Serological Groups Research Articles

СЕРОГРУППОВАЯ ПРИНАДЛЕЖНОСТЬ β–ГЕМОЛИТИЧЕСКИХ СТРЕПТОКОККОВ, ИЗОЛИРОВАННЫХ ОТ РАЗНЫХ ВИДОВ ЖИВОТНЫХ И ПТИЦ В СЕЛЬСКОХОЗЯЙСТВЕННЫХ БИОТОПАХ КАБАРДИНО-БАЛКАРСКОЙ РЕСПУБЛИКИ

The serogroup affiliation of β-hemolytic streptococci isolated from clinically healthy farm animals of various species, from pathological material from sick, dead and forcedly slaughtered animals, as well as those isolated in premises where farm animals are kept in farms of various forms of ownership of the Kabardino-Balkarian Republic was studied. The hemolytic properties of streptococci were studied on blood (5% sheep erythrocytes) agar. The determination of the serogroup affiliation of streptococci was carried out by us in accordance with generally accepted methods, in accordance with which 639 cultures were tested that showed β-hemolysis on blood agar, including: from cattle - 207 (32.3%), from small cattle - 167 (26.1%), from horses - 65 (10.1%), from pigs - 39 (8.3%), from dogs - 73 (11.1%), synanthropic rodents - 40 (6.1%) %), synanthropic birds - 24 (3.7%), as well as 24 (3.7%) cultures isolated from air samples and washings from walls and floors in livestock buildings. Of 639 cultures of β-hemolytic streptococci, serogroup affiliation was determined in 549 (86.9%). At the same time, 30 (5.5%) were assigned to group A, 131 (23.8%) to group B, 158 (28.7%) to group C, 81 (14.7%) to group G , to group F - 24 (4.3%), to group E - 23 (4.1%), to group P - 15 (2.7%), to group U - 16 (2.9%) and 71 (13.1%) cultures could not be identified as belonging to one or another serological group. Streptococci with β-hemolytic properties are widely distributed among cattle, horses, small cattle, dogs and pigs living in agricultural biotopes.

Analysis of the results of chromosomal trisomies 21, 18 and 13 screening among 40 628 women by non-invasive prenatal testing

To assess the clinical value of non-invasive prenatal testing (NIPT) for the screening of trisomy and copy number variations (CNVs) of chromosomes 21, 18 and 13. From January 2015 to December 2019, 40 628 pregnant women underwent NIPT testing using high-throughput sequencing and bioinformatics analysis to test the cell-free fetal DNA in maternal plasma. High-risk pregnant women underwent invasive prenatal diagnosis, while low-risk ones were followed up by telephone. The three most common indications included intermediate risk of serological screening, high risk of serological screening and advanced maternal age. Among all pregnant women, 257 cases were detected as trisomy 21, 18 and 13 (170, 49 and 38 cases, respectively). 227 cases chose invasive prenatal diagnosis, with respectively 122, 28 and 10 cases confirmed. The positive predictive value (PPV) was 81.33% (122/150), 65.12% (28/43), 29.41% (10/34), respectively. Two false negative cases of trisomy 18 were found during follow-up. Meanwhile, NIPT has detected 46 cases (15, 16 and 15 cases, respectively) CNVs on chromosomes 21, 18 and 13, among which 37 cases underwent invasive prenatal diagnosis. There were 5, 3 and 5 positive cases, which yielded a PPV of 41.67% (5/12), 25%(3/12) and 33.33%(5/15), respectively. Two other chromosome CNVs were accidentally discovered among the false positive samples. The incidence of chromosomal abnormalities in the serological screening high-risk group was 52.02%, which was significantly higher than other groups. NIPT has a high sensitivity and specificity for the screening of trisomies 21, 18 and 13, while its accuracy for detecting CNVs of chromosomes 21, 18 and 13 needs to be improved. As a screening method, NIPT has a great clinical value, though there are still limitations of false positive and false negative results.Comprehensive pre- and post-test genetic counseling should be provided to the patients.

