scholarly journals Water used to moisten vegetables is a source of Escherichia coli and protozoan parasite contamination at markets in Hanoi, Vietnam

2014 ◽  
Vol 12 (4) ◽  
pp. 896-900 ◽  
Author(s):  
Nguyen Thuy Tram ◽  
Anders Dalsgaard
Keyword(s):  
Escherichia Coli ◽  
Food Safety ◽  
Water Samples ◽  
Protozoan Parasite ◽  
Protozoan Parasites ◽  
Safety Hazards ◽  
E Coli ◽  
Cryptosporidium Spp ◽  
Median Concentration ◽  
Cryptosporidium Oocysts

The study was done to assess the level of fecal (Escherichia coli) and protozoan parasite (Cryptosporidium spp. and Giardia spp.) contamination in water used by traders to moisten vegetables at markets in Hanoi, Vietnam. A total of 200 splashing water samples from markets located within eight districts were analyzed for E. coli and Cryptosporidium spp. and Giardia spp. (oo)cysts. Giardia cysts were found in 17 splashing water samples and Cryptosporidium oocysts in nine samples, with median values of 20 cysts ml−1 and 10 oocysts ml−1, respectively. E. coli was found with a median concentration of 636 cfu ml−1 and its occurrence was negatively correlated with the numbers of protozoan parasites. The splashing water was kept in buckets that were rarely cleaned and often used for handwashing. The finding of these pathogens in splashing water is likely to represent real food safety hazards.

Presence of Cryptosporidium Oocysts in Fresh Vegetables

1996 ◽  
Vol 59 (2) ◽  
pp. 202-203 ◽  
Author(s):  
RAFAEL MONGE ◽  
MISAEL CHINCHILLA
Keyword(s):  
Escherichia Coli ◽  
Linear Correlation ◽  
Rainy Season ◽  
Fecal Coliforms ◽  
Contamination Rate ◽  
E Coli ◽  
Cryptosporidium Spp ◽  
Fresh Vegetables ◽  
Cryptosporidium Oocysts ◽  
Positive Linear Correlation

In Costa Rica, a total of 640 samples from eight different vegetables used for raw consumption were analyzed for the presence of Cryptosporidium spp. oocysts, fecal coliforms, and Escherichia coli. Cryptosporidium spp. oocysts were found in 5.0% (4 samples) of cilantro leaves, 8.7% (7 samples) of cilantro roots and 2.5% (2 samples) of lettuce samples. A 1.2% contamination rate was detected in samples of other vegetables (radish, tomato, cucumbers and carrot). Oocysts of this parasite were absent from cabbage. A greater percentage of positive samples was found during the rainy season, and only in cilantro roots and lettuce was a positive linear correlation (P < 0.05) established between the presence of Cryptosporidium spp. oocysts and fecal coliforms and E. coli.

scholarly journals Detection of Escherichia coli O157:H7 and Shiga toxin 2a gene in pork, pig feces, and clean water at Jagalan slaughterhouse in Surakarta, Central Java Province, Indonesia

2019 ◽  
Vol 12 (10) ◽  
pp. 1584-1590
Author(s):  
Maria Kristiani Epi Goma ◽  
Alvita Indraswari ◽  
Aris Haryanto ◽  
Dyah Ayu Widiasih
Keyword(s):  
Escherichia Coli ◽  
Food Safety ◽  
Shiga Toxin ◽  
Water Samples ◽  
Animal Origin ◽  
Clean Water ◽  
Escherichia Coli O157 ◽  
Fecal Samples ◽  
E Coli ◽  
Pork Samples

Background and Aim: The feasibility assessment of food products on the market becomes one of the milestones of food safety. The quality of food safety of animal origin especially pork need to get attention and more real action from the parties related and concerned. Since pork is also a source of transmission for the contagion of foodborne disease so that the study of the existence of several agents in the pork and its products become the benchmark of safety level. This study aimed to isolate, identify, and detect the Shiga toxin 2a (stx2a) gene from Escherichia coli O157:H7 in pork, pig feces, and clean water in the Jagalan slaughterhouse. Materials and Methods: A total of 70 samples consisting of 32 pork samples, 32 pig fecal samples, and 6 clean water samples were used to isolate and identify E. coli O157:H7 and the stx2a gene. Isolation and identification of E. coli O157:H7 were performed using culture on eosin methylene blue agar and Sorbitol-MacConkey agar media and confirmed molecularly with polymerase chain reaction to amplify the target genes rfbE (317 bp) and fliC (381 bp). The isolates, which were identified as E. coli O157:H7, were investigated for the stx2a gene (553 bp). Results: The results of this study show that of the total collected samples, E. coli O157:H7 was 28.6% in Jagalan slaughterhouse and consisted of 25% of pork samples, 31.25% of pig fecal samples, and 33.3% of clean water samples. The isolates that were identified to be E. coli O157:H7 mostly contained the stx2a gene, which was equal to 75%, and consisted of seven isolates from pork samples, seven isolates from fecal samples, and one isolate from clean water samples. Conclusion: E. coli O157:H7 was found in 28.6% of pork, pig feces, and clean water in Jagalan slaughterhouse and 75% of identified E. coli O157:H7 contained the stx2a gene.

