Advances in the targeted theragnostics of osteomyelitis caused by Staphylococcus aureus.

Bone infections caused by Staphylococcus aureus may lead to an inflammatory condition called osteomyelitis, which results in progressive bone loss. Biofilm formation, intracellular survival, and the ability of S. aureus to evade the immune response result in recurrent and persistent infections that present significant challenges in treating osteomyelitis. Moreover, people with diabetes are prone to osteomyelitis due to their compromised immune system, and in life-threatening cases, this may lead to amputation of the affected limbs. In most cases, bone infections are localized; thus, early detection and targeted therapy may prove fruitful in treating S. aureus-related bone infections and preventing the spread of the infection. Specific S. aureus components or overexpressed tissue biomarkers in bone infections could be targeted to deliver active therapeutics, thereby reducing drug dosage and systemic toxicity. Compounds like peptides and antibodies can specifically bind to S. aureus or overexpressed disease markers and combining these with therapeutics or imaging agents can facilitate targeted delivery to the site of infection. The effectiveness of photodynamic therapy and hyperthermia therapy can be increased by the addition of targeting molecules to these therapies enabling site-specific therapy delivery. Strategies like host-directed therapy focus on modulating the host immune mechanisms or signaling pathways utilized by S. aureus for therapeutic efficacy. Targeted therapeutic strategies in conjunction with standard surgical care could be potential treatment strategies for S. aureus-associated osteomyelitis to overcome antibiotic resistance and disease recurrence. This review paper presents information about the targeting strategies and agents for the therapy and diagnostic imaging of S. aureus bone infections.

The MT1 receptor as the target of ramelteon neuroprotection in ischemic stroke.

Stroke is the leading cause of death and disability worldwide. Novel and effective therapies for ischemic stroke are urgently needed. Here, we report that melatonin receptor 1A (MT1) agonist ramelteon is a neuroprotective drug candidate as demonstrated by comprehensive experimental models of ischemic stroke, including a middle cerebral artery occlusion (MCAO) mouse model of cerebral ischemia in vivo, organotypic hippocampal slice cultures ex vivo, and cultured neurons in vitro; the neuroprotective effects of ramelteon are diminished in MT1-knockout (KO) mice and MT1-KO cultured neurons. For the first time, we report that the MT1 receptor is significantly depleted in the brain of MCAO mice, and ramelteon treatment significantly recovers the brain MT1 losses in MCAO mice, which is further explained by the Connectivity Map L1000 bioinformatic analysis that shows gene-expression signatures of MCAO mice are negatively connected to melatonin receptor agonist like Ramelteon. We demonstrate that ramelteon improves the cerebral blood flow signals in ischemic stroke that is potentially mediated, at least, partly by mechanisms of activating endothelial nitric oxide synthase. Our results also show that the neuroprotection of ramelteon counteracts reactive oxygen species-induced oxidative stress and activates the nuclear factor erythroid 2-related factor 2/heme oxygenase-1 pathway. Ramelteon inhibits the mitochondrial and autophagic death pathways in MCAO mice and cultured neurons, consistent with gene set enrichment analysis from a bioinformatics perspective angle. Our data suggest that Ramelteon is a potential neuroprotective drug candidate, and MT1 is the neuroprotective target for ischemic stroke, which provides new insights into stroke therapy. MT1-KO mice and cultured neurons may provide animal and cellular models of accelerated ischemic damage and neuronal cell death.

Effect of sacubitril-valsartan on the incidence of atrial fibrillation: A meta-analysis.

