Isolation and Identification of Airborne Bacteria Inside Swiftlet Houses in Sarawak, Malaysia

Environmental assessment of three egg production systems – Part III: Airborne bacteria concentrations and emissions

We assessed in this study the total airborne bacteria (TAB), gram-negative bacteria (GNB), and endotoxin (ET) concentrations in three Korean university laboratories and two hospital diagnostic laboratories categorized as biosafety level 1 (BL 1) or biosafety level 2 (BL 2). We also investigated the concentrations of TAB, GNB, and ET relative to the performance results of biosafety cabinets (BSCs). TAB and GNB were incubated, and ET was analyzed using the kinetic Limulus amebocyte lysate assay. A total of 246 (TAB = 95, GNB = 95, ET = 56) air samples were collected from nine laboratories. TAB, GNB, and ET concentrations were significantly higher in BL 1 laboratories and in laboratories that failed the BSC performance test compared to BL 2 laboratories and laboratories that passed the BSC performance test. Correlation coefficients were calculated to determine the relationships between TAB, GNB, and ET, and it was found that TAB significantly correlated with GNB (r = 0.35, p < .01) and ET (r = 0.29, p < .01). Careful attention needs to be paid to BL 1 laboratories, and BSCs should be managed on a regular basis to improve the air quality of university and hospital laboratories.

Objectives: The purpose of this study is to assess the exposure level to dust and airborne microorganisms among employed workers in a clothing shopping center. Materials and Methods: On-site investigation of a clothing shopping center was performed between October and November 2012. The hazardous substances measured in this study are particulate matter(Total dust, respirable dust) and airborne microorganisms (Total airborne bacteria, total airborne fungi). Results: The highest geometric mean levels of particulate matter(total dust, respirable dust) for personal sampling were 1.735(SD:0.883) ㎎/㎥ for total dust and 0.0711(SD:0.008) ㎎/㎥ for respirable dust, respectively. Those for area sampling were 0.625(SD:0.091) ㎎/㎥ for total dust and 0.0718(SD:0.012) ㎎/㎥ for respirable dust, respectively. The highest geometric averaged concentrations of airborne microorganisms(Total airborne bacteria, total airborne fungi) were detected at 1,181(SD:105) cfu/㎥ for total airborne bacteria and 683(SD:114) cfu/㎥ for total airborne fungi, respectively. Concentrations of particulate matters and airborne microorganism in clothes shopping center did not correlate significantly with environmental factors such as temperature or relative humidity. Conclusions: Exposure levelshave not been established for service workers. Thus, health risk assessment for this group is very difficult. Health guidelines for service workers should be established as soon as possible.

In the process of tea production and storage, mold is constantly multiplying due to improper production methods and environmental conditions. To realize the nondestructive detection of the total mold colony count in green tea, an accurate and rapid method based on visible–near‐infrared (431–962 nm) hyperspectral image was proposed. Firstly, the spectral data extracted from hyperspectral images was preprocessed and partial least squares regression model based on different preprocessing methods was established to determine the best preprocessing method. Then, competitive adaptive reweighted sampling (CARS) and variable combination population analysis were used to select the characteristic wavelengths and support vector regression (SVR) was introduced to establish quantitative detection model. Because the parameter setting of SVR directly affects the effect of the model, a combination of genetic algorithm (GA) and particle swarm optimization (PSO) was adopted to optimize the parameters c (penalty factor) and g (kernel function parameter). The results showed that based on the wavelength selected by CARS, the SVR model optimized by GA‐PSO (CARS‐GA‐PSO‐SVR) achieved accuracy with of 0.9577 and root mean square error of prediction set of 0.1140 lg(CFU/g). Therefore, hyperspectral imaging technology can realize the nondestructive determination of the total mold colony count in green tea.Practical applicationsSome molds, such as aspergillus and penicillium, are the main factors of tea mildew. These molds can produce mycotoxins such as aflatoxin and citreoviridin, which can not only cause damage to the tea quality, but also threaten the health of tea drinkers. In this paper, the total mold colony count of green tea was studied based on hyperspectral imaging technology. The experiment result indicated that the use of hyperspectral imaging technology can achieve accurate, nondestructive, and rapid detection of the total mold colony count in green tea. This research provides an effective solution to the quantitative detection of the total mold colony count in green tea.

