Susceptibility Tests and Predictions of Transporter Profile in Serratia Species.

Disinfectants and biosecurity are critically important to control microbial diseases. Resistance to disinfectants compromises sectors such as agriculture and healthcare systems. Currently, efflux pumps are the most common mechanism of antimicrobial resistance. This study aimed to identify the efflux transporters responsible for disinfectant resistance in a multidrug-resistant isolate Serratia sp. HRI compared to a susceptible Serratia sp. type strain. An efflux system profile was generated using the Transporter Automatic Annotation Pipeline (TransAAP) for both isolates. Thereafter, the efflux pump inhibitors, reserpine (RSP) and carbonyl cyanide 3-chlorophenylhydrazone (CCCP) were used to reveal the role of efflux pumps in susceptibility to three disinfectants (Didecyldimethylammonium chloride, HyperCide®, and benzalkonium chloride). Interestingly, the resistant isolate had fewer efflux systems in total compared to the type strain and fewer efflux systems classified as resistance efflux pumps. After the addition of RSP, a significant reduction in resistance capabilities against all three antimicrobials was observed for both isolates. However, CCCP supplementation produced mixed results with some outcomes suggesting the involvement of the Eagle effect. This study provides evidence that efflux pumps are responsible for the disinfectant resistance phenotype of the Serratia species due to the increased susceptibility when efflux pump inhibitors are added.

Genome Sequence of Resistant Serratia sp. Strain HRI, Isolated from a Bottle of Didecyldimethylammonium Chloride-Based Disinfectant.

Antimicrobial resistance is a significant issue, and it threatens the prevention and effective treatment of a range of bacterial infections. Here, we report the whole-genome sequence of the multidrug-resistant isolate Serratia sp. strain HRI. A hybrid assembly was created using sequences from a first (MiSeq) and second (PacBio) sequencing run. This work is imperative for understanding antimicrobial resistance and adds to the knowledge base for combating multidrug-resistant bacteria.

Molecular basis of bacterial disinfectant resistance.

Antibiotic resistance could accelerate humanity towards an already fast-approaching post-antibiotic era, where disinfectants and effective biosecurity measures will be critically important to control microbial diseases. Disinfectant resistance has the potential to change our way of life from compromising food security to threatening our medical health systems. Resistance to antimicrobial agents occurs through either intrinsic or acquired resistance mechanisms. Acquired resistance occurs through the efficient transfer of mobile genetic elements, which can carry single, or multiple resistance determinants. Drug resistance genes may form part of integrons, transposons and insertions sequences which are capable of intracellular transfer onto plasmids or gene cassettes. Thereafter, resistance plasmids and gene cassettes mobilize by self-transmission between bacteria, increasing the prevalence of drug resistance determinants in a bacterial population. An accumulation of drug resistance genes through these mechanisms gives rise to multidrug resistant (MDR) bacteria. The study of this mobility is integral to safeguard current antibiotics, disinfectants and other antimicrobials. Literature evidence, however, indicates that knowledge regarding disinfectant resistance is severly limited. Genome engineering such as the CRISPR-Cas system, has identified disinfectant resistance genes, and reversed resistance altogether in certain prokaryotes. Demonstrating that these techniques could prove invaluable in the combat against disinfectant resistance by uncovering the secrets of MDR bacteria.