Phenotypic and genotypic characteristics of shiga toxin-producing Escherichia coli strains isolated from children in São Paulo, Brazil

Guth, Beatriz E. C.; Ramos, Sônia R. T. S.; Cerqueira, Aloysio de Mello Figueiredo; Andrade, João Ramos da Costa; Gomes, Tânia A. T.

doi:10.1590/s0074-02762002000800003

Cited by 35 publications

(25 citation statements)

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“…The great majority of these non-O157 serotypes are among those most frequently isolated in many different countries (2,9,14,23). In São Paulo, low rates of occurrence O111 STEC strains had previously been reported (16). Although outbreaks of HUS caused by O111 strains had been described (4,5,8), the O111 STEC strains identified so far in our settings were all associated with sporadic cases of diarrhea in young children.…”

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confidence: 44%

“…Thus, considering the serotypes and virulence profiles, these STEC strains can be classified as EHEC, and it would not be surprising if some of them had been associated with more severe diseases. We can only speculate about this possibility, because (16,17), we observed that this reaction also distinguished O111 STEC strains from the other STEC serotypes identified. The inability to decarboxylate lysine and the lack of sucrose fermentation by the majority of the O111:HNM strains showed that these strains can be misidentified presumptively as EIEC or as Shigella.…”

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confidence: 91%

“…Other putative virulence factors include the enteroaggregative E. coli heat-stable enterotoxin (EAST-1), encoded by astA (25), particularly in O157:H7 and O26:H11 strains and in some other STEC serotypes. In Brazil, the studies conducted so far that searched for STEC in human diarrheal disease have investigated a limited number of strains and have described the isolation of a few non-O157 STEC strains (7,12,16). The isolation of O157:H7 strains from patients with bloody diarrhea as well as one with HUS related to O26:H11 infection was only recently reported in Brazil (15,19).…”

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Virulence Properties and Characteristics of Shiga Toxin-Producing Escherichia coli in São Paulo, Brazil, from 1976 through 1999

et al. 2004

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Twenty-nine Shiga toxin-producingShiga toxin-producing Escherichia coli (STEC) can cause a broad spectrum of human illness ranging from uncomplicated diarrhea to hemorrhagic colitis (HC) and hemolytic-uremic syndrome (HUS) (14). E. coli O157:H7 is by far the most important STEC serotype in the world and has been associated with numerous outbreaks and many sporadic cases of HC and HUS (20). However, infections with other non-O157 STEC serotypes have been increasingly reported in many countries (2,3,22). Currently more than 100 different non-O157 STEC serotypes have been isolated from human infections. Unlike with O157:H7, outbreaks caused by non-O157 STEC have rarely been reported, and these strains have been more frequently associated with sporadic cases of diarrhea, HC, and HUS. Moreover, in many countries, non-O157 strains are more commonly isolated from patients with diarrhea or HUS than are O157 STEC strains (3, 5, 23). The major virulence trait of these bacteria is the production of one or more Stx types (Stx1, Stx2, or Stx2 variants) (20). Additional factors, produced mainly by strains in straight association with human disease and collectively referred to as enterohemorrhagic E. coli (EHEC), include intimin and enterohemolysin (1,20). Other putative virulence factors include the enteroaggregative E. coli heat-stable enterotoxin (EAST-1), encoded by astA (25), particularly in O157:H7 and O26:H11 strains and in some other STEC serotypes. In Brazil, the studies conducted so far that searched for STEC in human diarrheal disease have investigated a limited number of strains and have described the isolation of a few non-O157 STEC strains (7,12,16). The isolation of O157:H7 strains from patients with bloody diarrhea as well as one with HUS related to O26:H11 infection was only recently reported in Brazil (15,19).The purpose of this study was to search for STEC in a collection of 2,607 E. coli isolates, most of them belonging to important serogroups increasingly associated with HUS and HC in other countries. The main virulence factors, biotypes, and susceptibility to antimicrobial agents of the STEC strains identified were characterized.The E. coli strains studied belonged to the collection of Instituto Adolfo Lutz, a Central Public Health Laboratory in São Paulo, Brazil, and national center for E. coli serotyping, and were isolated between 1976 and 1999, mainly from children (0 to 5 years old) with diarrhea (2,549 strains); the remaining 58 E. coli strains were isolated from immunocompromised adult patients with diarrhea (mainly human immunodeficiency virus positive) over the same period. Each strain was derived from one patient. Except for diarrhea, no other information regarding the clinical aspects of the patients were available. None of the strains belonging to the enteropathogenic E. coli (EPEC) serogroups carried the EAF sequence (EPEC adherence factor) as assayed by hybridization assays with a specific DNA probe (13). The remaining strains outside the EPEC serogroups did not belong to the enteroinvasive ...

