Evaluation of serum indirect haemagglutination test results of suspected cystic echinococcosis cases from 2009-2017.

OBJECTIVE: This study aims to evaluate the serological, radiological and epidemiological analysis of suspected cystic echinococcosis patients, and to assess the positivity rate in the region. Methods: The retrospective study was conducted at Bursa Uludag University Hospital, Turkey and comprised data from January 2009 to December 2017 related to patients of either gender with suspected cystic echinococcosis who underwent indirect haemagglutination testing. Demographic and clinical data of patients who tested positive were analysed. Statistical analysis was done using SPSS 23. RESULTS: Of the 3910 patients with a mean age of 41.6±19.35 years (range: 0-93 years) who underwent indirect haemagglutination testing, 692(17.7%) tested positive; 390(56.4%) females, and 302(43.6%) males. The highest seropositivity rate 107(15.5%) was observed in 2011, followed by 104(15%) in 2016. Seropositive cases were predominantly seen in those aged 40-49 years 131 (18.9%), followed by those aged 50-59 years 124 (17.9%). CONCLUSIONS: Cystic echinococcosis was found to be a public health problem in South Marmara region of Turkey.

A rapid and affordable point of care test for antibodies against SARS-CoV-2 based on hemagglutination and artificial intelligence interpretation.

Diagnostic tests that detect antibodies (AB) against SARS-CoV-2 for evaluation of seroprevalence and guidance of health care measures are important tools for managing the COVID-19 pandemic. Current tests have certain limitations with regard to turnaround time, costs and availability, particularly in point-of-care (POC) settings. We established a hemagglutination-based AB test that is based on bi-specific proteins which contain a dromedary-derived antibody (nanobody) binding red blood cells (RBD) and a SARS-CoV-2-derived antigen, such as the receptor-binding domain of the Spike protein (Spike-RBD). While the nanobody mediates swift binding to RBC, the antigen moiety directs instantaneous, visually apparent hemagglutination in the presence of SARS-CoV-2-specific AB generated in COVID-19 patients or vaccinated individuals. Method comparison studies with assays cleared by emergency use authorization demonstrate high specificity and sensitivity. To further increase objectivity of test interpretation, we developed an image analysis tool based on digital image acquisition (via a cell phone) and a machine learning algorithm based on defined sample-training and -validation datasets. Preliminary data, including a small clinical study, provides proof of principle for test performance in a POC setting. Together, the data support the interpretation that this AB test format, which we refer to as 'NanoSpot.ai', is suitable for POC testing, can be manufactured at very low costs and, based on its generic mode of action, can likely be adapted to a variety of other pathogens.

A rapid, point-of-care red blood cell agglutination assay detecting antibodies against SARS-CoV-2.

The COVID-19 pandemic has caused significant morbidity and mortality. There is an urgent need for serological tests to detect antibodies against SARS-CoV-2, which could be used to assess past infection, evaluate responses to vaccines in development, and determine individuals who may be protected from future infection. Current serological tests developed for SARS-CoV-2 rely on traditional technologies such as enzyme-linked immunosorbent assays (ELISA) and lateral flow assays, which have not scaled to meet the demand of hundreds of millions of antibody tests so far. Herein, we present an alternative method of antibody testing that depends on one protein reagent being added to patient serum/plasma or whole blood with direct, visual readout. Two novel fusion proteins, RBD-2E8 and B6-CH1-RBD, were designed to bind red blood cells (RBCs) via a single-chain variable fragment (scFv), thereby displaying the receptor-binding domain (RBD) of SARS-CoV-2 spike protein on the surface of RBCs. Mixing mammalian-derived RBD-2E8 and B6-CH1-RBD with convalescent COVID-19 patient serum and RBCs led to visible hemagglutination, indicating the presence of antibodies against SARS-CoV-2 RBD. B6-CH1-RBD made in bacteria was not as effective in inducing agglutination, indicating better recognition of RBD epitopes from mammalian cells. Given that our hemagglutination test uses methods routinely used in hospital clinical labs across the world for blood typing, we anticipate the test can be rapidly deployed at minimal cost. We anticipate our hemagglutination assay may find extensive use in low-resource settings for detecting SARS-CoV-2 antibodies.

