scholarly journals Antibiotic Susceptibility Profile of Clostridium Difficile Bacteria Isolated from Older Residents of a Nursing Home in Iran

Salmand ◽  
2021 ◽  
Vol 15 (4) ◽  
pp. 496-505
Author(s):  
Ahmad Ghasemi ◽  
◽  
Ashraf Mohabati Mobarez ◽  
Ehsan Mostafavi ◽  
◽  
...  
Keyword(s):  
Nursing Home ◽  
Clostridium Difficile ◽  
Antibiotic Susceptibility ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disk Diffusion Method ◽  
Nosocomial Diarrhea ◽  
Agar Dilution

Objectives: Clostridium difficile (C. diff) is a gram-positive anaerobic bacterium knwon as the most common cause of nosocomial diarrhea in nursing homes. The antibiotic susceptibility profile is the basic way for successful treatment due to antimicrobial resistance. This present study aims to assess the antibiotic susceptibility profile of C. diff isolated from older residents of a nursing home in Tehran, Iran. Methods & Materials: Forty-two isolates of C. diff were used in this study collected from 289 residents of Kahrizak Nursing Home. Antibiotic susceptibility testing was conducted by using disk-diffusion method, agar dilution method, and Epsilometer test (E-test). Results: All C. diff strains were susceptible to Metronidazole, Vancomycin, Rifampicin, Linezolid and Tigecycline. By using the disk-diffusion method, the highest rate of resistance was related to Clindamycin (100%), Levofloxacin (96.2%), Imipenem (81%), Azithromycin (61%) and Erythromycin (54.8%). All C. diff strains were susceptible to Metronidazole under E-test. Furthermore, 100% and 59.5% of strains were susceptible to Vancomycin and Erythromycin, respectively under agar dilution test. Conclusion: C. diff strains are sensitive to Vancomycin and Metronidazole. These two antibiotics can be used to treat C. diff infections in older adults. The disk diffusion method can be used as a screening test to determine antibiotic resistance.

scholarly journals Comparison of methods for the determination of antimicrobial resistance in Campylobacter spp. human and the food chain isolates

2008 ◽  
Vol 52 (No. 4) ◽  
pp. 169-174
Author(s):  
M. Holasova ◽  
R. Karpiskova ◽  
S. Karpiskova ◽  
V. Babak ◽  
J. Schlegelova
Keyword(s):  
Nalidixic Acid ◽  
Antimicrobial Agents ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disk Diffusion Method ◽  
Microdilution Method ◽  
Study Results ◽  
Agar Dilution

With a microdilution method, using the commercial diagnostic test Sensititre Susceptibility Plates for Campylobacter MIC (Trek Diagnostic Systems, Cleveland, OH, USA), disk diffusion and agar dilution method, resistance to six antimicrobial agents were examined in a reference strain <i>Campylobacter jejuni</i> ATCC 33560 and 73 thermo-tolerant isolates of <i>Campylobacter</i> spp. For the microdilution method and all tested antimicrobial agents, our determined values of microbiological breakpoints of resistant strains were suggested as the minimum inhibitory concentration (MIC<sub>R</sub>) for ciprofloxacin &ge; 0.5, erythromycin &ge; 4, gentamicin &ge; 4, nalidixic acid &ge; 32 and tetracycline &ge; 4 &mu;g/ml. On the basis of our study results, strains resistant to clindamycin were MIC<sub>R</sub> &ge; 2 &mu;g/ml for the dilution methods and a zone diameter R ≤ 16 mm for the disk diffusion method. Comparison of the results of the resistance examination, a microdilution method and disk diffusion method with the reference agar dilution method, showed that all compared methods yielded identical results with the exception of the resistance determination in erythromycin and nalidixic acid. The errors were mostly the result of the interpretation criteria for MIC<sub>R</sub> of agar dilution method and different conditions of cultivation used. However, the compared methods, provide results comparable with the reference method having greater convenience of measurement.

scholarly journals Inaccuracy of the Disk Diffusion Method Compared with the Agar Dilution Method for Susceptibility Testing of Campylobacter spp.

