Postharvest decay of vegetables and fruits presents a significant threat confronting sustainable food production worldwide, and in the recent times, applying synthetic fungicides has become the most popular technique of managing postharvest losses. However, there are concerns and reported proofs of hazardous impacts on consumers’ health and the environment, traceable to the application of chemical treatments as preservatives on fresh produce. Physical methods, on the other hand, cause damage to fresh produce, exposing it to even more infections. Therefore, healthier and more environmentally friendly alternatives to existing methods for managing postharvest decays of fresh produce should be advocated. There is increasing consensus that utilization of biological control agents (BCAs), mainly fungi, represents a more sustainable and effective strategy for controlling postharvest losses compared to physical and chemical treatments. Secretion of antifungal compounds, parasitism, as well as competition for nutrients and space are the most common antagonistic mechanisms employed by these BCAs. This article provides an overview of (i) the methods currently used for management of postharvest diseases of fresh produce, highlighting their limitations, and (ii) the use of biocontrol agents as an alternative strategy for control of such diseases, with emphasis on fungal antagonists, their mode of action, and, more importantly, their advantages when compared to other methods commonly used. We therefore hypothesize that the use of fungal antagonists for prevention of postharvest loss of fresh produce is more effective compared to physical and chemical methods. Finally, particular attention is given to the gaps observed in establishing beneficial microbes as BCAs and factors that hamper their development, particularly in terms of shelf life, efficacy, commercialization, and legislation procedures.

Species belonging to the Mycobacterium kansasii complex (MKC) are frequently isolated from humans and the environment and can cause serious diseases. The most common MKC infections are caused by the species M. kansasii (sensu stricto), leading to tuberculosis-like disease. However, a broad spectrum of virulence, antimicrobial resistance and pathogenicity of these non-tuberculous mycobacteria (NTM) are observed across the MKC. Many genomic aspects of the MKC that relate to these broad phenotypes are not well elucidated. Here, we performed genomic analyses from a collection of 665 MKC strains, isolated from environmental, animal and human sources. We inferred the MKC pangenome, mobilome, resistome, virulome and defence systems and show that the MKC species harbours unique and shared genomic signatures. High frequency of presence of prophages and different types of defence systems were observed. We found that the M. kansasii species splits into four lineages, of which three are lowly represented and mainly in Brazil, while one lineage is dominant and globally spread. Moreover, we show that four sub-lineages of this most distributed M. kansasii lineage emerged during the twentieth century. Further analysis of the M. kansasii genomes revealed almost 300 regions of difference contributing to genomic diversity, as well as fixed mutations that may explain the M. kansasii’s increased virulence and drug resistance.

Mucormycosis, an opportunistic fungal infection, is on the increase. Individuals at risk are those with diabetes mellitus, haematological malignancy, etc. Infections are uncommon in human immunodeficiency virus (HIV). Clinical presentations include rhinocerebral, pulmonary or disseminated forms. Risk factors should alert clinicians to a high index of suspicion. Prompt diagnosis, facilitated by radiological imaging and tissue sampling, with appropriate medical and surgical intervention can potentially improve patient outcomes. Here we describe a rare case of renal mass in a patient living with HIV presenting to casualty department with abdominal pain and fever. Radiological imaging showed a renal mass whilst histopathological findings were suggestive of mucormycosis. Management included antifungal therapy and subsequent nephrectomy. The patient improved significantly and was discharged home.

