scholarly journals A comparison of several media types and basic techniques used to assess outdoor airborne fungi in Melbourne, Australia

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0238901
Author(s):  
Wesley D. Black
Keyword(s):  
Indoor Air ◽  
Airborne Fungi ◽  
Malt Extract ◽  
Standard Medium ◽  
Mineral Supplements ◽  
Enhancing Factor ◽  
Colony Forming Units ◽  
Significant Difference ◽  
Agar Media ◽  
Media Types

Despite the recent increase in interest in indoor air quality regarding mould, there is no universally accepted standard media for the detection of airborne fungi, nor verification of many commonly used techniques. Commonly used media including malt-extract agar (MEA), Sabouraud dextrose agar (Sab), potato dextrose agar (PDA) with and without antibiotics chloramphenicol & gentamycin (CG) were compared for their suitability in detecting a range of airborne fungi by collecting 150 L outdoor air on a number of different days and seasons via an Anderson 400-hole sampler in suburban Melbourne, Australia. There was relatively little variation in mean numbers of colony forming units (CFU) and types of fungi recovered between MEA, PDA, Sab media groups relative to variation within each group. There was a significant difference between Sab, Dichloran-18% glycerol (DG18) and V8® Original juice agar media, however. Antibiotics reliably prevented the growth of bacteria that typically interfered with the growth and appearance of fungal colonies. There was no significant evidence for a growth enhancing factor from potato, mineral supplements or various vegetable juices. Differing glucose concentrations had modest effects, showing a vague ideal at 2%-4% with peptone. Sanitisation of the aluminium Andersen 400-hole sampler top-plate by flame is possible, but not strictly required nor advisable. The use of SabCG as a standard medium was generally supported.

scholarly journals A comparison of several media types and basic techniques used to assess outdoor airborne fungi in Melbourne, Australia

2020 ◽  
Author(s):  
Wesley D Black
Keyword(s):  
Indoor Air ◽  
Airborne Fungi ◽  
Malt Extract ◽  
Standard Medium ◽  
Mineral Supplements ◽  
Enhancing Factor ◽  
Colony Forming Units ◽  
Significant Difference ◽  
Agar Media ◽  
Media Types

AbstractDespite the recent increase in interest in indoor air quality regarding mould, there is no single widely accepted standard media for the detection of airborne fungi, nor verification of many commonly used techniques. Commonly used media including malt-extract agar (MEA), Sabouraud dextrose agar (Sab, SDA, SabCG), potato dextrose agar (PDA) with and without antibiotics chloramphenicol & gentamycin (CG) were compared for their suitability in detecting a range of common airborne fungi by collecting 150 L outdoor air on a number of different days and seasons via an Anderson 400-hole sampler in suburban Melbourne, Australia. There was relatively little variation in mean numbers of colony forming units (CFU) and types of fungi recovered between MEA, PDA, SabCG media groups relative to variation within each group. There was a significant difference between SabCG, Dichloran-18% glycerol (DG18) and V8® Original juice agar media, however. Antibiotics reliably prevented the growth of bacteria that typically interfered with the growth and appearance of fungal colonies. There was no significant evidence for a growth enhancing factor from potato, mineral supplements or various vegetable juices. Differing glucose concentrations had modest effects, showing a vague ideal at 2%-4% with peptone. Sanitisation/sterilisation of the aluminium Andersen 400-hole sampler top-plate by flame is possible, but not strictly required nor advisable. The use of SabCG as a standard medium was generally supported.

scholarly journals Loading Rates of Dust and Bioburden in Dwellings in an Inland City of Southern Europe

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 378
Author(s):  
Carla Viegas ◽  
Marta Dias ◽  
Beatriz Almeida ◽  
Estela Vicente ◽  
Carla Candeias ◽  
...  
Keyword(s):  
Indoor Air ◽  
Microbial Contamination ◽  
Fungal Species ◽  
Malt Extract ◽  
Gram Negative Bacteria ◽  
Fungal Contamination ◽  
Loading Rates ◽  
Colony Forming Units ◽  
Dust Loading ◽  
Total Bacteria

