Management of Listeria monocytogenes on Surfaces via Relative Air Humidity: Key Role of Cell Envelope

Although relative air humidity (RH) strongly influences microbial survival, its use for fighting surface pathogens in the food industry has been inadequately considered. We asked whether RH control could destroy Listeria monocytogenes EGDe by envelope damage. The impact of dehydration in phosphate-buffered saline (PBS) at 75%, 68%, 43% and 11% RH on the bacterial envelope was investigated using flow cytometry and atomic force microscopy. Changes after rehydration in the protein secondary structure and peptidoglycan were investigated by infrared spectroscopy. Complementary cultivability measurements were performed by running dehydration–rehydration with combinations of NaCl (3–0.01%), distilled water, city water and PBS. The main results show that cell membrane permeability and cell envelope were greatly altered during dehydration in PBS at 68% RH followed by rapid rehydration. This damage led cells to recover only 67% of their initial volume after rehydration. Moreover, the most efficient way to destroy cells was dehydration and rehydration in city water. Our study indicates that rehydration of dried, sullied foods on surfaces may improve current cleaning procedures in the food industry.

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Relationship between preterm birth and air pollution in Santos, Sao Paulo, Brazil

European Journal of Public Health ◽

10.1093/eurpub/ckaa166.111 ◽

2020 ◽

Vol 30 (Supplement_5) ◽

Author(s):

M E L Brandao ◽

B A L F Braga ◽

M L C Martins ◽

P L A A Pereira

Keyword(s):

Air Pollution ◽

Preterm Birth ◽

Air Pollutants ◽

First Trimester ◽

Sao Paulo ◽

São Paulo ◽

Air Humidity ◽

Relative Air Humidity ◽

The Impact ◽

Fourth Quartile

Abstract Santos is a seaboard Brazilian city recognized by its port activity where the road and rail infrastructure along with the large transportation operation, displays an important factor to contribute with all kinds of toxic and air pollutants. Recent studies have suggested associations between air pollution and various birth outcomes. Pollutant gases such as NOx, O3 and particulate matter PM2,5, PM10 have been cited as factors involved in such outcomes. The present study aims to assess the relationship between atmospheric pollutants and perinatal outcomes in the city of Santos from Jan. 2012 to Dec. 2015. Cross-sectional study that analyzed 10.319 singleton births in an area set with 2 km radius of the monitoring stations. Birth weight and information on mother and pregnancy were obtained at the Brazilian “Born Alive National Information System”. Daily records of air pollutants (PM10, PM2.5, NO2 and O3), temperature and relative air humidity, for the study period, were obtained from São Paulo State Environmental Agency (CETESB). Associations between preterm birth and air pollutants mean levels at each gestational trimester were investigated using multiple logistic regression model controlled by the variables: infant sex, type of delivery, maternal education. prenatal care, and number of previous live births, temperature and relative air humidity. NO2 e PM2,5 was not associated with preterm birth. O3 was significantly associated in the first trimester in the fourth quartile (OR = 1,47 CI 95% 1,05; 2,07). PM10 was significantly associated in the first trimester for the fourth quartile (OR = 1,28 CI 95% 1,00; 1,64), second trimester for the second quartile (OR = 1,37 CI 95% 1,07; 1,77). Conclusions the results shows evidence that maternal exposure to air pollution especially during the first trimester of pregnancy may contribute to preterm birth. Further actions are needed towards controlling air pollution are strongly recommended for promoting early-life health. Key messages This is the first research of this kind that was made in Santos. It brings important evidence of the impact in the life of the population, especially those whose is not even born yet. It can be used as a resource to guide public policies in health, especially the guidelines that dictate the concentration of air pollutants and air quality.

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Plasma-treated water affects Listeria monocytogenes vitality and biofilm formation

10.21203/rs.3.rs-31328/v1 ◽

2020 ◽

Author(s):

Oliver Handorf ◽

Viktoria Isabella Pauker ◽

Thomas Weihe ◽

Uta Schnabel ◽

Eric Freund ◽

...

