Volume 13, Issue 2 (May 2025)
Res Mol Med (RMM) 2025, 13(2): 93-106 |
Back to browse issues page
Download citation:
BibTeX | RIS | EndNote | Medlars | ProCite | Reference Manager | RefWorks
Send citation to:
BibTeX | RIS | EndNote | Medlars | ProCite | Reference Manager | RefWorks
Send citation to:
Pourrahim S, Rabbani Khorasgani M, Shokri D, Beikzadeh B. Antibiotic Resistance of Klebsiella pneumonia Isolated From Inpatients and the Inhibitory Effect of Probiotics Against Metallo-β-lactamases-producing K. pneumonia. Res Mol Med (RMM) 2025; 13 (2) :93-106
URL: http://rmm.mazums.ac.ir/article-1-585-en.html
URL: http://rmm.mazums.ac.ir/article-1-585-en.html
1- Department of Cell and Molecular Biology & Microbiology, Faculty of Biological Science & Technology, University of Isfahan, Isfahan, Iran.
2- Department of Cell and Molecular Biology & Microbiology, Faculty of Biological Science & Technology, University of Isfahan, Isfahan, Iran. ,m.rabbani@biol.ui.ac.ir
3- Department of Cell and Molecular Biology & Microbiology, Faculty of Biological Science & Technology, Shahid Ashrafi University of Isfahan, Isfahan, Iran.
2- Department of Cell and Molecular Biology & Microbiology, Faculty of Biological Science & Technology, University of Isfahan, Isfahan, Iran. ,
3- Department of Cell and Molecular Biology & Microbiology, Faculty of Biological Science & Technology, Shahid Ashrafi University of Isfahan, Isfahan, Iran.
Abstract: (698 Views)
Background: Increased resistance to various antibiotics has challenged therapeutic options for the treatment of nosocomial infections, including infections caused by Klebsiella pneumoniae. Metallo-β-lactamase (MBL) producing K. pneumoniae is a serious concern due to its resistance to many antibiotics, including carbapenems, a class of last-resort antibiotics. This resistance is often encoded by genes such as blaIMP, blaVIM, and blaNDM, which are carried on plasmids, making them easily transmissible. The emergence and spread of MBL-producing K. pneumoniae strains is a rising threat, particularly in hospital settings, and can increase mortality, morbidity, and healthcare costs. This study investigates the inhibitory effect of commercial and native probiotics on these strains.
Materials and Methods In the present study, first, the resistance of 50 K. pneumoniae isolates from hospitalized patients in Isfahan hospitals, Isfahan City, Iran, to 11 antibiotics was determined according to the Clinical & Laboratory Standards Institute (CLSI) protocol. Subsequently, production of MBL enzymes was determined by the combined disks. Then, the blaNDM, blaVIM, and blaIMP genes were evaluated. Next, K. pneumoniae strains carrying plasmid-borne MBL genes were exposed to commercial FlorMidabil sachets manufactured in Italy. FlorMidabil sachets contained Bifidobacterium lactis, Lactobacillus acidophilus, Lactobacillus plantarum, and Lactobacillus paracasei, as well as standard native L. plantarum (PTCC1058) and Lactobacillus rhamnosus (PTCC1637). The goal was to investigate the inhibitory effect of these probiotics on K. pneumoniae strains. This study was conducted in three ways: The radial line method, the effects of probiotic supernatants, the effect of live probiotics on Klebsiella strains using the microtiter plate method, and the evaluation of K. pneumoniae viability in the presence of probiotics and re-culture on solid medium.
