Surgical aspects and outcomes after nephrectomy for Wilms tumour in sub-Saharan Africa: A report from Wilms Africa Phase II-CANCaRe Africa.

BACKGROUND: Wilms tumour (WT) is one of the common and curable cancer types targeted by the Global Initiative for Childhood Cancer. Tumour excision is essential for cure. This analysis focuses on surgical outcomes of patients with WT in sub-Saharan Africa. METHODS: We implemented a risk-stratified WT treatment guideline as a multicentre, prospective study across eight hospitals and six countries. Eligibility criteria were age 6 months to 16 years, unilateral WT, surgery performed after preoperative chemotherapy and diagnosed between 1 January 2021 and 31 December 2022. Data collection included a specific surgical case report form (CRF). RESULTS: The study registered 230 patients, among whom 164 (71.3%) had a nephrectomy. Ninety-eight percent of patients had a completed surgical CRF. Out 164 patients, 50 (30.5%) had distant metastases. Median tumour diameter at surgery was 11.0 cm. Lymph node sampling was done in 122 (74.3%) patients, 34 (20.7%) had intraoperative tumour rupture, and for 18 (10.9%), tumour resection involved en bloc resection of another organ. Tumour size at surgery was significantly correlated with tumour rupture (p < .01). With a median follow-up of 17 months (range: 2-33), 23 (14.0%) patients have relapsed. Twenty-two (13.4%) patients abandoned treatment post nephrectomy. Two-year event-free survival was 60.4% ± 4.7% with treatment abandonment as an event. CONCLUSION: Survival post nephrectomy is challenged by treatment abandonment, treatment-related mortality and relapse. Large tumours after preoperative chemotherapy were associated with a higher risk of tumour rupture. Earlier diagnosis and access to radiotherapy are expected to improve survival.

Antioxidant, antibacterial, and molecular docking of methyl ferulate and oleic acid produced by Aspergillus pseudodeflectus AUMC 15761 utilizing wheat bran.

Secondary metabolites (SMs) are the primary source of therapeutics and lead chemicals in medicine. They have been especially important in the creation of effective cures for conditions such as cancer, malaria, bacterial and fungal infections, neurological and cardiovascular problems, and autoimmune illnesses. In the present study, Aspergillus pseudodeflectus AUMC 15761 was demonstrated to use wheat bran in solid state fermentation (SSF) at optimum conditions (pH 7.0 at 30 °C after 10 days of incubation and using sodium nitrate as a nitrogen source) to produce methyl ferulate and oleic acid with significant antioxidant and antibacterial properties. Gas chromatography-mass spectrometry (GC-MS) analysis of the crude methanol extract revealed eleven peaks that indicated the most common chemical components. Purification of methyl ferulate and oleic acid was carried out by column chromatography, and both compounds were identified by in-depth spectroscopic analysis, including 1D and 2D NMR and HR-ESI-MS. DPPH activity increased as the sample concentration increased. IC50 values of both compounds obtained were 73.213 ± 11.20 and 104.178 ± 9.53 µM, respectively. Also, the MIC value for methyl ferulate against Bacillus subtilis and Staphylococcus aureus was 0.31 mg/mL, while the corresponding MIC values for oleic acid were 1.25 mg/mL and 0.62 mg/mL for both bacterial strains, respectively. Molecular modeling calculations were carried out to reveal the binding mode of methyl ferulate and oleic acid within the binding site of the crucial proteins of Staphylococcus aureus. The docking results were found to be well correlated with the experimental data.

A regional virtual case discussion forum in pediatric oncology: Experience of the Pediatric Oncology East and Mediterranean Group.

BACKGROUND: The Pediatric Oncology East and Mediterranean (POEM) group that aims to share expertise among pediatric oncology providers across the Middle East, North Africa, and East Asia region initiated a virtual Case Discussion Forum (CDF) in 2013. METHODS: Meeting records from September 2013 till June 2021 were reviewed. Detailed minutes were available starting August 2016; case data were analyzed including diagnoses, purpose of presentation and recommendations. A 38-item survey assessing perception of benefits, challenges, and opportunities of the forum was distributed to members of the POEM group and results analyzed. RESULTS: A total of 140 cases were presented from 14 countries. After August 2016, 67 cases were presented, and those were analyzed regarding reasons for discussion, barriers, and recommendations. Details are presented in this report, and the most common challenges identified were related to histopathologic/molecular diagnosis (24%), imaging interpretation (18%), resource limitations (12%), and surgical difficulties (9%). A survey was distributed to all POEM members in 28 countries, and 76 responded. The main benefit reported was the provision of recommendations regarding treatment and evaluation, while the main challenges reported were time zone difference and workload. Recognized opportunities included conducting regionally relevant research studies based on clinical problems identified during discussions, and setting guidelines for resource-adapted treatment regimens. CONCLUSIONS: The POEM CDF identified areas for multi-institutional regional studies and led to a twinning project between two centers in the region for improving diagnostic infrastructure. Such forums can identify specific resource limitations in pediatric cancer and direct efforts for targeted capacity building.

