Asymmetrical reproductive interference between Aedes aegypti and Aedes albopictus: Implications for coexistence.

BACKGROUND OBJECTIVES: Aedes aegypti and Aedes albopictus are two sympatric mosquito species that compete with each other for resources when their breeding habitats overlap. This study examines what happens when sympatric Ae. aegypti and Ae. albopictus mosquitoes' mate with each other and other species by looking at insemination rates, fecundity, and hatchability rate. METHODS: We performed controlled mating experiments in laboratory setting, assessing both conspecific and interspecific crosses. We measured insemination rates, egg numbers, and hatching success to examine the reproductive interference dynamics between these two distinct mosquito species. RESULTS: In the context of conspecific mating, it was observed that both female Ae. aegypti and Ae. albopictus exhibited high insemination rates, with percentages of 98% and 94% respectively. However, interspecific mating exhibited interesting asymmetries: Ae. albopictus males achieved a notable insemination success rate of 28% when mating with Ae. aegypti females, while Ae. aegypti males achieved only an 8% insemination success with Ae. albopictus females. Additionally, females that mated with interspecific males had reduced production of viable eggs compared to conspecific mating. Most notably, interspecific mating resulted in the production of infertile eggs, while conspecific mating led to successful hatching. INTERPRETATION CONCLUSION: The study reveals that Ae. aegypti and Ae. albopictus can asymmetrically interfere with each other's reproduction, causing a 'satyr' effect. This understanding of interspecific competition and reproductive interference in these mosquito species could impact their coexistence in shared breeding habitats.

Serum creatinine phosphokinase: A potential prognostic marker in assessing clinical severity with organophosphorus poisoning.

INTRODUCTION: Organophosphorus compound (OPC) poisoning undoubtedly being a major concern in cultivation sites of the developing world, including Bangladesh. Two potential biomarkers, for example, serum creatine phosphokinase (CPK) and lactate dehydrogenase (LDH), are widely used in OPC poisoning severity indicators in patients. In this study, we sought to correlate the severity score of acute OPC poisoning with CPK or LDH level and subsequently explore their prognostic value. METHODS: This study was performed on a total of 70 patients with OPC poisoning admitted to the inpatient care unit at a territory-based hospital in Bangladesh. Sociodemographics and poison types were recorded, and severity was assessed according to Peradeniya Organophosphorus Poisoning (POP) scale. Serum CPK and LDH levels were measured and recorded. RESULTS: A total of seventy OPC patients were included with male to female ratio of 1.33:1, respectively, with a mean age of 28.7 ± 12.8 years. Chlorpyrifos and methylparathion were the most commonly utilized OP compounds, accounting for 42.9% and 28.6%, respectively. Among the OPC patients, the majority were married homemakers from rural areas. According to POP score, 55.7% and 37.1% of patients were categorized as mild and moderate, whereas very few were found to be severe. The mean serum CPK and LDH of OPC-patients at admission time were 235.6 ± 79.8 IU/L and 348.3 ± 154.1 IU/L, respectively. Serum CPK, atropine dose and hospital stay strongly correlated with clinical severity. CONCLUSION: We conclude that the serum CPK level strongly correlates with the degree of OPC poisoning and can be used as a predictor of the clinical intervention approaches.

Isolation of multidrug resistance bacteria from the patients with wound infection and their antibiotics susceptibility patterns: A cross-sectional study.

