const regex = /(?:[\s\-\_\—\–\~\(\[\{\"\'\‹\«\“\‘\¡\¿\/]?(AySA)[\.\,\:\;\-\_\—\–\~\s\)\]\}\"\'\›\»\”\’\!\?\*\/]?)/gm;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('(?:[\\s\\-\\_\\—\\–\\~\\(\\[\\{\\"\\\'\\‹\\«\\“\\‘\\¡\\¿\\\/]?(AySA)[\\.\\,\\:\\;\\-\\_\\—\\–\\~\\s\\)\\]\\}\\"\\\'\\›\\»\\”\\’\\!\\?\\*\\\/]?)', 'gm')
const str = `[START]
AySA
AySA,
AySA
AySA
AySA
-AySA
_AySA
—AySA
–AySA
~AySA
(AySA
[AySA
{AySA
‹AySA
«AySA
“AySA
‘AySA
¿AySA
¡AySA
/AySA
[END]
AySA
AySA
AySA,
AySA.
AySA
AySA-
AySA_
AySA—
AySA–
AySA~
AySA)
AySA]
AySA}
AySA›
AySA»
AySA”
AySA’
AySA?
AySA!
AySA/
[BOTH]
(AySA-
Esta nueva empresa, AySA. encargada
[INVALID]
AYSA
aysa
AySa
aYsA`;
const subst = `<abbr title="Agua y Saneamiento Argentina">\1</abbr>\n`;
// The substituted value will be contained in the result variable
const result = str.replace(regex, subst);
console.log('Substitution result: ', result);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions