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Lactobacillus reuteri and Lact. rhamnosus are used as probiotics in man and animal. The aim of this study was to determine whether the glycopeptide resistance in these lactobacilli has a similar genetic basis as in enterococci. Five Lact. reuteri strains and one Lact. rhamnosus, as well as four Enterococcus control strains, were probed for the vanA gene cluster, the vanB gene and the vanC gene by PCR and Southern hybridization, and DNA/DNA hybridization. Their resistance and plasmid patterns were also investigated. All Lactobacillus strains were resistant to vancomycin but susceptible to a broad range of antibiotics. Four of the Lactobacillus strains (including the Lact. rhamnosus strain) did not harbour any plasmid and two of them contained ®ve and 6 plasmid bands respectively. None of the Lactobacillus strains possessed the vanA, vanB or vanC gene. These ®ndings indicate that the glycopeptide resistance of the Lactobacillus strains analysed is different from the enterococcal type. The study provides reassurance on the safety of the Lactobacillus strains used as probiotics with regard to their vancomycin resistance.

The food chain, especially raw minced meat, is thought to be responsible for an increase in the incidence of vancomycin-resistant enterococci (VRE) in human nosocomial infections. Therefore, 555 samples from 115 batches of minced beef and pork from a European Union-licensed meat-processing plant were screened for the occurrence of VRE. The processed meat came from 45 different slaughterhouses in Germany. Enterococci were isolated directly from Enterococcosel selective agar plates and also from Enterococcosel selective agar plates supplemented with 32 mg of vancomycin per liter. In addition, peptone broth was used in a preenrichment procedure, and samples were subsequently plated onto Enterococcosel agar containing vancomycin. To determine resistance, 209 isolates from 275 samples were tested with the glycopeptides vancomycin, teicoplanin, and avoparcin and 19 other antimicrobial substances by using a broth microdilution test. When the direct method was used, VRE were found in 3 of 555 samples (0.5%) at a concentration of 1.0 log CFU/g of minced meat. When the preenrichment procedure was used, 8% of the samples were VRE positive. Our findings indicate that there is a low incidence of VRE in minced meat in Germany. In addition, the resistance patterns of the VRE isolates obtained were different from the resistance patterns of clinical isolates. A connection between the occurrence of VRE in minced meat and nosocomial infections could not be demonstrated on the basis of our findings.

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A former subgenus of the genus Lactobacillus, "Streptobacterium," comprises a wide range of species, including the so-called "atypical streptobacteria," which includes the Lactobacillus sake-Lactobacillus curvatus group. Various identification systems and differentiation criteria for L. sake and L. curvatus have been described previously and are well established. The phenotypic diversity within these two species was the reason for comparing phenotypic variations with DNA homology data. Previously described biotypes of L. sake (Katagiri, Kitahara, and Fukami) and L. curvatus (Abo-Elnaga and Kandler) were the basis for selecting strains. Strains of all known biotypes of these species were examined to determine their biochemical reactions, their physiological growth characteristics, their total soluble protein contents as determined by a pattern analysis in which native polyacrylamide gel electrophoresis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis with colloidal Coomassie blue and silver diamine staining were used, and their levels of DNA homology as determined by DNA-DNA hybridization experiments. All of the phenotypic analyses revealed a diversity within the taxa, whereas the DNA-DNA hybridization analysis revealed that the level of genomic homogeneity within each species was relatively high. The phenotypic diversity and genomic homogeneity which we observed allowed us to describe subgroups of L. sake and L. curvatus. The descriptions of L. sake and L. curvatus are emended accordingly. These subgroups which we describe may be the basis for defining subspecies within these two species.The facultatively heterofermentative lactobacilli comprise a wide range of species, including species and subspecies of technological and clinical interest, such as Lactobacillus casei, Lactobacillus plantarum, Lactobacillus rhamnosus, and Lactobacillus paracasei subspecies. The so-called "atypical streptobacteria" (13, 18, 19, 34,44), which are significant spoilage bacteria, are of special interest and occur in naturally or artificially fermented meat. The habitats of Lactobacillus sake and Lactobacillus cuwatus are very diverse. These organisms are important in the production of fermented plant material (silage, sauerkraut, mixed pickles, etc.) and in the spoilage of plant material as well. They also occur in beverages (e.g., beer) and even in manure (14, 22). L. sake was first isolated from sake (rice wine) starter (22). Our strain collection also includes L. sake strains of human origin, a habitat not described previously for this species (Table 1). These bacteria have been called atypical streptobacteria compared with the "streptobacteria," a term used in classical and descriptive taxonomy (31) which is no longer used in genomically based taxonomy (46). The ability to grow at 2°C and pH 3.9 was recognized as a main criterion for differentiation. Table 2 shows other distinguishing characteristics that are based on morphological and physiological data (31, 36, 37 two species are well established, the phenotypic d...