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Biomedical subjects

J Nicolet

Publications and source records attributed to J Nicolet.

At least 73 records · Page 4Linked to original sources
PubMed1997

Lesions associated with infectious keratoconjunctivitis in alpine ibex.

Following a severe infectious keratoconjunctivitis (IKC) epizootic in free-ranging alpine ibex (Capra ibex ibex) in Switzerland in 1993, 19 animals were examined from six different populations. Mucopurulent exudates, reddened conjunctiva and mononuclear inflammatory cell infiltration in the conjunctiva and the limbic area were observed in mild cases. In more severe cases, lesions ranged from perilimbic neovascularization to corneal edema, erosion, ulceration and neovascularization accompanied by infiltration of neutrophils. Sometimes an iridocyclitis was observed. In the most advanced stages, the cornea was perforated and an anterior synechia was present. Lesions found in ibex affected with IKC indicated a non-generalized, specific ocular disease. The other organs investigated did not show alterations suggestive of changes induced by agents which might cause IKC, including Chlamydia spp. and Mycoplasma. spp. The microbiological findings indicate that Mycoplasma conjunctivae is the primary pathogenic agent causing IKC in this species in Switzerland.

Animals↗
PubMed1997

[Frequency and cost of health problems in Swiss dairy cows and their calves (1993-1994)].

Between July 1993 and July 1994 morbidity and management information related to dairy cows and their calves up to the age of 8 weeks were recorded in 113 randomly selected dairy herds. Also recorded were any costs incurred through disease and prevention. Blood and faeces were analysed with respect to selected pathogens. The health problems most frequently diagnosed in cows were reproductive and udder diseases. Calves suffered most often from diarrhea, omphalitis and pneumonia. The directly disease-related costs per cow-year on average amounted to CHF 139.44 and CHF 4.18 per calf. For prevention, farmers spent on average CHF 10.18 per cow-year. Results from the laboratory analyses indicate that in 68.1% of the farms antibodies against Leptospira hardjo and in 61.9% against Coxiella burnetii were detected. In 8.0% of the farms antibodies against Mycobacterium paratuberculosis were found. Antibodies against BVD virus was present in 99.4% of the farms. Cows from 63.7% farms were infected with gastrointestinal strongylids. Veterinary assistance was required on average 1.96 times per cow-year. In almost all reproductive and puerperal disease cases a veterinarian was consulted while lameness in the majority of cases was treated by the owner. The veterinary profession was hardly ever involved in disease prevention.

Animals↗
PubMed1997

[Cerebral listeriosis in cattle: literature review and retrospective analysis of individual cases].

Between 1990 and 1994, 89 cattle with signs of affection of the central nervous system were referred to the Clinic for Food Animals and Horses, University of Bern; in 17 cases of which, cerebral listeriosis was diagnosed. History, clinical, hematologic findings and cerebrospinal fluid analysis at admission were evaluated retrospectively. Four cattle were slaughtered after cerebral listeriosis had been diagnosed clinically because of economic reasons. Therapy, consisting of administration of penicillin (i.m./i.v.), intravenous fluids (including bicarbonate replacement), and oral fluids and rumen juice was initiated in the remaining 13 cases. Five of the 13 cattle were refractory to treatment and had to be euthanatized, one to two days after initiation of therapy. Clinical diagnosis of cerebral listeriosis was confirmed by histological examination of brain stem tissue in all nine cattle that were slaughtered or euthanatized; however, Listeria monocytogenes was isolated by standard culturing of brain stem tissue in two of these cases only. Eight to 62 months after discharge from the clinic, telephone interview with the owners of the surviving animals revealed that recovery had been uneventful and satisfactory in all of the eight cases.

Animals↗
PubMed1997

[Occurrence of Mycobacterium genavense in birds].

