Effectiveness Study of Paromomycin IM Injection (PMIM) for the Treatment of Visceral Leishmaniasis (VL) in Bangladesh

Development of Amphotericin B Decorated Gold Nanoparticles as a Promising Antileishmanial Nanoconjugate

Leishmaniasis, attributed to the protozoan parasite Leishmania, manifests in diverse clinical forms, including cutaneous, mucocutaneous, and visceral leishmaniasis; VL constitutes a significant global health menace. Prevalent in tropical and subtropical regions, this affliction disproportionately impacts individuals below the poverty threshold, transmitted through the bite of female sandflies. Existing treatments, such as pentavalent antimony, miltefosine, and Amphotericin B, exhibit limitations. Despite the emergence of liposomal Amphotericin B (AmBisome) as a promising antileishmanial agent, its utility is impeded by adverse effects, elevated production expenses, and cytotoxicity. To address these challenges, our investigation introduces a potential remedy─a citrate-coated gold Amphotericin B nanoparticle formulation. Characterized using dynamic light scattering and transmission electron microscopy, this pioneering formulation exhibited efficacy against L. donovani Ag83 promastigotes as demonstrated by MTT cell viability testing. Evaluating internal reactive oxygen species (ROS) levels and dual staining with acridine orange and ethidium bromide unveiled its consequential impact on cell death. Significantly, our study discloses this novel nanoformulation's unprecedented inhibition of the trypanothione reductase enzyme. The findings posit the citrate-coated gold Amphotericin B nanoformulation as a promising and targeted antileishmanial agent, representing potential advancements in leishmaniasis therapeutics.

Current developments and prospects of the antibiotic delivery systems

Antibiotics have remained the cornerstone for the treatment of bacterial infections ever since their discovery in the twentieth century. The uproar over antibiotic resistance among bacteria arising from genome plasticity and biofilm development has rendered current antibiotic therapies ineffective, urging the development of innovative therapeutic approaches. The development of antibiotic resistance among bacteria has further heightened the clinical failure of antibiotic therapy, which is often linked to its low bioavailability, side effects, and poor penetration and accumulation at the site of infection. In this review, we highlight the potential use of siderophores, antibodies, cell-penetrating peptides, antimicrobial peptides, bacteriophages, and nanoparticles to smuggle antibiotics across impermeable biological membranes to achieve therapeutically relevant concentrations of antibiotics and combat antimicrobial resistance (AMR). We will discuss the general mechanisms via which each delivery system functions and how it can be tailored to deliver antibiotics against the paradigm of mechanisms underlying antibiotic resistance.

The Potential Use of Peptides in the Fight against Chagas Disease and Leishmaniasis

Chagas disease and leishmaniasis are both neglected tropical diseases that affect millions of people around the world. Leishmaniasis is currently the second most widespread vector-borne parasitic disease after malaria. The World Health Organization records approximately 0.7-1 million newly diagnosed leishmaniasis cases each year, resulting in approximately 20,000-30,000 deaths. Also, 25 million people worldwide are at risk of Chagas disease and an estimated 6 million people are infected with Trypanosoma cruzi. Pentavalent antimonials, amphotericin B, miltefosine, paromomycin, and pentamidine are currently used to treat leishmaniasis. Also, nifurtimox and benznidazole are two drugs currently used to treat Chagas disease. These drugs are associated with toxicity problems such as nephrotoxicity and cardiotoxicity, in addition to resistance problems. As a result, the discovery of novel therapeutic agents has emerged as a top priority and a promising alternative. Overall, there is a need for new and effective treatments for Chagas disease and leishmaniasis, as the current drugs have significant limitations. Peptide-based drugs are attractive due to their high selectiveness, effectiveness, low toxicity, and ease of production. This paper reviews the potential use of peptides in the treatment of Chagas disease and leishmaniasis. Several studies have demonstrated that peptides are effective against Chagas disease and leishmaniasis, suggesting their use in drug therapy for these diseases. Overall, peptides have the potential to be effective therapeutic agents against Chagas disease and leishmaniasis, but more research is needed to fully investigate their potential.

Thymoquinone Effect on Leishmania tropica/infantum and Leishmania-Infected Macrophages

INTRODUCTION

Leishmania is a parasitic protozoan that tries to enter and amplify within macrophages. Macrophage cells are also immune defense cells that phagocyte many microbes like bacteria, fungi, as well as parasites like Leishmania spp. However, they are unable to kill this parasite that resides in the phagosomes of contaminated macrophages and multiplies in these macrophages, leading to the destruction of contaminated macrophages and the emerging of Leishmania wounds. A large number of current therapies for Leishmania cure have adverse effects, or parasites have developed resistance to some of these therapies, so a better therapy for the cure of Leishmania is required. Thymoquinone is one of the Nigella Sativa ingredients with numerous biological effects, such as antioxidant as well as antimicrobial effects on a variety of microbes, namely fungi, bacteria, as well as parasites like Leishmania spp. The impacts of Thymoquinone on Leishmania tropica and Leishmania infantum, as well as Leishmania-infected macrophages, were examined in this study.

