Decontamination efficacy against Mycoplasma

Pathologists' perspective on the study design, analysis, and interpretation of proliferative lesions in a lifetime rodent carcinogenicity bioassay of sucralose

Sucralose, a sugar substitute first approved for use in 1991, is a non-caloric sweetener regulated globally as a food additive. Based on numerous experimental animal studies (dating to the 1980s) and human epidemiology studies, international health agencies have determined that sucralose is safe when consumed as intended. A single lifetime rodent carcinogenicity bioassay conducted by the Ramazzini Institute (RI) reported that mice fed diets containing sucralose develop hematopoietic neoplasia, but controversy continues regarding the validity and relevance of these data for predicting health effects in humans. The present paper addresses the controversy by providing the perspective of experienced pathologists on sucralose-related animal toxicity and carcinogenicity data generally, and the RI carcinogenicity bioassay findings specifically, using results from publicly available papers and international regulatory authority decisions. In the authors' view, flaws in the design, methodology, data evaluation, and reporting of the RI carcinogenicity bioassay for sucralose diminish the value of the data as evidence that this agent represents a carcinogenic hazard to humans. This limitation will remain until the RI bioassay is repeated under Good Laboratory Practices and the design, data, and accuracy of the pathology diagnoses and interpretations are reviewed by qualified pathologists with experience in evaluating potential chemically-induced carcinogenic hazards.

Efficacy and Safety of Inhalation of Nebulized Ethanol in COVID-19 Treatment: A Randomized Clinical Trial

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a pandemic caused by the SARS-CoV-2 virus. Many efforts have been made and are currently being made to prevent and treat this global disease.

OBJECTIVES

This study was designed to evaluate the efficacy and safety of nebulized ethanol (EtOH) in treating COVID-19.

METHODS

A randomized clinical trial (RCT) of 99 symptomatic and real-time polymerase chain reaction (RT-PCR)-positive patients admitted to a hospital receiving remdesivir-dexamethasone was conducted. They were randomly assigned to receive distilled water spray (control group (CG)) or 35% EtOH spray (intervention group (IG)). Both groups inhaled three puffs of spray (nebulizer) every six hours for a week. The primary outcome included Global Symptomatic Score (GSS) between the two groups at the first visit and on days three, seven, and 14. Secondary outcomes included the Clinical Status Scale (CSS; a seven-point ordinal scale ranging from death to complete recovery) and readmission rate.

RESULTS

A total of 44 and 55 patients were enrolled in the IG and CG, respectively. Although there was no difference at admission, the GSS and CSS improved significantly in the IG (p = 0.016 and p = 0.001, respectively). The IG readmission rate was considerably lower (0% vs. 10.9%; p = 0.02).

CONCLUSIONS

Inhaled-nebulized EtOH is effective in rapidly improving the clinical status and reducing further treatment. Due to its low cost, availability, and absent/tolerable adverse events, it could be recommended as an adjunctive treatment for moderate COVID-19. Further research on curative effects in more serious cases and in prevention is advisable.

Pathologists' perspective on the study design, analysis, and interpretation of proliferative lesions in lifetime and prenatal rodent carcinogenicity bioassays of aspartame

Aspartame, an artificial sweetener commonly used as a sugar substitute, is currently authorized for use in more than 100 countries. Hundreds of studies, conducted in various countries dating back to the 1970s, have shown that aspartame is safe at real-world exposure levels. Furthermore, multiple human epidemiology studies have provided no indication that consumption of aspartame induces cancer. Given the continued controversy surrounding the Ramazzini Institute's (RI) studies suggesting that aspartame is a carcinogenic hazard in rodents and evaluation by the International Agency for Research on Cancer, this report aims to provide the perspective of experienced pathologists on publicly available pathology data regarding purported proliferative lesions in liver, lung, lymphoid organs, and mammary gland as well as their implications for human risk assessment as reported for three lifetime rodent carcinogenicity bioassays of aspartame conducted at the RI. In the authors' view, flaws in the design, methodology and reporting of the RI aspartame studies limit the utility of the data sets as evidence that this agent represents a carcinogenic hazard. Therefore, all three RI studies, and particularly the accuracy of their pathology diagnoses and interpretations, should be rigorously reviewed by qualified and experienced veterinary toxicologic pathologists in assessing aspartame's carcinogenic risk.

