Bacteria may be resistant to antibacterial drugs because of some alterable property of the cell or the environment ('phenotypic resistance') or some alteration of the usual genetic properties of the cell ('genotypic resistance'). Genotypic resistance can be mediated by a mutation of the bacterial chromosome or the infection of the cell by an extrachromosomal element, e.g. an R factor. The prope...

A succession of antimalarial drugs has been deployed to treat human falciparum malaria but each has, in turn, been nullified by the spread of drug resistance. The consensus view has always been that, once present, resistance will inevitably rapidly increase to 100%. However, recent field evidence has shown this is not inevitable, and that drug resistance may initially spread and then stabilize ...

www.thelancet.com Vol 381 February 23, 2013 625 The lack of participation of India and China, who between them share 50% of the world’s burden of multidrugresistant (MDR) tuberculosis, is a major limitation of the Preserving Eff ective TB Treatment (PETTS) study. Despite this limitation, the fi ndings of the PETTS investigators fi nd great and ominous resonance in India. Second-line drugs are p...

The application of chemotherapy in cancer treatment has been limited due to cause side effects such as toxicity against normal cells and drug resistance. In recent years, numerous studies have been focused on using natural products with chemotherapeutic drugs to enhance therapeutic efficiency and reduce cytotoxicity. On the other hand, encapsulation of drugs into nanoparticles (NPs) can improve...

Antibiotics have been a panacea in animal husbandry as well as in human therapy for decades. The huge amount of antibiotics used to induce the growth and protect the health of farm animals has lead to the evolution of bacteria that are resistant to the drug's effects. Today, many researchers are working with bacteriophages (phages) as an alternative to antibiotics in the control of pathogens fo...

The efficacy of cancer chemotherapy is often affected by the emergence of resistant can-cer cells. While biochemical and pharmaco-logical mechanisms have been proposed to ex-plain chemo-resistance, the genes involved in this process have not been fully identified. We previously used genomic DNA microarrays and quantitative RT-PCR to identify the genes associated with resistance to chemotherapeu...

A major issue in the control of malaria is the evolution of drug resistance. Ecological theory has demonstrated that pathogen superinfection and the resulting within-host competition influences the evolution of specific traits. Individuals infected with Plasmodium falciparum are consistently infected by multiple parasites; however, while this probably alters the dynamics of resistance evolution...

Thirty two positive sputa from 104 untreated cases of pulmonary tuberculosis, were tested for sensitivities against antituberculosis drugs. Twenty four were positive on direct smear as well as culture while 8 were only culture positive. Nine (28%) were resistant to Isoniazid, 3 (9.4%) to Streptomycin and 2 (6.3%) were resistant to both the drugs. All the 32 were sensitive to Rifampicin and Etha...

Why is drug resistance common and vaccine resistance rare? Drugs and vaccines both impose substantial pressure on pathogen populations to evolve resistance and indeed, drug resistance typically emerges soon after the introduction of a drug. But vaccine resistance has only rarely emerged. Using well-established principles of population genetics and evolutionary ecology, we argue that two key dif...