A haemagglutination test for rapid detection of antibodies to SARS-CoV-2.

Serological detection of antibodies to SARS-CoV-2 is essential for establishing rates of seroconversion in populations, and for seeking evidence for a level of antibody that may be protective against COVID-19 disease. Several high-performance commercial tests have been described, but these require centralised laboratory facilities that are comparatively expensive, and therefore not available universally. Red cell agglutination tests do not require special equipment, are read by eye, have short development times, low cost and can be applied at the Point of Care. Here we describe a quantitative Haemagglutination test (HAT) for the detection of antibodies to the receptor binding domain of the SARS-CoV-2 spike protein. The HAT has a sensitivity of 90% and specificity of 99% for detection of antibodies after a PCR diagnosed infection. We will supply aliquots of the test reagent sufficient for ten thousand test wells free of charge to qualified research groups anywhere in the world.

Role of a schistosoma haematobium specific microRNA as a predictive and prognostic tool for bilharzial bladder cancer in Egypt.

Urinary bladder cancer is a common malignancy in Egypt, thus reliable methodologies are required for screening and early detection. In this study, we analyzed the gene expression of a Schistosoma hematobium specific microRNA "Sha-miR-71a" and mitogen-associated protein kinase-3 (MAPK-3) in the urine samples of 50 bladder cancer patients and 50 patients with benign bilharzial cystitis. Fifty control subjects were also tested. Indirect hemagglutination test (IHA) diagnosed 70% of studied cancer cases as bilharzial associated bladder cancer (BBC), while histopathological examination detected only 18%. Urinary Sha-miR-71a & MAPK-3 revealed enhanced expression in BBC (p-value = 0.001) compared to non-bilharzial bladder cancer (NBBC) cases. Patients with chronic bilharzial cystitis exhibited a significant increase in gene expression compared to those with acute infection (p-value = 0.001). Sha-miR-71a and MAPK-3 showed good sensitivity and specificity in the diagnosis of BBC when analyzed by the receiver operating characteristic (ROC) curve. They were also prognostic regarding malignancy grade. Both biomarkers showed a positive correlation. Our results revealed that IHA is a reliable test in the diagnosis of bilharziasis associated with bladder cancer, and that Sha-miR-71a and MAPK-3 provide non-invasive specific biomarkers to diagnose BBC, as well as a potential role in testing bilharzial patients for risk to develop cancer.

Investigation of Melioidosis Using Blood Culture and Indirect Hemagglutination Assay Serology among Patients with Fever, Northern Tanzania.

Prediction models indicate that melioidosis may be common in parts of East Africa, but there are few empiric data. We evaluated the prevalence of melioidosis among patients presenting with fever to hospitals in Tanzania. Patients with fever were enrolled at two referral hospitals in Moshi, Tanzania, during 2007-2008, 2012-2014, and 2016-2019. Blood was collected from participants for aerobic culture. Bloodstream isolates were identified by conventional biochemical methods. Non-glucose-fermenting Gram-negative bacilli were further tested using a Burkholderia pseudomallei latex agglutination assay. Also, we performed B. pseudomallei indirect hemagglutination assay (IHA) serology on serum samples from participants enrolled from 2012 to 2014 and considered at high epidemiologic risk of melioidosis on the basis of admission within 30 days of rainfall. We defined confirmed melioidosis as isolation of B. pseudomallei from blood culture, probable melioidosis as a ≥ 4-fold rise in antibody titers between acute and convalescent sera, and seropositivity as a single antibody titer ≥ 40. We enrolled 3,716 participants and isolated non-enteric Gram-negative bacilli in five (2.5%) of 200 with bacteremia. As none of these five isolates was B. pseudomallei, there were no confirmed melioidosis cases. Of 323 participants tested by IHA, 142 (44.0%) were male, and the median (range) age was 27 (0-70) years. We identified two (0.6%) cases of probable melioidosis, and 57 (17.7%) were seropositive. The absence of confirmed melioidosis from 9 years of fever surveillance indicates melioidosis was not a major cause of illness.

