Cholesterol Corrects Altered Conformation of MHC-II Protein in Leishmania donovani Infected Macrophages: Implication in Therapy

PubMed Central

Chakrabarti, Saikat; Roy, Syamal

2016-01-01

Background Previously we reported that Kala-azar patients show progressive decrease in serum cholesterol as a function of splenic parasite burden. Splenic macrophages (MΦ) of Leishmania donovani (LD) infected mice show decrease in membrane cholesterol, while LD infected macrophages (I-MΦ) show defective T cell stimulating ability that could be corrected by liposomal delivery of cholesterol. T helper cells recognize peptide antigen in the context of class II MHC molecule. It is known that the conformation of a large number of membrane proteins is dependent on membrane cholesterol. In this investigation we tried to understand the influence of decreased membrane cholesterol in I-MΦ on the conformation of MHC-II protein and peptide-MHC-II stability, and its bearing on the antigen specific T-cell activation. Methodology/Principal Findings MΦ of CBA/j mice were infected with Leishmania donovani (I-MΦ). Two different anti-Aκ mAbs were used to monitor the status of MHC-II protein under parasitized condition. One of them (11.5–2) was conformation specific, whereas the other one (10.2.16) was not. Under parasitized condition, the binding of 11.5–2 decreased significantly with respect to the normal counterpart, whereas that of 10.2.16 remained unaltered. The binding of 11.5–2 was restored to normal upon liposomal delivery of cholesterol in I-MΦ. By molecular dynamics (MD) simulation studies we found that there was considerable conformational fluctuation in the transmembrane domain of the MHC-II protein in the presence of membrane cholesterol than in its absence, which possibly influenced the distal peptide binding groove. This was evident from the faster dissociation of the cognate peptide from peptide-MHC complex under parasitized condition, which could be corrected by liposomal delivery of cholesterol in I-MΦ. Conclusion The decrease in membrane cholesterol in I-MΦ may lead to altered conformation of MHC II, and this may contribute to a faster dissociation of

Genetic Validation of Leishmania donovani Lysyl-tRNA Synthetase Shows that It Is Indispensable for Parasite Growth and Infectivity

PubMed Central

Chadha, Sanya; Mallampudi, N. Arjunreddy; Mohapatra, Debendra K.

2017-01-01

ABSTRACT Leishmania donovani is a protozoan parasite that causes visceral leishmaniasis. Increasing resistance and severe side effects of existing drugs have led to the need to identify new chemotherapeutic targets. Aminoacyl-tRNA synthetases (aaRSs) are ubiquitous and are required for protein synthesis. aaRSs are known drug targets for bacterial and fungal pathogens. Here, we have characterized and evaluated the essentiality of L. donovani lysyl-tRNA synthetase (LdLysRS). Two different coding sequences for lysyl-tRNA synthetases are annotated in the Leishmania genome database. LdLysRS-1 (LdBPK_150270.1), located on chromosome 15, is closer to apicomplexans and eukaryotes, whereas LdLysRS-2 (LdBPK_300130.1), present on chromosome 30, is closer to bacteria. In the present study, we have characterized LdLysRS-1. Recombinant LdLysRS-1 displayed aminoacylation activity, and the protein localized to the cytosol. The LdLysRS-1 heterozygous mutants had a restrictive growth phenotype and attenuated infectivity. LdLysRS-1 appears to be an essential gene, as a chromosomal knockout of LdLysRS-1 could be generated when the gene was provided on a rescuing plasmid. Cladosporin, a fungal secondary metabolite and a known inhibitor of LysRS, was more potent against promastigotes (50% inhibitory concentration [IC50], 4.19 µM) and intracellular amastigotes (IC50, 1.09 µM) than were isomers of cladosporin (3-epi-isocladosporin and isocladosporin). These compounds exhibited low toxicity to mammalian cells. The specificity of inhibition of parasite growth caused by these inhibitors was further assessed using LdLysRS-1 heterozygous mutant strains and rescue mutant promastigotes. These inhibitors inhibited the aminoacylation activity of recombinant LdLysRS. Our data provide a framework for the development of a new class of drugs against this parasite. IMPORTANCE Aminoacyl-tRNA synthetases are housekeeping enzymes essential for protein translation, providing charged tRNAs for the

Genetic Validation of Leishmania donovani Lysyl-tRNA Synthetase Shows that It Is Indispensable for Parasite Growth and Infectivity.

PubMed

Chadha, Sanya; Mallampudi, N Arjunreddy; Mohapatra, Debendra K; Madhubala, Rentala

2017-01-01

Leishmania donovani is a protozoan parasite that causes visceral leishmaniasis. Increasing resistance and severe side effects of existing drugs have led to the need to identify new chemotherapeutic targets. Aminoacyl-tRNA synthetases (aaRSs) are ubiquitous and are required for protein synthesis. aaRSs are known drug targets for bacterial and fungal pathogens. Here, we have characterized and evaluated the essentiality of L. donovani lysyl-tRNA synthetase ( Ld LysRS). Two different coding sequences for lysyl-tRNA synthetases are annotated in the Leishmania genome database. Ld LysRS-1 (LdBPK_150270.1), located on chromosome 15, is closer to apicomplexans and eukaryotes, whereas Ld LysRS-2 (LdBPK_300130.1), present on chromosome 30, is closer to bacteria. In the present study, we have characterized Ld LysRS-1. Recombinant Ld LysRS-1 displayed aminoacylation activity, and the protein localized to the cytosol. The Ld LysRS-1 heterozygous mutants had a restrictive growth phenotype and attenuated infectivity. Ld LysRS-1 appears to be an essential gene, as a chromosomal knockout of Ld LysRS-1 could be generated when the gene was provided on a rescuing plasmid. Cladosporin, a fungal secondary metabolite and a known inhibitor of LysRS, was more potent against promastigotes (50% inhibitory concentration [IC 50 ], 4.19 µM) and intracellular amastigotes (IC 50 , 1.09 µM) than were isomers of cladosporin (3-epi-isocladosporin and isocladosporin). These compounds exhibited low toxicity to mammalian cells. The specificity of inhibition of parasite growth caused by these inhibitors was further assessed using Ld LysRS-1 heterozygous mutant strains and rescue mutant promastigotes. These inhibitors inhibited the aminoacylation activity of recombinant Ld LysRS. Our data provide a framework for the development of a new class of drugs against this parasite. IMPORTANCE Aminoacyl-tRNA synthetases are housekeeping enzymes essential for protein translation, providing charged tRNAs for

l-Arginine Uptake by Cationic Amino Acid Transporter Promotes Intra-Macrophage Survival of Leishmania donovani by Enhancing Arginase-Mediated Polyamine Synthesis

PubMed Central

Mandal, Abhishek; Das, Sushmita; Kumar, Ajay; Roy, Saptarshi; Verma, Sudha; Ghosh, Ayan Kumar; Singh, Ruby; Abhishek, Kumar; Saini, Savita; Sardar, Abul Hasan; Purkait, Bidyut; Kumar, Ashish; Mandal, Chitra; Das, Pradeep

2017-01-01

The survival of intracellular protozoan parasite, Leishmania donovani, the causative agent of Indian visceral leishmaniasis (VL), depends on the activation status of macrophages. l-Arginine, a semi-essential amino acid plays a crucial regulatory role for activation of macrophages. However, the role of l-arginine transport in VL still remains elusive. In this study, we demonstrated that intra-macrophage survival of L. donovani depends on the availability of extracellular l-arginine. Infection of THP-1-derived macrophage/human monocyte-derived macrophage (hMDM) with Leishmania, resulted in upregulation of l-arginine transport. While investigating the involvement of the transporters, we observed that Leishmania survival was greatly impaired when the transporters were blocked either using inhibitor or siRNA-mediated downregulation. CAT-2 was found to be the main isoform associated with l-arginine transport in L. donovani-infected macrophages. l-arginine availability and its transport regulated the host arginase in Leishmania infection. Arginase and inducible nitric oxide synthase (iNOS) expression were reciprocally regulated when assayed using specific inhibitors and siRNA-mediated downregulation. Interestingly, induction of iNOS expression and nitric oxide production were observed in case of inhibition of arginase in infected macrophages. Furthermore, inhibition of l-arginine transport as well as arginase resulted in decreased polyamine production, limiting parasite survival inside macrophages. l-arginine availability and transport regulated Th1/Th2 cytokine levels in case of Leishmania infection. Upregulation of l-arginine transport, induction of host arginase, and enhanced polyamine production were correlated with increased level of IL-10 and decreased level of IL-12 and TNF-α in L. donovani-infected macrophages. Our findings provide clear evidence for targeting the metabolism of l-arginine and l-arginine-metabolizing enzymes as an important therapeutic and

Live Attenuated Leishmania donovani Centrin Knock Out Parasites Generate Non-inferior Protective Immune Response in Aged Mice against Visceral Leishmaniasis.

PubMed

Bhattacharya, Parna; Dey, Ranadhir; Dagur, Pradeep K; Joshi, Amritanshu B; Ismail, Nevien; Gannavaram, Sreenivas; Debrabant, Alain; Akue, Adovi D; KuKuruga, Mark A; Selvapandiyan, Angamuthu; McCoy, John Philip; Nakhasi, Hira L

2016-08-01

Visceral leishmaniasis (VL) caused by the protozoan parasite Leishmania donovani causes severe disease. Age appears to be critical in determining the clinical outcome of VL and at present there is no effective vaccine available against VL for any age group. Previously, we showed that genetically modified live attenuated L. donovani parasites (LdCen-/-) induced a strong protective innate and adaptive immune response in young mice. In this study we analyzed LdCen-/- parasite mediated modulation of innate and adaptive immune response in aged mice (18 months) and compared to young (2 months) mice. Analysis of innate immune response in bone marrow derived dendritic cells (BMDCs) from both young and aged mice upon infection with LdCen-/- parasites, showed significant enhancement of innate effector responses, which consequently augmented CD4+ Th1 cell effector function compared to LdWT infected BMDCs in vitro. Similarly, parasitized splenic dendritic cells from LdCen-/- infected young and aged mice also revealed induction of proinflammatory cytokines (IL-12, IL-6, IFN-γ and TNF) and subsequent down regulation of anti-inflammatory cytokine (IL-10) genes compared to LdWT infected mice. We also evaluated in vivo protection of the LdCen-/- immunized young and aged mice against virulent L. donovani challenge. Immunization with LdCen-/- induced higher IgG2a antibodies, lymphoproliferative response, pro- and anti-inflammatory cytokine responses and stimulated splenocytes for heightened leishmanicidal activity associated with nitric oxide production in young and aged mice. Furthermore, upon virulent L. donovani challenge, LdCen-/- immunized mice from both age groups displayed multifunctional Th1-type CD4 and cytotoxic CD8 T cells correlating to a significantly reduced parasite burden in the spleen and liver compared to naïve mice. It is interesting to note that even though there was no difference in the LdCen-/- induced innate response in dendritic cells between aged and young

Role of inhibitors of serine peptidases in protecting Leishmania donovani against the hydrolytic peptidases of sand fly midgut.

PubMed

Verma, Sudha; Das, Sushmita; Mandal, Abhishek; Ansari, Md Yousuf; Kumari, Sujata; Mansuri, Rani; Kumar, Ajay; Singh, Ruby; Saini, Savita; Abhishek, Kumar; Kumar, Vijay; Sahoo, Ganesh Chandra; Das, Pradeep

2017-06-23

In vector-borne diseases such as leishmaniasis, the sand fly midgut is considered to be an important site for vector-parasite interaction. Digestive enzymes including serine peptidases such as trypsin and chymotrypsin, which are secreted in the midgut are one of the obstacles for Leishmania in establishing a successful infection. The presence of some natural inhibitors of serine peptidases (ISPs) has recently been reported in Leishmania. In the present study, we deciphered the role of these ISPs in the survival of Leishmania donovani in the hostile sand fly midgut environment. In silico and co-immunoprecipitation studies were performed to observe the interaction of L. donovani ISPs with trypsin and chymotrypsin. Zymography and in vitro enzyme assays were carried out to observe the inhibitory effect of purified recombinant ISPs of L. donovani (rLdISPs) on trypsin, chymotrypsin and the sand fly midgut peptidases. The expression of ISPs in the amastigote to promastigote transition stages were studied by semi-quantitative RT-PCR and Western blot. The role of LdISP on the survival of ISP overexpressed (OE) and ISP knocked down (KD) Leishmania parasites inside the sand fly gut was investigated by in vitro and in vivo cell viability assays. We identified two ecotin-like genes in L. donovani, LdISP1 and LdISP2. In silico and co-immunoprecipitation results clearly suggest a strong interaction of LdISP molecules with trypsin and chymotrypsin. Zymography and in vitro enzyme assay confirmed the inhibitory effect of rLdISP on trypsin, chymotrypsin and the sand fly midgut peptidases. The expression of LdISP2 was found to be strongly associated with the amastigote to promastigote phase transition. The activities of the digestive enzymes were found to be significantly reduced in the infected sand flies when compared to uninfected. To our knowledge, our study is the first report showing the possible reduction of chymotrypsin activity in L. donovani infected sand flies compared to

Abietane-Type Diterpenoid Amides with Highly Potent and Selective Activity against Leishmania donovani and Trypanosoma cruzi.

PubMed

Pirttimaa, Minni; Nasereddin, Abedelmajeed; Kopelyanskiy, Dmitry; Kaiser, Marcel; Yli-Kauhaluoma, Jari; Oksman-Caldentey, Kirsi-Marja; Brun, Reto; Jaffe, Charles L; Moreira, Vânia M; Alakurtti, Sami

2016-02-26

Dehydroabietylamine (1) was used as a starting material to synthesize a small library of dehydroabietyl amides by simple and facile methods, and their activities against two disease-causing trypanosomatids, namely, Leishmania donovani and Trypanosoma cruzi, were assayed. The most potent compound, 10, an amide of dehydroabietylamine and acrylic acid, was found to be highly potent against these parasites, displaying an IC50 value of 0.37 μM against L. donovani axenic amastigotes and an outstanding selectivity index of 63. Moreover, compound 10 fully inhibited the growth of intracellular amastigotes in Leishmania donovani-infected human macrophages with a low IC50 value of 0.06 μM. This compound was also highly effective against T. cruzi amastigotes residing in L6 cells with an IC50 value of 0.6 μM and high selectivity index of 58, being 3.5 times more potent than the reference compound benznidazole. The potent activity of this compound and its relatively low cytotoxicity make it attractive for further development in pursuit of better drugs for patients suffering from leishmaniasis and Chagas disease.

Live Attenuated Leishmania donovani Centrin Knock Out Parasites Generate Non-inferior Protective Immune Response in Aged Mice against Visceral Leishmaniasis

PubMed Central

Bhattacharya, Parna; Dey, Ranadhir; Dagur, Pradeep K.; Joshi, Amritanshu B.; Ismail, Nevien; Gannavaram, Sreenivas; Debrabant, Alain; Akue, Adovi D.; KuKuruga, Mark A.; Selvapandiyan, Angamuthu; McCoy, John Philip; Nakhasi, Hira L.

2016-01-01

Background Visceral leishmaniasis (VL) caused by the protozoan parasite Leishmania donovani causes severe disease. Age appears to be critical in determining the clinical outcome of VL and at present there is no effective vaccine available against VL for any age group. Previously, we showed that genetically modified live attenuated L. donovani parasites (LdCen-/-) induced a strong protective innate and adaptive immune response in young mice. In this study we analyzed LdCen-/- parasite mediated modulation of innate and adaptive immune response in aged mice (18 months) and compared to young (2 months) mice. Methodology Analysis of innate immune response in bone marrow derived dendritic cells (BMDCs) from both young and aged mice upon infection with LdCen-/- parasites, showed significant enhancement of innate effector responses, which consequently augmented CD4+ Th1 cell effector function compared to LdWT infected BMDCs in vitro. Similarly, parasitized splenic dendritic cells from LdCen-/- infected young and aged mice also revealed induction of proinflammatory cytokines (IL-12, IL-6, IFN-γ and TNF) and subsequent down regulation of anti-inflammatory cytokine (IL-10) genes compared to LdWT infected mice. We also evaluated in vivo protection of the LdCen-/- immunized young and aged mice against virulent L. donovani challenge. Immunization with LdCen-/- induced higher IgG2a antibodies, lymphoproliferative response, pro- and anti-inflammatory cytokine responses and stimulated splenocytes for heightened leishmanicidal activity associated with nitric oxide production in young and aged mice. Furthermore, upon virulent L. donovani challenge, LdCen-/- immunized mice from both age groups displayed multifunctional Th1-type CD4 and cytotoxic CD8 T cells correlating to a significantly reduced parasite burden in the spleen and liver compared to naïve mice. It is interesting to note that even though there was no difference in the LdCen-/- induced innate response in dendritic cells

Development of a rapid loop-mediated isothermal amplification assay for diagnosis and assessment of cure of Leishmania infection.

PubMed

Verma, Sandeep; Singh, Ruchi; Sharma, Vanila; Bumb, Ram Avtar; Negi, Narendra Singh; Ramesh, V; Salotra, Poonam

2017-03-23

Leishmaniasis is a spectrum of diseases with great relevance to public health. Conventional diagnostic methods are time consuming, needing trained personnel. A robust, rapid and cost effective diagnostic test is warranted for on-time diagnosis and field application. We have developed a loop mediated isothermal amplification (LAMP) assay with primers (n = 6) based on Leishmania donovani kDNA for detection of Leishmania infection, using a closed tube to prevent cross-contamination. The assay was used to detect Leishmania infection in biological samples obtained from patients of visceral leishmaniasis (VL), post kala-azar dermal leishmaniasis (PKDL) and cutaneous leishmaniasis (CL). The assay was positive for L. donovani, L. tropica and L. major parasites, with the highest sensitivity towards L. donovani (1 fg DNA). The high sensitivity of the assay for detection of L. donovani was reflected in its ability to detect parasite DNA within 30 min of amplification time with a threshold detection limit of ≥25 copies per reaction. The assay detected parasite in 64 of 66 VL blood samples (sensitivity, 96.9%; 95% CI: 89.6-99.2%), 15 of 15 VL bone marrow aspirate samples (sensitivity, 100%; 95% CI:79.6-100%), 65 of 67 PKDL tissue biopsy samples (sensitivity, 97%; 95% CI:89.7-99.2%). The assay was evaluated in a few cases of CL wherein it was found positive in 8 of 10 tissue biopsies (sensitivity, 80%; 95% CI: 49-94.3%). The assay was negative in all control blood (n = 76) and tissue biopsy (n = 24) samples (specificity, 100%; 95% CI: 96.3-100%). Further, the assay was evaluated for its utility in assessment of cure in treated VL and PKDL patients. The assay detected parasite DNA in 2 of 20VL blood samples and 2 of 21 PKDL tissue samples. Out of 4 cases that were positive for parasite DNA at post treatment stage, 2 patients (1VL and 1 PKDL) returned with relapse. The study demonstrated a Leishmania genus specific closed tube LAMP assay for reliable and rapid

Genetic Manipulation of Leishmania donovani to Explore the Involvement of Argininosuccinate Synthase in Oxidative Stress Management

PubMed Central

Sardar, Abul Hasan; Jardim, Armando; Ghosh, Ayan Kumar; Mandal, Abhishek; Das, Sushmita; Saini, Savita; Abhishek, Kumar; Singh, Ruby; Verma, Sudha; Kumar, Ajay; Das, Pradeep

2016-01-01

Reactive oxygen and nitrogen species (ROS and RNS) produced by the phagocytic cells are the most common arsenals used to kill the intracellular pathogens. However, Leishmania, an intracellular pathogen, has evolved mechanisms to survive by counterbalancing the toxic oxygen metabolites produced during infection. Polyamines, the major contributor in this anti-oxidant machinery, are largely dependent on the availability of L-arginine in the intracellular milieu. Argininosuccinate synthase (ASS) plays an important role as the rate-limiting step required for converting L-citrulline to argininosuccinate to provide arginine for an assortment of metabolic processes. Leishmania produce an active ASS enzyme, yet it has an incomplete urea cycle as it lacks an argininosuccinate lyase (ASL). There is no evidence for endogenous synthesis of L-arginine in Leishmania, which suggests that these parasites salvage L-arginine from extracellular milieu and makes the biological function of ASS and the production of argininosuccinate in Leishmania unclear. Our previous quantitative proteomic analysis of Leishmania promastigotes treated with sub-lethal doses of ROS, RNS, or a combination of both, led to the identification of several differentially expressed proteins which included ASS. To assess the involvement of ASS in stress management, a mutant cell line with greatly reduced ASS activity was created by a double-targeted gene replacement strategy in L. donovani promastigote. Interestingly, LdASS is encoded by three copies of allele, but Western blot analysis showed the third allele did not appear to express ASS. The free thiol levels in the mutant LdASS-/-/+ cell line were decreased. Furthermore, the cell viability in L-arginine depleted medium was greatly attenuated on exposure to different stress environments and was adversely impacted in its ability to infect mice. These findings suggest that ASS is important for Leishmania donovani to counterbalance the stressed environments

Mechanism of interaction of sitamaquine with Leishmania donovani.

PubMed

Coimbra, E S; Libong, D; Cojean, S; Saint-Pierre-Chazalet, M; Solgadi, A; Le Moyec, L; Duenas-Romero, A M; Chaminade, P; Loiseau, P M

2010-12-01

This study focuses on the mechanism of interaction of sitamaquine with Leishmania donovani membranes, and its accumulation within the parasites. A biomimetic model of the outer layer of a Leishmania plasma membrane was used to examine the interactions of sitamaquine with lipids. The plasma membranes of L. donovani promastigotes were depleted of sterol using cholesterol oxidase, in order to assess the importance of sterols in drug-membrane interactions. Sterols were quantified and sitamaquine susceptibility was assessed using the MTT test. Kinetics of sitamaquine accumulation and efflux were measured under different conditions. Sitamaquine interacts first with phospholipid anionic polar head groups and then with phospholipid acyl chains to insert within biological membranes and accumulates rapidly in the Leishmania cytosol according to a sterol-independent process. The rapid sitamaquine efflux observed was related to an energy-dependent mechanism since the intracellular amount of sitamaquine was enhanced three times in the absence of glucose and the efflux was inhibited in energy-depleted conditions. (1)H NMR analysis of motile lipid showed that sitamaquine did not affect lipid trafficking in Leishmania. We propose that sitamaquine rapidly accumulates in Leishmania by diffusion along an electrical gradient and is concentrated in the cytosol by an energy- and sterol-independent process. The affinity of sitamaquine for membranes was transitory and an energy-dependent efflux was demonstrated, suggesting the presence of an as yet uncharacterized transporter.

Oxidative Stress-Mediated Overexpression of Uracil DNA Glycosylase in Leishmania donovani Confers Tolerance against Antileishmanial Drugs

PubMed Central

Mishra, Anshul; Khan, Mohd. Imran; Jha, Pravin K.; Kumar, Ajay; Das, Prolay; Das, Pradeep

2018-01-01

Leishmania donovani is an intracellular protozoan parasite that causes endemic tropical disease visceral leishmaniasis (VL). Present drugs used against this fatal disease are facing resistance and toxicity issues. Survival of leishmania inside the host cells depends on the parasite's capacity to cope up with highly oxidative environment. Base excision repair (BER) pathway in L. donovani remains unexplored. We studied uracil DNA glycosylase (UNG), the key enzyme involved in BER pathway, and found that the glycosylase activity of recombinant LdUNG (Leishmania donovani UNG) expressed in E. coli is in sync with the activity of the parasite lysate under different reaction conditions. Overexpression of UNG in the parasite enhances its tolerance towards various agents which produce reactive oxygen species (ROS) and shows a higher infectivity in macrophages. Surprisingly, exposure of parasite to amphotericin B and sodium antimony gluconate upregulates the expression of UNG. Further, we found that the drug resistant parasites isolated from VL patients show higher expression of UNG. Mechanisms of action of some currently used drugs include accumulation of ROS. Our findings strongly suggest that targeting LdUNG would be an attractive therapeutic strategy as well as potential measure to tackle the problem of drug resistance in the treatment of leishmaniasis. PMID:29636843

Leishmaniasis in Turkey: Visceral and cutaneous leishmaniasis caused by Leishmania donovani in Turkey.

PubMed

Özbilgin, Ahmet; Harman, Mehmet; Karakuş, Mehmet; Bart, Aldert; Töz, Seray; Kurt, Özgür; Çavuş, İbrahim; Polat, Erdal; Gündüz, Cumhur; Van Gool, Tom; Özbel, Yusuf

2017-09-01

In Turkey, the main causative agents are Leishmania tropica (L. tropica) and Leishmania infantum (L. infantum) for cutaneous leishmaniasis (CL) and L. infantum for visceral leishmaniasis (VL). In this study, we investigated leishmaniasis cases caused by L. donovani and established animal models for understanding its tropism in in vivo conditions. Clinical samples (lesion aspirations and bone marrow) obtained from CL/VL patients were investigated using parasitological (smear/NNN) and DNA-based techniques. For species identification, a real time ITS1-PCR was performed using isolates and results were confirmed by hsp70 PCR-N/sequencing and cpb gene PCR/sequencing in order to reveal Leishmania donovani and Leishmania infantum discrimination. Clinical materials from CL and VL patients were also inoculated into two experimental groups (Group CL and Group VL) of Balb/C mice intraperitoneally for creating clinical picture of Turkish L. donovani strains. After 45days, the samples from visible sores of the skin were taken, and spleens and livers were removed. Measurements of the internal organs were done and touch preparations were prepared for checking the presence of amastigotes. The strains were isolated from all patients and amastigotes were seen in all smears of the patients, and then isolates were immediately stored in liquid nitrogen. In real time ITS1-PCR, the melting temperatures of all samples were out of range of L. infantum, L. tropica and L. major. Sequencing of hsp70 PCR-N showed that all isolates highly identical to previously submitted L. donovani sequences in GenBank, and cpb gene sequencing showed five isolates had longer cpbF allele, whereas one isolate contained a mixed sequence of both cpbF and cpbE. All mice in both experimental groups became infected. Compared to controls, the length and width of both liver and spleen were significantly elevated (p<0.001) in both groups of mice. However, the weight of the liver increased significantly in all mice

Immunization with Live Attenuated Leishmania donovani Centrin−/− Parasites Is Efficacious in Asymptomatic Infection

PubMed Central

Ismail, Nevien; Kaul, Amit; Bhattacharya, Parna; Gannavaram, Sreenivas; Nakhasi, Hira L.

2017-01-01

Currently, there is no vaccine against visceral leishmaniasis (VL). Toward developing an effective vaccine, we have reported extensively on the immunogenicity of live attenuated LdCentrin−/− mutants in naive animal models. In VL endemic areas, asymptomatic carriers outnumber symptomatic cases of VL and are considered to be a reservoir of infection. Vaccination of asymptomatic cases represents a viable strategy to eliminate VL. Immunological correlates of protection thus derived might have limited applicability in conditions where the immunized host has prior exposure to virulent infection. To examine whether LdCen−/− parasites can induce protective immunity in experimental hosts that have low-level parasitemia from a previous exposure mimicking an asymptomatic condition, we infected C57Bl/6 mice with wild-type Leishmania donovani parasites expressing LLO epitope (LdWTLLO 103, i.v.). After 3 weeks, the mice with low levels of parasitemia were immunized with LdCen−/− parasites expressing 2W epitope (LdCen−/−2W 3 × 106 i.v.) to characterize the immune responses in the same host. Antigen experienced CD4+ T cells from the asymptomatic (LdWTLLO infected) LdCen−/−2W immunized, and other control groups were enriched using LLO- and 2W-specific tetramers, followed by Flow cytometric analysis. Our analysis showed that comparable CD4+ T cell proliferation and CD4+ memory T cell responses (TCM) represented by CD62Lhi, CCR7+, and IL-7R+ T cell populations were induced with LdCen−/−2W in both asymptomatic and naive animals that received LdCen−/− immunization. Upon restimulation with peptide, TCM cells differentiated into effector T cells and there was no significant difference in the recall response in animals with asymptomatic infection. Following virulent challenge, comparable reduction in splenic parasite burden was observed in both asymptomatic and naive LdCen−/− immunized animals concomitant with the development of multifunctional CD4

Affinity labeling of the folate-methotrexate transporter from Leishmania donovani

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beck, J.T.; Ullman, B.

1989-08-22

An affinity labeling technique has been developed to identify the folate-methotrexate transporter of Leishmania donovani promastigotes using activated derivatives of the ligands. These activated derivatives were synthesized by incubating folate and methotrexate with a 10-fold excess of 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide (EDC) for 10 min at ambient temperature in dimethyl sulfoxide. When intact wild-type (DI700) Leishmania donovani or preparations of their membranes were incubated with a 0.4 {mu}M concentration of either activated ({sup 3}H)folate or activated ({sup 3}H)methotrexate, the radiolabeled ligands were covalently incorporated into a polypeptide with a molecular weight of approximately 46,000, as demonstrated by SDS-polyacrylamide gel electrophoresis. No affinity labelingmore » of a 46,000-dalton protein was observed when equimolar concentrations of activated radiolabeled ligands were incubated with intact cells or membranes prepared from a methotrexate-resistant mutant clone of Leishmania donovani, MTXA5, that is genetically defective in folate-methotrexate transport capability. Time course studies indicated that maximal labeling of the 46,000-dalton protein occurred within 5-10 min of incubation of intact cells with activated ligand. These studies provide biochemical evidence that the folate-methotrexate transporter of Leishmania donovani can be identified in crude extracts by an affinity labeling technique and serve as a prerequisite to further analysis of the transport protein by providing a vehicle for subsequent purification of this membrane carrier. Moreover, these investigations suggest that the affinity labeling technique using EDC-activated ligands may be exploitable to analyze other cell surface binding proteins in Leishmania donovani, as well as in other organisms.« less

DNA Polymorphism Assay Distinguishes Isolates of Leishmania donovani That Cause Kala-Azar from Those That Cause Post-Kala-Azar Dermal Leishmaniasis in Humans

PubMed Central

Sreenivas, Gannavaram; Subba Raju, B. V.; Singh, Ruchi; Selvapandiyan, Angamuthu; Duncan, Robert; Sarkar, Dwijen; Nakhasi, Hira L.; Salotra, Poonam

2004-01-01

Leishmania donovani in India causes visceral infection (kala-azar) and dermal infection (post-kala-azar dermal leishmaniasis). We report here the identification of polymorphism in a well-defined genetic locus among the Leishmania parasites causing the visceral and dermal manifestations, in a comparison of 15 post-kala-azar dermal leishmaniasis and 12 kala-azar patient isolates. PMID:15071036

Pathogenicity of Leishmania donovani is associated with the high expression of a group low molecular weight proteins

PubMed Central

Mitra, Partha

2015-01-01

Background: With few exceptions, members of the Leishmania donovani complex such as L. donovani, L. infantum and L. chagashi are the etiological agents of visceral leishmaniasis or kala-azar. Promastigotes of Leishmania spp. lose their Pathogenicity; the ability to establish infection in a susceptible host, after prolonged culture. The molecular basis of this evolution of pathogenic to nonpathogenic culture has not been very well understood. It has been proposed that the loss of pathogenicity is associated with the gradual disappearance of selective parasite proteins. An alternative hypothesis is that during prolonged culture, the pathogenic clonal population of the parasite is deleted from the mixed population due to their selection pressure. This clonal deletion is proposed to be responsible for the emergence of the nonpathogenic population. Study Methodology and Results: We have a done a series of two-dimensional polyacrylamide gel electrophoresis followed by western blot experiments to study the antigenic profile of few L. donovani isolates of Indian origin. We observed a gradual and significant downregulation of expression of a group of low molecular weight proteins (LMW, molecular weight 20–30 kDa) which are associated with loss of pathogenicity. These proteins are recognized only by antiserum raised against the whole cell extract of one of the pathogenic Indian L. donovani isolates, Ag83, and remained undetected by antiserum raised against the nonpathogenic AG83 isolates. These LMW proteins were also present in the nonpathogenic extract in very low levels and remained undetected by the virulent serum, indicating a phenomenon of simultaneous downregulation of the expression and altered immunogenicity. LMW proteins were universally expressed in all early passage Indian isolate we tested and also detected in two clones obtained from pathogenic parasite culture. The antigenic patterns of none of the eight clones obtained from nonpathogenic culture were not

Pathogenicity of Leishmania donovani is associated with the high expression of a group low molecular weight proteins.

PubMed

Mitra, Partha

2015-01-01

With few exceptions, members of the Leishmania donovani complex such as L. donovani, L. infantum and L. chagashi are the etiological agents of visceral leishmaniasis or kala-azar. Promastigotes of Leishmania spp. lose their Pathogenicity; the ability to establish infection in a susceptible host, after prolonged culture. The molecular basis of this evolution of pathogenic to nonpathogenic culture has not been very well understood. It has been proposed that the loss of pathogenicity is associated with the gradual disappearance of selective parasite proteins. An alternative hypothesis is that during prolonged culture, the pathogenic clonal population of the parasite is deleted from the mixed population due to their selection pressure. This clonal deletion is proposed to be responsible for the emergence of the nonpathogenic population. We have a done a series of two-dimensional polyacrylamide gel electrophoresis followed by western blot experiments to study the antigenic profile of few L. donovani isolates of Indian origin. We observed a gradual and significant downregulation of expression of a group of low molecular weight proteins (LMW, molecular weight 20-30 kDa) which are associated with loss of pathogenicity. These proteins are recognized only by antiserum raised against the whole cell extract of one of the pathogenic Indian L. donovani isolates, Ag83, and remained undetected by antiserum raised against the nonpathogenic AG83 isolates. These LMW proteins were also present in the nonpathogenic extract in very low levels and remained undetected by the virulent serum, indicating a phenomenon of simultaneous downregulation of the expression and altered immunogenicity. LMW proteins were universally expressed in all early passage Indian isolate we tested and also detected in two clones obtained from pathogenic parasite culture. The antigenic patterns of none of the eight clones obtained from nonpathogenic culture were not exactly similar with the pathogenic clones

Genetically Engineered Ascorbic acid-deficient Live Mutants of Leishmania donovani induce long lasting Protective Immunity against Visceral Leishmaniasis.

PubMed

Anand, Sneha; Madhubala, Rentala

2015-06-02

Visceral leishmaniasis caused by Leishmania donovani is the most severe systemic form of the disease. There are still no vaccines available for humans and there are limitations associated with the current therapeutic regimens for leishmaniasis. Recently, we reported functional importance of Arabino-1, 4-lactone oxidase (ALO) enzyme from L. donovani involved in ascorbate biosynthesis pathway. In this study, we have shown that ΔALO parasites do not affect the ability of null mutants to invade visceral organs but severely impair parasite persistence beyond 16 week in BALB/c mice and hence are safe as an immunogen. Both short term (5 week) and long term (20 week) immunization with ΔALO parasites conferred sustained protection against virulent challenge in BALB/c mice, activated splenocytes and resulted in induction of pro-inflammatory cytokine response. Protection in immunized mice after challenge correlated with the stimulation of IFN-γ producing CD4(+) and CD8(+) T cells. Antigen-mediated cell immunity correlated with robust nitrite and superoxide generation, macrophage-derived oxidants critical in controlling Leishmania infection. Our data shows that live attenuated ΔALO parasites are safe, induce protective immunity and can provide sustained protection against Leishmania donovani. We further conclude that the parasites attenuated in their anti-oxidative defence mechanism can be exploited as vaccine candidates.

Genetically Modified Live Attenuated Leishmania donovani Parasites Induce Innate Immunity through Classical Activation of Macrophages That Direct the Th1 Response in Mice

PubMed Central

Bhattacharya, Parna; Dey, Ranadhir; Dagur, Pradeep K.; Kruhlak, Michael; Ismail, Nevien; Debrabant, Alain; Joshi, Amritanshu B.; Akue, Adovi; Kukuruga, Mark; Takeda, Kazuyo; Selvapandiyan, Angamuthu; McCoy, John Philip

2015-01-01

Visceral leishmaniasis (VL) causes significant mortality and there is no effective vaccine. Previously, we have shown that genetically modified Leishmania donovani parasites, here described as live attenuated parasites, induce a host protective adaptive immune response in various animal models. In this study, we demonstrate an innate immune response upon infection with live attenuated parasites in macrophages from BALB/c mice both in vitro and in vivo. In vitro infection of macrophages with live attenuated parasites (compared to that with wild-type [WT] L. donovani parasites) induced significantly higher production of proinflammatory cytokines (tumor necrosis factor alpha [TNF-α], interleukin-12 [IL-12], gamma interferon [IFN-γ], and IL-6), chemokines (monocyte chemoattractant protein 1/CCL-2, macrophage inflammatory protein 1α/CCL-3, and IP-10), reactive oxygen species (ROS), and nitric oxide, while concomitantly reducing anti-inflammatory cytokine IL-10 and arginase-1 activities, suggesting a dominant classically activated/M1 macrophage response. The classically activated response in turn helps in presenting antigen to T cells, as observed with robust CD4+ T cell activation in vitro. Similarly, parasitized splenic macrophages from live attenuated parasite-infected mice also demonstrated induction of an M1 macrophage phenotype, indicated by upregulation of IL-1β, TNF-α, IL-12, and inducible nitric oxide synthase 2 and downregulation of genes associated with the M2 phenotype, i.e., the IL-10, YM1, Arg-1, and MRC-1 genes, compared to WT L. donovani-infected mice. Furthermore, an ex vivo antigen presentation assay showed macrophages from live attenuated parasite-infected mice induced higher IFN-γ and IL-2 but significantly less IL-10 production by ovalbumin-specific CD4+ T cells, resulting in proliferation of Th1 cells. These data suggest that infection with live attenuated parasites promotes a state of classical activation (M1 dominant) in macrophages that

Genetically Modified Live Attenuated Leishmania donovani Parasites Induce Innate Immunity through Classical Activation of Macrophages That Direct the Th1 Response in Mice.

PubMed

Bhattacharya, Parna; Dey, Ranadhir; Dagur, Pradeep K; Kruhlak, Michael; Ismail, Nevien; Debrabant, Alain; Joshi, Amritanshu B; Akue, Adovi; Kukuruga, Mark; Takeda, Kazuyo; Selvapandiyan, Angamuthu; McCoy, John Philip; Nakhasi, Hira L

2015-10-01

Visceral leishmaniasis (VL) causes significant mortality and there is no effective vaccine. Previously, we have shown that genetically modified Leishmania donovani parasites, here described as live attenuated parasites, induce a host protective adaptive immune response in various animal models. In this study, we demonstrate an innate immune response upon infection with live attenuated parasites in macrophages from BALB/c mice both in vitro and in vivo. In vitro infection of macrophages with live attenuated parasites (compared to that with wild-type [WT] L. donovani parasites) induced significantly higher production of proinflammatory cytokines (tumor necrosis factor alpha [TNF-α], interleukin-12 [IL-12], gamma interferon [IFN-γ], and IL-6), chemokines (monocyte chemoattractant protein 1/CCL-2, macrophage inflammatory protein 1α/CCL-3, and IP-10), reactive oxygen species (ROS), and nitric oxide, while concomitantly reducing anti-inflammatory cytokine IL-10 and arginase-1 activities, suggesting a dominant classically activated/M1 macrophage response. The classically activated response in turn helps in presenting antigen to T cells, as observed with robust CD4(+) T cell activation in vitro. Similarly, parasitized splenic macrophages from live attenuated parasite-infected mice also demonstrated induction of an M1 macrophage phenotype, indicated by upregulation of IL-1β, TNF-α, IL-12, and inducible nitric oxide synthase 2 and downregulation of genes associated with the M2 phenotype, i.e., the IL-10, YM1, Arg-1, and MRC-1 genes, compared to WT L. donovani-infected mice. Furthermore, an ex vivo antigen presentation assay showed macrophages from live attenuated parasite-infected mice induced higher IFN-γ and IL-2 but significantly less IL-10 production by ovalbumin-specific CD4(+) T cells, resulting in proliferation of Th1 cells. These data suggest that infection with live attenuated parasites promotes a state of classical activation (M1 dominant) in macrophages that

Multifaceted Population Structure and Reproductive Strategy in Leishmania donovani Complex in One Sudanese Village

PubMed Central

Hide, Mallorie; Le Falher, Georges; Bucheton, Bruno; Dereure, Jacques; El-Safi, Sayda H.; Dessein, Alain; Bañuls, Anne-Laure

2011-01-01

Leishmania species of the subgenus Leishmania and especially L. donovani are responsible for a large proportion of visceral leishmaniasis cases. The debate on the mode of reproduction and population structure of Leishmania parasites remains opened. It has been suggested that Leishmania parasites could alternate different modes of reproduction, more particularly clonality and frequent recombinations either between related individuals (endogamy) or between unrelated individuals (outcrossing) within strongly isolated subpopulations. To determine whether this assumption is generalized to other species, a population genetics analysis within Leishmania donovani complex strains was conducted within a single village. The results suggest that a mixed-mating reproduction system exists, an important heterogeneity of subsamples and the coexistence of several genetic entities in Sudanese L. donovani. Indeed, results showed significant genetic differentiation between the three taxa (L. donovani, L. infantum and L. archibaldi) and between the human or canine strains of such taxa, suggesting that there may be different imbricated transmission cycles involving either dogs or humans. Results also are in agreement with an almost strict specificity of L. donovani stricto sensu to human hosts. This empirical study demonstrates the complexity of population structure in the genus Leishmania and the need to pursue such kind of analyses at the smallest possible spatio-temporal and ecological scales. PMID:22206035

Targeted killing of Leishmania donovani in vivo and in vitro with amphotericin B attached to functionalized carbon nanotubes.

PubMed

Prajapati, Vijay Kumar; Awasthi, Kalpana; Gautam, Shalini; Yadav, Thakur Prasad; Rai, Madhukar; Srivastava, Onkar Nath; Sundar, Shyam

2011-04-01

This study describes the antileishmanial efficacy of the novel drug formulation of amphotericin B (AmB) attached to functionalized carbon nanotubes (f-CNTs) and compares it with AmB. f-CNTs were prepared in a two-step chemical carboxylation and amidation process. The AmB was then attached to make f-CNT-AmB and its construction was confirmed by Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM). The cytotoxicity of the constructed compound, f-CNT-AmB, was assessed in vitro using the J774A.1 macrophage cell line and in vivo using healthy BALB/c mice. Antileishmanial activity of AmB and f-CNT-AmB was assessed in vitro using a macrophage (J774A.1 cell line) model of Leishmania donovani infection. Antileishmanial activity was assessed in vivo by comparing the parasite load of hamsters treated with a 5 day course of AmB, f-CNTs or f-CNT-AmB initiated at 30 days after infection with L. donovani parasites. The FTIR spectroscopy and TEM data demonstrate the successful attachment of AmB to f-CNTs. The in vitro cytotoxicity of AmB, f-CNTs and f-CNT-AmB was measured by the cytotoxic concentration required to kill 50% of the cells: 0.48±0.06 μg/mL; 7.31±1.16 μg/mL; 0.66±0.17 μg/mL, respectively, in the J774A.1 cell line. The in vivo toxicity assessment of the compounds in BALB/c mice revealed no hepatic or renal toxicity. Against intracellular amastigotes the in vitro antileishmanial efficacy of f-CNT-AmB was significantly higher than that of AmB (IC50 0.00234±0.00075 μg/mL versus 0.03263±0.00123 μg/mL; P≤0.0001). The percentage inhibition of amastigote replication in hamsters treated with f-CNT-AmB was significantly more than that with AmB (89.85%±2.93% versus 68.97%±1.84%; P=0.0004). The results of these experiments clearly demonstrate that f-CNT-AmB has significantly greater antileishmanial efficacy than AmB and had no significant cytotoxic effects.

The emergence of Leishmania major and Leishmania donovani in southern Turkey.

PubMed

Koltas, Ismail S; Eroglu, Fadime; Alabaz, Derya; Uzun, Soner

2014-03-01

In southern Turkey, Leishmania tropica and L. infantum are both the causative agents of cutaneous leishmaniasis (CL) and visceral leishmaniasis (VL), respectively. However, L. major and L. donovani were known to exist after the influx of Syrian refugees. Between the years of July 2003 and July 2013, a total of 167 smears and 113 bone marrow samples were taken from CL and VL-suspected cases, respectively. Samples were analysed through real-time PCR and ITS1 DNA sequencing. One hundred and seven 64% (107/167) smears and 56% (63/113) bone marrow samples were positive for leishmaniasis according to the real-time PCR. Three different Leishmania species were found in the 107 CL cases by real-time PCR: 42% (45/107) L. tropica, 36.5% (39/107) L. infantum and 21.5% (23/107) L. major. In addition, three different Leishmania species were identified in the 63 VL cases: 60.3% (38/63) L. infantum, 30.2% (19/63) L. donovani and 9.5% (6/63) L. tropica using real-time PCR. The results of real-time PCR were confirmed with Leishmania ITS1 DNA sequencing. This study revealed that in southern Turkey, L. major and L. donovani were the aetiological agents of CL and VL, respectively. It was assumed that emergence of L. major and L. donovani was due to influx of Syrian refugees, as well as the effects of global warming.

Probing the structure of Leishmania donovani chagasi DHFR-TS: comparative protein modeling and protein-ligand interaction studies.

PubMed

Maganti, Lakshmi; Manoharan, Prabu; Ghoshal, Nanda

2010-09-01

Dihydrofolate reductase (DHFR) has been used successfully as a drug target in the area of anti-bacterial, anti-cancer and anti-malarial therapy. It also acts as a drug target for Leishmaniasis. Inhibition of DHFR leads to cell death through lack of thymine (nucleotide metabolism). Although the crystal structures of Leishmania major and Trypanosoma cruzi DHFR-thymidylate synthase (TS) have been resolved, to date there is no three-dimensional (3D)-structural information on DHFR-TS of Leishmania donovani chagasi, which causes visceral leishmaniasis. Our aim in this study was to model the 3D structure of L. donovani chagasi DHFR-TS, and to investigate the structural requirements for its inhibition. In this paper we describe a highly refined homology model of L. donovani chagasi DHFR-TS based on available crystallographic structures by using the Homology module of Insight II. Structural refinement and minimization of the generated L. donovani chagasi DHFR-TS model employed the Discover 3 module of Insight II and molecular dynamic simulations. The model was further validated through use of the PROCHECK, Verify_3D, PROSA, PSQS and ERRAT programs, which confirm that the model is reliable. Superimposition of the model structure with the templates L. major A chain, L. major B chain And T. cruzi A chain showed root mean square deviations of 0.69 A, 0.71 A and 1.11 A, respectively. Docking analysis of the L. donovani chagasi DHFR-TS model with methotrexate enabled us to identify specific residues, viz. Val156, Val30, Lys95, Lys75 and Arg97, within the L. donovani chagasi DHFR-TS binding pocket, that play an important role in ligand or substrate binding. Docking studies clearly indicated that these five residues are important determinants for binding as they have strong hydrogen bonding interactions with the ligand.

Genetic diversity of Leishmania donovani that causes cutaneous leishmaniasis in Sri Lanka: a cross sectional study with regional comparisons.

PubMed

Kariyawasam, Udeshika Lakmini; Selvapandiyan, Angamuthu; Rai, Keshav; Wani, Tasaduq Hussain; Ahuja, Kavita; Beg, Mizra Adil; Premathilake, Hasitha Upendra; Bhattarai, Narayan Raj; Siriwardena, Yamuna Deepani; Zhong, Daibin; Zhou, Guofa; Rijal, Suman; Nakhasi, Hira; Karunaweera, Nadira D

2017-12-22

Leishmania donovani is the etiological agent of visceral leishmaniasis (VL) in the Indian subcontinent. However, it is also known to cause cutaneous leishmaniasis (CL) in Sri Lanka. Sri Lankan L. donovani differs from other L. donovani strains, both at the molecular and biochemical level. To investigate the different species or strain-specific differences of L. donovani in Sri Lanka we evaluated sequence variation of the kinetoplastid DNA (kDNA). Parasites isolated from skin lesions of 34 CL patients and bone marrow aspirates from 4 VL patients were genotyped using the kDNA minicircle PCR analysis. A total of 301 minicircle sequences that included sequences from Sri Lanka, India, Nepal and six reference species of Leishmania were analyzed. Haplotype diversity of Sri Lankan isolates were high (H d  = 0.757) with strong inter-geographical genetic differentiation (F ST  > 0.25). In this study, L. donovani isolates clustered according to their geographic origin, while Sri Lankan isolates formed a separate cluster and were clearly distinct from other Leishmania species. Within the Sri Lankan group, there were three distinct sub-clusters formed, from CL patients who responded to standard antimony therapy, CL patients who responded poorly to antimony therapy and from VL patients. There was no specific clustering of sequences based on geographical origin within Sri Lanka. This study reveals high levels of haplotype diversity of L. donovani in Sri Lanka with a distinct genetic association with clinically relevant phenotypic characteristics. The use of genetic tools to identify clinically relevant features of Leishmania parasites has important therapeutic implications for leishmaniasis.

Novel agmatine analogue, {gamma}-guanidinooxypropylamine (GAPA) efficiently inhibits proliferation of Leishmania donovani by depletion of intracellular polyamine levels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Sushma; Jhingran, Anupam; Sharma, Ankur

2008-10-10

The efficacy of {gamma}-guanidinooxypropylamine (GAPA), a novel agmatine analogue against protozoan parasite, Leishmaniadonovani was evaluated. Wild-type and ornithine decarboxylase-overexpressors of L. donovani were used to study the effect and mode of action of this inhibitor. GAPA inhibited the growth of both promastigotes and amastigotes. Ornithine decarboxylase (ODC) activity and polyamine levels were markedly lower in cells treated with GAPA and proliferation was rescued by addition of putrescine or spermidine. GAPA inhibited L. donovani recombinant ODC with K{sub i} value of {approx}60 {mu}M. The ODC-overexpressors showed significant resistance to GAPA. GAPA has pK{sub a} 6.71 and at physiological pH the analoguemore » can mimic protonated state of putrescine and can probably use putrescine transport system. Transport of putrescine in wild-type L. donovani promastigotes was inhibited by GAPA. We for the first time report that GAPA is a potential antileishmanial lead compound and it possibly inhibits L. donovani growth by depletion of intracellular polyamine levels.« less

Real-time PCR in detection and quantitation of Leishmania donovani for the diagnosis of Visceral Leishmaniasis patients and the monitoring of their response to treatment

PubMed Central

Ghosh, Prakash; Khan, Md. Anik Ashfaq; Duthie, Malcolm S.; Vallur, Aarthy C.; Picone, Alessandro; Howard, Randall F.; Reed, Steven G.

2017-01-01

Sustained elimination of Visceral Leishmaniasis (VL) requires the reduction and control of parasite reservoirs to minimize the transmission of Leishmania donovani infection. A simple, reproducible and definitive diagnostic procedure is therefore indispensable for the early and accurate detection of parasites in VL, Relapsed VL (RVL) and Post Kala-azar Dermal Leishmaniasis (PKDL) patients, all of whom are potential reservoirs of Leishmania parasites. To overcome the limitations of current diagnostic approaches, a novel quantitative real-time polymerase chain reaction (qPCR) method based on Taqman chemistry was devised for the detection and quantification of L. donovani in blood and skin. The diagnostic efficacy was evaluated using archived peripheral blood buffy coat DNA from 40 VL, 40 PKDL, 10 RVL, 20 cured VL, and 40 cured PKDL along with 10 tuberculosis (TB) cases and 80 healthy endemic controls. Results were compared to those obtained using a Leishmania-specific nested PCR (Ln-PCR). The real time PCR assay was 100% (95% CI, 91.19–100%) sensitive in detecting parasite genomes in VL and RVL samples and 85.0% (95% CI, 70.16–94.29%) sensitive for PKDL samples. In contrast, the sensitivity of Ln-PCR was 77.5% (95% CI, 61.55–89.16%) for VL samples, 100% (95%CI, 69.15–100%) for RVL samples, and 52.5% (95% CI, 36.13–68.49%) for PKDL samples. There was significant discordance between the two methods with the overall sensitivity of the qPCR assay being considerably higher than Ln-PCR. None of the assay detected L. donovani DNA in buffy coats from cured VL cases, and reduced infectious burdens were demonstrated in cured PKDL cases who remained positive in 7.5% (3/40) and 2.5% (1/40) cases by real-time PCR and Ln-PCR, respectively. Both assays were 100% (95% CI, 95.98–100) specific with no positive signals in either endemic healthy control or TB samples. The real time PCR assay we developed offers a molecular tool for accurate detection of circulating L

Molecular Mechanisms of In vitro Betulin-Induced Apoptosis of Leishmania donovani

PubMed Central

Saudagar, Prakash; Dubey, Vikash Kumar

2014-01-01

Although leishmanial infections of humans occur globally, the major health impact lies in developing nations, thus, leishmaniases remain “neglected” diseases for new drugs development. Multidrug resistance has been documented in most countries where leishmaniases is endemic. Betulin is a widely available and affordable natural product exerting leishmanicidal activity at micromolar concentration. In this study, the molecular mechanisms of death that contribute to the anti-leishmanial activity of betulin are investigated. In promastigotes, betulin stimulated reactive oxygen species generation at micromolar concentrations in Leishmania. Apoptosis was observed in betulin-treated promastigotes using flow cytometric analysis of treated cells stained with annexin V-FITC and propidium iodide. Furthermore, betulin treatment of promastigotes led to mitochondrial membrane damage, activation of caspase-like proteases, and DNA fragmentation in Leishmania donovani promastigotes. Betulin treatment of amastigotes cultured within macrophages, resulted in a reduced number of amastigotes, with no substantive cytotoxic damage to the host macrophage cells at leishmanicidal drug concentrations. PMID:24420777

A study of a self diagnostic platform for the detection of A2 biomarker for Leishmania donovani

NASA Astrophysics Data System (ADS)

Roche, Philip J. R.; Cheung, Maurice C.; Najih, Mohamed; McCall, Laura-Isobel; Fakih, Ibrahim; Chodavarapu, Vamsy P.; Ward, Brian; Ndao, Momar; Kirk, Andrew G.

2012-03-01

Visceral leishmaniasis (L.donovani) is a protozoan infection that attacks mononuclear phagocytes and causes the liver and spleen damage that can cause death. The investigation presented is a proof of concept development applying a plasmonic diagnostic platform with simple microfluidic sample delivery and optical readout. An immune-assay method is applied to the quantification of A2 protein, a highly immunogenic biomarker for the pathogen. Quantification of A2 was performed in the ng/ml range, analysis by ELISA suggested that a limit of 0.1ng/ml of A2 is approximate to 1 pathogen per ml and the sensing system shows the potential to deliver a similar level of quantification. Significant reduction in assay complexity as further enzyme linked enhancement is not required when applying a plasmonic methodology to an immunoassay. The basic instrumentation required for a portable device and potential dual optical readout where both plasmonic and photoluminescent response are assessed and investigated including consideration of the application of the device to testing where non-literate communication of results is considered and issues of performance are addressed.

Multilocus Microsatellite Typing (MLMT) of Strains from Turkey and Cyprus Reveals a Novel Monophyletic L. donovani Sensu Lato Group

PubMed Central

Amro, Ahmad; Mentis, Andreas; Pratlong, Francine; Dedet, Jean-Pierre; Votypka, Jan; Volf, Petr; Ozensoy Toz, Seray; Kuhls, Katrin; Schönian, Gabriele; Soteriadou, Ketty

2012-01-01

Background New foci of human CL caused by strains of the Leishmania donovani (L. donovani) complex have been recently described in Cyprus and the Çukurova region in Turkey (L. infantum) situated 150 km north of Cyprus. Cypriot strains were typed by Multilocus Enzyme Electrophoresis (MLEE) using the Montpellier (MON) system as L. donovani zymodeme MON-37. However, multilocus microsatellite typing (MLMT) has shown that this zymodeme is paraphyletic; composed of distantly related genetic subgroups of different geographical origin. Consequently the origin of the Cypriot strains remained enigmatic. Methodology/Principal Findings The Cypriot strains were compared with a set of Turkish isolates obtained from a CL patient and sand fly vectors in south-east Turkey (Çukurova region; CUK strains) and from a VL patient in the south-west (Kuşadasi; EP59 strain). These Turkish strains were initially analyzed using the K26-PCR assay that discriminates MON-1 strains by their amplicon size. In line with previous DNA-based data, the strains were inferred to the L. donovani complex and characterized as non MON-1. For these strains MLEE typing revealed two novel zymodemes; L. donovani MON-309 (CUK strains) and MON-308 (EP59). A population genetic analysis of the Turkish isolates was performed using 14 hyper-variable microsatellite loci. The genotypic profiles of 68 previously analyzed L. donovani complex strains from major endemic regions were included for comparison. Population structures were inferred by combination of Bayesian model-based and distance-based approaches. MLMT placed the Turkish and Cypriot strains in a subclade of a newly discovered, genetically distinct L. infantum monophyletic group, suggesting that the Cypriot strains may originate from Turkey. Conclusion The discovery of a genetically distinct L. infantum monophyletic group in the south-eastern Mediterranean stresses the importance of species genetic characterization towards better understanding, monitoring

Leishmania donovani chaperonin 10 regulates parasite internalization and intracellular survival in human macrophages.

PubMed

Colineau, Lucie; Clos, Joachim; Moon, Kyung-Mee; Foster, Leonard J; Reiner, Neil E

2017-06-01

Protozoa of the genus Leishmania infect macrophages in their mammalian hosts causing a spectrum of diseases known as the leishmaniases. The search for leishmania effectors that support macrophage infection is a focus of significant interest. One such candidate is leishmania chaperonin 10 (CPN10) which is secreted in exosomes and may have immunosuppressive properties. Here, we report for the first time that leishmania CPN10 localizes to the cytosol of infected macrophages. Next, we generated two genetically modified strains of Leishmania donovani (Ld): one strain overexpressing CPN10 (CPN10+++) and the second, a CPN10 single allele knockdown (CPN10+/-), as the null mutant was lethal. When compared with the wild-type (WT) parental strain, CPN10+/- Ld showed higher infection rates and parasite loads in human macrophages after 24 h of infection. Conversely, CPN10+++ Ld was associated with lower initial infection rates. This unexpected apparent gain-of-function for the knockdown could have been explained either by enhanced parasite internalization or by enhanced intracellular survival. Paradoxically, we found that CPN10+/- leishmania were more readily internalized than WT Ld, but also displayed significantly impaired intracellular survival. This suggests that leishmania CPN10 negatively regulates the rate of parasite uptake by macrophages while being required for intracellular survival. Finally, quantitative proteomics identified an array of leishmania proteins whose expression was positively regulated by CPN10. In contrast, many macrophage proteins involved in innate immunity were negatively regulated by CPN10. Taken together, these findings identify leishmania CPN10 as a novel effector with broad based effects on macrophage cell regulation and parasite survival.

Alkaloids and leishmania donovani UDP-galactopyarnose mutase: Anovel approach in drug designing against Visceral leishmaniasis.

PubMed

Srivastava, Ankita; Chandra, Deepak

2017-06-05

The unsatisfactory treatment options for Visceral Leishmaniasis (VL), needs identification of new drug targets. Among natural products, Alkaloids have been proved to be highly effective against number of diseases. In Leishmania UDP-galactopyranose mutase (UGM) is a critical enzyme required for cell wall synthesis and thus a drug target for structure based drug designing against L. donovani. To build the homology model of UDP galactopyranse mutase and investigate the interaction of selected alkaloids with this modeled UDP galactopyranose mutase by molecular docking. Since there is no crystal structure record has been found with this protein, a homology modeling was performed and a three dimensional structure of L. donovani UGM was created using MODELLER v9.9, structure quality was validated using PROCHECK and QMEAN programs which confirms that the structure is reliable. Further Molecular docking was performed with previously reported 15 alkaloids. It was found that Protopine shows a binding energy of -12.39Kcal/mole, binds at Flavin adenine dinucleotide (FAD) biding site. Concluding that Protopine, an alkaloid could interrupt the functional aspect of L. donovani UGM and thus may be useful for drug designing studies. These finding would contribute to the understanding of effect of drug on the parasite. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Identification of Leishmania donovani Topoisomerase 1 inhibitors via intuitive scaffold hopping and bioisosteric modification of known Top 1 inhibitors

NASA Astrophysics Data System (ADS)

Mamidala, Rajinikanth; Majumdar, Papiya; Jha, Kunal Kumar; Bathula, Chandramohan; Agarwal, Rahul; Chary, M. Thirumala; Mazumdar, H. K.; Munshi, Parthapratim; Sen, Subhabrata

2016-05-01

A library of arylidenefuropyridinediones was discovered as potent inhibitors of Leishmania donovani Topoisomerase 1 (LdTop1) where the active molecules displayed considerable inhibition with single digit micromolar EC50 values. This molecular library was designed via intuitive scaffold hopping and bioisosteric modification of known topoisomerase 1 inhibitors such as camptothecin, edotecarin and etc. The design was rationalized by molecular docking analysis of the compound prototype with human topoisomerase 1 (HTop1) and Leishmania donovani topoisomerase 1(LdTop1). The most active compound 4 displayed no cytotoxicity against normal mammalian COS7 cell line (~100 fold less inhibition at the EC50). Similar to camptothecin, 4 interacted with free LdTop1 as observed in the preincubation DNA relaxation inhibition experiment. It also displayed anti-protozoal activity against Leishmania donovani promastigote. Crystal structure investigation of 4 and its molecular modelling with LdTop1 revealed putative binding sites in the enzyme that could be harnessed to generate molecules with better potency.

Leishmania donovani resides in modified early endosomes by upregulating Rab5a expression via the downregulation of miR-494

PubMed Central

Verma, Jitender Kumar; Rastogi, Ruchir

2017-01-01

Several intracellular pathogens arrest the phagosome maturation in the host cells to avoid transport to lysosomes. In contrast, the Leishmania containing parasitophorous vacuole (PV) is shown to recruit lysosomal markers and thus Leishmania is postulated to be residing in the phagolysosomes in macrophages. Here, we report that Leishmania donovani specifically upregulates the expression of Rab5a by degrading c-Jun via their metalloprotease gp63 to downregulate the expression of miR-494 in THP-1 differentiated human macrophages. Our results also show that miR-494 negatively regulates the expression of Rab5a in cells. Subsequently, L. donovani recruits and retains Rab5a and EEA1 on PV to reside in early endosomes and inhibits transport to lysosomes in human macrophages. Similarly, we have also observed that Leishmania PV also recruits Rab5a by upregulating its expression in human PBMC differentiated macrophages. However, the parasite modulates the endosome by recruiting Lamp1 and inactive pro-CathepsinD on PV via the overexpression of Rab5a in infected cells. Furthermore, siRNA knockdown of Rab5a or overexpression of miR-494 in human macrophages significantly inhibits the survival of the parasites. These results provide the first mechanistic insights of parasite-mediated remodeling of endo-lysosomal trafficking to reside in a specialized early endocytic compartment. PMID:28650977

Cytosolic tryparedoxin of Leishmania donovani modulates host immune response in visceral leishmaniasis.

PubMed

Suman, Shashi Shekhar; Amit, Ajay; Singh, Krishn Pratap; Gupta, Parool; Equbal, Asif; Kumari, Arti; Topno, Roshan Kamal; Ravidas, Vidyananda; Pandey, Krishna; Bimal, Sanjiva; Das, Pradeep; Ali, Vahab

2018-08-01

Leishmaniasis is a neglected tropical disease caused by the unicellular protozoan parasite of genus Leishmania. Tryparedoxin (TXN) is a low molecular mass dithiol protein belonging to oxidoreductases super-family; which function in concert with tryparedoxin peroxidase (TXNPx) as a system in protozoan parasites including Leishmania. Leishmanial hydroperoxides detoxification cascade uses trypanothione as electron donor to reduce hydroperoxide inside the macrophages during infection. However, the mechanism by which tryparedoxin can contribute in progression of visceral leishmaniasis (VL) and its impact on host's cellular immune response during infection in Indian VL patient is unknown. In this study, we purified a ∼17 kDa recombinant cytosolic tryparedoxin (cTXN) protein of Leishmania donovani (rLdcTXN) and investigated its immunological responses in peripheral blood monocytes (PBMC) isolated from VL patients. The protein significantly enhanced the promastigotes count after 96 h of culture showing a direct correlation with parasite growth. Furthermore, stimulation of PBMC isolated from VL patients with rLdcTXN resulted in up-regulation of IL-4 and IL-10 production whereas IL-12 and IFN-γ was significantly down-regulated suggesting a pivotal role of cTXN in provoking the immune suppression during VL. Our study demonstrates the importance of cTXN protein which can potentially modulate the outcome of disease through suppressing host protective Th1 response in VL patients. Copyright © 2018 Elsevier Ltd. All rights reserved.

Leishmanization revisited: immunization with a naturally attenuated cutaneous Leishmania donovani isolate from Sri Lanka protects against visceral leishmaniasis.

PubMed

McCall, Laura-Isobel; Zhang, Wen-Wei; Ranasinghe, Shanlindra; Matlashewski, Greg

2013-02-27

Leishmaniasis is a neglected tropical disease caused by Leishmania protozoa and associated with three main clinical presentations: cutaneous, mucocutaneous and visceral leishmaniasis. Visceral leishmaniasis is the second most lethal parasitic disease after malaria and there is so far no human vaccine. Leishmania donovani is a causative agent of visceral leishmaniasis in South East Asia and Eastern Africa. However, in Sri Lanka, L. donovani causes mainly cutaneous leishmaniasis, while visceral leishmaniasis is rare. We investigate here the possibility that the cutaneous form of L. donovani can provide immunological protection against the visceral form of the disease, as a potential explanation for why visceral leishmaniasis is rare in Sri Lanka. Subcutaneous immunization with a cutaneous clinical isolate from Sri Lanka was significantly protective against visceral leishmaniasis in BALB/c mice. Protection was associated with a mixed Th1/Th2 response. These results provide a possible rationale for the scarcity of visceral leishmaniasis in Sri Lanka and could guide leishmaniasis vaccine development efforts. Copyright © 2012 Elsevier Ltd. All rights reserved.

2-Alkynoic fatty acids inhibit topoisomerase IB from Leishmania donovani.

PubMed

Carballeira, Néstor M; Cartagena, Michelle; Sanabria, David; Tasdemir, Deniz; Prada, Christopher F; Reguera, Rosa M; Balaña-Fouce, Rafael

2012-10-01

2-Alkynoic fatty acids display antimycobacterial, antifungal, and pesticidal activities but their antiprotozoal activity has received little attention. In this work we synthesized the 2-octadecynoic acid (2-ODA), 2-hexadecynoic acid (2-HDA), and 2-tetradecynoic acid (2-TDA) and show that 2-ODA is the best inhibitor of the Leishmania donovani DNA topoisomerase IB enzyme (LdTopIB) with an EC(50)=5.3±0.7μM. The potency of LdTopIB inhibition follows the trend 2-ODA>2-HDA>2-TDA, indicating that the effectiveness of inhibition depends on the fatty acid carbon chain length. All of the studied 2-alkynoic fatty acids were less potent inhibitors of the human topoisomerase IB enzyme (hTopIB) as compared to LdTopIB. 2-ODA also displayed in vitro activity against Leishmania donovani (IC(50)=11.0μM), but it was less effective against other protozoa, Trypanosoma cruzi (IC(50)=48.1μM) and Trypanosoma brucei rhodesiense (IC(50)=64.5μM). The antiprotozoal activity of the 2-alkynoic fatty acids, in general, followed the trend 2-ODA>2-HDA>2-TDA. The experimental information gathered so far indicates that 2-ODA is a promising antileishmanial compound. Copyright © 2012 Elsevier Ltd. All rights reserved.

Intracellular zinc flux causes reactive oxygen species mediated mitochondrial dysfunction leading to cell death in Leishmania donovani.

PubMed

Kumari, Anjali; Singh, Krishn Pratap; Mandal, Abhishek; Paswan, Ranjeet Kumar; Sinha, Preeti; Das, Pradeep; Ali, Vahab; Bimal, Sanjiva; Lal, Chandra Shekhar

2017-01-01

Leishmaniasis caused by Leishmania parasite is a global threat to public health and one of the most neglected tropical diseases. Therefore, the discovery of novel drug targets and effective drug is a major challenge and an important goal. Leishmania is an obligate intracellular parasite that alternates between sand fly and human host. To survive and establish infections, Leishmania parasites scavenge and internalize nutrients from the host. Nevertheless, host cells presents mechanism like nutrient restriction to inhibit microbial growth and control infection. Zinc is crucial for cellular growth and disruption in its homeostasis hinders growth and survival in many cells. However, little is known about the role of zinc in Leishmania growth and survival. In this study, the effect of zinc on the growth and survival of L.donovani was analyzed by both Zinc-depletion and Zinc-supplementation using Zinc-specific chelator N, N, N', N'-tetrakis (2-pyridylmethyl) ethylenediamine (TPEN) and Zinc Sulfate (ZnSO4). Treatment of parasites with TPEN rather than ZnSO4 had significantly affected the growth in a dose- and time-dependent manner. The pre-treatment of promastigotes with TPEN resulted into reduced host-parasite interaction as indicated by decreased association index. Zn depletion resulted into flux in intracellular labile Zn pool and increased in ROS generation correlated with decreased intracellular total thiol and retention of plasma membrane integrity without phosphatidylserine exposure in TPEN treated promastigotes. We also observed that TPEN-induced Zn depletion resulted into collapse of mitochondrial membrane potential which is associated with increase in cytosolic calcium and cytochrome-c. DNA fragmentation analysis showed increased DNA fragments in Zn-depleted cells. In summary, intracellular Zn depletion in the L. donovani promastigotes led to ROS-mediated caspase-independent mitochondrial dysfunction resulting into apoptosis-like cell death. Therefore, cellular

Recombinant NAD-dependent SIR-2 protein of Leishmania donovani: immunobiochemical characterization as a potential vaccine against visceral leishmaniasis.

PubMed

Baharia, Rajendra K; Tandon, Rati; Sharma, Tanuj; Suthar, Manish K; Das, Sanchita; Siddiqi, Mohammad Imran; Saxena, Jitendra Kumar; Sundar, Shaym; Sunder, Shyam; Dube, Anuradha

2015-03-01

The development of a vaccine conferring long-lasting immunity remains a challenge against visceral leishmaniasis (VL). Immunoproteomic characterization of Leishmania donovani proteins led to the identification of a novel protein NAD+-dependent Silent Information regulatory-2 (SIR2 family or sirtuin) protein (LdSir2RP) as one of the potent immunostimulatory proteins. Proteins of the SIR2 family are characterized by a conserved catalytic domain that exerts unique NAD-dependent deacetylase activity. In the present study, an immunobiochemical characterization of LdSir2RP and further evaluation of its immunogenicity and prophylactic potential was done to assess for its possible involvement as a vaccine candidate against leishmaniasis. LdSir2RP was successfully cloned, expressed and purified. The gene was present as a monomeric protein of ~45 kDa and further established by the crosslinking experiment. rLdSir2RP shown cytosolic localization in L. donovani and demonstrating NAD+-dependent deacetylase activity. Bioinformatic analysis also confirmed that LdSir2RP protein has NAD binding domain. The rLdSir2RP was further assessed for its cellular response by lymphoproliferative assay and cytokine ELISA in cured Leishmania patients and hamsters (Mesocricetus auratus) in comparison to soluble Leishmania antigen and it was observed to stimulate the production of IFN-γ, IL-12 and TNF-α significantly but not the IL-4 and IL-10. The naïve hamsters when vaccinated with rLdSir2RP alongwith BCG resisted the L. donovani challenge to the tune of ~75% and generated strong IL-12 and IFN-γ mediated Th1 type immune response thereof. The efficacy was further supported by remarkable increase in IgG2 antibody level which is indicative of Th1 type of protective response. Further, with a possible implication in vaccine design against VL, identification of potential T-cell epitopes of rLdSir2RP was done using computational approach. The immunobiochemical characterization strongly suggest the

Characterization of a ricin-resistant mutant of Leishmania donovani that expresses lipophosphoglycan

PubMed Central

Phillips, Megan R; Turco, Salvatore J

2015-01-01

The abundant cell-surface lipophosphoglycan (LPG) of Leishmania parasites plays a central role throughout the eukaryote's life cycle. A number of LPG-defective mutants and their complementing genes have been isolated and have proven invaluable in assessing the importance of LPG and related glycoconjugates in parasite virulence. While ricin agglutination selection protocols frequently result in lpg− mutants, one  Leishmania donovani variant we isolated, named JABBA, was found to be lpg+. Procyclic (logarithmic) JABBA expresses significant amounts of a large-sized LPG, larger than observed from procyclic wild type but similar in size to LPG from wild type from metacyclic (stationary) phase. Structural analysis of the LPG from logarithmically grown JABBA by capillary electrophoresis protocols revealed that it averaged 30 repeat units composed of the unsubstituted Gal(β1,4)Man(α1)-PO4 typical of wild-type L. donovani. Analysis of JABBA LPG caps indicated that 20% is branched trisaccharide Gal(β1,4)[Glc(β1,2)]Man and tetrasaccharide Gal(β1,4)[Glc(β1,2)Man(α1,2)]Man instead of the usual Gal(β1,4)Man and Man(α1,2)Man terminating caps. Consistent with these structural observations, analyses of the relevant glycosyltransferases in JABBA microsomes involved in LPG biosynthesis showed a 2-fold increase in elongating mannosylphosphoryltransferase activity and up-regulation of a β-glucosyltransferase activity. Furthermore, the caps of JABBA LPG are cryptic in presentation as shown by the loss of binding by the lectins, ricin, peanut agglutinin and concanavalin A and reduced accessibility of the terminal galactose residues to oxidation by galactose oxidase. These results indicate that LPG from JABBA is intriguingly similar to the larger LPG in wild-type parasites that arises following the differentiation of the non-infectious procyclic promastigotes to infectious, metacyclic forms. PMID:25472443

The Malnutrition-Related Increase in Early Visceralization of Leishmania donovani Is Associated with a Reduced Number of Lymph Node Phagocytes and Altered Conduit System Flow

PubMed Central

Ibrahim, Marwa K.; Barnes, Jeffrey L.; Anstead, Gregory M.; Jimenez, Fabio; Travi, Bruno L.; Peniche, Alex G.; Osorio, E. Yaneth; Ahuja, Seema S.; Melby, Peter C.

2013-01-01

In a murine model of moderate childhood malnutrition we found that polynutrient deficiency led to a 4–5-fold increase in early visceralization of L. donovani (3 days post-infection) following cutaneous infection and a 16-fold decrease in lymph node barrier function (p<0.04 for all). To begin to understand the mechanistic basis for this malnutrition-related parasite dissemination we analyzed the cellularity, architecture, and function of the skin-draining lymph node. There was no difference in the localization of multiple cell populations in the lymph node of polynutrient deficient (PND) mice, but there was reduced cellularity with fewer CD11c+dendritic cells (DCs), fibroblastic reticular cells (FRCs), MOMA-2+ macrophages, and CD169+ subcapsular sinus macrophage (p<0.05 for all) compared to the well-nourished (WN) mice. The parasites were equally co-localized with DCs associated with the lymph node conduit network in the WN and PND mice, and were found in the high endothelial venule into which the conduits drain. When a fluorescent low molecular weight (10 kD) dextran was delivered in the skin, there was greater efflux of the marker from the lymph node conduit system to the spleens of PND mice (p<0.04), indicating that flow through the conduit system was altered. There was no evidence of disruption of the conduit or subcapsular sinus architecture, indicating that the movement of parasites into the subcortical conduit region was due to an active process and not from passive movement through a leaking barrier. These results indicate that the impaired capacity of the lymph node to act as a barrier to dissemination of L. donovani infection is associated with a reduced number of lymph node phagocytes, which most likely leads to reduced capture of parasites as they transit through the sinuses and conduit system. PMID:23967356

First identification of the causative agent of visceral leishmaniasis in Djibouti: Leishmania donovani.

PubMed

Pratlong, F; Debord, T; Garnotel, E; Garrabé, E; Marty, P; Raphenon, G; Dedet, J P

2005-01-01

The first identification of the Leishmania species responsible for visceral leishmaniasis in Djibouti is described. Four strains, obtained from three autochthonous cases, were identified by starch-gel electrophoresis and iso-enzyme analysis of 15 enzymatic systems. The strains were found to belong to two newly recognized zymodemes of L. donovani: MON-268 and MON-287.

Comparative study of structural models of Leishmania donovani and human GDP-mannose pyrophosphorylases.

PubMed

Daligaux, Pierre; Bernadat, Guillaume; Tran, Linh; Cavé, Christian; Loiseau, Philippe M; Pomel, Sébastien; Ha-Duong, Tâp

2016-01-01

Leishmania is the parasite responsible for the neglected disease leishmaniasis. Its virulence and survival require biosynthesis of glycoconjugates, whose guanosine diphospho-d-mannose pyrophosphorylase (GDP-MP) is a key player. However, experimentally resolved structures of this enzyme are still lacking. We herein propose structural models of the GDP-MP from human and Leishmania donovani. Based on a multiple sequences alignment, the models were built with MODELLER and then carefully refined with all atom molecular dynamics simulations in explicit solvent. Their quality was evaluated against several standard criteria, including their ability to bind GDP-mannose assessed by redocking calculations. Special attention was given in this study to interactions of the catalytic site residues with the enzyme substrate and competitive inhibitors, opening the perspective of medicinal chemistry developments. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Flavone-resistant Leishmania donovani Overexpresses LdMRP2 Transporter in the Parasite and Activates Host MRP2 on Macrophages to Circumvent the Flavone-mediated Cell Death*

PubMed Central

Chowdhury, Sayan; Mukhopadhyay, Rupkatha; Saha, Sourav; Mishra, Amartya; Sengupta, Souvik; Roy, Syamal; Majumder, Hemanta K.

2014-01-01

In parasites, ATP-binding cassette (ABC) transporters represent an important family of proteins related to drug resistance and other biological activities. Resistance of leishmanial parasites to therapeutic drugs continues to escalate in developing countries, and in many instances, it is due to overexpressed ABC efflux pumps. Progressively adapted baicalein (BLN)-resistant parasites (pB25R) show overexpression of a novel ABC transporter, which was classified as ABCC2 or Leishmania donovani multidrug resistance protein 2 (LdMRP2). The protein is primarily localized in the flagellar pocket region and in internal vesicles. Overexpressed LdABCC2 confers substantial BLN resistance to the parasites by rapid drug efflux. The BLN-resistant promastigotes when transformed into amastigotes in macrophage cells cannot be cured by treatment of macrophages with BLN. Amastigote resistance is concomitant with the overexpression of macrophage MRP2 transporter. Reporter analysis and site-directed mutagenesis assays demonstrated that antioxidant response element 1 is activated upon infection. The expression of this phase II detoxifying gene is regulated by NFE2-related factor 2 (Nrf2)-mediated antioxidant response element activation. In view of the fact that the signaling pathway of phosphoinositol 3-kinase controls microfilament rearrangement and translocation of actin-associated proteins, the current study correlates with the intricate pathway of phosphoinositol 3-kinase-mediated nuclear translocation of Nrf2, which activates MRP2 expression in macrophages upon infection by the parasites. In contrast, phalloidin, an agent that prevents depolymerization of actin filaments, inhibits Nrf2 translocation and Mrp2 gene activation by pB25R infection. Taken together, these results provide insight into the mechanisms by which resistant clinical isolates of L. donovani induce intracellular events relevant to drug resistance. PMID:24706751

Characterization of a ricin-resistant mutant of Leishmania donovani that expresses lipophosphoglycan.

PubMed

Phillips, Megan R; Turco, Salvatore J

2015-04-01

The abundant cell-surface lipophosphoglycan (LPG) of Leishmania parasites plays a central role throughout the eukaryote's life cycle. A number of LPG-defective mutants and their complementing genes have been isolated and have proven invaluable in assessing the importance of LPG and related glycoconjugates in parasite virulence. While ricin agglutination selection protocols frequently result in lpg- mutants, one  Leishmania donovani variant we isolated, named JABBA, was found to be lpg+. Procyclic (logarithmic) JABBA expresses significant amounts of a large-sized LPG, larger than observed from procyclic wild type but similar in size to LPG from wild type from metacyclic (stationary) phase. Structural analysis of the LPG from logarithmically grown JABBA by capillary electrophoresis protocols revealed that it averaged 30 repeat units composed of the unsubstituted Gal(β1,4)Man(α1)-PO4 typical of wild-type L. donovani. Analysis of JABBA LPG caps indicated that 20% is branched trisaccharide Gal(β1,4)[Glc(β1,2)]Man and tetrasaccharide Gal(β1,4)[Glc(β1,2)Man(α1,2)]Man instead of the usual Gal(β1,4)Man and Man(α1,2)Man terminating caps. Consistent with these structural observations, analyses of the relevant glycosyltransferases in JABBA microsomes involved in LPG biosynthesis showed a 2-fold increase in elongating mannosylphosphoryltransferase activity and up-regulation of a β-glucosyltransferase activity. Furthermore, the caps of JABBA LPG are cryptic in presentation as shown by the loss of binding by the lectins, ricin, peanut agglutinin and concanavalin A and reduced accessibility of the terminal galactose residues to oxidation by galactose oxidase. These results indicate that LPG from JABBA is intriguingly similar to the larger LPG in wild-type parasites that arises following the differentiation of the non-infectious procyclic promastigotes to infectious, metacyclic forms. © The Author 2014. Published by Oxford University Press. All rights reserved. For

Leishmania donovani Resistance to Miltefosine Involves a Defective Inward Translocation of the Drug

PubMed Central

Pérez-Victoria, F. Javier; Castanys, Santiago; Gamarro, Francisco

2003-01-01

Miltefosine (hexadecylphosphocholine [HePC]) is the first drug approved for the oral treatment of visceral leishmaniasis. As part of a study on the mechanisms of action of this drug and on the rates of resistance to this drug, we have been working in vitro with an Leishmania donovani line that was previously shown to be 15-fold more resistant to HePC. We have studied the accumulation of [14C]HePC by L. donovani promastigotes and have found a drastic reduction (>95%) in the ability of the resistant line to internalize the drug. Binding of HePC to the plasma membrane and drug efflux from preloaded cells were similar in both drug-sensitive and -resistant lines, and no [14C]HePC metabolism was evident in either line. Resistant parasites were also unable to take up other short-chain phospholipid analogs, independently of their polar head group, even though endocytosis remained unaltered. Finally, HePC uptake was temperature and energy dependent and sensitive to the thiol-reactive agent N-ethylmaleimide. We propose that inward translocation of a short-chain phospholipid across the plasma membrane may exist in Leishmania promastigotes and that such activity is defective in the resistant line. PMID:12878496

Leishmania donovani Utilize Sialic Acids for Binding and Phagocytosis in the Macrophages through Selective Utilization of Siglecs and Impair the Innate Immune Arm.

