Effectiveness of mHealth Interventions for Monitoring Antenatal Care among Pregnant Women in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis.

Antenatal care (ANC) is essential in maternal and child health since it provides care to pregnant women from conception through to labour in order to ensure a safe pregnancy and childbirth. In recent years, mobile health (mHealth) interventions have emerged as a promising solution to improve maternal and child health outcomes in low- and middle-income countries (LMICs). The present study aimed to conduct a systematic review and meta-analysis of trials to evaluate the effectiveness of mHealth interventions to monitor prenatal care among pregnant women in LMICs. A systematic literature review was conducted using the databases CINHAL, Embase, MEDLINE, and PsycINFO on the effectiveness of mHealth interventions in monitoring the antenatal care of pregnant women. The study selection, data extraction of the included articles, and quality appraisal were assessed. Our study included six studies considering 7886 participants. All articles were from low- and middle-income countries (LMICs). Antenatal mothers who used a mobile health intervention were more likely (RR = 1.66, 95%CI = 1.07-2.58, I2 = 98%) to attend ANC check-ups when compared with the women who did not use any mobile health applications or did not receive any short message services. mHealth technologies are being utilised more and more to increase care accessibility and improve maternal and fetal health. Policymakers should prioritise the integration of mHealth interventions into maternal healthcare services in LMICs, ensuring that they are cost-effective, accessible, and sustainable and that healthcare workers are trained to deliver these interventions effectively.

Out-of-pocket expenditure and its correlates for institutional deliveries in private and public healthcare sectors in India: findings from NFHS 5.

BACKGROUND: Increased coverage for institutional delivery (ID) is one of the essential factors for improved maternal and child health (MCH). Though, ID increased over time, out-of-pocket expenditure (OOPE) for the care-seeking families had been found to be growing, parallelly. Hence, we estimated OOPE in public and private health centres for ID, along with their sources and attributing factors and compared state and union territory-wise, so that financial risk protection can be improved for MCH related services. METHODS: We used women's data from the National Family Health Survey, 2019-2021 (NFHS-5). Reproductive aged women (15-49 years) delivering one live child in last 5 years (n = 145,386) in any public or private institutions, were included. Descriptive statistics were presented as frequency and proportions. OOPE, was summarized as median and interquartile range (IQR). To estimate the extent for each covariate's effect, linear regression model was conducted. RESULTS: Overall median OOPE for ID was Rs. 4066 (median OOPE: private hospitals: Rs.25600, public hospitals: Rs.2067). Health insurance was not sufficient to slash OOPE down at private facilities. Factors associated significantly to high OOPE were mothers' education, elderly pregnancy, complicated delivery, birth order of the latest child etc. CONCLUSION: A standard norm for ID should be implemented as a component of overseeing and controlling inequality. Aiding the needy is probably just one side of the solution, while the focus is required to be shifted towards reducing disparity among the health facilities, so that the beneficiaries do not need to spend on essential services or during emergencies.

The association of asthma and air pollution: Evidence from India.

In the last two decades, air pollution has increased throughout India resulting in the deterioration of air quality. This paper estimates the prevalence of self-reported asthma in women aged 15-49 years and examines the link between outdoor air pollution and disease prevalence in India by combining satellite data on particulate matter (PM2.5) and the National Family Health Survey (NFHS-4), 2015-16. The results indicate that both indoor pollution as well as outdoor air pollution are important risk factors for asthma in women as both independently increase the probability of asthma among this group. Strategies around the prevention of asthma need to recognize the role of both indoor as well as outdoor air pollution. The other significant risk factors for asthma are smoking, second-hand smoking, type of diet and obesity.

Prevalence and correlates of low birth weight in India: findings from national family health survey 5.

