Pan-European study on culture-proven Legionnaires' disease: distribution of Legionella pneumophila serogroups and monoclonal subgroups.

This pan-European study included unrelated strains of Legionella pneumophila obtained from 1335 cases of Legionnaires' disease. The isolates were serotyped into the serogroups 1 to 15 by monoclonal antibodies (MAb) and/or rabbit antisera. Additionally, MAb subgrouping was undertaken for isolates belonging to serogroups 1, 4, and 5. Monoclonal types of serogroup 1 were subdivided as having, or not having, the virulence-associated epitope recognized by the MAb 3/1 (Dresden Panel). This epitope is not present on strains belonging to any other serogroups. Taking all Legionella incidents together, MAb 3/1-positive cases were most frequent (66.8%); 11.7% of the isolates belonged to MAb 3/1-negative serogroup 1 subgroups and 21.5% to other serogroups, with serogroups 3 and 6 predominating. Among all serotypes discriminated in this study, monoclonal subtype Philadelphia was the most frequent. If categories of infection were considered, the proportion of MAb 3/1-negative strains differed significantly ( P<0.0005) between community-acquired cases (139/510; 27.3%) and travel-associated (42/295; 14.2%) or hospital-acquired infections (176/329; 53.5%). Moreover, taking distribution in different European areas into account, the proportion of MAb 3/1-negative strains was significantly higher in the Scandinavian region than in the Mediterranean countries or the UK for both community-acquired (48.7% vs. 18.6% or 12.0%; P<0.0005) and nosocomial cases (87.7% vs. 32.6% or 52.6%; P

Designation of the European Working Group on Legionella Infection (EWGLI) amplified fragment length polymorphism types of Legionella pneumophila serogroup 1 and results of intercentre proficiency testing Using a standard protocol.

The utility of amplified fragment length polymorphism (AFLP) analysis as a genotyping method for the epidemiological typing of Legionella pneumophila serogroup 1 has been previously demonstrated. This study (i). reports recommendations for the designation of the European Working Group on Legionella Infections (EWGLI) AFLP types, (ii). describes the EWGLI AFLP types identified for the 130 strains in the EWGLI culture collection, and (iii). reports the results of a newly introduced international programme of proficiency testing. Following preliminary analysis of 20 epidemiologically unrelated isolates, 16 major AFLP types were identified. A coded proficiency panel, comprising 12 additional isolates representing 9 of these 16 AFLP types, was sent to 17 centres in 14 European countries where it was analysed following a previously determined standard protocol. The identity of each coded strain (recorded as AFLP type 001-016 or untypeable) was determined by participants with reference to these 16 AFLP types, either visually or using gel analysis software where available, and reported to the coordinating centre. Nine of the 12 strains, including an epidemiologically related pair and two pairs of unrelated isolates of the same type, were correctly identified to the correct AFLP type by all or all but one of the participants. Seven laboratories correctly identified all 12 isolates, and a further seven laboratories correctly identified 11. Type identification scores ranged from 75% (1 centre), 83% (2 centres), and 92% (7 centres) to 100% (7 centres). The AFLP method as described is robust and rapid and allows the genotypic comparison of isolates of Legionella pneumophila between different testing centres without the need for exchange of the strains studied.

Isolation of antibacteriologically active compounds from species of the Cottidae family.

Antibacteriologically active compounds were isolated from the skin of several species of the fish family Cottidae. Suitable samples were obtained from species living in the Pacific, lakes in North America and the Fenno-Scandinavian peninsula as well as the Baltic sea. The compounds isolated from the skin of Triglops quadricornis (fourhorn sculpin) from the Baltic sea were particularly studied. The activity was partially characterised by chemical and biochemical investigations and the susceptibility of several human and fish pathogens described. The substance or substance(s) are of a high molecular mass, resist proteolytic and glycolytic enzymes, are heat and pH sensitive and water soluble.

Assessment of intercentre reproducibility and epidemiological concordance of Legionella pneumophila serogroup 1 genotyping by amplified fragment length polymorphism analysis.

