Surapee Tiengrim

Evaluation of an NS1 antigen detection for diagnosis of acute dengue infection in patients with acute febrile illness

Diagnosis of dengue infection during the febrile stage has been challenging. We evaluated the accuracy of NS1 protein detection in diagnosing dengue infection in patients presenting with acute febrile illness in Bangkok, Thailand. Of the 235 subjects presented with fever of unknown source within 5 days, 132 (56.2%) were male with the median age of 17.8 (range, 3-52) years. The median duration of fever was 4 (range, 1-5) days. One hundred seventy-one (72.8%) patients had dengue infection, of which 158 (92.4%) were secondary infections. The sensitivity of NS1 Ag test was 63.2% (95% confidence interval [CI], 55.7-70.0), and the specificity was 98.4% (95% CI, 91.7-99.7). The positive and negative predictive values were 99.0% and 52.5%, respectively. The immune complex dissociation by acid treatment increase sensitivity from 63.2% to 72%. In an endemic area, Plateliatrade mark NS1 Ag test has limited sensitivity but very high specificity for diagnosis of dengue infection in patients with acute febrile illness.

Prevalence of antibiotic resistant bacteria in healthy adults, foods, food animals, and the environment in selected areas in Thailand.

Abstract Objectives: The aim of this study was to determine the prevalence of antibiotic-resistant bacteria, especially extended-spectrum beta-lactamase (ESBL) producing Escherichia coli, in samples from healthy adults, foods, food animals, and the environment in selected areas of Thailand. Methods: Samples were collected from stool specimens from adult food factory and food animal farm workers, fresh and cooked foods sold at markets, rectal swabs of healthy pigs and chickens, fresh pork meat from slaughterhouses, water samples from canals as well as fish and shrimp farm ponds, and stagnant water sources on pig farms. Antibiotic susceptibility was determined using the disk diffusion or agar dilution methods. Extended-spectrum beta-lactamase production was assayed using a double disk diffusion method. Results: Among 544 healthy adult food factory workers, 75·5% were positive for ESBL producing E. coli, while 77·3% of E. coli isolated from 30 healthy animal farm workers were positive. Amongst healthy food animals, ESBL producing status among E. coli isolates were more commonly detected in pigs (76·7%) than broilers (40%). Extended-spectrum beta-lactamase producing E. coli seemed to be more prevalent in fresh meat samples than in fresh vegetables, in fresh foods than in cooked foods, and in water samples collected from the animal farms than those from canals and fish and shrimp ponds. Conclusions: Extended-spectrum beta-lactamase producing E. coli isolates are prevalent amongst healthy individuals, foods along the food production chain from farms to consumers, and in the environment in selected areas in Thailand.

Effect of different Mueller–Hinton agars on tigecycline disc diffusion susceptibility for Acinetobacter spp.

