Pneumonic Plague Protection Induced by a Monophosphoryl Lipid A Decorated Yersinia Outer-Membrane-Vesicle Vaccine.

A new Yersinia pseudotuberculosis mutant strain, YptbS46, carrying the lpxE insertion and pmrF-J deletion is constructed and shown to exclusively produce monophosphoryl lipid A (MPLA) having adjuvant properties. Outer membrane vesicles (OMVs) isolated from YptbS46 harboring an lcrV expression plasmid, pSMV13, are designated OMV46-LcrV, which contained MPLA and high amounts of LcrV (Low Calcium response V) and displayed low activation of Toll-like receptor 4 (TLR4). Intramuscular prime-boost immunization with 30 µg of of OMV46-LcrV exhibited substantially reduced reactogenicity than the parent OMV44-LcrV and conferred complete protection to mice against a high-dose of respiratory Y. pestis challenge. OMV46-LcrV immunization induced robust adaptive responses in both lung mucosal and systemic compartments and orchestrated innate immunity in the lung, which are correlated with rapid bacterial clearance and unremarkable lung damage during Y. pestis challenge. Additionally, OMV46-LcrV immunization conferred long-term protection. Moreover, immunization with reduced doses of OMV46-LcrV exhibited further lower reactogenicity and still provided great protection against pneumonic plague. The studies strongly demonstrate the feasibility of OMV46-LcrV as a new type of plague vaccine candidate.

Engagement with Traditional Healers for Early Detection of Plague in Uganda.

In rural Uganda, many people who are ill consult traditional healers prior to visiting the formal healthcare system. Traditional healers provide supportive care for common illnesses, but their care may delay diagnosis and management of illnesses that can increase morbidity and mortality, hinder early detection of epidemic-prone diseases, and increase occupational risk to traditional healers. We conducted open-ended, semi-structured interviews with a convenience sample of 11 traditional healers in the plague-endemic West Nile region of northwestern Uganda to assess their knowledge, practices, and attitudes regarding plague and the local healthcare system. Most were generally knowledgeable about plague transmission and its clinical presentation and expressed willingness to refer patients to the formal healthcare system. We initiated a public health outreach program to further improve engagement between traditional healers and local health centers to foster trust in the formal healthcare system and improve early identification and referral of patients with plaguelike symptoms, which can reflect numerous other infectious and noninfectious conditions. During 2010-2019, 65 traditional healers were involved in the outreach program; 52 traditional healers referred 788 patients to area health centers. The diagnosis was available for 775 patients; malaria (37%) and respiratory tract infections (23%) were the most common diagnoses. One patient had confirmed bubonic plague. Outreach to improve communication and trust between traditional healers and local healthcare settings may result in improved early case detection and intervention not only for plague but also for other serious conditions.

Manganese-Based Nanoparticle Vaccine for Combating Fatal Bacterial Pneumonia.

Bacterial pneumonia is the leading cause of death worldwide among all infectious diseases. However, currently available vaccines against fatal bacterial lung infections, e.g., pneumonic plague, are accompanied by limitations, including insufficient antigen-adjuvant co-delivery and inadequate immune stimulation. Therefore, there is an urgent requirement to develop next-generation vaccines to improve the interaction between antigen and adjuvant, as well as enhance the effects of immune stimulation. This study develops a novel amino-decorated mesoporous manganese silicate nanoparticle (AMMSN) loaded with rF1-V10 (rF1-V10@AMMSN) to prevent pneumonic plague. These results suggest that subcutaneous immunization with rF1-V10@AMMSN in a prime-boost strategy induces robust production of rF1-V10-specific IgG antibodies with a geometric mean titer of 315,844 at day 42 post-primary immunization, which confers complete protection to mice against 50 × LD50 of Yersinia pestis (Y. pestis) challenge via the aerosolized intratracheal route. Mechanistically, rF1-V10@AMMSN can be taken up by dendritic cells (DCs) and promote DCs maturation through activation of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway and production of type I interferon. This process results in enhanced antigen presentation and promotes rF1-V10-mediated protection against Y. pestis infection. This manganese-based nanoparticle vaccine represents a valuable strategy for combating fatal bacterial pneumonia.

