Modelling the Potential Risk of Infection Associated with Listeria monocytogenes in Irrigation Water and Agricultural Soil in Two District Municipalities in South Africa

Listeria monocytogenes (L. monocytogenes) is the etiologic agent of listeriosis which significantly affects immunocompromised individuals. The potential risk of infection attributed to L. monocytogenes in irrigation water and agricultural soil, which are key transmission pathways of microbial hazards to the human population, was evaluated using the quantitative microbial risk assessment modelling. A Monte Carlo simulation with 10,000 iterations was used to characterize the risks. High counts of L. monocytogenes in irrigation water (mean: 11.96 × 102 CFU/100 mL; range: 0.00 to 56.67 × 102 CFU/100 mL) and agricultural soil samples (mean: 19.64 × 102 CFU/g; range: 1.33 × 102 to 62.33 × 102 CFU/g) were documented. Consequently, a high annual infection risk of 5.50 × 10−2 (0.00 to 48.30 × 10−2), 54.50 × 10−2 (9.10 × 10−3 to 1.00) and 70.50 × 10−2 (3.60 × 10−2 to 1.00) was observed for adults exposed to contaminated irrigation water, adults exposed to contaminated agricultural soil and children exposed to agricultural soil, respectively. This study, therefore, documents a huge public health threat attributed to the high probability of infection in humans exposed to L. monocytogenes in irrigation water and agricultural soil in Amathole and Chris Hani District Municipalities in the Eastern Cape province of South Africa.

The Enhanced Expression of Cruzipain-Like Molecules in the Phytoflagellate Phytomonas serpens Recovered From the Invertebrate and Plant Hosts

Phytomonas serpens is a protozoan parasite that alternates its life cycle between two hosts: an invertebrate vector and the tomato fruit. This phytoflagellate is able to synthesize proteins displaying similarity to the cysteine peptidase named cruzipain, an important virulence factor from Trypanosoma cruzi, the etiologic agent of Chagas disease. Herein, the growth of P. serpens in complex medium (BHI) supplemented with natural tomato extract (NTE) resulted in the increased expression of cysteine peptidases, as verified by the hydrolysis of the fluorogenic substrate Z-Phe-Arg-AMC and by gelatin-SDS-PAGE. Phytoflagellates showed no changes in morphology, morphometry and viability, but the proliferation was slightly reduced when cultivated in the presence of NTE. The enhanced proteolytic activity was accompanied by a significant increase in the expression of cruzipain-like molecules, as verified by flow cytometry using anti-cruzipain antibodies. In parallel, parasites incubated under chemically defined conditions (PBS supplemented with glucose) and added of different concentration of NTE revealed an augmentation in the production of cruzipain-like molecules in a typically dose-dependent way. Similarly, P. serpens recovered from the infection of mature tomatoes showed an increase in the expression of molecules homologous to cruzipain; however, cells showed a smaller size compared to parasites grown in BHI medium. Furthermore, phytoflagellates incubated with dissected salivary glands from Oncopeltus fasciatus or recovered from the hemolymph of infected insects also showed a strong enhance in the expression of cruzipain-like molecules that is more relevant in the hemolymph. Collectively, our results showed that cysteine peptidases displaying similarities to cruzipain are more expressed during the life cycle of the phytoflagellate P. serpens both in the invertebrate and plant hosts.

