Presence of pathogenic bacteria in ice cubes and evaluation of their survival in different systems

Presence of Indicator Bacteria and Occurrence of Potentially Pathogenic Nontuberculous Mycobacteria Species in Packaged Ice Cubes in Central Mexico

This study aimed to determine the bacteriological quality and presence of diarrheagenic Escherichia coli pathotypes (DEP) and nontuberculous mycobacteria (NTM) species in 85 packaged ice samples from 12 different states of central Mexico. Three samples had a pH of 9.8 and therefore fell outside of the acceptable range for pH. All samples were positive for aerobic-mesophilic bacteria, with limits ranging from 1 to 3.47 log CFU/mL. In total, 35, 11, and 3 ice samples were positive for total coliforms (TC), fecal coliforms (FC), and E. coli, respectively. In the samples, the TC concentration ranged from <1.1 to >23 MPN/100 mL and from <1.1 to 23 MPN/100 mL for FC and E. coli. In total, 38 (44.7%) ice samples were outside of Mexico's official guidelines. None of the 12 E. coli strains isolated from the three ice samples belonged to DEP. NTM were recovered from 20 ice samples and included M. neoaurum (n = 7), M. porcinum (n = 2), M. flavescens (n = 2), M. fortuitum (n = 1), M. abscessus (n = 1), M. senegalense (n = 1), M. conceptionense (n = 1), and M. sp. (n = 1). In the remaining four samples, two NTM were isolated simultaneously. Thus, we recommend that producers should evaluate the microbiological quality of purified water used as a raw material as well as that of the final product, the ice should be packed in thick bags to avoid stretching and tearing during transportation or storage to prevent environmental contamination of ice, personnel involved in the production, and handling of ice should be trained in relative hygiene matters and how ice-machines should be cleaned and disinfected and the implementation of hazard analysis and critical control points must be applied throughout the chain of production. Finally, regular inspection by the authorities is also of great importance. These recommendations can be applied in different countries with low microbiological quality packaged ice.

Eco-Friendly and Self-Sanitizing Microporous Cellulose Sponge (MCS)-Based Cooling Media for Mitigating Microbial Cross-Contamination in the Food Cold Chain

Maintaining precise temperature control is vital for cold chain food transport, as temperature fluctuations can cause significant food safety and quality issues. During transport, ice that melts can promote the growth of microbes and their spread, resulting in microbial cross-contamination. This study developed sustainable, non-melting, self-sanitizing "ice cubes" using food grade compositions including microporous cellulose sponges (MCS) and photosensitizers, aimed at enhancing temperature regulation and minimizing microbial contamination in the cold chain. Upon absorbing water, the MCS matched traditional ice in cooling efficiency and heat absorption and exhibit remarkable mechanical and thermal durability, withstanding multiple freeze-thaw cycles and compressive stresses. The cationic MCS combined with erythrosine B demonstrated strong self-sanitizing capabilities, effectively reducing microbial cross-contamination in food models. Additionally, the release rates of photosensitizers from the MCS can be modulated by altering environmental ionic strength. This research offers viable solutions to address microbial cross-contamination challenges in current cold chain systems.

First evidence of microplastic contamination in ready-to-use packaged food ice cubes

Concern over microplastics has grown tremendously, and they have been found in all environmental compartments; yet, much remains unknown regarding their impact on a variety of human-consuming food products. Here, we contribute to ongoing research by screening the 15 most popular commercial brands of packaged food ice cubes in Mexico City for microplastics. Microplastics were detected in 100% of the samples evaluated, with concentrations ranging from 19 ± 4 to 178 ± 78 L^-1. There was a significant difference in the microplastic concentration across samples. The mean microplastic concentration was 79 ± 47 L^-1, and the main types were polypropylene, polyethylene, polyvinyl alcohol, tygon polymer, sealing ring gardena 2824 large, polyamide 6, and cellophane. Moreover, microplastics that are fibrous (87%), non-colored (54%), and less than 300 μm in size (63%), were found to be more prevalent. The SEM-EDX analysis showed heterogeneous structural and morphological characteristics of microplastics, as well as traces of Si, S, Ti, Ca, Al, and Na. Furthermore, we estimate that ice cube consumption in Mexico City can result in the inadvertent ingestion of 4.9 × 10² ± 3.4 × 10²-1 × 10⁴ ± 7.2 × 10³ microplastics annually. The findings of the study revealed that microplastics were identified in ice cubes and can be conveyed to humans, stressing the need of managing and eradicating such contamination from our food.

