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A Plasmodium falciparum homologue of one of the components of a chromatin-remodelling complex which controls binding of transcription factors to nucleosome core particles has been cloned and characterised. The gene encodes 1422 amino acids with an estimated molecular mass of 167 kDa. The protein, SNF2L, shares 60% amino acid identity in its conserved DNA-dependent ATPase domain with yeast transcription factors originally identified by characterising mating type switch mutants. It also contains sequences related to the so-called SWI3, ADA2, N-CoR and TFIIIB B" or SANT DNA binding domains which are characteristic of these transcriptional activation factors. The SNF2L gene has two short introns in the 3' region of the coding sequence of the gene and is transcribed into a single approximately 6.5 kb messenger RNA species which is present throughout the asexual stages of the cell cycle. Southern blotting and pulsed field gel electrophoresis experiments show that SNF2L is a single copy gene. located on P. falciparum chromosome 11.

We report a case of neurognathostomiasis in a Thai laborer for the first time in Taiwan. For patients with eosinophilic meningitis, neurognathostomiasis should be considered when brain image discloses subarachnoid or intracranial hemorrhage and when an appropriate exposure risk is available, especially a history of raw freshwater fish consumption in endemic areas, even a long time ago.

After bathing at a hot spring resort, a 75-year-old man presented to the emergency department because of seizure-like attack with loss of conscious. This is the first case of primary amebic meningoencephalitis (PAM) caused by Naegleria fowleri in Taiwan. PAM was diagnosed based on detection of actively motile trophozoites in cerebrospinal fluid using a wet-mount smear and the Liu's stain. The amoebae were further confirmed by PCR and gene sequencing. In spite of administering amphotericin B treatment, the patient died 25 days later.

Dear Sir: We read with great interest the article published by Gunther and others1 that describes the amebiasis-related mortality among United States residents from 1990 to 2007. Of 134 amebiasis deaths during the study period, human immunodeficiency virus (HIV) infection was a co-existing condition in 14 (10.4%), which was statistically significantly more common than in the control, non-amebiasis group with a matched odds ratio of 7.7 (95% confidence interval, 3.16–18.77). Although more studies are warranted to identify the causes of the higher association between HIV infection and amebiasis deaths in the United States, the findings of several previous studies between the 1980s and 2000s2–6 concluded infection with Entamoeba histolytica that is pathogenic was rare in men who have sex with men (MSM). Regardless of HIV serostatus, this may hinder health care providers from considering invasive amebiasis high in the list of differential diagnosis when HIV-infected patients present with symptoms of amebic colitis or abscesses that are difficult to be differentiated from other competing causes of colitis or liver abscess.7 Although the spectrum of amebiasis is similar between HIV-infected patients and the general population,8,9 the amebiasis-related mortality rate is low in developed countries where HIV-infected MSM have long been recognized as a high risk group for amebiasis.8,10,11 In the two largest case series of invasive amebiasis in HIV-infected men in Taiwan and Japan, Hung and others8 and Watanabe and others9 retrospectively reviewed 67 and 170 cases of invasive amebiasis, respectively, and the amebiasis-related mortality rate was 0% and 1.2%, respectively, despite a high percentage of amebic abscess and complications. Recent studies that report cases of invasive amebiasis in MSM and bisexuals in other developed countries12,13 and a higher frequency of amebiasis, detected by specific antigen assays for E. histolytica and serologies, in both developed and developing countries14–17 should raise concerns and warrant reevaluation of amebiasis in patients with HIV infection, especially in MSM.

Toxoplasma gondii is an opportunistic, zoonotic pathogen with a worldwide distribution. There are large variations in the seroprevalence of T. gondii infection in different regions of the world. Although toxoplasmosis became a notifiable communicable disease in Taiwan in 2007, little is known about its epidemiology among the general population. This cross-sectional study aimed to survey the seroprevalence of T. gondii infection and its risk factors among healthy blood donors in Taiwan. Through collaborating with the Taiwan Blood Services Foundation, a total of 1,783 healthy blood donors from all six-branch blood service centers participated in this study. The blood samples were tested for the presence of T. gondii antibodies and DNA using enzyme immunoassays and real-time PCR, respectively. Structured questionnaires were used to gather information on risk factors for T. gondii infection. Of the 1,783 participants, 166 (9.3%) tested positive for anti-Toxoplasma IgG, while 5 (0.28%) tested positive for anti-Toxoplasma IgM. The five IgM positive donors had high avidity antibodies suggestive of past infection. No active parasitemia was detected by real-time PCR assays. Multivariate logistic regression showed that undercooked pork meat consumption (adjusted odds ratio [OR] = 2.9; 95% confidence interval [CI]: 1.3-6.5), raw mussels consumption (adjusted OR = 5.3; 95% CI: 1.5-19.1), having a cat in the household (adjusted OR = 2.0; 95% CI: 1.2-3.2), a lower education level (adjusted OR = 1.6; 95% CI: 1.1-2.3), and donation place in eastern Taiwan (adjusted OR = 2.5; 95% CI: 1.6-3.9) were independent risk factors for Toxoplasma seropositivity. These findings provide information on the seroprevalence and epidemiology of T. gondii infection among healthy blood donors in Taiwan.

