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1.
S Afr Med J ; 110(6): 502-504, 2020 May 29.
Article in English | MEDLINE | ID: mdl-32880562

ABSTRACT

BACKGROUND: South Africa (SA) has a high disease burden of HIV/AIDS. Previously, studies have shown that HIV-infected women have adverse pregnancy outcomes. OBJECTIVES: To determine the effect of HIV infection on neonatal birthweight, head circumference, birth length and duration of pregnancy. METHODS: This was a retrospective study, and data were obtained from the maternity records of women who delivered at Stanger Hospital, SA, from August to December 2016. Pregnancies were dated using an early ultrasound scan. Women with comorbidities that are known to affect birth anthropometry were excluded, as well as all self-reported smokers. Women were divided into HIV-infected and HIV-non-infected groups and compared. RESULTS: Among the 392 women included in the cohort, 171 (43.6%) were HIV-infected and 221 (56.4%) were non-infected. All HIV-infected women were receiving antiretroviral therapy. There was no significant difference in neonatal birthweight, head circumference, birth length or duration of pregnancy between the groups. CONCLUSIONS: HIV infection that has been treated does not appear to be an independent risk factor for fetal growth restriction or preterm delivery in an SA population.


Subject(s)
Fetal Growth Retardation/epidemiology , HIV Infections/complications , HIV Infections/epidemiology , Pregnancy Complications, Infectious/epidemiology , Adult , Birth Weight , Body Height , Female , Gestational Age , Head/anatomy & histology , Humans , Infant, Newborn , Pregnancy , Pregnancy Outcome , Retrospective Studies , Risk Factors , South Africa/epidemiology
2.
mSphere ; 5(2)2020 04 08.
Article in English | MEDLINE | ID: mdl-32269157

ABSTRACT

The filamentous fungus Aspergillus nidulans has been a primary workhorse used to understand fungal genetics. Much of this work has focused on elucidating the genetics of biosynthetic gene clusters (BGCs) and the secondary metabolites (SMs) they produce. SMs are both niche defining in fungi and of great economic importance to humans. Despite the focus on A. nidulans, very little is known about the natural diversity in secondary metabolism within this species. We determined the BGC content and looked for evolutionary patterns in BGCs from whole-genome sequences of two clinical isolates and the A4 reference genome of A. nidulans Differences in BGC content were used to explain SM profiles determined using liquid chromatography-high-resolution mass spectrometry. We found that in addition to genetic variation of BGCs contained by all isolates, nine BGCs varied by presence/absence. We discovered the viridicatumtoxin BGC in A. nidulans and suggest that this BGC has undergone a horizontal gene transfer from the Aspergillus section Nigri lineage into Penicillium sometime after the sections Nigri and Nidulantes diverged. We identified the production of viridicatumtoxin and several other compounds previously not known to be produced by A. nidulans One isolate showed a lack of sterigmatocystin production even though it contained an apparently intact sterigmatocystin BGC, raising questions about other genes and processes known to regulate this BGC. Altogether, our work uncovers a large degree of intraspecies diversity in BGC and SM production in this genetic model species and offers new avenues to understand the evolution and regulation of secondary metabolism.IMPORTANCE Much of what we know about the genetics underlying secondary metabolite (SM) production and the function of SMs in the model fungus Aspergillus nidulans comes from a single reference genome. A growing body of research indicates the importance of biosynthetic gene cluster (BGC) and SM diversity within a species. However, there is no information about the natural diversity of secondary metabolism in A. nidulans We discovered six novel clusters that contribute to the considerable variation in both BGC content and SM production within A. nidulans We characterize a diverse set of mutations and emphasize how findings of single nucleotide polymorphisms (SNPs), deletions, and differences in evolutionary history encompass much of the variation observed in nonmodel systems. Our results emphasize that A. nidulans may also be a strong model to use within-species diversity to elucidate regulatory cross talk, fungal ecology, and drug discovery systems.