The rationale of ethanol inhalation for disinfection of the respiratory tract in SARS-CoV-2-positive asymptomatic subjects

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic is a major health concern and is affecting the socio-economic lives. As other highly contagious diseases, it is of outmost importance to early identify and treat the healthy carriers or positive asymptomatic subjects (PAS). SARS-CoV-2 entry points are mainly in the respiratory tract. No specific virucidal treatments against SARS-CoV-2 are currently available. Monoclonal antibodies are under evaluation, but high cost and possible ineffectiveness against virus variants could limit its use. Resorting nonspecific drugs is an alternative approach. Among them, ethanol (EtOH) is known to be a powerful, cost-effective and abundant virucidal agent, now advised for surgical hand and surfaces disinfection. The paper aims to determine the potential role of inhaled ethanol to disinfect SARS-CoV-2 PAS, taking into account the dimension of the problem, ethanol efficiency and other beneficial effects on the respiratory tract, ethanol local and general toxicity and ethanol therapeutic window; consequently, to propose a study in order to verify this hypothesis. Together with the consolidated knowledge, an extensive review of the medical literature has been carried out looking for sound data able to support (or discard) the rationale on which a study could be built up. Evident data supporting the inhaled ethanol potential role on SARS-CoV-2 PAS disinfection have been found and discussed. A clinical trial to test the hypothesis that inhaled ethanol could be rapidly efficient in lowering or eradicating SARS-CoV-2 from the respiratory tract in PAS is advisable. Individual and public health benefits are stressed, together with socio-economic positive fallouts.

Detection of Mycoplasma agalactiae in Ticks (Rhipicephalus bursa) Collected by Sheep and Goats in Sicily (South-Italy), Endemic Area for Contagious Agalactia

The aim of this preliminary study was to investigate the presence of Mycoplasma agalactiae (Ma) or other Contagious Agalactia (CA) causative organisms, in hard ticks infesting milking sheep and goats in endemic areas for CA in Sicily (South-Italy). Although there is accumulating evidence to support the role of ticks in the transmission of blood-borne haemoplasmas, information regarding their role in the transmission of CA, remains scarce. Ticks (n = 152) were collected from 25 lactating sheep and goats from three farms with previous outbreaks of CA. Microbiological and biomolecular, as well as serological analysis were performed on milk, tick, and serum samples, respectively. Rhipicephalus bursa species predominated, comprising 84.8% of the sampled ticks. Mycoplasma-like colonies were isolated from 5/56 (8.9%) tick pools and were identified as Ma by specific PCR and 16S rRNA gene sequencing. Unexpectedly, the organism was isolated from R. bursa ticks recovered only from animals whose milk tested negative for the pathogen. This preliminary demonstration suggests the potential role for ticks to act as a reservoir for the organisms, with potential involvement in the spread and maintenance of CA. Further work is required to determine the location of the organisms within the body of the ticks and to assess transmission potential.

A practical approach for gmp-compliant validation of real-time PCR method for mycoplasma detection in human mesenchymal stromal cells as advanced therapy medicinal product

BACKGROUND

Manufacturing of human Mesenchymal Stromal Cells as advanced therapy medicinal product (ATMP) for clinical use involves an ex vivo expansion, which leads to a risk of contamination by microbiological agents. Even if manufacturing under Good Manufacturing Practice (GMP) license minimizes this risk, contamination of cell cultures by mycoplasmas still represents a widespread problem. Furthermore, the absence of mycoplasma contamination represents one of ATMPs release criteria. Since July 2007, European Pharmacopoeia (EuPh) offers the possibility to replace official mycoplasma detection methods with Nucleic Acid Amplification techniques, after suitable validation. As an Italian authorized Cell Factory, we developed an in-house GMP-compliant validation of real-time PCR method for mycoplasma detection in human Mesenchymal Stromal Cells, according to EuPh sec. 2.6.7 and International Conference on Harmonization Q₂.

MATERIALS AND METHODS

The study was performed in compliance with GMP international requirements with MycoSEQ™ Mycoplasma Detection Assay (Thermofisher) on QuantStudio5 real-Time PCR (Applied Biosystems). Assay validation was developed to evaluate sensitivity, interferences matrix-related, specificity and robustness.

RESULTS

MycoSEQ™ Mycoplasma Detection Assay has been successfully validated on human Mesenchymal Stromal Cells as results comply with validation protocol acceptance criteria.

CONCLUSIONS

MycoSEQ™ Mycoplasma Detection Assay is a fast, sensitive and specific PCR-based Nucleic Acid Test assay that can be used as an alternative to official mycoplasma test methods for lot release of human Mesenchymal Stromal Cells as advanced therapy medicinal product (ATMP). Moreover, our study underlines the presence of interference on real-time PCR reaction due to matrix composition, pointing out a practical approach for method validation (i.e interference removal).

A Systematic Review on the Efficacy of Vaporized Hydrogen Peroxide as a Non-Contact Decontamination System for Pathogens Associated with the Dental Environment

