Methods: A retrospective study was conducted for patients presenting to Hartford Hospital between Jan 2012 and Dec 2015. Patient characteristics, source, risk factors for acquisition, and course of infection are reported.
Results: Of 7508 patients with E. coli and K. pneumoniae isolated, 38 (0.5%) had TZP-NS/BL-PS isolated. Twenty-two (58%) were admitted to the hospital; the other 16 had the organism isolated in the ED but were discharged directly. Of the 22 isolates from admitted patients, 12 (55%) were E. coli, 11 (50%) were healthcare-associated, 6 (27%) community-acquired, and 5 (23%) hospital-acquired. TZP-NS/BL-PS strains were predominately isolated from urine [16 (73%)], followed by blood and soft tissue. Patient mean age was 66 ± 20 years, and most [21 (95%)] had at least one typical risk factor for resistance. The most common were previous admission within 6 months (68%), infection within 6 months (64%), and presence of an indwelling catheter (41%). Nine (41%) patients previously received a β-lactam; 2 (9%) received TZP. Fourteen (64%) of these isolates caused symptomatic infection; all were successfully treated with a β-lactam [ceftriaxone, 11 (71%)], fluoroquinolone, or TMP/SMZ. Two patients were treated with TZP, had initial clinical response and were then de-escalated after culture results.
Conclusion: The prevalence of TZP-NS/BL-PS Enterobacteriaceae at our hospital over the last 4 years was low. All infected patients were successfully treated with available antibiotics reported by our lab. Most patients with TZP-NS/BL-PS isolates had conventional risk factors for resistance, but few received TZP previously. The common empiric use of TZP justifies consideration of this phenotype during susceptibility testing in hospitalized patients.
J. Aslanzadeh, None
D. Nicolau, None