The high incidences of waterborne diseases are frequently associated with diarrheagenic Escherichia coli (DEC). DEC may pose a health risk to people who contact surface water for recreation or domestic use. However, there is no published report on the monitoring of DEC in drinking water sources in Taiwan. In this study, the occurrence of DEC genes in raw water for water treatment plants in Taiwan was investigated.Raw water samples were taken from water treatment plants adjacent to the Kaoping River in southern Taiwan. Each water sample was treated with membrane filtration followed by DNA extraction from the concentrate and concentrate enrichment, respectively. The target genes for various DEC strains of genes were identified, including enteroaggregative E. coli (EAEC), enterohemorrhagic E. coli (EHEC), enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC), and enterotoxigenic E. coli (ETEC).Among 55 water samples analyzed, DEC genes were detected in 16 (29.1%) samples. Strain-specific genes for EAEC, EHEC, EIEC, and EPEC were found in the percentages of 3.6%, 10.9%, 9.1%, and 9.1%, respectively. The specific gene for ETEC is not detected in the study. By looking at the presence/absence of specific genes and water sample characteristics, water temperature was found to differ significantly between samples with and without EHEC gene. In addition, pH levels differed significantly for EHEC and EPEC presence/absence genes, and turbidity was significantly different for water with and without EPEC genes.DEC genes were detected in 29.1% of the raw water samples in the study location. The potential health threat may be increased if the treatment efficiencies are not properly maintained. Routine monitoring of DEC in drinking water sources should be considered.

Orientia tsutsugamushi is the etiological agent of scrub typhus, a mite-borne, febrile illness that occurs in the Asia-Pacific region. We conducted strain characterization of O. tsutsugamushi isolates from chiggers obtained from rodents based the nucleotide sequence of the 56-kDa outer membrane protein gene. With the use of PCR, a total of 68 DNA sequences of 56-kDa antigen genes were amplified. Phylogenetic analysis revealed that there were at least six definable clusters among the 68 isolates: 37% Karp-related strains (25/68), 27% TA763 strains (18/68), 12% JG-related strains (8/68), 19% Kato-related strains (13/68), 4% divergent strains (3/68), and 1% representing a Gilliam prototype strain (1/68). Overall, the O. tsutsugamushi genotypes exhibited a high degree of diversity, similar to that seen in strains from the rest of the areas where scrub typhus is endemic. Moreover, the 56-kDa protein sequence similarity between O. tsutsugamushi isolates from mites and those from human patients (H. Y. Lu et al., Am. J. Trop. Med. Hyg. 83:658-663, 2010) were striking, thus highlighting potential risk factors for this emerging zoonotic disease.

This case-control study aimed to characterize the factors associated with amebiasis, defined as presence of anti-Entamoeba histolytica antibody titers of ≧ 128 by indirect hemagglutination assay, among persons seeking voluntary counseling and testing (VCT) for human immunodeficiency virus (HIV) infection. Between April 2006 and September 2009, 57 of 4,802 persons (1.2%) seeking VCT services were seropositive for E. histolytica infection. Compared with 228 seronegative controls, case subjects were older (odds ratio [OR] for per 1-year increase, 1.098; 95% confidence interval [CI], 1.036, 1.165), less likely to hold bachelor degree or higher (OR, 0.359; 95% CI, 0.152, 0.846), and were more likely to be men who have sex with men (MSM) (OR, 8.382; 95% CI, 2.050, 34.266) and have oral-anal sex (OR, 4.016; 95% CI, 1.711, 9.427) in multiple logistic regression analysis. The MSM, fecal-oral contamination, lower educational achievement, and older age were associated with increased risk for amebiasis among persons seeking VCT for HIV infection.

