Absence of Escherichia coli Phylogenetic Group B2 Strains in Humans and Domesticated Animals from Jeonnam Province, Republic of Korea

Abstract

Multiplex PCR analyses of DNAs from genotypically unique Escherichia coli strains isolated from the feces of 138 humans and 376 domesticated animals from Jeonnam Province, South Korea, performed using primers specific for the chuA and yjaA genes and an unknown DNA fragment, TSPE4.C2, indicated that none of the strains belonged to E. coli phylogenetic group B2. In contrast, phylogenetic group B2 strains were detected in about 17% (8 of 48) of isolates from feces of 24 wild geese and in 3% (3 of 96) of isolates obtained from the Yeongsan River in Jeonnam Province, South Korea. The distribution of E. coli strains in phylogenetic groups A, B1, and D varied depending on the host examined, and there was no apparent seasonal variation in the distribution of strains in phylogenetic groups among the Yeongsan River isolates. The distribution of four virulence genes (eaeA, hlyA, stx 1 , and stx 2 ) in isolates was also examined by using multiplex PCR. Virulence genes were detected in about 5% (38 of 707) of the total group of unique strains examined, with 24, 13, 13, and 9 strains containing hlyA, eaeA, stx 2, and stx 1 , respectively. The virulence genes were most frequently present in phylogenetic group B1 strains isolated from beef cattle. Taken together, results of these studies indicate that E. coli strains in phylogenetic group B2 were rarely found in humans and domesticated animals in Jeonnam Province, South Korea, and that the majority of strains containing virulence genes belonged to phylogenetic group B1 and were isolated from beef cattle. Results of this study also suggest that the relationship between the presence and types of virulence genes and phylogenetic groupings may differ among geographically distinct E. coli populations.Escherichia coli is a normal inhabitant of the lower intestinal tract of warm-blooded animals and humans. While the majority of E. coli strains are commensals, some are known to be pathogenic, causing intestinal and extraintestinal diseases, such as diarrhea and urinary tract infections (42). Phylogenetic studies done using multilocus enzyme electrophoresis and 72 E. coli strains in the E. coli reference collection showed that E. coli strains can be divided into four phylogenetic groups (A, B1, B2, and D) (20,41,48). Recently, a potential fifth group (E) has also been proposed (11). Since multiplex PCR was developed for analysis of phylogenetic groups (6), a number of studies have analyzed a variety of E. coli strains for their phylogenetic group association (10,12,17,18,23,54). Duriez et al. (10) reported the possible influence of geographic conditions, dietary factors, use of antibiotics, and/or host genetic factors on the distribution of phylogenetic groups among 168 commensal E. coli strains isolated from human stools from three geographically distinct populations in France, Croatia, and Mali. Random-amplified polymorphic DNA analysis of the intraspecies distribution of E. coli in pregnant women and neonates indicated that there was a correlation between the distribution of phylog...

Long-term and short-term variations of Escherichia coli population structure in tropical coastal waters

“…The predominance of groups A and B1 is similar to other studies (Higgins et al 2007;Orsi et al 2008;Unno et al 2009). Even though the distribution of E. coli phylogenetic groups is attributed to environmental factors such as dietary, climatic conditions and geographic (Duriez et al 2001;Unno et al 2009), no apparent difference between an eutrophic estuary and an oligotrophic coastal water system was found. However, in this study, about 20 % of the isolates placed in group A did not show any amplicon.…”

“…Moreover, groups A and B1 are also closely associated with antibiotics resistance, e.g. ampicillin (Bukh et al 2009;Unno et al 2009). Therefore, the prevalence of E. coli phylogenetic groups A and B1 in the Fig.…”

“…Both groups A and B1 are commensals where group A is predominant in humans, and group B1 is predominant in animals (Tenaillon et al 2010), whereas groups B2 and D are usually pathogenic and can cause extraintestinal infections (Picard et al 1999;Clermont et al 2000). The distribution of E. coli phylogenetic groups has been attributed to environmental factors such as dietary, climatic conditions and geographic (Duriez et al 2001;Unno et al 2009). As the population structure of E. coli in humans in tropical countries are mainly groups A and B1 (EscobarPáramo et al 2004), it is essential to investigate whether the E. coli population structure in tropical coastal waters reflected that found in humans.…”

Phylogenetic Grouping of Dominant Fecal Escherichia coli Isolates from Healthy Males and Females in Al-Kut/Wasit Province/Iraq

“…In addition to the effects of diet and food processing differences between nations. Also, these differences may reflect the influence of host genetic on the commensal flora [11,25,26,31,32]. Therefore, the distribution of phylogenetic groups, subgroups and genetic markers is non-random in the hosts [33] and the four E. coli groups may differ in their ecological niches and life-history characteristics [34].…”

Phylogenetic and pathotype analysis of Escherichia coli swine isolates from Southern Brazil

“…In the phylogenetic analysis, the most abundant group was B1, followed by B2, A and D, respectively. Studies carried out with E. coli from fecal samples of several domestic animal species found pylogroups A, B1 and D were prevalent, but in swine no virulence genes were associated (Unno et al 2009). The same author report that major phylogroup found in feces were A group.…”