Impediometric Detection of Campylobacter coli

2002 ◽  
Vol 65 (10) ◽  
pp. 1660-1662 ◽  
Author(s):  
JOHN E. MOORE ◽  
ROBERT H. MADDEN
Keyword(s):  
Yeast Extract ◽  
Brain Heart Infusion ◽  
Campylobacter Coli ◽  
Growth Substrate ◽  
Wild Type ◽  
Mueller Hinton ◽  
Impedance Technique ◽  
The Media ◽  
Charged Ions ◽  
Mueller Hinton Broth

The rapid automated bacterial impedance technique (RABIT) was examined as a method for the detection of two wild-type isolates of Campylobacter coli in broth media. Both isolates failed to produce a change in impedance that was sufficient for detection in any combination of six nonselective basal broth media, including Mueller-Hinton broth, nutrient broth no. 2, brain heart infusion broth supplemented with yeast extract (0.5% [wt/vol]), brucella broth, Campy broth supplemented with yeast extract (0.5% [wt/vol]), and Whitley impedance broth, at 37 and 42°C. Although the strains did proliferate in the media, changes in conductivity were very small (ranging from 0 to 1,000 μS) and were not significantly greater than the drift in conductance observed in the control broth medium. Additional work is therefore required to define a nonionic growth substrate that will produce charged ions upon metabolism that are detectable by RABIT.

scholarly journals Tigecycline MIC Testing by Broth Dilution Requires Use of Fresh Medium or Addition of the Biocatalytic Oxygen-Reducing Reagent Oxyrase To Standardize the Test Method

2005 ◽  
Vol 49 (9) ◽  
pp. 3903-3909 ◽  
Author(s):  
Patricia A. Bradford ◽  
Peter J. Petersen ◽  
Mairead Young ◽  
C. Hal Jones ◽  
Mark Tischler ◽  
...  
Keyword(s):  
Standardized Test ◽  
Culture Collection ◽  
Fresh Medium ◽  
Test Method ◽  
Chromatography Analysis ◽  
Mueller Hinton ◽  
Early Peak ◽  
The Media ◽  
Time Kill ◽  
Mueller Hinton Broth

ABSTRACT Tigecycline is a broad-spectrum glycylcycline antibiotic with activity against not only susceptible gram-positive and gram-negative pathogens but also strains that are resistant to many other antibiotics. In the process of determining quality control (QC) limits for the American Type Culture Collection reference strains for tigecycline, a number of inconsistencies in MICs were encountered which appeared to be related to the age of the Mueller-Hinton broth (MHB) medium used in the MIC testing. The objective of this study was to determine the cause of the discrepant MIC results between fresh and aged MHB. The MICs of tigecycline were determined in MHB that was either prepared fresh (<12 h old), prepared and stored at 4°C, stored at room temperature, stored anaerobically, or supplemented with the biocatalytic oxygen-reducing reagent Oxyrase. When tested in fresh media, tigecycline was 2 to 3 dilutions more active against the CLSI-recommended QC strains compared to aged media (MICs of 0.03 to 0.25 and 0.12 to 0.5 μg/ml, respectively). Media aged under anaerobic conditions prior to testing or supplemented with Oxyrase resulted in MICs similar to those obtained in fresh medium (MICs of 0.03 to 0.12 and 0.03 to 0.25 μg/ml, respectively). Time-kill kinetics demonstrated a >3 log10 difference in viable growth when tigecycline was tested in fresh or Oxyrase-supplemented MHB compared to aged MHB. High-pressure liquid chromatography analysis revealed the accumulation of an early peak (oxidative by-product of tigecycline) to be 3.5% in fresh media and 25.1% in aged media after 24 h and that addition of Oxyrase prevented the accumulation of this oxidized by-product. These results suggested that the activity of tigecycline was affected by the amount of dissolved oxygen in the media. The use of fresh MHB or supplementation with Oxyrase resulted in a more standardized test method for performing MIC tests with tigecycline.

scholarly journals Method for evaluating broth culture media: application to Haemophilus

