Unveiling the hidden threat of carbapenemase-producing Enterobacteriaceae in hospital water environments: A single-center study.

This retrospective study examined the presence of carbapenemase-producing Enterobacteriaceae in hospital water environments. Results showed that carbapenemase-producing Enterobacteriaceae was detected in 41.5% of the samples within 1 m of a water source (showers or sinks), with 20.6% of the positive samples associated with shower water sources.

A Multi-Laboratory Evaluation of Commercial Monkeypox Virus Molecular Tests.

In this report, we describe the first national scale multi-laboratory evaluation of monkeypox virus (MPXV) DNA commercial PCR kits. The objective of this study was to evaluate 2 kits by different diagnostic laboratories across Israel. Ten standardized samples were tested simultaneously using the Novaplex (15 laboratories) and Bio-Speedy (seven laboratories) kits. An in-house assay based on previously published reactions was used as reference. Comparison of the results showed high intra-assay agreement between laboratories, with small variations for most samples. The in-house assay had an analytical detection limit of less than 10 copies per reaction. While the 2 commercial kits were able to detect specimens with low viral loads similarly to the in-house assay, significant differences were observed, in the Cq values and relative fluorescence (RF), between the assays. The RF signal of the in-house and Bio-Speedy assays ranged between 5,000 and 10,000 RFU, while the signal in the Novaplex assay was less than 600 RFU. Due to the kit measurement protocol, the Cq values of the Bio-Speedy kit were 5 to 7.5 cycles lower than those of the in-house assay. On the contrary, the Cq values of the Novaplex kit were significantly higher than those of the in-house assay, with differences of 3 to 5 cycles per sample. Our results suggest that while all assays were similar in their overall sensitivity, direct comparison of Cq values between them may be misleading. To our knowledge, this is the first methodical evaluation of commercial MPX test kits. We therefore anticipate that this study would help diagnostic laboratories in choosing a specific MPX detection assay. IMPORTANCE To the best of our knowledge, this study is the first methodical evaluation of commercial kits designed for Monkeypox virus detection. This was done by performing the same tests using the same sample set in multiple laboratories, simultaneously, on a national scale. It therefore provides important and unique information on the performance of such kits and provides a guideline for choosing the assay of choice for monkeypox virus diagnosis in a standard diagnostic laboratory. It also demonstrates potential complications when trying to compare the results of different assays, even when testing exactly the same samples, under identical conditions.

Development of Autoantibodies Following BNT162b2 mRNA COVID-19 Vaccination and Their Association with Disease Flares in Adult Patients with Autoimmune Inflammatory Rheumatic Diseases (AIIRD) and the General Population: Results of 1-Year Prospective Follow-Up Study.

Development of autoantibodies following BNT162b2 mRNA COVID-19 vaccination and their association with disease flares in adult patients with autoimmune inflammatory rheumatic diseases (AIIRD) and the general population: results of 1-year prospective follow-up study. We conducted a prospective study aimed at investigating the incidence of appearance of autoantibodies (antinuclear, antiphospholipid, and rheumatoid factor) in the sera of 463 adult patients with AIIRD compared to 55 controls from the general population prior to, and following the second and third vaccine doses, and at 1-year of follow-up. Pre- and post-vaccination disease activity indices and the association of autoantibodies with rheumatic disease flares and new onset AIIRD were examined. Autoantibody development of any type in AIIRD patients vs. the controls was 4.0% (vs. 6.7%, p = 0.423) following two vaccine doses and 7.6% (vs. 0%, p = 0.152) after three doses. There was no significant difference in sex, age, or disease-type among individuals with and without autoantibody development, regardless of the immunosuppressant use. More patients developed autoantibodies following the third than the second vaccine dose (p = 0.004). Disease flares occurred in 5.8% and 7.2% of AIIRD patients following second and third vaccine doses, respectively, with autoantibody production increasing the risk of flares following the second (p = 0.002) and third (p = 0.004) vaccine doses. BNT162b2 vaccination resulted in the development of autoantibodies in a minority of AIIRD patients and controls. Autoantibody development was associated with disease flares in patients, but no new-onset autoimmunity was observed.