BACKGROUND: Childhood mortality and morbidity has become a major public health issue in low-middle-income countries. However, evidence suggested that Low birth weight(LBW) is one of the most important risk factors for childhood deaths and disability.This study is designed to estimate the prevalence of low birth weight (LBW) in India and to identify maternal correlates associated with LBW. METHODS: Data has been taken from National Family Health Survey 5 (2019-2021) for analysis. 149,279 women belonging to reproductive age group (15-49) year who had last recent most delivery preceding the NFHS-5 survey. RESULTS: Mother's age, female child, birth interval of less than 24 months, their low educational level, low wealth index, rural residence, lack of insurance coverage, women with low BMI, anaemia, and no ANC visits during pregnancy are predictors that contribute to LBW in India. After adjusting for covariates, smoking and alcohol consupmtion is strongly correlated with LBW. CONCLUSION: Mother's age, educational attainment and socioeconomic status of living has a highly significant with LBW in India. However, consumption of tobacco and cigarrettes are also associated with LBW.

Disparities in Coverage of Adult Immunization among Older Adults in India.

A lack of a universal adult immunization scheme in India poses a challenge to achieve universal health coverage. Healthcare disparity is one of the biggest challenges in low- and middle-income countries such as India. We aimed to estimate the disparities in coverage of various adult vaccines among older adults in India using nationally representative data. An observational analysis among 31,464 participants aged ≥60 years from the Longitudinal Ageing Study in India, 2017-2018, was conducted. Vaccination coverage across wealth quintiles and selected non-communicable diseases were reported as frequencies and weighted proportions along with their 95% confidence intervals as a measure of uncertainty. The highest coverage was of the diphtheria and tetanus vaccine (2.75%) followed by typhoid (1.84%), hepatitis B (1.82%), influenza (1.59%), and pneumococcal (0.74%). The most affluent groups had a higher coverage of all vaccines. Participants having high cholesterol, psychiatric conditions, and cancer had the highest coverage of all vaccines. Overall, a very low coverage of all vaccines was observed. The coverage was influenced by social determinants of health, depicting a disparity in accessing immunization. Hence, at-risk groups such as the deprived and multimorbid patients need to be covered under the ambit of free immunization to achieve universal health coverage.

Histological Spectrum of Post Covid Debridement Tissues: Salient Histomorphological Features With Respect to Identification Fungal Elements.

Background: Secondary bacterial and fungal infections in COVID patients have been documented during current pandemic. The present study provides detailed account of histomorphology of debridement tissue received for suspected fungal infections. The primary objective was to determine the morphological characteristics that must be recognized for the identification of fungal hyphae. Methods: The detailed histological examination of debridement tissue was performed. Demographic and clinical findings with treatment provided was recorded. Presence or absence of necrosis and lecocytoclasis was noted. Results: A total of 110 cases of debrided tissues were included in the study. Eosinophilic granular necrosis with lecocytoclasis was observed in 103cases; fungal elements were identified in 89.3% (92/103) of these. Eleven cases where necrosis was observed, strong suspicion of fungus was reported, 6 of them displayed fungus on KOH preparation, 3 on repeat biopsy. However, in 2 of these cases, neither KOH nor repeat biopsies identified the fungus. Mucor with aspergillus was observed in 7 cases and actinomyces in 3. In all these 10 cases dense fungal colonies were evident. In 7 cases careful observation revealed fruiting bodies of aspergillus. Cotton ball appearance of actinomyces was evident. Mucor infection in current disease was so rampant that aseptate ribbon like branching mucor hyphae were evident on H&E sections. Diabetes was significantly associated with fungal infection (97.2%; 70/72; P < .005). 90% [19/21] of the patients who were on room air and diagnosed with fungal infection were diabetic. Conclusions: Eosinophilic granular necrosis with the presence of neutrophilic debris in a case of suspected fungal disease suggests the presence of fungal elements. This warrants processing of the entire tissue deposited for examination, careful observation, application of fungal stains, and repeat biopsy if clinical suspicion is strong. Moreover, uncontrolled diabetes is more frequently associated with secondary fungal infection in COVID patients as compared to oxygen therapy.

Nano-Messengers of the Heart: Promising Theranostic Candidates for Cardiovascular Maladies.

