scholarly journals Down-regulation of biofilm-associated genes in mecA-positive methicillin-resistant S. aureus treated with M. communis extract and its antibacterial activity

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Moj Khaleghi ◽  
Sadegh Khorrami
Keyword(s):  
Biofilm Formation ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Ethanolic Extract ◽  
Multidrug Resistant ◽  
Clinical Samples ◽  
Bacterial Cells ◽  
Methicillin Resistant ◽  
Different Strains ◽  
Biofilm Development

AbstractConsidering the prevalence of resistance to antibiotics, the discovery of effective agents against resistant pathogens is of extreme urgency. Herein, 26 mecA-positive methicillin-resistant S. aureus (MRSA) isolated from clinical samples were identified, and their resistance to 11 antibiotics was investigated. Next, the antibacterial and anti-biofilm activity of the ethanolic extract of M. communis on these strains was evaluated. Furthermore, the effect of this extract on the expression of biofilm-associated genes, icaA, icaD, bap, sarA, and agr, was studied. According to the results, all isolated strains were multidrug-resistant and showed resistance to oxacillin and tetracycline. Also, 96.15 and 88.46 % of them were resistant to gentamicin and erythromycin. However, the extract could effectively combat the strains. The minimum inhibitory concentration (MIC) against different strains ranged from 1.56 to 25 mg/ml and the minimum bactericidal concentration (MBC) was between 3.125 and 50 mg/ml. Even though most MRSA (67 %) strongly produced biofilm, the sub-MIC concentration of the extract destroyed the pre-formed biofilm and affected the bacterial cells inside the biofilm. It could also inhibit biofilm development by significantly decreasing the expression of icaA, icaD, sarA and bap genes involved in biofilm formation and development. In conclusion, the extract inhibits biofilm formation, ruins pre-formed biofilm, and kills cells living inside the biofilm. Furthermore, it down-regulates the expression of necessary genes and nips the biofilm formation in the bud.

scholarly journals Fungal Extract of Lasiodiplodia pseudotheobromae IBRL OS-64 Inhibits the Growth of Skin Pathogenic Bacterium and Attenuates Biofilms of Methicillin-Resistant Staphylococcus aureus

2021 ◽  
Vol 28 (4) ◽  
pp. 24-36
Author(s):  
Mohd Taufiq Mat Jalil ◽  
Darah Ibrahim
Keyword(s):  
Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Cell Damage ◽  
Multidrug Resistant ◽  
Industrial Biotechnology ◽  
Bacterial Cells ◽  
Methicillin Resistant ◽  
Fungal Extract

Background: The emergence of multidrug-resistant pathogens associated with biofilm formation can cause life-threatening infections to humans. Therefore, the present study aims to evaluate the effects of the fungal extract of Lasiodiplodia pseudotheobromae (L. pseudotheobromae) Industrial Biotechnology Research Laboratory (IBRL) OS-64 on bacterial cells and the biofilm formation of methicillin-resistant Staphylococcus aureus (MRSA). Methods: Broth microdilution and semi-quantitative adherence assays were conducted to determine the anti-biofilm activity of the fungal extract. Light and scanning electron microscopy (SEM) analyses were performed to observe the effect of the fungal extract on biofilm formation by MRSA. Results: The transmission electron microscopy (TEM) microphotographs showed that the bacterial cells were severely damaged upon 24 h exposure to the extract and displayed several symptoms such as cell shrinkage and breakage. Meanwhile, results from the antibiofilm study indicated the extract attenuated the initial and preformed biofilms of MRSA by 80.82% and 61.39%, respectively. The initial biofilm was more sensitive to the extract compared to the pre-formed biofilm, as evidenced by the light microscopy and SEM observations that demonstrated more severe bacterial cell damage on the initial biofilms compared to pre-formed biofilms. Conclusion: The ethyl acetate extract of L. pseudotheobromae IBRL OS-64 significantly inhibited bacterial cells growth and eliminated biofilm formation by MRSA.

