The Lactobacillus plantarum strain ACA-DC287 isolated from a Greek cheese demonstrates antagonistic activity in vitro and in vivo against Salmonella enterica serovar Typhimurium

AIMS: The purpose of this study was to investigate the antibacterial activity of the Xynotyri cheese isolate Lactobacillus plantarum ACA-DC287 using a set of in vitro and in vivo assays. METHODS AND RESULTS: The co-culture of L. plantarum strain ACA-DC287 and Salmonella enterica serovar Typhimurium strain SL1344 results in the killing of the pathogen. The killing activity was produced mainly by non-lactic acid molecule(s) that were present in the cell-free culture supernatant of the L. plantarum strain ACA-DC287. The culture of the L. plantarum strain ACA-DC287 inhibited the penetration of S. typhimurium SL1344 into cultured human enterocyte-like Caco-2/TC7 cells. In conventional mice infected with S. typhimurium SL1344, the intake of L. plantarum strain ACA-DC287 results in a decrease in the levels of Salmonella associated with intestinal tissues or those present in the intestinal contents. In germ-free mice, the L. plantarum strain ACA-DC287 colonized the gastrointestinal tract. CONCLUSIONS: The L. plantarum strain ACA-DC287 strain exerts anti-Salmonella activity similar that of the established probiotic strains Lactobacillus rhamnosus GG, Lactobacillus casei Shirota YIT9029 and Lactobacillus johnsonii La1. SIGNIFICANCE AND IMPACT OF THE STUDY: The observation that a selected cheese Lactobacillus strain exerted antibacterial activity that was similar to those of probiotic Lactobacillus strains, is of interest for the use of this strain as an adjunct strain for the production of health-giving cheeses.     

体外拮抗幽门螺杆菌的人嗜酸乳杆菌菌株的选育

目的 探讨人嗜酸乳杆菌对幽门螺杆菌（Ｈｅｌｉｃｏｂａｃｔｅｒ ｐｙｌｏｒｉ,ＨＰ）毒力株的体外拮抗作用,筛选出对ＨＰ毒力株有明显拮抗作用的嗜酸乳杆菌菌株。方法 从健康人胃肠道中分离出５２株嗜酸乳杆菌可疑株,通过其培养特性,生理特性,生化反应及代谢产物测定等进行鉴定,获得２６株嗜酸乳杆菌。同时,从临床患者胃活检标本中分离出２３株ＨＰ菌株,用ＰＣＲ方法筛选出ｃａｇＡ阳性ＨＰ毒力株,然后,采用打孔法进行嗜酸乳杆菌培养上清拮抗ＨＰ毒力株的实验,以１％的乳酸作对照。结果 筛选出４株对ＨＰ毒力株有明显拮抗作用的嗜酸乳杆菌,这种拮抗作用不依赖嗜酸乳杆菌分泌的乳酸。结论 人嗜酸乳杆菌在体外对ＨＰ毒力株具有明显拮抗作用。该研究为应用微生态疗法治疗ＨＰ感染提供了理论基础。     

Comparison of growth-phase-dependent cytosolic proteomes of two Lactobacillus plantarum strains used in food and feed fermentations

Lactobacillus plantarum is a facultative heterofermentative lactic acid bacterium highly adapted to a wide variety of environments and widely used in food and feed fermentations. Proteomes of two strains of L. plantarum, one isolated from spontaneously fermented cereal-based feed (strain REB1), and the other from white cabbage (strain MLBPL1), were studied to elucidate the strain-specific variation and the physiological changes occurring between the growth (lag, early-exponential, late-exponential and early-stationary) phases of this bacterium when cultivated in a standard rich medium. A total of 231 protein spots were identified by LC-MS/MS. These proteins showed that strain MLBPL1 had more proteins with growth phase-dependent expression than REB1, which possesses a more constant expression profile. The proteins with growth phase-dependent expression in REB1 and MLBPL1 were mainly associated with energy metabolism (glycolysis, phosphoketolase pathway and ribose metabolism), all having preferential expression in the early-exponential phase, confirming the use of different carbohydrates simultaneously. Indication of energy production was also seen in lag and early-stationary phases.     

