title: Biofilm formation on biotic and abiotic surfaces in the presence of antimicrobials by Escherichia coli Isolates from cases of bovine mastitis.
abstract: Escherichia coli is a highly adaptive microorganism, and its ability to form biofilms under certain conditions can be critical for antimicrobial resistance. The adhesion of four E. coli isolates from bovine mastitis to bovine mammary alveolar (MAC-T) cells, biofilm production on a polystyrene surface, and the expression profiles of the genes fliC, csgA, fimA, and luxS in the presence of enrofloxacin, gentamicin, co-trimoxazole, and ampicillin at half of the MIC were investigated. Increased adhesion of E. coli isolates in the presence of antimicrobials was not observed; however, increased internalization of some isolates was observed by confocal microscopy. All of the antimicrobials induced the formation of biofilms by at least one isolate, whereas enrofloxacin and co-trimoxazole decreased biofilm formation by at least one isolate. Quantitative PCR analysis revealed that all four genes were differentially expressed when bacteria were exposed to subinhibitory concentrations of antimicrobials, with expression altered on the order of 1.5- to 22-fold. However, it was not possible to associate gene expression with induction or reduction of biofilm formation in the presence of the antimicrobials. Taken together, the results demonstrate that antimicrobials could induce biofilm formation by some isolates, in addition to inducing MAC-T cell invasion, a situation that might occur in vivo, potentially resulting in a bacterial reservoir in the udder, which might explain some cases of persistent mastitis in herds.
authors: Divisão de Medicina Veterinária Preventiva e Saúde Pública, Departamento de Veterinária, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
authors: Vitor O
authors: VO
authors: Silva
authors: Divisão de Medicina Veterinária Preventiva e Saúde Pública, Departamento de Veterinária, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
authors: Larissa O
authors: LO
authors: Soares
authors: Divisão de Medicina Veterinária Preventiva e Saúde Pública, Departamento de Veterinária, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
authors: Abelardo
authors: A
authors: Silva Júnior
authors: Departamento de Microbiologia, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
authors: Hilário C
authors: HC
authors: Mantovani
authors: Animal Health Diagnostic Center, Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
authors: Yung-Fu
authors: YF
authors: Chang
authors: Divisão de Medicina Veterinária Preventiva e Saúde Pública, Departamento de Veterinária, Universidade Federal de Viçosa, Viçosa, MG, Brazil masm@ufv.br.
authors: Maria Aparecida S
authors: MA
authors: Moreira
mesh_terms: D000667:Ampicillin / Q000494:pharmacology; D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001422:Bacterial Adhesion / Q000187:drug effects*; D001426:Bacterial Proteins / Q000235:genetics; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D013437:Carbon-Sulfur Lyases / Q000235:genetics; D002417:Cattle; D000077422:Enrofloxacin; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology; D029968:Escherichia coli Proteins / Q000235:genetics; D005260:Female; D036781:Fimbriae Proteins / Q000235:genetics; D005408:Flagellin / Q000235:genetics; D024841:Fluoroquinolones / Q000494:pharmacology; D005839:Gentamicins / Q000494:pharmacology; D008321:Mammary Glands, Animal / Q000382:microbiology; D008414:Mastitis, Bovine / Q000188:drug therapy / Q000382:microbiology*; D008892:Milk / Q000382:microbiology*; D011137:Polystyrenes; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000494:pharmacology
chemical_list: D000890:Anti-Infective Agents; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C516095:FliC protein, E coli; D024841:Fluoroquinolones; D005839:Gentamicins; D011137:Polystyrenes; C489688:csgA protein, E coli; C063055:fimbrillin; D005408:Flagellin; D036781:Fimbriae Proteins; D000077422:Enrofloxacin; D000667:Ampicillin; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D013437:Carbon-Sulfur Lyases; C117753:LuxS protein, Bacteria