Maternal and Neonatal Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Immunoglobulin G Levels After the Pfizer-BioNTech Booster Dose for Coronavirus Disease 2019 (COVID-19) Vaccination During the Second Trimester of Pregnancy.

OBJECTIVE: To evaluate maternal and neonatal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin G (IgG) antibody levels at birth after a third (booster) dose of the Pfizer-BioNTech messenger RNA (Pfizer) coronavirus disease 2019 (COVID-19) vaccine during the second trimester of pregnancy, and compare them with those in women who received two vaccine doses during the second trimester. METHODS: We conducted a prospective cohort study of women admitted to the delivery ward at a single center who received the third Pfizer COVID-19 vaccine dose (booster group) at 17-30 weeks of pregnancy and who did not have previous SARS-CoV-2 infection. Maternal and neonatal antibody levels were measured on admission for delivery and in the umbilical cord blood after birth. Antibody levels for the booster group were compared with those in a historical control group of pregnant women who received their second vaccine dose (two-dose group) within the same gestational age window. RESULTS: Between October 2021 and February 2022, antibody levels were measured in 121 women and 109 neonates at a mean±SD of 15.3±3.9 weeks after booster vaccination. Neonatal titers measured two times higher than maternal titers, with inverse correlation between maternal and neonatal titers at birth and time interval from third vaccination. The two-dose group included 121 women and 107 neonates, with antibody levels measured at a mean±SD of 14.6±2.6 weeks after the second dose. Median [interquartile range] maternal antibody titers were higher in the booster group (4,485 [2,569-9,702] AU/mL) compared with the two-dose group (1,122 [735-1,872] AU/mL) (P<.001). Furthermore, neonatal antibody titers were higher in the booster group (8,773 [5,143-18,830] AU/mL) compared with the two-dose group (3,280 [2,087-5,754] AU/mL) (P<.001). CONCLUSION: Maternal and neonatal SARS-CoV-2 IgG antibody titers after second-trimester maternal Pfizer COVID-19 vaccination were significantly higher after the booster dose compared with the two-dose vaccination series. Although there is uncertainty as to whether antibody levels correlate with protection, these data support the importance of booster vaccination during pregnancy to restore maternal and neonatal protection against COVID-19.

Third trimester messenger RNA COVID-19 booster vaccination upsurge maternal and neonatal SARS-CoV-2 immunoglobulin G antibody levels at birth.

OBJECTIVE: BNT162b2 messenger RNA (mRNA) COVID-19 vaccine administered during pregnancy was found to produce a strong maternal immunoglobulin (IgG) response which crosses the placenta to the newborn. Our aim was to evaluate maternal and neonatal SARS-CoV-2 IgG antibody levels at birth, following a COVID-19 booster vaccine during the third trimester. STUDY DESIGN: A prospective cohort study including women admitted to delivery ward at least 7 days after their BNT162b2 (Pfizer/BioNTech) booster vaccination without a prior clinical COVID-19 infection. SARS-CoV-2 IgG antibodies levels were measured in maternal blood upon admission to delivery and in the umbilical blood within 30 min following delivery. The correlation between antibody titers, feto-maternal characteristics, maternal side effects following vaccination, and time interval from vaccination to delivery were analyzed. RESULTS: Between September to November 2021, high antibody levels were measured in all 102 women and 93 neonatal blood samples, at a mean ± standard deviation duration of 7.0 ± 2.9 weeks after the third vaccine. We found positive correlation between maternal and neonatal antibodies (r = 0.73, 95% confidence interval [CI] 0.61 to 0.81, p < 0.001), with neonatal titers approximately 1.4 times higher compared to maternal titers. In the multivariable analysis maternal antibody levels dropped by -7.2% (95% CI -12.0 to -2.3%, p = 0.005) for each week that passed since the receipt of the third vaccine dose. In contrary, systemic side effects after the third vaccine were associated with higher maternal antibody levels of 52.0% (95% CI 4.7 to 120.8%, p = 0.028). Also, for each 1 unit increase in maternal body mass index, maternal antibody levels increased by 3.6% (95% CI 0.4 to 6.9%, p = 0.025). CONCLUSIONS: BNT162b2 mRNA COVID-19 booster dose during the third trimester of pregnancy was associated with strong maternal and neonatal responses as reflected by maternal and neonatal SARS-CoV-2 IgG antibody levels measured at birth. These findings support the administration of the COVID-19 booster to pregnant women to restore maternal and neonatal protection during the ongoing pandemic.

