title: Antimicrobial susceptibility and emerging resistance determinants (blaCTX-M, rmtB, fosA3) in clinical isolates from urinary tract infections in the Bolivian Chaco.
abstract: BACKGROUND
  Bolivia is among the lowest-resourced South American countries, with very few data available on antibiotic resistance in bacterial pathogens. The phenotypic and molecular characterization of bacterial isolates responsible for urinary tract infections (UTIs) in the Bolivian Chaco are reported here.
  
  
  METHODS
  All clinical isolates from UTIs collected in the Hospital Basico Villa Montes between June 2010 and January 2014 were analyzed (N=213). Characterization included susceptibility testing, extended-spectrum beta-lactamase (ESBL) detection, identification of relevant resistance determinants (e.g., CTX-M-type ESBLs, 16S rRNA methyltransferases, glutathione S-transferases), and genotyping of CTX-M producers.
  
  
  RESULTS
  Very high resistance rates were observed. Overall, the lowest susceptibility was observed for trimethoprim-sulphamethoxazole, tetracycline, nalidixic acid, amoxicillin-clavulanic acid, ciprofloxacin, and gentamicin. Of E. coli and K. pneumoniae, 11.6% were ESBL producers. Resistance to nitrofurantoin, amikacin, and fosfomycin remained low, and susceptibility to carbapenems was fully preserved. CTX-M-15 was the dominant CTX-M variant. Four E. coli ST131 (two being H30-Rx) were identified. Of note, isolates harbouring rmtB and fosA3 were detected.
  
  
  CONCLUSIONS
  Bolivia is not an exception to the very high resistance burden affecting many South American countries. Optimization of alternative approaches to monitor local antibiotic resistance trends in resource-limited settings is strongly encouraged to support the implementation of effective empiric treatment guidelines.
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, Careggi University Hospital, Largo Brambilla 3, 50134 Florence, Italy; Infectious and Tropical Diseases Unit, Careggi University Hospital, Florence, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Bartoloni
authors.affiliation: Department of Medical Biotechnologies, University of Siena, Santa Maria alle Scotte University Hospital, Siena, Italy.
authors.forename: Samanta
authors.initials: S
authors.lastname: Sennati
authors.affiliation: Department of Medical Biotechnologies, University of Siena, Santa Maria alle Scotte University Hospital, Siena, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Di Maggio
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, Careggi University Hospital, Largo Brambilla 3, 50134 Florence, Italy.
authors.forename: Antonia
authors.initials: A
authors.lastname: Mantella
authors.affiliation: Department of Medical Biotechnologies, University of Siena, Santa Maria alle Scotte University Hospital, Siena, Italy.
authors.forename: Eleonora
authors.initials: E
authors.lastname: Riccobono
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, Careggi University Hospital, Largo Brambilla 3, 50134 Florence, Italy.
authors.forename: Marianne
authors.initials: M
authors.lastname: Strohmeyer
authors.affiliation: Instituto Nacional de Laboratorios de Salud "Dr. Nestor Morales Villazón" (INLASA), La Paz, Bolivia.
authors.forename: Carmen
authors.initials: C
authors.lastname: Revollo
authors.affiliation: Hospital Basico Villa Montes, Villa Montes, Bolivia.
authors.forename: Ana Liz
authors.initials: AL
authors.lastname: Villagran
authors.affiliation: Department of Medical Biotechnologies, University of Siena, Santa Maria alle Scotte University Hospital, Siena, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Pallecchi
authors.affiliation: Department of Experimental and Clinical Medicine, University of Florence, Careggi University Hospital, Largo Brambilla 3, 50134 Florence, Italy; Department of Medical Biotechnologies, University of Siena, Santa Maria alle Scotte University Hospital, Siena, Italy; Clinical Microbiology and Virology Unit, Careggi University Hospital, Florence, Italy. Electronic address: gianni.rossolini@gmail.com.
authors.forename: Gian Maria
authors.initials: GM
authors.lastname: Rossolini
mesh_terms: D019980:Amoxicillin-Potassium Clavulanate Combination / Q000627:therapeutic use*; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001838:Bolivia / Q000453:epidemiology; D024881:Drug Resistance, Bacterial / Q000187:drug effects* / Q000235:genetics; D004926:Escherichia coli / Q000302:isolation & purification*; D004927:Escherichia coli Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology; D029968:Escherichia coli Proteins / Q000187:drug effects / Q000235:genetics; D005578:Fosfomycin / Q000627:therapeutic use; D005838:Genotype; D006801:Humans; D007710:Klebsiella Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000302:isolation & purification*; D008780:Methyltransferases / Q000187:drug effects / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000187:drug effects / Q000235:genetics; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000627:therapeutic use*; D014552:Urinary Tract Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology*; D001618:beta-Lactamases / Q000187:drug effects / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D012336:RNA, Ribosomal, 16S; D005578:Fosfomycin; D019980:Amoxicillin-Potassium Clavulanate Combination; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D008780:Methyltransferases; C540682:RmtB protein, E coli; D001618:beta-Lactamases; C000602253:beta-lactamase CTX-M, E coli
keywords: Bolivia; CTX-M; FosA3; RmtB; ST131; Urinary tract infections