Spiroplasma. which are known pathogens and commensals of arthropods and plants. are helical-shaped bacteria that lack a peptidoglycan layer. Spiroplasma swim by alternating between left- and right-handed helicity. https://www.roneverhart.com/MagnaFlow-OEM-Grade-Federal-EPA-Compliant-Direct-Fit-Catalytic-Converter-51821/