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Enrofloxacin and macrolides alone or in combination with rifampicin as antimicrobial treatment in a bovine model of acute Chlamydia psittaci infection.

Prohl A, Lohr M, Ostermann C, Liebler-Tenorio E, Berndt A, Schroedl W, Rothe M, Schubert E, Sachse K, Reinhold P - PLoS ONE (2015)

Bottom Line: Reisolation of the pathogen was achieved more often from untreated animals than from other groups.Nevertheless, pathogen detection by PCR was possible to the same extent in all animals and there were no significant differences between treated and untreated animals in terms of local (i.e., cell count and differentiation of BALF-cells) and systemic inflammation (i.e. white blood cells and concentration of acute phase protein LBP), clinical signs, and pathological findings at necropsy.Regardless of the reduced reisolation rate in treated animals, the treatment of experimentally induced respiratory C. psittaci infection with enrofloxacin, azithromycin or erythromycin alone or in combination with rifampicin was without obvious benefit for the host, since no significant differences in clinical and pathological findings or inflammatory parameters were detected and all animals recovered clinically within two weeks.

View Article: PubMed Central - PubMed

Affiliation: Institute of Molecular Pathogenesis at Friedrich-Loeffler-Institut (Federal Research Institute for Animal Health), Naumburger Str. 96a, 07743 Jena, Germany.

ABSTRACT
Chlamydia psittaci is a zoonotic bacterium with a wide host range that can cause respiratory disease in humans and cattle. In the present study, effects of treatment with macrolides and quinolones applied alone or in combination with rifampicin were tested in a previously established bovine model of respiratory C. psittaci infection. Fifty animals were inoculated intrabronchially at the age of 6-8 weeks. Seven served as untreated controls, the others were assigned to seven treatment groups: (i) rifampicin, (ii) enrofloxacin, (iii) enrofloxacin + rifampicin, (iv) azithromycin, (v) azithromycin + rifampicin, (vi) erythromycin, and (vii) erythromycin + rifampicin. Treatment started 30 hours after inoculation and continued until 14 days after inoculation (dpi), when all animals were necropsied. The infection was successful in all animals and sufficient antibiotic levels were detected in blood plasma and tissue of the treated animals. Reisolation of the pathogen was achieved more often from untreated animals than from other groups. Nevertheless, pathogen detection by PCR was possible to the same extent in all animals and there were no significant differences between treated and untreated animals in terms of local (i.e., cell count and differentiation of BALF-cells) and systemic inflammation (i.e. white blood cells and concentration of acute phase protein LBP), clinical signs, and pathological findings at necropsy. Regardless of the reduced reisolation rate in treated animals, the treatment of experimentally induced respiratory C. psittaci infection with enrofloxacin, azithromycin or erythromycin alone or in combination with rifampicin was without obvious benefit for the host, since no significant differences in clinical and pathological findings or inflammatory parameters were detected and all animals recovered clinically within two weeks.

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Percentage of altered lung tissue on total lung volume assessed 14 dpi at necropsy.The proportion of altered lung tissue 14 days after inoculation with C. psittaci did not differ between treated and untreated animals (many-to-one comparisons by Gao et al. (2008) with Hochberg-adjustment, P > 0.58). C: untreated controls, R: rifampicin, En: enrofloxacin, En + R: enrofloxacin + rifampicin, Az: azithromycin, Az + R: azithromycin + rifampicin, Ery: erythromycin, Ery + R: erythromycin + rifampicin. dpi: days post inoculation.
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pone.0119736.g006: Percentage of altered lung tissue on total lung volume assessed 14 dpi at necropsy.The proportion of altered lung tissue 14 days after inoculation with C. psittaci did not differ between treated and untreated animals (many-to-one comparisons by Gao et al. (2008) with Hochberg-adjustment, P > 0.58). C: untreated controls, R: rifampicin, En: enrofloxacin, En + R: enrofloxacin + rifampicin, Az: azithromycin, Az + R: azithromycin + rifampicin, Ery: erythromycin, Ery + R: erythromycin + rifampicin. dpi: days post inoculation.

Mentions: At necropsy 14 dpi, foci of bronchopneumonia and pleuritis were seen in all calves except for one rifampicin treated animal which showed no lesions. Lung alterations were corresponding to the sites where the inoculum had been applied, i.e. in the caudal part of the left and right apical lobes, the medial lobe and the basal lobes. Necrotic centers and demarcation by fibrous connective tissue were characteristic for the circumscribed pulmonary lesions. The extent of lesions ranged between 0.0% and 8.3% (median: 3.0%) of pulmonary tissue in all animals without significant differences between the treated and untreated animals (many-to-one comparisons by Gao et al. [32] with Hochberg-adjustment, P > 0.58) (Fig. 6).


