Soil-borne pathogens in Iraq

Mighty fascinating. One wonders at what point in history, ancient or modern, these various pathogens took hold.

When Lyles, who has a PhD in cellular and structural biology, pulled out his electronic particle counter during surveys in Iraq, it would often exceed the instrument's maximum of 700 million particles per cubic meter. He took air and dust samples at eight different sites along the Iraq-Kuwait border and Fed-Exed them to the Army Engineer Research and Development Center in Vicksburg, Mississippi. There, a team led by microbiologist Herbert Frederickson attempted to identify pathogens based on their 16s DNA sequences, and grew them up on seven different types of media, including sheep's blood agar, which indicates whether they can digest blood.

The team recovered 174 different isolates, and identified six genera of bacteria and seven genera of fungi. "Some organisms were generally located just about everywhere," Lyles says, "but some organisms were specific to some areas." The samples included strange organisms like Cryptococcus ubeqistanis and the rare Bacillus mojavensis. Lyles also found plenty of known pathogens, including Staphylococcus and Neisseria, a species of which has been implicated in meningitis outbreaks following dust storms in sub-Saharan Africa (see They came from above). He has also found possible strains of Acinetobacter, not yet confirmed by DNA analysis.