scholarly journals Development of a Novel Rapid Immunodiagnostic Kit Based on Flagellar 40 kDa Antigen Epitope for the Detection of Typhoid Fever in Indian Patients

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Rahul Mitra ◽  
Surya Bhan ◽  
Gopal Nath ◽  
Narender Kumar ◽  
Ziledar Ali
Keyword(s):  
Staphylococcus Aureus ◽  
Typhoid Fever ◽  
Direct Detection ◽  
Febrile Illness ◽  
Cross Reactivity ◽  
Negative Results ◽  
Kala Azar ◽  
Primary Health Centres ◽  
Test Kit ◽  
Specific Igg

To aid the clinical diagnosis of typhoid fever in India, where most hospitals and primary health centres have no facilities for culture, we report on the development of a novel and rapid immunodiagnostic kit for the direct detection ofSalmonellaTyphi—specific IgG antibodies againstS. Typhi flagellar H antigen. The disease often does not show a specific clinical picture, and can be confused with other febrile illness such as malaria, dengue fever andStaphylococcus aureus. To overcome the problem of cross reactivity specific epitope of the flagellar H antigen was immobilised on the testing kit strip eliminating chances of cross reactivity and false positive results thereby increasing the specificity of the test. Since the immunodiagnostic kit, uses the flagellar H antigen from bacteria present in our country, the antibodies present in the serum of patients of our country will have maximum binding affinity, enhancing the sensitivity of our test kit. The immunodiagnostic kit on analysis gave a positive result with clinically diagnosed typhoid positive patient serum and negative results were obtained with the sera of clinically diagnosed malaria, abscess ofStaphylococcus aureusand Visceral leishmaniasis (Kala-azar) patients.

Using Clinical Profiles and Complete Blood Counts to Differentiate Causes of Acute Febrile Illness during the 2009–11 Outbreak of Typhoid and Chikungunya in a Dengue Endemic Area

2020 ◽  
Vol 66 (5) ◽  
pp. 504-510
Author(s):  
Kamolwish Laoprasopwattana ◽  
Wannee Limpitikul ◽  
Alan Geater
Keyword(s):  
Typhoid Fever ◽  
Predictive Value ◽  
Nonstructural Protein ◽  
Specific Treatment ◽  
Febrile Illness ◽  
Acute Febrile Illness ◽  
Negative Results ◽  
Nonstructural Protein 1 ◽  
Clinical Profiles ◽  
Complete Blood Counts

Abstract Background and aims After the 2009–11 outbreak of typhoid and chikungunya (CHIK) in Thailand, an effort was made to use complete blood counts and clinical profiles to differentiate these diseases to facilitate earlier specific treatment. Methods Patients aged 2–15 years having fever on first visit ≤3 days without localizing signs were enrolled retrospectively. Typhoid fever was confirmed by hemoculture, dengue by nonstructural protein-1 or polymerase chain reaction (PCR), and CHIK by PCR. Febrile children with negative results for these infections were classified as other acute febrile illness (AFI). Results Of the 264 cases, 56, 164, 25 and 19 had typhoid fever, dengue viral infection (DVI), CHIK and other AFI, respectively. Arthralgia had sensitivity, specificity, positive predictive value (PPV) and negative predictive value of 0.96, 0.97, 0.80 and 0.99, respectively, to differentiate CHIK from the others. After excluding CHIK by arthralgia, the PPV of the WHO 1997 and 2009 criteria for DVI increased from 0.65 and 0.73 to 0.95 and 0.84, respectively. Children with one of myalgia, headache or leukopenia had sensitivity of 0.84, specificity of 0.76 and PPV of 0.92 to differentiate DVI from typhoid and other AFIs. Patients with one of abdominal pain, diarrhea or body temperature >39.5°C were more likely to have typhoid fever than another AFI with PPV of 0.90. Conclusion Using this flow chart can help direct physicians to perform more specific tests to confirm the diagnosis and provide more specific treatment. Nevertheless, clinical follow-up is the most important tool in unknown causes of febrile illness.

scholarly journals Development and Evaluation of a Sensitive Bacteriophage-Based MRSA Diagnostic Screen