A total of 253 birds were investigated to determine the presence of mycobacteria. Scrapings from various internal organs were stained according to Ziehl-Neelsen, and acid-fast bacilli were found in 26 birds (10.2%). Cultivation of mycobacteria was attempted from 22 livers, 12 spleens, 14 kidneys, 12 lungs, and 9 intestines from these 26 birds. Each sample was first decontaminated using a modified sodium dodecyl sulfate method, and three media were inoculated (Bactec 12 B; Löwenstein-Jensen, Herrold). Using a Polymerase-Chain-Reaction-Restriction-Enzyme-Analysis (PRA), M. genavense could be identified in 19 of 26 birds (73%). M. avium could be isolated from three birds and M. fortuitum from one bird. In total, mycobacteriosis was the primary diagnosis made in 24 of 26 birds (92%). A presumptive diagnosis of mycobacteriosis was already made macroscopically in 14 of these birds. In the remaining 10 cases, bacteriological and histological investigations with specific staining methods were necessary for diagnosis. Several different histological changes were found. We observed individual macrophages as well as epitheloid cell proliferation, with variable, relatively mild inflammatory and fibrous reactions. We could not find any correlation between infection with a mycobacterium species and a specific tissue reaction pattern. This report demonstrates that M. genavense is an important cause of avian mycobacteriosis especially in pet birds.

Animals↗
PubMed1996

Differential and strain-specific triggering of bovine alveolar macrophage effector functions by mycoplasmas.

Mycoplasma strains being considered as pathogenic or non-pathogenic for cattle were tested on their capacity to activate bovine alveolar macrophages in vitro. Of particular interest was the behaviour of Mycoplasma mycoides ssp. mycoides small colony type (M.m.m. SC), the causative agent of contagious bovine pleuropneumonia (CBPP). Increases in procoagulant activity (PCA), tumor necrosis factor-alpha- (TNF-alpha) and nitrogen monoxide (NO) generation were tested. To minimize an influence of macrophage activation by mycoplasma growth media, mycoplasmas were cultured on embryonic calf nose epithelial cells. The three macrophage functions tested were not correlated, but were differentially induced in strain-specific manner. Four out of seven strains induced PCA, regardless of pathogenicity, and all strains promoted moderate NO generation at high concentrations. All tested M.m.m. SC strains (Afadé, L2 and PG1), and the pathogenic M. bovis, induced TNF-alpha production at low concentrations (10(6) colony forming units per ml). M.sp. serogroup 7 and the non-pathogenic M. bovirhinis and Acholeplasma laidlawii did not induce TNF-alpha up to 10(8) cfu/ml. Thus, strain-specific differences are reflected in differential macrophage activation patterns. The findings are consistent with an important role for TNF-alpha in pathogenesis of CBPP.

Animals↗
PubMed1996

Cloning and characterization of an Actinobacillus pleuropneumoniae outer membrane protein belonging to the family of PAL lipoproteins.

A 14-kDa outer membrane protein (OMP) was purified from Actinobacillus pleuro-pneumoniae serotype 2. The protein strongly reacts with sera from pigs experimentally or naturally infected with any of the 12 serotypes of A. pleuropneumoniae. The gene encoding this protein was isolated from a gene library of A. pleuropneumoniae serotype 2 reference strain by immunoscreening. Expression of the cloned gene in Escherichia coli revealed that the protein is also located in the outer membrane fraction of the recombinant host. DNA sequence analysis of the gene reveals high similarity of the protein's amino acid sequence to that of the E. coli peptidoglycan-associated lipoprotein PAL, to the Haemophilus influenzae OMP P6 and to related proteins of several other Gram-negative bacteria. We have therefore named the 14-kDa protein PalA, and its corresponding gene, palA. The 20 amino-terminal amino acid residues of PalA constitute a signal sequence characteristic of membrane lipoproteins of prokaryotes with a recognition site for the signal sequence peptidase II and a sorting signal for the final localization of the mature protein in the outer membrane. The DNA sequence upstream of palA contains an open reading frame which is highly similar to the E. coli tolB gene, indicating a gene cluster in A. pleuropneumoniae which is very similar to the E. coli tol locus. The palA gene is conserved and expressed in all A. pleuropneumoniae serotypes and in A. lignieresii. A very similar palA gene is present in A. suis and A. equuli.

