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PubMed1999

Ixodes scapularis: effects of repeated infestations with pathogen-free nymphs on macrophage and T lymphocyte cytokine responses of BALB/c and C3H/HeN mice.

Schoeler, G. B., Manweiler, S. A., and Wikel, S. K. 1999. Ixodes scapularis: Effects of repeated infestations with pathogen-free nymphs on macrophage and T lymphocyte cytokine responses of BALB/c and C3H/HeN mice. Experimental Parasitology 92, 239-248. Ixodes scapularis is the principal vector in the United States of Borrelia burgdorferi, the causative agent of Lyme borreliosis, the human granulocytic ehrichiosis agent, and Babesia microti. Infestation with I. scapularis nymphs has previously been shown to modulate host T lymphocyte cytokine production. Tick-induced host immunomodulation is increasingly recognized as a contributing factor in successful transmission and/or establishment of tick-borne pathogens. This study was conducted to determine the effects of repeated infestations with pathogen-free I. scapularis nymphs on the production of the macrophage cytokines interleukin (IL)-1beta and tumor necrosis factor-alpha and the T lymphocyte cytokines IL-2, IL-4, IL-10, and interferon-gamma in both BALB/c and C3H/HeN mice. The pattern of T lymphocyte cytokine production was evaluated to determine if repeated tick infestation polarizes the immune response toward a Th-1 or Th-2 cytokine profile. Female BALB/c and C3H/HeN mice were infested one to four times with pathogen-free I. scapularis nymphs, with a 14-day tick-free period between each exposure. After each infestation, tick biology parameters were measured and macrophage and T lymphocyte cytokine production was assessed. Elaboration of T lymphocyte and macrophage cytokines was quantitated by antigen capture enzyme-linked immunosorbent assay. Acquired resistance to I. scapularis feeding was not developed by either mouse strain. Significant differences in cytokine production were observed between infested and noninfested mice, as well as between the two mouse strains, following tick infestation. Infestation of both strains with pathogen-free I. scapularis results in a polarization of the host immune response toward a Th-2, anti-inflammatory pattern, with a corresponding suppression of Th-1 responses.

Animals↗

PubMed2006

Study of the three-way interaction between Trichoderma atroviride, plant and fungal pathogens by using a proteomic approach.

The main molecular factors involved in the complex interactions occurring between plants (bean), two different fungal pathogens (Botrytis cinerea, Rhizoctonia solani) and an antagonistic strain of the genus Trichoderma were investigated. Two-dimensional (2-D) electrophoresis was used to analyze separately collected proteomes from each single, two- or three-partner interaction (i.e., plant, pathogenic and antagonistic fungus alone and in all possible combinations). Differential proteins were subjected to mass spectrometry and in silico analysis to search for homologies with known proteins. In the plant proteome, specific pathogenesis-related proteins and other disease-related factors (i.e., potential resistance genes) seem to be associated with the interaction with either one of the two pathogens and/or T. atroviride. This finding is in agreement with the demonstrated ability of Trichoderma spp. to induce systemic resistance against various microbial pathogens. On the other side, many differential proteins obtained from the T. atroviride interaction proteome showed interesting homologies with a fungal hydrophobin, ABC transporters, etc. Virulence factors, like cyclophilins, were up-regulated in the pathogen proteome during the interaction with the plant alone or with the antagonist too. We isolated and confidently identified a large number of protein factors associated to the multi-player interactions examined.

Amino Acid Sequence↗

PubMed1995

Development of a numeric Health Care Worker Risk-Assessment Scale to evaluate potential for blood-borne pathogen exposures.

