A histopathological study of Penaeus monodon showing
external symptoms of white spot disease, collected
from culture ponds at Mulakuddu and Rambilli villages (Visakhapatnam District) during May and July 2001, provided evidence for the occurrence of multiple viral infections. Each diseased shrimp carried concurrent infections with four different viruses, identified on the basis of nuclear changes, resulting in the formation of characteristic inclusion/occlusion bodies, as WSSV, YHV, MBV and IHHNV. The identification of the various viruses needs confirmation
through molecular diagnostic methods. This constitutes
a report recording concurrent infections with multiple viruses in a single shrimp.
Pseudomonas aeruginosa (PIC 4), isolated from coastal waters of Visakhapatnam (Gen Bank Accession no: KF803248) was tested for its antagonistic activity against Vibrio harveyi as probiotic in cultured Penaeus monodon. Pseudomonas aeruginosa PIC 4 has proved to be non-pathogenic to the shrimp by pathogenicity tests. Vibrio counts in probiotic fed shrimp and the surrounding water medium were significantly lower when compared to the control group of shrimp and water during 50 days of culture. Mean weight of probiont fed shrimps after 50 days of culture was (2.21 + 0.15 g) , significantly higher than that of normal diet fed ones (1.33+0.18 g). Survival percent was also significantly higher in probiont fed shrimp (47.33% + 5.55%) than that of the control diet fed shrimp (26.33% + 7%). Percent survival in probiotic fed and normal diet fed shrimp after the challenge with V. harveyi was 93.04 and 38.87 respectively.
Abstract HSV-2 infection is common and generally asymptomatic, but it is associated with increased HIV susceptibility and disease progression. This may relate to herpes-mediated changes in genital and systemic immunology. Cervical cytobrushes and blood were collected from HIV-uninfected African/Caribbean women in Toronto, and immune cell subsets were enumerated blindly by flow cytometry. Immune differences between groups were assessed by univariate analysis and confirmed using a multivariate model. Study participants consisted of 46 women, of whom 54% were infected with HSV-2. T cell activation and expression of the mucosal homing integrin α4β7 (19.60 versus 8.76%; p < 0.001) were increased in the blood of HSV-2–infected women. Furthermore, expression of α4β7 on blood T cells correlated with increased numbers of activated (coexpressing CD38/HLA-DR; p = 0.004) and CCR5+ (p = 0.005) cervical CD4+ T cells. HSV-2–infected women exhibited an increase in the number of cervical CD4+ T cells (715 versus 262 cells/cytobrush; p = 0.016), as well as an increase in the number and proportion of cervical CD4+ T cells that expressed CCR5+ (406 versus 131 cells, p = 0.001; and 50.70 versus 34.90%, p = 0.004) and were activated (112 versus 13 cells, p < 0.001; and 9.84 versus 4.86%, p = 0.009). Mannose receptor expression also was increased on cervical dendritic cell subsets. In conclusion, asymptomatic HSV-2 infection was associated with significant systemic and genital immune changes, including increased immune activation and systemic α4β7 expression; correlation of the latter with highly HIV-susceptible CD4+ T cell subsets in the cervix may provide a mechanism for the increased HIV susceptibility observed in asymptomatic HSV-2–infected women.
Genital inflammation is a key determinant of human immunodeficiency virus (HIV) transmission, and may increase HIV-susceptible target cells and alter epithelial integrity. Several genital conditions that increase HIV risk are more prevalent in African, Caribbean, and other black (ACB) women, including bacterial vaginosis and herpes simplex virus type-2 (HSV-2) infection. Therefore, we assessed the impact of the genital microbiota on mucosal immunology in ACB women and microbiome-HSV-2 interactions. Cervicovaginal secretions and endocervical cells were collected by cytobrush and Instead Softcup, respectively. T cells and dendritic cells were assessed by flow cytometry, cytokines by multiplex enzyme-linked immunosorbent assay (ELISA), and the microbiota by 16S ribosomal ribonucleic acid gene sequencing. The cervicovaginal microbiota of 51 participants were composed of community state types (CSTs) showing diversity (20/51; 39%) or predominated by Lactobacillus iners (22/51; 42%), L. crispatus (7/51; 14%), or L. gasseri (2/51; 4%). High-diversity CSTs and specific bacterial phyla (Gardnerella vaginalis and Prevotella bivia) were strongly associated with cervicovaginal inflammatory cytokines, but not with altered endocervical immune cells. However, cervical CD4+ T-cell number was associated with HSV-2 infection and a distinct cytokine profile. This suggests that the genital microbiota and HSV-2 infection may influence HIV susceptibility through independent biological mechanisms.
