Piscirickettsia salmonis is a globally distributed aquatic bacterium and a component of the normal salmon microbiome. It has significant biological and economic impact on Chilean salmon aquaculture due to the highly fatal disease, piscirickettsiosis. Unsuccessful attempts to prevent and treat this disease have resulted in heavy use of antimicrobials with adverse effects on the aquatic environment and piscine and human health. Evidence suggests P. salmonis could be a bacterium with relative pathogenic potential on farmed salmonids and other fishes that triggers piscirickettsiosis under particular conditions in the salmon and its environment. Application of a damage-response framework analysis could define the steps from asymptomatic P. salmonis infection to symptomatic disease, help tailor improved approaches to disease prevention and management, and, in turn, help avoid heavy use of antimicrobials which have global effects on animal health, human health, and environmental biodiversity (the One Health concept).

Diego Rivera, an acclaimed Mexican painter active during the first half of the 20th century, painted multiple frescoes in Mexico and the United States. Some include depictions of bacteria, their interactions with human hosts, and processes related to microbiology and public health, including the microbial origin of life, diagnosis of infection, vaccine production, and immunization. Microbiological subjects in Rivera's murals at the Mexican Ministry of Health in Mexico City; the Detroit Institute of Art, Detroit; Rockefeller Center, New York/Palacio de Bellas Artes, Mexico City; Chapultepec Park, Mexico City; and the Institute of Social Security, Mexico City, span almost 25 years, from 1929 to 1953. Illustrating the successes of the application of microbiological discoveries and methods to public health and the prevention and treatment of infectious diseases, they benefited from Rivera's creativity in melding microbiology's unique technological and scientific aspects and public health elements with industrial and political components.

Recent information from Chile suggests the apparent high virulence of Piscirickettsia salmonis in cultured salmonids results from the stress generated by the unhealthily high concentrations at which the fish are grown during production rather than by any inherently greater virulence of this seemingly opportunistic pathogen. These high levels of disease lead to excessive use of antimicrobials that in turn negatively affect piscine and human health and the environment.

The exponential growth of aquaculture over the past 30 years has been accompanied by a parallel increase in the use of antimicrobials. This widespread use has had negative effects on animal, human and environmental health and affected the biodiversity of the environments where aquaculture takes place. Results showing these harmful effects have been resisted and made light of by the aquaculture industry and their scientific supporters through introduction of misunderstandings and misinterpretations of concepts developed in the evolution, genetics, and molecular epidemiology of antimicrobial resistance. We focus on a few of the most obvious scientific shortcomings and biases of two recent attempts to minimise the negative impacts of excessive antimicrobial use in Chilean salmon aquaculture on human and piscine health and on the environment. Such open debate is critical to timely implementation of effective regulation of antimicrobial usage in salmon aquaculture in Chile, if the negative local and worldwide impacts of this usage are to be avoided.

The annual incidence of Lyme disease, caused by tick-transmitted Borreliella burgdorferi, is estimated to be at least 476,000 cases in the United States and many more worldwide. Ten to 20% of antimicrobial-treated Lyme disease patients display posttreatment Lyme disease syndrome (PTLDS), a clinical complication whose etiology and pathogenesis remain uncertain. Autoimmunity, cross-reactivity, molecular mimicry, coinfections, and borrelial tolerance to antimicrobials/persistence have been hypothesized and studied as potential causes of PTLDS. Studies of borrelial tolerance/persistence in vitro in response to antimicrobials and experimental studies in mice and nonhuman primates, taken together with clinical reports, have revealed that B. burgdorferi becomes tolerant to antimicrobials and may sometimes persist in animals and humans after the currently recommended antimicrobial treatment. Moreover, B. burgdorferi is pleomorphic and can generate viable-but-nonculturable bacteria, states also involved in antimicrobial tolerance. The multiple regulatory pathways and structural genes involved in mediating this tolerance to antimicrobials and environmental stressors by persistence might include the stringent (rel and dksA) and host adaptation (rpoS) responses, sugar metabolism (glpD), and polypeptide transporters (opp). Application of this recently reported knowledge to clinical studies can be expected to clarify the potential role of bacterial antibacterial tolerance/persistence in Lyme disease and PTLDS.

