Lancet. 1979 Feb 17;1(8112):345-7.
Rapid emergence of El Tor Vibrio cholerae resistant to antimicrobial agents during first six months of fourth cholera epidemic in Tanzania.

Mhalu FS, Mmari PW, Ijumba J.

110 El Tor Vibrio cholerae isolates from 102 patients with cholera between November, 1977, and March, 1978, during the early stages of the fourth epidemic of cholera in Tanzania had minimum inhibitory concentrations to tetracycline, chloramphenicol, nitrofurantoin, neomycin, ampicillin, and sulphadimidine determined. All isolates during the first month after the disease was recognised were fully sensitive to tetracycline, but 76% of isolates were resistant to the drug after five months of extensive use of tetracycline therapeutically and prophylactically in the country. Resistance to the five other antibacterial agents developed more slowly. Isolates from patients who failed to clear the organism from their stools or who had cholera soon after tetracycline prophylaxis had increased minimum inhibitory concentrations of the drug. Resistance did not develop in vivo. Although resistance to tetracycline readily developed following extensive use of the drug, such a resistance was not the only reason for failure of tetracycline treatment and prophylaxis. Mass chemoprophylaxis in the control of cholera should be discouraged unless evidence to the contrary becomes available.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=85001&dopt=Abstract antibiotics, tetracycline




Antimicrob Agents Chemother. 1992 Aug;36(8):1738-43.
Temperature-dependent in vitro antimicrobial activity of four 4-quinolones and oxytetracycline against bacteria pathogenic to fish.

Martinsen B, Oppegaard H, Wichstrom R, Myhr E.

Department of Pharmacology and Toxicology, Norwegian College of Veterinary Medicine, Oslo.

The in vitro antimicrobial activities of oxolinic acid, flumequine, sarafloxacin, enrofloxacin, and oxytetracycline against strains of bacteria pathogenic to fish (Aeromonas salmonicida subsp. salmonicida, atypical A. salmonicida, Vibrio salmonicida, Vibrio anguillarum, and Yersinia ruckeri) were determined at two different incubation temperatures, 4 and 15 degrees C, by a drug microdilution method. The main objective of the study was to examine the effect of incubation temperature on the in vitro activities of 4-quinolones and oxytetracycline against these bacteria. When tested against A. salmonicida subsp. salmonicida, all of the quinolones examined had MICs two- to threefold higher at 4 degrees C than at 15 degrees C. Similarly, 1.5- to 2-fold higher MICs were recorded for all of the quinolones except sarafloxacin at 4 degrees C than at 15 degrees C when the drugs were tested against V. salmonicida. In contrast to those of the quinolones, the MICs of oxytetracycline were two- to eightfold lower at 4 degrees C than at 15 degrees C against all of the bacterial species tested. Of the antimicrobial agents tested against the bacterial species included in the study, enrofloxacin was the most active and oxytetracycline was the least active. Sarafloxacin was slightly more active than flumequine and oxolinic acid, especially against oxolinic acid-resistant A. salmonicida subsp. salmonicida strains.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1416857&dopt=Abstract antibiotics, tetracycline




Arch Dermatol. 1994 Jun;130(6):748-52.
Inhibition of a model of in vitro granuloma formation by tetracyclines and ciprofloxacin. Involvement of protein kinase C.

Webster GF, Toso SM, Hegemann L.

Department of Dermatology, Jefferson Medical College, Philadelphia, PA.

BACKGROUND AND DESIGN: Granulomatous inflammation is a common component of many diseases. In this study the ability of commonly used antibiotics to inhibit an in vitro model of granuloma formation were studied. The effect of protein kinase C inhibition in this system was also investigated. RESULTS: Ampicillin, cephalothin, metronidazole, rifampin, isoniazide, erythromycin, and clindamycin were inactive in inhibiting granuloma formation. Tetracycline, doxycycline, minocycline, and ciprofloxacin produced dose-dependent inhibition of the granuloma model in concentrations between 10(-4) and 10(-6) mol/L. The approximate order of descending potency was doxycycline equals minocycline greater than tetracycline greater than ciprofloxacin. The same drugs were tested for the ability to inhibit protein kinase C. Drugs inactive in the granuloma model had no effect on protein kinase C activity. The tetracyclines and ciprofloxacin all caused a dose-dependent inhibition of protein kinase C activity in the same order of relative potency as was found for inhibition of granuloma formation. CONCLUSIONS: These data demonstrate a previously unappreciated activity of the tetracyclines and ciprofloxacin. Inhibition of granuloma formation helps to account for the activity of these drugs in the severest forms of inflammatory acne.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8002645&dopt=Abstract antibiotics, tetracycline