Drug-induced immune hemolytic anemia investigation: Comparison between tube test and microcolumn agglutination (gel test) for the detection of drug-dependent antibodies in the presence of soluble drug.

OBJECTIVES: Testing for drug-dependent antibodies is traditionally performed with the tube method either with drug-treated red blood cells or with untreated red blood cells in the presence of soluble drug. Gel microcolumn agglutination method was compared to tube testing for the demonstration of drug-dependent antibodies in the presence of soluble drug. MATERIALS AND METHODS: Patient's samples were tested in parallel by tube and gel microcolumn agglutination method with untreated and/or enzyme-treated red blood cells in the presence of soluble drug. RESULTS: Twenty six different patient's samples were studied and thirty nine tests performed to investigate antibodies directed against fifteen different drugs. There was a good correlation between the results obtained by tube and gel method in terms of analytical sensitivity and specificity. Reactions appeared to be stronger with the gel test than seen with the conventional tube method for most of the drug antibodies investigated. Enzyme-treated cells should be used in addition to untreated cells to improve the sensitivity of the method for detecting drug-dependent antibodies especially those directed against drugs that do not bind firmly to red blood cells. CONCLUSIONS: Gel method appeared to be sensitive, reliable, reproducible, and comparable to the conventional tube method for the detection of all the drug-dependent antibodies investigated in this study. Further studies need to be performed to evaluate gel testing for the detection of drug-dependent antibodies that only react with drug-treated red blood cells.

Is the Second Treponemal Test Necessary in the Reverse Algorithm for the Diagnosis of Syphilis?

BACKGROUND: This study was performed to investigate the necessity of the second treponemal test and to evaluate the diagnostic performance of the first treponemal test in the reverse algorithm of syphilis diagnosis. METHODS: Abbott Architect Syphilis TP assay, a chemiluminescence immunoassay (CIA), was used as the first step treponemal test. Treponema pallidum haemagglutination assay (TPHA) test results of reactive samples from the first test were recorded. TPHA test result was considered as confirmatory. TPHA test results were grouped according to their Abbott Architect Syphilis TP assay results and they were compared with Mann-Whitney U test. For Abbott Architect Syphilis TP assay, a cutoff value with 100% specificity was determined via a ROC curve analysis which would render TPHA test unnecessary. RESULTS: Out of 146,800 samples 2,646 were reactive in the first step. Of those, 2,002 had a TPHA test result. Of the 2,002 TPHA tests, 1,706 were positive and 296 were negative. TPHA positive and negative groups have significantly different CIA signal/cutoff values. Using a ROC curve built for evaluation of the first-step test, the maximum Youden's index value was found as 5.26. If this value would be accepted as cutoff, it would have a specificity of 85%. The specificity of 100% can be reached if a new cutoff value is set to 27.83. CONCLUSIONS: Calculated cutoff value with 100% specificity is not practically applicable. It achieves saving of TPHA test in only six percent of reactive samples. Architect Syphilis TP assay is advantageous in large laboratories but is not enough to lead diagnosis without a second treponemal assay. Therefore it was decided to continue the reverse algorithm with dual treponemal assays.

Red Blood Cell Alloantibody Titration - Does the Titration Method Matter?

