Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “zoonotic potential”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 433 records · Page 24Linked to original sources

From buffalo to human: Klebsiella pneumoniae in high-somatic cell count milk as an overlooked link in the one health chain.

High somatic cell count (SCC) is a critical indicator of udder health and milk quality in buffalo milk production. However, in many low-income regions, SCC monitoring is often underemphasized, allowing a proportion of high-SCC buffalo milk to enter the food chain and potentially compromising food safety and public health. Klebsiella pneumoniae (K. pneumoniae) is a common zoonotic pathogen found in high-SCC milk, yet systematic investigations into the prevalence and characteristics in high-SCC buffalo milk remain limited. In this study, 23 K. pneumoniae strains were screened out from 460 bacterial isolates obtained from high-SCC buffalo milk samples from Guangxi, China, with an isolation rate of 5.0%. These isolates were comprehensively characterized using whole-genome sequencing and comparative genomic analyses. The results revealed that 78.26% (18/23) of the isolates shared high genomic similarity with the human reference strain ATCC 13883, and the ST37 clone exhibited a pronounced potential of cross-species transmission. All isolates harbored core adhesion factors and intrinsic resistance genes. Notably, several strains displayed high-risk features: strain 419 carried the K1 capsular serotype, strain 326 possessed a complete yersiniabactin synthesis gene cluster, and strain 320 exhibited a multidrug-resistant phenotype. Phenotypic assays further demonstrated a positive correlation between biofilm formation capacity and virulence in Galleria mellonella. Metabolic pathway enrichment analyses suggested that K. pneumoniae has undergone substantial adaptation to the nutrient-rich buffalo milk environment. Collectively, these findings confirm that raw high-SCC buffalo milk serves as a significant reservoir for high-risk zoonotic K. pneumoniae. While industrial thermal processing effectively eliminates viable pathogens, the resilient antimicrobial resistance determinants within these isolates pose a persistent risk of horizontal gene dissemination along the food chain, providing critical evidence for enhancing pre-processing milk quality regulations within a One Health framework.

Animals↗

Who let the dogs out? Infection control did: utility of dogs in health care settings and infection control aspects.

Research has substantiated that animals improve human health, both psychologically and physiologically. Therefore, healthcare facilities have begun to implement programs, such as the "Furry Friends Foundation," that bring animals into the facility to improve the quality of life of patients. When implementing these programs, consideration must be given to potential adverse events such as phobias, allergies, and particularly the possibility of zoonotic disease transmission. Santa Clara Valley Medical Centre (SCVMC), a 600-bed county teaching hospital with specialized units (e.g., for burns, rehabilitation, and pediatric care), has implemented programs that incorporate animals into the healthcare setting. This facility allows three categories of dogs to interact with their patients: service dogs, therapy dogs, and pet visitation dogs by the "Furry Friends Foundation." A blurring of the roles of the three categories of dogs occurred when these programs were put into place at SCVMC. The American with Disabilities Act (ADA) states that service animals cannot be prohibited from any area. For example, a "no pet allowed" policy could not apply to these animals. Proof of a person's disability or proof of the service animal's health or training cannot be required. The purpose of this project was to maintain these programs by clarifying the policies regarding animals, specifically dogs, in the healthcare setting. This had to take place to provide a safe and enjoyable environment for the patients and the staff. A comprehensive table was developed to delineate the three categories of dogs and the corresponding policies. Therapy dogs and the visitation animals are more restricted than service dogs. Both therapy dogs and visitation dogs require identification and certification of health and are excluded from certain areas of the facility, including intensive care units and isolation rooms. By complying with the current policies and regulations, the risks from these programs can be minimized. Staff should be educated on the proper terminology and procedures to prevent a blurring of the categories and roles of these animals.

Animals↗

Clinical perspectives of emerging pathogens in bleeding disorders.

