Sorbitol-fermenting (SF) Escherichia coli O157:H- strains have emerged as important pathogens and... more Sorbitol-fermenting (SF) Escherichia coli O157:H- strains have emerged as important pathogens and have been associated with a higher incidence of progression to hemolytic–uremic syndrome (HUS) than non-sorbitol fermenting (NSF) E. coli O157:H7. The present study was carried out to determine the prevalence of SF E. coli O157:H- and NSF E. coli O157:H7 strains in retail beef products in Mansoura, Egypt. The contamination rates with rfbEO157-positive E. coli O157 strains were 26.7% (8/30), 10% (3/30) and 3.7% (1/27) in ground beef, beef burger, and fresh beef samples, respectively with an overall mean of 13.8% (12/87) among all meat products tested. SF E. coli O157:H- were the most dominant among the isolated O157 strains. Of the fifteen O157 strains isolated, 11 (73.3%) were SF E. coli O157:H-, while the remaining 4 (26.7%) were NSF E. coli O157:H7. The 11 SF O157H- strains were genetically positive for sfpA gene. Restriction fragment length polymorphism (RFLP) analysis for fliC gene demonstrated a similar pattern for both SF and NSF O157 isolates. PCR assays verified the existence of stx1 gene in 7 (46.7%) and stx2 gene in 13 (86.7%) of the 15 O157 strains isolated. Unexpectedly, two of the 15 O157 strains isolated were negative for Shiga toxin genes. The eae gene was identified in all of the 15 O157 strains except in one NSF O157:H7 strain. EHEC-hlyA gene was detected in 14 (93.3%) of the 15 O157 isolates, nonetheless only 11 strains showed enterohemolytic phenotype on blood agar. A combination of the four virulence genes, stx1, stx2, eae and EHEC-hlyA were detected in 7 (46.7%) strains, while six (40%) strains were positive for stx2, eae and hlyA genes. This is the first record for isolation of E. coli O157: H- in Egypt as well as in the African continent.
Cronobacter sakazakii is an opportunistic foodborne pathogen predominantly in neonates with repor... more Cronobacter sakazakii is an opportunistic foodborne pathogen predominantly in neonates with reported incidences in adults especially immunocompromised and the elderly. The current study was carried out to determine the prevalence of these organisms on meat products sold at Mansoura city, Egypt; besides its ability to compete with E. coli O157:H7 and Salmonella on their media. Suspected colonies were phenotypically-identified using API 20E system, additional biochemical tests, besides production of yellow-pigmented colonies; and genotypically-identified using species-specific PCR assays to detect the gene responsible for a-glucosidase activity, 16S rRNA gene and internal transcriber spacer sequence between 16S and 23S rRNA. Out of the 93 tested isolates, 14 isolates were confirmed as C. sakazakii with contamination rates of 16% (8/50) and 15% (6/40) of ground beef and beef burger samples, respectively and overall contamination rate of 15.6% (14/90) of all tested samples. The isolates were distributed among 7 different biogroups. These results added new epidemiological evidence about the widespread occurrence of these pathogens on tested meat products and such occurrence is an indicator for potential contamination with pathogens and so a health risk for consumers. Furthermore, C. sakazakii is an important competitor to E. coli O157:H7 and Salmonella on their selective media.
The prevalence of diarrheagenic E. coli in childhood diarrhea and the role of contaminated food p... more The prevalence of diarrheagenic E. coli in childhood diarrhea and the role of contaminated food products in disease transmission in Colombia are largely unknown. The aim of this study is to identify E. coli pathotypes, including E. coli O157:H7, from 108 stool samples from children with acute diarrhea, 38 meat samples and 38 vegetable samples. Multiplex PCR and Bax Dupont systems were used for E. coli pathotype detection. Eighteen (9.8%) E. coli diarrheagenic pathotypes were detected among all clinical and food product samples tested. Four different pathotypes were identified from clinical samples, including enteroaggregative E. coli, enterotoxigenic E. coli, shiga-toxin producing E. coli, and enteropathogenic E. coli. Food product samples were positive for enteroaggregative and shiga-toxin producing E. coli, suggesting that meat and vegetables may be involved in transmission of these E. coli pathotypes in the community. Most E. coli strains identified belong to the phylogenetic groups A and B1, known to be associated with intestinal rather than extraintestinal E. coli clones. Our data is the first molecular E. coli report that confirms the presence of E. coli pathotypes circulating in Colombia among children with diarrhea and food products for human consumption. Implementation of multiplex PCR technology in Latin America and other countries with limited resources may provide an important epidemiological tool for the surveillance of E. coli pathotypes from clinical isolates as well as from water and food product samples.