Actinobacillus pleuropneumoniae↗
PubMed1996

Sequential development of resistance to fluoroquinolones and erythromycin in an isolate of Campylobacter jejuni.

A severe episode of Campylobacter jejuni gastroenteritis in a patient with HIV infection was treated with ciprofloxacin and, because of therapeutic failure, subsequently with roxithromycin. After treatment, C. jejuni was again isolated from feces and shown to be resistant to both drugs. We present molecular evidence of the sequential development of both types of resistance in the patient isolate. To our knowledge, this is the first case with documented evidence showing sequential emergence of resistance to fluoroquinolones and erythromycin in a strain of C. jejuni during treatment.

Adult↗
PubMed1996

Association between clinical presentation, biogroups and virulence attributes of Yersinia enterocolitica strains in human diarrhoeal disease.

Traditionally the enteric pathogen Yersinia enterocolitica has been differentiated into biogroups. Despite being considered as non-pathogenic, biogroup 1A isolates have constituted a sizeable fraction of strains from patients with gastroenteritis in many reports. To establish a potential clinical significance for biogroup 1A isolates of Y. enterocolitica, clinical disease in patients with gastroenteritis excreting such isolates was compared with symptoms among patients found infected with pathogenic biogroups. Clinical data and isolates of 66 patients from whom Y. enterocolitica had been isolated by direct plating were available for study. There was an association between patient age below 3 years and infection with 'pathogenic' Y. enterocolitica. The severity of gastroenteritis and other symptoms, however, did not depend on the biogroup, or the presence of the virulence plasmid in the yersinia strain isolated from the patients. Strains belonging to biogroup 1A of Y. enterocolitica showed two clusters of ribotypes, one of which encompassed most isolates recovered from humans, the other being associated with environmental isolates. This might indicate the existence of human-adapted and potentially pathogenic strains among biogroup 1A of Y. enterocolitica.

Adolescent↗
PubMed1996

Phylogenetic positions of Clostridium chauvoei and Clostridium septicum based on 16S rRNA gene sequences.

The sequences of the 16S rRNA genes (rrs genes) of Clostridium chauvoei, the causative agent of blackleg in cattle, and the phenotypically related organism Clostridium septicum were determined. After amplification of 1,507-bp PCR fragments from the corresponding rrs genes, the sequences were determined in a single round of sequencing by using conserved region primers. A sequence similarity analysis of the sequences revealed the close phylogenetic relationship of C. chauvoei and C. septicum in Clostridium cluster I (M. D. Collins, P. A. Lawson, A. Willems, J. J. Cordoba, J. Fernandez-Garayzabal, P. Garcia, J. Cai, H. Hippe, and J. A. E. Farrow, Int. J. Syst. Bacteriol. 44:812-826, 1994), which includes Clostridium carnis, Clostridium perfringens, Clostridium botulinum, and Clostridium tetani. We found that 99.3% of the nucleotides in the genes of C. chauvoei and C. septicum are identical.

Animals↗
PubMed1996

Characterization of the gene for an immunodominant 72 kDa lipoprotein of Mycoplasma mycoides subsp. mycoides small colony type.