2011 ◽  
Vol 50 (1) ◽  
pp. 52-56 ◽  
Author(s):  
Mirva Lehtopolku ◽  
Pirkko Kotilainen ◽  
Pauli Puukka ◽  
Ulla-Maija Nakari ◽  
Anja Siitonen ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disk Diffusion Method ◽  
Agar Dilution ◽  
Campylobacter Spp

scholarly journals Comparative Analysis of Gradient Diffusion and Disk Diffusion with Agar Dilution for Susceptibility Testing of Elizabethkingia anophelis

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 450
Author(s):  
Chien-Tung Chiu ◽  
Chung-Hsu Lai ◽  
Yi-Han Huang ◽  
Chih-Hui Yang ◽  
Jiun-Nong Lin
Keyword(s):  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disk Diffusion Method ◽  
Gradient Diffusion ◽  
Minimum Requirements ◽  
Agar Dilution

Elizabethkingia anophelis has recently emerged as a cause of life-threatening infections. This study compared the results of antimicrobial susceptibility testing (AST) conducted for E. anophelis through different methods. E. anophelis isolates collected between January 2005 and June 2019 were examined for their susceptibility to 14 antimicrobial agents by using disk diffusion, gradient diffusion (Etest; (bioMérieux S.A., Marcy l’Etoile, France), and agar dilution methods. The agar dilution method was the reference assay. According to the agar dilution method, the isolates exhibited the highest susceptibility to minocycline (100%), doxycycline (97.6%), rifampin (95.2%), and levofloxacin (78.6%). A very major error rate of >1.5% was observed for nine antibiotics tested using the disk diffusion method. The overall categorical agreement rate between the disk diffusion and agar dilution methods was 74.8%, and ceftazidime, minocycline, levofloxacin, and rifampin met the minimum requirements for discrepancy and agreement rates. The Etest method tended to produce lower log2 minimum inhibitory concentrations for the antibiotics, except for trimethoprim–sulfamethoxazole and rifampin; the method resulted in very major errors for nine antibiotics. The overall essential and categorical agreement rates between the Etest and agar dilution methods were 67.3% and 76.1%, respectively. The Etest method demonstrated acceptable discrepancy and agreement rates for ceftazidime, minocycline, doxycycline, levofloxacin, and rifampin. AST results obtained through the disk diffusion and Etest methods for multiple antibiotics differed significantly from those obtained using the agar dilution method. These two assays should not be a routine alternative for AST for E. anophelis.

scholarly journals Molecular identification and antimicrobial resistance profiles of Campylobacter strains of poultry origin in India with special emphasis on fluoroquinolone resistance

2015 ◽  
Vol 1 (1) ◽  
pp. 1-8
Author(s):  
SM Lutful Kabir ◽  
Masahiro Asakura ◽  
Sachi Shiramaru ◽  
Amit Pal ◽  
Atsushi Hinenoya ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Quinolone Resistance ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Slight Variation ◽  
Gyra Gene ◽  
Disk Diffusion Method ◽  
Agar Dilution

The current study aimed to identify the selected number of Campylobacter strains of poultry origin in India that were isolated in the Laboratory of International Prevention of Epidemics, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Japan to the species level with the aid of cdtA/B/C gene-based multiplex PCR assays as well as to investigate their antimicrobial resistance profiles. C. jejuni (4 strains) and C. coli (16 strains) were identified. The poultry isolates identified were subjected to susceptibility testing with the aid of disk diffusion method using 12 antimicrobial agents. Again, the resistant and intermediate isolates confirmed by the disk diffusion method were subjected to determination of minimum inhibitory concentration by agar dilution method. To elucidate the mechanism of quinolone resistance, a total number of 20 quinolone resistant strains were subjected to sequence determination and analysis of the gyrA gene in the quinolone-resistance determining region. The results of the disk diffusion method were consistent with the results of the agar dilution method with slight variation in case of ampicillin, levofloxacin, ofloxacin and fosfomycin. All C. jejuni and C. coli strains had the Thr 86 to Ile substitution in gyrA. Results of this study support the emergence of resistance of C. jejuni and C. coli strains of poultry origin in India to a variety of antimicrobials especially fluoroquinolones.Asian J. Med. Biol. Res. June 2015, 1(1): 1-8

scholarly journals Antimicrobial Susceptibilities and Serogroups of Clinical Strains of Clostridium difficile Isolated in France in 1991 and 1997

