Fast anisotropic growth of the biomineralized zinc phosphate nanocrystals for a facile and instant construction of laccase@Zn3(PO4)2 hybrid nanoflowers.

Organic-inorganic hybrid nanoflowers (HNFs) of laccase@Zn3(PO4)2 were fabricated through a facile, simple, and rapid one-step strategy. In this process, laccase was involved in nucleation and fast anisotropic growth reactions with Zn (II) and phosphate ions. The average pore size of the prepared HNFs was 54.5 nm, and its BET-specific surface area was 59.5 m2 g-1. In comparison with the free laccase, the entrapped enzyme activity in the constructed HNFs was 86.4%. In addition, the hybrid biocatalyst displayed a maximum rate of reaction (Vmax) of 1640.2 ± 3.6 µmol min-1 with respect to the native enzyme. The constructed HNFs maintained 45.1% and 60% of the original laccase activity after 12 successive reusability cycles and 30 days of storage at 4 °C, respectively. The as-obtained HNFs demonstrated a high bioremoval percentage of Direct blue-71 (94.1%) within a 10-h-treatment at 40 °C and 15 mg l-1 of the dye concentration. The pseudo-first order and second order were the best-fitted kinetic models for the dye removal using Zn3(PO4)2 nanoflakes and the fabricated HNFs, respectively. Besides, liquid chromatography-mass spectrometry (LC-MS) revealed biotransformation of the dye into less toxic metabolites as verified by testing on some bacterial strains.

In vivo antibacterial activity of Zataria multiflora Boiss extract and its components, carvacrol, and thymol, against colistin-resistant Acinetobacter baumannii in a pneumonic BALB/c mouse model.

BACKGROUND: Acinetobacter baumannii has emerged as a major cause of nosocomial infections. Various resistance mechanisms of A. baumannii against antibiotics have transformed it into a successful nosocomial pathogen. Because of the limited number of available antibiotics, we used a medicinal plant with an antibacterial effect. Zataria multiflora Boiss (ZMB) extract and its components were used for the treatment of pneumonic mice infected with A. baumannii. The biological effects of this extract and the regulation of the outer membrane protein A (ompA) gene were used in a mouse model. METHODS: A pneumonic mouse model was prepared using clinical and standard strains (1.5 × 108 colony-forming units/mL) of A. baumannii. BALB/c mice groups were treated with a ZMB extract, carvacrol, thymol, and sensitive antibiotics. The lung tissues of the treated mice were cultured for 5 days and each day, bacterial clearance and the ompA gene expression were assessed by quantitative real-time polymerase chain reaction. RESULTS: In the lung tissue culture of pneumonic mice infected with standard or clinical isolate, no colony was detected when treated with the ZMB extract after 2 and 3 days (P < 0.01), respectively. In the carvacrol-treated group, bacterial clearance was seen at day 4 and day 5 (P < 0.05). Bacterial clearance was seen 5 days after treatment with thymol and imipenem and 6 days after ampicillin/sulbactam treatment. The regulation of ompA gene was significantly decreased in this order: ZMB extract, carvacrol, thymol, imipenem, and ampicillin/sulbactam. DISCUSSION: The ZMB extract had a potent bactericidal effect against A. baumannii that could downregulate the ompA gene. ZBM extract and carvacrol could be novel therapeutic agents for antibiotic-resistant A. baumannii.

Comparison of OmpA Gene-Targeted Real-Time PCR with the Conventional Culture Method for Detection of Acinetobacter baumanii in Pneumonic BALB/c Mice

Background: Acinetobacter baumannii is an important pathogen in health care and is responsible for severe nosocomial and community-acquired pneumonia. To design novel therapeutic agents, a mouse model for A. baumannii pneumonia is essential. Methods: We described a mouse model of A. baumannii using clinical and 19606R standard strains for developing a quantitative real-time PCR (qRT-PCR) for rapid identification of A. baumannii infection from lung tissues of BALB/c mice. Results: To infect the mice, three doses of bacteria (0.5 × 108, 1 × 108, and 1.5 × 108 cfu/ml) were used. Lung tissues were cultured and compared with ompA gene. Clinical isolates had better positive results at day three with the highest dose than 19606 strain either in culture (4 versus 3) or in qRT-PCR (5 versus 4). However, qRT-PCR detection was 100%, the specificity was 70%, and the positive predictive value was 27%. Conclusion: The qRT-PCR detection of A. baumannii in the BALB/c mice model has a higher sensitivity than the culture method.

