Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.
Department of Biomedical Sciences, School of Health Sciences, University of Zambia, Lusaka, Zambia.
Pediatr Pulmonol. 2022 Dec;57(12):3084-3093. doi: 10.1002/ppul.26138. Epub 2022 Sep 15.
Moraxella catarrhalis is one of the bacterial pathogens associated with childhood pneumonia, but its clinical importance is not clearly defined.
This study aimed to investigate the microbiologic and virulence characteristics of M. catarrhalis isolates obtained from children with pneumonia in Lusaka, Zambia.
This retrospective, cross-sectional study analyzed 91 M. catarrhalis isolates from induced sputum samples of children less than 5 years of age with pneumonia enrolled in the Pneumonia Etiology Research for Child Health study in Lusaka, Zambia between 2011 and 2014. Bacteria identification and virulence genes detection were performed by PCR and DNA sequencing, while antimicrobial susceptibility testing was determined by the Kirby-Bauer method.
All the M. catarrhalis isolates were obtained from good-quality sputum samples and were the predominant bacteria. These isolates harbored virulence genes copB (100%), ompE (69.2%), ompCD (71.4%), uspA1 (92.3%), and uspA2 (69.2%) and were all β-lactamase producers. They showed resistance to ampicillin (100%), amoxicillin (100%), trimethoprim-sulfamethoxazole (92.3%), ciprofloxacin (46.2%), chloramphenicol (45.1%), erythromycin (36.3%), tetracycline (25.3%), cefuroxime (11.0%), and amoxicillin-clavulanate (2.2%), with 71.4% displaying multi-drug resistant phenotype but all susceptible to imipenem (100%).
This study showed that M. catarrhalis isolates were the predominant or only bacterial isolates from the sputum samples analyzed. The findings provide supportive evidence for the pathogenic potential role of this bacterium in pediatric pneumonia. High multidrug resistance was also observed amongst the isolates, which can result in affected patients not responding to standard treatment, leading to prolonged illness, increased healthcare costs, and risk of death.
卡他莫拉菌是与儿童肺炎相关的细菌病原体之一，但它的临床重要性尚不清楚。
本研究旨在调查赞比亚卢萨卡儿童肺炎患者痰液中分离的卡他莫拉菌的微生物学和毒力特征。
本回顾性、横断面研究分析了 2011 年至 2014 年期间在赞比亚卢萨卡参加儿童肺炎病因研究的 91 例小于 5 岁肺炎患儿诱导痰样本中分离的 91 株卡他莫拉菌。通过 PCR 和 DNA 测序进行细菌鉴定和毒力基因检测，通过 Kirby-Bauer 法进行抗菌药物敏感性试验。
所有卡他莫拉菌分离株均来自高质量的痰液样本，且为主要分离菌。这些分离株携带 copB（100%）、ompE（69.2%）、ompCD（71.4%）、uspA1（92.3%）和 uspA2（69.2%）等毒力基因，均为β-内酰胺酶产生菌。它们对氨苄西林（100%）、阿莫西林（100%）、复方磺胺甲噁唑（92.3%）、环丙沙星（46.2%）、氯霉素（45.1%）、红霉素（36.3%）、四环素（25.3%）、头孢呋辛（11.0%）和阿莫西林克拉维酸（2.2%）耐药，71.4%的分离株表现出多药耐药表型，但均对亚胺培南（100%）敏感。
本研究表明，卡他莫拉菌分离株是分析痰液样本中主要或唯一的细菌分离株。这些发现为该细菌在儿童肺炎中的致病作用提供了支持性证据。同时还观察到分离株存在高度的多重耐药性，这可能导致受感染的患者对标准治疗无反应，导致疾病延长、医疗费用增加和死亡风险增加。
