Comparison of antibacterial activities of polymyxin B and colistin against multidrug resistant Gram negative bacteria

2019 ◽  
Vol 51 (9) ◽  
pp. 676-682 ◽  
Author(s):  
Mehmet Z. Doymaz ◽  
Elif Karaaslan
2019 ◽  
Vol 40 (6) ◽  
pp. 838-845 ◽  
Author(s):  
Ojas Jyoti Singh Pujji ◽  
Kiran Kishor Nakarmi ◽  
Basudha Shrestha ◽  
Shankar Man Rai ◽  
Steven Leonard Alexander Jeffery

AbstractIn Nepal, burn is the third most common injury after falls and road traffic accidents. Infection is the leading cause of mortality in burn injury. A profile exploring predominant flora and antimicrobial sensitivity is important to facilitate treatment ahead of microbiology results and to aid prevention of multidrug-resistant organisms. The aim of this study was to document epidemiological and bacteriological data of burn wound infections at a tertiary level burns center in Nepal. Samples were collected from January 2017 to May 2017, over a period of 5 months. Patient notes were referred to and information regarding baseline characteristics and burn wound infection data was collected. A total of 76 patients were included in the study during the 5-month period, which resulted in 113 samples being included for review. Females were injured most with burns 70% (n = 53) compared with males 30% (n = 23). Only 6 (8%) of 77 patients lived locally in Kathmandu. The average distance traveled by patients was 233 km (median 208, range 0–765, SD 181). Average TBSA% of burn was 22% (median 20, range 3–50, SD 12). Gram-negative organisms predominated, with Acinetobacter spp. in 42 cases (55%), Pseudomonas aeruginosa in 26 cases (34%), and Enterobacter spp. in 16 cases (21%). Colistin, polymyxin B, and tigecycline were found to be most sensitive covering 108, 98, and 94 organisms. Gram-negative bacteria colonized the majority of burn wounds. Colistin, polymyxin B, and tigecycline were the most sensitive to gram-negative bacteria. Gram-positive Staphylococcus aureus was sensitive most to vancomycin and tigecycline.


2016 ◽  
Vol 60 (5) ◽  
pp. 2671-2679 ◽  
Author(s):  
Mya Thandar ◽  
Rolf Lood ◽  
Benjamin Y. Winer ◽  
Douglas R. Deutsch ◽  
Chad W. Euler ◽  
...  

ABSTRACTAcinetobacter baumanniiis a Gram-negative bacterial pathogen responsible for a range of nosocomial infections. The recent rise and spread of multidrug-resistantA. baumanniiclones has fueled a search for alternative therapies, including bacteriophage endolysins with potent antibacterial activities. A common feature of these lysins is the presence of a highly positively charged C-terminal domain with a likely role in promoting outer membrane penetration. In the present study, we show that the C-terminal amino acids 108 to 138 of phage lysin PlyF307, named P307, alone were sufficient to killA. baumannii(>3 logs). Furthermore, P307 could be engineered for improved activity, the most active derivative being P307SQ-8C(>5-log kill). Both P307 and P307SQ-8Cshowed highin vitroactivity againstA. baumanniiin biofilms. Moreover, P307SQ-8Cexhibited MICs comparable to those of levofloxacin and ceftazidime and acted synergistically with polymyxin B. Although the peptides were shown to kill by disrupting the bacterial cytoplasmic membrane, they did not lyse human red blood cells or B cells; however, serum was found to be inhibitory to lytic activity. In a murine model ofA. baumanniiskin infection, P307SQ-8Creduced the bacterial burden by ∼2 logs in 2 h. This study demonstrates the prospect of using peptide derivatives from bacteriophage lysins to treat topical infections and remove biofilms caused by Gram-negative pathogens.


Author(s):  
Doriane E Djeussi ◽  
Jaurès AK Noumedem ◽  
Jackson A Seukep ◽  
Aimé G Fankam ◽  
Igor K Voukeng ◽  
...  

mBio ◽  
2017 ◽  
Vol 8 (5) ◽  
Author(s):  
Ganesh Krishnamoorthy ◽  
Inga V. Leus ◽  
Jon W. Weeks ◽  
David Wolloscheck ◽  
Valentin V. Rybenkov ◽  
...  

