Development of a latex agglutination test based on VH antibody fragment for detection of Streptococcus suis serotype 2.

Streptococcus suis serotype 2 (SS2) is an important porcine pathogen that causes diseases in both swine and human. For rapid SS2 identification, a novel latex agglutination test (LAT) based on heavy-chain variable domain antibody (VH) was developed. Firstly, the soluble 47B3 VH antibody fragment from a phage display library, in which cysteine residues were engineered at the C-terminus, was expressed in Escherichia coli. The purified protein was then gently reduced to form monomeric soluble 47B3 VH subsequently used to coat with latex beads by means of site-specific conjugation. The resulting VH-coated beads gave a good agglutination reaction with SS2. The LAT was able to distinguish S. suis serotype 2 from serotype 1/2, which shares some common sugar residues, and showed no cross-reaction with other serotypes of S. suis or other related bacteria. The detection sensitivity was found to be as high as 1.85x106 cells. The LAT was stable at 4°C for at least six months without loss of activity. To the best of our knowledge, this is the first LAT based on a VH antibody fragment that can be considered as an alternative for conventional antibody-based LAT where VHs are the most favored recombinant antibody.

Measurement of serum hepcidin-25 by latex agglutination in healthy volunteers and patients with hematologic disorders.

Iron is an essential trace metal, vital for various physiologic processes, but excess levels can harm health. Maintaining iron homeostasis is critical, with hepcidin playing a key role. The isoform hepcidin-25 exerts the most significant influence on iron metabolism, making its serum levels a valuable diagnostic tool. However, mass-spectrometry and other conventional measurement methods can be difficult to perform, and some immunoassays lack reliability. In this study, we employed a recently developed latex agglutination method integrated with a readily available automated analyzer to quantify serum hepcidin-25 levels in both volunteers recruited from personnel of our hospital (n = 93) and patients with various hematological disorders (n = 112). Our findings unveiled a robust positive correlation between serum hepcidin-25 and ferritin, as well as C-reactive protein levels, in both volunteers and patients. Among the patients with hematological disorders, there was a noteworthy negative correlation between hepcidin-25 levels and hemoglobin concentrations, as well as reticulocyte counts. Interestingly, the hepcidin-25/ferritin ratio was remarkably low in patients with hemolytic anemia and myelodysplastic syndromes with ring sideroblasts. Our findings suggest that quantifying serum hepcidin-25 and the hepcidin-25/ferritin ratio using this method may be valuable for screening of hematopoietic diseases and other iron metabolism disorders.

Utilization of an Automated Latex Agglutination Turbidity Assay for Assessing Gastric Mucosal Alteration during Helicobacter pylori Infection.

Background/Aims: : A latex agglutination turbidity (LA) assay to test for serum antibodies has been approved in Japan and Korea for mass screening of Helicobacter pylori infection. In this study, we evaluated the LA assay for diagnosing H. pylori infection and predicting gastric mucosal changes in a Mongolian population. Methods: : In total, 484 individuals were classified into H. pylori-positive (n=356) and H. pylori-negative (n=128) groups, as determined by histology and H. pylori culture. Results: : The best cutoff, sensitivity, and specificity values for the LA assay were 18.35 U/mL, 74.2%, and 65.6%, respectively. The LA values in the atrophic gastritis group were statistically higher than those in the other groups (healthy, chronic gastritis, intestinal metaplasia, and gastric cancer, p<0.0001). The cutoff value to distinguish the atrophic gastritis group from the other four groups was 32.0 U/mL, and its area under the curve was 0.673, which was the highest among the E-plate, pepsinogen (PG) I, PG II, and PG I/II ratio tests in our data. The odds ratios for atrophic gastritis determined by the LA assay and PG I test in multiple logistic regression were 2.5 and 1.9, respectively, which were significantly higher than for the other tests. Conclusions: : The LA assay can determine the risk of atrophic gastritis, which in turn is a considerable risk factor for gastric cancer. We propose using this assay in combination with the PG I/II ratio to avoid missing gastric cancer patients who have a low LA value (less than 32.0 U/mL).

An efficient and convenient Fiber -2- based latex agglutination test for the detection of antibodies against fowl adenovirus serotype 4 in clinical samples.

