Evaluation of a microscale quantitative suspension test to determine the bactericidal and yeasticidal activity of glutaral - one step to improve sustainability in disinfectant testing

Aims

To evaluate a newly developed microscale quantitative suspension test compared to the existing standard suspension test using determination of the bactericidal and yeasticidal activity of glutaral as one step to improve the sustainability of disinfectant testing.

Methods

The testing principles of the quantitative suspension test according to VAH method 9 (comparable to EN 13727) was used as a standard suspension test using 8.0 mL product test solution, 1.0 mL organic load and 1.0 mL test suspension. In addition, a micro-scale suspension test was performed in 96-well plates with 160 µL product test solution, 20 µL organic load and 20 µL test suspension. S. aureus ATCC 6538, P. aeruginosa ATCC 15442 and C. albicans ATCC 10231 were test organisms. Glutaral was tested at concentrations of 0.05%, 0.1%, 0.2% and 0.3% with exposure times of 1, 5 and 15 min. Polysorbate 80 (30 g/L), lecithin (9 g/L), L-histidine (1 g/L) and glycine (10 g/L) were used as validated neutralizers. After serial dilution of the disinfectant-neutralizer-mixture, plates were incubated for 48 h at 36°C (bacteria) or 72 hours at 30°C (C. albicans) and colony forming units (cfu) counted. The lg reduction was calculated as the difference between the results of the water control and the disinfectant at the end of the exposure time. All experiments were done in triplicate under clean conditions. Means of lg reduction were compared with the unpaired t-test, p<0.05 was considered to be significant.

Results

Sufficient bactericidal activity according the VAH test requirements of at least 5 lg was found with both methods in 16 data sets of 24 data sets in total, and insufficient bactericidal activity of less than 5 lg was found with both methods in 7 data sets. In one data set, the mean lg reduction was above 5 lg with the microscale method and <5 lg with the VAH method, with no significant difference between the data sets (p=0.3096; 0.2% glutaral, 1 min, P. aeruginosa). A sufficient yeasticidal activity of at least 4 lg was found with both methods in one data set, an insufficient yeasticidal activity of less than 4 lg was found with both methods in 8 data sets. With one exception, no significant differences were detected between the two methods below the efficacy threshold.

Conclusions

The microscale quantitative suspension test proved to provide results similar to those of VAH method 9 when the bactericidal and yeasticidal activity of glutaralwas evaluated, with 32 out of 33 evaluations yielding consistent results in terms of efficacy. Its suitability should be confirmed with additional bacterial species, additional biocidal active substances and in other laboratories.

Environmental Contamination and Persistence of Clostridioides difficile in Hospital Wastewater Systems

Clostridioides difficile produces an environmentally resistant dormant spore morphotype that infected patients shed to the hospital environment. C. difficile spores persist in clinical reservoirs that are not targeted by hospital routine cleaning protocols. Transmissions and infections from these reservoirs present a hazard to patient safety. This study aimed to assess the impact of patients acutely suffering from C. difficile-associated diarrhea (CDAD) on C. difficile environmental contamination to identify potential reservoirs. Twenty-three hospital rooms accommodating CDAD inpatients with corresponding soiled workrooms of 14 different wards were studied in a German maximum-care hospital. Additionally, four rooms that never accommodated CDAD patients were examined as negative controls. Stagnant water and biofilms from sinks, toilets, and washer disinfector (WD) traps as well as swabs from cleaned bedpans and high-touch surfaces (HTSs) were sampled. For detection, a culture method was used with selective medium. A latex agglutination assay and a Tox A/B enzyme-linked immunosorbent assay were performed with suspect colonies. Stagnant water and biofilms in hospital traps (29%), WDs (34%), and HTSs (37%) were found to be reservoirs for large amounts of C. difficile during the stay of CDAD inpatients that decreased but could persist 13 ± 6 days after their discharge (13%, 14%, and 9.5%, respectively). Control rooms showed none or only slight contamination restricted to WDs. A short-term cleaning strategy was implemented that reduced C. difficile in stagnant water almost entirely. IMPORTANCE Wastewater pipes are microbial ecosystems. The potential risk of infection emanating from the wastewater for individuals is often neglected, since it is perceived to remain in the pipes. However, sewage systems start with siphons and are thus naturally connected to the outside world. Wastewater pathogens do not only flow unidirectionally to wastewater treatment plants but also retrogradely, e.g., through splashing water from siphons to the hospital environment. This study focused on the pathogen C. difficile, which can cause severe and sometimes fatal diarrheas. This study shows how patients suffering from such diarrheas contaminate the hospital environment with C. difficile and that contamination persists in siphon habitats after patient discharge. This might pose a health risk for hospitalized patients afterward. Since this pathogen's spore morphotype is very environmentally resistant and difficult to disinfect, we show a cleaning measure that can almost entirely eliminate C. difficile from siphons.

Good handling practice of parenterally administered medicines in neonatal intensive care units - position paper of an interdisciplinary working group

This position paper, developed by an interdisciplinary expert group of neonatologists, paediatric infectious disease physicians, clinical pharmacists and specialists for the prevention and control of nosocomial infections, describes the "Good handling practice of medicines parenterally administered to patients on NICUs". It takes equal account of patient safety and the specialties of neonatal intensive care regarding feasibility and proportionality. The overall concept is perceived as a "learning system", in which open communication within the health-care team relating to medication errors and critical incidents enables continuous development and improvement to ensure patient safety. In our opinion, pharmacists, who are responsible for the supply of ready-to-administer parenteral medicinal products for neonatal intensive care patients, as well as the hygiene staff responsible on site are integral parts of the interdisciplinary treatment team. Risks of the current clinical practice of parenteral treatment of NICU patients are discussed in detail and recommendations for safety-relevant procedures are given.

Antibiotic concentrations in raw hospital wastewater surpass minimal selective and minimum inhibitory concentrations of resistant Acinetobacter baylyi strains

Antibiotics are essential for modern medicine, they are employed frequently in hospitals and, therefore, present in hospital wastewater. Even in concentrations, that are lower than the minimum inhibitory concentrations (MICs) of susceptible bacteria, antibiotics may exert an influence and select resistant bacteria, if they exceed the MSCs (minimal selective concentrations) of resistant strains. Here, we compare the MSCs of fluorescently labelled Acinetobacter baylyi strains harboring spontaneous resistance mutations or a resistance plasmid with antibiotic concentrations determined in hospital wastewater. Low MSCs in the μg/L range were measured for the quinolone ciprofloxacin (17 μg/L) and for the carbapenem meropenem (30 μg/L). A 24 h continuous analysis of hospital wastewater showed daily fluctuations of the concentrations of these antibiotics with distinctive peaks at 7-8 p.m. and 5-6 a.m. The meropenem concentrations were always above the MSC and MIC values of A. baylyi. In addition, the ciprofloxacin concentrations were in the range of the lowest MSC for about half the time. These results explain the abundance of strains with meropenem and ciprofloxacin resistance in hospital wastewater and drains.