1978 ◽  
Vol 8 (5) ◽  
pp. 520-524
Author(s):  
A W Brinkley ◽  
T W Huber
Keyword(s):  
Nicotinamide Adenine Dinucleotide ◽  
Research Laboratory ◽  
Culture Media ◽  
Nicotinamide Adenine ◽  
Broth Culture ◽  
Mueller Hinton ◽  
The Media ◽  
Growth Promoting ◽  
Mueller Hinton Broth

A method was devised to test the growth-promoting ability of a broth medium. The "dilute to extinction" method determines the inoculum required to develop heavy turbidity in a broth with overnight incubation. A statistical method using Poisson distribution was used to show that a single Haemophilus cell can develop heavy turbidity in an optimal broth. The dilute to extinction method was used to evaluate the shelf life of stored media, to titrate the growth factor requirements of Haemophilus, and to evaluate the use of purified hemin and nicotinamide adenine dinucleotide in a broth medium for the growth of Haemophilus. Of the media tested, the most suitable formulation was Mueller-Hinton broth supplemented with 10 microgram of hemin and 10 microgram of nicotinamide adenine dinucleotide per ml. The dilute to extinction method appears to be especially useful in the development of broth media for fastidious organisms. The method could also be used to assure the quality of other broth media which are required to support the growth of small inocula in the clinical or research laboratory.

Adherence, Invasion, Toxigenic, and Chemotactic Properties of Mexican Campylobacter Strains

2010 ◽  
Vol 73 (11) ◽  
pp. 2093-2098 ◽  
Author(s):  
ISMAEL MALAGÓN ◽  
SANTOS GARCÍA ◽  
NORMA HEREDIA
Keyword(s):  
Public Health ◽  
Campylobacter Jejuni ◽  
Vero Cells ◽  
Campylobacter Coli ◽  
Cytolethal Distending Toxin ◽  
Wild Type ◽  
Mueller Hinton ◽  
Mueller Hinton Agar ◽  
The Difference ◽  
Type Strains

To determine the virulence factors of Mexican wild-type strains of Campylobacter jejuni and Campylobacter coli, 31 wild-type strains were isolated from food and from humans. The production of cytolethal distending toxin and the adherence and invasion capabilities of these strains were assayed in Vero cells. Hard agar plugs with repellents and attractants were used to examine chemotaxis. Mueller-Hinton agar with supplements was used for motility analysis and to measure hemolytic activity. Nine strains of C. jejuni and eight strains of C. coli exhibited motility, most within a diameter of 2 to 13 mm. Most of the strains reacted to the repellent compounds analyzed, and α- and β-like hemolysis and cytotoxicity in Vero cells were observed for all strains. Isolates adhered to and invaded Vero cells to various degrees. Although strains of C. jejuni exhibited stronger adherence but less invasion compared with strains of C. coli, the difference was not significant (P &gt; 0.05). The strains of C. jejuni and C. coli isolated from food and from patients in Mexico could have major impacts on public health.

Induction and reversion of the L-form of Neisseria gonorrhoeae

1973 ◽  
Vol 19 (9) ◽  
pp. 1145-1151 ◽  
Author(s):  
John W. Lawson ◽  
James T. Douglas
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Horse Serum ◽  
Brain Heart Infusion ◽  
Brain Heart Infusion Broth ◽  
Blood Agar ◽  
Broth Culture ◽  
Growth Media ◽  
Agar Block ◽  
Mueller Hinton ◽  
The Media

