Relação Gênero Candida e Afecções Respiratórias em Pacientes Pediátricos / Candida Gender Relationship and Respiratory Diseases in Pediatric Patients

Resumo: O objetivo foi detectar fatores de risco associados à colonização por Candida na cavidade oral de pacientes pediátricos, com diagnóstico de afecção respiratória, em Hospital Universitário em virtude de enfermidade cujo diagnóstico se enquadrasse no Capítulo X da CID-10. Método: foram coletadas amostras de saliva de 31 crianças com auxílio de swab estéril e encaminhadas para processamento no laboratório de Microbiologia da Universidade Federal de Campina Grande, campus Cajazeiras, onde foram semeadas em Agar Sabouraud Dextrose com cloranfenicol e, em seguida, foram incubadas a 35°C±2/ 24h e mais 2 dias à temperatura ambiente para verificação de crescimento de unidades formadoras de colônia por mililitro (UFC.mL-1). Resultado: A taxa de colonização oral por Candida entre os pacientes submetidos à coleta foi de 25,8%, destes, 50% pertencentes à espécie Candida albicans. Conclusão: os dados do presente estudo refletem achados amplamente divulgados, como a relação inversa entre a colonização oral e a idade do paciente e a prevalência da espécie C. albicans. Ressalta ainda a relevância da relação entre o estado imunológico do paciente e a susceptibilidade deste à colonização por tais agentes. Palavras-chave: Candida spp; infecção hospitalar; criança. Abstract: To detect risk factors associated with Candida colonization in the oral cavity of pediatric patients diagnosed with respiratory disease at a University Hospital due to a disease whose diagnosis falls under Chapter X of the ICD-10. Method: Saliva samples were collected from 31 children with the aid of a sterile swab and sent for processing in the Microbiology laboratory of the Federal University of Campina Grande, campus Cajazeiras, where they were seeded in Agar Sabouraud Dextrose with chloramphenicol and then incubated to 35°C±2/ 24h plus 2 days at room temperature to verify the growth of colony forming units per milliliter (CFU.mL-1). Results: The rate of oral colonization by Candida among patients submitted to collection was 25.8%, of which 50% belonged to the Candida albicans species. Conclusion: the data from this study reflect widely publicized findings, such as the inverse relationship between oral colonization and patient age and the prevalence of the species C. albicans. It also emphasizes the relevance of the relationship between the patient's immune status and their susceptibility to colonization by such agents. Keywords: Candida spp; hospital infection; child.

Oral Colonization by Entamoeba gingivalis and Trichomonas tenax: A PCR-Based Study in Health, Gingivitis, and Periodontitis

BackgroundThe etiology of periodontitis remains unclear, as is the place of gingivitis in its pathophysiology. A few studies linked the colonization by oral parasites (Entamoeba gingivalis and Trichomonas tenax) to periodontal disease and its severity. The aim of the current study was to estimate the prevalence of these oral parasites among healthy individuals, and in patients with gingivitis and periodontitis in Jordan.MethodsThe study was conducted during July 2019–December 2019. Samples were composed of saliva and periodontal material including dental plaque sampled with probes. The detection of oral parasites was done using conventional polymerase chain reaction (PCR).ResultsThe total number of study participants was 237: healthy (n=94), gingivitis (n=53) and periodontitis (n=90). The prevalence of E. gingivalis was 88.9% among the periodontitis patients, 84.9% among the gingivitis patients and 47.9% in the healthy group. For T. tenax, the prevalence was 25.6% among the periodontitis patients, 5.7% among the gingivitis patients and 3.2% in the heathy group. Positivity for E. gingivalis was significantly correlated with the presence of periodontal disease compared to the healthy group with odds ratio (OR) of 6.6. Periodontal disease was also correlated with lower monthly income (OR=8.2), lack of dental care (OR=4.8), and history of diabetes mellitus (OR=4.5). Colonization by E. gingivalis was correlated with gingivitis (OR=6.1) compared to the healthy group. Colonization by E. gingivalis and T. tenax were significantly correlated with periodontitis (OR=6.4 for E. gingivalis, and OR=4.7, for T. tenax) compared to the healthy group. T. tenax was only detected among individuals with generalized periodontal disease compared to its total absence among those with localized disease (19.6% vs. 0.0%; p=0.039). The co-infection rate by the two oral parasites was 11.0%.ConclusionsThe higher prevalence of human oral parasites in periodontal disease compared to healthy individuals appears to be more than a mere marker for the disease and might also be associated with disease severity and potential for progression. Thus, the dogmatic view of E. gingivalis and T. tenax as commensals needs to be re-evaluated and their contribution to pathophysiology of periodontal diseases cannot be neglected.

