First Report of a Decline and Wilt of Young Olive Trees Caused by Simultaneous Infections of Verticillium dahliae and Phytophthora palmivora in Sicily

In summer 2008, leaf chlorosis, defoliation, exceptional fruit set, twig dieback, and wilt were observed on 4-year-old olive (Olea europea L.) trees cv. Tonda Iblea in a drip-irrigated orchard in eastern Sicily. Rot of fine roots was associated with these symptoms and on ~15% of symptomatic trees rot extended to the crown and basal stem. Trees declined slowly or collapsed suddenly with withered leaves still attached. Incidence of affected trees was ~10%. A fungus identified as Verticillium dahliae Kleb. was isolated from the xylem of main roots and basal stem. An oomycete identified as Phytophthora palmivora (Butler) Butler was isolated from roots and basal trunk bark. Both pathogens were recovered from symptomatic trees with mean frequency of positive isolations per tree of 80 and 30% for V. dahliae and P. palmivora, respectively. To isolate V. dahliae, wood chips were surface disinfested in 0.5% NaOCl for 1 min and plated onto potato dextrose agar (PDA). The fungus was identified on the basis of microsclerotia, verticillate arrangement of phialides on conidiophores, and hyaline single-celled conidia. Ten monoconidial isolates were characterized by PCR using primer pairs INTND2f/INTND2r and DB19/espdef01 (3). Only 824-bp amplicons, diagnostic of the virulent, nondefoliating V. dahliae pathotype, were obtained. P. palmivora was isolated on selective medium (2) and pure cultures were obtained by single-hypha transfers. Colonies grew on PDA between 10 and 35°C (optimum at 27°C). Chlamydospores and elliptical to ovoid, papillate, caducous (mean pedicel length = 5 μm) sporangia (length/breadth ratio of 1.8) were produced on V8 juice agar. All isolates were paired with reference isolates of P. nicotianae and produced gametangia only with isolates of the A₂ mating type. PCR amplicons of a representative isolate generated using primers ITS 6 and ITS 4 (1) were sequenced and found to be identical to those of a reference isolate of P. palmivora (GenBank No. AY208126). Pathogenicity of V. dahliae (IMI 397476) and P. palmivora (IMI 397475) was tested on 6-month-old rooted cuttings of olive cv. Tonda Iblea. Ten cuttings were transplanted into pots with steam-sterilized soil and inoculum of P. palmivora (4% vol/vol) produced on wheat kernels. Ten olive cuttings were inoculated with V. dahliae by injecting the stem with 150 μl of a conidial suspension (10⁷ conidia ml^-1) and 10 cuttings were stem inoculated with V. dahliae and transplanted into soil infested with P. palmivora. Controls were 10 noninoculated cuttings transplanted into steam-sterilized soil. Pots were kept in a greenhouse (25 ± 3°C) for 4 months. No aerial symptoms were observed on cuttings transplanted into soil infested with P. palmivora. However, root dry weight was reduced by 40% in comparison with the controls. Cuttings inoculated solely with V. dahliae had a 15% reduction in height compared with the controls but only four cuttings wilted. All cuttings inoculated with P. palmivora and V. dahliae wilted, indicating a synergism between the two pathogens. Controls remained healthy. Each pathogen was reisolated solely from inoculated cuttings and both pathogens were reisolated from cuttings with double inoculations. A similar syndrome 'seca' (drying) was reported in Spain (4). References: (1) D. E. L. Cooke et al. Fungal Genet. Biol. 30:17, 2000. (2) H. Masago et al. Phytopathology 67:425, 1977. (3) J. Mercado-Blanco et al. Plant Dis. 87:1487, 2003. (4) M. E. Sánchez-Hernández et al. Eur. J. Plant Pathol. 104:34, 1998.

Ultrasound in the evaluation of interstitial pneumonia

BACKGROUND

The diagnostic value of thoracic ultrasonography (US) has recently increased. Skilled sonographers with experience in pulmonary medicine have demonstrated the existence of US signs of chest pathology.

PURPOSE

To detect US findings associated with infectious interstitial pneumonia that can be used to supplement other diagnostic tools.

MATERIALS AND METHODS

Over a period of 5 years (2001-2006), 55 patients were referred to our ultrasonography units for evaluation of probable viral or viral-like infections of the respiratory tract. Each patient was subjected to a work-up that included clinical examination, blood tests, pulmonary function tests, bronchoscopy, chest radiographs, high-resolution computed tomography (HRCT), and thoracic US, which was performed under blinded conditions.

RESULTS

Based on the findings that emerged from the work-up described above, all 55 patients were diagnosed with interstitial pneumonia. Evaluation of the US scans for the signs of interstitial lung disease described by Lichtenstein revealed "comet-tail" artifacts in the anterolateral lung fields in 31 (56.36%) patients and mixed patterns consisting in increased density associated with ring-down artifacts in 24 (46.64%). Pleural involvement was also observed in 34 cases (61.82%).

CONCLUSIONS

Thoracic US appears to be a useful adjunct to clinical, laboratory and radiological studies in patients suspected of having infectious interstitial pneumonia.

[Update on HIV infection in the province of Cosenza. HIV infections and respiratory disease]

The aim of the present study was to evaluate the incidence of HIV infection and concomitant pathologies, paying special attention to those involving the respiratory tract, in the Province of Cosenza through a retrospective study of patients monitored by the Divisions of Infectious Diseases and Pneumology with the collaboration of the Virology Unit of the United Hospitals of Cosenza. The results obtained show that there is a lower incidence of AIDS and HIV-correlated respiratory pathologies in this area compared to the rest of Italy but, in spite of this, the authors highlight the need in Calabria for those centres and structures that have been planned but never completely realised (Law 135/90; DPR 7/4/94; etc.) which would enable infected subjects to be identified and the necessary measures for prevention, diagnosis and treatment to be implemented.

[The lung in AIDS]

The aim of this study was to underline the important role played by respiratory tract pathologies in HIV-infected subjects and to evaluate the incidence of respiratory pathologies in HIV-positive subjects in the province of Cosenza. After examining recently reported data, the authors analyse the patients studied by the Infectious Disease and Pneumology Divisions of the United Hospitals of Cosenza with the collaboration of the Virology Unit over the two-year period 1992-1994. As well as the lower incidence of HIV infection in this area compared to the rest of Italy, the paper highlights the reduced percentage of concomitant respiratory pathologies. The authors attempt to interpret the significance of these results.