Hepatitis E Virus seroprevalence among cows in a rural area of southern Italy

Hepatitis E virus (HEV) is considered to be an emerging zoonotic disease, which causes numerous cases of hepatitis and deaths worldwide each year. Pigs are a host reservoir of HEV, but numerous other wild and domestic species can be infected. The aim of this study was to carry out serological screening of anti-HEV antibodies in cattle in the Sicily region (Southern Italy). Between April and December 2018, 231 serum samples were collected from cows and analysed with enzyme-linked immunosorbent assay (ELISA), for detection of HEV antibodies (IgG). The overall prevalence of anti-HEV antibodies was 36.36% (84/231; 95% CI 30-43). There were statistically significant differences in the HEV seroprevalence in animals of different ages (<11 months: 11.41%; >12 months: 39.30%; >24 months: 54.10%) (P<0.05). No statistically significant differences were detected between genders (31.37% in male and 37.38% in female) (P >0.05). This study shows that further investigation of HEV in cattle is required to understand better the epidemiology in farm animals and the potential zoonotic risks for humans. This is the first report of HEV seroprevalence for cows in Italy, which provides baseline data for further studies and for control of HEV infection in cattle.

A Review of Coccidioides Research, Outstanding Questions in the Field, and Contributions by Women Scientists

Purpose of Review Coccidioidomycosis is an infectious disease that gained clinical significance in the early 20th century. Many of the foundational contributions to coccidioidomycosis research, including the discovery of the fungal disease agent, Coccidioides spp., were made by women. We review recent progress in Coccidioides research and big questions remaining in the field, while highlighting some of the contributions from women. Recent Findings New molecular-based techniques provide a promising method for detecting Coccidioides, which can help determine the dominate reservoir host and ideal environmental conditions for growth. Genetic and genomic analyses have allowed an understanding of population structure, species level diversity, and evolutionary histories. We present a current, comprehensive genome list, where women contributed many of these entries. Several efforts to develop a coccidioidomycosis vaccine are underway. Summary Women continue to pioneer research on Coccidioides, including the relationships between the fungi and the environment, genetics, and clinical observations. Significant questions remain in the field of Coccidioides, including the main host reservoir, the relationships between genotypic and phenotypic variation, and the underlying cause for chronic clinical coccidioidomycosis cases.

Seroprevalence of Toxoplasma gondii in Wild Rats (Rattus rattus) in Northern Iran

Rodents are considered as reservoir hosts for various pathogens (such as Toxoplasma gondii) and have been revealed to play an important role in the spread of several infectious diseases to humans and other animals. The aim of this investigation was to survey the prevalence of anti-T. gondii IgG antibodies in wild rats in Northern Iran. One hundred rats were caught using rat traps set in different areas in Northern Iran (September 2017). The thoracic cavity of each rat was opened, and then the blood sample was collected from the heart. IgG anti-Toxoplasma gondii antibodies were detected using the modified agglutination test (MAT) with a cutoff value equal to 1 : 40. Overall, 56% of rats were infected by T. gondii. Considering the sex of rats, 45% of male and 55% of female rats were seropositive, but the differences were not statistically significant. There was a significant difference between seropositivity and habitat types and age of rodents. Our findings have public health implications and confirm the high seroprevalence of T. gondii infection in northern Iran. The study established that wild rats represent an important and persistent wildlife intermediate host reservoir for T. gondii.

Genomic characterization of Listeria spp. isolated from wild deer and boars’ tonsils

