Isolation and serological identification of enteropathogenic Escherichia coli in pasteurized milk in Brazil

OBJECTIVE: To evaluate the microbiological quality of pasteurized milk commercialized in Rio de Janeiro, Brazil, and determine serologically enteropathogenic Escherichia coli (EPEC) strains in E. coli isolates obtained from milk samples. METHODS: Ninety samples of pasteurized milk -- types B and C -- of three different commercial brands, purchased in supermarkets and bakeries in Rio de Janeiro, were examined. The amount of total and fecal coliform bacteria was estimated using the Most Probable Number technique. Mesophilic, psychrotrophic, and thermoduric microorganism counts were determined by the Standard Plate Count technique. Isolation and identification of E. coli were carried out using conventional physiological tests. Commercial antisera were used for serological characterization of EPEC. RESULTS: The three milk brands analyzed revealed bacterial counts above the regulated values of the Brazilian government. It was found that among 208 strains of E. coli isolated, 46 (22.1%) were serologically classified as EPEC. The most common EPEC serogroup was O55 (15.2%). CONCLUSIONS: Though recent studies on virulence factors indicate that not all strains serologically classified as EPEC are able to attaching/effacing lesion, it is believed that the isolation of EPEC serogroups from pasteurized milk represent a potential risk for children, as well as an indicative of the presence of other enteropathogens.

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Escherichia coli O157:H7 in Drin Prevalence of Escherichia coli O157:H7 in Drink from Different Food Premises in Kota Samarahan Sarawak

Trends in Undergraduate Research ◽

10.33736/tur.1422.2019 ◽

2019 ◽

Vol 2 (2) ◽

pp. a13-19

Author(s):

ELEXSON NILLIAN ◽

AMIZA NUR ◽

DIYANA NUR ◽

AMIRAH ZAKIRAH ◽

GRACE BEBEY

Keyword(s):

Escherichia Coli ◽

Drinking Water ◽

Coliform Bacteria ◽

Most Probable Number ◽

Plain Water ◽

Escherichia Coli O157 ◽

Probable Number ◽

E Coli ◽

Preventive Actions ◽

Stx1 Gene

Contamination of drinks with E. coli O157:H7 served in food premises such as restaurants can cause haemorrhagic colitis and haemolytic uremic syndrome to humans. The presence or absence of faecal pathogen was demonstrated using coliform group as indicator microorganisms. Therefore, this study was conducted to detect the presence of E. coli O157:H7 in drinking water from food restaurant premise in Kota Samarahan and Kuching to ensure safe and potable drinking water is served to the consumer. A total of thirty (n=30) drink samples including six types of each of the samples are cold plain water, iced tea, iced milo, syrup and iced milk tea. Most Probable Number (MPN) procedure was used in this study to enumerate the MPN values of coliform bacteria in each drink collected. A total of 53.33% (16/30) of the drink samples showed positive E. coli detection. Then, the PCR assay showed 6.25% (one out of 16 isolates) samples were positive and carried stx1 gene produced by E. coli O157:H7 in iced milo sample types. This study showed the drinks collected from food premises was contaminated with faecal contamination, which was not safe to drink by the consumer. Therefore, preventive actions should be taken to prevent foodborne illness outbreak in future

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Comparison of the Compact Dry EC with the Most Probable Number Method (AOAC Official Method 966.24) for Enumeration of Escherichia coli and Coliform Bacteria in Raw Meats: Performance-Tested MethodSM 110402

Journal of AOAC International ◽

10.1093/jaoac/89.1.100 ◽

2006 ◽

Vol 89 (1) ◽

pp. 100-114 ◽

Cited By ~ 7

Author(s):

Hidemasa Kodaka ◽

Shingo Mizuochi ◽

Hajime Teramura ◽

Tadanobu Nirazuka ◽

David Goins ◽

...

