Pig anelloviruses are highly prevalent in swine herds in France

Abstract

A survey of anelloviruses in swine herds from Britanny, France, is reported. By using PCR targeted to the conserved untranslated region, prevalences of 93 and 73 % were found among 15 herds and 33 animals, respectively. The lung was the organ found to be positive most frequently among the five organs tested from 32 animals. The highest identity levels of our nucleotide sequences were found with pig isolates from Japan and with an isolate from Tupaia belangeri. Interestingly, when aligning all available swine isolates from France and Japan, at least two phylogenetic groups were identified, each one containing clones from France and Japan. Some animals carried clones from both groups, demonstrating intra-individual variability. Despite the putative harmlessness of anelloviruses, the potential inoculum carried by pigs must be further evaluated as a sanitary threat.Anellovirus is a recently created, floating genus of small, non-enveloped viruses that infect a wide range of mammalian species (Biagini et al., 2004). Their genome is composed of circular, negative-sense, single-stranded DNA that carries an untranslated region (UTR) and at least two majors ORFs. The type species, Torque teno virus (TTV), was discovered in a human patient affected by hepatitis of unknown origin (Nishizawa et al., 1997). In a short time, the suspected relationship between TTV and hepatitis, or any other pathology, was rejected after multiple reports of very high viral prevalences in diverse human populations, ranging around 80 % (reviewed by Bendinelli et al., 2001). Moreover, TTV infects not only the liver, but also many other organs, of a single individual without apparent pathology. Between isolates, the virus exhibited high genomic diversity: at the time of writing, human TTV variants are classified into five major phylogenetic groups (Peng et al., 2002). Noticeably, human individuals may carry several distinct genotypes (Ball et al., 1999; Biagini et al., 1999;Jelcic et al., 2004;Kakkola et al., 2004;Verschoor et al., 1999).Other anelloviruses have been partially or fully characterized in several animal species, including domestic animals, such as dogs, cats, pigs, bovines, chickens and ovines, as well as wild animals, such as tupaias (tree shrews) and non-human primates (Cong et al., 2000;Leary et al., 1999;Okamoto et al., 2001bOkamoto et al., , 2002Verschoor et al., 1999). Interestingly, the genome of anelloviruses tends to be smaller when the order of the infected animal is lower, varying from 3?8 kb for human viruses to 2?2 kb for tupaia viruses and reaching 2?9 kb for the only available fulllength viral genome from a pig (Sus domesticus) in Japan (tentatively named TTV-Sd31) . Although less exhaustive than for humans, studies suggest high natural prevalences of anelloviruses in some animals, as well as some intra-and inter-individual genetic variability (Okamoto et al., 2001b;Thom et al., 2003;Verschoor et al., 1999). Recently, viral prevalences ranging between 33 and 100 % have been reported in the sera of pigs from Canada, Chi...

Interstitial nephritis of slaughtered pigs in the State of Mato Grosso, Brazil

“…The high occurrence of TTV infection (20-73%) observed in these pigs agrees with results previously reported (Leary et al 1999, Bigarré et al 2005. Such a high prevalence can be explained by the containment conditions that facilitates transmission (Deng et al 2000, Gerner et al 2000, Martínez-Guinó et al 2009) and the ubiquitous characteristic of TTV.…”

A Novel Porcine Circovirus Distantly Related to Known Circoviruses Is Associated with Porcine Dermatitis and Nephropathy Syndrome and Reproductive Failure

“…Relatively little is known about the clinical significance of TTV infection. TTV is ubiquitous in pigs worldwide (48)(49)(50). While TTV is commonly detected in healthy pigs, several studies have suggested that TTV infection moderates disease severity during coinfections.…”

Infection Dynamics of <i>Torque Teno Sus Virus</i> Types <i>1</i> and <i>2</i> in Serum and Peripheral Blood Mononuclear Cells

“…On the other hand, TTSuV2 was detected in all pSE (100%, 8/8) at 14 days of age but showed a reduced value of 62.5 (5/8) at 30 days of age; however, the virus was detected in all pSE (100%, 8/8) [3][4][5][6][7][8] in more than one sampling times and showed consecutive PCR positivity in at least 2 sampling ages. On the contrary, 62.5% (5 out of 8) of pSE were TTSuV2 PCR positive (No.…”

“…On the contrary, 62.5% (5 out of 8) of pSE were TTSuV2 PCR positive (No. [3][4][5][6]8) at all sampling ages while none of the pSE was TTSuV2 PCR negative throughout the study period. All pSE (100%, 8/8) were TTSuV2 PCR positive in more than one sampling age and showed PCR positive in at least 2 consecutive sampling ages.…”

“…TTSuV1 and TTSuV2 (TTSuVs) have been detected from serum, plasma, semen, faeces, colostrum, nasal secretion and various tissues [5,8,13,26,29,30] exclusively by Polymerase chain reaction (PCR), and different pig rearing countries have reported prevalence rate ranging from 24 to 100% [4,8,[14][15][16][17][24][25][26]. Limited longitudinal studies employing serum [17,26] and cross-sectional studies employing serum and tissues [1,8,9,27] have shown that TTSuV infection increases with age.…”