Laboratorio de Microbiología, Departamento de Ciencias Médicas y de la Vida, Centro Universitario de la Ciénega, Universidad de Guadalajara, Jalisco, Mexico.
Laboratorio de Alimentos, Departamento de Ciencias Médicas y de la Vida, Centro Universitario de la Ciénega, Universidad de Guadalajara, Jalisco, Mexico.
J Microbiol Immunol Infect. 2021 Dec;54(6):1038-1047. doi: 10.1016/j.jmii.2020.07.002. Epub 2020 Jul 10.
BACKGROUND/PURPOSE (S): Nosocomial pathogens can develop biofilms on hospital surfaces and medical devices; however, few studies have focused on the evaluation of mono-and dual-species biofilms developed by nosocomial pathogens under different growth conditions.
This study investigated biofilm development by nosocomial pathogens (Acinetobacter baumannii, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa) on biomaterials in different culture media and their components of the extracellular matrix biofilm.
The mono-species biofilms showed cell densities from 7.50 to 9.27 Log CFU/cm on natural rubber latex type I (NLTI) and from 7.58 to 8.79 Log CFU/cm on stainless steel (SS). Dual-species biofilms consisted of S. aureus + P. aeruginosa (7.87-8.27 Log CFU/cm in TSBP and TSBME onto SS; p < 0.05), E. coli + P. aeruginosa (8.32-8.86 Log CFU/cm in TSBME onto SS and TSBP onto NLTI; p < 0.05), and S. aureus + E. coli (7.82 Log CFU/cm in TSBME onto SS; p < 0.05). Furthermore, biofilm detachment after proteinase K treatment was 5.54-32.81% compared to 7.95-24.15% after DNase I treatment in the mono-dual species biofilm matrix. Epifluorescence microscopy and scanning electron microscopy (SEM) enabled visualizing the bacteria and extracellular polymeric substances of biofilms on SS and NLTI.
Nosocomial pathogens can develop biofilms on biomaterials. Mono-species biofilms of Gram-negative bacteria showed lower densities than dual-species biofilms in TSBME and TSBP. Additionally, dual-species biofilms showed a higher concentration of proteins and eDNA in the extracellular matrix.
背景/目的（S）：医院病原体可以在医院表面和医疗设备上形成生物膜；然而，很少有研究关注医院病原体在不同生长条件下形成的单种和两种生物膜的评估。
本研究调查了医院病原体（鲍曼不动杆菌、金黄色葡萄球菌、大肠杆菌和铜绿假单胞菌）在不同培养基和细胞外基质生物膜成分中的生物材料上形成的生物膜。
单种生物膜在天然橡胶乳胶 I 型（NLTI）上的细胞密度为 7.50 至 9.27 Log CFU/cm，在不锈钢（SS）上的细胞密度为 7.58 至 8.79 Log CFU/cm。双种生物膜由金黄色葡萄球菌+铜绿假单胞菌（在 SS 上的 TSBP 和 TSBME 中为 7.87-8.27 Log CFU/cm；p<0.05）、大肠杆菌+铜绿假单胞菌（在 SS 和 TSBP 上的 TSBME 中为 8.32-8.86 Log CFU/cm；p<0.05）和金黄色葡萄球菌+大肠杆菌（在 SS 上的 TSBME 中为 7.82 Log CFU/cm；p<0.05）组成。此外，与 DNase I 处理相比，蛋白酶 K 处理后，单-双种生物膜基质的生物膜脱落率为 5.54-32.81%。荧光显微镜和扫描电子显微镜（SEM）能够在 SS 和 NLTI 上观察到生物膜中的细菌和细胞外多聚物。
医院病原体可以在生物材料上形成生物膜。在 TSBME 和 TSBP 中，革兰氏阴性菌的单种生物膜密度低于双种生物膜。此外，双种生物膜的细胞外基质中含有更高浓度的蛋白质和 eDNA。
