Advanced portable micro-SORS prototype coupled with SERDS for heritage science

We investigate the subsurface composition of turbid materials at the micro scale by means of a portable non-invasive technique, micro-spatially offset Raman spectroscopy (micro-SORS), combined with shifted excitation Raman difference spectroscopy (SERDS). This combination enables the microscale layer analysis and allows to deal effectively with highly fluorescing samples as well as ambient light, all in a form of an in-house portable prototype device optimised for applications in heritage science. The instrument comprises ability to simultaneously collect multiple spectra by means of an optical fibre bundle, thus reducing the dead time and simplifying the ease of deployment of the technique. The performance of the synergy between micro-SORS and 785 nm SERDS dual-wavelength diode laser is demonstrated on a stratified mock-up painting samples including highly fluorescing painted layers. This instrumental approach could be ground-breaking in heritage science, due to the largely unmet need of analysing the molecular composition of subsurface of artworks non-invasively and in situ, and in the presence of fluorescent background and ambient light. Moreover, many other fields are expected to benefit from this technological advancement such as solar energy, forensic and food analytical areas.

Invasive paediatric Elizabethkingia meningoseptica infections are best treated with a combination of piperacillin/tazobactam and trimethoprim/sulfamethoxazole or fluoroquinolone

Objectives

Elizabethkingia meningoseptica is a multi-drug-resistant organism that is associated with high mortality and morbidity in newborn and immunocompromised patients. This study aimed to identify the best antimicrobial therapy for treating this infection.

Methods

A retrospective descriptive study was conducted from 2010 to 2017 in a tertiary paediatric hospital in Singapore. Paediatric patients aged 0 to 18 years old with a positive culture for E. meningoseptica from any sterile site were identified from the hospital laboratory database. The data collected included clinical characteristics, antimicrobial susceptibility and treatment, and clinical outcomes.

Results

Thirteen cases were identified in this study. Combination therapy with piperacillin/tazobactam and trimethoprim/sulfamethoxazole or a fluoroquinolone resulted in a cure rate of 81.8  %. The mortality rate was 15.4  % and neurological morbidity in patients with bacteraemia and meningitis remained high (75 %).

Conclusions

Treatment with combination therapy of piperacillin/tazobactam and trimethoprim/sulfamethoxazole or a fluroquinolone was effective in this study, with low mortality rates being observed.

Quantitative NMR spectroscopy for gas analysis for production of primary reference gas mixtures

Due to its direct correlation to the number of spins within a sample quantitative NMR spectroscopy (qNMR) is a promising method with absolute comparison abilities in complex systems in technical, as well as metrological applications. Most of the samples studied with qNMR are in liquid state in diluted solutions, while gas-phase applications represent a rarely applied case. Commercially available NMR equipment was used for purity assessment of liquid and liquefied hydrocarbons serving as raw materials for production of primary reference gas standards. Additionally, gas-phase studies were performed within an online NMR flow probe, as well as in a high-pressure NMR setup to check feasibility as verification method for the composition of gas mixtures.

Single-pass UV generation at 222.5 nm based on high-power GaN external cavity diode laser

We demonstrate a compact system for single-pass frequency doubling of high-power GaN diode laser radiation. The deep UV laser light at 222.5 nm is generated in a β-BaB2O4 (BBO) crystal. A high-power GaN external cavity diode laser (ECDL) system in Littrow configuration with narrowband emission at 445 nm is used as pump source. At a pump power of 680 mW, a maximum UV power of 16 μW in continuous-wave operation at 222.5 nm is achieved. This concept enables a compact diode laser-based system emitting in the deep ultraviolet spectral range.

400 mW external cavity diode laser with narrowband emission at 445 nm

A high-power external cavity diode laser (ECDL) system with narrowband emission is presented. The system is based on a commercially available high-power GaN laser diode. For the ECDL, a maximum optical output power of 400 mW in continuous-wave operation with narrowband emission is achieved. Longitudinal mode selection is realized by using a surface diffraction grating in Littrow configuration. A spectral width of 20 pm at 445 nm with a side-mode suppression ratio larger than 40 dB is achieved. This concept enables diode laser systems suitable for subsequent nonlinear frequency conversion into the UV spectral range.

