Category Archives: Microbiology

USA -Listeria Warning – don’t eat Pet Food and Wash Your Hands

Food Poison Journal

Thogersen Family Farm of Stanwood, WA is voluntarily recalling raw frozen ground pet food because it has the potential to be contaminated with Listeria monocytogenes. The following varieties, packaged in two pound packs, are included in this recall: course ground rabbit, course ground mallard duck, ground llama, and ground pork frozen raw pet food

L. monocytogenes can affect animals eating the products and there is risk to humans from handling contaminated pet products, especially if they have not thoroughly washed their hands after having contact with the products or any surfaces exposed to these products.

Research – The effect of gamma irradiation on microbial load of purple basil (Ocimum bacilicum L.) leaves dried in different methods

Wiley Online

Abstract

The effect of different drying methods on microbial load of the purple basil leaves was studied with sunlight drying, convective drying at 50 °C, a microwave drying at 460 W and freeze‐drying. Microbial contamination control was evaluated using a gamma irradiation method at 10 kGy. Microbial analysis of total aerobic mesophilic bacteria and, yeast and molds count were performed. The results showed that the dried materials were contaminated with aerobic mesophilic bacteria which varied from 5.25 to 6.31 log cfu/g, and yeasts and molds 4.92–5.35 log cfu/g. The lower numbers of total mesophilic bacteria and yeasts and molds were counted in purple basil leaves dried by microwave and convective methods. According to the International standards, the dried purple basil leaves of the total aerobic mesophilic bacteria and yeasts and molds counts were unsatisfactory. No microorganisms were detected after gamma‐irradiation dose of 10 kGy.

Practical applications

Basil (Ocimum basilicum L.) is an aromatic and medicinal plant for cooking and seasoning, and it is commercialized in both fresh and dried forms. The leaves can be used as a spice in fresh or dried form for adding distinctive aroma and flavor in food or for medicinal purposes such as inflammations, colds, headaches, and cosmetics. Several drying methods have been applied for the basil leaves. However, to reduce microbial load, it is important to implement the gamma‐irradiation process. This study was done to investigate the microbial load and the effect of different methods of drying treatment (sunlight, convective, microwave, freeze‐drying, and gamma irradiation) on microbial load of dried purple basil leaves.

Research – An approach to improve the safety and quality of ready‐to‐eat blueberries

Wiley Online

Abstract

Bioactive edible coatings were developed and applied to blueberries as a natural treatment. E. coli O157:H7, L. innocua, S. aureus, and P. aeruginosa were subjected to four bioactive compounds and to three film‐forming solutions (FFS). Vanillin and geraniol at low concentrations (1.2–1.8 mg/mL and 0.4–1 μL/mL) demonstrated significant inhibitory effects on all pathogens counts. Chitosan (Ch) showed a high antimicrobial activity (final counts below 2 log CFU/mL). The effectiveness of Ch plus vanillin (Ch‐Va) and geraniol (Ch‐Ge) in improving the safety were tested against pathogens inoculated on blueberries. Ch, Ch‐Va, and Ch‐Ge coatings exerted a bactericidal effect on all pathogens (from 1.24 to more than 2 log reductions). Significant reduction in yeast and mold counts was achieved with Ch (1.09 log) and Ch + Va (1.74 log). Sensory attributes of blueberries remained acceptable. Ch‐Va and Ch‐Ge were an alternative to improve the quality and safety and could be effective in extending the shelf life of ready‐to‐eat blueberries.

Practical applications

The present study proposes the use of natural coatings enriched with biopreservatives as a technological alternative to enhance the quality and safety of minimally processed fruits. According to the results obtained, the application of chitosan plus vanillin/geraniol coatings on fresh blueberries would allow to offer a safe product and respond the growing demand of consumers for fresh, environmentally friendly and chemical preservatives‐free foods. These findings and those obtained by the sensory evaluation support the practical application of this alternative in the minimally processed fruit industry.

Research – Microbial risks in food franchise: A step forward in establishing ideal cleaning and disinfection practices in SSOPs

Wiley Online

Abstract

Microbial contamination in coffee specialty franchises using uniform processing procedures in Korea was examined. Cleaning or disinfection practices for sanitation standard operating procedures (SSOPs) are proposed. For each processing step, food materials and associated processing environments were tested for heterotrophic bacteria (HB), Escherichia coli, coliform, and Staphylococcus aureus. Existing SSOP cleaning or disinfection practices were also evaluated. Ice‐making procedures revealed coliform and HB contamination in all coffee houses, with high HB contamination on several supplementary food materials and associated food utensils. Microbial loads in food materials or final products were high on structures and materials that are difficult to clean and disinfect. Staphylococcus species contaminated food machinery and utensils directly contacted by food handlers. Based on our analysis of cleaning and disinfection practices in each franchise’s SSOPs, current practices should be complemented to ensure food safety. Our results provide a foundation for developing sanitation standards optimized for coffee specialty franchises.

