[Clinical analysis of the specific reference intervals of thyroid index for normal pregnant women].

Objective: To explore the reference intervals of thyrotropin (TSH) and free thyroxine (FT(4)) in normal pregnant women. Methods: Prospective and longitudinal sequential collection of the cases were performed. A total of 155 singleton pregnant women who had regular prenatal examination and delivery in West China Second Hospital of Sichuan University from January 2015 to December 2015 were included as the research group. Blood samples were sequentially collected from the pregnant women at the first (9-13(+6) weeks) , the second (24-27(+6) weeks) , the third (32-36 weeks) trimesters, respectively. Another 155 non-pregnant women were selected as the control group simultaneously, in an effort to establish a range of reference intervals of thyroid index in each period of pregnancy. Meanwhile, neonatal plantar blood were also collected on special filter paper and TSH levels were measured. Results: (1) TSH reference intervals [percentile 2.5-percentile 97.5 (P(2.5)-P(97.5)) ] were 0.08-3.29 mU/L, 0.59-4.22 mU/L and 0.81-4.33 mU/L in three trimesters respectively. FT(4) reference intervals were 11.88-20.06 pmol/L, 9.89-15.80 pmol/L and 9.22-15.77 pmol/L in three trimesters respectively. (2) The median serum TSH in the first trimester (1.35 mU/L) was lower than that in the second trimester (2.15 mU/L) , the third trimester (2.19 mU/L) , and the control group (2.19 mU/L) . The differences were all statistically significant (P<0.05) . There was no significant difference in median serum TSH between the second trimester and the third trimester, the second trimester and the control group, and the third trimester versus the control group. (3) The median serum FT(4) in the first trimester (15.16 pmol/L) was higher than that in the second trimester (12.39 pmol/L) and the third trimester (12.26 pmol/L) . The differences were both statistically significant (P<0.05) . The median FT(4) in the second trimester and the third trimester was lower than that in the control group (15.64 pmol/L) , and the differences were both statistically significant (P<0.05) . (4) In the first trimester, the median serum total triiodothyronine (TT(3)) level (2.32 nmol/L) was higher than that in the control group (1.56 nmol/L) , total thyroxine (TT(4)) level (154.60 nmol/L) was also higher than that in the control group (98.25 nmol/L) , and free triiodothyronine (FT(3)) level (4.70 pmol/L) was lower than that in the control group (4.84 pmol/L) , the differences were all statistically significant (P<0.05) . (5) The TSH levels of all neonatus were normal [ (2.1±1.3) mU/L]. Conclusions: The thyroid hormone levels between pregnant women and non-pregnant women are significantly different. Moreover, the reference intervals are vary with pregnancy period. It is important to establish the specific reference intervals of thyroid hormones in the first, second and third trimester of pregnancy specific to local region or unit.

Association of genetic variations in miR-146a rs2910164 and miR-149 rs11614913 with the development of classic Kaposi sarcoma.

Classic Kaposi sarcoma is a type of vascular proliferative inflammatory disease. Previous studies have reported significant associations between microRNAs expression and the development of classic Kaposi sarcoma. Here, we conducted a case-control study to investigate the association between miR-146a and miR-149 genetic polymorphisms and risk of classic Kaposi sarcoma in a Chinese population. Both classic Kaposi sarcoma patients and healthy controls were recruited between December 2013 and October 2015. Genotyping of miR-146a and miR-149 was performed by polymerase chain reaction-coupled with restriction fragment length polymorphism. Results showed that the GG genotype of miR-146a was associated with increased risk to classic Kaposi sarcoma (OR = 6.00, 95%CI = 1.19-30.12), as compared with the CC genotype. In the recessive model, we found that the GG genotype carried a 4.55-fold increased risk to classic Kaposi sarcoma as compared with the CC + CG genotype (OR = 2.06, 95%CI = 1.04-20.29). In conclusion, our study demonstrated that miR-146a, but not miR-149 polymorphism, is associated with risk to classic Kaposi sarcoma in the Chinese population.

Analysis of KIT mutations and c-KIT expression in Chinese Uyghur and Han patients with melanoma.