BACKGROUND: Red blood cell (RBC) alloantibody titration is a quasi-quantitative method to assess antibody concentration and is considered a useful means of estimating maternal alloimmunization during pregnancy. Traditionally, titration is performed using conventional tube test (CTT). The gel microcolumn agglutination-based method (GMA) has been proven reliable for many immunohematology tests. Our study compared CTT with GMA of two different, commercially available GMA systems for RBC alloantibody titration. METHODS: Serum samples with significant RBC-alloantibodies were evaluated in our study. Each sample was titrated concurrently with CTT, with ID-DiaMed-GmbH, Cressier, Switzerland (GMA1), and with DG Gel Coombs Diagnostic Grifols, Passeig Fluvial, Spain (GMA2). RESULTS: One hundred thirty-seven titration tests including 50 anti-D, 25 anti-Kell, 10 anti-E, 9 anti-Jka, 8 anti-c, 5 anti-Cw, 5 anti-Fya, 7 anti-M, 6 anti-Kpa, 3 anti-Lua, 1 anti-e, 3 anti-G, and 2 anti-Cha were performed and evaluated. Samples tested by CTT versus GMA1 and GMA2 generated mostly equal or higher titers by GMAs. The results of both comparisons were in good agreement (W = 0.91, p < 0.0001, and W = 0.92, p < 0.0001, respectively). For all antibody specificities, the mean absolute difference in titers ranged from 1 - 3 for both GMA1 and GMA2 versus CTT. Samples tested by GMA1 vs. GMA2 were in almost perfect agreement (W = 0.95, p < 0.0001). CONCLUSIONS: Although both GMAs were found slightly more sensitive than CTT for alloantibody titration, the differences were not significant and the agreement between all methods was very good, possibly indicating GMA as a suitable alternative to CTT in RBC antibody titration.

Biochemical characterization and application of a novel lectin from the cyanobacterium Lyngabya confervoides MK012409 as an antiviral and anticancer agent.

In the present study, a novel lectin was purified from the newly isolated cyanobacterium, Lyngabya confervoides MK012409 and tested for its antiviral and anticancer activity. Out of 30 isolates, Mabroka-s isolate which identified as Lyngabya confervoides MK012409 showed the highest agglutination titer. Lyngabyal lectin showed the greatest haemagglutination activity with pigeon/rabbit erythrocytes with a minimum concentration of 2.4 µg/ml. Physical characterization of Lyngabyal lectin showed ability to keep the activity at a higher temperature up to 80 °C with stability over a wide pH range (4-8) as well as its stability toward chemical denaturants. Carbohydrate specificity test revealed that the sugar alcohols completely inhibited the lectin haemagglutination activity. The electrophoretic analysis revealed that the lyngabyal lectin is a 140 kDa composed of two 70 kDa subunits. Lyngabyal lectin was able to inhibit the proliferation of MCF-7 and Caco-2 cancer cell lines with IC50 values of 246 ± 0.17 and 376.4 ± 0.34 µg/ml, respectively. Lyngabyal lectin also showed virucidal activity against HSV-1 with EC50 of 167 ± 0.52 ng/ml and inhibited plaque formation in the HSV-1 infected Vero cells with EC50 of 84.94 ± 0.34 ng/ml. These findings emphasize the ability of the lyngabyal lectin to fight breast and colon cancer besides it represents a promising antiviral agent.

A new recombinant F1 antigen as a cost and time-effective tool for plague diagnosis.

The Yersinia pestis capsular antigen F1 is widely used in plague laboratory diagnosis. Here, we describe the production of an F1 recombinant protein within reduced time and biosafety requirements. Its evaluation in hemagglutination tests indicated that the recombinant F1 can replace the conventional F1 protein for plague diagnosis.

Syphilitic chorioretinitis presenting as a choroidal granuloma.

A rare case of syphilitic uveitis presenting as a choroidal granuloma is described in this case report. The clinical picture resembled that of a tubercular choroidal granuloma. However, the patient was positive for treponemal (treponema pallidum hemagglutination assay) as well as non-treponemal tests (venereal disease research laboratory test) for syphilis. Therefore, the patient was treated for ocular syphilis and responded to antisyphilitic therapy. There was a complete resolution of the lesion at the end of 14 days of treatment.

