Low rate of nasopharyngeal carriage and high rate of ampicillin resistance for Haemophilus influenzae among healthy children younger than 5 years old in northern Taiwan.
Low rate of nasopharyngeal carriage and high rate of ampicillin resistance for Haemophilus influenzae among healthy children younger than 5 years old in northern Taiwan.
复制标题
台湾北部5岁以下健康儿童流感嗜血杆菌鼻咽携带率低、氨苄青霉素耐药率高。
DOI：
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复制
发表时间：
2008
期刊：
影响因子：
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通讯作者：
Chih
中科院分区：
文献类型：
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作者：
Sheng;W. Lo;Chen;Ying;S. Tsai;M. Chu;Chih
背景及目的
BACKGROUND AND PURPOSE
Surveillance data of colonization by Haemophilus influenzae in Taiwan are lacking. This study aimed to define the nasopharyngeal carriage rate of H. influenzae among children younger than 5 years in northern Taiwan, and to determine the antibiotic susceptibility, serotype and the clonal relationship of these isolates.
METHODS
Nasopharyngeal specimens were obtained from 511 healthy children younger than 5 years. All H. influenzae isolates were serotyped. The minimal inhibitory concentrations for various antibiotics were determined. Pulsed-field gel electrophoresis (PFGE) was used for clonal analysis.
RESULTS
Among 511 children, 269 (52.6%) had been vaccinated with at least one dose of H. influenzae type b (Hib) conjugate vaccine, 236 (46.2%) were unvaccinated and 6 (1.2%) had no vaccination records available. Twenty six H. influenzae strains were isolated. There were three Hib isolates and the others were nontypeable H. influenzae (NTHi). The carriage rate for Hib was 0.6% (3/511) and of NTHi was 5% (23/511). Three (1.27%) of the 236 unvaccinated children were carriers of Hib, whereas none of the 269 vaccinated children carried Hib. Two out of the three Hib isolates and 14 (60.9%) of 23 NTHi isolates were ampicillin-resistant. Multidrug resistance was found in 7 (26.9%) of the isolates. Among the isolates, 61.5% were beta-lactamase producers; there were no beta-lactamase-negative ampicillin-resistant isolates. The PFGE restriction patterns showed a wide diversity of genotypes.
CONCLUSIONS
There is very low nasopharyngeal carriage of Hib among children younger than 5 years in northern Taiwan. This may explain why the incidence of invasive Hib disease is also low in Taiwan. In addition, we found a high prevalence of beta-lactamase-positive ampicillin-resistant nasopharyngeal H. influenzae isolates.