Enrofloxacin and macrolides alone or in combination with rifampicin as antimicrobial treatment in a bovine model of acute Chlamydia psittaci infection.

Prohl A, Lohr M, Ostermann C, Liebler-Tenorio E, Berndt A, Schroedl W, Rothe M, Schubert E, Sachse K, Reinhold P - PLoS ONE (2015)

Percentage of altered lung tissue on total lung volume assessed 14 dpi at necropsy.The proportion of altered lung tissue 14 days after inoculation with C. psittaci did not differ between treated and untreated animals (many-to-one comparisons by Gao et al. (2008) with Hochberg-adjustment, P > 0.58). C: untreated controls, R: rifampicin, En: enrofloxacin, En + R: enrofloxacin + rifampicin, Az: azithromycin, Az + R: azithromycin + rifampicin, Ery: erythromycin, Ery + R: erythromycin + rifampicin. dpi: days post inoculation.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4358964&req=5

pone.0119736.g006: Percentage of altered lung tissue on total lung volume assessed 14 dpi at necropsy.The proportion of altered lung tissue 14 days after inoculation with C. psittaci did not differ between treated and untreated animals (many-to-one comparisons by Gao et al. (2008) with Hochberg-adjustment, P > 0.58). C: untreated controls, R: rifampicin, En: enrofloxacin, En + R: enrofloxacin + rifampicin, Az: azithromycin, Az + R: azithromycin + rifampicin, Ery: erythromycin, Ery + R: erythromycin + rifampicin. dpi: days post inoculation.
Mentions: At necropsy 14 dpi, foci of bronchopneumonia and pleuritis were seen in all calves except for one rifampicin treated animal which showed no lesions. Lung alterations were corresponding to the sites where the inoculum had been applied, i.e. in the caudal part of the left and right apical lobes, the medial lobe and the basal lobes. Necrotic centers and demarcation by fibrous connective tissue were characteristic for the circumscribed pulmonary lesions. The extent of lesions ranged between 0.0% and 8.3% (median: 3.0%) of pulmonary tissue in all animals without significant differences between the treated and untreated animals (many-to-one comparisons by Gao et al. [32] with Hochberg-adjustment, P > 0.58) (Fig. 6).

Bottom Line: Reisolation of the pathogen was achieved more often from untreated animals than from other groups.Nevertheless, pathogen detection by PCR was possible to the same extent in all animals and there were no significant differences between treated and untreated animals in terms of local (i.e., cell count and differentiation of BALF-cells) and systemic inflammation (i.e. white blood cells and concentration of acute phase protein LBP), clinical signs, and pathological findings at necropsy.Regardless of the reduced reisolation rate in treated animals, the treatment of experimentally induced respiratory C. psittaci infection with enrofloxacin, azithromycin or erythromycin alone or in combination with rifampicin was without obvious benefit for the host, since no significant differences in clinical and pathological findings or inflammatory parameters were detected and all animals recovered clinically within two weeks.

View Article: PubMed Central - PubMed

Affiliation: Institute of Molecular Pathogenesis at Friedrich-Loeffler-Institut (Federal Research Institute for Animal Health), Naumburger Str. 96a, 07743 Jena, Germany.

ABSTRACT
Chlamydia psittaci is a zoonotic bacterium with a wide host range that can cause respiratory disease in humans and cattle. In the present study, effects of treatment with macrolides and quinolones applied alone or in combination with rifampicin were tested in a previously established bovine model of respiratory C. psittaci infection. Fifty animals were inoculated intrabronchially at the age of 6-8 weeks. Seven served as untreated controls, the others were assigned to seven treatment groups: (i) rifampicin, (ii) enrofloxacin, (iii) enrofloxacin + rifampicin, (iv) azithromycin, (v) azithromycin + rifampicin, (vi) erythromycin, and (vii) erythromycin + rifampicin. Treatment started 30 hours after inoculation and continued until 14 days after inoculation (dpi), when all animals were necropsied. The infection was successful in all animals and sufficient antibiotic levels were detected in blood plasma and tissue of the treated animals. Reisolation of the pathogen was achieved more often from untreated animals than from other groups. Nevertheless, pathogen detection by PCR was possible to the same extent in all animals and there were no significant differences between treated and untreated animals in terms of local (i.e., cell count and differentiation of BALF-cells) and systemic inflammation (i.e. white blood cells and concentration of acute phase protein LBP), clinical signs, and pathological findings at necropsy. Regardless of the reduced reisolation rate in treated animals, the treatment of experimentally induced respiratory C. psittaci infection with enrofloxacin, azithromycin or erythromycin alone or in combination with rifampicin was without obvious benefit for the host, since no significant differences in clinical and pathological findings or inflammatory parameters were detected and all animals recovered clinically within two weeks.

Show MeSH
Related in: MedlinePlus