Mumbai (Thomson Financial) - Moody's Investors Service said Las Vegas strip casino resort operators should be able to avoid ratings downgrades due to the economic downturn, but will be vulnerable to negative rating actions if the slowdown is prolonged or takes a turn for the worse. 'The Las Vegas resorts are not as recession-resistant as they used to be,' Moody's said. It said most operators have some room within their respective rating categories to withstand negative trends...