scholarly journals Comparison of two disk diffusion and E-test methods in determining antibiotic susceptibility of Pseudomonas aeruginosa strains in isolated burn infections of Ahvaz City

2020 ◽  
Vol 19 (4) ◽  
pp. 646-651
Author(s):  
Changiz Ahmadizadeh ◽  
Mehrdad Pashazadeh

Background: Pseudomonas aeruginosa with widely distributed in nature, for human beings is considered an opportunistic pathogen that causes infections of broad-spectrum, including administrative, respiratory, septicemia and bacteremia and sepsis in patients with the burning city of Ahvaz. Method and Material: A total of 95isolates of Pseudomonas aeruginosa isolated from burn patients from January 2015 assemble and biochemical identification test, then they are antibiotic resistance in E. test and disk diffusion method were compared. Findings: From 95 different clinical isolates of Pseudomonas aeruginosa isolated from E. test with the highest sensitivity to the antibiotic ceftazidime , 70(68/73%) and ciprofloxacin 50 (63/52%) and gentamicin 48 (52 /50 %) and the antibiotic imipenem 44 (31/46%) were sensitive and disk diffusion method antibiotic ceftazidime, 67(52/70%) and the antibiotic Ciprofloxacin 51(68/53%) and safety antibiotic imipenem 49(57/51%) and gentamicin 48(52/50%) were sensitive. Conclusion: Statistically significant differences between E. test and disk diffusion antimicrobial susceptibility of there (p<0.05) and disk diffusion method can replace E. test, and also the most sensitive antibiotics, the antibiotics used The study of the isolated Pseudomonas is ceftazidime. Bangladesh Journal of Medical Science Vol.19(4) 2020 p.646-651

Author(s):  
Jenies Grullon ◽  
James P. Mack ◽  
Albert Rojtman

<div class="WordSection1"><p><strong>Objective: </strong>The development of antibiotics was a revolutionary scientific discovery and medical advancement that greatly extended the life expectancy of mankind. Through less than 100 y of using antibiotics to treat infectious bacteria, some of these highly adaptive organisms have developed resistance to the drugs. The healthcare field is greatly concerned with the threat of many common infections that have been considered treatable for decades, regaining its ability to be severely fatal; thus, making alternative treatments currently in high demand. This study concentrated on investigating an alternative treatment for a specific gram-negative bacterium, <em>Pseudomonas aeruginosa (P. aeruginosa)</em>, a resistance-gaining bacteria that commonly infects hospitalized patients with weakened immune systems and/or open wounds.</p><p><strong>Methods: </strong>Prior to the age of modern medicine, human beings relied on nature for medicinal treatments. In our research, we focused on determining the <em>in vitro </em>efficacy of using the essential oils, cassia and cinnamon bark, their major component, cinnamaldehyde, as well as the major component of manuka honey, methylglyoxal, as an alternative treatment against <em>P. aeruginosa</em> We tested cassia, cinnamon bark, cinnamaldehyde, and methylglyoxal using the Kirby-Bauer disk diffusion method; the diameter of the zone of inhibition for each treated bacterial sample was measured and compared with the standard antibiotic treatments, tobramycin, and amikacin.</p><p><strong>Results: </strong>This study showed that the selected essential oils, cinnamaldehyde, and methylglyoxal were as effective or better in inhibiting the growth of <em>P. aeruginosa </em>compared to the standard aminoglycoside antibiotics.</p><p><strong>Conclusion: </strong>The tested essential oils, cinnamaldehyde, and methylglyoxal may be useful as an alternative treatment for infections caused by <em>P. aeruginosa</em> and may also provide communities where antibiotics are not readily available, a cost-effective way to treat this infectious disease.</p></div>


