title: The role of vancomycin in addition with colistin and meropenem against colistin-sensitive multidrug resistant Acinetobacter baumannii causing severe infections in a Paediatric Intensive Care Unit.
abstract: BACKGROUND
  Acinetobacter baumannii has been associated with high morbidity and mortality rates, even in pediatric patients. Therapeutic options are limited, especially when the strain is multidrug resistant.
  
  
  METHODS
  Clinical and microbiological analyses of 4 cases of systemic infections caused by multi drug resistant A. baumannii treated with colistin/vancomycin combination at a Pediatric Intensive Care Unit were performed in order to explore the potential synergistic activity of colistin plus vancomycin. All the patients were treated with colistin, meropenem and vancomycin.
  
  
  RESULTS
  Four severe infections due to MDR A. baumannii were observed. All patients treated with colistin/vancomycin combination had a positive outcome with no infection relapses. Most importantly, no significant adverse events related to the simultaneous administration of COL plus VAN were observed. In our in-vitro experiments, the synergistic effect of the combination COL plus VAN showed an early bactericidal activity even at VAN concentration of 16 mg/L, which reflects the serum trough concentrations obtained in patients.
  
  
  CONCLUSIONS
  An antimicrobial strategy based on the activity of colistin plus vancomycin was in-vitro and in-vivo effective in life-threatening infections caused by multidrug-resistant A. baumannii in a Pediatric Intensive Care Unit, in the absence of adverse effects. Colistin plus vancomycin were highly synergic and bactericidal against carbapenem-resistant, colistin sensitive A. baumannii whereas the addition of meropenem did not enhance the in-vitro activity of colistin plus vancomycin.
  
  
  CONCLUSIONS
  Our results confirm existing data on the potential synergistic activity of a therapeutic strategy including colistin plus vancomycin and provide important new clinical information for its potential use as a therapeutic option against MDR A. baumannii infections, especially in the pediatric population.
authors.affiliation: Department of Public Health and Infectious Diseases, University of Rome "Sapienza", Viale del Policlinico 155, Rome, Italy. giancarlo.ceccarelli@uniroma1.it.|Azienda Policlinico Umberto I, Viale del Policlinico 155, Rome, Italy. giancarlo.ceccarelli@uniroma1.it.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Ceccarelli
authors.affiliation: Department of Public Health and Infectious Diseases, University of Rome "Sapienza", Viale del Policlinico 155, Rome, Italy. alessandra.oliva@uniroma1.it.|Azienda Policlinico Umberto I, Viale del Policlinico 155, Rome, Italy. alessandra.oliva@uniroma1.it.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Oliva
authors.affiliation: Department of Public Health and Infectious Diseases, University of Rome "Sapienza", Viale del Policlinico 155, Rome, Italy. gabriella.dettorre@uniroma1.it.|Azienda Policlinico Umberto I, Viale del Policlinico 155, Rome, Italy. gabriella.dettorre@uniroma1.it.
authors.forename: Gabriella
authors.initials: G
authors.lastname: d'Ettorre
authors.affiliation: Department of Public Health and Infectious Diseases, University of Rome "Sapienza", Viale del Policlinico 155, Rome, Italy. alessandra.dabramo@libero.it.|Azienda Policlinico Umberto I, Viale del Policlinico 155, Rome, Italy. alessandra.dabramo@libero.it.
authors.forename: Alessandra
authors.initials: A
authors.lastname: D'Abramo
authors.affiliation: Pediatric Intensive Care Unit, Department of Pediatric Sciences, University of Rome "Sapienza", Viale del Policlinico 155, Rome, Italy. elencare@yahoo.it.|Azienda Policlinico Umberto I, Viale del Policlinico 155, Rome, Italy. elencare@yahoo.it.
authors.forename: Elena
authors.initials: E
authors.lastname: Caresta
authors.affiliation: Pediatric Intensive Care Unit, Department of Pediatric Sciences, University of Rome "Sapienza", Viale del Policlinico 155, Rome, Italy. dott.csbarbara@gmail.com.|Azienda Policlinico Umberto I, Viale del Policlinico 155, Rome, Italy. dott.csbarbara@gmail.com.
authors.forename: Caterina Silvia
authors.initials: CS
authors.lastname: Barbara
authors.affiliation: Department of Public Health and Infectious Diseases, University of Rome "Sapienza", Viale del Policlinico 155, Rome, Italy. mariateresa.mascellino@uniroma1.it.|Azienda Policlinico Umberto I, Viale del Policlinico 155, Rome, Italy. mariateresa.mascellino@uniroma1.it.
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Mascellino
authors.affiliation: Pediatric Intensive Care Unit, Department of Pediatric Sciences, University of Rome "Sapienza", Viale del Policlinico 155, Rome, Italy. p.papoff@libero.it.|Azienda Policlinico Umberto I, Viale del Policlinico 155, Rome, Italy. p.papoff@libero.it.
authors.forename: Paola
authors.initials: P
authors.lastname: Papoff
authors.affiliation: Pediatric Intensive Care Unit, Department of Pediatric Sciences, University of Rome "Sapienza", Viale del Policlinico 155, Rome, Italy. corrado.moretti@uniroma1.it.|Azienda Policlinico Umberto I, Viale del Policlinico 155, Rome, Italy. corrado.moretti@uniroma1.it.
authors.forename: Corrado
authors.initials: C
authors.lastname: Moretti
authors.affiliation: Department of Public Health and Infectious Diseases, University of Rome "Sapienza", Viale del Policlinico 155, Rome, Italy. vincenzo.vullo@uniroma1.it.|Azienda Policlinico Umberto I, Viale del Policlinico 155, Rome, Italy. vincenzo.vullo@uniroma1.it.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Vullo
authors.affiliation: Department of Science, Roma Tre University, Viale G. Marconi 446, Rome, Italy. paolo.visca@uniroma3.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: Visca
authors.affiliation: Department of Public Health and Infectious Diseases, University of Rome "Sapienza", Viale del Policlinico 155, Rome, Italy. mario.venditti@uniroma1.it.|Azienda Policlinico Umberto I, Viale del Policlinico 155, Rome, Italy. mario.venditti@uniroma1.it.
authors.forename: Mario
authors.initials: M
authors.lastname: Venditti
mesh_terms: D000151:Acinetobacter Infections / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D040981:Acinetobacter baumannii / Q000187:drug effects / Q000302:isolation & purification; D000328:Adult; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D015780:Carbapenems / Q000494:pharmacology; D003091:Colistin / Q000494:pharmacology / Q000627:therapeutic use*; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007223:Infant; D015278:Intensive Care Units, Pediatric; D008297:Male; D000077731:Meropenem; D008826:Microbial Sensitivity Tests; D013845:Thienamycins / Q000494:pharmacology / Q000627:therapeutic use*; D014640:Vancomycin / Q000494:pharmacology / Q000627:therapeutic use*; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; D013845:Thienamycins; D014640:Vancomycin; D000077731:Meropenem; D003091:Colistin