Order of exposure to high dietary calcium and gray strain infectious bronchitis virus alters renal function and the incidence of urolithiasis

Genomics and pathogenesis of the avian coronavirus infectious bronchitis virus

Infectious bronchitis virus (IBV) is a member of the family Coronaviridae, together with viruses such as SARS-CoV, MERS-CoV and SARS-CoV-2 (the causative agent of the COVID-19 global pandemic). In this family of viruses, interspecies transmission has been reported, so understanding their pathobiology could lead to a better understanding of the emergence of new serotypes. IBV possesses a single-stranded, non-segmented RNA genome about 27.6 kb in length that encodes several non-structural and structural proteins. Most functions of these proteins have been confirmed in IBV, but some other proposed functions have been based on research conducted on other members of the family Coronaviridae. IBV has variable tissue tropism depending on the strain, and can affect the respiratory, reproductive, or urinary tracts; however, IBV can also replicate in other organs. Additionally, the pathogenicity of IBV is also variable, with some strains causing only mild clinical signs, while infection with others results in high mortality rates in chickens. This paper extensively and comprehensibly reviews general aspects of coronaviruses and, more specifically, IBV, with emphasis on protein functions and pathogenesis. The pathogenicity of the Australian strains of IBV is also reviewed, describing the variability between the different groups of strains, from the classical to the novel and recombinant strains. Reverse genetic systems, cloning and cell culture growth techniques applicable to IBV are also reviewed.

Nanotherapeutics for treating coronavirus diseases

Viral diseases have recently become a threat to human health and rapidly become a significant cause of mortality with a continually exacerbated unfavorable socio-economic impact. Coronaviruses, including severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome (MERS-CoV), and severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), have threatened human life, with immense accompanying morbidity rates; the COVID-19 (caused by SARS-CoV-2) epidemic has become a severe threat to global public health. In addition, the design process of antiviral medications usually takes years before the treatments can be made readily available. Hence, it is necessary to invest scientifically and financially in a technology platform that can then be quickly repurposed on demand to be adequately positioned for this kind of pandemic situation through lessons learned from the previous pandemics. Nanomaterials/nanoformulations provide such platform technologies, and a proper investigation into their basic science and biological interactions would be of great benefit for potential vaccine and therapeutic development. In this respect, intelligent and advanced nano-based technologies provide specific physico-chemical properties, which can help fix the key issues related to the treatments of viral infections. This review aims to provide an overview of the latest research on the effective use of nanomaterials in the treatment of coronaviruses. Also raised are the problems, perspectives of antiviral nanoformulations, and the possibility of using nanomaterials effectively against current pandemic situations.

Avian Coronavirus: Case of Infectious Bronchitis Virus Pathogenesis, Diagnostic Approaches, and Phylogenetic Relationship Among Emerging Strains in Middle East and North Africa Regions

Infectious bronchitis (IB) virus (IBV) is a very dynamic and evolving virus, causing severe diseases in poultry with significant economic consequences to the poultry industry worldwide, affecting chickens of all ages and possessing a major threat to the poultry industry.

IBV is well studied worldwide; nevertheless, in Middle East and North Africa (MENA) regions, epidemiological and scientific data are poor and not updated. In spite of regular vaccination with Massachusetts (Mass) strain has been available to control IB for many decades in MENA regions, which it is most commonly used, the protection is not occurred. However, the continuity of the spread of IBV has shown the emergence of multiple variant strains due to the frequent point of mutations and recombination events in the S1 gene hypervariable regions.

All the reported IBV variants circulate in the form of several serotypes/genotypes that can be partially or poorly neutralized by current vaccines. This emergence remains a problem for the poultry industry and vaccine manufacturers. Therefore the objective of this present chapter, which is reported for the first time, aims to establish phylogenic relationship among emerging strains in MENA regions.