[MRSA bloodstream infections according to the German obligation for notification - data and experience of the MDRO Network Rhine-Main, Germany, 2011]

BACKGROUND

Since July 1st, 2009 in accord with the statuary order based on the German law for infectious diseases (Infektionsschutzgesetz), MRSA in blood and liquor have to be notified to the public health authorities. The aim of this extension of the notification to report is to improve the surveillance of nosocomial infections and the prevention of nosocomial MRSA infections. In this paper data of the notifications in the year 2011 within the MDRO-Net Rhine-Main, an association of 7 public health authorities in the region, are reported in order to investigate whether the aims of the obligation for notification could be achieved.

RESULTS

In 2011, 138 MRSA bloodstream infections, including 1 MRSA in liquor culture, were notified to the 7 health protection authorities, resulting in an incidence rate of 5.6/100,000 inhabitants. In urban regions with more hospitals available, the incidence rate was higher than in rural districts with less medical facilities (6.9 vs. 4.4/100,000 inhabitants). Only 46 (35%) of the patients with MRSA cultured in their blood had been detected via anamnesis as patients on risk for MRSA, and 59 (45%) had been screened for MRSA on admission. The incidence rate in the different hospitals was 0.041 ± 0.031/1,000 patient days (range 0-0.145/1,000 patient days).

CONCLUSIONS

For the first time, data on notification of MRSA cultures in blood specimen are published from a whole MRE Network in Germany encompassing >2.1 million inhabitants. Incidence rates per 100,000 inhabitants alone do not seem adequate to cope with the aims of the obligation for notification. Instead, reference to patient days in the respective clinic enables an external comparison to other medical institutions in the region and is a better base for discussion with these institutions on improvements of surveillance, screening and hygiene.

Early implementation of antifungal therapy in the management of febrile neutropenia is associated with favourable outcome during induction chemotherapy for acute leukaemias

BACKGROUND

Mortality related to induction chemotherapy during the treatment of acute leukaemias (AL) has been estimated at 5-20%, and this increases with age. Fungal infection remains one of the major causes of morbidity and mortality and is considered an obstacle to the successful management of acute leukaemias.

METHODS

We retrospectively analysed all patients treated for acute leukaemias at a single institution between July 2006 and January 2009, to assess the impact of early antifungal therapy on outcome during induction chemotherapy. There were 44 episodes of induction chemotherapy, with a median age of patients of 61 years (range 18-81), including 29 patients with acute myeloid leukaemia, 9 with acute lymphoblastic leukaemia and 6 with relapsed AL. The median age was 61 years (range 18-81), and 20 patients were over the age of 60 years.

RESULTS

All patients who developed febrile neutropenia received broad-spectrum antibiotics. Early empirical antifungal treatment was commenced with voriconazole (15 patients) or caspofungin (12 patients) if the febrile neutropenia did not resolve after 72 h of antibiotic therapy, in conjunction with radiological changes consistent with possible fungal infection. None of the patients succumbed during induction chemotherapy. The 120-day mortality rate after the induction therapy was 2.2%, without any incidence of invasive fungal disease.

CONCLUSION

Our analysis shows that early empirical treatment for fungal infection with voriconazole or caspofungin is associated with a favourable outcome of induction therapy for acute leukaemias. Further studies to confirm this finding are warranted.

Carriage of methicillin-resistant Staphylococcus aureus by veterinarians in Australia

OBJECTIVE

To estimate the prevalence of carriage of methicillin-resistant Staphylococcus aureus (MRSA) among Australian veterinarians.

