scholarly journals CORRELATE BETWEEN BIOFILM FORMATION AND AZOLE ANTIFUNGAL SUSCEPTIBILITY AGAINST PLANKTONIC AND SESSILE CANDIDA ALBICANS CLINICAL ISOLATES

2021 ◽  
Vol 71 (3) ◽  
pp. 1089-93
Author(s):  
Saira Salim ◽  
Raja Kamran Afzal ◽  
Shahzad Hassan ◽  
Aamir Ikram ◽  
Amir Hussain ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Antifungal Susceptibility ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Military Hospital ◽  
Dilution Method ◽  
P Value ◽  
Disk Diffusion Method ◽  
Broth Microdilution Method ◽  
Dose Dependent

Objective: To assess the correlation between biofilm formation and azole antifungal susceptibility against plank tonic and sessile clinical isolates of C.albicans. Study Design: Prospective observational study. Place and Duration of Study: Combined Military Hospital Peshawar, from Jun 2016 to Sep 2017. Methodology: All standard microbiological procedures were carried out according to latest Clinical & laboratory standard institute (CLSI) guidelines. After gram staining and presumptive identification on CHRO Magar Candida, the isolates were biochemically identified by API AUX Candida as C.albicans. Planktonic antifungal susceptibility was carried out by Kirby Bauer disk diffusion method on 300 C.albicans isolates. Broth microdilution method was used to determine Minimum inhibitory concentration (MICs) of plank tonic cells and micro titer assay was used for assessment of biofilm formation by C.albicans. Results: In planktonic antifungal susceptibility, fluconazole was susceptible against 195 (65%) and voriconazole against 241 (80%) C. albicans isolates. C. albicans was found susceptible dose dependent (SDD) to fluconazole in 28 (9%) and to voriconazole in 21 (7%) isolates. Seventy-seven (26%) and 38 (13%) C.albicans isolates were found fluconazole and voriconazole resistant, respectively. Sessile antifungal susceptibility was carried out through broth micro dilution method in which 160 (53%) were susceptible, 42 (14%) were susceptible dose dependent SDD and 98 (33%) were resistance to voriconazole, and 161 (54%) were susceptible, 36 (12%) were SDD and 103 (34%) were found resistant to fluconazole. Biofilm forming isolates of C.albicans were observed to be 285 (95%).The p-value is highly significance i.e. <0.01 between......

scholarly journals Correlation of biofilm formation and antibiotic resistance among clinical and soil isolates of Acinetobacter baumannii in Iraq

2019 ◽  
pp. 1-10 ◽  
Author(s):  
Pakhshan A. Hassan ◽  
Adel K. Khider
Keyword(s):  
Acinetobacter Baumannii ◽  
Congo Red ◽  
Biofilm Formation ◽  
Opportunistic Pathogen ◽  
Microtiter Plate ◽  
Test Tube ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Biochemical Tests ◽  
Disk Diffusion Method

Acinetobacter baumannii is an opportunistic pathogen that is reported as a major cause of nosocomial infections. The aim of this study was to investigate the biofilm formation by A. baumannii clinical and soil isolates, to display their susceptibility to 11 antibiotics and to study a possible relationship between formation of biofilm and multidrug resistance. During 8 months period, from June 2016 to January 2017, a total of 52 clinical and 22 soil isolates of A. baumannii were collected and identified through conventional phenotypic, chromo agar, biochemical tests, API 20E system, and confirmed genotypically by PCR for blaOXA-51-like gene. Antibiotic susceptibility of isolates was determined by standard disk diffusion method according to Clinical and Laboratory Standard Institute. The biofilm formation was studied using Congo red agar, test tube, and microtiter plate methods. The clinical isolates were 100% resistance to ciprofloxacin, ceftazidime, piperacillin, 96.15% to gentamicin, 96.15% to imipenem, 92.31% to meropenem, and 78.85% to amikacin. The soil A. baumannii isolates were 100% sensitive to imipenem, meropenem, and gentamicin, and 90.1% to ciprofloxacin. All A. baumannii isolates (clinical and soil) were susceptible to polymyxin B. The percentage of biofilm formation in Congo red agar, test tube, and microtiter plate assays was 10.81%, 63.51%, and 86.48%, respectively. More robust biofilm former population was mainly among non-MDR isolates. Isolates with a higher level of resistance tended to form weaker biofilms. The soil isolates exhibited less resistance to antibiotics than clinical isolates. However, the soil isolates produce stronger biofilms than clinical isolates.

