scholarly journals INHIBITION OF BIOFILM PRODUCING GRAM NEGATIVE CLINICAL ISOLATES AND THEIR ANTIBIOGRAM PATTERN

2021 ◽  
Author(s):  
Ojaswee Shrestha ◽  
Nabina Shrestha ◽  
Sadhana Khanal ◽  
Sushant Pokhrel ◽  
Sujina Maharjan ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Bacterial Biofilm ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Antibiotics Resistance ◽  
Klebsiella Pneumonia ◽  
Isolation And Identification ◽  
Gram Negative ◽  
Biofilm Production

Background: Bacterial biofilm is a major virulence factor that posses a threat to patients leading to chronic infections. Therefore, it is crucial to identify biofilm production as well as their inhibition and reduction. This study was an attempt to investigate biofilm production among gram-negative isolates and assessment of inhibitory and reduction potential of EDTA and DMSO towards them and also observe the antimicrobial resistance pattern among biofilm producers and biofilm non-producer. Methods: Isolation and identification of bacterial isolates were performed by standard microbiological methodology. The antibiotic susceptibility pattern was determined by the Kirby Bauer disk diffusion method and β-lactamases by the combination disk method. Biofilm formation was detected through Tissue Culture Plate(TCP) method, and different concentrations of EDTA and DMSO were used to determine their inhibitory and reduction property against biofilm. Both inhibition and reduction by the various concentration of EDTA and DMSO were analyzed using paired t-test. Results: Among the 110 clinical isolates 61.8% were found to be Multidrug resistance(MDR) with the 33 (30%) produced Extended-spectrum β-lactamases(ESBL), 16 (14.5%)Metalloβ-lactamases(MBL) and 9 (8%)Klebsiella pneumonia carbapenemase(KPC). Biofilm formation was detected in 35.4% of isolates. Biofilm producing organisms showed antibiotics resistance to Cephalosporins, Chloramphenicol, Gentamycin, and Carbapenem. The inhibition and reduction of biofilm were significantly lower (p<0.05) for 1mM of EDTA and 2% of DMSO. Conclusions: EDTA and DMSO were found to possess potential activity against biofilm. Hence, EDTA and DMSO might be used invitro as an effective antibiofilm agent to control the biofilm-associated infection and for a possible therapeutic approach.

scholarly journals ANTIBIOGRAM PROFILE AND BIOFILM FORMING POTENTIAL OF PSEUDOMONAS SPECIES ISOLATED FROM VARIOUS CLINICAL SPECIMENS

2018 ◽  
Vol 11 (10) ◽  
pp. 150
Author(s):  
Jamsheera Cp ◽  
Ethel Suman
Keyword(s):  
Biofilm Formation ◽  
Susceptibility Testing ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Chi Square ◽  
Clinical Specimens ◽  
Medical College ◽  
Biofilm Production ◽  
Pseudomonas Species ◽  
Chi Square Test

Objective: The present study aimed at finding the resistance pattern of Pseudomonas aeruginosa and other Pseudomonas species isolated from various clinical specimens in the laboratory.Methods: A total of 150 isolates of different species of Pseudomonas obtained from various clinical specimens processed at the Microbiology laboratory of Kasturba Medical College, Manipal Academy of Higher Education, were taken for this study. Antibiotic susceptibility testing was performed by Kirby-Bauer disc diffusion method and interpreted according to the CLSI guidelines. Biofilm assay was performed by modified O’Toole and Kolter method. The results were analyzed using SPSS 17.0 and Student’s unpaired t-test, Kruskal–Wallis, Mann–Whitney, ANOVA, and Chi-square test. p<0.05 was considered statistically significant.Results: Increased resistance was observed by P. aeruginosa to cefotaxime, cotrimoxazole, levofloxacin, ofloxacin, and ticarcillin clavulanate. There was also a good correlation between antibiotic resistance to aztreonam, netilmicin, and ceftazidime and biofilm production. Results of the present study, therefore, demonstrated the occurrence of resistance to various antipseudomonal agents among the biofilm-producing P. aeruginosa isolates.Conclusion: The present study may help in assessing the seriousness of drug resistance caused by biofilm formation in P. aeruginosa and devise strategies through antibiotic policies to minimize such problems.

