ICTV Virus Taxonomy Profile: Fimoviridae 2024.

Members of the family Fimoviridae are plant viruses with a multipartite negative-sense enveloped RNA genome (-ssRNA), composed of 4-10 segments comprising 12.3-18.5 kb in total, within quasi-spherical virions. Fimoviruses are transmitted to plants by eriophyid mites and induce characteristic cytopathologies in their host plants, including double membrane-bound bodies in the cytoplasm of virus-infected cells. Most fimoviruses infect dicotyledonous plants, and many cause serious disease epidemics. This is a summary of the ICTV Report on the family Fimoviridae, which is available at ictv.global/report/fimoviridae.

Similar short-term KOOS between open-wedge high tibial osteotomy and total knee arthroplasty in patients over age 60: A propensity score-matched cohort study.

OBJECTIVES: The purpose of the present study was to evaluate improvement in the Knee Injury and Osteoarthritis Outcome Score (KOOS) after open-wedge high tibial osteotomy (HTO) in comparison with total knee arthroplasty (TKA) in cohorts over age 60 matched by pre-operative age, gender, body mass index (BMI), hip-knee-ankle angle (HKAA), KOOS sub-scores, and osteoarthritis (OA) grade. METHODS: Propensity score matching was performed between 162 HTO patients and 134 TKA patients. When calculating the propensity score by multivariate logistic regression analysis, the following pre-operative confounders were included: age, gender, BMI, HKAA, KOOS sub-scores, and OA grade. Consequently, a total of 55 patients were included in each group. The Student's t-test was used to analyse differences in the post-operative KOOS sub-scores between groups. RESULTS: After propensity score matching, all matched pre-operative valuables were identical, with no significant differences between the HTO and TKA groups. None of the post-operative KOOS sub-scores at 1 year after surgery showed a significant difference between the HTO and TKA groups. Both groups demonstrated significant and comparable post-operative improvement in every KOOS sub-score. CONCLUSIONS: In patients over age 60, there was no significant difference in short-term pain relief and improvements in activity and quality of life between HTO and TKA after propensity score matching including pre-operative age, KOOS sub-scores, and OA grade. HTO is a joint preservation procedure that is valid for knee OA even in individuals over age 60.

Complete nucleotide sequence of chrysanthemum mosaic-associated virus, a novel emaravirus infecting chrysanthemum.

Here, we report the complete genome sequence of chrysanthemum mosaic-associated virus (ChMaV), a putative new member of the genus Emaravirus. The ChMaV genome comprises seven negative-sense RNA segments (RNAs 1, 2, 3a, 3b, 4, 5, and 6), and the amino acid sequences of its RNA-dependent RNA polymerase (RNA1), glycoprotein precursor (RNA2), nucleocapsid protein (RNA3), and movement protein (RNA4) showed the closest relationship to pear chlorotic leaf spot-associated virus. Phylogenetic analysis showed that it clusters with emaraviruses whose host plants originate from East Asia.

Perilla Mosaic Virus Is a Highly Divergent Emaravirus Transmitted by Shevtchenkella sp. (Acari: Eriophyidae).

Shiso (Perilla frutescens var. crispa) is widely grown as an important vegetable or herb crop in Japan. Beginning around the year 2000, occurrences of severe mosaic symptoms on shiso were documented and gradually spread across Kochi Prefecture, one of four major shiso production areas in Japan. Next generation sequencing and cloning indicated the presence of a previously unknown virus related to the members of the genus Emaravirus, for which we proposed the name Perilla mosaic virus (PerMV). The genome of PerMV consists of 10 RNA segments, each encoding a single protein in the negative-sense orientation. Of these proteins, P1, P2, P3a, P3b, P4, and P5 show amino acid sequence similarities with those of known emaraviruses, whereas no similarities were found in P6a, P6b, P6c, and P7. Characteristics of the RNA segments as well as phylogenetic analysis of P1 to P4 indicate that PerMV is a distinct and highly divergent emaravirus. Electron microscopy observations and protein analyses corresponded to presence of an emaravirus. Transmission experiments demonstrated that an eriophyid mite, Shevtchenkella sp. (family Eriophyidae), transmits PerMV with a minimum 30-min acquisition access period. Only plants belonging to the genus Perilla tested positive for PerMV, and the plant-virus-vector interactions were evaluated. The nucleotide sequences reported here are available in the DDBJ/ENA/GenBank databases under accession numbers LC496090 to LC496099.

