Proteomic Analysis of the Enterococcus faecalis V583 Strain and Clinical Isolate V309 under Vancomycin Treatment

Abstract

To understand the molecular mechanisms of bacteria resistance to glycopeptides, we obtained proteomic profiles of vancomycin-resistant Enterococcus faecalis V583 (reference strain) and V309 (clinical isolate) passaged with and without the drug. The specificity and reversibility of vancomycin resistance genes induced in V583 and V309 were further studied over time. By semiquantitative RT-PCR of vancomycin-treated versus untreated samples of both strains, 28 (V583) or 20 (V309) up-regulated proteins, 8 (V583) or 6 (V309) down-regulated proteins, and 1 (V583) or 4 (V309) proteins with mobility changes in 2-DE gel analysis were identified. Some of these proteins have known vancomycin resistance functions or are related to virulent factors, stress, metabolism, translation, and conjunction, which would help Enterococcus survive under drug selection. Vancomycin induced specifically and reversibly VanA, VanX, VanB, and VanXB. Notably, 6 proteins (Pgm, Ldh, Gap-2, RpsB, EF2076, and sex pheromone cAD1 precursor lipoprotein) exhibited clear post-translational modifications. Vancomycin induced phosphorylation of Ser/Thr in Ldh, Gap-2, and sex pheromone cAD1 precursor lipoprotein (EF3256), newly identified here as enterococcal phosphoproteins. Our data suggest that phosphorylated EF3256 is normally active in E. faecelis, whereas EF3256-P together with oppA-like protein may play a key role in the regulation of pheromone and transmission of conjugation plasmids.

Proteomic characterization of van A-containing Enterococcu s recovered from Seagulls at the Berlengas Natural Reserve, W Portugal

“…The results are in accordance with previous results of Wang et al [19] that demonstrated that many proteins involved in antibiotic resistance were differentially regulated by vanomycin which also triggered innate signal regulators, adhesion factors, and metabolic gene expression in E. faecalis . Therefore, these responses may enable Enterococcus spp.…”

“…Over the past decade numerous genomes of pathogenic bacteria were fully sequenced and annotated, while others are continuously being sequenced and published. More recently to understand the molecular mechanisms of bacteria resistance to glycopeptides, proteomic profiles of vancomycin-resistant Enterococcus faecalis V583 (reference strain) and V309 (clinical isolate) were analysed [19]. Vancomycin induced specifically and reversibly VanA, VanX, VanB, and VanXB.…”

Comparative proteomic analysis of Lactobacillus plantarumfor the identification of key proteins in bile tolerance

“…Comparison of differentially expressed proteins within the same strain in different conditions have been performed, shedding light on bacterial adaptation factors to GI tract conditions, such as bile [13-16], acidic pH [18,19], and adhesion to the gut mucosa [20,21]. On the other hand, 2-DE coupled with mass spectrometry (MS) has been used to analyze bacterial protein polymorphisms and to distinguish between closely related pathogenic organisms [22-25], but this approach has rarely been employed to compare strains based on their probiotic features. We previously reported the first study of this kind which highlighted key proteins involved in the adhesion properties of Lactobacillus plantarum to mucin [12].…”

Survival proteomes: the emerging proteotype of antimicrobial resistance

“…These studies can elucidate a broader, more generalized, cellular response, but also specialized mechanisms that provide the most difficult to treat bacteria with their ability to survive when others do not. Comparisons of a vancomycin resistant clinical strain and a susceptible reference strain of Enterococcus faecalis showed that while many of the responses to antibiotic treatment were highly similar (suggesting a conserved adaptive responses), a group of specific resistance proteins showed differential abundance in the two strains in the presence or absence of antibiotic (Wang et al 2010). Specifically, VanA and VanX, which are involved in the production of peptidoglycan precursors with decreased glycopeptide-binding affinity (Arthur and Quintiliani 2001), were identified in the resistant strain in the absence of antibiotic, suggesting a prophylactic state of resistance.…”