ABSTRACT
Scrub typhus is a re-emerging disease caused by Orientia tsutsugamushi, transmitted by mites belonging to the family Trombiculidae. Humans and rodents acquire the infection by the bite of larval mites/chiggers. Suncus murinus, the Asian house shrew, has been reported to harbor the vector mites and has been naturally infected with O. tsutsugamushi. The present study aimed to localize and record O. tsutsugamushi in the tissues and the host response in shrews naturally infected with O. tsutsugamushi. Sheehan's modified May-Grunwald Giemsa staining was carried out in 365 tissues from 87 animals, and rickettsiae were documented in 87 tissues from 20 animals. Immunohistochemical (IHC) staining, using polyclonal antibodies raised against selected epitopes of the 56-kDa antigen, was carried out, and 81/87 tissue sections were tested positive for O. tsutsugamushi. By IHC, in addition to the endothelium, the pathogen was also demonstrated by IHC in cardiomyocytes, the bronchiolar epithelium, stroma of the lungs, hepatocytes, the bile duct epithelium, the epithelium and goblet cells of intestine, the tubular epithelium of the kidney, and splenic macrophages. Furthermore, the pathogen was confirmed by real-time PCR using blood (n = 20) and tissues (n = 81) of the IHC-positive animals. None of the blood samples and only 22 out of 81 IHC-positive tissues were tested positive by PCR. By nucleotide sequencing of the 56-kDa gene, Gilliam and Karp strains were found circulating among these animals. Although these bacterial strains are highly virulent and cause a wide range of pathological alterations, hence exploring their adaptive mechanisms of survival in shrews will be of significance. Given that the pathogen localizes in various organs following a transient bacteremia, we recommend the inclusion of tissues from the heart, lung, intestine, and kidney of reservoir animals, in addition to blood samples, for future molecular surveillance of scrub typhus.
ABSTRACT
Steroid hormones are found to play a major role in the genesis and progression of mammary tumors. The aim of this study was to immunohistochemically detect the presence of estrogen receptor alpha (ER α ), estrogen receptor beta (ER ß ), and progesterone receptor (PR) and also to study the association between these markers in 29 cases of benign (11) and malignant (18) canine mammary tumors. ER α immunostaining was noticed in only one case of carcinosarcoma specifically in the nuclei of epithelial and a few myoepithelial cells. ER ß immunostaining was noticed in the nuclei and cytoplasm of epithelial cells and smooth muscles lining the blood vessels. Immunoexpression of ER ß was 82% in benign tumors and 78% in malignant tumors. PR immunostaining was expressed in the nuclei of epithelial cells in both benign and malignant tumors. Among the 15 PR+ cases, 6 (55%) were of benign type, and 9 (50%) were of malignant type. The most common group of hormone receptor was the ER α -/PR+/ER ß + (46%) in benign tumors and ER α -/PR-/ER ß + (38%) in malignant tumors. Although there was no significant association between ER α and PR with ER ß , the findings indicated that ER ß was consistently expressed in both benign and malignant tumors, irrespective of ER α and PR status.
ABSTRACT
The present study was carried out to record the occurrence of naturally occurring granulomas in cattle and buffaloes. Tissues grossly suspected for granulomas were collected from 336 out of 1600 (21%) abattoir cases. The gross features ranged from focal necrosis to large caseated masses, hard nodules, growths and abscesses. Histopathologically, 102 tissue samples (6.38%) were ascertained as granulomas. Majority of the granulomas were found in the liver 42 (41.18%), followed by lungs 22 (20.59%), lymph nodes 11 (10.78%), kidneys 6 (5.88%) and 14 (13.73%) as subcutaneous nodules/growths. Solitary cases were found in tongue, muscle, and urinary bladder, whereas 4 granulomas (3.92%) were found in body cavities. Based on the cellular component, the granulomas were categorized as epithelioid (53%), eosinophilic (37%) and suppurative (10%). Employing special staining techniques, the possible etiology of 75 granulomas could be identified. Among these, 70 granulomas (68.63%) were of infectious nature (parasitic 37 (36.28%), bacterial 32 (31.37%), and fungal 1(0.98%)). Non-infectious granulomas 5 cases (4.90%) included two lipid granulomas (1.96%), two granulomas (1.96%) associated with neoplasms and one (0.31%) associated with renal calculi. In 27 (26.47%) cases, the etiology of the granuloma could not be established and were categorized as granulomas of unknown etiology.