New variants of SARS-CoV-2, vaccine immune response and the Brazilian reality

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a highly pathogenic β-coronavirus, is the etiologic agent of coronavirus disease 2019 (COVID-19), which gave rise to a difficult to control pandemic, especially in Brazil. Approximately 4,000 mutations have been identified in SARS-CoV-2, with the majority being redundant without having any biological effect on the virus. The aim of the present study was to objectively understand how new SARS-CoV-2 variants can affect vaccine response, in addition to highlighting the current situation in Brazil in the face of the pandemic and considering epidemiological and immunological aspects of COVID-19. The main protective correlate investigated in most vaccines is the neutralizing antibody titer induced by immunizing agents, observed in the pre-clinical phase in animals, whose action is to block the binding of the spike protein to the angiotensin-converting enzyme 2 (ACE2) receptor, preventing infection. Up to the second half of 2021, the variants that are of greatest concern worldwide and require molecular surveillance are Alpha variant (or B.1.1.7 lineage), Beta (or B.1.351 lineage), Gamma (or P1 lineage) and Delta (or B.1.617.2 lineage). Brazil finds itself in a highly unfavorable scenario, with the circulation of variants of concern, mainly Gamma and Delta, with high fatality rates for COVID-19 and low vaccination rate. Given the still latent situation of the COVID-19 pandemic in Brazil, the lack of global planning for action strategies for non-pharmacological prevention measures, there is an imminent risk of the emergence of new variants due to the finding of susceptible hosts and the high proliferative rate of SARS-CoV-2. It is urgent to increase the genotyping of positive samples isolated from infected individuals, the speed of vaccination of the entire population and the unification of non pharmacological preventive measures throughout the country.

Design of primers in the molecular detection of Feline Panleukopenia Virus

Feline Panleukopenia is a disease characterized by a reduction in the number of circulating leukocytes and enteritis with degeneration of the intestinal villi. The etiologic agent, called Feline Panleukopenia virus (FPV), belongs to the Parvoviridae family, is highly contagious and has high mortality and morbidity. Although vaccination of healthy cats is the most effective way to prevent the disease, once the symptoms appear, the treatment is supportive, presenting high mortality in the first days of the disease. FPV positive cats should be hospitalized and isolated for at least 2 weeks to avoid viral transmission. Early detection is usually done with the enzyme-linked immunoadsorption assay (ELISA) test that detects viral antigens in stool samples. As a complementary diagnostic method, in this work it was proposed to implement the Polymerase Chain Reaction (PCR) aimed at the diagnosis of FPV initially in positive samples from two feline vaccines and one canine vaccine. As an approximation to real samples, the commercial vaccines were mixed with feces and blood from a healthy cat. The results showed that the In Silico design was successful strategy based on the VP2 gene sequences of FPV available in GenBank® in conjunction with the sharp visualization of positive controls of the expected size and without amplification. nonspecific or negative controls. The fragments obtained has a nucleotide identity percentage greater than 97% with respect to the information available in Genbank® and corroborates the detection of a VP2 fragment. Thus, the future option of applying the same protocol in a diagnostic way is opened, using samples obtained from suspected patients who are infected with FPV.

Incautious Use of Antibiotics During Covid-19

The severe acute respiratory syndrome corona virus (SARSCoV-2), the etiologic agent of the most detrimental disease of the century, has tragically influenced the world dynamics. One of the major challenges faced by health sector globally, was to establish a treatment regimen and guidelines to combat this lethal condition

The Effectivity of Parsley (Petroselinum crispum) Extract on The Growth Inhibition of Candida Albicans

Background: Denture stomatitis is a type of Candida-associated infection that mainly affects the palatal mucosa. Candida albicans is one of the normal flora that is considered to be the primary etiologic agent in the pathogenesis of denture stomatitis. Denture decontamination is necessary to prevent denture stomatitis. One method of decontamination is by immersing removable dentures in an antifungal solution. Parsley (Petroselinum crispum) is a medicinal plant showing antifungal activity. Objectives: To determine the effectivity of immersion of acrylic resin Plate in parsley extract on inhibition of growth of Candida albicans. Methods: The effectivity of immersion of heat-cured acrylic resin plates in parsley extract on inhibition of C. albicans growth was tested using an experimental laboratory study with a post-test-only control group design. Thirty samples were divided into 5 groups as 0.01%, 0.02%, and 0.05% parsley ethanol extract, 0.1% sodium hypochlorite, and sterile aquadest. The number of colony forming units per mL was obtained after calculating the colonies on SDA media, allowing the minimum inhibitory concentration (MIC) obtained according to the formula. Results: 0.01% parsley ethanol extract is MIC with a mean of 7.4 CFU / ml, which inhibited the growth of C. albicans by 31.05%. The Kruskal Wallis test (p<0.001) results indicate that there is an effectivity of immersion of acrylic resin plate in parsley extract on inhibition of growth of C. albicans. Conclusions: The immersion of acrylic resin plates in parsley ethanol extract with a concentration of 0.01%, 0.02%, and 0.04% has effectivity on the inhibition of growth of C. albicans.