METHODS

Individuals attending veterinary conferences in Australia in 2009 were recruited to provide nasal swabs and complete a questionnaire about their professional activities. Swabs were processed by standard methods for detecting MRSA and questionnaire responses were used to group veterinarians according to their areas of major work emphasis (species and practice type). Prevalence was estimated for each of these grouping and contingency tables and regression tree analysis used to explain the variation in MRSA carriage.

RESULTS

Among the 771 respondents 'industry and government veterinarians' (controls) had the lowest prevalence of MRSA carriage at 0.9%. Veterinarians with horses as a major area of work emphasis had a prevalence of 11.8% (13-fold that of controls) and those whose only major emphasis was horses had a prevalence of 21.4% (23-fold that of controls). Veterinarians with dogs and cats as a major activity had a 4.9% prevalence (5-fold that of controls). Prevalence rates for other major activities (pigs, dairy and beef cattle, avian and wildlife) were also increased, but were estimated from smaller numbers of respondents. Regression tree analysis clearly isolated equine veterinarians and dog and cat practitioners as groups at increased risk of carriage of MRSA.

CONCLUSION

Carriage of MRSA is a notable occupational health issue for veterinarians in clinical practice in Australia, particularly those who work with horses.

Whipple's disease and Tropheryma whippelii: secrets slowly revealed

Whipple's disease was described in 1907 and was designated "intestinal lipodystrophy," despite the detection of bacteria in 1 specimen. This finding was later substantiated by the success of antibiotic therapy, which resulted in dramatic clinical responses, and by use of electron microscopy, which detected monomorphic bacilli in affected tissues. Many attempts at culture failed, and these bacteria were characterized as actinomycetes for the first time by means of broad-range 16S rDNA amplification and molecular phylogenetic methods. The name "Tropheryma whippelii" was proposed for this bacterium. Whipple's disease is a systemic disease that affects many organ systems, producing protean manifestations. This article summarizes recent developments with regard to this topic as well as unanswered questions regarding the pathogenesis and acquisition of infection, the biology and ecology of the organism, the clinical spectrum of disease, diagnosis of the disease, and therapy.

Tropheryma whippelii DNA is rare in the intestinal mucosa of patients without other evidence of Whipple disease

BACKGROUND

Little is known about the pathogenesis of Whipple disease, the reservoirs of Tropheryma whippelii, and the proportion of persons harboring the bacterium without "classic" intestinal abnormalities.

OBJECTIVE

To assess the presence of T. whippelii in patients undergoing upper endoscopy for a variety of indications.

DESIGN

Prospective and routine diagnostic examination of patients.

SETTING

Three academic medical centers in California; Minnesota; and Heidelberg, Germany.

PATIENTS

342 patients undergoing endoscopy for evaluation of dyspepsia or possible peptic ulcer (group A, 173 patients), malabsorption (group B, 37 patients), or clinical suspicion of Whipple disease (group C, 132 patients).

MEASUREMENTS

Small-intestinal biopsy specimens were tested by polymerase chain reaction for T. whippelii DNA and examined for histopathologic abnormalities.

RESULTS

All patients with negative histologic findings also had negative results for T. whippelii DNA.

CONCLUSIONS

T. whippelii occurs only rarely in intestinal mucosa that lacks histopathologic evidence of Whipple disease. The human small intestinal mucosa is an unlikely reservoir for this organism.

Helicobacter pylori vacA genotypes and cagA gene in a series of 383 H. pylori-positive patients

BACKGROUND

Only 10-15% of all patients infected with Helicobacter pylori develop peptic ulcer disease (PUD) or gastric cancer. Apart from immunological factors in the host, virulence determinants of H. pylori such as the vacuolating cytotoxin (VacA) or the cytotoxin-associated protein A (CagA) might represent a predisposition for the development of PUD.

METHODS

We studied antral biopsies of 383 H. pylori-positive patients with peptic ulcer disease (PUD) or other H. pylori-related diseases for H. pylori vacA genotypes and the presence of the cagA gene by PCR.

