Excess glutamate in the cerebrospinal fluid in bacterial meningitis

We investigated possible neurotoxic components in the cerebrospinal fluid (CSF) of patients with bacterial meningitis. On murine cerebellar neuronal cell cultures, CSF exerted a dose-dependent toxic effect, which was attenuated by the NMDA receptor antagonist MK-801. Glutamate concentrations in the CSF of patients with bacterial meningitis were measured by an enzymatic assay and found to be significantly elevated (p < 0.001) as compared to viral meningitis and non-inflammatory neurological diseases. The concentration of glutamate in the CSF of patients with bacterial meningitis varied considerably and correlated with the severity of the disease as scored by the Glasgow Coma Scale. Cells in the CSF, mainly comprising polymorphonuclear granulocytes, did not release any glutamate into the culture medium, whereas blood monocytes produced remarkable amounts. These findings implicate an important role of monocytic inflammatory cells in bacterial meningitis by the release of glutamate, which may contribute to neuronal cell death.

Tick infestation patterns and prevalence of Borrelia burgdorferi in ticks collected at a veterinary clinic in Germany

A total of 4803 domestic and wild animals which were presented for examination at a veterinary clinic in north Baden, Germany over a period of 1 year were examined for tick infestation. A total of 434 nymphal and adult ticks were collected from 175 hosts. Ticks found belonged to the species Ixodes ricinus (385), Ixodes hexagonus (48), and Ixodes ventalloi (one). The polymerase chain reaction was used to examine 132 I. ricinus and 21 I. hexagonus for the presence of Borrelia burgdorferi. Twenty-two per cent of adult I. ricinus were infected as were one female and one larval I. hexagonus.

Reassessment of the phylogenetic position of the bacterium associated with Whipple's disease and determination of the 16S-23S ribosomal intergenic spacer sequence

Whipple's disease is a rare chronic illness associated with an unculturable bacterium that is constantly present in affected tissues. This bacterium was previously characterized at the molecular level by PCR and sequencing of the 16S rRNA gene. On the basis of 1,321 nucleotides of the sequence of its gene coding for 16S rRNA (16S rDNA), a phylogenetic relationship to the actinomycetes was established. In this study, we determined an almost complete 16S rDNA sequence (1,495 nucleotides), the 16S-23S ribosomal intergenic spacer sequence, and 200 nucleotides of the 23S rRNA gene. The 16S rDNA sequence was compared with the large number of actinomycete sequences that have been added to the database since the original study. Phylogenetic analysis revealed a branching position as the deepest branch of the cluster comprising the actinomycetes with group B peptidoglycan between this group and the family Cellulomonadaceae. This provides additional information on the phylogenetic position of this bacterium and some clues as to its characteristics. The spacer region between the 16S and 23S rRNA genes is 294 nucleotides long and does not contain tRNA genes. As has been shown in other instances, the increased variability of the ribosomal intergenic spacer compared with the 16S rRNA gene makes it a potential target for use in the differentiation of strains of the bacterium associated with Whipple's disease.

Evaluation of a new version of the EnviroAmp Legionella kit for the detection of legionellae in water samples by the polymerase chain reaction

The detection of Legionella sp. in various types of environmental water samples was evaluated using a revised version of the EnviroAmp Legionella kit (Perkin-Elmer), which is based on the polymerase chain reaction (PCR). The new kit employs a modified protocol for the pretreatment of water samples, which is designed to further reduce the inhibitory action of some samples to the PCR. The results of the new kit were compared with those of culture. Seventy-four water samples were examined. Of these samples, 51 were taken from hospital water systems, 16 were household water samples, 5 were from surface water, and 2 were rain water. These samples were examined both by PCR and by culture on MWY Legionella selective agar. Of the 74 samples, 46 (62%) were positive by both test systems. Twenty-five samples (34%) were positive by PCR, but negative by culture. While 3 samples (4%) were negative by both test methods, no sample was negative by PCR and positive by culture. Statistical analysis revealed high positive predictive values of PCR, when L. pneumophila was detected or when the genus Legionella was detected at high intensity. Negative predictive values were high, when the PCR was negative or only weakly positive for the genus Legionella.

