Typing of urogenital, maternal, and neonatal isolates of Haemophilus influenzae and Haemophilus parainfluenzae in correlation with clinical source of isolation and evidence for a genital specificity of H. influenzae biotype IV

Abstract

Over a period of 6 years, 114 strains of Haemophilus influenza and Haemophilus parainfluenzae were isolated from genital, mother-infant, or neonatal infections. Their serotypes, biotypes, antibiotic resistance phenotypes, and outer membrane protein (OMP) electrophoretic patterns were characterized and correlated with the various clinical outcomes. Genital H. influenza and H. parainfluenzae appeared to behave mostly as opportunistic pathogens; for instance, 62% of the cases of endometritis or pelvic inflammatory disease were related to the presence of an intrauterine device. However, as seen clearly in one case, the strains may be sexually transmitted. The analysis of OMP patterns proved to be a very convenient method to seek evidence for the sexual origin of the infection. H. influenzae was more often involved in complicated genital infections than was H. parainfluenzae. Nontypeable and biotype II H. injluenzae strains were the more frequent isolates, except in pelvic inflammatory diseases, in which biotype I prevailed, and in mother-infant infections, in which one-fourth of the cases were due to biotype IV. Characterization of H. influenzae isolates did not support a general concept of specific genital strains. However, strains of biotype IV clearly stood out with two characteristics: (i) a peritrichous fimbriation and (ii) a very peculiar homogeneous OMP pattern comprising an OMP of molecular weight '18,000 unique to this biotype. These characteristics were also found in H. influenza biotype IV strains isolated from genital infections in the United States and used as controls. H. influenza biotype IV strains may thus correspond to a group somewhat adapted to the genital tract. * Corresponding author. mostly from neonatal or mother-infant infections in the United States and France (58, 72). However, clinical outcome has been shown to be more severe in Houston, Tex. (72), than in Tours, France (58). To account for this difference, we have compared our own H. influenza biotype IV isolates to nine strains originating in the United States and kindly provided by R. J. Wallace. MATERIALS AND METHODS Patients. Haemophilus spp. were isolated from 1 October 1979 through 31 March 1987 in patients from the Centre Hospitalier Régional et Universitaire Bretonneau in Tours, France. Patients belonged to two groups: women consulting for genital or urinary tract infections and newborn infants suspected to be at risk of infection on the basis of clinical signs in the mother (fever, genital or urinary tract infections, premature rupture of membranes, or premature onset of labor) or overt clinical signs in the child (fever, respiratory distress syndrome, shock, jaundice, or leukopenia). In these cases, bacterial investigations included two placental smears corresponding to both sides of the placenta, an aspiration of the gastric fluid, and swabs of ears, mouth, anus, and nose. In addition, urine analysis, blood cultures, and lumbar punctures were carried out in three circumstances: when the neonate had clinical or biological signs ...

Evolving epidemiology of invasive Haemophilus infections in the post-vaccination era: results from a long-term population-based study

“…Carriage studies have shown that only 1.8/1000 parturient women carry non-encapsulated Hi in their genital tract [18], but they were found in 8/110 women with preterm rupture of membranes [19]. It has been suggested that unusually virulent NTHi biotype II or IV strains may preferentially cause invasive infections among neonates and pregnant women [19][20][21]. Further characterization of the strains in our study may therefore be of interest.…”

Genetic identification of cryptic genospecies of Haemophilus causing urogenital and neonatal infections by PCR using specific primers targeting genes coding for 16S rRNA

“…Genital, perinatal, and neonatal infections due to Haemophilus strains were first described in the early 1900s (5,14,27). The number of reported cases has increased in the last 20 years (7,13,14,22,28). Although specific tropism of some H. influenzae strains for the genital tract has been suggested on the basis of biotyping and serotyping studies (1,18,22,28), analysis of outer membrane protein patterns and genetic characterization of isolates do not support a general concept of specific genital strains.…”

“…The number of reported cases has increased in the last 20 years (7,13,14,22,28). Although specific tropism of some H. influenzae strains for the genital tract has been suggested on the basis of biotyping and serotyping studies (1,18,22,28), analysis of outer membrane protein patterns and genetic characterization of isolates do not support a general concept of specific genital strains. The exception is a very homogeneous group of genital strains, usually assigned to H. influenzae biotype IV, which share singular phenotypic and genotypic characteristics (15,17,19,20,21,22,23).…”

“…The phenotypic characteristics of the clinical isolates have been described previously (2,4,16,22,28). Strains were identified as Haemophilus on the basis of colonial morphology, Gram stain, requirement for hemin and NAD, synthesis of porphyrin, and hemolytic activity (10,11).…”

“…Many of these biotype IV strains from neonatal and urogenital sources have several unusual features. They have characteristic outer membrane protein electrophoretic profiles (22), express a variant P6 outer membrane protein (15), and display increased susceptibility to several quinolones (20). Most of these isolates also express peritrichous fimbriae, adhere more to HeLa cells than to HEp-2 cells, and possess adhesins that do not recognize erythrocyte receptors (23).…”