ESBL-producing <i>Escherichia coli</i> and Its Rapid Rise among Healthy People

Abstract

Since around the 2000s, Escherichia coli (E. coli) resistant to both oxyimino-cephalosporins and fluoroquinolones has remarkably increased worldwide in clinical settings. The kind of E. coli is also identified in patients suffering from communityonset infectious diseases such as urinary tract infections. Moreover, recoveries of multi-drug resistant E. coli from the feces of healthy people have been increasingly documented in recent years, although the actual state remains uncertain. These E. coli isolates usually produce extended-spectrum β-lactamase (ESBL), as well as acquisition of amino acid substitutions in the quinolone-resistance determining regions (QRDRs) of GyrA and/or ParC, together with plasmid-mediated quinolone resistance determinants such as Qnr, AAC(6')-Ib-cr, and QepA. The actual state of ESBL-producing E. coli in hospitalized patients has been carefully investigated in many countries, while that in healthy people still remains uncertain, although high fecal carriage rates of ESBL producers in healthy people have been reported especially in Asian and South American countries. The issues regarding the ESBL producers have become very complicated and chaotic due to rapid increase of both ESBL variants and plasmids mediating ESBL genes, together with the emergence of various "epidemic strains" or "international clones" of E. coli and Klebsiella pneumoniae harboring transferable-plasmids carrying multiple antimicrobial resistance genes. Thus, the current state of ESBL producers outside hospital settings was overviewed together with the relation among those recovered from livestock, foods, pets, environments and wildlife from the viewpoint of molecular epidemiology. This mini review may contribute to better understanding about ESBL producers among people who are not familiar with the antimicrobial resistance (AMR) threatening rising globally.

IncI1 Plasmid Associated with blaCTX-M-2 Transmission in ESBL-Producing Escherichia coli Isolated from Healthy Thoroughbred Racehorse, Japan

“…The IncI1 plasmid was distributed to nearly all ESBLEC isolates and only the IncI1 plasmid was capable of transferring to transconjugants in this work. The dissemination of ESBL genes is reportedly mediated by the IncI1 plasmid [21]. E. coli was also reported to maintain the IncI1 plasmid without antibiotic selection pressure [22].…”

Wastewater as a Probable Environmental Reservoir of Extended-Spectrum-β-Lactamase Genes: Detection of Chimeric β-Lactamases CTX-M-64 and CTX-M-123

“…There is growing concern that E. coli isolates producing CTX-M enzymes, particularly CTX-M-15 and CTX-M-14, have also been frequently detected in companion animals, food-producing animals and their meat, and environmental samples in many countries (7)(8)(9)(10)(11). Furthermore, a high prevalence of CTX-M-27 producers among companion animals and a relatively high incidence of CTX-M-55, an Ala77Val variant from CTX-M-15 among raw chicken meat in Japan, have been documented in our own recent studies (10,11).…”

Occurrence and Antibiogram of Extended-Spectrum Cephalosporin- and Cephamycin-Resistant Escherichia coli in Asymptomatic University Students

“…36 Elsewhere, the occurrence of faecal ESBL-P E. coli was reported to be 0.1-69.3% among healthy individuals. [17][18][19] It is worth to note that Chukwunwejim et al used double disc synergy test method and detected 20 (7.3%) ESBL-P E. coli strains among 63 E. coli isolates from stool specimens of 273 asymptomatic students in NAU located in Anambra State, southeastern Nigeria. 13 The variation in the results of the studies may reflect the differences in the number of samples analyzed and usage of ESCs and other antibacterial agents in the various study areas.…”

“…5,14,15 Evidences support zoonotic transmission of ESC/FOX-resistant/ ESBL-P E. coli from humans to animals and vice versa. 16 In the available literature, there are numerous studies [17][18][19] on the occurrence and antibiogram of ESC-/ FOX-resistant and ESBL-/AmpC-P E. coli in hospitalized (in-and out-) patients and the community, including Nigeria. [20][21][22][23] However, reports on the colonization of healthy asymptomatic individuals by these organisms are rather scanty.…”

“…[20][21][22][23] However, reports on the colonization of healthy asymptomatic individuals by these organisms are rather scanty. [17][18][19] Studies which assessed the occurrence of ESC-resistant/ESBL-/AmpC-P E. coli in asymptomatic healthy university students included that of Kader et al in Saudi Arabia, 24 Chirindze et al in Mozambique, 25 Li et al in China 26 and Lonchel et al in Cameroun. 27 Recently, Chukwunwejim et al screened asymptomatic students in Nnamdi Azikiwe University (NAU) located in Anambra State, Southeast Nigeria and reported 7.3% ESBL-P E. coli occurrence.…”