scholarly journals Categorizing susceptibility of clinical isolates of Candida auris to amphotericin B, caspofungin, and fluconazole utilizing the CLSI M44-A2 disk diffusion method

2021 ◽  
Author(s):  
Natalie S. Nunnally ◽  
Tajah Damm ◽  
Shawn R. Lockhart ◽  
Elizabeth L. Berkow
Keyword(s):  
Amphotericin B ◽  
Accurate Method ◽  
Clinical Isolates ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Broth Microdilution ◽  
Candida Auris ◽  
Disk Diffusion Method ◽  
Microdilution Method ◽  
Broth Microdilution Method

We evaluated the CLSI M44ed3E disk diffusion method in comparison with the CLSI M27ed4 broth microdilution method for caspofungin and fluconazole and the Etest method for amphotericin B to categorize susceptibility of 347 clinical isolates of Candida auris. Utilizing the zone diameter cutoffs established here we observed the overall categorial agreement between the two methods. For caspofungin, concordant results were observed for 98% of isolates with <1% very major and 1% major errors. For fluconazole, concordant results were observed for 91% of isolates with 1% very major and 8% major errors. For amphotericin B, concordant results were observed for 74% of isolates with <1% very major errors and 25% major errors. The disk diffusion approach provides an accurate method for determining the susceptibility of C. auris for caspofungin and fluconazole, and for identification of at least 75% of amphotericin B-susceptible isolates.

scholarly journals Correlation between mazEF Toxin-Antitoxin System Expression and Methicillin Susceptibility in Staphylococcus aureus and Its Relation to Biofilm-Formation

2021 ◽  
Vol 9 (11) ◽  
pp. 2274
Author(s):  
Aya Abd El rahman ◽  
Yasmine El kholy ◽  
Rania Y. Shash
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Methicillin Resistance ◽  
Diffusion Method ◽  
P Value ◽  
Sequence Motifs ◽  
University Hospitals ◽  
Specific Sequence ◽  
Disk Diffusion Method ◽  
Cellular Mrnas

Methicillin resistance in Staphylococcus aureus has become prevalent globally. Moreover, biofilm-formation makes it more difficult to eradicate bacteria by antibiotics. The mazEF toxin-antitoxin system encodes for mazF, which acts as an endoribonuclease that cleaves cellular mRNAs at specific sequence motifs (ACA), and mazE, which opposes the mazF action. Our goal was to detect mazEF expression in methicillin-resistant S. aureus (MRSA) isolates compared with methicillin-sensitive S. aureus (MSSA) isolates and determine its relation to methicillin susceptibility as well as biofilm-formation. According to their susceptibility to cefoxitin disks, 100 S. aureus isolates obtained from patients admitted to Cairo University Hospitals were categorized into 50 MSSA and 50 MRSA according to their susceptibility to cefoxitin disks (30 µg). Antimicrobial susceptibility and biofilm-formation were investigated using the disk diffusion method and tissue culture plate method, respectively. Finally, using real-time PCR, mazEF expression was estimated and correlated to methicillin susceptibility and biofilm formation. Both MRSA and MSSA isolates showed the best sensitivity results with linezolid and gentamicin, where about 88% of MRSA isolates and 96% of MSSA isolates were sensitive to linezolid while 76% of MRSA isolates and 84% of MSSA isolates were sensitive to gentamicin. MRSA isolates were significantly more able to form biofilm than MSSA isolates (p-value = 0.037). The mazEF expression was significantly correlated to methicillin resistance in S. aureus (p-value < 0.001), but not to biofilm-formation.

