[Growth of Clostridium botulinum in media with garlic (Allium sativum)]

The effect of garlic on the growth and toxin formation of Clostridium botulinum (GT) was studied in A) crude juice obtained from a pool of cloves by i) crushing, ii) pressing out and iii) filtration, and B) minced garlic (6 to 8 pieces per clove). For both, "white" and "red" garlic varieties were used. The juice (pH 5.7 to 6.0, for different batches) was activated 30 min at 37 degrees C and diluted (log 2) in PGY broth (g%: peptone (Difco) 1.0; glucose 0.5; yeast extract (Difco) 0.5; pH 7.3). A small drop from a 18 h at 37 degrees C chopped meat medium culture of a highly toxigenic autochthonous strain (110) of C. botulinum type A, was transferred to the juice dilutions, incubating anaerobically 15d at 37 degrees C. As a control of the inhibitory effect of the juice, four microorganisms were cultured 48 h at 37 degrees C in the juice dilutions (Table 1). Clove pieces were suspended to 50% (w/v) either in PGY broth or distilled water without pH adjustment. Aliquots were heated in water bath 15 min at 100 degrees C. After seeded with the A 110 strain, duplicate tubes and their controls were incubated 15 d at 37 degrees C in aerated and anaerobic conditions (Table 2). Titers of botulinum toxin were empirically estimated by the time to death of a pair of mice injected with 0.5 ml each, via IP, observed 72 h. Results are shown in tables 1 and 2. Garlic reduces (in undiluted juice, traces or 3 to 5 DL50/ml were recorded in separate experiments) but not inhibit GT.(ABSTRACT TRUNCATED AT 250 WORDS)