PubMed

Roy, Saptarshi; Mandal, Chitra

2016-08-01

Leishmania donovani, belonging to a unicellular protozoan parasite, display the differential level of linkage-specific sialic acids on their surface. Sialic acids binding immunoglobulin-like lectins (siglecs) are a class of membrane-bound receptors present in the haematopoetic cell lineages interact with the linkage-specific sialic acids. Here we aimed to explore the utilization of sialic acids by Leishmania donovani for siglec-mediated binding, phagocytosis, modulation of innate immune response and signaling pathways for establishment of successful infection in the host. We have found enhanced binding of high sialic acids containing virulent strains (AG83+Sias) with siglec-1 and siglec-5 present on macrophages compared to sialidase treated AG83+Sias (AG83-Sias) and low sialic acids-containing avirulent strain (UR6) by flow cytometry. This specific receptor-ligand interaction between sialic acids and siglecs were further confirmed by confocal microscopy. Sialic acids-siglec-1-mediated interaction of AG83+Sias with macrophages induced enhanced phagocytosis. Additionally, sialic acids-siglec-5 interaction demonstrated reduced ROS, NO generation and Th2 dominant cytokine response upon infection with AG83+Sias in contrast to AG83-Sias and UR6. Sialic acids-siglecs binding also facilitated multiplication of intracellular amastigotes. Moreover, AG83+Sias induced sialic acids-siglec-5-mediated upregulation of host phosphatase SHP-1. Such sialic acids-siglec interaction was responsible for further downregulation of MAPKs (p38, ERK and JNK) and PI3K/Akt pathways followed by the reduced translocation of p65 subunit of NF-κβ to the nucleus from cytosol in the downstream signaling pathways. This sequence of events was reversed in AG83-Sias and UR6-infected macrophages. Besides, siglec-knockdown macrophages also showed the reversal of AG83+Sias infection-induced effector functions and downstream signaling events. Taken together, this study demonstrated that virulent parasite

The Egyptian mongoose, Herpestes ichneumon, is a possible reservoir host of visceral leishmaniasis in eastern Sudan.

PubMed

Elnaiem, D A; Hassan, M M; Maingon, R; Nureldin, G H; Mekawi, A M; Miles, M; Ward, R D

2001-05-01

Investigations were made on possible reservoir hosts of Leishmania donovani in 2 zoonotic foci of visceral leishmaniasis (VL) in Dinder National Park (DNP) and the peri-domestic habitats of adjacent villages of eastern Sudan. Animals were captured, in November 1997-1998 and April-May 1999 and examined for L. donovani infection using light microscopy and 2 sensitive Polymerase Chain Reaction (PCR) systems. Microscopy and PCR investigations were also used to determine the infection rates of L. donovani in Phlebotomus orientalis captured from the uninhabited site of DNP. Infections of L. donovani were detected in 2 out of 14 Egyptian mongooses (Herpestes ichneumon), 1 out of 168 Arviconthus niloticus and 1 out of 8 Mastomys natalensis. Samples from 68 other animals captured from the study area were all negative for the infection. Active zoonotic transmission of L. donovani at the time of animal sampling in the uninhabited site of DNP was demonstrated by finding the parasite in 3.4% (7 out of 184) and 3.2% (5 out of 157) of flies collected in March 1998 and May 1999, respectively. We suggest that the Egyptian mongoose is a possible reservoir host of L. donovani. The importance of other animals in maintaining the infection is also discussed.

Molecular and Serological Evidence of Leishmania Infection in Stray Dogs from Visceral Leishmaniasis-Endemic Areas of Bangladesh.

PubMed

Akter, Shirin; Alam, Mohammad Zahangir; Nakao, Ryo; Yasin, Golam; Kato, Hirotomo; Katakura, Ken

2016-10-05

Visceral leishmaniasis (VL), or kala-azar, is mainly caused by two closely related Leishmania species, Leishmania infantum and Leishmania donovani Leishmania infantum is responsible for zoonotic VL, with dogs as the main reservoir host in the Mediterranean, the Middle East, Asia, and South America. In the Indian subcontinent, VL is caused by L. donovani and is considered anthroponotic, although the only known vector, the sand fly, is zoophilic in nature. The role of domestic and stray dogs in VL transmission is still unclear in this area. We screened 50 stray dogs from VL-endemic areas of Bangladesh for serological and molecular evidence of Leishmania infection. We detected anti-Leishmania antibodies in six (12%) dog serum samples using rK39 immunochromatographic tests. We observed Leishmania kinetoplast DNA in 10 (20%) buffy coat DNA samples by real-time polymerase chain reaction (PCR), five of which were positive based on internal transcribed spacer 1-PCR. A sequencing analysis of the amplified products confirmed that the parasitic DNA was derived from L. donovani Our findings support the hypothesis that stray dogs are an animal reservoir for L. donovani in this endemic region. Further studies are required to determine the precise role of dogs in the epidemiology of VL in Bangladesh. © The American Society of Tropical Medicine and Hygiene.

In vitro evaluation of newly synthesised [1,2,4]triazolo[1,5a]pyrimidine derivatives against Trypanosoma cruzi, Leishmania donovani and Phytomonas staheli.

PubMed

Luque, F; Fernández-Ramos, C; Entrala, E; Rosales, M J; Navarro, J A; Romero, M A; Salas, J M; Sánchez-Moreno, M

2000-05-01

The antiprotozoal activity of newly synthesised compounds, all [1,2,4]triazolo [1,5a]pyrimidine derivatives, was tested against the protozoan parasites Trypanosoma cruzi, Leishmania donovani and Phytotmonas staheli. Six of these compounds significantly inhibited in vitro cell growth of the epimastigote forms of T. cruzi, and the promastigote forms of L. donovani and P. staheli. Some of the compounds reached complete growth inhibition at 1 microg/ml for 48 h of parasite/drug interaction. None of the compounds tested showed significant toxicity against cells of Aedes albopictus, mouse macrophages J-774A.1 and Lycopersicum esculentum at dosages five times greater than used against parasites.

The lignan niranthin poisons Leishmania donovani topoisomerase IB and favours a Th1 immune response in mice

PubMed Central

Chowdhury, Sayan; Mukherjee, Tulika; Mukhopadhyay, Rupkatha; Mukherjee, Budhaditya; Sengupta, Souvik; Chattopadhyay, Sharmila; Jaisankar, Parasuraman; Roy, Syamal; Majumder, Hemanta K

2012-01-01

Niranthin, a lignan isolated from the aerial parts of the plant Phyllanthus amarus, exhibits a wide spectrum of pharmacological activities. In the present study, we have shown for the first time that niranthin is a potent anti-leishmanial agent. The compound induces topoisomerase I-mediated DNA–protein adduct formation inside Leishmania cells and triggers apoptosis by activation of cellular nucleases. We also show that niranthin inhibits the relaxation activity of heterodimeric type IB topoisomerase of L. donovani and acts as a non-competitive inhibitor interacting with both subunits of the enzyme. Niranthin interacts with DNA–protein binary complexes and thus stabilizes the ‘cleavable complex’ formation and subsequently inhibits the religation of cleaved strand. The compound inhibits the proliferation of Leishmania amastigotes in infected cultured murine macrophages with limited cytotoxicity to the host cells and is effective against antimony-resistant Leishmania parasites by modulating upregulated P-glycoprotein on host macrophages. Importantly, besides its in vitro efficacy, niranthin treatment leads to a switch from a Th2- to a Th1-type immune response in infected BALB/c mice. The immune response causes production of nitric oxide, which results in almost complete clearance of the liver and splenic parasite burden after intraperitoneal or intramuscular administration of the drug. These findings can be exploited to develop niranthin as a new drug candidate against drug-resistant leishmaniasis. PMID:23027614

The Potential Use of Forensic DNA Methods Applied to Sand Fly Blood Meal Analysis to Identify the Infection Reservoirs of Anthroponotic Visceral Leishmaniasis.

PubMed

Inbar, Ehud; Lawyer, Philip; Sacks, David; Podini, Daniele

2016-05-01

In the Indian sub-continent, visceral leishmaniasis (VL), also known as kala azar, is a fatal form of leishmaniasis caused by the kinetoplastid parasite Leishmania donovani and transmitted by the sand fly Phlebotomus argentipes. VL is prevalent in northeast India where it is believed to have an exclusive anthroponotic transmission cycle. There are four distinct cohorts of L. donovani exposed individuals who can potentially serve as infection reservoirs: patients with active disease, cured VL cases, patients with post kala azar dermal leishmaniasis (PKDL), and asymptomatic individuals. The relative contribution of each group to sustaining the transmission cycle of VL is not known. To answer this critical epidemiological question, we have addressed the feasibility of an approach that would use forensic DNA methods to recover human DNA profiles from the blood meals of infected sand flies that would then be matched to reference DNA sampled from individuals living or working in the vicinity of the sand fly collections. We found that the ability to obtain readable human DNA fingerprints from sand flies depended entirely on the size of the blood meal and the kinetics of its digestion. Useable profiles were obtained from most flies within the first 24 hours post blood meal (PBM), with a sharp decline at 48 hours and no readable profiles at 72 hours. This early time frame necessitated development of a sensitive, nested-PCR method compatible with detecting L. donovani within a fresh, 24 hours blood meal in flies fed on infected hamsters. Our findings establish the feasibility of the forensic DNA method to directly trace the human source of an infected blood meal, with constraints imposed by the requirement that the flies be recovered for analysis within 24 hours of their infective feed.

Anti-L. donovani activity in macrophage/amastigote model of palmarumycin CP18 and its large scale production.

PubMed

Ortega, Humberto E; Teixeira, Eliane de Morais; Rabello, Ana; Higginbotham, Sarah; Cubilla-Ríos, Luis

2014-01-01

Palmarumycin CP18, isolated from an extract of the fermentation broth and mycelium of the Panamanian endophytic fungus Edenia sp., was previously reported with strong and specific activity against Leishmania donovani. Here we report that when the same strain was cultured on different solid media--Harrold Agar, Leonian Agar, Potato dextrose Agar (PDA), Corn Meal Agar, Honey Peptone Agar, and eight vegetables (V8) Agar--in order to determine the optimal conditions for isolation of palmarumycin CP18, no signal for this compound was observed in any of the 1H NMR spectra of fractions obtained from these extracts. However, one extract, prepared from the fungal culture in PDA contained significant amounts of CJ-12,372, a possible biosynthetic precursor of palmarumycin CP18. Edenia sp. was cultivated on a large scale on PDA and CJ-12,372 was converted to palmarumycin CP18 by oxidation of its p-hydroquinone moiety with DDQ in dioxane. Palmarumycin CP18 showed anti-leishmanial activity against L. donovani in a macrophage/amastigote model, with IC50 values of 23.5 microM.

Leishmania infantum Asparagine Synthetase A Is Dispensable for Parasites Survival and Infectivity.

PubMed

Faria, Joana; Loureiro, Inês; Santarém, Nuno; Macedo-Ribeiro, Sandra; Tavares, Joana; Cordeiro-da-Silva, Anabela

2016-01-01

A growing interest in asparagine (Asn) metabolism has currently been observed in cancer and infection fields. Asparagine synthetase (AS) is responsible for the conversion of aspartate into Asn in an ATP-dependent manner, using ammonia or glutamine as a nitrogen source. There are two structurally distinct AS: the strictly ammonia dependent, type A, and the type B, which preferably uses glutamine. Absent in humans and present in trypanosomatids, AS-A was worthy of exploring as a potential drug target candidate. Appealingly, it was reported that AS-A was essential in Leishmania donovani, making it a promising drug target. In the work herein we demonstrate that Leishmania infantum AS-A, similarly to Trypanosoma spp. and L. donovani, is able to use both ammonia and glutamine as nitrogen donors. Moreover, we have successfully generated LiASA null mutants by targeted gene replacement in L. infantum, and these parasites do not display any significant growth or infectivity defect. Indeed, a severe impairment of in vitro growth was only observed when null mutants were cultured in asparagine limiting conditions. Altogether our results demonstrate that despite being important under asparagine limitation, LiAS-A is not essential for parasite survival, growth or infectivity in normal in vitro and in vivo conditions. Therefore we exclude AS-A as a suitable drug target against L. infantum parasites.

Pro-apoptotic effect of the landrace Bangla Mahoba of Piper betle on Leishmania donovani may be due to the high content of eugenol.

PubMed

Misra, Pragya; Kumar, Awanish; Khare, Prashant; Gupta, Swati; Kumar, Nikhil; Dube, Anuradha

2009-08-01

In the absence of effective and safe treatment for visceral leishmaniasis or Kala-azar - a devastating parasitic disease caused by Leishmania donovani - the search for anti-leishmanial agents from natural resources in common use is imperative. Recently, the comparative in vitro anti-leishmanial activity of methanolic extracts from two landraces of Piper betle - P. betle landrace Bangla Mahoba (PB-BM) and P. betle landrace Kapoori Vellaikodi (PB-KV) - has been reported. Here, the putative pathway responsible for death induced by the effective extract of PB-BM methanolic extract in promastigotes, as well as the intracellular amastigote form of L. donovani, was assessed using various biochemical approaches. It was found that PB-BM was capable of selectively inhibiting both stages of Leishmania parasites by accelerating apoptotic events by generation of reactive oxygen species targeting the mitochondria without any cytotoxicity towards macrophages. The study was extended to determine the presence or absence of activity of the methanolic extract of PB-BM and PB-KV on the basis of differences in essential oil composition present in the extract assessed by GC and MS. The essential oil from PB-BM was found to be rich in eugenol compared with that from PB-KV. The anti-leishmanial efficacy of PB-BM methanolic extract mediated through apoptosis is probably due to the higher content of eugenol in the active landrace. This observation emphasizes the need to extend studies related to traditional medicines from bioactive plants below the species level to the gender/landrace level for better efficacy and reproducibility.

Twin Attributes of Tyrosyl-tRNA Synthetase of Leishmania donovani: A HOUSEKEEPING PROTEIN TRANSLATION ENZYME AND A MIMIC OF HOST CHEMOKINE.

PubMed

Anand, Sneha; Madhubala, Rentala

2016-08-19

Aminoacyl-tRNA synthetases (aaRSs) are housekeeping enzymes essential for protein synthesis. Apart from their parent aminoacylation activity, several aaRSs perform non-canonical functions in diverse biological processes. The present study explores the twin attributes of Leishmania tyrosyl-tRNA synthetase (LdTyrRS) namely, aminoacylation, and as a mimic of host CXC chemokine. Leishmania donovani is a protozoan parasite. Its genome encodes a single copy of tyrosyl-tRNA synthetase. We first tested the canonical aminoacylation role of LdTyrRS. The recombinant protein was expressed, and its kinetic parameters were determined by aminoacylation assay. To study the physiological role of LdTyrRS in Leishmania, gene deletion mutations were attempted via targeted gene replacement. The heterozygous mutants showed slower growth kinetics and exhibited attenuated virulence. LdTyrRS appears to be an essential gene as the chromosomal null mutants did not survive. Our data also highlights the non-canonical function of L. donovani tyrosyl-tRNA synthetase. We show that LdTyrRS protein is present in the cytoplasm and exits from the parasite cytoplasm into the extracellular medium. The released LdTyrRS functions as a neutrophil chemoattractant. We further show that LdTyrRS specifically binds to host macrophages with its ELR (Glu-Leu-Arg) peptide motif. The ELR-CXCR2 receptor interaction mediates this binding. This interaction triggers enhanced secretion of the proinflammatory cytokines TNF-α and IL-6 by host macrophages. Our data indicates a possible immunomodulating role of LdTyrRS in Leishmania infection. This study provides a platform to explore LdTyrRS as a potential target for drug development. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Leishmania donovani tyrosyl-tRNA synthetase structure in complex with a tyrosyl adenylate analog and comparisons with human and protozoan counterparts.

PubMed

Barros-Álvarez, Ximena; Kerchner, Keshia M; Koh, Cho Yeow; Turley, Stewart; Pardon, Els; Steyaert, Jan; Ranade, Ranae M; Gillespie, J Robert; Zhang, Zhongsheng; Verlinde, Christophe L M J; Fan, Erkang; Buckner, Frederick S; Hol, Wim G J

2017-07-01

The crystal structure of Leishmania donovani tyrosyl-tRNA synthetase (LdTyrRS) in complex with a nanobody and the tyrosyl adenylate analog TyrSA was determined at 2.75 Å resolution. Nanobodies are the variable domains of camelid heavy chain-only antibodies. The nanobody makes numerous crystal contacts and in addition reduces the flexibility of a loop of LdTyrRS. TyrSA is engaged in many interactions with active site residues occupying the tyrosine and adenine binding pockets. The LdTyrRS polypeptide chain consists of two pseudo-monomers, each consisting of two domains. Comparing the two independent chains in the asymmetric unit reveals that the two pseudo-monomers of LdTyrRS can bend with respect to each other essentially as rigid bodies. This flexibility might be useful in the positioning of tRNA for catalysis since both pseudo-monomers in the LdTyrRS chain are needed for charging tRNA Tyr . An "extra pocket" (EP) appears to be present near the adenine binding region of LdTyrRS. Since this pocket is absent in the two human homologous enzymes, the EP provides interesting opportunities for obtaining selective drugs for treating infections caused by L. donovani, a unicellular parasite causing visceral leishmaniasis, or kala azar, which claims 20,000 to 30,000 deaths per year. Sequence and structural comparisons indicate that the EP is a characteristic which also occurs in the active site of several other important pathogenic protozoa. Therefore, the structure of LdTyrRS could inspire the design of compounds useful for treating several different parasitic diseases. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Immunotherapy against visceral leishmaniasis with the nucleoside hydrolase-DNA vaccine of Leishmania donovani.

PubMed

Gamboa-León, R; Paraguai de Souza, E; Borja-Cabrera, G P; Santos, F N; Myashiro, L M; Pinheiro, R O; Dumonteil, E; Palatnik-de-Sousa, C B

2006-05-29

The nucleoside hydrolase (NH36) of Leishmania (L.) donovani is a vital enzyme which releases purines or pyrimidines of foreign DNA to be used in the synthesis of parasite DNA. As a bivalent DNA vaccine, the VR1012-NH36 was immunoprotective against visceral and cutaneous murine leishmaniasis. In this work we tested the immunotherapy against Leishmania (L.) chagasi infection, using two doses of 100 or 20 microg VR1012-NH36 vaccine (i.m. route), and, as a possible immunomodulator, aqueous garlic extract (8 mg/kg/day by the i.p. route), which was effective in immunotherapy of cutaneous murine leishmaniasis. Liver parasitic load was significantly reduced following treatment with 100 microg (91%) and 20 microg (77%) of the DNA vaccine, and by 20 microg DNA vaccine and garlic extract (76%) (p=0.023). Survival was 33% for saline controls, 100% for the 100 microg vaccine, and 83 and 67% for the 20 microg vaccine with and without garlic extract addition, respectively. Garlic treatment alone did not reduce parasite load (p>0.05), but increased survival (100%). The NH36-DNA vaccine was highly effective as a new tool for the therapy and control of visceral leishmaniasis, while the mild protective effect of garlic might be related to an unspecific enhancement of IFN-gamma secretion.

Inactivation of Leishmania donovani infantum and Trypanosoma cruzi in red cell suspensions with thiazole orange.

PubMed

Wagner, Stephen J; Skripchenko, Andrey; Salata, Jeanne; O'Sullivan, Anne Marie; Cardo, Lisa J

2008-07-01

Methods for pathogen inactivation are currently available in some European countries for treatment of plasma and platelet (PLT) components; no approved method for treatment of red cells (RBCs) or whole blood is ready for implementation. In a previous study, thiazole orange (TO), a dye commonly used to count reticulated RBCs and PLTs, exhibited potent photoactivity against human immunodeficiency virus-1 and several model viruses in RBC suspensions. The aim of this study is to further evaluate the ability of TO to inactivate pathogens by measuring its activity against the protozoa Leishmania donovani infantum and Trypanosoma cruzi. RBC suspensions were deliberately contaminated with L. donovani infantum promastigotes or T. cruzi trypomastigotes and either maintained as an untreated control, incubated with 80 mumol per L TO in the dark, or treated with TO and light. Control and treated samples were inoculated into medium and subsequently microscopically examined for growth. No growth was observed in samples treated with TO in the presence or absence of light, while matched control samples lacking TO and diluted up to 5 log consistently demonstrated Leishmania or T. cruzi growth (n = 3). TO inactivated Leishmania or T. cruzi to the limit of detection in RBC suspensions without intentional illumination.

Glycyrrhizic acid attenuates growth of Leishmania donovani by depleting ergosterol levels.

PubMed

Dinesh, Neeradi; Neelagiri, Soumya; Kumar, Vinay; Singh, Sushma

2017-05-01

In the present study, glycyrrhizic acid (GA) the main component of Glycyrrhiza glabra was evaluated for its efficacy as antileishmanial agent and its mode of action explored. GA inhibits promastigotes and intracellular amastigotes in a dose dependent manner at an IC 50 value of 34 ± 3.0 μM and 20 ± 4.2 μM respectively. GA was non-toxic against THP-1 macrophage host cell line. GA was found to inhibit recombinant Leishmania donovani HMG-CoA reductase (LdHMGR) enzyme at the half-maximum inhibitory concentration of 24 ± 4.3 μM indicating the sensitivity and specificity of GA towards the enzyme. However, GA could cause only 30% reduction in HMGR activity when measured in Leishmania promastigotes treated with 34 μM of GA. Interestingly western blot analysis revealed fivefold reduced HMGR expression in GLA treated promastigotes. To further study the mode of action of GA, we used transgenic parasites overexpressing LdHMGR. Results indicated that ∼2 fold resistance was exhibited by LdHMGR overexpressing promastigotes to GA with an IC 50 value of 74 μM compared to the wild type parasite. This explained the specific binding of GA to LdHMGR enzyme. There was ∼2 fold depletion in ergosterol levels in wild type promastigotes compared to the HMGR overexpressors. This data was further validated by exogenous supplementation of GA treated cells with ergosterol and 40% reversal of growth inhibition was observed. The results obtained suggested that GA kills the parasite by affecting sterol biosynthetic pathway, especially by inhibiting the L. donovani HMGR and altering ergosterol levels. The finding from the current study shows that GA is a potential antileishmanial chemotherapeutic agent. Copyright © 2017 Elsevier Inc. All rights reserved.

Th1-stimulatory polyproteins of soluble Leishmania donovani promastigotes ranging from 89.9 to 97.1 kDa offers long-lasting protection against experimental visceral leishmaniasis.

PubMed

Kumari, Shraddha; Samant, Mukesh; Misra, Pragya; Khare, Prashant; Sisodia, Brijesh; Shasany, Ajit K; Dube, Anuradha

2008-10-23

Our earlier studies identified a fraction (F2) of Leishmania donovani soluble promastigote antigen belonging to 97.4-68 kDa for its ability to stimulate Th1-type cellular responses in cured visceral leishmaniasis (VL) patients as well as in cured hamsters. A further fractionation of F2-fraction into seven subfractions (F2.1-F2.7) and re-assessment for their immunostimulatory responses revealed that out of these, only four (F2.4-F2.7) belonging to 89.9-97.1 kDa, stimulated remarkable Th1-type cellular responses either individually or in a pooled form (P4-7). In this study these potential subfractions were further assessed for their prophylactic potential in combination with BCG against L. donovani challenge in hamsters. Optimum parasite inhibition ( approximately 99%) was obtained in hamsters vaccinated with pooled subfractions and they survived for 1 year. The protection was further supported by remarkable lymphoproliferative, IFN-gamma and IL-12 responses along with profound delayed type hypersensitivity and increased levels of Leishmania-specific IgG2 antibody as observed on days 45, 90 and 120 post-challenge suggesting that a successful subunit vaccine against VL may require multiple Th1-immunostimulatory proteins. MALDI-TOF-MS/MS analysis of these subfractions further revealed that of the 19 identified immunostimulatory proteins, Elongation factor-2, p45, Heat shock protein-70/83, Aldolase, Enolase, Triosephosphate isomerase, Disulfideisomerase and Calreticulin were the major ones in these subfractions.

A Novel Spirooxindole Derivative Inhibits the Growth of Leishmania donovani Parasites both In Vitro and In Vivo by Targeting Type IB Topoisomerase

PubMed Central

Saha, Sourav; Acharya, Chiranjit; Pal, Uttam; Chowdhury, Somenath Roy; Sarkar, Kahini; Maiti, Nakul C.

2016-01-01

Visceral leishmaniasis is a fatal parasitic disease, and there is an emergent need for development of effective drugs against this neglected tropical disease. We report here the development of a novel spirooxindole derivative, N-benzyl-2,2′α-3,3′,5′,6′,7′,7α,α′-octahydro-2methoxycarbonyl-spiro[indole-3,3′-pyrrolizidine]-2-one (compound 4c), which inhibits Leishmania donovani topoisomerase IB (LdTopIB) and kills the wild type as well as drug-resistant parasite strains. This compound inhibits catalytic activity of LdTopIB in a competitive manner. Unlike camptothecin (CPT), the compound does not stabilize the DNA-topoisomerase IB cleavage complex; rather, it hinders drug-DNA-enzyme covalent complex formation. Fluorescence studies show that the stoichiometry of this compound binding to LdTopIB is 2:1 (mole/mole), with a dissociation constant of 6.65 μM. Molecular docking with LdTopIB using the stereoisomers of compound 4c produced two probable hits for the binding site, one in the small subunit and the other in the hinge region of the large subunit of LdTopIB. This spirooxindole is highly cytotoxic to promastigotes of L. donovani and also induces apoptosis-like cell death in the parasite. Treatment with compound 4c causes depolarization of mitochondrial membrane potential, formation of reactive oxygen species inside parasites, and ultimately fragmentation of nuclear DNA. Compound 4c also effectively clears amastigote forms of wild-type and drug-resistant parasites from infected mouse peritoneal macrophages but has less of an effect on host macrophages. Moreover, compound 4c showed strong antileishmanial efficacies in the BALB/c mouse model of leishmaniasis. This compound potentially can be used as a lead for developing excellent antileishmanial agents against emerging drug-resistant strains of the parasite. PMID:27503653

Understanding the transmission dynamics of Leishmania donovani to provide robust evidence for interventions to eliminate visceral leishmaniasis in Bihar, India

USDA-ARS?s Scientific Manuscript database

Molecular tools enable the collection of accurate estimates of human blood index (HBI) in Phlebotomus argentipes. The refinement of a metacyclic-specific qPCR assay to identify L. donovani in P. argentipes would enable quantification of the entomological inoculation rate (EIR) for the first time. Li...

Understanding the transmission dynamics of Leishmania donovani to provide robust evidence for interventions to eliminate visceral leishmaniasis in Bihar, India

USDA-ARS?s Scientific Manuscript database

Molecular tools enable the collection of accurate estimates of human blood index (HBI) in P. argentipes. The refinement of a metacyclic-specific qPCR assay to identify L. donovani in P. argentipes would enable quantification of the entomological inoculation rate (EIR) for the first time. Likewise, a...

Live Attenuated Leishmania donovani Centrin Gene-Deleted Parasites Induce IL-23-Dependent IL-17-Protective Immune Response against Visceral Leishmaniasis in a Murine Model.

PubMed

Banerjee, Antara; Bhattacharya, Parna; Dagur, Pradeep K; Karmakar, Subir; Ismail, Nevien; Joshi, Amritanshu B; Akue, Adovi D; KuKuruga, Mark; McCoy, John Philip; Dey, Ranadhir; Nakhasi, Hira L

2018-01-01

No vaccine exists against visceral leishmaniasis. To develop effective vaccines, we have previously reported protective role of live attenuated centrin gene-deleted Leishmania donovani ( LdCen -/- ) parasites through induction of Th1 type immune response in mice, hamsters, and dogs. In this study, we specifically explored the role of Th17 cells in LdCen -/- -induced host protection in mice. Our results showed that compared with wild-type L. donovani infection, LdCen -/- parasites induce significantly higher expression of Th17 differentiation cytokines in splenic dendritic cells. There was also induction of IL-17 and its promoting cytokines in total splenocytes and in both CD4 and CD8 T cells following immunization with LdCen -/- Upon challenge with wild-type parasites, IL-17 and its differentiating cytokines were significantly higher in LdCen -/- -immunized mice compared with nonimmunized mice that resulted in parasite control. Alongside IL-17 induction, we observed induction of IFN-γ-producing Th1 cells as reported earlier. However, Th17 cells are generated before Th1 cells. Neutralization of either IL-17 or IFN-γ abrogated LdCen -/- -induced host protection further confirming the essential role of Th17 along with Th1 cytokines in host protection. Treatment with recombinant IL-23, which is required for stabilization and maintenance of IL-17, heightened Th17, and Tc17 responses in immunized mice splenocytes. In contrast, Th17 response was absent in immunized IL-23R -/- mice that failed to induce protection upon virulent Leishmania challenge suggesting that IL-23 plays an essential role in IL-17-mediated protection by LdCen -/- parasites. This study unveiled the role of IL-23-dependent IL-17 induction in LdCen -/- parasite-induced immunity and subsequent protection against visceral leishmaniasis.

Identification of a Surrogate Marker for Infection in the African Green Monkey Model of Inhalation Anthrax

DTIC Science & Technology

2008-12-01

as well as condition and clarity of eyes and nose; clinical signs included breathing rate and pattern; natural behavior included peer interaction ...human cases, fatigue and/or mal- aise was a presenting symptom in only 64% of cases (26). While decreased activity and interaction were noted in some...experimental infection with Leishmania leishmania donovani and Leishmania leishmania infantum. Lab. Anim. Sci. 43:37–47. 5. Brachman, P. S. 1980

In vitro 4-Aryloxy-7-chloroquinoline derivatives are effective in mono- and combined therapy against Leishmania donovani and induce mitocondrial membrane potential disruption.

PubMed

Valdivieso, Elizabeth; Mejías, Fabiola; Torrealba, Carlos; Benaim, Gustavo; Kouznetsov, Vladimir V; Sojo, Felipe; Rojas-Ruiz, Fernando A; Arvelo, Francisco; Dagger, Francehuli

2018-07-01

The present study evaluates in vitro the effect of two synthetic compounds of the 7-chloro-4-aryloxyquinoline series, QI (C 17 H 12 ClNO 3 ) and QII (C 18 H 15 ClN 4 O 2 S), on Leishmania donovani parasites. The results obtained demonstrate that these compounds are able to inhibit the proliferation of L. donovani promastigotes in a dose-dependent way (QI IC 50  = 13.03 ± 3.4 and QII IC 50  = 7.90 ± 0.6 μM). Likewise, these compounds significantly reduced the percentage of macrophage infection by amastigotesand the number of amastigotes within macrophage phagolysosomes, the clinical relevant phase of these parasites. Compound QI showed an IC 50 value of 0.66 ± 0.2 μM, while for derivative QII, the corresponding IC 50 was 1.02 ± 0.17 μM. Interestingly, the amastigotes were more susceptible to the drug treatment when compared to promastigotes. Furthermore, no cytotoxic effect of these compounds was observed on the macrophage cell line at the concentrations tested. The combination of these compounds with miltefosine and amphotericin B on both parasite morphotypes was evaluated. The isobolograms showed a synergistic effect for both combinations; with a Fractional Inhibitory Concentration (FIC) Index lower than 1 for promastigotes and less than 0.3 for intracellular amastigotes. The effect of QI and QII on mitochondrial membrane potential was also studied. The combination of quinolone derivatives compounds with miltefosine and amphotericin B showed 5-8-fold stronger depolarization of membrane mitochondrial potential when compared to drugs alone. The present work validates the combination of drugs as an effective alternative to potentiate the action of anti-Leishmania agents and points to the quinoline compounds studied here as possible leishmanicidal drugs. Copyright © 2018 Elsevier B.V. All rights reserved.

TRANSCRIPTIONAL INHIBITION OF INTERLEUKIN-12 PROMOTER ACTIVITY IN LEISHMANIA SPP.-INFECTED MACROPHAGES

PubMed Central

Jayakumar, Asha; Widenmaier, Robyn; Ma, Xiaojing; McDowell, Mary Ann

2009-01-01

To establish and persist within a host, Leishmania spp. parasites delay the onset of cell-mediated immunity by suppressing interleukin-12 (IL-12) production from host macrophages. Although it is established that Leishmania spp.-infected macrophages have impaired IL-12 production, the mechanisms that account for this suppression remain to be completely elucidated. Using a luciferase reporter assay assessing IL-12 transcription, we report here that Leishmania major, Leishmania donovani, and Leishmania chagasi inhibit IL-12 transcription in response to interferon-gamma, lipopolysaccharide, and CD40 ligand and that Leishmania spp. lipophosphoglycan, phosphoglycans, and major surface protein are not necessary for inhibition. In addition, all the Leishmania spp. strains and life-cycle stages tested inhibited IL-12 promoter activity. Our data further reveal that autocrine-acting host factors play no role in the inhibitory response and that phagocytosis signaling is necessary for inhibition of IL-12. PMID:18372625

Characterization of dipeptidylcarboxypeptidase of Leishmania donovani: a molecular model for structure based design of antileishmanials

NASA Astrophysics Data System (ADS)

Baig, Mirza Saqib; Kumar, Ashutosh; Siddiqi, Mohammad Imran; Goyal, Neena

2010-01-01

Leishmania donovani dipeptidylcarboxypeptidsae (LdDCP), an angiotensin converting enzyme (ACE) related metallopeptidase has been identified and characterized as a putative drug target for antileishmanial chemotherapy. The kinetic parameters for LdDCP with substrate, Hip-His-Leu were determined as, Km, 4 mM and Vmax, 1.173 μmole/ml/min. Inhibition studies revealed that known ACE inhibitors (captopril and bradykinin potentiating peptide; BPP1) were weak inhibitors for LdDCP as compared to human testicular ACE (htACE) with Ki values of 35.8 nM and 3.9 μM, respectively. Three dimensional model of LdDCP was generated based on crystal structure of Escherichia coli DCP (EcDCP) by means of comparative modeling and assessed using PROSAII, PROCHECK and WHATIF. Captopril docking with htACE, LdDCP and EcDCP and analysis of molecular electrostatic potentials (MEP) suggested that the active site domain of three enzymes has several minor but potentially important structural differences. These differences could be exploited for designing selective inhibitor of LdDCP thereby antileishmanial compounds either by denovo drug design or virtual screening of small molecule databases.

Leishmania donovani amastigote component-induced colony-stimulating factor production by macrophages: modulation by morphine.

PubMed

Singal, Priya; Singh, Prati Pal

2005-02-01

The neuroimmunomodulatory effects of opiates during microbial infections are now well known; however, not much is known during leishmaniasis. Here, we report the effects of morphine on purified approximately 12-kDa component of Leishmania donovani amastigote antigen (LDAA-12)-induced colony-stimulating factor (CSF) production by mouse peritoneal macrophages (PMs) in vitro. Low concentrations (1 x 10(-9) and 1 x 10(-11) M) of morphine significantly (P < 0.05) augmented the production of CSFs, whereas high concentrations (1 x 10(-3) and 1 x 10(-5) M) inhibited CSF production. Morphine exerted a similar concentration-dependent biphasic effect on the LDAA-12-induced elaboration of granulocyte (G)-macrophage (M)-CSF (GM-CSF) and M-CSF by PMs in their conditioned medium, as quantified by using enzyme-linked immunosorbent assay. Furthermore, selective agonists of mu-(DAGO) and delta-(DPDPE) opioid receptors also, respectively, augmented and inhibited the production of CSFs. Pretreatment of PMs with naloxone (1 x 10(-5) M) significantly (P < 0.05) blocked the augmenting effect of morphine. In contrast, at 1 x 10(-5) M, naloxone lacked any effect on the inhibitory effect of morphine; however, its 100-fold higher concentration partially blocked it. This study, apparently for the first time, demonstrates that morphine, via surface opioid receptors, biphasically modulates the LDAA-12-induced CSF production by PMs, in vitro. These results thus show the implications of opiate abuse on the outcome of therapeutic interventions in areas where both visceral leishmaniasis and drug abuse are rampant.

A Chimera Containing CD4+ and CD8+ T-Cell Epitopes of the Leishmania donovani Nucleoside Hydrolase (NH36) Optimizes Cross-Protection against Leishmania amazonesis Infection.

PubMed

Alves-Silva, Marcus Vinícius; Nico, Dirlei; Morrot, Alexandre; Palatnik, Marcos; Palatnik-de-Sousa, Clarisa B

2017-01-01

The Leishmania donovani nucleoside hydrolase (NH36) and NH A34480 of Leishmania amazonensis share 93% of sequence identity. In mice, the NH36 induced protection against visceral leishmaniasis is mediated by a CD4+ T cell response against its C-terminal domain (F3). Besides this CD4+ Th1 response, prevention and cure of L. amazonensis infection require also additional CD8+ and regulatory T-cell responses to the NH36 N-terminal (F1 domain). We investigated if mice vaccination with F1 and F3 domains cloned in tandem, in a recombinant chimera, with saponin, optimizes the vaccine efficacy against L. amazonensis infection above the levels promoted by the two admixed domains or by each domain independently. The chimera induced the highest IgA, IgG, and IgG2a anti-NH36 antibody, IDR, IFN-γ, and IL-10 responses, while TNF-α was more secreted by mice vaccinated with F3 or all F3-contaning vaccines. Additionally, the chimera and the F1 vaccine also induced the highest proportions of CD4+ and CD8+ T cells secreting IL-2, TNF-α, or IFN-γ alone, TNF-α in combination with IL-2 or IFN-γ, and of CD4+ multifunctional cells secreting IL-2, TNF-α, and IFN-γ. Correlating with the immunological results, the strongest reductions of skin lesions sizes were determined by the admixed domains (80%) and by the chimera (84%), which also promoted the most pronounced and significant reduction of the parasite load (99.8%). Thus, the epitope presentation in a recombinant chimera optimizes immunogenicity and efficacy above the levels induced by the independent or admixed F1 and F3 domains. The multiparameter analysis disclosed that the Th1-CD4+ T helper response induced by the chimera is mainly directed against its FRYPRPKHCHTQVA epitope. Additionally, the YPPEFKTKL epitope of F1 induced the second most important CD4+ T cell response, and, followed by the DVAGIVGVPVAAGCT, FMLQILDFYTKVYE, and ELLAITTVVGNQ sequences, also the most potent CD8+ T cell responses and IL-10 secretion. Remarkably

A Chimera Containing CD4+ and CD8+ T-Cell Epitopes of the Leishmania donovani Nucleoside Hydrolase (NH36) Optimizes Cross-Protection against Leishmania amazonesis Infection

PubMed Central

Alves-Silva, Marcus Vinícius; Nico, Dirlei; Morrot, Alexandre; Palatnik, Marcos; Palatnik-de-Sousa, Clarisa B.

2017-01-01

The Leishmania donovani nucleoside hydrolase (NH36) and NH A34480 of Leishmania amazonensis share 93% of sequence identity. In mice, the NH36 induced protection against visceral leishmaniasis is mediated by a CD4+ T cell response against its C-terminal domain (F3). Besides this CD4+ Th1 response, prevention and cure of L. amazonensis infection require also additional CD8+ and regulatory T-cell responses to the NH36 N-terminal (F1 domain). We investigated if mice vaccination with F1 and F3 domains cloned in tandem, in a recombinant chimera, with saponin, optimizes the vaccine efficacy against L. amazonensis infection above the levels promoted by the two admixed domains or by each domain independently. The chimera induced the highest IgA, IgG, and IgG2a anti-NH36 antibody, IDR, IFN-γ, and IL-10 responses, while TNF-α was more secreted by mice vaccinated with F3 or all F3-contaning vaccines. Additionally, the chimera and the F1 vaccine also induced the highest proportions of CD4+ and CD8+ T cells secreting IL-2, TNF-α, or IFN-γ alone, TNF-α in combination with IL-2 or IFN-γ, and of CD4+ multifunctional cells secreting IL-2, TNF-α, and IFN-γ. Correlating with the immunological results, the strongest reductions of skin lesions sizes were determined by the admixed domains (80%) and by the chimera (84%), which also promoted the most pronounced and significant reduction of the parasite load (99.8%). Thus, the epitope presentation in a recombinant chimera optimizes immunogenicity and efficacy above the levels induced by the independent or admixed F1 and F3 domains. The multiparameter analysis disclosed that the Th1-CD4+ T helper response induced by the chimera is mainly directed against its FRYPRPKHCHTQVA epitope. Additionally, the YPPEFKTKL epitope of F1 induced the second most important CD4+ T cell response, and, followed by the DVAGIVGVPVAAGCT, FMLQILDFYTKVYE, and ELLAITTVVGNQ sequences, also the most potent CD8+ T cell responses and IL-10 secretion. Remarkably

AMP-acetyl CoA synthetase from Leishmania donovani: identification and functional analysis of 'PX4GK' motif.

PubMed

Soumya, Neelagiri; Kumar, I Sravan; Shivaprasad, S; Gorakh, Landage Nitin; Dinesh, Neeradi; Swamy, Kayala Kambagiri; Singh, Sushma

2015-04-01

An adenosine monophosphate forming acetyl CoA synthetase (AceCS) which is the key enzyme involved in the conversion of acetate to acetyl CoA has been identified from Leishmania donovani for the first time. Sequence analysis of L. donovani AceCS (LdAceCS) revealed the presence of a 'PX4GK' motif which is highly conserved throughout organisms with higher sequence identity (96%) to lower sequence identity (38%). A ∼ 77 kDa heterologous protein with C-terminal 6X His-tag was expressed in Escherichia coli. Expression of LdAceCS in promastigotes was confirmed by western blot and RT-PCR analysis. Immunolocalization studies revealed that it is a cytosolic protein. We also report the kinetic characterization of recombinant LdAceCS with acetate, adenosine 5'-triphosphate, coenzyme A and propionate as substrates. Site directed mutagenesis of residues in conserved PX4GK motif of LdAceCS was performed to gain insight into its potential role in substrate binding, catalysis and its role in maintaining structural integrity of the protein. P646A, G651A and K652R exhibited more than 90% loss in activity signifying its indispensible role in the enzyme activity. Substitution of other residues in this motif resulted in altered substrate specificity and catalysis. However, none of them had any role in modulation of the secondary structure of the protein except G651A mutant. Copyright © 2015 Elsevier B.V. All rights reserved.

The Hsp90-Sti1 interaction is critical for Leishmania donovani proliferation in both life cycle stages.

PubMed

Hombach, Antje; Ommen, Gabi; Chrobak, Mareike; Clos, Joachim

2013-04-01

The heat shock protein 90 plays a pivotal role in the life cycle control of Leishmania donovani promoting the fast-growing insect stage of this parasite. Equally important for insect stage growth is the co-chaperone Sti1. We show that replacement of Sti1 is only feasible in the presence of additional Sti1 transgenes indicating an essential role. To better understand the impact of Sti1 and its interaction with Hsp90, we performed a mutational analysis of Hsp90. We established that a single amino acid exchange in the Leishmania Hsp90 renders that protein resistant to the inhibitor radicicol (RAD), yet does not interfere with its functionality. Based on this RAD-resistant Hsp90, we established a combined chemical knockout/gene complementation (CKC) approach. We can show that Hsp90 function is required in both insect and mammalian life stages and that the Sti1-binding motif of Hsp90 is crucial for proliferation of insect and mammalian stages of the parasite. The Sti1-binding motif in Leishmania Hsp90 is suboptimal - optimizing the motif increased initial intracellular proliferation underscoring the importance of the Hsp90-Sti1 interaction for this important parasitic protozoan. The CKC strategy we developed will allow the future analysis of more Hsp90 domains and motifs in parasite viability and infectivity. © 2012 Blackwell Publishing Ltd.

Ascorbate Peroxidase, a Key Molecule Regulating Amphotericin B Resistance in Clinical Isolates of Leishmania donovani

PubMed Central

Kumar, Ashish; Das, Sushmita; Purkait, Bidyut; Sardar, Abul Hasan; Ghosh, Ayan Kumar; Dikhit, Manas Ranjan; Abhishek, Kumar

2014-01-01

Amphotericin B (AmB), a polyene macrolide, is now a first-line treatment of visceral leishmaniasis cases refractory to antimonials in India. AmB relapse cases and the emergence of secondary resistance have now been reported. To understand the mechanism of AmB, differentially expressed genes in AmB resistance strains were identified by a DNA microarray and real-time reverse transcriptase PCR (RT-PCR) approach. Of the many genes functionally overexpressed in the presence of AmB, the ascorbate peroxidase gene from a resistant Leishmania donovani strain (LdAPx gene) was selected because the gene is present only in Leishmania, not in humans. Apoptosis-like cell death after exposure to AmB was investigated in a wild-type (WT) strain in which the LdAPx gene was overexpressed and in AmB-sensitive and -resistant strains. A higher percentage of apoptosis-like cell death after AmB treatment was noticed in the sensitive strain than in both the resistant isolate and the strain sensitive to LdAPx overexpression. This event is preceded by AmB-induced formation of reactive oxygen species and elevation of the cytosolic calcium level. Enhanced cytosolic calcium was found to be responsible for depolarization of the mitochondrial membrane potential and the release of cytochrome c (Cyt c) into the cytosol. The redox behavior of Cyt c showed that it has a role in the regulation of apoptosis-like cell death by activating metacaspase- and caspase-like proteins and causing concomitant nuclear alterations, as determined by terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) and DNA fragmentation in the resistant strain. The present study suggests that constitutive overexpression of LdAPx in the L. donovani AmB-resistant strain prevents cells from the deleterious effect of oxidative stress, i.e., mitochondrial dysfunction and cellular death induced by AmB. PMID:25114128

Apoptosis-like death in Leishmania donovani promastigotes induced by eugenol-rich oil of Syzygium aromaticum.

PubMed

Islamuddin, Mohammad; Sahal, Dinkar; Afrin, Farhat

2014-01-01

Leishmaniasis consists of a complex spectrum of infectious diseases with worldwide distribution of which visceral leishmaniasis or kala-azar caused by Leishmania donovani is the most devastating. In the absence of vaccines, chemotherapy remains the mainstay for the control of leishmaniasis. The drugs of choice are expensive and associated with multiple adverse side effects. Because of these limitations, the development of new antileishmanial compounds is imperative and plants offer prospects in this regard. The present work was conducted to study the antileishmanial potential of oil from Syzygium aromaticum flower buds (clove). The S. aromaticum oil was characterized by gas chromatography and GC-MS and eugenol as well as eugenyl acetate were found to be the most abundant compounds, composing 59.75 % and 29.24 %, respectively of the oil. Our findings have shown that eugenol-rich essential oil from S. aromaticum (EROSA) possesses significant activity against L. donovani, with 50 % inhibitory concentration of 21 ± 0.16 µg ml(-1) and 15.24 ± 0.14 µg ml(-1), respectively, against promastigotes and intracellular amastigotes. Alterations in cellular morphology and growth reversibility assay substantiated the leishmanicidal activity of EROSA. The leishmanicidal effect was mediated via apoptosis as confirmed by externalization of phosphatidylserine, DNA nicking by TdT-mediated dUTP nick-end labelling (TUNEL) assay, dyskinetoplastidy, cell cycle arrest at sub-G0-G1 phase, loss of mitochondrial membrane potential and reactive oxygen species generation. EROSA presented no adverse cytotoxic effects against murine macrophages even at 200 µg ml(-1). Our studies authenticate the promising antileishmanial activity of EROSA, which is mediated by programmed cell death, and, accordingly, EROSA may be a source of novel agents for the treatment of leishmaniasis.

An insight into the active site of a type I DNA topoisomerase from the kinetoplastid protozoan Leishmania donovani

PubMed Central

Das, Aditi; Mandal, Chhabinath; Dasgupta, Arindam; Sengupta, Tanushri; Majumder, Hemanta K.

2002-01-01

DNA topoisomerases are ubiquitous enzymes that govern the topological interconversions of DNA thereby playing a key role in many aspects of nucleic acid metabolism. Recently determined crystal structures of topoisomerase fragments, representing nearly all the known subclasses, have been solved. The type IB enzymes are structurally distinct from other known topoisomerases but are similar to a class of enzymes referred to as tyrosine recombinases. A putative topoisomerase I open reading frame from the kinetoplastid Leishmania donovani was reported which shared a substantial degree of homology with type IB topoisomerases but having a variable C-terminus. Here we present a molecular model of the above parasite gene product, using the human topoisomerase I crystal structure in complex with a 22 bp oligonucleotide as a template. Our studies indicate that the overall structure of the parasite protein is similar to the human enzyme; however, major differences occur in the C-terminal loop, which harbors a serine in place of the usual catalytic tyrosine. Most other structural themes common to type IB topoisomerases, including secondary structural folds, hinged clamps that open and close to bind DNA, nucleophilic attack on the scissile DNA strand and formation of a ternary complex with the topoisomerase I inhibitor camptothecin could be visualized in our homology model. The validity of serine acting as the nucleophile in the case of the parasite protein model was corroborated with our biochemical mapping of the active site with topoisomerase I enzyme purified from L.donovani promastigotes. PMID:11809893

Increased expression of LD1 genes transcribed by RNA polymerase I in Leishmania donovani as a result of duplication into the rRNA gene locus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lodes, M.J.; Merlin, G.; DeVos, T.

1995-12-01

This report investigates the duplication of two LD1 genes into the rRNA locus and the resultant transcription by RNA polymerase I, which has a faster transcription rate than that of RNA polymerase II. This was conducted using a 2.2-Mb chromosome in Leishmania donovani. 55 refs., 6 figs.

An orally effective dihydropyrimidone (DHPM) analogue induces apoptosis-like cell death in clinical isolates of Leishmania donovani overexpressing pteridine reductase 1.

PubMed

Singh, Neeloo; Kaur, Jaspreet; Kumar, Pranav; Gupta, Swati; Singh, Nasib; Ghosal, Angana; Dutta, Avijit; Kumar, Ashutosh; Tripathi, Ramapati; Siddiqi, Mohammad Imran; Mandal, Chitra; Dube, Anuradha

2009-10-01

The protozoan parasite Leishmania donovani is the causative agent of visceral leishmaniasis. The enzyme pteridine reductase 1 (PTR1) of L. donovani acts as a metabolic bypass for drugs targeting dihydrofolate reductase (DHFR); therefore, for successful antifolate chemotherapy to be developed against Leishmania, it must target both enzyme activities. Leishmania cells overexpressing PTR1 tagged at the N-terminal with green fluorescent protein were established to screen for proprietary dihydropyrimidone (DHPM) derivatives of DHFR specificity synthesised in our laboratory. A cell-permeable molecule with impressive antileishmanial in vitro and in vivo oral activity was identified. Structure activity relationship based on homology model drawn on our recombinant enzyme established the highly selective inhibition of the enzyme by this analogue. It was seen that the leishmanicidal effect of this analogue is triggered by programmed cell death mediated by the loss of plasma membrane integrity as detected by binding of annexin V and propidium iodide (PI), loss of mitochondrial membrane potential culminating in cell cycle arrest at the sub-G0/G1 phase and oligonucleosomal DNA fragmentation. Hence, this DHPM analogue [(4-fluoro-phenyl)-6-methyl-2-thioxo-1, 2, 3, 4-tetrahydropyrimidine-5-carboxylic acid ethyl ester] is a potent antileishmanial agent that merits further pharmacological investigation.

Glucose-6-phosphate dehydrogenase and Trypanothione reductase interaction protects Leishmania donovani from metalloid mediated oxidative stress.

PubMed

Ghosh, Ayan Kumar; Saini, Savita; Das, Sushmita; Mandal, Abhishek; Sardar, Abul Hasan; Ansari, Md Yousuf; Abhishek, Kumar; Kumar, Ajay; Singh, Ruby; Verma, Sudha; Equbal, Asif; Ali, Vahab; Das, Pradeep

2017-05-01

Exploration of metabolons as viable drug target is rare in kinetoplastid biology. Here we present a novel protein-protein interaction among Glucose-6-phosphate dehydrogenase (LdG6PDH) and Trypanothione reductase (LdTryR) of Leishmania donovani displaying interconnection between central glucose metabolism and thiol metabolism of this parasite. Digitonin fractionation patterns observed through immunoblotting indicated localisation of both LdG6PDH and LdTryR in cytosol. In-silico and in-vitro interaction observed by size exclusion chromatography, co-purification, pull-down assay and spectrofluorimetric analysis revealed LdG6PDH and LdTryR physically interact with each other in a NADPH dependent manner. Coupled enzymatic assay displayed that NADPH generation was severely impaired by addition of Sb III , As III and Te IV extraneously, which hint towards metalloid driven structural changes of the interacting proteins. Co-purification patterns and pull-down assays also depicted that metalloids (Sb III , As III and Te IV ) hinder the in-vitro interaction of these two enzymes. Surprisingly, metalloids at sub-lethal concentrations induced the in-vivo interaction of LdG6PDH and LdTryR, as analyzed by pull-down assays and fluorescence microscopy signifying protection against metalloid mediated ROS. Inhibition of LdTryR by thioridazine in LdG6PDH -/- parasites resulted in metalloid induced apoptotic death of the parasites due to abrupt fall in reduced thiol content, disrupted NADPH/NADP + homeostasis and lethal oxidative stress. Interestingly, clinical isolates of L.donovani resistant to SAG exhibited enhanced interaction between LdG6PDH and LdTryR and showed cross resistivity towards As III and Te IV . Thus, our findings propose the metabolon of LdG6PDH and LdTryR as an alternate therapeutic target and provide mechanistic insight about metalloid resistance in Visceral Leishmaniasis. Copyright © 2017. Published by Elsevier Inc.

Molecular Preadaptation to Antimony Resistance in Leishmania donovani on the Indian Subcontinent

PubMed Central

Imamura, H.; Zander, D.; D’Haenens, E.; Maes, I.; Domagalska, M. A.; Clos, J.

2018-01-01

ABSTRACT Antimonials (Sb) were used for decades for chemotherapy of visceral leishmaniasis (VL). Now abandoned in the Indian subcontinent (ISC) because of Leishmania donovani resistance, this drug offers a unique model for understanding drug resistance dynamics. In a previous phylogenomic study, we found two distinct populations of L. donovani: the core group (CG) in the Gangetic plains and ISC1 in the Nepalese highlands. Sb resistance was only encountered within the CG, and a series of potential markers were identified. Here, we analyzed the development of resistance to trivalent antimonials (SbIII) upon experimental selection in ISC1 and CG strains. We observed that (i) baseline SbIII susceptibility of parasites was higher in ISC1 than in the CG, (ii) time to SbIII resistance was higher for ISC1 parasites than for CG strains, and (iii) untargeted genomic and metabolomic analyses revealed molecular changes along the selection process: these were more numerous in ISC1 than in the CG. Altogether these observations led to the hypothesis that CG parasites are preadapted to SbIII resistance. This hypothesis was experimentally confirmed by showing that only wild-type CG strains could survive a direct exposure to the maximal concentration of SbIII. The main driver of this preadaptation was shown to be MRPA, a gene involved in SbIII sequestration and amplified in an intrachromosomal amplicon in all CG strains characterized so far. This amplicon emerged around 1850 in the CG, well before the implementation of antimonials for VL chemotherapy, and we discuss here several hypotheses of selective pressure that could have accompanied its emergence. IMPORTANCE The “antibiotic resistance crisis” is a major challenge for scientists and medical professionals. This steady rise in drug-resistant pathogens also extends to parasitic diseases, with antimony being the first anti-Leishmania drug that fell in the Indian subcontinent (ISC). Leishmaniasis is a major but neglected

Prophylactic efficacy of high-molecular-weight antigenic fractions of a recent clinical isolate of Leishmania donovani against visceral leishmaniasis.

PubMed

Tripathi, P; Gupta, S K; Sinha, S; Sundar, S; Dube, A; Naik, S

2008-11-01

T-cell mediated immune responses are key determinants to the natural course of infection caused by intracellular parasites such as Leishmania. Thus, T-cell activating proteins of these microbes continue to generate active interest particularly in view of their possible role in the design and development of newer and more effective vaccines. We have recently reported the presence of T-cell immunostimulatory antigens with the high-molecular-weight (MW) fractions (134-64.2 kDa) of whole Leishmania donovani antigen (strain 2001), which stimulated variable amounts of IFN-gamma, IL-12 and IL-10 in exposed immune individuals. The present study was undertaken to further evaluate these high-MW antigenic fractions (MW range >100-60 kDa) for potential protective efficacy. The high-MW region of the parasite was resolved into five antigenic fractions (Prep A-E) using continuous elution gel electrophoresis. Prior to in vivo protection studies in hamsters, these fractions were used to evaluate in vitro cellular responses in eight Leishmania-exposed individuals and treated cured hamsters. The protective efficacy of prep (A + B), C, D and E in combination with BCG was evaluated in inbred hamsters using standard immunization protocol. Proliferative responses were seen in all eight of eight exposed individuals to prep D [median stimulation index (SI): 5.2 (range 3.9-7.1)] and E [median SI: 5.6 (range 4.4-8.2)], five of eight individuals to prep B and prep C and three of eight to prep A [median SI: 0.2 (range 0.1-7.2)]. The median proliferative responses to prep D and prep E were significantly higher than to fraction prep A; (P < 0.05) but not to prep B and prep C. However, prep A-E induced equivalent levels of IFN-gamma, IL-10 and IL-12 cytokines. Fractions D and E also exhibited marked parasite inhibition in spleen (52.5% and 73.7%) and liver (65% and 80.2%) as compared with prep (A + B) (23% in spleen and 24% in liver) and prep C (38% in spleen and 24% in liver). Prep D and prep E

Th1 stimulatory proteins of Leishmania donovani: comparative cellular and protective responses of rTriose phosphate isomerase, rProtein disulfide isomerase and rElongation factor-2 in combination with rHSP70 against visceral leishmaniasis.

PubMed

Jaiswal, Anil Kumar; Khare, Prashant; Joshi, Sumit; Kushawaha, Pramod Kumar; Sundar, Shyam; Dube, Anuradha

2014-01-01

In visceral leishmaniasis, the recovery from the disease is always associated with the generation of Th1-type of cellular responses. Based on this, we have previously identified several Th1-stimulatory proteins of Leishmania donovani -triose phosphate isomerase (TPI), protein disulfide isomerase (PDI) and elongation factor-2 (EL-2) etc. including heat shock protein 70 (HSP70) which induced Th1-type of cellular responses in both cured Leishmania patients/hamsters. Since, HSPs, being the logical targets for vaccines aimed at augmenting cellular immunity and can be early targets in the immune response against intracellular pathogens; they could be exploited as vaccine/adjuvant to induce long-term immunity more effectively. Therefore, in this study, we checked whether HSP70 can further enhance the immunogenicity and protective responses of the above said Th1-stimulatory proteins. Since, in most of the studies, immunogenicity of HSP70 of L. donovani was assessed in native condition, herein we generated recombinant HSP70 and tested its potential to stimulate immune responses in lymphocytes of cured Leishmania infected hamsters as well as in the peripheral blood mononuclear cells (PBMCs) of cured patients of VL either individually or in combination with above mentioned recombinant proteins. rLdHSP70 alone elicited strong cellular responses along with remarkable up-regulation of IFN-γ and IL-12 cytokines and extremely lower level of IL-4 and IL-10. Among the various combinations, rLdHSP70 + rLdPDI emerged as superior one augmenting improved cellular responses followed by rLdHSP70 + rLdEL-2. These combinations were further evaluated for its protective potential wherein rLdHSP70 + rLdPDI again conferred utmost protection (∼80%) followed by rLdHSP70 + rLdEL-2 (∼75%) and generated a strong cellular immune response with significant increase in the levels of iNOS transcript as well as IFN-γ and IL-12 cytokines which was further supported by the high level of IgG2 antibody

Th1 Stimulatory Proteins of Leishmania donovani: Comparative Cellular and Protective Responses of rTriose Phosphate Isomerase, rProtein Disulfide Isomerase and rElongation Factor-2 in Combination with rHSP70 against Visceral Leishmaniasis

PubMed Central

Jaiswal, Anil Kumar; Khare, Prashant; Joshi, Sumit; Kushawaha, Pramod Kumar; Sundar, Shyam; Dube, Anuradha

2014-01-01

In visceral leishmaniasis, the recovery from the disease is always associated with the generation of Th1-type of cellular responses. Based on this, we have previously identified several Th1-stimulatory proteins of Leishmania donovani -triose phosphate isomerase (TPI), protein disulfide isomerase (PDI) and elongation factor-2 (EL-2) etc. including heat shock protein 70 (HSP70) which induced Th1-type of cellular responses in both cured Leishmania patients/hamsters. Since, HSPs, being the logical targets for vaccines aimed at augmenting cellular immunity and can be early targets in the immune response against intracellular pathogens; they could be exploited as vaccine/adjuvant to induce long-term immunity more effectively. Therefore, in this study, we checked whether HSP70 can further enhance the immunogenicity and protective responses of the above said Th1-stimulatory proteins. Since, in most of the studies, immunogenicity of HSP70 of L. donovani was assessed in native condition, herein we generated recombinant HSP70 and tested its potential to stimulate immune responses in lymphocytes of cured Leishmania infected hamsters as well as in the peripheral blood mononuclear cells (PBMCs) of cured patients of VL either individually or in combination with above mentioned recombinant proteins. rLdHSP70 alone elicited strong cellular responses along with remarkable up-regulation of IFN-γ and IL-12 cytokines and extremely lower level of IL-4 and IL-10. Among the various combinations, rLdHSP70 + rLdPDI emerged as superior one augmenting improved cellular responses followed by rLdHSP70 + rLdEL-2. These combinations were further evaluated for its protective potential wherein rLdHSP70 + rLdPDI again conferred utmost protection (∼80%) followed by rLdHSP70 + rLdEL-2 (∼75%) and generated a strong cellular immune response with significant increase in the levels of iNOS transcript as well as IFN-γ and IL-12 cytokines which was further supported by the high level of IgG2 antibody

Chemoprevention of Leishmaniasis: In vitro antiparasitic activity of dibenzalacetone, a synthetic curcumin analog leads to apoptotic cell death in Leishmania donovani.

PubMed

Chauhan, Indira Singh; SubbaRao, G; Shankar, Jai; Chauhan, Lalit Kumar Singh; Kapadia, Govind J; Singh, Neeloo

2018-06-15

Curcumin is the major phenolic compound found in turmeric, a dry powder of rhizomes and roots of the plant, Curcuma longa L., which is widely used as spice and food colorant around the world, and in herbal medicinal practice in Asian countries. The present study reports the leishmanicidal activity of trans-dibenzalacetone (DBA), a synthetic monoketone analog of curcumin, against Leishmania donovani parasites. We for the first time report the antiproliferative effect of a curcumin analog (DBA) on the intracellular amastigotes of L. donovani, the clinically more relevant stage of the parasite than its promastigotes stage. The leishmanicidal effect of DBA was further confirmed by scanning and transmission electron microscopies. Cell growth was arrested in G0/G1 phase with increased concentration of cytosolic calcium and dissipation of mitochondrial membrane potential. Further, the unique trypanothione/trypanothione reductase (TR) system of Leishmania cells was significantly inhibited by DBA. This economically synthesizable simple monoketone analog of curcumin has the potential for field use against visceral leishmaniasis which is currently widespread in tropical and subtropical developing countries of the world. In conclusion, we have identified an analog of curcumin for potential applications against leishmaniasis, based on its strong antiparasitic activity and low toxicity. This curcumin analog compares favorably, at least in vitro, with the existing medication miltefosine. Copyright © 2017. Published by Elsevier B.V.

Ascorbate peroxidase, a key molecule regulating amphotericin B resistance in clinical isolates of Leishmania donovani.

PubMed

Kumar, Ashish; Das, Sushmita; Purkait, Bidyut; Sardar, Abul Hasan; Ghosh, Ayan Kumar; Dikhit, Manas Ranjan; Abhishek, Kumar; Das, Pradeep

2014-10-01

Amphotericin B (AmB), a polyene macrolide, is now a first-line treatment of visceral leishmaniasis cases refractory to antimonials in India. AmB relapse cases and the emergence of secondary resistance have now been reported. To understand the mechanism of AmB, differentially expressed genes in AmB resistance strains were identified by a DNA microarray and real-time reverse transcriptase PCR (RT-PCR) approach. Of the many genes functionally overexpressed in the presence of AmB, the ascorbate peroxidase gene from a resistant Leishmania donovani strain (LdAPx gene) was selected because the gene is present only in Leishmania, not in humans. Apoptosis-like cell death after exposure to AmB was investigated in a wild-type (WT) strain in which the LdAPx gene was overexpressed and in AmB-sensitive and -resistant strains. A higher percentage of apoptosis-like cell death after AmB treatment was noticed in the sensitive strain than in both the resistant isolate and the strain sensitive to LdAPx overexpression. This event is preceded by AmB-induced formation of reactive oxygen species and elevation of the cytosolic calcium level. Enhanced cytosolic calcium was found to be responsible for depolarization of the mitochondrial membrane potential and the release of cytochrome c (Cyt c) into the cytosol. The redox behavior of Cyt c showed that it has a role in the regulation of apoptosis-like cell death by activating metacaspase- and caspase-like proteins and causing concomitant nuclear alterations, as determined by terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) and DNA fragmentation in the resistant strain. The present study suggests that constitutive overexpression of LdAPx in the L. donovani AmB-resistant strain prevents cells from the deleterious effect of oxidative stress, i.e., mitochondrial dysfunction and cellular death induced by AmB. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Antimony resistant Leishmania donovani but not sensitive ones drives greater frequency of potent T-regulatory cells upon interaction with human PBMCs: role of IL-10 and TGF-β in early immune response.

PubMed

Guha, Rajan; Das, Shantanabha; Ghosh, June; Sundar, Shyam; Dujardin, Jean Claude; Roy, Syamal

2014-07-01

In India the sand fly, Phlebotomus argentipes, transmitted parasitic disease termed kala-azar is caused by Leishmania donovani (LD) in humans. These immune-evading parasites have increasingly developed resistance to the drug sodium antimony gluconate in endemic regions. Lack of early diagnosis methods for the disease limits the information available regarding the early interactions of this parasite with either human tissues or cell lineages. We reasoned that peripheral blood mononuclear cells (PBMCs) from healthy human beings could help compare some of their immune signatures once they were exposed for up to 8 days, to either pentavalent antimony sensitive (Sb(S)-LD) or resistant (Sb(R)-LD) Leishmania donovani isolates. At day 2, PBMC cultures exposed to Sb(S)-LD and Sb(R)-LD stationary phase promastigotes had four and seven fold higher frequency of IL-10 secreting monocyte-macrophage respectively, compared to cultures unexposed to parasites. Contrasting with the CD4(+)CD25-CD127- type-1 T-regulatory (Tr1) cell population that displayed similar features whatever the culture conditions, there was a pronounced increase in the IL-10 producing CD4(+)CD25(+)CD127low/- inducible T-regulatory cells (iTregs) in the PBMC cultures sampled at day 8 post addition of Sb(R)-LD. Sorted iTregs from different cultures on day 8 were added to anti-CD3/CD28 induced naïve PBMCs to assess their suppressive ability. We observed that iTregs from Sb(R)-LD exposed PBMCs had more pronounced suppressive ability compared to Sb(S)-LD counterpart on a per cell basis and is dependent on both IL-10 and TGF-β, whereas IL-10 being the major factor contributing to the suppressive ability of iTregs sorted from PBMC cultures exposed to Sb(S)-LD. Of note, iTreg population frequency value remained at the basal level after addition of genetically modified Sb(R)-LD lacking unique terminal sugar in surface glycan. Even with limitations of this artificial in vitro model of L. donovani-human PBMC

Reaction kinetics and inhibition of adenosine kinase from Leishmania donovani.

PubMed

Bhaumik, D; Datta, A K

1988-04-01

The reaction kinetics and the inhibitor specificity of adenosine kinase (ATP:adenosine 5'-phosphotransferase, EC 2.7.1.20) from Leishmania donovani, have been analysed using homogeneous preparation of the enzyme. The reaction proceeds with equimolar stoichiometry of each reactant. Double reciprocal plots of initial velocity studies in the absence of products yielded intersecting lines for both adenosine and Mg2+-ATP. AMP is a competitive inhibitor of the enzyme with respect to adenosine and noncompetitive inhibitor with respect to ATP. In contrast, ADP was a noncompetitive inhibitor with respect to both adenosine and ATP, with inhibition by ADP becoming uncompetitive at very high concentration of ATP. Parallel equilibrium dialysis experiments against [3H]adenosine and [gamma-32P]ATP resulted in binding of adenosine to fre enzyme. Tubercidin (7-deazaadenosine) and 6-methyl-mercaptopurine riboside acted as substrates for the enzyme and were found to inhibit adenosine phosphorylation competitively in vitro. 'Substrate efficiency (Vmax/Km)' and 'turnover numbers (Kcat)' of the enzyme with respect to specific analogs were determined. Taken together the results suggest that (a) the kinetic mechanism of adenosine kinase is sequential Bi-Bi, (b) AMP and ADP may regulate enzyme activity in vivo and (c) tubercidin and 6-methylmercaptopurine riboside are monophosphorylated by the parasite enzyme.

Interaction between cysteine synthase and serine O-acetyltransferase proteins and their stage specific expression in Leishmania donovani.

PubMed

Singh, Kuljit; Singh, Krishn Pratap; Equbal, Asif; Suman, Shashi S; Zaidi, Amir; Garg, Gaurav; Pandey, Krishna; Das, Pradeep; Ali, Vahab

2016-12-01

Leishmania possess a unique trypanothione redox metabolism with undebated roles in protection from oxidative damage and drug resistance. The biosynthesis of trypanothione depends on l-cysteine bioavailability which is regulated by cysteine biosynthesis pathway. The de novo cysteine biosynthesis pathway is comprised of serine O-acetyltransferase (SAT) and cysteine synthase (CS) enzymes which sequentially mediate two consecutive steps of cysteine biosynthesis, and is absent in mammalian host. However, despite the apparent dependency of redox metabolism on cysteine biosynthesis pathway, the role of SAT and CS in redox homeostasis has been unexplored in Leishmania parasites. Herein, we have characterized CS and SAT to investigate their interaction and relative abundance of these proteins in promastigote vs. amastigote growth stages of L. donovani. CS and SAT genes of L. donovani (LdCS and LdSAT) were cloned, expressed, and fusion proteins purified to homogeneity with affinity column chromatography. Purified LdCS contains PLP as cofactor and showed optimum enzymatic activity at pH 7.5. Enzyme kinetics showed that LdCS catalyses the synthesis of cysteine using O-acetylserine and sulfide with a K m of 15.86 mM and 0.17 mM, respectively. Digitonin fractionation and indirect immunofluorescence microscopy showed that LdCS and LdSAT are localized in the cytoplasm of promastigotes. Size exclusion chromatography, co-purification, pull down and immuno-precipitation assays demonstrated a stable complex formation between LdCS and LdSAT proteins. Furthermore, LdCS and LdSAT proteins expression/activity was upregulated in amastigote growth stage of the parasite. Thus, the stage specific differential expression of LdCS and LdSAT suggests that it may have a role in the redox homeostasis of Leishmania. Copyright © 2016 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Apoptosis-like cell death in Leishmania donovani treated with KalsomeTM10, a new liposomal amphotericin B

PubMed Central

Shadab, Md.; Jha, Baijayanti; Asad, Mohammad; Deepthi, Makaraju; Kamran, Mohd.; Ali, Nahid

2017-01-01

Objective The present study aimed to elucidate the cell death mechanism in Leishmania donovani upon treatment with KalsomeTM10, a new liposomal amphotericin B. Methodology/Principal findings We studied morphological alterations in promastigotes through phase contrast and scanning electron microscopy. Phosphatidylserine (PS) exposure, loss of mitochondrial membrane potential and disruption of mitochondrial integrity was determined by flow cytometry using annexinV-FITC, JC-1 and mitotraker, respectively. For analysing oxidative stress, generation of H2O2 (bioluminescence kit) and mitochondrial superoxide O2− (mitosox) were measured. DNA fragmentation was evaluated using terminal deoxyribonucleotidyl transferase mediated dUTP nick-end labelling (TUNEL) and DNA laddering assay. We found that KalsomeTM10 is more effective then Ambisome against the promastigote as well as intracellular amastigote forms. The mechanistic study showed that KalsomeTM10 induced several morphological alterations in promastigotes typical of apoptosis. KalsomeTM10 treatment showed a dose- and time-dependent exposure of PS in promastigotes. Further, study on mitochondrial pathway revealed loss of mitochondrial membrane potential as well as disruption in mitochondrial integrity with depletion of intracellular pool of ATP. KalsomeTM10 treated promastigotes showed increased ROS production, diminished GSH levels and increased caspase-like activity. DNA fragmentation and cell cycle arrest was observed in KalsomeTM10 treated promastigotes. Apoptotic DNA fragmentation was also observed in KalsomeTM10 treated intracellular amastigotes. KalsomeTM10 induced generation of ROS and nitric oxide leads to the killing of the intracellular parasites. Moreover, endocytosis is indispensable for KalsomeTM10 mediated anti-leishmanial effect in host macrophage. Conclusions KalsomeTM10 induces apoptotic-like cell death in L. donovani parasites to exhibit its anti-leishmanial function. PMID:28170432

Proline transport in Leishmania donovani amastigotes: dependence on pH gradients and membrane potential.

PubMed

Glaser, T A; Mukkada, A J

1992-03-01

Amastigotes of Leishmania donovani develop and multiply within the acidic phagolysosomes of mammalian macrophages. Isolated amastigotes are acidophilic; they catabolize substrates and synthesize macromolecules optimally at pH 5.5. Substrate transport in amastigotes has not been characterized. Here we show that amastigotes exhibit an uphill transport of proline (active transport) with an acid pH optimum (pH 5.5). It is dependent upon metabolic energy and is driven by proton motive force. Agents which selectively disturb the component forces of proton motive force, such as carbonyl cyanide chlorophenylhydrazone, nigericin and valinomycin, inhibit proline transport. Transport is sensitive to dicyclohexylcarbodiimide and insensitive to ouabain, demonstrating the involvement of a proton ATPase in the maintenance of proton motive force. It is suggested that the plasma membrane pH gradient probably makes the greatest contribution to proton motive force that drives substrate transport in the amastigote stage.

Interaction of frataxin, an iron binding protein, with IscU of Fe-S clusters biogenesis pathway and its upregulation in AmpB resistant Leishmania donovani.

PubMed

Zaidi, Amir; Singh, Krishn Pratap; Anwar, Shadab; Suman, Shashi S; Equbal, Asif; Singh, Kuljit; Dikhit, Manas R; Bimal, Sanjeeva; Pandey, Krishna; Das, Pradeep; Ali, Vahab

2015-08-01

Leishmania donovani is a unicellular protozoon parasite that causes visceral leishmaniasis (VL), which is a fatal disease if left untreated. Certain Fe-S proteins of the TCA cycle and respiratory chain have been found in the Leishmania parasite but the precise mechanisms for their biogenesis and the maturation of Fe-S clusters remains unknown. Fe-S clusters are ubiquitous cofactors of proteins that perform critical cellular functions. The clusters are biosynthesized by the mitochondrial Iron-Sulphur Cluster (ISC) machinery with core protein components that include the catalytic cysteine desulphurase IscS, the scaffold proteins IscU and IscA, and frataxin as an iron carrier/donor. However, no information regarding frataxin, its regulation, or its role in drug resistance is available for the Leishmania parasite. In this study, we characterized Ld-frataxin to investigate its role in the ISC machinery of L. donovani. We expressed and purified the recombinant Ld-frataxin protein and observed its interaction with Ld-IscU by co-purification and pull-down assay. Furthermore, we observed that the cysteine desulphurase activity of the purified Ld-IscS protein was stimulated in the presence of Ld-frataxin and Ld-IscU, particularly in the presence of iron; neither Ld-frataxin nor Ld-IscU alone had significant effects on Ld-IscS activity. Interestingly, RT-PCR and western blotting showed that Ld-frataxin is upregulated in AmpB-resistant isolates compared to sensitive strains, which may support higher Fe-S protein activity in AmpB-resistant L. donovani. Additionally, Ld-frataxin was localized in the mitochondria, as revealed by digitonin fractionation and indirect immunofluorescence. Thus, our results suggest the role of Ld-frataxin as an iron binding/carrier protein for Fe-S cluster biogenesis that physically interacts with other core components of the ISC machinery within the mitochondria. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Mol

Quercetin interferes with iron metabolism in Leishmania donovani and targets ribonucleotide reductase to exert leishmanicidal activity.

PubMed

Sen, Gargi; Mukhopadhyay, Sibabrata; Ray, Manju; Biswas, Tuli

2008-05-01

The possibility of developing antileishmanial drugs was evaluated by intervention in the parasite's iron metabolism, utilizing quercetin (Qr) under in vivo conditions, and identifying the target of this lipophilic metal chelator against Leishmania donovani. Interaction between Qr and serum albumin (SA) was studied by using the intrinsic fluorescence of Qr as a probe. The effect of treatment with Qr and SA on the proliferation of amastigotes was determined by evaluating splenic parasite load. Disintegration of parasites in response to combination treatment was assessed from ultrastructural analysis using a transmission electron microscope. Quenching of the tyrosyl radical of ribonucleotide reductase (RR) in treated amastigotes was detected by an electron paramagnetic resonance study. Treatment with a combination of Qr and SA increased bioavailability of the flavonoid and proved to be of major advantage in promoting the effectiveness of Qr towards the repression of splenic parasite load from 75%, P < 0.01 to 95%, P < 0.002. Qr-mediated down-regulation of RR (P < 0.05), catalysing the rate-limiting step of DNA synthesis in the pathogens, could be related to the deprivation of the enzyme of iron which in turn destabilized the critical tyrosyl radical required for its catalysing activity. Results have implications for improved leishmanicidal action of Qr in combination with SA targeting RR and suggest future drug design based on interference with the parasite's iron metabolism under in vivo conditions.

Imaging host cell-Leishmania interaction dynamics implicates parasite motility, lysosome recruitment, and host cell wounding in the infection process.

PubMed

Forestier, Claire-Lise; Machu, Christophe; Loussert, Celine; Pescher, Pascale; Späth, Gerald F

2011-04-21

Leishmania donovani causes human visceral leishmaniasis. The parasite infectious cycle comprises extracellular flagellated promastigotes that proliferate inside the insect vector, and intracellular nonmotile amastigotes that multiply within infected host cells. Using primary macrophages infected with virulent metacyclic promastigotes and high spatiotemporal resolution microscopy, we dissect the dynamics of the early infection process. We find that motile promastigotes enter macrophages in a polarized manner through their flagellar tip and are engulfed into host lysosomal compartments. Persistent intracellular flagellar activity leads to reorientation of the parasite flagellum toward the host cell periphery and results in oscillatory parasite movement. The latter is associated with local lysosomal exocytosis and host cell plasma membrane wounding. These findings implicate lysosome recruitment followed by lysosome exocytosis, consistent with parasite-driven host cell injury, as key cellular events in Leishmania host cell infection. This work highlights the role of promastigote polarity and motility during parasite entry. Copyright © 2011 Elsevier Inc. All rights reserved.

Antileishmanial and immunomodulatory activities of lupeol, a triterpene compound isolated from Sterculia villosa.

PubMed

Das, Antu; Jawed, Junaid Jibran; Das, Manash C; Sandhu, Padmani; De, Utpal C; Dinda, Biswanath; Akhter, Yusuf; Bhattacharjee, Surajit

2017-10-01

Visceral leishmaniasis (VL) is one of the most severe forms of leishmaniasis, caused by the protozoan parasite Leishmania donovani. Nowadays there is a growing interest in the therapeutic use of natural products to treat parasitic diseases. Sterculia villosa is an ethnomedicinally important plant. A triterpenoid was isolated from this plant and was screened for its antileishmanial and immunomodulatory activities in vitro and in vivo. Biochemical colour test and spectroscopic data confirmed that the isolated pure compound was lupeol. Lupeol exhibited significant antileishmanial activity, with IC 50 values of 65 ± 0.41 µg/mL and 15 ± 0.45 µg/mL against promastigote and amastigote forms, respectively. Lupeol caused maximum cytoplasmic membrane damage of L. donovani promastigote at its IC 50 dose. It is well known that during infection the Leishmania parasite exerts its pathogenicity in the host by suppressing nitric oxide (NO) production and inhibiting pro-inflammatory responses. It was observed that lupeol induces NO generation in L. donovani-infected macrophages, followed by upregulation of pro-inflammatory cytokines and downregulation of anti-inflammatory cytokines. Lupeol was also found to reduce the hepatic and splenic parasite burden through upregulation of the pro-inflammatory response in L. donovani-infected BALB/c mice. Strong binding affinity of lupeol was observed for four major potential drug targets, namely pteridine reductase 1, adenine phosphoribosyltransferase, lipophosphoglycan biosynthetic protein and glycoprotein 63 of L. donovani, which also supported its antileishmanial and immunomodulatory activities. Therefore, the present study highlights the antileishmanial and immunomodulatory activities of lupeol in an in vitro and in vivo model of VL. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

Studies on cocktails of 31-kDa, 36-kDa and 51-kDa antigens of Leishmania donovani along with saponin against murine visceral leishmaniasis.

