Vasanthaiah Shruthi, Takey Pritibala, Selvam Prasanna Kumar, Mohan Supraja, Kiran Ravi, Roohi Shabnam, Vasudevan Karthick
Manipal Academy of Higher Education (MAHE), Manipal, India.
Institute of Bioinformatics, International Technology Park, Bangalore, India.
Infection. 2025 May 12. doi: 10.1007/s15010-025-02546-4.
Carbapenem resistance in Enterobacterales is a growing public health concern, primarily driven by carbapenemase enzymes such as OXA-48, VIM, NDM, and IMP. Among these, New Delhi Metallo-β-lactamase (NDM) has disseminated widely across various Enterobacterales species, including Salmonella Typhi, though reports remain rare.
We report an 11-year-old boy from Bangalore with a 10-day history of high-grade fever, chills, rigors, and cough. Laboratory investigations revealed elevated CRP, normal CBC, and microcytic hypochromic anemia. A respiratory panel detected Human Rhinovirus/ Enterovirus. Blood cultures grew non-lactose fermenting gram-negative bacilli, identified as Salmonella spp. via Vitek ID/AST. The isolate exhibited resistance to ampicillin, ciprofloxacin, ceftriaxone, tetracycline, and meropenem but remained susceptible to azithromycin, chloramphenicol, and Co-trimoxazole. Serotyping confirmed the serotype as Salmonella Typhi. Whole-genome sequencing (Illumina) revealed blaNDM-5 and aac(6')-Ia, InCX3 plasmid, and the fluoroquinolone resistance-associated gyrAS83Y mutation. Phylogenetic analysis placed the isolate (IOB-SWH-01) within a cluster of recently sequenced S. Typhi strains from India belonging to the H58 haplotype.
To date, NDM-producing S. Typhi has been reported only once, from Pakistan. This is the first documented case in India. The presence of blaNDM-5 in S. Typhi poses a serious clinical and public health threat, given its multidrug-resistant nature and potential for interspecies transmission. Continued genomic surveillance is crucial to monitor its spread and guide treatment strategies.
肠杆菌科细菌对碳青霉烯类抗生素的耐药性日益引起公共卫生关注，主要由碳青霉烯酶如OXA - 48、VIM、NDM和IMP驱动。其中，新德里金属β - 内酰胺酶（NDM）已在包括伤寒沙门氏菌在内的各种肠杆菌科细菌中广泛传播，不过相关报道仍然罕见。
我们报告一名来自班加罗尔的11岁男孩，有10天的高热、寒战、抽搐和咳嗽病史。实验室检查显示C反应蛋白升高、全血细胞计数正常以及小细胞低色素性贫血。呼吸道病原体检测发现人鼻病毒/肠道病毒。血培养生长出非乳糖发酵革兰氏阴性杆菌，通过Vitek ID/AST鉴定为沙门氏菌属。该分离株对氨苄西林、环丙沙星、头孢曲松、四环素和美罗培南耐药，但对阿奇霉素、氯霉素和复方新诺明敏感。血清分型确认血清型为伤寒沙门氏菌。全基因组测序（Illumina）显示blaNDM - 5和aac(6') - Ia、InCX3质粒以及氟喹诺酮耐药相关的gyrAS83Y突变。系统发育分析将该分离株（IOB - SWH - 01）置于来自印度的属于H58单倍型的近期测序的伤寒沙门氏菌菌株簇中。
迄今为止，产NDM的伤寒沙门氏菌仅在巴基斯坦有过一次报道。这是印度首例有记录的病例。鉴于其多重耐药性质和种间传播潜力，伤寒沙门氏菌中blaNDM - 5的存在构成了严重的临床和公共卫生威胁。持续的基因组监测对于监测其传播和指导治疗策略至关重要。
