Journal of Antimicrobial Agents

Objective: In recent years, antiviral products modified with various antiviral agents are now widely studied and developed. The establishment of appropriate antiviral testing methods for such products is necessary to discuss the efficiency of antiviral agents in the products. In this study, quantitative antiviral testing methods for textile fabrics were studied under several test conditions.

Method: Influenza virus and feline calicivirus were used as model viruses. A cotton fabric and a 100% polyester fabric were used as control samples and Ag nanoparticles were used as model antiviral agents. In testing the antiviral performance of a product with an antiviral treatment, a virus suspension is inoculated onto the product and subsequently washed out of the products. The virus infectivity titer in the washed-out suspension is then measured. The viral infectivity titer of the test suspension was determined by counting the plaque-forming units (PFU). In estimating the antiviral activity of textile products, the components of the virus suspension, the contact time, and the contact temperature were chosen as study points.

Results: The virus infectivity titer was significantly affected by experimental conditions such as the concentration of the medium of the virus suspension, the contact temperature, and the type of textile fabric support. To estimate the antiviral efficiency under stable conditions for viruses, a lower temperature and a lower Eagle’s minimal essential medium (EMEM) concentration appear to be appropriate. It was confirmed that Ag nanoparticles on textile fabrics have antiviral activity; however, this antiviral activity was suppressed in media of high concentrations.

Conclusions: It was shown that inactivation of antiviral agent might be caused by components of the virus suspension, as well as by other experimental conditions. Furthermore, the viruses can be deactivated by contact with textile fabrics, even in the absence of antiviral agents. These findings indicate that the antiviral performance testing conditions must be carefully chosen with due consideration of the field of application.

As a result of the continuous evolution of microbial pathogens towards antibiotic-resistance, therefore development of new and effective antimicrobial compounds. Source of novel antimicrobial metabolites. Further, the antimicrobial metabolites were extracted from the isolate using ethyl acetate solvents and the antimicrobial efficacies were screened by chemical analysis and tested against bacterial pathogens. The metabolites of isolate showed maximum zone of inhibition against all the pathogens viz., Pseudomonas aeruginosa, Escherichia coli, Klebsilla pneumoniae, Bacillus cereus and Staphylococcus aureus as 21 ± 0.12, 20 ± 0.42, 21 ± 1.2, 16 ± 2.01, 15 ± 0.47 respectively. The marine samples which displayed antibacterial activity of actinomycetes may be useful in the clinical conditions where higher secondary metabolites against antibiotic resistant bacteria.

Competence development for natural genetic transformation is widespread in bacteria, although it is a transient physiological state in which bacteria are capable of taking up and integrating exogenous DNA. Activation of competence enables the recipient bacteria to gain new genes, promoting the emergence of genetic variation, antibiotic resistance and evolution of virulence factors. It has been well studied that competence activation in bacteria requires one or more signal transduction pathways, many competence proteins and a complex regulatory network, which are finely controlled by a competence-specific master regulator. In the Genus Streptococcus, an alternative sigma factor, SigX coded by comX, is such a master regulator. The transcriptional activation of comX is the key step of competence induction in nearly all members of Streptococci. Although much is known of the regulatory cascade leading to competence induction, it was not until recently that a negative regulation of competence by a mechanism that involves regulated proteolysis of SigX has been recognized to play an important role in competence development in these bacteria. In particular, an adaptor protein MecA is found to target SigX for degradation by the proteases ClpC/ClpP, profoundly affecting the stability of SigX during competence development. Interestingly, SigX-mediated competence appears to be antagonistically connected with antibiotic-induced stress response by an unknown mechanism that involves activities of MecA and the Clp protease family. This discovery has added a new level of the complexity of competence regulatory network in Streptococci, leading to further investigation of such proteolytic regulation in competence, stress response, and antibacterial therapy.

Invasive fungal infections (IFI) are not frequently seen in systemic lupus erythematosus (SLE). However, when present they are very dangerous, being potentially fatal in the majority of cases. Immunosuppressive therapy is the strongest risk factor for IFI and correlates with death during infective episodes. However, IFI may reveal SLE in a patient without any precedent disease and in the absence of other causes of immunosuppression. We report a case of invasive pulmonary fungal infection (IPFI) revealing SLE. We report a new case of IFI revealing a SLE.