Detection of Salmonella Typhi and blaCTX-M genes in drinking water, wastewater, and environmental biofilms in Sindh Province, Pakistan.

IF 3.4 2区医学 Q1 PARASITOLOGY

PLoS Neglected Tropical Diseases Pub Date : 2025-04-22 eCollection Date: 2025-04-01 DOI:10.1371/journal.pntd.0012963

Ayesha Tajammul, Scott Benson, Jamil Ahmed, James VanDerslice, Windy D Tanner

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引用次数: 0

Abstract

Typhoid fever poses a significant public health risk, particularly in low- and middle-income countries where access to clean water and improved sanitation may be limited. In Pakistan, this risk is especially serious given the emergence of an extensively drug-resistant (XDR) Salmonella Typhi strain, a strain attributed to S. Typhi acquisition of the blaCTX-M-15 gene. The now-dominant XDR S. Typhi strain, non-XDR S. Typhi, and blaCTX-M genes are readily disseminated via drinking water and wastewater in Pakistan and may also be present in biofilm associated with these environmental sources. This study investigates the presence of S. Typhi and blaCTX-M genes within these environmental compartments. Drinking water (n=35) or wastewater samples (n=35) and samples of their associated biofilms were collected in Karachi and Hyderabad, Pakistan. Samples were tested by PCR for S. Typhi and blaCTX-M group 1 genes as a proxy for blaCTX-M-15. Heterotrophic plate counts (HPC) were conducted to assess microbial load. S. Typhi was detected by PCR in one bulk wastewater sample and one drinking water biofilm. BlaCTX-M group 1 genes were detected in all sample types and were detected more frequently in bulk wastewater (n=13/35) than in drinking water (n=2/35) and more frequently overall in biofilm samples (n=22/70) versus bulk water (n=15/70). Detection of blaCTX-M in biofilm was not significantly associated with detection in the associated bulk water sample. This study marks the first detection of S. Typhi in drinking water biofilm and the first report of blaCTX-M genes in environmental biofilm in Pakistan. Environmental biofilm, particularly in drinking water systems, may serve as reservoirs for human exposure to S. Typhi and drug resistance genes. This study underscores the importance of expanding surveillance strategies to include biofilm sampling, providing valuable insights into pathogen dissemination in water systems, and informing targeted public health interventions to prevent waterborne diseases.

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巴基斯坦信德省饮用水、废水和环境生物膜中伤寒沙门氏菌和blaCTX-M基因的检测

伤寒造成重大的公共卫生风险，特别是在获得清洁水和改善卫生设施的机会可能有限的低收入和中等收入国家。在巴基斯坦，考虑到广泛耐药（XDR）伤寒沙门氏菌菌株的出现，这种风险尤其严重，这种菌株归因于伤寒沙门氏菌获得blaCTX-M-15基因。目前占主导地位的XDR伤寒沙门氏菌菌株、非XDR伤寒沙门氏菌和blaCTX-M基因很容易通过巴基斯坦的饮用水和废水传播，也可能存在于与这些环境来源相关的生物膜中。本研究调查了伤寒沙门氏菌和blaCTX-M基因在这些环境区室中的存在。在巴基斯坦卡拉奇和海得拉巴收集了饮用水（n=35）或废水样本（n=35）及其相关生物膜样本。采用PCR检测伤寒沙门氏菌和blaCTX-M 1组基因，作为blaCTX-M-15的代理基因。采用异养平板计数（HPC）评估微生物负荷。用PCR方法对1份污水样品和1份饮用水生物膜进行了伤寒沙门氏菌检测。BlaCTX-M组1基因在所有样品类型中均检测到，在散装废水（n=13/35）中检测频率高于饮用水（n=2/35），在生物膜样品（n=22/70）中检测频率高于散装水（n=15/70）。生物膜中blaCTX-M的检测与相关大水样中的检测无显著相关。本研究是巴基斯坦首次在饮用水生物膜中检测到伤寒沙门氏菌，也首次报道了在环境生物膜中检测到blaCTX-M基因。环境生物膜，特别是在饮用水系统中，可能成为人类接触伤寒沙门氏菌和耐药基因的水库。这项研究强调了扩大监测战略的重要性，包括生物膜取样，为水系统中的病原体传播提供有价值的见解，并为有针对性的公共卫生干预提供信息，以预防水传播疾病。

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来源期刊

PLoS Neglected Tropical Diseases PARASITOLOGY-TROPICAL MEDICINE

自引率

10.50%

发文量

723

期刊介绍： PLOS Neglected Tropical Diseases publishes research devoted to the pathology, epidemiology, prevention, treatment and control of the neglected tropical diseases (NTDs), as well as relevant public policy. The NTDs are defined as a group of poverty-promoting chronic infectious diseases, which primarily occur in rural areas and poor urban areas of low-income and middle-income countries. Their impact on child health and development, pregnancy, and worker productivity, as well as their stigmatizing features limit economic stability. All aspects of these diseases are considered, including: Pathogenesis Clinical features Pharmacology and treatment Diagnosis Epidemiology Vector biology Vaccinology and prevention Demographic, ecological and social determinants Public health and policy aspects (including cost-effectiveness analyses).