Enterovirga aerilata sp. nov. and Knoellia koreensis sp. nov., isolated from an automobile air conditioning system.

Two strictly aerobic and rod-shaped bacteria, labelled as DB1703T and DB2414ST, were obtained from an automobile air conditioning system. Strain DB1703T was Gram-stain-negative, while strain DB2414ST was Gram-stain-positive. Both strains were catalase-positive and oxidase-negative. Strains DB1703T and DB2414ST were able to grow at 18-42 °C. Strain DB1703T grew within a NaCl range of 0-3 % and a pH range of 6.0-8.0; while strain DB2414ST grew at 0-1 % and pH 6.5-8.5. The phylogenetic and 16S rRNA gene sequence analysis indicated that strains DB1703T and DB2414ST belonged to the genera Enterovirga and Knoellia, respectively. Strain DB1703T showed the closest phylogenetic similarity to Enterovirga rhinocerotis YIM 100770T (94.8 %), whereas strain DB2414ST was most closely related to Knoellia remsis ATCC BAA-1496T (97.7 %). The genome sizes of strains DB1703T and DB2414ST were 4 652 148 and 4 282 418 bp, respectively, with DNA G+C contents of 68.8 and 70.5 mol%, respectively. Chemotaxonomic data showed Q-10 as the sole ubiquinone in DB1703T and ML-8 (H4) in DB2414ST. The predominant cellular fatty acid in DB1703T was summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), whereas iso-C16 : 0, C17 : 1 ω8c, and iso-C15 : 0 were dominant in DB2414ST. Overall, the polyphasic taxonomic comparisons showed that strains DB1703T and DB2414ST were distinct from their closest taxa and represent novel species within the genera Enterovirga and Knoellia, respectively. Accordingly, we propose the names Enterovirga aerilata sp. nov., with the type strain DB1703T (=KCTC 72724T=NBRC 114759T), and Knoellia koreensis sp. nov., with the type strain DB2414ST (=KCTC 49355T=NBRC 114620T).

Filters of automobile air conditioning systems as in-car source of exposure to infections and toxic moulds.

The main component of an air conditioning system is air filters. Over time, the filters of an air conditioning system in cars can turn into sources of emission of microbiological hazards. The aim of this study was to quantitatively and qualitatively assess the presence of infectious and toxic fungi in the AC filters in passenger cars. The studied non-woven filters were removed from passenger cars during the "winter"/"summer" seasons. The taxonomic identification of the fungi isolated from the filters was performed using both the culture-based and molecular methods. RT-PCR was applied to assess the presence of gene fragments regulating aflatoxin biosynthesis in the isolates obtained from fungal cultures. The average fungal concentrations in the filter samples collected during the summer/winter season were 5.4 × 104 cfu/m2 and 2.4 × 104 cfu/m2, respectively. Most of the filter samples, collected in both the studied seasons, revealed the presence of Aspergillus species including A. fumigatus, A. niger, A. terreus and/or A. flavus. The recorded levels of fungal contamination of AC filters in passenger cars indicate the necessity for more frequent filter replacement in this type of vehicle. Occupational exposure to moulds and the resulting health problems that may be experienced by professional drivers should be properly recognised in order to undertake effective preventive measures.

Fuzzy Logic Controlled Simulation in Regulating Thermal Comfort and Indoor Air Quality Using a Vehicle Heating, Ventilation, and Air-Conditioning System.

Conventional heating ventilation and air-conditioning (HVAC) controllers have been designed to mainly control the temperature of a confined compartment, such as a room or a cabin of a vehicle. Other important parameters related to the thermal comfort and indoor air quality (IAQ) of the confined compartment have often been ignored. In this project, IAQ in the vehicle cabin was represented by its carbon dioxide (CO2) concentration, and the occupants' thermal comfort levels were estimated with the predicted mean vote (PMV) index. A new fuzzy logic controller (FLC) was designed and developed using the MATLAB fuzzy logic toolbox and Simulink to provide a nonlinear mapping between the measured values, i.e., PMV, temperature, CO2, and control parameters (recirculation flaps, blower's speed, and refrigerant mass flow rate) of a vehicle HVAC system. The new FLC aimed to regulate both in-cabin PMV and CO2 values without significantly increasing overall energy consumption. To evaluate the effectiveness of the proposed FLC, a cabin simulator was used to mimic the effects of different HVAC variables and indoor/outdoor environmental settings, which represented the in-cabin PMV and IAQ readings. Results demonstrated that the new FLC was effective in regulating the in-cabin PMV level and CO2 concentration, at desirable levels, by adaptively controlling the opening and closing of the recirculation flap based on in-cabin temperature and CO2 readings, while maintaining an average-to-good energy consumption level. The proposed FLC could be applied to a large variety of HVAC systems by utilizing low-cost sensors, without the need to significantly modify the internal design of the HVAC system.