Contamination of Tomatoes with Coliforms and Escherichia coli on Farms and in Markets of Northwest Nigeria

2015 ◽  
Vol 78 (1) ◽  
pp. 57-64 ◽  
Author(s):  
KENNETH C. SHENGE ◽  
CLEMENT M. Z. WHONG ◽  
LYDIA L. YAKUBU ◽  
RAPHAEL A. OMOLEHIN ◽  
J. MARK ERBAUGH ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Food Safety ◽  
Irrigation Water ◽  
Water Samples ◽  
Microbial Contamination ◽  
Tomato Fruit ◽  
Safety Practices ◽  
E Coli ◽  
Field Samples ◽  
Fruit Samples

Although recent reports indicated that produce contamination with foodborne pathogens is widespread in Nigeria, the sources and magnitude of microbial contamination of fruits and vegetables on farms and in markets have not been thoroughly identified. To ascertain possible pathways of contamination, the frequency and magnitude of coliform and Escherichia coli contamination of tomatoes produced in northwest Nigeria was assessed on farms and in markets. Eight hundred twenty-six tomato fruit samples and 36 irrigation water samples were collected and assessed for fecal indicator organisms. In addition, the awareness and use of food safety practices by tomato farmers and marketers were determined. Median concentration of coliforms on all field- and market-sourced tomato fruit samples, as well as in irrigation water sources, in Kaduna, Kano, and Katsina states exceeded 1,000 most probable number (MPN) per g. Median E. coli counts from 73 (17%) of 420 field samples and 231 (57%) of 406 market tomato fruit samples exceeded 100 MPN/g. Median E. coli concentrations on tomato fruits were higher (P < 0.01) in the rainy season (2.45 Log MPN/g), when irrigation was not practiced than in the dry (1.10 Log MPN/g) and early dry (0.92 Log MPN/g) seasons. Eighteen (50%) of 36 irrigation water samples had E. coli counts higher than 126 MPN/100 ml. Median E. coli contamination on market tomato fruit samples (2.66 Log MPN/g) were higher (P < 0.001) than those from tomatoes collected on farms (0.92 Log MPN/g). Farmers and marketers were generally unaware of the relationship between food safety practices and microbial contamination on fresh produce. Good agricultural practices pertaining to food safety on farms and in local markets were seldom used. Adoption of food safety practices on-farm, during transport, and during marketing could improve the microbial quality of tomatoes available to the public in this region of the world.

An Improved Membrane Filtration Method for Enumeration of Faecal Coliforms and E. Coli by a Fluorogenic β-Glucuronidase Assay

1993 ◽  
Vol 27 (3-4) ◽  
pp. 267-270 ◽  
Author(s):  
M. T. Augoustinos ◽  
N. A. Grabow ◽  
B. Genthe ◽  
R. Kfir
Keyword(s):  
Escherichia Coli ◽  
Water Samples ◽  
Membrane Filtration ◽  
Faecal Coliforms ◽  
Environmental Waters ◽  
Filtration Method ◽  
E Coli ◽  
Wide Range ◽  
Pure Cultures ◽  
Glucuronidase Assay

A fluorogenic β-glucuronidase assay comprising membrane filtration followed by selective enumeration on m-FC agar at 44.5°C and further confirmation using tlie 4-metliylumbelliferyl-β-D-glucuronide (MUG) containing medium was evaluated for the detection of Escherichia coli in water. A total of 200 typical blue and non-typical blue colonies were isolated from sea and fresh water samples using initial selective enumeration on m-FC agar. Pure cultures of the selected colonies were further tested using the MUG assay and identified using the API 20E method. Of the colonies tested which were shown to be positive using the MUG assay 99.4% were Escherichia coli. The results of this study indicate the combination of the m-FC method followed by the MUG assay to be highly efficient for the selection and confirmation of E. coli from a wide range of environmental waters.