Subject(s)
Aspergillosis/microbiology , Aspergillus nidulans/genetics , Aspergillus nidulans/metabolism , Multigene Family , Secondary Metabolism , Fungal Proteins/genetics , Gene Expression Regulation, Fungal , Gene Transfer, Horizontal , Genetic Variation , Genome, Fungal , Mutation , Sterigmatocystin/biosynthesis
3.
Anal Biochem ; 530: 5-8, 2017 08 01.
Article in English | MEDLINE | ID: mdl-28461174

ABSTRACT

Simplified methods to assemble DNA fragments by independent cloning sequence have helped in the progress of synthetic biology, allowing some biotechnological processes to become economically viable by genetic improvement of microorganisms. We compared three methods of assembling six DNA fragments: PCR fusion-based, isothermal NEBuilder and circular polymerase extension cloning (CPEC). Double and triple fusion occurs directly with the PCR products using PCR fusion-based and NEBuilder methods. For multiple fragments the results showed higher efficiency by the CPEC method which allowed assembly of six fragments previously purified by agarose gel extraction, after a sequence of 20 annealing/extension cycles without any primer.


Subject(s)
Cloning, Molecular/methods , DNA/chemistry , DNA/genetics , Polymerase Chain Reaction/methods , Synthetic Biology/methods , Ligases/metabolism , Transformation, Genetic
4.
Mol Microbiol ; 102(3): 488-505, 2016 11.
Article in English | MEDLINE | ID: mdl-27479571

ABSTRACT

C8-desaturated and C9-methylated glucosylceramide (GlcCer) is a fungal-specific sphingolipid that plays an important role in the growth and virulence of many species. In this work, we investigated the contribution of Aspergillus nidulans sphingolipid Δ8-desaturase (SdeA), sphingolipid C9-methyltransferases (SmtA/SmtB) and glucosylceramide synthase (GcsA) to fungal phenotypes, sensitivity to Psd1 defensin and Galleria mellonella virulence. We showed that ΔsdeA accumulated C8-saturated and unmethylated GlcCer, while gcsA deletion impaired GlcCer synthesis. Although increased levels of unmethylated GlcCer were observed in smtA and smtB mutants, ΔsmtA and wild-type cells showed a similar 9,Me-GlcCer content, reduced by 50% in the smtB disruptant. The compromised 9,Me-GlcCer production in the ΔsmtB strain was not accompanied by reduced filamentation or defects in cell polarity. When combined with the smtA deletion, smtB repression significantly increased unmethylated GlcCer levels and compromised filamentous growth. Furthermore, sdeA and gcsA mutants displayed growth defects and raft mislocalization, which were accompanied by reduced neutral lipids levels and attenuated G. mellonella virulence in the ΔgcsA strain. Finally, ΔsdeA and ΔgcsA showed increased resistance to Psd1, suggesting that GlcCer synthesis and fungal sphingoid base structure specificities are relevant not only to differentiation but also to proper recognition by this antifungal defensin.


Subject(s)
Aspergillus nidulans/metabolism , Glucosylceramides/metabolism , Glucosyltransferases/metabolism , Membrane Microdomains/metabolism , Antifungal Agents/chemistry , Aspergillus nidulans/genetics , Aspergillus nidulans/growth & development , Defensins/metabolism , Glucosylceramides/chemistry , Glucosylceramides/genetics , Glucosyltransferases/chemistry , Glucosyltransferases/genetics , Methylation , Methyltransferases/genetics , Oxidoreductases/metabolism , Sphingolipids/chemistry , Sphingolipids/metabolism
7.
Hum Exp Toxicol ; 33(8): 886-93, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24275643

