scholarly journals Comparative analysis of novel suspension testing and agar cup diffusion methods in establishing the susceptibility of Pseudomonas aeruginosa against ethanol and chlorhexidine gluconate

2020 ◽  
Vol 11 (SPL2) ◽  
pp. 271-275
Author(s):  
Hemalatha E ◽  
Bhuvaneshwari G ◽  
Kalyani M
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Comparative Analysis ◽  
Susceptibility Testing ◽  
Chlorhexidine Gluconate ◽  
Diffusion Method ◽  
Time Consumption ◽  
Testing Method ◽  
Resistant Strains ◽  
Sensitive Method

Pseudomonas aeruginosa is one among the leading nosocomial pathogens worldwide. It is therefore necessary to decrease and to prevent a rebound of growth. Comparison of novel suspension testing method and agar cup diffusion method results in determination of the sensitive method to identify effectiveness of disinfectants against microbial activity. This study was carried out to determine the effectiveness among novel suspension testing and agar cup diffusion method to determine disinfectant susceptibility and also to identify the efficacy of ethanol and chlorhexidine gluconate at manufacturer’s concentration against Pseudomonas aeruginosa. In this study 50 isolates of Pseudomonas aeruginosa were included. Each isolate was subjected to novel suspension testing method and agar cup diffusion method with ethanol and chlorhexidine gluconate, the results were observed and recorded. The 50 isolates, sensitive strains showed 100% sensitivity to chlorhexidine gluconate and 95% to ethanol. Whereas resistant strains showed 100% sensitivity to chlorhexidine gluconate, 75% were sensitive to ethanol. Both agar cup diffusion method and novel suspension method yielded similar results. With the advantage of easy processing and less time consumption, agar cup diffusion method can be routinely used for determining the disinfectant susceptibility testing.

scholarly journals Pseudomonas aeruginosa serotypes and resistance to antibiotics from wound swabs

2015 ◽  
Vol 72 (11) ◽  
pp. 996-1003 ◽  
Author(s):  
Natasa Stankovic-Nedeljkovic ◽  
Branislav Tiodorovic ◽  
Branislava Kocic ◽  
Vojislav Ciric ◽  
Marko Milojkovic ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Susceptibility Testing ◽  
Wound Infections ◽  
Common Cause ◽  
Resistance To Antibiotics ◽  
Mucous Membranes ◽  
Common Serotypes ◽  
Antibiotics Susceptibility

Introduction/Aim. Pseudomonas aeruginosa (P. aeruginosa) is the most common cause of wound infections, following the disruption of the skin or mucous membranes integrity. The aim of this study was to analyze of the presence P. aeruginosa in wound swabs, antibiotics susceptibility testing, determination of the minimum inhibitory concentrations (MICs) of antibiotics, testing of the metallo-?-lactamases (MBLs) production, isolates serotyping and analysis of the most common serotypes resistance. Methods. A total of 90 outpatients and 55 intpatients wound swabs were cultivated. Wound swabs were taken from the patients with wound infections symptoms. Antibiotics susceptibility testing was performed to: meropenem, imipenem, piperacillin-tazobactam, ceftazidime, cefepime, amikacin, gentamicin, netilmicin, ofloxacin, ciprofloxacin and colistin (HiMedia). Polyvalent and monovalent antisera for agglutination (Biorad) were used in P. aeruginosa agglutination. Results. P. aeruginosa was isolated from 36.55% wound swabs (36.66% of the inpatients wounds and 36.36% of the outpatients). The analyzed isolates showed the highest degree of sensitivity to colistin (100%) and meropenem (93.44%) and the lowest to cefepime (19.54%). The majority of the inpatients isolates had 12 ?g/mL (28.57%) MIC for piperacillin-tazobactam and 16 ?g/mL (28.57%) for the outpatients. The most common MICs for ciprofloxacin were 0.19 ?g/mL (31.81%) for the nosocomial isolates, and 0.25 ?g/mL (28.57%) for the outpatients? ones. The most common MICs for amikacin of the nosocomial isolates were 6 ?g/ml (40.9%), and for the outpatients ones 4 ?g/mL (33.33%). Five (9.43%) isolates produced MBLs. The most common serotypes were P11 (22.64%), P6 (15.09%) and P1 (11.32%). Conclusion. Neither the increased presence of P. aeruginosa was noticed in wounds swabs, nor the antibiotic resistance in the nosocomial isolates compared to those from outpatients. The analyzed isolates had the higest sensitivity to colistin and meropenem, and the lowest to cefepime.

