Risk factors for levofloxacin resistance in Stenotrophomonas maltophilia from respiratory tract in a regional hospital.
OBJECTIVE
Stenotrophomonas maltophilia is a bacterial pathogen associated with health-care associated infections, particularly in immunocompromised patients. Members of the fluoroquinolone drug class are frequently used to treat S. maltophilia infection; however, S. maltophilia resistance to fluoroquinolones, especially levofloxacin, has been increasing.


METHODS
We sought to identify risk factors associated with levofloxacin resistance using a case-control study. We examined sputum from 76 S. maltophilia-positive patients admitted to our hospital between January 1, 2010 and June 30, 2011. Case groups were defined as patients who had S. maltophilia infections resistant to levofloxacin, and control groups were defined as patients who had S. maltophilia infections susceptible to levofloxacin treatment. Patient information including demographics, previous antibiotic use, and other traits were recorded. In addition, S. maltophilia isolates from patient sputum were assessed for antibiotic resistance as well as for the presence of genes associated with drug resistance.


RESULTS
Previous antibiotic treatment with first- or second-generation cephalosporin was found more often in the levofloxacin-susceptible group; by contrast, previous piperacillin/tazobactam treatment occurred more often in the levofloxacin-resistant group. Three genes associated with drug resistance, including SmeA, SmeD, and SpgM were not significantly different between these groups.


CONCLUSIONS
Piperacillin/tazobactam treatment is associated with subsequent isolation of levofloxacin-resistant S. maltophilia from the respiratory tract.
Division of Infectious Disease, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan.
Chien-Jung
CJ
Pien
Department of Internal Medicine, National Taiwan University Hospital Hsin-Chu Branch, Hsin-Chu City, Taiwan; School of Medicine, National Yang-Ming University, Taipei, Taiwan; School of Medicine, National Taiwan University, Taipei, Taiwan.
Han-Yueh
HY
Kuo
Department of Medical Laboratory Medicine and Biotechnology, Yuanpei University, Hsin-Chu City, Taiwan.
Shu-Wen
SW
Chang
Department of Medical Laboratory Medicine and Biotechnology, Yuanpei University, Hsin-Chu City, Taiwan.
Pei-Ru
PR
Chen
Department of Laboratory Medicine, National Taiwan University Hospital Hsin-Chu branch, Hsin-Chu City, Taiwan.
Hui-Wen
HW
Yeh
Department of Bioinformatics, Chung Hua University, Hsin-Chu City, Taiwan.
Chih-Chin
CC
Liu
Department of Medical Laboratory Medicine and Biotechnology, Yuanpei University, Hsin-Chu City, Taiwan; Department of Computer Science and Information Engineering, Providence University, Taichung City, Taiwan. Electronic address: actt19604@gmail.com.
Ming-Li
ML
Liou
D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D016022:Case-Control Studies; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D004363:Drug Utilization; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000453:epidemiology / Q000382:microbiology*; D006761:Hospitals; D006801:Humans; D064704:Levofloxacin / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D010397:Penicillanic Acid / Q000031:analogs & derivatives / Q000627:therapeutic use; D010878:Piperacillin / Q000627:therapeutic use; D000077725:Piperacillin, Tazobactam Drug Combination; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000382:microbiology*; D012307:Risk Factors; D013183:Sputum / Q000382:microbiology; D020615:Stenotrophomonas maltophilia / Q000187:drug effects* / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D000077725:Piperacillin, Tazobactam Drug Combination; D064704:Levofloxacin; D010397:Penicillanic Acid; D010878:Piperacillin
Levofloxacin; Microbial sensitivity tests; Risk factors; Stenotrophomonas maltophilia