Evidence of cross-contamination of waste workers and transmission of antimicrobial resistance genes by coagulase-negative Staphylococcus isolated from dental solid waste: an intriguing study.

The aim of this study was to phenotypically and genotypically identify coagulase-negative Staphylococcus (CoNS) recovered from the nostrils of waste workers and from dental waste; 135 strains were recovered and S. epidermidis was the prevailing species. Genetic similarity (100%) was observed between the two S. epidermidis isolated from different employees on the same shift and 85% similarity between the S. epidermidis recovered from an employee's nostril and from waste. The mecA gene was found in 20 CoNS, and 20% were also found to possess the vanA gene. The blaZ gene was detected in 46.7%, and the icaA (34.8%), B and C genes (11.8% each). Our findings emphasized the biological risk to which waste workers are exposed and unprecedently confirms that it was possible to recover genetically identical bacterial species from waste and from workers' nostrils. It is important to highlight that this risk is raised by the detection of relevant antimicrobial resistance genes. The results also suggest that effective measures to correctly manage waste and promote the rational use of antimicrobials should be adopted.

Knowledge, behaviour and microbial load of workers handling dental solid waste in a public health service in Brazil.

Healthcare wastes are those generated inside healthcare services, including dental clinics. Workers coming into close proximity to hazardous healthcare waste are potentially at risk. In an attempt to assess the knowledge and attitudes of workers dealing with infectious waste, a questionnaire was administered. The biological risk was investigated by evaluating the microbial load and screening some clinically relevant micro-organisms in the nasal mucosa, hands and coats of these workers. The results showed that 66.6% of the study population had incomplete primary education. Only two workers have had their blood tested to confirm anti-HBs levels. Microbial load evaluation on hand surfaces of morning workers showed statistically significant lower microbial loads after the workday when compared with the beginning of the work period. It is important to highlight that some clinically relevant bacteria, such as Pseudomonas aeruginosa and Klebsiella pneumoniae were isolated from worker's hands. This study revealed the need for more training programmes regarding awareness of safe waste disposal protocols and also the necessity of discussing vaccination and its implications. Data regarding microbial loads of the worker's hands, mostly at the beginning of the workday when handwashing is recommended worldwide, emphasise that hygiene measures should receive more attention during training exercises.

Composition analysis of dental solid waste in Brazil.

When developing proper waste management strategies, it is essential to characterize the volume and composition of solid waste. The aim of this work was to evaluate the composition of dental waste produced by three dental health services in Belo Horizonte, Minas Gerais State, Brazil. Two universities, one public and one private, and one public dental health service were selected. Waste collection took place from March to November 2007. During this period, three samples were collected from each dental health service. The total amount of dental waste produced in one day of dental work was manually separated into three categories: infectious and potentially infectious waste, accounting for 24.3% of the total waste; non-infectious waste, accounting for 48.1%; and domestic-type waste, accounting for 27.6% (percentages are for mean weights of solid waste). Our results showed that most of the waste considered as biomedical may be misclassified, consequently making the infectious waste amount appear much larger. In addition, our results suggest that the best waste minimization method is recycling, and they help to define an appropriate waste management system in all three of the dental health services involved in this study.

Investigating cross-contamination by yeast strains from dental solid waste to waste-handling workers by DNA sequencing.

Trying to widen the discussion on the risks associated with dental waste, this study proposed to investigate and genetically compare yeast isolates recovered from dental solid waste and waste workers. Three samples were collected from workers' hands, nasal mucosa, and professional clothing (days 0, 30, and 180), and two from dental waste (days 0 and 180). Slide culture, microscopy, antifungal drug susceptibility, intersimple sequence repeat analysis, and amplification and sequencing of internal transcribed spacer regions were performed. Yeast strains were recovered from all waste workers' sites, including professional clothes, and from waste. Antifungal susceptibility testing demonstrated that some yeast recovered from employees and waste exhibited nonsusceptible profiles. The dendrogram demonstrated the presence of three major clusters based on similarity matrix and UPGMA grouping method. Two branches displayed 100% similarity: three strains of Candida guilliermondii isolated from different employees, working in opposite work shifts, and from diverse sites grouped in one part of branch 1 and cluster 3 that included two samples of Candida albicans recovered from waste and the hand of one waste worker. The results suggested the possibility of cross-contamination from dental waste to waste workers and reinforce the need of training programs focused on better waste management routines.

Conhecimento e adoção de estratégias ecológicas na graduação em Odontologia / Knowledge and adoption of ecological strategies among undergraduate Dentistry students

O objetivo do estudo foi avaliar o conhecimento e a adoção de estratégias da Odontologia sustentável pelos estudantes de uma instituição de ensino superior privada de Belo Horizonte. A amostra foi composta por acadêmicos matriculados no 4º ao 9º período no ano de 2018 (n=287). Os dados foram coletados por meio de questionário autoaplicável em língua portuguesa, tabulados e analisados por meio de análise descritiva. Observou-se que cerca de um terço dos participantes (93, 32,39%) adotam as estratégias ecológicas que podem ser implementadas nas práticas odontológicas diárias. Aproximadamente a metade dos estudantes (152, 53,0%) relataram que pensam às vezes nas questões ambientais e de sustentabilidade e 252 (87,8%) responderam que nunca ouviram falar sobre Odontologia Verde. No entanto, 268 (93,4%) demonstraram interesse em conhecê-la e 230 estudantes (80,1%) consideraram importante a implementação de programas de educação ambiental no currículo dos cursos de Odontologia. Grande parte dos estudantes desconhece a Odontologia Verde e não adota condutas que refletem preocupação com as questões ambientais. Apenas uma parcela dos entrevistados utiliza estratégias ecológicas na sua rotina clínica, mas não necessariamente em seus hábitos cotidianos. A inserção da educação ambiental nas universidades faz-se urgente e foi apoiada pelos estudantes do presente estudo (AU).

