CA88, a nuclear repetitive DNA sequence identified in Schistosoma mansoni, aids in the genotyping of nine Schistosoma species of medical and veterinary importance

CA88 is the first long nuclear repetitive DNA sequence identified in the blood fluke, Schistosoma mansoni. The assembled S. mansoni sequence, which contains the CA88 repeat, has 8,887 nucleotides and at least three repeat units of approximately 360 bp. In addition, CA88 also possesses an internal CA microsatellite, identified as SmBr18. Both PCR and BLAST analysis have been used to analyse and confirm the CA88 sequence in other S. mansoni sequences in the public database. PCR-acquired nuclear repetitive DNA sequence profiles from nine Schistosoma species were used to classify this organism into four genotypes. Included among the nine species analysed were five sequences of both African and Asian lineages that are known to infect humans. Within these genotypes, three of them refer to recognised species groups. A panel of four microsatellite loci, including SmBr18 and three previously published loci, has been used to characterise the nine Schistosoma species. Each species has been identified and classified based on its CA88 DNA fingerprint profile. Furthermore, microsatellite sequences and intra-specific variation have also been observed within the nine Schistosoma species sequences. Taken together, these results support the use of these markers in studying the population dynamics of Schistosoma isolates from endemic areas and also provide new methods for investigating the relationships between different populations of parasites. In addition, these data also indicate that Schistosoma magrebowiei is not a sister taxon to Schistosoma mattheei, prompting a new designation to a basal clade.

Angiogenesis and experimental hepatic fibrosis

Angiogenesis is a basic change occurring during repair by granulation tissue. This process seems to precede fibrosis formation in most types of chronic liver disease. To examine its presence and significance in different types of hepatic insults, this paper sought to identify the presence, evolution and peculiarities of angiogenesis in the most common experimental models of hepatic fibrosis. The characterization of cells, vessels and extracellular matrix and the identification of factors associated with endothelium (factor VIII RA), vascular basement membrane, other components of the vascular walls (actin, elastin) and the presence of the vascular-endothelial growth factor were investigated. The models examined included Capillaria hepatica septal fibrosis, whole pig serum injections, carbon tetrachloride administration, main bile duct ligation and Schistosoma mansoni infection. The first four models were performed in rats, while the last used mice. All models studied exhibited prominent angiogenesis. The most evident relationship between angiogenesis and fibrosis occurred with the C. hepatica model due to circumstances to be discussed. Special attention was paid to the presence of pericytes and to their tendency to become detached from the vascular wall and be transformed into myofibroblasts, which is a sequence of events that explains the decisive role angiogenesis plays in fibrosis.

Accuracy of phenotypic methicillin susceptibility methods in the detection of Staphylococcus aureus isolates carrying different SCCmec types

A total of 138 isolates, 118 methicillin-resistant Staphylococcus aureus (MRSA) isolates (staphylococcal cassette chromosome type II, 20 isolates, type III, 39 isolates and type IV, 59 isolates) and 20 methicillin-sensitive S. aureus isolates were evaluated by phenotypic methods: cefoxitin and oxacillin disk diffusion (DD), agar dilution (AD), latex agglutination (LA), oxacillin agar screening (OAS) and chromogenic agar detection. All methods showed 100% specificity, but only the DD tests presented 100% sensitivity. The sensitivity of the other tests ranged from 82.2% (OAS)-98.3% (AD). The LA test showed the second lowest sensitivity (86.4%). The DD test showed high accuracy in the detection of MRSA isolates, but there was low precision in the detection of type IV isolates by the other tests, indicating that the genotypic characteristics of the isolates should be considered.

Molecular characterization of G and P-types bovine rotavirus strains from Goiás, Brazil: high frequency of mixed P-type infections

In this study, 331 samples from calves less than one month old from a dairy herd in the district of Piracanjuba, state of Goiás, Brazil were tested for rotavirus. Thirty-three samples (9.9%) tested positive for rotavirus. Out of those, 31 were submitted to G and P characterization by reverse transcription followed by semi-nested polymerase chain reaction. Two samples were characterized as G6P[1], three as G10P[11] and five as G6P[11]. The majority of the samples (51.6%) displayed multiple P genotypes (P-genotype mixtures), including typical human genotypes P[4] and P[6M], suggesting the occurrence of co-infections and genetic reassortment. Also, the detection of human genotypes in bovine samples may be considered evidence of the zoonotic potential of rotaviruses. To our knowledge, this is the first report of such a high frequency of P genotype mixtures in bovine rotavirus samples. It also increases data on G and P rotavirus genotypes circulating in dairy herds in Brazil and can help in the development of more efficient immunization approaches, thereby controlling infection and reducing economical losses.