Role of wild animals in epizootology of infectious diseases inYakutia

It is known that wild animals and birds can be reservoirs and carriers of many infectious diseases of animals and humans. A cadastre of disadvantaged anthrax settlements was developed based on the study of epizootology, which will help optimize epizootological and epidemiological measures for the prevention of anthrax in animals (wild and domestic) and the population. We first identified yersinia (Yersinia enterocolitica and Yersinia pseudotuberculosis) from the material for shooting moose and roe deer living in the Central zone of Yakutia. Antibodies to the serogroups Leptospira Pomona, Grippotyphosa, and Icterohaemorrhagiae serogroups were detected in forest bisons exported from Canada to Yakutia for acclimatization. We developed a method for sampling frozen urine with snow at low temperatures (minus 10-50 ?С) to diagnose leptospirosis of wild animals and dogs, in places of natural habitat of wild mammals (without seizure and capture). The bactericidal effect of the probiotic strains of bacteria Bacillus subtilis TNP-3 and TNP-5 on the causative agent of leptospirosis of various serological groups has been established. The methods are protected by the Russian Federation patents for the invention. There was marked disease and mortality of roe deer from salmonellosis caused by Sal. abortus equi. There has been established the circulation of viruses of infectious rhinotracheitis, diarrhea in the deer population of the Arctic regions, the causative agents of which may be migratory birds and animals of the disadvantaged settlements. In the period of intensive exploration of Actica, climate warming and changes in the fauna, the migration routes of wild animals and birds, growing threat of zoonoses it is necessary to conduct large-scale monitoring of infections, especially viral diseases.

Prevalence of Hepatitis B virus serological groups in rheumatoid arthritis and association of previous hepatitis B virus infection with demographic data and parenteral therapies

Introduction: The aim of this study is to determine the frequency of Hepatitis b virus (HBV) serological groups in Rheumatoid arthritis (RA) and to compare the demographic characteristics and frequency of parenteral therapies between patient groups with and without previous HBV infection.
 Methods: Charts of RA patients were examined retrospectively. HBsAg, anti-HBc IgG, and anti-HBs test results were screened. All participants were divided into 3 serological groups (patients naive to HBV infection, previous HBV infection, vaccinated). Those with previous HBV infection were further divided into 3 serological subgroups (naturally immune, anti-HBc IgG positive only, chronic HBV infection). Findings were compared between RA patients with and without previous HBV infection.
 Results: Four hundred and fifty-one patients (female/male: 343/108) were included. The prevalence of patients naive to HBV infection, with previous HBV infection and vaccinated were 59.4%, 33.7%, and 6.9%, respectively. The prevalence of patients with naturally immune, anti-HBc IgG positive only, and chronic HBV infection were 25.7%, 4.4%, and 3.5%, respectively. Age in RA patients with and without previous HBV infection was 60.8±12.4 and 56.7±14.2 years, respectively(p

Prenatal prediction of fetal Rh C, cand E status by amplification of maternal cfDNA and deep sequencing.

The Rh blood group system has considerable clinical importance. The C, c, and E antigens are targets of alloantibodies. Anti-C, anti-c or anti-E alloreactive antibodies produced in pregnant women can cause anemia of a fetus carrying the corresponding antigens. Based on NGS technology, we have developed a noninvasive diagnostic assay to predict the fetal blood group of C, c or E antigens by sequencing cell-free DNA (cfDNA) during pregnancy. The SNVs underlying either the C, c or E antigens were PCR amplified and sequenced using NGS on a MiSeq instrument. The DNA sequences encoding the C, c or E antigen were counted, as were the number of total sequences. Based on the percentage of fetally derived target SNVs inherited from the father, the fetal blood group could be predicted. The results of 55 consecutive RHCE prenatal analyses with postnatal serological blood group determination of 30 newborns showed no discordant results. A threshold discerning positive from negative samples was set at 0.05% specific reads. Noninvasive, prenatal prediction of fetal blood groups by sequencing cfDNA for the detection of low-level RHCE*C, RHCE*c and RHCE*E sequences was established as an accurate and robust assay applicable for use in clinical settings.

Correlation Between Skin and Affected Organs in 52 Sclerodermic Patients Followed in a Diseases Management Team: Development of a Risk Prediction Model of Organ-Specific Complications.

