High Concentrations Of Bacteria Research Articles

Characteristics and health impacts of bioaerosols in animal barns: A comprehensive study

Bioaerosols produced during animal production have potential adverse effects on the health of workers and animals. Our objective was to investigate characteristics, antibiotic-resistance genes (ARGs), and health risks of bioaerosols in various animal barns. Poultry and swine barns had high concentrations of airborne bacteria (11156 and 10917 CFU/m3, respectively). Acinetobacter, Clostridium sensu stricto, Corynebacterium, Pseudomonas, Psychrobacter, Streptococcus, and Staphylococcus were dominant pathogenic bacteria in animal barns, with Firmicutes being the most abundant bacterial phylum. Based on linear discriminant analysis effect size (LEfSe), there were more discriminative biomarkers in cattle barns than in poultry or swine barns, although the latter had the highest abundance of bacterial pathogens and high abundances of ARGs (including tetM, tetO, tetQ, tetW sul1, sul2, ermA, ermB) and intI1). Based on network analyses, there were higher co-occurrence patterns between bacteria and ARGs in bioaerosol from swine barns. Furthermore, in these barns, relative abundance of bacteria in bioaerosol samples was greatly affected by environmental factors, mainly temperature, relative humidity, and concentrations of CO2, NH3, and PM2.5. This study provided novel data regarding airborne bio-contaminants in animal enclosures and an impetus to improve management to reduce potential health impacts on humans and animals.

Fixation of high concentration CO2 using Chlorella – Bacteria symbiosis system

The mutualistic interaction between microalgae and bacteria provides a new strategy for improving carbon fixation by microalgae. In this study, Chlorella was co-cultured with natural flora at 15 % (v/v) CO2 concentration for 120 d. Three Chlorella symbiotic bacteria strains were identified and were co-cultured with Chlorella vulgaris HL02 (C. vulgaris HL02) to fix high concentrations of CO2. The results showed that the symbiotic bacteria significantly enhanced the fixation of 15 % CO2 by Chlorella, with C. vulgaris HL02 + Aeromonas GS-HL01 having the highest carbon fixation efficiency, which was 22.31 % higher than that of the sterile control, followed by C. vulgaris HL02 + Bacillus GS-F03, and C. vulgaris HL02 + Microbacterium GS-H02 (which was also 16.36 % higher than the sterile control). The composition of harvested Chlorella was not altered significantly following co-culturing with bacteria. Scanning electron microscopy and Excitation–emission matrix spectra analyses showed that at high concentrations of CO2, Microalgae and bacteria promote mutual growth and CO2 fixation mainly through extracellular secretion of organic matter. Our results provided a new strategy to improve the efficiency of microalgae in fixing high concentration of CO2.

Effect of Sulphate-Reducing Bacteria Activity on the Performance of Thermally Sprayed Aluminium and Polyurethane Coatings

In the present work, we studied whether the exposure of synthetic seawater with anaerobic sulphate-reducing bacteria (SRB) on some steel samples generates a bacterial biofilm in their surfaces. Bare steel belonging to a mooring chain as well as two coating systems applied on the steel surface were studied: polyurethane (PU) and thermally sprayed aluminium (TSA) with and without an epoxy-based sealant. After 30 days of immersion in SRB-inoculated synthetic seawater, a bacterial count was attained, and the samples were observed using scanning electron microscopy (SEM) and locally analysed using X-ray scattered energy spectroscopy (EDS). A biofilm developed on every tested surface (continuous or in the form of pustules), with evidence of metabolic activity of the SRB. Finally, a mechanism of degradation for TSA in the presence of SRB is proposed for environments with a high concentration of bacteria.