PubMed

Kaur, H; Thakur, A; Kaur, S

2015-04-01

A substantial number of antigens of Leishmania donovani have been described in the past. However, identifying candidate antigens is not enough. Appropriate antigen delivery to induce the right type of immune response against leishmaniasis (i.e. induction of a strong antigen-specific Th1 type of immune response) is another crucial component of an effective vaccine. Therefore, 'cocktail' vaccines are proposed based on the assumption that such cocktails will show enhanced efficacy. Studies have been carried out on LD31 and LD51 polypeptides from L. donovani promastigotes, which have proven to be potential vaccine candidates. This study was designed to check the protective efficacy of various cocktails of low molecular weight antigens alone and along with saponin as adjuvant. Mice were sacrificed on different post-challenge days for evaluation of parasite load and other immunological parameters. Protective efficacy of different vaccine formulations was revealed by significant decline in parasite burden and increased DTH Delayed Type Hypersenstivity responses. The antibody response was of IgG type with elevated IgG2a and decreased production of IgG1, whereas cytokine levels pointed towards the generation of protective Th1 type of immune response. Among all vaccine formulations, cocktail of 31+51+saponin was found to be highly immunogenic and imparted maximum protection. © 2015 John Wiley & Sons Ltd.

Leishmania donovani: expression and characterization of Escherichia coli-expressed recombinant chitinase LdCHT1.

PubMed

Razek-Desouky, A; Specht, C A; Soong, L; Vinetz, J M

2001-12-01

Leishmania parasites produce chitinase activity (EC. 3.2.1.14) thought to be important in parasite-sandfly interactions and transmission of the parasite to the vertebrate host. Previous observations have suggested that parasite chitinases are involved in degradation of the sandfly peritrophic matrix and the chitinous layer of the cardiac valve cuticle. This chitinase activity is thought to produce an incompetent pharyngeal valve sphincter and a route of egress that allow Leishmania promastigotes to be regurgitated into the site of blood feeding. In the studies reported here, enzymatically active L. donovani chitinase LdCHT1 was expressed as a thioredoxin fusion protein in Escherichia coli strain AD494 (DE3). Recombinant LdCHT1 had a predominantly endochitinase activity, in contrast to previous reports of both exo- and endochitinase activities in axenic culture supernatants of diverse Leishmania spp. promastigotes. The predominant endochitinase activity of recombinant LdCHT1 is consistent with the presumed function of the enzyme in disrupting chitinous structures in the sandfly digestive system to allow transmission. Copyright 2001 Elsevier Science (USA).

Pharmacy Students' Knowledge Assessment of Naegleria fowleri Infection

PubMed Central

Shakeel, Sadia; Iffat, Wajiha; Khan, Madeeha

2016-01-01

A cross-sectional study was conducted from April to August 2015 to assess the knowledge of pharmacy students towards Naegleria fowleri infection. A questionnaire was distributed to senior pharmacy students in different private and public sector universities of Karachi. Descriptive statistics were used to demonstrate students' demographic information and their responses to the questionnaire. Pearson chi-square test was adopted to assess the relationship between independent variables and responses of students. The study revealed that pharmacy students were having adequate awareness of Naegleria fowleri infection and considered it as a serious health issue that necessitates instantaneous steps by the government to prevent the general public from the fatal neurological infection. The students recommended that appropriate methods should be projected in the community from time to time that increases public awareness about the associated risk factors. PMID:26981318

Kinetics and molecular characteristics of arginine transport by Leishmania donovani promastigotes.

PubMed

Kandpal, M; Fouce, R B; Pal, A; Guru, P Y; Tekwani, B L

1995-05-01

Characteristics of transport of L-arginine were studied in Leishmania donovani promastigotes grown in vitro in a defined medium. The promastigotes exhibited a time-dependent, temperature-sensitive, pH-dependent and saturable uptake of arginine. Metabolic inhibitors caused 81-92% inhibition, indicating that arginine influx in promastigotes is an energy requiring process. The presence of Na+ ions was necessary for full activity. Considerable inhibition was also noticed with valinomycin, gramicidin and amiloride. The transporter seems to involve an -SH group at the active site. The most distinctive feature of the leishmanial transporter was that lysine and ornithine did not show significant competition with arginine transport. Other neutral and acidic amino acids, as well as polyamines were also ineffective. The arginine analogues, viz., nitro-L-arginine methyl ester, N-nitro-L-arginine, aminoguanidine, agmatine and D-arginine were not recognised by the transporter, while N-methyl-L-arginine acetate and phospho-L-arginine showed competition, indicating stereo-specificity of the transporter and recognition of both the guanidino group, as well as the arginine side chain by the transporter. No exchange of intracellular [14C]arginine taken up by the promastigotes was noticed during incubation with 2 or 5 mM arginine in the extracellular medium. Eighty percent of the arginine taken up remained in the trichloroacetic acid-soluble fraction. Pentamidine caused competitive inhibition of arginine transport, exhibiting an IC50 value of 40 microM. Results indicate the presence of a novel distinct arginine transporter in Leishmania promastigotes.

Cell-free biosynthesis of lipophosphoglycan from Leishmania donovani. Characterization of microsomal galactosyltransferase and mannosyltransferase activities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carver, M.A.; Turco, S.J.

1991-06-15

Incubation of microsomal preparations from Leishmania donovani parasites with UDP-({sup 3}H)galactose or GDP-({sup 14}C)mannose resulted in incorporation of radiolabel into an endogenous product that exhibited the chemical and chromatographic characteristics of the parasite's major surface glycoconjugate, lipophosphoglycan. The ({sup 3}H)galactose- or ({sup 14}C)mannose-labeled product was (1) cleaved by phosphatidylinositol-specific phospholipase C; (2) deaminated by nitrous acid; and (3) degraded into radioactive, low molecular weight fragments upon hydrolysis with mild acid. Analysis of the products of mild acid hydrolysis revealed the presence of phosphorylated Gal-beta-Man as the major fragment with lesser amounts of mono-, tri-, and tetrasaccharides. The incorporation of themore » two isotopic precursors was neither stimulated by the addition of dolichylphosphate nor inhibited by amphomycin, indicating that dolichol-saccharide intermediates are not involved in assembly of the repeating units of lipophosphoglycan. Development of this cell-free glycosylating system will facilitate further studies on the pathway and enzymes involved in lipophosphoglycan biosynthesis.« less

Assessing hospital emergency management plans: a guide for infection preventionists.

PubMed

Rebmann, Terri

2009-11-01

Hospital emergency management plans are essential and must include input from an infection preventionist (IP). Multiple hospital planning documents exist, but many do not address infection prevention issues, combine them with noninfection prevention issues, or are disease/event specific. An all-encompassing emergency management planning guide for IPs is needed. A literature review and Internet search were conducted in December 2008. Data from relevant sources were extracted. A spreadsheet was created that delineated hospital emergency management plan components of interest to IPs. Of the sources screened, 49 were deemed relevant. Eleven domains were identified: (1) having a plan; (2) assessing hospital readiness; (3) having infection prevention policies and procedures; (4) having occupational health policies and procedures; (5) conducting surveillance and triage; (6) reporting incidents, having a communication plan, and managing information; (7) having laboratory support; (8) addressing surge capacity issues; (9) having anti-infective therapy and/or vaccines; (10) providing infection prevention education; and (11) managing physical plant issues. Infection preventionists should use this article as an assessment tool for evaluating their hospital emergency management plan and for developing policies and procedures that will decrease the risk of infection transmission during a mass casualty event.

Immunization with Leishmania donovani protein disulfide isomerase DNA construct induces Th1 and Th17 dependent immune response and protection against experimental visceral leishmaniasis in Balb/c mice.

PubMed

Amit, Ajay; Vijayamahantesh; Dikhit, Manas R; Singh, Ashish Kumar; Kumar, Vikash; Suman, Shashi S; Singh, Ashu; Kumar, Akhilesh; Thakur, Ajit Kumar; Das, Vidyanand Ravi; Das, Pradeep; Bimal, Sanjiva

2017-02-01

In the present study, the efficacy of Leishmania donovani protein disulfide isomerase (LdPDI) as a DNA vaccine was evaluated in BALB/C mice. Mice immunized with the LdPDI-DNA construct were found to be the most immuno-reactive, as the construct induced higher T-cell proliferation. The increased T-cell proliferation was associated with a substantial rise in Th1 and Th17+ CD4 cell response and triggered a higher proportion of CD8+ T cells for the release of interferon-gamma along with a reduced splenic parasite load on Days20 and 60 post challenge (PC). Furthermore, the vaccine construct triggered increased interferon (IFN)-γ, interleukin(IL)-17A, and IL-22 release accompanied by decreased extracellular signal-regulated kinases (ERK) 1/2 signaling and increased mitogen-activated protein kinase (MAPK) signaling coinciding with an increase in the amount of nitrite and reactive oxygen species (ROS)in vaccinating the splenocyts. We summarize from our data that the PDI-DNA construct of Leishmania donovani has the potential to elicit protective immunity through the pro-inflammatory cytokines of CD8+ and CD4+(Th1 and Th17) following an intervention in the downstream signaling event of ERK1/2 (probably through p38MAPK signaling). Therefore, the study suggests a new control against visceral leishmaniasis in the future. Copyright © 2016 Elsevier Ltd. All rights reserved.

An outbreak investigation of visceral leishmaniasis among residents of Dharan town, eastern Nepal, evidence for urban transmission of Leishmania donovani

PubMed Central

2013-01-01

Background Visceral leishmaniasis (VL) is a predominantly rural disease, common in the low lands of eastern Nepal. Since 1997 VL cases have also been reported among residents of the city of Dharan. Our main research objective was to find out whether there had been local transmission of VL inside the city. Methods We conducted an outbreak investigation including a case–control study; cases were all urban residents treated for VL between 2000 and 2008 at BP Koirala Institute of Health Sciences, a university hospital in the city. For each case, we selected four random controls, with no history of previous VL; frequency-matched for age. Cases and controls were subjected to a structured interview on the main exposures of interest and potential confounders; a binominal multilevel model was used to analyze the data. We also collected entomological data from all neighborhoods of the city. Results We enrolled 115 VL patients and 448 controls. Cases were strongly clustered, 70% residing in 3 out of 19 neighborhoods. We found a strong association with socio-economic status, the poorest being most at risk. Housing was a risk factor independent from socio-economic status, most at risk were those living in thatched houses without windows. ‘Sleeping upstairs’ and ‘sleeping on a bed’ were strongly protective, OR of 0.08 and 0.25 respectively; proximity to a case was a strong risk factor (OR 3.79). Sand flies were captured in all neighborhoods; in collections from several neighborhoods presence of L. donovani could be demonstrated by PCR. Conclusion The evidence found in this study is consistent with transmission of anthroponotic VL within the city. The vector P. argentipes and the parasite L. donovani have both been identified inside the town. These findings are highly relevant for policy makers; in VL endemic areas appropriate surveillance and disease control measures must be adopted not only in rural areas but in urban areas as well. PMID:23327548

A New Model of Progressive Visceral Leishmaniasis in Hamsters by Natural Transmission via Bites of Vector Sand Flies

PubMed Central

Aslan, Hamide; Dey, Ranadhir; Meneses, Claudio; Castrovinci, Philip; Jeronimo, Selma Maria Bezerra; Oliva, Gætano; Fischer, Laurent; Duncan, Robert C.; Nakhasi, Hira L.; Valenzuela, Jesus G.; Kamhawi, Shaden

2013-01-01

Background. Visceral leishmaniasis (VL) is transmitted by sand flies. Protection of needle-challenged vaccinated mice was abrogated in vector-initiated cutaneous leishmaniasis, highlighting the importance of developing natural transmission models for VL. Methods. We used Lutzomyia longipalpis to transmit Leishmania infantum or Leishmania donovani to hamsters. Vector-initiated infections were monitored and compared with intracardiac infections. Body weights were recorded weekly. Organ parasite loads and parasite pick-up by flies were assessed in sick hamsters. Results. Vector-transmitted L. infantum and L. donovani caused ≥5-fold increase in spleen weight compared with uninfected organs and had geometric mean parasite loads (GMPL) comparable to intracardiac inoculation of 107–108 parasites, although vector-initiated disease progression was slower and weight loss was greater. Only vector-initiated L. infantum infections caused cutaneous lesions at transmission and distal sites. Importantly, 45.6%, 50.0%, and 33.3% of sand flies feeding on ear, mouth, and testicular lesions, respectively, were parasite-positive. Successful transmission was associated with a high mean percent of metacyclics (66%–82%) rather than total GMPL (2.0 × 104–8.0 × 104) per midgut. Conclusions. This model provides an improved platform to study initial immune events at the bite site, parasite tropism, and pathogenesis and to test drugs and vaccines against naturally acquired VL. PMID:23288926

Leishmania major Infection Activates NF-κB and Interferon Regulatory Factors 1 and 8 in Human Dendritic Cells▿

PubMed Central

Jayakumar, Asha; Donovan, Michael J.; Tripathi, Vinita; Ramalho-Ortigao, Marcelo; McDowell, Mary Ann

2008-01-01

The salient feature of dendritic cells (DC) is the initiation of appropriate adaptive immune responses by discriminating between pathogens. Using a prototypic model of intracellular infection, we previously showed that Leishmania major parasites prime human DC for efficient interleukin-12 (IL-12) secretion. L. major infection is associated with self-limiting cutaneous disease and powerful immunity. In stark contrast, the causative agent of visceral leishmaniasis, Leishmania donovani, does not prime human DC for IL-12 production. Here, we report that DC priming by L. major infection results in the early activation of NF-κB transcription factors and the up-regulation and nuclear translocation of interferon regulatory factor 1 (IRF-1) and IRF-8. The inhibition of NF-κB activation by the pretreatment of DC with caffeic acid phenethyl ester blocks L. major-induced IRF-1 and IRF-8 activation and IL-12 expression. We further demonstrate that IRF-1 and IRF-8 obtained from L. major-infected human DC specifically bind to their consensus binding sites on the IL-12p35 promoter, indicating that L. major infection either directly stimulates a signaling cascade or induces an autocrine pathway that activates IRF-1 and IRF-8, ultimately resulting in IL-12 transcription. PMID:18316378

Prediction and analysis of promiscuous T cell-epitopes derived from the vaccine candidate antigens of Leishmania donovani binding to MHC class-II alleles using in silico approach.

PubMed

Kashyap, Manju; Jaiswal, Varun; Farooq, Umar

2017-09-01

Visceral leishmaniasis is a dreadful infectious disease and caused by the intracellular protozoan parasites, Leishmania donovani and Leishmania infantum. Despite extensive efforts for developing effective prophylactic vaccine, still no vaccine is available against leishmaniasis. However, advancement in immunoinformatics methods generated new dimension in peptide based vaccine development. The present study was aimed to identify T-cell epitopes from the vaccine candidate antigens like Lipophosphogylcan-3(LPG-3) and Nucleoside hydrolase (NH) from the L. donovani using in silico methods. Available best tools were used for the identification of promiscuous peptides for MHC class-II alleles. A total of 34 promiscuous peptides from LPG-3, 3 from NH were identified on the basis of their 100% binding affinity towards all six HLA alleles, taken in this study. These peptides were further checked computationally to know their IFN-γ and IL4 inducing potential and nine peptides were identified. Peptide binding interactions with predominant HLA alleles were done by docking. Out of nine docked promiscuous peptides, only two peptides (QESRILRVIKKKLVR, RILRVIKKKLVRKTL), from LPG-3 and one peptide (FDKFWCLVIDALKRI) from NH showed lowest binding energy with all six alleles. These promiscuous T-cell epitopes were predicted on the basis of their antigenicity, hydrophobicity, potential immune response and docking scores. The immunogenicity of predicted promiscuous peptides might be used for subunit vaccine development with immune-modulating adjuvants. Copyright © 2017 Elsevier B.V. All rights reserved.

Development of a Species-Specific PCR Assay for Detection of Leishmania donovani in Clinical Samples from Patients with Kala-Azar and Post-Kala-Azar Dermal Leishmaniasis

PubMed Central

Salotra, Poonam; Sreenivas, G.; Pogue, Gregory P.; Lee, Nancy; Nakhasi, Hira L.; Ramesh, V.; Negi, N. S.

2001-01-01

We have developed a PCR assay that is capable of amplifying kinetoplast DNA (kDNA) of Leishmania donovani in a species-specific manner among Old World leishmanias. With Indian strains and isolates of L. donovani the assay was sensitive enough to detect kDNA in an amount equivalent to a single parasite or less. The extreme sensitivity of the assay was reflected in its ability to detect parasite DNA from small volumes of peripheral blood of patients with kala-azar (KA) and from skin lesions from patients with post-KA dermal leishmaniasis (PKDL). A total of 107 clinical leishmaniasis samples were analyzed. Of these 102 (95.3%) were positive by PCR. The test provided a diagnosis of KA with 96% sensitivity using patient whole-blood samples instead of bone marrow or spleen aspirates that are obtained by invasive procedures. The assay was also successful in the diagnosis of 45 of 48 PKDL cases (93.8%). Cross-reactions with pathogens prevalent in the area of endemicity, viz., Mycobacterium tuberculosis, Mycobacterium leprae, and Plasmodium spp., could be ruled out. Eighty-one control samples, including dermal scrapings from healthy portions of skin from patients with PKDL were all negative. Two of twenty controls from the area of endemicity were found positive by PCR assay; however, there was a good possibility that these two were asymptomatic carriers since they were serologically positive for KA. Thus, this PCR assay represents a tool for the diagnosis of KA and PKDL in Indian patients in a noninvasive manner, with simultaneous species identification of parasites in clinical samples. PMID:11230394

The lignan glycosides lyoniside and saracoside poison the unusual type IB topoisomerase of Leishmania donovani and kill the parasite both in vitro and in vivo.

PubMed

Saha, Sourav; Mukherjee, Tulika; Chowdhury, Sayan; Mishra, Amartya; Chowdhury, Somenath Roy; Jaisankar, Parasuraman; Mukhopadhyay, Sibabrata; Majumder, Hemanta K

2013-12-15

Lignans are diphenyl propanoids with vast range of biological activities. The present study provides an important insight into the anti-leishmanial activities of two lignan glycosides, viz. lyoniside and saracoside. These compounds inhibit catalytic activities of topoisomerase IB (LdTopIB) of Leishmania donovani in non-competitive manner and stabilize the LdTopIB mediated cleavage complex formation both in vitro and in Leishmania promastigotes and subsequently inhibit the religation of cleaved strand. These two compounds not only poison LdTopIB but also can interact with the free enzyme LdTopIB. We have also shown that lyoniside and saracoside are cytotoxic to promastigotes and intracellular amastigotes. The protein-DNA complex formation leads to double strand breaks in DNA which ultimately triggers apoptosis-like cell death in the parasite. Along with their cytotoxicity towards sodium antimony gluconate (SAG) sensitive AG83 strain, their ability to kill SAG resistant GE1 strain makes these two compounds potential anti-leishmanial candidates. Not only they effectively kill L. donovani amastigotes inside macrophages in vitro, lyoniside and saracoside demonstrated strong anti-leishmanial efficacies in BALB/c mice model of leishmaniasis. Treatment with these lignan glycosides produce nitric oxide and reactive oxygen species which result in almost complete clearance of the liver and splenic parasite burden. These compounds do not inhibit human topoisomerase IB upto 200μM concentrations and had poor cytotoxic effect on uninfected cultured murine peritoneal macrophages upto 100μM concentrations. Taken together it can be concluded that these compounds can be developed into excellent therapeutic agent against deadly disease leishmaniasis. Copyright © 2013 Elsevier Inc. All rights reserved.

Immuno-informatics based approaches to identify CD8+ T cell epitopes within the Leishmania donovani 3-ectonucleotidase in cured visceral leishmaniasis subjects.

PubMed

Vijayamahantesh; Amit, Ajay; Dikhit, Manas R; Singh, Ashish K; Venkateshwaran, T; Das, V N R; Das, Pradeep; Bimal, Sanjiva

2017-06-01

Leishmaniases are vector-borne diseases for which no vaccine exists. These diseases are caused by the Leishmania species complex. Activation of the CD8 + T cell is crucial for protection against intracellular pathogens, and peptide antigens are attractive strategies for the precise activation of CD8 + T in vaccine development against intracellular infections. The traditional approach to mine the epitopes is an arduous task. However, with the advent of immunoinformatics, in silico epitope prediction tools are available to expedite epitope identification. In this study, we employ different immunoinformatics tools to predict CD8 + T cell specific 9 mer epitopes presented by HLA-A*02 and HLA-B40 within the highly conserved 3'-ectonucleotidase of Leishmania donovani. We identify five promiscuous epitopes, which have no homologs in humans, theoretically cover 85% of the world's population and are highly conserved (100%) among Leishmania species. Presentation of selected peptides was confirmed by T2 cell line based HLA-stabilization assay, and three of them were found to be strong binders. The in vitro peptide stimulation of peripheral blood mononuclear cells (PBMC) from cured HLA-A02 + visceral leishmaniasis (VL) subjects produced significantly higher IFN-γ, IL-2 and IL-12 compared to no peptide control healthy subjects. Further, CD8 + cells from treated VL subjects produced significantly higher intracellular IFN-γ, lymphocyte proliferation and cytotoxic activity against selected peptides from the PBMCs of treated HLA-A02 + VL subjects. Thus, the CD8 + T cell specific epitopes shown in this study will speed up the development of polytope vaccines for leishmaniasis. Copyright © 2017. Published by Elsevier Masson SAS.

Prevalence and risk factors associated with Leishmania infection in Trang Province, southern Thailand.

PubMed

Manomat, Jipada; Leelayoova, Saovanee; Bualert, Lertwut; Tan-Ariya, Peerapan; Siripattanapipong, Suradej; Mungthin, Mathirut; Naaglor, Tawee; Piyaraj, Phunlerd

2017-11-01

Autochthonous cutaneous and visceral leishmaniasis (VL) caused by Leishmania martiniquensis and Leishmania siamensis have been considered emerging infectious diseases in Thailand. The disease burden is significantly underestimated, especially the prevalence of Leishmania infection among HIV-positive patients. A cross-sectional study was conducted to determine the prevalence and risk factors associated with Leishmania infection among patients with HIV/AIDS living in Trang province, southern Thailand, between 2015 and 2016. Antibodies against Leishmania infection were assayed using the direct agglutination test (DAT). DNA of Leishmania was detected by ITS1-PCR using the buffy coat. Species of Leishmania were also identified. Of 724 participants, the prevalence of Leishmania infection was 25.1% (182/724) using either DAT or PCR assays. Seroprevalence of Leishmania infection was 18.5% (134/724), while Leishmania DNA detected by the PCR method was 8.4% (61/724). Of these, 24.9% (180/724) were asymptomatic, whereas 0.3% (2/724) were symptomatic VL and VL/CL (cutaneous leishmaniasis). At least five species were identified: L. siamensis, L. martiniquensis, L. donovani complex, L. lainsoni, and L. major. Multivariate analysis showed that CD4+ levels <500 cells/μL and living in stilt houses were independently associated with Leishmania infection. Those who were PCR positive for Leishmania DNA were significantly associated with a detectable viral load, whereas non-injection drug use (NIDU) and CD4+ levels <500 cells/μL were potential risk factors of Leishmania seropositivity. A magnitude of the prevalence of underreporting Leishmania infection among Thai patients with HIV was revealed in this study. Effective public health policy to prevent and control disease transmission is urgently needed.

Inhibition of fumarate reductase in Leishmania major and L. donovani by chalcones.

PubMed

Chen, M; Zhai, L; Christensen, S B; Theander, T G; Kharazmi, A

2001-07-01

Our previous studies have shown that chalcones exhibit potent antileishmanial and antimalarial activities in vitro and in vivo. Preliminary studies showed that these compounds destroyed the ultrastructure of Leishmania parasite mitochondria and inhibited the respiration and the activity of mitochondrial dehydrogenases of Leishmania parasites. The present study was designed to further investigate the mechanism of action of chalcones, focusing on the parasite respiratory chain. The data show that licochalcone A inhibited the activity of fumarate reductase (FRD) in the permeabilized Leishmania major promastigote and in the parasite mitochondria, and it also inhibited solubilized FRD and a purified FRD from L. donovani. Two other chalcones, 2,4-dimethoxy-4'-allyloxychalcone (24m4ac) and 2,4-dimethoxy-4'-butoxychalcone (24mbc), also exhibited inhibitory effects on the activity of solubilized FRD in L. major promastigotes. Although licochalcone A inhibited the activities of succinate dehydrogenase (SDH), NADH dehydrogenase (NDH), and succinate- and NADH-cytochrome c reductases in the parasite mitochondria, the 50% inhibitory concentrations (IC(50)) of licochalcone A for these enzymes were at least 20 times higher than that for FRD. The IC(50) of licochalcone A for SDH and NDH in human peripheral blood mononuclear cells were at least 70 times higher than that for FRD. These findings indicate that FRD, one of the enzymes of the parasite respiratory chain, might be the specific target for the chalcones tested. Since FRD exists in the Leishmania parasite and does not exist in mammalian cells, it could be an excellent target for antiprotozoal drugs.

Inhibition of Fumarate Reductase in Leishmania major and L. donovani by Chalcones

PubMed Central

Chen, Ming; Zhai, Lin; Christensen, Søren Brøgger; Theander, Thor G.; Kharazmi, Arsalan

2001-01-01

Our previous studies have shown that chalcones exhibit potent antileishmanial and antimalarial activities in vitro and in vivo. Preliminary studies showed that these compounds destroyed the ultrastructure of Leishmania parasite mitochondria and inhibited the respiration and the activity of mitochondrial dehydrogenases of Leishmania parasites. The present study was designed to further investigate the mechanism of action of chalcones, focusing on the parasite respiratory chain. The data show that licochalcone A inhibited the activity of fumarate reductase (FRD) in the permeabilized Leishmania major promastigote and in the parasite mitochondria, and it also inhibited solubilized FRD and a purified FRD from L. donovani. Two other chalcones, 2,4-dimethoxy-4′-allyloxychalcone (24m4ac) and 2,4-dimethoxy-4′-butoxychalcone (24mbc), also exhibited inhibitory effects on the activity of solubilized FRD in L. major promastigotes. Although licochalcone A inhibited the activities of succinate dehydrogenase (SDH), NADH dehydrogenase (NDH), and succinate- and NADH-cytochrome c reductases in the parasite mitochondria, the 50% inhibitory concentrations (IC50) of licochalcone A for these enzymes were at least 20 times higher than that for FRD. The IC50 of licochalcone A for SDH and NDH in human peripheral blood mononuclear cells were at least 70 times higher than that for FRD. These findings indicate that FRD, one of the enzymes of the parasite respiratory chain, might be the specific target for the chalcones tested. Since FRD exists in the Leishmania parasite and does not exist in mammalian cells, it could be an excellent target for antiprotozoal drugs. PMID:11408218

Characterization of Leishmania isolates from Nepalese patients with visceral leishmaniasis.

PubMed

Pandey, Kishor; Yanagi, Testuo; Pandey, Basu Dev; Mallik, Arun Kumar; Sherchand, Jeevan Bahadur; Kanbara, Hiroji

2007-05-01

In Nepal, visceral leishmaniasis (VL) is endemic in 13 districts of the central and eastern regions. A total of 166 bone-marrow aspirates were obtained from patients with suspected VL. Ninety-seven were identified as positive by microscopy, and 29 of those were successfully isolated and cultured. We characterized these isolates by molecular analysis and by their ability to infect mice. PCR-restriction fragment length polymorphism analysis of the mini-exon and the cysteine proteinase b gene showed that all isolates were Leishmania donovani, and the restriction pattern of the Nepalese isolates corresponded to the standard Indian strain of L. donovani but differed from that of the Kenyan strain. The single-strand conformation polymorphism analysis of ribosomal internal transcribed spacer showed no genetic heterogeneity within Nepalese isolates. Intraperitoneal inoculation with the promastigotes of all isolates resulted in amastigote proliferation in the spleen of 20 nude mice, of which ten isolates were highly infective, and ten were moderately infective, including one BALB/c mouse. Of the 20 amastigotes isolated from the spleen of nude mice, only the ten highly infective isolates infected BALB/c mice, of which, two isolates were considered to have low infectivity, three isolates were considered to be moderately infective, and five isolates were considered to be highly infective.

Canine Visceral Leishmaniasis, United States and Canada, 2000–2003

PubMed Central

Duprey, Zandra H.; Steurer, Francis J.; Rooney, Jane A.; Kirchhoff, Louis V.; Jackson, Joan E.; Rowton, Edgar D.

2006-01-01

Visceral leishmaniasis, caused by protozoa of the genus Leishmania donovani complex, is a vectorborne zoonotic infection that infects humans, dogs, and other mammals. In 2000, this infection was implicated as causing high rates of illness and death among foxhounds in a kennel in New York. A serosurvey of >12,000 foxhounds and other canids and 185 persons in 35 states and 4 Canadian provinces was performed to determine geographic extent, prevalence, host range, and modes of transmission within foxhounds, other dogs, and wild canids and to assess possible infections in humans. Foxhounds infected with Leishmania spp. were found in 18 states and 2 Canadian provinces. No evidence of infection was found in humans. The infection in North America appears to be widespread in foxhounds and limited to dog-to-dog mechanisms of transmission; however, if the organism becomes adapted for vector transmission by indigenous phlebotomines, the probability of human exposure will be greatly increased. PMID:16704782

Comprehensive Identification of mRNA-Binding Proteins of Leishmania donovani by Interactome Capture.

PubMed

Nandan, Devki; Thomas, Sneha A; Nguyen, Anne; Moon, Kyung-Mee; Foster, Leonard J; Reiner, Neil E

2017-01-01

Leishmania are unicellular eukaryotes responsible for leishmaniasis in humans. Like other trypanosomatids, leishmania regulate protein coding gene expression almost exclusively at the post-transcriptional level with the help of RNA binding proteins (RBPs). Due to the presence of polycystronic transcription units, leishmania do not regulate RNA polymerase II-dependent transcription initiation. Recent evidence suggests that the main control points in gene expression are mRNA degradation and translation. Protein-RNA interactions are involved in every aspect of RNA biology, such as mRNA splicing, polyadenylation, localization, degradation, and translation. A detailed picture of these interactions would likely prove to be highly informative in understanding leishmania biology and virulence. We developed a strategy involving covalent UV cross-linking of RBPs to mRNA in vivo, followed by interactome capture using oligo(dT) magnetic beads to define comprehensively the mRNA interactome of growing L. donovani amastigotes. The protein mass spectrometry analysis of captured proteins identified 79 mRNA interacting proteins which withstood very stringent washing conditions. Strikingly, we found that 49 of these mRNA interacting proteins had no orthologs or homologs in the human genome. Consequently, these may represent high quality candidates for selective drug targeting leading to novel therapeutics. These results show that this unbiased, systematic strategy has the promise to be applicable to study the mRNA interactome during various biological settings such as metabolic changes, stress (low pH environment, oxidative stress and nutrient deprivation) or drug treatment.

Metabolic Reprogramming During Purine Stress in the Protozoan Pathogen Leishmania donovani

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martin, Jessica L.; Yates, Phillip A.; Soysa, Radika

The ability of Leishmania to survive in their insect or mammalian host is dependent upon an ability to sense and adapt to changes in the microenvironment. However, little is known about the molecular mechanisms underlying the parasite response to environmental changes, such as nutrient availability. To elucidate nutrient stress response pathways in Leishmania donovani, we have used purine starvation as the paradigm. The salvage of purines from the host milieu is obligatory for parasite replication; nevertheless, purine-starved parasites can persist in culture without supplementary purine for over 3 months, indicating that the response to purine starvation is robust and engendersmore » parasite survival under conditions of extreme scarcity. To understand metabolic reprogramming during purine starvation we have employed global approaches. Whole proteome comparisons between purine-starved and purine-replete parasites over a 6-48 h span have revealed a temporal and coordinated response to purine starvation. Purine transporters and enzymes involved in acquisition at the cell surface are upregulated within a few hours of purine removal from the media, while other key purine salvage components are upregulated later in the time-course and more modestly. After 48 h, the proteome of purine-starved parasites is extensively remodeled and adaptations to purine stress appear tailored to deal with both purine deprivation and general stress. To probe the molecular mechanisms affecting proteome remodeling in response to purine starvation, comparative RNA-seq analyses, qRT-PCR, and luciferase reporter assays were performed on purine-starved versus purine-replete parasites. While the regulation of a minority of proteins tracked with changes at the mRNA level, for many regulated proteins it appears that proteome remodeling during purine stress occurs primarily via translational and/or post-translational mechanisms.« less

Differentiated human airway organoids to assess infectivity of emerging influenza virus.

PubMed

Zhou, Jie; Li, Cun; Sachs, Norman; Chiu, Man Chun; Wong, Bosco Ho-Yin; Chu, Hin; Poon, Vincent Kwok-Man; Wang, Dong; Zhao, Xiaoyu; Wen, Lei; Song, Wenjun; Yuan, Shuofeng; Wong, Kenneth Kak-Yuen; Chan, Jasper Fuk-Woo; To, Kelvin Kai-Wang; Chen, Honglin; Clevers, Hans; Yuen, Kwok-Yung

2018-06-26

Novel reassortant avian influenza H7N9 virus and pandemic 2009 H1N1 (H1N1pdm) virus cause human infections, while avian H7N2 and swine H1N1 virus mainly infect birds and pigs, respectively. There is no robust in vitro model for assessing the infectivity of emerging viruses in humans. Based on a recently established method, we generated long-term expanding 3D human airway organoids which accommodate four types of airway epithelial cells: ciliated, goblet, club, and basal cells. We report differentiation conditions which increase ciliated cell numbers to a nearly physiological level with synchronously beating cilia readily discernible in every organoid. In addition, the differentiation conditions induce elevated levels of serine proteases, which are essential for productive infection of human influenza viruses and low-pathogenic avian influenza viruses. We also established improved 2D monolayer culture conditions for the differentiated airway organoids. To demonstrate the ability of differentiated airway organoids to identify human-infective virus, 3D and 2D differentiated airway organoids are applied to evaluate two pairs of viruses with known distinct infectivity in humans, H7N9/Ah versus H7N2 and H1N1pdm versus an H1N1 strain isolated from swine (H1N1sw). The human-infective H7N9/Ah virus replicated more robustly than the poorly human-infective H7N2 virus; the highly human-infective H1N1pdm virus replicated to a higher titer than the counterpart H1N1sw. Collectively, we developed differentiated human airway organoids which can morphologically and functionally simulate human airway epithelium. These differentiated airway organoids can be applied for rapid assessment of the infectivity of emerging respiratory viruses to human. Copyright © 2018 the Author(s). Published by PNAS.

Development of Derivatives of 3, 3′-Diindolylmethane as Potent Leishmania donovani Bi-Subunit Topoisomerase IB Poisons

PubMed Central

Sengupta, Souvik; Mandal, Madhumita; Jaisankar, Parasuraman; D'Annessa, Ilda; Desideri, Alessandro; Majumder, Hemanta K.

2011-01-01

Background The development of 3, 3′-diindolyl methane (DIM) resistant parasite Leishmania donovani (LdDR50) by adaptation with increasing concentrations of the drug generates random mutations in the large and small subunits of heterodimeric DNA topoisomerase I of Leishmania (LdTOP1LS). Mutation of large subunit of LdTOP1LS at F270L is responsible for resistance to DIM up to 50 µM concentration. Methodology/Principal Findings In search of compounds that inhibit the growth of the DIM resistant parasite and inhibit the catalytic activity of mutated topoisomerase I (F270L), we have prepared three derivatives of DIM namely DPDIM (2,2′-diphenyl 3,3′-diindolyl methane), DMDIM (2,2′-dimethyl 3,3′-diindolyl methane) and DMODIM (5,5′-dimethoxy 3,3′-diindolyl methane) from parent compound DIM. All the compounds inhibit the growth of DIM resistant parasites, induce DNA fragmentation and stabilize topo1-DNA cleavable complex with the wild type and mutant enzyme. Conclusion The results suggest that the three derivatives of DIM can act as promising lead molecules for the generation of new anti-leishmanial agents. PMID:22174820

[Risk-adjusted assessment: late-onset infection in neonates].

PubMed

Gmyrek, Dieter; Koch, Rainer; Vogtmann, Christoph; Kaiser, Annette; Friedrich, Annette

2011-01-01

The weak point of the countrywide perinatal/neonatal quality surveillance is the ignorance of interhospital differences in the case mix of patients. As a result, this approach does not produce reliable benchmarking. The objective of this study was to adjust the result of the late-onset infection incidence of different hospitals according to their risk profile of patients by multivariate analysis. The perinatal/neonatal database of 41,055 newborns of the Saxonian quality surveillance from 1998 to 2004 was analysed. Based on 18 possible risk factors, a logistic regression model was used to develop a specific risk predictor for the quality indicator "late-onset infection". The developed risk predictor for the incidence of late-onset infection could be described by 4 of the 18 analysed risk factors, namely gestational age, admission from home, hypoxic ischemic encephalopathy and B-streptococcal infection. The AUC(ROC) value of this quality indicator was 83.3%, which demonstrates its reliability. The hospital ranking based on the adjusted risk assessment was very different from hospital rankings before this adjustment. The average correction of ranking position was 4.96 for 35 clinics. The application of the risk adjustment method proposed here allows for a more objective comparison of the incidence of the quality indicator "late onset infection" among different hospitals. Copyright © 2011. Published by Elsevier GmbH.

Up-regulation of cytosolic tryparedoxin in Amp B resistant isolates of Leishmania donovani and its interaction with cytosolic tryparedoxin peroxidase.

PubMed

Suman, Shashi S; Equbal, Asif; Zaidi, Amir; Ansari, Md Yousuf; Singh, Krishn Pratap; Singh, Kuljit; Purkait, Bidyut; Sahoo, Ganesh Chandra; Bimal, Sanjeeva; Das, Pradeep; Ali, Vahab

2016-02-01

Leishmania is a unicellular protozoan parasite which causes leishmaniasis, a neglected tropical disease. It possess a unique thiol metabolism comprising of several proteins among which, tryparedoxin (cTXN) and tryparedoxin peroxidase (cTXNPx), function in concert as oxidoreductases, utilizing trypanothione as a source of electrons to reduce the hydroperoxides produced by macrophages during infection. This detoxification pathway is unique and essential for the survival of Leishmania. Herein, we report the functional characterization of Leishmania donovani cTXN and its interaction with cTXNPx. The full length recombinant cTXN and cTXNPx proteins were purified in the native state and biochemical analysis showed that the cTXN-cTXNPx coupled system efficiently degraded hydrogen peroxide and tert-butyl hydroperoxide by transferring reducing equivalents from trypanothione. In silico investigation of the potential interaction between cTXN and cTXNPx proteins showed strong interaction of model structures with amino acids Ile109, Thr132, Glu107, Trp70, Trp39, Cys40 and His129 of Ld-cTXN and Thr54, Lys93, Arg128 and Asn152 of Ld-cTXNPx predicted to be involved in interaction. Moreover, co-purification, pull down assay and immunoprecipitation studies confirmed the interaction between Ld-cTXN and Ld-cTXNPx proteins. In addition, for the first time, we demonstrated at the translational level that Ld-cTXN protein is upregulated in Amp B resistant isolates accompanied by enhanced peroxidase activity, as compared to sensitive strains. Thus, our results show that Ld-cTXN and Ld-cTXNPx proteins acts in concert by physical interaction to form a strong peroxide stress detoxification system in Leishmania and their upregulation in Amp B resistant isolates imparts better stress tolerance, and hence fitter pathogens, as compared to sensitive strains. Copyright © 2015 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

Leishmania donovani pteridine reductase 1: comparative protein modeling and protein-ligand interaction studies of the leishmanicidal constituents isolated from the fruits of Piper longum.

PubMed

Sahi, Shakti; Tewatia, Parul; Ghosal, Sabari

2012-12-01

Visceral leishmaniasis or kala-azar is caused by the dimorphic parasite Leishmania donovani in the Indian subcontinent. Treatment options for kala-azar are currently inadequate due to various limitations. Currently, drug discovery for leishmaniases is oriented towards rational drug design; the aim is to identify specific inhibitors that target particular metabolic activities as a possible means of controlling the parasites without affecting the host. Leishmania salvages pteridin from its host and reduces it using pteridine reductase 1 (PTR1, EC 1.5.1.33), which makes this reductase an excellent drug target. Recently, we identified six alkamides and one benzenoid compound from the n-hexane fraction of the fruit of Piper longum that possess potent leishmanicidal activity against promastigotes as well as axenic amastigotes. Based on a homology model derived for recombinant pteridine reductase isolated from a clinical isolate of L. donovani, we carried out molecular modeling and docking studies with these compounds to evaluate their binding affinity. A fairly good agreement between experimental data and the results of molecular modeling investigation of the bioactive and inactive compounds was observed. The amide group in the conjugated alkamides and the 3,4-methylenedioxystyrene moiety in the benzenoid compound acts as heads and the long aliphatic chain acts as a tail, thus playing important roles in the binding of the inhibitor to the appropriate position at the active site. The remarkably high activity of a component containing piperine and piperine isomers (3.36:1) as observed by our group prompted us to study the activities of all four isomers of piperine-piperine (2E,4E), isopiperine (2Z,4E), isochavicine (2E,4Z), and chavicine (2Z,4Z)-against LdPTR1. The maximum inhibitory effect was demonstrated by isochavicine. The identification of these predicted inhibitors of LdPTR1 allowed us to build up a stereoview of the structure of the binding site in relation to

Leishmania cell surface prohibitin: role in host-parasite interaction.

PubMed

Jain, Rohit; Ghoshal, Angana; Mandal, Chitra; Shaha, Chandrima

2010-04-01

Proteins selectively upregulated in infective parasitic forms could be critical for disease pathogenesis. A mammalian prohibitin orthologue is upregulated in infective metacyclic promastigotes of Leishmania donovani, a parasite that causes visceral leishmaniasis. Leishmania donovani prohibitin shares 41% similarity with mammalian prohibitin and 95-100% within the genus. Prohibitin is concentrated at the surface of the flagellar and the aflagellar pole, the aflagellar pole being a region through which host-parasite interactions occur. Prohibitin is attached to the membrane through a GPI anchor. Overexpression of wild-type prohibitin increases protein surface density resulting in parasites with higher infectivity. However, parasites overexpressing a mutant prohibitin with an amino acid substitution at the GPI anchor site to prevent surface expression through GPI-link show lesser surface expression and lower infective abilities. Furthermore, the presence of anti-prohibitin antibodies during macrophage-Leishmania interaction in vitro reduces infection. The cognate binding partner for Leishmania prohibitin on the host cell appears to be macrophage surface HSP70, siRNA mediated downregulation of which abrogates the capability of the macrophage to bind to parasites. Leishmania prohibitin is able to generate a strong humoral response in visceral leishmaniasis patients. The above observations suggest that prohibitin plays an important role in events leading to Leishmania-host interaction.

Screening and risk assessment for coronary artery disease in HIV infection: an unmet need.

PubMed

Nadel, J; Holloway, C J

2017-04-01

HIV infection is now considered a chronic, treatable disease, although treatment is associated with increased rates of coronary artery disease (CAD). Increased risk of CAD in HIV-infected patients has been associated with the inflammatory sequelae of the infection as well as the greater prevalence of cardiac risk factors in HIV-positive populations and the side effects of life-prolonging antiretroviral therapies. Patients with HIV infection now have a 1.5 to 2-fold greater risk of developing CAD compared with noninfected individuals, raising the independent risk of CAD in HIV infection to levels similar to those in diabetes. Despite this increased risk, screening and other adjuvant assessment tools are lacking. In this paper we explore the current climate of CAD in the contemporary HIV-infected population and look at the tools used in the assessment and management of patients as well as the limitations of these approaches for this at-risk population group. © 2016 British HIV Association.

Testing Experimental Compounds against American Cutaneous and Mucocutaneous Leishmaniasis

DTIC Science & Technology

1982-06-01

synthesize large amounts of plasma membrane ergosterol in serum-free media (26). Ketoconazole and miconazole actively disrupt ergosterol synthesis in a...walls cross- * react with L. donovani (40), it was thought that immunostimula- tion of a htst with BCG prior to infection with L. mexicana ama- zonensis

Role of remote sensing, geographical information system (GIS) and bioinformatics in kala-azar epidemiology

PubMed Central

Bhunia, Gouri Sankar; Dikhit, Manas Ranjan; Kesari, Shreekant; Sahoo, Ganesh Chandra; Das, Pradeep

2011-01-01

Visceral leishmaniasis or kala-azar is a potent parasitic infection causing death of thousands of people each year. Medicinal compounds currently available for the treatment of kala-azar have serious side effects and decreased efficacy owing to the emergence of resistant strains. The type of immune reaction is also to be considered in patients infected with Leishmania donovani (L. donovani). For complete eradication of this disease, a high level modern research is currently being applied both at the molecular level as well as at the field level. The computational approaches like remote sensing, geographical information system (GIS) and bioinformatics are the key resources for the detection and distribution of vectors, patterns, ecological and environmental factors and genomic and proteomic analysis. Novel approaches like GIS and bioinformatics have been more appropriately utilized in determining the cause of visearal leishmaniasis and in designing strategies for preventing the disease from spreading from one region to another. PMID:23554714

COMPARISON OF TISSUE CULTURE AND ANIMAL MODELS FOR ASSESSMENT OF CRYPTOSPRIDIUM PARVUM INFECTION

EPA Science Inventory

Data from three different disinfection studies using both cell culture and mouse infectivity to assess Cryptosporidium parvum inactivation were evaluated in a total of 35 comparison including process controls and treated samples. C. parvum infectivity in the in vitro FDM-MPN assa...

Leishmania infections in Austrian soldiers returning from military missions abroad: a cross-sectional study.

PubMed

Obwaller, A G; Köhsler, M; Poeppl, W; Herkner, H; Mooseder, G; Aspöck, H; Walochnik, J

2018-01-12

The incidence of leishmaniasis is known to increase in conflict areas. The aims of this study were to determine the exposure to Leishmania species in Austrian soldiers returning from missions abroad and to assess possible risk factors. A retrospective explorative cross-sectional serologic study was conducted in 225 healthy Austrian soldiers returning from UN or EU peacekeeping missions in Syria, Lebanon and Bosnia and Herzegovina (BIH). Sera were tested for anti-Leishmania antibodies using a commercial enzyme-linked immunosorbent assay. All positive individuals were screened for Leishmania DNA by PCR targeting the ITS1 region using EDTA blood samples. In total, 13.3% (30/225) of the individuals tested were either positive (8%, 18/225) or borderline (5.3%, 12/225) in the enzyme-linked immunosorbent assay, with the highest seroprevalence in soldiers returning from Syria (17.8%, 18/101; 12 positive, six borderline), second from Lebanon (11.1%, 7/63; four positive, three borderline) and lowest from BIH (8.2%, 5/61; two positive, three borderline). Ten soldiers returning from Syria and one from BIH were also positive for Leishmania DNA. Six of these were identified as Leishmania donovani/infantum complex, two as L. tropica and another three as mixed infections by DNA sequencing. Epidemiologic data were collected via a questionnaire, and seropositivity was correlated with a history of insect bites that took a long time to heal (odds ratio, 5.33; 95% confidence interval, 1.23-23.04; p 0.025). Although pretravel serologic data were not available in this study, the exposure of soldiers to Leishmania spp. during their missions can be assumed to be considerable. Because even asymptomatic infections may resurge in case of emerging immunodeficiencies, adequate prevention measures seem important. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

First evidence of Leishmania infection in European brown hare (Lepus europaeus) in Greece: GIS analysis and phylogenetic position within the Leishmania spp.

PubMed

Tsokana, C N; Sokos, C; Giannakopoulos, A; Mamuris, Z; Birtsas, P; Papaspyropoulos, K; Valiakos, G; Spyrou, V; Lefkaditis, M; Chatzopoulos, D C; Kantere, M; Manolakou, K; Touloudi, A; Burriel, A Rodi; Ferroglio, E; Hadjichristodoulou, C; Billinis, C

2016-01-01

Although the existence of a sylvatic transmission cycle of Leishmania spp., independent from the domestic cycle, has been proposed, data are scarce on Leishmania infection in wild mammals in Greece. In this study, we aimed to investigate the presence of Leishmania infection in the European brown hare in Greece, to infer the phylogenetic position of the Leishmania parasites detected in hares in Greece, and to identify any possible correlation between Leishmania infection in hares with environmental parameters, using the geographical information system (GIS). Spleen samples from 166 hares were tested by internal transcribed spacer-1 (ITS-1)-nested PCR for the detection of Leishmania DNA. Phylogenetic analysis was performed on Leishmania sequences from hares in Greece in conjunction with Leishmania sequences from dogs in Greece and 46 Leishmania sequences retrieved from GenBank. The Leishmania DNA prevalence in hares was found to be 23.49 % (95 % confidence interval (CI) 17.27-30.69). The phylogenetic analysis confirmed that the Leishmania sequences from hares in Greece belong in the Leishmania donovani complex. The widespread Leishmania infection in hares should be taken into consideration because under specific circumstances, this species can act as a reservoir host. This study suggests that the role of wild animals, including hares, in the epidemiology of Leishmania spp. in Greece deserves further elucidation.

Assessing quality of life-shortening Wolbachia-infected Aedes aegypti mosquitoes in the field based on capture rates and morphometric assessments

PubMed Central

2014-01-01

Background Recent releases have been carried out with Aedes aegypti mosquitoes infected with the wMelPop mosquito cell-line adapted (wMelPop-CLA) strain of Wolbachia. This infection introduced from Drosophila provides strong blockage of dengue and other arboviruses but also has large fitness costs in laboratory tests. The releases were used to evaluate the fitness of released infected mosquitoes, and (following termination of releases) to test for any effects of wMelPop-CLA on wing size and shape when mosquitoes were reared under field conditions. Methods We monitored gravid females via double sticky traps to assess the reproductive success of wMelPop-CLA-infected females and also sampled the overall mosquito population post-release using Biogent Sentinel traps. Morphometric analyses were used to evaluate infection effects on wing shape as well as size. Results Oviposition success as assessed through double sticky traps was unrelated to size of released mosquitoes. However, released mosquitoes with lower wing loading were more successful. Furthermore, wMelPop-CLA-infected mosquitoes had 38.3% of the oviposition success of uninfected mosquitoes based on the predicted infection frequency after release. Environmental conditions affected wing shape and particularly size across time in uninfected mosquitoes, but not in naturally-reared wMelPop-CLA-infected mosquitoes. Although the overall size and shape do not differ between naturally-reared wMelPop-CLA-infected and uninfected mosquitoes, the infected mosquitoes tended to have smaller wings than uninfected mosquitoes during the cooler November in comparison to December. Conclusion These results confirm the lower fitness of wMelPop-CLA infection under field conditions, helping to explain challenges associated with a successful invasion by this strain. In the long run, invasion may depend on releasing strains carrying insecticide resistance or egg desiccation resistance, combined with an active pre-release population

Comparative Analysis of Cellular Immune Responses in Treated Leishmania Patients and Hamsters against Recombinant Th1 Stimulatory Proteins of Leishmania donovani

PubMed Central

Joshi, Sumit; Yadav, Narendra K.; Rawat, Keerti; Tripathi, Chandra Dev P.; Jaiswal, Anil K.; Khare, Prashant; Tandon, Rati; Baharia, Rajendra K.; Das, Sanchita; Gupta, Reema; Kushawaha, Pramod K.; Sundar, Shyam; Sahasrabuddhe, Amogh A.; Dube, Anuradha

2016-01-01

Our prior studies demonstrated that cellular response of T helper 1 (Th1) type was generated by a soluble antigenic fraction (ranging from 89.9 to 97.1 kDa) of Leishmania donovani promastigote, in treated Leishmania patients as well as hamsters and showed significant prophylactic potential against experimental visceral leishmaniasis (VL). Eighteen Th1 stimulatory proteins were identified through proteomic analysis of this subfraction, out of which 15 were developed as recombinant proteins. In the present work, we have evaluated these 15 recombinant proteins simultaneously for their comparative cellular responses in treated Leishmania patients and hamsters. Six proteins viz. elongation factor-2, enolase, aldolase, triose phosphate isomerase, protein disulfide isomerase, and p45 emerged as most immunogenic as they produced a significant lymphoproliferative response, nitric oxide generation and Th1 cytokine response in PBMCs and lymphocytes of treated Leishmania patients and hamsters respectively. The results suggested that these proteins may be exploited for developing a successful poly-protein and/or poly-epitope vaccine against VL. PMID:27047452

Verbascoside Inhibits Promastigote Growth and Arginase Activity of Leishmania amazonensis.

PubMed

Maquiaveli, Claudia C; Lucon-Júnior, João F; Brogi, Simone; Campiani, Giuseppe; Gemma, Sandra; Vieira, Paulo C; Silva, Edson R

2016-05-27

Verbascoside (1) is a phenylethanoid glycoside that has antileishmanial activity against Leishmania infantum and Leishmania donovani. In this study, we verified the activity of 1 on Leishmania amazonensis and arginase inhibition. Compound 1 showed an EC50 of 19 μM against L. amazonensis promastigotes and is a competitive arginase inhibitor (Ki = 0.7 μM). Docking studies were performed to assess the interaction of 1 with arginase at the molecular level. Arginase is an enzyme of the polyamine biosynthesis pathway that is important to parasite infectivity, and the results of our study suggest that 1 could be useful to develop new approaches for treating leishmaniasis.

Leishmania donovani Argininosuccinate Synthase Is an Active Enzyme Associated with Parasite Pathogenesis

PubMed Central

Lakhal-Naouar, Ines; Jardim, Armando; Strasser, Rona; Luo, Shen; Kozakai, Yukiko; Nakhasi, Hira L.; Duncan, Robert C.

2012-01-01

Background Gene expression analysis in Leishmania donovani (Ld) identified an orthologue of the urea cycle enzyme, argininosuccinate synthase (LdASS), that was more abundantly expressed in amastigotes than in promastigotes. In order to characterize in detail this newly identified protein in Leishmania, we determined its enzymatic activity, subcellular localization in the parasite and affect on virulence in vivo. Methodology/Principal Findings Two parasite cell lines either over expressing wild type LdASS or a mutant form (G128S) associated with severe cases of citrullinemia in humans were developed. In addition we also produced bacterially expressed recombinant forms of the same proteins. Our results demonstrated that LdASS has argininosuccinate synthase enzymatic activity that is abolished using an ASS specific inhibitor (MDLA: methyl-D-L-Aspartic acid). However, the mutant form of the protein is inactive. We demonstrate that though LdASS has a glycosomal targeting signal that binds the targeting apparatus in vitro, only a small proportion of the total cellular ASS is localized in a vesicle, as indicated by protection from protease digestion of the crude organelle fraction. The majority of LdASS was found to be in the cytosolic fraction that may include large cytosolic complexes as indicated by the punctate distribution in IFA. Surprisingly, comparison to known glycosomal proteins by IFA revealed that LdASS was located in a structure different from the known glycosomal vesicles. Significantly, parasites expressing a mutant form of LdASS associated with a loss of in vitro activity had reduced virulence in vivo in BALB/c mice as demonstrated by a significant reduction in the parasite load in spleen and liver. Conclusion/Significance Our study suggests that LdASS is an active enzyme, with unique localization and essential for parasite survival and growth in the mammalian host. Based on these observations LdASS could be further explored as a potential drug target

In vitro selection of miltefosine resistance in promastigotes of Leishmania donovani from Nepal: genomic and metabolomic characterization.

PubMed

Shaw, C D; Lonchamp, J; Downing, T; Imamura, H; Freeman, T M; Cotton, J A; Sanders, M; Blackburn, G; Dujardin, J C; Rijal, S; Khanal, B; Illingworth, C J R; Coombs, G H; Carter, K C

2016-03-01

In this study, we followed the genomic, lipidomic and metabolomic changes associated with the selection of miltefosine (MIL) resistance in two clinically derived Leishmania donovani strains with different inherent resistance to antimonial drugs (antimony sensitive strain Sb-S; and antimony resistant Sb-R). MIL-R was easily induced in both strains using the promastigote-stage, but a significant increase in MIL-R in the intracellular amastigote compared to the corresponding wild-type did not occur until promastigotes had adapted to 12.2 μM MIL. A variety of common and strain-specific genetic changes were discovered in MIL-adapted parasites, including deletions at the LdMT transporter gene, single-base mutations and changes in somy. The most obvious lipid changes in MIL-R promastigotes occurred to phosphatidylcholines and lysophosphatidylcholines and results indicate that the Kennedy pathway is involved in MIL resistance. The inherent Sb resistance of the parasite had an impact on the changes that occurred in MIL-R parasites, with more genetic changes occurring in Sb-R compared with Sb-S parasites. Initial interpretation of the changes identified in this study does not support synergies with Sb-R in the mechanisms of MIL resistance, though this requires an enhanced understanding of the parasite's biochemical pathways and how they are genetically regulated to be verified fully. © 2015 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.

Fibrosis assessment in patients with chronic hepatitis B virus (HBV) infection

PubMed Central

Parikh, Pathik; Ryan, John D.

2017-01-01

Chronic hepatitis B virus (HBV) infection is a major cause of liver morbidity and mortality worldwide. While a proportion of the 250 million individuals chronically infected with HBV will not come to significant harm or require therapy, many others risk developing complications of the end-stage liver disease such as decompensated cirrhosis and hepatocellular carcinoma (HCC), without intervention. Due to the complex natural history of HBV infection, patients require an expert assessment to interpret biochemistry, viral serology and appropriately stage the disease, and to initiate monitoring and/or therapy where indicated. The detection and quantification of liver fibrosis is a key factor for disease management and prognostication for an individual with HBV. The reliance on invasive liver biopsy to stage disease is diminishing with the advent of robust non-invasive blood- and imaging-based algorithms which can reliably stage disease in many cases. These tests are now incorporated into International guidelines for HBV management and relied upon daily to inform clinical judgement. Both blood- and imaging-based approaches have advantages over liver biopsy, including minimal risks, lower cost, better patient acceptance and speed of results, while disadvantages include lower diagnostic accuracy in intermediate disease stages and variability with co-existing hepatic inflammation or steatosis. This review outlines the methods of fibrosis assessment in chronic HBV infection and focuses on the most commonly used blood- and imaging-based non-invasive tests, reviewing their diagnostic performance and applicability to patient care. PMID:28251119

Global status of visceral leishmanial infection among blood donors: A systematic review and meta-analysis.

PubMed

Asfaram, Shabnam; Fakhar, Mahdi; Soosaraei, Masoud; Hosseini Teshnizi, Saeed; Mardani, Ahmad; Banimostafavi, Elham Sadat; Ziaei Hezarjaribi, Hajar

2017-10-01

Transmission of Leishmania through transfusion has been reported from various Visceral leishmaniasis (VL) endemic areas of the world. The true burden of Leishmania infection in blood donors remains generally unknown. Thus, the present systematic review attempted to determine the global prevalence of Leishmania infection among blood donors. Data were extracted through five English and five Persian databases during the period from 1997 to 2016. Overall, 16 articles fulfilled the inclusion criteria and were used for data extraction in this systematic review. In total, 13,743 blood donors from different regions of world were examined. The prevalence rate of Leishmania infection according to seropositivity obtained 7% (95%CI: 5%, 8%). The lowest and the highest prevalence were related to Bangladesh 0.25% (95%CI: 0.0%, 1.0%) and Brazil, 16% (95%CI: 12%, 19%). Seroprevalence rate of leishmaniasis among females was more (4.60%) than males. Of 15 studies included in the meta-analysis, the pooled prevalence rate of molecular tests was obtained 2% (95%CI: 1%, 3%) in which Iran and Spain had the lowest and the highest prevalence, 0.05% and 7%, respectively. Our analysis showed that L. infantum was more common than L. donovani as etiological agent of VL among all donors. Our data confirms the presence of asymptomatic carriers of VL in endemic areas and supplies as an attentive to the likelihood of these carriers acting as blood donors. Moreover, we conclude that molecular tests for screening in asymptomatic blood donor provide an accurate estimate of the rate of infection over serological tests. Copyright © 2017 Elsevier Ltd. All rights reserved.

An assessment of WISC-IIIUK on children with HIV infection.

PubMed

James, Anu Nikitha; Ittyerah, Miriam

2016-10-01

The Wechsler Intelligence Scale for Children - Third Edition UK test was administered to groups of children between the ages of 6 and 12 years with vertically transmitted HIV infection (n = 70) and a control group who were not infected by the virus (n = 70). The study was conducted in India. The two groups were matched for general verbal abilities, age and gender. The children were assessed for Verbal IQ, Performance IQ and Full-Scale IQ. The Verbal Comprehension Index, Perceptual Organization Index and Freedom from Distractibility Index were also obtained. A three-factor analysis of variance disclosed that school-age children with vertically transmitted HIV infection notched below in the areas of Verbal IQ, Performance IQ, Full-Scale IQ, Verbal Comprehension Index, Perceptual Organization Index and Freedom from Distractibility Index when collated with normal uninfected cohorts. Findings are discussed in the light of both theoretical and clinical implications. © The Author(s) 2015.

Leishmaniasis

DTIC Science & Technology

1993-01-01

disease are animals such as desert rats, sloths, horses, rodents, foxes and dogs . 14. SUMrCT TERMS IS. NUMBER OF PAGES Leishmaniasis, sandflies... Ketoconazole and Allopurinol)................................... 311 E. Topical Agents (Paromomycin) ...................... 313 F. Liposomes...panamensis), horses (L. braziliensis), rodents (L. mexicana); and foxes and dogs (L. donovani). In India, inadequately treated visceral infection may

Assessment of Risk Factors of Helicobacter Pylori Infection and Peptic Ulcer Disease

PubMed Central

Mhaskar, Rahul S; Ricardo, Izurieta; Azliyati, Azizan; Laxminarayan, Rajaram; Amol, Bapaye; Santosh, Walujkar; Boo, Kwa

2013-01-01

Background: Helicobacter pylori (H. pylori) infection is a risk factor for peptic ulcer. There have been no studies addressing environmental and dietary risk factors in western India. We conducted a case control study enrolling peptic ulcer patients in Pune, India. Materials and Methods: Risk factors for peptic ulcer and H. pylori infection were assessed in a participant interview. H. pylori status was assessed from stool by monoclonal antigen detection. Results: We enrolled 190 peptic ulcer, 35 stomach cancer patients, and 125 controls. Fifty-one percent (180/350) of the participants were infected with H. pylori. Lower socioeconomic status (SES) [odds ratio (OR): 1.10, 95% confidence interval (CI): 1.02–1.39], meat consumption (OR: 2.35, 95% CI: 1.30–4.23), smoking (OR: 2.23, 95% CI: 1.24–4.02), eating restaurant food (OR: 3.77, 95% CI: 1.39–10.23), and drinking nonfiltered or nonboiled water (OR: 1.05, 95% CI: 1.01–1.23) were risk factors for H. pylori infection. H. pylori infection (OR: 1.70, 95% CI: 1.03–2.89), meat (OR: 1.10, 95% CI: 1.02-1.75), fish (OR: 1.05, 95% CI: 1.02–1.89) consumption, and a family history of ulcer (OR: 1.20, 95% CI: 1.08–1.60) were risk factors for peptic ulcer. Consumption of chili peppers (OR: 0.20, 95% CI: 0.10–0.37) and parasite infestation (OR: 0.44, 95% CI: 0.24–0.80) were protective against H. pylori infection. Conclusion: H. pylori infection is associated with peptic ulcer. Lower SES, consumption of restaurant food, meat, nonfiltered water, and smoking are risk factors for H. pylori. Consumption of meat, fish, and a family history of peptic ulcer are risk factors for peptic ulcer. Consumption of chili peppers and concurrent parasite infestation appear to be protective against H. pylori. PMID:23853433

Infection prevention needs assessment in Colorado hospitals: rural and urban settings.

PubMed

Reese, Sara M; Gilmartin, Heather; Rich, Karen L; Price, Connie S

2014-06-01

The purpose of our study was to conduct a needs assessment for infection prevention programs in both rural and urban hospitals in Colorado. Infection control professionals (ICPs) from Colorado hospitals participated in an online survey on training, personnel, and experience; ICP time allocation; and types of surveillance. Responses were evaluated and compared based on hospital status (rural or urban). Additionally, rural ICPs participated in an interview about resources and training. Surveys were received from 62 hospitals (77.5% response); 33 rural (75.0% response) and 29 urban (80.6% response). Fifty-two percent of rural ICPs reported multiple job responsibilities compared with 17.2% of urban ICPs. Median length of experience for rural ICPs was 4.0 years compared with 11.5 years for urban ICPs (P = .008). Fifty-one percent of rural ICPs reported no access to infectious disease physicians (0.0% urban) and 81.8% of rural hospitals reported no antimicrobial stewardship programs (31.0% urban). Through the interviews it was revealed that priorities for rural ICPs were training and communication. Our study revealed numerous differences between infection prevention programs in rural versus urban hospitals. An infection prevention outreach program established in Colorado could potentially address the challenges faced by rural hospital infection prevention departments. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

Deprivation of L-Arginine Induces Oxidative Stress Mediated Apoptosis in Leishmania donovani Promastigotes: Contribution of the Polyamine Pathway

PubMed Central

Mandal, Abhishek; Das, Sushmita; Roy, Saptarshi; Ghosh, Ayan Kumar; Sardar, Abul Hasan; Verma, Sudha; Saini, Savita; Singh, Ruby; Abhishek, Kumar; Kumar, Ajay; Mandal, Chitra; Das, Pradeep

2016-01-01

The growth and survival of intracellular parasites depends on the availability of extracellular nutrients. Deprivation of nutrients viz glucose or amino acid alters redox balance in mammalian cells as well as some lower organisms. To further understand the relationship, the mechanistic role of L-arginine in regulation of redox mediated survival of Leishmania donovani promastigotes was investigated. L-arginine deprivation from the culture medium was found to inhibit cell growth, reduce proliferation and increase L-arginine uptake. Relative expression of enzymes, involved in L-arginine metabolism, which leads to polyamine and trypanothione biosynthesis, were downregulated causing decreased production of polyamines in L-arginine deprived parasites and cell death. The resultant increase in reactive oxygen species (ROS), due to L-arginine deprivation, correlated with increased NADP+/NADPH ratio, decreased superoxide dismutase (SOD) level, increased lipid peroxidation and reduced thiol content. A deficiency of L-arginine triggered phosphatidyl serine externalization, a change in mitochondrial membrane potential, release of intracellular calcium and cytochrome-c. This finally led to DNA damage in Leishmania promastigotes. In summary, the growth and survival of Leishmania depends on the availability of extracellular L-arginine. In its absence the parasite undergoes ROS mediated, caspase-independent apoptosis-like cell death. Therefore, L-arginine metabolism pathway could be a probable target for controlling the growth of Leishmania parasites and disease pathogenesis. PMID:26808657

[Clinical assessment of occult infections in children].

PubMed

Sporisević, L; Bajraktarević, A; Begić, Z

2000-01-01

Children's occult infections are characterised presenting pathogenic bacteries in blood of children in age 3 to 36 months, but they are good general aspect and orderly immunologic status and they don't have signs of focal infection. Manifestation of occult infections determined: age of child, increasing bodies temperature, testsphysical observance and clinical-biochemistry tests. Prevalence of manifestation occult infections is 3-8%, but they manifest ni a form occult bacteremia, occult pneumonia nad occult urinary infection. Methodic, systematic admission and adequate clinical-biochemical monitoring, we minimise sequeles of occult infections. Risk of serious sequeles at occult infections is importantly decreasing by epidemiological changes that it rises by using vaccination against Haemophilus influenzae and Streptococcus pneumoniae is leading ethiological source. Many contraversal opinions are presented in glance of therapeutic strategy at children's occult infection. Future of solutions at many hesitations ni context diagnosis and therapy of occult infections is established in using recent detectional tests /pneumococcus PCR, plasmas tumor reaction, interleukin lâ/ and preventive intervetions activities /conjugated pneumococcus vaccination/.

A comparative evaluation of efficacy of chemotherapy, immunotherapy and immunochemotherapy in visceral leishmaniasis-an experimental study.

PubMed

Joshi, Jyoti; Malla, Nancy; Kaur, Sukhbir

2014-08-01

Visceral leishmaniasis (VL) represents the second most challenging infectious disease worldwide, leading to nearly 500,000 new cases and 60,000 deaths annually. Ninety per cent of VL cases occur in five countries namely Bangladesh, India, Nepal, Sudan and Brazil. No licensed vaccine is available till date against any form of leishmaniasis. High toxicity and increasing resistance to the current chemotherapeutic regimens have further complicated the situation in VL endemic regions of the world. To combat this situation, immunochemotherapy can provide a solution. In the present study, an attempt has been made to assess the in vivo antileishmanial efficacy of chemotherapy, immunotherapy and immunochemotherapy with the use of a first generation antigen Killed Leishmania donovani (KLD) along with a standard drug sodium stibogluconate (SSG) and a newly tested antileishmanial cisplatin. Inbred BALB/c mice were infected with 10(7) promastigotes/0.1 ml of Leishmania donovani. A month after infection, these animals were given specific immunotherapy (KLD/KLD+MPL-A) or chemotherapy (SSG/cisplatin) or immunochemotherapy (SSG+KLD/SSG+KLD+MPL-A/cisplatin+KLD/cisplatin+KLD+MPL-A). Animals were sacrificed on 1, 15 and 30(th) day post treatment. The efficacy of these combinations was assessed in terms of parasite load and by immunological investigations. Infected mice and normal mice served as controls. Results showed that combination of drug and KLD significantly reduced the parasite burden, enhanced the DTH (Delayed Type Hypersensitivity) responses, showed increased levels of IgG2a and decreased levels of IgG1 as compared to mice given chemotherapy or immunotherapy alone. Further maximum protection was provided by SSG+KLD+MPL-A and it was most effective as depicted by 98.5% reduction in parasite load, a potent increase in IFN-γ levels and a significant decrease in IL-10 and IL-4 levels thus skewing the immune response towards Th1 type. Hence, immunochemotherapy is more effective

Efficacy of Withania somnifera chemotypes NMITLI - 101R, 118R and Withaferin A against experimental visceral leishmaniasis.

PubMed

Tripathi, C D P; Gupta, R; Kushawaha, P K; Mandal, C; Misra Bhattacharya, S; Dube, A

2014-06-01

The immunoprophylactic and therapeutic potentials of root extracts of Withania somnifera chemotypes (NMITLI-118, NMITLI-101) and pure withanolide-withaferin A was investigated against Leishmania donovani infection in hamsters. The naive animals, fed orally with immunostimulatory doses of chemotypes 101R, 118R (10 and 3 mg/kg) and withaferin A (9 and 3 mg/kg) for five consecutive days and challenged with Leishmania parasites on day 6, were euthanized on days 30 and 45 p.c. for the assessment of parasite clearance, real-time analysis of mRNAs of Th1/Th2 cytokines (IFN-γ, IL-12, TNF-α, iNOS/IL-4, IL-10 and TGF-β), NO production, reactive oxygen species (ROS) generation, lymphocyte transformation test and antibody responses. By day 45 p.c., there was a significant increase in the mRNA expression of iNOS, IFN-γ, IL-12 and TNF-α but decrease in IL-4, IL-10 and TGF-β, an enhanced Leishmania-specific LTT response as well as ROS, NO and antileishmanial IgG2 levels in 101R-treated hamsters followed by 118R- and withaferin A-treated ones, respectively. When these chemotypes were given to L. donovani-infected hamsters at different doses, there was moderate therapeutic efficacy of chemotype 101R (~50%) at 30 mg/kg × 5 followed by the other two. The results established that the 101R is the most potential chemotype and can be evaluated for combination therapy along with available antileishmanials. © 2014 John Wiley & Sons Ltd.

Comparing probabilistic microbial risk assessments for drinking water against daily rather than annualised infection probability targets.

PubMed

Signor, R S; Ashbolt, N J

2009-12-01

Some national drinking water guidelines provide guidance on how to define 'safe' drinking water. Regarding microbial water quality, a common position is that the chance of an individual becoming infected by some reference waterborne pathogen (e.g. Cryptsporidium) present in the drinking water should < 10(-4) in any year. However the instantaneous levels of risk to a water consumer vary over the course of a year, and waterborne disease outbreaks have been associated with shorter-duration periods of heightened risk. Performing probabilistic microbial risk assessments is becoming commonplace to capture the impacts of temporal variability on overall infection risk levels. A case is presented here for adoption of a shorter-duration reference period (i.e. daily) infection probability target over which to assess, report and benchmark such risks. A daily infection probability benchmark may provide added incentive and guidance for exercising control over short-term adverse risk fluctuation events and their causes. Management planning could involve outlining measures so that the daily target is met under a variety of pre-identified event scenarios. Other benefits of a daily target could include providing a platform for managers to design and assess management initiatives, as well as simplifying the technical components of the risk assessment process.

A novel recombinant Leishmania donovani p45, a partial coding region of methionine aminopeptidase, generates protective immunity by inducing a Th1 stimulatory response against experimental visceral leishmaniasis.

PubMed

Gupta, Reema; Kushawaha, Pramod K; Tripathi, Chandra Dev Pati; Sundar, Shyam; Dube, Anuradha

2012-05-01

The development of a vaccine against visceral leishmaniasis (VL) conferring long-lasting immunity remains a challenge. Identification and proteomic characterization of parasite proteins led to the detection of p45, a member of the methionine aminopeptidase family. To our knowledge the present study is the first known report that describes the molecular and immunological characterization of p45. Recombinant Leishmania donovani p45 (rLdp45) induced cellular responses in cured hamsters and generated Th1-type cytokines from peripheral blood mononuclear cells of cured/endemic VL patients. Immunization with rLdp45 exerted considerable prophylactic efficacy (∼85%) supported by an increase in mRNA expression of iNOS, IFN-γ, TNF-α and IL-12 and decrease in TGF-β and IL-4, indicating its potential as a vaccine candidate against VL. Copyright © 2012. Published by Elsevier Ltd.

Fecal Microbiota Therapy for Clostridium difficile Infection: A Health Technology Assessment.

PubMed

2016-01-01

Fecal microbiota therapy is increasingly being used to treat patients with Clostridium difficile infection. This health technology assessment primarily evaluated the effectiveness and cost-effectiveness of fecal microbiota therapy compared with the usual treatment (antibiotic therapy). We performed a literature search using Ovid MEDLINE, Embase, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, CRD Health Technology Assessment Database, Cochrane Central Register of Controlled Trials, and NHS Economic Evaluation Database. For the economic review, we applied economic filters to these search results. We also searched the websites of agencies for other health technology assessments. We conducted a meta-analysis to analyze effectiveness. The quality of the body of evidence for each outcome was examined according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. Using a step-wise, structural methodology, we determined the overall quality to be high, moderate, low, or very low. We used a survey to examine physicians' perception of patients' lived experience, and a modified grounded theory method to analyze information from the survey. For the review of clinical effectiveness, 16 of 1,173 citations met the inclusion criteria. A meta-analysis of two randomized controlled trials found that fecal microbiota therapy significantly improved diarrhea associated with recurrent C. difficile infection versus treatment with vancomycin (relative risk 3.24, 95% confidence interval [CI] 1.85-5.68) (GRADE: moderate). While fecal microbiota therapy is not associated with a significant decrease in mortality compared with antibiotic therapy (relative risk 0.69, 95% CI 0.14-3.39) (GRADE: low), it is associated with a significant increase in adverse events (e.g., short-term diarrhea, relative risk 30.76, 95% CI 4.46-212.44; abdominal cramping, relative risk 14.81, 95% CI 2.07-105.97) (GRADE: low). For

[Development of HIV infection risk assessment tool for men who have sex with men based on Delphi method].

PubMed

Li, L L; Jiang, Z; Song, W L; Ding, Y Y; Xu, J; He, N

2017-10-10

Objective: To develop a HIV infection risk assessment tool for men who have sex with men (MSM) based on Delphi method. Methods: After an exhaustive literature review, we used Delphi method to determine the specific items and relative risk scores of the assessment tool through two rounds of specialist consultation and overall consideration of the opinions and suggestions of 17 specialists. Results: The positivity coefficient through first and second round specialist consultation was 100.0 % and 94.1 % , respectively. The mean of authority coefficients ( Cr ) was 0.86. Kendall's W coefficient of the specialist consultation was 0.55 for the first round consultation (χ(2)=84.426, P <0.001) and 0.46 for the second round consultation (χ(2)=65.734, P <0.001), respectively, suggesting that the specialists had similar opinions. The final HIV infection risk assessment tool for MSM has 8 items. Conclusions: The HIV infection risk assessment tool for MSM, developed under the Delphi method, can be used in the evaluation of HIV infection risk in MSM and individualized prevention and intervention. However, the reliability and validity of this risk assessment tool need to be further evaluated.

A quantitative risk assessment for the safety of carcase storage systems for scrapie infected farms.

PubMed

Adkin, A; Jones, D L; Eckford, R L; Edwards-Jones, G; Williams, A P

2014-10-01

To determine the risk associated with the use of carcase storage vessels on a scrapie infected farm. A stochastic quantitative risk assessment was developed to determine the rate of accumulation and fate of scrapie in a novel low-input storage system. For an example farm infected with classical scrapie, a mean of 10(3·6) Ovine Oral ID50 s was estimated to accumulate annually. Research indicates that the degradation of any prions present may range from insignificant to a magnitude of one or two logs over several months of storage. For infected farms, the likely partitioning of remaining prion into the sludge phase would necessitate the safe operation and removal of resulting materials from these systems. If complete mixing could be assumed, on average, the concentrations of infectivity are estimated to be slightly lower than that measured in placenta from infected sheep at lambing. This is the first quantitative assessment of the scrapie risk associated with fallen stock on farm and provides guidance to policy makers on the safety of one type of storage system and the relative risk when compared to other materials present on an infected farm. © 2014 Crown Copyright. Journal of Applied Microbiology © 2014 Society for Applied Microbiology This article is published with the permission of the Controller of HMSO and the Queen's Printer for Scotland.

ASSESSING THE COST BURDEN OF DENGUE INFECTION TO HOUSEHOLDS IN SEREMBAN, MALAYSIA.

PubMed

Mia, Md Shahin; Begum, Rawshan Ara; Er, A C; Pereira, Joy Jacqueline

2016-11-01

Dengue is endemic in all parts of Malaysia. However, there is limited data regarding the cost burden of this disease at household level. We aimed to examine the cost of dengue infection at the household level in Seremban District, Malaysia. This cost assessment can provide an insight to policy-makers about economic impact of dengue infection in order to guide and prioritize control strategies. The data were collected via interview. We evaluated120 previous dengue infection patients registered at the Tuanku Ja’afar Hospital, Seremban District, Malaysia. The average duration of dengue illness was 9.69 days. The average household days lost was 18.7; students lost an average of 6.3 days of school and patients and caregivers lost an average of 12.5 days of work. The mean total cost per case of dengue infection was estimated to be USD365.16 with the indirect cost being USD327.90 (89.8% of the total cost) and the direct cost being USD37.26 (10.2% of the total cost). Our findings suggest each episode of dengue infection imposes a significant financial burden at the household level in Seremban District, Malaysia; most of the burden being indirect cost. This cost needs to be factored into the overall cost to society of dengue infection. This data can inform policy makers when allocating resources to manage public health problems in Malaysia.

Noninvasive models for assessment of liver fibrosis in patients with chronic hepatitis B virus infection

PubMed Central

Zeng, Da-Wu; Dong, Jing; Liu, Yu-Rui; Jiang, Jia-Ji; Zhu, Yue-Yong

2016-01-01

There are approximately 240 million patients with chronic hepatitis B virus (HBV) infection worldwide. Up to 40% of HBV-infected patients can progress to liver cirrhosis, hepatocellular carcinoma or chronic end-stage liver disease during their lifetime. This, in turn, is responsible for around 650000 deaths annually worldwide. Repeated hepatitis flares may increase the progression of liver fibrosis, making the accurate diagnosis of the stage of liver fibrosis critical in order to make antiviral therapeutic decisions for HBV-infected patients. Liver biopsy remains the “gold standard” for diagnosing liver fibrosis. However, this technique has recently been challenged by the development of several novel noninvasive tests to evaluate liver fibrosis, including serum markers, combined models and imaging techniques. In addition, the cost and accessibility of imaging techniques have been suggested as additional limitations for invasive assessment of liver fibrosis in developing countries. Therefore, a noninvasive assessment model has been suggested to evaluate liver fibrosis, specifically in HBV-infected patients, owing to its high applicability, inter-laboratory reproducibility, wide availability for repeated assays and reasonable cost. The current review aims to present the status of knowledge in this new and exciting field, and to highlight the key points in HBV-infected patients for clinicians. PMID:27547009

Therapeutic immunization with radio-attenuated Leishmania parasites through i.m. route revealed protection against the experimental murine visceral leishmaniasis.

