PCR (Polymerase Chain Reaction) is Superior to Culture and Serology in Detecting Haemophilus Infection in Rats and Guinea Pigs

Based on partial sequencing of the 16S rRNA gene V-factor dependent Pasteurellaceae (Haemophilus),  strains from rat and guinea pig were assigned to the Rodent cluster or the Haemophilus parainfluenzae  complex. PCRs for the detection of biotype Heyl or Jawetz [P.] pneumotropica detected none of the strains and only  two Haemophilus strains assigned to the Rodent cluster respectively. All Haemophilus strains were positive  by a PCR developed for detection of all Pasteurellaceae taxa. The Pasteurellaceae PCR detected infection in all 76 rats and 40 guinea pigs from 3 and 6 colonies respectively  reported to be free from Pasteurellaceae infection.  ELISAs, using two Haemophilus antigens and culture, detected infection with similar frequency but both  methods were inferior to PCR. The Pasteurellaceae PCR should be the new ‘gold standard’ for comparison of the sensitivity of other test  methods for Pasteurellaceae infection in rodents.

Process evaluation of two environmental nutrition programmes and an educational nutrition programme conducted at supermarkets and worksite cafeterias in the Netherlands

This article describes the process evaluation of two environmental programs and a educational nutrition program, implemented at supermarkets and worksite cafeterias. Studies conducted earlier, indicated that the programs had no effect on consumers’ eating behavior. Consequently, the more specific purpose of the present study was to identify explanations for the ineffectiveness of the programs and to formulate recommendations for future programs. Materials and Methods The environmental programs included labeling of healthy products and increasing the range of healthy foods on offer. The education program consisted of several elements, such as brochures and a self-help guide. Semi-structured interviews were conducted with twenty-one managers of supermarkets and worksite cafeterias where the programs were implemented. Results Although materials were not always entirely compatible with the different supermarkets and worksite cafeterias, the degree of implementation was satisfactory. According to the managers, the programs were not striking enough, the labeling would have been more effective if it had discriminated between different brands of a product, and the number of new products was too small compared to the total range of foods on offer. Discussion The results can be used to help design and check future intervention programs for use at supermarkets or worksite cafeterias. Recommendations for future programs and research are given

Cellular responses to Plasmodium falciparum erythrocyte membrane protein-1: use of relatively conserved synthetic peptide pools to determine CD4 T cell responses in malaria-exposed individuals in Benin, West Africa

BACKGROUND: Plasmodium falciparum erythrocyte membrane protein-1, a variant antigen of the malaria parasite, is potentially a target for the immune response. It would be important to determine whether there are CD4 T cells that recognise conserved regions. However, within the relatively conserved region, there is variation. It is not possible to test T cell responses from small field samples with all possible peptides. METHODS: We have aligned sequences that are relatively conserved between several PfEMP1 molecules, and chosen a representative sequence similar to most of the PfEMP1 variants. Using these peptides as pools representing CIDRα, CIDRβ and DBLβ-δ domains, DBLα domain, and EXON 2 domain of PfEMP1, we measured the CD4 T cell responses of malaria-exposed donors from Benin, West Africa by a FACS based assay. RESULTS: All the three peptide pools elicited a CD4 T cell response in a proportion of malaria-exposed and non-exposed donors. CD4 T cell proliferation occurs at a relatively higher magnitude to peptide pools from the DBLα and EXON 2 in the malaria-exposed donors living in Benin than in the UK malaria-unexposed donors. CONCLUSIONS: These findings suggest that an immunological recall response to conserved peptides of a variant antigen can be measured. Further testing of individual peptides in a positive pool will allow us to determine those conserved sequences recognised by many individuals. These types of assays may provide information on conserved peptides of PfEMP1 which could be useful for stimulating T cells to provide help to P. falciparum specific B cells

MALDI-TOF MS Using a Custom-Made Database, Biomarker Assignment, or Mathematical Classifiers Does Not Differentiate Shigella spp. and Escherichia coli

Shigella spp. and E. coli are closely related and cannot be distinguished using matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) with commercially available databases. Here, three alternative approaches using MALDI-TOF MS to identify and distinguish Shigella spp., E. coli, and its pathotype EIEC were explored and evaluated using spectra of 456 Shigella spp., 42 E. coli, and 61 EIEC isolates. Identification with a custom-made database resulted in >94% Shigella identified at the genus level and >91% S. sonnei and S. flexneri at the species level, but the distinction of S. dysenteriae, S. boydii, and E. coli was poor. With biomarker assignment, 98% S. sonnei isolates were correctly identified, although specificity was low. Discriminating markers for S. dysenteriae, S. boydii, and E. coli were not assigned at all. Classification models using machine learning correctly identified Shigella in 96% of isolates, but most E. coli isolates were also assigned to Shigella. None of the proposed alternative approaches were suitable for clinical diagnostics for identifying Shigella spp., E. coli, and EIEC, reflecting their relatedness and taxonomical classification. We suggest the use of MALDI-TOF MS for the identification of the Shigella spp./E. coli complex, but other tests should be used for distinction

Genome-wide association studies of Shigella spp. and Enteroinvasive Escherichia coli isolates demonstrate an absence of genetic markers for prediction of disease severity