Sorbitol-fermenting (SF) Escherichia coli O157:H-strains have emerged as important pathogens and ... more Sorbitol-fermenting (SF) Escherichia coli O157:H-strains have emerged as important pathogens and have been associated with a higher incidence of progression to hemolytic-uremic syndrome (HUS) than non-sorbitol fermenting (NSF) E. coli O157:H7. The present study was carried out to determine the prevalence of SF E. coli O157:H-and NSF E. coli O157:H7 strains in retail beef products in Mansoura, Egypt. The contamination rates with rfbE O157 -positive E. coli O157 strains were 26.7% (8/30), 10% (3/30) and 3.7% (1/27) in ground beef, beef burger, and fresh beef samples, respectively with an overall mean of 13.8% (12/87) among all meat products tested. SF E. coli O157:H-were the most dominant among the isolated O157 strains. Of the fifteen O157 strains isolated, 11 (73.3%) were SF E. coli O157:H-, while the remaining 4 (26.7%) were NSF E. coli O157:H7. The 11 SF O157H-strains were genetically positive for sfpA gene. Restriction fragment length polymorphism (RFLP) analysis for fliC gene demonstrated a similar pattern for both SF and NSF O157 isolates. PCR assays verified the existence of stx1 gene in 7 (46.7%) and stx2 gene in 13 (86.7%) of the 15 O157 strains isolated. Unexpectedly, two of the 15 O157 strains isolated were negative for Shiga toxin genes. The eae gene was identified in all of the 15 O157 strains except in one NSF O157:H7 strain. EHEC-hlyA gene was detected in 14 (93.3%) of the 15 O157 isolates, nonetheless only 11 strains showed enterohemolytic phenotype on blood agar. A combination of the four virulence genes, stx1, stx2, eae and EHEC-hlyA were detected in 7 (46.7%) strains, while six (40%) strains were positive for stx2, eae and hlyA genes. This is the first record for isolation of E. coli O157: H-in Egypt as well as in the African continent.
This study determined the prevalence, serotypes and virulence genes distribution of non-O157 Shig... more This study determined the prevalence, serotypes and virulence genes distribution of non-O157 Shiga toxin-producing Escherichia coli in meat products collected from butchers shops and supermarkets in Mansoura city, Egypt. We have characterized 18 non-O157 STEC strains among the identified 100 E. coli isolates recovered from the examined 87 meat product samples. The prevalence of non-O157 STEC strains in fresh beef, ground beef and beef burger samples were 11.1% (3/27), 16.7% (5/30), and 33.3% (10/ 30), respectively. The eighteen non-O157 STEC isolated strains were serotyped into seven (38.9%) O111:H8, six (33.3%) O26:H11, two (11.1%) O111:He, and one (5.56%) for each of O55:H7, O126:H5 and O128:H2. PCR assays for different virulence genes showed that nine (50%), eleven (61.1%), and nine (50%) strains carry stx1, stx2, and eae genes, respectively. The distribution of shiga toxin genes among the isolated strains indicated that seven (38.9%) strains harbored stx1 only, nine (50%) strains harbored stx2 only, and two (11.1%) strains harbored both stx1 and stx2. The eae gene was present in association with five (27.8%), three (16.7%), and one (5.6%) strains that harbored stx1 only, stx2 only, and both stx1 and stx2, respectively. This study concluded that the examined meat products, particularly beef burger, consumed in Egypt are considerably contaminated with a variety of non-O157 STEC serotypes, and hence consumption of such products may constitute a potential health risk for consumers.