2021 ◽  
pp. 75-82
Author(s):  
اخلاص نعمة

Pseudomonas aeruginosa is an opportunistic pathogen that causes a number of infections in immunocompromised patients. This organism appears to improve resistance  to many antimicrobial agents and a high percentage of clinical isolates of P. aeruginosa exhibit multidrug resistance (MDR) phenotype . The purpose of this study is to screen the antibiotic susceptibility patterns and the prevalence of qacE delta1 gene among bacterial isolates. Accordingly, 145 samples were collected from different clinical sources from patients who admitted to different hospitals in Baghdad city in a period ranged 23/8/2018-1/1/2019. The isolates were diagnosed as P. aeruginosa based on routine bacteriological methods and confirmed by a molecular method using 16SrRNA gene. The antibiotic  susceptibility test was performed to all identified isolates by Kirby-Bauer Disk Diffusion method using ten  types of antibiotics. The results of antibiotics susceptibility test revealed high levels of resistance toward Piperacillin (72.22%), Trimethoprim (68%), Ceftazidime (68%), Colistin (40.28%), and Levofloxacin (33.33%). And , the minimum inhibitory concentration (MIC) of Cetrimide was tested using different concentrations (2.048 to 0.004µg/100µl) and the results showed that MIC values ranged between 2.048 and 0.016) μg/100μL, and  the concentration of  0.256 μg/100μl was more frequent . Finally, the prevalence of qacE delta1 gene among bacterial isolates was detected in percentage  63.88% among bacterial isolates .


2020 ◽  
Vol 20 (5) ◽  
pp. 758-762
Author(s):  
Omid Zarei ◽  
Hassan Mahmoudi ◽  
Ali Mohammadi Bardbari ◽  
Pezhman Karami ◽  
Mohammad Yousef Alikhani

Background: Pseudomonas aeruginosa is a gram-negative non-glucose fermenting aerobic bacteria and an opportunistic pathogen in humans and animals. The present study was carried out to investigate the distribution of virulence factors and antibiotic resistance properties of P. aeruginosa isolated from patients and intensive care unit (ICU) environment. Material and Methods: A total of 116 P. aeruginosa isolated from patients and ICU environment were collected from Besat hospital in Hamadan, the West of Iran. P. aeruginosa isolates were analyzed based on the presence of the virulence factors encoding genes included exoA, exoS, exoU, and algD using polymerase chain reaction (PCR). Antimicrobial susceptibility test was performed using a disk diffusion method. Results: The results showed the prevalence of exoA 33 (56.9%), exoS 21 (36.20%), exoU 37 (63.8%), and algD 35 (60.34%) genes in ICU environment P. aeruginosa strains and exo A 23 (39.25%), exoS 25 (43.1%), exoU 40(68.98%), and algD 25 (43.1%) genes in clinical isolates of P. aeruginosa. High resistance levels of the clinical and ICU environment isolate to ampicillinsulbactam (100%), were also observed. Conclusions: Our findings should raise awareness about antibiotic resistance in hospitalized patients in Iran. Clinicians should exercise caution in prescribing antibiotics, especially in cases of human infections.


2013 ◽  
Vol 13 (1) ◽  
pp. 45-48
Author(s):  
Shamweel Ahmed ◽  
Mohmammed Nawaf Al-Harbi

Pseudomonas aeruginosa is one of the most common gram-negative bacteria. identified in the clinical specimens of hospital admitted patients. A major problem in P. aeruginosa infection may be that this pathogen exhibits a high degree of resistance to a broad spectrum of antibiotics. The study aimed to isolate and determine the antimicrobial susceptibility patterns of the P. aeruginosa. This prospective study was done over a period of six months. Forty one clinical isolates of Pseudomonas aeruginosa (P. aeruginosa) were isolated from sputum specimens of the patients suspected of having respiratory tract infection. The antibiotic susceptibility profiles of all the isolates were determined using disk diffusion method as recommended by Clinical Laboratory Standards Institute. Ciprofloxacin was found to be the most effective antimicrobial agent with 85.4% susceptibility followed by imipenem (75.6%), aminoglycosides (amikacin, 95.1% and gentamicin, 90.3%), and the beta-lactams (cefepime 65.8%, ceftazidime, 51.2%). Piperacillin showed the maximum resistance (46.3%) followed by Aztreonam (36.6%). Regular antimicrobial susceptibility surveillance is essential for area-wise monitoring of the resistance patterns. An effective national and state level antibiotic policy and draft guidelines should be introduced to preserve the effectiveness of antibiotics and for better patient management. DOI: http://dx.doi.org/10.3329/bjms.v13i1.17428 Bangladesh Journal of Medical Science Vol. 13 No. 01 January2014: 45-48. Table I & Figure I added on 02 February 2014.


2000 ◽  
Vol 38 (5) ◽  
pp. 1818-1822 ◽  
Author(s):  
Jane L. Burns ◽  
Lisa Saiman ◽  
Susan Whittier ◽  
Davise Larone ◽  
Jay Krzewinski ◽  
...  

