Category Archives: Coliforms

Research – Microbial Load of Fresh Blueberries Harvested by Different Methods



Currently, more and more growers are transitioning to the use of over-the-row machine harvesters for harvesting fresh market blueberries. This study assessed the microbial load of fresh blueberries harvested by different methods. Samples (n = 336) of ‘Draper’ and ‘Liberty’ northern highbush blueberries, which were harvested using a conventional over-the-row machine harvester, a modified machine harvester prototype, ungloved but sanitized hands, and hands wearing sterile gloves were collected from a blueberry farm near Lynden, WA, in the Pacific Northwest at 9 am, 12 noon, and 3 pm on four different harvest days during the 2019 harvest season. Eight replicates of each sample were collected at each sampling point and evaluated for the populations of total aerobes (TA), total yeasts and molds (YM), and total coliforms (TC), as well as for the incidence of fecal coliforms and enterococci. The harvest method was a significant factor (p < 0.05) influencing the TA and TC counts, the harvest time was a significant factor influencing the YM counts, while the blueberry cultivar was an insignificant (p > 0.05) factor for all three indicator microorganisms. These results suggest that effective harvester cleaning methods should be developed to prevent fresh blueberry contamination by microorganisms. This research will likely benefit blueberry and other fresh fruit producers.

Research – Increasing the Safety and Storage of Pre-Packed Fresh-Cut Fruits and Vegetables by Supercritical CO2 Process



This work presents a feasibility lab-scale study for a new preservation method to inactivate microorganisms and increase the shelf life of pre-packed fresh-cut products. Experiments were conducted on coriander leaves and fresh-cut carrots and coconut.
The technology used the combination of hydrostatic pressure (<15 MPa), low temperature (≤45 °C), and CO2 modified atmosphere packaging (MAP). The inactivation was achieved for the naturally present microorganisms (total mesophilic bacteria, yeasts and molds, total coliforms) and inoculated E. coli. Yeasts and molds and coliform were under the detection limit in all the treated samples, while mesophiles were strongly reduced, but below the detection limit only in carrots.
Inoculated E. coli strains were completely inactivated (>6.0 log CFU/g) on coconut, while a reduction >4.0 log CFU/g was achieved for carrots and coriander. For all the treated products, the texture was similar to the fresh ones, while a small alteration of colour was detected. Microbiological stability was achieved for up to 14 days for both fresh-cut carrots and coconut.
Overall, the results are promising for the development of a new mild and innovative food preservation technique for fresh food.

Austria – S-BUDGET ASTORIA Natural still mineral water in a 1.5 liter non-returnable bottle – Coliforms


AGES informs about a recall of the company SPAR. On July 4th, 2022, the company recalled the product S-BUDGET ASTORIA still natural mineral water in the 1.5 liter non-returnable bottle:
recall reason
coliform bacteria
Marketed by
Expiry Date

As a precaution, SPAR is recalling S-BUDGET ASTORIA natural mineral water still in the 1.5 liter non-returnable bottle

Salzburg (OTS) – SPAR continuously controls the products of the SPAR brands to ensure the highest quality. During a routine quality control, the product “S-BUDGET ASTORIA natural mineral water still in the 1.5 liter disposable bottle” with best-before dates (MHD) 05/31/2023 and 06/01/2023 was found to contain a small amount of coliform bacteria that is greater than the permissible limit established. For this reason, SPAR is recalling the product with the above best before dates.

Customers are asked not to drink the “S-BUDGET ASTORIA natural mineral water still in the 1.5 liter disposable bottle”. All other S-BUDGET products or mineral water from other SPAR brands are not affected by this recall.

All customers who have already bought one of the products that may be affected can of course return it to the nearest SPAR, EUROSPAR or INTERSPAR store or Maximarkt. Customers are reimbursed the purchase price even without proof of purchase.

Customers who have questions about this are welcome to contact customer service at or call the freephone number 0800 / 22 11 20 .

