Staphylococci tetracyclines

A senior British government veterinarian stated in 1962 (3)> When penicillin was first used in treating mastitis only 2% of the strains of staphylococci recovered from cases of mastitis were resistant to penicillin. Today the figure is over 70%. Between 1958 and 1961, resistance to penicillin (PEN) increased from 62.0% to 70.6%. Resistance to streptomycin (STR), tetracycline and chloramphenicol also increased (. Antibiotic resistance increased for isolates of both mastitis staphylococci and streptococci in Canada between I960 and 1967 (5). In Belgium (6), Staphylococcus aureus strains isolated from cases of bovine mastitis showed increase in PEN resistance from 38% in 1971 to 78% in 1974> but then no further increase to 1980. The resistance situation was reported to remain stable in the Federal Republic of Germany between 1962 and 1975 (7), as also in Australia between 1974 and 1979 (8 ) and Denmark, at a very low level, for the period 1963 to 1978 (9). 

Multiply resistant coagulase-negative staphylococci are frequently the cause of postoperative endophtalmitis and require the use of a glycopep-tide (e.g. vancomycin). For topical treatment fusidic acid eye gel, tetracycline or chloramphenicol ointment are available, and can be administered 2 t.d. for 7 days. Trachoma should be treated with an oral macrolide (e.g. a single oral dose of 20 mg/kg azithromycin) or doxycyclin for 3 weeks (for moderate to severe cases). Keratitis needs hourly administration of fortified antibiotic eye drops for 2 weeks. Endophtalmitis needs specialist treatment for 6 weeks. 

Tetracyclines modify the normal flora, with suppression of susceptible coliform organisms and overgrowth of pseudomonas, proteus, staphylococci, resistant conforms, Clostridia, and Candida. This can result in intestinal functional disturbances, anal pruritus, vaginal or oral candidiasis, or enterocolitis with shock and death. 

Rx of pneumonia, skin, soft tissue Infxns, osteomyelitis caused by penicillinase-producing staphylococci Action Bactericidal X cell wall synth Dose Adults. 250-500 mg qid Feds <40 kg, 12.5-100 mg/kg/d - qid take on empty stomach Caution [B, ] Contra Component orPCN sensitivity Disp Caps 125, 250, 500 mg soln 62.5 mg/5 mL SE N/D, abd pain Interactions T Effects W/ disulfiram, probenecid T effects OF MRX, X effects W/ macrolides, tetracyclines, food X effects OF OCPs, warfarin EMS Monitor for signs of electrolyte disturbances and hypovolemia d/t D OD May cause N/V/D, behavior changes, urinary retention, skin rash and Szs symptomatic and supportive... 

Although novobiocin has been used alone or with other drugs, such as rifampicin or tetracycline, in the treatment of infections due to staphylococci and other susceptible organisms, it has largely been superseded by other drugs because of the problems of resistance and toxicity. 

Tetracycline was discovered after a team of workers examined 100000 soil samples from around the world. Tetracycline derivatives include chlor-tetracycline, oxytetracycline, doxycycline and minocycline. The tetracyclines have a broad spectrum of activity they are effective against Grampositive and Gram-negative bacteria, some anaerobes. Chlamydia, Mycoplasma, Ehrlichia and Rickettsia spp. and some protozoa. Their activity against staphylococci is usually limited and they are not active against enterococci. E. coli, Klebsiella, Proteus and Pseudomonas spp. are usually resistant. Doxycycline and minocycline are usually more active in vitro than the other tetracyclines. Differences in the clinical efficacy of the tetracyclines can be attributed to differences in the absorption, distribution and excretion of the individual drugs rather than to differences in bacterial susceptibility. 

C 60. 387ft H 5.95%. N 9.187ft O 24.48%. Semi-synthetic antibiotic effective against tetracycline-resistant staphylococci. Prepn Boothe, Petisi, U.S, pats. 3,140,212 and... 

In most cases involving the empiric use of aminoglycosides, coverage for possible staphylococcal infection would involve combined use with nafcilUn or a cephalosporin (not listed). Amoxicillin is susceptible to penicillinases produced by most staphylococci, and though clavu-lanic acid is an inhibitor of these enzymes it would not be used independently of a penicillin. Many staphylococcal strains are resistant to tetracyclines. The answer is (D). 

Oleandomycin, a 14-membered ring macrolide antibiotic, was isolated in 1956 from fermentation broths of Streptomyces antibioticus [360]. Some years later, oleandomycin was assigned the structure 340 on the basis of its chemical degradation [361]. Oleandomycin is effective, but less potently, against the same spectrum of bacteria as erythromycin, namely Gram-positive bacteria such as staphylococci, streptococci, and pneumococci. The antimicrobial activity of oleandomycin, when combined with tetracycline, is potentiated. In fact, in such a combination it is sold as an antibacterial agent for upper and lower respiratory tract infection. 

Orally administered antibiotic used for treatment of tetracycline-resistant staphylococci and diseases caused by nckettsia. 

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