As a result of immunological and nucleic-acid screening of plasma donations for transfusion-transmissible viruses, and the incorporation of viral reduction processes during plasma fractionation, coagulation-factor concentrates (CFC) are now judged safe in terms of many known infectious agents, including hepatitis B and C viruses, HIV, and human T-cell lymphotropic virus. However, emerging pathogens could pose future threats, particularly those with blood-borne stages that are resistant to viral-inactivation steps in the manufacturing process, such as non-lipid-coated viruses. As outlined in this Review, better understanding of infectious diseases allows challenges from newly described agents of potential concern in the future to be anticipated, but the processes of zoonotic transmission and genetic selection or modification ensure that plasma-derived products will continue to be subject to infectious concerns. Manufacturers of plasma-derived CFC have addressed the issue of emerging infectious agents by developing recombinant products that limit the need for human plasma during production. Such recombinant products have extended the safety profile of their predecessors by ensuring that all reagents used for cell culture, purification steps, and stabilisation and storage buffers are completely independent of human plasma.

Animals↗

Pet ownership and childhood acute leukemia (USA and Canada).

OBJECTIVES: For more than three decades there has been speculation regarding a possible role of zoonotic diseases in the development of human leukemia. This study investigated the potential relationship between exposure to pets and the development of childhood leukemia. METHODS: Data from 2359 cases of acute leukemia from two large case-control studies were analyzed. Cases were individually matched to population controls on telephone exchange, age, and race. Conditional logistic regression was used to estimate odds ratios (OR) associated with pet ownership. RESULTS: Overall, there was no association between pet ownership (either "any pet", dog, or cat) and childhood acute leukemia (OR(any pet:) = 1.01, 95% CI 0.89-1.2). Additionally, no relationship was found between exposure to an ill pet and childhood leukemia. CONCLUSION: The results of this analysis suggest that pet ownership (healthy or sick) is unrelated to an increased risk of childhood leukemia.

Adolescent↗

The molecular epidemiology of Giardia lamblia: a sequence-based approach.

Animals are commonly considered to be potential sources for Giardia lamblia infections in humans, but the extent of zoonotic transmission of G. lamblia remains controversial because of inadequate understanding of its epidemiology. A better understanding of the epidemiology of G. lamblia may be facilitated by a more effective means for classifying G. lamblia isolates. To develop a sequence-based classification system, the gene encoding the metabolic enzyme triose phosphate isomerase (tim) was sequenced from a number of G. lamblia isolates of various host origins. Restriction enzymes were identified that can distinguish among isolates without the need for sequencing, simplifying the application of this approach to the epidemiologic investigation of giardiasis. Isolates from a previously reported epidemic of giardiasis were accurately classified by this technique, further verifying its utility for epidemiologic investigation.

Animals↗

Limiting potential infectious risks of transplanting insulin-producing pig cells into humans.

AIMS: Prior to commencing a study of grafting foetal/neonatal pig islet-like cell clusters into type I diabetic human subjects, the microbiological risks of transplanting porcine pancreatic tissue were assessed. METHODS: An exclusion list for screening donor animals and graft tissue in Australia was compiled following evaluation of the disease risks posed by 121 organisms, including 36 bacteria, 12 fungi, four mycoplasma, 31 parasites and 38 viruses. The list of evaluated agents was derived from the literature, interviews with veterinarians and physicians, and a survey of laboratories. RESULTS: The exclusion list contains 35 organisms (including 20 bacteria, four fungi, one mycoplasma, one parasite and nine viruses) that are zoonotic, pathogens of immunocompromised hosts (including human allograft recipients), pathogens resistant to antibiotics or potentially able to recombine with the human genome. These 35 agents can be detected by culture (e.g., Actinomyces), serological testing (e.g., influenza viruses) or nucleic acid amplification (e.g., Mycobacteria). CONCLUSIONS: It is recommended that: (i) source pigs designated for use in human xenotransplantation trials should be tested regularly for the 35 organisms; (ii) the mothers of donor foetal/neonatal pigs and, when possible, the foetal/ neonatal pigs themselves should be tested immediately prior to the grafting of tissue into humans; and (iii) the exclusion list be modified for designated source pig herds in countries other than Australia.

Animals↗

Land-based birds as potential disseminators of avian mammalian reassortant influenza A viruses.