METHODS

The impact of various Thymoquinone dosages on L. tropica and L. infantum promastigotes and amastigotes was examined in vitro. Flow cytometry, as well as MTT, was also applied to examine the cytotoxic activity of Thymoquinone on promastigotes of L. tropica and L. infantum, as well as the incidence of apoptosis. The amastigote assay is also utilized to calculate the % of contaminated macrophages as well as the number of the present parasites in each macrophage.

RESULTS

The percentage of macrophages contaminated with L. tropica and L. infantum amastigotes after medicating with 20 μM of Thymoquinone was 23% and 19%, respectively. Also, after medicating with 10 μM of Thymoquinone, these percentages were 32% and 31%, respectively. Flow cytometry indicated that Thymoquinone caused 33.9% and 31.4% apoptosis in L. tropica and L. infantum, respectively. As determined by the promastigote assay, the inhibitory concentration (IC50) of Thymoquinone for L. tropica and L. infantum was 9.49 μM and 12.66 μM, respectively. The results of the promastigote and amastigote assay show that with an increase in Thymoquinone doses, its ability to kill Leishmania parasites increases, too.

CONCLUSION

According to the results of the study, Thymoquinone has a potentially lethal impact on L. tropica and L. infantum promastigotes as well as amastigotes (within leishmania contaminated macrophages).

Isolation, typing, and drug susceptibility of Leishmania (Leishmania) infantum isolates from dogs of the municipality of Embu das Artes, an endemic region for canine leishmaniasis in Brazil

The parasitic protozoa Leishmania (Leishmania) infantum is the etiological agent of human visceral leishmaniasis and canine leishmaniasis in South America, where Brazil is the most affected country. This zoonotic disease is transmitted by the bite of an infected phlebotomine sand fly and dogs constitute the main domestic reservoir of the parasite. In this study, we screened 2348 dogs of the municipality of Embu das Artes, Brazil, for antibodies against the parasite. Prevalence for canine leishmaniasis seropositivity was 2.81%, as assessed using a Dual-Path Platform rapid test for canine leishmaniasis. Twenty-five seropositive dogs were euthanized for parasite isolation and 14 isolates were successful obtained. Nucleotide sequencing of the internal transcribed spacer confirmed the isolates to be L. (L.) infantum, and very low sequence variability was observed among them. The in vitro susceptibility to miltefosine and paromomycin was assessed and moderate variation in paromomycin susceptibility was found among the isolates in the promastigote and intracellular amastigote stages. On the other hand, in vitro susceptibility to miltefosine of these isolates was homogenous, particularly in the amastigote stage (EC₅₀ values from 0.69 to 2.07 μM). In addition, the miltefosine sensitivity locus was deleted in all the isolates, which does not corroborate the hypothesis that the absence of this locus is correlated with a low in vitro susceptibility. Our findings confirm that the municipality of Embu das Artes is endemic for canine leishmaniasis and that isolates from this region are susceptible to paromomycin and miltefosine, indicating the potential of these drugs to be clinically evaluated in the treatment of human visceral leishmaniasis in Brazil.

Visceral Leishmaniasis in pregnancy and vertical transmission: A systematic literature review on the therapeutic orphans

Background

Reports on the occurrence and outcome of Visceral Leishmaniasis (VL) in pregnant women is rare in published literature. The occurrence of VL in pregnancy is not systematically captured and cases are rarely followed-up to detect consequences of infection and treatment on the pregnant women and foetus.

Methods

A review of all published literature was undertaken to identify cases of VL infections among pregnant women by searching the following database: Ovid MEDLINE; Ovid Embase; Cochrane Database of Systematic Reviews; Cochrane Central Register of Controlled Trials; World Health Organization Global Index Medicus: LILACS (Americas); IMSEAR (South-East Asia); IMEMR (Eastern Mediterranean); WPRIM (Western Pacific); ClinicalTrials.gov; and the WHO International Clinical Trials Registry Platform. Selection criteria included any clinical reports describing the disease in pregnancy or vertical transmission of the disease in humans. Articles meeting pre-specified inclusion criteria and non-primary research articles such as textbook, chapters, letters, retrospective case description, or reports of accidental inclusion in trials were also considered.