scholarly journals Antibacterial Activity of Lupinifolin from Derris reticulata and Its Effect on Cytoplasmic Membrane of Methicillin Resistant

2020 ◽  
Vol 17 (10) ◽  
pp. 1104-1112
Author(s):  
Kamol YUSOOK ◽  
Pettaya PANVONGSA
Keyword(s):  
Propidium Iodide ◽  
Nmr Spectra ◽  
Inhibitory Concentration ◽  
Cytoplasmic Membrane ◽  
Minimum Bactericidal Concentration ◽  
Membrane Integrity ◽  
Bacterial Cells ◽  
Liquid Chromatography Mass Spectrometry ◽  
Methicillin Resistant ◽  
Derris Reticulata

Lupinifolin from Derris reticulata Craib. was extracted with hexane by Soxhlet extractor and purified by crystallization. The yellow needle-shaped lupinifolin crystals were identified and confirmed by nuclear magnetic resonance (NMR) spectra and Liquid chromatography mass spectrometry (LC/MS). The lupinifolin showed minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of 8 and 16 µg/ml against Methicillin resistant S. aureus (MRSA), respectively. The flow cytometry (FCM) was performed to determine the alteration of cytoplasmic membrane (CM) permeability of MRSA by using Propidium iodide (PI) 5 µg/ml as an indicator for bacterial membrane integrity. It was found that the bacterial CM permeability was effected by lupinifolin with the MIC of 8 µg/ml comparable to the control when investigated by Propidium iodide intensity. Additionally, DNA laddering assay was carried out to evaluate apoptosis in bacterial cells. It was shown that the lupinifolin has no effect on DNA fragmentation.

scholarly journals Antiadhesion and antibiofilm potential of Fagonia indica from Cholistan desert against clinical multidrug resistant bacteria

2022 ◽  
Vol 82 ◽  
Author(s):  
N. Aslam ◽  
S. Hayat ◽  
T. Ali ◽  
M. Waseem ◽  
M. H. Siddique ◽  
...  
Keyword(s):  
Cell Wall ◽  
Minimum Inhibitory Concentration ◽  
Bacterial Cell ◽  
Biofilm Formation ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Antibacterial Effect ◽  
Multidrug Resistant ◽  
Chloroform Extract ◽  
Clinical Isolates

Abstract High resistance to antimicrobials is associated with biofilm formation responsible for infectious microbes to withstand severe conditions. Therefore, new alternatives are necessary as biofilm inhibitors to control infections. In this study, the antimicrobial and antibiofilm activities of Fagonia indica extracts were evaluated against MDR clinical isolates. The extract exhibited its antibiofilm effect by altering adherence and disintegration of bacterial cell wall. Fagonia indica has antibacterial effect as minimum inhibitory concentration (MIC) values ranging from 125 to 500 µg mL-1 and minimum bactericidal concentration (MBC) value was 500-3000 µg mL-1 against multidrug resistant (MDR) clinical isolates. The extract exhibited its antibiofilm effect by altering adherence and disintegration of bacterial cell wall. Fagonia indica had antibacterial effect as minimum inhibitory concentration (MIC) values ranging from 125 to 500 µg mL-1 and minimum bactericidal concentration (MBC) value was 500-3000 µg mL-1 against MDR isolates. The maximum inhibitory effects of Fagonia indica chloroform extract on biofilm formation was observed on Staphylococcus aureus (71.84%) followed by Klebsiella pneumoniae (70.83%) after 48 hrs showing that inhibition is also time dependent. Our results about bacterial cell protein leakage indicated that MDR isolates treated with chloroform extract of Fagonia indica showed maximum protein leakage of K. pneumoniae (59.14 µg mL-1) followed by S. aureus (56.7 µg mL-1). Cell attachment assays indicated that chloroform extract resulted in a 43.5-53.5% inhibition of cell adherence to a polystyrene surface. Our results revealed that extracts of Fagonia indica significantly inhibited biofilm formation among MDR clinical isolates, therefore, could be applied as antimicrobial agents and cost effective biofilm inhibitor against these MDR isolates.

