, 2000). The epidemiological relationship was studied by REP-PCR (Vila et al., 1996). Nalidixic acid susceptibility was tested using the disk-diffusion method following CLSI recommendations (CLSI, 2008). Data were statistically analyzed using the Fisher exact test due to the small size of the sample. We studied 331 vaginal samples (114 from pregnant and 217 from nonpregnant women from 16 to

50 years old) and 317 endocervical samples (271 and 46, respectively). Eighty-six (86/648, 13%) samples were positive for E. coli: 48 (15%) from pregnant and 38 (12%) from nonpregnant women. REP-PCR did not show any epidemiological relationship between isolates (data not shown). Table 2 summarizes the different virulence factors and the phylogenetic characteristics among E. coli strains in general Ceritinib purchase and stratified by pregnancy status. Phylogenetic group B2 was the most frequent among the strains (51%), followed

by groups D (34%), A (12%) and B1 (3%). Sixty percent of the strains from pregnant women were phylogenetic group B2 vs. 39% of those from nonpregnant women (P=0.043). The iroN, fyu, pap and iutA genes were the virulence factors found most frequently (57%, 53%, 51% and 41%, respectively). However, only the hly, cnf, pap and iroN genes occurred significantly 5-FU concentration more frequently when comparing the strains from pregnant women (48) with those from nonpregnant women (38) (Table 2). In contrast, the adhesin iha occurred more frequently among strains from nonpregnant women (17% vs. 39%, P=0.017). The iucD and iutA genes tended to be more frequent among strains from nonpregnant women (Table 2), but the differences were not statistically significant. No statistically significant differences were found in nalidixic acid susceptibility between E. coli strains collected from pregnant and nonpregnant women, although the strains from pregnant women presented a lower resistance to this antimicrobial agent than those from nonpregnant women. The comparison Phloretin between nalidixic acid-susceptible (67) and -resistant (19) strains showed

that those that were resistant presented hly, cnf1 and focG less frequently (Table 3). It is also of note that among nalidixic acid-susceptible strains, phylogenetic group B2 was significantly more frequent, confirming greater virulence. On the other hand, phylogenetic group D was the most frequent among nalidixic acid-resistant strains (Table 3). The predominant flora in the vagina consists of Lactobacillus and Streptococcus species; however, the presence of other bacteria such as E. coli may be very important, albeit not necessarily synonymous with infection. Vaginal E. coli may cause symptomatic infections and is associated with neonatal sepsis (Percival-Smith et al., 1983). These strains possess several virulence factors allowing vaginal and/or endocervical colonization. We analyzed the prevalence of E.