First report of pear chlorotic leaf spot-associated virus on Japanese and European pears in Japan and its detection from an eriophyid mite.

In May 2018, three leaf samples were collected from Japanese pear trees cv. "Hosui" that exhibited typical chlorotic spot symptoms (Supplementary Figure S1) in a germplasm nursery in Tsukuba, Ibaraki. Total RNA was prepared using the rapid CTAB method (Gambino et al. 2008) for high-throughput sequencing, as described by Kubota et al. (2020). In brief, after removing ribosomal RNAs, a library was constructed by fragmenting RNA, synthesizing cDNA, and polymerase chain reaction (PCR) amplification. Sequencing was performed using NovaSeq 6000 sequencer (Illumina, San Diego, CA, U.S.A.) with paired-end 150 nt reads. De novo assembly was performed using CLC Genomics Workbench 11.0 Software (Qiagen, Hilden, Germany), with a minimum length of 500 bp. A total of 36,017 contigs derived from 33,565,182 reads were obtained and subjected to BLASTX search against the GenBank sequence database as of January 2019. Viruses commonly found in stone fruits, i.e., apple stem pitting virus, apple green crinkle-associated virus, apricot latent virus (foveaviruses), and apple stem grooving virus (a capillovirus), were detected. In addition, five contigs with amino acid sequence homologies to P1-P4 of known emaraviruses and the P7 of High Plains wheat mosaic virus (Tatineni et al. 2014) were detected and designated as PEV-Jp. The complete nucleotide (nt) sequences of the five segments of PEV-Jp were determined by Sanger sequencing of cloned reverse transcription (RT)-PCR amplification products using the primers shown in Supplementary Table S1; the 5'- and 3'-terminal sequences were RACE verified (Takara Bio, Shiga, Japan). In pairwise comparisons, the complete RNA1 to RNA5 of PEV-Jp (LC554756-760) shared 90.7% to 98.7% nt identities with those of PCLSaV-CG1 (MK602177-181), indicating that PEV-Jp is an isolate of PCLSaV. Using newly designed segment-specific primers (Supplementary Table S1), 12 symptomatic Japanese pear trees cv. "Kosui" sampled in 2020 from the same nursery tested positive for PCLSaV by RT-PCR while 12 symptomless trees were negative for the virus. Similar chlorotic spots, sometimes accompany necrotic spots, were observed on European pear (Pyrus communis) cv. "Le Lectier." (Fig. S1F) in Niigata in 2019; PCLSaV was detected by RT-PCR in leaf tissue samples from symptomatic trees (n = 3/3) but not in symptomless trees (n = 0/2). No vector for PCLSaV has been identified (Liu et al. 2020) but acaricide sprays in the early spring are effective for preventing occurrence of chlorotic spots in pear orchards (Nakai et al. 2018). Since the infestations of Eriophyes chibaensis Kadono, an eriophyid mite often observed on the Japanese pear (Fig. S1G to S1I) (Kadono, 1981), has been associated with occurrences of the chlorotic spots (Shimizu et al. 2019), samples of E. chibaensis individuals were collected from PCLSaV-positive Japanese pear cvs. "Akizuki" and "Kosui"and P. communis cv. "Le Lectier." for total nucleic acid isolations via phenol-chloroform extraction, followed by quantitative RT-PCR (Supplementary Table S1). The expected RNA1 and RNA5 specific 150 bp products were detected from mite samples collected from Akizuki (n = 6/12), Kosui (n = 13/18), and Le Lectier (n = 6/8). The results indicate that E. chibaensis can ingest PCLSaV and may be a potential vector for the virus, although additional experiments are needed to demonstrate its vector competency. To our knowledge, this is the first report of PCLSaV in Japan and the first report of its detection in E. chibaensis.

Distal tuberosity osteotomy in open-wedge high tibial osteotomy does not exacerbate patellofemoral osteoarthritis on arthroscopic evaluation.