BACKGROUND: The KIT gene plays an important role in the pathogenesis of malignant melanoma (MM). In recent years, activating mutations in KIT have been recognized as oncogenic. A number of therapies have been established, which provide significant clinical benefits for patients with MM with KIT mutations. Thus, detection of KIT mutations can have profound therapeutic implications. AIM: To investigate KIT gene expression in MMs in Chinese Uyghur and Han patients with mutations in KIT, and to identify the clinical features associated with KIT mutations and c-KIT expression. METHODS: In total, 105 MMs (56 from Uyghur and 49 from Han patients) were selected from patients in the Uyghur Autonomous region. Formalin-fixed, paraffin wax-embedded tumour sections were analysed for c-KIT expression using immunohistochemistry. Exons 11 and 13 of KIT were analysed for the presence of mutations using PCR amplification and DNA sequencing. RESULTS: Of the 105 MMs, 13 (10 Han and 3 Uyghur) were found to have mutations in KIT. Thus, the frequency of KIT mutations in Han patients was significantly higher than that in Uyghur patients (P = 0.02). We detected c-KIT expression in 71.4% and 42.9% of the tumour tissue samples collected from the Uyghur and Han patients, respectively. CONCLUSION: In the Xinjiang Uyghur Autonomous Region in China, chronic sun-induced damage MM is the most prevalent MM among Chinese Uyghur patients, whereas acral and mucosal MMs are the most prevalent in Uyghur patients. Mutations in the KIT gene do not correlate with c-KIT expression.

One hundred and five Kaposi sarcoma patients: a clinical study in Xinjiang, Northwest of China.

BACKGROUND: Kaposi's sarcoma (KS) is an unusual illness that may be associated with human herpes virus 8 (HHV-8) infections, and appears mainly in Jews, Italians and Greeks. There is a lack of patient data in Xinjiang regarding the clinical characteristics of KS. OBJECTIVES: To review the clinical characteristics of a series of patients with KS in Xinjiang, Northwest China, over 16-year period. METHODS: A retrospective analysis of patients referred to a Xinjiang hospital in Northwest China with classic KS (CKS) and AIDS-associated KS (AIDS-KS) between January 1997 and April 2013 was performed. Reviewed information included demographics, clinical features, histopathological traits, treatment and presence of HHV-8 infection. RESULTS: During the study period, 105 patients with a diagnosis of KS, including 77 CKS and 28 AIDS-KS, were referred to our hospital. Mean age at diagnosis was 55.8 ± 16.8 years (range: 25-85 years). There were 70 (90.9%) males and 7 (9.1%) females (male-to-female ratio: 10 : 1) having CKS and 21 (75.0%) males and 7 (25.0%) females (male-to-female ratio: 3 : 1) with AIDS-KS. Most of the patients were Uyghur, including 67 CKS and 24 AIDS-KS. The rate of multifocal lesions at diagnosis was 98.1% (103/105). The most common area of lesions was between 1% and 5% of CKS and AIDS-KS. The main types of lesions were nodules, patches and plaques. The lower extremity and foot were the most common locations for CKS and AIDS-KS. In addition to skin damage, the penis, mouth, lymph nodes and interstitial lung tissues were involved in some cases. No second primary malignancy was diagnosed. Systemic chemotherapy and radiotherapy were effective treatments for CKS. The HHV-8 positivity rate was 98.98% in 98 KS cases. CONCLUSIONS: In Xinjiang, most CKS and AIDS-KS patients were older Uyghur men. AIDS-KS was found predominantly among 30-year-old Uyghur patients, compared with 60 years for those having CKS. The latter exhibited certain characteristics such as disseminated skin disease; in some patients, the condition was accompanied by lymphedema, visceral or lymph node involvement, but no secondary malignancies. In addition, the HHV-8 positivity rate associated with KS was very high.

First Report of Pestalotiopsis microspora Causing Leaf Spot of Oil Palm (Elaeis guineensis) in China.