INTRODUCTION: Sacubitril/valsartan reduces all-cause mortality in heart failure (HF) patients compared to angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs). ACEIs/ARBs have been shown to decrease the incidence of atrial fibrillation (AF). We hypothesized sacubitril-valsartan decreases the incidence of AF compared to ACEis/ARBs. METHODS: Clinicaltrials.gov was searched for trials by terms sacubitril/valsartan, entresto, sacubitril, valsartan. Randomized controlled human trials of sacubitril/valsartan reporting AF were included. Data were extracted independently by two reviewers. Data was pooled using a random effect model. Publication bias was evaluated by funnel plots. RESULTS: A total of 11 trials including 11,458 patients on sacubitril/valsartan and 10,128 patients on ACEI/ARBs were identified. A total of 284 AF events were reported in the sacubitril/valsartan group compared to 256 AF events in ACEIs/ARBs. Patients on sacubitril/valsartan were as likely as patients on ACEIs/ARBs to develop AF (pooled odds ratio [OR] = 1.091, 95% confidence interval [CI] = 0.917-1.298, p = .324). Six atrial flutter (AFl) events were reported in six trials; 48 out of 9165 patients in the sacubitril/valsartan group developed AFl compared to 46 out of 8759 in ACEi/ARBs group. There was no difference in AFl risk between the two groups (pooled OR = 1.028, 95% CI = 0.681-1.553, p = .894). Finally, sacubitril/valsartan did not reduce the risk of atrial arrhythmias (AF + AFl) compared to ACEi/ARBs (pooled OR = 1.081, 95% CI = 0.922-1.269, p = .337). CONCLUSION: Although sacubitril/valsartan reduces mortality compared to ACEIs/ARBs in HF patients, they do not reduce AF risk compared to these drugs.

Gut microbiota analyses of Saudi populations for type 2 diabetes-related phenotypes reveals significant association.

BACKGROUND: Large-scale gut microbiome sequencing has revealed key links between microbiome dysfunction and metabolic diseases such as type 2 diabetes (T2D). To date, these efforts have largely focused on Western populations, with few studies assessing T2D microbiota associations in Middle Eastern communities where T2D prevalence is now over 20%. We analyzed the composition of stool 16S rRNA from 461 T2D and 119 non-T2D participants from the Eastern Province of Saudi Arabia. We quantified the abundance of microbial communities to examine any significant differences between subpopulations of samples based on diabetes status and glucose level. RESULTS: In this study we performed the largest microbiome study ever conducted in Saudi Arabia, as well as the first-ever characterization of gut microbiota T2D versus non-T2D in this population. We observed overall positive enrichment within diabetics compared to healthy individuals and amongst diabetic participants; those with high glucose levels exhibited slightly more positive enrichment compared to those at lower risk of fasting hyperglycemia. In particular, the genus Firmicutes was upregulated in diabetic individuals compared to non-diabetic individuals, and T2D was associated with an elevated Firmicutes/Bacteroidetes ratio, consistent with previous findings. CONCLUSION: Based on diabetes status and glucose levels of Saudi participants, relatively stable differences in stool composition were perceived by differential abundance and alpha diversity measures. However, community level differences are evident in the Saudi population between T2D and non-T2D individuals, and diversity patterns appear to vary from well-characterized microbiota from Western cohorts. Comparing overlapping and varying patterns in gut microbiota with other studies is critical to assessing novel treatment options in light of a rapidly growing T2D health epidemic in the region. As a rapidly emerging chronic condition in Saudi Arabia and the Middle East, T2D burdens have grown more quickly and affect larger proportions of the population than any other global region, making a regional reference T2D-microbiome dataset critical to understanding the nuances of disease development on a global scale.

Genetic diversity of Plasmodium falciparum AMA-1 antigen from the Northeast Indian state of Tripura and comparison with global sequences: implications for vaccine development.