Legionella pneumophila contamination in central air-conditioning systems of public places in China：a meta-analysis / 预防医学

Objective @#To systematically evaluate the detection of Legionella pneumophila in central air-conditioning systems of public places in China, so as to provide insights into the management of L. pneumophila contamination.@*Methods@#The publications pertaining to L. pneumophila contamination in central air-conditioning systems of public places in China were searched in international and national databases, including CNKI, Wanfang Data, CBM, PubMed and Web of Science from January 1, 2010 to December 31, 2022. The publication quality was evaluated using the Strengthening the Reporting of Observational Studies in Epidemiology. A meta-analysis was performed using the software Stata version 16.0. The pooled detection of L. pneumophila and its 95%CI were estimated. The publication bias was evaluated using Begg's test, and sensitivity analysis was performed with the leave-one-out evaluation for assessment of the robustness of the outcomes.@*Results@#A total of 742 publications were initially searched, and 29 publications were finally included, all of which were cross-sectional studies. The publications included 10 high-quality and 19 moderate-quality studies covering 6 160 samples, and the pooled detection of L. pneumophila was 17.20% (95%CI: 12.80%-21.90%). Subgroup analysis showed a higher detection rate of L. pneumophila in cooling water (21.80%) than in condensed water (5.50%) (P<0.01). According to the criteria defined in Hygienic Specification of Central Air-conditioning Ventilation System in Public Buildings (2006 version), the detection of L. pneumophila was 23.30%, which was higher than the detection (13.20%) according to the Hygienic Specification of Central Air-conditioning Ventilation System in Public Buildings (WS 394-2012) (P<0.05). The detection of L. pneumophila did not vary in place, region or sample (P>0.05). Begg's test showed no significant publication bias, and sensitivity analysis showed robustness of the results. @*Conclusions@#The detection of L. pneumophila ranges from 12.80% to 21.90% in central air-conditioning systems of public places in China. Health and environmental protection sectors need to improve the monitoring of L. pneumophila contamination in central air-conditioning systems of public places.

Microbial contamination characteristics of centralized air conditioning systems in star-rated hotels based on metagenomic sequencing / 环境与职业医学

