Gold blot for detection of immunoglobulin M (IgM)- and IgG-specific antibodies for rapid serodiagnosis of melioidosis

Abstract

Gold blot tests for rapid serodiagnosis of melioidosis were developed and evaluated with sera from 40 melioidosis patients and 159 normal controls. The sensitivity and specificity were 87.5 and 88%, respectively, for the immunoglobulin M (IgM) test and 100 and 91%, respectively, for the protein A test for IgG. Combination of the IgM gold blot and protein A gold blot yielded 97.5% sensitivity and 94.3% specificity. The tests were rapid and simple. Melioidosis, a disease caused by a gram-negative bacillus, Pseudomonas pseudomallei, ranges from subclinical to acute septicemic forms (2). Patients with acute septicemic melioidosis suffer from a high mortality rate. Survival depends on rapid diagnosis (2), which is supported by rapid serodiagnosis. Unfortunately, available serodiagnostic tests are not completely satisfactory. Indirect hemagglutination (IHA) is interfered with by a high background titer among normal patients in the endemic area (7) and reacted negatively in some septicemic melioidosis (2, 6). IHA combined with indirect enzyme-linked immunosorbent assay (ELISA) for immunoglobulin M (IgM) antibody (IgM ELISA) was more useful (6); however, ELISA was not rapid or simple. In this communication, an IgM-specific and an IgG-specific gold blot for melioidosis are described. Patient group. Single serum specimens were collected from 40 patients (22 females and 18 males) with melioidosis. Diagnosis was confirmed by the isolation of P. pseudomallei from hemoculture in 26 patients, from respiratory tract (throat swab, sputum, pleural fluid, and lung abscess) in 7 patients, from liver abscess in 5 patients, and from cutaneous abscess in 2 patients. All patients were farmers native to northeastern Thailand. The mean age was 40.3 years (range, 12 to 64 years). Diabetes melitus was presented in 12 (26%) patients. Sera were collected from 1 to 84 days (mean, 21.3 days) after the onset of fever. Control group. Sera from 159 migrant laborers from the northeast of Thailand were used as normal controls. Their physical findings, chest X rays, complete blood counts, urinalyses, and fecal examinations were normal. IgM gold blot. Antigen for gold blot and ELISA was prepared from a locally isolated strain of P. pseudomallei by heat and ultrasonic treatments as previously described (6). The gold blot method was modified from that of Brada and Roth (1). Nitrocellulose sheet (0.45 ,um pore size; Schleicher & Schuell, Dassel, Germany) was cut into strips (1 by 10 cm), and then 10 dot markers were marked on each strip by an HB pencil. Each strip was placed into the groove in the

Identification of specific antigens of Pseudomonas pseudomallei and evaluation of their efficacies for diagnosis of melioidosis

“…However, it was surprising to observe that with the present assay system with an acute-phase serum, the detection of IgG antibody was more reliable than detection of IgM antibody. Our data were different from those presented earlier by other investigators reporting more satisfactory results with IgM antibody detection (5,11,12). It is possible that our patients had been exposed to previous subclinical P. pseudomallei infections and that the current episode represented a reinfection.…”

Gold nanoparticles in biomedical applications: recent advances and perspectives

“…Sometimes, several labels are used simultaneously (e.g., colloidal gold and peroxidase or alkaline phosphatase) for the detection of multiple antigens on a membrane. 161 Colloidal gold in membrane assays has served for the diagnosis of parasitic, [162][163][164][165][166] viral, [167][168][169][170] and fungal 171,172 diseases, tuberculosis, 173 melioidosis, 174 syphilis, 175 brucellosis, 176 shigellosis, 177 E. coli infections, 178 salmonellosis, 179 and early pregnancy; 180 blood group determination; 181 dot-blot hybridization; 182 detection of antibiotics; 183 diagnosis of myocardial infarction 184 and hepatitis B; 185 and other purposes.…”

Mixed Stimuli-Responsive Magnetic and Gold Nanoparticle System for Rapid Purification, Enrichment, and Detection of Biomarkers

“…This system was useful for purification and concentration, but additional steps of biomarker release and gold labeling for optimized visual detection would be required in lateral flow or flow-through tests. AuNPs have a long history as optical labels in immunoassay and biodetection (6)(7)(8)(9)(10)(11)(12)(13) due to their large extinction coefficients (>10 9 M -1 cm -1 ) in the visible range and enhanced electric near-fields at the particle surface. While one potential solution to simplifying this system would be to use a stimuli-responsive core-shell Au/ mNP system (14)(15)(16)(17)(18)(19), we present here the finding that mixed stimuli-responsive AuNPs and mNPs coaggregate efficiently.…”