According to controversial theories and results of studies, foods with animal origins play an important role in the transmission of H. pylori to human. The aim of this study was to determine the distribution of vacA genotypes of H. pylori, isolated from milk and meat samples of cow, sheep, goat, camel, and buffalo. Eight hundred and twenty raw milk and meat samples were collected from various parts of Iran. Samples were cultured and those found positive for H. pylori were analyzed for the presence of various genotypes of vacA gene. Out of 420 milk and 400 meat samples, 92 (21.90%) and 105 (26.25%) were positive for H. pylori, respectively. The most commonly detected genotypes in the vacA gene were s1a (86.80%), m1a (79.18%), s1b (69.54%), and m1b (63.45%) and detected combined genotypes were mostly m1as1a (68.52%), m1as1b (60.40%), m1bs1b (55.83%), and m1bs1a (53.29%). High presence of bacteria in the milk and meat samples of sheep represents that sheep may be the natural host of H. pylori. High presence of H. pylori strains in milk and meat samples similar to vacA genotypes in human being suggests that milk and meat samples could be the sources of bacteria for human.

COVID-19 is considered as the third human coronavirus and has a high potential for transmission. Fast public health interventions through antibodies, anti-virals or novel vaccine strategies to control the virus and disease transmission have been extremely followed. SARS-CoV-2 shares about 79% genomic similarity with SARS-CoV and approximately 50% with MERS-CoV. Based on these similarities, prior knowledge in treating SARS-CoV and MERS-CoV can be used as the basis of majority of the alternatives for controlling SARS-CoV-2. Immunotherapy is an effective strategy for clinical treatment of infectious diseases such as SARS-CoV-2. Passive antibody therapy, which decreases the virus replication and disease severity, is assessed as an effective therapeutic approach to control SARS-CoV-2 epidemics. The close similarity between SARS-CoV-2 genome with the SARS-CoV genome caused both coronaviruses to bind to the same angiotensin-converting enzyme 2 (ACE2) receptors that found in the human lung. There are several strategies to develop SARS-CoV-2 vaccines, which the majority of them are based on those developed previously for SARS-CoV. The interaction between the spike (S) protein of SARS-CoV-2 and ACE2 on the host cell surface leads to the initiation of SARS-CoV-2 infection. S protein, which is the main inducer of neutralizing antibodies, has been targeted by most of these strategies. Vaccines that induce an immune response against the S protein to inhibit its binding with the host ACE2 receptor, can be considered as effective vaccines against SARS-CoV-2. Here, we aimed to review frontier therapeutics and vaccination strategies for SARS-CoV-2 (COVID-19).

To understand how the nervous system develops from a small pool of progenitors during early embryonic development, it is fundamentally important to identify the diversity of neuronal subtypes, decode the origin of neuronal diversity, and uncover the principles governing neuronal specification across different regions. Recent single-cell analyses have systematically identified neuronal diversity at unprecedented scale and speed, leaving the deconstruction of spatiotemporal mechanisms for generating neuronal diversity an imperative and paramount challenge. In this review, we highlight three distinct strategies deployed by neural progenitors to produce diverse neuronal subtypes, including predetermined, stochastic, and cascade diversifying models, and elaborate how these strategies are implemented in distinct regions such as the neocortex, spinal cord, retina, and hypothalamus. Importantly, the identity of neural progenitors is defined by their spatial position and temporal patterning factors, and each type of progenitor cell gives rise to distinguishable cohorts of neuronal subtypes. Microenvironmental cues, spontaneous activity, and connectional pattern further reshape and diversify the fate of unspecialized neurons in particular regions. The illumination of how neuronal diversity is generated will pave the way for producing specific brain organoids to model human disease and desired neuronal subtypes for cell therapy, as well as understanding the organization of functional neural circuits and the evolution of the nervous system.

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The aim of the present study was to determine the incidence of Shiga toxin producing Escherichia coli, its virulence factors, O-serogroups and antimicrobial resistance properties in various types of food stuffs in Iran. All samples were cultured and those that were E. coli positive were subjected to PCR. Of 801 samples studied, 123 (15.35%) were positive for STEC strains. Samples collected in summer season had the higher prevalence of bacteria (49.59%). Beef meat was the most commonly contaminated sample (24.28%). The stx1 was the most commonly detected, while ehly was the least. The most commonly detected serogroups in the STEC strains recovered from the food samples were O157 (27.64%) and O26 (21.95%). The serogroup of 17.07% of STEC strains cannot be detected by means of the O-serogroup primers. The most commonly detected antibiotic resistance genes were blaSHV (47.15%) and aadA1 (44.71%). STEC strains of our investigation harbored the highest levels of resistance against ampicillin (100%), gentamycin (70.73%) and tetracycline (62.60%). Observation of proper monitoring, principles of food hygiene and accurate antibiotic prescription reduce the risk of diseases caused by STEC strains in human. Practical applicationsWe found E. coli bacteria with defined pathotypes which originates mainly from human and animal sources in various types of food samples of Iranian markets. We also identified a large numbers of virulent and resistant strains of E. coli with higher prevalence of stx1 and eaeA gene, O157 and O26 serogroups, CITM and aac(3)-IV antibiotic resistance genes and resistance to ampicillin, penicillin and gentamycin antibiotics. Beef meat had the highest prevalence. Simultaneous presence of stx1 and eaeA and stx2 and eaeA virulence factors in some strains of E. coli bacterium in food stuffs indicated the important public health problem. Using from microbiological tests can contribute to reducing the microbial load in food stuffs. Controlling sources of human and animal fecal pollution, such as managing the quality of primary ingredients, staffs and devices are other approaches to reduce the prevalence of STEC in food stuffs. Using from the disk diffusion method and avoiding from the irregular and excessive prescription of antibiotics are two important approaches to reduce the levels of antibiotic resistance. K E Y W O R D S antimicrobial resistance properties, food stuffs, Iran, O-serogroups, Shiga toxin producing Escherichia coli, virulence factors