PubMed

Datta, Sanchita; Manna, Madhumita; Khanra, Supriya; Ghosh, Moumita; Bhar, Radhaballav; Chakraborty, Anindita; Roy, Syamal

2012-07-01

After our promising results from prophylactic and therapeutic study (i.p. route) with the radio-attenuated Leishmania donovani parasites against experimental murine visceral leishmaniasis, we prompted to check their therapeutic efficacy through i.m route. BALB/c mice were infected with highly virulent L. donovani parasites. After 75 days, mice were treated with gamma (γ)-irradiated parasites. A second therapeutic immunization was given after 15 days of first immunization. The protection against kala-azar was estimated with the reduction of Leishman-Donovan unit from spleen and liver that scored up to 80% and 93%, respectively, while a twofold increase in nitric oxide (NO) and reactive oxygen species (ROS) productions has been observed in the immunized groups of animals. These groups of mice also showed disease regression by skewing Th2 cytokines (IL-10) towards Th1 cytokine (IFN-γ) bias along with the increased generation of NO and ROS, while the infected control group of mice without such treatment surrendered to the disease. Establishment of Th1 ambience in the treated groups has also been supported from the measured antileishmanial antibody IgG subsets (IgG2a and IgG1) with higher anti-soluble Leishmania antigen-specific IgG2a titer. As seen in our previous studies, doses of attenuation by γ-radiation should be taken into serious consideration. Attenuation of parasites at 50 Gy of absorbed dose of gamma rays has not worked well. Thus, therapeutic use of L. donovani parasites radio-attenuated at particular doses can be exploited as a promising vaccine agent. Absence of any adjuvant may increase its acceptability as vaccine candidate further.

Fecal Microbiota Therapy for Clostridium difficile Infection: A Health Technology Assessment

PubMed Central

2016-01-01

Background Fecal microbiota therapy is increasingly being used to treat patients with Clostridium difficile infection. This health technology assessment primarily evaluated the effectiveness and cost-effectiveness of fecal microbiota therapy compared with the usual treatment (antibiotic therapy). Methods We performed a literature search using Ovid MEDLINE, Embase, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, CRD Health Technology Assessment Database, Cochrane Central Register of Controlled Trials, and NHS Economic Evaluation Database. For the economic review, we applied economic filters to these search results. We also searched the websites of agencies for other health technology assessments. We conducted a meta-analysis to analyze effectiveness. The quality of the body of evidence for each outcome was examined according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. Using a step-wise, structural methodology, we determined the overall quality to be high, moderate, low, or very low. We used a survey to examine physicians’ perception of patients’ lived experience, and a modified grounded theory method to analyze information from the survey. Results For the review of clinical effectiveness, 16 of 1,173 citations met the inclusion criteria. A meta-analysis of two randomized controlled trials found that fecal microbiota therapy significantly improved diarrhea associated with recurrent C. difficile infection versus treatment with vancomycin (relative risk 3.24, 95% confidence interval [CI] 1.85–5.68) (GRADE: moderate). While fecal microbiota therapy is not associated with a significant decrease in mortality compared with antibiotic therapy (relative risk 0.69, 95% CI 0.14–3.39) (GRADE: low), it is associated with a significant increase in adverse events (e.g., short-term diarrhea, relative risk 30.76, 95% CI 4.46–212.44; abdominal cramping, relative risk 14

Expression, purification, immunogenicity and protective efficacy of a recombinant nucleoside hydrolase from Leishmania donovani, a vaccine candidate for preventing cutaneous leishmaniasis.

PubMed

McAtee, C Patrick; Seid, Christopher A; Hammond, Molly; Hudspeth, Elissa; Keegan, Brian P; Liu, Zhuyun; Wei, Junfei; Zhan, Bin; Arjona-Sabido, Raul; Cruz-Chan, Vladimir; Dumonteil, Eric; Hotez, Peter J; Bottazzi, Maria Elena

2017-02-01

The nucleoside hydrolase gene from Leishmania donovani was cloned and expressed in Escherichia coli as a full length 36-kDa protein (LdNH36). Following lysis and extraction, the protein was purified by anion exchange and gel filtration chromatography. The purified protein had a molecular mass of approximately 36-kDa and was confirmed to be >99% pure. Using a nucleoside hydrolase assay, the protein was found to exhibit a Km of 741 ± 246 μM. Protein integrity was confirmed by lithium dodecyl sulfate polyacrylamide gel electrophoresis (LDS-PAGE), mass spectrometry (MS), and enzymatic assay. Analysis of antibody levels from immunized mice indicated that LdNH36 alone or in a stable emulsion with the Toll-like receptor-4 ligand glucopyranosyl lipid adjuvant (GLA-SE) as immunostimulant induced high levels of antigen-specific IgG antibodies. The cellular immune response indicated a T h 1 response in mice immunized with LdNH36, but only when formulated with GLA-SE. Mice immunized with the LdNH36 antigen in combination with the GLA-SE adjuvant and challenged with Leishmania mexicana showed significant reductions (>20 fold) in parasite burden, confirming the protective efficacy of this vaccine candidate. Copyright © 2016 Elsevier Inc. All rights reserved.

Mobile suitcase laboratory for rapid detection of Leishmania donovani using recombinase polymerase amplification assay.

PubMed

Mondal, Dinesh; Ghosh, Prakash; Khan, Md Anik Ashfaq; Hossain, Faria; Böhlken-Fascher, Susanne; Matlashewski, Greg; Kroeger, Axel; Olliaro, Piero; Abd El Wahed, Ahmed

2016-05-13

Leishmania donovani (LD) is a protozoan parasite transmitted to humans from sand flies, which causes Visceral Leishmaniasis (VL). Currently, the diagnosis is based on presence of the anti-LD antibodies and clinical symptoms. Molecular diagnosis would require real-time PCR, which is not easy to implement at field settings. In this study, we report on the development and testing of a recombinase polymerase amplification (RPA) assay for the detection of LD. A genomic DNA sample was applied to determine the assay analytical sensitivity. The cross-reactivity of the assay was tested by DNA of Leishmania spp. and of pathogens considered for differential diagnosis. The clinical performance of the assay was evaluated on LD positive and negative samples. All results were compared with real-time PCR. To allow the use of the assay at field settings, a mobile suitcase laboratory (56 × 45.5 × 26.5 cm) was developed and operated at the local hospital in Mymensingh, Bangladesh. The LD RPA assay detected equivalent to one LD genomic DNA. The assay was performed at constant temperature (42 °C) in 15 min. The RPA assay also detected other Leishmania species (L. major, L. aethiopica and L. infantum), but did not identify nucleic acid of other pathogens. Forty-eight samples from VL, asymptomatic and post-kala-azar dermal leishmaniasis subjects were detected positive and 48 LD-negative samples were negative by both LD RPA and real-time PCR assays, which indicates 100 % agreement. The suitcase laboratory was successfully operated at the local hospital by using a solar-powered battery. DNA extraction was performed by a novel magnetic bead based method (SpeedXtract), in which a simple fast lysis protocol was applied. Moreover, All reagents were cold-chain independent. The mobile suitcase laboratory using RPA is ideal for rapid sensitive and specific detection of LD especially at low resource settings and could contribute to VL control and elimination programmes.

Does a regular Wessex Head Injury Matrix assessment identify early signs of infections in people with Prolonged Disorders of Consciousness?

PubMed

Dhamapurkar, Samira Kashinath; Wilson, Barbara A; Rose, Anita; Florschutz, Gerhard; Watson, Peter; Shiel, Agnes

2018-06-12

Patients with brain injury are at high risk for infections. Although infection and cognitive deterioration are established for people with dementia, this has not been shown for patients with a prolonged disorder of consciousness (PDOC). This study determines whether regular Wessex Head Injury Matrix (WHIM) assessments can identify early signs of infections in patients with PDOC. Retrospective and prospective approaches were used to assess the WHIM scores of patients with a PDOC (N = 21 in the retrospective study and 22 in the prospective study). The WHIM total scores decreased due to infections in 17 of the 21 cases of infection (p < 0.001) in the retrospective study and 15 (p = 0.001) of the 22 prospective cases of infection. Patients in a minimally conscious state (MCS) showed a bigger proportion of change between their baseline score and the scores taken in the pre-infection stage in both the retrospective and prospective studies when compared to patients in a vegetative state (VS). The findings suggest the importance of serial WHIM assessments throughout the period of recovery, not only to measure cognitive changes but also to highlight underlying physical changes such as infections that will impact the response to rehabilitation and recovery.

Early Assessment of Pancreatic Infections and Overall Prognosis in Severe Acute Pancreatitis by Procalcitonin (PCT)

PubMed Central

Rau, Bettina M.; Kemppainen, Esko A.; Gumbs, Andrew A.; Büchler, Markus W.; Wegscheider, Karl; Bassi, Claudio; Puolakkainen, Pauli A.; Beger, Hans G.

2007-01-01

Background: Pancreatic infections and sepsis are major complications in severe acute pancreatitis (AP) with significant impact on management and outcome. We investigated the value of Procalcitonin (PCT) for identifying patients at risk to develop pancreatic infections in severe AP. Methods: A total of 104 patients with predicted severe AP were enrolled in five European academic surgical centers within 96 hours of symptom onset. PCT was measured prospectively by a semi-automated immunoassay in each center, C-reactive protein (CRP) was routinely assessed. Both parameters were monitored over a maximum of 21 consecutive days and in weekly intervals thereafter. Results: In contrast to CRP, PCT concentrations were significantly elevated in patients with pancreatic infections and associated multiorgan dysfunction syndrome (MODS) who all required surgery (n = 10) and in nonsurvivors (n = 8) early after onset of symptoms. PCT levels revealed only a moderate increase in patients with pancreatic infections in the absence of MODS (n = 7), all of whom were managed nonoperatively without mortality. A PCT value of ≥3.5 ng/mL on 2 consecutive days was superior to CRP ≥430 mg/L for the assessment of infected necrosis with MODS or nonsurvival as determined by ROC analysis with a sensitivity and specificity of 93% and 88% for PCT and 40% and 100% for CRP, respectively (P < 0.01). The single or combined prediction of the two major complications was already possible on the third and fourth day after onset of symptoms with a sensitivity and specificity of 79% and 93% for PCT ≥3.8 ng/mL compared with 36% and 97% for CRP ≥430 mg/L, respectively (P = 0.002). Conclusion: Monitoring of PCT allows early and reliable assessment of clinically relevant pancreatic infections and overall prognosis in AP. This single test parameter significantly contributes to an improved stratification of patients at risk to develop major complications. PMID:17457167

Strategic evaluation of vaccine candidate antigens for the prevention of Visceral Leishmaniasis.

PubMed

Duthie, Malcolm S; Favila, Michelle; Hofmeyer, Kimberley A; Tutterrow, Yeung L; Reed, Steven J; Laurance, John D; Picone, Alessandro; Guderian, Jeffrey; Bailor, H Remy; Vallur, Aarthy C; Liang, Hong; Mohamath, Raodoh; Vergara, Julie; Howard, Randall F; Coler, Rhea N; Reed, Steven G

2016-05-27

Infection with Leishmania parasites results in a range of clinical manifestations and outcomes, the most severe of which is visceral leishmaniasis (VL). Vaccination will likely provide the most effective long-term control strategy, as the large number of vectors and potential infectious reservoirs renders sustained interruption of Leishmania parasite transmission extremely difficult. Selection of the best vaccine is complicated because, although several vaccine antigen candidates have been proposed, they have emerged following production in different platforms. To consolidate the information that has been generated into a single vaccine platform, we expressed seven candidates as recombinant proteins in E. coli. After verifying that each recombinant protein could be recognized by VL patients, we evaluated their protective efficacy against experimental L. donovani infection of mice. Administration in formulation with the Th1-potentiating adjuvant GLA-SE indicated that each antigen could elicit antigen-specific Th1 responses that were protective. Considering the ability to reduce parasite burden along with additional factors such as sequence identity across Leishmania species, we then generated a chimeric fusion protein comprising a combination of the 8E, p21 and SMT proteins. This E. coli -expressed fusion protein was also demonstrated to protect against L. donovani infection. These data indicate a novel recombinant vaccine antigen with the potential for use in VL control programs. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Understanding the current state of infection preventionists through competency, role, and activity self-assessment.

PubMed

Kalp, Ericka L; Marx, James F; Davis, James

2017-06-01

The Association for Professionals in Infection Control and Epidemiology (APIC) MegaSurvey, administered in 2015, was completed by approximately 4,079 APIC members. The survey sought to gain a better understanding the current state of 4 components of infection prevention practice: demographic characteristics, compensation, organizational structure, and practice and competency. The data for this analysis come from the APIC MegaSurvey Practice and Competency domain. Descriptive statistics and χ 2 analyses were conducted to examine differences in infection preventionist (IP) competency, roles, and activity self-assessments. The majority of IPs self-assessed their competency as Proficient compared with Novice or Expert for each of the 8 IP core competency activities. Forty percent of IPs self-rated their competency as Expert in the Preventing/Controlling the Transmission of Infectious Agents/HAIs component. IPs reported Novice competency in Employee/Occupational Health (29%); Cleaning, Sterilization, Disinfection, and Asepsis (23%); and Education and Research categories (22%). Differences in self-rated competency among IPs by discipline type (public health, nurse, and laboratory) were identified. Differences in self-rated competency were identified for each of the 8 IP core competency activities. IPs report using various resource types to gain competency. Future research is needed to identify opportunities to increase competency levels in the weakest-rated competency activities. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Euthanasia assessment in ebola virus infected nonhuman primates.

PubMed

Warren, Travis K; Trefry, John C; Marko, Shannon T; Chance, Taylor B; Wells, Jay B; Pratt, William D; Johnson, Joshua C; Mucker, Eric M; Norris, Sarah L; Chappell, Mark; Dye, John M; Honko, Anna N

2014-11-24

Multiple products are being developed for use against filoviral infections. Efficacy for these products will likely be demonstrated in nonhuman primate models of filoviral disease to satisfy licensure requirements under the Animal Rule, or to supplement human data. Typically, the endpoint for efficacy assessment will be survival following challenge; however, there exists no standardized approach for assessing the health or euthanasia criteria for filovirus-exposed nonhuman primates. Consideration of objective criteria is important to (a) ensure test subjects are euthanized without unnecessary distress; (b) enhance the likelihood that animals exhibiting mild or moderate signs of disease are not prematurely euthanized; (c) minimize the occurrence of spontaneous deaths and loss of end-stage samples; (d) enhance the reproducibility of experiments between different researchers; and (e) provide a defensible rationale for euthanasia decisions that withstands regulatory scrutiny. Historic records were compiled for 58 surviving and non-surviving monkeys exposed to Ebola virus at the US Army Medical Research Institute of Infectious Diseases. Clinical pathology parameters were statistically analyzed and those exhibiting predicative value for survival are reported. These findings may be useful for standardization of objective euthanasia assessments in rhesus monkeys exposed to Ebola virus and may serve as a useful approach for other standardization efforts.

Euthanasia Assessment in Ebola Virus Infected Nonhuman Primates

PubMed Central

Warren, Travis K.; Trefry, John C.; Marko, Shannon T.; Chance, Taylor B.; Wells, Jay B.; Pratt, William D.; Johnson, Joshua C.; Mucker, Eric M.; Norris, Sarah L.; Chappell, Mark; Dye, John M.; Honko, Anna N.

2014-01-01

Multiple products are being developed for use against filoviral infections. Efficacy for these products will likely be demonstrated in nonhuman primate models of filoviral disease to satisfy licensure requirements under the Animal Rule, or to supplement human data. Typically, the endpoint for efficacy assessment will be survival following challenge; however, there exists no standardized approach for assessing the health or euthanasia criteria for filovirus-exposed nonhuman primates. Consideration of objective criteria is important to (a) ensure test subjects are euthanized without unnecessary distress; (b) enhance the likelihood that animals exhibiting mild or moderate signs of disease are not prematurely euthanized; (c) minimize the occurrence of spontaneous deaths and loss of end-stage samples; (d) enhance the reproducibility of experiments between different researchers; and (e) provide a defensible rationale for euthanasia decisions that withstands regulatory scrutiny. Historic records were compiled for 58 surviving and non-surviving monkeys exposed to Ebola virus at the US Army Medical Research Institute of Infectious Diseases. Clinical pathology parameters were statistically analyzed and those exhibiting predicative value for survival are reported. These findings may be useful for standardization of objective euthanasia assessments in rhesus monkeys exposed to Ebola virus and may serve as a useful approach for other standardization efforts. PMID:25421892

Enterovirus infections in Singaporean children: an assessment of neurological manifestations and clinical outcomes.

PubMed

Thong, Wen Yi; Han, Audrey; Wang, S J Furene; Lin, Jeremy; Isa, Mas Suhaila; Koay, Evelyn Siew Chuan; Tay, Stacey Kiat-Hong

2017-04-01

Enterovirus infections in childhood can be associated with significant neurological morbidity. This study aimed to describe the prevalence and range of neurological manifestations, determine the clinical characteristics and assess differences in clinical outcomes for Singaporean children diagnosed with enterovirus infections. In this single-centre, case-control study, clinical data was collected retrospectively from patients admitted to National University Hospital, Singapore, from August 2007 to October 2011 and diagnosed with enterovirus infection, based on the enterovirus polymerase chain reaction test, or cultures from throat and rectal swabs or cerebrospinal fluid samples. The occurrence of neurological manifestations was reviewed and clinical outcomes were assessed. A total of 48 patients (age range: six days-17.8 years) were included in the study. Neurological manifestations were seen in 75.0% of patients, 63.9% of whom presented with aseptic meningitis. Other neurological manifestations included encephalitis, acute cerebellitis, transverse myelitis and autonomic dysfunction. The incidence of neurological manifestations was significantly higher in patients aged > 1 year as compared to younger patients (p = 0.043). In patients without neurological manifestations, a significantly higher proportion presented with hand, foot and mouth disease and poor feeding. Long-term neurological sequelae were seen in 16.7% of patients with neurological manifestations. A wide spectrum of neurological manifestations resulting in a relatively low incidence of long-term neurological sequelae was observed in our study of Singaporean children with enterovirus infections. As some of these neurological morbidities were severe, careful evaluation of children with neurological involvement is therefore necessary. Copyright: © Singapore Medical Association

Assessing dengue infection risk in the southern region of Taiwan: implications for control.

PubMed

Liao, C-M; Huang, T-L; Cheng, Y-H; Chen, W-Y; Hsieh, N-H; Chen, S-C; Chio, C-P

2015-04-01

Dengue, one of the most important mosquito-borne diseases, is a major international public health concern. This study aimed to assess potential dengue infection risk from Aedes aegypti in Kaohsiung and the implications for vector control. Here we investigated the impact of dengue transmission on human infection risk using a well-established dengue-mosquito-human transmission dynamics model. A basic reproduction number (R 0)-based probabilistic risk model was also developed to estimate dengue infection risk. Our findings confirm that the effect of biting rate plays a crucial role in shaping R 0 estimates. We demonstrated that there was 50% risk probability for increased dengue incidence rates exceeding 0.5-0.8 wk-1 for temperatures ranging from 26°C to 32°C. We further demonstrated that the weekly increased dengue incidence rate can be decreased to zero if vector control efficiencies reach 30-80% at temperatures of 19-32°C. We conclude that our analysis on dengue infection risk and control implications in Kaohsiung provide crucial information for policy-making on disease control.

Preclinical Assessment of a 68Ga-DOTA-Functionalized Depsipeptide as a Radiodiagnostic Infection Imaging Agent.

PubMed

Ebenhan, Thomas; Mokaleng, Botshelo Brenda; Venter, Jacobus Daniel; Kruger, Hendrik Gert; Zeevaart, Jan Rijn; Sathekge, Mike

2017-08-24

The study assessed a radiolabeled depsipeptide conjugate ( 68 Ga-DOTA-TBIA101) for its potential as an imaging agent targeting infection or infection-associated inflammation. 68 Ga-labeled DOTA-TBIA101 imaging was performed in (NZR1) healthy rabbits; (NZR2) rabbits bearing muscular sterile inflammation and Staphylococcus aureus (SA) infection; and (NZR3) rabbits infected with Mycobacterium tuberculosis (MTB) combined with a subcutaneous scruff infection of SA in the same animal. All animals were imaged using a PET/CT scanner at 5 and 60 min post injection. Images showed elevated accumulation of 68 Ga-DOTA-TBIA101 in the sterile muscular inflammation site (T/NT ratio = 2.6 ± 0.37 (5 min) and 2.8 ± 2.3 (60 min)) and muscles infected with MTB (T/NT ratio = 2.6 ± 0.35 (5 min) and 2.8 ± 0.16 (60 min)). The findings suggest that 68 Ga-DOTA-TBIA101-PET/CT may detect MTB-associated inflammation, although more foundational studies need to be performed to rationalize the diagnostic value of this technique.

CLABSI Conversations: Lessons From Peer-to-Peer Assessments to Reduce Central Line-Associated Bloodstream Infections.

PubMed

Pham, Julius Cuong; Goeschel, Christine A; Berenholtz, Sean M; Demski, Renee; Lubomski, Lisa H; Rosen, Michael A; Sawyer, Melinda D; Thompson, David A; Trexler, Polly; Weaver, Sallie J; Weeks, Kristina R; Pronovost, Peter J

2016-01-01

A national collaborative helped many hospitals dramatically reduce central line-associated bloodstream infections (CLABSIs), but some hospitals struggled to reduce infection rates. This article describes the development of a peer-to-peer assessment process (CLABSI Conversations) and the practical, actionable practices we discovered that helped intensive care unit teams achieve a CLABSI rate of less than 1 infection per 1000 catheter-days for at least 1 year. CLABSI Conversations was designed as a learning-oriented process, in which a team of peers visited hospitals to surface barriers to infection prevention and to share best practices and insights from successful intensive care units. Common practices led to 10 recommendations: executive and board leaders communicate the goal of zero CLABSI throughout the hospital; senior and unit-level leaders hold themselves accountable for CLABSI rates; unit physicians and nurse leaders own the problem; clinical leaders and infection preventionists build infection prevention training and simulation programs; infection preventionists participate in unit-based CLABSI reduction efforts; hospital managers make compliance with best practices easy; clinical leaders standardize the hospital's catheter insertion and maintenance practices and empower nurses to stop any potentially harmful acts; unit leaders and infection preventionists investigate CLABSIs to identify root causes; and unit nurses and staff audit catheter maintenance policies and practices.

Infection control in delivery care units, Gujarat state, India: A needs assessment

PubMed Central

2011-01-01

Background Increasingly, women in India attend health facilities for childbirth, partly due to incentives paid under government programs. Increased use of health facilities can alleviate the risks of infections contracted in unhygienic home deliveries, but poor infection control practices in labour and delivery units also cause puerperal sepsis and other infections of childbirth. A needs assessment was conducted to provide information on procedures and practices related to infection control in labour and delivery units in Gujarat state, India. Methods Twenty health care facilities, including private and public primary health centres and referral hospitals, were sampled from two districts in Gujarat state, India. Three pre-tested tools for interviewing and for observation were used. Data collection was based on existing infection control guidelines for clean practices, clean equipment, clean environment and availability of diagnostics and treatment. The study was carried out from April to May 2009. Results Seventy percent of respondents said that standard infection control procedures were followed, but a written procedure was only available in 5% of facilities. Alcohol rubs were not used for hand cleaning and surgical gloves were reused in over 70% of facilities, especially for vaginal examinations in the labour room. Most types of equipment and supplies were available but a third of facilities did not have wash basins with "hands-free" taps. Only 15% of facilities reported that wiping of surfaces was done immediately after each delivery in labour rooms. Blood culture services were available in 25% of facilities and antibiotics are widely given to women after normal delivery. A few facilities had data on infections and reported rates of 3% to 5%. Conclusions This study of current infection control procedures and practices during labour and delivery in health facilities in Gujarat revealed a need for improved information systems, protocols and procedures, and for

Voacamine alters Leishmania ultrastructure and kills parasite by poisoning unusual bi-subunit topoisomerase IB.

PubMed

Chowdhury, Somenath Roy; Kumar, Ashish; Godinho, Joseane Lima Prado; De Macedo Silva, Sara Teixeira; Zuma, Aline Araujo; Saha, Sourav; Kumari, Neha; Rodrigues, Juliany Cola Fernandes; Sundar, Shyam; Dujardin, Jean-Claude; Roy, Syamal; De Souza, Wanderley; Mukhopadhyay, Sibabrata; Majumder, Hemanta K

2017-08-15

Indole alkaloids possess a large spectrum of biological activities including anti-protozoal action. Here we report for the first time that voacamine, isolated from the plant Tabernaemontana coronaria, is an antiprotozoal agent effective against a large array of trypanosomatid parasites including Indian strain of Leishmania donovani and Brazilian strains of Leishmania amazonensis and Trypanosoma cruzi. It inhibits the relaxation activity of topoisomerase IB of L. donovani (LdTop1B) and stabilizes the cleavable complex. Voacamine is probably the first LdTop1B-specific poison to act uncompetitively. It has no impact on human topoisomerase I and II up to 200μM concentrations. The study also provides a thorough insight into ultrastructural alterations induced in three kinetoplastid parasites by a specific inhibitor of LdTop1B. Voacamine is also effective against intracellular amastigotes of different drug unresponsive field isolates of Leishmania donovani obtained from endemic zones of India severely affected with visceral leishmaniasis. Most importantly, this is the first report demonstrating the efficacy of a compound to reduce the burden of drug resistant parasites, unresponsive to SAG, amphotericin B and miltefosine, in experimental BALB/c mice model of visceral leishmaniasis. The findings cumulatively provide a strong evidence that voacamine can be a promising drug candidate against trypanosomatid infections. Copyright © 2017 Elsevier Inc. All rights reserved.

Innovative Training for Occupational Health and Infection Control Workplace Assessment in Health Care

ERIC Educational Resources Information Center

O'Hara, Lyndsay; Bryce, Elizabeth Ann; Scharf, Sydney; Yassi, Annalee

2012-01-01

A user-friendly, high quality workplace assessment field guide and an accompanying worksheet are invaluable tools for recognizing hazards in the hospital environment. These tools ensure that both front line workers as well as health and safety and infection control professionals can systematically evaluate hazards and formulate recommendations.…

Screening of Toxoplasma gondii infection among childbearing age females and assessment of nurses' role in prevention and control of toxoplasmosis.

PubMed

Saleh, Ahmed Megahed Ahmed; Ali, Hisham abd El-Raouf; Ahmed, Salwa Abdalla Mohamed; Hosny, Samah Mostafa; Morsy, Tosson A

2014-08-01

Toxoplasmosis, caused by Toxoplasma gondii is an obligate intracellular zoonotic protozoan parasite, with a worldwide distribution particularly in Arab countries including Egypt. The study evaluated toxoplasmosis infection among childbearing age Egyptian females and assessed the military nursing staff knowledge, attitude and compliance to toxoplasmosis prevention and control measures. The study was conductedin a general military hospital. CROSS-section descriptive research design was used to conduct this study. The subjects consisted of 14 young females (11 were in-patients undergoing gynecological treatment in a military hospital and 3 were staff nurses. On the other hand, 44 staff nurses were available for assessment who met the inclusion criteria. 4 tools were used for data collection: first consisted of self-administered questionnaires to assess nurses' socio-demographic data and knowledge, second rating scale to assess nurses' attitude towards toxoplasmosis infection and its prevention, third performance check list to measure nurses' compliance to infection control measures, and fourth measured the anti-Toxoplasma antibodies by commercial indirect hemagglutination test (IHAT). The results showed that almost half of the nurses had satisfactory levels of knowledge, attitude, and compliance to toxoplasmosis infection control measures. 22.2% of the pregnant women and 20% of non-pregnant ones showed antibodies against T. gondii. Thus health education about toxoplasmosis should be tailored to women whether married or single to help in avoiding the risk of infection. Frequent periodic IHAT should be done for people who continuously contact with cats. Adherence to strict infection prevention measures is a must to eliminate exposure to toxoplasmosis infection. Training intervention should be implemented to achieve successful improvement in knowledge, attitude, and compliance of toxoplasmosis control measures.

Application of speckle image correlation for real-time assessment of metabolic activity in herpes virus-infected cells

NASA Astrophysics Data System (ADS)

Vladimirov, A. P.; Malygin, A. S.; Mikhailova, J. A.; Borodin, E. M.; Bakharev, A. A.; Poryvayeva, A. P.

2014-09-01

Earlier we reported developing a speckle interferometry technique and a device designed to assess the metabolic activity of a cell monolayer cultivated on a glass substrate. This paper aimed at upgrading the technique and studying its potential for real-time assessment of herpes virus development process. Speckle dynamics was recorded in the image plane of intact and virus-infected cell monolayer. HLE-3, L-41 and Vero cells were chosen as research targets. Herpes simplex virus-1-(HSV-1)- infected cell cultures were studied. For 24 h we recorded the digital value of optical signal I in one pixel and parameter η characterizing change in the distribution of the optical signal on 10 × 10-pixel areas. The coefficient of multiple determination calculated by η time dependences for three intact cell cultures equals 0.94. It was demonstrated that the activity parameters are significantly different for intact and virus-infected cells. The difference of η value for intact and HSV-1-infected cells is detectable 10 minutes from the experiment start.

In-silico screening and validation of high-affinity tetra-peptide inhibitor of Leishmania donovani O-acetyl serine sulfhydrylase (OASS).

PubMed

Kant, Vishnu; Vijayakumar, Saravanan; Sahoo, Ganesh Chandra; Chaudhery, Shailendra S; Das, Pradeep

2018-02-07

OASS is a specific enzyme that helps Leishmania parasite to survive the oxidative stress condition in human macrophages. SAT C-terminal peptides in several organisms, including Leishmania, were reported to inhibit or reduce the activity of OASS. Small peptide and small molecules mimicking the SAT C-terminal residues are designed and tested for the inhibition of OASS in different organisms. Hence, in this study, all the possible tetra-peptide combinations were designed and screened based on the docking ability with Leishmania donovani OASS (Ld-OASS). The top ranked peptides were further validated for the stability using 50 ns molecular dynamic simulation. In order to identify the better binding capability of the peptides, the top peptides complexed with Ld-OASS were also subjected to molecular dynamic simulation. The docking and simulation results favored the peptide EWSI to possess greater advantage than previously reported peptide (DWSI) in binding with Ld-OASS active site. Also, screening of non-peptide inhibitor of Asinex Biodesign library based on the shape similarity of EWSI and DWSI was performed. The top similar molecules of each peptides were docked on to Ld-OASS active site and subsequently simulated for 20 ns. The results suggested that the ligand that shares high shape similarity with EWSI possess better binding capability than the ligand that shares high shape similarity with DWSI. This study revealed that the tetra-peptide EWSI had marginal advantage over DWSI in binding with Ld-OASS, thereby providing basis for defining a pharmacophoric scaffold for the design of peptidomimetic inhibitors as well as non-peptide inhibitors of Ld-OASS.

Noninvasive Diagnosis of Visceral Leishmaniasis: Development and Evaluation of Two Urine-Based Immunoassays for Detection of Leishmania donovani Infection in India

PubMed Central

Ejazi, Sarfaraz Ahmad; Bhattacharya, Pradyot; Bakhteyar, Md. Asjad Karim; Mumtaz, Aquil Ahmad; Pandey, Krishna; Das, Vidya Nand Ravi; Das, Pradeep; Rahaman, Mehebubar; Goswami, Rama Prosad; Ali, Nahid

2016-01-01

Background Visceral Leishmaniasis (VL), a severe parasitic disease, could be fatal if diagnosis and treatment is delayed. Post kala-azar dermal leishmaniasis (PKDL), a skin related outcome, is a potential reservoir for the spread of VL. Diagnostic tests available for VL such as tissue aspiration are invasive and painful although they are capable of evaluating the treatment response. Serological tests although less invasive than tissue aspiration are incompetent to assess cure. Parasitological examination of slit-skin smear along with the clinical symptoms is routinely used for diagnosis of PKDL. Therefore, a noninvasive test with acceptable sensitivity and competency, additionally, to decide cure would be an asset in disease management and control. Methodology/principal findings We describe here, the development of antibody-capture ELISA and field adaptable dipstick test as noninvasive diagnostic tools for VL and PKDL and as a test of cure in VL treatment. Sensitivity and specificity of urine-ELISA were 97.94% (95/97) and 100% (75/75) respectively, for VL. Importantly, dipstick test demonstrated 100% sensitivity (97/97) and specificity (75/75) in VL diagnosis. Degree of agreement of the two methods with tissue aspiration was 98.83% (κ = 0.97) and 100% (κ = 1), for ELISA and dipstick test, respectively. Both the tests had 100% positivity for PKDL (14/14) cases. ELISA and dipstick test illustrated treatment efficacy in about 90% (16/18) VL cases when eventually turned negative after six months of treatment. Conclusions/significance ELISA and dipstick test found immensely effective for diagnosis of VL and PKDL through urine samples thus, may substitute the existing invasive diagnostics. Utility of these tests as indirect methods of monitoring parasite clearance can define infected versus cured. Urine-based dipstick test is simple, sensitive and above all noninvasive method that may help not only in active VL case detection but also to ascertain treatment response

Homology modelling, molecular docking, and molecular dynamics simulations reveal the inhibition of Leishmania donovani dihydrofolate reductase-thymidylate synthase enzyme by Withaferin-A.

PubMed

Vadloori, Bharadwaja; Sharath, A K; Prabhu, N Prakash; Maurya, Radheshyam

2018-04-16

Present in silico study was carried out to explore the mode of inhibition of Leishmania donovani dihydrofolate reductase-thymidylate synthase (Ld DHFR-TS) enzyme by Withaferin-A, a withanolide isolated from Withania somnifera. Withaferin-A (WA) is known for its profound multifaceted properties, but its antileishmanial activity is not well understood. The parasite's DHFR-TS enzyme is diverse from its mammalian host and could be a potential drug target in parasites. A 3D model of Ld DHFR-TS enzyme was built and verified using Ramachandran plot and SAVES tools. The protein was docked with WA-the ligand, methotrexate (MTX)-competitive inhibitor of DHFR, and dihydrofolic acid (DHFA)-substrate for DHFR-TS. Molecular docking studies reveal that WA competes for active sites of both Hu DHFR and TS enzymes whereas it binds to a site other than active site in Ld DHFR-TS. Moreover, Lys 173 residue of DHFR-TS forms a H-bond with WA and has higher binding affinity to Ld DHFR-TS than Hu DHFR and Hu TS. The MD simulations confirmed the H-bonding interactions were stable. The binding energies of WA with Ld DHFR-TS were calculated using MM-PBSA. Homology modelling, molecular docking and MD simulations of Ld DHFR-TS revealed that WA could be a potential anti-leishmanial drug.

Probing the Molecular Mechanism of Hypericin-Induced Parasite Death Provides Insight into the Role of Spermidine beyond Redox Metabolism in Leishmania donovani

PubMed Central

Singh, Shalini; Sarma, Shyamali; Katiyar, Shashank P.; Das, Mousumi; Bhardwaj, Ruchika; Sundar, Durai

2014-01-01

Hypericin, a natural compound from Hypericum perforatum (St. John's wort), has been identified as a specific inhibitor of Leishmania donovani spermidine synthase (LdSS) using integrated computational and biochemical approaches. Hypericin showed in vitro inhibition of recombinant LdSS enzyme activity. The in vivo estimation of spermidine levels in Leishmania promastigotes after hypericin treatment showed significant decreases in the spermidine pools of the parasites, indicating target specificity of the inhibitor molecule. The inhibitor, hypericin, showed significant antileishmanial activity, and the mode of death showed necrosis-like features. Further, decreased trypanothione levels and increased glutathione levels with elevated reactive oxygen species (ROS) levels were observed after hypericin treatment. Supplementation with trypanothione in the medium with hypericin treatment restored in vivo trypanothione levels and ROS levels but could not prevent necrosis-like death of the parasites. However, supplementation with spermidine in the medium with hypericin treatment restored in vivo spermidine levels and parasite death was prevented to a large extent. The data overall suggest that the parasite death due to spermidine starvation as a result of LdSS inhibition is not related to elevated levels of reactive oxygen species. This suggests the involvement of spermidine in processes other than redox metabolism in Leishmania parasites. Moreover, the work provides a novel scaffold, i.e., hypericin, as a potent antileishmanial molecule. PMID:25313212

Antiprotozoal activity of medicinal plants used by Iquitos-Nauta road communities in Loreto (Peru).

PubMed

Vásquez-Ocmín, Pedro; Cojean, Sandrine; Rengifo, Elsa; Suyyagh-Albouz, Soulaf; Amasifuen Guerra, Carlos A; Pomel, Sébastien; Cabanillas, Billy; Mejía, Kember; Loiseau, Philippe M; Figadère, Bruno; Maciuk, Alexandre

2018-01-10

In the Peruvian Amazon, the use of medicinal plants is a common practice. However, there is few documented information about the practical aspects of their use and few scientific validation. The starting point for this work was a set of interviews of people living in rural communities from the Peruvian Amazon about their uses of plants. Protozoan diseases are a public health issue in the Amazonian communities, who partly cope with it by using traditional remedies. Validation of these traditional practices contributes to public health care efficiency and may help identify new antiprotozoal compounds. to inventory and validate the use of medicinal plants by rural people of Loreto region. Rural mestizos were interviewed about traditional medication of parasite infections with medicinal plants. Ethnopharmacological surveys were undertaken in two villages along Iquitos-Nauta road (Loreto region, Peru), namely 13 de Febrero and El Dorado communities. Forty-six plants were collected according to their traditional use for the treatment of parasitic diseases, 50 ethanolic extracts (different parts for some of the plants) were tested in vitro on Plasmodium falciparum (3D7 sensitive strain and W2 chloroquine resistant strain), Leishmania donovani LV9 strain and Trypanosoma brucei gambiense. Cytotoxic assessment (HUVEC cells) of the active extracts was performed. Two of the most active plants were submitted to preliminary bioguided fractionation to ascertain and explore their activities. From the initial plants list, 10 were found to be active on P. falciparum, 15 on L. donovani and 2 on the three parasites. The ethanolic extract from Costus curvibracteatus (Costaceae) leaves and Grias neuberthii (Lecythidaceae) bark showed strong in vitro activity on P. falciparum (sensitive and resistant strain) and L. donovani and moderate activity on T. brucei gambiense. The Amazonian forest communities in Peru represents a source of knowledge on the use of medicinal plants. In this work

Application of a salivary immunoassay to assess waterborne Cryptosporidium infections in a prospective community study

EPA Science Inventory

Background: Salivary antibody is a promising non-invasive biomarker of specific infections. This exploratory study used an in-house salivary immunoassay to assess waterborne transmission of Cryptosporidium. Methods: Families with children were followed during summer-early wint...

Comparison of LAMP and PCR for molecular mass screening of sand flies for Leishmania martiniquensis infection.

PubMed

Tiwananthagorn, Saruda; Kato, Hirotomo; Yeewa, Ranchana; Muengpan, Amontip; Polseela, Raxsina; Leelayoova, Saovanee

2017-02-01

Leishmaniasis caused by Leishmania martiniquensis infection has been reported in human and domestic animals of Martinique Island, Germany, Switzerland, USA, Myanmar and Thailand. The peculiar clinical features of disseminated cutaneous and visceral forms co-existence render the urgent need of specific diagnostic tool to identify the natural sand fly vectors for effective prevention and control strategies. Loop-mediated isothermal amplification (LAMP) of 18S rRNA gene as well as polymerase chain reaction (PCR) of minicircle kinetoplast DNA gene (PCR-mkDNA) have never been applied to detect L. martiniquensis and L. siamensis in sand fly vectors. The present study was aimed to validate malachite green-LAMP (MG-LAMP) and PCR-mkDNA techniques to detect L. martiniquensis in sand fly vectors, compared with the conventional PCR of internal transcribed spacer 1 (PCR-ITS1). We compared the validity of LAMP of 18S rRNA gene and PCR-mkDNA, to PCR-ITS1 in simulation model of L. martiniquensis infection in Sergentomyia gemmea sand flies. Attributable to the sensitivity and specificity, PCR-mkDNA was consecutively applied to detect L. martiniquensis in 380 female sand fly individuals captured in the newly identified affected region of Lamphun Province, Thailand. Results showed that PCR-mkDNA could detect at least one promastigote per sand fly, which was 10-time superior to LAMP and PCR-ITS1. In addition, PCR-mkDNA was more specific, able to differentiate L. martiniquensis from other viscerotropic Leishmania species, such as L. siamensis, L. (L.) donovani, and L. (L.) infantum. Consecutively, mass screening of L. martiniquensis in 380 female sand fly individuals by PCR-mkDNA was implemented in a new affected area of Thailand where a patient with leishmaniasis/HIV co-infection resides; however Leishmania DNA was undetected. In conclusion, PCR-mkDNA is a promising tool for molecular mass screening of L. martiniquensis infection in outbreak areas where several species of Leishmania

LIGHT: A Novel Immunotherapy for Primary and Metastatic Prostate Cancer

DTIC Science & Technology

2012-09-01

remains a mystery [16]. Here, we hypothesize an interesting connection between LIGHT and immune escape involving the interactions between LIGHT, HVEM...HVEM [12]. LIGHT is capable of disrupting BTLA-HVEM interaction through competitive binding [18]. Given two possible interactions with HVEM, naïve T... Leishmania donovani</italic> Infection. PLoS Pathog, 2011. 7(10): p. e1002279. 11. Zhu, M. and Y.-X. Fu, The role of core TNF/LIGHT family members

Assessment of morbidity due to Schistosoma japonicum infection in China

PubMed Central

2014-01-01

This paper presents a historical assessment of morbidity due to the Schistosoma japonicum infection in China. Due to the socio-economic situation, which did not allow for a control program to be implemented until the early 1950s, morbidity was serious and mortality was high before this. Based on a few investigations and published papers, it can be said that the disease caused millions of deaths, and destroyed numerous families and villages. Since the 1950s, there has been a national control program, intensive control and prevention work has been carried out, and consequently the disease is being controlled. At present, both the prevalence and the morbidity of the disease have been decreasing substantially. The morbidity of the three phases of the disease is outlined in this paper. Comparatively higher morbidity is seen in the acute and advanced phases of the disease. The four major forms of advanced schistosomiasis i.e., ascites, megalosplenia, dwarfism, and colonic tumoroid proliferation, are outlined with their characteristic clinical presentations; their proportions are different during various periods of the national control program. Ectopic schistosomiasis and the relationship between the S. japonicum infection and colorectal cancer are also discussed. Post-transmission schistosomiasis is briefly discussed (which can happen even if the disease reaches the criteria of elimination, and the infection and transmission have stopped, but yet it still develops). The problem of mammalian reservoir hosts of S. japonicum makes the epidemiology and control of schistosomiasis in China even more complicated and arduous, and the control progress in animal reservoirs is briefly presented. PMID:24529186

Assessment of the value of repeated point-prevalence surveys for analyzing the trend in nosocomial infections.

PubMed

Sartor, Catherine; Delchambre, Anne; Pascal, Laurence; Drancourt, Michel; De Micco, Philippe; Sambuc, Roland

2005-04-01

To assess the value of repeated point-prevalence surveys in measuring the trend in nosocomial infections after adjustment for case mix. A 3,500-bed teaching facility composed of 4 acute care hospitals. From May 1992 to June 1996, eight point-prevalence surveys of nosocomial infections were performed in the hospitals using a sampling process. The trend of adjusted nosocomial infection rates was studied for the four surveys that collected data on indwelling catheters. Adjusted rates were calculated using a logistic regression model and a direct standardization method. From 1992 to 1996, a total of 20,238 patients were included in the 8 point-prevalence surveys. The nosocomial infection rate decreased from 8.6% in 1992 to 5% in 1996 (P < .001). The analysis of adjusted nosocomial infection rates included 9,600 patients. Four independent risk factors were identified: length of stay greater than 12 days, hospitalization in an intensive care unit, presence of an indwelling urinary catheter, and history of a surgical procedure. After adjustment for case mix, the nosocomial infection rate still showed a downward trend (from 7.2% in 1993 to 5.1% in 1996; P = .02). Adjusted prevalence rates of nosocomial infections showed a significant downward trend during the period of this study.

Using vital signs to assess children with acute infections: a survey of current practice.

PubMed

Thompson, Matthew; Mayon-White, Richard; Harnden, Anthony; Perera, Rafael; McLeod, Diane; Mant, David

2008-04-01

GPs are advised to measure vital signs in children presenting with acute infections. Current evidence supports the value of GPs' overall assessment in determining how unwell a child is, but the additional benefit of measuring vital signs is not known. To describe the vital signs and clinical features that GPs use to assess children (aged <5 years) with acute infections. Questionnaire survey. All 210 GP principals working within a 10 mile radius of Oxford, UK. Data were collected on reported frequency, methods, and utility of measuring vital signs. Description of clinical features was used to assess the overall severity of illness. One hundred and sixty-two (77%) GPs responded. Half (54%, 95% confidence interval [CI] = 47 to 62) measured temperature at least weekly, compared to pulse (21%, 95% CI = 15 to 27), and respiratory rates (17%, 95% CI = 11 to 23). Almost half of GPs (77, 48%) never measured capillary refill time. Temperature was measured most frequently using electronic aural thermometers (131/152; 86%); auscultation or counting were used for pulse and respiratory rates. A minority used pulse oximeters to assess respiratory status (30/151, 20%). GPs' thresholds for tachypnoea were similar to published values, but there was no consensus on the threshold of tachycardia. Observations of behaviour and activity were considered more useful than vital signs in assessing severity of illness. Vital signs are uncommonly measured in children in general practice and are considered less useful than observation in assessing the severity of illness. If measurement of vital signs is to become part of standard practice, the issues of inaccurate measurement and diagnostic value need to be addressed urgently.

Assessment of urinary infection management during prenatal care in pregnant women attending public health care units in the city of Rio de Janeiro, Brazil.

PubMed

Vettore, Marcelo Vianna; Dias, Marcos; Vettore, Mario Vianna; Leal, Maria do Carmo

2013-06-01

The aim of this study was to assess the sociodemographic risk factors for urinary tract infection and the inadequacy of antenatal care, according to the Kotelchuck index, in pregnant women in the city of Rio de Janeiro. A cross-sectional study was conducted with 1,091 pregnant women, 501 with urinary tract infection, in the public health antenatal care units in Rio de Janeiro, Brazil, in 2007-2008. Demographic and socioeconomic data, obstetric history and adequacy of antenatal care were collected by interviews and antenatal care card. Inadequacy management of urinary tract infection was evaluated by professional performance, health services and women dimensions. Chi-square and multivariate logistic regression were used to compare groups and to identify associated factors with management of urinary tract infection. Pregnant teenagers, anemic and diabetic pregnant women and quality of prenatal partially adequate or inadequate were those with higher odds of urinary tract infection. In the overall assessment, 72% had inadequate management of urinary tract infection. Inadequate management of urinary tract infection was associated with brown skin color compared to white skin color. In the assessment of health professional performance, inadequacy management of urinary tract infection was more common in pregnant women with low weight and overweight and obesity. According to pregnant women evaluation, primiparous women have lower odds of inadequacy management of urinary tract infection compared to those with one or more children.

Integrated Assessment of Behavioral and Environmental Risk Factors for Lyme Disease Infection on Block Island, Rhode Island

PubMed Central

Krause, Peter J.; Niccolai, Linda; Steeves, Tanner; O’Keefe, Corrine Folsom; Diuk-Wasser, Maria A.

2014-01-01

Peridomestic exposure to Borrelia burgdorferi-infected Ixodes scapularis nymphs is considered the dominant means of infection with black-legged tick-borne pathogens in the eastern United States. Population level studies have detected a positive association between the density of infected nymphs and Lyme disease incidence. At a finer spatial scale within endemic communities, studies have focused on individual level risk behaviors, without accounting for differences in peridomestic nymphal density. This study simultaneously assessed the influence of peridomestic tick exposure risk and human behavior risk factors for Lyme disease infection on Block Island, Rhode Island. Tick exposure risk on Block Island properties was estimated using remotely sensed landscape metrics that strongly correlated with tick density at the individual property level. Behavioral risk factors and Lyme disease serology were assessed using a longitudinal serosurvey study. Significant factors associated with Lyme disease positive serology included one or more self-reported previous Lyme disease episodes, wearing protective clothing during outdoor activities, the average number of hours spent daily in tick habitat, the subject’s age and the density of shrub edges on the subject’s property. The best fit multivariate model included previous Lyme diagnoses and age. The strength of this association with previous Lyme disease suggests that the same sector of the population tends to be repeatedly infected. The second best multivariate model included a combination of environmental and behavioral factors, namely hours spent in vegetation, subject’s age, shrub edge density (increase risk) and wearing protective clothing (decrease risk). Our findings highlight the importance of concurrent evaluation of both environmental and behavioral factors to design interventions to reduce the risk of tick-borne infections. PMID:24416278

Integrated assessment of behavioral and environmental risk factors for Lyme disease infection on Block Island, Rhode Island.

PubMed

Finch, Casey; Al-Damluji, Mohammed Salim; Krause, Peter J; Niccolai, Linda; Steeves, Tanner; O'Keefe, Corrine Folsom; Diuk-Wasser, Maria A

2014-01-01

Peridomestic exposure to Borrelia burgdorferi-infected Ixodes scapularis nymphs is considered the dominant means of infection with black-legged tick-borne pathogens in the eastern United States. Population level studies have detected a positive association between the density of infected nymphs and Lyme disease incidence. At a finer spatial scale within endemic communities, studies have focused on individual level risk behaviors, without accounting for differences in peridomestic nymphal density. This study simultaneously assessed the influence of peridomestic tick exposure risk and human behavior risk factors for Lyme disease infection on Block Island, Rhode Island. Tick exposure risk on Block Island properties was estimated using remotely sensed landscape metrics that strongly correlated with tick density at the individual property level. Behavioral risk factors and Lyme disease serology were assessed using a longitudinal serosurvey study. Significant factors associated with Lyme disease positive serology included one or more self-reported previous Lyme disease episodes, wearing protective clothing during outdoor activities, the average number of hours spent daily in tick habitat, the subject's age and the density of shrub edges on the subject's property. The best fit multivariate model included previous Lyme diagnoses and age. The strength of this association with previous Lyme disease suggests that the same sector of the population tends to be repeatedly infected. The second best multivariate model included a combination of environmental and behavioral factors, namely hours spent in vegetation, subject's age, shrub edge density (increase risk) and wearing protective clothing (decrease risk). Our findings highlight the importance of concurrent evaluation of both environmental and behavioral factors to design interventions to reduce the risk of tick-borne infections.

Prevalence of liver fluke infection in Irish horses and assessment of a serological test for diagnosis of equine fasciolosis.

PubMed

Quigley, A; Sekiya, M; Egan, S; Wolfe, A; Negredo, C; Mulcahy, G

2017-03-01

There is little information on the prevalence of Fasciola hepatica infection in the horse population in Ireland or the potential impact of fluke infection on animal health. To investigate F. hepatica infection in the Irish horse population and to assess the diagnostic potential of an indirect enzyme-linked immunosorbent assay (ELISA) based on the F. hepatica recombinant cathepsin L1 (CL1) antigen. Cross-sectional abattoir survey of horses for liver fluke status. Animals (n = 200) were examined at an abattoir between May 2013 and April 2014. Horses were graded ante mortem for body condition score. Blood and faeces were collected and livers were examined post mortem by gross morphology. A cohort (n = 35) of livers were also examined histologically. Haematology and blood biochemistry, including serum liver enzyme activities, were measured and faeces were sedimented for egg counts. Serum was assayed by indirect ELISA using a recombinant CL1. The prevalence of liver fluke infection was 9.5%. There was no correlation between liver fluke status and time of year, breed classification, age group, sex, body condition score, ante mortem assessment, strongyle infection status, serum liver enzyme activities or CL1 concentration. A comparison of the CL1 ELISA in horse sera compared with a reference standard diagnosis showed high specificity of 95.6% (95% confidence interval [CI] 91.5-98.0%), but low sensitivity of 42.1% (95% CI 20.2-66.5%). This study is limited by its nature as an abattoir study, the relatively small number of animals examined (n = 200), and the absence of a known negative group of horses. Blood biomarkers are not good indicators of liver fluke infection and the CL1 ELISA is not a sensitive tool for diagnosis of fluke infection in the horse. The prevalence of F. hepatica in horses indicates that further research is required to assess the potential impact of liver fluke on equine liver health. © 2016 EVJ Ltd.

Using vital signs to assess children with acute infections: a survey of current practice

PubMed Central

Thompson, Matthew; Mayon-White, Richard; Harnden, Anthony; Perera, Rafael; McLeod, Diane; Mant, David

2008-01-01

Background GPs are advised to measure vital signs in children presenting with acute infections. Current evidence supports the value of GPs' overall assessment in determining how unwell a child is, but the additional benefit of measuring vital signs is not known. Aim To describe the vital signs and clinical features that GPs use to assess children (aged <5 years) with acute infections. Design of study Questionnaire survey. Setting All 210 GP principals working within a 10 mile radius of Oxford, UK. Method Data were collected on reported frequency, methods, and utility of measuring vital signs. Description of clinical features was used to assess the overall severity of illness. Results One hundred and sixty-two (77%) GPs responded. Half (54%, 95% confidence interval [CI] = 47 to 62) measured temperature at least weekly, compared to pulse (21%, 95% CI = 15 to 27), and respiratory rates (17%, 95% CI = 11 to 23). Almost half of GPs (77, 48%) never measured capillary refill time. Temperature was measured most frequently using electronic aural thermometers (131/152; 86%); auscultation or counting were used for pulse and respiratory rates. A minority used pulse oximeters to assess respiratory status (30/151, 20%). GPs' thresholds for tachypnoea were similar to published values, but there was no consensus on the threshold of tachycardia. Observations of behaviour and activity were considered more useful than vital signs in assessing severity of illness. Conclusion Vital signs are uncommonly measured in children in general practice and are considered less useful than observation in assessing the severity of illness. If measurement of vital signs is to become part of standard practice, the issues of inaccurate measurement and diagnostic value need to be addressed urgently. PMID:18494174

A mathematical model for HIV and hepatitis C co-infection and its assessment from a statistical perspective.

PubMed

Castro Sanchez, Amparo Yovanna; Aerts, Marc; Shkedy, Ziv; Vickerman, Peter; Faggiano, Fabrizio; Salamina, Guiseppe; Hens, Niel

2013-03-01

The hepatitis C virus (HCV) and the human immunodeficiency virus (HIV) are a clear threat for public health, with high prevalences especially in high risk groups such as injecting drug users. People with HIV infection who are also infected by HCV suffer from a more rapid progression to HCV-related liver disease and have an increased risk for cirrhosis and liver cancer. Quantifying the impact of HIV and HCV co-infection is therefore of great importance. We propose a new joint mathematical model accounting for co-infection with the two viruses in the context of injecting drug users (IDUs). Statistical concepts and methods are used to assess the model from a statistical perspective, in order to get further insights in: (i) the comparison and selection of optional model components, (ii) the unknown values of the numerous model parameters, (iii) the parameters to which the model is most 'sensitive' and (iv) the combinations or patterns of values in the high-dimensional parameter space which are most supported by the data. Data from a longitudinal study of heroin users in Italy are used to illustrate the application of the proposed joint model and its statistical assessment. The parameters associated with contact rates (sharing syringes) and the transmission rates per syringe-sharing event are shown to play a major role. Copyright © 2013 Elsevier B.V. All rights reserved.

Test-retest reliability of an infectious disease questionnaire and evaluation of self-assessed vulnerability to infections : findings of Pretest 2 of the German National Cohort.

PubMed

Castell, S; Akmatov, M K; Obi, N; Flesh-Janys, D; Nieters, A; Kemmling, Y; Pessler, F; Krause, G

2014-11-01

Large scale population-based studies focusing on infectious diseases are scarce. This may be explained by methodological obstacles concerning ascertainment of data on infectious diseases requiring, e.g. collection of data on relatively short-termed symptoms and/or collection of biosamples for pathogen identification during a narrow time window. In the German National Cohort (GNC), a novel self-administered questionnaire will be used in addition to biosampling to collect data on selected infectious diseases and symptoms. The aim of this study was to evaluate in Pretest 2 of the GNC newly added items on self-assessed vulnerability to several infectious diseases and to assess test-retest reliability of the questionnaire. The study was conducted in two study centres (Hamburg and Hanover) during Pretest 2 of the GNC. A self-administered paper questionnaire was applied. In Hamburg, participants were asked to fill in the questionnaire during their regular visit at the study centre. For test-retest reliability, participants in Hanover filled in the same questionnaire at home twice. To evaluate agreement, item-related percentage agreement and kappa (κ) were calculated. In addition, we computed Bennet's S and Krippendorf's alpha (α). Items on self-assessed vulnerability to infections were evaluated by comparing them with the corresponding self-reported frequency of infections. An explanatory factor analysis was applied to construct the scores of self-reported infection frequency and self-assessed vulnerability to infections. The evaluation of the internal consistency of the five-item instrument of self-assessed vulnerability to infections resulted in a Cronbach's α of 0.78. The factor analysis yielded evidence of one factor. The factor was divided into three groups (lowest quintile classified as "less prone to infections" compared to peers; second, middle and fourth quintiles classified as "similarly prone to infections" and highest quintile classified as "more prone to

Assessment of Sepsis-3 criteria and quick SOFA in patients with cirrhosis and bacterial infections.

PubMed

Piano, Salvatore; Bartoletti, Michele; Tonon, Marta; Baldassarre, Maurizio; Chies, Giada; Romano, Antonietta; Viale, Pierluigi; Vettore, Elia; Domenicali, Marco; Stanco, Marialuisa; Pilutti, Chiara; Frigo, Anna Chiara; Brocca, Alessandra; Bernardi, Mauro; Caraceni, Paolo; Angeli, Paolo

2017-08-31

Patients with cirrhosis have a high risk of sepsis, which confers a poor prognosis. The systemic inflammatory response syndrome (SIRS) criteria have several limitations in cirrhosis. Recently, new criteria for sepsis (Sepsis-3) have been suggested in the general population (increase of Sequential Organ Failure Assessment (SOFA) ≥2 points from baseline). Outside the intensive care unit (ICU), the quick SOFA (qSOFA (at least two among alteration in mental status, systolic blood pressure ≤100 mm Hg or respiratory rate ≥22/min)) was suggested to screen for sepsis. These criteria have never been evaluated in patients with cirrhosis. The aim of the study was to assess the ability of Sepsis-3 criteria in predicting in-hospital mortality in patients with cirrhosis and bacterial/fungal infections. 259 consecutive patients with cirrhosis and bacterial/fungal infections were prospectively included. Demographic, laboratory and microbiological data were collected at diagnosis of infection. Baseline SOFA was assessed using preadmission data. Patients were followed up until death, liver transplantation or discharge. Findings were externally validated (197 patients). Sepsis-3 and qSOFA had significantly greater discrimination for in-hospital mortality (area under the receiver operating characteristic (AUROC)=0.784 and 0.732, respectively) than SIRS (AUROC=0.606) (p<0.01 for both). Similar results were observed in the validation cohort. Sepsis-3 (subdistribution HR (sHR)=5.47; p=0.006), qSOFA (sHR=1.99; p=0.020), Chronic Liver Failure Consortium Acute Decompensation score (sHR=1.05; p=0.001) and C reactive protein (sHR=1.01;p=0.034) were found to be independent predictors of in-hospital mortality. Patients with Sepsis-3 had higher incidence of acute-on-chronic liver failure, septic shock and transfer to ICU than those without Sepsis-3. Sepsis-3 criteria are more accurate than SIRS criteria in predicting the severity of infections in patients with cirrhosis. qSOFA is a

Varicella-zoster virus infections in patients treated with fingolimod: risk assessment and consensus recommendations for management.

PubMed

Arvin, Ann M; Wolinsky, Jerry S; Kappos, Ludwig; Morris, Michele I; Reder, Anthony T; Tornatore, Carlo; Gershon, Anne; Gershon, Michael; Levin, Myron J; Bezuidenhoudt, Mauritz; Putzki, Norman

2015-01-01

Varicella-zoster virus (VZV) infections increasingly are reported in patients with multiple sclerosis (MS) and constitute an area of significant concern, especially with the advent of more disease-modifying treatments in MS that affect T-cell-mediated immunity. To assess the incidence, risk factors, and clinical characteristics of VZV infections in fingolimod-treated patients and provide recommendations for prevention and management. Rates of VZV infections in fingolimod clinical trials are based on pooled data from the completed controlled phases 2 and 3 studies (3916 participants) and ongoing uncontrolled extension phases (3553 participants). Male and female patients aged 18 through 55 years (18-60 years for the phase 2 studies) and diagnosed as having relapsing-remitting MS were eligible to participate in these studies. In the postmarketing setting, reporting rates since 2010 were evaluated. In clinical trials, patients received fingolimod at a dosage of 0.5 or 1.25 mg/d, interferon beta-1a, or placebo. In the postmarketing setting, all patients received fingolimod, 0.5 mg/d (total exposure of 54,000 patient-years at the time of analysis). Calculation of the incidence rate of VZV infection per 1000 patient-years was based on the reporting of adverse events in the trials and the postmarketing setting. Overall, in clinical trials, VZV rates of infection were low but higher with fingolimod compared with placebo (11 vs 6 per 1000 patient-years). A similar rate was confirmed in the ongoing extension studies. Rates reported in the postmarketing settings were comparable (7 per 1000 patient-years) and remained stable over time. Disproportionality in reporting herpes zoster infection was higher for patients receiving fingolimod compared with those receiving other disease-modifying treatments (empirical Bayes geometric mean, 2.57 [90% CI, 2.26-2.91]); the proportion of serious herpes zoster infections was not higher than the proportion for other treatments (empirical

Assessment of selected biochemical parameters and humoral immune response of Nile crocodiles (Crocodylus niloticus) experimentally infected with Trichinella zimbabwensis.

PubMed

La Grange, Louis J; Mukaratirwa, Samson

2014-08-21

Fifteen crocodiles were randomly divided into three groups of five animals. They represented high-infection, medium-infection and low-infection groups of 642 larvae/kg, 414 larvae/kg and 134 larvae/kg bodyweight, respectively. The parameters assessed were blood glucose, creatine phosphokinase (CPK), lactate dehydrogenase (LDH), aspartate transaminase (AST) and alanine transaminase (ALT). The humoral immune response to Trichinella zimbabwensis infection was evaluated in all three groups by an indirect ELISA method. The results showed deviations from normal parameters of blood glucose, CPK, LDH, AST and ALT when compared with reported levels in uninfected reptiles. Contrary to studies involving mammals, hypoglycaemia was not observed in the infected groups in this study. Peak values of blood glucose were reached on post-infection (PI) Day 49, Day 42 and Day 35 in the high-infection, medium-infection and low-infection groups, respectively. Peak values of LDH and AST were observed on PI Day 56, Day 49 and Day 42 in the high-infection, medium-infection and low-infection groups, respectively. Peak values of CPK were observed on Day 35 PI in all three groups. Peak ALT values were reached on Day 56 in the high-infection group and on Day 28 PI in both the medium-infection and low-infection groups. No correlations between the biochemical parameters and infection intensity were observed. Peak antibody titres were reached on Day 49 PI in the medium-infection group, and on Day 42 PI in both the high-infection and low-infection groups. Infection intensity could not be correlated with the magnitude of the humoral immune response or time to sero-conversion. Results from this study were in agreement with results reported in mammals infected with other Trichinella species and showed that antibody titres could not be detected indefinitely.

Fact or Infection: Do Surgical Trainees Know Enough About Infection Control?

PubMed Central

Brady, RRW; McDermott, C; Gibb, AP; Paterson-Brown, S

2008-01-01

INTRODUCTION There exists a high level of non-compliance with basic infection control measures by medical staff. One explanation may be a lack of familiarity with contemporary infection control guidelines. As surgical trainees represent a key group of stakeholders responsible for the delivery of recommended infection control practice, we assessed knowledge of infection control guidelines amongst current UK surgical trainees. MATERIALS AND METHODS Without warning, during the annual meeting of the UK Association of Surgeons in Training (ASiT), participating surgical trainees were asked to complete a questionnaire examining their basic knowledge of infection control and methicillin-resistant Staphylococcus aureus (MRSA) based on recently published guidelines. RESULTS A total of 52 trainees (13 higher surgical trainees [HSTs]; 39 basic surgical trainees [BSTs]) returned completed questionnaires in the study. BSTs demonstrated a higher level of knowledge of infection control, outperforming the HSTs in 7 out of 11 questions. Of surgical trainees, 61.5% were misinformed regarding the prevalence of MRSA blood-stream infections and 69% were unaware of policies for transfer of MRSA-positive patients. Analysis revealed areas of concern in regards to an adequate general level of knowledge of infection control in surgical trainees, particularly in some key areas. CONCLUSIONS To ensure patient safety and reduce hospital-acquired infections, it is vital that focused, co-ordinated programmes of education, in this rapidly changing field, are prioritised and formalised into surgical training, selection and assessment. PMID:18990279

Assessment of infection control practices in teaching hospitals of Quetta.

PubMed

Anwar, Muhammad; Majeed, Abdul; Saleem, Rana Muhammad; Manzoor, Farkhanda; Sharif, Saima

2016-08-01

To identify the gaps in infection control and prevention practices in teaching hospitals. This cross-sectional study was conducted at Bolan Medical Complex and Sandeman Medical College Hospital, Quetta, from August 2012 to January 2013.The study comprised members (n=7) of infection control committee who were interviewed through a self-developed, closed-ended questionnaire and their perception regarding infection control and prevention was recorded. Data was analysed using SPSS 16. Only 3(42.9%) of the committee members believed that the administrative factors for causing hospital-acquired infections were nurse-patient ratio. On the patient care side, 1(14.3%) participants at one of the hospitals attributed infections to antibiotic use, 5(71.4%) to invasive medical device and 1(14.3%) to other factors. Poor perception held by the members of infection control committee was the basic cause of bad outcome. Capacity-building of all the stakeholders is required.

Assessment of Polymicrobial Infections in Ticks in New York State

PubMed Central

Tokarz, Rafal; Jain, Komal; Bennett, Ashlee; Briese, Thomas

2010-01-01

Abstract Ixodes scapularis ticks are clinically important hematophagous vectors. A single tick bite can lead to a polymicrobial infection. We determined the prevalence of polymicrobial infection with Borrelia burgdorferi, Anaplasma phagocytophilum, Babesia microti, Borrelia miyamotoi, and Powassan virus in 286 adult ticks from the two counties in New York State where Lyme disease is endemic, utilizing a MassTag multiplex polymerase chain reaction assay. Seventy-one percent of the ticks harbored at least one organism; 30% had a polymicrobial infection. Infections with three microbes were detected in 5% of the ticks. One tick was infected with four organisms. Our results show that coinfection is a frequent occurrence in ticks in the two counties surveyed. PMID:19725770

Assessment of haematological parameters in HIV-infected and uninfected Rwandan women: a cross-sectional study

PubMed Central

Munyazesa, Elisaphane; Emile, Ivan; Mutimura, Eugene; Hoover, Donald R; Shi, Qiuhu; McGinn, Aileen P; Musiime, Stephenson; Muhairwe, Fred; Rutagengwa, Alfred; Dusingize, Jean Claude; Anastos, Kathryn

2012-01-01

Objectives Although haematological abnormalities are common manifestations of HIV infection, few studies on haematological parameters in HIV-infected persons have been undertaken in sub-Saharan Africa. The authors assessed factors associated with haematological parameters in HIV-infected antiretroviral-naïve and HIV-uninfected Rwandan women. Study design Cross-sectional analysis of a longitudinal cohort. Setting Community-based women's associations. Participants 710 HIV-infected (HIV+) antiretroviral-naïve and 226 HIV-uninfected (HIV−) women from the Rwanda Women's Interassociation Study Assessment. Haematological parameters categorised as (abnormal vs normal) were compared by HIV status and among HIV+ women by CD4 count category using proportions. Multivariate logistic regression models using forward selection were fit. Results Prevalence of anaemia (haemoglobin (Hb) <12.0 g/dl) was higher in the HIV+ group (20.5% vs 6.3%; p<0.001), and increased with lower CD4 counts: ≥350 (7.6%), 200–349 (16%) and <200 cells/mm3 (32.2%). Marked anaemia (Hb <10.0 g/dl) was found in 4.2% of HIV+ and none of the HIV− women (p<0.001), and was highest in HIV+ women with CD4 <200 cells/mm3 (8.4%). The HIV+ were more likely than HIV− women (4.2 vs 0.5%, respectively, p=0.002) to have moderate neutropenia with white blood cells <2.0×103 cells/mm3 and 8.4% of HIV+ women with CD4 <200 cells/mm3 had moderate neutropenia. In multivariate logistic regression analysis, BMI (OR 0.87/kg/m2, 95% CI 0.82 to 0.93; p<0.001), CD4 200–350 vs HIV− (OR 3.59, 95% CI 1.89 to 6.83; p<0.001) and CD4 <200 cells/mm3 vs HIV− (OR 8.09, 95% CI 4.37 to 14.97; <0.001) had large independent associations with anaemia. There were large independent associations of CD4 <200 cells/mm3 vs HIV− (OR 7.18, 95% CI 0.78 to 65.82; p=0.081) and co-trimoxazole and/or dapsone use (OR 5.69, 95% CI 0.63 to 51.45; p=0.122) with moderate neutropenia. Conclusions Anaemia was more common than neutropenia or

Assessment of hepatitis B virus and hepatitis C virus infections and associated risk factors in HIV infected patients at Debretabor hospital, South Gondar, Northwest Ethiopia

PubMed Central

Balew, Melashu; Moges, Feleke; Yismaw, Gizachew; Unakal, Chandrashekhar

2014-01-01

Objective To assess hepatitis B and hepatitis C virus infections and associated risk factors among HIV infected patients at Debretabor hospital. Methods A cross-sectional study was conducted among HIV/AIDS patients attending Debretabor hospital from February to April, 2012. Venous blood samples were collected from study participants for HBsAg and anti HCV antibody tests. Bivariate and multivariate analyses were used to identify associated variables with HBsAg and anti HCV positivity. Variables having P<0.05 was taken as statistically significant association. Results From a total of 395 HIV infected patients included in this study, 234 (59.2%) were females and 161 (40.8%) males with mean (±SD) age of 36.31 (±9.91) years. The prevalence of HBsAg and anti HCV antibody was 6.1% and 1.3%, respectively. In multivariate analysis, multiple sexual partner (AOR=8.1, 95% CI=1.8-33.97) and history of opportunistic infections (AOR=3.17, 95% CI=1.3-7.7) were statistically associated with HBsAg positivity. History of blood transfusion (AOR=5.61, 95% CI= 1.03-36.59) was associated with presence of anti-HCV antibody. Conclusions The prevalence of HBsAg and anti HCV antibodies in HIV coinfected patients was intermediate. However, it is relevant for HIV infected patients since viral hepatitis co-infections in HIV patients can cause multiple complications. Therefore, routine HBV and HCV screening with reliable diagnostic markers need to be carried out for close monitoring and better management in HIV patients.

Therapy with radio-attenuated vaccine in experimental murine visceral leishmaniasis showed enhanced T cell and inducible nitric oxide synthase levels, suppressed tumor growth factor-beta production with higher expression of some signaling molecules.

PubMed

Datta, Sanchita; Roy, Syamal; Manna, Madhumita

2015-01-01

Visceral leishmaniasis (VL) or Kala-Azar (KA) is one of the most deadly forms of disease among all neglected tropical diseases. There are no satisfactory drugs or vaccine candidates available for this dreaded disease. Our previous studies showed promising therapeutic and prophylactic efficacy of the live, radio-attenuated parasites through intramuscular (I.M.) and intraperitoneal (I.P.) route in BALB/c mice model. The T-cell proliferation level, the mRNA expression level of inducible nitric oxide synthase (iNOS) and tumor growth factor-beta (TGF-β) genes and finally the phosphorylation levels of phosphoinositide dependent kinase 1 (PDK1), phosphoinositide 3 kinase (PI3K) and p38 mitogen activated protein kinase (p38MAPK) molecules were checked in BALB/c mice model immunized with radio-attenuated Leishmania donovani parasites through I.M. route. Higher T-cell proliferation, increased iNOS level, and suppressed TGF-β level were found in treated infected animal groups (100 and 150Gy) in relation to untreated infected animals. Likewise, phosphorylation levels of PDK1, PI3K and p38MAPK of these two groups were increased when compared to untreated infected controls. The clearance of the parasites from treated infected groups of animals may be mediated by the restoration of T-cell due to therapy with radio-attenuated L. donovani parasites. The killing of parasites was mediated by increase in nitric oxide release through PDK1, PI3K and p38MAPK signaling pathways. A lower TGF-β expression has augmented the restored Th1 ambience in the 100 and 150Gy treated animal groups proving further the efficacy of the candidate vaccine. Copyright © 2015. Published by Elsevier Editora Ltda.

Influence of Luminol Doping of Poly(o-phenylenediamine) on the Spectral, Morphological, and Fluorescent properties: A Potential Fluorescent Marker for Early detection and Diagnosis of Leishmania donovani.

PubMed

Riaz, Ufana; Jadoun, Sapana; Kumar, Prabhat; Arish, Mohd; Rub, Abdur; Ashraf, S M

2017-09-27

There has been a steady progress in the development of doped conjugated polymers to remarkably improve their photo physical properties for their application as biomarkers. With a view to enhance the spectral, morphological, and photo physical properties of poly(o-phenylenediamine) (POPD), the present work reports the synthesis of poly(o-phenylenediamine) and doping of this polymer using luminol. The formation of luminol-doped POPD was confirmed by infrared and ultraviolet-visible spectroscopies and X-ray diffraction studies. The energy band gap values and oscillator strength of luminol in acidic, basic, and neutral media were computed by density functional theory calculations using the B3LYP/6-31G (d) basis set and were compared with experimental data. The luminol doped POPDs show significant in vitro anti-leishmanial activity. Live cell imaging also proved that these molecules bind with the organelle of Leishmania also. These luminol doped POPDs were found non-toxic at the used concentrations on THP-1 derived human macrophage cells through methyl tetrazolium (MTT) assay. The results revealed that luminol doped POPDs were potentially non-toxic to human cells though exhibited immense potential to be used as a fluorescent marker to label Leishmania donovani for diagnostic and other studies.

Application of a Multiplex Quantitative PCR to Assess Prevalence and Intensity Of Intestinal Parasite Infections in a Controlled Clinical Trial

PubMed Central

Llewellyn, Stacey; Inpankaew, Tawin; Nery, Susana Vaz; Gray, Darren J.; Verweij, Jaco J.; Clements, Archie C. A.; Gomes, Santina J.; Traub, Rebecca; McCarthy, James S.

2016-01-01

Background Accurate quantitative assessment of infection with soil transmitted helminths and protozoa is key to the interpretation of epidemiologic studies of these parasites, as well as for monitoring large scale treatment efficacy and effectiveness studies. As morbidity and transmission of helminth infections are directly related to both the prevalence and intensity of infection, there is particular need for improved techniques for assessment of infection intensity for both purposes. The current study aimed to evaluate two multiplex PCR assays to determine prevalence and intensity of intestinal parasite infections, and compare them to standard microscopy. Methodology/Principal Findings Faecal samples were collected from a total of 680 people, originating from rural communities in Timor-Leste (467 samples) and Cambodia (213 samples). DNA was extracted from stool samples and subject to two multiplex real-time PCR reactions the first targeting: Necator americanus, Ancylostoma spp., Ascaris spp., and Trichuris trichiura; and the second Entamoeba histolytica, Cryptosporidium spp., Giardia. duodenalis, and Strongyloides stercoralis. Samples were also subject to sodium nitrate flotation for identification and quantification of STH eggs, and zinc sulphate centrifugal flotation for detection of protozoan parasites. Higher parasite prevalence was detected by multiplex PCR (hookworms 2.9 times higher, Ascaris 1.2, Giardia 1.6, along with superior polyparasitism detection with this effect magnified as the number of parasites present increased (one: 40.2% vs. 38.1%, two: 30.9% vs. 12.9%, three: 7.6% vs. 0.4%, four: 0.4% vs. 0%). Although, all STH positive samples were low intensity infections by microscopy as defined by WHO guidelines the DNA-load detected by multiplex PCR suggested higher intensity infections. Conclusions/Significance Multiplex PCR, in addition to superior sensitivity, enabled more accurate determination of infection intensity for Ascaris, hookworms and

Mumps serum antibody levels before and after an outbreak to assess infection and immunity in vaccinated students.

PubMed

Gouma, Sigrid; Schurink-Van't Klooster, Tessa M; de Melker, Hester E; Kerkhof, Jeroen; Smits, Gaby P; Hahné, Susan J M; van Els, Cécile A C M; Boland, Greet J; Vossen, Ann C T M; Goswami, Pulak R; Koopmans, Marion P G; van Binnendijk, Rob S

2014-12-01

Since 2009, various mumps outbreaks have occurred in the Netherlands, affecting mostly young adults vaccinated against mumps. In this retrospective study, we estimated attack rates for symptomatic and asymptomatic mumps virus infection based on mumps-specific immunoglobulin (Ig)G concentrations in paired blood samples obtained before and after the mumps outbreaks, collected in 2 university cities. We aimed to identify a serological correlate of immune protection and risk factors for mumps virus infection. Mumps-specific IgG levels were measured by Luminex technology in paired pre- and post-outbreak samples from students from Leiden (n = 135) and Utrecht (n = 619). Persons with a 4-fold increase in mumps IgG concentrations or mumps IgG concentrations >1500 RU/mL were assumed to have had a mumps virus infection. Attack rates for symptomatic and asymptomatic mumps virus infection were 2.0% and 3.8%, respectively. Pre-outbreak mumps-specific IgG concentrations were lower among cases than among noncases (P = .005) despite vaccination history, but no serological cutoff for immune protection could be established. Mumps among housemates was significantly associated with serological evidence for mumps virus infection (odds ratio, 7.25 [95% confidence interval, 3.20-16.40]; P < .001). Symptomatic and asymptomatic mumps virus infections in vaccinated persons can be identified by retrospective assessment of mumps-specific IgG antibodies in blood samples.

Developing a tool for nurses to assess risk of infection in pediatric oncology patients in China: a modified Delphi study.

PubMed

Zhou, Yufeng; Cui, Yan; Wang, Hong; Wang, Fang; Lu, Chao; Shen, Yan

2016-09-01

Infections are identified as the most common preventable cause of death in pediatric oncology patients. Assessing and stratifying risk of infections are essential to prevent infection in these patients. To date, no tool can fulfill this demand in China. This study aimed to develop a nursing work-based and Chinese-specific tool for pediatric nurses to assess risk of infection in oncology patients. This research was a modified Delphi study. Based on a literature review, a 37-item questionnaire rating on a 0-5 scale was developed. Twenty-four experts from 8 hospitals in 6 provinces of China were consulted for three rounds. Consensus for each item in the first round was defined as: the rating mean was>3 and the coefficient of variation (CV) was<0.5. Consensus for each item in the second round was defined as CV<0.3. Consensus among experts was defined as: P value of Kendall's coefficient of concordance ( W )<0.05. After three rounds of consultation, a two-part tool was developed: the Immune Status Scale (ISS) and the Checklist of Risk Factors of Infection (CRFI). There were 5 items in the ISS and 14 in the CRFI. Based on the ISS score, nurses could stratify children into the low-risk and high-risk groups. For high-risk children, nurses should screen risk factors of infection every day by the CRFI, and twice weekly for low-risk children. Further study is needed to verify this tool's efficacy. © 2016 the Journal of Biomedical Research. All rights reserved.

Assessing the impact of feline immunodeficiency virus and bovine tuberculosis co-infection in African lions

PubMed Central

Maas, M.; Keet, D. F.; Rutten, V. P. M. G.; Heesterbeek, J. A. P.; Nielen, M.

2012-01-01

Bovine tuberculosis (BTB), caused by Mycobacterium bovis, is a disease that was introduced relatively recently into the Kruger National Park (KNP) lion population. Feline immunodeficiency virus (FIVple) is thought to have been endemic in lions for a much longer time. In humans, co-infection between Mycobacterium tuberculosis and human immunodeficiency virus increases disease burden. If BTB were to reach high levels of prevalence in lions, and if similar worsening effects would exist between FIVple and BTB as for their human equivalents, this could pose a lion conservation problem. We collected data on lions in KNP from 1993 to 2008 for spatio-temporal analysis of both FIVple and BTB, and to assess whether a similar relationship between the two diseases exists in lions. We found that BTB prevalence in the south was higher than in the north (72 versus 19% over the total study period) and increased over time in the northern part of the KNP (0–41%). No significant spatio-temporal differences were seen for FIVple in the study period, in agreement with the presumed endemic state of the infection. Both infections affected haematology and blood chemistry values, FIVple in a more pronounced way than BTB. The effect of co-infection on these values, however, was always less than additive. Though a large proportion (31%) of the lions was co-infected with FIVple and M. bovis, there was no evidence for a synergistic relation as in their human counterparts. Whether this results from different immunopathogeneses remains to be determined. PMID:22915673

Assessing the impact of feline immunodeficiency virus and bovine tuberculosis co-infection in African lions.

PubMed

Maas, M; Keet, D F; Rutten, V P M G; Heesterbeek, J A P; Nielen, M

2012-10-22

Bovine tuberculosis (BTB), caused by Mycobacterium bovis, is a disease that was introduced relatively recently into the Kruger National Park (KNP) lion population. Feline immunodeficiency virus (FIV(ple)) is thought to have been endemic in lions for a much longer time. In humans, co-infection between Mycobacterium tuberculosis and human immunodeficiency virus increases disease burden. If BTB were to reach high levels of prevalence in lions, and if similar worsening effects would exist between FIV(ple) and BTB as for their human equivalents, this could pose a lion conservation problem. We collected data on lions in KNP from 1993 to 2008 for spatio-temporal analysis of both FIV(ple) and BTB, and to assess whether a similar relationship between the two diseases exists in lions. We found that BTB prevalence in the south was higher than in the north (72 versus 19% over the total study period) and increased over time in the northern part of the KNP (0-41%). No significant spatio-temporal differences were seen for FIV(ple) in the study period, in agreement with the presumed endemic state of the infection. Both infections affected haematology and blood chemistry values, FIV(ple) in a more pronounced way than BTB. The effect of co-infection on these values, however, was always less than additive. Though a large proportion (31%) of the lions was co-infected with FIV(ple) and M. bovis, there was no evidence for a synergistic relation as in their human counterparts. Whether this results from different immunopathogeneses remains to be determined.

Assessment of the HBV vaccine response in a group of HIV-infected children in Morocco.

