RESUMO
Leprosy is a chronic granulomatous disease affecting skin, peripheral nerves and other tissues. On histopathology leprosy mimics other infectious and non-infectious lesions like tuberculosis, sarcoidosis and fungal infections, which are also common in our country. In tuberculoid and indeterminate forms, where Acid Fast Bacilli cannot be demonstrated, the diagnosis becomes more difficult. Mycobacterium leprae is the only bacterium which has the ability to infiltrate peripheral nerves leading to Schwann cell disintegration. On routine Hematoxylin and Eosin stains (H&E), the nerve fibers may not be easily identifiable in some cases , hence S-100 immunostaining is used to highlight the nerve elements and to demonstrate and compare the nerve changes in spectrum of leprosy. With widespread use of multi-drug treatment, there has been changes in the profile of disease. The aim of the present study was to observe different patterns of cutaneous nerve involvement in leprosy and to correlate these with the clinical and histopathological findings in currently referred cases for histopathological opinion. The study was conducted in the Department of Pathology, Himalayan Institute of Medical Sciences, Swami Rama Himalayan University, Dehradun, over a period of 12 months (July 2016 - July 2017) Subjects were recruited from patients presenting in Dermatology OPD. A total 35 consecutive cases with clinical suspicion / diagnosis of leprosy were included in the study. Biopsies were processed and stained by H&E, Fite-Faraco as well as S100 immunostaining. It was observed that on S-100 immunostaining, 43.7% cases showed granulomas infiltrating the dermal nerves whereas these changes could not be demonstrated in 16.6% cases of Borderline leprosy on H&E staining alone. Thus S-100 staining appears to serve as an important tool to diagnose leprosy from other granulomatous diseases of skin even in current scenario of leprosy.
RESUMO
Streptococcosis/lactococcosis is the cause of high morbidity and mortality in aquaculture sector and to date a number of species of Streptococcus and Lactococcus genera including S. iniae, S. agalactiae, S. dysagalactiae, S. parauberis, S. feacalis, L. garvieae and L. lactis have been discriminated as the cause of disease in aquatic animals. Despite the use of diagnostic molecular methods for each of these bacterial species, no data is available on a suitable, rapid and simple simultaneous detection tool for these pathogens. This paper describes a simultaneous detection method which is PCR based on a reverse line blot [RLB] for rapid detection and differentiation of four species of genera of Streptococcus and Lactococcus genera consisting of S. iniae, S. agalactiae, S. parauberis and L. garvieae the most important agents of the disease in fish. A reverse line blot [RLB] assay was developed for the simultaneously identification of four species of Streptococcus/lactococcusconsisting of S. iniae, S. parauberis, S. agalactiaeand Lactococcusgarvieae. The assay employs one set of primer pair for specific amplification of the 16S rRNA gene. These were designed based on the nucleotide sequences of 16S rRNA gene sharing a homology region with Streptococcus spp. and Lactococcus spp. DNA was extracted from the pure bacterial colonies and amplified. A membrane was prepared with specific oligonucleotide for each bacterial species. PCR products were then hybridized to a membrane. The amplification resulted in PCR product of 241 bp in length. No cross-reactions were observed between any of the tested bacterial species, and mixed DNAs from these four bacterial species were correctly identified. This RLB method is a suitable technique for a simultaneous detection of these species of bacterial fish pathogens that are some of the main causes of streptococcal/lactococcal infections in both freshwater and marine aquatic animals, and so we recommend its use for integrated epidemiological monitoring of streptococcosis/lactococcis in aquaculture industry.