Biochemical Profile of Milk of Buffalo (Bubalus bubalis), Cow (Bos taurus) and Goat (Capra hircus): Potential Candidates for Supporting the Growth of Leishmania donovani Promastigotes in Culture Medium as Alternative to Fetal Bovine Serum (FBS)

The milk of cow (Bos taurus), buffalo (Bubalus bubalis), and goat (Capra hircus) were investigated for thebiochemical profile such as glucose, total protein, triglycerides, cholesterol and calcium. Although used as potentialcandidate to replace fetal bovine serum in the culture medium for the cultivation of parasitic protozoan such asLeishmania donovani promastigotes, the biochemical profile of milk will provide information about which factor supportsand essential for the growth of parasite. We found triglycerides were predominant in goat followed by cow and buffalomilk. The level of cholesterol was high in buffalo milk followed by goat and FBS. The level of calcium was high in buffalomilk followed by goat and cow milk

Detection of Wolbachia endobacteria in Culex quinquefasciatus by Gimenez staining and confirmation by PCR

Background & objectives: Wolbachia are common intracellular bacteria that are found in arthropods and nematodes.These endosymbionts are transmitted vertically through host eggs and alter host biology in diverse ways, includingthe induction of reproductive manipulations, such as feminization, parthenogenesis, male killing and sperm-eggincompatibility. Since they can also move horizontally across species boundaries, Wolbachia is gaining importancein recent days as it could be used as a biological control agent to control vector mosquitoes or for paratransgenicapproaches. However, the study of Wolbachia requires sophisticated techniques such as PCR and cell culturefacilities which cannot be affordable for many laboratories where the diseases transmitted by arthropod vectorsare common. Hence, it would be beneficial to develop a simple method to detect the presence of Wolbachia inarthropods.Method: In this study, we described a method of staining Wolbachia endobacteria, present in the reproductivetissues of mosquitoes. The reliability of this method was compared with Gram staining and PCR based detection.Results: The microscopic observation of the Gimenez stained smear prepared from the teased ovary of wildcaught and Wolbachia (+) Cx. quinquefasciatus revealed the presence of pink coloured pleomorphic cells ofWolbachia ranging from cocci, comma shaped cells to bacillus and chain forms. The ovaries of Wolbachia (–)cured mosquito did not show any cell. Although Gram’s staining is a reliable differential staining for the otherbacteria, the bacterial cells in the smears from the ovaries of wild caught mosquitoes did not take the stain properlyand the cells were not clearly visible. The PCR amplified product from the pooled remains of wild caught andWolbachia (+) Cx. quinquefasciatus showed clear banding, whereas, no banding was observed for the negativecontrol (distilled water) and Wolbachia (–) Cx. quinquefasciatus.Interpretation & conclusion: The Gimenez staining technique applied, could be used to detect the members of theendobacteria Wolbachia easily, even in a simple laboratory without any special facilities or even in the fieldcondition and for handling large number of samples in a shorter duratio

Health-seeking behaviour, diagnostics and transmission dynamics in the control of visceral leishmaniasis in the Indian subcontinent.

Countries in the Indian subcontinent have committed to reducing the incidence of kala-azar, a clinical manifestation of visceral leishmaniasis, to below 1 in 10,000 by 2020. We address the role of timing of use and accuracy of diagnostics in kala-azar control and elimination. We use empirical data on health-seeking behaviour and health-system performance from the Indian state of Bihar, Bangladesh and Nepal to parameterize a mathematical model. Diagnosis of cases is key to case management, control and surveillance. Treatment of cases prevents onward transmission, and we show that the differences in time to diagnosis in these three settings explain the observed differences in incidence. Shortening the time from health-care seeking to diagnosis is likely to lead to dramatic reductions in incidence in Bihar, bringing the incidence down to the levels seen in Bangladesh and Nepal. The results emphasize the importance of maintaining population and health-system awareness, particularly as transmission and disease incidence decline. We explore the possibility of diagnosing patients before the onset of clinical kala-azar (before 14 days fever), and show that this could have a marked impact on incidence, even for a moderately sensitive test. However, limited specificity (that results in false positives) is a major barrier to such a strategy. Diagnostic tests of high specificity used at an early stage of active infection, even if sensitivity is only moderate, could have a key role in the control of kala-azar, and prevent its resurgence when paired with the passive health-care system and tests of high sensitivity, such as the test for rK39 antibody response

Japanese Encephalitis vector abundance and infection frequency in Cuddalore District, Tamil Nadu, India: a five-year longitudinal study