Till date, cardiovascular diseases remain a leading cause of morbidity and mortality across the globe. Several commonly used treatment methods are unable to offer safety from future complications and longevity to the patients. Therefore, better and more effective treatment measures are needed. A potential cutting-edge technology comprises stem cell-derived exosomes. These nanobodies secreted by cells are intended to transfer molecular cargo to other cells for the establishment of intercellular communication and homeostasis. They carry DNA, RNA, lipids, and proteins; many of these molecules are of diagnostic and therapeutic potential. Several stem cell exosomal derivatives have been found to mimic the cardioprotective attributes of their parent stem cells, thus holding the potential to act analogous to stem cell therapies. Their translational value remains high as they have minimal immunogenicity, toxicity, and teratogenicity. The current review highlights the potential of various stem cell exosomes in cardiac repair, emphasizing the recent advancements made in the development of cell-free therapeutics, particularly as biomarkers and as carriers of therapeutic molecules. With the use of genetic engineering and biomimetics, the field of exosome research for heart treatment is expected to solve various theranostic requirements in the field paving its way to the clinics.

Gastric immature teratoma arising from the lesser curvature of the stomach: A rare case report.

Immature gastric teratoma is an uncommon germ cell tumor of the stomach. A 6-month-old male child was born through full-term vaginal delivery. After 1 month presented with a history of abdominal distension and palpable mass along with a history of Malena for the past 10 days. Computed tomography scan showed the presence of a large well-defined multilobulated solid cystic lesion with multiple calcifications in the abdominopelvic region. Radiological findings were suggestive of germ cell tumors. The exploratory laparotomy findings showed a large tumor mass with variegated consistency arising from the lesser curvature of the posterior wall of the stomach. The total excision of mass and primary closure of the gastric wall was done. Histopathology of excised specimens showed immature teratoma of the stomach. The child is still on follow-up regularly visited as outpatient, doing well day-to-day activity. We report a very rare case of immature gastric teratoma in an infant on the basis of clinicoradiological and pathological findings.

Cost-Effectiveness of antiretroviral therapy: A systematic review.

BACKGROUND: The mobilization of resources to prevent and treat human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) is unparalleled in the history of public health. The uptake of antiretroviral therapy (ART) has been rapid and unprecedented and made possible by the availability of funding - external and domestic. To justify continuous funding of ART in resource-scarce settings, a spate of cost-effectiveness studies has been undertaken in a number of countries. This paper is based on a systematic review of global studies on cost-effectiveness analysis of ART. OBJECTIVES: The major objective was to review the existing literature on cost-effectiveness of ART to determine whether ART has been cost-effective (CE) in different settings. METHODS: We searched PubMed and Google Scholar for articles published between 2008 and 2017. We included studies that measured costs as well as effectiveness of HIV treatment - specifically ART - using incremental cost-effectiveness ratio as one of the outcomes. RESULTS: We identified 15 studies that met the search criteria for inclusion in the systematic review. The review confirms that ART programs have been CE across different settings, contexts, and strategies. CONCLUSION: The review would be useful for countries that are straining to raise funds for the health sector, generally, and for AIDS prevention and control program, specifically. This would also be beneficial for carrying out similar studies, if necessary, and as an advocacy tool for garnering additional funding.

The M Protein of Streptococcus pyogenes Strain AP53 Retains Cell Surface Functional Plasminogen Binding after Inactivation of the Sortase A Gene.

