scholarly journals Occurrence of Antimicrobial Resistance in Fish-Pathogenic and Environmental Bacteria Associated with Four Danish Rainbow Trout Farms

2000 ◽  
Vol 66 (11) ◽  
pp. 4908-4915 ◽  
Author(s):  
Anja S. Schmidt ◽  
Morten S. Bruun ◽  
Inger Dalsgaard ◽  
Karl Pedersen ◽  
Jens L. Larsen
Keyword(s):  
Antimicrobial Agents ◽  
Fish Farming ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Yersinia Ruckeri ◽  
Fish Farms ◽  
Fish Pathogens ◽  
Antibiotic Resistant ◽  
Substantial Impact ◽  
Trout Farms

ABSTRACT Surveillance of bacterial susceptibility to five antimicrobial agents was performed during a 1-year period in and around four freshwater fish farms situated along a stream in western Denmark. Besides assessing the levels of antibiotic resistance among the culturable fraction of microorganisms in fish, water, and sediment samples, two major fish pathogens (88Flavobacterium psychrophilum isolates and 134Yersinia ruckeri isolates) and 313 motileAeromonas isolates, representing a group of ubiquitous aquatic bacteria, were isolated from the same samples. MICs were obtained applying a standardized agar dilution method. A markedly decreased susceptibility of F. psychrophilum isolates to most antimicrobial agents presently available for use in Danish aquaculture was detected, while the collected Y. ruckeriisolates remained largely sensitive to all therapeutic substances. Comparing the inlet and outlet samples, the increase of the antibiotic-resistant proportions observed among the culturable microflora was more pronounced and statistically significant among the motile aeromonads. High levels of individual and multiple antimicrobial resistances were demonstrated within the collected flavobacteria and aeromonads, thus indicating a substantial impact of fish farming on several groups of bacteria associated with aquacultural environments.

scholarly journals Antibacterial Activity of Fresh Red and White Onion (Allium cepa) Extract against Some Drug Resistant Bacteria

2019 ◽  
pp. 1-8
Author(s):  
K. Zikora Anyaegbunam ◽  
L. Ogara Amaechi ◽  
C. AnyaegbunamTito ◽  
O. Oniwon Wisdom ◽  
C. Ogechukwu Henrietta ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Allium Cepa ◽  
Antimicrobial Agents ◽  
Resistant Bacteria ◽  
Antibiotics Resistance ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Antibiotic Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Onion Extract

Antibiotics resistance is currently one of the major challenges in the health care system. The antimicrobial properties of some herbs have been used in the treatment of infectious diseases as well as disinfection of surfaces. This in a way helps overcome microbial resistance arising from indiscriminate use of synthetic antimicrobial agents for similar purpose. Some antibiotic resistant bacteria- Pseudomonas aeruginosa, Staphylococus aureus and Escherichia coli isolated from cooking wares in homes were investigated using agar well diffusion and agar dilution method to test for the antibacterial activity of fresh Allium cepa (onion) extract. All were susceptible to the fresh white and red onion extract except Staphylococus aureus which was susceptible to only the white onion extract. The diameter of zones of inhibition ranged from 2 mm-35 mm. The Minimum Inhibitory Concentration (M. I. C.) and the Minimum Bacterial Concentration (M. B. C.) values of the fresh onion juices against the test bacteria were low ranging from 3.125% v/v – 25.0% v/v. This study indicates that the fresh raw extracts of Allium cepa possess significant antibacterial potency against these antibiotic resistant bacteria.

scholarly journals Antimicrobial activity of honeys from two stingless honeybee species and Apis mellifera (Hymenoptera: Apidae) against pathogenic microorganisms

2014 ◽  
Vol 44 (2) ◽  
pp. 287-290 ◽  
Author(s):  
Carolinie Batista Nobre da Cruz ◽  
Fabio Alessandro Pieri ◽  
Gislene Almeida Carvalho-Zilse ◽  
Patrícia Puccinelli Orlandi ◽  
Carlos Gustavo Nunes-Silva ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Apis Mellifera ◽  
Antimicrobial Agents ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Therapeutic Approaches ◽  
E Coli ◽  
Agar Dilution ◽  
Amazonas State

