Cutaneous squamous cell carcinoma characterized by MALDI mass spectrometry imaging in combination with machine learning

Cutaneous squamous cell carcinoma (SCC) is an increasingly prevalent global health concern. Current diagnostic and surgical methods are reliable, but they require considerable resources and do not provide metabolomic insight. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) enables detailed, spatially resolved metabolomic analysis of tissue samples. Integrated with machine learning, MALDI-MSI could yield detailed information pertaining to the metabolic alterations characteristic for SCC. These insights have the potential to enhance SCC diagnosis and therapy, improving patient outcomes while tackling the growing disease burden. This study employs MALDI-MSI data, labelled according to histology, to train a supervised machine learning model (logistic regression) for the recognition and delineation of SCC. The model, based on data acquired from discrete tumor sections (n = 25) from a mouse model of SCC, achieved a predictive accuracy of 92.3% during cross-validation on the labelled data. A pathologist unacquainted with the dataset and tasked with evaluating the predictive power of the model in the unlabelled regions, agreed with the model prediction for over 99% of the tissue areas. These findings highlight the potential value of integrating MALDI-MSI with machine learning to characterize and delineate SCC, suggesting a promising direction for the advancement of mass spectrometry techniques in the clinical diagnosis of SCC and related keratinocyte carcinomas.

The potential of sheep in preclinical models for bone infection research - A systematic review

Background

Reliable animal models are critical for preclinical research and should closely mimic the disease. With respect to route of infection, pathogenic agent, disease progression, clinical signs, and histopathological changes. Sheep have similar bone micro- and macrostructure as well as comparable biomechanical characteristics to humans. Their use in bone research is established, however their use in bone infection research is limited. This systematic review will summarise the key features of the available bone infection models using sheep, providing a reference for further development, validation, and application.

Method

This systematic review was designed according to the PRISMA guidelines and registered with PROSPERO. Quality was assessed using SYRICLE's risk of bias tool adapted for animal studies. PubMed, MEDLINE, Web of Science and EMBASE were searched until March 2022.1921 articles were screened by two independent reviewers, and 25 were included for analysis.

Results

Models have been developed in nine different breeds. Staphylococcus aureus was used in the majority of models, typically inoculating 108 colony forming units in tibial or femoral cortical defects. Infection was established with either planktonic or biofilm adherent bacteria, with or without foreign material implanted. Most studies used both radiological and microbiological analyses to confirm osteomyelitis.

Conclusions

There is convincing evidence supporting the use of sheep in bone infection models of clinical disease. The majority of sheep studied demonstrated convincing osteomyelitis and tolerated the infection with minimal complications. Furthermore, the advantages of comparable biology and biomechanics may increase the success for translating in vivo results to successful therapies.

The Translational potential of this article

In the realm of preclinical research, the translation to viable clinical therapies is often perilous, and the quest for reliable and representative animal models remains paramount. This systematic review accentuates the largely untapped potential of sheep as large animal models, especially in bone infection research. The anatomical and biomechanical parallels between sheep and human bone structures position sheep as an invaluable asset for studying osteomyelitis and periprosthetic joint infection. This comprehensive exploration of the literature demonstrates the robustness and translational promise of these models. Furthermore, this article underscores the potential applicability for sheep in developing effective therapeutic strategies for human bone infections.

Clinicopathologic evaluation of congenital idiopathic megaesophagus in a Gordon Setter puppy: a case report and development and application of peripherin immunohistochemistry for detection of ganglion cells

We examined a case of congenital idiopathic megaesophagus (CIM) in a 5-wk-old female Gordon Setter puppy by means of contrast radiography, autopsy, histopathology, and immunohistochemistry. Clinical and radiologic findings included weight stagnation and marked generalized esophageal dilation with ventral displacement of the heart and lungs. These findings were confirmed at autopsy, and segments of the thoracic esophagus were sampled for histopathology. On histopathology, diffuse esophageal muscular atrophy, mucosal erosions, mononuclear inflammation, and a marked reduction in the number of myenteric plexus structures and number of ganglion cells were present (aganglionosis). The latter was determined immunohistochemically using an anti-peripherin antibody as the primary reagent, which provides a strong tool for the histologic confirmation of CIM. The histologic findings share some similarities to lesions associated with megaesophagus in Friesian foals, as well as esophageal achalasia and Hirschsprung disease in humans.

Pathological Diagnosis of Pulmonary Aspergillosis

Pulmonary aspergillosis constitutes an increasingly prevalent and potentially fatal complex of mycotic diseases, caused by different species of Aspergillus. The broad spectrum of pathological manifestations associated with pulmonary aspergillosis necessitates a differentiation of commensalism from saprophytic colonization, hypersensitivity reactions, and true invasive infections, which highlights the importance of histopathology as a gold standard in a diagnostic setting. For the past decades, changes in terminology and contradicting contributions from different diagnostic disciplines have made the classification of pulmonary aspergillosis rather confusing. This review offers a categorization of aspergillosis lesions based on what can be histopathologically identified and distinguished, differentiating between acute invasive infection and forms of subacute, chronic, and allergic diseases and coinfections, and summarizes important manifestations of lesions associated with the different forms of pulmonary aspergillosis.

The avian influenza A virus receptor SA-α2,3-Gal is expressed in the porcine nasal mucosa sustaining the pig as a mixing vessel for new influenza viruses

Influenza A viruses (IAVs) originate from wild birds but have on several occasions jumped host barriers and are now also circulating in humans and mammals. The IAV host receptors (glycans with galactose linked to a sialic acid (SA) in an α2,3 or α2,6 linkage) are crucial host factors restricting inter-species transmission. In general, avian-origin IAVs show a preference for SA-α2,3 (avian receptor), whereas IAVs isolated from humans and pigs prefer SA-α2,6 (human receptor). N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc) are the two major SAs. Neu5Ac is expressed in all species, whereas Neu5Gc is only expressed in a limited number of domestic species such as pigs and horses, but not in humans. Despite that previous studies have shown that the IAV host receptor distribution appears to be similar in pigs and humans, none of these studies have investigated the expression of Neu5Gc-α2,6 in situ in porcine tissues. Thus, the aim of this study was to elucidate the distribution of IAV host receptors expressed in the porcine respiratory tract and relate the expression to the viral tropism of diverse host-adapted IAVs. The IAV receptor (SA-α2,3 and SA-α2,6) distribution and the presence of specifically Neu5Gc-α2,6 in the porcine nasal, tracheal, and lung tissues was investigated by lectin histochemistry. Furthermore, IAV immunohistochemistry was performed on tissues from pigs experimentally infected with IAVs, either adapted to pigs or humans, to investigate the significance of the IAV host receptors and the tropism of the diverse host-adapted IAVs. We document for the first time the expression of the avian receptor on the surface of the porcine nasal mucosa and an equal expression of Neu5Ac-α2,6 and Neu5Gc-α2,6 on the surface of the tracheal epithelium and alveoli. In all IAV-infected pigs, we found a low amount of IAV-positive cells in the trachea despite a high expression of the human receptor. Cumulatively, these findings suggest that optimal IAV replication involves a complex interplay between the viruses and their host receptors and that there might be other less clearly defined host factors that determine the site of replication.

