Finding epitopes of Klebsiella pneumoniae outer membrane protein-K17 (OMPK17) and introducing a 25-mer peptide of it as a vaccine candidate.

No approved vaccine exists for Klebsiella pneumoniae yet. Outer membrane protein-K17 (OMPK17) is involved in K. pneumoniae pathogenesis. No information has been found about OMPK17 dominant epitopes in the literature. Therefore, this study aimed to predict both T cell and B cell epitopes of K. pneumoniae OMPK17 via immunoinformatics approaches. Both T cell (class-I and II) and B cell (linear and discontinuous) epitopes of OMPK17 were predicted. Several screening analyses were performed including clustering, immunogenicity, human similarity, toxicity, allergenicity, conservancy, docking, and structural/physicochemical suitability. The results showed that some regions of OMPK17 have more potential as epitopes. The most possible epitopes were found via several analyses including the selection of higher-scoring epitopes, the epitopes predicted with more tools, more immunogenic epitopes, the epitopes capable of producing interferon-gamma, the epitopes with more dissimilarity to human peptides, and non-toxic and non-allergenic epitopes. By comparing the best T cell and B cell epitopes, we reached a 25-mer peptide containing both T cell (class-I and class-II) and B cell (linear) epitopes and comprising appropriate physicochemical characteristics that are required for K. pneumoniae vaccine development. The in vitro/in vivo study of this peptide is recommended to clarify its actual efficiency and efficacy. Supplementary information: The online version contains supplementary material available at 10.1007/s11756-023-01371-0.

Comparison of Therapeutic Effect and Safety of Oral and Rectal Use of Acetaminophen on Patent Ductus Arteriosus in Preterm Infants: Clinical Randomized Trial.

The prevalence of patent ductus arteriosus (PDA) in preterm infants is high. There is little information about the therapeutic effect and safety of rectal acetaminophen in the treatment of PDA. We aimed to compare the therapeutic effect and safety of oral and rectal acetaminophen on PDA in preterm infants. This study was a single-blind randomized clinical trial using 40 preterm infants. The cases were hospitalized in the neonatal intensive care unit of Mohammad Kermanshahi and Imam Reza hospitals of Kermanshah. Subjects were randomly divided into 2 groups, the first group was treated with oral acetaminophen and the second group was treated with rectal acetaminophen. The presence of PDA and response to treatment was assessed based on pre- and post-treatment echocardiographic criteria. The likelihood of complications or prohibition of acetaminophen use was assessed with paraclinical tests before and after treatment. The neonates were in the age range of 30 to 35 weeks. Twenty-one cases (52.5%) were boys and 19 cases (47.5%) were girls. Two cases in the oral-acetaminophen group and 1 case in the rectal-acetaminophen group needed the second round of treatment. There was no difference between the success of treatment and the type of treatment. The study showed that there was no difference between PDA treatment of preterm infants with oral and rectal acetaminophen. Also, no side effects were observed in treatment with any of the treatments. Therefore, it could be suggested that in infants who are intolerant to oral acetaminophen, the rectal form can be used.

Prevention of mother-to-child transmission of HIV in Kermanshah, west of Iran from 2014 to 2021.

BACKGROUND: This study aimed to evaluate the implementation of the prevention of mother-to-child transmission (PMTCT) of the HIV-PMTCT program in Kermanshah, west of Iran, from 2014 to 2021. METHODS: The data of all HIV-infected mothers and their infants who were monitored by the Kermanshah behavioral diseases counseling center was extracted and recorded in a checklist. RESULTS: Out of 95 included infant, 45 (47.4%) were girls and 50 (52.6%) were boys. The mothers were mostly infected with HIV via their infected spouse. The pregnancies of 77 cases (82.1%) were in accordance with the national guideline. The average length of treatment for this group was 185 days. Of the 18 mothers who did not receive treatment, nine were diagnosed during childbirth and nine had no available information. All infants born from infected mothers underwent after-birth-antiretroviral prophylaxis, and all remained healthy. There was no statistically significant relationship between the birth weight and height of neonates with maternal age, maternal last viral load, disease stage, education, and maternal CD4 levels. Only a statistically significant relationship was observed between the duration of treatment and the infants' weight. CONCLUSION: The results suggest the feasibility and effectiveness of the PMTCT program for HIV-positive mothers in Kermanshah. It seems that if pregnant HIV-positive women are diagnosed early and covered by a good prevention program on time, the risk of HIV to their babies will be reduced, significantly.

