title: Effects of chelators (deferoxamine, deferiprone and deferasirox) on the growth of Klebsiella pneumoniae and Aeromonas hydrophila isolated from transfusion-dependent thalassemia patients.
abstract: Infections are among the leading causes of death for thalassemia major patients. The known predisposing factors of infection include prior splenectomy, iron overload and use of iron chelator such as deferoxamine (DFO). While encapsulated organisms frequently found in splenectomized patients were readily controlled by prophylactic vaccination and vigilant antibiotic treatment, ferrophilic organisms such as Yersinia and Klebsiella remain common pathogens in thalassemic patients. Yersinia infections are more prevalent in temperate regions and Klebsiella infections are commonly found in tropical and subtropical areas. While the use of DFO further aggravates the risk of Yersinia infection, oral chelators such as deferiprone (L1) do not enhance the growth of Yersinia in vitro or in vivo. We found that the growth of Klebsiella was marginally enhanced by DFO in vitro when compared to Yersinia. Such an unfavorable effect was not found in either L1 or deferasirox (DFRA) in vitro. The growth of Aeromonas was not affected by the presence of all three forms of chelators. Therefore, we suggest that factors other than DFO may account for the increased prevalence of Klebsiella and Aeromonas infection in Asian thalassemic patients.
authors.affiliation: Department of Paediatrics and Adolescent Medicine, Queen Mary Hospital, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China. gcfchan@hkucc.hku.hk
authors.forename: Godfrey Chi-Fung
authors.initials: GC
authors.lastname: Chan
authors.forename: Shing
authors.initials: S
authors.lastname: Chan
authors.forename: Pak-Leung
authors.initials: PL
authors.lastname: Ho
authors.forename: Shau-Yin
authors.initials: SY
authors.lastname: Ha
mesh_terms: D016980:Aeromonas hydrophila / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D001565:Benzoates / Q000009:adverse effects / Q000494:pharmacology; D001803:Blood Transfusion; D000077588:Deferasirox; D000077543:Deferiprone; D003676:Deferoxamine / Q000009:adverse effects* / Q000494:pharmacology; D016905:Gram-Negative Bacterial Infections / Q000139:chemically induced* / Q000453:epidemiology; D006801:Humans; D007502:Iron Chelating Agents / Q000009:adverse effects* / Q000494:pharmacology; D019190:Iron Overload / Q000188:drug therapy / Q000382:microbiology; D007700:Kinetics; D007710:Klebsiella Infections / Q000139:chemically induced* / Q000453:epidemiology; D007711:Klebsiella pneumoniae / Q000187:drug effects* / Q000254:growth & development / Q000302:isolation & purification; D015995:Prevalence; D011728:Pyridones / Q000009:adverse effects / Q000494:pharmacology; D013789:Thalassemia / Q000188:drug therapy / Q000382:microbiology*; D014230:Triazoles / Q000009:adverse effects / Q000494:pharmacology
chemical_list: D001565:Benzoates; D007502:Iron Chelating Agents; D011728:Pyridones; D014230:Triazoles; D000077543:Deferiprone; D003676:Deferoxamine; D000077588:Deferasirox