Antonio Martin, Hakeem Ishrat, Awine Timothy, Secka Ousman, Sankareh Kawsu, Nsekpong David, Lahai George, Akisanya Abiodun, Egere Uzochukwu, Enwere Godwin, Zaman Syed M A, Hill Philip C, Corrah Tumani, Cutts Felicity, Greenwood Brian M, Adegbola Richard A
Bacterial Diseases Programme, Medical Research Council Laboratories, Banjul, The Gambia.
BMC Microbiol. 2008 Nov 17;8:198. doi: 10.1186/1471-2180-8-198.
Streptococcus pneumoniae serotype 1 causes > 20% of invasive disease, among all age groups combined, in The Gambia. In contrast, it is rarely detected in carriage studies. This study compares the molecular epidemiology of S. pneumoniae serotype 1 causing invasive disease in The Gambia between 1996 and 2005 to those carried in the nasopharynx between 2004 and 2006.
A total of 127 invasive and 36 nasopharyngeal carriage serotype 1 isolates were recovered from individuals of all age groups and were analyzed by serotyping, antibiotic susceptibility testing and MLST. MLST analysis revealed 23 different sequence types (STs), 18 of which were novel. The most prevalent clone among the 163 isolates was ST618 (70.5%), followed by ST3575 (7.4%), ST2084 (2.5%) and ST612 (2.5%). A single ST (ST618), previously shown to belong to the ST217 hypervirulent clonal complex, was frequent among carriage (61.1%) and invasive (72.7%) serotype 1 isolates. ST618 causing both paediatric and adult disease peaked annually in the hot dry season and caused outbreak in 1997 and 2002.
For over a decade, isolates of ST618 have been the dominant lineage among serotype 1 carriage and disease isolates circulating in the Gambia. This lineage shows similar epidemiological features to those of the meningococcus in the African meningitis belt being able to cause outbreaks of disease.
在冈比亚，1型肺炎链球菌在所有年龄组的侵袭性疾病中占比超过20%。相比之下，在携带情况研究中很少检测到该菌。本研究比较了1996年至2005年期间在冈比亚导致侵袭性疾病的1型肺炎链球菌与2004年至2006年期间在鼻咽部携带的该菌的分子流行病学特征。
从所有年龄组的个体中总共分离出127株侵袭性和36株鼻咽部携带的1型菌株，并通过血清分型、药敏试验和多位点序列分型（MLST）进行分析。MLST分析揭示了23种不同的序列类型（STs），其中18种是新发现的。163株分离株中最常见的克隆是ST618（70.5%），其次是ST3575（7.4%）、ST2084（2.5%）和ST612（2.5%）。先前显示属于ST217高毒力克隆复合体的单一ST（ST618）在携带（61.1%）和侵袭性（72.7%）1型菌株中很常见。导致儿童和成人疾病的ST618在炎热干燥季节每年达到高峰，并在1997年和2002年引发了疫情。
十多年来，ST618分离株一直是冈比亚1型携带和疾病分离株中占主导地位的谱系。该谱系显示出与非洲脑膜炎带脑膜炎球菌相似的流行病学特征，能够引发疾病暴发。
