ABSTRACT
Polyamidoamine (PAMAM) dendrimers as synthetic gene vectors are efficient gene delivery systems. In this study, a kind of α-cyclodextrin-PAMAM conjugates polymer (CyD-G1) was synthesized as a gene delivery vector. Based on 1H NMR detectation, about 6.4 PAMAM-G1 molecules was grafted onto an α-CD core. Agarose gel electrophoresis revealed that CyD-G1 could efficiently bind with DNA to condense them into nano-scale particles, which showed a similar binding capacity of PEI-25K. Besides, it could protect DNA from DNase I degradation in a low N/P ratio. When N/P ratio in the CyD-G1/DNA polyplex was 40, the average particle size of CyD-G1/DNA polyplex was about 120 nm, and zeta potential was +21 mV. This polyplex could maintain its particle size in serum-containing solution within 360 min. In comparison with PEI-25K carrier, CyD-G1 showed low cytotoxicity in various cell lines. Cell transfection results showed that CyD-G1 efficiently delivered DNA into cells at N/P=80 compared with Lipofectamine 2000 and PEI-25K.Unlike Lipofectamine 2000 and PEI-25K, in serum-containing test condition, CyD-G1/DNA polyplex could maintain the transgene activities. The results of confocal laser scanning microscopy indicated that most DNA entered into cell nuclei within 4 h, and this phenomenon was consistent with the results calculated by flow cytometry. Taken together, CyD-G1 showed good transgene activities and the gene delivery vector could be used not only in vitro but also in vivo.
ABSTRACT
IntroductionKlebsiella spp is a well-known opportunistic pathogen associated with nosocomial infections such asurinary tract, septicaemia and pneumonia number of multi-drug resistant strains and infections causedby Klebsiella has progressively increased, causing treatment limitations.GoalIdentify of phenotype of Klebseilla isolates from ñlinical samplesMaterials and MethodsA total of 112 Klebsiella strains were isolated from clinical samples in State Central First Hospital and StateCentral Third Hospital from July 2015 through December 2015. The bacterial isolates were identifi edaccording to cultural characteristics, biochemical test and API20E. The serum resistance, capsule andhypermucoviscosity, cell surface protein (curly), a-hemolysin and ability to form biofi lm were sought byphenotypic assays. Antimicrobial susceptibility was tested by diffusion method.ResultA total of 112 Klebsiella samples were collected. The bacterial isolates were identifi ed according tocultural characteristics, biochemical test and API20E, the results revealed that 16.1 percent isolateswere identifi ed as K.oxytoca all of them 83.9 percent isolates were belong to K.pneumonia. Therewere observed for ampicillin (99 percent), nitrofurantoin (53.6 percent), cepalotin (50.6 percent) and51 percent of isolates were considered as a multiple drug resistant. Serum resistance properties ofK.pneumoniae was resistance 89.4 percent, intermediately susceptible 4.3 percent, sensitive 6.4percent and for K.oxytoca resistance 88.9 percent, intermediately susceptible 5.6 percent, sensitive 5.6percent. The hemolysin àalpha was detected in 32.2 percent, and gamma, beta in 66.96 percent, 0.9percent respectively. The capsule was observed in 46.5 percent and hypermucoviscosity in 27.7 percentof isolates. The cell surface protein (curly) and biofi lm were detected in 100 percent.Conclusion:Both K.pneumoniae and K.oxytoca isolates from clinical samples have similar virulent properties, andthe a-hemolysin and hypermucoviscosity positive isolates were more resistance to antibiotics.
ABSTRACT
The bacterial strains that cause symptomatic urinary tract infections possess diverse distinctive properties that enable them to overcome the local host defences. In Escherichia coli, virulence results from the cumulative impact of several virulence factors, which can vary according to the patient populations. The study was undertaken to assess the prevalence of the virulence factors by phenotypic assays in the E. coli isolates which were isolated from patients with UTI from a tertiary care hospital in Kerala. Methods: A total of 300 E. coli isolates were obtained from symptomatic cases of urinary tract infections and 30 E. coli faecal isolates were obtained from apparently healthy individuals and they were tested for phenotypic properties like haemolysin production, mannose resistant hemagglutination to indicate P fimbriae, cell surface hydrophobicity. Results: Among the 300 E. coli isolates from the cases group, 135 (43.5%) were hemolytic, 106 (35.5%) were MRHA positive, 123 (41%) were hydrophobic. Among the 30 controls, 2 (6%) were hemolytic, 02 (6%) were MRHA positive and 04 (10%) were hydrophobic. The difference between the cases and the control group was significant (P <0.001). Multiple virulence factors were observed in 51% of the isolates. Conclusion: The present study showed varied phenotypic expression of the virulence factors in the urinary isolates as compared to the fecal isolates.
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Objective To explore the possible causes that result in serum-resistance of patients with syphilis. Methods Cerebrospinal fluid(CSF) routine and biochemistry, RPR, TPPA, and immunological function in 25 patients with syphilis serum-resistance were detected after giving the standard therapy, and radiographic examination of multiple internal organs was performed as well. All patients were treated with 24 million units of Penicillin G per day by intravenous drip for 14 days followed by muscle injection of Bicillin 2.4 million units weekly for 3 weeks after leaving hospital. Blood serum RPR was reexamined 3 and 6 months after treatment, respectively. Results Among 25 patients CSF-TPPA was positive in 11 cases, all patients' CSF-RPR were negative, CSF-WBC and CSF-Pr increased in 7 patients, serum IgM level increased and C3 decreased in 10 cases (40%), and CD_3+CD_8+ cell count increased and NK cell count decreased in 21 cases (84%). The regurgitation of bicuspid valve, tricuspid valve and aortic value was found in 3 patients. The RPR titers in all patients did not decrease after treatment according to neurosyphlis. Conclusion Asymptomatic neurosyphilis and immune disorder may be causes of serum-resistance of syphilis.
ABSTRACT
Human African trypanosomiasis is caused by the infection of Trypanosoma brucei gambiense or T.b. rhodesiense, while another morphologically identical subspecies, T.b.brucei, and other closely related species, T.equiper-dum and T.evansi, are considered not infectious to human. This is highly related to the trypanosome lytic factor (TLF) found in normal human serum (NHS) and the serum resistance-associated (SRA) protein of trypanosomes infectious to human. We reviewed the research progress in TLF and its role in trypanosome lysis as well as the mechanism of SRA against the TLF.