Clostridium difficile ribotype 126 in southern Taiwan: a cluster of three symptomatic cases.

INTRODUCTION: Several virulent Clostridium difficile clones, designated as polymerase chain reaction (PCR) ribotypes 017, 027, or 078, are well recognized in western countries. However, the ribotype distribution of clinical C. difficile isolates in Taiwan remains unclear. METHOD: Between 2010 and 2012, we identified three patients with C. difficile-associated diarrhea (CDAD) at a hospital in southern Taiwan. The C. difficile strains isolated from these patients were further characterized by PCR detection of tcdA, tcdB, tcdC, cdtA, and cdtB, toxinotyping, multilocus sequence typing, ribotyping and repetitive-based PCR. RESULTS: Three C. difficile strains harbored tcdCΔ39 and belonged to multilocus sequence typing 11 (ST11), toxinotype V, and ribotype 126 (a ribotype 078-like clone). Notably, one patient developed pseudomembranous colitis and recurrent CDAD. These three isolates were noted between January 2012 and June 2012 and were identical, as evidenced by repetitive sequence-based PCR, suggestive of case clustering. CONCLUSION: A hypervirulent C. difficile clone, ribotype 126, causing pseudomembranous colitis and recurrent CDAD, is present in southern Taiwan.

Simultaneous Quantitation of Seven Phenethylamine-Type Drugs in Forensic Blood and Urine Samples by UHPLC-MS-MS.

Abuse of new psychoactive substances (NPS) has become a health and social issue of global concern. p-Methoxyamphetamine (PMA)/p-methoxymethamphetamine (PMMA) with fluoro- or chloro-derivatives of amphetamine and methamphetamine were among the most common drugs found in specimens from fatal cases in Taiwan during the January 2011 to December 2018 period. A liquid-liquid extraction sample preparation protocol with highly sensitive ultra-high performance liquid chromatography-tandem mass spectrometry approach was developed for the simultaneous analysis of seven phenethylamine-type drugs-PMA, PMMA, p-methoxyethylamphetamine, 4-fluoroamphetamine (4-FA), 4-fluoromethamphetamine (4-FMA), 4-chloroamphetamine (4-CA) and 4-chloromethamphetamine (4-CMA)-in postmortem blood and urine specimens. Separation by liquid chromatography was performed by Agilent Zorbax SB-Aq column. Tandem mass spectrometry was operated in Agilent Jet Stream Technology electrospray ionization in positive-ion multiple reaction monitoring mode. An analytical methodology was evaluated using drug-free blood and urine after fortification with 100-2,000 ng/mL of the seven target analytes. Average extraction recoveries were >80%; slightly higher ion suppression was observed for PMA and 4-CA; intra-/inter-day precision (% coefficient of variation) and accuracy were in the ranges of 0.52-12.3% and 85-110%, respectively. Limit of detection and lower limit of quantitation for these seven analytes were both in the 0.5-5 ng/mL range. Interference and carryover were not significant. This relatively simple methodology was found effective and reliable for routine identification and quantitation of these seven analytes in postmortem and antemortem blood and urine specimens received in 2018. Analytical data obtained from these actual cases indicated the following: (i) compared to findings reported during the 2007-2011 period, the use of substituted phenethylamine-type drugs decreased in 2018; (ii) ketamine and 7-aminonimetazepam (the main metabolite of nimetazepam) were the most common co-ingested substances in specimens containing PMA/PMMA, 4-FA/4-FMA, or 4-CA/4-CMA; and (iii) in drug fatalities, the concentration of PMA was significantly higher than the concentration of PMMA in both urine and blood, while the reverse was true in urine specimens from antemortem cases.

Clostridioides difficile infection in patients with hematological malignancy: A multicenter study in Taiwan.

