scholarly journals A Comparison of Flavorless Electronic Cigarette-Generated Aerosol and Conventional Cigarette Smoke on the Survival and Growth of Common Oral Commensal Streptococci

2019 ◽  
Vol 16 (10) ◽  
pp. 1669 ◽  
Author(s):  
Giancarlo A. Cuadra ◽  
Maxwell T. Smith ◽  
John M. Nelson ◽  
Emma K. Loh ◽  
Dominic L. Palazzolo
Keyword(s):  
Cigarette Smoke ◽  
Biofilm Formation ◽  
Electronic Cigarettes ◽  
Biological Effects ◽  
Bacterial Survival ◽  
Post Exposure ◽  
Peristaltic Pumps ◽  
Colony Forming Units ◽  
Survival And Growth ◽  
Modest Effect

Background: The use of electronic cigarettes (ECIG) has become very common. Consequently, critical analysis of the biological effects of ECIG aerosol deserves attention. Flavorless ECIG aerosol is known to comprise fewer harmful constituents than cigarette smoke. Therefore, we hypothesize that aerosol has less immediate effect on the viability of oral commensal streptococci than smoke. Methods: Survival and growth of four strains of commensal streptococci were measured after exposure to flavorless ECIG aerosol ± nicotine and smoke. Peristaltic pumps were used to transport aerosol or smoke into chambers containing recently seeded colony-forming units (CFUs) of the oral commensal streptococci on agar plates. Bacterial survival and growth, based on colony counts and sizes, were determined 24 h post-exposure. Additionally, aerosol or smoke were delivered into chambers containing pre-adhered streptococci to plastic coverslips and biofilm formation was determined 24 h post-exposure via scanning electron microscopy. Results: The results suggest that flavorless aerosol ± nicotine has a modest effect on bacterial growth both as colonies on agar and as biofilms. In contrast, smoke dramatically decreased bacterial survival and growth in all parameters measured. Conclusion: Unlike cigarette smoke, flavorless ECIG aerosol has only a small effect on the survival and growth of oral commensal streptococci.

scholarly journals Effects of flavorless electronic cigarette aerosol on the survival and growth of common oral commensal streptococci

2019 ◽  
Author(s):  
Giancarlo A. Cuadra ◽  
Maxwell Smith ◽  
John M. Nelson ◽  
Emma Loh ◽  
Dominic Palazzolo
Keyword(s):  
Cigarette Smoke ◽  
Electronic Cigarettes ◽  
Biological Effects ◽  
Oral Bacteria ◽  
Bacterial Survival ◽  
Post Exposure ◽  
Peristaltic Pumps ◽  
Colony Forming Units ◽  
Survival And Growth ◽  
Modest Effect

AbstractThe use of electronic cigarettes (ECIG) has become very common. Consequently, critical analysis of the biological effects of ECIG aerosol deserves attention. Since the mouth is the first anatomical cavity exposed to aerosol, the oral bacteria within are also exposed. We hypothesize that while cigarette smoke has a detrimental effect on the survival and growth of oral commensal streptococci, flavorless ECIG aerosol does not. Survival and growth of several strains of commensal streptococci were measured after exposure to flavorless ECIG aerosol ± nicotine and smoke. Peristaltic pumps were used to transport flavorless aerosol ± nicotine or cigarette smoke into chambers containing recently seeded colony forming units of four strains of oral commensal streptococci on agar plates. Bacterial survival and growth, based on colony counts and sizes, were determined 24 hours post-exposure. Lastly, aerosol or smoke were delivered into chambers containing the four strains of streptococci pre-adhered to plastic coverslips. Bacterial survival and growth, as indicated by biofilm formation, were determined 24 hours post-exposure via scanning electron microscopy. The results suggest that flavorless aerosol ± nicotine has a modest effect on bacterial growth both as colonies on agar and as biofilms. In contrast, smoke dramatically decrease bacterial survival and growth in all parameters measured. Therefore, unlike cigarette smoke, flavorless ECIG aerosol has only a small effect on the survival and growth of oral commensal streptococci.

