Orababa Oluwatosin Qawiyy, Adesida Solayide A, Peters Rebecca F, AbdulGanniyu Zainab, Olakojo Olawale, Abioye Adefunke
Department of Microbiology, Faculty of Science, University of Lagos, Akoka, Nigeria.
Present address: School of Life Sciences, Gibbet Hill campus, University of Warwick, Coventry, UK.
Access Microbiol. 2023 Oct 18;5(10). doi: 10.1099/acmi.0.000604.v5. eCollection 2023.
The genus comprises Gram-negative bacteria that are metabolically complex and versatile, often thriving in hostile settings. , the causative agent of melioidosis, is a prominent member of the genus and a clinical pathogen in tropical and sub-tropical regions. This pathogen is well known for its multidrug resistance and possible bioweapon potential. There is currently no report of the pathogen from clinical specimens in Nigeria, which might be due to misdiagnosis with phenotypic assays. This study aims to explore the accuracy of the use of phenotypic assays to diagnose in Nigeria. Two hundred and seventeen clinical samples and 28 Gram-negative clinical isolates were collected and analysed using Ashdown's selective agar and monoclonal antibody-based latex agglutination. Species-level identification was achieved using the analytical profile index (API) 20NE system. The susceptibility of the isolates to nine different antimicrobial agents was determined using the disc diffusion method. A total of seventy-four culture-positive isolates were obtained using Ashdown's selective agar. Twenty-two of these isolates were believed to be through the monoclonal antibody-based latex agglutination test and the API 20NE system subsequently identified 14 isolates as . The predominant species was with an isolation rate of 30.8 % (8/26). No isolate was distinctively identified as but five isolates were strongly suspected to be with similarity indices ranging from 81.9-91.3 %. Other bacterial species with definitive identity include sp., sp. and . The antibiotic susceptibility results revealed an overall resistance to amoxicillin-clavullanic acid of 71.4 %, to cefepime of 33.3 %, to trimethoprim-sulfamethoxazole of 38.1 %, to piperacillin-tazobactam of 33.3 %, to imipenem of 66.7 %, to doxycycline of 57.1% and to ceftazidime of 66.7 %. The highest intermediate resistance was observed for cefepime and piperacillin-tazobactam with a value of 66.7 % each, while there was no intermediate resistance for gentamicin, colistin and imipenem. Our findings, therefore, show that phenotypic assays alone are not sufficient in the diagnosis of melioidosis. Additionally, they provide robust support for present and future decisions to expand diagnostic capability for melioidosis beyond phenotypic assays in low-resource settings.
该属包含革兰氏阴性菌，这些细菌代谢复杂且具有多样性，常常在恶劣环境中生长旺盛。类鼻疽杆菌作为类鼻疽病的病原体，是该属的重要成员，也是热带和亚热带地区的临床病原体。这种病原体以其多重耐药性和潜在的生物武器可能性而闻名。目前尼日利亚尚无来自临床标本的该病原体报告，这可能是由于表型检测误诊所致。本研究旨在探讨在尼日利亚使用表型检测诊断类鼻疽杆菌的准确性。收集了217份临床样本和28株革兰氏阴性临床分离株，使用阿什当选择性琼脂和基于单克隆抗体的乳胶凝集试验进行分析。使用分析谱指数（API）20NE系统进行种水平鉴定。采用纸片扩散法测定分离株对9种不同抗菌药物的敏感性。使用阿什当选择性琼脂共获得74株培养阳性分离株。其中22株通过基于单克隆抗体的乳胶凝集试验被认为是类鼻疽杆菌，随后API 20NE系统将14株鉴定为类鼻疽杆菌。主要的类鼻疽杆菌物种是类鼻疽杆菌，分离率为30.8%（8/26）。没有分离株被明确鉴定为类鼻疽杆菌，但有5株被强烈怀疑是类鼻疽杆菌，相似性指数在81.9 - 91.3%之间。其他明确鉴定的细菌物种包括伯克霍尔德菌属、假单胞菌属和不动杆菌属。抗生素敏感性结果显示，对阿莫西林 - 克拉维酸的总体耐药率为71.4%，对头孢吡肟为33.3%，对甲氧苄啶 - 磺胺甲恶唑为38.1%，对哌拉西林 - 他唑巴坦为33.3%，对亚胺培南为66.7%，对多西环素为57.1%，对头孢他啶为66.7%。头孢吡肟和哌拉西林 - 他唑巴坦的中度耐药率最高，均为66.7%，而庆大霉素、黏菌素和亚胺培南没有中度耐药情况。因此，我们的研究结果表明，仅靠表型检测不足以诊断类鼻疽病。此外，它们为在资源匮乏地区扩大类鼻疽病诊断能力、超越表型检测的当前和未来决策提供了有力支持。