BACKGROUND: Malaria continues to be a major public health problem in the Northeastern part of India despite the implementation of vector control measures and changes in drug policies. To develop successful vaccines against malaria, it is important to assess the diversity of vaccine candidate antigens in field isolates. This study was done to assess the diversity of Plasmodium falciparum AMA-1 vaccine candidate antigen in a malaria-endemic region of Tripura in Northeast India and compare it with previously reported global isolates with a view to assess the feasibility of developing a universal vaccine based on this antigen. METHODS: Patients with fever and malaria-like illness were screened for malaria and P. falciparum positive cases were recruited for the current study. The diversity of PfAMA-1 vaccine candidate antigen was evaluated by nested PCR and RFLP. A selected number of samples were sequenced using the Sanger technique. RESULTS: Among 56 P. falciparum positive isolates, Pfama-1 was successfully amplified in 75% (n = 42) isolates. Allele frequencies of PfAMA-1 antigen were 16.6% (n = 7) for 3D7 allele and 33.3% (n = 14) in both K1 and HB3 alleles. DNA sequencing revealed 13 haplotypes in the Pfama-1 gene including three unique haplotypes not reported earlier. No unique amino-acid substitutions were found. Global analysis with 2761 sequences revealed 435 haplotypes with a very complex network composition and few clusters. Nucleotide diversity for Tripura (0.02582 ± 0.00160) showed concordance with South-East Asian isolates while recombination parameter (Rm = 8) was lower than previous reports from India. Population genetic structure showed moderate differentiation. CONCLUSIONS: Besides documenting all previously reported allelic forms of the vaccine candidate PfAMA-1 antigen of P. falciparum, new haplotypes not reported earlier, were found in Tripura. Neutrality tests indicate that the Pfama-1 population in Tripura is under balancing selection. This is consistent with global patterns. However, the high haplotype diversity observed in the global Pfama-1 network analysis indicates that designing a universal vaccine based on this antigen may be difficult. This information adds to the existing database of genetic diversity of field isolates of P. falciparum and may be helpful in the development of more effective vaccines against the parasite.

Incidence of HPVs, EBV, and MMTV-Like Virus in Breast Cancer in Qatar.

INTRODUCTION: Human papillomaviruses (HPVs), Epstein-Barr virus (EBV), and mouse mammary tumor virus-like virus (MMTV-like virus) can be present and contribute to breast cancer development and progression. However, the role of these oncoviruses and their crosstalk in breast cancer is still unclear. METHODS: We explored the co-presence of high-risk HPVs, EBV, and MMTV-like virus in 74 breast cancer samples from Qatar using PCR. RESULTS: We found the presence of HPV and EBV in 65% and 49% of our cancer sample cohorts; 47% of the samples are positive for both oncoviruses. The MMTV-like virus alone was detected in 15% of the samples with no significant association with clinicopathological features. The three oncoviruses were co-present in 14% of the cases; no significant association was noted between the co-presence of these viruses and the clinicopathological features. CONCLUSION: Despite the presence of the oncoviruses, additional studies are necessary to understand their interactions in human breast carcinogenesis.

The relational regulation of within-person variation in personality expression.

There is renewed interest in how people express different levels of personality across situations or times (within-person variation). However, within-person studies typically do not focus on the specific relationship partners that are linked to the expression of personality. To remedy this, we applied relational regulation theory (RRT) to the study of within-person variation. RRT states that specific relationship partners are important social contexts for understanding within-person variation and describes how people regulate their affect, action and thought through interacting with or thinking about specific partners. In three studies of students (Ns = 136, 349, 110), participants rated their levels of six- or five-factor personality dimensions when with or thinking about different relationship partners. Personality expression was strongly consistent across partners. Yet, in each study, there were also strong effects whereby more extraversion, agreeableness and openness were expressed when with some partners but not others. In each study, when a recipient saw a relationship as supportive, the recipient expressed more extraversion, agreeableness, and openness. Effects for emotionality and conscientiousness were less consistent. Theoretical implications for RRT and within-person variation in personality were discussed.

IFN-induced cell-autonomous immune mechanisms in the control of intracellular protozoa.

Vertebrate cells have evolved an elaborate multi-tiered intracellular surveillance system linked to downstream antimicrobial effectors to defend themselves from pathogens. This cellular self-defense system is referred to as cell-autonomous immunity. A wide array of cell-autonomous mechanisms operates to control intracellular pathogens including protozoa such as Toxoplasma gondii. Cell-autonomous immunity consists of antimicrobial defenses that are constitutively active in cells and those that are inducible typically in response to host cell activation. The IFN family of cytokines is an important stimulator of inducible cell-autonomous immunity. There are several hundred interferon-stimulated genes (ISGs); many of them have known roles in inducible cell-autonomous immune mechanisms. The importance of IFN-γ activation of cell-autonomous immunity is evidenced by the fact that many intracellular pathogens have evolved a diversity of molecular mechanisms to inhibit activation of infected cells through the JAK-STAT pathway in response to IFN-γ. The goal of this review is to provide a broad framework for understanding the elaborate system of cell-autonomous immunity that acts as a first line of defense between a host and intracellular parasites.

