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The Shiga toxin producing Escherichia coli (STEC) are considered to be one of the most important groups of emerging public health pathogens with cattle being the main reservoir. The objective of this study was to isolate and characterise Escherichia coli Shiga toxins in dairy cattle farms. A total of 252 faeces samples were collected from healthy cows belonging to 37 farms. PCR screening of samples for the common sequences of stx1/stx2 genes and stx1 and stx2 genes resulted in a STEC faecal excretion prevalence of 59.5% at the farm level and 26.6% at the individual level. Among positive animals, 85.1% carried STEC with a single stx1 gene and 14.9% with the stx1 and stx2 genes. Immunomagnetic separation was performed on 40 PCR-positive samples (10/10 positive for the stx1 and stx2 genes and 30/57 positive only for stx1). Biochemical identification revealed the presence of 66 E. coli strains (27.5%). The search for virulence genes on these strains by PCR showed that only twenty-two (33.33%) were STEC. The presence of the stx1, stx2, ehx and eae genes was characterised in 30.3%, 4.54%, 13.63% and 1.51% of the strains, respectively, indicating that the virulotype with stx alone was dominant. Serological identification showed the absence of O157 sero-groups and the presence of O1(2), O2, O18(2), O128 sero-groups. The susceptibility testing of STEC showed 68.18% resistance to chloramphenicol, 63.64% to neomycin, 59.1% to ampicillin, 22.73% to trimethoprim + sulfamethoxazole and 9.1% to amoxicillin + clavulanic acid and nalidixic acid. Four strains showed multi-resistance. Bovine carriage of STEC constitutes a public health risk by contamination of milk and meat. To protect human health, it is necessary to limit the bovine STEC shedding. [ABSTRACT FROM AUTHOR]

Avian Alpha-influenza-virus (AIV) massively affects poultry, targeting mainly the respiratory tract for virus replication. Recently, two major H5N8 and H5N1 outbreaks caused tremendous losses in Algerian poultry. The clinical symptoms that had not been seen in the past didn't prompt a rapid reaction to control the epidemics. We report here the characteristics of these outbreaks and the epidemiological status of AIV in Algeria. Following autopsy observation samples from target organs were taken and analyzed by the classical real-time reverse transcription polymerase chain reaction (RRT-PCR). Specific PCR HA and NA identification was used for subtyping H5 and N1/N8 genes. Systemic damage was observed in the upper-respiratory tracts with hemorrhagic and congestive tracheas, lungs, proventriculus, gut, and cecal tonsils were bloody. Out of 77 positive cases 13 were H5N8, 8 H5N1, and 10 H5Nx strains. These findings raise questions about the strain's pathotype considering severe organ damage and high mortality., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Aflatoxin (AF)-producing fungi such as Aspergillus flavus commonly contaminate animal feeds, causing high economic losses. A. flavus is the most prevalent and produces AFB1, a potent mutagen, and carcinogen threatening human and animal health. Aspergillaceae is a large group of closely related fungi sharing number of morphological and genetic similarities that complicate the diagnosis of highly pathogenic strains. We used here morphological and molecular assays to characterize fungal isolates from animal feeds in Southwestern Algeria. These tools helped to identify 20 out of 30 Aspergillus strains, and 15 of them belonged to the Aspergillus section Flavi . Further analyses detected four out of 15 as belonging to Aspergillus flavus-parasiticus group. PCR targeting the AF genes' aflR-aflS(J) intergenic region amplified a single 674 bp amplicon in all four isolates. The amplicons were digested with a Bgl II endonuclease, and three specific fragments were observed for A. flavus but A. parasitucus lacked two typical fragments. Sequencing data of four amplicons confirmed the presence of the two Bgl II restriction sites yielding the three fragments, confirming that all four strains were A. flavus . In addition, this analysis illustrated the genetic variability within the A. flavus strains., (© 2022 Hadjer Saber et al., published by Sciendo.)