RESULTS

VacA genotypes and cagA status could be completely determined in 357 (93.2%) of the patients. In 91 (93.8%) of 97 patients with PUD, the vacA s1 genotype (s1m1, 45; s1m2, 46 patients) was present. The vacA s2m2 genotype was found in only 6 (6.2%) of 97 patients with PUD. In contrast, 180 (75.3%) of 239 patients (s1m1, 89; s1m2, 91 patients) without PUD and without gastric malignancies harbored strains with the vacA s1 genotype. The vacA genotype s2m2 was found in 59 (24.7%) of these patients. The presence of the cagA gene was closely associated with the vacA genotype s1 and found in 124 (88.6%) and in 113 (80.7%) of patients with the s1m1 or s1m2 genotypes, respectively, whereas strains with the genotype s2m2 were almost exclusively cagA negative.

CONCLUSION

Most H. pylori strains found in patients with PUD possess the vacA s1 genotype and the cagA gene. Patients with this type of H. pylori strain but without PUD might be at higher risk of developing PUD. In contrast, the risk for PUD might be significantly decreased in those patients who are infected by H. pylori strains with the vacA s2 genotype lacking the cagA gene.

Organization, structure, and variability of the rRNA operon of the Whipple's disease bacterium (Tropheryma whippelii)

Whipple's disease is a systemic disorder associated with a cultivation-resistant, poorly characterized actinomycete, Tropheryma whippelii. We determined a nearly complete rRNA operon sequence of T. whippelii from specimens from 3 patients with Whipple's disease, as well as partial operon sequences from 43 patients. Variability was observed in the 16S-23S rRNA spacer sequences, leading to the description of five distinct sequence types. One specimen contained two spacer sequence types, raising the possibility of a double infection. Secondary structure models for the primary rRNA transcript and mature rRNAs revealed rare or unique features.

Diagnostic relevance of the detection of Legionella DNA in urine samples by the polymerase chain reaction

Urine samples from 317 patients with pneumonia and from 242 patients without pneumonia were tested using a polymerase chain reaction (PCR) system for detection of the Legionella 5S rRNA gene. The results were compared with findings obtained using the established methods for diagnosis of legionellosis. Of the 317 patients with pneumonia, 58 had confirmed legionellosis, 35 had a presumptive Legionella infection, and 224 had no evidence of Legionella infection as determined by conventional methods using published criteria. The PCR was positive for 42 patients with confirmed infections, yielding a sensitivity of 72.4%. Furthermore, 16 (47%) patients with presumptive legionellosis and five (2.2%) patients without other evidence of Legionella infection had positive results. All samples from 242 patients without pneumonia were PCR-negative. When the results for all patients were considered, the specificity of the assay was > or =98.9%. The results demonstrate that the sensitivity and specificity values of urinary PCR are in the same range as those of established methods. The use of PCR in urine complements the repertoire of rapid diagnostic methods, especially for infections caused by legionellae not belonging to Legionella pneumophila serogroup 1, in which tests for detection of urinary antigen often fail.

Direct determination of Helicobacter pylori vacA genotypes and cagA gene in gastric biopsies and relationship to gastrointestinal diseases

OBJECTIVE

Our aim was to detect Helicobacter pylori (H. pylori) from gastric biopsies of 248 patients using a novel, polymerase chain reaction (PCR)-based methodology, which simultaneously facilitates the determination of H. pylori vacA genotypes and cagA gene.

METHODS

A simple methodology for sample preparation was established and PCR was performed with primer systems for the 16S rRNA, vacA, and cagA genes, thus circumventing the need to culture H. pylori and to extract DNA from biopsy samples.

