Comparison of wastewater treatment plants based on the emissions of microbiological contaminants.

This article presents the current and important results of bioaerosol studies which allow for the comparison of microbial contamination of air in 11 wastewater treatment plants (WWTPs), which differed in terms of capacity from 350 to 200,000 m3/day. The abundance of mesophilic bacteria, M+ and M- Staphylococcus, Pseudomonas fluorescens, Actinobacteria, coliform and psychrophilic bacteria, and microscopic fungi was determined. Additionally, the air temperature, relative humidity, wind velocity, and direction were also analyzed at each research station. The obtained very numerous results of bioaerosol and climate parameter studies were subjected to statistical analysis. The results regarding the minimum, maximum, and median abundance of the studied bacteria and microscopic fungi at 11 WWTPs and in background studies at control stations were presented in tables. Additionally, basic descriptive statistics for all studied microorganisms at specific seasons were presented. It was established that at the areas of WWTPs, the microscopic fungi were present that the highest concentrations (ranging from 0 to 1,148,530 CFU m-3), followed by psychrophilic bacteria (ranging from 40 to 225,000 CFU m-3) and mesophilic bacteria (ranging from 0 to 195,000 CFU m-3). The novel elaboration of bioaerosol study results based on cluster analysis and determination of a dendrogram allowed to compare the studied WWTPs. The similarity was decided based on the type of studied microorganisms and their dominance and abundance, while no similarities were observed in terms of capacity. In order to investigate the relation between the abundance of bacterial groups as well as microscopic fungi and microclimatic parameters (air temperature and humidity), a calculation of Spearman's range correlation coefficients was conducted.

Is water in dental units microbiologically safe?

BACKGROUND: Water supplied to the dental units must be of sufficient quality. The article presents the results of the microbiological analysis of cold municipal water which flows into a patient's disposable mouthwash cup, and demineralized water which flows through a waterline into the tool panel of a dental unit from the tank placed in the water group. MATERIAL AND METHODS: In order to assess the degree of purity (impurities) of water used in dental units, 2 series of microbiological tests were carried out in 6 dental surgeries from April to June, 2013. The water samples for microbiological testing were collected into sterile microbiological bottles in accordance with the current methodology. The water for the tests was collected from a sterile cup-filling tap (municipal water) and from an air/water syringe (demineralized water). The bacteria were cultured according to the Polish Standards - PN-EN ISO 6222, PN-EN ISO 9308-1, and PN-EN ISO 16266. RESULTS: In the tested samples of water numerous psychrophilic bacteria (max 29 100 CFU/ml) and mesophilic bacteria (max 24 700 CFU/ml), including single coliforms, were found. CONCLUSIONS: The results show that water delivered to a dental unit should be periodically tested bacteriologically and in terms of physical and chemical properties. Water systems of dental units should also be periodically disinfected to eliminate bacteria and biofilm.

The Hospital Environment as a Potential Source for Clostridioides difficile Transmission Based on Spore Detection Surveys Conducted at Paediatric Oncology and Gastroenterology Units.

Clostridioides difficile is an anaerobic, Gram-positive bacterium widely present in the hospital environment due to its ability to generate spores. The transfer of spores to patients through the hands of medical personnel is one of the most frequent paths of C. difficile transmission. In paediatric patients burdened with a serious primary illness requiring long-term hospitalisation and antibiotic therapy, C. difficile may be a significant risk factor for antibiotic-associated diarrhoea. The goal of the study was to assess the state of hospital environments as a potential source of C. difficile spores and to establish the share of hyperepidemic strains at the two paediatric units. The survey for C. difficile was conducted with a C. diff Banana BrothTM medium, used to detect spores and to recover vegetative forms of the bacteria. Environmental samples (n = 86) and swabs from the clothing of medical personnel (n = 14) were collected at two units of a paediatric hospital, where the cases of antibiotic-associated diarrhoea with a C. difficile aetiology constitute a significant clinical problem. In 17 samples, a change in the broth's colour was observed, indicating the presence of spores. Out of seven samples, C. difficile strains were cultured. The pathogenic isolates of C. difficile were obtained from swabs collected from elements of beds, a toilet, a door handle and a doctor's uniform. In our study, we indicated points of increased risk of pathogen transmission, which could constitute a source of infection. The clothing of medical personnel may be a dangerous carrier of pathogenic spores. Periodical surveys of hospital environments with the use of specialist microbiological mediums successfully indicate the direction of corrective actions to be undertaken by the medical facility in order to increase patient safety.

Spent Coffee as a Composite Filler for Wastewater Treatment.

