0121 Haplotype analysis in ABC transporter genes and association of genetic variation in ABCB1, ABCC1, ABCC2, ABCC5 and ABCB4 with epilepsy outcome

Insecticides remain a main tool for the control of arthropod vectors. The urgency to prevent the insurgence of insecticide resistance and the perspective to find new target sites, for the development of novel molecules, are fuelling the study of the molecular mechanisms involved in insect defence against xenobiotic compounds. In this study, we have investigated if ATP-binding cassette (ABC) transporters, a major component of the defensome machinery, are involved in defence against the insecticide permethrin, in susceptible larvae of the malaria vector Anopheles gambiae sensu stricto. Bioassays were performed with permethrin alone, or in combination with an ABC transporter inhibitor. Then we have investigated the expression profiles of five ABC transporter genes at different time points following permethrin exposure, to assess their expression patterns across time. The inhibition of ABC transporters increased the larval mortality by about 15-fold. Likewise, three genes were up-regulated after exposure to permethrin, showing different patterns of expression across the 48 h. Our results provide the first evidences of ABC transporters involvement in defence against a toxic in larvae of An. gambiae s.s. and show that the gene expression response is modulated across time, being continuous, but stronger at the earliest and latest times after exposure.

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ATP-Binding Cassette (ABC) Transporter Genes in Plant-Parasitic Nematodes: An Opinion for Development of Novel Control Strategy

Frontiers in Plant Science ◽

10.3389/fpls.2020.582424 ◽

2020 ◽

Vol 11 ◽

Author(s):

Rinu Kooliyottil ◽

Koushik Rao Gadhachanda ◽

Nejra Solo ◽

Louise-Marie Dandurand

Keyword(s):

Abc Transporter ◽

Control Strategy ◽

Parasitic Nematodes ◽

Atp Binding ◽

Plant Parasitic Nematodes ◽

Abc Transporter Genes ◽

Plant Parasitic ◽

Atp Binding Cassette

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A Low-Affinity Penicillin-Binding Protein 2x Variant Is Required for Heteroresistance in Streptococcus pneumoniae

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.02547-14 ◽

2014 ◽

Vol 58 (7) ◽

pp. 3934-3941 ◽

Cited By ~ 14

Author(s):

Hansjürg Engel ◽

Moana Mika ◽

Dalia Denapaite ◽

Regine Hakenbeck ◽

Kathrin Mühlemann ◽

...

Keyword(s):

Streptococcus Pneumoniae ◽

Abc Transporter ◽

Binding Protein ◽

Population Analysis ◽

Resistance Testing ◽

Penicillin Binding Protein ◽

Secondary Resistance ◽

Content Type ◽

Abc Transporter Genes

ABSTRACTHeteroresistance to penicillin inStreptococcus pneumoniaeis the ability of subpopulations to grow at a higher antibiotic concentration than expected from the MIC. This may render conventional resistance testing unreliable and lead to therapeutic failure. We investigated the role of the primary β-lactam resistance determinants, penicillin-binding protein 2b (PBP2b) and PBP2x, and the secondary resistance determinant PBP1a in heteroresistance to penicillin. Transformants containing PBP genes from the heteroresistant strain Spain23F2349in the nonheteroresistant strain R6 background were tested for heteroresistance by population analysis profiling (PAP). We found thatpbp2x, but notpbp2borpbp1aalone, conferred heteroresistance to R6. However, a change ofpbp2xexpression was not observed, and therefore, expression does not correlate with an increased proportion of resistant subpopulations. In addition, the influence of the CiaRH system, mediating PBP-independent β-lactam resistance, was assessed by PAP onciaRdisruption mutants but revealed no heteroresistant phenotype. We also showed that the highly resistant subpopulations (HOM*) of transformants containing low-affinitypbp2xundergo an increase in resistance upon selection on penicillin plates that partially reverts after passaging on selection-free medium. Shotgun proteomic analysis showed an upregulation of phosphate ABC transporter subunit proteins encoded bypstS,phoU,pstB, andpstCin these highly resistant subpopulations. In conclusion, the presence of low-affinitypbp2xenables certain pneumococcal colonies to survive in the presence of β-lactams. Upregulation of phosphate ABC transporter genes may represent a reversible adaptation to antibiotic stress.

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