Sir, n nWe reported the in vitro activity of tigecycline against 148 strains of Acinetobacter spp. from the infectious diseases research laboratory at Siriraj Hospital, Bangkok, Thailand, which showed that only 3.4% of the Acinetobacter spp. strains were considered resistant to tigecycline due to their inhibition zone diameters ( 2 mg/L).1 The service microbiology laboratory of our hospital has reported tigecycline disc diffusion susceptibility results for Acinetobacter spp. based on the interpretative breakpoints proposed by Jones et al.,2 which indicated that most clinical isolates of Acinetobacter spp. were not susceptible to tigecycline. There were several observations on the effect of the susceptibility test media on the MICs of tigecycline. Hope et al.3 found that the MIC of tigecycline was raised in aged media. Fernandez-Mazarasa et al.4 reported that high concentrations of manganese in Mueller–Hinton agar (MHA) increased the MIC90 of tigecycline for A. baumannii determined by Etest from 1 to 4 mg/L. The service microbiology laboratory at Siriraj Hospital used MHA (Oxoid), whereas the infectious diseases research laboratory used MHA [Becton–Dickinson (BD)] for disc diffusion susceptibility for Acinetobacter spp. Therefore, a discrepancy in tigecycline susceptibility for Acinetobacter spp. might be due to a difference in the type of MHA. n nWe performed tigecycline disc diffusion susceptibility for 102 strains of Acinetobacter spp. isolated from different patients. These isolates were resistant to all β-lactams, aminoglycosides and fluoroquinolones. In vitro susceptibility of Acinetobacter spp. to tigecycline was determined by the Kirby–Bauer disc diffusion method using a paper disc containing 15 µg of tigecycline per disc (BD, USA). The MHAs were purchased from BD (Thailand) and Oxoid Company (Thailand), and they were freshly prepared. The methodology for susceptibility testing was performed by direct colony suspension according to the guidelines suggested by the CLSI.5 Quality control was performed by testing the susceptibility of Escherichia coli ATCC 25922. The susceptibility tests using both types of MHAs were performed concurrently under identical conditions. The comparison of tigecycline inhibition zone diameters on MHA (BD) and MHA (Oxoid) for 102 isolates of Acinetobacter spp. is shown in Figurexa01. The inhibition zone diameters observed on MHA (Oxoid) were consistently smaller than those on MHA (BD), with a mean difference of 3.5 mm and a range from 1 to 6 mm. The inhibition zone diameters on MHA (Oxoid) and MHA (BD) were significantly correlated (r = 0.95, P < 0.001). The distribution of tigecycline disc diffusion susceptibility for Acinetobacter spp. performed on MHA (BD) and MHA (Oxoid) is shown in Tablexa01. The susceptibility of Acinetobacter spp. to tigecycline using MHA (BD) was 86.2%, whereas that using MHA (Oxoid) was only 28.5%. We also measured the content of manganese in both types of MHAs by atomic absorption and found that the content of manganese in MHA (Oxoid) was three times more than that in MHA (BD). Therefore, the discrepancy in inhibition zone diameters between MHA (Oxoid) and MHA (BD) might be due to a difference in the manganese content in MHAs. However, there could be other associated factors for such a discrepancy, and more studies are required. The aforementioned observations warrant a clinical study to determine the efficacy of tigecycline for therapy of Acinetobacter spp. infections in order to consider which type of MHA is more appropriate for tigecycline disc diffusion susceptibility for Acinetobacter spp. Meanwhile, the results of tigecycline disc diffusion susceptibility for Acinetobacter spp. in MHA (Oxoid) should be cautiously reported and interpreted. n n n nFigurexa01 n nComparison of tigecycline inhibition zone diameters on MHA (BD) and MHA (Oxoid) for 102 isolates of Acinetobacter spp. n n n n n nTablexa01 n nDistribution of tigecycline disc diffusion susceptibility for Acinetobacter spp. performed on MHA (BD) and MHA (Oxoid)

Prevalence of Antibiotic Resistance in Fecal Flora of Patients Undergoing Transrectal Ultrasound-Guided Prostate Biopsy in Thailand

Objective: The objective of this study was to determine the prevalence of antibiotic resistance in fecal flora of patients undergoing transrectal ultrasound-guided needle biopsy of the prostate (TRUSB) and the factors associated with such antibiotic resistance. Methods: A prospective study of patients undergoing TRUSB was conducted. Rectal swabs were performed and sent for cultures and antibiotic susceptibility testing before TRUSB. Clinical characteristics were determined. Results: 287 Gram-negative isolates from 144 patients were identified, 80.1% were Escherichia coli and 13.9% were Klebsiella pneumoniae. 27 patients who received antibiotics within 3 months exhibited higher prevalence of organisms with extended-spectrum beta-lactamases (ESBL) production (40.7 vs. 22.2%) and ceftriaxone-resistance (48.1 vs. 28.2%). 134 patients received a short-course antibiotic prophylaxis in which fluoroquinolone (FQ) contributed to 89.6% of cases. Patients who received antibiotic prophylaxis showed a higher prevalence of organisms resistant to ceftriaxone (34.3 vs. 0%), ciprofloxacin (90.3 vs. 30%) and FQ (95.5 vs. 50%) and a trend of more ESBL production (27.6 vs. 0%). Conclusions: Previous antimicrobial use and prophylaxis with FQ are correlated with a higher prevalence of FQ and ceftriaxone resistance and ESBL production. A single dose of ceftriaxone without short-course FQ use is recommended as antibiotic prophylaxis in TRUSB.

Disseminated Cladophialophora bantiana infection in an idiopathic thrombocytopenic purpura patient: a case report.