BACKGROUND: We investigated the association of symptoms and disease severity of shigellosis patients with genetic determinants of infecting Shigella and entero-invasive Escherichia coli (EIEC), because determinants that predict disease outcome per individual patient could be used to prioritize control measures. For this purpose, genome wide association studies (GWAS) were performed using presence or absence of single genes, combinations of genes, and k-mers. All genetic variants were derived from draft genome sequences of isolates from a multicenter cross-sectional study conducted in the Netherlands during 2016 and 2017. Clinical data of patients consisting of binary/dichotomous representation of symptoms and their calculated severity scores were also available from this study. To verify the suitability of the methods used, the genetic differences between the genera Shigella and Escherichia were used as control. RESULTS: The isolates obtained were representative of the population structure encountered in other Western European countries. No association was found between single genes or combinations of genes and separate symptoms or disease severity scores. Our benchmark characteristic, genus, resulted in eight associated genes and > 3,000,000 k-mers, indicating adequate performance of the algorithms used. CONCLUSIONS: To conclude, using several microbial GWAS methods, genetic variants in Shigella spp. and EIEC that can predict specific symptoms or a more severe course of disease were not identified, suggesting that disease severity of shigellosis is dependent on other factors than the genetic variation of the infecting bacteria. Specific genes or gene fragments of isolates from patients are unsuitable to predict outcomes and cannot be used for development, prioritization and optimization of guidelines for control measures of shigellosis or infections with EIEC

A Multifactorial Approach for Surveillance of Shigella spp. and Entero-Invasive Escherichia coli Is Important for Detecting (Inter)national Clusters

Shigella spp. and entero-invasive Escherichia coli (EIEC) can cause mild diarrhea to dysentery. In Netherlands, although shigellosis is a notifiable disease, there is no laboratory surveillance for Shigella spp. and EIEC in place. Consequently, the population structure for circulating Shigella spp. and EIEC isolates is not known. This study describes the phenotypic and serological characteristics, the phenotypic and genetic antimicrobial resistance (AMR) profiles, the virulence gene profiles, the classic multi-locus sequence types (MLST) and core genome (cg)MLST types, and the epidemiology of 414 Shigella spp. and EIEC isolates collected during a cross-sectional study in Netherlands in 2016 and 2017. S. sonnei (56%), S. flexneri (25%), and EIEC (15%) were detected predominantly in Netherlands, of which the EIEC isolates were most diverse according to their phenotypical profile, O-types, MLST types, and cgMLST clades. Virulence gene profiling showed that none of the isolates harbored Shiga toxin genes. Most S. flexneri and EIEC isolates possessed nearly all virulence genes examined, while these genes were only detected in approximately half of the S. sonnei isolates, probably due to loss of the large invasion plasmid upon subculturing. Phenotypical resistance correlated well with the resistant genotype, except for the genes involved in resistance to aminoglycosides. A substantial part of the characterized isolates was resistant to antimicrobials advised for treatment, i.e., 73% was phenotypically resistant to co-trimoxazole and 19% to ciprofloxacin. AMR was particularly observed in isolates from male patients who had sex with men (MSM) or from patients that had traveled to Asia. Furthermore, isolates related to international clusters were also circulating in Netherlands. Travel-related isolates formed clusters with isolates from patients without travel history, indicating their emergence into the Dutch population. In conclusion, laboratory surveillance using whole genome sequencing as high-resolution typing technique and for genetic characterization of isolates complements the current epidemiological surveillance, as the latter is not sufficient to detect all (inter)national clusters, emphasizing the importance of multifactorial public health approaches

Elucidation of Phosphatidylcholine Composition in Krill Oil Extracted from Euphausia superba

High performance liquid chromatography-electrospray tandem mass spectrometry was used to elucidate the phospholipids in krill oil extracted from Euphausia superba, an emerging source for human nutritional supplements. The study was carried out in order to map the species of the choline-containing phospholipid classes: phosphatidylcholine and lyso-phosphatidylcholine. In addition, the prevalent phosphatidylcholine class was quantified and the results compared with prior analysis. The qualification was performed with separation on a reverse phase chromatography column, while the quantification was obtained with class separation on a normal phase chromatography column. An Orbitrap system was used for the detection, and pulsed-Q dissociation fragmentation was utilized for the identification of the species. An asymmetrical exclusion list was applied for detection of phospholipid species of lower concentration, significantly improving the number of species observed. A total of 69 choline-containing phospholipids were detected, whereof 60 phosphatidylcholine substances, among others seven with probable omega-3 fatty acids in both sn-1 and sn-2. The phosphatidylcholine concentration was estimated to be 34 ± 5 g/100 g oil (n = 5). These results confirm the complexity of the phospholipid composition of krill oil, and the presence of long chained, heavily unsaturated fatty acids

Perceived need for mental health care and barriers to care in the Netherlands and Australia

This study of Australian and Dutch people with anxiety or depressive disorder aims to examine people's perceived needs and barriers to care, and to identify possible similarities and differences. Data from the Australian National Survey of Mental Health and Well-Being and the Netherlands Study of Depression and Anxiety were combined into one data set. The Perceived Need for Care Questionnaire was taken in both studies. Logistic regression analyses were performed to check if similarities or differences between Australia and the Netherlands could be observed. In both countries, a large proportion had unfulfilled needs and self-reliance was the most frequently named barrier to receive care. People from the Australian sample (N = 372) were more likely to perceive a need for medication (OR 1.8; 95% CI 1.3-2.5), counselling (OR 1.4; 95% CI 1.0-2.0) and practical support (OR 1.8; 95% CI 1.2-2.7), and people's overall needs in Australia were more often fully met compared with those of the Dutch sample (N = 610). Australians were more often pessimistic about the helpfulness of medication (OR 3.8; 95% CI 1.4-10.7) and skills training (OR 3.0; 95% CI 1.1-8.2) and reported more often financial barriers for not having received (enough) information (OR 2.4; 95% CI 1.1-5.5) or counselling (OR 5.9; 95% CI 2.9-11.9). In both countries, the vast majority of mental health care needs are not fulfilled. Solutions could be found in improving professionals' skills or better collaboration. Possible explanations for the found differences in perceived need and barriers to care are discussed; these illustrate the value of examining perceived need across nations and suggest substantial commonalities of experience across the two countries