Streptococcus pyogenes (Lancefield group A Streptococcus [GAS]) is a ß-hemolytic human-selective pathogen that is responsible for a large number of morbid and mortal infections in humans. For efficient infection, GAS requires different types of surface proteins that provide various mechanisms for evading human innate immune responses, thus enhancing pathogenicity of the bacteria. Many such virulence-promoting proteins, including the major surface signature M protein, are translocated after biosynthesis through the cytoplasmic membrane and temporarily tethered to this membrane via a type 1 transmembrane domain (TMD) positioned near the COOH terminus. In these proteins, a sorting signal, LPXTG, is positioned immediately upstream of the TMD, which is cleaved by the membrane-associated transpeptidase, sortase A (SrtA), leading to the covalent anchoring of these proteins to newly emerging l-Ala-l-Ala cross-bridges of the growing peptidoglycan cell wall. Herein, we show that inactivation of the srtA gene in a skin-tropic pattern D GAS strain (AP53) results in retention of the M protein in the cell membrane. However, while the isogenic AP53 ΔsrtA strain is attenuated in overall pathogenic properties due to effects on the integrity of the cell membrane, our data show that the M protein nonetheless can extend from the cytoplasmic membrane through the cell wall and then to the surface of the bacteria and thereby retain its important properties of productively binding and activating fluid-phase host plasminogen (hPg). The studies presented herein demonstrate an underappreciated additional mechanism of cell surface display of bacterial virulence proteins via their retention in the cell membrane and extension to the GAS surface.IMPORTANCE Group A Streptococcus pyogenes (GAS) is a human-specific pathogen that produces many surface factors, including its signature M protein, that contribute to its pathogenicity. M proteins undergo specific membrane localization and anchoring to the cell wall via the transpeptidase sortase A. Herein, we explored the role of sortase A function on M protein localization, architecture, and function, employing, a skin-tropic GAS isolate, AP53, which expresses a human plasminogen (hPg)-binding M (PAM) Protein. We showed that PAM anchored in the cell membrane, due to the targeted inactivation of sortase A, was nonetheless exposed on the cell surface and functionally interacted with host hPg. We demonstrate that M proteins, and possibly other sortase A-processed proteins that are retained in the cell membrane, can still function to initiate pathogenic processes by this underappreciated mechanism.

Solution structural model of the complex of the binding regions of human plasminogen with its M-protein receptor from Streptococcus pyogenes.

VEK50 is a truncated peptide from a Streptococcal pyogenes surface human plasminogen (hPg) binding M-protein (PAM). VEK50 contains the full A-domain of PAM, which is responsible for its low nanomolar binding to hPg. The interaction of VEK50 with kringle 2, the PAM-binding domain in hPg (K2hPg), has been studied by high-resolution NMR spectroscopy. The data show that each VEK50 monomer in solution contains two tight binding sites for K2hPg, one each in the a1- (RH1; R17H18) and a2- (RH2; R30H31) repeats within the A-domain of VEK50. Two mutant forms of VEK50, viz., VEK50[RH1/AA] (VEK50ΔRH1) and VEK50[RH2/AA] (VEK50ΔRH2), were designed by replacing each RH with AA, thus eliminating one of the K2hPg binding sites within VEK50, and allowing separate study of each binding site. Using 13C- and 15N-labeled peptides, NMR-derived solution structures of VEK50 in its complex with K2hPg were solved. We conclude that the A-domain of PAM can accommodate two molecules of K2hPg docked within a short distance of each other, and the strength of the binding is slightly different for each site. The solution structure of the VEK50/K2hPg, complex, which is a reductionist model of the PAM/hPg complex, provides insights for the binding mechanism of PAM to a host protein, a process that is critical to S. pyogenes virulence.

Computational and mutational analysis of TatD DNase of Bacillus anthracis.

The role of TatD DNases as DNA repair enzymes or cell death (apoptotic) nucleases is well established in prokaryotes as well as eukaryotes. The current study aims to characterize the TatD nuclease from Bacillus anthracis (Ba TatD) and to explore its key histidine catalytic residues. Ba TatD was found to be a metal-dependent, nonspecific endonuclease which could efficiently cleave double-stranded DNA substrates. Moreover, Ba TatD nuclease was observed to be thermostable up to 55°C and act in a wide pH range indicating its industrial applicability. Diethyl pyrocarbonate-based histidine-selective alkylation of the Ba TatD resulted in a loss of its nuclease activity suggesting a crucial role of the histidine residues in its activity. The key residues of Ba TatD were predicted using sequence analysis and structure-based approaches, and then the predicted residues were further tested by mutational analysis. Upon mutational analysis, H128 and H153 have been found to be crucial for Ba TatD activity, though H153 seems to bear an important but a dispensable role for the Ba TatD nuclease. Ba TatD had a uniform expression in the cytosol of B. anthracis, which indicates a significant role of the protein in the pathogen's life cycle. This is the first study to identify and characterize the TatD DNase from B. anthracis and will be helpful in gaining more insights on the role of TatD proteins in Gram-positive bacteria where it remains unexplored.