Massive induction of Neisseria gonorrhoeae to the L-form was achieved on L-media consisting of brain heart infusion broth, 1% agar, 10% horse serum, and 100 units per milliliter penicillin. This medium was supplemented with polyvinylpyrrolidone (PVP) for stabilization. Frequencies greater than 10% were routinely found with all 11 strains tested. Five of the 11 strains were also transformed to the L-form on L-media supplemented with 10% sucrose but at efficiencies much lower than on PVP L-media. Rare L-colonies (less than 1 in 107 gonococci) of these same five strains were also isolated on unstabilized L-media. No L-forms were ever isolated from the remaining six strains on sucrose or on unstabilized L-media. The penicillin concentration in the media, if above a lethal amount, had little effect on the efficiency of L-phase induction on PVP L-media but was critical for isolation on sucrose L-media. Colonial growth of the L-form was much more rapid and luxuriant on PVP than on sucrose L-media. In addition, subculture by the agar-block technique of L-phase colonies induced on PVP L-media routinely occurred while growth was seldom obtained on subculture from sucrose L-media. Reversion to the gonococcal parent occurred (1) on transfer of growth by the agar-block technique to similar media without penicillin or to Mueller Hinton blood agar, (2) in L-broth into which an agar block containing L-colonies was placed and time allowed for decay of penicillin, (3) on sucrose but not PVP L-media, within the original transformed L-colonies after penicillin decay. Growth in PVP L-broth was achieved. On transfer from broth culture to growth media without penicillin, reversion to the parental gonococci occurred.

scholarly journals MexXY-OprM Efflux Pump Is Required for Antagonism of Aminoglycosides by Divalent Cations inPseudomonas aeruginosa

2001 ◽  
Vol 45 (7) ◽  
pp. 2001-2007 ◽  
Author(s):  
Weimin Mao ◽  
Mark S. Warren ◽  
Angela Lee ◽  
Anita Mistry ◽  
Olga Lomovskaya
Keyword(s):  
Clinical Utility ◽  
Wild Type Strain ◽  
Efflux Pump ◽  
Divalent Cations ◽  
Therapeutic Index ◽  
Wild Type ◽  
Aminoglycoside Therapy ◽  
Mueller Hinton ◽  
Mueller Hinton Broth ◽  
Do So

ABSTRACT Antagonism of aminoglycosides by divalent cations is well documented for Pseudomonas aeruginosa and is regarded as one of the problems in aminoglycoside therapy. It is generally considered that divalent cations interfere with uptake of aminoglycosides at both the outer and inner membranes. It has been demonstrated recently that aminoglycosides can be removed from cells ofP. aeruginosa by the three-component multidrug resistance efflux pump MexXY-OprM. We sought to investigate the interplay between efflux and uptake in resistance to aminoglycosides inP. aeruginosa. To do so, we studied the effects of the divalent cations Mg2+ and Ca2+ on susceptibility to aminoglycosides in a wild-type strain of P. aeruginosa and in mutants either overexpressing or lacking the MexXY-OprM efflux pump. MICs of gentamicin, streptomycin, amikacin, apramycin, netilmicin, and arbekacin were determined in Mueller-Hinton broth in the presence of cations added at concentrations that varied from 0.125 to 8 mM. We found, unexpectedly, that while both Mg2+ and Ca2+ antagonized aminoglycosides (up to a 64-fold decrease in susceptibility at 8 mM), antagonism was seen only in the strains of P. aeruginosa that contained the functional MexXY-OprM efflux pump. Our results indicate that inhibition of the MexXY-OprM efflux pump should abolish the antagonism of aminoglycosides by divalent cations, regardless of its precise mechanism. This may significantly increase the therapeutic index of aminoglycosides and improve the clinical utility of this important class of antibiotics.

scholarly journals Recording the Presence of Peanibacillus larvae larvae Colonies on MYPGP Substrates Using a Multi-Sensor Array Based on Solid-State Gas Sensors

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4917
Author(s):  
Beata Bąk ◽  
Jakub Wilk ◽  
Piotr Artiemjew ◽  
Jerzy Wilde
Keyword(s):  
Gas Sensors ◽  
Culture Media ◽  
Laboratory Diagnosis ◽  
Baseline Correction ◽  
American Foulbrood ◽  
Sensor Signal ◽  
Sodium Pyruvate ◽  
Mueller Hinton ◽  
Regeneration Phase ◽  
Mueller Hinton Broth

