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

Abstract

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 <10 megadaltons than did antibiotic-susceptible respiratory tract strains. One 2.8megadalton 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. Genitourinary (GU) tract colonization withHaemophilus influenzae appears to be infrequent, and serious infections from this source are uncommon (17,24,33). Previous studies have suggested bacteriological differences between H. influenzae GU tract infections and their associated neonatal infections and the more frequently reported respiratory infections in infants and adults due to this organism (3,8). In general, the organisms isolated from the GU tract are non-encapsulated, and the biotype distribution appears to be different.Since 1976, we have isolated H. influenzae from the GU tract of 82 patients; these isolates include strains from two surveys of GU tract colonization due to this organism in asymptomatic pregnant females and symptomatic males and females in an ambulatory population. This study reports the results of biotyping and plasmid analysis of these GU tract isolates compared with a similar analysis of respiratory tract isolates. MATERIALS AND METHODSBacterial strains and plasmids. GU tract isolates of H. influenzae from 82 patients were analyzed and compared with 122 consecutively isolated respiratory strains. Sixty-four of the GU tract strains were recovt Present address: Sexually Transmitted Diseases Research Laboratory, Center for Infectious Diseases, Centers for Disease Control, Atlanta, GA 30333. ered by routine isolation in the Clinical Microbiology Laboratory of the Health Sciences Centre, Winnipeg,Manitoba, Canada. Five isolates were recovered during a 12-month prospective study of genital tract colonization in 1,724 asymptomatic pregnant women. Twelve isolates were recovered during a 2-month prospective study of 722 symptomatic patients presenting to the Primary Health Care Clinic of the Health Sciences Centre, a clinic responsible for the treatment of sexually transmitted diseases. A single strain was recovered from a genital ulcer lesion in an ongoing prospective study in Nairobi, Kenya. Clinical and demographic data were obtained from a review of hospital charts. The bacterial plasmids used in this study are described in Table 1.Culture m...

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

“…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).…”

Isolation and biochemical characterization of Haemophilus species isolated simultaneously from the oropharyngeal and anogenital areas

“…Recently, several authors (16,21) suggested that H. influenzae biotype IV should be considered a genital and neonatal pathogen. However, the isolation of other biotypes of these species from the genital area has been reported (1,2,13,14). Partly due to the routine use of media that do not support the growth of Haemophilus species (7) or to overgrowth by commensal microbial flora, reports of anogenital infections by H. influenza (2,14) and by H. parainfluenzae (3, 4, 18, 20;M.…”

“…Fuzi, Letter, 1985) are sparse. The development of selective media inhibiting the less fastidious microbial flora while permitting the growth of Haemophilus species allowed a recovery rate varying between 0.2 and 5.3% (1,13,19) from colonized areas.…”

Haemophilus Influenzae and Genital Tract Infections in Children

“…Previous reports (5,9) have indicated that genitourinary strains of H . influenzae recovered from adults are predominaltly untypable and belong to biotypes 2, 3 and 4, whereas the 18 pediatric isolates from the present study were predominantly capsulated and belonged to biotypes 1 and 2.…”