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المصدر: Asian Biomedicine. 4:631-635
مصطلحات موضوعية: Iron Chelator, Siderophore, biology, Pseudomonas aeruginosa, Geography, Planning and Development, Management, Monitoring, Policy and Law, medicine.disease_cause, Dialysis tubing, Microbiology, Ferritin, Deferoxamine, 03 medical and health sciences, 0302 clinical medicine, biology.protein, medicine, Chelation, 030212 general & internal medicine, 030217 neurology & neurosurgery, Iron acquisition, medicine.drug
الوصف: Background: Siderophore is an iron chelator produced by microorganism. Pseudomonas aeruginosa produces two siderophores (pyoverdin and pyochelin). Desferrioxamine is a siderophore used in thalassemia patients to treat an iron overload of vital organs. Objective: Compare the ability of pyoverdin, pyochelin, and desferrioxamine for iron mobilization from ferritin. Materials and Methods: In vitro experiment, the ability of P. aeruginosa siderophores and desferrioxamine for iron mobilization from ferritin was compared by using a dialysis membrane assay at pH values of 7.4 and 6.0. Stimulation of P. aeruginosa PAO1 growth by all siderophores was studied in glucose minimum medium. Results: All three compounds were capable of iron mobilization at both pHs. At pH 6.0, the most effectiveness compound was desferrioxamine (31.6%), followed by pyoverdin (21.5%) and pyochelin (13.7%) compared on weight basis, each at 10 μg/mL. At equimolar concentration, their activities were desferrioxamine (38.5±1.2%), followed by pyoverdin (32.0±4.8%) and pyochelin (26.7±1.9%), respectively. Conclusion: The most effective compound in iron mobilization from ferritin was desferrioxamine, followed by pyoverdin and pyochelin respectively.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_________::b302cfd0ae2f6e12c7f6df86251f48acTest
https://doi.org/10.2478/abm-2010-0080Test -
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المؤلفون: Makoto Ohnishi, Shu Ichi Nakayama, Magnus Unemo, Somporn Srifuengfung, Ken Shimuta, Sasiprapa Prombhul, Chanwit Tribuddharat
مصطلحات موضوعية: Internationality, Population, Drug resistance, Microbial Sensitivity Tests, Biology, medicine.disease_cause, Polymerase Chain Reaction, beta-Lactam Resistance, beta-Lactamases, Microbiology, Epidemiology and Surveillance, Gonorrhea, Plasmid, Japan, medicine, Humans, Pharmacology (medical), Typing, education, Pharmacology, education.field_of_study, Molecular Epidemiology, Molecular epidemiology, Penicillinase, Thailand, Neisseria gonorrhoeae, Anti-Bacterial Agents, Cephalosporins, Penicillin, Infectious Diseases, Mutation, Multilocus sequence typing, Public Health, medicine.drug, Plasmids
الوصف: Neisseria gonorrhoeae is a major public health problem globally, especially because the bacterium has developed resistance to most antimicrobials introduced for first-line treatment of gonorrhea. In the present study, 96 N. gonorrhoeae isolates with high-level resistance to penicillin from 121 clinical isolates in Thailand were examined to investigate changes related to their plasmid-mediated penicillin resistance and their molecular epidemiological relationships. A β-lactamase (TEM) gene variant, bla TEM-135 , that may be a precursor in the transitional stage of a traditional bla TEM-1 gene into an extended-spectrum β-lactamase (ESBL), possibly causing high resistance to all extended-spectrum cephalosporins in N. gonorrhoeae , was identified. Clonal analysis using multilocus sequence typing (MLST) and N. gonorrhoeae multiantigen sequence typing (NG-MAST) revealed the existence of a sexual network among patients from Japan and Thailand. Molecular analysis of the bla TEM-135 gene showed that the emergence of this allele might not be a rare genetic event and that the allele has evolved in different plasmid backgrounds, which results possibly indicate that it is selected due to antimicrobial pressure. The presence of the bla TEM-135 allele in the penicillinase-producing N. gonorrhoeae population may call for monitoring for the possible emergence of ESBL-producing N. gonorrhoeae in the future. This study identified a bla TEM variant ( bla TEM-135 ) that is a possible intermediate precursor for an ESBL, which warrants international awareness.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::55cf380a6e6634a62569b1085e7758adTest
https://europepmc.org/articles/PMC3264274Test/ -
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المؤلفون: Somporn, Srifuengfung, Kulkanya, Chokephaibulkit, Chanwit, Tribuddharat, Sopita, Comerungsee
المصدر: Journal of the Medical Association of Thailand = Chotmaihet thangphaet. 93
