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

作者：Mortazavi Seyed Mohammad Javad^*; Darvish Leili; Abounajmi Mohammad; Zarei Samira; Zare Tahereh; Taheri Mohammad; Nematollahi Samaneh

来源：Iranian Red Crescent Medical Journal, 2015, 17(11): e26622.

DOI：10.5812/ircmj.26622

• Drug Resistance
• Ultrasound
• Infection
• Antibiotics

Background: Many pathogenic bacteria show different levels of antibiotic resistance. Furthermore, a lot of hospital-acquired infections are caused by highly resistant or multid rug-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.
Objectives: In this study, we explored a physical method of converting drug-resistant bacteria to drug-sensitive ones.
Materials and Methods: This 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. cnli 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 degrees 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.
Results: Compared 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 majordifferences (making antibiotic-resistant bacteria susceptible or vice versa) in the diameters of inhibition zones in exposed and non-exposed samples of Klehsiella pneumonia and Streptococcus.
Conclusions: This 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.

• 出版日期2015-11