Oil palm (Elaeis guineensis) is a widespread, tropical evergreen species that grows in southern China. In November 2012 and July 2013, a new leaf spot was observed on oil palm in Danzhou, Hainan Province, China. A survey of 200 2-year-old oil palm plants revealed that the disease caused serious damage during the typhoon season of July to October in Hainan Province, with 15 to 20% incidence in plants. The spots were initially brown, small, and oval to irregular. Later, they gradually expanded and finally coalesced to form large gray-brown leaf spots surrounded by a dark brown border. Heavily infected leaves became dry and died. Sometimes black acervuli developed on the leaf lesions. Diseased tissues (2 × 2 mm) from lesion margins were surface-disinfested for 10 min with 0.3% NaClO, plated on potato dextrose agar (PDA), and then incubated at 25°C in the dark. Seven Pestalotiopsis isolates (identified by conidial morphological characteristics) were isolated from leaf lesions. These isolates were subcultured by single spore isolation, and a representative isolate was characterized further. The fungus was incubated on PDA at 25°C. After 5 days, the fungus produced circular white colonies. After 10 days, many black conidiomata formed over the mycelia mats. Conidia were fusiform, five-celled with constrictions at the septa, and measured 18.6 to 24.4 × 5.2 to 7.5 µm. The three median cells were light brown to dark brown, and two end cells were colorless. Apical cells had 2 to 4 appendages ranging from 10.4 to 22.6 µm long. Basal cells had 1 appendage ranging from 2.2 to 4.1 µm long. The internal transcribed spacer (ITS) region of the ribosomal DNA was amplified using primers IST4/ITS5, and the 549-bp product of the ITS (GenBank Accession No. KJ019328) showed 100% sequence identity to Pestalotiopsis microspora isolates XSD-42 (EU273522.1) and CBS364.54 (AF377292.1). The pathogenicity of all isolates was tested by inoculation of detached, healthy leaves according to Keith et al. (2). The middle parts of compound leaves with leaflets were cut from 2-year-old oil palm plant. Leaflets were wounded inoculated or unwounded inoculated with mycelial plugs (4 mm in diameter, 30 leaflets per isolate). PDA plugs without mycelia served as controls. All leaves were placed in a growth chamber at 25°C and 90% relative humidity. After 5 days, brown leaf spots appeared on all wounded leaflets, with symptoms similar to those described above. Control leaves and the inoculated leaflets without wound remained symptom free. P. microspora was re-isolated from the infected leaves and confirmed to be the same as the inoculated pathogen through examination of morphology and by conducting an ITS sequence comparison. P. neglecta and P. palmarum were previously reported as the causal agent of Pestalotiopsis leaf spot on oil palm (1). P. microspora was isolated from oil palm in Indonesia (3). To our knowledge, this is the first report of P. microspora on oil palm in China. References: (1) F. O. Aderungboya. Int. J. Pest Manage. 23:305,1977. (2) L. M. Keith et al. Plant Dis. 90:16, 2006. (3) Suwandi et al. Plant Dis. 96:537, 2012.

First Report of Rust of Plumeria rubra Caused by Coleosporium plumeriae in Guangdong Province, China.

Plumeria spp. are ornamental trees commonly planted in parks and gardens, and Plumeria rubra cultivars (Frangipani) is most common in Guangdong Province, China. A rust disease of P. rubra was observed on leaves of susceptible plants from August to December 2013. Ten nurseries were surveyed in September 2013, and 91% (220 of 240) of the plumeria plants were infected with rust. Symptoms first appeared as chlorotic spots (about 1 mm in diameter) appearing on adaxial leaf surfaces and then spread to whole leaf, and infection further resulted in leaf necrosis and abscission. Therefore, the ornamental value of diseased trees was greatly diminished. Bright yellow or yellow-orange uredinia were hypophyllous and produced under the epidermis. Urediniospores were catenulate, globose, ovoid or ellipsoid, and sometimes angular in appearance, ranging from 20.0 to 42.0 µm in length by 14.1 to 25.6 µm in width. Their walls were verrucose and 1.3 to 3.2 µm thick. No teliospores were observed. The rust was identified as Coleosporium plumeriae Pat. based on urediniospore morphology (2). Species identity was confirmed with a 1,551-bp sequence (GenBank Accession No. KF879087) of ITS rDNA amplified with rust-specific primers Rust2inv and LR6 (1). The amplicon had a 100% similarity to C. plumeriae (GU145555). Pathogenicity was confirmed by spraying a urediniospores suspension (15,000 spores ml-1) on five plants of P. rubra cultivar. Five leaves of each plant were inoculated and sealed in plastic bags, while five control plants were applied with sterile water. Plants were held at 28°C for 36 h in a dew chamber. All inoculated leaves developed typical rust symptoms with the uredinia appearing after 9 days, no symptoms developed on any control plants. Urediniospores were produced on infected leaves and pathogen identity was confirmed by morphology and re-sequencing of the ITS rDNA. Plumeria rust was first found in Hong Kong (4) and then in Hainan and Yunnan Provinces, China (3). However, this is the first report of plumeria rust in Guangdong Province, China. Frangipani has large, colorful flowers in the summer, and this rapidly spreading disease causes severe damage and affects their aesthetic value in the second half of the year. References: (1) M. C. Aime. Mycoscience 47:112, 2006. (2) N. Patouillard. Bull. Soc. Mycol. Fr. 18:171, 1902. (3) Q. Wang et al. New Dis. Rep. 23, doi:10.5197/j.2044-0588.2011.023.010, 2011. (4) J. Yan et al. Mycosystema 25:327, 2006 (in Chinese).

Genetic variants of the genes encoding zinc finger protein 313 and interleukin-13 confer a risk for psoriasis in a Chinese Uygur population.