Candida albicans commensalism in the oral mucosa is favoured by limited virulence and metabolic adaptation .

As part of the human microbiota, the fungus Candida albicans colonizes the oral cavity and other mucosal surfaces of the human body. Commensalism is tightly controlled by complex interactions of the fungus and the host to preclude fungal elimination but also fungal overgrowth and invasion, which can result in disease. As such, defects in antifungal T cell immunity render individuals susceptible to oral thrush due to interrupted immunosurveillance of the oral mucosa. The factors that promote commensalism and ensure persistence of C. albicans in a fully immunocompetent host remain less clear. Using an experimental model of C. albicans oral colonization in mice we explored fungal determinants of commensalism in the oral cavity. Transcript profiling of the oral isolate 101 in the murine tongue tissue revealed a characteristic metabolic profile tailored to the nutrient poor conditions in the stratum corneum of the epithelium where the fungus resides. Metabolic adaptation of isolate 101 was also reflected in enhanced nutrient acquisition when grown on oral mucosa substrates. Persistent colonization of the oral mucosa by C. albicans also correlated inversely with the capacity of the fungus to induce epithelial cell damage and to elicit an inflammatory response. Here we show that these immune evasive properties of isolate 101 are explained by a strong attenuation of a number of virulence genes, including those linked to filamentation. De-repression of the hyphal program by deletion or conditional repression of NRG1 abolished the commensal behaviour of isolate 101, thereby establishing a central role of this factor in the commensal lifestyle of C. albicans in the oral niche of the host.

Oral candidiasis and the risk factors: a serial case reports

Oral candidiasis (OC) is also referred as ‘thrush’ is caused by the infections of the tongue and other oral mucosal sites and characterized by fungal overgrowth and invasion of superficial tissues. The main causative agent of 95% OC cases is Candida albicans. The prevalence of fungal oral infection was increased due to the increasing use of antibiotic and immunodeficiency condition. However, many factors have been suggested as risk factors for oral colonization. These predisposing factors are divided into local and systemic factors. We present two cases of patient with oral candidiasis that have admitted at Wangaya Regional Hospital, Denpasar, Bali, Indonesia with different precipitating factors in order to remind health provider that oral candidiasis does not only occur in people living with HIV/AIDS (PLWHA).

Host Age and Denture Wearing Jointly Contribute to Oral Colonization with Intrinsically Azole-Resistant Yeasts in the Elderly

In elderly patients, several morbidities or medical treatments predisposing for fungal infections occur at a higher frequency, leading to high mortality and morbidity in this vulnerable patient group. Often, this is linked to an innately azole-resistant yeast species such as Candida glabrata or C. krusei. Additionally, host age per se and the wearing of dentures have been determined to influence the mix of colonizing species and, consequently, the species distribution of invasive fungal infections. Since both old age and the wearing of dentures are two tightly connected parameters, it is still unclear which of them is the main contributor. Here, we performed a cross-sectional study on a cohort (N = 274) derived from three groups of healthy elderly, diseased elderly, and healthy young controls. With increasing host age, the frequency of oral colonization by a non-albicans Candida species, mainly by C. glabrata, also increased, and the wearing of dentures predisposed for colonization by C. glabrata irrespectively of host age. Physically diseased hosts, on the other hand, were more frequently orally colonized by C. albicans than by other yeasts. For both C. albicans and C. glabrata, isolates from the oral cavity did not generally display an elevated biofilm formation capacity. In conclusion, intrinsically azole-drug-resistant, non-albicans Candida yeasts are more frequent in the oral cavities of the elderly, and fungal cells not contained in biofilms may predispose for subsequent systemic infection with these organisms. This warrants further exploration of diagnostic procedures, e.g., before undergoing elective abdominal surgery or when using indwelling devices on this patient group.

Oral Colonization and Virulence Factors of Candida spp. in Babies With Cleft Palate

Objective: To examine oral colonization and virulence factors of Candida spp. in patients aged from 0 to 18 months with cleft palate (CP). Materials and Methods: Sixty babies were allocated into 3 groups: CP, CP with orthodontic plate (CPwP), and control group (Ctrl) without CP. Information on feeding habits, hygiene, and history of candidosis was collected. The presence of Candida spp. was investigated in samples of saliva. Fungal hydrophobicity, protease, esterase, phospholipase, and hemolysin were evaluated in a semiquantitative manner. Results: Positive oral isolations of Candida spp. were detected in CP (89.5%), CPwP (100%), and Ctrl (44%) groups. Candidosis was more reported in the cleft groups than in the Ctrl group ( P ≤ .023). There was a higher prevalence of Candida albicans, followed by Candida krusei, Candida tropicalis, and Candida parapsilosis in all groups. There was no uniformity of expression of virulence factors, either among different species or among different groups. Conclusion: Candida spp. colonization occurred in all groups, being superior in CPwP group. Candidosis episodes were more reported in patients from CPwP than in other groups, although candidosis was also registered in other groups. Candida albicans was the predominant species and virulence factors did not exhibit any pattern for species or groups of patients.