scholarly journals IN VITRO STUDY OF URSOLIC ACID COMBINATION FIRST-LINE ANTITUBERCULOSIS DRUGS AGAINST DRUG-SENSITIVE AND DRUG-RESISTANT STRAINS OF Mycobacterium tuberculosis

2017 ◽  
Vol 10 (4) ◽  
pp. 216 ◽  
Author(s):  
Dian Ayu Eka Pitaloka ◽  
Elin Yulinah Sukandar
Keyword(s):  
Ursolic Acid ◽  
Drug Combination ◽  
Resistant Strain ◽  
Inhibitory Concentration ◽  
In Vitro Study ◽  
Antimycobacterial Activity ◽  
Multidrug Resistant ◽  
Minimum Concentration ◽  
Different Strains

Objective: The resurgence of tuberculosis (TB) caused by Mycobacterium TB (MTB) is associated with the rapid spread of multidrug-resistant,therefore, the development of new antimycobacterial agents is necessary. The aim of this study was to evaluate the antimycobacterial activity ofursolic acid (UA) when it using alone and combination with TB drugs.Methods: MTB H37Rv strain, streptomycin-rifampicin resistant strain, and isoniazid-ethambutol resistant strain were evaluated by susceptibility testusing a serial number of UA (25-150 µg/mL). Minimum inhibitory concentration (MIC) was read as minimum concentration of drugs that completelyinhibit visible growth of organism. Activities of drug combination of UA with TB drug were determined in Lowenstein-Jensen media by calculatingthe fractional inhibitory concentration index.Results: The results showed that MIC of UA was 50 µg/mL against three different strains of MTB. The combination of UA and TB drugs displayedsynergistic interaction, and no antagonism result from the combination was observed for strains of MTB.Conclusion: These results indicate that UA may serve as a promising lead compound for future antimycobacterial drug development.Keywords: Ursolic acid, Tuberculosis, Drug combination, Susceptibility test

scholarly journals Application of Bacteriophages on Shiga Toxin-Producing Escherichia coli (STEC) Biofilm

Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1423
Author(s):  
Nicola Mangieri ◽  
Roberto Foschino ◽  
Claudia Picozzi
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Antimicrobial Agents ◽  
Bacterial Cells ◽  
Abiotic Surfaces ◽  
Continuous Presence ◽  
Different Strains ◽  
Better Than

Shiga toxin-producing Escherichia coli are pathogenic bacteria able to form biofilms both on abiotic surfaces and on food, thus increasing risks for food consumers. Moreover, biofilms are difficult to remove and more resistant to antimicrobial agents compared to planktonic cells. Bacteriophages, natural predators of bacteria, can be used as an alternative to prevent biofilm formation or to remove pre-formed biofilm. In this work, four STEC able to produce biofilm were selected among 31 different strains and tested against single bacteriophages and two-phage cocktails. Results showed that our phages were able to reduce biofilm formation by 43.46% both when used as single phage preparation and as a cocktail formulation. Since one of the two cocktails had a slightly better performance, it was used to remove pre-existing biofilms. In this case, the phages were unable to destroy the biofilms and reduce the number of bacterial cells. Our data confirm that preventing biofilm formation in a food plant is better than trying to remove a preformed biofilm and the continuous presence of bacteriophages in the process environment could reduce the number of bacteria able to form biofilms and therefore improve the food safety.

The Staphylococcal Cassette Chromosome mec (SCCmec) Analysis and Biofilm Formation of Methicillin-Resistant Staphylococcus cohnii Isolated from Clinical Samples in Tehran, Iran

2021 ◽  
Vol 16 ◽  
Author(s):  
Somaye Delfani ◽  
Faranak Rezaei ◽  
Setareh Soroush ◽  
Pegah Shakib
Keyword(s):  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Antibiotic Resistance Genes ◽  
Mobile Element ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Coagulase Negative Staphylococci ◽  
Methicillin Resistant ◽  
Inducible Clindamycin Resistance ◽  
Sccmec Types

