Microbial Contamination of Photographic and Cinematographic Materials in Archival Funds in the Czech Republic

In this study we investigated the microbial contamination of 126 samples of photographic and cinematographic materials from 10 archival funds in the Czech Republic. Microorganisms were isolated from the light-sensitive layer by swabbing it with a polyurethane sponge. Microbial isolates were identified by MALDI-TOF MS (bacteria) or by phenotype testing and microscopy (fungi). Bacterial contamination was more abundant and more diverse than fungal contamination, and both were significantly associated with archives. The most frequently isolated fungal genera were Cladosporium, Eurotium, Penicillium, Aspergillus and Alternaria. The most frequently isolated bacteria were Gram-positive genera such as Staphylococcus, Micrococcus, Kocuria, Streptococcus and Bacillus. This bacterial and fungal diversity suggests that air is the main vehicle of contamination. We also analysed the impact of the type of material used for the carrier (paper, baryta paper, cellulose acetate and nitrate or glass) or the light-sensitive layer (albumen, gelatine, collodion and other) on the level and diversity of microbial contamination. Carriers such as polyester and cellulose nitrate may have a negative impact on bacterial contamination, while paper and baryta paper may have a partially positive impact on both fungal and bacterial contamination.

Standardizing Patient-Derived Organoid Generation Workflow to Avoid Microbial Contamination From Colorectal Cancer Tissues

The use of patient-derived organoids (PDO) as a valuable alternative to in vivo models significantly increased over the last years in cancer research. The ability of PDOs to genetically resemble tumor heterogeneity makes them a powerful tool for personalized drug screening. Despite the extensive optimization of protocols for the generation of PDOs from colorectal tissue, there is still a lack of standardization of tissue handling prior to processing, leading to microbial contamination of the organoid culture. Here, using a cohort of 16 patients diagnosed with colorectal carcinoma (CRC), we aimed to test the efficacy of phosphate-buffered saline (PBS), penicillin/streptomycin (P/S), and Primocin, alone or in combination, in preventing organoid cultures contamination when used in washing steps prior to tissue processing. Each CRC tissue was divided into 5 tissue pieces, and treated with each different washing solution, or none. After the washing steps, all samples were processed for organoid generation following the same standard protocol. We detected contamination in 62.5% of the non-washed samples, while the use of PBS or P/S-containing PBS reduced the contamination rate to 50% and 25%, respectively. Notably, none of the organoid cultures washed with PBS/Primocin-containing solution were contaminated. Interestingly, addition of P/S to the washing solution reduced the percentage of living cells compared to Primocin. Taken together, our results demonstrate that, prior to tissue processing, adding Primocin to the tissue washing solution is able to eliminate the risk of microbial contamination in PDO cultures, and that the use of P/S negatively impacts organoids growth. We believe that our easy-to-apply protocol might help increase the success rate of organoid generation from CRC patients.

Biocide Use in the Beverage Industry: Consumers’ Knowledge and Label Preferences Relating to the Need and Usefulness of Biocides with Particular Reference to Dairy Beverage Products in New Zealand and China

Biocides, in the form of sanitisers and disinfectants, are used extensively to reduce the risk of microbial contamination to beverage products and to ensure the safety of potable water used in processing. To better understand consumers’ perceptions of biocide use and to explore messaging strategies regarding their importance to ensure product safety, eight focus groups were conducted in New Zealand (n = 4) and China (n = 4). Consumers generally did not understand why or how biocides were used. In both countries, their most trustworthy source of information on biocide use was government sources. New Zealand and Chinese participants did not like the word “biocide” mentioned on labels due to its perceived negative connotations. Interestingly, acceptance for the word was higher if the phrase “environmentally friendly” was simultaneously communicated. The findings from this study have provided the beverage industry with guidance on how best to initiate conversations with consumers on the use of biocides.

Evaluation of microbial contamination in cold dishes and Prevalence of food-borne pathogens in the Jilin Province

In this study, we evaluated the microbial contamination status of cold dishes consumed by residents of Jilin Province and investigated to determine the incidence of four pathogenic bacteria in cold dishes. A total of 300 samples of cold dishes including meat, vegetable and mixed products, were collected from three different purchasing places: supermarkets, farmers' markets and mobile vendors. Live bacteria were isolated using conventional culture methods. After separation, a quick and easy polymerase chain reaction (PCR) was used to detect Listeria monocytogenes , Staphylococcus aureus , Enterotoxic Escherichia coli and Salmonella . The results showed that the total number of microbial colonies in the vegetable samples exceeded the standard rate of 8%, and the total number of microbial colonies in the meat and mixed samples did not exceed the standard. The total microbial colony count exceeded the standard in all three different procurement sites, with the highest exceedance of 7.4% in the mobile vendor sites. The detection rates of Enterotoxigenic Escherichia coli , Staphylococcus aureus , L. monocytogenes and Salmonella among the four pathogenic bacteria detected in all samples were 4.3%, 3.3%; 3.0%; and 1.0%, respectively. This study can be used to qualitatively assess the microbiological quality associated with cold dishes. It provides data to support the detection of possible food safety problems.

Lactobacillus plantarum ZJ316 improves the quality of Stachys sieboldii Miq. pickle by inhibiting harmful bacteria growth and degrading nitrite, promoting the gut microbiota health in vitro

Microbial contamination and nitrite accumulation are two major concerns on the quality control of fermented vegetables. In the present study, a lactic acid bacteria strain Lactobacillus plantarum ZJ316 (ZJ316) was...

Microbiological contamination of feed – current hazards and new challenges

Feed microflora remains a very complex and still largely uncharacterized ecosystem. Given the wide range of potential sources of microbial contamination that may come into contact with feed, a variety of microorganisms, including pathogenic ones, can be expected. Microbiological contamination of feeds depends on environmental factors, which are a natural, primary source related to the microflora carried on feed materials and coming from soil, water and air. Microbial contamination may also emerge secondarily in the processing and distribution stages of feed, but also in the breeding stage, where feed may be contaminated by animals showing disease symptoms or asymptomatically. A wide variety of pathogenic microorganisms that are transmitted symptomatically or asymptomatically can cause economic losses to feed producers and farmers, and some of them due to their zoonotic nature can also pose a potential risk to consumers. New feed materials appear on the market, i.e. Insect Processed Animal Proteins, which are part of the strategy of replacing traditional protein sources. These materials are under investigation for their benefits as well as for microbiological safety. The aim of this review was to present the current knowledge on the main microbiological risk factors influencing the quality and safety of feed, as well as new analytical challenges related to the introduction of new feed materials.