BACKGROUND: An attempt to develop a Health Care Worker Risk Assessment Scale to evaluate potential for exposure to blood-borne pathogens was made in late 1989 through 1990. The research questions were as follows: (1) Can a scale be developed to assign weights to variables that influence health care workers' risk of exposure to blood-borne pathogens? (2) If so, what variables would be included? METHODS: A five-round Delphi technique was used with 26 panel members from 15 U.S. states and the United Kingdom who were recognized experts in strategies to reduce health care workers' risk of exposure to blood-borne pathogens. The scale included four elements, each scored up to 40 points. Elements were as follows: (1) potential route of exposure, (2) experience of health care worker and cooperation of patient, (3) prevalence of blood-borne pathogens, and (4) difficulty in managing the situation. A minimum score of 20 indicated an extremely low-risk situation; a maximum score of 160 indicated an extremely high-risk situation. RESULTS: Consensus was achieved among the panel members in identifying the elements that contributed to risk for exposure to blood-borne pathogens and in applying the scale to carefully worded vignettes. This required several modifications of both the scale and the vignettes to ensure consistent interpretation of the terms used. In all vignette situations, the risk-abatement strategy was specific to the situation depicted in the vignette and not to the task itself; the value of a numeric scale is thus questionable. CONCLUSIONS: Even with the participation of 26 expert panelists, we were unable to develop a numeric scale to objectively quantify risk in such a way that risk-reduction strategies could be based on the scale rather than on the specific risk elements in a situation. Instead of attempting to use a scale such as this to quantify risk objectively, educators or clinicians may be better advised to teach health care workers the four scale elements so that health care workers can subjectively use these elements to evaluate and modify their own risk situations.

Blood-Borne Pathogens↗

PubMed2026

Genomic insights into preantibiotic osteomyelitis pathogens and their link to current resistant hospital strains.

OBJECTIVES: Osteomyelitis is a severe bone infection that was frequently fatal before the introduction of antibiotics and remains a significant healthcare burden today. Staphylococcus aureus is the most common cause, alongside other hospital-acquired pathogens. Despite their clinical importance, the evolutionary history of these bacteria remains poorly understood. We investigated historical osteomyelitis specimens to identify causative pathogens and characterise their genomes, virulence and antimicrobial resistance (AMR). METHODS: Seven osteomyelitis-affected bones from adults dating to 19th-20th century Germany were analysed using ancient DNA (aDNA) approaches. After sequencing and screening, candidate pathogens were prioritised based on authentic aDNA damage patterns, established association with osteomyelitis and exclusion as environmental contaminants. Identified species were characterised by phylogenetics, multilocus sequence typing and virulence/AMR profiling. RESULTS: In four patients, we detected authentic aDNA from Acinetobacter baumannii, S. aureus or Streptococcus pyogenes. Detected taxa in the remaining three patients did not fulfil the criteria for further analysis. Two patients carried A. baumannii genomes clustering closely with modern avian and freshwater isolates. Both harboured virulence genes, alongside intrinsic efflux pumps and β-lactamases. One patient carried an S. aureus strain belonging to the globally disseminated clonal complex 30, responsible for outbreaks since the 1950s. Molecular dating indicated that this strain diverged from the wider lineage around 1800, placing it among the earliest members of this group. It encoded multiple virulence genes, but no methicillin resistance genes. The fourth patient carried an S. pyogenes strain related to modern epidemic lineages from North America, encoding conserved virulence factors, but no AMR genes. CONCLUSIONS: These specimens provide a window into the evolution of osteomyelitis pathogens. Although modern developments such as widespread antibiotic use have intensified the global resistance crisis, our findings indicate that the genetic foundations for pathogenicity and resistance were already present more than 100 years ago.

Ancient DNA↗

PubMed2006

Proteomic survey of the pathogenic Mycoplasma hyopneumoniae strain 7448 and identification of novel post-translationally modified and antigenic proteins.

Mycoplasma hyopneumoniae is an important pathogen for pigs, being the causative agent of enzootic pneumonia. Recently, the genome sequences of three strains, J, 7448 and 232 have been reported. Here, we describe the results of a proteomic analysis, based on two-dimensional gel electrophoresis of soluble protein extracts, immunoblot and mass spectrometry, which was carried out aiming the identification of gene products and antigenic proteins from the M. hyopneumoniae pathogenic strain 7448. A preliminary M. hyopneumoniae proteome map in two pH ranges (3-10 and 4-7) was produced. A total of 31 different coding DNA sequences (CDSs), including three hypothetical ones, were experimentally verified with the identification of the corresponding protein products by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. According to the Clusters of Orthologous Groups (COG) functional classification, the identified proteins were assigned to the groups of metabolism (13), cellular processes (5) and information and storage processing (4). Nine of the identified proteins were not classifiable by COG, including some related to cytoadherence and possibly involved in pathogenicity. Moreover, at least five highly antigenic proteins of M. hyopneumoniae were identified by immunoblots, including four novel ones (a heat shock protein 70, an elongation factor Tu, a pyruvate dehydrogenase E1-beta subunit and the P76 membrane protein). The now available proteome map is expected to serve as a reference for comparative analyses between M. hyopneumoniae pathogenic and non-pathogenic strains, and for methabolic studies based on cells cultured under modified conditions.