Background: Methicillin-resistant coagulase-negative staphylococci is responsible for hospital and community-acquired infections. Objective: This study aimed to investigate the antibiotic-resistance patterns, antibiotic-resistance genes, namely, ermA, ermB, ermC, blaZ, msrA, tetK, tetM, mup, and vanA, biofilm formation, and prevalence of different SCCmec types among the Staphylococcus cohniistrains isolated from clinical samples in Tehran, Iran. Methods: In this study,S. cohniiisolates were screened from the clinical samples from March 2012 to February 2013 in Tehran, Iran.Antimicrobial susceptibility test and inducible clindamycin resistance were evaluated by disc diffusion method, andresistance genes were examined using Polymerase Chain Reaction (PCR) assays. Then, biofilm formation assay was analyzed by Microtiter-plate test to detect the icaA and icaDgenes. The SCCmec and the Arginine Catabolite Mobile Element (ACME) typing were performed using the PCRmethod. Results: FromtwentyS. cohnii, all isolates were resistant to cefoxitin. 95% of the S. cohnii was defined as multidrug resistance (MDR)strains. The ermB, ermC, and vanA genes were not detected in any isolates; however, the blaZ gene had the highest frequency.95% of the S. cohnii isolates produced biofilm. Also, 4 SCCmec types, including V, IV, III+ (C2), VIII+ (AB1), were identified. Therefore, the majority of SCCmec were untypable. Based on the ACME typing, arcA and opp3 genes were positive in 13 (65%) and 1 (5%) isolates, respectively. Conclusion: Due to the high antimicrobial resistance and the spread of untypableSCCmecamong the isolates studied, the control and treatment of methicillin-resistantS. cohnii in hospitals and public health centers is a significant concern.

scholarly journals Biofilm Formation in Methicillin-Resistant Staphylococcus aureus Isolated in Cystic Fibrosis Patients Is Strain-Dependent and Differentially Influenced by Antibiotics

2021 ◽  
Vol 12 ◽  
Author(s):  
Agathe Boudet ◽  
Pauline Sorlin ◽  
Cassandra Pouget ◽  
Raphaël Chiron ◽  
Jean-Philippe Lavigne ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Multidrug Resistant ◽  
Inhibitory Effect ◽  
Ring Test ◽  
Methicillin Resistant ◽  
Lung Dysfunction ◽  
Chronic Colonization ◽  
Strain Dependent

Cystic fibrosis (CF) is a genetic disease with lung abnormalities making patients particularly predisposed to pulmonary infections. Staphylococcus aureus is the most frequently identified pathogen, and multidrug-resistant strains (MRSA, methicillin-resistant S. aureus) have been associated with more severe lung dysfunction leading to eradication recommendations. Diverse bacterial traits and adaptive skills, including biofilm formation, may, however, make antimicrobial therapy challenging. In this context, we compared the ability of a collection of genotyped MRSA isolates from CF patients to form biofilm with and without antibiotics (ceftaroline, ceftobiprole, linezolid, trimethoprim, and rifampicin). Our study used standardized approaches not previously applied to CF MRSA, the BioFilm Ring test® (BRT®), the Antibiofilmogram®, and the BioFlux™ 200 system which were adapted for use with the artificial sputum medium (ASM) mimicking conditions more relevant to the CF lung. We included 63 strains of 10 multilocus sequence types (STs) isolated from 35 CF patients, 16 of whom had chronic colonization. The BRT® showed that 27% of the strains isolated in 37% of the patients were strong biofilm producers. The Antibiofilmogram® performed on these strains showed that broad-spectrum cephalosporins had the lowest minimum biofilm inhibitory concentrations (bMIC) on a majority of strains. A focus on four chronically colonized patients with inclusion of successively isolated strains showed that ceftaroline, ceftobiprole, and/or linezolid bMICs may remain below the resistance thresholds over time. Studying the dynamics of biofilm formation by strains isolated 3years apart in one of these patients using BioFlux™ 200 showed that inhibition of biofilm formation was observed for up to 36h of exposure to bMIC and ceftaroline and ceftobiprole had a significantly greater effect than linezolid. This study has brought new insights into the behavior of CF MRSA which has been little studied for its ability to form biofilm. Biofilm formation is a common characteristic of prevalent MRSA clones in CF. Early biofilm formation was strain-dependent, even within a sample, and not only observed during chronic colonization. Ceftaroline and ceftobiprole showed a remarkable activity with a long-lasting inhibitory effect on biofilm formation and a conserved activity on certain strains adapted to the CF lung environment after years of colonization.