scholarly journals Prevalence and Characterization of Extended-Spectrum β-Lactamase-Producing Antibiotic-Resistant Escherichia coli and Klebsiella pneumoniae in Ready-to-Eat Street Foods

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 850
Author(s):  
Shobha Giri ◽  
Vaishnavi Kudva ◽  
Kalidas Shetty ◽  
Veena Shetty
Keyword(s):  
Escherichia Coli ◽  
Food Safety ◽  
Klebsiella Pneumoniae ◽  
Rural Areas ◽  
Significant Risk ◽  
Microbiological Quality ◽  
Resistant Bacteria ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Extended Spectrum

As the global urban populations increase with rapid migration from rural areas, ready-to-eat (RTE) street foods are posing food safety challenges where street foods are prepared with less structured food safety guidelines in small and roadside outlets. The increased presence of extended-spectrum-β-lactamase (ESBL) producing bacteria in street foods is a significant risk for human health because of its epidemiological significance. Escherichia coli and Klebsiella pneumoniae have become important and dangerous foodborne pathogens globally for their relevance to antibiotic resistance. The present study was undertaken to evaluate the potential burden of antibiotic-resistant E. coli and K. pneumoniae contaminating RTE street foods and to assess the microbiological quality of foods in a typical emerging and growing urban suburb of India where RTE street foods are rapidly establishing with public health implications. A total of 100 RTE food samples were collected of which, 22.88% were E. coli and 27.12% K. pneumoniae. The prevalence of ESBL-producing E. coli and K. pneumoniae was 25.42%, isolated mostly from chutneys, salads, paani puri, and chicken. Antimicrobial resistance was observed towards cefepime (72.9%), imipenem (55.9%), cefotaxime (52.5%), and meropenem (16.9%) with 86.44% of the isolates with MAR index above 0.22. Among β-lactamase encoding genes, blaTEM (40.68%) was the most prevalent followed by blaCTX (32.20%) and blaSHV (10.17%). blaNDM gene was detected in 20.34% of the isolates. This study indicated that contaminated RTE street foods present health risks to consumers and there is a high potential of transferring multi-drug-resistant bacteria from foods to humans and from person to person as pathogens or as commensal residents of the human gut leading to challenges for subsequent therapeutic treatments.

Introduction to the Food Safety Concerns of Verotoxin-Producing Escherichia coli

2003 ◽  
Vol 228 (4) ◽  
pp. 331-332 ◽  
Author(s):  
Hussein S. Hussein ◽  
Stanley T. Omaye
Keyword(s):  
Escherichia Coli ◽  
Food Safety ◽  
Safety Concern ◽  
Critical Evaluation ◽  
The United States ◽  
Global Perspective ◽  
E Coli ◽  
The Past ◽  
Food Borne Pathogens ◽  
Food Borne

Verotoxin-producing Escherichia coli (VTEC) have emerged in the past two decades as food-borne pathogens that can cause major outbreaks of human illnesses worldwide. The number of outbreaks has increased in recent years due to changes in food production and processing systems, eating habits, microbial adaptation, and methods of VTEC transmission. The human illnesses range from mild diarrhea to hemolytic uremic syndrome (HUS) that can lead to death. The VTEC outbreaks have been attributed to O157:H7 and non-O157:H7 serotypes of E. coli. These E. coli serotypes include motile (e.g., O26:H11 and O104:H21) and nonmotile (e.g., O111:H–,0145:H–, and O157:H–) strains. In the United States, E. coli O157:H7 has been the major cause of VTEC outbreaks. Worldwide, however, non-O157:H7 VTEC (e.g., members of the 026, O103, O111, O118, O145, and O166 serogroups) have caused approximately 30% of the HUS cases in the past decade. Because large numbers of the VTEC outbreaks have been attributed to consumption of ruminant products (e.g., ground beef), cattle and sheep are considered reservoirs of these food-borne pathogens. Because of the food safety concern of VTEC, a global perspective on this problem is addressed (Exp Biol Med Vol. 228, No. 4). The first objective was to evaluate the known non-O157:H7 VTEC strains and the limitations associated with their detection and characterization. The second objective was to identify the VTEC serotypes associated with outbreaks of human illnesses and to provide critical evaluation of their virulence. The third objective was to determine the rumen effect on survival of E. coli O157:H7 as a VTEC model. The fourth objective was to explore the role of intimins in promoting attaching and effacing lesions in humans. Finally, the ability of VTEC to cause persistent infections in cattle was evaluated.

