Prevalence and Antimicrobial Susceptibility of Escherichia coli O157:H7 in Vegetables Sold in the Amathole District, Eastern Cape Province of South Africa

2008 ◽  
Vol 71 (4) ◽  
pp. 816-819 ◽  
Author(s):  
B. O. ABONG'O ◽  
M. N. B. MOMBA ◽  
J. N. MWAMBAKANA

Fresh vegetables have been implicated in outbreaks of Escherichia coli O157:H7 in most parts of the world. Microbiological quality of vegetables used as recipes for salads is very crucial. Residents of the Amathole District in the Eastern Cape Province of South Africa consume salads frequently, although the microbial quality of recipe vegetables is questionable. The present study investigated the prevalence and antimicrobial susceptibility of E. coli O157:H7 isolated from selected vegetables sold within the Amathole District. One hundred eighty samples of the vegetables were analyzed. Strains of E. coli O157:H7 were isolated by enrichment culture and by immunomagnetic separation and identified by conventional and molecular techniques. In three settlements in this district, the mean counts of presumptive E. coli O157 for the vegetables ranged between 9 × 103 and 1.6 × 106 CFU/g for Fort Beaufort, 1.6 × 103 and 1.6 × 105 CFU/g for Mdantsane, and 1.3 × 103 and 4.1 × 104 CFU/g for Alice. Four (10.3%) of 39 vegetable samples were confirmed to carry E. coli O157:H7. Four representative E. coli O157:H7 isolates from these vegetables were susceptible to at least one of the eight antimicrobial agents tested against them. Even though the prevalence of E. coli O157:H7 was low and those isolated were susceptible to most of the antimicrobials, there remains a need for E. coli O157:H7 surveillance in vegetables used in salad recipes in urban and rural areas of South Africa.

2020 ◽  
Vol 13 (7) ◽  
pp. 1363-1371
Author(s):  
Philisani Ncoko ◽  
Ishmael Festus Jaja ◽  
James Wabwire Oguttu

Background and Aim: Abattoir processes from skinning, evisceration, to chilling usually lead to meat contamination by foodborne pathogens. Hence, continual microbial surveillance of slaughter carcasses by veterinary public health officials is key to preventing contamination and outbreak of meat-related foodborne diseases. This study was conducted to determine the Enterobacteriaceae count and aerobic plate count (APC) and to detect Escherichia coli and Salmonella spp. in meat and water from selected slaughter facilities. Materials and Methods: Retrospective data (n=100) collected in 2017 by the Provincial Veterinary Department of the Eastern Cape Province from abattoirs and prospective survey data of meat (n=50) collected in 2018 from abattoirs in the Eastern Cape Province were utilized in this study. APC and Enterobacteriaceae were enumerated from the samples. In addition, Salmonella and E. coli were isolated from samples using selective media. Results: The APC in both retrospective and prospective studies for all samples ranged between 2 and 4.50 log CFU/cm2; similar counts of 2-4.00 log CFU/cm2 were recorded for Enterobacteriaceae. No significant difference (p>0.05) for APC and Enterobacteriaceae count across all meat types was noted. Salmonella and E. coli were detected in 50% of beef. E. coli was not detected from mutton, but Salmonella was found in 66.7%. Moreover, 91.7% of the water samples had E. coli, but none had Salmonella. Conclusion: The levels of Enterobacteriaceae and APC observed in meat satisfy regulatory conditions outlined by the Department of Agriculture, Forestry and Fisheries, South Africa and show that meat produced from these abattoirs is of acceptable microbial quality. However, the quality of water used in the abattoirs does not meet the requirements set by the government, and contributes to contamination of meat produced in the abattoirs under study. Therefore, we recommend that sources of water be continuously investigated to eliminate or reduce the risk of contamination of meat processed in the abattoirs.