Experimental infection of pigs and ferrets with "pre-pandemic," human-adapted, and swine-adapted variants of the H1N1pdm09 influenza A virus reveals significant differences in viral dynamics and pathological manifestations

Influenza A viruses are RNA viruses that cause epidemics in humans and are enzootic in the pig population globally. In 2009, pig-to-human transmission of a reassortant H1N1 virus (H1N1pdm09) caused the first influenza pandemic of the 21st century. This study investigated the infection dynamics, pathogenesis, and lesions in pigs and ferrets inoculated with natural isolates of swine-adapted, human-adapted, and "pre-pandemic" H1N1pdm09 viruses. Additionally, the direct-contact and aerosol transmission properties of the three H1N1pdm09 isolates were assessed in ferrets. In pigs, inoculated ferrets, and ferrets infected by direct contact with inoculated ferrets, the pre-pandemic H1N1pdm09 virus induced an intermediary viral load, caused the most severe lesions, and had the highest clinical impact. The swine-adapted H1N1pdm09 virus induced the highest viral load, caused intermediary lesions, and had the least clinical impact in pigs. The human-adapted H1N1pdm09 virus induced the highest viral load, caused the mildest lesions, and had the least clinical impact in ferrets infected by direct contact. The discrepancy between viral load and clinical impact presumably reflects the importance of viral host adaptation. Interestingly, the swine-adapted H1N1pdm09 virus was transmitted by aerosols to two-thirds of the ferrets. Further work is needed to assess the risk of human-to-human aerosol transmission of swine-adapted H1N1pdm09 viruses.

Loss of the KN Motif and AnKyrin Repeat Domain 1 (KANK1) Leads to Lymphoid Compartment Dysregulation in Murine Model

The KN Motif and AnKyrin Repeat Domain 1 (KANK1) is proposed as a tumour suppressor gene, as its expression is reduced or absent in several types of tumour tissue, and over-expressing the protein inhibited the proliferation of tumour cells in solid cancer models. We report a novel germline loss of heterozygosity mutation encompassing the KANK1 gene in a young patient diagnosed with myelodysplastic neoplasm (MDS) with no additional disease-related genomic aberrations. To study the potential role of KANK1 in haematopoiesis, we generated a new transgenic mouse model with a confirmed loss of KANK1 expression. KANK1 knockout mice did not develop any haematological abnormalities; however, the loss of its expression led to alteration in the colony forming and proliferative potential of bone marrow (BM) cells and a decrease in hematopoietic stem and progenitor cells (HSPCs) population frequency. A comprehensive marker expression analysis of lineage cell populations indicated a role for Kank1 in lymphoid cell development, and total protein analysis suggests the involvement of Kank1 in BM cells' cytoskeleton formation and mobility.

Immunohistochemical study of CD31 and α-SMA expression for age estimation of porcine skin wounds

Age estimation of wounds in veterinary forensic investigations is based on the presence and amount of granulation tissue. However, accurate age assessment is challenging and new time-dependent markers are warranted to support and improve the current procedure. The objective of this study was to evaluate the expression of CD31-positive blood vessels and α-smooth muscle action (α-SMA)-positive myofibroblasts in granulation tissue in order to evaluate their value as markers for porcine wound age estimation in a veterinary forensic context. Immunohistochemical expression of CD31 and α-SMA in 14 experimental porcine skin wounds of different ages (4, 6, 8, 10, 18, 27 and 35 days) and 11 forensic porcine wound specimens (of unknown age) were evaluated. CD31-positive blood vessels and α-SMA-positive myofibroblasts were present in the granulation tissue in the experimental wounds at all time points. A significant decrease in the mean blood vessel counts was found in wounds aged 18, 27 and 35 days compared with wounds aged 6 days (P < 0.001), when assessing both the superficial and deep part of the wound bed. α-SMA expression was lower at 27 and 35 days post wounding compared with 6-18 days post wounding. Combined assessment of three parameters (mean blood vessel counts in the superficial and deep wound beds and α-SMA expression) could approximately specify the age of the wounds as either 6-18 days or ≥27 days. In two of the forensic cases a combination of the three parameters yielded results that were similar to the experimental wounds, indicating a wound age of 6-18 days or ≥27 days, respectively. In the remaining forensic cases a combination of the three parameters did not show the same expression pattern as in the experimental wounds. The results indicate that in some forensic cases the application of CD31 and α-SMA markers appeared to support the current procedure for porcine wound age estimation, but this must be combined with pathological characteristics.

Oral phytochemicals as photoprotectants in UVR exposed hairless mice: A study of hesperidin methyl chalcone, phloroglucinol, and syringic acid

Ultraviolet radiation is the primary risk factor for keratinocyte carcinoma. Because of increasing incidence rates, new methods of photoprotection must be explored. Oral supplementation with photoprotective compounds presents a promising alternative. Phytochemical compounds like hesperidin methyl chalcone, phloroglucinol, and syringic acid are particularly of interest because of their antioxidant properties. Our primary outcome was to evaluate the effects of oral phytochemicals on photocarcinogenesis with time until tumour onset as the primary endpoint. A total of 125 hairless C3.Cg-Hrhr/TifBom Tac mice were randomised to receive tap water supplemented with either 100 mg/kg hesperidin methyl chalcone, phloroglucinol, or syringic acid, 600 mg/kg nicotinamide as a positive control, or no supplementation. The mice were irradiated with 3.5 standard erythema doses thrice weekly to induce photocarcinogenesis. Supplementation with the phytochemicals phloroglucinol and syringic acid and nicotinamide delayed tumour onset from a median of 140 days to 151 (p = 0.036), 157 days (p = 0.02), and 178 (p = 2.7·10-5), respectively. Phloroglucinol and nicotinamide supplementation reduced tumour number. Nicotinamide increased UV-induced pigmentation and reduced oedema formation, while phloroglucinol supplementation reduced epidermal thickness. These results indicate that oral supplementation with phloroglucinol and syringic acid protects against photocarcinogenesis in hairless mice, but not to the same extent as nicotinamide.

Effects of Transdermal Fentanyl Treatment on Acute Pain and Inflammation in Rats with Adjuvant-induced Monoarthritis

Eliminating unnecessary pain is an important requirement of performing animal experimentation, including reducing and controlling pain of animals used in pain research. The goal of this study was to refine an adjuvant-induced monoarthritis model in rats by providing analgesia with a transdermal fentanyl solution (TFS). Male and female Sprague-Dawley rats, single- or pair-housed, were injected with 20 μL of complete Freund adjuvant (CFA) into the left ankle joint. CFA-injected rats treated with a single dose of transdermal fentanyl solution (0.33 or 1 mg/kg) were compared with an untreated CFA-injected group and sham groups that received either no treatment or TFS treatment (1 mg/kg) during 72 h. At the tested doses, TFS reduced mechanical hyperalgesia and improved the mobility, stance, rearing, and lameness scores at 6 h after CFA injection. Joint circumferences were not reduced by TFS treatment, and no significant differences were detected between the 2 doses of TFS, or between single- and pair-housed rats. Treatment with TFS did not appear to interfere with model development and characteristics. However, overall, the analgesic effect was transient, and several opioid-related side effects were observed.

Molecular Techniques for Genus and Species Determination of Fungi From Fresh and Paraffin-Embedded Formalin-Fixed Tissue in the Revised EORTC/MSGERC Definitions of Invasive Fungal Infection

The EORTC/MSGERC have revised the definitions for proven, probable, and possible fungal diseases. The tissue diagnosis subcommittee was tasked with determining how and when species can be determined from tissue in the absence of culture. The subcommittee reached a consensus decision that polymerase chain reaction (PCR) from tissue, but not immunohistochemistry or in situ hybridization, can be used for genus or species determination under the new EORTC/MSGERC guidelines, but only when fungal elements are identified by histology. Fungal elements seen in tissue samples by histopathology and identified by PCR followed by sequencing should fulfill the definition of a proven fungal infection, identified to genus/species, even in the absence of culture. This summary discusses the issues that were deliberated by the subcommittee to reach the consensus decision and outlines the criteria a laboratory should follow in order to produce data that meet the EORTC/MSGERC definitions.