1999 ◽  
Vol 43 (11) ◽  
pp. 2607-2611 ◽  
Author(s):  
Frédéric Barbut ◽  
Dominique Decré ◽  
Béatrice Burghoffer ◽  
Danièle Lesage ◽  
Françoise Delisle ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
Clinical Laboratory ◽  
Major Change ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
National Committee ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disk Diffusion Method ◽  
Therapeutic Drugs

ABSTRACT Glycopeptides (vancomycin and teicoplanin) and metronidazole are the drugs of choice for the treatment of Clostridium difficile infections, but trends in susceptibility patterns have not been assessed in the past few years. The objective was to study the MICs of glycopeptides and metronidazole for unrelated C. difficile strains isolated in 1991 (n = 100) and in 1997 (n = 98) by the agar macrodilution, the E-test, and the disk diffusion methods. Strain susceptibilities to erythromycin, clindamycin, tetracycline, rifampin, and chloramphenicol were also determined by the ATB ANA gallery (bioMérieux, La Balme-les-Grottes, France). The MICs at which 50% of isolates are inhibited (MIC50s) and MIC90s of glycopeptides and metronidazole remained stable between 1991 and 1997. All the strains were inhibited by concentrations that did not exceed 2 μg/ml for vancomycin and 1 μg/ml for teicoplanin. Comparison of MICs determined by the agar dilution method recommended by the National Committee for Clinical Laboratory Standards and the E test showed correlations (±2 dilutions) of 86.6, 95.9, and 99% for metronidazole, vancomycin, and teicoplanin, respectively. The E test always underestimated the MICs. Strains with decreased susceptibility to metronidazole (MICs, ≥8 μg/ml) were isolated from six patients (n = 4 in 1991 and n = 2 in 1997). These strains were also detected by the disk diffusion method (zone inhibition diameter, ≤21 mm); they belonged to nontoxigenic serogroup D (n = 5) and toxigenic serogroup H (n = 1). Decreased susceptibility to erythromycin (MICs, ≥1 μg/ml), clindamycin (MICs, ≥2 μg/ml), tetracycline (MICs, ≥8 μg/ml), rifampin (MICs, ≥4 μg/ml), and chloramphenicol (MICs, ≥16 μg/ml) was observed in 64.2, 80.3, 23.7, 22.7, and 14.6% of strains, respectively. Strains isolated in 1997 were more susceptible than those isolated in 1991, and this trend was correlated to a major change in serogroup distribution. Periodic studies are needed in order to detect changes in serogroups and the emergence of strains with decreased susceptibility to therapeutic drugs.

scholarly journals Detection of Plasmid-Mediated Colistin Resistant mcr-1 Gene in Escherichia coli Isolated from Infected Chicken Livers in Nepal

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2060
Author(s):  
Sayara Bista ◽  
Upendra Thapa Shrestha ◽  
Binod Dhungel ◽  
Pragya Koirala ◽  
Tulsi Ram Gompo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Conventional Polymerase Chain Reaction ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Human Pathogens ◽  
Colistin Resistance ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Agar Dilution

Background: Plasmid-mediated resistance to the colistin in poultry is considered as an emerging problem worldwide. While poultry constitutes the major industry in Nepal, there is a paucity of evidence on colistin resistance in Escherichia coli isolates causing natural infections in poultry. This study aimed to explore the prevalence of plasmid-mediated colistin resistance gene, mcr-1 in E. coli isolated from liver samples of dead poultry suspected of E. coli infections. Methods: A total of two hundred and seventy liver samples (227 broilers and 43 layers) from dead poultry suspected of colibacillosis were collected from post-mortem in the Central Veterinary Laboratory (CVL), Kathmandu, between 1 February and 31 July 2019. The specimens were processed to isolate and identify E. coli; an antimicrobial susceptibility test (AST) using disk diffusion method was performed with 12 different antibiotics: Amikacin (30 µg), ampicillin (10 µg), ciprofloxacin (5 µg), chloramphenicol (30 µg), cefoxitin (30 µg), ceftazidime (30 µg), ceftriaxone (30 µg), cotrimoxazole (25 µg), gentamicin (10 µg), imipenem (10 µg), levofloxacin (5 µg) and tetracycline (30 µg). Colistin resistance was determined by agar dilution method and colistin-resistant strains were further screened for plasmid-mediated mcr-1 gene, using conventional polymerase chain reaction (PCR). Results: Out of 270 liver samples, 53.3% (144/270) showed growth of E. coli. The highest number (54%; 109/202) of E. coli isolates was obtained in the liver samples from poultry birds (of both types) aged less than forty days. In AST, 95.1% (137/144) and 82.6% (119/144) of E. coli isolates were resistant against tetracycline and ciprofloxacin, respectively, while 13.2% (19/144) and 25.7% (37/144) isolates were resistant to cefoxitin and imipenem, respectively. In the same assay, 76.4% (110/144) E. coli isolates were multi-drug resistant (MDR). The phenotypic prevalence of colistin resistance was 28.5% (41/144). In the PCR assay, 43.9% (18/41) of colistin-resistant isolates were screened positive for plasmid-mediated mcr-1. Conclusion: The high prevalence of mcr-1 in colistin-resistant E. coli isolates in our study is a cause of concern for the probable coming emergence of colistin resistance in human pathogens, due to horizontal transfer of resistant genes from poultry to human isolates.

