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Journal of Virology, March 2007, p. 2999-3004, Vol. 81, No. 6
0022-538X/07/$08.00+0 doi:10.1128/JVI.02090-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.
Phylogenetic Analysis of Feline Immunodeficiency Virus in Feral and Companion Domestic Cats of New Zealand
Jessica J. Hayward,1
John Taylor,2 and
Allen G. Rodrigo1*
Bioinformatics Institute, Allan Wilson Centre for Molecular Ecology and Evolution,1
School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland Mail Centre, Auckland 1142, New Zealand2
Received 25 September 2006/
Accepted 18 December 2006

ABSTRACT
Nested PCR was used to amplify envelope V3-V6 gene fragments
of feline immunodeficiency virus (FIV) from New Zealand cats.
Phylogenetic analyses established that subtypes A and C predominate
among New Zealand cats, with clear evidence of intersubtype
recombination. In addition, 17 sequences were identified that
were distinct from all known FIV clades, and we tentatively
suggest these belong to a novel subtype.

TEXT
Feline immunodeficiency virus (FIV) is a lentivirus that infects
the domestic cat (
Felis catus), causing progressive immunodeficiency
analogous to AIDS in humans (
21). Five distinct FIV subtypes
have been identified, based on sequence diversity within the
V3 to V5 region of the envelope gene (
13,
20,
29). A recent
study identified a distinct group of FIV isolates from Texas
that possibly represent a new subtype (
32). In addition, intersubtype
recombination has been detected in natural populations (
1,
4,
23).
The only previously published study on FIV in New Zealand cats examined the infection status of 250 domestic cats of different sex, age, breed, and health condition (30). In the present study, New Zealand cats were sampled from April 2003 to January 2006. Lymph nodes were dissected from 334 New Zealand feral cats and 28 New Zealand stray cats obtained from seven locations throughout both the North and South Islands of New Zealand. Feral cats are defined as unowned cats that inhabit rural areas, including wooded countryside and parkland, whereas stray cats inhabit urban areas. Blood samples from 48 FIV-symptomatic domestic New Zealand cats were also obtained from a local veterinary diagnostic facility, and a further 29 seropositive New Zealand domestic cat blood samples were sourced from veterinarians. Genomic DNA was extracted from lymph nodes by using QIAamp DNA Minikit (QIAGEN) and from blood samples by using QIAamp DNA blood minikit (QIAGEN).
Nested PCR was used to amplify 858 bp of the FIV envelope gene within the V3 to V6 region. Briefly, a 25-µl reaction containing 0.4 µM concentrations of each primer, 0.2 mM concentrations of each deoxynucleoside triphosphate, and 0.625 U of Platinum Taq DNA polymerase was used. In the first round, 2 µl of genomic DNA was added. In the second round, 1 µl from the first round tube was added. The reactions were run on a Biometra T1 thermal cycler. The first-round primers, VE1R and VE1S, amplified a 1,230-bp fragment containing the annealing sites for the second-round primers, VE2R and VE2S (17). Thermal cycling parameters used were as follows: 3 min at 94°C, followed by 5 cycles of 1 min at 94°C, 1 min at 57°C, and 2 min at 72°C, followed in turn by 31 cycles of 15 s at 94°C, 45 s at 57°C, and 1 min at 72°C, followed finally by extension for 2 min at 72°C. PCR products were visualized by electrophoresis on a 1.6% agarose gel at 100 V.
Direct sequencing of PCR products was performed by using a BigDye terminator version 3.1 ready reaction cycle sequencing kit and an Applied Biosystems genetic analyzer AB13730. Sequences were edited in Sequencher v4.1 (Genecodes Corp.). A multiple alignment was constructed by using CLUSTALX v1.81 (11, 12). In Se-Al v2.0a11 Carbon (A. Rambaut, University of Oxford) a 33-bp ambiguously aligned region of V5 was deleted to exclude it from subsequent analyses. The best model of evolution for our data was determined by using Modeltest v3.7 (22). This model, TVM+I+G, allowing for variable rates across sites and a proportion of invariant sites, was used to construct a neighbor-joining (NJ) tree (27) with PAUP* v4.0b10 (31). A nonparametric bootstrap (6) with 1,000 replicates was conducted.