Sequence analysis of coding DNA fragments of pfcrt and pfmdr-1 genes in Plasmodium falciparum isolates from Odisha, India

The global emergence and spread of malaria parasites resistant to antimalarial drugs is the major problem in malaria control. The genetic basis of the parasite's resistance to the antimalarial drug chloroquine (CQ) is well-documented, allowing for the analysis of field isolates of malaria parasites to address evolutionary questions concerning the origin and spread of CQ-resistance. Here, we present DNA sequence analyses of both the second exon of the Plasmodium falciparum CQ-resistance transporter (pfcrt) gene and the 5' end of the P. falciparum multidrug-resistance 1 (pfmdr-1) gene in 40 P. falciparum field isolates collected from eight different localities of Odisha, India. First, we genotyped the samples for the pfcrt K76T and pfmdr-1 N86Y mutations in these two genes, which are the mutations primarily implicated in CQ-resistance. We further analyzed amino acid changes in codons 72-76 of the pfcrt haplotypes. Interestingly, both the K76T and N86Y mutations were found to co-exist in 32 out of the total 40 isolates, which were of either the CVIET or SVMNT haplotype, while the remaining eight isolates were of the CVMNK haplotype. In total, eight nonsynonymous single nucleotide polymorphisms (SNPs) were observed, six in the pfcrt gene and two in the pfmdr-1 gene. One poorly studied SNP in the pfcrt gene (A97T) was found at a high frequency in many P. falciparum samples. Using population genetics to analyze these two gene fragments, we revealed comparatively higher nucleotide diversity in the pfcrt gene than in the pfmdr-1 gene. Furthermore, linkage disequilibrium was found to be tight between closely spaced SNPs of the pfcrt gene. Finally, both the pfcrt and the pfmdr-1 genes were found to evolve under the standard neutral model of molecular evolution.

Phylogeny and circumscription of Sapindaceae revisited: molecular sequence data, morphology and biogeography support recognition of a new family, Xanthoceraceae

Background and aims Recent studies have adopted a broad definition of Sapindaceae that includes taxa traditionally placed in Aceraceae and Hippocastanaceae, achieving monophyly but yielding a family difficult to characterize and for which no obvious morphological synapomorphy exists. This expanded circumscription was necessitated by the finding that the monotypic, temperate Asian genus Xanthoceras, historically placed in Sapindaceae tribe Harpullieae, is basal within the group. Here we seek to clarify the relationships of Xanthoceras based on phylogenetic analyses using a dataset encompassing nearly 3/4 of sapindaceous genera, comparing the results with information from morphology and biogeography, in particular with respect to the other taxa placed in Harpullieae. We then re-examine the appropriateness of maintaining the current broad, morphologically heterogeneous definition of Sapindaceae and explore the advantages of an alternative family circumscription. Methods Using 243 samples representing 104 of the 142 currently recognized genera of Sapindaceae s. lat. (including all in Harpullieae), sequence data were analyzed for nuclear (ITS) and plastid (matK, rpoB, trnD-trnT, trnK-matK, trnL-trnF and trnS-trnG) markers, adopting the methodology of a recent family-wide study, performing single-gene and total evidence analyses based on maximum likelihood (ML) and maximum parsimony (MP) criteria, and applying heuristic searches developed for large datasets, viz, a new strategy implemented in RAxML (for ML) and the parsimony ratchet (for MP). Bootstrap analyses were performed for each method to test for congruence between markers. Key results Our findings support earlier suggestions that Harpullieae are polyphyletic: Xanthoceras is confirmed as sister to all other sampled taxa of Sapindaceae s. lat.; the remaining members belong to three other clades within Sapindaceae s. lat., two of which correspond respectively to the groups traditionally treated as Aceraceae and Hippocastanaceae, together forming a clade sister to the largely tropical Sapindaceae s. str., which is monophyletic and morphologically coherent provided Xanthoceras is excluded. Conclusion To overcome the difficulties of a broadly circumscribed Sapindaceae, we resurrect the historically recognized temperate families Aceraceae and Hippocastanaceae, and describe a new family, Xanthoceraceae, thus adopting a monophyletic and easily characterized circumscription of Sapindaceae nearly identical to that used for over a century.

