title: Genital carriage of the genus Haemophilus in pregnancy: species distribution and antibiotic susceptibility.
abstract: Recent reports have hypothesized that colonization of the maternal genital tract with non-capsulated Haemophilus influenzae could result in neonatal invasive disease. In this study, genital carriage of the genus Haemophilus was investigated in 510 pregnant women attending an Italian hospital for routine controls. Overall, vaginal carriage of the genus Haemophilus was 9.0 % (46/510). A high colonization rate with Haemophilus parainfluenzae (37/510, 7.3 %) was found; other species, such as Haemophilus pittmaniae (7/510, 1.4 %) and Haemophilus haemolyticus (2/510, 0.4 %), were detected for the first time in the genital flora by 16S rRNA gene sequencing. Notably, no H. influenzae was identified, in agreement with previous investigations indicating that this species is rarely isolated from the genito-urinary tract of pregnant women. No antibiotic resistance was detected in H. pittmaniae and H. haemolyticus, but quite a high degree of ampicillin (10/37, 27 %) and ciprofloxacin (3/37, 8.1 %) resistance was observed in H. parainfluenzae. Five ampicillin-resistant isolates were β-lactamase producers, whereas five isolates exhibited a β-lactamase-negative ampicillin-resistant (BLNAR) phenotype. Sequencing of penicillin-binding protein 3 revealed that Val511Ala, Asn526Ser, Ala530Ser and Thr574Ala changes were associated with BLNAR phenotypes. Two ciprofloxacin-resistant isolates carried substitutions in both GyrA (Ser84Phe and Asp88Tyr) and ParC (Ser84Tyr and Met198Leu); the other ciprofloxacin-resistant isolate had substitutions in ParC, only (Ser138Thr and Met198Leu). In conclusion, ∼10 % of pregnant women carried a species of Haemophilus in their genital tract. The emergence of non-β-lactamase-mediated resistance in genital H. parainfluenzae is a matter of concern because of the risk of mother-to-baby transmission.
authors.affiliation: Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Rome, Italy.
authors.forename: Rita
authors.initials: R
authors.lastname: Cardines
authors.affiliation: Unit of Microbiology, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Daprai
authors.affiliation: Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Rome, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Giufrè
authors.affiliation: Unit of Microbiology, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Erminio
authors.initials: E
authors.lastname: Torresani
authors.affiliation: Unit of Microbiology, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Maria Laura
authors.initials: ML
authors.lastname: Garlaschi
authors.affiliation: Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Rome, Italy.
authors.forename: Marina
authors.initials: M
authors.lastname: Cerquetti
mesh_terms: D000293:Adolescent; D000328:Adult; D000667:Ampicillin / Q000627:therapeutic use; D002939:Ciprofloxacin / Q000627:therapeutic use; D027081:DNA Gyrase / Q000235:genetics; D027101:DNA Topoisomerase IV / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005260:Female; D005836:Genitalia, Female / Q000382:microbiology*; D006190:Haemophilus / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D006192:Haemophilus Infections / Q000453:epidemiology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D011247:Pregnancy; D060737:Reproductive Tract Infections / Q000453:epidemiology*; D055815:Young Adult; D001618:beta-Lactamases / Q000235:genetics
chemical_list: D002939:Ciprofloxacin; D000667:Ampicillin; D001618:beta-Lactamases; D027101:DNA Topoisomerase IV; D027081:DNA Gyrase