Hygiene and disinfection measures for monkeypox virus infections

In Germany, recommendations on infection prevention and control of current virus outbreaks are given as communications by the Association for Applied Hygiene e.V. (VAH) together with the joint Disinfectant Commission of the German Association for the Control of Virus Diseases e.V. (DVV) and the Society of Virology* (GfV). The DVV was founded in 1954 in response to the ongoing threat to the population from polio and was given its current name in 1977. The DVV is supported by the Federal Ministry of Health, the Ministries of Health of the Federal States, scientific societies, as well as social foundations and organisations. Private individuals cannot be members of the DVV. The Society of Virology e.V. (GfV) is a scientific society for all virological fields in Germany, Austria and Switzerland, and is thus the largest virological society in Europe. With numerous commissions, guidelines and statements, it is the authoritative contact for research, healthcare and politics. The joint commission "Virus Disinfection" of these scientific societies focuses on the efficacy of chemical disinfection procedures against viruses. The VAH bundles the expertise of scientific societies and experts on infection prevention and is particularly committed to the quality assurance of hygiene measures. With the VAH disinfectant list, the association provides the standard reference for the selection of high-quality disinfection procedures. This disinfectant list has a tradition of more than 60 years in Germany. The original German version of this document was published in August 2022 and has now been made available to the international professional public in English. The document contains recommendations on hygiene and disinfection measures for monkeypox virus infections. Disinfectants against monkeypox must have at least proven efficacy against enveloped viruses (active against enveloped viruses); products with the efficacy ranges "limited virucidal activity" and "virucidal" can also be used. The disinfectant list of the VAH or the disinfectant list of the Robert Koch Institute are available for the selection of products. Especially in the case of contamination with crust or scab material, it should be noted that protein contamination can have a protective or stabilising effect on monkeypox. Therefore, cleaning - before disinfection - should always be carried out in this situation. Preventive measures such as vaccination and hygiene in the vicinity of people with monkeypox must be taken to prevent transmission to small children, pregnant women or people with a pronounced immune deficiency.

Explosive COVID-19 outbreak in a German nursing home and the possible role of the air ventilation system

Background

Most COVID-19 outbreaks in nursing homes are explained by transmission of SARS-CoV-2 from nurses or visitors.

Methods and results

We describe an outbreak with 64 of the 67 residents identified as COVID-19 cases within two weeks (34 in nursing block 1, 30 in nursing block 2), at least 32 of them had relevant symptoms of COVID-19. Thirteen of the residents’ deaths were associated with COVID-19. In addition, 27 of approximately 60 staff members were identified as COVID-19 cases, 23 of them had relevant symptoms. In none of the samples from residents or staff was a mutation of SARS-CoV-2 detected. Quarantine of the residents was already in force at the beginning of the outbreak. A common source among the staff was considered to be unlikely because the two nursing home blocks had no staff rotation and the staff had to wear FFP2 masks during contact with residents. Three months after the outbreak the RNA of SARS-CoV-2 was detected on 14 of 39 sampled indoor surfaces of the air ventilation system with Ct values between 34.9 and 41.9, but only at the air supply in the corridor (11 of 24 samples) and the air overflow in the door between the corridor and the residents’ rooms (three of 11 samples) but not at the air exhaust in the residents’ bathrooms.

Conclusions

The air ventilation system and an inversion weather situation three days before the first confirmed case may have enhanced viral spread inside the nursing home assuming that a common source with a high viral load had existed at the time of outbreak.

Recommendation of the German Society of Hospital Hygiene (DGKH): Prevention of COVID-19 by virucidal gargling and virucidal nasal spray - updated version April 2022

The German Society of Hospital Hygiene develops guidelines, recommendations and standard operation procedures on a voluntary basis, published on the DGKH-website (https://www.krankenhaushygiene.de/). The original German version of this recommendation was published in April 2022 and has now been made available to the international professional public in English. Evaluating the current data on the efficacy of virucidal gargle/mouthwash solutions and nasal sprays against SARS-CoV-2 in vitro and in clinical trials, conducted with preventive or therapeutic objectives, recommendations are given for the prevention of COVID-19. The following areas are considered: Protection of the community when regional clusters or high incidences of infection become knownProtection of the community at low risk of infectionPre-exposure prophylaxis for the protection of healthcare workersPost-exposure prophylaxis.

Ethanol is indispensable for virucidal hand antisepsis: memorandum from the alcohol-based hand rub (ABHR) Task Force, WHO Collaborating Centre on Patient Safety, and the Commission for Hospital Hygiene and Infection Prevention (KRINKO), Robert Koch Institute, Berlin, Germany

BACKGROUND

The approval of ethanol by the Biocidal Products Regulation has been under evaluation since 2007. This follows concern over alcohol uptake from ethanol-based hand rubs (EBHR). If ethanol is classified as carcinogenic, mutagenic, or reprotoxic by the European Chemicals Agency (ECHA), then this would affect infection prevention and control practices.

AIM

A review was performed to prove that ethanol is toxicological uncritical and indispensable for hand antisepsis because of its unique activity against non-enveloped viruses and thus the resulting lack of alternatives. Therefore, the following main points are analyzed: The effectiveness of ethanol in hand hygiene, the evidence of ethanol at blood/tissue levels through hand hygiene in healthcare, and the evidence of toxicity of different blood/tissue ethanol levels and the non-comparability with alcoholic consumption and industrial exposure.

RESULTS

EBHR are essential for preventing infections caused by non-enveloped viruses, especially in healthcare, nursing homes, food industry and other areas. Propanols are effective against enveloped viruses as opposed to non-enveloped viruses but there are no other alternatives for virucidal hand antisepsis. Long-term ingestion of ethanol in the form of alcoholic beverages can cause tumours. However, lifetime exposure to ethanol from occupational exposure < 500 ppm does not significantly contribute to the cancer risk. Mutagenic effects were observed only at doses within the toxic range in animal studies. While reprotoxicity is linked with abuse of alcoholic beverages, there is no epidemiological evidence for this from EBHR use in healthcare facilities or from products containing ethanol in non-healthcare settings.

CONCLUSION

The body of evidence shows EBHRs have strong efficacy in killing non-enveloped viruses, whereas 1-propanol and 2-propanol do not kill non-enveloped viruses, that pose significant risk of infection. Ethanol absorbed through the skin during hand hygiene is similar to consumption of beverages with hidden ethanol content (< 0.5% v/v), such as apple juice or kefir. There is no risk of carcinogenicity, mutagenicity or reprotoxicity from repeated use of EBHR. Hence, the WHO Task Force strongly recommend retaining ethanol as an essential constituent in hand rubs for healthcare.