BACKGROUND: Recent work using genome­wide association studies (GWAS) in Chinese Han and white populations have discovered several novel psoriasis susceptibility genes. AIM: To examine whether the risk loci for psoriasis identified in previous GWAS in a white population are also associated with psoriasis in a Chinese Uygur population in Xinjiang. METHODS: Genotyping analysis of eight single-nucleotide polymorphisms (SNPs) associated with psoriasis was performed for 539 patients with psoriasis and 749 controls, all of Chinese Uygur descent, using a commercial assay. RESULTS: Two SNPs had an association with psoriasis in this Chinese Uygur population: SNP rs495337 in the gene encoding for zinc finger protein 313 (P < 0.001; OR = 0.80) and SNP rs20541 of the gene encoding for interleukin-13 (P < 0.001; OR = 0.82). In subgroup analyses, the two SNPs were significantly associated (P < 0.05) with type I psoriasis, Rs495337 showed statistically difference between positive family history of psoriasis patients and controls whereas rs20541 might preferentially associated with negative family history psoriasis patients. Interestingly, using multifactor dimensionality reduction, a significant two-locus interaction was seen between rs495337 and rs20541, with a crossvalidation consistency of 4/5 and average balanced prediction (accuracy 55.5%, P < 0.001). CONCLUSIONS: ZNF313 and IL-13 are associated with risk for psoriasis in a Chinese Uygur population, and there is an effect of interaction between the two genes on this risk.

First Report of Pineapple Heart Rot Caused by Phytophthora nicotianae in Hainan Province, China.

Pineapple (Ananas comosus) is an economically important tropical fruit in Hainan Province, China. During September to November 2011, heart rot disese of pineapple was found in Ledong and Wangning of Hainan Province. A survey of 150 ha producing areas of pineapple revealed that the fields were affected at an incidence ranging from 25% to 30%. Infected plants showed water-soaked lesions and soft rot on the base of heart leaves near the soil surface. Heart leaves of infected plants were easily pulled out. As the disease progressed, plants collapsed and died. Diseased tissue fragments (2 × 2 mm) were surface-disinfected for 10 min with 0.3% NaClO, then rinsed three times in sterile water, and plated to 10% V8 juice agar (4). Inoculated dishes were incubated at 26°C in the dark. After 5 days, Phytophthora (identified by the presence of coenocytic hyphae and papillate sporangia) were isolated from the tissue cultures, which has aseptate hyphae. Sporangia were papillate, noncaducous, oval or spherical, and 34.5 to 58.2 µm. Clamydospores, both terminal and intercalary, were also spherical, and were 23.4 to 34.0 µm (2). The ITS region of rDNA was amplified using primers ITS4/ITS5, and the 927-bp product of the ITS showed 99% sequence identity to Phytophthora nicotianae (GenBank Accession No. JF792540), and the sequence was accessed to NCBI (JX978446). Pathogenicity tests were confirmed by irrigating the wounded stem bases of 10 2-month-old pineapple plants with 50 ml of P. nicotionae zoospore solution (15,000 zoospores/ml), and another 10 plants of the same cultivar inoculated with sterile water served as controls. Plants were placed in pots in a greenhouse at 28°C and 90% relative humidity. After 9 days, soft rot was observed clearly on the base of heart leaves of all 10 inoculated plants, while the control plants appeared normal. P. nicotianae was reisolated from the infected pineapple plants, and confirmed to be the same as the inoculated pathogen by conducting a ITS rDNA sequence comparison and morphological characteristics. P. nicotianae was previously reported as the causal agent of heart rot of pineapple in Hawaii, U.S.A. (3) and Guangdong Province of China (1). To our knowledge, this is the first report of P. nicotianae on pineapple in Hainan Province, China. References: (1) J. Z. Chen et al. J. Yunnan Agric. Univ. 8:134, 2003. (2) H. H. Ho. Mycologia 73:705, 1981.(3) K. W. Howard et al. Plant Dis. Rep. 48:848, 1964. (4) X. B. Zheng. Page 81 in: Phytophthora and its Research Technology. China Agricultural Press, Beijing, 1997.

First Report of Bacterial Soft Rot on Tagetes patula Caused by Dickeya dieffenbachiae in China.

