Latex Agglutination Assay Research Articles

Comparison of a Lateral Flow Assay and a Latex Agglutination Test for the Diagnosis of Cryptococcus Neoformans Infection

Infections by the basidiomycete yeast Cryptococcus neoformans are life-threatening diseases claiming more than 600,000 lives every year. The most common manifestation is cryptococcal meningitis in AIDS patients. Diagnosis primarily relies on antigen testing from serum and cerebrospinal fluid (CSF). Current guidelines recommend rapid antigen testing with a focus on point-of-care assays. Over the recent years, a range of new lateral flow assays (LFAs) was launched. There is still a lack of data evaluating the CE-certified Biosynex RDT CryptoPS LFA. We compared the performance of this LFA with a latex agglutination assay (LAA; Latex-Cryptococcus Antigen Detection System, IMMY) from blood and CSF samples. Blood and/or CSF samples of 27 patients with proven cryptococcal infections caused by different species and blood–CSF pairs of 20 controls were tested applying LFA and LAA. Upon combined analysis of blood and CSF, both assays were able to identify all C. neoformans infections. Based on CSF analysis only, the LFA and the LAA had sensitivities of 100% and 93%. Neither test gave false-positive results nor was reactive in two cases of C. non-neoformans/non-gattii species infections. Both assays have high sensitivities and specificities for the diagnosis of C. neoformans infection. Contrarily to the IMMY LAA, the RDT CryptoPS LFA is suitable as a point-of-care test but is limited in the quantification of antigen reactivity.

Emergence of Multi-Drug Resistance and Its Association With Uncommon Serotypes of Streptococcus agalactiae Isolated From Non-neonatal Patients in Thailand.

Group B streptococcus (GBS) or Streptococcus agalactiae is an opportunistic pathogen that causes serious illness in newborns, pregnant women, and adults. However, insufficient detection methods and disease prevention programs have contributed to an increase in the incidence and fatality rates associated with this pathogen in non-neonatal patients. This study aimed to investigate factors of the observed increased incidence by investigation of serotype distribution, virulence factors, and antimicrobial susceptibility patterns from invasive GBS disease among non-neonatal patients in Thailand. During 2017–2018, a total of 109 S. agalactiae isolates were collected from non-pregnant patients. There were 62 males and 47 females, with an average age of 63.5 years (range: 20 – 96). Serotypes were determined by latex agglutination assay and multiplex polymerase chain reaction (PCR)-based assay. Among those isolates, seven virulence genes (rib, bca, pavA, lmb, scpB, cylE, and cfb) were detected by PCR amplification, and were determined for their susceptibility to 20 antimicrobial agents using a SensititreTM Streptococcus species STP6F AST plate. Among the study isolates, serotype III was predominant (52.3%), followed by serotype V and serotype VI (13.8% for each), serotype Ib (11.9%), and other serotypes (8.2%). Of the seven virulence genes, pavA was found in 67.0%. Except for one, there were no significant differences in virulence genes between serotype III and non-serotype III. Study isolates showed an overall rate of non-susceptibility to penicillin, the first-line antibiotic, of only 0.9%, whereas the resistance rates measured in tetracycline, clindamycin, azithromycin, and erythromycin were 41.3, 22.0, 22.0, and 22.0%, respectively. Strains that were resistant to all four of those drugs were significantly associated with non-serotype III (p < 0.001). Using multi-locus sequence typing (MLST), 40.0% of the four-drug-resistant isolates belonged to serotype VI/ST1, followed by serotype Ib/ST1 (35.0%). Cluster analysis with global GBS isolates suggested that the multiple drug-resistant isolates to be strongly associated with the clonal complex (CC) 1 (p < 0.001). Compared to the 2014 study of 210 invasive GBS isolates conducted in 12 tertiary hospitals in Thailand, the proportion of serotype III has dramatically dropped from nearly 90% to about 50%. This suggests that resistances to the second-line antibiotics for GBS might be the selective pressure causing the high prevalence of non-serotype III isolates.

Predictive Value of Combination of D-dimer and Fibrinogen in Diagnosing Acute CVST.