Antimicrobial Effect of Quercus robur L. Leaves Selective Extracts from the Mezi Mountain of Djeniene Bourezg (West of Algeria)

2020 ◽  
Vol 16 (8) ◽  
pp. 1181-1190
Author(s):  
Elhassan Benyagoub ◽  
Nouria Nabbou ◽  
Amal Dine
Keyword(s):  
Clavulanic Acid ◽  
Quercus Robur ◽  
Biological Activities ◽  
Antifungal Susceptibility ◽  
Diffusion Method ◽  
Dilution Method ◽  
Medicinal Species ◽  
Disk Diffusion Method ◽  
Amoxicillin Clavulanic Acid ◽  
Microbial Strains

Background: Algeria, by its vast terrestrial extent and its climatic variation, has an abundant, rich and varied flora in which it was counted many aromatic and medicinal species that provide bioactive compounds characterized by their broad biological activities. In this context, this work is based on the evaluation of the antimicrobial activity of Quercus robur L. leaves extracts (Family of Fagaceae). Methods: Firstly, the collected plant material was defatted; then, the extraction of tannins and saponins was carried out according to a standard protocol where the extracts obtained were tested on some uropathogenic microbial strains by disk diffusion method with the determination of the Minimum Inhibitory Concentrations (MICs) by broth macro-dilution method. Results: The extraction yield of the selective extracts was 7.93 and 16.94% for tannins and saponins, respectively. The antibiotic resistance profile of the tested strains showed a resistance relatively important to several antibiotics, namely amoxicillin +clavulanic acid and ampicillin for Escherichia coli, while Pseudomonas aeruginosa showed resistance to amoxicillin+clavulanic acid, amikacin, cefotaxime and ceftazidime. However, Staphylococcus aureus was susceptible to penicillin, gentamicin, ofloxacin and chloramphenicol. Antifungal susceptibility testing has been shown that Candida albicans was susceptible to amphotericin B, econazole and it was clinically categorized as intermediate to miconazole drug. For antimicrobial tests, the tannins and saponins extracts exhibited a low to strong inhibitory effect at tested concentrations lower than 30 mg/mL (ranged from no inhibition to an inhibition zone diameter of 17.5 mm), depending on dose levels and tested microbial strains. Conclusion: This activity is proportional to the tested concentrations, knowing that tannins extract was more active compared to saponins extract. For this, Q. robur could constitute an important source for drug discovery.

scholarly journals Comparative analysis of disk diffusion and liquid medium microdillution methods for testing the antibiotic susceptibility patterns of anaerobic bacterial strains isolated from intra-abdominal infections

2011 ◽  
Vol 1 (6) ◽  
pp. 209-220 ◽  
Keyword(s):  
Antibiotic Susceptibility ◽  
Bacterial Resistance ◽  
Empiric Therapy ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Dilution Method ◽  
Bacterial Strains ◽  
Disk Diffusion Method ◽  
Broth Microdilution Method ◽  
Abdominal Infections

The antibiotic resistance aspects concerning the bacterial strains isolated from intra-abdominal infections signify at present a major problem of therapy. The empiric pre-operatory antimicrobial therapy plays a key role in the management and course of the intra-abdominal infections, an inappropriate therapy resulting in a poor outcome of the clinical cases and an increase of bacterial resistance. The purpose of the present paper was to compare the results of the antibiotic susceptibility of some selected anaerobic strains to certain antibiotics used in the empiric therapy of intra-abdominal infections, achieved by two different methods, in order to select for the current practice the most reliable, simple and rapid one. We have found a good correlation between the results obtained by the standard, Brucella broth microdilution method recommended by CLSI and the disk diffusion method (recommended by Bailey and Scott, 2002), for all tested antibiotics, demonstrating the possibility to use this last simplified method as an alternative to the laborious and time-consuming dilution method, for the routine testing of the antibiotic susceptibility of anaerobic stranis isolated in severe infections.