Prevalence of Antibiotic-Resistant Lactobacilli in Sepsis Patients with Long-Term Antibiotic Therapy.

Lactobacilli are the most common probiotic bacteria found in the human gut microbiota, and the presence of acquired antibiotic resistance determinants carried on mobile genetic elements must be screened due to safety concerns. Unnecessary and inappropriate antibiotic therapy, as well as ingested antibiotic resistance bacteria (originating from food or food products), influence the abundance of antibiotic resistance genes in human guts, with serious clinical consequences. The current study looked into the antibiotic resistance of lactobacilli isolated from the guts of sepsis patients on long-term antibiotic therapy. The broth microdilution method was used to investigate the minimum inhibitory concentrations (MICs) of antibiotics such as imipenem, meropenem, erythromycin, tetracycline, cefepime, ciprofloxacin, and gentamycin, and the molecular genetic basis of resistance was studied based on the MIC values. The isolates were phenotypically resistant to tetracycline (20%), fluoroquinolone (20%), and macrolide (5%). Following that, resistance genes for tetracycline [tet(L), tet(O), tet(K), and tet(M)], macrolide [erm(B) and erm(C)], and beta-lactams [bla(CMY)] were investigated. Tetracycline or macrolide resistance genes were not found in the isolates, and only one isolate possessed the bla(CMY) resistance gene. The findings suggested that tetracycline and macrolide resistance may be linked to other resistance genes that were not investigated in this study. Because tetracyclines, fluoroquinolones, and macrolides are commonly used in clinics and animals, there has been concern about the spread of resistance in humans. If acquired antibiotic resistance is passed down through mobile genetic elements, it may serve as a reservoir of resistance for gut pathogens and other microbiome environments.

Survival-related factors in HIV/AIDS patients: A retrospective cohort study from 2011 to 2019 in Kermanshah, Iran.

INTRODUCTION: Accurate evaluation of the survival rate among HIV-positive populations is pivotal for HIV management. OBJECTIVE: This study aimed to investigate the survival rate and potential survival-related factors in HIV/AIDS patients from 2011 to 2019 in the city of Kermanshah in the west of Iran. METHOD: In this study, 915 HIV-positive patients registered by the Kermanshah Behavioral diseases counseling center, were surveyed from 2011 to 2019. By reading the patients' files, the proper data related to the survival factors were extracted and statistically analyzed. RESULTS: Of 915 patients, 220 (24%) died. The one-year, five-year, and ten-year survival rates were 84%, 72%, and 62%, respectively. There was a significant relationship between the survival rate and many other parameters, including treatment variables, CD4+ T cell count, the way of HIV transmission, level of education, gender, and marital status. Over time, timely initiation of treatment has increased. The data also showed that HIV transmission through drug injection has decreased, while the sexual transmission of HIV has increased. CONCLUSIONS: The results showed that in recent years, due to the appropriate treatment, the survival rate of HIV patients has increased. The highest risk factor of death was for people with low CD4+ T cell count, lack of antiretroviral therapy, low level of education, male gender, and people who inject drugs. These people need more attention to get tested for HIV- related indexes and to receive proper treatment.

A systematic review and meta-analysis on the antibiotic resistance of Neisseria meningitidis in the last 20 years in the world.

BACKGROUND: Neisseria meningitidis is one of the most important causes of meningitis and pathogens-associated deaths in developing and developed countries. Effective anti-microbial agents are pivotal to treat and control N. meningitidis infections. The aim of the present study was to systematically review published studies on the antibiotic resistance of N. meningitidis in the last 20 years (2000-2020) in the world. METHODS: Published researches were identified through a literature search using reputable databases including PubMed, Scopus, and Web of Science. Finally, 24 studies were included for a random-effects model meta-analysis. RESULTS: The overall resistance to most commonly used antibiotics such as ceftriaxone, cefotaxime, ciprofloxacin and rifampin was low, ranging from 1 to 3.4%. However, non-sensitivity to penicillin, as the first-line antibiotic against N. meningitidis, was higher (27.2%). Altogether, the resistance to the first-line antibiotics (except penicillin) is still low indicating these drugs are effective against meningococcal meningitis. We also found a significant gap between MIC and disk diffusion for evaluating resistance to antibiotics in which disk diffusion overestimate the resistance rate. CONCLUSIONS: To properly management and prevent the spread of N. miningitidis isolates resistant antibiotics, it is necessary to monitor the pattern of antibiotic susceptibility regionally and globally using the MIC methods.