Background The use of heating and ventilation air conditioning (HVAC) in public places is conducive to improving indoor air quality and increasing the users comfort level. However, HVAC may also become potential carriers of indoor airborne microbial contamination. Objective To understand the characteristics of microbial pollution and distribution of related pathogenic microorganisms in HVAC of star-rated hotels, and to provide a basis for effective control of such pollution. Methods According to the requirements of the Hygienic specification of central air conditioning ventilation system in public buildings (WS 394-2012), two sets of HVAC in two star-rated hotels (A and B, inaugurated in 2002 and 1998, respectively) in the central area of Shanghai were randomly selected on September 9, 2020 for the hygienic evaluation of microorganisms in the air supply and respirable particulate matter (PM10) in the air supply, dust accumulation and microorganisms on the inner surface of the ducts, as well as Legionella pneumophila in cooling water and condensate water. At the same time, 3 samples from the inner surface of ducts, 1 sample from the surface of the filter, 1 sample from the condensate, and 1 sample from the cooling water were collected from each set of HVAC, a total of 12 sample from 2 sets of HVAC, for Illumina HiSeq metagenomic sequencing，and the samples are divided into 3 groups according to their types: duct group, filter group, and water sample group. The α-diversity indices (Shannon index, Simpson index, Chao1 index, ACE index, and goods_coverage index) were calculated to reflect the microbial community composition; and the β-diversity of the three groups were studied by principal component analysis to determine the similarity of the microbial communities. Results The maximum total number of bacteria and fungi in the air supply of the HVAC were 1158 CFU·m−3 and 344 CFU·m−3 for Hotel A respectively; and 2000 CFU·m−3 and 532 CFU·m−3 for Botel B respectively. β-hemolytic streptococci were negative in all samples; the respirable particulate matter, microorganisms and dust accumulation on the inner surface of air ducts, Legionella pneumophila IN cooling water and condensate samples all met the standards. The results of Illumina HiSeq sequencing showed that a total of 17322 microorganisms were reported in the 12 samples, with bacterial microbiota accounting for 97.31% of the classified genes and the remaining 2.69% were from fungi, viruses, and parasites. At the species level, Staphylococcus epidermidis, Pseudomonas, Alternaria, and Malassezia were the dominant microbial taxa measured in this survey. The results of α-diversity analysis showed that the values of Shannon index, Simpson index, and Chao1 index for the three groups of samples were duct > filter > water sample. The goods coverage indices of all sample groups s were close to 1. The principal component analysis showed that the contributions of two principal components were 19.27% and 14.25%, respectively, in which the samples of the filter and duct groups were better clustered into one category. Conclusion The overall hygiene conditions of the two hotels are good, except for the serious microbial contamination in the air supply of HVAC. Metagenomic sequencing reveals complex microbial communities of HVAC, including bacteria, fungi, viruses, and parasites. The species composition vary by sample groups, particularly the species compositions of the samples from filters and ducts are close and dominated by pathogenic microorganisms of human origin, suggesting that the potential biosafety hazards of HVAC should not be ignored.

A study on heat transfer load in large space buildings with stratified air-conditioning systems based on building energy modeling: Model validation and load analysis.

The characteristics of heat transfer load from the non-air-conditioned (NAC) area can help to understand the complex airflow movement and thermal physical mechanisms inside large space buildings. Based on building energy modeling, the indoor thermal environment and building energy consumption of a plant for computerized numerical control (CNC) machine tools are studied. Considering the form of the stratified air-conditioning system and the phenomenon of heat retention near the roof in the plant, the double zone and triple zone models are established. The vertical air temperature, the parameters of the terminal of the air-conditioning system and the heat/cool source system of the plant in summer and winter were measured on site, which verifies the accuracy of the established model. Based on the validated model, the proportion of heat transfer load from the NAC area is calculated, at the range of about 60%-85%. The positive influence of the roof heat transfer coefficient on the sensible heat load in the NAC area is revealed. The recommended value of the non-dimensional zone-mixing flow rate between the air-conditioned (AC) and NAC areas is given, with 30% (in summer). The results of this work can help understand the composition of the stratified air-conditioning load in large spaces and optimize the design of air distribution.

Metallococcus carri gen. nov., sp. nov., a novel member of the family Dermacoccaceae isolated from an automotive air conditioning system.

Strain designated DB0510T was isolated from an automobile evaporator core collected in Korea. Cells are gram-stain-positive, aerobic, and coccoid. The strain grew at 15-45 â„ƒ, pH 5.0-8.5 and 0-8.0% (w/v) NaCl. Growth occurs on R2A, trypticase soy agar, Luria-Bertani agar, and nutrient agar. Phylogenetic analysis showed that the strain belongs to the family Dermacoccaceae and strain DB0510T was distinctly separated from validly named genera of this family. Signature nucleotides in 16S rRNA gene sequence revealed that the strain contained the Dermacoccaceae family-specific 16S rRNA signature nucleotides patterns. The major fatty acids were C17:0 and C17:1 cis-9. The only menaquinone was MK-8 (H4). The polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannoside, and two unidentified lipids. The diagnostic cell-wall amino acid at position 3 of the peptide subunit was found to be lysine. The cell-wall peptidoglycan contained alanine, aspartic acid, glutamic acid, glycine, lysine, and serine and thus the peptidoglycan type was concluded to be of A4α type with Lys-Gly-Ser-Asp interpeptide bridge. The genome size was 3.49 Mbp and G + C content of the genome DNA was 69.4 mol%. On the basis of the phenotypic, genomic, and chemotaxonomic characteristics, strain DB0510T is considered to represent a novel genus and species within the family Dermacoccaceae, for which the name Metallococcus carri gen. nov., sp. nov. is proposed. The type strain of Metallococcus carri is DB0510T (= KACC 19663 T = NBRC 113349 T).