Results: All K. pneumoniae strains were resistant to the following antibiotics: meropenem, imipenem, ceftazidime, cefotaxime, cefepime, amikacin, gentamicin, cotrimoxazole, ciprofloxacin, and aztreonam. The results showed that the most effective antibiotic against the studied strains was colistin, a polymyxin. All strains carried plasmid-borne MBL genes, and blaNDM and blaIMP were confirmed, but blaVIM was not detected by polymerase chain reaction (PCR). According to the results, 37 isolates (74%) contained the blaNDM gene, and 13 isolates (26%) contained the blaIMP. This study is the first finding of K. pneumoniae carrying the blaNDM-5 gene in Iran. In the latter part of the study, it was identified that commercial probiotic sachets and standard native L. plantarum and L. rhamnosus had effects against the K. pneumoniae strain studied. The inhibitory effect of K. pneumoniae on the radial line method was observed in radial lines with or without slight growth in K. pneumoniae strains. In a co-culture method using probiotic bacteria with K. pneumoniae isolates, no significant change in optical density (OD) was observed after 24 h of incubation. However, in a liquid culture containing live probiotic bacteria and the K. pneumoniae strain, the increase in OD after 24 h was due to the growth of the probiotics. Considering the absorption rate on the second day in this experiment, it was found that native and standard probiotics of L. rhamnosus and L. plantarum had a lower inhibitory effect than commercial products. After cultivating wells containing probiotic and K. pneumoniae bacteria on solid medium, only small amounts of probiotic bacteria were recovered. As a result, cultivation of wells containing probiotic supernatants inoculated with K. pneumoniae did not result in growth.
Conclusion: The present study demonstrates the high frequency of K. pneumoniae strains with multiple resistance, high carbapenem resistance, and high blaNDM gene prevalence, which necessitate the identification and use of non-harmful alternative methods for their control and removal. Two L. plantaru and L. rhamnosus strains, as well as commercial probiotic products, are recommended.
Materials and Methods In the present study, first, the resistance of 50 K. pneumoniae isolates from hospitalized patients in Isfahan hospitals, Isfahan City, Iran, to 11 antibiotics was determined according to the Clinical & Laboratory Standards Institute (CLSI) protocol. Subsequently, production of MBL enzymes was determined by the combined disks. Then, the blaNDM, blaVIM, and blaIMP genes were evaluated. Next, K. pneumoniae strains carrying plasmid-borne MBL genes were exposed to commercial FlorMidabil sachets manufactured in Italy. FlorMidabil sachets contained Bifidobacterium lactis, Lactobacillus acidophilus, Lactobacillus plantarum, and Lactobacillus paracasei, as well as standard native L. plantarum (PTCC1058) and Lactobacillus rhamnosus (PTCC1637). The goal was to investigate the inhibitory effect of these probiotics on K. pneumoniae strains. This study was conducted in three ways: The radial line method, the effects of probiotic supernatants, the effect of live probiotics on Klebsiella strains using the microtiter plate method, and the evaluation of K. pneumoniae viability in the presence of probiotics and re-culture on solid medium.
Results: All K. pneumoniae strains were resistant to the following antibiotics: meropenem, imipenem, ceftazidime, cefotaxime, cefepime, amikacin, gentamicin, cotrimoxazole, ciprofloxacin, and aztreonam. The results showed that the most effective antibiotic against the studied strains was colistin, a polymyxin. All strains carried plasmid-borne MBL genes, and blaNDM and blaIMP were confirmed, but blaVIM was not detected by polymerase chain reaction (PCR). According to the results, 37 isolates (74%) contained the blaNDM gene, and 13 isolates (26%) contained the blaIMP. This study is the first finding of K. pneumoniae carrying the blaNDM-5 gene in Iran. In the latter part of the study, it was identified that commercial probiotic sachets and standard native L. plantarum and L. rhamnosus had effects against the K. pneumoniae strain studied. The inhibitory effect of K. pneumoniae on the radial line method was observed in radial lines with or without slight growth in K. pneumoniae strains. In a co-culture method using probiotic bacteria with K. pneumoniae isolates, no significant change in optical density (OD) was observed after 24 h of incubation. However, in a liquid culture containing live probiotic bacteria and the K. pneumoniae strain, the increase in OD after 24 h was due to the growth of the probiotics. Considering the absorption rate on the second day in this experiment, it was found that native and standard probiotics of L. rhamnosus and L. plantarum had a lower inhibitory effect than commercial products. After cultivating wells containing probiotic and K. pneumoniae bacteria on solid medium, only small amounts of probiotic bacteria were recovered. As a result, cultivation of wells containing probiotic supernatants inoculated with K. pneumoniae did not result in growth.
Conclusion: The present study demonstrates the high frequency of K. pneumoniae strains with multiple resistance, high carbapenem resistance, and high blaNDM gene prevalence, which necessitate the identification and use of non-harmful alternative methods for their control and removal. Two L. plantaru and L. rhamnosus strains, as well as commercial probiotic products, are recommended.
| Rights and permissions | |
 |
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. |
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC-By-NC), which permits use, distribution, and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
Contact Information