Currently composites play an important role in all aspects of engineering and technology, with constantly growing applications. Recently, more attention was focused on natural fillers due to their suitability as reinforcement materials in thermo-plastic matrices which improve the mechanical properties of these polymers. Biofillers are used due to their low cost, high strength rigidity, non-toxicity, biodegradability, and availability. Currently, spent coffee grounds (SCG) are attracting more attention as a natural filler since high amounts of SCG are generated every day (food waste of coffee processing). This study allowed us to determine the long-term effect of activated sludge microorganisms with known technical and technological parameters on the mechanical properties of composites with spent coffee grounds filler. The fittings consisted of high-density poly-ethylene (PE-HD), which was used as the matrix, and a filler based on spent coffee grounds (SCG), which was used as a modifier. It was established that the composition of the composite and its residence time in the bioreactor directly influenced the contact angle value. The shift of the contact angle value is associated with the formation of the biofilm on the tested materials. An increase in the contact angle was observed in the case of all samples tested in the bioreactor, with the lowest values equal to approx. 76.4° for sample A (PE-HD) and higher values of approx. 90° for the remaining composite samples with a coffee grounds filler. The research confirmed that the increased ratio of coffee grounds in the composite results in the increased diversity and abundance of microorganisms. The highest number and the greatest diversity of microorganisms were observed in the case of the composite with 40% coffee grounds after more than a year of exposure in the bioreactor, while the composite with 30% SCG was second. Ciliates (Ciliata), especially the sessile forms belonging to the Epistylis genus, were the most common and the most numerous group of microorganisms in the activated sludge and in the biofilm observed on the samples after immersion in the bioreactor. The conducted research confirms that the use of polymer composite mouldings with a filler in the form of spent coffee grounds as a carrier allows the efficient increase in the population of microorganisms in the bioreactor.

Physicochemical and microbiological quality of rainwater harvested in underground retention tanks.

A study was made of the physicochemical properties (among others: pH, temperature, conductivity, hardness, chlorides, dissolved oxygen, ammonia, nitrites, nitrates, manganese, iron) and microbiological quality (coliform, psychrophilic and mesophilic microorganisms) of rainwater harvested from the roofs of three large buildings and from a parking lot, stored in three large underground tanks (with storage volume from 60 m3 to ca. 200 m3), including the variability of the quality. The underground tanks were located in the city of Poznan, and were characterized by different parameters, rainwater sources, rainwater treatment processes, and types of rainwater use. Samples of rainwater harvested in these tanks were collected from March 2019 to February 2020. Physicochemical and microbiological laboratory analyses were performed to determine selected parameters which have an impact on potential treatment and disinfection methods. The results obtained underwent statistical analysis. The laboratory tests showed that the physicochemical quality of rainwater collected in the three underground tanks met the Polish and EU requirements for drinking water standards. The main problem concerns microbiological quality: the number of coliform bacteria reached a value of 19,300 CFU/100 mL, the number of psychrophilic bacteria was over 264,000 CFU/1 mL, and the number of mesophilic bacteria was over 100,000 CFU/1 mL. Also the variability of microbiological quality was very high for all tanks. Analysis of the calcium carbonate equilibrium showed that the harvested water had corrosive properties. The treatment of the investigated rainwater for potable purposes should focus mainly on biological and chemical stability.

Detection and Analysis of Clostridioides difficile Spores in a Hospital Environment.

Clostridioides difficile, due to its long survival time in a hospital environment, is considered to be one of the most frequent factors in healthcare-associated infections. Patient care requires not only rapid and accurate diagnosis, but also knowledge of individual risk factors for infections, e.g., with C. difficile, in various clinical conditions. The goal of this study was to analyse the degree of contamination of a hospital environment with C. difficile spores. Culturing was performed using C diff Banana BrothTM medium, which enables germination of the spores of these bacteria. Samples were collected from inanimate objects within a hospital environment in a specialist hospital in Poland. The results of the study demonstrated the presence of 18 positive samples of Clostridioides spp. (15.4%). Of these, C. difficile spores were detected in six samples, Clostridioides perfringens in eight samples, Clostridioides sporogenes in two samples and Clostridioides innocuum and Clostridioides baratii in one sample each. Among the six samples of C. difficile, a total of four strains which produce the B toxin were cultured. The binary toxin related to ribotype 027 was not detected in our study. Nosocomial infection risk management is a significant problem, mainly concerning the issues of hygiene maintenance, cleaning policy and quality control, and awareness of infection risk.

Hand hygiene as the basic method of reducing Clostridium difficile infections (CDI) in a hospital environment.