Research – Microbiological Profile, Prevalence and Characterization of Salmonella enterica in Peanuts, Pecans, Raisins, Sun-dried Tomatoes, and Chocolate Sprinkles Sold in Bulk in Markets of Queretaro, Mexico 

Journal of Food Protection

In Mexico, the prevalence of Salmonella enterica in low water activity foods and their link to outbreaks is unknown. The aim of this study was to determine the microbiological profile and the prevalence of S. enterica in low water activity foods (peanuts, pecans, raisins, sun-dried tomatoes, and chocolate sprinkles) purchased in retail establishments in Queretaro, Mexico. Seventy samples of each food item sold in bulk were purchased. Aerobic plate count (APC), molds, yeasts, total coliforms, Escherichia coli, and Staphylococcus aureus were quantified in 10-g samples. The prevalence of S. enterica in 25 g samples was determined. From positive samples, S. enterica  isolates (60) were characterized based on their antimicrobial susceptibility to 14 antibiotics, the presence/absence of 13 virulence genes and serotype. The concentration of APC, molds, yeast, total coliforms, and E. coli ranged from 3.1-5.2 Log CFU g-1, 2.0-2.4 Log CFU g-1, 2.0-3.0 Log CFU g-1, 0.6-1.1 Log MPN g -1, and 0.5-0.9 Log MPN g -1, respectively. S. aureus  was not detected in any sample (<10 CFU g -1). The prevalence of  S. enterica in chocolate sprinkles, raisins, peanuts, pecans, and sun-dried tomatoes was 26%, 29%, 31%, 40%, and 52%, respectively. Most isolates (68.3%) were resistant to at least one antibiotic. The chromosome-associated virulence genes were found in all isolates and only one strain had sopE, and 98.3% of the isolates were grouped in the same virulotype. Among the isolates, the most frequent serotype was Tennessee (51/60). According to the characteristics evaluated, the isolates were grouped in 24 clusters. The elevated prevalence of S. enterica highlight the role of low water activity food items sold in bulk at markets as a potential vehicle for pathogens transmission. Regardless of the low variability among S. enterica isolates, their characterization could be helpful to elucidate which strains are circulating in these foods for improving epidemiological surveillance.

India – Food poisoning: E.Coli, Coliforms found in samples from snacks shop

New Indian Express

KASARGOD: The presence of e-Coli and coliform bacteria was found in the food samples taken from Ideal snacks bar at Cheruvathur, said an official source. The Department of Food Safety had sent the samples for testing at the Regional Analytical Laboratory in Kozhikode after a schoolgirl, who had shawarma from the eatery, died, and another 52 persons who ate from there fell sick.

The presence of the highly contagious shigella bacteria, which causes intestinal infection, was found in the blood and stool samples of the patients tested at Kozhikode Medical College Hospital.
The laboratory is now conducting tests on the food samples to ascertain the presence of shigella and salmonella, another bacteria that affect the intestinal tracts, said the source. Only after these two tests, the report would be officially released.

Research – Evaluation of Hygiene Indicators and Sampling Plan for Detecting Microbial Contamination in Health Functional Foods

Journal of Food Protection

This study aimed to monitor microbial contamination level in a variety of health functional foods and to establish new microbial criteria. Indicator organisms (i.e., aerobic bacteria, coliform bacteria, and Escherichia coli ) were monitored in 10 health functional food categories (743 items, 3,715 samples). The mean total aerobic counts of ginseng and Korean red ginseng were -0.35 and -0.74 log10 CFU/g; and their mean total coliform counts were -1.4 and -1.39 log10 CFU/g, respectively. In addition, the mean total coliform counts of fiber and protein products were -1.34 and -1.22 log10 CFU/g, respectively. However, no aerobic or coliform cells were detected in any other health functional food products (vitamins, minerals, probiotics, milk thistle extract, propolis, eicosapentaenoic acid, docosahexaenoic acid, or lutein products), and no E. coli was detected in any of the categories. These results can potentially be used to update the microbial criteria of the Health Functional Food Code.

USA – Mi Ranchito Fresh Cheese recalled in 11 states because of Coliform Bacteria

Food Safety News

Quesos La Ricura Ltd. is recalling nearly 2,500 units of  Mi Ranchito Fresh Cheese with Hot Peppers because of elevated levels of Coliforms.

The recalled product was distributed in Massachusetts, Colorado, Louisiana, Texas, Florida, Maryland, North Carolina, Iowa, New York, Connecticut and New Jersey.

