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 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 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 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 Characterization of plasmid-mediated qnrA and qnrB genes among Enterobacteriaceae strains: quinolone resistance and ESBL production in Ismailia, Egypt

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Samaa A. Taha ◽  
Hanan Hassan Omar ◽  
wafaa Hassan Hassan
Keyword(s):  
Resistance Genes ◽  
Quinolone Resistance ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
University Hospitals ◽  
Disk Diffusion Method ◽  
Extended Spectrum Beta Lactamase ◽  
Tract Infections ◽  
Resistance Rates

Abstract Background Plasmid-mediated quinolone resistance genes (PMQR) are mainly associated with clinical isolates of Enterobacteriaceae and complicate treatment of infections caused by these isolates worldwide. Extended-spectrum-beta-lactamase (ESBL)-producing bacteria are resistant to common antibiotics and also through many mechanisms, ESBL could be disabling other types of antibiotics. This study aimed to assess the prevalence of quinolone resistance and ESBL among Enterobacteriaceae strains and investigated the presence of qnrA and qnrB genes in these strains which were isolated from urinary tract infections in Ismailia, Egypt. Ninety-four Enterobacteriaceae isolates were collected from cases of UTIs admitted to the intensive care unit, Suez-Canal University Hospitals, between October 2017 and January 2018. Antibacterial susceptibility was determined by the disk diffusion method. A polymerase chain reaction assay was used to detect qnrA and qnrB resistance genes in quinolone- and fluoroquinolone-resistant and ESBL strains. Also, ciprofloxacin MIC was determined by the agar dilution method. Results Resistance rates were 59.6%, 54.3%, 53.2%, 53.2%, and 53.2% to NA, LEV, NOR, CIP, and FX, respectively. Of 56 NA-resistant isolates, 7 (12.5%) and 6 (10.7%) were positive for qnrA and qnrB, respectively, with only one isolate co-harboring both genes. ESBL-producing bacteria was 66.2% of isolates. The MICs for ciprofloxacin ranged from 32–256 μg/ml in ciprofloxacin-resistant isolates. Conclusion Our study shows high resistance rates of Enterobacteriaceae to quinolones and ESBL in our hospital which necessitate appropriate use of these antibiotics to reserve their application for therapy. The prevalence of quinolone-resistant and ESBL-producing Enterobacteriaceae was approximately 60% and 70% respectively.

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 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.

Antibiotic Resistance of Salmonella Isolated from Hog, Beef, and Chicken Carcass Samples from Provincially Inspected Abattoirs in Ontario

2004 ◽  
Vol 67 (3) ◽  
pp. 448-455 ◽  
Author(s):  
C. LARKIN ◽  
C. POPPE ◽  
B. MCNAB ◽  
B. MCEWEN ◽  
A. MAHDI ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
The United States ◽  
Test Methods ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Chicken Carcass ◽  
Resistance Patterns ◽  
Agar Dilution ◽  
Microbroth Dilution ◽  
Good Agreement

The emergence of antimicrobial-resistant Salmonella organisms, especially Salmonella Typhimurium DT104, has been reported in many countries, including the United States and Canada. The purposes of this study were to determine the antimicrobial resistance patterns of Salmonella isolated from hog, beef, and chicken carcasses from provincially inspected abattoirs in Ontario and to determine the agreement between the agar dilution method and the microbroth dilution method for measurement of antimicrobial resistance of the isolates. Antimicrobial resistance of Salmonella isolates from hogs (n = 71), beef (n = 24), and chicken (n = 295) to amikacin, ampicillin, cephalothin, chloramphenicol, ciprofloxacin, gentamicin, streptomycin, sulfamethoxazole,and tetracycline was determined using the two methods. None of the 390 isolates were resistant to ciprofloxacin at levels of 0.125 μg/ml. All chicken and hog isolates were sensitive to amikacin, whereas all beef isolates were sensitive to both amikacin and gentamicin. Multiple antimicrobial resistance (resistance to more than one antimicrobial) was found in 29% of bovine isolates and 42% of porcine isolates using both methods for testing and in 42% by the agar dilution and 33% by the microbroth dilution methods in the chicken isolates. Overall, there was good agreement between the two test methods for resistance to most of the antimicrobials, with disagreement found in the results in 1.3% of the isolates for ampicillin and sulfamethoxazole, 8.2% for streptomycin, 5.6% for cephalothin, and 1.0% of the isolates for tetracycline. The lack of agreement between the two test methods was found mostly among the chicken isolates.

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.

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