Tigecycline: pharmacological concerns and resistance

Tigecycline, a semisynthetic derivative of minocycline, has a broad spectrum of activity against both gram positive and gram negative multidrug resistant bacteria.  The drug acts on 30S ribosomal subunit and inhibits protein synthesis. Since the drug has excellent tissue distribution, it is very useful for treatment of skin infections, intra-abdominal infections and pneumonia. Side effects of the drug are usually mild. The common side effects include nausea and vomiting. The exact mechanism of resistance remains unclear. However, resistance mediated by enhanced expression of resistance nodulation cell division (RND) type efflux pumps is one of the most frequently reported mechanisms. Resistance has been observed worldwide. However, the rate of resistance is low

An overview of carbapenem, its resistance and therapeutic options for infections caused by carbapenem resistant bacteria

Carbapenems are beta-lactam drugs that have broadest spectrum of activity. They are commonly used as the drugs of last resort to treat complicated bacterial infections. They bind to penicillin binding proteins (PBPs) and inhibit cell wall synthesis in bacteria. Important members that are in clinical use include doripenem, ertapenem, imipenem, and meropenem. Unlike other members, imipenem is hydrolyzed significantly by renal dehydropeptidase; therefore, it is administered together with an inhibitor of renal dehydropeptidase, cilastatin. Carbapenems are usually administered intravenously due to their low oral bioavailability. Most common side effects of these drugs include nausea, vomiting, diarrhea, skin rashes, and reactions at the infusion sites. Increasing resistance to these antibiotics is being reported throughout the world and is posing a threat to public health.  Primary mechanisms of carbapenem resistance include expulsion of drug and inactivation of the drug by production of carbapenemases which may not only hydrolyze carbapenem, but also cephalosporin, penicillin, and aztreonam. Resistance especially among Gram negative bacteria is of much concern since there are only limited therapeutic options available for infections caused by carbapenem resistant Gram-negative bacterial pathogens. Commonly used drugs to treat such infections include polymyxins, fosfomycin and tigecycline

Linezolid resistance in vancomycin resistant enterococci: a worrisome situation

Vancomycin resistant enterococci (VRE) have emerged as important nosocomial pathogens since 1986. VRE have been associated with higher morbidity and mortality rates than vancomycin susceptible enterococci.Of over 50 species of Enterococcus, a genus of Gram-positive cocci arranged in pairs and short chains, E. faecalis is the most common cause of infections whereas E. faecium is the species exhibiting highest rate of antibiotic resistance. VRE have been implicated in varieties of infections such as bacteremia, infective endocarditis, intra-abdominal and pelvic infections, urinary tract infections, central nervous system infections and skin and skin structure infections

Teaching Natural and Artificial Selection in Production Agriculture

In this lesson, students will learn how natural selection and artificial selection impact both production agriculture and biological sciences. A natural selection is a mechanism that favors heritable traits that increase species survival and reproduction. Artificial selection is a selective breeding, where humans select for desirable traits in agricultural products

Using Publicly Available GenBank Data to Teach Plant Phylogeny in High School Classrooms

In this teaching module, students will learn about NCBI GenBank, search for DNA/protein sequences from multiple plant species of a gene that encodes Rubisco enzyme, construct and interpret a phylogenetic tree, and discuss traits that allowed plants to adapt their life on land

Lightweight Authentication Protocol (LAUP) for 6LoWPAN wireless sensor networks

© 2017 IEEE. 6LoWPAN networks involving wireless sensors consist of resource starving miniature sensor nodes. Since secured authentication of these resource-constrained sensors is one of the important considerations during communication, use of asymmetric key distribution scheme may not be the perfect choice to achieve secure authentication. Recent research shows that Lucky Thirteen attack has compromised Datagram Transport Layer Security (DTLS) with Cipher Block Chaining (CBC) mode for key establishment. Even though EAKES6Lo and S3K techniques for key establishment follow the symmetric key establishment method, they strongly rely on a remote server and trust anchor for secure key distribution. Our proposed Lightweight Authentication Protocol (LAUP) used a symmetric key method with no preshared keys and comprised of four flights to establish authentication and session key distribution between sensors and Edge Router in a 6LoWPAN environment. Each flight uses freshly derived keys from existing information such as PAN ID (Personal Area Network IDentification) and device identities. We formally verified our scheme using the Scyther security protocol verification tool for authentication properties such as Aliveness, Secrecy, Non-Injective Agreement and Non-Injective Synchronization. We simulated and evaluated the proposed LAUP protocol using COOJA simulator with ContikiOS and achieved less computational time and low power consumption compared to existing authentication protocols such as the EAKES6Lo and SAKES