Second Trimester Fetal Loss Due to Citrobacter koseri Infection: A Rare Cause of Preterm Premature Rupture of Membranes (PPROM)
Maria Paola Bonasoni, Giuseppina Comitini, Mariangela Pati, Giuseppe Russello, Loredana Vizzini, Marcellino Bardaro, Pietro Pini, Roberta Marrollo, Andrea Palicelli, Giulia Dalla Dea, Edoardo Carretto
Abstract
Citrobacter koseri is a facultative anaerobic, motile, non-spore-forming Gram-negative bacillus, which belongs to the family of Enterobacteriaceae. Severe infections due to Citrobacter spp. have been reported in the urinary tract, respiratory airways, intra-abdominal organs, skin and soft tissue, eye, bone, bloodstream, and central nervous system. In newborns, C. koseri is a well-known cause of meningitis, cerebral abscesses, brain adhesions, encephalitis, and pneumocephalus. Infection can be acquired through vertical maternal transmission or horizontal hospital settings; however, in many cases, the source is unknown. Preterm premature rupture of membranes (PPROM), caused by C. koseri, has rarely been described. Herein, we describe a case of PPROM at 16 weeks and 3 days of gestation, leading to anhydramnios. The parents opted for legal termination of the pregnancy, as the prognosis was very poor. C. koseri was isolated postmortem from a placental subamniotic swab and parenchymal sample, as well as fetal blood and lung. To the best of our knowledge, this is the first case of early second-trimester PPROM in which C. koseri infection was demonstrated.