Introduction: Antimicrobial resistance has become one of the most severe public problems in both developed and developing countries like Bangladesh. In this study, several multi-drug resistant bacteria were isolated from the wound infections and demonstrated their antibiotic susceptibility pattern in Bangladeshi patients. Methods: A total of 699 bacterial isolates were collected from wound swabs and each isolate was identified using gram staining, biochemical assays, antibiotic susceptibility tests with the disk diffusion method, and colony morphology. Samples were taken from January 2018 to December 2019. The analysis was conducted using SPSS (Inc., Chicago, IL, USA), and descriptive statistics were employed to illustrate the findings. Results: We have found 14.4% gram-positive bacteria (n = 100) and 85.6% gram-negative bacteria (n = 595) among the 695 samples by gram staining methods. The most prevalent gram-positive and gram-negative bacteria present in wound infections were Staphylococcus spp. (81.5%) and Pseudomonas spp. (89%), respectively. Antimicrobials that were mostly resistant to gram-negative isolates were Amoxicillin (75.8%), Cefixime (75.5%), Cefuroxime (70.3%), and Ceftazidime (69.6%). On the other hand, cefixime and ceftazidime accounted for 73% of the resistance against gram-positive isolates, followed by amoxicillin (71%), and penicillin-G (69%). Meropenem was found to be the most sensitive antibiotic for gram-negative bacteria. Meropenem and Gentamycin were found to have a percentage of sensitivity for gram-positive bacteria. Based on the assessment of 13 different antimicrobial classes, the percentage of multi-drug resistant bacteria identified in gram-negative bacteria was 84% and in gram-positive bacteria was 79%. Among gram-negative bacterial isolates, 82% pseudomonas spp, 88.5% Klebsiella spp, and 91.6% Proteus spp were reported as multi-drug resistant. On the other hand, Pseudomonas spp, Klebsiella spp, and Proteus spp. were found to be multi-drug resistant in 82%, 88.5%, and 91.6% of gram-negative bacterial isolates, respectively. It was shown that staphylococcus aureus (81%) and staphylococcus spp (78.6%) became gram-positive among gram-positive isolates. Conclusion: According to this study, frequently isolated bacteria have a high frequency of MDR, which is the most pressing issue in public health. This study helps to manage the evidence-based treatment strategy and the urgency of early identification of drug-resistant bacteria that can reduce disease burden.

RLLB/Alb ratio: a promising noninvasive diagnostic marker in assessing esophageal varices in cirrhotic patients.

BACKGROUND: Endoscopy has long been widely used to screen for esophageal varices (EV) in cirrhotic patients. Recurrent endoscopy is a significant burden for the healthcare system of the endoscopic unit as well as uncomfortable and high costs for patients. This study intended to prognosticate Right Liver Lobe Diameter/Serum Albumin Ratio (RLLD/Alb) as a non-invasive approach in the early diagnosis of EV among chronic liver disease (CLD) Bangladeshi patients enrolled in a specific hospital. PARTICIPANTS AND METHODS: A total of 150 admitted patients with CLD were included in the study. Patients were subjected through a comprehensive biochemical checkup and upper digestive endoscopic or ultrasonographic inspection. The correlation was evaluated between the RLLD/Alb ratio and esophageal varices grades. RESULTS: The upper digestive endoscopy demonstration among 150 patients resulted in no EV in 18%, while 24% of patients was identified as EV grade I, 20% as grade II, 20% as grade III, and 18% patients as grade IV. The mean value of the RLLD/Alb ratio was 4.89 ± 1.49 (range from 2.30 to 8.45). The RLLD/Alb ratio diagnosed the EV employing the cut-off value of 4.01 with 85.3% sensitivity and 68.8% specificity. Furthermore, it was positively correlated with the grading of EV, when this ratio increased the grading of EV increases and vice versa (r = 0.630, p < 0.001). CONCLUSION: The RLLD/Alb ratio is a non-invasive parameter giving exact guidance relevant to the ascertainment of the existence of EV and their grading in chronic liver disease patients.

A Viral-Vectored Multi-Stage Malaria Vaccine Regimen With Protective and Transmission-Blocking Efficacies.

Malaria parasites undergo several stages in their complex lifecycle. To achieve reductions in both the individual disease burden and malaria transmission within communities, a multi-stage malaria vaccine with high effectiveness and durability is a more efficacious strategy compared with a single-stage vaccine. Here, we generated viral-vectored vaccines based on human adenovirus type 5 (AdHu5) and adeno-associated virus serotype 1 (AAV1) expressing a fusion protein of the pre-erythrocytic stage Plasmodium falciparum circumsporozoite protein (PfCSP) and the transmission-blocking sexual stage P25 protein (Pfs25). A two-dose heterologous AdHu5-prime/AAV1-boost immunization regimen proved to be highly effective for both full protection and transmission-blocking activity against transgenic P. berghei parasites expressing the corresponding P. falciparum antigens in mice. Remarkably, the immunization regimen induced antibody responses to both PfCSP and Pfs25 for over 9 months after the boosting and also maintained high levels of transmission-reducing activity (TRA: >99%) during that period, as evaluated by a direct feeding assay. If similar efficacies on P. falciparum can be shown following vaccination of humans, we propose that this multi-stage malaria vaccine regimen will be a powerful tool for malaria control, providing greater overall protection and cost-effectiveness than single-stage vaccines.

