Diseases of Gastropoda

Gastropods (class Gastropoda) form the largest of the classes in the phylum Mollusca and inhabit terrestrial, fresh water and marine environments. A large number of these species are of major conservation importance and are an essential component of ecosystems. Gastropods may be deemed as pests, having a negative impact in horticulture and agriculture, whereas others may be used as a food source for human consumption and therefore are beneficial. Gastropods are susceptible to primary diseases and also act as intermediate hosts for diseases which affect other animals, including humans. The diseases described include two that are notifiable to the World Organisation for Animal Health (OIE): Xenohaliotis californiensis and Abalone viral ganglioneuritis caused by Haliotid herpesvirus-1 (HaHV-1). Research into the diseases of gastropods has often focused on those species that act as intermediate disease hosts, those that are used in research or those cultured for food. In this paper we review the viral, bacterial, fungal, parasitic and miscellaneous conditions that have been reported in gastropods and mention some of the factors that appear to predispose them to disease. The pathogenicity of a number of these conditions has not been fully ascertained and more research is needed into specifying both the etiological agent and significance in some of the diseases reported.

Efficacy of current treatments against hepatitis C virus

It is estimated that currently, in the world, approximately 3% of the population has chronic hepatitis, the hepatitis C virus is the etiological agent most related to the development of this pathology. The diversity of genotypes (7) and quasi-species of HCV, due to its high mutation rate, interferes with an effective humoral immunity. The aim of this work is precisely to evoke those usual drugs used in HCV therapy, as well as cutting-edge drugs. The goal of treatment is the eradication of HCV infection. One strategy offered by the WHO is to eradicate the virus in at-risk populations. Alternatives to the previously used treatment with interferon and ribavirin are shown in this paper; protease inhibitors and other targets have now been developed to make eradication of the virus more effective.

Clinico-Mycological Profile of Dermatophytosis in a Tertiary Care Hospital of Eastern Nepal

Background: Dermatophytes are keratinophilic and keratinolytic fungi which are responsible for dermatophytosis. There are three genera of dermatophytes; Trichophyton, Microsporum and Epidermophyton. As they have affinity to keratin rich tissue, they produce dermal inflammatory response, intense itching and cosmetically poor appearance. The varied clinical presentation of tinea results in delay in diagnosis, poor compliance in follow up of cases, and consequently spread of infection in the community has rekindled interest in rapid identification of species. Materials and Methods: A hospital based cross sectional study was carried out in the department of Microbiology, Nobel medical college from January 2019 to December 2019. Clinically suspected 200 cases of dermatophytosis attending Out Patient Department were studied. Isolation and identification was done by various tests like macroscopic, microscopic and biochemical tests. Results: Out of 200 specimens, 138 (69%) were skin scraping, 42 (21%) were nail clipping and 20 (10%) were hair stubs. Highest incidence was seen in the age group 21-40 years with 115 (57.5%) cases followed by 41-60 years 46 (23%) cases. In our study male preponderance of 158 (79%) and female of 42 (21%) were seen. Tinea corporis was found to be the commonest clinical type with 96 (48%) cases followed by tinea unguinum, 42 (21%), Tinea cruris 10 (11.36%), Tinea capitis 5 (5.68%), Tinea faciei 4 (4.54%), Tinea pedis 2 (2.27%). Among the fungal isolates Trichophyton rubrum (67.04%) was the most common etiological agent followed by Trichophyton mentagrophytes (13.63%), Epidermophyton 10 (11.36%), Trichophyton violaceum 4 (4.54%) and Epidermophyton floccosum 3 (3.4%). Conclusion: The most common clinical presentation was tinea corporis followed by tinea unguinum. T. rubrum was the most common etiological agent of dermatophytosis