Results

The systematic literature search identified 272 unique articles of which 54 records were included in this review; a further 18 records were identified from additional search of the references of the included studies or from personal communication leading to a total of 72 records (71 case reports/case series; 1 retrospective cohort study; 1926–2020) describing 451 cases of VL in pregnant women. The disease was detected during pregnancy in 398 (88.2%), retrospectively confirmed after giving birth in 52 (11.5%), and the time of identification was not clear in 1 (0.2%). Of the 398 pregnant women whose infection was identified during pregnancy, 346 (86.9%) received a treatment, 3 (0.8%) were untreated, and the treatment status was not clear in the remaining 49 (12.3%). Of 346 pregnant women, Liposomal amphotericin B (L-AmB) was administered in 202 (58.4%) and pentavalent antimony (PA) in 93 (26.9%). Outcomes were reported in 176 pregnant women treated with L-AmB with 4 (2.3%) reports of maternal deaths, 5 (2.8%) miscarriages, and 2 (1.1%) foetal death/stillbirth. For PA, outcomes were reported in 88 of whom 4 (4.5%) died, 24 (27.3%) had spontaneous abortion, 2 (2.3%) had miscarriages. A total of 26 cases of confirmed, probable or suspected cases of vertical transmission were identified with a median detection time of 6 months (range: 0–18 months).

Conclusions

Outcomes of VL treatment during pregnancy is rarely reported and under-researched. The reported articles were mainly case reports and case series and the reported information was often incomplete. From the studies identified, it is difficult to derive a generalisable information on outcomes for pregnant women and babies, although reported data favours the usage of liposomal amphotericin B for the treatment of VL in pregnant women.

Visceral Leishmaniasis (VL) is a neglected tropical disease with an estimated incidence of 50,000 to 90,000 cases in 2019. Women who are susceptible to becoming pregnant or those who are pregnant and lactating are regularly excluded from clinical studies of VL. A specific concern of public health relevance is the little knowledge of the consequences of VL and its treatment on the mother and the foetus. We did a systematic review of all published literature with an overarching aim of identifying cases of VL in pregnancy and assessing the risk-benefit balance of antileishmanial treatment to the pregnant women and the child. We identified a total of 72 records (1926–2020) describing 451 VL cases in pregnant women. In 398, infection was identified during pregnancy of whom 202 received Liposomal Amphotericin B (L-AmB) and 93 received pentavalent antimony (PA). In studies that reported maternal outcomes, reports of maternal death abortion/spontaneous abortion, and miscarriages were proportionally lower among those who received L-AmB compared to PA (no formal test of significance carried out). A total of 26 cases of confirmed, probable or suspected cases of vertical transmission were identified and the median time to detection was 6 months (range: 0–18 months). Our review brings together scattered observations of VL in pregnant women in the clinical literature and clearly highlights that the disease in pregnancy is under-reported and under-studied. The collated evidence derived mainly from case reports and case series indicate that L-AmB has a favourable safety profile than the antimony regimen and should be the preferred treatment for VL during pregnancy.

Efficacy and Safety of Paromomycin for Visceral Leishmaniasis: A Systematic Review

Visceral leishmaniasis, also known as kala-azar is one of the most commonly neglected tropical diseases affecting a large number of rural and resource-limited people in South Asia, Africa, and South America. Paromomycin, an aminoglycoside drug, is frequently used for the treatment of visceral leishmaniasis. Despite limited therapies for visceral leishmaniasis and emerging drug resistance, a proper review on the action of paromomycin for kala-azar is lacking. This systematic review aims to look for the efficacy and safety aspects of paromomycin for the treatment of visceral leishmaniasis.

Susceptibility to paromomycin in clinical isolates and reference strains of Leishmania species responsible for tegumentary leishmaniasis in Brazil

Treatment of tegumentary leishmaniasis in Brazil is limited to pentavalent antimonial, amphotericin B and pentamidine. These drugs, administered parenterally, cause several side effects and have a varied clinical response, depending on the species of Leishmania. Urgent expansion of the therapeutic arsenal against the disease is therefore necessary. Paromomycin is an aminoglycoside antibiotic that has already been approved for the treatment of visceral leishmaniasis in Southeast Asia. Here, we provide an in vitro evaluation of the activity of paromomycin in fifteen clinical isolates from patients with tegumentary leishmaniasis at a reference center for the treatment of the disease. Furthermore, the in vitro susceptibility to this drug in reference strains of Leishmania species that are endemic in Brazil has also been evaluated. Among the clinical isolates, nine were typed as Leishmania (Viannia) braziliensis, five as L. (Leishmania) amazonensis and one as L. (V.) guyanensis. Although never exposed to paromomycin, we found variable susceptibility among these isolates and reference strains in promastigotes and intracellular amastigotes, with the drug being more active in the amastigote form of the parasite. This study provides a preclinical dataset that is useful for the evaluation of paromomycin in the treatment of tegumentary leishmaniasis caused by species that are endemic in Brazil.

