Microbial Quality of Bagged Baby Spinach and Romaine Lettuce: Effects of Top versus Bottom Sampling

2012 ◽  
Vol 75 (1) ◽  
pp. 132-136 ◽  
Author(s):  
JULIE A. KASE ◽  
STACEY BORENSTEIN ◽  
ROBERT J. BLODGETT ◽  
PETER C. H. FENG
Keyword(s):  
Escherichia Coli ◽  
Total Coliform ◽  
Coliform Bacteria ◽  
Most Probable Number ◽  
Microbial Quality ◽  
Romaine Lettuce ◽  
Probable Number ◽  
E Coli ◽  
Bottom Sampling

Contamination with Escherichia coli O157:H7 and Salmonella have called into question the safety and microbial quality of bagged ready-to-eat leafy greens. This study expands on previous findings that these goods have high total bacteria counts (TBC) and coliform counts, variation in counts among different lots, that Escherichia coli is present, and disparities in counts when bags are top or bottom sampled. Nearly 100 bags of baby spinach and hearts of romaine lettuce from a single brand were subjected to both top and bottom sampling. Product was blended, and a portion serially diluted and plated to obtain TBC. Total coliform and E. coli levels were estimated by the most-probable-number (MPN) technique with ColiComplete discs. Top-sampled TBC from bags of baby spinach (48 bags, 13 different lots) ranged from 3.9 to 8.1 log CFU/g and bottom-sampled TBC ranged from 4.0 to 8.2 log CFU/g, with 52% of the bags (or 39% of the lots) producing TBC higher in bottom samples. For hearts of romaine (47 bags from 19 different lots), top-sampled bags had TBC ranging from 2.4 to 7.0 log, and bottom-sampled bags had TBC from 3.3 to 7.3 log, with 64% of the bags (or 63% of the lots) showing higher TBC in bottom samples. However, we are unable to reject the hypothesis that the top and bottom samples from either commodity contain the same TBC (P ≥ 0.08). No E. coli was detected and total coliform bacteria counts were, with few exceptions, ≥210 MPN/g, irrespective of TBC. In general, lots with the most number of days before the printed “use-by” date had lower TBC. However, the R2 values for either baby spinach (0.4085) or hearts of romaine (0.2946) suggest that age might not be a very good predictor of higher TBC. TBC varied widely between lots and even more so within same-lot samples, as indicated by the sum of squares results. This finding, along with higher TBC in bottom samples, suggests further consideration when a microbiological sampling scheme of bagged produce is designed.

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

1994 ◽  
Vol 77 (1) ◽  
pp. 58-63 ◽  
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.

scholarly journals Identifikasi Bakteri Escherichia Coli pada Air Minum Isi Ulang yang Diproduksi Depot Air Minum Isi Ulang di Kecamatan Padang Selatan

2015 ◽  
Vol 4 (2) ◽  
Author(s):  
Fathoni Afif ◽  
Erly Erly ◽  
Endrinaldi Endrinaldi
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Total Coliform ◽  
Coliform Bacteria ◽  
Most Probable Number ◽  
Probable Number ◽  
Microbiological Parameters ◽  
Complete Test ◽  
Biochemistry Test

AbstrakMenurut Permenkes No. 492 tahun 2010, air minum berkualitas dinilai dari parameter mikrobiologi adalah tidak ditemukannya bakteri total coliform dan Escherichia coli dalam 100 ml sampel. Menurut beberapa penelitian sebelumnya, banyak depot air minum isi ulang yang memproduksi air tidak sesuai dengan persyaratan secara mikrobiologi tersebut. Tujuan penelitian ini adalah untuk mengidentifikasi kehadiran bakteri Escherichia coli pada air minum yang diproduksi depot air minum isi ulang di Kecamatan Padang Selatan. Penelitian dilakukan di Laboratorium Mikrobiologi Fakultas Kedokteran Universitas Andalas pada sampel air yang didapat dari 13 depot yang tidak melakukan uji kualitas. Jenis penelitian ini adalah deskriptif. Data diperoleh dengan cara observasi dan wawancara langsung. Penelitian mikrobiologi air menggunakan metode Most Probable Number (MPN) yang terdiri dari presumptive test dengan menggunakan media Lactose Broth (LB) dengan metode 3 tabung, confirmative test dengan menggunakan media Brillian Green Lactose Broth (BGLB), complete test dengan menggunakan media endo agar, dan tes identifikasi dengan menggunakan media uji biokimia. Hasil penelitian didapatkan bahwa 10 dari 13 sampel tercemar oleh bakteri coliform dan 2 sampel memenuhi syarat untuk penelitian selanjutnya secara kualitatif. Pada penelitian lanjutan, tidak ditemukan bakteri Escherichia coli namun ditemukan bakteri Pseudomonas aeruginosa.Kata kunci: escherichia coli, depot air minum isi ulang, MPN AbstractAccording to the Minister Regulation. 492 in 2010, assessed quality of drinking water in microbiological parameters is by the discovery of total coliform bacteria and Escherichia coli in a 100ml sample. According to some previous studies, many drinking water that produced by the depot does not conform to the microbiological requirements The objective of this study was to identify the presence of the Escherichia coli in drinking water produced by refill drinking water depot in the District of South Padang. Research had been carried out in the Laboratory of Microbiology, Faculty of Medicine, University of Andalas in water samples obtained from 13 depots that don’t test the quality. This research was a descriptive. Data obtained by direct observation and interviews. This research used Most Probable Number (MPN) test for the microbiological of the water that consist of presumptive test using Lactose Broth (LB), confirmative test using Brilliant Green Lactose Broth (BGLB), complete test using endo jelly media, and identification test using biochemistry test. The results showed that 10 of 13 samples contaminated by coliform bacteria and 2 samples eligible for further research that show there is a Pseudomonas aeruginosa.Keywords: escherichia coli, refill water depot, MPN

