Prevalence of Bacillus cereus in food products in Poland

INTRODUCTION AND OBJECTIVE

Bacillus cereus is a foodborne pathogen causing two main types of gastrointestinal diseases: emetic and diarrheal. The aim of this study was to investigate the prevalence of the Bacillus cereus group in ready-to-eat (RTE) food products available in retail in Poland.

MATERIAL AND METHODS

Samples were collected by Sanitary and Epidemiological Stations within the framework of the national official control and monitoring sampling programme in Poland. In 2016-2020, a total of 45,358 food samples, such as: 'confectionery products and products with cream', as well as 'cereal grains and cereal and flour products', 'milk and milk products', 'sugar and others', 'meat offal and meat products', 'poultry offal and poultry products', 'eggs and egg products', 'fish, seafood and their preserves', 'vegetables' (including legumes), 'coffee, tea, cocoa, fruit, and herbal teas', 'delicatessen and culinary products', and 'foods for particular nutritional uses' were collected.

RESULTS

The presence of the presumptive B. cereus group was monitored mainly in two categories of food products: 'confectionery products and products with uncooked cream' and 'confectionery products and products with heat-treated cream'. The number of samples disqualified due to presumptive B. cereus was 339 (0.75%).

CONCLUSIONS

This study provides useful information regarding the contamination of RTE products with the B. cereus group, which may have implications for food safety.

The efficiency of nuisance relief by filtering facepiece respirators used by workers exposed to agricultural odours

BACKGROUND

The study aimed to evaluate the effectiveness of filtering facepiece respirators (FFRs) in reducing odour nuisances in agricultural work environment. Additionally, an assessment was conducted on the microbiological contamination of FFRs and the functionality of Time4Mask application in enhancing workplace safety.

MATERIAL AND METHODS

Two types of FFRs were used for the study: with absorbing properties and reference ones. The research was carried out in 6 livestock rooms during a 1-week period in early spring (February-March 2021) on a farm in central Poland. The microclimate conditions (thermoanemometer), and particulate matter concentrations (laser photometer) were assessed. Additionally, the odour content in the studied rooms and the breathing zone of FFR users (gas chromatography with mass spectrometry) were evaluated. The number of microorganisms on the respirators was determined (cultivation method), followed by their identification (biochemical tests, taxonomic keys). Breakthrough curves were determined for both FFR types to assess absorption capabilities.

RESULTS

The average temperature in the livestock rooms was about 13°C, relative humidity - 53%, air flow velocity - 0.21 m/s, and particulate matter concentration - 0.216 mg/m3. A significant variety of odorants was found in the environment and the breathing zone under the FFRs. Bacterial counts ranged between 2.4 × 101 and 2.6 × 102 CFU/cm2, fungi between 3.2 × 100 and 5.4 × 101 CFU/cm2, xerophilic fungi from 4.4 × 100 to 4.0 × 101 CFU/cm2, mannitol-positive staphylococci between 1.6 × 101 and 1.0 × 102 CFU/cm2, and haemolytic staphylococci from 2.2 × 101 to 4.5 × 101 CFU/cm2, depending on the respirator type. Respirators were colonized by bacteria from the genera: Bacillus, Staphylococcus, actinobacteria Streptomyces sp., and fungi: Candida, Absidia, Aspergillus, Mucor, and Penicillium. Respirators with absorbing properties had over 8-times longer breakthrough time than reference ones.

CONCLUSIONS

Respirators with activated carbon effectively improved work comfort when exposed to odours. Due to growth of microorganisms in the respirator materials, periodic replacement is necessary. It is crucial to provide workers with information about the safe-use time of respirators, considering environmental conditions. This is achievable using modern IT tools like Time4Mask application. Med Pr Work Health Saf. 2023;76(5):363-75.

Studies of the origin, composition and microbiological contamination of old museum collections