Animals↗

PubMed2003

Pathogenicity of Cryptosporidium parvum--evaluation of an animal infection model.

With the intention of developing a standardised method for assessment of pathogenicity of Cryptosporidium parvum, the CPB-0 isolate was studied by propagation in 1-day-old calves followed by inoculation into specific pathogen free (SPF) piglets. The experiment was repeated. Diarrhoea and shedding of oocysts were seen in all animals infected with the CPB-0 isolate. Clinical signs included depression, inappetence, vomiting (exclusively in the piglets), and death. Histological examination at 17 and 19 days post-infection revealed parasitic stages and microscopic changes primarily restricted to colon and rectum. The unintended presence of rotavirus in some of the experimental animals revealed an additive or synergistic effect between rotavirus and C. parvum as indicated by prolonged diarrhoea, increased oocyst shedding, decreased weight gain and elevated levels of serum haptoglobin and serum amyloid A (SAA) in piglets infected simultaneously with both pathogens. The difference in daily weight gain between infected and control animals was significant only for piglets co-infected with rotavirus. The acute phase response of haptoglobin and SAA was characterised by a large individual variation. In piglets, co-infected with rotavirus, the levels of serum haptoglobin were 3.5 and 4.6 times higher in the infected versus the controls 6 and 9dpi, respectively (mean values: 2411microg/ml+/-S.D. 2023 and 1840 microg/ml+/-S.D. 1697). In the controls infected with rotavirus, peak haptoglobin concentration was seen 3dpi (mean: 1022 microg/ml+/-S.D. 425). Elevated levels of SAA were seen in 1 of 6 piglets infected with C. parvum, and in 5 of 6 piglets co-infected with rotavirus. Tumour necrosis factor alpha (TNFalpha) was undetectable in all serum samples from piglets. The obvious advantages of the SPF pig model are the naturally acquired intestinal microflora, the development of distinct clinical signs similar to cryptosporidiosis in humans and calves, the size of the animals, and the accessibility of individuals born within a short time span. This makes the model ideal for dose-response studies, evaluation of therapeutic agents as well as for assessment of differences in the clinical response to isolates of diverse genetic background. In conclusion, it was shown that the CPB-0 isolate was pathogenic to calves and piglets at a dose of 2.5 x 10(5) oocysts, and that the clinical signs could be replicated during separate experiments. Moreover, diarrhoea, oocyst shedding, body weight changes, histological alterations, and the acute phase response of haptoglobin and SAA were identified as useful parameters for discrimination of isolate-specific differences of pathogenicity.

Animals↗

PubMedDate not supplied

Pathogenicity of Australian strains of avian infectious bronchitis virus.

The pathogenicity of 25 strains of infectious bronchitis virus (IBV) isolated in Australia between 1961 and 1994 was compared in white leghorn specific pathogen-free chicks. Twelve strains were nephropathogenic and 10 respiratory, the other three being of mixed pathogenicity. The IBV strains identified as nephropathogenic induced clinical nephritis, gross and histological kidney lesions, and mortality of 5-90%. According to the severity of these features, the nephropathogenic strains could be further subdivided into strains of high, moderate or low pathogenicity. The three strains of mixed pathogenicity induced tracheitis, mild clinical nephritis and kidney lesions but no mortality. The 10 respiratory strains caused histological lesions in the trachea but not in the kidney, and did not induce clinical nephritis or mortality. Of 12 IBV strains isolated between 1961 and 1976, nine were nephropathogenic, inducing mortality of 15-90%. In contrast, of 13 strains isolated between 1981 and 1994, only three were nephropathogenic, inducing mortality of 5-37%, whereas nine were respiratory. Seven of these nine strains, unlike other respiratory strains, failed completely to replicate in the kidney. The results indicated a change in the prevalent IBV strains from highly nephropathogenic (1960s to 1970s) to respiratory (1980s to early 1990s); moreover, the late 1980s saw the emergence of respiratory strains with altered tissue tropism.

Animals↗

PubMed2004

Complying with the Occupational Safety and Health Administration's Bloodborne Pathogens Standard: implementing needleless systems and intravenous safety devices.

