Enterotoxins, colonization factors, serotypes and antimicrobial resistance of enterotoxigenic Escherichia coli (ETEC) strains isolated from hospitalized children with diarrhea in Bolivia

Rodas, Claudia; Mamani, Rosalía; Blanco, Jorge; Blanco, Jesús E.; Wiklund, Gudrun; Svennerholm, Ann‐Mari; Sjöling, Åsa; Iñiguez, Volga

doi:10.1590/s1413-86702011000200007

Cited by 13 publications

(16 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, although ST and LT/ST ETEC strains were significantly more frequent in diarrhea cases in this study, they did not cause symptoms of greater severity than those seen with LT-only isolates, supporting the notion that LT-only ETEC strains may cause severe diarrhea. This finding is consistent with data from recent studies reporting an increased prevalence of LT ETEC strains causing severe symptoms (16,37). Analysis of the presence of putative virulence factors clyA, eatA, east-1, tibC, tia, and leoA in ETEC strains isolated from children with and without diarrhea did not reveal any association among these factors in ETEC and diarrhea.…”

Section: Discussionsupporting

confidence: 92%

“…However, variations in toxin profiles were observed from year to year. Different studies in Latin America have shown differences in the predominant toxin type; for instance, LT/ST ETEC strains were found to be most prevalent in Peru (19), ST-only ETEC strains in Brazil (20) and LT ETEC strains in Argentina (23), in Nicaragua (21), and in a previous report from Bolivia (16). A similar trend has been observed in Bangladesh, where different toxin profiles have predominated over the years (24)(25)(26).…”

Section: Discussionsupporting

confidence: 65%

“…In Bolivia, ETEC has been reported to be present in feces of around 8% of children aged Ͻ5 years hospitalized due to diarrhea (16,17; L. Gonzales, E. Joffre, R. Rivera, Å. Sjöling, A. M. Svennerholm, V. Iñiguez, submitted for publication). However, there is little knowledge of the molecular characteristics and virulence profiles of ETEC in Bolivia.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Molecular Characterization of Enterotoxigenic Escherichia coli Isolates Recovered from Children with Diarrhea during a 4-Year Period (2007 to 2010) in Bolivia

et al. 2013

Self Cite

View full text Add to dashboard Cite

bEnterotoxigenic Escherichia coli (ETEC) is an important cause of childhood diarrhea. This study aimed to characterize ETEC strains isolated from Bolivian children aged <5 years according to enterotoxin profile, colonization factors (CFs), suggested virulence genes, and severity of disease. A total of 299 ETEC isolates recovered from children with diarrhea and 55 ETEC isolates from children without diarrhea (controls) were isolated over a period of 4 years. Strains expressing heat-labile toxin (LT) or heat-stable toxin (ST) alone were about equally common and twice as common as ETEC producing both toxins (20%). ETEC strains expressing human ST (STh) were more common in children aged <2 years, while ETEC strains expressing LT plus STh (LT/STh) were more frequent in 2-to 5-year-old children. Severity of disease was not related to the toxin profile of the strains. CF-positive isolates were more frequently identified in diarrheal samples than in control samples (P ‫؍‬ 0.02). The most common CFs were CFA/I and CS14. CFA/I ETEC strains were more frequent in children aged <2 years than CS1؉CS3 isolates and CS14 isolates, which were more prevalent in 2-to 5-year-old children. The presence of suggested ETEC virulence genes (clyA, eatA, tia, tibC, leoA, and east-1) was not associated with disease. However, east-1 was associated with LT/STh strains (P < 0.001), eatA with STh strains (P < 0.001), and tia with LT/STh strains (P < 0.001). A minor seasonal peak of ETEC infections was identified in May during the cold-dry season and coincided with the peak of rotavirus infections; this pattern is unusual for ETEC and may be important for vaccination strategies in Bolivia.

show abstract

Section: Discussionsupporting

confidence: 92%

Section: Discussionsupporting

confidence: 65%

See 1 more Smart Citation

Molecular Characterization of Enterotoxigenic Escherichia coli Isolates Recovered from Children with Diarrhea during a 4-Year Period (2007 to 2010) in Bolivia

et al. 2013

Self Cite

View full text Add to dashboard Cite

show abstract

“…It is well known that the production of CFAs can be variable due to genetic defects in the genes required for expression (27) and the composition of bacterial growth media and growth conditions; this is particularly true for CS21, which requires unique growth conditions (36). A number of studies have reported that genotypic methods offer certain advantages over phenotypic methods (18,37). These studies suggest that there is increased sensitivity and specificity of CFA detection using molecular tools.…”

Section: Discussionmentioning

confidence: 99%

Pathogenicity and Phenotypic Characterization of Enterotoxigenic Escherichia coli Isolates from a Birth Cohort of Children in Rural Egypt