Viruses ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 631
Author(s):  
Matthew Brown ◽  
Wendy Hahn ◽  
Bryant Bailey ◽  
Alex Hall ◽  
Gema Rodriguez ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Low Cost ◽  
Cross Reactivity ◽  
Luciferase Reporter ◽  
Bacillus Species ◽  
Beta Lactam ◽  
Negative Results ◽  
Supportive Role ◽  
Lactam Antibiotic

Engineered luciferase reporter bacteriophages provide specific, sensitive, rapid and low-cost detection of target bacteria and address growing diagnostic needs in multiple industries. Detection of methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization and antibiotic susceptibility play a critical supportive role in preventing hospital-acquired infections and facilitating antibiotic stewardship. We describe the development and evaluation of a novel phage-based MRSA diagnostic screen for nasal swab specimens. The screen utilizes two luciferase reporter phages capable of recognizing genetically-diverse Staphylococcus aureus. The beta-lactam antibiotic cefoxitin is included to differentiate between resistant (MRSA) and susceptible organisms. The screen positively identified 97.7% of 390 clinical MRSA isolates at low bacterial concentrations. At higher inoculums, 93.5% of 123 clinical non-MRSA Staphylococcus aureus yielded appropriate negative results. Although cross-reactivity of the phage cocktail was observed with other staphylococcal and bacillus species, these false positives were absent under selective conditions. MRSA remained detectable in the presence of 38 distinct competing species and was accurately identified in 100% of 40 spiked nasal specimens. Thus, this six-hour screen sensitively detected MRSA both in vitro and in human nasal matrix.

scholarly journals How Do Preoperative Antibiotics Affect Culture Yield in Diabetic Foot Infections?

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Heather Young ◽  
Whitney Miller ◽  
Randy Burnham ◽  
Susan Heard ◽  
Chrystal Berg ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Diabetic Foot ◽  
Gram Negative ◽  
Diabetic Foot Infection ◽  
Negative Results ◽  
Diabetic Foot Infections ◽  
Preoperative Antibiotics ◽  
The Impact ◽  
Culture Negative ◽  
Culture Yield

abstractThe impact of preoperative antibiotics on culture of diabetic foot infection samples has not been studied. We found that increasing exposure to preoperative antibiotics was associated with less frequent growth of streptococci and anaerobes and more culture-negative results. In contrast, the yield of Staphylococcus aureus and Gram-negative bacilli was unaffected.

scholarly journals Antibodies produced by dogs successfully challenged with live Leptospira spp. did not cross-react to Brucella antigen in a commercial rapid slide agglutination test that detects antibodies to Brucella canis

2018 ◽  
Vol 31 (1) ◽  
pp. 83-85
Author(s):  
Matthew R. Krecic
Keyword(s):  
Cross Reactivity ◽  
Agglutination Test ◽  
Slide Agglutination ◽  
Serologic Tests ◽  
Experimental Infections ◽  
Negative Results ◽  
Brucella Canis ◽  
Slide Agglutination Test ◽  
Leptospira Spp ◽  
Canine Brucellosis

Brucella canis is a cause of canine infertility and abortion. Veterinarians and veterinary laboratorians screen for antibodies to B. canis with serologic tests including a rapid slide agglutination test (RSAT; D-Tec CB, Zoetis, San Diego, CA). False-positive results are possible because of cross-reactivity to antibodies to some gram-negative bacteria. Cross-reactivity has been reported between antibodies of Brucella abortus and Leptospira spp. with serologic tests for bovine brucellosis; however, this has not been documented with serologic tests for canine brucellosis, to the author’s knowledge. The RSAT was evaluated with the sera from dogs experimentally challenged with 1 of 4 serovars of Leptospira spp.: L. kirschneri serovar Grippotyphosa, or L. interrogans serovars Canicola, Icterohaemorrhagiae, or Pomona. Experimental infections were confirmed through results of microscopic agglutination testing and/or lateral flow immunochromatography testing. The sera of 32 dogs collected at day 0 and days 7, 10, and 14 yielded negative results with the RSAT. Antibodies produced through experimental infections to these 4 serovars of Leptospira spp. did not cross-react with Brucella antigen with the RSAT; therefore, cross-reactivity of anti-leptospiral antibodies may not be of concern for B. canis rapid slide agglutination testing of dogs.

scholarly journals Ceftaroline Desensitization Procedure in a Pregnant Patient With Multiple Drug Allergies

