Fosfomycin, an antibiotic, possessed TGF-beta-like immunoregulatory activities

Fosfomycin modifies the replication kinetics of bovine alphaherpesvirus-1 and reduces the timing of its protein expression on bovine (MDBK) and human (SH-SY5Y) cell lines

Bovine alphaherpesvirus 1 (BoAHV-1) predisposes cattle to respiratory secondary bacterial infections, which can be treated with the broad-spectrum antibiotic fosfomycin. This drug also suppresses NF-kB activity and pro-inflammatory responses. Therefore, cattle may be exposed to an interaction between the virus and the antibiotic which may have effects on it. The aim of this study was to determine the effect of calcium fosfomycin (580 µg/mL) on BoAHV-1 (moi = 0.1) replication. Two cell lines (MDBK and SH-SY5Y) were used in this study. Our results show that fosfomycin has novel properties. By MTT assay we have shown that it is non-cytotoxic for any of the cell lines. Extracellular and intracellular viral titers demonstrated that fosfomycin has a cell-type and time-dependent effect on BoAHV-1 replication. By direct immunofluorescence it was shown that it reduces the timing of BoAHV-1 protein expression, and by qPCR, we found that its effect on NF-kB mRNA expression depends on the cell type.

Fosfomycin suppresses RS-virus-induced Streptococcus pneumoniae and Haemophilus influenzae adhesion to respiratory epithelial cells via the platelet-activating factor receptor

Human respiratory syncytial virus (RSV) sometimes causes acute and severe lower respiratory tract illness in infants and young children. The platelet-activating factor (PAF) receptor, which is a receptor for Streptococcus pneumoniae and Haemophilus influenzae, is upregulated by RSV infection in the pulmonary epithelial cell line A549. Fosfomycin, an antimicrobial agent, significantly suppressed PAF receptor induction by RSV infection at the mRNA and cell surface expression levels. Fosfomycin also suppressed RSV-induced adhesion of fluorescence-labeled S. pneumoniae and H. influenzae cells, as determined by flow cytometry and fluorescence microscopy. The RSV-induced bacterial adhesion was suggested to be host-PAF-receptor and bacterial-phosphocholine mediated. Fosfomycin, which has been shown to exhibit antimicrobial and immunomodulatory activities, was found here to suppress adhesion by disease-causing bacteria. Thus, fosfomycin might prevent secondary bacterial infection during RSV infection.

Immunomodulatory actions of antibiotics

Introduction. Antimicrob drugs and immune system interaction has been studied since the pioneer works of Metchnikoff. After the introduction of antibiotics in clinical practice this area has attracted little attention of investigators, because of the lack of standards. This is the reason that the studying of the influence of antibiotics on immune system is still at its beginning. Aim: To point out the immunomodulatory action of some antibiotics on certain components of immune system. Methods and results. The literaure findings show that antibiotics exspress immunomodulatory action on some components of immune system such as fagocytes (polymorphonucleary, macrophages, monocytes), cytokines, immunoglobulines, and on cellular immunity. The principles of antibiotics action on phagocyte are the inhibition of chemotaxis and oxidants production. Macrolides applied for a short time enchance the phagocytic functions while their long use leads to immunosupression. Some cephalosporines and rifampicin in therapeutic doses inhibit the oxydative metabolism of macrophages. Tetracyclines, clindamycines, chloramphenicol and tobramycin inhibit the synthesis of superoxyd anione. The action of some antibiotics on cytokine and specific antibodies is also important. Cellular immunity can be affected as well. After administration of certain antibiotics it takes 1-2 weeks to reestablish normal cellular immunity, and for other even more. Conclusion. There is still no clear standing on real effects of antibiotics on the immune system. Clinicians should search for more information from this new-old field of investigation in order to give more adequate therapy to patients.

Immunomodulatory effects of fosfomycin in experimental human endotoxemia

To evaluate the effect of fosfomycin on proinflammatory cytokines, a bolus of 2 ng of bacterial lipopolysaccharide/kg of body weight was injected intravenously into healthy volunteers. After 2 h, subjects received 8 g of fosfomycin or placebo in a randomized crossover study design. The resulting concentrations of tumor necrosis factor alpha, interleukin-1beta (IL-1beta), and IL-6 expressed as protein and mRNA levels were almost identical with and without fosfomycin.

Fosfomycin inhibits NF-kappaB activation in U-937 and Jurkat cells

Fosfomycin exerts anti-inflammatory effects through inhibiting the production of proinflammatory cytokines. Transcription of the genes for these proinflammatory cytokines is regulated by NF-kappaB. We tested the hypothesis that fosfomycin inhibits the activation of NF-kappaB induced by tumor necrosis factor-alpha (TNF-alpha) in human monocytic U-937 cells, and a T cell line (Jurkat). Western blot analysis demonstrated that fosfomycin inhibits NF-kappaB activation in both cells. Flow cytometry revealed that fosfomycin suppresses NF-kappaB activation in both cells in a dose-related manner. These findings are consistent with the idea that fosfomycin suppresses the production of proinflammatory cytokines via inhibition of NF-kappaB activation.

Fosfomycin nebulizer therapy to chronic sinusitis

OBJECTIVE

effects of Fosfomycin (FOM) nebulizer therapy were studied in patients with chronic sinusitis.

METHODS

about 28 patients with chronic sinusitis were administered 2 ml of FOM sodium (3% w/v) by nebulizer three times per week for 4 weeks. Levels of IL-1 beta, IL-6, IL-8, and TNF-alpha in nasal lavage were also measured before and at the end of treatment.

RESULTS

the overall efficacy of this treatment on the basis of both subjective and objective symptoms, was 'excellent' for 28.6%, 'good' for 10.7%, 'fair' for 39.4%, and yield 'no change' for 21.4% of the patients. Both IL-1 beta and IL-6 concentrations were significantly decreased after treatment. Although the IL-8 level did not significantly decrease, it seems to be related to the overall efficacy. TNF-alpha was not detected in all of the samples.

CONCLUSION

FOM nebulization therapy is highly effective in treatment for chronic sinusitis, and efficacy may be due to an immunomodulatory mechanism, as well as its bactericidal effect.