological survey a high association was demonstrated between the severity of Campylobacter-related symptoms and antibody titre values. Assessment of Campylobacter antibody titres by means of this ELISA and by a complement fixation test in 92 sera from index patients and contacts with and without symptoms showed a high association of results.

Antibodies, Bacterial↗
PubMed1985

Prevalence of Campylobacter jejuni and Salmonella during pig slaughtering.

It was found that 79% of healthy pigs, slaughtered in three different slaughterhouses in the Netherlands, were intestinal carriers of Campylobacter jejuni (mean number 4000 cfu per g), and 21% of the same pigs had Salmonella in the intestinal tract (mean number 10 cfu per g). Immediately after slaughter, Campylobacter was swabbed from 9% of the carcasses and Salmonella from 13%. It is concluded from these data that most of the contamination on carcasses does not originate directly from the intestinal tracts of the animals but rather from surfaces, equipment, and utensils in the slaughter hall. It was demonstrated that Salmonella could survive in the slaughter hall, whereas Campylobacter died off, probably due to its vulnerability to drying conditions and its inability to grow at temperatures below 30 degrees C. Campylobacter was not isolated from the carcasses after cooling. It had been shown earlier that this again was caused by dry conditions, brought about by the use of forced ventilation in the cooling rooms. In an additional investigation, Campylobacter was not isolated from 248 samples of minced pork (10 g each), whereas Salmonella was found in 13% of these samples.

Abattoirs↗
PubMed1979

[Epidemiological studies on Salmonella in a particular area ('Walcheren Project'). IV. The incidence of Salmonella in the sewage system, in faeces of man and pets as well as in shops, kitchens and lavatories in the village of Aagtekerke (author's transl)].

As part of the epidemiological investigations on Salmonella on the island of Walcheren, the contamination of sewage water in the village of Aagtekerke was studied over a prolonged period. These studies showed that this sewage water was frequently contaminated by large numbers of Salmonella. In the present study, efforts were made to find an answer to the question of the origins of this contamination. For this purpose, the incidence of Salmonella in the sewage system, in faeces of man and pets as well as in shops, kitchens and lavatories in the village of Aagtekerke was studied for a period of three weeks in June 1977. In addition to the findings in the sewage system (including the inlet water and effluents of the sewage works) which were positive for Salmonella, this organism was only isolated from a few faecal samples of human and animal origin. Serotyping showed that the strains isolated from human faeces were similar to those found to be present in the sewage system. This fact, in conjunction with the results of the bacterial counts. suggests that the sewage system was only contaminated by the small number of carriers. The reduction of contamination observed in the sewage system during the period of investigation could be evidence of the fact that Salmonella organisms cannot survive by themselves in an environment of this type, at least not at the temperatures recorded on collecting samples from the sewage water. Growth of organisms under more favourable conditions cannot be ruled out. An inquiry on dietary habits and kitchen hygiene of the local population showed that contamination within households. Origination with the food, is a real possibility.

Adult↗
PubMed1978

[Studies on the possibility of producing broilers free from Salmonella (author's transl)].

The results of the present study show that the only method by which broilers could be reared free from Salmonella would be to adopt a number of radical measures at the same time. These measures include the production of Salmonella-free one-day chicks, decontaminating the feed, thorough cleansing and decontamination of the houses and preventing the introduction of Salmonella from the environment. Adopting separate measures was found to have a very slight effect.

Animal Feed↗