15 results
Search Results
Now showing 1 - 10 of 15
Item Metadata only Bacteriological quality in environmental water samples of one hospital at Chantaburi province(Mahidol University. Mahidol University Library and Knowledge Center, 1998) Tipawan Satidwiparawong; Unchalee Tansuphasiri; Angsana Boonthum; Gunya RoongratanaubonPublication Metadata only Association of sanitary conditions and bacteriological quality of tube ice in ice plants in metropolitan Bangkok, Thailand(2010-01-01) Kraichat Tantrakarnapa; Prasert Makkaew; Pisit Vatanasomboon; Tharadol Kengganpanich; Mahidol University. All 120 samples were analyzed for bacteriological quality by means of Standard Plate Count technique (Pour plate method) and Most Probable Number technique (MPN method). The results indicated that forty percent (8 Tube plants) failed and the remaining...This investigation aimed at studying the correlation between ice plant sanitary conditions and bacteriological quality of ice. The sanitary conditions in accordance with GMP regulations, the bacteriological quality of tube ice, and the processingItem Metadata only Identification of Biomarkers in Burkholderia Pseudomallei using Whole-Cell Maldi-TOF MS(Mahidol University. Mahidol University Library and Knowledge Center, 2023) Suthamat Niyompanich; Sumalee Tungpradabkul; Wilai Noonpakdee; Thaned Kangsamaksin; Jamorn SomanaBurkholderia pseudomallei is a pathogenic bacterium causing melioidosis, which is a serious human infectious disease with high mortality rates. Rapid identification and classification of B. pseudomallei from various sources could be advantageous for epidemiological tracking, medical prevention, and treatment of melioidosis. The whole-cell matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (whole- cell MALDI-TOF MS), a recently developed proteomics-based bacterial identification approach, could be employed for a rapid, robust, and accurate identification of B. pseudomallei. In this study, eleven isolates of B. pseudomallei collected from environmental and clinical sources were initially used for the whole-cell MALDI-TOF MS analyses; these included five environmental and six clinical isolates. The morphological appearance of most of these bacterial samples was purple, dry, and rough and was classified as morphotype I B. pseudomallei. By whole- cell MALDI-TOF MS approach, these bacteria were reliably identified as B. pseudomallei, based on five taxon- specific biomarkers and the identification scores obtained from BioTyper analysis. Cluster analysis of the environmental and clinical isolates revealed that six out of eleven isolates were correctly clustered according to their isolation sources. Upon further analysis using ClinProTools software, ten source-specific biomarkers were obtained according to their respective sources. Among these, six biomarkers (m/z 4056, 4214, 5814, 7545, 7895, and 8112 Da) were detected specific for the isolates of environmental source, and four (m/z 3658, 6322, 7035, and 7984 Da) were specific for clinical source. The clinical isolate-specific biomarkers were also observed in three laboratory-constructed rpoS, ppk, and bpsI mutants of clinical isolates that possessed single gene mutations in their respective gene locations, confirming their source of origin. Cluster analysis indicated that the wild-type PP844 reference strain, rpoS, ppk, and bpsI strains were separately dispersed. Thus the whole-cell MALDI-TOF MS method could distinguish B. pseudomallei isolates originated from either environmental or clinical sources as well as mutants bearing genetic changes. Moreover, subsequent ClinProTools analysis could identify the potential biomarkers specific to each of the three mutants. In this respect, a total of twelve candidate biomarkers were discovered, specific for each of the three mutant strains. These biomarkers included m/z 2721 and 2748 Da which were specific for the rpoS mutant, m/z 3150, 3378, and 7994 Da for ppk, and seven mass peaks at m/z 3420, 3520, 3587, 3688, 4623, 4708, and 5450 Da for bpsI. The present study is thus the first to establish and identify the source-specific and mutant-specific biomarkers for the identification and classification of B. pseudomallei based on whole-cell MALDI-TOF MS approach. These findings have also broadened the applicability of the whole-cell MALDI-TOF as a laboratory-based tool to rapidly, accurately, and reproducibly identify extensive libraries of the genetically modified bacteria.Item Metadata only Pseudomonas pseudomallei : immunological studies with special application for the diagnosis of melioidosis(Mahidol University. Mahidol University Library and Knowledge