BACKGROUND: Among the individuals with hematological malignancy (HM) complicated with Clostridioides difficile infection (CDI), the variables associated with in-hospital mortality and recurrence of CDI were investigated. MATERIAL AND METHODS: Including adults with HM and those without malignancy suffering from CDI from January 2015 to December 2016 in three hospitals in Taiwan. RESULTS: Totally 314 patients including 77 with HM and 237 patients without malignancy were included. HM patients more often had low leukocyte counts (<500 cells/mL: 28.6% vs. 2.1%) than those without malignancy and more patients without malignancy had severe CDI than patients with HM (31.6% vs. 14.3%, P = .003), according to the severity score of IDSA/SHEA. Patients with HM had a higher recurrence rate of CDI (14.3%, 11/77 vs. 7.2%, 17/237; P = .07) and longer hospital stay (47.2 ± 40.8 days vs. 33.3 ± 37.3 days; P = .006) than those without malignancy. In the multivariate analyses for those with HM and CDI, the in-hospital mortality was associated with vancomycin-resistant Enterococcus (VRE) colonization or infection (odds ratio [OR] 7.72; P = .01), and C. difficile ribotype 078 complex infection (OR 9.22; P = .03). Moreover underlying hematological malignancy (OR 2.74; P = .04) and VRE colonization/infection (OR 2.71; P = .02) were independently associated with CDI recurrence. CONCLUSION: Patients with HM complicated with CDI were often regarded as non-severe infection, but had a similar in-hospital mortality rate as those without malignancy. CDI due to ribotype 078 complex isolates heralded a poor prognosis among HM patients.

Risk factors of Clostridium difficile-associated diarrhea in hospitalized adults: Vary by hospitalized duration.

BACKGROUND: Clostridium difficile is the leading cause of nosocomial infectious diarrhea. Hospitalized patients were at risk of C. difficile-associated diarrhea (CDAD). However the risk factors of CDAD in patients with different hospitalization period are not clear. MATERIAL AND METHODS: A prospective investigation was conducted in medical wards of a district hospital in southern Taiwan, from January 2011 to January 2013. We arbitrary divided patients into two groups: hospitalized for at most 14 days and 15-30 days, and analyzed their risk factors for CDAD. RESULTS: Overall 451 patients were enrolled. The multivariable analysis of 19 (8.0%) patients developing CDAD within 14 days' hospital stay and 216 patients hospitalized for ≤ 14 days without CDAD showed malignancy (odds ratio [OR] 7.15, 95% confidence interval [CI] 1.82-28.09; P = 0.005), prior cephalosporin (OR 10.8, 95% CI 1.3-93.9; P = 0.03) and proton pump inhibitor (PPI; OR 7.1, 95% CI 2.1-24.7; P = 0.002) therapy were independently related to CDAD (Table 3), but hypertension (OR 0.2, 95% CI 0.1-0.7; P = 0.01) was reversely related to CDAD. However, of 9 (4.2%) patients developing CDAD later (15-30 days' hospital stay) and 207 patients with longer hospitalization (15-30 days) but free of CDAD, malignancy (OR 14.0, 95% CI 1.6-124.9; P = 0.02) and underlying diabetes mellitus (OR 20.5, 95% CI 2.9-144.9; P = 0.002) were independent risk factors of CDAD. CONCLUSION: Risk factors for CDAD among hospitalized patients varied by the duration of hospital stay. Intervention strategies to prevent CDAD may be different in terms of hospital stay duration.

Rapid screening and confirmation of drugs and toxic compounds in biological specimens using liquid chromatography/ion trap tandem mass spectrometry and automated library search.

Recent advances in liquid chromatography/tandem mass spectrometry (LC/MS/MS) technology have provided an opportunity for the development of more specific approaches to achieve the 'screen' and 'confirmation' goals in a single analytical step. For this purpose, this study adapts the electrospray ionization ion trap LC/MS/MS instrumentation (LC/ESI-MS/MS) for the screening and confirmation of over 800 drugs and toxic compounds in biological specimens. Liquid-liquid and solid-phase extraction protocols were coupled to LC/ESI-MS/MS using a 1.8-microm particle size analytical column operated at 50 degrees C. Gradient elution of the analytes was conducted using a solvent system composed of methanol and water containing 0.1% formic acid. Positive-ion ESI-MS/MS spectra and retention times for each of the 800 drugs and toxic compounds were first established using 1-10 microg/mL standard solutions. This spectra and retention time information was then transferred to the library and searched by the identification algorithm for the confirmation of compounds found in test specimens - based on retention time matches and scores of fit, reverse fit, and purity resulting from the searching process. The established method was found highly effective when applied to the analyses of postmortem specimens (blood, urine, and hair) and external proficiency test samples provided by the College of American Pathology (CAP). The development of this approach has significantly improved the efficiency of our routine laboratory operation that was based on a two-step (immunoassay and GC/MS) approach in the past.