Cladophialophora bantiana, a dematiaceous fungus (previously known as Cladosporium trichoides, Cladosporium bantiana, Xylohypha bantiana), was first described in a culture-proven case of cerebral phaeohyphomycosis by Binford et al. (Am J Clin Pathol 1952; 22: 535–42) in 1952. The fungus is well recognised as a neurotropic fungus, which usually causes fatal cerebral phaeohyphomycosis (Dixon DM et al., Chemotherapy 1987; 33: 129–40; Roche M et al., J Infect 2005; 51: e285–8). Cladophialophora bantiana is the most frequently isolated species of cerebral phaeohyphomycosis (Revankar SG et al., Clin Infect Dis 2004; 38: 206–16). However, it is extremely rare for this pathogen to cause a disseminated infection. Prior to our patient, there has been only one report of disseminated C. bantiana infection throughout the world (Keyser A et al., J Heart Lung Transplant 2002; 21: 503–5). We report the second case of disseminated C. bantiana infection in an idiopathic thrombocytopenic purpura (ITP) patient; this patient presented with cutaneous, pulmonary and cerebral lesions.

Thailand Antimicrobial Resistance Containment and Prevention Program

The Thailand Antimicrobial Resistance (AMR) Containment and Prevention Program was founded to develop, co-ordinate and implement AMR Containment and Prevention (AMRCP) operational actions in Thailand following the One Health approach. This article summarises the ten AMRCP operational actions initiated during the initial phase of the programme from 2012 to 2016: estimating the national AMR burden; establishing the dynamics of AMR chains to understand how AMR in Thailand develops and spreads; developing a national AMRCP infrastructure; developing laboratory and information technology systems for surveillance of AMR, antibiotic use and hospital-acquired infections; regulating the use and distribution of antibiotics in humans and food animals; generating local evidence for promoting responsible use of antibiotics and efficient practices for infection prevention and control; designing AMRCP campaigns; creating an AMRCP package; implementing the AMRCP package in selected pilot communities; and conducting research and development on diagnostics, therapy and prevention of antimicrobial-resistant bacterial infections. The programmes core campaign is to stop producing AMR by promoting responsible use of antibiotics, and to stop the acquisition and transmission of AMR by promoting good sanitation and hygiene as well as compliance with infection control and prevention practices.

Prevalence of the colistin resistance gene mcr-1 in colistin-resistant Escherichia coli and Klebsiella pneumoniae isolated from humans in Thailand

OBJECTIVESnHistorically, colistin has been considered a last-line therapeutic option against multidrug-resistant Gram-negative bacterial infections. However, chromosomally-encoded and plasmid-mediated colistin resistance is increasingly being reported worldwide. Spread of the plasmid-borne colistin resistance gene mcr-1 is of great concern since it can be transferred between bacteria. The aim of this study was to investigate the prevalence of mcr-1 in Escherichia coli and Klebsiella pneumoniae collected from human clinical specimens in Thailand during 2014-2017.nnnMETHODSnMinimum inhibitory concentrations (MICs) of colistin were determined by the broth microdilution method for 317 non-duplicate Enterobacteriaceae clinical isolates (37 E. coli and 280 K. pneumoniae). All isolates were screened for the mcr-1 gene by PCR.nnnRESULTSnThe colistin MIC50, MIC90 and MIC range for the 37 E. coli isolates were 0.5, 8 and 0.5-32mg/L, respectively. The mcr-1 gene was detected in 11 E. coli isolates (29.7%). Escherichia coli harbouring the mcr-1 gene had a colistin MIC range of 4-32mg/L. The colistin MIC50, MIC90, and MIC range for the 280 K. pneumoniae isolates were 32, >128, and 0.25 to >128mg/L, respectively. The mcr-1 gene was detected in 4 K. pneumoniae isolates (1.4%). Klebsiella pneumoniae harbouring the mcr-1 gene had a colistin MIC range of 4-64mg/L.nnnCONCLUSIONSnThis is the first report on the prevalence of the mcr-1 gene in colistin-resistant E. coli and K. pneumoniae isolated from humans in Thailand. These data provide added insight into the mechanism of colistin resistance among Enterobacteriaceae pathogens.

Evaluation of the Rapid Polymyxin NP test for detection of colistin susceptibility in Enterobacteriaceae isolated from Thai patients

Development and evaluations of the Rapid Polymyxin NP test for detection of colistin resistance in Enterobacteriaceae have been recently reported. In this study, we evaluated the performance of the test using a larger number of Enterobacteriaceae, and a larger proportion of isolates with a colistin MIC close to the breakpoint. Out of 339 isolates, the Rapid Polymyxin NP test detected colistin resistance in 13 isolates of Escherichia coli, 213 isolates of Klebsiella pneumoniae, 9 isolates of Enterobacter aerogenes, and 10 isolates of the other Enterobacteriaceae species. Sensitivity and specificity of the test for detecting colistin resistance were 100% and 95.9%, respectively. Positive predictive value and negative predictive value were 98.3% and 100%, respectively.