Contamination of Fish Feed with Pathogenic Organisms: Implications on Fish Diseases in Aquaculture Systems

Tracing contamination to its ultimate source is considered difficult as multiple factors affect stable microbial community in culture water. Feed, covering over 60 percent of production cost although less considered, could represent a significant source of fish diseases, the major constraint in aquaculture production. The present study based on the sensitivity of quantitative Polymerase Chain Reaction, indicated low to high concentrations of bacteria and fungi in fish-feed from various aquaculture farms in Ghana. Prevalence rate of bacteria isolated from the gut of fish (26.09%) were similar to that from diseased portions (26.89%). Although mode of transmission of most infections are largely through the water in which the fish are submerged, Staphylococcus aureus was not isolated from the culture water samples but occurred with the highest prevalence (60%) in fish-feed, thus confirming contamination of fish-feed as a significant pathway for entry of pathogens. Advancements towards the safety of fish should include the surveillance of fish-feed for microbial quality, and incorporation into human foodborne disease surveillance systems to ensure holistic effectiveness.

Characterization of four digestates from different types of substrates used in biogas production in Northern Peru

Background Biol is one of the best-known digestates, which occurs during anaerobic digestion in biodigesters to generate biogas, using animal manure and vegetable waste. This digestate type is used in organic agriculture due to its easy application, contributing simultaneously to the circular economy and food security. Methods The objective of this study was to characterize four types of biol, generated in four anaerobic biodigesters for biogas production implemented in northern Peru fed with manure: i) pig manure; ii) cattle manure; iii) horse manure; iv) cattle manure with coffee processing water. All the biodigesters implemented had the same design but worked under different environmental conditions. Descriptive and multivalent statistics were applied to the data obtained for the parameters evaluated. Results The biols obtained had different nutritional compositions, depending on the type of substrate used. The biol from pig manure was characterized by high concentrations of bacteria, the one from cattle manure had low concentrations of nutrients in general, the one from horse manure was rich in salts, and the one from cattle manure with coffee processing water was rich in organic matter. Conclusions These results showed that all the biols obtained can be used for organic agriculture. However, their selection will depend on the nutritional requirements of the type of crop and soil where the biols are to be applied.

Influence of phosphate on bacterial release from activated carbon point-of-use filters and on biofilm characteristics

Point-of-use (POU) filters certified to remove lead are often composed of activated carbon and have been shown to release high concentrations of bacteria, including opportunistic pathogens. In this study, we examine the impacts of the common corrosion inhibitor phosphate on biofilm characteristics and the relationship between biofilm structure and bacterial release from POU filters. This knowledge is essential for understanding how best to use the filters and where these filters fit in a system where other lead contamination prevention measures may be in place. We measured the bacterial release from activated carbon POU filters fed with groundwater - a common source of drinking water - with and without phosphate. We used optical coherence tomography (OCT) to quantitatively characterize biofilm growing on activated carbon filter material in which the biofilms were fed groundwater with and without phosphate. Phosphate filters released significantly less (57–87 %) bacteria than groundwater filters, and phosphate biofilms (median thickness: 82–331 μm) grew to be significantly thicker than groundwater biofilms (median thickness: 122–221 μm). The phosphate biofilm roughness ranged from 97 to 142 % of the groundwater biofilm roughness and was significantly greater in most weeks. Phosphate biofilms also had fewer pores per biofilm volume and shorter channels connecting those pores.

Indoor air quality improvement with filtration and UV-C on mitigation of particulate matter and airborne bacteria: Monitoring and modeling

Indoor air, especially with suspended particulate matter (PM), can be a carrier of airborne infectious pathogens. Without sufficient ventilation, airborne infectious diseases can be transmitted from one person to another. Indoor air quality (IAQ) significantly impacts people's daily lives as people spend 90% of their time indoors. An industrial-grade air cleaner prototype (filtration + ultraviolet light) was previously upgraded to clean indoor air to improve IAQ on two metrics: particulate matter (PM) and viable airborne bacteria. Previous experiments were conducted to test its removal efficiency on PM and airborne bacteria between the inlet and treated air. However, the longer-term improvement on IAQ would be more informative. Therefore, this research focused on quantifying longer-term improvement in a testing environment (poultry facility) loaded with high and variable PM and airborne bacteria concentrations. A 25-day experiment was conducted to treat indoor air using an air cleaner prototype with intermittent ON and OFF days in which PM and viable airborne bacteria were measured to quantify the treatment effect. The results showed an average of 55% reduction of total suspended particulate (TSP) concentration between OFF days (110 μg/m3) and ON days (49 μg/m3). An average of 47% reduction of total airborne viable bacteria concentrations was achieved between OFF days (∼3200 CFU/m3) and ON days (∼2000 CFU/m3). A cross-validation (CV) model was established to predict PM concentrations with five input variables, including the status of the air cleaner, time (h), ambient temperature, indoor relative humidity, and day of the week to help simulate the air-cleaning effect of this prototype. The model can approximately predict the air quality trend, and future improvements may be made to improve its accuracy.

