Serovar, Shiga Toxin Type, Antibiotic Susceptibility and Phage Type (0157) of Shige Toxin Producing Escherichia coli Isolated from Humans in Shizuoka Prefecture (1987-2002)

Abstract

A total of 358 shiga toxin producing Escherichia coli (STEC) isolates recovered from humans between 1987 and 2002 in Shizuoka prefecture were examined to determine the prevalence of serovar, shiga toxin (Stx) type, drug-resistance and phage type (O157).
On serological and Stx typing test, the majority (213; 60.7%) of STEC isolates were identified as O157:H7 (130 producing Stx1/2, 80 producing Stx2, and 3 producing Stx1).
On antibiotic susceptibility test using 12 drugs (ABPC, TC, SM, CPFX, KM, NA, FOM, CP, CTX, ST, TMP and GM), 116 STEC isolates (36.6%) were resistant to some of the drugs, and they showed 12 drug-resistance patterns. The most prevalent drug-resistance pattern was SM/TC (35;30.2%). 7 STEC 0111 isolates (53.8%) were resistant to 3 to 7 drugs.
On phage typing scheme (0157), 222 STEC O157 isolates were classified into 27 phage pes (PT 1, 2, 4, 8, 14, 21, 23, 24, 28, 31, 32, 33, 34, 37, 41, 42, 43, 45, 46, 48, 49, 54, 56, 61, 67, 72 and 74). The most prevalent phage type was PT2 (32;14.4%). Phage types of STEC O157 isolates from the same outbreak (group or familial) were the same. These results suggest that phage typing scheme (O157) is useful in studying causative factors in epidemiological investigations.