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
James L. Kuhlen ◽  
Kimberly G. Blumenthal ◽  
Caroline L. Sokol ◽  
Diana S. Balekian ◽  
Ana A. Weil ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Skin Testing ◽  
Pregnant Patient ◽  
Cross Reactivity ◽  
Multiple Drug ◽  
Methicillin Resistant ◽  
The Cross ◽  
Staphylococcus Aureus Pneumonia

Abstract Validated skin testing is lacking for many drugs, including ceftaroline. The cross-reactivity between ceftaroline and other β-lactam antibiotics is unknown. We report a case of a pregnant patient with cystic fibrosis and multiple drug allergies who required ceftaroline for methicillin-resistant Staphylococcus aureus pneumonia and underwent an uncomplicated empiric desensitization procedure.

Fluorescent antibody techniques have allowed for the direct identification and enumeration of individual bacteria in environmental samples without requiring prior growth in culture media (Bahlool and Schmidt 1980, Cloete and Steyn 1988, Macario et al. 1989). The technique involves the use of specific antibodies raised against surface markers of defined pure cultures that are either labelled directly with fluorescent dye molecules or via a fluorescent secondary antibody. This approach has yielded important insights into the spatial distribution of microorganisms, but it suffers from a number of disadvantages. For example, expression of the antigen may be influenced by environmental factors; false-positive and false-negative results may be obtained due to cross-reactivity or lack of reaction; non-specific binding of antibodies may result in high levels of background fluorescence; and production of specific antibodies requires a pure culture of the organism of interest (Cloete and de Bruyn Various recombinant DNA techniques have subsequently been developed that are independent of cultivation methods (Fig. 1). These techniques provide ways of detecting and quantifying specific phylogenetic groups of microbes on 16S rDNA sequences, and relevant structural genes provide ways of monitoring microbial populations of environmental and industrial systems. In addition to these tools, a number of emerging technologies such as the use of biomarker genes are being increasingly used to monitor with great precision and accuracy the behaviour of microbes in the environment.

2003 ◽  
pp. 218-219
Keyword(s):  
Recombinant Dna ◽  
Culture Media ◽  
Specific Binding ◽  
Fluorescent Antibody ◽  
False Negative ◽  
Cross Reactivity ◽  
Phylogenetic Groups ◽  
Specific Antibodies ◽  
Negative Results ◽  
Recombinant Dna Techniques

scholarly journals MODERN APPROACHES TO ANTIVIRULENT THERAPY OF DISEASES ASSOCIATED WITH STAPHYLOCOCCUS AUREUS

2019 ◽  
Vol 23 (3-4) ◽  
pp. 26-31
Author(s):  
T.O. Kryuchko ◽  
O.Ya. Tkachenko ◽  
N.V. Kuzmenko ◽  
I.N. Nesina ◽  
S.M. Tanianska ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Virulence Factors ◽  
Bacterial Infections ◽  
Effective Means ◽  
Bacterial Pathogen ◽  
Cross Reactivity ◽  
Main Function ◽  
Virulence Proteins ◽  
New Antibiotics ◽  
Active Research

Staphylococcus aureus is a universal bacterial pathogen, which is able to develop the resistance to new antibiotics, by means of virulence factors, whose main function is the spread of diseases by inhibiting the immune factors of host defense. Its wide spread at in-patient departments and also the presence of clinical probationary wards Staphylococcus aureus, resistant to methicillin at out-patient departments, deprive the doctors of effective means for control of the infection. Complications caused by MRSA lead to hospitalization and indices of lethality. The aim of the paper is to analyze the main factors of S. аureus virulence and ways the of its interaction as a result of etiological and pathogenetic treatment. Complexity of treatment of bacterial infections is determined by alternative ways of prevention and treatment of diseases to which bacteria are not able to develop resistance. Along with general mechanisms that form antibiotic resistance, S. aureus produces many individual virulence factors that model the immune response, affecting the survival of the microorganism. The virulence factors produced by S. aureus are diverse and have the ability not only to cause cell lysis, but also to stimulate tissue rejection and destruction. It is important to determine that many specific factors of virulence caused by S. aureus, have ability to change both congenital and adaptive immune reactions including inhibition of complement activation, neutrophils neutralization, phagocytes inhibition. Strategies for inhibiting virulence factors can range from using small inhibitor molecules or full-fledged antibodies to creating toxoids and virulence proteins. Great interest is focused upon those inhibitors that have cross-reactivity with respect to multiple virulence factors, as well as inhibitors, the main target of which is a global regulator with multi-purpose activity, for example, agr operon. Active research into the specific alternative antivirulent treatments for severe diseases caused by S. aureus can potentially settle a number of problems and difficulties of post-antibiotic era.