Schlegelella koreensis sp. nov., isolated from evaporator core of automobile air conditioning system.

A white-coloured, aerobic, and rod-shaped bacterium, designated strain ID0723T was isolated from evaporator core of automobile air conditioning system. The strain was Gram-stain-negative, catalase positive, oxidase negative, and grew at pH 5.5-9.5, at temperature 18-37 °C, and at 0-2.0% (w/v) NaCl concentration. The phylogenetic analysis and 16S rRNA gene sequence data revealed that the strain ID0723T was affiliated to the genus Schlegelella, with the closest phylogenetic member being Schlegelella brevitalea DSM 7029 T (98.1% sequence similarity). The chemotaxonomic features of strain ID0723T were diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine as the main polar lipids; Q-8 as an only ubiquinone; and summed feature 3 (C16:1ω7c and/or C16: 1ω6c), C16:0, and summed feature 8 (C18:1ω7c/or C18:1ω6c) as the major fatty acids. The average nucleotide identity (ANI) and in silico DNA-DNA hybridization values between strain ID0723T and S. brevitalea DSM 7029 T were 74.8% and 20.0%, respectively, which were below the cut-off values of 95% and 70%, respectively. The DNA G + C content was 69.9 mol%. The polyphasic taxonomic data clearly indicated that strain ID0723T represents a novel species in the genus Schlegelella for which the name Schlegelella koreensis sp. nov. is proposed, with the type strain ID0723T (= KCTC 72731 T = NBRC 114611 T).

Air conditioning condition of observation hotels for COVID-19 prevention and control / 上海预防医学

Objective:To investigate the hygienic condition and maintenance management of air conditioners in observation hotels， and give suggestions on reducing the risk of COVID-19 transmission from the daily use. Methods:This study selected 11 observation hotels chosen by government and 3 observation hotels chosen by large companies in Minhang District. The types and sanitary conditions of the air conditioning system were revealed through the daily supervision. Hotel staffs’ knowledge of air conditioning system and their mastery of how to use and maintain air conditioning system were surveyed through questionnaire. Results:Survey of air conditioning types showed that in 14 hotels， 12 were distributed air conditioning systems and 2 were semi-centralized air conditioning systems （including fresh air systems）. The investigation found that there was dust accumulation in the fresh air ducts in one hotel guest room， dust accumulation in the filter screen of fresh air intake in one hotel， and the sanitary problem of condensate water （without centralized discharge） in two hotels. All of 14 hotels had daily cleaning and disinfection records， but they were not perfect. The hotel health management personnel’ awareness rate of air conditioning was low， although they had a positive attitude towards the cleaning and disinfection of the air conditioning system. They could do the active entrusted testing， cleaning and disinfection of the air conditioning systems. Conclusion:The air conditioning systems of some hotels have hygiene problems， and hotel health management personnel are lack of knowledge of standard operation and maintenance of air conditioning systems. The air conditioning systems of observation hotel should be cleaned and disinfected before use. At the same time， it is necessary to strengthen the training of hotel health management personnel on the use and maintenance of air conditioning systems. So the transmission of the COVID-19 through air conditioning systems can be effectively prevented.

Mitigation of indoor human exposure to airborne particles of outdoor origin in an urban environment during haze and non-haze periods.

During the 2019 smoke haze episode in Singapore, elevated levels of fine particulate matter (PM2.5) were observed, deteriorating both ambient and indoor air quality (IAQ). We investigated the mitigation of indoor human exposure to PM2.5 of outdoor origin under diverse exposure scenarios with and without filtration of PM2.5 during both hazy and non-hazy days. The key objective of our study was to make a comparative evaluation of the effectiveness of portable air cleaners (PACs) and air conditioning (AC) systems equipped with particle filters in improving IAQ and to assess related long-term carcinogenic and non-carcinogenic health risks. We conducted real-time measurements of PM2.5, black carbon mass concentrations and particle number concentrations in both indoor and outdoor areas, quantified the relative concentrations of the water-soluble fraction of toxic trace elements in PM2.5 for health risk assessment, and estimated the levels of thermal comfort. In addition, we calculated the total estimated cost of indoor air pollution control. Our findings suggest that indoor air cleaners are more effective at mitigating human exposure to airborne particles and reducing health risk with less consumption of electricity and better cost-effectiveness compared to AC. This information would be beneficial for public health interventions during major air pollution events.