RESULTS

Infection with H. pylori was detected in 147 (59.3%) of 248 patients. The vacA signal sequence genotype s1 was present in 104 (81.3%) of 128 H. pylori-positive patients, and 24 (18.8%) patients had the genotype s2. The vacA middle region types m1 and m2 were detected in 46 (35.9%) and 79 (61.7%) patients, respectively. The combinations s1/m2 (43%) and s1/m1 (35.9%) were found more frequently than s2/m2 (18.8%). The cagA gene was detected in 75 (72.1%) of 104 H. pylori-positive biopsies with the vacA genotype s1. All 24 biopsies with the type s2 were cagA negative. Strains of the type vacA s1 were found in 97% of H. pylori-positive patients with peptic ulcer disease and were associated with the presence of the cagA gene, whereas 96% of the strains of the type vacA s2 were detected in patients who only had nonulcer dyspepsia.

CONCLUSIONS

Using a novel PCR-based methodology, H. pylori 16S rRNA gene, vacA genotypes, and cagA gene can now be rapidly detected directly in gastric biopsies with high accuracy. These data demonstrate that infection with H. pylori strains of the vacA s1 genotype and the cagA gene are more likely to result in peptic ulcer disease. Determination of vacA genotypes and cagA gene may contribute to the potential clinical identification of patients at different levels of risk.

Detecting legionellosis by unselected culture of respiratory tract secretions and developing links to hospital water strains

For a 13-month period, all respiratory tract secretions submitted for routine bacteriology from a large hospital complex were cultured for legionella, irrespective of clinical diagnosis and laboratory requests. Ten cases of legionellosis were detected in this manner, three of which met a strict epidemiological definition of hospital-acquired. Therefore, the 16 warm-water systems of the hospitals, spread out over two locations, were examined for the presence of legionella. Legionella pneumophila was found in 15 warm water systems, with a distinct pattern of serogroups between the two locations. Legionella of the same serogroups as those isolated from patients were present in each hospital water supply. The isolates were further typed by monoclonal antibodies and by genomic macrorestriction analysis. Similarity between clinical and environmental isolates was found in seven cases. In these cases, acquisition from the hospital water supply appears very likely. The strains of the remaining three patients did not match those in hospital water, suggesting that community-acquired legionellosis was occurring as well. This study suggests that routinely culturing respiratory tract secretions of pneumonia patients for legionella can help diagnose unsuspected cases of legionellosis. Typing legionella strains beyond the serogroup level with tools such as macrorestriction analysis is useful to define sources of infection, which can then be targeted for control measures.

Molecular probes for the detection of pathogenic fungi in the presence of human tissue

Four primer systems, amplifying fragments of the gene coding for the small ribosomal subunit (18S rRNA) were characterised with pure cultures of 65 medically relevant fungal species plus two mushrooms. A primer cocktail (TR1/CA1-TR2/AF2) amplified 59 of 67 fungal species; the universal fungal primer 1 (UF1) in combination with the eukaryotic primers S3 or EU1 amplified 64 and 65 of 67 fungal species, respectively. The design of an additional primer (RZY1) enabled the amplification of the missing members of the zygomycetes. The primer systems amplified all the medically relevant fungi tested. These included eight Candida spp. and seven other yeast species, 13 dermatophytes, 32 moulds (including six zygomycetes and five dimorphic fungi) and two mushrooms. Eleven controls including DNA from Schistosoma mansoni, Escherichia coli, Mycobacterium tuberculosis and man were not amplified. The oligonucleotide CA hybridised with C. albicans, C. tropicalis and C. parapsilosis; the oligonucleotide TR hybridised with the 13 dermatophytes; the oligonucleotide AF hybridised with Aspergillus fumigatus, A. flavus, A. terreus, A. nidulans, A. versicolor, A. tamarii, A. clavatus, A. fischeri, but not with A. niger or A. versicolor; and the oligonucleotide HC hybridised with three varieties of Histoplasma capsulatum. These oligonucleotides did not hybridise with the other fungi nor the controls. The specificity of the newly designed primer systems was confirmed by selective amplification of fungal DNA from human lung tissue spiked with fungal biomass and from vitrectomy fluid of a patient with candida endophthalmitis.

