Naicker Serisha D, Magobo Rindidzani E, Maphanga Tsidiso G, Firacative Carolina, van Schalkwyk Erika, Monroy-Nieto Juan, Bowers Jolene, Engelthaler David M, Shuping Liliwe, Meyer Wieland, Govender Nelesh P
Center for Healthcare-Associated Infections, Antimicrobial Resistance and Mycoses, National Institute for Communicable Diseases, A Division of the National Health Laboratory Service, Johannesburg 2192, South Africa.
School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2001, South Africa.
J Fungi (Basel). 2021 Apr 27;7(5):338. doi: 10.3390/jof7050338.
In South Africa, is the most common cause of adult meningitis. We performed multi locus sequence typing and fluconazole susceptibility testing of clinical isolates collected from 251 South African patients with cryptococcosis through national surveillance from 2005 to 2009. We examined the association between clinical characteristics of patients and genotype, and the effect of genotype on in-hospital mortality. We performed whole genome phylogenetic analysis of fifteen isolates with the molecular type VNB and tested their virulence in a model. Most isolates had the molecular type VNI (206/251, 82%), followed by VNII (25/251, 10%), VNB (15/251, 6%), and VNIV (5/251, 2%); 67 sequence types were identified. There were no differences in fluconazole minimum inhibitory concentration (MIC) values among molecular types and the majority of strains had low MIC values (MIC of 1 µg/mL and MIC of 4 µg/mL). Males were almost twice as likely of being infected with a non-VNI genotype (adjusted odds ratio [OR]: 1.65, 95% confidence interval [CI]: 0.25-10.99; = 0.61). Compared to patients infected with a VNI genotype, those with a non-VNI genotype had a 50% reduced adjusted odds of dying in hospital (95% CI: 0.03-7.57; = 0.62). However, for both these analyses, our estimates had wide confidence intervals spanning 1 with large -values. Fifteen VNB strains were not as virulent in a larval model as the H99 reference strain. A majority of these VNB strains belonged to the VNBII clade and were very closely related by phylogenetic analysis.
在南非，是成人脑膜炎最常见的病因。我们对2005年至2009年通过全国监测从251例南非隐球菌病患者中收集的临床分离株进行了多位点序列分型和氟康唑药敏试验。我们研究了患者临床特征与基因型之间的关联，以及基因型对住院死亡率的影响。我们对15株分子类型为VNB的分离株进行了全基因组系统发育分析，并在一个模型中测试了它们的毒力。大多数分离株的分子类型为VNI（206/251，82%），其次是VNII（25/251，10%）、VNB（15/251，6%）和VNIV（5/251，2%）；共鉴定出67种序列类型。各分子类型之间氟康唑最低抑菌浓度（MIC）值无差异，大多数菌株的MIC值较低（MIC为1μg/mL和MIC为4μg/mL）。男性感染非VNI基因型的可能性几乎是女性的两倍（调整优势比[OR]：1.65，95%置信区间[CI]：0.25 - 10.99；P = 0.61）。与感染VNI基因型的患者相比，感染非VNI基因型的患者住院死亡的调整优势比降低了50%（95%CI：0.03 - 7.57；P = 0.62）。然而，对于这两项分析，我们的估计值置信区间较宽，P值较大，包含1。15株VNB菌株在幼虫模型中的毒力不如H99参考菌株。这些VNB菌株中的大多数属于VNBII分支，通过系统发育分析关系非常密切。