INTRODUCTION: Clostridium difficile spores, due to their ability to adapt to adverse conditions in a hospital environment, cause enormous difficulties associated with the effective decontamination of surfaces and equipment. Elimination of this pathogen is possible through effective implementation of the hand hygiene procedure by all hospital employees. Scientific research indicates that a properly adopted hand washing procedure reduces the risk of Clostridium difficile infection (CDI) by half. OBJECTIVE: The aim of the study was to indicate the sources of nosocomial infections, mainly Clostridium difficile infection, and methods to limit them, with particular attention paid to the proper hand hygiene of the medical staff, which plays a fundamental role in the transmission of infections between hospitalized patients. BRIEF DESCRIPTION OF THE STATE OF KNOWLEDGE: Epidemiological studies indicate that about a half of Healthcare Associated Infection (HAI) is caused by microbes that contaminate the hands of medical personnel. One of the main pathogens is Clostridium difficile, which in 2018 in Poland accounted for 41.52% of all detected outbreaks originating from the hospital environment. According to data from WHO,16 million people worldwide die from Healthcare Associated Infection every year, of which approximately 17% constitutes mortality among people infected with Clostridium difficile. CONCLUSIONS: Non-compliance with hand hygiene among members of medical staff contributes to nosocomial infections which are a major cause of disease complications and deaths. Proper hand hygiene is a key measure for reducing this phenomenon. In every medical institution, especially in hospitals, and staff should be reminded about it and trained to perform the correct hand hygiene technique.

Nosocomial infections as one of the most important problems of healthcare system.

Healthcare-associated infections (HAI) are commonly defined as adverse events resulting from the provision of healthcare. The reduction of risk arising from the spread of pathogenic microorganisms in the hospital environment is a considerable challenge in the context of the proper functioning of the medical services sector. The financial costs of hospitals resulting from HAI are a serious problem for the Polish healthcare system. The spread of strains with a high level of drug resistance in individual hospitals is associated with the local epidemiological situation. In 2015-2017, there was a high increase in the number of infections caused by New Delhi strains. The highest increase due to this strain occurred in Mazowieckie and Podlasie provinces. The dynamics of infection caused by New Delhi strains throughout Poland in 2015-2016 indicated an increase of 278.7%. In 2017, the phenomenon of antibiotic abuse in all regions of Poland was 24% higher than the EU average. One of the reasons is the insufficient number of diagnostic tests ordered by both general practitioners and doctors representing hospital care. In 2016-2017, the average number of microbiological tests in diagnosing hospital infections performed annually within the entire territory of Poland was 50% lower than in European Union countries and the number recommended by WHO. Increased, and at the same time inappropriate antibiotic therapy led to a build-upof drug resistance among bacterial species of significant clinical importance. The current epidemiological situation imposes the necessity for constant HAI control and broadly understood rationalization of the guidelines of hospital antibiotic policy.

Application of a Novel PM Model to Assess the Risk of Clostridioides difficile Infections in Medical Facilities as a Tool for Improving the Quality of Health Services and the Safety of Patients.

Infections with multi-drug resistant microorganisms associated with the provision of health services have become an acute problem worldwide. These infections cause increased morbidity as well as mortality and are a financial burden for the healthcare system. Effective risk management can reduce the spread of infections and thus minimize their number in hospitalized patients. We have developed a new approach to the analysis of hazards and of exposure to the risk of adverse events by linking the patient's health record system to the entire infrastructure of the hospital unit. In this study, using the developed model, we focused on infections caused by the Clostridioides difficile bacterium, as they constitute a significant number of nosocomial infections in Poland and worldwide. The study was conducted in a medical facility located in the central part of Poland which provides tertiary care. In the proposed PM model, a risk analysis of hospital acquired infections at the Intensive Care and Anesthesiology Unit combined with the hospital's technical facilities and organizational factors was conducted. The obtained results indicate the most critical events which may have an impact on potential hazards or risks which may result from the patient's stay at the specific ward. Our method can be combined with an anti-problem approach, which minimizes the critical level of infection in order to determine the optimal functioning of the entire hospital unit. Research has shown that in most situations the spread dynamics of nosocomial infections can be controlled and their elimination may be attempted. In order to meet these conditions, the persons responsible for the daily operation of the medical facility and its individual wards have to indicate potential events and factors which present a risk to the hospitalized patients. On the basis of a created spreadsheet directions for improvement may be finally established for all potential events, their frequency may be minimized, and information may be obtained on actions which should be undertaken in a crisis situation caused by the occurrence of a given phenomenon. We believe that the proposed method is effective in terms of risk reduction, which is important for preventing the transmission of multi-drug resistant microorganisms in the hospital environment.

Biofilm on the polymer composites - qualitative and quantitative microbiological analysis.