Chickens, quail, and other land-based birds are extensively farmed around the world. They have been recently implicated in zoonotic outbreaks of avian influenza in Hong Kong. The possibility that land-based birds could act as mixing vessels or disseminators of avian/mammalian reassortant influenza A viruses with pandemic potential has not been evaluated. In this report, we investigated whether chickens and Japanese quail are susceptible to a mammalian influenza virus (A/swine/Texas/4199-2/98 [H3N2]). This virus did not grow in chickens and replicated to low levels in Japanese quail but did not transmit. Replacing the H3 gene of this virus for one of the avian H9 viruses resulted in transmission of the avian/swine reassortant virus among quail but not among chickens. Our findings demonstrated that Japanese quail could provide an environment in which viruses like the A/swine/Texas/4199-2/98 [H3N2] virus could further reassort and generate influenza viruses with pandemic potential.

Animals↗

Zoonotic poxvirus infections in humans.

PURPOSE OF REVIEW: The 2003 USA monkeypox epidemic caused by imported African rodents, newly emergent poxvirus zoonoses in Brazil and the possible use of variola virus for biological warfare has led to renewed interest in poxviruses and anti-poxviral therapies. Increasing foreign travel and importation of exotic animal species increases the likelihood of poxvirus infections occurring outside their usual geographical range and diagnostic delay has important implications. The present review provides an overview of these rare zoonoses. RECENT FINDINGS: Three genera of Poxviridae are known to cause human zoonoses: orthopoxviruses, parapoxviruses and yatapoxvirus. Most cases are occupational, sporadic and have few cutaneous lesions with low morbidity. The exception is monkeypox, similar to smallpox, with significant morbidity and childhood mortality. Molecular characterization using polymerase chain reaction (PCR) amplification and other methods provides accurate phylogenetic identification and suggests that a cowpox-like virus is the probable ancestor of variola and other zoonotic poxviruses. DNA genomic sequencing of the Brazilian Cantagalo and Araçatuba viruses shows a close relationship to vaccinia virus. Poxviruses have potential in cancer immunotherapy and their ability to evade host-cell immune responses may provide a basis for new antipoxvirus therapies. Other agents, particularly nucleoside phosphonates such as cidofovir, show therapeutic action against poxviruses. SUMMARY: Human zoonotic poxvirus infections are rare but increasingly encountered outside their usual geographical range. The 2003 USA monkeypox outbreak emphasizes the importance of early accurate diagnosis, particularly because increasing numbers of immunosuppressed individuals increases the potential for severe or fatal infections. PCR methodology enables accurate phylogenetic typing and has identified new diseases, but rapid, reliable methods must be made available for clinicians. More research into therapeutic agents for the prevention and treatment of poxvirus infections is required.

Animals↗

Viral zoonoses - a threat under control?

Despite intensive research and considerable effort to eradicate infectious diseases, modern medicine has failed to control many infectious diseases which have been thought to be easy to overcome with advances in medical science and technology. In fact, infectious diseases remain a dominant feature in public health considerations for the 21st century. Some infectious agents already known to be pathogenic have gained increasing importance in recent decades due to changes in disease patterns. Furthermore, many new, previously unknown infectious agents with a high pathogenic potential have been identified. Nearly all of these emergent disease episodes have involved zoonotic or species-jumping infectious agents. The complex interaction of factors like environmental and ecological changes, social factors, decline of health care, human demographics and behaviour influences the emergence of re-emergence of such diseases. Viruses, especially RNA viruses with their ability to adapt quickly to changing environmental conditions, are among the most prominent examples of emerging pathogens. In this review, we present the important examples of zoonotic viruses and discuss the factors playing a key role in the emergence and resurgence of these diseases.

Animal Husbandry↗

Mycobacterium tuberculosis in zoo and wildlife species.