scholarly journals Phytochemical Study and Antibacterial and Antibiotic Modulation Activity of Punica granatum (Pomegranate) Leaves

Scientifica ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Amine Trabelsi ◽  
Mohamed Amine El Kaibi ◽  
Aïmen Abbassi ◽  
Amira Horchani ◽  
Leila Chekir-Ghedira ◽  
...  
Keyword(s):  
Antibacterial Properties ◽  
Punica Granatum ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Leaf Extracts ◽  
Phytochemical Study ◽  
E Coli ◽  
Microdilution Method ◽  
Resistant Strains

This study aimed to determine phytochemical contents, antibacterial properties, and antibiotic modulating potential of Punica granatum leaf extracts: hexane, chloroform, ethyl acetate, ethanol, and aqueous extracts as well as an extract enriched with total oligomer flavonoids (TOFs). The TOF extract contained the highest value of phenols and flavonoids. Rutin, luteolin, gallic acid, and ellagic acid were determined by HPLC analysis of this extract. The antibacterial activity was assayed by the disc diffusion method and microdilution method against Staphylococcus aureus and Escherichia coli standard ATCC strains and clinical isolates resistant strains. The TOF extract was the most active against all tested strains. The checkerboard method was used for the determination of synergy between two antibiotics (amoxicillin and cefotaxime) and P. granatum leaf extracts. The best synergistic interaction was found with TOF extract combined with amoxicillin for penicillin-resistant E. coli and penicillin-resistant S. aureus. These results can be assigned to tannins, flavonoids, and phenolic acids found in P. granatum leaf extracts. Pomegranate leaf extracts or active compounds isolated from these extracts could be used to fight the emergence and spread of resistant bacterial strains.

scholarly journals Multicenter Evaluation of the Etest Gradient Diffusion Method for Ceftolozane-Tazobactam Susceptibility Testing of Enterobacteriaceae and Pseudomonas aeruginosa

2018 ◽  
Vol 56 (9) ◽  
Author(s):  
Adam L. Bailey ◽  
Tom Armstrong ◽  
Hari-Prakash Dwivedi ◽  
Gerald A. Denys ◽  
Janet Hindler ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Susceptibility Testing ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Beta Lactam ◽  
Content Type ◽  
Gradient Diffusion ◽  
Tract Infections ◽  
Abdominal Infections ◽  
Inhibitor Combination

ABSTRACT Ceftolozane-tazobactam (C/T) is a novel beta-lactam–beta-lactamase inhibitor combination antibiotic approved by the U.S. Food and Drug Administration in 2014 for the treatment of complicated intra-abdominal infections (in combination with metronidazole) and complicated urinary tract infections. In this study, we evaluated the performance of the C/T Etest, a gradient diffusion method. C/T Etest was compared to broth microdilution (BMD) for 51 Enterobacteriaceae challenge isolates and 39 Pseudomonas aeruginosa challenge isolates at three clinical sites. Essential agreement (EA) between the methods ranged from 47 to 49/51 (92.2 to 96.1%) for the Enterobacteriaceae, and categorical agreement (CA) ranged from 49 to 51/51 (96.1 to 100.0%). EA and CA for P. aeruginosa were 100% at all sites. The C/T Etest was also compared to BMD for susceptibility testing on 966 clinical isolates (793 Enterobacteriaceae, including 167 Klebsiella pneumoniae and 159 Escherichia coli isolates, in addition to 173 P. aeruginosa isolates) collected at four clinical sites. EA between Etest and BMD was 96.9% for Enterobacteriaceae isolates and 98.8% for P. aeruginosa isolates. Within the Enterobacteriaceae, isolates from each species examined had >96% CA. For the clinical isolates, no very major errors were identified but two major errors were found (one for K. pneumoniae and one for Providencia rettgeri). By BMD, 47.0% of Enterobacteriaceae and 46.2% of P. aeruginosa challenge strains were nonsusceptible to C/T by CLSI breakpoint criteria; 8.2% of clinical Enterobacteriaceae isolates and 12.1% of clinical P. aeruginosa isolates were nonsusceptible to C/T by CLSI breakpoint criteria. In conclusion, Etest is accurate and reproducible for C/T susceptibility testing of Enterobacteriaceae and P. aeruginosa.

