Analysis of microcalorimetric curves for bacterial identification

López, D.; Viñas, Marc; Lorén, J. Gaspar; Bermúdez, Jordi

doi:10.1139/m87-002

Cited by 19 publications

(19 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Strong differences in the pattern shape and peak intensity potentially allow pathogen identification (Fig. 1) as proposed in other studies [13,14].…”

Section: Resultsmentioning

confidence: 66%

“…In this context, artificial urine provides the stable environmental conditions necessary to obtain reproducible heat flow patterns and allows identification. The identification process itself (i.e., the assignation of a genus or species name to an unknown heat flow pattern) can be performed by various means including cross-correlation analysis [14], discriminant analysis [13], and support vector machines [23]. Note that all these methods focus on the pattern identification and not on parameters such as growth rate, detection time, or any other.…”

Section: Discussionmentioning

confidence: 99%

“…For example, in their paper, Lopez and colleagues could achieve identification with an accuracy of ca. 100 % using single strains only [14]. The major difficulty we have to be concerned with might be polymicrobial growth.…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Standardization of isothermal microcalorimetry in urinary tract infection detection by using artificial urine

et al. 2012

View full text Add to dashboard Cite

“…Strong differences in the pattern shape and peak intensity potentially allow pathogen identification (Fig. 1) as proposed in other studies [13,14].…”

Section: Resultsmentioning

confidence: 66%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Standardization of isothermal microcalorimetry in urinary tract infection detection by using artificial urine

et al. 2012

View full text Add to dashboard Cite

“…Moreover, all these techniques often require 48 h of incubation to obtain reliable results. Isothermal microcalorimetry is based on the detection of heat produced by active biological processes, such as bacterial metabolism and replication (15)(16)(17). In the present study, we developed a microcalorimetry-based approach to rapidly discriminate vancomycin-susceptible from -nonsusceptible phenotypes in MRSA strains.…”

mentioning

confidence: 99%

Rapid Detection of Staphylococcus aureus Strains with Reduced Susceptibility to Vancomycin by Isothermal Microcalorimetry

et al. 2014

View full text Add to dashboard Cite

7 CFU of overnight cultures into 3-ml vials of brain heart infusion broth supplemented with increasing concentrations of vancomycin, and growth-related heat production was measured at 37°C. For the reference strains, no heat production was detected in the VSSA isolates at vancomycin concentrations of >3 g/ml during the 72 h of incubation. The hVISA and VISA strains showed heat production with concentration-proportional delays of up to 6 g/ml in 48 h and up to 12 g/ml in 72 h, respectively. The VRSA strain showed heat production at concentrations up to 16 g/ml in 12 h. The testing of clinical strains indicated an excellent negative predictive value, allowing us to rule out a decreased vancomycin susceptibility phenotype in <8 h of incubation. Sequential isolates from a patient undergoing vancomycin therapy showed evolving microcalorimetric profiles up to a VISA phenotype. Microcalorimetry was able to detect strains with reduced susceptibilities to vancomycin in <8 h. The measurement of bacterial heat production might represent a simple and rapid method for the detection of reduced susceptibilities to vancomycin in MRSA strains.

show abstract

“…Although the transmembranous electrical potential (AV) is indicated as the driving force for aminoglycoside entry, quinone-deficient mutants with a normal At have a significantly lower uptake of gentamicin (9). These studies support the view that electron transport may have some specific role other than its requirement to produce cellular At.In this investigation, we have utilized the calorimetric technique to analyze the interplay between aminoglycosides and respiratory chain activity.Extensive data have been gathered on microbial growth and metabolism by using calorimet-y (4,6,7,(22)(23)(24)29).This technique has also demonstrated its usefulness in investigations of the activities of various antibacterial and antifungal drugs (3,13,21,25,26,31,32). Most of these studies, however, did not correlate different power contributions with different catabolic pathways in the bacterial cell.…”

mentioning

confidence: 99%

Suppression of tricarboxylic acid cycle in Escherichia coli exposed to sub-MICs of aminoglycosides

Cavallero

Eftimiadi

Radin

et al. 1990

Antimicrob Agents Chemother

View full text Add to dashboard Cite

The metabolic activity of Escherichia coli ATCC 25922 challenged with sub-MICs of aminoglycosides was analyzed with a batch calorimeter. High-performance and gas-liquid chromatographic techniques were utilized to evaluate the concentrations of metabolic reactants, intermediates, and end products. The data reported indicate that aminoglycosides inhibit or delay bacterial catabolism of carboxylic acids, with the following relative degrees of activity: amikacin > gentamicin > sisomicin > netilmicin > kanamycin. The decrease in total biomass production was proportional to the degree of tricarboxylic acid cycle inhibition.Since the discovery of streptomycin in 1944, the mechanism of action of aminoglycoside antibiotics has attracted considerable interest. Studies have revealed that a complex set of conditions may influence their uptake and pleiotropic effects (14,19,20).The uptake of these antibiotics was demonstrated to be dependent on different mechanisms: an initial energy-independent phase associated with ionic binding to the bacterial cell surface, followed by slow (EDPI) and fast (EDPII) energy-dependent steps. Binding of aminoglycosides to ribosomes is required for initiation of the latter phase (8,10,11,19,20,33).Electron transport through the respiratory chain has been shown to provide the energy required for the energy-dependent uptake (1, 2, [10][11][12]28). Although the transmembranous electrical potential (AV) is indicated as the driving force for aminoglycoside entry, quinone-deficient mutants with a normal At have a significantly lower uptake of gentamicin (9). These studies support the view that electron transport may have some specific role other than its requirement to produce cellular At.In this investigation, we have utilized the calorimetric technique to analyze the interplay between aminoglycosides and respiratory chain activity.Extensive data have been gathered on microbial growth and metabolism by using calorimet-y (4,6,7,(22)(23)(24)29).This technique has also demonstrated its usefulness in investigations of the activities of various antibacterial and antifungal drugs (3,13,21,25,26,31,32). Most of these studies, however, did not correlate different power contributions with different catabolic pathways in the bacterial cell. If no relationship between these two is established, measurement of power production represents merely a nonspecific parameter of bacterial viability and thus conveys no information on the antibiotic effect at the biochemical level. In this investigation, each component of the thermograms produced by Escherichia coli growing in Mueller-Hinton broth was correlated to the sequential activation of the catabolic pathways operating in the bacteria (27).Our findings indicate that aminoglycosides inhibit carboxylic acid catabolism and electron flow through the respiratory chain.* Corresponding author. MATERIALS AND METHODSBacterial strain. E. coli ATCC 25922 (Bactrol disks; Difco Laboratories, Detroit, Mich.) was utilized. Several other strains isolated from clinical specimens w...

show abstract

Analysis of microcalorimetric curves for bacterial identification

Cited by 19 publications

References 12 publications

Standardization of isothermal microcalorimetry in urinary tract infection detection by using artificial urine

Standardization of isothermal microcalorimetry in urinary tract infection detection by using artificial urine

Rapid Detection of Staphylococcus aureus Strains with Reduced Susceptibility to Vancomycin by Isothermal Microcalorimetry

Suppression of tricarboxylic acid cycle in Escherichia coli exposed to sub-MICs of aminoglycosides

Contact Info

Product

Resources

About