Papers by Suporn Foongladda
PubMed, Sep 1, 2013
Objective: To develop a high-resolution melting curve analysis (HRM) assay for detection of PZA r... more Objective: To develop a high-resolution melting curve analysis (HRM) assay for detection of PZA resistance. Material and method: Thirty samples of PZA-susceptible M. tuberculosis and eight isolates of PZA-resistant M. tuberculosis were included in the experiment. Five sets of primers were designed to cover the pncA gene and its upstream nucleotides. The pncA gene fragments were amplified by the PCR method. Determination of pncA mutation in the sample by comparing their melting behavior of the PCR products with the M. tuberculosis wild type by using Gene scanning software of the LightCycler 480 instrument. Results: Mutations were clearly detected in all PZA resistant samples by the HRM, whereas all PZA susceptible samples showed no mutation in the pncA gene. Results were concordant with the drug susceptibility testing by using BACTEC MGIT 960 PZA kit and mutation detection by the DNA sequencing method. Conclusion: This HRM method offers a rapid and reliable screen for PZA resistant M. tuberculosis.
Microbiology resource announcements, Oct 20, 2022
Users may download and print one copy of any publication from the public portal for the purpose... more Users may download and print one copy of any publication from the public portal for the purpose of private study or research. You may not further distribute the material or use it for any profit-making activity or commercial gain You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.
Microbiology resource announcements, Sep 15, 2022
Swine feed-additive probiotics products play a major role in swine performance and welfare by pro... more Swine feed-additive probiotics products play a major role in swine performance and welfare by promoting gut health. Here, we present two types of data, including a full-length 16S rRNA amplicon sequence data and a long-read metagenomic sequence data obtained from the same commercial probiotic product.
PubMed, Mar 1, 2014
Objective: To determine the characteristics of pulmonary tuberculosis (TB) patients harbored orga... more Objective: To determine the characteristics of pulmonary tuberculosis (TB) patients harbored organisms with isoniazid mono-resistant drug susceptibility pattern. Material and method: A retrospective review of medical records for all culture-proven adult pulmonary TB patients in Siriraj Hospital between July 2009 and July 2011 was conducted. Demographic data, clinical presentations, and radiological characteristics were recorded and compared between isoniazid mono-resistant and other-resistant groups. Treatment regimens with outcome determination of patients infected with isoniazid mono-resistant strains were also verified. Results: Among 489 patients during the present study period, 28 were infected with isoniazid mono-resistant strain (5.7%). The mean age was 53 +/- 18 years, and 8% of them had a history of previous treatment in the past. When compared with those infected with any other form of resistant strains, isoniazid mono-resistant pulmonary TB patients tended to have less radiographic cavitary lesion (8.3% vs. 26.7%, p = 0.006) but no significant difference was seen in term of demographic data and clinical presentations. All of them who had completed the treatment were cured. No difference in cure rate and relapse rate among patients treated with quinolone or non-quinolone containing regimens. Conclusion: Isoniazid mono-resistance shares common clinical features with other resistances pulmonary TB, except for less cavitary lesion from initial chest radiograph. Appropriate drug susceptibility testing with prompt regimen adjustment can lead to a favorable treatment outcome.
PubMed, Feb 1, 2012
Objective: To determine the optimum number of sputum specimens for smear and culture in the diagn... more Objective: To determine the optimum number of sputum specimens for smear and culture in the diagnosis of pulmonary tuberculosis. Material and method: A retrospective study was conducted in culture-positive pulmonary tuberculosis patients at Siriraj Hospital during April 2009 to October 2010. Number of sputum specimens and microbiological results were retrieved from the microbiologic laboratory. Positive yield and incremental yield of each sputum specimen were calculated. Results: There were 401 patients during the study period, 153 (38.2%) had positive smear for acid-fast bacilli. Overall diagnostic yields of solid culture media and liquid culture media, were 72.1% and 95.3% respectively. Incremental of overall diagnostic yield from 1 to 2 and 2 to 3 sputum specimens were 8% and 6% respectively. Conclusion: In place where a routinely combined smear and culture for every sputum sample submitted to the microbiologic laboratory, two specimens are sufficient for the diagnosis in nearly all pulmonary tuberculosis patients.