Preventing the transmission of bloodborne pathogens to healthcare workers has been a mission and a challenge of the healthcare industry for over 20 years. The development of the Occupational Safety and Health Administration Bloodborne Pathogens Standard in 1991 and the passing of the Needlestick Safety Act in 2000 mandated hospitals to develop an Exposure Control Plan to protect workers from these pathogens. Children's Hospital Boston began implementation of a needleless system in 1993. Employees readily accepted these systems into practice, because they were convenient and easy to use. A marked decrease in exposures to bloodborne pathogens naturally followed, which is consistent with the national data. The transition to intravenous (i.v.) safety devices at Children's Hospital began in 2000 and proved to be more of a challenge. First, the clinicians must choose a safety product, which requires developing and implementing a trial plan with potential catheters. This selection process is especially difficult in pediatrics where successful placement of the smallest-gauge catheter, no. 24, is imperative. After choosing an i.v. safety product, successful transition is dependent upon the thoroughness of i.v. safety device training and a commitment by the clinicians to the use of these products. Although the number of needlestick injuries and subsequent transmission of bloodborne pathogens have been further reduced with the use of i.v. safety devices, needlestick injuries still occur. This results from a lack of familiarity with the engineering of the device and therefore poor technique or a failure to activate the safety mechanism. Staff resistance due to loss of expertise with the new device and patient care concerns are additional barriers to the use of these new products. Addressing these obstacles and providing adequate training for all clinicians were required for successful implementation of these i.v. safety devices.

Attitude of Health Personnel↗

PubMed2026

Public Health Indoor Air Surveillance for Respiratory Pathogens: From Pilot to Citywide Implementation.

CONTEXT: Environmental surveillance has become an essential component of public health pathogen surveillance programs. Indoor air surveillance is a promising environmental surveillance method but has yet to be scaled citywide and incorporated into state and local public health programs. PROGRAM: The Chicago Department of Public Health established a citywide indoor air surveillance program to enhance monitoring of airborne pathogens and address gaps in existing surveillance. IMPLEMENTATION: The program began with a pilot phase from February to April 2023 at 5 sites, which informed expansion to 17 sites and 20 samplers across emergency departments (5), congregate (3), and community settings (15), across the city. Site staff conducted weekly cartridge exchanges for seven-day sample collection periods using AerosolSense and AirPrep Cub samplers, which were then processed at the Regional Innovative Public Health Laboratory for SARS-CoV-2, influenza, and respiratory syncytial virus. Samples were tested using quantitative polymerase chain reaction, and SARS-CoV-2-positive samples underwent whole genome sequencing to characterize circulating viral lineages. EVALUATION: From February 2023 to August 2025, 1246 samples were processed, with a mean compliance of 85% (SD = 0.149) for weekly cartridge exchanges and minimal operational disruption. The program data supported its use as a surveillance tool for respiratory pathogen detection and SARS-CoV-2 lineage monitoring, with 74% samples positive for at least 1 virus and 68% detecting SARS-CoV-2. DISCUSSION: The program successfully scaled to citywide coverage and was shown to be feasible and acceptable across sites. These results highlight the value of indoor air monitoring as a complementary surveillance tool and offer a framework for other jurisdictions seeking to enhance respiratory pathogen detection through establishing a citywide indoor air surveillance program. Facility-level sampling is aggregated across sites to capture citywide trends complementing clinical and wastewater surveillance, and provides insights into facility-level pathogen burden, not captured by other surveillance methods.

Humans↗

PubMed2006

Photochemical treatment of plasma with amotosalen and long-wavelength ultraviolet light inactivates pathogens while retaining coagulation function.

