Biomedical subjects

W Wolter

Publications and source records attributed to W Wolter.

At least 19 recordsLinked to original sources

PubMed2005

Pattern of enterotoxin genes seg, seh, sei and sej positive Staphylococcus aureus isolated from bovine mastitis.

PCR detection of the genes encoding the newly described staphylococcal enterotoxins (SE) SEG, SEH, SEI and SEJ was carried out for 104 randomly selected Staphylococcus aureus field strains isolated from cases of bovine mastitis. Sixty-one (58.7%) isolates were positive for one or more of these novel enterotoxin genes. Thirty-six field strains were classified as carrier of seg, 22 of sei gene and 23 were positive for sej gene. None of the 104 investigated ruminant S. aureus strains carried the seh gene. Thirty-seven of these S. aureus strains showed a combination of genes encoding enterotoxin types SEA to SEE or toxic shock syndrome toxin 1 (TSST 1). Thirteen cultures harboured only one, 28 two, 12 three and 8 four enterotoxin genes. Among the 61 S. aureus field strains 14 (23.0%) were positive for the genes encoding SEJ and SED and 10 (16.4%) isolates for those encoding SEG and SEI. Isolates harbouring the sed/sej genes were further characterized by macrorestriction analysis and pulsed-field-gelelectrophoresis (Pfge). Macrorestriction analysis revealed six patterns. Nine of these14 S. aureus isolates (64.3%) exhibited two patterns with a high degree of relationship (>80%).

Animals↗

PubMed2004

[Coxiella burnetii as zoonotic pathogen with special regard to food hygiene].

In Hesse, Germany, bulk milk of farms producing raw milk cheese is examined by PCR for Coxiella burnetii yearly. In 2003 the pathogen has been detected unusually frequent. By means of two examples the hygienic measures are shown, which were initiated by the veterinary administration. To detect Coxiella burnetii means always the preoccupation with unsolved questions. It is particularly uncertain, whether there is a risk of oral infection for the human being. From the point of view of food hygiene, surveys are needed urgently to work out a risk assessment. Based on this a uniform risk management and a reasonable risk communication can be fixed.

Animals↗

PubMed2003

Identification and epidemiological characterization of Streptococcus uberis isolated from bovine mastitis using conventional and molecular methods.

In the present study 130 S. uberis strains and one S. parauberis strain isolated from bovine milk samples of 58 different farms of various locations in Hesse, Germany, as well as two reference strains of each species were comparatively investigated for cultural, biochemical, serological and molecular properties. All S. uberis strains produced the enzyme beta-D-glucuronidase, while the S. parauberis strains were negative. The S. uberis and S. parauberis 16S rRNA genes were amplified by polymerase chain reaction and subsequently digested with the restriction enzymes RsaI and AvaII yielding species-specific restriction patterns. Both species were additionally identified by amplifying species-specific parts of the genes encoding the 16S rRNA, the 23S rRNA and the 16S-23S rDNA intergenic spacer region, respectively. The CAMP factor gene cfu, a potential virulence factor of S. uberis, was amplified, corresponding to a phenotypically positive CAMP-reaction, using cfu-specific oligonucleotide primers. In addition the streptokinase/plasminogen activator encoding genes skc/pauA, a second potential virulence factor, could be amplified for 126 of the 130 S. uberis but not for S. parauberis. A DNA fingerprinting of S. uberis strains, performed by macrorestriction analysis of their chromosomal DNA by pulsed-field gel electrophoresis, revealed that most of the isolates were not related to each other. However, identical DNA patterns were noted for some of the isolates within different quarters of an individual cow and also for different cows within the same farm. The generally unrelated DNA patterns indicated that S. uberis is a pathogen with multiple environmental habitats and that infections are caused by a great variety of strains.

Animals↗

PubMed2001

Diet and the duration of testosterone-dependent prostate cancer in Lobund-Wistar rats.