Malignant Solid Pseudopapillary Neoplasm of the Pancreas: An Orthogonal Analysis.

BACKGROUND: Pancreatic solid pseudopapillary neoplasms (SPN) are generally indolent; however, some patients present with "malignant" SPN. An orthogonal analysis of multiple datasets was performed to investigate the utility of complete surgical resection (CSR) for malignant SPN. METHODS: A systematic review was performed for cases of malignant SPN, defined as T4, N1, and/or M1. Malignant SPN was analyzed within the National Cancer Database (NCDB) and compared with T1-3N0M0 SPN. Predictors of malignant SPN were assessed, and treatments were analyzed by using survival analysis. RESULTS: The systematic review yielded 164 cases of malignant SPN. Of 31 children, only one died due to malignant SPN. Among adults, CSR was associated with improved disease-specific survival (DSS) (P = 0.0002). Chemotherapy did not improve malignant SPN DSS, whether resected (P = 0.8485) or not (P = 0.2219). Of 692 adults with SPN within the NCDB, 93 (13.4%) had malignant SPN. Pancreatic head location (odds ratio [OR] 2.174; 95% confidence interval [CI] 1.136-4.166; P = 0.0186) and tumor size (OR 1.154; 95% CI 1.079-1.235; P < 0.0001) associated with the malignant phenotype. Malignant SPN predicted decreased overall survival (OS) compared with T1-3N0M0 disease (P < 0.0001). Resected malignant SPN demonstrated improved OS (P < 0.0001), including resected stage IV malignant SPN (P = 0.0003). Chemotherapy did not improve OS for malignant SPN, whether resected (P = 0.8633) or not (P = 0.5734). Within a multivariable model, resection was associated with decreased hazard of death (hazard ratio 0.090; 95% CI 0.030-0.261; P < 0.0001). CONCLUSIONS: Approximately 13% of patients with SPN present with a malignant phenotype. Pediatric cases may be less aggressive. Resection may improve survival for malignant SPN, which does not appear chemosensitive.

Ovarian-sparing surgery for ovarian tumors in children: A systematic review and meta-analysis.

INTRODUCTION: An increased number of children and adolescents with ovarian tumors have been managed with ovarian-sparing surgery in the last few years. However, comprehensive data on fertility outcomes and local relapse are scarce. In this study, we systematically describe the contemporary outcomes of ovarian-sparing surgery, as reported in the literature. MATERIALS AND METHODS: Using PRISMA guidelines, we analyzed studies reporting ovarian-sparing techniques for ovarian tumors in children and adolescents. from 1980 to 2022. Reports with fewer than three patients, narrative reviews, and opinion articles were excluded. Statistical analysis was performed for dichotomous and continuous variables. RESULTS: Of 283 articles screened, 16 papers (3057 patients) met inclusion criteria (15 retrospective/1 prospective) and were analyzed. The vast majority of studies had no long-term fertility follow-up data and direct comparison between ovarian-sparing surgery vs oophorectomy was reported in only a few studies. Ovarian sparing surgery was not associated with worse oncologic outcomes in terms of (i) tumour spillage or (ii) recurrence rates, and of key importance allowed a higher ovarian reserve at long term follow-up. CONCLUSIONS: Ovarian-sparing surgery is a safe and feasible technique for benign tumors. Long-term outcome studies are needed to show efficacy and fertility preservation.

Aggressive Pursuit of No Evidence of Disease Status in Hepatoblastoma Improves Survival: An Observational Study.

