2028. Comparison of Treatment Outcomes between Minocycline, Trimethoprim-Sulfamethoxazole (TMP/SMX) and Fluoroquinolone (FQ) Monotherapy for Stenotrophomonas maltophilia Infections
Session: Poster Abstract Session: Antimicrobial Resistant Infections: Treatment
Saturday, October 29, 2016
Room: Poster Hall

S. maltophilia is an inherently resistant organism with limited treatment options. TMP/SMX is considered first-line therapy. FQs appear to have similar clinical success, but data is limited. Due to high susceptibility rates (99%) and clinical success of minocycline treatment at our institution (ICAAC 2015), we compared the clinical outcomes of these agents for S. maltophilia infections.


We retrospectively reviewed patient records of adults receiving minocycline, TMP/SMX or FQ with a documented S. maltophilia culture from January 2010-2016. Patients were excluded if initial monotherapy was not received for ≥48 hours, if pregnant, or had Cystic Fibrosis. “Clinical failure” was defined as isolation of S. maltophilia from a later same site culture within 30 days, change in therapy due to adverse event or concern for clinical failure, or 30 day in-hospital mortality.


113 patients were included. Monotherapy with minocycline, TMP/SMX, or FQ was used in 31%, 38%, and 31% of patients, respectively. Using CSLI standards for interpretation of susceptibility by Etest®, most isolates were susceptible to the initial agent used (100% of minocycline, 98% of TMP/SMX, and 100% of FQ). The mean Charlson score was higher in the minocycline group compared to that of TMP/SMX (5.5 vs. 3.3; p<0.016) and of FQ (5.5 vs. 3.8; p <0.003). More patients in the minocycline group were treated in the ICU compared to that of TMP/SMX (45 vs. 23%; p<0.04) and of FQ (45 vs. 11%; p<0.002). No difference between the TMP/SMX and FQ groups Charlson scores or initial treatment in the ICU was noted. There was no significant difference between serious infections (pneumonia or bacteremia) among any of the groups (minocycline 68.5%, TMP/SMX 83.6%, FQ 77%; p>0.05 for all comparisons). Clinical failure was lower in the minocycline vs. TMP/SMX groups (11 vs. 49%; p=0.007) and in the FQ vs. TMP/SMX groups (14 vs. 49%; p=0.001) but not between the minocycline and FQ groups (11 vs. 14%; p>0.05). 


Despite higher rates of baseline illness, patients in the minocycline group had a lower incidence of clinical failure than patients treated with TMP/SMX and similar incidence as those treated with FQ suggesting that minocycline may be a good choice for infections caused by S. maltophilia.


Zahia Esber, MD, Orlando Health, Orlando, FL, Shauna Jacobson, PharmD, Pharmacy, Orlando Health, Orlando, FL, R. Brigg Turner, Pharm D, School of Pharmacy, Pacific University, Hillsboro, OR and Mary Catherine Bowman, MD, PhD, Infectious Disease, Orlando Health, Orlando, FL


Z. Esber, None

S. Jacobson, None

R. B. Turner, None

M. C. Bowman, None

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