ABSTRACT

BACKGROUND: There is increasing evidence that herpes zoster (HZ) incidence rates among children and adults (aged <60 years) with a history of natural varicella are influenced primarily by the frequency of exogenous exposures, while asymptomatic endogenous reactivations help to cap the rate at approximately 550 cases/100,000 person-years when exogenous boosting becomes rare. The Antelope Valley Varicella Active Surveillance Project was funded by the Centers for Disease Control and Prevention in 1995 to monitor the effects of varicella vaccination in one of the three representative regions of the United States. The stability in the data collection and number of reporting sites under varicella surveillance from 1995-2002 and HZ surveillance during 2000-2001 and 2006-2007 contributed to the robustness of the discerned trends. DISCUSSION: Varicella vaccination may be useful for leukemic children; however, the target population in the United States is all children. Since the varicella vaccine inoculates its recipients with live, attenuated varicella-zoster virus (VZV), clinical varicella cases have dramatically declined. Declining exogenous exposures (boosts) from children shedding natural VZV have caused waning cell-mediated immunity. Thus, the protection provided by varicella vaccination is neither lifelong nor complete. Moreover, dramatic increases in the incidence of adult shingles cases have been observed since HZ was added to the surveillance in 2000. In 2013, this topic is still debated and remains controversial in the United States. SUMMARY: When the costs of the booster dose for varicella and the increased shingles recurrences are included, the universal varicella vaccination program is neither effective nor cost-effective.


Subject(s)
Chickenpox Vaccine/therapeutic use , Chickenpox/prevention & control , Herpes Zoster/prevention & control , Immunization Programs , Vaccination , Adult , Chickenpox/diagnosis , Chickenpox/economics , Chickenpox/epidemiology , Chickenpox/immunology , Chickenpox/virology , Chickenpox Vaccine/adverse effects , Chickenpox Vaccine/economics , Child , Child, Preschool , Cost-Benefit Analysis , Drug Costs , Evidence-Based Medicine , Herpes Zoster/diagnosis , Herpes Zoster/economics , Herpes Zoster/epidemiology , Herpes Zoster/immunology , Herpes Zoster/virology , Herpes Zoster Vaccine/therapeutic use , Herpesvirus 3, Human/drug effects , Herpesvirus 3, Human/immunology , Herpesvirus 3, Human/pathogenicity , Humans , Immunization Programs/economics , Incidence , Infant , Program Evaluation , Time Factors , Treatment Outcome , United States/epidemiology , Vaccination/adverse effects , Vaccination/economics , Virus Activation
8.
Vaccine ; 31(13): 1680-94, 2013 Mar 25.
Article in English | MEDLINE | ID: mdl-22659447

ABSTRACT

In a cooperative agreement starting January 1995, prior to the FDA's licensure of the varicella vaccine on March 17, the Centers for Disease Control and Prevention (CDC) funded the Los Angeles Department of Health Services' Antelope Valley Varicella Active Surveillance Project (AV-VASP). Since only varicella case reports were gathered, baseline incidence data for herpes zoster (HZ) or shingles was lacking. Varicella case reports decreased 72%, from 2834 in 1995 to 836 in 2000 at which time approximately 50% of children under 10 years of age had been vaccinated. Starting in 2000, HZ surveillance was added to the project. By 2002, notable increases in HZ incidence rates were reported among both children and adults with a prior history of natural varicella. However, CDC authorities still claimed that no increase in HZ had occurred in any US surveillance site. The basic assumptions inherent to the varicella cost-benefit analysis ignored the significance of exogenous boosting caused by those shedding wild-type VZV. Also ignored was the morbidity associated with even rare serious events following varicella vaccination as well as the morbidity from increasing cases of HZ among adults. Vaccine efficacy declined below 80% in 2001. By 2006, because 20% of vaccinees were experiencing breakthrough varicella and vaccine-induced protection was waning, the CDC recommended a booster dose for children and, in 2007, a shingles vaccination was approved for adults aged 60 years and older. In the prelicensure era, 95% of adults experienced natural chickenpox (usually as children)-these cases were usually benign and resulted in long-term immunity. Varicella vaccination is less effective than the natural immunity that existed in prevaccine communities. Universal varicella vaccination has not proven to be cost-effective as increased HZ morbidity has disproportionately offset cost savings associated with reductions in varicella disease. Universal varicella vaccination has failed to provide long-term protection from VZV disease.


