Optimization of Formic Acid-Formalin-Based Decalcification Protocol for Rat Calvarial Bone Histology

Decalcification is crucial in histological processing, particularly for studying mineralized tissues like bone. The choice of decalcification method can significantly impact the quality of histological sections and the preservation of tissue morphology. This study aims to establish a standardized protocol for decalcifying rat calvarial bone using a formic acid-formalin-based decalcification solution. The protocol was systematically optimized and evaluated based on various parameters, including decalcification time, formic acid concentration, and tissue integrity preservation. The decalcification process was evaluated through comprehensive assessments, including gross physical examination, chemical analysis, and radiographic imaging techniques. Our result demonstrated that the 10% formic acid concentration proved most effective for decalcifying rat calvarial bone samples within eight days, excelling in mineral content removal while preserving specimen structural integrity. In contrast, the 5% concentration failed to complete decalcification within ten days, and the 15% compromised sample quality within eight days. Histological analyses confirmed the efficacy of the 10% formic acid concentration in maintaining tissue integrity and achieving optimal staining quality. The standardized protocol presented in this study provides an effective and reliable approach for achieving consistent and high-quality histological sections of rat calvarial bone. An ideal decalcification agent should effectively remove calcium salts, preserve structural integrity and molecular components, facilitate rapid yet minimally damaging decalcification, and ensure ease of handling for laboratory personnel. Further exploration of its applicability to different bone types or species is recommended to broaden its research utility

Management of bovine brucellosis in organized dairy herds through the identification of risk factors: A cross-sectional study from Karnataka, India

Background and Aim: Brucellosis is an infectious disease caused by Brucella species. This study aimed to identify the risk factors associated with bovine brucellosis seropositivity in organized dairy farms to control the disease in unvaccinated adult bovine herds in Karnataka, India. Materials and Methods: In total, 3610 samples (3221 cattle and 389 buffaloes) were subjected to parallel testing using the Rose Bengal plate test and protein G-based enzyme-linked immunosorbent assay, followed by analyses of animal- and farm-level epidemiological datasets to identify the risk factors. Results: The apparent brucellosis prevalence at the animal level was higher in buffaloes (8.2%, 95% confidence interval [CI] = 5.9–11.4) than in cattle (6.1%, 95% CI = 5.3–7.0). In a multivariable logistic model, animals calved 3–5 times (odds ratio [OR] = 2.22, 95% CI = 1.50–3.1, reference [ref]: animals calved <2 times); animals with a history of abortion (OR = 54.73, 95% CI = 33.66–89.02), repeat breeding (OR = 19.46, 95% CI = 11.72–32.25), and placental retention (OR = 13.94, 95% CI = 4.92–39.42, ref: no clinical signs); and dogs on farms (OR = 2.55, 95% CI = 1.48–4.40, ref: absence of dogs); disposal of aborted fetus in open fields (OR = 4.97, 95% CI = 1.93–12.84) and water bodies (OR = 2.22, 95% CI = 1.50–3.1, ref: buried); purchase of animals from other farms (OR = 6.46, 95% CI = 1.01–41.67, ref: government farms); hand milking (OR = 1.98, 95% CI = 1.02–10.0, ref: machine milking); and use of monthly veterinary services (OR = 3.45, 95% CI = 1.28–9.29, ref: weekly services) were considered significant risk factors for brucellosis in organized bovine herds (p < 0.01). Conclusion: The study identified that the animals calved 3–5 times or with a history of abortion/repeat breeding/placental retention, and disposal of aborted fetus in open fields/water bodies as the potential risk factors for bovine brucellosis. These risk factors should be controlled through the implementation of best practices to reduce the brucellosis burden in bovine farms

Antimicrobial resistance pattern of extended-spectrum β-lactamase-producing Escherichia coli isolated from fecal samples of piglets and pig farm workers of selected organized farms of India

Background and Aim: Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli are gradually increasing worldwide and carry a serious public threat. This study aimed to determine the antimicrobial resistance pattern of ESBL-producing E. coli isolated from fecal samples of piglets and pig farm workers. Materials and Methods: Fecal samples from <3-month-old piglets (n=156) and farm workers (n=21) were processed for the isolation of ESBL-producing E. coli in MacConkey agar added with 1 μg/mL of cefotaxime. E. coli (piglets=124; farm workers=21) were tested for ESBL production by combined disk method and ESBL E-strip test. Each of the ESBL-positive isolate was subjected to antibiotic susceptibility testing. The ESBL-producing E. coli were further processed for genotypic confirmation to CTX-M gene. Results: A total of 55 (44.4%, 55/124) and nine (42.9%, 9/21) ESBL-producing E. coli were isolated from piglets and farm workers, respectively. Antibiotic susceptibility testing of the ESBL-positive E. coli isolates from piglets and farm workers showed 100% resistance to ceftazidime, cefotaxime, cefotaxime/clavulanic acid, ceftazidime/clavulanic acid, and cefpodoxime. A proportion of 100% (55/55) and 88.9% (8/9) ESBL-positive E. coli were multidrug resistance (MDR) in piglets and farm workers, respectively. On genotypic screening of the ESBL E. coli isolated from piglets (n=55), 15 were positive for the blaCTX-M gene and of the nine ESBL E. coli from farm workers, none were positive for the blaCTX-M gene. Conclusion: Although there was no significant difference in isolation of ESBL-producing E. coli between piglets and farm workers, the ESBL-positive E. coli from piglets showed relatively higher MDR than farm workers

Global Status of COVID-19 Diagnosis: An Overview

Since the beginning of the New Year 2020, countries around the world are stumbling due to the coronavirus disease (COVID-19) pandemic. Better approaches of diagnostics and medical facilities have helped some countries recover early. Previous exposures to epidemics have imparted lessons to handle such a pandemic with a high level of preparedness. The World Health Organization (WHO) and national health authorities are taking great efforts via efficient and impactful interventions to contain the virus. Diagnostic tests such as reverse transcription-polymerase chain reaction are increasingly being used to confirm the diagnosis because testing biological samples for the presence of the virus is the definitive method to identify the disease, analyze the risk for transmission, and determine whether someone has been cured or not. It is also important to screen asymptomatic individuals to get the exact overview of the virus spread. Antibody detection plays a pivotal role in diagnosis; however, using it at the wrong time yields negative results and conveys dissenting opinion about the tests. Although the scaling up of testing has been significant, overall testing has been limited by the availability of diagnostics. Rapid diagnoses and discontinuation of transmission are keys to ending this pandemic. Diagnostics manufacturers are developing test kits and distributing them to different countries. Therefore, more than 500 commercial test kits for molecular- and immunoassays, most with Emergency Use Authorization, are now becoming available in the market. In this review, we discuss the importance of diagnostics, approaches of different countries toward the epidemic, global testing situation, and lessons to countries at the start of the epidemic for better preparedness