ObjectiveTo identify the existence of a correlation among the various organs affected, focusing primarily on immuno-dermatological aspects, and to create a risk prediction model of organ-specific complications.Material and MethodsFifty-two patients with stable scleroderma, followed between 2015 and 2019, were investigated through an extensive multidisciplinary evaluation in the last year.ResultsPatients with lung involvement presented a worse degree of skin fibrosis than patients without it (p <0.001). No relationship was observed for the heart, kidney, and esophagus. Patients with pulmonary involvement had a lower pressure of the low esophagus sphincter and a higher Warrick score than patients without it (p <0.05). Age was significantly higher in patients with kidney involvement. Diffuse scleroderma patients had a worse pulmonary impairment than limited scleroderma patients (p <0.05). The manometric “sclerodermic” pattern was observed to be the most frequent (55.6%, p <0.05) in dcSSc patients while the sclerodermic and normal pattern were equally represented (41.2 and 32.4% respectively, p <0.05) in lcSSc patients. When compared to the negative serological groups, anti-Scl-70 positive patients presented a worse lung involvement while anti-centromere patients presented a better lung outcome (p <0.05). PM-Scl 100/75 positive patients presented mostly a pulmonary fibrotic pattern (p <0.05) and, also, heart complications were more likely associated with anti PM-Scl 100/75 positivity (p <0.05). The risk prediction model for organ-specific complications had an accuracy of 84.4% (95%CI 78, 89) in complication-site prediction, AUC of 0.871, 86% of sensitivity, and 83% of specificity, Cohen’s Kappa (k) of 0.68.ConclusionsOut of all the organs studied, the skin is the one that correlates with the lung. Patients with a diffuse form of disease presented more frequently the anti Scl-70 antibody and had a worse lung and esophageal involvement (scleroderma pattern) than the negative group. Conversely, patients with limited disease presented all positive for the anti-centromere antibody with a better lung involvement than the negative group, without any difference among the esophageal manometric pattern. Anti PM-Scl 100/75 antibody patients were associated with pulmonary fibrosis and presented cardiac involvement. The model created has demonstrated excellent values of sensitivity, specificity, and accuracy, but further studies are needed for validation.

Streptococcus vicugnae sp. nov., isolated from faeces of alpacas (Vicugna pacos) and cattle (Bos taurus), Streptococcus zalophi sp. nov., and Streptococcus pacificus sp. nov., isolated from respiratory tract of California sea lions (Zalophus californianus).

Four novel independent strains of Streptococcus spp. were isolated from faeces of alpaca (SL1232T), cattle (KCJ4950), and from respiratory tract of wild California sea lions (CSL7508T, CSL7591T). The strains were indole-, oxidase- and catalase-negative, non-spore-forming, non-motile Gram-positive cocci in short and long chains, facultative anaerobes. The 16S rRNA gene of SL1232T and KCJ4950 shared 99.40-99.60% nucleotide similarity to strains of S. equinus, S. lutetiensis, S. infantarius, and the 16S rRNA gene of CSL7508T and CSL7591T demonstrated 98.72 and 98.92% similarity, respectively, to S. marimammalium. All other known Streptococcus species had the 16S rRNA gene sequence similarities of ≤95%. The genomes were sequenced for the novel strains. Average nucleotide identity (ANI) analysis for strains SL1232T and KCJ4950, showed the highest similarity to S. equinus, S. lutetiensis, and S. infantarius with 85.21, 87.17, 88.47, 85.54, 87.47 and 88.89%, respectively, and strains CSL7508T and CSL7591T to S. marimammalium with 87.16 and 83.97%, respectively. Results of ANI were confirmed by pairwise digital DNA-DNA hybridization and phylogeny, which also revealed that the strains belong to three novel species of the genus Streptococcus. Phenotypical features of the novel species were in congruence with closely related members of the genus Streptococcus and gave negative reactions with the tested Lancefield serological groups (A-D, F and G). MALDI-TOF mass spectrometry supported identification of the species. Based on these data, we propose three novel species of the genus Streptococcus, for which the name Streptococcus vicugnae sp. nov. is proposed with the type strain SL1232T (=NCTC 14341T=DSM 110741T=CCUG 74371T), Streptococcus zalophi sp. nov. is proposed with the type strain CSL7508T (=NCTC 14410T=DSM 110742T=CCUG 74374T) and Streptococcus pacificus sp. nov. is proposed with the type strain CSL7591T (=NCTC 14455T=DSM 111148T=CCUG 74655T). The genome G+C content is 36.89, 34.85, and 35.34 % and draft genome sizes are 1906993, 1581094 and 1656080 bp for strains SL1232T, CSL7508T, and CSL7591T, respectively.

