Gram-negative bacteria organisms

Tetracyclines are broad-spectrum antibiotics. effective against Gram-positive and Gram-negative bacteria, also against Rickettsiae (typhus fever) and certain other organisms. 

Gram-negative organisms produce ced-bound P-lactamases which reside in the periplasmic space. Thus, for gram-negative bacteria, the antibiotic must penetrate the outer ced membrane/wad before coming in contact with a P-lactamase (80,139,140). 

Endotoxins are the lipopolysaccharides (LPS) of the outer membrane of Gram-negative bacteria. They trigger inflammatory reactions in the infected organism, activate complement and cause fever or even a septic shock. They act on toll-like receptors. 

Bacterial resistance to biocides (Table 13.2) is usually considered as being of two types (a) intrinsic (innate, natural), a natural property of an organism, or (b) acquired, either by chromosomal mutation or by the acquisition of plasmids or transposons. Intrinsic resistance to biocides is usually demonstrated by Gram-negative bacteria, mycobacteria and bacterial spores whereas acquired resistance can result by mutation or, more frequently, by the acquisition of genetic elements, e.g. plasmid- (or transposon-) mediated resistance to mercury compounds. Intrinsic resistance may also be exemplified by physiological (phenotypic) adaptation, a classical example of which is biofilm production. 

As it leaves the still, distilled water is flee fixm microorganisms, and contamination occurs as a result of a fault in the cooling system, the storage vessel or the distribution system. The flora of contaminated distilled water is usually Gram-negative bacteria and since it is introduced after a sterilizahon process, it is often a pure culture. A level of organism up to 10 mH has been recorded. 

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