BACKGROUND: The INTERCEPT Blood System, a photochemical treatment (PCT) process, has been developed to inactivate pathogens in platelet concentrates. These studies evaluated the efficacy of PCT to inactivate pathogens in plasma and the effect of PCT on plasma function. STUDY DESIGN AND METHODS: Jumbo (600 mL) plasma units were inoculated with high titers of test pathogens and treated with 150 micromol per L amotosalen and 3 J per cm(2) long-wavelength ultraviolet light. The viability of each pathogen before and after treatment was measured with biological assays. Plasma function was evaluated through measurement of coagulation factors and antithrombotic protein activities. RESULTS: The levels of inactivation expressed as log-reduction were as follows: cell-free human immunodeficiency virus-1 (HIV-1), greater than 6.8; cell-associated HIV-1, greater than 6.4; human T-lymphotropic virus-I (HTLV-I), 4.5; HTLV-II, greater than 5.7; hepatitis B virus (HBV) and hepatitis C virus, greater than 4.5; duck HBV, 4.4 to 4.5; bovine viral diarrhea virus, 6.0; severe acute respiratory syndrome coronavirus, 5.5; West Nile virus, 6.8; bluetongue virus, 5.1; human adenovirus 5, 6.8; Klebsiella pneumoniae, greater than 7.4; Staphylococcus epidermidis and Yersinia enterocolitica, greater than 7.3; Treponema pallidum, greater than 5.9; Borrelia burgdorferi, greater than 10.6; Plasmodium falciparum, 6.9; Trypanosoma cruzi, greater than 5.0; and Babesia microti, greater than 5.3. Retention of coagulation factor activity after PCT was expressed as the proportion of pretreatment (baseline) activity. Retention was 72 to 73 percent of baseline fibrinogen and Factor (F)VIII activity and 78 to 98 percent for FII, FV, FVII, F IX, FX, FXI, FXIII, protein C, protein S, antithrombin, and alpha2-antiplasmin. CONCLUSION: PCT of plasma inactivated high levels of a wide range of pathogens while maintaining adequate coagulation function. PCT has the potential to reduce the risk of transfusion-transmitted diseases in patients requiring plasma transfusion support.

Animals↗

PubMed1985

Myelopoiesis in experimentally contaminated specific-pathogen-free and germfree mice during oral administration of polymyxin.

Oral administration of polymyxin to specific-pathogen-free C3H/Law mice which with previously contaminated with gram-negative bacteria resulted in complete suppression of cecal gram-negative bacteria. Suppression of cecal gram-negative bacteria was accompanied by reduction of the cecal endotoxin concentration from 10 to 1 microgram/g of cecal content as measured with a microtechnique for the Limulus amebocyte lysate assay. Endotoxin determination by this assay appeared to be unaffected by the amount of polymyxin present in cecal preparations after oral administration of this antibiotic. In experimentally contaminated specific-pathogen-free mice, the femoral concentration of progenitor cells forming granulocyte-macrophage colonies in vitro (CFU-GM) decreased significantly (P less than 0.001) to 66% of the initial control after 4 days of polymyxin treatment. However, the femoral CFU-GM concentration in germfree mice and splenic CFU-GM concentration in experimentally contaminated specific-pathogen-free and germfree mice was not affected by polymyxin treatment. The kinetic behavior of femoral and splenic CFU-GM in experimentally contaminated specific-pathogen-free and germfree mice was expressed as the in vivo sensitivity to the S-phase-specific cytostatic drug hydroxyurea, i.e., the hydroxyurea kill. Administration of polymyxin to experimentally contaminated specific-pathogen-free mice significantly diminished the hydroxyurea kill of femoral CFU-GM from 29 to 13% (P less than 0.02) and of splenic CFU-GM from 53 to 27% (P less than 0.005). The hydroxyurea kill of femoral CFU-GM in germfree mice was not significantly affected by polymyxin treatment. On basis of these results we conclude that the effect of polymyxin treatment on myelopoiesis is most likely due to elimination of intestinal gram-negative bacteria and may indicate a significant role of intestinal gram-negative bacteria in the regulation of myelopoiesis.

Animals↗

PubMed2003

Using active learning strategies to present bloodborne pathogen programs.

Every year, school nurses have the responsibility for developing and presenting a bloodborne pathogen presentation to the education and clerical staff of their buildings. Although the information is similar from year to year, the manner in which the information is presented can be altered. Teachers are using active learning strategies in a variety of learning environments, engaging students in the learning process by having them play an active role. With some planning, preparation, and imagination, active learning strategies can be incorporated into bloodborne pathogen presentations. The purpose of this article is to define active learning, describe how to develop a program using active learning strategies, and provide some examples of bloodborne pathogen presentations that have already been developed. Several sources are identified that can provide the school nurse with information regarding bloodborne pathogens. Information about how computers can be integrated into the bloodborne pathogen presentation is also presented.