Development of an information-rich LC-MS/MS database for the analysis of drugs in postmortem specimens.

With several instrument configurations available from various manufacturers, liquid chromatography-tandem mass spectrometry (LC-MS/MS) technology is currently intensively studied for comprehensive drug screen and confirmation. An LC-MS/MS database, including 780 drug and toxic compounds, has been constructed, featuring information-rich MS/MS spectra derived from a novel fragmentation approach incorporating voltage ramping and broadened mass window for activation. The resulting spectra are rich in high- and low-mass fragment ions, highly effective for matching and proven reproducible over a 6 month test period. Coupled to effective sample preparation protocols, the database-searching process greatly improved the identification of drugs in postmortem specimens by the LC-electrospray ionization (ESI)-MS/MS technology. This method has significantly improved the efficiency of our routine laboratory operation that was based on a two-step [fluorescence polarization immunoassay (FPIA) and gas chromatography/mass spectrometry (GC/MS)] approach in the past.

Methylenedioxymethamphetamine-related deaths in Taiwan: 2001-2008.

Methylenedioxymethamphetamine (MDMA) has been one of most popular drugs in the "club" scene in Taiwan. This epidemic was studied through the examination of toxicological data obtained from the 59 fatalities tested positive for MDMA during the period of January 2001 to December 2008. Ketamine was found in 28 of these cases, signifying the popularity of this drug in Taiwan. The annual number of deaths in each of the 8 years in this period was 4, 7, 9, 14, 8, 9, 2, and 6, respectively. Among these 59 deaths, 39 (66.1%) were men, and the mean, median, and range of ages were 24.6, 23, and 14-46, respectively. Causes of death ruled by the attending pathologists and the distributions for these fatalities were acute intoxication, 40 and mechanical injury, 19, including 3 hanging and 2 drowning. The manners of death were ruled as accidental, 44; homicidal, 6; suicidal, 7; and undetermined, 2. In this study, postmortem whole blood was analyzed by gas chromatography-mass spectrometry with a limit of quantitation at 0.05 microg/mL for both MDMA and MDA. The mean, median, and range of MDMA concentrations in the cases, where MDMA acute intoxication was ruled as the cause of death, were 4.75, 2.60, and 0.12-40.41 microg/mL. MDA was found in 30 of these 40 cases with the following mean, median, and range data: 0.19, 0.13, and 0.05-1.81 microg/mL. The corresponding data of MDMA and MDA in the remaining 19 MDMA-related deaths were significantly lower: 1.25, 0.97, 0.08-3.05 and 0.11, 0.09, 0.06-0.24 microg/mL, respectively.

Nationwide surveillance of ribotypes and antimicrobial susceptibilities of toxigenic Clostridium difficile isolates with an emphasis on reduced doxycycline and tigecycline susceptibilities among ribotype 078 lineage isolates in Taiwan.