Current situation, genetic relationship and control measures of infectious bronchitis virus variants circulating in African regions

Infectious bronchitis virus (IBV) is a major viral pathogen of commercial poultry, affecting chickens of all ages and causing major economic losses in poultry industry worldwide. Frequent points of mutations and recombination events in the S1 gene region, result in the emergence of new IBVs variants circulating in the form of several serotypes/genotypes that can be partially or poorly neutralized by current vaccines. IBV is well studied worldwide, nevertheless in African countries epidemiological and scientific data are poor and not updated. This review aims to give a current overview of IBV situation, to establish evolutionary relationship between the African variants and to list some of the potential measures to control IBV in Africa. Three S1 gene hypervariable regions were studied and compared to the reference genotypes/serotypes that found emerging in African regions. This comparison was based on phylogenetic trees, nucleotide and amino-acid sequence analysis. It clearly appears that IBV variants reported in Africa, display a low genetic relationship between them and with the majority of the reference strains emerging in neighboring countries, except the case of variants from Libya and Egypt that show a high relatedness. Also the Massachusetts serotypes were the most prevalent co-circulating with both serotypes, Italy02 type in Morocco and Qx-like genotype in South part of the African continent. In order to control the IBV variants in African regions, an efficient vaccination strategy program should be implemented.

Assessment of pathogenicity and tissue distribution of infectious bronchitis virus strains (Italy 02 genotype) isolated from moroccan broiler chickens

Background

Avian infectious bronchitis (IB) is one of the most important viral diseases of poultry, affecting chickens of all ages and causing major economic losses in poultry flocks. Mass vaccination is conducted in Morocco using a vaccine against Massachusetts, which is the most dominant serotype; however no information about the pathogenesis and tissue distribution of the Moroccan Italy 02 genotype was reported.

40 one-day-old specific pathogen free chickens were divided randomly into four groups. Group1, 2 and 3 were inoculated intra oculo-nasally with 103.5 EID50 of Italy02 viruses, and group 4 was kept as control. Chickens in each group were monitored for 14 days post-infection (pi).

Results

Chickens in all infected groups showed severe respiratory signs, which most of them have been reproduced on 2dpi, with varying times of appearance and disappearance. The infected birds appeared lethargic, reluctant to move, with specific respiratory clinical signs and macroscopic lesions. However no nephritis lesions or mortality were recorded in all groups. The specific histological lesions finding in all infected birds, exhibited tracheal lesions with mucosal thickening, hyperplasia of the surface epithelium, mononuclear inflammatory cell infiltrate of lamina propria. Primary and secondary bronchi, epithelial hyperplasia and mononuclear inflammatory cell infiltrate of the lamina propria were also observed. Tracheal lesions developed in all infected birds, confirm the ability of the three tested strains to induce respiratory disease. The results at 14 dpi also revealed that all strains were able to induce serological response. Virus re-isolation from infected organs and amplification of the viral RNA by real-time PCR proved the presence of the virus in lung and trachea of infected chicks. Neither re-isolation nor significant viral RNA detection were detected in the kidney.

Conclusion

The results demonstrated that the three strains Italy02 genotype emerging in Moroccan poultry farms have a wide distribution for respiratory system, without kidney damage and without causing mortality.

Epididymal lithiasis in roosters: in the middle of the way there was a stone

The epididymal region plays an important role in the reproduction of roosters, as it is the site of functions important in the maintenance of fertility, including fluid and calcium reabsorption and sperm surface modifications. About 10 years ago, a reproductive dysfunction characterized by the formation of luminal calcium stones in the epididymal region of roosters was described. This anomaly, known as epididymal lithiasis, is associated with a significant decrease in the fertility of affected roosters. This reproductive anomaly has been observed in multiple countries and is thought to negatively impact the poultry industry; however, the cause of epididymal lithiasis has not been fully determined. Several hypotheses have been proposed to explain the origin of epididymal lithiasis, including the presence of an infectious agent within the epididymal region, an autoimmune response, increased dietary calcium and vitamin D3 intake and the presence of genetic susceptibility factors; however, none of these has been proven to be the primary cause of the calcium stone formation. Nonetheless, considerable evidence suggests that regardless of the primary cause of epididymal lithiasis, this anomaly could result from a hormonal imbalance or a local impairment of calcium homeostasis in the epididymal region. The objectives of this mini-review are to 1) summarize the reproductive alterations observed in animals affected by epididymal lithiasis, 2) discuss the hypotheses proposed to explain the cause of luminal stone formation and 3) provide perspectives for future studies of this reproductive disorder.

