Probiotic lactobacilli inhibit early stages of Candida albicans biofilm development by reducing their growth, cell adhesion, and filamentation

We evaluated the inhibitory effects of the probiotic Lactobacillus species on different phases of Candida albicans biofilm development. Quantification of biofilm growth and ultrastructural analyses were performed on C. albicans biofilms treated with Lactobacillus rhamnosus, Lactobacillus casei, and Lactobacillus acidophilus planktonic cell suspensions as well as their supernatants. Planktonic lactobacilli induced a significant reduction (p\ua0\ua00.05), but significantly reduced the early stages of Candida biofilm formation (p\ua

Experimental oral colonization by Candida albicans in immunosuppressed mice treated with Lactobacillus acidophilus and Lactobacillus rhamnosus

Bactérias probióticas, como Lactobacillus sp, são conhecidas como inibidoras do crescimento de microrganismos patogênicos, têm a capacidade de modificar o equilíbrio microbiológico do hospedeiro e reduzir o crescimento de patógenos, como o microoganismo Candida albicans. Para avaliar a colonização oral experimental e o seu tratamento com probióticos, 152 camundongos DBA/2 imunossuprimidos foram inoculados oralmente com uma suspensão (108 células viáveis) de C. albicans. Os animais foram divididos em 4 grupos: controle positivo (sem tratamento), tratados oralmente com nistatina, com Lactobacillus acidophilus e Lactobacillus rhamnosus. No grupo que recebeu nistatina, o tratamento foi iniciado um dia após a inoculação por Candida, já nos grupos que receberam as bactérias probióticas, os tratamentos foram iniciados 14 dias antes da inoculação. Tratamentos com nistatina e probióticos foram diários e duraram 13 dias. As avaliações foram realizadas 1, 3, 5, 7, 9, 11 e 13 dias após a inoculação inicial e feitas através de análises microbiológicas da mucosa oral dos animais. A colonização por C. albicans iniciou-se um dia após a inoculação, sendo o aumento das unidades formadoras de colônia progressivo e significante até o sétimo dia. Após este período, observou-se uma redução significativa no isolamento de leveduras. Todos os tratamentos probióticos reduziram significativamente a colonização de C. albicans na mucosa oral dos animais, comparada com a do grupo de animais não tratados. No grupo tratado com L. rhamnosus, a redução da colonização de levedura foi significativamente maior comparado ao grupo nistatina. Concluiu-se que o modelo animal DBA/2 imunossuprimidos é um bom modelo experimental para o estudo da colonização oral e o tratamento com probióticos, no presente modelo, pode ser uma alternativa eficaz para a redução da Candida na cavidade oral.To evaluate experimental oral candidiasis and the treatment using probiotics, 152 DBA/2 mice after being immunosuppressed were orally inoculated with a suspension of C. albicans containing 108 viable cells of yeast. The animals were devided into four groups: positive control (untreated), trated oraly with nystatin, with Lactobacillus acidophilus and with Lactobacillus rhamnosus. In the group that received nystatin, the treatment was initiated one day after Candida inoculation, and in the groups that received the probiotic bacteria, the treatment began fourteen days before inoculation. Treatments with nystatin and probiotics were daily and lasted 13 days. Evaluations were performed at 1, 3, 5, 7, 9, 11 and 13 days (after the initial inoculation) and made by microbiological analysis of the oral mucosa of these animals. The colonization of C. albicans in the oral mucosa animals began one day after the initial challenge and it was progressive and significant until the seventh day, when there was a significant reduction in the isolation of yeast. All treatments with probiotic bacteria significantly reduced the colonization of C. albicans in oral mucosa of the animals, compared to the untreated animal group. In group treated with L. rhamnosus the reduction of colonization of yeast was significantly higher compared to the group receiving nystatin. Based on the findings of this study we suggest that animal model DBA/2 immunosuppressed is a good model for experimental oral candidiasis and the treatment with probiotics in this model may be an effective alternative to the treatment of oral candidiasis

Experimental oral colonization by Candida albicans in immunosuppressed mice treated with Lactobacillus acidophilus and Lactobacillus rhamnosus