Full-length genomic sequence of hepatitis B virus genotype C2 isolated from a native Brazilian patient

The hepatitis B virus (HBV) is among the leading causes of chronic hepatitis, cirrhosis and hepatocellular carcinoma. In Brazil, genotype A is the most frequent, followed by genotypes D and F. Genotypes B and C are found in Brazil exclusively among Asian patients and their descendants. The aim of this study was to sequence the entire HBV genome of a Caucasian patient infected with HBV/C2 and to infer the origin of the virus based on sequencing analysis. The sequence of this Brazilian isolate was grouped with four other sequences described in China. The sequence of this patient is the first complete genome of HBV/C2 reported in Brazil.

Sequence analysis of the 2009 pandemic influenza A H1N1 virus haemagglutinin gene from 2009-2010 Brazilian clinical samples

In this paper, we analysed the haemagglutinin (HA) gene identified by polymerase chain reaction from 90 influenza A H1N1 virus strains that circulated in Brazil from April 2009-June 2010. A World Health Organization sequencing protocol allowed us to identify amino acid mutations in the HA protein at positions S220T (71%), D239G/N/S (20%), Y247H (4.5%), E252K (3.3%), M274V (2.2%), Q310H (26.7%) and E391K (12%). A fatal outcome was associated with the D239G mutation (p < 0.0001). Brazilian HA genetic diversity, in comparison to a reference strain from California, highlights the role of influenza virus surveillance for study of viral evolution, in addition to monitoring the spread of the virus worldwide.

Letrozole therapy alone or in sequence with tamoxifen in women with breast cancer.

BACKGROUND: The aromatase inhibitor letrozole, as compared with tamoxifen, improves disease-free survival among postmenopausal women with receptor-positive early breast cancer. It is unknown whether sequential treatment with tamoxifen and letrozole is superior to letrozole therapy alone. METHODS: In this randomized, phase 3, double-blind trial of the treatment of hormone-receptor-positive breast cancer in postmenopausal women, we randomly assigned women to receive 5 years of tamoxifen monotherapy, 5 years of letrozole monotherapy, or 2 years of treatment with one agent followed by 3 years of treatment with the other. We compared the sequential treatments with letrozole monotherapy among 6182 women and also report a protocol-specified updated analysis of letrozole versus tamoxifen monotherapy in 4922 women. RESULTS: At a median follow-up of 71 months after randomization, disease-free survival was not significantly improved with either sequential treatment as compared with letrozole alone (hazard ratio for tamoxifen followed by letrozole, 1.05; 99% confidence interval [CI], 0.84 to 1.32; hazard ratio for letrozole followed by tamoxifen, 0.96; 99% CI, 0.76 to 1.21). There were more early relapses among women who were assigned to tamoxifen followed by letrozole than among those who were assigned to letrozole alone. The updated analysis of monotherapy showed that there was a nonsignificant difference in overall survival between women assigned to treatment with letrozole and those assigned to treatment with tamoxifen (hazard ratio for letrozole, 0.87; 95% CI, 0.75 to 1.02; P=0.08). The rate of adverse events was as expected on the basis of previous reports of letrozole and tamoxifen therapy. CONCLUSIONS: Among postmenopausal women with endocrine-responsive breast cancer, sequential treatment with letrozole and tamoxifen, as compared with letrozole monotherapy, did not improve disease-free survival. The difference in overall survival with letrozole monotherapy and tamoxifen monotherapy was not statistically significant. (ClinicalTrials.gov number, NCT00004205.)

Brazilian clinical trial of uniform multidrug therapy for leprosy patients: the correlation between clinical disease types and adverse effects

This study sought to verify the correlation between leprosy types and the adverse effects of treatment drugs. This quantitative, prospective, nested study was developed at the Dona Libânia Dermatology Centre in Fortaleza, Brazil. Data were collected from November 2007-November 2008. During this period, 818 leprosy patients were diagnosed and began treatment. Forty patients with tuberculoid leprosy (TT) were selected. Twenty patients followed a standard therapy of dapsone and rifampicin and 20 were administered dapsone, rifampicin and clofazimine (U-MDT). Twenty patients with borderline lepromatous (BL) and lepromatous leprosy (LL) were also selected and treated with U-MDT. All of the subjects received six doses. With the exception of haemolytic anaemia, there was a low incidence of adverse effects in all the groups. We did not observe any differences in the incidence of haemolytic anaemia or other side effects across groups of patients with TT, BL or LL treated with U-MDT.

