Isolation of separate Ureaplasma species from endotracheal secretions of twin patients

Abstract

Isolation of Ureaplasma spp. from preterm neonates and the association with development of bronchopulmonary dysplasia has been previously investigated. However, few studies have contrasted the nature of infection in twins. Here we report that dizygotic twins (1 female, 1 male) born at 24 weeks gestation both yielded culturable Ureaplasma from endotracheal secretions. The samples were part of a serial blind collection cohort of ventilated premature neonates, and analysis of repeat cultures showed stable separate infections over a period of 17 and 21 days respectively. Immunoblot and probe-specific qPCR analysis determined that Twin1 was solely infected with Ureaplasma parvum (specifically serovar 6 by gene sequencing), while Twin2 was solely infected with Ureaplasma urealyticum (specifically genotype A- serovars 2, 5, and 8 by gene sequencing). Immunoblot analysis found that the major surface antigen (multiple-banded antigen; MBA) altered relative mass for both strains during the course of infection. Quantitative PCR analysis of extracted endotracheal aspirates confirmed no evidence of mixed infection for either twin. Failure of sentinel ventilated preterm infants on the same ward to acquire Ureaplasma infection after the first week of birth suggest no cot-to-cot transfer of Ureaplasma infection occurred. This study demonstrated not only a contrasting clinical outcome for a set of twins infected with two separate species of Ureaplasma, but also the first real-time demonstration of MBA alteration and evolution of Ureaplasma over the course of a clinical infection