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1.
J Neonatal Perinatal Med ; 16(3): 507-516, 2023.
Article in English | MEDLINE | ID: mdl-37718859

ABSTRACT

BACKGROUND: Neonates admitted to the neonatal intensive care unit (NICU) are at risk for healthcare-associated infections, including central line-associated bloodstream infections. We aimed to characterize the epidemiology of bloodstream infections among neonates with central venous catheters admitted to three Indian NICUs. METHODS: We conducted a prospective cohort study in three tertiary NICUs, from May 1, 2017 until July 31, 2019. All neonates admitted to the NICU were enrolled and followed until discharge, transfer, or death. Cases were defined as positive blood cultures in neonates with a central venous catheter in place for greater than 2 days or within 2 days of catheter removal. RESULTS: During the study period, 140 bloodstream infections were identified in 131 neonates with a central venous catheter. The bloodstream infection rate was 11.9 per 1000 central line-days. Gram-negative organisms predominated, with 38.6% of cases caused by Klebsiella spp. and 14.9% by Acinetobacter spp. Antimicrobial resistance was prevalent among Gram-negative isolates, with 86.9% resistant to third- or fourth-generation cephalosporins, 63.1% to aminoglycosides, 61.9% to fluoroquinolones, and 42.0% to carbapenems. Mortality and length of stay were greater in neonates with bloodstream infection than in neonates without bloodstream infection (unadjusted analysis, p < 0.001). CONCLUSIONS: We report a high bloodstream infection rate among neonates with central venous catheters admitted to three tertiary care NICUs in India. Action to improve infection prevention and control practices in the NICU is needed to reduce the morbidity and mortality associated with BSI in this high-risk population.


Subject(s)
Catheter-Related Infections , Catheterization, Central Venous , Central Venous Catheters , Cross Infection , Sepsis , Infant, Newborn , Humans , Intensive Care Units, Neonatal , Central Venous Catheters/adverse effects , Prospective Studies , India/epidemiology , Cross Infection/etiology , Catheter-Related Infections/epidemiology , Catheterization, Central Venous/adverse effects
2.
Int J Tuberc Lung Dis ; 23(4): 514-521, 2019 04 01.
Article in English | MEDLINE | ID: mdl-31064632

ABSTRACT

OBJECTIVE To examine tuberculosis (TB) treatment outcomes from a long-term TB-HIV (human immunodeficiency virus) integrated model of care at the Infectious Diseases Institute Clinic, Kampala, Uganda. METHODS We included HIV-positive adults who were new TB cases initiated on anti-tuberculosis treatment between 2009 and 2015 during TB-HIV integration. Trends in TB treatment outcomes and TB-associated deaths were analyzed using respectively the χ² trend test and Kaplan-Meier methods. RESULTS The analysis involved 1318 cases: most patients were female (>50%); the median age ranged from 34 to 36 years, and >60% were late presenters (CD4 count <200 cells/µl), with a median CD4 cell count of 100-146 cells/µl at TB diagnosis. TB treatment success (cured or treatment completed) was 67-76%. Loss to follow-up (LTFU) declined systematically from 7% in 2010 to 3.4% in 2015 (P < 0.01). Antiretroviral therapy (ART) initiation during the intensive phase improved from 47% in 2009 to 97% in 2015 (P < 0.01). The mortality rate was >15% over time, and the probability of death at month 2 of anti-tuberculosis treatment was 52% higher among late presenters than in early presenters (13% vs. 6%, P < 0.01). CONCLUSION Significant LTFU improvement and prompt ART initiation could be due to well-implemented TB-HIV integration care; however, static TB-associated deaths may be due to late presentation. .


Subject(s)
Anti-HIV Agents/administration & dosage , Antitubercular Agents/administration & dosage , HIV Infections/drug therapy , Tuberculosis/drug therapy , Adult , CD4 Lymphocyte Count , Coinfection , Delivery of Health Care, Integrated/organization & administration , Female , HIV Infections/epidemiology , HIV Infections/mortality , Humans , Lost to Follow-Up , Male , Retrospective Studies , Treatment Outcome , Tuberculosis/epidemiology , Tuberculosis/mortality , Uganda
3.
Int J Tuberc Lung Dis ; 22(12): 1475-1480, 2018 12 01.
Article in English | MEDLINE | ID: mdl-30606320