With the aim of characterizing specific immunogenic proteins of Mycoplasma mycoides subsp. mycoides small colony (SC) type, the aetiological agent of contagious bovine pleuropneumonia, a gene encoding a major immunogenic protein of 72 kDa named P72 was cloned and expressed in Escherichia coli. The expressed protein was of the same apparent molecular mass as that produced by the parent strain. The predicted molecular mass of P72, based on the DNA-deduced amino acid sequence, was 61.118 kDa, significantly lower than the apparent molecular mass of endogenous or recombinant P72 on SDS-PAGE. Analysis of the amino acid sequence revealed a typical prokaryotic signal peptidase II-membrane lipoprotein lipid attachment site and a transmembrane structure domain in the leader sequence at the amino-terminal end of the protein. P72 was shown to be a lipoprotein and its surface location was confirmed by trypsin treatment of whole cells. An unassigned gene encoding a peptide with some similarity to P72 was found on the genome sequence of M. capricolum subsp. capricolum but not on that of Mycoplasma genitalium. The P72 gene was detected in 11/11 M. mycoides subsp. mycoides SC strains. Antiserum against recombinant P72 reacted strongly with 12/12 strains of M. mycoides subsp. mycoides SC, weakly with Mycoplasma bovine group 7 strain PG50, but not with other members of the 'mycoides cluster' or closely related mycoplasmas. Cows experimentally contact-infected with M. mycoides subsp. mycoides SC developed a humoral response against P72 within 35 d. P72 is a specific antigenic membrane lipoprotein of M. mycoides subsp. mycoides SC with potential for use in development of diagnostic reagents. It seems to belong to a family of lipoproteins of the "mycoides cluster'.

Amino Acid Sequence↗
PubMed1996

Isolation of Mycoplasma conjunctivae from conjunctival swabs of Alpine ibex (Capra ibex ibex) affected with infectious keratoconjunctivitis.

Mycoplasma conjunctivae was isolated four times from the eyes of nine Alpine ibex (Capra ibex ibex) suffering from keratoconjunctivitis. The animals examined were affected in two different outbreaks in the Swiss Alps. Parasitological and bacteriological studies, including investigations for chlamydia and mycoplasmas, were performed. The results indicate that M. conjunctivae is the primary pathogenic agent causing infectious keratoconjunctivitis in this species.

Animals↗
PubMed1996

Evolutionary origin of a monophasic Salmonella serovar, 9,12:l,v:-, revealed by IS200 profiles and restriction fragment polymorphisms of the fljB gene.

The emergence in several countries of the monophasic serogroup D1 serovar Salmonella 9,12:l,v:- provided the opportunity to study its evolutionary origin. According to current models, such a variant serovar could have arisen by horizontal transfer of a new flagellar gene to a preexisting monophasic Salmonella strain or, alternatively, by the loss of the phase 2 flagellar gene of an originally biphasic Salmonella strain. Five known serovars of Salmonella, S. panama, S. kapemba, S. goettingen, S. zaiman, and S. mendoza, could have been possible ancestors of the new variant. The profiles of the insertion element IS200, which has been shown to provide phylogenetic markers for serogroup D1 salmonellae, were analyzed in relation to the restriction fragment length polymorphisms of the phase 2 flagellar gene. Together they provide unequivocal evidence that Salmonella 9,12:l,v:- arose from a strain of S. goettingen. Analysis of the flj operon of the variant indicated that loss of phase 2 flagellar antigen expression occurred through deletion of the hin gene and adjacent DNA, thereby blocking the phase 2 flagellar gene in the off position.

Antigens, Bacterial↗
PubMed1996

Animal mycoplasmoses: a general introduction.

The nature of the smallest prokaryotes with autonomous replication, i.e. the mycoplasmas, which constitute the class Mollicutes, is presented in brief. These micro-organisms are extracellular parasites of the mucous membranes in animals. Mycoplasmas may cause infections, known as mycoplasmoses. The author describes current knowledge of the pathogenicity of mycoplasmas, especially in regard to the diverse effects on the immune system and the variability of the superficial antigens. Relatively few species of pathogenic mycoplasmas cause mycoplasmoses (both sporadic and endemic diseases) which have significant socio-economic consequences. The control and prevention of endemic mycoplasmoses can only be achieved with effective diagnostic tools and an efficient structure of epidemiological surveillance. The author recommends the encouragement of biological and genetic research on the mycoplasmas and the co-ordination of the development of diagnostic tests, including evaluation and validation in various epidemiological field situations.