Anatomical museums preserve specimens of great historical value and undiscovered scientific potential. However, frequently these collections lack documentation of the techniques of preparation and the composition of preservative substances (conservation principles). This poses a huge problem for the care and preservation of these materials, more so because understanding this issue requires knowledge of fundamentals from different scientific disciplines. The aim of the research was to obtain information about the composition of substances used to preserve historic specimens, as well as to conduct a microbiological assessment of the specimens to detect possible factors causing their deterioration. Furthermore, we wanted to fill an existing gap in the literature, as there is a lack of reports on analytical methods that could be successfully applied by anatomists involved in the daily care of museum collections in human anatomy departments. The starting point was the analysis of the sources and history of the collections, on which basis the choice of research methods was made. Methods based on simple chemical reactions and specialised methods (such as gas chromatography-tandem mass spectrometry, Fourier transform infrared spectroscopy, inductively coupled plasma optical emission spectroscopy) were used in the analyses of the composition of fluids. Microbiological analyses were based on culture and isolation methods, analysis of microscopy slides and matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry analysis. As a result of these analyses, some components of the preservative mixtures and their concentrations were determined. The presence of methanol, ethanol, formaldehyde and glycerol was detected, among other chemicals. The concentrations of these substances were different between the samples and their determination required the use of a variety of methods suitable for the individual components of the preservative mixture. In microbiological tests, both bacteria and fungi were isolated from swabs taken from anatomical specimens. The bacterial flora was less numerous than the fungal flora. Among the bacteria, environmental Gram-positive Bacillus cereus, Bacillus thuringiensis and a rare bacterium of the Cupriavidus genus were isolated, whereas among the fungal organisms, the yeast-like fungi Candida boidinii and Geotrichum silvicola as well as mould fungi Penicillium sp. and Fusarium sp. were detected. However, the microscopic evaluation showed a greater diversity of microorganisms, which may be related to the fact that many environmental bacteria cannot be cultured using classical methods, but can be observed under the microscope. The results of the research made it possible to draw conclusions about the mutual influence of physical, chemical, and microbiological factors on the condition of historical anatomical specimens. In the course of the research, information was obtained on the processes which could have taken place during the storage of these collections. Maintaining the integrity of a container housing a preserved anatomical specimen has a major impact on maintaining the concentration of preservative fluid and keeping the specimen environment sterile. Many conservation procedures for historical specimens carried out nowadays pose a risk of destroying valuable specimens, as well as a health risk for the person carrying out the work. The exploration of the topic of conservation of anatomical specimens, especially those that lack documentation of their origin, is a key issue in current research on historical collections of anatomical specimens.

Continuous Control of Microbiological Contamination of Juice in a Sugar Extractor

The paper discusses the causes and needs of controlling the level of microbiological contamination of juice in a vertical extractor and the methods to control the level of contamination. The requirements and possibilities for controlling the microbiological contamination level of juice extracted from the vertical extractor are described using redox potential value measurement. Aerating the extractor in a controlled manner, regulating the pH level of the juice, and implementing one of the presented proposals on how to record the measurement results will automatically regulate microbiological contamination levels of the juice in the tower extractor.

Potential Risk of Botulinum Neurotoxin -producing Clostridia Occurrence in Canned Fish

Introduction

Heat treatment is indispensable in fish canning to provide an acceptable shelf life. Its optimisation reduces the risk of the presence of Clostridium botulinum spores, which could potentially cause botulism cases. This study evaluated canned fish samples for botulism neurotoxin (BoNT)-producing clostridia contamination and can bulging through microbiological contaminant growth. A new analytical approach was developed for detection of such clostridia and phenotypically similar species.

Material and Methods

A total of 70 canned fish samples suspected of exhibiting bulging features were analysed. Culture methods were used to detect clostridia. The isolates obtained were evaluated on the basis of the exhibited phenotypic characteristics. Also, PCRs were used for the detection of genes determining BoNT production (non-toxic non-haemagglutinin (ntnh) genes) and the amplification of conservative 16S rDNA genes, which were Sanger sequenced. The obtained sequences were analysed using the Basic Local Alignment Search Tool.

Results

Clostridium genus species were isolated from 17 (24%) bulging and organoleptically changed samples. No ntnh genes were present in these isolates; however, sequencing confirmed the presence of C. sporogenes, a species with close affinity to C. botulinum.

Conclusion

To eliminate the threat of foodborne botulism, laboratory diagnostic techniques must detect species of the Clostridium genus and elucidate their ability to produce BoNTs. Although Clostridium botulinum is the most common cause of botulism, the possibility may not be ignored that non-pathogenic Clostridium species may acquire botulinum toxigenicity. The similarity between the isolated strains of C. sporogenes and C. botulinum should be incorporated in the optimisation of heat treatment to guarantee a sterilised, microbiologically safe product.