French marigold (Tagetes patula L.), originally from Mexico, is an annual herb widely planted in China because of its beautiful color, long flowering, and strong adaptability, and has been used widely for ornamentation and decorating. French marigold is also rich in patuletin, quercetagetin, and patulitrin, and is therefore applied medicinally for treating colds and coughs. In early summer 2012, soft rot symptoms on French marigold were found at three flower nurseries in Guangzhou, Guangdong Province, P. R. China, and approximately 25% of the plants had the symptoms. The symptoms included tissue collapse of the stems at the soil line followed by wilting of the whole plants. Within 1 week, the infected stems showed vascular discoloration, turned brown and then inky black, and eventually the whole plant collapsed after the basal stem was infected. Bacteria were successfully isolated from eight symptomatic plants on nutrient agar media incubated at 30°C for 48 h. Ten isolates were selected randomly for further characterization. They were gram negative, degraded pectate, negative for oxidase and positive for indole production, and utilized malonate, glucose, and sucrose but not glucopyranoside, trehalose, or palatinose. Polymerase chain reactions (PCR) were performed using the 16S primers 27f and 1495r (4) for molecular identification. Subsequent DNA sequencing showed that the representative tested strain TP1 (GenBank Accession No. JX575747) was 99% identical to that of Dickeya dieffenbachiae (JF419463) using BLASTn. Further genetic analysis of strain TP1 was performed targeting several housekeeping genes, i.e., dnaX (GenBank Accession No. JX575748) with primers dnaxf and dnaxr (3), gyrB (JX575749) with primers of gyrbf1 and gyrbr1 (1), and gapA (JX575750) with primers of gapa326f and gapa845r (2). They were most homologous to the sequences of D. dieffenbachiae, since they had 97%, 96%, and 97% identity with GenBank accessions GQ904794, JF311653, and GQ891968, respectively. Pathogenicity was confirmed by injecting all 10 original bacterial isolates into each of 10 French marigold seedlings, with approximately 100 µl of a bacterial suspension at 1 × 108 CFU/ml. Ten plants inoculated with 100 µl of sterile water served as controls. Plants were placed in a greenhouse at 30 to 32°C and 90% relative humidity. Within 48 h, soft rot symptoms appeared on all inoculated seedlings, while the control plants appeared normal. D. dieffenbachiae was reisolated from the diseased tissues, and confirmed to be the same as the inoculated pathogen by conducting a 16S rDNA sequence comparison. Previously, black spot, botrytis blight, oedema, powdery mildew, southern bacterial wilt, and damping off have been found on T. patula. To our knowledge, it is the first report of a soft rot caused by D. dieffenbachiae on French marigold. Because of the popularity and high economic value of French marigold, identification of this progressing bacterial disease is important to maintain safe production and beautiful scenery. References: (1) B. R. Lin et al. Plant Dis. 96:452, 2012. (2) S. Nabhan et al. Plant Pathol. 61:498, 2012. (3) M. Slawiak et al. Eur. J. Plant Pathol. 125:245, 2009. (4) W. G. Weisburg. J. Bacteriol. 173:697, 1991.

First Report of a Soft Rot of Philodendron 'Con-go' in China Caused by Dickeya dieffenbachiae.

Philodendron is a popular foliage plant cultivated in interiorscapes of homes, offices, and malls throughout China. A severe outbreak of a soft rot of Philodendron 'Con-go' occurred in Guangzhou, China from 2010 to 2011. The disease was characterized by leaf infections starting as pinpoint spots that are water soaked and yellow to pale brown. The lesions are sometimes surrounded by a diffuse yellow halo. When the humidity is high and temperatures are warm to hot, the spots expand rapidly, becoming slimy, irregular, and sunken with light tan centers, darker brown borders, and diffused yellow margins and may involve the entire leaf in a few days. An invasion of the midrib and larger veins by the causal bacterium often results in advancement into the petiole and stem. A survey of three areas of production of Philodendron 'Con-go' (5 ha) in Guangzhou revealed that 91% of the fields were affected at an incidence ranging from 15 to 30%. Of 41 bacterial isolates obtained from lesions, three were selected randomly for further characterization. All strains were gram negative, negative for oxidase and positive for catalase and tryptophanase (indole production), and utilized citrate, tartrate, malonate, glucose, sucrose, fructose, and maltose but not glucopyranoside, trehalose, or palatinose. Biolog analysis (version 4.20.05, Hayward, CA) identified the isolates as Pectobacterium chrysanthemi (SIM 0.804 to 0.914). According to Samson et al. (1), it was renamed as a Dickeya sp. PCR was performed on the 16S rDNA gene with primers 27f and 1495r (3) and 1,423 bp of the 16S rDNA gene (GenBank No. JN709491) showed 99% identity to P. chrysanthemi (GenBank No. AF373202), and 98% to Dickeya dieffenbachiae (GenBank No. JF311644). Additionally, the gyrB gene was amplified with primers gyrB-f1 (5'-atgtcgaattcttatgactcctc-3') and gyrB-r1 (5'-tcaratatcratattcgcygctttc-3') designed based on all the submitted gyrB gene sequences of Dickeya spp. The dnaX gene was amplified with primers dnaXf and dnaXr (2). The products were sequenced and phylogeny analyses were performed by means of MEGA 5.05. Results showed that the gyrB and the dnaX genes of the strains were 98% homologous to those of D. dieffenbachiae (GenBank Nos. JF311652 and GQ904757). Therefore, on the basis of phylogenetic trees of the 16S rDNA, gyrB, and dnaX gene sequences, the bacterial isolate named PC1 is related to D. dieffenbachiae (100% bootstrap values). Pathogenicity of each of the three strains on Philodendron 'Con-go' was confirmed by injecting 60 50-day-old seedlings each with 0.1 ml of the isolate suspension (108 CFU/ml) into the leaves. Another 60 were injected with sterile water to serve as the control treatment. Plants were enclosed in plastic bags and returned to the greenhouse under 50% shade at 32°C day and 28°C night temperatures with high humidity. After 72 h, all the injected plants started to show symptoms similar to those observed on field plants, but no symptoms appeared on the control plants. The reisolates were identical to the inoculated strains in biochemical characteristics. Bacteria characteristic of the inoculated strains were not reisolated from the control plants. To our knowledge, this is the first report of D. dieffenbachiae causing soft rot of Philodendron 'Con-go' in China. References: (1) R. Samson et al. Evol. Microbiol. 55:1415, 2005. (2) M. Slawiak et al. Eur. J. Plant Pathol. 125:245, 2009. (3) W. G. Weisbury et al. J. Bacteriol. 173:697, 1991.