Antibodies against HLA cross-reactivity groups: From single antigen bead assay to immunoinformatics interpretation of epitopes

Identification of anti-human leukocyte antigen (HLA) antibodies (Abs) is based on Luminex™ technology. We used bioinformatics to (i) study the correlations of mean fluorescence intensities (MFIs) for all the possible allele pairs, and (ii) determine the degree of epitope homology between HLA antigens.Using MFI data on anti-HLA Abs from 6000 Luminex™ assays, we provide an updated overview of class I and II HLA antigen cross-reactivity in which each node corresponded to an allele and each link corresponded to a strong correlation between two alleles (Spearman’s ρ > 0.8). We compared these correlations with the serological groups and the results of an epitope analysis.The strongest correlations concerned allele-specific Abs directed against the same antigen. For the HLA-A locus, the highest values of Spearman’s ρ reflected broad specificity. For the HLA-B locus, graphs defined the HLA-Bw4 public epitope, and correlations between HLA-A and -B alleles were only present for beads with the same Bw4 public epitope. For the HLA-C locus, we identified two groups that differed with regard to their KIR ligand subclassification. Lastly, the HLA-DRB1 subgroups were part of a network. In the epitope analysis, Spearman’s ρ was related to the number of matched epitopes within pairs of alleles.The combination of Spearman’s ρ with simple, undirected graphing constitutes an effective tool for understanding routinely encountered cross-reactivity profiles. Based on this model, we have implemented an online data visualization tool available at http://cusureau.pythonanywhere.com/.

Rapid Identification for Serotyping of African Swine Fever Virus Based on the Short Fragment of the EP402R Gene Encoding for CD2-Like Protein

Abstract The first confirmed case of African swine fever (ASF) in Vietnam was officially reported in February 2019. To date, the ASF virus (ASFV) has been detected in all 63 cities/provinces in Vietnam. In order to get a better understanding of the potential role of the EP402R gene in a grouping of ASFV serotypes, thirty ASFV sequences of EP402R genes (accession numbers: MN711757-86) from North Central Coast of Vietnam and 68 well-known references of serotype groups from previous studies were further analyzed. Interestingly, we found that a short fragment of 90 nucleotides was very typical for 8 serological groups of ASFVs. A primer set was designed to amplicon the short fragment of 90 nucleotides using the Primer3 program to establish a simplified method for the serotyping of ASFV. Our results indicated that phylogenetic analysis of the short fragment (90 nucleotides) of the EP402R gene is a very specific and useful method for ASFV serotyping when compared to the previous method using a long fragment (816 nucleotides) of this gene and well-known serotype references based on haemadsorption inhibition (HAI) assay.

Incidence and impact of allele-specific anti-HLA antibodies and high-resolution HLA genotyping on assessing immunologic compatibility

The ability to identify specific HLA molecules against which a patient has alloantibodies has revolutionized assessment of immunologic compatibility. Anti-HLA antibodies are typically evaluated as reactive against well-defined serologic antigen groups. Thus, donor HLA genotyping is aimed at defining HLA at the serologic split-antigen level to avoid incompatible antigen-antibody combinations. However, anti-HLA antibodies can have reactivities not accurately described by well-defined serologic antigens. While existence of these antibodies is acknowledged, their precise impact on clinical practice is not clear. We performed a single-center review of 2 years of pre-and post-transplant anti-HLA antibody testing data combined with high-resolution HLA genotyping data for living and deceased organ donors to evaluate the clinical impact of anti-HLA antibodies with reactivities outside of commonly defined serologic antigen groups. We find approximately 15% of patients awaiting transplantation have alloantibodies with differential reactivity for HLA proteins encoded by specific alleles within a serologic antigen group. Allele-specific antibodies are associated with positive cellular crossmatches not accurately predicted by standard donor HLA genotyping and can manifest as post-transplant donor-specific antibodies. Our data highlights the importance of evaluating anti-HLA antibodies at the allele-level and provides evidence supporting utility for high-resolution HLA genotyping in solid organ transplantation.