Production and statistical optimization of Paromomycin by Streptomyces rimosus NRRL 2455 in solid state fermentation

BACKGROUND

Paromomycin is a 2-deoxystreptamine aminocyclitol aminoglycoside antibiotic with broad spectrum activity against Gram-negative, Gram-positive bacteria and many protozoa. This study introduces a strategy for paromomycin production through solid-state fermentation using Streptomyces rimosus subsp. paromomycinus NRRL 2455. Solid state fermentation has gained enormous attention in the development of several products because of their numerous advantages over submerged liquid fermentation. After selecting the best solid substrate, a time course study of paromomycin production was carried out followed by optimization of environmental conditions using response surface methodology. Paromomycin yields obtained using this technique were also compared to those obtained using submerged liquid fermentation.

RESULTS

Upon screening of 6 different substrates, maximum paromomycin concentration (0.51 mg/g initial dry solids) was obtained with the cost-effective agro-industrial byproduct, corn bran, impregnated with aminoglycoside production media. Optimization of environmental conditions using D-optimal design yielded a 4.3-fold enhancement in paromomycin concentration reaching 2.21 mg/g initial dry solids at a pH of 8.5, inoculum size of 5% v/w and a temperature of 30 °C.

CONCLUSION

Compared to submerged liquid fermentation, solid state fermentation resulted in comparable paromomycin concentrations, cost reduction of raw materials, less energy consumption and waste water discharge, which have major implications in industrial fermentation. Therefore, solid state fermentation is a promising alternative to submerged liquid fermentation for paromomycin production. To the best of our knowledge, this is the first report on the optimized paromomycin production through solid state fermentation process.

Activity of paromomycin against Leishmania amazonensis: Direct correlation between susceptibility in vitro and the treatment outcome in vivo

Paromomycin is an aminoglycoside antibiotic approved in 2006 for the treatment of visceral leishmaniasis caused by Leishmania donovani in Southeast Asia. Although this drug is not approved for the treatment of visceral and cutaneous leishmaniasis in Brazil, it is urgent and necessary to evaluate the potential of this drug as alternative for the treatment against species responsible for these clinical forms of the disease. In Brazil, Leishmania amazonensis is responsible for cutaneous and diffuse cutaneous leishmaniasis. The diffuse cutaneous form of the disease is difficult to treat and frequent relapses are reported, mainly when the treatment is interrupted. Here, we evaluated paromomycin susceptibility in vitro of a L. amazonensis clinical isolate from a patient with cutaneous leishmaniasis and the reference strain L. amazonensis M2269, as well as its in vivo efficacy in a murine experimental model. Although never exposed to paromomycin, a significant differential susceptibility between these two lines was found. Paromomycin was highly active in vitro against the clinical isolate in both forms of the parasite, while its activity against the reference strain was less active. In vivo studies in mice infected with each one of these lines demonstrated that paromomycin reduces lesion size and parasite burden and a direct correlation between the susceptibility in vitro and the effectiveness of this drug in vivo was found. Our findings indicate that paromomycin efficacy in vivo is dependent on intrinsic susceptibility of the parasite. Beyond that, this study contributes for the evaluation of the potential use of paromomycin in chemotherapy of cutaneous leishmaniasis in Brazil caused by L. amazonensis.

Screening Marine Natural Products for New Drug Leads against Trypanosomatids and Malaria