utu.fi

The performance of two bioluminescent Escherichia coli K-12 strains for the specific detection of the tetracycline family of antimicrobial agents was compared, and the analytical applicability of one of the strains was preliminarily evaluated. One sensor plasmid contained the bacterial luciferase operon of Photorhabdus luminescens under the control of the tetracycline-responsive element from transposon Tn10 (15). An analogous plasmid construction with firefly (Photinus pyralis) luciferase reporter gene was constructed, and these two divergent tetracycline-inducible light-emitting systems were compared for their suitability for the qualitative detection of tetracyclines. Both sensor strains behaved in a similar manner kinetically, and the most sensitive tetracycline response for both sensor strains was achieved in 90-120 min by performing the assay at 37 degrees C. The sensor strain containing the bacterial luciferase operon responded slightly more sensitively to different tetracyclines than the strain containing firefly luciferase gene. The sensor bacteria retained their inducibility in lyophilization, and freeze-dried cells detected tetracyclines as sensitively as freshly cultivated sensor cells. The preliminary results from the analysis of tetracycline-spiked pork serum samples indicated that these sensor bacteria could be used to screen veterinary samples for tetracycline residues in real-time. Copyright 2000 John Wiley & Sons, Ltd.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11038486&dopt=Abstract antibiotics, tetracycline




Sex Transm Dis. 1989 Jul-Sep;16(3):132-6.
Risk factors for infection with plasmid-mediated high-level tetracycline resistant Neisseria gonorrhoeae.

Telzak EE, Spitalny KC, Faur YC, Knapp JS, Gunn RA, Blum S, Schultz S.

Division of Field Services, Center for Infectious Diseases, Atlanta, Georgia.

This study was done to determine whether the increase in high-level tetracycline resistant Neisseria gonorrhoeae (TRNG) was associated with increased tetracycline use. From 547 persons with positive cultures seen consecutively at a sexually transmitted disease (STD) clinic, 51 (9%) isolates were resistant to tetracycline. Of these 51 isolates, 37 (73%) had high-level resistance (TRNG) which was mediated by the tetM determinant located on a 25.2-megadalton plasmid. Women were twice as likely as men to have TRNG. Previous visits to an STD clinic and oral antibiotic use for a sexually transmitted disease within a one to five month period were used as surrogates for prior tetracycline use. Patients who had been to an STD clinic were almost twice as likely to have TRNG (RR = 1.9, 95% CI: 1.01, 3.46), and those who took an oral antibiotic had a relative risk of 1.8. The authors postulate that previous tetracycline use selects for tetM-containing microorganisms in the genitourinary tract that, at the time of gonococcal infection, have the ability to transfer the determinant to N. gonorrhoeae. The above findings might have implications for modifying the current Centers for Disease Control (CDC) recommendation to prescribe tetracycline for suspected Chlamydia infection among patients with gonorrhea.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2510326&dopt=Abstract antibiotics, tetracycline




Clin Infect Dis. 1993 Apr;16(4):561-6.
Antimicrobial susceptibility patterns and resistance transferability among Bacteroides fragilis group isolates from patients with appendicitis in Bali, Indonesia.

Suata K, Watanabe K, Ueno K, Homma M.

Department of Microbiology, Faculty of Medicine, Udayana University, Denpasar, Bali, Indonesia.

