Insertion sequences IS481 and IS1001 are targets for molecular detection of respectively Bordetella pertussis and Bordetella parapertussis. There is a raising concern about specificity of these targets due to sequence similarity with Bordetella holmesii and Bordetella bronchiseptica. The likelihood of false (para)pertussis diagnoses should be correlated with the prevalence of these organisms in the respiratory tract (RT). From October 2010 until September 2011, 2,207 RT samples were submitted to the Belgian reference laboratory for pertussis diagnosis. End-point IS481/IS 1001 PCR and culture were performed for B. pertussis and B. parapertussis. We developed a sensitive culture method followed by screening with matrix-assisted laser desorption/ionisation- time of flight mass spectrometry (MALDI-TOF MS) to look for B. holmesii and B. bronchiseptica in our samples,. Only one B. bronchiseptica and no B. holmesii were detected in RT samples from Belgian patients with pertussis-like symptoms.

Sequence-based typing (SBT) is a discriminatory method widely used to genotype Legionella pneumophila strains. A total of 86 clinical L. pneumophila serogroup 1 (sg1) isolates, collected between January 2000 and December 2010 in the two Belgian National Reference Centres for Legionella pneumophila, were genotyped using the internationally standardised SBT protocol of the European Working Group for Legionella Infections (EWGLI). The isolates could be classified into 31 different sequence types (ST, index of diversity: 0.879). The obtained STs were submitted to the EWGLI SBT-database for L. pneumophila. In our study, ST47 (27.9%) and ST1 (19.8%) were the most frequently detected STs. The detected profiles were a combination of both frequently isolated and unique STs, and of both worldwide distributed and more local strains. Two STs, ST880 and ST881, were new to the EWGLI database. In conclusion, we characterised L. pneumophila sg1 isolates with the SBT method, and created a Belgian profile database that will be useful for future epidemiological studies.

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