title: In vitro evaluation of synergistic activity between ciprofloxacin and broad snouted caiman serum against Escherichia coli.
abstract: The in vitro synergistic activity between ciprofloxacin and serum of broad snouted caiman on Escherichia coli was studied. The estimated MIC value of ciprofloxacin was 0.0188 µg/ml, and two assays of kill curve during 5 hours were performed: the first one in a standard culture medium and the second one in the presence of caiman serum. Different concentrations of ciprofloxacin were tested. Ciprofloxacin showed higher values of bacterial elimination rate in the presence of caiman serum in all concentrations tested. The combined activity of sub-inhibitory concentrations of ciprofloxacin and the humoral immune factors present in caiman serum determined an increase in the bacterial elimination observed in this assay. We suggest that the antibacterial activity of complement and natural antibodies present in caiman serum, which can bind to both Gram-negative and Gram-positive bacteria and acting through the classical complement pathway, can inhibit bacterial growth of Escherichia coli by lysis.
authors.affiliation: ICIVET-CONICET-Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, R.P. Kreder 2805, CP S3080HOF Esperanza, Santa Fe, Argentina; Laboratorio de Zoología Aplicada: Anexo Vertebrados (FHUC-UNL/MASPyMA) Departamento de ciencias Naturales, Facultad de Humanidades y Ciencias, Universidad Nacional del Litoral, Ciudad Universitaria -Paraje El Pozo, CP S3000 Santa Fe, Argentina. Electronic address: psiroski@fcv.unl.edu.ar.
authors.forename: P A
authors.initials: PA
authors.lastname: Siroski
authors.affiliation: Laboratorio de Bacteriología del Hospital de Salud Animal-Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, R.P. Kreder 2805, CP S3080HOF Esperanza, Santa Fe, Argentina.
authors.forename: N B
authors.initials: NB
authors.lastname: Russi
authors.affiliation: ICIVET-CONICET-Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, R.P. Kreder 2805, CP S3080HOF Esperanza, Santa Fe, Argentina.
authors.forename: H H
authors.initials: HH
authors.lastname: Ortega
authors.affiliation: Cátedra de Farmacología-Facultad de Ciencias Veterinarias, Universidad Nacional del Litoral, R.P. Kreder 2805, CP S3080HOF Esperanza, Santa Fe, Argentina.
authors.forename: E A
authors.initials: EA
authors.lastname: Formentini
mesh_terms: D000489:Alligators and Crocodiles / Q000097:blood*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002939:Ciprofloxacin / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects*; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D044967:Serum / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D002939:Ciprofloxacin
keywords: Caiman serum; Ciprofloxacin; Escherichia coli; Synergism; Zootechnical interest