N-acetyl-cysteine increases the replication of Chlamydia pneumoniae and prolongs the clearance of the pathogen from mice

PURPOSE: Within the community, 10 % of acquired pneumonia is caused by Chlamydia pneumoniae. N-acetyl-cysteine (NAC) is one of the most commonly used mucolytics in respiratory diseases, but its effect on C. pneumoniae infection has not yet been investigated. In this study, our aim was to investigate whether NAC influences the replication of C. pneumoniae. After determining that NAC does have an effect on C. pneumoniae replication, the effect of an alternative drug called Ambroxol (Ax) was investigated. METHODOLOGY: The in vitro effect of NAC and Ax was studied on C. pneumoniae-infected A549 and McCoy cells. Furthermore, the influence of NAC and Ax was examined in mice infected intranasally with C. pneumoniae. RESULTS: NAC treatment resulted in approximately sixfold more efficient C. pneumoniae growth in tissue culture compared to the untreated control cells, and this effect was shown to be based on the increased binding of the bacterium to the host cells. The C. pneumoniae-infected mice to which NAC was given had prolonged and more severe infections than the control mice. Ax decreased C. pneumoniae replication in vitro, which was partially associated with the increased expression of indolamine 2,3-dioxygenase. In animals, using the adapted usual human dose, Ax did not alter the number of recoverable C. pneumoniae. CONCLUSION: Based on our results, it might be recommended that a mucolytic agent other than NAC, such as Ax, be used in respiratory diseases suspected to be caused by C. pneumoniae

Antiviral, antimicrobial and antibiofilm activity of selenoesters and selenoanhydrides

Selenoesters and the selenium isostere of phthalic anhydride are bioactive selenium compounds with a reported promising activity in cancer, both due to their cytotoxicity and capacity to reverse multidrug resistance. Herein we evaluate the antiviral, the biofilm inhibitory, the antibacterial and the antifungal activities of these compounds. The selenoanhydride and 7 out of the 10 selenoesters were especially potent antiviral agents in Vero cells infected with herpes simplex virus-2 (HSV-2). In addition, the tested selenium derivatives showed interesting antibiofilm activity against Staphylococcus aureus and Salmonella enterica serovar Typhimurium, as well as a moderate antifungal activity in resistant strains of Candida spp. They were inactive against anaerobes, which may indicate that the mechanism of action of these derivatives depends on the presence of oxygen. The capacity to inhibit the bacterial biofilm can be of particular interest in the treatment of nosocomial infections and in the coating of surfaces of prostheses. Finally, the potent antiviral activity observed converts these selenium derivatives into promising antiviral agents with potential medical applications.The study was supported by the project SZTE ÁOK-KKA 2018/270-62-2 of the University of Szeged, Faculty of Medicine. Gabriella Spengler was also supported by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences. The authors of this paper received funding from the Márton Áron Research Programme financed by the Hungarian Ministry of Foreign Aairs and Trade. AK was supported by the New National Excellence Program (ÚNKP-18-3) of the Ministry of Human Capacities of Hungary and by the Campus mundi short-study program of the Tempus Public Foundation. EDA was supported by the Spanish “Consejo Superior de Investigaciones Científicas” (201780I027) (CSIC, Spanish National Research Council). CSM wishes to express gratitude to UNED-Pamplona, Fundación Bancaria “La Caixa”, and “Fundación Caja Navarra” for financial support for the project. JMAB and HEM are supported by a BBSRC David Phillips Fellowship to JMAB (BB/M02623X/1)

RNA-DNA hybrid (R-loop) immunoprecipitation mapping: an analytical workflow to evaluate inherent biases

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A Practical Approach for Quantitative Polymerase Chain Reaction, the Gold Standard in Microbiological Diagnosis

From gene expression studies to identifying microbes, quantitative polymerase chain reaction (qPCR) is widely used in research and medical diagnostics. In transmittable diseases like the Ebola outbreak in West Africa (2014–2016), or the present SARS-CoV2 pandemic qPCR plays a key role in the detection of infected patients. Although the technique itself is decades old with reliable approaches (e.g., TaqMan assay) in the diagnosis of pathogens many people showed distrust in it during the SARS-CoV2 outbreak. This came mainly from not understanding or misunderstanding the principles of qPCR. This situation motivated us to design a simple laboratory practical class, in which students have opportunities to understand the underlying principles of qPCR and its advantages in microbiological diagnosis. Moreover, during the exercise, students can develop skills such as handling experimental assays, and the ability to solve problems, discuss their observations. Finally, this activity brings them closer to the clinical practice and they can see the impact of the science on real life. The class is addressed to undergraduate students of biological sciences