具有降血压功能的益生菌的筛选

体外ACE抑制活性实验表明,实验室保存的40株乳酸菌菌株中有27株具抑制ACE的活性,其中尤以L·salivariusLa5、L·salivariusLma1、L·plantarumLP529、L·plantarumLS12、L·plantarumLS31、L·helveticusZL51最为明显。按照益生菌标准对上述6株菌的耐酸、耐胆盐、抗药性、抑菌等性能进行评价,结果表明,L·plantarumLP529、L·plantarumLS12、L·plantarumLS31、L·helveticusZL51可作为益生菌用于降血压产品。     

Construction of Lactobacillus plantarum strain with enhanced L-lysine yield

AIM: To enhance L-lysine secretion in Lactobacillus plantarum. METHODS AND RESULTS: An S-2-aminoethyl-L-cystein (AEC)-resistant mutant of L. plantarum was isolated, and it produced L-lysine at considerably higher level than the parent strain. Aspartokinase in the mutant has been desensitized to feedback inhibition by L-lysine. The nucleotide sequence analysis of thrA2 that codes for aspartokinase in the mutant predicted a substitution of glutamine to histidine at position 421. L-Lysine-insensitive aspartokinase, together with aspartate semialdehyde dehydrogenase, dihydrodipicolinate synthase, and dihydrodipicolinate reductase genes, was cloned from L. plantarum DNA to a shuttle vector, pRN14, and the genes were then transformed individually into the AEC-resistant mutant and the parent strain. The overexpression of the genes led to the increase in the activity of enzymes they encode in vitro. However, only the strain overexpressing aspartokinase or dihydrodipicolinate synthase produced more L-lysine. CONCLUSIONS: The desensitization of aspartokinase to L-lysine in L. plantarum led to the overproduction of L-lysine. The overexpression of L-lysine-insensitive aspartokinase or dihydrodipicolinate synthase enhanced L-lysine secretion in L. plantarum. SIGNIFICANCE AND IMPACT OF THE STUDY: The use of the L-lysine-overproducing strain of L. plantarum in food or feed fermentation may increase the L-lysine content of fermented products.     

Antagonistic activity of probiotic lactobacilli and bifidobacteria against entero- and uropathogens

AIM: To develop in vitro assays for comparing the antagonistic properties and anti-oxidative activity of probiotic Lactobacillus and Bifidobacterium strains against various entero- and urinary pathogens. METHODS AND RESULTS: The antagonistic activity of five probiotic lactobacilli (Lactobacillus rhamnosus GG, Lactobacillus fermentum ME-3, Lactobacillus acidophilus La5, Lactobacillus plantarum 299v and Lactobacillus paracasei 8700:2) and two bifidobacteria (Bifidobacterium lactis Bb12, Bifidobacterium longum 46) against six target pathogens was estimated using different assays (solid and liquid media, anaerobic and microaerobic cultivation) and ranked (low, intermediate and high). Bacterial fermentation products were determined by gas chromatography, and the total anti-oxidative activity of probiotics was measured using linolenic acid test. Pyelonephritic Escherichia coli was highly suppressed by GG and both bifidobacteria strains. Lactobacilli strains 8700:2, 299v and ME-3 were the most effective against Salmonella enterica ssp. enterica in microaerobic while ME-3 and both bifidobacteria expressed high activity against Shigella sonnei in anaerobic milieu. Lact. paracasei, Lact. rhamnosus and Lact. plantarum strains showed intermediate antagonistic activity against Helicobacter pylori under microaerobic conditions on solid media. The highest anti-oxidative activity was characteristic for Lact. fermentum ME-3 (P < 0.05). No efficient antagonist against Clostridium difficile was found. The positive correlations between the pH, lactic acid production and anti-microbial activity for all tested probiotics were assessed. CONCLUSIONS: Developed experimental assays enable to compare the anti-microbial and -oxidative activity of Lactobacillus and/or Bifidobacterium probiotics, which have been claimed to possess the ability of suppressing the growth of various enteric and urinary pathogens. SIGNIFICANCE AND IMPACT OF THE STUDY: Screening Lactobacillus and Bifidobacterium sp. strains according to their activity in various environmental conditions could precede the clinical efficacy studies for adjunct treatment with probiotics in cure of different gastrointestinal and urinary tract infections.     