Adeno-Associated Virus as an Effective Malaria Booster Vaccine Following Adenovirus Priming.

An ideal malaria vaccine platform should potently induce protective immune responses and block parasite transmission from mosquito to human, and it should maintain these effects for an extended period. Here, we have focused on vaccine development based on adeno-associated virus serotype 1 (AAV1), a viral vector widely studied in the field of clinical gene therapy that is able to induce long-term transgene expression without causing toxicity in vivo. Our results show the potential utility of AAV1 vectors as an extremely potent booster vaccine to induce durable immunity when combined with an adenovirus-priming vaccine in a rodent malaria model. We generated a series of recombinant AAV1s and human adenovirus type 5 (AdHu5) expressing either Plasmodium falciparum circumsporozoite protein (PfCSP) or P25 (Pfs25) protein. Heterologous two-dose immunization with an AdHu5-prime and AAV1-boost (AdHu5-AAV1) elicited robust and durable PfCSP- or Pfs25-specific functional antibodies over 280 days. Regarding protective efficacy, AdHu5-AAV1 PfCSP achieved high sterile protection (up to 80% protection rate) against challenge with transgenic Plasmodium berghei sporozoites expressing PfCSP. When examining transmission-blocking (TB) efficacy, we found that immunization with AdHu5-AAV1 Pfs25 maintained TB activity in vivo against transgenic P. berghei expressing Pfs25 for 287 days (99% reduction in oocyst intensity, 85% reduction in oocyst prevalence). Our data indicate that AAV1-based malaria vaccines can confer potent and durable protection as well as TB efficacy when administered following an AdHu5 priming vaccine, supporting the further evaluation of this regimen in clinical trials as a next-generation malaria vaccine platform.

Down-selecting circumsporozoite protein-based malaria vaccine: A comparison of malaria sporozoite challenge model.

Plasmodium falciparum circumsporozoite protein (PfCSP) is the main target antigen in development of pre-erythrocytic malaria vaccines. To evaluate PfCSP vaccines in animal models, challenge by intravenous sporozoite injection is preferentially used. However, in clinical trials, vaccinated human volunteers are exposed to the bites of malaria-infected mosquitoes. In this study, we down-selected Escherichia coli-produced full-length PfCSP (PfCSP-F) and its three truncated PfCSPs based on their abilities to elicit immune response and protection in mice against two challenge models. We showed that immunization with three doses of PfCSP-F elicited high anti-PfCSP antibody titres and 100% protection against the bites of infected mosquitoes. Meanwhile, three-dose truncated PfCSP induced 60%-70% protection after immunization with each truncated PfCSP. Heterologous prime-boost immunization regimen with adenovirus-PfCSP-F and R32LR greatly induced complete protection against intravenous sporozoite injection. Our results suggest that Abs to both anti-repeat and anti-nonrepeat regions induced by PfCSP-F are required to confer complete protection against challenge by the bites of infected mosquitoes, whereas anti-repeat Abs play an important role in protection against intravenous sporozoite injection. Our findings provide a potential clinical application that PfCSP-F vaccine induces potent Abs capable of neutralizing sporozoites in the dermis inoculated by infected mosquitoes and subsequently sporozoites in the blood circulation.

Anopheline antiplatelet protein from mosquito saliva regulates blood feeding behavior.

The saliva of hematophagous arthropods is enriched with a complex mixture of antihemostatic molecules, the biological functions of which are largely unknown. Anopheline antiplatelet protein (AAPP) from malaria vector mosquito exhibits strong antiplatelet activity when bound directly to host collagen by its C-terminus and through its N-terminus with Ca2+-binding activity. To investigate the biological functions of AAPP in blood feeding behavior and malaria transmission, we generated transgenic Anopheles stephensi mosquito lines expressing anti-AAPP antibody single-chain fragment (scFv) in their salivary glands. The AAPP-specific collagen-binding activity was completely abolished by AAPP-scFv complex formation in the saliva. Probing and prediuresis time, feeding success, blood meal size, and fecundity, which are all fitness characteristics, were significantly reduced in the transgenic mosquitoes. However, oocysts number in these mosquitoes were not significantly reduced following blood meal intake from Plasmodium berghei-infected mice. These results show that although AAPP plays an important role in mosquito blood feeding, its neutralizing activity did not affect sporogonic development in our laboratory model, but its high fitness cost would pose a survival risk for parasite-infected mosquitoes in nature.