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.

scholarly journals JUUL and Combusted Cigarettes Comparably Impair Endothelial Function

2019 ◽  
Author(s):  
Poonam Rao ◽  
Jiangtao Liu ◽  
Matthew L. Springer
Keyword(s):  
Endothelial Function ◽  
Health Effects ◽  
Cigarette Smoke ◽  
Electronic Cigarettes ◽  
The Other ◽  
Post Exposure ◽  
Previous Generation ◽  
Tank System ◽  
Clean Air

ABSTRACTObjectivesJUUL and earlier generation electronic cigarettes (e-cigs) are promoted as being less hazardous than cigarettes. While JUUL Labs, in particular, claims that switching from smoking to vaping has beneficial impacts, the health effects of such products are not well understood. We investigated whether exposure to JUUL and previous generation e-cig aerosol impairs endothelial function comparably to cigarette smoke.MethodsWe exposed rats to aerosol from Virginia Tobacco flavor JUUL, an e-cig tank system using unflavored freebase nicotine e-liquid, Marlboro Red combustible tobacco cigarettes, or clean air for 10 cycles of 2 second inhalation over 5 minutes. Endothelial function (FMD) was measured pre- and post-exposure. Blood was collected 20 mins post-exposure for serum nicotine analysis.ResultsAerosol/smoke from JUUL, previous generation e-cigs, and cigarettes all impaired FMD. The extent of impairment ranged from 34%-58%, although the differences between groups were insignificant. Nicotine was highest in serum from the JUUL group; for the other e-cig and cigarette groups, nicotine levels were lower and comparable to each other.ConclusionsAerosol from JUUL and previous generation e-cigs impairs endothelial function in rats, comparable to impairment by cigarette smoke.

scholarly journals JUUL and Combusted Cigarettes Comparably Impair Endothelial Function

2020 ◽  
Vol 6 (1) ◽  
pp. 30-37 ◽  
Author(s):  
Poonam Rao ◽  
Jiangtao Liu ◽  
Matthew L. Springer
Keyword(s):  
Endothelial Function ◽  
Health Effects ◽  
Cigarette Smoke ◽  
Electronic Cigarettes ◽  
The Other ◽  
Free Base ◽  
Post Exposure ◽  
Previous Generation ◽  
Tank System ◽  
Clean Air

Objectives: JUUL and earlier generation electronic cigarettes (e-cigs) are promoted as being less hazardous than cigarettes. JUUL Labs, in particular, claims that switching from smoking to vaping has beneficial impacts; however, the health effects of such products are not well understood. We investigated whether exposure to JUUL and previous generation e-cig aerosol impairs endothelial function comparably to cigarette smoke. Methods: We exposed rats to aerosol from Virginia Tobacco flavor JUUL, an e-cig tank system using unflavored free-base nicotine e-liquid, Marlboro Red combustible tobacco cigarettes, or clean air for 10 cycles of 2 second inhalation over 5 minutes. We measured endothelial function pre- and post-exposure. Blood was collected 20 minutes post-exposure for serum nicotine analysis. Results: Aerosol/smoke from JUUL, previous generation e-cigs, and cigarettes all impaired endothelial function. The extent of impairment ranged from 34% to 58%, although the differences between groups were not statistically significant. Nicotine was highest in serum from the JUUL group; for the other e-cig and cigarette groups, nicotine levels were lower and comparable to each other.Conclusions: Aerosol from JUUL and previous generation e-cigs impairs endothelial function in rats, comparable to impairment by cigarette smoke.

