Molina-Mora Jose Arturo, Rojas-Varela Ángel, Martínez-Arana Christopher, Portilla-Victor Lucia, Quirós-Fallas Isaac, Sánchez-Fonseca Miryana, Araya Xavier, Cascante-Serrano Daniel, Segura-Retana Elvira, Espinoza-Solís Carlos, Uribe-Calvo María Jose, Villalobos-Alfaro Vanessa, Estrada-Murillo Heylin, Montoya-Madriz Stephanie, Madrigal Warren, Lizano Mauricio, Lozada-Alvarado Stefany, Alvarado-Rodríguez Mariela, Bolaños-Muñoz Mauricio, García-Marín Cristina, Alfaro-Camacho Javier, González-Carballo Gian Carlo, Quirós-Rojas Leana, Sánchez-Fernández Joseph, Chaves-Ulate Carolina, García-Santamaría Fernando
Centro de Investigación en Enfermedades Tropicales & Facultad de Microbiología, Universidad de Costa Rica, San José 11501-2060, Costa Rica.
Caja Costarricense del Seguro Social, San José 10105-1000, Costa Rica.
Antibiotics (Basel). 2025 Jul 30;14(8):772. doi: 10.3390/antibiotics14080772.
Carbapenem resistance is considered one of the greatest current threats to public health, particularly in the management of infections in clinical settings. Carbapenem resistance in bacteria is mainly due to mechanisms such as the production of carbapenemases (such as the imipenemase IMP, or other enzymes like VIM, NDM, and KPC), that can be detected by several laboratory tests, including immunochromatography and automated real-time PCR (qPCR). : As part of local studies to monitor carbapenem-resistant bacteria in Costa Rica, two cases were initially identified with inconsistent IMP detection results. A possible gene drop-out in the automated qPCR test was suggested based on the negative result, contrasting with the positive result by immunochromatography and whole-genome sequencing. We hypothesized that molecular testing could be optimized through the development of tailored assays to improve the detection of genes. Thus, using gene sequences from the local isolates and regional sequences in databases, primers were redesigned to extend the detection of alleles of regional relevance. : The tailored qPCR was applied to a local collection of 119 carbapenem-resistant isolates. The genomes of all 14 positive cases were sequenced, verifying the results of the custom qPCR, despite the negative results of the automated testing. : Guided by whole-genome sequencing, it was possible to extend the molecular detection of alleles circulating in Latin America using a tailored qPCR to overcome gene drop-out and false-negative results in an automated qPCR.
碳青霉烯类耐药被认为是当前对公共卫生的最大威胁之一，尤其是在临床环境中感染的管理方面。细菌中的碳青霉烯类耐药主要归因于多种机制，例如碳青霉烯酶的产生（如亚胺培南酶IMP，或其他酶如VIM、NDM和KPC），这些可以通过多种实验室检测方法检测到，包括免疫层析和自动化实时聚合酶链反应（qPCR）。作为在哥斯达黎加监测碳青霉烯类耐药细菌的本地研究的一部分，最初鉴定出两例IMP检测结果不一致的病例。基于阴性结果，推测自动化qPCR检测中可能存在基因缺失，这与免疫层析和全基因组测序的阳性结果形成对比。我们假设可以通过开发定制检测方法来优化分子检测，以提高基因检测能力。因此，利用本地分离株的基因序列和数据库中的区域序列，重新设计引物以扩大对具有区域相关性的等位基因的检测。定制的qPCR应用于本地收集的119株碳青霉烯类耐药分离株。对所有14例阳性病例的基因组进行测序，尽管自动化检测结果为阴性，但验证了定制qPCR的结果。在全基因组测序的指导下，使用定制的qPCR有可能扩大对在拉丁美洲传播的等位基因的分子检测，以克服自动化qPCR中的基因缺失和假阴性结果。