Food Safety Issues Related to Eating In and Eating Out

Because of growing urbanization and lack of time to prepare meals at home, eating out or getting food delivered have become common trends for many people. The consumption of food from unknown sources may impose an increased chance of contamination with microbiological hazards, especially if sanitary conditions are not met. We evaluated data from health surveillance agencies and scientific articles on foodborne diseases (FBD) reported internationally according to the exposure sites. We observed that the data are influenced by cultural, political, and socioeconomic differences. For instance, in New Zealand, Australia, United States, Denmark and India, the occurrence of FBD outbreaks was greater from foods prepared in commercial establishments and street vendors than from households. Conversely, in China, countries of the European Union and Brazil, the results are the opposite. Additionally, the pandemic imposed new eating behavior patterns, increasing delivery services and foods prepared in so-called "Dark Kitchens". The underreporting and heterogeneity of data among countries prevented a precise conclusion to the question of whether homemade foods are inherently safer than foods prepared out. Nevertheless, a lower level of development in a country influences its sanitation conditions, as well as the number of street food vendors, the search for cheaper foods, and insufficient knowledge of the population on good hygiene practices, which can all increase the chances of FBD cases.

Bacteriological Quality and Public Health Risk of Ready-to-Eat Foods in Developing Countries: Systematic Review and Meta Analysis

Background:

Ready-to-eat foods are foods that are consumed at the point of sale or later, without any further processing or treatment. Foodborne diseases are on the rise worldwide, involving a wide range of diseases caused by pathogenic bacteria, and are becoming a public health problem. Therefore, this study sought to identify and determine the bacteriological quality and public health risks in ready-to-eat foods in developing countries.

Methods:

The studies published from 2012 to 2020 were identified through systematic searches of various electronic databases such as Google Scholar, PubMed and MEDLINE, MedNar, EMBASE, CINAHL, Scopus, and Science Direct. The articles were searched using a Boolean logic operator (“AND,” “OR,” “NOT”) combination with Medical Subject Headings (MeSH) terms and keywords. All identified keywords and an index term were checked in all included databases. In addition, a quality assessment is performed to determine the relevance of the article, and then the data are extracted and analyzed.

Results:

The current study found that the pooled prevalence of Staphylococcus aureus, Enterobacter species, Klebsiella, Escherichia coli, Salmonella, Bacillus cereus, Pseudomonas species, and Shigella in ready-to-eat foods was 30.24% (95% CI: 18.8, 44.65), 11.3% (95% CI: 6.6, 18.7), 9.1% (95% CI: 7.0, 11.8), 23.8% (95% CI: 17.5, 31.5), 17.4% (95% CI: 11.6, 25.31)], 26.8% (95% CI: 13.7, 45.9), 6.1% (95% CI: 2.8, 12.6), 34.4% (95% CI: 18.1-55.4), respectively.

Conclusions:

Most of the reviewed articles reported on various pathogenic bacterial species that are potentially harmful to human health, such as Staphylococcus aureus, Salmonella, Shigella, and Escherichia coli in ready-to-eat food above the maximum allowable limit. Therefore, relevant national and international organizations must take corrective measures to prevent foodborne diseases and protect human health.

Differences in microbiological quality of leafy green vegetables

OBJECTIVE

The aim of the study was to determine the presence and concentration of indicator microorganisms on leafy green vegetables available in Poland.

MATERIAL AND METHODS

Microbial analyses of 122 samples of leafy green vegetables: rocket, lamb's lettuce, iceberg lettuce, chive, spinach, celery, dill and parsley, sold in Polish supermarkets in 2018 and 2019, were conducted. The vegetables were analyzed for aerobic mesophilic bacteria, yeasts and moulds, Enterobacteriaceae, Enterococcus, coliforms and Escherichia coli number according to Polish standards.

RESULTS

The most microbiologically contaminated vegetables occurred to be parsley, rocket and spinach, and the least contaminated was iceberg lettuce. The presence of total mesophilic bacteria was found in all samples. The highest average number of mesophilic bacteria was found for lamb's lettuce, rocket, parsley and spinach. Numerous yeasts were presented in almost all leafy green samples while rocket and parsley were the most contaminated with moulds. Enterobacteriaceae were isolated from all samples of parsley. High populations of these bacteria were found in rocket and celery samples. Of the 122 vegetable samples, 95 (78%) were positive for coliforms, especially all samples of parsley were inhabited by these bacteria. 24% of all samples were contaminated by Enterococcus, mainly parsley, spinach and chive. The presence of E. coli was found in only one sample of spinach.

CONCLUSIONS

The levels of aerobic mesophilic bacteria, yeasts and moulds, Enterobacteriaceae, Enterococcus and coliforms in leafy green vegetables sold in Poland could be classified as moderate or low. The abundant presence of the studied microorganisms may pose a risk for some categories of people consuming leafy green vegetables, mostly immuno-compromised persons.