scholarly journals Molecular Investigation of Fibronectin-Binding Protein Genes and Capacity of Biofilm Production in Staphylococcus Aureus Isolated From Clinical Samples

2021 ◽  
Author(s):  
Hossein Jafari Soghondicolaei ◽  
Mohammad Ahanjan ◽  
Mehrdad Gholami ◽  
Bahman Mirzaei ◽  
Hamid Reza Goli
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Colorimetric Assay ◽  
Binding Protein ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Biofilm Production ◽  
Fibronectin Binding Protein ◽  
Fibronectin Binding

Abstract Biofilm production increases Staphylococcus aureus resistance to antibiotics and also host defense mechanisms. The current study aims to evaluate the biofilm formation by S. aureus and to determine the prevalence of fibronectin-binding protein genes, also its correlation with drug resistance. In this study, 100 clinical isolates of S. aureus were collected. The antibiotic susceptibility pattern of the isolates was evaluated by the disk agar diffusion method. The ability of biofilm formation in the studied isolates was also determined by microplate colorimetric assay. Then, all isolates were screened by polymerase chain reaction for the fnbA and fnbB genes. Out of 100 clinical isolates of S. aureus, the highest and lowest antibiotic resistance rates were against penicillin (94%) and vancomycin (6%). Thirty-two cases were found to be multi-drug resistant (MDR) among the all strains. The ability of biofilm production was observed in 89% of the isolates. The PCR results showed that the prevalence of fnbA and fnbB genes were 91% and 17%, respectively. Moreover, 100% and 21.8% of the MDR strains harbored the fnbA and fnbB genes respectively. The ability to form biofilm in MDR isolates of S. aureus is more than non-MDR isolates, especially fnbA positive ones. As the bacteria in the biofilm are difficult to kill by antibiotics, attention to the removal or control of the biofilm production seems to be necessary.

scholarly journals Evaluation of Antibiotic Resistance Pattern, Alginate and Biofilm Production in Clinical Isolates of Pseudomonas aeruginosa

2021 ◽  
Author(s):  
Fateme DAVARZANI ◽  
Navid SAIDI ◽  
Saeed BESHARATI ◽  
Horieh SADERI ◽  
Iraj RASOOLI ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Bacterial Resistance ◽  
Antimicrobial Agents ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Resistance Pattern ◽  
Alginate Production ◽  
Opportunistic Bacteria

Background: Pseudomonas aeruginosa is one of the most common opportunistic bacteria causing nosocomial infections, which has significant resistance to antimicrobial agents. This bacterium is a biofilm and alginate producer. Biofilm increases the bacterial resistance to antibiotics and the immune system. Therefore, the present study was conducted to investigate the biofilm formation, alginate production and antimicrobial resistance patterns in the clinical isolates of P. aeruginosa. Methods: One hundred isolates of P. aeruginosa were collected during the study period (from Dec 2017 to Jul 2018) from different clinical samples of the patients admitted to Milad and Pars Hospitals at Tehran, Iran. Isolates were identified and confirmed by phenotypic and genotypic methods. Antimicrobial susceptibility was specified by the disk diffusion method. Biofilm formation and alginate production were measured by microtiter plate and carbazole assay, respectively. Results: Sixteen isolates were resistant to all the 12 studied antibiotics. Moreover, 31 isolates were MultidrugResistant (MDR). The highest resistance rate was related to ofloxacin (36 isolates) and the least resistance was related to piperacillin-tazobactam (21 isolates). All the isolates could produce the biofilm and alginate. The number of isolates producing strong, medium and weak biofilms was equal to 34, 52, and 14, respectively. Alginate production was more than 400 μg/ml in 39 isolates, 250-400 μg/ml in 51 isolates and less than 250 μg/ml in 10 isolates. Conclusion: High prevalence of MDR, biofilm formation, and alginate production were observed among the clinical isolates of P. aeruginosa. The results also showed a significant relationship between the amount of alginate production and the level of biofilm formation.

scholarly journals Biofilm Formation and its Association with Antibiotic Susceptibility Pattern in Methicillin-resistant Staphylococcus aureus isolates