Some species of Legionella are recognized as opportunistic potential human pathogens, such as Legionella pneumophila, which causes legionnaires disease. Indeed, outbreaks of legionellosis are frequently reported in areas in which the organism has been spread via aerosols from contaminated institutional water systems. Contamination in hot tubs, spas and public baths are also possible. As a result, in this study, we investigated the distribution of Legionella at six hot spring recreation areas throughout Taiwan. Legionella were detected in all six hot spring recreation areas, as well as in 20 of the 72 samples that were collected (27.8%). Seven species of Legionella identified from samples by the direct DNA extraction method were unidentified Legionella spp., Legionella anisa, L. pneumophila, Legionella erythra, Legionella lytica, Legionella gresilensis and Legionella rubrilucen. Three species of Legionella identified in the samples using the culture method were L. pneumophila, unidentified Legionella spp. and L. erythra. Legionella species were found in water with temperatures ranging from 22.7 °C to 48.6 °C. The optimal pH appeared to range from 5.0 to 8.0. Taken together, the results of this survey confirmed the ubiquity of Legionella in Taiwan spring recreational areas. Therefore, a long-term investigation of the health of workers at hot spring recreational areas and the occurrence of Legionella in hot spring recreational areas throughout Taiwan are needed.

Since the 1970s, no information on simian malaria has been documented in Taiwan, an area that is free from human malaria. To update the prevalence of simian malaria, a molecular-based survey was performed. Blood samples from 286 Formosan macaques ( Macaca cyclopis ) were tested for Plasmodium species by microscopy and nested polymerase chain reaction. Furthermore, the field isolates were characterized by sequencing the 42-kDa fragment of the merozoite surface protein 1 (MSP-1(42)). Of the 286 blood samples analyzed, 7 (2.4%) were positive by microscopy and nested PCR. All malaria-infected Formosan macaques were those collected from southern Taiwan, whereas no evidence of malarial parasites was observed among monkeys from eastern and northern Taiwan. Molecular and phylogenetic analyses based on the asexual stage small subunit ribosomal RNA (SSU rRNA) gene clearly identified these samples as a single infection with Plasmodium inui . Furthermore, phylogenetic analysis of the MSP-1(42) gene showed that the 7 field isolates were closely related to P. inui strains Taiwan I and II, which were obtained from Formosan macaques in 1963. These findings indicate that P. inui is the only cause of simian malaria in Taiwan, has been circulating in Formosan macaques at least for 46 yr, and has a geographic preference for southern Taiwan.

Objective O 6 -methylguanine-DNA methyltransferase (MGMT) ameliorates mutagenic, carcinogenic, and cytotoxic adducts from O 6 -methylguanine in DNA through a direct reversal mechanism. Decreased expression of MGMT has been reported in a variety of human malignant tumors. The purpose of this study was to clarify the correlation of MGMT expression levels in oral squamous cell carcinoma (OSCC) with promoter hypermethylation and with betel quid chewing and cigarette smoking. Study design MGMT protein expression in 63 cases of oral squamous cell carcinoma by immunohistochemistry was investigated. Methylation status of the MGMT was analyzed by methylation-specific PCR. Correlation with clinicopathologic parameters was then tested by statistical analysis. Results MGMT immunohistochemistry revealed nuclear staining in normal epithelium, whereas 47 (75%) of 63 OSCC tumors were devoid of MGMT expression and this was related to tumor cell differentiation. Furthermore, the association between loss of MGMT expression and promoter hypermethylation was significant. Lacking protein expression for MGMT in OSCC was also associated with the use of betel quid. Conclusions The results suggest that the absence of MGMT expression, which would seem to be associated with promoter hypermethylation, is related to betel quid chewing and, thus, in turn, might be a significant event in oral carcinogenesis.

Aims This study aimed to assess the prevalence of amoebiasis among patrons visiting gay saunas in Taiwan. Methods A cross-sectional survey was conducted using questionnaire interview and indirect hemagglutination assays and specific Entamoeba histolytica antigen assays of blood and rectal swab specimens, respectively, among patrons visiting 10 gay saunas between September 2006 and December 2006. Results During the three-month study period, 208 blood and 120 rectal swab specimens were tested for E. histolytica infection. Amoebiasis was detected among 3.8% and 3.3% of the patrons by serologies and antigen assays, respectively. During the latest sexual encounter, more than 70% of the patrons had oral-anogenital sex, and only 20% used condoms during oral-anogenital contact. Conclusion Our findings suggest that there is a potential risk of E. histolytica transmission among the patrons visiting gay saunas who do not practise safe sex consistently in Taiwan.