Sampling campaigns indoors have shown that occupants exposed to contaminated air generally exhibit diverse health outcomes. This study intends to assess the deposition rates of total settleable dust and bioburden in the indoor air of dwellings onto quartz fiber filters and electrostatic dust collectors (EDCs), respectively. EDC extracts were inoculated onto malt extract agar (MEA) and dichloran glycerol (DG18) agar-based media used for fungal contamination characterization, while tryptic soy agar (TSA) was applied for total bacteria assessment, and violet red bile agar (VRBA) for Gram-negative bacteria. Azole-resistance screening and molecular detection by qPCR was also performed. Dust loading rates ranged from 0.111 to 3.52, averaging 0.675 μg cm−2 day−1. Bacterial counts ranged from undetectable to 16.3 colony-forming units (CFU) m−2 day−1 and to 2.95 CFU m−2 day−1 in TSA and VRBA, respectively. Fungal contamination ranged from 1.97 to 35.4 CFU m−2 day−1 in MEA, and from undetectable to 48.8 CFU m−2 day−1 in DG18. Penicillium sp. presented the highest prevalence in MEA media (36.2%) and Cladosporium sp. in DG18 (39.2%). It was possible to observe: (a) settleable dust loadings and fungal contamination higher in dwellings with pets; (b) fungal species considered indicators of harmful fungal contamination; (c) Aspergillus section Candidi identified in supplemented media with voriconazole and posaconazole; (d) specific housing typologies and (e) specific housing characteristics influencing the microbial contamination.

scholarly journals Airborne Fungi in Prison Indoor Environments of Nsukka and Enugu Metropolis, Nigeria

2021 ◽  
pp. 124-132
Author(s):  
N. Chukwuma Lilian ◽  
B. Enweani Ifeoma ◽  
V. Udeogu Chidozie ◽  
Okwelogu Izunna Somadinna ◽  
O. Arua Chukwuemeka ◽  
...  
Keyword(s):  
Respiratory Infections ◽  
Culture Media ◽  
High Vacuum ◽  
Brain Heart Infusion ◽  
Airborne Fungi ◽  
Malt Extract ◽  
Indoor Environments ◽  
Sample Collection ◽  
Percentage Distribution ◽  
Significant Difference

Air borne fungi are transmitted through the air which can cause respiratory infections in human leading to allergies, asthma and diseases of the respiratory tract. The study is to determine the prevalence of fungi isolates in Enugu and Nsukka indoor prison environments and the possible effects on the respiratory tracts of the prison inmates. Institutions that accommodate large number of people such as Prisons, schools and hospitals are prone to airborne diseases due to overcrowded and unhygienic environment. The study was carried out using convenience sampling method and health based questionnaires. One hundred and forty (140)samples were analyzed consisting prison offices(48),inmates cells (28),lavatory (16),furniture(8),nasal swabs(20) and hostels(20). AC single impactor with high vacuum pump was used for indoor air sample collection; thermometer was used in measuring the temperature of the room and hygrometer for measuring the humidity. Sterile swab was used in collection of nasal samples, walls, furniture, toilets and bathrooms. Sabouraund dextrose agar (0.05µg Chloramphenicol and 1µg of Streptomycin), Malt extract agar, Chromagar, Brain heart infusion agar, and Nutrient agar were used for culture media for isolation of fungi respectively. The data generated from this research was analyzed using SPSS statistical software version 23.The result obtained showed that the percentage distribution of fungi isolates in prison offices were 60.9%, 57.4% in Nsukka and Enugu respectively while the percentage distribution percentage distribution of fungi isolates in prison cells were 42.6% and 39.1% in Enugu and Nsukka respectively. There was a significant difference in the distribution of fungal isolates at P=0.042.The indoor temperature and humidity of Enugu and Nsukka were the same at P using ANOVA, when compared with the hostels that served as control. Considering the public health effects of these airborne fungi, appropriate measures should be put in place in prison indoor environment to prevent the growth of moulds and yeast and its dissemination.