BACKGROUND: The utility of repeated surgical interventions in hepatoblastoma to achieve no evidence of disease (NED) is not well-defined. We examined the effect of aggressive pursuit of NED status on event-free (EFS) and overall survival (OS) in hepatoblastoma with subgroup analysis of high-risk patients. METHODS: Hospital records were queried for patients with hepatoblastoma from 2005 to 2021. Primary outcomes were OS and EFS stratified by risk and NED status. Group comparisons were performed using univariate analysis and simple logistic regression. Survival differences were compared with log-rank tests. RESULTS: Fifty consecutive patients with hepatoblastoma were treated. Forty-one (82%) were rendered NED. NED was inversely correlated with 5-year mortality (OR 0.006; CI 0.001-0.056; P < .01). Ten-year OS (P < .01) and EFS (P < .01) were improved by achieving NED. Ten-year OS was similar between 24 high-risk and 26 not high-risk patients when NED was attained (P = .83). Fourteen high-risk patients underwent a median of 2.5 pulmonary metastasectomies, 7 for unilateral disease, and 7 for bilateral, with a median of 4.5 nodules resected. Five high-risk patients relapsed, and three were salvaged. CONCLUSIONS: NED status is necessary for survival in hepatoblastoma. Repeated pulmonary metastasectomy and/or complex local control strategies to obtain NED can achieve long-term survival in high-risk patients. LEVEL OF EVIDENCE: Level III - Treatment Study - Retrospective Comparative Study.

Indocyanine green near infrared-guided surgery in children, adolescents, and young adults with otolaryngologic malignancies.

OBJECTIVE: Head and neck cancers represent critical challenges due to the restricted anatomical space in children and the proximity of critical neurovascular structures which can compromise complete tumor resection. Applications of Indocyanine green (ICG) near infrared (NIR) fluorescent image-guided surgery (FGS) have recently expanded into the pediatric population, emphasizing its relevance for tumor delineation and evaluation of tissue perfusion. The objectives of the present study are twofold. First, we aim to assess the role of ICG NIR imagery in identifying neoplastic disease and second, to evaluate its role as an adjunct to identify metastatic deposits in cervical lymph node in children, adolescents, and young adults with head and neck cancers. METHODS: Eight patients with head and neck malignancies underwent ICG NIR FGS, between January 2019 and November 2021. ICG NIR findings were compared with preoperative cross-sectional imaging and results of operative tissue pathology analyses. RESULTS: All primary tumors were identified on preoperative imaging and intraoperatively with ICG NIR; however, for one case, extension of tumor was revealed with ICG NIR and confirmed by histopathological examination but was not otherwise visible on preoperative imaging or with naked eye visual and tactile assessment. ICG NIR assisted the decision process in a difficult case for which curative resection, without significant functional morbidity and potential mortality, was unrealistic. Although ICG NIR evaluation of the surgical bed did not display residual tumor, margins were found positive in two cases. ICG NIR evaluation for local metastases changed the surgical strategy in one patient by prompting conversion to bilateral neck dissections. The sensitivity of preoperative multimodality imaging to identify cervical levels of invasion was 75% with a specificity of 70%, a PPV of 33%, a NPV of 78% and an accuracy of 72%. The ICG NIR sensitivity was 83%, its specificity was 88% with a PPV of 91%, a NPV of 80% and an accuracy of 86%. The combination of preoperative multimodality imaging with ICG NIR findings led to a sensitivity of 83%, specificity of 88% and accuracy of 86%. CONCLUSION: This case series provides a proof of concept of the feasibility of ICG NIR, as an adjunct in tumor and local metastases identification in young patients with head and neck tumors. It revealed to be feasible and safe for intra-operative tumor identification, thus guiding and facilitating resection. However, it showed some limitations in precise tumor margin assessment. The combination of preoperative multimodality imaging with ICG NIR findings improved local metastases localization.

Current status of African pediatric oncology education efforts aligned with the Global Initiative for Childhood Cancer.

Education of the pediatric oncology workforce is an important pillar of the World Health Organization CureAll technical package. This is not only limited to healthcare workers, but all stakeholders in the childhood cancer management process. It includes governmental structures, academic institutions, parents and communities. This review evaluated the current educational and advocacy training resources available to the childhood cancer community, the contribution of SIOP Africa in the continental educational needs and evaluated future needs to improve the management of pediatric malignancies in reaching the Global Initiative for Childhood Cancer goals. Childhood cancer, unlike adult cancers, has not been prioritized in African cancer control plans nor the teaching and advocacy surrounding pediatric oncology. The availability of formal training programs for pediatric oncologists, pediatric surgeons and radiotherapy specialists are limited to particular countries. In pharmacy and nutritional services, the exposure to pediatric oncology is limited while training in advocacy doesn't exist. Many nonacademic stakeholders are creating the opportunities in Africa to gain experience and train in these various fields, but formal training programs should still be advocated for. LEARNING POINTSThe African continent has various resources to increase the capacity of childhood cancer care stakeholders to increase their knowledge.African pediatric oncology teams rely on a multitude of international sources for training while developing their own.There is a greater need for formal, standardized cancer training especially for pediatric surgeons, radio-oncologists and nurses.Greater inclusion of pathologists, pediatric oncology pharmacists and dieticians into multidisciplinary care and childhood cancer training should be facilitated and resourced.Successful advocacy programs and tool kits exist in parts of Africa, but the training in advocacy is still underdeveloped.