A validation study was conducted to extend the matrix claim for the Nissui Compact Dry Total Count (TC), Performance Tested Method(s)(SM) (PTM) Certification No. 010404, to cooked chicken, lettuce, frozen fish, milk powder, and pasteurized whole milk. The method was originally certified by the AOAC Research Institute Performance Tested Method(s)(SM) Program for raw meat products. The Compact Dry TC is a ready-to-use dry media sheet that is rehydrated by adding 1 mL of diluted sample. A total aerobic colony count can be determined in the sample following 48 h of incubation. Matrix extension studies were conducted by Campden BRI (formerly Campden and Chorleywood Food Research Association Technology Limited), Chipping Campden, UK. Single-laboratory data were collected for cooked chicken, lettuce, frozen fish, and milk powder, whereas a multilaboratory study was conducted on pasteurized milk. Fourteen laboratories participated in the collaborative study. The Compact Dry TC was tested at two time points, 48 ± 3 h and 72 ± 3 h and compared with the current International Organization for Standardization (ISO) method at the time of the study, ISO 4833:2003 (this standard is withdrawn and has been replaced by: ISO 4833-1:2013 and ISO 4833-2:2013), Microbiology of food and animal feeding stuffs-Horizontal method for the enumeration of microorganisms-Colony-count technique at 30°C. The data were logarithmically transformed and evaluated for repeatability (plus reproducibility for pasteurized milk), RSD of repeatability (plus RSD of reproducibility for milk), r(2), and mean difference between methods with 95% confidence interval (CI). A CI outside of (-0.5 to 0.5) on the log10 mean difference was used as the criterion to establish significant statistical difference between methods. No significant differences were found between the Compact Dry TC 48 and 72 h time points, with the exception of one contamination level of cooked chicken and one contamination level of dry milk powder. Mean differences were small at these levels (<0.5 log10), but the upper CIs were above 0.5. Statistical differences were indicated between the Compact Dry TC and ISO 4833 in two of five contamination levels tested each for lettuce and frozen fish. In each case, mean differences were >0.5 log10, and the total aerobic colony count was higher for the ISO method. In most cases, mean differences between the Compact Dry and ISO methods were small (<0.5 log10) with CIs within the acceptance criterion. Repeatability, reproducibility, and RSD were similar for both methods, and r(2) values were >0.97 for all matrixes. The Compact Dry TC, at 48 h, offers the advantage of a shorter time to results than ISO 4833 in an easy-to-use format.