et al. 2014

Self Cite

View full text Add to dashboard Cite

c Enterotoxigenic Escherichia coli (ETEC) has consistently been the predominant bacterial cause of diarrhea in many birth cohort-and hospital-based studies conducted in Egypt. We evaluated the pathogenicity of ETEC isolates in a birth cohort of children living in a rural community in Egypt. Between 2004 and 2007, we enrolled and followed 348 children starting at birth until their second year of life. A stool sample and two rectal swabs were collected from children during twice-weekly visits when they presented with diarrhea and were collected every 2 weeks if no diarrhea was reported. From routine stool cultures, five E. colilike colonies were screened for ETEC enterotoxins using a GM1 enzyme-linked immunosorbent assay (ELISA). The isolates were screened against a panel of 12 colonization factor antigens (CFAs) by a dot blot assay. A nested case-control study evaluated the association between initial or repeat excretion of ETEC and the occurrences of diarrhea. The pathogenicity of ETEC was estimated in symptomatic children compared to that in asymptomatic controls. ETEC was significantly associated with diarrhea (crude odds ratio, 1.37; 95% confidence interval [CI], 1.24 to 1.52). The distribution of ETEC enterotoxins varied between the symptomatic children (44.2% heat-labile toxin [LT], 38.5% heat-stable toxin [ST], and 17.3% LT/ST) and asymptomatic children (55.5% LT, 34.6% ST, and 9.9% LT/ST) (P < 0.001). The CFAs CFA/I (n ‫؍‬ 61), CS3 (n ‫؍‬ 8), CS1 plus CS3 (n ‫؍‬ 24), CS2 plus CS3 (n ‫؍‬ 18), CS6 (n ‫؍‬ 45), CS5 plus CS6 (n ‫؍‬ 11), CS7 (n ‫؍‬ 25), and CS14 (n ‫؍‬ 32) were frequently detected in symptomatic children, while CS6 (n ‫؍‬ 66), CS12 (n ‫؍‬ 51), CFA/I (n ‫؍‬ 43), and CS14 (n ‫؍‬ 20) were detected at higher frequencies among asymptomatic children. While all toxin phenotypes were associated with diarrheal disease after the initial exposure, only ST and LT/ ST-expressing ETEC isolates (P < 0.0001) were associated with disease in repeat infections. The role of enterotoxins and pathogenicity during repeat ETEC infections appears to be variable and dependent on the coexpression of specific CFAs.

show abstract

“…Analysis of antibiotic resistance showed that 67% (n = 29/43) of the enterotoxigenic E. coli strains were resistant to one or several of the antimicrobial agents tested. The presence of colonization factors was associated with antibiotic resistance [6]. Cephalosporinase producing E. coli has recently been detected in meat and animals [7].…”

mentioning

confidence: 99%

Development of Antimicrobials against Escherichia coli - Environmental Microbiology meets Chemical Biotechnology

Lai¹

2012

J Pet Environ Biotechnol

View full text Add to dashboard Cite

Escherichia coli (E. coli) is the commonest infecting uropathogen with its incidence climbing from 50% to 60% of Urinary Tract Infections (UTIs). A recent report has demonstrated a diverse antimicrobial-resistant E. coli population distributed over various areas (nasal, oral, rectal, abdomen and hindquarter) of a companion animal's body, thereby suggesting potential transfer of resistant micro flora to human hosts during contact. Epidemiological patterns in UTIs show large inter-regional variability, and rates of bacterial resistance are continually changing due to different regional antibiotic treatment regime [1]. E. coli is also one of the most important causes of nosocomial infections. In hospitals, trimethoprim or nitrofurantoin is usually recommended for empirical treatment of uncomplicated cystitis whilst parenteral cephalosporins, aminoglycosides, quinolones and coamoxyclav are reserved for complicated UTIs. Bloodstream Infections (BSIs) are often treated with fluoroquinolones and β-lactams (mainly gentamicin, ciprofloxacin and third-generation cephalosporins). The antimicrobial susceptibility pattern of uropathogenic E. coli strains (isolated from urine specimens) was determined using 13 common antibiotics [2]. The rates of antibiotic resistance of bio film producing E. coli were found to be 100% for chloramphenicol and amoxyclav (amoxicillin and clavulanic acid), 86% for gentamicin and cefotaxime, 84% for ceftazidime, 83% for cotrimoxazole and piperacillin/ tazobactam, 75% for tetracycline, and 70% for amikacin. An ecological study investigating the correlation between the level of antimicrobial consumption and resistance, however, resistance to these compounds was reported with increasing frequency [3]. The dramatic rate increase in gentamicin resistance is of paramount concern. Neither ampicillin nor trimethoprim represent suitable empirical antimicrobials for UTI, and ciprofloxacin resistance renders it unsuitable empirical therapy for nosocomial UTIs. BSIs caused by 3GC-resistant E. coli are associated with excess mortality and prolonged hospital stay, adding to the suffering of patients and posing a considerable burden on healthcare costs [4]. Global efforts to reduce the consumption of broad-spectrum antimicrobial agents are hence warranted. Fortunately, E. coli -induced UTIs have remained extremely sensitive to nitrofurantoin and the resistance rate has not changed significantly over the last decade.Antimicrobial agent usage is common in animal agriculture for therapeutic and prophylactic purposes. Selective pressure exerted by these antimicrobials on soil bacteria could result in the selection of strains that are resistant due to chromosomal-or plasmid-derived genetic components [5]. Analysis of antibiotic resistance showed that 67% (n = 29/43) of the enterotoxigenic E. coli strains were resistant to one or several of the antimicrobial agents tested. The presence of colonization factors was associated with antibiotic resistance [6]. Cephalosporinase producing E. coli has recently been detected ...

show abstract

Enterotoxins, colonization factors, serotypes and antimicrobial resistance of enterotoxigenic Escherichia coli (ETEC) strains isolated from hospitalized children with diarrhea in Bolivia

Cited by 13 publications

References 22 publications

Molecular Characterization of Enterotoxigenic Escherichia coli Isolates Recovered from Children with Diarrhea during a 4-Year Period (2007 to 2010) in Bolivia

Molecular Characterization of Enterotoxigenic Escherichia coli Isolates Recovered from Children with Diarrhea during a 4-Year Period (2007 to 2010) in Bolivia

Pathogenicity and Phenotypic Characterization of Enterotoxigenic Escherichia coli Isolates from a Birth Cohort of Children in Rural Egypt

Development of Antimicrobials against Escherichia coli - Environmental Microbiology meets Chemical Biotechnology

Contact Info

Product

Resources

About