Microbial Contamination and Public Health: An Overview

Food contamination with microbial agents can take place at any stage of the food chain, from farm to fork. For this reason, good hygienic and manufacturing practices must be followed along the entire food chain to prevent microbiological food contamination due to microbes which can cause high incidence of morbidity and mortality among consumers. Recent research have been focused on the implementation of innovative technologies for enhancing the quality and safety of food without compromising its organoleptic and nutritional characteristics. Studies should be addressed to the development of simple, less expensive, and fast tests for monitoring and controlling microbial food contamination, as well as to the development of new food manufacturing processes.

The potential application of supercritical CO2 in microbial inactivation of food raw materials and products

The purpose of this study was to review the possibility of using supercritical CO₂ as a green and sustainable technology for microbial inactivation of raw material for further application in the food industry. The history of the development of supercritical CO₂ microbial inactivation has been widely described in this article. The fundamental scientific part of the process like mechanism of bactericidal action of CO₂ or inactivation of key enzymes were characterized in detail. In summary, this study provides an overview of the latest literature on the use of supercritical carbon dioxide in microbial inactivation of food raw materials and products.

Operating Theatre Ventilation Systems and Their Performance in Contamination Control: "At Rest" and "In Operation" Particle and Microbial Measurements Made in an Italian Large and Multi-Year Inspection Campaign

In Operating Theatres (OT), the ventilation system plays an important role in controlling airborne contamination and reducing the risks of Surgical Site Infections (SSIs). The air cleanliness is really crucial in this field and different measurements are used in order to characterize the situation in terms of both airborne microbiological pollutants and particle size and concentration. Although the ventilation systems and airborne contamination are strictly linked, different air diffusion schemes (in particular, the Partial Unidirectional Airflow, P-UDAF, and the Mixing Airflow, MAF) and various design parameters are used, and there is still no consensus on real performance and optimum solutions. This study presents measurements procedures and results obtained during Inspection and Periodic Performance Testing (1228 observations) in a large sample of Italian OTs (175 OTs in 31 Italian hospitals) in their operative life (period from 2010 to 2018). The inspections were made after a cleaning procedure, both in “at-rest” conditions and “in operation” state. Inert and microbial contamination data (in air and on surfaces) are analyzed and commented according to four relevant air diffusion schemes and design classes. Related data on Recovery Time (RT) and personnel presence were picked up and are commented. The results confirm that the ventilation systems are able to maintain the targeted performance levels in the OT operative life. However, they attest that significant differences in real OT contamination control capabilities do exist and could be ascribed to various design choices and to different operation and maintenance practices. The study shows and confirms that the air diffusion scheme and the design airflow rate are critical factors. Beside large variations in measurements, the performance values, in terms of control of airborne particle and microbial contamination (in air and on surfaces), for P-UDAF systems are better than those that were assessed for the MAF air diffusion solution. The average performances do increase with increasing airflows, and the results offer a better insight on this relationship leading to some possible optimization.

Quality of Dietary Supplements Containing Plant-Derived Ingredients Reconsidered by Microbiological Approach

Dietary supplements cover a wide range of products, the most popular are those containing plant-based ingredients. Supplements are consumed by consumers of all ages as well as by both healthy and sick people. The lack of unified regulation in this sector increases the probability that supplements are poor chemical and microbiological quality and can be dangerous for patients. The aim of this paper is to highlight selected issues associated with the microbiological quality of dietary supplements containing plant materials. We focus on the most recent reports referring to bacterial and fungal contaminations as well as the presence of mycotoxins. Dietary supplements containing plant ingredients commonly show a variety of microbial contaminants, which might be crucial for consumer safety. They often contain microorganisms potentially pathogenic to humans. Metabolites produced by microorganisms may pose a threat to the health of consumers. Because of that, in this review, we emphasize the risk that may be associated with the lack of appropriate studies of the quality of the supplements.