Honeys are described possessing different properties including antimicrobial. Many studies have presented this activity of honeys produced by Apis mellifera bees, however studies including activities of stingless bees honeys are scarce. The aim of this study was to compare the antimicrobial activity of honeys collected in the Amazonas State from Melipona compressipes, Melipona seminigra and Apis mellifera against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Chromobacterium violaceum, and Candida albicans. Minimum inhibitory concentrations were determined using the agar dilution method with Müller-Hinton agar (for bacteria) or Saboraud agar (for yeast). Staphylococcus aureus and E. faecalis were inhibited by all honeys at concentrations below 12%, while E. coli and C. violaceum were inhibited by stingless bee honeys at concentrations between 10 and 20%. A. mellifera honey inhibited E. coli at a concentration of 7% and Candida violaceum at 0.7%. C. albicans were inhibited only with honey concentrations between 30 and 40%. All examined honey had antimicrobial activity against the tested pathogens, thus serving as potential antimicrobial agents for several therapeutic approaches.

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 Novel Antibiotic Susceptibility Tests by the ATP-Bioluminescence Method Using Filamentous Cell Treatment

1998 ◽  
Vol 42 (6) ◽  
pp. 1406-1411 ◽  
Author(s):  
Noriaki Hattori ◽  
Moto-O Nakajima ◽  
Koji O’Hara ◽  
Tetsuo Sawai
Keyword(s):  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Test Model ◽  
The Novel ◽  
Gram Negative ◽  
Atp Bioluminescence ◽  
Filamentous Cell ◽  
Bioluminescence Method

ABSTRACT Antimicrobial susceptibility testing by the ATP-bioluminescence method has been noted for its speed; it provides susceptibility results within 2 to 5 h. However, several disagreements between the ATP method and standard methodology have been reported. The present paper describes a novel ATP method in a 3.5-h test which overcomes these deficiencies through the elimination of false-resistance discrepancies in tests on gram-negative bacteria with β-lactam agents. In our test model using Pseudomonas aeruginosa and piperacillin, it was shown that ATP in filamentous cells accounted for the false resistance. We found that 0.5% 2-amino-2-methyl-1,3-propanediol (AMPD) extracted ATP from the filamentous cells without affecting normal cells and that 0.3 U of adenosine phosphate deaminase (APDase)/ml simultaneously digested the extracted ATP. We used the mixture of these reagents for the pretreatment of cells in a procedure we named filamentous cell treatment, prior to ATP measurements. This novel ATP method with the filamentous cell treatment eliminated false-resistance discrepancies in tests on P. aeruginosa with β-lactam agents, including piperacillin, cefoperazone, aztreonam, imipenem-cilastatin, ceftazidime, and cefsulodin. Furthermore, this novel methodology produced results which agreed with those of the standard microdilution method in other tests on gram-negative and gram-positive bacteria, including P. aeruginosa, Escherichia coli,Staphylococcus aureus, and Enterococcus faecalis, for non-β-lactam agents, such as fosfomycin, ofloxacin, minocycline, and aminoglycosides. MICs obtained by the novel ATP method were also in agreement with those obtained by the agar dilution method of susceptibility testing. From these results, it was shown that the novel ATP method could be used successfully to test the activities of antimicrobial agents with the elimination of the previously reported discrepancies.

scholarly journals In Vitro Antimicrobial Susceptibility Testing of Bacterial Enteropathogens Causing Traveler's Diarrhea in Four Geographic Regions

2001 ◽  
Vol 45 (1) ◽  
pp. 212-216 ◽  
Author(s):  
Harumi Gomi ◽  
Zhi-Dong Jiang ◽  
Javier A. Adachi ◽  
David Ashley ◽  
Brett Lowe ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Antimicrobial Agents ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Moderate Activity ◽  
Traveler’S Diarrhea ◽  
The World ◽  
Traveler's Diarrhea ◽  
Susceptibility Patterns

