Lactobacillus reuteri is a prominent member of the LactobaciUus population in the gastrointestinal ecosystem of humans, poultry, swine, and other animals. Reuterin is a newly discovered, broad-spectrum antimicrobial substance produced by this species during fermentation of glycerol. In this report, we describe procedures for (i) producing reuterin in sufficient amounts to isolate from a fermentation mixture and (ii) isolating this substance by high-performance liquid chromatography. By using uniformly labeled [14C]glycerol, reuterin was identified as a product of glycerol fermentation associated with the production of 0-hydroxypropionic acid and trimethylene glycol.Axelsson and co-workers (L. Axelsson, T. C. Chung, W. J. Dobrogosz, and S. E. Lindgren, submitted for publication) and Chung and colleagues (T. C. Chung, L. Axelsson, S. E. Lindgren, and W. J. Dobrogosz, submitted for publication) reported the discovery of a broad-spectrum antimicrobial substance termed reuterin produced by Lactobacillus reuteri. L. reuteri resides in the gastrointestinal tract of healthy humans and animals (2, 5) and is believed to function as a symbiont in the enteric ecosystem. Synthesis of such an antimicrobial substance by an enteric resident raises a number of interesting questions and possibilities as to the role these residents may play in the health of the host. Yet little is known about L. reuteri and less about reuterin except that it is produced specifically from glycerol by anaerobic resting cells under physiological conditions of temperature and pH. Preliminary investigations indicate that it is a lowmolecular-weight, neutral, water-soluble, nonprotein material that has antibacterial, antimycotic, and antiprotozoal activity.The

Lactobacillus reuteri resides in the gastrointestinal tract of humans, swine, poultry and other animals. Resting cells of this species convert glycerol into a potent, broad-spectrum antimicrobial substance termed reuterin. Reuterin is a low molecular weight, neutral, water soluble compound, capable of inhibiting growth of species representing all bacterial genera tested thus far, including: Escherichia, Salmonella, Shigella, Proteus, Pseudomonas, Clostridium and Staphylococcus. Also affected, but to a lesser degree, are lactic acid bacteria belonging to the genera Streptococcus, Pediococcus, Leuconostoc, and Lactobacillus. In this report we describe a method to screen lactobacilli for production of unique antimicrobial substances and the discovery of reuterin.

Lacrobacillus reuteri resides in the gastrointestinal ecosystem of humans and other animals. In an earlier report we showed that this enteric species converts glycerol into reuterin-a substance with broad-spectrum antibacterial activity. In this report we show that reuterin also has antimycotic and antiprotozoal activity. A minimum inhibitory concentration (MIC) assay was developed and used to study the conditions under which reuterin is synthesised. The results show reuterin to be synthesised in vitro under pH, temperature and relative anaerobic conditions similar to those believed to exist in the regions of the gastrointestinal ecosystem inhabited by L. reuteri. It was also demonstrated that L. reuteri cells are stimulated to produce reuterin when permitted to interact directly with a variety of other microorganisms. A symbiotic relationship between L. reuteri and its host is postulated and discussed.

. The objective of this study was to determine the association between the level of exposure to Burkholderia pseudomallei and the incidence rate of melioidosis and to survey the transmission modes of B. pseudomallei in the Er-Ren River Basin. The serosurveillance of melioidosis gave seropositivity rates of 36.6%, 21.6%, and 10.9%, respectively, for residents in regions A, B, and C within the Er-Ren Basin area. Culture and PCR-based detection of B. pseudomallei from soil demonstrated that the geographical distribution of this bacterium was confined to a particular site in region B. The distribution of seropositive titers was significantly associated with the incidence rate of melioidosis (120, 68, or 36 incidence cases per 100,000 population in region A, B, or C in 2005), whereas it did not correlate with the geographical distribution of B. pseudomallei within the soil. A survey of transmission modes showed that residents with seropositivity were linked to factors such as having confronted flooding and having walked barefoot on soil, which are potential risk factors associated with exposure to B. pseudomallei. Our findings indicated that the Er-Ren River Basin in Taiwan has the potential to become a high-prevalence area for melioidosis. This is the first report that documents a high prevalence of melioidosis in an area north of latitude 20°N.

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