The rise and fall of SARS-CoV-2 variants and the mutational profile of Omicron

In late December of 2019, high throughput sequencing technologies enabled rapid identification of SARS-CoV-2 as the etiological agent of COVID-19, and global sequencing efforts are now a critical tool for monitoring the ongoing spread and evolution of this virus. Here, we analyze a subset (n=87,032) of all publicly available SARS-CoV-2 genomes (n=~5.6 million) that were randomly selected, but equally distributed over the course of the pandemic. We plot the appearance of new variants of concern (VOCs) over time and show that the mutation rates in Omicron viruses are significantly greater than those in previously identified SARS-CoV-2 variants. Mutations in Omicron are primarily restricted to the spike protein, while 25 other viral proteins—including those involved in SARS-CoV-2 replication—are highly conserved. Collectively, this suggests that the genetic distinction of Omicron primarily arose from selective pressures on the spike, and that the fidelity of replication of this variant has not been altered.

Antiviral Effect of Cerium Dioxide Nanoparticles on the Model of the Causative Agent of Bovine Viral Diarrhea

Cerium dioxide nanoparticles (CeO2) have a wide range of biological properties, including antiviral activity. Preparations based on cerium oxide nanoparticles can be effective against animal RNA viruses, which have the greatest epizootic significance for Ukraine and potentially against human viruses, including SARS-CoV-2. In our studies, we determined the effect of cerium dioxide nanoparticles on bovine viral diarrhea virus (BVDV), a pestivirus that is the etiological agent of bovine viral diarrhea. To determine the antiviral efficacy of CeO2, a cytopathogenic strain of BVDV “BK-1” was used as an etiological agent of bovine viral diarrhea, which induces a cytopathic effect on cow embryo lungs (CEL) cell culture. When evaluating the antiviral efficacy of CeO2, it was determined that the MPC for CEL cell culture is 0.057 μg/cm3, and the CC50 is 0.077 μg/cm3. The antiviral activity of CeO2 was evaluated by the IC50 index, which was 0.036 μg/cm3 and the selectivity index, which after co-administration of CeO2 with BVDV was 2.14. There was a decrease in the titer of infectious activity of the virus during treatment with CeO2 by 2.09 lg TCD50/cm3.

Cocleo-labirintopatie nel bambino

Cochleo-labyrinthopathy (CL) is an affection that in-volves cochlea and vestibular system. It occurs with the association of auditory symptoms (sensorineural hearing loss and tinnitus), vestibular symptoms (objective vertigo, unidirectional horizontal-rotary nystagmus and static or dynamic balance disorders) and neurovegetative signs (nausea, vomiting, pallor, sweating). The diagnosis may be difficult in paediatric age since the child is unable to clearly express their discomfort and symptoms. Multiple causes have been recognized but, in acute cases, infection is the most frequent etiological agent. The paper de-scribes a case of CL due to Herpes Virus 1-2 infection responsive to acyclovir and reports a flow-chart for the diagnostic approach to the vertiginous syndromes in children.

First study of Brucella ovis antibodies in purebred sheep flocks in the State of Parana, Brazil

ABSTRACT Brucella ovis, a non-zoonotic species, is the etiological agent of ovine brucellosis, an infectious disease of clinical or subclinical occurrence in sheep flocks. Until then, there is no serological study of anti-Brucella ovis antibodies in purebred sheep herds. This study aimed to determine the presence of anti-Brucella ovis antibodies in purebred sheep flocks with breeding purposes from Parana State. Blood samples from 728 animals, of which 563 were females and 165 males, between 8 and 56 months of age from the six major sheep producing mesoregions of Parana, were submitted to detection of anti-Brucella ovis antibodies by the Agar Gel Immunodiffusion technique using an antigen from the bacteria Brucella ovis (Reo 198). The results indicate the presence of this disease in purebred sheep from Parana State in a low occurrence of 0.27% (2/728). The only two positive animals were rams, Santa Inês breed, from the same flock in the East Center region of Parana, without clinical disease. In conclusion, Brucella ovis is present in purebred sheep in Parana State, Brazil, and this low occurrence may have occurred due to rigorous breeding systems that may contribute to reduce the transmission of this disease.