To detect the antibody against fowl adenovirus serotype 4 (FAdV-4) in clinical practice, the latex agglutination test (LAT) was developed by using the Fiber-2 protein of FAdV-4 as an antigen bound to sensitized latex microspheres. The concentration, time, and temperature of sensitization latex microspheres by the Fiber-2 protein were studied and optimized; the specificity, sensitivity, and repeatability of LAT were tested; and the method developed in the study was applied. The results showed that the optimum sensitization concentration of Fiber-2 protein was 0.8 mg/mL, the time was 120 min, and the temperature was 37 â„ƒ. Except for antiserum against FAdV-4 and FAdV-10, LAT developed in the study could not agglutinate antisera against FAdV-1, FAdV-2, FAdV-3, FAdV-4, FAdV-5, FAdV-6, FAdV-8a, FAdV-8b, FAdV-11, Newcastle disease virus, infectious bronchitis virus, egg drop syndrome virus and Clostridium perfringens. Compared with the commercial FAdV-4 ELISA Kit, the titers in 21 clinical samples were low when tested by the developed LAT method, but there was no significant difference. The coefficients of variation among different batches and the same batch of latex-sensitized particles were between 0 % and 13.3 % and 0-8.7 %, respectively. The critical value of immune protective antibody against FAdV-4 was 25, and the titers in 40.9 % of clinical samples were higher than the immune critical point. The results showed that the Fiber-2-based LAT developed in the study has the characteristics of high specificity, sensitivity and repeatability, has the advantages of free equipment, long shelf life, and fast and easy operation, and is an effective and convenient method for serological diagnosis of FAdV-4 infection and evaluating the efficacy of vaccines.

Comparative analysis of diagnostic methods for the detection of Cryptococcus neoformans meningitis.

BACKGROUND: Cryptococcosis is a devastating opportunistic infection in immunocompromised individuals, primarily in people living with HIV/AIDS. This study evaluated a protocol for the early diagnosis of meningitis due to C. neoformans, utilizing established molecular techniques from serum and CSF samples. METHODS: The 18S and 5.8S (rDNA-ITS) sequence-specific nested PCR assays were compared with direct India ink staining and the latex agglutination test for detection of C. neoformans in serum and cerebrospinal fluid (CSF) from 49 Brazilian suspected meningitis patients. Results were validated with samples obtained from 10 patients negative for cryptococcosis and HIV, and by analysis of standard C. neoformans strains. PRINCIPAL FINDINGS: The 5.8S DNA-ITS PCR was more sensitive (89-100%) and specific (100%) than the 18S rDNA PCR and conventional tests (India ink staining and latex agglutination) for identification of C. neoformans. While the 18S PCR exhibited a sensitivity (72%) similar to that of the latex agglutination assay in serum samples, it was superior to the latex agglutination assay when testing CSF, with a sensitivity of 84%. However, the latex agglutination was superior to the 18SrDNA PCR in specificity in CSF (92%). The 5.8S DNA-ITS PCR yielded the highest levels of accuracy (96-100%) of any test for detection (serological and mycological) of C. neoformans in both serum and CSF. CONCLUSION: Use of the nested 5.8S PCR was superior to other techniques for the diagnosis of cryptococcosis. The possibility of using serum, a non-invasively collected material, in a targeted 5.8S PCR analysis to identify Cryptococcus spp. is recommended, especially in immunosuppressed patients. Our results indicate that nested 5.8S PCR can increase the diagnostic capability of cryptococcosis, and we suggest its use to monitor patients in the future.

Staphylococcal aureus bacteraemia: Clinical characteristic & evaluation of Prolex Staph Xtra latex agglutination test in the rapid identification of Staphylococcus aureus.

