Lactic acid bacteria of foods and their current taxonomy.

Several new genera and species of gram-positive, catalase-negative cocci that can cause infections in humans have been described. Although these bacteria were isolated in the clinical laboratory, they were considered nonpathogenic culture contaminants and were not thought to be the cause of any diseases. Isolation of pure cultures of these bacteria from normally sterile sites has led to the conclusion that these bacteria can be an infrequent cause of infection. This review describes the new bacteria and the procedures useful for clinical laboratories to aid in their identification. The clinical relevance and our experience with the various genera and species are reviewed and discussed.

Identification, classification, and clinical relevance of catalase-negative, gram-positive cocci, excluding the streptococci and enterococci.

Lactic acid bacteria and human clinical infection

https://www.clinicalmicrobiologyandinfection.com/article/S1198-743X(15)00909-X/pdf

Emerging bacterial pathogens: the past and beyond

Lactic acid bacteria are Gram-positive non-sporing cocci, coccobacilli or rods, having a DNA base composition of less than 50 mol% G + C. They generally lack catalase, although pseudo-catalase was detected in cultures grown on a low sugar concentration, and they need a fermentable carbohydrate for growth. Glucose is converted mainly to lactic acid (homofermentatives), or to lactic acid, carbon dioxide, ethanol and/or acetic acid (heterofermentatives). The branches within lactic acid bacteria do not completely agree with the traditional classification schemes based on morphology and phenotypic characteristics. Lactic acid bacteria comprise the genera Aerococcus, Alloiococcus, Carnobacterium, Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Pediococcus, Streptococcus, Tetragenococcus, and Vagococcus. The genus Bifidobacterium will also be briefly considered here, although phylogenetically it belongs to the Actinomycetes subdivision of the Gram-positive eubacteria, comprising also Propionibacterium, Brevibacterium and the microbacteria. The latter taxa are only very distantly related to the genuine lactic acid bacteria.

Taxonomy of Lactic Acid Bacteria

SUMMARY: Partial 16S ribosomal ribonucleic acid sequences of five Aerococcus-like organisms originally isolated from patients with urinary tract infections were determined using reverse transcriptase in order to clarify their taxonomic position. Analysis of the sequence data revealed that the clinical isolates represent a hitherto unknown line of descent within the genus Aerococcus. A new species, Aerococcus urinae, is proposed for these isolates. The type strain is NCFB 2893.

/pdf/phylogenetic-analysis-of-some-aerococcus-like-organisms-from-5fyurppiko.pdf

Matthew D. Collins

Papers

Phylogenetic analysis of some Aerococcus-like organisms from urinary tract infections: description of Aerococcus urinae sp. nov.