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1.
The sensitivity and resistance of some Gram-negative mercury (Hg2+)-sensitive and-resistant strains to chemotherapeutic agents and to disinfectants and preservatives are described.Escherichia coli andPseudomonas aeruginosa strains harboring plasmid pUB 1351 [pUB 367:Tn 501] andE. coli bearing R100-1 were resistant to inorganic mercury and to various antibiotics, but were not more resistant to organic mercury and other preservatives and disinfectants than plasmidless strains. 相似文献
2.
The sensitivity of strains ofEscherichia coli, with and without the RP1 R-factor, to antibiotics and other antibacterial agents has been studied. RP1+ strains ofE. coli were resistant to kanamycin, carbenicillin, and tetracycline, resistance to the first two antibiotics being produced by destruction
of the drugs. This resistance could be transferred to two strains ofPseudomonas aeruginosa. The parent strain ofE. coli UB 1005, its two mutant strains (DC2 and DC3), and two of the strains with the RP1 R-factor showed a similar order of sensitivity
to phenylmercuric nitrate, chlorhexidine, thiomersal, and mercuric chloride.E. coli strains DC2 and DC2 (RP1+) were the most sensitive to benzalkonium chloride and cetrimide. RP1+ strains were more resistant than RP1− strains to lysozyme-ethylenediaminetetraacetic acid, but treatment of the former strains with acriflavine rendered the cells
more sensitive to the lytic system. There was no evidence thatP. aeruginosa (RP1+) strains possessed increased resistance to polymyxin or to disinfectants, although they became somewhat less sensitive to
lysozyme-ethylenediaminetetraacetic acid. 相似文献
3.
Uche V. Amazigo Stephen G. A. Leak Honorat G. M. Zoure Chukwu Okoronkwo Maimouna Diop Ly Sunday Isiyaku Andy Crump Joseph C. Okeibunor Boakye Boatin 《PLoS neglected tropical diseases》2021,15(3)
The neglected tropical diseases (NTDs) affect hundreds of millions of people, predominantly in rural, often difficult-to-access areas, poorly served by national health services. Here, we review the contributions of 4.8 million community-directed distributors (CDDs) of medicines over 2 decades in 146,000 communities in 27 sub-Saharan African countries to control or eliminate onchocerciasis and lymphatic filariasis (LF). We examine their role in the control of other NTDs, malaria, HIV/AIDS interventions, immunisation campaigns, and support to overstretched health service personnel. We are of the opinion that CDDs as community selected, trained, and experienced “foot soldiers,” some of whom were involved in the Ebola outbreak responses at the community level in Liberia, if retrained, can assist community leaders and support health workers (HWs) in the ongoing Coronavirus Disease 2019 (COVID-19) crisis. The review highlights the improved treatment coverage where there are women CDDs, the benefits and lessons from the work of CDDs, their long-term engagement, and the challenges they face in healthcare delivery. It underscores the value of utilising the CDD model for strong community engagement and recommends the model, with some review, to hasten the achievement of the NTD 2030 goal and assist the health system cope with evolving epidemics and other challenges. We propose that, based on the unprecedented progress made in the control of NTDs directly linked to community engagement and contributions of CDDs “foot soldiers,” they deserve regional and global recognition. We also suggest that the World Health Organization (WHO) and other international stakeholders promote policy and guidance for countries to adapt this model for the elimination of NTDs and to strengthen national health services. This will enhance the accomplishment of some Sustainable Development Goals (SDGs) by 2030 in sub-Saharan Africa. 相似文献
4.
Michelle J. Boyle Prasanna Jagannathan Lila A. Farrington Ijeoma Eccles-James Samuel Wamala Tara I McIntyre Hilary M. Vance Katherine Bowen Felistas Nankya Ann Auma Mayimuna Nalubega Esther Sikyomu Kate Naluwu John Rek Agaba Katureebe Victor Bigira James Kapisi Jordan Tappero Mary K Muhindo Bryan Greenhouse Emmanuel Arinaitwe Grant Dorsey Moses R. Kamya Margaret E. Feeney 《PLoS pathogens》2015,11(7)
FoxP3+ regulatory CD4 T cells (Tregs) help to maintain the delicate balance between pathogen-specific immunity and immune-mediated pathology. Prior studies suggest that Tregs are induced by P. falciparum both in vivo and in vitro; however, the factors influencing Treg homeostasis during acute and chronic infections, and their role in malaria immunopathogenesis, remain unclear. We assessed the frequency and phenotype of Tregs in well-characterized cohorts of children residing in a region of high malaria endemicity in Uganda. We found that both the frequency and absolute numbers of FoxP3+ Tregs in peripheral blood declined markedly with increasing prior malaria incidence. Longitudinal measurements confirmed that this decline occurred only among highly malaria-exposed children. The decline of Tregs from peripheral blood was accompanied by reduced in vitro induction of Tregs by parasite antigen and decreased expression of TNFR2 on Tregs among children who had intense prior exposure to malaria. While Treg frequencies were not associated with protection from malaria, there was a trend toward reduced risk of symptomatic malaria once infected with P. falciparum among children with lower Treg frequencies. These data demonstrate that chronic malaria exposure results in altered Treg homeostasis, which may impact the development of antimalarial immunity in naturally exposed populations. 相似文献
5.