Practical applications

Franchise brands operating collectively require well‐established sanitation practices such as sanitation standard operating procedures (SSOPs) to ensure food safety and quality. Microbiological studies were performed to evaluate coffee processing procedures and environments at specialty franchise brands. Hygiene practices in SSOPs were simultaneously evaluated to examine cleaning and disinfection procedures. In several processing procedures and associated processing environments, coliform and Staphylococcus aureus were detected on food handlers’ hands, gloves, and hand‐accessible areas of food utensils or machinery simultaneously. Coliforms were also detected in edible ice cubes and on related utensils or machinery for ice production or storage (ice‐making machine, ice‐bin). Heterotrophic bacteria (HB) were detected at high densities in sugar syrup (under‐using) and edible ice (during production and storage). Particularly, HB concentrations increased during processing. Thus, microbial contamination is increased by various factors during processing, particularly inappropriate cleaning or disinfection of utensils or machinery. Evaluation of cleaning and disinfection practices for each franchise’s SSOPs revealed that the cleaning and disinfection practices for machinery or utensils accessible to worker’s hands must be supplemented. Establishments serving a wide variety of coffee beverages may require complex and different processing procedures. Because utensils and machinery affecting the microbial load of the final product can vary, the areas and targets of cleaning and disinfection should be expanded. Second, the structure or material characteristics of food utensils or machinery that are difficult to clean and disinfect can lead to microbial growth. Cleaning or disinfection of food utensils or machinery should be considered in SSOPs. Purchasing management (as a major category of SSOPs for food safety) should be expanded to utensils or machinery in addition to food materials. Furthermore, cleaning and disinfection targets aimed at under‐used utensils or facilities must be established in SSOPs.

Research – Detection of pathogenic bacteria and fungi on biometric surface of Automated Teller Machines located in Brazilian public hospital

Academic Journals

The Automated Teller Machine (ATM) is used by millions of people as an alternative to gain time instead of using traditional banking systems in Brazil and ATMs are frequently localized in São Paulo city around the hospitals. However, ATMs might be potential devices for microbial accumulation and transmission in the community. The objective of the present study was to evaluate forty-two ATMs, in two hospital areas (A and B) in São Paulo city for the presence of pathogenic fungi and bacteria. Samples were collected from biometric surfaces of the devices with sterile cotton swabs soaked in the sterile physiologic saline and were cultured on selective agar for yeasts, filamentous fungi and bacteria in the period of January 2017 to March 2018. Complementary biochemical tests were applied to confirm the bacteria and the taxonomic identification of molds was performed considering the morphological characteristics by microscopic observation. Our results suggest that the biometric surfaces in ATMs is an important environmental source of microbes, once that the genera Staphylococcus was predominant in all agencies of both hospital areas (83.3%), following of Streptococcus spp. (57%) and Enterococcus spp. (50%). The group of Enterobacteriaceae (Gram negative bacilli) were most frequent in both areas studied (57%). Seven different fungi genera were isolated from ATMs in area A and B and yeasts were predominant in all samples collected (47%), comparing with filamentous fungi (23%). We conclude that biometric ATM surfaces play an important role in microbial transmission in hospital settings, and healthcare professionals should wash and disinfect their hands carefully before touching patients.

 

Research – Growth potential of Listeria monocytogenes in ready‐to‐eat Feta cheese‐based sauce stored at 4°C

Wiley Online

Abstract

Listeria monocytogenes is now a well‐known foodborne pathogen of particular importance in ready‐to‐eat (RTE) refrigerated foods given the psychrotrophic character and ubiquitous nature of the bacterium. The objective of the current research was to assess the growth potential of L. monocytogenes in RTE cheese‐based (Feta) sauce. For this to occur, samples of Feta cheese‐based sauce (ca. 1% NaCl, pH = 4.6, 900 ppm sorbic acid) were artificially contaminated with a mixture of two L. monocytogenes strains and were stored aerobically at 4°C for 30 days. Growth potential (δ) of L. monocytogenes in Feta cheese‐based sauce was calculated at −1.2 log CFU/g for the 30‐day shelf‐life (i.e., δ < 0.5 log CFU/g). Findings of this study indicate that Feta cheese‐based sauce containing 900 ppm of sorbic acid as preservative is unable to support the growth of L. monocytogenes, thus the food safety criterion for pathogen enumeration not exceeding the limit of 100 CFU/g should apply during the shelf‐life of the product, as stated by Commission Regulation (EC) No. 2073/2005.