Keyword(s):

Listeria Monocytogenes ◽

Biofilm Formation ◽

Food Industry ◽

Microwave Plasma ◽

Industrial Applications ◽

Bacterial Biofilm ◽

Treated Water ◽

Force Microscopy ◽

Cell Vitality ◽

Pretreatment Time

Abstract Plasma-generated compounds (PGCs) such as plasma-processed air (PPA) or plasma-treated water (PTW) offer an increasingly important alternative for the treatment of microorganisms in hard-to-reach areas found in several industrial applications including the food industry. To this end, we studied the antimicrobial capacity of plasma-treated water on the vitality and biofilm formation of Listeria monocytogenes, a common food spoilage microorganism. Using a microwave plasma (MidiPLexc), 10 ml of deionized water was treated for 100 s, 300 s and 900 s (pretreatment time) and the bacterial biofilm was subsequently exposed to the PTW for 1 min, 3 min and 5 min (posttreatment time) for each pretreatment time separately. Colony-forming units (CFU), metabolic activity, and cell vitality were reduced for 4.7 log10, 47.9%, and 69.5%, respectively. Live/dead staining and fluorescence microscopy showed a positive correlation between treatment and incubation times and reduction in vitality. Atomic force microscopy indicated a change in the plasticity of the bacteria. These results suggest a promising antimicrobial impact of plasma-treated water on Listeria monocytogenes, which may lead to more targeted applications of plasma decontamination in the food industry in the future.

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Experimental Measurement of the CO2 Content in a Passive Home during a Simulated Air-Conditioning Power Outage

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.752-753.1187 ◽

2015 ◽

Vol 752-753 ◽

pp. 1187-1190

Author(s):

Zdenek Galda ◽

Jiri Labudek ◽

Veronika Sipkova

Keyword(s):

Experimental Measurement ◽

Air Conditioning ◽

Blood Circulation ◽

Air Humidity ◽

Power Outage ◽

Sleeping Time ◽

Relative Air Humidity ◽

High Concentrations ◽

The Impact ◽

Resting Period

High concentrations of CO2 are one of the causes of imperfect oxygenation of the blood circulation in humans. An experimental measurement of a passive home during a simulated power outage was carried out from July 7-15th 2014. In the measured rooms (one with plants with leaves the size of one of the bigger participants in this project, the second room without any plants at all), the levels of CO2 were observed, as well as the levels of relative air humidity of the interior, and the interior temperature. The measurement was carried out at night, when sleeping time was simulated, i.e. the resting period. The impact of plants did not significantly influence the CO2 reduction in the interior of the building. Regular airing is necessary for maintaining the hygienic limit of the concentration of CO2. It is thus necessary to ensure this with the windows open during an unexpected power outage.

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Environmental Assessment of the Impact of Meteorological Parameters on Man-Made Pollution by Carcinogenicly Dangerous Chemicals in the Voronezh Air Basin

Ecology and Industry of Russia ◽

10.18412/1816-0395-2021-2-60-65 ◽

2021 ◽

Vol 25 (2) ◽

pp. 60-65

Author(s):

S.A. Kurolap ◽

V.S. Petrosyan ◽

O.V. Klepikov ◽

V.V. Kulnev ◽

D.Yu. Martynov

Keyword(s):

Wind Speed ◽

Air Temperature ◽

Meteorological Parameters ◽

Carcinogenic Risk ◽

Meteorological Conditions ◽

Air Humidity ◽

Maximum Permissible Level ◽

Relative Air Humidity ◽

The Impact ◽

The City

Based on the analysis of official statistics from the Voronezh Hydrometeorological Service, the patterns of the dynamics of pollutants (formaldehyde and soot) are investigated depending on the combination of various meteorological parameters — air temperature, wind speed, relative air humidity. A positive relationship has been established between the increase in atmospheric pollution with formaldehyde and air temperature. With increasing wind speed and relative humidity, the concentration of formaldehyde and soot in the atmosphere of the city, as a rule, decrease. The maximum permissible level of carcinogenic risk to public health has been established, causing concern. The obtained patterns can be used to predict the level of technogenic pollution of the city’s atmosphere, depending on meteorological conditions.

