Antibiotic　resistance　genes　(ARGs)　including　intracellular　ARGs　(iARGs)　and　extracellular　ARGs　(eARGs)　are　harboured　in　wastewater　treatment　plants.　This　study　investigated　the　effects　of　short-term　and　long-term　cyclic　stress　on　i/eARGs　and　microbial　communities　under　high　concentrations　of　sulfamethoxazole　(SMX)　and　trimethoprim　(TMP).　Secretion　of　extracellular　polymeric　substances　(EPS)　was　inhibited　under　both　antibiotic　stress　modes.　Under　short-term　stress　of　SMX,　the　absolute　abundance　of　i-sul1　and　i-sul2,　which　belong　to　the　sulfonamide　resistance　genes,　increased,　while　i-aac,　i-mefA　and　i-intl-1　were　also　enriched.　In　contrast,　short-term　TMP　stress　had　a　limited　effect　on　iARGs,　though　the　absolute　abundance　of　dfrA12　and　dfrG　increased.　Under　long-term　cyclic　stress　of　SMX,　the　greatest　increase　in　absolute　abundance　of　i/eARG　was　observed　during　the　first　cyclic　stress　stage.　Under　both　stresses,　there　are　complex　interactions　between　iARGs　and　eARGs,　with　mobile　genetic　elements　(MGEs)　promoting　certain　subtypes　associated　with　them.　Both　stresses　notably　altered　the　intracellular　microbial　community　composition,　with　abundant,　intermediate,　and　rare　taxa　responding　differently.　Abundant　taxa　(e.g.　Brevundimonas)　were　main　potential　hosts　for　iARGs,　and　intermediate　taxa　(e.g.　Methylocystis)　and　rare　taxa　(e.g.　Paracoccus)　were　main　releasers　for　eARGs.　These　findings　provide　valuable　insights　into　the　dynamics　of　iARGs　and　eARGs　under　high　antibiotic　stress,　advancing　our　understanding　of　ARG　behavior　in　wastewater　treatment　systems.　©　2025　Elsevier　Ltd