scholarly journals Seroprevalence of the enteroaggregative Escherichia coli virulence factor dispersin among USA travellers to Cuernavaca, Mexico: a pilot study

2008 ◽  
Vol 57 (4) ◽  
pp. 476-479 ◽  
Author(s):  
David B. Huang ◽  
Eric L. Brown ◽  
Herbert L. DuPont ◽  
Jing Cerf ◽  
Lily Carlin ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pilot Study ◽  
Virulence Factor ◽  
Time Of Arrival ◽  
Serum Samples ◽  
Igg Antibody ◽  
Asymptomatic Group ◽  
Immunological Responses ◽  
The Mean ◽  
Paired Serum

This pilot study examined the change in the seroprevalence of the enteroaggregative Escherichia coli (EAEC) virulence factor dispersin in USA students during a short stay in Cuernavaca, Mexico, between June and August 2004. One hundred and ninety-five students provided paired serum samples – one on arrival to Mexico (pre-serum) and a second on departure from Mexico (post-serum) after a mean stay of 19 days. Serum samples were tested for IgG antibody to a recombinant purified dispersin protein by ELISA. For all travellers, with and without diarrhoea, the mean±sd pre-serum absorbance value (read at 450 and 570 nm) was 0.340±0.212 and the mean post-serum value was 0.513±0.316 (P<0.00001). Both travellers who developed diarrhoea and those who did not develop diarrhoea had an increase in IgG antibody to dispersin from the time of arrival to the time of departure from Cuernavaca (diarrhoea group 0.323±0.197 to 0.501±0.311, P<0.00001, and the asymptomatic group 0.354±0.224 to 0.525±0.321, P<0.00001). The pre-serum absorbance value (read at 450 and 570 nm) for IgG antibody to dispersin was not associated with protection against the development of diarrhoeal illness. These results indicate that USA travellers to Mexico show seroconversion for the EAEC virulence factor dispersin. Further studies are needed to characterize in more detail the host clinical and immunological responses to the dispersin protein.

scholarly journals Detection of antibodies to recombinant truncated flagellin and sonicated whole cell antigen of Burkholderia pseudomallei in acute melioidosis and in healthy Bangladeshi individuals

2020 ◽  
Vol 14 (1) ◽  
pp. 47-52
Author(s):  
Md Shariful Alam Jilani ◽  
Tang Thean Hock ◽  
Sraboni Mazumder ◽  
Fahmida Rahman ◽  
Md Mohiuddin ◽  
...  
Keyword(s):  
Rural Areas ◽  
Burkholderia Pseudomallei ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Healthy Individuals ◽  
Serum Samples ◽  
Igg Antibody ◽  
Whole Cell ◽  
Cell Antigen ◽  
The Mean

Background and objectives: Several types of Burkholderia pseudomallei antigens have been used to determine the antibody response in acute and asymptomatic cases. In the present study, we have detected immunoglobulin G (IgG) antibody to recombinant truncated flagellin antigen (RTFA) of B. pseudomallei in the sera of acute melioidosis cases and healthy individuals from melioidosis endemic areas of Bangladesh by indirect enzyme-linked immunosorbent assay (ELISA). In parallel, IgG antibody to sonicated whole cell antigen (SWCA) of B. pseudomallei was determined to compare with anti-RTFA antibody. Methodology: Serum samples from culture confirmed melioidosis cases and from healthy individuals aged 21 years and above residing in melioidosis endemic rural areas were included in the study. Serum IgG antibody to RTFA and SWCA of B. pseudomallei was determined by indirect ELISA. Results: Out of 8 culture confirmed acute melioidosis cases, 7 (87.5%) and 8 (100%) were positive for anti-B. pseudomallei IgG antibodies by RTFA and SWCA methods respectively. Among 361 healthy individuals, the rate of seropositivity by RTFA-ELISA was significantly less than that of SWCA-ELISA (16.1% versus 26.8%; p = 0.001). The mean optical density (OD) of RTFA-ELISA of positive cases was significantly less than that of SWCA-ELISA in both melioidosis and healthy individuals (0.79±0.11 versus 2.4±0.08, p = 0.0001; 0.67±0.01 versus 1.27±0.02, p = 0.0001). The sensitivity and specificity of RTFA-ELISA were 88.9% and 100% respectively. Conclusion: Findings of the study suggest that multiple or combination of antigens should be used to study the seroprevalence of B. pseudomallei infection in a community. Also, prospective study is necessary to find out the duration of persistence of antibodies to different antigenic components of B. pseudomallei after exposure. Ibrahim Med. Coll. J. 2020; 14(1): 47-52

Otitis Media in the Young Infant: An IgE-Mediated Disease?