The aims of this work were to assess (i) the intercentre reproducibility and epidemiological concordance of amplified fragment length polymorphism analysis for epidemiological typing of Legionella pneumophila serogroup 1, and (ii) the suitability of the method for standardisation and implementation by members of the European Working Group on Legionella Infections. Fifty coded isolates comprising two panels of well-characterised strains, a "reproducibility" panel (n=20) and an "epidemiologically related" panel (n=30), were sent to 13 centres in 12 European countries. Analysis was undertaken in each centre following a previously determined standard protocol. Results were analysed by the participants, using gel analysis software where available, and submitted to the coordinating centre. The coordinating centre reanalysed all results visually and selected data-sets with gel analysis software. Data analysis by participants yielded reproducibility (R) values of 0.20-1.00 and epidemiological concordance (E) values of 0.11-1.00, with 6 to 34 types. Following visual analysis by the coordinating centre, R=0.78-1.00, and E=0.67-1.00, with 10-20 types. Analysis of three data-sets by the coordinating centre using gel analysis software yielded R=1.00 and E=1.00, with 12, 13 or 14 types. This method can be used as a simple, rapid screening tool for epidemiological typing of isolates of Legionella pneumophila serogroup 1. Results demonstrate that the method can be highly reproducible (R=1.00) and epidemiologically concordant (E=1.00), with good discrimination. The electropherograms generated are amenable to computer-aided analysis, but strict adherence to a previously defined laboratory protocol is required. Following designation of representative type strains and patterns, this method will be adopted by the European Working Group on Legionella Infections as the first internationally standardised typing method for use in the investigation of travel-associated Legionella infections.

[Human parasites and amoeba: lower warm-water temperature is favourable to Legionella bacteria]. / Parasit hos människa och amöba: sänkt varmvattentemperatur gynnar legionellabakterierna.

Our knowledge of Legionella bacteria has increased since their discovery in 1977. Legionnaires' disease is an underestimated diagnosis in Sweden. Most cases are community acquired and probably due to the presence of legionella bacteria in the water distribution systems of buildings, though the precise source of infection often remains unknown. Although a number of putative virulence factors have been identified, to date few of them have been shown to be significant. The replication of legionella in human macrophages is similar to that in protozoa. Their interaction with protozoa might explain certain features of their ecology and virulence, and shed light on peculiarities in the transmission of infection. The urinary antigen assay has greatly facilitated the diagnosis of legionellosis, and methods based on the amplification of specific DNA sequences will probably become increasingly important, but isolation of the organism will still be justified. Traditional erythromycin therapy is likely to be replaced by treatment with new antimicrobials.

Virulence and colonization-associated properties of Helicobacter pylori isolated from children and adolescents.

Helicobacter pylori isolates from 32 children and adolescents were characterized with respect to putative virulence and colonization-associated properties. Only 3 of the subjects had duodenal ulcer. All but 2 of the remaining 29 had various degrees of chronic gastric inflammation. No significant correlation between degree of inflammation and presence of the cag-pathogenicity island, cytotoxin production, vacA alleles associated with cytotoxin expression, and binding ability to the Lewis(b) (Le[b]) oligosaccharide was found. Only 4 isolates expressed the Le(b)-specific adhesin, of which 3 were also cag region-positive. This is in contrast to adults with gastritis or peptic ulcer disease (or both), in whom most of the H. pylori isolates bind Le(b). In an in situ binding assay H. pylori were less able to adhere to gastric surface mucous cells in biopsies taken from children compared with adults, suggesting a lower expression of the Le(b) oligosaccharide in the children.

Legionella urinary antigen in early disease.

The results of Legionella urinary antigen testing were correlated to the interval between onset of disease and sampling of urine in 134 patients in connection with a large outbreak of Legionnaires' disease at a Swedish hospital. In 17 patients with the disease, 5/7 sampled during the first 5 days of illness proved negative in the urinary antigen test. The risk of obtaining negative results during the first days of the disease is emphasized.

Absence of Helicobacter pylori in dental plaques in Helicobacter pylori positive dyspeptic patients.

To test the validity of reports on detection of Helicobacter pylori in the mouth, samples were obtained simultaneously from the gastric mucosa and dental plaques for culture in 94 patients examined consecutively by endoscopy. Histological examinations and serological tests were also performed. Helicobacter pylori was not found in the mouth of any of the patients including 52 who had culture-positive gastric biopsies. Thus earlier results could not be confirmed, however, other techniques such as the polymerase chain reaction might give different results.

Erythromycin in the treatment of pertussis: a study of bacteriologic and clinical effects.

