FIGURE 7.

ALG-AgNPs are a safe and effective therapeutic drug in zebrafish and mouse TB animal models. (A–C) After microinjection of M. marinum-DsRed into the caudal vein of zebrafish larvae, the infected larvae (5 fish/group/experiment) were treated with PBS, 100 μg/ml rifampicin (RIF) or 200 μg/ml ALG-AgNPs for 5 days. All data for zebrafish were from two experiments. (A) At 5 days post infection (dpi), the red fluorescence signal from M. marinum-DsRed infection was observed by fluorescence microscopy. Scale bar represents 1 mm. (B) The fluorescence signals of M. marinum-DsRed from zebrafish larvae treated with PBS (n = 10), rifampicin (n = 10) or ALG-AgNPs (n = 10) were quantified using ImageJ software and expressed as fluorescence pixels per larvae. (C) For determination of bacterial burdens, five fish/group/experiment were pooled together and homogenized in 1 ml PBS containing 1% SDS. The bacterial burdens of homogenates from infected larvae were diluted 10 $\times$ and 100 $\times$ in triplicates and enumerated by CFU analysis of two experiments. (D) BALB/c mice were intravenously infected with Mtb strain H37Ra for 14 days, then treated with PBS (n = 5), 10 mg/kg (n = 5) or 50 mg/kg (n = 5) of ALG-AgNPs, or 10 mg/kg rifampicin (n = 5) for another 14 days, then the mice were euthanized. The lungs of treated mice were collected and homogenized. The homogenates were plated on 7H10 agar plates. Bacterial growth in the lungs was determined by CFU analysis. Data in (B–D) represent mean ± SEM. *p < 0.05; **p < 0.01; ***p < 0.001.