Subject(s)
Chickenpox Vaccine/administration & dosage , Chickenpox Vaccine/immunology , Herpes Zoster/epidemiology , Herpes Zoster/prevention & control , Vaccination/economics , Vaccination/statistics & numerical data , Chickenpox/epidemiology , Chickenpox/prevention & control , Chickenpox Vaccine/economics , Cost-Benefit Analysis , Humans , Incidence , United States/epidemiology
9.
Hum Exp Toxicol ; 32(5): 464-75, 2013 May.
Article in English | MEDLINE | ID: mdl-23023030

ABSTRACT

The aim of this study was to compare the number of inactivated-influenza vaccine-related spontaneous abortion and stillbirth (SB) reports in the Vaccine Adverse Event Reporting System (VAERS) database during three consecutive flu seasons beginning 2008/2009 and assess the relative fetal death reports associated with the two-vaccine 2009/2010 season. The VAERS database was searched for reports of fetal demise following administration of the influenza vaccine/vaccines to pregnant women. Utilization of an independent surveillance survey and VAERS, two-source capture-recapture analysis estimated the reporting completeness in the 2009/2010 flu season. Capture-recapture demonstrated that the VAERS database captured about 13.2% of the total 1321 (95% confidence interval (CI): 815-2795) estimated reports, yielding an ascertainment-corrected rate of 590 fetal-loss reports per million pregnant women vaccinated (or 1 per 1695). The unadjusted fetal-loss report rates for the three consecutive influenza seasons beginning 2008/2009 were 6.8 (95% CI: 0.1-13.1), 77.8 (95% CI: 66.3-89.4), and 12.6 (95% CI: 7.2-18.0) cases per million pregnant women vaccinated, respectively. The observed reporting bias was too low to explain the magnitude increase in fetal-demise reporting rates in the VAERS database relative to the reported annual trends. Thus, a synergistic fetal toxicity likely resulted from the administration of both the pandemic (A-H1N1) and seasonal influenza vaccines during the 2009/2010 season.


Subject(s)
Adverse Drug Reaction Reporting Systems , Fetal Death/etiology , Influenza A Virus, H1N1 Subtype/immunology , Influenza Vaccines/adverse effects , Adult , Female , Humans , Pregnancy , Seasons , Time Factors
10.
Hum Exp Toxicol ; 31(10): 1012-21, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22531966

ABSTRACT

In this study, the Vaccine Adverse Event Reporting System (VAERS) database, 1990-2010, was investigated; cases that specified either hospitalization or death were identified among 38,801 reports of infants. Based on the types of vaccines reported, the actual number of vaccine doses administered, from 1 to 8, was summed for each case. Linear regression analysis of hospitalization rates as a function of (a) the number of reported vaccine doses and (b) patient age yielded a linear relationship with r(2) = 0.91 and r(2) = 0.95, respectively. The hospitalization rate increased linearly from 11.0% (107 of 969) for 2 doses to 23.5% (661 of 2817) for 8 doses and decreased linearly from 20.1% (154 of 765) for children aged <0.1 year to 10.7% (86 of 801) for children aged 0.9 year. The rate ratio (RR) of the mortality rate for 5-8 vaccine doses to 1-4 vaccine doses is 1.5 (95% confidence interval (CI), 1.4-1.7), indicating a statistically significant increase from 3.6% (95% CI, 3.2-3.9%) deaths associated with 1-4 vaccine doses to 5.5% (95% CI, 5.2-5.7%) associated with 5-8 vaccine doses. The male-to-female mortality RR was 1.4 (95% CI, 1.3-1.5). Our findings show a positive correlation between the number of vaccine doses administered and the percentage of hospitalizations and deaths. Since vaccines are given to millions of infants annually, it is imperative that health authorities have scientific data from synergistic toxicity studies on all combinations of vaccines that infants might receive. Finding ways to increase vaccine safety should be the highest priority.


