Development of Quinoxaline 1, 4-Dioxides Resistance in Escherichia coli and Molecular Change under Resistance Selection

Abstract

Quinoxaline 1, 4-dioxides (QdNOs) has been used in animals as antimicrobial agents and growth promoters for decades. However, the resistance to QdNOs in pathogenic bacteria raises worldwide concern but it is barely known. To explore the molecular mechanism involved in development of QdNOs resistance in Escherichia coli, 6 strains selected by QdNOs in vitro and 21 strains isolated from QdNOs-used swine farm were subjected to MIC determination and PCR amplification of oqxA gene. A conjugative transfer was carried out to evaluate the transfer risk of QdNOs resistant determinant. Furthermore, the transcriptional profile of a QdNOs-resistant E. coli (79O4-2) selected in vitro with its parent strain 79–161 was assayed with a prokaryotic suppression subtractive hybridization (SSH) PCR cDNA subtraction. The result showed that more than 95% (20/21) clinical isolates were oqxA positive, while all the 6 induced QdNOs-resistant strains carried no oqxA gene and exhibited low frequency of conjugation. 44 fragments were identified by SSH PCR subtraction in the QdNOs-resistant strain 79O4-2. 18 cDNAs were involved in biosynthesis of Fe-S cluster (narH), protein (rpoA, trmD, truA, glyS, ileS, rplFCX, rpsH, fusA), lipoate (lipA), lipid A (lpxC), trehalose (otsA), CTP(pyrG) and others molecular. The 11 cDNAs were related to metabolism or degradation of glycolysis (gpmA and pgi) and proteins (clpX, clpA, pepN and fkpB). The atpADG and ubiB genes were associated with ATP biosynthesis and electron transport chain. The pathway of the functional genes revealed that E. coli may adapt the stress generated by QdNOs or develop specific QdNOs-resistance by activation of antioxidative agents biosynthesis (lipoate and trehalose), protein biosynthesis, glycolysis and oxidative phosphorylation. This study initially reveals the possible molecular mechanism involved in the development of QdNOs-resistance in E. coli, providing with novel insights in prediction and assessment of the emergency and horizontal transfer of QdNOs-resistance in E. coli.

Integrated OMICS guided engineering of biofuel butanol-tolerance in photosynthetic Synechocystissp. PCC 6803

“…Moreover, metabolomic analysis showed the increased abundances of intermediates in the glycolysis pathway, such as glucose-6-P and 3-PG, consistent with the induction of two key genes, slr0752 encoding phosphopyruvate hydratase and sll0745 encoding 6-phosphofructokinase in the glycolysis pathway. Consistent with this result, up-regulation of glycolysis has been reported for various microbes under stress condition [56,57]. In a recent 13 C-based flux analysis, a thermophilic ethanol-tolerant Geobacillus thermoglucosidasius M10EXG was found to prefer glycolysis, the pentose phosphate pathway and the TCA cycle for glucose metabolism [58].…”

Quinoxaline 1,4-di-N-Oxides: Biological Activities and Mechanisms of Actions

“…In addition to OLA and chloramphenicol, the OqxAB pump conferred antimicrobial resistance or reduced susceptibility toward a variety of substrates in E. coli , including animal growth promoters, antimicrobials, disinfectants and detergents ( Hansen et al, 2007 ). Interestingly, oqxA gene was not detected in the CYA/OLA- resistant E. coli induced in vitro ( Guo et al, 2012 ), suggesting there are other mechanisms conferring the bacterial resistance.…”

GADD45a Regulates Olaquindox-Induced DNA Damage and S-Phase Arrest in Human Hepatoma G2 Cells via JNK/p38 Pathways

“…Quinoxaline 1,4-dioxides (QdNOs) consisting of one or two acyclic chain moieties ( Figure 1 A), have many biological properties, such as antimicrobial, antitumora and anti-inflammatory actions [ 1 , 2 , 3 ]. Olaquindox ( Figure 1 B) is one of the QdNOs family and it has been mainly used as a growth promotant.…”