Production of phenyllactic acid by lactic acid bacteria: an approach to the selection of strains contributing to food quality and preservation

The ability of lactic acid bacteria (LAB) to produce phenyllactic (PLA) and 4-hydroxy-phenyllactic (OH-PLA) acids, metabolites involved in food quality and preservation, has been evaluated by HPLC analysis in 29 LAB strains belonging to 12 species widely used in the production of fermented foods. Metabolite production was demonstrated for all strains of the species Lactobacillus plantarum, Lactobacillus alimentarius, Lactobacillus rhamnosus, Lactobacillus sanfranciscensis, Lactobacillus hilgardii, Leuconostoc citreum, and for some strains of Lactobacillus brevis, Lactobacillus acidophilus and Leuconostoc mesenteroides subsp. mesenteroides. Strains were distinguished by analysis of variance in three groups including 15 strains that produced both metabolites (0.16-0.46 mM PLA and 0.07-0.29 mM OH-PLA), five strains accumulating in culture only PLA (0.17-0.57 mM) and nine non-producer strains (< or = 0.10 mM PLA and < or = 0.02 mM OH-PLA). Improvement of phenyllactic acid production was obtained in a selected L. plantarum strain by increasing the concentration of phenylalanine in culture and using low amounts of tyrosine.     

Characterization of lactobacilli isolated from caper berry fermentations

AIMS: To determine the metabolic and functional properties of lactobacilli isolated from caper fermentation. METHODS AND RESULTS: A collection of 58 lactobacilli from fermentation of caper berries (including species of Lactobacillus plantarum, Lactobacillus paraplantarum, Lactobacillus pentosus, Lactobacillus brevis and Lactobacillus fermentum) was studied. Strains were classified in different clusters according to sugar fermentation patterns. Most strains of L. plantarum (the predominant species in the fermentation) clustered in a single group. Analysis of enzymatic activities revealed a high incidence of leucine aminopeptidase, acid phosphatase, beta-galactosidase and beta-glucosidase among the different strains of lactobacilli. A high number of strains were able to degrade raffinose and stachyose. Phytase activity and bile salt hydrolase activity were only detected in certain strains of L. plantarum. CONCLUSIONS: Lactobacilli from caper fermentation are metabolically diverse, and some strains display functional properties of interest. SIGNIFICANCE AND IMPACT OF THE STUDY: Strains of lactobacilli with selected functional properties could be good candidates for future development of commercial starters for industrial caper fermentation.     

Antifungal activities of two Lactobacillus plantarum strains against Fusarium moulds in vitro and in malting of barley

AIMS: The Lactobacillus plantarum strains VTT E-78076 (E76) and VTT E-79098 (E98) were studied for their antifungal potential against Fusarium species. METHODS AND RESULTS: In vitro screening with automated turbidometry as well as direct and indirect impedimetric methods clearly showed Lact. plantarum cell-free extracts to be effective against Fusarium species including Fusarium avenaceum, F. culmorum, F. graminearum and F.oxysporum. However, great variation in growth inhibition was observed between different Fusarium species and even between strains. The antifungal potential of Lact. plantarum E76 culture, including cells and spent medium, was also examined in laboratory-scale malting with naturally contaminated two-rowed barley from the crops of 1990-96. The growth of the indigenous Fusarium flora was restricted by the addition of Lact. plantarum E76 to the steeping water. However, the antifungal effect was greatly dependent on the contamination level and the fungal species/strains present on barley in different years. CONCLUSIONS: Lactobacillus plantarum strains E76 and E98 had a fungistatic effect against different plant pathogenic, toxigenic and gushing-active Fusarium fungi. SIGNIFICANCE AND IMPACT OF THE STUDY: The present study indicates that Lact. plantarum strains with known and selected characteristics could be used as a natural, food-grade biocontrol agent for management of problems caused by Fusarium fungi during germination of cereals.     

Influence of selected Lactobacillus sp. on Clostridium difficile strains with different toxigenicity profile

This study was performed for determination of antagonistic activity of Lactobacillus spp. (L. plantarum 2017405, L. rhamnosus GG, L. acidophilus DSM 21007 and L. fernmentumn 353) on Clostridiunl difficile strains belonging to different toxigenicity profiles. Forty strains C. difficile isolated from patients suffering from antibiotic associated diarrhea (AAD) were used. Among C. difficile strains 13 produced toxin A and B (A+B+CDT-), 14 produced only toxin B (AB'CDT), 9 produced toxins A and B and possessing of binary toxin genes (A+B+CDT-) and 4 were non-toxigenic (A-B-CDT-). We did not observe relationship between degree of antagonistic activity Lactobacillus spp. and profile of toxigenicity of C. difficile strains.     

