AUTHOR=Wang Yao , Fan Xin , Wang He , Kudinha Timothy , Mei Ya-Ning , Ni Fang , Pan Yu-Hong , Gao Lan-Mei , Xu Hui , Kong Hai-Shen , Yang Qing , Wang Wei-Ping , Xi Hai-Yan , Luo Yan-Ping , Ye Li-Yan , Xiao Meng , China Hospital Invasive Fungal Surveillance Net (CHIF-NET) Study Group , Sun Zi-Yong , Chen Zhong-Jv , Xu Ying-Chun , Xiao Meng , Kang Mei , Xiao Yu-Ling , Mei Ya-Ning , Ni Fang , Pan Yu-Hong , Gao Lan-Mei , Xu Hui , Xu Hui , Liao Kang , Guo Peng-Hao , Kong Hai-Shen , Yang Qing , Wang Wei-Ping , Luo Yan-Ping , Ye Li-Yan , Yu Hua , Yin Lin , Guo Da-Wen , Cui Lan-Ying , Liu Peng-Peng , He Hong , Jin Yan , Fan Hui , Yu Yun-Song , Lin Jie , Li Ruo-Yu , Wan Zhe , Ma Ling , Du Shuai-Xian , Liu Wen-En , Li Yan-Ming , Zhou Tie-Li , Wu Qing , Hu Xin-Lan , Li Ning , Zhang Rong , Zhou Hong-Wei , Li Yi-Min , Su Dan-Hong , Zhang Qiang-Qiang , Li Li , Xia Yun , Yan Li , Hu Zhi-Dong , Yue Na , Jiang Yan , Liu Zhi-Yong , Zheng Yu-Ting , Cao Wei , Chu Yun-Zhuo , Li Fu-Shun , Liu Yun , Xu Yuan-Hong , Huang Ying , Jia Wei , Li Gang , Lv Huo-Xiang , Hu Qing-Feng , Xu Xiu-Li , Chen Xiao-Yan , Ma Xiao-Ling , Lu Huai-Wei , Yang Yin-Mei , Chen Hui-Ling , Huang Jian-Sheng , Jing Hui , San Bin , Du Yan , Liang Hong-Jie , Yang Bin , Lin Yu-Lan , Wang Shan-Mei , Ma Qiong , Zhao Hong-Mei , Liu Li-Wen , Zhang Qing , Xia Fei , Wu Jin-Ying , Yi Mao-Li , Chen Xiang-Yang , Lu Wei-Ping , Zeng Xiao-Yan , Zhang Jing , Wang Jing , Xiao Xiao-Guang , Liang Jia-Yin , Huang Fan-Hua , Zou Gui-Ling , Du Xue-Fei , Wang Xiao-Ming , Ji Xu-Feng , Liu Yong , Zhang Zhi-Jie , Ni Yu-Xing , Zhao Sheng-Yuan , Song Xiu-Lan , Xu Chun-Yan , Xu Chun-Yan , Meng Lin , Zhang Xian-Feng , Zhao Jian-Hong , Wei Hong-Lian , Xu Xue-Song , Li Weil , Wang Yu-Ping , Xu Mei , Wang Yun-Duo , Song Jing , Cui Tian-Pen , Hu Zhi-Min , Zhou Ting-Yin , Hu Hai-Qing , Xu Xiao-Min , Liang Shan-Yan , Deng Lin-Qiang , Chen Hui , Sun Xiao-Jun , Wang Hai-Bin , Kang Jian-Bang , Hou Tie-Ying , Ji Ping , Chen Na , Sui Wen-Jun , Gu Hai-Tong , Ha Xiao-Qin , Zhang Yuan-Yuan , Wang Shu-Feng , Lu Hong , Gu Yi-Hai , Hou Xuan , Tang Rong , Guo Yan-Yan , Huang Fei , Hu Long-Hua , Hu Xiao-Yan , Li Juan , Wei Lian-Hua , Liu Dan , Han Yan-Qiu , Yao Yi-Hui , Wang Jian-Sheng , Wang Jie , Li Wei , Ning Li-Ping , Song Wei-Qing , Wang Yu-Jie , Luan Liang TITLE=Continual Decline in Azole Susceptibility Rates in Candida tropicalis Over a 9-Year Period in China JOURNAL=Frontiers in Microbiology VOLUME=12 YEAR=2021 URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.702839 DOI=10.3389/fmicb.2021.702839 ISSN=1664-302X ABSTRACT=Background

There have been reports of increasing azole resistance in Candida tropicalis, especially in the Asia-Pacific region. Here we report on the epidemiology and antifungal susceptibility of C. tropicalis causing invasive candidiasis in China, from a 9-year surveillance study.

Methods

From August 2009 to July 2018, C. tropicalis isolates (n = 3702) were collected from 87 hospitals across China. Species identification was carried out by mass spectrometry or rDNA sequencing. Antifungal susceptibility was determined by Clinical and Laboratory Standards Institute disk diffusion (CHIF-NET10–14, n = 1510) or Sensititre YeastOne (CHIF-NET15–18, n = 2192) methods.

Results

Overall, 22.2% (823/3702) of the isolates were resistant to fluconazole, with 90.4% (744/823) being cross-resistant to voriconazole. In addition, 16.9 (370/2192) and 71.7% (1572/2192) of the isolates were of non-wild-type phenotype to itraconazole and posaconazole, respectively. Over the 9 years of surveillance, the fluconazole resistance rate continued to increase, rising from 5.7 (7/122) to 31.8% (236/741), while that for voriconazole was almost the same, rising from 5.7 (7/122) to 29.1% (216/741), with no significant statistical differences across the geographic regions. However, significant difference in fluconazole resistance rate was noted between isolates cultured from blood (27.2%, 489/1799) and those from non-blood (17.6%, 334/1903) specimens (P-value < 0.05), and amongst isolates collected from medical wards (28.1%, 312/1110) versus intensive care units (19.6%, 214/1092) and surgical wards (17.9%, 194/1086) (Bonferroni adjusted P-value < 0.05). Although echinocandin resistance remained low (0.8%, 18/2192) during the surveillance period, it was observed in most administrative regions, and one-third (6/18) of these isolates were simultaneously resistant to fluconazole.

Conclusion

The continual decrease in the rate of azole susceptibility among C. tropicalis strains has become a nationwide challenge in China, and the emergence of multi-drug resistance could pose further threats. These phenomena call for effective efforts in future interventions.