First Report of Natural Infection by "Candidatus Phytoplasma brasiliense" in Catharanthus roseus

Catharanthus roseus (L.) G. Don (periwinkle) is well known as an experimental host for diverse phytoplasmas that are artificially transmitted to it through the use of dodder (Cuscuta sp.), laboratory vector insects, or grafting. However, few phytoplasma taxa have been reported in natural infections of C. roseus, and the role of C. roseus in phytoplasma dissemination and natural disease spread is not clear. In this study, naturally diseased plants of C. roseus exhibiting yellowing and witches' broom symptoms indicative of phytoplasma infection were observed throughout the year in the state of Rio de Janeiro, Brazil. Shoots and leaves of four diseased plants were assayed for the presence of phytoplasma DNA sequences by nested polymerase chain reactions (PCR) as previously described (2,3). Phytoplasma rDNA was amplified from diseased periwinkle plants in PCR primed by primer pair P1/P7 and was reamplified in nested PCR primed by primer pair R16F2n/R16R2 (F2n/R2). The results indicated the presence of phytoplasma in all four diseased plants. Phytoplasma identification was accomplished by restriction fragment length polymorphism (RFLP) analysis, using 11 restriction enzymes, of 16S rDNA amplified in PCR primed by F2n/R2. Phytoplasmas were classified according to the system of Lee et al. (1). On the basis of collective RFLP patterns of 16S rDNA, the phytoplasma infections in the four periwinkle plants could not be distinguished from one another. Furthermore, the collective RFLP patterns were indistinguishable from those reported previously for hibiscus witches' broom phytoplasma, "Candidatus Phytoplasma brasiliense" (2). The phytoplasma found in C. roseus, designated strain HibWB-Cr, was classified in group 16SrXV (hibiscus witches' broom phytoplasma group). HibWB-Cr is tentatively considered a new strain of "Ca. P. brasiliense". C. roseus is the first known, naturally diseased alternate plant host of "Ca. P. brasiliense". The present study identified strain HibWB-Cr in Rio de Janeiro State, where hibiscus witches' broom disease is prevalent (2). How this economically important disease of hibiscus spreads is not known. Our findings raise the possibility that a polyphagous insect vector is involved in the natural transmission of "Ca. P. brasiliense" and that C. roseus or other plant species serve as reservoirs for the spread of this phytoplasma taxon. References: (1) I.-M. Lee et al. Int. J. Syst. Bacteriol. 48:1153, 1998. (2) H. G. Montano et al. Int. J. Syst. Evol. Microbiol. 51:1109, 2001. (3) H. G. Montano et al. Plant Dis. 84:429, 1999.

'Candidatus Phytoplasma brasiliense', a new phytoplasma taxon associated with hibiscus witches' broom disease

Hibiscus rosa-sinensis is a valuable ornamental species widely planted in Brazil. Many plants are affected by witches' broom disease, which is characterized by excessive axillary branching, abnormally small leaves, and deformed flowers, symptoms that are characteristic of diseases attributed to phytoplasmas. A phytoplasma was detected in diseased Hibiscus by amplification of rRNA operon sequences by PCRs, and was characterized by RFLP and nucleotide sequence analyses of 16S rDNA. The collective RFLP patterns of amplified 16S rDNA differed from the patterns described previously for other phytoplasmas. On the basis of the RFLP patterns, the hibiscus witches' broom phytoplasma was classified in a new 16S rRNA RFLP group, designated group 16SrXV. A phylogenetic analysis of 16S rDNA sequences from this and other phytoplasmas identified the hibiscus witches' broom phytoplasma as a member of a distinct subclade (designated subclade xiv) of the class Mollicutes. A phylogenetic tree constructed on the basis of 16S rRNA gene sequences was consistent with the hypothesis that there was divergent evolution of hibiscus witches' broom phytoplasma and its closest relatives (members of 16S rRNA RFLP group 16SrII) from a common ancestor. On the basis of unique properties of the DNA from hibiscus witches' broom phytoplasma, it is proposed that it represents a new taxon, namely 'Candidatus Phytoplasma brasiliense'.