Listeria monocytogenes (Lm) is a major human and animal foodborne pathogen. However, data from environmental reservoirs remain scarce. Here, we used whole genome sequencing to characterize Listeria spp. isolates recovered over one year from wild animals in their natural habitats in Spain. Three different Listeria spp. [Lm (n=19), Listeria ivanovii subsp. londoniensis (Liv, n=4) and Listeria innocua (Lin, n=3)] were detected in 23 animal tonsils (9 deer, 14 wild boars) and 2 feeding throughs. No Listeria spp. was detected in feces. Lm was detected in tonsils of 44.4% (8 out of 18) deer and 40.7% (11 out of 27) wild boars. Lm isolates belonged to 3 different cgMLST types (CTs) of 3 distinct sublineages (SL1, SL387 and SL155) from lineages I and II. While cgMLST type L1-SL1-ST1-CT5279 (IVb, CC1) occurred only in one animal, types L1-SL387-ST388-CT5239 (IVb, CC388) and L2-SL155-ST155-CT1170 (IIa, CC155) were retrieved from multiple animals. In addition, L1-SL387-ST388-CT5239 (IVb, CC388) isolates were collected 1 year apart, revealing its long-term occurrence within the animal population and/or environmental reservoir. The presence of identical Lm strains in deer and wild boars suggest contamination from a common food or environmental source, although interhost transmission cannot be excluded. Pathogenicity islands were present in 100% (LIPI-1), 5% (LIPI-3) and 79% (LIPI-4) of the Lm isolates and all Lm lineage II isolates (n=3) carried SSI-1 stress islands. This study highlights the need for monitoring Lm environmental contamination and the importance of tonsils as a possible Lm intra-host reservoir. Importance: Listeria monocytogenes (Lm) is a foodborne bacterial pathogen responsible for listeriosis. Whole genome sequencing has been extensively used in public health and food industries to characterize circulating Listeria isolates, but genomic data on isolates occurring in natural environments and wild animals is still scarce. Here, we show that wild animals carry pathogenic Listeria and that the same genotypes can be found at different time points in different host species. This work highlights the need of Listeria spp. monitoring of environmental contamination and the importance of tonsils as a possible Lm intra-host reservoir.

Unique nCoV-2019 (COVID 19) spike glycoprotein processing by host protease: Analysis and Implication on infection

: The current global pandemic outbreak of a novel type of corona virus termed by World Health Organization as COVID-19 became an grave concern and worry to human health and world economy. Intense research efforts are now underway worldwide to combat and prevent the spread of this deadly disease. This zoonotic virus, a native to bat population is most likely transmitted to human via a host reservoir. Due to its close similarity to previously known SARS CoV (Severe Acute Respiratory Syndrome Corona Virus) of 2002 and related MERS CoV (Middle East Respiratory Syndrome Corona Virus) of 2012, it is also known as SARS CoV2. But unlike them it is far too infectious, virulent and lethal. Among its various proteins, the surface spike glycoprotein “S” has drawn significant attention because of its implication in viral recognition and host-virus fusion process. A detail comparative analysis of “S” proteins of SARS CoV (now called SARS CoV1), SARS CoV2 (COVID-19) and MERS CoV based on structure, sequence alignment, host cleavage sites, receptor binding domains, potential glycosylation and Cys-disulphide bridge locations has been performed. It revealed some key features and variations that may elucidate the high infection and virulence character of COVID-19. Moreover this crucial information may become useful in our quest for COVID-19 therapeutics and vaccines.

Seroprevalence of Nipah Virus Infection in Peninsular Malaysia

Nipah virus (NiV) outbreak occurred in Malaysia in 1998. The natural host reservoir for NiV is Pteropus bats, which are commonly found throughout Malaysia. Humans become infected when NiV spills over from the reservoir species. In this study, NiV serosurveillance in Peninsular Malaysia, particularly among the indigenous population, was performed. The collected samples were tested for presence of NiV antibodies using a comparative indirect enzyme-linked immunosorbent assay based on the recombinant NiV nucleocapsid (rNiV-N) protein. We found that 10.73% of the participants recruited in this study had antibodies against rNiV-N, suggesting possible exposure to NiV.

First Presentation of the Complete Infection Cycle of Visceralizing Leishmania infantum/ donovani Hybrid Strain in Turkey: The Host, Reservoir and Vector