Evaluation of intrinsic and acquired immune cells infiltration in kidney and spleen of the mice infected with systemic candidiasis and treated with chloroform fraction of Zataria Multiflora Boiss.

BACKGROUND AND AIMS: Despite the use of antifungal drugs, the visceral candidiasis is associated with a high mortality rate. The aims of this study were an evaluation of intrinsic and acquired immune cells infiltration in kidney and spleen of the mice infected with systemic candidiasis and treated with chloroform fraction of Zataria Multiflora Boiss. MATERIALS AND METHODS: Candida albicans (C. albicans) ATCC10231 clinical standard strain was isolated. C. albicans LD50 was determined. The laboratory animal (BALB/C mouse) infection with the visceral candidiasis was performed. The kidney and spleen tissues were stained with PAS and prepared for confirmation under the microscope. The Zataria Multiflora Boiss (Shiraz thyme) was prepared and the effects on the infected group were assessed. The kidney and spleen mononuclear cells (MNCs) were prepared and the flow cytometry technique was performed for the assessment of Th1, Th17, and Treg cells. RESULTS: The LD50 and LD totals were 1.5 × 108 and 2 × 108 Yeast/0.1 ml, respectively. In mice which had a drug intervention, including chloroform fraction of Zataria Multiflora Boiss, thymol, carvacrol or fluconazole, fungal purification was greater in the spleen than in the kidney. Among those mice without medication intervention, fungal clearance was higher in the kidney. The highest percentage of TH1 cells was in group 1 and then group 4 and in groups 2 and 3 respectively. Moreover, there was a significant difference between groups 4 and 5 and also 6 and 7. The percentage of TH1 cells in the spleen MNCs was higher than that of the kidney cells, which is the difference between the groups except for group 7. The percentage of TH17 cells in the kidney and spleen of all drug-receiving groups exhibited a significant increase compared to groups 6 and 7. The percentage of Treg cells in the kidney and the spleen only in the extract-receiving group had a significant decrease compared to the non-drug receiving group and the other groups receiving group depicted no significant difference in the percentage of Treg cells. CONCLUSION: In addition to the direct effect on the fungus proven in vitro, the extract exhibits immunosuppressive effects, and thus can degrade the fungus through this way. The results demonstrated that the fraction of Zataria Multiflora Boiss can be considered as a powerful alternative to C. albicans therapy along with other therapies.

Frequencies of CD4+ T Regulatory Cells and their CD25(high) and FoxP3(high) Subsets Augment in Peripheral Blood of Patients with Acute and Chronic Brucellosis.

OBJECTIVES: Brucellosis remains one of the most common zoonotic diseases worldwide. In humans, brucellosis can be a serious, debilitating, and sometimes chronic disease. Different mechanisms can be postulated as to the basis for the induction of the chronic status of infectious diseases that T regulatory cells are one of the most important related mechanisms. The current study was designed to determine whether percentage of CD4+Treg cells and their CD25(high) and FoxP3(high) subpopulations in peripheral blood are changed in human brucellosis samples in comparison to a control group. METHODS: In total, 68 brucellosis patients (acute form: n = 43, chronic form: n = 25) and 36 healthy volunteers entered our study. After isolating of peripheral blood mononuclear cells, heparinized venous blood samples were obtained from both patients and healthy donors, CD4, CD25, and FoxP3 molecules were evaluated by two- and three-color flow cytometric methods. RESULTS: The results revealed a new finding in relation to Treg cells and human brucellosis. The numbers of CD4(+)Treg cells and their CD25(high) and FoxP3(high) subsets increase significantly in the peripheral blood of acute and chronic forms of brucellosis samples compared with healthy groups, with this increase being greater in the chronic group. CONCLUSION: There seems to be a correlation between increase of CD4+Treg cells and their subsets and the disease progress from healthy state to acute and chronic brucellosis.