Search PubMed⌕ Search

Biomedical subjects

J Oosterom

Publications and source records attributed to J Oosterom.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1984

[Salmonella fyris in a dog].

Salmonella fyris was isolated from a three-month-old Dutch sheep dog showing symptoms of enteritis. This was the first time that this uncommon serotype of Salmonella was isolated from an animal in the Netherlands. The infection could not be traced to its source.

Animals↗
PubMed1984

[Campylobacter jejuni: an important causative agent of food infection in man. An overview].

Since a few years, Campylobacter jejuni has been identified as an important cause of acute enteritis in man. Various studies showed that Campylobacter enteritis is as common as salmonellosis, and that the symptoms often are even more severe. That this species of bacterium was not discovered until recently, was due in part to the fact that unusual methods of isolation are required; for instance, Campylobacter jejuni will only grow in a micro-aerophilic atmosphere. Campylobacteriosis was found to be a foodborne infection in the majority of cases. The organism was isolated from a large number of species of wild and domesticated animals, which, as in the case of Salmonella, are mainly asymptomatic carriers. Of farm animals, poultry and pigs are most frequently infected. The most important sources of human infection are poultry meat, unpasteurized milk, inadequately treated drinking water and, as a direct source, dogs with enteritis. Only poultry was found to play a role in the Netherlands. Pork is mostly not contaminated as Campylobacter dies during cooling of pig carcasses, death being due to the drying effect of forced ventilation. The sensitivity of Campylobacter to dry conditions, in conjunction with its inability to multiply below 30 degrees C, means that the mechanism of cross contamination, which is such an important factor in the epidemiology of Salmonella, is of minor significance in Campylobacter.

Animals↗
PubMed1984

Enterobacteriaceae as indicators of good manufacturing practices in rendering plants.

Finished products and samples from the environment of the production line in rendering plants were checked for Enterobacteriaceae and salmonellae. Improvements in hygiene and measures taken to limit multiplication of microorganisms in the dry area of the production lines resulted in reduction of both numbers of Enterobacteriaceae in environmental samples and frequency of their occurrence in finished products. Simultaneously, there was an equivalent reduction of salmonellae positives in environmental samples and finished products. Consequently, the determination of Enterobacteriaceae can be used as an effective tool to assess the improvements in good manufacturing practices.

Dust↗
PubMed1984

Epidemiological investigations on Campylobacter jejuni in households with a primary infection.

Fifty-four Rotterdam patients in which a primary infection with Campylobacter jejuni had been detected (index patients) were compared with 54 control subjects with regard to the consumption and preparation of foods 7 days before onset of illness and the keeping of pet animals. Significantly more index patients than controls had eaten chicken meat (47 v. 29; P = 0.0002), particularly at barbecues (14 v. 2; P = 0.0015). Marginally more index patients had eaten pork (47 v. 39; P = 0.048) or inadequately heated meat (13 v. 8), though in the last case numbers were too small to be statistically significant. The consumption of beef or mutton and outdoor eating (other than at barbecues) were essentially the same in both groups. There was no significant association with the keeping of pet animals, although a few more index patients had cage birds than controls (18 v. 12). Twenty-one (15%) of 136 household contacts of index patients also suffered from diarrhoea during the same period. Circumstantial evidence pointed to a common source of infection with the index patient in 13 instances (nine households) and probable intrafamilial spread of infection in six instances. Campylobacters were isolated from one of 110 swabs of kitchen work surfaces and eight of 107 swabs taken from lavatory bowls in index households.

Animals↗
PubMed1983

[Further studies on the practicability of fattening and slaughtering pigs free from Salmonella].

Attempts were made to fatten pigs free from Salmonella on a piggery which was initially contaminated with Salmonella. A specially adapted pig house was thoroughly cleaned and disinfected and efforts were made to keep out birds, insects and rodents during this experiment. Attempts were also made to purchase piglets free from Salmonella. Clean clothes, special footwear and disinfectants were used on entering the pig house. Infection with serotypes of Salmonella similar to those detected immediately prior to the experiment on the ancillary breeding farm occurred in the experimental pig house during the experiment. Other serotypes of Salmonella present on the piggery did not penetrate into the experimental pig house so that it can be concluded that all hygienic barriers functioned adequately after the piglets had been brought in. The experiment showed that the hygienic procedures had a positive effect on economic results, even though efforts to keep out Salmonella had not been completely successful. The pigs were slaughtered in two groups after the fattening period. Group one was slaughtered as usual. The pigs of group two were scalded individually with every care after slaughter and the guts were carefully removed. Examination of the carcases after slaughter showed that 46 per cent of the pigs of group one were contaminated with Salmonella, against 7 per cent of group two. It can be concluded from this finding that slaughtering does not necessarily result in further contamination by the Salmonella organisms present in the intestine but that a careful slaughtering procedure may even reduce the number of Salmonella organisms on the surfaces of the carcases of pigs.

Abattoirs↗
PubMed1983

Further research into the possibility of salmonella-free fattening and slaughter of pigs.