Oridonin supplementation in rabbits may help to improve the outcome of induced atherosclerosis via autophagy induction.

BACKGROUND AND AIM: Inflammation plays a crucial role in the development of atherosclerotic plague. Oridonin is the major active ingredient of the traditional Chinese medicinal herb Rabdosia rubescens. It is a natural terpenoids that is known as a strong anti-inflammatory supplement by acting as a potent inhibitor of the TXNIP/NLRP3 pathway. Hence, it can reduce the severity of inflammation and improve the outcome of atherosclerotic changes. This study aims to evaluate the anti-inflammatory effects of oridonin in the progression of atherosclerotic plague in rabbits. METHODS: Sixty-three male rabbits were included. The rabbits were randomly assigned to one of the three study groups (21 rabbits in each group), normal control diet (NC) fed normal diet for 8 weeks, atherogenic control (AC) fed atherogenic diet (2% cholesterol-enriched diet) for 8 weeks, and oridonin treated group (OT) fed atherogenic diet (2% cholesterol-enriched diet) with oridonin (purity 94%, Sigma-Aldrich, USA) at 20 mg/kg orally daily for 8 weeks. After the end of the study, blood and tissue samples were collected for analysis of various markers of inflammation and atherosclerotic plaque progression. RESULTS: Serum lipids showed a statistically significant improvement in terms of reduction in total cholesterol and low-density lipoprotein (LDL) in the OT group compared to the AC group. This was associated with a significant reduction in serum F2-isoprostane (marker of inflammation) and LC3B (marker of tissue autophagy) between the OT group compared to the AC group. There was also a significant reduction in NLRP3 inflammasome RNA expression in OT group, P<0.001. CONCLUSIONS: In animal model, with atherogenic diet, oridonin supplementation can significantly improve the outcome of atherosclerosis by its strong anti-inflammatory action.

CYP broth: a tool for Yersinia pestis isolation in ancient culture collections and field samples.

We developed a simple new selective LB-based medium, named CYP broth, suitable for recovering long-term stored Y. pestis subcultures and for isolation of Y. pestis strains from field-caught samples for the Plague surveillance. It aimed to inhibit the growth contaminating microorganisms and enrich Y. pestis growth through iron supplementation. The performance of CYP broth on microbial growth from different gram-negative and gram-positive strains from American Type Culture Collection (ATCC®) and other clinical isolates, field-caught rodent samples, and more importantly, on several vials of ancient Y. pestis subcultures was evaluated. Additionally, other pathogenic Yersinia species such as Y. pseudotuberculosis and Y. enterocolitica were also successfully isolated with CYP broth. Selectivity tests and bacterial growth performance on CYP broth (LB broth supplemented with Cefsulodine, Irgasan, Novobiocin, nystatin and ferrioxamine E) were evaluated in comparison with LB broth without additive; LB broth/CIN, LB broth/nystatin and with traditional agar media including LB agar without additive, and LB agar and Cefsulodin-Irgasan-Novobiocin Agar (CIN agar) supplemented with 50 µg/mL of nystatin. Of note, the CYP broth had a recovery twofold higher than those of the CIN supplemented media or other regular media. Additionally, selectivity tests and bacterial growth performance were also evaluated on CYP broth in the absence of ferrioxamine E. The cultures were incubated at 28 °C and visually inspected for microbiological growth analysis and O.D.625 nm measurement between 0 and 120 h. The presence and purity of Y. pestis growth were confirmed by bacteriophage and multiplex PCR tests. Altogether, CYP broth provides an enhanced growth of Y. pestis at 28 °C, while inhibiting contaminant microorganisms. The media is a simple, but powerful tool to improve the reactivation and decontamination of ancient Y. pestis culture collections and for the isolation of Y. pestis strains for the Plague surveillance from various backgrounds. KEY POINTS: • The newly described CYP broth improves the recuperation of ancient/contaminated Yersinia pestis culture collections • CYP broth was also efficient in reducing environmental contamination in field-capture samples, improving Y. pestis isolation • CYP broth can also be used for the isolation of Y. enterocolitica and Y. pseudotuberculosis.