Nephropathogenic infectious bronchitis in Pennsylvania chickens 1997-2000

Nephropathogenic infectious bronchitis (NIB) was diagnosed in 28 infectious bronchitis virus (IBV)-vaccinated commercial chicken flocks in Pennsylvania from December 1997 to July 2000. Early dinical signs were increased flock mortality and urinary water loss (polyuria and pollakiuria) leading to wet litter. Daily mortality ranged from 0.01% in layers to 2.45% in broilers, with total broiler mortality as high as 23%. Severe renal swelling and accumulation of urates in the tubules were commonly seen. Visceral gout and urolithiasis were less frequently observed. Histopathologic changes included characteristic tubular epithelial degeneration and sloughing with lymphoplasmacytic interstitial nephritis. Minimal respiratory disease signs were noted in broilers. Egg production and shell quality declined in layers. Confirmatory diagnosis of NIB was made by IBV antigen-specific immunohistochemical staining of the renal tubular epithelium and virus isolation. Sequencing of the S1 subunit gene of 21 IBV isolates showed the NIB outbreak to be associated with two unique genotypes, PA/Wolgemuth/98 and PA/171/99. The cases from which the genotypes were isolated were clinically indistinguishable. The NIB viruses were unrelated to previously recognized endemic strains in Pennsylvania and were also dissimilar to each other. Genotype PA/Wolgemuth/98 was isolated almost exclusively during the first 14 mo of the outbreak, whereas PA/171/99 was recovered during the final 18 mo. The reason for the apparent replacement of PA/Wolgemuth/98 by PA/171/99 is not known.

Ureterotomy for removal of two ureteroliths in a parrot

A 21-year-old male double-yellowheaded Amazon parrot was referred because of possible urolithiasis. The bird had strained to void since it was young, and recently, signs of depression and inappetence had appeared. Radiography revealed 2 mineralized opacities in the left caudal portion of the celomic cavity. A left lateral celiotomy revealed that the left ureter was dilated and contained a calculus, which was later determined to be composed of monosodium uric acid crystals and proteinaceous material. The second mineralized mass could not be located at that time, but was detected in the caudal aspect of the celomic cavity after surgery by use of radiography. Manual attempts to maneuver the uterolith from the ureter through the cloaca were unsuccessful. Five days after the initial surgery, the uterolith was removed by cloacotomy and ventral midline laparotomy. Excretory urography performed 10 and 31 days after surgery revealed that the left ureter was homogeneously opacified and gradually decreased to 3 to 6 mm in diameter. The bird remained healthy and seemed to strain less severely during voiding. Nonspecific signs associated with ureteroliths may result in delay in diagnosis. Surgical removal of ureteroliths may be an effective treatment for this uncommon condition, but it is complicated by certain anatomic features of birds and may result in ureteral stricture.

Effect of nephropathogenic infectious bronchitis viruses on renal function in young male broiler chickens

1. The acute effects of challenge with Australian T-strain infectious bronchitis virus (IBV) on renal function were evaluated, following primary vaccination in 1-d-old male broilers. 2. Challenge with T-strain IBV decreased body weight and induced kidney hypertrophy and kidney asymmetry. 3. Haematocrit was reduced in birds challenged with the Australian T-strain IBV and plasma uric acid was elevated in unvaccinated birds exposed to the IBV challenge. 4. Challenge with T-strain IBV caused significant increases in urinary water losses, accompanied by decreased urine osmolality and increased fractional excretion of sodium, calcium and potassium. 5. Vaccination at 1-d-old with Vic S-strain IBV provided a limited degree of protection against an heterologous challenge with T-strain IBV at 15 d of age.