Blood-Borne Pathogens↗

PubMed2026

Metagenomic next-generation sequencing of cerebrospinal fluid reveals pathogen spectrum and mortality predictors among patients with advanced HIV-1 disease at a tertiary hospital in China.

BACKGROUND: Central nervous system (CNS) infections remain the major causes of morbidity and mortality among people living with HIV-1 (PLWH), particularly in resource-limited settings. However, the clinical characteristics and prognostic indicators of PLWH with suspected CNS infections are not well defined. In this study, we aim to characterize the spectrum of CNS pathogens, clinical characteristics, in-hospital mortality, and factors associated with death among people with advanced HIV-1 disease (AHD) in Guangxi, China. METHODS: Metagenomic next-generation sequencing (mNGS) was performed to analyze types of infection in cerebrospinal fluid (CSF) from 61 treatment-naive PLWH with suspected CNS infections. Clinical data, routine laboratory tests, and biochemical tests were collected and analyzed. RESULTS: Among the 61 CSF samples, primarily with AHD, a total of 206 pathogens were identified. Viral pathogens predominated, with Epstein-Barr virus being the most frequently identified, followed by cytomegalovirus. Compared with patients with single-pathogen infection, those with multiple infections (viral, bacterial, and fungal) exhibited significantly lower CD4 T cell counts, higher C-reactive protein levels, and markedly reduced lipid metabolism parameters. However, infection types were not significantly associated with in-hospital death. Multivariate logistic regression analysis identified plasma low density lipoprotein (LDL) and CSF lactate dehydrogenase (LDH) as independent predictors of in-hospital death. CONCLUSION: In PLWH with AHD and suspected CNS infections, multiple pathogens frequently coexist in the CSF. Plasma LDL and CSF LDH levels were independent predictors of death, indicating their potential value as early risk stratification in AHD.

Humans↗

PubMed2000

Serological monitoring on layer farms with specific pathogen-free chickens.

To monitor the existence of avian pathogens in laying chicken flocks, specific pathogen-free (SPF) chickens were introduced into two layer farms and reared with laying hens for 12 months. SPF chickens were bled several times after their introduction and examined for their sero-conversion to avian pathogens. As a result, antibodies to eight or ten kinds of pathogens were detected in SPF chickens on each farm. Antibodies to infectious bronchitis virus (IBV), avian nephritis virus, Mycoplasma gallisepticum and M. synoviae were detected early within the first month. Antibody titer to IBV suggested that the laying chickens were infected with IBV repeatedly during the experiment on both farms. However, antibodies to infectious bursal disease virus and 6 pathogens were not detected.

Animals↗

PubMed2004

Economics of pathogen inactivation technology for platelet concentrates in Japan.

Residual risk of transmitting recognized and emerging blood-borne pathogens via blood transfusion in Japan persists despite advances in blood safety screening. The INTERCEPT Blood System (IBS) for platelets was developed to inactivate a broad spectrum of pathogens to reduce the risk of transfusion-transmitted infections. In this study we assessed the economic impact of the IBS on platelet transfusion costs. An economic analysis model was used to assess both net cost and cost-effectiveness of the IBS for the patient populations accounting for most of the platelet use in Japan. Pathogen exposure included viruses currently recognized to cause transfusion-transmitted infections and emerging pathogens of potential significance for transfusion-transmitted infections. Economic assessment of the full potential of the IBS revealed that only a small increase in net cost can be expected with implementation. The cost-effectiveness of the IBS for platelets is comparable with and potentially better than that of other blood safety interventions (eg, nucleic acid testing) and, in general, other recently implemented safety interventions (eg, chemical regulations and traffic safety measures) accepted as valuable in Japan. Thus a preventive approach using pathogen inactivation with the IBS may be considered a desirable strategy for improving the current safety of platelet transfusions in Japan.

Bacterial Infections↗

PubMedDate not supplied

Experimental gizzard erosions in specific-pathogen-free chicks by serotype 1 group I avian adenoviruses from broilers.