ABSTRACT The emergence of resistant enteropathogens has been reported worldwide. Few data are available on the contemporary in vitro activities of commonly used antimicrobial agents against enteropathogens causing traveler's diarrhea (TD). The susceptibility patterns of antimicrobial agents currently available or under evaluation against pathogens causing TD in four different areas of the world were evaluated. Pathogens were identified in stool samples from U.S., Canadian, or European adults (18 years of age or older) with TD during 1997, visiting India, Mexico, Jamaica, or Kenya. MICs of 11different antimicrobials were determined against 284 bacterial enteropathogens by the agar dilution method. Ciprofloxacin, levofloxacin, ceftriaxone, and azithromycin were highly active in vitro against the enteropathogens, while traditional antimicrobials such as ampicillin, trimethoprim, and trimethoprim/sulfamethoxazole showed high levels and high frequencies of resistance. Rifaximin, a promising and poorly absorbable drug, had an MIC at which 90% of the strains tested were inhibited of 32 μg/ml, 250 times lower than the concentration of this drug in the stools. Amdinocillin, nalidixic acid, and doxycycline showed moderate activity. Fluoroquinolones are still the drugs of choice for TD in most regions of the world, although our study has a limitation due to the lack of Escherichia coli samples from Kenya and possible bias in selection of the patients for evaluation. Azithromycin and rifaximin should be considered as promising new agents. The widespread in vitro resistance of the traditional antimicrobial agents reported since the 1980s and the new finding of resistance to fluoroquinolones in Southeast Asia are the main reasons for monitoring carefully the antimicrobial susceptibility patterns worldwide and for developing and evaluating new antimicrobial agents for the treatment of TD.

scholarly journals Assessment of physico-chemical parameters of rainbow trout farms for the evaluation of potential threat to natural streams in Nepal

2017 ◽  
Vol 6 (2) ◽  
pp. 43-55
Author(s):  
Payaswini Ghimire ◽  
Archana Niraula ◽  
Anuradha Rai ◽  
Aastha Pandey ◽  
Smriti Gurung ◽  
...  
Keyword(s):  
Environmental Protection Agency ◽  
Major Ions ◽  
Fish Farming ◽  
Small Scale ◽  
Chemical Parameters ◽  
Fish Farms ◽  
Potential Threat ◽  
Physico Chemical ◽  
Natural Streams ◽  
Trout Farms

 Three trout farms from Nepal were studied to investigate the changes in physico-chemical parameters and their potential threat to natural water bodies receiving the effluents. Reference and impact sites were determined in each farm so as to find out the level of impacts due to farming activities. Some of the parameters such as dissolved oxygen, turbidity, conductivity, and total dissolve solids were significantly changed in the impacted zones compared to reference sites. Similarly, concentrations of some major ions such as calcium and sodium were increased in the impacted zones. On the other hand, some of the parameters such as pH and potassium did not change in the impacted zone although their concentrations were different among farms studied. Nevertheless, the overall changes in the physico-chemical parameters did not pose health risk to the aquatic ecosystems receiving effluents from these fish farms as the concentrations were below the prescribed levels by Environmental Protection Agency (EPA) as well as Nepal Environment Statistics. This is an indication that, although fish farming activities are degrading water qualities, there is no threat to the water quality receiving the effluents yet probably due to small scale farming. The increase in number of fish farms in the same area, however might pose risk to the ecological health in the region which warrants regular monitoring.  INTERNATIONAL JOURNAL OF ENVIRONMENTVolume-6, Issue-2, Mar-May 2017, Page: 43-55

scholarly journals Telithromycin- and Fluoroquinolone-Resistant Streptococcus pneumoniae in Taiwan with High Prevalence of Resistance to Macrolides and β-Lactams: SMART Program 2001 Data