Animal lentiviruses (LVs) have been proven to have the capacity to cross the species barrier, to adapt in the new hosts, and to increase their pathogenesis, therefore leading to the emergence of threatening diseases. However, their potential for widespread diffusion is limited by restrictive cellular factors that block viral replication in the cells of many species. In previous studies, we demonstrated that the restriction of CAEV infection of sheep choroid plexus cells was due to aberrant post-translation cleavage of the CAEV Env gp170 precursor. Later, we showed that the lack of specific receptor(s) for caprine encephalitis arthritis virus (CAEV) on the surface of human cells was the only barrier to their infection. Here, we examined whether small ruminant (SR) cells can support the replication of primate LVs. Three sheep and goat cell lines were inoculated with cell-free HIV-1 and SIVmac viral stocks or transfected with infectious molecular clone DNAs of these viruses. The two recombinant lentiviral clones contained the green fluorescent protein (GFP) reporter sequence. Infection was detected by GFP expression in target cells, and the infectious virus produced and released in the culture medium of treated cells was detected using the indicator TZM-bl cell line. Pseudotyped HIV-GFP and SIV-GFP with vesicular stomatitis virus G glycoprotein (VSV-G) allowed the cell receptors to be overcome for virus entry to further evaluate the viral replication/restriction in SR cells. As expected, neither HIV nor SIV viruses infected any of the SR cells. In contrast, the transfection of plasmid DNAs of the infectious molecular clones of both viruses in SR cells produced high titers of infectious viruses for human indicators, but not SR cell lines. Surprisingly, SR cells inoculated with HIV-GFP/VSV-G, but not SIV-GFP/VSV-G, expressed the GFP and produced a virus that efficiently infected the human indictor, but not the SR cells. Collectively, these data provide a demonstration of the lack of replication of the SIVmac genome in SR cells, while, in contrast, there was no restriction on the replication of the IV-1 genome in these cells. However, because of the lack of functional receptors to SIVmac and HIV-1 at the surface of SR cells, there is specific lentiviral entry.

HIV-1 remains a major public health issue worldwide in spite of efficacious antiviral therapies, but with no cure or preventive vaccine. The latter has been very challenging, as virus infection is associated with numerous escape mechanisms from host specific immunity and the correlates of protection remain incompletely understood. We have developed an innovative vaccine strategy, inspired by the efficacy of live-attenuated virus, but with the safety of a DNA vaccine, to confer both cellular and humoral responses. The CAL-SHIV-IN - lentiDNA vaccine comprises the backbone of the pathogenic SHIV KU2 genome, able to mimic the early phase of viral infection, but with a deleted integrase gene to ensure safety precluding integration within the host genome. This vaccine prototype, constitutively expressing viral antigen under the CAEV LTR promoter, elicited a variety of vaccine-specific, persistent CD4 and CD8 T cells against SIV-Gag and Nef up to 80 weeks post-immunization in cynomolgus macaques. Furthermore, these specific responses led to antiviral control of the pathogenic SIV mac251 . To further improve the efficacy of this vaccine, we incorporated the IL-7 or IL-15 genes into the CAL-SHIV-IN - plasmid DNA in efforts to increase the pool of vaccine-specific memory T cells. In this study, we examined the immunogenicity of the two co-injected lentiDNA vaccines CAL-SHIV-IN - IRES IL-7 and CAL-SHIV-IN - IRES IL-15 in BALB/cJ mice and rhesus macaques and compared the immune responses with those generated by the parental vaccine CAL-SHIV-IN - . This co-immunization elicited potent vaccine-specific CD4 and CD8 T cells both in mice and rhesus macaques. Antibody-dependent cell-mediated cytotoxicity (ADCC) antibodies were detected up to 40 weeks post-immunization in both plasma and mucosal compartments of rhesus macaques and were enhanced by the cytokines.

Variety of conventional vaccine strategies tested against HIV-1 have failed to induce protection against HIV acquisition or durable control of viremia. Therefore, innovative strategies that can induce long lasting protective immunity against HIV chronic infection are needed. Recently, we developed an integration-defective HIV lentiDNA vaccine that undergoes a single cycle of replication in target cells in which most viral antigens are produced. A single immunization with such lentiDNA induced long-lasting T-cell and modest antibody responses in cynomolgus macaques. Here eighteen months after this single immunization, all animals were subjected to repeated low dose intra-rectal challenges with a heterologous pathogenic SIVmac251 isolate. Although the viral set point in SIVmac-infected cynomolgus is commonly lower than that seen in Indian rhesus macaques, the vaccinated group of macaques displayed a two log reduction of peak of viremia followed by a progressive and sustained control of virus replication relative to control animals. This antiviral control correlated with antigen-specific CD4+ and CD8+ T cells with high capacity of recall responses comprising effector and central memory T cells but also memory T cell precursors. This is the first description of SIV control in NHP model infected at 18 months following a single immunization with a non-integrative single cycle lentiDNA HIV vaccine. While not delivering sterilizing immunity, our single immunization strategy with a single-cycle lentivector DNA vaccine appears to provide an interesting and safe vaccine platform that warrants further exploration., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020. Published by Elsevier Ltd.)