1980 ◽  
Vol 89 (3_suppl) ◽  
pp. 133-137 ◽  
Author(s):  
John L. Sloyer ◽  
John H. Ploussard ◽  
Laurel J. Karr
Keyword(s):  
Otitis Media ◽  
Otitis Media With Effusion ◽  
Skin Testing ◽  
Young Infant ◽  
Specific Ige ◽  
Serum Samples ◽  
Igg Antibody ◽  
Total Ige ◽  
Ige Antibody ◽  
The Mean

IgE antibody directed against noncapsular antigens of mechanically disrupted Streptococcus pneumoniae, serotype 3 rough, was demonstrated in middle ear effusions (MEE) and serum of infants with and without prior evidence of pneumococcal otitis media with effusion (OME). The techniques employed included radioimmunoassay (RIA), passive skin testing, Prausnitz-Küstner (P/K), and enzyme-linked immunospecific assay (ELISA). Adsorption of MEE with ultrasonically disrupted crude pneumococcal antigen (CPA-U) resulted in a reduction of total IgE counts per minute and suggested bacteria-specific IgE antibody ranging from approximately 22 to 92% of the total IgE. The biological activity of the IgE antibody was confirmed by challenging skin passively sensitized with MEE IgE and CPA-U. Areas of induration appeared 20 minutes after challenge and continued to increase in size until 90 minutes. An ELISA procedure was developed as a tool to determine the nature of the antigen(s) and to determine the class(es) of antibody other than IgE. It appeared that CPA-U possesses free amino groups and that it can withstand the rigors of autoclaving. An analysis of 45 cord bloods revealed that high levels of IgG CPA-U antibody occur in this type of sample and that no correlation exists between the IgE and IgG levels. The mean IgG: IgE ratio, optical density at 420 nm (OD 420), for cord bloods was 2.49. In contrast, serum samples from nine infants without pneumococcal otitis media and from 14 infants with pneumococcal otitis media had lower levels of IgG antibody. There was no significant relationship between IgG and IgE OD 420 in infants who never had an episode of pneumococcal otitis media and the mean IgG: IgE was 1.88, whereas the ratio for those infants with pneumococcal otitis media was 1.56. In addition, there was a significant correlation between IgG and IgE levels in this latter group. The results suggest that it may be important to monitor the levels of at least these two classes of antibody to enhance our understanding of the pathogenesis and recovery from otitis media.

scholarly journals The use of dried blood spots for the serological evaluation of SARS-CoV-2 antibodies

2021 ◽  
Author(s):  
Zheng Quan Toh ◽  
Rachel A Higgins ◽  
Jeremy Anderson ◽  
Nadia Mazarakis ◽  
Lien Anh Ha Do ◽  
...  
Keyword(s):  
Dried Blood Spots ◽  
Strongly Correlated ◽  
Serum Samples ◽  
Igg Antibody ◽  
Seropositivity Rate ◽  
Hard To Reach Populations ◽  
Specific Igg ◽  
Polymerase Chain ◽  
Paired Serum ◽  
Serum Igg Levels

Abstract Background To determine if dried blood spot specimens (DBS) can reliably detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies, we compared the SARS-CoV-2 IgG antibody response in paired serum and eluates from DBS specimens. Methods A total of 95 paired DBS and serum samples were collected from 74 participants (aged 1–63 years) as part of a household cohort study in Melbourne, Australia. SARS-CoV-2 IgG antibodies specific for the receptor-binding domain (RBD) and S1 proteins between serum and eluates from DBS specimens were compared using an FDA-approved ELISA method. Results Among the 74 participants, 42% (31/74) were children and the rest were adults. A total of 16 children and 13 adults were SARS-CoV-2 positive by polymerase chain reaction. The IgG seropositivity rate was similar between serum and DBS specimens (18.9% (18/95) versus 16.8% (16/95)), respectively. Similar RBD and S1-specific IgG levels were detected between serum and DBS specimens. Serum IgG levels strongly correlated with DBS IgG levels (r = 0.99, P &lt; 0.0001) for both SARS-CoV-2 proteins. Furthermore, antibodies remained stable in DBS specimens for &gt;3 months. Conclusions DBS specimens can be reliably used as an alternative to serum samples for SARS-CoV-2 antibody measurement. The use of DBS specimens would facilitate serosurveillance efforts particularly in hard-to-reach populations and inform public health responses including COVID-19 vaccination strategies.

scholarly journals SARS-CoV-2 IgG antibody responses in rt-PCR positive cases: first report from India

