Mean Concentrations Of Bacteria Research Articles

Enumeration and characterization of airborne microbial communities in an outdoor environment of the city of Taj, India

In the present investigation, the microbiological characteristics of the air in the outdoor environment of the city of Taj, i.e., Agra (India) was assessed by determining the concentration and composition of bacteria and fungi using culture technique. The bacterial isolates having the highest prevalence (100%) throughout the year were selected and identified based on morphological, physiological, and biochemical characteristics. The mean concentration of bacteria in PM10 and PM2.5 was 405.1 CFUm-3 and 364.9 CFUm-3, respectively, while the mean concentration of fungi in PM10 and PM2.5 was 136.5 CFUm-3 and 20.3 CFUm-3, respectively. A new technique of BD (Becton Dickinson)BBL Crystal Mind Auto reader was used. The bacteria were identified as Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Micrococcus luteus, Chromobacterium violaceum, Bacillus cereus, Brevibacillus brevis, Enterobacter aerogenes, Pseudomonas aeruginosa, Acinetobacter beijerenckii. Fifteen fungal isolates were identified comprising of Fusarium, Aspergillus, Epicoccum, Penicillium, Cladosporium, Trichoderma. Alternaria, Mucor, Rhizopus, Geotrichum, Helminthosporium, Absidia, Cephalosporium, Botrytis, and Neurospora. Aspergillus and Penicillium have the maximum percentage occurrence of 98% and 95%, respectively. Botrytis recorded a minimum percentage of 22%, followed by Neurospora 20%. The concentration of bacteria and fungi depend upon the meteorological conditions.

Indoor and Outdoor Concentrations of Bioaerosols and Meteorological Conditions of Selected Salons in Four Areas of Ibadan North Local Government Area

Microorganisms are ubiquitous in the atmosphere but their concentrations are significantly affected by specific environmental factors. Thus, the characterization of bioaerosol levels in both the indoor and outdoor environment have become an important issue due to their adverse health effects. Therefore this study assessed the indoor and outdoor concentrations of bioaerosols and the meteorological conditions in selected salons in four areas of Ibadan North Local Government Area, Oyo State, Nigeria. This comparative cross-sectional study comprised of onsite observations, meteorological measurements viz: temperature and relative humidity (RH) and microbiological assessment (fungi and bacteria load). Building characteristics and sanitary conditions of salons were assessed using a walk-through observational checklist. A TE-10-890 single stage sampler was used for viable bioaerosol sampling and isolates were identified according to standard methods. Data obtained were analysed using descriptive and inferential statistics with SPSS (version 20). Mold growth and damp roof were observed in less than 20% and 40% of salons at the study locations respectively. Mean indoor and outdoor temperature and RH across Agbowo, Mokola, Yemetu and Bashorun were significantly higher than ASHRAE guideline limits. The mean concentrations of bacteria and fungi aerosols were significantly higher indoor than outdoor (p<0.05). Staphylococcus spp, Bacillus spp, Enterobacteria spp and Flavobacterium spp. were the predominant bacteria species isolated while Aspergillus spp, Penicillium spp, Fusarium spp, and Mucor spp. were the most common fungi species detected in the samples. The study showed that both the indoor and outdoor air were contaminated with bacteria and fungi, therefore it is important to control the environmental factors that support microbial growth in order to curtail occurrence of possible adverse effects they may have on health.

Preliminary sanitary analysis of supply and exhaust air of ventilation units working at special rooms

This article is an attempt to estimate concentration of bacteria and fungi in characteristic places in two air handling units. The research was conducted with the units equipped with heat recovery exchanger and recirculation of exhaust air. Additionally, microbiological analysis was done for indoor and fresh air. We performed measurements regarding supply and exhaust air volume. This means that the air velocity inside ventilator chamber was known. The mean concentration of bacteria and fungi was specified for air filters on the supply and exhaust side. The efficiency of air filters was verified by the concertation of bacteria and fungi in fan chamber. This article confirms that bacteria content in supply air is always lower than in exhaust air despite air recirculation. In this work we proved that the position of Petrie plate is essential for bacteria and fungi measurement.