2021 ◽  
Author(s):  
Bajarangi Lal Chaudhary ◽  
Dakshina Bisht ◽  
Sameer Singh Faujdar
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Antibiotic Sensitivity ◽  
Diffusion Method ◽  
Beta Lactamase ◽  
Isolation And Identification ◽  
Methicillin Resistant ◽  
Clinical Specimens ◽  
Biofilm Production

Methicillin-resistant Staphylococcus aureus is a clinically significant pathogen that causes infections ranging from skin and soft tissue infections to life-threatening sepsis. Biofilm formation by MRSA is one of the crucial virulence factor. Determination of beta-lactamase and biofilm production among Staphylococcus aureus was obtained from various clinical specimens. Standard bacteriological procedures were used for isolation and identification and antibiotic sensitivity was determined using the Kirby Bauer disc diffusion method according to CLSI guidelines. The cloverleaf method, acidometric, iodometric and chromogenic methods were used to detect beta-lactamase while the microtiter plate method and Congo red agar method were used to detect biofilm production. Of the 288 MRSA strains isolated from various clinical specimens,198 (67.07%) were biofilm producers. Cloverleaf and chromogenic (nitrocefin) disc shows 100% results for beta-lactamase detection. Vancomycin was 100% sensitive followed by teicoplanin (92.36%) and linezolid (89.93%). Cloverleaf and nitrocefin disc methods were the most sensitive for detection of beta-lactamase in S. aureus and there was no significant relation between biofilm production and antibiotic sensitivity pattern of S. aureus.

scholarly journals Antibiotic resistance, biofilm formation, and biofilm-associated genes among Stenotrophomonas maltophilia clinical isolates

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Narjess Bostanghadiri ◽  
Abdollah Ardebili ◽  
Zohreh Ghalavand ◽  
Samane Teymouri ◽  
Mahsa Mirzarazi ◽  
...  
Keyword(s):  
Crystal Violet ◽  
Biofilm Formation ◽  
Staining Method ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Crystal Violet Staining ◽  
Disc Diffusion Method ◽  
Antimicrobial Susceptibility Pattern ◽  
Combination Strategies ◽  
Biofilm Production

Abstract Objective The purpose of the present study was to investigate the antimicrobial susceptibility pattern, biofilm production, and the presence of biofilm genes among the S. maltophilia clinical isolates. A total of 85 clinical isolates of S. maltophilia were collected from patients referred to several hospitals. Susceptibility to antibiotics was investigated by disc diffusion method according to the guidelines of the Clinical and Laboratory Standards Institute (CLSI). By the crystal violet staining method, the capability of biofilm formation was examined. The genes associated with biofilm production were investigated by the PCR-sequencing techniques. Results All isolates were resistant to doripenem, imipenem, and meropenem. Minocycline, trimethoprim/sulfamethoxazole and levofloxacin exhibited the highest susceptibility of 100%, 97.65%, and 95.29%, respectively. The results of crystal violet staining assay showed that all isolates (100%) form biofilm. Moreover, 24 (28.23%), 32 (37.65%), and 29 (34.12%) of isolates were categorized as weak, moderate, and strong biofilm producers, respectively. Biofilm genes including rpfF, spgM and rmlA had an overall prevalence of 89.41% (76/85), 100% (85/85) and 84.71% (72/85), respectively. Rational prescribing of antibiotics and implementation of infection control protocols are necessary to prevent further infection and development of antimicrobial resistance. Combination strategies based on the appropriate antibiotics along with anti-biofilm agents can also be selected to eliminate biofilm-associated infections.

scholarly journals Evaluation of bactericidal and anti-biofilm activities of silver nanoparticles against multidrug-resistant Gram-negative bacilli isolated from burn wound infections

2018 ◽  
Vol 14 (1) ◽  
pp. 72-77
Author(s):  
Issam Jumaa Nasser
Keyword(s):  
Escherichia Coli ◽  
Silver Nanoparticles ◽  
Biofilm Formation ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Klebsiella Pneumonia ◽  
Wound Infections ◽  
Burn Wound ◽  
Gram Negative ◽  
Bactericidal Effects