Environmental contamination of SARS-CoV-2 on surfaces, air-conditioner and ventilation systems.

BACKGROUND: COVID-19 can be transmitted directly through respiratory droplets or indirectly through fomites. SARS-CoV-2 has been detected on various environmental surfaces, air samples and sewage in hospital and community settings. METHODS: Environmental samples were collected from a ferryboat during a COVID-19 ongoing outbreak investigation and a nursing home and from three COVID-19 isolation hospital wards and a long-term care facility where asymptomatic COVID-19 cases were isolated. Samples were tested by real-time reverse transcriptase-polymerase chain reaction. RESULTS: SARS-CoV-2 was detected on swab samples taken from surfaces of food preparation and service areas, hospital isolation wards, an air exhaust duct screen, air-conditioning filter, sewage treatment unit and air sample during investigations conducted in response to COVID-19 outbreaks on a ferryboat, nursing home, isolation facility and COVID-19 hospital wards. DISCUSSION: Food preparation areas and utensils can be contaminated during COVID-19 outbreaks. Respiratory droplets/nuclei from infected persons can be displaced by the air flow and deposited on surfaces. It can be assumed that in the same manner, air flow could transfer and deposit infected respiratory droplets/nuclei from infected persons to the mucous membranes of persons standing against the air flow direction.

IoT Based Architecture for Model Predictive Control of HVAC Systems in Smart Buildings.

The efficient management of Heating Ventilation and Air Conditioning (HVAC) systems in smart buildings is one of the main applications of the Internet of Things (IoT) paradigm. In this paper we propose an IoT based architecture for the implementation of Model Predictive Control (MPC) of HVAC systems in real environments. The considered MPC algorithm optimizes on line, in a closed-loop control fashion, both the indoor thermal comfort and the related energy consumption for a single zone environment. Thanks to the proposed IoT based architecture, the sensing, control, and actuating subsystems are all connected to the Internet, and a remote interface with the HVAC control system is guaranteed to end-users. In particular, sensors and actuators communicate with a remote database server and a control unit, which provides the control actions to be actuated in the HVAC system; users can set remotely the control mode and related set-points of the system; while comfort and environmental indices are transferred via the Internet and displayed on the end-users' interface. The proposed IoT based control architecture is implemented and tested in a campus building at the Polytechnic of Bari (Italy) in a proof of concept perspective. The effectiveness of the proposed control algorithm is assessed in the real environment evaluating both the thermal comfort results and the energy savings with respect to a classical thermostat regulation approach.

Roseicella frigidaeris gen. nov., sp. nov., isolated from an air-conditioning system.

A Gram-stain-negative, facultatively aerobic bacterial strain, designated DB1506T, of the family Acetobacteraceae, was isolated from an air-conditioning system in the Republic of Korea. Colonies were pink- to rosy-coloured and cells were non-motile cocci with catalase- and oxidase-positive activities. Growth of strain DB1506T was observed at 20-37 °C (optimum, 30 °C), pH 5.5-8.5 (pH 7.0) and in the presence of 0-0.5 % (w/v) NaCl (0 %). Strain DB1506T contained summed feature 8 (comprising C18 : 1ω7c and/or C18 : 1ω6c) and C18 : 1 2-OH as major fatty acids and ubiquinone-10 as the sole isoprenoid quinone. Phosphatidylglycerol, phosphatidylethanolamine, unidentified phospholipids, unidentified aminolipids and unidentified polar lipids were detected as major polar lipids. The G+C content of the genomic DNA calculated from the whole genome sequence was 72.5 mol%. Strain DB1506T was most closely related to Paracraurococcus ruber NS89T, Dankookia rubra WS-10T and Siccirubricoccus deserti SYSU D8009T with 16S rRNA gene sequence similarities of 96.01, 95.88 and 95.44 %, respectively, but strain DB1506T formed a clearly distinct phylogenic lineage from them within the family Acetobacteraceae. On the basis of phenotypic, chemotaxonomic and molecular properties, strain DB1506T represents a novel species of a new genus within the family Acetobacteraceae, for which the name Roseicella frigidaeris gen. nov., sp. nov. is proposed. The type strain is DB1506T (=KACC 19791T=JCM 32945T).