Minimally invasive approach of paediatric neuroblastoma with thoracic vascular encasement.

ABSTRACT: Neuroblastoma (NB) is the most frequent paediatric extracranial solid tumour. The surgical management of these tumours in newborns changed recently, performing resections in cases with tumour size increase after birth. Minimally invasive procedures were mostly reported in cases without pre-operative image-defined risk factors (IDRFs), defined by vascular and organ involvement. Thoracoscopic resection represents a minority of the overall surgical procedures for neuroblastic tumour management, as the posterior mediastinum is one of the least frequent locations of NB. A thoracoscopic resection was performed on a 22-month-old child with a NB encasing the aorta and a 6-month-old child with the encasement of the left subclavian and vertebral artery. A step-by-step minimally invasive procedure was described, highlighting anatomical landmarks and dissection techniques. The described technique was performed in 130 min. Thoracoscopic resection provided a macroscopic resection without surgical complications and patient was discharged on the 3rd post-operative day. The study shows a feasible and safe thoracoscopic approach for paediatric thoracic NB with IDRFs.

Production of cold-active pectinases by three novel Cladosporium species isolated from Egypt and application of the most active enzyme.

Cladosporium parasphaerospermum, Cladosporium chlamydosporigenum, and Cladosporium compactisporum have all been discovered and characterized as new Cladosporium species. The three new species seemed to generate cold-active pectinases with high activity at pH 6.0 and 10 °C, pH 6.0 and 15 °C, and pH 5.0 and 15 °C, respectively, with the most active being C. parasphaerospermum pectinase. In submerged fermentation (SmF), C. parasphaerospermum produced the most cold-active pectinase with the highest activity and specific activity (28.84 U/mL and 3797 U/mg) after 8 days. C. parasphaerospermum cold-active pectinase was isolated using DEAE-Cellulose anion exchange resin and a Sephadex G 100 gel filtration column. The enzyme was purified 214.4-fold and 406.4-fold greater than the fermentation medium using DEAE-cellulose and Sephadex G 100, respectively. At pH 7.0 and 10 °C, pure pectinase had the highest activity (6684 U/mg), with Km and Vmax determined to be 26.625 mg/mL and 312.5 U/min, respectively. At 5 mM/mL, EDTA, MgCl2, and SDS inhibited the activity of pure pectinase by 99.21, 96.03, and 94.45%, respectively. The addition of 10 U/mL pure pectinase enhanced the yield of apple, orange, apricot, and peach juice by 17, 20, 13, and 24%, respectively, and improved the clarity and colour of orange juice by 194 and 339%, respectively. We can now add cold-active pectinase production to the long list of Cladosporium species that have been identified. We also report three new species that can be used in biotechnological solutions as active microbial pectinase producers. Although further research is needed, these distinct species might be used to decompose difficult and resistant pertinacious wastes as well as clear fruit juices.

Conference report on the 14th International Society of Paediatric Oncology African Continental Meeting, 16-18 March 2022, Kampala, Uganda.

Together with the Africa Continental Branch of the International Society of Paediatric Oncology (SIOP Africa), the Uganda Cancer Institute, a tertiary governmental institution for specialised cancer care services, research and training, hosted the 14th continental meeting of SIOP Africa from the 16-18 March 2022. Under the conference theme, 'Innovate for Africa', the hybrid conference brought together close to 400 international delegates to discuss innovations and experiences, as well as share the latest research in the field of paediatric oncology. The World Health Organisation 2030 Global Initiative for Childhood Cancer provided the main starting point for the conference with a comprehensive pre-conference workshop programme, from multiple stakeholders and organisations and the themes for the plenaries towards improving survival to the main breakout sessions. Delegates discussed various ways of improving outcomes in Africa, despite the challenges faced individually and collectively ranging from education, management systems and treatment guidelines to future governmental and NGO involvement in African cancer care. The main achievements of the conference were various commitments for collaboration, investing in junior investigators, development of registries and systems for improved childhood care on the African continent, while working towards greater access to advanced management options such as targeted therapies and bone marrow transplant services.