Baculovirus-Induced Fast-Acting Innate Immunity Kills Liver-Stage Plasmodium.

Baculovirus (BV), an enveloped insect virus with a circular dsDNA genome, possesses unique characteristics that induce strong innate immune responses in mammalian cells. In this study, we show that BV administration in BALB/c mice not only provides complete protection against a subsequent Plasmodium berghei sporozoite infection for up to 7 d after the injection but also eliminates existing liver-stage parasites completely. The elimination of sporozoites by BV was superior to that by primaquine, and this effect occurred in a TLR9-independent manner. At 6 h after BV administration, IFN-α and IFN-γ were robustly produced in the serum, and RNA transcripts of IFN-stimulated genes were markedly upregulated in the liver compared with control mice. The in vivo passive transfer of serum after BV administration effectively eliminated liver-stage parasites, and IFN-α neutralization abolished this effect, indicating that the BV liver-stage parasite-killing mechanism is downstream of the type I IFN signaling pathway. These findings provide evidence that BV-induced, fast-acting innate immunity completely kills liver-stage parasites and, thus, may lead to new malaria drug and vaccine strategies.

In silico-based vaccine design against Ebola virus glycoprotein.

Ebola virus (EBOV) is one of the lethal viruses, causing more than 24 epidemic outbreaks to date. Despite having available molecular knowledge of this virus, no definite vaccine or other remedial agents have been developed yet for the management and avoidance of EBOV infections in humans. Disclosing this, the present study described an epitope-based peptide vaccine against EBOV, using a combination of B-cell and T-cell epitope predictions, followed by molecular docking and molecular dynamics simulation approach. Here, protein sequences of all glycoproteins of EBOV were collected and examined via in silico methods to determine the most immunogenic protein. From the identified antigenic protein, the peptide region ranging from 186 to 220 and the sequence HKEGAFFLY from the positions of 154-162 were considered the most potential B-cell and T-cell epitopes, correspondingly. Moreover, this peptide (HKEGAFFLY) interacted with HLA-A*32:15 with the highest binding energy and stability, and also a good conservancy of 83.85% with maximum population coverage. The results imply that the designed epitopes could manifest vigorous enduring defensive immunity against EBOV.

Molecular docking analysis of known flavonoids as duel COX-2 inhibitors in the context of cancer.

Cyclooxygenase-2 (COX-2) catalyzed synthesis of prostaglandin E2 and it associates with tumor growth, infiltration, and metastasis in preclinical experiments. Known inhibitors against COX-2 exhibit toxicity. Therefore, it is of interest to screen natural compounds like flavanoids against COX-2. Molecular docking using 12 known flavanoids against COX-2 by FlexX and of ArgusLab were performed. All compounds showed a favourable binding energy of >-10 KJ/mol in FlexX and > -8 kcal/mol in ArgusLab. However, this data requires in vitro and in vivo verification for further consideration.

Molecular docking of fisetin with AD associated AChE, ABAD and BACE1 proteins.

Alzheimer׳s disease (AD) is one of the most common dementias showing slow progressive cognitive decline. Progression of intracerebral accumulation of beta amyloid (Aß) peptides by the action of amyloid binding alcohol dehydrogenase (ABAD), a mitochondrial enzyme and ß-site amyloid precursor protein cleaving enzyme 1 (BACE1) and the degradation of Acetylcholinesterase (AChE) the main pathological characteristics of AD. Therefore, it is of interest to evaluate the importance of fisetin (a flavonol that belongs to the flavonoid group of polyphenols) binding with AChE, ABAD and BACE1 proteins. Docking experiment of fisetin with these proteins using two different tools namely iGEMDOCK and FlexX show significant binding with acceptable binding values. Thus, the potential inhibitory role of fisetin with AD associated proteins is documented.