The fungicidal efficacy of various commercial disinfectants used in the food industry

COVID-19 associated Mucormycosis among ICU patients: risk factors, control, and challenges

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic is still difficult to be controlled. The spread of this virus and the emergence of new variants are considered a great challenge worldwide. Disturbance in infection control guidelines implementation, use of steroids, antibiotics, hospital crowdedness, and repeated use of oxygen masks during the management of critically ill COVID-19 patients lead to an increase in the rate of opportunistic infections. So, patients need to fight both the virus with its different variants and opportunistic pathogens including bacteria and fungi especially patients with diabetes mellitus, malignancy, or those who undergo hemodialysis and receive deferoxamine. During the pandemic, many cases of Mucormycosis associated with COVID-19 infection were observed in many countries. In this review, we discuss risk factors that increase the chance of infection by opportunistic pathogens, especially fungal pathogens, recent challenges, and control measures.

The effect of disinfectants and antiseptics on co- and cross-selection of resistance to antibiotics in aquatic environments and wastewater treatment plants

The outbreak of the SARS-CoV-2 pandemic led to increased use of disinfectants and antiseptics (DAs), resulting in higher concentrations of these compounds in wastewaters, wastewater treatment plant (WWTP) effluents and receiving water bodies. Their constant presence in water bodies may lead to development and acquisition of resistance against the DAs. In addition, they may also promote antibiotic resistance (AR) due to cross- and co-selection of AR among bacteria that are exposed to the DAs, which is a highly important issue with regards to human and environmental health. This review addresses this issue and provides an overview of DAs structure together with their modes of action against microorganisms. Relevant examples of the most effective treatment techniques to increase the DAs removal efficiency from wastewater are discussed. Moreover, insight on the resistance mechanisms to DAs and the mechanism of DAs enhancement of cross- and co-selection of ARs are presented. Furthermore, this review discusses the impact of DAs on resistance against antibiotics, the occurrence of DAs in aquatic systems, and DA removal mechanisms in WWTPs, which in principle serve as the final barrier before releasing these compounds into the receiving environment. By recognition of important research gaps, research needs to determine the impact of the majority of DAs in WWTPs and the consequences of their presence and spread of antibiotic resistance were identified.

Clinical and mycological investigations of post-COVID-19 acute invasive fungal sinusitis

Objectives

An increased incidence of acute invasive fungal sinusitis associated with the recent COVID-19 pandemic has been observed, which is considered a public health concern. This study aims to detect the incidence, risk factors, causative agents, clinical presentations, outcomes, and susceptibility rate of various antifungals.

Methods

In this cross-sectional cohort study, a total of 30 patients showing acute invasive fungal rhinosinusitis following a COVID-19 infection were investigated. Histopathological biopsies, culture identification, and molecular confirmation of the causative agents were conducted. The demographic data, risk factors, clinical presentations, treatment regimen and its outcomes, and efficacy of antifungals were listed and analyzed.

Results

A total of 30 cases with a mean age of 59.6 ± 11.9 years were included. Diabetes mellitus was the most recorded comorbidity with a rate of 86.7%, whereas most of the patients received corticosteroids. The mycological examination confirmed the existence of Mucor (Rhizopus oryzae) and Aspergillus (Aspergillus niger) in 96.7% and 3.3% of the cases, respectively. Various stages of sinonasal involvement (ethmoid, maxillary, sphenoid, and inferior turbinate) represented 100%, 83.3%, 66.7%, and 86.7% of the cases, respectively. Headache and facial pain, ophthalmoplegia, visual loss, and blindness represented 100%, 66.7%, 90%, and 53.3% of the cases, respectively. All the cases were simultaneously treated with surgical debridement and amphotericin B. Moreover, R. oryzae was susceptible to it, whereas A. niger was sensitive to voriconazole, resulting in a survival rate of 86.7% (26/30). The R. oryzae and A. niger isolates were proven to be sensitive to acetic acid, ethyl alcohol, formalin, and isopropyl alcohol.

Conclusions

In patients with COVID-19, the diagnosis of acute invasive fungal sinusitis and prompt treatment with antifungal medicine and surgical debridement are important in achieving better outcomes and survival rates.

Level of Evidence

4.