Dr. Avendaño-Herrera's comments (Avendaño-Herrera, 2021) on our review (Godfrey and Cabello, 2019) are mostly marginal to its content. They provide insufficient scientific evidence to weaken our hypothesis that Piscirickettsia salmonis is a potential opportunistic (facultative) pathogen/endogenous pathobiont of salmon. They also fail to undermine our review's central points, that infections caused by P. salmonis could be prevented by improved husbandry practices and that the excessive amounts of antimicrobials used in Chilean salmon aquaculture for their prevention/treatment are detrimental to the health of fish, other animals, humans and the environment.

Large amounts of antimicrobials are used in salmonid aquaculture in Chile. Most are used in marine aquaculture, but appreciable amounts are also employed in freshwater aquaculture. Much research and many publications have examined transferable antimicrobial resistance in bacteria isolated from marine salmon farms, but much less attention has been paid to this area in freshwater salmon farming. A recent paper by Domínguez et al. (2019) has as least in part remedied this situation. We now comment on some of its interpretations and have attempted to point out its areas of strength and weakness in light of the published scientific literature. Seen in this setting, the important results presented by Domínguez et al. (2019) underline the need for increased awareness of the challenge to animal and human health posed by excessive use of antimicrobials in aquaculture.

Aquaculture now produces nearly half of the seafood consumed globally. Atlantic salmon (Salmo salar) is one of the top aquaculture products and the most valuable farmed marine finfish species in the United States (U.S.). The aim of this study is to better understand veterinary drug use in U.S. net pen Atlantic salmon aquaculture and compare these findings to other salmon producing countries and U.S. livestock. We collected and analyzed records on Atlantic salmon production and veterinary drug use in Maine (2003 to 2017) and Washington (2012 to 2017). Antimicrobial medicated feeds were used in 8% and 93% of production cycles in Maine and Washington, respectively. Oxytetratcycline was the primary drug used in both states. Maine used no antimicrobials in eight of the past 15 yrs., including none in 2017. Emamectin benzoate, an antiparasitic medicated feed, was used in 28% production cycles in Maine (2014 to 2017; avg. 1.1 kg/yr) and no emamectin benzoate was administered in Washington over the time period studied. From 2014 to 2016, the U.S. farmed salmon industry contributed 0.8% +/- 0.1% to annual global farmed salmon production and administered 1.2% +/- 0.6% of antimicrobials used in global salmon farming. Over the same time period, Norway and Chile accounted for 53% +/- 3% and 35% +/- 3% of annual global production, and administered 0.06% +/- 0.02% and 96% +/- 0.09% of antimicrobials used in global salmon farming. Compared to U.S. terrestrial agriculture in 2016, the U.S. Atlantic salmon industry contributed 0.031% to U.S. food animal production and administered 0.057% of antimicrobials available to U.S. food animals. Based on the data we collected, the U.S. Atlantic salmon aquaculture industry is a relatively small user of antimicrobials compared to U.S. beef, pigs, poultry, and Chilean salmon industries. There are relatively few approved drugs in the U.S. to treat aquaculture diseases and more options are needed as well as continued work on vaccines. Antimicrobial resistance is a worldwide public health concern; the overuse or misuse of antimicrobials in any setting can compromise the treatment of bacterial infections. The U.S. net pen Atlantic salmon aquaculture industry appears to be the first U.S. food animal industry to report monthly antimicrobial use at the farm-level to the government. These data are critical to assess public health risks associated with antimicrobial use and resistance, and therefore, are needed from all U.S. food animal industries.

The study of mortality and the calculation of excess deaths is a fundamental tool for understanding the effect of epidemics / pandemics and the seasonal cycles of endemic / epidemic diseases such as influenza, which is of great importance in times of crisis, according to the WHO and different authors. In this study, we analyzed the indicator of excess deaths in Chile during the COVID-19 pandemic. Simultaneously, research is being carried out to corroborate and characterize possible causes of the underestimation of deaths by official health agencies.