MESORHIZOBIUM CICERІ ND-64 STRAIN — EFFECTIVE MICROSYMBIONT OF MODERN CHICKPEA VARIETIES

Objective. Study the competitiveness, complementarity and symbiotic activity of a new strain of chickpea nodule bacteria Mesorhizobium ciceri ND-64, study the influence of seed inoculation on the productivity and yield of chickpea varieties of Ukrainian selection under their cultivation in different soil and climatic zones of Ukraine. Methods. Serological, gas chromatography, field experiment and statistical. Results. The use of a new strain of M. ciceri ND-64 for pre-sowing bacterization of chickpea seeds of varieties Skarb, Admiral, Odysei, Budzhak, Triumf and Pamiat upon growing in field experiments in the Steppe zone against the background of the local population of nodule bacteria contributes to a significant increase in nitrogen-fixing nodules by 5 % to 67 %, an increase in the mass of nodules by 10 % to 67 % and nitrogenase activity 26 % to 150 % compared with the positive control (inoculation with the reference strain of M. ciceri H-12). The use of M. ciceri ND- 64 for pre-sowing bacterization of chickpea seeds under cultivation in the Steppe zone of Ukraine also had a positive effect on increasing the yield of chickpea — by 4 % to 18 % compared to the positive control. Inoculation with a new strain of chickpea seeds of varieties Skarb, Triumf and Pamiat contributed to the formation of higher number of nodules (by 57 % to 89 %), increaseed mass of nodules (2.2–2.9 times) and their nitrogenase activity (2–4 times) compared with the positive control upon cultivation in the Polissia zone on the fields where there is no population of chickpea rhizobia. Under these conditions, an increase in structural parameters of yield, the highest gain in chickpea yield, increase in photosynthetic activity and protein content in grain upon inoculation with M. ciceri ND-64 was shown. Obtaining a specific antisera by immunization of rabbits allowed to detect serological relatedness of M. ciceri ND-64, M. ciceri H-101, Mesorhizobium sp. ND-601 and M. ciceri ND-64, isolated from chickpea nodules of Skarb and Pamiat varieties. The competitiveness of M. ciceri ND-64 was determined using the immunological method in the field experiment. It was found that 100 % of nodules have been formed by the representatives of M. ciceri ND-64 in the variant where this serological group was applied for inoculation in the variant with inoculation of the strain M. ciceri ND-64 100 % of the nodules were formed by representatives of this serogroup. Conclusion. M. ciceri ND-64 strain is an effective microsymbiont of chickpea plants, due to its virulence, competitiveness, nitrogen-fixing properties. According to the results of field experiments, it was shown that the new strain, complementary to all studied varieties differing in seed size and shape, type of bush and average height, forms an effective symbiosis for growing chickpea plants both against the active local population of rhizobia and upon the absence of M. cicerі population in the soil. Symbiotic parameters upon seed treatment with suspension of M. ciceri ND-64 exceed these values in the variants with inoculation using the reference strain of M. ciceri H-12 and strains isolated from the nodules of each study variety. Therefore, M. ciceri ND-64 can be used as a bioagent of a microbial preparation for inoculation of chickpea of different varieties in order to form an effective bean-rhizobial symbiosis, increase the productivity of this culture and improve seed quality.

MESORHIZOBIUM CICERІ ND-64 STRAIN — EFFECTIVE MICROSYMBIONT OF MODERN CHICKPEA VARIETIES

Objective. Study the competitiveness, complementarity and symbiotic activity of a new strain of chickpea nodule bacteria Mesorhizobium ciceri ND-64, study the influence of seed inoculation on the productivity and yield of chickpea varieties of Ukrainian selection under their cultivation in different soil and climatic zones of Ukraine. Methods. Serological, gas chromatography, field experiment and statistical. Results. The use of a new strain of M. ciceri ND-64 for pre-sowing bacterization of chickpea seeds of varieties Skarb, Admiral, Odysei, Budzhak, Triumf and Pamiat upon growing in field experiments in the Steppe zone against the background of the local population of nodule bacteria contributes to a significant increase in nitrogen-fixing nodules by 5 % to 67 %, an increase in the mass of nodules by 10 % to 67 % and nitrogenase activity 26 % to 150 % compared with the positive control (inoculation with the reference strain of M. ciceri H-12). The use of M. ciceri ND- 64 for pre-sowing bacterization of chickpea seeds under cultivation in the Steppe zone of Ukraine also had a positive effect on increasing the yield of chickpea — by 4 % to 18 % compared to the positive control. Inoculation with a new strain of chickpea seeds of varieties Skarb, Triumf and Pamiat contributed to the formation of higher number of nodules (by 57 % to 89 %), increaseed mass of nodules (2.2–2.9 times) and their nitrogenase activity (2–4 times) compared with the positive control upon cultivation in the Polissia zone on the fields where there is no population of chickpea rhizobia. Under these conditions, an increase in structural parameters of yield, the highest gain in chickpea yield, increase in photosynthetic activity and protein content in grain upon inoculation with M. ciceri ND-64 was shown. Obtaining a specific antisera by immunization of rabbits allowed to detect serological relatedness of M. ciceri ND-64, M. ciceri H-101, Mesorhizobium sp. ND-601 and M. ciceri ND-64, isolated from chickpea nodules of Skarb and Pamiat varieties. The competitiveness of M. ciceri ND-64 was determined using the immunological method in the field experiment. It was found that 100 % of nodules have been formed by the representatives of M. ciceri ND-64 in the variant where this serological group was applied for inoculation in the variant with inoculation of the strain M. ciceri ND-64 100 % of the nodules were formed by representatives of this serogroup. Conclusion. M. ciceri ND-64 strain is an effective microsymbiont of chickpea plants, due to its virulence, competitiveness, nitrogen-fixing properties. According to the results of field experiments, it was shown that the new strain, complementary to all studied varieties differing in seed size and shape, type of bush and average height, forms an effective symbiosis for growing chickpea plants both against the active local population of rhizobia and upon the absence of M. cicerі population in the soil. Symbiotic parameters upon seed treatment with suspension of M. ciceri ND-64 exceed these values in the variants with inoculation using the reference strain of M. ciceri H-12 and strains isolated from the nodules of each study variety. Therefore, M. ciceri ND-64 can be used as a bioagent of a microbial preparation for inoculation of chickpea of different varieties in order to form an effective bean-rhizobial symbiosis, increase the productivity of this culture and improve seed quality.