scholarly journals Induction of Viable but Nonculturable Escherichia coli O157:H7 in the Phyllosphere of Lettuce: a Food Safety Risk Factor

2011 ◽  
Vol 77 (23) ◽  
pp. 8295-8302 ◽  
Author(s):  
Laura-Dorina Dinu ◽  
Susan Bach
Keyword(s):  
Escherichia Coli ◽  
Food Safety ◽  
Low Temperature ◽  
Cell Density ◽  
Prolonged Storage ◽  
Potential Hazard ◽  
Vbnc State ◽  
Viable But Nonculturable ◽  
Content Type ◽  
E Coli

ABSTRACTEscherichia coliO157:H7 continues to be an important human pathogen and has been increasingly linked to food-borne illness associated with fresh produce, particularly leafy greens. The aim of this work was to investigate the fate ofE. coliO157:H7 on the phyllosphere of lettuce under low temperature and to evaluate the potential hazard of viable but nonculturable (VBNC) cells induced under such stressful conditions. First, we studied the survival of six bacterial strains following prolonged storage in water at low temperature (4°C) and selected two strains with different nonculturable responses for the construction ofE. coliO157:H7 Tn7gfptransformants in order to quantitatively assess the occurrence of human pathogens on the plant surface. Under a suboptimal growth temperature (16°C), bothE. coliO157:H7 strains maintained culturability on lettuce leaves, but under more stressful conditions (8°C), the bacterial populations evolved toward the VBNC state. The strain-dependent nonculturable response was more evident in the experiments with different inoculum doses (109and 106E. coliO157:H7 bacteria per g of leaf) when strain BRMSID 188 lost culturability after 15 days and strain ATCC 43895 lost culturability within 7 days, regardless of the inoculum dose. However, the number of cells entering the VBNC state in high-cell-density inoculum (approximately 55%) was lower than in low-cell-density inoculum (approximately 70%). We recorded the presence of verotoxin for 3 days in samples that contained a VBNC population of 4 to 5 log10cells but did not detect culturable cells. These findings indicate thatE. coliO157:H7 VBNC cells are induced on lettuce plants, and this may have implications regarding food safety.

scholarly journals Detection of antimicrobial resistance genes of carbapenem-resistant Enterobacteriaceae in Escherichia coli isolated from the water supply of smallholder dairy farms in Saraburi and Maha Sarakham, Thailand

2020 ◽  
Vol 6 (1) ◽  
pp. 1-5
Author(s):  
Natapol Pumipuntu ◽  
Sangkom Pumipuntu
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Water Samples ◽  
Dairy Farms ◽  
Drug Resistant ◽  
E Coli ◽  
Carbapenem Resistant ◽  
Carbapenem Resistant Enterobacteriaceae ◽  
Smallholder Dairy Farms

Background and Aim: The problem of antimicrobial resistance of bacteria in both humans and animals is an important public health concern globally, which is likely to increase, including in Thailand, where carbapenem-resistant Enterobacteriaceae (CRE), such as Escherichia coli, are of particular concern. They are pathogens found in the gastrointestinal tract of humans and other animals as well as in the environment. They may cause opportunistic infection and are often resistant to antibiotics in various fields especially in animal husbandry, such as pets or livestock farms. This study aimed to investigate the occurrence of carbapenem-resistant E. coli from water samples of smallholder dairy farms in Saraburi and Maha Sarakham, Thailand. Materials and Methods: Sixty-four water samples were collected from 32 dairy farms in Kaeng Khoi district, Muak Lek district, and Wang Muang district of Saraburi Province, and Kantharawichai district and Mueang district of Maha Sarakham Province, Thailand. All samples were cultured and isolated for E. coli by biochemical tests. All E. coli isolates were tested for drug susceptibility using imipenem, meropenem, and drug resistance genes of carbapenemases such as blaNDM, blaIMP, and blaOXA48 of drug-resistant E. coli isolates detected by polymerase chain reaction (PCR) technique. Results: A total of 182 E. coli isolates were found (140 and 42 isolates from Saraburi and Maha Sarakham, respectively). Drug sensitivity tests found that two isolates of E. coli from water in Kaeng Khoi were resistant to imipenem; therefore, the incidence of E. coli resistance to carbapenem was 1.43% of Saraburi Province. On the other hand, there was no incidence of drug-resistant E. coli in Maha Sarakham. In addition, the detection of the drug-resistant gene of E. coli in both isolates by PCR showed the expression of blaNDM. Conclusion: This study reports E. coli resistance to antimicrobial drugs on livestock farms. It can be considered to be the first report of E. coli CRE detection in a dairy farm at Saraburi, which should be the subject of further extended study.