2003 ◽  
Vol 47 (7) ◽  
pp. 2145-2151 ◽  
Author(s):  
Po-Ren Hsueh ◽  
Lee-Jene Teng ◽  
Tsu-Lan Wu ◽  
Dine Yang ◽  
Wen-Kuei Huang ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Antimicrobial Agents ◽  
Random Amplified Polymorphic Dna ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Time Period ◽  
High Prevalence ◽  
Agar Dilution ◽  
Different Parts

ABSTRACT There is a high prevalence of β-lactam- and macrolide-resistant Streptococcus pneumoniae in Taiwan. To understand the in vitro susceptibilities of recent isolates of S. pneumoniae to fluoroquinolones and telithromycin (which is not available in Taiwan), the MICs of 23 antimicrobial agents for 936 clinical isolates of S. pneumoniae isolated from different parts of Taiwan from 2000 to 2001 were determined by the agar dilution method. Overall, 72% of isolates were not susceptible to penicillin (with 61% being intermediate and 11% being resistant) and 92% were resistant to erythromycin. Telithromycin MICs were ≥1 μg/ml for 16% of the isolates, and for 99% of these isolates the MICs of all macrolides tested were ≥256 μg/ml; all of these isolates had the constitutive macrolide-lincosamide-streptogramin B phenotype. Eighty-eight percent of the isolates were resistant to three or more classes of drugs. The ciprofloxacin MICs were ≥4 μg/ml for six (0.6%) isolates from five patients collected in 2000 and 2001, and the levofloxacin MICs were ≥8 μg/ml for five of these isolates. Seven isolates for which ciprofloxacin MICs were ≥4 μg/ml, including one isolate recovered in 1999, belonged to three serotypes (serotype 19F, five isolates; serotype 23A, one isolate; and serotype 23B, one isolate). The isolates from the six patients for which ciprofloxacin MICs were ≥4 μg/ml had different pulsed-field gel electrophoresis profiles and random amplified polymorphic DNA patterns, indicating that no clonal dissemination occurred over this time period. Despite the increased rate of fluoroquinolone use, the proportion of pneumococcal isolates for which ciprofloxacin MICs were elevated (≥4 μg/ml) remained low. However, the occurrence of telithromycin resistance is impressive and raises concerns for the future.

scholarly journals Transformation of the Antibacterial Agent Norfloxacin by Environmental Mycobacteria

2006 ◽  
Vol 72 (9) ◽  
pp. 5790-5793 ◽  
Author(s):  
Michael D. Adjei ◽  
Thomas M. Heinze ◽  
Joanna Deck ◽  
James P. Freeman ◽  
Anna J. Williams ◽  
...  
Keyword(s):  
High Performance ◽  
Antimicrobial Agents ◽  
Resistance Mechanism ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Resonance Spectroscopy ◽  
Environmental Mycobacteria ◽  
Yeast Extract Medium ◽  
Agar Dilution ◽  
Total Absorbance

ABSTRACT Because fluoroquinolone antimicrobial agents may be released into the environment, the potential for environmental bacteria to biotransform these drugs was investigated. Eight Mycobacterium sp. cultures in a sorbitol-yeast extract medium were dosed with 100 μg ml−1 of norfloxacin and incubated for 7 days. The MICs of norfloxacin for these strains, tested by an agar dilution method, were 1.6 to 25 μg ml−1. Cultures were extracted with ethyl acetate, and potential metabolites in the extracts were purified by high-performance liquid chromatography. The metabolites were identified using mass spectrometry and nuclear magnetic resonance spectroscopy. N-Acetylnorfloxacin (5 to 50% of the total absorbance at 280 nm) was produced by the eight Mycobacterium strains. N-Nitrosonorfloxacin (5 to 30% of the total absorbance) was also produced by Mycobacterium sp. strain PYR100 and Mycobacterium gilvum PYR-GCK. The MICs of N-nitrosonorfloxacin and N-acetylnorfloxacin were 2- to 38- and 4- to 1,000-fold higher, respectively, than those of norfloxacin for several different bacteria, including the two strains that produced both metabolites. Although N-nitrosonorfloxacin had less antibacterial activity, nitrosamines are potentially carcinogenic. The biotransformation of fluoroquinolones by mycobacteria may serve as a resistance mechanism.

