In order to investigate enterobacteria presence involved in the secondary infections in Porcine Reproductive and Respiratory Syndrome (PRRS) pigs with different viral co-infections, we identified enterobacteria for guiding clinical treatment. Twenty-one diseased pigs were diagnosed with the PRRS virus (PRRSV) and other 7 virus primers by PCR/RT-PCR in the lung and spleen samples. Enterobacteria were isolated using MacConkey agar from 5 visceral samples of PRRS pigs, and identified by 16S rDNA sequencing. PRRSV was positive in 100% of the lung samples and 81.0% of the spleen samples. Seven diseased pigs were diagnosed with only PRRSV infection (33.3%), 7 pigs with PRRSV and 1 or 2 other viruses (33.3%) and 7 pigs with PRRSV and more than 2 types of other viruses (33.3%). PRRSV was more inclined to co-infect pigs with porcine group A rotavirus (PARV) with the co-infection rate of 52.4% (11/21). Approximately 13 types of bacteria were successfully isolated from lung, spleen, liver, kidney and lymph node samples of different PRRS pigs. Enterobacteria were isolated in 100% of lung, liver and lymph samples from pigs infected with PRRSV alone. However, the isolation rates were significantly decreased in the more than 3 viruses co-infection group. Escherichia coli was the most prevalent bacterium, followed by Morganella, Proteus, Shigella, Salmonella, Klebsiella and Aeromonas. Most of the isolated enterobacteria were opportunistic pathogens. Therefore, timely combination with antimicrobial agents is necessary for effective treatment of PRRS-infected pigs.

为了调查与不同病毒共感染的猪繁殖与呼吸综合征（PRRS）猪的继发感染有关的肠杆菌的存在，我们确定了肠杆菌可以指导临床治疗。通过PCR / RT-PCR在肺和脾脏样本中诊断出21只患病猪带有PRRS病毒（PRRSV）和其他7种病毒引物。使用MacConkey琼脂从5头PRRS猪的内脏样本中分离出肠杆菌，并通过16S rDNA测序进行鉴定。PRRSV在100％的肺部样本和81.0％的脾脏样本中呈阳性。七只患病猪被诊断出仅感染PRRSV（33.3％），七只猪患有PRRSV和一种或两种其他病毒（33.3％），七只猪患有PRRSV和两种以上其他病毒（33.3％）。PRRSV更倾向于与猪A型轮状病毒（PARV）共同感染猪，共同感染率为52.4％（11/21）。从不同PRRS猪的肺，脾，肝，肾和淋巴结样本中成功分离出大约13种细菌。从仅感染PRRSV的猪的100％肺，肝和淋巴样本中分离出肠杆菌。但是，在3种以上的病毒共感染组中，分离率显着降低。大肠杆菌是最普遍的细菌，随后摩根，变形杆菌属，志贺氏菌，沙门氏菌属，克雷伯氏菌和嗜。大多数分离的肠细菌是机会病原体。因此，及时与抗菌药物联合使用对于有效治疗PRRS感染的猪是必要的。