American foulbrood is a dangerous disease of bee broods found worldwide, caused by the Paenibacillus larvae larvae L. bacterium. In an experiment, the possibility of detecting colonies of this bacterium on MYPGP substrates (which contains yeast extract, Mueller-Hinton broth, glucose, K2HPO4, sodium pyruvate, and agar) was tested using a prototype of a multi-sensor recorder of the MCA-8 sensor signal with a matrix of six semiconductors: TGS 823, TGS 826, TGS 832, TGS 2600, TGS 2602, and TGS 2603 from Figaro. Two twin prototypes of the MCA-8 measurement device, M1 and M2, were used in the study. Each prototype was attached to two laboratory test chambers: a wooden one and a polystyrene one. For the experiment, the strain used was P. l. larvae ATCC 9545, ERIC I. On MYPGP medium, often used for laboratory diagnosis of American foulbrood, this bacterium produces small, transparent, smooth, and shiny colonies. Gas samples from over culture media of one- and two-day-old foulbrood P. l. larvae (with no colonies visible to the naked eye) and from over culture media older than 2 days (with visible bacterial colonies) were examined. In addition, the air from empty chambers was tested. The measurement time was 20 min, including a 10-min testing exposure phase and a 10-min sensor regeneration phase. The results were analyzed in two variants: without baseline correction and with baseline correction. We tested 14 classifiers and found that a prototype of a multi-sensor recorder of the MCA-8 sensor signal was capable of detecting colonies of P. l. larvae on MYPGP substrate with a 97% efficiency and could distinguish between MYPGP substrates with 1–2 days of culture, and substrates with older cultures. The efficacy of copies of the prototypes M1 and M2 was shown to differ slightly. The weighted method with Canberra metrics (Canberra.811) and kNN with Canberra and Manhattan metrics (Canberra. 1nn and manhattan.1nn) proved to be the most effective classifiers.

scholarly journals In Vitro Activities of Daptomycin against 2,789 Clinical Isolates from 11 North American Medical Centers

2001 ◽  
Vol 45 (6) ◽  
pp. 1919-1922 ◽  
Author(s):  
Arthur L. Barry ◽  
Peter C. Fuchs ◽  
Steven D. Brown
Keyword(s):  
Clinical Isolates ◽  
In Vitro Activity ◽  
Broth Microdilution ◽  
In Vitro Susceptibility ◽  
Medical Centers ◽  
Mueller Hinton ◽  
Calcium Cations ◽  
Important Exception ◽  
Mueller Hinton Broth

ABSTRACT The in vitro activity of daptomycin is affected by the concentration of calcium cations in the test medium. Mueller-Hinton broth is currently adjusted to contain 10 to 12.5 mg of magnesium per liter and 20 to 25 mg of calcium per liter, but for testing of daptomycin, greater concentrations of calcium (50 mg/liter) are recommended to better resemble the normal concentration of ionized calcium in human serum. Two levels of calcium were used for broth microdilution tests of 2,789 recent clinical isolates of gram-positive bacterial pathogens. MICs of daptomycin were two- to fourfold lower when the broth contained additional calcium. For most species, however, the percentages of strains that were inhibited by 2.0 μg of daptomycin per ml were essentially identical with the two broth media. Enterococci were the important exception; i.e., 92% were inhibited when tested in calcium-supplemented broth but only 35% were inhibited by 2.0 μg/ml without the additional calcium. This type of information should be considered when selecting criteria for defining in vitro susceptibility to daptomycin.

Effect of Ethanol/Trisodium Citrate Lock on Microorganisms Causing Hemodialysis Catheter-Related Infections

2007 ◽  
Vol 8 (4) ◽  
pp. 262-267 ◽  
Author(s):  
T.A. Takla ◽  
S.A. Zelenitsky ◽  
L.M. Vercaigne
Keyword(s):  
In Vitro Study ◽  
Trisodium Citrate ◽  
Methicillin Resistant ◽  
Hemodialysis Catheter ◽  
E Coli ◽  
Lock Solution ◽  
Mueller Hinton ◽  
Mueller Hinton Broth ◽  
Made In