مصطلحات موضوعية: Adult, Aged, 80 and over, Male, Adolescent, Infant, Middle Aged, Thailand, Drug Resistance, Multiple, Pneumococcal Infections, Hospitals, University, Young Adult, Age Distribution, Streptococcus pneumoniae, Anti-Infective Agents, Disk Diffusion Antimicrobial Tests, Child, Preschool, Humans, Female, Sex Distribution, Child, Sentinel Surveillance, Aged
الوصف: Streptococcus pneumoniae was isolated from 170 patient specimens at Siriraj Hospital during January-December 2008. Patients were 66% male and ranged in age from 3 months to 94 years (mean +/- SD = 38.2 +/- 31.7). The largest proportion (29.4%) of isolates were from patients older than 60 years, followed by patients aged 2-5 years (20%) and from patients less than 2 years (12.4%). Monthly isolation was highest in December (22 isolates in December compared to the average of 13 isolates of the other months). Antimicrobial susceptibility for eight drugs was determined by the disk diffusion method. Overall, susceptibility was generally high to chloramphenicol (71.8%), linezolid (100%), ofloxacin (93.5%) and vancomycin (100%), but less susceptible to erythromycin (35.3%), penicillin (31.1%), tetracycline (28.8%) and trimethoprim/ sulfamethoxazole (24.1%). Among the 105 (62%) isolates resistant to three or more drugs, the most common resistance pattern was erythromycin-penicillin-tetracycline-trimethoprim/sulfamethoxazole, accounting for 39% of such isolates, followed by chloramphenicol-erythromycin-penicillin-tetracycline- trimethoprim/sulfamethoxazole (29.5%). The minimal inhibitory concentrations (MIC) of penicillin and cefotaxime were determined by broth microdilution. By 2008 CLSI criteria, 92% and 90% of 51 sterile site isolates were penicillin and cefotaxime susceptible, including one of two meningitis cases. In contrast, of 26 non-sterile site isolates, only 26.9% and 76.9% were susceptible to penicillin and cefotaxime, respectively. The MICs of penicillin were higher for isolates from non-sterile sites than for those from sterile sites.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=pmid________::33ffbe9d43341304c6965f391e138882Test
https://pubmed.ncbi.nlm.nih.gov/21294379Test -
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المصدر: Journal of the Medical Association of Thailand = Chotmaihet thangphaet. 93
مصطلحات موضوعية: Base Sequence, Genotype, Penicillin Resistance, Molecular Sequence Data, Gene Amplification, Cefotaxime, Microbial Sensitivity Tests, Penicillins, Aminoacyltransferases, Thailand, Polymerase Chain Reaction, Anti-Bacterial Agents, Streptococcus pneumoniae, Bacterial Proteins, Genes, Bacterial, Mutation, Humans, Penicillin-Binding Proteins, Amino Acid Sequence
الوصف: Penicillin resistance in Streptococcus pneumoniae isolates results from altered penicillin-binding proteins (PBPs), especially PBP2, which has a reduced affinity to penicillin. This study evaluated drug resistance and the gene sequence of the conserved motif pbp2b of penicillin-resistant isolates in Thailand.Penicillin-resistant pneumococci with minimum inhibitory concentrations (MIC) for penicillinor = microg/ ml and penicillin-susceptible strains were identified from clinical specimens. The pbp2b genes were amplified by polymerase chain reaction (PCR), and the purified PCR product was cloned into E. coli. The recombinant plasmid clones containing pbp2b were sequenced and evaluated for mutations corresponding to penicillin and cefotaxime resistance.Penicillin-susceptible S. pneumoniae isolates were susceptible to 12 other antibiotics tested (range 95-100%) while penicillin-nonsusceptible isolates were resistant to most antibiotics except amoxicillin/clavulanate and levofloxacin. Sequence analysis of pbp2b showed a substitution of A for T451 next to the region of the SSN triad in all six resistant isolates tested and mutations clustered around the KTG triad in two isolates. Using the ClustalW alignment program, Thai isolates differed from those of European countries, but were more similar to those from Japan than Korea.Penicillin or cefotaxime resistance in S. pneumoniae in Thailand was due to affinity reduction of PBP2b, similar to changes found in other Asian isolates.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=pmid________::d633aa64700fd07053e6d87d741000f6Test
https://pubmed.ncbi.nlm.nih.gov/21294378Test -
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المؤلفون: Somporn, Srifuengfung, Chanwit, Tribuddharat, Kulkanya, Chokephaibulkit, Sopita, Comerungsee
المصدر: Journal of the Medical Association of Thailand = Chotmaihet thangphaet. 93
