Department of Haematology, Hospital San Juan de Dios, San José, Costa Rica.
Clinical Laboratory, Hospital Nacional de Niños, San José, Costa Rica.
J Med Microbiol. 2024 Sep;73(9). doi: 10.1099/jmm.0.001883.
is a leading agent in community-acquired bacteraemia (CAB) and has been linked to elevated mortality rates and methicillin resistance in Costa Rica. To update and enhance previous data obtained in this country, we analysed the clinical manifestations of 54 CAB cases in a tertiary hospital and delineated the sequence types (STs), virulome, and resistome of the implicated isolates. Clinical information was retrieved from patient files. Antibiotic susceptibility profiles were obtained with disc diffusion and automated phenotypic tests. Genomic data were exploited to type the isolates and for detection of resistance and virulence genes. Primary infections predominantly manifested as bone and joint infections, followed by skin and soft tissue infections. Alarmingly, 70% of patients continued to exhibit positive haemocultures beyond 48 h of treatment modification, with nearly a quarter requiring mechanical ventilation or developing septic shock. The 30-day mortality rate reached an alarming 40%. More than 60% of the patients were found to have received suboptimal or inappropriate antibiotic treatment, and there was an alarming tendency towards the overuse of third-generation cephalosporins as empirical treatment. Laboratory tests indicated elevated creatinine levels, leukocytosis, and bandaemia within the first 24 h of hospitalization. However, most showed improvement after 48 h. The isolates were categorized into 13 STs, with a predominance of representatives from the clonal complexes CC72 (ST72), CC8 (ST8), CC5 (ST5, ST6), and CC1 (ST188). Twenty-four isolates tested positive for , with ST72 strains accounting for 20. In addition, we detected genes conferring acquired resistance to aminoglycosides, MLS antibiotics, trimethoprim/sulfamethoxazole, and mutations for fluoroquinolone resistance in the isolate collection. Genes associated with biofilm formation, capsule synthesis, and exotoxin production were prevalent, in contrast to the infrequent detection of enterotoxins or exfoliative toxin genes. Our findings broaden our understanding of infections in a largely understudied region and can enhance patient management and treatment strategies.
是社区获得性菌血症（CAB）的主要病原体，与哥斯达黎加的高死亡率和耐甲氧西林相关。为了更新和增强之前在该国获得的数据，我们分析了一家三级医院的 54 例 CAB 病例的临床表现，并描绘了相关分离株的序列型（ST）、毒力组和耐药组。临床信息从患者档案中检索。药敏谱通过圆盘扩散和自动表型试验获得。基因组数据用于分离株的分型以及耐药和毒力基因的检测。原发性感染主要表现为骨和关节感染，其次是皮肤和软组织感染。令人震惊的是，70%的患者在治疗方案改变后 48 小时仍持续出现阳性血培养，近四分之一的患者需要机械通气或发生感染性休克。30 天死亡率达到惊人的 40%。超过 60%的患者接受的抗生素治疗不理想或不适当，而且第三代头孢菌素作为经验性治疗的过度使用存在令人担忧的趋势。实验室检查显示，住院后前 24 小时内肌酐水平升高、白细胞增多和 bands 血症。然而，大多数患者在 48 小时后都有所改善。分离株分为 13 个 ST，以克隆复合体 CC72（ST72）、CC8（ST8）、CC5（ST5、ST6）和 CC1（ST188）的代表为主。24 株检测出阳性，其中 ST72 菌株占 20%。此外，我们在分离株集中检测到对氨基糖苷类、MLS 抗生素、复方磺胺甲噁唑和氟喹诺酮类耐药的获得性耐药基因，以及与生物膜形成、荚膜合成和外毒素产生相关的基因，而肠毒素或剥脱毒素基因的检出频率较低。我们的研究结果拓宽了对一个研究相对较少的地区的 感染的认识，并可以增强对患者的管理和治疗策略。