OBJECTIVES: The information of antimicrobial susceptibility, toxin gene, and ribotype distribution of toxigenic Clostridium difficile isolates in Taiwan remain limited. PATIENTS AND METHODS: The study was conducted from January 2015 to December 2016 in 5 hospitals in Taiwan. Adults aged ≥20 years with a hospital stay for >5 days were included, and those with colectomy or intestinal infection due to other enteropathogens were excluded. Multiplex PCR was used to detect tcdA, tcdB, cdtA, cdtB, and tcdC deletions, and antimicrobial susceptibility for metronidazole, vancomycin, doxycycline, and tigecycline was investigated. Ribotypes of those isolates with tcdC deletion and tcdA+/tcdB+ were determined. RESULTS: Of 1112 C. difficile isolates collected from adults at 5 hospitals, 842 were toxigenic, including 749 (89.0%) tcdA+/tcdB+ isolates and 93 (11.0%) tcdA-/tcdB+. Of the toxigenic isolates, 76 (9.0%) had a tcdC deletion and were cdtA+/cdtB+, indicative of hypervirulence, and RT078 lineage, including RT126, RT127, and RT078, predominated (n=53, 76.3%). Similar to the susceptibility data in Asia countries, metronidazole or vancomycin resistance was rare, noted in 1.2% or 2.1%, respectively. Reduced doxycycline susceptibility (minimum inhibitory concentration [MIC] of ≥8 mg/L) was more common among RT078 lineage than non-RT078 lineage (75.9%, 44/58 vs 6.0%, 47/784; P<0.001). Also reduced tigecycline susceptibility (MIC ≥0.125 mg/L) was more common among RT078 lineage (20.7%, 12/58 vs 6.5%, 51/784; P<0.001). CONCLUSION: In Taiwan, toxigenic C. difficile isolates remain susceptible to metronidazole and vancomycin. RT078 lineage predominated among toxigenic isolates with cdtA, cdtB, and tcdC deletion, and more often had reduced doxycycline and tigecycline susceptibility than the isolates other than RT078 lineage.

Recent paramethoxymethamphetamine (PMMA) deaths in Taiwan.

Paramethoxyamphetamine (PMA) and paramethoxymethamphetamine (PMMA) are methoxylated phenylethylamine derivatives that have been banned in Taiwan since December 2005. The case history and pathological and toxicological findings of eight recent PMMA fatalities were investigated. All specimens from these cases were initially identified by an AxSYM fluorescence polarization immunoassay screening test for amphetamines with a 300 ng/mL cutoff. Specimens screened positive were confirmed and quantitated by gas chromatography-mass spectrometry. The mean age of these PMMA-related fatalities was 18.9 +/- 4.4 years in the range of 14-25. Seven (87.5%) of these eight cases were men. The mean, standard deviation, and range of PMA found in the heart blood collected from these 8 cases were 0.213, 0.144, and 0.079-0.489 microg/mL, respectively. The corresponding data for PMMA were 4.312, 4.806, and 1.208-15.824 microg/mL, respectively. Other drugs, such as MDA, MDMA, ketamine, norketamine, hydroxymidazolam, methamphetamine, and pentobarbital, were also found in these cases.

Developing a UHPLC-QTOF-MS and Automated Library Search Method for Screening Drugs and Toxic Compounds in Postmortem Specimens.

Screening and confirming the presence of drugs and toxic compounds in various matrices are important and challenging tasks routinely faced by forensic and clinical laboratories. Recent advances in the liquid chromatographic and mass spectrometric technologies have provided an opportunity for the development of more specific and effective approaches to achieve the "screening" and "confirmation" goals in a single analytical step. The objectives of this study are: (i) the establishment of an ultra-high performance liquid chromatographic, quadrupole time-of-flight mass spectrometric mass spectrometric and MS-MS spectral database, including 1,200 compounds of interest; and (ii) the development of an effective protocol, using this database and three searching algorithms, for general unknown screening of these compounds. The established database and protocol were evaluated through the analysis of 30 external proficiency test and 100 postmortem samples and found to be significantly more effective than the LC-IT-MS and GC-MS approaches previously established in our laboratory.

Simultaneous Quantitation of Methamphetamine, Ketamine, Opiates and their Metabolites in Urine by SPE and LC-MS-MS.