Evaluation of preventive homeopathic treatment against Colibacillosis in swine production

Escherichia coli is the most important etiologic agent implied in neonatal diarrhea in swine; colibacillosis is the disease with highest impact in production of swine. The demands of consumers for meat without chemical residues and the ban on the use of antibiotics and chemotherapics in production of swine compelled to find alternative therapeutic and preventive treatments. Aims: to assess homeopathic treatment as preventive against colibacillosis in swine. Methods: the study was conducted in a farm in Mato Grosso, Brazil; stools of 4 piglets with diarrhea were collected to establish the presence of E. coli; concomitantly it was performed a clinical exam to identify the symptoms leading to the choice of a homeopathy remedy. Newborn piglets were divided into 4 groups (n= 11 or 12): 1) control, subjected to antibiotic treatment against diarrhea; 2) homeopathic treatment, performed with Phosphorus 30cH according to the symptoms collected; 3) biotherapic treatment, performed with Escherichia coli 30cH prepared from the locally obtained bacteria; 4) homeopathic + biotherapics treatment. Results: all 3 groups treated with homeopathy/isotherapy presented a significant reduction of diarrhea compared to the control group (p=0.02); the group treated with Phosphorus 30cH + Escherichia coli 30cH presented the highest weight gain which was significant by comparison to all other groups (p=0.001). Conclusion: homeopathic and biotherapics treatment were more effective than antibiotics in the control of diarrhea in newborn piglets; combination of homeopathic and isopathic treatment resulted in the highest weight gain. These results suggest that homeopathy and isopathy are effective alternatives for the treatment of diarrhea by E. coli in newborn swine.

The Prevalence, Etiological Agents, Clinical Features, Treatment, and Diagnosis of HIV-Associated Oral Candidiasis in Pediatrics Across the World: A Systematic Review and Meta-Analysis

In HIV-infected pediatrics, oral candidiasis (OC) is a global issue of concern due to its association with dysphagia, malnutrition, and mortality. The present systematic review and meta-analysis are the first to determine the prevalence of OC in HIV-infected pediatrics worldwide. We searched international (PubMed, Web of Science, Scopus, and Embase) databases for studies published between January 2000 to May 2020 reporting the epidemiologic features of OC in HIV-infected pediatrics. Inclusion and exclusion criteria were defined to select eligible studies. Data were extracted and presented according to PRISMA guidelines. The results of the meta-analysis were visualized as a forest plot. Heterogeneity was also analyzed using the I2, and τ2 statistics. The publication bias was evaluated using Egger test. The literature search revealed 1926 studies, of which 34 studies met the eligibility criteria, consisting of 4,474 HIV-infected pediatrics from 12 different countries. The overall prevalence of OC among HIV-infected pediatrics was 23.9% (95% CI 17.3–32.0%), and Candida albicans was the most prevalent etiologic agent. Pseudomembranous candidiasis was the predominant clinical manifestation in HIV-infected pediatrics suffering from OC. Thirty articles involving 4,051 individuals provided data on HIV treatment status. Among the 4,051 individuals, 468 (11.53%) did not receive HIV treatment. The data from 11 articles demonstrated that HIV treatment was significantly associated with a reduction in oral Candida colonization or infection. In contrast, others showed the opposite relationship or did not report any statistical data. A high level of I2 (I2 = 96%, P &lt; 0.01) and τ2 (τ2 = 1.36, P &lt; 0.01) was obtained among studies, which provides evidence of notable heterogeneity between studies. OC is approximately frequent in HIV-positive children. Therefore, efforts should be made to teach dental and non-dental clinicians who care for HIV-infected pediatrics to diagnose and treat this infection.