Bactérias probióticas, como Lactobacillus sp, são conhecidas como inibidoras do crescimento de microrganismos patogênicos, têm a capacidade de modificar o equilíbrio microbiológico do hospedeiro e reduzir o crescimento de patógenos, como o microoganismo Candida albicans. Para avaliar a colonização oral experimental e o seu tratamento com probióticos, 152 camundongos DBA/2 imunossuprimidos foram inoculados oralmente com uma suspensão (108 células viáveis) de C. albicans. Os animais foram divididos em 4 grupos: controle positivo (sem tratamento), tratados oralmente com nistatina, com Lactobacillus acidophilus e Lactobacillus rhamnosus. No grupo que recebeu nistatina, o tratamento foi iniciado um dia após a inoculação por Candida, já nos grupos que receberam as bactérias probióticas, os tratamentos foram iniciados 14 dias antes da inoculação. Tratamentos com nistatina e probióticos foram diários e duraram 13 dias. As avaliações foram realizadas 1, 3, 5, 7, 9, 11 e 13 dias após a inoculação inicial e feitas através de análises microbiológicas da mucosa oral dos animais. A colonização por C. albicans iniciou-se um dia após a inoculação, sendo o aumento das unidades formadoras de colônia progressivo e significante até o sétimo dia. Após este período, observou-se uma redução significativa no isolamento de leveduras. Todos os tratamentos probióticos reduziram significativamente a colonização de C. albicans na mucosa oral dos animais, comparada com a do grupo de animais não tratados. No grupo tratado com L. rhamnosus, a redução da colonização de levedura foi significativamente maior comparado ao grupo nistatina. Concluiu-se que o modelo animal DBA/2 imunossuprimidos é um bom modelo experimental para o estudo da colonização oral e o tratamento com probióticos, no presente modelo, pode ser uma alternativa eficaz para a redução da Candida na cavidade oral.To evaluate experimental oral candidiasis and the treatment using probiotics, 152 DBA/2 mice after being immunosuppressed were orally inoculated with a suspension of C. albicans containing 108 viable cells of yeast. The animals were devided into four groups: positive control (untreated), trated oraly with nystatin, with Lactobacillus acidophilus and with Lactobacillus rhamnosus. In the group that received nystatin, the treatment was initiated one day after Candida inoculation, and in the groups that received the probiotic bacteria, the treatment began fourteen days before inoculation. Treatments with nystatin and probiotics were daily and lasted 13 days. Evaluations were performed at 1, 3, 5, 7, 9, 11 and 13 days (after the initial inoculation) and made by microbiological analysis of the oral mucosa of these animals. The colonization of C. albicans in the oral mucosa animals began one day after the initial challenge and it was progressive and significant until the seventh day, when there was a significant reduction in the isolation of yeast. All treatments with probiotic bacteria significantly reduced the colonization of C. albicans in oral mucosa of the animals, compared to the untreated animal group. In group treated with L. rhamnosus the reduction of colonization of yeast was significantly higher compared to the group receiving nystatin. Based on the findings of this study we suggest that animal model DBA/2 immunosuppressed is a good model for experimental oral candidiasis and the treatment with probiotics in this model may be an effective alternative to the treatment of oral candidiasis

Effect of probiotic bacteria against Candida albicans: macrophages cell culture and biofilm assays