Microbiological and Chemical Quality of Portuguese Lettuce-Results of a Case Study

In addition to environmental pollution issues, social concerns about the sustainability, safety, and quality of conventionally grown fruits and vegetables have been increasing. In order to evaluate if there were any microbiological differences between samples of organic and conventional lettuce, a wide range of parameters were tested, including pathogens and indicator organisms: the enumeration of Escherichia coli; the detection of Salmonella spp.; the detection/enumeration of Listeria monocytogenes; the enumeration of lactic acid bacteria, Pseudomonas spp. yeasts and molds, and Enterobacteriaceae. This study also evaluated the chemical safety of the lettuce samples, quantifying the nitrate concentration and 20 pesticides (14 organochlorine and 6 organophosphorus pesticides). Significant differences (p < 0.05) between the conventional and organic samples were only detected for the counts of total microorganisms at 30 °C. Pathogens were absent in all the samples. The analytical method, using the quick, easy, cheap, effective, rugged, and safe (QuEChERS) approach for pesticide extraction, was suitable for detecting the targeted analytes; the limit of quantification (LOQ) was between 0.6 and 1.8 µg/kg (lower than the Maximum Residue Levels (MRLs) established by EU legislation). In three organic lettuce samples, one organochlorine pesticide (α-HCH) was observed below the MRLs. For the samples analyzed and for the parameters investigated, except for the total mesophilic counts, the organic and conventional lettuces were not different.

Assessment of the physicochemical characteristics, chemical and microbiological safety of two types of kilichi, a grilled meat produced in Niger

Production of kilichi, a grilled meat of West Africa, is a common method of meat preservation in Niger. Thirty samples of condiments-coated kilichi and uncoated kilichi collected in Niger, were analyzed for microbiological contamination, as well as NaCl, protein and lipid contents, using standard methods. Contamination with Polycyclic Aromatic Hydrocarbons (PAHs) was also assessed using a HPLC-FLD technique. Highly significant differences (p < .001) were observed between coated kilichi and uncoated kilichi, for NaCl content (2.56% and 1.40%), for proteins (51% and 72%) and lipids (18% and 13%), respectively. Water activity was low in both kilichi, showing a potential microbial stability. Among the 15 European Union (EU) priority PAHs, 12 were detected in the samples. About 56.3% of coated kilichi samples exceeded the EU maximal limit for BaP, and 75% exceeded the EU maximal limit for the sum of 4 PAHs (PAH4). For uncoated kilichi, 28.6% of samples did not meet the standards for BaP and PAH4. About 6% of coated kilichi samples were not compliant with standards related to Staphylococcus aureus, Bacillus cereus, Clostridium perfringens, and 31%, 50% for yeasts and fungi, respectively. Escherichia coli and Enterobacteria were below the detection limit in both kilichi, but Salmonella and Bacillus cereus were detected only in one coated kilichi. The noncompliant samples of uncoated kilichi were in the proportions varying between 7% -86% for S. aureus, C. perfringens, yeasts, and fungi. This study showed potential risks associated with the consumption of traditionally produced kilichi in Niger due to both PAHs and pathogen bacteria contamination.

Laundry and textile hygiene in healthcare and beyond

The elimination of microbial contaminations from textile is an important aspect of laundering apart from the removal of stains and dirt from used and worn textiles. Although the framework for institutional laundering is well regulated to ensure hygienic cleanliness via the use of e.g. high temperatures and bleaching agents, there are several open points, especially in domestic laundering. In both cases, energy efficiency of appliances is a main driver for innovation and has resulted in a general decrease in washing temperatures which in turn can impact the antimicrobial efficacy of laundering. Thus, the different factors influencing the input and removal of microbial cells in the laundering process and possible adverse effects of microbial contaminants in the washing machine and on the textiles as well as suitable counteractions are discussed in this article, focusing on the clinical area but also considering the domestic environment, which will gain importance in the future, e.g. by the increase of elderly and ill persons being cared for at home.

Different Trends in Microbial Contamination between Two Types of Microfiltered Water Dispensers: From Risk Analysis to Consumer Health Preservation

The use of microfiltered water dispensers (MWDs) for treatment of municipal water is increasing rapidly, however, the water quality produced by MWDs has not been widely investigated. In this work a large-scale microbiological investigation was conducted on 46 MWDs. In accordance with Italian regulations for drinking water, we investigated the heterotrophic plate counts at 36 and 22 °C for indicator bacteria and pathogenic bacteria, such as Enterococci, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus. Two different MWDs were compared: Type A with Ag⁺ coated carbon filter and two ultraviolet (UV) lamps, and Type B with a carbon filter and one UV lamp. For each type, the contamination of the input and output points was analyzed. Our findings showed that MWDs are a source of bacteria growth, with output being more contaminated than the input point. Type B was widely contaminated for all parameters tested in both sampling points, suggesting that water treatment by Type A is more effective in controlling bacterial contamination. MWDs are critical devices for water treatment in term of technologies, intended use, and sanitization procedures. The adoption of an appropriate drinking water safety plan associated with clear maintenance procedures and periodic environmental monitoring can ensure the safe and healthy operation of these devices.