Group B Streptococcus real-time PCR may potentially reduce intrapartum maternal antibiotic treatment.

BACKGROUND: Protocols for preventing early-onset group B streptococcal (GBS) neonatal infection may result in unnecessary antibiotics administration. Real-time polymerase chain reaction (PCR) can provide a result within 30-60 min and has been found to be specific and sensitive for defining intrapartum GBS status. OBJECTIVE: To evaluate whether implementation of GBS fast real-time PCR to all women who require GBS prophylaxis may reduce the use of maternal prophylactic antibiotics. METHODS: This prospective cohort study included women admitted to a single delivery ward who required prophylactic antibiotics either due to a positive antepartum GBS culture screening performed at 35-37 weeks or due to an unknown GBS status with an intrapartum risk factor. All the women were tested by a double vaginal swab (real-time PCR and culture) as soon as it became apparent, they required antibiotic prophylaxis and prior to its administration. RESULTS: Between May 2019 and August 2020, 303 women met eligibility criteria and were enrolled, but four were excluded from the analysis due to failed culture or PCR tests. Of 299 women included in the study, 208 (69.5%) and 180 (60.2%) women, showed no evidence of GBS on intrapartum culture or PCR, respectively. Of 89 GBS antepartum carriers, 43 (48.3%) and 32 (35.9%) had negative intrapartum culture and PCR results, respectively. Of the 210 women with risk factors, 165 (78.5%) were culture negative and 148 (70.4%) had a negative PCR. Using intrapartum culture as the gold standard, intrapartum GBS real-time PCR was found to have a sensitivity of 97.8% (95% confidence interval [CI] 92.3, 99.7) and a specificity of 85.6% (95% CI 80.1, 90.1). CONCLUSIONS: Compared with antepartum universal culture screening or intrapartum risk-factor assessment, the need for maternal antibiotic treatment may be substantially reduced by implementation of intrapartum GBS real-time PCR, without compromising the sensitivity of GBS detection.

Maternal and Neonatal SARS-CoV-2 Immunoglobulin G Antibody Levels at Delivery After Receipt of the BNT162b2 Messenger RNA COVID-19 Vaccine During the Second Trimester of Pregnancy.

IMPORTANCE: BNT162b2 messenger RNA (mRNA) COVID-19 vaccination in the third trimester was found to be associated with a strong maternal humoral IgG response that crossed the placenta and approached maternal titers in the newborn. OBJECTIVE: To evaluate maternal and neonatal SARS-CoV-2 immunoglobulin G (IgG) antibody levels at birth after mRNA COVID-19 vaccination during the second trimester of pregnancy. DESIGN, SETTING, AND PARTICIPANTS: This prospective cohort study, conducted at a single medical center in Haifa, Israel, from May to July 2021, included women with a singleton pregnancy over 24 weeks of gestation at least 7 days after receipt of their second COVID-19 vaccine dose who were not known to be previously infected with COVID-19. EXPOSURES: BNT162b2 (Pfizer/BioNTech) vaccination. MAIN OUTCOMES AND MEASURES: The primary outcomes were SARS-CoV-2 IgG antibody titers measured in the parturient at admission and in the umbilical cord blood within 30 minutes after delivery. Secondary outcomes were the correlation between antibody titers, feto-maternal characteristics, maternal adverse effects after vaccination, and time interval from vaccination to delivery. RESULTS: Antibody levels were measured for 129 women (mean [SD] age, 31.9 [4.9] years) and 114 neonates, with 100% of the tests having positive results. The mean (SD) gestational age at administration of the second vaccine dose was 24.9 (3.3) weeks. Neonatal IgG titers were 2.6 times higher than maternal titers (median [range], 3315.7 [350.1-17 643.5] AU/mL vs 1185.2 [146.6-32 415.1] AU/mL). A positive correlation was demonstrated between maternal and neonatal antibodies (r = 0.92; 95% CI, 0.89-0.94). Multivariable analysis revealed that for each week that passed since receipt of the second vaccine dose, maternal and neonatal antibody levels changed by -10.9% (95% CI, -17.2% to -4.2%; P = .002) and -11.7% (95% CI, -19.0 to -3.8%; P = .005), respectively. For each 1-year increase in the mother's age, maternal and neonatal antibody levels changed by -3.1% (95% CI, -5.3% to -0.9%; P = .007) and -2.7% (95% CI, -5.2% to -0.1%; P = .04), respectively. CONCLUSIONS AND RELEVANCE: In this cohort study, receipt of the BNT162b2 mRNA COVID-19 vaccine during the second trimester of pregnancy was associated with maternal and neonatal humoral responses, as reflected in maternal and neonatal SARS-CoV-2 IgG antibody levels measured after delivery. These findings support COVID-19 vaccination of pregnant individuals during the second trimester to achieve maternal protection and newborn safety during the pandemic.