SARS-CoV-2 in Environmental Samples of Quarantined Households

The role of environmental transmission of SARS-CoV-2 remains unclear. Thus, the aim of this study was to investigate whether viral contamination of air, wastewater, and surfaces in quarantined households result in a higher risk for exposed persons. For this study, a source population of 21 households under quarantine conditions with at least one person who tested positive for SARS-CoV-2 RNA were randomly selected from a community in North Rhine-Westphalia in March 2020. All individuals living in these households participated in this study and provided throat swabs for analysis. Air and wastewater samples and surface swabs were obtained from each household and analysed using qRT-PCR. Positive swabs were further cultured to analyse for viral infectivity. Out of all the 43 tested adults, 26 (60.47%) tested positive using qRT-PCR. All 15 air samples were qRT-PCR-negative. In total, 10 out of 66 wastewater samples were positive for SARS-CoV-2 (15.15%) and 4 out of 119 surface samples (3.36%). No statistically significant correlation between qRT-PCR-positive environmental samples and the extent of the spread of infection between household members was observed. No infectious virus could be propagated under cell culture conditions. Taken together, our study demonstrates a low likelihood of transmission via surfaces. However, to definitively assess the importance of hygienic behavioural measures in the reduction of SARS-CoV-2 transmission, larger studies should be designed to determine the proportionate contribution of smear vs. droplet transmission.

SARS-CoV-2 in Environmental Samples of Quarantined Households

The role of environmental transmission of SARS-CoV-2 remains unclear. Thus, the aim of this study was to investigate whether viral contamination of air, wastewater, and surfaces in quarantined households result in a higher risk for exposed persons. For this study, a source population of 21 households under quarantine conditions with at least one person who tested positive for SARS-CoV-2 RNA were randomly selected from a community in North Rhine-Westphalia in March 2020. All individuals living in these households participated in this study and provided throat swabs for analysis. Air and wastewater samples and surface swabs were obtained from each household and analysed using qRT-PCR. Positive swabs were further cultured to analyse for viral infectivity. Out of all the 43 tested adults, 26 (60.47%) tested positive using qRT-PCR. All 15 air samples were qRT-PCR-negative. In total, 10 out of 66 wastewater samples were positive for SARS-CoV-2 (15.15%) and 4 out of 119 surface samples (3.36%). No statistically significant correlation between qRT-PCR-positive environmental samples and the extent of the spread of infection between household members was observed. No infectious virus could be propagated under cell culture conditions. Taken together, our study demonstrates a low likelihood of transmission via surfaces. However, to definitively assess the importance of hygienic behavioural measures in the reduction of SARS-CoV-2 transmission, larger studies should be designed to determine the proportionate contribution of smear vs. droplet transmission.

Dynamics, outcomes and prerequisites of the first SARS-CoV-2 superspreading event in Germany in February 2020: a cross-sectional epidemiological study

OBJECTIVES

The first German SARS-CoV-2 outbreak was a superspreading event in Gangelt, North Rhine-Westphalia, during indoor carnival festivities called 'Kappensitzung' (15 February 2020). We determined SARS-CoV-2 RT-PCR positivity rate, SARS-CoV-2-specific antibodies, and analysed the conditions and dynamics of superspreading, including ventilation, setting dimensions, distance from infected persons and behavioural patterns.

DESIGN

In a cross-sectional epidemiological study (51 days postevent), participants were asked to give blood, pharyngeal swabs and complete self-administered questionnaires.

SETTING

The SARS-CoV-2 superspreading event took place during festivities in the small community of Gangelt in February 2020. This 5-hour event included 450 people (6-79 years of age) in a building of 27 m × 13.20 m × 4.20 m.

PARTICIPANTS

Out of 450 event participants, 411 volunteered to participate in this study.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome: infection status (determined by IgG ELISA).

SECONDARY OUTCOME

symptoms (determined by questionnaire).

RESULTS

Overall, 46% (n=186/404) of participants had been infected, and their spatial distribution was associated with proximity to the ventilation system (OR 1.39, 95% CI 0.86 to 2.25). Risk of infection was highly associated with age: children (OR 0.33, 95% CI 0.267 to 0.414) and young adults (age 18-25 years) had a lower risk of infection than older participants (average risk increase of 28% per 10 years). Behavioural differences were also risk associated including time spent outside (OR 0.55, (95% CI 0.33 to 0.91) or smoking (OR 0.32, 95% CI 0.124 to 0.81).

CONCLUSIONS

Our findings underline the importance of proper indoor ventilation for future events. Lower susceptibility of children/young adults indicates their limited involvement in superspreading.

Dissemination of carbapenem resistant bacteria from hospital wastewater into the environment

Infections with antibiotic resistant pathogens threaten lives and cause substantial costs. For effective interventions, knowledge of the transmission paths of resistant bacteria to humans is essential. In this study, carbapenem resistant bacteria were isolated from the wastewater of a maximum care hospital during a period of two years, starting in the patient rooms and following the sewer system to the effluent of the wastewater treatment plant (WWTP). The bacteria belonged to six different species and 44 different sequence types (STs). The most frequent STs, ST147 K. pneumoniae (bla_NDM/bla_OXA-48) and ST235 P. aeruginosa (bla_VIM) strains, were present at nearly all sampling sites from the hospital to the WWTP effluent. After core genome multi-locus sequence typing (cgMLST), all ST147 K. pneumoniae strains presented a single epidemiological cluster. In contrast, ST235 P. aeruginosa formed five cgMLST clusters and the largest cluster contained the strain from the WWTP effluent, indicating without doubt, a direct dissemination of both high-risk clones into the environment. Thus, there are - at least two - possible transmission pathways to humans, (i) within the hospital by contact with the drains of the sanitary installations and (ii) by recreational or irrigation use of surface waters that have received WWTP effluent. In conclusion, remediation measures must be installed at both ends of the wastewater system, targeting the drains of the hospital as well as at the effluent of the WWTP.

LAMP-Seq enables sensitive, multiplexed COVID-19 diagnostics using molecular barcoding

Frequent testing of large population groups combined with contact tracing and isolation measures will be crucial for containing Coronavirus Disease 2019 outbreaks. Here we present LAMP-Seq, a modified, highly scalable reverse transcription loop-mediated isothermal amplification (RT-LAMP) method. Unpurified biosamples are barcoded and amplified in a single heat step, and pooled products are analyzed en masse by sequencing. Using commercial reagents, LAMP-Seq has a limit of detection of ~2.2 molecules per µl at 95% confidence and near-perfect specificity for severe acute respiratory syndrome coronavirus 2 given its sequence readout. Clinical validation of an open-source protocol with 676 swab samples, 98 of which were deemed positive by standard RT-qPCR, demonstrated 100% sensitivity in individuals with cycle threshold values of up to 33 and a specificity of 99.7%, at a very low material cost. With a time-to-result of fewer than 24 h, low cost and little new infrastructure requirement, LAMP-Seq can be readily deployed for frequent testing as part of an integrated public health surveillance program.

A European approach to infection prevention and control goals

The current pandemic caused by COVID-19 has underlined the importance of a joint effort and approach to ensure patient and health care worker safety in medical care throughout Europe. In addition, the recent flood disasters in Germany and other countries called for immediate joint action, in this case with regard to the prevention of water-borne infections. Environmental disasters will increase with consequences for hospitals and nursing homes. Cooperative efforts are needed for preventing and controlling associated infection outbreaks, new pathogens will appear and a geographic shift of infectious diseases previously not detected in certain areas has already been observed. This approach to infection prevention and control must entail structural as well as regulatory aspects. The principle of equal protection against infections in all European countries must be implemented. Prevention and control of infections, including nosocomial infections, infections caused by antibiotic-resistant bacteria as well as pandemics, need to be based on equal standards in all of Europe. Protection against infections and other public health risks in all European countries is the best guarantor for building trust and identification of citizens in our common Europe. Experts in the fields of hygiene, microbiology, infectiology and epidemiology have to pool the expertise on the prevention and control of infections from different European countries and define key targets for achieving a high standard of hygiene measures throughout Europe. The participants of the Rudolf Schülke Foundation International Symposium call for immediate action and priority to be given to the realization of the proposed 16-point plan.

