This research was supported by the National Natural Science Foundation of China (82201084), China Postdoctoral Science Foundation (2022M722232), Beijing Postdoctoral Research Foundation (2023-ZZ-020), Miaopu Project of Beijing Tiantan Hospital, Capital Medical University (2023MP10) and General Research Fund, Hong Kong Research Grants Council (27111820 and 17116521).

All procedures described below were approved by the Ethical Committee of Beijing Tiantan Hospital, Capital Medical University (NO. KY2023-177-01), and all patients involved in this study provided informed consent.
1. Patient inclusion and exclusion criteria
<ol>
	<li>Inclusion criteria: Classify patients as pSS patients if they fulfill the 2016 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) criteria12. Specifically, ...

Diagnosis and Strain Identification of pSS-Related Oral &lt;i&gt;Candida&lt;/i&gt;

<ol>
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A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+power+of+saliva:+Antimicrobial+and+beyond.">The power of saliva: Antimicrobial and beyond.</a> PLoS Pathog. 15 (11), e1008058 (2019).</li><li>Serrano, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Risk+factors+related+to+oral+candidiasis+in+patients+with+primary+Sj&#246;gren's+syndrome.">Risk factors related to oral candidiasis in patients with primary Sj&#246;gren's syndrome.</a> Med Oral Patol Oral Cir Bucal. 25 (5), e700-e705 (2020).</li><li>Nape&#241;as, J. J., Rouleau, T. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oral+complications+of+Sj&#246;gren's+syndrome.">Oral complications of Sj&#246;gren's syndrome.</a> Oral Maxillofac Surg Clin North Am. 26 (1), 55-62 (2014).</li><li>Mathews, S. A., Kurien, B. T., Scofield, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oral+manifestations+of+Sj&#246;gren's+syndrome.">Oral manifestations of Sj&#246;gren's syndrome.</a> J Dent Res. 87 (4), 308-318 (2008).</li><li>Leung, K. C. M., McMillan, A. S., Cheung, B. P. K., Leung, W. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sj&#246;gren's+syndrome+sufferers+have+increased+oral+yeast+levels+despite+regular+dental+care.">Sj&#246;gren's syndrome sufferers have increased oral yeast levels despite regular dental care.</a> Oral Dis. 14 (2), 163-173 (2008).</li><li>Lundstrom, I. M., Lindstrom, F. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Subjective+and+clinical+oral+symptoms+in+patients+with+primary+Sj&#246;gren's+syndrome.">Subjective and clinical oral symptoms in patients with primary Sj&#246;gren's syndrome.</a> Clin Exp Rheumatol. 13 (6), 725-731 (1995).</li><li>Alam, M. Z., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Candida+identification:+a+journey+from+conventional+to+molecular+methods+in+medical+mycology.">Candida identification: a journey from conventional to molecular methods in medical mycology.</a> World J Microbiol Biotechnol. 30 (5), 1437-1451 (2014).</li><li>Bauters, T. G., Nelis, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+chromogenic+and+fluorogenic+membrane+filtration+methods+for+detection+of+four+Candida+species.">Comparison of chromogenic and fluorogenic membrane filtration methods for detection of four Candida species.</a> J Clin Microbiol. 40 (5), 1838-1839 (2002).</li><li>Soto-Rojas, A. E., Villa, A. R., Sifuentes-Osornio, J., Alarc&#243;n-Segovia, D., Kraus, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oral+candidiasis+and+Sj&#246;gren's+syndrome.">Oral candidiasis and Sj&#246;gren's syndrome.</a> J Rheumatol. 25 (5), 911-915 (1998).</li><li>Gilchrist, J. E., Campbell, J. E., Donnelly, C. B., Peeler, J. T., Delaney, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spiral+plate+method+for+bacterial+determination.">Spiral plate method for bacterial determination.</a> Appl Microbiol. 25 (2), 244-252 (1973).</li><li>Biomerieux. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ATB+FUNGUS+3+Sensitivity+test+for+yeast-like+fungi.+REF+14204.">ATB FUNGUS 3 Sensitivity test for yeast-like fungi. REF 14204.</a> Biomerieux. , (2014).</li><li>Zhang, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+widely+used+ATB+FUNGUS+3+automated+readings+in+China+and+its+misleading+high+MICs+of+Candida+spp.+to+Azoles:+Challenges+for+developing+countries'+clinical+microbiology+labs.">The widely used ATB FUNGUS 3 automated readings in China and its misleading high MICs of Candida spp. to Azoles: Challenges for developing countries' clinical microbiology labs.</a> PLoS One. 9 (12), e114004 (2014).</li><li>Hu, L., Zhou, P., Zhao, W., Hua, H., Yan, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescence+staining+vs.+routine+KOH+smear+for+rapid+diagnosis+of+oral+candidiasis-A+diagnostic+test.">Fluorescence staining vs. routine KOH smear for rapid diagnosis of oral candidiasis-A diagnostic test.</a> Oral Dis. 26 (5), 941-947 (2020).</li><li>Samaranayake, L. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Candida+krusei+infections+and+fluconazole+therapy.">Candida krusei infections and fluconazole therapy.</a> Hong Kong Med J. 3 (3), 312-314 (1997).</li><li>Lee, Y., Puumala, E., Robbins, N., Cowen, L. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antifungal+drug+resistance:+Molecular+mechanisms+in+Candida+albicans+and+beyond.">Antifungal drug resistance: Molecular mechanisms in Candida albicans and beyond.</a> Chem Rev. 121 (6), 3390-3411 (2021).</li><li>Rihab, B., Lina, E. H., No&#233;mie, S. T., Jean, S., Marjolaine, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+experience+of+dry+mouth+and+screening+for+Sjogren's+syndrome+by+the+dentist:+patient-reported+experiences.">The experience of dry mouth and screening for Sjogren's syndrome by the dentist: patient-reported experiences.</a> BMC Oral Health. 23 (1), 1010 (2023).</li><li>Panpetch, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oral+Candida+administration+in+a+Clostridium+difficile+mouse+model+worsens+disease+severity+but+is+attenuated+by+Bifidobacterium.">Oral Candida administration in a Clostridium difficile mouse model worsens disease severity but is attenuated by Bifidobacterium.</a> PLoS One. 14 (1), e210798 (2019).</li><li>Alwaily, E. R., Abood, M. S., Al Uobody, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diagnosis+of+oral+candidiasis+in+patients+under+12+years:+18S+rRNA+as+a+marker+of+molecular+characterization+of+Candida+tropicalis.">Diagnosis of oral candidiasis in patients under 12 years: 18S rRNA as a marker of molecular characterization of Candida tropicalis.</a> Arch Razi Inst. 78 (1), 475-483 (2023).</li><li>Chen, C. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Candida+infection+as+an+early+sign+of+subsequent+Sj&#246;gren's+syndrome:+A+population-based+matched+cohort+study.">Candida infection as an early sign of subsequent Sj&#246;gren's syndrome: A population-based matched cohort study.</a> Front Med (Lausanne). 8, 796324 (2022).</li></ol>