Hormone-related cancers in the prostate, breast, endometrium, ovary and testicle account for 30% of malignancies in humans. We have developed a unique model of spontaneous prostate cancer (PC) in Lobund-Wistar [L-W] rats that shares many of its characteristics with the natural history of PC in man, including (a) inherent predisposition, high production of testosterone and aging risk factors, (b) endogenous tumorigenic mechanisms, and (c) early stage testosterone-dependent and late stage testosterone-independent tumors. About 30% of L-W rats on diet L-485 develop spontaneous palpable cancer in the anterior prostate-seminal vesicle (P-SV) complex in average of 20.5 months. At age 12 months early stage spontaneous PC was prevented or reversed by testosterone-deprivation through change of diet from L-485 to soy protein isolate/isoflavone (SPII) diet, thereby preventing the late lethal clinical disease: about 75% of rats at risk of developing testosterone-independent P-SV tumors were free of detectable cancer and about 25% had developed testosterone-independent cancer at age 12 months. The duration of the dependent stage exceeded age 12 months in 75% of the rats at risk. Dietary soymeal, found in most natural ingredient diets, may promote PC tumorigenesis, but only in L-W rats.

Adenocarcinoma↗

PubMed2001

Toxin genes and other characteristics of Staphylococcus aureus isolates from milk of cows with mastitis.

In the present study, 103 Staphylococcus aureus strains isolated from milk samples from 60 cows with mastitis from eight different farms in seven different locations in one region of Germany were compared pheno- and genotypically and by identification of various toxins. On the basis of culture and hemolytic properties and by determination of the tube coagulase reaction, all of the isolates could be identified as S. aureus. This could be confirmed by PCR amplification of species-specific parts of the gene encoding the 23S rRNA. In addition, all of the S. aureus isolates harbored the genes encoding staphylococcal coagulase and clumping factor and the genes encoding the X region and the immunoglobulin G binding region of protein A. These four genes displayed size polymorphisms. By PCR amplification, the genes for the toxins staphylococcal enterotoxin A (SEA), SEC, SED, SEG, SEI, SEJ, and TSST-1 but not those for SEB, SEE, SEH, and the exfoliative toxins ETA and ETB could be detected. To analyze the epidemiological relationships, the isolates were subjected to DNA fingerprinting by macrorestriction analysis of their chromosomal DNAs. According to the observed gene polymorphisms, the toxin patterns, and the information given by macrorestriction analysis of the isolates by pulsed-field gel electrophoresis, a limited number of clones seemed to be responsible for the cases of bovine mastitis on the various farms.

Animals↗

PubMed2000

Prevention of spontaneous prostate-related cancer in Lobund-Wistar rats by a soy protein isolate/isoflavone diet.

BACKGROUND: Epidemiological surveys recorded that men in the Orient (Japan and China) consuming diets high in soy food were at low risk of developing clinical prostate cancer, compared to a relatively high risk among men in the West who consumed diets low in soy food. Soybeans contain phytoestrogens (isoflavones) with many recorded anticancer mechanisms. The Lobund-Wistar (L-W) rat is a unique model system: approximately 30% develop metastasizing adenocarcinomas spontaneously in the anterior prostate-seminal vesicle complex (P-SV), from which the tumors expand into the dorsolateral lobes. L-W rats are inherently predisposed, possibly by unusually high levels of circulating testosterone (T), to develop P-SV tumors which are T-dependent in the early stages and T-independent in advanced stages of tumorigenesis. METHODS: L-W rats were fed two diets from age 2-24 months: 1) natural ingredient diet L-485 (Harlan TekLad Diets, Madison, WI) containing soy meal, or 2) a modified starch-casein diet in which soy protein isolate/isoflavones (SPII) replaced casein as a source of protein. RESULTS: At age 24 months, 3 of 99 (3%) rats on diet SPII and 30 of 100 (30%) rats on diet L-485 developed spontaneous P-SV cancers. Rats on the SPII diet manifested a significant reduction of circulating T, approaching physiological levels. Failure of the rats on diet L-485 to prevent P-SV cancer development suggests that soy meal contained a factor(s) that blocked the antiandrogenic action of the phytoestrogen. CONCLUSIONS: The spontaneous development of P-SV cancers was significantly prevented in L-W rats consuming the SPII diet from age 2-24 months, possibly through an agonist effect of the soy-derived phytoestrogens.