Hemagglutination Assay for Influenza Virus.

The hemagglutination assay (HA) is a tool used to screen cell culture supernatant or amniotic-allantoic fluid harvested from embryonated chicken eggs for hemagglutinating agents, such as type A influenza. The HA is not an identification assay, as other agents also have hemagglutinating properties. Live and inactivated viruses are detected by the HA test. Amplification by virus isolation in embryonated chicken eggs or cell culture is typically required before HA activity can be detected from a clinical sample. The test is, to some extent, quantitative as one hemagglutinating unit (HAU) is equal to approximately 5-6 log10 of virus. It is inexpensive and relatively simple to conduct. Several factors (e.g., the quality of chicken erythrocytes, laboratory temperature, laboratory equipment, technical expertise of the user) may contribute to slight differences in the interpretation of the test each time it is run. This chapter will describe the methods validated and used by the US National Veterinary Services Laboratories for screening and identification of hemagglutinating viruses.

Purification and characterisation of a xylose-specific mitogenic lectin from Fusarium sambucinum.

A xylose-specific intracellular lectin, showing hemagglutination only with rabbit erythrocytes was purified from mycelium of Fusarium sambucinum which was designated as FSL. An array of anion exchange chromatography on Q-Sepharose and gel-exclusion chromatography on Sephadex G-100 resulted in 84.21% yield and 53.99-fold purification of lectin with specific activity of 169.53 titre/mg. Molecular weight of FSL determined by SDS-PAGE was 70.7 kDa, which was further confirmed by gel-exclusion chromatography. Native-PAGE analysis of FSL showed its monomeric nature. FSL was observed to be a glycoprotein containing 2.9% carbohydrate. Hapten inhibition profile of FSL displayed its strong affinity towards D-xylose (MIC 1.562 mM), L-fucose (MIC 6.25 mM), D-mannose (MIC 3.125 mM), fetuin (MIC 15.62 µg/mL), asialofetuin (MIC 125 µg/mL) and BSM (MIC 3.125 µg/mL). Affinity of FSL towards xylose is rare. FSL was found stable over a pH range 6.0-7.5 and upto 40 °C temperature. Hemagglutination activity of FSL remained unaffected by divalent ions. Lectin concentration of 5 µg/mL was found sufficient to stimulate proliferation of murine spleen cells and its concentration 75 µg/mL exhibited highest mitogenic potential. FSL exhibited maximum mitogenic stimulatory index of 14.35. The purification, characterisation and mitogenicity of F. sambucinum lectin has been reported first time.

A novel simple assay system for the detection of human platelet antigen 15 (HPA-15) alloantibodies based on three techniques: an HPA-15 expressing cell line, a monoclonal antibody-specific antigen-capture method and mixed-passive haemagglutination.

BACKGROUND AND OBJECTIVES: To detect HPA-15 alloantibodies, we previously developed a human platelet antigen 15 (HPA-15)-expressing cell line-based modified rapid monoclonal antibody immobilization of platelet antigen (CL-MR-MAIPA) assay. In this study, the protocol was modified for easier performance by introducing the mixed-passive haemagglutination (MPHA) principle. MATERIAL AND METHODS: In total, 20 samples that tested negative for HPA alloantibodies and eight that tested positive for HPA-15 alloantibodies (two and six positive for HPA-15a and HPA-15b antibodies, respectively) by CL-MR-MAIPA assay were used in this study. HPA-15 cell lines were incubated with serum/plasma and then solubilized. The lysate was transferred to a round-bottom well, which was coated with anti-human CD109 monoclonal antibodies. After incubation and repeated washings, sheep red blood cells, coated with anti-human IgG, were added to the wells. Haemagglutination was assessed the next day. RESULTS: The proposed cell line-based immune complex capture-dependent mixed-passive haemagglutination (CL-IC-MPHA) assay consisted of four steps, but required only 2 h to perform, except for overnight incubation for haemagglutination. Two HPA-15a alloantibody samples were reactive only for HPA-15a cells, and six HPA-15b alloantibody samples were reactive only for HPA-15b cells with the CL-IC-MPHA assay. The 20 samples that tested negative for HPA alloantibodies did not react with HPA-15a or HPA-15b cells. These data indicated that the CL-IC-MPHA assay was highly specific and sensitive. Unfortunately, the CL-IC-MPHA assay's analytic sensitivity was twofold to eightfold lower than that of the CL-MR-MAIPA assay. CONCLUSION: A novel, easy-to-perform protocol was successfully developed to detect HPA-15 alloantibodies with high specificity and sensitivity.