AWARENESS ABOUT INDOOR AIR POLLUTION IN GENERAL POPULATION OF RAWALPINDI AND ISLAMABAD

2018 ◽  
Vol 8 (2) ◽  
pp. 80-83
Author(s):  
Nadia Tariq ◽  
Tamkeen Jaffry ◽  
Rahma Fiaz ◽  
Abdul Majid Rajput ◽  
Sadaf Khalid
Keyword(s):  
Air Pollution ◽  
General Population ◽  
Indoor Air ◽  
Indoor Air Pollution ◽  
Economic Status ◽  
Educational Status ◽  
Epidemiological Studies ◽  
Cross Sectional Survey ◽  
Cross Sectional ◽  
Significant Difference

Background: Indoor air pollutants are increasingly being associated with respiratory illnesses leading to high degree of morbidity and mortality. There are not sufficient epidemiological studies from Pakistan which assess level of awareness of indoor air pollution resulting in respiratory diseases in population. Methods: This cross sectional survey was carried out on general population of Rawalpindi/Islamabad. Sample size was 223 study subjects selected by non-probability convenient sampling. Knowledge of the study subjects was determined with regard to indoor air pollution, its effects on health and different sources of indoor air pollution with the help of a questionnaire. The influence of age, gender, educational status and socio economic status on the level of awareness was also analyzed. Results: Out of total 223 participants, 115 were males and108 females. Participants aware of indoor air pollution were 91.5% and adequate awareness about its sources was 80.7%. Those who knew indoor air pollution is detrimental to health were 95.1%. Awareness about building construction dust as source of indoor air pollution was maximum (84.8%). There was significant difference in awareness among participants with different monthly incomes and educational status and also between males and females. Conclusion: This study concludes that general population of Rawalpindi/Islamabad has fairly good awareness about sources of indoor air pollution. Use of harmful material causing indoor air pollution should be limited or substituted with better ones where possible.

scholarly journals Exploiting the Advantages of Molecular Tools for the Monitoring of Fungal Indoor Air Contamination: First Detection of Exophiala jeanselmei in Indoor Air of Air-Conditioned Offices

2019 ◽  
Vol 7 (12) ◽  
pp. 674
Author(s):  
Xavier Libert ◽  
Camille Chasseur ◽  
Ann Packeu ◽  
Fabrice Bureau ◽  
Nancy H. Roosens ◽  
...  
Keyword(s):  
Indoor Air ◽  
Air Conditioning ◽  
Indoor Air Pollution ◽  
Airborne Fungi ◽  
Interesting Case ◽  
Public Health Issue ◽  
Molecular Tools ◽  
Exophiala Jeanselmei ◽  
Monitoring Protocols ◽  
Air Conditioning Systems

Today, indoor air pollution is considered a public health issue. Among the impacting pollutants, indoor airborne fungi are increasingly highlighted. Most of the monitoring protocols are culture-based, but these are unable to detect the uncultivable and/or dead fraction or species suppressed by fast-growing fungi, even though this fraction could impact health. Among the contaminants suspected to be part of this fraction, Exophiala jeanselmei is an interesting case study. Known to be pathogenic, this black yeast grows in humid environments such as air-conditioning systems, where it has been previously detected using classical culture-based methods. However, until now, this fungus was never detected in indoor air in contact with these air-conditioning systems. This study shows the first detection of E. jeanselmei in indoor air collected from offices in contact with contaminated air-conditioning reservoirs. While its presence in indoor air could not be demonstrated with culture-based methods, it was found by real-time PCR and massive parallel sequencing. The latter also allowed obtaining a broader view on the fungal diversity in the tested samples. Similar approaches were applied on water samples collected from the conditioning reservoirs to trace the source of contamination. The comparison of results obtained with both methods confirmed that the molecular tools could improve indoor air monitoring, especially of dead and/or uncultivable contaminants or when competition between species could occur.