ABSTRACT

BACKGROUND: Delayed diagnosis and treatment initiation of smear-negative tuberculosis (TB) patients can lead to increased morbidity and mortality, particularly among those co-infected with the human immunodeficiency virus (HIV). OBJECTIVE: To compare TB treatment initiation among smear-negative presumptive TB patients in the 6 months before and after the introduction of Xpert® MTB/RIF testing at five rural tertiary hospitals in Uganda. METHODS: Patient records of the dates and results of sputum analysis were extracted from TB laboratory registers and linked to those on treatment initiation as indicated in the TB treatment registers. The proportion of smear-negative presumptive patients who initiated anti-tuberculosis treatment was compared before and after Xpert implementation using χ² tests. Time to treatment was analysed using Kaplan-Meier survival analysis. RESULTS: Records from 3658 patients were analysed, 1894 before and 1764 after the introduction of Xpert testing. After the introduction of Xpert, 25% (437/1764) of smear-negative presumptive TB patients underwent testing. The proportion initiated on anti-tuberculosis treatment increased from 5.9% (112/1894) to 10.8% (190/1764) (P < 0.01). However, 37% (32/87) of patients with a confirmed TB diagnosis did not initiate treatment. Time to TB treatment initiation improved from 8 to 3.5 days between the study periods. CONCLUSION: Xpert testing was associated with improved TB treatment initiation among smear-negative presumptive TB patients. Improved utilisation and linkage to treatment could improve the impact of this test on patient-centred outcomes.


Subject(s)
Antibiotics, Antitubercular/therapeutic use , HIV Infections/complications , Molecular Diagnostic Techniques/statistics & numerical data , Rifampin/therapeutic use , Tuberculosis, Multidrug-Resistant/diagnosis , Adolescent , Adult , Coinfection/mortality , Female , HIV Infections/mortality , Humans , Male , Microbial Sensitivity Tests , Middle Aged , Mycobacterium tuberculosis/genetics , Sputum/microbiology , Survival Analysis , Tuberculosis, Multidrug-Resistant/mortality , Uganda/epidemiology , Young Adult
4.
J Antimicrob Chemother ; 72(4): 1172-1177, 2017 04 01.
Article in English | MEDLINE | ID: mdl-28108678

ABSTRACT

Background: Toxicities due to anti-TB treatment frequently occur among TB/HIV-coinfected patients. Objectives: To determine the association between anti-TB drug concentrations and the occurrence of hepatotoxicity and peripheral neuropathy among TB/HIV-coinfected patients. Methods: TB/HIV-coinfected patients were started on standard dose anti-TB treatment according to WHO guidelines. Anti-TB drug concentrations were measured using HPLC 1, 2 and 4 h after drug intake at 2, 8 and 24 weeks following initiation of TB treatment. Participants were assessed for hepatotoxicity using Division of AIDS toxicity tables and for peripheral neuropathy using clinical assessment of tendon reflexes, vibration sensation or symptoms. Cox regression was used to determine the association between toxicities and drug concentrations. Results: Of the 268 patients enrolled, 58% were male with a median age of 34 years. Participants with no hepatotoxicity or mild, moderate and severe hepatotoxicity had a median C max of 6.57 (IQR 4.83-9.41) µg/mL, 7.39 (IQR 5.10-10.20) µg/mL, 7.00 (IQR 6.05-10.95) µg/mL and 3.86 (IQR 2.81-14.24) µg/mL, respectively. There was no difference in the median C max of rifampicin among those who had hepatotoxicity and those who did not ( P = 0.322). There was no difference in the isoniazid median C max among those who had peripheral neuropathy 2.34 (1.52-3.23) µg/mL and those who did not 2.21 (1.45-3.11) µg/mL ( P = 0.49). Conclusions: There was no association between rifampicin concentrations and hepatotoxicity or isoniazid concentrations and peripheral neuropathy among TB/HIV-coinfected patients.