Background: The emergence and spread of multidrug-resistant Gram-negative bacilliin burn wound infections related to biofilm formation, which lend to challenge in treatment with conventional antibiotics andprompting to search for novel antimicrobial agents to control the infections.Silver nanoparticles (AgNPs) have wide spectrum biological properties with different mechanisms of action and less toxicity towards human cells. Objective:The goal of this study was to evaluated the anti-bacterial and anti-biofilm activities of AgNPs alone and in combination with aminoglycoside (Amikacin) and β-lactam (Ampicillin) antibiotics against multidrug resistant Gram-negative bacilli (Pseudomonas aeruginosa, Escherichia coli, klebsiellapneumoniae) isolated from burn wound infections. Type of the study: Cross –sectional study. Methods: 70   clinical isolates of GNBtested for susceptibility tests by disk diffusion method against 10 antibiotics. The minimum inhibitory concentrations (MICs) of AgNPs and antibiotics were carried out according to the standard broth microdilution method, while synergistic interactions were evaluated by time kill-kinetic assays.  Calgary method was applied for anti-biofilm activity. Results:Pseudomonas aeruginosa represented the majority of GNBisolated from burn wound infections 34 (48.5 %)followed by Klebsiella pneumonia 21 (30 %) and Escherichia coli 15 (21.5 %). Silver nanoparticles showed remarkable antibacterial activity against GNB that isolated from burn wound infections with the MICs between 25- 75 µg/ml.  Aztreonam, amikacin and cefepime were the most effective antimicrobial drugagainst GNB isolates.Synergistic bactericidal effects were observed in two-drug combinations of AgNPswith broad-spectrum aminoglycoside (Amikacin) and β-lactam (Ampicillin) antibiotics against multidrug resistant GNB. In addition,AgNPsalone or in combination with ampicillin inhibited biofilm activity about 60 % – 75 % ofGNB,while combination of AgNPs withamikacin exhibited a powerful anti-biofilm activity and inhibition biofilm formation by 75% to 80%. Conclusion: The results confirmed a synergistic bactericidal effects and significant enhancing of anti-biofilm activity of AgNPs in combination with antibiotics (amikacin and ampicillin) against multidrug resistant GNB isolated from burn wound infections. These data suggest that AgNPs could beapplied as nanodrug for treatment of burn wound infections

scholarly journals Antibiofilm and antivirulence potential of silver nanoparticles against multidrug-resistant Acinetobacter baumannii

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Helal F. Hetta ◽  
Israa M. S. Al-Kadmy ◽  
Saba Saadoon Khazaal ◽  
Suhad Abbas ◽  
Ahmed Suhail ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Microtiter Plate ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Infection Model ◽  
The Impact

AbstractWe aimed to isolate Acinetobacter baumannii (A. baumannii) from wound infections, determine their resistance and virulence profile, and assess the impact of Silver nanoparticles (AgNPs) on the bacterial growth, virulence and biofilm-related gene expression. AgNPs were synthesized and characterized using TEM, XRD and FTIR spectroscopy. A. baumannii (n = 200) were isolated and identified. Resistance pattern was determined and virulence genes (afa/draBC, cnf1, cnf2, csgA, cvaC, fimH, fyuA, ibeA, iutA, kpsMT II, PAI, papC, PapG II, III, sfa/focDE and traT) were screened using PCR. Biofilm formation was evaluated using Microtiter plate method. Then, the antimicrobial activity of AgNPs was evaluated by the well-diffusion method, growth kinetics and MIC determination. Inhibition of biofilm formation and the ability to disperse biofilms in exposure to AgNPs were evaluated. The effect of AgNPs on the expression of virulence and biofilm-related genes (bap, OmpA, abaI, csuA/B, A1S_2091, A1S_1510, A1S_0690, A1S_0114) were estimated using QRT-PCR. In vitro infection model for analyzing the antibacterial activity of AgNPs was done using a co-culture infection model of A. baumannii with human fibroblast skin cell line HFF-1 or Vero cell lines. A. baumannii had high level of resistance to antibiotics. Most of the isolates harbored the fimH, afa/draBC, cnf1, csgA and cnf2, and the majority of A. baumannii produced strong biofilms. AgNPs inhibited the growth of A. baumannii efficiently with MIC ranging from 4 to 25 µg/ml. A. baumannii showed a reduced growth rate in the presence of AgNPs. The inhibitory activity and the anti-biofilm activity of AgNPs were more pronounced against the weak biofilm producers. Moreover, AgNPs decreased the expression of kpsMII , afa/draBC,bap, OmpA, and csuA/B genes. The in vitro infection model revealed a significant antibacterial activity of AgNPs against extracellular and intracellular A. baumannii. AgNPs highly interrupted bacterial multiplication and biofilm formation. AgNPs downregulated the transcription level of important virulence and biofilm-related genes. Our findings provide an additional step towards understanding the mechanisms by which sliver nanoparticles interfere with the microbial spread and persistence.