2009 ◽  
Vol 72 (10) ◽  
pp. 2038-2045 ◽  
Author(s):  
YAGUANG LUO ◽  
QIANG HE ◽  
JAMES L. McEVOY ◽  
WILLIAM S. CONWAY

This study investigated the effect of storage temperature and time on the survival and growth of Escherichia coli O157:H7, the growth of indigenous microorganisms, and the changes in product quality of packaged baby spinach. Commercial packages of spinach within 2 days of processing were cut open at one end, sprayed with fine mists of E. coli O157:H7 inoculum, resealed, and then stored at 1, 5, 8, and 12°C for 12 days until their labeled best-if-used-by dates. Microbial enumeration and product quality evaluation were conducted on day(s) 0, 3, 6, 9, and 12 postinoculation. Spinach held at 12°C supported significant (P < 0.001) E. coli O157:H7 growth, with a 1.0-log CFU/g increase within 3 days postinoculation, which was followed by additional growth during continued storage. E. coli O157:H7 grew slowly when held at 8°C, with a significant (P < 0.01) level of growth reached after 6 days of storage. However, on products held at 1 and 5°C, E. coli O157:H7 populations declined significantly (P < 0.01 and P < 0.001, respectively) within 3 days of storage. Aerobic mesophilic bacteria, psychrotrophic bacteria, and yeast and mold populations increased significantly at all storage temperatures, with more growth on products held at elevated temperatures. Product quality scores remained high within the first 6 days of storage, with a sharp decline noted on samples held at 12°C on day 9. Results suggest that E. coli O157:H7 can grow significantly on commercially packaged spinach held at 8°C or above before significant product quality deterioration occurs.


2008 ◽  
Vol 71 (10) ◽  
pp. 2082-2086 ◽  
Author(s):  
LUCIANO BENEDUCE ◽  
GIUSEPPE SPANO ◽  
ARI Q. NABI ◽  
FRANCESCO LAMACCHIA ◽  
SALVATORE MASSA ◽  
...  

In this study, 100 raw meat samples were collected from 15 local Moroccan butcheries in five different areas of the city of Rabat during a period of 4 months. Overall, 7 of 15 butcheries from three areas of the city yielded strains of Escherichia coli O157. Single isolates from 9 (9%) of 100 raw meat samples were biochemically and serologically confirmed as E. coli O157. Using molecular techniques, two strains were positive for the Shiga toxin, with two additional strains containing an attaching-effacing gene. All potentially virulent serotypes isolated from these meat samples showed distinct pulsed-field gel electrophoresis profiles. Based on antibiotic susceptibility testing, more than 70% of the isolates were resistant to ampicillin and clavulanic acid–amoxicillin. Moreover, one strain was resistant to more than three antibiotics. Our study represents the first survey of E. coli O157 and related serotypes in raw meat products in Morocco.


2018 ◽  
Vol 81 (8) ◽  
pp. 1227-1235 ◽  
Author(s):  
MINGMING GUO ◽  
TONY Z. JIN ◽  
JOSHUA B. GURTLER ◽  
XUETONG FAN ◽  
MADHAV P. YADAV

ABSTRACT Antimicrobial washing (AW), antimicrobial coating (AC), and a combination of washing followed by coating (AW+AC) were evaluated for their ability to inactivate artificially inoculated foodborne pathogens and native microbiota on strawberries stored at 4°C. Strawberries were inoculated with a six-strain composite of Escherichia coli O157:H7 and Salmonella; treated by AW, AC, or AW+AC; and stored at 4°C for 3 weeks. The washing solution contained 90 ppm of peracetic acid, and the coating solution consisted of chitosan (1%, w/v), allyl isothiocyanate (1%, v/v), and corn-bio fiber gum (5%, w/v). The effectiveness of the antimicrobial treatments against E. coli O157:H7 and Salmonella pathogens and native microflora on strawberries and their impact on fruit quality (appearance, weight loss, color, and firmness) were determined. By the end of storage, pathogen populations on strawberries were 2.5 (AW+AC), 2.9 (AC), 3.8 (AW), and 4.2 log CFU for the positive (untreated) control. AW+AC treatments also inactivated the greatest population of native microflora, followed by the AC treatment alone. AW+AC treatments showed additional antimicrobial effectiveness against these two pathogens and native microflora. Both AW+AC and AC treatments preserved the color, texture, and appearance of strawberries throughout storage. The coating treatments (AW+AC and AC alone) further reduced the loss of moisture throughout storage. The AW treatment was the least effective in reducing populations of pathogens and native microflora and in maintaining the quality of strawberries throughout storage. This study demonstrates a method to improve the microbiological safety, shelf life, and quality of strawberries.


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