Association Between Air Microbiological Exposure With Sick Building Syndrome (SBS) among College Dormitory Students in Public University

Introduction: Microbiological pollutants in indoor air can lead to sick building syndrome (SBS). A conducive academic environment in university dormitories requires healthy indoor air quality to enhance student performance. This study aimed to determine the association between indoor air microbiological exposure and SBS among college dormitory students at a public university. Methods: A cross-sectional study was conducted among 112 male and female college dormitory students who stayed in the public university dormitory for more than three months. Respondents were given a self-administered questionnaire-based NIOSH Indoor Environmental Quality Survey. 14 houses were selected for the measurement of indoor air quality which included PM2.5, PM10, relative humidity (%), temperature (°C), air velocity (m/s), indoor bacterial concentration (cfu/m3), and indoor mould concentration (cfu/m3). Results: Higher percentages of SBS symptoms were reported among female (94.6%) college dormitory students compared to male (82.1%). A significant difference in itching symptom on the arms and forearms was found among individuals of different genders (p<0.05). Indoor air parameters such as temperature (OR = 2.56, 95% CI = 2.66-9.87), relative humidity (OR = 1.77, 95% CI = 1.54 – 5.79), indoor bacteria concentration (OR=2.28, 95% CI = 2.48 – 10.93), and indoor mould concentration (OR=2.59, 95% CI = 1.75 – 8.98) were significantly associated with the recent SBS symptoms. Multiple logistic regression showed that the most significant predictor of SBS was indoor mould concentration. Conclusion: Exposure to high concentrations of indoor bacteria and mould, high temperatures, and high relative humidity influenced the prevalence of SBS among college dormitory students. Further assessment and preventive action need to be taken to reduce the exposure of indoor air microbiological to the students.

Longitudinal examination of urine pH, specific gravity, protein, culture, and antimicrobial resistance profiles in healthy dogs.

Urine is routinely evaluated in dogs to assess health. Reference ranges for many urine properties are well established, but the scope of variation in these properties over time within healthy dogs is not well characterized. Longitudinally characterize urine properties in healthy dogs over 3 months. Fourteen healthy client-owned dogs. In this prospective study, dogs were evaluated for health; then, mid-stream free-catch urine was collected from each dog at 12 timepoints over 3 months. Urine pH, urine specific gravity (USG), protein, cultures, and antimicrobial resistance profiles were assessed at each timepoint. Urine pH varied within and between dogs over time (Friedman's test: within P = .03; between P < .005). However, USG, protein, and bacterial diversity of urine were consistent within dogs over time, and only varied between dogs (Kruskal-Wallis: between all P < .005). Antimicrobial resistant isolates were identified in 12 out of 14 dogs with 34 of 48 of the isolates demonstrating resistance to amoxicillin. Urine pH should be assessed at multiple timepoints via pH meter before making clinical decisions. Mid-stream free-catch urine with high concentrations of bacteria (>105 CFU/mL) should not be considered the only indicator of urinary tract infection. Bacterial isolatesfrom dogs in this study had widespread resistance to amoxicillin/oxacillin underscoring the need for antimicrobial stewardship.