scholarly journals In VitroActivity of Fosfomycin against a Collection of Clinical Pseudomonas aeruginosa Isolates from 16 Spanish Hospitals: Establishing the Validity of Standard Broth Microdilution as Susceptibility Testing Method

2013 ◽  
Vol 57 (11) ◽  
pp. 5701-5703 ◽  
Author(s):  
María Díez-Aguilar ◽  
María-Isabel Morosini ◽  
Rosa del Campo ◽  
María García-Castillo ◽  
Javier Zamora ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Susceptibility Testing ◽  
Disk Diffusion ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Broth Microdilution ◽  
Content Type ◽  
Testing Method ◽  
Broth Microdilution Method ◽  
Agar Dilution

ABSTRACTThe broth microdilution method for fosfomycin andPseudomonas aeruginosawas assessed and compared with the approved agar dilution method in 206 genetically unrelatedP. aeruginosaclinical isolates. Essential agreement between the two methods was 84%, and categorical agreement was 89.3%. Additionally, Etest and disk diffusion assays were performed. Results validate broth microdilution as a reliable susceptibility testing method for fosfomycin againstP. aeruginosa. Conversely, unacceptable concordance was established between Etest and disk diffusion results with agar dilution results.

scholarly journals Molecular Analysis of Pathogenic Genes (lasB and exoA) in Pseudomonas aeruginosa Strains Isolated from Animal and Human Samples and Determination of Their Resistance Pattern

2021 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Ciamak Ghazaei
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Bacterial Pathogenicity ◽  
Human Samples ◽  
Pathogenic Genes ◽  
Serious Infection ◽  
Wide Range ◽  
Significant Difference

: Pseudomonas aeruginosa (P. aeruginosa) has a wide range of virulence factors. These factors have the potential to increase bacterial pathogenicity and serious infection. The purpose of this study was to evaluate the virulence profiles and antibiotic susceptibility of isolates of P. aeruginosa originated from animal and human samples. The samples were cultured on selective media before being extracted for DNA and subjected to a PCR technique to detect virulence genes. There was a significant difference in the isolation of P. areuginosa isolated from human and animal sources. Where, in humans, the percentage of P. areuginosa was 52 (68.42%) while in animals the percentage of P.aeruginosa was 24 (31.57%). In humans, the percentage of P. aeruginosa in blood was 26.92% (14 isolates), in urine it was 25% (13 isolates), in wound it was 40.38%21 isolates), and in sputum it was 7.69% (4 isolates). We used a PCR technique that produced highly specific and accurate results for detecting virulence factor genes in P. aeruginosa isolates that cause disease in humans and animals. The percentage of exoA genes was (83.33%) and (81.66%) in the animal and human, and that of lasB was (58.33%) and (92.30%) in animal and human samples respectively. Furthermore, both the exoA and lasB genes are found in 26.31% of animal strains and 17.10% of human strains. The disc diffusion method was used to determine antimicrobial susceptibility. In both animal and human isolates, P. aeruginosa showed the highest resistance to amikacin and the lowest resistance to ciprofloxacin. These findings could aid in the understanding of pathogenicity processes, treatment direction, and the development of strategies to control the spread of epidemic P. aeruginosa strains.