Heroin, methamphetamine and ketamine have been the most commonly abused drugs in Taiwan. The presence of these drugs and their metabolites in postmortem specimens has been routinely monitored in our laboratory mostly by gas chromatographic-mass spectrometric methods. This study aimed to evaluate a more effective approach to simultaneously quantify these analytes (i.e., amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), morphine, codeine, 6-acetylmorphine, 6-acetylcodeine, ketamine and norketamine) in postmortem urine and blood specimens by liquid chromatography-tandem mass spectrometry (LC-MS-MS). Samples (1 mL) were extracted via solid-phase extraction, evaporated and reconstituted in the mobile phase for injection into the LC-MS-MS system. Respective deuterated analogs of these analytes were used as internal standards. Chromatographic separation was achieved by an Agilent Zorbax SB-Aq analytical column at 50°C. Mass spectrometric analysis was performed by electrospray ionization in positive-ion dynamic multiple reaction monitoring mode with optimized collision energy for respective precursor ion selected for each analyte, and the monitoring of two transition ions. Performance characteristics were assessed using drug-free samples that were fortified with 50-1,000 ng/mL of the 10 analytes. Analytical parameters evaluated and resulting data are as follows: (i) average extraction recoveries (n= 3) were better than 80%, except for MDMA (71%) and morphine (74%); (ii) inter-day and intra-day precision ranges (%CV) were 1.59-8.80% and 0.57-3.89%, respectively; (iii) calibration linearity (r2), detection limit and quantitation limit for all analytes were >0.999, 1 and 5 ng/mL, respectively; (iv) matrix effects (ion suppression) were observed for three analytes, but were satisfactorily compensated for by the deuterated internal standards adopted in the analytical protocol. This method was successfully applied to the analysis of specimens collected from unknown death cases from various district prosecutors' offices in Taiwan, and was also found helpful to understanding whether the detected opiates were derived from heroin or legal morphine/codeine-containing medications.

Distribution of methylenedioxymethamphetamine (MDMA) and methylenedioxyamphetamine (MDA) in postmortem and antemortem specimens.

With increasing requests for the analysis of various specimens related to fatal and non-fatal abuse of methylenedioxymethamphetamine (ecstasy, MDMA), the toxicology laboratory of the Institute of Forensic Medicine has established protocols for the analysis of MDMA and related compounds in hair, urine, and various postmortem specimens. Analytical protocols include extraction, derivatization, and gas chromatographic-mass spectrometric analysis adapting deuterated analogs of the analytes as internal standards. Data resulting from these analyses and hereby reported include postmortem distribution of MDMA and methylenedioxyamphetamine (MDA) in heart blood, gastric content, urine, and bile specimens from 20 fatal cases; other drugs found in the heart blood from these 20 cases; and the distribution of MDMA and MDA in 25 antemortem urine and 6 hair specimens. The MDA/MDMA concentration ratio observed in a limited number of hair specimens (n=6) are consistent and appear to be higher than those found in other specimens. Compared to other commonly abused drugs (e.g., cocaine and heroin), the "drug/metabolite" concentration ratio (MDMA/MDA) in hair is not significantly different from the ratios derived from other specimens, such as urine and blood. This observation is consistent with the relative drug/metabolite incorporation rates reported for cocaine/benzoylecgonine, tetrahydrocannabinol/tetrahydrocannabinoic acid, and MDMA/MDA.

Urinary excretion of morphine and codeine following the administration of single and multiple doses of opium preparations prescribed in Taiwan as "brown mixture".

Parallel to the "poppy-seed defense" strategy commonly reported in the United States, donors of urine samples tested positive for opiates in Taiwan often claimed the consumption of Brown Mixture (BM) as the source of the observed morphine and codeine. Because BM contains opium powder (10.0-10.5% morphine), opium tincture (0.9-1.1% morphine), or camphorated opium tincture (0.045-0.055% morphine) and is a popular remedy, and heroin use is considered a serious criminal act, the claim of BM use has to be adequately addressed. In this study, BM from seven different manufacturers (5 tablets and 2 solutions) and urine samples from alleged heroin users and volunteers with various ingestion patterns and were analyzed for their morphine and codeine contents. The analytical procedure included hydrolysis, trimethylsilylation, and gas chromatography-mass spectrometry analysis. The contents of morphine and codeine in the tablets were found to be very consistent, but with significant differences in the two BM solutions. Morphine concentrations found in urine specimens collected from volunteers ingesting BM tablets (or solutions) were always < 4000 ng/mL. The following morphine-to-codeine ([M]/[C]) ratios were observed for urine specimens with morphine concentration > or = 300 ng/mL: (A) < 3.0 for volunteers ingesting BM solution and (B) > 3.0 (mostly > 5.0) for volunteers ingesting BM tablets and alleged heroin users. It appeared that (A) BM ingestion (tablet or solution) was unlikely to result in a morphine concentration > 4000 ng/mL; and (B) [M]/[C] ratio might not be an effective parameter to differentiate heroin use from BM tablet ingestion.