scholarly journals Cefazolin plus Clavulanic Acid Overcomes the Inoculum Effect in a Methicillin-Susceptible Staphylococcus aureus (MSSA) Rat Endocarditis Model

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S12-S13
Author(s):  
William Miller ◽  
Kavindra Singh ◽  
Cesar Arias ◽  
Barbara Murray
Keyword(s):  
Clavulanic Acid ◽  
Brain Heart Infusion ◽  
Type A ◽  
Entire Volume ◽  
Colony Forming Units ◽  
Significant Difference ◽  
Inoculum Effect ◽  
Antibiotic Dose

Abstract Background The inoculum effect (InE) refers to an increase in the MIC of an antibiotic when a large burden of bacteria is present. MSSA producing type A or C β-lactamase (β-lac) that display this effect may be at risk of clinical failure when treated with cefazolin (CFZ) for a deep-seated infection. We have previously shown that CFZ plus clavulanic acid (CL) abolished the InE in vitro. The aim of this study was to evaluate the effectiveness of the combination in vivo at clinically achievable concentrations of both CFZ and CL. Methods S. aureus TX0117, a type A Bla+ clinical isolate from a patient who failed CFZ therapy and TX0117-cured (TX0117c), a derivative of TX0117 which lacks β-lac activity, were used in a rat model of endocarditis. One animal per strain, in addition to historical controls (n = 22), was sacrificed at the start of therapy to assess colony forming units (CFU) per gram of vegetation at T = 0. CFZ 50mg/kg alone (n = 11) or CFZ 50mg/kg plus CL 4mg/kg (n = 7) was given IM every 8 hours for 72 hours. Doses were selected to mimic mean serum concentration of standard doses (given IM (CFZ) or PO (CL)) in humans. Rats were sacrificed 16 hours after the last antibiotic dose, aortic valves were aseptically excised, weighed, homogenized in 1ml of saline and the entire volume was plated in serial 10-fold dilutions on mannitol salt and/or brain-heart infusion agar. Representative recovered colonies were tested for β-lac activity using nitrocefin. Comparisons of CFU between groups were done by the Mann–Whitney, Wilcoxon unpaired test with significance at p < 0.05. Results At baseline, there was no significant difference between the CFU/g of control animals infected with the two strains (TX0117 7.3±1.3 and TX0117c 7.89±0.83, mean log10 ± SD). Compared with untreated controls, the TX0117 group treated with CFZ alone had a reduction of 2±0.6 CFU/g, while the CFZ plus CL arm had a 7.1±0.5 CFU/g reduction, a statistically significant difference between the two arms (P = 0.0002). CFZ treatment of the TX0117c strain lacking blaZ activity was similar to CFZ+CL (6.5±0.6 log10 CFU/g reduction, P < 0.0001). Conclusion Against Bla+ TX0117, the addition of CL, at a dose mimicking human PO kinetics, restored the efficacy of CFZ and overcame the InE. This provides a proof-of-concept for the use of oral CL with CFZ when there is a concern for the InE. Disclosures All authors: No reported disclosures.

scholarly journals Selection, assessment of virulence to Alphitobius diaperinus, and Pr1 enzyme production of Beauveria bassiana (Bals.) Vuill. isolates cultured at stress temperatures

2015 ◽  
Vol 36 (6) ◽  
pp. 3529
Author(s):  
Kelly Christiane Constanski ◽  
Janaina Zorzetti ◽  
Pedro Manuel Oliveira Janeiro Neves
Keyword(s):  
Beauveria Bassiana ◽  
Alphitobius Diaperinus ◽  
Control Programs ◽  
Colony Forming Units ◽  
Significant Difference ◽  
Before And After ◽  
Insect Mortality ◽  
Selection Test ◽  
High And Low Temperatures ◽  
Fungus Beauveria Bassiana