Abstract.— Surveys undertaken on diseases caused by Vibrio spp. in Penaeus monodon from culture ponds of coastal Andhra Pradesh recorded the occurrence of five types of diseases: tail necrosis, shell disease, red disease, loose shell syndrome (LSS), and white gut disease (WGD). Among these, LSS, WGD, and red disease caused mass mortalities in shrimp culture ponds. Six species of Vibrio—V. harveyi , V. parahaemolyticus, V. alginolyticus, V. anguillarum , V. vulnificus , and V. splendidus —are associated with the diseased shrimp. The number of Vibrio spp. associated with each disease ranged from two to five. Additionally, shrimp with red disease had concurrent infections with white spot syndrome virus. Vibrio harveyi in the case of LSS and WGD, V. parahaemolyticus for red disease, and V. alginolyticus for shell disease are the major etiologcal agents. Differences occur in the degree of virulence of different species of Vibrio and also different isolates of the same species. Vibrio harveyi isolated from LSS shrimp is the most virulent. In general, all the Vibrio isolates from LSS shrimp tend to be more virulent as compared to their counterparts from other diseased shrimp. It is apparent that the degree of virulence of various Vibrio isolates depends on its source and the pond environmental conditions. Most of the Vibrio isolates showed susceptibility to oxytetracycline, norfloxacin, and ciprofloxacin. The luminous V. harveyi exhibited resistance to many antibiotics and susceptibility to only three drugs. Considering the emergence of antimicrobial resistant strains of Vibrio , the need for using probiotics in place of antibiotics for disease control is stressed.
Shrimps affected by monodon slow growth syndrome (MSGS) were sampled from culture ponds in Amalapuram and Bhimavaram areas of Andhra Pradesh during 2005-2010 and subjected to bacteriological as well as histopathological investigations. Three species of Vibrios were identified in the bacterial isolates from haemolymph viz ., V. alginolyticus , V. fluvialis and V. harveyi . Histopathological studies revealed major changes in the hepatopancreas as well as gill tissue and the presence of monodon baculovirus (MBV), heptopancreatic parvo virus (HPV) and Infectious hypodermal and hepatopancreatic necrosis virus (IHHNV). Fifty percent of the MSGS affected shrimps showed single infections with MBV, 20% with HPV and 30% had dual infections of HPV and MBV.
Antibacterial activity of five marine microalgae Isochrysis galbana, Chaetoceros calcitrans, Tetraselmis suecica, Nannochloropsis oculata, Aphanocapsa sp. was studied from Visakhapatnam.The ethanolic extract of T. suecica, C. calcitrans, and N. oculata s howed inhibitory activity against V. harveyi and S. Aureus with inhibition zone between 11.5 and 20mm.The ethanolic extract of I. galbana showed inhibitory activity against S. aureus only with an inhibition zone of 15mm.Among the four extracts, T. suecica showed maximum inhibitory activity against V. harveyi with an inhibition zone of 20mm.The methanolic extract of T. suecica moderately inhibited the growth of V. harveyi and S. aureus with inhibition zones of 11.5 and 11 mm respectively, whereas the extracts of I. Galbana and C. Calcitrans inhibited only V. harveyi with inhibition zones of 10 and 12 mm respectively, but no activity was found against S. aureus, A. hydrophila and E. coli.So, the studied microalgae could be used as a potential source to extract, bioactive marine natural compounds with antibacterial activity. INTRODUCTION:Natural products from marine organisms have recently acquired importance in the pharmaceutical and pesticide industries.Marine organisms could be a potential source of bioactive secondary metabolites that represent useful leads in the development of new pharmaceutical agents 1, 2 .Many chemically distinct marine compounds with various biological activities have been isolated to date, and a number of them are being investigated and/or developed as new pharmaceutical products 3- 5 .More than 10,000 compounds have been isolated from marine organisms so far, with hundreds (or) more being discovered every year 6, 7 .
Juveniles of two species of commercially important prawns, Metapenaeus dobsoni (Miers) and Macrobrachium rosenbergii (De Man) collected from Gosthani estuary, Bheemunipatnam near Visakhapatnam, India during the period August 1995 to August 1996 were subjected to a detailed study with a view to identifying the various species of epibionts and parasites and to monitor the seasonal changes in the occurrence and abundance of common species of ciliates and larval helminths. A wide range of protozoan and metazoan parasite species was encountered in the prawns. The protozoans were represented by epicommensal ciliates belonging to the genera Zoothamnium, Epistylis, Acineta, Vorticella, an unidentified apostome ciliate and two species of gregarines. The metazoan parasites included metacercariae of families Opecoelidae and Microphallidae, a larval cestode, a larval nematode and two species of bopyrid isopods. Altogether eight species were found infecting M. rosenbergii and 11 species infected M. dobsoni. A majority of the parasite species infected both the hosts. The peritrichous and apostome ciliates constituted the dominant members of the parasite fauna, occurring on both species of prawns as epibionts with high prevalence and density. All the other infections were rarely encountered. Infections with gregarines were restricted to M. dobsoni while those of microphallid metacercariae were found only in M. rosenbergii. Zoothamnium infections were more common on M. rosenbergii than on M. dobsoni. Apparent differences in the parasite fauna, attributed to differences in the behaviour of the two species, were noted. Seasonally Zoothamnium infections were at their peak during monsoon and post-monsoon months and these infections appear to be governed directly by salinity of the habitat and indirectly by the rainfall. Apostome ciliate infections were at their peak during the months November and February. Opecoelid metacercarial infections were confined to the period August to February, with peak during summer months.
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