19th Seminar on Tropical Pathology and Public Health 12th Biotechnology Week 1st Physical Therapy Week, Virtual, 23-25 November 2022

These proceedings comprise 85 articles spanning diverse fields such as bacteriology, molecular biology, biotechnology, dermatology, infectious and parasitic diseases, epidemiology, physiotherapy, immunology, mycology, parasitology, pathology, collective health, and virology. The articles delve into a wide range of research topics, from repurposing drugs for Mycobacterium abscessus complex infections to utilising artificial intelligence for SARS-CoV-2 diagnosis. In bacteriology, investigations explore the correlation between smoking and Helicobacter pylori infection in gastric adenocarcinoma patients, as well as the resistance profiles of Staphylococcus aureus and Pseudomonas aeruginosa in tracheostomised children. Molecular biology studies focus on gene polymorphisms related to diseases like paracoccidioidomycosis. Biotechnology research emphasises bioactive molecules in species like Croton urucurana and the development of computational models for cytotoxicity prediction. Dermatology articles address stability characterisation in vegetable oil-based nanoemulsions. The section on infectious and parasitic diseases encompasses studies on COVID-19 vaccine response in pregnant women and the impact of infection prevention measures in rehabilitation hospitals. Epidemiology investigations analyse trends in premature mortality, tuberculosis in diabetic patients, and public adherence to non-pharmacological COVID-19 measures. Physiotherapy research covers topics such as telerehabilitation through a developed game and the prevalence of congenital anomalies. Immunology studies explore immune responses in HIV and Leishmaniasis, whilst mycology investigates the biotechnological potential of fungi from the cerrado biome. Parasitology research evaluates treatment efficacy against vectors parasites such as Aedes aegypti and Toxoplasma gondii. Pathology articles discuss intentional intoxication in cattle and the influence of curcumin on acute kidney injury therapy. Collective health studies focus on intervention plan development in healthcare settings and pesticide use in horticulture. Lastly, virology research investigates parvovirus occurrence in hospitalised children during the COVID-19 pandemic, hidden hepatitis B virus infection in inmates, and the prevalence of HPV and HTLV-1/2 infections in specific populations.

GATA2 deficiency presenting as fever and rash

Case Report: Our patient is an 8-year-old Caucasian female with a history of choanal atresia, first degree heart block, recurrent urinary tract infections, and recent COVID-19 infection, who initially presented with an episode of syncope and vomiting. By history, she had two weeks of daily fever and an intermittent nonspecific rash. She was diagnosed with a UTI 5 days prior to presentation but had not defervesced despite treatment. Shewas initially found to be in shock with tachycardia and poor perfusion and was treated with fluid resuscitation, antipyretics, and empiric antibiotics. Labs were significant for leukopenia, elevated inflammatory markers, lactic acidosis, coagulopathy, and mildly elevated troponin. Chest x-ray showed abnormal but non-specific widespread infiltrates. She was initially treated with IVIG and pulse steroids for a working diagnosis of MIS-C, however she did not improve and a more extensive infectious, oncologic, and rheumatologic work-up was performed. Her workup revealed a disseminated Mycobacterium abscessus infection. Bone marrow biopsy revealed myelodysplasia with monosomy 7. Her buccal swab testing revealed a heterozygous germline mutation in the GATA2 gene, a variant that is predicted to cause loss of normal protein function. She is presently on multidrug regimen for her mycobacterial infection. Her myelodysplasia evolved into an acute leukemia, and she is undergoing chemotherapy for that at this time. Discussion(s): GATA2 deficiency, first identified in 2011, is a rare immune disorder resulting in a wide variety of clinical presentations. It is caused by a germline mutation of the GATA2 gene that disrupts blood cell differentiation, resulting in decreased or absent monocytes, B cells, NK cells, and dendritic cells1. This case presented multiple challenges due to the broad range of differential diagnoses. This patient was ultimately diagnosed with myelodysplastic syndrome associated with monosomy 7 and GATA2 deficiency, confirmed by FISH testing. Due to the presentation and lab derangements this patient had, there was a delay in targeted treatment while managing her cytopenias and presumed pulmonary infection. GATA2 deficiency carries a high risk of progression from myelodysplastic syndrome to acute myelogenous leukemia. The best long-term treatment for GATA2 deficiency is hematopoietic stem cell transplant, which is the ultimate goal for our patient. Copyright © 2023 Southern Society for Clinical Investigation.