본 연구는 환기 방식 및 교반 유무에 따른 축분 퇴비화 시스템 내 대기 및 작업 환경을 평가하기 위해 수행되었다. 측정대상 가스상 물질인 암모니아, 황화수소, 악취농도의 경우 자연환기-미교반시 2.45ppm, 19.96ppb, 15.8, 강제환기-미교반시 7.61ppmm 31.36ppb, 30.2, 자연환기-교반시5.50ppm, 14.69ppb, 46.4, 강제교화기- 교반시 30.12ppm, 39.91ppb, 205.5가 평균적으로 발생되는 것으로 분석되었다. 각 운용조건에 따른 흡입성 분진과 호흡성 분진의 평균 농도는 자연환기-미교반시 368.6<TEX>${\mu}g$</TEX>/<TEX>$m^3$</TEX>,96.0<TEX>${\mu}g$</TEX>/<TEX>$m^3$</TEX>, 강제화기-미교반시 283.9<TEX>${\mu}g$</TEX>/<TEX>$m^3$</TEX>, 119.5<TEX>${\mu}g$</TEX>/<TEX>$m^3$</TEX>, 자연환기-교반시 208.7<TEX>${\mu}g$</TEX>/<TEX>$m^3$</TEX>, 139.8<TEX>${\mu}g$</TEX>/<TEX>$m^3$</TEX>, 강제환기-교반시 209.2<TEX>${\mu}g$</TEX>/<TEX>$m^3$</TEX>, 131.7<TEX>${\mu}g$</TEX>/<TEX>$m^3$</TEX>인 것으로 조사되었다. 총 부유 박테리아와 곰팡이의 경우 자연환기-미교반시 28,673cfu/<TEX>$m^3$</TEX>, 22,507cfu/<TEX>$m^3$</TEX>, 강제환기-미교반시 7,462cfu/<TEX>$m^3$</TEX>,3,229cfu/<TEX>$m^3$</TEX>, 자연환기-교반시 19,592cfu/<TEX>$m^3$</TEX>, 26,376.29cfu/<TEX>$m^3$</TEX>, 강제환기-교반시 18,645cfu/<TEX>$m^3$</TEX>, 24,581cfu/<TEX>$m^3$</TEX>가 평균적으로 발생되는 것으로 분석되었다. 대체로 가스상 물질은 자연환기와 교반을 하지 않는 경우보다 강제환기와 교반을 하는 경우에 더 많이 발생되는 경향을 보였다. 또한 흡입성 분진과 총 부유박테리아의 경우, 자연환기-미교반시에 대체로 더 높게 발생된 반면, 호흡성 분진과 총 부유곰팡이의 경우 강제환기-교반시에 더 많이 발생되는 경향을 보였다. 내부 온도와 상대습도는 입자상 물질과 생물학상 오염물질 발생에 영향을 주는 것으로 분석되었고, 암모니아와 황화수소는 축분 퇴비화시 발생되는 악취 원인물질로 입증되었다. 물리적 요인인 온도와 상대습도는 축분 퇴비화 시스템내에서 주로 입자상 오염물질과 생물학상 오염물질의 발생량에 영향을 미치는 주요인자로 입증되었는데, 시스템 내부 온도와 상대습도가 높으면 이것들의 농도도 높아지는 것으로 분석되었다. Air quality in the livestock waste compost pilot plant at the Colligate Livestock Station was assessed to quantity the emissions of aerial contaminants and evaluate the degree of correlation between them for different operation strategies; with the ventilation types and agitation of compost pile, in this study. The parameters analyzed to reflect the level of air quality in the livestock waste compost pilot plant were the gaseous contaminants; ammonia, hydrogen sulfide, and odor concentration, the particulate contaminants; inhalable dust and respirable dust, and the biological contaminants; total airborne bacteria and fungi. The mean concentrations of ammonia, hydrogen sulfide, and odor concentration in the compost pilot plant without agitation were 2.45ppm, 19.96ppb, and 15.8 when it was naturally ventilated, and 7.61ppm, 31.36ppb, and 30.2 when mechanically ventilated. Those with agitation were 5.50ppm, 14.69ppb, and 46.4 when naturally ventilated, and 30.12ppm, 39.91ppb, and 205.5 when mechanically ventilated. The mean concentrations of inhalable and respirable dust in the compost pilot plant without agitation were 368.6<TEX>${\mu}g$</TEX>/<TEX>$m^3$</TEX> and 96.0<TEX>${\mu}g$</TEX>/<TEX>$m^3$</TEX> with natural ventilation, and 283.9<TEX>${\mu}g$</TEX>/<TEX>$m^3$</TEX> and 119.5<TEX>${\mu}g$</TEX>/<TEX>$m^3$</TEX> with mechanical ventilation. They were also observed with agitation to 208.7<TEX>${\mu}g$</TEX>/<TEX>$m^3$</TEX> and 139.8<TEX>${\mu}g$</TEX>/<TEX>$m^3$</TEX> with natural ventilation, and 209.2<TEX>${\mu}g$</TEX>/<TEX>$m^3$</TEX> and 131.7<TEX>${\mu}g$</TEX>/<TEX>$m^3$</TEX> with mechanical ventilation. Averaged concentrations of total airborne bacteria and fungi in the compost pilot plant without agitation were observed to 28,673cfu/<TEX>$m^3$</TEX> and 22,507cfu/<TEX>$m^3$</TEX> with natural ventilation, and 7,462cfu/<TEX>$m^3$</TEX> and 3,228cfu/<TEX>$m^3$</TEX> with mechanical ventilation. They were also observed with agitation to 19,592cfu/<TEX>$m^3$</TEX> and 26,376cfu/<TEX>$m^3$</TEX> with the natural ventilation, and 18,645cfu/<TEX>$m^3$</TEX> and 24,581cfu/<TEX>$m^3$</TEX> with the mechanical ventilation. It showed that the emission rates of gaseous pollutants, such as ammonia, hydrogen sulfide, and odor concentration, in the compost pilot plant operated with the mechanical ventilation and with the agitation of compost pile were higher than those with the natural ventilation and without the agitation. While the concentrations of inhalable dust and total airborne bacteria in the compost pilot plant with the natural ventilation and with the agitation, the concentrations of respirable dust and total airborne fungi in the compost pilot plant with the mechanical ventilation and agitation were higher than those with the natural ventilation and without the agitation of compost pile. It was statistically proved that indoor temperature and relative humidity affected the release of particulates and biological pollutants, and ammonia and hydrogen sulfide were believed primary malodorous compounds emitted from the compost pilot plant.

