Bactericidal property of myrrh oil and two formulations against standard bacterial strains and multidrug-resistant clinical isolates with GC/MS chemical profiling

2019 ◽  
Author(s):  
NH Khalil ◽  
SM Fikry ◽  
OM Salama
2019 ◽  
Vol 6 ◽  
pp. 10-16 ◽  
Author(s):  
Tetiana Krupodorova ◽  
Victor Barshteyn ◽  
Elena Pokas

The antibacterial activity of Fomitopsis betulina cultural liquid (native, native concentrated, lyophilized, dried) against standard bacteria (Escherichia coli АТСС 25922, Pseudomonas aeruginosa АТСС 27853, Staphylococcus aureus АТСС 25923), and clinical isolates (Acinetobacter baumannii 50/1496 MBL, A. baumannii 88/2995 MBL, E. coli 116/3196 KPC, Klebsiella pneumoniae 6/509 ESBL, AmpC, KPC, P. aeruginosa 99/3066 MBL, P. aeruginosa 125/3343 MBL, S. haemoliticus 22/824 MRSA, S. aureus 134/3569 MRCNS) has been evaluated by the serial dilutions method. The antibacterial activity of F. betulina against S. haemoliticus and A. baumannii has been found for the first time. All samples of F. betulina cultural liquid demonstrated the inhibitory effect against standard bacterial strains at the minimum bactericidal concentration (MBC) ranging from >2.0 up to 18.75 mg/ml, and against multidrug-resistant clinical isolates with MBC from 7.8 up to 48.42 mg/ml. The dried F. betulina cultural liquid showed the highest antimicrobial activity against standard bacteria and clinical isolates, except A. baumannii 50/1496 MBL, while native concentrated cultural liquid was the most effective against this pathogen. The study showed that the antibacterial activity of the cultural liquid of F. betulina was improved by concentration and drying. The results obtained indicate that F. betulina cultural liquid contains alternative antimicrobial agents, useful for the treatment of bacterial diseases and might be a perspective substance for the pharmaceutical industries


Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5035
Author(s):  
Sandra Patricia Rivera-Sánchez ◽  
Helen Astrid Agudelo-Góngora ◽  
José Oñate-Garzón ◽  
Liliana Janeth Flórez-Elvira ◽  
Adriana Correa ◽  
...  

Antimicrobial resistance reduces the efficacy of antibiotics. Infections caused by multidrug-resistant (MDR), Gram-negative bacterial strains, such as Klebsiella pneumoniae (MDRKp) and Pseudomonas aeruginosa (MDRPa), are a serious threat to global health. However, cationic antimicrobial peptides (CAMPs) are promising as an alternative therapeutic strategy against MDR strains. In this study, the inhibitory activity of a cationic peptide, derived from cecropin D-like (ΔM2), against MDRKp and MDRPa clinical isolates, and its interaction with membrane models and bacterial genomic DNA were evaluated. In vitro antibacterial activity was determined using the broth microdilution test, whereas interactions with lipids and DNA were studied by differential scanning calorimetry and electronic absorption, respectively. A strong bactericidal effect of ΔM2 against MDR strains, with minimal inhibitory concentration (MIC) and minimal bactericidal concentrations (MBC) between 4 and 16 μg/mL, was observed. The peptide had a pronounced effect on the thermotropic behavior of the 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC)/1,2-dimyristoyl-sn-glycero-3-phosphorylglycerol (DMPG) membrane models that mimic bacterial membranes. Finally, the interaction between the peptide and genomic DNA (gDNA) showed a hyperchromic effect, which indicates that ΔM2 can denature bacterial DNA strands via the grooves.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nurul Diana Dzaraly ◽  
Mohd Nasir Mohd Desa ◽  
AbdulRahman Muthanna ◽  
Siti Norbaya Masri ◽  
Niazlin Mohd Taib ◽  
...  