Comparative pathology of a chicken-origin and two duck-origin influenza virus isolates in chickens: the effect of route of inoculation

Forty-nine 5-week-old chickens were inoculated by the intravenous (i.v.), intratracheal (IT), or intranasal (IN) routes with either a chicken-origin or one of two duck-origin type A influenza virus isolates. Twelve control chickens were inoculated with sterile chorioallantoic fluid. For all viruses, i.v. inoculation produced predominate lesions of renal tubule necrosis (nephrosis) and nephritis, and influenza virus nucleoprotein was localized in nuclei and cytoplasm of necrotic renal tubule epithelium. Chickens inoculated by the IT route, and to a lesser extent the IN route, had mild to severe tracheitis, bronchitis, and ventromedial pneumonia associated with secondary bronchi but lacked renal tubule necrosis and nephritis. These data indicate low-virulence avian-origin influenza viruses were nephrotropic during simulated systemic infection (i.v. inoculation) and pneumotropic during simulated local infection (IT and IN inoculation). Gross and histologic kidney lesions produced by i.v. inoculation of the chicken-origin influenza virus were similar to changes reported in outbreaks of low-virulence influenza virus in laying chickens.

Hypercalciuric response to dietary supplementation with DL-methionine and ammonium sulfate

Renal Ca and inorganic P (Pi) excretion were evaluated in Single Comb White Leghorn pullets reared on diets containing 1 or 3.5% Ca alone or supplemented with .6% DL-methionine or .53% ammonium sulfate. Plasma and urine samples were collected during a CONTROL period, and while 200 mM Ca was infused intravenously (Ca-LOADING). Excess Ca, whether supplied chronically in the feed or infused acutely into birds fed 1% Ca diets, significantly reduced glomerular filtration rates, effective renal plasma flow rates, and Pi excretion rates and significantly increased Ca excretion rates and urine pH. Birds fed diets supplemented with DL-methionine and ammonium sulfate maintained significantly lower plasma Ca concentrations during the CONTROL and Ca-LOADING periods than birds fed the respective 1 or 3.5% Ca basal diets. When compared with birds fed the respective 1 or 3.5% Ca basal diets, birds fed the 1% Ca diet supplemented with ammonium sulfate or the 3.5% Ca diet supplemented with DL-methionine had significantly higher absolute urinary Ca excretion rates during Ca-LOADING. Fractional Ca excretion during Ca-LOADING was significantly higher in birds fed 3.5% Ca supplemented with DL-methionine or ammonium sulfate than in birds fed the 3.5% Ca basal diet. These results indicate that DL-methionine and ammonium sulfate accelerated urinary Ca excretion and reduced Ca retention in the extracellular fluid. The hypercalciuric efficacies of DL-methionine and ammonium sulfate were revealed only when the filtered load of Ca was increased through intravenous Ca infusions.

Susceptibility of two commercial single comb White Leghorn strains to calcium-induced urolithiasis: efficacy of dietary supplementation with DL-methionine and ammonium sulphate

1. Susceptibility to calcium-induced urolithiasis was assessed in pullets of two commercial SCWL strains (A and B) reared together from 5 to 18 weeks of age on diets containing 10 g/kg calcium (normal calcium: NC) or 35 g/kg calcium (high calcium: HC). 2. Kidney damage was not observed in pullets reared on NC diets. For pullets fed on HC diets, strain A developed significantly greater kidney asymmetry, a higher incidence of gross kidney damage and a higher incidence of uroliths than strain B. 3. Supplementing the HC diet with 6 g/kg DL-methionine significantly reduced the incidence of calcium-induced gross kidney damage and urolith formation in both strains. Ammonium sulphate (5.3 g/kg) was significantly more effective than DL-methionine in reducing calcium-induced kidney damage. 4. Neither DL-methionine nor ammonium sulphate caused a measurable metabolic acidosis. Neither supplement consistently affected water consumption or manure moisture.

Liquid methionine hydroxy analog (free acid) and DL-methionine attenuate calcium-induced kidney damage in domestic fowl