Subject(s)
Antitubercular Agents/adverse effects , Antitubercular Agents/blood , Coinfection/microbiology , Coinfection/virology , Tuberculosis/drug therapy , Adult , Antitubercular Agents/therapeutic use , Chemical and Drug Induced Liver Injury/epidemiology , Chemical and Drug Induced Liver Injury/etiology , Coinfection/drug therapy , Coinfection/epidemiology , Female , HIV Infections/complications , HIV Infections/epidemiology , Humans , Isoniazid/administration & dosage , Isoniazid/adverse effects , Isoniazid/therapeutic use , Male , Middle Aged , Peripheral Nervous System Diseases/epidemiology , Peripheral Nervous System Diseases/etiology , Prospective Studies , Regression Analysis , Rifampin/adverse effects , Rifampin/blood , Rifampin/therapeutic use , Tuberculosis/complications , Tuberculosis/epidemiology , Tuberculosis/microbiology , Tuberculosis, Pulmonary/drug therapy , Young Adult
5.
J Behav Med ; 39(3): 453-64, 2016 06.
Article in English | MEDLINE | ID: mdl-26733010

ABSTRACT

Perceived social standing (PSS) was evaluated as a determinant of differences in health outcomes among Ugandan HIV-infected adults from Kampala using cross-sectional study design. PSS was defined using the MacArthur scale of subjective social status translated and adapted for the study setting. Socio-demographic and psychosocial correlates of PSS ranking at enrollment were determined using linear regression models. High versus low PSS was defined based on the median PSS score and evaluated as a determinant of body mass index, hemoglobin, quality of life (QOL) and frailty-related phenotype via linear regression. A log-binomial regression model estimated the relative-risk of good, very good or excellent versus fair or poor self-rated health (SRH) in relation to PSS. Older age, increasing social support and material wealth were correlated with high PSS ranking, whereas female sex, experience of multiple stigmas and multiple depressive symptoms were correlated with low PSS ranking. High PSS participants were on average 1.1 kg/m(2) heavier, had 4.7 % lower frailty scores and 3.6 % higher QOL scores compared to low PSS patients (all p < 0.05); they were also more likely to self-classify as high SRH (RR 1.4, 95 % confidence interval 1.1, 1.7) but had comparable hemoglobin levels (p = 0.634). Low PSS correlated with poor physical and psychosocial wellbeing in HIV-positive Ugandan adults. The assessment of PSS as part of clinical management, combined with efforts to reduce stigma and improve social support, may identify and possibly reduce PSS-associated health inequality in Ugandan adults with HIV.


Subject(s)
Antiretroviral Therapy, Highly Active , Depression/psychology , HIV Infections/psychology , Health Status Disparities , Social Class , Social Stigma , Social Support , Adult , Cross-Sectional Studies , Female , HIV Infections/drug therapy , Humans , Male , Middle Aged , Uganda
6.
Int J STD AIDS ; 25(2): 105-12, 2014 Feb.
Article in English | MEDLINE | ID: mdl-23970633

ABSTRACT

A Pharmacy-only Refill Programme (PRP) a type of task shifting in which stable HIV-positive patients are managed through pharmacy-only visits instead of physician visits. We performed a study to identify factors for being removed from the PRP in order to establish better referral criteria. The study was performed at the Infectious Disease Clinic (IDC) in Kampala, Uganda. We selected a random sample of 588 patients from 2431 patients on antiretroviral therapy referred to the PRP at least 12 months before commencement of the PRP evaluation. We compared the characteristics of patients who during 12 months of follow-up were removed from the PRP with those who continued to be followed up. Data were abstracted from the IDC data base, the pharmacy register and the patient clinical notes. Of 588 patients, 106 (18%) were removed from the PRP. In multivariate analysis, less than 100% self-reported adherence to antiretroviral therapy, missing at least one scheduled appointment in the six months before referral to the PRP and being on a lopinavir/ritonavir-containing regimen were independently associated with being removed from the PRP. Criteria for referring patients to a PRP should focus on antiretroviral therapy adherence and appointment keeping. Patients on a lopinavir/ritonavir-containing regimen should not be targeted for a PRP. On the other hand a PRP is an efficient strategy that targets stable adherent patients in clinics with high patient load.


Subject(s)
Anti-HIV Agents/therapeutic use , HIV Infections/drug therapy , Patient Care Team/organization & administration , Patient Compliance/statistics & numerical data , Referral and Consultation/organization & administration , Adult , Ambulatory Care Facilities , Antiretroviral Therapy, Highly Active , Appointments and Schedules , CD4 Lymphocyte Count , Case-Control Studies , Female , Follow-Up Studies , HIV Infections/virology , Health Resources/organization & administration , Humans , Male , Middle Aged , Multivariate Analysis , Pharmacy , Risk Factors , Uganda , Urban Population , Viral Load
7.
Int J Tuberc Lung Dis ; 17(4): 552-8, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23485389