Apesar das evidências sobre o efeito de bactérias probióticas sobre Candida albicans, os mecanismos envolvidos nesta interação não estão totalmente esclarecidos. Visando contribuir com o entendimento sobre os mecanismos pelos quais bactérias probióticas interferem na colonização por C. albicans, o presente estudo testou a hipótese de que Lactobacillus probióticos interferem na resposta de macrófagos humanos induzida por C. albicans e inibem o desenvolvimento do biofilme de C. albicans. Macrófagos humanos THP-1 foram pré-tratados com Lactobacillus rhamnosus LR32, Lactobacillus casei L324m e Lactobacillus acidophilus NCFM, e desafiados com C. albicans e/ou lipopolissacarídeos (LPS) de Escherichia coli, em ensaio de co-cultura. Após incubação, foram determinados o perfil de citocinas por ELISA, a transcrição relativa do gene clec7a por RT-qPCR. Biofilmes de C. albicans ATCC SC5314 e 75 (isolado clínico) em fase de adesão inicial, colonização inicial e maturação foram tratados com suspensão de Lactobacillus probióticos. Além disso, os biofilmes de C. albicans foram tratados com meio condicionado com L. rhamnosus após diferentes períodos experimentais. O efeito dos probióticos foi avaliado por contagem de células de C. albicans viáveis e avaliação da morfologia celular por microscopia confocal e eletrônica de varredura. O pré-tratamento com bactérias probióticas promoveu alteração no perfil de citocinas produzidas por macrófagos desafiados com LPS e C. albicans, induzindo um aumento nos níveis de IL-10 e redução de IL-12 (p0,05), mas promoveu redução significativa do número de UFC de C. albicans quando utilizado nos estágios iniciais da formação do biofilme (p0.05), but significantly reduced the early stages of Candida biofilm formation (p<0.01). Microscopic analyses revealed that L. rhamnosus suspensions reduced Candida hyphal differentiation, leading to a predominance of budding growth. All lactobacilli negatively impacted C. albicans yeast-to-hyphae differentiation and biofilm formation. The inhibitory effects of Lactobacillus on C. albicans involved both cell-cell interactions and secretion of exometabolites. To conclude, the probiotic lactobacilli reduce inflammation by impairing the recognition of C. albicans by macrophages and altering the production of proinflammatory cytokines. It was also clarified, for the first time, the mechanics of how the Lactobacillus species antagonize C. albicans colonization, particularly in the critical, early colonization phase of the yeast. Taken all together, our data elucidated the inhibitory mechanisms of lactobacilli that define their probiotic candicidal activity, supporting the use of these probiotics as a supplemental therapy against mucosal infections by C. albicans

Recrudescence of Scarlet Fever and Its Implications for Dental Professionals

A significant increase in the incidence of scarlet fever, mainly in Europe, has been noted during the COVID-19 postpandemic period. Scarlet fever is caused by a pyrogenic exotoxin-producing streptococcus—Streptococcus pyogenes—responsible for more than 500,000 deaths annually worldwide. Superantigens (SAgs) secreted by this Group A streptococcus (GAS) usually overstimulate the human immune system, causing an amplified hypersensitivity reaction leading to initial symptoms such as sore throat, high fever, and a sandpaper-like skin rash. There could be concurrent oral manifestations known as “strawberry tongue” or “raspberry tongue,” which may be first noted by oral health professionals. The early diagnosis and treatment of this disease is critical to obviate the development of local and systemic sequelae such as acute rheumatic fever, endocarditis, and glomerulonephritis. Antibiotics should be prescribed early to mitigate its duration, sequelae, and community spread. Dental practitioners should be aware of the early symptoms of scarlet fever for infection detection, emergency patient management, and appropriate referral. This concise review outlines the prevalence, pathogenicity, oral and systemic manifestations, as well as the dental implications of scarlet fever

Probiotic Bifidobacteria in Managing Periodontal Disease: A Systematic Review

ABSTRACT: Although various probiotic organisms have been evaluated for their utility in the management of periodontitis, their strain-specific mechanisms of action are still unclear. We aimed to systematically review the effect of bifidobacterial probiotics on periodontopathogens and host immune responses in periodontal diseases. An electronic search of articles published until June 2022 in Medline, PubMed, Web of Science, and Cochrane Library databases was performed. Randomised controlled trials (RCTs) and in vitro and animal studies were assessed, and the data regarding antimicrobial properties, immunomodulation, and clinical outcomes were analysed. A total of 304 studies were screened, but only 3 RCTs and 6 animal and in vitro studies met the inclusion criteria. The use of different strains of bifidobacteria led to (1) a reduction of key players of the red complex periodontopathogens; (2) reduced levels of pro-inflammatory cytokines (eg, interleukin [IL]1-β and IL-8) and higher levels of anti-inflammatory cytokines (IL-10); (3) enhanced levels of osteoprotegerin and reduced levels of receptor activator of nuclear factor kappa-B ligand; and (4) a reduction of the dental plaque, bleeding on probing, alveolar bone loss, and clinical attachment loss. Bifidobacterial probiotic adjuvant supplementation, especially with Bifidobacterium animalis subspecies lactis, appears to help improve clinical periodontal parameters and develop a healthy plaque microbiome through microbiological and immunomodulatory pathways. Further human and animal studies are warranted prior to the therapeutic use of bifidobacteria in the routine management of periodontal infections