Subject(s)
Adverse Drug Reaction Reporting Systems/trends , Hospitalization/trends , Infant Mortality/trends , Vaccination/trends , Vaccines/adverse effects , Age Factors , Analysis of Variance , Dose-Response Relationship, Drug , Drug Interactions , Female , Humans , Immunization Schedule , Infant , Infant, Newborn , Linear Models , Male , Odds Ratio , Risk Assessment , Risk Factors , Time Factors , Vaccination/adverse effects , Vaccination/mortality , Vaccines/administration & dosage
11.
Genet Mol Res ; 9(1): 484-505, 2010 Mar 16.
Article in English | MEDLINE | ID: mdl-20391333

ABSTRACT

The plant hormones jasmonic acid and methyl jasmonate, along with their intermediate compounds, produced in the octadecanoid pathway, are important signaling molecules that are collectively called jasmonates. These are widespread in the plant kingdom and play crucial roles in biotic/abiotic stress responses, as well as in processes related to plant growth and development. Recently, it has been shown that jasmonates are also involved in reproductive processes. We present the most recent findings related to the biosynthesis, regulation and signaling mechanisms of jasmonates. Additionally, we discuss the identification of [(+)-7-iso-JA-L-Ile] as the active biological hormonal form of jasmonate; this fills the greatest gap in our knowledge about the signaling mechanism that is responsible for the activation of downstream genes in the jasmonate-signaling cascade. The identification of several Arabidopsis thaliana mutants was crucial to the elucidation of the signaling mechanisms involved in jasmonate-mediated responses. Finally, the involvement of jasmonates in the reproductive process of Nicotiana tabacum L. is briefly discussed, since some of the main enzymes of the jasmonic acid biosynthesis pathway were identified in a stigma/style expressed sequence tag database (TOBEST) of this Solanaceae species.


Subject(s)
Cyclopentanes/metabolism , Oxylipins/metabolism , Plant Growth Regulators/metabolism , Plants/immunology , Plants/metabolism , Amino Acid Sequence , Cyclopentanes/chemistry , Molecular Sequence Data , Oxylipins/chemistry , Plant Growth Regulators/chemistry , Plant Proteins/chemistry , Plant Proteins/genetics , Plant Proteins/metabolism , Plants/genetics , Plants, Genetically Modified , Reproduction , Signal Transduction
12.
Fungal Genet Biol ; 46(12): 919-26, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19686860

ABSTRACT

Paracoccidioides brasiliensis is characterized by a multiple budding phenotype and a polymorphic cell growth, leading to the formation of cells with extreme variations in shape and size. Since Cdc42 is a pivotal molecule in establishing and maintaining polarized growth for diverse cell types, as well as during pathogenesis of certain fungi, we evaluated its role during cell growth and virulence of the yeast-form of P. brasiliensis. We used antisense technology to knock-down PbCDC42's expression in P. brasiliensis yeast cells, promoting a decrease in cell size and more homogenous cell growth, altering the typical polymorphism of wild-type cells. Reduced expression levels also lead to increased phagocytosis and decreased virulence in a mouse model of infection. We provide genetic evidences underlying Pbcdc42p as an important protein during host-pathogen interaction and the relevance of the polymorphic nature and cell size in the pathogenesis of P. brasiliensis.


Subject(s)
Fungal Proteins/metabolism , Paracoccidioides/cytology , Paracoccidioides/pathogenicity , Paracoccidioidomycosis/microbiology , cdc42 GTP-Binding Protein/metabolism , Animals , Cells, Cultured , Fungal Proteins/genetics , Gene Expression Regulation, Fungal , Genes, Fungal , Host-Pathogen Interactions , Macrophages/immunology , Macrophages/microbiology , Mice , Mice, Inbred C57BL , Paracoccidioides/genetics , Paracoccidioides/physiology , Phagocytosis , RNA, Antisense , Virulence , cdc42 GTP-Binding Protein/genetics
14.
Tech Coloproctol ; 9(3): 206-8, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16328128