Neglected Tropical Diseases (NTD) represent a serious threat to humans, especially for those living in poor or developing countries. Almost one-sixth of the world population is at risk of suffering from these diseases and many thousands die because of NTDs, to which we should add the sanitary, labor and social issues that hinder the economic development of these countries. Protozoan-borne diseases are responsible for more than one million deaths every year. Visceral leishmaniasis, Chagas disease or sleeping sickness are among the most lethal NTDs. Despite not being considered an NTD by the World Health Organization (WHO), malaria must be added to this sinister group. Malaria, caused by the apicomplexan parasite Plasmodium falciparum, is responsible for thousands of deaths each year. The treatment of this disease has been losing effectiveness year after year. Many of the medicines currently in use are obsolete due to their gradual loss of efficacy, their intrinsic toxicity and the emergence of drug resistance or a lack of adherence to treatment. Therefore, there is an urgent and global need for new drugs. Despite this, the scant interest shown by most of the stakeholders involved in the pharmaceutical industry makes our present therapeutic arsenal scarce, and until recently, the search for new drugs has not been seriously addressed. The sources of new drugs for these and other pathologies include natural products, synthetic molecules or repurposing drugs. The most frequent sources of natural products are microorganisms, e.g., bacteria, fungi, yeasts, algae and plants, which are able to synthesize many drugs that are currently in use (e.g. antimicrobials, antitumor, immunosuppressants, etc.). The marine environment is another well-established source of bioactive natural products, with recent applications against parasites, bacteria and other pathogens which affect humans and animals. Drug discovery techniques have rapidly advanced since the beginning of the millennium. The combination of novel techniques that include the genetic modification of pathogens, bioimaging and robotics has given rise to the standardization of High-Performance Screening platforms in the discovery of drugs. These advancements have accelerated the discovery of new chemical entities with antiparasitic effects. This review presents critical updates regarding the use of High-Throughput Screening (HTS) in the discovery of drugs for NTDs transmitted by protozoa, including malaria, and its application in the discovery of new drugs of marine origin.

Relationship between treatment regimens for visceral leishmaniasis and development of post-kala-azar dermal leishmaniasis and visceral leishmaniasis relapse: A cohort study from Bangladesh

Background

We investigated the relationship of treatment regimens for visceral leishmaniasis (VL) with post-kala-azar dermal leishmaniasis (PKDL) and visceral leishmaniasis relapse (VLR) development.

Methods

Study subjects included cohorts of patients cured of VL since treatment with monotherapy by sodium stibogluconate (SSG), miltefosine (MF), paromomycin intramuscular injection (PMIM), liposomal amphotericin B [AmBisome (AMB)] in a single dose (SDAMB) and in multidose (MDAMB), and combination therapies by AMB+PMIM, AMB+MF, and PMIM+MF. Follow up period was 4 years after treatment. Cohorts were prospective except SSG (retrospective) and MF (partially retrospective). We compared incidence proportion and rate in 100-person-4year of PKDL and VLR by treatment regimens using univariate and multivariate analysis.

Findings

974 of 984 enrolled participants completed the study. Overall incidence proportion for PKDL and VLR was 12.3% (95% CI, 10.4%–14.5%) and 7.0% (95% CI, 5.6%–8.8%) respectively. The incidence rate (95% CI) of PKDL and VLR was 14.0 (8.6–22.7) and 7.6 (4.1–14.7) accordingly. SSG cohort had the lowest incidence rate of PKDL at 3.0 (1.3–7.3) and VLR at 1.8 (0.6–5.6), followed by MDAMB at 8.2 (4.3–15.7) for PKDL and at 2.7 (0.9–8.4) for VLR.

Interpretation

Development of PKDL and VLR is related with treatment regimens for VL. SSG and MDAMB resulted in less incidence of PKDL and VLR compared to other treatment regimens. MDAMB should be considered for VL as a first step for prevention of PKDL and VLR since SSG is highly toxic and not recommended for VL.

Post-kala-azar Dermal Leishmaniasis (PKDL), a sequale of visceral leishmaniasis (VL), and reappearance VL (visceral leishmaniasis relapse, VLR) are intra-epidemic reservoirs of VL and threats control of VL in long run. Currently there is no strategy for prevention of PKDL and VLR. If a relationship between treatment for VL and development of PKDL and VLR is there, and then selection of proper treatment regimen for VL should prevent PKDL and VLR. So far no study has been carried out to investigate the relationship between treatment regimens for VL and development of PKDL and VLR. The study demonstrated that multi-dose liposomal amphotericin B (AmBisome) defined as MDAMB herein for VL results in least PKDL and VLR among all existing and recommended by WHO treatment regimens for VL. We recommend adaptation of MDAMB in the national visceral leishmaniasis elimination program for VL cases management during subsequent phases of the national program when VL burden is low and hospitalization of VL patients for 3-5-days is now feasible.

Current and promising novel drug candidates against visceral leishmaniasis

Leishmaniasis is a group of zoonotic diseases caused by a trypanosomatid parasite mostly in impoverished populations of low-income countries. In their different forms, leishmaniasis is prevalent in more than 98 countries all over the world and approximately 360-million people are at risk. Since no vaccine is currently available to prevent any form of the disease, the control strategy of leishmaniasis mainly relies on early case detection followed by adequate pharmacological treatment that may improve the prognosis and can reduce transmission. A handful of compounds and formulations are available for the treatment of leishmaniasis in humans, but only few of them are currently in use since most of these agents are associated with toxicity problems such as nephrotoxicity and cardiotoxicity in addition to resistance problems. In recent decades, very few novel drugs, new formulations of standard drugs or combinations of them have been approved against leishmaniasis. This review highlights the current drugs and combinations that are used medical practice and recent advances in new treatments against leishmaniasis that were pointed out in the recent 2nd Conference, Global Challenges in Neglected Tropical Diseases, held in San Juan, Puerto Rico in June 2018, emphasizing the plethora of new families of molecules that are bridging the gap between preclinical and first-in-man trials in next future.