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.


2020 ◽  
Author(s):  
Qi Wang ◽  
Feifei Zhang ◽  
Zhanwei Wang ◽  
Hongbin Chen ◽  
Xiaojuan Wang ◽  
...  

Abstract Background: Gram-negative bacilli, particularly Enterobacterales and Pseudomonas aeruginosa, often acquire antimicrobial resistance. Ceftazidime-avibactam was approved for use in China in 2019. However, currently available commercial antimicrobial susceptibility test kits have not yet been developed. Here, we evaluated the Etest and disk diffusion method for assessment of the efficacy of ceftazidime-avibactam against Enterobacterales and P. aeruginosa in China. Results: In total, 194 Enterobacterales and 77 P. aeruginosa isolates, which were divided into a random selection group (140 Enterobacterales and 54 P. aeruginosa isolates) and a stock group (46 Enterobacterales and 31 P. aeruginosa isolates), were assessed by the Etest, disk diffusion, and broth microdilution (BMD) methods. Minimum inhibitory concentrations (MICs) and zone diameters were interpreted according to the CLSI M100 30th edition. For all 271 Enterobacterales and P. aeruginosa isolates, no very major errors were found using Etests. The overall categorical agreement rates (CA%) of Etests for Enterobacterales and P. aeruginosa were 99.5% (193/194) and 96.1% (74/77), respectively. The overall essential agreement rates (EA%) of Etests for Enterobacterales and P. aeruginosa were 95.9% (186/194) and 94.8% (73/77), respectively. In both the random selection and stock groups, EA% and CA% values of Etests exceeded 90%. Overall CA% values of the disk diffusion method for Enterobacterales and P. aeruginosa were 98.5% (191/194) and 93.5% (71/77), respectively. There was no linear relationship between zone diameter and BMD MIC. Conclusions: For Enterobacterales and P. aeruginosa, Etests and the disk diffusion method could have better performance as alternative methods to meet the needs of clinical treatment interpretation. Application of the disk diffusion method in Enterobacterales was superior to that in P. aeruginosa.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jingjia Zhang ◽  
Gang Li ◽  
Ge Zhang ◽  
Wei Kang ◽  
Simeng Duan ◽  
...  

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.


2014 ◽  
Vol 63 (1) ◽  
pp. 18-23
Author(s):  
Hiromi MORISHIGE ◽  
Yoshihito OTSUKA ◽  
Akihiro TOGUCHI ◽  
Masako HIRATA ◽  
Kohei HASHIMOTO ◽  
...  

2020 ◽  
Author(s):  
Masoumeh Kiani ◽  
Akram Astani ◽  
Hamed Afkhami ◽  
Mansoor Khaledi ◽  
Javad Fathi ◽  
...  

Abstract Background: The current study was aimed to investigate the prevalence of the mutations of the oprD gene among imipenem-resistant and -sensitive Pseudomonas aeruginosa isolated from educational hospitals in Yazd, Iran.Methods: In this study, 90 P. aeruginosa isolates were collected from different clinical samples and transferred to the Department of Microbiology, Shahid Sadoghi University of Medical Science, during 2015 to 2016. All isolates were identified by the conventional biochemical tests and antibiotic resistance was determined using disk diffusion method. E. test was performed to determine the minimum inhibitory concentrations (MIC) of imipenem. The mutations of upstream of the oprD coding region and its promoters and 54 primary nucleotide of this gene were recognized by the amplification of this region and subsequently sequenced.Results: Seventy (77.7%) of isolates had MIC≥16 and were resistant to imipenem. The results showed that the rate of resistance to imipenem is increasing. Mutations of the upstream of the oprD gene and its promoters were seen in 25 (86.2%) of isolates and 4 strains had no mutation. All of the imipenem-resistant isolates had mutations. One isolate had a base substitution A→ C at nt 25 in coding region and this isolate had a point mutation leading to an amino acid change at positions 9 (I→L). Conclusion: The results showed that imipenem resistance is increasing in P. aeruginosa, also indicated that the point mutations were the most common cause of the inactivation of upstream of the oprD coding region among P. aeruginosa isolates, it seems this mechanism is effective in resistance of isolates to imipenem.


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