Norovirus proteinase-polymerase and polymerase are both active forms of RNA-dependent RNA polymerase
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Belliot G Sosnovtsev SV Chang KO Babu V Uche U Arnold JJ Cameron CE Green KY 《Journal of virology》2005,79(4):2393-2403
In vitro mapping studies of the MD145 norovirus (Caliciviridae) ORF1 polyprotein identified two stable cleavage products containing the viral RNA-dependent RNA polymerase (RdRp) domains: ProPol (a precursor comprised of both the proteinase and polymerase) and Pol (the mature polymerase). The goal of this study was to identify the active form (or forms) of the norovirus polymerase. The recombinant ProPol (expressed as Pro(-)Pol with an inactivated proteinase domain to prevent autocleavage) and recombinant Pol were purified after synthesis in bacteria and shown to be active RdRp enzymes. In addition, the mutant His-E1189A-ProPol protein (with active proteinase but with the natural ProPol cleavage site blocked) was active as an RdRp, confirming that the norovirus ProPol precursor could possess two enzymatic activities simultaneously. The effects of several UTP analogs on the RdRp activity of the norovirus and feline calicivirus Pro(-)Pol enzymes were compared and found to be similar. Our data suggest that the norovirus ProPol is a bifunctional enzyme during virus replication. The availability of this recombinant ProPol enzyme might prove useful in the development of antiviral drugs for control of the noroviruses associated with acute gastroenteritis. 相似文献
6.
Qu X Khutoryanskiy VV Stewart A Rahman S Papahadjopoulos-Sternberg B Dufes C McCarthy D Wilson CG Lyons R Carter KC Schätzlein A Uchegbu IF 《Biomacromolecules》2006,7(12):3452-3459
Amphiphilic chitosan-based polymers (Mw < 20 kDa) self-assemble in aqueous media at low micromolar concentrations to give previously unknown micellar clusters of 100-300 nm in size. Micellar clusters comprise smaller 10-30 nm aggregates, and the nanopolarity/drug incorporation efficiency of their hydrophobic domains can be tailored by varying the degree of lipidic derivatization and molecular weight of the carbohydrate. The extent of drug incorporation by these novel micellar clusters is 1 order of magnitude higher than is seen with triblock copolymers, with molar polymer/drug ratios of 1:48 to 1:67. On intravenous injection, the pharmacodynamic activity of a carbohydrate propofol formulation is increased by 1 order of magnitude when compared to a commercial emulsion formulation, and on topical ocular application of a carbohydrate prednisolone formulation, initial drug aqueous humor levels are similar to those found with a 10-fold dose of prednisolone suspension. 相似文献
7.
Anukam Kingsley C. Osazuwa Emmanuel E. Mbata Theodore I. Ahonkhai Ijeoma N. 《World journal of microbiology & biotechnology》2004,20(3):231-234
We investigated 296 adolescents (11–18 years), who had been immunized previously with the three doses of DPT vaccines. 48
were diagnosed positive for HIV-1. Nasopharyngeal swabs were obtained from 296 adolescents who presented with persistent cough
and nasopharyngeal secretions. Nasopharyngeal swabs (calcium alginate) specimens were collected by passing the swabs through
the nares into the posterior nasopharynx and rotating the swabs for a few seconds. The swabs were plated for culture of Bordetella organisms in charcoal cephalexin blood agar (CCBA). The CCBA plates were incubated for 2–6 days at 35 °C in a humid aerobic
atmosphere. The suspected, shiny (mercury-like) colonies were tested by slide agglutination with antisera to B. pertussis and B. parapertussis, and urease, oxidase activities were performed. Results indicate that out of 48 HIV-1-positive adolescents, 18 had positive
cultures for Bordetella organisms (14, Bordetella pertussis, and 4, Bordetella parapertussis). Of 248 HIV-1-negative subjects, 3 had Bordetella organisms (2, Bordetella pertussis, 1, Bordetella bronchiseptica). One of the subjects, a boy, aged 14 years, with Bordetella bronchiseptica had a dog as pet, which was found to be infected. The results indicate that adolescents with HIV-1 infection, despite being
vaccinated against pertussis have a higher rate of infection when exposed to pertussis bacteria than HIV-1-negative adolescents.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
8.
Fidelia Ijeoma Uche James McCullagh Timothy W.D. Claridge Alan Richardson Wen-Wu Li 《Bioorganic & medicinal chemistry letters》2018,28(9):1652-1656
Our previous studies demonstrated that cycleanine, a macrocyclic bisbenzylisoquinoline (BBIQ) alkaloid, showed potent anti-ovarian cancer activity via apoptosis induction. Here, we synthesized two novel (aminoalkyl)cycleanine analogues (2 and 3) through a simple and efficient two-step reaction starting from cycleanine isolated from Triclisia subcordata Oliv. These analogues showed greater potency than the unmodified cycleanine in three human ovarian cancer cell lines. Both 2 and 3 induced apoptosis in ovarian cancer cells by activations of caspases 3/7, cleavage of PARP, increase in subG1 cell cycle phase and in the percentage of apoptotic cells. Further confocal fluorescence microscopy analysis confirmed the cellular uptake of alkaloids in ovarian cancer cells by using the unique (alkynyl)cycleanine (3) via click chemistry reaction. Our results suggest that cycleanine could be a hit compound for the future development in attacking ovarian cancer. 相似文献
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10.
Eneyi E. Kpokiri Elizabeth Chen Jingjing Li Sarah Payne Priyanka Shrestha Kaosar Afsana Uche Amazigo Phyllis Awor Jean-Francois de Lavison Saqif Khan Jana Mier-Alpao Alberto Ong Jr Shivani Subhedar Isabelle Wachmuth Luis Gabriel Cuervo Kala M. Mehta Beatrice Halpaap Joseph D. Tucker 《PLoS medicine》2021,18(9)