At a pig-fattening farm in the south-western Veluwe which was infected with salmonellas it was sought to achieve salmonella-free fattening in a specially adapted piggery. The test piggery was thoroughly cleaned and disinfected and measures were taken to exclude birds, insects and rodents. An attempt was also made to obtain salmonella-free piglets. Clean clothing, special footwear and disinfectants were used when entering the piggery. During the experiment an infection was detected in the test piggery caused by the same salmonella serotypes as had only been found immediately before the test at the breeding farm. Other salmonella serotypes occurring at the fattening farm did not find their way into the test piggery, and therefore it can be concluded that after the pigs had been brought in all the hygienic barriers functioned adequately. The test showed that the hygienic measures taken had a beneficial effect on growth performance, even though salmonellas were not entirely excluded. After fattening the pigs were slaughtered in two groups. The first group was slaughtered in the usual way, but with the second group extra care was taken with the individual singeing of the carcasses and the careful removal of the intestines. Tests on the carcasses showed that 46% of the pigs in the first group were contaminated with salmonellas as against only 7% in the second. From this it can be concluded that slaughter need not lead to further contamination by salmonellas present in the intestines; indeed, carefully carrying out the slaughter process can even reduce the contamination of the surface of pig carcasses by salmonellas.

Abattoirs↗
PubMed1983

Recovery of members of the Pasteurella-Actinobacillus-group from guinea pigs.

In the course of post-mortem bacteriological examination of conventional guinea pigs, 88 isolates belonging to the Pasteurella-Actinobacillus-group were recovered from 69 of 279 animals (25%). Most isolates were recovered from pneumonic lung, enteritic jejunum and inflamed mammary gland. No relationship was found between biotype and source of isolation. About 50% of isolates were recovered in pure culture or as the predominant micro-organism. It is concluded that members of the Pasteurella-Actinobacillus-group must be considered potentially pathogenic for guinea pigs.

Actinobacillus↗
PubMed1982

Epidemiological studies on Salmonella in a certain area ("Walcheren Project") V. Studies into the possibility of fattening pigs free from Salmonella.

Studies performed some years ago showed that Salmonella-free pigs for slaughter could be produced under experimental conditions if a number of hygienic measures were taken, such as the purchase of Salmonella-free piglets, the use of properly pelletized feed, thorough cleaning and disinfecting of the pigsty and the prevention of all contamination from the surroundings. In this paper four trials are described which examined whether pigs could also be fattened free from Salmonella under practical conditions on the farm. For this purpose one pigsty on a Salmonella-contaminated farm was used, in which the aforementioned hygienic measures were taken. Despite all these precautions it proved impossible to obtain Salmonella-free pigs. In fact, in three of the four experiments a massive Salmonella infection became manifest among the pigs. The experiments revealed a number of ways in which contamination might have occurred. The existence of these routes of infection was caused by the fact that the measures described above were not carried out accurately, an indication that it will be very difficult to meet the hygiene requirements under farming conditions. Further experiments will have to ascertain whether this is generally the case. In the third and fourth trials, the investigations were not confined to the farm, but were also extended to the period of slaughtering. These made it clear that transportation as well as the waiting time in the slaughterhouse also provided many opportunities for contamination of the pigs, in spite of extensive cleaning and disinfecting of both the cattle-truck and the lairages.

Abattoirs↗
PubMed1981

[Epidemiological studies on Salmonella in a particular area ('Walcheren Project'). V. Studies on the possibility of fattening pigs free from Salmonella (author's transl)].

Four trials were made to study the possibility of fattening pigs free from Salmonella under field conditions. One pig-sty on a Salmonella-contaminated farm was used in these studies. Previous studies had shown that Salmonella-free fattening pigs could be produced under experimental conditions. A number of hygienic measures were adopted on the farm, such as the purchase of Salmonella-free piglets, the use of correctly pelleted feed, thorough cleaning and disinfecting of the pig-sty, and the prevention of all infections originating from the environment. Notwithstanding all these measures, completely Salmonella-free pigs could not be obtained. In three out of four experiments, even a mass infection with Salmonella even became apparent among the pigs. During the experiments a number of possible routes of infection were detected. The presence of these possible routes of infection was due to the fact that the measures referred to were not carried out accurately. This suggests that it will be very difficult to satisfy the requirements of strict hygiene under field conditions. Further experimental studies will have to show whether this is usually the case. During the third and fourth trial, studies were not confined to the farm, but also extended to the period of slaughter. From these investigations it became apparent that transport to as well as the period of waiting in the slaughter-house also provide several opportunities for contamination of the pigs, in spite of extensive cleaning and disinfection of both cattle-truck and lairages.

Abattoirs↗
PubMed1981

Persistence of Clostridium botulinum type B on a cattle farm after an outbreak of botulism.

On farms involved in botulism outbreaks, cycles of Clostridium botulinum have occurred. The cycles were initiated by feeding brewers' grains contaminated with proteolytic C. botulinum type B to the cows. Spreading of manure containing feces of these cows increased the contamination of the pastures. In grass silages prepared with wilted grass from these pastures the number of C. botulinum type B organisms increased, and toxin type B was produced. Feeding cows with the contaminated silage fodder completed the cycle. Besides contamination of human foodstuffs (milk and meat), further contamination of the environment occurred. It was demonstrated that fowl may be important vectors in spreading C. botulinum.

Animal Feed↗
PubMed1980

[The presence of Campylobacter fetus subspecies jejuni in normal slaughtered pigs (author's transl)].

As part of epidemiological studies the intestinal contents of 300 normal slaughtered pigs were examined for the presence of C. fetus jejuni. Samples were collected from six different slaughter houses. From 182 of these samples (60.7 per cent) C. fetus spp. jejuni was isolated using the method as described by Lauwers (8). Isolates were confirmed by the results of the following tests: oxidase, catalase, motility, growth at 25 degrees C, production of H2S, reduction of nitrate, growth in 3.5 per cent NaCl and utilisation of glucose and urea.

Animals↗