Keyword(s):

Escherichia Coli ◽

Water Soluble ◽

Test Method ◽

Gelling Agent ◽

Coliform Bacteria ◽

Most Probable Number ◽

Official Method ◽

Probable Number ◽

E Coli ◽

Raw Meats

Abstract Compact Dry E. coli/Coliform Count (EC) is a ready-to-use test method for the enumeration of Escherichia coli and coliform bacteria in food. The plates are presterilized and contain culture medium and a cold water-soluble gelling agent. The medium should be rehydrated with 1 mL diluted sample inoculated onto the center of the self-diffusible medium, allowing the solution to diffuse by capillary action. The plate can be incubated at 35C for 2024 h and the colonies counted without any further working steps. The Compact Dry EC medium plates were validated as an analysis tool for determining colony-forming units (CFU) of E. coli and coliform bacteria from a variety of raw meats using 5 different types of raw meats. The performance tests were conducted at 35C. In all studies performed, no apparent differences were observed between the Compact Dry ECmethod and theAOAC Official Method 966.24 results. For the accuracy claim (n = 75), a correlation factor of r2 = 0.93 (E. coli) and r2 = 0.93 (coliform bacteria) could be assigned, as stated in the application for Performance-Tested MethodSM.

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Comparison of the SimPlate Coliform and Escherichia coli Test with Petrifilm, Three-Tube MPN, and VRBA + MUG Methods for Enumerating Coliforms and E. coli in Food

Journal of Food Protection ◽

10.4315/0362-028x-61.4.444 ◽

1998 ◽

Vol 61 (4) ◽

pp. 444-449 ◽

Cited By ~ 10

Author(s):

D. E. TOWNSEND ◽

R. L. IRVING ◽

A. NAQUI

Keyword(s):

Escherichia Coli ◽

Correlation Coefficients ◽

Raw Milk ◽

Food Samples ◽

Coliform Bacteria ◽

Most Probable Number ◽

Additional Food ◽

Suitable Alternative ◽

Probable Number ◽

E Coli

SimPlate for coliforms and Escherichia coli (CEc) is a new method for the detection and quantification of coliforms and E. coli in food. Internal validation of the method was carried out at IDEXX Laboratories (Westbrook, ME) with 180 food samples representing a variety of different food matrices and compared against three-tube MPN (most probable number), VRBA (violet red bile agar) + MUG, and Petrifilm (E. coli count) methods. SimPlate CEc was highly correlated with each of these methods for the quantification of coliform bacteria (r ≥ 0.90). An insignificant number of food samples were found to contain E. coli; therefore, no meaningful correlation data could be generated. Four hundred forty-four additional food samples were tested at five collaborating laboratories for the presence of coliforms and E. coli using SimPlate CEc and either VRBA + MUG or Petrifilm (E. coli count). Regression analysis of data from SimPlate for CEc versus Petrifilm E. coli count plates generated correlation coefficients (r) of at least 0.89 for total coliforms and at least 0.90 for generic E. coli. Correlation coefficients between SimPlate for CEc and VRBA + MUG data were at least 0.90 for coliforms and at least 0.86 for E. coli. SimPlate for CEc demonstrated better recovery of E. coli than Petrifilm when high populations of bacteria were present. E. coli was not detected in 20 of 50 (40%) raw milk samples tested by the Petrifilm method due to the presence of interfering coliform and noncoliform bacteria. It is concluded that SimPlate for CEc is a suitable alternative for determining numbers of coliform bacteria and E. coli in food.

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Evaluation of microbial quality and pathogenic potentiality of enterobacteria in poultry feeds

Journal of Bio-Science ◽

10.3329/jbs.v28i0.44711 ◽

2019 ◽

Vol 28 ◽

pp. 59-68

Author(s):

S Islam ◽

N Tanjila ◽

MF Begum

Keyword(s):