Characterization of Lactobacillus plantarum from wine must by PCR species-specific and RAPD-PCR

AIMS: Physiological and molecular analysis such as PCR species-specific and randomly amplified polymorphic PCR (RAPD-PCR) have been used for typing of Lactobacillus plantarum strains from typical wine must. METHODS AND RESULTS: Phenotypic tests such as API 50CH and evaluation of D-L-lactate production from glucose were used to perform a preliminary characterization of lactobacilli. Furthermore, 18 strains of lactobacilli were analyzed by PCR species-specific oligonucleotides based on short sequences of the recA gene. CONCLUSIONS: Four strains were identified as belonging to the L. plantarum species and were further analysed by RAPD-PCR. The RAPD-PCR profiles were similar in all strains that had positive results for species-specific PCR, suggesting that the four L. plantarum strains were closely related. SIGNIFICANCE AND IMPACT OF THE STUDY: Using PCR species-specific as a preliminary screening test and then RAPD-PCR can be as considered the most reliable method of performing a rapid and correct typing of L. plantarum from wine must.     

Redox potential to discriminate among species of lactic acid bacteria

AIMS: To verify to what degree reducing capacity is a characterizing parameter of a species, and of the strains themselves within a given species, of lactic acid bacteria. METHODS AND RESULTS: Eighty-eight strains belonging to 10 species of lactic acid bacteria (LAB) isolated from traditional Italian cheeses were studied for their reduction activity: Enterococcus faecalis, Enterococcus faecium, Enterococcus durans, Streptococcus thermophilus, Lactococcus lactis ssp. lactis, Lactobacillus paracasei ssp. paracasei, Lactobacillus plantarum, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus helveticus and Pediococcus pentosaceus. It was observed that the lactococci reached minimum redox potential before the lactobacilli. The reduction rate of Enterococcus spp. and L. lactis ssp. lactis was higher than that of the streptococci and Lactobacillus spp. All the P. pentosaceus strains had poor reduction activity compared with the other species. CONCLUSIONS: The evolution of the redox potential in milk over a time span of 24 h has been found to be a parameter that characterizes a species: the different courses corresponding to the species in question are clearly evident, and interesting differences can also be noted within the same species. SIGNIFICANCE AND IMPACT OF THE STUDY: The reduction aptitude of strains might be used to select and adapt appropriate strains for use as starters for dairy products.     

Identification of lactobacilli isolated from the cloaca and vagina of laying hens and characterization for potential use as probiotics to control Salmonella Enteritidis

AIMS: To select Lactobacillus strains from laying hens for potential use as probiotic to control Salmonella Enteritidis infection. METHODS AND RESULTS: One hundred and eighty-six lactobacilli were isolated from the cloaca and vagina of laying hens, and identified at the species level by a polyphasic taxonomic approach. All isolates belonged to the Lactobacillus acidophilus, Lactobacillus reuteri or Lactobacillus salivarius phylogenetic groups, with the L. reuteri group being the most predominant group. Based on genetic diversity, about 50 representative strains were selected and tested for in vitro properties that could be predictive for probiotic activity in laying hens. Salmonella inhibition was shown to be species dependent, and correlated to some extent with the production of lactic acid. A selection of strains was evaluated in a S. Enteritidis challenge experiment. Two strains, L. reuteri R-17485 and Lactobacillus johnsonii R-17504 significantly decreased the colonization of chicks by S. Enteritidis in caeca, liver and spleen. CONCLUSIONS: Lactobacilli isolated from laying hens were observed to inhibit Salmonella growth in vitro, most probably through production of lactic acid, and to decrease in vivo the S. Enteritidis colonization of chicks. SIGNIFICANCE AND IMPACT OF THE STUDY: The data demonstrate that Lactobacillus isolates from laying hens may have probiotic potential in reducing S. Enteritidis infection.     