A combined subunit vaccine comprising BP26, Omp25 and L7/L12 against brucellosis.

The current vaccines against brucellosis, namely Brucella abortus strains 19 and RB51, prevent infection in animals but pose potential risks like virulence and attenuation reversal. In this milieu, although subunit vaccination using a single potent immunogen of B. abortus, e.g. BP26 or Omp25 or L7/L12 etc., appears as a safer alternative, nonetheless it confers inadequate protection against the zoonosis compared to attenuated vaccines. Hence, we have investigated the prophylactic potential of a combined subunit vaccine (CSV) comprising the BP26, Omp25 and L7/L12 antigens of B. abortus, in mice model. Sera obtained from CSV immunized mice groups showed heightened IgG titers against all the three components and exhibited specificity upon immunoblotting, reiterating their authenticity. Further, the IgG1/IgG2a ratio obtained against each antigen revealed a predominant Th2 immune response in CSV immunized mice group. However, on assessing the levels of Th1-dependent (IFN-γ and TNF-α) and Th2-dependent (IL-4 and IL-10) cytokines in different formulations, prominent IFN-γ levels were elicited in CSV immunized mice. Further, upon infection with virulent B. abortus 544, the combined subunit vaccinated mice displayed superior degree of protection (Log10 reduction) than the individual vaccines; however, B. abortus S19 showed the highest protection. Altogether, this study suggests that co-immunization of three B. abortus immunogens as a CSV complements and triggers a mixed Th1/Th2 immune response leading to superior degree of protection against pathogenic B. abortus 544 infection.

A study to identify the practices of the buffalo keepers which inadvertently lead to the spread of brucellosis in Delhi.

BACKGROUND: India has the largest Buffalo population in the world, with every household in rural India owning buffaloes depending upon daily milk requirement - dairy farmers can own between 10 to 70 buffaloes. The health of Indian buffaloes is of economic importance since India is one of the largest buffalo meat exporters in the world, and Indian Buffalo semen is sold in the USA for breeding purposes. However, National Control Program on brucellosis is only active in South India and in Panjab (a North Indian state with high human brucellosis incidence). Our aim was to assess the knowledge and practices of the buffalo keepers of Delhi that make them susceptible to brucellosis. RESULTS: Amongst all the 11 districts of Delhi, there was 0% awareness about brucellosis and also about the S19 vaccine as the buffalo keepers had never heard of S19 vaccine which is available at minimal cost from Indian Veterinary Research Institute, Bareilly, India. Majority of the respondents drink raw milk, sleep in cattle sheds, do not isolate sick cattle, do not test buffaloes blood for any disease before purchasing them, apply intrauterine medication with bare hands to buffalo after abortion of foetus, never clean their cattle sheds with a disinfectant and believe that they can only acquire skin infections from cattle. All of these habits make them prone to brucellosis. While about 20 to 27% of respondents reported a history of abortions and retained placenta, disposed of the placenta with bare hands, and applied raw milk on cracked lips. It was surprising to note that majority of them never reared small ruminants like sheep and goat with buffaloes or Bos species as they were aware of the rapid spread of disease from small to big ruminants. CONCLUSIONS: We found that buffalo keepers were ignorant of brucellosis, its causative agent, relevant vaccines and that they also involved in high-risk activities. As such, our findings highlight a need for buffalo keepers to be better educated via several awareness camps to minimize human exposure to Brucella in Delhi.

Exploring the interaction between Mycobacterium tuberculosis enolase and human plasminogen using computational methods and experimental techniques.