ß-Myrcene Mitigates Colon Inflammation by Inhibiting MAP Kinase and NF-κB Signaling Pathways.

Inflammatory bowel diseases (IBDs) are chronic inflammatory disorders that include Crohn's disease (CD) and ulcerative colitis (UC). The incidence of IBD is rising globally. However, the etiology of IBD is complex and governed by multiple factors. The current clinical treatment for IBD mainly includes steroids, biological agents and need-based surgery, based on the severity of the disease. Current drug therapy is often associated with adverse effects, which limits its use. Therefore, it necessitates the search for new drug candidates. In this pursuit, phytochemicals take the lead in the search for drug candidates to benefit from IBD treatment. ß-myrcene is a natural phytochemical compound present in various plant species which possesses potent anti-inflammatory activity. Here we investigated the role of ß-myrcene on colon inflammation to explore its molecular targets. We used 2% DSS colitis and TNF-α challenged HT-29 adenocarcinoma cells as in vivo and in vitro models. Our result indicated that the administration of ß-myrcene in dextran sodium sulfate (DSS)-treated mice restored colon length, decreased disease activity index (DAI), myeloperoxidase (MPO) enzyme activity and suppressed proinflammatory mediators. ß-myrcene administration suppressed mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-κB) pathways to limit inflammation. ß-myrcene also suppressed mRNA expression of proinflammatory chemokines in tumor necrosis factor-α (TNF-α) challenged HT-29 adenocarcinoma cells. In conclusion, ß-myrcene administration suppresses colon inflammation by inhibiting MAP kinases and NF-κB pathways.

When Forecasting Mutually Supportive Matches Will Be Practically Impossible.

Forecasting which dyads will develop mutually supportive relationships is an important applied and basic research question. Applying psychometric theory to the design of forecasting studies shows that agreement between dyad members about their relationship (relational reciprocity) sets an upper limit for forecasting accuracy by determining the reliability of measurement. To test this, we estimated relational reciprocity in Study 1. Participants in seven samples (six student and one military; N = 504; Ndyads = 766) rated each other on support-related constructs in round-robin designs. Relational reciprocity was very low, undermining reliability. Formulas from psychometric theory predicted that forecasting supportive dyads would be practically impossible. To test this, we had participants in Study 2 complete a measure for matching dyads derived from recent theory. As predicted, supportive matches could not be forecast with acceptable precision. Theoretically, this falsifies some predictions of recent social-support theory. Practically, it remains unclear how to translate basic social-support research into effective interventions.

Prevalence of antibodies against a cyclic peptide mimicking the FG loop of the human papillomavirus type 16 capsid among Tunisian women.

BACKGROUND: In the past decade, cervical cancer has gone from being the second to the fourth most common cancer in women worldwide, but remains the second most common in developing countries. This cancer is most commonly caused by high-risk types of human papillomavirus (HPV), mainly type 16 (HPV16), which are sexually transmitted. This study aimed to investigate the usefulness of a cyclic synthetic peptide designed from the major L1 capsid protein of HPV16 for detecting anti-HPV16 antibodies. METHODS: We designed and synthetized a peptide that corresponds to the full sequence of the surface-exposed FG loop. We tested the antigenicity of the linear and the cyclic peptides against HPV16 L1 monoclonal antibodies. We used ELISA to detect anti-peptide antibodies in sera and cervical secretions of 179 Tunisian women, and we applied polymerase chain reaction and direct sequencing methods to detect and genotype HPV DNA. RESULTS: Both the linear and the cyclic peptides were recognized by the same neutralizing monoclonal antibodies, but the cyclic peptide was more reactive with human sera. The prevalence of the anti-peptide antibodies in sera was higher in women with low-grade squamous intraepithelial lesions (LGSIL) than in women with high-grade squamous intraepithelial lesions (HGSIL) (44% and 15%, respectively). This contrasts with HPV16 DNA prevalence. Compared to women from the general population, systemic IgG prevalence was significantly higher among sex workers (25%; P = 0.002) and women with LGSIL (44%; P = 0.001). In addition, systemic IgA and cervical IgG prevalence was higher among sex workers only (P = 0.002 and P = 0.001, respectively). We did not observe anti-peptide IgG antibodies in women with a current HPV16 infection. CONCLUSION: Anti-peptide IgG in sera or in cervical secretions could be markers of an effective natural immunization against HPV16. This may open novel perspectives for monitoring vaccinated women and for the design of synthetic peptide-based vaccines.