In an open randomized study 17 patients with a positive culture for Bordetella pertussis were treated for 10 days with erythromycin (50 mg/kg/day divided in 2 doses). The bacterium could not be isolated during therapy and in only one patient was it isolated 5 days after cessation of treatment. In comparison B. pertussis was isolated 10 and 15 days after diagnosis from 10 and 4 patients, respectively, of a group of 21 untreated controls. The treated group developed significantly fewer whoops than did the control group, even though most of the individuals had reached the paroxysmal stage at diagnosis. The dose of erythromycin (ethylsuccinate and stearate preparations) gave serum concentrations about 100 times larger than the minimal inhibitory concentration of isolated bacteria and was well-tolerated. Thus adequate erythromycin treatment eliminates B. pertussis from the nasopharynx and reduces symptoms in patients having a history of pertussis of less than 14 days. Adequate dosage and length of treatment might be crucial for these results.

In vitro aminoglycoside resistance of gram-negative bacilli and staphylococci isolated from blood in Sweden 1980-1984.

The in vitro susceptibility to gentamicin, tobramycin, amikacin and netilmicin in septicaemia isolates was followed during 1980-1984 in 6-8 Swedish laboratories. The bacterial distribution was similar over the years and was dominated by Escherichia coli and staphylococci. Resistance to gentamicin was found in 2.3-3.6%, to tobramycin in 1.4-3.4%, to amikacin and netilmicin in 0.5-0.9%. Production of aminoglycoside modifying enzymes was observed among resistant strains.

Autoimmune thyroid dysfunction in the postpartum period.

The prevalence of thyroid disease was investigated in 460 Caucasian women after delivery. Thyroid microsomal antibodies (MsAb) were found in 44 (9.6%) of the women. These women appeared to have autoimmune thyroiditis. The changes in MsAb titers followed a predictable pattern with maximal values around 5-7 months postpartum. At this time 20 of these women had transient hypothyroidism and in some this was preceded by a thyrotoxic episode. The extent of postpartum hypothyroidism correlated well with the titers of MsAb in early pregnancy and in the postpartum period. Transient thyrotoxicosis occurred in eight women 5-7 months postpartum. TSH-receptor stimulating antibodies and/or high radioiodine uptake, suggesting Graves' disease, were detected in four of these women. Thus, after delivery, manifestations of autoimmune thyroid disorders, are remarkably common. In patients with autoimmune thyroiditis measurements of MsAb provide a good prognostic marker for the development of transient hypothyroidism.

Comparison of metronidazole with doxycycline prophylaxis in elective colorectal surgery. A prospective, randomized multicentre study.

In a series of 157 patients undergoing elective colorectal surgery, metronidazole or doxycycline was given to prevent infectious complications. The prophylaxis was started just before the operation and was administered for a total of three days. Excluding mild, negligible infections, 39 (25%) of the 157 patients had infectious complications, 23 from the metronidazole group (28%) and 16 from the doxycycline group (21%). The type of infection varied according to the medication. In four cases of the metronidazole group and 16 of the doxycycline group, anaerobic bacteria were found. The corresponding figures for aerobes were 36 and 20. Doxycycline thus was significantly more effective in preventing complications in general, but metronidazole gave superior protection against anaerobes.

Antigenic similarities and differences in genus Pityrosporum.

Using the indirect immunofluorescence technique no differences were observed in intensity of staining when antisera against Pityrosporum orbiculare and P. ovale or IgG fractions of these were incubated with P. orbiculare and P. ovale cells. However, a weaker reaction was observed with these antisera and P. pachydermatis cells. With IgG fractions the nonspecific fluorescence was minimized. Fungal cells in biopsies from tinea versicolor lesions showed a brilliant staining with the IgG fractions of antisera against P. orbiculare. This investigation indicates a close antigenic relationship between all of the 3 Pityrosporum species. A common antigenicity was found between P. orbiculare and P. ovale cells as well as between P. orbiculare cells from culture and the fungal cells in biopsies from tinea versicolor lesions. This strongly suggests that these 2 species are identical with each other and with the organism found in tissue.

Micro-aerophilic and anaerobic growth of Pityrosporum species.

Pityrosporum orbiculare, P. ovale, and P. pachydermatis showed the same luxuriant growth when cultured under aerobic conditions, in an aerobic milieu with 7% CO2, and under micro-aerophilic conditions. The species survived and even multiplied under strictly anaerobic conditions. These findings may explain how P. orbiculare and P. ovale can survive in the deeper parts of hair follicles. On a medium that enhanced the production of filaments in Pityrosporum, filaments were more pronounced in the micro-aerophilic environment. Macroscopically, P. ovale showed a more luxuriant growth than P. orbiculare on this medium, but microscopically the same type of filaments were produced.