PubMed

Haban, Houda; Benchekroun, Soumia; Sadeq, Mina; Benjouad, Abdelaziz; Amzazi, Said; Oumzil, Hicham; Elharti, Elmir

2017-09-29

Since its development in the early 1980s, Hepatitis B virus (HBV) vaccine has been proven to be highly protective. However, its immunogenicity may be ineffective among HIV-infected children. In Morocco, HBV vaccine was introduced in 1999, and since then all infants, including vertically HIV-infected infants, have been following the vaccination schedule, implemented by the Moroccan ministry of health. An assessment of the immunization of these children is important to optimize efforts aimed at tackling Hepatitis B coinfection, within the country. Forty-nine HIV-infected children (HIV group) and 112 HIV uninfected children (control group) were enrolled in this study. Samples were tested by Elisa (Monolisa Anti-HBs, Biorad) to quantify the anti-HBs antibodies. The % of lymphocyte subsets i.e. CD4+ T cells, CD8+ T cells, B cells, and NK, was determined by flow cytometry, using CellQuest Pro software (Becton-Dickinson), and for HIV group, HIV viral load was measured by real time PCR assay (Abbott). All variables were statistically compared in the two groups. The median age was 51 ± 35 months for the HIV group and 50 ± 36 months (p > 0.05) for the control group. Female represented 63% and 41% (p = 0.01), among the HIV group and the control group, respectively. Among HIV-infected children, 71.4% (35/49) were under HAART therapy at the enrollment in the study. Seroprotection titer i.e. anti-HBs ≥10mUI/ml among control group was 76% (85/112), and only 29% (14/49) among the perinatally HIV-infected children (p < 0.0001). Lower % of CD4 + T cells was observed in HIV-infected children with a poor anti-HBs response. In this studied group, we have shown that despite the vaccination of HIV-children with HBV vaccine, 71% did not show any seroprotective response. These findings support the need for monitoring HBV vaccine response among HIV-infected children in Morocco, in order to revaccinate non-immunized children.

Quantitative assessment of organizational culture within hospitals and its relevance to infection prevention and control strategies.

PubMed

Borg, M A; Waisfisz, B; Frank, U

2015-05-01

It has been suggested that organizational culture (OC) is an important driver of infection prevention and control (IPC) behaviour among healthcare workers. This study examined OC in seven European hospitals using a validated assessment tool based on Hofstede's model, and identified significant variations in OC scores. Hospitals with low prevalence of meticillin-resistant Staphylococcus aureus (MRSA) exhibited high scores for change facilitation and change readiness, whereas hospitals with high prevalence of MRSA exhibited low scores for these determinants. It is possible to use tools, available outside health care, to study OC within hospitals and gain better insight into IPC behaviour change strategies. Copyright © 2015 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Macrophage Transactivation for Chemokine Production Identified as a Negative Regulator of Granulomatous Inflammation Using Agent-Based Modeling.

PubMed

Moyo, Daniel; Beattie, Lynette; Andrews, Paul S; Moore, John W J; Timmis, Jon; Sawtell, Amy; Hoehme, Stefan; Sampson, Adam T; Kaye, Paul M

2018-01-01

Cellular activation in trans by interferons, cytokines, and chemokines is a commonly recognized mechanism to amplify immune effector function and limit pathogen spread. However, an optimal host response also requires that collateral damage associated with inflammation is limited. This may be particularly so in the case of granulomatous inflammation, where an excessive number and/or excessively florid granulomas can have significant pathological consequences. Here, we have combined transcriptomics, agent-based modeling, and in vivo experimental approaches to study constraints on hepatic granuloma formation in a murine model of experimental leishmaniasis. We demonstrate that chemokine production by non-infected Kupffer cells in the Leishmania donovani -infected liver promotes competition with infected KCs for available iNKT cells, ultimately inhibiting the extent of granulomatous inflammation. We propose trans-activation for chemokine production as a novel broadly applicable mechanism that may operate early in infection to limit excessive focal inflammation.

Generation of growth arrested Leishmania amastigotes: a tool to develop live attenuated vaccine candidates against visceral leishmaniasis.

PubMed

Selvapandiyan, Angamuthu; Dey, Ranadhir; Gannavaram, Sreenivas; Solanki, Sumit; Salotra, Poonam; Nakhasi, Hira L

2014-06-30

Visceral leishmaniasis (VL) is fatal if not treated and is prevalent widely in the tropical and sub-tropical regions of world. VL is caused by the protozoan parasite Leishmania donovani or Leishmania infantum. Although several second generation vaccines have been licensed to protect dogs against VL, there are no effective vaccines against human VL [1]. Since people cured of leishmaniasis develop lifelong protection, development of live attenuated Leishmania parasites as vaccines, which can have controlled infection, may be a close surrogate to leishmanization. This can be achieved by deletion of genes involved in the regulation of growth and/or virulence of the parasite. Such mutant parasites generally do not revert to virulence in animal models even under conditions of induced immune suppression due to complete deletion of the essential gene(s). In the Leishmania life cycle, the intracellular amastigote form is the virulent form and causes disease in the mammalian hosts. We developed centrin gene deleted L. donovani parasites that displayed attenuated growth only in the amastigote stage and were found safe and efficacious against virulent challenge in the experimental animal models. Thus, targeting genes differentially expressed in the amastigote stage would potentially attenuate only the amastigote stage and hence controlled infectivity may be effective in developing immunity. This review lays out the strategies for attenuation of the growth of the amastigote form of Leishmania for use as live vaccine against leishmaniasis, with a focus on visceral leishmaniasis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Schistosoma japonicum infection in the pig: the effect of a patent primary infection on a challenge infection.

PubMed

Willingham, A L; Bøgh, H O; Johansen, M V; Christensen, N O; Nansen, P

1997-06-24

The response of pigs to a challenge infection of Schistosoma japonicum following a primary infection was assessed using parasitological parameters and eosinophil counts. Twenty-five Danish Landrace/Yorkshire/Duroc crossbred pigs were divided into four groups. Group A (n = 10) received a primary infection, group B (n = 5) received both a primary and challenge infection, group C (n = 5) received a challenge control infection and group D (n = 5) received no infection serving as helminth-free controls. A dose of 850 cercariae was administered by intramuscular injection at the primary infection (week 0) and challenge infection (week 12). The pigs were perfused at week 21, except for half of the group A pigs which were slaughtered at week 12. Challenge infection did not result in higher worm burdens or tissue egg counts in group B than group A at week 21 and mature/immature worm ratios were similar for the two groups. In addition, no increases in faecal egg counts or eosinophil counts were observed in group B after challenge infection. The results indicate that pigs are able to mount a very rapid and effective response to reinfection with S. japonicum following a patent primary infection resulting in prevention of establishment of challenge infection schistosomes. An anti-worm effect appears to be the main feature of this regulatory host response.

Infection and childhood leukemia: review of evidence

PubMed Central

Maia, Raquel da Rocha Paiva; Wünsch, Victor

2013-01-01

OBJECTIVE To analyze studies that evaluated the role of infections as well as indirect measures of exposure to infection in the risk of childhood leukemia, particularly acute lymphoblastic leukemia. METHODS A search in Medline, Lilacs, and SciELO scientific publication databases initially using the descriptors "childhood leukemia" and "infection" and later searching for the words "childhood leukemia" and "maternal infection or disease" or "breastfeeding" or "daycare attendance" or "vaccination" resulted in 62 publications that met the following inclusion criteria: subject aged ≤ 15 years; specific analysis of cases diagnosed with acute lymphoblastic leukemia or total leukemia; exposure assessment of mothers' or infants' to infections (or proxy of infection), and risk of leukemia. RESULTS Overall, 23 studies that assessed infections in children support the hypothesis that occurrence of infection during early childhood reduces the risk of leukemia, but there are disagreements within and between studies. The evaluation of exposure to infection by indirect measures showed evidence of reduced risk of leukemia associated mainly with daycare attendance. More than 50.0% of the 16 studies that assessed maternal exposure to infection observed increased risk of leukemia associated with episodes of influenza, pneumonia, chickenpox, herpes zoster, lower genital tract infection, skin disease, sexually transmitted diseases, Epstein-Barr virus, and Helicobacter pylori. CONCLUSIONS Although no specific infectious agent has been identified, scientific evidence suggests that exposure to infections has some effect on childhood leukemia etiology. PMID:24626555

Inaccuracy of Enzyme-Linked Immunosorbent Assay Using Soluble and Recombinant Antigens to Detect Asymptomatic Infection by Leishmania infantum

PubMed Central

Moreno, Elizabeth Castro; Gonçalves, Andréa Vieira; Chaves, Anderson Vieira; Melo, Maria Norma; Lambertucci, José Roberto; Andrade, Antero Silva Ribeiro; Negrão-Corrêa, Deborah; Antunes, Carlos Mauricio de Figueiredo; Carneiro, Mariângela

2009-01-01

Background One of the most important drawbacks in visceral leishmaniasis (VL) population studies is the difficulty of diagnosing asymptomatic carriers. The aim of this study, conducted in an urban area in the Southeast of Brazil, was to evaluate the performance of serology to identify asymptomatic VL infection in participants selected from a cohort with a two-year follow-up period. Methodology Blood samples were collected in 2001 from 136 cohort participants (97 positive and 39 negatives, PCR/hybridization carried out in 1999). They were clinically evaluated and none had progressed to disease from their asymptomatic state. As controls, blood samples from 22 control individuals and 8 patients with kala-azar were collected. Two molecular biology techniques (reference tests) were performed: PCR with Leishmania-generic primer followed by hybridization using L. infantum probe, and PCR with specific primer to L. donovani complex. Plasma samples were tested by ELISA using three different antigens: L. infantum and L. amazonensis crude antigens, and rK39 recombinant protein. Accuracy of the serological tests was evaluated using sensitivity, specificity, likelihood ratio and ROC curve. Findings The presence of Leishmania was confirmed, by molecular techniques, in all kala-azar patients and in 117 (86%) of the 136 cohort participants. Kala-azar patients showed high reactivity in ELISAs, whereas asymptomatic individuals presented low reactivity against the antigens tested. When compared to molecular techniques, the L. amazonensis and L. infantum antigens showed higher sensitivity (49.6% and 41.0%, respectively) than rK39 (26.5%); however, the specificity of rK39 was higher (73.7%) than L. amazonensis (52.6%) and L. infantum antigens (36.8%). Moreover, there was low agreement among the different antigens used (kappa<0.10). Conclusions Serological tests were inaccurate for diagnosing asymptomatic infections compared to molecular methods; this could lead to misclassification bias

Mumps Serum Antibody Levels Before and After an Outbreak to Assess Infection and Immunity in Vaccinated Students

PubMed Central

Gouma, Sigrid; Schurink-van't Klooster, Tessa M.; de Melker, Hester E.; Kerkhof, Jeroen; Smits, Gaby P.; Hahné, Susan J. M.; van Els, Cécile A. C. M.; Boland, Greet J.; Vossen, Ann C. T. M.; Goswami, Pulak R.; Koopmans, Marion P. G.; van Binnendijk, Rob S.

2014-01-01

Background  Since 2009, various mumps outbreaks have occurred in the Netherlands, affecting mostly young adults vaccinated against mumps. In this retrospective study, we estimated attack rates for symptomatic and asymptomatic mumps virus infection based on mumps-specific immunoglobulin (Ig)G concentrations in paired blood samples obtained before and after the mumps outbreaks, collected in 2 university cities. We aimed to identify a serological correlate of immune protection and risk factors for mumps virus infection. Methods  Mumps-specific IgG levels were measured by Luminex technology in paired pre- and post-outbreak samples from students from Leiden (n = 135) and Utrecht (n = 619). Persons with a 4-fold increase in mumps IgG concentrations or mumps IgG concentrations >1500 RU/mL were assumed to have had a mumps virus infection. Results  Attack rates for symptomatic and asymptomatic mumps virus infection were 2.0% and 3.8%, respectively. Pre-outbreak mumps-specific IgG concentrations were lower among cases than among noncases (P = .005) despite vaccination history, but no serological cutoff for immune protection could be established. Mumps among housemates was significantly associated with serological evidence for mumps virus infection (odds ratio, 7.25 [95% confidence interval, 3.20–16.40]; P < .001). Conclusions  Symptomatic and asymptomatic mumps virus infections in vaccinated persons can be identified by retrospective assessment of mumps-specific IgG antibodies in blood samples. PMID:25734169

Immunoprotective responses of T helper type 1 stimulatory protein‐S‐adenosyl‐L‐homocysteine hydrolase against experimental visceral leishmaniasis

PubMed Central

Khare, P.; Jaiswal, A. K.; Tripathi, C. D. P.; Sundar, S.

2016-01-01

Summary It is well known that a patient in clinical remission of visceral leishmaniasis (VL) remains immune to reinfection, which provides a rationale for the feasibility of a vaccine against this deadly disease. In earlier studies, observation of significant cellular responses in treated Leishmania patients as well as in hamsters against leishmanial antigens from different fractions led to its further proteomic characterization, wherein S‐adenosyl‐L‐homocysteine hydrolase (AdoHcy) was identified as a helper type 1 (Th1) stimulatory protein. The present study includes immunological characterization of this protein, its cellular responses [lymphoproliferation, nitric oxide (NO) production and cytokine responses] in treated Leishmania‐infected hamsters and patients as well as prophylactic efficacy against Leishmania challenge in hamsters and the immune responses generated thereof. Significantly higher cellular responses were noticed against recombinant L. donovani S‐adenosyl‐L‐homocysteine hydrolase (rLdAdoHcy) compared to soluble L. donovani antigen in treated samples. Moreover, stimulation of peripheral blood mononuclear cells with rLdAdoHcy up‐regulated the levels of interferon (IFN)‐γ, interleukin (IL)−12 and down‐regulated IL‐10. Furthermore, vaccination with rLdAdoHcy generated perceptible delayed‐type hypersensitivity response and exerted considerably good prophylactic efficacy (∼70% inhibition) against L. donovani challenge. The efficacy was confirmed by the increased expression levels of inducible NO synthase and Th1‐type cytokines, IFN‐γ and IL‐12 and down‐regulation of IL‐4, IL‐10 and transforming growth factor (TGF)‐β. The results indicate the potentiality of rLdAdoHcy protein as a suitable vaccine candidate against VL. PMID:26898994

Immunoprotective responses of T helper type 1 stimulatory protein-S-adenosyl-L-homocysteine hydrolase against experimental visceral leishmaniasis.

PubMed

Khare, P; Jaiswal, A K; Tripathi, C D P; Sundar, S; Dube, A

2016-08-01

It is well known that a patient in clinical remission of visceral leishmaniasis (VL) remains immune to reinfection, which provides a rationale for the feasibility of a vaccine against this deadly disease. In earlier studies, observation of significant cellular responses in treated Leishmania patients as well as in hamsters against leishmanial antigens from different fractions led to its further proteomic characterization, wherein S-adenosyl-L-homocysteine hydrolase (AdoHcy) was identified as a helper type 1 (Th1) stimulatory protein. The present study includes immunological characterization of this protein, its cellular responses [lymphoproliferation, nitric oxide (NO) production and cytokine responses] in treated Leishmania-infected hamsters and patients as well as prophylactic efficacy against Leishmania challenge in hamsters and the immune responses generated thereof. Significantly higher cellular responses were noticed against recombinant L. donovani S-adenosyl-L-homocysteine hydrolase (rLdAdoHcy) compared to soluble L. donovani antigen in treated samples. Moreover, stimulation of peripheral blood mononuclear cells with rLdAdoHcy up-regulated the levels of interferon (IFN)-γ, interleukin (IL)-12 and down-regulated IL-10. Furthermore, vaccination with rLdAdoHcy generated perceptible delayed-type hypersensitivity response and exerted considerably good prophylactic efficacy (∼70% inhibition) against L. donovani challenge. The efficacy was confirmed by the increased expression levels of inducible NO synthase and Th1-type cytokines, IFN-γ and IL-12 and down-regulation of IL-4, IL-10 and transforming growth factor (TGF)-β. The results indicate the potentiality of rLdAdoHcy protein as a suitable vaccine candidate against VL. © 2016 British Society for Immunology.

Novel Arylimidamides for Treatment of Visceral Leishmaniasis▿ †

PubMed Central

Wang, Michael Zhuo; Zhu, Xiaohua; Srivastava, Anuradha; Liu, Qiang; Sweat, J. Mark; Pandharkar, Trupti; Stephens, Chad E.; Riccio, Ed; Parman, Toufan; Munde, Manoj; Mandal, Swati; Madhubala, Rentala; Tidwell, Richard R.; Wilson, W. David; Boykin, David W.; Hall, James Edwin; Kyle, Dennis E.; Werbovetz, Karl A.

2010-01-01

Arylimidamides (AIAs) represent a new class of molecules that exhibit potent antileishmanial activity (50% inhibitory concentration [IC50], <1 μM) against both Leishmania donovani axenic amastigotes and intracellular Leishmania, the causative agent for human visceral leishmaniasis (VL). A systematic lead discovery program was employed to characterize in vitro and in vivo antileishmanial activities, pharmacokinetics, mutagenicities, and toxicities of two novel AIAs, DB745 and DB766. They were exceptionally active (IC50 ≤ 0.12 μM) against intracellular L. donovani, Leishmania amazonensis, and Leishmania major and did not exhibit mutagenicity in an Ames screen. DB745 and DB766, given orally, produced a dose-dependent inhibition of liver parasitemia in two efficacy models, L. donovani-infected mice and hamsters. Most notably, DB766 (100 mg/kg of body weight/day for 5 days) reduced liver parasitemia in mice and hamsters by 71% and 89%, respectively. Marked reduction of parasitemia in the spleen (79%) and bone marrow (92%) of hamsters was also observed. Furthermore, these compounds distributed to target tissues (liver and spleen) and had a moderate oral bioavailability (up to 25%), a large volume of distribution, and an elimination half-life ranging from 1 to 2 days in mice. In a repeat-dose toxicity study of mice, there was no indication of liver or kidney toxicity for DB766 from serum chemistries, although mild hepatic cell eosinophilia, hypertrophy, and fatty changes were noted. These results demonstrated that arylimidamides are a promising class of molecules that possess good antileishmanial activity and desirable pharmacokinetics and should be considered for further preclinical development as an oral treatment for VL. PMID:20368397

Impact of phlebotomine sand flies on U.S. military operations at Tallil Air Base, Iraq: 4. Detection and identification of leishmania parasites in sand flies.

PubMed

Coleman, Russell E; Hochberg, Lisa P; Swanson, Katherine I; Lee, John S; McAvin, James C; Moulton, John K; Eddington, David O; Groebner, Jennifer L; O'Guinn, Monica L; Putnam, John L

2009-05-01

Sand flies collected between April 2003 and November 2004 at Tallil Air Base, Iraq, were evaluated for the presence of Leishmania parasites using a combination of a real-time Leishmania-generic polymerase chain reaction (PCR) assay and sequencing of a 360-bp fragment of the glucose-6-phosphate-isomerase (GPI) gene. A total of 2,505 pools containing 26,574 sand flies were tested using the real-time PCR assay. Leishmania DNA was initially detected in 536 pools; however, after extensive retesting with the real-time PCR assay, a total of 456 pools were considered positive and 80 were considered indeterminate. A total of 532 samples were evaluated for Leishmania GPI by sequencing, to include 439 PCR-positive samples, 80 PCR-indeterminate samples, and 13 PCR-negative samples. Leishmania GPI was detected in 284 samples that were sequenced, to include 281 (64%) of the PCR-positive samples and 3 (4%) of the PCR-indeterminate samples. Of the 284 sequences identified as Leishmania, 261 (91.9%) were L. tarentolae, 18 (6.3%) were L. donovani-complex parasites, 3 (1.1%) were L. tropica, and 2 were similar to both L. major and L. tropica. Minimum field infection rates were 0.09% for L. donovani-complex parasites, 0.02% for L. tropica, and 0.01% for the L. major/tropica-like parasite. Subsequent sequencing of a 600-bp region of the "Hyper" gene of 12 of the L. donovani-complex parasites showed that all 12 parasites were L. infantum. These data suggest that L. infantum was the primary leishmanial threat to U.S. military personnel deployed to Tallil Air Base. The implications of these findings are discussed.

Assessing the potential spread and maintenance of foot-and-mouth disease virus infection in wild ungulates: general principles and application to a specific scenario in Thrace.

PubMed

Dhollander, S; Belsham, G J; Lange, M; Willgert, K; Alexandrov, T; Chondrokouki, E; Depner, K; Khomenko, S; Özyörük, F; Salman, M; Thulke, H H; Bøtner, A

2016-04-01

Foot-and-mouth disease (FMD), due to infection with serotype O virus, occurred in wild boar and within eleven outbreaks in domestic livestock in the south-east of Bulgaria, Thrace region, in 2011. Hence, the issue of the potential for the spread and maintenance of FMD virus (FMDV) infection in a population of wild ungulates became important. This assessment focused on the spread and maintenance of FMDV infection within a hypothetical wild boar and deer population in an environment, which is characterized by a climate transitional between Mediterranean and continental and variable wildlife population densities. The assessment was based on three aspects: (i) a systematic review of the literature focusing on experimental infection studies to identify the parameters describing the duration of FMDV infection in deer and wild boar, as well as observational studies assessing the occurrence of FMDV infection in wild deer and wild boar populations, (ii) prevalence survey data of wild boar and deer in Bulgaria and Turkey and (iii) an epidemiological model, simulating the host-to-host spread of FMDV infections. It is concluded, based on all three aspects, that the wildlife population in Thrace, and so wildlife populations in similar ecological settings, are probably not able to maintain FMD in the long term in the absence of FMDV infection in the domestic host population. However, limited spread of FMDV infection in time and space in the wildlife populations can occur. If there is a continued cross-over of FMDV between domestic and wildlife populations or a higher population density, virus circulation may be prolonged. © 2014 Blackwell Verlag GmbH.

Visceral leishmaniasis with Roth spots

PubMed Central

Meena, Jagdish; Juneja, Monica; Mishra, Devendra; Vats, Pallavi; Pawaria, Arti

2014-01-01

Visceral leishmaniasis (VL) is caused by the protozoan parasite Leishmania donovani and transmitted by the bite of infected sandfly Phlebotomus argentipes. The protozoa is obliged intracellularly and causes a wide spectrum of clinical syndromes: VL (‘kala azar’), cutaneous leishmaniasis and mucocutaneous leishmaniasis (espundia). Kala azar is the most aggressive form and if untreated causes high mortality. Here, we describe a case of VL that presented to us with high-grade fever and found to have Roth spots that were resolved after 15 days of therapy. PMID:25988048

The Netherlands Chlamydia cohort study (NECCST) protocol to assess the risk of late complications following Chlamydia trachomatis infection in women.

PubMed

Hoenderboom, B M; van Oeffelen, A A M; van Benthem, B H B; van Bergen, J E A M; Dukers-Muijrers, N H T M; Götz, H M; Hoebe, C J P A; Hogewoning, A A; van der Klis, F R M; van Baarle, D; Land, J A; van der Sande, M A B; van Veen, M G; de Vries, F; Morré, S A; van den Broek, I V F

2017-04-11

Chlamydia trachomatis (CT), the most common bacterial sexually transmitted infection (STI) among young women, can result in serious sequelae. Although the course of infection is often asymptomatic, CT may cause pelvic inflammatory disease (PID), leading to severe complications, such as prolonged time to pregnancy, ectopic pregnancy, and tubal factor subfertility. The risk of and risk factors for complications following CT-infection have not been assessed in a long-term prospective cohort study, the preferred design to define infections and complications adequately. In the Netherlands Chlamydia Cohort Study (NECCST), a cohort of women of reproductive age with and without a history of CT-infection is followed over a minimum of ten years to investigate (CT-related) reproductive tract complications. This study is a follow-up of the Chlamydia Screening Implementation (CSI) study, executed between 2008 and 2011 in the Netherlands. For NECCST, female CSI participants who consented to be approached for follow-up studies (n = 14,685) are invited, and prospectively followed until 2022. Four data collection moments are foreseen every two consecutive years. Questionnaire data and blood samples for CT-Immunoglobulin G (IgG) measurement are obtained as well as host DNA to determine specific genetic biomarkers related to susceptibility and severity of infection. CT-history will be based on CSI test outcomes, self-reported infections and CT-IgG presence. Information on (time to) pregnancies and the potential long-term complications (i.e. PID, ectopic pregnancy and (tubal factor) subfertility), will be acquired by questionnaires. Reported subfertility will be verified in medical registers. Occurrence of these late complications and prolonged time to pregnancy, as a proxy for reduced fertility due to a previous CT-infection, or other risk factors, will be investigated using longitudinal statistical procedures. In the proposed study, the occurrence of late complications following

Assessing immune aging in HIV-infected patients

PubMed Central

Appay, Victor; Sauce, Delphine

2017-01-01

ABSTRACT Many of the alterations that affect innate and adaptive immune cell compartments in HIV-infected patients are reminiscent of the process of immune aging, characteristic of old age. These alterations define the immunological age of individuals and are likely to participate to the decline of immune competence with HIV disease progression. It is therefore important to characterize these changes, which point toward the accumulation of highly differentiated immunocompetent cells, associated with overall telomere length shortening, as well as understanding their etiology, especially related to the impact of chronic immune activation. Particular attention should be given to the exhaustion of primary immune resources, including haematopoietic progenitors and naïve cells, which holds the key for effective hematopoiesis and immune response induction, respectively. The alteration of these compartments during HIV infection certainly represents the foundation of the immune parallel with aging. PMID:27310730

Comparison of Individual and Pooled Stool Samples for the Assessment of Soil-Transmitted Helminth Infection Intensity and Drug Efficacy

PubMed Central

Mekonnen, Zeleke; Meka, Selima; Ayana, Mio; Bogers, Johannes; Vercruysse, Jozef; Levecke, Bruno

2013-01-01

Background In veterinary parasitology samples are often pooled for a rapid assessment of infection intensity and drug efficacy. Currently, studies evaluating this strategy in large-scale drug administration programs to control human soil-transmitted helminths (STHs; Ascaris lumbricoides, Trichuris trichiura, and hookworm), are absent. Therefore, we developed and evaluated a pooling strategy to assess intensity of STH infections and drug efficacy. Methods/Principal Findings Stool samples from 840 children attending 14 primary schools in Jimma, Ethiopia were pooled (pool sizes of 10, 20, and 60) to evaluate the infection intensity of STHs. In addition, the efficacy of a single dose of mebendazole (500 mg) in terms of fecal egg count reduction (FECR; synonym of egg reduction rate) was evaluated in 600 children from two of these schools. Individual and pooled samples were examined with the McMaster egg counting method. For each of the three STHs, we found a significant positive correlation between mean fecal egg counts (FECs) of individual stool samples and FEC of pooled stool samples, ranging from 0.62 to 0.98. Only for A. lumbricoides was any significant difference in mean FEC of the individual and pooled samples found. For this STH species, pools of 60 samples resulted in significantly higher FECs. FECR for the different number of samples pooled was comparable in all pool sizes, except for hookworm. For this parasite, pools of 10 and 60 samples provided significantly higher FECR results. Conclusion/Significance This study highlights that pooling stool samples holds promise as a strategy for rapidly assessing infection intensity and efficacy of administered drugs in programs to control human STHs. However, further research is required to determine when and how pooling of stool samples can be cost-effectively applied along a control program, and to verify whether this approach is also applicable to other NTDs. PMID:23696905

Sequential Acquisition of Anal Human Papillomavirus (HPV) Infection Following Genital Infection Among Men Who Have Sex With Women: The HPV Infection in Men (HIM) Study

PubMed Central

Pamnani, Shitaldas J.; Nyitray, Alan G.; Abrahamsen, Martha; Rollison, Dana E.; Villa, Luisa L.; Lazcano-Ponce, Eduardo; Huang, Yangxin; Borenstein, Amy; Giuliano, Anna R.

2016-01-01

Background. The purpose of this study was to assess the risk of sequential acquisition of anal human papillomavirus (HPV) infection following a type-specific genital HPV infection for the 9-valent vaccine HPV types and investigate factors associated with sequential infection among men who have sex with women (MSW). Methods. Genital and anal specimens were available for 1348 MSW participants, and HPV genotypes were detected using the Roche Linear Array assay. Sequential risk of anal HPV infection was assessed using hazard ratios (HRs) among men with prior genital infection, compared with men with no prior genital infection, in individual HPV type and grouped HPV analyses. Results. In individual analyses, men with prior HPV 16 genital infections had a significantly higher risk of subsequent anal HPV 16 infections (HR, 4.63; 95% confidence interval [CI], 1.41–15.23). In grouped analyses, a significantly higher risk of sequential type-specific anal HPV infections was observed for any of the 9 types (adjusted HR, 2.80; 95% CI, 1.32–5.99), high-risk types (adjusted HR, 2.65; 95% CI, 1.26, 5.55), and low-risk types (adjusted HR, 5.89; 95% CI, 1.29, 27.01). Conclusions. MSW with prior genital HPV infections had a higher risk of a subsequent type-specific anal infection. The higher risk was not explained by sexual intercourse with female partners. Autoinoculation is a possible mechanism for the observed association. PMID:27489298

Detection of Mixed Infection from Bacterial Whole Genome Sequence Data Allows Assessment of Its Role in Clostridium difficile Transmission

PubMed Central

Eyre, David W.; Cule, Madeleine L.; Griffiths, David; Crook, Derrick W.; Peto, Tim E. A.

2013-01-01

the pairs of cases under investigation. These results demonstrate that mixed infections can be detected without additional sequencing effort, and this will be important in assessing the extent of cryptic transmission in our hospitals. PMID:23658511

Vaccination Programs for Endemic Infections: Modelling Real versus Apparent Impacts of Vaccine and Infection Characteristics

NASA Astrophysics Data System (ADS)

Ragonnet, Romain; Trauer, James M.; Denholm, Justin T.; Geard, Nicholas L.; Hellard, Margaret; McBryde, Emma S.

2015-10-01

Vaccine effect, as measured in clinical trials, may not accurately reflect population-level impact. Furthermore, little is known about how sensitive apparent or real vaccine impacts are to factors such as the risk of re-infection or the mechanism of protection. We present a dynamic compartmental model to simulate vaccination for endemic infections. Several measures of effectiveness are calculated to compare the real and apparent impact of vaccination, and assess the effect of a range of infection and vaccine characteristics on these measures. Although broadly correlated, measures of real and apparent vaccine effectiveness can differ widely. Vaccine impact is markedly underestimated when primary infection provides partial natural immunity, when coverage is high and when post-vaccination infectiousness is reduced. Despite equivalent efficacy, ‘all or nothing’ vaccines are more effective than ‘leaky’ vaccines, particularly in settings with high risk of re-infection and transmissibility. Latent periods result in greater real impacts when risk of re-infection is high, but this effect diminishes if partial natural immunity is assumed. Assessments of population-level vaccine effects against endemic infections from clinical trials may be significantly biased, and vaccine and infection characteristics should be considered when modelling outcomes of vaccination programs, as their impact may be dramatic.

Vaccination Programs for Endemic Infections: Modelling Real versus Apparent Impacts of Vaccine and Infection Characteristics

PubMed Central

Ragonnet, Romain; Trauer, James M.; Denholm, Justin T.; Geard, Nicholas L.; Hellard, Margaret; McBryde, Emma S.

2015-01-01

Vaccine effect, as measured in clinical trials, may not accurately reflect population-level impact. Furthermore, little is known about how sensitive apparent or real vaccine impacts are to factors such as the risk of re-infection or the mechanism of protection. We present a dynamic compartmental model to simulate vaccination for endemic infections. Several measures of effectiveness are calculated to compare the real and apparent impact of vaccination, and assess the effect of a range of infection and vaccine characteristics on these measures. Although broadly correlated, measures of real and apparent vaccine effectiveness can differ widely. Vaccine impact is markedly underestimated when primary infection provides partial natural immunity, when coverage is high and when post-vaccination infectiousness is reduced. Despite equivalent efficacy, ‘all or nothing’ vaccines are more effective than ‘leaky’ vaccines, particularly in settings with high risk of re-infection and transmissibility. Latent periods result in greater real impacts when risk of re-infection is high, but this effect diminishes if partial natural immunity is assumed. Assessments of population-level vaccine effects against endemic infections from clinical trials may be significantly biased, and vaccine and infection characteristics should be considered when modelling outcomes of vaccination programs, as their impact may be dramatic. PMID:26482413

Assessment of micafungin regimens by pharmacokinetic-pharmacodynamic analysis: a dosing strategy for Aspergillus infections.

PubMed

Ikawa, Kazuro; Nomura, Kenichi; Morikawa, Norifumi; Ikeda, Kayo; Taniwaki, Masafumi

2009-10-01

A pharmacokinetic (PK)-pharmacodynamic (PD) analysis was conducted to assess various micafungin regimens for Candida and Aspergillus infections, as appropriate regimens have not been established, especially for Aspergillus infections. Plasma drug concentrations (48 samples from 10 adult patients with haematological malignancies) were determined chromatographically, and used for population PK modelling and Monte Carlo simulation to evaluate the ability of regimens (1 h infusions) to attain genus-dependent PK-PD targets, namely fungistatic and fungicidal targets against Candida spp. [area under the plasma unbound (1%) drug concentration-time curve over 24 h/MIC (fAUC/MIC) = 10 and 20] and an effective concentration target against Aspergillus spp. (plasma unbound drug concentration = 0.05 mg/L). Mean (variance) values for two-compartment PK model parameters were: clearance, 0.762 L/h (15.4%); volume of central compartment, 9.25 L (24.6%); intercompartmental clearance, 7.02 L/h (fixed); and volume of peripheral compartment, 8.86 L (71.8%). The Monte Carlo simulation demonstrated that 50 mg once daily and 100 mg once daily for the fungistatic and fungicidal targets achieved a >95% probability of target attainment against Candida spp. To achieve such probability against Aspergillus spp., 250 mg once daily or 100 mg twice daily was required. These results rationalize the approved micafungin dosages for Candida infections (50 mg once daily for prophylaxis and 100-150 mg once daily for treatment), and on the basis of these results we propose a PK-PD-based dosing strategy for Aspergillus infections. A regimen of 200-250 mg/day should be initiated to ensure the likelihood of a favourable outcome. The regimen can be optimized by decreasing the dosing interval.

Neuropsychological Impact of West Nile Virus Infection: An Extensive Neuropsychiatric Assessment of 49 Cases in Canada.

PubMed

Samaan, Zainab; McDermid Vaz, Stephanie; Bawor, Monica; Potter, Tammy Hlywka; Eskandarian, Sasha; Loeb, Mark

2016-01-01

West Nile virus emerged as an important human pathogen in North America and continues to pose a risk to public health. It can cause a highly variable range of clinical manifestations ranging from asymptomatic to severe illness. Neuroinvasive disease due to West Nile virus can lead to long-term neurological deficits and psychological impairment. However, these deficits have not been well described. The objective of this study was to characterize the neuropsychological manifestations of West Nile virus infection with a focus on neuroinvasive status and time since infection. Patients from Ontario Canada with a diagnosis of neuroinvasive disease (meningitis, encephalitis, or acute flaccid paralysis) and non-neuroinvasive disease who had participated in a cohort study were enrolled. Clinical and laboratory were collected, as well as demographics and medical history. Cognitive functioning was assessed using a comprehensive battery of neuropsychological tests. Data from 49 individuals (32 with West Nile fever and 17 with West Nile neuroinvasive disease) were included in the present cross-sectional analysis. Patterns of neuropsychological impairment were comparable across participants with both neuroinvasive and non-neuroinvasive West Nile virus infection on all cognitive measures. Neuropsychiatric impairment was also observed more frequently at two to four years post-infection compared to earlier stages of illness. Our data provide objective evidence for cognitive difficulties among patients who were infected with West Nile virus; these deficits appear to manifest regardless of severity of West Nile virus infection (West Nile fever vs. West Nile neuroinvasive disease), and are more prevalent with increasing illness duration (2-4 years vs. 1 month). Data from this study will help inform patients and healthcare providers about the expected course of recovery, as well as the need to implement effective treatment strategies that include neuropsychological interventions.

Assessing pharmacists' readiness to prescribe oral antibiotics for limited infections using a case-vignette technique.

PubMed

Ung, Elizabeth; Czarniak, Petra; Sunderland, Bruce; Parsons, Richard; Hoti, Kreshnik

2017-02-01

Background Pharmacist's skills are underutilized whilst they are directly involved with antibiotic supply to the community. Addressing this issue could lead to better use of antibiotics and hence decreased resistance. Objective Explore how pharmacists can prescribe oral antibiotics to treat a limited range of infections whilst focusing on their confidence and appropriateness of prescribing. Setting Community pharmacies, Western Australia. Method Data were collected using a self-administered questionnaire also containing case vignettes. These were distributed to a random sample of metropolitan and rural community pharmacies in Western Australia. A Generalised Estimating Equation was used to compare respondents' level of confidence in treating various infections and to assess appropriateness of prescribing. Main outcome measure Appropriateness and confidence of antibiotic prescribing. Results A response rate of 34.2% (i.e. 425 responses to case vignettes) was achieved from 240 pharmacies. There were high levels of confidence to treat simple infections such as uncomplicated UTIs (n = 73; 89.0%), impetigo (n = 65; 79.3%), mild bacterial skin infections (n = 62; 75.6%) and moderate acne (n = 61; 72.4%). Over 80% of respondents were confident to prescribe amoxicillin (n = 73; 89%), trimethoprim (n = 72; 87.8%), amoxicillin and clavulanic acid (n = 70; 85.4%), flucloxacillin (n = 70; 85.4%) and cephalexin (n = 68; 82.9%). High levels of appropriate antibiotic prescribing were shown for uncomplicated UTI (97.2%), cellulitis (98.2%) and adolescent acne (100.0%). Conclusion This study identified key limited infections and antibiotics for which pharmacists were supportive and confident to prescribe. This role could lead to better use of antibiotics in the community and minimisation of resistance.

Sequential Acquisition of Anal Human Papillomavirus (HPV) Infection Following Genital Infection Among Men Who Have Sex With Women: The HPV Infection in Men (HIM) Study.

PubMed

Pamnani, Shitaldas J; Nyitray, Alan G; Abrahamsen, Martha; Rollison, Dana E; Villa, Luisa L; Lazcano-Ponce, Eduardo; Huang, Yangxin; Borenstein, Amy; Giuliano, Anna R

2016-10-15

The purpose of this study was to assess the risk of sequential acquisition of anal human papillomavirus (HPV) infection following a type-specific genital HPV infection for the 9-valent vaccine HPV types and investigate factors associated with sequential infection among men who have sex with women (MSW). Genital and anal specimens were available for 1348 MSW participants, and HPV genotypes were detected using the Roche Linear Array assay. Sequential risk of anal HPV infection was assessed using hazard ratios (HRs) among men with prior genital infection, compared with men with no prior genital infection, in individual HPV type and grouped HPV analyses. In individual analyses, men with prior HPV 16 genital infections had a significantly higher risk of subsequent anal HPV 16 infections (HR, 4.63; 95% confidence interval [CI], 1.41-15.23). In grouped analyses, a significantly higher risk of sequential type-specific anal HPV infections was observed for any of the 9 types (adjusted HR, 2.80; 95% CI, 1.32-5.99), high-risk types (adjusted HR, 2.65; 95% CI, 1.26, 5.55), and low-risk types (adjusted HR, 5.89; 95% CI, 1.29, 27.01). MSW with prior genital HPV infections had a higher risk of a subsequent type-specific anal infection. The higher risk was not explained by sexual intercourse with female partners. Autoinoculation is a possible mechanism for the observed association. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

First Molecular Characterization of Leishmania Species Causing Visceral Leishmaniasis among Children in Yemen

PubMed Central

Mahdy, Mohammed A. K.; Al-Mekhlafi, Abdulsalam M.; Abdul-Ghani, Rashad; Saif-Ali, Reyadh; Al-Mekhlafi, Hesham M.; Al-Eryani, Samira M.; Lim, Yvonne A. L.; Mahmud, Rohela

2016-01-01

Visceral leishmaniasis (VL) is a debilitating, often fatal disease caused by Leishmania donovani complex; however, it is a neglected tropical disease. L. donovani complex comprises two closely related species, L. donovani that is mostly anthroponotic and L. infantum that is zoonotic. Differentiation between these two species is critical due to the differences in their epidemiology and pathology. However, they cannot be differentiated morphologically, and their speciation using isoenzyme-based methods poses a difficult task and may be unreliable. Molecular characterization is now the most reliable method to differentiate between them and to determine their phylogenetic relationships. The present study aims to characterize Leishmania species isolated from bone marrows of Yemeni pediatric patients using sequence analysis of the ribosomal internal transcribed spacer-1 (ITS1) gene. Out of 41 isolates from Giemsa-stained bone marrow smears, 25 isolates were successfully amplified by nested polymerase chain reaction and sequenced in both directions. Phylogenetic analysis using neighbor joining method placed all study isolates in one cluster with L. donovani complex (99% bootstrap). The analysis of ITS1 for microsatellite repeat numbers identified L. infantum in 11 isolates and L. donovani in 14 isolates. These data suggest the possibility of both anthroponotic and zoonotic transmission of VL-causing Leishmania species in Yemen. Exploring the possible animal reservoir hosts is therefore needed for effective control to be achieved. PMID:26966902

Infectivity of Plasmodium falciparum sporozoites determines emerging parasitemia in infected volunteers.

PubMed

McCall, Matthew B B; Wammes, Linda J; Langenberg, Marijke C C; van Gemert, Geert-Jan; Walk, Jona; Hermsen, Cornelus C; Graumans, Wouter; Koelewijn, Rob; Franetich, Jean-François; Chishimba, Sandra; Gerdsen, Max; Lorthiois, Audrey; van de Vegte, Marga; Mazier, Dominique; Bijker, Else M; van Hellemond, Jaap J; van Genderen, Perry J J; Sauerwein, Robert W

2017-06-21

Malaria sporozoites must first undergo intrahepatic development before a pathogenic blood-stage infection is established. The success of infection depends on host and parasite factors. In healthy human volunteers undergoing controlled human malaria infection (CHMI), we directly compared three clinical Plasmodium falciparum isolates for their ability to infect primary human hepatocytes in vitro and to drive the production of blood-stage parasites in vivo. Our data show a correlation between the efficiency of strain-specific sporozoite invasion of human hepatocytes and the dynamics of patent parasitemia in study subjects, highlighting intrinsic differences in infectivity among P. falciparum isolates from distinct geographical locales. The observed heterogeneity in infectivity among strains underscores the value of assessing the protective efficacy of candidate malaria vaccines against heterologous strains in the CHMI model. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Domestic Animals and Epidemiology of Visceral Leishmaniasis, Nepal

PubMed Central

Bhattarai, Narayan Raj; Van der Auwera, Gert; Rijal, Suman; Picado, Albert; Speybroeck, Niko; Khanal, Basudha; De Doncker, Simonne; Das, Murari Lal; Ostyn, Bart; Davies, Clive; Coosemans, Marc; Berkvens, Dirk; Boelaert, Marleen

2010-01-01

On the Indian subcontinent, visceral leishmaniasis (VL) is considered an anthroponosis. To determine possible reasons for its persistence during interepidemic periods, we mapped Leishmania infections among healthy persons and animals in an area of active VL transmission in Nepal. During 4 months (September 2007–February 2008), blood was collected from persons, goats, cows, and buffaloes in 1 village. Leishmania infections were determined by using PCR. We found infections among persons (6.1%), cows (5%), buffaloes (4%), and goats (16%). Data were georeferenced and entered into a geographic information system. The bivariate K-function results indicated spatial clustering of Leishmania spp.–positive persons and domestic animals. Classification tree analysis determined that among several possible risk factors for Leishmania infection among persons, proximity of Leishmania spp.–positive goats ranked first. Although our data do not necessarily mean that goats constitute a reservoir host of L. donovani, these observations indicate the need for further investigation of goats’ possible role in VL transmission. PMID:20113552

Assessing the Risks of West Nile Virus–Infected Mosquitoes from Transatlantic Aircraft: Implications for Disease Emergence in the United Kingdom

PubMed Central

Brown, Eleanor B.E.; Adkin, Amie; Fooks, Anthony R.; Stephenson, Ben; Medlock, Jolyon M.

2012-01-01

Abstract The number of West Nile virus (WNV)–infected mosquitoes aboard aircraft from the United States that arrive in the United Kingdom each summer was determined using a quantitative risk assessment. In the worst-case scenario, when WNV levels in mosquitoes are high (at epidemic levels) the probability of at least one WNV-infected mosquito being introduced into the United Kingdom was predicted to be 0.99. During these periods, a mean of 5.2 infected mosquitoes were estimated to be aboard flights from the United States to the United Kingdom during May to October, with 90% certainty that the exact value lies between one and ten mosquitoes. Heathrow airport was predicted to receive the majority of the infected mosquitoes (72.1%). Spatial analysis revealed the region surrounding Heathrow satisfies the criteria for potential WNV exposure as both WNV-competent mosquitoes and susceptible wild bird species are present. This region is, therefore, recommended for targeted, risk-based surveillance of WNV-infected mosquitoes in addition to an increased awareness of the risks to horses, birds and humans. PMID:22217181

Anal Human Papillomavirus Infection among HIV-Infected Men in Korea

PubMed Central

Lee, Chang Hun; Lee, Sun Hee; Lee, Shinwon; Cho, Heerim; Kim, Kye-Hyung; Lee, Jung Eun; Jung, Eun ju; Lee, Su jin; Kim, Eun Jung; Kim, Ki Hyung; Moon, Eunsoo; Cho, Hong Je

2016-01-01

Background Little is known about the epidemiology on human papillomavirus (HPV) infection among HIV-infected men in Korea. The objective of this study was to determine the prevalence, genotype distribution and risk factors associated with anal HPV infection among HIV-infected men in Korea. Methods A single-center cross-sectional study was conducted with HIV-infected men in Korea. Participants completed a detailed sexual behavior risk factor questionnaire. Anal samples were collected for cytology and HPV genotyping. Factors associated with anal HPV infection were assessed using multivariable logistic regression, stratifying by sexual behaviour. Results A total of 201 HIV-infected men were included in the study: 133 were from men who have sex with men (MSM) and 68 from men who have sex with women (MSW). Any anal HPV infection was detected in 82.7% of HIV-infected MSM and in 51.5% of HIV- infected MSW (P < 0.001). High-risk HPV (HR-HPV) prevalence was higher among MSM (47.4%) than MSW (25.0%; P = 0.002). The HR-HPV types identified most frequently were HPV 16 (11%), HPV 18 (9.9%), and HPV 58 (5%) in MSM, and HPV 58(11%) and HPV 16 (8.9%) in MSW. Prevalence of any HPV types in 9-valent vaccine types was higher among MSM than MSW (47.4% vs 22.1%. P = 0.001). Abnormal anal cytology was more commonly detected in MSM than MSW (42.9% vs.19.1%, P < 0.001). In HIV-infected MSM, higher number of lifetime male sex partners was significantly associated with any anal HPV infection, but age was a significant risk factor associated with anal HR-HPV infection. Conclusion Anal HPV infection was highly prevalent in HIV-infected MSM in Korea, and also commonly found in HIV-infected MSW. In HIV-infected MSM, the significant risk factor for being infected with any HPV infection was lifetime number of male sexual partners, and with anal oncogenic HPV infection was age. PMID:27548632

Anal Human Papillomavirus Infection among HIV-Infected Men in Korea.

PubMed

Lee, Chang Hun; Lee, Sun Hee; Lee, Shinwon; Cho, Heerim; Kim, Kye-Hyung; Lee, Jung Eun; Jung, Eun Ju; Lee, Su Jin; Kim, Eun Jung; Kim, Ki Hyung; Moon, Eunsoo; Cho, Hong Je

2016-01-01

Little is known about the epidemiology on human papillomavirus (HPV) infection among HIV-infected men in Korea. The objective of this study was to determine the prevalence, genotype distribution and risk factors associated with anal HPV infection among HIV-infected men in Korea. A single-center cross-sectional study was conducted with HIV-infected men in Korea. Participants completed a detailed sexual behavior risk factor questionnaire. Anal samples were collected for cytology and HPV genotyping. Factors associated with anal HPV infection were assessed using multivariable logistic regression, stratifying by sexual behaviour. A total of 201 HIV-infected men were included in the study: 133 were from men who have sex with men (MSM) and 68 from men who have sex with women (MSW). Any anal HPV infection was detected in 82.7% of HIV-infected MSM and in 51.5% of HIV- infected MSW (P < 0.001). High-risk HPV (HR-HPV) prevalence was higher among MSM (47.4%) than MSW (25.0%; P = 0.002). The HR-HPV types identified most frequently were HPV 16 (11%), HPV 18 (9.9%), and HPV 58 (5%) in MSM, and HPV 58(11%) and HPV 16 (8.9%) in MSW. Prevalence of any HPV types in 9-valent vaccine types was higher among MSM than MSW (47.4% vs 22.1%. P = 0.001). Abnormal anal cytology was more commonly detected in MSM than MSW (42.9% vs.19.1%, P < 0.001). In HIV-infected MSM, higher number of lifetime male sex partners was significantly associated with any anal HPV infection, but age was a significant risk factor associated with anal HR-HPV infection. Anal HPV infection was highly prevalent in HIV-infected MSM in Korea, and also commonly found in HIV-infected MSW. In HIV-infected MSM, the significant risk factor for being infected with any HPV infection was lifetime number of male sexual partners, and with anal oncogenic HPV infection was age.

Endemic Transmission of Visceral Leishmaniasis in Bhutan

PubMed Central

Yangzom, Thinley; Cruz, Israel; Bern, Caryn; Argaw, Daniel; den Boer, Margriet; Vélez, Iván Dario; Bhattacharya, Sujit K.; Molina, Ricardo; Alvar, Jorge

2012-01-01

Visceral leishmaniasis was first reported in Bhutan in 2006. We conducted studies of the parasite, possible vectors and reservoirs, and leishmanin skin test and risk factor surveys in three villages. Nineteen cases were reported from seven districts. Parasite typing yielded two novel microsatellite sequences, both related to Indian L. donovani. In one case village, 40 (18.5%) of 216 participants had positive leishmanin skin test results, compared with 3 (4.2%) of 72 in the other case village and 0 of 108 in the control village. Positive results were strongly associated with the village and increasing age. None of the tested dogs were infected. Eighteen sand flies were collected, 13 Phlebotomus species and 5 Sergentomyia species; polymerase chain reaction for leishmanial DNA was negative. This assessment suggests that endemic visceral leishmaniasis transmission has occurred in diverse locations in Bhutan. Surveillance, case investigations, and further parasite, vector, and reservoir studies are needed. The potential protective impact of bed nets should be evaluated. PMID:23091191

Impact of cleaning and other interventions on the reduction of hospital-acquired Clostridium difficile infections in two hospitals in England assessed using a breakpoint model.

PubMed

Hughes, G J; Nickerson, E; Enoch, D A; Ahluwalia, J; Wilkinson, C; Ayers, R; Brown, N M

2013-07-01

Clostridium difficile infection remains a major challenge for hospitals. Although targeted infection control initiatives have been shown to be effective in reducing the incidence of hospital-acquired C. difficile infection, there is little evidence available to assess the effectiveness of specific interventions. To use statistical modelling to detect substantial reductions in the incidence of C. difficile from time series data from two hospitals in England, and relate these time points to infection control interventions. A statistical breakpoints model was fitted to likely hospital-acquired C. difficile infection incidence data from a teaching hospital (2002-2009) and a district general hospital (2005-2009) in England. Models with increasing complexity (i.e. increasing the number of breakpoints) were tested for an improved fit to the data. Partitions estimated from breakpoint models were tested for individual stability using statistical process control charts. Major infection control interventions from both hospitals during this time were grouped according to their primary target (antibiotics, cleaning, isolation, other) and mapped to the model-suggested breakpoints. For both hospitals, breakpoints coincided with enhancements to cleaning protocols. Statistical models enabled formal assessment of the impact of different interventions, and showed that enhancements to deep cleaning programmes are the interventions that have most likely led to substantial reductions in hospital-acquired C. difficile infections at the two hospitals studied. Copyright © 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Assessing the infection risk of enteropathogens from consumption of raw vegetables washed with contaminated water in Kathmandu Valley, Nepal.

PubMed

Shrestha, S; Haramoto, E; Shindo, J

2017-11-01

To assess diarrhoeal risks from enteropathogenic Escherichia coli, Giardia and Cryptosporidium from consuming raw spinach, cabbage, carrots and tomatoes in Kathmandu Valley, Nepal. The annual infection risk was quantified using the probabilistic Quantitative Microbial Risk Assessment approach, which considered 12 vegetable washing combinations. A new model was used to estimate dose of pathogens per exposure comprising parameters such as pathogen concentration in vegetable wash water before selling and eating, vegetable consumption rate, remaining pathogen ratio after washing, remaining water on vegetables after washing and water treatment removal efficiency. When all washing combinations were considered, high infection risks above the acceptable level of -4 log 10 infection per person per year were obtained, whereas the risk was reduced when other sources excluding river water were used. Assuming use of water treated with ceramic filters by all consumers, a 0-2 log 10 reduction in the estimated risks was obtained, which was insufficient to achieve the required risk level. High risk of diarrhoea prevails among raw vegetable consumers in the valley. It is needed to protect vegetable washing water sources and establish advanced water treatment methods to achieve the required level of public health risk. © 2017 The Society for Applied Microbiology.

Comparison of three blood transfusion guidelines applied to 31 feline donors to minimise the risk of transfusion-transmissible infections.

PubMed

Marenzoni, Maria Luisa; Lauzi, Stefania; Miglio, Arianna; Coletti, Mauro; Arbia, Andrea; Paltrinieri, Saverio; Antognoni, Maria Teresa

2017-08-01

Objectives The increased demand for animal blood transfusions creates the need for an adequate number of donors. At the same time, a high level of blood safety must be guaranteed and different guidelines (GLs) deal with this topic. The aim of this study was to evaluate the appropriateness of different GLs in preventing transfusion-transmissible infections (TTI) in Italian feline blood donors. Methods Blood samples were collected from 31 cats enrolled as blood donors by the owners' voluntary choice over a period of approximately 1 year. Possible risk factors for TTI were recorded. Based on Italian, European and American GLs, specific TTI, including haemoplasmas, feline leukaemia virus (FeLV), feline immunodeficiency virus (FIV), Anaplasma phagocytophilum, Ehrlichia species, Bartonella species, Babesia species, Theileria species, Cytauxzoon species, Leishmania donovani sensu lato and feline coronavirus (FCoV) were screened. Rapid antigen and serological tests and biomolecular investigations (PCR) were used. Several PCR protocols for haemoplasma and FeLV DNA were compared. Results The presence of at least one recognised risk factor for TTI was reported in all cats. Results for FIV and FeLV infections were negative using rapid tests, whereas five (16.1%) cats were positive for FCoV antibodies. Four (12.9%) cats were PCR positive for haemoplasma DNA and one (3.2%) for FeLV provirus, the latter being positive only using the most sensitive PCR protocol applied. Other TTI were not detected using PCR. Conclusions and relevance Blood safety increases by combining the recommendations of different GLs. To reduce the risk of TTI, sensitive tests are needed and the choice of the best protocol is a critical step in improving blood safety. The cost and time of the screening procedures may be reduced if appropriate tests are selected. To this end, the GLs should include appropriate recruitment protocols and questionnaire-based risk profiles to identify suitable donors.

Vaccination with liposomal leishmanial antigens adjuvanted with monophosphoryl lipid-trehalose dicorynomycolate (MPL-TDM) confers long-term protection against visceral leishmaniasis through a human administrable route.

PubMed

Ravindran, Rajesh; Maji, Mithun; Ali, Nahid

2012-01-01

The development of a long-term protective subunit vaccine against visceral leishmaniasis depends on antigens and adjuvants that can induce an appropriate immune response. The immunization of leishmanial antigens alone shows limited efficacy in the absence of an appropriate adjuvant. Earlier we demonstrated sustained protection against Leishmania donovani with leishmanial antigens entrapped in cationic liposomes through an intraperitoneal route. However, this route is not applicable for human administration. Herein, we therefore evaluated the immune response and protection induced by liposomal soluble leishmanial antigen (SLA) formulated with monophosphoryl lipid-trehalose dicorynomycolate (MPL-TDM) through a subcutaneous route. Subcutaneous immunization of BALB/c mice with SLA entrapped in liposomes or with MPL-TDM elicited partial protection against experimental visceral leishmaniasis. In contrast, liposomal SLA adjuvanted with MPL-TDM induced significantly higher levels of protection in liver and spleen in BALB/c mice challenged 10 days post-vaccination. Protection conferred by this formulation was sustained up to 12 weeks of immunization, and infection was controlled for at least 4 months of the challenge, similar to liposomal SLA immunization administered intraperitoneally. An analysis of cellular immune responses of liposomal SLA + MPL-TDM immunized mice demonstrated the induction of IFN-γ and IgG2a antibody production not only 10 days or 12 weeks post-vaccination but also 4 months after the challenge infection and a down regulation of IL-4 production after infection. Moreover, long-term immunity elicited by this formulation was associated with IFN-γ production also by CD8⁺ T cells. Taken together, our results suggest that liposomal SLA + MPL-TDM represent a good vaccine formulation for the induction of durable protection against L. donovani through a human administrable route.

Certification in infection control matters: Impact of infection control department characteristics and policies on rates of multidrug-resistant infections

PubMed Central

Pogorzelska, Monika; Stone, PatriciaW.; Larson, Elaine L.

2012-01-01

Background The study objective is to describe infection control policies aimed at multidrug-resistant organisms (MDRO) in California hospitals and assess the relationship among these policies, structural characteristics, and rates of methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE) bloodstream infections and Clostridium difficile infections. Methods Data on infection control policies, structural characteristics, and MDRO rates were collected through a 2010 survey of California infection control departments. Bivariate and multivariable Poisson and negative binomial regressions were conducted. Results One hundred eighty hospitals provided data (response rate, 54%). Targeted MRSA screening upon admission was reported by the majority of hospitals (87%). The majority of hospitals implemented contact precautions for confirmed MDRO and C difficile patients; presumptive isolation/contact precautions for patients with pending screens were less frequently implemented. Few infection control policies were associated with lower MDRO rates. Hospitals with a certified infection control director had significantly lower rates of MRSA bloodstream infections (P < .05). Conclusion Although most California hospitals are involved in activities to decrease MDRO, there is variation in specific activities utilized with the most focus placed on MRSA. This study highlights the importance of certification and its significant impact on infection rates. Additional research is needed to confirm these findings. PMID:22381222

Design, synthesis and biological evaluation of piperazinyl-β-carbolinederivatives as anti-leishmanial agents.

PubMed

Ashok, Penta; Chander, Subhash; Smith, Terry K; Sankaranarayanan, Murugesan

2018-04-25

Molecular hybridization is a ligand based drug design approach is well known recent medicinal chemistry to design anti-parasitic agents. In the present study, we have designed a series of (1-phenyl-9H-pyrido [3,4-b]indol-3-yl) (4-phenylpiperazin-1-yl)methanone derivatives using molecular hybridization approach. Designed analogues were evaluated for cytotoxicity and inhibition activity against Leishmania infantum and Leishmania donovani. Among these reported analogues 7b, 7d, 7e, 7f and 7m displayed potent inhibition of both L. infantum and L. donovani. Compounds 7i and 7k exhibited selective potent inhibition of L. donovani. Especially, compounds 7e and 7k showed most potent anti-leishmanial activity against L. infantum and L. donovani respectively. Anti-leishmanial activity of these compounds is comparable with standard drugs miltefosine and pentamidine. SAR studies revealed that, electron donating group substitution on phenyl ring recommended for potent anti-leishmanial activity. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Assessment of theileria equi and babesia caballi infections in equine populations in Egypt by molecular, serological and hematological approaches

USDA-ARS?s Scientific Manuscript database

Background: Equine piroplasmosis caused by Theileria equi, Babesia caballi, or both, cause significant economic losses in the equine industry and remains uncontrolled in Egypt. Methods: T. equi and B. caballi infections were assessed in blood from 88 horses and 51 donkeys from different localities ...

[Topical immunomodulation in the treatment of herpetic infections in HIV-infected patients].

PubMed

Shul'diakov, A A; Barkhatova, T S; Zubareva, E V; Satarova, S A; Perminova, T A

2012-01-01

The efficiency of cycloferon liniment in combined treatment of herpetic infection in patients with latent form of HIV infection has been assess by observations of 40 patients divided into two groups. In the first group, the standard treatment was supplemented with the application of cycloferon liniment twice a day during 7 days; in the second group, the therapy was conducted according to standard recommendations. It was established that the application of cycloferon liniment in combination with standard therapy in patients with relapse of herpetic infection against the background of HIV infection ensures faster disappearance of general infectious syndrome, decreases the period of eruptions and the duration of local inflammations, and accelerates the epithelialization of erosions.

Characterizing the risk of infection from Mycobacterium tuberculosis in commercial passenger aircraft using quantitative microbial risk assessment.

PubMed

Jones, Rachael M; Masago, Yoshifumi; Bartrand, Timothy; Haas, Charles N; Nicas, Mark; Rose, Joan B

2009-03-01

Quantitative microbial risk assessment was used to predict the likelihood and spatial organization of Mycobacterium tuberculosis (Mtb) transmission in a commercial aircraft. Passenger exposure was predicted via a multizone Markov model in four scenarios: seated or moving infectious passengers and with or without filtration of recirculated cabin air. The traditional exponential (k = 1) and a new exponential (k = 0.0218) dose-response function were used to compute infection risk. Emission variability was included by Monte Carlo simulation. Infection risks were higher nearer and aft of the source; steady state airborne concentration levels were not attained. Expected incidence was low to moderate, with the central 95% ranging from 10(-6) to 10(-1) per 169 passengers in the four scenarios. Emission rates used were low compared to measurements from active TB patients in wards, thus a "superspreader" emitting 44 quanta/h could produce 6.2 cases or more under these scenarios. Use of respiratory protection by the infectious source and/or susceptible passengers reduced infection incidence up to one order of magnitude.

EXPERIMENTAL CHALLENGE STUDY OF FV3-LIKE RANAVIRUS INFECTION IN PREVIOUSLY FV3-LIKE RANAVIRUS INFECTED EASTERN BOX TURTLES (TERRAPENE CAROLINA CAROLINA) TO ASSESS INFECTION AND SURVIVAL.

PubMed

Hausmann, Jennifer C; Wack, Allison N; Allender, Matthew C; Cranfield, Mike R; Murphy, Kevin J; Barrett, Kevin; Romero, Jennell L; Wellehan, James F X; Blum, Stella A; Zink, M Christine; Bronson, Ellen

2015-12-01

The Maryland Zoo in Baltimore experienced an outbreak of Frog virus-3 (FV3)-like ranavirus during the summer of 2011, during which 14 of 27 (52%) of its captive eastern box turtles (Terrapene carolina carolina) survived. To assess survival, immunity, and viral shedding, an experimental challenge study was performed in which the surviving, previously infected turtles were reinfected with the outbreak strain of FV3-like ranavirus. Seven turtles were inoculated with virus intramuscularly and four control turtles received saline intramuscularly. The turtles were monitored for 8 wk with blood and oral swabs collected for quantitative polymerase chain reaction (qPCR). During that time, one of seven (14%) inoculated turtles and none of the controls (0%) died; there was no significant difference in survival. Clinical signs of the inoculated turtles, except for the turtle that died, were mild compared to the original outbreak. Quantitative PCR for FV3-like ranavirus on blood and oral swabs was positive for all inoculated turtles and negative for all controls. The turtle that died had intracytoplasmic inclusion bodies in multiple organs. Three inoculated and two control turtles were euthanized at the end of the study. No inclusion bodies were present in any of the organs. Quantitative PCR detected FV3-like ranavirus in the spleen of a control turtle, which suggested persistence of the virus. The surviving five turtles were qPCR-negative for FV3-like ranavirus from blood and oral swabs after brumation. Quantitative PCR for Terrapene herpesvirus 1 found no association between ranavirus infection and herpesvirus loads. In conclusion, previously infected eastern box turtles can be reinfected with the same strain of FV3-like ranavirus and show mild to no clinical signs but can shed the virus from the oral cavity.

Assessing the impact of a cattle risk-based trading scheme on the movement of bovine tuberculosis infected animals in England and Wales.

PubMed

Adkin, A; Brouwer, A; Downs, S H; Kelly, L

2016-01-01

The adoption of bovine tuberculosis (bTB) risk-based trading (RBT) schemes has the potential to reduce the risk of bTB spread. However, any scheme will have cost implications that need to be balanced against its likely success in reducing bTB. This paper describes the first stochastic quantitative model assessing the impact of the implementation of a cattle risk-based trading scheme to inform policy makers and contribute to cost-benefit analyses. A risk assessment for England and Wales was developed to estimate the number of infected cattle traded using historic movement data recorded between July 2010 and June 2011. Three scenarios were implemented: cattle traded with no RBT scheme in place, voluntary provision of the score and a compulsory, statutory scheme applying a bTB risk score to each farm. For each scenario, changes in trade were estimated due to provision of the risk score to potential purchasers. An estimated mean of 3981 bTB infected animals were sold to purchasers with no RBT scheme in place in one year, with 90% confidence the true value was between 2775 and 5288. This result is dependent on the estimated between herd prevalence used in the risk assessment which is uncertain. With the voluntary provision of the risk score by farmers, on average, 17% of movements was affected (purchaser did not wish to buy once the risk score was available), with a reduction of 23% in infected animals being purchased initially. The compulsory provision of the risk score in a statutory scheme resulted in an estimated mean change to 26% of movements, with a reduction of 37% in infected animals being purchased initially, increasing to a 53% reduction in infected movements from higher risk sellers (score 4 and 5). The estimated mean reduction in infected animals being purchased could be improved to 45% given a 10% reduction in risky purchase behaviour by farmers which may be achieved through education programmes, or to an estimated mean of 49% if a rule was implemented

Are scabies and impetigo "normalised"? A cross-sectional comparative study of hospitalised children in northern Australia assessing clinical recognition and treatment of skin infections.

PubMed

Yeoh, Daniel K; Anderson, Aleisha; Cleland, Gavin; Bowen, Asha C

2017-07-01

Complications of scabies and impetigo such as glomerulonephritis and invasive bacterial infection in Australian Aboriginal children remain significant problems and the overall global burden of disease attributable to these skin infections remains high despite the availability of effective treatment. We hypothesised that one factor contributing to this high burden is that skin infection is under-recognised and hence under-treated, in settings where prevalence is high. We conducted a prospective, cross-sectional study to assess the burden of scabies, impetigo, tinea and pediculosis in children admitted to two regional Australian hospitals from October 2015 to January 2016. A retrospective chart review of patients admitted in November 2014 (mid-point of the prospective data collection in the preceding year) was performed. Prevalence of documented skin infection was compared in the prospective and retrospective population to assess clinician recognition and treatment of skin infections. 158 patients with median age 3.6 years, 74% Aboriginal, were prospectively recruited. 77 patient records were retrospectively reviewed. Scabies (8.2% vs 0.0%, OR N/A, p = 0.006) and impetigo (49.4% vs 19.5%, OR 4.0 (95% confidence interval [CI 2.1-7.7) were more prevalent in the prospective analysis. Skin examination was only documented in 45.5% of cases in the retrospective review. Patients in the prospective analysis were more likely to be prescribed specific treatment for skin infection compared with those in the retrospective review (31.6% vs 5.2%, OR 8.5 (95% CI 2.9-24.4). Scabies and impetigo infections are under-recognised and hence under-treated by clinicians. Improving the recognition and treatment of skin infections by clinicians is a priority to reduce the high burden of skin infection and subsequent sequelae in paediatric populations where scabies and impetigo are endemic.

The kinetics of feline leukaemia virus shedding in experimentally infected cats are associated with infection outcome.

PubMed

Cattori, Valentino; Tandon, Ravi; Riond, Barbara; Pepin, Andrea C; Lutz, Hans; Hofmann-Lehmann, Regina

2009-01-13

Feline leukaemia virus (FeLV) infection in felids results mainly from oronasal exposure to infectious saliva and nasal secretions, but the potential for viral transmission through faeces and urine has not been completely characterized. In order to assess and compare potential FeLV transmission routes, we determined the viral kinetics in plasma, saliva, faeces and urine during early experimental FeLV infection (up to week 15 post-exposure) in specific pathogen-free cats. In addition to monitoring p27 antigen levels measured by ELISA, we evaluated the presence of infectious particles by cell culture assays and quantified viral RNA loads by a quantitative real-time TaqMan polymerase chain reaction. RNA load was associated with infection outcome (high load-progressive infection; low load-regressive infection) not only in plasma, but also in saliva, faeces and urine. Infectious virus was isolated from the saliva, faeces and urine of infected cats with progressive infection as early as 3-6 weeks post-infection, but usually not in cats with regressive infection. In cats with progressive infection, therefore, not only saliva but also faeces and to some extent urine might represent potential FeLV transmission routes. These results should be taken into account when modelling FeLV-host interactions and assessing FeLV transmission risk. Moreover, during early FeLV infection, detection of viral RNA in saliva may be used as an indicator of recent virus exposure, even in cats without detectable antigenaemia/viraemia. To determine the clinically relevant outcome of FeLV infection in exposed cats, however, p27 antigen levels in the peripheral blood should be measured.

The paratransgenic sand fly: a platform for control of Leishmania transmission.

PubMed

Hurwitz, Ivy; Hillesland, Heidi; Fieck, Annabeth; Das, Pradeep; Durvasula, Ravi

2011-05-19

to L. donovani infection.

Clinico-Epidemiological Patterns of Cutaneous Leishmaniasis Patients Attending the Anuradhapura Teaching Hospital, Sri Lanka.

PubMed

Galgamuwa, Lahiru Sandaruwan; Sumanasena, Buthsiri; Yatawara, Lalani; Wickramasinghe, Susiji; Iddawela, Devika

2017-02-01

Cutaneous leishmaniasis (CL) caused by Leishmania donovani is an endemic vector-borne disease in Sri Lanka. Over 2,500 cases have been reported since 2000 and the number of CL cases has dramatically increased annually. Total 57 clinically suspected CL patients attending the dermatology clinic in Anuradhapura Teaching Hospital were recruited from January to June 2015. Slit skin smears and skin biopsies were taken from each of the subjects. Clinical and epidemiological data were obtained using interviewer administered questionnaire. Forty-three (75.4%) patients among 57 were confirmed positive for L. donovani . The majority of infected patients was males ( P =0.005), and the most affected age group was 21-40 years. Soldiers in security forces, farmers, and housewives were identified as high risk groups. The presence of scrub jungles around the residence or places of occupation ( P =0.003), the presence of sandflies ( P =0.021), and working outsides more than 6 hr per day ( P =0.001) were significantly associated with CL. The number of lesions ranged from 1-3, and the majority (76%) of the patients had a single lesion. Upper and lower extremities were the prominent places of lesions, while the wet type of lesions were more prevalent in females ( P =0.022). A nodular-ulcerative type lesion was common in both sexes. The presence of sandflies, scrub jungles, and outdoor activities contributed to spread of Leishmania parasites in an endemic pattern. Implementation of vector control programs together with health education with regard to transmission and prevention of CL are necessary to control the spread of this infection.

Prevalence and Predictors of Intestinal Helminth Infections Among Human Immunodeficiency Virus Type 1–Infected Adults in an Urban African Setting

PubMed Central

Modjarrad, Kayvon; Zulu, Isaac; Redden, David T.; Njobvu, Lungowe; Freedman, David O.; Vermund, Sten H.

2009-01-01

Sub-Saharan Africa is disproportionately burdened by intestinal helminth and human immunodeficiency virus (HIV)-1 infection. Recent evidence suggests detrimental immunologic effects from concomitant infection with the two pathogens. Few studies, however, have assessed the prevalence of and predictors for intestinal helminth infection among HIV-1–infected adults in urban African settings where HIV infection rates are highest. We collected and analyzed sociodemographic and parasitologic data from 297 HIV-1–infected adults (mean age = 31.1 years, 69% female) living in Lusaka, Zambia to assess the prevalence and associated predictors of helminth infection. We found at least one type of intestinal helminth in 24.9% of HIV-infected adults. Thirty-nine (52.7%) were infected with Ascaris lumbricoides, and 29 (39.2%) were infected with hookworm. More than 80% were light-intensity infections. A recent visit to a rural area, food shortage, and prior history of helminth infection were significant predictors of current helminth status. The high helminth prevalence and potential for adverse interactions between helminths and HIV suggests that helminth diagnosis and treatment should be part of routine HIV care. PMID:16222025

Factors Associated with Acquisition of Human Infective and Animal Infective Trypanosome Infections in Domestic Livestock in Western Kenya

PubMed Central

von Wissmann, Beatrix; Machila, Noreen; Picozzi, Kim; Fèvre, Eric M.; deC. Bronsvoort, Barend M.; Handel, Ian G.; Welburn, Susan C.

2011-01-01

Background Trypanosomiasis is regarded as a constraint on livestock production in Western Kenya where the responsibility for tsetse and trypanosomiasis control has increasingly shifted from the state to the individual livestock owner. To assess the sustainability of these localised control efforts, this study investigates biological and management risk factors associated with trypanosome infections detected by polymerase chain reaction (PCR), in a range of domestic livestock at the local scale in Busia, Kenya. Busia District also remains endemic for human sleeping sickness with sporadic cases of sleeping sickness reported. Results In total, trypanosome infections were detected in 11.9% (329) out of the 2773 livestock sampled in Busia District. Multivariable logistic regression revealed that host species and cattle age affected overall trypanosome infection, with significantly increased odds of infection for cattle older than 18 months, and significantly lower odds of infection in pigs and small ruminants. Different grazing and watering management practices did not affect the odds of trypanosome infection, adjusted by host species. Neither anaemia nor condition score significantly affected the odds of trypanosome infection in cattle. Human infective Trypanosoma brucei rhodesiense were detected in 21.5% of animals infected with T. brucei s.l. (29/135) amounting to 1% (29/2773) of all sampled livestock, with significantly higher odds of T. brucei rhodesiense infections in T. brucei s.l. infected pigs (OR = 4.3, 95%CI 1.5-12.0) than in T. brucei s.l. infected cattle or small ruminants. Conclusions Although cattle are the dominant reservoir of trypanosome infection it is unlikely that targeted treatment of only visibly diseased cattle will achieve sustainable interruption of transmission for either animal infective or zoonotic human infective trypanosomiasis, since most infections were detected in cattle that did not exhibit classical clinical signs of

In Vitro Evaluation of a Soluble Leishmania Promastigote Surface Antigen as a Potential Vaccine Candidate against Human Leishmaniasis

PubMed Central

Bahi-Jaber, Narges; Petitdidier, Elodie; Markikou-Ouni, Wafa; Aoun, Karim; Moreno, Javier; Carrillo, Eugenia; Salotra, Poonam; Kaushal, Himanshu; Negi, Narender Singh; Arevalo, Jorge; Falconi-Agapito, Francesca; Privat, Angela; Cruz, Maria; Pagniez, Julie; Papierok, Gérard-Marie; Rhouma, Faten Bel Haj; Torres, Pilar; Lemesre, Jean-Loup; Chenik, Mehdi; Meddeb-Garnaoui, Amel

2014-01-01

PSA (Promastigote Surface Antigen) belongs to a family of membrane-bound and secreted proteins present in several Leishmania (L.) species. PSA is recognized by human Th1 cells and provides a high degree of protection in vaccinated mice. We evaluated humoral and cellular immune responses induced by a L. amazonensis PSA protein (LaPSA-38S) produced in a L. tarentolae expression system. This was done in individuals cured of cutaneous leishmaniasis due to L. major (CCLm) or L. braziliensis (CCLb) or visceral leishmaniasis due to L. donovani (CVLd) and in healthy individuals. Healthy individuals were subdivided into immune (HHR-Lm and HHR-Li: Healthy High Responders living in an endemic area for L. major or L. infantum infection) or non immune/naive individuals (HLR: Healthy Low Responders), depending on whether they produce high or low levels of IFN-γ in response to Leishmania soluble antigen. Low levels of total IgG antibodies to LaPSA-38S were detected in sera from the studied groups. Interestingly, LaPSA-38S induced specific and significant levels of IFN-γ, granzyme B and IL-10 in CCLm, HHR-Lm and HHR-Li groups, with HHR-Li group producing TNF-α in more. No significant cytokine response was observed in individuals immune to L. braziliensis or L. donovani infection. Phenotypic analysis showed a significant increase in CD4+ T cells producing IFN-γ after LaPSA-38S stimulation, in CCLm. A high positive correlation was observed between the percentage of IFN-γ-producing CD4+ T cells and the released IFN-γ. We showed that the LaPSA-38S protein was able to induce a mixed Th1 and Th2/Treg cytokine response in individuals with immunity to L. major or L. infantum infection indicating that it may be exploited as a vaccine candidate. We also showed, to our knowledge for the first time, the capacity of Leishmania PSA protein to induce granzyme B production in humans with immunity to L. major and L. infantum infection. PMID:24786587

The relationship between infecting dose and severity of disease in reported outbreaks of Salmonella infections.

PubMed Central

Glynn, J. R.; Bradley, D. J.

1992-01-01

The relationship between size of the infecting dose and severity of the resulting disease has been investigated for salmonella infections by reanalysis of data within epidemics for 32 outbreaks, and comparing data between outbreaks for 68 typhoid epidemics and 49 food-poisoning outbreaks due to salmonellas. Attack rate, incubation period, amount of infected food consumed and type of vehicle are used as proxy measures of infecting dose, while case fatality rates for typhoid and case hospitalization rates for food poisoning salmonellas were used to assess severity. Limitations of the data are discussed. Both unweighted and logit analysis models are used. There is no evidence for a dose-severity relationship for Salmonella typhi, but evidence of a correlation between dose and severity is available from within-epidemic or between-epidemic analysis, or both, for Salmonella typhimurium, S. enteritidis, S. infantis, S. newport, and S. thompson. The presence of such a relationship affects the way in which control interventions should be assessed. PMID:1468522

A prospective assessment of pelvic infection risk following same-day sexually transmitted infection testing and levonorgestrel intrauterine system placement.

PubMed

Turok, David K; Eisenberg, David L; Teal, Stephanie B; Keder, Lisa M; Creinin, Mitchell D

2016-11-01

Misperceptions persist that intrauterine device placement is related to pelvic infections and Chlamydia and gonorrhea testing results are needed prior to placement. We sought to evaluate the relationship of Chlamydia and gonorrhea screening to pelvic infection for up to 2 years following placement of the levonorgestrel 52-mg intrauterine system. A total of 1751 nulliparous and multiparous females 16 to 45 years old enrolled in a multicenter trial designed to evaluate the efficacy and safety of a new levonorgestrel intrauterine system for up to 7 years. Participants had Chlamydia screening at study entry and yearly if they were age ≤25 years. Women also had baseline gonorrhea screening if testing had not been performed since starting their current sexual relationship. Those who changed sexual partners during the trial had repeated Chlamydia and gonorrhea testing. Intrauterine system insertion could occur on the same day as screening. Participants did not receive prophylactic antibiotics for intrauterine system placement. Investigators performed pelvic examinations after 12 and 24 months and when clinically indicated during visits at 3, 6, and 18 months after placement and unscheduled visits. Pelvic infection included any clinical diagnosis of pelvic inflammatory disease or endometritis. Most participants (n = 1364, 79.6%) did not have sexually transmitted infection test results available prior to intrauterine system placement. In all, 29 (1.7%) participants had positive baseline testing for a sexually transmitted infection (Chlamydia, n = 25; gonorrhea, n = 3; both, n = 1); 6 of these participants had known results (all with Chlamydia infection) prior to intrauterine system placement and received treatment before enrollment. The 23 participants whose results were not known at the time of intrauterine system placement received treatment without intrauterine system removal and none developed pelvic infection. The incidence of positive Chlamydia testing was

Are scabies and impetigo “normalised”? A cross-sectional comparative study of hospitalised children in northern Australia assessing clinical recognition and treatment of skin infections

PubMed Central

Anderson, Aleisha; Cleland, Gavin; Bowen, Asha C.

2017-01-01

Background Complications of scabies and impetigo such as glomerulonephritis and invasive bacterial infection in Australian Aboriginal children remain significant problems and the overall global burden of disease attributable to these skin infections remains high despite the availability of effective treatment. We hypothesised that one factor contributing to this high burden is that skin infection is under-recognised and hence under-treated, in settings where prevalence is high. Methods We conducted a prospective, cross-sectional study to assess the burden of scabies, impetigo, tinea and pediculosis in children admitted to two regional Australian hospitals from October 2015 to January 2016. A retrospective chart review of patients admitted in November 2014 (mid-point of the prospective data collection in the preceding year) was performed. Prevalence of documented skin infection was compared in the prospective and retrospective population to assess clinician recognition and treatment of skin infections. Results 158 patients with median age 3.6 years, 74% Aboriginal, were prospectively recruited. 77 patient records were retrospectively reviewed. Scabies (8.2% vs 0.0%, OR N/A, p = 0.006) and impetigo (49.4% vs 19.5%, OR 4.0 (95% confidence interval [CI 2.1–7.7) were more prevalent in the prospective analysis. Skin examination was only documented in 45.5% of cases in the retrospective review. Patients in the prospective analysis were more likely to be prescribed specific treatment for skin infection compared with those in the retrospective review (31.6% vs 5.2%, OR 8.5 (95% CI 2.9–24.4). Conclusions Scabies and impetigo infections are under-recognised and hence under-treated by clinicians. Improving the recognition and treatment of skin infections by clinicians is a priority to reduce the high burden of skin infection and subsequent sequelae in paediatric populations where scabies and impetigo are endemic. PMID:28671945

Assessing the infection risk of Giardia and Cryptosporidium in public drinking water delivered by surface water systems in Sao Paulo State, Brazil.