Identification and Phylogenetic Analysis of a New Phytoplasma from Diseased Chayote in Brazil

Chayote (Sechium edule) (Cucurbitaceae), also known as vegetable pear, mirliton, or mango squash, is a commercially important vegetable crop in Brazil, where it is affected by chayote witches'-broom disease. Affected plants exhibit witches'-broom growths and other symptoms characteristic of plant diseases caused by phytoplasmas. Since previous electron microscopic studies revealed the association of a phytoplasma with chayote witches'-broom, the present work was aimed at detecting and classifying the phytoplasma that may be the causal agent of the disease. Strains of a phytoplasma belonging to group 16SrIII (X-disease phytoplasma group) were discovered in chayote affected by witches'-broom disease and in diseased plants of Momordica charantia that were growing as weeds in fields of chayote in Brazil. On the basis of results from restriction fragment length polymorphism and nucleotide sequence analyses of 16S rDNA, the phytoplasma was classified in a new subgroup, designated subgroup III-J. This classification was supported by a phylogenetic tree constructed by the Neighbor-Joining method.

Therapy of post-renal transplantation hyperlipidaemia: comparative study with simvastatin and fish oil

BACKGROUND

Recipients of renal transplantation (RT) exhibit disturbances of serum lipids and apoproteins that may contribute to their cardiovascular morbidity and mortality. In our renal transplant department the hypercholesterolaemia prevalence at the first and fifth year of RT is 70.0% and 81.2%, respectively. Lipid-lowering therapy has been utilized in many Transplant Units. The aim of our study was to evaluate post-RT hyperlipidaemia control with simvastatin or fish oil.

METHODS

Forty-three RT patients (26 men and 17 women) with persistent hypercholesterolaemia and stable graft function which were resistant to a lipid-lowering diet (American Heart Association Step Two) were randomized into two groups and treated for 3 months with simvastatin (S) (10mg/day; n = 25) and fish oil (F) (6 g/day; n = 18). Total cholesterol (TC), LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C), lipoprotein a (Lp(a)), apolipoprotein A1 (Apo A1), and apolipoprotein B (Apo B) were monitored and at the study baseline they were similar between the two groups.

RESULTS

No side effects were detected after 3 months of therapy. In group S, the concentrations of TC (271 +/- 46 mg% vs 228 +/- 49 mg%; P < 0.001), TG (180 +/- 78 vs 134 +/- 45; P < 0.01), LDL-C (177 +/- 40 vs 144 +/- 43; P < 0.01) and Apo B (96 +/- 18 vs 82 +/- 16; P < 0.001) were significantly reduced, and Apo A1 concentration had increased (135 +/- 24 vs 149 +/- 30; P < 0.01). In group F, the concentrations of TC (266 +/- 25 vs 240 +/- 31; P < 0.001), TG (203 +/- 105 vs 156 +/- 72; P = 0.02) and HDL-C (63 +/- 15 vs 53 +/- 12; P < 0.01) were significantly reduced.

CONCLUSIONS

We concluded that low-dose simvastatin and fish oil are both effective and safe in correcting post-RT hyperlipidaemia. Further prospective studies with larger follow-up are needed to clarify whether this therapy has an impact on cardiovascular morbidity and mortality in RT patients.

Maternal and perinatal implications of the use of human recombinant erythropoietin

BACKGROUND

The use of human recombinant erythropoietin (rHuEPO) in pregnant patients has been limited by the fear of eventual maternal and fetal repercussions (either direct or indirect).

METHODS

The authors present their experience with the use of rHuEPO during pregnancy, with two pregnant women with kidney transplants and in three others with chronic renal insufficiency (one with diabetic nephropathy, another dialysis dependent), all with hematocrit below 30% and adequate iron reserves.

RESULTS

Three of the patients had needed blood transfusions before beginning therapy, and another needed transfusion after significant metrorrhagia. The length of the treatment varied between 2 and 23 weeks and the hematocrit at delivery varied between 26% and 36%. Secondary effects (appearance or worsening of hypertension and seizures) were nil. There was one fetal death at 23 weeks of pregnancy (following an abruptio placenta), two neonates weighing between the 5th and the 10th percentiles, and three needing phototherapy (1 to 2 days). One year after birth, all showed a normal ponderal and neurologic development.

CONCLUSIONS

Among the cases presented, no maternal and perinatal complications attributable to rHuEPO were registered. It is important that institutions report their experiences with the use of rHuEPO, given its restrictive indications and the limited experience of each institution.