scholarly journals Comparison of Agar Diffusion Methodologies for Antimicrobial Susceptibility Testing of Pseudomonas aeruginosa Isolates from Cystic Fibrosis Patients

2000 ◽  
Vol 38 (5) ◽  
pp. 1818-1822 ◽  
Author(s):  
Jane L. Burns ◽  
Lisa Saiman ◽  
Susan Whittier ◽  
Davise Larone ◽  
Jay Krzewinski ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Susceptibility Testing ◽  
Correlation Coefficients ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Broth Microdilution ◽  
Disk Diffusion Method ◽  
Agar Diffusion ◽  
Broth Microdilution Method

Pseudomonas aeruginosa is the most common pathogen infecting the lungs of patients with cystic fibrosis (CF). Improved antimicrobial chemotherapy has significantly increased the life expectancy of these patients. However, accurate susceptibility testing of P. aeruginosa isolates from CF sputum may be difficult because the organisms are often mucoid and slow growing. This study of 597 CF isolates of P. aeruginosa examined the correlation of disk diffusion and Etest (AB BIODISK, Solna, Sweden) results with a reference broth microdilution method. The rates of interpretive errors for 12 commonly used antipseudomonal antimicrobials were determined. The disk diffusion method correlated well (zone diameter versus MIC) for all of the agents tested. However, for mucoid isolates, correlation coefficients (r values) for piperacillin, piperacillin-tazobactam, and meropenem were <0.80. The Etest correlation with reference broth microdilution results (MIC versus MIC) was acceptable for all of the agents tested, for both mucoid and nonmucoid isolates. Category interpretation errors were similar for the disk diffusion and Etest methods with 0.4 and 0.1%, respectively, very major errors (false susceptibility) and 1.1 and 2.2% major errors (false resistance). Overall, both agar diffusion methods appear to be broadly acceptable for routine clinical use in susceptibility testing of CF isolates of P. aeruginosa.

scholarly journals Implementing EUCAST rapid antimicrobial susceptibility testing method for sepsis: lessons learned in a tertiary care center

2021 ◽  
Vol 15 (06) ◽  
pp. 833-839
Author(s):  
Mohammad Aadam Bin Najeeb ◽  
Ayush Gupta ◽  
Shashank Purwar ◽  
Vishnu Teja Nallapati ◽  
Jogender Yadav ◽  
...  
Keyword(s):  
Blood Culture ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Error Rates ◽  
Antimicrobial Susceptibility Testing ◽  
Diffusion Method ◽  
Major Error ◽  
Disk Diffusion Method ◽  
Testing Method ◽  
Micro Organisms

Introduction: We prospectively evaluated EUCAST rapid antimicrobial susceptibility testing methodology for susceptibility testing directly from blood culture bottles in comparison to CLSI disk-diffusion method. Methodology: During May-November 2019, positively flagged blood culture bottles showing Gram-negative micro-organisms were simultaneously processed by rapid antimicrobial susceptibility testing and CLSI methodology. Antibiotics tested were cefotaxime, ceftazidime, piperacillin-tazobactam, imipenem, meropenem, gentamicin, tobramycin and trimethoprim-sulphamethoxazole. Results: Overall, 80 isolates identified as Escherichia coli (n = 24, 30%), Klebsiella pneumoniae (n = 15, 18.7%), Pseudomonas aeruginosa (n = 16, 20%) and Acinetobacter baumannii (n = 25, 31.2%) were included. Categorical agreements  of rapid antimicrobial susceptibility testing at 4-, 6- and 8-hour reading times were 88.1% (304/345), 90.8% (425/468) and 92.3% (467/506), respectively. Major Error rates were 14% (21/150), 4.9% (10/206) and 4/236 (1.7%), whereas Very Major Error rates were 1.1% (2/177), 1.3% (3/232) and 3.3% (8/243), respectively. Results categorized as “Area of Technical Uncertainty” were significantly lower at 8-hour {10.2% (39/384) vs 5.2% (28/534), 4- vs 8-hour, p = 0.003, Fischer’s exact test}. Conclusions: Except for a slightly higher Very major error rate, rapid antimicrobial susceptibility testing at 8-hour is equivalent to Disk-diffusion method (CLSI-M100) using CLSI-M52 criteria for equivalence: (Categorical agreement ≥ 90%, Very major error ≤ 1.5% and Major error ≤ 3%). Poor Categorical agreements at all reading times were noted for piperacillin-tazobactam, ciprofloxacin and E. coli. Performance of rapid antimicrobial susceptibility testing methodology in resource limited settings brings unique challenge of identifying micro-organisms within 8 hours. We suggest reading and reporting of results at a single time point using rapid antimicrobial susceptibility testing method i.e. at 8-hour.