Novel sequences from New Zealand cats were submitted to GenBank (accession numbers EF153955 to EF154083).
FIV subtypes A and C predominate within infected New Zealand cats (Fig. 1). The principal subtype is C, comprising 48% (±4.4%) of all sequences (Table 1) . Although there is some clustering of sequences from the same location, such as that seen from Great Barrier Island in subtype A, there is no obvious geographical pattern to the subtypes found throughout NZ. Australia, the country closest to New Zealand, has only subtypes A and, more rarely, B (14). Thus, the high prevalence of FIV-C in New Zealand cats was unexpected. FIV subtype A sequences from three infected Australian cats were included in Fig. 1 to determine whether Australia is a potential country of origin of New Zealand FIV-A. These Australian sequences group within the New Zealand subtype A clade, as did reference FIV-A sequences from other countries; thus, there is no firm evidence that Australia is the origin of New Zealand FIV-A.
A group of 17 New Zealand sequences, 11 of which are from feral
cats from one location, did not group with any known subtype
on the phylogenetic tree. Fifteen sequences from this group
are very closely related (91.0% similarity), suggesting their
recent spread in New Zealand cats. All 17 sequences were analyzed
by using a recombination identification program (RIP) (
28;
http://hivweb.lanl.gov/RIP/RIPsubmit.html)
to test for recombination. None of these sequences showed any
significant similarity to any previously described subtype (Fig.
2a), nor did they appear to be recombinants of known subtypes.
Two lymph node samples, one that yielded FIV sequence of subtype
C and another of the "unknown" subtype, were amplified and sequenced
independently at the School of Veterinary Science, University
of Queensland, in a blind, independent check for contamination.
These sequences were almost identical (99%) to those we obtained,
thus confirming the novelty of the "unknown" group. We note
that the suggested requirements for designating a new human
immunodeficiency virus subtype requires three genome sequences
from epidemiologically independent infected individuals (
24).
While FIV subtype designation has been based on V3-V5
env sequence
(
29), we are currently sequencing the
pol and
gag genes to provide
further sequence data to validate the "unknown" group as a novel
NZ-specific subtype.
Eleven other sequences that did not group with any subtype were
tested for recombination by using RIP (Fig.
2b and c). A Kishino-Hasegawa
(KH) test (
9,
10,
15) implemented in PAUP* was used to further
investigate recombination. Thirteen reference sequences were
used in each KH test: five subtype A sequences, five subtype
C sequences, and one sequence of each subtype B, D, and E. The
results from this test (Table
2) show that, conservatively,
9 of the 11 samples can be assigned as putative recombinants
of subtypes A and C.
To exclude PCR-mediated recombination as a potential source
for these putative recombinants (
16,
18), we used endpoint dilution
(
25,
26) on representative samples from which recombinants were
detected. Because of limited sample availability, we were only
able to perform these tests on five of the nine putative recombinants
(Table
2). A fivefold serial dilution was used, and the PCR
results were entered into QUALITY (
http://ubik.microbiol.washington.edu/computing/quality/jquality.htm)
to determine the proviral copy number. Samples were then diluted
to an endpoint and amplified to give at least five sequences.
In all cases, the endpoint sequences were at least 98% similar
to the respective consensus sequences and to each other. Consequently,
these recombinants are confirmed as authentic viral sequences,
and there is no evidence of dual infection.
Of the 334 feral cats tested, 72 (21.5% ± 2.25%) were positive for FIV proviral DNA. This is generally higher than other feral cat populations globally (2, 8, 19, 33; however, see also reference 3). The FIV prevalence in feral cats from the five New Zealand locations ranges from 11 to 36%, with no obvious geographic pattern (Fig. 1).