The authors have no conflicts of interest to declare.

In the current manuscript, we provide a series of systematic, simple, and feasible methods for detecting oral Candida infections, identifying Candida strains, and testing the antifungal susceptibility of commonly used drugs in patients with pSS. 
In practical settings, not all the methods introduced in this manuscript are necessary. The oral Candida detection method(s) can be chosen based on the specific purpose. KOH smear tests and CFW staining assays, using samples...

Candidiasis is caused by Candida spp., which are opportunistic pathogens. Common strains include Candida albicans, Candida krusei, Candida glabrata, Candida parapsilosis, and Candida dubliniensis1. Opportunistic infections caused by Candida spp. include superficial Candida infections and invasive candidiasis. Invasive candidiasis mainly happens in immunocompromised individuals; for example, in patients with acquired immunodeficiency syndrome (AIDS), invasive candidiasis can significantly threaten the quality of life or even the life span2. Superficial Candida infection, such as mucocutaneous candidiasis, is more common in patients3. 
Oral candidiasis, a superficial Candida infection, is the most common human fungal infection. Candida albicans is a normal commensal of the mouth; the carriage rate of Candida spp. has been reported to range from 20% to 75% in the general population without any symptoms4. Overgrowth of Candida can lead to local discomfort in patients, such as the altered taste of sensation, burning sensation in the mouth, dysphagia due to poor nutrition, delayed recovery, and prolonged hospital stay. Long-term oral candidiasis can lead to severe invasive candidiasis, resulting in significant morbidity and mortality5. Oral candidiasis can also increase the risk of oral cancer5. Impaired salivary gland function is among the risk factors for oral candidiasis6. The initiation of infection is the adhesion of Candida to epithelial cell walls. This is followed by the proliferation and filamentation of Candida and the formation and maturation of biofilm7. Biofilms are extremely difficult to eradicate and are resistant to conventional antifungal treatment, making clinical treatment a challenge for biofilm-associated oral Candida infection7.
Primary Sj&#246;gren's syndrome (pSS) is an autoimmune disease that is characterized by dry mouth, dry eyes, and other systematic symptoms8. Dry mouth is the most frequent symptom of pSS. Saliva has important physiological antifungal functions. On the one hand, it can dilute and scour the mouth and thereafter remove organisms from the mucosa. On the other hand, saliva contains antimicrobial proteins, such as lactoferrin, sialoperoxidase, lysozyme, histidine-rich polypeptides, and specific anti-candidal antibodies, which can interact with the oral mucosa and prevent the overgrowth of Candida6. The reduced saliva flow may predispose pSS patients to oral candidiasis. An observational cross-sectional study conducted in 61 pSS patients found that 13.1% of pSS patients presented oral signs of candidiasis and colony forming unit (CFU)/mL of Candida albicans was found significantly and negatively correlated with levels of unstimulated whole saliva (UWS) and stimulated whole saliva (SWS)9.