Diagnostic Microbiology and Infectious Disease, Nov 1, 2015
Pyrazinamide (PZA) plays a critical role in shortening tuberculosis treatment duration and in tre... more Pyrazinamide (PZA) plays a critical role in shortening tuberculosis treatment duration and in treating MDR-TB. The standard phenotypic MGIT PZA susceptibility testing method is imperfect because it is slow and has potential for false resistance. In this study we evaluated two different phenotypic based methods, qPCR phage assay and MTT assay, as well as genotypic sequencing. The assay was evaluated on 71 clinical M. tuberculosis isolates (37 MGIT PZA susceptible, 34 MGIT PZA resistant) and compared to the MGIT result. Of these methods the qPCR phage assay yielded an accuracy of 89% versus standard MGIT while MTT yielded 83%. The genotypic sequencing method yielded 90% accuracy. We conclude that any of these faster PZA susceptibility methods perform reasonably well against a MGIT PZA susceptibility standard.
PubMed, Sep 1, 2007
Two HIV-1 strains, CRF01_AE and subtype B', were reported in Thailand during the early years of t... more Two HIV-1 strains, CRF01_AE and subtype B', were reported in Thailand during the early years of the epidemic. Recently, an intersubtype recombination of HIV-1 strain was found in Thailand. Eight-hundred and twenty-eight samples collected during years 1995-2004 from high-risk groups in Bangkok, northern, northeastern, and southern region of Thailand were studied. HIV-1 env nucleotide sequences were used for phylogenetic analysis of the circulating HIV-1 strain. By single HIV-1 region (env) genotyping, CRFO1_AE was found in 97.3% and HIV-1 subtype B was found in 2.7%. A predominance of CRF01_AE was found in all geographic regions. Parallel analysis of the HIV-1 gag and env genes demonstrated that 2.1% and 4.0% of recombinant HIV-1 strains were found using p17 and p24 region sequences, respectively. The recombinant gag gene was also found in one southern isolate. Phylogenetic analysis of HIV-1 isolated from 20 provinces in 2002 suggested the northern and northeastern isolates were more related than the southern isolates which had the lowest genetic diversity of 0.13. The GPGQ V3 loop tip was also present in isolates from all regions. The molecular epidemiological data from this study may be useful for surveillance design as well as targeting prevention efforts. It also provides information regarding new antigenic regions of circulating strains responsible for the HIV-1 epidemic in Thailand.
Diagnostic Microbiology and Infectious Disease, Mar 1, 2005
The increasing incidence of tuberculosis and other mycobacterial infections due to AIDS epidemic ... more The increasing incidence of tuberculosis and other mycobacterial infections due to AIDS epidemic resulted in the need of rapid and accurate identification of isolated mycobacteria. The correct identification result leads to the selection of an appropriate therapeutic regimen. Polymerase chain reaction and restriction enzyme analysis (PCR-REA) has been developed since 1992 and used as the rapid method for identifying mycobacteria. Several genes or sequences have been used as an amplified target for PCR-REA. The present study aims to evaluate the potential use of PCR-REA of gene-encoding heat shock protein 65 kDa (hsp65) and beta-subunit RNA polymerase (rpoB) for the identification of mycobacteria compared with conventional biochemical identification. Two hundreds clinical isolates, consisting of 50 isolates of Mycobacterium tuberculosis and 150 isolates of nontuberculous mycobacteria (NTM), were submitted for identification using PCR-REA and biochemical method. The results demonstrated that PCR-REA identified 188 isolates of both M. tuberculosis and NTM concordantly with biochemical identification. Discordant identification results obtained from 12 isolates, comprised of 8 M. scrofulaceum, 1 M. avium complex, 1 M. malmoense, 1 M. terrae complex, and 1 M. chelonae/abscessus. Overall, the concordant percentage of results obtained from PCR-REA compared with biochemical method was 100%, 98.8%, and 83.3% for M. tuberculosis complex, rapidly growing, and slowly growing mycobacteria, respectively, and the results of hsp65 PCR-REA was in agreement with those obtained from rpoB PCR-REA. From this study, PCR-REA appears to be a simple, rapid, and reliable method for identifying mycobacteria in a routine microbiology laboratory.
