孟曉飛 王愛梅
(濮陽市疾病預(yù)防控制中心微生物檢驗科,河南 濮陽 457000)
兒童腹瀉發(fā)病率僅次于呼吸道疾病[1],可引起兒童免疫力降低,水電解質(zhì)紊亂、發(fā)育不良等嚴(yán)重后果,嚴(yán)重危害了兒童的身體健康和生活質(zhì)量。為了找出感染性腹瀉的病原學(xué)特征,本文選取本院收治的感染性腹瀉兒童100例,探討兒童感染性腹瀉病原微生物、耐藥情況。具體內(nèi)容如下。
選取本院2018年12月至2020年12月收治的感染性腹瀉兒童100例。納入標(biāo)準(zhǔn):所有患兒均符合感染性腹瀉的診斷標(biāo)準(zhǔn)[4];本研究內(nèi)容已被所有患兒家屬知曉。排除標(biāo)準(zhǔn):不配合本研究者。本研究已經(jīng)過倫理委員會批準(zhǔn)。
1.2.1 病原微生物感染種類及其分布情況
從患兒糞便標(biāo)本提取病毒DNA或RNA后,采用ABi7500型熒光定量PCR儀[迪圖(上海)生物科技有限公司]鑒別病毒。按照《感染性腹瀉的診斷標(biāo)準(zhǔn)》《全國臨床檢驗操作規(guī)程》進(jìn)行細(xì)菌培養(yǎng)[2],將糞便標(biāo)本接種在麥康凱、木糖賴氨酸去氧膽酸鈉、高鹽甘露醇瓊脂培養(yǎng)基中,在36 ℃條件下培養(yǎng)1 d左右,將可疑菌落接種于克氏雙糖鐵瓊脂中,在36 ℃條件下培養(yǎng)8 h左右,再做血清分型鑒定。
1.2.2 病原微生物耐藥性檢測
用k-b紙片擴(kuò)散法進(jìn)行藥敏試驗,用金黃色葡萄球菌ATCC25923和大腸埃希菌ATCC25922作為質(zhì)控菌株;依照臨床和實驗室標(biāo)準(zhǔn)協(xié)會(clinical and laboratory standards institute, CLSI)制定的標(biāo)準(zhǔn)進(jìn)行結(jié)果的判定。
采用SPSS22.0軟件分析兩組數(shù)據(jù),計數(shù)資料表示為n(%),且采用χ2檢驗;P<0.05表示差異具有統(tǒng)計學(xué)意義。
100例感染性腹瀉患兒糞便共培養(yǎng)出97株病原微生物。檢出病毒中,占比比較高的依次為諾如病毒Ⅰ型、諾如病毒Ⅱ型和A組輪狀病毒;細(xì)菌中,致病性大腸埃希菌的構(gòu)成比最高,其次為沙門菌。見表1。
表1 病原微生物感染種類及其分布情況
經(jīng)檢測,致病性大腸埃希菌對新生霉素和利福平的耐藥性為100%,對四環(huán)素和氨芐西林的耐藥性為70.11%,對多粘菌素B和阿米卡星的敏感度為100%;沙門菌對新生霉素和利福平的耐藥性為100%,對氨芐西林的耐藥性為60.23,對阿莫西林和諾氟沙星的敏感度為100%;嗜水氣單胞菌、肺炎克雷伯菌等對多數(shù)藥物敏感度較高,但對新生霉素和利福平的耐藥性為100%。
兒童感染性腹瀉的主要癥狀是大便次數(shù)異常以及其性狀的改變[3],嬰幼兒的群體中感染性腹瀉的發(fā)病率較高,嚴(yán)重危害其健康。本研究結(jié)果顯示,檢出病毒中,構(gòu)成比較高的有諾如病毒Ⅰ型、諾如病毒Ⅱ型和A組輪狀病毒;腸道細(xì)菌中,致病性大腸埃希菌和沙門菌的比例較高;與周林等的研究結(jié)果相似[4]。
沙門菌作為食源性疾病的常見病原微生物,其傳播方式主要是以肉制品、家禽或者蛋白質(zhì)作為傳播媒介,因此應(yīng)對相關(guān)的傳播源加強(qiáng)管控。本研究結(jié)果顯示,大腸埃希菌和沙門菌對新生霉素和利福平的耐藥性較高,分析其原因為:臨床用藥中抗生素的濫用以及菌株質(zhì)粒的介導(dǎo)造成了致病微生物的變遷[5],從而產(chǎn)生多重耐藥等情況,因此,應(yīng)該加強(qiáng)院內(nèi)管理,減少多重耐藥菌株的風(fēng)險。在合理使用抗生素的同時,應(yīng)指導(dǎo)兒童養(yǎng)成良好的生活衛(wèi)生習(xí)慣,以此來減少兒童感染性腹瀉的風(fēng)險。
綜上所述,感染性腹瀉兒童的主要感染病原為諾如病毒、A組輪狀病毒、致病性大腸埃希菌和沙門菌,且致病性細(xì)菌具有多重耐藥性。
A COVID-19 peptide vaccine for the induction of SARS-CoV-2 T cell immunity
Jonas S Heitmann, et al.
T cell immunity is central for the control of viral infections. CoVac-1 is a peptide-based vaccine candidate, composed of SARS-CoV-2 T cell epitopes derived from various viral proteins1,2, combined with the Toll-like receptor 1/2 agonist XS15 emulsified in Montanide ISA51 VG, aiming to induce profound SARS-CoV-2 T cell immunity to combat COVID-19. We conducted a phase I open-label trial, recruiting 36 participants aged 18 to 80 years, who received one single subcutaneous CoVac-1 vaccination. The primary endpoint was safety analysed until day 56. Immunogenicity in terms of CoVac-1-induced T-cell response was analysed as main secondary endpoint until day 28 and in the follow-up until month 3. No serious adverse events and no grade 4 adverse events were observed. Expected local granuloma formation was observed in all study subjects, while systemic reactogenicity was absent or mild. SARS-CoV-2-specific T cell responses targeting multiple vaccine peptides were induced in all study participants, mediated by multifunctional T-helper 1 CD4+ and CD8+ T cells. CoVac-1-induced interferon-γ T cell responses persisted in the follow-up analyses and surpassed those detected after SARS-CoV-2 infection as well as after vaccination with approved vaccines. Furthermore, vaccine-induced T- cell responses were unaffected by current SARS-CoV-2 variants of concern (VOC). Together, CoVac-1 showed a favourable safety profile and induced broad, potent and VOC-independent T- cell responses, supporting the presently ongoing evaluation in a phase II trial for patients with B cell/antibody deficiency.
Nature. 2021 Nov 23. doi: 10.1038/s41586-021-04232-5.