Survival of pigs with different characteristics of umbilical outpouching in a prospective cohort study of Danish pigs

Umbilical hernia and other conditions clinically evident as umbilical outpouchings (UOs) affect the welfare and economy in Danish pig production. The objectives of the current study were to characterize the associations between 1) time of detection of the UOs and the odds of dying before scheduled slaughter; 2) time of death, irrespective of the cause, and clinical signs of the UOs, i.e. general condition, size, reducibility, form and skin-color of the UOs; and 3) occurrence of wounds on the UOs and clinical signs: general condition, size, reducibility, form and skin-color. A cohort of Danish conventional pigs with UOs (n = 255) were followed from the detection of an UO until spontaneous death, euthanization or slaughter of the pig. The pigs were clinically examined once a month, and when pigs with an UO died spontaneously, were euthanized or slaughtered, the causes and date of death were recorded. The effects of the clinical manifestations on overall survival were assessed using a Cox proportional hazards model. In total 57 % of the pigs died spontaneously or were euthanized before slaughter. The median age of spontaneous death or euthanasia was 85 days. The UOs were detected at different ages, with half of the pigs (52 %) detected in the farrowing section. No significant association was found between death before scheduled slaughter and the time of detection. Three different clinical manifestations were found to have a prognostic value for overall survival until slaughter, i.e. skin-color of the UO, a general condition of the pig and the size of the UO. An interaction was present between the size and the skin-color of the UO. Wounds on the UO were the most frequent complication resulting in euthanasia (37 %). The odds for developing a wound on the UO were higher for pigs in a general bad condition compared to pigs in a good condition (OR, 5.4; 95 % CL 2.5-11.3), and for pigs with an UO large in size compared to pigs with a small UO (OR, 4.8; 95 % CL 3.0-7.5). The identification of prognostic clinical signs in pigs with an UO is useful in the assessment and decision-making in relation to the future prospects of pigs with UOs.

Revision and Update of the Consensus Definitions of Invasive Fungal Disease From the European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium

BACKGROUND

Invasive fungal diseases (IFDs) remain important causes of morbidity and mortality. The consensus definitions of the Infectious Diseases Group of the European Organization for Research and Treatment of Cancer and the Mycoses Study Group have been of immense value to researchers who conduct clinical trials of antifungals, assess diagnostic tests, and undertake epidemiologic studies. However, their utility has not extended beyond patients with cancer or recipients of stem cell or solid organ transplants. With newer diagnostic techniques available, it was clear that an update of these definitions was essential.

METHODS

To achieve this, 10 working groups looked closely at imaging, laboratory diagnosis, and special populations at risk of IFD. A final version of the manuscript was agreed upon after the groups' findings were presented at a scientific symposium and after a 3-month period for public comment. There were several rounds of discussion before a final version of the manuscript was approved.

RESULTS

There is no change in the classifications of "proven," "probable," and "possible" IFD, although the definition of "probable" has been expanded and the scope of the category "possible" has been diminished. The category of proven IFD can apply to any patient, regardless of whether the patient is immunocompromised. The probable and possible categories are proposed for immunocompromised patients only, except for endemic mycoses.

CONCLUSIONS

These updated definitions of IFDs should prove applicable in clinical, diagnostic, and epidemiologic research of a broader range of patients at high-risk.

Liraglutide Improves the Kidney Function in a Murine Model of Chronic Kidney Disease

BACKGROUND

Chronic kidney disease (CKD) is a global health burden, and the current treatment options only slow down the disease progression. GLP-1 receptor agonists (GLP-1 RA) have shown a renal protective effect in models of CKD; however, the mechanism behind the beneficial effect is not understood. In this study, we investigate the effect of the GLP-1 RA liraglutide in the nephrotoxic serum nephritis (NTN) CKD model. Moreover, we compare the gene expression pattern of liraglutide-treated mice to the gene expression pattern of mice treated with the angiotensin converting enzyme inhibitor, enalapril.

METHODS

The effect of liraglutide was tested in the NTN model by evaluating the glomerular filtration rate (GFR), albuminuria, mesangial expansion, renal fibrosis, and renal inflammation. Furthermore, the regulation of selected genes involved in CKD and in glomerular, cortical tubulointerstitial, and whole kidney structures was analyzed using a gene expression array on samples following laser capture microdissection.

RESULTS

Treatment with liraglutide improved CKD hallmarks including GFR, albuminuria, mesangial expansion, renal inflammation, and renal fibrosis. The gene expression revealed that both liraglutide and enalapril reversed the regulation of several fibrosis and inflammation associated genes, which are also regulated in human CKD patients. Furthermore, liraglutide and enalapril both regulated genes in the kidney involved in blood pressure control.

CONCLUSIONS

Treatment with liraglutide improved the kidney function and diminished renal lesions in NTN-induced mice. Both liraglutide and enalapril reversed the regulation of genes involved in CKD and regulated genes involved in blood pressure control.

Artificial Intelligence-Based Quantification of Epithelial Proliferation in Mammary Glands of Rats and Oviducts of Göttingen Minipigs

Quantitative assessment of proliferation can be an important endpoint in toxicologic pathology. Traditionally, cell proliferation is quantified by labor-intensive manual counting of positive and negative cells after immunohistochemical staining for proliferation markers (eg, Ki67, bromo-2'-deoxyuridine, or proliferating cell nuclear antigen). Currently, there is a lot of interest in replacing manual evaluation of histology end points with image analysis tools based on artificial intelligence. The aim of the present study was to explore if a commercially available image analysis software can be used to quantify epithelial proliferative activity in rat mammary gland and minipig oviduct. First, algorithms based on artificial intelligence were trained to detect epithelium in each tissue. Areas of BrdU- or Ki67-positive nuclei and negative nuclei were subsequently quantified with threshold analysis. Artificial intelligence-based and manually counted labelling indices were strongly correlated and equally well detected the estrous cycle influence on proliferation in mammary gland and oviduct epithelium, as well as the dramatically increased proliferation in rat mammary glands after treatment with estradiol and progesterone. In conclusion, quantification of epithelial proliferation in two reproductive tissues can be achieved in a reliable fashion using image analysis software based on artificial intelligence, thus avoiding time- and labor-intensive manual counting, requiring trained operators.

Receptor Activator of Nuclear Factor kappa-B Ligand is Not Regulated During Chronic Osteomyelitis in Pigs

Bone loss is a major complication of osteomyelitis and from numerous in-vitro studies, it has been concluded that the bone lysis is caused by elevated expression of the receptor activator of nuclear factor κB ligand (RANKL), leading to increased osteoclast activity. However, we failed to find any relationship between bone loss and osseous RANKL expression in a porcine model of acute and chronic implant-associated osteomyelitis (IAO) due to Staphylococcus aureus or in chronic osteomyelitis lesions in slaughter pigs. Surprisingly, we found that the expression of RANKL was reduced during chronic bone infections. This is in line with the few studies conducted on human samples. A significant bone loss was observed in IAO lesions and in lesions from slaughter pigs, but with no indication of osteoclast involvement using histochemistry, immunohistochemistry for RANKL, receptor activator of nuclear factor kappa-B, osteoprotegerin and cathepsin K, and high-throughput quantitative real-time polymerase chain reaction on bone tissue from osteomyelitic lesions. A strong inflammatory response was seen in the infected animals and, therefore, we propose proteolytic enzymes induced by inflammation to be a major component of the bone loss. Furthermore, we found a significant upregulation of the IL26 gene in infected animals, which can inhibit RANKL-induced osteoclastogenesis, but has no homologue in mice. This finding emphasises that neither murine models nor in-vitro studies can mirror human disease development completely. The present study emphasises that the interactions between microorganisms, the immune system and bone cells in osteomyelitis are too complex to be accurately represented by an in-vitro model.

Pathological and microbiological impact of a gentamicin-loaded biocomposite following limited or extensive debridement in a porcine model of osteomyelitis

Aims

CERAMENT|G is an absorbable gentamicin-loaded biocomposite used as an on-site vehicle of antimicrobials for the treatment of chronic osteomyelitis. The purpose of the present study was to investigate the sole effect of CERAMENT|G, i.e. without additional systemic antimicrobial therapy, in relation to a limited or extensive debridement of osteomyelitis lesions in a porcine model.