Clinical manifestations, associated diseases, diagnosis, and treatment of human infections caused by Erysipelothrix rhusiopathiae: a systematic review.

Introduction: Erysipelothrix rhusiopathiae is a bacillus that can cause cutaneous and systemic diseases in humans. Studies on the infection caused by this bacterium have been mostly done as case reports. This study aimed to systematically review E. rhusiopathiae infection cases published over the last 20 years. Methods: Science Direct, PubMed, Scopus, Google Scholar, and Web of Science were searched using appropriate keywords to find relevant studies. After assessment of the studies, 57 case reports which surveyed 62 patients were included and their data were collected and analyzed. Results: The majority of cases were adult men living in high-income countries with an animal-related job and/or a history of animal contacts. The number of cases has increased in recent years. The main underlying diseases that were associated with E. rhusiopathiae infections include hypertension, diabetes, and alcoholism. The most frequent presentations were fever, pain, local skin lesions, and heart failure/endocarditis. Two patients died, while 60 patients were recovered following antibiotic therapy, mainly with penicillin and ceftriaxone. Conclusions: Altogether, the results indicated that E. rhusiopathiae usually infects people who come into contact with animals and causes mild to severe local or systemic infections, especially in those who have underlying diseases. Therefore, accurate and early diagnosis of E. rhusiopathiae infections by setting up appropriate laboratory tests is required.

A systematic review and meta-analysis of Listeria monocytogenes isolated from human and non-human sources: the antibiotic susceptibility aspect.

Listeria monocytogenes causes listeriosis with a high mortality rate. This study systematically reviewed the antibiotic susceptibility of L. monocytogenes in the world. A literature search was done and the data of 33 studies that matched with the inclusion criteria, were used for meta-analysis. The random-effect model meta-analysis was applied to determine the frequency of overall L. monocytogenes and its antibiotic non-sensitive isolates. The frequency of L. monocytogenes contamination in non-human sources was 10.3%. The most frequent serotypes were 4b and 4ab in human and non-human isolates, respectively. The resistance of L. monocytogenes isolates to the first-line antibiotics namely penicillin, ampicillin/amoxicillin, gentamicin, and trimethoprim-sulfamethoxazole has been increased in recent years. Altogether, the results indicated a concern for the antibiotic resistance in L. monocytogenes isolates over time. The implement of the registry and surveillance systems is required to improve the insight of L. monocytogenes antibiotic susceptibility and its treatment choices.

Immunoinformatics and molecular dynamics studies to predict T-cell-specific epitopes of four Klebsiella pneumoniae fimbriae antigens.

Klebsiella pneumoniae (K. pneumoniae) is a causative agent of severe infections in humans. There is no publically available vaccine for K. pneumoniae infections yet. Here, using comprehensive immunoinformatics methods, T-cell-specific epitopes of four type 1 fimbriae antigens of K. pneumoniae were predicted and evaluated as potential vaccine candidates. Both CD8+ (class I) and CD4+ (class II) T-cell-specific epitopes were predicted and the epitopes similar to human proteome were excluded. Subsequently, the windows of class-II epitopes containing class-I epitopes were determined. The immunogenicity, IFN-γ production and population coverage were also estimated. Using the 3D structure of HLA and epitopes, molecular docking was carried out. Two best epitopes were selected for molecular dynamics studies. Our prediction and analyses resulted in the several dominant epitopes for each antigen. The docking results showed that all selected epitopes can bind to their restricted HLA molecules with high affinity. The molecular dynamics results indicated the stability of system with minimum possible deviation, suggesting the selected epitopes can be promising candidates for stably binding to HLA molecules. Altogether, our results suggest that the selected T-cell-specific epitopes of K. pneumoniae fimbriae antigens, particularly the two epitopes confirmed by molecular dynamics, can be applied for vaccine development. However, the in vitro and in vivo studies are required to authenticate the results of the present study.Communicated by Ramaswamy H. Sarma.

Detecting the Dominant T and B Epitopes of Klebsiella pneumoniae Ferric Enterobactin Protein (FepA) and Introducing a Single Epitopic Peptide as Vaccine Candidate.