BackgroundBecause the outcomes and sequelae after different types of brain injury (BI) are variable and difficult to predict, investigations on whether enhanced expressions of BI-associated biomarkers (BIABs), including transforming growth factor β1 (TGF-β1), S100B, glial fibrillary acidic protein (GFAP), neurofilament light chain (NF-L), tissue transglutaminases (tTGs), β-amyloid precursor proteins (AβPP), and tau are present as well as whether impairment of the ubiquitin-proteasome system (UPS) is present have been widely used to help delineate pathophysiological mechanisms in various BIs. Larvae ofToxocara caniscan invade the brain and cause BI in humans and mice, leading to cerebral toxocariasis (CT). Because the parasitic burden is light in CT, it may be too cryptic to be detected in humans, making it difficult to clearly understand the pathogenesis of subtle BI in CT. Since the pathogenesis of murine toxocariasis is very similar to that in humans, it appears appropriate to use a murine model to investigate the pathogenesis of CT.MethodsBIAB expressions and UPS function in the brains of mice inoculated with a single dose of 250T. canisembryonated eggs was investigated from 3 days (dpi) to 8 weeks post-infection (wpi) by Western blotting and RT-PCR.ResultsResults revealed that at 4 and 8 wpi,T. canislarvae were found to have invaded areas around the choroid plexus but without eliciting leukocyte infiltration in brains of infected mice; nevertheless, astrogliosis, an indicator of BI, with 78.9~142.0-fold increases in GFAP expression was present. Meanwhile, markedly increased levels of other BIAB proteins including TGF-β1, S100B, NF-L, tTG, AβPP, and tau, with increases ranging 2.0~12.0-fold were found, although their corresponding mRNA expressions were not found to be present at 8 wpi. Concomitantly, UPS impairment was evidenced by the overexpression of conjugated ubiquitin and ubiquitin in the brain.ConclusionFurther studies are needed to determine whether there is an increased risk of CT progression into neurodegenerative disease because neurodegeneration-associated AβPP and phosphorylated tau emerged in the brain.

Background Incidence of Entamoeba histolytica infection and clinical manifestations and treatment response of invasive amebiasis (IA) in HIV-infected patients have rarely been investigated before. Methodology/Principal Findings At the National Taiwan University Hospital, medical records of HIV-infected patients who received a diagnosis of IA between 1994 and 2005 were reviewed. The incidence of amebiasis was investigated in serial blood and stool samples from 670 and 264 HIV-infected patients, respectively, using serological and specific amebic antigen assays. DNA extracted from stool samples containing E. histolytica were analyzed by PCR, sequenced, and compared. Sixty-four (5.8%) of 1,109 HIV-infected patients had 67 episodes of IA, and 89.1% of them were men having sex with men (MSM). The CD4 count at diagnosis of IA was significantly higher than that of the whole cohort (215 cells/µL vs. 96 cells/µL). Forty episodes (59.7%) were liver abscesses, 52 (77.6%) colitis, and 25 (37.3%) both liver abscesses and colitis. Fever resolved after 3.5 days of metronidazole therapy (range, 1–11 days). None of the patients died. The incidence of E. histolytica infection in MSM was higher than that in other risk groups assessed by serological assays (1.99 per 100 person-years [PY] vs. 0 per 100 PY; p, Author Summary Entamoeba histolytica, morphologically identical to but genetically different from E. dispar and E. moshkovskii, is the causative agent of amebiasis. Recently there have been reports of increased risk for amebiasis among men who have sex with men (MSM) due to oral-anal sexual contact in several developed countries. In this longitudinal follow-up study, the incidence of amebiasis was determined among HIV-infected patients using serological and specific amebic antigen assays. DNA extracted from stool samples containing E. histolytica were analyzed by PCR, sequenced, and compared. Clinical manifestations and treatment response of invasive amebiasis in HIV-infected patients were reviewed. The results demonstrated that HIV-infected MSM were at significantly higher risk of amebiasis than patients from other risk groups. Clustering of E. histolytica isolates by sequencing analyses from geographically unrelated patients suggested person-to-person transmission. Despite immunosuppression, amebic liver abscesses and colitis responded favorably to metronidazole therapy. It is important to investigate in areas of high incidence of both amebiasis and HIV (sub-Saharan Africa) how generalizable these findings are.

A total of 141 independent strains of Pseudomonas aeruginosa with different heterogeneities in the exo gene ( exoS , exoT , exoU , and exoY ) background were examined for their pathogenic roles. Results indicated that the exoU gene is the major contributor to cytotoxicity in Madin-Darby canine kidney cells but is not related to bacterial colonization in mice.