Surface localized microbial enolases' binding with human plasminogen has been increasingly proven to have an important role in initial infection cycle of several human pathogens. Likewise, surface localized Mycobacterium tuberculosis (Mtb) enolase also binds to human plasminogen, and this interaction may entail crucial consequences for granuloma stability. The current study is the first attempt to explore the plasminogen interacting residues of enolase from Mtb. Beginning with the structural modeling of Mtb enolase, the binding pose of Mtb enolase and human plasminogen was predicted using protein-protein docking simulations. The binding pose revealed the interface region with interacting residues and molecular interactions. Next, the interacting residues were refined and ranked by using various criteria. Finally, the selected interacting residues were tested experimentally for their involvement in plasminogen binding. The two consecutive lysine residues, Lys-193 and Lys-194, turned out to be active residues for plasminogen binding. These residues when substituted for alanine along with the most active residue Lys-429, that is, the triple mutant (K193A + K194A + K429A) Mtb enolase, exhibited 40% reduction in plasminogen binding. It is worth noting that Mtb enolase lost nearly half of the plasminogen binding activity with only three simultaneous substitutions, without any significant secondary structure perturbation. Further, the sequence comparison between Mtb and human enolase isoforms suggests the possibility of selective targeting of Mtb enolase to obstruct binding of human plasminogen.

Functional characterization of PhoPR two component system and its implication in regulating phosphate homeostasis in Bacillus anthracis.

BACKGROUND: Recent report on importance of phosphate starvation (PS) in Bacillus anthracis (BA) pathogenesis warrants further investigation of the underlying regulatory mechanism. Potential role of PhoPR two component system (TCS) in phosphate homeostasis and virulence of several pathogens necessitates the study of annotated PhoPR in BA. METHODS: Expression of phoP and phoR was analyzed using qRT-PCR. PhoPR was characterized biochemically. DNA-protein interaction was analyzed by EMSA. Docking was done to predict PhoPR interacting residues with further validation by mutational studies. pHCMC05 was used to overexpress PhoP in BA. RESULTS: In silico analysis revealed Bas4483-4484, as putative PhoR-PhoP. Their expression was decreased with increasing phosphate concentration reflecting some role in PS. Both PhoP (response regulator) and PhoR (histidine kinase) showed characteristic property of TCS i.e., autophosphorylation and phosphotransfer. PhoR showed both kinase and phosphatase activity. PhoP bound with promoter of PS marker genes. In silico and in vitro analysis revealed role of PhoRH370 and PhoPD10, PhoPD53, PhoPM55 in PhoPR interaction. Challenge studies showed decreased survival of mice infected with BApHCMC05-PhoP. CONCLUSION: This study affirms that PhoPR forms functional TCS which is upregulated under PS. PhoP binding with promoter of PS marker genes indicates its possible role in regulating PS response. Low survival of mice infected with BApHCMC05-PhoP suggests its role in BA virulence. GENERAL SIGNIFICANCE: Considering the significance of PS in BA infection, possible role of PhoPR in its regulation and exclusive presence of TCS in prokaryotes, PhoP can be proposed as potential drug target against anthrax.

Identification of Novel Raft Marker Protein, FlotP in Bacillus anthracis.

Lipid rafts are dynamic, nanoscale assemblies of specific proteins and lipids, distributed heterogeneously on eukaryotic membrane. Flotillin-1, a conserved eukaryotic raft marker protein (RMP) harbor SPFH (Stomatin, Prohibitin, Flotillin, and HflK/C) and oligomerization domains to regulate various cellular processes through its interactions with other signaling or transport proteins. Rafts were thought to be absent in prokaryotes hitherto, but recent report of its presence and significance in physiology of Bacillus subtilis prompted us to investigate the same in pathogenic bacteria (PB) also. In prokaryotes, proteins of SPFH2a subfamily show highest identity to SPFH domain of Flotillin-1. Moreover, bacterial genome organization revealed that Flotillin homolog harboring SPFH2a domain exists in an operon with an upstream gene containing NFeD domain. Here, presence of RMP in PB was initially investigated in silico by analyzing the presence of SPFH2a, oligomerization domains in the concerned gene and NfeD domain in the adjacent upstream gene. After investigating 300 PB, four were found to harbor RMP. Among them, domains of Bas0525 (FlotP) of Bacillus anthracis (BA) showed highest identity with characteristic domains of RMP. Considering the global threat of BA as the bioterror agent, it was selected as a model for further in vitro characterization of rafts in PB. In silico and in vitro analysis showed significant similarity of FlotP with numerous attributes of Flotillin-1. Its punctate distribution on membrane with exclusive localization in detergent resistant membrane fraction; strongly favors presence of raft with RMP FlotP in BA. Furthermore, significant effect of Zaragozic acid (ZA), a raft associated lipid biosynthesis inhibitor, on several patho-physiological attributes of BA such as growth, morphology, membrane rigidity etc., were also observed. Specifically, a considerable decrease in membrane rigidity, strongly recommended presence of an unknown raft associated lipid molecule on membrane of BA. In addition, treatment with ZA decreased secretion of anthrax toxins and FlotP expression, suggesting potential role of raft in pathogenesis and physiology of BA. Thus, the present study not only suggest the existence and role of raft like entity in pathophysiology of BA but also its possible use for the development of novel drugs or vaccines against anthrax.