Purpose This in vitro study tested the effectiveness of a novel 30% ethanol/4% trisodium citrate (TSC) lock solution against the most common pathogens causing hemodialysis catheter-related infections. Methods Clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) (n=4), methicillin-sensitive S. aureus (MSSA) (n=8), methicillin-resistant Staphylococcus epidermidis (MRSE) (n=8), Pseudomonas aeruginosa (n=4) and Escherichia coli (n=4) were tested in duplicate. Bacterial suspensions of each isolate were made in a control solution of normal saline and Mueller-Hinton broth (MHB), and in a lock solution of ethanol 30%, TSC 4% and MHB. Suspensions were incubated at 37 °C for 48 h. Colony counts were determined from samples collected at t=0 h (before exposure to the ethanol/TSC lock), t=1 h (one hour after exposure to the ethanol/TSC lock), t=24 h and t=48 h. To confirm the absence of viable organisms in the lock solution, the remaining volume at 48 h was filtered through a 0.45 μm filter. The filter was rinsed with 15 mL sterile water and plated on tryptic soy agar (TSA). Results All controls demonstrated significant growth over 48 h. In the lock solutions, initial inocula were reduced to 0 viable colonies by t=1 h (6-log kill), and there was no growth at t=24 and 48 h. Filtering of lock solutions also showed no growth. These results were consistent among duplicates of all isolates. Conclusions The 30% ethanol/4% TSC lock solution consistently eradicated MRSA, MSSA, MRSE, P. aeruginosa and E. coli within 1 h of exposure. Experiments are currently underway to test this novel lock solution on preventing biofilm production by these pathogens.

Letter To The Editor

PEDIATRICS ◽  
1970 ◽  
Vol 46 (2) ◽  
pp. 316-316
Author(s):  
Ralph A. Franciosi
Keyword(s):  
E Coli ◽  
In Vitro Sensitivity ◽  
Letter To The Editor ◽  
Mueller Hinton ◽  
The Media ◽  
Interesting Development ◽  
Co2 Atmosphere

Thank you very much for your letter regarding my letter to the editor and for the responses from Drs. Eichenwald and Mortimer. One interesting development that could be added as an addendum to show the artificial atmosphere of in vitro sensitivity is the finding that since we stopped incubating our sensitivity plates in a CO2 atmosphere, we have noted that only 11.5% of E. coli are resistant to kanamycin and only 8% resistant to ampicillin. Our sensitivity media is Mueller-Hinton with a pH of approximately 7.4. Apparently incubatioii in a CO2 atmosphere, which decreases the pH of the media, interferes with the sensitivity of E. coli in particular to kanamycin and ampicillin.

scholarly journals Antimicrobial susceptibility pattern of Corynebacterium striatum.

1996 ◽  
Vol 40 (11) ◽  
pp. 2671-2672 ◽  
Author(s):  
L Martínez-Martínez ◽  
A Pascual ◽  
K Bernard ◽  
A I Suárez
Keyword(s):  
Antimicrobial Susceptibility ◽  
Antimicrobial Agents ◽  
Susceptibility Pattern ◽  
Beta Lactams ◽  
Antimicrobial Susceptibility Pattern ◽  
Mueller Hinton ◽  
Corynebacterium Striatum ◽  
Mueller Hinton Broth

The in vitro activities of 16 antimicrobial agents against 86 strains of Corynebacterium striatum were evaluated by microdilution using cation-adjusted Mueller-Hinton broth. MICs at which 90% of strains were inhibited were 0.06 microgram/ml for teicoplanin, 1 microgram/ml for vancomycin, 0.03 to 8 micrograms/ml for beta-lactams, 8 micrograms/ml for sparfloxacin, 16 micrograms/ml for ciprofloxacin, 16/304 micrograms/ml for co-trimoxazole (trimethoprim-sulfamethoxazole), 64 micrograms/ml for tetracycline, 128 micrograms/ml for gentamicin, and > 128 micrograms/ml for amikacin, erythromycin, and rifampin.

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