Here we show that blood-stage Plasmodium falciparum organisms accumulate a high mass of triacylglycerol and diacylglycerol. However, we failed to detect cholesterol esters, a second neutral lipid species reported to be important for a related apicomplexan, Toxoplasma gondii . Evidence for P. falciparum and T. gondii homologues of acyl coenzyme A:diacylglycerol acyltransferase suggests that acylglycerols may be the conserved neutral lipids in apicomplexans.

Salmonella enterica serovar Typhimurium ATCC 13311 is virulent at a dose as low as 10(2) colony-forming units when administered intraperitoneally to BALB/c mice. In order to develop highly attenuated mutant strain through the combination of 2 phenotypically attenuated markers, we constructed a number of amino acid requiring auxotrophic strains of S. enterica serovar Typhimurium by means of UV-induced mutations. One of them, strain NDMC-B1, was highly attenuated for mice, with an LD50-value of 6 and 3 log units lower for mice than the wild-type strain and S. enterica serovar Typhimurium aroA strain, respectively. This strain still contained the Salmonella O- and H-antigens but had a requirement for cysteine and was unable to utilize citrate as its sole carbon source. NDMC-B1 colonized the gut-associated lymphoid tissue more efficiently than the wild-type strain, but its capacities to colonize spleen and liver were significantly reduced. Mice intraperitoneally or orally vaccinated with NDMC-B1 were highly protected against either an intraperitoneal challenge with 10(6) colony-forming units or an oral challenge with 10(9) colony-forming units of the wild-type strain. Taken together, the results illustrate that through the combination of 2 independently phenotypical attenuating markers, the requirement for cysteine and the inability to use citrate, we have successfully constructed a highly attenuated, stable, and immunogenic S. enterica serovar Typhimurium vaccine strain which can induce protective immunity in a mouse model against lethal challenge of wild-type strain.

Congenital toxoplasmosis is a major cause of premature delivery and neonatal illness. Here we report a rare case of congenital toxoplasmosis with significant brain tissue loss to highlight the potential threat of congenital toxoplasmosis to neonates. A woman 27 years of age who was pregnant presented with fetal growth restriction at our obstetric clinic on October 12, 2009. Her blood sample was positive for Toxoplasma gondii-specific immunoglobin M (IgM). She gave birth to a boy at 37 weeks of gestation on February 1, 2010. The infant weighed 2050 g and had Apgar scores of 7 and 9 at birth and 5 minutes after birth, respectively. General examination did not show any morphologic abnormality. However, brain magnetic resonance imaging showed diffuse brain tissue loss with direct communication between the lateral ventricle and the adjacent cerebral surface, corpus callosum hypoplasia, porencephaly, encephalomalacia, intracerebral hemorrhage, and multiple calcifications (Fig. 1). Cerebrospinal fluid examination (CSF) showed an increased protein level (148.9 mg/dl); real-time polymerase chain reaction on the CSF sample showed a positive result for T gondii repeat element DNA. Serologic tests

Although recombination is known to be important to generating diversity in the human malaria parasite P. falciparum , the low efficiencies of transfection and the fact that integration of transfected DNA into chromosomes is observed only after long periods (typically 12 weeks or more) have made it difficult to genetically manipulate the blood stages of this major human pathogen. Here we show that co-transfection of a P. falciparum line with two plasmids, one expressing a green fluorescent protein ( gfp ) reporter and the other expressing a drug resistance marker ( Tgdhfr-ts M23), allowed selection of a population in which about ∼30% of the parasites produce GFP. In these GFP-producing parasites, the transfected plasmids had recombined into chimeric episomes as large as 20 kb and could be maintained under drug pressure for at least 16 weeks. Our data suggest that chimera formation occurs early (detected by 7–14 days) and that it involves homologous recombination favored by presence of the same P. falciparum 5′hrp3 UTR promoting transcription from each plasmid. This indicates the presence of high levels of homologous recombination activity in blood stage parasites that can be used to drive rapid recombination of newly introduced DNA, study mechanisms of recombination, and introduce genes for trans expression in P. falciparum .

Keywords: Cell Cycle Proteins ; Guanine Nucleotide Exchange Factors Reference EPFL-ARTICLE-148125doi:10.1016/S0166-6851(98)00107-8 Record created on 2010-04-07, modified on 2016-08-08

A process for production, isolation, and purification of melanin produced by the fermentation of Streptomyces lividans 66 harboring a recombinant plasmid pIJ702-bearing tyrosinase gene has been developed. The efficacy of melanin in the protection of mosquito larvacidal activity of Bacillus thuringiensis var. israelensis against uv light has been studied. Results obtained by the live cell counts and the bioassay of residual mosquitocidal activity of B. thuringiensis var. israelensis after exposure to uv radiation showed that melanin is an excellent photoprotective agent.