Future challenges in hospital hygiene and public health due to air-associated health hazards

Issue

In recent decades, hospital hygiene has focused on effective control strategies against contact or waterborne transmissions. Outside operating theatres or infection wards, airborne pathogens have played a minor role so far. For public health, the airborne route of transmission also played a subordinate role. Apart from bioterrorism, the focus here is more on chemical and physical hazards. In future, air-associated health hazards will increase. Besides airborne pathogens, examples include insects, heatwaves, particulate matter as well as pollen, mould and radon.

Description of the problem

No attention has been paid to systematic risk regulation of the transmission mode air. Hospital hygiene is ‘micro-level public health' with a particularly vulnerable population. The experience of hospital hygiene measures can help to develop appropriate public health interventions. Which air hygiene measures have we taken to counter SARS-CoV-2 and how can these be more efficient in the future?

Results

In response to SARS-CoV-2, face masks were introduced. This has reduced the risk of transmission both in hospitals and in public, but has not completely prevented indirect transmission through aerosols indoors. Ventilation rules further reduced the risk of transmission, but were not applicable everywhere. Since most buildings do not have central air filtration units, the use of decentralised air filters increased, with unknown relevance.

Lessons

Breathing air cannot be substituted. Therefore, air hygiene is a primary prevention and needs to become more structured to be effective against future air-associated health hazards. Future construction projects for hospitals and public buildings must be adapted to prevention of air-associated health hazards. Hazard and risk analyses, technical, organisational and personal control measures, their monitoring and an incident management should be combined into an ‘Air Safety Plan' as part of a hygiene plan for hospitals and the public.

Key messages

Breathing air is increasingly polluted by natural or anthropogenic chemical, biological and physical influences and thus becomes a carrier of health hazards, especially for vulnerable groups.

Since air cannot be replaced, primary preventive air hygiene based on “Air Safety Plans” will be important in the future as an efficient measure against air-associated hazards such as SARS-CoV-2.

Outbreak of Pseudomonas aeruginosa infections after CT-guided spinal injections

BACKGROUND

Meningitis and spinal infections with Gram-negative bacteria after local injections for treatment of chronic back pain are rare. This study investigated an outbreak of Pseudomonas aeruginosa infections following computed tomography (CT)-guided spinal injections (SI).

METHODS

A case was defined as a spinal infection or meningitis with P. aeruginosa after SI between 10^th January and 1^st March 2019 in the same outpatient clinic. Patients without microbiological evidence of P. aeruginosa but with a favourable response to antimicrobial therapy active against P. aeruginosa were defined as probable cases.

FINDINGS

Twenty-eight of 297 patients receiving CT-guided SI during the study period developed meningitis or spinal infections. Medical records were available for 19 patients. In 15 patients, there was microbiological evidence of P. aeruginosa, and four patients were defined as probable cases. Two of 19 patients developed meningitis, while the remaining 17 patients developed spinal infections. The median time from SI to hospital admission was 8 days (interquartile range 2-23 days). Patients mainly presented with back pain (N=18; 95%), and rarely developed fever (N=3; 16%). Most patients required surgery (N=16; 84%). Seven patients (37%) relapsed and one patient died. Although the source of infection was not identified microbiologically, documented failures in asepsis when performing SI probably contributed to these infections.

CONCLUSIONS

SI is generally considered safe, but non-adherence to asepsis can lead to deleterious effects. Spinal infections caused by P. aeruginosa are difficult to treat and have a high relapse rate.

Air filtration as a tool for the reduction of viral aerosols

For testing the effectiveness of air purification devices in regard to the reduction of virus-containing aerosols, a test method involving test viruses has been lacking until now. The use of bacteriophages (phiX174 phages) is a method to test the efficiency of air purification devices under experimental conditions. Using air purifiers with a HEPA filter H14, a 4.6-6.1 Log reduction of test viruses can be achieved if bacteriophages are directly aerosolised into the air purifier, which corresponds to a reduction of 99.9974-99.9999%. Due to the complexity and individuality of air flow, an experimental approach was used in which all outside influences were minimised. The experimental setup was practical and chosen to project a scenario of direct transmission by an emitting source to a recipient. The experiments were performed with and without the air purifier at a distance of 0.75 m and 1.5 m each. Using the air purifier at a setting of 1000 m³/h, the concentration of the phiX174 phages in the air could be reduced by 2.86 Log (mean value). Nevertheless, the experiments without the air purifier showed a similar reduction rate of 2.61 Log (mean value) after 35 min. The concentration of phiX174 phages in the air could be additionally reduced up to 1 log step (maximum value) by the use of the air purifier in comparison to the experiments without. Distance was shown to be an important factor for risk reduction.

[Lead in drinking water-an old problem, a new EU directive]

BACKGROUND

Lead pipes have been used in drinking water installations for a long time. Only since 1973 have their use in new buildings been strongly discouraged; nevertheless, they are still found in old buildings. Furthermore, lead-containing alloys are still used today in components such as fittings. This results in an avoidable pollution of drinking water. The health significance of this pollution is acknowledged by a reduction of the currently valid limit value from 10 µg/l to 5 µg/l by the new EU drinking water directive passed in 2020. This directive provides for a transition period of 15 years.

OBJECTIVES

The relevance of a stricter limit value for lead in drinking water will be evaluated based by the results of routine analyses, and the necessary public health measures to prevent exposure of vulnerable groups will be formulated.

MATERIAL AND METHODS

A retrospective analysis of routine samples from the city of Bonn, which an accredited drinking water laboratory had examined in the years 1997-2019, was performed.

RESULTS

Of the 16,060 samples analyzed, 75.36% were below the quantitative limit of quantification. The median of the quantifiable samples was above the future limit for lead in drinking water in each year considered. No effect of the last transition period of 10 years (2003-2013) could be detected.

DISCUSSION

Even though no systematic studies on lead pollution in German municipalities are available, the subject is still highly topical. Lead exposure from drinking water installations is a completely avoidable health risk, but it can only be regulated by consistent enforcement of the applicable rules by the health authorities. The health authorities must be adequately equipped in terms of personnel, material, and financial resources.