Sorbitol-fermenting (SF) Escherichia coli O157:H- strains have emerged as important pathogens and... more Sorbitol-fermenting (SF) Escherichia coli O157:H- strains have emerged as important pathogens and have been associated with a higher incidence of progression to hemolytic–uremic syndrome (HUS) than non-sorbitol fermenting (NSF) E. coli O157:H7. The present study was carried out to determine the prevalence of SF E. coli O157:H- and NSF E. coli O157:H7 strains in retail beef products in Mansoura, Egypt. The contamination rates with rfbEO157-positive E. coli O157 strains were 26.7% (8/30), 10% (3/30) and 3.7% (1/27) in ground beef, beef burger, and fresh beef samples, respectively with an overall mean of 13.8% (12/87) among all meat products tested. SF E. coli O157:H- were the most dominant among the isolated O157 strains. Of the fifteen O157 strains isolated, 11 (73.3%) were SF E. coli O157:H-, while the remaining 4 (26.7%) were NSF E. coli O157:H7. The 11 SF O157H- strains were genetically positive for sfpA gene. Restriction fragment length polymorphism (RFLP) analysis for fliC gene demonstrated a similar pattern for both SF and NSF O157 isolates. PCR assays verified the existence of stx1 gene in 7 (46.7%) and stx2 gene in 13 (86.7%) of the 15 O157 strains isolated. Unexpectedly, two of the 15 O157 strains isolated were negative for Shiga toxin genes. The eae gene was identified in all of the 15 O157 strains except in one NSF O157:H7 strain. EHEC-hlyA gene was detected in 14 (93.3%) of the 15 O157 isolates, nonetheless only 11 strains showed enterohemolytic phenotype on blood agar. A combination of the four virulence genes, stx1, stx2, eae and EHEC-hlyA were detected in 7 (46.7%) strains, while six (40%) strains were positive for stx2, eae and hlyA genes. This is the first record for isolation of E. coli O157: H- in Egypt as well as in the African continent.
Cronobacter sakazakii is an opportunistic foodborne pathogen predominantly in neonates with repor... more Cronobacter sakazakii is an opportunistic foodborne pathogen predominantly in neonates with reported incidences in adults especially immunocompromised and the elderly. The current study was carried out to determine the prevalence of these organisms on meat products sold at Mansoura city, Egypt; besides its ability to compete with E. coli O157:H7 and Salmonella on their media. Suspected colonies were phenotypically-identified using API 20E system, additional biochemical tests, besides production of yellow-pigmented colonies; and genotypically-identified using species-specific PCR assays to detect the gene responsible for a-glucosidase activity, 16S rRNA gene and internal transcriber spacer sequence between 16S and 23S rRNA. Out of the 93 tested isolates, 14 isolates were confirmed as C. sakazakii with contamination rates of 16% (8/50) and 15% (6/40) of ground beef and beef burger samples, respectively and overall contamination rate of 15.6% (14/90) of all tested samples. The isolates were distributed among 7 different biogroups. These results added new epidemiological evidence about the widespread occurrence of these pathogens on tested meat products and such occurrence is an indicator for potential contamination with pathogens and so a health risk for consumers. Furthermore, C. sakazakii is an important competitor to E. coli O157:H7 and Salmonella on their selective media.
The prevalence of diarrheagenic E. coli in childhood diarrhea and the role of contaminated food p... more The prevalence of diarrheagenic E. coli in childhood diarrhea and the role of contaminated food products in disease transmission in Colombia are largely unknown. The aim of this study is to identify E. coli pathotypes, including E. coli O157:H7, from 108 stool samples from children with acute diarrhea, 38 meat samples and 38 vegetable samples. Multiplex PCR and Bax Dupont systems were used for E. coli pathotype detection. Eighteen (9.8%) E. coli diarrheagenic pathotypes were detected among all clinical and food product samples tested. Four different pathotypes were identified from clinical samples, including enteroaggregative E. coli, enterotoxigenic E. coli, shiga-toxin producing E. coli, and enteropathogenic E. coli. Food product samples were positive for enteroaggregative and shiga-toxin producing E. coli, suggesting that meat and vegetables may be involved in transmission of these E. coli pathotypes in the community. Most E. coli strains identified belong to the phylogenetic groups A and B1, known to be associated with intestinal rather than extraintestinal E. coli clones. Our data is the first molecular E. coli report that confirms the presence of E. coli pathotypes circulating in Colombia among children with diarrhea and food products for human consumption. Implementation of multiplex PCR technology in Latin America and other countries with limited resources may provide an important epidemiological tool for the surveillance of E. coli pathotypes from clinical isolates as well as from water and food product samples.
