Antibiotic-resistant Enterobacter hormaechei at a pediatric intensive care unit in a tertiary hospital in Panama’s Western region

Abstract Background The emergence of carbapenem resistance genes in Gram-negative bacteria is recognized as a major public health challenge. Enterobacter hormaechei remains one the most commonly identified nosocomial pathogens within the Enterobacter cloacae complex (ECC). This study aims to characterize the drug resistance pattern and the molecular typing of New Delhi Metallo-β-lactamase (NDM)-producing E. hormaechei isolated from clinical samples collected from the pediatric intensive care unit (PICU) at a tertiary-level hospital. Methods Antimicrobial drug susceptibility testing was performed with VITEK ® 2. Taxonomic identification and molecular typing were performed using 16 S rRNA gene DNA sequencing and multi-locus sequence typing (MLST). Results The ECC was identified in seven patients (age range: 3 months to 2 years) admitted to the PICU for severe respiratory infections between July and October 2023. Among our sample, 33.3% (2/6) of the patients died, while the remaining four recovered. Six isolates were characterized as E. hormaechei with resistance to beta-lactams, including carbapenems, and presented the bla NDM gene. MLST typing identified the E. hormaechei as ST51 in 83.3% (5/6) of the samples, while one (16.6.2%) was identified as ST113 clone and one of the isolates showed an unassigned ST profile under the PubMLST scheme. Conclusions Our findings confirm the presence of two clones of E. hormaechei in patients from the PICU of our hospital from July to October 2023, mainly ST51. This multidrug-resistant bacteria affected very vulnerable patients: less than 1-year of age, in critical condition and with comorbidities. Our findings highlight the need for early identification and genotyping methods to achieve a better understanding of E. hormaechei strain circulation in hospital settings, enabling clinicians to establish appropriate preventive measures to control the spread of this pathogen.