The entomopathogenic fungus Beauveria bassiana is a promising agent for use in insect control. Its pathogenic activity, as well as other factors such as temperature that can interfere with its development, should be assessed, thus, establishing the foundations for B. bassiana use in biological control programs. The objective of this study was to select and induce tolerance of B. bassiana isolates to high and low temperatures and to assess their virulence before and after exposure to those temperatures. A pre-selection test was performed, in which the tolerance of isolates to stress temperatures was tested and compared to the ideal growth temperature of 25 °C for this organism. For the isolates/temperature combinations resulting in growth, conidia germination and colony-forming units (CFUs) were assessed. The isolates Unioeste 4 and Unioeste 40 exhibited >95% germinated conidia at 16 and 31 °C. Thereafter, they underwent four consecutive passages at maximum and minimum tolerated temperatures (10 and 37 °C). A significant difference in germination was observed between the two isolates at all temperatures tested. More CFUs were observed for Unioeste 4 compared to Unioeste 40 at all temperatures, and in the case of the latter, there was no difference in CFU formation at 10 and 25 °C. For both isolates, decreased vegetative growth was observed at 37 °C. Recovery of virulence was observed in both isolates, as determined by insect mortality. No relationship was observed between production of the enzyme Pr1 and the virulence of the isolates.

BCG shortage: Reassessing the clinical viability of Bacillus Calmette-Guerin (BCG) after reconstitution.

2020 ◽  
Vol 38 (6_suppl) ◽  
pp. 534-534 ◽  
Author(s):  
Nathan Brooks ◽  
Supriya Nagaraju ◽  
Justin T. Matulay ◽  
Xiang-Yang Han ◽  
Ashish M. Kamat
Keyword(s):  
Light Exposure ◽  
Positive Control ◽  
Negative Control ◽  
Split Dose ◽  
Time Points ◽  
Colony Forming Units ◽  
Significant Difference ◽  
Split Dosing ◽  
Student’S T ◽  
Practice Methods

534 Background: To address the current worldwide shortage of BCG, the AUA and SUO recommend reducing the dose to 1/3rd vial and enabling 3 patients to be treated in one setting. The manufacturer states that BCG must be used immediately after reconstitution, despite literature in the bacteriological world suggesting that M. Bovis might be viable for longer than a few hours. Herein we sought to study the viability of BCG after re-constitution at time points relevant to clinical practice. Methods: TICE BCG from separate lots was reconstituted per the manufacturer’s guidance and stored at 4 °C without light exposure. At predetermined time points, BCG was inoculated on Selective Middlebrook 7H11 agar in triplicate and incubated at 37°C with 5% CO2. M. smegmatis served as a positive control and un-inoculated media was incubated for 2 weeks as a negative control. CFUs were assessed between 3 and 4 weeks from plating. Acid-fast staining confirmed the presence of BCG. Data was analyzed as the mean of replicated experiments and compared to the reference (Time 0) using Student’s T-tests. Results: No significant difference in CFUs was observed for BCG between 0 and 8 hours after reconstitution (Table). Colony forming units significantly declined starting 24 hours after reconstitution, though the magnitude of this difference was less than 10 fold (which falls within the range of CFUs listed for the vial by manufacturer). Viability remained constant for both lots analyzed. Conclusions: Given the recurrent shortages of BCG, split dosing may become a clinical necessity. This often presents logistic quandaries since the manufacturer recommends each vial must be used within 2 hours. We have shown that the viability of TICE BCG is unaltered at least 8 hours after reconstitution and only begins to decline at 24 hours after reconstitution. This should allow pharmacists and physicians administering BCG more leeway in scheduling patients for split dose therapy. [Table: see text]

scholarly journals Antimicrobial Resistance Patterns in Women with Positive Urine Culture: Does Menopausal Status Make a Significant Difference?