Role of suspended solids on the co-precipitation of pathogenic indicators and antibiotic resistance genes with struvite from digested swine wastewater

Struvite recovered from wastewater contains high concentration of fecal indicator bacteria (FIB), porcine adenoviruses (PAdV) and antibiotic resistance genes (ARGs), becoming potential resources of these microbial hazards. Understanding the precipitation behavior of pathogenic indicators and ARGs with suspended solids (SS) will provide the possible strategy for the control of co-precipitation. In this study, SS was divided into high-density SS (separated by centrifugation) and low-density SS (further separated by filtration), and the role of SS on the co-precipitation of FIB, PAdV and ARGs was investigated. The distribution analysis showed that 35.5–73.0% FIB, 79.6% PAdV and 64.5–94.8% ARGs existed in high-density SS, while the corresponding values were 26.9–64.4%, 11.7% and 3.5–24.3% in low-density SS. During struvite generation, 82.7−96.9% FIB, 75.5% PAdV and 56.3–86.5% ARGs were co-precipitated into struvite. High-density SS contributed 20.7−68.5% FIB, 63.9% PAdV and 38.7–87.2% ARGs co-precipitation, and the corresponding contribution of low-density SS was 31.4−79.2%, 3.9% and 6.2–54.7%. Moreover, the precipitated SS in struvite obviously decreased inactivation efficiency of FIB and ARGs in drying process. These results provide a potential way to control the co-precipitation and inactivation of FIB, PAdV and ARGs in struvite through removing high-density SS prior to struvite recovery.

An esterase activity-based biosensor for rapid and sensitive detection of viable Escherichia coli O157:H7 in milk

Escherichia coli O157:H7 is harmful to humans by producing toxins that cause thrombotic thrombocytopenic purpura and haemolytic uraemic syndrome. Real-time recombinase-aided amplification (rRAA) can generate real-time fluorescence signals to achieve sensitive detection of pathogens within 20 min but cannot distinguish dead bacteria from viable bacteria, leading to false-positive results. Thiazole orange monoazide (TOMA) is an activity-labile nucleic acid-modifying compound, permeating into bacterial cells and, in dead cells, covalently linking to genomic DNA to suppress DNA amplification. In viable cells, however, TOMA is cleaved by active esterase and so inhibition of DNA amplification would not occur. A rRAA assay integrated with TOMA was successfully developed potentially enabling rapid and sensitive identification of viable E. coli O157:H7 in milk. The limit of detection was less than 10 cfu mL−1 in both pure culture and skimmed milk. Moreover, this assay could resist interference from non-target bacteria and high concentrations of dead bacteria.

Human wastewater tracking in tropical Hawaiian island streams using qualitative and quantitative assessments of combined fecal indicating bacteria and sucralose, an organic micropollutant of emerging concern

Prevalence of cesspools on tropical islands suggests that high concentrations of enteric bacteria in streams and coastal waters are an indicator of groundwater contamination by human wastewater. But enterococci bacteria may also be from homeothermic animals common to these watersheds or bacteria living in sediments. Sucralose, a manufactured chemical not destroyed in passage through the human gut, cesspools, septic systems, or wastewater treatment facilities, was used to test for the presence of human wastewater in streams on the island of Kauai, Hawaii. Effluent from six municipal wastewater treatment plants showed an average concentration of 39,167 ng/L of sucralose, roughly back-calculated to 9 ng/L per person, enough to present itself in cesspool effluent contaminated waters. Of 24 streams tested, 79% were positive for sucralose at least once in four sets of sampling. All streams tested positive for enterococci bacteria above established standards. Serial testing of the pair of indicators in the same location over time and applying the Multiplication Rule to the independent samples provide a probabilistic certainty level that the water is chronically polluted by human waste. When repeatedly paired with tests for enterococci, sucralose testing is a cost-effective means for assessing human health risk and for developing proper waste management programs that has been underutilized in under-developed tropical and island settings.