Tuberculosis caused by Mycobacterium tuberculosis and M. tuberculosis-like organisms has been identified in a wide range of species, including non-human primates, elephants and other exotic ungulates, carnivores, marine mammals and psittacine birds. Disease associated with M. tuberculosis has occurred mostly within captive settings and does not appear to occur naturally in free-living mammals. Mycobacterium tuberculosis probably originated as an infection of humans, but from the zoonotic standpoint, non-human primates, Asian elephants and psittacine birds have the potential to transmit this disease to humans. However, the overall prevalence of disease in these susceptible species is low and documented transmissions of M. tuberculosis between animals and humans are uncommon. Mycobacterium tuberculosis causes progressive pulmonary disease in mammals and a muco-cutaneous disease in parrots. In all cases, the disease can disseminate and be shed into the environment. Diagnosis in living animals is based on intradermal tuberculin testing in non-human primates, culturing trunk secretions in elephants, and biopsy and culture of external lesions in parrots. Ancillary testing with deoxyribonucleic acid probes and nucleic acid amplification, and enzyme-linked immunosorbent assays have been adapted to some of these species with promising results. Additionally, new guidelines for controlling tuberculosis in elephants in the United States of America, and programmes for tuberculosis prevention in animal handlers have been established.

Animals↗

Sympatric Ixodes trianguliceps and Ixodes ricinus ticks feeding on field voles (Microtus agrestis): potential for increased risk of Anaplasma phagocytophilum in the United Kingdom?

The importance of wild rodents as reservoirs of zoonotic tick-borne pathogens is considered low in the United Kingdom because, in studies to date, those parasitized by exophilic Ixodes ricinus ticks carry almost exclusively larvae and thus have a minor role in transmission cycles. In a cross-sectional study, 11 (6.7%) of 163 field voles (Microtus agrestis) captured at field sites in Northern England were PCR-positive for Anaplasma phagocytophilum. The voles were found to act as hosts for both larval and nymphal I. ricinus and all stages of the nidicolous tick I. trianguliceps, and eight individuals were infested with ticks of both species at the same time. Two of 158 larval and one of 13 nymphal I. ricinus, as well as one of 14 larval and one of 15 nymphal I. trianguliceps collected from the rodents were PCR-positive. These findings suggest that habitats where field voles are abundant in the United Kingdom may pose a risk of A. phagocytophilum infection because (i) field voles, the most abundant terrestrial mammal in the United Kingdom, may be a competent reservoir; (ii) the field voles are hosts for both nymphal and larval ixodid ticks so they could support endemic cycles of A. phagocytophilum; and (iii) they are hosts for nidicolous I. trianguliceps, which may alone maintain endemic cycles, and exophilic I. ricinus ticks, which could act as a bridge vector and transmit infections to humans and domesticated animals.

Anaplasma phagocytophilum↗

Molecular phylogenies of Blastocystis isolates from different hosts: implications for genetic diversity, identification of species, and zoonosis.

Small-subunit (SSU) rRNA gene sequences were obtained by PCR from 12 Blastocystis isolates from humans, rats, and reptiles for which elongation factor 1alpha (EF-1alpha) gene sequences are already available. These new sequences were analyzed by the Bayesian method in a broad phylogeny including, for the first time, all Blastocystis sequences available in the databases. Phylogenetic trees identified seven well-resolved groups plus several discrete lineages that could represent newly defined clades. Comparative analysis of SSU rRNA- and EF-1alpha-based trees obtained by maximum-likelihood methods from a restricted sampling (13 isolates) revealed overall agreement between the two phylogenies. In spite of their morphological similarity, sequence divergence among Blastocystis isolates reflected considerable genetic diversity that could be correlated with the existence of potentially >/=12 different species within the genus. Based on this analysis and previous PCR-based genotype classification data, six of these major groups might consist of Blastocystis isolates from both humans and other animal hosts, confirming the low host specificity of Blastocystis. Our results also strongly suggest the existence of numerous zoonotic isolates with frequent animal-to-human and human-to-animal transmissions and of a large potential reservoir in animals for infections in humans.

Animals↗

Serologic survey of selected zoonotic disease agents in black-tailed jack rabbits from western Texas.