Simultaneous Determination and Quantitation of Paraquat, Diquat, Glufosinate and Glyphosate in Postmortem Blood and Urine by LC-MS-MS.

A simple method, incorporating protein-precipitation/organic backwashing and liquid chromatography-tandem mass spectrometry (LC-MS-MS), has been successfully developed for the simultaneous analysis of four highly water-soluble and less volatile herbicides (paraquat, diquat, glufosinate and glyphosate) in ante- and postmortem blood, urine and gastric content samples. Respective isotopically labeled analogs of these analytes were adopted as internal standards. Acetonitrile and dichloromethane were used for protein precipitation and organic solvent backwashing, respectively, followed by injecting the upper aqueous phase into the LC-MS-MS system. Chromatographic separation was achieved using an Agilent Zorbax SB-Aq analytical column, with gradient elution of 15 mM heptafluorobutyric acid and acetonitrile. Mass spectrometric analysis was performed under electrospray ionization in positive-ion multiple reaction monitoring mode. The precursor ions and the two transition ions (m/z) adopted for each of these four analytes were paraquat (185; 169 and 115), diquat (183; 157 and 78), glufosinate (182; 136 and 119) and glyphosate (170; 88 and 60), respectively. Analyte-free blood and urine samples, fortified with the analytes of interest, were used for method development/validation and yielded acceptable recoveries of the analytes; interday and intraday precision and accuracy data; calibration linearity and limits of detection and quantitation. This method was successfully incorporated into an overall analytical scheme, designed for the analysis of a broad range of compounds present in postmortem samples, helpful to medical examiners' efforts to determine victims' causes of death.

Antimicrobial susceptibility of clinical Enterobacteriaceae isolates at the emergency department in a regional hospital: A threat of extended spectrum beta-lactamase-producers among nursing home residents.

BACKGROUND/PURPOSE: The prevalence of extended spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae in nursing home residents has rarely been reported in Taiwan. METHODS: A retrospective study was performed at medical wards of a district hospital at southern Taiwan between July 2009 and June 2011. Patients were included if they were older than 18 years, admitted via the emergency department, and their blood, sputum, or urine culture revealed the growth of Escherichia coli, Klebsiella pneumoniae, or Proteus mirabilis. From each patient only the first isolate from the infection site was included. Antimicrobial susceptibility was determined using the disc diffusion method. RESULTS: Overall, 827 patients were included, with 354 (42.8%) coming from the community and 473 (57.2%) referred from a nursing home. Of the isolates acquired in nursing home, 45.5% (215/473) harbored ESBL. By contrast, 20.6% (73) of 354 isolates acquired in the community exhibited the ESBL production phenotype (p < 0.001). Of the isolates obtained from blood, urine, or sputum, 28.2% (37/131), 36.0% (208/578), or 36.4% (43/118) harbored ESBL, respectively, whereas 41% (211) of 515 E. coli isolates, 34.3% (72) of 210 K. pneumoniae, and 4.9% (5) of 102 P. mirabilis had ESBL. In general, the isolates from a nursing home or those with ESBL had lower antimicrobial susceptibility rates than those from the community or those without ESBL production. Only amikacin, piperacillin/tazobactam, ertapenem, and imipenem/meropenem were active against >90% Enterobacteriaceae isolates, irrespective of ESBL production. CONCLUSION: ESBL production was common among clinical Enterobacteriaceae isolates, especially E. coli or those isolated from nursing home residents.

Predominance of Clostridium difficile Ribotypes 017 and 078 among Toxigenic Clinical Isolates in Southern Taiwan.