Efficacy of UV and UV-LEDs Irradiation Models for Microbial Inactivation Applicable to Automated Sterile Drug Compounding

LEDs development has attracted attention over conventional mercury lamps for the tiny size, high efficiency, long lifetime, low operating temperature. The antimicrobial effectiveness of traditional UV-lamps radiation (wavelength of 254 nm) compared to UV-C LEDs (LED1 wavelength range 275–286 nm and LED2 range 260–270 nm) was carried out, for possible applications to automated sterile drug compounding. The UV lamp and the tested UV-LED devices remarkably reduced microbial load, following a time-dose response, but the best performance was evidenced by LED1, which guaranteed the complete inactivation of high concentrations of bacteria, yeasts, and spores at doses between 200 and 2000 J/m2.

Microfluidic isothermal amplification strategy coupled with improved propidium monoazide (PMAxx) for rapid detection of six viable foodborne pathogens

Based on the combination of the centrifugal microfluidic chip, programable loop-mediated isothermal amplification (pLAMP), and improved propidium monoazide (PMAxx), a new method called PMAxx-mpLAMP was developed for the quantitative determination of six viable foodborne pathogens in real food samples. Specific target genes and primers were designed and verified, and the PMAxx conditions were optimized. Treatment with PMAxx before pLAMP eliminated false-positive outcomes from dead bacteria and identified viable target bacteria with good specificity and sensitivity. The PMAxx-mpLAMP strategy could detect approximately 102 ∼ 103 CFU/mL pathogens without any pre-enrichment and 101 CFU/mL after a short period of enrichment. In addition, the PMAxx-mpLAMP strategy was performed in the presence of a high concentration of dead bacteria and non-target bacteria. Therefore, the established PMAxx-mpLAMP strategy in this study has potential value for the rapid and sensitive detection of foodborne pathogens.

Bactericidal activity of anti-ABO antibodies in isolated colonies from Escherichia coli

The interaction between ABO antigens and microorganisms, including those present in the microbiota, has been studied about the possible action of antigens and ABO antibodies in susceptibility to infectious diseases. This research aimed to determine the minimum titer of the Escherichia coli bacteria capable of undergoing in vitro bactericidal action of human anti-ABO antibodies. The selection of blood samples was performed through a questionnaire, blood phenotyping (one volunteer of each ABO phenotype), and the titration of ABO antibodies. A bacterial suspension (inoculum) was prepared and added to the serum of the volunteers, followed by inoculation in Mueller Hinton Agar. After 24 hours, the results were read and interpreted with duplicate analysis. There was no significant difference in the bactericidal test between tests 1 and 2 in blood groups A, B, AB, O, and Positive Control. There was a significant difference in pure human serum when Group A x Positive Control was analyzed, Group B x Positive Control, Group AB x Positive Control, and Group O x Positive Control. There was no significant difference in the other dilutions. It is concluded that anti-ABO antibodies have a bactericidal effect when there is a high concentration of bacteria in the environment.

Widespread human waste pollution in surface waters observed throughout the urbanized, coastal communities of Lee County, Florida, USA

The coastal communities of Lee County, Florida, USA have grown rapidly since the 1970s. In this county, drainage ditches, canals, creeks, and the Caloosahatchee River Estuary often have high concentrations of nutrients and bacteria limiting their designated uses. Septic systems have previously been identified as a major pollution source in some areas of Lee County; therefore, this study sought to identify the extent of this issue throughout the county. To accomplish this, surface water samples were collected at 25 ditch, creek, or canal sites suspected of human waste contamination from septic systems in various drainage basins throughout Lee County during January 2020–January 2021. Water samples were analyzed for nutrients, dual stable nitrate isotopes (δ15N-NO3−, δ18O-NO3−), fecal indicator bacteria (enterococci, Escherichia coli), a molecular tracer of human waste (HF183), and chemical tracers of human waste (the artificial sweetener sucralose, pharmaceuticals). Particulate organic matter (POM) and macrophytes were also collected and analyzed for stable carbon (δ13C) and nitrogen (δ15N) isotopes, as well as elemental composition (C:N:P). To broaden the assessment of stable isotope values and C:N:P, archived macrophyte samples from 2019 were also included in analyses. Ammonium concentrations were high (> 4.3 μM) in 55 % of samples. Fecal bacteria were high in 66 % of samples. HF183 was detected in 50 % of samples and positively correlated with enterococci (r = 0.32). Sucralose concentrations were high (> 380 ng/L) in 54 % of samples, while carbamazepine was detected in 40 % of samples. Human waste N sources were indicated by δ15N > 3.00 ‰ at 44 % of sites by δ15N-NO3−, 68 % of sites by POM, and at 100 % of sites where macrophyte samples were collected. This large-scale study provides evidence of widespread human waste pollution throughout Lee County and can help guide infrastructure improvements to promote sustainable development. These findings should be applicable to urbanized regions globally that are experiencing declines in water quality and harmful algal blooms due to development with inadequate infrastructure.