Prognosis of Human Papillomavirus-Negative Compared to Human Papillomavirus-Positive Cervical Cancer.

OBJECTIVES: The aims of the study were to evaluate the prevalence and prognosis of human papillomavirus (HPV)-negative cervical cancer (CC) and to compare these to data for HPV-positive CC. MATERIALS AND METHODS: This retrospective cohort study compared between HPV-negative CC and HPV-positive CC patients. Primary end points were disease-free survival and overall survival. Secondary end points were demographic and clinical variables including histological diagnosis, stage, and treatment. RESULTS: Of 233 women with CC, 18 (8%) tested HPV-negative. During a median follow-up of 45 months, 33 (14%) recurrences and 41 (18%) deaths were observed. Eleven of the 18 women (61%) who tested HPV-negative and 41 of the 215 (19%) who tested HPV-positive had only adenocarcinoma (p < .001). In a multivariate logistic regression analysis, advanced age (p = .003) and primary treatment with chemotherapy and/or radiotherapy (p < .001) remained statistically significant for recurrence or mortality (disease-free survival). The factors associated with lower survival were advanced age (p = .008), higher stage at diagnosis (p < .001), and HPV negativity (p = .062). Median overall survival for HPV-positive CC was not reached, compared with 24 months for HPV-negative CC. Kaplan-Meier curves showed lower rates of disease-free survival (p = .008) and overall survival (p = .011), for women with HPV-negative compared with HPV-positive CC. CONCLUSIONS: The relatively poor prognosis of HPV-negative CC is important in light of its relatively high prevalence, which could increase proportionally to HPV-positive CC due to increased HPV screening and vaccination. Further studies are needed to confirm whether HPV status is truly an independent prognostic factor in CC.

The Association Between Clearance of Human Papillomavirus After Conization for Cervical Cancer and Absence of Cancer.

OBJECTIVES: We assessed the relation between clearance of high-risk human papillomavirus (HR-HPV) after large loop excision of the transformation zone (LLETZ) and absence of residual disease, in women diagnosed with cervical cancer (CC) and adenocarcinoma in situ (AIS). MATERIALS METHODS: Data were collected from 92 women diagnosed with CC and AIS who were positive to HR-HPV and had a repeat cervical HPV test 3-12 weeks after LLETZ (in which CC/AIS were diagnosed) and before final surgical treatment. We compared characteristics of women with negative and positive HR-HPV after LLETZ. RESULTS: The HR-HPV results after the LLETZ operation were negative in 40 women and positive in 52 women. The HR-HPV-negative group included a significantly higher incidence of AIS: 14 (35%) vs 5 (9.6%, p < .006).In the negative HR-HPV post-LLETZ group, 36 (90%) had normal histology and only 2 (5%) had cancer in the final histological specimen. Among 34 women who underwent radical hysterectomy/trachelectomy after LLETZ, a normal final histology was observed in 75% and 9% of those who were HR-HPV negative and HR-HPV positive, respectively (p < .0005). The positive predictive value for absence of residual cancer, with clearance of HR-HPV after LLETZ, was 95%. CONCLUSIONS: Clearance of HR-HPV from the cervix a short time after LLETZ has a high association with the absence of residual cancer in the final outcome, either in the pathology or the follow-up. Testing for HR-HPV a short time after LLETZ might serve as a parameter for risk assessment.

