Development of recombinant subunit vaccine targeting InvH protein of Salmonella Typhimurium and evaluation of its immunoprotective efficacy against salmonellosis.

Salmonella Typhimurium is the most prevalent non-host specific Salmonella serovars and a major concern for both human and animal health systems worldwide contributing to significant economic loss. Type 3 secretion system (T3SS) of Salmonella plays an important role in bacterial adherence and entry into the host epithelial cells. The product of invH gene of Salmonella is an important component of the needle complex of the type 3 secretion system. Hence, the present study was undertaken to clone and express the 15 kDa InvH surface protein of Salmonella Typhimurium in an E. coli host and to evaluate its immune potency in mice. The purified recombinant InvH (r-InvH) protein provoked a significant (p < 0.01) rise in IgG in the inoculated mice. The immunized mice were completely (100%) protected against the challenge dose of 107.5 LD50, while protection against challenge with the same dose of heterologous serovars was 90%. The bacterin-vaccinated group showed homologous protection of 60% against all three serovars. Findings in this study suggest the potential of the r-InvH protein of S. Typhimurium as an effective vaccine candidate against Salmonella infections.

Prevalence, antimicrobial resistance and virulence genes of Salmonella serovars isolated from humans and animals.

We investigated the prevalence, antimicrobial susceptibility, antimicrobial resistance and virulence genes of Salmonella isolates recovered from humans and different species of animals. Out of 1231 samples, 88 (7.15%) Salmonella isolates were obtained, among which 21 (23.86%) belonged to Salmonella enterica subsp. enterica sero var. Weltevreden, 22 (25%) to S. Enteritidis, 16 (18.2%) to S. Typhi and 14 (15.9%) to S. Newport; 7 (7.95%) isolates were untypable. Among the 88 isolates, 65.90% showed resistance to gentamicin, 61.36% to tetracycline, 61.18% to cefotaxime, 48.86% to trimethoprim, 45.45% to ampicillin, 11.36% to ceftriaxone, 10.22% to chloramphenicol and 7.95% each to ciprofloxacin and cefepime. Most of the isolates were susceptible, with a low MIC (≤ 0.25 µg/ml) value, to cefepime, cefotaxime, ciprofloxacin, ceftriaxone and co-trimoxazole and with a moderate MIC (0.5-4 µg/ml) to ampicillin, tetracycline, gentamicin and chloramphenicol. The resistance genes blaTEM, tetA and dfrA12 were most prevalent, irrespective of the host of origin of the isolates. While invA was used for molecular detection of Salmonella, other virulence genes, viz. sipA, sipB, sipC, stn and pagN, were also detected in all Salmonella isolates. A total of 38.64% isolates were multidrug-resistant (MDR), and various virulence genes were present among the isolated serovars. This study highlights the importance of continuous monitoring and surveillance for pathogenic Salmonella and their potential risks to both humans and animals.

Clinical profile, outcomes, and progression to type 2 diabetes among Indian women with gestational diabetes mellitus seen at a diabetes center in south India.

AIM: To describe the clinical profile, maternal and fetal outcomes, and the conversion rates to diabetes in women with gestational diabetes mellitus (GDM) seen at a tertiary care diabetes center in urban south India. MATERIALS AND METHODS: Clinical case records of 898 women with GDM seen between 1991 and 2011 were extracted from the Diabetes Electronic Medical Records (DEMR) of a tertiary care diabetes center in Chennai, south India and their clinical profile was analyzed. Follow-up data of 174 GDM women was available. To determine the conversion rates to diabetes, oral glucose tolerance test (OGTT) was done in these women. Glucose tolerance status postpartum was classified based on World Health Organization (WHO) 2006 criteria. RESULTS: The mean maternal age of the women was 29 ± 4 years and mean age of gestation at first visit were 24 ± 8.4 weeks. Seventy percent of the women had a family history of diabetes. Seventy-eight percent of the women delivered full-term babies and 65% underwent a cesarean section. The average weight gain during pregnancy was 10.0 ± 4.2 kg. Macrosomia was present in 17.9% of the babies, hypoglycemia in 10.4%, congenital anomalies in 4.3%, and the neonatal mortality rate was 1.9%. Mean follow-up duration of the 174 women of whom outcome data was available was 4.5 years. Out of the 174, 101 women who were followed-up developed diabetes, of whom half developed diabetes within 5 years and over 90%, within 10 years of the delivery. CONCLUSIONS: Progression to type 2 diabetes mellitus (T2DM) in Indian women with GDM is rapid. There is an urgent need to develop standardized protocols for GDM care in India that can improve the maternal and fetal outcomes and help prevent future diabetes in women with GDM.

Engineering a high throughput axon injury system.

Several key biological mechanisms of traumatic injury to axons have been elucidated using in vitro stretch injury models. These models, however, are based on the experimentation of single cultures keeping productivity slow. Indeed, low yield has hindered important and well-founded investigations requiring high throughput methods such as proteomic analyses. To meet this need, we engineered a multi-well high throughput injury device to accelerate and accommodate the next generation of traumatic brain injury research. This modular system stretch injures neuronal cultures in either a 24-well culture plate format or 6 individual wells simultaneously. Custom software control allows the user to accurately program the pressure pulse parameters to achieve the desired substrate deformation and injury parameters. Analysis of the pressure waveforms showed that peak pressure was linearly related to input pressure and valve open times and that the 6- and 24-well modules displayed rise times, peak pressures, and decays with extremely small standard deviations. Data also confirmed that the pressure pulse was distributed evenly throughout the pressure chambers and therefore to each injury well. Importantly, the relationship between substrate deformation and applied pressure was consistent among the multiple wells and displayed a predictable linear behavior in each module. These data confirm that this multi-well system performs as well as currently used stretch injury devices and can undertake high throughput studies that are needed across the field of neurotrauma research.