title: Haemophilus influenzae serotype b and a capsule-deficient type mutant (b-) invasive disease in a partially vaccinated child in Brazil.
abstract: We report a rare case of infection by two different types of Haemophilus influenzae strains in a child who received only one dose of the H. influenzae serotype b (Hib) conjugate vaccine (DTwP+Hib). The strains were recovered from blood and cerebrospinal fluid (CSF) and were phenotypically identified as Hib and non-typable H. influenzae, respectively, after serological tests. The two strains were characterized by PCR capsular typing, multilocus sequence typing and PFGE. Our results suggest that the infection was caused by the bloodstream invasion by a single Hib strain, followed by the diffusion of the bacteria across the blood-brain barrier and into the CSF. The strain recovered from the CSF, however, was identified as a capsule-deficient type mutant (b(-)) strain. Despite the high efficacy of the Hib conjugate vaccine, the increase in the numbers of strains able to escape the immune system of the vaccinated population advocates continued surveillance.
authors.affiliation: Instituto Nacional de Controle de Qualidade em Saúde, INCQS/FIOCRUZ, Rio de Janeiro, Brazil.
authors.forename: Nathalia G S
authors.initials: NGS
authors.lastname: Caldeira
authors.affiliation: Instituto Nacional de Controle de Qualidade em Saúde, INCQS/FIOCRUZ, Rio de Janeiro, Brazil.
authors.forename: Ivano
authors.initials: I
authors.lastname: de Filippis
authors.affiliation: Laboratório Central/LACEN-PE, Recife, Pernambuco, Brazil.
authors.forename: Tânia
authors.initials: T
authors.lastname: Catão Arruda
authors.affiliation: Hospital C. Picanço, Recife, Pernambuco, Brazil.
authors.forename: Maria Eulália
authors.initials: ME
authors.lastname: Côrte Real
authors.affiliation: Instituto Nacional de Controle de Qualidade em Saúde, INCQS/FIOCRUZ, Rio de Janeiro, Brazil.
authors.forename: Alice
authors.initials: A
authors.lastname: Batalha de Jesus
authors.affiliation: Instituto Nacional de Controle de Qualidade em Saúde, INCQS/FIOCRUZ, Rio de Janeiro, Brazil.
authors.forename: Antonio Eugenio C C
authors.initials: AECC
authors.lastname: de Almeida
mesh_terms: D016667:Bacterial Capsules / Q000235:genetics*; D001938:Brazil; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D005838:Genotype; D006192:Haemophilus Infections / Q000175:diagnosis* / Q000276:immunology / Q000382:microbiology / Q000473:pathology*; D018073:Haemophilus Vaccines / Q000008:administration & dosage / Q000276:immunology; D019741:Haemophilus influenzae type b / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D007223:Infant; D008297:Male; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D009154:Mutation; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D018073:Haemophilus Vaccines