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confidence: 91%

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Virulence Properties and Characteristics of Shiga Toxin-Producing Escherichia coli in São Paulo, Brazil, from 1976 through 1999

et al. 2004

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“…However, currently several other distinct serotypes of E. coli other than the O157 are recognized as shiga toxin E. coli (STEC) associated with human diseases. These serotypes including E. coli O111:H8, O26:H11, O103:H2 have been reported in some parts of developed countries (Guth et al, 2000(Guth et al, , 2003). The association of various E. coli serotypes with disease of varying severity in humans and with sporadic disease or outbreaks has led to the proposal that verotoxin producing E. coli be classified into five seropathotypes, with seropathotype A comprising of O157:H7 and O157:NM, the serotypes considered to be most virulent.…”

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confidence: 93%

Virulence factors and antibiotic susceptibility among verotoxic non O157: H7 Escherichia coli isolates obtained from water and wastewater samples in Cape Town, South Africa.

Doughari¹,

Ndakidemi²,

Human³

et al. 2011

Afr. J. Biotechnol.

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Forty eight samples (30 wastewater and 18 river water) were collected between July and November, 2010, from different sources in Cape Town, South Africa in order to characterize verotoxic non O157: H7 Escherichia coli strains. Samples (1 ml) were inoculated into MacConkey broth (MB, 9 ml) and incubated at 37°C for 24 h, after which a loopful of the MB was then spread onto Eosin Methylene Blue (EMB) and further incubated for 24 h at 37°C in order to isolate E. coli. The identification of isolates was done using standard biochemical procedures; and confirmed serologically using E. coli polyvalent antisera (Bioweb, SA). Isolates were also characterized for virulence factors such as verotoxin, haemolysin, gelatinase, extended spectrum beta lactamases (ESBLs), cell surface hydrophobicity and bacterial serum resistance, as well as susceptibility (using disc diffusion method) to stem bark extracts of Curtisia dentata. Results showed the presence of different serotypes of E. coli (69 isolates in all) including 026: H11, 055, O111: NM, O126, O44, O124, O96:H9, O103:H2, O145: NM and O145:H2. Over 60% of the isolates exhibited serum resistance, haemolysin and gelatinase production, 81% exhibited cell surface hydrophobicity and over 52% produced ESBLs. Results also showed that while 60% of the isolates showed various levels of resistance to different antibiotics [ampicillin (10 µg), cefuroxime, cephalexin, ceftazidime and tetracycline (30 µg in each case) (multidrug resistance index (MDRI) values 4.20 to 5.60%)], only 28% were resistant to ethanol stem bark extracts of C. dentata (MIC, 70 to 150 mg/ml). The presence of pathogenic verotoxic antibiotic resistant E. coli in these water sources is a threat to water quality and food security and C. dentata has a potential for sourcing novel antibiotic substances for chemotherapy against these resistant pathogenic strains of E. coli.

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“…Nonmotile (HNM) strains were investigated for the flagellar gene (fliC) by restriction fragment length polymorphism-PCR (15). The presence of cytotoxic activity on Vero and HeLa cells, the production of enterohemolysin, and adhesion to HEp-2 cells were determined as previously described (8). Colony hybridization assays with specific DNA probes related to ETEC, EIEC, and EAEC pathotypes were performed under stringent conditions (26).…”

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Distinct Pathotypes of O113 Escherichia coli Strains Isolated from Humans and Animals in Brazil

et al. 2007

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Phenotypic and genotypic characteristics of shiga toxin-producing Escherichia coli strains isolated from children in São Paulo, Brazil

Cited by 35 publications

References 26 publications

Virulence Properties and Characteristics of Shiga Toxin-Producing Escherichia coli in São Paulo, Brazil, from 1976 through 1999

Virulence Properties and Characteristics of Shiga Toxin-Producing Escherichia coli in São Paulo, Brazil, from 1976 through 1999

Virulence factors and antibiotic susceptibility among verotoxic non O157: H7 Escherichia coli isolates obtained from water and wastewater samples in Cape Town, South Africa.

Distinct Pathotypes of O113 Escherichia coli Strains Isolated from Humans and Animals in Brazil

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