Background:Cerebral venous sinus thrombosis (CVST) is an uncommon subtype of stroke, and the role of D-dimer and fibrinogen in early diagnosis of CVST has been studied with varying results. The present study aims to study the role of the combination of D-dimer and fibrinogen in early diagnosis of acute CVST.Methods:Forty consecutive confirmed acute CVST cases admitted at a tertiary care center were recruited for the study. D-dimer and fibrinogen were assessed by a rapid semiquantitative latex agglutination assay.Results:Out of the 40 CVST patients, 21 (52.50%) were females. The mean age of the patients was 37.58 years ± 19.17 years. Common clinical features were headache (N = 38 [95%]), papilloedema (N = 15 [37.5%]), and seizures (N = 12 [30%]). Although the sensitivity (75%) of the combination of D-dimer and fibrinogen assay was lower than that of D-dimer or fibrinogen alone, the specificity and positive predictive value (75% each) was higher.Conclusion:The combination of D-dimer and fibrinogen testing may aid in an early diagnosis of acute CVST and in better management.

Successful treatment of thrombotic thrombocytopenia with cerebral sinus venous thrombosis following Ad26.COV2.S vaccination

Successful treatment of thrombotic thrombocytopenia with cerebral sinus venous thrombosis following Ad26.COV2.S vaccination

Rapid Clinical Screening of Burkholderia pseudomallei Colonies by a Bacteriophage Tail Fiber-Based Latex Agglutination Assay.

ABSTRACTMelioidosis is a life-threatening disease in humans caused by the Gram-negative bacterium Burkholderia pseudomallei. As severe septicemic melioidosis can lead to death within 24 to 48 h, a rapid diagnosis of melioidosis is critical for ensuring that an optimal antibiotic course is prescribed to patients. Here, we report the development and evaluation of a bacteriophage tail fiber-based latex agglutination assay for rapid detection of B. pseudomallei infection. Burkholderia phage E094 was isolated from rice paddy fields in northeast Thailand, and the whole genome was sequenced to identify its tail fiber (94TF). The 94TF complex was structurally characterized, which involved identification of a tail assembly protein that forms an essential component of the mature fiber. Recombinant 94TF was conjugated to latex beads and developed into an agglutination-based assay (94TF-LAA). 94TF-LAA was initially tested against a large library of Burkholderia and other bacterial strains before a field evaluation was performed during routine clinical testing. The sensitivity and specificity of the 94TF-LAA were assessed alongside standard biochemical analyses on 300 patient specimens collected from an area of melioidosis endemicity over 11 months. The 94TF-LAA took less than 5 min to produce positive agglutination, demonstrating 98% (95% confidence interval [CI] of 94.2% to 99.59%) sensitivity and 83% (95% CI of 75.64% to 88.35%) specificity compared to biochemical-based detection. Overall, we show how a Burkholderia-specific phage tail fiber can be exploited for rapid detection of B. pseudomallei. The 94TF-LAA has the potential for further development as a supplementary diagnostic to assist in clinical identification of this life-threatening pathogen.IMPORTANCE Rapid diagnosis of melioidosis is essential for ensuring that optimal antibiotic courses are prescribed to patients and thus warrants the development of cost-effective and easy-to-use tests for implementation in underresourced areas such as northeastern Thailand and other tropical regions. Phage tail fibers are an interesting alternative to antibodies for use in various diagnostic assays for different pathogenic bacteria. As exposed appendages of phages, tail fibers are physically robust and easy to manufacture, with many tail fibers (such as 94TF investigated here) capable of targeting a given bacterial species with remarkable specificity. Here, we demonstrate the effectiveness of a latex agglutination assay using a Burkholderia-specific tail fiber 94TF against biochemical-based detection methods that are the standard diagnostic in many areas where melioidosis is endemic.

Production of Secreted Carbohydrates that Present Immunologic Similarities with the Cryptococcus Glucuronoxylomannan by Members of the Trichosporonaceae Family: A Comparative Study Among Species of Clinical Interest.

