Investigating the effects of zinc oxide and titanium dioxide nanoparticles on the formation of biofilm and persister cells in Klebsiella pneumoniae

Abstract

The biofilm formation in klebsiella pneumoniae isolates poses a significant problem as it can result in treatment failure and the development of chronic infections. These biofilms act as protective barriers, rendering the bacteria resistant to antibiotics. Additionally, persister cells, which make up a small fraction of the bacterial population, have the ability to enter a dormant state after treatment with high doses of antibiotics. These persister cells play a crucial role in the high level of biofilm‐mediated tolerance to antibiotics. The present study aimed to investigate the impact of Zinc oxide (ZnO) and titanium dioxide (TiO2) nanoparticles on the formation of biofilm and persister cells in K. pneumoniae. The minimum inhibitory concentration (MIC) of colistin in K. pneumoniae ATCC 13883 was determined using the microdilution method. The formation of persister cells was evaluated by introducing sub‐MIC of colistin. Subsequently, the MIC of ZnO NPs and TiO2 NPs in these persister cells was assessed using the microdilution method. Furthermore, the effects of nanoparticles on the expression levels of biofilm‐associated genes were analyzed using real‐time polymer chain reaction (PCR). The MIC values for colistin, ZnO, and TiO2 were determined at 2, 12.5, and 6.25 μg/mL, respectively. In the presence of nanoparticles, biofilm formation decreased. Real‐time PCR results showed the messenger RNA (mRNA) level of mrkH and fimH were decreased and the expression of luxS and mazF were increased. Biofilm formation of K. pneumoniae ATCC 1383 was inhibited in response to nanoparticles. According to the results of the present study use of nanoparticles may help control multidrug‐resistant (MDR) infections in hospitalized patients.

TiO2 Nanocomposite Coatings and Inactivation of Carbapenemase-Producing Klebsiella Pneumoniae Biofilm—Opportunities and Challenges

“…They investigated the expression of genes in Klebsiella pneumoniae, which has a role in bacterial persistence, under nanoparticle exposure and compared it with the expression of untreated bacteria as a control. They showed that another antibiofilm mechanism of NPs can be the change in gene expression in biofilm production [26].…”

“…Intensive care units are mainly affected due to the multitude of maneuvers and invasive devices, but also due to the severity of the diagnoses of hospitalized patients and the large number of days of hospitalization [4,5,25]. Patients with bacteremia or respiratory infections due to carbapenemase-producing Klebsiella pneumoniae present a high death rate (30-70%) [4,5,25,26]. In our intensive care unit, we also face this major problem.…”

“…TiO 2 nanoparticles demonstrated an excellent antibiofilm activity against bacteria (including Klebsiella pneumoniae) and fungi (Candida albicans) [26,28]. TiO 2 NPs have been considered non-toxic materials compared with other metal oxides due to their inert nature.…”