An Evaluation of Sporicidal Treatments against Blown Pack Spoilage Associated Clostridium estertheticum and Clostridium gasigenes Spores

Blown pack spoilage (BPS) occurs when meat is cross-contaminated with Clostridium estertheticum or Clostridium gasigenes spores, often from the meat processing environment. This study tested the efficacy of four sporicidal disinfectants commonly used in beef processing plants against C. estertheticum and C. gasigenes spores in a suspension test. D-values were obtained under model ‘clean’ (sterile distilled water, SDW) and ‘dirty’ (3 g/L bovine serum albumin, BSA) conditions. Mean concentration (log10 CFU/mL) were calculated from direct counts. The levels of dipicolinic acid (DPA), indicating damage to the core of these spores, was also monitored using a terbium (Tb)-DPA assay for treatment 1 (peracetic acid as the active ingredient) in SDW and BSA. In SDW sporicidal treatment 3 (containing peroxymonosulphate) was the most effective against C. estertheticum spores but under ‘dirty’ (BSA) conditions sporicidal treatments 1 and 2 were more effective. A similar pattern was obtained with C. gasigenes with treatment 3 being the most effective in SDW but treatment 2 (sodium hypochlorite as the active ingredient) being more effective in BSA. The lower DPA concentrations obtained in SDW versus BSA demonstrated the protective effect of organic matter. It was concluded that meat processors should use a 5% formulation containing sodium hypochlorite, sodium hydroxide and alkylamine oxide to eliminate BPS Clostridial spores in the abattoir.

Biocidal Resistance in Clinically Relevant Microbial Species: A Major Public Health Risk

Antimicrobial resistance is one of the greatest dangers to public health of the 21st century, threatening the treatment and prevention of infectious diseases globally. Disinfection, the elimination of microbial species via the application of biocidal chemicals, is essential to control infectious diseases and safeguard animal and human health. In an era of antimicrobial resistance and emerging disease, the effective application of biocidal control measures is vital to protect public health. The COVID-19 pandemic is an example of the increasing demand for effective biocidal solutions to reduce and eliminate disease transmission. However, there is increasing recognition into the relationship between biocide use and the proliferation of Antimicrobial Resistance species, particularly multidrug-resistant pathogens. The One Health approach and WHO action plan to combat AMR require active surveillance and monitoring of AMR species; however, biocidal resistance is often overlooked. ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens and numerous fungal species have demonstrated drug and biocidal resistance where increased patient mortality is a risk. Currently, there is a lack of information on the impact of biocide application on environmental habitats and ecosystems. Undoubtedly, the excessive application of disinfectants and AMR will merge to result in secondary disasters relating to soil infertility, loss of biodiversity and destruction of ecosystems.

Use of a Novel Sanitizer To Inactivate Salmonella Typhimurium and Spoilage Microorganisms during Flume Washing of Diced Tomatoes

ABSTRACT

As demand for fresh-cut produce increases, minimizing the risk of salmonellosis becomes critical for the produce industry. Sanitizers are routinely used during commercial flume washing of fresh-cut produce to minimize cross-contamination from the wash water. This study assessed the efficacy of a novel sanitizer blend consisting of peracetic acid (PAA; OxypHresh 15) with a sulfuric acid-surfactant (SS) antimicrobial (PAA-SS; ProduceShield Plus) against Salmonella during simulated commercial washing of diced tomatoes. Triplicate 9.1-kg batches of Roma tomatoes were dip inoculated in a two-strain avirulent Salmonella cocktail (Salmonella Typhimurium LT2 and MHM112) to achieve 5 to 6 log CFU per tomato and air dried for 2 h. After mechanical dicing, the tomatoes were washed in a pilot-scale processing line for 60 s with or without an added organic load in 90 ppm of PAA-SS (pH 1.8), SS at pH 1.8, 90 ppm of PAA, 5 or 10 ppm of free chlorine or sanitizer-free water as the control. Overall, PAA-SS (1.75 ± 0.75 log CFU/g) was significantly (P ≤ 0.05) more effective than water (0.69 ± 0.42 log CFU/g), chlorine (0.35 ± 0.36 log CFU/g), or SS (0.36 ± 0.19 log CFU/g) in reducing Salmonella. After washing for 20 s, PAA-SS was the only sanitizer to show a significant (P ≤ 0.05) reduction (1.93 ±0.59 log CFU/g) in Salmonella. All wash water samples were negative for Salmonella, except for 5 and 10 ppm of chlorine and the water control. Using PAA-SS with an organic load, yeast and mold populations were below the limit of detection (1.40 log CFU/g) and significantly (P ≤ 0.05) lower on diced tomatoes after 14 days of refrigerated storage compared with the other treatments (8.37 ± 0.08 log CFU/g), with SS at pH 1.8 (3.91 ± 0.93 log CFU/g) most effective against yeast and mold in the absence of an organic load. On the basis of these findings, the safety and shelf life of commercially washed diced tomatoes can be improved with PAA-SS.

