Tetracycline infection

Resistance to Tetracyclines. The tetracyclines stiU provide inexpensive and effective treatment for several microbial infections, but the emergence of acquired resistance to this class of antibiotic has limited their clinical usehilness. Studies to define the molecular basis of resistance are underway so that derivatives having improved antibacterial spectra and less susceptibiUty to bacterial resistance may be developed. Tetracyclines are antibiotics of choice for relatively few human infections encountered in daily clinical practice (104), largely as a result of the emergence of acquired tetracycline-resistance among clinically important bacteria (88,105,106). Acquired resistance occurs when resistant strains emerge from previously sensitive bacterial populations by acquisition of resistance genes which usually reside in plasmids and/or transposons (88,106,107). Furthermore, resistance deterrninants contained in transposons spread to, and become estabUshed in, diverse bacterial species (106). 

A combination of amphotericin B, miconazole (16), and rifampin (17) was used to successfully cure one patient. In addition, tetracycline (7) and minocycline (18) have been recommended although their clinical efficacy have not been estabUshed. No proven therapeutic agents exist for treating A.catbamoeba infections, however, the phenothiazines, trifluoperazine [117-89-5] and chlorpromazine [50-53-3], show promise in vitro. 

The infection can be cured most readily with tetracycline (7), oxytetracycline (3), or chlorotetracycline (20). Metronidazole (1) and iodoquinol (2) are also effective. Additional effective dmgs include paromomycin (8), tinidazole (11), sulfadiazine (25), and carbarsone [121 -59-4] (31, -ureidobenzenearsonic acid, CyH AsN204, Ameban). 

This highly lipophilic tetracycline is the first "one-a-day" tetracycline (when used to treat mild infections). 

The discovery and production of antibiotics has been of tremendous importance to human and animal health care. Prior to their discovery about half a century ago, many bacterial infections caused debilitating diseases and fatalities were high. The discovery of antibiotics was a major step in the treatment of infectious diseases, especially those caused by bacteria. Today about 50,000 tonnes of antibiotics are produced annually. About a third of this consists of penicillins, whilst tetracyclines make up about a quarter of the market. 

Tetracycline and its derivative doxycycline are antibiotics widely used in the treatment of bacterial infections. They also exert an antimalarial activity. Tetracyclines inhibit the binding of aminoacyl-tRNA to the ribosome during protein synthesis. 

The tetracyclines are a group of anti-infectives composed of natural and semisynthetic compounds. They are useful in select infections when die organism shows sensitivity (see Chap. 7) to the tetracyclines, such as in cholera, Rocky Mountain spotted fever, and typhus. 

These antibiotics are effective in die treatment of infections caused by a wide range of gram-negative and gram-positive microorganisms. The tetracyclines are used in infections caused by Rickettsiae (Rocky Mountain spotted fever, typhus fever, and tick fevers). Tetracyclines are also used in situations in which penicillin is contraindicated, in the treatment of intestinal amebiasis, and in some skin and soft tissue infections. Oral... 

ORAL ADMINISTRATION. To control the infectious process or prevent a bacterial infection, the nurse must keep several important things in mind when administering the tetracyclines, macrolides, and lincosamides. 

Cholera is a serious infection causing epidemics throughout Asia. Although a toxin-mediated disease, largely controlled with replacement of fluid and electrolyte losses, tetracycline has proved effective in eliminating the causative vibrio from the bowel, thereby abbreviating the course of the illness and reducing the total fluid and electrolyte losses. 

Preexisting antimicrobial resistance is an increasing cause of treatment failure and is estimated to account for up to 70% of all treatment failures. Geography is the most important factor in HP resistance. Metronidazole-resistant strains are more prevalent in Asia (85%) than North America (30%).15 Primary resistance to amoxicillin and tetracycline remains low in both the United States and Europe. Clarithromycin resistance rates are estimated to be approximately 10% in the United States. Another confounding factor when evaluating potential antibiotic resistance is that culture and sensitivity studies are not routinely performed with HP infection. 

Bosshardt, S.C., McCall, J.W., Coleman, S.H., Jones, KL., Petit, T.A. and Klei, T.L. (1993) Prophylactic activity of tetracycline against Brugia pahangi infection in Jirds (Meriones unguiculatus). Journal of Parasitology 79, 775-777. 

Sucharit, S., Viraboonchai, S., Panavut, N. and Harinasuta, C. (1978) Studies on the effects of tetracycline on Brugia pahangi infection in Aedes togoi. Southeast Asian Journal of Tropical Medicine and Public Health 9, 55-59. 

Tetracycline Demeclocy dine, minocycline, and tetracycline Syphilis, chlamydial infections and Lyme disease, mycoplasmal diseases and acne rickettsial infections... 

The objective of antibiotic treatments is to reduce the density of microbial pathogen in infected udder tissues and thereby improve the capacity of the animal s immune system to deal with the infection. The effect of a successful antibiotic treatment is therefore self-cure of mastitis (Hamann and Kromker, 1999). However, some antibiotics (e.g. tetracycline and gentamycine) may also have negative side effects on the animal s immune response to udder infection, as they have been shown to inhibit/reduce phagocytosis of the animal s own defence cells (Nickerson et al 1986). 

Systemic therapy with a variety of (3-lactams, macro-lides and lincosamides (clindamycin) has been the cornerstone of skin infection therapy for many years [17]. However, topical antibiotics can play an important role in both treatment and prevention of many primary cutaneous bacterial infections commonly seen in the dermatological practice [18], Indeed, while systemic antimicrobials are needed in the complicated infections of skin and skin structure, the milder forms can be successfully treated with topical therapy alone [18], The topical agents used most often in the treatment of superficial cutaneous bacterial infections are tetracyclines, mupirocin, bacitracin, polymyxin B, and neomycin. 

Fig. 1. Cumulative subjective plus objective symptom score after 10-day topical application of rifaximin (5% cream, n = 30, R) or chlor-tetracycline (3% cream, n = 30, C) of patients with pyogenic skin infections (from Della Marchina et al. [30]).00 p < 0.01 versus basal value (day 0) p < 0.01 between the two groups. 

The broad antibacterial activity of rifaximin as well as its topical action make this antibiotic suitable for intrapocket administration in periodontal disease. As a matter of fact, local application of rifaximin compares well with tetracyclines and metronidazole in other extra-GI diseases, i.e. skin infections and BY, respectively (see above). On the other hand, rifampicin (rifampin), another rifamy-cin derivative, has been successfully used in the treatment... 

Tetracyclines inhibit P. acnes, reduce the amount of keratin in sebaceous follicles, and have antiinflammatory properties (inhibiting chemotaxis, phagocytosis, complement activation, and cell-mediated immunity). Drawbacks to tetracyclines include hepatotoxicity and predisposition to infections (e.g., vaginal candidiasis). Other adverse effects include GI disturbances, photosensitivity, tooth discoloration in children, and inhibition of skeletal growth in the developing fetus. Tetracyclines must not be combined with systemic retinoids because of an increased risk of intracranial hypertension. / Tetracycline is the least expensive agent in this class and is often... 

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