Attenuation of Yersinia pestis fyuA Mutants Caused by Iron Uptake Inhibition and Decreased Survivability in Macrophages.

Yersinia pestis is the etiological agent of plague, a deadly infectious disease that has caused millions of deaths throughout history. Obtaining iron from the host is very important for bacterial pathogenicity. Y. pestis possesses many iron uptake systems. Yersiniabactin (Ybt) plays a major role in iron uptake in vivo and in vitro, and in virulence toward mice as well. FyuA, a ß-barrel TonB-dependent outer membrane protein, serves as the receptor for Ybt. In this study, we examined the role of the fyuA gene in Y. pestis virulence using different challenging ways and explored the underlying mechanisms. The BALB/c mouse infection assay showed that the virulence of the mutant strains (ΔfyuA and ΔfyuAGCAdel) was lower when compared with that of the wild-type (WT) strain 201. Furthermore, the attenuation of virulence of the mutant strains via subcutaneous and intraperitoneal challenges was far greater than that via intravenous injection. Iron supplementation restored lethality during subcutaneous challenge with the two mutants. Thus, we speculated that the attenuated virulence of the mutant strains toward the mice may be caused by dysfunctional iron uptake. Moreover, ΔfyuA and ΔfyuAGCAdel strains exhibited lower survival rates in murine RAW264.7 macrophages, which might be another reason for the attenuation. We further explored the transcriptomic differences between the WT and mutant strains at different temperatures and found that the expressions of genes related to Ybt synthesis and its regulation were significantly downregulated in the mutant strains. This finding indicates that fyuA might exert a regulatory effect on Ybt. Additionally, the expressions of the components of the type III secretion system were unexpectedly upregulated in the mutants, which is inconsistent with the conventional view that the upregulation of the virulence genes enhances the virulence of the pathogens.

Mahamari Plague: Rats, Colonial Medicine and Indigenous Knowledge in Kumaon and Garhwal, India.

Colonial approaches to animal and zoonotic diseases are often scrutinized in terms of their recognition or dismissal of indigenous knowledge. In this article I examine British colonial approaches to "Mahamari plague" in mid-nineteenth century Kumaon and Garhwal, in the Indian Himalayas. Discussing two key colonial medical expeditions in the region, I argue that the eventual recognition of the validity of Kumaoni and Garhwali knowledge of Mahamari and its relation to rats intensified intrusive colonial intervention on indigenous lifeways. I examine this neglected impact of the colonial recognition of indigenous knowledge and urge for approaches that place more emphasis on the practical impact of colonial epistemologies.

Assessing the origins of the European Plagues following the Black Death: A synthesis of genomic, historical, and ecological information.

The second plague pandemic started in Europe with the Black Death in 1346 and lasted until the 19th century. Based on ancient DNA studies, there is a scientific disagreement over whether the bacterium, Yersinia pestis, came into Europe once (Hypothesis 1) or repeatedly over the following four centuries (Hypothesis 2). Here, we synthesize the most updated phylogeny together with historical, archeological, evolutionary, and ecological information. On the basis of this holistic view, we conclude that Hypothesis 2 is the most plausible. We also suggest that Y. pestis lineages might have developed attenuated virulence during transmission, which can explain the convergent evolutionary signals, including pla decay, that appeared at the end of the pandemics.

Regarding pandemics: Ibn Jatima from Almería anticipates the physiopathological concept of multi-organ failure in the 14th century.