Comparison of ABO isoagglutinin titres by three different methods: tube haemagglutination, micro-column agglutination and automated immunohematology analyzer based on erythrocyte-magnetized technology.

BACKGROUND AND OBJECTIVES: ABO isoagglutinin titre is important for evaluating and monitoring ABO-incompatible (ABOi) stem cells or solid organ transplantations. There are several methods to measure the titre level, including the tube haemagglutination method, micro-column agglutination and erythrocyte-magnetized technology (EMT). However, few studies have reported isoagglutinin measured by EMT. Here, we compared the isoagglutinin titre of normal individuals obtained by an automated instrument with that obtained by conventional manual methods to evaluate the feasibility of replacing the manual method with the automated instrument. MATERIALS AND METHODS: The ABO isoagglutinin titre was measured on residual samples of healthy individuals who visited the health promotion centre of the National Cancer Center, Korea, from April to October 2015. Samples from 120 patients were collected, which included 20 males and 20 females for each blood group (A, B and O). IgM and IgG ABO isoagglutinin titres of each blood group were measured by the tube haemagglutination, micro-column agglutination and EMT techniques. The median (minimum-maximum) titres were compared, and the concordance between two methods was evaluated with the rate of results showing within one titre difference. RESULTS: The median ABO IgM and IgG titres of all blood groups obtained by the EMT method were higher than that obtained by the conventional tube haemagglutination and micro-column agglutination. CONCLUSION: The agreement between the two methods was comparable in case of IgM but low in IgG.

Development of a pooled antigen for use in the macroscopic slide agglutination test (MSAT) to detect Sejroe serogroup exposure in cattle.

This study aimed to develop and evaluate a pooled antigen for use in the macroscopic slide agglutination test (MSAT) to detect cattle positive for the Sejroe serogroup. To this end, 193 bovine serum samples from different Pará State regions (Amazonia) were subjected to a reference microscopic agglutination test (MAT) for the serological diagnosis of leptospirosis using 11 serovars representing the Sejroe serogroup: Hardjo-prajitno; Hardjo-bovis; Sejroe; Wolffi; Guaricura (Bov.G.); Guaricura (M4/98); Ricardi; Gorgas; Recreo; Polonica and Medanensis. The three most prevalent serovars in the MAT were selected for the development of a pooled antigen for use in MSAT; subsequently, the 193 serum were assessed with the macroscopic slide agglutination test (MSAT) containing the developed antigen. The Kappa test was used to determine the general agreement between the MAT and MSAT results. As a result, of the 193 serum samples, 155 (80.3%) were reactive, and 38 (19.7%) were non-reactive in the MAT; Hardjo-prajitno, Wolffi and Medanensis were the three most prevalent serovars. Of the 193 serum samples tested in the MSAT using the developed pooled antigen, 114 were reactive (59.0%), and 79 (41.0%) were non-reactive; the Kappa coefficient was 0.52 (CI 95%, 0.40-0.63), indicating moderate agreement between the two tests. The MSAT with the pooled antigen including the most prevalent serovars detected bovines with the Sejroe serogroup exposure, mainly in animals with high titters in the MAT, and could be used to screen herds suspected of acute infection by this serogroup in Pará State.

