Klebsiella variicola Infection in a Second Trimester Twin Pregnancy: An Underreported Cause of Chorioamnionitis

Abstract

Background and Clinical Significance:Klebisella variicola belongs to the Klebsiella pneumoniae complex. It is a Gram-negative, facultative anaerobic, and nonmotile bacillus, mainly isolated in plants. However, as an emerging human pathogen, it has been isolated in immunocompromised patients with urinary tract infections, pneumonia, and bacteremia. K. variicola infection in pregnancy, responsible for acute chorioamnionitis, has never been reported. Case Presentation: We present a case of a twin pregnancy at 17 + 5 weeks in which chorioamnionitis and fetal inflammatory responses such as funisitis and chorionic vasculitis were due to an ascending infection of K. variicola. The pathogen was isolated postmortem in fetal blood and tissues and the placenta using MALDI-ToF mass spectrometry (MALDI-ToF MS). The accuracy of this microbiological diagnosis sheds further light on the epidemiology and virulence of K. variicola in the prenatal setting. Conclusions: In the case of miscarriage, microbiological investigations on the fetus should always be recommended to identify the exact microorganism in order to target the medical treatment and manage subsequent pregnancies.

Keywords: Klebsiella variicola; chorioamnionitis; twin pregnancy.

Figure 1

Fetal and placental infection of twin 1. (A): a pulmonary alveolus with a granulocyte and few bacilli (arrow) (HE staining 60×). (B): acute chorioamnionitis with neutrophils within the chorionic plate (HE staining 10×). (C): funisitis, one artery with intramural granulocytes extending to the Wharton’s jelly (HE staining 20×).

Figure 2

Fetal and placental infection of twin 1. (A): pulmonary alveoli with intraluminal neutrophils (arrow) (HE staining 60×). (B): severe chorioamnionitis (HE staining 10×). (C): chorionic vasculitis (arrows) (HE staining 4×).