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Bursting out: linking changes in nanotopography and biomechanical properties of biofilm-forming Escherichia coli to the T4 lytic cycle

npj Biofilms and Microbiomes ◽

10.1038/s41522-021-00195-7 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Shiju Abraham ◽

Yair Kaufman ◽

François Perreault ◽

Ry Young ◽

Edo Bar-Zeev

Keyword(s):

Cell Envelope ◽

Biomechanical Properties ◽

Lytic Cycle ◽

Planktonic Cells ◽

Force Microscopy ◽

Bacteriophage Infection ◽

Atomic Force ◽

Biofilm Removal ◽

Infected Cells ◽

The Impact

AbstractThe bacteriophage infection cycle has been extensively studied, yet little is known about the nanostructure and mechanical changes that lead to bacterial lysis. Here, atomic force microscopy was used to study in real time and in situ the impact of the canonical phage T4 on the nanotopography and biomechanics of irreversibly attached, biofilm-forming E. coli cells. The results show that in contrast to the lytic cycle in planktonic cells, which ends explosively, anchored cells that are in the process of forming a biofilm undergo a more gradual lysis, developing distinct nanoscale lesions (~300 nm in diameter) within the cell envelope. Furthermore, it is shown that the envelope rigidity and cell elasticity decrease (>50% and >40%, respectively) following T4 infection, a process likely linked to changes in the nanostructure of infected cells. These insights show that the well-established lytic pathway of planktonic cells may be significantly different from that of biofilm-forming cells. Elucidating the lysis paradigm of these cells may advance biofilm removal and phage therapeutics.

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The impact of barriers inside a herringbone milking parlour on efficiency of the ventilation system

Annals of Animal Science ◽

10.2478/v10220-012-0048-9 ◽

2012 ◽

Vol 12 (4) ◽

pp. 575-584 ◽

Cited By ~ 2

Author(s):

Piotr Herbut ◽

Sabina Angrecka ◽

Grzegorz Nawalany

Keyword(s):

Mechanical Ventilation ◽

Working Conditions ◽

Ventilation System ◽

Movement Pattern ◽

Air Humidity ◽

Air Movement ◽

Relative Air Humidity ◽

Proper Design ◽

Microclimatic Conditions ◽

The Impact

AbstractThe research aimed at establishing the pattern of air movement inside a 2×10 herringbone milking parlour equipped with supply mechanical ventilation. Observations and analyses were made for the streams of air supplied to the parlour, their movement pattern and spread range. Also, temperature and relative air humidity after and before evening milking routine were measured. It has been concluded that barriers installed inside the milking parlour play a significant role in creating unfavourable microclimatic conditions during milking, particularly for the last group of cows. The study points out possible threats to animal welfare and operator’s working conditions. Based on the conducted experiments, the paper defines recommendations for proper design of ventilation systems inside herringbone milking parlours.

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Bursting out: linking changes in nano-topography and biomechanical properties of biofilm-forming Escherichia coli to T4 lytic cycle

10.1101/2020.06.29.176883 ◽

2020 ◽

Author(s):

Shiju Abraham ◽

Yair Kaufman ◽

François Perreault ◽

Ry Young ◽

Edo Bar-Zeev

Keyword(s):

Cell Envelope ◽

Biomechanical Properties ◽

Lytic Cycle ◽

Planktonic Cells ◽

Force Microscopy ◽

E Coli ◽

Bacteriophage Infection ◽

Atomic Force ◽

Biofilm Removal ◽

The Impact

ABSTRACTBacteriophage infection cycle has been extensively studied, yet little is known on the structural and mechanical changes that lead to bacterial lysis. Here, bio-atomic force microscopy was used to study in real-time and in-situ the impact of the canonical phage T4 on the nano-topography and biomechanics of irreversibly attached, biofilm-forming E. coli cells. The results show that in contrast to the lytic cycle in planktonic cells, which ends explosively, anchored cells that are in the process of forming biofilms undergo gradual lysis, developing distinct sub-micron lesions (∼300 nm in diameter) within the cell envelope. Furthermore, it is shown that the envelope rigidity and cell elasticity decrease (>50% and >40%, respectively) following T4 infection. These new insights show that the well-established lytic pathway of planktonic cells may be significantly different from that of biofilm-forming cells. Elucidating the lysis paradigm of these cells may advance biofilm removal and phage therapeutic.There is no conflict of interest and all co-authors have seen and approved the current version for submission.