Using Hemagglutination, Surface Shearing, and Acid Treatment to Study Fimbriae in Proteus mirabilis.

A critical first step in bacterial virulence and colonization is adherence to mucosal surfaces, often mediated by fimbriae and other protein adhesins. Here are described three short methods for studying these surface proteins and their behaviors, using protocols developed for the opportunistic pathogen Proteus mirabilis. Unlike the mannose-binding type 1 fimbriae produced by Escherichia coli, most P. mirabilis strains produce mannose-resistant/Proteus-like (MR/P) fimbriae. Both types of fimbrial production and adhesion can be easily demonstrated by a simple and economical hemagglutination assay which uses a model system of erythrocytes. The second and third fimbrial methods presented here show how to shear surface-exposed proteins and use acid treatment to separate interlocked fimbrial subunits into monomers.

Missed detections of influenza A(H1)pdm09 by real-time RT-PCR assay due to haemagglutinin sequence mutation, December 2017 to March 2018, northern Viet Nam.

INTRODUCTION: There are two methods of reverse transcription polymerase chain reaction (RT-PCR) that have been the common methods to detect influenza infections: conventional and real-time RT-PCR. From December 2017 to March 2018, several missed diagnoses of influenza A(H1)pdm09 using real-time RT-PCR were reported in northern Viet Nam. This study investigated how these missed detections occurred to determine their effect on the surveillance of influenza. METHODS: The haemagglutinin (HA) segments of A(H1N1)pdm09 from both real-time RT-PCR positive and negative samples were isolated and sequenced. The primer and probe sets in the HA gene were checked for mismatches, and phylogenetic analyses were performed to determine the molecular epidemiology of these viruses. RESULTS: There were 86 positive influenza A samples; 32 were A(H1)pdm09 positive by conventional RT-PCR but were negative by real-time RT-PCR. Sequencing was conducted on 23 influenza (H1N1)pdm09 isolates that were recovered from positive samples. Eight of these were negative for A(H1)pdm09 by real-time RT-PCR. There were two different mismatches in the probe target sites of the HA gene sequences of all isolates (n = 23) with additional mismatches only at position 7 (template binding site) identified for all eight negative real-time RT-PCR isolates. The prime target sites had no mismatches. Phylogenetic analysis of the HA gene showed that both the positive and negative real-time RT-PCR isolates were grouped in clade 6B.1; however, the real-time RT-PCR negative viruses were located in a subgroup that referred to substitution I295V. CONCLUSION: Constant monitoring of genetic changes in the circulating influenza A(H1N1)pdm09 viruses is important for maintaining the sensitivity of molecular detection assays.

An Inulin-Specific Lectin with Anti-HIV-1 Reverse Transcriptase, Antiproliferative, and Mitogenic Activities from the Edible Mushroom Agaricus bitorquis.

A novel lectin (ABL) was purified from the dried fruiting bodies of Agaricus bitorquis. An efficient 3-step purification protocol involved two consecutive steps of ion exchange chromatography on Q-Sepharose and SP-Sepharose and gel filtration by FPLC on Superdex 75. ABL is a monomeric protein with the molecular mass of 27.6 kDa, which is different from other lectins from genus Agaricus. Its N-terminal amino acid sequence is EYTISIRVYQTNPKGFNRPV which is unique and sharing considerably high similarity of other mushroom lectins. The hemagglutinating activity of the lectin was inhibited by inulin. Based on hemagglutination tests, ABL prefers rabbit, human type A, and AB erythrocytes to human type B and O erythrocytes. The lectin inhibits the activity of HIV-1 reverse transcriptase and the proliferation of leukemia cell (L1210) with an IC50 value of 4.69 and 4.97 µM, respectively. Furthermore, ABL demonstrates the highest mitogenic activity with a response of 24177.7 ± 940.6 [3H-methyl] thymidine counts per minute (CPM) at a concentration of 0.91 µM.