Methods

Osteomyelitis was induced in nine pigs by inoculation of 10⁴ colony-forming units (CFUs) of Staphylococcus aureus into a drill hole in the right tibia. After one week, the pigs were allocated into three groups. Group A (n = 3) received no treatment during the study period (19 days). Groups B (n = 3) and C (n = 3) received limited or extensive debridement seven days postinoculation, respectively, followed by injection of CERAMENT|G into the bone voids. The pigs were euthanized ten (Group C) and 12 (Group B) days after the intervention.

Results

All animals presented confirmatory signs of bone infection post-mortem. The estimated amount of inflammation was substantially greater in Groups A and B compared to Group C. In both Groups B and C, peptide nucleic acid fluorescence in situ hybridization (PNA FISH) of CERAMENT|G and surrounding bone tissue revealed bacteria embedded in an opaque matrix, i.e. within biofilm. In addition, in Group C, the maximal measured post-mortem gentamicin concentrations in CERAMENT|G and surrounding bone tissue samples were 16.6 μg/ml and 6.2 μg/ml, respectively.

Conclusion

The present study demonstrates that CERAMENT|G cannot be used as a standalone alternative to extensive debridement or be used without the addition of systemic antimicrobials.

Cite this article: Bone Joint Res 2020;9(7):394–401.

Global guideline for the diagnosis and management of mucormycosis: an initiative of the European Confederation of Medical Mycology in cooperation with the Mycoses Study Group Education and Research Consortium

Mucormycosis is a difficult to diagnose rare disease with high morbidity and mortality. Diagnosis is often delayed, and disease tends to progress rapidly. Urgent surgical and medical intervention is lifesaving. Guidance on the complex multidisciplinary management has potential to improve prognosis, but approaches differ between health-care settings. From January, 2018, authors from 33 countries in all United Nations regions analysed the published evidence on mucormycosis management and provided consensus recommendations addressing differences between the regions of the world as part of the "One World One Guideline" initiative of the European Confederation of Medical Mycology (ECMM). Diagnostic management does not differ greatly between world regions. Upon suspicion of mucormycosis appropriate imaging is strongly recommended to document extent of disease and is followed by strongly recommended surgical intervention. First-line treatment with high-dose liposomal amphotericin B is strongly recommended, while intravenous isavuconazole and intravenous or delayed release tablet posaconazole are recommended with moderate strength. Both triazoles are strongly recommended salvage treatments. Amphotericin B deoxycholate is recommended against, because of substantial toxicity, but may be the only option in resource limited settings. Management of mucormycosis depends on recognising disease patterns and on early diagnosis. Limited availability of contemporary treatments burdens patients in low and middle income settings. Areas of uncertainty were identified and future research directions specified.

Guideline for Preclinical Studies of Bone Infections in Large Animals Based on a Systematic Review of 316 Non-Rodent Models

BACKGROUND

In recent years, animal models of bone infections have been used with increased frequency in order to evaluate novel diagnostic and anti-infective technologies, like antibacterial coating of bone implants or local antibiotic carrier products. Therefore, it is highly relevant to evaluate the scientific quality of existing bone infection models.

METHODS

We conducted a systematic review of 316 studies of large non-rodent animal models of bone infection (254 rabbit, 16 pig, 23 dog, 11 goat, and 12 sheep) and extracted data on study design, methodological quality, and postmortem evaluation of infection with respect to reporting and quantification of pathology and microbiology.

RESULTS

The review demonstrated a substantial lack of study-design information, which hampers reproducibility and continuation of the established work. Furthermore, the methodological study quality was found to be low, as the definition of infection, randomization, power analysis, and blinding were only seldomly reported. The use of histology increased in recent years, but a semi-quantitative scoring of the lesions was often missing, i.e. no objective quantification of outcome. Most of the studies focused on whether the inoculated bacteria were present within the bone tissue post mortem or not. However, very often the bacterial burden was not quantified. In many of the models, different antimicrobial interventions were examined and, although antimicrobial effects were commonly described, a lack of complete sterile outcome was observed in many models. On the basis of the systematic review, we established a study template providing a guideline for the standard reporting of animal models of bone infections, including details related to the animal, pathogen, infected animal, and postmortem analysis that are of crucial importance for validation of results and reproducibility.

CONCLUSIONS

As the aim of many bone infection models is to examine the effect of an intervention, the guideline emphasizes the importance of objective quantification of outcome, e.g., blinded quantitative scoring of histological findings and quantification of bacterial burden within tissue and on inserted implants. Less than 5% of the analyzed studies adhered completely to the ideal form presented in the study template.

CLINICAL RELEVANCE

Anti-infective interventions must be tested in preclinical animal models before implementation in human patients, and optimal design and validation is essential for a high translational value.

Time-dependent Pathologic and Inflammatory Consequences of Various Blood Sampling Techniques in Mice

We compared 6 frequently used mouse blood-sampling methods (lateral tail incision; tail-tip amputation; sublingual, submandibular, and saphenous vein puncture; and retrobulbar sinus puncture during isoflurane anesthesia) with regard to induction of local and systemic inflammation, stomach contents, weight changes, and corticosterone levels at 6 h to 12 d after sampling. Local inflammation was assessed through histopathology and assessment of the expression of inflammation and tissue damage-related genes (S1008/9A, Cxcl2, Il1b, Nlrp3, Il6, and Il33) in sampled tissue. Systemic inflammation was assessed through quantification of plasma haptoglobin levels, measurement of blood Il1b expression, and evaluation of histopathologic changes in lung, kidney, liver, and spleen. Apart from slight, transient increases in plasma haptoglobin levels after lateral tail incision, retrobulbar sinus puncture, and saphenous vein puncture, no other signs of systemic inflammation were found. Mice subjected to retrobulbar sinus puncture, sublingual puncture, or isoflurane anesthesia only showed the highest plasma corticosterone concentrations. Retrobulbar sinus puncture had the largest effect on body weight loss. Retrobulbar sinus puncture, sublingual puncture, and submandibular puncture only showed minor and in, most cases, fastresolving inflammation. By contrast, blood sampling by lateral tail incision, tail-tip amputation, or saphenous vein puncture caused tissue damage and inflammation locally at the sampling site, which resolved more slowly compared with head-region sampling techniques, according to results from pathologic and gene expression assessments. Expression of S1008/9A, Cxcl2, Il1b, and Nlrp3 increased 10- to 1000-fold and did not return to baseline until day 6 after sampling or later and did not resolve after tail-tip amputation within the 12-d observation period. Increased expression of genes involved in inflammation and tissue repair correlated with histopathologic changes and may thus represent a quantitative supplement to histopathology. In conclusion, none of the tested methods for obtaining blood samples from mice is superior, according to simultaneous immunologic, histopathologic, and animal welfare-related parameters.

Genital Infiltrations of CD4+ and CD8+ T Lymphocytes, IgA+ and IgG+ Plasma Cells and Intra-Mucosal Lymphoid Follicles Associate With Protection Against Genital Chlamydia trachomatis Infection in Minipigs Intramuscularly Immunized With UV-Inactivated Bacteria Adjuvanted With CAF01

The development of a vaccine against genital chlamydia in women is advancing, and the evaluation of in situ immune responses following vaccination and challenge infections is crucial for development of a safe and protective vaccine. This study employs the sexually mature minipig model to characterize the genital in situ immune response to Chlamydia trachomatis infection in pigs previously immunized intramuscularly with UV-inactivated C. trachomatis serovar D (UV-SvD) adjuvanted/formulated with CAF01 adjuvant compared to a CAF01-alone control group. Pigs immunized with UV-SvD were significantly protected against vaginal challenge with C. trachomatis on day 3 post inoculation and showed significantly higher cervical infiltrations of approximately equal numbers of CD4⁺ and CD8⁺ T-cells, and IgG⁺ and IgA⁺ plasma cells compared to adjuvant-alone immunized controls. These immunological signatures correspond to findings in mice and are similar to those described in female chlamydia patients. This proves important potential for the pig model in elucidating immunological in situ signatures in future translational research in chlamydia vaccinology.