In 1348, a pandemic known as Black Death devastated humanity and changed social, economic and geopolitical world order, as is the current case with SARS-CoV-2 coronavirus. The doctor of the Nasrid Kingdom of Granada, Ibn-Jatima from Almeria, wrote "Treatise on the Plague", in which it may be found epidemiological and clinical similarities between both plagues. In the context of Greco-Arab medicine, he discovered respiratory and contact contagion of Pestis and attributed its physiopathology to a lack of pulmonary cooling of the innate heat, generated in the heart and carried by the blood humor. The process described was equivalent to the oxygen transport system. Furthermore, it was supposed to generate toxic residues, such as free radicals, leading to an irreversible multiple organ failure (MOF), considered a mortality factor as in Covid-19. Due to its similitude, it would be the first antecedent of the MOF physiopathological concept, a finding that enriches the scientific and historical heritage of our clinical specialty.

Antibiotic Therapy of Plague: A Review.

Plague-a deadly disease caused by the bacterium Yersinia pestis-is still an international public health concern. There are three main clinical forms: bubonic plague, septicemic plague, and pulmonary plague. In all three forms, the symptoms appear suddenly and progress very rapidly. Early antibiotic therapy is essential for countering the disease. Several classes of antibiotics (e.g., tetracyclines, fluoroquinolones, aminoglycosides, sulfonamides, chloramphenicol, rifamycin, and ß-lactams) are active in vitro against the majority of Y. pestis strains and have demonstrated efficacy in various animal models. However, some discrepancies have been reported. Hence, health authorities have approved and recommended several drugs for prophylactic or curative use. Only monotherapy is currently recommended; combination therapy has not shown any benefits in preclinical studies or case reports. Concerns about the emergence of multidrug-resistant strains of Y. pestis have led to the development of new classes of antibiotics and other therapeutics (e.g., LpxC inhibitors, cationic peptides, antivirulence drugs, predatory bacteria, phages, immunotherapy, host-directed therapy, and nutritional immunity). It is difficult to know which of the currently available treatments or therapeutics in development will be most effective for a given form of plague. This is due to the lack of standardization in preclinical studies, conflicting data from case reports, and the small number of clinical trials performed to date.

Are we Athens or Florence? COVID-19 in historical context.

We have been here before. In 430 BCE, a plague struck Athens, killing as much as 25% of the population. In 1347 CE, the bubonic plague afflicted western Europe for 4 years, killing as much as 50% of the population. The plague of Athens led to a collapse of their religion, cultural norms and democracy. In contrast, the bubonic plague led eventually to the Renaissance, a growth of art, science and humanism. As we contend with the COVID-19 global pandemic, will we become Athens or Florence?

[The epidemic and prevention of plagues in modern Shanghai].

It was found that a variety of plagues were prevalent in Shanghai at the end of the Qing Dynasty and the beginning of the Republic of China, by analysing and synthesising the epidemic situation, the causes of the epidemic, the social impact, and prevention and control measures. These plagues led to serious social harm and economic losses. Their causes were believed closely related to some factors, such as urban environment, population flow, and climate changes. Their prevention appeared to be applicable and effective. The Shanghai concession and Chinese authorities organised society to fight against plagues and stabilise the social order. Charity organisations of the local communities were also involved in social support. It was found that more can be done in studies on interdisciplinary synthesis, comparative study of epidemic prevention measures of managers, and of traditional Chinese medicine prevention and treatment.

Influenza virus infection augments susceptibility to respiratory Yersinia pestis exposure and impacts the efficacy of antiplague antibiotic treatments.

Various respiratory viral infections in general and seasonal influenza in particular may increase the susceptibility to bacterial infections. Plague caused by Yersinia pestis endangers large populations during outbreaks or bioterrorism attacks. Recommended antibiotic countermeasures include well-established protocols based on animal studies and corroborated by effective treatment of human cases. Until now, prior exposure to viral respiratory infections was not taken into consideration when selecting the appropriate treatment for plague. Here, we show that as late as 25 days after exposure to influenza virus, convalescent mice still exhibited an increased susceptibility to sublethal doses of Y. pestis, presented with aberrant cytokine expression, and impaired neutrophil infiltration in the lungs. Increased levels of M2 alveolar macrophages and type II epithelial cells, as well as induction in metalloproteases expression and collagen and laminin degradation, suggested that the previous viral infection was under resolution, correlating with enhanced susceptibility to plague. Surprisingly, postexposure prophylaxis treatment with the recommended drugs revealed that ciprofloxacin was superior to doxycycline in mice recovering from influenza infection. These results suggest that after an influenza infection, the consequences, such as impaired immunity and lung tissue remodeling and damage, should be considered when treating subsequent Y. pestis exposure.