Phytochemical Profile and Antioxidant, Antiproliferative, and Antimicrobial Properties of Rubus idaeus Seed Powder

In the context of the contemporary research on sustainable development and circular economy, the quest for effective strategies aimed at revaluation of waste and by-products generated in industrial and agricultural production becomes important. In this work, an ethanolic extract from red raspberry (Rubus idaeus) seed waste (WRSP) was evaluated for its phytochemical composition and functional properties in term of antioxidative, antiproliferative, and antimicrobial activities. Chemical composition of the extract was determined by both HPLC-ESI-MS/MS and spectrophotometric methods. Phytochemical analysis revealed that flavan-3-ols and flavonols were the major phenolic compounds contained in WRSP. The extract demonstrated very high radical-scavenging (4.86 ± 0.06 µmol TE/DW) and antioxidant activity in a cell-based model (0.178 ± 0.03 mg DW/mL cell medium). The WRSP extract also exhibited antiproliferative activity against three different epithelial cancer cell lines (MCF-7, HepG2, and HeLa cells) in a dose-dependent manner. Finally, microbiological assays showed the absence of colonies of bacteria and microscopic fungi (yeasts and molds) and revealed that the WRSP extract has a large inhibition spectrum against spoilage and pathogenic bacteria, without inhibitory activity against pro-technological bacteria. In conclusion, the obtained results show that WRSP is a rich source of phytochemical compounds exerting interesting biological activities. For these reasons WRSP could find applications in the nutritional, nutraceutical, and pharmacological fields.

The Presence of Opportunistic Premise Plumbing Pathogens in Residential Buildings: A Literature Review

Opportunistic premise plumbing pathogens (OPPP) are microorganisms that are native to the plumbing environment and that present an emerging infectious disease problem. They share characteristics, such as disinfectant resistance, thermal tolerance, and biofilm formation. The colonisation of domestic water systems presents an elevated health risk for immune-compromised individuals who receive healthcare at home. The literature that has identified the previously described OPPPs (Aeromonas spp., Acinetobacter spp., Helicobacter spp., Legionella spp., Methylobacterium spp., Mycobacteria spp., Pseudomonas spp., and Stenotrophomonas spp.) in residential drinking water systems were systematically reviewed. By applying the Preferred reporting items for systematic reviews and meta-analyses guidelines, 214 studies were identified from the Scopus and Web of Science databases, which included 30 clinical case investigations. Tap components and showerheads were the most frequently identified sources of OPPPs. Sixty-four of these studies detected additional clinically relevant pathogens that are not classified as OPPPs in these reservoirs. There was considerable variation in the detection methods, which included traditional culturing and molecular approaches. These identified studies demonstrate that the current drinking water treatment methods are ineffective against many waterborne pathogens. It is critical that, as at-home healthcare services continue to be promoted, we understand the emergent risks that are posed by OPPPs in residential drinking water. Future research is needed in order to provide consistent data on the prevalence of OPPPs in residential water, and on the incidence of waterborne homecare-associated infections. This will enable the identification of the contributing risk factors, and the development of effective controls.

Food Hygiene Surveillance in Italy: Is Food Ice a Public Health Risk?

Food ice is used as an ingredient or as a coolant in drinks and in the storage of food, especially fishery products. Studies show that ice can be polluted both by chemical substances and by bacteria and fungi. In particular, the presence of fungi in these food matrices has acquired an important role in Public Health, as it can represent a risk factor for fungal complications in immunocompromised subjects. In the present study we evaluated the hygiene-sanitary quality of food ice from public and collective catering establishments in a large area of Southern Italy, investigating the mandatory parameters (Escherichia coli, coliform and Enterococci) and some accessory parameters (Staphylococcus aureus, Pseudomonas aeruginosa and fungi) provided for Italian Legislative Decree 31/01. Although 54.5% of samples were compliant, the results highlight a vast contamination of food ice by bacteria and fungi. In particular, 95.8% of samples were contaminated by fungi, stressing no difference between compliant and non-compliant samples. Their presence is generally attributable to the poor sanitation conditions in the production and/or administration phase and to the incorrect sanitization and ordinary maintenance procedures. It seems appropriate to suggest the need to carry out a specific risk assessment with respect to the self-control plans.