Inhibitors of the renin-angiotensin system ameliorates clinical and pathological aspects of experimentally induced nephrotoxic serum nephritis

Introduction: Chronic kidney disease (CKD) is a global health concern, but the current treatments only slow down the progression. Thus an improved understanding of the pathogenesis and novel treatments of CKD are needed. The nephrotoxic nephritis (NTN) model has the potential to study the pathogenesis of CKD as it resembles human CKD. The classical treatments with angiotensin II receptor blocker (ARB) or the angiotensin-converting enzyme inhibitor (ACE I) have shown a clinical effect in CKD.

Methods: We characterized the disease development in the NTN model over 11 weeks by investigating functional and histopathological changes. We tested doses of 15 and 30 mg/kg/day enalapril and losartan in the NTN model in order to investigate the effect of inhibiting the renin-angiotensin-system (RAS).

Results: The NTN model displayed albuminuria peaking on days 6–7, mesangial expansion (ME), renal fibrosis, inflammation and iron accumulation peaking on day 42. However, albuminuria, ME, renal fibrosis and inflammation were still significantly present on day 77, suggesting that the NTN model is useful for studying both the acute and chronic disease phases. Enalapril and losartan significantly enhanced the glomerular filtration rate (GFR) and decreased albuminuria, ME, renal fibrosis and inflammation of NTN-induced kidney disease in mice.

Conclusions: This is the first study showing a comprehensive pathological description of the chronic features of the murine NTN model and that inhibiting the RAS pathway show a significant effect on functional and morphological parameters.

Temporal Regulation of Glomerular and Cortical Tubulointerstitial Genes Involved in the Development of Nephrotoxic Serum Nephritis

BACKGROUND/AIMS

Murine nephrotoxic nephritis (NTN) is a well-established model resembling chronic kidney disease. Investigating gene expression patterns separately in the glomerular and cortical tubulointerstitial structure could provide new knowledge about structure-specific changes in expression of genes in the NTN model.

METHODS

Glomerular, cortical tubulointerstitial and whole kidney tissues from mice subjected to nephrotoxic serum (NTS) or phosphate buffered saline (PBS) were collected on day 7, 21 and 42 using laser microdissection (LMD). Total RNA was extracted and subjected to nCounter NanoString. Histology, immunohistochemistry, in situ hybridization and/or quantitative real time PCR (qRT PCR) were performed to confirm regulation of selected genes.

RESULTS

LMD provided detailed information about genes that were regulated differently between structures over time. Some of the fibrotic and inflammatory genes (Col1a1, Col3a1 and Ccl2) were upregulated in both structures, whereas other genes such as Spp1 and Grem1 were differentially regulated suggesting spatial pathogenic mechanisms in the kidney. Downregulation of cortical tubulointerstitium genes involved in iron metabolism was detected along with iron accumulation.

CONCLUSION

This study demonstrates several regulated genes in pathways important for the pathogenesis of the NTN model and that LMD identifies structure-specific changes in gene expression during disease development. Furthermore, this study shows the benefits of isolating glomeruli and cortical tubulointerstitium in order to identify gene regulation.

Guidelines for porcine models of human bacterial infections

During the last 10 years the number of porcine models for human bacterial infectious diseases has increased. In the future, this tendency is expected to continue and, therefore, the aim of the present review is to describe guidelines for the development and reporting of these models. The guidelines are based on a review of 122 publications of porcine models for different bacterial infectious diseases in humans. The review demonstrates a substantial lack of information in most papers which hampers reproducibility and continuation of the work that was established in the models. The guidelines describe overall principles related to the inoculum, the animal, the infected animal and the post-mortem characterization that are of crucial importance when porcine models of infectious diseases are developed, validated and reported.

Porcine Models of Biofilm Infections with Focus on Pathomorphology

Bacterial biofilm formation is one of the main reasons for a negative treatment outcome and a high recurrence rate for many chronic infections in humans. The optimal way to study both the biofilm forming bacteria and the host response simultaneously is by using discriminative, reliable, and reproducible animal models of the infections. In this review, the advantages of in vivo studies are compared to in vitro studies of biofilm formation in infectious diseases. The pig is the animal of choice when developing and applying large animal models of infectious diseases due to its similarity of anatomy, physiology, and immune system to humans. Furthermore, conventional pigs spontaneously develop many of the same chronic bacterial infections as seen in humans. Therefore, in this review porcine models of five different infectious diseases all associated with biofilm formation and chronicity in humans are described. The infectious diseases are: chronic wounds, endocarditis, pyelonephritis, hematogenous osteomyelitis, and implant-associated osteomyelitis (IAO).

Genital tract lesions in sexually mature Göttingen minipigs during the initial stages of experimental vaginal infection with Chlamydia trachomatis serovar D

Background

Chlamydia is one of the most common sexually transmitted diseases in humans worldwide, causing chronic lesions in the reproductive tract. Due to its often asymptomatic course, there is limited knowledge about the initial changes in the genital tract following infection. This study employs a novel sexually mature minipig model to investigate the initial histopathological changes following vaginal infection with Chlamydia trachomatis serovar D.

Results

A vaginal inoculation resulted in an infection primarily affecting the lower genital tract. The histopathological changes were characterized by a subepithelial inflammation consisting of neutrophils and mononuclear cells, followed by an increase in the number of plasma cells within the sub-epithelial stroma of the vagina. Detection of Chlamydia was associated with expression of cyclooxygenase-2 and interleukin-8 by superficial epithelial cells. The infection was self-limiting, with a duration of 7 days.

Conclusion

Neutrophils, plasma cells and IL-8 have been linked with Chlamydia genital infection of unknown duration in human patients. In this study, we observe a similar pattern of local immune response/inflammation following experimental inoculation suggesting this porcine model shows promise as a model for translational chlamydia research.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-016-0793-6) contains supplementary material, which is available to authorized users.

Modelling severe Staphylococcus aureus sepsis in conscious pigs: are implications for animal welfare justified?

BACKGROUND

A porcine model of haematogenous Staphylococcus aureus sepsis has previously been established in our research group. In these studies, pigs developed severe sepsis including liver dysfunction during a 48 h study period. As pigs were awake during the study, animal welfare was challenged by the severity of induced disease, which in some cases necessitated humane euthanasia. A pilot study was therefore performed in order to establish the sufficient inoculum concentration and application protocol needed to produce signs of liver dysfunction within limits of our pre-defined humane endpoints.

METHODS

Four pigs received 1 × 10(8) cfu/kg BW of S. aureus, and two controls were sham inoculated with saline. A fixed infusion rate of 3 mL/min was used, while the inoculum concentration, i.e., the dose volume, was changed between the pigs. The following dose volumes were used: 10 mL (n = 1), 20 mL (n = 2), and 30 mL (n = 1), corresponding to infusion durations of 3.33, 6.66, and 10 min at dose rates of 3 × 10(7), 1.5 × 10(7), and 1 × 10(7) cfu/min/kg BW, respectively. Blood samples were drawn for complete blood count, clinical chemistry, and inflammatory markers before and every 6 h after inoculation. Prior to euthanasia, a galactose elimination capacity test was performed to assess liver function. Pigs were euthanised 48 h post inoculation for necropsy and histopathological evaluation.

