Association between occupational exposure to domestic solid waste and dental caries: a cross-sectional study.

Studies have shown that domestic waste collectors are exposed to toxicants including infectious pathogens, which may be linked to their oral health conditions. This cross-sectional study evaluated the dental caries and its associated factors among domestic waste collectors. A total of 301 adult men who worked for a waste collection corporation were included; 171 men worked in direct contact with domestic solid waste and 130 did not. Sociodemographic data, working, and medical history were assessed. The decayed, missing, and filled permanent teeth (DMFT) index was examined. Logistic regression analysis was used to identify factors associated with dental status with a significance level of 5%. The overall mean DMFT score was 8.36±5.64. The mean DMFT, missing teeth (MT), and filled teeth (FT) were significantly higher in workers who did not have any direct contact with waste (p≤0.04). In the logistic analysis, DMFT ≥8 was only associated with older age (OR=8.41 [95% confidence interval (95%CI), 5.01-14.12], p<0.001). Decayed teeth (DT) ≥2 was associated with no previous oral hygiene instruction (OR=2.70 [1.50-4.81], p=0.001) and no daily dental flossing (OR=4.26 [1.92-9.43], p<0.001). MT ≥9 was associated with lower education level (OR=3.33 [1.57-7.10], p= 0.002). FT≥3 had a negative association with low income (OR= 0.42 [0.25-0.70], p<0.001) and no daily flossing (OR=0.42 [0.23-0.76], p=0.004). In conclusion, occupational exposure to domestic solid waste was not associated with poor dental status. Instead, age, education, income level, and oral hygiene were associated with dental health status. Missing teeth constituted the major component of the DMFT index. Therefore, prevention and oral rehabilitation programs are necessary to improve dental health.

Genomic Instability in Buccal Mucosal Cells of Municipal Street Sweepers as Evaluated by Micronucleus Test.

BACKGROUND/AIM: Since street sweepers comprises a group of workers who are in daily contact with rubbish, dust and air pollution, the aim of this study was to evaluate potential cytotoxic and mutagenic effects in buccal mucosa cells of street sweepers. MATERIALS AND METHODS: A total of 20 male street sweepers aged from 22 to 56 years were included in the experimental group. A total of 20 men matched by age were used as the control group. Cytotoxicity and mutagenicity were analyzed by micronucleus test in buccal mucosal cells. RESULTS: Statistically significant differences (p<0.05) in the frequency of micronuclei was detected in the street sweepers when compared to the control group. No remarkable differences were found to other metanuclear alterations indicative for cytotoxicity such as pyknosis, karyolysis, and karryorhexis when compared to matched controls. CONCLUSION: Taken together, our results indicate that street sweepers comprise an at-risk group as a result of increased mutagenicity found to buccal mucosa cells.

Curcumin-mediated anti-microbial photodynamic therapy against Candida dubliniensis biofilms.

The purpose of this study was to evaluate the effectiveness of anti-microbial photodynamic therapy (aPDT) mediated by curcumin (Cur) associated with LED light against biofilms of Candida dubliniensis, and further, investigate cellular uptake and drug penetration through the biofilms under confocal laser scanning microscopy (CLSM). Four C. dubliniensis strains were tested: three clinical isolates from HIV-positive patients and one reference strain (CBS 7987). Biofilms were treated with three Cur concentrations (20.0, 30.0, and 40.0 µM). All samples were incubated in the dark for 20 min and exposed to a 5.28 J/cm2 of LED light fluence. Additional samples of each strain were treated either with Cur or LED light only. Control samples had neither Cur nor light. After aPDT, results were read using the XTT salt reduction method. The data were statistically analyzed by two-way ANOVA followed by Games-Howell post-hoc test (α = 0.05). Confocal laser scanning microscopy was used to verify both the uptake of Cur by yeast cells and its penetration through the biofilm. The results showed that aPDT promoted significant reduction on the metabolism of the biofilm-organized cells of C. dubliniensis. Further, while Cur was rapidly taken up by C. dubliniensis cells, a longer time interval was required to allow Cur penetration into biofilm cells. Based on these results, aPDT associating LED and Cur presents promising potential on fungal control of biofilms of C. dubliniensis.

Cytogenetic Biomonitoring in Buccal Mucosal Cells from Municipal Solid Waste Collectors.

Waste collectors collect, transport, and process the garbage produced by people living in the city. Nowadays, this activity requires special attention due to the environmental impact of garbage and its potential consequences on human health. The aim of this study was to evaluate potential cytotoxic and mutagenic effects of garbage collection on waste collectors. For this purpose, a total of 47 male waste collectors aged from 24 to 53 years were included in the experimental group. A total of 30 men matched by age were used as the control group. Cytotoxicity and mutagenicity were analyzed by micronucleus test in buccal mucosaI cells. No statistically significant difference (p>0.05) in the frequency of micronuclei was detected in the waste collectors when compared to controls. Nevertheless, higher frequencies of karyolysis and pyknosis (p<0.05) were detected in buccal mucosaI cells from waste collectors when compared to matched controls. Taken together, our results indicate that waste collectors comprise an at-risk group as a result of increased cytotoxicity apparent from buccal mucosa cells.

