OLDWICK, N.J.--(BUSINESS WIRE)--A.M. Best has downgraded the financial strength rating to B+ (Good) from B++ (Good) and the issuer credit rating to “bbb-” from “bbb” of CAMICO Mutual Insurance Company (CAMICO) (San Mateo, CA). The outlook for all ratings has been revised to stable from negative. The ratings reflect CAMICO’s supportive risk-adjusted capitalization; strong market presence and expertise in the accounting professional liability market, including good geographic spread of risk; and