Rohani M.Y.,Institute for Medical Research |
Zin N.M.,Institute for Medical Research |
Hussin A.,Hospital Queen Elizabeth |
Nawi S.H.,Hospital Selayang |
And 15 more authors.
Vaccine | Year: 2011
From January 2008 to December 2009, 433 Streptococcus pneumoniae strains were examined to determine the serotype distribution and susceptibility to selected antibiotics. About 50% of them were invasive isolates. The strains were isolated from patients of all age groups and 33.55% were isolated from children below 5 years. The majority was isolated from blood (48.53%) and other sterile specimens (6.30%). Community acquired pneumonia (41.70%) is the most common diagnosis followed by sepsis (9.54%). Serotyping was done using Pneumotest Plus-Kit and antibiotic susceptibility pattern was determined by modified Kirby-Bauer disk diffusion method and measurement of minimum inhibitory concentration (MIC) using E-test strip. Ten most common serotypes were 19F (15.02%), 6B (10.62%), 19A (6.93%), 14 (6.70%), 1 (5.08%), 6A (5.08%), 23F (4.85%), 18C (3.93%), 3 (2.08%) and 5 (1.85%). Penicillin MIC ranged between ≤0.012-4μg/ml with MIC 90 of 1μg/ml. Penicillin resistant rate is 31.78%. The majority of penicillin less-susceptible strains belonged to serotype 19F followed by 19A and 6B. Based on the serotypes distribution 22 (44.00%), 28 (56.00%) and 39 (78.00%) of the invasive isolates from children ≤2 years were belonged to serotypes included in the PCV7, PCV10 and PCV13, respectively. © 2011 Elsevier Ltd.
Barbier F.,Bacteriology Unit |
Barbier F.,University Paris Diderot |
Ruppe E.,Bacteriology Unit |
Hernandez D.,University of Geneva |
And 14 more authors.
Journal of Infectious Diseases | Year: 2010
Background. Data on community spread of methicillin-resistant coagulase-negative staphylococci (MR-CoNS) are scarce. We assessed their potential role as a reservoir of staphylococcal cassette chromosome mec (SCCmec) IVa, the leading SCCmec subtype in community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA). Methods. Nasal carriage of MR-CoNS was prospectively investigated in 291 adults at hospital admission. MRCoNS were characterized by SCCmec typing, long-range polymerase chain reaction (PCR) for SCCmec IV, and multiple-locus variable-number tandem repeat analysis (MLVA) for Staphylococcus epidermidis (MRSE) strains. Three SCCmec IVa elements were fully sequenced. Results. The carriage rate of MR-CoNS was 19.2% (25.9% and 16.5% in patients with and patients without previous exposure to the health care system, respectively; P=.09). MR-CoNS strains (n=83, including 58 MRSE strains with highly heterogeneous MLVA patterns) carried SCCmec type IVa (n=9, all MRSE), other SCCmec IV subtypes (n=9, including 7 MRSE), other SCCmec types (n=15), and nontypeable SCCmec (n=50). Longrange PCR indicated structural homology between SCCmec IV in MRSE and that in MRSA. Complete sequences of SCCmec IVa from 3 MRSE strains were highly homologous to those available for CA-MRSA, including major clones USA300 and USA400. Conclusions. MR-CoNS are probably disseminated in the community, notably in subjects without previous exposure to the health care system. MRSE, the most prevalent species, may act as a reservoir of SCCmec IVa for CA-MRSA. © 2010 by the Infectious Diseases Society of America. All rights reserved.
Kovjazin R.,Vaxil BioTherapeutics Ltd |
Shitrit D.,Meir Medical Center |
Preiss R.,Maccabi Tuberculosis Center |
Haim I.,Maccabi Tuberculosis Center |
And 8 more authors.