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Pawel Miotla ◽  
Katarzyna Romanek-Piva ◽  
Michal Bogusiewicz ◽  
Ewa Markut-Miotla ◽  
Aneta Adamiak ◽  
...  
Keyword(s):  
Postmenopausal Women ◽  
Bacterial Infections ◽  
Urine Culture ◽  
Menopausal Status ◽  
Resistance Rate ◽  
Resistance Testing ◽  
Antimicrobial Drug Resistance ◽  
Colony Forming Units ◽  
Significant Difference ◽  
Resistance Patterns

Aim. Urinary tract infection (UTI) is considered one of the most common bacterial infections in women. The aim of this study was to investigate the types of uropathogens present, as well as the degree of antimicrobial drug resistance seen among premenopausal (n=2748) and postmenopausal (n=1705) women with uncomplicated UTI. Methods. Urinary samples (n=4453) collected from women with UTI were analyzed in terms of uropathogens present. These were considered as positive if bacterial growth was ≥105 colony forming units (CFUs)/mL. Susceptibility and resistance testing for commonly used antibiotics was subsequently assessed. Results. The most common uropathogens cultured from urine samples were Escherichia coli (65.5%), followed by Enterococcus faecalis (12.2%), Klebsiella pneumoniae (4.7%), and Proteus mirabilis (4.2%). The resistance to ampicillin exceeded 40%, independently of menopausal status. Of note, resistance to ciprofloxacin exceeded 25% among postmenopausal patients. Moreover, resistance of all uropathogens to commonly used antimicrobials was significantly higher in postmenopausal women. Conclusion. Due to the high resistance rate, ampicillin, ciprofloxacin, and the trimethoprim/sulfamethoxazole combination should be avoided in treating postmenopausal women affected by UTI without being indicated by initial urine culture report. Finally, cephalexin and cefuroxime are promising alternatives as initial treatment in postmenopausal women.

Bacterial survival and biofilm formation on conventional and antibacterial toothbrushes

Biofilms ◽  
2004 ◽  
Vol 1 (2) ◽  
pp. 123-130 ◽  
Author(s):  
R. L. Sammons ◽  
D. Kaur ◽  
P. Neal
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Staphylococcus Epidermidis ◽  
Biofilm Formation ◽  
Bacterial Survival ◽  
Opportunistic Pathogens ◽  
Mechanical Agitation ◽  
Gram Staining ◽  
Colony Forming Units ◽  
Significant Difference ◽  
Number Of Bacteria

The aim of this study was to investigate bacterial survival and biofilm formation on toothbrushes. Fifteen healthy volunteers each used a normal toothbrush and an antibacterial toothbrush of the same design for two separate 5 week periods. Bacteria were removed from the brush head by swabbing and mechanical agitation in 10ml of tryptone soya broth, cultured aerobically on selective and non-selective media, and classified by Gram staining, catalase and oxidase tests. Survival of Staphylococcus epidermidis and Pseudomonas aeruginosa was monitored in the laboratory on both types of brush over 8 days. Scanning electron microscopy was used to observe biofilm formation on antibacterial and conventional brushes used for various times. Numbers of bacteria isolated from conventional and antibacterial brushes from different individuals ranged from 8.3×103 to 4.7×106 and from 1×102 to 1.2×106 colony-forming units/ml, respectively. A larger number of bacteria were isolated from conventional brushes than from antibacterial brushes used by the same individuals but no statistically significant difference was demonstrated. No differences in the relative proportions of Gram-negative and Gram-positive rods or cocci were seen. Staphylococci, presumptive coliforms and pseudomonads were isolated from 48%, 28% and 16% of brushes, respectively. Pseudomonas aeruginosa was viable for at least 4 days on conventional, and 2–3 days on antibacterial, brushes, whilst S. epidermidis survived for 6–8 days on antibacterial and more than 8 days on conventional brushes. Biofilms formed on the heads and bristles of both conventional and antibacterial brushes. Extensive, mixed community biofilms developed after several months of use. We conclude that toothbrushes may be a reservoir of opportunistic pathogens including staphylococci and pseudomonad-like organisms and must be considered as a potential source of haematogenous infections and cross-infection.

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