ABSTRACT

SETTING: In-patient hospitals in South Africa and Uganda. OBJECTIVE: To evaluate the cost-effectiveness of a lateral-flow urine lipoarabinomannan (LAM) test when added to existing strategies for tuberculosis (TB) diagnosis in human immunodeficiency virus infected adults (CD4(+) T-cell counts < 100 cells/l) with symptoms of active TB. DESIGN: Decision-analytic cost-utility model, with the primary outcome being the incremental cost-effectiveness ratio, expressed in 2010 US dollars per disability-adjusted life year (DALY) averted from the perspective of a public sector TB control program. RESULTS AND CONCLUSION: For every 1000 patients tested, adding lateral-flow urine LAM generated 80 incremental appropriate anti-tuberculosis treatments and averted 224 DALYs. Estimated cost utility was US$353 per DALY averted (95% uncertainty range $192$1161) in South Africa and $86 per DALY averted (95% uncertainty range $49$239) in Uganda, reflecting the lower treatment costs in Uganda. Cost utility was most sensitive to assay specificity, cost of anti-tuberculosis treatment, life expectancy after TB cure and cohort TB prevalence, but did not rise above $1500 per DALY averted in South Africa under any one-way sensitivity analysis. The probability of acceptability was >99.8% at a per-DALY willingness-to-pay threshold equal to the per capita gross domestic product in South Africa ($7275) and Uganda ($509).


Subject(s)
Coinfection , Developing Countries/economics , HIV Infections/diagnosis , Health Care Costs , Lipopolysaccharides/urine , Tuberculosis/diagnosis , Adult , Biomarkers/urine , CD4 Lymphocyte Count , Cost-Benefit Analysis , Decision Support Techniques , HIV Infections/economics , HIV Infections/epidemiology , Health Care Surveys , Humans , Models, Economic , Monte Carlo Method , Multivariate Analysis , Predictive Value of Tests , Prevalence , Prognosis , South Africa/epidemiology , Tuberculosis/economics , Tuberculosis/epidemiology , Tuberculosis/urine , Uganda/epidemiology , Urinalysis/economics , Young Adult
8.
Int J Tuberc Lung Dis ; 17(3): 336-41, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23407223

ABSTRACT

SETTING: A human immunodeficiency virus (HIV) clinic in a setting of high tuberculosis (TB) and HIV prevalence. OBJECTIVE: To study the incidence of and factors associated with tuberculin skin test (TST) conversion in HIV patients on antiretroviral therapy (ART). DESIGN: Prospective cohort study of TST-negative, ART-naïve HIV patients (CD4 cell count < 250 cells/l) without active TB. TST was repeated at 2 months and, if negative, at 6 months. TST positivity was defined as an induration of ≥5 mm. Clinical examination, chest X-ray and CD4 cell counts were performed at baseline and follow-up. Proportions and incidence of TST conversion were calculated, and logistic regression analyses were performed. RESULTS: Of the 142 patients, 105 (75.5%) were females. The mean age was 35.9 years (standard deviation 8.1) and the median CD4 cell count was 119 cells/l (interquartile range 42168). The incidence of TST conversion was 30.2/100 person years (95%CI 19.546.8). Conversion was not associated with clinical, CD4 cell count or chest radiography findings. CONCLUSIONS: A high incidence of TST conversion was observed, supporting the World Health Organization recommendation to provide isoniazid preventive therapy (IPT) to all HIV patients in high TB prevalence settings. If case-control programmes choose to provide IPT only to TST-positive patients, repeat TST should be considered following initiation of ART.


Subject(s)
Anti-Retroviral Agents/therapeutic use , Coinfection , HIV Infections/drug therapy , Tuberculin Test , Tuberculosis/diagnosis , Adult , CD4 Lymphocyte Count , Female , HIV Infections/diagnosis , HIV Infections/epidemiology , Humans , Incidence , Logistic Models , Male , Middle Aged , Predictive Value of Tests , Prevalence , Prospective Studies , Radiography, Thoracic , Time Factors , Tuberculosis/epidemiology , Uganda/epidemiology
10.
HIV Med ; 13(6): 337-44, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22296211

