Bhat Archana, Rao Suchetha S, Bhat Sevitha, Vidyalakshmi Katara, Dhanashree Biranthabail
Department of Microbiology, Kasturba Medical College, Mangalore, Manipal Academy of Higher Education, Manipal, India.
Department of Paediatrics, Kasturba Medical College, Mangalore, Manipal Academy of Higher Education, Manipal, India.
Indian J Med Microbiol. 2023 Jan-Feb;41:64-70. doi: 10.1016/j.ijmmb.2023.01.002. Epub 2023 Jan 23.
In developing countries, the aetiology of diarrhoea goes undiagnosed as only microscopy, stool culture or enzyme immunoassay are done to find the causative agent. The present study aims to detect common paediatric viral and bacterial diarrhoea pathogens by microscopy, stool culture for bacteria, and multiplex polymerase chain reaction (mPCR) for bacteria and virus detections.
Diarrheal stool samples (n = 109) received at the laboratory from paediatric patients aged one month to 18 years were included in the study. They were cultured for common bacterial pathogens and simultaneously subjected to two multiplex PCRs one for the detection of Salmonella spp., Shigella spp., Enteroinvasive E.coli and Enteropathogenic E.coli, another for the detection of adenovirus, astrovirus, rotavirus and norovirus.
Of the 109 samples cultured for bacterial aetiology, 0.9% (1/109) grew Salmonella enterica ser.Typhi and 2% (2/109) Shigella flexneri. By mPCR, 16% of samples (17/109) were positive for Shigella spp., 0.9% (1/109) for Salmonella spp., and 21% (23/109) for rotavirus. One sample (0.9%) had rotavirus and Shigella spp., which indicates mixed aetiology.
Shigella spp. and rotavirus are the prime causative agents of childhood diarrhoea in our region. The rate of detection of bacterial aetiology by culture was poor. Isolation of pathogens by conventional culture helps to know the species, serotypes and antibiotic susceptibility of the pathogens. Virus isolation is cumbersome, time-consuming, and not available for routine diagnostic use. Therefore, real-time mPCR would be a better choice for early detection of pathogens, thereby ensuring timely diagnosis, treatment, and a reduction in mortality.
在发展中国家，腹泻病因未得到诊断，因为仅通过显微镜检查、粪便培养或酶免疫测定来寻找病原体。本研究旨在通过显微镜检查、细菌粪便培养以及用于细菌和病毒检测的多重聚合酶链反应（mPCR）来检测常见的儿科病毒性和细菌性腹泻病原体。
本研究纳入了从1个月至18岁儿科患者处收集到实验室的腹泻粪便样本（n = 109）。对其进行常见细菌病原体培养，并同时进行两次多重PCR，一次用于检测沙门氏菌属、志贺氏菌属、侵袭性大肠杆菌和致病性大肠杆菌，另一次用于检测腺病毒、星状病毒、轮状病毒和诺如病毒。
在109份进行细菌病因培养的样本中，0.9%（1/109）培养出伤寒沙门氏菌血清型Typhi，2%（2/109）培养出福氏志贺氏菌。通过mPCR检测，16%的样本（17/109）志贺氏菌属呈阳性，0.9%（1/109）沙门氏菌属呈阳性，21%（23/109）轮状病毒呈阳性。1份样本（0.9%）同时感染了轮状病毒和志贺氏菌属，这表明存在混合病因。
志贺氏菌属和轮状病毒是我们地区儿童腹泻的主要病原体。通过培养检测细菌病因的检出率较低。通过传统培养分离病原体有助于了解病原体的种类、血清型和抗生素敏感性。病毒分离繁琐、耗时，且不适用于常规诊断。因此，实时mPCR对于病原体的早期检测将是更好的选择，从而确保及时诊断、治疗并降低死亡率。
