Patho-bacteriological investigation of an outbreak of Mycoplasma bovis infection in calves - Emerging stealth assault

Detection of haptoglobin and serum amyloid A as biomarkers in naturally infected Mycoplasma bovis calves

The livestock sector of Pakistan is increasing rapidly and it plays important role both for rural community and national economy. It is estimated that almost 8 million rural people are involved in livestock rearing and earning about 35-40 % of their income from the livestock sector. Mycoplasma bovis (M. bovis) infection causes significant economic losses in dairy animals especially young calf in the form of clinical illnesses such as pneumonia, poly-arthritis, respiratory distress and mortality. M. bovis is hard to diagnose and control because of uneven disease appearance and it is usually noticed in asymptomatic animals. For the identification of M. bovis in sub-clinical and clinical samples, determination of acute phase proteins i.e., haptoglobin (Hp) and serum amyloid A (SAA) are important tools for the timely diagnosis of disease. Therefore, early diagnosis of disease and hemato-biochemical changes are considered beneficial tools to control the infectious agent to uplift the economy of the dairy farmers. For this purpose, blood samples were collected from 200 calves of Bovidae family. Serum was separated from blood samples to determine the concentration of Hp and SAA, while blood samples were processed to determine hematological changes in blood from calves by using hematological analyzer. The blood plasma obtained from the blood samples was processed to measure oxidative stress factors. Lungs tissues from slaughterhouses/ morbid calves were collected to observe histopathological changes. The results of present study indicated that level of SAA and Hp remarkably increased (P < 0.05) in M. bovis infected calves in comparison to healthy calves. The oxidative stress markers indicated that nitric oxide and MDA levels in the infected calves increased significantly (P < 0.05), while infected claves had considerably lower levels of superoxide dismutase, catalase and glutathione. These findings indicate that oxidative stress play role to increase the level of APPs, while monitoring of APPs levels may serve as a valuable addition to the clinical evaluation of naturally infected calves with M. bovis. The hematological parameters were decreased significantly (P < 0.05). Altogether, this study suggests that Hp and SAA are proposed as promising biomarkers for detecting naturally occurring M. bovis infection in calves.

Al Farraj D, Alzaidi E. Molecular identification of different toxinogenic strains of Clostridium perfringens and histo-pathological observations of camels died of per-acute entero-toxaemia

Enterotoxaemia is a severe disease caused by Clostridium perfringens and render high mortality and huge economic losses in livestock. However, scanty information and only few cases are reported about the presence and patho-physiology of enterotoxaemia in camels. The bacterium induces per-acute death in animals due to rapid production of different lethal toxins. The necropsy of camels (per-acute = 15, acute = 3) was conducted at 18 outbreaks of enterotoxaemia in camels in the desert area of Bahawalpur region. At necropsy, the serosal surfaces of visceral organs in the abdominal, peritoneal and thoracic cavities were found to have petechiation with severe congestion. Moreover, both the cut-sections of different visceral organs and the histo-pathological analysis revealed the pathological lesions in heart, lungs, kidneys, spleen, small and large intestines. Grossly, the kidneys were severely congested, hyperemic, swollen and softer in consistency. Under the microscope, different sections of kidneys indicated that the convulated and straight tubules were studded with erythrocytes. In the intestines, there were stunting fusion of crypts and villi. Similarly, various histo-pathological ailments were also observed in the heart, lungs and spleen. At blood agar, the collected samples showed beta hemolytic colonies of C. perfringens that appeared as medium sized rods microscopically and stained positively on Gram staining. Multiplex PCR revealed C. perfringens type A (α and β2 genes) and D (epsilon gene) and the deaths were found to be significantly higher due to C. perfringens type D compared to those by C. perfringens type A. Hence, it has been concluded that enterotoxaemia in camel affects multiple organs and becomes fatal, if occurred due to C. perfringens type D.

Proteomic Study of Middle Ear Effusion and Its Clinical Application for Otitis Media with Effusion

Background

Proteins found in middle ear effusion play crucial roles in the physiological and pathological processes of otitis media with effusion (OME), influencing the etiology and clinical characteristics of this disease. The qualitative and quantitative composition of these proteins depending on the underlying pathogenesis of middle ear effusion. Understanding their physiological and pathological functions is of great importance.

Methods

We collected samples from 19 volunteers diagnosed with OME. After offline separation using high-pH reversed-phase liquid chromatography (RPLC), the pooled sample was subjected to LC-MS/MS analysis to obtain a comprehensive profile of the OME proteome. Functional analysis was performed using Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Ingenuity Pathway Analysis (IPA) annotations. Data-independent acquisition (DIA) technology was utilized to analyze samples and fix whether the OME proteome could replicate the pathophysiological features associated with this disease. We conducted a differential proteomic analysis between patients with simple OME and patients who had received radiotherapy. The radiotherapy-reduced group was further divided into two subgroups: nasopharyngeal carcinoma (NPC) and other types of carcinoma. Parallel reaction monitoring (PRM) technology was used for validation of 36 differentially expressed proteins (DEPs).