scholarly journals Biofilm formation, antimicrobial susceptibility and virulence genes of Uropathogenic Escherichia coli isolated from clinical isolates in Uganda

2020 ◽  
Author(s):  
Paul Katongole ◽  
Fatuma Nalubega ◽  
Najjuka Christine Florence ◽  
Benon Asiimwe ◽  
Irene Andia
Keyword(s):  
Antimicrobial Resistance ◽  
Antimicrobial Susceptibility ◽  
Biofilm Formation ◽  
Virulence Genes ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Cross Sectional ◽  
E Coli ◽  
Tract Infections

Abstract Introduction: Uropathogenic E. coli is the leading cause of Urinary tract infections (UTIs), contributing to 80-90% of all community-acquired and 30-50% of all hospital-acquired UTIs. Biofilm forming Uropathogenic E. coli are associated with persistent and chronic inflammation leading to complicated and or recurrent UTIs. Biofilms provide an environment for poor antibiotic penetration and horizontal transfer of virulence genes which favors the development of Multidrug-resistant organisms (MDRO). Understanding biofilm formation and antimicrobial resistance determinants of Uropathogenic E. coli strains will provide insight into the development of treatment options for biofilm-associated UTIs. The aim of this study was to determine the biofilm forming capability, presence of virulence genes and antimicrobial susceptibility pattern of Uropathogenic E. coli isolates in Uganda. Methods: This was a cross-sectional study carried in the Clinical Microbiology and Molecular biology laboratories at the Department of Medical Microbiology, Makerere University College of Health Sciences. We randomly selected 200 Uropathogenic E. coli clinical isolates among the stored isolates collected between January 2018 and December 2018 that had significant bacteriuria (>105 CFU). All isolates were subjected to biofilm detection using the Congo Red Agar method and Antimicrobial susceptibility testing was performed using the Kirby disk diffusion method. The isolates were later subjected PCR for the detection of Urovirulence genes namely; Pap, Fim, Sfa, Afa, Hly and Cnf, using commercially designed primers.Results: In this study, 62.5% (125/200) were positive biofilm formers and 78% (156/200) of these were multi-drug resistant (MDR). The isolates were most resistant to Trimethoprim sulphamethoxazole and Amoxicillin (93%) followed by gentamycin (87%) and the least was imipenem (0.5%). Fim was the most prevalent Urovirulence gene (53.5%) followed by Pap (21%), Sfa (13%), Afa (8%), Cnf (5.5%) and Hyl (0%).Conclusions: We demonstrate a high prevalence of biofilm-forming Uropathogenic E. coli strains that are highly associated with the MDR phenotype. We recommend routine surveillance of antimicrobial resistance and biofilm formation to understand the antibiotics suitable in the management of biofilm-associated UTIs.

scholarly journals Biofilm formation, antimicrobial susceptibility and virulence genes of Uropathogenic Escherichia coli isolated from clinical isolates in Uganda

2019 ◽  
Author(s):  
Paul Katongole ◽  
Fatuma Nalubega ◽  
Najjuka Christine Florence ◽  
Benon Asiimwe ◽  
Irene Andia
Keyword(s):  
Antimicrobial Resistance ◽  
Antimicrobial Susceptibility ◽  
Biofilm Formation ◽  
Virulence Genes ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Cross Sectional ◽  
E Coli ◽  
Tract Infections