Comparison of heat production and bone architecture changes in the implant site preparation with compressive osteotomes, osseodensification technique, piezoelectric devices, and standard drills: an ex vivo study on porcine ribs

This study aimed at investigating differences in heat generation and bone architecture following four different implant site preparation techniques: compressive osteotomes, conventional drills, osseodensification (OD mode with osseodensification drills), and piezoelectric systems. Porcine rib bones were used as a model for implant surgery. Thermocouples were employed to measure temperature changes, and micro-CT to assess the bone architecture. The primary stability and insertion torque values of the implants placed in the differently prepared sites were assessed. The temperature changes were higher with Piezo. The average primary stability using the ISQ scale was the greatest for drills (76.17 +/- 0.90) and the lowest for osteotomes (71.50 +/- 11.09). Insertion torque was significantly higher with the osseodensification method (71.67 +/- 7.99 Ncm) in comparison to drills, osteotomes, and piezo. Osteotomes showed the highest bone to implant contact percentage (39.83 +/- 3.14%) and average trabecular number (2.02 +/- 0.21 per mm), while drills exhibited the lowest (30.73 +/- 1.65%; 1.37 +/- 0.34 per mm). Total implant site bone volume was the highest with osseodensification (37.26 +/- 4.13mm(3)) and the lowest for osteotomes (33.84 +/- 3.84mm(3)). Statistical analysis showed a high primary stability and decrease in temperature during implant site preparation with osseodensification technique. The results support the use of osseodensification technique for implant site preparation

Mucormycosis of the Mandible and Tongue: A Systematic Scoping Review

ABSTRACT: Aim: Mucormycosis is a rare human infection associated with Mucorales, a group of filamentous moulds found in different environmental niches. Its oral manifestations may occur in the mandible and tongue despite being rare. We aimed to systematically review the data on clinical manifestations, risk factors, diagnostic approaches, treatment options, and outcomes of mandibular and tongue mucormycosis. Methods: An electronic search of articles published between January 1975 and November 2022 in PubMed, Web of Science, and EMBASE databases was performed. A total of 22 articles met the inclusion criteria and reported 27 cases of oral mucormycosis in total. Results: Fourteen patients had mandibular mucormycosis signs unrelated to COVID-19 infection, 6 had SARS-CoV-2–related mandibular mucormycosis, and 6 had manifestations in the tongue. All published case reports during the COVID-19 pandemic were from India. Patient ages ranged from 4 months old to 82 years, and most patients had important comorbidities, such as blood dyscrasias related to immune deficiency and uncontrolled type 2 diabetes mellitus. The signs and symptoms of mandibular and tongue mucormycosis varied from dental pain, loose teeth, and nonhealing sockets to dysphagia and paraesthesia of the lip. Some patients also reported trismus, draining sinus tract, and facial pain. The diagnosis of oral mucormycosis was based on a combination of clinical, radiographic, and histopathologic findings by demonstrating fungal hyphae in tissue specimens. In most cases, mucormycosis was managed with systemic amphotericin B, strict glycaemic control, and aggressive surgical debridement of infected tissue, minimising the progression of the fungal infection and thus improving the survival rate. In some cases, combined antifungal therapy, antibiotic therapy, and chlorhexidine mouthwashes were used successfully. Conclusions: Recognition of the signs and symptoms by oral care providers is pertinent for the early diagnosis and treatment of tongue and mandibular mucormycosis, and providers should be aware of the possibility of this opportunistic fungal infection in patients with COVID-19. A multidisciplinary approach is recommended for the management of this lethal infection