Antibiotics, Acid and Heat Tolerance of Honey adapted <i>Escherichia coli</i>, <i>Salmonella </i>Typhi and <i>Klebsiella pneumoniae</i>
oleh: Rabia Ayub, Muhammad Umer, Abid Aslam Maan, Bilal Rasool, Muhammad Kashif Iqbal Khan Tahira Younis, Shabbar Abbas, Muhammad Sajjad, Imdad Kaleem, Muhammad Imran, Azmat Ullah, Muhammad Sohail Afzal, Zaheer Hussain Shah, Sheraz Ahmed, Farhan Aslam, Neelam Chaudhary, Muhammad Inam Afzal
| Format: | Article |
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| Diterbitkan: | MDPI AG 2020-03-01 |
Deskripsi
The medicinal importance of honey has been known for many decades due to its antimicrobial properties against life-threatening bacteria. However, previous studies revealed that microorganisms are able to develop adaptations after continuous exposure to antimicrobial compounds. The present study was conducted to explore the impact of subinhibitory concentrations of branded honey (Marhaba) and unbranded honey (extracted from <i>Ziziphus mauritiana</i> plant) locally available in Pakistan on <i>Escherichia coli</i> ATCC 10536, <i>Salmonella </i>Typhi and <i>Klebsiella pneumoniae</i> by investigating the development of self- or cross-resistance to antibiotics (gentamicin, kanamycin and imipenem). Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of autoclaved honeys were determined. The bacterial cells of <i>E. coli</i> ATCC 10536, <i>S. </i>Typhi and <i>K. pneumoniae</i> were subjected to honey adaptation by exposing to ¼<i> × </i>MIC (4 passages) and ½<i> × </i>MIC (4 passages) of both honeys. Moreover, tolerance to low pH and high temperature was also studied in adapted and unadapted cells. The decreasing trend in growth pattern (OD<sub>600nm</sub>) of <i>E. coli</i> ATCC 10536, <i>S. </i>Typhi and <i>K. pneumoniae</i> was observed with increases in the concentration of honeys (6.25−50 % <i>v/v</i>) respectively. Our results showed that continuous exposure of both honeys did not lead to the development of any self- or cross-resistance in tested bacteria. However, percent survival to low pH was found to be significantly higher in adapted cells as compared to unadapted cells. The results indicate that both branded honey (Marhaba) and unbranded honey (extracted from <i>Ziziphus mauritiana</i> plant) were effective in controlling the growth of tested pathogenic bacteria. However, the emergence of tolerance to adverse conditions (pH 2.5, temperature 60 °C) deserves further investigation before proposing honey as a better antibacterial agent in food fabrication/processing, where low pH and high temperatures are usually implemented.