Glucuronoxylomannan (GXM) participates in several immunoregulatory mechanisms, which makes it an important Cryptococcus virulence factor that is essential for the disease. Trichosporon asahii and Trichosporon mucoides share with Cryptococcus species the ability to produce GXM. To check whether other opportunistic species in the Trichosporonaceae family produce GXM-like polysaccharides, extracts from 28 strains were produced from solid cultures and their carbohydrate content evaluated by the sulfuric acid / phenol method. Moreover, extracts were assessed for cryptococcal GXM cross-reactivity through latex agglutination and lateral flow assay methods. Cryptococcus neoformans and Saccharomyces cerevisiae were used as positive and negative controls, respectively. In addition to T. asahii, the species Trichosporon inkin, Apiotrichum montevideense, Trichosporon japonicum, Trichosporon faecale, Trichosporon ovoides, Cutaneotrichosporon debeurmannianum, and Cutaneotrichosporon arboriformis are also producers of a polysaccharide immunologically similar to the GXM produced by human pathogenic Cryptococcus species. The carbohydrate concentration of the extracts presented a positive correlation with the GXM contents determined by titration of both methodologies. These results add several species to the list of fungal pathogens that produce glycans of the GXM type and bring information about the origin of potential false-positive results on immunological tests for diagnosis of cryptococcosis based on GXM detection.

Correlation of Krebs von den Lungen-6 and fibronectin with pulmonary fibrosis in coronavirus disease 2019

ObjectiveCoronavirus Disease 2019 (COVID-19) caused by a novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is still spreading worldwide, which may progress to pulmonary fibrosis (PF), leading to the worsen outcome. As the markers of lung injury, the correlation of Krebs von den Lungen-6 (KL-6) and fibronectin (Fn) with pulmonary fibrosis in COVID-19 was still unclear. Methods113 patients diagnosed as COVID-19 were enrolled in this retrospective study, and divided into three categories as mild, moderate and severe cases. The concentrations of serum KL-6 and Fn at hospital admission were tested using the method of latex agglutination assay and immunoturbidimetic assay, respectively. ResultsCompared with that in the non-severe COVID-19 cases and normal control subjects, serum KL-6 concentration on admission was significantly higher in the severe group, which was positively correlated with C-reactive protein, and negatively correlated with lymphocytes count. Whereas, no obvious elevation in serum Fn concentration was investigated in COVID-19 patients with the different phenotypes. The severe cases displayed the higher incident rate of pulmonary fibrosis at hospital discharge. Compared with non-PF patients, the COVID-19 cases with PF had the higher serum KL-6 values. ConclusionSerum KL-6 concentration was significantly elevated in severe COVID-19 patients, which may be useful for evaluating the disease severity. For early prevention of the development of pulmonary fibrosis, high concentrations of serum KL-6 in the early stage of COVID-19 should be paid close attention.

Relationship between vaginal group B streptococcus colonization in the early stage of pregnancy and preterm birth: a retrospective cohort study

BackgroundAlthough infection and inflammation within the genital tract during pregnancy is considered a major risk factor for spontaneous preterm birth (PTB), there are few studies on association between vaginal microorganisms in the early stage of pregnancy and PTB. The aim of this study was to investigate relationship between vaginal Group B streptococcus (GBS) colonization, a leading cause of infection during pregnancy, in the early stage of pregnancy and PTB.MethodsThis single-center, retrospective cohort study utilized data from 2009 to 2017 obtained at TOYOTA Memorial Hospital. Women with singleton pregnancies who underwent vaginal culture around 14 weeks of gestation during their routine prenatal check-up were included. Vaginal sampling for Gram staining and culture was performed regardless of symptoms. GBS colonization was defined as positive for GBS latex agglutination assay. Statistical analysis was performed to determine the factors associated with PTB.ResultsOverall 1079 singleton pregnancies were included. GBS (5.7%) and Candida albicans (5.5%) were the most frequently observed microorganisms. The incidence of PTB (before 34 and before 37 weeks of gestation) were significantly higher in the GBS-positive group than in the GBS-negative group (6.6% vs 0.5%, p = 0.001 and 9.8% vs 4.3%, p = 0.047). Our multivariable logistic regression analysis revealed that GBS colonization was a factor associated with PTB before 34 and before 37 weeks of gestation (Odds ratio [OR] 15.17; 95% confidence interval [CI] 3.73–61.74), and OR 2.42; 95%CI 1.01–5.91, respectively).ConclusionsThe present study found that vaginal GBS colonization in the early stage of pregnancy was associated with PTB. Our study indicates that patients at a high risk for PTB can be extracted by a simple method using conventional culture method.

Clonal Diversity, Low-Level and Heterogeneous Oxacillin Resistance of Oxacillin Sensitive MRSA.