First Report of Bacterial Foot Rot of Rice Caused by a Dickeya zeae in China.

A bacterial disease of rice, bacterial foot rot, was found in Guangdong Province, China in September 2011, with an incidence about 10%. The typical symptom was a dark brown decay of the tillers. In the early stages of the disease, a brown sheath rot seemed to spread from the ligulae regions. The lesions quickly extended down to the nodes, culms, and finally to the crowns. Neighboring tillers of the same crown were invaded systemically, causing foot rot symptoms. A soft rot with an unpleasant odor developed in young tissues of infected tillers. In the advanced stage, many tillers decayed, so that entire diseased plants could easily be pulled from the soil. Six diseased samples were collected and bacteria were isolated from the edge of symptomatic tissues, after samples were sterilized in 0.3% NaOCl for 10 min, rinsed in sterile water three times, and placed on nutrient agar (beef extract 3 g, yeast extract 1 g, peptone 5 g, glucose 10 g, agar 16 g, distilled water 1 L, pH 6.8 to 7.0). For identification, a total of 12 representative isolates were selected. All strains were Gram negative, grew at 37°C, were positive for indole production, and utilized malonate, glucose, and sucrose, but not glucopyranoside, trehalose, or palatinose. Biolog identification (Version 4.20.05, Hayward, CA) identified isolate EC1 as Pectobacterium chrysanthemi (SIM 0.827), which has since been transferred to genus Dickeya. PCR was used to amplify the 16S rDNA gene with primers 27f and 1492r, the dnaX gene with primers dnaXf and dnaXr (2), and the gyrB gene with primers gyrBf1 (5'-ATGTCGAATTCTTATGACTCCTC-3') and gyrB-r1 (5'-TCARATATCRATATTCGCYGCTTTC-3'), which were designed based on published gyrB gene sequences of genus Dickeya. A BLASTn search of all three loci [16S rDNA (JQ284040), dnaX (JQ284041), and gyrB (JQ284042)] revealed that EC1 had 100% sequence identify to Dickeya zeae [16S rDNA (AB713560), dnaX (AB713593), gyrB (AB713635)]. Pathogenicity tests were conducted by injecting 10 rice seedlings with 100 µl of the bacterial suspension (1 × 108 CFU/ml) in the stem base, and an additional 10 rice seedlings were injected with 100 µl of sterile water as negative controls. Inoculations were carried out in a greenhouse at 28 to 32°C and 90% relative humidity. Foot rot symptoms identical to those described above were observed after 7 days on inoculated plants, but not on the negative controls. The bacterium was reisolated from the lesions and had 100% sequence identity for all three loci to EC1. Previously, similar symptoms were reported on rice in Guangdong province of China, and the causal agent was identified as Erwinia chrysanthemi (1). To our knowledge, this is the first report of D. zeae causing foot rot disease on rice in China. References: (1) Q. G. Liu et al. J. South China Agric. Univ. 18:128, 1997. (2) M. Slawiak et al. Eur. J. Plant Pathol. 125:245, 2009.

First Report of Bacterial Soft Rot of Potato Caused by Pectobacterium carotovorum subsp. carotovorum in Guangdong Province of China.