Clinically relevant antibiotic-resistant bacteria in aquatic environments - An optimized culture-based approach

The emergence of antibiotic-resistant clinically relevant facultative pathogenic bacteria in the environment has become one of the most important global health challenges. Antibiotic-resistant bacteria (ARB) have been found in surface waters and wastewater treatment plants. Drinking water guidelines and the EU bathing water directive 2006/7/EC include the surveillance of defined microbiological parameters on species level, while the monitoring of ARB is missing in all existing guidelines. However, standardized methods for the detection of ARB exist for clinical investigations of human materials only. They are based on cultivation on selective agar plates. These methods cannot be used directly for environmental samples, because of the high amount and diversity of bacterial background flora which interferes with the detection of human-relevant ARB. The aim of this study was to introduce a proposal for future normative standard operation procedures, with international relevance, for the culture-based detection of clinically-relevant antibiotic resistant bacteria in aquatic environmental samples like wastewater and surface water: gram-negative bacteria resistant against 3rd generation cephalosporins (ESBL) and against carbapenems (CARBA), gram-positive vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA). The final adaptation of standardized cultivation methods included increasing the standard incubation temperature from 36 °C to 42 °C, which effectively inhibits the environmental background flora on agar plates while the desired target species survive. This enables the detection of target species in suitable sample volumes. Putative target colonies which belong to the remaining background flora had to be excluded by morphological and physiological differentiation. Therefore, a time and cost optimized testing scheme with good performance was developed, which allows an effective exclusion of non-target isolates in samples. Depending on the target species and sample type, sensitivity of up to 100% is achieved, and specificity ranges from 91.1% to 99.7%, while the positive predictive value, negative predicted value and accuracy rate are always >90%.

Chemical disinfection in healthcare settings: critical aspects for the development of global strategies

Chemical disinfection is an indispensable means of preventing infection. This holds true for healthcare settings, but also for all other settings where transmission of pathogens poses a potential health risk to humans and/or animals. Research on how to ensure effectiveness of disinfectants and the process of disinfection, as well as on when, how and where to implement disinfection precautions is an ongoing challenge requiring an interdisciplinary team effort. The valuable resources of active substances used for disinfection must be used wisely and their interaction with the target organisms and the environment should be evaluated and monitored closely, if we are to reliable reap the benefits of disinfection in future generations. In view of the global threat of communicable diseases and emerging and re-emerging pathogens and multidrug-resistant pathogens, the relevance of chemical disinfection is continually increasing. Although this consensus paper pinpoints crucial aspects for strategies of chemical disinfection in terms of the properties of disinfectant agents and disinfection practices in a particularly vulnerable group and setting, i.e., patients in healthcare settings, it takes a comprehensive, holistic approach to do justice to the complexity of the topic of disinfection.

SARS-CoV-2 outbreak investigation in a German meat processing plant

We describe a multifactorial investigation of a SARS-CoV-2 outbreak in a large meat processing complex in Germany. Infection event timing, spatial, climate and ventilation conditions in the processing plant, sharing of living quarters and transport, and viral genome sequences were analyzed. Our results suggest that a single index case transmitted SARS-CoV-2 to co-workers over distances of more than 8 m, within a confined work area in which air is constantly recirculated and cooled. Viral genome sequencing shows that all cases share a set of mutations representing a novel sub-branch in the SARS-CoV-2 C20 clade. We identified the same set of mutations in samples collected in the time period between this initial infection cluster and a subsequent outbreak within the same factory, with the largest number of confirmed SARS-CoV-2 cases in a German meat processing facility reported so far. Our results indicate climate conditions, fresh air exchange rates, and airflow as factors that can promote efficient spread of SARS-CoV-2 via long distances and provide insights into possible requirements for pandemic mitigation strategies in industrial workplace settings.

SARS-CoV-2 outbreak investigation in a German meat processing plant

We describe a multifactorial investigation of a SARS-CoV-2 outbreak in a large meat processing complex in Germany. Infection event timing, spatial, climate and ventilation conditions in the processing plant, sharing of living quarters and transport, and viral genome sequences were analyzed. Our results suggest that a single index case transmitted SARS-CoV-2 to co-workers over distances of more than 8 m, within a confined work area in which air is constantly recirculated and cooled. Viral genome sequencing shows that all cases share a set of mutations representing a novel sub-branch in the SARS-CoV-2 C20 clade. We identified the same set of mutations in samples collected in the time period between this initial infection cluster and a subsequent outbreak within the same factory, with the largest number of confirmed SARS-CoV-2 cases in a German meat processing facility reported so far. Our results indicate climate conditions, fresh air exchange rates, and airflow as factors that can promote efficient spread of SARS-CoV-2 via long distances and provide insights into possible requirements for pandemic mitigation strategies in industrial workplace settings.

Bacteria isolated from hospital, municipal and slaughterhouse wastewaters show characteristic, different resistance profiles

Multidrug-resistant bacteria cause difficult-to-treat infections and pose a risk for modern medicine. Sources of multidrug-resistant bacteria include hospital, municipal and slaughterhouse wastewaters. In this study, bacteria with resistance to 3rd generation cephalosporins were isolated from all three wastewater biotopes, including a maximum care hospital, municipal wastewaters collected separately from a city and small rural towns and the wastewaters of two pig and two poultry slaughterhouses. The resistance profiles of all isolates against clinically relevant antibiotics (including β-lactams like carbapenems, the quinolone ciprofloxacin, colistin, and trimethoprim/sulfamethoxazole) were determined at the same laboratory. The bacteria were classified according to their risk to human health using clinical criteria, with an emphasis on producers of carbapenemases, since carbapenems are prescribed for hospitalized patients with infections with multi-drug resistant bacteria. The results showed that bacteria that pose the highest risk, i. e., bacteria resistant to all β-lactams including carbapenems and ciprofloxacin, were mainly disseminated by hospitals and were present only in low amounts in municipal wastewater. The isolates from hospital wastewater also showed the highest rates of resistance against antibiotics used for treatment of carbapenemase producers and some isolates were susceptible to only one antibiotic substance. In accordance with these results, qPCR of resistance genes showed that 90% of the daily load of carbapenemase genes entering the municipal wastewater treatment plant was supplied by the clinically influenced wastewater, which constituted approximately 6% of the wastewater at this sampling point. Likewise, the signature of the clinical wastewater was still visible in the resistance profiles of the bacteria isolated at the entry into the wastewater treatment plant. Carbapenemase producers were not detected in slaughterhouse wastewater, but strains harboring the colistin resistance gene mcr-1 could be isolated. Resistances against orally available antibiotics like ciprofloxacin and trimethoprim/sulfamethoxazole were widespread in strains from all three wastewaters.

Infection fatality rate of SARS-CoV2 in a super-spreading event in Germany

A SARS-CoV2 super-spreading event occurred during carnival in a small town in Germany. Due to the rapidly imposed lockdown and its relatively closed community, this town was seen as an ideal model to investigate the infection fatality rate (IFR). Here, a 7-day seroepidemiological observational study was performed to collect information and biomaterials from a random, household-based study population. The number of infections was determined by IgG analyses and PCR testing. We found that of the 919 individuals with evaluable infection status, 15.5% (95% CI:[12.3%; 19.0%]) were infected. This is a fivefold higher rate than the reported cases for this community (3.1%). 22.2% of all infected individuals were asymptomatic. The estimated IFR was 0.36% (95% CI:[0.29%; 0.45%]) for the community and 0.35% [0.28%; 0.45%] when age-standardized to the population of the community. Participation in carnival increased both infection rate (21.3% versus 9.5%, p < 0.001) and number of symptoms (estimated relative mean increase 1.6, p = 0.007). While the infection rate here is not representative for Germany, the IFR is useful to estimate the consequences of the pandemic in places with similar healthcare systems and population characteristics. Whether the super-spreading event not only increases the infection rate but also affects the IFR requires further investigation.