There is concern that consumers may still have the product in their homes because of its long shelf life.

Recalled product:

  • Quesos La Ricura Mi Ranchito Fresh Cheese with Hot Peppers, 14. 0z.
  • Sell by March 20, 2022
  • 2478 individual units

Consumers who have purchased the recalled products are urged to return them to the place of purchase.

Research – Coliform and Escherichia coli contamination on external and internal surfaces of beef carcasses with and without tissue adhesion excision

Journal of Food Protection

Following removal of hides and viscera during beef processing, carcasses are inspected for tissue adhesions that can affect meat quality or harbor bacteria. Carcasses with pleural or abdominal adhesions may be diverted from the production line for manual excision, then returned to the line. No published data indicate whether adhesion excision is associated with bacterial contamination. Therefore, our objective was to determine the presence and concentration of generic Escherichia coli and non- E. coli coliforms from the internal and external surfaces of carcasses that were, or were not, diverted for adhesion excision. During nine processing days over a four-month period in a large commercial beef processing facility, 1,738 carcass sponge samples from 2,730 cm2 areas on both the internal and external surfaces of carcasses with and without tissue adhesions were collected. Coliforms and E. coli were cultured and enumerated using PetrifilmTM procedures, and data were analyzed with mixed models. Coliforms were present at higher concentrations than E. coli, and prevalence and mean log concentrations of both coliforms and E. coli were significantly higher for samples from the external than from the internal surfaces of carcasses.  However, differences in prevalence and concentration of coliforms between external and internal surfaces varied significantly based on whether carcasses did or did not have adhesions excised. The difference was greatest for coliforms present on the external (2.06 log CFU/100 cm2) versus the internal (0.93 log CFU/100 cm2) carcass surfaces without adhesions, while the difference in concentrations from the external (1.80 log CFU/100 cm2) and internal (1.31 log CFU/100 cm2) surfaces of carcasses with adhesions was not as large.  These results indicate that surveillance of carcass bacteria may be impacted by whether the external versus internal surfaces are sampled, and also on whether carcasses are diverted for excision of adhesions.

Research – Gaseous chlorine dioxide inactivation of microbial contamination on whole black peppercorns

Wiley Online

Black peppercorn is a common ingredient imported and used in uncooked or ready-to-eat foods in the United States. They might be exposed to fecal coliforms and other microbial contamination due to a lack of good agricultural and manufacturing practices in some developing countries under which they were grown and harvested, thus causing economic losses to the peppercorn industry in the United States. We investigated the effect of gaseous chlorine dioxide (ClO2) on reducing the microbial population levels of coliforms, aerobic bacteria, yeasts, and molds on unprocessed black peppercorns. Treatments on peppercorns were conducted in a 30-L airtight chamber, and equal amounts of dry media precursors were used to generate gaseous ClO2. Whole peppercorns (200 g) were exposed to 20, 30, and 40 g of precursor dose for up to 60 min at 21 ± 0.4°C and in combination with mild heat at 40 ± 2°C. Aerobic bacteria, coliforms, yeasts, and molds on peppercorns were enumerated before (7.4, 7.2, and 7.1 log CFU/g, respectively) and after treatments. Results after treatment demonstrated 0.8–1 log10 (90%) reduction for all the microbes post-treatment at 21 ± 0.4°C. The treatments conducted with a 30 g precursor dose for 60 min at 21 ± 0.4°C reduced statistically higher (p < .05) microorganisms than those at 40 ± 2°C. Our work demonstrated that gaseous ClO2 could be used as a part of an overall hurdle technology to reduce the coliforms, aerobes, yeasts, and molds on black peppercorns without affecting the visual quality.

USA – DC issues Boil Water Advisory for parts of Northeast after E. coli concerns



The District has issued a Boil Water Advisory for portions of the Northeast due to the possibility of elevated levels of E. coli/coliform bacteria.

The advisory was issued Thursday and includes the neighborhoods of Edgewood, Brookland, Fort Lincoln, Woodridge, Queens Chapel, Michigan Park and North Michigan Park. Officials say approximately 14,000 residents have been affected.

The impacted region is approximately:

– East of North Capitol Street

– West of Eastern Avenue

– South of New Hampshire Avenue

– North of New York Avenue