潜在多重耐药患者肠道内乳杆菌的分离与鉴定

目的从临床潜在多重耐药患者粪便中分离获得乳杆菌,完成种属鉴定并分析其临床意义。方法采集临床患者粪便,在MRS和含碳酸钙的LBS固体培养基上分离培养,挑取目的菌落反复分离获得纯化菌株,利用生化鉴定方法进行种属鉴定。结果 45份样本共得到7株乳杆菌,其中植物乳杆菌5株、鼠李糖乳杆菌2株。结论研究发现,分离到的植物乳杆菌和鼠李糖乳杆菌可能具有更强的耐受性与生物学活性。分离获得的植物乳杆菌和鼠李糖乳杆菌有待日后对其开展特性、耐受性及安全性等研究,以便对分离的菌株有更深入的认识。     

1株产细菌素乳酸菌的筛选和鉴定

目的 从植物性材料中筛选产细菌素的乳酸菌。方法 琼脂扩散法。结果 所筛选的产细菌素R260菌株经鉴定为植物乳杆菌。排除有机酸、过氧化氢等干扰因素后,发酵液仍有很强的抑菌作用;用胰蛋白酶和胃蛋白酶处理后,发酵液抑菌活性急剧下降,因而确定产生的抑菌物质具有蛋白质性质,是一种细菌素。抑菌谱试验测定表明,此菌株的发酵液不仅抑制革兰阳性菌,而且对部分革兰阴性菌也有抑制作用,因此产生的是一类广谱细菌素。结论筛选到了1株产广谱细菌素的乳酸菌。     

Antagonistic activity against pathogenic bacteria by human vaginal lactobacilli

This study attempted to isolate lactobacilli strains from healthy vaginal ecosystem to search for a new effective antibacterial probiotic strain. The strains were identified and characterized for their probiotic properties including bile salt and acid tolerance, growth at acidic pH, their ability to utilize protein, starch, and lipid, the production of hydrogen peroxide and bacteriocin as well as their antibiotic resistance patterns. The antibacterial activity of the culture supernatant of these strains were tested against a wide range of Gram-positive and Gram-negative pathogenic bacteria including Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae. Salmonella typhi, and Salmonella typhimurium. None of the strains inhibited the growth of Gram-negative bacteria. Contrastly, the culture supernatant of strain L 22, identified as Lactobacillus reuteri, significantly inhibited all of the clinical isolates of methicillin-resistant S. aureus (MRSA). The antibacterial effect of the selected strain L 22 was further investigated. In the presence of L 22, the bacterial growth was assessed in vitro by viable bacterial counting. The numbers of viable cells were significantly lower in L 22-containing broth than those in the control by 6h. This finding clearly demonstrates that strain L 22 can produce an anti-MRSA effect. The antibacterial ability of the strain L 22 was fundamentally attributed to their bacteriocin production which can cause both cell inhibition and cell death.     

Characterization and selection of vaginal Lactobacillus strains for the preparation of vaginal tablets

AIMS: To characterize and select Lactobacillus strains for properties that would make them a good alternative to the use of antibiotics to treat human vaginal infections. METHODS AND RESULTS: Ten Lactobacillus strains belonging to four different Lactobacillus species were analysed for properties relating to mucosal colonization or microbial antagonism (adhesion to human epithelial cells, hydrogen peroxide production, antimicrobial activity towards Gardnerella vaginalis and Candida albicans and coaggregation with pathogens). The involvement of electrostatic interactions and the influence of bacterial metabolic state in the binding of lactobacilli to the cell surface were also studied. Adherence to epithelial cells varied greatly among the Lactobacillus species and among different strains belonging to the same Lactobacillus species. The reduction in surface negative electric charge promoted the binding of several Lactobacillus strains to the cell membrane whereas lyophilization reduced the adhesion capacity of many isolates. The antimicrobial activity of lactobacilli culture supernatant fluids was not directly related to the production of H2O2. CONCLUSIONS: Three strains (Lactobacillus brevis CD2, Lact. salivarius FV2 and Lact. gasseri MB335) showed optimal properties and were, therefore, selected for the preparation of vaginal tablets. The selected strains adhered to epithelial cells displacing vaginal pathogens; they produced high levels of H2O2, coaggregated with pathogens and inhibited the growth of G. vaginalis. SIGNIFICANCE AND IMPACT OF THE STUDY: The dosage formulation developed in this study appears to be a good candidate for the probiotic prophylaxis and treatment of human vaginal infections.     

