Domen Andrea, Porter Jenna, Johnson Jared, Molyneux James, McIntyre Lorraine, Kovacevic Jovana, Waite-Cusic Joy
Food Innovation Center, Oregon State University, Portland, Oregon, USA.
Department of Food Science and Technology, Oregon State University, Corvallis, Oregon, USA.
Appl Environ Microbiol. 2025 Jan 31;91(1):e0128124. doi: 10.1128/aem.01281-24. Epub 2024 Nov 21.
Increased tolerance to cadmium in has been suggested to contribute to their persistence in natural and food production environments. This study investigated the phenotypic cadmium response of strains with efflux pump (variants 1-4) and related strains with . Growth of variant strains ( = 5) in 0 µM-120 µM cadmium salts (CdCl, CdSO) in Mueller-Hinton broth (MHB) was evaluated. Additionally, 88 . strains from dairy processing facilities were exposed to 43.8 µM CdCl in MHB, and their lag phase duration (LPD) was measured. Strains with through showed similar growth trends in the presence of cadmium, while the variant (Scott A) had the highest CdCl minimum inhibitory concentration (175 µM). Growth varied between the two salts, with CdSO significantly increasing LPD ( < 0.05) compared to CdCl. In 43.8 µM CdCl, strains displayed LPDs ranging from 0.99 ± 0.14 h to 6.44 ± 0.08 h, with no clear genomic differences explaining this variability. Strains without did not grow at 43.8 µM CdCl but exhibited low tolerance (10.9 µM CdCl), potentially due to non-specific soft metal ATPases (626 aa; 737 aa) and soft metal resistance proteins encoded by genes (289 aa; 291 aa; 303 aa) within their chromosomes. These findings enhance our understanding of cadmium tolerance and underscore the need for further research to explore the genetic and physiological factors underlying these trends.
Mobile genetic elements in contribute to its survival in natural and food processing environments. This study focused on how different genetic variants of the efflux pump gene and group of closely related strains respond to cadmium exposure. When exposed to two cadmium salts, cadmium chloride and cadmium sulfate, we observed varying growth patterns, with a significantly longer lag phase in cadmium sulfate compared to cadmium chloride. Strains with to had similar growth trends, whereas a strain with the variant had the highest minimum inhibitory concentration value. Among 88 strains from dairy processing facilities, significant phenotypic differences were observed despite core genome similarities, indicating other underlying genetic and physiological factors contribute to cadmium tolerance. Since cadmium tolerance studies in are limited, with rare phenotypic comparisons between closely related strains, our study makes an important observation and contribution to understanding of tolerance to cadmium by providing phenotypic comparisons between numerous strains within the same clonal group (<16 single nucleotide polymorphisms).
有人认为，[具体微生物名称]对镉的耐受性增强有助于其在自然环境和食品生产环境中持续存在。本研究调查了具有外排泵[泵基因名称]（变体1 - 4）的[具体微生物名称]菌株以及与之相关的具有[相关基因名称]的菌株对镉的表型反应。评估了[具体微生物名称]变体菌株（n = 5）在穆勒 - 欣顿肉汤（MHB）中0 μM - 120 μM镉盐（CdCl₂、CdSO₄）中的生长情况。此外，将来自乳制品加工设施的88株[具体微生物名称]菌株暴露于MHB中的43.8 μM CdCl₂，并测量其延迟期持续时间（LPD）。具有[泵基因名称]变体1至4的菌株在镉存在下表现出相似的生长趋势，而[泵基因名称]变体（Scott A）的CdCl₂最低抑菌浓度最高（175 μM）。两种盐之间的生长情况有所不同，与CdCl₂相比，CdSO₄显著增加了LPD（P < 0.05）。在43.8 μM CdCl₂中，[具体微生物名称]菌株的LPD范围为0.99 ± 0.14小时至6.44 ± 0.08小时，没有明显的基因组差异可以解释这种变异性。没有[泵基因名称]的菌株在43.8 μM CdCl₂中不生长，但表现出低耐受性（10.9 μM CdCl₂），这可能是由于其染色体中的非特异性软金属ATP酶（626个氨基酸；737个氨基酸）以及由[相关基因名称]基因编码的软金属抗性蛋白（289个氨基酸；291个氨基酸；303个氨基酸）。这些发现增进了我们对[具体微生物名称]镉耐受性的理解，并强调需要进一步研究以探索这些趋势背后的遗传和生理因素。
[具体微生物名称]中的移动遗传元件有助于其在自然和食品加工环境中生存。本研究聚焦于外排泵基因[泵基因名称]的不同遗传变体以及一组密切相关的[具体微生物名称]菌株如何应对镉暴露。当暴露于两种镉盐，即氯化镉和硫酸镉时，我们观察到不同的生长模式，与氯化镉相比，硫酸镉中的延迟期明显更长。具有[泵基因名称]变体1至4的菌株具有相似的生长趋势，而具有[泵基因名称]变体的菌株具有最高的最低抑菌浓度值。在来自乳制品加工设施的88株菌株中，尽管核心基因组相似，但仍观察到显著的表型差异，这表明其他潜在的遗传和生理因素有助于镉耐受性。由于对[具体微生物名称]镉耐受性的研究有限，且密切相关菌株之间的表型比较很少，我们的研究通过提供同一克隆组内众多菌株（<16个单核苷酸多态性）之间的表型比较，对理解[具体微生物名称]对镉的耐受性做出了重要观察和贡献。