Measures to maintain regular operations and prevent outbreaks of SARS-CoV-2 in childcare facilities or schools under pandemic conditions and co-circulation of other respiratory pathogens

After the lockdown and the end of the summer holidays, day-cares and schools need to be reopened and (despite the continued circulation of the new coronavirus SARS-CoV-2) kept open. The need for opening up arises from the right of children to education, participation, support and care. This is possible if appropriate hygiene measures are implemented and community transmission remains stable. In addition, the safety of educators, teachers and carers must be a priority and needs to be addressed by appropriate measures. Finally, the needs of families must also be taken into account. The following document describes in detail how these objectives can be achieved.

Impact of surface disinfection with hydrogen peroxide on the prevalence of vancomycin-resistant enterococci (VRE) in hospital wards

Objective: Vancomycin-resistant enterococci (VRE) are of major concern in infection control. Although broad infection control actions to check VRE have been implemented, VRE remain part of daily infection prevention in clinical settings. Cleaning procedures in the inanimate ward environment might play a key role in controlling VRE. In order to optimize infection control management at University Hospital Frankfurt, Germany (UHF), this study evaluates the impact of H₂O₂-containing cleaning wipes compared to Glucoprotamin containing wipes on VRE prevalence in intensive care wards.

Methods: Retrospective analyses were conducted of the VRE prevalence on environmental materials obtained from three intensive care units (ICU) at UHF for 17 months prior to (T1) and during the 25 months after (T2) the implementation of H₂O₂-containing cleaning wipes from January 2016 to June 2019. The bactericidal power of the two disinfectants against VRE was compared using the 4-field test according to EN 16615 (2015).

Results: At T1 and T2, n=666 and n=710 environmental samples, respectively, were obtained. At T1, 24.2% (n=161/666; 95% confidence interval: 21.0–27.6) and at T2, 6.9% (n=49/710; 5.1–9.0) samples were positive for VRE. In vitro disinfectant testing did not reveal any superiority of H₂O₂ over glucoprotamin. No effect on the VRE prevalence in patients’ rectal screening materials was observed.

Conclusion: Though Glucoprotamin and H₂O₂ were in vitro equally effective against VRE, the prevalence of VRE in ICU environment at UHF decreased after implementation of H₂O₂-containig wipes. This might be due to multiple factors, of which we consider the impact of the Hawthorne effect to be the strongest. Success of infection control strategies might depend on the compliance of the persons critically involved. Transparent information on infection control strategies is suggested to increase compliance and should therefore be considered both in daily infection control and outbreak management.

Children and adolescents in the CoVid-19 pandemic: Schools and daycare centers are to be opened again without restrictions. The protection of teachers, educators, carers and parents and the general hygiene rules do not conflict with this

In the opinion of the medical societies of hygiene and pediatrics undersigning the present statement, the analyses published to date regarding transmission of SARS-CoV-2 and the course of CoVid-19 show that children play a much less significant role in the spread of the virus than do adults.

According to the findings available to date, not only do children and adolescents less frequently fall ill with CoVid-19, they also generally become less severely ill than do adults. The vast majority of infections in children and adolescents are asymptomatic or oligosymptomatic. Even the first analyses from China demonstrated that children and adolescents play a subordinate role in the transmission of the virus – not only to other children and adolescents, but also to adults.

Taking into account regional infection rates and available resources, daycare centers, kindergartens and elementary schools promptly should be reopened. For children, this should be possible without excessive restrictions, such as clustering into very small groups, implementation of barrier precautions, maintaining appropriate distance from others or wearing masks. A factor more decisive than individual group size is the issue of sustaining the constancy of respective group members and the avoidance of intermixing. Children can be taught basic rules of hygiene such as handwashing and careful hygiene behavior when coming into contact with others during mealtimes and/or when using sanitary facilities. Independent of the prevention measures implemented for children and adolescents, the protection of teachers, educators and caregivers is crucial, (e.g., the maintenance of appropriate distance from others, use of medical masks, situation-dependent hand disinfection, when necessary, supported by regular pool testing). Children over the age of 10 and adolescents up to school graduation age are more capable of actively understanding and conforming to specific hygiene rules. For this group, maintaining appropriate distance from others (1.5 meters), wearing a mouth-and-nose protection (whenever they are not sitting in their assigned classroom seats) and consistent education regarding the basic rules of infection prevention may provide increased options for normalizing teaching activities. Children and adolescents suspected of infection with SARS-CoV-2 should be tested immediately in order to either confirm or rule out such an infection. Evidence of individual infections in children or students must not automatically lead to the closure of the entire daycare center or school. A detailed analysis of the chain of infection is a prerequisite for a balanced approach to infection control. The opening of schools and children’s facilities should be accompanied by specifically structured, model surveillance studies that further clarify outstanding questions about infectious disease events and hygiene control. These prospective, concomitant examinations will be essential for the purpose of evaluating and verifying the effectiveness of the required hygiene measures.

Test methods for surface disinfection: comparison of the Wiperator ASTM standard E2967-15 and the 4-field test EN 16615

Aim: Two test methods for surface disinfection (phase 2, step 2) – the Wiperator method (ASTM standard E2967-15) and the 4-field test (EN 16615) – were compared using a disinfectant solution based on quaternary ammonium compounds and a ready-to-use alcohol-based wipe. As test organisms, Staphylococcusaureus and Pseudomonasaeruginosa were used.

Results: While the 4-field test is a manual method and better reflects the process in practice, with the Wiperator, the wiping process is better controlled because it is an automated procedure. A comparison of the effects of both methods on the target log₁₀-reduction of S. aureus and P. aeruginosa indicates a statistically significant difference between the two test methods (Mann-Whitney U-Test. S. aureus: 0 (U_min)<4 (U_crit); n₁=8, n₂=8, p=0.001; 2-sided. P. aeruginosa: 24 (U_min)<26 (U_crit); n₁=11, n₂=10, p=0.025, 2-sided). In addition, the results indicate that the wipe used has a major influence on the success of the disinfection process.

Discussion: Both methods are suitable for efficacy studies of surface disinfectants, yet they differ in some aspects. Additionally our data indicate a statistically significant difference between the two test methods.

Conclusion: Efficiency testing of surface disinfection is a complex process that depends on many different parameters. Since the 4-field test better reflects the practice, it makes sense to stick to this test procedure, taking into account that the EN 16615 was approved by CEN TC 216 in 2015 after method validation ring trials.

Questionnaire based evaluation of the motivation of surgically treated patients to participate in preventative hygiene measures

Background: Nosocomial infections caused by antibiotic-resistant pathogens demonstrate the continued need for preventive hygiene management strategies. Information and training of patients in their personal hygiene is a current requirement of the German Society for Hospital Hygiene, and is recommended by the Commission for Hospital Hygiene and Infection Prevention (Kommission für Krankenhaushygiene und Infektionsprävention beim Robert-Koch Institut, KRINKO) at the Robert Koch Institute.

Aim: The aim of this study was to evaluate patients’ existing knowledge of hygiene and their motivation to actively participate in preventive hygiene measures.

