Effect of Lyophilization in Sucrose Plus Dextran and Rehydration in Thioglycollate Broth on Performance of Competitive Exclusion Cultures in Broiler Chicks

Abstract

Cecal bacteria grown under continuous-flow anaerobic conditions were lyophilized in skim milk (SM), Reagent 20 (R-20; sucrose and bovine serum albumin fraction V), or sucrose plus dextran (SDx), rehydrated in drinking water or thioglycollate-beef broth (TGB), and compared with fresh broth culture for control of Salmonella typhimurium enteric colonization in broiler chicks. All groups were challenged on Day 3 with 10(4) cfu of S. typhimurium per chick. Mean Salmonella colony-forming units in cecal contents of groups provided lyophilized cultures rehydrated in TGB were not different from those in groups provided fresh broth culture and were reduced (P < .05) compared with controls at 10 d of age. Likewise, groups treated with the cultured lyophilized in R-20 and SDx and rehydrated in TGB had fewer Salmonella than similar groups treated with culture rehydrated in water. The results of this study indicated that the culture was as effective when lyophilized in SDx as it was when lyophilized in SM or R-20; culture lyophilized in SDx, SM, or R-20 and rehydrated in TGB was more effective than when it was rehydrated in water for the reduction of Salmonella colonization in broiler chicks.

Identification, Viability, and Membrane Potential during the Cryopreservation of Autochthonous Lactic-Acid Bacteria Isolated from Artisanal Adobera Cheese from Los Altos de Jalisco

“…However, the specific growth conditions required by individual members of the LAB group represent a challenge to evaluate non-common media for the isolation, growth, and preservation of this group of microorganisms [65], which also offer easy access, storage, preparation, and handling. In this context, thioglycolate broth is a generalpurpose liquid enrichment medium based on the incorporation of sodium thioglycolate as a reducing agent to remove traces of oxygen in the medium (slightly viscous) to allow the recovery and growth of several types of microorganisms, including aerobic, facultative anaerobes, and aerotolerant and microaerophilic bacteria, like LAB [66][67][68]. Furthermore, as it is not a selective medium, it is a cheaper alternative that does not require special storage conditions and its preparation is simple and comparable to that of any other nonselective culture medium.…”

Estudo da resposta imune, da colonização e invasão por Salmonella enterica subsp enterica sorotipo Typhimurium Nalr em frangos de corte, tratados com glucano, probióticos e produtos de exclusão competitiva

“…Os mecanismos deste efeito protetor ainda não foram elucidados, porém tem sido proposto que a microbiota nativa exerça uma exclusão competitiva, diminuindo as bactérias contaminantes no trato intestinal de frangos. Parece que este mecanismo tem sido amplamente aceito (SEUNA, 1979;SOEJARDI et al, 1981;STAVRIC, 1987 Outros compostos têm sido testados, em relação à colonização cecal por Salmonella, por exemplo o efeito dos carboidratos (BAILEY et al, 1991;CORRIER et al, 1990;HOLLISTER et al, 1995;OYOFO et al,1989;; sendo que alguns deles demonstraram melhores resultados que outros, na inibição da colonização (CORRIER et al, 1994;FUKATA et al, 1999 c) exclusão competitiva (OUWENHAND et al, 1999) A competição por sítios de adesão é um dos mecanismos propostos para demonstrar a ação dos probióticos. Demonstrou-se que muitos patógenos intestinais são capazes de aderir-se à parede intestinal e colonizar, sendo este um pré-requisito à produção da doença; alguns probióticos têm sido selecionados pela sua capacidade de aderir aos tecidos e competir com as bactérias patogênicas por esse lugar.…”