2020 ◽  
Author(s):  
Girish Chandra Dash ◽  
Debaprasad Parai ◽  
Hari Ram Choudhary ◽  
Annalisha Peter ◽  
Usha Kiran Rout ◽  
...  
Keyword(s):  
Antibody Response ◽  
Infected Individual ◽  
Antibody Responses ◽  
Rt Pcr ◽  
Serum Samples ◽  
Igg Antibody ◽  
Ct Value ◽  
Significant Difference ◽  
The Mean ◽  
The Relationship

AbstractThe SARS-CoV-2 antibody responses remain poorly understood and the clinical utility of serological testing is still unclear. As it is thought to confer some degree of immunity, this study is carried out to know the relationship between demographics and ct value of confirmed rt-PCR patients. A total of 384 serum samples were collected between 4-6 weeks after confirmed SARS-CoV-2 infection. IgG positivity was found to be 80.2% (95% CI, 76.2 – 84.2). The IgG positivity increased with the decrease in the ct value, with highest of 87.6% positivity in individuals with <20 ct value. The mean (± SD) ct value of IgG positives and og IgG negatives was 23.34 (± 6.09) and 26.72 (± 7.031) respectively. There was no significant difference found between the demographic characteristics such as age, sex, symptoms and antibody response. The current study is first of its kind wherein we have assessed the correlation of ct of RT-PCR with development of IgG against SARS-CoV-2. Our study showed that although Ct value might not have any relation with severity of the diseases but is associated with the antibody response among the SARS-CoV-2 infected individual.

scholarly journals The serum and conjunctival antibody response to trachoma in Gambian children

1972 ◽  
Vol 70 (4) ◽  
pp. 727-740 ◽  
Author(s):  
L. H. Collier ◽  
J. Sowa ◽  
Shiona Sowa
Keyword(s):  
Indirect Immunofluorescence ◽  
Serum Antibody ◽  
Immunofluorescence Method ◽  
Serum Samples ◽  
Igg Antibody ◽  
Follicular Hyperplasia ◽  
Iga Antibodies ◽  
Iga Antibody ◽  
The Mean ◽  
Almost All

SUMMARYNinety-nine young Gambian children were studied for 61 weeks. About half of them had trachoma at the outset, and 80 % of the remainder acquired the disease while under observation. IgG trachoma antibody in the serum and IgG and IgA antibodies in the conjunctival secretions (CS) were titrated by an indirect immunofluorescence method. In serum samples obtained in capillary tubes the mean titre was slightly higher than in samples collected on filter paper. Sorum antibody at titres ↛ 1/10 was invariably associated with a clinical diagnosis of trachoma; it increased both in frequency and titre as the disease progressed, and was present in about half of those with Tr II. In CS, IgG antibody was present less often and at lower titres than in serum, and IgA antibody was detected even less frequently. There was some evidence of correlation between the titres of IgG and IgA antibodies in CS, but none for a relationship between the titres of the antibodies in serum and those in CS. Antibodies were almost never present in the absence of conjunctival follicles, but their titres were unrelated to the degree of follicular hyperplasia; there was no obvious relationship between the serological findings and corneal lesions. In children diagnosed clinically as trachoma, serum antibody was present in almost all those with conjunctival inclusions, and in a proportion of inclusion-negative subjects; the mean titre was much higher in the inclusion-positive group.These findings do not settle whether CS antibodies are made locally, or are derived partly or wholly from the blood. They suggest that the indirect immunofluorescence test may be a useful diagnostic aid in trachoma, particularly in view of the rarity of false positive reactions; but there is at present little to choose between it and complement-fixation tests in terms of sensitivity.

scholarly journals SARS-CoV-2 IgG antibody responses in rt-PCR-positive cases: first report from India

2021 ◽  
Vol 3 (10) ◽  
Author(s):  
Girish Chandra Dash ◽  
Debaprasad Parai ◽  
Hari Ram Choudhary ◽  
Annalisha Peter ◽  
Usha Kiran Rout ◽  
...  
Keyword(s):  
Antibody Response ◽  
Clinical Utility ◽  
Antibody Responses ◽  
Serological Testing ◽  
Rt Pcr ◽  
Serum Samples ◽  
Igg Antibody ◽  
Significant Difference ◽  
The Mean ◽  
The Relationship