Results

A number of 732 proteins were identified in the OME proteome database. Among them, 527 proteins were quantified using peak intensity-based semi-quantification (iBAQ), covering a wide dynamic range of approximately 8 orders of magnitude. Based on the functional analysis, we proposed a hypothetical mechanism of OME.

Conclusion

This study managed to put up an inclusive analysis of the OME proteome, establishing the first human OME proteome database. We focused on differential proteomic analysis among different groups to gain a more comprehensive concept of the OME proteome and search for meaningful biomarkers.

Characteristics of Mycoplasma bovis, Mycoplasma arginini, and Mycoplasma californicum on immunological response of bovine synovial cells

Mycoplasma arthritis in calves caused by M. bovis exhibits joint swelling, lameness, and immobility. In contrast to M. bovis, M. arginini, and M. californicum which were similarly isolated from the affected joints, only induced mild inflammation. The changes in pathogenesis that depended on species, however, remained unknown. This investigation aims to examine the characteristics of immune responses to M. bovis, M. arginini, and M. californicum in synovial cells. Intracellular M. bovis was detected by gentamicin assay, but M. arginini and M. californicum were not detected. M. bovis-infected synovial cells were encouraged to proliferate and had their apoptosis suppressed. We suggest that M. bovis invaded and inhibited apoptosis of synovial to evade host immunity, which led to long term survival in joints. M. bovis infection significantly increased IL-6 mRNA expression compared to control, although M. arginini and M. californicum infection were comparable to control. We suggest that M. arginini and M. californicum have low abilities to induce inflammation in joints and therefore do not cause severe pathology. Our findings are the first to show the variations in synovial cell immune responses to M. bovis, M. arginini, and M. californicum, which are thought to be related to the pathogenicity of arthritis.

Pathological, Histological, and Molecular Based Investigations Confirm Novel Mycobacterium bovis Infection in Boselaphus tragocamelus

Mycobacterium bovis (M. bovis) being the main cause of animal tuberculosis is a complex infectious agent and can be a cause of zoonotic tuberculosis zoonosis in public health. To date, the uncommon infection in public health due to M. bovis still is a great challenge to both veterinary and medical professions and requires a careful diagnosis and confirmation of the bacterium. Therefore, this study for the first time reports the clinical, gross, histopathological, and molecular based confirmation of M. bovis infection in wildlife animals (nilgai). Prior to death, the morbid animal showed severe pneumonic ailments like moist cough, thick nasal exudates, and dyspnoea. At necropsy, enlargement of mandibular cervical and mesenteric lymph nodes was observed. Different macroscopic lesions such as congestion and hyperaemia, creamy white and catarrhal exudates in trachea, consolidation, grey and red hepatisation of lungs, and micro- and macrogranulomatous tubercles containing caseous materials in lungs were observed. The heart of morbid animal showed congestions, myocarditis, and a copious amount of straw-colored fluid in the pericardial sac. At the microscopic level, lungs indicated granulomatous inflammatory response, presence of multinucleated giant cells, fibrosis, and punctuation of alveoli with chronic inflammatory cells. Histopathological examination of various sections of the heart of the infected animal showed chronic inflammatory response consisting of chronic inflammatory cells like monocyte, lymphocytes, and fibroblasts along with noncalcified eosinophilic materials. At the molecular level, M. bovis infection was confirmed in various tissues like the heart, lungs, cervical, and mesenteric lymph nodes in morbid animals. In conclusion, based on our results, it can be suggested that more molecular based epidemiological studies are crucial to know the exact cause of pulmonary and cervical tuberculosis in wild animals.

Inflammatory cytokine mRNA and protein levels in the synovial fluid of Mycoplasma arthritis calves

Bovine Mycoplasma arthritis (MA) is caused by Mycoplasma bovis and exhibits severe clinical symptoms. However, the pathophysiology of bovine MA is incompletely understood. In this study, we examined the cytokine mRNA expression of synovial fluid (SF) cells and cytokine concentrations in the SF of MA calves. The SF was isolated from five clinically healthy (control) and seven MA calves. mRNA and protein levels of interleukin (IL)-1β, IL-6, IL-8, IL-12, and IL-17 in the SF from MA calves were significantly higher than those from control calves. Our results indicate that SF cells produce inflammatory cytokines, which mainly contribute to the severe inflammatory response in the joints of the MA calves.