PubMed, Dec 1, 2002
The MTT method for rifampicin and isoniazid susceptibility testing of Mycobacterium tuberculosis ... more The MTT method for rifampicin and isoniazid susceptibility testing of Mycobacterium tuberculosis was developed by using bacterial suspension prepared from colonies on solid media. The MTT tube assay in 1 ml Middlebrook 7H9 broth was completed within 4 days for rifampicin (RMP) and within 7 days for isoniazid (INH). When MTT assay results with 279 M. tuberculosis clinical isolates were compared with those of the conventional proportion method on Löwenstein-Jensen medium, high specificity and sensitivity values of 100% and 94.1%, respectively, for RMP susceptibility testing, and 99.5% and 89.2%, respectively, for INH susceptibility testing were obtained. The accuracy of the MTT method for RMP and INH was > 0.97 concordance with the proportion method. The MTT method is simple, inexpensive and rapid. The high level of agreement with the conventional proportion method suggests a potential to rapidly detect drug-resistant M. tuberculosis in developing countries, as only basic microbiological equipment is need.
Frontiers in Microbiology, Jun 17, 2020
Antimicrobial use in agricultural animals is known to be associated with increases in antimicrobi... more Antimicrobial use in agricultural animals is known to be associated with increases in antimicrobial resistance. Most prior studies have utilized culture and susceptibility testing of select organisms to document these phenomena. In this study we aimed to detect 66 antimicrobial resistance (AMR) genes for 10 antimicrobial agent classes directly in swine fecal samples using our previously developed antimicrobial resistance TaqMan array card (AMR-TAC) across three different swine farm management systems. This included 38 extensive antimicrobial use (both in treatment and feed), 30 limited antimicrobial use (treatment only), and 30 no antimicrobial use farms. The number of resistance genes detected in extensive antimicrobial use farms was higher than in limited and no antimicrobial use farms (28.2 genes ± 4.2 vs. 24.0 genes ± 4.1 and 22.8 genes ± 3.6, respectively, p < 0.05). A principal component analysis and hierarchical clustering of the AMR gene data showed the extensive use farm samples were disparate from the limited and no antimicrobial use farms. The prevalence of resistance genes in extensive use farms was significantly higher than the other farm categories for 18 resistance genes including bla SHV , bla CTX−M1 group, bla CTX−M9 group, bla VEB , bla CMY2−LAT, aac(6)-lb-cr, qnrB1, gyrA83L-E. coli, armA, rmtB, aac(3)-IIa, mphA, 23S rRNA 2075G-Campylobacter spp., mcr-1, catA1, floR, dfrA5-14, and dfrA17. These genotypic findings were supported by phenotypic susceptibility results on fecal E. coli isolates. To examine the timing of AMR gene abundance in swine farms, we also performed a longitudinal study in pigs. The results showed that AMR prevalence occurred both early, presumably from mothers, as well as after weaning, presumably from the environment. In summary, detection of AMR genes directly in fecal samples can be used to qualitatively and quantitatively monitor AMR in swine farms.
International Journal of Tuberculosis and Lung Disease, Aug 1, 2016
* pncA mutations were detected using high-resolution melt analysis. MIC ¼ minimum inhibitory conc... more * pncA mutations were detected using high-resolution melt analysis. MIC ¼ minimum inhibitory concentration; LJ ¼ Löwenstein-Jensen proportion method; MGIT ¼ Mycobacterium Growth Indicator Tube; INH ¼ isoniazid; RMP ¼ rifampin; EMB ¼ ethambutol; SM ¼ streptomycin; AMK ¼ amikacin; KM ¼ kanamycin; OFX ¼ ofloxacin; MFX ¼ moxifloxacin; NA ¼ not applicable (no endorsed critical concentration); ETH ¼ ethionamide; PAS ¼ para-aminosalicylic acid; PZA ¼ pyrazinamide. * As not all results are available for all methodologies or all drugs, not all comparisons sum to n ¼ 212. DST ¼ drug susceptibility testing; CI ¼ confidence interval; INH ¼ isoniazid; NA ¼ not applicable; RMP ¼ rifampin; EMB ¼ ethambutol; SM ¼ streptomycin; AMK ¼ amikacin; KM ¼ kanamycin; OFX ¼ ofloxacin; MFX ¼ moxifloxacin; PZA ¼ pyrazinamide.