Lactoferrin improves the immune response and resistance of silver carp, a hematological, light (histochemical and immunohistochemical), fluorescent, and scanning electron microscopic study.

Lactoferrin is a multifunctional protein that has roles in iron metabolism, cell generation and differentiation, and antibacterial, antiviral, and antiparasitic activity. The study aim was to evaluate the effect of dietary lactoferrin powder on the innate immune response and disease resistance of silver carp (Hypophthalmichthys molitrix) infected with Vibrio vulnificus. The study also investigates immune cells in different organs including gills, intestine, spleen, liver, and pancreas using light, scan electron microcopy. Two diet regimes, a basic diet and a 600-mg/kg bovine lactoferrin-supplemented diet were used. The fish were fed for 30 successive days. We included 270 apparently healthy silver carp (H. Molitrix) with an average body weight of 10 ± 2 g/fish. Addition of lactoferrin to the diet led to an increase in the activity of non-specific immune parameters; lymphocytes, and in the monocytes percentage, and in total protein, serum globulin, and albumin, with a corresponding increase in phagocytic activities and indices. The histological analysis revealed increase immune cells such as lymphocytes in intestine, rodlet cells in liver, gills, and pancreas, and the macrophages in liver, pancreas as well as spleen. The lactoferrin-supplemented diet significantly increased survival and disease resistance following V. vulnificus challenge, which seemed to correspond to an enhancement of non-specific immune functions in H. molitrix. RESEARCH HIGHLIGHTS: The study evaluates the effect of dietary lactoferrin powder on the innate immune response and disease resistance of silver carp (Hypophthalmichthys molitrix) infected with Vibrio vulnificus. The study also investigates immune cells in different organs including gills, intestine, spleen, liver, and pancreas using light, scan electron microcopy. Lactoferrin increases the activity of nonspecific immune parameters; lymphocytes, and in the monocytes percentage, and in total protein, serum globulin, and albumin, with a corresponding increase in phagocytic activities and indices. The histological analysis revealed increase immune cells such as lymphocytes in intestine, rodlet cells in liver, gills, and pancreas, and the macrophages in liver, pancreas as well as spleen.

Estimates of Treatable Deaths Within the First 20 Years of Life from Scaling Up Surgical Care at First-Level Hospitals in Low- and Middle-Income Countries.

BACKGROUND: Surgical care is an important, yet often neglected component of child health in low- and middle-income countries (LMICs). This study examines the potential impact of scaling up surgical care at first-level hospitals in LMICs within the first 20 years of life. METHODS: Epidemiological data from the global burden of disease 2019 Study and a counterfactual method developed for the disease control priorities; 3rd Edition were used to estimate the number of treatable deaths in the under 20 year age group if surgical care could be scaled up at first-level hospitals. Our model included three digestive diseases, four maternal and neonatal conditions, and seven common traumatic injuries. RESULTS: An estimated 314,609 (95% UI, 239,619-402,005) deaths per year in the under 20 year age group could be averted if surgical care were scaled up at first-level hospitals in LMICs. Most of the treatable deaths are in the under-5 year age group (80.9%) and relates to improved obstetrical care and its effect on reducing neonatal encephalopathy due to birth asphyxia and trauma. Injuries are the leading cause of treatable deaths after age 5 years. Sixty-one percent of the treatable deaths occur in lower middle-income countries. Overall, scaling up surgical care at first-level hospitals could avert 5·1% of the total deaths in children and adolescents under 20 years of age in LMICs per year. CONCLUSIONS: Improving the capacity of surgical services at first-level hospitals in LMICs has the potential to avert many deaths within the first 20 years of life.

Colonic mucosal eosinophilia and immunohistochemical expression of COX-2 and NF-kB in patients with irritable bowel syndrome.

