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Biomedical subjects

J W van der Giessen

Publications and source records attributed to J W van der Giessen.

18 recordsLinked to original sources

Epidemiology of Cryptosporidium spp. and Giardia duodenalis on a dairy farm.

Prevalences of Cryptosporidium spp. and Giardia duodenalis in relation to age and season were investigated on a dairy farm in The Netherlands over the course of 1year. The whole herd was sampled five times, whereas calves younger than about 2 months were sampled every 2-3 weeks. Associations between diarrhoea and presence of one or more pathogens (Cryptosporidium spp., G. duodenalis, rotavirus) were investigated. Potential transmission routes of Cryptosporidium spp. were evaluated and positive samples of Cryptosporidium spp. and G. duodenalis were identified to genotype level by PCR microsatellite identification and fingerprinting. Shedding of Cryptosporidium spp. was found in all age categories but peaked in calves 1-3 weeks old (39.1%). Herd prevalence of shedding for Cryptosporidium spp. varied from 2.4% in June to 22.2% in December. Shedding of G. duodenalis was found in all age categories but peaked in animals 4-5 months old (54.5%). Herd prevalence of shedding for G. duodenalis varied from 0.8% in June to 15.5% in February. Cryptosporidium spp. and rotavirus appeared to be significantly associated with diarrhoea in calves. Microsatellite analysis showed two different subtypes (C3 and C1) of Cryptosporidium parvum calf strains. Two genotypes of G. duodenalis were found, one positive by A lineage specific PCR and thus closely related to human genotypes and one genotype, which was negative by A and B lineage specific PCR. The results indicate that cow-to-calf and indirect calf-to-calf transmission both are important routes for acquiring infection with Cryptosporidium spp.

Age Factors↗

Diagnosis and epidemiology of Trichinella infections in wildlife in The Netherlands.

Trichinella infections in foxes and wild boars were studied to determine the prevalence of infection in wildlife in the Netherlands. Muscles of 429 forelegs of foxes (Vulpes vulpes) and diaphragms of 11 wild boars (Sus scrofa) were artificially digested. Single larvae of Trichinella were identified at species level using random amplified polymorphic DNA (RAPD-PCR). In addition, an ELISA using ES antigen was used to test serum samples of 458 wild boars. The prevalence of Trichinella in foxes ranged from 3.9% in the the eastern part of the country, 13.1% in the central part of the country and 1.3% in the most western part of the country. Trichinella larvae of foxes were identified as T. britovi. In most samples, identification of larvae did not show reproducible results. The serological prevalence of Trichinella infections in wild boars was 6.8%. Wild boar populations are located in the central and in the southern part of the country. Trichinella larvae of wild boar were identified as T. spiralis. These results show that two Trichinella species are involved in the epidemiology of trichinellosis among wildlife. On the basis of previous reports, the present results suggest that the prevalence of Trichinella infection in wildlife is increasing in the last 20 years.

Animals↗

Genetic diversity within the genus Trichinella as shown by cleavage fragment length polymorphism analysis.

The genetic diversity within the genus Trichinella was studied using cleavage fragment length polymorphism (CFLP) analysis. The CFLP method generates specific fingerprints based on single nucleotide mutations. By this method the amplified intergenic regions of the 5S rRNA genes of the eight different genotypes of Trichinella were analysed. The CFLP pattern of T. spiralis was completely different compared with the sylvatic species T. britovi, T. nativa, T. nelsoni, and the genotypes Trichinella T5, Trichinella T6 and Trichinella T8. The T. pseudospiralis intergenic region can be differentiated by size from the other species of Trichinella.

Animals↗

Sero-surveillance of wild boar in The Netherlands, 1996-1999.

From 1996 to 1999, blood samples were collected from wild boar shot during the hunting season in Crown properties, national parks and the free wildlife belt in the Netherlands. Sera were screened for the presence of antibodies against classical swine fever virus (CSFV), swine vesicular disease virus (SVDV), Aujeszky's disease virus (ADV) and Trichinella spiralis. The results of the sero-surveillance system indicate that CSFV, SVDV and ADV are uncommon within the wild boar population. Hence, the wild boar population is not thought to be an important reservoir of these viruses in the Netherlands. Infection with ADV and CSFV is endemic in the wild boar population in Germany. Since contact between the wild boar populations of Germany and the Netherlands cannot be excluded in the southern part of the Netherlands, continuation of the sero-surveillance system seems appropriate. In the decade before 1998, no antibodies to Trichinella spp. were found in the wild boar population of the Netherlands. The detection of some seropositive animals during the hunting season of 1998-1999 corresponds to the previous findings in wild boar before 1988. However, the recent data do not have consequences for the pig industry of the Netherlands, since the country has been considered Trichinella-free for many decades.

Animals↗

Detection of Echinococcus multilocularis in foxes in The Netherlands.

Echinococcus multilocularis was demonstrated in 5 out of 272 foxes in The Netherlands close to the border with Germany and Belgium. Besides microscopic examination of mucosal scrapings, two different PCR assays were used based on the detection of E. multilocularis DNA in colon content. Two distinct areas in The Netherlands were positive for E. multilocularis. Two positive foxes were found in the northern province of Groningen and three positive foxes were found in the southern province of Limburg. Both PCR assays detected more positive foxes compared to microscopic examination of the intestinal content. This is the first report of E. multilocularis in foxes occurring in The Netherlands.