Was Chagas disease responsible for Darwin’s illness? The overlooked eco-epidemiological context in Chile

The source of Darwin’s illness has been a contentious issue in the literature for almost 70 years. Different causal factors have been invoked to account for his symptoms, including Chagas disease. The Chagas hypothesis is based upon Darwin’s diary, in which he narrates his experience with kissing bugs, the main vector of the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease. In this contribution, we examine the consistency of the “Chagas disease hypothesis” in the light of current ecological and epidemiological knowledge of the disease in Chile. According to his diary and letters, during his overland trips, Darwin slept in rural houses and outdoors for 128 days in a “hyperendemic” area for Chagas disease, more than exposing him to kissing bugs. This observation conveys a likely additional source of infection than previously considered, which might reinforce the idea that Chagas disease contributed to Darwin’s manifest physical deterioration.

Multi-drug resistance and biofilm production among diarrheagenic Escherichia coli pathotypes isolated from stools of children with acute diarrheal disease

Background. Diarrheagenic E. coli (DEC) is an etiological agent of childhood diarrhea. Resistance against commonly used drugs in the empirical treatment of enteric infections has increased among DEC. Relationship between antibiotic resistance and biofilm formation in microorganisms have been widely reported. This study was aimed to determine the antibiotic resistance and biofilm production pattern among DEC pathotypes isolated from stools of children aged 0–5 years with acute diarrheal disease in Abakaliki, Nigeria. Materials and methods. Diarrheal stool samples were obtained from 60 children and E. coli were isolated and identified using standard guidelines provided for laboratory diagnosis of enteric pathogens. Molecular identification was done by amplification of E. coli universal stress protein A (uspA) using polymerase chain reaction (PCR) method. Detection of virulent genes of DEC pathotypes was performed in a group of multiplex PCR using their specific primers. Kirby–Bauer disk diffusion method was used to determine the antibiotic susceptibility patterns of the isolates while biofilms production was detected by thiazolyl blue tetrazolium bromide dye in a 96-well plate. Results. DEC was isolated in 40 stools among which EIEC [40% (n = 16)] was commonly detected followed by ETEC [30% (n = 12)], EAEC [20% (n = 8)] and typical EPEC [10% (n = 4)]. Half of EAEC showed the highest multidrug resistance against ampicillin, cefoxitin, ciprofloxacin, levofloxacin, and tetracycline with the strongest biofilm production followed by all the EPEC which were resistant to ampicillin, ciprofloxacin, levofloxacin, and tetracycline with moderate biofilm production. All the LT-ETEC exhibited the least resistance to ampicillin and tetracycline with the weakest biofilm production. Conclusion. High frequency of the EIEC pathotype suggests its role as the primary etiological agent of diarrhea in children. Correlation between high drug resistance and biofilm production among the pathotype may indicate that biofilms may provide compatible uptake of resistance genes.

Molecular Characterization of Associated Pathogens in Febrile Patients during Inter-Epidemic Periods of Urban Arboviral Diseases in Tapachula Southern Mexico

Emerging and re-emerging vector-borne infections are a global public health threat. In endemic regions, fever is the main reason for medical attention, and the etiological agent of such fever is not usually identified. In this study, non-specific febrile pathogens were molecularly characterized in serum samples from 253 patients suspected of arbovirus infection. The samples were collected in the southern border region of Mexico from April to June 2015, and February to March 2016. ZIKV, CHIKV, DENV, leptospirosis, and rickettsiosis were detected by qPCR and nested PCR to identify flavivirus and alphavirus genera. The results indicated that 71.93% of the samples were positive for CHIKV, 0.79% for ZIKV, and 0.39% for DENV, with the number positive for CHIKV increasing to 76.67% and those positive for ZIKV increasing to 15.41% under the nested PCR technique. Leptospira Kmetyi was identified for the first time in Mexico, with a prevalence of 3.16%. This is the first report of ZIKV in Mexico, as well the first detection of the virus in early 2015. In conclusion, the etiological agent of fever was determined in 94% of the analyzed samples.