scholarly journals Host Peptidic Hormones Affecting Bacterial Biofilm Formation and Virulence

2018 ◽  
Vol 11 (3) ◽  
pp. 227-241 ◽  
Author(s):  
Olivier Lesouhaitier ◽  
Thomas Clamens ◽  
Thibaut Rosay ◽  
Florie Desriac ◽  
Mélissande Louis ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Bacterial Biofilm ◽  
Critical Problem ◽  
Resistant Variant ◽  
Bacterial Physiology ◽  
Gram Positive Bacteria ◽  
Biofilm Production ◽  
The Impact ◽  
Original Approach ◽  
Antibacterial Potential

Bacterial biofilms constitute a critical problem in hospitals, especially in resuscitation units or for immunocompromised patients, since bacteria embedded in their own matrix are not only protected against antibiotics but also develop resistant variant strains. In the last decade, an original approach to prevent biofilm formation has consisted of studying the antibacterial potential of host communication molecules. Thus, some of these compounds have been identified for their ability to modify the biofilm formation of both Gram-negative and Gram-positive bacteria. In addition to their effect on biofilm production, a detailed study of the mechanism of action of these human hormones on bacterial physiology has allowed the identification of new bacterial pathways involved in biofilm formation. In this review, we focus on the impact of neuropeptidic hormones on bacteria, address some future therapeutic issues, and provide a new view of inter-kingdom communication.

scholarly journals Novel Method for The Valorization of Essential Oils From Orange By-Product

2021 ◽  
Author(s):  
Roudaina Abdel Samad ◽  
Karim Raafat ◽  
Alissar Al Khatib ◽  
Hadi Abou Chacra ◽  
nada EL DARRA
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Biofilm Formation ◽  
Bacterial Load ◽  
Minimum Energy ◽  
Bacterial Biofilm ◽  
Diffusion Method ◽  
Oil Composition ◽  
By Products ◽  
Orange Essential Oil

Abstract Background: A huge amount of citrus by-products are being wasted every year; these by-products can be used in the extraction of essential oils which can be used in different fields. Many methods have been used in the extraction of orange essential oil (E.O). This study focuses on the extraction of essential oil from orange by-product, using a newly developed extraction technique. This technique is a prototype combining a conventional method, namely, the hydrodistillation with the ultrasound-assisted extraction. Indeed, the traditional extraction methods of essential oils are time-consuming and expensive, moreover many organic compounds may decompose at high retained temperatures.Methods: a combination of traditional method with sonication improves efficiency and quality of the extraction, since ultrasonic extraction with precise and controlled operating parameters leads to higher extraction yields with minimum energy consumption. Therefore, the orange essential oil obtained using the prototype was compared to two commercial oils (CO1 and CO2) to create a valid comparison. Quality and safety tests have been performed, as well as bacterial load, antibacterial activities using the disc diffusion method, minimum inhibitory concentration (MIC), and prevention of bacterial biofilm formation.Results: As a result of extraction, the prototype method has shorten the extraction time, gave a higher quantity, and improved the extraction of essential oil from citrus peels without affecting oil composition when comparing it to hydrodistillation method. Conclusion: Orange E.O can be used as natural antibacterial agents to minimize bacterial growth, and inhibit biofilm formation by Staphylococcus aureus, Listeria monocytogenes and E.coli.

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