Escherichia Coli ◽

Morphological Characteristics ◽

Coliform Bacteria ◽

Poultry Feed ◽

Plate Count ◽

Test Results ◽

Poultry Feeds ◽

E Coli ◽

Aerobic Plate Count ◽

Feed Samples

The present investigation has been carried out to assess the microbial safety and pathogenic potentialities of enterobacteria in poultry feeds. From the results it was observed that total aerobic plate count of poultry feeds samples were recorded as 2.8 × 105 to 5.8 × 109 cfu/g and 100% samples contained ≥106 cfu/g while the highest mean of cfu was counted as log10 8.797/gm. Large number of coliforms were recorded in different poultry feed samples and the ranges of cfu were counted as 1.2 × 104 to 5.2 × 107/g while average 75% samples were contaminated with coliform bacteria with ≥104 cfu/g and the highest mean of cfu was counted as log10 6.103/g. The ranges of cfu of Escherichia coli were 1.03 × 102 to 1.09 × 105/g and 70% samples contained ≥102 cfu/g while the highest mean of cfu was counted as log10 4.493/gm. But the ranges of cfu of total Salmonella sp. were recorded as 1.02 × 101 to 5.25 × 104/g and 50% samples contained ≥102 cfu/g and the highest mean of cfu was counted as log10 3.665/g. Total 29 enterobacterial isolates were isolated from the feed by using selected media. On the basis of morphological characteristics and biochemical test results the isolates were identified as Salmonella sp., Shigella sp., Klebsiella sp., Citrobacter sp., Proteus sp., Enterobacter sp. and Escherichia coli. These isolates were tested on blood agar medium and only seven isolates showed positive β-hemolytic activity.In virulence efficacy test, only hemolytic positive isolates were ingested to chicken and observed that E. coli (SGE-1), Klebsiella sp. (SSE-6) and Salmonella sp. (JSS-9) isolates were highly toxic because the experimental chickens were died after 3 days of ingestion of the bacteria, two isolates showed loose motion symptom after 15 days while other isolates showed little sickness. All the selected isolates showed positive hem-agglutination reactivity in poultry RBC. The results indicate that the poultry feeds were highly contaminated with pathogenic enterobacteria which are risk to public health. J. bio-sci. 28: 59-68, 2020

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Incidence and Behavior of Salmonella and Escherichia coli on Whole and Sliced Zucchini Squash (Cucurbita pepo) Fruit

Journal of Food Protection ◽

10.4315/0362-028x-73.8.1423 ◽

2010 ◽

Vol 73 (8) ◽

pp. 1423-1429 ◽

Cited By ~ 22

Author(s):

JAVIER CASTRO-ROSAS ◽

EVA MARÍA SANTOS LÓPEZ ◽

CARLOS ALBERTO GÓMEZ-ALDAPA ◽

CESAR ABELARDO GONZÁLEZ RAMÍREZ ◽

JOSÉ ROBERTO VILLAGOMEZ-IBARRA ◽

...

Keyword(s):

Escherichia Coli ◽

Coliform Bacteria ◽

Most Probable Number ◽

Inoculum Level ◽

Probable Number ◽

Initial Inoculum ◽

E Coli ◽

Thermotolerant Coliforms ◽

Salmonella Serotypes ◽

And Behavior

The incidence of coliform bacteria (CB), thermotolerant coliforms (TC), Escherichia coli, and Salmonella was determined for zucchini squash fruit. In addition, the behavior of four serotypes of Salmonella and a cocktail of three E. coli strains on whole and sliced zucchini squash at 25 ± 2°C and 3 to 5°C was tested. Squash fruit was collected in the markets of Pachuca city, Hidalgo State, Mexico. CB, TC, E. coli, and Salmonella were detected in 100, 70, 62, and 10% of the produce, respectively. The concentration ranged from 3.8 to 7.4 log CFU per sample for CB, and <3 to 1,100 most probable number per sample for TC and E. coli. On whole fruit stored at 25 ± 2°C or 3 to 5°C, no growth was observed for any of the tested microorganisms or cocktails thereof. After 15 days at 25 ± 2°C, the tested Salmonella serotypes had decreased from an initial inoculum level of 7 log CFU to <1 log, and at 3 to 5°C they decreased to approximately 2 log. Survival of E. coli was significantly greater than for the Salmonella strains at the same times and temperatures; after 15 days, at 25 ± 2°C E. coli cocktail strains had decreased to 3.4 log CFU per fruit and at 3 to 5°C they decreased to 3.6 log CFU per fruit. Both the Salmonella serotypes and E. coli strains grew when inoculated onto sliced squash: after 24 h at 25 ± 2°C, both bacteria had grown to approximately 6.5 log CFU per slice. At 3 to 5°C, the bacterial growth was inhibited. The squash may be an important factor contributing to the endemicity of Salmonella in Mexico.