Retroviral integrase (IN) proteins catalyze the permanent integration of the viral genome into host DNA. They can productively recruit cellular proteins, and the human Bromodomain and Extra-Terminal domain (hBET) proteins have been shown to be co-factors for integration of gamma-retroviruses such as Murine Leukemia Virus (MLV) into human cells. By using two-hybrid, co-immunoprecipitation and in vitro interaction assays, we showed that IN of the gamma- Porcine Endogenous Retrovirus-A/C (PERV IN) interacts through its C-terminal domain (CTD) with hBET proteins. We observed that PERV IN interacts with the BRD2, BRD3 and BRD4 proteins in vitro and that the BRD2 protein specifically binds and co-localizes with PERV IN protein in the nucleus of cells. We further mapped the interaction sites to the conserved Extra-Terminal (ET) domain of the hBET proteins and to several amino acids of the of the C-terminal tail of the PERV IN CTD. Finally, we determined the first experimental structure of an IN CTD - BET ET complex from small-angle X-ray scattering data (SAXS). We showed that the two factors assemble as two distinct modules linked by a short loop which confers partial flexibility. The SAXS-restrained model is structurally compatible with the binding of the PERV intasome to BRD2. Altogether, these data confirm the important role of host BET proteins in the gamma-retroviruses' targeting site and efficiency of integration., (Copyright © 2019. Published by Elsevier Inc.)

Introduction: Infection of goats with caprine arthritis encephalitis virus (CAEV) has been detected in variable proportions in many countries all over the world. Here, we investigated the seroprevalence of CAEV in goats raised in Algeria., Material and Methods: A serological survey was performed on serum samples from 1,313 goats, including the local breeds (Arabia and Dwarf of Kabylia) and imported European breeds (Alpine and Saanen). Blood samples were taken from goats on 38 farms distributed across four different geographical regions of Algeria. Serum samples were tested for CAEV antibodies using a commercial ELISA., Results: A total of 390 serum samples were found to be positive for CAEV, giving an overall seropositivity rate of 29.7% in individual animals and 97.37% (37/38) at the goat farm level., Conclusion: These results provide the first large-scale serological evidence for the presence of CAEV infection in both the local and imported breeds of goats raised in Algeria, indicating that the virus infection is widespread., Competing Interests: Conflict of Interest Conflict of Interests Statement: The authors declare that there is no conflict of interests regarding the publication of this article.

Breast cancer is the common malignancy that affects women worldwide, but conventional risk factors account for only a small proportion of these cases. A possible viral etiology for breast cancer has been proposed and Epstein-Barr virus (EBV) is a widely studied candidate virus. The objective of this study is to determine the association of EBV infection with infiltrating ductal carcinomas (IDC). This descriptive study was carried out in the laboratory of developmental biology and differentiation, from 2012 to 2014. Of 39 cases, we determined the clinicopathological characteristics of the population. Of the 23 cases of IDC, we implemented the techniques Elisa, immunohistochemistry and in situ hybridization. To determine the serological profile, overexpression of onco-proteins EBNA-1, HER2, the mitotic index Ki67 and detection of the presence of the viral genome. The mean age is 57.40±4, SBR II predominates with 70%, pN+ (27%), RE+ (58%), RP+ (52%), HER2 (81%), Luminal A (34%), Luminal B (14%), HER2 (24%), and triple negative (28%). The serological profile of IgG VCA + in IgG EBNA-1 (87%), EBNA-1 P79 (82%) with a positive relationship between the IgG EBNA-1 and EBNA-1 P79 serology profile (p=0.001), HER2 (p=0.003) and with the molecular profile (p=0.051), EBNA-1 overexpression in (13%). The viral genome (EBER) is found in the tumors 43% representing an inverse relationship with the overexpression of Ki67 and a positive relationship with the overexpression of HER2. In our study we found an association with the presence of the EBV virus and the IDC studied.