The methods introduced in this manuscript can identify oral Candida infection based on characterized morphological attributes (e.g., the hyphae and yeast cells) in direct smear or after culturing10. The strain identification of the Candida using a Candida diagnostic agar is based on the formation of different colored colonies with varied morphology, which result from the cleavage of chromogenic substrates by species-specific enzymes11. In this manuscript, systematic methods for detecting oral Candida infection are introduced, including traditional oral Candida culture and rapid examination by potassium hydroxide (KOH) smear test and calcofluor white (CFW) staining assay10. Additionally, the antifungal susceptibility test, which can guide clinical oral Candida infection treatment, has been introduced. In actual situations, it is not necessary to perform all of the introduced methods in this manuscript; the oral Candida detection method(s) can be selected according to the purpose. The examination of oral Candida infection and the determination of Candida strains in pSS patients not only benefit the disease treatment but also help assess the characterization of oral candidiasis and the species profiles.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>0.22 &#181;m Syringe Filter</td>
			<td>MERCK</td>
			<td>SLGV004SL</td>
			<td></td>
		</tr>
		<tr>
			<td>1.5 mL Centrifuge Tube</td>
			<td>axygen</td>
			<td>MCT-150-C-S</td>
			<td></td>
		</tr>
		<tr>
			<td>10 cm Microbiological Culture Dishes</td>
			<td>Jet Bio-Filtration Co. Ltd</td>
			<td>TCD000100</td>
			<td></td>
		</tr>
		<tr>
			<td>15 mL Centrifuge Tube</td>
			<td>Jet Bio-Filtration Co., Ltd</td>
			<td>CFT011150</td>
			<td></td>
		</tr>
		<tr>
			<td>50 mL Centrifuge Tube</td>
			<td>Corning</td>
			<td>430290</td>
			<td></td>
		</tr>
		<tr>
			<td>96-well Microplates</td>
			<td>Corning</td>
			<td>3599</td>
			<td></td>
		</tr>
		<tr>
			<td>API 0.85% NaCl ampule</td>
			<td>BIOMERIEUX</td>
			<td>20070</td>
			<td></td>
		</tr>
		<tr>
			<td>Calcofluor White Stain</td>
			<td>Sigma-Aldrich</td>
			<td>18909-100ML-F</td>
			<td></td>
		</tr>
		<tr>
			<td>CHROMagar Candida</td>
			<td>CHROMagar</td>
			<td>P002860</td>
			<td>Candida diagnostic agar</td>
		</tr>
		<tr>
			<td>D(+)-Glucose Monohydrate</td>
			<td>Sinopharm Chemical Reagent Co.,Ltd</td>
			<td>10010518</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum&#160;</td>
			<td>Gibco</td>
			<td>26170035</td>
			<td></td>
		</tr>
		<tr>
			<td>McFarland Standards Kit</td>
			<td>BIOMERIEUX</td>
			<td>70900</td>
			<td></td>
		</tr>
		<tr>
			<td>Nunc precision molded loops&#160;</td>
			<td>ThermoFisher Scientific</td>
			<td>254399</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate Buffered Saline</td>
			<td>Gibco</td>
			<td>C10010500BT</td>
			<td></td>
		</tr>
		<tr>
			<td>Potassium Hydroxide</td>
			<td>Aladdin</td>
			<td>P112284-500g</td>
			<td></td>
		</tr>
		<tr>
			<td>PowerSoil DNA Isolation Kit&#160;</td>
			<td>MO BIO</td>
			<td>12888-50</td>
			<td></td>
		</tr>
		<tr>
			<td>RPMI 1640 Medium</td>
			<td>Gibco</td>
			<td>11875119</td>
			<td></td>
		</tr>
		<tr>
			<td>Sabourand&#39;s Agar Medium</td>
			<td>Solarbio</td>
			<td>S9710</td>
			<td></td>
		</tr>
		<tr>
			<td>Yeast Nitrogen Base Without Amino acids</td>
			<td>Solarbio</td>
			<td>Y8040</td>
			<td></td>
		</tr>
		<tr>
			<td>Yeast-like Fungal Susceptibility Kit (Microdilution)</td>
			<td>BIOMERIEUX</td>
			<td>14204</td>
			<td></td>
		</tr>
	</tbody>
</table>