PURPOSE: The purpose of the present study was to use arthroscopy to evaluate the effect of distal tuberosity osteotomy (DTO) in open-wedge high tibial osteotomy (OW-HTO) on patellofemoral (PF) cartilage degradation. METHODS: Between 2012 and 2017, 46 knees underwent DTO in OW-HTO, and 65 knees underwent conventional OW-HTO (cOW-HTO). To assess changes in patellar height, the Blackburne-Peel (BP) ratio and the Caton-Deschamps (CD) index were measured. Arthroscopic evaluation on the PF joint was performed at the initial osteotomy and at the second-look procedure 1 year later. Statistical analyses were performed to compare difference between the DTO and the cOW-HTO group. RESULTS: In the cOW-HTO group, the mean BP ratio and CD index decreased significantly from 0.81 and 0.89 preoperatively, respectively, to 0.69 and 0.76 postoperatively, respectively (p < 0.001). In contrast, the DTO group maintained a consistent patellar height; the mean BP ratio and CD index were 0.77 and 0.83 preoperatively, respectively, and 0.73 and 0.80 postoperatively, respectively. Upon arthroscopic evaluation, 39 of 46 patients (84.8%) in the DTO group showed no progression of PF cartilage degradation at the second look; indeed, five of 46 patients (10.9%) even demonstrated improvement. In contrast, 21 of 65 patients (32.3%) in the cOW-HTO group exhibited increased PF cartilage degradation. There was a significant difference in progression of PF cartilage degradation between DTO and cOW-HTO (p < 0.001). CONCLUSION: DTO in OW-HTO maintained the preoperative patellar height, which could help prevent progression of cartilage degeneration in the PF joint after surgery. In respect of the biplanar osteotomy direction in OW-HTO, the DTO, rather than cOWHTO, is the preferred technique for the treatment of varus knee osteoarthritis to avoid progression of PF cartilage degradation. LEVEL OF EVIDENCE: III.

Gastric mucosal status susceptible to lanthanum deposition in patients treated with dialysis and lanthanum carbonate.

Lanthanum carbonate is a popular chemical which is administered for patients with end-stage kidney disease to reduce the absorption of phosphate, and lanthanum deposition in the gastroduodenal mucosa has recently been reported. The aim of this study was to assess whether any histologic changes of the gastric mucosa are related to the deposition of lanthanum. Twenty-four patients who revealed the histology of lanthanum deposition on gastroduodenal biopsy between 2011 and 2014 were included in the study, and their clinical records and gastroduodenal biopsies obtained from 2011 to 2015 were reviewed, adding the review of gastroduodenal biopsies before 2011 if possible. Analysis of the deposited materials by scanning electron microscopy-energy dispersive x-ray spectroscopy was performed for a representative gastric biopsy. All patients were diagnosed as having renal insufficiency due to chronic kidney disease and treated with dialysis for more than 5 years, with confirmation of lanthanum carbonate use for 22 patients. Of 121 gastric biopsies and 10 duodenal ones between 2011 and 2015, 86 gastric biopsies (71.1%) and 3 duodenal biopsies (30%), respectively, revealed histology consistent with lanthanum deposition, which was confirmed by scanning electron microscopy-energy dispersive x-ray spectroscopy analysis for a representative case. The deposition tended to occur in the gastric mucosa with regenerative change, intestinal metaplasia, or foveolar hyperplasia (P<.05). Such mucosal changes were observed in about half of the gastric biopsy samples obtained prior to 2010, in which no lanthanum deposition was identified irrespective of the gastric mucosal status. Although direct association between lanthanum deposition and clinical symptoms is not clear, the evaluation of the gastric mucosal status (prior to administration) seems to be important to predict lanthanum deposition when lanthanum carbonate is administered for patients with chronic kidney disease treated with dialysis.

[Emergence of emaraviruses, the eriophyoid mite-transmitted viruses in plants].

Members of the genus Emaravirus are plant viruses transmitted by eriophyoid mites. The emaravirus genome consists of multiple, negative-sense, single-stranded RNA segments, that have been shown to be highly divergent. Recent studies have revealed that emaraviruses are associated with long-recognized diseases of world important crops such as fig mosaic disease or sterility mosaic disease of pigeon pea. Furthermore, along with the popularization of deep sequencing technologies, new putative members of emaraviruses have been reported year by year. This paper presents an overview of agricultural damages caused by emaraviruses worldwide and characteristics of their genomic RNAs and proteins. In addition, our research project to prevent a disease of a herb crop (shiso, Perilla frutescens) caused by Perilla mosaic virus, a putative emaravirus recently identified in Japan, is outlined.

Lettuce chlorosis virus P23 Suppresses RNA Silencing and Induces Local Necrosis with Increased Severity at Raised Temperatures.

