ปลาเน่าตัวเดียวเหม็นทั้งข้อง

Etymology
🇰🇲; literally "one rotten fish spoils the whole basket"; probably from or influenced by the following old stanza:


 * bplaa-ráa pan hɔ̀ɔ dûai · bai kaa
 * ai gɔ̂ɔ měn kaao bplaa · klá-klúng
 * kʉʉ kon mùu bpai hǎa · kóp pʉ̂ʉan paan naa
 * dâai dtɛ̀ɛ ráai ráai fúng · fʉ̂ʉang hâi sǐia pong


 * The man who wraps putrid fish with sacrificial grass finds that the grass itself emits a fetid odor; even such is the case by association with a fool.

Proverb

 * 1)  one bad person ruins the entire community; one bad person negatively influences everyone he comes into contact with; one bad person ruins everyone who associates with him.