مصطلحات موضوعية: Adult, Aged, 80 and over, DNA Topoisomerase IV, Male, Molecular Sequence Data, Drug Resistance, Microbial, Sequence Analysis, DNA, Middle Aged, Thailand, Polymerase Chain Reaction, Anti-Bacterial Agents, Hospitals, University, Streptococcus pneumoniae, DNA Gyrase, Disk Diffusion Antimicrobial Tests, Mutation, Humans, Female, Amino Acid Sequence, Serotyping, Aged, Fluoroquinolones
الوصف: The most frequent markers of fluoroquinolone resistance in S. pneumoniae are chromosomal mutations in the quinolone-resistance-determining regions of DNA gyrase and topoisomerase IV encoding for the gyrA, gyrB and parC, parE genes. In 2008, 6.5% of the Streptococcus pneumoniae isolates in a Bangkok university hospital were resistant to ofloxacin. Using PCR and DNA sequencing, we identified mutations in both the gyrA and parC genes of four ofloxacin- and ciprofloxacin-resistant S. pneumoniae isolates (minimum inhibitory concentrations32 microg/ml). Mutations were found in the gyrA gene at positions Ser81Phe, Glu85Gly, Glu85Lys and in the parC gene at position Ser79Tyr. Three isolates had mutations in both genes. Two of the isolates were serotype 6B and two were serotypes not contained in currently licensed pneumococcal vaccines. This is the first report of the mechanisms of fluoroquinolone resistance in S. pneumoniae in Thailand.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=pmid________::e6ba26edec97e0218d234fd29794bdacTest
https://pubmed.ncbi.nlm.nih.gov/21298832Test -
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المؤلفون: Somporn, Srifuengfung, Kulkunya, Chokephaibulkit
المصدر: Journal of the Medical Association of Thailand = Chotmaihet thangphaet. 93
مصطلحات موضوعية: Antigens, Bacterial, Humans, Polymerase Chain Reaction, Latex Fixation Tests, Cerebrospinal Fluid, Meningitis, Bacterial
الوصف: Rapid detection of bacterial pathogen causing meningitis is very important to guide antimicrobial therapy before the standard culture result is available. Other than gram stain, one of the most useful rapid methods is the detection of bacterial antigen in cerebrospinal fluid. This article reviewed the methods of bacterial antigen detection for diagnosis of meningitis as well as a microbiology aspect of this life-threatening disease.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=pmid________::f3bc78e1980543c997e840aa7f5aa8c2Test
https://pubmed.ncbi.nlm.nih.gov/21298833Test -
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المصدر: The Southeast Asian journal of tropical medicine and public health. 41(3)
مصطلحات موضوعية: Acinetobacter baumannii, Genetic Markers, Carbapenems, Disk Diffusion Antimicrobial Tests, Drug Resistance, Bacterial, Humans, Thailand, beta-Lactamases, Acinetobacter Infections, Plasmids
الوصف: Acinetobacter baumannii has emerged in health care settings as a pandrug-resistant pathogen. Carbapenems are ineffective for treatment of this pathogen. Here we explored the molecular epidemiology and mechanism of carbapenem resistance in clinical isolates of carbapenem-resistant A. baumannii (CRAB). Antibiotic susceptibility by disk diffusion test was performed using imipenem and meropenem disk on 200 different clinical CRAB isolates. All isolates were resistant and gave inhibition zones of both antibiotic disksor = 13 mm. Polymerase chain reaction (PCR) was carried out on 37 randomly selected isolates to amplify the common carbapenem hydrolyzing beta-lactamase genes (bla(OXA23)-like, bla(OXA-24/40)-like, bla(OXA-58), bla(IMP), and bla(VLM)). Clones were resolved by PCR-randomly amplified polymorphic DNA (PCR-RAPD) and plasmid profiling. PCR amplification and DNA sequencing revealed the existence of bla(OXA-23) downstream of the insertion element, ISAba1, in all 37 isolates tested. This segment was present in the carbapenem-resistant genomic resistant island AbaR4. These isolates were resolved into three RAPD types (Type I, 20 isolates; Type II, 16 isolates; and type III, 1 isolate) and 10 plasmid profiles. The CRAB isolates investigated here were oligoclonal and carbapenem resistance was conferred by the presence of bla(OXA-23). The presence of this beta-lactamase gene in many clonal isolates indicated its wide spread.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=pmid________::94ada784c2f3325d91f868e868972794Test
https://pubmed.ncbi.nlm.nih.gov/20578551Test -
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المؤلفون: Leilani, Paitoonpong, Anusang, Chitsomkasem, Suriwan, Chantrakooptungool, Suwattana, Kanjanahareutai, Chanwit, Tribuddharat, Somporn, Srifuengfung