PurposeThis study investigates the phenotypic and genotypic resistance features of OS-MRSA clinical isolates and their distinctive sensitivities to oxacillin.Methods1200 clinical isolates of Staphylococcus aureus were enrolled in this study. Automated antibiotics susceptibility tests on VITEK-2 and BD Phoenix-100TM, cefoxitin disc diffusion method, oxacillin broth microdilution method, mecA, and mecC gene detection were performed to identify OS-MRSA. MLST, PFGE, SCCmec, and spa typing methods were employed to determine genotypes of OS-MRSA isolates. Heterogeneous resistance of OS-MRSA isolates was detected using the population analysis profiling method, and PBP2a latex agglutination assay was used to detect the expression of PBP2a protein for 14 OS-MRSA isolates and their highly resistant subpopulations.ResultsA total of 14 OS-MRSA isolates (1.17%, 14/1200) were identified, and all of the isolates were confirmed to be positive with the mecA gene and negative with the mecC gene. All of the 14 OS-MRSA isolates were identified as MSSA by VITEK-2, BD Phonenix-100, and oxacillin broth microdilution methods, while 21.43% (3/14) isolates were determined to be MRSA by the cefoxitin disk diffusion method. Genotypes of the 14 OS-MRSA isolates were diverse, and no dominant clones were identified. The prevalence of pvl gene among 14 OS-MRSA isolates was high up to 64.29% (9/14). All of the isolates showed heterogeneous resistance to oxacillin, while frequencies of the oxacillin-resistant subpopulations ranged from 10−9 to 10−5 and differed significantly among different isolates.ConclusionThe overall prevalence of OS-MRSA was relatively lower, but lower oxacillin MICs, low testing sensitivity of routine antibiotics susceptibility testing methods and weak PBP2a protein expression were observed in this study. 14 OS-MRSA showed diverse genotypes and universal heterogeneous resistance, and inaccurate laboratory identification and improper antimicrobial usage may promote the induction of highly resistant subpopulations and lead to treatment failure.

Staphylococcal cassette chromosome mec elements from Staphylococcus intermedius group (SIG) isolates from dogs in a center for veterinary diagnostics in Brazil

ABSTRACT: Methicillin resistance in the Staphylococcus intermedius group (SIG) has emerged in small animal practice. Methicillin-resistant SIG (MRSIG) members have been implicated as causes of infections in both companion animals and humans. Staphylococcal cassette chromosome mec (SCCmec) elements carry the mecA/C genes, which encode for the transpeptidase PBP2a (PBP2’) responsible for β-lactam antibiotic resistance in staphylococci. This study examined the SCCmec types of MRSIG isolates from different clinical specimens of dogs that exhibited methicillin MIC ≥ 0.5 μg/mL by an automated identification and susceptibility system in a Center for Veterinary Diagnostics in São Paulo, Brazil. Susceptibility to methicillin was determined by broth microdilution testing, and Oxoid® M.I.C.Evaluator® strips. PBP2a production was detected using a latex agglutination assay. SCCmec typing was performed according to the International Working Group on the Classification of Staphylococcal Cassette Chromosome Elements (IWG-SCC) guidelines. SCCmec type II (2A), SCCmec type III (3A), composite SCC structures consisting of a class A mec gene complex in addition to multiple ccr gene complexes, and non-typable SCCmec elements were reported in these MRSIG isolates. SCCmec type variants differing from those so far acknowledged by IWG-SCC were found, indicating new rearrangements in the genetic context of mecA in these canine MRSIG isolates.

Usefulness of the 'cosmos pattern' for differentiating between cervical gastric-type mucin-positive lesions and other benign cervical cystic lesions in magnetic resonance images.

To evaluate the usefulness of the 'cosmos pattern' (CP) on magnetic resonance (MR) images for differentiating between gastric-type mucin-positive lesions (GMPL) and gastric-type mucin-negative lesions (GMNL). This study included 131 patients with clinical suspicion of lobular endocervical glandular hyperplasia (LEGH) who underwent pelvic MR imaging and a Pap smear and/or latex agglutination assay. Differences in MR findings, such as cyst and solid component patterns, cervical location and T1-weighted image (T1WI) signal intensity, were compared between GMPL and GMNL. The diagnostic performances of the findings were assessed. The frequencies of CP (63.1%), upper part (UP) lesions (72.3%) and hypointense area compared with the cervical stroma on T1WI (61.3%) were significantly greater in GMPL than in GMNL (P < 0.05). The sensitivity, specificity, positive predictive value, negative predictive value and odds ratio of the CP for diagnosis of GMPL were 63.1%, 87.9%, 83.7%, 70.7% and 12.4, respectively. In GMNL, a 'macrocystic pattern' was observed in 65.2% of patients; an isointense or hyperintense area on T1WI was observed in 86.4% of patients. The sensitivity was highest (90.8%) when one or more of the following were observed: CP, UP lesion, or hypointense area on T1WI. The specificity was highest (95.5%) when the CP was observed as a hypointense area on T1WI. The CP is a highly specific finding for diagnosis of GMPL. If the CP is observed as a hypointense area compared with the cervical stroma on T1WI, GMPL (i.e., LEGH or gastric-type mucinous carcinoma) should be strongly suspected.