PubMed

Sato, Maria Ines Z; Galvani, Ana Tereza; Padula, Jose Antonio; Nardocci, Adelaide Cassia; Lauretto, Marcelo de Souza; Razzolini, Maria Tereza Pepe; Hachich, Elayse Maria

2013-01-01

A survey of Giardia and Cryptosporidium was conducted in surface water used as drinking water sources by public water systems in four densely urbanized regions of Sao Paulo State, Brazil. A Quantitative Microbial Risk Assessment, based on protozoa concentrations, was performed to estimate the probability of protozoa infection associated with drinking water ingestion. A total of 206 source water samples were analyzed over a 24 month period using the USEPA Method 1623. The risk of infection was estimated using an exponential dose response model, children and adults exposure and a gamma distribution for (oo)cyst concentrations with three scenarios for treating censored data. Giardia was detected in 102 of the samples, and 19 of them were also positive for Cryptosporidium, with maximum concentrations of 97.0 cysts/L and 6.0 oocysts/L, respectively. Risk distributions were similar for the three scenarios. In the four regions, the estimated risk of Giardia infection per year, for adults and children, ranged from 0.29% to 2.47% and from 0.08% to 0.70%, respectively. Cryptosporidium risk infection varied from 0.15% to 0.29% for adults and from 0.04% to 0.08% for children. In both cases, the calculated risk surpassed the risk of infection of 10(-4) (1:10,000) defined as tolerable by USEPA for a yearly exposure. The probability of Giardia infection was very close to the rates of acute diarrheic disease for adults (1% to 3%) but lower for children (2% to 7%). The daily consumption of drinking water was an important contributing factor for these differences. The Microbiological Risk Assessment carried out in this study provides an indication of infection risks by Giardia and Cryptosporidium in the population served by these source waters. Strategies for source water protection and performance targets for the water treatment should be established to achieve the required level of public health risk. Copyright © 2012 Elsevier B.V. All rights reserved.

The assessment of risk factors for the Central/East African Genotype of chikungunya virus infections in the state of Kelantan: a case control study in Malaysia.

PubMed

Yusoff, Ahmad Faudzi; Mustafa, Amal Nasir; Husaain, Hani Mat; Hamzah, Wan Mansor; Yusof, Apandi Mohd; Harun, Rozilawati; Abdullah, Faezah Noor

2013-05-08

The aims of the study were to assess the risk factors in relation to cross border activities, exposure to mosquito bite and preventive measures taken.An outbreak of chikungunya virus (CHIKV) infection in Malaysia has been reported in Klang, Selangor (1998) and Bagan Panchor, Perak (2006). In 2009, CHIKV infection re-emerged in some states in Malaysia. It raises the possibilities that re-emergence is part of the epidemics in neighbouring countries or the disease is endemic in Malaysia. For this reason, A community-based case control study was carried out in the state of Kelantan. Prospective case finding was performed from June to December 2009. Those who presented with signs and symptoms of CHIKV infection were investigated. We designed a case control study to assess the risk factors. Assessment consisted of answering questions, undergoing a medical examination, and being tested for the presence of IgM antibodies to CHIKV. Descriptive epidemiological studies were conducted by reviewing both the national surveillance and laboratory data. Multivariable logistic regression analysis was performed to determine risk factors contributing to the illness. Cases were determined by positive to RT-PCR or serological for antibodies by IgM. CHIKV specificity was confirmed by DNA sequencing. There were 129 suspected cases and 176 controls. Among suspected cases, 54.4% were diagnosed to have CHIKV infection. Among the controls, 30.1% were found to be positive to serology for antibodies [IgM, 14.2% and IgG, 15.9%]. For analytic study and based on laboratory case definition, 95 were considered as cases and 123 as controls. Those who were positive to IgG were excluded. CHIKV infection affected all ages and mostly between 50-59 years old. Staying together in the same house with infected patients and working as rubber tappers were at a higher risk of infection. The usage of Mosquito coil insecticide had shown to be a significant protective factor. Most cases were treated as outpatient

The assessment of risk factors for the Central/East African Genotype of chikungunya virus infections in the state of Kelantan: a case control study in Malaysia

PubMed Central

2013-01-01

Background The aims of the study were to assess the risk factors in relation to cross border activities, exposure to mosquito bite and preventive measures taken. An outbreak of chikungunya virus (CHIKV) infection in Malaysia has been reported in Klang, Selangor (1998) and Bagan Panchor, Perak (2006). In 2009, CHIKV infection re-emerged in some states in Malaysia. It raises the possibilities that re-emergence is part of the epidemics in neighbouring countries or the disease is endemic in Malaysia. For this reason, A community-based case control study was carried out in the state of Kelantan. Methods Prospective case finding was performed from June to December 2009. Those who presented with signs and symptoms of CHIKV infection were investigated. We designed a case control study to assess the risk factors. Assessment consisted of answering questions, undergoing a medical examination, and being tested for the presence of IgM antibodies to CHIKV. Descriptive epidemiological studies were conducted by reviewing both the national surveillance and laboratory data. Multivariable logistic regression analysis was performed to determine risk factors contributing to the illness. Cases were determined by positive to RT-PCR or serological for antibodies by IgM. CHIKV specificity was confirmed by DNA sequencing. Results There were 129 suspected cases and 176 controls. Among suspected cases, 54.4% were diagnosed to have CHIKV infection. Among the controls, 30.1% were found to be positive to serology for antibodies [IgM, 14.2% and IgG, 15.9%]. For analytic study and based on laboratory case definition, 95 were considered as cases and 123 as controls. Those who were positive to IgG were excluded. CHIKV infection affected all ages and mostly between 50–59 years old. Staying together in the same house with infected patients and working as rubber tappers were at a higher risk of infection. The usage of Mosquito coil insecticide had shown to be a significant protective factor. Most

Diagnostic assessment without cut-offs: application of serology for the modelling of bovine digital dermatitis infection.

PubMed

Vink, W D; Jones, G; Johnson, W O; Brown, J; Demirkan, I; Carter, S D; French, N P

2009-11-15

Bovine digital dermatitis (BDD) is an epidermitis which is a leading cause of infectious lameness. The only recognized diagnostic test is foot inspection, which is a labour-intensive procedure. There is no universally recognized, standardized lesion scoring system. As small lesions are easily missed, foot inspection has limited diagnostic sensitivity. Furthermore, interpretation is subjective, and prone to observer bias. Serology is more convenient to carry out and is potentially a more sensitive indicator of infection. By carrying out 20 serological assays using lesion-associated Treponema spp. isolates, three serogroups were identified. The reliability of the tests was established by assessing the level of agreement and the concordance correlation coefficient. Subsequently, an ELISA suitable for routine use was developed. The benchmark of diagnostic test validation is conventionally the determination of the key test parameters, sensitivity and specificity. This requires the imposition of a cut-off point. For serological assays with outcomes on a continuous scale, the degree by which the test result differs from this cut-off is disregarded. Bayesian statistical methodology has been developed which enables the assay result also to be interpreted on a continuous scale, thereby optimizing the information inherent in the test. Using a cross-sectional study dataset carried out on 8 representative dairy farms in the UK, the probability of infection, P(I), of each individual animal was estimated in the absence of a 'Gold Standard' by modelling I as a latent variable which was determined by lesion status, L as well as serology, S. Covariate data (foot hygiene score and age) were utilized to estimate P(L) when no lesion inspection was performed. Informative prior distributions were elicited where possible. The model was utilized for predictive inference, by computing estimates of P(I) and P(L) independently of the data. A more detailed and informative analysis of the farm

CD8+ lymphocytes control viral replication in SIVmac239-infected rhesus macaques without decreasing the lifespan of productively infected cells.

PubMed

Klatt, Nichole R; Shudo, Emi; Ortiz, Alex M; Engram, Jessica C; Paiardini, Mirko; Lawson, Benton; Miller, Michael D; Else, James; Pandrea, Ivona; Estes, Jacob D; Apetrei, Cristian; Schmitz, Joern E; Ribeiro, Ruy M; Perelson, Alan S; Silvestri, Guido

2010-01-29

While CD8+ T cells are clearly important in controlling virus replication during HIV and SIV infections, the mechanisms underlying this antiviral effect remain poorly understood. In this study, we assessed the in vivo effect of CD8+ lymphocyte depletion on the lifespan of productively infected cells during chronic SIVmac239 infection of rhesus macaques. We treated two groups of animals that were either CD8+ lymphocyte-depleted or controls with antiretroviral therapy, and used mathematical modeling to assess the lifespan of infected cells either in the presence or absence of CD8+ lymphocytes. We found that, in both early (day 57 post-SIV) and late (day 177 post-SIV) chronic SIV infection, depletion of CD8+ lymphocytes did not result in a measurable increase in the lifespan of either short- or long-lived productively infected cells in vivo. This result indicates that the presence of CD8+ lymphocytes does not result in a noticeably shorter lifespan of productively SIV-infected cells, and thus that direct cell killing is unlikely to be the main mechanism underlying the antiviral effect of CD8+ T cells in SIV-infected macaques with high virus replication.

CD8+ Lymphocytes Control Viral Replication in SIVmac239-Infected Rhesus Macaques without Decreasing the Lifespan of Productively Infected Cells

PubMed Central

Klatt, Nichole R.; Shudo, Emi; Ortiz, Alex M.; Engram, Jessica C.; Paiardini, Mirko; Lawson, Benton; Miller, Michael D.; Else, James; Pandrea, Ivona; Estes, Jacob D.; Apetrei, Cristian; Schmitz, Joern E.; Ribeiro, Ruy M.; Perelson, Alan S.; Silvestri, Guido

2010-01-01

While CD8+ T cells are clearly important in controlling virus replication during HIV and SIV infections, the mechanisms underlying this antiviral effect remain poorly understood. In this study, we assessed the in vivo effect of CD8+ lymphocyte depletion on the lifespan of productively infected cells during chronic SIVmac239 infection of rhesus macaques. We treated two groups of animals that were either CD8+ lymphocyte-depleted or controls with antiretroviral therapy, and used mathematical modeling to assess the lifespan of infected cells either in the presence or absence of CD8+ lymphocytes. We found that, in both early (day 57 post-SIV) and late (day 177 post-SIV) chronic SIV infection, depletion of CD8+ lymphocytes did not result in a measurable increase in the lifespan of either short- or long-lived productively infected cells in vivo. This result indicates that the presence of CD8+ lymphocytes does not result in a noticeably shorter lifespan of productively SIV-infected cells, and thus that direct cell killing is unlikely to be the main mechanism underlying the antiviral effect of CD8+ T cells in SIV-infected macaques with high virus replication. PMID:20126441

Useful biomarkers for assessment of hepatitis C virus infection-associated autoimmune disorders

PubMed Central

Yang, Deng-Ho; Ho, Ling-Jun; Lai, Jenn-Haung

2014-01-01

During the course of chronic hepatitis C virus (HCV) infection, various extrahepatic manifestations of autoimmune disorders may occur, including arthralgia/arthritis, sicca complex, purpura, cutaneous ulcer, and thyroid dysfunction. In addition, the prevalence of circulating autoantibodies is high among patients with HCV infection. Commonly detected autoantibodies in HCV-infected patients include rheumatoid factor, antinuclear antibody, anti-SSA/anti-SSB antibody, cryoglobulin, antineutrophil cytoplasmic antibody, anti-smooth muscle antibody, anti-liver and anti-thyroid autoantibodies. These autoantibodies may be associated with underlying autoimmune disorders or liver inflammation in HCV infection. A possible reason for antibody production is overactivation and proliferation of B lymphocytes, via the interaction with the surface protein of HCV. Because immunotherapy can cause HCV flare-up or liver damage, overdiagnosis of HCV-related autoimmune symptoms as primary autoimmune disorders should be avoided. This review describes biomarkers that are useful in clinically evaluating autoimmune manifestations and disorders associated with HCV infection. PMID:24659887

African swine fever virus infection in Classical swine fever subclinically infected wild boars.

PubMed

Cabezón, Oscar; Muñoz-González, Sara; Colom-Cadena, Andreu; Pérez-Simó, Marta; Rosell, Rosa; Lavín, Santiago; Marco, Ignasi; Fraile, Lorenzo; de la Riva, Paloma Martínez; Rodríguez, Fernando; Domínguez, Javier; Ganges, Llilianne

2017-08-01

Recently moderate-virulence classical swine fever virus (CSFV) strains have been proven capable of generating postnatal persistent infection (PI), defined by the maintenance of viremia and the inability to generate CSFV-specific immune responses in animals. These animals also showed a type I interferon blockade in the absence of clinical signs. In this study, we assessed the infection generated in 7-week-old CSFV PI wild boars after infection with the African swine fever virus (ASFV). The wild boars were divided in two groups and were infected with ASFV. Group A comprised boars who were CSFV PI in a subclinical form and Group B comprised pestivirus-free wild boars. Some relevant parameters related to CSFV replication and the immune response of CSFV PI animals were studied. Additionally, serum soluble factors such as IFN-α, TNF-α, IL-6, IL-10, IFN-γ and sCD163 were analysed before and after ASFV infection to assess their role in disease progression. After ASFV infection, only the CSFV PI wild boars showed progressive acute haemorrhagic disease; however, the survival rates following ASFV infection was similar in both experimental groups. Notwithstanding, the CSFV RNA load of CSFV PI animals remained unaltered over the study; likewise, the ASFV DNA load detected after infection was similar between groups. Interestingly, systemic type I FN-α and IL-10 levels in sera were almost undetectable in CSFV PI animals, yet detectable in Group B, while detectable levels of IFN-γ were found in both groups. Finally, the flow cytometry analysis showed an increase in myelomonocytic cells (CD172a + ) and a decrease in CD4 + T cells in the PBMCs from CSFV PI animals after ASFV infection. Our results showed that the immune response plays a role in the progression of disease in CSFV subclinically infected wild boars after ASFV infection, and the immune response comprised the systemic type I interferon blockade. ASFV does not produce any interference with CSFV replication, or vice

Assessment of infection control practices in maternity units in Southern Nigeria.

PubMed

Friday, Okonofua; Edoja, Okpokunu; Osasu, Aigbogun; Chinenye, Nwandu; Cyril, Mokwenye; Lovney, Kanguru; Julia, Hussein

2012-12-01

Puerperal sepsis accounts for 12% of maternal deaths in Nigeria. To date, little is known about the background hospital factors that predispose pregnant women to puerperal infection that leads to mortality. The objective of this study was to investigate the nature and pattern of existing policies and practices relating to infection control in maternity care centres in Edo state, South-South Nigeria. Cross-sectional study consisting of in-depth interviews with service providers, observation of clinical practices and examination of medical records. Public and private health-care facilities in eight local government areas (LGAs) selected from the three senatorial districts of Edo State, Nigeria. Health providers from 63 primary, secondary and tertiary maternity care centres. Sixty-three health-care facilities were sampled from eight LGAs from the three senatorial districts in Edo State. Three pre-tested tools were adapted to the local setting and used to interview key informants in the health facilities and to observe for practices and records relating to infection control. Of the 63 health facilities, 68% (43) reported that they had infection control procedures in place, while only 25% (16) reported that they documented these as manuals or charts. Only 13% (8) of facilities had infection control committees; 11% (7) routinely carried out audits of maternal deaths, while 33% (21) reported that they had an ongoing programme for staff training on infection control. A high proportion of the health facilities reported that staff routinely wash their hands before and after sterile procedures, but only half of the facilities were observed to have 24-h running water and only two-thirds had soap and antiseptic solutions in delivery and operating theatre areas. Although more than 90% (57) of the health facilities reported that they use sterile gloves routinely, unused sterile gloves were found in only 60% (38) of these facilities, and recycled gloves in 11.1% (7). The results

Neurological Manifestations of Dengue Infection.

PubMed

Li, Guo-Hong; Ning, Zhi-Jie; Liu, Yi-Ming; Li, Xiao-Hong

2017-01-01

Dengue counts among the most commonly encountered arboviral diseases, representing the fastest spreading tropical illness in the world. It is prevalent in 128 countries, and each year >2.5 billion people are at risk of dengue virus infection worldwide. Neurological signs of dengue infection are increasingly reported. In this review, the main neurological complications of dengue virus infection, such as central nervous system (CNS), peripheral nervous system, and ophthalmic complications were discussed according to clinical features, treatment and possible pathogenesis. In addition, neurological complications in children were assessed due to their atypical clinical features. Finally, dengue infection and Japanese encephalitis were compared for pathogenesis and main clinical manifestations.

Integrated Cryptosporidium Assay To Determine Oocyst Density, Infectivity, and Genotype for Risk Assessment of Source and Reuse Water

PubMed Central

King, Brendon; Fanok, Stella; Phillips, Renae; Swaffer, Brooke

2015-01-01

Cryptosporidium continues to be problematic for the water industry, with risk assessments often indicating that treatment barriers may fail under extreme conditions. However, risk analyses have historically used oocyst densities and not considered either oocyst infectivity or species/genotype, which can result in an overestimation of risk if the oocysts are not human infective. We describe an integrated assay for determining oocyst density, infectivity, and genotype from a single-sample concentrate, an important advance that overcomes the need for processing multiple-grab samples or splitting sample concentrates for separate analyses. The assay incorporates an oocyst recovery control and is compatible with standard primary concentration techniques. Oocysts were purified from primary concentrates using immunomagnetic separation prior to processing by an infectivity assay. Plate-based cell culture was used to detect infectious foci, with a monolayer washing protocol developed to allow recovery and enumeration of oocysts. A simple DNA extraction protocol was developed to allow typing of any wells containing infectious Cryptosporidium. Water samples from a variety of source water and wastewater matrices, including a semirural catchment, wastewater, an aquifer recharge site, and storm water, were analyzed using the assay. Results demonstrate that the assay can reliably determine oocyst densities, infectivity, and genotype from single-grab samples for a variety of water matrices and emphasize the varying nature of Cryptosporidium risk extant throughout source waters and wastewaters. This assay should therefore enable a more comprehensive understanding of Cryptosporidium risk for different water sources, assisting in the selection of appropriate risk mitigation measures. PMID:25769833

Integrated cryptosporidium assay to determine oocyst density, infectivity, and genotype for risk assessment of source and reuse water.

PubMed

King, Brendon; Fanok, Stella; Phillips, Renae; Swaffer, Brooke; Monis, Paul

2015-05-15

Cryptosporidium continues to be problematic for the water industry, with risk assessments often indicating that treatment barriers may fail under extreme conditions. However, risk analyses have historically used oocyst densities and not considered either oocyst infectivity or species/genotype, which can result in an overestimation of risk if the oocysts are not human infective. We describe an integrated assay for determining oocyst density, infectivity, and genotype from a single-sample concentrate, an important advance that overcomes the need for processing multiple-grab samples or splitting sample concentrates for separate analyses. The assay incorporates an oocyst recovery control and is compatible with standard primary concentration techniques. Oocysts were purified from primary concentrates using immunomagnetic separation prior to processing by an infectivity assay. Plate-based cell culture was used to detect infectious foci, with a monolayer washing protocol developed to allow recovery and enumeration of oocysts. A simple DNA extraction protocol was developed to allow typing of any wells containing infectious Cryptosporidium. Water samples from a variety of source water and wastewater matrices, including a semirural catchment, wastewater, an aquifer recharge site, and storm water, were analyzed using the assay. Results demonstrate that the assay can reliably determine oocyst densities, infectivity, and genotype from single-grab samples for a variety of water matrices and emphasize the varying nature of Cryptosporidium risk extant throughout source waters and wastewaters. This assay should therefore enable a more comprehensive understanding of Cryptosporidium risk for different water sources, assisting in the selection of appropriate risk mitigation measures. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Infections do not predict shedding in co-infections with two helminths from a natural system.

PubMed

Cattadori, Isabella M; Wagner, Benjamin R; Wodzinski, Laura A; Pathak, Ashutosh K; Poole, Adam

2014-06-01

Given the health and economic burden associated with the widespread occurrence of co-infections in humans and agricultural animals, understanding how coinfections contribute to host heterogeneity to infection and transmission is critical if we are to assess risk of infection based on host characteristics. Here, we examine whether host heterogeneity to infection leads to similar heterogeneity in transmission in a population of rabbits single and co-infected with two helminths and monitored monthly for eight years. Compared to single infections, co-infected rabbits carried higher Trichostrongylus retortaeformis intensities, shorter worms with fewer eggs in utero, and shed similar numbers of parasite eggs. In contrast, the same co-infected rabbits harbored fewer Graphidium strigosum with longer bodies and more eggs in utero, and shed more eggs of this helminth. A positive density-dependent relationship between fecundity and intensity was found for T. retortaeformis but not G. strigosum in co-infected rabbits. Juvenile rabbits contributed to most of the infection and shedding of T. retortaeformis, while adult hosts were more important for G. strigosum dynamics of infection and transmission, and this pattern was consistent in single and co-infected individuals. This host-parasite system suggests that we cannot predict the pattern of parasite shedding during co-infections based on intensity of infection alone. We suggest that a mismatching between susceptibility and infectiousness should be expected in helminth coinfections and should not be overlooked.

Polymerase chain reaction and DNA probe hybridization to assess the efficacy of diminazene treatment in Trypanosoma brucei-infected cattle.

PubMed

Clausen, P H; Waiswa, C; Katunguka-Rwakishaya, E; Schares, G; Steuber, S; Mehlitz, D

1999-03-01

Four of eight Ankole longhorn cattle experimentally infected with Trypanosoma brucei were treated with 7 mg/kg diminazene aceturate (Berenil, Hoechst AG, Germany) at day 71 postinfection. The trypanocidal activity was monitored using polymerase chain reaction (PCR) and DNA probe hybridization. When extracted parasite DNA (without host DNA) was used, as little as 1 fg per reaction, which is equivalent to about 1-10% of the DNA in a single trypanosome, produced a specific product that was visible as a 177-bp band in an agarose gel. In infected cattle, specific PCR products could be amplified at as early as 1 day postinfection. PCR signals remained positive during infection, except in one sample, although aparasitemic phases occurred. In cases where treatment resulted in a significant clinical improvement, PCR signals disappeared at 3-4 days after the administration of the drug. By contrast, in cattle that showed clinical signs of CNS involvement after treatment, although aparasitemic, and died before the termination of the experiment, specific products could be amplified on several occasions following treatment. The PCR signals generated after treatment could be further enhanced by subsequent slot-blot hybridization with a T. brucei-specific DNA probe. We conclude that PCR coupled with DNA probe hybridization provides a highly sensitive tool for the assessment of therapeutic efficiency and disease progression in trypanosome infections, especially in chronic infections when the level of parasitemia is low or when trypanosomes are sequestered at cryptic sites.

Validity of ICD-9-CM Coding for Identifying Incident Methicillin-Resistant Staphylococcus aureus (MRSA) Infections: Is MRSA Infection Coded as a Chronic Disease?

PubMed Central

Schweizer, Marin L.; Eber, Michael R.; Laxminarayan, Ramanan; Furuno, Jon P.; Popovich, Kyle J.; Hota, Bala; Rubin, Michael A.; Perencevich, Eli N.

2013-01-01

BACKGROUND AND OBJECTIVE Investigators and medical decision makers frequently rely on administrative databases to assess methicillin-resistant Staphylococcus aureus (MRSA) infection rates and outcomes. The validity of this approach remains unclear. We sought to assess the validity of the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) code for infection with drug-resistant microorganisms (V09) for identifying culture-proven MRSA infection. DESIGN Retrospective cohort study. METHODS All adults admitted to 3 geographically distinct hospitals between January 1, 2001, and December 31, 2007, were assessed for presence of incident MRSA infection, defined as an MRSA-positive clinical culture obtained during the index hospitalization, and presence of the V09 ICD-9-CM code. The k statistic was calculated to measure the agreement between presence of MRSA infection and assignment of the V09 code. Sensitivities, specificities, positive predictive values, and negative predictive values were calculated. RESULTS There were 466,819 patients discharged during the study period. Of the 4,506 discharged patients (1.0%) who had the V09 code assigned, 31% had an incident MRSA infection, 20% had prior history of MRSA colonization or infection but did not have an incident MRSA infection, and 49% had no record of MRSA infection during the index hospitalization or the previous hospitalization. The V09 code identified MRSA infection with a sensitivity of 24% (range, 21%–34%) and positive predictive value of 31% (range, 22%–53%). The agreement between assignment of the V09 code and presence of MRSA infection had a κ coefficient of 0.26 (95% confidence interval, 0.25–0.27). CONCLUSIONS In its current state, the ICD-9-CM code V09 is not an accurate predictor of MRSA infection and should not be used to measure rates of MRSA infection. PMID:21460469

Development of a LAMP assay for detection of Leishmania infantum infection in dogs using conjunctival swab samples.

PubMed

Gao, Chun-hua; Ding, Dan; Wang, Jun-yun; Steverding, Dietmar; Wang, Xia; Yang, Yue-tao; Shi, Feng

2015-07-15

Leishmania infantum infections in dogs play a crucial role in the transmission of pathogens causing visceral leishmaniasis to humans in the Gansu province, northwest China. To be able to control zoonotic transmission of the parasite to humans, a non-invasive loop-mediated isothermal amplification (LAMP) assay to specifically detect L. infantum infections in dogs was developed. The primers used in the LAMP assay were designed to target kinetoplast DNA minicircle sequences of the L. infantum isolate MCAN/CN/90/SC and tested using DNA isolated from promastigotes of different Leishmania species. The LAMP assay was evaluated with conjunctional swab samples obtained from 111 and 33 dogs living in an endemic and a non-endemic region of zoonotic visceral leishmaniasis in the Gansu province, respectively. The LAMP assay was also compared with conventional PCR, ELISA and microscopy using conjunctional swab, serum and bone marrow samples from the dogs, respectively. The LAMP assay detected 1 fg of L. infantum DNA purified from cultured promastigotes which was 10-fold more sensitive than a conventional PCR test using Leishmania genus-specific primers. No cross reaction was observed with DNA isolated from promastigotes of L. donovani, L. major, L. tropica, and L. braziliensis, and the L. infantum reference strain MHOM/TN/80/IPT1. The L. infantum-positive rates obtained for field-collected samples were 61.3%, 58.6%, 40.5% and 10.8% by LAMP, PCR, ELISA and microscopy, respectively. As only one out of the 33 samples from control dogs from the non-endemic region of zoonotic visceral leishmaniasis was positive by the LAMP assay and the PCR test, the observed true negative rate (specificity) was 97% for both methods. This study has shown that the non-invasive, conjunctional swab-based LAMP assay developed was more sensitive in the detection of leishmaniasis in dogs than PCR, ELISA and microscopy. The findings indicate that the LAMP assay is a sensitive and specific method for the

Portable Ultraviolet Light Surface-Disinfecting Devices for Prevention of Hospital-Acquired Infections: A Health Technology Assessment.

PubMed

2018-01-01

Hospital-acquired infections (HAIs) are infections that patients contract while in the hospital that were neither present nor developing at the time of admission. In Canada an estimated 10% of adults with short-term hospitalization have HAIs. According to 2003 Canadian data, between 4% and 6% of these patients die from these infections. The most common HAIs in Ontario are caused by Clostridium difficile . The standard method of reducing and preventing these infections is decontamination of patient rooms through manual cleaning and disinfection. Several portable no-touch ultraviolet (UV) light systems have been proposed to supplement current hospital cleaning and disinfecting practices. We searched for studies published from inception of UV disinfection technology to January 23, 2017. We compared portable UV surface-disinfecting devices used together with standard hospital room cleaning and disinfecting versus standard hospital cleaning and disinfecting alone. The primary outcome was HAI from C. difficile . Other outcomes were combined HAIs, colonization (i.e., carrying an infectious agent without exhibiting disease symptoms), and the HAI-associated mortality rate. We used Grading of Recommendations Assessment, Development, and Evaluation (GRADE) to rate the quality of evidence of included studies. We also performed a 5-year budget impact analysis from the hospital's perspective. This assessment was limited to portable devices and did not examine wall mounted devices, which are used in some hospitals. The database search for the clinical review yielded 10 peer-reviewed publications that met eligibility criteria. Three studies focused on mercury UV-C-based technology, seven on pulsed xenon UV technology. Findings were either inconsistent or produced very low-quality evidence using the GRADE rating system. The intervention was effective in reducing the rate of the composite outcome of HAIs (combined) and colonization (but quality of evidence was low). For the review

Infection prevention and control.

PubMed

Pegram, Anne; Bloomfield, Jacqueline

2015-03-18

All newly registered graduate nurses are required to have the appropriate knowledge and understanding to perform the skills required for patient care, specifically the competencies identified in the Nursing and Midwifery Council's essential skills clusters. This article focuses on the third essential skills cluster - infection prevention and control. It provides an overview and discussion of the key skills and behaviours that must be demonstrated to meet the standards set by the Nursing and Midwifery Council. In doing so, it considers the key principles of infection prevention and control, including local and national policies, standard infection control precautions, risk assessment, standard isolation measures and asepsis.

Targeted Assessment for Prevention of Healthcare-Associated Infections: A New Prioritization Metric.

PubMed

Soe, Minn M; Gould, Carolyn V; Pollock, Daniel; Edwards, Jonathan

2015-12-01

To develop a method for calculating the number of healthcare-associated infections (HAIs) that must be prevented to reach a HAI reduction goal and identifying and prioritizing healthcare facilities where the largest reductions can be achieved. Acute care hospitals that report HAI data to the Centers for Disease Control and Prevention's National Healthcare Safety Network. METHODS :The cumulative attributable difference (CAD) is calculated by subtracting a numerical prevention target from an observed number of HAIs. The prevention target is the product of the predicted number of HAIs and a standardized infection ratio goal, which represents a HAI reduction goal. The CAD is a numeric value that if positive is the number of infections to prevent to reach the HAI reduction goal. We calculated the CAD for catheter-associated urinary tract infections for each of the 3,639 hospitals that reported such data to National Healthcare Safety Network in 2013 and ranked the hospitals by their CAD values in descending order. Of 1,578 hospitals with positive CAD values, preventing 10,040 catheter-associated urinary tract infections at 293 hospitals (19%) with the highest CAD would enable achievement of the national 25% catheter-associated urinary tract infection reduction goal. The CAD is a new metric that facilitates ranking of facilities, and locations within facilities, to prioritize HAI prevention efforts where the greatest impact can be achieved toward a HAI reduction goal.

Hospitalization for community-acquired febrile urinary tract infection: validation and impact assessment of a clinical prediction rule.

PubMed

Stalenhoef, Janneke E; van der Starre, Willize E; Vollaard, Albert M; Steyerberg, Ewout W; Delfos, Nathalie M; Leyten, Eliane M S; Koster, Ted; Ablij, Hans C; Van't Wout, Jan W; van Dissel, Jaap T; van Nieuwkoop, Cees

2017-06-06

There is a lack of severity assessment tools to identify adults presenting with febrile urinary tract infection (FUTI) at risk for complicated outcome and guide admission policy. We aimed to validate the Prediction Rule for Admission policy in Complicated urinary Tract InfeCtion LEiden (PRACTICE), a modified form of the pneumonia severity index, and to subsequentially assess its use in clinical practice. A prospective observational multicenter study for model validation (2004-2009), followed by a multicenter controlled clinical trial with stepped wedge cluster-randomization for impact assessment (2010-2014), with a follow up of 3 months. Paricipants were 1157 consecutive patients with a presumptive diagnosis of acute febrile UTI (787 in validation cohort and 370 in the randomized trial), enrolled at emergency departments of 7 hospitals and 35 primary care centers in the Netherlands. The clinical prediction rule contained 12 predictors of complicated course. In the randomized trial the PRACTICE included guidance on hospitalization for high risk (>100 points) and home discharge for low risk patients (<75 points), in the control period the standard policy regarding hospital admission was applied. Main outcomes were effectiveness of the clinical prediction rule, as measured by primary hospital admission rate, and its safety, as measured by the rate of low-risk patients who needed to be hospitalized for FUTI after initial home-based treatment, and 30-day mortality. A total of 370 patients were included in the randomized trial, 237 in the control period and 133 in the intervention period. Use of PRACTICE significantly reduced the primary hospitalization rate (from 219/237, 92%, in the control group to 96/133, 72%, in the intervention group, p < 0.01). The secondary hospital admission rate after initial outpatient treatment was 6% in control patients and 27% in intervention patients (1/17 and 10/37; p < 0.001). Although the proposed PRACTICE prediction rule is

Patient-reported outcomes to assess the efficacy of extended-release guaifenesin for the treatment of acute respiratory tract infection symptoms.

PubMed

Albrecht, Helmut; Vernon, Margaret; Solomon, Gail

2012-12-27

Guaifenesin is a component of medicines used to improve symptoms associated with upper respiratory tract infections. Patient-reported outcome instruments are valuable for evaluating symptom improvements; however, a validated tool to assess efficacy of mucoactive drugs does not exist. We compared the efficacy of extended-release guaifenesin with placebo for treatment of symptoms of upper respiratory tract infection using subjective efficacy assessments in a pilot study and confirmed precision of assessments in a validation study. The pilot study was a randomized, double-blind study where patients were dosed with either 1200 mg extended-release guaifenesin (n = 188) or placebo (n = 190), every 12 hours for 7 days. Efficacy was assessed using subjective measures including the Daily Cough and Phlegm Diary, the Spontaneous Symptom Severity Assessment and the Wisconsin Upper Respiratory Symptom Survey. End-of-study assessments were completed by patients and investigator. The validation study consisted of two phases. In Phase I, subjects completed interviews to gather evidence to support the content validity of the Daily Cough and Phlegm Diary, the Spontaneous Symptom Severity Assessment and Patient's End-of-Treatment Assessment. Phase II examined the psychometric properties of assessments evaluated in Phase I of the validation study using data from the pilot study. Subjective measures of efficacy at Day 4 showed the most prominent difference between treatment groups, in favor of guaifenesin. The 8-symptom related questions (SUM8) in the Daily Cough and Phlegm Diary, analyzed as a composite score appeared to be the strongest candidate endpoint for further evaluation. Results from the interviews in Phase I supported the content of the assessments which were validated during Phase II. Treatments were well tolerated. Results from the clinical pilot and validation studies showed that the SUM8 diary scores were robust and reliable for use as efficacy endpoints in studies of

Patient-reported outcomes to assess the efficacy of extended-release guaifenesin for the treatment of acute respiratory tract infection symptoms

PubMed Central

2012-01-01

Background Guaifenesin is a component of medicines used to improve symptoms associated with upper respiratory tract infections. Patient-reported outcome instruments are valuable for evaluating symptom improvements; however, a validated tool to assess efficacy of mucoactive drugs does not exist. We compared the efficacy of extended-release guaifenesin with placebo for treatment of symptoms of upper respiratory tract infection using subjective efficacy assessments in a pilot study and confirmed precision of assessments in a validation study. Methods The pilot study was a randomized, double-blind study where patients were dosed with either 1200 mg extended-release guaifenesin (n = 188) or placebo (n = 190), every 12 hours for 7 days. Efficacy was assessed using subjective measures including the Daily Cough and Phlegm Diary, the Spontaneous Symptom Severity Assessment and the Wisconsin Upper Respiratory Symptom Survey. End-of-study assessments were completed by patients and investigator. The validation study consisted of two phases. In Phase I, subjects completed interviews to gather evidence to support the content validity of the Daily Cough and Phlegm Diary, the Spontaneous Symptom Severity Assessment and Patient’s End-of-Treatment Assessment. Phase II examined the psychometric properties of assessments evaluated in Phase I of the validation study using data from the pilot study. Results Subjective measures of efficacy at Day 4 showed the most prominent difference between treatment groups, in favor of guaifenesin. The 8-symptom related questions (SUM8) in the Daily Cough and Phlegm Diary, analyzed as a composite score appeared to be the strongest candidate endpoint for further evaluation. Results from the interviews in Phase I supported the content of the assessments which were validated during Phase II. Treatments were well tolerated. Conclusions Results from the clinical pilot and validation studies showed that the SUM8 diary scores were robust and

Cocaine-mediated impact on HIV infection in humanized BLT mice

PubMed Central

Kim, Sohn G.; Lowe, Emily L.; Dixit, Dhaval; Seyeon Youn, Cindy; Kim, Irene J.; Jung, James B.; Rovner, Robert; Zack, Jerome A.; Vatakis, Dimitrios N.

2015-01-01

Cocaine abuse has been shown to have broad-ranging effects on human immunity. With regards to HIV infection, in vitro studies have shown that cocaine enhances infection of stimulated lymphocytes. Moreover, cohort studies in the pre- and post-HAART era have linked stimulant abuse with increased HIV pathogenesis. The latter data, however, have been undermined by a series of confounding factors underscoring the importance of controlled in vivo models to fully assess the impact of cocaine use and abuse on HIV infection and pathogenesis. Here, we have infected humanized mice with HIV-1 following acute cocaine exposure to assess the impact on infection. Stimulant exposure resulted in increased inflammatory cytokine expression, accelerated HIV infection, while blunting effector function of cytotoxic T lymphocytes. These data demonstrate cocaine’s multifactorial impact on HIV infection that extends beyond high-risk behavior. PMID:26084721

Hepatocellular carcinoma in children and young patients with chronic HBV infection and the usefulness of alpha-fetoprotein assessment.

PubMed

Tajiri, Hitoshi; Takano, Tomoko; Tanaka, Hideo; Ushijima, Kosuke; Inui, Ayano; Miyoshi, Yoko; Ozono, Keiichi; Abukawa, Daiki; Endo, Takeshi; Brooks, Stephen; Tanaka, Yasuhito

2016-11-01

The aims of the study were to elucidate the clinical characteristics of patients who developed hepatocellular carcinoma (HCC) related to persistent HBV infection since childhood and to investigate usefulness of assessing alpha-fetoprotein (AFP) in this population. A nationwide multicenter survey of children with chronic HBV infection was performed. Among 548 patients, 15 patients developed HCC at the median age of 15 years (range 9-36), including 13 males and 2 females. A case-control comparison showed that HBeAg seroconversion and liver cirrhosis were associated with the occurrence of HCC. Of the 15 HCC patients, 5 were treated with interferon and none of them responded to interferon therapy as compared with 12 of the 17 responders in the control group. Of the 15 patients, 10 died and 9 of the 10 who died never visited any medical facilities until diagnosis of HCC, while the remaining 5 surviving patients never stopped their clinic visits. The usefulness of AFP assessment was shown by the findings that AFP levels were elevated in all HCC cases, that elevations in AFP levels were detected prior to the diagnosis in the surviving patients, and that sensitivity of AFP as a diagnostic test for HCC was very high among 40 patients including our 14 and an additional 26 collected from the literature. HBeAg seroconversion and liver cirrhosis are associated with the occurrence of HCC. Regular measurement of AFP might be helpful to watch for the occurrence of HCC when following children and young patients with chronic HBV infection since childhood. © 2016 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

Analytical studies assessing the association between extreme precipitation or temperature and drinking water-related waterborne infections: a review.

PubMed

Guzman Herrador, Bernardo R; de Blasio, Birgitte Freiesleben; MacDonald, Emily; Nichols, Gordon; Sudre, Bertrand; Vold, Line; Semenza, Jan C; Nygård, Karin

2015-03-27

Determining the role of weather in waterborne infections is a priority public health research issue as climate change is predicted to increase the frequency of extreme precipitation and temperature events. To document the current knowledge on this topic, we performed a literature review of analytical research studies that have combined epidemiological and meteorological data in order to analyze associations between extreme precipitation or temperature and waterborne disease.A search of the databases Ovid MEDLINE, EMBASE, SCOPUS and Web of Science was conducted, using search terms related to waterborne infections and precipitation or temperature. Results were limited to studies published in English between January 2001 and December 2013.Twenty-four articles were included in this review, predominantly from Asia and North-America. Four articles used waterborne outbreaks as study units, while the remaining articles used number of cases of waterborne infections. Results presented in the different articles were heterogeneous. Although most of the studies identified a positive association between increased precipitation or temperature and infection, there were several in which this association was not evidenced. A number of articles also identified an association between decreased precipitation and infections. This highlights the complex relationship between precipitation or temperature driven transmission and waterborne disease. We encourage researchers to conduct studies examining potential effect modifiers, such as the specific type of microorganism, geographical region, season, type of water supply, water source or water treatment, in order to assess how they modulate the relationship between heavy rain events or temperature and waterborne disease. Addressing these gaps is of primary importance in order to identify the areas where action is needed to minimize negative impact of climate change on health in the future.

Intestinal parasitic infection among school children.

PubMed

Shakya, B; Shrestha, S; Madhikarmi, N L; Adhikari, R

2012-01-01

Intestinal parasitosis is a major public health problem of developing countries, children being major victims. Higher prevalence has been reported among school children, mostly in hilly regions of Nepal. This study aims at assessing prevalence of intestinal parasitosis among school children of a school in a border town of Nepal and the associated factors. Fecal samples from the students were examined by direct smear technique and result was correlated with their socioeconomic status and hygienic behavior. The chi-square test was used for analytical assessment. The prevalence rate was 13.9%, girls being highly infected (19.1%) than boys (10.3%) (P>0.05). Entamoeba histolytica (36.0%) was the commonest parasite followed by A. lumbricoides (28.0%). The highest positive rate was found among children of 5 years and less age (29.2%) and least among those above 12 years (5.3%) (P>0.05). Those from family size 5 and less than 5 were least infected (10.5%). Children of illiterate parents (16.7%) and farmers (17.1%) were more infected than literate ones and non-farmers (P>0.05). 8.7% of positive children had multi-parasitic infection. Children drinking untreated water (15.0%) were more infected than those drinking treated water (5.5%) (P>0.05). Intestinal parasitic infection was found among 17% school children. Awareness on infectious diseases, improving hygiene, and application of supportive programs for parents to elevate socioeconomic conditions may reduce the burden of infection.

Infections and apparent life-threatening events.

PubMed

Altman, Robin L; Li, Karl I; Brand, Donald A

2008-05-01

The need for routine sepsis evaluation in patients who have experienced an apparent life-threatening event but lack signs of infection remains controversial. To assess their risk of a serious occult bacterial infection, records were reviewed of 95 infants in whom infections were discovered during their inpatient evaluation after an apparent life-threatening event. Noted for each patient was the presence of any suggestive findings that would have prompted a physician to consider the given type of infection in the differential diagnosis. Thirty patients had bacterial infections; all but 5 had suggestive findings. The exceptions included 1 patient with pneumonia and 4 with urinary tract infections. None of the remaining 25 patients had occult bacterial infections. In patients with an apparent life-threatening event who appear well and lack signs suggestive of a serious bacterial infection, it may be possible to forego routine sepsis evaluation beyond a chest radiograph and urine culture without risking a serious missed diagnosis.

Targeted Assessment for Prevention of Healthcare-Associated Infections: A New Prioritization Metric

PubMed Central

Soe, Minn M.; Gould, Carolyn V.; Pollock, Daniel; Edwards, Jonathan

2015-01-01

OBJECTIVE To develop a method for calculating the number of healthcare-associated infections (HAIs) that must be prevented to reach a HAI reduction goal and identifying and prioritizing healthcare facilities where the largest reductions can be achieved. SETTING Acute care hospitals that report HAI data to the Centers for Disease Control and Prevention’s National Healthcare Safety Network. METHODS The cumulative attributable difference (CAD) is calculated by subtracting a numerical prevention target from an observed number of HAIs. The prevention target is the product of the predicted number of HAIs and a standardized infection ratio goal, which represents a HAI reduction goal. The CAD is a numeric value that if positive is the number of infections to prevent to reach the HAI reduction goal. We calculated the CAD for catheter-associated urinary tract infections for each of the 3,639 hospitals that reported such data to National Healthcare Safety Network in 2013 and ranked the hospitals by their CAD values in descending order. RESULTS Of 1,578 hospitals with positive CAD values, preventing 10,040 catheter-associated urinary tract infections at 293 hospitals (19%) with the highest CAD would enable achievement of the national 25% catheter-associated urinary tract infection reduction goal. CONCLUSION The CAD is a new metric that facilitates ranking of facilities, and locations within facilities, to prioritize HAI prevention efforts where the greatest impact can be achieved toward a HAI reduction goal. PMID:26310913

Relapse, re-infection and mixed infections in tuberculosis disease.

PubMed

McIvor, Amanda; Koornhof, Hendrik; Kana, Bavesh Davandra

2017-04-01

Tuberculosis (TB) disease can be characterized by genotypic and phenotypic complexity in Mycobacterium tuberculosis bacilli within a single patient. This microbiological heterogeneity has become an area of intense study due its perceived importance in drug tolerance, drug resistance and as a surrogate measure of transmission rates. This review presents a descriptive analysis of research describing the prevalence of mixed-strain TB infections in geographically distinct locations. Despite significant variation in disease burden and a rampant human immunodeficiency virus (HIV)-TB co-epidemic, there was no difference in the prevalence range of mixed infections reported in African countries when compared to the rest of the world. The occurrence of recurrent TB was associated with a higher prevalence of mixed-strain infections, but this difference was not reported as statistically significant. These interpretations were limited by differences in the design and overall size of the studies assessed. Factors such as sputum quality, culture media, number of repeated culture steps, molecular typing methods and HIV-infection status can affect the detection of mixed-strain infection. It is recommended that future clinical studies should focus on settings with varying TB burdens, with a common sample processing protocol to gain further insight into these phenomena and develop novel transmission blocking strategies. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Assessing the impact of a food supplement on the nutritional status and body composition of HIV-infected Zambian women on ARVs.

PubMed

Zulu, Rodah M; Byrne, Nuala M; Munthali, Grace K; Chipeta, James; Handema, Ray; Musonda, Mofu; Hills, Andrew P

2011-09-21

Zambia is a sub-Saharan country with one of the highest prevalence rates of HIV, currently estimated at 14%. Poor nutritional status due to both protein-energy and micronutrient malnutrition has worsened this situation. In an attempt to address this combined problem, the government has instigated a number of strategies, including the provision of antiretroviral (ARV) treatment coupled with the promotion of good nutrition. High-energy protein supplement (HEPS) is particularly promoted; however, the impact of this food supplement on the nutritional status of people living with HIV/AIDS (PLHA) beyond weight gain has not been assessed. Techniques for the assessment of nutritional status utilising objective measures of body composition are not commonly available in Zambia. The aim of this study is therefore to assess the impact of a food supplement on nutritional status using a comprehensive anthropometric protocol including measures of skinfold thickness and circumferences, plus the criterion deuterium dilution technique to assess total body water (TBW) and derive fat-free mass (FFM) and fat mass (FM). This community-based controlled and longitudinal study aims to recruit 200 HIV-infected females commencing ARV treatment at two clinics in Lusaka, Zambia. Data will be collected at four time points: baseline, 4-month, 8-month and 12-month follow-up visits. Outcome measures to be assessed include body height and weight, body mass index (BMI), body composition, CD4, viral load and micronutrient status. This protocol describes a study that will provide a longitudinal assessment of the impact of a food supplement on the nutritional status of HIV-infected females initiating ARVs using a range of anthropometric and body composition assessment techniques. Pan African Clinical Trial Registry PACTR201108000303396.

Economics of infection control surveillance technology: cost-effective or just cost?

PubMed

Furuno, Jon P; Schweizer, Marin L; McGregor, Jessina C; Perencevich, Eli N

2008-04-01

Previous studies have suggested that informatics tools, such as automated alert and decision support systems, may increase the efficiency and quality of infection control surveillance. However, little is known about the cost-effectiveness of these tools. We focus on 2 types of economic analyses that have utility in assessing infection control interventions (cost-effectiveness analysis and business-case analysis) and review the available literature on the economics of computerized infection control surveillance systems. Previous studies on the effectiveness of computerized infection control surveillance have been limited to assessments of whether these tools increase the sensitivity and specificity of surveillance over traditional methods. Furthermore, we identified only 2 studies that assessed the costs associated with computerized infection control surveillance. Thus, it remains unknown whether computerized infection control surveillance systems are cost-effective and whether use of these systems improves patient outcomes. The existing data are insufficient to allow for a summary conclusion on the cost-effectiveness of infection control surveillance technology. All future studies of computerized infection control surveillance systems should aim to collect outcomes and economic data to inform decision making and assist hospitals with completing business-cases analyses.

Absence of Mycobacterium bovis infection in dogs and cats residing on infected cattle farms: Michigan, 2002

PubMed Central

WILKINS, M. J.; BARTLETT, P. C.; BERRY, D. E.; PERRY, R. L.; FITZGERALD, S. D.; BERNARDO, T. M.; THOEN, C. O.; KANEENE, J. B.

2008-01-01

SUMMARY A cross-sectional field study was performed to evaluate infection in dogs and cats living on farms with Mycobacterium bovis-infected cattle. The purpose was to determine pet infection status and assess their risk to farm families and/or tuberculosis-free livestock. Data and specimens were collected from 18 cats and five dogs from nine participating farms. ELISA testing for M. bovis and M. avium was conducted. Fifty-one biological samples were cultured; all were negative for M. bovis, although other Mycobacterium species were recovered. No radiographic, serological or skin test evidence of mycobacterial infection was found. These negative results may be due to the low level of M. bovis infection in the cattle and the limited duration of exposure of pets to infected cattle residing on the same farm. No evidence was found to indicate that pets residing on M. bovis-infected Michigan cattle farms pose a risk to humans or M. bovis-free livestock; however, precautionary advice for farm owners was provided. PMID:18325127

Assessing appearance-related disturbances in HIV-infected men who have sex with men (MSM): psychometrics of the body change and distress questionnaire-short form (ABCD-SF).

PubMed

Blashill, Aaron J; Wilson, Johannes M; Baker, Joshua S; Mayer, Kenneth H; Safren, Steven A

2014-06-01

Appearance-related disturbances are common among HIV-infected MSM; however, to date, there have been limited options in the valid assessment of this construct. The aim of the current study was to assess the structural, internal, and convergent validity of the assessment of body change distress questionnaire (ABCD) and its short version. Exploratory and confirmatory factor analyses indicated that both versions fit the data well. Four subfactors were revealed measuring the following body disturbance constructs: (1) negative affect about appearance, (2) HIV health-related outcomes and stigma, (3) eating and exercise confusion, and (4) ART non-adherence. The subfactors and total scores revealed bivariate associations with salient health outcomes, including depressive symptoms, HIV sexual transmission risk behaviors, and ART non-adherence. The ABCD and its short form, offer valid means to assess varied aspects of body image disturbance among HIV-infected MSM, and require modest participant burden.

Assessing the Macro-Level Correlates of Malware Infections Using a Routine Activities Framework.

PubMed

Holt, Thomas J; Burruss, George W; Bossler, Adam M

2018-05-01

The ability to gain unauthorized access to computer systems to engage in espionage and data theft poses a massive threat to individuals worldwide. There has been minimal focus, however, on the role of malicious software, or malware, which can automate this process. This study examined the macro-correlates of malware infection at the national level by using an open repository of known malware infections and utilizing a routine activities framework. Negative inflated binomial models for counts indicated that nations with greater technological infrastructure, more political freedoms, and with less organized crime financial impact were more likely to report malware infections. The number of Computer Emergency Response Teams (CERTs) in a nation was not significantly related with reported malware infection. The implications of the study for the understanding of malware infection, routine activity theory, and target-hardening strategies are discussed.

Assessment of the value of detecting specific IgA antibodies for the diagnosis of a recently acquired primary Toxoplasma infection.

PubMed

Nascimento, Fernanda Santos; Suzuki, Lisandra Akemi; Rossi, Cláudio Lúcio

2008-08-01

To assess the value of detecting IgA antibodies for the diagnosis of a recently acquired primary Toxoplasma infection. IgA antibodies were screened in sera from 87 women with different serological profiles of Toxoplasma gondii IgM and IgG antibodies and Toxoplasma-specific IgG avidity. The IgM and IgG antibodies and the IgG avidity were measured with an automated Vitek Immuno Diagnostic Assay System (VIDAS). Anti-T.gondii IgA was measured with Platelia Toxo IgA TMB kits. All 12 sera obtained from women with clinical and/or serological evidence of a recently acquired Toxoplasma infection were positive for IgA. In 42 serum samples obtained more than 6 months after T. gondii infection from women with no clinical evidence of infection, but who had a positive IgM test and a high IgG avidity index, the IgA-enzyme linked immunosorbent assay (ELISA) test results were positive, negative, and doubtful in 16 (38.1%), 23 (54.8%), and 3 (7.1%) sera, respectively. In eight women, IgA was detected in sera collected more than 9 months after the onset of infection. The IgA test result was also positive in 11 of 12 sera (91.7%) obtained from women with no clinical evidence of toxoplasmosis, but who had a positive IgM test and a borderline IgG avidity index. The IgA-ELISA was negative in 21 sera obtained more than 2 years after the onset of T. gondii infection from women with no clinical evidence of toxoplasmosis, but who had a negative IgM test and a positive IgG test. These results show that IgA is not a dependable marker for a recently acquired primary Toxoplasma infection. Copyright (c) 2008 John Wiley & Sons, Ltd.

Assessment of Theileria equi and Babesia caballi infections in equine populations in Egypt by molecular, serological and hematological approaches.

PubMed

Mahmoud, Mona S; El-Ezz, Nadia T Abu; Abdel-Shafy, Sobhy; Nassar, Somia A; El Namaky, Amira H; Khalil, Wagdy K B; Knowles, Don; Kappmeyer, Lowell; Silva, Marta G; Suarez, Carlos E

2016-05-04

Equine piroplasmosis (EP) caused by Theileria equi, Babesia caballi, or both, contributes to significant economic loss in the equine industry and remains uncontrolled in Egypt. This study focuses on surveying T. equi and B. caballi infections and hematological disorders in equine populations in Egypt. Theileria equi and B. caballi infections were assessed in blood from 88 horses and 51 donkeys in Egypt using light microscopy, indirect immunofluorescent antibody test (IFAT), nested PCR (nPCR), and competitive-ELISA (cELISA) assays. PCR products were examined for specificity by DNA sequencing. Hematological alterations were evaluated using a standard cell counter. Microscopic analysis revealed EP infection in 11.4% and 17.8% of horses and donkeys respectively. IFAT detected 23.9% and 17.0% infection of T. equi and B. caballi, respectively, in horses, and 31.4% of T. equi and B. caballi in donkeys. T. equi cELISA detected 14.8% and 23.5% positive horses and donkeys, respectively, but the B. caballi RAP-1-based cELISA failed to detect any positives, a result hypothesized to be caused by sequence polymorphism found in the rap-1 genes. Nested-PCR analysis identified 36.4% and 43.1% positive horses and donkeys, respectively for T. equi and it also identified 19.3% and 15.7% positive horses and donkeys, respectively for B. caballi. The overall EP incidence found in the population under study was relatively high and comparable regardless of the diagnostic method used (56.8% using nPCR and 48.9% using IFAT). Hematologic analysis revealed macrocytic hypochromic anemia and thrombocytopenia in all piroplasma-infected horses. The data confirm relatively high levels of EP, likely causing hematological abnormalities in equines in Egypt, and also suggest the need for an improved serological test to diagnose B. caballi infection in this region.

Comparison of the ACC/AHA and Framingham algorithms to assess cardiovascular risk in HIV-infected patients.

PubMed

Pinto Neto, Lauro Ferreira da Silva; Dias, Fernanda Rezende; Bressan, Flavia Feres; Santos, Carolina Rocio Oliveira

The aim of this study was to compare the predictions of Framingham cardiovascular (CV) risk score (FRS) and the American College of Cardiology/American Heart Association (ACC/AHA) risk score in an HIV outpatient clinic in the city of Vitoria, Espirito Santo, Brazil. In a cross-sectional study 341 HIV infected patients over 40 years old consecutively recruited were interviewed. Cohen's kappa coefficient was used to assess agreement between the two algorithms. 61.3% were stratified as low risk by Framingham score, compared with 54% by ACC/AHA score (Spearman correlation 0.845; p<0.000). Only 26.1% were classified as cardiovascular high risk by Framingham compared to 46% by ACC/AHA score (Kappa=0.745; p<0.039). Only one out of eight patients had cardiovascular high risk by Framingham at the time of a myocardial infarction event registered up to five years before the study period. Both cardiovascular risk scores but especially Framingham underestimated high-risk patients in this HIV-infected population. Copyright © 2017 Sociedade Brasileira de Infectologia. Published by Elsevier Editora Ltda. All rights reserved.

Chronic prostatic infection and inflammation by Propionibacterium acnes in a rat prostate infection model.

PubMed

Olsson, Jan; Drott, Johanna Bergh; Laurantzon, Lovisa; Laurantzon, Oscar; Bergh, Anders; Elgh, Fredrik

2012-01-01

Chronic inflammation in the prostate, seen as infiltration of inflammatory cells into the prostate gland in histological samples, affects approximately half the male population without indication of prostate disease, and is almost ubiquitous in patients diagnosed with benign prostate hyperplasia and cancer. Several studies have demonstrated the gram-positive bacterium Propionibacterium acnes to be frequently present in prostate tissue from men suffering from prostate disease. P. acnes has been shown to be associated with histological inflammation in human prostatectomy specimens, and also to induce strong inflammatory response in prostate-derived tissue culture models. The present paper describes a rat model for assessment of the pathogenic potential of P. acnes in prostate. Prostate glands of Sprague Dawley rats (n = 98) were exposed via an abdominal incision and live P. acnes or, in control rats, saline were injected into the ventral and dorso-lateral lobes. Rats were sacrificed 5 days, 3 weeks, 3 months and 6 months post infection, and prostate tissue was analyzed for bacterial content and histological inflammation. Rat sera were assessed for levels of CRP and anti-P. acnes IgG. Live P. acnes could be recovered from the dorso-lateral lobes up to 3 months post infection, while the ventral lobes were cleared from bacteria at that time. In samples up to 3 months post infection, the dorso-lateral lobes exhibited intense focal inflammation. CRP and IgG levels were elevated throughout the span of the experiment, and reached maximum levels 3 weeks and 3 months post infection, respectively. We show that P. acnes have the potential to cause chronic infection in previously healthy prostate, and that the infection has potential to cause chronic histological inflammation in the infected tissue. The high prevalence of P. acnes in human prostate tissue calls for resolution of pathogenic details. The present rat model suggests that complications such as chronic

Chronic Prostatic Infection and Inflammation by Propionibacterium acnes in a Rat Prostate Infection Model

PubMed Central

Olsson, Jan; Drott, Johanna Bergh; Laurantzon, Lovisa; Laurantzon, Oscar; Bergh, Anders; Elgh, Fredrik

2012-01-01

Chronic inflammation in the prostate, seen as infiltration of inflammatory cells into the prostate gland in histological samples, affects approximately half the male population without indication of prostate disease, and is almost ubiquitous in patients diagnosed with benign prostate hyperplasia and cancer. Several studies have demonstrated the Gram-positive bacterium Propionibacterium acnes to be frequently present in prostate tissue from men suffering from prostate disease. P. acnes has been shown to be associated with histological inflammation in human prostatectomy specimens, and also to induce strong inflammatory response in prostate-derived tissue culture models. The present paper describes a rat model for assessment of the pathogenic potential of P. acnes in prostate. Prostate glands of Sprague Dawley rats (n = 98) were exposed via an abdominal incision and live P. acnes or, in control rats, saline were injected into the ventral and dorso-lateral lobes. Rats were sacrificed 5 days, 3 weeks, 3 months and 6 months post infection, and prostate tissue was analyzed for bacterial content and histological inflammation. Rat sera were assessed for levels of CRP and anti-P. acnes IgG. Live P. acnes could be recovered from the dorso-lateral lobes up to 3 months post infection, while the ventral lobes were cleared from bacteria at that time. In samples up to 3 months post infection, the dorso-lateral lobes exhibited intense focal inflammation. CRP and IgG levels were elevated throughout the span of the experiment, and reached maximum levels 3 weeks and 3 months post infection, respectively. We show that P. acnes have the potential to cause chronic infection in previously healthy prostate, and that the infection has potential to cause chronic histological inflammation in the infected tissue. The high prevalence of P. acnes in human prostate tissue calls for resolution of pathogenic details. The present rat model suggests that complications such as chronic

Assessing user preferences for sexually transmitted infection testing services: a discrete choice experiment

PubMed Central

Llewellyn, Carrie; Pollard, Alex; Lagarde, Mylene; Richardson, Daniel; Cairns, John; Fisher, Martin; Smith, Helen

2012-01-01

Objective To assess user preferences for different aspects of sexually transmitted infection (STI) testing services. Design A discrete choice experiment. Setting 14 centres offering tests for STIs in East Sussex, England. Participants People testing for STIs. Main outcome measure (Adjusted) ORs in relation to preferred service characteristics. Results 3358 questionnaires were returned; mean age 26 (SD 9.4) years. 70% (2366) were recruited from genitourinary medicine (GUM) clinics. The analysis suggested that the most important characteristics to users were whether ‘staff had specialist STI knowledge’ compared with ‘staff without it’ (OR 2.55; 95% CI 2.47 to 2.63) and whether ‘tests for all STIs’ were offered rather than ‘some’ (OR 2.19; 95% CI 2.12 to 2.25). They remained the most important two service characteristics despite stratifying the analysis by variables such as age and sex. Staff levels of expertise were viewed as particularly important by people attending CASH centres, women and non-men who have sex with men. A ‘text or call to a mobile phone’ and ‘dropping in and waiting’ were generally the preferred methods of results reporting and appointment system, respectively. Conclusions This study suggests that people testing for STIs place particular importance on testing for all infections rather than some and staff with specialist STI knowledge. Thus, targets based purely on waiting up to 48 h for an appointment are misguided from a user perspective. PMID:22661632

Comprehensive assessment of peripheral blood TCRβ repertoire in infectious mononucleosis and chronic active EBV infection patients.

PubMed

Liu, Shenglin; Zhang, Qian; Huang, Dongli; Zhang, Wenli; Zhong, Fengluan; Feng, Jia; Chen, Xueru; Meng, Qingxiang; Chen, Xiaofan; Zhang, Wei; Zhang, Hongyu

2017-04-01

Epstein-Barr virus (EBV) primary infection is usually asymptomatic, but it sometimes progresses to infectious mononucleosis (IM). Occasionally, some people develop chronic active EBV infection (CAEBV) with underlying immunodeficiency, which belongs to a continuous spectrum of EBV-associated lymphoproliferative disorders (EBV + LPD) with heterogeneous clinical presentations and high mortality. It has been well established that T cell-mediated immune response plays a critical role in the disease evolution of EBV infection. Recently, high-throughput sequencing of the hypervariable complementarity-determining region 3 (CDR3) segments of the T cell receptor (T cell receptor β (TCRβ)) has emerged as a sensitive approach to assess the T cell repertoire. In this study, we fully characterized the diversity of peripheral blood TCRβ repertoire in IM (n = 6) and CAEBV patients (n = 5) and EBV-seropositive controls (n = 5). Compared with the healthy EBV-seropositive controls, both IM and CAEBV patients demonstrate a significant decrease in peripheral blood TCRβ repertoire diversity, basically, including narrowed repertoire breadth, highly expanded clones, and skewed CDR3 length distribution. However, there is no significant difference between IM and CAEBV patients. Furthermore, we observed some disease-related preferences in TRBV/TRBJ usage and combinations, as well as lots of T cell clones shared by different groups (unique or overlapped) involved in public T cell responses, which provide more detailed insights into the divergent disease evolution.

Gender-based screening for chlamydial infection and divergent infection trends in men and women.

PubMed

Rogers, Susan M; Turner, Charles F; Miller, William C; Erbelding, Emily; Eggleston, Elizabeth; Tan, Sylvia; Roman, Anthony; Hobbs, Marcia; Chromy, James; Muvva, Ravikiran; Ganapathi, Laxminarayana

2014-01-01

To assess the potential impact of chlamydial screening policy that recommends routine screening of women but not men. Population surveys of probability samples of Baltimore adults aged 18 to 35 years in 1997-1998 and 2006-2009 collected biospecimens to estimate trends in undiagnosed chlamydial infection. Survey estimates are compared to surveillance data on diagnosed chlamydial infections reported to the Health Department. Prevalence of undiagnosed chlamydial infection among men increased from 1.6% to 4.0%, but it declined from 4.3% to 3.1% among women (p = 0.028 for test of interaction). The annual (average) number of diagnosed infections was substantially higher among women than men in both time periods and increased among both men and women. Undiagnosed infection prevalence was substantially higher among black than non-black adults (4.0% vs 1.2%, p = 0.042 in 1997-98 and 5.5% vs 0.7%, p<0.001 in 2006-09). Divergent trends in undiagnosed chlamydial infection by gender parallel divergent screening recommendations that encourage chlamydial testing for women but not for men.

Protocols to Assess Coagulation Following In Vitro Infection with Hemorrhagic Fever Viruses

DTIC Science & Technology

2016-05-25

Likewise, patients infected with the flavivirus Dengue virus who develop Dengue hemorrhagic fever (DHF) have increased levels of TF in their sera/plasma...cells, coagulation and fibrinolysis in children with Dengue virus infection. Thrombosis and haemostasis 97:627-634. 5. Geisbert TW, Hensley LE

Rapid alkaline methylene blue supravital staining for assessment of anterior segment infections.

PubMed

Kiuchi, Katsuji

2016-01-01

To present the Löffler's alkaline methylene blue technique of staining eye discharges in eyes with anterior segment infections. The Löffler's alkaline methylene blue staining method is a simple staining technique that can be used to differentiate bacterial, viral, and fungal infections. It is a cationic dye that stains cells blue because the positively charged dye is attracted to negatively charged particles such as polyphosphates, DNAs, and RNAs. Specimens collected from patients by swabbing are smeared onto microscope slides and the methylene blue solution is dropped on the slide. The slide is covered with a glass cover slip and examined under a microscope. The entire time from the collection to the viewing is about 30 seconds. Histopathological images of the conjunctival epithelial cells and neutrophils in eye discharges were dyed blue and the nuclei were stained more intensely blue. Bacterial infections consisted mainly of neutrophils, and viral infections consisted mainly of lymphocytes. Löffler's alkaline methylene blue staining can be done in about 30 seconds for diagnosis. Even though this is a one color stain, it is possible to infer the cause of the infection by detection of the absence of bacteria and/or fungi in context of the differential distribution of neutrophils and lymphocytes.

A prospective assessment of cytomegalovirus infection in active inflammatory bowel disease.

PubMed

de Saussure, P; Lavergne-Slove, A; Mazeron, M-C; Alain, S; Matuchansky, C; Bouhnik, Y

2004-12-01

The prevalence and clinical significance of cytomegalovirus infection is reportedly high in patients with refractory inflammatory bowel disease but is unknown in unselected patients with active disease. In patients admitted for active inflammatory bowel disease, we prospectively studied the presence and significance of cytomegalovirus infection using anti-cytomegalovirus antibodies, cytomegalovirus viraemia and antigenaemia and cytomegalovirus inclusions and cytomegalovirus immunochemistry staining in ileocolonic biopsies. A total of 64 patients were included (ulcerative colitis, n = 23; Crohn's disease, n = 41), 18 of whom had been on high-dose oral steroids and 11 on immunosuppressants. Anti-cytomegalovirus IgG and IgM were positive in 42 (66%) and 3 (5%) patients respectively. Blood or urine cytomegalovirus replication markers were found in 4 (6%) patients, all of whom had ulcerative colitis. Three patients had cytomegalovirus viraemia and received anti-viral treatment with ganciclovir. Only one of these patients had cytomegalovirus antigenaemia and also associated biopsy-proven cytomegalovirus colitis, probably as a primary cytomegalovirus infection. This patient is the only one who benefitted from anti-viral therapy. Cytomegalovirus infection is infrequent in in-patients with active inflammatory bowel disease. Systematic search of cytomegalovirus replication markers should not be performed. Isolated viraemia without associated antigenaemia or direct demonstration of cytomegalovirus in ileocolonic biopsies does not warrant anti-viral therapy.

Incidence and persistence of carcinogenic genital human papillomavirus infections in young women with or without Chlamydia trachomatis co-infection

PubMed Central

Vriend, Henrike J; Bogaards, Johannes A; van Bergen, Jan E A M; Brink, Antoinette A T P; van den Broek, Ingrid V F; Hoebe, Christian J P A; King, Audrey J; van der Sande, Marianne A B; Wolffs, Petra F G; de Melker, Hester E

2015-01-01

We assessed whether infection with chlamydia increases the incidence of carcinogenic human papillomavirus (HPV) infections and if HPV persistence is affected by chlamydia co-infection. For 1982 women (16–29 years-old) participating in two consecutive rounds of a chlamydia screening implementation trial, swabs were polymerase chain reaction tested to detect chlamydia and 14 carcinogenic HPV genotypes. HPV type-specific incidence and persistence rates were stratified for chlamydia positivity at follow-up. Associations were assessed by multilevel logistic regression analyses with correction for sexual risk factors. HPV type-specific incidence ranged from 1.4% to 8.9% and persistence from 22.7% to 59.4% after a median follow-up of 11 months (interquartile range: 11–12). Differences in 1-year HPV persistence rates between chlamydia -infected and noninfected women were less distinct than differences in HPV incidence rates (pooled adjusted odds ratios of 1.17 [95% CI: 0.69–1.96] and 1.84 [95% CI: 1.36–2.47], respectively). The effect of chlamydia co-infection on HPV-infection risk did not significantly differ by HPV genotype. In conclusion, infection with chlamydia increases the risk of infection by carcinogenic HPV types and may enhance persistence of some HPV types. Although these findings could reflect residual confounding through unobserved risk factors, our results do give reason to explore more fully the association between chlamydia and HPV type-specific acquisition and persistence. PMID:26194784

Prevalence and risk factors of Clostridium difficile infection in patients hospitalized for flare of inflammatory bowel disease: a retrospective assessment.

PubMed

Regnault, Helene; Bourrier, Anne; Lalande, Valerie; Nion-Larmurier, Isabelle; Sokol, Harry; Seksik, Philippe; Barbut, Frederic; Cosnes, Jacques; Beaugerie, Laurent

2014-12-01

Recent studies have identified a high frequency of Clostridium difficile infections in patients with active inflammatory bowel disease. To retrospectively assess the determinants and results of Clostridium difficile testing upon the admission of patients hospitalized with active inflammatory bowel disease in a tertiary care centre and to determine the predicting factors of Clostridium difficile infections. We reviewed all admissions from January 2008 and December 2010 for inflammatory bowel disease flare-ups. A toxigenic culture and a stool cytotoxicity assay were performed for all patients tested for Clostridium difficile. Out of 813 consecutive stays, Clostridium difficile diagnostic assays have been performed in 59% of inpatients. The independent predictive factors for the testing were IBD (ulcerative colitis: OR 2.0, 95% CI 1.5-2.9; p<0.0001) and colonic involvement at admission (OR 2.2, 95% CI 1.5-3.1, p<0.0001). Clostridium difficile infection was present in 7.0% of the inpatients who underwent testing. In a multivariate analysis, the only independent predictor was the intake of nonsteroidal anti-inflammatory drugs within the two months before admission (OR 3.8, 95% CI 1.2-12.3; p=0.02). Clostridium difficile infection is frequently associated with active inflammatory bowel disease. Our study suggests that a recent intake of nonsteroidal anti-inflammatory drugs is a risk factor for inflammatory bowel disease -associated Clostridium difficile infection. Copyright © 2014 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

In vitro encystment of Himasthla elongata cercariae (Digenea, Echinostomatidae) in the haemolymph of blue mussels Mytilus edulis as a tool for assessing cercarial infectivity and molluscan susceptibility.

PubMed

Levakin, I A; Losev, E A; Nikolaev, K E; Galaktionov, K V

2013-06-01

Infectivity of Himasthla elongata cercariae to mussels, their second intermediate hosts, and resistance by these hosts to infection were assessed on the basis of the cercariae's ability to encyst in mussel haemolymph in vitro. A series of experimental in vivo infections of mussels with batches of cercariae, each batch released from a different single infected mollusc and referred to as a clone (due to their shared genotype), demonstrated that the results of the in vitro tests corresponded to the actual indices of infectivity/susceptibility of the parasites and their hosts. Most cercarial clones had high infectivity, with a few clones having very high or, at the other extreme, very low infectivity. A similar pattern was revealed in mussel resistance to cercarial infection. Most of the molluscs tested were moderately susceptible to cercarial infection, but at each extreme a small fraction (less than 10%) displayed very high or very low susceptibility. It was shown that there were no totally compatible or totally incompatible 'cercaria clone/mussel' combinations. Results obtained are compared with the data on intra-population variability using the characters parasite infectivity/host compatibility for trematode/mollusc-first intermediate host associations. Results are made relevant to actual infection levels in mussel settlements at the White Sea.

Assessment of quality of life in patients with post kalaazar dermal leishmaniasis.

PubMed

Pal, Biplab; Murti, Krishna; Siddiqui, Niyamat Ali; Das, Pradeep; Lal, Chandra Shekhar; Babu, Rajendra; Rastogi, Manoj Kumar; Pandey, Krishna

2017-07-24

Post kala-azar dermal leishmaniasis (PKDL) is a dermatological disorder caused by protozoal parasite Leishmania donovani. PKDL cases are thought to be a reservoir of parasites and may increase cases of visceral leishmaniasis. The disease is not life threatening but cosmetic disfigurement associated with it may impair the patients' quality of life. This study aimed to assess the health related quality of life in patients with post kalaazar dermal leishmanasis for the first time. A total of 92 PKDL cases and 96 healthy participants filled out the questionnaires. The Dermatology Life Quality Index (DLQI) and SF 36 questionnaire were used to assess the quality of life. Data on socio-demographic and clinical features were also collected. The collected data were analyzed by using SPSS software (version 16), Student's t-test, analysis of variance (ANOVA) was applied for comparison of means. PKDL patients experienced very large impact on their quality of life. The mean score of DLQI was 11.41. Highest impact was found in symptoms and feelings and lowest impact was observed for personal relationship domain. Patients below 20 years age group found to have lower quality of life. There was a significant difference in mean DLQI scores with regard to age and severity of lesions (P < 0.05). No significant difference was observed with respect to gender, duration and location of lesions (p > 0.05). PKDL significantly impaired the patient's quality of life. Further studies to assess the impact of treatment on quality of life in these patients are recommended.

Portable Ultraviolet Light Surface-Disinfecting Devices for Prevention of Hospital-Acquired Infections: A Health Technology Assessment

PubMed Central

Nikitovic-Jokic, Milica; Kabali, Conrad; Li, Chunmei; Higgins, Caroline

2018-01-01

Background Hospital-acquired infections (HAIs) are infections that patients contract while in the hospital that were neither present nor developing at the time of admission. In Canada an estimated 10% of adults with short-term hospitalization have HAIs. According to 2003 Canadian data, between 4% and 6% of these patients die from these infections. The most common HAIs in Ontario are caused by Clostridium difficile. The standard method of reducing and preventing these infections is decontamination of patient rooms through manual cleaning and disinfection. Several portable no-touch ultraviolet (UV) light systems have been proposed to supplement current hospital cleaning and disinfecting practices. Methods We searched for studies published from inception of UV disinfection technology to January 23, 2017. We compared portable UV surface-disinfecting devices used together with standard hospital room cleaning and disinfecting versus standard hospital cleaning and disinfecting alone. The primary outcome was HAI from C. difficile. Other outcomes were combined HAIs, colonization (i.e., carrying an infectious agent without exhibiting disease symptoms), and the HAI-associated mortality rate. We used Grading of Recommendations Assessment, Development, and Evaluation (GRADE) to rate the quality of evidence of included studies. We also performed a 5-year budget impact analysis from the hospital's perspective. This assessment was limited to portable devices and did not examine wall mounted devices, which are used in some hospitals. Results The database search for the clinical review yielded 10 peer-reviewed publications that met eligibility criteria. Three studies focused on mercury UV-C–based technology, seven on pulsed xenon UV technology. Findings were either inconsistent or produced very low-quality evidence using the GRADE rating system. The intervention was effective in reducing the rate of the composite outcome of HAIs (combined) and colonization (but quality of evidence

Assessing the impact of a food supplement on the nutritional status and body composition of HIV-infected Zambian women on ARVs

PubMed Central

2011-01-01

Background Zambia is a sub-Saharan country with one of the highest prevalence rates of HIV, currently estimated at 14%. Poor nutritional status due to both protein-energy and micronutrient malnutrition has worsened this situation. In an attempt to address this combined problem, the government has instigated a number of strategies, including the provision of antiretroviral (ARV) treatment coupled with the promotion of good nutrition. High-energy protein supplement (HEPS) is particularly promoted; however, the impact of this food supplement on the nutritional status of people living with HIV/AIDS (PLHA) beyond weight gain has not been assessed. Techniques for the assessment of nutritional status utilising objective measures of body composition are not commonly available in Zambia. The aim of this study is therefore to assess the impact of a food supplement on nutritional status using a comprehensive anthropometric protocol including measures of skinfold thickness and circumferences, plus the criterion deuterium dilution technique to assess total body water (TBW) and derive fat-free mass (FFM) and fat mass (FM). Methods/Design This community-based controlled and longitudinal study aims to recruit 200 HIV-infected females commencing ARV treatment at two clinics in Lusaka, Zambia. Data will be collected at four time points: baseline, 4-month, 8-month and 12-month follow-up visits. Outcome measures to be assessed include body height and weight, body mass index (BMI), body composition, CD4, viral load and micronutrient status. Discussion This protocol describes a study that will provide a longitudinal assessment of the impact of a food supplement on the nutritional status of HIV-infected females initiating ARVs using a range of anthropometric and body composition assessment techniques. Trial Registration Pan African Clinical Trial Registry PACTR201108000303396. PMID:21936938

Catheter-Associated Urinary Tract Infections

MedlinePlus

... Personnel PPE Training Infection Control Assessment Tools Water Management Programs Map: HAI Prevention Activities Research CDC Supported Projects Prevention Epicenters (PE) Healthcare Safety Research (SHEPheRD) Environmental ...

Types of Healthcare-Associated Infections

MedlinePlus

... Personnel PPE Training Infection Control Assessment Tools Water Management Programs Map: HAI Prevention Activities Research CDC Supported Projects Prevention Epicenters (PE) Healthcare Safety Research (SHEPheRD) Environmental ...

Carbapenem-Resistant Enterobacteriaceae (CRE) Infection

MedlinePlus

... Personnel PPE Training Infection Control Assessment Tools Water Management Programs Map: HAI Prevention Activities Research CDC Supported Projects Prevention Epicenters (PE) Healthcare Safety Research (SHEPheRD) Environmental ...

Laboratory-associated infections and biosafety.

PubMed Central

Sewell, D L

1995-01-01

An estimated 500,000 laboratory workers in the United States are at risk of exposure to infectious agents that cause disease ranging from inapparent to life-threatening infections, but the precise risk to a given worker unknown. The emergence of human immunodeficiency virus and hantavirus, the continuing problem of hepatitis B virus, and the reemergence of Mycobacterium tuberculosis have renewed interest in biosafety for the employees of laboratories and health care facilities. This review examines the history, the causes, and the methods for prevention of laboratory-associated infections. The initial step in a biosafety program is the assessment of risk to the employee. Risk assessment guidelines include the pathogenicity of the infectious agent, the method of transmission, worker-related risk factors, the source and route of infection, and the design of the laboratory facility. Strategies for the prevention and management of laboratory-associated infections are based on the containment of the infectious agent by physical separation from the laboratory worker and the environment, employee education about the occupational risks, and availability of an employee health program. Adherence to the biosafety guidelines mandated or proposed by various governmental and accrediting agencies reduces the risk of an occupational exposure to infectious agents handled in the workplace. PMID:7553572

Identification of small molecule lead compounds for visceral leishmaniasis using a novel ex vivo splenic explant model system.

PubMed

Osorio, Yaneth; Travi, Bruno L; Renslo, Adam R; Peniche, Alex G; Melby, Peter C

2011-02-15

New drugs are needed to treat visceral leishmaniasis (VL) because the current therapies are toxic, expensive, and parasite resistance may weaken drug efficacy. We established a novel ex vivo splenic explant culture system from hamsters infected with luciferase-transfected Leishmania donovani to screen chemical compounds for anti-leishmanial activity. THIS MODEL HAS ADVANTAGES OVER IN VITRO SYSTEMS IN THAT IT: 1) includes the whole cellular population involved in the host-parasite interaction; 2) is initiated at a stage of infection when the immunosuppressive mechanisms that lead to progressive VL are evident; 3) involves the intracellular form of Leishmania; 4) supports parasite replication that can be easily quantified by detection of parasite-expressed luciferase; 5) is adaptable to a high-throughput screening format; and 6) can be used to identify compounds that have both direct and indirect anti-parasitic activity. The assay showed excellent discrimination between positive (amphotericin B) and negative (vehicle) controls with a Z' Factor >0.8. A duplicate screen of 4 chemical libraries containing 4,035 compounds identified 202 hits (5.0%) with a Z score of <-1.96 (p<0.05). Eighty-four (2.1%) of the hits were classified as lead compounds based on the in vitro therapeutic index (ratio of the compound concentration causing 50% cytotoxicity in the HepG(2) cell line to the concentration that caused 50% reduction in the parasite load). Sixty-nine (82%) of the lead compounds were previously unknown to have anti-leishmanial activity. The most frequently identified lead compounds were classified as quinoline-containing compounds (14%), alkaloids (10%), aromatics (11%), terpenes (8%), phenothiazines (7%) and furans (5%). The ex vivo splenic explant model provides a powerful approach to identify new compounds active against L. donovani within the pathophysiologic environment of the infected spleen. Further in vivo evaluation and chemical optimization of these lead

Screening for abnormal vaginal microflora by self-assessed vaginal pH does not enable detection of sexually transmitted infections in Ugandan women.