More than two-thirds of the FIV-infected feral cats were male, a statistically significant difference (
2 = 14.16, df = 1, P
0.001), and adult male cats had the highest prevalence of 51% (n = 70). This trend is expected because mature male cats demonstrate higher levels of social aggression, caused by competition over mates and territories (5, 7). Thus, mature male cats tend to have a greater number of biting encounters, the typical mode of transmission of FIV (34).
This study is the first to use phylogenetics to analyze FIV in New Zealand cats. Two subtypes and nine putative A/C recombinant strains are identified in New Zealand cats. A novel clade was detected, possibly representing a New Zealand-specific subtype.

ACKNOWLEDGMENTS
We thank the New Zealand Department of Conservation; the Whangarei
branch of the Society for the Prevention of Cruelty to Animals;
the Lonely Miaow Association, Inc.; the Epsom Central Veterinary
Centre; Gribbles Laboratories; Gribbles-Alpha (formerly Alpha
Scientific, Hamilton); the Blockhouse Bay Veterinary Centre;
Animals! The Vets!; Buller Veterinary Services; and New Zealand
Veterinary Pathology, Palmerston North. We are grateful to Zainab
Issa for initial help with labwork. Sequencing was carried out
at the Allan Wilson Centre sequencing facility, Massey University,
Albany, New Zealand.
This research was funded by a grant from the National Institutes of Health and with support from both the Allan Wilson Centre for Molecular Ecology and Evolution (New Zealand) and the University of Auckland, Auckland, New Zealand.

FOOTNOTES
* Corresponding author. Mailing address: Bioinformatics Institute, University of Auckland, Private Bag 92019, Auckland Mail Centre, Auckland 1142, New Zealand. Phone: (649) 373 7599, x87296. Fax: (649) 367 7136. E-mail:
a.rodrigo{at}auckland.ac.nz.

Published ahead of print on 27 December 2006. 

REFERENCES
1 - Bachmann, M. H., C. Mathiason-Dubard, G. H. Learn, A. G. Rodrigo, D. L. Sodora, P. Mazzetti, E. A. Hoover, and J. I. Mullins. 1997. Genetic diversity of feline immunodeficiency virus: dual infection, recombination, and distinct evolutionary rates among envelope sequence clades. J. Virol. 71:4241-4253.[Abstract]
2 - Baneth, G., P. H. Kazz, D. Steinfeld, and M. Besser. 1999. A seroepidemiological study of feline coronavirus, feline immunodeficiency virus and feline leukemia virus among cats in Israel. Israel J. Vet. Med. 70:55-56.
3 - Bennett, M., C. McCracken, H. Lutz, C. J. Gaskell, R. M. Gaskell, A. Brown, and J. O. Knowles. 1989. Prevalence of antibody to feline immunodeficiency virus in some cat populations. Vet. Rec. 124:397-398.[Medline]
4 - Carpenter, M. A., E. W. Brown, D. W. MacDonald, and S. J. O'Brien. 1998. Phylogeographic patterns of feline immunodeficiency virus genetic diversity in the domestic cat. Virology 251:234-243.[CrossRef][Medline]
5 - Courchamp, F., N. G. Yoccoz, M. Artois, and D. Pontier. 1998. At-risk individuals in feline immunodeficiency virus epidemiology: evidence from a multivariate approach in a natural population of domestic cats (Felis catus). Epidemiol. Infect. 121:227-236.[CrossRef][Medline]
6 - Felsenstein, J. 1985. Confidence limits on phylogenies: an approach using the bootstrap. Evolution 39:783-791.[CrossRef]
7 - Fromont, E., F. Courchamp, M. Artois, and D. Pontier. 1997. Infection strategies of retroviruses and social grouping of domestic cats. Can. J. Zool. 75:1994-2002.