Introduction. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody responses remain poorly understood and the clinical utility of serological testing is still unclear. Aim. To understand the relationship between the antibody response to SARS-CoV-2 infection and the demographics and cycle threshold (C t) values of confirmed RT-PCR patients. Methodology. A total of 384 serum samples were collected from individuals between 4–6 weeks after confirmed SARS-CoV-2 infection and tested for the development of immunoglobulin class G (IgG) against SARS-CoV-2. The C t values, age, gender and symptoms of the patients were correlated with the development of antibodies. Results. IgG positivity was found to be 80.2 % (95 % CI, 76.2–84.2). Positivity increased with a decrease in the C t value, with the highest (87.6 %) positivity observed in individuals with C t values <20. The mean (±sd) C t values for IgG positives and negatives were 23.34 (±6.09) and 26.72 (±7.031), respectively. No significant difference was found for demographic characteristics such as age and sex and symptoms and antibody response. The current study is the first of its kind wherein we have assessed the correlation of the RT-PCR C t with the development of IgG against SARS-CoV-2. Conclusion. Although C t values might not have any relation with the development of symptoms, they are associated with the antibody response among SARS-CoV-2-infected individuals.

scholarly journals Anti-Leishmania infantum IgG Antibody Avidity in Visceral Leishmaniasis

2013 ◽  
Vol 20 (11) ◽  
pp. 1697-1702 ◽  
Author(s):  
Monique Gomes Salles Tiburcio ◽  
Laís Anversa ◽  
Kelly Aparecida Kanunfre ◽  
Antonio Walter Ferreira ◽  
Virmondes Rodrigues Júnior ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
High Avidity ◽  
Chronic Infections ◽  
Serum Samples ◽  
Igg Antibody ◽  
Asymptomatic Group ◽  
Content Type ◽  
Igg Avidity ◽  
History Of ◽  
Asymptomatic Subjects

ABSTRACTIgG avidity tests are used to discriminate acute from chronic infections. There are few reports on the IgG avidity profile of patients with visceral leishmaniasis (VL). This study investigated the anti-LeishmaniaIgG avidity in patients with classic VL (n= 10), patients showing clinical cure after treatment (n= 18), and asymptomatic subjects with at least one positiveLeishmaniatest (n= 20). All subjects were from areas in Brazil where VL is endemic. Serum samples were collected from each subject on two different occasions. IgG avidity was evaluated by Western blotting. The proportion of high-avidity antibodies was higher in all samples from patients with classic VL. In contrast, low-avidity antibodies predominated in subjects with a history of VL, including 13 cases (72.2%) in the first assessment and 14 (77.8%) in the second. Fifteen (75%) of the asymptomatic subjects presented a predominance of low-avidity antibodies in the first assessment, and the frequency of high-avidity antibodies increased over time in seven subjects (35%) of this group. Antibodies against the 14- and/or 16-kDa antigen fraction were detected in the first assessment in all patients with classic VL, in 10 (55.5%) treated patients, and in 10 (50%) asymptomatic subjects. These were high-avidity antibodies in most cases. In the asymptomatic group, an increase in IgG avidity against the 14- and/or 16-kDa antigen fraction was observed in three cases (15%). The results indicate distinct responses in infected and asymptomatic subjects, probably associated with the length of time after infection. In this respect, IgG avidity tests represent a new approach to better characterize asymptomatic VL.

Immunologic Assessment of Patients Treated with Bovine Fibrin as a Hemostatic Agent

1996 ◽  
Vol 76 (06) ◽  
pp. 0925-0931 ◽  
Author(s):  
John F Carroll ◽  
Keith A Moskowitz ◽  
Niloo M Edwards ◽  
Thomas J Hickey ◽  
Eric A Rose ◽  
...  
Keyword(s):  
Coagulation Factors ◽  
Allergic Reactions ◽  
Factor V ◽  
Normal Range ◽  
Serum Samples ◽  
Human Fibrinogen ◽  
Bovine Thrombin ◽  
Thrombotic Complications ◽  
The Mean ◽  
Clinically Significant

SummaryTwenty-one cardiothoracic surgical patients have been treated with fibrin as a topical hemostatic/sealing agent, prepared from bovine fibrinogen clotted with bovine thrombin. Serum samples have been collected before treatment with fibrin and postoperatively between 1 and 9 days, 3 and 12 weeks, and 6 and 8 months. The titers of anti-bovine fibrinogen antibodies, measured by ELISA specific for immunoglobulins IgG or IgM, increased to maximal values after about 8 or 6 weeks, respectively. After 8 months, IgG titers were on average 20-fold lower than the mean maximal value, while IgM titers returned to the normal range. IgG was the predominant anti-bovine fibrinogen immunoglobulin as documented by ELISA, affinity chromatography and electrophoresis. Anti-bovine fibrinogen antibodies present in patients reacted readily with bovine fibrinogen, but did not cross-react with human fibrinogen as measured by ELISA or by immunoelectrophoresis. A significant amount of antibodies against bovine thrombin and factor V has been found, many cross-reacting with the human counterparts. No hemorrhagic or thrombotic complications, or clinically significant allergic reactions, occurred in any patient, in spite of antibody presence against some bovine and human coagulation factors. The treatment of patients with bovine fibrin, without induction of immunologic response against human fibrinogen, appeared to be an effective topical hemostatic/sealing measure.