Objective: Visceral Leishmaniasis (VL) is a widespread infectious disease of the reticuloendothelial system which is mostly caused by Leishmania infantum and L.donovani. VL is a zoonotic infection and dogs act as the main reservoirs of the disease while the vectors are the female Phlebotomus, that is to say, sandflies. Although Leishmania spp. are attributed to reproduce asexually, the genetic exchange between different strains has recently been demonstrated and causes interspecific hybrids. We aimed to present the complete infection cycle of a hybrid strain of Leishmania infantum/donovani with the host, reservoir, and vector. Materials and Methods: A patient presenting with VL proved to have a dog with canine leishmaniasis. Bone marrow aspirate from the patient and lymph node aspirates from the dog were inspected for Leishmania spp. amastigotes under light microscopy. Samples were cultured in enriched NNN medium. Serological examinations were made using IFAT for the patient serum and rK39 test for both human and dog samples. Light traps were placed to collect Phlebotomus. Leishmania molecular identification was executed by primers and probes specific to ITS-1 and cytochrome B gene region of Leishmania parasites. Results: Leishmania spp. amastigotes were detected in the slides while promastigotes were present in the enriched NNN medium. For patient serum, IFAT IgG was 1/256 positive, and rK39 was positive for both dog and human samples. Fifty-two Phlebotomus were caught (24 male, 28 female): 35 of them were P. similis, ten were P. neglectus/syriacus, six were P .papatasi, and one was P. tobbi. Molecular analysis showed that the Leishmania spp. isolates from the patient, dog, and P.tobbi were identical. Gel image revealed two bands in all three samples, thus leading to the conclusion that the infecting strain was a hybrid of L. infantum and L. donovani. Conclusion: We found identical isolates that are putative hybrids of L. donovani and L. infantum in human, dog reservoir and sandfly.. Keywords: Leishmaniasis, Phlebotomus, Hybrid, Epidemiology, Migration, Turkey

MODELLING THE PROCESS OF SALTWATER PENETRATION FROM THE TAGANROG BAY AT THE MOUTH OF THE DON

The description of a complex mathematical model of the flow and distribution of salt in an open riverbed is given. We consider the channel of the Don River, consisting of the Stary Don and the main channel. Salt is delivered through the host reservoir, the Taganrog Bay. The model is described by the system of Saint-Venant equations and the convectiondiffusion equation. The problem is solved by finite-difference methods. The results of a numerical study of the influence of the water surface level in the Taganrog Bay on the nature of the flow in the delta part of the Don, as well as on the degree of salt penetration upstream of the river, are obtained. It has been numerically established that the flow rate does not significantly affect the salt concentration in the main Don channel. Computational experiments have shown that the decisive factor in the supply of saline water from the Taganrog Bay to the Don Delta is a significant increase in the water level due to extreme wind surges, and the preceding runoffs further enhance this effect. The presented model gives an idea of the general trend in the development of the process of possible salinization of the Don Delta with surge phenomena.

Genome-Wide Identification of Host-Segregating Epidemiological Markers for Source Attribution in Campylobacter jejuni

ABSTRACT Campylobacter is among the most common worldwide causes of bacterial gastroenteritis. This organism is part of the commensal microbiota of numerous host species, including livestock, and these animals constitute potential sources of human infection. Molecular typing approaches, especially multilocus sequence typing (MLST), have been used to attribute the source of human campylobacteriosis by quantifying the relative abundance of alleles at seven MLST loci among isolates from animal reservoirs and human infection, implicating chicken as a major infection source. The increasing availability of bacterial genomes provides data on allelic variation at loci across the genome, providing the potential to improve the discriminatory power of data for source attribution. Here we present a source attribution approach based on the identification of novel epidemiological markers among a reference pan-genome list of 1,810 genes identified by gene-by-gene comparison of 884 genomes of Campylobacter jejuni isolates from animal reservoirs, the environment, and clinical cases. Fifteen loci involved in metabolic activities, protein modification, signal transduction, and stress response or coding for hypothetical proteins were selected as host-segregating markers and used to attribute the source of 42 French and 281 United Kingdom clinical C. jejuni isolates. Consistent with previous studies of British campylobacteriosis, analyses performed using STRUCTURE software attributed 56.8% of British clinical cases to chicken, emphasizing the importance of this host reservoir as an infection source in the United Kingdom. However, among French clinical isolates, approximately equal proportions of isolates were attributed to chicken and ruminant reservoirs, suggesting possible differences in the relative importance of animal host reservoirs and indicating a benefit for further national-scale attribution modeling to account for differences in production, behavior, and food consumption. IMPORTANCE Accurately quantifying the relative contribution of different host reservoirs to human Campylobacter infection is an ongoing challenge. This study, based on the development of a novel source attribution approach, provides the first results of source attribution in Campylobacter jejuni in France. A systematic analysis using gene-by-gene comparison of 884 genomes of C. jejuni isolates, with a pan-genome list of genes, identified 15 novel epidemiological markers for source attribution. The different proportions of French and United Kingdom clinical isolates attributed to each host reservoir illustrate a potential role for local/national variations in C. jejuni transmission dynamics.