The Risk Factors and Mechanisms of Azole Resistance of Candida tropicalis Blood Isolates in Thailand: A Retrospective Cohort Study.

In recent decades, an epidemiological shift has been observed from Candida infections to non-albicans species and resistance to azoles. We investigated the associated factors and molecular mechanisms of azole-resistant blood isolates of C. tropicalis. Full-length sequencing of the ERG11 gene and quantitative real-time RT-PCR for the ERG11, MDR1, and CDR1 genes were performed. Male sex (odds ratio, 0.38), leukemia (odds ratio 3.15), and recent administration of azole (odds ratio 10.56) were associated with isolates resistant to azole. ERG11 mutations were found in 83% of resistant isolates, with A395T as the most common mutation (53%). There were no statistically significant differences in the expression of the ERG11, MDR1, and CDR1 genes between the groups resistant and susceptible to azole. The prevalence of azole-resistant isolates was higher than the usage of antifungal drugs, suggesting the possibility of environmental transmission in the healthcare setting. The unknown mechanism of the other 17% of the resistant isolates remains to be further investigated.

EQUAL Candida score, an effective tool for predicting the outcomes of Candida tropicalis candidaemia: A retrospective cohort study.

BACKGROUND: Candida tropicalis is the most common non-albicans Candida species found in Asia-Pacific countries, including Thailand. The pathogen is known for its great virulence, which causes a high case-fatality rate. Associations between case fatality and patient characteristics, infectious disease unit consultation and EQUAL Candida score were investigated. METHODS: This retrospective cohort study was conducted with 160 cases of C. tropicalis bloodstream infection between 2015 and 2019 at a single, large, tertiary centre in Thailand. Clinical characteristics, clinical presentations, patient outcomes (30-day case-fatality rate) and independent predictive factors were analysed. RESULTS: The 30-day case-fatality rate was 68.1%. The median of the EQUAL Candida score was 8. Independent factors for the prediction of case fatality were septic shock (hazard ratio, 1.84), the use of mechanical ventilation (hazard ratio, 2.03) and the EQUAL Candida score (hazard ratio, 0.75). CONCLUSIONS: The predictive factors for 30-day case fatality were septic shock, mechanical ventilation use and the EQUAL Candida score. It is recommended that the EQUAL score be considered for patients infected with C. tropicalis candidaemia to reduce the case-fatality rate.

Mild or Malign: Clinical Characteristics and Outcomes of Clostridium difficile Infection in Thailand.

Little is known about the clinical characteristics of Clostridium difficile infection (CDI) in Asia in general, and Thailand specifically, with a few studies suggesting that the disease may be milder than elsewhere. This study aimed to describe CDI in Thailand, evaluate treatment options and their outcomes, and explore possible protective factors responsible for any unique disease characteristics. From 2015 to 2018, 469 patients were included in the study. All patients had their stools tested for the tcdB gene by direct PCR and detection of toxigenic C. difficile by culture. C. difficile isolates were subjected to toxin gene profiling and ribotyping, and patient medical records were reviewed retrospectively. There were 248 and 221 patients included in CDI and control groups, respectively. The CDI group had a higher overall 30-day mortality rate than the control group (21% versus 14%, P = 0.046), but only 2 deaths (1%) were directly attributable to CDI. Metronidazole treatment was not inferior to vancomycin in this population, and vancomycin was associated with a higher 30-day mortality rate (P = 0.047). The prevalence of severe CDI and disease outcomes were not different between patients infected with A-B+ C. difficile and A+B+ C. difficile strains or between patients with and without colonization by nontoxigenic C. difficile Besides C. difficile-specific tests, neither a single laboratory result nor a combination of results was predictive of CDI. In conclusion, CDI in Thailand was relatively mild, and metronidazole remained an effective treatment option for these mild infections.