CeO2 Nanoparticles Regulate the Propagation of Antibiotic Resistance Genes by Altering Cellular Contact and Plasmid Transfer

The spread of antibiotic resistance genes (ARG) occurs widely through plasmid transfer majorly facilitated via bacterial conjugation. To assess the spread of these mobile ARG, it is necessary to develop appropriate tools to estimate plasmid transfer rates under different environmental conditions. Process-based models are widely used for the estimation of plasmid transfer rate constants. Empirical studies have repeatedly highlighted the importance of subtle processes like delayed growth, the maturation of transconjugants, the physiological cost of plasmid carriage, and the dependence of conjugation on the culture′s growth stage. However, models used for estimating the transfer rates typically neglect them. We conducted virtual mating experiments to quantify the impact of these four typical structural model deficits on the estimated plasmid transfer rate constants. We found that under all conditions, the plasmid cost and the lag phase in growth must be taken into account to obtain unbiased estimates of plasmid transfer rate constants. We observed a tendency towards the underestimation of plasmid transfer rate constants when structurally deficient models were fitted to virtual mating data. This holds for all the structural deficits and mating conditions tested in our study. Our findings might explain an important component of the negative bias in model predictions known as the plasmid paradox. We also discuss other structural deficits that could lead to an overestimation of plasmid transfer rate constants and we demonstrate the impact of ill-fitted parameters on model predictions.

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Association of nanoparticles with extracellular genetic material and implications for the fate of antibiotic resistance genes in environmental systems

10.1021/scimeetings.0c07368 ◽

2020 ◽

Author(s):

Nadrat Chowdhury

Keyword(s):

Antibiotic Resistance ◽

Resistance Genes ◽

Genetic Material ◽

Antibiotic Resistance Genes ◽

Environmental Systems

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Quintuplex PCR to Detect Antibiotic Resistance Genes in Streptococcus pneumoniae

Journal of Clinical and Health Sciences ◽

10.24191/jchs.v2i1.5861 ◽

2016 ◽

Vol 1 (2) ◽

pp. 22 ◽

Cited By ~ 2

Author(s):

Navindra Kumari Palanisamy ◽

Parasakthi Navaratnam ◽

Shamala Devi Sekaran

Keyword(s):

Antibiotic Resistance ◽

Streptococcus Pneumoniae ◽

Resistance Genes ◽

Bacterial Pathogen ◽

Antibiotic Resistance Genes ◽

Pcr Amplification ◽

Penicillin Resistance ◽

Penicillin Binding Proteins ◽

Efflux Mechanism ◽

Mic Value

Introduction: Streptococcus pneumoniae is an important bacterial pathogen, causing respiratory infection. Penicillin resistance in S. pneumoniae is associated with alterations in the penicillin binding proteins, while resistance to macrolides is conferred either by the modification of the ribosomal target site or efflux mechanism. This study aimed to characterize S. pneumoniae and its antibiotic resistance genes using 2 sets of multiplex PCRs. Methods: A quintuplex and triplex PCR was used to characterize the pbp1A, ermB, gyrA, ply, and the mefE genes. Fifty-eight penicillin sensitive strains (PSSP), 36 penicillin intermediate strains (PISP) and 26 penicillin resistance strains (PRSP) were used. Results: Alteration in pbp1A was only observed in PISP and PRSP strains, while PCR amplification of the ermB or mefE was observed only in strains with reduced susceptibility to erythromycin. The assay was found to be sensitive as simulated blood cultures showed the lowest level of detection to be 10cfu. Conclusions: As predicted, the assay was able to differentiate penicillin susceptible from the non-susceptible strains based on the detection of the pbp1A gene, which correlated with the MIC value of the strains.

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