Choi Y K, Goyal S M, Joo H S
Department of Clinical and Population Sciences, University of Minnesota, St. Paul 55108, USA.
Arch Virol. 2002 Jun;147(6):1209-20. doi: 10.1007/s00705-002-0788-4.
Serologic and virologic prevalence of infection with different swine influenza virus (SIV) subtypes was investigated using swine sera, nasal swabs and lung samples that had been submitted for a diagnosis to the Minnesota Veterinary Diagnostic Laboratory. A total of 111,418 pig sera were tested for SIV antibody between 1998 and 2000, and 25,348 sera (22.8%) were found to be positive by the hemagglutination inhibition (HI) test. Of the positive samples, 16,807 (66.7%) and 8,541 (33.7%) had antibody to H1 and H3 subtypes, respectively. Between January 1998 and May of 2001, a total of 3,561 nasal swabs or lung samples were examined for the presence of SIV, and SIV was isolated from 1,124 samples (31.7%). Of these isolates, 869 (77.3%) and 255 (22.7%) were subtyped as H1 and H3, respectively, by the HI method. For further characterization, 120 SIV isolates each from 1998 to 2001 were randomly selected from a culture collection and their hemagglutinin (HA) and neuraminidase genes examined by reverse transcription-PCR and sequencing. Of the 480 isolates, 322 (67.1%), 22 (4.6%) and 129 (26.9%) were subtyped as H1N1, H1N2 and H3N2, respectively. The remaining 7 samples (1.5%) were found to contain both H1N1 and H3N2 viruses. The SIV H1N2 subtype was isolated from 1, 8, and 13 samples in 1999, 2000, and 2001, respectively. The 22 H1N2 isolates originated from 9 different states of the United States. Genetic screening of the HA genes of 12 selected H1N2 isolates showed that 8 of them had a close phylogenetic relationship with the Indiana isolate of H1N2 (A/Swine/Indiana/9K035/99), while 4 isolates were closely related to classical SIV H1N1.
利用提交至明尼苏达兽医诊断实验室用于诊断的猪血清、鼻拭子和肺样本，对不同猪流感病毒（SIV）亚型感染的血清学和病毒学流行情况进行了调查。1998年至2000年期间，共对111418份猪血清进行了SIV抗体检测，通过血凝抑制（HI）试验发现25348份血清（22.8%）呈阳性。在阳性样本中，分别有16807份（66.7%）和8541份（33.7%）具有针对H1和H3亚型的抗体。1998年1月至2001年5月期间，共对3561份鼻拭子或肺样本进行了SIV检测，从1124份样本（31.7%）中分离出了SIV。在这些分离株中，通过HI方法分别将869份（77.3%）和255份（22.7%）鉴定为H1和H3亚型。为了进一步进行特征分析，从培养物保藏中随机选取了1998年至2001年期间的120份SIV分离株，并通过逆转录 - PCR和测序对其血凝素（HA）和神经氨酸酶基因进行了检测。在480份分离株中，分别有322份（67.1%）、22份（4.6%）和129份（26.9%）被鉴定为H1N1、H1N2和H3N2亚型。其余7份样本（1.5%）被发现同时含有H1N1和H3N2病毒。分别在1999年、2000年和2001年从1份、8份和13份样本中分离出了SIV H1N2亚型。这22份H1N2分离株来自美国9个不同的州。对12份选定的H1N2分离株的HA基因进行的基因筛查表明，其中8份与H1N2的印第安纳分离株（A/Swine/Indiana/9K035/99）具有密切的系统发育关系，而4份分离株与经典SIV H1N1密切相关。