BACKGROUND: Staphylococcus aureus is a leading cause of community as well as healthcare-associated bacteraemia. This study aimed to describe clinical characteristics of S. aureus bacteraemia (SAB) and to evaluate the performance of the Prolex Staph Xtra Latex agglutination test in the identification of Staphylococcus aureus. METHODS: Cross-sectional study was conducted from Jun 2018 to May 2019. Isolates from first-positive peripheral blood cultures were tested with Prolex Staph Xtra Latex agglutination test, together with routine tube coagulase and DNase test. All isolates were further confirmed with Vitek2 GP. RESULTS: Hundred isolates were tested with Prolex Staph Xtra Latex. Twelve isolates were excluded due to incomplete medical records. Eighty-eight isolates were analysed, yielded sensitivities, specificities, positive and negative predictive values of 100%, 91.7%, 98.7%, and 100%, respectively. Of these, 76 were identified as S. aureus and 12 CoNS. Seventy-six patients were included in the SAB analysis. Fifty-nine out of 76 (78.6%) had underlying comorbidities. Thirty-four percent of the episodes were considered as primary SAB. Skin and soft tissue infection were accounted for the highest source of bacteraemia, 24(31.6%). Both MRSA and MSSA bacteraemia were seen mostly among healthcare-associated bacteraemia (HCA) (7/16, 43.8% and 28/60, 46.7%). Liver cirrhosis was significantly associated with MRSA bacteraemia (P=0.048). Metastatic infection & complicated SAB were identified in 13(17.1%) and 30(39.5%) of cases, respectively. All-cause mortality was 22.4%. CONCLUSION: S. aureus bacteraemia is a serious infection associated with significant metastatic complications and mortality. Prolex Staph Xtra Latex agglutination test has excellent sensitivity and specificity with 100% and 91.7% respectively.

An infantile late-onset case Group of B Streptococcus meningitis diagnosed with a rapid latex kit.

Globally, vaccination has reduced the prevalence of meningitis caused by Streptococcus pneumoniae Neisseria meningitidis, and Haemophilus influenzae. However, neonatal Group B Streptococcus (GBS) meningitis continues to remain a problematic infection of the central nervous system. Here, we report a case of bacterial meningitis in a 34-day old male baby who presented with fever. A cerebrospinal fluid (CSF) test on the day of admission showed an increase in cell count with decreased glucose level. A rapid latex test of the CSF using a commercial kit diagnosed the causative pathogen as GBS. We administered the antibiotics ampicillin, cefotaxime, gentamicin and panipenem/betamipron to the patient for over 14 days. Partial seizures were frequently observed during the course and were well-controlled with midazolam and phenobarbital. Brain magnetic resonance imaging on day 17 showed subdural hygroma in the frontal region, and 99mTc ethyl-cysteinate dimer-single photon emission computed tomography confirmed a decreased cerebral blood flow predominantly in the left frontal region. After three years of follow-up, the condition of the patient improved without any neurological sequelae. Our report highlights that rapid identification of the causative organism is essential in infantile late-onset meningitis. In addition, we consider that the latex kit-based rapid testing of CSF is beneficial for identifying the causative agent of bacterial meningitis.

Study on prevalence and liver function test enzymes of differently plumaged peafowls (Pavo cristatus) infected with Toxoplasma gondii in captivity / [Estudo sobre enzimas de prevalência e teste da função hepatica de pavões de plumage diferente (Pavo cristatus) infectados com Toxoplasma gondii em cativeiro]

O presente estudo foi realizado para determinar a prevalência geral de toxoplasmose em pavões de plumagem diferente e seu efeito nas enzimas de teste da função hepática dos hospedeiros. Um total de cem pavões de plumas diferenciais, como ombro preto (n = 52), azul (n = 28), branco (n = 10) e arlequim (n = 10) foram estudados no zoológico de Bahawalpur, no Paquistão, usando o Latex Agglutination Test (LAT) e ensaio imunossorvente ligado a enzima (ELISA). A prevalência geral por LAT e ELISA foi de 37% e 30%, respectivamente. Por LAT, observou-se uma prevalência não significativamente maior (P≥0,05) em gênero (37,77%) nos machos do que nas fêmeas (36,36%), enquanto os adultos apresentaram uma prevalência maior (37,97%) em relação aos jovens (33,33%). De acordo com o ELISA, uma prevalência significativamente (P <0,05) maior (35,55%) foi observada nos machos do que nas fêmeas (25,45%) e significativamente (P <0,05) maior prevalência (31,64%) foi registrada nos adultos do que nos jovens (23,80%). A análise do perfil bioquímico sérico mostrou que o nível de bilirrubina não teve elevação significativa nos hospedeiros infectados, em comparação aos não infectados, enquanto a concentração de albumina, alanina aminotransferase (ALT), aspartato aminotransferase (AST), fosfatase alcalina (ALP) foi significativamente (P <0,05) diferente nos hospedeiros infectados. Conclui-se que a toxoplasmose afeta as enzimas do teste da função hepática. Essa é uma pesquisa preliminar e requer mais pesquisas em todo o país, com populações e amostras maiores.(AU)

Serum Helicobacter pylori antibody reactivity in seven Asian countries using an automated latex aggregation turbidity assay.