Biomedical Perspectives of Acute and Chronic Neurological and Neuropsychiatric Sequelae of COVID-19

: The incidence of infections from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiologic agent for coronavirus disease 2019 (COVID-19), has dramatically escalated following the initial outbreak in China in late 2019, resulting in a global pandemic with millions of deaths. Although the majority of infected patients survive, and the rapid advent and deployment of vaccines have afforded increased immunity against SARS-CoV-2, long term sequelae of SARS-CoV-2 infection have become increasingly recognized. These include, but are not limited to, chronic pulmonary disease, cardiovascular disorders, and proinflammatory-associated neurological dysfunction that may lead to psychological and neurocognitive impairment. A major component of cognitive dysfunction is operationally categorized as “brain fog” which comprises difficulty with concentration, forgetfulness, confusion, depression, and fatigue. Multiple parameters associated with long-term neuropsychiatric sequelae of SARS-CoV-2 infection have been detailed in clinical studies. Empirically elucidated mechanisms associated with the neuropsychiatric manifestations of COVID-19 are by nature complex, but broad based working models have focused on mitochondrial dysregulation leading to systemic reductions of metabolic activity and cellular bioenergetics within CNS structures. Multiple factors underlying the expression of brain fog may facilitate future pathogenic insults leading to repetitive cycles of viral and bacterial propagation. Interestingly, diverse neurocognitive sequelae associated with COVID-19 are not dissimilar from those observed in other historical pandemics, thereby providing a broad and integrative perspective on potential common mechanisms of CNS dysfunction subsequent to viral infection. Poor mental health status may be reciprocally linked to compromised immune processes and enhanced susceptibility to infection by diverse pathogens. By extrapolation, we contend that COVID-19 may potentiate the severity of neurological/neurocognitive deficits in patients afflicted by well-studied neurodegenerative disorders such as Alzheimer's disease and Parkinson’s disease. Accordingly, the prevention, diagnosis, and management of sustained neuropsychiatric manifestations of COVID-19 are pivotal health care directives and provide a compelling rationale for careful monitoring of infected patients, as early mitigation efforts may reduce short- and long-term complications.

A journey through the Corynebacterium pseudotuberculosis proteome promotes insights into its functional genome

Background Corynebacterium pseudotuberculosis is a Gram-positive facultative intracellular pathogen and the etiologic agent of illnesses like caseous lymphadenitis in small ruminants, mastitis in dairy cattle, ulcerative lymphangitis in equines, and oedematous skin disease in buffalos. With the growing advance in high-throughput technologies, genomic studies have been carried out to explore the molecular basis of its virulence and pathogenicity. However, data large-scale functional genomics studies are necessary to complement genomics data and better understating the molecular basis of a given organism. Here we summarize, MS-based proteomics techniques and bioinformatics tools incorporated in genomic functional studies of C. pseudotuberculosis to discover the different patterns of protein modulation under distinct environmental conditions, and antigenic and drugs targets. Methodology In this study we performed an extensive search in Web of Science of original and relevant articles related to methods, strategy, technology, approaches, and bioinformatics tools focused on the functional study of the genome of C. pseudotuberculosis at the protein level. Results Here, we highlight the use of proteomics for understating several aspects of the physiology and pathogenesis of C. pseudotuberculosis at the protein level. The implementation and use of protocols, strategies, and proteomics approach to characterize the different subcellular fractions of the proteome of this pathogen. In addition, we have discussed the immunoproteomics, immunoinformatics and genetic tools employed to identify targets for immunoassays, drugs, and vaccines against C. pseudotuberculosis infection. Conclusion In this review, we showed that the combination of proteomics and bioinformatics studies is a suitable strategy to elucidate the functional aspects of the C. pseudotuberculosis genome. Together, all information generated from these proteomics studies allowed expanding our knowledge about factors related to the pathophysiology of this pathogen.