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 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.

scholarly journals Diagnosis of Varroosis Based on Bee Brood Samples Testing with Use of Semiconductor Gas Sensors

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 4014
Author(s):  
Beata Bąk ◽  
Jakub Wilk ◽  
Piotr Artiemjew ◽  
Jerzy Wilde ◽  
Maciej Siuda
Keyword(s):  
Gas Sensors ◽  
Cross Validation ◽  
Statistical Tests ◽  
Baseline Correction ◽  
Sensor Reading ◽  
Efficient Detection ◽  
Positive Rate ◽  
Semiconductor Gas Sensors ◽  
Regeneration Phase ◽  
Global Accuracy

Varroosis is a dangerous and difficult to diagnose disease decimating bee colonies. The studies conducted sought answers on whether the electronic nose could become an effective tool for the efficient detection of this disease by examining sealed brood samples. The prototype of a multi-sensor recorder of gaseous sensor signals with a matrix of six semiconductor gas sensors TGS 823, TGS 826, TGS 832, TGS 2600, TGS 2602, and TGS 2603 from FIGARO was tested in this area. There were 42 objects belonging to 3 classes tested: 1st class—empty chamber (13 objects), 2nd class—fragments of combs containing brood sick with varroosis (19 objects), and 3rd class—fragments of combs containing healthy sealed brood (10 objects). The examination of a single object lasted 20 min, consisting of the exposure phase (10 min) and the sensor regeneration phase (10 min). The k-th nearest neighbors algorithm (kNN)—with default settings in RSES tool—was successfully used as the basic classifier. The basis of the analysis was the sensor reading value in 270 s with baseline correction. The multi-sensor MCA-8 gas sensor signal recorder has proved to be an effective tool in distinguishing between brood suffering from varroosis and healthy brood. The five-time cross-validation 2 test (5 × CV2 test) showed a global accuracy of 0.832 and a balanced accuracy of 0.834. Positive rate of the sick brood class was 0.92. In order to check the overall effectiveness of baseline correction in the examined context, we have carried out additional series of experiments—in multiple Monte Carlo Cross Validation model—using a set of classifiers with different metrics. We have tested a few variants of the kNN method, the Naïve Bayes classifier, and the weighted voting classifier. We have verified with statistical tests the thesis that the baseline correction significantly improves the level of classification. We also confirmed that it is enough to use the TGS2603 sensor in the examined context.

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.

Amino acid metabolism of myeloma cells in culture

1976 ◽  
Vol 21 (3) ◽  
pp. 609-615
Author(s):  
R.S. Roberts ◽  
H.W. Hsu ◽  
K.D. Lin ◽  
T.J. Yang
Keyword(s):  
Amino Acids ◽  
Acid Metabolism ◽  
Culture Media ◽  
Growth Yield ◽  
Media Analysis ◽  
Sodium Pyruvate ◽  
Isoleucine Leucine ◽  
Myeloma Protein ◽  
Simple Modification ◽  
Myeloma Cells

The growth of myeloma cells in Leibovitz medium supplemented with 20% serum was limited by the depletion of glutamine. A simple modification of the Leibovitz medium by increasing the concentrations of glutamine, lysine, isoleucine, leucine, sodium pyruvate, galactose, and vitamins resulted in over 100% increase in cell growth yield. The total myeloma protein produced by the cells was increased by approximately 90% in modified Leibovitz media. Analysis of spent culture media for 19 amino acids showed that the concentrations of 8 amino acids were reduced; those of 5 amino acids were increased and the other 6 did not change significantly.

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.

scholarly journals 1588. Delafloxacin Activity Against Staphylococcus aureus with Reduced Susceptibility or Resistance to Methicillin, Vancomycin, Daptomycin, or Linezolid

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S579-S580
Author(s):  
Louis D Saravolatz ◽  
Joan Pawlak
Keyword(s):  
Antimicrobial Agents ◽  
Minimal Bactericidal Concentration ◽  
Limited Data ◽  
Methicillin Resistant ◽  
Mueller Hinton ◽  
Spectrum Activity ◽  
Resistant Strains ◽  
Gram Negative Organisms ◽  
Mueller Hinton Broth ◽  
Broad Spectrum Activity