BACKGROUND AND AIM: To determine the application range of diagnostic kits utilizing anti-Helicobacter pylori antibody, we tested a newly developed latex aggregation turbidity assay (latex) and a conventional enzyme-linked immunosorbent assay (E-plate), both containing Japanese H. pylori protein lysates as antigens, using sera from seven Asian countries. METHODS: Serum samples (1797) were obtained, and standard H. pylori infection status and atrophy status were determined by culture and histology (immunohistochemistry) using gastric biopsy samples from the same individuals. The two tests (enzyme-linked immunosorbent assay and latex) were applied, and receiver operating characteristics analysis was performed. RESULTS: Area under the curve (AUC) from the receiver operating characteristic of E-plate and latex curves were almost the same and the highest in Vietnam. The latex AUC was slightly lower than the E-plate AUC in other countries, and the difference became statistically significant in Myanmar and then Bangladesh as the lowest. To consider past infection cases, atrophy was additionally evaluated. Most of the AUCs decreased using this atrophy-evaluated status; however, the difference between the two kits was not significant in each country, but the latex AUC was better using all samples. Practical cut-off values were 3.0 U/mL in the E-test and 3.5 U/mL in the latex test, to avoid missing gastric cancer patients to the greatest extent possible. CONCLUSIONS: The kits were applicable in all countries, but new kits using regional H. pylori strains are recommended for Myanmar and Bangladesh. Use of a cut-off value lower than the best cut-off value is essential for screening gastric cancer patients.

A novel site-specific chemical conjugation of IgG antibodies by affinity peptide for immunoassays.

Recently, there has been an increasing interest in site-specific modifications of antibodies used in immunoassays for disease diagnosis and as antibody therapeutics, such as antibody-drug conjugates. Previously, we established a site-specific chemical conjugation system using an IgG-Fc binding chemical conjugation affinity peptide (CCAP). CCAP could be used only for the modification of human IgG owing to the lack of affinity of CCAP to rodent IgG molecules. In this study, novel CCAP reagents are proposed, which can be used for both human and mouse IgG, based on the Staphylococcus aureus protein A domain-derived affinity peptides Z34C and Z33. Compared with the activity of a conventional randomly modified antibody, mouse IgG modified using this method had favourable features in two immunoassays, demonstrating the advantages of the proposed CCAP method in preserving antibody functionality during conjugation.

Production of a latex agglutination reagent for the rapid diagnosis of cryptococcal meningitis / Producción de un reactivo de látex para el diagnóstico rápido de criptococosismeníngea

Abstract Cryptococcosis is a fungal disease affecting more than one million people per yearworldwide. Its main etiological agents are Cryptococcus neoformans species complex and Cryp-tococcus gattii species complex. Cryptococcal meningitis (CM) is considered an AIDS-definingcondition. Rapid diagnosis by cryptococcal antigen assays, either the latex agglutination test(LA) or the lateral flow assay, is key to decreasing mortality due to cryptococcal disease. Theaim of the study was to develop a latex agglutination reagent (LA-ANLIS) for the rapid and reliable diagnosis of cryptococcosis in Argentina. This reagent will be produced in order to supplythe NMLN (National Mycology Laboratory Network). The evaluation of LA-ANLIS performanceand its comparison with the Cryptococcus Antigen Latex Agglutination Test System (LA-IMMY)(Immuno-Mycologics, Inc., USA) were conducted in 94 samples of cerebrospinal fluid. LA-ANLISand LA-IMMY compared exhibited 100% positive agreement and 97% negative agreement. LA-ANLIS showed 94% sensitivity and 97% specificity with the positive and negative predictivevalues of 94% and 97%, respectively. The LA-ANLIS is a reliable, reproducible and cost-effectivereagent, especially useful in countries where the commercial kit is not generally available andmust be obtained at a high cost. National production of reagents is the best choice for a reliableaccess to the rapid diagnosis of CM in Argentina.