Transmission risk of Borrelia burgdorferi sensu lato from Ixodes ricinus ticks to humans in southwest Germany

The risk of Borrelia burgdorferi infection and the value of antibiotic prophylaxis after tick bite are controversial. In this study, performed in two areas of southwestern Germany, ticks were collected from 730 patients and examined by the polymerase chain reaction (PCR) for B. burgdorferi. To assess whether transmission of B. burgdorferi occurred, the patients were clinically and serologically examined after tick removal and during follow-up examinations. Data from all tick bites gave a total transmission rate of 2.6% (19 patients). Eighty-four ticks (11.3%) were PCR positive. Transmission occurred to 16 (26.7%) of 60 patients who were initially seronegative and could be followed up after the bite of an infected tick. These results indicate that the transmission rate from infected ticks in Europe is higher than previously assumed. Examination of ticks and antibiotic prophylaxis in the case of positivity appears to be indicated.

Diversity of Helicobacter pylori vacA and cagA genes and relationship to VacA and CagA protein expression, cytotoxin production, and associated diseases

The vacuolating cytotoxin and the cytotoxin-associated protein, encoded by vacA and cagA, respectively, are important virulence determinants of Helicobacter pylori. Sixty-five H. pylori strains were isolated from dyspeptic patients (19 with peptic ulcer disease, 43 with chronic gastritis, and 3 with gastric cancer) and studied for differences in the vacA and cagA genes and their relationship to VacA and CagA expression, cytotoxin activity, and the clinical outcome of infection. By PCR, fifty-four (83.1%) of 65 strains had the vacA signal sequence genotype s1 and only 10 (15.4%) had the type s2. After primer modification, the vacA middle-region types m1 and m2 were detected in 24 (36.9%) and 41 (63.1%) strains, respectively. The combinations s1-m2 (31 [47.7%]) and s1-m1 (23 [35.4%]) occurred more frequently than s2-m2 (10 [15.4%]) (P = 0.01). No strain with the combination s2-m1 was found. All 19 patients with peptic ulcers harbored type s1 strains, in contrast to 32 (74.4%) of 43 patients with gastritis (P = 0.02). The vacA genotype s1 was associated with the presence of cagA (P < 0.0001), VacA expression (P < 0.0001), and cytotoxin activity (P = 0.003). The cagA gene was detectable in 48 (73.8%) of 65 isolates and present in 16 (84.2%) of 19 ulcer patients and 29 (67.4%) of 43 patients with gastritis (P = 0.17). The vacA genotypes of German H. pylori isolates are identical to those previously reported. H. pylori strains of vacA type s1 are associated with the occurrence of peptic ulceration and the presence of cagA, cytotoxin activity, and VacA expression.

Environmental occurrence of the Whipple's disease bacterium (Tropheryma whippelii)

Whipple's disease is a systemic disorder in which a gram-positive rod-shaped bacterium is constantly present in infected tissues. After numerous unsuccessful attempts to culture this bacterium, it was eventually characterized by 16S rRNA gene analysis to be a member of the actinomycetes. The name Tropheryma whippelii was proposed. Until now, the bacterium has only been found in infected human tissues, but there is no evidence for human-to-human transmission. Here we report the detection of DNA specific for the Whipple's disease bacterium in 25 of 38 wastewater samples from five different sewage treatment plants in the area of Heidelberg, Germany. These findings provide the first evidence that T. whippelii occurs in the environment, within a polymicrobial community. This is in accordance with the phylogenetic relationship of this bacterium as well as with known epidemiological aspects of Whipple's disease. Our data argue for an environmental source for infection with the Whipple's disease bacterium.

