Antibiotic resistence of the feed supplement TURVAL B0399 (probiotic with typified lactic yeast Kluyveomyces marxianus fragilisB03999).

Trial 84 The results shown in antibiogram confirm that the Kluyveromyces marxianus fragilis B0399 presents an elevated degree of resistance to the antibiotics tested.

Prof. Ann Vaughan at the University of Studies of Perugia Italy, Department of Biology and Agrodietary Biotechnologies.

RESISTANCE TO ANTIBIOTICS OF THE FEED SUPPLEMENT TURVAL B0399 (probiotic with typified lactic yeast Kluyveomyces marxianus fragilisB03999).

Generalities

No type of incompatibility results.

In particular, the strain Kluyveromyces marxianus fragilis B0399 (TURVAL B0399) was found to be compatible with the most common antibiotics utilized in the zootechnical field, as the test results shown above, demonstrate.

Purpose of the tests :

To evaluate the sensitivity of Kluyveromyces marxianusfragilis (B0399) to the action of some of the antibiotics which are more commonly utilized for therapeutic purposes in the zootechnical field or those capable of inhibiting the intestinal lactic, bacterial flora (lactic ferments) compared to the antibiotics to which yeasts are notoriously sensitive.

Materials and Method used for the tests:

Method of diffusion in agar, Minimum Inhibiting Concentration ( MIC ).

This method, as with the others, cannot precisely represent a situation in vivo, but it can show the effect of a change of concentration of the antibiotic on a population of yeast in the developing phase.

In regards to the procedure , the method NCCLS Kirby-Bauer was used, and the MIC method for the determination of the diameters of the halos of inhibition.

Several changes had to be made regarding the culture terrain ( Mueller-Hinton Agar ) and the preparation of the bacterial suspension for the inoculum, due to the particular needs of the yeast ( Kluyveromyces marxianus fragilis B0399 ) for development.

For the test on the sensitivity to antibiotics , the antibiotic discs of the Oxoid company were used.

Results and comments:

The trials, dated Dec, 12 2000, July 8 2002 and Dec. 17, 2002, are conducted by Prof. Ann Vaughan at the University of Studies of Perugia Italy, Department of Biology and Agrodietary Biotechnologies .

The results are reported below in Chart 1.

Chart 1 - Antibiogram of the strain Kluyveromyces fragilis (B0399)

(cfr. Department of Vegetation Biology of the University of Perugia, Italy.

ANTIBIOTIC	RESISTANCE/SENSITIVITY
	Resistance	Sensitivity	MIC (mg/l)
Bacitracin	R
Colistin	R
Penicillin	R
AMP(Ampicillin)	R
Oxytetracycline	R
AMX(Amoxicillin	R
GM (Gentamicin)	R
CMP (Chloramphenicol)	R
Erythromycin	R
Tetracycline	R
Clorotetracycline.HCL	R
Tartared Tilosin	R
Nalidixic Acid (Chinolons)	R
Lincomicin (Lincomicins)	R
Rifampicin (Rifamycins)	R
Quinupristin/Dalfopristin (Streptogramins)	R
Linezolid (Oxazolidinones)	R
Teicoplanin (Glycopepetides)	R

Comments.

The results shown in antibiogram Chart 1. confirm that the Kluyveromyces marxianus fragilis B0399 presents an elevated degree of resistance to the antibiotics tested.

Sensitivity is encountered only in the case of those antibiotics notorious for their effect on the sensitivity of many yeasts.

Mechanism that confers the resistance to several families of antimicrobials.

The resistance of Kluyveromyces fragilis to the antibiotic families considered in the tests is due to the different cellular organization which exists between the procariotic organisms (bacteria) and eucariotic organisms (yeasts and cells of superior organisms, man included).

Targets of the antibiotic activity are the procariotic cells: in particular, extremely peculiar structures of the cell itself -- the peptidoglicanic wall and the enzymes involved in its synthesis. Structures which don't have equals in any other cellular types.

Other target examples are the ribosomes and enzymes: the RNA polimerase, the topoisomerase ll, which even though are present in the eucariotic cells also, are different from a morphological standpoint as well as what regards the genetic sequence by which they are codified. These sequences are present on constitutive genes and are not acquired or led by plasmids or by transposable elements.

We would also like to point out that the eucariotic cells, among which yeast cells, are not involved in phagic infections (small viruses which have bacterial cells as a target and host). They are able to lead tracts of DNA from one procariotic cell to another. Often, what happens that in these "transported" genetic fragments also contain genes for antibiotic resistance which propagate within a population.

This problem, however, does not involve yeast cells, as was previously mentioned. Therefore, in conclusion, the resistance to antibiotics is natural and constitutional and not acquired.