Clinical and Vaccine Immunology | Year: 2013
The low protection by the bacillus Calmette-Guérin (BCG) vaccine and existence of drug-resistant strains require better anti- Mycobacterium tuberculosis vaccines with a broad, long-lasting, antigen-specific response. Using bioinformatics tools, we identified five 19- to 40-mer signal peptide (SP) domain vaccine candidates (VCs) derived from M. tuberculosis antigens. All VCs were predicted to have promiscuous binding to major histocompatibility complex (MHC) class I and II alleles in large geographic territories worldwide. Peripheral mononuclear cells (PBMC) from healthy naïve donors and tuberculosis patients exhibited strong proliferation that correlated positively with Th1 cytokine secretion only in healthy naïve donors. Proliferation to SP VCs was superior to that to antigen-matched control peptides with similar length and various MHC class I and II binding properties. Tcell lines induced to SP VCs from healthy naïve donors had increased CD44high/ CD62L+ activation/effector memory markers and gamma interferon (IFN-Υ), but not interleukin-4 (IL-4), production in both CD4+ and CD8+ T-cell subpopulations. T-cell lines from healthy naïve donors and tuberculosis patients also manifested strong, dose-dependent, antigen-specific cytotoxicity against autologous VC-loaded or M. tuberculosis-infected macrophages. Lysis of M. tuberculosis-infected targets was accompanied by high IFN-Υ secretion. Various combinations of these five VCs manifested synergic proliferation of PBMC from selected healthy naïve donors. Immunogenicity of the best three combinations, termed Mix1, Mix2, and Mix3 and consisting of 2 to 5 of the VCs, was then evaluated in mice. Each mixture manifested strong cytotoxicity against M. tuberculosis-infected macrophages, while Mix3 also manifested a VC-specific humoral immune response. Based on these results, we plan to evaluate the protection properties of these combinations as an improved tuberculosis subunit vaccine. © 2013, American Society for Microbiology.
Faure S.,Laboratory for the Research and Investigation of Veterinary Drugs and Disinfectants |
Perrin-Guyomard A.,Laboratory for the Research and Investigation of Veterinary Drugs and Disinfectants |
Delmas J.M.,Laboratory for the Research and Investigation of Veterinary Drugs and Disinfectants |
Chatre P.,Bacteriology Unit |
Laurentie M.,Laboratory for the Research and Investigation of Veterinary Drugs and Disinfectants
Antimicrobial Agents and Chemotherapy | Year: 2010
Food animals are a potential source of CTX-M resistance genes for humans. We evaluated the transfer of the blaCTX-M-9 gene from an animal strain of Salmonella enterica serotype Virchow to Enterobacteriaceae of the human intestinal flora by using human flora-associated (HFA) rats with and without cefixime treatment. In the absence of antibiotic, no transconjugant enterobacteria were found in the feces of HFA rats. However, the transfer rate was high if Escherichia coli J5 recipient strains were coinoculated orally with Salmonella. S. enterica serotype Virchow persisted in the rat fecal flora both during and after treatment with therapeutic doses of cefixime. The drug did not increase the transfer rate, and E. coli J5 transconjugants were eliminated from the flora before the end of cefixime treatment. No cefixime was recovered in the rat feces. In the presence of recipient strains, the blaCTX-M-9 resistance gene was transferred from a strain of animal origin to the human intestinal flora, although transconjugant colonization was transient. Antibiotic use enhanced the persistence of donor strains, increasing the resistance gene pool and the risk of its spread. Copyright © 2010, American Society for Microbiology. All Rights Reserved.
Hamdan N.A.,Bacteriology Unit |
Issa R.,Bacteriology Unit |
Md Noh M.F.,Institute for Medical Research |
Zin N.M.,National University of Malaysia
Current Research in Tuberculosis | Year: 2012
The analysis of nucleic acids recognition using genosensor provides a rapid, sensitive and inexpensive detection for infectious and genetic diseases, bacteria food contaminations, forensic and environmental research. A simple application of electrochemical biosensor for the alternative detection of Mycobacterium tuberculosis (M. tuberculosis) using Pencil Graphite Electrode (PGE) and Methylene Blue (MB) as electroactive intercalators via non-covalent attachment was developed. Synthetic oligonucleotides of M. tuberculosis which consisted of M. Probe, M. Target, M. Non-complementary and M. Mutation were used for DNA hybridization detection on PGE. Differential Pulse Voltammetry (DPV) was performed using a PalmSens Electrochemical Portable Apparatus controlled by a Pocket PC. Various parameters affecting the response of the signals were explored and optimized including M. Probe concentration, immobilization time and hybridization time of immobilized M. Probe, concentration and accumulation time of MB, as well as the concentration of M. Target. The results obtained after measurement showed that the voltammetric signal of MB before hybridization was higher compared to after hybridization. This indicates that MB has high affinity towards guanine bases. Differences in the signals of MB for hybridization between M. Probes and Polymerase Chain Reaction (PCR) amplified products were observed. The Relative Standard Deviation (RSD) for TB PCR positive sample, TB PCR positive control, TB PCR negative sample, TB PCR negative control and TB PCR blank were 11.5, 2.9, 22.8, 13.8 and 20.3%, respectively which can be applied for the detection of M. tuberculosis. © 2012 Academic Journals Inc.