Ribotypes and toxin genotypes of clinical C. difficile isolates in Taiwan are rarely reported. A prospective surveillance study from January 2011 to January 2013 was conducted at the medical wards of a district hospital in southern Taiwan. Of the first toxigenic isolates from 120 patients, 68 (56.7%) of 120 isolates possessed both tcdA and tcdB. Of 52 (43.3%) with tcdB and truncated tcdA (tcdA-/tcdB+), all were ribotype 017 and none had binary toxin or tcdC deletion. Eighteen (15%) toxigenic isolates harbored binary toxins (cdtA and cdtB) and all had tcdC deletion, including Δ39 (C184T) deletion (14 isolates), Δ18 in-frame deletion (3 isolates), and Δ18 (Δ117A) deletion (1 isolate). Eleven of 14 isolates with Δ39 (C184T) deletion belonged to the ribotype 078 family, including ribotype 127 (6 isolates), ribotype 126 (4 isolates), and ribotype 078 (1 isolate). Among 8 patients with consecutive C. difficile isolates, these isolates from 6 (75%) patients were identical, irrespective of the presence or absence of diarrhea, suggestive of persistent fecal carriage or colonization. In conclusion in southern Taiwan, ribotype 017 isolates with a tcdA-/tcdB+ genotype were not uncommon and of C. difficile isolates with binary toxin, the ribotype 078 family was predominant.

Urinary excretion of alpha-hydroxytriazolam following a single dose of halcion.

As an approved medicinal product and reportedly an abused substance that have been associated with death and "considered to be a factor...of impaired driving, sexual assault, and other violent crimes", triazolam is controlled at the same level (Level III) as flunitrazepam in Taiwan. Alleged misuses of this substance have been associated with case specimens submitted to this laboratory. A sample preparation (with and without enzymatic hydrolysis) and gas chromatography-mass spectrometry protocols were evaluated and applied to the analysis of free and total alpha-hydroxytriazolam (the main metabolite of triazolam) in urine. Ions designated for TMS-derivatized alpha-hydroxytriazolam and alpha-hydroxytriazolam-d4 are m/z 415, 417, and 430 and 419, 421, and 434, respectively. The overall protocol achieved the following results when applied to the analysis of 2-mL drug-free urine specimens fortified with 10-200 ng/mL alpha-hydroxytriazolam: recovery, 95%; interday and intraday precision ranges, 1.50-3.52% and 0.93-4.71%, respectively; linearity, r2 > 0.99; and limits of detection and quantitation, 0.05 and 0.1 ng/mL, respectively. This protocol was applied to the analysis of case specimens and urine samples collected from two patients (A and B) taking one oral dose of Halcion (0.25 mg triazolam). Excretion profiles of free and total alpha-hydroxytriazolam show that free alpha-hydroxytriazolam is detectable, but at very low levels (< 5 ng/mL). Peak excretion of total alpha-hydroxytriazolam occurs at approximately 5-10 h following the drug intake. Total alpha-hydroxytriazolam is excreted at detectable levels approximately 2-35 h following an oral dose of 0.25 mg triazolam. Total free and conjugated alpha-hydroxytriazolam excreted by A and B are 0.61% and 31.6%; and 0.36% and 57.2% of the dose, respectively.

Simultaneous quantitation of amphetamines and opiates in human hair by liquid chromatography-tandem mass spectrometry.

