Department of Microbiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
BMC Microbiol. 2021 Dec 14;21(1):343. doi: 10.1186/s12866-021-02408-7.
This study aimed to evaluate the occurrence of Streptococcus pneumoniae and Haemophilus influenzae in sputum of patients with community-acquired pneumonia (CAP) using culture and multiplex polymerase chain reaction (M-PCR) methods and to survey the antibiotic resistance patterns of aforesaid isolates.
In total, 23.9 % (n = 22/92) of sputum samples showed positive results in the culture method. S. pneumoniae and H. influenzae were isolated from 15 (16.3 %) and 7 (7.6%) samples, respectively. Using M-PCR, 44 (47.8 %) samples were positive for S. pneumoniae and H. influenzae. Of these, S. pneumoniae and H. influenzae were detected in 33 (35.8%) and 11 (11.9%) of the sputum samples, respectively. The sensitivity, specificity, and accuracy rates of PCR in detection of S. pneumoniae in comparison with culture method were 100, 76.6, and 83.6%, respectively. While, the sensitivity, specificity, and accuracy rates of PCR in detection of H. influenzae in comparison with culture method were 100, 95.3, and 95.8%, respectively. Out of 11 isolates of H. influenzae, two strains confirmed as H. influenzae type b (Hib) and 3 isolates were type f. However, 6 isolates were non-typable. The co-trimoxazole and amoxicillin/clavulanate were the less effective antibiotics against S. pneumonia and H. influenzae, respectively. Ceftriaxone with 13.3% resistance rates was the most effective antibiotic against S. pneumoniae, while, clarithromycin, ceftriaxone, and gentamicin with resistance rates of 28.6% for each one were the most effective chemicals against H. influenzae isolates.
In this study, the prevalence of S. pneumoniae was more than H. influenzae using culture and M-PCR methods. The M-PCR provided better efficiency in detecting the bacterial agents in CAP patients compared to culture method. This method can improve the early detection of pathogens contributed to CAP. The drug resistant S. pneumoniae and H. influenzae indicated the need to develop a codified monitoring program to prevent further spread of these strains.
本研究旨在使用培养和多重聚合酶链反应（M-PCR）方法评估社区获得性肺炎（CAP）患者痰中肺炎链球菌和流感嗜血杆菌的发生情况，并调查上述分离株的抗生素耐药模式。
共 23.9%（n=22/92）的痰标本培养法阳性。从 15 份（16.3%）和 7 份（7.6%）标本中分离出肺炎链球菌和流感嗜血杆菌。M-PCR 检测 44 份（47.8%）标本肺炎链球菌和流感嗜血杆菌阳性。其中，33 份（35.8%）和 11 份（11.9%）痰标本中检出肺炎链球菌和流感嗜血杆菌。PCR 法检测肺炎链球菌的敏感性、特异性和准确性分别为 100%、76.6%和 83.6%，与培养法比较。PCR 法检测流感嗜血杆菌的敏感性、特异性和准确性分别为 100%、95.3%和 95.8%，与培养法比较。11 株流感嗜血杆菌中，2 株确认为 b 型流感嗜血杆菌（Hib），3 株为 f 型。然而，6 株为非定型。复方磺胺甲噁唑和阿莫西林/克拉维酸对肺炎链球菌和流感嗜血杆菌的疗效较差。头孢曲松的耐药率为 13.3%，是治疗肺炎链球菌最有效的抗生素，而克拉霉素、头孢曲松和庆大霉素的耐药率分别为 28.6%，是治疗流感嗜血杆菌分离株最有效的药物。
本研究中，培养和 M-PCR 方法检测肺炎链球菌的患病率高于流感嗜血杆菌。与培养法相比，M-PCR 法在检测 CAP 患者的细菌病原体方面效率更高。这种方法可以提高对 CAP 患者病原体的早期检测。耐药肺炎链球菌和流感嗜血杆菌表明需要制定编码监测方案，以防止这些菌株的进一步传播。