RNA silencing functions as an antivirus defense strategy in plants, one that plant viruses counter by producing viral suppressors of RNA silencing (VSRs). VSRs have been identified in three members of the genus Crinivirus but they do not all share identical suppression mechanisms. Here, we used Agrobacterium co-infiltration assays to investigate the suppressor activity of proteins encoded by Lettuce chlorosis virus (LCV). Of 7 LCV proteins (1b, P23, HSP70 homolog, P60, CP, CPm, and P27) tested for the suppression of silencing of green fluorescent protein (GFP) expression in wild-type Nicotiana benthamiana plants, only P23 suppressed the onset of local silencing. Small-interfering (si)RNA accumulation was reduced in leaves co-infiltrated with P23, suggesting that P23 inhibited the accumulation or enhanced the degradation of siRNA. P23 also inhibited the cell-to-cell and systemic movement of RNA silencing in GFP-expressing transgenic N. benthamiana plants. Expression of P23 via agroinfiltration of N. benthamiana leaves induced local necrosis that increased in severity at elevated temperatures, a novelty given that a direct temperature effect on necrosis severity has not been reported for the other crinivirus VSRs. These results further affirm the sophistication of crinivirus VSRs in mediating the evasion of host's antiviral defenses and in symptom modulation.

Identification of residues required for stalled-ribosome rescue in the codon-independent release factor YaeJ.

The YaeJ protein is a codon-independent release factor with peptidyl-tRNA hydrolysis (PTH) activity, and functions as a stalled-ribosome rescue factor in Escherichia coli. To identify residues required for YaeJ function, we performed mutational analysis for in vitro PTH activity towards rescue of ribosomes stalled on a non-stop mRNA, and for ribosome-binding efficiency. We focused on residues conserved among bacterial YaeJ proteins. Additionally, we determined the solution structure of the GGQ domain of YaeJ from E. coli using nuclear magnetic resonance spectroscopy. YaeJ and a human homolog, ICT1, had similar levels of PTH activity, despite various differences in sequence and structure. While no YaeJ-specific residues important for PTH activity occur in the structured GGQ domain, Arg118, Leu119, Lys122, Lys129 and Arg132 in the following C-terminal extension were required for PTH activity. All of these residues are completely conserved among bacteria. The equivalent residues were also found in the C-terminal extension of ICT1, allowing an appropriate sequence alignment between YaeJ and ICT1 proteins from various species. Single amino acid substitutions for each of these residues significantly decreased ribosome-binding efficiency. These biochemical findings provide clues to understanding how YaeJ enters the A-site of stalled ribosomes.

Intrauterine sensitization of allergen-specific IgE analyzed by a highly sensitive new allergen microarray.

BACKGROUND: To design a rational allergy prevention program, it is important to determine whether allergic sensitization starts in utero under the maternal immune system. OBJECTIVE: To investigate the origin of allergen-specific IgE antibodies in cord blood (CB) and maternofetal transfer of immunoglobulins. METHODS: The levels of food and inhalant allergen-specific IgE, IgA, IgG, and IgG(4) antibodies in CB and maternal blood (MB) from 92 paired neonates and mothers were measured by using a novel allergen microarray of diamond-like-carbon-coated chip, with high-sensitivity detection of allergen-specific antibodies and allergen profiles. RESULTS: The levels of allergen-specific IgE antibodies against food and inhalant allergens and allergen profiles were identical in CB and newborn blood, but the levels and profiles, specifically against inhalant allergens, were different from those in MB. The level of allergen-specific IgA antibodies was below the detection levels in CB despite clear detection in MB. Therefore, contamination with MB in CB was excluded on the basis of extremely low levels of IgA antibodies in CB and the obvious mismatch of the allergen-specific IgE and IgA profiles between CB and MB. However, the levels of allergen-specific IgG and IgG(4) antibodies and their allergen profiles were almost identical in both MB and CB. CONCLUSION: Allergen-specific levels of IgE and IgA antibodies and their allergen profiles analyzed by the diamond-like-carbon allergen chip indicate that IgE antibodies in CB are of fetal origin. Food-allergen specific IgE antibodies were detected more often than inhalant-allergen specific IgE antibodies in CB, the reason of which remains unclarified.

Updates on cadaver surgical training in Japan: a systematic facility at Chiba University.

