ADVERTISEMENT

Plasmid-Mediated Aminoglycosides Resistance Among Clinical Isolates Of Escherichia Coli

Escherichia coli is a component of the normal bacterial flora of the human digestive tract, but, on the other hand, it is an important opportunistic pathogen, which can cause infections at various locations such as the urinary tract, respiratory tract, or surgical sites. Treatment of these infections is becoming more and more difficult because of the increase in bacterial resistance against antibiotics and the reduction of therapeutic options.

One of the most prevalent mechanisms of resistance among E. coli isolates is the production of extended-spectrum β-lactamases (ESBLs), which determine resistance to β-lactam antibiotics. One of the therapeutic options for treating infections with such bacteria is aminoglycosides. Unfortunately, E. coli has developed effective resistance mechanisms against this group of antibiotics as well. It may be a result of antibiotic modification by enzymes, decreased intracellular drug accumulation, and the mutation of rRNA or the substitution of ribosomal proteins.

ADVERTISEMENT

One of the most prevalent mechanisms of resistance to aminoglycosides in E. coli is the production of aminoglycoside-modifying enzymes (AMEs). AMEs include acetyltransferases (ACC) which inactivate antibiotics by acetylation, O-nucleotidyltransferases (ANT) which cause the process of adenylation, and O-phosphotransferases (APH) which can phosphorylate aminoglycosides. It is worth noting that genes responsible for AMEs production often are contained within plasmids harboring also genes for ESBLs. The simultaneous resistance of E. coli against aminoglycosides as well as extended-spectrum cephalosporins remains a serious therapeutic challenge.

The changing epidemiology of ESBLs and aminoglycosides resistance was the reason why we decided to study the occurrence of the aph(3”)-Ib, ant(2”)-Ia, aac(6’)-Ib, aac (3)-Ia, and ant(4”)-IIa genes, responsible for AMEs production, among both ESBL-producing and  ESBL-non-producing E. coli isolates.

We evaluated the resistance phenotypes against aminoglycosides with the presence of genes responsible for this resistance. The study was prepared on 44 nonduplicated E. coli strains isolated from various clinical materials originated from patients hospitalized at University Hospital of Bialystok. Bacterial susceptibility to amikacin, gentamicin, netilmycin, and tobramycin was determined using  MIC values. Moreover, all isolates undergone analysis for the presence of the aph(3”)-Ib, ant(2”)-Ia, aac(6’)-Ib, aac (3)-Ia, and ant(4”)-IIa  genes with using of specific primers and the PCR technique.

In our study, we found that 79.5% of tested isolates presented resistance against aminoglycosides. The highest percentage of resistant strains (70.5%) was observed for tobramycin. The resistance of tested strains to gentamicin, netilmycin, and amikacin was at the level of 59%, 43.2%, and 11.4%, respectively. Moreover, the presence of aac(6’)-Ib gene was observed among 59.2% isolates, aph(3”)-Ib among 36.2%,  aac(3)-Ia among 15.9%, and ant(2”)-Ia among 4.6% isolates.

ADVERTISEMENT

Concluding, the aac(6’)-Ib and aph(3”)-Ib genes are mainly responsible for the enzymatic resistance of clinical isolates of E. coli to aminoglycosides.

These findings are described in the article entitled Genetic basis of enzymatic resistance of E. coli to aminoglycosides, recently published in the journal Advances in Medical Sciences. This work was conducted by Dominika Ojdana, Anna Sieńko,  Paweł Sacha, Piotr Majewski, Piotr Wieczorek, Anna Wieczorek, and Elżbieta Tryniszewska from the Medical University of Białystok, Poland.

Comments

READ THIS NEXT

Research Finds Possible Root Cause Of Pessimism

Research done by a team of scientists at MIT has identified a possible source for pessimistic reactions and negative moods […]

New Study On CBD, A Marijuana Extract, Shows Signs Of Easing Anxiety

Marijuana is slowly becoming legal in some forms across the United States. Emerging research is showing that the components of […]

London Fights Its Plastic Problem: New Fountains And Bottle-Refill Stations Around The City

From plastic bags to plastic containers, plastic is an integrated part of our lives. Since its development in 1907, we […]

Capturing The Complexity Of Geologic Carbon Sequestration In Complex Basalt Formations

Global carbon dioxide (CO2) emissions from energy production declined each year between 2013 and 2016, but this trend ended abruptly […]

Benadryl For Dogs: Dosage And Safety Information

Benadryl can be used for dogs, and the recommended dosage is typically about 1 milligrams per pound of body weight […]

5 Best IQ Tests: Find Out Your IQ For Free (And Kids)

There are many different IQ tests available to measure one’s intelligence, but they cost money. Luckily, there are also IQ […]

Intriguing Flexible Devices Based On Mechanoluminescence

Mechanoluminescence (ML), also called triboluminescence (TL), refers to the phenomenon/process that materials could emit light under mechanical stimuli, e.g., friction, […]

Science Trends is a popular source of science news and education around the world. We cover everything from solar power cell technology to climate change to cancer research. We help hundreds of thousands of people every month learn about the world we live in and the latest scientific breakthroughs. Want to know more?