Evaluation of Heavy Metals and Microbiological Contamination of Selected Herbals from Palestine

BACKGROUND

Herbal medicine is widely used for the prevention and treatment of diseases worldwide including Palestine and may require long term usage. The level of some heavy metals and microbial contaminants in some of these medicinal plants consumed by Palestinians were studied in order to evaluate their quality.

METHODOLOGY

The level of metals including: Zinc, Cadmium, Lead and Copper were quantified by Atomic absorption spectroscopy (AAS). Moreover, the bacterial and fungal contaminations were tested for some of the selected plants in Palestine. The procedures of microbial and elemental testing of the plants followed USP.

RESULTS

The result of the heavy metals testing showed that copper and cadmium were above the allowable limits in all the tested plants. Zinc metal was above the allowable limit in 78.9% of the tested samples. The microbiological results of the tested plants showed that 63.2% of the tested plants were contaminated by bacteria and 89.5% were contaminated by yeast.

CONCLUSIONS

Herbal medicine used in the Palestinian markets doesn't meet the international requirement for heavy metal and microbiological limits. Therefore, urgent action has to be taken by the responsible authorities including the Ministry of health to implement importation and registration requirements and perform regular quality checks of sold and imported herbal medicines. Pharmacists as expert professionals must take an active role in selling and advising consumers about the quality and efficacy of the sold plants.

Effects of Water Quality and Post-Harvest Handling on Microbiological Contamination of Lettuce at Urban and Peri-Urban Locations of Ouagadougou, Burkina Faso

Vegetable production in urban gardens of Ouagadougou contributes to food security, but water for irrigation is often of low quality. This is particularly acute if irrigation water is taken from wastewater polluted channels. This study aimed at (i) verifying to what degree irrigation water quality is correlated with contamination of lettuce with Escherichia coli, total coliforms, and Salmonella spp., and (ii) assessing effects of post-harvest handling on pathogen development during the trade chain. We tested pathogen removal efficiency on lettuce by applying post-harvest washing. Irrigation water of production areas in Ouagadougou (n = 10) showed a mean E. coli load of 2.1 × 10⁵ CFU 100 mL⁻¹. In 60% of the cases, irrigation water did not meet the standards of the World Health Organization (WHO) for safe irrigation water, and in 30% of the cases, irrigation water was contaminated with Salmonella spp. Loads of total coliforms on lettuce leaves ranged from 2.9 × 10³ CFU g⁻¹ to 1.3 × 10⁶ CFU g⁻¹, while E. coli averaged 1.1 × 10² CFU g⁻¹. Results on post-harvest handling revealed that microbial loads increased along the trade chain. Overall, half of all lettuce samples (n = 60) were tested positively for Salmonella spp. The experiment showed that appropriate post-harvest handling could prevent the increase of total coliforms.

Microbiological monitoring of heater-cooler unit to keep free of Mycobacterium chimaera infection

INTRODUCTION

The association of Mycobacterium chimaera infection in patients undergoing cardiopulmonary bypass (CPB) with the use of heater-cooler units (HCU) has been reported in various literature. We described microbiological monitoring and the extent of microbiological contamination of HCUs utilized in our centre and strategies employed to reduce the high microbial load.

METHODS

Since August 2016, we have been following the new Instructions for Use from the manufacturer for the cleaning and disinfection of three units of Stöckert 3T and four units of Stöckert 1T HCU at the National Heart Centre Singapore. Microbiological monitoring began in January 2017 and included acid-fast bacilli (AFB) culture, Pseudomonas aeruginosa, total colony and total coliform count. Methods, such as increasing disinfection frequency and making the HCU inactive by keeping it empty in storage, were used to reduce the high colony count.

RESULTS

All three units of Stöckert 3T and two units of Stöckert 1T were contaminated with Mycobacterium chimaera. Pseudomonas aeruginosa and total coliform count were consistently <1 colony-forming unit (CFU)/100 mL in every water sample of each HCU. High colony counts were encountered initially in all units. Step-up frequency of disinfection was found to be not as effective as keeping the HCU inactive in bringing the total colony count to an acceptable level.

CONCLUSIONS

All monitoring and maintenance measures of HCUs need to be established and maintained to mitigate potential infection risks to patients. Strict adherence to all cleaning and disinfection processes and keeping the HCU inactive maintained the water quality of the HCU at acceptable levels.