Klebsiella pneumoniae causes various human infections. Ferric enterobactin protein (FepA) is a conserved protein of K. pneumoniae with high immunogenicity. In the present study, using comprehensive in silico approaches the T and B cell-specific epitopes of K. pneumoniae FepA were identified. The T (both class I and class II) and B (both linear and conformational) epitopes of FepA were predicted using prediction tools. The predicted epitopes were screened for human similarity, immunogenicity, antigenicity, allergenicity, toxicity, conservancy, structural and physicochemical suitability, and in case of T epitopes binding to HLA alleles, using numerous immune-informatics, homology modeling, and molecular docking approaches. These analyses led to introduce the most dominant FepA epitopes that are appropriate for vaccine development. Furthermore, we introduced an antigenic peptide containing both T and B epitopes which comprises suitable structural and physiochemical properties needed for vaccine development and it is conserved in many bacteria. Altogether, here the highly immunogenic T and B epitopes of FepA as well as a final epitopic peptide containing both T and B epitopes were found and introduced for future vaccine development studies. It is suggested that the actual efficiency and efficacy of our final epitopic peptide be investigated by in vitro/in vivo testing. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10989-021-10247-3.

The effects of natural disasters on leishmaniases frequency: A global systematic review and meta-analysis.

OBJECTIVES: Natural disasters (NDs) may increase the outbreaks and transmissions of vector-borne diseases such as cutaneous leishmaniasis (CL) and visceral leishmaniasis (VL). However, the relationship between leishmaniases and NDs has not yet been clearly established. Here, we systematically reviewed all reported articles in this field to answer whether NDs increase the frequency of leishmaniases. METHODS: All the related articles published during January 2000 till January 2020 were reviewed. Moreover, all NDs and the associated leishmaniases frequencies reports in 17 leishmaniases endemic countries were searched to find any ND-leishmaniases relationship. RESULTS: After the initial screening, 39 articles on ND-leishmaniases were selected and systematically reviewed. These articles showed different frequencies of CL in the endemic areas before and after NDs in some regions of Pakistan and Iran and in case of VL in Brazil, Ethiopia, and Sudan. After thorough deliberation, four studies for CL-ND and five studies for VL-ND relationships were selected for meta-analysis. The results showed increases in the leishmaniases incidences after NDs, although not robustly. CONCLUSION: The lack of a strong leishmaniases-ND relationship could be attributed to the local compilations of such data in scattered regions of the endemic countries. Therefore, currently a substantial knowledge gap on leishmaniases-ND relationship is apparent.

B Cell Epitopes of Four Fimbriae Antigens of Klebsiella pneumoniae: A Comprehensive In Silico Study for Vaccine Development.

Klebsiella pneumoniae is one of the major causes of nosocomial infections worldwide which can cause several diseases in children and adults. The globally dissemination of hyper-virulent strains of K. pneumoniae and the emergence of antibiotics-resistant isolates of this pathogen narrows down the treatment options and has renewed interest in its vaccines. Vaccine candidates of Klebsiella pneumoniae have not been adequately protective, safe and globally available yet. In K. pneumoniae infection, it is well known that B cells that induce robust humoral immunity are necessary for the host complete protection. Identifying the B cell epitopes of antigens is valuable to design novel vaccine candidates. In the present study using immunoinformatics approaches we found B cell epitopes of four K. pneumoniae type 1 fimbriae antigens namely FimA, FimF, FimG, and FimH. Linear and conformational B cell epitopes of each antigen were predicted using different programs. Subsequently, many bioinformatics assays were applied to choose the best epitopes including prediction antigenicity, toxicity, human similarity and investigation on experimental records. These assays resulted in final four epitopes (each for one Fim protein). These final epitopes were modeled and their physiochemical properties were estimated to be used as potential vaccine candidates. Altogether, we found four B cell epitopes of K. pneumoniae Fim antigens that are immunogen, antigenic, not similar to human peptides, not allergen and not toxic. Also, they have suitable physiochemical properties to administrate as vaccine, although their complete efficacy should be also shown in vitro and in vivo.

Antimicrobial Resistance of Staphylococcus aureus Isolated from Hospital Wastewater in Kermanshah, Iran.