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

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

A Bacteriological Survey of Raw Ground Beef1

1977 ◽  
Vol 40 (11) ◽  
pp. 790-794 ◽  
Author(s):  
JAMES F. FOSTER ◽  
JAMES L. FOWLER ◽  
WARREN C. LADIGES
Keyword(s):  
Escherichia Coli ◽  
Microbiological Quality ◽  
Retail Store ◽  
Most Probable Number ◽  
Probable Number ◽  
E Coli ◽  
Fecal Streptococci ◽  
Plate Counts ◽  
Aerobic And Anaerobic

The microbiological quality of 150 units of raw ground beef obtained from a local retail store was determined. The range of aerobic plate counts was from 6.9 × 104 to 8.3 × 107/g. By using the most probable number method 96.7% of the 150 units were positive for coliforms, 94.7% for Escherichia coli and 61.3% for Staphylococcus aureus. By the plate methods, 99.3% of the units were positive for fecal streptococci and 56% were positive for Clostridium perfringens. No salmonellae were isolated. Aerobic and anaerobic organisms were isolated and identified. E. coli was the most frequently isolated aerobe followed by organisms in the Klebsiella-Enterobacter group. Among the anaerobic isolates, C. perfringens was the organism most frequently encountered.

scholarly journals Isolation and Enumeration of Escherichia coli from Soil and Water

2020 ◽  
Vol 36 (2) ◽  
pp. 75-77
Author(s):  
Anindita Bhowmik ◽  
Sunjukta Ahsan
Keyword(s):  
Escherichia Coli ◽  
Water Samples ◽  
Gas Production ◽  
Soil Samples ◽  
Most Probable Number ◽  
Biochemical Tests ◽  
Probable Number ◽  
E Coli ◽  
Dilution Series

Majority of the population of Bangladesh depend on tap or surface water as their source of water supply. This study was carried out to examine the microbial quality of both water and soil collected from different places using the multiple tube fermentation technique to determine coliform count by the most probable number (MPN) method in brilliant green lactose broth (BGLB) media.Inoculum from positive tubes of the presumptive test were further transferred on eosinemethylene blue (EMB) and MacConkey agar.The organisms isolated were further characterized using biochemical tests. Out of 93 water samples, 30 (32.26%) indicated the presence of lactose fermenter and gas producer in all 3 tubes of dilution series using inoculum quantities of 1.0, 0.1 and 0.01 ml, whereas out of 85 soil samples, 45 (52.94%) showed acid and gas production in all 3 tubes of dilution series.Among 85 soil samples, 40 samples that contained at least one positive in each dilution series and among 93 water samples, 31 samples that contained at least one positive in each dilution series were further re-identified with biochemical tests.This study showed 30.59% soil isolates and 26.88% water isolates were Escherichia coli which highlighted the fact that both water and soil act as a major reservoir of E.coli, which indicates possible fecal contamination as well as presence of potentially pathogenic E. coli. Bangladesh J Microbiol, Volume 36 Number 2 December 2019, pp 75-77

scholarly journals 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

2006 ◽  
Vol 89 (1) ◽  
pp. 100-114 ◽  
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.

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

1998 ◽  
Vol 61 (4) ◽  
pp. 444-449 ◽  
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.

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

2010 ◽  
Vol 73 (8) ◽  
pp. 1423-1429 ◽  
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.

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

2015 ◽  
Vol 14 (1) ◽  
pp. 121-131 ◽  
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.

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

Jurnal BIOMA ◽  
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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