Monolithic Ceramics: Effect of Finishing Techniques on Surface Properties, Bacterial Adhesion and Cell Viability

2018 ◽  
Vol 43 (3) ◽  
pp. 315-325 ◽  
Author(s):  
AMO Dal Piva ◽  
LPC Contreras ◽  
FC Ribeiro ◽  
LC Anami ◽  
SEA Camargo ◽  
...  
Keyword(s):  
Mtt Assay ◽  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Nonparametric Tests ◽  
Lithium Silicate ◽  
Gingival Fibroblasts ◽  
Sem Images ◽  
High Profile ◽  
Colony Forming Units ◽  
Monolithic Ceramics

SUMMARY Introduction: This study evaluated the morphology, biofilm formation, and viability of human gingival fibroblasts in contact with two monolithic ceramics after two different finishing techniques: polishing or glazing. For this, 92 blocks (4.5 × 4.5 × 1.5 mm) of each ceramic were made using high translucency zirconia partially stabilized by yttrium (YZHT) and lithium silicate reinforced by zirconium (ZLS). Methods and Materials: Blocks were sintered and then divided into glazing (g) or polishing (p) surface finish. Surface roughness (Ra and RSm) was evaluated through a contact rugosimeter and profilometry. Specimens were contaminated for heterotypic biofilm formation with Streptococcus mutans, Streptococcus sanguinis and Candida albicans for 16 hours. Biofilm was quantified by counting the colony forming units (CFU/mL) and analyzed by scanning electron microscopy (SEM). Fibroblast viability was evaluated by MTT assay. Surface free energy (SFE) was also determined. Roughness data were evaluated using nonparametric tests, while SFE, MTT and CFU results were evaluated by analysis of variance and Tukey test, and MTT data were also submitted to t-test (all, α=0.05). Results: Results showed that polished samples presented a lower high profile mean (p<0.001); however, YZHTg presented less space between defects (p=0.0002). SFE showed that YZHT presented higher SFE than ZLS. Profilometry evidenced more homogeneity on polished surfaces. The interaction of finishing technique and microorganisms influenced the CFU (p=0.00). MTT assay demonstrated initial severe cytotoxic behavior for polished surfaces. SEM images showed homogeneous surfaces, except for glazed YZHT. Conclusion: Glazed surfaces have a greater roughness and tend to accumulate more biofilm. Polished surfaces have higher SFE; however, they are temporarily cytotoxic.

scholarly journals THE EFFECT OF PROPOLIS EXTRACT AND PROPOLIS CANDIES ON THE GROWTH OF AGGREGATIBACTER ACTINOMYCETEMCOMITANS ATCC 43718

2017 ◽  
Vol 10 (17) ◽  
pp. 26
Author(s):  
Khodijah Khodijah ◽  
Ratna Farida ◽  
Nurtami Soedarsono
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Minimum Bactericidal Concentration ◽  
Aggregatibacter Actinomycetemcomitans ◽  
Spectrophotometric Analysis ◽  
Propolis Extract ◽  
Post Exposure ◽  
Colony Forming Units

Objective: This experiment aimed to analyze the effect of propolis extract and propolis containing candies on the growth of Aggregatibacter actinomycetemcomitans using spectrophotometric analysis and colony-forming units (CFU) counts.Methods: After A. actinomycetemcomitans were exposed to propolis extract and candies, the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined with spectrophotometry and post-exposure colony counting.Results: The MIC of propolis extract against A. actinomycetemcomitans was determined to be 10%, and the MBC was 20%. A decrease in the total CFU count of A. actinomycetemcomitans was observed after propolis extract and candy exposure.Conclusions: Propolis extract and propolis candies were effective in inhibiting the growth of A. actinomycetemcomitans ATCC 43718 in vitro.

scholarly journals Oxygen tension during biofilm growth influences the efficacy antimicrobial agents

2016 ◽  
Vol 45 (5) ◽  
pp. 302-307 ◽  
Author(s):  
Raquel Pippi ANTONIAZZI ◽  
Gabriela Ocampo TROJAHN ◽  
Maísa CASARIN ◽  
Camilla Filippi dos Santos ALVES ◽  
Roberto Christ Vianna SANTOS ◽  
...  
Keyword(s):  
Green Tea ◽  
Oxygen Tension ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Dental Students ◽  
Low Oxygen ◽  
Biofilm Growth ◽  
Model Method ◽  
Colony Forming Units

