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Introduction: Chlamydia trachomatis (chlamydia) is the most commonly diagnosed bacterial sexually transmitted infection (STI) worldwide. The advancement of molecular techniques has made chlamydia diagnostics infinitely easier. However, molecular techniques lack the information on chlamydia viability. Where in routine diagnostics the detection of chlamydia DNA or RNA might suffice, in other patient scenarios, information on the viability of chlamydia might be essential. Areas covered: In this review, the authors discuss the specific strengths and limitations of currently available methods to evaluate chlamydia viability: conventional cell culture, messenger RNA (mRNA) detection and viability-PCR (V-PCR). PubMed and Google Scholar were searched with the following terms: Chlamydia trachomatis, Treatment failure, Anal chlamydia, Microbial viability, Culture, Viability-PCR, Messenger RNA, and Molecular diagnostics Expert commentary: Several techniques are currently available to determine chlamydia viability and thus the clinical relevance of a positive test result in clinical samples. Depending on the underlying research question, all three discussed techniques have their merits when testing for viability. However, mRNA methods show the most promise in determining the presence of a true infection, in case the chlamydia reticulate body can be specifically detected. Further research is needed to understand how to best apply viability testing in current chlamydia diagnostics.

In light of unrestricted use of first-generation penicillins, these antibiotics are now superseded by their semisynthetic counterparts for augmented antibiosis. Traditional penicillin chemistry involves the use of hazardous chemicals and harsh reaction conditions for the production of semisynthetic derivatives and, therefore, is being displaced by the biosynthetic platform using enzymatic transformations. Penicillin G acylase (PGA) is one of the most relevant and widely used biocatalysts for the industrial production of β-lactam semisynthetic antibiotics. Accordingly, considerable genetic and biochemical engineering strategies have been devoted towards PGA applications. This article provides a state-of-the-art review in recent biotechnological advances associated with PGA, particularly in the production technologies with an emphasis on using the Escherichia coli expression platform., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background: The classic chromogranin-secretogranin (granin) proteins are produced in the myocardium and throughout the neuroendocrine system, but while chromogranin (Cg) A and B levels are high in the adrenal medulla, secretogranin (Sg) II production is higher in the pituitary gland. Whether these differences may influence the response to physical activity is not known., Methods: We measured circulating granin proteins during (1) a short-term maximal bicycle exercise stress test and (2) a 7 day military ranger course of continuous physical activity and sleep and energy deprivation., Results: In 9 healthy subjects performing the exercise stress test (7 male, age 45±5 y [mean±SEM], duration 10.13±1.14 min), CgB levels increased from before to immediately after the test: 1.20±0.12 vs. 1.45±0.09 nmol/L, p=0.013. Metabolic equivalents, representing an index of performed work, were closely associated with the change (∆) in CgB levels during stress testing and explained 74% of the variability in ∆CgB levels (p=0.004). CgA and SgII levels were not increased after exercise stress testing. In the second cohort of 8 male subjects (age 25±1 y) participating in the ranger course, CgB levels increased from day 1 and were significantly elevated on days 5 and 7. CgA also increased gradually with levels significantly elevated on day 7, while SgII was markedly increased on day 5 whereas levels on days 3 and 7 were unchanged compared to baseline levels., Conclusion: We demonstrate a heterogeneous response to short- and long-term physical activities among circulating granin proteins with the most potent effect on CgB levels., (© 2013.)