Sorbitol-fermenting (SF) Escherichia coli O157:H-strains have emerged as important pathogens and ... more Sorbitol-fermenting (SF) Escherichia coli O157:H-strains have emerged as important pathogens and have been associated with a higher incidence of progression to hemolytic-uremic syndrome (HUS) than non-sorbitol fermenting (NSF) E. coli O157:H7. The present study was carried out to determine the prevalence of SF E. coli O157:H-and NSF E. coli O157:H7 strains in retail beef products in Mansoura, Egypt. The contamination rates with rfbE O157 -positive E. coli O157 strains were 26.7% (8/30), 10% (3/30) and 3.7% (1/27) in ground beef, beef burger, and fresh beef samples, respectively with an overall mean of 13.8% (12/87) among all meat products tested. SF E. coli O157:H-were the most dominant among the isolated O157 strains. Of the fifteen O157 strains isolated, 11 (73.3%) were SF E. coli O157:H-, while the remaining 4 (26.7%) were NSF E. coli O157:H7. The 11 SF O157H-strains were genetically positive for sfpA gene. Restriction fragment length polymorphism (RFLP) analysis for fliC gene demonstrated a similar pattern for both SF and NSF O157 isolates. PCR assays verified the existence of stx1 gene in 7 (46.7%) and stx2 gene in 13 (86.7%) of the 15 O157 strains isolated. Unexpectedly, two of the 15 O157 strains isolated were negative for Shiga toxin genes. The eae gene was identified in all of the 15 O157 strains except in one NSF O157:H7 strain. EHEC-hlyA gene was detected in 14 (93.3%) of the 15 O157 isolates, nonetheless only 11 strains showed enterohemolytic phenotype on blood agar. A combination of the four virulence genes, stx1, stx2, eae and EHEC-hlyA were detected in 7 (46.7%) strains, while six (40%) strains were positive for stx2, eae and hlyA genes. This is the first record for isolation of E. coli O157: H-in Egypt as well as in the African continent.
This study determined the prevalence, serotypes and virulence genes distribution of non-O157 Shig... more This study determined the prevalence, serotypes and virulence genes distribution of non-O157 Shiga toxin-producing Escherichia coli in meat products collected from butchers shops and supermarkets in Mansoura city, Egypt. We have characterized 18 non-O157 STEC strains among the identified 100 E. coli isolates recovered from the examined 87 meat product samples. The prevalence of non-O157 STEC strains in fresh beef, ground beef and beef burger samples were 11.1% (3/27), 16.7% (5/30), and 33.3% (10/ 30), respectively. The eighteen non-O157 STEC isolated strains were serotyped into seven (38.9%) O111:H8, six (33.3%) O26:H11, two (11.1%) O111:He, and one (5.56%) for each of O55:H7, O126:H5 and O128:H2. PCR assays for different virulence genes showed that nine (50%), eleven (61.1%), and nine (50%) strains carry stx1, stx2, and eae genes, respectively. The distribution of shiga toxin genes among the isolated strains indicated that seven (38.9%) strains harbored stx1 only, nine (50%) strains harbored stx2 only, and two (11.1%) strains harbored both stx1 and stx2. The eae gene was present in association with five (27.8%), three (16.7%), and one (5.6%) strains that harbored stx1 only, stx2 only, and both stx1 and stx2, respectively. This study concluded that the examined meat products, particularly beef burger, consumed in Egypt are considerably contaminated with a variety of non-O157 STEC serotypes, and hence consumption of such products may constitute a potential health risk for consumers.
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Papers by Mahmoud Mahros
associated with a higher incidence of progression to hemolytic–uremic syndrome (HUS) than non-sorbitol
fermenting (NSF) E. coli O157:H7. The present study was carried out to determine the prevalence of SF E. coli
O157:H- and NSF E. coli O157:H7 strains in retail beef products in Mansoura, Egypt. The contamination rates
with rfbEO157-positive E. coli O157 strains were 26.7% (8/30), 10% (3/30) and 3.7% (1/27) in ground beef, beef
burger, and fresh beef samples, respectively with an overall mean of 13.8% (12/87) among all meat products
tested. SF E. coli O157:H- were the most dominant among the isolated O157 strains. Of the fifteen O157 strains
isolated, 11 (73.3%) were SF E. coli O157:H-, while the remaining 4 (26.7%) were NSF E. coli O157:H7. The 11 SF
O157H- strains were genetically positive for sfpA gene. Restriction fragment length polymorphism (RFLP)
analysis for fliC gene demonstrated a similar pattern for both SF and NSF O157 isolates. PCR assays verified
the existence of stx1 gene in 7 (46.7%) and stx2 gene in 13 (86.7%) of the 15 O157 strains isolated. Unexpectedly,
two of the 15 O157 strains isolated were negative for Shiga toxin genes. The eae gene was identified in all of the
15 O157 strains except in one NSF O157:H7 strain. EHEC-hlyA gene was detected in 14 (93.3%) of the 15 O157
isolates, nonetheless only 11 strains showed enterohemolytic phenotype on blood agar. A combination of the
four virulence genes, stx1, stx2, eae and EHEC-hlyA were detected in 7 (46.7%) strains, while six (40%) strains
were positive for stx2, eae and hlyA genes. This is the first record for isolation of E. coli O157: H- in Egypt as
well as in the African continent.