Diagnostic application of a polymerase chain reaction assay for the Whipple's disease bacterium to intestinal biopsies

BACKGROUND & AIMS

The uncultured Whipple's disease bacterium (Tropheryma whippelii) was characterized in 1991-1992 by polymerase chain reaction (PCR) and sequencing of the bacterial 16S ribosomal RNA gene. The aim of this study was to develop a PCR assay for diagnostic purposes.

METHODS

Modified primers for PCR and a specific probe for hybridization were designed. The specificity of this PCR assay was tested using 37 bacterial control strains and intestinal biopsy samples from 16 patients without Whipple's disease. The sensitivity was tested in 88 intestinal biopsy samples from 35 patients with Whipple's disease.

RESULTS

PCR and hybridization were negative in all 37 bacterial controls and in all 16 patients without Whipple's disease. Before therapy, DNA of T. whippelii was detected in all 30 patients with Whipple's disease from whom formalin-fixed biopsy material was available, whereas Bouin-fixed material was negative. During and after treatment, PCR was negative in 23 of the 24 patients who were followed up. Generally, conversion to negative occurred within 1 year. Despite negative intestinal PCR, symptomatic cerebral Whipple's disease appeared in 3 patients.

CONCLUSIONS

This PCR assay is specific and sensitive and is applicable as a diagnostic test. However, PCR from intestinal biopsy samples seems less helpful for monitoring the effect of treatment.

Comparison of urinary bladder and ear biopsy samples for determining prevalence of Borrelia burgdorferi in rodents in central Europe

PCR was used to compare urinary bladder and ear biopsy samples from four European species of wild rodents for the presence of Borrelia burgdorferi sensu lato. From 60 paired comparisons of bladder and ear biopsy samples, the PCR results were concordantly positive or negative in 43 samples (71.7%). Of the 17 which differed, 14 bladder samples were positive and ear samples were negative while the converse occurred for three samples. Thus ear biopsy samples led to a significantly lower estimate of infection than bladder biopsy samples. This suggests that the use of ear biopsy samples in epidemiological studies of B. burgdorferi in Central European rodents is likely to lead to underestimates of the prevalence.

Patient assessment of self-measurement of blood pressure: results of a telephone survey in Germany

OBJECTIVE

To obtain information on the adoption of self-measurement of blood pressure by hypertensives and their attending physicians.

METHODS

Callers to the Cardiovascular Hotline Heidelberg revealing themselves to have high blood pressure were interviewed about self-recording of blood pressure.

RESULTS

Among the callers about 70% practised self-measurement. Half of them bought a device on their own initiative, one-third on recommendation or prescription by their physician. A quarter of those practising the technique were introduced to it by experienced personnel and a comparable number were adequately informed about the aims and objectives. Nevertheless, more than half of those practising self-measurement claimed to be coping better with the disease.

CONCLUSIONS

The data indicate that self-monitoring is widely practised by hypertensives in Germany. In contrast to this finding, too few physicians have adopted home-recording as a useful tool in the treatment of hypertension.

Universal fungus-specific primer systems and group-specific hybridization oligonucleotides for 18S rDNA

We designed two primer systems that amplify a fragment of the gene coding for the small ribosomal subunit (18S rRNA). A broadly reactive, yet fungus-specific, primer cocktail comprises two previously published primers, TR1 and TR2, which specifically amplify dermatophytes, and two newly designed primers, CA1 and AF2, which specifically amplify Candida and Aspergillus respectively. This primer cocktail amplifies a DNA fragment of approximately 578 basepairs (bp) in length (from position 838 to 1415), which contains variable, possibly species-specific regions (V5, partly V7). Another newly designed primer, UF1 (universal fungal primer 1), along with the eukaryotic primer S3 amplifies a 926-bp fragment (from position 263 to 1188) that includes the variable regions V3, V4 and V5. Both primer systems amplified DNA from Saccharomyces cerevisiae, Candida albicans, Cryptococcus neoformans, Aspergillus fumigatus, Penicillium marneffei, Fusarium oxysporum and Trichophyton mentagrophytes, but not the DNA from Prototheca zopfii, Escherichia coli or humans. The previously published oligonucleotides TR and HC, which are specific for dermatophytes and Histoplasma respectively, and the newly designed group-specific oligonucleotides, CA and AF, hybridized with T. mentagrophytes, Histoplasma capsulatum, C. albicans and A. fumigatus respectively, but not with the other six fungi or with the three controls.

