Lactic pathogen

Sepsis The systemic inflammatory response syndrome and documented infection (culture or Gram stain of blood, sputum, urine, or normally sterile body fluid positive for pathogenic microorganisms Severe sepsis Sepsis associated with organ dysfunction, hypoperfusion, or hypotension (systolic blood pressure less than 90 mm Hg). Hypoperfusion and perfusion abnormalities may include, but are not limited to, lactic acidosis, oliguria, or acute alteration in mental status. 

Vescovo, M., Torriani, S., Orsi, C., Macchiarolo, F. and Scolari, G. (1996) Application of antimicrobial-producing lactic acid bacteria to control pathogens in ready-to-use vegetables . Journal of Applied Bacteriology, 81, 113-119. 

Wilderdyke, M.R., Smith, D.A. and Brashears, M.M. (2004) Isolation, identification, and selection of lactic acid bacteria from alfalfa sprouts for competitive inhibition of foodbome pathogens. Journal of Food Protection, 67, 947-951. 

Myopathies have been described in several sporadic cases with lactic acidosis, cytochrome oxidase (COX)-positive RRF in muscle, and isolated complex I deficiency, and have been attributed to various pathogenic mutations in ND genes. The sporadic nature of these myopathies suggests that the ND mutations are de novo, arising spontaneously in myogenic stem cells after germ-layer differentiation (somatic mutations) [14]. 

Modern methods of livestock production are intensive and the environmental conditions stress the animals. The use of antibiotics promotes growth and protects the animals from otherwise certain infection under these conditions. Antibiotic-like compounds formed in lactic acid fermentations prevent proliferation of spoilage and pathogenic microorganisms and increase the shelf life of the products. Nisin is a antimicrobial produced by a lactic acid bacterium and is used in some countries as a food preservative. Some lactic acid bacteria are capable of favorably influencing the fecal flora in man and animals. 

Table IV. Inhibition of Pathogenic Staphylococci by Lactic Cultures in Sausage...

The key feature which draws attention to these peptides in respect to food applications is their ability to inhibit undesirable organisms, either spoilage or pathogenic organisms. Although the peptides from eukaryotic sources appear far-removed from immediate application in foods, it is important to study their mechanism(s) of action in relation to those of lactic acid bacteria to better understand commonalities in structure-function Such commonalities may serve as a base from which to initiate molecular... 

Only a few types of microorganisms are able to survive and proliferate under the relatively high alcohol and low pH conditions which characterize most wines. Of these, yeast, acetic acid bacteria, and lactic acid bacteria are the most common. No pathogenic organisms are able to survive in wine. 

The mechanism(s) by which lactic acid bacteria inhibit or inactivate other bacteria is not totally clear. Daly et al. (1972), Speck (1972), and Gilliland and Speck (1972) have cited evidence which suggests that the following may be involved (1) production of antibiotics such as nisin, diplococcin, acidophilin, lactocidin, lactolin, and perhaps others (2) production of hydrogen peroxide by some lactic acid bacteria (3) depletion of nutrients by lactic acid bacteria, which makes growth of pathogens difficult or impossible (4) production of volatile acids (5) production of acid and reduction in pH (6) production of D-leucine and (7) lowering the oxidation-reduction potential of the substrate. 

Gilliland, S. E. and Speck, M. L. 1972. Interactions of food starter cultures and food-borne pathogens Lactic streptococci versus staphylococci and salmonellae. J. Milk Food Technol. 35, 307-310. 

Organic acids may exhibit other sensory properties. For example, citric acid possesses sweet-and-sour sensory notes, and succinic acid has a salty-bitter taste. On the other hand, the typical taste and flavor of Emmental cheese can be ascribed to the propionic acid and a few other compounds, such as proline. In fact, taste and flavor result from the combination of different food constituents in definite proportions. Raw meat smells much like lactic acid, which arises from postmortem anaerobic glucolysis and determines the pH of meat, its final properties, and microbial stability. This same organic acid has been related to the inhibition of certain pathogenic bacteria in yogurt (3). Table 1 lists the reported threshold concentrations for various organic acids in different media (4-6). 

The mechanisms by which probiotics (and prebiotics) produce beneficial effects on the gut have not yet been fully elucidated. However, at least three mechanisms of action have been proposed (i) antibacterial agents produced by probiotic organisms may have an inhibitory effect on pathogenic microbes (ii) immune responses may be enhanced to suppress potential pathogens and (iii) competition in the gut epithelium may allow lactic acid bacteria and bifidobacteria to supplant pathogenic organisms. 

Y4. Yasukawa, T., Suzuki, T., Ueda, T., Ohta, S., and Watanabe, K., Modification defect at anticodon wobble nucleotide of mitochondrial tRNALeu(UUR) with pathogenic mutations of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes. J. Biol. Chem. 275, 4251-4257 (2000). 

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