Method and apparatus for the concentration of fluid-borne pathogens

Abstract

Methods and apparatus for concentrating and recovering pathogens from a fluid other than blood are disclosed. The method includes concentrating the pathogens contained in the fluid by continuously feeding the fluid through one or more flexible chamber(s) and subjecting the chamber(s) to centrifugal forces. The concentrated pathogens may be re-suspended by shaking the chamber(s).

That which is claimed:  
     
         1 . A method for concentrating and recovering pathogens from fluid, comprising the steps of: 
 continuously feeding the fluid through a flexible centrifugation chamber,    subjecting the centrifugation chamber to centrifugal forces by rotating said chamber about a rotational axis while fluid is being fed therethrough to concentrate in said chamber pathogens contained in the fluid, and    shaking the chamber to re-suspend pathogens concentrated in the chamber.    
     
     
         2 . The method of  claim 1  which includes twisting the chamber.  
     
     
         3 . The method of  claim 1  in which the step of shaking is carried out manually.  
     
     
         4 . The method of  claim 1  in which the flexible centrifugation chamber is elongated, and fluid is introduced into the chamber at substantially one end thereof and withdrawn at substantially the other end thereof.  
     
     
         5 . The method of  claim 1  in which the flexible centrifugation chamber is elongated, and fluid is introduced into the chamber at substantially one end thereof and withdrawn at substantially the same end thereof after traversing the length of the container at least about twice.  
     
     
         6 . The method of  claim 1  in which said chamber is elongated and includes a transverse seal line dividing the chamber into at least two sub-chambers, each sub-chamber including an inlet and an outlet generally in proximity to said transverse seal line and a segment-defining seal line separating said inlet and outlet and defining first and second flow path segments for fluid passing through said subchamber.  
     
     
         7 . The method of  claim 1  in which said chamber is defined by pair of facing plastic sheets, each of which has a peripheral edge area, said sheets being sealed together along at least said peripheral area.  
     
     
         8 . The method of  claim 1  in which the fluid is water.  
     
     
         9 . A method for concentrating and recovering pathogens from fluid, comprising the steps of: 
 continuously feeding the fluid serially through a plurality of flexible centrifugation chambers,    subjecting the centrifugation chambers to centrifugal forces by rotating said chambers about a rotational axis while fluid is being fed therethrough to concentrate in said chamber pathogens contained in the fluid, and    shaking at least one of the chambers to re-suspend pathogens concentrated in the chamber.    
     
     
         10 . The method of  claim 9  including adding a sedimentation enhancing agent to the fluid after processing through a chamber.  
     
     
         11 . The method of  claim 9  in which each of the one and other containers includes a flow path through which the fluid is fed, and the flow path in said other chamber is of greater length than the flow path in said one chamber.  
     
     
         12 . The method of  claim 9  further comprising the step of sealing and storing one of the chambers.  
     
     
         13 . A method for concentrating and recovering pathogens from fluid, comprising the steps of: 
 continuously feeding the fluid through a flexible centrifugation chamber,    subjecting the centrifugation chamber to centrifugal forces by rotating said chamber about a rotational axis while fluid is being fed therethrough to concentrate in said chamber pathogens contained in the fluid, and    shaking the chamber to and fro to cause a bolus of fluid in said chamber to slosh back and forth, creating increased shear forces in said chamber and causing said chamber to flex outwardly as said bolus of fluid sloshes back and forth, to re-suspend pathogens concentrated in the chamber.    
     
     
         14 . The method of  claim 13  including removing concentrated particles from said chamber.  
     
     
         15 . The method of  claim 13  in which the fluid is thereafter fed through another chamber to concentrate pathogens therewith.  
     
     
         16 . A disposable fluid circuit for use in a centrifuge, said circuit including a plurality of flexible plastic separation chambers adapted for cooperation with a rotatable centrifuge platform, said chambers being in parallel fluid flow communication in said circuit.  
     
     
         17 . A disposable fluid circuit for use in a centrifuge for concentrating pathogens from fluid, said circuit including at least a first and second flexible plastic separation chambers adapted for cooperation with a rotatable centrifuge platform, said chambers being in series fluid flow communication in said circuit, each of said chambers having a flow path defined therein for fluid flow through the chamber, said first chamber including a flow path for removal of particles concentrated therein, and said second chamber being adapted to receive processed fluid from the first chamber and having a flow path therein to define a substantially uniform flow field.  
     
     
         18 . The fluid circuit of  claim 17  in which each chamber comprises a separate flexible plastic container.  
     
     
         19 . The fluid circuit of  claim 17  in which each chamber comprises a sub-chamber of a single integral flexible plastic container.  
     
     
         20 . A disposable fluid circuit for use in a centrifuge for concentrating pathogens from fluid, said circuit including at least a first and second flexible plastic separation chambers adapted for cooperation with a rotatable centrifuge platform, said chambers being in series fluid flow communication in said circuit, each of said chambers having a flow path defined therein for fluid flow through the chamber, said first chamber being adapted to carry out a first separation process on said fluid and said second chamber being adapted to receive processed fluid from the first chamber and to concentrate pathogens contained in such processed fluid, said fluid circuit including a source of a sedimentation enhancing agent and an agent flow path communicating between said agent source and an entry site in said fluid circuit for addition to said processed fluid.  
     
     
         21 . The disposable fluid circuit of  claim 20  in which said entry site is in a fluid flow path communicating between said first and second chambers.  
     
     
         22 . The disposable fluid circuit of  claim 20  in which said entry site is in said second chamber.