Impact of urbanization on detection rates of eating disorders

OBJECTIVE

The purpose of this study was to examine the incidence of anorexia nervosa and bulimia nervosa among patients in primary care and to evaluate the impact of urbanization, age and sex differences, and changes over time.

METHOD

During 1985-1989, 58 general practitioners, trained in diagnosing eating disorders, registered all of their patients who had diagnoses of anorexia nervosa and/or bulimia nervosa according to strict criteria. The study population (N = 151,781) was 1% of the population of the Netherlands; the distribution of sexes, ages, geographical locations, and degrees of urbanization in the study group was representative of the Dutch population. Main outcome measures were rates of newly detected cases and age-adjusted rate ratios.

RESULTS

The crude annual incidence rate of detected cases in primary care per 100,000 person-years was 8.1 for anorexia nervosa and 11.5 for bulimia nervosa. The incidence of bulimia nervosa was lowest in rural areas, intermediate in urbanized areas, and highest in large cities (6.6, 19.9, and 37.9, respectively, per 100,000 females per year); no rural-urban differences for anorexia nervosa were found. Pronounced sex and age differences in incidence rates were observed. Over the 5-year period, there was no time trend in the incidence of anorexia nervosa, but the incidence of bulimia nervosa tended to increase.

CONCLUSIONS

The incidence rates of eating disorders--as defined by detection rates in primary care--are higher than previously reported. Urbanization seems to be a risk factor for bulimia nervosa but not for anorexia nervosa.

[Natural epidemiology of Lyme borreliosis with reference to clustered incidence of illnesses in the suburbs of a North Baden community]

Human infection with Borrelia burgdorferi, the causative agent of Lyme disease, is unusually common in the "Scheelkopf" area of the town Bruchsal in north Baden (Germany), a situation which has led to considerable publicity and public concern. This study was carried out in order to clarify this situation by determining the prevalence of B. burgdorferi in both the free-living tick populations (Ixodes ricinus) and the rodent population from the "Scheelkopf" as well as from surrounding control areas. The polymerase chain reaction (PCR) was used to determine the presence of infection in whole tick preparations and in mouse bladders. The prevalence of B. burgdorferi in freeland ticks ranged from 19% to 44% and in mice from 6% to 29% depending on the area studied. The "Scheelkopf", with prevalences for ticks and mice of 33% and 10% respectively, was not significantly different from the control areas. Our results indicate that there is a high risk of human infection throughout the study area. This is probably related to the intensive use of the area for gardens and the related recreational behaviour of the human population in conjunction with the high rate of infection prevailing in I. ricinus.

DNA polymorphisms in strains of Legionella pneumophila serogroups 3 and 4 detected by macrorestriction analysis and their use for epidemiological investigation of nosocomial legionellosis

Genomic DNAs of clinical and environmental isolates of Legionella pneumophila belonging to serogroups 3 and 4 were analyzed by macrorestriction analysis by pulsed-field gel electrophoresis. The restriction enzymes SfiI and NotI allowed easy visual separation of epidemiologically unrelated serogroup 3 strains. Three unrelated serogroup 3 strains that were isolated from different locations were identical by this genome mapping technique. Five unrelated serogroup 4 strains were separable by this technique. The electrophoretic patterns obtained after SfiI or NotI cleavage of the DNA of strains isolated from four patients with hospital-acquired legionellosis were identical to the patterns of strains isolated from the hot water supply systems of the buildings in which the patients were hospitalized. In conclusion, macrorestriction analysis is a valuable tool for epidemiological studies of infections caused by L. pneumophila serogroups 3 and 4.

Evaluation of the detection of Borrelia burgdorferi DNA in urine samples by polymerase chain reaction