[23 phot., vues et types du gouvernement d'Arkhangel, par I. Leitsinger, don A.V. Grigoriev en 1887]

Donateur : Grigoriev, Alexandre Vasiliévitch (1848-19..?)

An integrated genetic and functional analysis of the role of type II transmembrane serine proteases (TMPRSSs) in hearing loss.

Building on our discovery that mutations in the transmembrane serine protease, TMPRSS3, cause nonsyndromic deafness, we have investigated the contribution of other TMPRSS family members to the auditory function. To identify which of the 16 known TMPRSS genes had a strong likelihood of involvement in hearing function, three types of biological evidence were examined: 1) expression in inner ear tissues; 2) location in a genomic interval that contains a yet unidentified gene for deafness; and 3) evaluation of hearing status of any available Tmprss knockout mouse strains. This analysis demonstrated that, besides TMPRSS3, another TMPRSS gene was essential for hearing and, indeed, mice deficient for Hepsin (Hpn) also known as Tmprss1 exhibited profound hearing loss. In addition, TMPRSS2, TMPRSS5, and CORIN, also named TMPRSS10, showed strong likelihood of involvement based on their inner ear expression and mapping position within deafness loci PKSR7, DFNB24, and DFNB25, respectively. These four TMPRSS genes were then screened for mutations in affected members of the DFNB24 and DFNB25 deafness families, and in a cohort of 362 sporadic deaf cases. This large mutation screen revealed numerous novel sequence variations including three potential pathogenic mutations in the TMPRSS5 gene. The mutant forms of TMPRSS5 showed reduced or absent proteolytic activity. Subsequently, TMPRSS genes with evidence of involvement in deafness were further characterized, and their sites of expression were determined. Tmprss1, 3, and 5 proteins were detected in spiral ganglion neurons. Tmprss3 was also present in the organ of Corti. TMPRSS1 and 3 proteins appeared stably anchored to the endoplasmic reticulum membranes, whereas TMPRSS5 was also detected at the plasma membrane. Collectively, these results provide evidence that TMPRSS1 and TMPRSS3 play and TMPRSS5 may play important and specific roles in hearing.

New human kallikrein 14: enzymatic characterization and inhibitors development.