Invasion of Mycoplasma bovis into bovine synovial cells utilizing the clathrin-dependent endocytosis pathway

Mycoplasma bovis causes chronic arthritis in cattle, accompanied by a severe inflammatory reaction of the joints. Recent studies demonstrated that M. bovis can invade bovine non-phagocytic cells, but the mechanism of M. bovis internalization in the cells remains unclear. In this study, we examined the mechanism by which M. bovis invades synovial cells, including the pathway of cell invasion. Using fluorescence and electron microscopy, multiple M. bovis were observed to adhere to and be internalized in cultured bovine synovial cells. The number of M. bovis colocalized with clathrin heavy chain (CLTC) per cell was significantly higher than the number of M. bovis colocalized with caveolin-1 (Cav-1). The internalized ratio of M. bovis in synovial cells treated with clathrin-dependent endocytosis inhibitor and small interfering RNA (siRNA) against CLTC was significantly lower than that in control cells. In contrast, the internalized ratio of M. bovis in synovial cells was unaffected by siRNA against Cav-1. These findings provide the first evidence that clathrin-dependent endocytosis is one of the major pathways by which M. bovis invades into synovial cells.

Mycoplasma bovis induces matrix metalloproteinase-3 expression in bovine synovial cells via up-regulation of interleukin-1β expression in mononuclear cells

Mycoplasma bovis causes chronic arthritis in calves, presenting as osteolysis in affected joints. Matrix metalloproteinase-3 (MMP-3), an enzyme involved in cartilage degradation, is produced by synovial cells. Production of this proteinase is regulated by interleukin (IL)-1β, which is produced by mononuclear cells. Both factors are known to play important roles in osteolysis in human autoimmune and bacterial arthritis. However, the pathophysiology of Mycoplasma arthritis (MA) has not been elucidated. In this study, we evaluated the levels of MMP-3 and IL-1β in synovial fluid (SF) from MA calves and examined the effect of IL-1β on MMP-3 expression in bovine synovial cells in vitro. Levels of MMP-3 and IL-1β in SF from MA calves were significantly higher than those of clinically healthy calves. Mycoplasma bovis induced significant increases in the expression of IL-1β mRNA and protein in mononuclear cells, compared with cells not exposed to M. bovis. Interestingly, the supernatant of mononuclear cells stimulated with M. bovis contained high levels of IL-1β, which induced higher expression of MMP-3 mRNA and protein in synovial cells than direct stimulation by M. bovis. Recombinant bovine IL-1β also induced increased MMP-3 mRNA and protein expression in synovial cells. Our results indicate that M. bovis induces IL-1β expression by bovine mononuclear cells, and this cytokine then promotes MMP-3 production by synovial cells. These findings suggest that MMP-3 and IL-1β are key factors in the development of osteolysis in MA calves.

Effect of Mycoplasma bovis on expression of inflammatory cytokines and matrix metalloproteinases mRNA in bovine synovial cells

Mycoplasma bovis causes chronic arthritis in calves. Mycoplasma arthritis shows severe inflammatory reactions in joints that is commonly treated with antibiotics and results in significant economic losses in the calf industry. A previous study showed that inflammatory cytokines and matrix metalloproteinases (MMPs) produced by synovial cells promote progression of the pathophysiology of bacterial arthritis. However, the mechanism underlying the pathogenesis of bovine Mycoplasma arthritis has not been fully clarified. In this study, we examined the immunologic response of bovine synovial tissue to M. bovis. We observed significant increases in expression of interleukin (IL)-1β, IL-6, IL-8, MMP-1, and MMP-3 mRNA in synovial tissue from Mycoplasma arthritis calves compared with tissues from normal calves. Expression of IL-6, IL-8, and MMP-1 mRNA was also induced in cultured synovial cells stimulated with M. bovis, but not expression of IL-1β and MMP-3 mRNA. In contrast, the culture supernatant of peripheral blood mononuclear cells stimulated with M. bovis induced marked increases in the expression of IL-1β, IL-6, IL-8, MMP-1, and MMP-3 mRNA in synovial cells. Our results indicate that inflammatory cytokines and MMPs produced by synovial cells play a key role in the pathogenesis of Mycoplasma arthritis. We suggest that interactions between synovial cells and mononuclear cells in the presence of M. bovis induce expression of these cytokines and MMPs in synovial cells, resulting in severe inflammatory reactions in the joints.