It is difficult in some cases to identify an infection caused by Borrelia burgdorferi and to monitor the effect of therapy. Seropositivity will persist even after successful treatment and therefore may suggest ongoing infection. For direct detection of B. burgdorferi DNA in human urine samples, the polymerase chain reaction (PCR) was evaluated. A published primer system was selected, which amplifies a 259 bp fragment from the gene encoding the 23S rRNA. The lower detection limit of the primer system was 10 fg of extracted B. burgdorferi DNA. Several methods for the pretreatment of urine samples were tested. Of these, the Geneclean kit (Bio 101, USA) showed the best results. A total of 114 urine samples from 74 patients belonging to three clinical groups was investigated: (i) 51 samples from 26 patients with active Lyme disease, (ii) 36 samples from 27 patients with previous infection but no symptoms at the time the urine was collected, and (iii) 27 samples from 21 seronegative control patients without Lyme disease. B. burgdorferi DNA was detected in 25 urine samples of 17 patients with active disease, whereas 26 samples from this group of patients were negative. Only one asymptomatic case with previous infection showed a positive result, and the urine samples of the patients without Lyme disease were uniformly negative. Two of four patients from whom samples before and directly after onset of therapy were available converted from negative to positive PCR results after initiation of therapy, accompanied by the symptoms of a Jarisch-Herxheimer reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of Tropheryma whippelii DNA in a patient with AIDS

A case of an AIDS patient infected with the Whipple's disease bacterium, Tropheryma whippelii, is reported. A DNA fragment with sequence specificity for the 16S rRNA gene of the bacterium was detected by PCR in a duodenal biopsy specimen from a 55-year-old male patient with AIDS and diarrhea. The biopsy specimen contained periodic acid-Schiff stain-positive macrophages which did not, however, resemble the sickleform-particle-containing cells characteristic of Whipple's disease. This observation raises two possibilities: either the patient had a coincidence of AIDS and Whipple's disease or Tropheryma whippelii acted as an opportunistic pathogen in this immunodeficient patient. The latter explanation is of interest in light of the ongoing discussion of immunologic abnormalities as predisposing factors for Whipple's disease.

Recent infection as a risk factor for cerebrovascular ischemia

BACKGROUND AND PURPOSE

Previous infection is discussed as a risk factor for ischemic stroke in children and younger adults. We tested the hypothesis that the role of recent infection in cerebrovascular ischemia is not restricted to younger patients and investigated which infections are mainly relevant in this respect.

METHODS

We performed a case-control study with 197 patients aged 18 to 80 years with acute cerebrovascular ischemia and 197 randomly selected control subjects matched for sex, age, and area of residence.

RESULTS

Infection within 1 week before ictus or examination was significantly more common among patients (38 of 197) than control subjects (10 of 197; odds ratio [OR], 4.5; 95% confidence interval [CI], 2.1 to 9.7). Patients more often had febrile and subfebrile infections (> or = 37.5 degrees C) than control subjects (29 of 197 versus 5 of 197; OR, 7.0; 95% CI, 2.5 to 20). Respiratory tract infections were most common in both groups. Bacterial infections dominated among patients but not among control subjects. Infection increased the risk for cerebrovascular ischemia in all age groups; this reached significance for patients aged 51 to 60 and 61 to 70 years. The profile of vascular risk factors was similar in patients with and patients without previous infection. Infection remained a significant risk factor when previous stroke, hypertension, diabetes mellitus, coronary heart disease, and current smoking were included as covariates in a logistic model (OR, 4.6; 95% CI, 1.9 to 11.3).

CONCLUSIONS

Recent infection, primarily of bacterial origin, may be a risk factor for cerebrovascular ischemia in older as well as younger patients.

Detection of Legionella DNA in human and guinea pig urine samples by the polymerase chain reaction

A detection system for Legionella DNA in urine samples based on the polymerase chain reaction (PCR) was developed and tested on infected guinea pigs and patients suffering from pneumonia. Results were compared with standard methods for diagnosis of Legionnaires' disease. A primer system was selected which amplifies a 108 bp DNA fragment of the 5S rRNA gene. The sensitivity of the PCR system was one femtogram of extracted Legionella DNA. Three methods were tested for pretreatment of urine samples. Of these, the Geneclean II kit (Bio 101, USA) gave the best results for artificially contaminated urine samples as well as those from infected guinea pigs or patients. Thirty-seven urine samples from 15 guinea pigs intraperitoneally infected with either Legionella pneumophila serogroup 1, 3 and 6 or Legionella micdadei, 26 urine samples of 21 patients suffering from pneumonia, and 30 control samples of patients with urinary tract infection (UTI) were tested. Legionella DNA was detected in 29 of the guinea pig urine samples; whereas, urinary antigen detection using EIA was positive in only 20 of the samples. PCR was also positive in the samples of 11 patients with pneumonia, 9 of which were confirmed by other microbiological methods, such as culture, direct fluorescent antibody test, urinary antigen detection and antibody testing. However, of the 30 control samples from patients with UTI, three samples yielded positive results. The results demonstrate that Legionella DNA is excreted in the urine of infected individuals and that the PCR shows a higher degree of sensitivity than EIA to the detection of soluble Legionella antigen in urine.(ABSTRACT TRUNCATED AT 250 WORDS)

