Serious Bacterial Infections in Hospitalized Neonates in Eastern Ethiopia: Investigating the Emerging Pathogen <scp> <i>Pantoea dispersa</i> </scp> Compared With <scp> <i>Klebsiella pneumoniae</i> </scp>

BACKGROUND: Serious bacterial infections (SBIs) are major contributors to neonatal morbidity and mortality in low-income countries. We describe the aetiology and risk factors for neonatal bacteraemia and in-hospital mortality in eastern Ethiopia, focusing on Pantoea dispersa, a rarely studied pathogen, and Klebsiella pneumoniae. METHODS: Prospective surveillance was conducted at Hiwot Fana Comprehensive Specialized Hospital (HFCSH), Harar, from December 2021 to November 2023. Blood for culture was drawn from neonates admitted with the WHO clinical definition of possible-SBI (pSBI). Isolates were identified using API kits and antimicrobial susceptibility tested by Kirby-Bauer method. FINDINGS: Among 1375 neonates with pSBI, blood was cultured from 1335 (97%), and 356 (27%) cultured pathogens. The commonest infections were Pantoea species (n = 145, 40.7%) and K. pneumoniae (n = 63, 17.7%); 128 Pantoea isolates were identified as P. dispersa by Matrix-Assisted Laser Desorption Ionization-Time of Flight. Case-fatality-ratios were 25% (32/128), 19% (9/47) and 19% (30/160) for P. dispersa, K. pneumoniae and other monomicrobial infections, respectively. P. dispersa showed resistance to ampicillin (99%) and cefotaxime (85%) but was otherwise broadly susceptible, while K. pneumoniae showed resistance to cefotaxime (100%) and gentamicin (89%), remaining susceptible only to amikacin and meropenem. Compared to non-bacteraemic admissions, P. dispersa bacteraemia was associated with health-facility delivery outside HFCSH (aOR 1.9 [95% CI, 1.21-2.97]), low birth weight (aOR 2.1 [95% CI,1.22-3.47]), and the dry season (aOR 9.7, [95% CI, 4.61-20.31]). K. pneumoniae bacteraemia was associated with health-facility delivery outside HFCSH (aOR, 2.2, [95% CI, 1.09-4.27]) alone. Among admissions with pSBI, death was associated with low birth weight and P. dispersa bacteraemia. INTERPRETATION: Bacteraemia was prevalent among neonates admitted with pSBI to HFCSH. P. dispersa and K. pneumoniae predominated and both had high mortality risks. Rigorous diagnostics and epidemiological associations support the interpretation of P. dispersa as a pathogen, necessitating local investigation into transmission and infection control interventions.