scholarly journals Performance Evaluation of the Gradient Diffusion Strip Method and Disk Diffusion Method for Ceftazidime–Avibactam Against Enterobacterales and Pseudomonas aeruginosa: A Dual-Center Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Jingjia Zhang ◽  
Gang Li ◽  
Ge Zhang ◽  
Wei Kang ◽  
Simeng Duan ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Carbapenem Resistance ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Major Error ◽  
Beta Lactam ◽  
Disk Diffusion Method ◽  
Strip Method ◽  
Gradient Diffusion

Objectives: Ceftazidime–avibactam is a novel synthetic beta-lactam + beta-lactamase inhibitor combination. We evaluated the performance of the gradient diffusion strip method and the disk diffusion method for the determination of ceftazidime–avibactam against Enterobacterales and Pseudomonas aeruginosa.Methods: Antimicrobial susceptibility testing of 302 clinical Enterobacterales and Pseudomonas aeruginosa isolates from two centers were conducted by broth microdilution (BMD), gradient diffusion strip method, and disk diffusion method for ceftazidime–avibactam. Using BMD as a gold standard, essential agreement (EA), categorical agreement (CA), major error (ME), and very major error (VME) were determined according to CLSI guidelines. CA and EA rate &gt; 90%, ME rate &lt; 3%, and VME rate &lt; 1.5% were considered as acceptable criteria. Polymerase chain reaction and Sanger sequencing were performed to determine the carbapenem resistance genes of all 302 isolates.Results: A total of 302 strains were enrolled, among which 182 strains were from center 1 and 120 strains were from center 2. A percentage of 18.21% (55/302) of the enrolled isolates were resistant to ceftazidime–avibactam. The CA rates of the gradient diffusion strip method for Enterobacterales and P. aeruginosa were 100% and 98.65% (73/74), respectively, and the EA rates were 97.37% (222/228) and 98.65% (73/74), respectively. The CA rates of the disk diffusion method for Enterobacterales and P. aeruginosa were 100% and 95.95% (71/74), respectively. No VMEs were found by using the gradient diffusion strip method, while the ME rate was 0.40% (1/247). No MEs were found by using the disk diffusion method, but the VME rate was 5.45% (3/55). Therefore, all the parameters of the gradient diffusion strip method were in line with acceptable criteria. For 31 blaKPC, 33 blaNDM, 7 blaIMP, and 2 blaVIM positive isolates, both CA and EA rates were 100%; no MEs or VMEs were detected by either method. For 15 carbapenemase-non-producing resistant isolates, the CA and EA rates of the gradient diffusion strips method were 100%. Whereas the CA rate of the disk diffusion method was 80.00% (12/15), the VME rate was 20.00% (3/15).Conclusion: The gradient diffusion strip method can meet the needs of clinical microbiological laboratories for testing the susceptibility of ceftazidime–avibactam drugs. However, the VME rate &gt; 1.5% (5.45%) by the disk diffusion method. By comparison, the performance of the gradient diffusion strip method was better than that of the disk diffusion method.

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