ABSTRACT

BACKGROUND: Closure of ileostomy is considered a contaminated operation. The infection rate of the stoma wound is > or = 30%. Several ileostomy-closure techniques intended to reduce the high rate of infection have been described in the literature. Among them, delayed primary closure of the stoma wound is a commonly used method that was reported to reduce the infection rate according to several retrospective studies. We therefore conducted the first prospective randomized trial comparing primary with delayed primary closure of a stoma wound. METHODS: During 2003, 40 patients were admitted to our ward for closure of ileostomy. The ileostomies were taken down by the same team using the same surgical technique except for the technique of wound closure. We randomly divided the patients into two groups. In Group 1 (n = 20), the wound was left open for delayed primary closure and not closed until postoperative day 4. In Group 2, the wound was primarily closed at the end of the procedure. RESULTS: The total wound infection rate was relatively low (15%). Infection occurred more frequently (4 cases, 20%) in Group 1 than in Group 2 (2 cases, 10%). The length of hospital stay was similar for both groups. CONCLUSIONS: In this first prospective comparison of two techniques during ileostomy take down, primary closure unexpectedly produced less wound infection than delayed primary closure.


Subject(s)
Ileostomy/adverse effects , Ileum/surgery , Reoperation/adverse effects , Reoperation/methods , Adolescent , Adult , Age Distribution , Aged , Aged, 80 and over , Female , Follow-Up Studies , Humans , Ileostomy/methods , Incidence , Male , Middle Aged , Prospective Studies , Reference Values , Risk Assessment , Sex Distribution , Surgical Wound Infection/epidemiology , Surgical Wound Infection/prevention & control , Time Factors , Treatment Outcome , Wound Healing/physiology
15.
Med Mycol ; 43 Suppl 1: S313-9, 2005 May.
Article in English | MEDLINE | ID: mdl-16110826

ABSTRACT

The continuous use of triazoles can result in the development of drug resistance. Azole-resistant clinical isolates, spontaneous and induced mutants of Aspergillus fumigatus have been documented. The azoles block the ergosterol biosynthesis pathway by inhibiting the enzyme 14-alpha-demethylase, product of the CYP51. Fungal azole resistance involves both amino acid changes in the target site that alter drug-target interactions and those that decrease net azole accumulation. The reduced intracellular accumulation has also been correlated with overexpression of multidrug resistance (MDR) efflux transporter genes of the ATP-binding cassette (ABC) and the major facilitator superfamily (MFS) classes. About 20 genes are involved in the A. fumigatus ergosterol biosynthesis pathway. There are several duplicated genes in this pathway. Interestingly, erg3 and erg11 showed two copies in A. fumigatus. In general, Aspergillus spp. have proportionally more MFS transporter encoding genes than Saccharomyces cerevisiae, S. pombe, and Neurospora crassa. The drug H+ (12 and 14 spanners) sub-families are also proportionally greater than in the other species. Although the numbers of ABC transporter encoding genes are comparable, again the Aspergillus spp. have more ABC transporters related to multidrug permease than the other fungal species.


Subject(s)
ATP-Binding Cassette Transporters/metabolism , Aspergillus fumigatus/drug effects , Drug Resistance, Fungal , Ergosterol/biosynthesis , ATP-Binding Cassette Transporters/genetics , Antifungal Agents/pharmacology , Aspergillus fumigatus/genetics , Aspergillus fumigatus/metabolism , Azoles/pharmacology , Fungal Proteins/genetics , Fungal Proteins/metabolism , Humans , Microbial Sensitivity Tests
16.
Vaccine ; 23(25): 3349-55, 2005 May 09.
Article in English | MEDLINE | ID: mdl-15837242

ABSTRACT

Many models concur that universal varicella vaccination of children is beneficial from the perspective of reducing societal costs. Yet, the majority of such cost analyses have been modeled under the assumption that varicella vaccination has no adverse effect on the closely related herpes-zoster (HZ) epidemiology. Historical models have assumed that asymptomatic endogenous reactivation is the chief mechanism of boosting that suppresses the reactivation of HZ and that immunity wanes due to the aging process. Recent studies suggest instead that periodic exogenous exposures to wild-type varicella are the predominant factor influencing the curve of increasing HZ incidence rate with advancing age among individuals <50, after which an age-related decline dominates in the elderly. Based on a realistic age-structured model, we compare differences in outcomes of the number of HZ cases and direct medical costs associated with the population existing in 2000 and as it ages (according to the mortality given in the 2000 U.S. census) during the following 50 years with and without implementation of universal varicella vaccination. Under universal varicella vaccination, we assume that 15 years post-licensure, the boosting mechanism known as asymptomatic endogenous reactivation principally serves to limit HZ incidence to 550 per 100,000 person-years in unvaccinated individuals <50 with a previous history of natural varicella--since there has been a vaccine-induced decline in exogenous boosting. We estimate universal varicella vaccination has the impact of an additional 14.6 million (42%) HZ cases among adults aged <50 years during a 50 year time span at a substantial cost burden of 4.1 billion US dollars or 80 million US dollars annually utilizing an estimated mean healthcare provider cost of 280 US dollars per HZ case.


