Intra- and interlaboratory performances of two commercial antimicrobial susceptibility testing methods for bifidobacteria and nonenterococcal lactic acid bacteria.

In a small-scale harmonization study involving nine laboratories in eight European countries, the intra- and interlaboratory performances of two commercially available systems, i.e., the VetMIC microplate system and Etest, for antimicrobial susceptibility testing of nonenterococcal lactic acid bacteria (NELAB) and bifidobacteria were analyzed.

Diversity of lactic acid bacteria from modified atmosphere packaged sliced cooked meat products at sell-by date assessed by PCR-denaturing gradient gel electrophoresis.

The predominant lactic acid bacteria (LAB) microbiota associated with three types of modified atmosphere packaged (MAP) sliced cooked meat products (i.e. ham, turkey and chicken) was analyzed at sell-by date using a combination of culturing and molecular population fingerprinting.

Human vaginal Lactobacillus rhamnosus harbor mutation in 23S rRNA associated with erythromycin resistance.

Little is known about the diversity and distribution of resistance determinants in human commensal bacteria. The aim of this study was to determine the molecular mechanism responsible for high-level erythromycin resistance among five human vaginal Lactobacillus rhamnosus isolates. PCR screening for the presence of ermA, ermB and ermC methylase genes revealed no determinants responsible for detected erythromycin resistance.

Phenotypic and molecular assessment of antimicrobial resistance in Lactobacillus paracasei strains of food origin.

Antimicrobial resistance data in food-associated lactic acid bacteria (LAB) such as lactobacilli are mostly based on nonstandardized methodologies and/or have been obtained for only a limited number of strains. This susceptibility study included a diverse collection of 115 isolates mainly of food origin originally identified as Lactobacillus paracasei or Lactobacillus casei. Upon reidentification and removal of potential replicate isolates using repetitive DNA element PCR fingerprinting, 65 genotypically unique L.

Alloscardovia omnicolens gen. nov., sp. nov., from human clinical samples.

The taxonomic position of 12 isolates tentatively assigned to the genus Bifidobacterium on the basis of a limited phenotypic characterization was examined. The isolates were collected between 1978 and 2005 in Belgium, Sweden and Norway, and originated from various human clinical samples, including urine, blood, urethra, oral cavity, tonsil, and abscesses of lung and aortic valve. On the basis of band number and clustering analysis, repetitive DNA element-based PCR fingerprinting using the BOXA1R and (GTG)(5) primers indicated that the clinical isolates represented a taxon probably not belonging to the genus Bifidobacterium.

Accuracy of species identity of commercial bacterial cultures intended for probiotic or nutritional use.

Independent studies have indicated that the microbiological composition of several commercial probiotic products does not correspond to the product label information. The present study set out to investigate to what extent these problems may be due to the use of misidentified cultures at the onset of production. For this purpose, 213 cultures of lactic acid bacteria (LAB) and propionibacteria intended for probiotic or nutritional use were collected from 26 manufacturers of probiotic products, three international culture collections and one research institute.

Genetic basis of tetracycline and minocycline resistance in potentially probiotic Lactobacillus plantarum strain CCUG 43738.

The potentially probiotic strain Lactobacillus plantarum CCUG 43738, which displayed atypical phenotypic resistance to tetracycline (MIC, 512 microg/ml) and minocycline (MIC, 256 microg/ml), was found to contain a tet(S) gene located on a plasmid of approximately 14 kb. Plasmid curing with novobiocin eliminated this plasmid and restored the tetracycline-susceptible phenotype of the host strain.

Detection and characterization of tet(M) in tetracycline-resistant Listeria strains from human and food-processing origins in Belgium and France.

In the present study, three Listeria monocytogenes strains and one Listeria innocua strain out of a collection of 241 Listeria isolates from human and food-processing sources were found to display resistance to tetracycline (TC) due to the presence of the tet(M) gene. Through sequence analysis, it was shown that tet(M) genes in two of the isolates belong to sequence homology group (SHG) II, a group comprising chromosomally encoded tet(M) genes previously found in Staphylococcus aureus and in lactobacilli. The tet(M) genes of the two other L.

Molecular diversity and characterization of tetracycline-resistant Staphylococcus aureus isolates from a poultry processing plant.

DNA fingerprinting and molecular characterization showed that the tetracycline-resistant Staphylococcus aureus population of a South African poultry processing plant comprised one or possibly several tet(K)-containing endemic clones that contaminated chicken and machinery surfaces at all sampled processing stages. The tet(K) gene was transferable by filter mating to S. aureus recipient 80CR5 and was located on a pT181-like plasmid.

Prevalence and molecular characterization of tetracycline resistance in Enterococcus isolates from food.

In the present study, a collection of 187 Enterococcus food isolates mainly originating from European cheeses were studied for the phenotypic and genotypic assessment of tetracycline (TC) resistance. A total of 45 isolates (24%) encompassing the species Enterococcus faecalis (n = 33), E. durans (n = 7), E.