Molecular characterisation and potential pathogenicity analysis of Acanthamoeba isolated from recreational lakes in Peninsular Malaysia.

The present study aims to identify the Acanthamoeba genotypes and their pathogenic potential in three recreational lakes in Malaysia. Thirty water samples were collected by purposive sampling between June and July 2022. Physical parameters of water quality were measured in situ while chemical and microbiological analyses were performed in the laboratory. The samples were vacuum filtered through nitrate filter, cultured onto non-nutrient agar and observed microscopically for amoebic growth. DNAs from positive samples were extracted and made to react with polymerase chain reaction using specific primers. Physiological tolerance tests were performed for all Acanthamoeba-positive samples. The presence of Acanthamoeba was found in 26 of 30 water samples by PCR. The highest rate in lake waters contaminated with amoeba was in Biru Lake (100%), followed by Titiwangsa Lake (80%) and Shah Alam Lake (80%). ORP, water temperature, pH and DO were found to be significantly correlated with the presence of Acanthamoeba. The most common genotype was T4. Temperature- and osmo-tolerance tests showed that 8 (30.8%) of the genotypes T4, T9 and T11 were highly pathogenic. The presence of genotype T4 in habitats related to human activities supports the relevance of this amoeba as a potential public health concern.

Occurrence and molecular characterisation of Acanthamoeba isolated from recreational hot springs in Malaysia: evidence of pathogenic potential.

This study aimed to identify the Acanthamoeba genotypes and their pathogenic potential in five recreational hot springs in Peninsular Malaysia. Fifty water samples were collected between April and September 2018. Physical parameters of water quality were measured in situ while chemical and microbiological analyses were performed in the laboratory. All samples were filtered through the nitrocellulose membrane and tested for Acanthamoeba using both cultivation and polymerase chain reaction (PCR) by targeting the 18S ribosomal RNA gene. The pathogenic potential of all positive isolates was identified using thermo- and osmotolerance tests. Thirty-eight (76.0%) samples were positive for Acanthamoeba. Water temperature (P = 0.035), chemical oxygen demand (P = 0.026), sulphate (P = 0.002) and Escherichia coli (P < 0.001) were found to be significantly correlated with the presence of Acanthamoeba. Phylogenetic analysis revealed that 24 samples belonged to genotype T4, nine (T15), two (T3) and one from each genotype T5, T11 and T17. Thermo- and osmotolerance tests showed that 6 (15.79%) of the Acanthamoeba strains were highly pathogenic. The existence of Acanthamoeba in recreational hot springs should be considered as a health threat among the public especially for high-risk people. Periodic surveillance of hot spring waters and posting warning signs by health authorities is recommended to prevent disease related to pathogenic Acanthamoeba.

Trends in Traumatic Brain Injuries During the COVID-19 Pandemic: A Single-Center Review of Patient Charts From Pakistan.

Introduction A traumatic brain injury (TBI) is one of the leading causes of injury-related deaths, making it a public health concern of extreme importance. In a developing country such as Pakistan, TBIs are significantly underreported, with the treatment frequently being delayed and inadequate, especially in rural healthcare setups all across the country. This concern is further magnified by insufficient epidemiological data on TBIs available in Pakistan. The coronavirus disease 2019 (COVID-19) pandemic brought consequential changes to the healthcare system with the priority shifting toward COVID-19 patients, resulting in considerable changes to the workflow and management of TBIs. The primary objective of this study is to offer valuable insights into the epidemiology of TBIs in Pakistan and its relationship with the impact of the COVID-19 pandemic.  Methods A retrospective study was conducted at a tertiary care center in a metropolitan city in Pakistan. Patient charts were reviewed from January to August 2020, and data was extracted including demographics, clinical presentation, management, and outcomes for cases of TBI. Results The total number of patients is 2126, male 78% and female 21.4%. The mean age of the patients was 28.85. The state of admissions at the hospital is at 99.7% for EME admissions and 0.282% for OPD admissions. Participants presented with loss of consciousness (70.7%), nosebleeds, (53.2%), vomiting (69.0%), and seizures (11.5%). The majority (51.1%) were related to road traffic accidents, followed by falls (20.7%), and assaults (4%). While 1202 (58.5%) of these were managed conservatively, others underwent surgical treatment in the form of craniotomy (28.0%), Burr holes (3.20%), and fracture elevation and repair (10.5%). A decrease in the number of reported TBI cases was observed with lockdown implementation in Pakistan. Conclusion The transportation sector in Pakistan was severely affected by the COVID-19 pandemic, leading to a decline in road traffic injuries and TBIs. Stringent mobility constraints and changes in societal and cultural norms have contributed to this reduction.