The emergence of human immunodeficiency virus (HIV) causing acquired immunodeficiency syndrome (AIDS) in infected humans has resulted in a global pandemic that has killed millions. HIV-1 and HIV-2 belong to the lentivirus genus of the Retroviridae family. This genus also includes viruses that infect other vertebrate animals, among them caprine arthritis-encephalitis virus (CAEV) and Maedi-Visna virus (MVV), the prototypes of a heterogeneous group of viruses known as small ruminant lentiviruses (SRLVs), affecting both goat and sheep worldwide. Despite their long host-SRLV natural history, SRLVs were never found to be responsible for immunodeficiency in contrast to primate lentiviruses. SRLVs only replicate productively in monocytes/macrophages in infected animals but not in CD4+ T cells. The focus of this review is to examine and compare the biological and pathological properties of SRLVs as prototypic Tat-independent lentiviruses with HIV-1 as prototypic Tat-dependent lentiviruses. Results from this analysis will help to improve the understanding of why and how these two prototypic lentiviruses evolved in opposite directions in term of virulence and pathogenicity. Results may also help develop new strategies based on the attenuation of SRLVs to control the highly pathogenic HIV-1 in humans.

Novel HIV vaccine vectors and strategies are needed to control HIV/AIDS epidemic in humans and eradicate the infection. DNA vaccines alone failed to induce immune responses robust enough to control HIV-1. Development of lentivirus-based DNA vaccines deficient for integration and with a limited replication capacity is an innovative and promising approach. This type of vaccine mimics the early stages of virus infection/replication like the live-attenuated viruses but lacks the inconvenient integration and persistence associated with disease. We developed a novel lentivector DNA vaccine "CAL-SHIV-IN(-)" that undergoes a single round of replication in the absence of integration resulting in augmented expression of vaccine antigens in vivo. Vaccine gene expression is under control of the LTRs of a naturally attenuated lentivirus, Caprine arthritis encephalitis virus (CAEV) the natural goat lentivirus. The safety of this vaccine prototype was increased by the removal of the integrase coding sequences from the pol gene. We examined the functional properties of this lentivector DNA in cell culture and the immunogenicity in mouse models. Viral proteins were expressed in transfected cells, assembled into viral particles that were able to transduce once target permissive cells. Unlike the parental replication-competent SHIV-KU2 that was detected in DNA samples from any of the serial passage infected cells, CAL-SHIV-IN(-) DNA was detected only in target cells of the first round of infection, hence demonstrating the single cycle replication of the vaccine. A single dose DNA immunization of humanized NOD/SCID/β2 mice showed a substantial increase of IFN-γ-ELISPOT in splenocytes compared to the former replication and integration defective Δ4SHIV-KU2 DNA vaccine., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Prevention of HIV acquisition and replication requires long lasting and effective immunity. Given the state of HIV vaccine development, innovative vectors and immunization strategies are urgently needed to generate safe and efficacious HIV vaccines. Here, we developed a novel lentivirus-based DNA vector that does not integrate in the host genome and undergoes a single-cycle of replication. Viral proteins are constitutively expressed under the control of Tat-independent LTR promoter from goat lentivirus. We immunized six macaques once only with CAL-SHIV-IN- DNA using combined intramuscular and intradermal injections plus electroporation. Antigen-specific T cell responses were monitored for 47 weeks post-immunization (PI). PBMCs were assessed directly ex vivo or after 6 and 12 days of in vitro culture using antigenic and/or homeostatic proliferation. IFN-γ ELISPOT was used to measure immediate cytokine secretion from antigen specific effector cells and from memory precursors with high proliferative capacity (PHPC). The memory phenotype and functions (proliferation, cytokine expression, lytic content) of specific T cells were tested using multiparametric FACS-based assays. All immunized macaques developed lasting peripheral CD8+ and CD4+ T cell responses mainly against Gag and Nef antigens. During the primary expansion phase, immediate effector cells as well as increasing numbers of proliferating cells with limited effector functions were detected which expressed markers of effector (EM) and central (CM) memory phenotypes. These responses contracted but then reemerged later in absence of antigen boost. Strong PHPC responses comprising vaccine-specific CM and EM T cells that readily expanded and acquired immediate effector functions were detected at 40/47 weeks PI. Altogether, our study demonstrated that a single immunization with a replication-limited DNA vaccine elicited persistent vaccine-specific CM and EM CD8+ and CD4+ T cells with immediate and readily inducible effector functions, in the absence of ongoing antigen expression.