In this study, an incubation, solid-phase extraction (SPE) and LC-MS-MS procedure was developed, validated and used for simultaneous analysis of amphetamine (AP), methamphetamine (MA), morphine (MOR), codeine (COD), 6-acetylmorphine (6-AM) and 6-acetylcodeine (6-AC) in hair. Hair samples were initially cut into sections, washed with dichloromethane, then sonicated in a methanol-trifluoroacetic acid mixture. The resulting solutions were processed with a SPE procedure before undergoing LC-MS-MS analysis. Mass spectrometric analysis was performed in positive-ion, multiple reactions monitoring (MRM) mode, using appropriate collision energy for each selected precursor ion. The overall protocol, when applied to the analysis of hair (50 mg) samples fortified with 100-10,000 pg/mg of the analytes, was found to achieve 55.5-74.6% recovery of the six analytes with the following analytical parameters: (i) intra- and interday precision/accuracy data for the six analytes in the 1.6-7.6%/-6.0-12.8% and 1.3-6.6%/-6.9-9.3% ranges, respectively; (ii) r(2) > 0.998 for all six analytes and (iii) LOD 2 pg/mg for AP and MA, and 8 pg/mg for MOR, COD, 6-AM and 6-AC; LOQ 10 pg/mg for all six analytes. This method was then utilized to (i) analyze hair samples collected from 86 self-reported drug users and (ii) evaluate the deposition pattern of drugs in head hairs from four female MA and heroin users in a rehabilitation facility. This relatively simple protocol was found superior over the GC-MS methods we have previously developed and utilized in our laboratory for the analysis of these six analytes.

Risk factors for Clostridium difficile-associated diarrhea among hospitalized adults with fecal toxigenic C. difficile colonization.

BACKGROUND: Patients with toxigenic Clostridium difficile colonization (tCDC) are at risk of developing C. difficile-associated diarrhea (CDAD). However, the risk factors of hospitalized patients with tCDC developing CDAD are not clear. METHODS: We conducted an 18-month prospective study at a medical ward in a district hospital in southern Taiwan. Within 48 hours of admission, weekly stool samples from asymptomatic hospitalized patients were obtained to detect fecal CDC. A polymerase chain reaction for tcdB was performed to determine toxigenic isolates. CDAD was diagnosed if the patient had diarrhea and toxigenic C. difficile present in a stool sample. RESULTS: A total 483 patients with stool samples were eligible for the study. Eighty-six (17.8%) patients had tCDC after screening, of whom 14 (16.3%) developed CDAD during follow-up. Among those with tCDC, patients with subsequent CDAD were more likely to have diabetes mellitus (p = 0.01) and to have received piperacillin-tazobactam (p = 0.04), or proton-pump inhibitors (PPIs; p = 0.04) than those without developing CDAD. The variables were statistically significant as determined by multivariate analysis. However, the 60-day crude mortality rates among tCDC patients with and without subsequent development of CDAD were similar. CONCLUSION: Diabetes mellitus and recent receipt of piperacillin-tazobactam or PPIs are independent risk factors for the development of CDAD among hospitalized patients with tCDC.

Direct Injection LC-MS-MS Analysis of Opiates, Methamphetamine, Buprenorphine, Methadone and Their Metabolites in Oral Fluid from Substitution Therapy Patients.

A rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed, validated and applied to simultaneous analysis of oral fluid samples for the following 10 analytes: methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), buprenorphine, norbuprenorphine, morphine, codeine, 6-acetylmorphine, 6-acetylcodeine, amphetamine, and methamphetamine. The oral fluid sample was briefly centrifuged and the supernatant was directly injected into the LC-MS-MS system operated under reverse-phase chromatography and electrospray ionization (ESI). Deuterated analogs of the analytes were adopted as the internal standards and found to be effective (except for buprenorphine) to compensate for potential matrix effects. Each analytical run took <10 min. Linearity range (r(2) > 0.99) established for buprenorphine and the other nine analytes were 5-100 and 1-100 ng/mL. Intra- and interday precision (% CV) ranges for the 10 analytes were 0.87-12.2% and 1.27-12.8%, while the corresponding accuracy (%) ranges were 91.8-113% and 91.9-111%. Limits of detection and quantitation established for these 10 analytes were in the ranges of 0.1-1.0 and 0.25-1.0 ng/mL (5 ng/mL for buprenorphine). The method was successfully applied to the analysis of 62 oral fluid specimens collected from patients participating in methadone and buprenorphine substitution therapy programs. Analytical results of methadone and buprenorphine were compared with data derived from GC-MS analysis and found to be compatible. Overall, the direct injection LC-MS-MS method performed well, permitting rapid analysis of oral fluid samples for simultaneous quantification of methadone, buprenorphine, opiate and amphetamine drug categories without extensive sample preparation steps.