Mycoplasma bovis and viral agents associated with the development of bovine respiratory disease in adult dairy cows

The etiology and pathologic findings of bovine respiratory disease (BRD) in adult dairy cows (n = 35) from a commercial dairy herd in Southern Brazil were investigated. Pulmonary samples were examined for histopathologic patterns and specific features within these patterns, while immunohistochemical (IHC) assays were designed to detect the intralesional antigens of viral infectious disease agents and Mycoplasma bovis. Pneumonia was diagnosed in 91.4% (32/35) of these cases; neither pneumonia nor any of the infectious disease pathogens evaluated occurred in three cows. The presence of multiple respiratory pathogens in 75% (24/32) of these cases indicated the complex origin of pneumonia in cattle. Interstitial pneumonia, necrosuppurative bronchopneumonia and suppurative bronchopneumonia were the principal patterns of pulmonary disease identified by histopathology. The most frequent pathogens identified by IHC were bovine viral diarrhea virus (BVDV; n = 18), M. bovis (n = 16) and bovine alphaherpesvirus type 1 (BoHV-1; n = 14), followed by bovine respiratory syncytial virus (BRSV; n = 11) and bovine parainfluenza virus type 3 (BPIV-3; n = 5). Obliterative bronchiolitis and peribronchial lymphocytic cuffings were the characteristic histopathologic features associated with M. bovis. Necrohemorrhagic bronchitis with bronchial angiogenesis was associated with BoHV-1. Necrotizing bronchitis and bronchiolitis were associated with BVDV, BoHV-1 and BRSV. Ballooning degeneration of the bronchial and bronchiolar epithelia was associated with BRSV and BoHV-1. This is the first report from Brazil that correlated the histopathologic findings of BRD with the associated infectious disease agents by immunohistochemistry. M. bovis was frequently detected in the tissues of cows with fatal pulmonary disease during this study and may be a possible primary disease pathogen associated with the development of BRD in dairy cows. Additionally, the histopathologic features identified within patterns of pulmonary disease during this investigation may be an efficient diagnostic tool to associate histopathologic findings with specific agents of BRD in dairy cows.

Mycoplasma bovis arthritis and pneumonia in calves in Jordan: An emerging disease

Aim:

Clinical, microbiological, molecular, and pathological assays were undertaken to characterize an outbreak of increasingly reported signs of unresponsive arthritis and pneumonia of Mycoplasma bovis infection in young calves in Jordan.

Materials and Methods:

Clinical history of the affected bovine herd was investigated for the presence of respiratory and/or joint problems. Two calves with such history were clinically examined and necropsied. Representative tissues were sent for microbiological, molecular, and pathological examinations for M. bovis infection.

Results:

The outbreak started in a herd of 220 nursing calves, 2 months before the receiving of two calves for postmortem examination. Clinically, respiratory signs and infection of one or more joints dominated in the affected calves. The morbidity and case fatality rates were 27.27% and 61.7%, respectively. The left carpal joint was markedly swollen in both calves and exhibited necrofibrinous to granulomatous arthritis in varying degrees of severity. The anteroventral lung lobes in both calves were consistently affected and revealed multifocal to coalescing severe necrogranulomatous and fibrinopurulent bronchopneumonia. Microbiological and molecular findings confirmed the pathological examination. Furthermore, bovine viral diarrhea (BVD) was diagnosed in one calf by histopathology and polymerase chain reaction.

Conclusion:

This investigation reports the first outbreak of M. bovis infection in calves located in Jordan that could occur concurrently with BVD.

Clinico-hematological and oxidative stress status in Nili Ravi buffaloes infected with Trypanosoma evansi

Hemoparasitic diseases like trypanosomiasis have an adverse influence on the health and working capability of infected animals. Monitoring and identification of blood born parasitic infections in dairy animals are of vital importance to get the optimum production. In this study blood samples were collected from Nili Ravi buffaloes (n = 390) kept at different villages of district Lodhran, Punjab province of Pakistan. Blood samples were evaluated for red blood cell counts, total and differential leukocyte counts, hematocrit, hemoglobin, total proteins and different serum parameters such as alanine aminotransferase, aspartate aminotransferase, malondialdehyde, alkaline phosphatase, lactate dehydrogenase, phosphorous, copper, calcium and magnesium. Overall prevalence of Trypanosoma evansi was 4.61% based on microscopic smear examination, 11.02% with Formol Gel Test and 16.15% with PCR. Infected buffaloes showed different clinical signs, including high fever (105 ± 1.0 °F), edema of face and legs, hyperemic mucosa of eyes, lachrymation, bulging eyes, pale mucus membranes and frequent urination. Microscopic examination of blood films showed morphologically different parasites. Statistical analysis did not indicate an association of infection based on age and sex of buffaloes. Results revealed significantly (p < 0.05) lower values of red blood cell counts, hemoglobin, hematocrit, mean corpuscular hemoglobin concentration and total proteins, while increased values of mean corpuscular volume, total white blood cells, monocyte, neutrophils, basophils and eosinophils in infected animals. Infected buffaloes were suffering from macrocytic hypochromic anemia. A significant (p < 0.05) increase in serum lipid per oxidation product (malondialdehyde) level and serum enzymes while a decrease in macrominerals and trace mineral (copper) in trypanosomiasis positive buffaloes were recorded. It was concluded that Trypanosoma evansi is prevalent in Pakistan under tropical and subtropical climatic conditions. It causes clinical disease with macrocytic hypochromic anemia and oxidative stress in infected buffaloes.