Application of gamma irradiation to reduce microbial contamination in herbal cosmetic products

Analysis of Variation in Total Airborne Bacteria Concentration to Assess the Performance of Biological Safety Cabinets in Microbial Laboratories

Fungi are among the most important aeroallergens. The aim of this study was to provide aeromycological baseline information about Zarqa area, Jordan, for the first time. During the entire survey and from 170 settle plate exposures, a total of 735 mould- and 274 yeast colony-forming units (CFU) were collected. mould colonies were assigned to 35 genera and 59 species. The highest abundance was attributed to Cladosporium with a percentage of 29.1% of the total colony count followed by Fusarium 20%, Alternaria 7.7%, Ulocladium 6.5% Penicillium 4.2% and then Aspergillus 3.6%. Cladosporium showed one peak in October while Aspergillus and Penicillium peaked in September. Fusarium peaked in May and August and Alternaria in March and July. However, Ulocladium showed almost the same abundance from March to June and then in September and December. A double peak in total colony count and fungal diversity was found, the first was in March and the second in November–December. Significant differences of total fungal colony counts favouring the 1500 hours collection time over that at 1000 hours were found between November and January while no such significant differences were obtained between February and April. Our results also indicated differences in species composition between the two periods in different months. Spores of the three abundant species, Cladosporium, Fusarium and Alternaria, might favour high release in the 1500 hours period during winter while having a similar incidence during the two periods in the spring months.

BackgroundAccurately detecting the quantity of microorganisms in hospital purified water is of significant importance for early identification of microbial contamination and reducing the occurrence of water-borne hospital infections. The choice of detection method is a prerequisite for ensuring accurate results. Traditional Plate Count Agar (PCA) belongs to a high-nutrient medium, and there may be limitations in terms of accuracy or sensitivity in detecting microorganisms in hospital purified water. On the other hand, Reasoner’s 2A agar (R2A) has characteristics, such as low-nutrient levels, low cultivation temperature, and extended incubation time, providing advantages in promoting the growth of aquatic microorganisms. This study, through comparing the differences in total colony counts between two detection methods, aims to select the method more suitable for the growth of aquatic microorganisms, offering new practical insights for accurately detecting the total count of heterotrophic bacteria in hospital purified water.MethodsThe most commonly used plate count agar (PCA) method, and the R2A agar culture were adopted to detect microorganisms and determine the total number of bacterial colonies in the water for oral diagnosis and treatment water and terminal rinse water for endoscopes in medical institutions. The two water samples were inoculated by pour plate and membrane filtration methods, respectively. Using statistical methods including Spearman and Pearson correlation, Wilcoxon signed-rank sum test, paired-Chi-square test, and linear regression, we analyze the differences and associations in the bacterial counts cultivated through two different methods.ResultsIn 142 specimens of the water, the median and interquartile range of the heterotrophic bacterial colony number under the R2A culture method and under the PCA culture method were 200 (Q1–Q3: 25–18,000) and 6 (Q1–Q3: 0–3700). The total number of heterotrophic bacteria colonies cultured in R2A medium for 7 days was more than that cultured in PCA medium for 2 days (P < 0.05). The linear regression results showed a relatively strong linear correlation between the number of colonies cultured by the R2A method and that cultured by the PCA method (R2 = 0.7264). The number of bacterial species detected on R2A agar medium is greater than that on PCA agar medium.ConclusionThe R2A culture method can better reflect the actual number of heterotrophic bacterial colonies in hospital purified water. After logarithmic transformation, the number of colonies cultured by the two methods showed a linear correlation.

