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Abstract：
UNASSIGNED: A distinct strain of Klebsiella pneumoniae (K. pneumoniae) referred to as hypervirulent (hvKp) is associated with invasive infections such as pyogenic liver abscess in young and healthy individuals. In South Africa, limited information about the prevalence and virulence of this hvKp strain is available. The aim of this study was to determine the prevalence of hvKp and virulence-associated factors in K. pneumoniae isolates from one of the largest tertiary hospitals in a South African province.
UNASSIGNED: A total of 74 K. pneumoniae isolates were received from Pelonomi Tertiary Hospital National Health Laboratory Service (NHLS), Bloemfontein. Virulence-associated genes (rmpA, capsule serotype K1/K2, iroB and irp2) were screened using Polymerase Chain Reaction (PCR). The iutA (aerobactin transporter) gene was used as a primary biomarker of hvKp. The extracted DNAs were sequenced using the next-generation sequencing pipeline and the curated sequences were used for phylogeny analyses using appropriate bioinformatic tools. The virulence of hvKp vs. classical Klebsiella pneumoniae (cKp) was investigated using the Caenorhabditis elegans nematode model.
UNASSIGNED: Nine (12.2%) isolates were identified as hvKp. Moreover, hvKp was significantly (p < 0.05) more virulent in vivo in Caenorhabditis elegans relative to cKp. The virulence-associated genes [rmpA, iroB, hypermucoviscous phenotype (hmv) phenotype and capsule K1/K2] were significantly (p < 0.05) associated with hvKp. A homology search of the curated sequences revealed a high percentage of identity between 99.8 and 100% with other homologous iutA gene sequences of other hvKp in the GenBank.
UNASSIGNED: Findings from this study confirm the presence of hvKp in a large tertiary hospital in central South Africa. However, the low prevalence and mild to moderate clinical presentation of infected patients suggest a marginal threat to public health. Further studies in different settings are required to establish the true potential impact of hvKp in developing countries.
UNASSIGNED: A total of 74 K. pneumoniae isolates were received from Pelonomi Tertiary Hospital National Health Laboratory Service (NHLS), Bloemfontein. Virulence-associated genes (rmpA, capsule serotype K1/K2, iroB and irp2) were screened using Polymerase Chain Reaction (PCR). The iutA (aerobactin transporter) gene was used as a primary biomarker of hvKp. The extracted DNAs were sequenced using the next-generation sequencing pipeline and the curated sequences were used for phylogeny analyses using appropriate bioinformatic tools. The virulence of hvKp vs. classical Klebsiella pneumoniae (cKp) was investigated using the Caenorhabditis elegans nematode model.
UNASSIGNED: Nine (12.2%) isolates were identified as hvKp. Moreover, hvKp was significantly (p < 0.05) more virulent in vivo in Caenorhabditis elegans relative to cKp. The virulence-associated genes [rmpA, iroB, hypermucoviscous phenotype (hmv) phenotype and capsule K1/K2] were significantly (p < 0.05) associated with hvKp. A homology search of the curated sequences revealed a high percentage of identity between 99.8 and 100% with other homologous iutA gene sequences of other hvKp in the GenBank.
UNASSIGNED: Findings from this study confirm the presence of hvKp in a large tertiary hospital in central South Africa. However, the low prevalence and mild to moderate clinical presentation of infected patients suggest a marginal threat to public health. Further studies in different settings are required to establish the true potential impact of hvKp in developing countries.
摘要：
■肺炎克雷伯菌的一种独特菌株（K。肺炎）被称为高毒力（hvKp），与年轻和健康个体的侵袭性感染如化脓性肝脓肿有关。在南非,关于这种hvKp毒株的流行和毒力的信息有限。这项研究的目的是确定南非省最大的三级医院之一的肺炎克雷伯菌分离株中hvKp和毒力相关因子的患病率。
■总共从Pelonomi三级医院国家卫生实验室服务（NHLS）接收了74株肺炎克雷伯菌分离株，布隆方丹.毒力相关基因(rmpA，使用聚合酶链反应（PCR）筛选胶囊血清型K1/K2，iroB和irp2）。iutA(需氧菌转运蛋白)基因用作hvKp的主要生物标志物。使用下一代测序流水线对提取的DNA进行测序，并使用适当的生物信息学工具将筛选的序列用于系统发育分析。hvKp的毒力与使用秀丽隐杆线虫模型研究了经典肺炎克雷伯菌（cKp）。
■9个(12.2%)分离株被鉴定为hvKp。此外，在秀丽隐杆线虫中,hvKp相对于cKp在体内的毒性显著(p<0.05)更强。毒力相关基因[rmpA，irob,高粘膜粘性表型（hmv）表型和囊K1/K2]与hvKp显着相关（p<0.05）。对精选序列的同源性搜索显示，与GenBank中其他hvKp的其他同源iutA基因序列的同一性在99.8％至100％之间。
■这项研究的结果证实了南非中部一家大型三级医院中存在hvKp。然而,感染患者的低患病率和轻度至中度临床表现提示对公众健康的微小威胁.需要在不同环境下进行进一步研究，以确定hvKp在发展中国家的真正潜在影响。
■总共从Pelonomi三级医院国家卫生实验室服务（NHLS）接收了74株肺炎克雷伯菌分离株，布隆方丹.毒力相关基因(rmpA，使用聚合酶链反应（PCR）筛选胶囊血清型K1/K2，iroB和irp2）。iutA(需氧菌转运蛋白)基因用作hvKp的主要生物标志物。使用下一代测序流水线对提取的DNA进行测序，并使用适当的生物信息学工具将筛选的序列用于系统发育分析。hvKp的毒力与使用秀丽隐杆线虫模型研究了经典肺炎克雷伯菌（cKp）。
■9个(12.2%)分离株被鉴定为hvKp。此外，在秀丽隐杆线虫中,hvKp相对于cKp在体内的毒性显著(p<0.05)更强。毒力相关基因[rmpA，irob,高粘膜粘性表型（hmv）表型和囊K1/K2]与hvKp显着相关（p<0.05）。对精选序列的同源性搜索显示，与GenBank中其他hvKp的其他同源iutA基因序列的同一性在99.8％至100％之间。
■这项研究的结果证实了南非中部一家大型三级医院中存在hvKp。然而,感染患者的低患病率和轻度至中度临床表现提示对公众健康的微小威胁.需要在不同环境下进行进一步研究，以确定hvKp在发展中国家的真正潜在影响。
