Immunotoxicity of β-Diketone Antibiotic Mixtures to Zebrafish (Danio rerio) by Transcriptome Analysis

Abstract

Fluoroquinolones and tetracyclines are known as β-diketone antibiotics (DKAs) because of bearing a diketone group in their molecular structure. DKAs are the most widely used antibiotics to prevent generation of disease in humans and animals and to suppress bacterial growth in aquaculture. In recent years, overuse of DKAs has caused serious environmental risk due to their pseudo-persistence in the environment, even though their half-lives are not long. So far, no reports were concerned with the joint immunotoxicity of DKAs. Herein, we reported on the immunotoxicity of DKAs on zebrafish after a 3-month DKAs exposure using transcriptomic techniques. According to transcriptome sequencing, 10 differentially expressed genes were screened out among the genes related to KEGG pathways with high enrichment. The identified 7 genes showed to be consistent between RNA-seq and qRT-PCR. Due to DKAs exposure, the content or activity for a series of immune-related biomarkers (Complement 3, lysozyme, IgM and AKP) showed the inconsistent changing trends as compared with the control group. Histopathological observations showed that the number of goblet cells increased sharply, the columnar epithelial cells swelled, the nucleus became slender in intestinal villi, and numerous brown metachromatic granules occurred in spleens of DKAs-exposed groups. Overall, both detection of biomarkers and histopathological observation corroborated that chronic DKAs exposure could result in abnormal expression of immune genes and enzymes, and variable levels of damage to immune-related organs. These complex effects of DKAs may lead to zebrafish dysfunction and occurrence of diseases related to the immune system.

Screening and functional identification of lncRNAs under β-diketone antibiotic exposure to zebrafish ( Danio rerio ) using high-throughput sequencing

“…To date, little information is available for the above-mentioned lncRNAs and therefore the results of this study can enrich the functional database of lncR-NAs. Based on previous immune toxicity research on DKAs by our group (Li et al, 2016a), the transcriptional changes demonstrated for plk3 and syt10 in this study appear to be associated with immune functions and are regulated by the above 3 lncRNAs. The histopathological observations further support our understanding of DKA response to immune toxicity mechanisms.…”

“…Zebrafish in control (0 mg/L) and treatment (6.25 and 12.5 mg/L) groups were randomly selected after DKA exposure at 90 dpf and rinsed with phosphorous buffer solution. The anatomy of the whole fish and total RNA extraction were characterized as detailed in our previous report (Li et al, 2016a). After the quantity and purity of total RNA were determined, the rRNA was removed using a epicentre Ribo-Zero TM kit (Illumina Company, Madison, WI, USA) to recover and purify the remainder of the rRNA depleted RNA (polyA+ and polyA−).…”

“…After the library passed quality control inspection, we used an Illumina Hiseq 2000/2500 to sequence, and sequencing read length was double-ended to be 2 × 125 bp (PE125). The sequencing, evaluation and analysis of library quality were conducted on the basis of our previous report (Li et al, 2016a).…”

A global analysis on the systemic effects of antibiotics in cultured fish and their potential human health risk: a review

“…2014; Li et al . 2016) and excessive dietary dose (Toften & Jobling 1996). In these studies, treated fish had delayed and premature hatching (Zhang et al .…”

Regulatory mechanisms of miR-96 and miR-184 abnormal expressions on otic vesicle development of zebrafish following exposure to β-diketone antibiotics

“…In real-world environments, residual components of antibiotics are very complex and may contribute to joint (i.e., interactive) toxicological effects (Ding et al, 2013;Melvin et al, 2014). Our previous research examined the effects of three representative FQs (enrofloxacin, ofloxacin and ciprofloxacin) and three TCs (chlortetracycline, oxytetracycline and doxycycline) on joint toxicity to various tissues and organs including the immune, reproductive and nervous systems in zebrafish (Danio rerio) (Li et al, 2016a). Some FQ family members, such as ciprofloxacin (Etminan et al, 2017;Samarei et al, 2014), are reported to cause ototoxic effects, while some TC family members, such as doxycycline (Chotmongkol et al, 2012) and minocycline (Corbacella et al, 2004) function to restore hearing loss.…”