Introduction: South Africa has one of the top ten tuberculosis burdens in the world, only lagging behind countries with significantly larger populations. Increased awareness of extrapulmonary tuberculosis, specifically spinal tuberculosis, is necessary, because of the HIV epidemic.Case presentation: This report describes the case of a 9-year-old male patient who was suspected of having multidrug-resistant (MDR) tuberculosis, based on failure to recover clinically and radiologically after 6 months on first-line anti-tuberculosis treatment. Pus samples were sent to an accredited academic laboratory for histopathology, microscopy, culture, line-probe assay (MTBDRplus assay) and phenotypic MGIT 960 drug susceptibility tests. Second-line MDR tuberculosis treatment was introduced. Clinical, radiological, physical processes and more laboratory tests were conducted to document whether or not there was improvement in the patient.Management and outcome: After laboratory diagnosis of MDR tuberculosis, the patient was started on MDR tuberculosis treatment. The patient started improving remarkably after the introduction of anti-tuberculosis treatment and rehabilitation, although he also required surgery to stabilise the spine. Neurological improvement was observed in the patient and he fully recovered.Discussion: Although the diagnosis of spinal MDR tuberculosis may not be achieved easily by culture, the well-known gold standard method of tuberculosis diagnosis, it is of great importance to rapidly initiate an effective anti-tuberculosis treatment of drug-resistant strains to reduce the deformity of the spine.

Invasive infections caused by yeasts are associated with high mortality and morbidity, and resistance to antifungal agents is increasing. Candida spp. has emerged as the leading cause of systemic nosocomial fungal infections. The aim of this study was to identify yeast isolates from sterile site specimens to species level, and to determine their susceptibility to fuconazole and voriconazole, at the National Health Laboratory, Service Dr George Mukhari Tertiary Laboratory from March to August 2007. Candida isolates were identifed to species level using a germ tube test and/or Api® ID 32C kits. Antifungal susceptibility testing to fuconazole and voriconazole was performed using the disc diffusion method in accordance with the Clinical and Laboratory Standards Institute guidelines. All of the Candida isolates were from the neonatal intensive care unit (NICU), with the exception of two. The distribution of yeast isolates was as follows: C. krusei (41.9%), C. albicans (32.3%), C. inconspicua (5.5%), C. parapsilosis (2%), C. tropicalis (1.5%), C. sake (1.5%), C. lambica (1.5%), and C. valida (0.5%). Cryptococcus neoformans (11%), C. albidus (0.5%), Rhodotorula glutinis (1%), and C. humicola (0.5%) were also isolated. Of the isolated C. albicans, 61% were susceptible to fluconazole. A possible C. krusei outbreak could have occurred in the NICU during the study period. Voriconazole was the most susceptible antifungal agent to various yeast pathogens. The results of this study on azoles susceptibility testing of yeasts show that voriconazole may prove to be a valuable alternative antifungal agent in this tertiary hospital for the treatment of infections caused by yeasts, including Candida spp.

Background: Infectious diseases remain a leading cause of mortality in South Africa, compounded by a high HIV prevalence. This study aimed to delineate the spectrum and clinicopathological characteristics of fatal infectious diseases through a postmortem audit to inform clinical practice and public health strategy. Methods: A retrospective, cross-sectional descriptive study was conducted on all autopsies with a final cause of death attributed to infectious disease at a National Health Laboratory Service, in Northern Pretoria, Gauteng, South Africa, from 2012 to 2021. Using the Systematised Nomenclature of Medicine Clinical Terms (SNOMED) code and word search engines codes, 55 cases were identified. Data on demographics, clinical presentation, HIV status, antiretroviral therapy (ART), comorbidities, and final autopsy diagnosis were extracted from the laboratory information system. Histological confirmation was performed using standard stains. Descriptive statistical analysis was conducted using STATA-18. Results: The cohort (n = 55) had a median age of 31 years (IQR 19–45) and was predominantly female (67%). HIV prevalence was 35%, with 68% of those on ART. The leading cause of death was multilobar pneumonia (36%), followed by bronchopneumonia (22%). AIDS-defining illnesses were present in 27% of cases, with disseminated tuberculosis being the most common (46%). Septic shock was identified in 18% of decedents. A significant proportion (60%) of the cohort was HIV-negative. Conclusions: This autopsy series reveals a high burden of fatal community-acquired pneumonias and HIV-associated opportunistic infections, with a notable proportion of deaths occurring in HIV-negative individuals. The findings underscore diagnostic gaps and highlight the critical role of autopsy in accurate mortality surveillance, advocating for enhanced antemortem diagnostic protocols and targeted public health interventions.