scholarly journals Comparison of Broth Microdilution Method UsingHaemophilus Test Medium and Agar Dilution Method for Susceptibility Testing of Eikenella corrodens

1998 ◽  
Vol 36 (8) ◽  
pp. 2386-2388 ◽  
Author(s):  
Luis Alcalá ◽  
Fernando García-Garrote ◽  
Emilia Cercenado ◽  
Teresa Peláez ◽  
Gema Ramos ◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Broth Microdilution ◽  
Test Medium ◽  
Eikenella Corrodens ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Agar Dilution

Susceptibility testing of Eikenella corrodens is usually performed by a Mueller-Hinton sheep blood agar dilution (AD) method. However, this method is impractical for testing only a few strains. We compared AD with the broth microdilution method usingHaemophilus test medium (HTM) in order to determine the susceptibility of 36 clinical isolates of E. corrodens to eight antimicrobial agents. MICs obtained by the HTM method yielded 95.5 and 84% agreement (within 2 and 1 log2 dilutions, respectively) with those obtained by AD. The HTM method with incubation in CO2 for 48 h was highly reproducible and constitutes an easy alternative for antimicrobial susceptibility testing of E. corrodens.

scholarly journals Isolation and Antimicrobial Activities of Phytochemicals from Parinari curatellifolia (Chrysobalanaceae)

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Phillip Mawire ◽  
Winnie Mozirandi ◽  
Matthias Heydenreich ◽  
Godloves Fru Chi ◽  
Stanley Mukanganyama
Keyword(s):  
Antimicrobial Agents ◽  
Gradient Elution ◽  
Antimicrobial Activities ◽  
Dilution Method ◽  
Antibiotic Resistant ◽  
Parinari Curatellifolia ◽  
Pure Compounds ◽  
Ethanol Extracts ◽  
Isolated Compound

The widespread use of antimicrobial agents to treat infectious diseases has led to the emergence of antibiotic resistant pathogens. Plants have played a central role in combating many ailments in humans, and Parinari curatellifolia has been used for medicinal purposes. Seven extracts from P. curatellifolia leaves were prepared using serial exhaustive extraction of nonpolar to polar solvents. The microbroth dilution method was used to evaluate antimicrobial bioactivities of extracts. Five of the extracts were significantly active against at least one test microbe. Mycobacterium smegmatis was the most susceptible to most extracts. The methanol and ethanol extracts were the most active against M. smegmatis with an MIC of 25 µg/mL. The hexane extract was the most active against Candida krusei with an MIC of 25 µg/mL. None of the extracts significantly inhibited growth of Klebsiella pneumoniae and Staphylococcus aureus. Active extracts were selected for fractionation and isolation of pure compounds using gradient elution column chromatography. TLC analyses was carried out for pooling fractions of similar profiles. A total of 43 pools were obtained from 428 fractions. Pools 7 and 10 were selected for further isolation of single compounds. Four compounds, Pc4963r, Pc4962w, Pc6978p, and Pc6978o, were isolated. Evaluation of antimicrobial activities of Pc4963r, Pc4962w, and Pc6978p showed that the compounds were most active against C. krusei with MFC values ranging from 50 to 100 µg/mL. Only Pc6978p was shown to be pure. Using spectroscopic analyses, the structure of Pc6978p was determined to be β-sitosterol. The antifungal effects of β-sitosterol were evaluated against C. krusei in vitro and on fabrics. Results showed that β-sitosterol reduced the growth of C. krusei attached to Mendy fabric by 83%. Therefore, P. curatellifolia can be a source of lead compounds for prospective development of novel antimicrobial agents. Further work needs to be done to improve the antifungal activity of the isolated compound using quantitative structure-activity relationships.

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