The Evolution of Phenotypic Properties and Molecular Genetic Organization of Genomes of Vibrio Cholerae O1 El Tor Variant Strains Isolated from Patients and Environmental Objects in the Caucasus in 1970–1998

Summary. Introduction: The formation of highly pathogenic strains of Vibrio cholerae resistant to antibiotics determines the pathogenesis, clinical picture, epidemiology, and laboratory diagnosis of cholera. It is necessary to study the structure of the genome of V. cholerae of any serological groups isolated during routine monitoring of environmental objects or patients with acute intestinal infections in order to detect toxigenic genes inherent to epidemic strains of V. cholerae O1. Our objective was to study changes in phenotypic properties and molecular genetic bases of persistence, epidemic and pathogenetic potential of El Tor variant of Vibrio cholerae O1 isolated from patients and environmental objects in the Caucasus in 1970–1998. Materials and methods: We studied phenotypic and molecular genetic characteristics of 32 V. cholerae O1 strains isolated from patients and environmental objects in the Caucasus (1970–1998) using a microbiological assay and PCR test, respectively. Results: We established that the following biotypes of V. cholerae O1 were found in the Caucasus: a) El Tor, ctxA–, and Hly+ nontoxigenic strains of V. cholerae O1, typical in their phenotypic and molecular genetic properties. Their toxigenic potential is represented by exo- and endotoxins different from the enterotoxin of toxigenic V. cholerae; b) toxigenic El Tor, ctxABEL+, rtхC+, and Hly– variant biotypes of V. cholerae O1, typical in their phenotypic, molecular and genetic properties during outbreaks of invasive cholera, producing a CT-2 enterotoxin and containing genes responsible for persistent, pathogenic and pandemic potential, and c) typical in terms of their main phenotypic characteristics but molecularly genetically altered variants (hybrids) of El Tor variant of Vibrio cholerae O1 including El Tor ctxABCL+, rtxC+, Hly–. Conclusions: The main manifestation of evolutionary changes in a typical toxigenic vibrio of the El Tor variant biotype was the replacement of the ctxBEl gene in its genome with the ctxBCL gene encoding the classical type of enterotoxin (CT-1), which significantly increased the persistent, toxic, epidemic, and pandemic potential of genetically modified variants of El Tor biotype Vibrio cholerae. The genome of these strains contains an integrative and conjugative element SXT with genes for antibiotic multiresistance.

Early epitope-specific IgE antibodies are predictive of childhood peanut allergy

Peanut allergy is characterized by the development of IgE against peanut antigen. We sought to evaluate the evolution of epitope-specific (es)IgE and esIgG4 in a prospective cohort of high-risk infants to determine whether antibody profiles can predict peanut allergy after age 4 years. The end point was allergy status at age 4+ years; samples from 293 children were collected at age 3 to 15 months and 2 to 3 and 4+ years. Levels of specific (s)IgE and sIgG4 to peanut and component proteins, and 50 esIgE and esIgG4 were quantified. Changes were analyzed with mixed-effects models. Machine learning algorithms were developed to identify a combination of antigen- and epitope-specific antibodies that using 3- to 15-month or 2- to 3-year samples can predict allergy status at age 4+ years. At age 4+ years, 38% of children were Tolerant or 14% had Possible, 8% Convincing, 24% Serologic, and 16% Confirmed allergy. At age 3 to 15 months, esIgE profiles were similar among groups, whereas marked increases were evident at age 2 and 4+ years only in Confirmed and Serologic groups. In contrast, peanut sIgE level was significantly lower in the Tolerant group at age 3 to 15 months, increased in Confirmed and Serologic groups but decreased in Convincing and Possibly Allergic groups over time. An algorithm combining esIgEs with peanut sIgE outperformed different clinically relevant IgE cutoffs, predicting allergy status on an "unseen" set of patients with area under the curves of 0.84 at age 3 to 15 months and 0.87 at age 2 to 3 years. Early epitope-specific plus peanut-specific IgE is predictive of allergy status at age 4+ years.