Recent bacterial and viral infection is a risk factor for cerebrovascular ischemia: clinical and biochemical studies

We performed a case-control study to investigate the role of recent infection as stroke risk factor and to identify pathogenetic pathways linking infection and stroke. We examined 166 consecutive patients with acute cerebrovascular ischemia and 166 patients hospitalized for nonvascular and noninflammatory neurologic diseases. Control subjects were individually matched to patients for sex, age, and season of admission. We assessed special biochemical parameters in subgroups of stroke patients with and without recent infection (n = 21) who were similar with respect to demographic and clinical parameters. Infection within the preceding week was a risk factor for cerebrovascular ischemia in univariate (odds ratio [OR] 3.1; 95% confidence interval (CI), 1.57 to 6.1) and age-adjusted multiple logistic regression analysis (OR 2.9; 95% CI, 1.31 to 6.4). The OR of recent infection and age were inversely related. Both bacterial and viral infection contributed to increased risk. Infection elevated the risk for cardioembolism and tended to increase the risk for arterioarterial embolism. Stroke patients with and without preceding infection were not different with respect to factor VII and factor VIII activity, fibrin monomer, fibrin D-dimer, von Willebrand factor, C4b-binding protein, protein S, anticardiolipin antibodies, interleukin-1 receptor antagonist, soluble tumor necrosis factor-alpha receptor, interleukin-6, interleukin-8, and neopterin. In conclusion, recent infection is an independent risk factor for acute cerebrovascular ischemia. Its role appears to be more important in younger age groups. The pathogenetic linkage between infection and stroke is still insufficiently understood.

Serum antibodies against Helicobacter pylori proteins VacA and CagA are associated with increased risk for gastric adenocarcinoma

Infection with Helicobacter pylori is associated with the development of gastric cancer. To study whether the infection with H. pylori strains expressing the vacuolating cytotoxin (VacA) and/or the cytotoxin-associated protein (CagA) is associated with an increased risk of developing gastric adenocarcinoma, sera of 90 patients with gastric cancer and 90 matched controls with cardiovascular diseases were investigated for the presence of antibodies to VacA and CagA by immunoblot. Although no significant difference in the overall H. pylori seropositivity was found between cancer patients and controls, antibodies against VacA or CagA were significantly more frequent in cancer patients than in control subjects. Seventy-five (97.4%) of 77 H. pylori-positive patients in the cancer group, but only 60 (84.5%) of 71 H pylori-positive control patients had antibodies against either VacA or CagA (chi 2 = 6.63; relative risk, 2.00; 95% confidence interval, 1.18-3.39; P = 0.01). The presence of antibodies against VacA or CagA alone was also associated with an increased cancer risk (92.2% vs 80.3%; chi 2 = 5.30; relative risk, 1.74; 95% confidence interval, 1.08-2.78; P = 0.021, for VacA; and 87.0% vs 74.6%; chi 2 = 4.90; relative risk, 1.61; 95% confidence interval, 1.06-2.45; P = 0.037, for CagA). The relative risk for gastric cancer was mainly elevated in patients under 65 years, but not in patients at or over 65 years. There is evidence that infection with VacA- or CagA-producing H. pylori strains increases the risk of developing gastric cancer, especially in younger patients.

Whipple's disease: staging and monitoring by cytology and polymerase chain reaction analysis of cerebrospinal fluid

BACKGROUND & AIMS

Diagnostic procedures in Whipple's disease usually focus on the intestine, but symptomatic central nervous system involvement is a major threat for patients. The aim of this study was to determine the diagnostic value of cerebrospinal fluid (CSF) analysis.

METHODS

A total of 39 CSF samples and 2 brain biopsy specimens that were obtained from 24 patients with Whipple's disease at various intervals after diagnosis were examined. Five patients presented with neurological symptoms, 3 of them as relapses after therapy. Thirty-two CSF samples were examined by polymerase chain reaction for Tropheryma whippelli and 20 CSF samples by cytology. Brain biopsy specimens were examined histologically.

RESULTS

Positive results were obtained in 4 of 5 patients (80%) with neurological symptoms, in 7 of 10 patients (70%) without neurological symptoms examined before therapy, and in 3 of 11 patients (27%) without neurological symptoms studied during or after therapy. Conversion from positive to negative was observed in 4 patients after antibiotic treatment.