Co-prevalence of human Papillomaviruses (HPV) and Epstein-Barr virus (EBV) in healthy blood donors from diverse nationalities in Qatar.

BACKGROUND: Infections by both human oncoviruses, human Papillomaviruses (HPV) and Epstein-Barr virus (EBV) are very common in the adult human population and are associated with various malignancies. While HPV is generally transmitted sexually or via skin-to-skin contact, EBV is frequently transmitted by oral secretions, blood transfusions and organ transplants. This study aims to determine the prevalence and circulating genotypes of HPV and EBV in healthy blood donors in Qatar. METHODS: We explored the co-prevalence of high-risk HPVs and EBV in 378 males and only 7 females blood donors of different nationalities (mainly from Qatar, Egypt, Syria, Jordan, Pakistan, and India) residing in Qatar, using polymerase chain reaction (PCR). DNA was extracted from the buffy coat and genotyping was performed using PCR and nested-PCR targeting E6 and E7 as well as LMP-1 of HPV and EBV, respectively. RESULTS: We found that from the total number of 385 cases of healthy blood donors studied, 54.8% and 61% of the samples are HPVs and EBV positive, respectively. Additionally, our data revealed that the co-presence of both high-risk HPVs and EBV is 40.4% of the total samples. More significantly, this study pointed out for the first time that the most frequent high-risk HPV types in Qatar are 59 (54.8%), 31 (53.7%), 52 (49.1%), 51 (48.6%), 58 (47%) and 35 (45.5%), while the most commonly expressed low-risk HPV types are 53 (50.6%), 11 (45.5), 73 (41.7%) and 6 (41.3%), with all the cases showing multiple HPVs infection. CONCLUSION: In this study, we demonstrated for the first time that HPV and EBV are commonly co-present in healthy blood donors in Qatar. On the other hand, it is important to highlight that these oncoviruses can also be co-present in several types of human cancers where they can cooperate in the initiation and/or progression of these cancers. Therefore, more studies regarding the co-presence of these oncoviruses and their interaction are necessary to understand their cooperative role in human diseases.

Distribution pattern of amino acid mutations in chloroquine and antifolate drug resistance associated genes in complicated and uncomplicated Plasmodium vivax isolates from Chandigarh, North India.

BACKGROUND: The increasing antimalarial drug resistance is a significant hindrance to malaria control and elimination programs. For the last six decades, chloroquine (CQ) plus pyrimethamine remains the first-line treatment for P. vivax malaria. Regions where both P. falciparum and P. vivax co-exist, P. vivax is exposed to antifolate drugs due to either misdiagnosis or improper treatment that causes selective drug pressure to evolve. Therefore, the present study aims to estimate antimalarial drug resistance among the complicated and uncomplicated P. vivax patients. METHODS: A total of 143 P. vivax malaria positive patients were enrolled in this study, and DNA was isolated from their blood samples. Pvcrt-o, Pvmdr-1, Pvdhps, and Pvdhfr genes were PCRs amplified, and drug resistance-associated gene mutations were analyzed. Statistical analysis of the drug resistance genes and population diversity was performed using MEGA vs. 7.0.21 and DnaSP v software. RESULTS: Among the CQ resistance marker gene Pvcrt-o, the prevalence of K10 insertion was 17.5% (7/40) and 9.5% (7/73) of complicated and uncomplicated P vivax group isolates respectively. In Pvmdr-1, double mutant haplotype (M958/L1076) was found in 99% of the clinical isolates. Among the pyrimethamine resistance-associated gene Pvdhfr, the double mutant haplotype I13P33F57R58T61N117I173 was detected in 23% (11/48) in complicated and 20% (17/85) in uncomplicated group isolates. In the sulphadoxine resistance-associated Pvdhps gene, limited polymorphism was observed with the presence of a single mutant (D459A) among 16 and 5% of the clinical isolates in the complicated and uncomplicated group respectively. CONCLUSION: The study presents the situations of polymorphism in the antimalarial drug resistance-associated genes and emphasizes the need for regular surveillance. It is imperative for the development of suitable antimalarial drug policy in India.

