Shewanella algae Bacteremia in a Preterm Newborn

Abstract

To the Editors: Human infections with Shewanella are rare and most commonly involve ears, skin, and soft tissue, with or without bacteremia.1 We report the first case of bacteremia in a child caused by Shewanella algae and the first report in the western hemisphere. A preterm baby boy was born to a 14-year-old mother at 32 weeks of gestation via vaginal delivery at the Carolina University Hospital in Puerto Rico. The mother had been admitted at 24 weeks of gestation and treated for acute pyelonephritis, without bacteremia caused by Escherichia coli. She returned 8 weeks later with advanced preterm labor, intact membranes, and no evidence of chorioamnionitis or infection. The mother reported swimming in seawater early in the pregnancy. The baby had a birth weight of 1640 g and was admitted to the Neonatal Intensive Care Unit. He required mechanical ventilation because of hyaline membrane disease, and he was treated with exogenous surfactant. The baby required inotropic support because of hypotension and poor peripheral perfusion. He was treated with ampicillin and gentamicin. The complete blood count showed neutropenia (neutrophils, 832 per μL). The C-reactive protein was elevated. The blood culture at birth was negative. On the third day of life, a blood culture taken on day 2 showed Gram-negative bacilli. Gentamicin was discontinued, and amikacin and imipenem were added. Disseminated intravascular coagulation was diagnosed requiring blood products transfusions. On the fourth day of life, the organism was identified as Shewanella algae susceptible to amikacin, ciprofloxacin, gentamicin, imipenem, and tobramycin. Blood cultures from the third and fifth day of life showed S. algae. On the seventh day of life, he was successfully weaned from mechanical ventilation. The neutropenia and thrombocytopenia resolved. Blood culture taken on this day was negative. He recovered well after antibiotic treatment for 10 days and was sent home at 18 days old. Shewanella spp. are Gram-negative bacilli, which produce hydrogen sulfide. The S. spp. found in clinical specimens are Shewanella putrefaciens and Shewanella algae, and most isolates from humans are S. algae. The usual source for infection is exposure to seawater.1 The first cases of S. algae bacteremia were reported in Denmark (1999) in 2 patients with chronic leg ulcers. They had been exposed to the same marine environment.2 Bacteremia with S. algae was reported in a Japanese woman undergoing hemodialysis.3 Cases of S. algae bacteremia have been reported in Spain, Japan, Taiwan, and Korea.4–9 Cases of S. algae bacteremia reported in the literature, risks factors, and treatment are summarized in Table 1, Supplemental Digital Content 1, https://links.lww.com/INF/A982. S. algae infections have been reported in children, but there have been no previous reports of bacteremia. Ear infections are common, and a series of 65 cases described children who had otitis media that occurred during the summer.1 Recently, a case of ventriculitis and peritonitis caused by S. algae was reported in Croatia in a child with ventriculoperitoneal shunt. The infection developed after contact with seawater and began as otitis.10 Lourdes García-Fragoso, MD Inés García-García, MD Amarilis Rivera, MD Neonatology section Department of Pediatrics University of Puerto Rico School of Medicine San Juan, Puerto Rico