Interpretation and Utility of Drug of Abuse Immunoassays: Lessons From Laboratory Drug Testing Surveys

2010 ◽  
Vol 134 (5) ◽  
pp. 735-739 ◽  
Author(s):  
Stacy E. F. Melanson ◽  
Leland Baskin ◽  
Barbarajean Magnani ◽  
Tai C. Kwong ◽  
Annabel Dizon ◽  
...  
Keyword(s):  
Drug Testing ◽  
Drugs Of Abuse ◽  
False Negative ◽  
Cross Reactivity ◽  
Treatment Programs ◽  
Drug Of Abuse ◽  
Negative Results ◽  
Urine Drug ◽  
Clinically Significant ◽  
Pain Services

Abstract Context.—To assist with patient diagnosis and management, physicians from pain services, drug treatment programs, and the emergency department frequently request that urine be tested for drugs of abuse. However, urine immunoassays for drugs of abuse have limitations. Objective.—To use data from the College of American Pathologists Proficiency Testing Surveys to determine and summarize the characteristics, performance, and limitations of urine immunoassays for drugs of abuse. Design.—Six years of urine drug testing proficiency surveys were reviewed. Results.—Lysergic acid diethylamide and methaqualone are infrequently prescribed or abused and, therefore, testing may be unnecessary. However, implementation of more specific testing for methylenedioxymethamphetamine and oxycodone may be warranted. Each drug of abuse immunoassay exhibits a different cross-reactivity profile. Depending on the cross-reactivity profile, patients with clinically insignificant concentrations of drugs may have false-positive results, and patients with clinically significant concentrations of drugs may have false-negative results. Conclusions.—Laboratory directors should be aware of the characteristics of their laboratories' assays and should communicate these characteristics to physicians so that qualitative results can be interpreted more accurately. Furthermore, manufacturer's claims should be interpreted with caution and should be verified in each organization's patient population, if possible.

scholarly journals Validation of the Reveal® 3-D for Peanut Lateral Flow Test: AOAC Performance Tested MethodSM 111901

2020 ◽  
Vol 103 (4) ◽  
pp. 1112-1118
Author(s):  
Quynh-Nhi Le ◽  
Alexis Vance ◽  
Nawal Bakir ◽  
Dave Almy ◽  
Emily Slenk ◽  
...  
Keyword(s):  
Cross Reactivity ◽  
Management Program ◽  
Lateral Flow ◽  
Ammonium Compound ◽  
Flow Test ◽  
Test Kit ◽  
Low Levels ◽  
Lateral Flow Test ◽  
Food Commodities ◽  
Assay Interference

Abstract Background Reveal® 3-D for Peanut is an immunochromatographic, lateral flow test for qualitative detection of peanut residue in food manufacturing and food preparation settings. The test can detect low ppm levels of peanut in clean-in-place (CIP) rinses and in swabs from environmental surfaces and can serve as a tool in managing allergen risk. Objective The objective of the study was to validate the lateral flow method for detection of peanut in CIP rinses, specifically water, peroxyacetic acid/hydrogen peroxide, and quaternary ammonium compound rinses, and in swabs taken from stainless steel and plastic surfaces. Methods CIP rinses spiked with low levels of peanut were tested, as were surfaces inoculated with peanut. Specificity and assay interference were assessed in testing of food commodities with and without added peanut. Assay robustness and test kit stability and consistency testing were also performed. Results Results demonstrated that the lateral flow test can detect peanut in CIP rinses in the range of 2–4 ppm and in environmental surface swabs in the range of 3–4 µg/100 cm2. Results of specificity testing with 29 common food items showed lack of cross-reactivity, and potential assay interference only from walnut. Data from stability trials supports expiration dating for the kit of up to 23 months post-manufacture. Conclusions and Highlights The lateral flow test is a sensitive, specific, and rapid method for detection of low levels of peanut residue in CIP rinses and environmental samples and can be an important component in a comprehensive allergen risk management program.

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