incidences in adults especially immunocompromised and the elderly. The current study was carried out
to determine the prevalence of these organisms on meat products sold at Mansoura city, Egypt; besides
its ability to compete with E. coli O157:H7 and Salmonella on their media. Suspected colonies were
phenotypically-identified using API 20E system, additional biochemical tests, besides production of
yellow-pigmented colonies; and genotypically-identified using species-specific PCR assays to detect the
gene responsible for a-glucosidase activity, 16S rRNA gene and internal transcriber spacer sequence
between 16S and 23S rRNA. Out of the 93 tested isolates, 14 isolates were confirmed as C. sakazakii with
contamination rates of 16% (8/50) and 15% (6/40) of ground beef and beef burger samples, respectively
and overall contamination rate of 15.6% (14/90) of all tested samples. The isolates were distributed
among 7 different biogroups. These results added new epidemiological evidence about the widespread
occurrence of these pathogens on tested meat products and such occurrence is an indicator for potential
contamination with pathogens and so a health risk for consumers. Furthermore, C. sakazakii is an
important competitor to E. coli O157:H7 and Salmonella on their selective media.
associated with a higher incidence of progression to hemolytic–uremic syndrome (HUS) than non-sorbitol
fermenting (NSF) E. coli O157:H7. The present study was carried out to determine the prevalence of SF E. coli
O157:H- and NSF E. coli O157:H7 strains in retail beef products in Mansoura, Egypt. The contamination rates
with rfbEO157-positive E. coli O157 strains were 26.7% (8/30), 10% (3/30) and 3.7% (1/27) in ground beef, beef
burger, and fresh beef samples, respectively with an overall mean of 13.8% (12/87) among all meat products
tested. SF E. coli O157:H- were the most dominant among the isolated O157 strains. Of the fifteen O157 strains
isolated, 11 (73.3%) were SF E. coli O157:H-, while the remaining 4 (26.7%) were NSF E. coli O157:H7. The 11 SF
O157H- strains were genetically positive for sfpA gene. Restriction fragment length polymorphism (RFLP)
analysis for fliC gene demonstrated a similar pattern for both SF and NSF O157 isolates. PCR assays verified
the existence of stx1 gene in 7 (46.7%) and stx2 gene in 13 (86.7%) of the 15 O157 strains isolated. Unexpectedly,
two of the 15 O157 strains isolated were negative for Shiga toxin genes. The eae gene was identified in all of the
15 O157 strains except in one NSF O157:H7 strain. EHEC-hlyA gene was detected in 14 (93.3%) of the 15 O157
isolates, nonetheless only 11 strains showed enterohemolytic phenotype on blood agar. A combination of the
four virulence genes, stx1, stx2, eae and EHEC-hlyA were detected in 7 (46.7%) strains, while six (40%) strains
were positive for stx2, eae and hlyA genes. This is the first record for isolation of E. coli O157: H- in Egypt as
well as in the African continent.
incidences in adults especially immunocompromised and the elderly. The current study was carried out
to determine the prevalence of these organisms on meat products sold at Mansoura city, Egypt; besides
its ability to compete with E. coli O157:H7 and Salmonella on their media. Suspected colonies were
phenotypically-identified using API 20E system, additional biochemical tests, besides production of
yellow-pigmented colonies; and genotypically-identified using species-specific PCR assays to detect the
gene responsible for a-glucosidase activity, 16S rRNA gene and internal transcriber spacer sequence
between 16S and 23S rRNA. Out of the 93 tested isolates, 14 isolates were confirmed as C. sakazakii with
contamination rates of 16% (8/50) and 15% (6/40) of ground beef and beef burger samples, respectively
and overall contamination rate of 15.6% (14/90) of all tested samples. The isolates were distributed
among 7 different biogroups. These results added new epidemiological evidence about the widespread
occurrence of these pathogens on tested meat products and such occurrence is an indicator for potential
contamination with pathogens and so a health risk for consumers. Furthermore, C. sakazakii is an
important competitor to E. coli O157:H7 and Salmonella on their selective media.