Abstract Introduction: Uropathogenic E. coli is the leading cause of Urinary tract infections (UTIs), contributing to 80-90% of all community-acquired and 30-50% of all hospital-acquired UTIs. Biofilm forming Uropathogenic E. coli are associated with persistent and chronic inflammation leading to complicated and or recurrent UTIs. Biofilms provide an environment for poor antibiotic penetration and horizontal transfer of virulence genes which favors the development of Multidrug-resistant organisms (MDRO). Understanding biofilm formation and antimicrobial resistance determinants of Uropathogenic E. coli strains will provide insight into the development of treatment options for biofilm-associated UTIs. The aim of this study was to determine the prevalence of biofilm formation among Uropathogenic E. coli clinical isolates, their relationship with antimicrobial susceptibility patterns, and Urovirulence genes. Methods: This was a cross-sectional study carried in the Clinical Microbiology and Molecular biology laboratories at the Department of Medical Microbiology, Makerere University College of Health Sciences. We randomly selected 200 Uropathogenic E. coli clinical isolates among the stored isolates collected between January 2018 and December 2018 that had significant bacteriuria (>105 CFU). All isolates were subjected to biofilm detection using the Congo Red Agar method and Antimicrobial susceptibility testing was performed using the Kirby disk diffusion method. The isolates were later subjected PCR for the detection of Urovirulence genes namely; Pap, Fim, Sfa, Afa, Hly and Cnf, using commercially designed primers.Results: In this study, 62.5% (125/200) were positive biofilm formers and 78% (156/200) of these were multi-drug resistant(MDR). The isolates were most resistant to Trimethoprim sulphamethoxazole and Amoxicillin (93%) followed by gentamycin (87%) and the least was imipenem (0.5%). Fim was the most prevalent Urovirulence gene (53.5%) followed by Pap (21%), Sfa (13%), Afa (8%), Cnf (5.5%) and Hyl (0%).Conclusions: We demonstrate a high prevalence of biofilm-forming Uropathogenic E. coli strains that are highly associated with the MDR phenotype. We recommend routine surveillance of antimicrobial resistance and biofilm formation to understand the antibiotics suitable in the management of biofilm-associated UTIs.

scholarly journals Antibiotic Resistance Profiling and Molecular Phylogeny of Biofilm Forming Bacteria From Clinical and Non-clinical Environment in Southern Part of Bangladesh

2019 ◽  
Vol 7 (2) ◽  
pp. 37-43 ◽  
Author(s):  
Zulkar Nain ◽  
Md. Ariful Islam ◽  
Mohammad Minnatul Karim
Keyword(s):  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Rrna Gene ◽  
Bacterial Isolates ◽  
Clinical Environment ◽  
Biochemical Tests ◽  
Disk Diffusion Method ◽  
Phylogenetic Characterization

Background: Biofilm is a surface adhered extracellular polymer matrix produced by bacteria. The establishment of biofilms is considered as an important pathogenic trait in many chronic infections and antibiotic resistance. Objective: The present study was intended to evaluate biofilm forming potency and antibiotic resistance (AR) pattern in clinical and non-clinical bacterial isolates, and their phylogenetic characterization. Materials and Methods: A total of 82 bacterial isolates were obtained from clinical settings and animal farms from southern (Kushtia-Jhenaidah) region of Bangladesh. Biofilm forming potentials and AR profile were evaluated by standard biofilm assay and Kirby-Bauer disk diffusion method, respectively. Further, antibiotic exposure was assessed by multiple antibiotic resistance (MAR) value indexing. Furthermore, statistical methods were applied to estimate the relationship between AR and biofilm formation. Finally, selected isolates were characterized by morphological and biochemical tests, as well as 16S rRNA gene sequencing. Results: Clinical isolates showed higher biofilm formation (OD595=1.17±0.03) than non-clinical isolates (OD595=0.68±0.03). Among all, Pseudomonas isolates produced the highest amount of biofilms (OD595=2.08±0.02). The AR profiles fell within 46.67-86.67% and MAR index ranged from 0.47 to 0.87. Moreover, a significant positive correlation (P<0.05) was found between biofilm formation and AR. Eventually, heavy biofilm producers with ≥60% resistance profile were characterized and identified as Escherichia coli, Cronobacter sakazakii, Pseudomonas aeruginosa, Staphylococcus sciuri, and Staphylococcus aureus. Conclusion: In general, biofilm formation and MAR were highly correlated regardless of the source, type, and environment of the isolates. Therefore, a rigorous evaluation of both biofilm formation and AR is demanded to minimize AR and associated problems.

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