Abstract Objective To compare the antimicrobial efficacy of a 0.12% chlorhexidine (CHX) and herbal green tea (Camellia sinensis) solution on established biofilms formed at different oxygen tensions in an in situ model. Method Twenty-five dental students were eligible for the study. In situ devices with standardized enamel specimens (ES) facing the palatal and buccal sides were inserted in the mouths of volunteers for a 7 day period. No agent was applied during the first four days. From the fifth day onward, both agents were applied to the test ES group and no agent was applied to the control ES group. After 7 days the ES fragments were removed from the devices, sonicated, plated on agar, and incubated for 24 h at 37 °C to determine and quantify the colony forming units (CFUs). Result CHX had significantly higher efficacy compared to green tea on the buccal (1330 vs. 2170 CFU/µL) and palatal (2250 vs. 2520 CFU/µL) ES. In addition, intragroup comparisons showed significantly higher efficacy in buccal ES over palatal ES (1330 vs. 2250 CFU/µL for CHX and 2170 vs, 2520 CFU/µL for CV) for both solutions. Analysis of the ES controls showed significantly higher biofilm formation in palatal ES compared to buccal ES. Conclusion CHX has higher efficacy than green tea on 4-day biofilms. The efficacy of both agents was reduced for biofilms grown in a low oxygen tension environment. Therefore, the oxygen tension environment seems to influence the efficacy of the tested agents.

Exposure to Cadmium and Lead in Cigarette Smokers Who Switched to Electronic Cigarettes

2018 ◽  
Vol 21 (9) ◽  
pp. 1198-1205 ◽  
Author(s):  
Adam Prokopowicz ◽  
Andrzej Sobczak ◽  
Magdalena Szuła-Chraplewska ◽  
Patryk Ochota ◽  
Leon Kośmider
Keyword(s):  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Cigarette Smoke ◽  
Electronic Cigarettes ◽  
Geometric Mean ◽  
Electrothermal Atomic Absorption Spectrometry ◽  
Absorption Spectrometry ◽  
Lower Amount ◽  
Cigarette Smokers ◽  
Cd Exposure

Abstract Introduction Electronic cigarettes (ECs) seem to be a less harmful alternative for conventional cigarettes. This study aimed to assess whether the generated aerosols from ECs contain lower amount of cadmium (Cd) and lead (Pb) than cigarette smoke and to detect any changes in exposure to Cd and Pb among cigarette smokers who switched completely or partially to EC. Methods EC aerosols and cigarette smoke were generated, and the determination of Cd and Pb in trapped samples and e-liquids was performed by the electrothermal atomic absorption spectrometry method. A cross-sectional, group-based survey was carried out using 156 volunteers classified into groups of nonsmokers, EC-only users, dual EC users-cigarette smokers, and cigarette-only smokers. Using electrothermal atomic absorption spectrometry, blood Cd and Pb levels were measured, and the results were compared by analysis of covariance. Results Transfer of Cd and Pb to EC aerosol was found to be minimal, although the metals were present in the remaining e-liquid from tanks used for vapor generation. The geometric mean blood Cd concentration adjusted for age and sex was 0.44 (95% confidence interval = 0.37 to 0.52) µg/L in the EC-only users, which was significantly lower than those in the smokers of 1.44 (1.16 to 1.78) and dual users of 1.38 (1.11 to 1.72). The blood Pb geometric mean differed significantly only between nonsmokers of 11.9 (10.6 to 13.3) and smokers of 15.9 (13.6 to 18.6). Conclusion The study revealed that smokers who completely switched to ECs and quit smoking conventional cigarettes may significantly reduce their exposure to Cd and probably Pb. Implications Switching to EC use is associated with a rapid and substantial decrease in the exposure to carcinogenic Cd. Exposure to Pb is probably also decreased but may be overshadowed by other factors. The study provides empirical data based not only on the analysis of generated aerosol but also on biological indicators of recent exposure—that is, the concentrations of Cd and Pb in blood, indicating EC as a potential harm-reduction device, especially regarding Cd exposure. However, in this case, dual EC use-cigarette smoking provides doubtful benefits.