Predicting Fecal Indicator Bacteria Using Spatial Stream Network Models in A Mixed-Land-Use Suburban Watershed in New Jersey, USA

Good water quality safeguards public health and provides economic benefits through recreational opportunities for people in urban and suburban environments. However, expanding impervious areas and poorly managed sanitary infrastructures result in elevated concentrations of fecal indicator bacteria and waterborne pathogens in adjacent waterways and increased waterborne illness risk. Watershed characteristics, such as urban land, are often associated with impaired microbial water quality. Within the proximity of the New York-New Jersey-Pennsylvania metropolitan area, the Musconetcong River has been listed in the Clean Water Act's 303 (d) List of Water Quality-Limited Waters due to high concentrations of fecal indicator bacteria (FIB). In this study, we aimed to apply spatial stream network (SSN) models to associate key land use variables with E. coli as an FIB in the suburban mixed-land-use Musconetcong River watershed in the northwestern New Jersey. The SSN models explicitly account for spatial autocorrelation in stream networks and have been widely utilized to identify watershed attributes linked to deteriorated water quality indicators. Surface water samples were collected from the five mainstem and six tributary sites along the middle section of the Musconetcong River from May to October 2018. The log10 geometric means of E. coli concentrations for all sampling dates and during storm events were derived as response variables for the SSN modeling, respectively. A nonspatial model based on an ordinary least square regression and two spatial models based on Euclidean and stream distance were constructed to incorporate four upstream watershed attributes as explanatory variables, including urban, pasture, forest, and wetland. The results indicate that upstream urban land was positively and significantly associated with the log10 geometric mean concentrations of E. coli for all sampling cases and during storm events, respectively (p < 0.05). Prediction of E. coli concentrations by SSN models identified potential hot spots prone to water quality deterioration. The results emphasize that anthropogenic sources were the main threats to microbial water quality in the suburban Musconetcong River watershed. The SSN modeling approaches from this study can serve as a novel microbial water quality modeling framework for other watersheds to identify key land use stressors to guide future urban and suburban water quality restoration directions in the USA and beyond.

Evaluation of physicochemical and microbiological parameters, and their correlation in Himalayan Spring Water Systems: A case study of District Kulgam of Kashmir Valley, India, Western Himalaya.

Total coliforms, E. coli, and fecal streptococci are the important indicators linked to the human health. This study investigated presence of these indicator bacteria in the Himalayan springs at various locations in the district Kulgam of Kashmir valley. A total of 30 spring water samples were collected from rural, urban, and forest areas during post-melting season 2021 and pre-melting season 2022. The springs in the area originate from the alluvium deposit, Karewa, and hard rock formations. The physicochemical parameters were found within the acceptable limits. However, nitrate and phosphate were found above the permissible limit at few sites, thus indicating the presence of anthropogenic activities in the area. Majority of the samples during both the seasons were found highly loaded with total coliforms with maximum limit of greater than 180 MPN/100ml. E. coli and fecal streptococci were found in the range of less than 1 to more than 180 MPN/100ml. The results of Pearson correlation of physicochemical parameters with indicator bacteria showed that chemical oxygen demand, rainfall, spring discharge, nitrate, and phosphate are the main factors affecting the concentration of indicator bacteria in the spring water at each site. Principal component analysis showed the most influencing factors of water quality in most of the spring sites are total coliforms, E. coli, fecal streptococci, rainfall, discharge, and chemical oxygen demand. The results of this study showed that the spring water is unfit for drinking purpose because of high concentration of fecal indicator bacteria.