Animals↗

PubMed2000

Shiga-toxin-producing Escherichia coli in faeces of healthy dairy cows, sheep and goats: prevalence and virulence properties.

The prevalence of Shiga-toxin-producing Escherichia coli (STEC) in healthy dairy ruminants was investigated between 1996 and 1998 by a multiplex polymerase chain reaction (mPCR) technique. A total of 13 552 E. coli colonies from 726 cows, 28 sheep and 93 goats out of 112 randomly selected dairy farms in Hessia, Germany were analysed. STEC strains were recovered from 131 (18.0%) cows, nine (32.1%) sheep and 70 (75.3%) goats. Further characterization of the STEC isolates showed that 89 (0.66% of the investigated colonies) of animal field strains carried stx1 gene, 64 (0.47%) stx2 gene and 57 (0.42%) stx1 and stx2 gene. Sixty (93.8%) out of 64 stx2 field strains were harboured by cows. In contrast, 74 (83.1%) out of 89 stx1 dairy animal field strains were from ovine or caprine origin. Only 17 (8. 1%) stx-positive isolates (13 from cattle, three from sheep and only one from goat) were positive for eaeA gene. Eight (9.0%) of the stx1, five (7.8%) of the stx2 and four (7.0%) of the stx1/stx2 gene-positive field strains carried the eaeA gene. The prevalence of EHEC-haemolysin (EHEC-hlyA) gene sequence was 88.8% (79 isolates) of the stx1 and 68.8% (44 isolates) of the stx2 isolates. Out of 57 stx1- and stx2-positive field-strains, 34 (59.6%) carried the EHEC-hlyA gene. E. coli O serovars O:157 and O:111 were not found. Only one isolate was positive with O26 antiserum.

Adhesins, Bacterial↗

PubMed1998

[Interspecies comparison of healing standardazed bone defects with and without autogenous bone transplantation].

This study tries to establish a basis for comparison of animal studies regarding bone defect healing. Pigs, sheep and rabbits were operated on according to a standardized scheme where each received bilateral defects of the femoral condylus. One of the defects was filled with cancellous autograft, the other remained empty. Bone defect healing was followed with several different methods of investigation, the results were put into perspective with the help of a standardized score-scheme.

Animals↗

PubMed1997

[Occurrence of Prototheca mastitis in dairy farms in Hesse].

During January 1994 and August 1996 from dairy farms in Hessia a total of 305,609 milk samples were investigated. Prototheca sp. as etiological agent of a mastitis was isolated from milk samples of seven dairy herds. According to our experiences and to several reports from various countries dealing with Prototheca infections in dairy herds, mastitis control programs should include Prototheca algae as potential pathogens. Mastitis due to this organism usually occurs in different semeiologies, one with clinical symptoms, and the other, more common type, as subclinical mastitis. In both cases, Prototheca organisms use to persist in the tissue of the mammary gland also during the dry period and antimicrobial treatment proves to be ineffective. Considering the wide distribution of these algae as saprophytes in the environment and in feces of several domestic animals, predisposing factors like a humid aerobic milieu and unsanitary milking conditions are necessary for Prototheca infections becoming manifest in the udder of dairy cows. Control measures should preferably stress the identification and removal of infected animals, in particular when the disease is sporadic in the herd. Due to the more questionable occurrence of spontaneous healing and the lack of an efficient drug, slaughtering of infected cows appears as a suitable method to eliminate the disease from the herd. Additionally, improvement of the hygiene status concerning feeding and milking management within a herd is as essential as in the control of other opportunistic udder pathogens.

Animals↗

PubMed1996