A therapeutic biomarker endocan in infective endocarditis

Background: In infectious endocarditis, previous biomarkers such as C-related protein (CRP) and procalcitonin (PCT) have been difficult to determine the appropriate timing of antibiotic treatment termination. Endocan is a novel biomarker of sepsis or bacteremia. In this study, we investigated effectiveness of endocan as a therapeutic biomarker in infective endocarditis. Methods and materials: This prospective study was conducted between September 2015 and November 2018. Subjects comprised patients aged ≥20 years admitted due to infective encocarditis. Infective endocarditis was diagnosed accodting to the modified Duke Criteria. Biomarkers were measured during the four following periods: day 0, on the admission day; day 35, between 3 and 5 days after onset of infection; and day 79, between 7 and 9 days after onset of infection; day 14–16, between 14 and 16 days after onset of infection; and day 2123, between 21 and 23 days after onset of infection; and day 2830, between 21 and 23 days after onset of infection. To measure serum endocan and PCT concentrations were measured by enzyme-linked immunosorbent assays, and CRP concentrations were measured by latex agglutination assays. Results: Nine patients were enrolled in this study. At the onset of infection, serum endocan was elevated (mean 2.21 ng/mL), and decreased during the course of treatment (mean 0.66 ng/mL). The decrease rate of serum endocan during the treatment was smaller than those of PCT and CRP. When the cut-off of endocan is 0.7 ng/mL, the rate of cases with endocan level lower than the cutoff was 0% on day 0, 20% on day 21, and 85.7% on day 28. The rate of cases with CRP lower than the normal level was 44.4% on day 28, and the rate of cases with PCT lower level than the cutoff was 60% on day 21. Conclusion: During the treatment of infective endocarditis, serum endocan gradually decreased. By setting the cutoff of endocan, serum endocan could be a useful biomarker for determing the timing of treatment termination in infective endocarditis.

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.

Conjugation and Characterization of Latex Particles with Toxoplasma gondii–specific Immunoglobulin Y Antibodies for Diagnostic Aim and Evaluation Efficiency in In Vitro Culture

Toxoplasma gondii is a parasite that causes severe health problems in the world. Toxoplasmosis, an infection caused by T. gondii, leads to high risk of mortality in patients with immunodeficiency, transplantation, and cancer. Besides that, it causes miscarriages in pregnancy, various abnormalities such as hydrocephalus in infants and congenital diseases. Because the clinical indication of the disease is not specific, it is confused with many diseases, and this leads to the necessity of directly detecting the presence of the toxoplasmosis. Therefore, various diagnostic assays are needed for the diagnosis of the disease. Amongs them, latex agglutination assay is widely used for the detection of specific antibodies or antigens in samples. Latex particles are coated with immunogenic molecules (antigens) to detect antibodies in the blood or used to identify antigens when coated with specific antibodies. In both, aggregation of latex particles results in agglutination. Monoclonal antibodies are often used in latex agglutination assay as in other diagnostic methods. However, monoclonal antibodies can be produced in low quantities at a high cost. Besides, to produce monoclonal antibodies, an experienced staff, a well-equipped cell culture laboratory, a long period of time, and a burdened budget are needed. In recent years, as an alternative to monoclonal antibodies, immunoglobulin Y (IgY) antibodies, which are obtained from chicken eggs, and specifically produced against desired antigenic constructs, have become quite attractive in terms of both low cost and abundant production without requiring infrastructure. In contrast, the latex assay based on IgY antibodies for use in the diagnosis of T. gondii has not been developed. This study aimed to conjugate T. gondii-specific IgY antibodies to latex particles, characterize the particles by Fourier transform infrared spectroscopy, scanning electron microscopy, and spectroscopic methods, and finally demonstrate the interaction with T.gondii parasites in culture with scanning electron microscopy analysis.

