Medical tourism has made headlines lately, as the threat posed by the spread of antibiotic-resistant microorganisms becomes a global problem. Online news reports (Marchione, 2010) announced yesterday that three different strains of antibiotic resistant bacteria have now been identified in the United States, and predicted that we are on the verge of a health crisis. Amid this threat, researchers are using every biotech tool for protein purification, gene cloning etc. at their disposal in attempts to identify, track, and treat infections with the most virulent strains. This month in Lancet, a combination epidemiological/molecular study was reported that tracked the multi-drug resistant Enterobacteriaceae that have made their way from India and Pakistan to the UK, apparently primarily via medical tourism. PCR typing and pulsed-field gel electrophoresis were among the methods used to identify 44 isolates of E. coli, Klebsiella and other organisms expressing the enzyme metallo-beta-lactamase 1 (NDM-1), which confers resistance to carbapenems, a class of broad spectrum antibiotics. Most of the organisms expressed the gene for this enzyme on a plasmid, which can serve as a vector for easy transfer of the gene to other organisms. Our hope might be in the fact that many organisms will "kick out" a plasmid that they don't need to survive, failing to pass it on to their progeny. Thus, maybe if we humans quit overusing antibiotics, or start/continue to use them properly, some strains will cease to be resistant over the course of a few generations.
It should be noted that two of the three US cases were people who had undergone necessary medical care while out of country, due to illness or accident, and the third was a visitor to the US, and all three survived.
Marchione, M. New drug-resistant superbugs found in 3 states. Associated Press, Monday September 13, 2010.
Kumarasamy, K. et al. Emergence of a new antibiotic resistance mechanism in India, Pakistan, and the UK: a molecular, biological, and epidemiological study. The Lancet Infectious Diseases 10(9):597-602. doi:10.1016/S1473-3099(10)70143-2