Quantitative evaluation of adhesion of lactobacilli isolated from human intestinal tissues to human colonic mucin using surface plasmon resonance (BIACORE assay)

AIMS: To isolate lactobacilli from the mucus layer of the human intestine and evaluate their adhesion abilities using a BIACORE assay. METHODS AND RESULTS: Thirty strains of lactobacilli were isolated from the mucus layer of normal human intestinal tissues using conventional plate culture. The strains were identified using homology comparisons of the 16S rDNA sequence to databases as Lactobacillus salivarius (26%), Lactobacillus fermentum (13%), Lactobacillus gasseri (10%), Lactobacillus paracasei (7%), Lactobacillus casei (3%), Lactobacillus mucosae (3%) and Lactobacillus plantarum (3%). Lactobacillus plantarum LA 318 shows the highest adhesion to human colonic mucin (HCM) using the BIACORE assay at 115.30 +/- 12.37 resonance unit (RU). The adhesion of cell wall surface proteins from strain LA 318 was significantly higher to HCM than to bovine serum albumin (BSA; P < 0.05). CONCLUSIONS: We isolated 30 strains of lactobacilli. Lactobacillus salivarius was the predominant species of lactobacilli isolated in this study. The adhesion of strain LA 318 isolated from human transverse colon to its mucin was shown. The adhesion could be mediated by lectin-like components on the bacterial cell surface. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study where lactobacilli were isolated from human intestinal tissues and shown to adhere to HCM.     

Inhibition of adhesion of food-borne pathogens to Caco-2 cells by Lactobacillus strains

AIMS: To select adhesive strains among strains of Lactobacillus and to apply them to inhibit adhesion of food-borne pathogens. METHODS AND RESULTS: Twelve Lactobacillus strains (10 from intestine) were examined for adhesion using Caco-2 cell cultures. The two most adhesive strains, Lactobacillus crispatus JCM 8779 and Lact. reuteri JCM 1081, were used to test antiadhesion activity against enterotoxigenic Escherichia coli, Salmonella typhimurium and Enterococcus faecalis strains. Adhesion of the pathogens was inhibited by both Lactobacillus strains. Adhesion of Ent. faecalis was especially strongly inhibited by JCM 8779. Although antimicrobial activity was not detected in the culture supernatant fluid by agar well diffusion assay, the supernatant fluid obtained from the harvested JCM 8779 cell suspension showed bactericidal activity against Ent. faecalis. CONCLUSION: The strong antiadhesion activity of JCM 8779 against Ent. faecalis appears to be due to the combined effect of both bactericidal activity and competition for attachment site. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report that Lact. crispatus produces a bactericidal substance.     

Characterization and Transfer of Antibiotic Resistance in Lactic Acid Bacteria from Fermented Food Products

The study provides phenotypic and molecular analyses of the antibiotic resistance in lactic acid bacteria (LAB) from fermented foods in Xi'an, China. LAB strains (n = 84) belonging to 16 species of Lactobacillus (n = 73), and Streptococcus thermophilus (n = 11) were isolated and identified by sequencing their 16S rRNA gene. All strains were susceptible to ampicillin, bacitracin, and cefsulodin, and intrinsically resistant to nalidixic acid, kanamycin, and vancomycin (except L. bulgaricus, L. acidophilus, and S. thermophilus, which were susceptible to vancomycin). Some strains had acquired resistance for penicillin (n = 2), erythromycin (n = 9), clindamycin (n = 5), and tetracycline (n = 14), while resistance to gentamycin, ciprofloxacin, streptomycin, and chloramphenicol was species dependent. Minimum inhibitory concentrations presented in this study will help to review microbiological breakpoints for some of the species of Lactobacillus. The erm(B) gene was detected from two strains of each of L. fermentum and L. vaginalis, and one strain of each of L. plantarum, L. salivarius, L. acidophilus, L. animalis, and S. thermophilus. The tet genes were identified from 12 strains of lactobacilli from traditional foods. This is the first time, the authors identified tet(S) gene from L. brevis and L. kefiri. The erm(B) gene from L. fermentum NWL24 and L. salivarius NWL33, and tet(M) gene from L. plantarum NWL22 and L. brevis NWL59 were successfully transferred to Enterococcus faecalis 181 by filter mating. It was concluded that acquired antibiotic resistance is well dispersed in fermented food products in Xi'an, China and its transferability to other genera should be monitored closely.