Season and Species: Two Possible Hurdles for Reducing the Food Safety Risk of Escherichia coli O157 Contamination of Leafy Vegetables

2019 ◽  
Vol 82 (2) ◽  
pp. 247-255 ◽  
Author(s):  
KARIN SÖDERQVIST ◽  
ANNA KARIN ROSBERG ◽  
SOFIA BOQVIST ◽  
BEATRIX ALSANIUS ◽  
LARS MOGREN ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Food Safety ◽  
Shelf Life ◽  
Spinacia Oleracea ◽  
Growing Season ◽  
Leafy Vegetables ◽  
Production Chain ◽  
Safety Risk ◽  
E Coli ◽  
Food Safety Risk

ABSTRACT The food safety risk of Shiga toxin–producing Escherichia coli (STEC) infection per serving of leafy vegetables was investigated using a quantitative microbial risk assessment (QMRA) approach. The estimated level of E. coli O157 contamination was based on observed numbers of Enterobacteriaceae and E. coli on leafy vegetables grown and processed in southern Sweden from 2014 to 2016. Samples were collected before harvest, after washing, and at the end of shelf life. The observed counts were combined with data on the ratio of E. coli to E. coli O157 taken from earlier studies to estimate the probability of illness. The risks of STEC infection associated with species, either spinach (Spinacia oleracea) or rocket (Diplotaxis tenuifolia), growing season (spring or autumn), and washing (washed or not washed) were then evaluated. The results indicated that leafy vegetable species and growing season could be possible hurdles for reducing the food safety risk of STEC infection. At harvest, the probability of infection was 87% lower when consuming rocket compared with spinach and 90% lower when consuming leafy vegetables grown in spring compared with autumn. These relative risk reductions remained consistent even with other serving sizes and dose-response models. The lowest risk of STEC infection was associated with leafy vegetables early in the production chain, i.e., before harvest, while the risk increased during storage and processing. Consequently, the highest risk was observed when leafy vegetables were consumed at the end of shelf life. Washing had no effect on the food safety risk of STEC infection in this study. To improve the quality of QMRA, there is a need for additional data on the relationship between indicator organisms that can be easily enumerated (e.g., E. coli and Enterobacteriaceae) and E. coli strains that can cause STEC infection (e.g., E. coli O157) but are difficult to identify in food samples such as leafy vegetables.

scholarly journals Cryptosporidium spp. Infections in Livestock and Wild Animals in Azerbaijan Territory

2020 ◽  
Vol 2 (1) ◽  
pp. 44
Author(s):  
Simuzer Mamedova ◽  
Panagiotis Karanis
Keyword(s):  
Staining Method ◽  
Current Knowledge ◽  
Protozoan Parasite ◽  
Structural Features ◽  
Cryptosporidium Spp ◽  
Faecal Samples ◽  
Cryptosporidium Oocysts ◽  
Stool Specimens ◽  
Intracellular Protozoan Parasite ◽  
Acid Fast Staining

Cryptosporidium is an intracellular protozoan parasite and is increasingly gaining attention as a human and an animal pathogen, mainly due to its predominant involvement in worldwide waterborne outbreaks. This paper reviews the current knowledge and understanding of Cryptosporidium spp. in terrestrial and aquatic animals in Azerbaijan. The diagnosis of cryptosporidiosis relies on the identification of oocysts in faecal samples released by the infected host. Stool specimens were processed using the modified acid-fast staining method (Ziehl-Neelsen) and microscopically examined for Cryptosporidium oocysts. Thirteen species of Cryptosporidium (C. fragile, C. ducismarci, C. serpentis, C. varani, C. baileyi, C. meleagridis, C. muris, C. parvum, C. ubiquitum, C. andersoni, C. bovis, C. hominis, C. suis) from amphibians, reptiles, birds and mammals have been identified as a result of studies conducted between 1987 and 2019 on the structural features of Cryptosporidium oocysts in Azerbaijan territory.

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