Clinical characteristics and outcomes of patients with Escherichia coli in airway samples.

PURPOSES: Escherichia coli is one of the most common pathogens in nosocomial and community-acquired infections, but is an uncommon respiratory pathogen. However, this pathogen may at times be seen in respiratory secretions. The study aims to determine the clinical and prognostic value of E. coli in respiratory secretions. METHODS: Cultures of respiratory secretions from hospitalized and outpatients between 2009 and 2016 were screened for isolation of E. coli. We defined three groups of patients: "Sensitive (S)"-growth of E. coli sensitive to all antimicrobials tested; Intermediate (I)-resistant to 1-2 antimicrobial classes; and "Resistant (R)"-resistant to at least three antibiotic classes. We compared factors associated with resistant strains and outcomes between the groups. RESULTS: Eighty patients with E. coli isolates from respiratory secretions were identified while screening 177 712 (4.5: 10 000 samples). Of the E. Coli-positive cultures, 11 were from ambulatory patients, 31 patients were hospitalized and 37 were hospitalized and intubated. Ten people had bronchiectasis and 29 had COPD. Patients with resistant E. coli had significantly more hospitalization days prior to positive culture (S = 1.2 ± 1.89 days, I = 1.23 ± 1.5 days and R = 3.7 ± 5.4 days, respectively; P = 0.002). Mortality was higher in patients with a resistant strain (R) versus (I) or (S) (76.7%, 31.8% and 26.7%, respectively; P < 0.0001) and remained significantly elevated after correction for prior hospital days. CONCLUSIONS: Pulmonary infection due to E. coli is uncommon. Isolation of resistant E. coli is associated with length of previous hospitalization, elevated mortality and may be viewed as a nosocomial pathogen.

Melatonin Stability in Human Milk.

Introduction: Melatonin is an antioxidant, a circadian pacemaker, and an immune system stimulator. Studies have demonstrated beneficial effects of melatonin on various conditions in neonates. Melatonin is secreted in breast milk in circadian rhythm, but its half-life and stability in this medium and in real-life conditions of freezing and defrosting is unknown. The objective of this feasibility study was to evaluate stability of melatonin in breast milk after freezing and defrosting. Methods and Results: Breast milk samples of nocturnal milk and daytime milk were collected from 13 healthy breastfeeding mothers and were immediately frozen. Samples were defrosted in room temperature and were sampled for melatonin immediately and every hour for 4 hours and at 24 hours after defrosting. Melatonin levels were measured with Melatonin direct Saliva ELISA kit (IBL International).There was no statistically significant difference between levels at the different time points (p = 0.696). Melatonin levels in daytime milk were significantly lower than night-time levels (p = 0.028). Conclusion: Melatonin is stable in human milk for at least 4 hours after defrosting and even up to 24 hours. Further research of the therapeutic potential of night breast milk high in melatonin is needed.

Characterization of hepatitis B and delta coinfection in Israel.

BACKGROUND: Characteristics of hepatitis B (HBV) and delta (HDV) coinfection in various geographical regions, including Israel, remain unclear. Here we studied HDV seroprevalence in Israel, assessed HDV/HBV viral loads, circulating genotypes and hepatitis delta antigen (HDAg) conservation. METHODS: Serological anti HDV IgG results from 8969 HBsAg positive individuals tested in 2010-2015 were retrospectively analyzed to determine HDV seroprevalence. In a cohort of HBV/HDV coinfected (n=58) and HBV monoinfected (n=27) patients, quantitative real-time PCR (qRT-PCR) and sequencing were performed to determine viral loads, genotypes and hepatitis delta antigen (HDAg) protein sequence. RESULTS: 6.5% (587/8969) of the HBsAg positive patients were positive for anti HDV antibodies. HDV viral load was >2 log copies/ml higher than HBV viral load in most of the coinfected patients with detectable HDV RNA (86%, 50/58). HDV genotype 1 was identified in all patients, most of whom did not express HBV. While 66.6% (4/6) of the HBV/HDV co-expressing patients carried HBV-D2 only 18.5% (5/27) of the HBV monoinfections had HBV-D2 (p=0.03). Higher genetic variability in the HDAg protein sequence was associated with higher HDV viral load. CONCLUSIONS: The overall significant prevalence of HDV (6.5%) mandates HDV RNA testing for all coinfected patients. Patients positive for HDV RNA (characterized by low HBV DNA blood levels) carried HDV genotype 1. Taken together, the significant HDV seroprevalence and the lack of effective anti-HDV therapy, necessitates strict clinical surveillance especially in patients with higher HDV viral loads and increased viral evolution.