Performance of non-invasive prenatal screening for sex chromosome aneuploidies and parental decision-making.

Performance of non-invasive prenatal screening for sex chromosome aneuploidies and parental decision-making.

Serological diversity in Flavobacterium psychrophilum: A critical update using isolates retrieved from Chilean salmon farms.

Chile is currently the second largest producer of farmed salmon worldwide, but Flavobacterium psychrophilum, as one of the most detrimental pathogens, is responsible for major losses during the freshwater culturing step in salmonid fish farms. An antigenic study conducted 10years ago reported four serological groups using 20 F.psychrophilum Chilean strains. To reduce disease outbreaks and to develop vaccine candidates, antigenic knowledge needs to be regularly updated using a significant number of additional recent F.psychrophilum isolates. The present study aimed at investigating the serological diversity of 118 F.psychrophilum isolates collected between 2006 and 2018 from farmed Atlantic salmon (Salmo salar), rainbow trout (Oncorhynchus mykiss) and coho salmon (Oncorhynchus kisutch). The current study supports an expansion of the known antigenic groups in Chile from 4 to 14. However, the use of the slide-agglutination technique for serotyping is costly, is labour-intensive and requires significant technical expertise. Addressing these points, the mPCR-based procedure was a very useful tool for serotyping the collected Chilean F.psychrophilum isolates. This technique revealed the presence of diverse mPCR serotypes (i.e. types 0, 1, 2 and 4). Therefore, mPCR should be employed to select the bacterial strain(s) for vaccine development and to conduct follow-up, selective breeding or epidemiological surveillance in Chilean fish farms. Given the presented findings, changes to Chilean fish-farming practices are vital for ensuring the continued productivity and well-being of farmed salmonids.

Laboratory errors for identification of the escherichia coli strains of the serological groups O6 and O25 as acute intestinal infections.

Were studied the genes encoding the virulence factors of 221 strains: E. coli O6:H1 (194) and E. coli O25:H4 (27), isolated in 2014-2018 from stool samples of children and adults examined according to epidemic indications. Molecular methods included PCR with hybridization-fluorescence and electrophoresis detection of amplified products. The strains did not have virulence genes for diarrheagenic E. coli (DEC) pathogroups EPEC, ETEC, EIEC, EHEC, EAggEC, and belonged to the phylogenetic group B2. They contained from four to eight genes encoding virulence factors of ExPEC: E. coli O6:H1 - pap (68,6%), sfa (87,6%), fimH (96,4%), hly (62,4%), cnf (74,7%), iutA (97,9%), fyuA (95,9%), chu (100%); E. coli O25:H4 - pap (66,7%), afa (22,2%), fimH (100%), hly (44,4%), cnf (44,4%), iutA (100%) , fyuA (100%), chu (100%). The antimicrobial susceptibility testing to 6 classes of antimicrobials (beta-lactams, fluoroquinolones, aminoglycosides, nitrofurantoin, sulfanilamide, trimethoprim / sulfamethoxazole) according the EUCAST. 60,3% of E. coli O6:H1 were sensitive to antibiotics, E. coli O25:H4 remained sensitive to carbapenems and nitrofurans. Extended-spectrum cephalosporins resistance was due to the production ESBL (CTX-M). The 57,1% resistant strains of E. coli O6:H1 and 100% of E. coli O25:H4 strains belonged to the MDR phenotype. The XDR phenotype had one in five MDR strains of E. coli O6:H1 and E. coli O25:H4. All strains of E. coli O25:H4 belonged to ST131. Given the important role of E. coli in human pathology, detection of virulence genes should be performed to confirm the etiological significance of the isolated strain.

Phylogenetic Analyses of Xanthomonads Causing Bacterial Leaf Spot of Tomato and Pepper: Xanthomonas euvesicatoria Revealed Homologous Populations Despite Distant Geographical Distribution.