Surveillance of Environmental and Procedural Measures of Infection Control in the Operating Theatre Setting

The microbiological contamination of operating theatres and the lack of adherence to best practices by surgical staff represent some of the factors affecting Surgical Site Infections (SSIs). The aim of the present study was to assess the microbiological quality of operating settings and the staff compliance to the SSI evidence-based control measures. Ten operating rooms were examined for microbiological contamination of air and surfaces, after cleaning procedures, in “at rest” conditions. Furthermore, 10 surgical operations were monitored to assess staff compliance to the recommended practices. None of the air samples exceeded microbiological reference standards and only six of the 200 surface samples (3.0%) were slightly above recommended levels. Potentially pathogenic bacteria and moulds were never detected. Staff compliance to best practices varied depending on the type of behaviour investigated and the role of the operator. The major not compliant behaviours were: pre-operative skin antisepsis, crowding of the operating room and hand hygiene of the anaesthetist. The good environmental microbiological quality observed is indicative of the efficacy of the cleaning-sanitization procedures adopted. The major critical point was staff compliance to recommended practices. Awareness campaigns are therefore necessary, aimed at improving the organisation of work so as to facilitate compliance to operative protocols.

A QRM Discussion of Microbial Contamination of Non-sterile Drug Products, Using FDA and EMA Warning Letters Recorded between 2008 and 2016

Microbial quality control of non-sterile drug products has been a concern to regulatory agencies and the pharmaceutical industry since the 1960s. Despite being an old challenge to companies, microbial contamination still affects a high number of manufacturers of non-sterile products. Consequences go well beyond the obvious direct costs related to batch rejections or product recalls, as human lives and a company's reputation are significantly impacted if such events occur. To better manage risk and establish effective mitigation strategies, it is necessary to understand the microbial hazards involved in non-sterile drug products manufacturing, be able to evaluate their potential impact on final product quality, and apply mitigation actions. Herein we discuss the most likely root causes involved in microbial contaminations referenced in warning letters issued by US health authorities and non-compliance reports issued by European health authorities over a period of several years. The quality risk management tools proposed were applied to the data gathered from those databases, and a generic risk ranking was provided based on a panel of non-sterile drug product manufacturers that was assembled and given the opportunity to perform the risk assessments. That panel identified gaps and defined potential mitigation actions, based on their own experience of potential risks expected for their processes. Major findings clearly indicate that the manufacturers affected by the warning letters should focus their attention on process improvements and microbial control strategies, especially those related to microbial analysis and raw material quality control. Additionally, the WLs considered frequently referred to failures in quality-related issues, which indicates that the quality commitment should be reinforced at most companies to avoid microbiological contaminations.LAY ABSTRACT: Microbial contamination of drug products affects the quality of non-sterile drug products produced by numerous manufacturers, representing a major risk to patients. It is necessary to understand the microbial hazards involved in the manufacturing process and evaluate their impact on final product quality so that effective prevention strategies can be implemented. A risk-based classification of most likely root causes for microbial contamination found in the warning letters issued by the US Food and Drug Administration and the European Medicines Agency is proposed. To validate the likely root causes extracted from the warning letters, a subject matter expert panel made of several manufacturers was formed and consulted. A quality risk management approach to assess microbiological contamination of non-sterile drug products is proposed for the identification of microbial hazards involved in the manufacturing process. To enable ranking of microbial contamination risks, quality risk management metrics related to criticality and overall risk were applied. The results showed that manufacturers of non-sterile drug products should improve their microbial control strategy, with special attention to quality controls of raw materials, primary containers, and closures. Besides that, they should invest in a more robust quality system and culture. As a start, manufacturers may consider investigating their specific microbiological risks, adressing their sites' own microbial ecology, type of manufacturing processes, and dosage form characteristics, as these may lead to increased contamination risks. Authorities should allow and enforce innovative, more comprehensive, and more effective approaches to in-process contamination monitoring and controls.

Monitoring Salmonella, Campylobacter, Escherichia coli and Staphylococcus aureus in traditional free-range 'Label Rouge' broiler production: a 23-year survey programme

AIM

'Label Rouge' broiler free-range carcasses have been monitored since 1991, and broiler flocks since 2010, for contamination by the main foodborne zoonotic bacteria.