Influx of diverse, drug resistant and transmissible Plasmodium falciparum into a malaria-free setting in Qatar.

BACKGROUND: Successful control programs have impeded local malaria transmission in almost all Gulf Cooperation Council (GCC) countries: Qatar, Bahrain, Kuwait, Oman, the United Arab Emirates (UAE) and Saudi Arabia. Nevertheless, a prodigious influx of imported malaria via migrant workers sustains the threat of local transmission. Here we examine the origin of imported malaria in Qatar, assess genetic diversity and the prevalence of drug resistance genes in imported Plasmodium falciparum, and finally, address the potential for the reintroduction of local transmission. METHODS: This study examined imported malaria cases reported in Qatar, between 2013 and 2016. We focused on P. falciparum infections and estimated both total parasite and gametocyte density, using qPCR and qRT-PCR, respectively. We also examined ten neutral microsatellites and four genes associated with drug resistance, Pfmrp1, Pfcrt, Pfmdr1, and Pfkelch13, to assess the genetic diversity of imported P. falciparum strains, and the potential for propagating drug resistance genotypes respectively. RESULTS: The majority of imported malaria cases were P. vivax, while P. falciparum and mixed species infections (P. falciparum / P. vivax) were less frequent. The primary origin of P. vivax infection was the Indian subcontinent, while P. falciparum was mostly presented by African expatriates. Imported P. falciparum strains were highly diverse, carrying multiple genotypes, and infections also presented with early- and late-stage gametocytes. We observed a high prevalence of mutations implicated in drug resistance among these strains, including novel SNPs in Pfkelch13. CONCLUSIONS: The influx of genetically diverse P. falciparum, with multiple drug resistance markers and a high capacity for gametocyte production, represents a threat for the reestablishment of drug-resistant malaria into GCC countries. This scenario highlights the impact of mass international migration on the reintroduction of malaria to areas with absent or limited local transmission.

Evaluation of in vitro activity of ceftazidime/avibactam and ceftolozane/tazobactam against MDR Pseudomonas aeruginosa isolates from Qatar.

OBJECTIVES: To investigate the in vitro activity of ceftazidime/avibactam and ceftolozane/tazobactam against clinical isolates of MDR Pseudomonas aeruginosa from Qatar, as well as the mechanisms of resistance. METHODS: MDR P. aeruginosa isolated between October 2014 and September 2015 from all public hospitals in Qatar were included. The BD PhoenixTM system was used for identification and initial antimicrobial susceptibility testing, while Liofilchem MIC Test Strips (Liofilchem, Roseto degli Abruzzi, Italy) were used for confirmation of ceftazidime/avibactam and ceftolozane/tazobactam susceptibility. Ten ceftazidime/avibactam- and/or ceftolozane/tazobactam-resistant isolates were randomly selected for WGS. RESULTS: A total of 205 MDR P. aeruginosa isolates were included. Of these, 141 (68.8%) were susceptible to ceftazidime/avibactam, 129 (62.9%) were susceptible to ceftolozane/tazobactam, 121 (59.0%) were susceptible to both and 56 (27.3%) were susceptible to neither. Twenty (9.8%) isolates were susceptible to ceftazidime/avibactam but not to ceftolozane/tazobactam and only 8 (3.9%) were susceptible to ceftolozane/tazobactam but not to ceftazidime/avibactam. Less than 50% of XDR isolates were susceptible to ceftazidime/avibactam or ceftolozane/tazobactam. The 10 sequenced isolates belonged to six different STs and all produced AmpC and OXA enzymes; 5 (50%) produced ESBL and 4 (40%) produced VIM enzymes. CONCLUSIONS: MDR P. aeruginosa susceptibility rates to ceftazidime/avibactam and ceftolozane/tazobactam were higher than those to all existing antipseudomonal agents, except colistin, but were less than 50% in extremely resistant isolates. Non-susceptibility to ceftazidime/avibactam and ceftolozane/tazobactam was largely due to the production of ESBL and VIM enzymes. Ceftazidime/avibactam and ceftolozane/tazobactam are possible options for some patients with MDR P. aeruginosa in Qatar.

