O serogroup specific real time PCR assays for the detection and identification of nine clinically relevant non-O157 STECs

Lin, Andrew; Sultan, Omar; Lau, Henry K.; Wong, Evelyn; Hartman, Gary L.; Lauzon, Carol R.

doi:10.1016/j.fm.2010.10.007

Cited by 45 publications

(25 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, other serotypes, such as E. coli O26:H11, E. coli O103:H2, E. coli O145:H28, and E. coli O111:H8, have also been implicated in outbreaks (10).…”

mentioning

confidence: 99%

Behavior of Different Shiga Toxin-Producing Escherichia coli Serotypes in Various Experimentally Contaminated Raw-Milk Cheeses

Miszczycha

Perrin

Ganet

et al. 2013

Appl Environ Microbiol

View full text Add to dashboard Cite

e Shiga toxin-producing Escherichia coli (STEC) is an important cause of food-borne illness. The public health implication of the presence of STEC in dairy products remains unclear. Knowledge of STEC behavior in cheeses would help to evaluate the human health risk. The aim of our study was to observe the growth and survival of experimentally inoculated STEC strains in raw-milk cheeses manufactured and ripened according to five technological schemes: blue-type cheese, uncooked pressed cheese with long ripening and with short ripening steps, cooked cheese, and lactic cheese. Cheeses were contaminated with different STEC serotypes (O157:H7, O26:H11, O103:H2, and O145:H28) at the milk preparation stage. STEC growth and survival were monitored on selective media during the entire manufacturing process. STEC grew (2 to 3 log 10 CFU · g ؊1 ) in blue-type cheese and the two uncooked pressed cheeses during the first 24 h of cheese making. Then, STEC levels progressively decreased in cheeses that were ripened for more than 6 months. In cooked cheese and in lactic cheese with a long acidic coagulation step (pH < 4.5), STEC did not grow. Their levels decreased after the cooking step in the cooked cheese and after the coagulation step in the lactic cheese, but STEC was still detectable at the end of ripening and storage. A serotype effect was found: in all cheeses studied, serotype O157:H7 grew less strongly and was less persistent than the others serotypes. This study improves knowledge of the behavior of different STEC serotypes in various raw-milk cheeses.

show abstract

“…However, other serotypes, such as E. coli O26:H11, E. coli O103:H2, E. coli O145:H28, and E. coli O111:H8, have also been implicated in outbreaks (10).…”

mentioning

confidence: 99%

Behavior of Different Shiga Toxin-Producing Escherichia coli Serotypes in Various Experimentally Contaminated Raw-Milk Cheeses

Miszczycha

Perrin

Ganet

et al. 2013

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…Also, unreliable IMS results have been reported previously when STEC cell numbers were low (20). Besides wzx, other serogroup-specific genes in the O-antigen gene cluster, such as wzy (encoding O-antigen polymerase) and wbd (encoding O-antigen transferase), have been used as targets to design qPCR assays for the specific detection of various STEC serogroups (13,30,39). Although reported to be rapid, specific, and sensitive, qPCR assays require a sophisticated thermal cycling instrument with real-time fluorescence monitoring, limiting their wide applicability.…”

mentioning

confidence: 99%

Rapid and Specific Detection of Escherichia coli Serogroups O26, O45, O103, O111, O121, O145, and O157 in Ground Beef, Beef Trim, and Produce by Loop-Mediated Isothermal Amplification

Wang

Jiang

Yang

et al. 2012

Appl Environ Microbiol

View full text Add to dashboard Cite

ABSTRACTEscherichia coliO157 and six additional serogroups of Shiga toxin-producingE. coli(STEC) (O26, O45, O103, O111, O121, and O145) account for the majority of STEC infections in the United States. In this study, O serogroup-specific genes (wzxorwzy) were used to design loop-mediated isothermal amplification (LAMP) assays for the rapid and specific detection of these leading STEC serogroups. The assays were evaluated in pure culture and spiked food samples (ground beef, beef trim, lettuce, and spinach) and compared with real-time quantitative PCR (qPCR). No false-positive or false-negative results were observed among 120 bacterial strains used to evaluate assay specificity. The limits of detection of various STEC strains belonging to these target serogroups were approximately 1 to 20 CFU/reaction mixture in pure culture and 103to 104CFU/g in spiked food samples, which were comparable to those of qPCR. Standard curves generated suggested good linear relationships between STEC cell numbers and LAMP turbidity signals. In various beef and produce samples spiked with two low levels (1 to 2 and 10 to 20 CFU/25 g) of respective STEC strains, the LAMP assays consistently achieved accurate detection after 6 to 8 h of enrichment. In conclusion, these newly developed LAMP assays may facilitate rapid and reliable detection of the seven major STEC serogroups in ground beef, beef trim, and produce during routine sample testing.

show abstract

“…In addition, Soomro et al [25] reported that the prevalence of E. coli in milk and dairy products was 51.7% and 57%, respectively. Representative 13 E. coli isolates were sero-grouped as shown in Table ( [27]. STEC strains of these Oserogroups are considered as the world's main pathogenic strains implicated for public health hazards.…”

Section: Resultsmentioning

confidence: 99%

Detection of Shiga Toxin – Producing Escherichia coli in Raw and Pasteurized Milk

Ahmed¹,

Samer²

2017

Zagazig Veterinary Journal

View full text Add to dashboard Cite

One hundred random samples of raw buffalo and pasteurized cow milk (50, each) were collected from different localities of Sharkia Governorate for the detection of E. coli. The isolates were screened by PCR for virulence associated genes as well as antibiotic sensitivity test to determine the most effective antimicrobial agent. Furthermore, an experimental study was carried out to detect the influence of pasteurization and processing of kariesh cheese and yoghurt on E. coli O 111 :H 8 inoculated in milk with the concentration of 10 8 CFU/mL. The obtained results showed that the occurrence of E. coli in the examined raw buffalo and pasteurized cow milk samples were 66% and 30%, respectively. Serogrouping of E. coli isolates revealed that O128, O26 and O111 were recorded as the most frequent O-serogroups. The sensitivity test showed that E. coli isolates were more sensitive to gentamicin (79.2%), followed by ciprofloxacin (70.8%) and colistin (68.8%). However, the examined isolates were completely resistant to erythromycin (100%) followed by sulphamethazole-trimethoprim (79.2%). Molecular identification of virulence associated genes revealed stx1, stx2 and eaeA genes. The experimental study showed that milk pasteurization was more effective on E. coli O 111 :H 8 survival at refrigeration temperature compared with processed products such as kariesh cheese and yoghurt.

show abstract

O serogroup specific real time PCR assays for the detection and identification of nine clinically relevant non-O157 STECs

Cited by 45 publications

References 29 publications

Behavior of Different Shiga Toxin-Producing Escherichia coli Serotypes in Various Experimentally Contaminated Raw-Milk Cheeses

Behavior of Different Shiga Toxin-Producing Escherichia coli Serotypes in Various Experimentally Contaminated Raw-Milk Cheeses

Rapid and Specific Detection of Escherichia coli Serogroups O26, O45, O103, O111, O121, O145, and O157 in Ground Beef, Beef Trim, and Produce by Loop-Mediated Isothermal Amplification

Detection of Shiga Toxin – Producing Escherichia coli in Raw and Pasteurized Milk

Contact Info

Product

Resources

About