Changes of the Microbiota Composition on the Surface of Pig Carcasses during Chilling and Its Associations with Alterations in Chiller’s Temperature and Air Humidity

In this study, we investigated changes of microbiota composition on the surface of pig carcasses during chilling and their associations with temporal and spatial changes of wind speed, air temperature, and air humidity. The composition of microbiota on a carcass surface varied greatly with sampling sites; in particular, the surfaces of forelegs and neck had higher load of microorganisms and different microbiota composition compared to in the air and other carcass parts. However, such a difference in the microbiota composition decreased as chilling time extended. The positive detection ratios of microbial genes resistant to sulfonamides, quinolones, tetracyclines, and β-lactams were found different greatly with chilling time and sampling sites. The β-lactam and tetracycline resistant genes were observed in higher ratios in airborne microorganisms in the chiller, while the sulfa and tetracycline resistant genes had higher ratios in the microbiota on pig carcasses. Actual measurements and dynamic simulation showed that air temperature and humidity varied greatly among different places in a chiller within the first 8 h of chilling, with higher values close to the door, but the differences became smaller afterwards. The micro-environmental differences and changes in the chiller may cause the different composition of microbiota on pig carcasses.

On-site Investigation of Airborne Bacteria and Fungi According to Type of Poultry Houses in South Korea

A field survey was conducted to quantify indoor exposure levels and emission rates of airborne microorganisms generated from domestic poultry buildings. There were three types of poultry buildings (caged layer house, broiler house, and layer house with manure belt), classified by the mode of manure treatment and ventilation, investigated in this study. Nine sites for each poultry building were selected and visited for measuring the exposure level and emission rate of airborne microorganisms. The total number of airborne bacteria and fungi among the airborne microorganisms were analysed based on the incubation method. Their emission rates were estimated by dividing the emission amount, which was calculated through multiplying indoor concentration (cfu/m3) by ventilation rate (m3/h), into the indoor area(m2) and the number of poultries reared in the poultry building. The mean exposure levels of the total airborne bacteria and fungi in the poultry building were 7.92 (SD:2.66) log (cfu m-3) and 4.92 (SD:1.79) log (cfu m-3), respectively. Emission rates of airborne microorganisms in poultry buildings were estimated to be 0.263 (±0.088) log (cfu hen-1h-1) and 0.839 (±0.371) log (cfu m-2h-1) for total airborne bacteria, and 0.066 (±0.031) log (cfu hen-1h-1) and 0.617 (±0.235) log (cfu m-2h-1) for total airborne fungi. The distribution patterns of the total airborne bacteria and fungi were similar regardless of poultry building type. Among poultry buildings, the broiler house showed the highest exposure level and emission rate of total airborne bacteria and fungi, followed by the layer house with manure belt and the caged layer house (p<0.05). The finding that the broiler house showed the highest exposure level and emission rate of airborne microorganisms could be attributed to sawdust, which can be dispersed into the air by the movement of the poultry when it is utilized as bedding material. Thus, a work environmental management solution for optimally reducing airborne microorganism exposure is necessary for the broiler house.

Environment-driven control of fungi in subterranean ecosystems: the case of La Garma Cave (northern Spain)

Airborne microorganisms can cause important conservation problems in caves with Paleolithic art and therefore the knowledge of cave aerodynamic is essential. La Garma Cave (Cantabria, Spain), an exceptional archaeological site with several levels of galleries interconnected and two entrances, presents a complex atmospheric dynamics. An approach including aerobiological sampling together with microclimate monitoring was applied to assess the factors controlling the origin of airborne fungi. Here we show that winter ventilation is critical for the increasing of Basidiomycota spores in the cave air and the highest concentrations were found in the most ventilated areas. On the contrary, Ascomycota spores prevailed in absence of ventilation. Besides, most Ascomycota were linked to insects and bats that visit or inhabit the cave. The combination of aerobiological and microclimate data constitutes a good approach to evaluate the influence of external climatic conditions and design the most suitable strategies for the conservation of cultural heritage in the cave environment.

Possible transmission of Covid-19 & precautions in a dental setting: A review

A severe pneumonia outbreak occurred in Wuhan City in late December 2019.Inhalation of airborne microorganisms that may remain in the air for a long time, direct blood contact, oral fluid or other patient material, connective contact with droplets and nasal or mouth mucosal microorganisms formed or proposed by an infected person transmitting pathogens to the dental environment for a short time.Contacts can also occur in a relatively closed environment where aerosols are exposed to high aerosol levels. Dental practice produces risky dentists and patients with aerosols.Therefore, the research aims to prevent infections in dental practices from hindering transmission routes between clinics and hospitals. Dentists played a significant role in stopping 2019-ncov transmission. In dental clinics and hospitals, infection control is advised to block routes from person to person.

Assessment of Potential Damage Factor: A Case Study of St. Paul’s Cathedral, Kolkata

Damaging factors such as airborne microorganisms, relative humidity, ventilation, temperature and air pollutants are the major concerns of the tropical climate of Kolkata, India where our study site, 172-year-old St. Paul’s Cathedral is located. In this context, the aim was to develop an equation to assess the management priority and which factors would be more responsible for potentially damaging the heritage building. The temperature varied from 28°C to 31°C, relative humidity was recorded 72% over a period of 14 days in the prayer hall whereas almost constant temperature (27°C) and relative humidity (55%) were recorded in crypt. Air movement was recorded 0.5–3 m s−1 in both crypt and prayer hall. Sulphur dioxide and oxide of nitrogen concentration were lower than the standard mentioned by the Central Pollution Control Board, India. The fungal load was lower inside the crypt (237 CFU m−3) than in the prayer hall (793 CFU m−3). Calculated potential damage for prayer hall and crypt was found to be 48.75% and 37.08%, respectively. Results revealed that microbial load and relative humidity were the potent factors for damage to the building. Continuous air movement, that is, ventilation and building design here played significant roles. The Heritage Conservation Committee can use the data for better management.

Assessment of Airborne Bacterial and Fungal Communities in Shahrekord Hospitals

This paper presents information about airborne microorganisms (bacteria and fungi) in the indoor air of two hospitals (Kashani and Hajar) in the city of Shahrekord, Iran. The settle plate technique using open Petri dishes containing different culture media was employed to collect a sample and using Quick Take 30 Sample Pump three days per week for a period of 8 weeks. Standard microbiological methods were employed for the identification of bacterial and fungal isolates. The results showed that the concentration of bacteria in the study area ranged from 0 to 70 cfu/plate/h, while the concentration of fungi was 0 to 280 cfu/plate/h. Also, 12 bacterial and 3 fungal species were isolated and identified with varying frequencies of occurrence, including Staphylococcus spp., Escherichia coli, Salmonella, Enterobacter, Pseudomonas, Serratia Citrobacter, Proteus, and Klebsiella, while the fungal genera isolated included Yeast, Aspergillus flavus, and Penicillium. While the bacterial isolates Staphylococcus aureus (20.50%) and Pseudomonas (9.10%) were the most predominant airborne bacteria, yeast (22.70%) and Penicillium (20.50%) were the most frequently isolated fungal species. The population of microorganisms was the highest during the afternoon. The statistical analysis showed a significant difference between the microbial loads of the two hospitals at P < 0.05 . The generated data underline the usefulness of monitoring the air quality of the indoor hospital.