ABSTRACT

OBJECTIVES: High early mortality after antiretroviral therapy (ART) initiation in resource-limited settings is associated with low baseline CD4 cell counts and a high burden of opportunistic infections. Our large urban HIV clinic in Uganda has made concerted efforts to initiate ART at higher CD4 cell counts and to improve diagnosis and care of patients coinfected with tuberculosis (TB). We sought to determine associated treatment outcomes. METHODS: Routinely collected data for all patients who initiated ART from 2005 to 2009 were analysed. Median baseline CD4 cell counts by year of ART initiation were compared using the Cuzick test for trend. Mortality and TB incidence rates in the first year of ART were computed. Hazard ratios (HRs) were calculated using multivariable Cox proportional hazards models. RESULTS: First-line ART was initiated in 7659 patients; 64% were women, and the mean age was 37 years (standard deviation 9 years). Median baseline CD4 counts increased from 2005 to 2009 [82 cells/µL (interquartile range (IQR) 24, 153) to 148 cells/µL (IQR 61, 197), respectively; P<0.001]. The mortality rate fell from 6.5/100 person-years at risk (PYAR) [95% confidence interval (CI) 5.5-7.6 PYAR] to 3.6/100 PYAR (95% CI 2.2-5.8 PYAR). TB incidence rates increased from 8.2/100 PYAR (95% CI 7.1-9.5 PYAR) to 15.6/100 PYAR (95% CI 12.4-19.7 PYAR). A later year of ART initiation was independently associated with decreased mortality (HR 0.91; 95% CI 0.83-1.00; P=0.04). CONCLUSIONS: Baseline CD4 cell counts have increased over time and are associated with decreased mortality. Additional reductions in mortality might be a result of a better standard of care and increased TB case finding. Further efforts to initiate ART earlier should be prioritized even in a setting of capped or reduced funding for ART programmes.


Subject(s)
AIDS-Related Opportunistic Infections/epidemiology , Acquired Immunodeficiency Syndrome/drug therapy , Acquired Immunodeficiency Syndrome/epidemiology , Anti-HIV Agents/therapeutic use , Tuberculosis/epidemiology , AIDS-Related Opportunistic Infections/drug therapy , AIDS-Related Opportunistic Infections/immunology , Acquired Immunodeficiency Syndrome/immunology , Adult , CD4 Lymphocyte Count , Cohort Studies , Female , Humans , Incidence , Male , Retrospective Studies , Tuberculosis/drug therapy , Tuberculosis/immunology , Uganda/epidemiology , Urban Population/statistics & numerical data
11.
HIV Med ; 11(5): 289-98, 2010 May.
Article in English | MEDLINE | ID: mdl-20002778

ABSTRACT

OBJECTIVES: While highly active antiretroviral therapy (HAART) decreases long-term morbidity and mortality, its short-term effect on hospitalization rates is unknown. The primary objective of this study was to determine hospitalization rates over time in the year after HAART initiation for virological responders and nonresponders. METHODS: Hospitalizations among 1327 HAART-naïve subjects in an urban HIV clinic in 1997-2007 were examined before and after HAART initiation. Hospitalization rates were stratified by virological responders (> or =1 log(10) decrease in HIV-1 RNA within 6 months after HAART initiation) and nonresponders. Causes were determined through International Classification of Diseases, 9th Revision (ICD-9) codes and chart review. Multivariate negative binomial regression was used to assess factors associated with hospitalization. RESULTS: During the first 45 days after HAART initiation, the hospitalization rate of responders was similar to their pre-HAART baseline rate [75.1 vs. 78.8/100 person-years (PY)] and to the hospitalization rate of nonresponders during the first 45 days (79.4/100 PY). The hospitalization rate of responders fell significantly between 45 and 90 days after HAART initiation and reached a plateau at approximately 45/100 PY from 91 to 365 days after HAART initiation. Significant decreases were seen in hospitalizations for opportunistic and nonopportunistic infections. CONCLUSIONS: The first substantial clinical benefit from HAART may be realized by 90 days after HAART initiation; providers should keep close vigilance at least until this time.


Subject(s)
Antiretroviral Therapy, Highly Active , HIV Infections/drug therapy , Hospitalization/statistics & numerical data , Outcome Assessment, Health Care , Urban Health Services/statistics & numerical data , Adolescent , Adult , CD4 Lymphocyte Count , Female , HIV Infections/immunology , HIV Infections/virology , Humans , Immune Reconstitution Inflammatory Syndrome/epidemiology , Male , Middle Aged , Multivariate Analysis , RNA, Viral/blood , Time Factors , Young Adult
12.
Nat Med ; 6(12): 1327-9, 2000 Dec.
Article in English | MEDLINE | ID: mdl-11100115

ABSTRACT

Mycobacterium tuberculosis is a globally successful pathogen due to its ability to persist for long periods of time unrecognized by the human immune system. The panoply of genes that allows the organism to enter latency and then re-emerge later during endogenous reinfection are now being elucidated. Novel antimicrobials and vaccines will need to target these mycobacterial pathogenic mechanisms to suceed against tuberculosis.