Autoantibodies to Thrombomodulin: Development of an Enzyme Immunoassay and a Survey of their Frequency in Patients with the Lupus Anticoagulant

1992 ◽  
Vol 67 (05) ◽  
pp. 507-509 ◽  
Author(s):  
John Gibson ◽  
Margaret Nelson ◽  
Ross Brown ◽  
Hatem Salem ◽  
Harry Kronenberg
Keyword(s):  
Enzyme Immunoassay ◽  
Lupus Anticoagulant ◽  
Specific Binding ◽  
Technical Problem ◽  
Serum Samples ◽  
Citrate Buffer ◽  
The Mean ◽  
Sample Dilution ◽  
Negative Population ◽  
Serum Components

SummaryIn order to investigate the possibility that autoantibodies to thrombomodulin (TM) may exist in patients with the lupus anticoagulant (LA) and perhaps be implicated in the pathogenesis of recurrent thrombosis seen in such patients, we developed an enzyme-immunoassay to screen serum samples for anti-human TM activity. The major technical problem encountered in developing this assay was to reduce the non-specific binding of serum components from both the LA positive and the negative population. Considerable reduction of non-specific binding was achieved by use of a phosphate/citrate buffer at pH 8.0 and the use of an optimal sample dilution of 1/40. In addition, samples were always tested in parallel in blank wells and results are expressed as an OD ratio. Samples from 113 patients with the LA were assayed and compared to 78 patients referred for LA testing but found to be negative. The mean OD values for the LA positive patients (± SD) was 1.36 (0.44) with a range of 0.78-2.57. This was virtually identical to the values for the LA negative population (1.38 ± 0.40, range 0.76-2.77). The results of this study indicate that there is no evidence for the presence of a significant autoantibody activity to TM in patients with the LA when compared to LA negative patients. If such autoantibodies do exist their frequency must be quite low.

The Safety and Antimicrobial Properties of Stabilized Hypochlorous Acid in Acetic Acid Buffer for the Treatment of Acute Wounds—a Human Pilot Study and In Vitro Data

2021 ◽  
pp. 153473462110156
Author(s):  
Ewa A. Burian ◽  
Lubna Sabah ◽  
Klaus Kirketerp-Møller ◽  
Elin Ibstedt ◽  
Magnus M. Fazli ◽  
...  
Keyword(s):  
Pilot Study ◽  
Hypochlorous Acid ◽  
Treatment Time ◽  
Donor Site ◽  
Antimicrobial Properties ◽  
Prolonged Treatment ◽  
Wound Irrigation ◽  
The Mean ◽  
And Performance

Acute wounds may require cleansing to reduce the risk of infection. Stabilized hypochlorous acid in acetic buffer (HOCl + buffer) is a novel wound irrigation solution with antimicrobial properties. We performed a first-in-man, prospective, open-label pilot study to document preliminary safety and performance in the treatment of acute wounds. The study enrolled 12 subjects scheduled for a split-skin graft transplantation, where the donor site was used as a model of an acute wound. The treatment time was 75 s, given on 6 occasions. A total of 7 adverse events were regarded as related to the treatment; all registered as pain during the procedure for 2 subjects. One subject had a wound infection at the donor site. The mean colony-forming unit (CFU) decreased by 41% after the treatment, and the mean epithelialization was 96% on both days 14 (standard deviation [SD] 8%) and 21 (SD 10%). The study provides preliminary support for the safety, well-tolerance, and efficacy of HOCl + buffer for acute wounds. The pain was frequent although resolved quickly. Excellent wound healing and satisfying antimicrobial properties were observed. A subsequent in vitro biofilm study also indicated good antimicrobial activity against Pseudomonas aeruginosa with a 96% mean reduction of CFU, when used for a treatment duration of 15 min ( P < .0001), and a 50% decrease for Staphylococcus aureus ( P = .1010). Future larger studies are needed to evaluate the safety and performance of HOCl + buffer in acute wounds, including the promising antimicrobial effect by prolonged treatment on bacterial biofilms.

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