Transcriptomics Study on Staphylococcus aureus Biofilm Under Low Concentration of Ampicillin

Abstract

Staphylococcus aureus is one of the representative foodborne pathogens which forms biofilm. Antibiotics are widely applied in livestock husbandry to maintain animal health and productivity, thus contribute to the dissemination of antimicrobial resistant livestock and human pathogens, and pose a significant public health threat. Effect of antibiotic pressure on S. aureus biofilm formation, as well as the mechanism, remains unclear. In this study, the regulatory mechanism of low concentration of ampicillin on S. aureus biofilm formation was elucidated. The viability and biomass of biofilm with and without 1/4 MIC ampicillin treatment for 8 h were determined by XTT and crystal violet straining assays, respectively. Transcriptomics analysis on ampicillin-induced and non-ampicillin-induced biofilms were performed by RNA-sequencing, differentially expressed genes identification and annotation, GO functional and KEGG pathway enrichment. The viability and biomass of ampicillin-induced biofilm showed dramatical increase compared to the non-ampicillin-induced biofilm. A total of 530 differentially expressed genes (DEGs) with 167 and 363 genes showing up- and down-regulation, respectively, were obtained. Upon GO functional enrichment, 183, 252, and 21 specific GO terms in biological process, molecular function and cellular component were identified, respectively. Eight KEGG pathways including “Microbial metabolism in diverse environments”, “S. aureus infection”, and “Monobactam biosynthesis” were significantly enriched. In addition, “beta-lactam resistance” pathway was also highly enriched. In ampicillin-induced biofilm, the significant up-regulation of genes encoding multidrug resistance efflux pump AbcA, penicillin binding proteins PBP1, PBP1a/2, and PBP3, and antimicrobial resistance proteins VraF, VraG, Dlt, and Aur indicated the positive response of S. aureus to ampicillin. The up-regulation of genes encoding surface proteins ClfB, IsdA, and SasG and genes (cap5B and cap5C) which promote the adhesion of S. aureus in ampicillin induced biofilm might explain the enhanced biofilm viability and biomass.

Biofilm formation in bovine mastitis pathogens and the effect on them of antimicrobial drugs

“…http://www.ijmp.jor.br v. 10, n. 7, Special Edition PDATU 2019 ISSN: 2236-269X DOI: 10.14807/ijmp.v10i7.1012 mechanisms of bacterial survival is given special significance. It is established that 99% of microorganisms in natural ecosystems exist in the form of structured communities -biofilms (LIU, et al 2018;).…”

“…It is believed that the bacteria, present in the matrix of biofilm, are practically inaccessible to the action of antibiotics, despite the high sensitivity of the planktonic cells to these drugs. Thus, according to data (LIU et al, 2018), chronic inflammatory processes, in particular mastitis, are caused by microorganisms in a biofilm and traditional antibiotic therapy is ineffective. S. aureus has been reported to exhibit high ability to form a biofilm that is resistant to many antibiotics, including Methicillin (NEOPANE, et al, 2018).…”

“…Clinical features of infectious process of mastitis are largely due to the biological properties of microorganisms, namely -the presence of pathogenic and persistent potentials in them (LIU, et al 2018). In the last decade, the study of…”

Biofilm Production Ability, Virulence and Antimicrobial Resistance Genes in Staphylococcus aureus from Various Veterinary Hospitals

“…Performing a phenotypic and genotypic characterization of S. aureus for biofilm production and analyzing their relationship with antibiotic resistance will be important for understanding the treatment failure of infections caused by S. aureus. The crystal violet dye is widely used for in-vitro biofilm quantification due to its low cost and good reproducibility [26,27].…”

Unravelling interspecies interactions across heterogeneities in complex biofilm communities

“…A powerful tool for functional characterization of bacterial responses to environmental stimuli and changing conditions is the evaluation of gene expression profiles by sequencing the total pool of mRNA (RNA-seq) (Wang et al, 2009). Metatranscriptomic analysis has facilitated elucidation of differences in gene expressions caused by interspecies interactions (Moreno-Paz et al, 2010;Nakamura et al, 2016;Hansen et al, 2017) and has been used to evaluate transcriptomic profiles of mono-species biofilms (Liu et al, 2018a), defined mixed species consortia (Cheng et al, 2019) and complex oral biofilms (Jorth et al, 2014). Edlund and colleagues characterized the assembly and functionality of an in vitro oral biofilm over 24 h using parallel metagenomics and metatranscriptomics.…”