CONCLUSIONS

Testing of CSF in Whipple's disease yields a high rate of positive results, even in patients without neurological symptoms. Examination of CSF is therefore potentially useful for initial staging and for monitoring of the efficiency of therapy.

[Diagnosis of dermatomycoses with polymerase chain reaction]

A polymerase chain reaction (PCR) assay for the detection of dermatophytes was established. The primers "TR1" and "TR2" amplify a 581 bp fragment within the gene coding for the small ribosomal subunit (185 rRNA) of fungi. PCR allowed the detection of isolates of 7 common dermatophytes and in addition several yeasts and moulds. Hybridisation with specific oligonucleotides results in the identification of dermatophytes and Candida albicans. Restriction analysis of the PCR product allowed us to distinguish between dermatophytes and yeasts or moulds. The specificity of the PCR with respect to fungi was assessed by testing human DNA collected from 42 dermis and epidermis specimens as well as DNA from selected plants and animals. To evaluate the clinical relevance of the PCR assay, 69 routinely collected skin and nail specimens were examined by PCR and culture. PCR detected dermatophytes in 35 and culture in 28 of 38 specimens that were classified as positive. Sensitivity of PCR (92%) was higher than that of culture (73%). These results show that PCR has advantages over culture for the detection of dermatophytes.

Epidemiology of Whipple's disease in Germany. Analysis of 110 patients diagnosed in 1965-95

BACKGROUND

The epidemiology of Whipple's disease (WD) is obscure. To obtain basic data, we performed an evaluation of WD patients in Germany.

METHODS

Information was collected from 110 WD patients diagnosed during 1965-95 at 5 institutions in different regions of Germany. Four items were evaluated: 1) year in which the diagnosis was made; 2) residence and 3) age at the time of diagnosis; and 4) sex.

RESULTS

WD patients originated from all parts of Germany. The incidence of new cases was relatively stable, with a mean of one to two cases per year per collecting centre. In 1995, a maximum of 13 new WD patients was diagnosed. There was a significant increase in the mean age of patients (1965-75, 48.7 years; confidence interval, +/- 3.98 years; 1976-85, 50.7 years, +/- 3.69 years; 1986-95, 57.0 years, +/- 2.80 years; P < 0.01) and an increasing proportion of women (1965-85, 4%; 1986-1995, 22%).

CONCLUSIONS

Whipple's disease is not quite as rare as commonly assumed. There is no obvious geographic predominance. During the past three decades, the demography of WD patients has changed.

Histology of intestinal Whipple's disease revisited. A study of 48 patients

Whipple's disease is an infectious disorder with intestinal and extra-intestinal manifestations. We reinvestigated the intestinal histology in a series of 48 patients (10 females, 38 males; mean age 56.5 years, standard deviation of the mean +/- 11.2 years). A total of 126 biopsy samples, obtained prior to, during, and after therapy, were evaluated by light microscopy. In 43 patients (90%), histology was consistent with common descriptions, while it was uncommon in 3 patients (6%), and non-diagnostic in 2 patients (4%). During treatment, several alterations occurred. Apart from a continuous decrease in PAS-positive macrophages, the pattern of mucosal infiltration changed from diffuse to patchy. Moreover, the cytological aspects of PAS-positive macrophages changed substantially, and this change was used to propose four different subtypes. Initially, subtype 1 macrophages predominated (74%), but showed a gradual decrease within a few months of therapy. After 15 months, subtype 3 and subtype 4 macrophages predominated (< 80%). In 7 of 9 patients followed over long periods some subtype 3 or subtype 4 macrophages persisted. It is concluded that at diagnosis and during treatment the intestinal histology of Whipple's disease is heterogeneous. A few PAS-positive macrophages commonly persist at long-term follow-up. This and other features suggest the presence of a persistent immune defect.

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.