Abstract Background Delafloxacin is a recently approved anionic fluoroquinolone antibiotic with broad-spectrum activity against Gram-positive and Gram-negative organisms. The drug has been approved for patients with acute bacterial skin and skin structure infections including those caused by methicillin-resistant S. aureus. There is limited data available against methicillin-resistant S. aureus blood isolates (MRSABI), vancomycin intermediate strains (VISA), vancomycin-resistant strains (VRSA), daptomycin non-susceptible strains (DNSSA) and linezolid-resistant S. aureus (LRSA). Methods Antimicrobial activity of delafloxacin, levofloxacin, vancomycin, daptomycin, ceftaroline, and linezolid was determined against recent (2016–2018) MRSABI (110), VRSA (15), VISA (35), DNSSA (40), and LRSA (6). Broth microdilution testing using Mueller–Hinton broth was used to determine minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) according to CLSI guidelines. FDA breakpoints were used to determine delafloxacin susceptibility, and CLSI breakpoints were used for all other antibiotics. Results Antimicrobial MIC90 expressed in mg/L and (% susceptible) None of the LRSA were susceptible to delafloxacin or levofloxacin. All strains that were susceptible to the antimicrobial agents above had an MBC that was the same as the MIC or one dilution greater except for linezolid which demonstrated an MBC that was more than eight-fold greater than the MIC. For MRSABI isolates with a levofloxacin MIC ≥ 8 mg/L (55/110) suggesting multiple mutations in the quinolone-resistant determining region, the delafloxacin MIC90 was 1 mg/L with a 36.4% susceptibility rate. Conclusion Delafloxacin demonstrates superior activity to levofloxacin against recent MRSA blood isolates, VISA, VRSA, and DNSSA. Disclosures All authors: No reported disclosures.

scholarly journals Scope and Predictive Genetic/Phenotypic Signatures of Bicarbonate (NaHCO3) Responsiveness and β-Lactam Sensitization in Methicillin-Resistant Staphylococcus aureus

2020 ◽  
Vol 64 (5) ◽  
Author(s):  
Selvi C. Ersoy ◽  
Mariam Otmishi ◽  
Vanessa T. Milan ◽  
Liang Li ◽  
Youngju Pak ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Clonal Complex ◽  
Population Analysis ◽  
Methicillin Resistant ◽  
Content Type ◽  
Mueller Hinton ◽  
Testing Medium ◽  
Mrsa Strains ◽  
Mueller Hinton Broth

ABSTRACT Addition of sodium bicarbonate (NaHCO3) to standard antimicrobial susceptibility testing medium reveals certain methicillin-resistant Staphylococcus aureus (MRSA) strains to be highly susceptible to β-lactams. We investigated the prevalence of this phenotype (NaHCO3 responsiveness) to two β-lactams among 58 clinical MRSA bloodstream isolates. Of note, ∼75% and ∼36% of isolates displayed the NaHCO3 responsiveness phenotype to cefazolin (CFZ) and oxacillin (OXA), respectively. Neither intrinsic β-lactam MICs in standard Mueller-Hinton broth (MHB) nor population analysis profiles were predictive of this phenotype. Several genotypic markers (clonal complex 8 [CC8]; agr I and spa t008) were associated with NaHCO3 responsiveness for OXA.

scholarly journals PSV-41 Antibacterial activity of ferulic acid and sodium chlorate against Escherichia coli F18 and K88 during incubations with porcine fecal bacteria

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 296-297 ◽  
Author(s):  
Claudio Arzola ◽  
Elizabeth Latham ◽  
Robin Anderson ◽  
Jaime Salinas-Chavira ◽  
Yamicela Castillo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Ferulic Acid ◽  
Sodium Chlorate ◽  
Fecal Bacteria ◽  
Aerobic Incubation ◽  
E Coli ◽  
Mueller Hinton ◽  
Fecal Suspension ◽  
Porcine Feces ◽  
Mueller Hinton Broth

Abstract The influence of ferulic acid (FA) and sodium chlorate (SC) was evaluated in two trials on the growth of Escherichia coli F18 and K88 (F18 and K88) incubated with porcine fecal bacteria. Treatments were 2 levels of FA (0 and 5 mg/mL) and 2 levels of SC (0 and 10 mM/mL). In trial one, ½-strength Mueller Hinton broth mixed with porcine feces (0.5% w/v) was inoculated with a novobiocin and naladixic acid resistant F18-strain. This fecal suspension was transferred to tubes (3/treatment) and anaerobically incubated at 39 oC for enumeration at 0, 6 and 24 h using MacConkey agar supplemented with novobiocin and naladixic acid with aerobic incubation at 37 oC. An interaction (FA x SC) at 6 and 24 h was observed (P < 0.01). At 6 h of incubation, SC alone or combined with FA had the lowest counts (P < 0.05); FA alone was lower than control but higher than SC or SC+FA (P < 0.05). At 24 h, FA alone or combined with SC had the lowest counts (P < 0.05); SC was lower than control but higher than FA or SC+FA (P < 0.05). In trial 2 were used the same procedures of trial 1, except that K88 was used. There was an interaction at 6 h (P < 0.01) where the lowest counts were in FA+SC (P < 0.05). SC alone or FA alone were lower than control but higher than SC+FA (P < 0.05). There was no interaction at 24 h (P = 0.16), where FA reduced the K88 counts (P < 0.01), however it was not affected by SC (P = 0.12). In conclusion, SC reduced E. coli counts; however, at 24 h of incubation greater reductions were observed when FA alone or combined with SC was added into the incubation fluid with porcine feces.

Sign in / Sign up

Export Citation Format

Share Document