An entomological monitoring of Japanese encephalitis vectors from the Cuddalore district, Tamil Nadu was undertaken at biweekly intervals for 1 hr after dusk for five years to find out the abundance and JE virus activity longitudinally in three villages. A total of 95,644 vectors belonging to 31 species constituted predominantly by Culex vishnui subgroup and Culex gelidus 98.5%. JE virus was identified from Cx. tritaeniorhynchus (18), Cx. vishnui (1) and Cx. gelidus (6) giving infection rate of 0.482, 0.608 and 0.221 respectively. Abundance of Cx. tritaeniorhynchus and Cx. gelidus differed significantly by area, season and year (P&lt;0.05) whereas Cx. vishuni differed significantly by season and year (P&lt;0.05). Transmission was not observed throughout all the seasons and the infection rate was recorded maximum during Hot-Wet season 0.46 (confidence interval: 0.17-1.02). Culex tritaeniorhynchus dominated the catch and the Culex gelidus steadily increased in its abundance during this period compared to the earlier studies conducted from these areas which acts as a secondary vector along with the major vector, Cx. tritaeniorhynchus.</em

Milk of Cow (Bos taurus), Buffalo (Bubalus bubalis), and Goat (Capra hircus): a Better Alternative than Fetal Bovine Serum in Media for Primary Isolation, In Vitro Cultivation, and Maintenance of Leishmania donovani Promastigotes

Tyndalized milk of goat, cow, and buffalo was found to be a potential substitute for fetal bovine serum (FBS) in the medium for the cultivation of Leishmania donovani promastigotes. The numbers (means) of promastigotes reached 2.6 × 10(7), 2.3 × 10(7), and 2.1 × 10(7)/ml, respectively, in the medium supplemented with 10% milk of goat, cow, and buffalo, in comparison to 1.9 × 10(7)/ml in the control with 10% FBS. In primary isolation, the milk-supplemented medium showed that 22 out of 26 samples were positive for promastigotes (84.6%) and the cells were maintained successfully during the observed period of 6 months

Seasonal abundance & role of predominant Japanese encephalitis vectors Culex tritaeniorhynchus & Cx. gelidus Theobald in Cuddalore district, Tamil Nadu

Background & objectives: Japanese encephalitis (JE) is the leading cause of viral encephalitis in Asia. The first major JE outbreak occurred in 1978 and since 1981 several outbreaks had been reported in the Cuddalore district (erstwhile South Arcot), Tamil Nadu, India. Entomological monitoring was carried out during January 2010 - March 2013, to determine the seasonal abundance and transmission dynamics of the vectors of JE virus, with emphasis on the role of Culex tritaeniorhynchus and Cx. gelidus. Methods: Mosquito collections were carried out fortnightly during dusk hours in three villages viz. Soundara Solapuram, Pennadam, Erappavur of Cuddalore district. Mosquitoes were collected during dusk for a period of one hour in and around the cattle sheds using oral aspirator and torch light. The collected mosquitoes were later identified and pooled to detect JE virus (JEV) infection by enzyme linked immunosorbent assay (ELISA). Results: A total of 46,343 mosquitoes comprising of 25 species and six genera were collected. Species composition included viz, Cx. tritaeniorhynchus (46.26%), Cx. gelidus (43.12%) and other species (10.62%). A total of 17,678 specimens (403 pools) of Cx. gelidus and 14,358 specimens (309 pools) of Cx. tritaeniorhynchus were tested, of which 12 pools of Cx. gelidus and 14 pools of Cx. tritaeniorhynchus were positive for JE virus antigen. The climatic factors were negatively correlated with minimum infection rate (MIR) for both the species, except mean temperature (P<0.05) for Cx. gelidus. Interpretation & conclusions: High abundance of Cx. tritaeniorhynchus and Cx. gelidus was observed compared to other mosquito species in the study area. Detection of JEV antigen in the two species confirmed the maintenance of virus. Appropriate vector control measures need to be taken to reduce the vector abundance

Changing paradigm in the epidemiology of Japanese encephalitis in a non-endemic region

Background & objectives: Japanese encephalitis (JE) is a mosquito-borne zoonotic disease. The JE virus (JEV) does not cause any disease among its natural hosts and transmission continues through mosquitoes belonging to Culex vishnui subgroup. This study was aimed to investigate the prevalence of JEV in mosquitoes and humans in the Thanjavur district, a non-endemic region for JE, in Tamil Nadu, by using standard available assays. Methods : A sero-surveillance study was conducted in Thanjavur district among the normal rural school children in the 5–12 yr age group, during the JE season (October) and post-JE season (February) from 2011 to 2013 for the detection of JEV infection. Vector abundance studies were carried out from 2011 to 2014. JE seropositivity and its association between the seasons were analysed statistically. Results : The occurrence of JE infection among children aged 5–12 yr was very high in the study area. The infection rates for JE in two consecutive seasons for 2011–12 and 2012–13 were 32.2 and 65.2%, respectively. The Cx. tritaeniorhynchus sp. dominated the catch, and was majorly responsible for the transmission. There was a significant difference in the human infection rate compared to the years 1991–92 and 1992–93; and a marked decrease in the cattle to pigs ratio (123 : 1) compared to the studies in 1991–93. Interpretation & conclusion : The study unearthed the prevailing situation of JE among children, who are at higher risk of developing the disease during the transmission season. The decrease in the cattle to pigs ratio might be the one of the reasons for increase in the JEV infection among the children population compared to 20 years before. This trend requires urgent attention as it could be prevented with effective surveillance systems and vaccines