RESULTS

While infusion times of 6.66 min, and higher, did not induce liver dysfunction (n = 3), the infusion time of 3.33 min (n = 1) caused alterations in parameters similar to what had been seen in our previous studies, i.e., increasing bilirubin and aspartate aminotransferase, as well as histopathological occurrence of intravascular fibrin split products in the liver. This pig was however euthanised after 30 h, according to humane endpoints.

CONCLUSIONS

A usable balance between scientific purpose and animal welfare could not be achieved, and we therefore find it hard to justify further use of this conscious porcine sepsis model. In order to make a model of translational relevance for human sepsis, we suggest that future model versions should use long-term anaesthesia.

Diet-induced dyslipidemia leads to nonalcoholic fatty liver disease and oxidative stress in guinea pigs

Chronic dyslipidemia imposed by a high-fat and high-caloric dietary regime leads to debilitating disorders such as obesity, nonalcoholic fatty liver disease (NAFLD), and insulin resistance. As disease rates surge, so does the need for high validity animal models to effectively study the causal relationship between diet and disease progression. The dyslipidemic guinea pig displays a high similarity with the human lipoprotein profile and may in this aspect be superior to other rodent models. This study investigated the effects of 2 long-term Westernized diets (0.35% cholesterol, 18.5% vegetable oil and either 15% or 20% sucrose) compared with isocaloric standard chow in adult guinea pigs. Biochemical markers confirmed dyslipidemia in agreement with dietary regimens; however, both high-fat groups displayed a decreased tissue fat percentage compared with controls. Macroscopic appearance, histopathologic evaluation, and plasma markers of liver function confirmed NAFLD in high-fat groups, supported by liver redox imbalance and markers suggesting hepatic endothelial dysfunction. Plasma markers indicated endothelial dysfunction in response to a high-fat diet, although atherosclerotic lesions were not evident. Evaluation of glucose tolerance showed no indication of insulin resistance. The 5% increase in sucrose between the 2 high-fat diets did not lead to significant differences between groups. In conclusion, we find the dyslipidemic guinea pig to be a valid model of diet imposed dyslipidemia, particularly with regards to hepatic steatosis and endothelial dysfunction. Furthermore, the absence of obesity supports the present study setup as targeting NAFLD in nonobese individuals.

Colonic Lesions, Cytokine Profiles, and Gut Microbiota in Plasminogen-Deficient Mice

Plasminogen-deficient (FVB/NPan-plg(tm1Jld), plg(tm1Jld)) mice, which are widely used as a wound-healing model, are prone to spontaneous rectal prolapses. The aims of this study were 1) to evaluate the fecal microbiome of plg(tm1Jld) mice for features that might contribute to the development of rectal prolapses and colonic inflammation and 2) to assess the relevance of the inflammatory phenotype to the variability in wound healing in this model. The (plgtm1Jld) mice exhibited delayed wound healing, and they could be divided into 3 distinct groups that differed according to the time until wound closure. Colonic lesions in plg(tm1Jld) mice, which were characterized by necrotizing ulcerations and cystically dilated glands, were restricted to the intermediate and distal parts of the colon. The cytokine profile was indicative of chronic tissue damage, but the genetic modification did not change the composition of the gut microbiota, and none of the clinical or biochemical parameters correlated with the gut microbiota composition.

Foot Lesions in Farmed Mink (Neovison vison): Pathologic and Epidemiologic Characteristics on 4 Danish Farms

The aim of this study was to evaluate gross and histologic lesions and epidemiologic factors of foot lesions in farmed mink. The feet of 1159 mink from 4 Danish farms were examined and lesions described. Swabs from the lesions were taken from 27 mink for microbiology, and tissue samples from a representative spectrum of feet with and without lesions (n= 22) were examined histologically. Feet were grouped according to gross inspection: no lesions (55.1%), hair loss (7.1%), hyperkeratosis (35.8%), and crusting (5.3%). Lesions were predominantly located in plantar metatarsal skin (98.1%). Staphylococci were the most prevalent microorganisms cultured from the lesions. There was a significant association between presence of lesions and sex (P< .0001), age (P< .0001), and color type (P= .023). Lesion size was significantly different between hair loss and crusts and between hyperkeratosis and crusts (P< .0001). Histologically, lesions included varying degrees of orthokeratotic to parakeratotic hyperkeratosis and granulomatous to pyogranulomatous dermatitis with trichogranulomas as a dominant feature in all mink. The gross and microscopic lesions were comparable to physically induced changes in other species that develop as a response to repetitive friction or pressure. The condition may have an impact on animal welfare in mink production.

A hereditary disposition for bovine peripheral nerve sheath tumors in Danish Holstein cattle

Background

Peripheral nerve sheath tumors (PNSTs) are frequently found in Danish cattle at slaughter. Bovine PNSTs share several gross and histopathological characteristics with the PNSTs in humans with heritable neurofibromatosis syndromes. The aim of the present study was to investigate a possible hereditary disposition to PNSTs in dairy cattle by statistical analysis performed on data from 567 cattle with PNSTs. Furthermore, a preliminary genome-wide association study (GWAS) was performed on DNA isolated from 28 affected and 28 non-affected Holstein cows to identify loci in the bovine genome involved in the development of PNSTs.

Results

PNSTs were significantly more common in the Danish Holstein breed than in other breeds with 0.49% of Danish Holsteins slaughtered during an eight-year-period having PNSTs. PNSTs also occurred significantly more frequently in the offspring of some specific Holstein sires. Examination of three generation pedigrees showed that these sires were genetically related through a widely used US Holstein sire. The PNSTs included in GWAS were histologically classified as neurofibroma-schwannoma (43%), schwannoma (36%) and neurofibroma (21%) and derived from Holstein cows with multiple PNSTs. A single SNP on chromosome 27 reached genome-wide significance.

Conclusions

Gross and histological characteristics of bovine PNSTs are comparable to PNSTs in humans (schwannomatosis). Danish Holsteins are genetically disposed to develop PNSTs but the examined materials are insufficient to allow determination of the mode of inheritance.

The distribution pattern of Halicephalobus gingivalis in a horse is suggestive of a haematogenous spread of the nematode

The majority of Halicephalobus gingivalis-infections in horses have been fatal and are usually not diagnosed before necropsy. Therefore, knowledge about the nematode and the pathogenesis of infection in horses is limited. This has resulted in an on-going discussion about the port of entry and subsequent dissemination of H. gingivalis within the host. The present case of H. gingivalis-infection in a horse was diagnosed ante mortem. Post mortem findings, the distribution pattern of H. gingivalis nematodes in the brain, a high prevalence of inflammation in close relation to blood vessels, and the presence of the nematode in multiple organs with a disseminated pattern of distribution strongly suggested a haematogenous spread of the nematode in the horse.

Grading of shoulder ulcerations in sows by biopsies

Shoulder ulcerations can be graded postmortem from 0 to 4 on a pathoanatomical scale. However, veterinarians and farmers express difficulties evaluating the grade of the lesions antemortem. Accurate grading is needed in order to comply with veterinary instruction in relation to the Danish legislation, stating that sows with shoulder ulcers grade 3 or 4 must be kept loose and have access to soft bedding. Thus, the aim of the present study was to evaluate if biopsies from the center of a shoulder ulcer can be used to point out animals for which an intervention must be initiated. Postmortem, a punch biopsy was sampled from the center of the ulceration or from the tissue overlaying the tuber spina scapula. Afterward, the shoulders were cross-sectioned and evaluated grossly and histologically ("gold standard"). In total, 121 shoulders were included in the study, and the diagnostic value of a punch biopsy in grading shoulder ulcerations was evaluated. The results showed a sensitivity of 0.78, a specificity of 0.98, a positive likelihood ratio of 38.36, and a negative likelihood ratio of 0.22. The agreement between the cross-section evaluation and the punch biopsy was found to be 0.90 by calculating the Cohen kappa value. In conclusion, a single punch biopsy from the center of an ulcer is useful for determining the grade of a shoulder ulcer and can be used to facilitate the identification of sows with ulcers requiring an intervention.