examination of oral candida infection in primary sj&#246;gren&#39;s syndrome patients

Primary Sj&#246;gren's syndrome (pSS) is an autoimmune disease characterized by symptoms such as dry mouth, dry eyes, and other systematic symptoms. Due to the hyposalivation experienced by pSS patients, oral dysbacteriosis often occurs. A common complication of pSS is the oral Candida infection. In this article, the authors describe systematic methods that can effectively diagnose oral Candida infection and identify the Candida strains using saliva, oral mucosal swabs, or mouthwash from pSS patients. The Sabouraud's Dextrose Agar (SDA), hyphal formation assay, potassium hydroxide (KOH) smear test, and calcofluor white (CFW) staining assay are used for the diagnosis of oral Candida infection. A Candida diagnostic agar is used for the identification of Candida strains. Finally, antifungal susceptibility testing is used to determine appropriate antifungal drug treatment. This standardized method can enhance the diagnosis, treatment, and future research of pSS-related oral Candida infections. Early diagnosis, using this method, can also prevent any complications arising due to delay in receiving appropriate treatment.

Author Spotlight: Oral &lt;i&gt;Candida&lt;/i&gt; Diagnosis to Advance Clinical Treatment Regimen for pSS Patients

Examination of Oral Candida Infection in Primary Sj&#246;gren&#39;s Syndrome Patients

In this research, we present a protocol for the examination of oral candida infection in patients with primary Sjogren syndrome, which can be used for timely treatment to avoid infection-related complications. We provide a series of systematic, simple, and feasible methods for detecting oral candida infections, identifying candida strains, and testing the antifungal susceptibility of commonly-used drugs in patients with primary Sjogren's syndrome. Maybe our focus on the role of oral candida infection in the onset and the progression of primary Sjogren's syndrome pathologists in our future studies.

In this study, 12 patients with pSS were selected as representative patients and screened for oral Candida infection (Table 1). Among these patients, some patients exhibited typical oral lesions of Candida infection, including angular cheilitis (characterized by cracks at the corners of the mouth, desquamation, and hyperemia, Figure 1A), bright red edema on the gingival mucosa, yellowish-white stringy pseudo-membrane (Figure 1B...

Watch this Scientific Journal Video about Author Spotlight: Oral Candida Diagnosis to Advance Clinical Treatment Regimen for pSS Patients at JoVE.com

Here, we present a protocol for the examination of oral Candida infection in patients with primary Sj&#246;gren's syndrome, which can be used for timely treatment and, thereafter, avoiding related complications.

Primary Sj&#246;gren's syndrome (pSS) is an autoimmune disease characterized by symptoms such as dry mouth, dry eyes, and other systematic symptoms. Due ...

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Sample Collection for Diagnosis of Oral Candida in pSS Patients

To begin, select the participants based on the framed inclusion criteria. For saliva collection, instruct the patient to hold the tube with a funnel and let the saliva flow gradually into the tube along the lower lip for 15 minutes. At the end, ask the participant to spit all the remaining saliva into the tube.In case of low, unstimulated saliva flow, swab the oral mucosa in infection-suspected areas at least 10 times, and let the patient rinse their mouth with five milliliters of PBS for one minute. Then collect the mouthwash in a 50-milliliter sterile tube and put the swab into it. Add one milliliter of PBS to the collected saliva and vortex the tube for one minute.

Candida Culture and Strain Identification in Patients with pSS

Rapid Detection of Oral Candida Infection in pSS Patients Using KOH Smear Test and CFW Staining Assay

490 Views.  Capital Medical University.  Here, we present a protocol for the examination of oral Candida infection in patients with primary Sjögren's syndrome, which can be used for timely treatment and, thereafter, avoiding related complications. 

Diagnosis and Strain Identification of pSS-Related Oral Candida

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