AbstractPilus has been recently associated with pneumococcal pathogenesis in humans. The information regarding piliated isolates in Malaysia is scarce, especially in the less developed states on the east coast of Peninsular Malaysia. Therefore, we studied the characteristics of pneumococci, including the piliated isolates, in relation to antimicrobial susceptibility, serotypes, and genotypes at a major tertiary hospital on the east coast of Peninsular Malaysia. A total of 100 clinical isolates collected between September 2017 and December 2019 were subjected to serotyping, antimicrobial susceptibility test, and detection of pneumococcal virulence and pilus genes. Multilocus sequence typing (MLST) and phylogenetic analysis were performed only for piliated strains. The most frequent serotypes were 14 (17%), 6A/B (16%), 23F (12%), 19A (11%), and 19F (11%). The majority of isolates were resistant to erythromycin (42%), tetracycline (37%), and trimethoprim-sulfamethoxazole (24%). Piliated isolates occurred in a proportion of 19%; 47.3% of them were multidrug-resistant (MDR) and a majority had serotype 19F. This study showed ST236 was the most predominant sequence type (ST) among piliated isolates, which was related to PMEN clone Taiwan19F-14 (CC271). In the phylogenetic analysis, the piliated isolates were grouped into three major clades supported with 100% bootstrap values. Most piliated isolates belonged to internationally disseminated clones of S. pneumoniae, but pneumococcal conjugate vaccines (PCVs) have the potential to control them.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S655-S655
Author(s):  
Daniel Navas ◽  
Angela Charles ◽  
Amy Carr ◽  
Jose Alexander

Abstract Background The activity of imipenem/relebactam (I/R), ceftazidime/avibactam (CZA) and cefiderocol (FDC) were evaluated against clinical isolates of multidrug resistant (MDR) strains of P. aeruginosa which was resistant to ceftolozane/tazobactam (C/T). The recent increase of MDR P. aeruginosa strains isolated from clinical samples has prompted research and development of new antimicrobials that can withstand its multiple resistance mechanisms. C/T is an effective option for treatment of MDR P. aeruginosa in our facility with only 10% of resistance in MDR strains, but the emergence of resistance may occur due to the presence of a carbapenemase gene or an ampC mutation. Methods Antimicrobial susceptibility testing for C/T Etest® (bioMérieux, Inc.) were performed on all MDR strains initially screened by the VITEK2® (bioMérieux, Inc.). 10% (n=20) of all MDR isolates were resistant to C/T by the CLSI 2019 breakpoints. These resistant isolates were tested for presence of a carbapenemase gene using the GeneXpert CARBA-R (Cepheid®) PCR and against CZA Etest® (bioMérieux, Inc.) I/R gradient strips (Liofilchem®) and FDC broth microdilution (Thermo Scientific™ Sensititre™). Results A total of 20 clinical isolates of MDR P. aeruginosa resistant to C/T were tested following standardized CLSI protocols and techniques. All 20 isolates were screened for the presence of a carbapenemase gene (blaVIM, blaNDM, blaKPC, blaOXA-48, blaIMP). A blaVIM gene was detected in 6 (30%) out of 20 isolates. FDC demonstrated the greatest activity with 85% (n=17) of susceptible isolates (CLSI MIC <4µg/dL). CZA (CLSI MIC <8µg/dL) and I/R (FDA MIC <2µg/dL) showed 15% (n=3) and 10% (n=2) of susceptible isolates respectively. FDC was active against all 6 blaVIM isolates, where all 6 strains were resistant to CZA and I/R as expected. 3 isolates tested non-susceptible against FDC; additional characterization was not performed at this time. Conclusion Based on these results, FDC demonstrated the greatest in-vitro activity against C/T resistant strains of MDR P. aeruginosa. FDC also demonstrated activity against all 6 MDR P. aeruginosa carrying blaVIM gene. FDC is a strong option to consider on MDR P. aeruginosa strains based on a resistance testing algorithm and a cost/effective protocol. Disclosures All Authors: No reported disclosures


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