Epidemiology and antibiotic resistance trends of Pantoea species in a tertiary-care teaching hospital: A 12-year retrospective study

Pantoea species are pigmented, Gram-negative rods belonging to the Enterobacterales order. They are considered rare, opportunistic pathogens and are mostly implicated in nosocomial outbreaks affecting neonates and immunocompromised patients. The aim of this study was to describe the prevalence and antibiotic susceptibility of Pantoea species during a 12-year period. This retrospective study was carried out using microbiological data collected between January 1, 2006 and December 31, 2017. Patients’ data such as age, sex, inpatient/outpatient status, and empiric antibiotic therapy were also collected. Antimicrobial susceptibility testing was performed using E-tests; the interpretation was based on European Committee on Antimicrobial Susceptibility Testing breakpoints for Enterobacterales. Seventy individual Pantoea spp. isolates were identified; the most frequently isolated species was Pantoea agglomerans. Most isolates were susceptible to relevant antibiotics. In 61 out of 68 patients, ampicillin was the empirically administered antibiotic. The highest levels of resistance were to amoxicillin–clavulanic acid and ampicillin. No extended spectrum beta-lactamase-positive isolate was detected. There is a scarcity of data available on the susceptibility patterns of Pantoea species, but our results correspond to what we could find in the literature. The development of multidrug-resistant (MDR) Gram-negative bacteria is a grave concern, and the development of MDR Pantoea spp. may be expected in the future.