Vector-borne and Zoonotic Diseases, Oct 1, 2011
and Anaplasma as agents of rickettsioses, ehrlichioses and anaplasmosis, respectively, are transm... more and Anaplasma as agents of rickettsioses, ehrlichioses and anaplasmosis, respectively, are transmitted by ticks. As well, fleas can transmit Rickettsia and Bartonella. The presence of Rickettsia, Ehrlichia, Anaplasma and Bartonella in ticks and fleas on dogs and cats from various sites in Bangkok during June 2006 to Dec 2007 were investigated by PCR and sequencing of the gltA and 17 kDa genes for Rickettsia, the 16S rRNA gene for Anaplasmataceae, and the pap31 and its genes for Bartonella. A total of 152 flea-clones (5-10 fleas/dog or cat) from 98 dogs and 54 cats were identified as 78 Ctenocephalides canis and 74 C. felis. All 304 tick-clones (5-10 ticks/dog) from 304 dogs were Rhipicephalus specie. Rickettsia felis-like DNA was detected in 66 of 98 (67.4%) fleas-clones from dogs, including C. canis (49/65, 75.4%) and C. felis (17/33, 51.5%). All sequences were identical to Rickettsia sp. RF2125 which had a 97.9% similarity to Rickettsia felis. The number of rickettsial DNA detected in fleas from dogs with fever (17 of 26, 65.4%) was higher than that in fleas from dogs without fever (30 of 54, 55.6%). All flea-clones collected from cats and tick clones were negative for Rickettsia DNA detection. Bartonella DNA (8 B. henselae and 2 B. clarridgeiae) were detected in 10 of 54 flea-clones (18.5%) from cats. Six C. felis and 2 C. canis clones contained B. henselae. In addition, 2 C. felis clones contained B. clarridgeiae. All flea-clones collected from dogs were negative for Bartonella DNA detection. Anaplasmataceae DNA were detected in 19 tick-clones (6.3%):10 Ehrlichia canis (3.3%), 7 Anaplasma platys (2.3 %) and 2 Wolbachia pipientis (0.66%). In conclusion, this is the first finding that dog fleas carry Rickettsia felis-like organism. Thus, further studies of its pathogenicity and biology should be investigated. In addition, this is also the first finding of Bartonella in C. canis fleas and E. canis, A. platys, W. pipientis in dog ticks.
PLOS ONE, Feb 27, 2013
Drug resistance in Mycobacterium tuberculosis presents an enormous public health threat. It is ty... more Drug resistance in Mycobacterium tuberculosis presents an enormous public health threat. It is typically defined as .1% of drug resistant colonies using the agar proportion method. Detecting small numbers of drug resistant Tb in a population, also known as heteroresistance, is challenging with current methodologies. Here we have utilized digital PCR to detect heteroresistance within M. tuberculosis populations with excellent accuracy versus the agar proportion method. We designed dual TaqMan-MGB probes to detect wild-type and mutant sequences of katG (315), rpoB (531), gyrA (94,95) and rrs (1401), genes that associate with resistance to isoniazid, rifampin, fluoroquinolone, and aminoglycoside respectively. We generated heteroresistant mixtures of susceptible and extensively drug resistant Tb, followed by DNA extraction and digital PCR. Digital PCR yielded a close approximation to agar proportion's percentages of resistant colonies, and yielded 100% concordance with agar proportion's susceptible/resistant results. Indeed, the digital PCR method was able to identify mutant sequence in mixtures containing as little as 1000:1 susceptible:resistant Tb. By contrast, real-time PCR or PCR followed by Sanger sequencing were less sensitive and had little resolution to detect heteroresistance, requiring fully 1:1 or 10:1 susceptible:resistant ratios in order to detect resistance. Our assay can also work in sputum so long as sufficient quantities of Tb are present (.1000 cfu/ml). This work demonstrates the utility of digital PCR to detect and quantify heteroresistance in drug resistant Tb, which may be useful to inform treatment decisions faster than agar proportion.