Subject(s)
Mycobacterium tuberculosis/pathogenicity , Tuberculosis, Pulmonary/immunology , Acquired Immunodeficiency Syndrome/complications , Adaptation, Biological , Animals , Humans , Mice , Models, Biological , Tuberculosis, Pulmonary/complications
13.
Int J Tuberc Lung Dis ; 4(2 Suppl 1): S18-23, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10688144

ABSTRACT

A major milestone in tuberculosis research occurred in June 1998 with the report of the genomic sequence of Mycobacterium tuberculosis H37Rv. The complete determination of the 4411529 base pairs of the M. tuberculosis genome opens avenues for new scientific opportunities in basic science and clinical research on tuberculosis. In this paper we will review the findings presented by the complete genome and discuss the impact that this sequence will have on the areas of comparative genomics, bacterial pathogenesis, and diagnostics development for tuberculosis. Indirect benefits of the complete genome sequence are anticipated in the areas of drug development and vaccine development as future discoveries in bacterial pathogenesis and immunology accrue.


Subject(s)
Genome, Bacterial , Mycobacterium tuberculosis/genetics , DNA, Bacterial/analysis , Humans , Sequence Analysis, DNA
14.
J Bacteriol ; 181(24): 7629-33, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10601225

ABSTRACT

A chemically inducible acetamidase promoter-sigF fusion gene was integrated into the chromosome of Mycobacterium bovis BCG. Two-dimensional protein gel analysis permitted the identification of a number of protein spots whose expression was SigF related. One spot upregulated by inappropriate induction of sigF expression corresponded to the 16-kDa antigen alpha-crystallin.


Subject(s)
Amidohydrolases/genetics , Antigens, Bacterial/biosynthesis , Bacterial Proteins/genetics , Gene Expression Regulation, Bacterial , Mycobacterium tuberculosis/genetics , Sigma Factor/biosynthesis , Sigma Factor/genetics , Antigens, Bacterial/genetics , Chromosomes, Bacterial , Electrophoresis, Gel, Two-Dimensional , Enzyme Induction/genetics , Up-Regulation
15.
Proc Natl Acad Sci U S A ; 96(22): 12844-8, 1999 Oct 26.
Article in English | MEDLINE | ID: mdl-10536010

ABSTRACT

Iron is an essential nutrient for the survival of most organisms and has played a central role in the virulence of many infectious disease pathogens. Mycobacterial IdeR is an iron-dependent repressor that shows 80% identity in the functional domains with its corynebacterial homologue, DtxR (diphtheria toxin repressor). We have transformed Mycobacterium tuberculosis with a vector expressing an iron-independent, positive dominant, corynebacterial dtxR hyperrepressor, DtxR(E175K). Western blots of whole-cell lysates of M. tuberculosis expressing the dtxR(E175K) gene revealed the stable expression of the mutant protein in mycobacteria. BALB/c mice were infected by tail vein injection with 2 x 10(5) organisms of wild type or M. tuberculosis transformed with the dtxR mutant. At 16 weeks, there was a 1.2 log reduction in bacterial survivors in both spleen (P = 0.0002) and lungs (P = 0.006) with M. tuberculosis DtxR(E175K). A phenotypic difference in colonial morphology between the two strains also was noted. A computerized search of the M. tuberculosis genome for the palindromic consensus sequence to which DtxR and IdeR bind revealed six putative "iron boxes" within 200 bp of an ORF. Using a gel-shift assay we showed that purified DtxR binds to the operator region of five of these boxes. Attenuation of M. tuberculosis can be achieved by the insertion of a plasmid containing a constitutively active, iron-insensitive repressor, DtxR(E175K), which is a homologue of IdeR. Our results strongly suggest that IdeR controls genes essential for virulence in M. tuberculosis.