A serologic survey for the agents of Rocky Mountain spotted fever (RMSF) (Rickettsia rickettsii), Borrelia spp. including the causative agent for Lyme disease (Borrelia burgdorferi), and plague (Yersinia pestis) was conducted on blood samples collected from 30 and 46 black-tailed jack rabbits (Lepus californicus) from an urban environment in Lubbock, Texas (USA) during winter 1987 and the following spring 1988, respectively. Antibody titers to the agents of RMSF and borreliosis were detected in sera of 28 and 1% of the jack rabbits, respectively. Neither organisms (rickettsiae and/or spirochetes) nor their associated antigens were detected in any of the tissue or whole blood samples; plague antibodies were not detected in the 76 jack rabbits sampled. Four of 18 ticks (Dermacentor parumapertus) removed from 12 jack rabbits were positive for RMSF using the fluorescent antibody test. The black-tailed jack rabbit is a common wildlife species living in close proximity to higher density human populations in many areas of the southwestern United States. Our results indicate the potential importance of urban populations of this mammal as reservoirs for at least one important zoonotic disease, RMSF, in western Texas.

Animals↗

A procedure for high-yield spore production by Bacillus subtilis.

Bacillus subtilis spores have a number of potential applications, which include their use as probiotics and competitive exclusion agents to control zoonotic pathogens in animal production. The effect of cultivation conditions on Bacillus subtilis growth and sporulation was investigated in batch bioreactions performed at a 2-L scale. Studies of the cultivation conditions (pH, dissolved oxygen concentration, and media composition) led to an increase of the maximum concentration of vegetative cell from 2.6 x 10(9) to 2.2 x 10(10) cells mL(-)(1) and the spore concentration from 4.2 x 10(8) to 5.6 x 10(9) spores mL(-)(1). A fed-batch bioprocess was developed with the addition of a nutrient feeding solution using an exponential feeding profile obtained from the mass balance equations. Using the developed feeding profile, starting at the middle of the exponential growth phase and finishing in the late exponential phase, an increase of the maximum vegetative cell concentration and spore concentration up to 3.6 x 10(10) cells mL(-)(1) and 7.4 x 10(9) spores mL(-)(1), respectively, was obtained. Using the developed fed-batch bioreaction a 14-fold increase in the concentration of the vegetative cells was achieved. Moreover, the efficiency of sporulation under fed-batch bioreaction was 21%, which permitted a 19-fold increase in the final spore concentration, to a final value of 7.4 x 10(9) spores mL(-)(1). This represents a 3-fold increase relative to the highest reported value for Bacillus subtilis spore production.

Bacillus subtilis↗

The emerging technologies of neural xenografting and stem cell transplantation for treating neurodegenerative disorders.

Neural transplantation has normally been considered in the context of the neurodegenerative disorders, Parkinson's and Huntington's disease, which are characterized pathologically by the predominant loss of specific cells in the basal ganglia. This approach has now emerged from the experimental arena into the level of clinical trial, at least with respect to fetal human allografts. However the ethical and practical problems with using such tissue has led to the search for alternative sources of cells of which two of the most promising are cells from another species, such as the pig (xenografts), and stem cells. Neural transplantation using cells derived from the developing pig brain offers many advantages. Firstly, time-mated litters will overcome the issue of donor tissue supply. Secondly, advances in genetic technology have led to the development of pigs which have a reduced rejection potential. Thirdly, xenografted neural fiber outgrowth may be superior to that from neural grafts derived from the same species (allografts) which may increase the potential for circuit reconstruction. Disadvantages with this tissue source include concerns about transmission of zoonotic infections and the immunological rejection of the xenograft. Stem cells are defined as cells capable of division (self-renewal) and differentiation into a range of different cell types (differentiation). A variety of such cells exist including embryonic stem cells, neural stem cells derived from the developing fetal brain (neural progenitor cells), adult neural stem cells and adult stem cells originating from outside of the central nervous system. Each of these different types of stem cell have their own unique benefits but also disadvantages, and access to each type is constrained by a number of limiting factors. All of this means that the translation of these cell therapies into practice is not straightforward and must be done at a pace dictated by laboratory-based research rather than corporate share price.

Animals↗

Risk of infection with Cryptosporidium parvum and Cryptosporidium hominis in dairy cattle in the New York City watershed.

