The Comparative Effectiveness of Aureomycin, Terramycin, Chloramphenicol, Erythromycin, and Thiocymetin in Suppressing Experimental Rickettsial Infections in Chick Embryos

Ormsbee, Richard A.; Parker, Hazel; Pickens, Edgar G.

doi:10.1093/infdis/96.2.162

Cited by 41 publications

(34 citation statements)

References 8 publications

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“…Our results also indicate that this strain was not susceptible to chloramphenicol at a concentration of 8 g/ml or to ciprofloxacin at a concentration of 1 g/ml, which is not in complete agreement with the results of the previous study (17). Previous work demonstrated that the efficacies of chloramphenicol and ciprofloxacin against C. burnetii varied (14,17,25,26), depending on the dose, the culture model, and the C. burnetii strain used to test the antimicrobials. The ability of ampicillin to inhibit C. burnetii growth supports prior evidence presented by Suhan et al (21) that C. burnetii Nine Mile, phase I, is susceptible to ampicillin at 50 g/ml.…”

Section: Discussioncontrasting

confidence: 96%

Evaluation of Coxiella burnetii Antibiotic Susceptibilities by Real-Time PCR Assay

2003

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Coxiella burnetii is an obligate intracellular bacterium. The inability to cultivate this organism on axenic medium has made calculation of infectious units challenging and prevents the use of conventional antibiotic susceptibility assays. A rapid and reliable real-time PCR assay was developed to quantify C. burnetii cells from J774.16 mouse macrophage cells and was applied to antibiotic susceptibility testing of C. burnetii Nine Mile, phase I. For calculation of bacterial replication, real-time PCR performed equally as well as immunofluorescent-antibody (IFA) assay when J774.16 cells were infected with 10-fold serial dilutions of C. burnetii and was significantly (P < 0.05) more repeatable than IFA when 2-fold dilutions were used. Newly infected murine macrophage-like J774.16 cells were treated with 8 g of chloramphenicol per ml, 4 g of tetracycline per ml, 4 g of rifampin per ml, 4 g of ampicillin per ml, or 1 g of ciprofloxacin per ml. After 6 days of treatment, tetracycline, rifampin, and ampicillin significantly (P < 0.01) inhibited the replication of C. burnetii, while chloramphenicol and ciprofloxacin did not. In general, these results are consistent with those from prior reports on the efficacy of these antibiotics against C. burnetii Nine Mile, phase I, and indicate that a real-time PCR-based assay is an appropriate alternative to the present methodology for evaluation of the antibiotic susceptibilities of C. burnetii.

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Section: Discussioncontrasting

confidence: 96%

Evaluation of Coxiella burnetii Antibiotic Susceptibilities by Real-Time PCR Assay

2003

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“…With the exception of the quinolone compounds that were previously unavailable, the pattern of antibiotic susceptibilities of C. burnetii determined with infected L929 cells is similar to the results obtained by others with embryonated eggs (7,9,10,17); the effective range of antibiotic concentrations was comparable.…”

Section: Discussionsupporting

confidence: 84%

“…In this report we provide evidence that rifampin and several quinolones are effective in rapidly eliminating the parasite from chronically infected L929 cells. Unlike other host systems (embryonated eggs, guinea pigs) that have been used previously by other investigators (7,9,10,17) to determine the' antibiotic susceptibility of C. burnetii, the system we describe is more convenient and precise and it allows one to obtain drug efficacy data in a relatively short time.…”

mentioning

confidence: 99%

In vitro susceptibility of Coxiella burnetii to antibiotics, including several quinolones

