Detection of Clostridium tyrobutyricum spores using polyclonal antibodies and flow cytometry.
OBJECTIVE
The present work investigates the feasibility of using flow cytometry (FCM) combined with fluorescent-labelled specific polyclonal antibodies for the detection and presumptive identification of Clostridium tyrobutyricum spores in bovine milk.


RESULTS
Two fluorescent molecules (fluorescein isothiocyanate and Alexa Fluor 488) were conjugated to antispores polyclonal antibodies. Side scatter and forward scatter profiles of the Cl. tyrobutyricum spores marked with fluorescent antibodies permitted the detection of spores and differentiated them from other related microbial species. The detection limit of this method was 10(3) spores per 100 ml of milk, and results could be achieved in 2 h.


CONCLUSIONS
FCM combined with fluorochrome-conjugated antibodies, especially Alexa Fluor, could be an efficacious means to detect and provide presumptive identification of Cl. tyrobutyricum spores, as well as differentiation from other Clostridium species that can also cause late blowing in cheese.


CONCLUSIONS
This study describes the basis for the development of a method suitable for analysis of milk destined for cheese manufacture that would permit the detection of Cl. tyrobutyricum spores in a short period. This would enable the industry to use contaminated milk for dairy products other than cheese where Cl. tyrobutyricum does not cause a problem.
Lavilla
M
M
Tecnología de los Alimentos, Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain.
Marzo
I
I
de Luis
R
R
Perez
M D
MD
Calvo
M
M
Sánchez
L
L
D000818:Animals; D048014:Clostridium tyrobutyricum / Q000302:isolation & purification*; D005434:Flow Cytometry; D015200:Fluoroimmunoassay; D005516:Food Microbiology; D057230:Limit of Detection; D008892:Milk / Q000382:microbiology*; D013171:Spores, Bacterial / Q000302:isolation & purification