Subject(s)
Chickenpox/economics , Chickenpox/prevention & control , Herpes Zoster/economics , Herpes Zoster/epidemiology , Adolescent , Adult , Aged , Aged, 80 and over , Chickenpox/complications , Child , Cost Savings , Epidemiologic Methods , Herpes Zoster/etiology , Humans , Immunization, Secondary/economics , Mass Vaccination/economics , Middle Aged , Models, Statistical , United States/epidemiology
17.
Mol Genet Genomics ; 271(6): 667-77, 2004 Jul.
Article in English | MEDLINE | ID: mdl-15138890

ABSTRACT

Paracoccidioides brasiliensis, a thermodimorphic fungus, is the causative agent of paracoccidioidomycosis (PCM), the most prevalent systemic mycosis in Latin America. Pathogenicity appears to be intimately related to the dimorphic transition from the hyphal to the yeast form, which is induced by a shift from environmental temperature to the temperature of the mammalian host. Little information is available on the P. brasiliensis genes that are necessary during the pathogenic phase. We have therefore undertaken Suppression Subtraction Hybridization (SSH) and macroarray analyses with the aim of identifying genes that are preferentially expressed in the yeast phase. Genes identified by both procedures as being more highly expressed in the yeast phase are involved in basic metabolism, signal transduction, growth and morphogenesis, and sulfur metabolism. In order to test whether the observed changes in gene expression reflect the differences between the growth conditions used to obtain the two morphological forms rather than differences intrinsic to the cell types, we performed real-time RT-PCR experiments using RNAs derived from both yeast cells and mycelia that had been cultured at 37 degrees C and 26 degrees C in either complete medium (YPD or Sabouraud) or minimal medium. Twenty genes, including AGS1 (alpha-1,3-glucan synthase) and TSA1 (thiol-specific antioxidant), were shown to be more highly expressed in the yeast cells than in the hyphae. Although their levels of expression could be different in rich and minimal media, there was a general tendency for these genes to be more highly expressed in the yeast cells.


Subject(s)
DNA, Complementary/analysis , DNA, Fungal/analysis , Gene Expression Profiling , Genes, Fungal/physiology , Paracoccidioides/genetics , DNA, Complementary/isolation & purification , Gene Expression Regulation, Fungal , Nucleic Acid Hybridization , Reverse Transcriptase Polymerase Chain Reaction , Saccharomyces cerevisiae/genetics , Subtraction Technique
18.
Colorectal Dis ; 6(3): 206-9, 2004 May.
Article in English | MEDLINE | ID: mdl-15109389

ABSTRACT

OBJECTIVE: Perianal Paget's disease (PPD) is a rare entity. The standard treatment for either in situ or invasive extra mammary Paget's disease (EMPD) is surgical excision. Local recurrence and morbidity from surgery, especially in the elderly, can, however, be high. The aim of this article is to review our experience with PPD and question the currently preferred treatment approaches in light of its histopathology and therapeutic outcome. PATIENTS AND METHODS: A chart review of our patients with PPD from 1996 to 2002 was carried out to determine their outcome after treatment. Data from review of the literature are presented. RESULTS: Five patients with in situ disease (four females, median age 68 years) were diagnosed as having PPD. A complete surgical excision was attempted in 4 patients and the fifth was treated by photodynamic therapy. At present, all patients are alive, two are free of disease, one has persistent disease and two have local recurrence. CONCLUSION: Considering the significant rate of recurrence even after wide local excision, the extent of surgery needed and the good prognosis with long-term survival, we question whether nonsurgical modalities should be considered in place of surgery as primary treatment for noninvasive PPD, with radical surgery being reserved for failures or invasive disease.