Assessment of quality of life using WHOQOL-BREF in patients with visceral leishmaniasis

BACKGROUND

This study was aimed to assess the impact of quality of life using WHOQOL-BREF in patients with Visceral leishmaniasis (VL).

METHODS

A total of 95 VL cases and 95 healthy participants filled out the questionnaires. Data on socio-demographic aspects along with disease duration were collected. Data were compared using a t-test, analysis of variance and chi-square test.

RESULTS

VL patients experienced very high impact on their quality of life. Study cohort had male preponderance (72.63%). Majority (64.21%) were aged < 40 years. Longer disease duration was found to have significantly poor quality of life (p < 0.05). The physical domain was found to be most affected domains of quality of life (QOL). QOL was affected most in illiterate, married, housewife, rural population and patients with longer disease duration (p < 0.05). The psychological and environmental domains were significantly affected in > 40 years of age group married patients (p < 0.05).

CONCLUSIONS

VL significantly impaired the patients' (QOL) in all four domains (physical, psychological, social relationship and environmental). Physical domain was significantly the most affected domain.

Paromomycin production from Streptomyces rimosus NRRL 2455: statistical optimization and new synergistic antibiotic combinations against multidrug resistant pathogens

BACKGROUND

Response surface methodology (RSM) employing Box-Behnken design was used to optimize the environmental factors for the production of paromomycin, a 2 deoxystreptamine aminocyclitol aminoglycoside antibiotic, (2DOS-ACAGA) from Streptomyces (S.) rimosus NRRL 2455. Emergence of bacterial resistance caught our attention to consider the combination of antimicrobial agents. The effect of paromomycin combination with other antimicrobial agents was tested on some multiple drug resistant isolates. To the best of our knowledge, this is the first report on optimization of paromomycin production from S. rimosus NRRL 2455. A Quadratic model and response surface method were used by choosing three model factors; pH, incubation time and inoculum size. A total of 17 experiments were done and the response of each experiment was recorded. Concerning the effect of combining paromomycin with different antimicrobial agents, it was tested using the checkerboard assay against six multidrug resistant (MDR) pathogens including; Pseudomonas (P.) aeruginosa (2 isolates), Klebsiella (K.) pneumoniae, Escherichia (E.) coli, methicillin sensitive Staphylococcus aureus (MSSA) and methicillin resistant Staphylococcus aureus (MRSA). Paromomycin was tested in combination with ceftriaxone, ciprofloxacin, ampicillin/sulbactam, azithromycin, clindamycin and doxycycline.

RESULTS

The optimum conditions for paromomycin production were a pH of 6, an incubation time of 8.5 days and an inoculum size of 5.5% v/v using the optimized media (soybean meal 30 g/L, NH4CL 4 g/L, CaCO3 5 g/L and glycerol 40 ml/L), 28 °C incubation temperature, and 200 rpm agitation rate that resulted in 14 fold increase in paromomycin production as compared to preliminary fermentation level using the basal medium. The tested antibiotic combinations showed either synergistic effect on paromomycin activity on most of the tested MDR pathogens (45.83%), additive effect in 41.67% or indifferent effect in 12.5%.

CONCLUSION

RSM using multifactorial design was a helpful and a reliable method for paromomycin production. Paromomycin combination with ceftriaxone, ciprofloxacin, ampicillin/sulbactam, azithromycin, clindamycin or doxycycline showed mostly synergistic effect on certain selected clinically important MDR pathogens.

Amphotericin B deoxycholate for relapse visceral leishmaniasis in Bangladesh: a cross-sectional study

Objective

Based on studies in India (as there was no studies from outside India) amphotericin B deoxycholate has been considered as a backup drug for treatment of visceral leishmaniasis. However, treatment response and adverse effect to anti-leishmanial drugs may vary across different populations and in Bangladesh the effect to amphotericin B deoxycholate for treatment of visceral leishmaniasis is still unknown. Therefore, there is a need to explore cure rate and adverse effects to amphotericin B deoxycholate to justify its use on visceral leishmaniasis patients in Bangladesh.