RESUME DESTINE A UN LARGE PUBLIC En biologie, si une découverte permet de répondre à quelques questions, en général elle en engendre beaucoup d'autres. C'est ce qui s'est produit récemment dans le monde des kallicréines. De la famille des protéases, protéines ayant la faculté de couper plus ou moins spécifiquement d'autres protéines pour exercer un rôle biologique, la famille des kallicréines humaines n'était composée que de 3 membres lors du siècle dernier. Parmi eux, une kallicréine mondialement utilisée pour détecter le cancer de la prostate, le PSA. En 2000, un chercheur de l'hôpital universitaire Mont Sinaï à Toronto, le Professeur Eleftherios Diamandis, a découvert la présence de 12 nouveaux gènes appartenant à cette famille, situés sur le même chromosome que les 3 premières kallicréines. Cette découverte majeure a placé les spécialistes des kallicréines face à une montagne d'interrogations car les fonctions de ces nouvelles protéases étaient totalement inconnues. La kallicréine humaine 14 (hK14) présente un intérêt particulier, car elle se retrouve associée à différents cancers, notamment les carcinomes ovariens et mammaires. Cette association ne répond cependant pas à la fonction de cette protéase. L'objectif de ce travail de thèse était donc de découvrir, dans un premier temps, la spécificité de cette nouvelle kallicréine, c'est-à-dire le type de coupure qu'elle engendre au niveau des protéines qu'elle cible. Utilisant une technologie de pointe qui exploite la propriété des bactériophages à se répliquer dans les bactéries à l'infini, des dizaines de millions de combinaisons protéiques aléatoires ont été présentées à hK14, qui a pu sélectionner celles qui lui étaient favorables pour la coupure. Cette technique qualitative porte le nom de Phage Display Substrate. Une fois la sélection réalisée, il fallait transférer ces séquences coupées ou substrats dans un système permettant de donner une valeur quantitative à l'efficacité de coupure. Pour cela nous avons développé une technologie qui permet d'évaluer cette efficacité en utilisant des protéines fluorescentes de méduse, modifiées génétiquement, dont l'excitation de la première (CFP : cyan fluorescent protein) par la lumière à une certaine longue d'onde permet le transfert d'énergie à la seconde (YFP : yellow fluorescent protein), via un substrat qui les lie. Pour que ce transfert d'énergie se produise, il faut que les deux protéines fluorescentes soient proches, comme c'est le cas lorsqu'elles sont liées par un substrat. La coupure de ce lien provoque un changement de transfert d'énergie qui est quantifiable en utilisant un spectrofluoromètre. Cette technologie permet donc de suivre la réaction d'hydrolyse (coupure) des protéases. Afin de poursuivre certaines expériences permettant de mieux comprendre la fonction biologique d'hK14 ainsi que son éventuelle implication dans le cancer, nous avons développé des inhibiteurs spécifiques d'hK14. Les séquences qui on été le plus efficacement coupées par hK14 ont été utilisées pour transformer deux types d'inhibiteurs classiques, qui circulent dans notre sang, en inhibiteurs d'hK14 hautement efficaces et spécifiques. Selon les résultats obtenus in vitro, ils pourront être évalués in vivo en tant que traitement potentiel contre le cancer. RESUME Les protéases sont des enzymes impliquées dans des processus physiologiques mais aussi parfois pathologiques. La famille des kallicréines tissulaires humaines représente le plus grand groupe de protéases humaines, dont plusieurs pourraient participer au développement de certaines maladies. D'autre part, ces protéases sont apparues comme des marqueurs de pathogénicité potentiels, notamment dans les cas de cancers hormono-dépendants. La kallicréine humaine 14 a été récemment découverte et son implication dans quelques maladies, particulièrement dans le cas de tumeurs, semble probable. En effet, son expression génique est augmentée au niveau des tissus cancéreux de la prostate et du sein et son expression protéique s'est révélée plus élevée dans le sérum de patientes atteintes d'un cancer du sein ou des ovaires. Cependant, comme c'est le cas pour la plupart des kallicréines, sa fonction est encore inconnue. Afin de mieux connaître son rôle biologique et/ou pathologique, nous avons décidé de caractériser son activité enzymatique. Nous avons tout d'abord mis au point un système de substrats entièrement biologique permettant d'étudier in vitro l'activité des protéases. Ce système est basé sur le phénomène de FRET, à savoir le transfert d'énergie de résonance fluorescente qui intervient entre deux molécules fluorescentes voisines si le spectre d'émission de la protéine donneuse chevauche le spectre d'excitation de la protéine receveuse. Nous avons fusionné de manière covalente une protéine fluorescente bleue (CFP) et une jaune (YFP) en les liant avec diverses séquences. Par clivage de la séquence de liaison, une perte du transfert d'énergie peut être mesurée par un spectrofluoromètre. Cette technologie représente un moyen facile de suivre la réaction d'hydrolyse des protéases. Les conditions optimales de production de ces substrats CFP-YFP ont été déterminées, de même que les paramètres pouvant éventuellement influencer le FRET. Ce système possède une grande résistance à la protéolyse non spécifique et est applicable à un grand nombre de protéase. Contrairement aux substrats fluorogéniques, il permet d'étudier les acides aminés se trouvant des deux côtés du site de clivage. Ce système étant entièrement biologique, il est le reflet des interactions protéine-protéine et représente un outil biologique facile, bon marché et rapide