오리 사육장의 공기 중 부유 미생물 및 내독소 노출 농도

The aim of this study was to determine the concentrations of air-borne microorganisms (bacteria, fungi, gram negative bacteria (GNB), endotoxins, and respirable suspended particles (RSPs), and their correlation with environmental parameters (temperature, humidity, and carbon dioxide levels) in duck houses. The mean concentrations of bacteria, fungi, and GNB were very high (> <TEX>$10^6\;CFU/m^3$</TEX>), and endotoxin levels exceeded <TEX>$10^3\;EU/m^3$</TEX>. Among the various work stages, in the task of receiving ducks, bacteria were <TEX>$6.2{\times}10^6;CFU/m^3$</TEX>, and GNB were <TEX>$5.4{\times}10^6\;CFU/m^3$</TEX>, while RSPs levels were <TEX>$397.6\;{\mu}g/m^3$</TEX> and endotoxin levels were <TEX>$47.2{\times}10^3\;EU/m^3$</TEX> in the task of dividing the ducks, and fungi were <TEX>$4.9{\times}10^6\;CFU/m^3$</TEX> in the task of shipping the ducks. The concentrations of RSPs and endotoxins were significantly higher in tasks involving greater movement of ducks in the house, relative to tasks involving little movement of ducks (p<0.05). Further, with progression in growth of the ducks, the concentrations of bacteria, GNB, endotoxins, and RSPs were significantly increased. There was significant correlation between levels of GNB with bacteria (r=0.75) and fungi (r=0.86), endotoxins with RSPs (r=0.75), bacteria with fungi (r=0.39), and carbon dioxide with RSPs (r=0.38), bacteria (r=0.33), and endotoxins (r=0.31). These results suggest considerable respiratory hazard for farmers in these environments.

Assessment of Exposures to Bioaerosols among Poultry Feed Plant Workers

P-125 Introduction: Microorganisms are widespread in the environment and are often a major component of organic dusts because of the nutrients the dusts contain. In the United States, an estimated 700,000 persons, including farmers and their families, employees, and veterinarians, work in livestock and poultry confinement structures. In Turkey there are approximately 420 factories and 15000 workers employs in animal feed industry. The main aim of this study was to measure and evaluate concentration of bacterial bioaerosols and physical measurements in a poultry feed plant workers. Methods: Fifty-three locations (43 cases and 10 controls), airborne bacteria and physical measurements were collected in a poultry feed plant and in the winter season. Sampling cases included collecting bacteria samples and physical measurements in five workplaces of the different plant and controls were from the office of administrative buildings. Sampling at each location was performed once in the morning, once at about noon, and once in the afternoon hrs. Results: The production line had the highest mean concentrations bacteria, temperature and relative humidity. The mean ± SD concentrations of production line and office building collected were 113 ± 4.1 and 40±1.4 cfum-3 for bacteria, respectively. There were found significant differences between mean concentrations of bacteria and physical measurements at production line in comparison with the other locations and office building (p<0.0001). The genera were identified include Staphylococcus epidermis, Streptococcus pneumonia, Escherichia coli and Pseudomonas aeruginosa. Discussion and Conclusions: Values between 100 and 1000 cfum-3 of total bacteria are seen to be acceptable in most indoor environments. Our study shows that bioaerosol concentrations in each of the sites fell within the specified guidelines. In the production line due to mixing, bagging, transportation and lack of local exhaust systems and dilution ventilation, poultry feeds and feed additives are being emitted from the workplace directly into atmospheric and resulting as the most significant exposures to the bioaerosols. The assessment of microorganisms in the air is difficult, because there are very large temporal and spatial variations in bioaerosols that makes representative sampling a difficult task. In our study, particularly when plant products are stored for prolonged periods of time before being processed or consumed may facilitate bacterial growth, because the feasible environmental condition was available. We concluded that season plays an important role when interpreting the results of bacteria sampling. Sampling in winter season would reduce some of the variability of airborne bacterial concentrations and physical measurements. Further studies are necessary to better understand the relationships between environmental characteristics, microbial growth, and health risks.

Recreational Water Quality Control in Mississippi, USA: Bacteriological Assessment in the Pearl River and Ross Barnett Reservoir

We assessed the bacteriological water quality in the Pearl River and Ross Barnett reservoir, a major source of public raw water for the city of Jackson, Mississippi, USA and an important site for recreational activities for local residents and visitors. Infectious diseases caused by pathogenic bacteria are the most common and widespread health risks associated with such water contact activities as bathing, canoeing, and swimming in recreational waters. Water samples collected twice monthly from April 2004 to April 2005 from five different sites of the Pearl river/Ross Barnett reservoir were tested for heterotrophic bacteria, total coliforms, fecal coliforms, and enterococci using membrane filtration technique. Physicochemical parameters (temperature, pH, turbidity, dissolved oxygen, conductivity) were also analyzed using standard methods. The respective mean concentrations of bacteria in water samples were 8.9 x 10(4) +/- 7.4 x 10(4) colony forming units (CFU) 100 mL(-1), 3.0 x 10(3) +/- 4.1 x 10(3) CFU 100 mL(-1), 2.3 x 10(2) +/- 5.4 x 10(2) CFU 100 mL(-1), and 2.3 x 10(2) +/- 4.8 x 10(2) CFU 100 mL(-1) for heterotrophic bacteria, total coliforms, enterococci, and fecal coliforms. The mean values of the physical and chemical parameters were at acceptable levels. Bacterial densities, however, significantly exceeded federal/state guidelines, raising public health concerns. Hence, control strategies should be developed and implemented to prevent further bacterial contamination of Pearl River-Ross Barnett reservoir water resource system.