BACKGROUND: There is growing evidence that eosinophilic infiltration can release mediators which are harmful to the intestinal epithelium in patients with irritable bowel syndrome (IBS). Although cyclooxygenase 2 (COX-2) and nuclear factor-kappa beta (NF-kB) expression had been previously reported to increase in many inflammatory conditions, there is a paucity in data investigating their expressions in IBS. Our aim was to evaluate colonic mucosal eosinophilia and immunohistochemical expression of COX-2 and NF-kB in patients with irritable bowel syndrome. METHODS: A total of 80 patients who met the inclusion criteria of IBS based on Rome IV symptoms questionnaire were subjected to abdominal ultrasound, laboratory investigations, serum immunoglobulin E (IgE) level assessment and colonoscopic examination. Immunohistochemistry was performed to detect COX-2 and NF-kB expression in colonic biopsies obtained from IBS patients. RESULTS: Histopathological examination showed that 60 colonic biopsy specimens (75%) showed few mixed inflammatory cells ≤3 cells/ HPF, 12 biopsy specimens (15%) showed eosinophilic infiltration ≥25 eosinophils/HPF and 8 biopsy specimens (10%) showed severe lymphocytic infiltration and aggregation. Colonic eosinophilic infiltrate was significantly higher among patients presented with IBS-D subtype. Serum IgE was significantly higher among patients with colonic eosinophilic infiltrate than the others. In IBS-D patients, colonic mucosa showed positive expression of COX-2 and NF-kB in 52.1% and 81.25% of cases, respectively. CONCLUSION: Patients with IBS -particularly IBS-D subtype- should undergo colonoscopy and biopsy to exclude underlying inflammatory pathology. Moreover, patients with positive COX-2 and NF-kB need further evaluation and follow-up.

Diagnosis Disclosure Preferences of Cancer Patients in Egypt: A Multi-Institutional Cross-Sectional Study.

BACKGROUND: Although diagnosis disclosure to cancer patients has important roles in cancer care, it is not a routine practice in countries like Egypt. Respecting patients' autonomy and responding to their preferences are among the factors that should guide the practice of cancer diagnosis disclosure. OBJECTIVES: To assess the preferences of Egyptian cancer patients regarding the disclosure of cancer diagnosis and to determine factors that may affect their preferences. METHODS: The study included 295 patients aware of their cancer diagnosis from 3 cancer care facilities in Egypt. Patients were asked if they would have preferred to be informed of the diagnosis or not, whom they would have preferred to receive the diagnosis information from, and if they would have preferred to tell their families or not. RESULTS: The vast majority (91%) of the included patients preferred to be informed about their diagnosis, 59% preferred to disclose the diagnosis to their families and 66% preferred to receive the diagnosis information from a physician. In univariate analysis, male gender, higher education level and employment were significantly associated with the preference for disclosure. None of the studied variables associated significantly with the preferences in multivariate analysis. CONCLUSION: The majority of Egyptian cancer patients in our study preferred to be informed about their diagnosis, which should be respected. The results may help in changing the diagnosis disclosure practice of health care professionals and refuting the misconception of family caregivers about cancer diagnosis disclosure in Egypt and countries with similar culture.

Pulmonary Complications in Children Following Hematopoietic Cell Transplantation: A Case Report and Review of the Diagnostic Approach.

Pulmonary complications are common in children following hematopoietic cell transplantation (HCT) and contribute to their morbidity and mortality. Early diagnosis is essential for management and prevention of progression of lung injury and damage. In many cases, diagnosis can be challenging and may require diagnostic imaging and more invasive testing such as bronchoscopy and lung biopsy. We report the case of a 12-year-old girl who developed recurrent episodes of acute respiratory failure requiring intensive care unit admission in the post-HCT phase and describe the diagnostic and multidisciplinary approach for her management. In addition, we review the diagnostic approach of pulmonary complications post-HCT and highlight the utility and risks of bronchoscopy and lung biopsy in these children.

Isolation and Identification of Pathogenic Acanthamoeba Species from Air Conditioning Systems, Egypt.

Acanthamoeba are free-living amoebae that cause granulomatous amoebic encephalitis and keratitis. In this study, we aimed to isolate and identify Acanthamoeba from air conditioning systems using in vitro cell culture and polymerase chain reaction assays. We also estimated the pathogenicity of the isolates by measuring their thermotolerance and studying mice models inoculated with these isolates. Of the 80 dust samples acquired, 41 (51.25%) were found to be positive for Acanthamoeba spp. using in vitro cell culture and the results were validated using PCR. Out of these 41 samples, 27 (65.9%) were thermotolerant and 16 (39%) samples could infect mice and cause histopathological effects. Highly pathogenic Acanthamoeba isolates were characterized by their thermotolerance and the ability to disseminate in all organs after infection, causing early death of infected animals. Our study thus validated the presence of pathogenic isolates of Acanthamoeba in air conditioners that may be potentially infectious to humans.