Joint effect of surfactants and cephalexin on the formation of Escherichia coli filament.
Ecotoxicol Environ Saf
; 199: 110750, 2020 Aug.
Article
en En
| MEDLINE
| ID: mdl-32446103
ABSTRACT
Both antibiotics and surfactants commonly exist in natural environment and have generated great concerns due to their biological influence on the ecosystem. A major concern lies in the capacity of antibiotics to induce bacterial filaments formation, which has potential health risks. However, their joint effect is not clear so far. Here, we studied the joint effect of cephalexin (Cex), a typical antibiotic, and differently charged surfactants on the formation of E. coli filaments. Three kinds of surfactants characterized by different charges were used cationic surfactant (CTAB), anionic surfactant (SDS) and nonionic surfactant (Tween). Data showed that Cex alone caused the formation of E. coli filaments, elongating their maximum profile from ca. 2 µm (a single E. coli cell) to tens of micrometers (an E. coli filament). A joint use of surfactants with Cex could produce even longer E. coli filaments, elongating the maximum length of the bacteria to larger than 100 µm. The capacity order of different surfactants under their optimum concentrations to produce elongated E. coli filaments was Tween > SDS > CTAB. The E. coli filaments were characterized with a normal DNA distribution and a good cell membrane integrity. We measured the stiffness of bacterial cell wall by atomic force microscopy and correlated the elongation capacity of the E. coli filaments to the stiffness of cell wall. Zeta potential measurement indicated that inserting into or being bound to the cell surface in a large quantity was tested not to be the major way that surfactants interacted with bacteria.
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Bases de datos:
MEDLINE
Asunto principal:
Polisorbatos
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Tensoactivos
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Cefalexina
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Contaminantes Ambientales
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Escherichia coli
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Antibacterianos
Idioma:
En
Revista:
Ecotoxicol Environ Saf
Año:
2020
Tipo del documento:
Article