Sulfhemoglobinemia is a rare disorder characterized by the presence of
sulfhemoglobin in the blood. It is typically
drug-induced and may cause
hypoxia, end-organ damage, and death through
oxygen deprivation. We present here a case of non-
drug-induced
sulfhemoglobinemia in a 7-day-old preterm infant complicated by
hemolytic anemia. Microbiota compositional analysis of fecal samples to investigate the origin of
hydrogen sulphide revealed the presence of Morganella morganii at a relative abundance of 38% of the total fecal microbiota at the time of diagnosis. M morganii was not detected in the fecal samples of 40 age-matched control preterm infants. M morganii is an opportunistic pathogen that can cause serious
infection, particularly in immunocompromised hosts such as neonates. Strains of M morganii are capable of producing
hydrogen sulphide, and
virulence factors include the production of a diffusible α-
hemolysin. The infant in this case survived intact through empirical oral and intravenous
antibiotic therapy, probiotic administration, and
red blood cell transfusions. This coincided with a reduction in the relative abundance of M morganii to 3%. Neonatologists should have a high index of suspicion for intestinal pathogens in cases of non-
drug-induced
sulfhemoglobinemia and consider empirical treatment of the intestinal microbiota in this potentially lethal condition.