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Item Open Access Detection and identification of Escherichia coli and Staphylococcus aureus by Raman spectroscopy(2019) Sirichayaporn Huayhongthong; Piyatip Khuntayaporn; Pagakrong Wanapaisan; Krit Thirapanmethee; Chutima Phechkrajang; Nattawut Chareonthai; Mullika Traidej Chomnawang; ปิยทิพย์ ขันตยาภรณ์; ผกากรอง วนไพศาล; กฤษณ์ ถิรพันธุ์เมธี; ชุติมา เพชรกระจ่าง; ณัฐวุฒิ เจริญไทย; มัลลิกา (ไตรเดช) ชมนาวัง; Mahidol University. Faculty of Pharmacy. Department of Microbiology; Mahidol University. Faculty of Pharmacy. Department of Pharmaceutical Chemistry; Mahidol University. Faculty of Pharmacy. Department of Manufacturing Pharmacybetween Raman spectra of Gram-negative and Gram-positive bacteria. The resultant plots showed that the bacterial spectra displayed degree of discrimination and accuracy identification in calculating accounted for 73.39% of total variance of the first... the microorganism. In this study, Raman spectroscopy was applied to detect and identify the food-borne pathogens, including Gram-positive and Gram-negative bacteria. The multivariate statistical analysis of principal component analysis (PCA) was usedPublication Open Access Epidemiology of bacteremia caused by uncommon non-fermentative gram-negative bacteria(2013) Pinyo Rattanaumpawan; Prapassorn Ussavasodhi; Pattarachai Kiratisin; Nalinee Aswapokee; Mahidol University. Faculty of Medicine Siriraj Hospital. Division of Infectious Diseases and Tropical MedicineBackground: Prevalence of bacteremia caused by non-fermentative gram-negative bacteria (NFGNB) has been increasing over the past decade. Although many studies have already investigated epidemiology of NFGNB bacteremia, most focused only on commonPublication Open Access Comparison of two multilocus sequence based genotyping schemes for Leptospira species.(2011-11) Ahmed, Ahmed; Janjira Thaipadungpanit; จันทร์จิรา ไทยผดุงพานิช; Siriphan Boonsilp; ศิริพรรณ บุญศิลป์; Vanaporn Wuthiekanun; วรรณพร วุฒิเอกอนันต์; Nalam, Kishore; Spratt, Brian G.; Aanensen, David M.; Smythe, Lee D.; Ahmed, Niyaz; Feil, Edward J.; Hartskeer, Rudy A.; Peacock, Sharon J.; Ahmed, Ahmed; Mahidol University. Faculty of Tropical Medicine. Department of Microbiology and Immunology.; Mahidol University. Faculty of Tropical Medicine. Mahidol-Oxford Tropical Medicine Research Unit.; Mahidol Univeristy. Faculty of Medicine Siriraj Hospital. Medical Proteomics Unit, Office for Research and Development.BACKGROUND: Several sequence based genotyping schemes have been developed for Leptospira spp. The objective of this study was to genotype a collection of clinical and reference isolates using the two most commonly used schemes and compare and contrast the results. METHODS AND FINDINGS: A total of 48 isolates consisting of L. interrogans (n = 40) and L. kirschneri (n = 8) were typed by the 7 locus MLST scheme described by Thaipadungpanit et al., and the 6 locus genotyping scheme described by Ahmed et al., (termed 7L and 6L, respectively). Two L. interrogans isolates were not typed using 6L because of a deletion of three nucleotides in lipL32. The remaining 46 isolates were resolved into 21 sequence types (STs) by 7L, and 30 genotypes by 6L. Overall nucleotide diversity (based on concatenated sequence) was 3.6% and 2.3% for 7L and 6L, respectively. The D value (discriminatory ability) of 7L and 6L were comparable, i.e. 92.0 (95% CI 87.5-96.5) vs. 93.5 (95% CI 88.6-98.4). The dN/dS ratios calculated for each locus indicated that none were under positive selection. Neighbor joining trees were reconstructed based on the concatenated sequences for each scheme. Both trees showed two distinct groups corresponding to L. interrogans and L. kirschneri, and both identified two clones containing 10 and 7 clinical isolates, respectively. There were six instances in which 6L split single STs as defined by 7L into closely related clusters. We noted two discrepancies between the trees in which the genetic relatedness between two pairs of strains were more closely related by 7L than by 6L. CONCLUSIONS: This genetic analysis indicates that the two schemes are comparable. We discuss their practical advantages and disadvantages.Publication Open Access The Effects of Heartwood Extracts from Biancaea sappan L. against Coagulase-Negative Staphylococci (CoNS) and Staphylococcus aureus Isolated from Subclinical Mastitis in Dairy Goats(2021) Panitnun Leelakhachonchit; Raweephun Phongprai; Wannapa Jiennumwong; Chowalit Nakthong; Norasuthi Bangphoomi; Arpron Leesombun; Orathai Thongjuy; Sookruetai Boonmasawai; Mahidol University. Faculty of Veterinary Science; Mahidol University. Faculty of Veterinary Science. The Center for Veterinary Diagnosis; Mahidol