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Enumeration of Total Aerobic Bacteria and Escherichia coli in Minced Meat and on Carcass Surface Samples with an Automated Most-Probable-Number Method Compared with Colony Count Protocols

Journal of Food Protection ◽

10.4315/0362-028x-69.10.2500 ◽

2006 ◽

Vol 69 (10) ◽

pp. 2500-2503 ◽

Cited By ~ 12

Author(s):

P. PAULSEN ◽

E. SCHOPF ◽

F. J. M. SMULDERS

Keyword(s):

Escherichia Coli ◽

Bacterial Flora ◽

Colony Count ◽

Plate Count ◽

Most Probable Number ◽

Probable Number ◽

E Coli ◽

Plate Count Agar ◽

Two Samples ◽

Minced Meat

An automated most-probable-number (MPN) system for the enumeration of total bacterial flora and Escherichia coli was compared with plate count agar and tryptone-bile-glucuronide (TBX) and ColiID (in-house method) agar methodology. The MPN partitioning of sample aliquots was done automatically on a disposable card containing 48 wells of 3 different volumes, i.e., 16 replicates per volume. Bacterial growth was detected by the formation of fluorescent 4-methylumbilliferone. After incubation, the number of fluorescent wells was read with a separate device, and the MPN was calculated automatically. A total of 180 naturally contaminated samples were tested (pig and cattle carcass surfaces, n = 63; frozen minced meat, n = 62; and refrigerated minced meat, n = 55). Plate count agar results and MPN were highly correlated (r = 0.99), with log MPN =−0.25 + 1.05·log CFU (plate count agar) (n = 163; range, 2.2 to 7.5 log CFU/g or cm2). Only a few discrepancies were recorded. In two samples (1.1%), the differences were ≥1.0 log; in three samples (1.7%), the differences were ≥0.5 log. For E. coli, regression analysis was done for all three methods for 80 minced meat samples, which were above the limit of detection (1.0 log CFU/g): log MPN = 0.18 + 0.98·log CFU (TBX), r = 0.96, and log MPN =−0.02 + 0.99·log CFU (ColiID), r = 0.99 (range, 1.0 to 4.2 log CFU/g). Four discrepant results were recorded, with differences of >0.5 but <1.0 log unit. These results suggest that the automated MPN method described is a suitable and labor-saving alternative to colony count techniques for total bacterial flora and E. coli determination in minced meat or on carcass surfaces.

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ColiComplete® Substrate-Supporting Disc Method for Confirmed Detection of Total Coliforms and Escherichia coli in All Foods: Comparative Study

Journal of AOAC International ◽

10.1093/jaoac/77.1.58 ◽

1994 ◽

Vol 77 (1) ◽

pp. 58-63 ◽

Cited By ~ 1

Author(s):

Philip T Feldsine ◽

Maria T Falbo-Nelson ◽

David L Hustead

Keyword(s):

Escherichia Coli ◽

Comparative Study ◽

Total Coliform ◽

Coliform Bacteria ◽

Most Probable Number ◽

Probable Number ◽

Total Coliforms ◽

E Coli ◽

Total Coliform Bacteria ◽

Better Than

Abstract The ColiComplete® substrate-supporting disc (SSD) method for simultaneous confirmed total coliform count and Escherichia coli determination in all foods was compared with the AOAC most probable number (MPN) methods 966.23 and 966.24. In this comparative study, 20 water and food types were analyzed; 7 of these foods were naturally contaminated with coliform bacteria, 6 food types were naturally contaminated with E. coli, and the remaining foods were inoculated with coliform bacteria and/or E. coli. Data were analyzed separately for total coliform bacteria and for E. coli. Mean log MPN counts were determined by the SSD method and the appropriate AOAC MPN procedure. Results were then analyzed for mean log MPN differences and variance, according to methods described by AOAC INTERNATIONAL Results for both total conforms and E. coli indicate that the SSD method is equivalent to or better than AOAC MPN methods 966.23 and 966.24.

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Comparison of Colilert-18 with miniaturised most probable number method for monitoring of Escherichia coli in bathing water

Journal of Water and Health ◽

10.2166/wh.2015.071 ◽

2015 ◽

Vol 14 (1) ◽

pp. 121-131 ◽

Cited By ~ 5

Author(s):

Ananda Tiwari ◽

Seppo I. Niemelä ◽

Asko Vepsäläinen ◽

Jarkko Rapala ◽

Seija Kalso ◽

...