Center, 2024) Huttaya Wuttipongwaragid; Stitaya Sirisinha; Surasakdi Wongratanacheewin; Sansanee Chaiyarojdiagnosis of this bacterial infection is based on laboratory findings including bacteriology and serology. Currently, the identification of a causative agent from bacteriological culture is the only available definitive confirmatory diagnosis but it is time...), complement fixation(CF), indirect fluorescent (IFA), indirect ELISA and most recently gold blotting. These techniques are of limited value particularly because of the high background antibody titer among healthy individuals in the endemic area of infectionPublication Metadata only A three year descriptive study of early onset neonatal sepsis in a refugee population on the thailand myanmar border(2013-12-21) Claudia Turner; Paul Turner; Gabie Hoogenboom; Naw Aye Mya Thein; Rose McGready; Kawalee Phakaudom; Aruni De Zoysa; Androulla Efstratiou; Paul T. Heath; François Nosten; Shoklo Malaria Research Unit; Mahidol University; University of Oxford; Health Protection Agency; St George's University of LondonResearch Unit clinic in Maela camp for displaced persons on the Thailand-Myanmar border. Episodes of EONS were identified using a clinical case definition. Conventional and molecular microbiological techniques were employed in order to determine underlying... in the cerebrospinal fluid specimen in this infant, and in an additional two infants, by PCR. Therefore, the incidence of bacteriologically proven EONS was 0.7 per 1000 live births (95% CI 0.1 - 2.1). No infants enrolled in study died as a direct result of EONSPublication Metadata only Microbiological quality of drinking water and using water of a Chao Phya River community, Bangkok.(1994-12-01) P. Luksamijarulkul; V. Pumsuwan; S. Pungchitton; Mahidol Universityroutine testing of the bacteriological quality of drinking water is designed to detect the presence of coliform bacteria and virological assessment is to detect the presence of enteric viruses, especially hepatitis A virus (HAV). Therefore, this study... samples of used water in containers were collected with sterile technique for determining HAV antigen by ELISA and coliform contamination by the Most Probable Number Technique (MPN). The results revealed that HAV and coliform contamination ratesPublication Metadata only Evaluation of the appropriate diagnostic tools for intra-mammary infection in lactating dairy goats(2009-04-01) Jitkamol Thanasak; Nareerat Sangkachai; Kulanan Imsawang; Surasak Jittakhot; Mahidol UniversitySixty milk samples of healthy, lactating dairy goats were collected by an aseptic, hand milking technique. All samples were analyzed using milk quality tests: bacterial isolation (Bac), total plate count (TPC), dye reduction test (DRT) and clot... samples for intra-mammary infection (IMI) and 26 samples for non-IMI, the results showed that Bac and TPC were the most reliable techniques for the determination of IMI with strong correlations. For an instantaneous milk quality test, CMT reactionPublication Open Access Light scattering sensor for direct identification of colonies of Escherichia coli serogroups O26, O45, O103, O111, O121, O145 and O157.(2014-08-19) Tang, Yanjie; Kim, Huisung; Singh, Atul K.; Amornrat Aroonnual; อมรรัตน์ อรุณนวล; Bae, Euiwon; Rajwa, Bartek; Fratamico, Pina M.; Bhunia, Arun K.; Bhunia, Arun K.; Mahidol University. Faculty of Tropical Medicine. Department of Tropical Nutrition & Food Science.BACKGROUND: Shiga-toxin producing Escherichia coli (STEC) have emerged as important foodborne pathogens, among which seven serogroups (O26, O45, O103, O111, O121, O145, O157) are most frequently implicated in human infection. The aim was to determine if a light scattering sensor can be used to rapidly identify the colonies of STEC serogroups on selective agar plates. METHODOLOGY/PRINCIPAL FINDINGS: Initially, a total of 37 STEC strains representing seven serovars were grown on four different selective agar media, including sorbitol MacConkey (SMAC), Rainbow Agar O157, BBL CHROMagarO157, and R&F E. coli O157:H7, as well as nonselective Brain Heart Infusion agar. The colonies were scanned by an automated light scattering sensor, known as BARDOT (BActerial Rapid Detection using Optical scattering Technology), to acquire scatter patterns of STEC serogroups, and the scatter patterns were analyzed using an image classifier. Among all of the selective media tested, both SMAC and Rainbow provided the best differentiation results allowing multi-class classification of all serovars with an average accuracy of more than 90% after 10-12 h of growth, even though the colony appearance was