Exploration of genetic diversity of Plasmodium vivax circumsporozoite protein (Pvcsp) and Plasmodium vivax sexual stage antigen (Pvs25) among North Indian isolates.

BACKGROUND: Malaria is one of the important vector-borne diseases with high fatality rates in tropical countries. The pattern of emergence and spread of novel antigenic variants, leading to escape of vaccine-induced immunity might be factors responsible for severe malaria. A high level of polymorphism has been reported among malarial antigens which are under selection pressure imposed by host immunity. There are limited reports available on comparative stage-specific genetic diversity among Plasmodium vivax candidate genes in complicated vivax malaria. The present study was planned to study genetic diversity (Pvcsp and Pvs25) among complicated and uncomplicated P. vivax isolates. METHODS: Pvcsp and Pvs2-specific PCRs and DNA sequencing were performed on P. vivax PCR positive samples. Genetic diversity was analysed using appropriate software. RESULTS: The present study was carried out on 143 P. vivax clinical isolates, collected from Postgraduate Institute of Medical Education and Research, Chandigarh. Among the classic and variant types of Pvcsp, the VK210 (99%; 115/116) was found to be predominant in both complicated and uncomplicated group isolates. Out of the various peptide repeat motifs (PRMs) observed, GDRADGQPA (PRM1) and GDRAAGQPA (PRM2) was the most widely distributed among the P. vivax isolates. Whereas among the Pvs25 isolates, 100% of double mutants (E97Q/I130T) in both the complicated (45/45) as well as in the uncomplicated (81/81) group was observed. CONCLUSION: An analysis of genetic variability enables an understanding of the role of genetic variants in severe vivax malaria.

Elimination of Babesia microti Is Dependent on Intraerythrocytic Killing and CD4+ T Cells.

Babesiosis is a tick-borne zoonosis caused by protozoans of the genus Babesia, apicomplexan parasites that replicate within erythrocytes. However, unlike related Plasmodium species, the pathogenesis of Babesia infection remains poorly understood. The primary etiological agent of babesiosis in the United States is B. microti. In healthy individuals, tick-transmitted infection with Babesia causes no specific clinical manifestations, with many having no symptoms at all. However, even in asymptomatic people, a Babesia carriage state can be established that can last up to a year or more. Current blood bank screening methods do not identify infected donors, and Babesia parasites survive blood-banking procedures and storage. Thus, Babesia can also be transmitted by infected blood, and it is currently the number one cause of reportable transfusion-transmitted infection in the United States. Despite a significant impact on human health, B. microti remains understudied. In this study, we evaluated the course of Babesia infection in three strains of mice, C57BL/6J, BALB/cJ, and C3H-HeJ, and examined the contribution of multiple immune parameters, including TLRs, B cells, CD4+ cells, IFN-γ, and NO, on the level of parasitemia and parasite clearance during acute babesiosis. We found that B. microti reaches high parasitemia levels during the first week of infection in all three mice strains before resolving spontaneously. Our results indicate that resolution of babesiosis requires CD4 T cells and a novel mechanism of parasite killing within infected erythrocytes.

Screening and identification of potential novel biomarker for diagnosis of complicated Plasmodium vivax malaria.