OBJECTIVE: To determine the risk posed by Cryptosporidium parvum and Cryptosporidium hominis from dairy cattle in the New York City watershed (NYCW). SAMPLE POPULATION: Samples from cattle at risk for shedding Cryptosporidium organisms on randomly selected dairy farms in the NYCW. PROCEDURE: Feces were collected for 4 years from calves at risk for infection on 37 dairies. Oocysts were detected by use of centrifugation concentration-flotation microscopy. The DNA was directly isolated from fecal samples and used to amplify fragments of the small subunit ribosomal RNA and thrombospondin-related adhesion protein C-2 genes by use of nested polymerase chain reaction assays. Small subunit ribosomal RNA fragments were restriction digested by the enzyme Vspl and thrombospondin-related adhesion protein C-2 fragments were digested by Eco91l to distinguish between C hominis (formerly known as genotype 1) and C parvum (formerly known as genotype 2). RESULTS: Of 437 fecal samples examined, 214 contained oocysts. Amplicons were generated for 200 samples. We can be certain, with 95% confidence, that cattle in the NYCW did not harbor C hominis. CONCLUSIONS AND CLINICAL RELEVANCE: Cryptosporidium infections in cattle are under examination because of the potential contamination of public waters by manure. Although cattle may be the source of zoonotic infection via C parvum, they pose little risk for C hominis (the strain commonly isolated from humans in waterborne outbreaks of disease). Other sources of oocysts should be considered when investigating outbreaks attributable to contaminated urban drinking water because cattle pose only a small risk via shedding of C hominis.

Animals↗

Importance in France of the infestation by Dirofilaria (Nochtiella) repens in dogs.

The presence of Dirofilaria repens has been mentioned in Europe, in Africa and in Asia, in different carnivores (dogs, foxes, cats, lions). In Europe the nematode has been reported in dogs, cats and foxes and the countries concerned by native cases are Italy, Spain, Greece, Yugoslavia and France. In France, until now, D. repens has been described, among animals, only in dogs. The first undoubted report dates back to 1953. Later, the prevalence was studied through widespread surveys (1986-1988-1989), focal surveys within some canine populations (military dogs) and some sporadic and fortuitous descriptions. The prevalence has been mainly assessed by pointing up the microfilariae in the blood and by identifying it after histochemical staining (for demonstration of the somatic distribution of acid phosphatase activity). The infestation rate was higher than 20% in some military dog populations. The cases occurred in nineteen French departments (Alpes-de-Haute-Provence, Aude, Bouches-du-Rhône, Corrèze, Corse, Dordogne, Gard, Gers, Gironde, Haute-Garonne, Loir-et-Cher, Nièvre, Pyrénées-Orientales, Rhône, Tarnet-Garonne, Var, Vaucluse, Vienne and Region Parisienne). The pathogenicity which is normally denied has to be reconsidered. The pathology of adult worms has not been clearly proved in dogs but the embolized microfilariae can bring about skin troubles. The potential pathogenicity, the necessity of the differentiation with D. immitis and above all, the zoonotic importance of D. repens must lead to search for it more often and to consider it with great interest.

Animals↗

Zoonotic aspects of filarial infections in man.

This article gives an account of the filarial parasites found in man and their potential transmissibility to and from other vertebrate animals under natural and experimental conditions.Those species that are regarded as being primarily parasites of other vertebrates, but which also infect man, are then dealt with in greater detail. These include the subperiodic strain of Brugia malayi and perhaps also B. pahangi, both of which are found in wild and domestic carnivores and monkeys, and Dirofilaria species of dogs and racoons.The Brugia parasites develop to maturity with the production of microfilaraemia and clinical manifestations in man similar to those caused by periodic B. malayi in man. Human dirofilariasis, on the other hand, represents a transmission cul-de-sac for the parasite. Clinical manifestations are mild or absent and generally the worms do not mature and, even if they do, they rarely give rise to microfilaraemia. D. immitis causes pulmonary dirofilariasis, and D. repens and D. tenuis give rise to subcutaneous nodules in man. The diagnosis of dirofilariasis depends on an awareness of the infection in the animal reservoirs and of the possibility of man being exposed to bites of infected vectors.

Animals↗