INTRODUCTION: Hospital wastewater contains highly resistant and virulent bacteria that can spread into the environment. This study was conducted to investigate the antimicrobial resistance of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) in raw and treated hospital wastewater. METHODS: During a three-month period, 40 sewage samples were collected from the hospital sewage (Kermanshah, Iran), and S. aureus were identified using culture and biochemical tests. MRSA was detected by resistance to cefoxitin. Antibiotic resistance (AR) was determined using disk diffusion according to the Clinical and Laboratory Standards Institute (CLSI) in 20 MSSA (10 raw and 10 treated sewage) and 40 MRSA isolates (20 raw and 20 treated sewage). The antimicrobial resistance genes (ARGs) were determined by PCR. RESULTS: Eleven and eight percent of the isolates were MRSA in raw and treated sewage samples, respectively. Out of 60 isolates, 59 (98%) were multidrug resistant (MDR). The most common ARGs were mecA (raw=100%, treated=100%), aacA-D (raw=100%, treated=85%) and tetK (raw =95%, treated =45%) in MRSA, while the tetM gene was the most abundant gene (raw=50%, treated=80%) in MSSA. None of isolates (n=60) was positive for the vanB gene. MSSR (n=20) had the highest level of resistance against penicillin (100%), clindamycin (raw=90%, treated=90%), azithromycin (raw=80%, treated=90%). All MRSA isolates (n=40,100%) in both raw and treated sewage samples were non-susceptible to penicillin, oxacillin and azithromycin. There was no significant difference in the frequency AR and ARGs between raw and treated sewage samples (p>0.05). CONCLUSION: The results indicated a high frequency of MDR and ARGs in both raw and treated sewage isolates which could be released into the environment through sewage system and pose a serious threat to public health. Hospital wastewater treatment processes should be improved in order to prevent the dissemination of the most resistant strains of S. aureus.

Usefulness of Blood Parameters for Preliminary Diagnosis of Brucellosis.

BACKGROUND: Human brucellosis is a multisystem disease with a wide range of clinical signs which often leads to misdiagnosis and treatment delay. Early diagnosis of this disease can prevent the serious complications and mismanagements. This study aimed to evaluate the hematological parameters with predictive value for the diagnosis of brucellosis. METHODS: In this prospective case-control study which was done during 2015-2017 in Imam Reza Hospital, Kermanshah Province, west Iran, 100 patients with a confirmed diagnosis of brucellosis (brucellosis group) and 100 healthy individuals (control group) were studied. The hematological parameters, including hemoglobin (Hb), red blood cell (RBC), white blood cell (WBC) count, lymphocyte count, neutrophil count, platelet count (PLTs), mean platelet volume (MPV), platelet distribution width (PDW), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) of both groups were recorded. The data were statistically compared between the brucellosis and the control groups. RESULTS: The mean age of patients and healthy groups was 44.04 ± 23.11 and 37.92 ± 24.80, respectively (P = 0.062). The WBC, CRP and neutrophil counts were significantly higher in the brucellosis group (P < 0.05). Based on the receiver operating characteristic (ROC) analysis, the sensitivity and specificity were 54% and 66% for the WBC, 45% and 71% for the neutrophil and 65% and 72% for the CRP, respectively. There was no statistically significant difference between the two groups in terms of Hb, RBC, WBC, lymphocyte and platelet count, MPV, PDW and ESR (P > 0.05). CONCLUSION: The results of this study indicate that WBC, CRP and neutrophil count can be used as valuable markers in the preliminary diagnosis of brucellosis. However, further researches are required to standardize these parameters for various forms of brucellosis.

Effect of Vigna radiata, Tamarix ramosissima and Carthamus lanatus extracts on Leishmania major and Leishmania tropica: An in vitro study.

Objective: Current therapy strategies of leishmaniasis have some problems such as high cost, toxicity and side effects. Plant extracts can be a source of drugs to control leishmaniasis. In this study, the effect of hydroalcoholic and chloroformic extracts of Vigna radiata, Tamarix ramosissima, and Carthamus lanatus on Leishmania major and L. tropica was studied. Methods: The plant samples were collected from west of Iran and their extracts were prepared. Anti-promastigote activity assay of all extracts was done using tetrazolium-dye assay. Results: Only high concentrations of V. radiata and C. lanatus were able to inhibit Leishmania, while both high and low concentrations of T. ramosissima had antileishmanial effect. No difference was observed between hydroalcoholic with chloroformic extract of each plant. Conclusion: Altogether, the results revealed the antileishmanial activity of T. ramosissima extracts against L. major and L. tropica, indicating its potential as an antileishmanial agent.