ABSTRACT Gram-negative bacteria are notoriously resistant to antibiotics, but the extent of the resistance varies broadly between species. We report that in significant human pathogens Acinetobacter baumannii, Pseudomonas aeruginosa, and Burkholderia spp., the differences in antibiotic resistance are largely defined by their penetration into the cell. For all tested antibiotics, the intracellular penetration was determined by a synergistic relationship between active efflux and the permeability barrier. We found that the outer membrane (OM) and efflux pumps select compounds on the basis of distinct properties and together universally protect bacteria from structurally diverse antibiotics. On the basis of their interactions with the permeability barriers, antibiotics can be divided into four clusters that occupy defined physicochemical spaces. Our results suggest that rules of intracellular penetration are intrinsic to these clusters. The identified specificities in the permeability barriers should help in the designing of successful therapeutic strategies against antibiotic-resistant pathogens. IMPORTANCE Multidrug-resistant strains of Gram-negative pathogens rapidly spread in clinics. Significant efforts worldwide are currently directed to finding the rules of permeation of antibiotics across two membrane envelopes of these bacteria. This study created the tools for analysis of and identified the major differences in antibacterial activities that distinguish the permeability barriers of P. aeruginosa, A. baumannii, Burkholderia thailandensis, and B. cepacia. We conclude that synergy between active efflux and the outer membrane barrier universally protects Gram-negative bacteria from antibiotics. We also found that the diversity of antibiotics affected by active efflux and outer membrane barriers is broader than previously thought and that antibiotics cluster according to specific biological determinants such as the requirement of specific porins in the OM, targeting of the OM, or specific recognition by efflux pumps. No universal rules of antibiotic permeation into Gram-negative bacteria apparently exist. Our results suggest that antibiotic clusters are defined by specific rules of permeation and that further studies could lead to their discovery. IMPORTANCE Multidrug-resistant strains of Gram-negative pathogens rapidly spread in clinics. Significant efforts worldwide are currently directed to finding the rules of permeation of antibiotics across two membrane envelopes of these bacteria. This study created the tools for analysis of and identified the major differences in antibacterial activities that distinguish the permeability barriers of P. aeruginosa, A. baumannii, Burkholderia thailandensis, and B. cepacia. We conclude that synergy between active efflux and the outer membrane barrier universally protects Gram-negative bacteria from antibiotics. We also found that the diversity of antibiotics affected by active efflux and outer membrane barriers is broader than previously thought and that antibiotics cluster according to specific biological determinants such as the requirement of specific porins in the OM, targeting of the OM, or specific recognition by efflux pumps. No universal rules of antibiotic permeation into Gram-negative bacteria apparently exist. Our results suggest that antibiotic clusters are defined by specific rules of permeation and that further studies could lead to their discovery.


2015 ◽  
Vol 1 (11) ◽  
pp. 568-575 ◽  
Author(s):  
Kade D. Roberts ◽  
Mohammad A. K. Azad ◽  
Jiping Wang ◽  
Andrew S. Horne ◽  
Philip E. Thompson ◽  
...  

2017 ◽  
Vol 9 (02) ◽  
pp. 081-083 ◽  
Author(s):  
Chinjal A. Panchal ◽  
Sweta Sunil Oza ◽  
Sanjay J. Mehta

Abstract CONTEXT: Metallo-β-lactamase (MBL)-producing bacteria lead to resistance to carbapenem an antibiotic that used as the last resort for treatment of multidrug-resistant bacteria, extended spectrum beta-lactamases, and AmpC β-lactamase-producing Gram-negative bacteria (GNB). The emergence of MBL-producing GNB is challenge to microbiology laboratories because there are no standardized guidelines available to detect them. The aim of this study was to compare four phenotypic methods to detect MBL production in GNB and to determine antibiotic sensitivity of MBL-producing isolates. MATERIALS AND METHODS: A total of 107 clinical isolates of GNB were tested for MBL production. Imipenem (IPM)-resistant GNB were taken as positive for MBL screening. MBL detection was done using ethylene diamine tetra acetic acid (EDTA) as MBL inhibitor. Four phenotypic methods were evaluated: (1) Combined disk synergy test (CDST) with 0.5M EDTA (CDST-0.5 M EDTA), (2) CDST with 0.1 M EDTA (CDST-0.1 M EDTA), (3) double-disk synergy test (DDST) with 0.5M EDTA (DDST-0.5 M EDTA), and (4) DDST with 0.1 M EDTA (DDST-0.1 M EDTA). RESULTS: Out of 107 GNB, 30 were resistant to IPM considered as screening positive. Out of 30, 21 (70%) isolates were MBL positive by CDST-0.1 M EDTA, 19 (63.33%) by CDST-0.5M EDTA, 17 (56.67%) by DDST-0.1 M EDTA, and 16 (53.33%) by DDST-0.5M EDTA. All MBL-producing Gram-negative Bacilli were resistant to ampicillin/sulbactam. Polymyxin B was found to be the most sensitive drug. CONCLUSION: CDST-0.1 M EDTA is the most sensitive method MBL detection. The detection of MBL-producing GNB is very important to control spread of the resistance.


Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1818 ◽  
Author(s):  
Anna Maria Schito ◽  
Silvana Alfei

Due to the rapid increase of antimicrobial resistance with ensuring therapeutic failures, the purpose of this study was to identify novel synthetic molecules as alternatives to conventional available, but presently ineffective antibiotics. Variously structured cationic dendrimers previously reported have provided promising outcomes. However, the problem of their cytotoxicity towards eukaryotic cells has not been completely overcome. We have now investigated the antibacterial activities of three not cytotoxic cationic dendrimers (G5Ds: G5H, G5K, and G5HK) against several multidrug-resistant (MDR) clinical strains. All G5Ds displayed remarkable activity against MDR non-fermenting Gram-negative species such as P. aeruginosa, S. maltophilia, and A. baumannii (MICs = 0.5–33.2 µM). In particular, very low MIC values (0.5–2.1 µM) were observed for G5K, which proved to be more active than the potent colistin (2.1 versus 3.19 µM) against P. aeruginosa. Concerning its mechanism of action, in time-killing and turbidimetric studies, G5K displayed a rapid non-lytic bactericidal activity. Considering the absence of cytotoxicity of these new compounds and their potency, comparable or even higher than that provided by the dendrimers previously reported, G5Ds may be proposed as promising novel antibacterial agents capable of overcoming the alarming resistance rates of several nosocomial non-fermenting Gram-negative pathogens.


2011 ◽  
Vol 56 (3) ◽  
pp. 1458-1465 ◽  
Author(s):  
Chao-Dong Qian ◽  
Xue-Chang Wu ◽  
Yi Teng ◽  
Wen-Peng Zhao ◽  
Ou Li ◽  
...  

ABSTRACTHospital-acquired infections caused by drug-resistant bacteria are a significant challenge to patient safety. Numerous clinical isolates resistant to almost all commercially available antibiotics have emerged. Thus, novel antimicrobial agents, specifically those for multidrug-resistant Gram-negative bacteria, are urgently needed. In the current study, we report the isolation, structure elucidation, and preliminary biological characterization of a new cationic lipopeptide antibiotic, battacin or octapeptin B5, produced from aPaenibacillus tianmuensissoil isolate. Battacin kills bacteriain vitroand has potent activity against Gram-negative bacteria, including multidrug-resistant and extremely drug-resistant clinical isolates. Hospital strains ofEscherichia coliandPseudomonas aeruginosaare the pathogens most sensitive to battacin, with MICs of 2 to 4 μg/ml. The ability of battacin to disrupt the outer membrane of Gram-negative bacteria is comparable to that of polymyxin B, the last-line therapy for infections caused by antibiotic-resistant Gram-negative bacteria. However, the capacity of battacin to permeate bacterial plasma membranes is less extensive than that of polymyxin B. The bactericidal kinetics of battacin correlate with the depolarization of the cell membrane, suggesting that battacin kills bacteria by disrupting the cytoplasmic membrane. Other studies indicate that battacin is less acutely toxic than polymyxin B and has potentin vivobiological activity againstE. coli. Based on the findings of the current study, battacin may be considered a potential therapeutic agent for the treatment of infections caused by antibiotic-resistant Gram-negative bacteria.


2018 ◽  
Vol 17 (3) ◽  
pp. 88-93 ◽  
Author(s):  
N. V. Dmitrieva ◽  
I. N. Petukhova ◽  
Z. V. Grigorievskaya ◽  
N. S. Bagirova ◽  
I. V. Тereshchenko ◽  
...  

The purpose of the study was to present data on polymixin-based antibiotics with activity against infections caused by multidrug- resistant Gram-negative bacteria, such as Acinetobacter baumannii,  Klebsiella pneumoniae, and Pseudomonas aeruginosa.Material and methods. The review includes data from clinical as well as in vitro studies for the period 1998–2017. The search for  relevant sources was carried out in the Medline, Cochrane Library, Elibrary and other databases.Results. The analysis of the data showed the presence of synergism and additive activity of polymyxin in combination with  carbapenems, rifampicin and azithromycin. However, experimental  data showed no direct positive correlation between combination of  polymyxim and azithromycin/ rifampicin. In clinical studies, in  hospital-acquired pneumonia, including ventilator-associated  pneumonia, the clinical response rate of polymyxin B combined with  other antibiotics ranged from 38 % to 88 %. High nephro-and  neurotoxicity of polymyxin observed in previous studies can be  explained by a lack of understanding of its toxicodynamics or the use of an incorrect dose.Conclusion. Polymyxin B in combination with other antibiotics is a promising treatment against infectious complications caused by multidrug resistant Gram-negative bacteria.


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