title: Capsule gene analysis of invasive Haemophilus influenzae: accuracy of serotyping and prevalence of IS1016 among nontypeable isolates.
abstract: We evaluated the accuracy of serologic capsule typing by analyzing capsule genes and related markers among invasive Haemophilus influenzae isolates before and after the introduction of H. influenzae serotype b (Hib) conjugate vaccines. Three hundred and sixty invasive H. influenzae isolates were collected as part of Active Bacterial Core surveillance within the Georgia Emerging Infections Program between 1 January 1989 and 31 July 1998. All isolates were biotyped, serotyped by slide agglutination serotyping (SAST), and evaluated using PCR capsule typing. Nontypeable H. influenzae (NTHi) isolates were probed with Hib cap-gene-containing plasmid pUO38 and with IS1016; a subset was examined with phosphoglucose isomerase (pgi) genotyping and pulsed-field gel electrophoresis (PFGE). Discrepancies between SAST and PCR capsule typing were found for 64/360 (17.5%) of the isolates; 48 encapsulated by SAST were NTHi by PCR, 8 NTHi by SAST were encapsulated by PCR, 6 encapsulated by SAST were a different capsule type by PCR, and 2 encapsulated by SAST were capsule-deficient Hib variants (Hib-minus). None of the PCR-confirmed NTHi isolates demonstrated homology with residual capsule gene sequences; 19/201 (9.5%) had evidence of IS1016, an insertion element associated with division I H. influenzae capsule serotypes. The majority of IS1016-positive NTHi were biotypes I and V and showed some genetic relatedness by PFGE. In conclusion, PCR capsule typing was more accurate than SAST and Hib-minus variants were rare. IS1016 was present in 9.5% of NTHi isolates, suggesting that this subset may be more closely related to encapsulated organisms. A better understanding of NTHi may contribute to vaccine development.
authors: Atlanta Veterans Affairs Medical Center, Medical Research Service 151, 1670 Clairmont Rd., Decatur, GA 30033, USA.
authors: Sarah W
authors: SW
authors: Satola
authors: Julie T
authors: JT
authors: Collins
authors: Ruth
authors: R
authors: Napier
authors: Monica M
authors: MM
authors: Farley
mesh_terms: D000372:Agglutination Tests; D016667:Bacterial Capsules / Q000145:classification* / Q000235:genetics; D015373:Bacterial Typing Techniques; D015139:Blotting, Southern; D002874:Chromosome Mapping; D004251:DNA Transposable Elements; D016521:Electrophoresis, Gel, Pulsed-Field; D019143:Evolution, Molecular; D006193:Haemophilus influenzae / Q000145:classification* / Q000235:genetics; D006801:Humans; D016133:Polymerase Chain Reaction; D012703:Serotyping
chemical_list: D004251:DNA Transposable Elements
references: Mol Microbiol. 1990 Nov;4(11):1853-62
references: 2082145
references: J Clin Microbiol. 1994 Oct;32(10):2382-6
references: 7814470
references: J Infect Dis. 1996 Jan;173(1):180-6
references: 8537657
references: Clin Infect Dis. 1996 Jun;22(6):1069-76
references: 8783712
references: Infect Immun. 1998 Jan;66(1):364-8
references: 9423882
references: J Infect Dis. 1994 Feb;169(2):337-42
references: 8106767
references: Infect Immun. 2006 Nov;74(11):6226-35
references: 16966407
references: Antonie Van Leeuwenhoek. 1978;44(3-4):367-76
references: 313183
references: Clin Infect Dis. 2007 Mar 15;44(6):810-6
references: 17304452
references: J Bacteriol. 1975 May;122(2):443-53
references: 165169
references: Clin Infect Dis. 2005 Dec 1;41(11):e97-103
references: 16267724
references: J Gen Microbiol. 1976 Mar;93(1):9-62
references: 772168
references: MMWR Morb Mortal Wkly Rep. 2002 Aug 16;51(32):706-7
references: 12206286
references: J Clin Microbiol. 2003 Aug;41(8):3473-80
references: 12904341
references: Infect Immun. 1986 Apr;52(1):183-91
references: 3485574
references: Proc Natl Acad Sci U S A. 1986 Feb;83(4):1106-10
references: 3006028
references: J Clin Microbiol. 1982 Jun;15(6):1150-2
references: 7050151
references: J Clin Microbiol. 2003 Apr;41(4):1623-36
references: 12682154
references: Mol Microbiol. 1995 Jan;15(1):107-18
references: 7752885
references: J Med Microbiol. 1984 Aug;18(1):1-16
references: 6146721
references: Ann Intern Med. 1992 May 15;116(10):806-12
references: 1314530
references: Emerg Infect Dis. 2001 May-Jun;7(3):382-9
references: 11384513
references: Pediatr Infect Dis J. 2005 May;24(5):453-6
references: 15876947
references: Science. 1995 Jul 28;269(5223):496-512
references: 7542800
references: J Clin Microbiol. 2003 May;41(5):2080-3
references: 12734251
references: Mol Microbiol. 1991 Jun;5(6):1549-60
references: 1664907
references: J Infect Dis. 1988 Sep;158(3):643-5
references: 3261764
references: Infect Immun. 1985 Aug;49(2):389-95
references: 2991138
references: Clin Microbiol Infect. 2005 Aug;11(8):637-43
references: 16008616
references: Cell. 1988 May 6;53(3):347-56
references: 3284653
references: J Clin Microbiol. 2003 Dec;41(12):5546-50
references: 14662938
references: Pediatrics. 2001 Jul;108(1):E18
references: 11433097
references: Gene. 1977;2(2):95-113
references: 344137
references: Infect Immun. 1985 Jul;49(1):98-103
references: 2861164
references: J Clin Microbiol. 2003 Jul;41(7):3064-9
references: 12843045
references: J Infect Dis. 1992 Jun;165 Suppl 1:S34-5
references: 1588172
references: Lancet. 1993 Apr 3;341(8849):851-4
references: 8096561
references: J Clin Microbiol. 2003 Jan;41(1):393-6
references: 12517878
references: Clin Infect Dis. 2006 Aug 1;43(3):386-7
references: 16804859
references: Clin Infect Dis. 2003 Sep 15;37(6):841-5
references: 12955648
references: Clin Infect Dis. 1995 Nov;21(5):1322-4
references: 8589168
references: Infect Immun. 2005 Sep;73(9):5853-63
references: 16113304
references: J Infect Dis. 1993 Feb;167(2):356-64
references: 8421169
references: J Bacteriol. 2006 Jun;188(11):3870-7
references: 16707679
references: APMIS. 2006 Sep;114(9):633-40
references: 16948816
references: J Exp Med. 1931 Mar 31;53(4):471-92
references: 19869858
references: Epidemiol Rev. 1991;13:113-42
references: 1765109
references: J Bacteriol. 1989 Jun;171(6):3343-7
references: 2785986
references: Infect Immun. 2003 Jun;71(6):3639-44
references: 12761153
references: Pediatrics. 2006 Aug;118(2):e421-9
references: 16882783