Surveillance of pathogenic yeasts in hospital environments in Taiwan in 2020.

BACKGROUND: A predominate azole-resistant Candida tropicalis clade 4 genotype causing candidemia has been detected in not only Taiwan but also China, Singapore, and Australia. It can also be detected on fruit surfaces. In addition to determining distribution and drug susceptibilities of pathogenic yeasts in environments of intensive care units of 25 hospitals in Taiwan, we would also like to investigate whether the azole-resistant C. tropicalis exists in Taiwan's hospital environment. METHODS: The swabs of hospital environments were collected from August to November in 2020 and were cultured for yeasts. The yeasts were identified by rDNA sequence and the antifungal susceptibilities of those isolates were determined by the broth microdilution method. RESULTS: The average yeast-culture rate of hospitals was 9.4% (217/2299). Sinks had the highest yeast-positive culture rate (32.7%), followed by bedside tables (28.9%), floors (26.0%), water-dispenser buttons (23.8%), and TV controller/touch panels (19.0%). Of 262 identified isolates, Candida parapsilosis was the most common species, accounting for 22.1%, followed by Filobasidium uniguttulatum (18.3%), Candida albicans (9.5%), C. tropicalis (8.0%), Candida glabrata (Nakaseomyces glabratus) (6.9%), and 30 other species (35.1%). Of the 21 C. tropicalis isolates from 11 units in 9 hospitals, 15 diploid sequence types (DSTs) were identified. The two DST506 fluconazole-resistant ones belonged to clade 4. CONCLUSION: We detected not only various pathogenic yeast species but also the predominant clade 4 genotype of azole-resistant C. tropicalis. Our findings highlight and re-emphasize the importance of regular cleaning and disinfection practices.

Genetic relatedness among azole-resistant Candida tropicalis clinical strains in Taiwan from 2014 to 2018.

To monitor trends in the distribution of yeast species and the susceptibilities of these species to commonly prescribed antifungal drugs, we conduct the Taiwan Surveillance of Antimicrobial Resistance of Yeasts (TSARY) every 4 years. We found that 25 of 294 Candida tropicalis isolates from TSARY 2014 and 31 of 314 C. tropicalis isolates from TSARY 2018 were resistant to fluconazole. We determined the genetic relatedness among fluconazole-resistant C. tropicalis isolates by multilocus sequence typing (MLST). Among 174 C. tropicalis isolates, including all 56 fluconazole-resistant, all 26 susceptible-dose dependent and 92 selected fluconazole-susceptible isolates, 59 diploid sequence types (DSTs) were identified. We found that 22 of the 25 fluconazole-resistant C. tropicalis from TSARY 2014 and 29 of the 31 fluconazole-resistant C. tropicalis from TSARY 2018 were genetically related and belonged to the same cluster (clade 4). A combination of mutation and overexpression of ERG11, encoding the target of azole drugs, was the major mechanism contributing to drug resistance. Approximately two-thirds of reviewed patients infected or colonised by fluconazole-resistant C. tropicalis were azole-naïve. Furthermore, there was no evidence of patient-to-patient transmission. Because the clade 4 fluconazole-resistant C. tropicalis strain persists in Taiwan, it is important to identify the source of azole-resistant C. tropicalis to prevent the spread of this resistant strain.

Late complication of cervical disc arthroplasty: heterotopic ossification causing myelopathy after 10 years. Illustrative case.

BACKGROUND: Heterotopic ossification (HO) is a well-documented complication of cervical disc arthroplasty (CDA), although it rarely causes adverse clinical effects. Despite high-grade HO possibly limiting segmental mobility, it is reportedly seldom associated with symptoms. OBSERVATIONS: The authors report a case of a 46-year-old male patient who underwent hybrid CDA and anterior cervical discectomy and fusion for 3-level cervical disc herniation that caused myeloradiculopathy. The surgery was successful; the patient experienced nearly complete recovery postoperatively. The follow-up images, including computed tomography and magnetic resonance imaging scans, showed satisfactory decompression at the indexed levels without residual osteophytes or ossification of the posterior longitudinal ligament. However, 10 years later, the patient presented with symptomatic compressive myelopathy caused by severe HO that prompted a secondary surgery. LESSONS: Although it is generally reported in the literature that HO is clinically innocuous, in this patient, it gradually and progressively developed and caused myelopathy, requiring a secondary surgery. Symptomatic HO can be expected over time, and patients with a high risk of HO deserve long-term follow-up after CDA. Further investigations are warranted to corroborate these risk factors, including multilevel calcified disc herniation, severe spondylosis, and suboptimal placement of the device during primary CDA surgery.