PubMed

Donders, Gilbert G G; Donders, Francesca; Bellen, Gert; Depuydt, Christophe; Eggermont, Natalie; Michiels, Thirsa; Lule, John; Byamughisa, Jacobat

2016-06-01

Is self-assessed vaginal pH measurement to detect abnormal vaginal bacterial microflora (AVF) an adequate prescreening method for detection of genital sexually transmitted infections (STIs)? A total of 360 Ugandan women tested themselves with a gloved finger and a pH color strip. PCR for bacterial vaginosis (BV)-associated bacteria was tested by PCR for Mycoplasma hominis, Ureaplasma urealyticum, and/or Atopobium vaginae, while the STIs were diagnosed by positive PCR for Chlamydia trachomatis, Neisseria gonorrhoeae, Mycoplasma genitalium, and/or Trichomonas vaginalis. A strong correlation was found between self-assessed pH values and BV-associated bacteria (P<0.0001), but not with STIs, not as single infections, nor in general. Self-measured vaginal pH correlated well with markers of high-risk microflora types such as BV or aerobic vaginitis, but not with STIs. Hence, in a screening program addressing AVF in low-resource countries, extra specific tests are required to exclude STIs. Copyright © 2015 Elsevier Inc. All rights reserved.

Coiling Phagocytosis of Trypanosomatids and Fungal Cells

PubMed Central

Rittig, M. G.; Schröppel, K.; Seack, K.-H.; Sander, U.; N’Diaye, E.-N.; Maridonneau-Parini, I.; Solbach, W.; Bogdan, C.

1998-01-01

Coiling phagocytosis has previously been studied only with the bacteria Legionella pneumophila and Borrelia burgdorferi, and the results were inconsistent. To learn more about this unconventional phagocytic mechanism, the uptake of various eukaryotic microorganisms by human monocytes, murine macrophages, and murine dendritic cells was investigated in vitro by video and electron microscopy. Unconventional phagocytosis of Leishmania spp. promastigotes, Trypanosoma cruzi trypomastigotes, Candida albicans hyphae, and zymosan particles from Saccharomyces cerevisiae differed in (i) morphology (rotating unilateral pseudopods with the trypanosomatids, overlapping bilateral pseudopods with the fungi), (ii) frequency (high with Leishmania; occasional with the fungi; rare with T. cruzi), (iii) duration (rapid with zymosan; moderate with the trypanosomatids; slow with C. albicans), (iv) localization along the promastigotes (flagellum of Leishmania major and L. aethiopica; flagellum or posterior pole of L. donovani), and (v) dependence on complement (strong with L. major and L. donovani; moderate with the fungi; none with L. aethiopica). All of these various types of unconventional phagocytosis gave rise to similar pseudopod stacks which eventually transformed to a regular phagosome. Further video microscopic studies with L. major provided evidence for a cytosolic localization, synchronized replication, and exocytic release of the parasites, extending traditional concepts about leishmanial infection of host cells. It is concluded that coiling phagocytosis comprises phenotypically similar consequences of various disturbances in conventional phagocytosis rather than representing a single separate mechanism. PMID:9712785

Exposure to welding fumes and lower airway infection with Streptococcus pneumoniae.

PubMed

Suri, Reetika; Periselneris, Jimstan; Lanone, Sophie; Zeidler-Erdely, Patti C; Melton, Geoffrey; Palmer, Keith T; Andujar, Pascal; Antonini, James M; Cohignac, Vanessa; Erdely, Aaron; Jose, Ricardo J; Mudway, Ian; Brown, Jeremy; Grigg, Jonathan

2016-02-01

Welders are at increased risk of pneumococcal pneumonia. The mechanism for this association is not known. The capacity of pneumococci to adhere to and infect lower airway cells is mediated by host-expressed platelet-activating factor receptor (PAFR). We sought to assess the effect of mild steel welding fumes (MS-WF) on PAFR-dependent pneumococcal adhesion and infection to human airway cells in vitro and on pneumococcal airway infection in a mouse model. The oxidative potential of MS-WF was assessed by their capacity to reduce antioxidants in vitro. Pneumococcal adhesion and infection of A549, BEAS-2B, and primary human bronchial airway cells were assessed by means of quantitative bacterial culture and expressed as colony-forming units (CFU). After intranasal instillation of MS-WF, mice were infected with Streptococcus pneumoniae, and bronchoalveolar lavage fluid (BALF) and lung CFU values were determined. PAFR protein levels were assessed by using immunofluorescence and immunohistochemistry, and PAFR mRNA expression was assessed by using quantitative PCR. PAFR was blocked by CV-3988, and oxidative stress was attenuated by N-acetylcysteine. MS-WF exhibited high oxidative potential. In A549 and BEAS-2B cells MS-WF increased pneumococcal adhesion and infection and PAFR protein expression. Both CV-3988 and N-acetylcysteine reduced MS-WF-stimulated pneumococcal adhesion and infection of airway cells. MS-WF increased mouse lung PAFR mRNA expression and increased BALF and lung pneumococcal CFU values. In MS-WF-exposed mice CV-3988 reduced BALF CFU values. Hypersusceptibility of welders to pneumococcal pneumonia is in part mediated by the capacity of welding fumes to increase PAFR-dependent pneumococcal adhesion and infection of lower airway cells. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. All rights reserved.

Exposure to welding fumes and lower airway infection with Streptococcus pneumoniae

PubMed Central

Suri, Reetika; Periselneris, Jimstan; Lanone, Sophie; Zeidler-Erdely, Patti C.; Melton, Geoffrey; Palmer, Keith T.; Andujar, Pascal; Antonini, James M.; Cohignac, Vanessa; Erdely, Aaron; Jose, Ricardo J.; Mudway, Ian; Brown, Jeremy; Grigg, Jonathan

2015-01-01

Background Welders are at increased risk of pneumococcal pneumonia. The mechanism for this association is not known. The capacity of pneumococci to adhere to and infect lower airway cells is mediated by host-expressed platelet-activating factor receptor (PAFR). Objective We sought to assess the effect of mild steel welding fumes (MS-WF) on PAFR-dependent pneumococcal adhesion and infection to human airway cells in vitro and on pneumococcal airway infection in a mouse model. Methods The oxidative potential of MS-WF was assessed by their capacity to reduce antioxidants in vitro. Pneumococcal adhesion and infection of A549, BEAS-2B, and primary human bronchial airway cells were assessed by means of quantitative bacterial culture and expressed as colony-forming units (CFU). After intranasal instillation of MS-WF, mice were infected with Streptococcus pneumoniae, and bronchoalveolar lavage fluid (BALF) and lung CFU values were determined. PAFR protein levels were assessed by using immunofluorescence and immunohistochemistry, and PAFR mRNA expression was assessed by using quantitative PCR. PAFR was blocked by CV-3988, and oxidative stress was attenuated by N-acetylcysteine. Results: MS-WF exhibited high oxidative potential. In A549 and BEAS-2B cells MS-WF increased pneumococcal adhesion and infection and PAFR protein expression. Both CV-3988 and N-acetylcysteine reduced MS-WF–stimulated pneumococcal adhesion and infection of airway cells. MS-WF increased mouse lung PAFR mRNA expression and increased BALF and lung pneumococcal CFU values. In MS-WF–exposed mice CV-3988 reduced BALF CFU values. Conclusions Hypersusceptibility of welders to pneumococcal pneumonia is in part mediated by the capacity of welding fumes to increase PAFR-dependent pneumococcal adhesion and infection of lower airway cells. PMID:26277596

Cytomegalovirus infection in HIV-infected versus non-infected infants and HIV disease progression in Cytomegalovirus infected versus non infected infants early treated with cART in the ANRS 12140-Pediacam study in Cameroon.

PubMed

Kfutwah, Anfumbom K W; Ngoupo, Paul Alain T; Sofeu, Casimir Ledoux; Ndongo, Francis Ateba; Guemkam, Georgette; Ndiang, Suzie Tetang; Owona, Félicité; Penda, Ida Calixte; Tchendjou, Patrice; Rouzioux, Christine; Warszawski, Josiane; Faye, Albert; Tejiokem, Mathurin Cyrille

2017-03-23

The outcome of CMV/HIV co-infection in infants treated early with combined antiretroviral therapy (cART) in resource-limited settings has not been described. We aimed to estimate the prevalence and identify factors associated with early CMV infection in HIV-infected and non-infected infants included in a study in Cameroon, and to compare HIV disease progression and survival after 1 year of early cART, following infants' CMV status. HIV-infected infants followed from birth or from HIV diagnosis before 7 months old and HIV-uninfected infants born to HIV-infected or uninfected mothers were tested for CMV at a median age of 4.0 months [Interquartile range (IQR): 3.4-4.9]. Multivariable logistic regression was performed to identify factors associated with CMV infection. Early cART was offered to HIV-infected infants: mortality, immunological and virological outcomes were assessed. Three hundred and sixty-nine infants were tested. The proportion of infants infected with CMV at baseline was significantly higher in HIV-infected than in HIV-uninfected groups (58.9% (86/146) vs 30.0% (67/223), p < 0.001). At baseline, median CMV viral load was higher in HIV-infected (3.7 log copies/ml [IQR; 3.1-4.3]) than in HIV-uninfected infants (2.8 log copies [IQR; 2.1-3.4], p < 0.001). cART was initiated in 90% of HIV-infected infants (132/146) at a median age of 4.0 months (IQR; 3.2-5.9); in this sub-group CMV infection was independently associated with being followed from the time of HIV diagnosis rather than from birth (aOR = 3.1, 95%CI [1.2-8.0]), born to a non-single mother (aOR = 3.4[1.4-8.1]), and breastfeeding (aOR = 7.3 [2.7-19.4]). HIV-infected infants were retested after a median of 7.1 months [4.8-9.5]: CMV was undetectable in 37 of the 61 (60.7%) initially CMV-infected cases and became detectable in 8 of the 38 (21.1%) initially CMV-negative cases. After 1 year of cART, the probability of death (0.185 vs 0.203; p = 0.75), the proportion of

[A prognostic assessment of louse-borne typhus (Rickettsia prowazekii infection) in Russia].

PubMed

Onishchenko, G G; Lukin, E P; Syskova, T G

1997-01-01

From the 1950s to 1974 R.prowazekii infection was registered on the territory of Russia, mainly in the form of Brill's disease, represented by some individual cases in the focus of infection. In 0.25% of all of cases rickettsiosis was linked with group outbreaks of the family character (14 events), reflecting the epidemic form of the disease. From 1974 until the present time the correlation between the sources of infection and the infestation of the population with lice dropped below the critical level, ensuring the transmission of the infective agent among the susceptible human population. This led to the steady disappearance of rickettsiosis (a decrease in the number of rickettsiosis cases from several thousand in the 60s to less than 100 in 1991) due to natural demographic processes. After the disintegration of the USSR, the migration of the population from some regions, especially from those where military conflicts took place, did not affect this process. The return of the epidemic form of rickettsiosis in Russia is impossible.

Implication of vector characteristics of Phlebotomus argentipes in the kala-azar elimination programme in the Indian sub-continent.

PubMed

Chowdhury, Rajib; Kumar, Vijay; Mondal, Dinesh; Das, Murari Lal; Das, Pradeep; Dash, Aditya Prasad; Kroeger, Axel

2016-05-01

Visceral leishmaniasis (VL), also known as kala-azar in the Indian sub-continent (ISC), is a major public health concern in Bangladesh, India, and Nepal, where it is caused by Leishmania donovani transmitted by the sand fly Phlebotomus argentipes. Various ecological parameters including air temperature, rainfall, wind speed, relative humidity, soil moisture, pH, and organic carbon are known to influence the oviposition of female sand flies, as well as the survival and development of larvae. However, more detailed knowledge on vector behavior, such as biting times, breeding places, and preferred hosts are needed to design optimal evidence-based vector control interventions. In order to facilitate rational decisions regarding VL vector control, a systematic review was conducted to identify the prevailing practice and knowledge gaps in relation to vector bionomics and behavior. Search terms included 'sand fly bionomics', 'habitat', and 'visceral leishmaniasis/kala-azar vector control' using the Boolean operator AND to identify the country of interest, namely: Bangladesh, India, and Nepal. Both PubMed and Google search engines were used. Additional unpublished documents in the three countries were also analyzed. Information on the life cycle of VL vectors, their breeding behavior, infection rate with L. donovani, feeding behavior, and seasonal variation are useful for designing vector control operations. Unfortunately, none of the studies on the life cycle of P. argentipes was conducted in field settings of the ISC, so the publications from other locations had to be used for determining the duration of life cycle and development from egg to adult. However, information about breeding places, seasonal variation of vector densities, and 47 out of the selected 51 papers are available from the ISC and can be used for intelligent design of control operations. Vector control services should undertake routine insecticide resistance monitoring and adapt indoor residual spraying

Implication of vector characteristics of Phlebotomus argentipes in the kala-azar elimination programme in the Indian sub-continent

PubMed Central

Chowdhury, Rajib; Kumar, Vijay; Mondal, Dinesh; Das, Murari Lal; Das, Pradeep; Dash, Aditya Prasad

2016-01-01

Background Visceral leishmaniasis (VL), also known as kala-azar in the Indian sub-continent (ISC), is a major public health concern in Bangladesh, India, and Nepal, where it is caused by Leishmania donovani transmitted by the sand fly Phlebotomus argentipes. Various ecological parameters including air temperature, rainfall, wind speed, relative humidity, soil moisture, pH, and organic carbon are known to influence the oviposition of female sand flies, as well as the survival and development of larvae. However, more detailed knowledge on vector behavior, such as biting times, breeding places, and preferred hosts are needed to design optimal evidence-based vector control interventions. Methods In order to facilitate rational decisions regarding VL vector control, a systematic review was conducted to identify the prevailing practice and knowledge gaps in relation to vector bionomics and behavior. Search terms included ‘sand fly bionomics’, ‘habitat’, and ‘visceral leishmaniasis/kala-azar vector control’ using the Boolean operator AND to identify the country of interest, namely: Bangladesh, India, and Nepal. Both PubMed and Google search engines were used. Additional unpublished documents in the three countries were also analyzed. Results Information on the life cycle of VL vectors, their breeding behavior, infection rate with L. donovani, feeding behavior, and seasonal variation are useful for designing vector control operations. Unfortunately, none of the studies on the life cycle of P. argentipes was conducted in field settings of the ISC, so the publications from other locations had to be used for determining the duration of life cycle and development from egg to adult. However, information about breeding places, seasonal variation of vector densities, and 47 out of the selected 51 papers are available from the ISC and can be used for intelligent design of control operations. Conclusion Vector control services should undertake routine insecticide

Development and assessment of national performance indicators for infection prevention and control and antimicrobial stewardship in European long-term care facilities.

PubMed

Cookson, B; Mackenzie, D; Kafatos, G; Jans, B; Latour, K; Moro, M L; Ricchizzi, E; Van de Mortel, M; Suetens, C; Fabry, J

2013-09-01

Healthcare-associated infections in long-term care facilities (LTCFs) are of increasing importance. To develop consensus national performance indicators (NPIs) for infection control (ICPI) and antimicrobial stewardship (ASPI) in LTCFs, and assess the performance of 32 European countries against these NPIs. Previously established European standards were the basis for consensus and the same iterative approach with national representatives from the 32 countries. A World Health Organization scoring system recorded how close each country was to implementing each standard. The 42 agreed component indicators were grouped into six NPI categories: 'national programme', 'guidelines', 'expert advice', 'IC structure' (not present in the ASPI), 'surveillance' and 'composite'. 'Guidelines' scored the highest mean total possible score (60%, range 20-100%), followed by 'composite' (53%, range 30-100%), 'expert advice' (48%, range 20-100%), 'surveillance' (47%, range 20-83%), 'national programme' (42%, range 20-100%) and 'IC structure' (39%, range 20-100%). Although several scores were low, some countries were able to implement all NPIs, indicating that this was feasible. Most NPIs were very significantly related, indicating that they were considered to be important by the countries. 'Guidelines' and 'IC structure' were significantly related to European region (P ≤ 0.05). Accreditation/inspection was not evident in seven (22%) countries, nine (28%) countries had accreditation/inspection that included IC assessments, and seven (22%) countries had accreditation/inspection that included IC and antimicrobial stewardship assessments. Multi-variable analysis found that only the NPI and the ICPI 'expert advice' were associated with accreditation/inspection which included IC and antimicrobial stewardship. The identified gaps represent significant potential patient safety issues. The NPIs should serve as a basis for monitoring improvements over the coming years. Copyright © 2013 The

Autonomic symptoms following Zika virus infection.

PubMed

Rodríguez, Yhojan; Rojas, Manuel; Ramírez-Santana, Carolina; Acosta-Ampudia, Yeny; Monsalve, Diana M; Anaya, Juan-Manuel

2018-04-01

To determine if autonomic symptoms are associated with previous Zika virus infection. Case-control study including 35 patients with Zika virus infection without evidence of neurological disease and 105 controls. Symptoms of autonomic dysfunction were assessed with the composite autonomic symptom scale 31 (COMPASS-31). Patients with previous Zika virus infection had significantly higher COMPASS-31 score than controls regardless of age and sex (p = 0.007). The main drivers for the higher scores where orthostatic intolerance (p = 0.003), secretomotor (p = 0.04) and bladder symptoms (p < 0.001). Zika virus infection is associated with autonomic dysfunction. The mechanisms remain to be elucidated.

Improving infection control in general practice.

PubMed

Farrow, S C; Zeuner, D; Hall, C

1999-03-01

Infection control measures in the health care setting should protect patients and staff from cross-infection. The prevention of harm is an essential part of good medical practice and failure might result in professional misconduct proceedings by the General Medical Council (GMC) and prosecution under the Health and Safety at Work legislation, as well as civil liability. For a health authority, overall responsibility for public health includes arrangements for the control of communicable diseases and infection in hospital and the community (NHS Management Executive, 1993), a function usually led by the Consultant in Communicable Disease Control (CCDC). This paper describes one district's collaborative approach between public health and GPs to assess and improve local infection control standards.

Assessment of adrenal function by measurement of salivary steroids in response to corticotrophin in patients infected with human immunodeficiency virus.

PubMed

Cardoso, Estela; Persi, Gabriel; González, Natalia; Tumilasci, Omar; Arregger, Alejandro; Burgos, Myriam; Rodríguez, Viviana; Molina, Ana; Contreras, Liliana N

2007-04-01

Adrenal insufficiency has been reported among critically ill HIV-infected patients. This is the first study that attempts to detect subclinical hypoadrenal states in non-critical HIV patients through salivary steroids in response to intramuscular low-dose ACTH injection. We studied 21 ambulatory adult HIV-infected patients without specific clinical signs or symptoms of adrenal insufficiency. Normal salivary flow-rate and salivary alpha-amylase activity confirmed adequate salivary gland function. Salivary cortisol (SAF) and salivary aldosterone (SAL) were obtained at baseline and 30 min after the injection of 25 microg of ACTH in the deltoid muscle (LDT(s)). Assessment of salivary steroids after stimulation with 250 microg of intramuscular ACTH (HDT(s)) was performed on those who hyporesponded to LDT(s). Basal blood samples were drawn for steroids, renin and ACTH measurements. At baseline SAF and SAL correlated significantly (p=0.0001) with basal serum cortisol and aldosterone (r=0.70 and 0.91, respectively). Plasma ACTH and renin concentrations were within the normal range in all patients. Eight of the twenty-one HIV(+) patients were LDT(s) hyporesponders in either SAF (n:1) or SAL (n:7). LDT(s) repeated in six cases after a year reconfirmed the impairment of aldosterone secretion. LDT(s) hyporesponders had normal steroid responses to HDT(s). LDT(s) is a simple, safe, well-accepted and non-invasive approach to assess adrenal function in HIV-infected ambulatory patients. It revealed subnormal cortisol (5%) and aldosterone responses (33%) when HDT(s) results were normal.

Synthesis, 68Ga-Radiolabeling, and Preliminary In Vivo Assessment of a Depsipeptide-Derived Compound as a Potential PET/CT Infection Imaging Agent

PubMed Central

Mokaleng, Botshelo B.; Ebenhan, Thomas; Ramesh, Suhas; Govender, Thavendran; Kruger, Hendrik G.; Hazari, Puja P.; Mishra, Anil K.; Marjanovic-Painter, Biljana; Zeevaart, Jan R.; Sathekge, Mike M.

2015-01-01

Noninvasive imaging is a powerful tool for early diagnosis and monitoring of various disease processes, such as infections. An alarming shortage of infection-selective radiopharmaceuticals exists for overcoming the diagnostic limitations with unspecific tracers such as 67/68Ga-citrate or 18F-FDG. We report here TBIA101, an antimicrobial peptide derivative that was conjugated to DOTA and radiolabeled with 68Ga for a subsequent in vitro assessment and in vivo infection imaging using Escherichia coli-bearing mice by targeting bacterial lipopolysaccharides with PET/CT. Following DOTA-conjugation, the compound was verified for its cytotoxic and bacterial binding behaviour and compound stability, followed by 68Gallium-radiolabeling. µPET/CT using 68Ga-DOTA-TBIA101 was employed to detect muscular E. coli-infection in BALB/c mice, as warranted by the in vitro results. 68Ga-DOTA-TBIA101-PET detected E. coli-infected muscle tissue (SUV = 1.3–2.4) > noninfected thighs (P = 0.322) > forearm muscles (P = 0.092) > background (P = 0.021) in the same animal. Normalization of the infected thigh muscle to reference tissue showed a ratio of 3.0 ± 0.8 and a ratio of 2.3 ± 0.6 compared to the identical healthy tissue. The majority of the activity was cleared by renal excretion. The latter findings warrant further preclinical imaging studies of greater depth, as the DOTA-conjugation did not compromise the TBIA101's capacity as targeting vector. PMID:25699267

Gender-Based Screening for Chlamydial Infection and Divergent Infection Trends in Men and Women

PubMed Central

Rogers, Susan M.; Turner, Charles F.; Miller, William C.; Erbelding, Emily; Eggleston, Elizabeth; Tan, Sylvia; Roman, Anthony; Hobbs, Marcia; Chromy, James; Muvva, Ravikiran; Ganapathi, Laxminarayana

2014-01-01

Objectives To assess the potential impact of chlamydial screening policy that recommends routine screening of women but not men. Methods Population surveys of probability samples of Baltimore adults aged 18 to 35 years in 1997–1998 and 2006–2009 collected biospecimens to estimate trends in undiagnosed chlamydial infection. Survey estimates are compared to surveillance data on diagnosed chlamydial infections reported to the Health Department. Results Prevalence of undiagnosed chlamydial infection among men increased from 1.6% to 4.0%, but it declined from 4.3% to 3.1% among women (p = 0.028 for test of interaction). The annual (average) number of diagnosed infections was substantially higher among women than men in both time periods and increased among both men and women. Undiagnosed infection prevalence was substantially higher among black than non-black adults (4.0% vs 1.2%, p = 0.042 in 1997–98 and 5.5% vs 0.7%, p<0.001 in 2006–09). Conclusion Divergent trends in undiagnosed chlamydial infection by gender parallel divergent screening recommendations that encourage chlamydial testing for women but not for men. PMID:24586491

Asian Organization for Crohn's and Colitis and Asia Pacific Association of Gastroenterology consensus on tuberculosis infection in patients with inflammatory bowel disease receiving anti-tumor necrosis factor treatment. Part 1: risk assessment.

PubMed

Park, Dong Il; Hisamatsu, Tadakazu; Chen, Minhu; Ng, Siew Chien; Ooi, Choon Jin; Wei, Shu Chen; Banerjee, Rupa; Hilmi, Ida Normiha; Jeen, Yoon Tae; Han, Dong Soo; Kim, Hyo Jong; Ran, Zhihua; Wu, Kaichun; Qian, Jiaming; Hu, Pin-Jin; Matsuoka, Katsuyoshi; Andoh, Akira; Suzuki, Yasuo; Sugano, Kentaro; Watanabe, Mamoru; Hibi, Toshifumi; Puri, Amarender S; Yang, Suk-Kyun

2018-01-01

Because anti-tumor necrosis factor (anti-TNF) therapy has become increasingly popular in many Asian countries, the risk of developing active tuberculosis (TB) among anti-TNF users may raise serious health problems in this region. Thus, the Asian Organization for Crohn's and Colitis and the Asia Pacific Association of Gastroenterology have developed a set of consensus statements about risk assessment, detection and prevention of latent TB infection, and management of active TB infection in patients with inflammatory bowel disease (IBD) receiving anti-TNF treatment. Twenty-three consensus statements were initially drafted and then discussed by the committee members. The quality of evidence and the strength of recommendations were assessed by using the Grading of Recommendations Assessment, Development, and Evaluation methodology. Web-based consensus voting was performed by 211 IBD specialists from 9 Asian countries concerning each statement. A consensus statement was accepted if at least 75% of the participants agreed. Part 1 of the statements comprised 2 parts: risk of TB infection Recommendaduring anti-TNF therapy, and screening for TB infection prior to commencing anti-TNF therapy. These consensus statements will help clinicians optimize patient outcomes by reducing the morbidity and mortality related to TB infections in patients with IBD receiving anti-TNF treatment.

Asian Organization for Crohn's and Colitis and Asia Pacific Association of Gastroenterology consensus on tuberculosis infection in patients with inflammatory bowel disease receiving anti-tumor necrosis factor treatment. Part 1: risk assessment

PubMed Central

Park, Dong Il; Hisamatsu, Tadakazu; Chen, Minhu; Ng, Siew Chien; Ooi, Choon Jin; Wei, Shu Chen; Banerjee, Rupa; Hilmi, Ida Normiha; Jeen, Yoon Tae; Han, Dong Soo; Kim, Hyo Jong; Ran, Zhihua; Wu, Kaichun; Qian, Jiaming; Hu, Pin-Jin; Matsuoka, Katsuyoshi; Andoh, Akira; Suzuki, Yasuo; Sugano, Kentaro; Watanabe, Mamoru; Hibi, Toshifumi; Puri, Amarender S.

2018-01-01

Because anti-tumor necrosis factor (anti-TNF) therapy has become increasingly popular in many Asian countries, the risk of developing active tuberculosis (TB) among anti-TNF users may raise serious health problems in this region. Thus, the Asian Organization for Crohn's and Colitis and the Asia Pacific Association of Gastroenterology have developed a set of consensus statements about risk assessment, detection and prevention of latent TB infection, and management of active TB infection in patients with inflammatory bowel disease (IBD) receiving anti-TNF treatment. Twenty-three consensus statements were initially drafted and then discussed by the committee members. The quality of evidence and the strength of recommendations were assessed by using the Grading of Recommendations Assessment, Development, and Evaluation methodology. Web-based consensus voting was performed by 211 IBD specialists from 9 Asian countries concerning each statement. A consensus statement was accepted if at least 75% of the participants agreed. Part 1 of the statements comprised 2 parts: risk of TB infection Recommendaduring anti-TNF therapy, and screening for TB infection prior to commencing anti-TNF therapy. These consensus statements will help clinicians optimize patient outcomes by reducing the morbidity and mortality related to TB infections in patients with IBD receiving anti-TNF treatment. PMID:29422793

Development of a novel observer-reported outcome measure for the assessment of Respiratory Syncytial Virus (RSV) infection symptoms in pediatric clinical trials.

PubMed

Lewis, Sandy; DeMuro, Carla; Block, Stan L; Senders, Shelly; Wisman, Paul; Toback, Seth; Chien, Jason W; Williams, Valerie

2017-01-01

Respiratory syncytial virus (RSV) is a seasonal infection affecting most children by 2 years of age and the leading cause of lower respiratory tract infection requiring hospitalization in infants. Novel antiviral medications are in development to improve the clinical outcomes of RSV; however, no clinical outcome assessments (COAs) for RSV have been developed in alignment with the United States Food and Drug Administration patient-reported outcome guidance to assist in the evaluation of new therapies. To address this need, an observer-reported outcome (ObsRO) measure designed to assess observable RSV symptoms was created. The literature was reviewed to evaluate existing COAs and identify constructs of interest. Individual caregiver interviews elicited concepts that informed item development, and candidate items were subsequently evaluated in two rounds of cognitive testing. Separate cohorts of caregivers of RSV-infected nonhospitalized and hospitalized infants participated. Therapeutic-area experts provided input throughout the instrument development process. Caregivers of 39 children < 24 months old with RSV (31 nonhospitalized, 8 hospitalized) participated in in-depth, individual interviews during concept elicitation and cognitive debriefing, resulting in 21 concepts identified as potentially observable and relevant to young children with RSV. The item pool was reduced to 12 cardinal symptoms and behavior impacts reported to be directly observable by caregivers, with 10 daytime and 9 nighttime symptoms to capture diurnal variation in severity. The RSV Caregiver Diary assesses RSV symptom severity and change from the parent or caregiver perspective in a standardized manner to measure treatment benefit. Following psychometric evaluation and refinement, this tool is expected to be suitable for assisting in the clinical development of RSV therapeutics.

White matter deficits assessed by diffusion tensor imaging and cognitive dysfunction in psychostimulant users with comorbid human immunodeficiency virus infection.

PubMed

Tang, Victor M; Lang, Donna J; Giesbrecht, Chantelle J; Panenka, William J; Willi, Taylor; Procyshyn, Ric M; Vila-Rodriguez, Fidel; Jenkins, Willough; Lecomte, Tania; Boyda, Heidi N; Aleksic, Ana; MacEwan, G William; Honer, William G; Barr, Alasdair M

2015-09-30

Psychostimulant drug use is commonly associated with drug-related infection, including the human immunodeficiency virus (HIV). Both psychostimulant use and HIV infection are known to damage brain white matter and impair cognition. To date, no study has examined white matter integrity using magnetic resonance imaging (MRI) diffusion tensor imaging (DTI) in chronic psychostimulant users with comorbid HIV infection, and determined the relationship of white matter integrity to cognitive function. Twenty-one subjects (mean age 37.5 ± 9.0 years) with a history of heavy psychostimulant use and HIV infection (8.7 ± 4.3 years) and 22 matched controls were scanned on a 3T MRI. Fractional anisotropy (FA) values were calculated with DTI software. Four regions of interest were manually segmented, including the genu of the corpus callosum, left and right anterior limbs of the internal capsule, and the anterior commissure. Subjects also completed a neurocognitive battery and questionnaires about physical and mental health. The psychostimulant using, HIV positive group displayed decreased white matter integrity, with significantly lower FA values for all white matter tracts (p < 0.05). This group also exhibited decreased cognitive performance on tasks that assessed cognitive set-shifting, fine motor speed and verbal memory. FA values for the white matter tracts correlated with cognitive performance on many of the neurocognitive tests. White matter integrity was thus impaired in subjects with psychostimulant use and comorbid HIV infection, which predicted worsened cognitive performance on a range of tests. Further study on this medical comorbidity is required.

Early wound infection identification using the WIRE tool in community health care settings: An audit report.

PubMed

Siaw-Sakyi, Vincent

2017-12-01

Wound infection is proving to be a challenge for health care professionals. The associated complications and cost of wound infection is immense and can lead to death in extreme cases. Current management of wound infection is largely subjective and relies on the knowledge of the health care professional to identify and initiate treatment. In response, we have developed an infection prediction and assessment tool. The Wound Infection Risk-Assessment and Evaluation tool (WIRE) and its management strategy is a tool with the aim to bring objectivity to infection prediction, assessment and management. A local audit carried out indicated a high infection prediction rate. More work is being done to improve its effectiveness.

Immediate Antiretroviral Therapy Reduces Risk of Infection-Related Cancer During Early HIV Infection.

PubMed

Borges, Álvaro H; Neuhaus, Jacqueline; Babiker, Abdel G; Henry, Keith; Jain, Mamta K; Palfreeman, Adrian; Mugyenyi, Peter; Domingo, Pere; Hoffmann, Christian; Read, Tim R H; Pujari, Sanjay; Meulbroek, Michael; Johnson, Margaret; Wilkin, Timothy; Mitsuyasu, Ronald

2016-12-15

 In the Strategic Timing of Antiretroviral Treatment (START) study, immediate combination antiretroviral therapy (cART) initiation reduced cancer risk by 64%. We hypothesized that risk reduction was higher for infection-related cancer and determined by differences in CD4 cell counts and human immunodeficiency virus (HIV) RNA between the study arms.  Incident malignancies in START were categorized into infection-related and infection-unrelated cancer. We used Cox models to assess factors associated with both cancer categories. We used sequential adjustment for baseline covariates, cancer risk factors, and HIV-specific variables to investigate potential mediators of cancer risk reduction with immediate cART.  There were 14 cancers among persons randomized to immediate cART (6 infection-related and 8 infection-unrelated) and 39 cancers in the deferred arm (23 infection-related and 16 infection-unrelated); hazard ratios of immediate vs deferred cART initiation were 0.26 (95% confidence interval [CI], .11-.64) for infection-related and 0.49 (95% CI, .21-1.15) for infection-unrelated cancer. Independent predictors of infection-related cancer were older age, higher body mass index, low- to middle-income region, HIV RNA, and baseline CD8 cell count. Older age and baseline CD8 cell count were independent predictors of infection-unrelated cancer. Adjustment for latest HIV RNA level had little impact on the protective effect of immediate cART on infection-related cancer. Adjustment for latest HIV RNA level, but not for CD4 cell count or cancer risk factors, attenuated the effect of immediate cART on infection-unrelated cancer.  Immediate cART initiation significantly reduces risk of cancer. Although limited by small sample size, this benefit does not appear to be solely attributable to HIV RNA suppression and may be also mediated by other mechanisms. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights

Multiple Human Papillomavirus Infection Is Associated with High-Risk Infection in Male Genital Warts in Ulsan, Korea

PubMed Central

Moon, Kyung Hyun; Yang, Sung-Hak; Roh, Min Cheol; Lee, Sang Hoon; Kim, Je Won; Kim, In Kyu; Roh, Kyoung Ho

2016-01-01

Further understanding of male human papillomavirus (HPV) infection is necessary to prevent infection in men, as well as transmission to women. In our current study, we investigated patterns of HPV infection and genotype distributions in male genital warts using the Anyplex II HPV28 Detection kit. We reviewed the medical records of 80 male patients who presented to 5 neighborhood clinics in Ulsan, Korea, for the treatment of genital warts between April 2014 and January 2015. All patients underwent HPV genotyping. The prevalence and characteristics of HPV infection were analyzed, and the patterns of HPV infection according to age were assessed. Among the study patients, 13 (16.3%) were negative for HPV infection, 46 (57.3%) were infected with low-risk HPV, and 21 (26.3%) were infected with high-risk HPV. Patients with multiple HPV infection were more likely to have high-risk HPV infection (P = 0.001). The prevalence of HPV infection was much higher in samples obtained by tissue excision due to a definite lesion (P = 0.001). There were no differences in high-risk HPV infection (P = 0.459), multiple HPV infection (P = 0.185), and recurrence at diagnosis (P = 0.178) according to age. HPV-6 and HPV-11 were the most common type overall (39.7% and 13.8%, respectively). HPV-16 and HPV-18 were the most common high-risk infections (both 3.4%). HPV infection is not only commonly encountered in male genital warts, but is also accompanied by high-risk HPV and multiple infections. PMID:26955236

Multiple Human Papillomavirus Infection Is Associated with High-Risk Infection in Male Genital Warts in Ulsan, Korea.

PubMed

Kwon, Taekmin; Moon, Kyung Hyun; Yang, Sung-Hak; Roh, Min Cheol; Lee, Sang Hoon; Kim, Je Won; Kim, In Kyu; Roh, Kyoung Ho; Park, Sungchan

2016-03-01

Further understanding of male human papillomavirus (HPV) infection is necessary to prevent infection in men, as well as transmission to women. In our current study, we investigated patterns of HPV infection and genotype distributions in male genital warts using the Anyplex II HPV28 Detection kit. We reviewed the medical records of 80 male patients who presented to 5 neighborhood clinics in Ulsan, Korea, for the treatment of genital warts between April 2014 and January 2015. All patients underwent HPV genotyping. The prevalence and characteristics of HPV infection were analyzed, and the patterns of HPV infection according to age were assessed. Among the study patients, 13 (16.3%) were negative for HPV infection, 46 (57.3%) were infected with low-risk HPV, and 21 (26.3%) were infected with high-risk HPV. Patients with multiple HPV infection were more likely to have high-risk HPV infection (P = 0.001). The prevalence of HPV infection was much higher in samples obtained by tissue excision due to a definite lesion (P = 0.001). There were no differences in high-risk HPV infection (P = 0.459), multiple HPV infection (P = 0.185), and recurrence at diagnosis (P = 0.178) according to age. HPV-6 and HPV-11 were the most common type overall (39.7% and 13.8%, respectively). HPV-16 and HPV-18 were the most common high-risk infections (both 3.4%). HPV infection is not only commonly encountered in male genital warts, but is also accompanied by high-risk HPV and multiple infections.

Assessing the diversity, host-specificity and infection patterns of apicomplexan parasites in reptiles from Oman, Arabia.

PubMed

Maia, João P; Harris, D James; Carranza, Salvador; Goméz-Díaz, Elena

2016-11-01

Understanding the processes that shape parasite diversification, their distribution and abundance provides valuable information on the dynamics and evolution of disease. In this study, we assessed the diversity, distribution, host-specificity and infection patterns of apicomplexan parasites in amphibians and reptiles from Oman, Arabia. Using a quantitative PCR approach we detected three apicomplexan parasites (haemogregarines, lankesterellids and sarcocystids). A total of 13 haemogregarine haplotypes were identified, which fell into four main clades in a phylogenetic framework. Phylogenetic analysis of six new lankesterellid haplotypes revealed that these parasites were distinct from, but phylogenetically related to, known Lankesterella species and might represent new taxa. The percentage of infected hosts (prevalence) and the number of haemogregarines in the blood (parasitaemia) varied significantly between gecko species. We also found significant differences in parasitaemia between haemogregarine parasite lineages (defined by phylogenetic clustering of haplotypes), suggesting differences in host-parasite compatibility between these lineages. For Pristurus rupestris, we found significant differences in haemogregarine prevalence between geographical areas. Our results suggest that host ecology and host relatedness may influence haemogregarine distributions and, more generally, highlight the importance of screening wild hosts from remote regions to provide new insights into parasite diversity.

Tuberculosis Infection in Zambia: The Association with Relative Wealth

PubMed Central

Boccia, Delia; Hargreaves, James; Ayles, Helen; Fielding, Katherine; Simwinga, Musonda; Godfrey-Faussett, Peter

2013-01-01

This study aimed to assess the association between household socioeconomic position and tuberculosis (TB) infection in two communities of Zambia. For this purpose we implemented a cross-sectional investigation, nested within a larger case control study. Infection was assessed using Quantiferon-TB Gold. A socioeconomic position index was constructed through principal component analysis combining data on human resources, food availability, housing quality, and access to services and infrastructures. In this study, higher socioeconomic position, rather than lower, was associated with significantly higher risk of TB infection. None of the traditional risk factors for TB infection mediated this association, suggesting that in these two communities TB transmission may occur through exposure to as yet undefined risk factors that are associated with higher socioeconomic position. Although further studies are needed, these results suggest emerging new patterns of TB transmission and a role of socioeconomic position on the risk of TB infection opposite to that expected. PMID:19478266

Assessment of Aquaflor (c), copper sulfate and potassium permanganate for control of Aeromonas hydrophila and Flavobacterium columnare infection in sunshine bass, Morone chrysops female x Morone saxatilis male

USDA-ARS?s Scientific Manuscript database

Two experiments were conducted to assess different therapeutants against a mixed infection of Aeromonas hydrophila and Flavobacterium columnare in sunshine bass (SB) (Morone chrysops female x Morone saxatilis male). Experiment 1 assessed the efficacy of copper sulfate (CuSO4), florfenicol-medicated...

Mayaro Virus Infection in Amazonia: A Multimodel Inference Approach to Risk Factor Assessment

PubMed Central

de Paula, Vanessa S.; Figueiredo, Luiz T. M.; Braga, Wornei S. M.; Luz, Sérgio L. B.

2012-01-01

Background Arboviral diseases are major global public health threats. Yet, our understanding of infection risk factors is, with a few exceptions, considerably limited. A crucial shortcoming is the widespread use of analytical methods generally not suited for observational data – particularly null hypothesis-testing (NHT) and step-wise regression (SWR). Using Mayaro virus (MAYV) as a case study, here we compare information theory-based multimodel inference (MMI) with conventional analyses for arboviral infection risk factor assessment. Methodology/Principal Findings A cross-sectional survey of anti-MAYV antibodies revealed 44% prevalence (n = 270 subjects) in a central Amazon rural settlement. NHT suggested that residents of village-like household clusters and those using closed toilet/latrines were at higher risk, while living in non-village-like areas, using bednets, and owning fowl, pigs or dogs were protective. The “minimum adequate” SWR model retained only residence area and bednet use. Using MMI, we identified relevant covariates, quantified their relative importance, and estimated effect-sizes (β±SE) on which to base inference. Residence area (β Village = 2.93±0.41; β Upland = −0.56±0.33, β Riverbanks = −2.37±0.55) and bednet use (β = −0.95±0.28) were the most important factors, followed by crop-plot ownership (β = 0.39±0.22) and regular use of a closed toilet/latrine (β = 0.19±0.13); domestic animals had insignificant protective effects and were relatively unimportant. The SWR model ranked fifth among the 128 models in the final MMI set. Conclusions/Significance Our analyses illustrate how MMI can enhance inference on infection risk factors when compared with NHT or SWR. MMI indicates that forest crop-plot workers are likely exposed to typical MAYV cycles maintained by diurnal, forest dwelling vectors; however, MAYV might also be circulating in nocturnal, domestic-peridomestic cycles in village-like areas

99m Tc-tazobactam, a novel infection imaging agent: Radiosynthesis, quality control, biodistribution, and infection imaging studies.

PubMed

Rasheed, Rashid; Naqvi, Syed Ali Raza; Gillani, Syed Jawad Hussain; Zahoor, Ameer Fawad; Jielani, Asif; Saeed, Nidda

2017-05-15

The radiolabeled drug 99m Tc-tazobactam ( 99m Tc-TZB) was developed and assessed as an infection imaging agent in Pseudomonas aeruginosa and Salmonella enterica infection-induced animal models by comparing with inflammation induced animal models. Radiosynthesis of 99m Tc-TZB was assessed while changing ligand concentration, reducing agent concentration, pH, and reaction time while keeping radioactivity constant (~370 MBq). Percent labeling of the resulting complex was measured using paper chromatography and instant thin layer chromatography. The analysis of the 99m Tc-TZB complex indicated >95% labeling yield and electrophoresis revealed complex is neutral in nature. The biodistribution study also showed predominantly renal excretion; however liver, stomach, and intestine also showed slight tracer agent uptake. The agent significantly accumulated in Pseudomonas aeruginosa and Salmonella enterica infection induced tissues 3.58 ± 0.26% and 2.43 ± 0.42% respectively at 1 hour postinjection. The inflamed tissue failed to uptake noticeable activity at 1 hour time point. The scintigraphic study results were found in accordance with biodistribution pattern. On the basis of our preliminary results, the newly developed 99m Tc-TZB can be used to diagnose bacterial infection and to discriminate between infected and inflamed tissues. Copyright © 2017 John Wiley & Sons, Ltd.

Comparison of individual and pooled stool samples for the assessment of intensity of Schistosoma mansoni and soil-transmitted helminth infections using the Kato-Katz technique.

PubMed

Kure, Ashenafi; Mekonnen, Zeleke; Dana, Daniel; Bajiro, Mitiku; Ayana, Mio; Vercruysse, Jozef; Levecke, Bruno

2015-09-24

Our group has recently provided a proof-of-principle for the examination of pooled stool samples using McMaster technique as a strategy for the rapid assessment of intensity of soil-transmitted helminth infections (STH, Ascaris lumbricoides, Trichuris trichiura and hookworm). In the present study we evaluated this pooling strategy for the assessment of intensity of both STH and Schistosoma mansoni infections using the Kato-Katz technique. A cross-sectional survey was conducted in 360 children aged 5-18 years from six schools in Jimma Zone (southwest Ethiopia). We performed faecal egg counts (FECs) in both individual and pooled samples (pools sizes of 5, 10 and 20) to estimate the number of eggs per gram of stool (EPG) using the Kato-Katz technique. We also assessed the time to screen both individual and pooled samples. Except for hookworms, there was a significant correlation (correlation coefficient = 0.53-0.95) between the mean of individual FECs and the FECs of pooled samples for A. lumbricoides, T. trichiura and S. mansoni, regardless of the pool size. Mean FEC were 2,596 EPG, 125 EPG, 47 EPG, and 41 EPG for A. lumbricoides, T. trichiura, S. mansoni and hookworm, respectively. There was no significant difference in FECs between the examination of individual and pooled stool samples, except for hookworms. For this STH, pools of 10 resulted in a significant underestimation of infection intensity. The total time to obtain individual FECs was 65 h 5 min. For pooled FECs, this was 19 h 12 min for pools of 5, 14 h 39 min for pools of 10 and 12 h 42 min for pools of 20. The results indicate that pooling of stool sample holds also promise as a rapid assessment of infections intensity for STH and S. mansoni using the Kato-Katz technique. In this setting, the time in the laboratory was reduced by 70 % when pools of 5 instead of individual stool samples were screened.

Curcumin overcomes the inhibitory effect of nitric oxide on Leishmania.

PubMed

Chan, Marion Man-Ying; Adapala, Naga Suresh; Fong, Dunne

2005-04-01

Upon Leishmania infection, macrophages are activated to produce nitrogen and oxygen radicals simultaneously. It is well established that the infected host cells rely on nitric oxide (NO) as the major weapon against the intracellular parasite. In India where leishmaniasis is endemic, the spice turmeric is used prolifically in food and for insect bites. Curcumin, the active principle of turmeric, is a scavenger of NO. This report shows that curcumin protects promastigotes and amastigotes of the visceral species, Leishmania donovani, and promastigotes of the cutaneous species, L. major, against the actions of S-nitroso-N-acetyl-D,L-penicillamine (SNAP) and DETANONOate, which release NO, 3-morpholino-sydnonimine hydrochloride (SIN-1), which releases NO and superoxide, and peroxynitrite, which is formed from the reaction of NO with superoxide. Thus, curcumin, as an antioxidant, is capable of blocking the action of both NO and NO congeners on the Leishmania parasite.

Pathogenesis of Proteus mirabilis Infection

PubMed Central

Armbruster, Chelsie E.; Mobley, Harry L. T.; Pearson, Melanie M.

2017-01-01

Proteus mirabilis, a Gram-negative rod-shaped bacterium most noted for its swarming motility and urease activity, frequently causes catheter-associated urinary tract infections (CAUTI) that are often polymicrobial. These infections may be accompanied by urolithiasis, development of bladder or kidney stones due to alkalinization of urine from urease-catalyzed urea hydrolysis. Adherence of the bacterium to epithelial and catheter surfaces is mediated by 17 different fimbriae, most notably MR/P fimbriae. Repressors of motility are often encoded by these fimbrial operons. Motility is mediated by flagella encoded on a single contiguous 54 kb chromosomal sequence. On agar plates, P. mirabilis undergoes a morphological conversion to a filamentous swarmer cell expressing hundreds of flagella. When swarms from different strains meet, a line of demarcation, a “Dienes line”, develops due to the killing action of each strain’s type VI secretion system. During infection, histological damage is caused by cytotoxins including hemolysin and a variety of proteases, some autotransported. The pathogenesis of infection, including assessment of individual genes or global screens for virulence or fitness factors has been assessed in murine models of ascending UTI or CAUTI using both single-species and polymicrobial models. Global gene expression studies carried out in culture and in the murine model have revealed the unique metabolism of this bacterium. Vaccines, using MR/P fimbria and its adhesin, MrpH, have been shown to be efficacious in the murine model. A comprehensive review of factors associated with urinary tract infection is presented, encompassing both historical perspectives and current advances. PMID:29424333

HIITE: HIV-1 incidence and infection time estimator.

PubMed

Park, Sung Yong; Love, Tanzy M T; Kapoor, Shivankur; Lee, Ha Youn

2018-06-15

Around 2.1 million new HIV-1 infections were reported in 2015, alerting that the HIV-1 epidemic remains a significant global health challenge. Precise incidence assessment strengthens epidemic monitoring efforts and guides strategy optimization for prevention programs. Estimating the onset time of HIV-1 infection can facilitate optimal clinical management and identify key populations largely responsible for epidemic spread and thereby infer HIV-1 transmission chains. Our goal is to develop a genomic assay estimating the incidence and infection time in a single cross-sectional survey setting. We created a web-based platform, HIV-1 incidence and infection time estimator (HIITE), which processes envelope gene sequences using hierarchical clustering algorithms and informs the stage of infection, along with time since infection for incident cases. HIITE's performance was evaluated using 585 incident and 305 chronic specimens' envelope gene sequences collected from global cohorts including HIV-1 vaccine trial participants. HIITE precisely identified chronically infected individuals as being chronic with an error less than 1% and correctly classified 94% of recently infected individuals as being incident. Using a mixed-effect model, an incident specimen's time since infection was estimated from its single lineage diversity, showing 14% prediction error for time since infection. HIITE is the first algorithm to inform two key metrics from a single time point sequence sample. HIITE has the capacity for assessing not only population-level epidemic spread but also individual-level transmission events from a single survey, advancing HIV prevention and intervention programs. Web-based HIITE and source code of HIITE are available at http://www.hayounlee.org/software.html. Supplementary data are available at Bioinformatics online.

Assessment of the influence of direct tobacco smoke on infection and active TB management

PubMed Central

Jiménez-Fuentes, María Ángeles; Maldonado, José; Molina, Israel; González-Díaz, Yoel; Milà, Celia; García-García, Esther; Muriel, Beatriz; Villar-Hernández, Raquel; Laabei, Maisem; Gómez, Andromeda-Celeste; Godoy, Pere; de Souza-Galvão, Maria Luiza; Solano, Segismundo; Jiménez-Ruiz, Carlos A.

2017-01-01

Background Smoking is a risk factor for tuberculosis (TB) infection and disease progression. Tobacco smoking increases susceptibility to TB in a variety of ways, one of which is due to a reduction of the IFN-γ response. Consequently, an impaired immune response could affect performance of IFN-γ Release Assays (IGRAs). Objective In the present study, we assess the impact of direct tobacco smoking on radiological manifestations, sputum conversion and immune response to Mycobacterium tuberculosis, analyzing IFN-γ secretion by IGRAs. Methods A total of 525 participants were studied: (i) 175 active pulmonary TB patients and (ii) 350 individuals coming from contact tracing studies, 41 of whom were secondary TB cases. Clinical, radiological and microbiological data were collected. T-SPOT.TB and QFN-G-IT were processed according manufacturer’s instructions. Results In smoking patients with active TB, QFN-G-IT (34.4%) and T-SPOT.TB (19.5%) had high frequencies of negative results. In addition, by means of an unconditional logistic regression, smoking was a main factor associated with IGRAs’ false-negative results (aOR: 3.35; 95%CI:1.47–7.61; p<0.05). Smoking patients with active TB presented a high probability of having cavitary lesions (aOR: 1.88; 95%CI:1.02–3.46;p<0.05). Mean culture negativization (months) ± standard deviation (SD) was higher in smokers than in non-smokers (2.47±1.3 versus 1.69±1.4). Latent TB infection (LTBI) was favored in smoking contacts, being a risk factor associated with infection (aOR: 11.57; 95%CI:5.97–22.41; p<0.00005). The IFN-γ response was significantly higher in non-smokers than in smokers. Smoking quantity and IFN-γ response analyzed by IGRAs were dose-dependent related. Conclusions Smoking had a negative effect on radiological manifestations, delaying time of sputum conversion. Our data establish a link between tobacco smoking and TB due to a weakened IFN-γ response caused by direct tobacco smoke. PMID:28837570

Assessment of the influence of direct tobacco smoke on infection and active TB management.

PubMed

Altet, Neus; Latorre, Irene; Jiménez-Fuentes, María Ángeles; Maldonado, José; Molina, Israel; González-Díaz, Yoel; Milà, Celia; García-García, Esther; Muriel, Beatriz; Villar-Hernández, Raquel; Laabei, Maisem; Gómez, Andromeda-Celeste; Godoy, Pere; de Souza-Galvão, Maria Luiza; Solano, Segismundo; Jiménez-Ruiz, Carlos A; Domínguez, Jose

2017-01-01

Smoking is a risk factor for tuberculosis (TB) infection and disease progression. Tobacco smoking increases susceptibility to TB in a variety of ways, one of which is due to a reduction of the IFN-γ response. Consequently, an impaired immune response could affect performance of IFN-γ Release Assays (IGRAs). In the present study, we assess the impact of direct tobacco smoking on radiological manifestations, sputum conversion and immune response to Mycobacterium tuberculosis, analyzing IFN-γ secretion by IGRAs. A total of 525 participants were studied: (i) 175 active pulmonary TB patients and (ii) 350 individuals coming from contact tracing studies, 41 of whom were secondary TB cases. Clinical, radiological and microbiological data were collected. T-SPOT.TB and QFN-G-IT were processed according manufacturer's instructions. In smoking patients with active TB, QFN-G-IT (34.4%) and T-SPOT.TB (19.5%) had high frequencies of negative results. In addition, by means of an unconditional logistic regression, smoking was a main factor associated with IGRAs' false-negative results (aOR: 3.35; 95%CI:1.47-7.61; p<0.05). Smoking patients with active TB presented a high probability of having cavitary lesions (aOR: 1.88; 95%CI:1.02-3.46;p<0.05). Mean culture negativization (months) ± standard deviation (SD) was higher in smokers than in non-smokers (2.47±1.3 versus 1.69±1.4). Latent TB infection (LTBI) was favored in smoking contacts, being a risk factor associated with infection (aOR: 11.57; 95%CI:5.97-22.41; p<0.00005). The IFN-γ response was significantly higher in non-smokers than in smokers. Smoking quantity and IFN-γ response analyzed by IGRAs were dose-dependent related. Smoking had a negative effect on radiological manifestations, delaying time of sputum conversion. Our data establish a link between tobacco smoking and TB due to a weakened IFN-γ response caused by direct tobacco smoke.

Use of Bibliometric Analysis to Assess the Scientific Productivity and Impact of the Global Emerging Infections Surveillance and Response System Program, 2006-2012.

PubMed

Reaves, Erik J; Valle, Ruben; Chandrasekera, Ruvani M; Soto, Giselle; Burke, Ronald L; Cummings, James F; Bausch, Daniel G; Kasper, Matthew R

2017-05-01

Scientific publication in academic literature is a key venue in which the U.S. Department of Defense's Global Emerging Infections Surveillance and Response System (GEIS) program disseminates infectious disease surveillance data. Bibliometric analyses are tools to evaluate scientific productivity and impact of published research, yet are not routinely used for disease surveillance. Our objective was to incorporate bibliometric indicators to measure scientific productivity and impact of GEIS-funded infectious disease surveillance, and assess their utility in the management of the GEIS surveillance program. Metrics on GEIS program scientific publications, project funding, and countries of collaborating institutions from project years 2006 to 2012 were abstracted from annual reports and program databases and organized by the six surveillance priority focus areas: respiratory infections, gastrointestinal infections, febrile and vector-borne infections, antimicrobial resistance, sexually transmitted infections, and capacity building and outbreak response. Scientific productivity was defined as the number of scientific publications in peer-reviewed literature derived from GEIS-funded projects. Impact was defined as the number of citations of a GEIS-funded publication by other peer-reviewed publications, and the Thomson Reuters 2-year journal impact factor. Indicators were retrieved from the Web of Science and Journal Citation Report. To determine the global network of international collaborations between GEIS partners, countries were organized by the locations of collaborating institutions. Between 2006 and 2012, GEIS distributed approximately US $330 million to support 921 total projects. On average, GEIS funded 132 projects (range 96-160) with $47 million (range $43 million-$53 million), annually. The predominant surveillance focus areas were respiratory infections with 317 (34.4%) projects and $225 million, and febrile and vector-borne infections with 274 (29

Assessment of Domestic Goats as Models for Experimental and Natural Infection with the North American Isolate of Rickettsia slovaca.

PubMed

Lukovsky-Akhsanov, Nicole; Keating, M Kelly; Spivey, Pamela; Lathrop, George W; Powell, Nathaniel; Levin, Michael L

2016-01-01

Rickettsia slovaca is a tick-borne human pathogen that is associated with scalp eschars and neck lymphadenopathy known as tick-borne lymphadenopathy (TIBOLA) or Dermacentor-borne necrosis erythema and lymphadenopathy (DEBONEL). Originally, R. slovaca was described in Eastern Europe, but since recognition of its pathogenicity, human cases have been reported throughout Europe. European vertebrate reservoirs of R. slovaca remain unknown, but feral swine and domestic goats have been found infected or seropositive for this pathogen. Recently, a rickettsial pathogen identical to R. slovaca was identified in, and isolated from, the American dog tick, Dermacentor variabilis. In previous experimental studies, this organism was found infectious to guinea pigs and transovarially transmissible in ticks. In this study, domestic goats (Capra hircus) were experimentally inoculated with the North American isolate of this R. slovaca-like agent to assess their reservoir competence-the ability to acquire the pathogens and maintain transmission between infected and uninfected ticks. Goats were susceptible to infection as demonstrated by detection of the pathogen in skin biopsies and multiple internal tissues, but the only clinical sign of illness was transient fever noted in three out of four goats, and reactive lymphoid hyperplasia. On average, less than 5% of uninfected ticks acquired the pathogen while feeding upon infected goats. Although domestic goats are susceptible to the newly described North American isolate of R. slovaca, they are likely to play a minor role in the natural transmission cycle of this pathogen. Our results suggest that goats do not propagate the North American isolate of R. slovaca in peridomestic environments and clinical diagnosis of infection could be difficult due to the brevity and mildness of clinical signs. Further research is needed to elucidate the natural transmission cycle of R. slovaca both in Europe and North America, as well as to identify a

Assessment of cytomegalovirus and cell-mediated immunity for predicting outcomes in non-HIV-infected patients with Pneumocystis jirovecii pneumonia.

PubMed

Kim, Taeeun; Park, Se Yoon; Lee, Hyun-Jung; Kim, Sun-Mi; Sung, Heungsup; Chong, Yong Pil; Lee, Sang-Oh; Choi, Sang-Ho; Kim, Yang Soo; Woo, Jun Hee; Kim, Sung-Han

2017-07-01

The clinical importance of pulmonary cytomegalovirus (CMV) co-infection in patients with Pneumocystis jirovecii pneumonia (PCP) is uncertain. We therefore determined the association of CMV infection with outcomes in non-HIV-infected patients with PCP by assessing CMV viral load and CMV-specific T-cell response.We prospectively enrolled all non-HIV-infected patients with confirmed PCP, over a 2-year period. Real-time polymerase chain reaction from bronchoalveolar lavage was performed to measure CMV viral load, and CMV enzyme-linked immunospot assays of peripheral blood were used to measure CMV-specific T-cell responses. The primary outcome was 30-day mortality.A total of 76 patients were finally analyzed. The mortality in patients with high BAL CMV viral load (>2.52 log copies/mL, 6/32 [18%]) showed a nonsignificant trend to be higher than in those with low CMV viral load (2/44 [5%], P = .13). However, the mortality in patients with low CMV-specific T-cell responses (<5 spots/2.0 × 10 PBMC, 6/29 [21%]) was significantly higher than in patients with high CMV-specific T-cell response (2/47 [4%], P = .048). Moreover, the 2 strata with high CMV viral load and low CMV-specific T-cell responses (4/14 [29%]) and low CMV viral load and low CMV-specific T-cell responses (2/15 [13%]) had poorer outcomes than the 2 strata with high CMV viral load and high CMV-specific T-cell responses (2/18 [11%]) and low CMV viral load and high CMV-specific T-cell responses (0/29 [0%]).These data suggest that the CMV replication and impaired CMV-specific T-cell responses adversely affect the outcomes in non-HIV-infected patients with PCP.

Coccinia grandis (L.) Voigt Leaf Extract Exhibits Antileishmanial Effect Through Pro-inflammatory Response: An In Vitro Study.

PubMed

Pramanik, Asmita; Paik, Dibyendu; Naskar, Kshudiram; Chakraborti, Tapati

2017-01-01

The conventional drugs used for the treatment of human visceral leishmaniasis have concerns about the toxicity and most importantly parasite resistance. To overcome these troubles, more efforts are made for the development of innovative therapeutic agents having effective antileishmanial activity and simultaneously stimulate adaptive immune system of host cells. Hence, search for new leishmanicidal from the natural origin like plants has shown its effectiveness for the treatment of this tropical disease. The aim of this study is to investigate and characterize the antileishmanial efficacy of Coccinia grandis (L.) Voigt leaf extract (Cg-Ex) with its immunomodulatory property against Leishmania donovani in an in vitro experimental model. Cg-Ex significantly reduces the intracellular L. donovani parasite load with IC 50  value 193 ± 0.78 µg/ml, but it has lower cytotoxicity on the murine RAW 264.7 macrophage cell line. Interestingly, Cg-Ex induces the generation of potent antimicrobials like reactive oxygen species and nitric oxide dose dependently in infected murine macrophages. Moreover, the increased production of Th1 cytokines (IL-12, TNF-α) with a concurrent decrease of Th2 cytokines (IL-10, TGF-β) was also observed in Cg-Ex-treated infected host macrophages. Our results thus confirm that serine protease inhibitor(s)-rich Cg-Ex exhibits antileishmanial activity in vitro, and this was mediated through the modulation of pro-inflammatory cytokines. On the whole, the present findings first demonstrate the antileishmanial property of Cg-Ex targeting the Leishmania serine protease resulting protection of host cells with Th1 cytokine expression. Thus, these data indicate that C. grandis leaf extract (Cg-Ex) might be considered as a new lead for designing alternative and novel natural therapeutic against visceral leishmaniasis.

Overview of systematic reviews assessing the evidence for shorter versus longer duration antibiotic treatment for bacterial infections in secondary care.

PubMed

Onakpoya, Igho J; Walker, A Sarah; Tan, Pui S; Spencer, Elizabeth A; Gbinigie, Oghenekome A; Cook, Johanna; Llewelyn, Martin J; Butler, Christopher C

2018-01-01

Our objective was to assess the clinical effectiveness of shorter versus longer duration antibiotics for treatment of bacterial infections in adults and children in secondary care settings, using the evidence from published systematic reviews. We conducted electronic searches in MEDLINE, Embase, Cochrane, and Cinahl. Our primary outcome was clinical resolution. The quality of included reviews was assessed using the AMSTAR criteria, and the quality of the evidence was rated using the GRADE criteria. We included 6 systematic reviews (n = 3,162). Four reviews were rated high quality, and two of moderate quality. In adults, there was no difference between shorter versus longer duration in clinical resolution rates for peritonitis (RR 1.03, 95% CI 0.98 to 1.09, I2 = 0%), ventilator-associated pneumonia (RR 0.93; 95% CI 0.81 to 1.08, I2 = 24%), or acute pyelonephritis and septic UTI (clinical failure: RR 1.00, 95% CI 0.46 to 2.18). The quality of the evidence was very low to moderate. In children, there was no difference in clinical resolution rates for pneumonia (RR 0.98, 95% CI 0.91 to 1.04, I2 = 48%), pyelonephritis (RR 0.95, 95% CI 0.88 to 1.04) and confirmed bacterial meningitis (RR 1.02, 95% CI 0.93 to 1.11, I2 = 0%). The quality of the evidence was low to moderate. In conclusion, there is currently a limited body of evidence to clearly assess the clinical benefits of shorter versus longer duration antibiotics in secondary care. High quality trials assessing strategies to shorten antibiotic treatment duration for bacterial infections in secondary care settings should now be a priority.

Overview of systematic reviews assessing the evidence for shorter versus longer duration antibiotic treatment for bacterial infections in secondary care

PubMed Central

Walker, A. Sarah; Tan, Pui S.; Spencer, Elizabeth A.; Gbinigie, Oghenekome A.; Cook, Johanna; Llewelyn, Martin J.; Butler, Christopher C.

2018-01-01

Our objective was to assess the clinical effectiveness of shorter versus longer duration antibiotics for treatment of bacterial infections in adults and children in secondary care settings, using the evidence from published systematic reviews. We conducted electronic searches in MEDLINE, Embase, Cochrane, and Cinahl. Our primary outcome was clinical resolution. The quality of included reviews was assessed using the AMSTAR criteria, and the quality of the evidence was rated using the GRADE criteria. We included 6 systematic reviews (n = 3,162). Four reviews were rated high quality, and two of moderate quality. In adults, there was no difference between shorter versus longer duration in clinical resolution rates for peritonitis (RR 1.03, 95% CI 0.98 to 1.09, I2 = 0%), ventilator-associated pneumonia (RR 0.93; 95% CI 0.81 to 1.08, I2 = 24%), or acute pyelonephritis and septic UTI (clinical failure: RR 1.00, 95% CI 0.46 to 2.18). The quality of the evidence was very low to moderate. In children, there was no difference in clinical resolution rates for pneumonia (RR 0.98, 95% CI 0.91 to 1.04, I2 = 48%), pyelonephritis (RR 0.95, 95% CI 0.88 to 1.04) and confirmed bacterial meningitis (RR 1.02, 95% CI 0.93 to 1.11, I2 = 0%). The quality of the evidence was low to moderate. In conclusion, there is currently a limited body of evidence to clearly assess the clinical benefits of shorter versus longer duration antibiotics in secondary care. High quality trials assessing strategies to shorten antibiotic treatment duration for bacterial infections in secondary care settings should now be a priority. PMID:29590188

2-Hexadecynoic acid inhibits plasmodial FAS-II enzymes and arrests erythrocytic and liver stage Plasmodium infections.

PubMed

Tasdemir, Deniz; Sanabria, David; Lauinger, Ina L; Tarun, Alice; Herman, Rob; Perozzo, Remo; Zloh, Mire; Kappe, Stefan H; Brun, Reto; Carballeira, Néstor M

2010-11-01

Acetylenic fatty acids are known to display several biological activities, but their antimalarial activity has remained unexplored. In this study, we synthesized the 2-, 5-, 6-, and 9-hexadecynoic acids (HDAs) and evaluated their in vitro activity against erythrocytic (blood) stages of Plasmodium falciparum and liver stages of Plasmodium yoelii infections. Since the type II fatty acid biosynthesis pathway (PfFAS-II) has recently been shown to be indispensable for liver stage malaria parasites, the inhibitory potential of the HDAs against multiple P. falciparum FAS-II (PfFAS-II) elongation enzymes was also evaluated. The highest antiplasmodial activity against blood stages of P. falciparum was displayed by 5-HDA (IC(50) value 6.6 μg/ml), whereas the 2-HDA was the only acid arresting the growth of liver stage P. yoelii infection, in both flow cytometric assay (IC(50) value 2-HDA 15.3 μg/ml, control drug atovaquone 2.5 ng/ml) and immunofluorescence analysis (IC(50) 2-HDA 4.88 μg/ml, control drug atovaquone 0.37 ng/ml). 2-HDA showed the best inhibitory activity against the PfFAS-II enzymes PfFabI and PfFabZ with IC(50) values of 0.38 and 0.58 μg/ml (IC(50) control drugs 14 and 30 ng/ml), respectively. Enzyme kinetics and molecular modeling studies revealed valuable insights into the binding mechanism of 2-HDA on the target enzymes. All HDAs showed in vitro activity against Trypanosoma brucei rhodesiense (IC(50) values 3.7-31.7 μg/ml), Trypanosoma cruzi (only 2-HDA, IC(50) 20.2 μg/ml), and Leishmania donovani (IC(50) values 4.1-13.4 μg/ml) with generally low or no significant toxicity on mammalian cells. This is the first study to indicate therapeutic potential of HDAs against various parasitic protozoa. It also points out that the malarial liver stage growth inhibitory effect of the 2-HDA may be promoted via PfFAS-II enzymes. The lack of cytotoxicity, lipophilic nature, and calculated pharmacokinetic properties suggests that 2-HDA could be a useful compound to

2-Hexadecynoic Acid Inhibits Plasmodial FAS-II Enzymes and Arrest Erythrocytic and Liver Stage Plasmodium Infections

PubMed Central

Tasdemir, Deniz; Sanabria, David; Lauinger, Ina L.; Tarun, Alice; Herman, Rob; Perozzo, Remo; Zloh, Mire; Kappe, Stefan H.; Brun, Reto; Carballeira, Néstor M.

2010-01-01

Acetylenic fatty acids are known to display several biological activities, but their antimalarial activity has remained unexplored. In this study, we synthesized the 2-, 5-, 6-, and 9-hexadecynoic acids (HDAs) and evaluated their in vitro activity against erythrocytic (blood) stages of Plasmodium falciparum and liver stages of P. yoelii infections. Since the type II fatty acid biosynthesis pathway (PfFAS-II) has recently been shown to be indispensable for liver stage malaria parasites, the inhibitory potential of the HDAs against multiple P. falciparum FAS-II (PfFAS-II) elongation enzymes was also evaluated. The highest antiplasmodial activity against blood stages of P. falciparum was displayed by 5-HDA (IC50 value 6.6. μg/ml), whereas the 2-HDA was the only acid arresting the growth of liver stage P. yoelii infection, in both flow cytometric assay (IC50 value 2-HDA 15.3 μg/ml, control drug atovaquone 2.5 ng/ml) and immunofluorescense analysis (IC50 2-HDA 4.88 μg/ml, control drug atovaquone 0.37 ng/ml). 2-HDA showed the best inhibitory against the PfFAS-II enzymes PfFabI and PfFabZ with IC50 values of 0.38 and 0.58 μg/ml (IC50 control drugs 14 and 30 ng/ml) respectively. Enzyme kinetics and molecular modeling studies revealed valuable insights into the binding mechanism of 2-HDA on the target enzymes. All HDAs showed in vitro activity against Trypanosoma brucei rhodesiense (IC50 values 3.7–31.7 μg/ml), Trypanosoma cruzi (only 2-HDA, IC50 20.2 μg/ml), and Leishmania donovani (IC50 values 4.1–13.4 μg/ml) with generally low or no significant toxicity on mammalian cells. This is the first study to indicate therapeutic potential of HDAs against various parasitic protozoa. It also points out that the malarial liver stage growth inhibitory effect of the 2-HDA may be promoted via PfFAS-II enzymes. The lack of cytotoxicity, lipophilic nature and calculated pharmacokinetic properties suggest that 2-HDA could be a useful compound to study the interaction of fatty

Cancer screening in patients infected with HIV.

PubMed

Sigel, Keith; Dubrow, Robert; Silverberg, Michael; Crothers, Kristina; Braithwaite, Scott; Justice, Amy

2011-09-01

Non-AIDS-defining cancers are a rising health concern among HIV-infected patients. Cancer screening is now an important component of health maintenance in HIV clinical practice. The decision to screen an HIV-infected patient for cancer should include an assessment of individualized risk for the particular cancer, life expectancy, and the harms and benefits associated with the screening test and its potential outcome. HIV-infected patients are at enhanced risk of several cancers compared to the general population; anal cancer, hepatocellular carcinoma, Hodgkin's lymphoma, and lung cancer all have good evidence demonstrating an enhanced risk in HIV-infected persons. A number of cancer screening interventions have shown benefit for specific cancers in the general population, but data on the application of these tests to HIV-infected persons are limited. Here we review the epidemiology and background literature relating to cancer screening interventions in HIV-infected persons. We then use these data to inform a conceptual model for evaluating HIV-infected patients for cancer screening.

How to Tackle Natural Focal Infections: From Risk Assessment to Vaccination Strategies.

PubMed

Busani, Luca; Platonov, Alexander E; Ergonul, Onder; Rezza, Giovanni

2017-01-01

Natural focal diseases are caused by biological agents associated with specific landscapes. The natural focus of such diseases is defined as any natural ecosystem containing the pathogen's population as an essential component. In such context, the agent circulates independently on human presence, and humans may become accidentally infected through contact with vectors or reservoirs. Some viruses (i.e., tick-borne encephalitis and Congo-Crimean hemorrhagic fever virus) are paradigmatic examples of natural focal diseases. When environmental changes, increase of reservoir/vector populations, demographic pressure, and/or changes in human behavior occur, increased risk of exposure to the pathogen may lead to clusters of cases or even to larger outbreaks. Intervention is often not highly cost-effective, thus only a few examples of large-scale or even targeted vaccination campaigns are reported in the international literature. To develop intervention models, risk assessment through disease mapping is an essential component of the response against these neglected threats and key to the design of prevention strategies, especially when effective vaccines against the disease are available.

Assessment of Chlamydia suis Infection in Pig Farmers.

PubMed

De Puysseleyr, L; De Puysseleyr, K; Braeckman, L; Morré, S A; Cox, E; Vanrompay, D

2017-06-01

Chlamydia suis infections are endemic in domestic pigs in Europe and can lead to conjunctivitis, pneumonia, enteritis and reproductive failure. Currently, the knowledge on the zoonotic potential of C. suis is limited. Moreover, the last decades, porcine tetracycline resistant C. suis strains have been isolated, which interfere with treatment of chlamydial infections. In this study, the presence of C. suis was examined on nine Belgian pig farms, using Chlamydia culture and a C. suis specific real-time PCR in both pigs and farmers. In addition to diagnosis for C. suis, the farmers' samples were examined using a Chlamydia trachomatis PCR. Additionally, the Chlamydia isolates were tested for the presence of the tet(C) resistance gene. C. DNA was demonstrated in pigs on all farms, and eight of nine farmers were positive in at least one anatomical site. None of the farmers tested positive for C. trachomatis. Chlamydia suis isolates were obtained from pigs of eight farms. Nine porcine C. suis isolates possessing a tet(C) gene were retrieved, originating from three farms. Moreover, C. suis isolates were identified in three human samples, including one pharyngeal and two rectal samples. These findings suggest further research on the zoonotic transfer of C. suis from pigs to humans is needed. © 2015 Blackwell Verlag GmbH.

Hepatitis B and C Virus Infections Among Human Immunodeficiency Virus-Infected People Who Inject Drugs in Lahore, Pakistan.

PubMed

Mansha, Sana; Imran, Muhammad; Shah, Amir Miraj Ul Hussain; Jamal, Muhsin; Ahmed, Fayyaz; Atif, Muhammad; Saleem, Muhammmad; Safi, Sher Zaman; Fatima, Zareen; Bilal Waqar, Ahmed

2017-06-01

Hepatitis B virus (HBV) and hepatitis C virus (HCV) are the major cause of the global burden of hepatitis. One of the main routes of transmission for both viruses is through exposure to infected blood, which includes sharing blood-contaminated syringes and needles. Human immunodeficiency virus (HIV) attacks the immune system and results in acquired immune deficiency syndrome and opportunistic infections. The objective of this study was to assess the epidemiology of HBV and HCV infections among HIV-infected people who inject drugs (PWID). The study enrolled 100 PWID from different addiction centers of the city of Lahore in Pakistan. All subjects were HIV-infected males and were above 16 years of age. Screening of HBV and HCV infections was performed through immunochromatography tests and enzyme-linked immunosorbent assays. The prevalence of HCV and HBV infections among the 100 HIV-infected PWID was 55% and 6%, respectively. HIV monoinfection was found in 37% of the subjects, while triple infection was detected in 2% of the subjects. Majority of the HIV-infected PWID were using heroin and Avil injections (65%). Half of the subjects had used injection drugs for 1-5 years, while 32% had used injection drugs for 6-10 years. HCV infection was more common than HBV infection among the enrolled subjects. Most of the PWID were practicing heroin and Avil injections.

Autophagic flux without a block differentiates varicella-zoster virus infection from herpes simplex virus infection.

PubMed

Buckingham, Erin M; Carpenter, John E; Jackson, Wallen; Zerboni, Leigh; Arvin, Ann M; Grose, Charles

2015-01-06

Autophagy is a process by which misfolded and damaged proteins are sequestered into autophagosomes, before degradation in and recycling from lysosomes. We have extensively studied the role of autophagy in varicella-zoster virus (VZV) infection, and have observed that vesicular cells are filled with >100 autophagosomes that are easily detectable after immunolabeling for the LC3 protein. To confirm our hypothesis that increased autophagosome formation was not secondary to a block, we examined all conditions of VZV infection as well as carrying out two assessments of autophagic flux. We first investigated autophagy in human skin xenografts in the severe combined immunodeficiency (SCID) mouse model of VZV pathogenesis, and observed that autophagosomes were abundant in infected human skin tissues. We next investigated autophagy following infection with sonically prepared cell-free virus in cultured cells. Under these conditions, autophagy was detected in a majority of infected cells, but was much less than that seen after an infected-cell inoculum. In other words, inoculation with lower-titered cell-free virus did not reflect the level of stress to the VZV-infected cell that was seen after inoculation of human skin in the SCID mouse model or monolayers with higher-titered infected cells. Finally, we investigated VZV-induced autophagic flux by two different methods (radiolabeling proteins and a dual-colored LC3 plasmid); both showed no evidence of a block in autophagy. Overall, therefore, autophagy within a VZV-infected cell was remarkably different from autophagy within an HSV-infected cell, whose genome contains two modifiers of autophagy, ICP34.5 and US11, not present in VZV.

Bacterial infection causes stress-induced memory dysfunction in mice.

PubMed

Gareau, Mélanie G; Wine, Eytan; Rodrigues, David M; Cho, Joon Ho; Whary, Mark T; Philpott, Dana J; Macqueen, Glenda; Sherman, Philip M

2011-03-01

The brain-gut axis is a key regulator of normal intestinal physiology; for example, psychological stress is linked to altered gut barrier function, development of food allergies and changes in behaviour. Whether intestinal events, such as enteric bacterial infections and bacterial colonisation, exert a reciprocal effect on stress-associated behaviour is not well established. To determine the effects of either acute enteric infection or absence of gut microbiota on behaviour, including anxiety and non-spatial memory formation. Behaviour was assessed following infection with the non-invasive enteric pathogen, Citrobacter rodentium in both C57BL/6 mice and germ-free Swiss-Webster mice, in the presence or absence of acute water avoidance stress. Whether daily treatment with probiotics normalised behaviour was assessed, and potential mechanisms of action evaluated. No behavioural abnormalities were observed, either at the height of infection (10 days) or following bacterial clearance (30 days), in C rodentium-infected C57BL/6 mice. When infected mice were exposed to acute stress, however, memory dysfunction was apparent after infection (10 days and 30 days). Memory dysfunction was prevented by daily treatment of infected mice with probiotics. Memory was impaired in germ-free mice, with or without exposure to stress, in contrast to conventionally reared, control Swiss-Webster mice with an intact intestinal microbiota. The intestinal microbiota influences the ability to form memory. Memory dysfunction occurs in infected mice exposed to acute stress, while in the germ-free setting memory is altered at baseline.

Asian Organization for Crohn's and Colitis and Asian Pacific Association of Gastroenterology consensus on tuberculosis infection in patients with inflammatory bowel disease receiving anti-tumor necrosis factor treatment. Part 1: Risk assessment.

PubMed

Park, Dong Ii; Hisamatsu, Tadakazu; Chen, Minhu; Ng, Siew Chien; Ooi, Choon Jin; Wei, Shu Chen; Banerjee, Rupa; Hilmi, Ida Normiha; Jeen, Yoon Tae; Han, Dong Soo; Kim, Hyo Jong; Ran, Zhihua; Wu, Kaichun; Qian, Jiaming; Hu, Pin-Jin; Matsuoka, Katsuyoshi; Andoh, Akira; Suzuki, Yasuo; Sugano, Kentaro; Watanabe, Mamoru; Hibi, Toshifumi; Puri, Amarender S; Yang, Suk-Kyun

2018-01-01

Because anti-tumor necrosis factor (anti-TNF) therapy has become increasingly popular in many Asian countries, the risk of developing active tuberculosis (TB) among anti-TNF users may raise serious health problems in this region. Thus, the Asian Organization for Crohn's and Colitis and the Asian Pacific Association of Gastroenterology have developed a set of consensus statements about risk assessment, detection, and prevention of latent TB infection and management of active TB infection in patients with inflammatory bowel disease (IBD) receiving anti-TNF treatment. Twenty-three consensus statements were initially drafted and then discussed by the committee members. The quality of evidence and the strength of recommendations were assessed by using the Grading of Recommendations Assessment, Development, and Evaluation methodology. Web-based consensus voting was performed by 211 IBD specialists from nine Asian countries concerning each statement. A consensus statement was accepted if at least 75% of the participants agreed. Part 1 of the statements comprised two parts: (i) risk of TB infection during anti-TNF therapy and (ii) screening for TB infection prior to commencing anti-TNF therapy. These consensus statements will help clinicians optimize patient outcomes by reducing the morbidity and mortality related to TB infections in patients with IBD receiving anti-TNF treatment. © 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

Role of calmodulin and calcineurin in regulating flagellar motility and wave polarity in Leishmania.

PubMed

Mukhopadhyay, Aakash Gautam; Dey, Chinmoy Sankar

2017-11-01

We have previously reported the involvement of cyclic AMP in regulating flagellar waveforms in Leishmania. Here, we investigated the roles of calcium, calmodulin, and calcineurin in flagellar motility regulation in L. donovani. Using high-speed videomicroscopy, we show that calcium-independent calmodulin and calcineurin activity is necessary for motility in Leishmania. Inhibition of calmodulin and calcineurin induced ciliary beats interrupting flagellar beating in both live (in vivo) and ATP-reactivated (in vitro) parasites. Our results indicate that signaling mediated by calmodulin and calcineurin operates antagonistically to cAMP signaling in regulating the waveforms of Leishmania flagellum. These two pathways are possibly involved in maintaining the balance between the two waveforms, essential for responding to environmental cues, survival, and infectivity.

Evolutionary genomics of epidemic visceral leishmaniasis in the Indian subcontinent.