Prevalence of Antibiotic Resistance Genes in Air-Conditioning Systems in Hospitals, Farms, and Residences.

High-throughput quantitative PCR combined with Illumina sequencing and network analysis were used to characterize the antibiotic resistance gene (ARG) profiles in air-conditioning filters from different environments. In total, 177 ARGs comprising 10 ARG types were determined. The detectable numbers and the relative abundance of ARGs in hospitals and farms were significantly higher than those in city and village residences. Compared to hospitals, farms had a higher level of tetracycline, multidrug, integrase, and macrolide⁻lincosamide⁻streptogramin (MLS) B resistance genes but a lower level of beta-lactam resistance genes. The bl3_cpha gene was the most abundant resistance gene subtype in hospital samples with an abundance of 2.01 × 10-4 copies/16S rRNA, while a level of only 5.08 × 10-12 copies/16S rRNA was observed in farm samples. There was no significant difference in bacterial diversity among the hospitals, farms, and residences, and Proteobacteria was the most abundant phylum. Network analysis revealed that Proteobacteria and Actinobacteria were possible hosts of the beta-lactam, MLSB, aminoglycoside, multidrug, sulfonamide, and tetracycline resistance genes. The results demonstrate that ARGs exist in indoor environments and that farms and hospitals are important sources. This study provides a useful reference for understanding the distribution patterns and risk management of ARGs in indoor environments.

Heating, ventilation and air conditioning (HVAC) system, microbial air contamination and surgical site infection in hip and knee arthroplasties: the GISIO-SItI Ischia study.

BACKGROUND: Recent studies have questioned the role of unidirectional airflow ventilation system in reducing surgical site infection (SSI) in prosthetic implant surgery. The aim of the ISChIA study ("Infezioni del Sito Chirurgico in Interventi di Artroprotesi" which means "Surgical site infections in arthroplasty surgery") was to evaluate, as a contribution to this debate, the association between heating, ventilation and air conditioning systems, microbial air contamination and surgical site infection in hip and knee arthroplasty. METHODS: The study was performed from March 2010 to February 2012 in 14 hospitals, for a total of 28 operating theatres: 16 were equipped with vertical unidirectional airflow ventilation (U-OTs), 6 with mixed airflow ventilation (M-OTs), 6 with turbulent airflow ventilation (T-OTs). Microbial air contamination in the operating theatre was evaluated by means of passive (Index of Microbial Air contamination, IMA) and active (Colony Forming Units per cubic metre, cfu/m3) sampling. SSI surveillance was carried out according to the Hospitals in Europe Link for Infection Control through Surveillance protocol. RESULTS: A total of 1,285 elective prosthesis procedures (61.1% hip and 38.9% knee) were included in the study. The results showed a wide variability of the air microbial contamination in operating theatres equipped with unidirectional airflow. The recommended values of ≤2 IMA and ≤10 cfu/m3 were exceeded, respectively, by 58.9% and 46.4% of samples from U-OTs and by 87.6% and 100% of samples from M-OTs. No significant difference was observed between SSI cumulative incidence in surgical procedures performed in U-OTs compared with those performed in T-OTs. A lower risk of SSI, even though not statistically significant, was shown in surgical procedures performed in U-OTs with a microbial air contamination within the recommended values (≤2 IMA and ≤10 cfu/m3) compared with those performed in U-OTs where these limits were exceeded, and compared with those performed in T-OTs with microbial air contamination within the recommended values for this type of OTs (≤25 IMA, ≤180 cfu/m3. CONCLUSION: ISChIA study did not show a protective effect of unidirectional airflow compared with turbulent airflow in arthroplasty surgery. However, the frequent exceeding of recommended air microbial contamination values in OTs equipped with unidirectional airflow, and the lower SSI risk in surgical procedures performed in compliant U-OTs compared with those performed in non-compliant U-OTs and with those performed in compliant T-OTs, suggest the need of further studies, which should consider air microbial contamination and other aspects of SSI prevention that may negate the potential benefits of the ventilation system; differences in intrinsic and extrinsic risk factors, medical treatment and surgical technique are also to be considered. Training interventions aimed at improving the behaviour of operators are essential.