Clinical utility of a polymerase chain reaction assay in culture-negative necrotizing otitis externa.

OBJECTIVE: This study describes a subset of necrotizing otitis externa (NOE) patients with a refractory disease and negative cultures. In these cases, we decided to use a polymerase chain reaction (PCR) assay from surgically obtained tissue under sterile conditions to improve pathogen detection sensitivity. STUDY DESIGN: Retrospective case review. SETTING: Academic medical center. PATIENTS: Nineteen consecutive patients diagnosed with NOE between January 2008 and January 2014 inclusive. Three patients of this cohort presented a culture-negative disease. INTERVENTIONS: Diagnostic. MAIN OUTCOME MEASURES: Positive detection of pathogens using a PCR assay in cases with a complicated course of NOE and clinical resolution of the disease after targeted therapy according to PCR results. RESULTS: Surgical samples were obtained under sterile conditions from three patients with negative cultures and a refractory disease course of NOE. PCR assays were performed using pan-bacteria and pan-fungi protocols. In all three samples, a positive result for a fungal pathogen was recorded and followed by successful empirical targeted therapy. CONCLUSION: Patients who present with a refractory culture-negative NOE should be suspected as suffering from a fungal disease. The PCR assay may be an important laboratory adjunct in detecting pathogens responsible for NOE and can aid to promote therapy and disease resolution.

Asymptomatic carriage of Pneumocystis jirovecii and cytomegalovirus in lungs of immunocompetent patients.

PURPOSE: Pneumocystis jirovecii (PCP) and cytomegalovirus (CMV) are opportunistic pathogens which cause lung infection in immunocompromised individuals. However, scarce data are available regarding the carriage of CMV or PCP in immunocompetent, non critically ill patients. The purpose of this study was to evaluate the prevalence of PCP and CMV in broncholaveolar lavage of adult immunocompetent, non critically ill patients. METHODS: BAL fluids from immunocompetent patients who underwent bronchoscopy were analyzed by polymerase chain reaction (PCR) for CMV and PCP DNA. We tested CMV antibodies in serum. In patients with positive CMV DNA in lavage fluid, we further analyzed peripheral blood for the presence of CMV DNA. RESULTS: Ninety three patients were included. We did not detect PCP DNA in BAL in any patient. CMV DNA was found in BAL of 5 of 86 CMV IgG positive patients (5.8 %). Patients who were positive for CMV did not differ from patients with negative PCR for CMV regarding demographic and clinical features. CONCLUSION: We did not find PCP colonization in our cohort of patients. However, we found significant prevalence of CMV DNA in BAL from immunocompetent patients, with no evidence of acute CMV infection. This finding may represent colonization by CMV in immunocompetent, non-critically ill individuals.

Embryonic pig pancreatic tissue for the treatment of diabetes in a nonhuman primate model.

Xenotransplantation of pig tissues has great potential to overcome the shortage of organ donors. One approach to address the vigorous immune rejection associated with xenotransplants is the use of embryonic precursor tissue, which induces and utilizes host vasculature upon its growth and development. Recently, we showed in mice that embryonic pig pancreatic tissue from embryonic day 42 (E42) exhibits optimal properties as a beta cell replacement therapy. We now demonstrate the proof of concept in 2 diabetic Cynomolgus monkeys, followed for 393 and 280 days, respectively. A marked reduction of exogenous insulin requirement was noted by the fourth month after transplantation, reaching complete independence from exogenous insulin during the fifth month after transplantation, with full physiological control of blood glucose levels. The porcine origin of insulin was documented by a radioimmunoassay specific for porcine C-peptide. Furthermore, the growing tissue was found to be predominantly vascularized with host blood vessels, thereby evading hyperacute or acute rejection, which could potentially be mediated by preexisting anti-pig antibodies. Durable graft protection was achieved, and most of the late complications could be attributed to the immunosuppressive protocol. While fine tuning of immune suppression, tissue dose, and implantation techniques are still required, our results demonstrate that porcine E-42 embryonic pancreatic tissue can normalize blood glucose levels in primates. Its long-term proliferative capacity, its revascularization by host endothelium, and its reduced immunogenicity, strongly suggest that this approach could offer an attractive replacement therapy for diabetes.

