Infections caused by extended-spectrum beta-lactamase-producing Enterobacterales in hospitalized neonatal foals: Can colonization predict infection?

Background: Infections with extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-PE) contribute to morbidity and mortality in human neonates. In foals, data are scarce. Objectives: Determine the association between ESBL-PE gastrointestinal colonization on hospital admission and infections in hospitalized neonates. Animals: Sixty-seven foals. Methods: Prospective study of foals admitted to a veterinary hospital. Foals were screened for ESBL-PE colonization and for infections. Risk factors and clinical outcomes were analyzed. Results: Seventy-six percent of foals suffered from at least 1 bacterial infection (n = 51/67). Sixty-three non-ESBL bacterial species and 19 ESBL-PE species were isolated. Twenty foals (29.85%) had at least 1 hospital-acquired infection (HAI) and 30 foals (44.8%) suffered from multidrug resistant infections. The prevalence rates of ESBL-PE gastrointestinal colonization on admission and clinical ESBL HAIs were 47.8% (n = 32/67, 41 isolates) and 19.40% (n = 13/67, 19 isolates), respectively. On multivariable analysis, ESBL-PE HAIs were associated with colonization on admission (P =.03, odds ratio [OR] = 4.60). In an outcome analysis, ESBL-PE infection and HAIs were associated with surgery (ESBL-PE infection: P =.04, OR = 4.70; HAI: P =.004, OR = 6.4) and HAI also was associated with increased duration of hospitalization (P <.001, OR = 9.13). The major colonizing and infecting bacterial species were Escherichia coli and Klebsiella spp. Concordant ESBL-PE species were recovered from rectal screening and clinical samples in 7.46% (n = 5/67) of foals. Conclusions and Clinical Importance: On-admission ESBL-PE rectal colonization was associated with ESBL-PE HAI in neonatal foals. The ESBL-PE infections were associated with surgery during hospitalization. These findings emphasize the importance of optimal infection control and treatment of clinical infections in equine neonatal intensive care units.