To evaluate the possibility that kidney damage may be induced by the commercial practice of feeding high-Ca (HCa) prelayer rations, and to evaluate the protective efficacy of supplementing HCa diets with liquid methionine hydroxy analog free acid or DL-methionine, 12-wk-old female Single Comb White Leghorn pullets were fed one of the following corn-soybean meal-based diets until they reached 22 wk of age: normal-Ca (NC, 1% Ca); HCa (HC, 3.5% Ca); HCa supplemented with .34 or .68% liquid methionine hydroxy analog free acid (HC3A or HC6A); or HCa supplemented with .3 or .6% DL-methionine (HC3DL or HC6DL). The unsupplemented HC diet caused a significant reduction in kidney mass and a significant increase in the incidence of gross kidney damage and urolithiasis in pullets necropsied at 22 wk of age. Calcium-induced kidney damage was attenuated in a dose-response fashion by supplementing the HC diet with liquid methionine hydroxy analog and DL-methionine. None of the diets caused a significant metabolic acidosis. Plasma uric acid concentrations were not predictive of the extent of Ca-induced kidney damage. Analyses of glomerular size distributions indicated that subclinical or "hidden" kidney damage may not progressively develop into urolithiasis as hens mature. When compared with hens reared on the NC diet, rearing hens on the HC, HC3A, HC3DL, HC6A, or HC6DL diets did not consistently affect hen-day egg production, egg mass, eggshell mass, percentage eggshell, or bone mineralization.

Excess sodium bicarbonate in the diet and its effect on Leghorn chickens

1. A commercial 62-week-old layer flock experienced an acute drop in egg production and an increase in shell-less egg production within 2 days of consuming feed erroneously formulated to contain over 30 g/kg instead of 3 g/kg sodium bicarbonate (NaHCO3). Other symptoms included increased water consumption, diarrhoea and increased mortality associated with visceral gout. 2. An experiment was conducted to assess the responses of hens under controlled conditions. Twenty Dekalb XL Single Comb White Leghorn hens (50 weeks old) were placed in individual cages, having ad libitum access to water from trough waterers. Ten hens were fed the TEST (High NaHCO3) feed for one week (Test group), and ten hens remained on normal commercial layer ration (Control group). 3. Hens in the Test group had high water consumption and watery droppings, but egg production and mortality were not affected. Physiological evaluations indicated the Test feed caused metabolic alkalosis. Plasma sodium, urine pH and urinary sodium excretion were increased, and glomerular filtration rates were decreased in the Test group. 4. These physiological effects are consistent with known responses to excess sodium intake in domestic fowl. The reduced egg production and increased mortality caused by the Test feed under commercial conditions may be related to more severe dehydration experienced by hens in multi-bird cages supplied by cup-type watering systems.

Aflatoxicosis alters avian renal function, calcium, and vitamin D metabolism

Experiments were designed to determine the effects of aflatoxicosis on avian renal function, calcium (CA), inorganic phosphorous (Pi), and vitamin D metabolism, and to determine if the effects of aflatoxin are reversible upon discontinuation of toxin administration. Three-week-old male broiler chickens (n = 12 per treatment) received aflatoxin (AF; 2 mg/kg po) or an equal volume of corn oil, the AF carrier vehicle, for 10 consecutive days. After 10 d of treatment, half of the birds from each treatment group were anesthetized and prepared for renal function analysis, which included a 2-h phosphate loading period. Ten days after discontinuation of AF treatment, the remaining birds in each treatment group were anesthetized and prepared for renal function analysis. AF decreased plasma 25-hydroxy vitamin D [25(OH)D] and 1,25-dihydroxy vitamin D [1,25(OH)2D] levels after 5 d of treatment. After 10 d of treatment, urine flow rate (V), fractional sodium excretion (FENa), and fractional potassium excretion (FEK) were lower in AF-treated birds. In addition, total plasma Ca tended to be lower (p = .10) and fractional Ca excretion (FECa) tended to be higher (p = .10) in the AF-treated birds. Intravenous phosphate loading produced a sharp increase in urine hydrogen ion concentration ([H+]) in the AF-treated birds. Glomerular filtration rate (GFR) was reduced and plasma osmolality was increased in AF-treated birds 10 d after discontinuation of toxin administration. The results indicate that AF directly or indirectly affects Ca and Pi metabolism in avians. At the present time, the effects may be related to altered vitamin D and parathyroid hormone (PTH) metabolism. Aflatoxicosis may decrease endogenous PTH synthesis and the renal sensitivity to PTH. The AF-related increase in urine [H+] during phosphate loading is probably due to increased Na+/H+ counterport, suggesting that AF stimulates sodium reabsorption. Also, the decrease in GFR exhibited 10 d after toxin removal indicates that AF may cause prolonged alteration in renal function.