Antimicrobial photodynamic therapy against pathogenic bacterial suspensions and biofilms using chloro-aluminum phthalocyanine encapsulated in nanoemulsions.

Antimicrobial photodynamic therapy represents an alternative method of killing resistant pathogens. Efforts have been made to develop delivery systems for hydrophobic drugs to improve the photokilling. This study evaluated the photodynamic effect of chloro-aluminum phthalocyanine (ClAlPc) encapsulated in nanoemulsions (NE) on methicillin-susceptible and methicillin-resistant Staphylococcus aureus suspensions and biofilms. Suspensions and biofilms were treated with different delivery systems containing ClAlPc. After the pre-incubation period, the drug was washed-out and irradiation was performed with LED source (660 ± 3 nm). Negative control samples were not exposed to ClAlPc or light. For the suspensions, colonies were counted (colony-forming units per milliliter (CFU/mL)). The metabolic activity of S. aureus suspensions and biofilms were evaluated by the XTT assay. The efficiency was dependent on the delivery system, superficial load and light dose. Cationic NE-ClAlPc and free-ClAlPc caused photokilling of the both strains of S. aureus. For biofilms, cationic NE-ClAlPc reduced cell metabolism by 80 and 73% of susceptible and resistant strains, respectively. Although anionic NE-ClAlPc caused a significant CFU/ml reduction for MSSA and MRSA, it was not capable of reducing MRSA biofilm metabolism. This therapy may represent an alternative treatment for eradicating resistant strains.

Effect of different pre-irradiation times on curcumin-mediated photodynamic therapy against planktonic cultures and biofilms of Candida spp.

OBJECTIVES: The aim of this study was to evaluate the effects of pre-irradiation time (PIT) on curcumin (Cur)-mediated photodynamic therapy (PDT) against planktonic and biofilm cultures of reference strains of Candida albicans, Candida glabrata and Candida dubliniensis. MATERIALS AND METHODS: Suspensions and biofilms of Candida species were maintained in contact with different concentrations of Cur for time intervals of 1, 5, 10 and 20min before irradiation and LED (light emitting diode) activation. Additional samples were treated only with Cur, without illumination, or only with light, without Cur. Control samples received neither light nor Cur. After PDT, suspensions were plated on Sabouraud Dextrose Agar, while biofilm results were obtained using the XTT-salt reduction method. Confocal Laser Scanning Microscopy (CLSM) observations were performed to supply a better understanding of Cur penetration through the biofilms after 5 and 20min of contact with the cultures. RESULTS: Different PITs showed no statistical differences in Cur-mediated PDT of Candida spp. cell suspensions. There was complete inactivation of the three Candida species with the association of 20.0µM Cur after 5, 10 and 20min of PIT. Biofilm cultures showed significant reduction in cell viability after PDT. In general, the three Candida species evaluated in this study suffered higher reductions in cell viability with the association of 40.0µM Cur and 20min of PIT. Additionally, CLSM observations showed different intensities of fluorescence emissions after 5 and 20min of incubation. CONCLUSION: Photoinactivation of planktonic cultures was not PIT-dependent. PIT-dependence of the biofilm cultures differed among the species evaluated. Also, CLSM observations confirmed the need of higher time intervals for the Cur to penetrate biofilm structures.

Photodynamic inactivation of planktonic cultures and biofilms of Candida albicans mediated by aluminum-chloride-phthalocyanine entrapped in nanoemulsions.

New drug delivery systems, such as nanoemulsions (NE), have been developed to allow the use of hydrophobic drugs on the antimicrobial photodynamic therapy. This study evaluated the photodynamic potential of aluminum-chloride-phthalocyanine (ClAlPc) entrapped in cationic and anionic NE to inactivate Candida albicans planktonic cultures and biofilm compared with free ClAlPc. Fungal suspensions were treated with different delivery systems containing ClAlPc and light emitting diode. For planktonic suspensions, colonies were counted and cell metabolism was evaluated by XTT assay. Flow cytometry evaluated cell membrane damage. For biofilms, the metabolic activity was evaluated by XTT and ClAlPc distribution through biofilms was analyzed by confocal laser scanning microscopy (CLSM). Fungal viability was dependent on the delivery system, superficial charge and light dose. Free ClAlPc caused photokilling of the yeast when combined with 100 J cm(-2). Cationic NE-ClAlPc reduced significantly both colony counts and cell metabolism (P < 0.05). In addition, cationic NE-ClAlPc and free ClAlPc caused significant damage to the cell membrane (P < 0.05). For the biofilms, cationic NE-ClAlPc reduced cell metabolism by 70%. Anionic NE-ClAlPc did not present antifungal activity. CLSM showed different accumulation on biofilms between the delivery systems. Although NE system showed a lower activity for planktonic culture, cationic NE-ClAlPc showed better results for Candida biofilms.