Nocardioides currus sp. nov., isolated from a mobile car air-conditioning system.

A strictly aerobic Gram-stain-positive bacterial strain, designated IB-3T, was isolated from a car air-conditioning system in the Republic of Korea. Cells were non-motile rods showing catalase- and oxidase-positive reactions. Growth of IB-3T was observed at 20-40 °C (optimum, 25 °C), at pH 6.5-9.0 (optimum, pH 7.5) and in the presence of 0-1 % (w/v) NaCl (optimum, 0 %). Menaquinone-8 (H4) was detected as the predominant respiratory quinone and iso-C16 : 0, 10-methyl-C17 : 0, iso-C17 : 0, C18 : 1ω9c, C17 : 1ω8c, C18 : 0, 10-methyl-C18 : 0 (TBSA) and C17 : 0 were identified as the major cellular fatty acids. Phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine and phosphatidylinositol were detected as the major polar lipids. The major cell wall peptidoglycan type was ll-2,6-diaminopimelic acid. The G+C content of the genomic DNA was 71.5 mol%. IB-3T was most closely related to Nocardioides terrigenaDS-17T with a 98.0 % 16S rRNA gene sequence similarity. The results of phylogenetic analyses based on 16S rRNA gene sequences indicated that IB-3T formed a distinct phylogenetic lineage within the genus Nocardioidesof the family Nocardioidaceae. On the basis of the phenotypic, chemotaxonomic and molecular features, IB-3T represents a novel species of the genus Nocardioides, for which the name Nocardioidescurrus sp. nov. is proposed. The type strain is IB-3T (=KACC 19522T=JCM 32672T).

Filters from taxis air conditioning system: A tool to characterize driver's occupational exposure to bioburden?

Bioburden proliferation in filters from air conditioning systems of taxis represents a possible source of occupational exposure. The aim of this study was to determine the occurrence of fungi and bacteria in filters from the air conditioning system of taxis used for patient transportation and to assess the exposure of drivers to bioburden. Filters from the air conditioning systems of 19 taxis and 28 personal vehicles (used as controls) operating in three Portuguese cities including the capital Lisbon, were collected during the winter season. The occurrence and significance of bioburden detected in the different vehicles are reported and discussed in terms of colony-forming units (CFU) per 1 m2 of filter area and by the identification of the most frequently detected fungal isolates based on morphology. Azole-resistant mycobiota, fungal biomass, and molecular detection of Aspergillus species/strains were also determined. Bacterial growth was more prevalent in taxis (63.2%) than in personal vehicles (26.3%), whereas fungal growth was more prevalent in personal vehicles (53.6%) than in taxis (21.1-31.6%). Seven different azole-resistant species were identified in this study in 42.1% taxi filters. Levels of fungal biomass were above the detection limit in 63% taxi filters and in 75% personal vehicle filters. No toxigenic species were detected by molecular analysis in the assessed filters. The results obtained show that bioburden proliferation occurs widely in filters from the air conditioning systems of taxis, including the proliferation of azole-resistant fungal species, suggesting that filters should be replaced more frequently. The use of culture based-methods and molecular tools combined enabled an improved risk characterization in this setting.

Methylobacterium frigidaeris sp. nov., isolated from an air conditioning system.

