Method for classifying and counting bacteria in body fluids

A method of differentiating between cell debris, white blood cells, erythroblasts, and bacteria in a body fluid sample, the method comprising:

• (a) providing an automated hematology analyzer capable of measuring multi-angle light scatter and fluorescence, the automated hematology analyzer having a triple trigger circuit including an ALL trigger, an FL3 trigger, an IAS trigger, an OR gate, and an AND gate;
• (b) configuring the triple trigger circuit to eliminate signals from cell debris and qualify signals from white blood cells, erythroblasts, and bacteria;
• (c) providing a body fluid sample;
• (d) mixing a lysing reagent with the body fluid sample to lyse red blood cells and membranes of erythroblasts;
• (e) staining erythroblast nuclei with a nuclear stain;
• (f) analyzing the body fluid sample with the automated hematology analyzer;
• (g) qualifying a bacteria signal generated by bacteria within the body fluid sample, wherein the bacteria signal is qualified based on the triple trigger circuit configuration, and wherein the qualified bacteria signal includes an ALL signal, an FL3+signal, and FL3 clusters;
• and
• (h) differentiating bacteria from cell debris, white blood cells, or erythroblasts based on a size of the ALL signal, an intensity of the FL3+signal, and a shape and a number of the FL3 clusters.

A method of detecting bacteria in a body fluid sample, using a hematology analyzer capable of measuring multi-angle light scatter and fluorescence, wherein the hematology analyzer includes a triple trigger circuit having an ALL trigger, an FL3 trigger, an IAS trigger, an OR gate, and an AND gate, the method comprising:

• measuring fluorescence and multi-angle light scatter of a signal with the hematology analyzer;
• determining whether the signal is generated by bacteria within the sample by determining whether an amplitude of the signal is below the OR gate and ALL trigger, but above the AND gate, FL3 trigger, and IAS trigger;
• and
• detecting bacteria within the sample based on a size of an ALL signal measured by the hematology analyzer, an intensity of an FL3+signal measured by the hematology analyzer, and a shape and a number of FL3 clusters measured by the hematology analyzer.