Una carta. Entiendo que no necesita resumen

In two recently published articles in Aquaculture, Mardones et al. (2018) discuss the emergent fish pathogen and cause of salmonid rickettsial syndrome (SRS), Piscirickettsia salmonis, while Avendaño-Herrera (2018) discusses the heavy use of antimicrobials in Chile to prevent and treat salmonid bacterial infections including SRS. Mardones et al. put forward a research agenda that focuses largely on P. salmonis and its relation to the biology of SRS. We believe a broader view of the problem would be beneficial. An extended examination of the scientific literature suggests that P. salmonis is likely an opportunistic environmental pathogen with low levels of virulence and pathogenicity and/or an endogenous pathobiont colonizing the normal salmonid microbiome. Multiplication of this bacterium and its ability to produce SRS is at least in part triggered by shortcomings in piscine husbandry that negatively affect salmonid health and well-being. This explanation is consistent with the limited efficacy of vaccines and antimicrobials in preventing and modifying the course of SRS, and suggests that efforts focused on geographical concentration of aquaculture sites; high densities of cultured fish at these sites; levels of nutrients and eutrophication; co-infections with bacteria, viruses and sea lice; excessive use of antimicrobials and other treatments for these infections; and climate change would deserve increased research consideration in the future. In their analyses and proposed research agendas, neither of these articles takes into account the negative effects of excessive and perhaps unnecessary antimicrobial use on piscine, human and environmental health as understood by the One Health paradigm.

Although public health and social medicine have a long history in Latin America going back to Colonial times, their relevance has ebbed and flowed as a result of the development of a variety of social and political movements. The Mexican Revolution accelerated implementation of public health policies in Mexico and resulted in the creation of the Mexican Institute of Social Security to serve the health and social security needs of the country's population. Construction of the Hospital La Raza and its embellishment by the mural paintings of Diego Rivera and David Alfaro Siqueiros corresponded to the heyday of public health ideas in Mexico. This is clearly reflected in Rivera's mural painting from 1953, The History of Medicine in Mexico: People's Demand for Better Health. The left side of the painting, representing the history of modern medicine in Mexico, exemplifies the tensions between individuals and social groups demanding the fruits of modern medicine and public health, and entrenched bureaucracy and private interests resisting their demands. Rivera's artistry illustrates this tension by depicting urban social groups and a family with a pregnant mother and children requesting medical attention on one side of the main panel, facing condescending physicians, bureaucrats and upper society gentlemen and ladies on the other side. The importance of social movements to the development of public health policies illustrated by Rivera in 1953 continues to be relevant in Latin America today where increasing millions still lack the benefits of health care and social security.

The author in this short text remembers the passing of a beloved pet cat. Cats are beautiful animals and wonderful companions. They evolved together with humans in Africa, subsequently spread over the five continents with them, and became the subject of many human cultural activities, including art, poetry and religion. Abandoned and roaming free, cats readily return to the wild, potentially acquiring many zoonotic infections. Surprisingly, feline company is increasingly used for therapy of mental and other illnesses such as cardiovascular disorders. Responsible ownership and good veterinary care of these marvelous animals under the One Health paradigm are essential to their well-being as well as to that of humans. They are an ethical and small price to pay for the affectively rewarding relationships humans have with these endearing and evocative animals.

Julio Escámez Contreras was a highly creative, skilled and versatile Chilean painter who painted in Chile from 1940 to 1974 when he went into exile to Costa Rica and died there in 2015. In 1953-54, Escámez painted a large mural in a private pharmacy in the city of Concepcion, Chile, The History of Medicine and Pharmacy in Chile. This mural describes the origins and development of medicine and pharmacy in Chile, placing that origin in the medicinal activities of the mapuche indigenous population. The mural consists of three sections, each painted on the upper segment of three adjacent walls in the pharmacy, with each section focused on one period in the evolution of medicine and pharmacy in Chile. The first section is devoted to indigenous medical practices including its pharmacopeia and religious practices, the second describes medical approaches during colonial times, still with strong indigenous components but also with indigenous and Catholic hybrid religious elements, while the third depicts modern medicine, including chemistry, anatomical, physical and pharmacological activities complemented with public health components such as nursing, vaccination and health education. Read from left to right, the mural provides a highly lively, accurate and valid depiction of the evolution of medicine and pharmacy in Chile. Escámez' artistry and skill in the use of perspective, color, landscape, architecture and Chilean subjects, including real life individuals, produces a typical Chilean mural. However, his originality and consummate use of a non-verbal visual language delivers a more universal message, one that helps to explain the repeated efforts, of the government responsible for his exile, to destroy some of the works produced by him.