Mapping the probability of detecting Burkholderia pseudomallei in rural rice paddy soil based on indicator kriging and spatial soil factor analysis.

Melioidosis is an infectious disease commonly found in Thailand. This infectious disease is caused by Burkholderia pseudomallei in soil. This study aims to analyze the association between spatial soil factors and B. pseudomallei detection, as well as to map the probability of B. pseudomallei contamination based on indicator kriging in paddy soil. Seventy-eight soil samples were collected randomly on 22 April 2018 in various paddy fields. Oxidase, Gram staining and monoclonal antibody-based latex agglutination assays were performed to confirm the presence of B. pseudomallei in soil samples. The association between B. pseudomallei detection and spatial soil factors including soil temperature, soil pH, soil texture and soil drainage were analyzed by the Mann-Whitney U test and χ2 test. Subsequently, a semivariogram model and indicator kriging were used to map the probability of B. pseudomallei contamination. Of the 78 samples, B. pseudomallei was detected in 32 (41.03%). The presence or absence of B. pseudomallei was not significantly associated with spatial soil factors. The semivariogram model showed that the lag distance between positive B. pseudomallei samples was 90.51m. The empirical semivariogram and indicator kriging are an alternative option for predicting the spatial distribution of B. pseudomallei in soil.

Clinico-radiological profile of CVT patients and its correlation with D-dimer

Cerebral Venous Thrombosis (CVT) is a well-known disease with diverse clinical presentation and causes. With advances in neuroimaging and changing lifestyles, the clinical profile and causes of CVT are changing. D-dimer has been studied in early diagnosis of CVT with variable results. This prospective study was carried out to assess the clinical profile of CVT and role of D-dimer in early diagnosis of CVT. The study period was from September 2017 to July 2019 and included 32 imaging proven patients of CVT. We also included 32 patients of migraine for assessing D-dimer. Data was collected according to a preformed format. D-dimer was assessed by a rapid semi-quantitative latex agglutination assay. Out of 32 CVT patients, 16(50%) were females. The mean age of the patients was 31.56 ± 14.31 years. Most common clinical features were headache (96.25%), papilloedema (37.5%) and seizures 10 (31.25%). Puerperium was the most common cause of CVT in females. Superior sagittal and transverse sinuses were the most common sinuses to be affected. The sensitivity of D-dimer assay was 81.25% and specificity 62.5%. Cerebral venous thrombosis is a disease with equal predilection among both genders affecting mostly young individuals. Most of the patients present with headache. Puerperium still contributes to majority of the cases. Iron deficiency anaemia needs to be evaluated as an association for CVT. Positive D-dimer should strengthen the suspicion of CVT in patients with acute headache.

Comparative analysis of rheumatoid factor levels by immune turbidimetry and latex agglutination assays among anti-cyclic citrullinated peptide-positive rheumatoid arthritis patients

Background: Rheumatoid arthritis (RA) is one of the most common contributors to the burden of chronic and debilitating polyarthritis. Materials and Methods: Over a period of 3 months, 264 symptomatic patients were tested for the presence of anti-cyclic citrullinated peptide (CCP) antibodies, and the first 50 patients with RA whose serum samples tested positive for anti-CCP (>10 AU/ml) were included in the study. Immune turbidimetric assay was employed to determine the titers of rheumatoid factor (RF) in patients of RA who have tested positive for anti-CCP and its performance was compared with latex agglutination testing modality. Results: Majority (82%) of the study population were female with a male-to-female ratio of 1:4.6. Latex agglutination test for RF using RHELAX-RF test kit yielded RF values ≥10 IU/ml in 31 (62%) patients, while the Immunoturbidimetric test: SPECTRUM RF Test Kit imparted RF titers ranging between 2.4 and 53.76 IU/ml, with a median RF titer of 22.22 IU/ml. The percentage agreement between the latex agglutination and immune turbidimetry assay for analyzing RF was 88%, with a strong positive correlation between latex agglutination and immune turbidimetry assay for RF (Spearman coefficient: r = 0.8097). Conclusion: Since the updated American College of Rheumatology/European League Against Rheumatism classification of RA underscores the precise titers of RF and anti-CCP in scoring RA, absolute titers of RF conferred by the immunoturbidimetry could be a welcome relief to slash inter-observer variations and hand out titers to better classify and treat patients of RA.

