Centre for Children's Health Research, Faculty of Medicine, The University of Queensland, South Brisbane, QLD, Australia.
Statistics Unit, QIMR Berghofer Medical Research Institute, Herston, QLD, Australia.
BMC Pulm Med. 2023 Sep 1;23(1):323. doi: 10.1186/s12890-023-02611-4.
Cystic fibrosis (CF) is a life-limiting disorder that is characterised by respiratory tract inflammation that is mediated by a range of microbial pathogens. Small colony variants (SCVs) of common respiratory pathogens are being increasingly recognised in CF. The aim of this systematic review is to investigate the prevalence of SCVs, clinical characteristics and health outcomes for patients with CF, and laboratory diagnostic features of SCVs compared to non-small colony variants (NCVs) for a range of Gram-positive and Gram-negative respiratory pathogens.
A literature search was conducted (PubMed, Web of Science, Embase and Scopus) in April 2020 to identify articles of interest. Data pertaining to demographic characteristics of participants, diagnostic criteria of SCVs, SCV prevalence and impact on lung function were extracted from included studies for analysis.
Twenty-five of 673 studies were included in the systematic review. Individuals infected with SCVs of Staphylococcus aureus (S. aureus) were more likely to have had prior use of the broad-spectrum antibiotic trimethoprim sulfamethoxazole (p < 0.001), and the prevalence of SCVs in patients infected with S. aureus was estimated to be 19.3% (95% CI: 13.5% to 25.9%). Additionally, patients infected with SCVs of Gram-negative and Gram-positive pathogens were identified to have a lower forced expiratory volume in one second percentage predicted (-16.8, 95% CI: -23.2 to -10.4) than those infected by NCVs. Gram-positive SCVs were commonly described as small and non-haemolytic, grown on Mannitol salt or blood agar for 24 h at 35°C and confirmed using tube coagulase testing.
The findings of this systematic review demonstrate that SCVs of S. aureus have a high prevalence in the CF community, and that the occurrence of SCVs in Gram-positive and Gram-negative pathogens is linked to poorer respiratory function. Further investigation is necessary to determine the effect of infection by SCVs on the CF population.
囊性纤维化（CF）是一种具有生命限制的疾病，其特征是由一系列微生物病原体介导的呼吸道炎症。常见呼吸道病原体的小菌落变异体（SCV）在 CF 中越来越被认可。本系统评价的目的是调查 CF 患者 SCV 的流行率、临床特征和健康结局，以及与非小菌落变异体（NCV）相比，各种革兰氏阳性和革兰氏阴性呼吸道病原体的 SCV 的实验室诊断特征。
2020 年 4 月进行了文献检索（PubMed、Web of Science、Embase 和 Scopus），以确定感兴趣的文章。从纳入的研究中提取与参与者人口统计学特征、SCV 诊断标准、SCV 流行率以及对肺功能影响相关的数据进行分析。
在 673 项研究中，有 25 项被纳入系统评价。感染金黄色葡萄球菌（S. aureus）SCV 的个体更有可能曾使用广谱抗生素甲氧苄啶磺胺甲恶唑（p<0.001），并且 S. aureus 感染患者的 SCV 流行率估计为 19.3%（95%CI：13.5%至 25.9%）。此外，感染革兰氏阴性和革兰氏阳性病原体的 SCV 的患者的一秒用力呼气量预测值百分比（FEV1%pred）比感染 NCV 的患者低（-16.8，95%CI：-23.2 至-10.4）。革兰氏阳性 SCV 通常被描述为小而无溶血，在 35°C 下经 24 小时 Mannitol 盐或血液琼脂生长，并通过管凝固酶试验确认。
本系统评价的结果表明，金黄色葡萄球菌的 SCV 在 CF 社区中具有高流行率，并且革兰氏阳性和革兰氏阴性病原体的 SCV 的发生与呼吸功能较差有关。需要进一步研究以确定感染 SCV 对 CF 人群的影响。