Ed. Note: The authors of the published article did not feel that a response was necessary. The interesting work by Shen et al. ([1][1]) discusses the pathogenicity of Aeromonas for freshwater fish in passing but does not mention that Aeromonas are not only pathogenic for freshwater fish but also

Northern Europe at the beginning of the 16th Century was in turmoil as a result of religious and political dissention, epidemics of plague, syphilis, ergotism, and famine, and the threat of the Ottoman Empire. In Alsace, a fulcrum between Germany, France, Switzerland and the Netherlands, Grunewald painted his celebrated and complex altarpiece at Isenheim in a convent chapel of the Antonine religious order that kept a hospital for the care of patients suffering from ergotism, plague, syphilis and other illnesses. The ten paintings of this altarpiece convey a series of religious, medical and political meanings, with the scenes of the Crucifixion and the Resurrection being thought to play an integral part of the curative process. This was because patients could be soothed by comparing their suffering to that of Christ on the cross and could console themselves by the Resurrection. The portrait of Christ in the cross is astounding in its realism and naturalism. It represents, with great pathological veracity, a tortured body in agony, a break with previous traditional representations of this event. Impressive pathological detail is also given to a figure in the Temptation scene. The entire work is suffused with religious connotations provided by the composition, the forms and the richness and sophisticated use of colors. Although Grunewald's paintings are few and the facts of his personal life sparse, it is known he married a Jewish woman, supported the peasant revolts, and was probably a Lutheran in a Catholic area. While Grunewald is considered the epitome of a German artist, the universal projections of his art have influenced physicians and the artistic productions of many painters, writers, musicians and sculptors throughout the world.

The emergence and dissemination of antimicrobial-resistant bacteria (ARB) is currently seen as one of the major threats to human and animal public health. Veterinary use of antimicrobials in both developing and developed countries is many-fold greater than their use in human medicine and is an important determinant in selection of ARB. In light of the recently outlined National Plan Against Antimicrobial Resistance in Chile, our findings on antimicrobial use in salmon aquaculture and their impact on the environment and human health are highly relevant. Ninety-five percent of tetracyclines, phenicols and quinolones imported into Chile between 1998 and 2015 were for veterinary use, mostly in salmon aquaculture. Excessive use of antimicrobials at aquaculture sites was associated with antimicrobial residues in marine sediments 8 km distant and the presence of resistant marine bacteria harboring easily transmissible resistance genes, in mobile genetic elements, to these same antimicrobials. Moreover, quinolone and integron resistance genes in human pathogens isolated from patients in coastal regions adjacent to aquaculture sites were identical to genes isolated from regional marine bacteria, consistent with genetic communication between bacteria in these different environments. Passage of antimicrobials into the marine environment can potentially diminish environmental diversity, contaminate wild fish for human consumption, and facilitate the appearance of harmful algal blooms and resistant zoonotic and human pathogens. Our findings suggest that changes in aquaculture in Chile that prevent fish infections and decrease antimicrobial usage will prove a determining factor in preventing human and animal infections with multiply-resistant ARB in accord with the modern paradigm of One Health.

Northern Europe at the beginning of the 16th Century was in turmoil as a result of religious and political dissention, epidemics of plague, syphilis, ergotism, and famine, and the threat of the Ottoman Empire. In Alsace, a fulcrum between Germany, France, Switzerland and the Netherlands, Grünewald painted his celebrated and complex altarpiece at Isenheim in a convent chapel of the Antonine religious order that kept a hospital for the care of patients suffering from ergotism, plague, syphilis and other illnesses. The ten paintings of this altarpiece convey a series of religious, medical and political meanings, with the scenes of the Crucifixion and the Resurrection being thought to play an integral part of the curative process. This was because patients could be soothed by comparing their suffering to that of Christ on the cross and could console themselves by the Resurrection. The portrait of Christ in the cross is astounding in its realism and naturalism. It represents, with great pathological veracity, a tortured body in agony, a break with previous traditional representations of this event. Impressive pathological detail is also given to a figure in the Temptation scene. The entire work is suffused with religious connotations provided by the composition, the forms and the richness and sophisticated use of colors. Although Grünewald's paintings are few and the facts of his personal life sparse, it is known he married a Jewish woman, supported the peasant revolts, and was probably a Lutheran in a Catholic area. While Grünewald is considered the epitome of a German artist, the universal projections of his art have influenced physicians and the artistic productions of many painters, writers, musicians and sculptors throughout the world.