Staphylococcus aureus delta hemolysin detection procedure by mass spectrometry directly from a bacterial population

摘要

Procedure for studying a sample that contains a bacterial population of Staphylococcus aureus using a mass spectrometry technique that includes the following steps: a) Put the sample in contact with a medium that allows ionization by the action of a laser beam molecules present in the sample, b) Ionize the molecules present in the sample by means of a laser beam, c) Accelerate the ionized molecules obtained through a potential difference, d) Let the ionized and accelerated molecules move freely in at least one pressure tube reduced, e) Detect at least a part of the ionized and accelerated molecules that are moving freely, to measure the time it has taken to travel at least one tube under reduced pressure and obtain a signal corresponding to the number of ionized molecules detected in a given moment, f) Calculate the relationship between mass and charge [m / z] of the detected molecules, p To obtain a signal corresponding to the number of ionized molecules that have the same relationship between mass and charge [m / z], depending on the ratio m / z of the detected molecules, g) Determine, directly or indirectly, whether between the ionized molecules obtained in stage b), there were or not ionized molecules of mass / charge [m / z] equal to 3005 ± 5 Th or equal to 3035 ± 5 Th, h) Formulate a decision conditioned by the result obtained in the stage g).