▁an ap hy la xis , ▁inter st it ial ▁ne ph rit is ) ▁to ▁any ▁ β - la ct am ▁ant ib i otic . ▁ ▁A ▁Jar isch – Her x heimer ▁reaction ▁may ▁occur ▁after ▁initial ▁treatment ▁of ▁a ▁sp iro ch etal ▁in fection ▁such ▁as ▁sy ph ilis ▁with ▁a ▁ β - la ct am ▁ant ib i otic . ▁ ▁Mode ▁of ▁action ▁▁▁▁ β - la ct am ▁ant ib iot ics ▁are ▁b acter i oc idal , ▁and ▁act ▁by ▁in hib iting ▁the ▁synth esis ▁of ▁the ▁pe pt id og ly can ▁layer ▁of ▁b acter ial ▁cell ▁walls . ▁The ▁pe pt id og ly can ▁layer ▁is ▁important ▁for ▁cell ▁wall ▁struct ural ▁integrity , ▁especially ▁in ▁Gram - pos itive ▁organ isms , ▁being ▁the ▁outer most ▁and ▁primary ▁component ▁of ▁the ▁wall . ▁The ▁final ▁trans pe pt id ation ▁step ▁in ▁the ▁synth esis ▁of ▁the ▁pe pt id og ly can ▁is ▁facil itated ▁by ▁D D - trans pe pt id ases , ▁also ▁known ▁as ▁pen ic ill in ▁binding ▁prote ins ▁( P B P s ). ▁P B P s ▁vary ▁in ▁their ▁aff inity ▁for ▁pen ic ill in ▁and ▁other ▁ β - la ct am ▁ant ib iot ics . ▁The ▁number ▁of ▁P B P s ▁var ies ▁between ▁b acter ial ▁species . ▁▁ β - la ct am ▁ant ib iot ics ▁are