Evaluation of resistance to low pH and bile salts of human <i>Lactobacillus</i> spp. isolates

Fuochi, Virginia; Petronio, Giulio Petronio; Lissandrello, Edmondo; Furneri, Pio Maria

doi:10.1177/0394632015590948

Cited by 37 publications

(31 citation statements)

References 25 publications

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“…As the probiotic supplement is going to be administered orally, the bacterial constituents should be resistant to the conditions of the gastrointestinal tract (GIT). Moreover, the number of live organisms that reach the gut should be large enough to produce their beneficial effect on the host [9]. On the other hand, LAB can be reservoirs of resistance genes, which could be transferred to other bacteria and even to human pathogens [10], which is why some of their safety-related characteristics should be studied.…”

Section: Introductionmentioning

confidence: 99%

Functional Properties (Acid and Bile Tolerance) and Antibiotic Susceptibility of Lactic Acid Bacteria Isolated from Newborn Calves for the Design of a Probiotic Product

Maldonado¹,

Nader‐Macías²

2015

Int J Vet Sci Res

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Diarrhea in young calves in dairy farms is one of the main causes of economic losses, morbidity and mortality. The use of probiotic products as feed additives or complements is a novel alternative for the prevention of intestinal syndromes. In order to include beneficial bacteria in the design of a probiotic product, their functional and safety characteristics must be studied. The aim of this work is to evaluate the behavior of the strains in some "in vitro" gastrointestinal conditions such as acid stress and bile salts in the specific physiological concentration of young calves. The antibiotic susceptibility of a group of lactic acid bacteria from calves which were identified due to their beneficial properties was also studied. The strains, genetically identified and used for the resistance assays were: Lactobacillus johnsonii CRL1692, CRL1693, CRL1699, CRL1700, CRL1701 and CRL1706; L. amylovorus CRL1697; L. murinus CRL 1695 and CRL1705; L. mucosae CRL1696 and CRL1698; L. salivarius CRL1694 and CRL1702; and Enterococcus faecium CRL1703. The results of gut resistance assays showed that all the strains were resistant to pH 4 and to a bile salts concentration of less than 0.5%. However, some of them were sensitive to pH 2. The most pH-sensitive strains were found to be L. johnsonii and L. amylovorus, and enterococci. However, pre-treatment at low pH increased the growth rate of the L. salivarius strains. The minimal inhibitory concentration showed that the strains were sensitive to Tetracycline, Erythromycin, Chloramphenicol and Ampicillin, while most of them were resistant to Kanamycin. The results allowed the selection of the most adequate strains to be included in a probiotic product that can be utilized most successfully in young calves.product on which we are working is directed to newborn calves, recognized as non-ruminant up to the time when the rumen becomes functional, which means that the digestive process is developed in a different way than in young animals. In calves, gastric juices are secreted daily by the stomach, resulting in the destruction of most of the microorganisms ingested with the food. Then, resistance to the acid conditions of the stomach is one of the selection criteria applied in the selection of probiotic bacteria [11].

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Section: Introductionmentioning

confidence: 99%

Functional Properties (Acid and Bile Tolerance) and Antibiotic Susceptibility of Lactic Acid Bacteria Isolated from Newborn Calves for the Design of a Probiotic Product

Maldonado¹,

Nader‐Macías²

2015

Int J Vet Sci Res

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“…identification is a valid example of highly related bacterial species that require such approach that provides the polyphasic analysis of two distinct phylogenetic markers: the 16S rDNA gene and the tuf gene encoding for the elongation factor Tu (EF-Tu). [16][17][18]33 Seven products tested in this study showed levels of viable counts similar to or slightly higher than the label claim until 3 months to deadline. The viable bacteria, recognized in two vaginal products without indication, were acceptable.…”

Section: Discussionmentioning

confidence: 91%

“…In this scenario, the polyphasic taxonomy suggested by Vandamme et al 31 and by other authors, 17,18,32 is the better choice for bacterial identification.…”

Section: Discussionmentioning

confidence: 97%

“…In fact, tuf gene is an important molecular marker to distinguish so related taxa as L. casei group. [16][17][18] The strains of L. rhamnosus GC, L. reuteri DSM 17938, and L. plantarum P 17630 were identified as the species indicated on the label, even if genotypic techniques different from our methods were used by depositor. EFSA Panel on NDA retains L. rhamnosus GG sufficiently characterized at species level, 28 but not L. reuteri DSM 17938.…”

Section: Discussionmentioning

confidence: 99%

“…isolated were discriminated by tuf gene amplification described by Ventura et al 16 A detailed description of these procedures was recently reported by two of us. 17,18 …”

Section: Identify Confirmation At Species Level Of the Strains Of Lacmentioning

confidence: 99%

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Labeling quality and molecular characterization studies of products containing Lactobacillus spp. strains.

Blandino

Fazio

Petronio

et al. 2015

Int J Immunopathol Pharmacol

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The objective of the study was to characterize at species level by phenotypic and different molecular methods the strains of Lactobacillus spp. used as constituents of five oral and four vaginal products. Susceptibilities to representative antibiotics were evaluated. In addition, total viable counts at mid and 3 months to deadline of shelf life, in the different formulations and the presence of eventual contaminant microorganisms were investigated. In all oral products the molecular characterization at species level of the strains of Lactobacillus spp. confirmed the strains stated on the label, except for one strain cited on the label as Lactobacillus casei, that our study characterized as Lactobacillus paracasei. In oral products total viable cell content complied with content claimed on the label. In three out four vaginal products (one product claimed “bacillo di Döderlein”), molecular characterization complied with the bacterial name stated on the label. Two vaginal products reported viable counts on the label that were confirmed by our study. The other vaginal products, which did not report bacterial counts on the label, showed a similar decrease of viable counts at different dates to deadline compared to the others. From all the tested products, contaminant microorganisms and acquired resistance to representative antibiotics by the probiotic strains were not detected.

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Roles and applications of probiotic Lactobacillus strains

Zhang¹,

Lv²,

Pan

et al. 2018

Appl Microbiol Biotechnol

190

107

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Lactobacilli are recognized as probiotics on account of their health-promoting effects in the host. The aim of this review is to summarize current knowledge of the mechanisms of the adaption factors and main functions of lactobacilli that exert health-promoting effects in the host and to discuss important applications in animal and human health. The adaption mechanisms of lactobacilli facilitate interactions with the host and directly contribute to the beneficial nutritional, physiological, microbiological, and immunological effects in the host. Besides, the application of probiotic lactobacilli will increase our understanding of practical uses based on the roles of these organisms in immunoregulation, antipathogenic activities, and enhancement of the epithelial barrier.

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Evaluation of resistance to low pH and bile salts of human Lactobacillus spp. isolates

Cited by 37 publications

References 25 publications

Functional Properties (Acid and Bile Tolerance) and Antibiotic Susceptibility of Lactic Acid Bacteria Isolated from Newborn Calves for the Design of a Probiotic Product

Functional Properties (Acid and Bile Tolerance) and Antibiotic Susceptibility of Lactic Acid Bacteria Isolated from Newborn Calves for the Design of a Probiotic Product

Labeling quality and molecular characterization studies of products containing Lactobacillus spp. strains.

Roles and applications of probiotic Lactobacillus strains

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