Result

Here we report 34 visceral leishmaniasis patients who received treatment with amphotericin B deoxycholate in the Surya Kanta Kala-azar Research Centre from December 2011 to June 2015. The dose of the treatment was 1 mg/kg body weight for 15 days followed up until 12 months after treatment. Response to amphotericin B deoxycholate treatment was excellent as all 34 patients achieved a final cure. Hypokalaemia (47%), shivering (47%), vomiting (35%) and acidity (15%) were most common adverse events. However, we did not observe any serious adverse events. Amphotericin B deoxycholate for relapse visceral leishmaniasis was found to be highly effective and safe. Our study justified to include amphotericin B deoxycholate as a second line drug for visceral leishmaniasis in Bangladesh.

Electronic supplementary material

The online version of this article (10.1186/s13104-018-4036-8) contains supplementary material, which is available to authorized users.

Using focused pharmacovigilance for ensuring patient safety against antileishmanial drugs in Bangladesh's National Kala-azar Elimination Programme

Background

Adverse effects of antileishmanial drugs can affect patients’ quality of life and adherence to therapy for visceral leishmaniasis (VL) and post-kala-azar dermal leishmaniasis (PKDL). In Bangladesh, there are 26 treatment centers that manage leishmaniasis cases coming from 100 endemic upazilas (subdistricts) of 26 districts (these include VL, PKDL, treatment failure, and relapse VL and cutaneous leishmaniasis cases). This study aimed to investigate the feasibility of using focused pharmacovigilance for VL (VLPV) in Bangladesh’s National Kala-azar Elimination Programme for the early detection and prevention of expected and unexpected adverse drug reactions (ADRs).

Methods

This activity has been going on since December 2014. Activity area includes secondary public hospital or Upazila health complex (UHC) in hundred sub districts and Surya Kanta Kala-azar Research Center (SKKRC) in Mymensingh District, a specialized center for management of complicated VL and PKDL cases. Communicable Disease Control (CDC) of the Directorate General of Health Services (DGHS) assigned twenty five of hundred UHCs and SKKRC (total 26) as treatment centers depending on their suitable geographical location. This was implemented for better management of VL cases with Liposomal Amphotericin B (AmBisome®) to ensure patient convenience and proper utilization of this expensive donated drug. A VLPV expert committee and a UHC VLPV team were established, an operational manual and pharmacovigilance report forms were developed, training and refresher training of health personnel took place at UHCs and at the central level, collected information such as patient data including demographics, treatment history and response, adverse events were analyzed. This report includes information for the period from December 2014 to December 2016.

Results

From December 2014 to December 2016, 1327 leishmaniasis patients were treated and 1066 (80%) were available for VLPV. Out of these, 57, 33, 9, and 1% were new VL, PKDL, VL relapse, and other cases, respectively. Liposomal amphotericin B was mostly used (82%) for case management, followed by miltefosine (20%) and paromomycin (3%). Out of the 1066 patients, 26% experienced ADRs. The most frequent ADR was fever (17%, 176/1066), followed by vomiting (5%, 51/1066). Thirteen serious adverse events (SAEs) (eight deaths and five unexpected SAEs) were observed. The expert committee assessed that three of the deaths and all unexpected SAEs were possibly related to treatment. Out of the five unexpected SAEs, four were miltefosine-induced ophthalmic complications and the other was an AmBisome®-induced avascular necrosis of the nasal alae. The Directorate General of the Drug Administration entered the ADRs into the World Health Organization Uppsala Monitoring Centre (WHO-UMC) VigiFlow database.

Conclusions

This study found that VLPV through NKEP is feasible and should be continued as a routine activity into the public health system of Bangladesh to ensure patient safety against anti-leishmanial drugs.

Electronic supplementary material

The online version of this article (10.1186/s40249-018-0461-0) contains supplementary material, which is available to authorized users.

Chemotherapeutics of visceral leishmaniasis: present and future developments

Treatment of Visceral Leishmaniasis (VL), a neglected tropical disease, is very challenging with few treatment options. Long duration of treatment and drug toxicity further limit the target of achieving VL elimination. Chemotherapy remains the treatment of choice. Single dose of liposomal amphotericin B (LAmB) and multidrug therapy (LAmB + miltefosine, LAmB + paromomycin (PM), or miltefosine + PM) are recommended treatment regimen for treatment of VL in Indian sub-continent. Combination therapy of pentavalent antimonials (Sbv) and PM in East Africa and LAmB in the Mediterranean region/South America remains the treatment of choice. Various drugs having anti-leishmania properties are in preclinical phase and need further development. An effective treatment and secondary prophylaxis of HIV-VL co-infection should be developed to decrease treatment failure and drug resistance.