Immunohistochemical detection of interleukin-8 in inflamed porcine tissues

The objective of this study was to identify the specific localization of interleukin-8 (IL-8) in cells in situ in a variety of inflammatory processes in different tissues from pigs. Our hypothesis was that IL-8 primarily is a neutrophil related cytokine present in all extravascular neutrophils while expression also occurs in other cell types in response to an inflammatory stimulus. Using IL-8 immunohistochemistry we discovered that neutrophils were the predominant IL-8 positive cell population while epithelial cell types and endothelium of postcapillary venules could be positive when situated in close vicinity of an inflammatory lesion. Furthermore, endothelial cells of newly formed vessels in granulation tissue were positive in some specimens. Some sub-populations of inflammatory neutrophils were, however, IL-8 negative which could reflect some phase of neutrophil swarming.

Brain microabscesses in a porcine model of Staphylococcus aureus sepsis

BACKGROUND

Sepsis caused by Staphylococcus aureus often leads to brain microabscesses in humans. Animal models of haematogenous brain abscesses would be useful to study this condition in detail. Recently, we developed a model of S. aureus sepsis in pigs and here we report that brain microabscesses develop in pigs with such induced S. aureus sepsis.Twelve pigs were divided into three groups. Nine pigs received an intravenous inoculation of S. aureus once at time 0 h (group 1) or twice at time 0 h and 12 h (groups 2 and 3). In each group the fourth pig served as control. The pigs were euthanized at time 12 h (Group 1), 24 h (Group 2) and 48 h (Group 3) after the first inoculation. The brains were collected and examined histopathologically.

RESULTS

All inoculated pigs developed sepsis and seven out of nine pigs developed brain microabscesses. The microabscesses contained S. aureus and were located in the prosencephalon and mesencephalon. Chorioditis and meningitis occurred from 12 h after inoculation.

CONCLUSIONS

Pigs with experimental S. aureus sepsis often develop brain microabscesses. The porcine brain pathology mirrors the findings in human sepsis patients. We therefore suggest the pig as a useful animal model of the development of brain microabscesses caused by S. aureus sepsis.

Organization and biology of the porcine serum amyloid A (SAA) gene cluster: isoform specific responses to bacterial infection

Serum amyloid A (SAA) is a prominent acute phase protein. Although its biological functions are debated, the wide species distribution of highly homologous SAA proteins and their uniform behavior in response to injury or inflammation in itself suggests a significant role for this protein. The pig is increasingly being used as a model for the study of inflammatory reactions, yet only little is known about how specific SAA genes are regulated in the pig during acute phase responses and other responses induced by pro-inflammatory host mediators. We designed SAA gene specific primers and quantified the gene expression of porcine SAA1, SAA2, SAA3, and SAA4 by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) in liver, spleen, and lung tissue from pigs experimentally infected with the Gram-negative swine specific bacterium Actinobacillus pleuropneumoniae, as well as from pigs experimentally infected with the Gram-positive bacterium Staphylococcus aureus. Our results show that: 1) SAA1 may be a pseudogene in pigs; 2) we were able to detect two previously uncharacterized SAA transcripts, namely SAA2 and SAA4, of which the SAA2 transcript is primarily induced in the liver during acute infection and presumably contributes to circulating SAA in pigs; 3) Porcine SAA3 transcription is induced both hepatically and extrahepatically during acute infection, and may be correlated to local organ affection; 4) Hepatic transcription of SAA4 is markedly induced in pigs infected with A. pleuropneumoniae, but only weakly in pigs infected with S. aureus. These results for the first time establish the infection response patterns of the four porcine SAA genes which will be of importance for the use of the pig as a model for human inflammatory responses, e.g. within sepsis, cancer, and obesity research.

Systemic inflammatory response and local cytokine expression in porcine models of endocarditis

The knowledge of systemic inflammation and local cytokine expression in porcine endocarditis models is limited, though it could provide valuable information about the pathogenesis and comparability to human endocarditis. Analyses of bacteriology and hematology were performed on blood samples from pigs with non-bacterial thrombotic endocarditis (NBTE, n = 11), Staphylococcus aureus infective endocarditis (IE, n = 2), animals with S. aureus sepsis without endocarditis (n = 2) and controls (n = 2). Furthermore, immunohistochemistry was used to examine the local expression of IL-1β and IL-8. Bacterial blood cultures were continuously positive in IE pigs from inoculation to euthanasia, and negative in all other pigs at all times. The total white blood cell counts and total neutrophil counts were massively elevated in pigs with IE. Local IL-1β and IL-8 expression in IE pigs were moderate to high, and high, respectively. In addition, slight local expression of IL-1β and IL-8 was present in some NBTE pigs. In the IE model, both the systemic inflammatory response and the high local expression of IL-8 were comparable to the human disease. Furthermore, the results indicate IL-1β and IL-8 as important contributors in the endocarditis pathogenesis.

Disseminated intravascular coagulation in a novel porcine model of severe Staphylococcus aureus sepsis fulfills human clinical criteria

Sepsis is a common and often fatal complication in human patients in intensive care units. Relevant and well characterized animal models of sepsis may provide valuable information on pathophysiological mechanisms and be a mean of testing new therapeutic strategies. Large animal models of Staphylococcus aureus sepsis are rare, even though S. aureus increasingly affects human patients. Sepsis changes the haemostatic balance and leads to endothelial cell (EC) activation, coagulopathy and, in severe cases, disseminated intravascular coagulation (DIC). The aim of this study was to characterize the haemostatic and vascular alterations in a novel porcine model of severe S. aureus sepsis, investigating whether the changes fulfill the human clinical criteria for DIC. Five pigs were inoculated intravenously with S. aureus and two control animals were sham-inoculated. Blood samples were collected for thromboelastography (TEG) and assessment of plasma-based haemostatic parameters. Tissue was collected for histopathology and reverse transcriptase quantitative real-time polymerase chain reaction for measurement of mRNA encoding EC markers. All infected animals developed DIC; including procoagulant activation represented by hypercoagulable TEG profiles and prolonged clotting time. Histologically, numerous pulmonary thrombi were present in one pig. Inhibitor consumption was represented by decreasing antithrombin levels in infected pigs. Hyaline globules were found in three infected pigs, confirming fibrinolytic activation. EC activation was identified by expression of von Willebrand factor in small vessels together with elevated mRNA encoding activated EC markers. Severe haemostatic and vascular changes fulfilling the human criteria for DIC were therefore seen in all infected pigs. A tendency towards uncompensated DIC was seen in two animals.

Immunohistochemical study of porcine lung lesions associated with Pasteurella multocida

Infectious bronchopneumonia is a widespread disease in modern commercial pig production and Pasteurella multocida is frequently associated with the lesions. To evaluate porcine lung lesions associated with P. multocida, populations of inflammatory cells were examined by immunohistochemistry in necrotic lung lesions from nine pigs and exudative lung lesions from eleven pigs. Lungs from five pigs served as controls. All cases were selected from naturally infected pigs using co-infection based criteria to make them as comparable as possible. The inflammatory cells demonstrated by immunohistochemistry were T-lymphocytes (CD3⁺, CD4⁺ and CD8⁺ subsets), B-lymphocytes, neutrophils, macrophages, and IgA⁺, IgM⁺ and IgG⁺ cells.

The results showed that (1) a significant increase in all inflammatory cells was found in lesions associated with P. multocida, (2) necrotic lesions had a larger number of CD3⁺ T-lymphocytes and IgA⁺ cells, and (3) cases with exudative lesions had a more CD8⁺ T-lymphocytes, B-lymphocytes, macrophages and neutrophils. No differences in the numbers of CD4⁺ T-lymphocytes, IgG⁺ and IgM⁺ positive cells were found between necrotic and exudative cases. The results show that P. multocida significantly alters the inflammatory response in the lung and that lesions associated with P. multocida display diverse inflammatory responses according to their distinct morphological pattern.