A reddish pink-pigmented, Gram-stain-negative, aerobic and methylotrophic bacterial strain, designated strain IER25-16T, was isolated from a laboratory air conditioning system in the Republic of Korea. Cells were motile rods showing catalase- and oxidase-positive reactions. Strain IER25-16T grew at 10-40 °C (optimum, 30 °C), at pH 4.0-7.0 (optimum, pH 5.0-7.0) and in the presence of 0-1.0 % (w/v) NaCl (optimum, 0 %). The major respiratory quinone was ubiquinone-10 and ubiquinone-9 was also detected as the minor respiratory quinone. Summed feature 8 (comprising C18 : 1ω7c and/or C18 : 1ω6c) was detected as the predominant fatty acids. The genomic DNA G+C content of strain IER25-16T was 70.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that strain IER25-16T belonged to the genus Methylobacterium of the class Alphaproteobacteria. Strain IER25-16T was most closely related to Methylobacterium platani PMB02T (97.9 %), Methylobacterium aquaticum GR16T (97.9 %) and Methylobacterium tarhaniae N4211T (97.5 %). The average nucleotide identity and in silico DNA-DNA hybridization values between strain IER25-16T and M. platani, M. aquaticum and M. tarhaniae were 88.3, 88.8 and 89.6 % and 36.2, 37.3 and 39.3 %, respectively. The phenotypic and chemotaxonomic features and the phylogenetic inference clearly suggested that strain IER25-16T represents a novel species of the genus Methylobacterium, for which the name Methylobacteriumfrigidaeris sp. nov. is proposed. The type strain is strain IER25-16T (=KACC 19280T=JCM 32048T).

Roseomonas aeriglobus sp. nov., isolated from an air-conditioning system.

A novel pale pink-coloured, strictly aerobic, Gram-stain negative bacterial strain, designated strain KER25-12T, was isolated from a laboratory air-conditioning system in South Korea. Cells were observed to be non-motile cocci showing positive catalase and oxidase reactions. Strain KER25-12T was found to grow at 10-30 °C (optimum, 25-30 °C), at pH 4.0-9.0 (optimum, pH 6.0-7.0) and in the presence of 0-2% (w/v) NaCl (optimum, 0%). Ubiquinone-10 and spermidine were detected as the sole respiratory quinone and the predominant polyamine, respectively. The major fatty acids were identified as summed feature 8 (comprising C18:1 ω7c and/or C18:1 ω6c), summed feature 3 (comprising C16:1 ω7c and/or C16:1 ω6c), C16:0 and C18:0. The genomic DNA G+C content of strain KER25-12T was determined to be 70.0 mol%. The major polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and an unidentified aminolipid. Phylogenetic analysis based on 16S rRNA gene sequence comparison revealed that strain KER25-12T belongs to the genus Roseomonas and shows high sequence similarity to Roseomonas aerilata 5420S-30T (98.57%), Roseomonas pecuniae N75T (97.44%) and Roseomonas vinacea CPCC 100056T (97.40%). Based on the morphological, physiological, chemotaxonomic and phylogenetic features, strain KER25-12T is concluded to represent a novel species of the genus Roseomonas, for which the name Roseomonas aeriglobus sp. nov. is proposed. The type strain is KER25-12T (= KACC 19282T = JCM 32049T).

Spirosoma metallum sp. nov., isolated from an automobile air conditioning system.

A Gram-stain-negative and yellow-pigmented bacterial strain, designated TX0653T, was isolated from an automobile evaporator core collected in Korea. The cells were aerobic and rod-shaped. The strain grew at 10-28 °C (optimum, 25 °C), at pH 6.0-7.5 (optimum, 6.5), and in the presence of 0-1% (w/v) NaCl (optimum, 0%). Phylogenetically, the strain was related to members of the genus Spirosoma (95.1-90.8% 16S rRNA sequence similarity) and distantly related to Spirosoma pulveris JSH5-14T (95.1%), Spirosoma fluviale MSd3T (95.0%), Spirosoma endophyticum DSM 26130T (94.8%), and Spirosoma linguale DSM 74T (94.6%). The major fatty acids of the strain were summed feature 3 (C16:1 ω6c and/or C16:1 ω7c), C16:1 ω5c, iso-C15:0, iso-C17:0 3-OH, and C16:0. MK-7 was identified as the predominant menaquinone. The polar lipids profile indicated the presence of one phosphatidylethanolamine, one unidentified aminolipid, one unidentified aminophospholipid, two unidentified phospholipids, and three unidentified lipids. On the basis of the phenotypic, genotypic, and chemotaxonomic characteristics, strain TX0653T represents a novel species in the genus Spirosoma, for which the name Spirosoma metallum sp. nov. (= KACC 19278T = NBRC 112495T) is proposed.