Aerosol generation and a wide range of pathogens originating from the oral cavity of the patient contaminate various surfaces of the dental clinic. The aim was to determine the efficacy of vaporized hydrogen peroxide fogging on pathogens related to the dental environment and its possible application in dentistry. PICOS statement (Population, Intervention, Comparison/Control, Outcome and Study design statement) was used in the review. Six electronic databases were searched for articles published from 2010 to 2020. Articles written in English reporting vaporized hydrogen peroxide on pathogens deemed to be relevant to the dental environment were assessed. The quality of the studies was assessed using the risk-of-bias assessment tool designed for the investigation of vaporized hydrogen peroxide application in dentistry. A total of 17 studies were included in the qualitative synthesis. The most commonly reported single bacterial pathogen was Methicillin-resistant Staphylococcus aureus in five studies, and the viruses Feline calicivirus, Human norovirus, and Murine norovirus were featured in three studies. The results of the studies reporting the log kill were sufficient for all authors to conclude that vaporized hydrogen peroxide generation was effective for the assessed pathogens. The studies that assessed aerosolized hydrogen peroxide found a greater log kill with the use of vaporized hydrogen peroxide generators. The overarching conclusion was that hydrogen peroxide delivered as vaporized hydrogen peroxide was an effective method to achieve large levels of log kill on the assessed pathogens. The hydrogen peroxide vapor generators can play a role in dental bio-decontamination. The parameters must be standardized and the efficacy assessed to perform bio-decontamination for the whole clinic. For vaporized hydrogen peroxide generators to be included in the dental bio-decontamination regimen, certain criteria should be met. These include the standardization and efficacy assessment of the vaporized hydrogen peroxide generators in dental clinics.

Examination of Material Compatibilities with Ionized and Vaporized Hydrogen Peroxide Decontamination

Hydrogen peroxide (HP) decontamination is effective for a wide spectrum of pathogenic microorganisms. However, exposure to HP causes deleterious effects on some materials. The purpose of this study was to examine material compatibilities with ionized and vaporized hydrogen peroxide (iHP and VHP). With regard to iHP, 24 kinds of materials were exposed up to 100 cycles to iHP. The tested materials included plastics, metals, woods and plated or coated goods. The procedure of iHP decontamination was as following: gas time (11 min), dwell time (15 min) and aeration time (120 min). iHP decontamination caused some damage to copper, brass, chromium plate and galvanized iron immediately after exposure. Repeated iHP decontamination caused marked damage in stainless steel and urethane-, silicone- or epoxy-coating materials. Condensation of iHP decontamination posed severe damage for the material surfaces. With regard to VHP, 36 kinds of materials were exposed for up to 200 cycles to VHP decontamination. Under dry (dehumidified) conditions, VHP decontamination caused few changes on the surfaces of resin materials in dry conditions, although some resins began to develop hardening or softening. Discoloration was found in the stainless steel and changes in its coating materials. Bleaching was also observed in wooden materials. Under condensation conditions of VHP, nylon softened and butyl rubber hardened. Condensation of VHP caused material damage such as discoloration in the stainless steel, corrosion of zinc-plated steel, and air-bubbling under the color-steel sheet. The high concentrations of HP with condensation caused severe changes in metals and resins after repeated exposure. The VHP decontamination tests provided evidence that the material damage was more severe under condensation conditions than under dry conditions. Our results demonstrate the importance of condensation of HP when using it to decontaminate equipment.

Contagious Agalactia In Sheep And Goats: Current Perspectives

Contagious agalactia (CA) is a disease caused equally by four Mycoplasma species, in single or mixed infections. Clinical signs are multiple, including mastitis, arthritis, keratoconjunctivitis, pneumonia, and septicemia, non-specific, and expressed differently depending whether sheep or goats are affected, on causative mycoplasmas as well as type of husbandry. CA has been reported worldwide and its geographic distribution maps to that of small ruminant breeding areas. However, as current diagnostic tests are expensive and difficult to implement, it is certainly underdiagnosed and prevalence data are only available for a few countries. CA control relies on vaccines, chemotherapy and good herd management practices. It requires long-term commitment but is often unsuccessful, with frequent clinical relapses. The persistence of the etiological agents, despite their overall susceptibility to antimicrobials, comes from their genetic plasticity and capacity to escape the host immune response. The existence of asymptomatic carriers and the numerous sources of infections contribute to rapid spread of the disease and complicate the control and prevention efforts. Here we review all these aspects in order to highlight recent progress made and identify gaps in knowledge or tools needed for better disease management. Discussion also underlines the detrimental effect of contagious agalactia on small ruminant welfare.

Antimicrobial resistance in mollicutes: known and newly emerging mechanisms

This review is devoted to the mechanisms of antibiotic resistance in mollicutes (class Bacilli, subclass Mollicutes), the smallest self-replicating bacteria, that can cause diseases in plants, animals and humans, and also contaminate cell cultures and vaccine preparations. Research in this area has been mainly based on the ubiquitous mollicute and the main contaminant of cell cultures, Acholeplasma laidlawii. The omics technologies applied to this and other bacteria have yielded a complex picture of responses to antimicrobials, including their removal from the cell, the acquisition of antibiotic resistance genes and mutations that potentially allow global reprogramming of many cellular processes. This review provides a brief summary of well-known resistance mechanisms that have been demonstrated in several mollicutes species and, in more detail, novel mechanisms revealed in A. laidlawii, including the least explored vesicle-mediated transfer of short RNAs with a regulatory potency. We hope that this review highlights new avenues for further studies on antimicrobial resistance in these bacteria for both a basic science and an application perspective of infection control and management in clinical and research/production settings.