The pathogenicity of serotype 1 group I avian adenovirus (GIAAV) strains isolated from gizzard erosions for 1-wk-old specific-pathogen-free (SPF) chickens was investigated. In Experiment 1, SPF chickens inoculated orally with a serotype 1 strain (Tokushima2000/GE) of GIAAV isolated from gizzard erosion in broilers were euthanatized and necropsied from 3 to 12 days after inoculation. Clinically, there were no significant signs in the chickens inoculated with Tokushima strain. The gizzards were found macroscopically to be dilated with liquefied contents. The koilin layer of the gizzard exhibited multifocal white lesions with occasional erosions. Gross lesions of the koilin layer (white foci and erosion) appeared at 3 days after inoculation and persisted until 12 days after inoculation. The gross lesions were most severe at 9 days after inoculation. Histologically, multifocal degeneration, necrosis, and loss of the glandular epithelial cells with intranuclear inclusions, liquefactive change of koilin substance, and erosive lesions of koilin layers and surface epithelium of the gizzards were observed. Macrophages increased in the focal areas of the lamina propriabelow the liquefactive koilin substances. Immunohistochemically, intranudear inclusions were positive against GIAAV antigen. Histologic lesions of gizzards were most severe at 7 and 9 days after inoculation, but the frequency of intranuclear inclusions was greatest at 5 days after inoculation. In Experiment 2, the pathogenicities of four strains of serotype 1 GIAAV for 1-wk-old SPF chickens were compared. Three strains isolated from gizzard erosion had similar pathogenicities but one strain from a normal chicken was not pathogenic for chickens. These results suggest that gizzard erosions by serotype 1 GIAAV infection may occur in broiler chickens in Japan.

Adenoviridae Infections↗

PubMed1999

Rhesus monkey (Macaca mulatta) model of Helicobacter pylori: noninvasive detection and derivation of specific-pathogen-free monkeys.

BACKGROUND AND PURPOSE: Development of the rhesus monkey model of Helicobacter pylori has been hampered by problems with serodetection and by the difficulty of identifying specific-pathogen (Helicobacter)-free animals. Our purpose was to determine whether detection could be improved and to determine if pathogen-free monkeys could be derived by nursery rearing. METHODS: An enzyme-linked immunoabsorbent assay (ELISA) and a [14C]urea breath test were compared to endoscopy to determine H. pylori infection status in rhesus macaques; 18 animals were hand raised in the nursery to determine whether pathogen-free animals could be selected. RESULTS: Helicobacter pylori infection was common in colony-raised young rhesus monkeys and was nearly universal by adulthood. Serodetection, using antigen from rhesus-derived H. pylori strains, was 95% sensitive and 94% specific. The [14C]urea breath test was 96% sensitive and 88% specific for detection of chronic Helicobacter infection in rhesus monkeys. Segregation of newborn animals within the first 24 h of life was a reliable method to obtain pathogen-free rhesus monkeys. CONCLUSION: Isolation of specific-pathogen-free animals, together with better detection methods, may improve the value of the rhesus monkey model for the study of H. pylori pathogenesis, immune response, and vaccine development.

Animals↗

PubMed2000

The use of riboflavin for the inactivation of pathogens in blood products.

BACKGROUND AND OBJECTIVES: In recent years, the desire to develop methods to inactivate pathogens in blood components has continued to grow. Several of these proposed approaches have been introduced or are currently in clinical studies. The use of chemical inactivating agents must be considered in terms of the current safety of the blood supply and the potential risks that the introduction of new chemical entities into blood components may carry. The impact which these treatment procedures have on the in vitro and in vivo performance of these products must also be considered relative to the potential benefit of the pathogen inactivation potential they offer. This paper will discuss one possible approach for inactivating pathogens in blood using vitamin B2, Riboflavin, and light. MATERIALS AND METHODS: We have used Riboflavin for treating plasma and platelets and evaluated protein quality and platelet function in vitro. Initial toxicology tests to assess the impact of infusion of photoproducts generated in these processes have also been conducted in rodents. Cytotoxicity evaluations have been used to assess the possible impact of photoproduct toxicity in vivo. Virus and bacteria spiking studies using a variety of human and animal model pathogens have been conducted in order to asses the efficacy of this process. RESULTS: Initial toxicology assessment of the photoproducts of Riboflavin generated under the proposed treatment conditions have been favorable. Virus and bacteria clearance studies have demonstrated efficacy of the procedure against a wide range of human and animal pathogens, including intracellular HIV-1. Studies with platelet and plasma function indicated reductions in vitro comparable to other proposed treatment approaches. CONCLUSION: The use of Riboflavin in a photochemical decontamination process for blood components shows promise.

Blood Platelets↗