Cadaver surgical training (CST), which ensures medical safety by improving the skills of surgeons, is popular overseas. However, training involves ethical issues given the use of cadavers. In 2012, the Japan Surgical Society and the Japanese Association of Anatomists compiled and opened the "Guidelines for Cadaver Dissection in Education and Research of Clinical Medicine (Guideline 2012)" to the public. This has allowed Japan to conduct CST or research under the regulations of Postmortem Examination and Corpse Preservation Act and the Body Donation Act. However, its dissemination has been sluggish. The Clinical Anatomy Lab (CAL), established in 2010 at Chiba University, is a facility for conducting CST and research. In the 11 years since its inception, 250 programs have been implemented. Orthopedics had the most implemented in the clinical field, with 120 (48%), followed by emergency and critical care medicine with 27 (10.8%), and neurological surgery with 27 (10. 8%). Based on the purpose of the training, the most common objective for the programs (approximately 83%) was education. Further, the highest number of programs was recorded in 2018 (34) and participants in 2017 (631). The implementation of CST requires more than just guiding surgeons to a dissection practice room. There are several methods of preserving cadavers to make them suitable for CST. For various surgical simulations, an operating table is more suitable than a dissection table. The current paper provides information on how to implement CST in universities that have so far only worked on anatomy education for medical students.

Massive hemoptysis treated with embolization of an ectopic bronchial artery arising from the right thyrocervical trunk: a case report.

BACKGROUND: Ectopic bronchial artery and non-bronchial systemic arteries may be the culprit vessels of hemoptysis. The main cause of clinical failure of bronchial artery embolization is incomplete embolization caused by the misidentification of the culprit arteries by conventional angiography. Multidetector computed tomography angiography is useful for visualizing the culprit arteries. CASE PRESENTATION: An 82-year-old man was admitted with hemoptysis. Preprocedural multidetector computed tomography angiography revealed an ectopic bronchial artery branching from the right thyrocervical trunk. Superselective embolization of the ectopic bronchial artery was performed using gelatin sponge particles and metallic coils. Hemoptysis was controlled by this procedure without any associated complications. CONCLUSIONS: Ectopic bronchial arteries originating from the thyrocervical trunk are rare. Preprocedural multidetector computed tomography angiography is useful for visualizing the culprit arteries of hemoptysis, especially if a patient has an ectopic bronchial artery or an ectopic non-bronchial systemic artery.

Novel degenerate primer sets for the detection and identification of emaraviruses reveal new chrysanthemum species.

Emaraviruses are a genus of plant viruses that have been newly described in the past decade. These viruses, some of which are transmitted by eriophyid mites, are important pathogens of cereals, fruits, and ornamental trees worldwide. This study used sequence data for emaraviruses to design new degenerate primer sets that identify an extensive range of known and unknown emaraviruses. Sequence alignment of the amino acid and nucleotide sequences of RNA-dependent RNA polymerases for 11 accessions among nine emaraviruses confirmed the presence of seven conserved motifs (Pre-A, F, A, B, C, D, and E). Subsequently, new degenerate primers were designed based on motifs F, A, and B, which were the most conserved among the seven motifs. Reverse transcription-polymerase chain reaction using these primers detected known emaraviruses more efficiently than previously known primers. These new primers enabled the identification of a partial nucleotide sequence of a putative novel emaravirus from chrysanthemum leaves showing mosaic or yellowish ringspot symptoms known to be associated with eriophyid mites, Paraphytoptus kikus. These sequences were specifically detected from the symptomatic leaves of a chrysanthemum, and the putative emaravirus was tentatively named chrysanthemum mosaic-associated virus.

[Case of lupus peritonitis with thrombus in the right atrium].

A 24-year-old woman with systemic lupus erythematosus (SLE) was admitted to our hospital because of diarrhea, vomiting, and epigastralgia. When she was diagnosed as SLE 5 years earlier, her renal function was normal and her urine protein excretion was 0.15 g/day. Renal biopsy revealed class V lupus nephritis, and she was treated with intravenous steroid (1 g methylprednisolone per day) for 3 days. The prednisolone dose was then reduced from 30 mg/day to 5 mg/day and maintained at that level until she was admitted to our hospital. Her abdominal X-ray, and CT scan showed massive ascites and excessive colonic gas. She was diagnosed as having ileus resulting from lupus peritonitis. The dose of prednisolone was increased up to 50 mg/day. After 1 week, the ascites disappeared and serum albumin and complement levels, lymphocyte count, and urine protein level returned to the normal range. When the prednisolone dose was reduced to 40 mg, however, UCG and an abdominal CT scan revealed thrombus in her right atrium, and inferior vena cava. Urokinase, argatroban and heparin were administered intravenously and warfarin was administered thereafter. Her thrombus gradually disappeared and she was discharged. These findings suggest that anticoagulation therapy is crucial for SLE patients with multiple complications receiving high-dose steroids.

