Agar plate-based biofilm of enterobacteria like Escherichia coli is characterized by expression of the extracellular matrix components amyloid curli and cellulose exopolysaccharide, which can be visually enhanced upon addition of the dye Congo Red, resulting in a red, dry, and rough (rdar) colony morphology. Expression of the rdar morphotype depends on the transcriptional regulator CsgD and occurs predominantly at ambient temperature in model strains. In contrast, commensal and pathogenic isolates frequently express the csgD-dependent rdar morphotype semi-constitutively, also at human host body temperature. To unravel the molecular basis of temperature-independent rdar morphotype expression, biofilm components and c-di-GMP turnover proteins of seven commensal and uropathogenic E. coli isolates were analyzed. A diversity within the c-di-GMP signaling network was uncovered which suggests alteration of activity of the trigger phosphodiesterase YciR to contribute to (up)regulation of csgD expression and consequently semi-constitutive rdar morphotype development.
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http://dx.doi.org/10.1002/mbo3.508 | DOI Listing |
Access Microbiol
November 2024
Departamento de Microbiologia, Universidade Federal de Viçosa (UFV), Av. Peter Henry Rolfs, Viçosa, 36570-900, Minas Gerais, Brazil.
Antibiotics (Basel)
November 2024
Department of Livestock and Pasture Science, University of Fort Hare, Alice 5700, South Africa.
Frequent use of colistin (COL) and tetracyclines in the Nigerian poultry sector potentially triggers bacterial resistance against COL and tigecycline (TIG), which are last-line antibiotics used to treat multidrug-resistant infections. This study aimed to isolate COL- and TIG-resistant . from commercial day-old chicks distributed to poultry farmers in Nsukka Southeastern Nigeria, assess the production of extended-spectrum β-lactamase (ESBL) and carbapenemase by the isolates, and establish their pathogenic potentials.
View Article and Find Full Text PDFBiofilm
December 2024
AIMES-Center for the Advancement of Integrated Medical and Engineering Sciences, Karolinska Institutet and KTH Royal Institute of Technology, SE-171 77, Stockholm, Sweden.
Urinary tract infections (UTI) caused by uropathogenic (UPEC) are a significant global health challenge. The UPEC biofilm lifestyle is believed to play an important role in infection recurrency and treatment resistance, but our understanding of how the extracellular matrix (ECM) components curli and cellulose contribute to biofilm formation and pathogenicity is limited. Here, we study the spatial and temporal development of native UPEC biofilm using agar-based detection methods where the non-toxic, optically active fluorescent tracer EbbaBiolight 680 reports the expression and structural location of curli in real-time.
View Article and Find Full Text PDFAntibiotics (Basel)
June 2024
Department of Veterinary Medicine, University of Perugia, 06126 Perugia, Italy.
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