Alteration of Bacterial Antibiotic Sensitivity After Short-Term Exposure to Diagnostic Ultrasound

Abstract

BackgroundMany pathogenic bacteria show different levels of antibiotic resistance. Furthermore, a lot of hospital-acquired infections are caused by highly resistant or multidrug-resistant Gram-negative bacteria. According to WHO, patients with drug-resistant infections have higher morbidity and mortality. Moreover, patients infected with bacteria that are resistant to antibiotics considerably consume more healthcare resources.ObjectivesIn this study, we explored a physical method of converting drug-resistant bacteria to drug-sensitive ones.Materials and MethodsThis is an in vitro case-control study, performed at the Ionizing and Non-ionizing Radiation Protection Research Center (INIRPRC), Shiraz University of Medical Sciences (SUMS), Shiraz, Iran in 2014. All experiments were carried out using Gram-negative bacteria Klebsiella pneumonia and E. coli and Gram-positive Staphylococcus aureus and Streptococcus group A, isolated from hospitalized patients. The bacterial strains were obtained from the Persian Type Culture Collection, IROST, Iran (Klebsiella pneumonia PTCC 1290) and Bacteriology Department of Shahid Faghihi Teaching Hospital, Shiraz, Iran (E. coli, Staphylococcus aureus, and Streptococcus group A). The bacteria in culture plates were exposed to diagnostic ultrasound using a MyLab70XVG sonography system for 5 minutes. Then, the bacteria were cultured on Mueller-Hinton agar and incubated at 35°C for 18 hours. Finally, antibiotic susceptibility test was performed and the inhibition zone in both control and exposed groups were measured. Three replicate agar plates were used for each test and the inhibition zones of the plates were recorded.ResultsCompared with the results obtained from unexposed bacteria, statistically significant variations of sensitivity to antibiotics were found in some strains after short-term exposure. In particular, we found major differences (making antibiotic-resistant bacteria susceptible or vice versa) in the diameters of inhibition zones in exposed and non-exposed samples of Klebsiella pneumonia and Streptococcus.ConclusionsThis study clearly shows that short-term exposure of microorganisms to diagnostic ultrasonic waves can significantly alter their sensitivity to antibiotics. We believe that this physical method of making the antibiotic-resistant population susceptible can open new horizons in antibiotic therapy of a broad range of diseases, including tuberculosis.

Antibacterial Susceptibility Pattern of the Pseudomonas aeruginosa and Staphylococcus aureus after Exposure to Electromagnetic Waves Emitted from Mobile Phone Simulator

“…nitrofurantoin, nalidixic acid, and gentamicin antibiotics were used. The results showed that S. aureus was resistant to erythomycin and sensitive to vancomycin [27]. In this study, ultrasound waves altered the antimicrobial susceptibility in staphylococcus bacteria that is inconsistent with the present study findings.…”

Evaluation of the Effect of Radiofrequency Radiation Emitted From Wi-Fi Router and Mobile Phone Simulator on the Antibacterial Susceptibility of Pathogenic Bacteria Listeria monocytogenes and Escherichia coli

“…On the other hand, we have previously addressed the bioeffects of the exposure of bacteria to electromagnetic radiations and investigated different aspects of the challenging issue of the ionizing or nonionizing radiation-induced alterations in the susceptibility of microorganisms to antibiotics. 19,[32][33][34] In the current study, the pattern of the response of E coli to Wi-Fi and RF simulator radiation was identical. The maximum differences in the diameters of inhibition zones were observed between 6 and 9 hours of the bacterial exposure to radiation (Figures 1 and 2).…”

“…On the other hand, we have previously addressed the bioeffects of the exposure of bacteria to electromagnetic radiations and investigated different aspects of the challenging issue of the ionizing or nonionizing radiation-induced alterations in the susceptibility of microorganisms to antibiotics. 19 , 32 – 34…”

Sensitivity to Antibiotics of Bacteria Exposed to Gamma Radiation Emitted from Hot Soils of the High Background Radiation Areas of Ramsar, Northern Iran

“…Furthermore, we have previously reported that the observed decrease in diameter of the zone of inhibition in K. pneumoniae after exposure to mechanical ultrasound waves, can be explained as the induction of adaptive response. 13…”