Techniques and Strategies for Potential Protein Target Discovery and Active Pharmaceutical Molecule Screening in a Pandemic.

Viruses remain a major challenge in the fierce fight against diseases. There have been many pandemics caused by various viruses throughout the world over the years. Recently, the global outbreak of COVID-19 has had a catastrophic impact on human health and the world economy. Antiviral drug treatment has become another essential means to overcome pandemics in addition to vaccine development. How to quickly find effective drugs that can control the development of a pandemic is a hot issue that still needs to be resolved in medical research today. To accelerate the development of drugs, it is necessary to target the key target proteins in the development of the pandemic, screen active molecules, and develop reliable methods for the identification and characterization of target proteins based on the active ingredients of drugs. This article discusses key target proteins and their biological mechanisms in the progression of COVID-19 and other major epidemics. We propose a model based on these foundations, which includes identifying potential core targets, screening potential active molecules of core targets, and verifying active molecules. This article summarizes the related innovative technologies and methods. We hope to provide a reference for the screening of drugs related to pandemics and the development of new drugs.

An open-label, randomized, non-inferiority trial of the efficacy and safety of ciprofloxacin versus streptomycin + ciprofloxacin in the treatment of bubonic plague (IMASOY): study protocol for a randomized control trial.

BACKGROUND: Bubonic plague is the primary manifestation of infection with Yersinia pestis, accounting for 90% of all plague cases and with 75% of global cases reported in Madagascar. All drugs in use for treating plague are registered based on experimental data and anecdotal evidence, and no regimen currently recommended is supported by a randomized clinical trial. The IMASOY trial intends to fill this knowledge gap by comparing two 10-day regimens included in the national guidelines in Madagascar. The primary objective of the trial is to test the hypothesis that ciprofloxacin monotherapy is non-inferior to streptomycin followed by ciprofloxacin for the treatment of bubonic plague, thus avoiding the need for injectable, potentially toxic, aminoglycosides. METHODS: A two-arm parallel-group randomized control trial will be conducted across peripheral health centres in Madagascar in five districts. Males and non-pregnant females of all ages with suspected bubonic or pneumonic plague will be recruited over the course of three plague 'seasons'. The primary endpoint of the trial is to assess the proportion of patients with bubonic plague who have a therapeutic response to treatment (defined as alive, resolution of fever, 25% reduction in the size of measurable buboes, has not received an alternative treatment and no clinical decision to continue antibiotics) as assessed on day 11. DISCUSSION: If successful, the trial has the potential to inform the standard of care guidelines not just in Madagascar but in other countries afflicted by plague. The trial is currently ongoing and expected to complete recruitment in 2022. TRIAL REGISTRATION: ClinicalTrials.gov NCT04110340 . Registered on 1 October 2019.

Immunotropic Properties of an Experimental Synthetic Selenium-Organic Compound.

We studied immunotropic properties of synthetic selenium-organic preparation 2,6-dipyridinium-9-selenabicyclo[3.3.1]nonyl dibromide (974zh). The experimental preparation reduced the cAMP/cGMP ratio, which indicated an increase in proliferative activity of cells of immunocompetent organs (thymus and spleen) in experimental animals. It was shown that 974zh intensified the immune response to Yersinia pestis EV thereby increasing the resistance to the plague agent.

Effect of Delaying Treatment on Efficacy of Ciprofloxacin and Levofloxacin in the African Green Monkey Model of Pneumonic Plague.

