Comparison of usefulness of randomly amplified polymorphic DNA and amplified-fragment length polymorphism techniques in epidemiological studies on nasopharyngeal carriage of non-typable Haemophilus influenzae

1 Department of Sera and Vaccine Evaluation, National Institute of Hygiene, Chocimska 24 St, 00-791 Warsaw, Poland 2 Department of Infectious Diseases of Children, Medical University, Wroclaw, Poland Correspondence Ewa Augustynowicz eaugustynowicz{at}pzh.gov.pl Received June 13, 2003 Accepted August 11, 2003 Randomly amplified polymorphic DNA (RAPD) and automated amplified-fragment length polymorphism (AFLP) techniques with fluorescently labelled primers were used to type non-serotypable Haemophilus influenzae (NTHI) isolates. Eighty-seven isolates from healthy children attending day-care centres or living at orphanages in southern Poland were investigated. Through comparison of the AFLP data with RAPD analysis, it has been concluded that the discriminatory power of AFLP for NTHI typing is higher than RAPD. Generally, the NTHI isolates analysed were highly heterogeneous, as detected with a Hin dIII/ Taq I AFLP genotyping scheme on intra/inter similarity levels of 94 and 96 % using Pearson's correlation coefficient. The range of similarity values found for isolates from children permanently residing at a particular day-care centre was much wider than that for isolates from orphanages. AFLP can efficiently access NTHI strain diversity and can monitor their turn-over for comparative typing in local and inter-local epidemiological investigations. Abbreviations: AFLP, amplified-fragment length polymorphism; DCC, day-care centre; Hib, H. influenzae type b; NTHI, non-typable H. influenzae ; RAPD, randomly amplified polymorphic DNA.