Potato (Solanum tuberosum L.) is a major crop in China, with 80.0 million tons being produced in 2010 on 3.3 million ha. Pectobacterium carotovorum subsp. carotovorum Jones 1901; Hauben et al. 1999 causes soft rot worldwide on a wide range of hosts including potato, carrot, and cabbage. During spring 2010, a soft rot with a foul smell was noted in stored potato tubers of different cultivars in the Guangdong Province. Symptoms on tubers appeared as tan, water-soaked areas with watery ooze. The rotted tissues were white to cream colored. Stems of infected plants with typical inky black symptoms could also be found in the fields prior to harvest. Three different potato fields were surveyed, and 13% of the plants had the symptoms. Twenty-seven samples (three symptomatic tubers per sample) were collected. Bacteria were successfully isolated from all diseased tissues on nutrient agar media supplemented with 5% sucrose and incubated at 26 ± 1°C for 36 h. After purification on tripticase soy agar media, four typical strains (7-3-1, 7-3-2, 8-3-1, and 8-3-2) were identified using the following deterministic tests: gram-negative rods, oxidase negative, facultatively anaerobic, able to degrade pectate, sensitive to erythromycin, negative for phosphatase, unable to produce acid from α-methyl-glucoside, and produced acid from trehalose. Biolog analysis (Ver 4.20.05, Hayward, CA) identified the strains as P. carotovorum subsp. carotovorum (SIM 0.808, 0.774, 0.782, and 0.786, respectively). The identity of strains 7-3-1 (GenBank Accession No. JX258132), 7-3-2 (JX258133), and 8-3-1 (JX196705) was confirmed by 16S rRNA gene sequencing (4), since they had 99% sequence identity with other P. carotovorum subsp. carotovorum strains (GenBank Accession Nos. JF926744 and JF926758) using BLASTn. Further genetic analysis of strain 8-3-1 was performed targeting informative housekeeping genes, i.e., acnA (GenBank Accession No. JX196704), gabA (JX196706), icdA (JX196707), mdh (JX196708), mtlD (JX196709), pgi (JX196710), and proA (JX196711) (2). These sequences from strain 8-3-1 were 99 to 100%, homologous to sequences of multiple strains of P. carotovorum subsp. carotovorum. Therefore, strain 8-3-1 grouped with P. carotovorum subsp. carotovorum on the phylogenetic trees (neighbor-joining method, 1,000 bootstrap values) of seven concatenated housekeeping genes when compared with 60 other strains, including Pectobacterium spp. and Dickeya spp. (3). Pathogenicity of four strains (7-3-1, 7-3-2, 8-3-1, and 8-3-2) was evaluated by depositing a bacterial suspension (106 CFU/ml) on the potato slices of cultivar 'Favorita' and incubating at 30 ± 1°C. Slices inoculated with just water served as non-inoculated checks. The strains caused soft rot within 72 h and the checks had no rot. Bacteria were reisolated from the slices and were shown to be identical to the original strains based on morphological, cultural, and biochemical tests. Although this pathogen has already been reported in northern China (1), to our knowledge, this is the first report of P. carotovorum subsp. carotovorum causing bacterial soft rot of potato in Guangdong Province of China. References: (1) Y. X. Fei et al. J. Hexi Univ. 26:51, 2010.(2) B. Ma et al. Phytobacteriology 97:1150, 2007. (3) S. Nabhan et al. Plant Pathol. 61:498, 2012. (4) W. G. Weisbury et al. J. Bacteriol. 173:697, 1991.

First Report of a Soft Rot of Phalaenopsis aphrodita Caused by Dickeya dieffenbachiae in China.