PubMed

Imamura, Hideo; Downing, Tim; Van den Broeck, Frederik; Sanders, Mandy J; Rijal, Suman; Sundar, Shyam; Mannaert, An; Vanaerschot, Manu; Berg, Maya; De Muylder, Géraldine; Dumetz, Franck; Cuypers, Bart; Maes, Ilse; Domagalska, Malgorzata; Decuypere, Saskia; Rai, Keshav; Uranw, Surendra; Bhattarai, Narayan Raj; Khanal, Basudha; Prajapati, Vijay Kumar; Sharma, Smriti; Stark, Olivia; Schönian, Gabriele; De Koning, Harry P; Settimo, Luca; Vanhollebeke, Benoit; Roy, Syamal; Ostyn, Bart; Boelaert, Marleen; Maes, Louis; Berriman, Matthew; Dujardin, Jean-Claude; Cotton, James A

2016-03-22

Leishmania donovani causes visceral leishmaniasis (VL), the second most deadly vector-borne parasitic disease. A recent epidemic in the Indian subcontinent (ISC) caused up to 80% of global VL and over 30,000 deaths per year. Resistance against antimonial drugs has probably been a contributing factor in the persistence of this epidemic. Here we use whole genome sequences from 204 clinical isolates to track the evolution and epidemiology of L. donovani from the ISC. We identify independent radiations that have emerged since a bottleneck coincident with 1960s DDT spraying campaigns. A genetically distinct population frequently resistant to antimonials has a two base-pair insertion in the aquaglyceroporin gene LdAQP1 that prevents the transport of trivalent antimonials. We find evidence of genetic exchange between ISC populations, and show that the mutation in LdAQP1 has spread by recombination. Our results reveal the complexity of L. donovani evolution in the ISC in response to drug treatment.

Clinical outcomes of Torque teno virus-infected thalassemic patients with and without hepatitis C virus infection

PubMed Central

Alavi, Samin; Sharifi, Zohreh; Nourbakhsh, Kazem; Shamsian, Bibi Shahin; Arzanian, Mohammad Taghi; Safarisharari, Alieh; Navidinia, Masoumeh

2011-01-01

Background Although a marked proportion of thalassemic patients acquire Torque teno virus (TTV) through blood transfusion, its clinical importance is unclear. This study was designed to investigate the clinical importance of TTV infection in thalassemic patients with and without hepatitis C virus (HCV) co-infection in Iran. Methods In this case-control study, 107 thalassemic patients on chronic transfusion and 107 healthy individuals were selected. According to HCV and TTV infection status (detected by semi-nested PCR), patients were categorized into 4 groups: TTV and HCV negative, TTV positive, HCV positive, and TTV and HCV positive. Blood ferritin, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels in these 4 groups were assessed. Results Approximately half of the thalassemic patients (50.5%) and 27.1% of controls had TTV infection. Thalassemic patients had a greater chance of TTV infection compared to the control group with a sex-adjusted OR of 4.13 (95% CI=2.28-8.13). The increased levels of ALT, AST, and ferritin in the TTV and HCV-infected group were not significantly different from those in the TTV and HCV negative group. Co-infection with TTV and HCV did not significantly increase ALT, AST, and ferritin levels compared to infection with TTV alone. Conclusion Although common in thalassemic patients, TTV infection appears to have a negligible role in increasing the severity of liver disease, even when co-infection with HCV occurs. PMID:21747885

Canine Angiostrongylosis in Naturally Infected Dogs: Clinical Approach and Monitoring of Infection after Treatment

PubMed Central

Capogna, Antonio; Lia, Riccardo Paolo; Sasanelli, Mariateresa

2013-01-01

Canine angiostrongylosis is an increasingly reported disease in Europe which can be fatal if left untreated. The wide range of clinical presentation along with the absence of pathognomonic alterations can make the diagnosis challenging; thus any additional information that may provide clues to an early diagnosis may be of value, in order to ensure adequate anthelmintic treatment. Aim of the study was to assess a clinicopathological scoring system associated with natural Angiostrongylus vasorum infection diagnosed in canine patients during clinical practice, to clinically and paraclinically monitor infected dogs after treatment, and to monitor the presence of L1 larvae in faecal samples by Baermann's test. Of the total 210 enrolled animals A. vasorum infection was diagnosed in 7 dogs. These dogs were clinically and paraclinically investigated and monitored after specific treatment. Further 3 symptomatic dogs were retrospectively included in the monitoring. Results suggest that the computed scoring system can help to increase the clinical suspicion of infection particularly in asymptomatic dogs before the onset of potentially lethal lesions. Data of faecal monitoring suggested that treatment may control parasite burden but be unable to eradicate infection. Thus, a continued faecal monitoring after treatment is advisable for identification of still infected or reinfected dogs. PMID:24459443

Trichuris and hookworm infections associated with anaemia during pregnancy.

PubMed

Gyorkos, Theresa W; Gilbert, Nicolas L; Larocque, Renée; Casapía, Martín

2011-04-01

To assess the following associations between the second and third trimesters of pregnancy: (i) the intensity of soil-transmitted helminth (STH) infection and haemoglobin/anaemia, (ii) the effect of mebendazole treatment on the occurrence of STH infection, and (iii) the effect of mebendazole treatment on haemoglobin/anaemia. Data originated from a trial of 1042 pregnant women recruited in their second trimester and followed to delivery. Baseline assessments included socio-demographic/health information from questionnaires, haemoglobin/anaemia from HemoCue ascertainment of fingerprick blood, and the presence and intensity of STH (Ascaris lumbricoides, hookworms and Trichuris trichiura) infections from Kato-Katz examination. All women were given iron supplements; half were randomly allocated to receive single dose 500 mg mebendazole, and half, placebo. Haemoglobin/anaemia and STH infection status were determined again in the third trimester of pregnancy. Complete information was available from 935 (89.7%) women. Mebendazole significantly reduced the prevalence and intensity of all three STH infections. Higher intensities of hookworm and Trichuris infections in the second trimester were associated with a higher risk of anaemia in the third trimester. Overall, women with moderate/heavy Trichuris infection were found to be at a higher risk of anaemia; the highest risk was observed among those with moderate/heavy hookworm co-infection (adjusted OR = 2.77; 95% CI: 1.26, 6.11). Mebendazole treatment did not reduce the risk of anaemia. Higher intensities of both Trichuris and hookworm infections are associated with anaemia in pregnancy. The importance of Trichuris infections during pregnancy requires renewed attention. © 2011 Blackwell Publishing Ltd.

Tri-county comprehensive assessment of risk factors for sporadic reportable bacterial enteric infection in children

PubMed Central

Denno, Donna M.; Keene, William E.; Hutter, Carolyn M.; Koepsell, Jennifer K.; Patnode, Marianne; Flodin-Hursh, Denny; Stewart, Laurie K.; Duchin, Jeffrey S.; Rasmussen, Laurette; Jones, Robert; Tarr, Phillip I.

2009-01-01

Background. The aim of this study was to determine risk factors for childhood sporadic reportable enteric infection (REI) caused by bacteria, specifically Campylobacter, Salmonella, Escherichia coli O157, or Shigella (REI-B). Methods. Matched case-control study. Case patients aged <19 years who were reported to 3 Washington State county health departments and matched control subjects were interviewed from November 2003–November 2005. Matched odds ratios (ORs) were calculated by using conditional logistic regression. Population attributable risk percentages were calculated for exposures associated with infection. Results. Two hundred ninety-six case patients were matched to 580 control subjects. Aquatic recreation was the most important factor associated with all REI-Bs studied (beach water exposure [OR for Salmonella infection, 28.3 {CI, 7.2–112.2}; OR for Shigella infection, 14.5 {CI 1.5–141.0} or any recreational water exposure [OR for Campylobacter infection, 2.7 {CI, 1.5–4.8}; OR for Escherichia coli O157 infection, 7.4 {CI, 2.1–26.1}]). Suboptimal kitchen hygiene after preparation of raw meat or chicken (OR, 7.1 [CI, 2.1–24.1]) and consumption of food from restaurants were additional risks for Campylobacter infection. Infection with Salmonella was associated with the use of private wells as sources of drinking water (OR, 6.5 [CI, 1.4–29.7]), and the use of residential septic systems was a risk for both Salmonella (OR, 3.2 [CI, 1.3–7.8]) and E. coli (OR, 5.7 [CI, 1.2–27.2]) O157 infection. Conclusions. Overall, non-food exposures were as important as food-related exposures with regard to their contributions to the proportion of cases. Infection prevention efforts should address kitchen hygiene practices and non-food exposures, such as recreational water exposure, in addition to food-consumption risks. PMID:19281302

Assessing the residual risk for transfusion-transmitted infections in the Philippine blood supply.

PubMed

Lam, Hilton Y; Belizario, Vicente Y; Juban, Noel R; Alejandria, Marissa M; Castillo-Carandang, Nina; Arcellana-Nuqui, Elizabeth; Mirasol, Ma Angelina; Cordero, Cynthia P; Sison, Olivia T; Rivera, Adovich S

2014-09-01

Due to a USAID-funded study on blood banks, a national policy was instituted in 1994 that set standards for Philippine blood services, promoted voluntary donation, and led to a ban on commercial blood banks. In this follow-up study, we assess the safety of the supply by determining the residual risk for transfusion-transmitted infections (syphilis, hepatitis B and C, HIV). We also identified unsafe facility practices and generated policy recommendations. A 1992 study found that transfusion-ready blood was not safe using the LQAS method (P > 0.05). We found that the 2012 residual risk became 0 to 0.9 percent attributable to the national policy. We noted poor to fair adherence to this policy. We identified unsafe practices such as use of rapid tests and lack of random blood retesting. Training and use of regional networks may improve safety. Despite improvement in safety, facilities complain of funding and logistical issues regarding compliance with the policy.

Self-Reported Mental Health Predicts Acute Respiratory Infection.

PubMed

Maxwell, Lizzie; Barrett, Bruce; Chase, Joseph; Brown, Roger; Ewers, Tola

2015-06-01

Poor mental health conditions, including stress and depression, have been recognized as a risk factor for the development of acute respiratory infection. Very few studies have considered the role of general mental health in acute respiratory infection occurrence. The aim of this analysis is to determine if overall mental health, as assessed by the mental component of the Short Form 12 Health Survey, predicts incidence, duration, or severity of acute respiratory infection. Data utilized for this analysis came from the National Institute of Health-funded Meditation or Exercise for Preventing Acute Respiratory Infection (MEPARI) and MEPARI-2 randomized controlled trials examining the effects of meditation or exercise on acute respiratory infection among adults aged > 30 years in Madison, Wisconsin. A Kendall tau rank correlation compared the Short Form 12 mental component, completed by participants at baseline, with acute respiratory infection incidence, duration, and area-under-the-curve (global) severity, as assessed by the Wisconsin Upper Respiratory Symptom Survey. Participants were recruited from Madison, Wis, using advertisements in local media. Short Form 12 mental health scores significantly predicted incidence (P = 0.037) of acute respiratory infection, but not duration (P = 0.077) or severity (P = 0.073). The Positive and Negative Affect Schedule (PANAS) negative emotion measure significantly predicted global severity (P = 0.036), but not incidence (P = 0.081) or duration (P = 0.125). Mindful Attention Awareness Scale scores significantly predicted incidence of acute respiratory infection (P = 0.040), but not duration (P = 0.053) or severity (P = 0.70). The PHQ-9, PSS-10, and PANAS positive measures did not show significant predictive associations with any of the acute respiratory infection outcomes. Self-reported overall mental health, as measured by the mental component of Short Form 12, predicts acute respiratory infection incidence.

Guillain-Barré syndrome risk among individuals infected with Zika virus: a multi-country assessment.

PubMed

Mier-Y-Teran-Romero, Luis; Delorey, Mark J; Sejvar, James J; Johansson, Michael A

2018-05-15

Countries with ongoing outbreaks of Zika virus have observed a notable rise in reported cases of Guillain-Barré syndrome (GBS), with mounting evidence of a causal link between Zika virus infection and the neurological syndrome. However, the risk of GBS following a Zika virus infection is not well characterized. In this work, we used data from 11 locations with publicly available data to estimate the risk of GBS following an infection with Zika virus, as well as the location-specific incidence of infection and the number of suspect GBS cases reported per infection. We built a mathematical inference framework utilizing data from 11 locations that had reported suspect Zika and GBS cases, two with completed outbreaks prior to 2015 (French Polynesia and Yap) and nine others in the Americas covering partial outbreaks and where transmission was ongoing as of early 2017. We estimated that 2.0 (95% credible interval 0.5-4.5) reported GBS cases may occur per 10,000 Zika virus infections. The frequency of reported suspect Zika cases varied substantially and was highly uncertain, with a mean of 0.11 (95% credible interval 0.01-0.24) suspect cases reported per infection. These estimates can help efforts to prepare for the GBS cases that may occur during Zika epidemics and highlight the need to better understand the relationship between infection and the reported incidence of clinical disease.

Antibiotic prophylaxis adequacy in knee arthroplasty and surgical wound infection: Prospective cohort study.

PubMed

Del-Moral-Luque, J A; Checa-García, A; López-Hualda, Á; Villar-Del-Campo, M C; Martínez-Martín, J; Moreno-Coronas, F J; Montejo-Sancho, J; Rodríguez-Caravaca, G

Antibiotic prophylaxis is the most suitable tool for preventing surgical wound infection. This study evaluated adequacy of antibiotic prophylaxis in surgery for knee arthroplasty and its effect on surgical site infection. Prospective cohort study. We assessed the degree of adequacy of antibiotic prophylaxis, the causes of non-adequacy, and the effect of non-adequacy on surgical site infection. Incidence of surgical site infection was studied after a maximum incubation period of a year. To assess the effect of prophylaxis non-adequacy on surgical site infection we used the relative risk adjusted with the aid of a logistic regression model. The study covered a total of 1749 patients. Antibiotic prophylaxis was indicated in all patients and administered in 99.8% of cases, with an overall protocol adequacy of 77.6%. The principal cause of non-compliance was the duration of prescription of the antibiotics (46.5%). Cumulative incidence of surgical site infection was 1.43%. No relationship was found between prophylaxis adequacy and surgical infection (RR=1.15; 95% CI: .31-2.99) (P>.05). Surveillance and infection control programs enable risk factors of infection and improvement measures to be assessed. Monitoring infection rates enables us to reduce their incidence. Adequacy of antibiotic prophylaxis was high but could be improved. We did not find a relationship between prophylaxis adequacy and surgical site infection rate. Copyright © 2017 SECOT. Publicado por Elsevier España, S.L.U. All rights reserved.

Treatment of Periprosthetic Infections: An Economic Analysis

PubMed Central

Hernández-Vaquero, Daniel; Fernández-Fairen, Mariano; Torres, Ana; Menzie, Ann M.; Fernández-Carreira, José Manuel; Murcia-Mazon, Antonio; Merzthal, Luis

2013-01-01

This review summarizes the existing economic literature, assesses the value of current data, and presents procedures that are the less costly and more effective options for the treatment of periprosthetic infections of knee and hip. Optimizing antibiotic use in the prevention and treatment of periprosthetic infection, combined with systemic and behavioral changes in the operating room, the detection and treatment of high-risk patient groups, as well as the rational management of the existing infection by using the different procedures according to each particular case, could allow for improved outcomes and lead to the highest quality of life for patients and the lowest economic impact. Nevertheless, the costeffectiveness of different interventions to treat periprosthetic infections remains unclear. PMID:23781163

Measuring the quality of infection control in Dutch nursing homes using a standardized method; the Infection prevention RIsk Scan (IRIS)

PubMed Central

2014-01-01

Background We developed a standardised method to assess the quality of infection control in Dutch Nursing Home (NH), based on a cross-sectional survey that visualises the results. The method was called the Infection control RIsk Infection Scan (IRIS). We tested the applicability of this new tool in a multicentre surveillance executed June and July 2012. Methods The IRIS includes two patient outcome-variables, i.e. the prevalence of healthcare associated infections (HAI) and rectal carriage of Extended-Spectrum Beta-Lactamase (ESBL) producing Enterobacteriaceae (ESBL-E); two patient-related risk factors, i.e. use of medical devices, and antimicrobial therapy; and three ward-related risk factors, i.e. environmental contamination, availability of local guidelines, and shortcomings in infection prevention preconditions. Results were categorised as low-, intermediate- and high risk, presented in an easy-to-read graphic risk spider-plot. This plot was given as feedback to management and healthcare workers of the NH. Results Large differences were found among most the variables in the different NH. Common shortcomings were the availability of infection control guidelines and the level of environmental cleaning. Most striking differences were observed in the prevalence of ESBL carriage, ranged from zero to 20.6% (p < 0.001). Conclusions The IRIS provided a rapid and easy to understand assessment of the infection control situation of the participating NH. The results can be used to improve the quality of infection control based on the specific needs of a NH but needs further validation in future studies. Repeated measurement can determine the effectiveness of the interventions. This makes the IRIS a useful tool for quality systems. PMID:25243067

CQUIN audit for prescription of antibiotics for urinary tract infections in an acute medical assessment unit.

PubMed

Oppenheimer, Maylin; Rezwan, Nivin

2015-01-01

Urinary tract infections (UTI) are a common presentation in a medical assessment unit, and we wanted to check compliance with hospital guidelines for antibiotic prescribing in patients presenting to hospital with urinary tract infection. The guidelines are based on local organisms and sensitivities. A retrospective audit of 40 patient records with positive urine cultures from July to August 2013 showed that 20% of patients with culture confirmed UTI were not given antibiotics at all. Of those prescribed antibiotics, 25% were non-compliant with local policy, and nearly one in two patients received more than one antibiotic. Furthermore, stop dates were not stated on 77% of the drug charts and duration of treatment ranged from one to 11 days. Interventions were then introduced in the form of group teaching sessions, proactive checks by Trust pharmacists and widely distributed posters, and the same data sets collected for April to March 2014 to assess for efficacy of the interventions. On re-auditing, 35% patients were not prescribed any antibiotics. However, compliance with local policy was 100%, including 100% drug charts having a stop/review date stated. The overall duration of treatment now ranged from one to seven days, and fewer than one in four patients had more than one antibiotic. Our results showed that improvement was needed in antibiotic stewardship, in particular with regards to compliance with the local guidelines and documentation of prescription. We have demonstrated that it is possible to improve compliance through teaching, by displaying information prominently, and vigilance by the clinical team. The outcome of this is a decreased number and duration of antibiotics prescribed, which has benefits for the patients, the hospital, and the community as a whole. Further work would include interventions to improve the number of patients who are missing antibiotic prescriptions altogether.

Dose-response assessment for influenza A virus based on data sets of infection with its live attenuated reassortants.

PubMed

Watanabe, Toru; Bartrand, Timothy A; Omura, Tatsuo; Haas, Charles N

2012-03-01

Reported data sets on infection of volunteers challenged with wild-type influenza A virus at graded doses are few. Alternatively, we aimed at developing a dose-response assessment for this virus based on the data sets for its live attenuated reassortants. Eleven data sets for live attenuated reassortants that were fit to beta-Poisson and exponential dose-response models. Dose-response relationships for those reassortants were characterized by pooling analysis of the data sets with respect to virus subtype (H1N1 or H3N2), attenuation method (cold-adapted or avian-human gene reassortment), and human age (adults or children). Furthermore, by comparing the above data sets to a limited number of reported data sets for wild-type virus, we quantified the degree of attenuation of wild-type virus with gene reassortment and estimated its infectivity. As a result, dose-response relationships of all reassortants were best described by a beta-Poisson model. Virus subtype and human age were significant factors determining the dose-response relationship, whereas attenuation method affected only the relationship of H1N1 virus infection to adults. The data sets for H3N2 wild-type virus could be pooled with those for its reassortants on the assumption that the gene reassortment attenuates wild-type virus by at least 63 times and most likely 1,070 times. Considering this most likely degree of attenuation, 10% infectious dose of H3N2 wild-type virus for adults was estimated at 18 TCID50 (95% CI = 8.8-35 TCID50). The infectivity of wild-type H1N1 virus remains unknown as the data set pooling was unsuccessful. © 2011 Society for Risk Analysis.

Assessment of prion reduction filters in decreasing infectivity of ultracentrifuged 263K scrapie-infected brain homogenates in "spiked" human blood and red blood cells.

PubMed

Cardone, Franco; Sowemimo-Coker, Samuel; Abdel-Haq, Hanin; Sbriccoli, Marco; Graziano, Silvia; Valanzano, Angelina; Berardi, Vito Angelo; Galeno, Roberta; Puopolo, Maria; Pocchiari, Maurizio

2014-04-01

The safety of red blood cells (RBCs) is of concern because of the occurrence of four transfusion-transmitted variant Creutzfeldt-Jakob disease (vCJD) cases in the United Kingdom. The absence of validated screening tests requires the use of procedures to remove prions from blood to minimize the risk of transmission. These procedures must be validated using infectious prions in a form that is as close as possible to one in blood. Units of human whole blood (WB) and RBCs were spiked with high-speed supernatants of 263K scrapie-infected hamster brain homogenates. Spiked samples were leukoreduced and then passed through prion-removing filters (Pall Corporation). In another experiment, RBCs from 263K scrapie-infected hamsters were treated as above, and residual infectivity was measured by bioassay. The overall removal of infectivity by the filters from prion-spiked WB and RBCs was approximately two orders of magnitude. No infectivity was detected in filtered hamster RBCs endogenously infected with scrapie. The use of prion-removing filters may help to reduce the risk of transfusion-transmitted vCJD. To avoid overestimation of prion removal efficiency in validation studies, it may be more appropriate to use supernates from ultracentrifugation of scrapie-infected hamster brain homogenate rather than the current standard brain homogenates. © 2013 American Association of Blood Banks.

Men's Perceptions and Knowledge of Human Papillomavirus (HPV) Infection and Cervical Cancer

ERIC Educational Resources Information Center

McPartland, Tara S.; Weaver, Bethany A.; Lee, Shu-Kuang; Koutsky, Laura A.

2005-01-01

The authors assessed young men's knowledge and perceptions of genital human papillomavirus (HPV) infection to identify factors that predict intention to make positive behavioral changes. Male university students aged 18 to 25 years completed a self-report instrument to assess knowledge and perceptions of genital HPV infection. If diagnosed with…

Pig model mimicking chronic hepatitis E virus infection in immunocompromised patients to assess immune correlates during chronicity

PubMed Central

Cao, Dianjun; Cao, Qian M.; Subramaniam, Sakthivel; Yugo, Danielle M.; Heffron, C. Lynn; Rogers, Adam J.; Kenney, Scott P.; Tian, Debin; Matzinger, Shannon R.; Overend, Christopher; Catanzaro, Nicholas; LeRoith, Tanya; Wang, Heng; Piñeyro, Pablo; Lindstrom, Nicole; Clark-Deener, Sherrie; Yuan, Lijuan; Meng, Xiang-Jin

2017-01-01

Chronic hepatitis E virus (HEV) infection is a significant clinical problem in immunocompromised individuals such as organ transplant recipients, although the mechanism remains unknown because of the lack of an animal model. We successfully developed a pig model of chronic HEV infection and examined immune correlates leading to chronicity. The conditions of immunocompromised patients were mimicked by treating pigs with an immunosuppressive regimen including cyclosporine, azathioprine, and prednisolone. Immunocompromised pigs infected with HEV progressed to chronicity, because 8/10 drug-treated HEV-infected pigs continued fecal virus shedding beyond the acute phase of infection, whereas the majority (7/10) of mock-treated HEV-infected pigs cleared fecal viral shedding at 8 wk postinfection. During chronic infection, serum levels of the liver enzyme γ-glutamyl transferase and fecal virus shedding were significantly higher in immunocompromised HEV-infected pigs. To identify potential immune correlates of chronic infection, we determined serum levels of cytokines and cell-mediated immune responses in pigs. Results showed that HEV infection of immunocompromised pigs reduced the serum levels of Th1 cytokines IL-2 and IL-12, and Th2 cytokines IL-4 and IL-10, particularly during the acute phase of infection. Furthermore IFN-γ–specific CD4+ T-cell responses were reduced in immunocompromised pigs during the acute phase of infection, but TNF-α–specific CD8+ T-cell responses increased during the chronic phase of infection. Thus, active suppression of cell-mediated immune responses under immunocompromised conditions may facilitate the establishment of chronic HEV infection. This pig model will aid in delineating the mechanisms of chronic HEV infection and in developing effective therapeutics against chronic hepatitis E. PMID:28630341

Pig model mimicking chronic hepatitis E virus infection in immunocompromised patients to assess immune correlates during chronicity.

PubMed

Cao, Dianjun; Cao, Qian M; Subramaniam, Sakthivel; Yugo, Danielle M; Heffron, C Lynn; Rogers, Adam J; Kenney, Scott P; Tian, Debin; Matzinger, Shannon R; Overend, Christopher; Catanzaro, Nicholas; LeRoith, Tanya; Wang, Heng; Piñeyro, Pablo; Lindstrom, Nicole; Clark-Deener, Sherrie; Yuan, Lijuan; Meng, Xiang-Jin

2017-07-03

Chronic hepatitis E virus (HEV) infection is a significant clinical problem in immunocompromised individuals such as organ transplant recipients, although the mechanism remains unknown because of the lack of an animal model. We successfully developed a pig model of chronic HEV infection and examined immune correlates leading to chronicity. The conditions of immunocompromised patients were mimicked by treating pigs with an immunosuppressive regimen including cyclosporine, azathioprine, and prednisolone. Immunocompromised pigs infected with HEV progressed to chronicity, because 8/10 drug-treated HEV-infected pigs continued fecal virus shedding beyond the acute phase of infection, whereas the majority (7/10) of mock-treated HEV-infected pigs cleared fecal viral shedding at 8 wk postinfection. During chronic infection, serum levels of the liver enzyme γ-glutamyl transferase and fecal virus shedding were significantly higher in immunocompromised HEV-infected pigs. To identify potential immune correlates of chronic infection, we determined serum levels of cytokines and cell-mediated immune responses in pigs. Results showed that HEV infection of immunocompromised pigs reduced the serum levels of Th1 cytokines IL-2 and IL-12, and Th2 cytokines IL-4 and IL-10, particularly during the acute phase of infection. Furthermore IFN-γ-specific CD4 + T-cell responses were reduced in immunocompromised pigs during the acute phase of infection, but TNF-α-specific CD8 + T-cell responses increased during the chronic phase of infection. Thus, active suppression of cell-mediated immune responses under immunocompromised conditions may facilitate the establishment of chronic HEV infection. This pig model will aid in delineating the mechanisms of chronic HEV infection and in developing effective therapeutics against chronic hepatitis E.

Early variation of quick sequential organ failure assessment score to predict in-hospital mortality in emergency department patients with suspected infection.

PubMed

Najla, Lemachatti; Mar, Ortega; Andrea, Penaloza; Le Borgne, Pierrick; Claret, Pierre-Géraud; Occelli, Céline; Truchot, Jennifer; Dumas, Florence; Feral-Pierssens, Anne-Laure; Andrianjafy, Héry; Beaune, Sebastien; Yordanov, Youri; Hausfater, Pierre; Riou, Bruno; Bloom, Ben; Krastinova, Evguenia; Freund, Yonathan

2018-05-15

The quick sequential organ failure assessment (qSOFA) score showed good prognostic performance in patients with suspicion of infection in the emergency department (ED). However, previous studies only assessed the performance of individual values of qSOFA during the ED stay. As this score may vary over short timeframes, the optimal time of measurement, and the prognostic value of its variation are unclear. The objective of the present study was to prospectively assess the prognostic value of the change in qSOFA over the first 3 h (ΔqSOFA=qSOFA at 3 h-qSOFA at inclusion). This is an international prospective cohort study conducted in 17 EDs in France, Belgium, and Spain. From November 2016 to March 2017, patients with a suspected infection and a qSOFA score of 2 or higher were included and followed up until death or hospital discharge. qSOFA was measured at inclusion, 1 h and 3 h. Primary end point was in-hospital mortality, truncated at 28 days. Of 534 recruited patients, 512 were included in the analysis. The qSOFA was improved at 3 h (ΔqSOFA<0) in 287 (55%) patients. Overall in-hospital mortality was 27%: 44% when ΔqSOFA greater than 0, 36% when ΔqSOFA=0, and 18% when ΔqSOFA less than 0. A positive ΔqSOFA was independently associated with reduced in-hospital mortality (adjusted hazard ratio of 0.48, 95% confidence interval: 0.34-0.68). After modeling qSOFA kinetics in the first 3 h, there was a significant difference in adjusted slopes between patients who died and those who survived (0.15, 95% confidence interval: 0.09-0.22, P<0.001). In patients with suspected infection presenting to the ED with a qSOFA of 2 or higher, the early change in qSOFA is a strong independent predictor of mortality.

Association of HPV infection and clearance with cervicovaginal immunology and the vaginal microbiota

PubMed Central

Shannon, B; Yi, TJ; Perusini, S; Gajer, P; Ma, B; Humphrys, MS; Thomas-Pavanel, J; Chieza, L; Janakiram, P; Saunders, M; Tharao, W; Huibner, S; Shahabi, K; Ravel, J; Rebbapragada, A; Kaul, R

2016-01-01

Cervical human papillomavirus (HPV) infection may increase HIV risk. Since other genital infections enhance HIV susceptibility by inducing inflammation, we assessed the impact of HPV infection and clearance on genital immunology and the cervico-vaginal microbiome. Genital samples were collected from 65 women for HPV testing, immune studies and microbiota assessment; repeat HPV testing was performed after 6 months. All participants were HIV-uninfected and free of bacterial STIs. Cytobrush-derived T cell and dendritic cell subsets were assessed by multiparameter flow cytometry. Undiluted cervico-vaginal secretions were used to determine cytokine levels by multiplex ELISA, and to assess bacterial community composition and structure by 16S rRNA gene sequence analysis. Neither HPV infection nor clearance were associated with broad differences in cervical T cell subsets or cytokines, although HPV clearance was associated with increased Langerhans cells and HPV infection with elevated IP-10 and MIG. Individuals with HPV more frequently had a high diversity cervico-vaginal microbiome (community state type IV) and were less likely to have an L. gasseri predominant microbiome. In summary, HPV infection and/or subsequent clearance was not associated with inflammation or altered cervical T cell subsets, but associations with increased Langerhans cells and the composition of the vaginal microbiome warrant further exploration. PMID:28120845

Clinical and immunological assessment of therapeutic immunization with a subunit vaccine for recurrent ocular canine herpesvirus-1 infection in dogs.

PubMed

Ledbetter, Eric C; Kim, Kay; Dubovi, Edward J; Mohammed, Hussni O; Felippe, M Julia B

2016-12-25

Latent canine herpesvirus-1 (CHV-1) infections are common in domestic dogs and reactivation of latent virus may be associated with recurrent ocular disease. The objectives of the present study were to evaluate the ability of a subunit CHV-1 vaccine to stimulate peripheral CHV-1 specific immunity and prevent recurrent CHV-1 ocular disease and viral shedding. Mature dogs with experimentally-induced latent CHV-1 infection received a 2-dose CHV-1 vaccine series. Recurrent ocular CHV-1 infection was induced by corticosteroid administration in the prevaccinal, short-term postvaccinal (2 weeks post-vaccination), and long-term postvacccinal (34 weeks post-vaccination) periods. Immunological, virological, and clinical parameters were evaluated during each study period. Quantitative assessment of peripheral immunity included lymphocyte immunophenotyping, proliferation response, and interferon-γ production; and CHV-1 virus neutralizing antibody production. In the present study, vaccination did not prevent development of ocular disease and viral shedding; however, there was a significant decrease in clinical ocular disease scores in the short-term postvaccinal period. Significant alterations in peripheral immunity detected in the dogs during the short-term and long-term postvaccinal periods included increased T and B lymphocyte subpopulation percentage distributions, increased lymphocyte expression of major histocompatibility complex class I and II, increased CHV-1 virus neutralizing antibody titers, decreased lymphocyte proliferation, and decreased interferon-γ production. Vaccination of latently infected mature dogs with the selected subunit CHV-1 vaccine was not effective in preventing recurrent ocular CHV-1 infection and viral shedding induced by corticosteroid administration. The vaccine did induce long-term CHV-1 specific immunity and may decrease the severity of clinical ocular disease in the immediate postvaccinal period. Copyright © 2016 Elsevier B.V. All rights

Rotavirus intestinal infection induces an oral mucosa cytokine response.

PubMed

Gómez-Rial, José; Curras-Tuala, María José; Rivero-Calle, Irene; Rodríguez-Tenreiro, Carmen; Redondo-Collazo, Lorenzo; Gómez-Carballa, Alberto; Pardo-Seco, Jacobo; Salas, Antonio; Martinón-Torres, Federico

2018-01-01

Salivary glands are known immune effector sites and considered to be part of the whole mucosal immune system. The aim of the present study was to assess the salivary immune response to rotavirus (RV) infection through the analysis of the cytokine immune profile in saliva. A prospective comparative study of serial saliva samples from 27 RV-infected patients (sampled upon admission to the hospital during acute phase and at convalescence-i.e. at least three months after recovery) and 36 healthy controls was performed. Concentrations of 11 salivary cytokines (IFN-γ, IFN-α2, IL-1β, IL-6, IL-8, IL-10, IL-15, IL12p70, TNF-α, IFN-λ1, IL-22) were determined. Cytokine levels were compared between healthy controls acute infection and convalescence. The correlation between clinical data and salivary cytokine profile in infected children was assessed. The salivary cytokine profile changes significantly in response to acute RV infection. In RV-infected patients, IL-22 levels were increased in the acute phase with respect to convalescence (P-value < 0.001). Comparisons between infected and control group showed significant differences in salivary IFN-α2, IL-1β, IL-6, IL-8, IL-10 and IL-22. Although acute-phase levels of IL-12, IL-10, IL-6 and IFN-γ showed nominal association with Vesikari's severity, this trend did not reach statistical significance after multiple test adjustment. RV infection induces a host salivary immune response, indicating that immune mucosal response to RV infection is not confined to the intestinal mucosa. Our data point to a whole mucosal implication in the RV infection as a result of the integrative mucosal immune response, and suggest the salivary gland as effector site for RV infection.

Rotavirus intestinal infection induces an oral mucosa cytokine response

PubMed Central

Curras-Tuala, María José; Rivero-Calle, Irene; Rodríguez-Tenreiro, Carmen; Redondo-Collazo, Lorenzo; Gómez-Carballa, Alberto; Pardo-Seco, Jacobo

2018-01-01

Introduction Salivary glands are known immune effector sites and considered to be part of the whole mucosal immune system. The aim of the present study was to assess the salivary immune response to rotavirus (RV) infection through the analysis of the cytokine immune profile in saliva. Material and methods A prospective comparative study of serial saliva samples from 27 RV-infected patients (sampled upon admission to the hospital during acute phase and at convalescence—i.e. at least three months after recovery) and 36 healthy controls was performed. Concentrations of 11 salivary cytokines (IFN-γ, IFN-α2, IL-1β, IL-6, IL-8, IL-10, IL-15, IL12p70, TNF-α, IFN-λ1, IL-22) were determined. Cytokine levels were compared between healthy controls acute infection and convalescence. The correlation between clinical data and salivary cytokine profile in infected children was assessed. Results The salivary cytokine profile changes significantly in response to acute RV infection. In RV-infected patients, IL-22 levels were increased in the acute phase with respect to convalescence (P-value < 0.001). Comparisons between infected and control group showed significant differences in salivary IFN-α2, IL-1β, IL-6, IL-8, IL-10 and IL-22. Although acute-phase levels of IL-12, IL-10, IL-6 and IFN-γ showed nominal association with Vesikari’s severity, this trend did not reach statistical significance after multiple test adjustment. Conclusions RV infection induces a host salivary immune response, indicating that immune mucosal response to RV infection is not confined to the intestinal mucosa. Our data point to a whole mucosal implication in the RV infection as a result of the integrative mucosal immune response, and suggest the salivary gland as effector site for RV infection. PMID:29621276

In Vivo Assessment of Phage and Linezolid Based Implant Coatings for Treatment of Methicillin Resistant S. aureus (MRSA) Mediated Orthopaedic Device Related Infections

PubMed Central

Kaur, Sandeep; Harjai, Kusum; Chhibber, Sanjay

2016-01-01

Staphylococcus comprises up to two-thirds of all pathogens in orthopaedic implant infections with two species respectively Staphylococcus aureus and Staphylococcus epidermidis, being the predominate etiological agents isolated. Further, with the emergence of methicillin-resistant S. aureus (MRSA), treatment of S. aureus implant infections has become more difficult, thus representing a devastating complication. Use of local delivery system consisting of S.aureus specific phage along with linezolid (incorporated in biopolymer) allowing gradual release of the two agents at the implant site represents a new, still unexplored treatment option (against orthopaedic implant infections) that has been studied in an animal model of prosthetic joint infection. Naked wire, hydroxypropyl methylcellulose (HPMC) coated wire and phage and /or linezolid coated K-wire were surgically implanted into the intra-medullary canal of mouse femur bone of respective groups followed by inoculation of S.aureus ATCC 43300(MRSA). Mice implanted with K-wire coated with both the agents i.e phage as well as linezolid (dual coated wires) showed maximum reduction in bacterial adherence, associated inflammation of the joint as well as faster resumption of locomotion and motor function of the limb. Also, all the coating treatments showed no emergence of resistant mutants. Use of dual coated implants incorporating lytic phage (capable of self-multiplication) as well as linezolid presents an attractive and aggressive early approach in preventing as well as treating implant associated infections caused by methicillin resistant S. aureus strains as assessed in a murine model of experimental joint infection. PMID:27333300

Liver function assessment in malaria, typhoid and malaria-typhoid co-infection in Aba, Abia State, Nigeria.

PubMed

Enemchukwu, B N; Ibe, C C; Udedi, S C; Iroha, A; Ubaoji, K I; Ogundapo, S S

2014-06-01

Malaria and typhoid fever are among the most endemic diseases in the tropics and are associated with poverty and underdevelopment with significant morbidity and mortality. Both diseases can lead to liver damage if not properly treated. The liver function assessment was therefore conducted on (90) volunteer patients; comprising (30) patients with malaria only, (30) with typhoid only and (30) with malaria-typhoid co-infection randomly selected from Abia State University Teaching Hospital, Aba, Abia State, Nigeria and (20) healthy individuals were used as control. Blood samples collected from these subjects were screened for malaria parasite and Staphylococcus typhi using standard methods. Mean serum levels of ALP (112.55±84.23), AST (31.33±12.80), ALT (23.10±11.84), TB (19.43±5.02), CB (5.91±3.03) and ALP (116.69±48.68), AST (28.33±11.72), ALT (22.8±5.94), TB (19.31±5.84),CB (5.60±2.50) were obtained for those subjects with malaria and typhoid respectively and subjects with malaria-typhoid co-infection recorded the following; ALP (134.33±56.62), AST (33.97±8.43), ALT (24.40±4.37),TB (21.27±2.96),CB (6.58±3.10) while the control subjects had mean serum levels ofALP (71.05±18.18), AST (16.65±7.45), ALT (13.85±6.09), TB (10.05±4.85) and CB (3.00±1.67). These mean values were subjected to a statistical test using students t-test which revealed a significant increase (p<0.05).The results suggest that malaria, typhoid and malaria-typhoid co-infection can elevate ALP, AST, ALT, TB and CB serum levels and can lead to liver damage if not properly treated.

Oxantel pamoate-albendazole for Trichuris trichiura infection.

PubMed

Speich, Benjamin; Ame, Shaali M; Ali, Said M; Alles, Rainer; Huwyler, Jörg; Hattendorf, Jan; Utzinger, Jürg; Albonico, Marco; Keiser, Jennifer

2014-02-13

Infections with soil-transmitted helminths (Ascaris lumbricoides, hookworm, and Trichuris trichiura) are widespread and often occur concomitantly. These parasitic-worm infections are typically treated with albendazole or mebendazole, but both drugs show low efficacy against T. trichiura. Albendazole is the drug of choice against hookworm. In this double-blind trial conducted on Pemba Island, Tanzania, we randomly assigned children, 6 to 14 years of age, to receive one of four treatments: oxantel pamoate at a dose of 20 mg per kilogram of body weight, plus 400 mg of albendazole, administered on consecutive days; oxantel pamoate at a single dose of 20 mg per kilogram; albendazole at a single dose of 400 mg; or mebendazole at a single dose of 500 mg. We assessed the efficacy and safety profile of oxantel pamoate-albendazole when used in the treatment of T. trichiura infection (primary outcome) and concomitant soil-transmitted helminth infection (secondary outcome). Efficacy was determined by means of assessment of the cure rate and egg-reduction rate. Adverse events were assessed four times after treatment. Complete data were available for 458 children, of whom 450 were infected with T. trichiura, 443 with hookworm, and 293 with A. lumbricoides. The cure rate of T. trichiura infection was significantly higher with oxantel pamoate-albendazole than with mebendazole (31.2% vs. 11.8%, P=0.001), as was the egg-reduction rate (96.0% [95% confidence interval {CI}, 93.5 to 97.6] vs. 75.0% [95% CI, 64.2 to 82.0]). The cure rate with albendazole (2.6%) and the egg-reduction rate with albendazole (45.0%; 95% CI, 32.0 to 56.4) were significantly lower than the rates with mebendazole (P=0.02 for the comparison of cure rates). Oxantel pamoate had low efficacy against hookworm and A. lumbricoides. Adverse events (mainly mild) were reported by 30.9% of all children. Treatment with oxantel pamoate-albendazole resulted in higher cure and egg-reduction rates for T. trichiura infection

Prevention of catheter-related blood stream infection.

PubMed

Byrnes, Matthew C; Coopersmith, Craig M

2007-08-01

Catheter-related blood stream infections are a morbid complication of central venous catheters. This review will highlight a comprehensive approach demonstrated to prevent catheter-related blood stream infections. Elements of prevention important to inserting a central venous catheter include proper hand hygiene, use of full barrier precautions, appropriate skin preparation with 2% chlorhexidine, and using the subclavian vein as the preferred anatomic site. Rigorous attention needs to be given to dressing care, and there should be daily assessment of the need for central venous catheters, with prompt removal as soon as is practicable. Healthcare workers should be educated routinely on methods to prevent catheter-related blood stream infections. If rates remain higher than benchmark levels despite proper bedside practice, antiseptic or antibiotic-impregnated catheters can also prevent infections effectively. A recent program utilizing these practices in 103 ICUs in Michigan resulted in a 66% decrease in infection rates. There is increasing recognition that a comprehensive strategy to prevent catheter-related blood stream infections can prevent most infections, if not all. This suggests that thousands of infections can potentially be averted if the simple practices outlined herein are followed.

Evaluation of bloodstream infections, Clostridium difficile infections, and gut microbiota in pediatric oncology patients.

PubMed

Nycz, Bryan T; Dominguez, Samuel R; Friedman, Deborah; Hilden, Joanne M; Ir, Diana; Robertson, Charles E; Frank, Daniel N

2018-01-01

Bloodstream infections (BSI) and Clostridium difficile infections (CDI) in pediatric oncology/hematology/bone marrow transplant (BMT) populations are associated with significant morbidity and mortality. The objective of this study was to explore possible associations between altered microbiome composition and the occurrence of BSI and CDI in a cohort of pediatric oncology patients. Stool samples were collected from all patients admitted to the pediatric oncology floor from Oct.-Dec. 2012. Bacterial profiles from patient stools were determined by bacterial 16S rRNA gene profiling. Differences in overall microbiome composition were assessed by a permutation-based multivariate analysis of variance test, while differences in the relative abundances of specific taxa were assessed by Kruskal-Wallis tests. At admission, 9 of 42 patients (21%) were colonized with C. difficile, while 6 of 42 (14%) subsequently developed a CDI. Furthermore, 3 patients (7%) previously had a BSI and 6 patients (14%) subsequently developed a BSI. Differences in overall microbiome composition were significantly associated with disease type (p = 0.0086), chemotherapy treatment (p = 0.018), BSI following admission from any cause (p < 0.0001) or suspected gastrointestinal organisms (p = 0.00043). No differences in baseline microbiota were observed between individuals who did or did not subsequently develop C. difficile infection. Additionally, multiple bacterial groups varied significantly between subjects with post-admission BSI compared with no BSI. Our results suggest that differences in gut microbiota not only are associated with type of cancer and chemotherapy, but may also be predictive of subsequent bloodstream infection.

Assessing the impact of a temporary class drug order on ethylphenidate-related infections among people who inject drugs in Lothian, Scotland: an interrupted time-series analysis.

PubMed

Yeung, Alan; Weir, Amanda; Austin, Hannah; Morrison, Kirsty; Inverarity, Donald; Sherval, Jim; Henderson, Naomi; Joshi, Shruti; Ure, Roisin; McAuley, Andrew

2017-10-01

In April 2015, the UK government enacted a temporary class drug order (TCDO) on ethylphenidate in response to reported harms associated with its use, in particular an outbreak of infections among people who inject drugs (PWID) in Lothian, Scotland. This study assesses the effect that the TCDO had on reducing the most common infections identified during the outbreak: Streptococcus pyogenes and Staphylococcus aureus. The outbreak was split into a pre-intervention period (35 weeks) and a post-intervention period (26 weeks) based around the date of the TCDO. Segmented negative binomial regression models were used to compare trends in weekly counts of infections between the pre- and post-intervention periods. PWID in the Lothian region of Scotland. Cases of S. pyogenes and S. aureus infections reported within the National Health Service, Lothian. There were 251 S. pyogenes and/or S. aureus infections recorded among 211 PWID between February 2014 and December 2015: 171 infections in the pre-intervention period and 51 in the post-intervention period. Significant trend changes in weekly S. pyogenes and/or S. aureus infections following the TCDO were found [relative risk (RR) = 0.88, 95% confidence interval (CI) = 0.82-0.94]. PWID who self-reported using novel psychoactive substances (NPS) were at higher risk of acquiring these infections (RR = 1.81, 95% CI = 1.12-2.93), particularly when comparing the risk of infection with NPS use for a specific strain, S. pyogenes emm76.0, against the risk of infection with NPS use for S. pyogenes (emm types other than emm76.0) (RR = 3.49, 95% CI = 1.32-9.21). The UK government's 2015 temporary class drug order on ethylphenidate was effective in reducing infections among people who inject drugs during an outbreak situation in Lothian, Scotland. © 2017 Crown copyright.

A computer-based medical record system and personal digital assistants to assess and follow patients with respiratory tract infections visiting a rural Kenyan health centre.

PubMed

Diero, Lameck; Rotich, Joseph K; Bii, John; Mamlin, Burke W; Einterz, Robert M; Kalamai, Irene Z; Tierney, William M

2006-04-10

Clinical research can be facilitated by the use of informatics tools. We used an existing electronic medical record (EMR) system and personal data assistants (PDAs) to assess the characteristics and outcomes of patients with acute respiratory illnesses (ARIs) visiting a Kenyan rural health center. We modified the existing EMR to include details on patients with ARIs. The EMR database was then used to identify patients with ARIs who were prospectively followed up by a research assistant who rode a bicycle to patients' homes and entered data into a PDA. A total of 2986 clinic visits for 2009 adult patients with respiratory infections were registered in the database between August 2002 and January 2005; 433 patients were selected for outcome assessments. These patients were followed up in the villages and assessed at 7 and 30 days later. Complete follow-up data were obtained on 381 patients (88%) and merged with data from the enrollment visit's electronic medical records and subsequent health center visits to assess duration of illness and complications. Symptoms improved at 7 and 30 days, but a substantial minority of patients had persistent symptoms. Eleven percent of patients sought additional care for their respiratory infection. EMRs and PDA are useful tools for performing prospective clinical research in resource constrained developing countries.

Infection after primary hip arthroplasty

PubMed Central

2011-01-01

Background and purpose The aim of the present study was to assess incidence of and risk factors for infection after hip arthroplasty in data from 3 national health registries. We investigated differences in risk patterns between surgical site infection (SSI) and revision due to infection after primary total hip arthroplasty (THA) and hemiarthroplasty (HA). Materials and methods This observational study was based on prospective data from 2005–2009 on primary THAs and HAs from the Norwegian Arthroplasty Register (NAR), the Norwegian Hip Fracture Register (NHFR), and the Norwegian Surveillance System for Healthcare–Associated Infections (NOIS). The Norwegian Patient Register (NPR) was used for evaluation of case reporting. Cox regression analyses were performed with revision due to infection as endpoint for data from the NAR and the NHFR, and with SSI as the endpoint for data from the NOIS. Results The 1–year incidence of SSI in the NOIS was 3.0% after THA (167/5,540) and 7.3% after HA (103/1,416). The 1–year incidence of revision due to infection was 0.7% for THAs in the NAR (182/24,512) and 1.5% for HAs in the NHFR (128/8,262). Risk factors for SSI after THA were advanced age, ASA class higher than 2, and short duration of surgery. For THA, the risk factors for revision due to infection were male sex, advanced age, ASA class higher than 1, emergency surgery, uncemented fixation, and a National Nosocomial Infection Surveillance (NNIS) risk index of 2 or more. For HAs inserted after fracture, age less than 60 and short duration of surgery were risk factors of revision due to infection. Interpretation The incidences of SSI and revision due to infection after primary hip replacements in Norway are similar to those in other countries. There may be differences in risk pattern between SSI and revision due to infection after arthroplasty. The risk patterns for revision due to infection appear to be different for HA and THA. PMID:22066562

Scaffold-based Anti-infection Strategies in Bone Repair

PubMed Central

Johnson, Christopher T.; García, Andrés J.

2014-01-01

Bone fractures and non-union defects often require surgical intervention where biomaterials are used to correct the defect, and approximately 10% of these procedures are compromised by bacterial infection. Currently, treatment options are limited to sustained, high doses of antibiotics and surgical debridement of affected tissue, leaving a significant, unmet need for the development of therapies to combat device-associated biofilm and infections. Engineering implants to prevent infection is a desirable material characteristic. Tissue engineered scaffolds for bone repair provide a means to both regenerate bone and serve as a base for adding antimicrobial agents. Incorporating anti-infection properties into regenerative medicine therapies could improve clinical outcomes and reduce the morbidity and mortality associated with biomaterial implant-associated infections. This review focuses on current animal models and technologies available to assess bone repair in the context of infection, antimicrobial agents to fight infection, the current state of antimicrobial scaffolds, and future directions in the field. PMID:25476163

Microbial risk assessment in heterogeneous aquifers: 2. Infection risk sensitivity

NASA Astrophysics Data System (ADS)

Molin, S.; Cvetkovic, V.; StenströM, T. A.

2010-05-01

The entire chain of events of human disease transmitted through contaminated water, from pathogen introduction into the source (E. coli, rotavirus, and Hepatitis A), pathogen migration through the aquifer pathway, to ingestion via a supply well, and finally, the potential infection in the human host, is investigated. The health risk calculations are based on a relevant hazardous event with safe setback distances estimated by considering the infection risk from peak exposure in compliance with an acceptable level defined by a regulatory agency. A site-specific hypothetical scenario is illustrated for an aquifer with similar characteristics as the Cape Cod site, Massachusetts (United States). Relatively large variation of safe distances for the three index pathogens is found; individually, none of the index pathogens could predict the safe distance under the wide range of conditions investigated. It is shown that colloid filtration theory (CFT) with spatially variable attachment-detachment rates yields significantly different results from the effective CFT model (i.e., assuming spatially constant parameters).

Assessing the effect of community health nursing care management at home on war-worn soldiers’ physical problems suffering from spinal cord complications (urinary infection, bedsore)

PubMed Central

Rastegari, Mohammad; Dehkordi, Akbar Jaafariyan; Sabouhi, Fakhri; Ghalriz, Parvin

2010-01-01

BACKGROUND: Veterans are among the highly-susceptible and highly-esteemed groups of the society. there is no correct, principled, and comprehensive programming with respect to home-nursing care for them. METHODS: In this quasi-experimental study, 26 veterans with spinal cord complications, with a 70-percent damage who were resident of Najaf Abad, Iran were concluded. The data were gathered by a checklist consisted of two parts, the first part included the demographic data and the second part consisted of Para-clinical (clinical findings) assessment of the veterans suffering from urinary infection, laboratorial assessments, and assessing the bedsores. The researcher visited all the veterans and completed the checklist by interviewing them. RESULTS: The mean age of the veterans was 45 (5.1) years and the highest frequency (53.8%) belonged to the age range of 40-44 years. The mean number of the family members was 4.4 people. The veterans who had paraplegia damage included 88.6%. Considering the damage rate, the highest frequency (69.2%) belonged to thoracic vertebra level. all the 26 veterans had been suffering from urinal infection before the managerial intervention; however 20 subjects (76.9%) had urinal infection after the intervention. CONCLUSIONS: It can be stated that pressure wounds are preventable and these caring measures can be offered to susceptible groups of the community in a better and cheaper way if more studies are done with a closer contact and a higher number of samples in addition to have unison among the community-based systems. PMID:22069406

An assessment of food safety information provision for UK chemotherapy patients to reduce the risk of foodborne infection.

PubMed

Evans, E W; Redmond, E C

2017-12-01

Given the increased risk of foodborne infection to cancer patients receiving chemotherapy treatment, and the risk of listeriosis reportedly five-times greater to this immunocompromised patient group, there is a need to ensure the implementation of domestic food safety practices among chemotherapy patients and their family caregivers. However, information regarding the adequacy of resources to inform and enable patients to implement domestic food safety practices to reduce the risk of foodborne infection is limited. Consequently, this study aimed to evaluate the provision of food safety information available to UK chemotherapy patients. In-depth semi-structured interviews and content analysis of online patient information resources. Interviews with patients and family caregivers (n = 15) were conducted to explore food-related experiences during chemotherapy treatment. Online food-related information resources for chemotherapy patients (n = 45) were obtained from 35 of 154 National Health Service chemotherapy providers in England, Scotland, and Wales, the Department of Health (DoH) and three of 184 identified UK cancer charities. Identified food-related information resources were reviewed using a content-analysis approach to assess the inclusion of food safety information for chemotherapy patients. In-depth interviews established that many patients indicated awareness of immunosuppression during treatment. Although patients reported practicing caution to reduce the risk of communicable diseases by avoiding crowded spaces/public transport, food safety was reported to be of minimal concern during treatment and the risk of foodborne infection was often underestimated. The review of online food-related patient information resources established that many resources failed to highlight the increased risk of foodborne infection and emphasize the importance of food safety for patients during chemotherapy treatment. Considerable information gaps exist, particularly in

Ability of immunodiagnostic tests to differentiate between dogs naturally infected with Leishmania infantum and Leishmune(®)-vaccinated dogs.

PubMed

Ribeiro, R A N; Teixeira-Neto, R G; Belo, V S; Ferreira, E C; Schallig, H D F H; Silva, E S

2015-06-01

Visceral leishmaniasis (VL) is a serious chronic disease with a lethality rate of up to 10% in humans. In urban areas of Brazil, dogs are the main reservoirs of the etiological agent (Leishmania infantum) of VL, and the Brazilian Ministry of Health recommends the euthanasia of animals that are seropositive in both the immunochromatographic dual path platform rapid test (DPP(®); Bio-Manguinhos) and the enzyme-linked immunosorbent assay (ELISA) with an L. major-like antigen (Bio-Manguinhos). Vaccination is an additional tool in the control of canine VL, but the use of Leishmune(®) (Zoetis Indústria de Produtos Veterinários, São Paulo, SP, Brazil), which contains the fucose mannose ligand (FML) isolated from L. donovani, is not currently recommended by the Brazilian Ministry of Health because vaccinated animals may exhibit positive serology and there are reservations regarding the efficacy of the vaccine. The aims of the present study were: (i) to verify the abilities of the fast agglutination screening test (FAST), the direct agglutination test (DAT), the indirect fluorescent-antibody test (IFAT), the DPP rapid test, and ELISA tests with L. major-like and FML antigens to differentiate between L. infantum-infected and Leishmune(®)-vaccinated dogs, and (ii) to analyze the sensitivities and specificities of the different methods. The reactivities to these tests of Leishmune(®)-vaccinated dogs (n = 71), asymptomatic (n = 20) and symptomatic (n = 20) naturally infected dogs, and unvaccinated healthy control dogs (n = 5) were compared. None of the Leishmune(®)-vaccinated dogs tested seropositive in FAST and DAT, although one dog was reactive to DPP and four dogs to ELISA/L. major-like and IFAT tests. While 69 (97%) of vaccinated dogs reacted to ELISA/FML, only one was seropositive in both ELISA/L. major-like and IFAT tests. Individually, all immunodiagnostic tests presented high specificities and positive likelihood ratios (LR+), and high specificity values were

HIV and syphilis infection among men attending a [corrected] sexually transmitted infection clinic in Puerto Rico.

PubMed

Colón-López, Vivian; Ortiz, Ana P; Banerjee, Geetanjoli; Gertz, Alida M; García, Hermes

2013-03-01

This study aimed to assess the demographic, behavioral, and clinical factors associated with HIV and syphilis infection among a sample of men attending a sexually transmitted infection clinic during 2009 to 2010 in San Juan, Puerto Rico (PR). A sample of 350 clinical records from men visiting the clinic for the first time during 2009 to 2010 was reviewed. Descriptive statistics were used to describe the study sample, and bivariate analyses were performed separately for HIV and syphilis to identify factors associated with these infectious diseases. Variables that were significantly associated (p < 0.05) with HIV and syphilis in the bivariate analysis were considered for inclusion in the logistic regression models. Overall, 11.2% and 14.1% of the men were infected with HIV and syphilis, respectively, and 5.1% were coinfected with HIV and syphilis. In multivariate logistic regression models, ever injecting drugs (POR = 8.1; 95% CI 3.0, 21.8) and being a man who has sex with men (MSM) (POR = 5.3; 95% CI 2.3, 11.9) were positively associated with HIV infection. Being a man older than 45 years (POR = 4.0; 95% CI: 1.9, 8.9) and being an MSM (POR = 2.5; 95% CI: 1.3, 4.9) were both significantly associated with syphilis infection. These findings reinforce the need for greater education and prevention efforts for HIV and other STIs among men in PR, particularly those who are MSM. However, there is a need to make an a priori assessment of the level of health literacy in the members of this group so that a culturally sensitive intervention can be provided to the men who attend this STI clinic.

HIV and Syphilis Infection among Men attending a Sexually Transmitted Infection Clinic in Puerto Rico

PubMed Central

Colón-López, Vivian; Ortiz, Ana P.; Banerjee, Geetanjoli; Gertz, Alida M.; García, Hermes

2013-01-01

Objective This study aimed to assess the demographic, behavioral, and clinical factors associated with HIV and syphilis infection among a sample of men attending a sexually transmitted infection clinic during 2009 to 2010 in San Juan, Puerto Rico (PR). Methods A sample of 350 clinical records from men visiting the clinic for the first time during 2009 to 2010 was reviewed. Descriptive statistics were used to describe the study sample, and bivariate analyses were performed separately for HIV and syphilis to identify factors associated with these infectious diseases. Variables that were significantly associated (p<0.05) with HIV and syphilis in the bivariate analysis were considered for inclusion in the logistic regression models. Results Overall, 11.2% and 14.1% of the men were infected with HIV and syphilis, respectively, and 5.1% were coinfected with HIV and syphilis. In multivariate logistic regression models, ever injecting drugs (POR = 8.1; 95%Cl 3.0, 21.8) and being a man who has sex with men (MSM) (POR = 5.3; 95%CI 2.3, 11.9) were positively associated with HIV infection. Being a man older than 45 years (POR = 4.0; 95%CI: 1.9, 8.9) and being an MSM (POR = 2.5; 95%CI: 1.3, 4.9) were both significantly associated with syphilis infection. Conclusion These findings reinforce the need for greater education and prevention efforts for HIV and other STIs among men in PR, particularly those who are MSM. However, there is a need to make an a priori assessment of the level of health literacy in the members of this group so that a culturally sensitive intervention can be provided to the men who attend this STI clinic. PMID:23556260

Tuberculosis and latent tuberculosis infection among healthcare workers in Kisumu, Kenya.

PubMed

Agaya, Janet; Nnadi, Chimeremma D; Odhiambo, Joseph; Obonyo, Charles; Obiero, Vincent; Lipke, Virginia; Okeyo, Elisha; Cain, Kevin; Oeltmann, John E

2015-12-01

To assess prevalence and occupational risk factors of latent TB infection and history of TB disease ascribed to work in a healthcare setting in western Kenya. We conducted a cross-sectional survey among healthcare workers in western Kenya in 2013. They were recruited from dispensaries, health centres and hospitals that offer both TB and HIV services. School workers from the health facilities' catchment communities were randomly selected to serve as the community comparison group. Latent TB infection was diagnosed by tuberculin skin testing. HIV status of participants was assessed. Using a logistic regression model, we determined the adjusted odds of latent TB infection among healthcare workers compared to school workers; and among healthcare workers only, we assessed work-related risk factors for latent TB infection. We enrolled 1005 healthcare workers and 411 school workers. Approximately 60% of both groups were female. A total of 22% of 958 healthcare workers and 12% of 392 school workers tested HIV positive. Prevalence of self-reported history of TB disease was 7.4% among healthcare workers and 3.6% among school workers. Prevalence of latent TB infection was 60% among healthcare workers and 48% among school workers. Adjusted odds of latent TB infection were 1.5 times higher among healthcare workers than school workers (95% confidence interval 1.2-2.0). Healthcare workers at all three facility types had similar prevalence of latent TB infection (P = 0.72), but increasing years of employment was associated with increased odds of LTBI (P < 0.01). Healthcare workers at facilities in western Kenya which offer TB and HIV services are at increased risk of latent TB infection, and the risk is similar across facility types. Implementation of WHO-recommended TB infection control measures are urgently needed in health facilities to protect healthcare workers. © 2015 John Wiley & Sons Ltd.

Risk perceptions for avian influenza virus infection among poultry workers, China.

PubMed

Yu, Qi; Liu, Linqing; Pu, Juan; Zhao, Jingyi; Sun, Yipeng; Shen, Guangnian; Wei, Haitao; Zhu, Junjie; Zheng, Ruifeng; Xiong, Dongyan; Liu, Xiaodong; Liu, Jinhua

2013-02-01

To determine risk for avian influenza virus infection, we conducted serologic surveillance for H5 and H9 subtypes among poultry workers in Beijing, China, 2009-2010, and assessed workers' understanding of avian influenza. We found that poultry workers had considerable risk for infection with H9 subtypes. Increasing their knowledge could prevent future infections.

Semen CD4+ T Cells and Macrophages Are Productively Infected at All Stages of SIV infection in Macaques

PubMed Central

Bernard-Stoecklin, Sibylle; Gommet, Céline; Corneau, Aurélien B.; Guenounou, Sabrina; Torres, Claire; Dejucq-Rainsford, Nathalie; Cosma, Antonio; Dereuddre-Bosquet, Nathalie; Le Grand, Roger

2013-01-01

The mucosal events of HIV transmission have been extensively studied, but the role of infected cells present in the genital and rectal secretions, and in the semen, in particular, remains a matter of debate. As a prerequisite to a thorough in vivo investigation of the early transmission events through infected cells, we characterized in detail by multi-parameter flow cytometry the changes in macaque seminal leukocytes during SIVmac251 infection, focusing on T cells, macrophages and dendritic cells. Using immunocytofluorescence targeting SIV proteins and real-time quantitative PCR targeting SIV DNA, we investigated the nature of the infected cells on sorted semen leukocytes from macaques at different stages of infection. Finally, we cocultured semen CD4+ T cells and macrophages with a cell line permissive to SIV infection to assess their infectivity in vitro. We found that primary infection induced strong local inflammation, which was associated with an increase in the number of leukocytes in semen, both factors having the potential to favor cell-associated virus transmission. Semen CD4+ T cells and macrophages were productively infected at all stages of infection and were infectious in vitro. Lymphocytes had a mucosal phenotype and expressed activation (CD69 & HLA-DR) and migration (CCR5, CXCR4, LFA-1) markers. CD69 expression was increased in semen T cells by SIV infection, at all stages of infection. Macrophages predominated at all stages and expressed CD4, CCR5, MAC-1 and LFA-1. Altogether, we demonstrated that semen contains the two major SIV-target cells (CD4+ T cells and macrophages). Both cell types can be productively infected at all stages of SIV infection and are endowed with markers that may facilitate transmission of infection during sexual exposure. PMID:24348253

Reduced mortality associated with breast-feeding-acquired HIV infection and breast-feeding among HIV-infected children in Zambia.

PubMed

Fox, Matthew P; Brooks, Daniel; Kuhn, Louise; Aldrovandi, Grace; Sinkala, Moses; Kankasa, Chipepo; Mwiya, Mwiya; Horsburgh, Robert; Thea, Donald M

2008-05-01

In developing countries, where mother-to-child transmission of HIV through breast-feeding is common, little is known about the impact of postpartum transmission on child survival. This study assessed whether children infected postpartum have longer survival from time of infection versus those infected during gestation or delivery. We used a prospective cohort study to analyze data from 213 HIV-infected children enrolled in a breast-feeding intervention trial in Lusaka, Zambia (2001 to 2004). We compared mortality 1 year after HIV infection in children stratified by age of infection: 0 to 3 days (intrauterine [IU] group), 4 to 40 days (intrapartum/early postpartum [IP/EPP] group), and >40 days (postpartum [PP] group). A total of 61, 71, and 81 children were infected in the IU, IP/EPP, and PP groups, respectively. Children with intrauterine or intrapartum/early postpartum transmission had higher mortality over the first 12 months after infection than children with postpartum transmission (P = 0.001 and P = 0.006, respectively); no differences were detected between children with intrauterine and intrapartum/early postpartum transmission. Nearly 20% of the IU and IP/EPP groups died by 100 days after infection, whereas nearly 10% of the PP group had died by this time. After adjusting for birth weight, maternal CD4 cell count, breast-feeding, and maternal death, children infected postpartum had one quarter the mortality rate (hazard ratio [HR] = 0.27, 95% confidence interval [CI]: 0.15 to 0.50) of those infected in utero. Stopping breast-feeding increased mortality in infected children (HR = 3.1, 95% CI: 1.8 to 5.3). This study demonstrates a survival benefit among children infected postpartum versus children infected during pregnancy or delivery and a benefit to increased breast-feeding duration among infected children. Testing children for HIV early may provide a means to allow for earlier intervention.

A single low-dose of hydrocortisone enhances cognitive functioning in HIV-infected women.

PubMed

Rubin, Leah H; Phan, K Luan; Keating, Sheila M; Maki, Pauline M

2018-06-14

Low-dose hydrocortisone (LDH) enhances aspects of learning and memory in select populations including patients with PTSD and HIV-infected men. HIV-infected women show impairments in learning and memory, but the cognitive effects of LDH in HIV-infected women are unknown. Double-blind, placebo-controlled, cross-over study examining the time-dependent effects of a single low-dose administration of hydrocortisone (10 mg oral) on cognition in 36 HIV-infected women. Participants were first randomized to LDH or placebo and then received the opposite treatment one month later. Cognitive performance was assessed 30 minutes and 4 hours after pill administration to assess, respectively nongenomic and genomic effects. Self-reported stress/anxiety and salivary cortisol were assessed throughout sessions. LDH significantly increased salivary cortisol levels versus placebo; levels returned to baseline 4-hours post-administration. At the 30-minute assessment, LDH enhanced verbal learning and delayed memory, working memory, behavioral inhibition, and visuospatial abilities. At the 4-hour assessment, LDH enhanced verbal learning and delayed memory compared to placebo. LDH-induced cognitive benefits related to reductions in cytokines and to a lesser extent to increases in cortisol. The extended benefits from 30 minutes to 4 hours of a single administration of LDH on learning and delayed memory suggest that targeting the HPA axis may have potential clinical utility in HIV-infected women. These findings contrast with our findings in HIV-infected men who showed improved learning only at the 30-minute assessment. Larger, longer-term studies are underway to verify possible cognitive enhancing effects of LDH and the clinical significance of these effects in HIV.

Cross-infection and infection control in dentistry: Knowledge, attitude and practice of patients attended dental clinics in King Abdulaziz University Hospital, Jeddah, Saudi Arabia.

PubMed

Ibrahim, Nahla K; Alwafi, Hebah A; Sangoof, Samaa O; Turkistani, Asraa K; Alattas, Bushra M

The objective of the study was to determine the level of Knowledge, Attitude and Practice (KAP) of patients attended dental clinics at King Abdulaziz University Hospital (KAUH) regarding cross infections and infection control in dentistry. A cross-sectional study was conducted among 225 patients who attended the dental clinics of KAUH, Jeddah, Saudi Arabia, 2014. A standardized, confidential, anonymous, interviewing questionnaire was used. Knowledge about dental infections was assessed by 12 MCQs. The attitudes were assessed through answering seven statements on a three- point Likert scale. Patients' self reported practices were also evaluated. Descriptive and inferential statistics were done. Results of the study revealed that 39.5%, 38.7% and 21.8% of the participants obtained poor, fair and satisfactory level of knowledge about infections and infection control in dentistry, respectively. Social media was the commonest source of information about dental infection. Participant's educational level was significantly associated with the level of knowledge about dental infection. Patients had positive attitudes towards infection control in dentistry. Regarding self-reported practice, only few participants would ask dentists about sterilization of dental instruments (9.3%), wearing face mask (13.3%) and gloves (16.4%) if they don't do so. In conclusion, our participants had good attitudes towards infection control in dentistry. However, their knowledge and practice need improvements. Conduction of educational programs is needed through social media, mass media, schools and public places. These programs involve both patients and providers. Copyright © 2016 King Saud Bin Abdulaziz University for Health Sciences. Published by Elsevier Ltd. All rights reserved.

Frequency and Pathological Phenotype of Bovine Astrovirus CH13/NeuroS1 Infection in Neurologically-Diseased Cattle: Towards Assessment of Causality.

PubMed

Selimovic-Hamza, Senija; Boujon, Céline L; Hilbe, Monika; Oevermann, Anna; Seuberlich, Torsten

2017-01-18

Next-generation sequencing (NGS) has opened up the possibility of detecting new viruses in unresolved diseases. Recently, astrovirus brain infections have been identified in neurologically diseased humans and animals by NGS, among them bovine astrovirus (BoAstV) CH13/NeuroS1, which has been found in brain tissues of cattle with non-suppurative encephalitis. Only a few studies are available on neurotropic astroviruses and a causal relationship between BoAstV CH13/NeuroS1 infections and neurological disease has been postulated, but remains unproven. Aiming at making a step forward towards assessing the causality, we collected brain samples of 97 cases of cattle diagnosed with unresolved non-suppurative encephalitis, and analyzed them by in situ hybridization and immunohistochemistry, to determine the frequency and neuropathological distribution of the BoAstV CH13/NeuroS1 and its topographical correlation to the pathology. We detected BoAstV CH13/NeuroS1 RNA or proteins in neurons throughout all parts of the central nervous system (CNS) in 34% of all cases, but none were detected in cattle of the control group. In general, brain lesions had a high correlation with the presence of the virus. These findings show that a substantial proportion of cattle with non-suppurative encephalitis are infected with BoAstV CH13/NeuroS1 and further substantiate the causal relationship between neurological disease and astrovirus infections.

Frequency and Pathological Phenotype of Bovine Astrovirus CH13/NeuroS1 Infection in Neurologically-Diseased Cattle: Towards Assessment of Causality

PubMed Central

Selimovic-Hamza, Senija; Boujon, Céline L.; Hilbe, Monika; Oevermann, Anna; Seuberlich, Torsten

2017-01-01

Next-generation sequencing (NGS) has opened up the possibility of detecting new viruses in unresolved diseases. Recently, astrovirus brain infections have been identified in neurologically diseased humans and animals by NGS, among them bovine astrovirus (BoAstV) CH13/NeuroS1, which has been found in brain tissues of cattle with non-suppurative encephalitis. Only a few studies are available on neurotropic astroviruses and a causal relationship between BoAstV CH13/NeuroS1 infections and neurological disease has been postulated, but remains unproven. Aiming at making a step forward towards assessing the causality, we collected brain samples of 97 cases of cattle diagnosed with unresolved non-suppurative encephalitis, and analyzed them by in situ hybridization and immunohistochemistry, to determine the frequency and neuropathological distribution of the BoAstV CH13/NeuroS1 and its topographical correlation to the pathology. We detected BoAstV CH13/NeuroS1 RNA or proteins in neurons throughout all parts of the central nervous system (CNS) in 34% of all cases, but none were detected in cattle of the control group. In general, brain lesions had a high correlation with the presence of the virus. These findings show that a substantial proportion of cattle with non-suppurative encephalitis are infected with BoAstV CH13/NeuroS1 and further substantiate the causal relationship between neurological disease and astrovirus infections. PMID:28106800

Hyperammonemia in Urinary Tract Infections.

PubMed

Kenzaka, Tsuneaki; Kato, Ken; Kitao, Akihito; Kosami, Koki; Minami, Kensuke; Yahata, Shinsuke; Fukui, Miho; Okayama, Masanobu

2015-01-01

The present study investigated the incidence of hyperammonemia in urinary tract infections and explored the utility of urinary obstruction relief and antimicrobial administration to improve hyperammonemia. This was an observational study. Subjects were patients who were diagnosed with urinary tract infection and hospitalized between June 2008 and June 2009. We measured plasma ammonia levels on admission in patients who were clinically diagnosed with urinary tract infection and hospitalized. We assessed each patient's level of consciousness on admission using the Glasgow Coma Scale (GCS) and performed urine and blood cultures. We also assessed hearing prior to hospitalization using the Eastern Cooperative Oncology Group performance status (ECOG-PS). In cases with high ammonia levels on admission, plasma ammonia and GCS were measured 24 hours and 5-7 days later. Sixty-seven candidates were enrolled; of these, 60 cases (89.6%) with bacterial cell counts ≥10(4) CFU/mL were studied. Five cases (8.3%) presented with high plasma ammonia levels. Cases with hyperammonemia were significantly more likely to present with low GCS scores and urinary retention rate. All five cases received antimicrobial therapy with an indwelling bladder catheter to relieve urinary retention. The case 5 patient died shortly after admission due to complicated aspiration pneumonia; in the remaining cases, plasma ammonia levels were rapidly normalized and the level of consciousness improved. The occurrence of hyperammonemia in urinary tract infections is not rare. The cause of hyperammonemia is urinary retention obstruction. Therefore, along with antimicrobial administration, relief of obstruction is important for the treatment of hyperammonemia caused by this mechanism.

Ten questions on prosthetic shoulder infection

PubMed Central

Pinder, Elizabeth M; Ong, Joshua CY; Bale, R Stephen

2016-01-01

Prosthetic shoulder infection can cause significant morbidity secondary to pain and stiffness. Symptoms may be present for years before diagnosis because clinical signs are often absent and inflammatory markers may be normal. An emerging common culprit, Propionibacterium acnes, is hard to culture and so prolonged incubation is necessary. A negative culture result does not always exclude infection and new synovial fluid biochemical markers such as α defensin are less sensitive than for lower limb arthroplasty. A structured approach is necessary when assessing patients for prosthetic shoulder joint infection. This includes history, examination, serum inflammatory markers, plain radiology and aspiration and/or biopsy. A classification for the likelihood of prosthetic shoulder infection has been described based on culture, pre-operative and intra-operative findings. Treatment options include antibiotic suppression, debridement with component retention, one-stage revision, two-stage revision and excision arthroplasty. Revision arthroplasty is associated with the best outcomes. PMID:27583013

Ten questions on prosthetic shoulder infection.

PubMed

Pinder, Elizabeth M; Ong, Joshua Cy; Bale, R Stephen; Trail, Ian A

2016-07-01

Prosthetic shoulder infection can cause significant morbidity secondary to pain and stiffness. Symptoms may be present for years before diagnosis because clinical signs are often absent and inflammatory markers may be normal. An emerging common culprit, Propionibacterium acnes, is hard to culture and so prolonged incubation is necessary. A negative culture result does not always exclude infection and new synovial fluid biochemical markers such as α defensin are less sensitive than for lower limb arthroplasty. A structured approach is necessary when assessing patients for prosthetic shoulder joint infection. This includes history, examination, serum inflammatory markers, plain radiology and aspiration and/or biopsy. A classification for the likelihood of prosthetic shoulder infection has been described based on culture, pre-operative and intra-operative findings. Treatment options include antibiotic suppression, debridement with component retention, one-stage revision, two-stage revision and excision arthroplasty. Revision arthroplasty is associated with the best outcomes.

Frequently Asked Questions about Surgical Site Infections

MedlinePlus

... Personnel PPE Training Infection Control Assessment Tools Water Management Programs Map: HAI Prevention Activities Research CDC Supported Projects Prevention Epicenters (PE) Healthcare Safety Research (SHEPheRD) Environmental ...

Healthcare-Associated Infections (HAIs) Data and Statistics

MedlinePlus

... Personnel PPE Training Infection Control Assessment Tools Water Management Programs Map: HAI Prevention Activities Research CDC Supported Projects Prevention Epicenters (PE) Healthcare Safety Research (SHEPheRD) Environmental ...

Assessment of the types of catheter infectivity caused by Candida species and their biofilm formation. First study in an intensive care unit in Algeria

PubMed Central

Seddiki, Sidi Mohammed Lahbib; Boucherit-Otmani, Zahia; Boucherit, Kebir; Badsi-Amir, Souad; Taleb, Mourad; Kunkel, Dennis

2013-01-01

Nosocomial candidiasis remains a potential risk in intensive care units (ICUs), wherein Candida albicans is most responsible for its occurrence. Equally, non-C. albicans species, especially C. glabrata, are also involved. These infections are frequently associated with biofilms that contaminate medical devices, such as catheters. These biofilms constitute a significant clinical problem, and cause therapeutic failures, because they can escape the immune response and considerably decrease sensitivity to antifungal therapy. The diagnosis of catheter-related candidiasis is difficult; however, the differentiation between an infection of the catheter (or other medical implant) and a simple contamination is essential to start an antifungal treatment. Among the methods used for this type of study is the Brun-Buisson method, but this method only examines the infectivity of catheters caused by bacteria. For this reason, we wanted to adapt this method to the yeast cells of Candida spp. To assess the various types of infectivity of catheters (contamination, colonization, or infection) and their corresponding rates, as well as the responsible yeast species, we conducted our study, between February 2011 and January 2012, in the ICU at the University Hospital Center of Sidi Bel Abbes, Algeria; during this study, we took photographic images of the tongue of one patient and of that patient’s implanted orobronchial catheter. In addition, catheters contaminated by C. albicans biofilms were observed by scanning electron microscopy. PMID:23345986

Assessment of the QuantiFERON-TB Gold In-Tube test for the detection of Mycobacterium tuberculosis infection in United States Navy recruits.

PubMed

Lempp, Jason M; Zajdowicz, Margan J; Hankinson, Arlene L; Toney, Sean R; Keep, Lisa W; Mancuso, James D; Mazurek, Gerald H

2017-01-01

Immunologic tests such as the tuberculin skin test (TST) and QuantiFERON®-TB Gold In-Tube test (QFT-GIT) are designed to detect Mycobacterium tuberculosis infection, both latent M. tuberculosis infection (LTBI) and infection manifesting as active tuberculosis disease (TB). These tests need high specificity to minimize unnecessary treatment and high sensitivity to allow maximum detection and prevention of TB. Estimate QFT-GIT specificity, compare QFT-GIT and TST results, and assess factor associations with test discordance among U.S. Navy recruits. Among 792 subjects with completed TST and QFT-GIT, 42(5.3%) had TST indurations ≥10mm, 23(2.9%) had indurations ≥15mm, 14(1.8%) had positive QFT-GIT results, and 5(0.6%) had indeterminate QFT-GITs. Of 787 subjects with completed TST and determinate QFT-GIT, 510(64.8%) were at low-risk for infection, 277(35.2%) were at increased risk, and none had TB. Among 510 subjects at low-risk (presumed not infected), estimated TST specificity using a 15mm cutoff, 99.0% (95%CI: 98.2-99.9%), and QFT-GIT specificity, 98.8% (95%CI: 97.9-99.8%), were not significantly different (p>0.99). Most discordance was among recruits at increased risk of infection, and most was TST-positive but QFT-GIT-negative discordance. Of 18 recruits with TST ≥15mm but QFT-GIT negative discordance, 14(78%) were at increased risk. TB prevalence in country of birth was the strongest predictor of positive TST results, positive QFT-GIT results, and TST-positive but QFT-GIT-negative discordance. Reactivity to M. avium purified protein derivative (PPD) was associated with positive TST results and with TST-positive but QFT-GIT-negative discordance using a 10 mm cutoff, but not using a 15 mm cutoff or with QFT-GIT results. M. tuberculosis infection prevalence was low, with the vast majority of infection occurring in recruits with recognizable risks. QFT-GIT and TST specificities were high and not significantly different. Negative QFT-GIT results among subjects

[Parvovirus B19 infection after kidney transplantation].

PubMed

Brodin-Sartorius, Albane; Mekki, Yahia; Bloquel, Bénédicte; Rabant, Marion; Legendre, Christophe

2012-02-01

Prevalence for human parvovirus B19 infection is estimated to be between 2% and 30% in renal transplant recipients. In post-transplant settings, parvovirus B19 infection may occur either as a primary infection or a reactivation. Parvovirus transmission most commonly occurs through respiratory tract but may also result from graft or blood packs contamination. Co-infections with HHV-6 and CMV viruses are frequent. The hallmark symptom is anemia, more rarely pancytopenia and hemophagocytic syndrome. In respect to renal involvement, parvovirus B19 infection has been associated with graft dysfunction in 10% of cases. Both thrombotic microangiopathies and collapsing glomerulopathies have been reported concomitantly with parvovirus B19 infection but the causal link remains unclear. Other complications are seldomly reported, including hepatitis, encephalitis, and myocarditis. Diagnosis is based on pre and post-transplant serological status. In addition, the management of parvovirus B19 infection in immunocompromised patients requires quantitative assessment of blood viral load by PCR. The treatment relies primarily on reduction of immunosuppression combined with intravenous immunoglobulin infusions. Relapses occur in 30% of cases. Copyright © 2011 Association Société de néphrologie. Published by Elsevier SAS. All rights reserved.

Surveying Cystic Fibrosis Care Centers to Assess Adoption of Infection Prevention and Control Recommendations.