Efficacy and Safety of Liposomal Amphotericin B for Visceral Leishmaniasis in Children and Adolescents at a Tertiary Care Center in Bihar, India

Liposomal amphotericin B is being used increasingly to reduce the burden of kala-azar from the Indian subcontinent. There are studies which have evaluated efficacy and safety of liposomal amphotericin B for visceral leishmaniasis in all age groups. However, the only study that specifically addressed treatment of childhood visceral leishmaniasis did not include all ages or document renal and liver function. We, therefore, felt it was important to reassess the efficacy and safety of single dose liposomal amphotericin B in children and adolescents. A total of 100 parasitologically confirmed visceral leishmaniasis patients aged < 15 years were included in this study. Participants consisted of 65 males and 35 females. All of them had come from the endemic region of Bihar. They were administered one dose intravenous infusion of liposomal amphptericin B at 10 mg/kg body weight. Efficacy was assessed as initial and final cure at 1 and 6 months, respectively, and safety of all participants who were recruited in the study. The initial and final cure rate by per protocol analysis was 100% and 97.9%, respectively. Chills and rigors were the most commonly occurring adverse events (AEs). All the AEs were mild in intensity, and none of the patients experienced any serious AEs. No patients developed nephrotoxicity. Our finding indicates that liposomal amphotericin B at 10 mg/kg body weight is safe and effective in children. Results of our study support the use of single dose liposomal amphotericin B in all age group populations for elimination of kala-azar from the Indian subcontinent.

A Synthetic Strategy for Conjugation of Paromomycin to Cell-Penetrating Tat(48-60) for Delivery and Visualization into Leishmania Parasites

A successful approach to deliver paromomycin, a poorly absorbed aminoglycoside antibiotic, to parasite cells is reported, based on selective protection of amino and hydroxyl groups followed by conjugation to a fluorolabeled, PEG-functionalized cell-penetrating Tat(48-60) peptide. The resulting construct is efficiently internalized into Leishmania cells, evidencing the fitness of cell-penetrating peptides as vectors for efficiently transporting low-bioavailability drugs into cells.

Effectiveness of Short-Course Meglumine Antimoniate (Glucantime®) for Treatment of Visceral Leishmaniasis: A 13-Year, Multistage, Non-Inferiority Study in Iran

The World Health Organization's (WHO) recommendation is 28-day course of meglumine antimoniate (Glucantime^®, Sanofi Aventis, France) for the treatment of visceral leishmaniasis (VL). The aim of this study was to evaluate the effectiveness of a shorter duration of treatment in regions with low level of resistance to Glucantime. During 13 years, this study was conducted in three phases on 392 patients. In the pilot first phase, we performed splenic punctures in seven patients to assess the correlation between the changes in the parasite load during treatment with Glucantime and defervescence. With defervescence, parasite density was dramatically dropped (P = 0.014), propounding defervescence as a marker of parasitological response. On the basis of the results, we conducted a randomized trial on 75 patients, comparing the efficacy of continuation of Glucantime therapy for 1, 2, or 3 weeks after defervescence. The treatment course of 1 week after defervescence (mean = 11.7 days) was non-inferior to that of 3 weeks (final cure rate, 96% versus 100%; P = 0.023). The third phase was a retrospective cohort study of 302 patients treated either with the WHO's regimen or for 7 days after defervescence (intervention group). Relapse was detected in 8.3% patients of the intervention group and in 5% patients following the WHO's regimen (P = 0.006 for non-inferiority). The final duration of treatment in intervention group was significantly shorter than standard course (13.3 ± 2.6 versus 28 days; P < 0.001). In summary, treatment of VL with Glucantime for 1 week after defervescence was non-inferior to and appears to be an acceptable alternative to the standard 28-day course for patients in Iran who show a response to antimonial therapy.

Recent developments and future prospects in the treatment of visceral leishmaniasis

Limited therapeutic options in visceral leishmaniasis (VL) make the treatment of this neglected disease very challenging. In addition to this, long treatment duration and toxic adverse effects make it even more difficult. With no effective vaccine available to date, treatment of VL is based only on chemotherapy. In the Indian subcontinent, a single dose of liposomal amphotericin B (L-AmB) and multidrug therapy (L-AmB + miltefosine, L-AmB + paromomycin [PM], or miltefosine + PM) are the treatments of choice for VL. In East Africa, however, combination therapy of pentavalent antimonials (Sb(v)) and PM remains the treatment of choice, and in the Mediterranean region and South America, L-AmB is the recommended drug. Fexinidazole and PA-824 are new promising drugs which have shown encouraging results in preclinical studies.