HIGHLIGHTS

Impact of intraspecific variability and physiological state on Penicillium commune inactivation by 70% ethanol

The aim of this study was to assess the impact of the physiological state and intraspecific variability on the efficacy of 70% ethanol to inactivate conidia of Penicillium commune, used as a representative species of dairy product contaminants. Four physiological states were obtained by modifying the water activity during the production of conidia (0.995 and 0.950) and the harvesting conditions (hydrated and non-hydrated). These conditions were applied to four different P. commune strains isolated from contaminated dairy products. Five minutes exposure to 70% ethanol at ambient temperature allowed total inactivation of conidia (>4 log₁₀) regardless of the physiological state or the strain. For 1 min exposure, regardless of the strains, only dry-harvested conidia produced at a_w 0.950 exhibited survivors. Survival after 2 min exposure was observed for this physiological state for P. commune UBOCC-A-116003 only. For this strain, the impact of the physiological state was greater than 1.54 log₁₀ between dry-harvested conidia produced at a_w 0.950 that exhibited survivors after 1 min treatment and the 3 other kinds of conidia that were all inactivated. For 1 min exposure, by comparing the more resistant strain to the three other strains, the impact of the intraspecific variability was 2.35 log₁₀. These results demonstrated that the physiological state of the conidia, the representativeness of the tested species and strains should be taken into account to assess the efficacy of disinfectants in dairies.

Effective Fungal Spore Inactivation with an Environmentally Friendly Approach Based on Atmospheric Pressure Air Plasma

Fungal contamination of surfaces is a global burden, posing a major environmental and public health challenge. A wide variety of antifungal chemical agents are available; however, the side effects of the use of these disinfectants often result in the generation of toxic residues raising major environmental concerns. Herein, atmospheric pressure air plasma generated by a surface barrier discharge (SBD) is presented as an innovative green chemical method for fungal inactivation, with the potential to become an effective replacement for conventional chemical disinfection agents, such as Virkon. Using Aspergillus flavus spores as a target organism, a comparison of plasma based decontamination techniques is reported, highlighting their respective efficiencies and uncovering their underpining inactivation pathways. Tests were performed using both direct gaseous plasma treatment and an indirect treatment using a plasma activated aqueous broth solution (PAB). Concentrations of gaseous ozone and nitrogen oxides were determined with Fourier-transform infrared spectroscopy (FTIR) and Optical emission spectroscopy (OES), whereas hydrogen peroxides, nitrites, nitrates, and pH were measured in PAB. It is demonstrated that direct exposure to the gaseous plasma effluent exhibited superior decontamination efficiency and eliminated spores more effectively than Virkon, a finding attributed to the production of a wide variety of reactive oxygen and nitrogen species within the plasma.

Sensitivity of food spoilage fungi to a smoke generator sanitizer

Smoke generator sanitizers are easy to handle and can access to hard-to-reach places. They are a promising alternative for controlling food and air borne fungi, which are known to cause losses in the bakery, meat, and dairy industries. Therefore, the present study aimed to evaluate the efficiency of a smoke generator sanitizer based on orthophenylphenol against ten fungal species relevant to food spoilage. The tests were carried out according to the norms by the French protocol NF-T-72281, with adaptations specific for disinfectants diffused in the air. The tests were performed in an enclosed room of approximately 32 m³. Aspergillus brasiliensis (ATCC 16404), Candida albicans (ATCC 10231), Aspergillus flavus (ATCC 9643), Aspergillus chevalieri (IMI 211382), Cladosporium cladosporioides (IMI 158517), Lichtheima corymbifera (CCT 4485), Mucor hiemalis (CCT 4561), Penicillium commune (CCT 7683), Penicillium polonicum (NGT 33/12), and Penicillium roqueforti (IMI 217568) were exposed to the smoke generator sanitizer for 7 h. The product was efficient against C. albicans and C. cladosporioides, although it was unable to reduce 4 log of the other tested species. The variable sensitivity of the fungal species to the sanitizer emphasizes the importance of confronting a target microorganism (causing problems in a specific food industry) with the sanitizer aiming to control it and obtain satisfactory results in hygiene programs.