The aim of this paper is to examine the effects of the swiftlet “hotels” to the tourism industry. Tourism is a big business in Malaysia, so is edible swiftlet’s nest . The medicinal values appropriate to the nests by mainly ethnic Chinese result in high demand for them. This creates a booming sector over the horizon, with swiftlet houses dotting the urban and rural landscapes of the country. This study utilized a qualitative approach, with semi-structured in-depth interviews and personal observation employed on swiftlet houses and their owner-operators. Preliminary results suggest bigger swiftlet house operators possessed the notion of expanding their businesses by offering a variety of swiftlet nest-related products and by showcasing the processes to end users. Such action ensures a spillover effect to the tourism industry. On the other hand, findings also suggest that the rise of many of these swiftlet houses in place of conventional types of businesses in urban area has relatively tampered with the authenticity of the built environment.

The production of edible swiftlet nest is a growing industry in Malaysia; where farmers recreate the bird’s habitat in buildings referred to as swiftlet houses. The conditions in these swiftlet houses are however, largely unknown as there seems to be lack of research effort in this newly formed industry. This paper presents the odour and hazardous gas monitoring system utilising wireless sensor network. Several gas sensor readings including humidity, temperature, luminance and rainfall were recorded in a swiftlet house in Arau, Perlis. A single sensor element was found to be insufficient to monitor a specific gas as the odour is a synergy, inhibition and masking between different compounds. Indoor and outdoor humidity and temperature variations were also investigated. The studies have shown that the sensor responses were affected by the odour resulting from different combinations of four different groups of compounds. Minimum threshold level is proposed to alert the breeder so that efforts to reduce the gas levels to a safe and comfortable level can be taken.

The effect of storage on mycoflora profile was monitored bimonthly in 36 corn (Zea mays L.) samples, dividing the same sample into groups dried to 11 and 14% moisture content (1008 analysis). These groups were further subdivided based on the initial total count (moulds and yeasts) up to 104 CFU g-1 (12 samples, range 1.6 × 104 to 9.0 × 104, mean 3.8 × 104 CFU g-1) and up to 105 CFU g-1 (24 samples, range 1.0 × 105 to 5.0 × 105, mean 2.7 × 105 CFU g-1). In the corn group dried to 11%, the fumonisin content was analysed at the initial stage (freshly harvested) and at the end of 12-month storage. Fusarium spp. and Penicillium spp. prevailed at the freshly harvested stage (100%), maintaining this profile throughout 12 months, in corn dried to both 11 and 14%. Cladosporium spp., Aspergillus spp. and Phoma spp. were also detected at lower frequencies during the storage. Fusarium spp. and the total fungal colony count during 12-month storage carried out with samples dried to 11 or 14% moisture content were statistically evaluated using ANOVA for randomized complete block design. The correlation between storage time and Fusarium spp. and total fungal colony count data was analysed by Pearson's correlation test. There was no difference in Fusarium spp. and total counts in the 104 CFU g-1 initial total count group throughout the storage time (p < 0.05). There was a negative correlation between fungal population and storage time (p < 0.05) in the 105 CFU g-1 initial total count group. Fumonisins were detected in all freshly harvested corn, at a mean concentration of 9.9 ± 6.0 µg g-1 (range 0.74-22.6 μg g-1). These values did not change in the 12-month stored corn (mean of 9.9 ± 5.8 μg g-1, range 0.81-23.7 μg g-1). These post harvest data indicated the importance of moisture content at the crop harvesting/predrying stage to control fungal growth and further fumonisin production.

Understanding airborne pollutant levels in a pig-confinement building in seasons with extreme weather (ie, summer and winter) is important for managing air quality, which affects the health of farmers and others in the neighboring environment. The authors evaluated airborne pollutants—total dust, total airborne bacteria, and total airborne gram-negative bacteria—which had higher concentrations in summer than in winter, and concentrations of respirable dust, gaseous pollutants, and total airborne fungi, which were lower in summer than in winter. The authors found significant differences between summer and winter measurements for respirable dust and gaseous pollutants (p < .05). Total dust was positively correlated with bioaerosols and ammonia (p < .05), whereas respirable dust was positively correlated with odor concentration index (p < .05) and hydrogen sulfide (p < .01).

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 &lt; 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.