scholarly journals Differences in the Molecular Epidemiology and Antibiotic Susceptibility of Clostridium difficile Isolates in Pediatric and Adult Patients

2016 ◽  
Vol 60 (8) ◽  
pp. 4896-4900 ◽  
Author(s):  
Larry K. Kociolek ◽  
Dale N. Gerding ◽  
James R. Osmolski ◽  
Sameer J. Patel ◽  
David R. Snydman ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
Antibiotic Susceptibility ◽  
Restriction Endonuclease Analysis ◽  
Adult Patients ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Content Type ◽  
Agar Dilution ◽  
Rising Incidence ◽  
Antibiotics Susceptibility

ABSTRACTThe rising incidence ofClostridium difficileinfections (CDIs) in adults is partly related to the global spread of fluoroquinolone-resistant strains, namely, BI/NAP1/027. Although CDIs are also increasingly diagnosed in children, BI/NAP1/027 is relatively uncommon in children. Little is known about the antibiotic susceptibility of pediatric CDI isolates.C. difficilewas cultured fromtcdB-positive stools collected from children diagnosed with CDI between December 2012 and December 2013 at an academic children's hospital. CDI isolates were grouped by restriction endonuclease analysis (REA). MICs were measured by agar dilution method for 7 antibiotics. Susceptibility breakpoints were based on guidelines from CLSI and/or the European Committee on Antimicrobial Susceptibility Testing (EUCAST). MICs and REA groupings ofC. difficileisolates from 74 adult patients (29 isolates underwent REA) from a temporally and geographically similar adult cohort were compared to those of pediatric isolates. Among 122 pediatric and 74 adult isolates, respectively, the rates of resistance were as follows: metronidazole, 0% and 0%; vancomycin, 0% and 8% (P= 0.003); rifaximin, 1.6% and 6.7% (P= 0.11); clindamycin, 18.9% and 25.3% (P= 0.29); and moxifloxacin, 2.5% and 36% (P= <0.0001). Only 1 of 122 (0.8%) BI/NAP1/027 isolates was identified among the children, compared to 9 of 29 (31%) isolates identified among the adults (P= <0.0001). The 3 moxifloxacin-resistant pediatric isolates were of REA groups BI and CF and a nonspecific group. The 2 rifaximin-resistant pediatric isolates were of REA groups DH and Y. The 21 clindamycin-resistant pediatric isolates were distributed among 9 REA groups (groups A, CF, DH, G, L, M, and Y and 2 unique nonspecific REA groups). These data suggest that a diverse array of relatively antibiotic-susceptibleC. difficilestrains predominate in a cohort of children with CDI compared to adults.

