Intrauterine infection by non-capsulated Haemophilus influenzae in a case of maternal immunodeficiency

Neonatal, urogenital isolates of biotype 4 nontypeable Haemophilus influenzae express a variant P6 outer membrane protein molecule

The P6 outer membrane protein is a highly conserved molecule which is present on the surface of all strains of Haemophilus influenzae. Sixty strains of nontypeable H. influenzae which caused invasive disease or colonized the female urogenital tract were studied with monoclonal antibodies 7F3 and 4G4, which recognize different surface-exposed epitopes on the P6 molecule. All 60 strains expressed the epitope recognized by 4G4, whereas 47 of 60 strains expressed the epitope recognized by antibody 7F3. The 7F3-nonreactive strains were all biotype 4 and were recovered from the blood of neonates or postpartum women or from the female urogenital tract. The P6 genes from two 7F3-nonreactive strains were cloned, and the nucleotide sequences were determined. Analysis of amino acid sequences, immunoassays with synthetic peptides, and site-directed mutation of the P6 gene indicate that the epitope recognized by antibody 7F3 is conformational and that the sequence Asp-Ile-Thr is critical in maintaining the conformation of the epitope. We conclude that the unusually virulent clone family of biotype 4 strains of nontypeable H. influenzae express a variant P6 molecule which has an alteration in a highly conserved surface-exposed epitope.

Non-capsulated Haemophilus influenzae in the genital flora of pregnant and post-puerperal women

Non-capsulated Haemophilus influenzae may cause neonatal septicaemia. Genital carriage of this pathogen was studied in 3 mothers of infected neonates and in 2 pregnant women in the first trimester. A carrier state in 2 of the females was terminated by antibiotic therapy after 3 and 7 months, respectively. A previous carrier had no recurrence of H. influenzae in a subsequent pregnancy. A survey of 544 parturient women revealed a carrier rate of 1.8/1,000 (95% confidence limits: 0.1-11). Carriage of non-capsulated H. influenzae is thus rare, and pregnant women may be successfully treated in order to reduce the risk of neonatal infection. There was no evidence of immunodeficiency in women with non-capsulated H. influenzae in the genital tract.

Fulminant neonatal sepsis due to Haemophilus influenzae

A case of fulminant neonatal Haemophilus influenzae sepsis is presented. A 29-year-old woman presented at 34 weeks gestation with premature labor but with intact membranes. The male infant died 8 h after delivery due to respiratory insufficiency. Ante-mortem blood cultures and post-mortem blood and lung cultures yielded H. influenzae (biotype II) which could not be serotyped. H. influenzae was cultured from the mother's cervix 5 days after delivery. This strain was of the same biotype and also nonserotypable. Serum obtained from the mother exhibited reduced bactericidal activity against the isolates. We suggest the use of selective media in routine cervix cultures from pregnant women to detect H. influenzae, which might be responsible for neonatal septicemia.

Biotypes, serotypes, and susceptibility to antibiotics of 60 Haemophilus influenzae strains from genitourinary tracts

Sixty strains of Haemophilus influenzae were isolated from the genitourinary tracts of adults: 19 from cervicovaginal secretions, one from a woman with bartholinitis, 37 from urethral exudates, and three from urine. Non-capsulated strains were recovered predominantly, and biotype III accounted for 28 isolates and biotype IV for 25. Many of the H influenzae strains were found to be resistant to one or more of the antibiotics commonly used against sexually transmitted diseases. Resistance to tetracycline was prevalent and was found in 17 of the strains. Ten strains were ampicillin resistant and beta lactamase producing. Kanamycin resistance was less common (two strains). Trospectomycin (U-63366), a new spectinomycin analogue, was eight to 16 times more active than spectinomycin. All the quinolones tested were very active against all strains and may provide an effective alternative for the treatment of resistant H influenzae in genitourinary infections.

Haemophilus influenzae: comparison of respiratory tract isolates with genitourinary tract isolates

Haemophilus influenzae isolates recovered from the genitourinary (GU) tract were shown to have a significantly different biotype distribution compared with respiratory tract isolates. Biotype IV strains were recovered more commonly from the GU tract, and most strains were non-serotypable. Antibiotic-susceptible strains isolated from the GU tract more frequently harbored plasmids of less than 10 megadaltons than did antibiotic-susceptible respiratory tract strains. One 2.8-megadalton plasmid resident in a GU tract isolate and one 1.8-megadalton plasmid resident in a respiratory tract isolate were shown to be related to the small ampicillin resistance plasmids previously described in H. influenzae, Haemophilus parainfluenzae, Haemophilus ducreyi, and Neisseria gonorrhoeae. This supports the suggestion that these ampicillin resistance plasmids originated by transposition or recombination of the ampicillin transposon (TnA) with cryptic endogenous Haemophilus plasmids.