Novel approaches for chemical and microbiological shelf life extension of cereal crops

Economic losses due to post-harvest fungal spoilage and mycotoxin contamination of cereal crops is a frequently encountered issue. Typically, chemical preservatives are used to reduce the initial microbial load and the environmental conditions during storage are controlled to prevent microbial growth. However, in recent years the consumers' desire for more naturally produced foods containing less chemical preservatives has grown increasingly stronger. This article reviews the latest advances in terms of novel approaches for chemical decontamination, namely application cold atmospheric pressure plasma and electrolyzed water, and their suitability for preservation of stored cereal crops. In addition, the alternative use of bio-preservatives, such as starter cultures or purified antimicrobial compounds, to prevent the growth of spoilage organisms or remove in-field accumulated mycotoxins is evaluated. All treatments assessed here show potential for inhibition of microbial spoilage. However, each method encounters draw-backs, making industrial application difficult. Even under optimized processing conditions, it is unlikely that one single treatment can reduce the natural microbial load sufficiently. It is evident that future research needs to examine the combined application of several treatments to exploit their synergistic properties. This would enable sufficient reduction in the microbial load and ensure microbiological safety of cereal crops during long-term storage.

Diversity and Control of Spoilage Fungi in Dairy Products: An Update

Fungi are common contaminants of dairy products, which provide a favorable niche for their growth. They are responsible for visible or non-visible defects, such as off-odor and -flavor, and lead to significant food waste and losses as well as important economic losses. Control of fungal spoilage is a major concern for industrials and scientists that are looking for efficient solutions to prevent and/or limit fungal spoilage in dairy products. Several traditional methods also called traditional hurdle technologies are implemented and combined to prevent and control such contaminations. Prevention methods include good manufacturing and hygiene practices, air filtration, and decontamination systems, while control methods include inactivation treatments, temperature control, and modified atmosphere packaging. However, despite technology advances in existing preservation methods, fungal spoilage is still an issue for dairy manufacturers and in recent years, new (bio) preservation technologies are being developed such as the use of bioprotective cultures. This review summarizes our current knowledge on the diversity of spoilage fungi in dairy products and the traditional and (potentially) new hurdle technologies to control their occurrence in dairy foods.

Emergence of resistance to antibacterial agents: the role of quaternary ammonium compounds--a critical review

Quaternary ammonium compounds (QACs) are widely distributed in hospitals, industry and cosmetics. Little attention has been focused on the potential impact of QACs on the emergence of antibiotic resistance in patients and the environment. To assess this issue, we conducted a literature review on QAC chemical structure, fields of application, mechanism of action, susceptibility testing, prevalence, and co- or cross-resistance to antibiotics. Special attention was paid to the effects of QACs on microflora; in particular, the issue of the potential of QACs for applying selective pressure on multiple-antibiotic-resistant organisms was raised. It was found that there is a lack of standardised procedures for interpreting susceptibility test results. QACs have different impacts on the minimum inhibitory concentrations of antibacterials depending on the antibacterial compound investigated, the resistance genes involved, the measuring methodology and the interpretative criteria. The unmet needs for adequate detection of reduced susceptibility to QACs and antibiotics include (i) a consensus definition for resistance, (ii) epidemiological cut-off values and (iii) clinical resistance breakpoints. This review advocates the design of international guidelines for QAC use.

Does the wide use of quaternary ammonium compounds enhance the selection and spread of antimicrobial resistance and thus threaten our health?

Quaternary ammonium compounds (QACs) are widely used biocides that possess antimicrobial effect against a broad range of microorganisms. These compounds are used for numerous industrial purposes, water treatment, antifungal treatment in horticulture, as well as in pharmaceutical and everyday consumer products as preserving agents, foam boosters, and detergents. Resistance toward QACs is widespread among a diverse range of microorganisms and is facilitated by several mechanisms such as modifications in the membrane composition, expression of stress response and repair systems, or expression of efflux pump genes. Development of resistance in both pathogenic and nonpathogenic bacteria has been related to application in human medicine and the food industry. QACs in cosmetic products will inevitably come into intimate contact with the skin or mucosal linings in the mouth and thus are likely to add to the selection pressure toward more QAC-resistant microorganisms among the skin or mouth flora. There is increasing evidence of coresistance and cross-resistance between QACs and a range of other clinically important antibiotics and disinfectants. Use of QACs may have driven the fixation and spread of certain resistance cassette collectors (class 1 integrons), currently responsible for a major part of antimicrobial resistance in gram-negative bacteria. More indiscriminate use of QACs such as in cosmetic products may drive the selection of further new genetic elements that will aid in the persistence and spread of antimicrobial resistance and thus in limiting our treatment options for microbial infections.