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 The study of reduced susceptibility of methicillin resistant Staphylococcus aureus to various antibiotics with special reference to glycopeptides in a tertiary care hospital in central India

2019 ◽  
Vol 6 (4) ◽  
pp. 1426
Author(s):  
Swati S. Kale ◽  
Ashwini Patil
Keyword(s):  
Staphylococcus Aureus ◽  
Tertiary Care ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Care Hospital ◽  
Diagnostic Laboratory ◽  
Disk Diffusion Method ◽  
Methicillin Resistant ◽  
Agar Dilution

Background: Staphylococcus aureus has emerged over the past several decades as a leading cause of hospital-associated and community acquired infections. Methicillin resistant S. aureus (MRSA), which are often resistant to several classes of antibiotics, is the most common cause of nosocomial infections and pose a great threat to the world. Vancomycin is regarded as the first-line drug for treatment of MRSA but resistance to this drug is being reported now a day.Methods: It was carried out for a period between January 2014 to June 2017 in the microbiology diagnostic laboratory. MRSA detection was performed by cefoxitin disk diffusion method. Screening for the vancomycin intermediate and the vancomycin resistant S. aureus (VISA and VRSA respectively) was carried out by using vancomycin screen. MIC (minimum inhibitory concentration) of vancomycin was tested by agar dilution method and E strip on all MRSA isolates.Results: A total of 287 S. aureus clinical isolates were included in the study. All MRSA were inoculated on vancomycin screen agar. Visible growth was present in 8 isolates. Five (3.73%) MRSA isolates with MIC of 4 were termed VISA (vancomycin intermediate S. aureus) by agar dilution method. Six isolates had the MIC of 4 and were termed as VISA.Conclusions: As disc diffusion method is not recommended by CLSI for S. aureus, vancomycin screen agar and MIC determination by either of the methods viz. agar dilution or E test can be used.

scholarly journals Antimicrobial Resistance in Salmonella Typhi Isolated From a Referral Hospital of Kathmandu, Nepal

2021 ◽  
Vol 14 ◽  
pp. 117863612110563
Author(s):  
Saroj Khadka ◽  
Basudha Shrestha ◽  
Anil Pokhrel ◽  
Sachin Khadka ◽  
Rajesh Dhoj Joshi ◽  
...  
Keyword(s):  
Typhoid Fever ◽  
Antibiotic Susceptibility ◽  
Large Scale ◽  
Salmonella Typhi ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
First Line ◽  
Disk Diffusion Method

Purpose: The morbidity and mortality due to typhoid fever can be significantly reduced with the use of effective antibiotics. At present, fluoroquinolones, third generation cephalosporins, and azithromycin are widely used to treat typhoid fever. However, changing antibiotic susceptibility among Salmonella Typhi and Salmonella Paratyphi poses a particular challenge to the therapeutic management of enteric fever. The objective of this study was to assess the antibiotic susceptibility pattern of Salmonella Typhi isolates. Patients and Methods: A total of 706 blood specimens were collected from febrile patients attending the outpatient department of Kathmandu Model Hospital during June to September, 2018. The antibiotic susceptibility testing for 11 different antibiotics (nalidixic acid, ciprofloxacin, ofloxacin, levofloxacin, cefixime, ceftriaxone, cefotaxime, azithromycin, cotrimoxazole, chloramphenicol, and amoxicillin) was performed by disk diffusion method. Furthermore, minimum inhibitory concentration (MIC) values of ciprofloxacin, ofloxacin, and azithromycin were determined by agar dilution method. Mutation at gyrA ser83 associated with reduced susceptibility to fluoroquinolones was determined by PCR-RFLP. Results: Out of 706 blood samples, 6.94% (n = 49) were culture positive for Salmonella enterica (S. Typhi, n = 46). It was revealed that 97.8% S. Typhi isolates were susceptible to conventional first-line antibiotics (ampicillin, chloramphenicol, and cotrimoxazole), 97.3% to cephalosporins and 95.7% to azithromycin. S. Typhi were either resistant or intermediately susceptible to fluoroquinolones: 97.8% to ciprofloxacin, 91.3% to ofloxacin, and 89.1% to levofloxacin. The MIC of ciprofloxacin, ofloxacin, and azithromycin for S. Typhi ranged from 0.008 to 32, 0.03 to 16, and 2 to 8 μg/mL, respectively. Out of 46 S. Typhi isolates, 44 (95.65%) had gyrA ser83 mutation. Conclusion: Fluoroquinolones have poor activity against Salmonella Typhi. The trends of increasing azithromycin MIC value among S. Typhi might limit its use for the treatment of typhoid fever. Effectiveness of conventional first-line antibiotics in vitro suggests considering their clinical use after large-scale studies.

Sign in / Sign up

Export Citation Format

Share Document