Therapy of haematogenous osteomyelitis--a comparative study in a porcine model and Angolan children

BACKGROUND

It is generally accepted that surgery is necessary for the proper treatment of chronic haematogenous osteomyelitis (HO) in children. However, the correct timing of surgery and the technique most effective for debridement of infectious bone tissue is debated. Theoretically, large animal models of HO can be used for refinement and testing of surgical protocols. We report, to our knowledge for the first time, a porcine model of HO exposed to surgical treatment together with our surgical experiences with Angolan children suffering from chronic HO.

MATERIALS AND METHODS

Surgically-debrided bone tissue from the children and pigs were analyzed microbiologically and histopathologically together with the entire operated bones from the pigs.

RESULTS

It was illustrated that surgical intervention on porcine bones with experimentally-induced HO is representative of the handling of the condition in children. The porcine HO model can easily be used for refinement and application of surgical techniques used in order to cure children with HO.

Porcine models of non-bacterial thrombotic endocarditis (NBTE) and infective endocarditis (IE) caused by Staphylococcus aureus: a preliminary study

BACKGROUND AND AIM OF THE STUDY

Non-bacterial thrombotic endocarditis (NBTE) and, in particular, infective endocarditis (IE), are serious and potentially life-threatening diseases. An increasingly important agent of human IE is Staphylococcus aureus, which typically causes an acute endocarditis with high mortality. The study aim was to evaluate the pig as a model for non-bacterial as well as S. aureus-associated endocarditis, as these models would have several advantages compared to other laboratory animal models.

METHODS

Fourteen animals underwent surgery with placement of a plastic catheter in the left side of the heart. Six of the pigs did not receive a bacterial inoculation and were used to study the development of NBTE. The remaining eight pigs were inoculated intravenously once or twice with S. aureus, 10(5)-10(7) cfu/kg body weight. Two bacterial strains were used: S54F9 (porcine) and NCTC8325-4 (human). Clinical examination, echocardiography and bacterial blood cultures were used to diagnose and monitor the development of endocarditis. Animals were euthanized at between two and 15 days after catheter placement, and tissue samples were collected for bacteriology and histopathology.

RESULTS

Pigs inoculated with 10(7) cfu/kg of S. aureus strain S54F9 developed clinical, echocardiographic and pathologic signs of IE. All other pigs, except one, developed NBTE. Serial blood cultures withdrawn after inoculation were positive in animals with IE, and negative in all other animals.

CONCLUSION

S. aureus endocarditis was successfully induced in pigs with an indwelling cardiac catheter after intravenous inoculation of 10(7) cfu/kg of S. aureus strain S54F9. The model simulates typical pathological, clinical and diagnostic features seen in the human disease. Furthermore, NBTE was induced in all but one of the pigs without IE. Thus, the pig model can be used in future studies of the pathogenesis, diagnosis and therapy of NBTE and S. aureus endocarditis.

ESCMID* guideline for the diagnosis and management of Candida diseases 2012: patients with HIV infection or AIDS

Mucosal candidiasis is frequent in immunocompromised HIV-infected highly active antiretroviral (HAART) naive patients or those who have failed therapy. Mucosal candidiasis is a marker of progressive immune deficiency. Because of the frequently marked and prompt immune reconstitution induced by HAART, there is no recommendation for primary antifungal prophylaxis of mucosal candidiasis in the HIV setting in Europe, although it has been evidenced as effective in the pre-HAART era. Fluconazole remains the first line of therapy for both oropharyngeal candidiasis and oesophageal candidiasis and should be preferred to itraconazole oral solution (or capsules when not available) due to fewer side effects. For patients who still present with fluconazole-refractory mucosal candidiasis, oral treatment with any other azole should be preferred based on precise Candida species identification and susceptibility testing results in addition to the optimization of HAART when feasible. For vaginal candidiasis, topical therapy is preferred.

ESCMID* guideline for the diagnosis and management of Candida diseases 2012: adults with haematological malignancies and after haematopoietic stem cell transplantation (HCT)

Fungal diseases still play a major role in morbidity and mortality in patients with haematological malignancies, including those undergoing haematopoietic stem cell transplantation. Although Aspergillus and other filamentous fungal diseases remain a major concern, Candida infections are still a major cause of mortality. This part of the ESCMID guidelines focuses on this patient population and reviews pertaining to prophylaxis, empirical/pre-emptive and targeted therapy of Candida diseases. Anti-Candida prophylaxis is only recommended for patients receiving allogeneic stem cell transplantation. The authors recognize that the recommendations would have most likely been different if the purpose would have been prevention of all fungal infections (e.g. aspergillosis). In targeted treatment of candidaemia, recommendations for treatment are available for all echinocandins, that is anidulafungin (AI), caspofungin (AI) and micafungin (AI), although a warning for resistance is expressed. Liposomal amphotericin B received a BI recommendation due to higher number of reported adverse events in the trials. Amphotericin B deoxycholate should not be used (DII); and fluconazole was rated CI because of a change in epidemiology in some areas in Europe. Removal of central venous catheters is recommended during candidaemia but if catheter retention is a clinical necessity, treatment with an echinocandin is an option (CII(t) ). In chronic disseminated candidiasis therapy, recommendations are liposomal amphotericin B for 8 weeks (AIII), fluconazole for >3 months or other azoles (BIII). Granulocyte transfusions are only an option in desperate cases of patients with Candida disease and neutropenia (CIII).

ESCMID* guideline for the diagnosis and management of Candida diseases 2012: non-neutropenic adult patients

This part of the EFISG guidelines focuses on non-neutropenic adult patients. Only a few of the numerous recommendations can be summarized in the abstract. Prophylactic usage of fluconazole is supported in patients with recent abdominal surgery and recurrent gastrointestinal perforations or anastomotic leakages. Candida isolation from respiratory secretions alone should never prompt treatment. For the targeted initial treatment of candidaemia, echinocandins are strongly recommended while liposomal amphotericin B and voriconazole are supported with moderate, and fluconazole with marginal strength. Treatment duration for candidaemia should be a minimum of 14 days after the end of candidaemia, which can be determined by one blood culture per day until negativity. Switching to oral treatment after 10 days of intravenous therapy has been safe in stable patients with susceptible Candida species. In candidaemia, removal of indwelling catheters is strongly recommended. If catheters cannot be removed, lipid-based amphotericin B or echinocandins should be preferred over azoles. Transoesophageal echocardiography and fundoscopy should be performed to detect organ involvement. Native valve endocarditis requires surgery within a week, while in prosthetic valve endocarditis, earlier surgery may be beneficial. The antifungal regimen of choice is liposomal amphotericin B +/- flucytosine. In ocular candidiasis, liposomal amphotericin B +/- flucytosine is recommended when the susceptibility of the isolate is unknown, and in susceptible isolates, fluconazole and voriconazole are alternatives. Amphotericin B deoxycholate is not recommended for any indication due to severe side effects.

ESCMID* guideline for the diagnosis and management of Candida diseases 2012: diagnostic procedures

As the mortality associated with invasive Candida infections remains high, it is important to make optimal use of available diagnostic tools to initiate antifungal therapy as early as possible and to select the most appropriate antifungal drug. A panel of experts of the European Fungal Infection Study Group (EFISG) of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) undertook a data review and compiled guidelines for the clinical utility and accuracy of different diagnostic tests and procedures for detection of Candida infections. Recommendations about the microbiological investigation and detection of candidaemia, invasive candidiasis, chronic disseminated candidiasis, and oropharyngeal, oesophageal, and vaginal candidiasis were included. In addition, remarks about antifungal susceptibility testing and therapeutic drug monitoring were made.