Observation of the membrane binding activity and domain structure of gpV, which comprises the tail spike of bacteriophage P2.

The P2 phage virion has tail spike proteins beneath the baseplate and uses them to adsorb to the outer membrane of Escherichia coli during the infection process. Previous immunoelectron microscopic studies suggested that the tail spikes are composed of the gene V product (gpV); however, experimental evidence of its membrane binding activity has yet to be reported. In this study, we purified and characterized recombinant full-length gpV and its C-terminal domain. Limited chymotrypsin proteolysis of gpV produced a C-terminal domain composed of Ser86-Leu211. Our experiments demonstrated that the N- and C-terminal domains have very different melting temperatures: 50 and 74 degrees C, respectively. We also found that gpV binds the E. coli membrane via its C-terminal domain. We conclude that the C-terminal domain of gpV is a stable trimer and serves as the receptor-binding domain for the second step in the phage adsorption process.

Antiviral RNA silencing is restricted to the marginal region of the dark green tissue in the mosaic leaves of tomato mosaic virus-infected tobacco plants.

Mosaic is a common disease symptom caused by virus infection in plants. Mosaic leaves of Tomato mosaic virus (ToMV)-infected tobacco plants consist of yellow-green and dark green tissues that contain large and small numbers of virions, respectively. Although the involvement of RNA silencing in mosaic development has been suggested, its role in the process that results in an uneven distribution of the virus is unknown. Here, we investigated whether and where ToMV-directed RNA silencing was established in tobacco mosaic leaves. When transgenic tobaccos defective in RNA silencing were infected with ToMV, little or no dark green tissue appeared, implying the involvement of RNA silencing in mosaic development. ToMV-related small interfering RNAs were rarely detected in the dark green areas of the first mosaic leaves, and their interior portions were susceptible to infection. Thus, ToMV-directed RNA silencing was not effective there. By visualizing the cells where ToMV-directed RNA silencing was active, it was found that the effective silencing occurs only in the marginal regions of the dark green tissue ( approximately 0.5 mm in width) and along the major veins. Further, the cells in the margins were resistant against recombinant potato virus X carrying a ToMV-derived sequence. These findings demonstrate that RNA silencing against ToMV is established in the cells located at the margins of the dark green areas, restricting the expansion of yellow-green areas, and consequently defines the mosaic pattern. The mechanism of mosaic symptom development is discussed in relation to the systemic spread of the virus and RNA silencing.

Evaluation of genetic diversity among 'Candidatus Liberibacter asiaticus' isolates collected in Southeast Asia.

The aim of this study was to investigate the genetic diversity and relationships among 'Candidatus Liberibacter asiaticus' isolates from different hosts and distinct geographical areas in Southeast Asia. Genetic diversity among 'Ca. Liberibacter asiaticus' was estimated by sequencing four well-characterized DNA fragments: the 16S ribosomal DNA (rDNA) and 16S/23S intergenic spacer regions; the outer membrane protein (omp) gene region; the trmU-tufB-secE-nusG-rplKAJL-rpoB region (gene cluster region); and the bacteriophage-type DNA polymerase region. The sequences of the 16S rDNA and 16S/23S intergenic spacer regions were identical among all 'Ca. Liberibacter asiaticus' isolates. In contrast, nucleotide substitutions were observed in both the omp gene and the gene cluster regions. However, extended bacteriophage-type DNA polymerase sequences acquired by thermal asymmetric interlaced polymerase chain reaction provided the most sequence diversity among isolates. Phylogenetic analysis of the bacteriophage-type DNA polymerase sequences revealed three clusters in the Southeast Asian 'Ca. Liberibacter asiaticus' population. All Indonesian 'Ca. Liberibacter asiaticus' isolates clustered in one group. The other clusters were not correlated with geographic distribution. The differences in genetic sequences did not reflect differences in the original citrus host (mandarin or pummelo). These results suggest that the bacteriophage-type DNA polymerase region would be useful for molecular differentiation between different Southeast Asian 'Ca. Liberibacter asiaticus' isolates.