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Control of Relative Air Humidity as a Potential Means to Improve Hygiene on Surfaces: A Preliminary Approach with Listeria monocytogenes

PLoS ONE ◽

10.1371/journal.pone.0148418 ◽

2016 ◽

Vol 11 (2) ◽

pp. e0148418 ◽

Cited By ~ 27

Author(s):

Fiona Zoz ◽

Cyril Iaconelli ◽

Emilie Lang ◽

Hayet Iddir ◽

Stéphane Guyot ◽

...

Keyword(s):

Listeria Monocytogenes ◽

Air Humidity ◽

Relative Air Humidity

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Forecasting Heat Stress in Dairy Cattle in Selected Barn Zones with the Help of Thi and Thiadj Indexes / Prognozowanie Stresu Cieplnego U Bydła Mlecznego W Wybranych Strefach Obory Za Pomocą Wskaźników Thi I Thiadj

Annals of Animal Science ◽

10.2478/aoas-2013-0029 ◽

2013 ◽

Vol 13 (4) ◽

pp. 837-848 ◽

Cited By ~ 4

Author(s):

Piotr Herbut ◽

Sabina Angrecka

Keyword(s):

Heat Stress ◽

Solar Radiation ◽

Air Humidity ◽

Movement Velocity ◽

Air Movement ◽

Relative Air Humidity ◽

Microclimatic Conditions ◽

Hot Weather ◽

The Impact ◽

Occupied Zone

Abstract The paper presents the influence of temperature, relative air humidity, air movement velocity and solar radiation on forecasting the risk of heat stress in dairy cows in a free-stall barn during hot weather seasons. THI and adjusted THI indexes were calculated for the periods in which the air temperature exceeded 28°C in the barn, and when it reached 25°C. Based on the THI values obtained during the heat, which ranged from 63 to 83, the occurrence of heat stress in cattle was stated. Heat stress also caused a decrease in milk yield, from about 22 kg to about 18 kg in the technological group. The calculated THIadj values (83 to 90), taking into account the solar radiation and air movement velocity, indicated also the occurrence of health-threatening conditions for cattle. On the fourth day of heat the maximum daily value of THI in the first measurement point was 83 with THIadj of 90, while in the second point THI was 82 and THIadj was 87. This indicated the occurrence of significant differences in microclimatic conditions in the occupied zone of the same technological group. The influence of investigated microclimate factors on the formation of THIadj in the researched zone of the barn was stated. No proper method of its determination was also stated. The analysis of the impact of air movement velocity on THIadj value (P<0.05) and the solar radiation (P<0.05) demonstrated the importance of these parameters in forecasting heat stress in cows in the barn.

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Responses of Rice Growth to Day and Night Temperature and Relative Air Humidity—Dry Matter, Leaf Area, and Partitioning

Plants ◽

10.3390/plants8110521 ◽

2019 ◽

Vol 8 (11) ◽

pp. 521

Author(s):

Stuerz ◽

Asch

Keyword(s):

Leaf Area ◽

Mass Fraction ◽

Dry Matter ◽

Negative Impact ◽

Effect Of Temperature ◽

Plant Responses ◽

Air Humidity ◽

Night Temperature ◽

Relative Air Humidity ◽

The Impact

Asymmetric changes of day and night temperature have already been observed because of Climate Change. However, knowledge on environmental conditions either during day or night serving as trigger for growth processes is scarce. In this study, one rice (Oryza sativa) variety (IR64) was examined to assess the impact of varying temperatures and relative air humidities during day and night periods on biomass, leaf area, and dry matter partitioning between organs. Three different day and night temperature (30/20 °C, 25/25 °C, 20/30 °C) and relative air humidity (40/90%, 65/65%, 90/40%) regimes were established. The effect of relative air humidity on both plant dry matter and leaf area was larger than the effect of temperature, in particular low humidity had a strong negative impact during the night. With high day temperature, the shoot mass fraction increased, whereas the root mass fraction decreased. Specific leaf area increased at high night temperatures and led, along with the high leaf mass fraction at high night humidities, to higher growth rates. The results emphasize the importance of considering relative air humidity when focusing on plant responses to temperature, and strongly suggest that under asymmetric day and night temperature increases in the future, biomass partitioning rather than biomass itself will be affected.

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