scholarly journals Trp-Containing Antibacterial Peptides Impair Quorum Sensing and Biofilm Development in Multidrug-Resistant Pseudomonas aeruginosa and Exhibit Synergistic Effects With Antibiotics

2021 ◽  
Vol 12 ◽  
Author(s):  
Dejing Shang ◽  
Xue Han ◽  
Wanying Du ◽  
Zhiru Kou ◽  
Fengquan Jiang
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibacterial Activity ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Efflux Pump ◽  
Synergistic Effects ◽  
Multidrug Resistant ◽  
Biofilm Development ◽  
Antibiotic Efflux

Pseudomonas aeruginosa uses quorum sensing (QS) to control virulence, biofilm formation and antibiotic efflux pump expression. The development of effective small molecules targeting the QS system and biofilm formation represents a novel attractive strategy. In this present study, the effects of a series of Trp-containing peptides on the QS-regulated virulence and biofilm development of multidrug-resistant P. aeruginosa, as well as their synergistic antibacterial activity with three classes of traditional chemical antibiotics were investigated. The results showed that Trp-containing peptides at low concentrations reduced the production of QS-regulated virulence factors by downregulating the gene expression of both the las and rhl systems in the strain MRPA0108. Biofilm formation was inhibited in a concentration-dependent manner, which was associated with extracellular polysaccharide production inhibition by downregulating pelA, algD, and pslA transcription. These changes correlated with alterations in the extracellular production of pseudomonal virulence factors and swarming motility. In addition, the combination of Trp-containing peptides at low concentration with the antibiotics ceftazidime and piperacillin provided synergistic effects. Notably, L11W and L12W showed the highest synergy with ceftazidime and piperacillin. A mechanistic study demonstrated that the Trp-containing peptides, especially L12W, significantly decreased β-lactamase activity and expression of efflux pump genes OprM, MexX, and MexA, resulting in a reduction in antibiotic efflux from MRPA0108 cells and thus increasing the antibacterial activity of these antibiotics against MRPA0108.

scholarly journals Understanding the Role of the Antioxidant Drug Erdosteine and Its Active Metabolite on Staphylococcus aureus Methicillin Resistant Biofilm Formation

Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1922
Author(s):  
Cristina Cattò ◽  
Federica Villa ◽  
Francesca Cappitelli
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Active Metabolite ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Major Effect ◽  
Total Proteins ◽  
Methicillin Resistant ◽  
Biofilm Development ◽  
Open Question

Increasing numbers of researches have suggested that some drugs with reactive oxygen species (ROS)-mediated mechanisms of action modulate biofilm formation of some pathogenic strains. However, the full contribution of ROS to biofilm development is still an open question. In this paper, the correlations between the antioxidant drug Erdosteine (Er) and its active Metabolite I (Met I), ROS and biofilm development of two strains of methicillin resistant Staphylococcus aureus are presented. Experiments revealed that Er and Met I at 2 and 5 mg/L increased up to three orders of magnitude the number of biofilm-dwelling cells, while the content of ROS within the biofilms was reduced above the 87%, with a major effect of Met I in comparison to Er. Comparative proteomics showed that, 5 mg/L Met I modified the expression of 30% and 65% of total proteins in the two strains respectively. Some proteins involved in cell replication were upregulated, and a nitric oxide-based mechanism is assumed to modulate the biofilm development by changing quorum sensitive pathways. Additionally, several proteins involved in virulence were downregulated in the presence of Met I, suggesting that treated cells, despite being greater in number, might have lost part of their virulence.

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