Leishmania tropica: The comparison of two frequently-used methods of parasite load assay in vaccinated mice

Objective: To compare limiting dilution assay and real-time PCR methods in Leishmania tropica parasite load measurement in vaccinated mice.Methods: BALB/c mice were vaccinated by Leishmania tropica soluble Leishmania antigen or recombinant Leishmania tropica stress-inducible protein-1 with/without adjuvant. After three vaccinations, mice were challenged by Leishmania tropica promastigotes. Two months after challenge, the draining lymph nodes of mice footpad were removed and parasite load was assayed by limiting dilution assay and real-time PCR methods. Limiting dilution assay was done by diluting tissue samples to extinction in a biphasic medium. For real-time PCR, DNA of the lymph nodes was extracted, equal dilutions of each sample were prepared and hot-start real-time PCR was done using appropriate primers. The data of the two methods were compared by appropriate statistical methods. Results: Both methods were able to measure different levels of parasite load in vaccinated/unvaccinated mice. In addition, wherever parasite load of a group was estimated high (or low) by one method, the estimated parasite load by another method was the same, although statistically significant differences were found between some groups. Conclusions: Both methods lead to approximately similar results in terms of differentiating parasite load of the experimental groups. However, due to the lower errors and faster process, the real-time PCR method is preferred.

Effectiveness of Two Types of Photostimulable Phosphor Plate Plastic Barrier Envelopes for Prevention of Microbiological Contamination

Abstract Objective: To compare the effectiveness of two types of commercially available photostimulable phosphor plate (PSP) protective barrier envelopes to prevent microbiological contamination. Material and Methods: In this cross-sectional study, 80 barrier envelopes were tested in 40 volunteers. The PSP plates were placed individually in Asia Teb and Soredex protective barrier envelopes and were placed in the mouth for two minutes, similar to periapical films. The protective barrier envelopes were then removed under sterile conditions, and the sensors were placed on different culture media. The number of colonies on each plate was counted. Data were analyzed using SPSS via McNemar and Wilcoxon tests. Results: Bacterial growth was noted in 17.5% of PSPs with Soredex, and 32.5% of PSPs with Asia Teb barrier envelopes. Gram-positive bacilli were the most commonly isolated bacteria. The difference between the Asia Teb and Soredex barrier envelopes for the protection of microbiological contamination was not significant (p>0.05). Conclusion: The use of different types of protective barrier envelopes was not sufficient for prevention of microbiological contamination of PSP plates, and some adjunct modalities were required to decrease microbiological contamination of PSP plates.

Identification of HLA-I restricted epitopes in six vaccine candidates of Leishmania tropica using immunoinformatics and molecular dynamics simulation approaches.

In spite of numerous studies on vaccination for various species of Leishmania, research on the development of an effective vaccine for L. tropica is very scarce. In silico epitope prediction is a new way to survey the best vaccine candidates. Here, we predicted the best epitopes of six L. tropica antigens with vaccine capability against this pathogen, using highly frequent HLA-I alleles. Based on the frequent HLA alleles, the protein sequences were screened individually using four different MHC prediction applications, namely SYFPEITHI, ProPredI, BIMAS, and IEDB. Several in silico assays including clustering, human similarity exclusion, epitope conservancy prediction, investigating in experimental records, immunogenicity prediction, and prediction of population coverage were performed to narrow the results and to find the best epitopes. The selected epitopes and their restricted HLA-I alleles were docked and the final epitopes with the lowest binding energy (the highest binding affinity) were chosen. Finally, the stability and the binding properties of the best epitope-HLA-I combinations were analyzed using molecular dynamics simulation studies. We found ten potential peptides with strong binding affinity to highly frequent HLA-I alleles that can be further evaluated as vaccine targets against L. tropica.

Heterogeneity of humoral immune response to Leishmania tropica in an experimental model.

Humoral (antibody) response is an important part of immunity against pathogens. Despite the clear role of cell-mediated immune response in protection against leishmaniasis, the role of humoral responses is challenging. There is very limited data regarding humoral immune response against Leishmania tropica which is the causative agent of human cutaneous leishmaniasis in many parts of the world. Here, we have compared pathogenicity and antibody response against six Iranian Leishmania tropica isolates in BALB/c mice. A Leishmania major isolate was used for comparison. The parasites were injected into the mice followed by the evaluation of the lesion development, parasite load, and antibody responses (IgG1 and IgG2a). Our findings showed that some isolates caused the large lesions and high parasite load in the spleen and lymph node, while other isolates led to no lesion, no splenic parasitism, and low parasite load in the lymph node. The more pathogenic isolates induced higher antibody responses (IgG1 and IgG2a). Our results indicated that there is substantial heterogeneity among various Leishmania tropica isolates regarding the humoral immune response as well as the pathogenicity.