8 - Gibson, K. L., K. Keizer, and C. Golding. 2002. A trap, neuter, and release program for feral cats on Prince Edward Island. Can. Vet. Med. Assoc. 43:695-698.
9 - Goldman, N., J. P. Anderson, and A. G. Rodrigo. 2000. Likelihood-based tests of topologies in phylogenetics. Syst. Biol. 49:652-670.[Abstract/Free Full Text]
10 - Hasegawa, M., and H. Kishino. 1989. Confidence limits on the maximum-likelihood estimate of the hominoid tree from mitochondrial-DNA sequences. Evolution 43:672-677.[CrossRef]
11 - Higgins, D. G., and P. M. Sharp. 1988. CLUSTAL: a package for performing multiple sequence alignment on a microcomputer. Gene 73:237-244.[CrossRef][Medline]
12 - Jeanmougin, F., J. D. Thompson, M. Gouy, D. G. Higgins, and T. J. Gibson. 1998. Multiple sequence alignment with CLUSTAL X. Trends Biochem. Sci. 23:403-405.[CrossRef][Medline]
13 - Kakinuma, S., K. Motokawa, T. Hohdatsu, J. K. Yamamoto, H. Koyama, and H. Hashimoto. 1995. Nucleotide sequence of feline immunodeficiency virus: classification of Japanese isolates into two subtypes which are distinct from non-Japanese subtypes. J. Virol. 69:3639-3646.[Abstract]
14 - Kann, R. K. C., M. T. Kyaw-Tanner, J. M. Seddon, P. R. Lehrbach, R. J. G. Zwijnenberg, and J. Meers. 2006. Molecular subtyping of feline immunodeficiency virus from domestic cats in Australia. Aust. Vet. J. 84:112-116.[Medline]
15 - Kishino, H., and M. Hasegawa. 1989. Evaluation of the maximum-likelihood estimate of the evolutionary tree topologies from DNA sequence data, and the branching order in Hominoidea. J. Mol. Evol. 29:170-179.[CrossRef][Medline]
16 - Meyerhans, A., J. P. Vartanian, and S. Wain-Hobson. 1990. DNA recombination during PCR. Nucleic Acids Res. 18:1687-1691.[Abstract/Free Full Text]
17 - Nishimura, Y., S. Nakamura, N. Goto, T. Hasegawa, H. Pang, Y. Goto, H. Kato, H. Y. Youn, Y. Endo, T. Mizuno, Y. Momoi, K. Ohno, T. Watari, H. Tsujimoto, and A. Hasegawa. 1996. Molecular characterization of feline immunodeficiency virus genome obtained directly from organs of a naturally infected cat with marked neurological symptoms and encephalitis. Arch. Virol. 141:1933-1948.[CrossRef][Medline]
18 - Odelberg, S. J., R. B. Weiss, A. Hata, and R. White. 1995. Template-switching during DNA synthesis by Thermus aquaticus DNA polymerase I. Nucleic Acids Res. 23:2049-2057.[Abstract/Free Full Text]
19 - Ostrowski, S., M. Van Vuuren, D. M. Lenain, and A. Durand. 2003. A serologic survey of wild felids from central west Saudi Arabia. J. Wildl. Dis. 39:696-701.[Abstract]
20 - Pecoraro, M. R., K. Tomonaga, T. Miyazawa, Y. Kawaguchi, S. Sugita, Y. Tohya, C. Kai, M. E. Etcheverrigaray, and T. Mikami. 1996. Genetic diversity of Argentine isolates of feline immunodeficiency virus. J. Genet. Virol. 77:2031-2035.[Abstract/Free Full Text]
21 - Pedersen, N. C., and J. E. Barlough. 1991. Clinical overview of feline immunodeficiency virus. J. Am. Vet. Med. Assoc. 199:1298-1305.[Medline]
22 - Posada, D., and K. A. Crandall. 1998. MODELTEST: testing the model of DNA substitution. Bioinformatics 14:817-818.[Abstract/Free Full Text]
23 - Reggeti, F., and D. Bienzle. 2004. Feline immunodeficiency virus subtypes A, B and C and intersubtype recombinants in Ontario, Canada. J. Gen. Virol. 85:1843-1852.[Abstract/Free Full Text]
24 - Robertson, D. L., J. P. Anderson, J. A. Bradac, J. K. Carr, B. Foley, R. K. Funkhouser, F. Gao, B. H. Hahn, M. L. Kalish, C. Kuiken, G. H. Learn, T. Leitner, F. McCutchan, S. Osmanov, M. Peeters, D. Pieniazek, M. Salminen, P. M. Sharp, S. Wolinsky, and B. Korber. 2000. HIV-1 nomenclature proposal. Science 288:55-57.