Incidence and clinical manifestations of adenoviral infection among children undergoing allogeneic stem cell transplantation.

BACKGROUND: Adenoviral infection in children undergoing stem cell transplantation is associated with significant morbidity and mortality. Identification of adenoviral infection by polymerase chain reaction from blood facilitates accurate and rapid diagnosis and surveillance. The incidence of adenoviral infection among children undergoing SCT in Israel is not known. OBJECTIVE: To estimate the incidence of adenoviral infection in pediatric SCT patients and to characterize the morbidity associated with proven infection. METHODS: Blood samples obtained weekly from children who underwent allogeneic SCT were retrospectively tested for adenovirus using standard PCR. A total of 657 samples collected from 32 patients were examined. Correlation was made between the presence of adenovirus in samples and clinical records. RESULTS: Of the 32 patients 4 had adenoviral infection by PCR (12.5%). Clinical disease was present in all four patients concurrent with positive PCR. Gastrointestinal complaints and abnormal hepatocellular enzymes were uniformly present. One patient died due to disseminated disease. T cell depletion was a significant risk factor for adenoviral infection (P = 0.03). CONCLUSIONS: In the patient population studied, the incidence of adenoviral infection in children undergoing SCT was 12.5%. The combination of gastrointestinal symptoms and abnormal hepatocellular enzymes should raise the suspicion of adenoviral infection, especially when occurring during the first few months after SCT.

A novel high-affinity arginine transporter from the human parasitic protozoan Leishmania donovani.

We describe the first functional and molecular characterization of an amino acid permease (LdAAP3) from the human parasitic protozoan Leishmania donovani, the causative agent of visceral leishmaniasis in humans. This permease contains 480 amino acids with 11 predicted trans-membrane domains. Expressing LdAAP3 in Saccharomyces cerevisiae mutants revealed that LdAAP3 codes for a high-affinity arginine transporter (Km 1.9 microM). LdAAP3 is highly specific for arginine as its transport was not inhibited by other amino acids or arginine-related compounds. Using green fluorescence protein (GFP) fused to the N-terminus of LdAAP3, this transporter was localized to the surface membrane of promastigotes. The GFP-LdAAP3 chimera mediated a threefold increase in arginine transport in promastigotes, indicating that it is active and confirmed that LdAAP3 codes for an arginine transporter in parasite cells as well. LdAAP3 is novel as it shares a high level of homology with amino acid permeases from other trypanosomatidae but almost none with permeases from other phyla. The results of this work suggest that LdAAP3 might play a role in host-parasite interaction.

Novel motifs in amino acid permease genes from Leishmania.

Eight amino acid permease genes from the protozoan parasite Leishmania donovani (AAPLDs) were cloned, sequenced, and shown to be expressed in promastigotes. Seven of these belong to the amino acid transporter-1 and one to the amino acid polyamino-choline superfamilies. Using these sequences as well as known and characterized amino acid permease genes from all kingdoms, a training set was established and used to search for motifs, using the MEME motif discovery tool. This study revealed two motifs that are specific to the genus Leishmania, four to the family trypanosomatidae, and a single motif that is common between trypanosomatidae and mammalian systems A1 and N. Interestingly, most of these motifs are clustered in two regions of 50-60 amino acids. Blast search analyses indicated a close relationship between the L. donovani and Trypanosoma brucei amino acid permeases. The results of this work describe the cloning of the first amino acid permease genes in parasitic protozoa and contribute to the understanding of amino acid permease evolution in these organisms. Furthermore, the identification of genus-specific motifs in these proteins might be useful to better understand parasite physiology within its hosts.