scholarly journals A simple carbohydrate fermentation test for identification of the pathogenic Neisseria

1975 ◽  
Vol 2 (1) ◽  
pp. 72-73
Author(s):  
A Reddick
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Mueller Hinton ◽  
Paper Disk ◽  
Carbohydrate Fermentation ◽  
Fermentation Test ◽  
Agar Method ◽  
Disk Method ◽  
Mueller Hinton Broth ◽  
Simple Carbohydrate

The carbohydrate fermentation test in cystine-Trypticase agar-tubed medium was compared with the Minitek system with carbohydrate-impregnated paper disks in Müeller-Hinton broth for identification of Neisseria gonorrhoeae and N. meningitidis. There was 100% agreement between the methods for confirmation of N. meningitidis. The paper disk method confirmed 98% of the N. gonorrhoeae isolates; the cystine-Trypticase agar method confirmed 96%. Reactions with the paper disk method could be read in 4 h.

scholarly journals Simple disk-plate method for the biochemical confirmation of pathogenic Neisseria

1976 ◽  
Vol 3 (2) ◽  
pp. 172-174
Author(s):  
J A Valu
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Clinical Isolates ◽  
Limited Sample ◽  
Plate Method ◽  
Simple Method ◽  
Carbohydrate Fermentation ◽  
Fermentation Test

The carbohydrate fermentation test in cystine trypticase agar (BBL)-tubed medium was compared with a simple method using commercially available carbohydrate impregnated disks on culture inoculated Thayer-Martin medium with and without (vancomycin, colistimethate, and nystatin) inhibitors. There was 100% agreement between the two methods when a limited sample of clinical isolates of Neisseria gonorrhoeae and Nesseria meningitidis were tested.

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.

scholarly journals Extending Postharvest Longevity and Improving Quality of Strawberry (Fragaria Ananasa Duch Cv. ‘Gaviota’) Fruit by Postharvest Salicylic Acid Treatment

2015 ◽  
Vol 3 (2) ◽  
pp. 17 ◽  
Author(s):  
Mahsa Geransayeh ◽  
Sadegh Sepahvand ◽  
Vahid Abdossi
Keyword(s):  
Weight Loss ◽  
Salicylic Acid ◽  
Vitamin C ◽  
Horticultural Crops ◽  
Postharvest Application ◽  
Spray Method ◽  
Paper Disk ◽  
Fruit Decay ◽  
Activity Decay ◽  
Disk Method

Strawberries are an extremely perishable fruit mainly due to their soft texture and sensitivity to fungal infection. Postharvest application of conventional fungicides to fruits is prohibited. As an alternative to fungicides, salicylic acid has been found to enhance disease resistance of horticultural crops. In order to study the effect of salicylic acid as a phenolic compound on the postharvest durability and quality characteristics of strawberry fruit. ‘Gaviota’ strawberries were treated with SA at different concentrations (0, 25, 50 and 100 µlL-1), then stored for 12 days at 4 ˚C and 75 % RH in darkness. Two different methods were applied (spray SA on fruits and paper disk method). Quality attributes such as weight loss, pH, TA, TSS, vitamin C, anthocyanin, calcium, pectin, CAT, POD, PG activity, decay percentage and sensory analyses evaluated every 3 days during storage. Results showed that, treated fruits with SA had lower weight loss, pH, TSS, POD, PG, decay and higher TA, vitamin C, anthocyanin, calcium, pectin, CAT and fruit quality compared with controls. Between two methods of treatment, paper disk method had higher effect on fruit decay and quality compared to spray method and as a general result, caused longer storability.

Comparison of three methods for identification of pathogenic Neisseria species

1979 ◽  
Vol 9 (5) ◽  
pp. 598-600
Author(s):  
P C Appelbaum ◽  
R B Lawrence
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Neisseria Meningitidis ◽  
Incubation Period ◽  
Fluorescent Antibody ◽  
Neisseria Species ◽  
Neisseria Lactamica ◽  
Sugar Degradation ◽  
Agar Method ◽  
Neisseria Sicca

A radiometric procedure was compared with the Minitek and Cystine Trypticase Agar sugar degradation methods for identification of 113 Neisseria species (58 Neisseria meningitidis, 51 Neisseria gonorrhoeae, 2 Neisseria lactamica, 2 Neisseria sicca). Identification of meningococci and gonococci was confirmed by agglutination and fluorescent antibody techniques, respectively. The Minitek method identified 97% of meningococci, 92% of gonococci, and 100% of other Neisseria after 4 h of incubation. The radiometric (Bactec) procedure identified 100% of gonococci and 100% of miscellaneous Neisseria after 3 h, but problems were encountered with meningococci: 45% of the later strains yielded index values for fructose between 20 and 28 (recommended negative cut-off point, less than 20), with strongly positive (greater than 100) glucose and maltose and negative o-nitrophenyl-beta-D-galactopyranoside reactions in all 58 strains. The Cystine Trypticase Agar method identified 91% of meningococci, 90% of gonococci, and 100% of other Neisseria after 24 to 48 h. Prolongation of the Cystine Trypticase Agar incubation period led to abnormal lactose/sucrose reactions in some meningococci and gonococci. Radiometric and Minitek systems are more accurate and convenient than Cystine Trypticase Agar techniques, but, on the basis of these results, radiometric fructose sensitivity levels for meningococci need reevaluation.

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.

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