BACKGROUND: Ciprofloxacin and levofloxacin, 2 fluoroquinolone antimicrobials, are ≥90% effective for the treatment of inhalational plague when administered within 2-6 hours of fever onset in African green monkeys (AGM). Based on data in the AGM model, these antimicrobials were approved under the Food and Drug Administration's Animal Efficacy Rule. However, that data did not address the issue of how long treatment with these antimicrobials would remain effective after fever onset. METHODS: The AGM model of pneumonic plague was used to explore the effect of delaying treatment with ciprofloxacin and levofloxacin on efficacy. In 2 studies, AGMs were challenged with inhaled lethal doses of Yersinia pestis. Treatment with ciprofloxacin and levofloxacin was initiated from 0 to up to 30 hours after fever onset. RESULTS: Challenged animals all developed fever within 78 hours and were treated with ciprofloxacin (n = 27) or levofloxacin (n = 29) at various predetermined time points postfever. When administered 10 hours after fever onset, 10 days of ciprofloxacin and levofloxacin treatment remained very effective (90 or 100%, respectively). The efficacy of both antimicrobials declined as treatment initiation was further delayed. Statistical analyses estimated the treatment delay times at which half of the AGMs were no longer expected to survive as 19.7 hours for ciprofloxacin and 26.5 hours for levofloxacin. CONCLUSIONS: This study demonstrates that there is a narrow window following fever onset during which ciprofloxacin and levofloxacin are fully effective treatment options for pneumonic plague in AGMs. Since the timing of disease is similar in humans and AGMs, these AGM data are reasonably likely to predict response times for treatment in humans.

Plagues and artistic votive expressions (ex voto) of popular piety.

In past centuries, epidemics, the scourge of humankind, caused pain, anger, uncertainty of the future, social as well as economic disorder and a significant impact on their victims, involving also their spiritual sphere. The latter effect led to undoubted effects on participation in the religious and social life of communities. The custom of preparing artistic votive expressions has been lost in the mists of time and evidence of ex voto gifts, offered by believers to pagan gods, has been found in prehistoric archaeological sites. Furthermore, several finds from the Ancient Greek and Roman worlds may be observed in our museums. These remains are generally ceramic and metal artifacts, reproducing limbs and other body parts which had been healed. These elements, according to the belief of those making the offerings, had benefited from the miraculous intervention of a thaumaturgical deity. With the advent of Christianity, some pre-existing religious practices were endorsed by the new religion. Believers continued to demonstrate their gratitude in different ways either to miracle-working saints or to the Virgin Mary, because they thought that, thanks to an act of faith, their own health or that of a family member would benefit from the direct intervention of the divine entities to whom they had prayed. In the Ancient Greek world, it was believed that the god Asclepius could directly influence human events, as testified by the popularity of shrines and temples to the god, especially at Epidaurus. In the Christian world as well, particular places have been detected, often solitary and secluded in the countryside or in the mountains, where, according to tradition, direct contact was established between the faithful and Saints or the Virgin Mary Herself. Manifestations occurred by means of miracles and apparitions, thereby creating a direct link between the supernatural world and believers. Religious communities, in these extraordinary places, responded to the call through the building of shrines and promotion of the cult. Over time, the faithful reached these places of mystery, performing pilgrimages with the aim of strengthening their religious faith, but also with the purpose of seeking intercession and grace. In this case, the request for clemency assumed spiritual characteristics and also became a profession of faith. Accordingly, the shrines in the Christian world are places where supernatural events may occur. In these environments the believer resorted to faith, when medicine showed its limits in a tangible way. For the above reasons, while epidemics were occurring, the requests for clemency were numerous and such petitions were both individual and collective. In particular, by means of votive offerings (ex voto) the believers, both individually and collectively, gave the evidence of the received grace to the thaumaturgical Saint. Through the votive act, a perpetual link between the believer and the Saints or Holy Virgin was forged and a strong request for communion was transmitted. The aim of the present study is to describe the role played by votive tablets (ex voto) in the last 500-600 years, as visible evidence of human suffering. From this perspective, these votive expressions may assume the role of markers because, in accordance with the expressions of popular faith, they allow us to follow the most important outbreaks that have caused distress to Christian communities.