25 - Rodrigo, A. G., P. C. Goracke, K. Rowhanain, and J. I. Mullins. 1997. Quantitation of target molecules from polymerase chain reaction-based limiting dilution assays. AIDS Res. Hum. Retrovir. 13:737-742.[Medline]
26 - Rodrigo, A. G., E. W. Hanley, P. C. Goracke, and G. H. Learn. 2001. Sampling and processing HIV molecular sequences: a computational evolutionary biologist's perspective, p. 300. In A. G. Rodrigo and G. H. Learn (ed.), Computational and evolutionary analysis of HIV molecular sequences. Kluwer Academic Publishers, Boston, MA.
27 - Saitou, N., and M. Nei. 1987. The neighbor-joining method: a new method for reconstructing phylogenetic trees. Mol. Biol. Evol. 4:406-425.[Abstract]
28 - Siepel, A. C., A. L. Halpern, C. Macken, and B. T. M. Korber. 1995. A computer program designed to rapidly screen for HIV-1 intersubtype recombinant sequences. AIDS Res. Hum. Retrovir. 11:1413-1416.[Medline]
29 - Sodora, D. L., E. G. Shpaer, B. E. Kitchell, S. W. Dow, E. A. Hoover, and J. I. Mullins. 1994. Identification of three feline immunodeficiency virus (FIV) env gene subtypes and comparison of the FIV and human immunodeficiency virus type 1 evolutionary patterns. J. Virol. 68:2230-2238.[Abstract/Free Full Text]
30 - Swinney, G. R., J. V. Pauli, B. R. Jones, and C. R. Wilks. 1989. Feline t-lymphotropic virus (FTLV) (feline immunodeficiency virus infection) in cats in New Zealand. New Zealand Vet. J. 37:41-43.
31 - Swofford, D. L. 2002. PAUP*. Phylogenetic analysis using parsimony (*and other methods), version. 4. Sinauer Associates, Sunderland, MA.
32 - Weaver, E. A., E. W. Collisson, M. Slater, and G. Zhu. 2004. Phylogenetic analyses of Texas isolates indicate an evolving subtype of the clade B feline immunodeficiency viruses. J. Virol. 78:2158-2163.[Abstract/Free Full Text]
33 - Winkler, I. G., M. Löchelt, and R. L. P. Flower. 1999. Epidemiology of feline foamy virus and feline immunodeficiency virus infections in domestic and feral cats: a seroepidemiological study. J. Clin. Microbiol. 37:2848-2851.[Abstract/Free Full Text]
34 - Yamamoto, J. K., H. Hansen, E. W. Ho, T. Y. Morishita, T. Okuda, T. R. Sawa, R. M. Nakamura, and N. C. Pedersen. 1989. Epidemiologic and clinical aspects of feline immunodeficiency virus infection in cats from the continental United States and Canada and possible mode of transmission. J. Am. Vet. Med. Assoc. 194:213-220.[Medline]
Journal of Virology, March 2007, p. 2999-3004, Vol. 81, No. 6
0022-538X/07/$08.00+0 doi:10.1128/JVI.02090-06
Copyright © 2007, American Society for Microbiology. All Rights Reserved.
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