University. Faculty of Veterinary Science. Department of Clinical Sciences and Public Health; Mahidol University. Faculty of Veterinary Science. Department of Pre-clinic and Applied Animal Science) contents were not observed. The bacterial identifications from milk samples revealed that the most commonly isolated bacteria were coagulase-negative staphylococci (CoNS) (n=41, 78.9%) and Staphylococcus aureus (n=7, 13.5%). The ethanolic extracts from B... the antimicrobial intra-mammary infusion, and it may cause antimicrobial resistance problems. Thus, this study aimed to determine the change of milk composition and the antibacterial activity of ethanolic extracts from Biancaea sappan L. heartwood against bacteriaPublication Open Access Proteome analyses of cellular proteins in methicillin-resistant staphylococcus aureus treated with rhodomyrtone, a novel antibiotic Candidate(2011) Wipawadee Sianglum; Potjanee Srimanote; Wijit Wonglumsom; Kanokwan Kittiniyom; Supayang P.Voravuthikunchai.25–62.5 mg/ml, and the minimal bactericidal concentration (MBC) was 250 mg/ml. Rhodomyrtone, an acylphloroglucinol derivative, was 62.5–125 times more potent at inhibiting the bacteria than the ethanolic extract, the MIC and MBC values were 0.5 mg/mlPublication Open Access Lupinifolin, a bioactive flavanone from Myriopteron extensum (Wight) K. Schum. stem(2004-12) Noppamas Soonthornchareonnon; Lersak Ubonopas; Songsri Kaewsuwan; Mansong Wuttiudomlert; Mahidol University. Faculty of Pharmacy. Department of Pharmacognosy; Mahidol University. Faculty of Pharmacy. Department of MicrobiologyLupinifolin was isolated from the crude hexane extract of Myriopteron extensum stem. Structural identification was carried on by spectroscopic methods and the comparison of its mp,[α]27 D, 1H and 13C NMR spectroscopic data with published values.... Both of them showed moderate active to Gram-positive bacteria and no activity against Gram-negative bacteria. Lupinifolin and the ethanolic extract showed inactive in the DPPH radical scavenging, antiplasmodial and anti-inflammatory assayPublication Open Access Functional characterization of two members of histidine phosphatase superfamily in Mycobacterium tuberculosis(2013) Olabisi Oluwabukola Coker; Saradee Warit; Kamolchanok Rukseree; Pijug Summpunn; Therdsak Prammananan; Prasit Palittapongarnpim; Mahidol University. Faculty of Science. Department of MicrobiologyBackground: Functional characterization of genes in important pathogenic bacteria such as Mycobacterium tuberculosis is imperative. Rv2135c, which was originally annotated as conserved hypothetical, has been found to be associated with membrane... phosphoglycerate mutase of M. tuberculosis. Additional characterization showed that Rv2135c exists as a tetramer while Rv0489 as a dimer in solution. Conclusion: Most of the proteins orthologous to Rv2135c in other bacteria are annotated as phosphoglyceratePublication 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 Clustering of antimicrobial resistance outbreaks across bacterial species in the intensive care unit.(2013-07) Vlek, Anne L. M.; Cooper, Ben S.; Kypraios, Theodore; Cox, Andy; Edgeworth, Jonathan D.; Auguet, Olga Tosas; Vlek, Anne L. M.; Mahidol University. Faculty of Tropical Medicine. Mahidol-Oxford Tropical Medicine Research Unit.BACKGROUND: There are frequent reports of intensive care unit (ICU) outbreaks due to transmission of particular antibiotic-resistant bacteria. Less is known about the burden of outbreaks of resistance due to horizontal transfer of mobile genetic... of bacteria commonly identified in the ICU. There was evidence for frequent temporal clustering of resistance outbreaks consistent with interspecies transmission of resistance elements. Wider application of outbreak detection software combined with targetedPublication Open Access Aedesin: structure and antimicrobial activity against multidrug resistant bacterial strains.(2014-08-27) Godreuil, Sylvain; Leban, Nadia; Padilla, Andre´; Hamel, Rodolphe; Natthanej Luplertlop; นัฏฐเนศวร์ ลับเลิศลบ; Chauffour, Aure´ lie; Vittecoq, Marion; Hoh, Franc¸ois; Thomas, Fre´de´ ric; Sougakoff, Wladimir; Lionne, Corinne; Yssel, Hans; Misse, Dorothe´e; Misse, Dorothe´e; Mahidol University. Faculty of Tropical Medicine. Department of Microbiology and Immunology.Multidrug resistance, which is acquired by both Gram-positive and Gram-negative bacteria, causes infections that are associated with significant morbidity and mortality in many clinical settings around the world. Because of the rapidly increasing... of clinically relevant resistance mechanisms known today, Aedesin might be an interesting candidate for the development of alternative treatment for infections caused by these types of bacteria.