[Self-measurement of blood pressure in hypertensive subjects in Germany. Results of a questionnaire in Spring/early Summer 1993]

The 'cardiovascular hotline' in Heidelberg, established in April 1992, provides data concerning the self-measurement of blood pressure. For this purpose 277 hypertensives were asked from 15 April to 15 July 1993. 195 (70%) of those questioned (47% men, 53% women) practised home-recording, but only 17% on recommendation of their physician. Only 22% were introduced to the technique by experienced personnel; just 50% were adequately controlled. At least 35% of hypertensives used an oscillometric device and not more than 10% an auscultation device. 5 to 14% of the patients reported to have difficulties in handling their device. Approximately 60% of the patients practicing home-recording stated that this method enabled them to cope better with their disease. Compared with the 1987 pilot study in the Hamburg area, this percentage did not increase; however, it could be confirmed that only approximately 10% of the patients are unsuited for home-recording. 75% of the hypertensives measuring their own blood pressure documented their values, but in only 47% of all cases physicians drew conclusions from the data. 31% of the patients were unable to say whether their medication was adjusted on the basis of self-measured blood pressure values. In conclusion, many hypertensives practice self-measurement of blood pressure. Despite this fact, home-readings are not yet sufficiently accepted by physicians as a possible and desirable method to optimize high blood pressure treatment. This situation should be improved since compliance of physicians is the basis for a better education of hypertensive patients, thus optimizing patient compliance.

[Lyme borreliosis--an infectious disease with interdisciplinary demands]

Lyme borreliosis is an infectious disease with various clinical manifestations, caused by the bacterium Borrelia burgdorferi. Although symptoms of the disease have been described since more than 100 years ago, it was not until 1982 that the causative organism was discovered. In Europe, Lyme borreliosis is the most common tick-borne disease, and in endemic regions, a considerable number of clinical cases can be found. The course of the disease is in stages and involves various organ systems, such as skin, nervous system, heart, and joints. Laboratory diagnosis is considered to be difficult and relies mainly on the determination of antibodies. A vaccine for use in humans is not yet available, but experimental data support the feasibility of a vaccine development.

[Reinfection with Borrelia burgdorferi in an immunocompetent patient]

A 54-year-old patient with an intact immune system developed Lyme disease three times within 4 years. The first time an erythema migrans occurred, which was successfully treated with oral doxycycline (100 mg twice daily for 20 days). Specific antibodies were subsequently demonstrated. Re-infection nonetheless occurred a year later, again as erythema migrans. Oral doxycycline in higher dosage (three times 100 mg daily for 20 days) failed to prevent generalization of the infection with rigor, head and neck aches, myalgia, fatigue and subfebrile temperatures. There was a marked increase in Borrelia-specific antibody titre. Parenteral treatment with cefotaxime (twice daily 3 g for 12 days) was curative. But 2 years later yet another re-infection occurred with classic erythema migrans, which regressed under doxycycline. The course of the disease in this case demonstrates that Borrelia-specific antibodies do not always protect against re-infection. This may have consequences for the possible development of a vaccine.

Comparison of polymerase chain reaction and conventional culture for the detection of legionellas in hospital water samples

A detection system for Legionella spp. based on the polymerase chain reaction (PCR) was used to assess the diagnostic value of PCR for the surveillance of contamination of man-made water systems by legionellas. A previously-published primer system was chosen to amplify a fragment of the 5S-ribosomal gene of Legionella spp. A total of 78 water samples from various sources were examined by PCR and culture on MWY Legionella selective agar. Fifty-seven of 78 water samples were positive by both test systems (73%), nine were positive by PCR only (11.5%), another nine were positive by culture but negative by PCR (11.5%), and three were negative by both techniques (3.8%). The PCR was inhibited when large amounts of rust were present in the samples. Culture failed to detect legionellas in samples that contained large numbers of other bacteria capable of overgrowing the legionellas. These results show that PCR is a rapid and sensitive technique for the detection of legionella contamination in water samples and that PCR and culture complement each other in monitoring of environmental water samples.