International Journal of Infectious Diseases, Mar 1, 2010
Emerging Infectious Diseases, Sep 1, 2019
International Journal of Tuberculosis and Lung Disease, Oct 1, 2013
Few data on drug-resistant (DR) tuberculosis (TB) in children are available in Thailand. To evalu... more Few data on drug-resistant (DR) tuberculosis (TB) in children are available in Thailand. To evaluate the rate, clinical features and risk of DR-TB in children. Observational prospective study conducted in children diagnosed with TB at a tertiary care centre in Bangkok. Of 230 children diagnosed with TB, the median age was 6.5 years; 63% had identified adult source cases, and only 7% had received prior isoniazid treatment for latent tuberculous infection. Of the 195 (85%) specimens submitted, 57 (25%) were positive using culture or polymerase chain reaction. Of the 53 positive specimens available for drug susceptibility testing (DST), 18 (34%) had any resistance, 13 (24.5%) were mono-resistant, 2 (3.8%) polyresistant and 3 (5.7%) were multidrug-resistant. In multivariate analysis, prior TB treatment (P &lt; 0.001), presence of atelectasis (P = 0.039) or lobar consolidation (P = 0.012) on chest X-ray were associated with DR-TB. DR-TB required longer treatment but there were no differences in rate of cure, treatment completion or death. The high rate of DR-TB underscores the importance of routine DST. History of treatment and drug susceptibility in source cases was useful in guiding initial treatment in children.
Open Forum Infectious Diseases, 2015
Journal of the Medical Association of Thailand = Chotmaihet thangphaet, 2001
In vitro killing activity of peracetic acid (Perasafe) at a concentration of 0.26 per cent w/v wa... more In vitro killing activity of peracetic acid (Perasafe) at a concentration of 0.26 per cent w/v was tested against Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, Salmonella paratyphi A, Acinetobacter baumannii, Sternotrophomonas maltophilia, Enterococcus faecium, Enterococcus faecalis, methicillin-resistant Staphylococcus aureus (MRSA), Bacillus subtilis spore, Mycobacterium tuberculosis and human immuno-deficiency virus type I. Exposure to Peracetic acid (0.26% w/v) for 10 minutes resulted in massive killing of all the aforementioned organisms and spore.
The Southeast Asian journal of tropical medicine and public health, 1997
Vertical transmission of HIV-1 is caused by multifactorial factors. To access the relationship of... more Vertical transmission of HIV-1 is caused by multifactorial factors. To access the relationship of viral factors involving in perinatal transmission of HIV-1 subtype E, which is the predominant type in Thailand, plasma viral load, blood CD4+ lymphocyte level, heteroduplex mobility, and V3 sequence of the HIV-1 envelope gene were studied in 32 transmitting and 25 non-transmitting mothers. We found that HIV-1 subtype E vertical transmission was strongly associated with high maternal plasma viral RNA (> 4 x 10(4) copies/ml) and high genetic diversity of envelope gene determined by heteroduplex mobility (< 0.9). The variation of nucleotide sequences in envelope gene of subtype E vertical transmission could not determine in V3 region. Hence, plasma viral load and heteroduplex mobility can be used as prediction factors in vertical transmission of HIV-1 subtype E.
The International Journal of Tuberculosis and Lung Disease, 2013
Few data on drug-resistant (DR) tuberculosis (TB) in children are available in Thailand. To evalu... more Few data on drug-resistant (DR) tuberculosis (TB) in children are available in Thailand. To evaluate the rate, clinical features and risk of DR-TB in children. Observational prospective study conducted in children diagnosed with TB at a tertiary care centre in Bangkok. Of 230 children diagnosed with TB, the median age was 6.5 years; 63% had identified adult source cases, and only 7% had received prior isoniazid treatment for latent tuberculous infection. Of the 195 (85%) specimens submitted, 57 (25%) were positive using culture or polymerase chain reaction. Of the 53 positive specimens available for drug susceptibility testing (DST), 18 (34%) had any resistance, 13 (24.5%) were mono-resistant, 2 (3.8%) polyresistant and 3 (5.7%) were multidrug-resistant. In multivariate analysis, prior TB treatment (P &lt; 0.001), presence of atelectasis (P = 0.039) or lobar consolidation (P = 0.012) on chest X-ray were associated with DR-TB. DR-TB required longer treatment but there were no differences in rate of cure, treatment completion or death. The high rate of DR-TB underscores the importance of routine DST. History of treatment and drug susceptibility in source cases was useful in guiding initial treatment in children.
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Papers by Suporn Foongladda