Subject(s)
Bacterial Proteins/genetics , DNA-Binding Proteins/genetics , Iron/metabolism , Mycobacterium tuberculosis/pathogenicity , Repressor Proteins/genetics , Virulence/genetics , Animals , Base Sequence , Cloning, Molecular , Corynebacterium/genetics , DNA, Bacterial , Mice , Mice, Inbred BALB C , Molecular Sequence Data , Mycobacterium tuberculosis/genetics , Sequence Homology, Nucleic Acid
16.
Clin Infect Dis ; 27(3): 536-42, 1998 Sep.
Article in English | MEDLINE | ID: mdl-9770154

ABSTRACT

Although 10%-15% of patients with AIDS in the United States may acquire cryptosporidium infection, little data exist on clinical or histological characteristics that differentiate clinical outcomes. A case-control study of 83 HIV-positive adult patients with cryptosporidiosis was conducted, as was a histopathologic review of data on gastrointestinal biopsy specimens from 30 patients. Four clinical syndromes were identified: chronic diarrhea (36% of patients), choleralike disease (33%), transient diarrhea (15%), and relapsing illness (15%). A multivariate analysis of data for cases and controls revealed that acquiring cryptosporidiosis was associated with the presence of candidal esophagitis (odds ratio [OR], 2.53; P < .002) and Caucasian race (OR, 6.71; P = .0001) but not with sexual orientation. Cases had a significantly shorter duration of survival from the time of diagnosis than did controls (240 vs. 666 days, respectively; P = .0004), which was independent of sex, race, or or injection drug use. Antiretroviral use was protective against disease (OR, 0.072; P = .0001). All four clinical syndromes were represented among the histological data. There was no statistically significant correlation between histological intensity of infection and clinical severity of illness.


Subject(s)
AIDS-Related Opportunistic Infections/mortality , Cryptosporidiosis/mortality , AIDS-Related Opportunistic Infections/parasitology , AIDS-Related Opportunistic Infections/pathology , Adult , Aged , Animals , Case-Control Studies , Cohort Studies , Cryptosporidiosis/complications , Cryptosporidiosis/parasitology , Cryptosporidiosis/pathology , Cryptosporidium/isolation & purification , Disease Progression , Female , Humans , Logistic Models , Male , Middle Aged , Survival Analysis
17.
AIDS ; 12(18): 2459-66, 1998 Dec 24.
Article in English | MEDLINE | ID: mdl-9875584

ABSTRACT

OBJECTIVE: To characterize the histology of AIDS-associated cryptosporidiosis and identify features that explain the clinical variability. DESIGN: A retrospective analysis of HIV-positive individuals with cryptosporidiosis who underwent endoscopy at the Johns Hopkins Hospital between 1985 and 1996. METHODS: The histologic features (intensity of Cryptosporidium infection, inflammation, mucosal damage, copathogens) of gastrointestinal biopsies from 37 HIV-positive individuals with cryptosporidiosis were systematically graded. These histologic features were correlated with the severity of the diarrheal illness obtained from a patient chart review. RESULTS: Histologic features associated with Cryptosporidium infection include a neutrophilic infiltrate in the stomach, villus blunting in the duodenum, cryptitis and epithelial apoptosis in the colon, and reactive epithelial changes in the stomach and duodenum. The nature and intensity of the inflammatory response varied widely; however, duodenal biopsies from a subset of patients (37%) revealed marked acute inflammation that was associated with concomitant cytomegalovirus infection. Although duodenal infection was common (93% of individuals), infection of other sites was variable (gastric cryptosporidiosis in 40% and colonic cryptosporidiosis in 74%). Widespread infection of the intestinal tract, which included both the large and small intestine, was associated with the most severe diarrheal illness. CONCLUSIONS: Cryptosporidium infection produces histologic evidence of gastrointestinal mucosal injury. The inflammatory response to the infection is variable, and may be modified by copathogens such as cytomegalovirus. The clinical manifestations are influenced, in part, by the anatomic distribution of the infection, with extensive infections involving both small and large intestines producing the most severe illness.