BACKGROUND: In the recent years Plasmodium vivax has been reported to cause severe infections associated with mortality. Clinical evaluation has limited accuracy for the early identification of the patients progressing towards the fatal condition. Researchers have tried to identify the serum and the plasma-based indicators of the severe malaria. Discovery of MicroRNA (miRNA) has opened up an era of identification of early biomarkers for various infectious and non-infectious diseases. MicroRNAs (miRNA) are the small non-coding RNA molecules of length 19-24 nts and are responsible for the regulation of the majority of human gene expressions at post transcriptional level. METHODS: We identified the differentially expressed miRNAs by microarray and validated the selected miRNAs by qRT-PCR. We assessed the diagnostic potential of these up-regulated miRNAs for complicated P. vivax malaria. Futher, the bioinformtic analysis was performed to construct protein-protein and mRNA-miRNA networks to identify highly regulated miRNA. RESULTS: In the present study, utility of miRNA as potential biomarker of complicated P. vivax malaria was explored. A total of 276 miRNAs were found to be differentially expressed by miRNA microarray and out of which 5 miRNAs (hsa-miR-7977, hsa-miR-28-3p, hsa-miR-378-5p, hsa-miR-194-5p and hsa-miR-3667-5p) were found to be significantly up-regulated in complicated P. vivax malaria patients using qRT-PCR. The diagnostic potential of these 5 miRNAs were found to be significant with sensitivity and specificity of 60-71% and 69-81% respectively and area under curve (AUC) of 0.7 (p < 0.05). Moreover, in silico analysis of the common targets of up-regulated miRNAs revealed UBA52 and hsa-miR-7977 as majorly regulated hubs in the PPI and mRNA-miRNA networks, suggesting their putative role in complicated P. vivax malaria. CONCLUSION: miR-7977 might act as a potential biomarker for differentiating complicated P. vivax malaria from uncomplicated type. The elevated levels of miR-7977 may have a role to play in the disease pathology through UBA52 or TGF-beta signalling pathway.

Pathogenic features of Streptococcus mutans isolated from dental prosthesis patients and diagnosed cancer patients with dental prosthesis.

Though S. mutans, virulence, and pathogenesis are characterized, reports are limited to the status of its carriage and virulence in patients with oral cancer and prosthesis. In this present study, we investigated the pathogenic characteristics of twenty strains of S. mutans of healthy subjects, fifteen of prosthesis patients, and eleven from oral cancer. The putative virulence gene and other factors, such as the ability to adhere to the oral epithelial cells, production of glycan and lactic acid of these strains were examined. Few of representative isolates of each group were used to see their activity on oral cancer cell line using cell cytotoxicity assay. The isolation rate of S. mutans was significantly more in carcinoma than prosthesis patients and control health group. The production of glycan and latic acid was together high in those isolates derived from prosthesis patients and patients with cancer. Adherence ability of strains isolated from prosthesis patients and cancer patients with oral prosthesis were significantly higher, compared to one isolated from a healthy individual. From our study results, we conclude that prosthesis patients and cancer patients with prosthesis carried a high number of S. mutans in their oral cavities. SIGNIFICANCE AND IMPACT OF STUDY: This study report that prosthesis patients and cancer patients with prosthesis carried a high number of S. mutans in their oral cavities. However, the S mutans are commensals still they have the capability to raise the severity of disease condition due to their ability to produce glycan and lactic acid. In our study, we proved that the adherence to buccal epithelial cells was significantly increased in S. mutans isolates of prosthesis patients and cancer patients. These indicate that in prosthesis patients as well as in cancerous patient's microbes had more potential to cause infection and increase the severity.

Protection of melatonin in experimental models of newborn hypoxic-ischemic brain injury through MT1 receptor.

The function of melatonin as a protective agent against newborn hypoxic-ischemic (H-I) brain injury is not yet well studied, and the mechanisms by which melatonin causes neuroprotection in neurological diseases are still evolving. This study was designed to investigate whether expression of MT1 receptors is reduced in newborn H-I brain injury and whether the protective action of melatonin is by alterations of the MT1 receptors. We demonstrated that there was significant reduction in MT1 receptors in ischemic brain of mouse pups in vivo following H-I brain injury and that melatonin offers neuroprotection through upregulation of MT1 receptors. The role of MT1 receptors was further supported by observation of increased mortality in MT1 knockout mice following H-I brain injury and the reversal of the inhibitory role of melatonin on mitochondrial cell death pathways by the melatonin receptor antagonist, luzindole. These data demonstrate that melatonin mediates its neuroprotective effect in mouse models of newborn H-I brain injury, at least in part, by the restoration of MT1 receptors, the inhibition of mitochondrial cell death pathways and the suppression of astrocytic and microglial activation.