Patterns of antimicrobial susceptibility were determined for 155 clinical isolates of the Bacteroides fragilis group from patients with acute appendicitis in Bali, Indonesia. The transfer of drug resistance was also studied, and plasmid analyses were undertaken. Metronidazole and chloramphenicol were the most active drugs against these isolates (resistance rate, < or = 0.6%). Among the beta-lactam drugs, cefoxitin was the most active (resistance rate, 2%). Rates of resistance to tetracycline were high (16%). Resistance to clindamycin (rate, 10%) increased during the 2-year study period. Except in the case of beta-lactam agents, overall susceptibility patterns were comparable to those reported from other countries. Tetracycline resistance was more frequently transferred after tetracycline induction than without such induction (P < .05, chi 2 test). Resistance to tetracycline and clindamycin was co-transferred by five of 12 donor strains. In one of these five strains, transferability was constitutive, with a high transfer frequency (10(-5) per input donor). Plasmid analysis indicated that the transfer of resistance to tetracycline and clindamycin among the strains studied was not plasmid mediated.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8513066&dopt=Abstract antibiotics, tetracycline




Exp Parasitol. 2003 Jan-Feb;103(1-2):16-26.
Brugia pahangi and Wolbachia: the kinetics of bacteria elimination, worm viability, and host responses following tetracycline treatment.

Chirgwin SR, Nowling JM, Coleman SU, Klei TR.

Department of Pathobiological Science, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA.

Wolbachia spp., first reported from filariae nearly 30 years ago, have been suggested to contribute to the pathogenesis associated with human filarial infection. Tetracycline has been used to cure filariae of Wolbachia, as a novel means of chemotherapeutic treatment for both ocular and lymphatic filariasis. Tetracycline treatment of L4 or adult Brugia pahangi in vivo resulted in Wolbachia clearance. Less tetracycline was required to clear Wolbachia when treatment began at the L4 stage, compared with adults. Female worms died earlier than male worms when tetracycline was administered at the L4 stage. In all cases, Wolbachia clearance was closely associated with worm death. Worm recoveries decreased following the L4-L5 molt, suggesting tetracycline does not interrupt molting in this model system. Despite worm death and the assumed release of both bacterial- and worm-derived molecules, differences in inflammatory cell population and T cell cytokine mRNA profiles were negligible between tetracycline-treated and non-treated B. pahangi infected gerbils. These data suggest the contribution of Wolbachia to the in vivo induction of the gerbil immune response to B. pahangi may be small.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12810042&dopt=Abstract antibiotics, tetracycline




J Periodontol. 1995 Nov;66(11):978-83.
Slow release of tetracycline hydrochloride from a cellulose membrane used in guided tissue regeneration.

Markman C, Fracalanzza SE, Novaes AB Jr, Novaes AB.

Federal University of Rio de Janeiro, Brazil.

The objective of this study was to evaluate if the biologic membrane utilized for GTR can be impregnated by tetracycline hydrochloride and if the chemotherapeutic agent, once impregnated, can be released in minimal inhibitory concentrations for a period compatible with clinical application. Initially, an in vitro study was done with cellulose membranes cut in pieces measuring 9 cm2. A volume of 100 microliters containing a 72,000 micrograms/ml solution of tetracycline was dispensed onto each fragment, and dried for 70 minutes at 37 degrees C. Four pieces measuring 0.5 cm2 were cut from different points of the 9 cm2 membrane (presumably, containing 400 micrograms of tetracycline), placed in test tubes containing 4 ml of sterile deionized water, and agitated for 2 minutes. A standard curve was made from known concentrations of tetracycline and compared to 10 microliters of the test solutions obtained by the elution of the 0.5 cm2 fragments. The concentrations were determined through the bioassay technique in 3 duplicate experiments. The samples recovered from the membrane fragments had a mean of 101 micrograms/ml of tetracycline liberated, demonstrating that the membrane was impregnated homogeneously by the chemotherapeutic agent. In a second phase, an in vivo study was carried out to determine the length of time the drug was liberated from the membranes and at which concentrations, in the presence of an inflammatory process. Fourteen 0.5 cm2 fragments containing 400 micrograms of tetracycline were placed in 14 polypropylene chambers containing 200 microliters of thioglycolate medium. The chambers were implanted in the peritoneal cavities of 14 mice, one chamber per animal, and left in from 1 to 14 days. They were then removed and the concentrations of tetracycline determined from 20 microliters samples using a bioassay. The results showed that the antibiotic was released slowly from the 1st through the 12th day in decreasing concentrations that varied from 218 to 20.8 micrograms/ml. The impregnated cellulose membrane can probably be used in GTR acting as a membrane and as a slow-release device, liberating the chemotherapeutic agent in concentrations high enough to eliminate periodontopathic microorganisms.

Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8558400&dopt=Abstract antibiotics, tetracycline