المصدر: The Southeast Asian journal of tropical medicine and public health. 39(1)
مصطلحات موضوعية: Adult, Bartonella henselae, Base Sequence, Molecular Sequence Data, Angiomatosis, Bacillary, Humans, Female, HIV Infections, Thailand, Skin
الوصف: This is the first reported case of bacillary angiomatosis associated with Bartonella henselae in Thailand. The clinical, pathological, and microbiological findings are presented. The bacterium was isolated from a biopsy of skin lesions obtained on admission and identified by cellular morphology, characteristics of colonies on chocolate agar, extensive biochemical tests and 16S ribosomal DNA sequencing.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=pmid________::703f0561292889d36e5632edd9b669a4Test
https://pubmed.ncbi.nlm.nih.gov/18567451Test -
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المؤلفون: Somporn, Srifuengfung, Chanwit, Tribuddharat, Preecha, Champreeda, Justin, Daniels, Kulkanya, Chokephaibulkit, Nithita, Wongwan, Pitimon, Polwichai
المصدر: The Southeast Asian journal of tropical medicine and public health. 39(3)
مصطلحات موضوعية: Adult, Aged, 80 and over, Male, Adolescent, Penicillin Resistance, Respiratory System, Infant, Microbial Sensitivity Tests, Penicillins, Middle Aged, Pneumonia, Pneumococcal, Thailand, Community-Acquired Infections, Streptococcus pneumoniae, Child, Preschool, Drug Resistance, Multiple, Bacterial, Humans, Female, Child, Aged
الوصف: A total of 400 clinical Streptococcus pneumoniae strains from patients with respiratory diseases were collected from January 2002 to December 2005. In this study, an increased prevalence of penicillin-nonsusceptible S. pneumoniae (PNSP) from 63% in 2002-2003 to 69% in 2004-2005 was found. During 2004-2005, 56% were erythromycin-nonsusceptible S. pneumoniae (ENSP) and 54% were both PNSP and ENSP. The PNSP, ENSP and PNSP+ENSP groups showed similar trends, ie, sensitive to amoxicillin/clavulanate (range 97.2-98.5%), levofloxacin (range 90.7-92.4%), ceftriaxone (range 87.1-89.4%), and ofloxacin (range 64.8-66.1%). Lower levels of susceptibility were detected for azithromycin, clarithromycin, cefdinir, cefprozil, clindamycin, co-trimoxazole, chloramphenicol and tetracycline in penicillin and erythromycin-nonsusceptible strains. Of the macrolide-resistant S. pneumoniae, 55% of strains exhibited the M phenotype and 45% the constitutive MLS(B) phenotype. No pneumococci with the inducible MLS(B) phenotype were detected in Thailand.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=pmid________::c7b7dd5417a0a15ded5e0daf5b9d7661Test
https://pubmed.ncbi.nlm.nih.gov/18564685Test -
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المؤلفون: Pintip, Pongpech, Penphun, Naenna, Yupin, Taipobsakul, Chanwit, Tribuddharat, Somporn, Srifuengfung
المصدر: The Southeast Asian journal of tropical medicine and public health. 39(3)
مصطلحات موضوعية: Adult, Integrases, Drug Resistance, Multiple, Bacterial, Immunoblotting, Escherichia coli, Prevalence, Humans, Microbial Sensitivity Tests, Thailand, Polymerase Chain Reaction, Escherichia coli Infections, beta-Lactam Resistance, beta-Lactamases
الوصف: Among 120 Escherichia coli isolates from Thai patients, 37 and 9 isolates were extended-spectrum beta-lactamase (ESBL) and suspected ESBL producers respectively while 5 E. coli isolates from 120 Thai healthy adults were suspected ESBL producers. Integrase (intl1) gene was detected in 99% of the clinical and 87% of the non-clinical isolates. Among 37 ESBL producers, percent recovery of bla(TEM), bla(CTX-M), bla(SHV) and bla(VEB) was 78%, 78%, 8% and 8%, respectively. Twenty-five isolates of ESBL producers carried both bla(TEM) and bla(CTX-M), 2 isolates carried 3 genes (bla(TEM), blac(CTX-M), and bla(SHV)) and 3 showed no detectable bla gene. Among the 14 suspected ESBL producers, intl1 and bla(TEM) were detected in 13 isolates. ESBL producers from clinical samples were resistant to most of the tested antimicrobial agents compared to non-ESBL producers and isolates from healthy adults with about half of the latter susceptible to all tested antimicrobial agents. Only one clinical isolate was resistant to imipenem. Susceptibility to trimethoprim/sulfamethoxazole among the clinical isolates in ESBL producer group (27%) and non-producer group (33%) were comparable, whereas the percent susceptibility of the non-clinical isolates was about twice that of the clinical isolates.
الوصول الحر: https://explore.openaire.eu/search/publication?articleId=pmid________::b96c61bde730e8092013d66a0cffb326Test
https://pubmed.ncbi.nlm.nih.gov/18564681Test