Animals↗

Human exposure to Mycobacterium paratuberculosis via pasteurised milk: a modelling approach.

Paratuberculosis is a disease of cattle caused by infection with Mycobacterium paratuberculosis, and it has been suggested that this bacterium may also play a role in the aetiology of Crohn's disease in humans. M paratuberculosis is shed in the milk and may be able to survive pasteurisation. Therefore, people may be exposed to it by the consumption of pasteurised milk. The risk of such exposure has been analysed using a modelling approach and the model has been used to evaluate the effects of intervention measures at different points in the potential route of transmission. On the basis of data from the literature and expert opinion, an initial point estimate of the exposure level of about 0-5 cfu/litre pasteurised milk was derived, mainly due to milk from clinically affected animals. The model indicates the need for quantitative data on variations in the shedding rates of M paratuberculosis in faeces and milk, and the levels of faecal contamination of milk. Such data are essential for a proper analysis of potential exposure, and may result in a 100-fold increase in the estimated median level of exposure.

Animals↗

Trichinella britovi in foxes in The Netherlands.

An overall prevalence of 3.9% of Trichinella infection was observed in the fox population in The Netherlands. Random amplified polymorphic DNA analysis of individual muscle larvae demonstrated the presence of Trichinella britovi. This is the first report of T. britovi, etiological agent of sylvatic trichinellosis, in one of the most densely populated countries in Europe and, consequently, the occurrence of cannibalism and scavenger behavior of foxes in areas with a high human population density. The presence of T. britovi in the fox population in these areas appears to be without consequences for commercial pig farming.

Animals↗

Diagnosing salmonellosis in horses. Culturing of multiple versus single faecal samples.

Three rectal faecal samples were taken at 24-hour intervals from 136 horses in order to investigate whether multiple faecal cultures yield a greater number of Salmonella-positive horses compared to single faecal cultures. Of these 136 horses, 89 were suspected of salmonellosis on clinical grounds and 47 belonged to a control group. From the 'Salmonella suspected' group, 22 horses (25%) were Salmonella positive on one or more occasions. Only twelve of these 22 positive horses (55%) were positive at first sampling. Of the control group, only three horses (6%) were positive for Salmonella. Thirty-one (69%) of the 45 positive cultures from the 'Salmonella suspected' group were found only after enrichment in Selenite broth. From the results of the present study it is concluded that multiple faecal cultures are superior to single faecal cultures for diagnosing clinical salmonellosis in horses and that there is no relation between the course of the disease and whether the Salmonellae were cultured directly or indirectly, after enrichment in Selenite broth. Salmonellae were cultured from the faeces of horses treated with antibiotics before their referral, even when the isolated strain was sensitive to the antimicrobial drug used by the practitioner.

Animals↗

Comparison of the 23S ribosomal RNA genes and the spacer region between the 16S and 23S rRNA genes of the closely related Mycobacterium avium and Mycobacterium paratuberculosis and the fast-growing Mycobacterium phlei.

The 23S rDNA sequences of Mycobacterium paratuberculosis, M. avium and M. phlei and the sequences of the spacer regions between the 16S and 23S rRNA genes were determined. The overall 23S rDNA sequence identity between M. paratuberculosis and M. avium was 99.7% (nine mismatches), showing the very close relatedness of these mycobacteria. Evolutionary distances between the five known mycobacterial 23S rRNA/rDNA sequences and those of other Gram-positive G + C-rich bacteria were determined. The 23S rDNA sequences of mycobacteria showed two inserted regions compared to the other bacteria. A mycobacterial unique region contained one mismatch between M. paratuberculosis and M. avium. An Actinomycetales-specific insertion, consisting of 111 nucleotides, was completely identical for M. paratuberculosis and M. avium. The sequence of the intergenic spacer region between 16S and 23S rDNA had a length of 278 bp for M. paratuberculosis and M. avium with only two mismatches. The spacer region of the fast-growing M. phlei was 85 bp longer. No tRNA-encoding region was found in the spacer region.

Actinomycetales↗

Phylogenetic position of Taylorella equigenitalis determined by analysis of amplified 16S ribosomal DNA sequences.

The 16S ribosomal DNA sequence of Taylorella equigenitalis (formerly Haemophilus equigenitalis), the causative organism of contagious equine metritis, was determined. A phylogenetic analysis of this sequence revealed a phylogenetic position of T. equigenitalis in the beta subclass of the class Proteobacteria apart from the position of Haemophilus influenzae, which belongs to the gamma subclass of Proteobacteria. A close phylogenetic relationship among T. equigenitalis, Alcaligenes xylosoxidans, and Bordetella bronchiseptica was detected; Spirillum volutans and Chromobacterium fluviatile (Iodobacter fluviatile) were in the same group but slightly removed. This relationship is surprising in view of the considerable differences in the G + C contents of the genomes of these bacteria.