다중이용시설내 공기중 바이오에어로졸 농도분포 특성에 관한 연구

This study was conducted to evaluate the characterization of airborne bioaerosol in public facilities in Seoul. A total of 17 public facilities were investigated from December, 2002 to February, 2003. As results of the survey, the mean concentrations of bacteria and fungi in indoor air of public facilities were CFU/㎥ by RCS and CFU/㎥ and CFU/㎥ and CFU/㎥, by Six-stage cascade air sampler respectively. The mean concentrations of bacteria in indoor air (by ventilation method) were CFU/㎥ of natural ventilation and CFU/㎥ of mechanical ventilation. The mean concentrations of fungi in indoor air (by ventilation method) were CFU/㎥ of natural ventilation and CFU/㎥ of mechanical ventilation. The mean concentrations of bacteria in indoor air were 449.44 CFU/㎥ for the ground and CFU/㎥ for the underground. The mean concentrations of fungi in indoor air were CFU/㎥ for the ground and CFU/㎥ for the underground.

Assessing waste collectors' exposure to bioaerosols

Published studies on household wastecollectors' exposure to airborne biologicalagents (bioaerosols) do not indicate highexposures to these agents. However, thesestudies did not consider several factors. Theobjective of this study was to characterize theexposure of waste collectors to bioaerosols andto propose solutions to control exposures tothese agents.Personal exposures of waste collectors tobioaerosols (total bacteria, endotoxins andmolds) were measured for seven types ofcollection during the summer, which representsthe worst conditions. The effect of truckcleaning was also evaluated. Meanconcentrations of bacteria were all in theorder of 103–104 CFU/m3 of air. Theintervention threshold was exceeded forendotoxins during the collection of compostonce every two weeks in the country. Meanconcentrations varied from 8.5 to 100 endotoxinunits per cubic meter of air (EU/m3). Measuredmean concentrations of molds were between 8,300and 98,170 CFU/m3 of air. Also, the cleaningof an empty garbage truck does not improve thequality of the air. On the other hand, a dirtytruck is not a major source of bioaerosols.The sources of these bioaerosols are leachate,particularly if the waste in the truck is oforganic origin, as well as the garbage pailsthat contain this waste. Unnecessary exposuresto these sources should therefore be avoided. For bioaerosols, stringent personal hygienemeasures remain one of the best means ofprevention.

Physicochemical and bacteriological assessment of water quality at the Ross Barnett reservoir in central Mississippi.

The Ross Barnett Reservoir serves as a source of water supply for the city of Jackson, Mississippi, U.S.A. and is an important site for recreational activities for many residents of Mississippi counties. A broad spectrum of illness is associated with water-contact activities like bathing and swimming in recreational waters. In the present research, we assessed the bacteriological quality of water in the Ross Barnett Reservoir and compared the levels of bacteria with the recommended criteria for public health protection. From June 12, 1999 to October 2, 1999, we collected water samples weekly from two different sites in the reservoir and tested them for the following bacteriological parameters: heterotrophic plate counts, total coliforms, fecal coliforms, and fecal streptococci. The samples were also tested for basic physical and chemical characteristics of water. The results of the study indicate that the respective mean concentrations of bacteria (colony forming units per 100 mL of water) in water samples collected from the reservoir were 5.6 x 10(6)+/-1.5 x 10(6) (heterotrophic plate counts), 4.5 x 10(4) +/- 5.3 x 10(4) (total coliforms), 5.0 x 10(2) +/- 1.6 x 10(2) (fecal coliforms), and 9.1x10(1)+/-7.3x10(1) (fecal streptococci). The values of all physical and chemical parameters were at acceptable levels. The bacterial densities, however, often exceeded federal/state guidelines by several orders of magnitude, raising considerable public health concerns. Steps should therefore be taken to develop and implement strategies to improve the water quality and to reduce or eliminate the potential health risks associated with water-contact activities in the Ross Barnett Reservoir.

Quantitative bacteriology of acute dento-alveolar abscesses

A qualitative and quantitative bacteriological study was performed on pus specimens obtained by needle aspiration of 50 acute dento-alveolar abscesses. Most samples contained a mixture of species (average 3.3); 20 (40%) of the abscesses contained anaerobes alone, 3 (6%) contained facultative anaerobes only and the remaining 27 (54%) contained mixtures of both types of bacteria, with anaerobes predominating. In total, 166 bacterial strains were isolated, 75% of which were strictly anaerobic; the most common species were Peptococcus spp, Bacteroides oralis and B. melaninogenicus. Among facultative anaerobes, Streptococcus milleri was particularly common. The mean concentration of bacteria in each abscess was 10(6.9 +/- 0.2). The mean concentration of anaerobic bacteria was 10(6.2 +/- 0.1) and of facultatively anaerobic bacteria 10(5.7 +/- 0.2).