Resumen La criptococosis es una enfermedad fúngica que afecta a más de un millón de personas por año en todo el mundo. Los principales agentes etiológicos pertenecen a los complejos de especies Cryptococcus neoformans y Cryptococcus gattii. La criptococosis meníngea (CM) se considera una enfermedad marcadora de sida. El diagnóstico rápido de esta enfermedad a través de la detección del antígeno de Cryptococcus, ya sea por aglutinación en partículas de látex o por inmunocromatografía, es clave para disminuir la mortalidad. El objetivo del presente estudio fue desarrollar un reactivo de aglutinación en partículas de látex para el diagnóstico rápido y certero de la CM en Argentina. Este reactivo (denominado en adelante LA-ANLIS) será producido para abastecer a la Red Nacional de Laboratorios de Micología. Se evaluó el desempeno del reactivo LA-ANLIS, y se realizó una comparación con el reactivo comercial Immuno-Mycologics, Inc. (en adelante, LA-IMMY) utilizando 94 muestras de líquido cefalorraquídeo. Hubo un 100% de acuerdo positivo y un 97% de acuerdo negativo entre los resultados obtenidos con los reactivos LA-ANLIS y LA-IMMY. El reactivo LA-ANLIS mostró una sensibilidad del 94% y una especificidad del 97%; los valores predictivos positivo y negativo fueron del 94 y del 97%, respectivamente. Se concluye que el LA-ANLIS es un reactivo confiable y rentable, que arroja resultados reproducibles, por lo que es especialmente útil en países donde los reactivos comerciales generalmente no están disponibles o sus costos son elevados. La producción nacional de reactivos es la mejor opción para asegurar el acceso de todos los hospitales al diagnóstico rápido de la CM en Argentina.

Performance of the Lateral Flow Assay and the Latex Agglutination Serum Cryptococcal Antigen Test in Cryptococcal Disease in Patients with and without HIV.

Cryptococcal epidemiology is shifting toward HIV-negative populations who have diverse presentations. Cryptococcal antigen (CrAg) testing is also changing, with development of the lateral flow assay (LFA) having reported increased sensitivity and specificity, but with minimal knowledge in the HIV-negative population. In this study, we evaluate the real-life performance of CrAg testing in patients with cryptococcal disease. We conducted a retrospective review of patients with cryptococcosis from 2002 to 2019 at Barnes-Jewish Hospital. Latex agglutination (LA) was used exclusively until April 2016, at which point LFA was used exclusively. Demographics, presentations, and testing outcomes were evaluated. Serum CrAg testing was completed in 227 patients with cryptococcosis. Of 141 HIV-negative patients, 107 had LA testing and 34 had LFA testing. In patients with disseminated disease, serum CrAg sensitivity by LA was 78.1% compared to 82.6% for LFA. In patients with localized pulmonary disease, serum CrAg sensitivity was 23.5% compared to 90.9% for LFA. Of 86 people living with HIV (PLWH), 76 had LA testing, and 10 had LFA testing. Serum CrAg sensitivity for LA was 94.7% compared to 100% for LFA in patients with disseminated disease. We noted a significant improvement in sensitivity from LA testing to LFA testing, predominantly in those with localized pulmonary disease. However, both LFA and LA appear to be less sensitive in HIV-negative patients than previously described in PLWH.

Inflammatory markers in saliva for diagnosis of sepsis of hospitalizes patients.

BACKGROUND: Inflammatory/immunological serum markers are useful for the early detection of organ dysfunction, helping the diagnosis of sepsis. Although the detection of blood biomarkers is a standard practice, the use of noninvasive samples (eg saliva) would be beneficial. AIM: To investigate the saliva of hospitalized patients with and without sepsis and identify the levels of inflammatory markers such as C-reactive protein (CRP), procalcitonin (PCT), interleukin 6 (IL-6) and nitric oxide (NO). METHODS: Saliva samples were collected from 26 patients in intensive care unit with diagnosis of sepsis and from 26 without sepsis (control). The levels of CRP were determined by using latex agglutination test, whereas those of procalcitonin and IL-6 by ELISA and NO by the Griess reaction. RESULTS: Of 26 patients with sepsis, 14 were males (54%) with a mean age of 63.81 ± 3.48 years. The control group had the same distribution for gender, with mean age 65.04 ± 4.07 years. Sepsis group showed higher salivary concentrations of CRP, PCT, IL-6 and NO, with only levels of IL-6 being statistically different (P = .0001). CONCLUSIONS: Patients with sepsis had significantly higher levels of IL-6 in their saliva, suggesting that this biological sample could be useful in the diagnosis of this condition.