Alcaligenes↗

Rapid detection and identification of Mycobacterium avium by amplification of 16S rRNA sequences.

An assay that is based on the amplification of 16S rRNA sequences and that was initially developed to detect Mycobacterium paratuberculosis in cattle was used to test 20 serotypes of the Mycobacterium avium complex (MAC) and atypical mycobacterial species not belonging to MAC. Only serotypes 1 to 6 and 8 to 11, designated M. avium, were detected by the assay, indicating that it can be used for the rapid detection and identification of M. avium. The results of the assay for clinical samples from animals suspected of having mycobacterial infections indicated that it can also be used directly on clinical samples.

Animals↗

[Salmonella dublin infections in cattle, a review].

In this review Salmonella dublin infections in cattle are discussed. Pathogenic pathways and clinical symptoms in calves and cows are mentioned in addition to diagnostic methods like post mortem examination, bacteriological methods and serology. Epidemiological aspects like carrier state in cows and the survival of the bacteria in the environment are discussed. Without reliable tests to detect carriers, we suggest that control of this infection on farms must be based on prevention, improved hygiene and therapeutic measures. Vaccination can be used to improve the immunity of the herd.

Animals↗

[Salmonella dublin on dairy farms in the North of the Netherlands].

During the last century many calves and cows with Salmonella dublin infections are diagnosed in the North of the Netherlands, especially in the province of Friesland. In this paper are retrospectively traced the problems by paratyphoid infections in cattle, from 1919 till now, the diagnosis of which was made at the Animal Health Service in Friesland and North-Netherlands. Over the decennia a decrease is noticed for the percentage of necropsies of calves with S. dublin infections, although some irregular peaks appear. However since 1988 an increase is observed in dairy farms with S. dublin problems, revealing high mortality in calves, abortions and sick cows.

Animals↗

Amplification of 16S rRNA sequences to detect Mycobacterium paratuberculosis.

A probe based on 16S ribosomal RNA (rRNA) sequences was developed to detect Mycobacterium paratuberculosis, the causative agent of Johne's disease in cattle. Three universal primers were used to sequence the amplified fragments of the 16S rRNA gene of various species of mycobacteria. When the nucleotide sequences were analysed, a deletion was detected in the sequence of the fast-growing species. An oligonucleotide probe (P) directed to this region was synthesised and hybridised directly with total RNA of various mycobacterial strains in a dot-spot assay. The probe detected M. paratuberculosis, some other slow-growing mycobacteria of the M. avium-intracellulare (MAI) complex, and one atypical strain, M. gordonae. To increase the sensitivity of the probe, a 413-bp fragment of the 16S rRNA gene of M. paratuberculosis between P and a second oligonucleotide primer was amplified and hybridised with a M. paratuberculosis/M. avium-specific probe. When faecal samples of cattle were tested, all culture-positive samples were positive in the PCR assay.

Animals↗

Evaluation of the abilities of three diagnostic tests based on the polymerase chain reaction to detect Mycobacterium paratuberculosis in cattle: application in a control program.

Three assays for the specific detection of Mycobacterium paratuberculosis by dot spot hybridization of polymerase chain reaction products were applied to fecal samples of dairy cattle. The first two tests used polymerase chain reaction primers and a DNA probe derived from M. paratuberculosis-specific sequences of the 16S rRNA gene and insertion element IS900, respectively. These two tests were carried out on spiked fecal samples to determine the detection limits. The 16S rRNA test was able to detect 10(7) bacteria per g of feces, and the IS900 test detected 10(4) to 10(5) per g of feces. Next, we studied the usefulness of these tests in a control program for paratuberculosis. Therefore, the tests and a third, commercially available, test (IDEXX Corp.) were used twice with an interval of 3 months on fecal samples of 87 cows from two dairy herds with a history of Johne's disease. We compared the results of these tests with those of culturing. This showed that the tests are specific but that the sensitivity ranged from 3 to 23%. Further improvement of the sensitivity is needed before the tests can be used in a control program to eradicate Johne's disease.

Animals↗

[The polymerase chain reaction].

The polymerase chain reaction (PCR) is a technique that enables us to prepare in a test tube billions of copies of a specific piece of DNA. The principles and practical aspects of the PCR are exposed. Within veterinary medicine the most important applications are expected to be i) the diagnostics of infectious diseases and ii) the detection of genetic disorders or desired genetic traits. The PCR can be carried out on a multitude of samples ranging from mummies to paraffin-embedded tissue specimens. However, inhibitors present in e.g. serum, urine and faeces have to be removed.

Animals↗

Swine brucellosis in Indonesia.

Brucella suis biotype 1 was isolated from 13.1% of the pigs slaughtered in Kapuk Jakarta, West Java and from 15.09% of the pigs slaughtered in Surabaya, East Java. The prevalence of B. suis by means of the Rose Bengal Plate Test, was 22.3% for West Java and 14.9% for East Java. The Rose Bengal Plate Test detected more B. suis infected animals (73% of the infected animals) than did the Complement Fixation Test (41%) and the Serum Agglutination Test (54.5%). The high infection rate is a potential health danger for the abattoir workers.

Agglutination Tests↗