EFFECT OF ENTEROCINS CCM4231 AND V24 ON THE CELLS OF ENVIRONMENTAL ISOLATES Acinetobacter spp.

Laukova A. : Effect of Enterocins CCM4231 and V24 on the Cells of Environmental Isolates Acinetobacter spp. Acta Vet. Brno 2001, 70: 473-477. The inhibitory effect of bacteriocins (enterocins) produced by different enterococcal isolates against Acinetobacter spp. strains AL1 and AL115 and/or on the resting cells of AL1 strain was tested under in vitro conditions. These poly-resistant strains (resistant to 6 from 12 antibiotics) were isolated from the cattle dung water and feces from chamois. Their growth was inhibited by treatment of crude extracts of enterocins CCM4231, V24, EC24, EK13 with activity ranged from 100 to 1600 Arbitrary units per ml. When log phase cells of Acinetobacter spp. AL1 strain were treated by crude extracts (CE) CCM4231 and V24 at temperatures 4 °C and 33 °C, the decrease of surviving cells in comparison to the control, one order of magnitude was found. In contrary, when exponential phase cells were harvested and treated by CE CCM4231 and V24, at 4 °C no reduction was noted. While at 33 °C the decrease of cells 2 orders and one order of magnitude was measured. Here, the effect of some enterocins against Gram-negative bacteria was confirmed as well as the way for further experiments to apply enterocins for the control and/or for maintaining the microbial balance in waste ecosystem. Bacteriocins, excrements, Acinetobacter spp. , anti-microbial effect Livestock management is associated with liquid and solid manure production. The manure possesses a fertilizing value that should be used as much as possible to replace expensive chemical fertilizers. However, the excessive utilization of animal manures in agriculture has resulted, in some areas of Europe with dense animal populations, in serious environmental pollution (Strauch and Ballarini 1994). That is, the manure is a source of different Grampositive and Gram-negative microorganisms, the pathogenic species including (Laukova et al. 2000a). Animal as well as public health hazard is faced in front of possibilities of diseases transmission. Genus Acinetobacter involves Gram-negative, oxidase-negative, nonmotile rods taxonomically allotted to the Family Moraxellaceae which are ubiquitously distributed in the environment (Bifulco et al. 1989; Rossau et al. 1991). They were detected even in the activated sludge (Rosset t i et al. 1997). Bergogne-Berezin (1995) presented the increasing significance of outbreaks of Acinetobacter spp. Therefore, there are the impacts leading to search for methods that would be more effective against surviving contaminants. In this paper, the effect of bacteriocins (enterocins) produced by ruminal and environmental enterococci is reported. Moreover, the effect of enterocins CCM4231 and V24 produced by Enterococcus faecium CCM4231 and Ent. faecalis V24 strains on resting cells of Acinetobacter spp. AL1 strain is included. The aim of this study resulted from our previous studies using CCM4231 and V24 bacteriocins to reduce contaminant bacteria in cattle dung water or slurry (Laukova et al. 1998; Laukova et al. 2000b). Materials and Methods Strains , media and growth condi t ions The strains of Acinetobacter spp. were isolated from cattle dung water as well as from feces of chamois by standard microbiological dilution method. Selected isolates were maintained on Trypticase soy broth and agar ACTA VET. BRNO 2001, 70: 473–477 Address for correspondence: MVDr. Andrea Laukova, PhD Institute of Animal Physiology ·oltesovej 4-6 04 001 Ko‰ice, Slovak Republic Phone: +421/55/6330283 Fax: +421/55/6782162 E-mail: laukova@saske.sk http://www.vfu. cz/acta-vet/actavet.htm