Comparison of two new in-house Latex Agglutination Tests (LATs), based on the DnaK and Com1 synthetic peptides of Coxiella burnetii, with a commercial indirect-ELISA, for sero-screening of coxiellosis in bovines.

The in-house developed DnaK and Com1 synthetic peptide-based Latex Agglutination Tests (LATs) were comparatively evaluated with commercial indirect-ELISA kit, to provide a rapid, economical and onsite field applicable test for seroscreening of coxiellosis in bovines.

Evaluation of a commercial latex agglutination test for detecting rotavirus A and human adenovirus in children's stool specimens.

OBJECTIVES: Rotavirus A and human adenovirus are the two most common causes of infantile diarrhea; thus, it is of great importance to find out a rapid and accurate diagnostic method. This study aimed to evaluate the diagnostic significance of latex agglutination test for detection of rotavirus A and human adenovirus. METHODS: A prospective study was conducted on 214 diarrhea children from September 2018 to March 2019 in our hospital. Fresh stool samples were collected for detection of rotavirus A and human adenovirus by latex agglutination test and quantitative reverse transcription polymerase chain reaction (RT-qPCR). Then, the consistency of results detected by these two methods was analyzed． RESULTS: With performing the latex agglutination test, it was revealed that positive rates for detecting rotavirus A virus and human adenovirus were 23.83% (51/214) and 25.24% (54/214), respectively. Meanwhile, results of RT-qPCR showed that positive rates for detecting rotavirus A virus and human adenovirus were 58 (27.10%) and 59 (27.57%), respectively. Using RT-qPCR as the gold standard, the sensitivity and specificity of the latex agglutination test for detecting rotavirus A were 81.03% and 97.44%, and the corresponding values for detecting human adenovirus were 76.27% and 94.19%, respectively. CONCLUSION: This latex agglutination test showed a satisfactory consistency with RT-qPCR for detecting rotavirus A and human adenovirus. The mentioned commercial assay may be highly appropriate for rapid screening of rotavirus A and human adenovirus.

Production of a latex agglutination reagent for the rapid diagnosis of cryptococcal meningitis.

Cryptococcosis is a fungal disease affecting more than one million people per year worldwide. Its main etiological agents are Cryptococcus neoformans species complex and Cryptococcus gattii species complex. Cryptococcal meningitis (CM) is considered an AIDS-defining condition. Rapid diagnosis by cryptococcal antigen assays, either the latex agglutination test (LA) or the lateral flow assay, is key to decreasing mortality due to cryptococcal disease. The aim of the study was to develop a latex agglutination reagent (LA-ANLIS) for the rapid and reliable diagnosis of cryptococcosis in Argentina. This reagent will be produced in order to supply the NMLN (National Mycology Laboratory Network). The evaluation of LA-ANLIS performance and its comparison with the Cryptococcus Antigen Latex Agglutination Test System (LA-IMMY) (Immuno-Mycologics, Inc., USA) were conducted in 94 samples of cerebrospinal fluid. LA-ANLIS and LA-IMMY compared exhibited 100% positive agreement and 97% negative agreement. LA-ANLIS showed 94% sensitivity and 97% specificity with the positive and negative predictive values of 94% and 97%, respectively. The LA-ANLIS is a reliable, reproducible and cost-effective reagent, especially useful in countries where the commercial kit is not generally available and must be obtained at a high cost. National production of reagents is the best choice for a reliable access to the rapid diagnosis of CM in Argentina.

Point of care testing evaluation of lateral flow immunoassay for diagnosis of cryptococcus meningitis in HIV-positive patients at an urban hospital in Nairobi, Kenya, 2017.

