ST. LOUIS — St. Louis officials have run into delays implementing a plan to combine the city’s three separate 911 dispatch centers for police, firefighters and EMS, and in the meantime hold times in answering city 911 calls and serious short-staffing persist, officials told an aldermanic panel Thursday. 

Amid the delays, Daniel Isom, public safety director for Mayor Tishaura O. Jones’ administration, told the St. Louis aldermanic public safety committee on Thursday that 911 hold times remain well below national standards and understaffing has not significantly improved as more dispatchers leave even as no more hires start…