Yeaman

Mitscher

Baca

1987

Antimicrob Agents Chemother

103

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Antibiotic susceptibility testing of the rickettsial Q fever agent Coxiella burnetii was performed by using persistently infected L929 fibroblast cells. The efficacies of a variety of antibiotics with different metabolic targets were tested and compared. -The most effective antibiotics in bringing about the elimination of the parasite from infected cells included several quinolone compounds and rifampin. Of the' quinolone compounds tested, 'difloxacin (A-56619) was the most effective, followed by ciprofloxacin and oxolinic' acid. These three quinolones were apparently rickettsiacidal. After 48 h of exposure to micrQgram amounts of the compounds (ranging from 2 ,,g of difloxacin per ml to'5 jig of the other two antibiotics per ml), the number of intracellular parasites markedly declined; after' 10 days of treatment, very few intracellular rickettsiae were detected.Rifampin (1 ,Ig/ml) was also very effective in eliminating the parasites. Some of the 13 other antibiotics tested that were somewhat effective included chloramphemcol, doxycycline, and trimetloprim. The persistently infected L929 cells were found-to provide a convenient system for the relatively rapid determination of the susceptibility of C. burnetii to antibiotics.Chronic endocarditis and hepatosplenomegaly are occasionally associated with persistent and relapsing infection caused by the obligate intracellular procaryotic rickettsial agent of Q fever, Coxiella burnetii (8,12,18,19). Antibiotic treatment of chronic Q fever has not been consistently effective (8,13,18); in spite of treatment, the disease can continue or relapse, resulting in life-threatening endocarditis,'usually affecting the aortic and mitral valves (13,17,18). We have developed an in vitro model of persistent Q fever consisting of cell lines persistently infected with C. burnetii. These chronically infected cell lines include L929, J774, and P388D)1 (3,4). The persistently infected L929 cells have been maintained in continuous'culture for over 3 years without the addition of normal'cells; both the host cells and parasites divide, with C. burnetii proliferating within phagolysosomes (2). Recently, we discovered that heavily infected cells are capabl,e of division; those possessing one large parasite-containing vacuole give rise to both infected and uninfected daughter cells (15). This chronically infected model system was employed in this study for examining the efficacies of several antibiotics, including several DNA gyrase inhibitors (16) of the quinolone family. In this report we provide evidence that rifampin and several quinolones are effective in rapidly eliminating the parasite from chronically infected L929 cells. Unlike other host systems (embryonated eggs, guinea pigs) that have been used previously by other investigators (7, 9, 10, 17) to determine the' antibiotic susceptibility of C. burnetii, the system we describe is more convenient and precise and it allows one to obtain drug efficacy data in a relatively short time. Rocky Mountain Laboratory, Hamilton, Mont. The plaque...

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“…Doxycycline (200 mg/day) was used in each case either alone (nine cases) or in association with the following antibiotics (in milligrams per day): rifampin (900) (four cases), ofloxacin (400) (nine cases), pefloxacin (400) (seven cases), or sulfamethoxazole-trimethoprim (one case). The durations of treatment ranged from 12 The effect of antibiotics on rickettsial agents was first studied in experimental models, such as fertile hen eggs (14,38) and tissue culture (37). The classical model for acute infection is the embryonated egg assay.…”

Section: Resultsmentioning

confidence: 99%

“…The classical model for acute infection is the embryonated egg assay. Previous investigators evaluated many antibiotics and showed that C. burnetii was more resistant to them than were other rickettsiae (14,27). They also isolated a strain (C. burnetii CYPY) resistant to tetracycline (27).…”

Section: Resultsmentioning

confidence: 99%

Comparison of different antibiotic regimens for therapy of 32 cases of Q fever endocarditis

Lévy¹,

Drancourt²,

Etienne³

et al. 1991

Antimicrob Agents Chemother

112

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We studied 32 cases of Q fever endocarditis diagnosed in France between January 1985 and December 1989 to evaluate the efficacies of the different regimens of antibiotics used for treatment. Each patient was monitored during the treatment (range, 12 to 60 months), and clinical and biological information was computerized. Various treatments were prescribed, including doxycycline alone (9 cases) or in association with rifampin (4 cases), quinolones (16 cases), or sulfamethoxazole-trimethoprim (1 case). Two patients died before the beginning of the treatment. Nineteen patients had hemodynamic failure and subsequently underwent valve replacement. Nine valve tissue cultures were positive despite previous antibiotic treatment. In terms of their effects on mortality, the difference between doxycycline alone and doxycycline plus quinolones is statistically significant. We conclude that the addition of quinolones to doxycycline is beneficial. On the basis of clinical, serological, and valve tissue culture results, no treatment was able to cure Q fever endocarditis within 2 years, even with a combination of antibiotics. We advise a minimum duration of treatment of 3 years with therapy combining quinolones and doxycycline.

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The Comparative Effectiveness of Aureomycin, Terramycin, Chloramphenicol, Erythromycin, and Thiocymetin in Suppressing Experimental Rickettsial Infections in Chick Embryos

Cited by 41 publications

References 8 publications

Evaluation of Coxiella burnetii Antibiotic Susceptibilities by Real-Time PCR Assay

Evaluation of Coxiella burnetii Antibiotic Susceptibilities by Real-Time PCR Assay

In vitro susceptibility of Coxiella burnetii to antibiotics, including several quinolones

Comparison of different antibiotic regimens for therapy of 32 cases of Q fever endocarditis

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