儿童卡他莫拉菌感染的临床特征、耐药性及BRO基因特征分析

The analysis of clinical characteristics,drug resistance,and BRO gene characteristics of Moraxella catarrhalis infection in children

目的分析儿童卡他莫拉菌感染的临床特征、耐药性及BRO基因特征。方法回顾性分析2020年1月至2022年12月本院确诊为卡他莫拉菌感染儿童的临床特征,分离培养出的卡他莫拉菌耐药结果,通过PCR结合限制性内切酶分析方法对菌株进行BRO基因特征分析。结果531株卡他莫拉菌中,29 d~6个月幼儿(33.15%)和3~6岁学龄前儿童(29.76%)占比较高;秋季(9~11月)和冬季(12月至次年2月)易感染,分别占比37.48%和36.53%,差异均有统计学意义(P<0.01);531株卡他莫拉菌均检出β-内酰胺酶;氨苄西林(100%)、复方新诺明(75.14%)敏感率低,阿莫西林/克拉维酸和头孢噻肟未发现耐药;478株为BRO-1型,53株为BRO-2型;BRO-1型菌株对头孢呋辛、头孢克洛的不敏感率分别为82.64%和79.92%,高于BRO-2型的5.67%和5.67%,差异均有统计学意义(P<0.01)。结论学龄前儿童(3~6岁)易在秋冬季(9~11月和12月至次年2月)发生卡他莫拉菌感染,BRO-1型为主;BRO-1型菌株对β-内酰胺类抗生素不敏感率明显高于BRO-2型菌株。

Objective To investigate the clinical characteristics,drug resistance,and BRO gene characteristics of Moraxella catarrhalis infection in children.Methods The clinical characteristics of children diagnosed with M.catarrhalis infection in the hospital between January 2020 and December 2022 were retrospectively analyzed.The drug resistance results of the isolated and cultured M.catarrhalis strains were also examined.Furthermore,the characteristics of the BRO gene in the strains were studied using PCR combined with restriction endonuclease enzyme analysis method.Data processing and analysis were conducted using WHONET 5.6 software,and statistical analysis was performed using SPSS23.0.Results Among the 531 strains of M.catarrhalis,a higher proportion was observed in infants aged 29 days to June(33.15%)and preschool children aged>3 to 6 years old(29.76%).The occurrence of these strains was more common in autumn(September to November)and winter(December to February),accounting for 37.48%and 36.53%respectively.These differences were statistically significant(P<0.01).All 531 strains of M.catarrhalis tested positive forβ-lactamase.The insensitivity rate of sulfamethoxazole was high(75.14%),while no resistance was found to amoxicillin/clavulanic acid and cefotaxime.Among the strains,478 were identified as BRO-1 strains,while 53 were BRO-2 strains.The insensitivity rates of cefuroxime and cefaclor were higher in BRO-1 strains(82.64%and 79.92%respectively)compared to BRO-2 strains(5.67%and 5.67%).These differences were statistically significant(P<0.01).Conclusion Preschool children between the ages of 3 and 6 are more susceptible to M.catarrhalis infection during the autumn and winter months,specifically from September to November and December to February.The primary type of infection during this time is BRO-1.It is important to note that BRO-1 strains exhibit a higher resistance toβ-lactam antibiotics compared to BRO-2 strains.