Background: Campylobacter jejuni can cause a spectrum of diseases in humans, ranging from enteritis and diarrhoea to severe inflammation, profuse bloody diarrhoea and chronic relapsing infection. Norepinephrine (NE) levels in the intestine increase under conditions of stress and trauma, and are thought to result in spill over of NE into the intestinal lumen. NE is known to stimulate the growth of a range of bacterial species, and to increase the pathogenicity of Escherichia coli. Aim: To determine the effects of NE on the pathogenic potential of C jejuni in a model system. Methods: C jejuni was grown in iron-replete and iron-limited media in the presence and absence of 100 mM NE. Several virulence-associated characteristics, including motility and cell invasion, were measured. Results: When C jejuni was grown in iron-limited media in the presence of NE, growth rate, motility and invasion of cultured epithelial cells were increased compared with cultures grown in the absence of NE. Bacteria exposed to NE during growth also caused greater subsequent disruption of cultured epithelial cell monolayers, inducing widespread breakdown of tight junctions. Conclusion: Exposure to NE causes an increase in the virulence-associated properties of Campylobacter. Stress and concomitant infection could therefore be contributory factors to the variable presentation of this disease.

Fourteen (20.9%) of 67 horses with a positive bacterial culture from synovial fluid were subjected to euthanasia because of persistent synovial sepsis compared to 2 (1.44%) of 139 with negative bacterial cultures (P<0.001). Overall survival and successful long-term return to function in horses with a positive bacterial culture was 50% (24/48 horses) compared to 70.5% (74/105) in culture negative horses (P=0.01). In horses that survived to be discharged, successful long-term return to function was not significantly different between culture positive and culture negative groups. Growth of Staphylococcus aureus from synovial fluid did not affect short-term survival to discharge from the hospital compared to other positive bacterial culture; however, successful long-term return to function was only 30.4% (4/13) in horses from which S. aureus was cultured compared to 73.9% (17/23) of horses in which other bacteria were cultured (P=0.015). CONCLUSIONS AND POTENTIAL CLINICAL RELEVANCE: Horses with a positive bacterial culture from a septic synovitis have a poorer prognosis for survival to discharge from hospital and overall long-term return to function than horses that yielded no bacterial growth. When S. aureus was cultured, the long-term prognosis was poorer.

Nonsteroidal anti-inflammatory drug choice did not affect major clinical outcomes in horses with SSI lesions but had some effects on signs of pain. This study provides no evidence to recommend one NSAID treatment above another based on survival or the incidence of ileus; however, evaluation of a larger number of cases is required.

Summary.A restriction fragment length polymorphism (RFLP) typing method for Legionella pneumophila serogroup 1 was developed. The method depended upon the use of cloned EcoRl fragments from L. pneumophila (Knoxville-1) probing Neil restriction fragments of chromosomal DNA. Examination of strains of L. pneumophila which were apparently unrelated showed that inter-strain RFLPs were common, and these formed the basis of the typing scheme. The technique was found to be highly reproducible and discriminatory. When the RFLP data were compared to that obtained by monoclonal antibody (MAb) subgrouping both methods of strain differentiation gave consistent results. The isolates examined by either method were also sub-divided by the alternative technique. The analysis of RFLPs by cloned probes should be of considerable epidemiological value.

The enzyme linked immunosorbent assay (ELISA) described was developed to detect a soluble antigen in the urine of

Summary. Strains of Listeria monocytogenes from 475 cases of human listeriosis collected during [1967][1968][1969][1970][1971][1972][1973][1974][1975][1976][1977][1978][1979][1980][1981][1982][1983][1984], belonged to one of three serogroups (1/2,3 or 4). They were phage typed with a set of 28 phages to investigate three aspects of the epidemiology of listeriosis. (i) Three patients each had two episodes of listeriosis, 3 months to 2 years apart, with strains of the same serogroup and indistinguishable by phage typing.(ii) Ten episodes of possible cross-infection between pairs of neonates in the same hospital occurred; the first baby was ill at or within 1 day of birth, and the second baby became ill 8-12 days after contact with the first. In each pair the L. monocytogenes strains were of the same serogroup and indistinguishable by phage typing. (iii) In three clusters of cases there may have been a common source of infection. L. monocytogenes strains from 10 of 1 1 cases of listeriosis in the Carlisle area in Ju1.-Dec. 198 1 were of the same serogroup; nine strains were non-phage-typable. The second cluster involved four adults treated at one hospital and the third a pair of neonates who were ill shortly after birth. In each cluster, strains were of the same serogroup, and were indistinguishable by phage typing. These last two clusters occurred during a short period when an unusually high proportion of strains from all cases of human listeriosis in Britain were indistinguishable by phage typing from the cluster strains, suggesting the possibility of common source infection.

A cloned EcoRI fragment from Legionella pneumophila, which includes 16s and 23s rRNA genes, was used to identify bacteria belonging to the genus Legionella by hybridization to a series of species specific restriction fragments. Examination of the type strains of 28 species of legionellae gave different band patterns in every case. When further isolates of these species were tested the patterns obtained were usually either identical, or very similar, to those of the respective type strains. Thirty-one coded isolates were examined and of these 29 were allocated to the correct species. The remaining strains (a non-Legionella and a L. pneumophila) could not be identified using this technique. The rRNA gene probe method should be of great value in the identification of legionellae, particularly for those species which are at present very difficult to distinguish serologically.

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