Manganese transport by Streptococcus sanguinis in acidic conditions and its impact on growth in vitro and in vivo

Streptococcus sanguinis is an oral commensal and an etiological agent of infective endocarditis. Previous studies have identified the SsaACB manganese transporter as essential for endocarditis virulence; however, the significance of SsaACB in the oral environment has never been examined. Here we report that a ΔssaACB mutant of strain SK36 exhibits reduced growth and manganese uptake under acidic conditions. Further studies revealed that these deficits resulted from the decreased activity of TmpA, shown in the accompanying paper to function as a ZIP-family manganese transporter. Transcriptomic analysis of fermentor-grown cultures of SK36 WT and ΔssaACB strains identified pH-dependent changes related to carbon catabolite repression in both strains, though their magnitude was generally greater in the mutant. In strain VMC66, which possesses a MntH transporter, loss of SsaACB did not significantly alter growth or cellular manganese levels under the same conditions. Interestingly, there were only modest differences between SK36 and its ΔssaACB mutant in competition with Streptococcus mutans in vitro and in a murine oral colonization model. Our results suggest that the heterogeneity of the oral environment may provide a rationale for the variety of manganese transporters found in S. sanguinis and point to strategies for enhancing the safety of oral probiotics.

Oral Candida Predicts Streptococcus mutans Emergence in Underserved US Infants

Despite the cariogenic role of Candida suggested from recent studies, oral Candida acquisition in children at high risk for early childhood caries (ECC) and its association with cariogenic bacteria Streptococcus mutans remain unclear. Although ECC disproportionately afflicts socioeconomically disadvantaged and racial-minority children, microbiological studies focusing on the underserved group are scarce. Our prospective cohort study examined the oral colonization of Candida and S. mutans among 101 infants exclusively from a low-income and racial-minority background in the first year of life. The Cox hazard proportional model was fitted to assess factors associated with the time to event of the emergence of oral Candida and S. mutans. Oral Candida colonization started as early as 1 wk among 13% of infants, increased to 40% by 2 mo, escalated to 48% by 6 mo, and remained the same level until 12 mo. S. mutans in saliva was detected among 20% infants by 12 mo. The emergence of S. mutans by year 1 was 3.5 times higher (hazard ratio [HR], 3.5; confidence interval [CI], 1.1–11.3) in infants who had early colonization of oral Candida compared to those who were free of oral Candida ( P = 0.04) and 3 times higher (HR, 3.0; CI, 1.3–6.9) among infants whose mother had more than 3 decayed teeth ( P = 0.01), even after adjusting demographics, feeding, mother’s education, and employment status. Infants’ salivary S. mutans abundance was positively correlated with infants’ Candida albicans ( P < 0.01) and Candida krusei levels ( P < 0.05). Infants’ oral colonization of C. albicans was positively associated with mother’s oral C. albicans carriage and education ( P < 0.01) but negatively associated with mother’s employment status ( P = 0.01). Future studies are warranted to examine whether oral Candida modulates the oral bacterial community as a whole to become cariogenic during the onset and progression of ECC, which could lead to developing novel ECC predictive and preventive strategies from a fungal perspective.

Epidemiological and etiological aspects of dental caries development

The infectious factor is etiological in the caries development. Early colonization of S. mutans is considered as a key point; another important caries-associated microorganism is Lactobacillus, which colonizes carious lesions later. Ecological shifts in the dental plaques against the background of weakened local immunity increase their cariogenicity and lead to the caries progression. The data obtained confirm the key importance of the oral colonization resistance in initiating dental caries and its progression. Thus, the biological status of dental plaque and the activity of cariogenic bacteria are regarded as the key mechanisms for the emergence of dental caries. Therefore, the in-depth study of oral microbial homeostasis, the factors supporting its dynamic balance, is extremely important for modern cariology that will greatly contribute to developing programs and recommendations for prevention of dental caries and its early detection in order to improve the general health of population.