The Risk of Exposure to Infectious Bacterial Bioaerosols in Different Hospital Wards: A Case Study

Background: Biological aerosol particles smaller than 10 microns in diameter are among the health concerns in hospitals since they remain in the air for a long time and are infectious and easily transported. We aimed to investigate the concentration of Escherichia coli and Staphylococcus aureus bioaerosols and evaluate their risk in the indoor environment of different wards of Khatam al-Anbia hospital, Jask, Iran, in 2020. Methods: This descriptive-analytical study was performed by collecting and analyzing 50 samples from seven different hospital wards. The active sampling of bioaerosols was performed according to the standard method of the National Organization for Occupational Health and Safety and by a pump with a flow rate of 28.3 L/min for 10 minutes. Blood agar and eosin methylene blue were used to detect bacteria. Then, the Monte Carlo simulation technique was used to assess the microbial risk. Results: The concentration of S. aureus in different wards of the hospital was 4.81 to 18.11 CFU/m3 . The lowest and highest concentrations of S. aureus were in the operating room and general emergency wards, respectively, while the highest and lowest concentrations of E. coli were in the inpatient wards (0 CFU/m3 ) and infectious emergency ward (21.22 CFU/m3 ), respectively. The highest and lowest daily risk of S. aureus was observed in the neonatal and general emergency wards (8.03×10-4 and 3.02×10-4), respectively. Moreover, the lowest and highest daily risk of E. coli was found in the neonatal and male inpatient wards (zero and 7.21×10-3), respectively. Conclusion: In some hospital wards, the concentration and infection risk of E. coli and S. aureus were found to be higher than the acceptable value. Since high concentrations of airborne bacteria can play an important role in producing nosocomial infections in patients and staff, it is necessary for hospital officials to take corrective measures in equipment control, use proper ventilation systems in the wards, and closely monitor the disinfection process.

Airborne Microbial Quality Assessment in the Educational Buildings during the COVID-19 Pandemic

Rooms with pollutants have a poor impact of 2-5 times greater than outdoors. The lecture hall had the potential to experience a decrease in air quality. This study was conducted to assess microbiological air quality in the general lecture building I Institut Teknologi Sumatra, Lampung, Indonesia, during the COVID-19 pandemic and its relationship with environmental conditions. This study was conducted using a settling sampling technique to count the number of bacteria and fungi in the air. Samples were collected twice daily for five working days. The results showed that the highest concentrations of bacteria and fungi were found at the wifi corner location, at 36.7–1237.2 CFU/m3 and 225.4–1431.2 CFU/m3, respectively. The highest average concentrations of bacteria and fungi at the wifi corner location were found in the afternoon at 479.1 ± 438.1 CFU/m3 and 800 ± 548.4 CFU/m3, respectively. The three locations did not meet the standards of room suitability for humans with immunodeficiencies based on the ACGIH. The location of the wifi corner did not meet the standards of the Minister of Manpower of the Republic of Indonesia No. 5 of 2018 and the WHO regarding microbial standards in the room. The highest value of the Global Microbial Contamination Index (GIMC/m3) was found in the wifi corner (G4: ≥2000 – ≤4000), which is closely related to population density and ventilation. Environmental factors influence the density of bacteria and fungi at the sampling sites. The relative humidity strongly influenced the concentration of fungi. In addition to relative humidity, bacterial density is also affected by light intensity and the number of people. This indicates that despite restrictions on activities during the COVID-19 pandemic, the room at GKU 1 did not meet the eligibility requirements for students with immune disorders. Doi: 10.28991/CEJ-2023-09-01-09 Full Text: PDF