Methods: This study included 445 inpatients at the Polyclinic for Surgery of University Hospital Bonn. Subjects were interviewed over a 6-month period using a questionnaire comprising 21 questions on the topic of hygiene.

Results: The majority of patients rated their subjective level of knowledge as intermediate (41%), 25% as poor and 35% as high. The respondents rated the active inclusion of patients in hygiene practices as highly relevant, and were willing to actively contribute to infection prevention, whereby the patients considered hand washing and hand disinfection in particular as important starting points. 78% of the respondents wanted more information on hygiene, particularly on wound and food hygiene. Targeted hygiene education provided by hospital staff had a positive effect on the patients’ subjective level of information, as well as on their confidence in physicians and nursing staff. Previous information via television or radio had a negative impact on the patients’ subjective information level and on their confidence in hospital staff.

Conclusion: Most surgically treated patients are motivated to actively contribute to preventive hygiene measures. This represents an additional and important option for applying hospital hygiene more effectively and, above all, closer to the patient. Information and education should preferably be performed by healthcare professionals.

Association between antibiotic residues, antibiotic resistant bacteria and antibiotic resistance genes in anthropogenic wastewater - An evaluation of clinical influences

The high use of antibiotics in human and veterinary medicine has led to a wide spread of antibiotics and antimicrobial resistance into the environment. In recent years, various studies have shown that antibiotic residues, resistant bacteria and resistance genes, occur in aquatic environments and that clinical wastewater seems to be a hot spot for the environmental spread of antibiotic resistance. Here a representative statistical analysis of various sampling points is presented, containing different proportions of clinically influenced wastewater. The statistical analysis contains the calculation of the odds ratios for any combination of antibiotics with resistant bacteria or resistance genes, respectively. The results were screened for an increased probability of detecting resistant bacteria, or resistance genes, with the simultaneous presence of antibiotic residues. Positive associated sets were then compared, with regards to the detected median concentration, at the investigated sampling points. All results show that the sampling points with the highest proportion of clinical wastewater always form a distinct cluster concerning resistance. The results shown in this study lead to the assumption that ciprofloxacin is a good indicator of the presence of multidrug resistant P. aeruginosa and extended spectrum β-lactamase (ESBL)-producing Klebsiella spec., Enterobacter spec. and Citrobacter spec., as it positively relates with both parameters. Furthermore, a precise relationship between carbapenemase genes and meropenem, regarding the respective sampling sites, could be obtained. These results highlight the role of clinical wastewater for the dissemination and development of multidrug resistance.

Air quality in the operating room: Surgical site infections, HVAC systems and discipline - position paper of the German Society of Hospital Hygiene (DGKH)

In recent years, there has been an ongoing discussion about the value of laminar airflow (LAF=low turbulence displacement ventilation) in the operating room for prevention of surgical site infections (SSI). Some publications, e.g., from the WHO, issued the demand to no longer build LAF ceilings in operating rooms. The present statement deals critically with this position and justifies the use of LAF ceilings in different ways: Many of the papers cited by the WHO and others for the case against LAF do not provide reliable data.The remaining studies which might be used for answering the question give quite different results, also in favor of LAF.The size of the LAF ceiling in many studies is not given or mostly too small in comparison to actual technical requirements.LAF in different countries can mean quite different techniques (e.g., the US in comparison to Germany) so that the results of studies that do not take this into account may not be comparable.LAF has positive effects in terms of reducing particulate and bacterial load, associated with increased airflow in the surgical working area. A reduction of carcinogenic substances in the air may also be assumed, which would increase workers' safety. Thus, this paper recommends building LAF ceilings in the future as well, depending on the operations intended. Further, this paper gives an overview of possible reasons for surgical site infections and highlights the importance of discipline in the operating theatre.

[Personal preconditions for the prevention of nosocomial infections-guidelines of the German Commission for Hospital Hygiene and Infection Prevention (KRINKO), federal state hygiene regulations in Germany, and compliance by hospitals in Frankfurt am Main]

According to the amendment of the Infection Protection Act (2011), § 23, 8, all federal states in Germany had to pass their own hospital hygiene regulations, in which the need for hygiene specialists in a hospital is defined.This publication explains in its first part the differences between the nationwide Commission for Hospital Hygiene and Infection Prevention (KRINKO) regulations and the hygiene regulations of the different federal states (Hesse, Bavaria, etc.). All federal states - with the exception of Hesse (Hessian Hygiene Regulation, HHygVO) - refer to the relevant expert recommendations of KRINKO.In a second part of this publication, we highlight differences between KRINKO and HHygVO with the example of hospitals in the city of Frankfurt. In 2017, all Frankfurt hospitals had the necessary hygiene specialists (authorized hygiene practitioners, infection control nurses, authorized hygiene care nurses). However, the need for hospital hygienists could not be met, because there is an insufficient number of physician specialists for hospital hygiene available in Germany.The hospitals cannot solve this problem on their own - a political, superordinate decision and regulation must be made, i. e. by regulation and financial support for the advanced training of post-graduate physicians in hygiene. This is important since only experienced hospital hygienists can instruct or supervise hygiene specialists-in-training.

Interlaboratory reproducibility of a test method following 4-field test methodology to evaluate the susceptibility of Clostridium difficile spores

BACKGROUND

Sporicidal surface disinfection is recommended to control transmission of Clostridium difficile in healthcare facilities. EN 17126 provides a method to determine the sporicidal activity in suspension and has been approved as a European standard. In addition, a sporicidal surface test has been proposed.

AIM

To determine the interlaboratory reproducibility of a test method for evaluating the susceptibility of a C. difficile spore preparation to a biocidal formulation following the 4-field test (EN 16615 methodology).

METHODS

Nine laboratories participated. C. difficile NCTC 13366 spores were used. Glutaraldehyde (1% and 6%; 15 min) and peracetic acid (PAA; 0.01% and 0.04%; 15 min) were used to determine the spores' susceptibility in suspension in triplicate.

FINDINGS

One-percent glutaraldehyde revealed a mean decimal log₁₀ reduction of 1.03 with variable results in the nine laboratories (0.37-1.49) and a reproducibility of 0.38. The effect of 6% glutaraldehyde was stronger (mean: 2.05; range: 0.96-4.29; reproducibility: 0.86). PAA revealed similar results. An exemplary biocidal formulation based on 5% PAA was used at 0.5% (non-effective concentration) and 4% (effective concentration) to determine the sporicidal efficacy (4-field test) under clean conditions in triplicate with a contact time of 15 min. When used at 0.5% it demonstrated an overall log₁₀ reduction of 2.68 (range: 2.35-3.57) and at 4% of 4.61 (range: 3.82-5.71). The residual contamination on the three primarily uncontaminated test fields was <50 cfu/25 cm² in one out of nine laboratories (0.5%) and in seven out of nine laboratories (4%).

CONCLUSION

The interlaboratory reproducibility seems to be robust.