Can Free Living Acanthamoeba Act as a Trojan Horse for SARS-Cov-2 on Viral Survival and Transmission in the Environment? A Narrative Review.

Acanthamoeba is a free-living amoeba that has been found on surfaces, air, water and various environmental sources around the world. It enters the human body through the respiratory tract via the nose. Of note, amoebae are well known to act as a reservoir for various pathogenic microorganisms including bacteria and viruses such as Adenoviruses and Mimivirus. Given that SARS-CoV-2 of the Coronaviridae family is transmitted through the respiratory tract, and the Trojan horse nature of Acanthamoeba, it has been suggested that amoebae act as a vector in the transmission of SARS-CoV-2. The aim of this study was to provide an opinion of the possibility of the coexistence of Acanthamoeba with SARS-CoV-2.

Gold Nanoparticles Conjugation Enhances Antiacanthamoebic Properties of Nystatin, Fluconazole and Amphotericin B.

Parasitic infections have remained a significant burden on human and animal health. In part, this is due to lack of clinically-approved, novel antimicrobials and a lack of interest by the pharmaceutical industry. An alternative approach is to modify existing clinically-approved drugs for efficient delivery formulations to ensure minimum inhibitory concentration is achieved at the target site. Nanotechnology offers the potential to enhance the therapeutic efficacy of drugs through modification of nanoparticles with ligands. Amphotericin B, nystatin, and fluconazole are clinically available drugs in the treatment of amoebal and fungal infections. These drugs were conjugated with gold nanoparticles. To characterize these gold-conjugated drug, atomic force microscopy, ultraviolet-visible spectrophotometry and Fourier transform infrared spectroscopy were performed. These drugs and their gold nanoconjugates were examined for antimicrobial activity against the protist pathogen, Acanthamoeba castellanii of the T4 genotype. Moreover, host cell cytotoxicity assays were accomplished. Cytotoxicity of these drugs and drug-conjugated gold nanoparticles was also determined by lactate dehydrogenase assay. Gold nanoparticles conjugation resulted in enhanced bioactivity of all three drugs with amphotericin B producing the most significant effects against Acanthamoeba castellanii (p ＜ 0.05). In contrast, bare gold nanoparticles did not exhibit antimicrobial potency. Furthermore, amoebae treated with drugs-conjugated gold nanoparticles showed reduced cytotoxicity against HeLa cells. In this report, we demonstrated the use of nanotechnology to modify existing clinically-approved drugs and enhance their efficacy against pathogenic amoebae. Given the lack of development of novel drugs, this is a viable approach in the treatment of neglected diseases.

Boron Nitride Doped Polyhydroxyalkanoate/Chitosan Nanocomposite for Antibacterial and Biological Applications.

The present research focused on the fabrication of biocompatible polyhydroxyalkanoate, chitosan, and hexagonal boron nitride incorporated (PHA/Ch-hBN) nanocomposites through a simple solvent casting technique. The fabricated nanocomposites were comprehensively characterized by Fourier transform infrared spectroscope (FT-IR), field emission scanning electroscope (FESEM), and elemental mapping and thermogravimetric analysis (TGA). The antibacterial activity of nanocomposites were investigated through time-kill method against multi drug resistant (MDR) microbes such as methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli) K1 strains. In addition, nanocomposites have examined for their host cytotoxicity abilities using a Lactate dehydrogenase (LDH) assay against spontaneously immortalized human keratinocytes (HaCaT) cell lines. The results demonstrated highly significant antibacterial activity against MDR organisms and also significant cell viability as compared to the positive control. The fabricated PHA/Ch-hBN nanocomposite demonstrated effective antimicrobial and biocompatibility properties that would feasibly suit antibacterial and biomedical applications.