Subject(s)
AIDS-Related Opportunistic Infections/pathology , Cryptosporidiosis/pathology , Cryptosporidium/isolation & purification , Adolescent , Adult , Aged , Animals , Child , Child, Preschool , Colon/parasitology , Colon/pathology , Cryptosporidiosis/complications , Cytomegalovirus Infections/complications , Diarrhea/parasitology , Diarrhea/pathology , Duodenum/parasitology , Duodenum/pathology , Endoscopy , Female , Humans , Male , Middle Aged , Retrospective Studies , Stomach/parasitology , Stomach/pathology
18.
Ann Intern Med ; 123(11): 835-40, 1995 Dec 01.
Article in English | MEDLINE | ID: mdl-7486465

ABSTRACT

OBJECTIVE: To define clinical and laboratory variables that suggest the presence of Clostridium difficile colitis and to establish the number of stool specimens needed to reasonably exclude the diagnosis of C. difficile colitis. DESIGN: Prospective study of consecutive inpatients whose stool specimens were sent to be evaluated for the presence of C. difficile toxin. SETTING: University teaching hospital. PATIENTS: 268 hospital inpatients in medical, surgical, and gynecology units. MEASUREMENTS: Structured history and physical examination; detection of C. difficile toxin by cytotoxin tissue-culture assay with anti-C. difficile antiserum neutralization and by enzyme-linked immunoassay (EIA) for C. difficile toxins A and B; and detection of fecal leukocytes by microscopic examination and by latex agglutination lactoferrin assay. RESULTS: 43 of 268 consecutive inpatients were positive for C. difficile toxin by EIA or tissue-culture assay. Although toxin was detected by EIA alone in 39 of the 43 patients, it was detected in an additional 4 patients (10%) by tissue-culture assay alone. Univariate and multivariate logistic regression analysis showed that the following clinical and laboratory features were associated with C. difficile toxin positivity: the onset of diarrhea 6 or more days after the administration of antibiotics (odds ratio, 1.38 [95% CI, 1.10 to 3.79]); hospital stay longer than 15 days (odds ratio, 1.33 [CI, 1.09 to 3.95]); the presence of fecal leukocytes determined by microscopy (odds ratio, 2.39 [CI, 1.05 to 5.42]) or lactoferrin assay (odds ratio, 3.74 [CI, 1.80 to 7.76]); the presence of semiformed (as opposed to watery) stools (odds ratio, 2.33 [CI, 1.10 to 4.90]); and cephalosporin use (odds ratio, 2.36 [CI, 1.10 to 5.09]). Toxin-positive patients were no more likely than controls to have had fever, abdominal pain or cramps, leukocytosis, green-colored diarrhea, or blood in the stool or to have received clindamycin or penicillin derivatives. Of the 43 patients with C. difficile toxin, 34 (79%) had positive results for the toxin on the first stool specimen, 5 (cumulative, 91%) had positive results on the second specimen, and 4 had positive results on the third specimen. Overall, the negative predictive value of the first stool specimen was 97%. All patients who had two or more clinical or laboratory predictors were diagnosed with C. difficile disease when either the first or the second stool specimen was positive for toxin. CONCLUSIONS: Clinicians at the bedside can use readily available clinical and laboratory information to decide which patients are likely to have C. difficile disease and when it is appropriate and useful to order specific diagnostic tests for C. difficile toxin. Such data are also useful in determining the number of stool samples that reasonably excludes the diagnosis of C. difficile colitis.


Subject(s)
Clostridioides difficile/isolation & purification , Clostridium Infections/diagnosis , Colitis/diagnosis , Aged , Analysis of Variance , Bacterial Toxins/analysis , Colitis/microbiology , Feces/microbiology , Female , Humans , Immunoassay , Immunoenzyme Techniques , Leukocyte Count , Male , Middle Aged , Odds Ratio , Prospective Studies , Regression Analysis , Sensitivity and Specificity
19.
Biochem Int ; 19(5): 969-76, 1989 Nov.
Article in English | MEDLINE | ID: mdl-2635856

ABSTRACT

We have previously described the presence of a protein containing intact, covalently bound spermidine during very early embryogenesis of the sea urchin (Strongylocentrotus purpuratus). Proteins containing other polyamine metabolites also appear as embryogenesis proceeds. These proteins which contain label derived from exogenous radioactive spermidine show a characteristic pattern which changes during the course of embryonic development. We document for the first time that hypusine, the polyamine metabolite which is a characteristic component of the eukaryotic protein translation initiation factor eIF-4D, is present in more than one species of macromolecule. In addition, N1-acetylspermidine has also been identified as a significant intracellular metabolite of spermidine during embryogenesis.


Subject(s)
Sea Urchins/embryology , Spermidine/metabolism , Animals , Chromatography, High Pressure Liquid , Male , Spermidine/analogs & derivatives
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