Streptococcus rates

Bacterial resistance to antibiotics has been recognized since the first drugs were introduced for clinical use. The sulphonamides were introduced in 1935 and approximately 10 years later 20% of clinical isolates of Neisseria gonorrhoeae had become resistant. Similar increases in sulphonamide resistance were found in streptococci, coliforms and other bacteria. Penicillin was first used in 1941, when less than 1 % of Staphylococcus aureus strains were resistant to its action. By 1947,3 8% of hospital strains had acquired resistance and currently over 90% of Staph, aureus isolates are resistant to penicillin. Increasing resistance to antibiotics is a consequence of selective pressure, but the actual incidence of resistance varies between different bacterial species. For example, ampicillin resistance inEscherichia coli, presumably under similar selective pressure as Staph, aureus with penicillin, has remained at a level of 30-40% for mai years with a slow rate of increase. Streptococcus pyogenes, another major pathogen, has remained susceptible to penicillin since its introduction, with no reports of resistance in the scientific literature. Equally, it is well recognized that certain bacteria are unaffected by specific antibiotics. In other words, these bacteria have always been antibiotic-resistant. 

Group B Streptococcus bacteriuria should be treated to reduce the rate of preterm delivery. These women should also receive antibiotics at delivery to prevent infection in the newborn. 

Worldwide Streptococcus pneumoniae % susceptibility to penicillin is decreasing. In some countries up to two-thirds of the clinical isolates have reduced susceptibility to penicillin or are highly resistant to this drug. Moreover, the rate of resistance to other drugs commonly used for RTI including erythromycin, tetracycline and trimethoprim-sulfamethoxazole is higher in penicillin-resistant than penicillin-susceptible strains. Monitoring local or hospital resistance patterns of pneumococci is, therefore, needed. 

However, the first mutants which were recognized as affecting mismatch repair were found in bacteria. The hex mutant of Streptococcus (Diplococcus) pneumoniae, which increases the transformation rate of certain markers a hundred-fold, was found to be a mutator. Transformation in S. pneumoniae involves the uptake of a single strand of donor DNA and efficiency is limited by the correction of the mutational difference between donor and recipient. In /iex-mutants, the directionality of this correction is abolished (Lacks, 1970). Subsequently a number of... 

Leuconostoc mesenteroides and Leuconostoc ssp. are found in fermented foods of plant origin [11]. The occurrence of these bacteria in sugar refineries is responsible for problems in filtration processes because of increased viscosity by the presence of soluble dextran [12,13]. Furthermore, dextran retards the rate of crystallisation of sucrose and adversely affects the crystal shape. The occurrence of dextran in the matrix of dental plaque results from certain Streptococcus strains [14]. The principle organism, Streptococcus mutans, is able to produce water-soluble glucan (named dextran) and water-insoluble... 

Cellesi C, Rossolini GM. Patterns of macrolide resistance determinants among community-acquired Streptococcus pneumoniae isolates over a 5-year period of decreased macrolide susceptibility rates. Antimicrob Agents... 

An area of increasing concern and clinical importance is the increasing macrohde resistance that has been reported over the last several years with some of the common pathogens, particularly Streptococcus pneumoniae, group A streptococci, and Haemophilus influenzae, and may result in failure of therapy of pneumonia, phar5mgitis, and skin infections (54). High rates of resistance of several groups of streptococci to macrohdes have been reported from all parts of the world (55-64). 

The aqueous/methanol fraction of the dichloromethane extract of Carthamus lanatus L. exhibited a high rate of antibacterial activity against Staphylococcus aureus and Escherichia coli [35], while crude dichloromethane extracts of the aerial parts and roots of Leontopodium alpinum Cass, exhibited significant growth inhibition of Bacillus subtilis, Escherichia coli. Pseudomonas aeruginosa. Staphylococcus aureus and Streptococcus pyogenes [36]. 

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