Practical applications

Contamination of acidic cheese‐based spreadable products, with pH ≤ 4.6 and/or water activity (i.e., Aw) > 0.94, with different bacterial species during the manufacturing process, could limit considerably the shelf‐life of these RTE products. Moreover, among other possible contaminants, the ubiquitous psychrotrophic pathogen L. monocytogenes may pose a serious threat for the microbiological safety of such products, like a Feta cheese‐based sauce with the aforementioned characteristics. Challenge testing for assessing the risk from L. monocytogenes presence during shelf‐life of this product is, therefore, deemed necessary and can provide us with useful information regarding possible pathogen containment due to product’s composition and characteristics. Conclusively, even if the Feta cheese‐based sauce described in this study is contaminated with low numbers of L. monocytogenes at levels below the limit of detection (i.e., absence in 25 g), then the organism will not exceed 100 CFU/g by the end of product’s shelf‐life.

USA – Darwin’s Natural Pet Products silent recall surpassed 11 tons of raw dog food

Food Safety News

On February 7, 2019, in a move announced only via email to its direct customers, Arrow Reliance, doing business as Darwin’s Natural Pet Products (Darwin’s), recalled 11.7 tons of raw dog food.

The recall was first divulged to the public on March 26, 2019, by the US Food and Drug Administration (FDA) via a news release cautioning pet owners to avoid feeding the recalled products.

According to the FDA Enforcement Report issued on April 3, 2019, the recall encompassed:

  •  Natural Selections Turkey and Vegetable Meals for Dogs, frozen, raw dog meals, packaged in 2 lbs. thermo-formed sealed plastic package, divided into 8 oz. portions. Lot #5339, manufactured on 10/26/18 (listed as 5339(11)181026 on the label)
  • Natural Selections Chicken and Vegetable Meals for Dogs, frozen, raw dog meals, packaged in 2 lbs. thermo-formed sealed plastic package, divided into 8 oz. portions. Lot # 5309, manufactured on 10/19/18 (listed as 5309(11)181019 on the label)
  • •Natural Selections Chicken and Vegetable Meals for Dogs, frozen, raw dog meals, packaged in 2 lbs. thermo-formed sealed plastic package, divided into 8 oz. portions. Lot # 5375, manufactured on 11/6/18 (listed as 5375(11)181106 on the label)

Although Darwin’s claimed to have notified all of its affected customers via email of the Salmonella contamination, Food Safety News has learned that at least one customer did not receive the initial notification.

RASFF Alerts – Animal Feed – Salmonella – Fish Meal – Dog Chews – Coral Food – Organic Soya Bean Meal

RASFF-Logo

RASFF – Salmonella enterica ser. Kentucky (present /25g), Salmonella enterica ser. Lamberhurst (present /25g), Salmonella enterica ser. Mbandaka (present /25g), Salmonella enterica ser. Molade (present /25g) and Salmonella enterica ser. Münster (present /25g) in fish meal from the United States in Greece

RASFF – Salmonella enterica ser. Typhimurium in coral food from the United Kingdom in the UK

RASFF – Salmonella enterica ser. Brandenburg (presence /25g) and Salmonella enterica ser. Idikan (presence /25g) and too high count of Enterobacteriaceae (7400 CFU/g) in dog chews from the Netherlands in Belgium

RASFF – Salmonella enterica ser. Oranienburg (presence /25g) and Salmonella enterica ser. Telelkebir (presence /25g) in fish meal from the United States in Norway

RASFF – Salmonella enterica ser. Mbandaka (presence /25g) in organic soybean meal from the Netherlands in Belgium

Spain – Poo traces found in 88 percent of cannabis sold on Madrid streets

The Local

The first scientific study of cannabis resin sold on the streets of Madrid reveals that the vast majority contains traces of bacteria from human faeces, and poses a serious health risk to those who smoke it.

Research – Bacteria partners with virus to cause chronic wounds

Science Daily

 

A common bacterial pathogen called Pseudomonas aeruginosa produces a virus that substantially increases the pathogen’s ability to infect us, according to a study by investigators at the Stanford University School of Medicine.

P. aeruginosa weaponizes its resident virus to exploit the immune system’s distinct responses to bacterial versus viral infections.

This marks the first time a bacteria-infecting virus, otherwise known as a bacteriophage or just phage, has been observed inducing the immune system to mount an antiviral response and, in doing so, causing it to ignore the bacterial infection. When the scientists generated a vaccine directed at the virus, they showed that it dramatically lowered the bacteria’s ability to infect wounds in mice.