BACKGROUND: Modern technology, which has been getting more and more recognition in the world for the last several years, is the moving bed biofilm reactor (MBBR) technology. Currently, movable biofilters made of basic polymeric materials, polyethylene and polypropylene. METHODS: An innovative solution in the field, mainly because of the large active surface area for biological membrane can be wood polymer composites (WPC). In the research polypropylene (PP) and polyvinyl chloride (PVC) was used as the matrix. Two types of commercial wood flour also, selected from conifers, were selected for the study: Lignocel C 120 with particle sizes in the range of 70 µm-150 µm and L9 with dimensions of 0.8-1.1 mm and wood chips, which are used on an industrial scale for the production of chipboards, were used as a filler. A quantitative and qualitative analysis of newly formed biofilms was performed. RESULTS: The study showed a direct effect of the filler and its particle size on the susceptibility to the formation of the biofilm of on the composites surface. CONCLUSIONS: Polypropylene PPH 648 T and 40% wt. of L9 type wood flour was the most susceptible to biofilm formation. Pure polypropylene PPH 648 T was the least susceptible material.

Level of Knowledge of Medical Staff on the Basis of the Survey in Terms of Risk Management, Associated with Clostridioides difficile Infections.

Infections caused by the toxigenic strains of Clostridioides difficile in the hospital environment pose a serious public health problem. The progressive increase in hospital infections in Poland indicates that risk management is a tool that is not used in an effective way and significantly differs from the goals set by the Leading Authorities, the Ministry of Health and its subordinate units. Systematic education of medical personnel constitutes the basic element of rational risk management aimed at reducing the number of infections as it allows for the transfer of knowledge, development of appropriate organizational procedures, and improves internal communication. This paper presents the results of a survey conducted in hospital facilities throughout Poland. The study dealt with what medical personnel know about channels of transmission and prevention of Clostridioides difficile infections in the hospital setting, professional training and risk management in terms of reducing the number of infections. The survey reveals that Clostridioides difficile continues to be a serious problem in the inpatient care system. Procedures and management strategies implemented by hospitals in order to limit the spread of the pathogen are predominantly focused on short-term action, which does not lead to a real improvement in terms of hospitalized patients' safety. The infection risk management system was assessed at a fairly low level. The obtained research results confirmed the research hypotheses that had been formulated.

Problems of Clostridium difficile infection (CDI) in Polish healthcare units.

The issue of patient safety during the provision of health services poses a key challenge in health policy. The number of hospital-acquired infections (also known as HAI - Healthcare Associated Infection) determines the level of quality of health services provided in a given health facility. Effective management reinforced by the awareness of a team of medical professionals allows not only reduction in the hospital's finances, but also the frequency of adverse events, which undoubtedly include hospital-acquired infections. Good cooperation between departments and a Hospital Infection Control Committee is one of the key aspects that translates to the rapid identification of new epidemic outbreaks. Infections caused by strains of Clostridium difficile (CDI, Clostridium difficile infection) are one of the main factors responsible for the prolonged hospitalization of patients. In the United States, Clostridium difficile causes almost half a million infections annually, and its treatment costs are estimated at nearly $ 4.8 billion per year. In Poland, the number of CDI cases in 2018 was 11.592 (for comparison, in 2013 the number of infections caused by this bacterium was 4.728). Hospital environment, inappropriate antibiotic therapy and development of multi-drug resistant strains increase the risk of infections. In order to improve the safety of hospitalized patients, infection risk management should be a systemic, formalized activity integrated with the overall process of managing a health facility. It is necessary that central units have interest in creating effective tools to enable successful epidemiological supervision and the implementation of strategic assumptions of health policy in this area.

Impact of physical and microbiological parameters on proper indoor air quality in nursery.

Although the evaluation of air quality in the residential and office rooms has been significantly developed in recent decades, the issues associated with securing the air quality requirements in nurseries are still not well recognised. This study presents the results of tests regarding the physical and microbiological properties of air in selected rooms of a nursery, including the alternatively variable way of rooms ventilation. The experiment was conducted in four different rooms from the 20th of November 2017 to the 16th of April 2018. The constant measurements of basic parameters of physical air quality in rooms and outside as well as the measurements of microbiological and particulate matter contaminations were conducted in the chosen days of the analysis. The results have confirmed the unsatisfactory air quality in the rooms dedicated to small children. Modernisation of the ventilation system, from a natural one to the supply-exhaust ventilation, has lead to an improvement of physical property of the air, but it did not significantly improve its microbiological quality. Our research indicates that the controlled air flow, method of cleaning the premise and health condition of the children may have a great influence on the physical and microbiological quality of the air.