Phalaenopsis orchids, originally from tropical Asia, are mainly planted in Thailand, Singapore, Malaysia, the Philippines, and Taiwan and have gained popularity from consumers all over the world. The cultivation area of Phalaenopsis orchids has been rising and large-scale bases have been established in mainland China, especially South China because of suitable environmental conditions. In September 2011, a soft rot of Phalaenopsis aphrodita was found in a Phalaenopsis planting base in Guangzhou with an incidence of ~15%. Infected plants initially showed water-soaked, pale-to-dark brown pinpoint spots on leaves that were sometimes surrounded by a yellow halo. Spots expanded rapidly with rising humidity and temperatures, and in a few days, severely extended over the blade with a light tan color and darker brown border. Lesions decayed with odorous fumes and tissues collapsed with inclusions exuding. The bacterium advanced to the stem and pedicle. Finally, leaves became papery dry and the pedicles lodged. Six diseased samples were collected, and bacteria were isolated from the edge of symptomatic tissues after sterilization in 0.3% NaOCl for 10 min, rinsing in sterile water three times, and placing on nutrient agar for culture. Twelve representative isolates were selected for further characterization. All strains were gram negative, grew at 37°C, were positive for indole production, and utilized malonate, glucose, and sucrose but not glucopyranoside, trehalose, or palatinose. Biolog identification (version 4.20.05, Hayward, CA) was performed and Pectobacterium chrysanthemi (SIM 0.868) was confirmed for the tested isolates (transfer to genus Dickeya). PCR was used to amplify the 16S rDNAgene with primers 27f and 1492r, dnaX gene with primers dnaXf and dnaXr (3), and gyrB gene with primers gyrBf (5'-GAAGGYAAAVTKCATCGTCAGG-3') and gyrB-r1 (5'-TCARATATCRATATTCGCYGCTTTC-3') designed on the basis of the published gyrB gene sequences of genus Dickeya. BLASTn was performed online, and phylogeny trees (100% bootstrap values) were created by means of MEGA 5.05 for these gene sequences, respectively. Results commonly showed that the representative tested strain, PA1, was most homologous to Dickeya dieffenbachiae with 98% identity for 16S rDNA(JN940859), 97% for dnaX (JN989971), and 96% for gyrB (JN971031). Thus, we recommend calling this isolate D. dieffenbachiae PA1. Pathogenicity tests were conducted by injecting 10 P. aphrodita seedlings with 100 µl of the bacterial suspension (1 × 108 CFU/ml) and another 10 were injected with 100 µl of sterile water as controls. Plants were inoculated in a greenhouse at 28 to 32°C and 90% relative humidity. Soft rot symptoms were observed after 2 days on the inoculated plants, but not on the control ones. The bacterium was isolated from the lesions and demonstrated identity to the inoculated plant by the 16S rDNA sequence comparison. Previously, similar diseases of P. amabilis were reported in Tangshan, Jiangsu, Zhejiang, and Wuhan and causal agents were identified as Erwinia spp. (2), Pseudomonas grimontii (1), E. chrysanthemi, and E. carotovora subsp. carovora (4). To our knowledge, this is the first report of D. dieffenbachiae causing soft rot disease on P. aphrodita in China. References: (1) X. L. Chu and B. Yang. Acta Phytopathol. Sin. 40:90, 2010. (2) Y. M. Li et al. J. Beijing Agric. Coll. 19:41, 2004. (3) M. Slawiak et al. Eur. J. Plant Pathol. 125:245, 2009. (4) Z. Y. Wu et al. J. Zhejiang For. Coll. 27:635, 2010.

First Report of a Soft Rot of Banana in Mainland China Caused by a Dickeya sp. (Pectobacterium chrysanthemi).

Banana is one of the most important fruit crops grown in China (2). A severe outbreak of a soft rot of banana occurred in Guangzhou, China from 2009 to 2010. The disease was characterized by an odorous soft rot of the center of the rhizome. The rot progressed up the pseudostem, destroying the growing point and causing internal decay and often accompanied by vascular discoloration. Yellowing and wilting of the leaves were also characteristic symptoms. A survey of three areas of production of Musa sapientum (cv. ABB) covering 10 ha in Guangzhou revealed that 82% of the fields were affected at an incidence ranging from 20 to 40%. Forty-five bacterial isolates were obtained from lesions on plants sampled from these fields by surface-sterilizing symptomatic tissue in 0.3% NaOCl for 10 min, rinsing the tissue sections three times in sterile water, and plating the sections on nutrient agar. Three representative isolates selected randomly were all gram negative, caused a soft rot of potato disks, utilized malonate, tested positive for phosphatase production, and tested negative for acid production from palatinose, glucopyranoside, and trehalose. A Biolog similarity index of 0.803 indicated that the three isolates had a high similarity to the Biolog reference strain of Pectobacterium chrysanthemi (Version 4.2, Biolog Inc., Hayward, CA). The 16S rDNA sequence (GenBank Accession No. 1321085) of each of the three isolates was determined (1). When compared with sequences in GenBank, the highest degree of sequence similarity was with P. chrysanthemi AF373199. On the basis of a phylogenetic tree of the sequences, the three bacterial isolates are related to Pectobacterium (100% bootstrap values). On the basis of two diagnostic methods, the three isolates were identified as P. chrysanthemi. However, according to Samson et al. (3), they are a Dickeya sp. Additional genetic comparisons with type strains will be needed for the strains to be assigned to a known species of Dickeya. Pathogenicity of each of the three strains on M. sapientum (cv. ABB) was confirmed by injecting 60 40-day-old seedlings each with 5 ml of a suspension of the isolate (108 CFU/ml) into the rhizome. Sixty plants of the same cultivar injected with sterile water served as the control treatment. After 48 h, yellowing and wilting of the leaves, similar to symptoms observed on field plants, were observed on all inoculated seedlings for each of the three bacterial strains. There were no symptoms on the control plants. Koch's postulates were fulfilled by reisolating bacteria from lesions on the leaves of inoculated seedlings. The reisolates were identical to the inoculated strains in biochemical characteristics. Bacteria characteristic of the inoculated strains were not reisolated from the control plants. To our knowledge, this is the first report of a Dickeya sp. causing soft rot of banana in mainland China. References: (1) W. S. Kaneshiro et al. Plant Dis. 92:1444, 2008. (2) Y. P. Ke et al. China Trop. Agric. 1:14, 2008. (3) R. Samson et al. Evol. Microbiol. 55:1415, 2005.