Keyword(s):

Escherichia Coli ◽

False Negative ◽

Reference Method ◽

Water Quality Monitoring ◽

Coliform Bacteria ◽

Most Probable Number ◽

Probable Number ◽

E Coli ◽

Negative Results ◽

Bathing Water

The purpose of this equivalence study was to compare an alternative method, Colilert-18 Quanti-Tray (ISO 9308-2) with the European bathing water directive (2006/7/EC) reference method, the miniaturised most probable number (MMPN) method (ISO 9308-3), for the analysis of Escherichia coli. Six laboratories analysed a total of 263 bathing water samples in Finland. The comparison was carried out according to ISO 17994:2004. The recovery of E. coli using the Colilert-18 method was 7.0% and 8.6% lower than that of the MMPN method after 48 hours and 72 hours of incubation, respectively. The confirmation rate of presumptive E. coli-positive wells in the Colilert-18 and MMPN methods was high (97.8% and 98.0%, respectively). However, the testing of presumptive E. coli-negative but coliform bacteria-positive (yellow but not fluorescent) Colilert-18 wells revealed 7.3% false negative results. There were more false negatives in the naturally contaminated waters than in the samples spiked with waste water. The difference between the recovery of Colilert-18 and the MMPN method was considered not significant, and subsequently the methods are considered as equivalent for bathing water quality monitoring in Finland. Future bathing water method equivalence verification studies may use the data reported herein. The laboratories should make sure that any wells showing even minor fluorescence will be determined as positive for E. coli.

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DETEKSI BAKTERI Escherichia coli DALAM AIR MINUM ISI ULANG YANG DISTERILISASI ULTRAVIOLET DI WILAYAH KECAMATAN JAGAKARSA

Jurnal BIOMA ◽

10.21009/bioma1101.8 ◽

2017 ◽

Vol 11 (1) ◽

pp. 73

Author(s):

Rezki Rachmawati ◽

Muzajjanah Muzajjanah ◽

Yoswita Rustam

Keyword(s):

Escherichia Coli ◽

Drinking Water ◽

Water Samples ◽

Coliform Bacteria ◽

Most Probable Number ◽

Coliform Bacterium ◽

Probable Number ◽

E Coli ◽

Biological Contamination ◽

Drinking Water Samples

Refill Water Depot is currently more widely circulated and used as an alternative drinking water supply by the public. However the still unclear about the quality of the drinking water refill generated primarily of biological content. Parameters of biological contamination in drinking water caused by the Escherichia coli and coliform bacterium. This study aims to identify E. coli and coliforms in drinking water refill. Refill drinking water samples obtained from 16 drinking water refill from Jagakarsa subdsitrict. The method used is descriptive. Refill drinking water samples was taken and tested in the MPN (Most Probable Number) method and then to be tested in identification of E. coli. The results of testing the drinking water refill obtained 15 samples positive for coliform bacteria. Samples were positive for E. coli bacteria that sample B.1 and F.2.

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FATE OF ENTEROPATHOGENIC STRAINS OF ESCHERICHIA COLI DURING THE MANUFACTURE AND RIPENING OF CAMEMBERT CHEESE1

Journal of Milk and Food Technology ◽

10.4315/0022-2747-36.11.543 ◽

1973 ◽

Vol 36 (11) ◽

pp. 543-546 ◽

Cited By ~ 17

Author(s):

H. S. Park ◽

E. H. Marth ◽

N. F. Olson

Keyword(s):

Escherichia Coli ◽

Rapid Growth ◽

Starter Culture ◽

Most Probable Number ◽

Probable Number ◽

Pasteurized Milk ◽

E Coli ◽

Streptococcus Cremoris ◽

C 50 ◽

Camembert Cheese

Camembert cheese was made from pasteurized milk inoculated to contain, per milliliter, approximately 100 cells of enteropathogenic strains of Echerichia coli. A Most Probable Number technique was used to enumerate E. coli at intervals during manufacture and ripening of the cheese. Identity of isolates obtained was determined serologically. Growth of E. coli was minimal until after curd was cut and hooped. Rapid growth ensued and populations in excess of 104/g appeared in some Cheeses 5 h after the Cheesemaking process began. Overnight storage of Cheese in hoops was accompanied by a decline in numbers of viable E. coli. This coincided with a drop in pH of the Cheese to 5.0 or below. Salting of cheese and 1 day of ripening at 15.6 C ( 60 F) caused a further decline in number of viable E. coli. This decline continued during the rest of the week at 15.6 C ( 60 F) and during storage at 10 C (50 F). From 0 to 9 weeks at 10 C (50 F) were required before cheese was free of viable E. coli. Substitution of Streptococcus cremoris C1 for a commercial lactic starter culture favored survival of E. coli so that 9-week old Cheese contained >104/g. When cheese was made from milk that contained penicillin, the E. coli population was approximately 109/g in 24-h old cheese and 107/g when the Cheese was 9 weeks old.

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