Animals↗
PubMed1996

[Nephrectomy for chronic, unilateral suppurative pyleonephritis in cattle].

This report presents the case history of a five-year-old Eringer cow suffering from chronic hematuria. Results of clinical examination, ultrasonography of the kidneys, endoscopy of the bladder, and cytologic and bacteriologic analysis of the urine revealed unilateral pyelonephritis of the right kidney caused by Corynebacterium renale. Antimicrobial treatment with procaine penicillin was not successful. Therefore, nephrectomy of the affected kidney was performed through a right flanc approach in the standing animal. Follow-up examination ten months after surgery revealed normal general condition. Etiopathogenesis and diagnostic and therapeutic procedures of pyelonephritis in cattle are discussed.

Animals↗
PubMed1996

[Identification and diagnosis of Taylorella equigenitalis by a DNA amplification method (PCR)].

A polymerase chain reaction (PCR) for identification of Taylorella equigenitalis was developed. The oligonucleotide primers are based on the DNA sequence of the rrs gene of T. equigenitalis, encoding for the 16S ribosomal RNA. Analysis of 21 strains of T. equigenitalis from England, USA and Switzerland showed an amplification product of 410 bp with identical Sau3A restriction profile. The sensitivity of the PCR-Assay was estimated to detect 50 to 500 bacteria of T. equigenitalis in a mixture with frequently found contaminants. Further analysis of culture from 60 genital swabs, taken in the course of the control of the contagious equine metritis in horses and donkeys, of experimental assays as well as of two positive cases from the diagnostic showed that this PCR-assay can be used to identify and to detect strains of T. equigenitalis. In addition, preliminary results indicate that the method is also applicable for direct in vitro establishment of the presence of T. equigenitalis in clinical samples.

Animals↗
PubMed1996

[Typing of the apx toxin gene of Actinobacillus pleuropneumoniae using PCR].

For the determination of the apx toxin genes in Actinobacillus pleuropneumoniae strains, five PCR reactions were developed which allow the detection of the activator and structural genes and the secretion genes of the toxins ApxI, ApxII and ApxIII. The oligonucleotide primers were chosen in order to amplify characteristic parts of the activator and structural genes apxICA, apxIICA and apxIIICA, and the secretion genes apxIBD and apxIIIBD. The annealing temperature of all five reaction was identical in order to allow the five reactions in a single PCR run. The differences in length between the individual amplified gene fragments allowed all product fragments to be separated in a single electrophoresis. This way, a typical toxin gene pattern could be obtained which is characteristic for the five toxin gene groups of A. pleuropneumoniae including serotypes 1, 5a, 5b, 9 and 11 (group 1), serotypes 2, 4, 6 and 8 (group 2), serotype 3 (group 3), serotypes 7 and 12 (group 4), and serotype 10 (group 5). The identification of the toxin genes, which have significance in virulence, enhance and facilitate differentiation of A. pleuropneumoniae and allow the detection of serotypes with an atypical toxin pattern.

Actinobacillus pleuropneumoniae↗
PubMed1995

[Treatment of primary hyperhidrosis of the upper limbs by transthoracic endoscopic sympathectomy].

Primary hyperhidrosis of the upper limbs has an important impact on the subject's social and psycho-affective equilibrium. These patients have two main problems. First physicians are not sufficiently aware of the therapeutic possibilities and secondly the generally poor reputation of surgery in this indication. Transthoracic endoscopic sympathectomy has completely changed the treatment of hyperhidrosis of the upper limbs. It is now considered to be the reference treatment in severe cases. The surgical procedure is simple and allows simultaneous treatment of both sides. There is no mortality and morbidity is extremely low quantitatively and of little consequence qualitatively. The therapeutic protocol is short and immediate and long-term results are excellent in 98 to 100% of the patients.

Arm↗