OBJECTIVES: The objective of this study was to evaluate the performance of lateral flow immunoassay (LFA) against latex agglutination (LA), India ink and culture in point-of-care diagnosis of cryptococcus meningitis (CM). We conducted cross-sectional study among HIV-positive patients with suspected CM at Mbagathi Hospital, Nairobi, April-July 2017. RESULTS: Of 124 capillary blood and serum and 99 cerebrospinal fluid (CSF) samples, LFA and LA had a concurrence on serum of 94.4%, kappa (0.88), sensitivity (100%) and specificity (91%). LFA and LA on CSF, was 97.9%, kappa (0.96), sensitivity (100%) and specificity (96%). LFA and India ink was 96.9%, kappa (0.94), sensitivity (100%) and specificity (94.1%). On CSF culture, concurrence was 72.7%, kappa (0.43), sensitivity (100%) and specificity (64%) and of LFA on capillary blood, serum and CSF was 100% with kappa (1.00), sensitivity and specificity of 100%.

Development of the Com1 synthetic peptide-based Latex Agglutination Test (LAT) and its comparative evaluation with commercial indirect-ELISA for sero-screening of coxiellosis in cattle.

A novel Com1 synthetic peptide-based latex agglutination test (LAT) was developed and evaluated against commercial ELISA kit for sero-screening of coxiellosis in cattle. The developed test is economical, has field applicability and can serve as an important rapid tool for sero-screening of coxiellosis in cattle.

Evaluation of new algorithm using TPLA as an initial syphilis screening test.

We retrospectively compared the performance of an existing syphilis diagnostic algorithm with a new algorithm that analyzes the results of Treponema pallidum latex agglutination (TPLA) tests. Of the 100 clinical blood samples, 51 were classified as positive through both Mediace TPLA and ESPLINE TP; 2/51 were classified as negative by Architect Syphilis TP, whereas 1/51 was negative as per LUMIPULSE Presto TP. The false positive rate when the results of Mediace TPLA and ESPLINE TP were combined was 1.96% versus 0% for both Architect Syphilis TP and LUMIPULSE Presto TP. The sensitivity of Mediace TPLA (98%) was comparable to that of Architect Syphilis TP (98%) but lower than that of LUMIPULSE Presto TP (100%). The specificity of Mediace TPLA was 98.0% versus 100% for Architect Syphilis TP, and versus 100% for LUMIPULSE Presto TP. We conclude that the performance of Mediace TPLA in combination with a reverse algorithm is nearly equal to that of enzyme immunoassay (EIA) or chemiluminescence immunoassay (CIA). Because TPLA is low cost, highly sensitive method for IgM detection, and is easy to operate, we have recommended its adoption for initial syphilis screening tests.

Antigen Detection in Urine for Noninvasive Diagnosis and Treatment Monitoring of Visceral Leishmaniasis in Human Immunodeficiency Virus Coinfected Patients: An Exploratory Analysis from Ethiopia.

Diagnosis of visceral leishmaniasis (VL) and assessment of treatment response in human immunodeficiency virus (HIV)-coinfected patients still relies on invasive tissue aspiration. This hampers scale-up and decentralization of care in resource-limited settings. Noninvasive diagnostics are urgently needed. KATEX is a frequently used latex agglutination test for Leishmania antigen in urine that has never been evaluated in HIV-coinfected individuals from Leishmania donovani-endemic areas. This was an exploratory sub-study embedded within the screening phase of a trial in highly endemic northwestern Ethiopia. All patients were HIV-positive and aspirate-confirmed VL cases. We assessed diagnostic accuracy of KATEX for VL diagnosis and as test of cure at end of treatment, using tissue aspirate parasite load as reference methods. We also described the evolution of weekly antigen levels during treatment. Most of the 87 included patients were male (84, 97%), young (median age 31 years), and had poor immune status (median cluster of differentiation type 4 count 56 cells/µL). KATEX had moderate sensitivity (84%) for VL diagnosis. KATEX had moderate sensitivity (82%) and a moderate negative predictive value (87%) but only low specificity (49%) and a low positive predictive value (40%) for the assessment of treatment outcomes. Weekly antigen levels showed characteristic patterns during treatment of patients with different initial parasite loads and treatment outcomes. Antigen detection in urine using KATEX can contribute to improved VL diagnosis in HIV-coinfected patients but has limited use for monitoring of treatment response. Better noninvasive diagnostics are needed to reduce reliance on invasive methods and thus to expand and improve clinical care for VL in resource-limited settings.