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.

Identification of Burkholderia spp. in the clinical microbiology laboratory: comparison of conventional and molecular methods

Cystic fibrosis (CF) predisposes patients to bacterial colonization and infection of the lower airways. Several species belonging to the genus Burkholderia are potential CF-related pathogens, but microbiological identification may be complicated. This situation is not in the least due to the poorly defined taxonomic status of these bacteria, and further validation of the available diagnostic assays is required. A total of 114 geographically diverse bacterial isolates, previously identified in reference laboratories as Burkholderia cepacia (n = 51), B. gladioli (n = 14), Ralstonia pickettii (n = 6), B. multivorans (n = 2), Stenotrophomonas maltophilia (n = 3), and Pseudomonas aeruginosa (n = 11), were collected from environmental, clinical, and reference sources. In addition, 27 clinical isolates putatively identified as Burkholderia spp. were recovered from the sputum of Dutch CF patients. All isolates were used to evaluate the accuracy of two selective growth media, four systems for biochemical identification (API 20NE, Vitek GNI, Vitek NFC, and MicroScan), and three different PCR-based assays. The PCR assays amplify different parts of the ribosomal DNA operon, either alone or in combination with cleavage by various restriction enzymes (PCR-restriction fragment length polymorphism [RFLP] analysis). The best system for the biochemical identification of B. cepacia appeared to be the API 20NE test. None of the biochemical assays successfully grouped the B. gladioli strains. The PCR-RFLP method appeared to be the optimal method for accurate nucleic acid-mediated identification of the different Burkholderia spp. With this method, B. gladioli was also reliably classified in a separate group. For the laboratory diagnosis of B. cepacia, we recommend parallel cultures on blood agar medium and selective agar plates. Further identification of colonies with a Burkholderia phenotype should be performed with the API 20NE test. For final confirmation of species identities, PCR amplification of the small-subunit rRNA gene followed by RFLP analysis with various enzymes is recommended

Melioidosis in travelers: An analysis of Dutch melioidosis registry data 1985–2018

Background: Melioidosis, caused by the Gram-negative bacterium Burkholderia pseudomallei, is an opportunistic infection across the tropics. Here, we provide a systematic overview of imported human cases in a non-endemic country over a 25-year period. Methods: All 5

Smoking status and peer support as the main predictors of smoking cessation in adolescents from six European countries

We compared 1,335 adolescent smokers and quitters from six European countries with regard to attitudes toward smoking, self-efficacy, social influences, and intentions to quit smoking. At 6-month follow-up, occasional, weekly, and daily smokers who had quit indicated less social influence of friends and siblings toward smoking, acknowledged more disadvantages of smoking, and expressed more confidence that they would be able not to smoke in various tempting situations. Logistic regression analyses revealed that smoking status at baseline and social influence of peers were the main predictors of cessation. Although no large cultural differences were found, the pattern of predictors was not similar for all six countries. As adolescents who smoke regularly are less likely to quit, strategies to prevent them from taking up the habit are important. The influence of peers calls for inclusion of peer groups in cessation strategies

Work and learning: opportunities and risks Proceedings of a European conference in memory of prof.dr. Ben van Onna

Item does not contain fulltex

Peptide imprinted receptors for the determination of the small cell lung cancer associated biomarker progastrin releasing peptide

Peptide imprinted polymers were developed for detection of progastrin releasing peptide (ProGRP); a low abundant blood based biomarker for small cell lung cancer. The polymers targeted the proteotypic nona-peptide sequence NLLGLIEAK and were used for selective enrichment of the proteotypic peptide prior to LCMS based quantification. Peptide imprinted polymers with the best affinity characteristics were first identified from a 96-polymer combinatorial library. The effects of functional monomers, crosslinker, porogen, and template on adsorption capacity and selectivity for NLLGLIEAK were investigated and optimized. Ultimately, a solid phase extraction method was developed for highly selective enrichment of the target peptide from tryptic digests