METHODS AND RESULTS

Initially, the monitoring plan mainly focused on the surveillance of Salmonella, and on indicators of the overall microbiological quality of free-range broiler carcasses such as Staphylococcus aureus and coliforms, but was extended in 2007 to include Campylobacter enumeration on carcasses and in 2010, to Salmonella in the environment of live birds. Salmonella contamination of free-range broiler carcasses rose to a peak of 16% in 1994 but less than 1% of carcasses are now regularly found to be positive. Indicators of the overall microbiological quality of carcasses are also improving. These results correlate with the low prevalence of Salmonella in free-range broiler breeding and production flocks, and with the continuous improvement of hazard analysis and critical control points in slaughterhouses, the implementation of a good manufacturing practice guide since 1997 and the application of EU regulations on Salmonella since 1998 in France. Regarding Campylobacter counts on carcasses, the situation has been improving continuously over the last few years, even if 2·5% of the carcasses are still contaminated by more than 1000 Campylobacter per g of skin.

CONCLUSIONS

Although the current control system focusing on Salmonella is based on firm epidemiologic data and offers effective means of control (e.g. slaughtering of positive breeder flocks), existing information on Campylobacter makes it more difficult to formulate an effective control plan for free-range broilers, due to their particular exposure to environmental contamination.

SIGNIFICANCE AND IMPACT OF THE STUDY

This long-term surveillance programme provided an extended view of the evolution of the contamination of free-range broilers and a direct measurement of the impact of mandatory and profession-driven interventions on the microbiological quality of carcasses.

From the donor's arm to blood product: a study on bacterial contamination of apheresis platelet concentrates

BACKGROUND

Transfusion-associated bacterial infections are a quite frequent collateral effect of administration of platelet concentrates (PC). We carried out a microbiological surveillance of bacterial contamination of apheresis platelet concentrates by studying microbial flora on donors' arms before and after skin disinfection, through blood cultures with the diversion volume and with the PC.

MATERIALS AND METHODS

Platelet aphereses were carried out using two Haemonetics MCS+ instruments. Cutaneous swabs were examined by the direct plate technique and blood cultures were performed using Bact/ALERT aerobic bottles. In the 5 years from January 2001 to December 2005 we tested 481 PC.

RESULTS

Cutaneous swabs showed significant bacterial growth in 89% of cases before skin disinfection and in 44% after. None of the blood cultures performed on diversion blood was positive, one (0.2%) PC was positive on the fifth day after collection and the presence of a Staphylococcus epidermidis strain was demonstrated.

CONCLUSIONS

Our results suggest that the skin disinfection protocol adopted in our structure is not fully satisfactory. The cultures performed on the PC showed a low prevalence of contamination, and the only positive sample was contaminated by a common skin contaminant (S. epidermidis). The culture became positive on the fifth day after collection, but on the second day the PC had been transfused to a patient, without any adverse reaction. In our experience a culture method using Bact/ALERT aerobic bottles was not able to prevent transfusion of the only contaminated PC identified in this study.

Massive microbiological groundwater contamination associated with a waterborne outbreak in Lake Erie, South Bass Island, Ohio

BACKGROUND

A groundwater-associated outbreak affected approximately 1,450 residents and visitors of South Bass Island, Ohio, between July and September 2004.

OBJECTIVES

To examine the microbiological quality of groundwater wells located on South Bass Island, we sampled 16 wells that provide potable water to public water systems 15-21 September 2004.

METHODS

We tested groundwater wells for fecal indicators, enteric viruses and bacteria, and protozoa (Cryptosporidium and Giardia). The hydrodynamics of Lake Erie were examined to explore the possible surface water-groundwater interactions.

RESULTS

All wells were positive for both total coliform and Escherichia coli. Seven wells tested positive for enterococci and Arcobacter (an emerging bacterial pathogen), and F(+)-specific coliphage was present in four wells. Three wells were positive for all three bacterial indicators, coliphages, and Arcobacter; adenovirus DNA was recovered from two of these wells. We found a cluster of the most contaminated wells at the southeast side of the island.

CONCLUSIONS

Massive groundwater contamination on the island was likely caused by transport of microbiological contaminants from wastewater treatment facilities and septic tanks to the lake and the subsurface, after extreme precipitation events in May-July 2004. This likely raised the water table, saturated the subsurface, and along with very strong Lake Erie currents on 24 July, forced a surge in water levels and rapid surface water-groundwater interchange throughout the island. Landsat images showed massive influx of organic material and turbidity surrounding the island before the peak of the outbreak. These combinations of factors and information can be used to examine vulnerabilities in other coastal systems. Both wastewater and drinking water issues are now being addressed by the Ohio Environmental Protection Agency and the Ohio Department of Health.