indistinguishable at that early stage of growth. SMAC was chosen for exhaustive scatter image library development, and 36 additional strains of O157:H7 and 11 non-O157 serovars were examined, with each serogroup producing unique differential scatter patterns. Colony scatter images were also tested with samples derived from pure and mixed cultures, as well as experimentally inoculated food samples. BARDOT accurately detected O157 and O26 serovars from a mixed culture and also from inoculated lettuce and ground beef (10-h broth enrichment +12-h on-plate incubation) in the presence of natural background microbiota in less than 24 h. CONCLUSIONS: BARDOT could potentially be used as a screening tool during isolation of the most important STEC serovars on selective agar plates from food samples in less than 24 h.Publication Open Access Bacterial Contamination in Raw Shucked Oysters in Shucking Houses and Retail Shops in Chon Buri Province,Thailand(2011) Chaweewun Intarakul; Suwanna Panutrakul; Sirichom Thungkao; ฉวีวรรณ อินทรกุล; สุวรรณา ภาณุตระกูล; ศิริโฉม ทุ่มเก้า; Burapha University. Faculty of Public Health; Burapha University. Faculty of Science. Department of Aquatic Science; Burapha University. Faculty of Science. Department of Microbiology; Mahidol University. Faculty of Science. Toxicology and Management of ChemicalsOysters may be cross-contaminated with bacteria from an unsanitary shucking process and sale. Hence the aims of this study were to compare bacterial contamination in samples of shucked oysters from aseptic shucking, in shucking houses, and in retail shops in Chon Buri Province, and to investigate bacterial contamination in samples from surface areas of equipment, the fresh water used in the shucking process, and oysters processed for sale. Analysis of variance was performed after a logarithmic transformation of bacterial counts was conducted. The results revealed that counts of total bacteria, Staphylococcus aureus, and fecal coliforms in aseptically shucked oysters, were significantly lower than those same measurements in freshly-shucked oysters (p < 0.01, = 0.01, < 0.01, respectively) and in packed-shucked oysters (p < 0.01, < 0.01, < 0.01, respectively). About 90-100% of the shucking equipment was contaminated with total bacterial counts higher than acceptable limits, both before and during use. Fresh water exceeded the standards for total bacteria and coliforms in all samples, both before and after washing. The 40% of unwashed and 50% of washed shucked oysters exceeded the standard for total bacteria. The results indicated that bacterial contamination in these samples may be a consequence of unsanitary cleaning, storage, and handling of equipment and fresh water, including improper temperature controls during oyster processing and sale.Publication Open Access Application of High-Frequency Oscillation during Bronchoscopy in Smear-Negative Pulmonary Tuberculosis(2017) Viratch Tangsujaritvijit; Somcharoen Thienchairoj; Detajin Junhasavasdikul; Thotsaporn Morasert; Dararat Eksombatchai; วิรัช ตั้งสุจริตวิจิตร; สมเจริญ เทียนชัยโรจน์; เดชอาจิณ ชุณหสวัสดิกุล; ทศพร โมระเสริฐ; ดารารัตน์ เอกสมบัติชัย; Mahidol University. Faculty of Medicine Ramathibodi Hospital. Department of Medicine; Surat Thani Hospital. Department of Medicine; Maharat Nakhon Ratchasima Hospital. Department of MedicineBackground: The diagnostic yield of bronchoalveolar lavage (BAL) for diagnosis of pulmonary tuberculosis (PTB) is low. The vibrator device is useful for sputum induction. Objective: This trial was aimed to assess the value of high-frequency oscillation (HFO) during fiberoptic bronchoscopy (FOB) for diagnosis of patients with suspected PTB. Methods: Suspected PTB patients with two consecutive negative sputum acid-fast bacilli (AFB) smears were recruited. Patients were chosen to use the HFO device by randomization, while the other patients underwent standard BAL. The BAL fluid and post-bronchoscopic sputum were processed for AFB smear and culture, and polymerase chain reaction for TB (PCR-TB). Results: Eighty patients participating in this study, PTB was definitely diagnosed in 32 patients. The diagnostic yield of HFO with BAL culture was 27.8%, and non-HFO 21.1% (P = 0.71). The diagnostic yield of HFO with post-bronchoscopic sputum culture was 22.2%, and non-HFO 21.1% (P = 1.00). The diagnostic yield of PCR-TB with HFO was 33.3%, and non-HFO 21.1% (P = 0.47). Conclusions: Addition of HFO during FOB did not result in significant differences in the diagnostic yield of PTB detection in smear-negative PTB patients. However, there was a trend of increasing sensitivity of BAL PCR-TB in patients receiving HFO.