Subject(s)
Paget Disease, Extramammary/drug therapy , Paget Disease, Extramammary/surgery , Skin Neoplasms/drug therapy , Skin Neoplasms/surgery , Adult , Aged , Anal Canal , Antineoplastic Agents/therapeutic use , Female , Follow-Up Studies , Humans , Male , Middle Aged , Neoplasm Recurrence, Local/drug therapy , Paget Disease, Extramammary/pathology , Photochemotherapy , Photosensitizing Agents/therapeutic use , Retrospective Studies , Skin Neoplasms/pathology , Treatment Outcome
19.
J Bacteriol ; 186(7): 2164-72, 2004 Apr.
Article in English | MEDLINE | ID: mdl-15028702

ABSTRACT

Leptospira species colonize a significant proportion of rodent populations worldwide and produce life-threatening infections in accidental hosts, including humans. Complete genome sequencing of Leptospira interrogans serovar Copenhageni and comparative analysis with the available Leptospira interrogans serovar Lai genome reveal that despite overall genetic similarity there are significant structural differences, including a large chromosomal inversion and extensive variation in the number and distribution of insertion sequence elements. Genome sequence analysis elucidates many of the novel aspects of leptospiral physiology relating to energy metabolism, oxygen tolerance, two-component signal transduction systems, and mechanisms of pathogenesis. A broad array of transcriptional regulation proteins and two new families of afimbrial adhesins which contribute to host tissue colonization in the early steps of infection were identified. Differences in genes involved in the biosynthesis of lipopolysaccharide O side chains between the Copenhageni and Lai serovars were identified, offering an important starting point for the elucidation of the organism's complex polysaccharide surface antigens. Differences in adhesins and in lipopolysaccharide might be associated with the adaptation of serovars Copenhageni and Lai to different animal hosts. Hundreds of genes encoding surface-exposed lipoproteins and transmembrane outer membrane proteins were identified as candidates for development of vaccines for the prevention of leptospirosis.


Subject(s)
Genome, Bacterial , Genomics , Leptospira interrogans/physiology , Leptospira interrogans/pathogenicity , Animals , Bacterial Proteins/chemistry , Bacterial Proteins/genetics , Cricetinae , Humans , Leptospira interrogans/classification , Leptospira interrogans/genetics , Leptospirosis/microbiology , Mice , Molecular Sequence Data , Sequence Analysis, DNA , Serotyping , Virulence/genetics
20.
Can J Microbiol ; 50(9): 767-70, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15644931

ABSTRACT

A vancomycin-resistant Enterococcus (VRE) was isolated from a blood culture of a patient in a Brazilian hospital who had a treatment history of a bone marrow transplant in the USA. The organism was identified as Enterococcus faecium, which exhibited an MIC (minimum inhibitory concentration) >or= 256 microg/mL for vancomycin. This was confirmed by E-test and the vanA gene was detected by PCR. Overlapping PCR revealed a left IR deletion and an additional 1.5 kb fragment between vanSH genes. DdeI digestion of vanRSHAX genes showed the determinant to be a T type variant, and the element was cloned and sequenced. These results revealed an IS1251 downstream of nucleotide 5820 of the VanA element. Insertions like this have not been reported previously in Brazil, but have been detected in the USA. The genotype and association with a patient previously treated in the USA suggest that this VRE was introduced from abroad, probably through inter-hospital strain spread.


Subject(s)
Bacterial Proteins/genetics , Carbon-Oxygen Ligases/genetics , Enterococcus faecium/classification , Transportation of Patients , Vancomycin Resistance , Aged , Bone Marrow Transplantation/adverse effects , Brazil , DNA Transposable Elements , Enterococcus faecium/drug effects , Enterococcus faecium/genetics , Female , Gram-Positive Bacterial Infections/microbiology , Humans , Microbial Sensitivity Tests , Molecular Sequence Data , Sequence Analysis, DNA , United States
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