pour caractériser les protéases. Dans un premier temps, hK14 a été mise en présence d' une banque de haute diversité de pentapeptides aléatoires présentée à la surface de phages afin d'identifier des substrats spécifiques. Ensuite, le système CFP-YFP a été employé pour trier les peptides sélectionnés afin d'identifier les séquences de substrats les plus sensibles et spécifiques pour hK14. Nous avons montré, qu'en plus de sa prévisible activité de type trypsine, hK14 possède aussi une très surprenante activité de type chymotrypsine. Les séquences les plus sensibles ont été choisies pour cribler la banque de donnée Swissprot, permettant ainsi l'identification de 6 substrats protéiques humains potentiels pour hK14. Trois d'entre eux, la laminine α-5, le collagène IV et la matriline-4, qui sont des composants de la matrice extracellulaire, ont démontré une grande susceptibilité à l'hydrolyse par hK14. De plus, la séparation éléctrophorétique a montré que la dégradation de la laminine α-5 et de la matriline-4 par hK14 devait se produire aux sites identifiés par la technologie du phage display. Pour terminer, nous avons transformé, par mutagenèse dirigée, deux serpines (inhibiteurs de protéases de type sérine) connues, AAT et ACT (alpha anti-trypsine et alpha anti-chymotrypsine), qui inhibent un vaste éventail d'enzymes humaines en inhibiteurs d'hK14 hautement efficaces et spécifiques. Ces inhibiteurs pourront être utilisés d'une part pour poursuivre certaines expériences permettant de mieux comprendre l'implication d'hK14 dans des voies physiologiques ou dans le cancer et d'autre part pour les évaluer in vivo en tant que traitement potentiel contre le cancer. SUMMARY Proteases consist of enzymes involved in physiological events, but also, in case of dysregulation, in pathogenicity. The human tissue kallikrein family represents the largest human protease cluster and includes several members that either could participate in the course of certain diseases or emerged as potential biological markers, especially in hormone dependent cancers. The human kallikrein 14 has been recently discovered and suggested implications in some disorders, particularly in tumors since its gene expression is up-regulated in prostate and breast cancer tissues and its protein expression increased in the serum of patients with breast and ovarian cancers. However, like most kallikreins, its function remains unknown. To better understand hK14 biological and/or pathological role, we decided to characterize its enzymatic activity. First of all, we developped a biological system suitable for in vitro study of protease activity. This system is based on the so-called FRET phenomenon, that is the Fluorescence Resonance Energy Transfer that occurs between two nearby fluorescent proteins if the emission spectrum of the donor overlaps the excitation spectrum of the acceptor. We fused covalently a cyan fluorescent protein (CFP) and a yellow fluorescent protein (YFP) with diverses sequences. Upon cleavage of the linker sequence by protease, the loss of energy transfer can be measured by a spectrofluorometer allowing an easy following of hydrolysis reaction. The optimal conditions to produce in bacterial system these CFP-YFP substrates were determined as well as the parameters that could eventually influence the FRET. This system demonstrated a high degree of resistance to non-specific proteolysis and applicability to various conditions corresponding to a great number of existing proteases. Other avantages are the possibility to study the amino acids located both sides of the cleavage site as well as the interest to work in a full biological system reflecting protein-protein interaction. A phage substrate library with exhaustive diversity was used prior to CFP-substrate-YFP system to isolate specific human kallikrein 14 substrates. After that the CFP-YFP system was used to sort peptides and identify highly sensitive and specific substrate sequences for hK14. We showed that besides its predictable trypsin-like activity, hK14 also possesses a surprising chymotrypsin-like activity. The screening of the Swissprot database was achieved with the most sensitive sequences and allowed the identification of 6 potential human protein substrates for hK14. Three of them, laminin α-5, collagen IV and matrilin-4, which are components of the extracellular matrix were incubated with hK14, by which they were efficiently hydrolyzed. Moreover, electrophoretic separation revealed that degradation of laminin α-5 and matrilin-4 by hK14 generated fragments with identical molecular size than the predicted N-terminal fragments that would result from hK14 specific cleavage, proving the value of phage display substrate to identify potential substrates. Finally, with site-directed mutagenesis, we transformed two well-known serpins (serine protease inhibitors), AAT and ACT (alpha anti-trypsin and alpha anti-chymotrypsin), which inhibit a vast spectrum of human enzymes into highly efficient and specific hK14 inhibitors. These inhibitors will be used to pursue experiments that could help understand hK14 implication in physiological pathways as well as in cancer biology and also to perform their in vivo evalution as potential cancer treatment.

Whole-cell antigenicity data support sequence-based kinetoplastid taxonomy

Early immunological data, obtained by immunodiffusion and immunoelectrophoresis, on the whole-cell antigenicity of kinetoplastid protozoa were retrieved and used to construct a dendrogram of antigenic distances. Remarkably, they supported the same taxonomic conclusions as analyses based on DNA and protein sequence data.