The aim of this study was to evaluate the knowledge and adoption of sustainable Dentistry strategies by students of a private higher education institution in Belo Horizonte. The sample consisted of students enrolled in the 4th to 9th period in 2018 (n = 287). Data were collected through a self-administered Portuguese language questionnaire, tabulated and analyzed through descriptive analysis. About one third of the participants (93, 32.39%) adopt the ecological strategies that can be implemented in daily dental practices. Approximately half of the students (152, 53.0%) reported that they sometimes think about environmental and sustainability issues and 252 (87.8%) answered that they had never heard of Green Dentistry. However, 268 (93.4%) showed interest in getting to know it and 230 students (80.1%) considered it important to implement environmental education programs in the curriculum of Dentistry courses. Most students are unaware of Green Dentistry and do not adopt conducts that reflect concern about environmental issues. Only a portion of respondents use ecological strategies in their clinical routine, but not necessarily in their daily habits. The insertion of environmental education in universities is urgent and was supported by the students of this study (AU).

Count, identification and antimicrobial susceptibility of bacteria recovered from dental solid waste in Brazil.

In Brazil, few studies on microbial content of dental solid waste and its antibiotic susceptibility are available. An effort has been made through this study to evaluate the hazardous status of dental solid waste, keeping in mind its possible role in cross-infection chain. Six samples of solid waste were collected at different times and seasons from three dental health services. The microbial content was evaluated in different culture media and atmospheric conditions, and the isolates were submitted to antibiotic susceptibility testing. A total of 766 bacterial strains were isolated and identified during the study period. Gram-positive cocci were the most frequent morphotype isolated (48.0%), followed by Gram-negative rods (46.2%), Gram-positive rods (5.0%), Gram-negative-cocci (0.4%), and Gram-positive coccobacillus (0.1%). Only two anaerobic bacteria were isolated (0.3%). The most frequently isolated species was Staphylococcus epidermidis (29.9%), followed by Stenotrophomonas maltophilia (8.2%), and Enterococcus faecalis (6.7%). High resistance rate to ampicillin was observed among Gram-negative rods (59.4%) and Gram-positive cocci (44.4%). For Gram-negative rods, high resistance was also noted to aztreonam (47.7%), cefotaxime (47.4%), ceftriaxone and cefazolin (43.7%), and ticarcillin-clavulanic acid (38.2%). Against Gram-positive cocci penicillin exhibit a higher resistance rate (45.0%), followed by ampicillin, erythromycin (27.2%), and tetracycline (22.0%). The present study demonstrated that several pathogenic bacteria are present in dental solid waste and can survive after 48 h from the waste generation time and harbor resistance profiles against several clinical recommended antibiotics.

Biological exposure-related injuries in dental health-care workers / Prevalência de acidentes ocupacionais nos profissionais da Odontologia envolvendo instrumentos perfurocortantes

Objective: This study was conducted during a 13-year period to analyze the number and profile of biological exposure-related injuries among dentalhealth-care workers in a Public Health Service in Belo Horizonte, Brazil.Methods: All occupational accidents involving dental staff, dentists, dental assistants, dental technicians (n=215), and those involved in processingenvironmental surfaces and waste collection (n=12), and body fluids associated with sharp instruments were recorded. Our data were collected from January 1999 to May 2011. Results: A total of 41 exposures were reported. The majority of biological exposures occurred in females aged 26 to 35 years. The most frequently involved devices were syringe needles and the most frequently involved body fluid was blood. Despite the existence of an institutional guideline, it was observed that 12.2% of health-care workers did not follow the post-exposure recommendations. Additionally, 14.6% of the dental care workers did not receive hepatitis B vaccination. Conclusion: Our results suggest that it is important to provide more safety training programs and information about occupational risks to all dental healthcare personnel.

Objetivo: Para conhecer o número e o perfil de acidentes ocupacionais envolvendo material perfurocortante, entre os profissionais da Odontologia de um Serviço de Saúde Pública, foram levantados dados no período de 1999 a 2011. Métodos: Foram levantados os acidentes ocupacionais em uma instituição de assistência à saúde odontológica, pública e autárquica, na cidade de Belo Horizonte, em Minas Gerais. O quadro clínico é composto de 215 profissionais de saúde que oferecem consultas em diversas especialidades e 12 profissionais na equipe de serviços gerais. Foram colhidos dados de todos os acidentes com material perfurocortante, envolvendo material biológico, e que ocorreram no período de janeiro de 1999 a maio de 2011. Resultados: Foi registrado um total de 41 (quarenta e um) acidentes e os profissionais que mais se acidentaram pertenciam ao gênero feminino e possuíam idade entre 26 e 35 anos. Um percentual de acidentados ainda não havia se vacinado contra o vírus da Hepatite B. O sangue foi a secreção mais frequentemente envolvida nos acidentes e as agulhas corresponderam à maioria das injúrias. Apesar da existência de um protocolo institucional, 12,2% dos profissionais acidentados não realizaram acompanhamento completo pós-exposição. Conclusão: Os dados suscitam a necessidade de um maior conhecimento da equipe da Odontologia a respeito dos riscos e da prevenção dos acidentes ocupacionais envolvendo material perfurocortante e também do protocolo institucional.