摘要
      塑料被认为是细菌的载体，因为它们是生物膜的基质。在这项研究中，我们评估了附着在海洋塑料上的生物膜中粪便和海洋细菌以及抗生素抗性基因（ARGs）的丰度。在地中海西北部受人类粪便污染影响的沿海地区收集了漂浮塑料和沉积物中的塑料。使用培养和/或分子方法来量化粪便指标（大肠杆菌、肠球菌和crAssphage），并通过qPCR检测ARGs-sulI、tetW和blaTEM以及16S rRNA。假单胞菌和弧菌物种以及异养海洋细菌也通过基于培养的方法进行了分析。结果表明，塑料颗粒被细菌生物膜覆盖，主要由包括弧菌在内的海洋细菌组成。一些漂浮塑料的活大肠杆菌和肠球菌浓度较低（分别占塑料的42%和67%）。考虑到塑料的中位面积，我们平均每件物品检测到68 cfu的大肠杆菌，而与100毫升周围的水相比，单个塑料物品检测到的大肠杆菌浓度更高。使用qPCR，我们量化了包括无活性和死亡微生物在内的粪便指标的较高值，检测到高达2.6×102 gc mm−2。在67–88%的漂浮塑料和29–57%的沉积物塑料中检测到ARGs，浓度高达6.7×102 gc mm−2。此外，与周围的水相比，在生物膜中观察到这些基因的富集。这些结果表明，漂浮塑料可以作为附着和运输粪便微生物的管道。相比之下，在海底沉积物的塑料中检测到粪便指标含量较低。因此，尽管浓度较低，但在海洋塑料中发现了粪便细菌和潜在病原体，这进一步表明塑料是病原体和ARGs的宿主。
Abstract
Plastics have been proposed as vectors of bacteria as they act as a substrate for biofilms. In this study, we evaluated the abundance of faecal and marine bacteria and antibiotic resistance genes (ARGs) from biofilms adhered to marine plastics. Floating plastics and plastics from sediments were collected in coastal areas impacted by human faecal pollution in the northwestern Mediterranean Sea. Culture and/or molecular methods were used to quantify faecal indicators (E. coli, Enterococci and crAssphage), and the ARGs sulI, tetW and blaTEM and the 16S rRNA were detected by qPCR assays. Pseudomonas and Vibrio species and heterotrophic marine bacteria were also analysed via culture-based methods. Results showed that, plastic particles covered by bacterial biofilms, primarily consisted of marine bacteria including Vibrio spp. Some floating plastics had a low concentration of viable E. coli and Enterococci (42% and 67% of the plastics respectively). Considering the median area of the plastics, we detected an average of 68 cfu E. coli per item, while a higher concentration of E. coli was detected on individual plastic items, when compared with 100 ml of the surrounding water. Using qPCR, we quantified higher values of faecal indicators which included inactive and dead microorganisms, detecting up to 2.6 × 102 gc mm−2. The ARGs were detected in 67–88% of the floating plastics and in 29–57% of the sediment plastics with a concentration of up to 6.7 × 102 gc mm−2. Furthermore, enrichment of these genes was observed in biofilms compared with the surrounding water. These results show that floating plastics act as a conduit for both the attachment and transport of faecal microorganisms. In contrast, low presence of faecal indicators was detected in plastic from seafloor sediments. Therefore, although in low concentrations, faecal bacteria, and potential pathogens, were identified in marine plastics, further suggesting plastics act as a reservoir of pathogens and ARGs.

https://www.sciencedirect.com/science/article/pii/S0269749122021984