Bacterial leaf spot of tomato and pepper (BLS), an economically important bacterial disease caused by four species of Xanthomonas (X. euvesicatoria (Xe), X. vesicatoria (Xv), X. gardneri (Xg), and X. perforans (Xp)), is a global problem and can cause over 50% crop loss under unfavorable conditions. Among the four species, Xe and Xv are prevalent worldwide. Characterization of the pathogens is crucial for disease management and regulatory purposes. In this study, we performed a multilocus sequence analysis (MLSA) with six genes (hrcN, dnaA gyrB, gapA, pdg, and hmbs) on BLS strains. Other Xanthomonas species were included to determine phylogenetic relationships within and among the tested strains. Four BLS species comprising 76 strains from different serological groups and diverse geographical locations were resolved into three major clades. BLS xanthomonads formed distinct clusters in the phylogenetic analyses. Three other xanthomonads, including X. albilineans, X. sacchari, and X. translucens pv. undolusa revealed less than 85%, 88%, and 89% average nucleotide identity (ANI), respectively, with the other species of Xanthomonas included in this study. Both antibody and MLSA data showed that Xv was clearly separated from Xe and that the latter strains were remarkably clonal, even though they originated from distant geographical locations. The Xe strains formed two separate phylogenetic groups; Xe group A1 consisted only of tomato strains, whereas Xe group A2 included strains from pepper and tomato. In contrast, the Xv group showed greater heterogeneity. Some Xv strains from South America were closely related to strains from California, while others grouped closer to a strain from Indiana and more distantly to a strain from Hawaii. Using this information molecular tests can now be devised to track distribution of clonal populations that may be introduced into new geographic areas through seeds and other infected plant materials.

Presence of Antibodies Against Leptospira interrogans Serovar hardjo in Serum Samples from Cattle in Ukraine.

The article presents data on serological studies of 573 sera samples of cattle that were collected from the farms affected by leptospirosis in different regions of Ukraine in the period of 2014–2015. Samples were investigated by the microscopic agglutination test (MAT), which was conducted within eight serological groups of Leptospira and nine serovars: Sejroe (serovars polonica and hardjo), Hebdomadis (serovar kabura), Tarassovi (serovar tarassovi), Pomona (serovar pomona), Grippotyphosa (serovar grippotyphosa), Canicola (serovar canicola), Icterohaemorrhagiae (serovar copenhageni), and Australis (serovar bratislava). The circulation of L. interrogans serovar hardjo among cattle has been observed in all 11 regions of Ukraine investigated within 25.8–60.0% of the leptospirosis-positive serum samples in these regions. Antibodies in the cattle sera against serovar hardjo (serogroup Sejroe) were detected in 139 of the 370 cows reacting positively in MAT. Overall, they were detected in 24.3% animals out of the total of 573 cows investigated. These are the preliminary results, however, in our opinion, they should allow to include the serovar hardjo in a standard panel of strains for MAT in Ukraine.

Comparison of serology and molecular detection of common red cell antigens in multitransfused thalassemia major and sickle cell disease patients

BackgroundSerological testing for extended RHCcEe, Kell, Kidd and Duffy blood grouping from multitransfused patients may not give correct blood grouping of the recipient. Hence molecular testing for these blood groups was compared with serological groups in a cohort of multitransfused thalassemia mjor and sickle cell anaemia patients. ObjectiveMolecular genotyping of antigens of Rh (D, C, c, E, e), Kell (K, k), Duffy (Fya, Fyb) and Kidd (Jka, Jkb) blood group antigens by PCR and PCR-RFLP methods and comparison of predicted genotypes with their serological phenotypes. Materials and methodsA cohort of multitransfused thalassemia and sickle cell anemia patient were serologically and molecularly tested for RHCc, RHEe, K, k Fya, Fyb, Jka and Jkb antigens and compared. Serological testing was done by tube agglutination and molecular testing was done either by allele specific PCR or by RFLP technique just before next transfusion. ResultsIn more than 80% of the cases recipient’s molecular testing blood groups were at variance with serologically tested blood groups (p < 0.0001). Mixed field reactions in serological typing were common. In sickle cell anemia patients no discrepancy was found. Molecular technique results were checked by Sanger’s sequencing. DiscussionExtended phenotyping in multitransfused thalassemia patients by serological technique often donot detect the exact red cell phenotype of the recipient and molecular techniques for such grouping is preferable, especially in multitransfused thalassemia patients where red cells from previous transfusions continues to be present in significant numbers whenever the testing is done.