Orostachys japonicus ethyl acetate fraction suppresses MRSA biofilm formation

Objective: To investigate the effect of Orostachys (O.) japonicus, a perennial herbaceous plant of the Family Crassulaceae, on biofilm formed by methicillin-resistant Staphylococcus aureus (MRSA). Methods: Powdered O. japonicus was extracted by 95% methanol, concentrated, and then, systematically fractionated with n-hexane, dichloromethane (DCM), ethyl acetate (EtOAc), n-butanol, and H2O according to polarity. Among them, the flavonoid-rich EtOAc fraction demonstrated the highest antibacterial activity and was used in this study. Using the biofilm inhibition assay, cell-surface attachment assay, confocal laser scanning microscopy, latex agglutination assay, and real time qRT-PCR, we examined whether the EtOAc fraction inhibited the formation of MRSA biofilm. Results: The EtOAc fraction exhibited distinct activity against biofilm formation and cell-surface attachment of MRSA up to 1 mg/mL through down-regulating the expression of mecA gene and the production and agglutination of penicillin-binding protein 2a as solidly observed in biofilm inhibition assay, cell-suface attachment assay, confocal laser scanning microscopy, latex agglutination assay, and real time qRT-PCR analysis. Conclusions: These results suggest that O. japonicus could be utilized as a potential resource for the development of new anti-biofilm formation of MRSA and antibacterial agents in the future.

Contrasting Results from Two Commercial Kits Testing for the Presence of Clostridium perfringens Enterotoxin in Feces from Norovirus-Infected Human Patients.

Detection of Clostridium perfringens enterotoxin (CPE) is critical for disease surveillance; however, commercial testing kits produce contrasting results. We examined the cause of the differing results from a reversed passive latex agglutination (RPLA) assay (PET-RPLA Toxin Detection Kit) and an enzyme-linked immunosorbent assay (C. perfringens Enterotoxin ELISA Kit) using 73 human norovirus-positive fecal samples from gastroenteritis patients across 22 episodes in Japan. CPE was detected in 39/73 samples using the RPLA method; however, ELISA-based examination of 10 RPLA-positive samples produced negative results. Moreover, cpe was not detected in any of the RPLA-positive (n = 32) or -negative (n = 5) samples, and C. perfringens was only isolated from one RPLA-positive sample. An ELISA-based testing approach may be more reliable than RPLA assays for CPE detection from human fecal samples. These findings may also be applicable to the detection of other foodborne diseases.

Toxoplasma gondii seropositivity and the associated risk factors in sheep and pregnant women in El-Minya Governorate, Egypt.

Background and Aim:The cosmopolite protozoan, Toxoplasma gondii, has a significant economic and medical impact. Cats traditionally play a predominant role in the disease maintenance cycle; however, humans can be infected as a result of milk and meat consumption of Toxoplasma-infected livestock. In addition, infected pregnant women, even symptomless, can pass the disease to their unborn fetus. The limited clinical records and absence of specific national educational programs in countries like Egypt underscore the need for periodic toxoplasmosis disease evaluation. Here, we identified T. gondii seroprevalence among sheep and pregnant women and the associated risk factors in El-Minya Governorate, Egypt.Materials and Methods:Using peripheral blood, we detected T. gondii-specific antibodies in 151 sheep and 96 pregnant women sera from El-Minya Governorate using latex agglutination and indirect enzyme-linked immunosorbent assay. The impact of different environmental and behavioral risk factors identified with in-person interviews and serology results on acquiring toxoplasmosis was statistically analyzed.Results:The overall toxoplasmosis seroprevalence was 39.1% and 22.9% in sheep and pregnant women, respectively. Significantly higher seroprevalence was correlated with increasing sheep age and geographical location. Nonetheless, no statistical significance was found based on abortion history and pregnancy status of the examined sheep. Exposure factors important for pregnant women included pregnancy trimester, contact with cats, and the habit of eating undercooked sheep meat, which all had a statistically significant association with Toxoplasma seropositivity.Conclusion:The current study confirms increased antibodies against toxoplasmosis in both sheep and pregnant women in El-Minya Governorate and a clear association between women’s age, contact with cats, and the habit of eating undercooked sheep meat and seroreactivity to T. gondii. These results strongly suggest the need for a more comprehensive epidemiological study and public health awareness education for toxoplasmosis.