rifampin and Rodent-Diseases

The objective of this work was to evaluate the efficacy of rifampin, and its combinations with imipenem or sulbactam, in an experimental pneumonia model caused by two panresistant Acinetobacter baumannii strains (HUVR99 and HUVR113). Minimum inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) (μg/ml) of the strains were rifampin 128/>128 for both strains, imipenem 128/>256 and 256/>256 for HUVR99 and HUVR113, respectively, and sulbactam >256/>256 for both strains. In time-kill studies, at MICs, rifampin was bactericidal for both strains and sulbactam against the HUVR99 strain. Rifampin plus imipenem or sulbactam, at the MIC or mice C (max), were synergistic. In vivo, against HUVR99 and HUVR113, rifampin (73% and 40%) and its combinations improved the survival with respect to the control group (20% and 0%, p < 0.05), respectively. Rifampin (87% and 46%) and its combinations improved the sterilization of blood cultures with respect to the control groups (0%, p < 0.05). In regard to the bacterial clearance from lungs, rifampin (2.57 ± 2.47 and 5.35 ± 3.03 log(10) cfu/g) and its combinations with imipenem or sulbactam diminished the bacterial lung concentration with respect to the control group (10.89 ± 3.00 and 11.86 ± 0.49, p < 0.05) with both strains. In conclusion, rifampin alone or associated to imipenem or sulbactam were effective for the treatment of murine pneumonia caused by selected panresistant A. baumannii strains.

Topics: Acinetobacter baumannii; Animals; Anti-Bacterial Agents; Bacterial Load; Disease Models, Animal; Drug Resistance, Multiple, Bacterial; Drug Therapy, Combination; Female; Imipenem; Lung; Mice; Mice, Inbred C57BL; Microbial Sensitivity Tests; Microbial Viability; Pneumonia, Bacterial; Rifampin; Rodent Diseases; Sulbactam; Treatment Outcome

The activities of a range of antibiotics on Staphylococcus aureus organisms that survive within bovine neutrophils in vitro were studied in mice. Cloxacillin, floxacillin, and cephradine failed to kill intracellular staphylococci but increased the organisms' sensitivity to killing by lysostaphin after neutrophil disruption. Fusidate and clindamycin caused an apparent small reduction in viable intraleukocytic S aureus, whereas novobiocin did not demonstrate intracellular activity. Substantial intracellular bactericidal effects were shown in vitro by rifampin and rifamycin SV, even at concentrations in slight excess of the minimum inhibitory concentration. In a mouse model of chronic mastitis, intramammary therapy with rifampin was more effective in reducing viable S aureus in infected glands than was therapy with rifamycin SV.

Topics: Animals; Anti-Bacterial Agents; Cattle; Cloxacillin; Disease Models, Animal; Drug Therapy, Combination; Female; Leukocytes; Lysostaphin; Mastitis; Mastitis, Bovine; Mice; Neutrophils; Penicillin Resistance; Pregnancy; Rifampin; Rifamycins; Rodent Diseases; Staphylococcal Infections; Staphylococcus aureus

Topics: Animals; Cell Movement; Diptera; Humans; Immune Sera; Leishmania; Leishmaniasis; Rabbits; Rifampin; Rodent Diseases; Rodentia

Topics: Animals; Malaria; Mice; Rifampin; Rodent Diseases