[Facial necrosis caused by orthopoxvirus : Differential diagnosis and dermatohistopathological correlation of infectious facial ulcers]

This article reports the remarkable course of a facial ulcer in a patient receiving prednisolone for Crohn's disease. Based on the initially unclear origin of the ulcer the patient received a triple anti-infective treatment (antiviral, antibiotic, antimycotic) but the lesion showed a rapid progression. An orthopoxvirus infection could be verified later by extensive diagnostics and relevant differential diagnoses could be ruled out. Extensive necrotic changes were observed in the first weeks resulting in cicatricial healing after months. Human cowpox infections have been repeatedly reported in Germany and are a relevant zoonosis. Cats and rodents are main carriers. The differential diagnoses include infections caused by other bacterial, mycobacterial, mycotic and parasitic agents that are thoroughly discussed here both clinically and histopathologically. Especially cutaneous leishmaniasis must be named as the incidence is continuously rising. With inadequate treatment infectious facial ulcers may give rise to life-threatening complications and extensive disfiguring scarring, therefore treatment must be initiated in a timely manner.

Antibiotic resistant bacteria and resistance genes in biofilms in clinical wastewater networks

Increasing isolation rates of resistant bacteria in the last years require identification of potential infection reservoirs in healthcare facilities. Especially the clinical wastewater network represents a potential source of antibiotic resistant bacteria. In this work, the siphons of the sanitary installations from 18 hospital rooms of two German hospitals were examined for antibiotic resistant bacteria and antibiotic residues including siphons of showers and washbasins and toilets in sanitary units of psychosomatic, haemato-oncological, and rehabilitation wards. In addition, in seven rooms of the haemato-oncological ward, the effect of 24 h of stagnation on the antibiotic concentrations and MDR (multi-drug-resistant) bacteria in biofilms was evaluated. Whereas no antibiotic residues were found in the psychosomatic ward, potential selective concentrations of piperacillin, meropenem and ciprofloxacin were detected at a rehabilitation ward and ciprofloxacin and trimethoprim were present at a haemato-oncology ward. Antibiotic resistant bacteria were isolated from the siphons of all wards, however in the psychosomatic ward, only one MDR strain with resistance to piperacillin, third generation cephalosporins and quinolones (3MRGN) was detected. In contrast, the other two wards yielded 11 carbapenemase producing MDR isolates and 15 3MRGN strains. The isolates from the haemato-oncological ward belonged mostly to two specific rare sequence types (ST) (P. aeruginosa ST823 and Enterobacter cloacae complex ST167). In conclusion, clinical wastewater systems represent a reservoir for multi-drug-resistant bacteria. Consequently, preventive and intervention measures should not start at the wastewater treatment in the treatment plant, but already in the immediate surroundings of the patient, in order to minimize the infection potential.

Legionella occurrence in municipal and industrial wastewater treatment plants and risks of reclaimed wastewater reuse: Review

Wastewater treatment plants (WWTPs) have been identified as confirmed but until today underestimated sources of Legionella, playing an important role in local and community cases and outbreaks of Legionnaires' disease. In general, aerobic biological systems provide an optimum environment for the growth of Legionella due to high organic nitrogen and oxygen concentrations, ideal temperatures and the presence of protozoa. However, few studies have investigated the occurrence of Legionella in WWTPs, and many questions in regards to the interacting factors that promote the proliferation and persistence of Legionella in these treatment systems are still unanswered. This critical review summarizes the current knowledge about Legionella in municipal and industrial WWTPs, the conditions that might support their growth, as well as control strategies that have been applied. Furthermore, an overview of current quantification methods, guidelines and health risks associated with Legionella in reclaimed wastewater is also discussed in depth. A better understanding of the conditions promoting the occurrence of Legionella in WWTPs will contribute to the development of improved wastewater treatment technologies and/or innovative mitigation approaches to minimize future Legionella outbreaks.

Isopropanol at 60% and at 70% are effective against 'isopropanol-tolerant' Enterococcus faecium

The bactericidal activity of isopropanol was determined against Enterococcus faecium ATCC 6057, ST 796 (isopropanol-tolerant strain) and Enterococcus hirae ATCC 10541 (EN 13727). Isopropanol at 60% and 70% were effective (≥5.38 log₁₀-reduction) in 15 s against all strains but 23% isopropanol was not (<0.99 log₁₀-reduction in ≤15 min). Isopropanol at 70% was tested against E. faecium in the four-field test. Eight millilitres was not effective enough in 1 min (<5 log₁₀-reduction), whilst 16 mL was effective (≥5.85 log₁₀-reduction). Healthcare workers can be reassured that 60% and 70% isopropanol with an appropriate volume are effective against E. faecium.

The occurrence of antimicrobial substances in toilet, sink and shower drainpipes of clinical units: A neglected source of antibiotic residues

Antibiotics represent one of the most important drug groups used in the management of bacterial infections in humans and animals. Due to the increasing problem of antibiotic resistance, assurance of the antibacterial effectiveness of these substances has moved into the focus of public health. The reduction in antibiotic residues in wastewater and the environment may play a decisive role in the development of increasing rates of antibiotic resistance. The present study examines the wastewater of 31 patient rooms of various German clinics for possible residues of antibiotics, as well as the wastewater of five private households as a reference. To the best of our knowledge, this study shows for the first time that in hospitals with high antibiotic consumption rates, residues of these drugs can be regularly detected in toilets, sink siphons and shower drains at concentrations ranging from 0.02 μg·L^-1 to a maximum of 79 mg·L^-1. After complete flushing of the wastewater siphons, antibiotics are no longer detectable, but after temporal stagnation, the concentration of the active substances in the water phases of respective siphons increases again, suggesting that antibiotics persist through the washing process in biofilms. This study demonstrates that clinical wastewater systems offer further possibilities for the optimization of antibiotic resistance surveillance.

Lelliottia aquatilis sp. nov., isolated from drinking water

Five beige-pigmented, oxidase-negative bacterial isolates, 6331-17^T, 6332-17, 6333-17, 6334-17 and 9827-07, isolated either from a drinking water storage reservoir or drinking water in 2006 and 2017 in Germany, were examined in detail applying by a polyphasic taxonomic approach. Cells of the isolates were rod-shaped and Gram-stain-negative. Comparison of the 16S rRNA gene sequences of these five isolates showed highest sequence similarities to Lelliottia amnigena (99.98 %) and Lelliottia nimipressuralis (99.99 %). Multilocus sequence analyses based on concatenated partial rpoB, gyrB, infB and atpD sequences confirmed the clustering of these isolates with Lelliottia species, but also revealed a clear distinction to the closest related type strains. Analysis of the genome sequences of these isolates indicated >70 % in silico DNA-DNA hybridization and high average nucleotide identities between strains. Nevertheless, they showed only <70 and <95 % similarity to the type strains of these two Lelliottia species. The fatty acid profiles of these isolates were very similar and consisted of the major fatty acids C16:0, C17 : 0cyclo, C15 : 0iso 2-OH/C16 : 1ω7c and C18 : 1ω7c. In addition, physiological/biochemical tests revealed high phenotypic similarity to each other. These cumulative data indicate that these isolates represent a novel Lelliottia species, for which the name Lelliottia aquatilis sp. nov. is proposed, with strain 6331-17^T (=CCM 8846^T=CIP 111609^T=LMG 30560^T) as the type strain.