Cysteamine/Cystamine Exert Anti-Mycobacterium abscessus Activity Alone or in Combination with Amikacin.

Host-directed therapies are emerging as a promising tool in the curing of difficult-to-treat infections, such as those caused by drug-resistant bacteria. In this study, we aim to test the potential activity of the FDA- and EMA-approved drugs cysteamine and cystamine against Mycobacterium abscessus. In human macrophages (differentiated THP-1 cells), these drugs restricted M. abscessus growth similar to that achieved by amikacin. Here, we use the human ex vivo granuloma-like structures (GLS) model of infection with the M. abscessus rough (MAB-R) and smooth (MAB-S) variants to study the activity of new therapies against M. abscessus. We demonstrate that cysteamine and cystamine show a decrease in the number of total GLSs per well in the MAB-S and MAB-R infected human peripheral blood mononuclear cells (PBMCs). Furthermore, combined administration of cysteamine or cystamine with amikacin resulted in enhanced activity against the two M. abscessus morpho variants compared to treatment with amikacin only. Treatment with cysteamine and cystamine was more effective in reducing GLS size and bacterial load during MAB-S infection compared with MAB-R infection. Moreover, treatment with these two drugs drastically quenched the exuberant proinflammatory response triggered by the MAB-R variant. These findings showing the activity of cysteamine and cystamine against the R and S M. abscessus morphotypes support the use of these drugs as novel host-directed therapies against M. abscessus infections.

Non-tuberculous mycobacteria in Australians with cystic fibrosis: A national survey

Introduction/Aim: We are seeing the rapid emergence of a significant new threat to CF survival;chronic nontuberculous mycobacterial (NTM) infection. This study aims to understand the aetiology and epidemiology of NTM in Australians with CF. Methods: Nationally, nine adult and nine paediatric CF services prospectively collected respiratory samples from people with CF (pwCF) for acid fast bacilli (AFB) culture at regular clinic appointments (Baseline, 6 months, 1 year, then annual to 4 years);associated clinical data, geographic and social data was also collected. Sites commenced recruitment between December 2016 and August 2018. Retrospective clinical and culture data were also collected to offset the shift to a telehealth model of care during the global coronavirus pandemic. Results: 15.1% of 1322 study participants cultured NTM (NTM+) from at least one AFB culture during the study, 5.1% of study participants were M. abscessus (MABS) positive. Adolescents and young adults (11-25 years) had the highest rates of NTM infection (19%, p = 0.0004). MABS was more commonly isolated in participants <25 years (6.7%) compared to participants 25 years and older (2.5%, p < 0.001). Of NTM+ study participants, 49% were incident cases. The species of NTM recovered from participants varied depending on the Australian state of residence, with South Australia, Western Australia and Tasmania having greater diversity of isolated species. Conclusion: In Australia, during this sampling period pwCF <25 years of age were more likely to be infected with MABS than older pwCF. We hypothesize that this may be due to increasing attempts at eradication of Pa in early life and/or increased exposure from environmental sources at a vulnerable age.

MmpL3 Inhibition: A New Approach to Treat Nontuberculous Mycobacterial Infections.

Outside of Mycobacterium tuberculosis and Mycobacterium leprae, nontuberculous mycobacteria (NTM) are environmental mycobacteria (>190 species) and are classified as slow- or rapid-growing mycobacteria. Infections caused by NTM show an increased incidence in immunocompromised patients and patients with underlying structural lung disease. The true global prevalence of NTM infections remains unknown because many countries do not require mandatory reporting of the infection. This is coupled with a challenging diagnosis and identification of the species. Current therapies for treatment of NTM infections require multidrug regimens for a minimum of 18 months and are associated with serious adverse reactions, infection relapse, and high reinfection rates, necessitating discovery of novel antimycobacterial agents. Robust drug discovery processes have discovered inhibitors targeting mycobacterial membrane protein large 3 (MmpL3), a protein responsible for translocating mycolic acids from the inner membrane to periplasm in the biosynthesis of the mycobacterial cell membrane. This review focuses on promising new chemical scaffolds that inhibit MmpL3 function and represent interesting and promising putative drug candidates for the treatment of NTM infections. Additionally, agents (FS-1, SMARt-420, C10) that promote reversion of drug resistance are also reviewed.