scholarly journals Structural insights into the mechanism of c-di-GMP–bound YcgR regulating flagellar motility in Escherichia coli

2019 ◽  
Vol 295 (3) ◽  
pp. 808-821 ◽  
Author(s):  
Yan-Jie Hou ◽  
Wen-Si Yang ◽  
Yuan Hong ◽  
Ying Zhang ◽  
Da-Cheng Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Motor Proteins ◽  
Flagellar Motor ◽  
Bacterial Survival ◽  
Flagellar Motility ◽  
Surface Attachment ◽  
Bacterial Surface ◽  
Motility Regulation ◽  
Survival And Growth ◽  
Structural Insights

The motile-sessile transition is critical for bacterial survival and growth. Cyclic-di-GMP (c-di-GMP) plays a central role in controlling this transition and regulating biofilm formation via various effectors. As an effector of c-di-GMP in Escherichia coli and related species, the PilZ domain–containing protein YcgR responds to elevated c-di-GMP concentrations and acts on the flagellar motor to suppress bacterial motility in a brakelike fashion, which promotes bacterial surface attachment. To date, several target proteins within the motor, MotA, FliG, and FliM, along with different regulatory mechanisms have been reported. However, how YcgR acts on these components remains unclear. Here, we report that activated YcgR stably binds to MotA at the MotA-FliG interface and thereby regulates bacterial swimming. Biochemical and structural analyses revealed that c-di-GMP rearranges the PilZ domain configuration, resulting in the formation of a MotA-binding patch consisting of an RXXXR motif and the C-tail helix α3. Moreover, we noted that a conserved region in the YcgR-N domain, which is independent of MotA interaction, is necessary for motility regulation. On the basis of these findings, we infer that the YcgR-N domain is required for activity on other motor proteins. We propose that activated YcgR appends to MotA via its PilZ domain and thereby interrupts the MotA-FliG interaction and simultaneously interacts with other motor proteins via its YcgR-N domain to inhibit flagellar motility. Our findings suggest that the mode of interaction between YcgR and motor proteins may be shared by other PilZ family proteins.

scholarly journals Relationship Between Membrane Vesicles, Extracellular ATP and Biofilm Formation in Antarctic Gram-Negative Bacteria

2020 ◽  
Author(s):  
Nicolas Baeza ◽  
Elena Mercade
Keyword(s):  
Biofilm Formation ◽  
Membrane Vesicles ◽  
Metabolic Cost ◽  
Extracellular Atp ◽  
Gram Negative Bacteria ◽  
Bacterial Survival ◽  
Gram Negative ◽  
Two Factors ◽  
And Control

Abstract Biofilms offer a safe environment that favors bacterial survival; for this reason, most pathogenic and environmental bacteria live integrated in biofilm communities. The development of biofilms is complex and involves many factors, which need to be studied in order to understand bacterial behavior and control biofilm formation when necessary. We used a collection of cold-adapted Antarctic Gram-negative bacteria to study whether their ability to form biofilms is associated with a capacity to produce membrane vesicles and secrete extracellular ATP. In most of the studied strains, no correlation was found between biofilm formation and these two factors. Only Shewanella vesiculosa M7T secreted high levels of extracellular ATP, and its membrane vesicles caused a significant increase in the speed and amount of biofilm formation. In this strain, an important portion of the exogenous ATP was contained in membrane vesicles, where it was protected from apyrase treatment. These results confirm that ATP influences biofilm formation. Although the role of extracellular ATP in prokaryotes is still not well understood, the metabolic cost of its production suggests it has an important function, such as a role in biofilm formation. Thus, the liberation of extracellular ATP through membrane vesicles and its function deserve further study.

Sign in / Sign up

Export Citation Format

Share Document