PLGA (85:15) nanoparticle based delivery of rL7/L12 ribosomal protein in mice protects against Brucella abortus 544 infection: A promising alternate to traditional adjuvants.

There is a compelling need for the development of suitable adjuvants for human use to enhance the efficacy of the upcoming vaccines for the prevention of life threatening infections. In the current study, we have tried to explore the immunogenic potential of nanoparticles (NPs) made of PLGA (poly lactic-co-glycolic acid), a biodegradable and biocompatible polymer approved by FDA for human use after entrapping rL7/L12 protein, an immunodominant antigen of Brucella. Adjuvant properties were exhibited by the formulation as it elicited high IgG antibody titers just after first immunization which increased significantly after the booster administration. A good elicitation of the Th1 cytokines especially IFN-γ was recorded. Amongst the IgG antibody subclasses, IgG1 remained the predominant subclass to be elicited in mice serum after immunization; however IgG1/2a ratio showed a mixed profile of Th1/Th2 response. Lymphocyte proliferation assay as a marker of amplification in cellular immunity demonstrated that the splenocytes of the immunized mice had a high proliferation index with reference to the control, revealing that L7/L12 entrapping PLGA nanoparticles are potent inducer of inflammatory cell response indispensable to combat Brucella infection. Enumeration of splenic CFU after 14 days of infection with Brucella abortus 544 showed a significant reduction in log CFU of splenic bacteria in the vaccinated mice as compared to the control group. Therefore it is evident that PLGA nano formulations delivering the entrapped vaccine candidate in mice elicit specific humoral as well as cellular responses specific to the entrapped Brucella antigen. So there is much promise in this approach and this work by highlighting the adjuvant properties of the PLGA nanospheres will accelerate the development of improved vaccines safe for human as well as veterinary use.

Recombinant L7/L12 protein entrapping PLGA (poly lactide-co-glycolide) micro particles protect BALB/c mice against the virulent B. abortus 544 infection.

Brucella abortus is the etiologic agent of Brucellosis, a zoonotic infection affecting a wide range of animals. It is a highly infectious disease of pandemic potential reporting over 500,000 new human cases annually. Till date, there is no reported vaccine for humans and the available animal vaccines are unsafe, therefore a safe and effective subunit vaccine is highly sought for. In this study, we have evaluated rL7/L12 protein encapsulated in microparticles of PLGA (85:15), a biocompatible and biodegradable polymer approved by FDA for human use. In this work, BALB/c mice have been immunized with rL7/L12 entrapped in microparticles in a prime-boost regimen. Further, evaluation of the immunogenicity of the formulation showed that the IgG antibody titre reached a maxima of 2.2×10(5) (p value 0.0001 v/s control) after the injection of the booster dose. A mixed IgG isotype profile (IgG1/IgG2a) indicated the stimulation of both the cellular as well as humoral immunity which has increased parallely and gradually since the first immunization. High levels of IFN-γ, 815±55pg/ml were recorded depicting an optimal elicitation of the cellular wing of immunity leading to clearance of splenic bacteria upto 1.69 log units.